tor: Bump package version to 6 and fix backup.

[people/teissler/ipfire-2.x.git] / src / patches / linux-3.10.25-imq.patch

diff -ruN linux-3.10.27/drivers/net/imq.c linux-3.10.27-imq/drivers/net/imq.c
--- linux-3.10.27/drivers/net/imq.c     1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/drivers/net/imq.c 2014-01-18 10:19:59.342342913 +0100
@@ -0,0 +1,1001 @@
+/*
+ *             Pseudo-driver for the intermediate queue device.
+ *
+ *             This program is free software; you can redistribute it and/or
+ *             modify it under the terms of the GNU General Public License
+ *             as published by the Free Software Foundation; either version
+ *             2 of the License, or (at your option) any later version.
+ *
+ * Authors:    Patrick McHardy, <kaber@trash.net>
+ *
+ *            The first version was written by Martin Devera, <devik@cdi.cz>
+ *
+ * Credits:    Jan Rafaj <imq2t@cedric.vabo.cz>
+ *              - Update patch to 2.4.21
+ *             Sebastian Strollo <sstrollo@nortelnetworks.com>
+ *              - Fix "Dead-loop on netdevice imq"-issue
+ *             Marcel Sebek <sebek64@post.cz>
+ *              - Update to 2.6.2-rc1
+ *
+ *            After some time of inactivity there is a group taking care
+ *            of IMQ again: http://www.linuximq.net
+ *
+ *
+ *            2004/06/30 - New version of IMQ patch to kernels <=2.6.7
+ *             including the following changes:
+ *
+ *            - Correction of ipv6 support "+"s issue (Hasso Tepper)
+ *            - Correction of imq_init_devs() issue that resulted in
+ *            kernel OOPS unloading IMQ as module (Norbert Buchmuller)
+ *            - Addition of functionality to choose number of IMQ devices
+ *            during kernel config (Andre Correa)
+ *            - Addition of functionality to choose how IMQ hooks on
+ *            PRE and POSTROUTING (after or before NAT) (Andre Correa)
+ *            - Cosmetic corrections (Norbert Buchmuller) (Andre Correa)
+ *
+ *
+ *             2005/12/16 - IMQ versions between 2.6.7 and 2.6.13 were
+ *             released with almost no problems. 2.6.14-x was released
+ *             with some important changes: nfcache was removed; After
+ *             some weeks of trouble we figured out that some IMQ fields
+ *             in skb were missing in skbuff.c - skb_clone and copy_skb_header.
+ *             These functions are correctly patched by this new patch version.
+ *
+ *             Thanks for all who helped to figure out all the problems with
+ *             2.6.14.x: Patrick McHardy, Rune Kock, VeNoMouS, Max CtRiX,
+ *             Kevin Shanahan, Richard Lucassen, Valery Dachev (hopefully
+ *             I didn't forget anybody). I apologize again for my lack of time.
+ *
+ *
+ *             2008/06/17 - 2.6.25 - Changed imq.c to use qdisc_run() instead
+ *             of qdisc_restart() and moved qdisc_run() to tasklet to avoid
+ *             recursive locking. New initialization routines to fix 'rmmod' not
+ *             working anymore. Used code from ifb.c. (Jussi Kivilinna)
+ *
+ *             2008/08/06 - 2.6.26 - (JK)
+ *              - Replaced tasklet with 'netif_schedule()'.
+ *              - Cleaned up and added comments for imq_nf_queue().
+ *
+ *             2009/04/12
+ *              - Add skb_save_cb/skb_restore_cb helper functions for backuping
+ *                control buffer. This is needed because qdisc-layer on kernels
+ *                2.6.27 and newer overwrite control buffer. (Jussi Kivilinna)
+ *              - Add better locking for IMQ device. Hopefully this will solve
+ *                SMP issues. (Jussi Kivilinna)
+ *              - Port to 2.6.27
+ *              - Port to 2.6.28
+ *              - Port to 2.6.29 + fix rmmod not working
+ *
+ *             2009/04/20 - (Jussi Kivilinna)
+ *              - Use netdevice feature flags to avoid extra packet handling
+ *                by core networking layer and possibly increase performance.
+ *
+ *             2009/09/26 - (Jussi Kivilinna)
+ *              - Add imq_nf_reinject_lockless to fix deadlock with
+ *                imq_nf_queue/imq_nf_reinject.
+ *
+ *             2009/12/08 - (Jussi Kivilinna)
+ *              - Port to 2.6.32
+ *              - Add check for skb->nf_queue_entry==NULL in imq_dev_xmit()
+ *              - Also add better error checking for skb->nf_queue_entry usage
+ *
+ *             2010/02/25 - (Jussi Kivilinna)
+ *              - Port to 2.6.33
+ *
+ *             2010/08/15 - (Jussi Kivilinna)
+ *              - Port to 2.6.35
+ *              - Simplify hook registration by using nf_register_hooks.
+ *              - nf_reinject doesn't need spinlock around it, therefore remove
+ *                imq_nf_reinject function. Other nf_reinject users protect
+ *                their own data with spinlock. With IMQ however all data is
+ *                needed is stored per skbuff, so no locking is needed.
+ *              - Changed IMQ to use 'separate' NF_IMQ_QUEUE instead of
+ *                NF_QUEUE, this allows working coexistance of IMQ and other
+ *                NF_QUEUE users.
+ *              - Make IMQ multi-queue. Number of IMQ device queues can be
+ *                increased with 'numqueues' module parameters. Default number
+ *                of queues is 1, in other words by default IMQ works as
+ *                single-queue device. Multi-queue selection is based on
+ *                IFB multi-queue patch by Changli Gao <xiaosuo@gmail.com>.
+ *
+ *             2011/03/18 - (Jussi Kivilinna)
+ *              - Port to 2.6.38
+ *
+ *             2011/07/12 - (syoder89@gmail.com)
+ *              - Crash fix that happens when the receiving interface has more
+ *                than one queue (add missing skb_set_queue_mapping in
+ *                imq_select_queue).
+ *
+ *             2011/07/26 - (Jussi Kivilinna)
+ *              - Add queue mapping checks for packets exiting IMQ.
+ *              - Port to 3.0
+ *
+ *             2011/08/16 - (Jussi Kivilinna)
+ *              - Clear IFF_TX_SKB_SHARING flag that was added for linux 3.0.2
+ *
+ *             2011/11/03 - Germano Michel <germanomichel@gmail.com>
+ *              - Fix IMQ for net namespaces
+ *
+ *             2011/11/04 - Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *              - Port to 3.1
+ *              - Clean-up, move 'get imq device pointer by imqX name' to
+ *                separate function from imq_nf_queue().
+ *
+ *             2012/01/05 - Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *              - Port to 3.2
+ *
+ *             2012/03/19 - Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *              - Port to 3.3
+ *
+ *             2012/12/12 - Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *              - Port to 3.7
+ *              - Fix checkpatch.pl warnings
+ *
+ *             2013/09/10 - Jussi Kivilinna <jussi.kivilinna@iki.fi>
+ *              - Fixed GSO handling for 3.10, see imq_nf_queue() for comments.
+ *              - Don't copy skb->cb_next when copying or cloning skbuffs.
+ *
+ *            Also, many thanks to pablo Sebastian Greco for making the initial
+ *            patch and to those who helped the testing.
+ *
+ *             More info at: http://www.linuximq.net/ (Andre Correa)
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+#include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_arp.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       #include <linux/netfilter_ipv6.h>
+#endif
+#include <linux/imq.h>
+#include <net/pkt_sched.h>
+#include <net/netfilter/nf_queue.h>
+#include <net/sock.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_vlan.h>
+#include <linux/if_pppox.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+static int imq_nf_queue(struct nf_queue_entry *entry, unsigned queue_num);
+
+static nf_hookfn imq_nf_hook;
+
+static struct nf_hook_ops imq_ops[] = {
+       {
+       /* imq_ingress_ipv4 */
+               .hook           = imq_nf_hook,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_INET_PRE_ROUTING,
+#if defined(CONFIG_IMQ_BEHAVIOR_BA) || defined(CONFIG_IMQ_BEHAVIOR_BB)
+               .priority       = NF_IP_PRI_MANGLE + 1,
+#else
+               .priority       = NF_IP_PRI_NAT_DST + 1,
+#endif
+       },
+       {
+       /* imq_egress_ipv4 */
+               .hook           = imq_nf_hook,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_INET_POST_ROUTING,
+#if defined(CONFIG_IMQ_BEHAVIOR_AA) || defined(CONFIG_IMQ_BEHAVIOR_BA)
+               .priority       = NF_IP_PRI_LAST,
+#else
+               .priority       = NF_IP_PRI_NAT_SRC - 1,
+#endif
+       },
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       {
+       /* imq_ingress_ipv6 */
+               .hook           = imq_nf_hook,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET6,
+               .hooknum        = NF_INET_PRE_ROUTING,
+#if defined(CONFIG_IMQ_BEHAVIOR_BA) || defined(CONFIG_IMQ_BEHAVIOR_BB)
+               .priority       = NF_IP6_PRI_MANGLE + 1,
+#else
+               .priority       = NF_IP6_PRI_NAT_DST + 1,
+#endif
+       },
+       {
+       /* imq_egress_ipv6 */
+               .hook           = imq_nf_hook,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET6,
+               .hooknum        = NF_INET_POST_ROUTING,
+#if defined(CONFIG_IMQ_BEHAVIOR_AA) || defined(CONFIG_IMQ_BEHAVIOR_BA)
+               .priority       = NF_IP6_PRI_LAST,
+#else
+               .priority       = NF_IP6_PRI_NAT_SRC - 1,
+#endif
+       },
+#endif
+};
+
+#if defined(CONFIG_IMQ_NUM_DEVS)
+static int numdevs = CONFIG_IMQ_NUM_DEVS;
+#else
+static int numdevs = IMQ_MAX_DEVS;
+#endif
+
+static struct net_device *imq_devs_cache[IMQ_MAX_DEVS];
+
+#define IMQ_MAX_QUEUES 32
+static int numqueues = 1;
+static u32 imq_hashrnd;
+
+static inline __be16 pppoe_proto(const struct sk_buff *skb)
+{
+       return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
+                       sizeof(struct pppoe_hdr)));
+}
+
+static u16 imq_hash(struct net_device *dev, struct sk_buff *skb)
+{
+       unsigned int pull_len;
+       u16 protocol = skb->protocol;
+       u32 addr1, addr2;
+       u32 hash, ihl = 0;
+       union {
+               u16 in16[2];
+               u32 in32;
+       } ports;
+       u8 ip_proto;
+
+       pull_len = 0;
+
+recheck:
+       switch (protocol) {
+       case htons(ETH_P_8021Q): {
+               if (unlikely(skb_pull(skb, VLAN_HLEN) == NULL))
+                       goto other;
+
+               pull_len += VLAN_HLEN;
+               skb->network_header += VLAN_HLEN;
+
+               protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+               goto recheck;
+       }
+
+       case htons(ETH_P_PPP_SES): {
+               if (unlikely(skb_pull(skb, PPPOE_SES_HLEN) == NULL))
+                       goto other;
+
+               pull_len += PPPOE_SES_HLEN;
+               skb->network_header += PPPOE_SES_HLEN;
+
+               protocol = pppoe_proto(skb);
+               goto recheck;
+       }
+
+       case htons(ETH_P_IP): {
+               const struct iphdr *iph = ip_hdr(skb);
+
+               if (unlikely(!pskb_may_pull(skb, sizeof(struct iphdr))))
+                       goto other;
+
+               addr1 = iph->daddr;
+               addr2 = iph->saddr;
+
+               ip_proto = !(ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) ?
+                                iph->protocol : 0;
+               ihl = ip_hdrlen(skb);
+
+               break;
+       }
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       case htons(ETH_P_IPV6): {
+               const struct ipv6hdr *iph = ipv6_hdr(skb);
+               __be16 fo = 0;
+
+               if (unlikely(!pskb_may_pull(skb, sizeof(struct ipv6hdr))))
+                       goto other;
+
+               addr1 = iph->daddr.s6_addr32[3];
+               addr2 = iph->saddr.s6_addr32[3];
+               ihl = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &ip_proto,
+                                      &fo);
+               if (unlikely(ihl < 0))
+                       goto other;
+
+               break;
+       }
+#endif
+       default:
+other:
+               if (pull_len != 0) {
+                       skb_push(skb, pull_len);
+                       skb->network_header -= pull_len;
+               }
+
+               return (u16)(ntohs(protocol) % dev->real_num_tx_queues);
+       }
+
+       if (addr1 > addr2)
+               swap(addr1, addr2);
+
+       switch (ip_proto) {
+       case IPPROTO_TCP:
+       case IPPROTO_UDP:
+       case IPPROTO_DCCP:
+       case IPPROTO_ESP:
+       case IPPROTO_AH:
+       case IPPROTO_SCTP:
+       case IPPROTO_UDPLITE: {
+               if (likely(skb_copy_bits(skb, ihl, &ports.in32, 4) >= 0)) {
+                       if (ports.in16[0] > ports.in16[1])
+                               swap(ports.in16[0], ports.in16[1]);
+                       break;
+               }
+               /* fall-through */
+       }
+       default:
+               ports.in32 = 0;
+               break;
+       }
+
+       if (pull_len != 0) {
+               skb_push(skb, pull_len);
+               skb->network_header -= pull_len;
+       }
+
+       hash = jhash_3words(addr1, addr2, ports.in32, imq_hashrnd ^ ip_proto);
+
+       return (u16)(((u64)hash * dev->real_num_tx_queues) >> 32);
+}
+
+static inline bool sk_tx_queue_recorded(struct sock *sk)
+{
+       return (sk_tx_queue_get(sk) >= 0);
+}
+
+static struct netdev_queue *imq_select_queue(struct net_device *dev,
+                                               struct sk_buff *skb)
+{
+       u16 queue_index = 0;
+       u32 hash;
+
+       if (likely(dev->real_num_tx_queues == 1))
+               goto out;
+
+       /* IMQ can be receiving ingress or engress packets. */
+
+       /* Check first for if rx_queue is set */
+       if (skb_rx_queue_recorded(skb)) {
+               queue_index = skb_get_rx_queue(skb);
+               goto out;
+       }
+
+       /* Check if socket has tx_queue set */
+       if (sk_tx_queue_recorded(skb->sk)) {
+               queue_index = sk_tx_queue_get(skb->sk);
+               goto out;
+       }
+
+       /* Try use socket hash */
+       if (skb->sk && skb->sk->sk_hash) {
+               hash = skb->sk->sk_hash;
+               queue_index =
+                       (u16)(((u64)hash * dev->real_num_tx_queues) >> 32);
+               goto out;
+       }
+
+       /* Generate hash from packet data */
+       queue_index = imq_hash(dev, skb);
+
+out:
+       if (unlikely(queue_index >= dev->real_num_tx_queues))
+               queue_index = (u16)((u32)queue_index % dev->real_num_tx_queues);
+
+       skb_set_queue_mapping(skb, queue_index);
+       return netdev_get_tx_queue(dev, queue_index);
+}
+
+static struct net_device_stats *imq_get_stats(struct net_device *dev)
+{
+       return &dev->stats;
+}
+
+/* called for packets kfree'd in qdiscs at places other than enqueue */
+static void imq_skb_destructor(struct sk_buff *skb)
+{
+       struct nf_queue_entry *entry = skb->nf_queue_entry;
+
+       skb->nf_queue_entry = NULL;
+
+       if (entry) {
+               nf_queue_entry_release_refs(entry);
+               kfree(entry);
+       }
+
+       skb_restore_cb(skb); /* kfree backup */
+}
+
+static void imq_done_check_queue_mapping(struct sk_buff *skb,
+                                        struct net_device *dev)
+{
+       unsigned int queue_index;
+
+       /* Don't let queue_mapping be left too large after exiting IMQ */
+       if (likely(skb->dev != dev && skb->dev != NULL)) {
+               queue_index = skb_get_queue_mapping(skb);
+               if (unlikely(queue_index >= skb->dev->real_num_tx_queues)) {
+                       queue_index = (u16)((u32)queue_index %
+                                               skb->dev->real_num_tx_queues);
+                       skb_set_queue_mapping(skb, queue_index);
+               }
+       } else {
+               /* skb->dev was IMQ device itself or NULL, be on safe side and
+                * just clear queue mapping.
+                */
+               skb_set_queue_mapping(skb, 0);
+       }
+}
+
+static netdev_tx_t imq_dev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct nf_queue_entry *entry = skb->nf_queue_entry;
+
+       skb->nf_queue_entry = NULL;
+       dev->trans_start = jiffies;
+
+       dev->stats.tx_bytes += skb->len;
+       dev->stats.tx_packets++;
+
+       if (unlikely(entry == NULL)) {
+               /* We don't know what is going on here.. packet is queued for
+                * imq device, but (probably) not by us.
+                *
+                * If this packet was not send here by imq_nf_queue(), then
+                * skb_save_cb() was not used and skb_free() should not show:
+                *   WARNING: IMQ: kfree_skb: skb->cb_next:..
+                * and/or
+                *   WARNING: IMQ: kfree_skb: skb->nf_queue_entry...
+                *
+                * However if this message is shown, then IMQ is somehow broken
+                * and you should report this to linuximq.net.
+                */
+
+               /* imq_dev_xmit is black hole that eats all packets, report that
+                * we eat this packet happily and increase dropped counters.
+                */
+
+               dev->stats.tx_dropped++;
+               dev_kfree_skb(skb);
+
+               return NETDEV_TX_OK;
+       }
+
+       skb_restore_cb(skb); /* restore skb->cb */
+
+       skb->imq_flags = 0;
+       skb->destructor = NULL;
+
+       imq_done_check_queue_mapping(skb, dev);
+
+       nf_reinject(entry, NF_ACCEPT);
+
+       return NETDEV_TX_OK;
+}
+
+static struct net_device *get_imq_device_by_index(int index)
+{
+       struct net_device *dev = NULL;
+       struct net *net;
+       char buf[8];
+
+       /* get device by name and cache result */
+       snprintf(buf, sizeof(buf), "imq%d", index);
+
+       /* Search device from all namespaces. */
+       for_each_net(net) {
+               dev = dev_get_by_name(net, buf);
+               if (dev)
+                       break;
+       }
+
+       if (WARN_ON_ONCE(dev == NULL)) {
+               /* IMQ device not found. Exotic config? */
+               return ERR_PTR(-ENODEV);
+       }
+
+       imq_devs_cache[index] = dev;
+       dev_put(dev);
+
+       return dev;
+}
+
+static struct nf_queue_entry *nf_queue_entry_dup(struct nf_queue_entry *e)
+{
+       struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
+       if (entry) {
+               if (nf_queue_entry_get_refs(entry))
+                       return entry;
+               kfree(entry);
+       }
+       return NULL;
+}
+
+#ifdef CONFIG_BRIDGE_NETFILTER
+/* When called from bridge netfilter, skb->data must point to MAC header
+ * before calling skb_gso_segment(). Else, original MAC header is lost
+ * and segmented skbs will be sent to wrong destination.
+ */
+static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
+{
+       if (skb->nf_bridge)
+               __skb_push(skb, skb->network_header - skb->mac_header);
+}
+
+static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
+{
+       if (skb->nf_bridge)
+               __skb_pull(skb, skb->network_header - skb->mac_header);
+}
+#else
+#define nf_bridge_adjust_skb_data(s) do {} while (0)
+#define nf_bridge_adjust_segmented_data(s) do {} while (0)
+#endif
+
+static void free_entry(struct nf_queue_entry *entry)
+{
+       nf_queue_entry_release_refs(entry);
+       kfree(entry);
+}
+
+static int __imq_nf_queue(struct nf_queue_entry *entry, struct net_device *dev);
+
+static int __imq_nf_queue_gso(struct nf_queue_entry *entry,
+                             struct net_device *dev, struct sk_buff *skb)
+{
+       int ret = -ENOMEM;
+       struct nf_queue_entry *entry_seg;
+
+       nf_bridge_adjust_segmented_data(skb);
+
+       if (skb->next == NULL) { /* last packet, no need to copy entry */
+               struct sk_buff *gso_skb = entry->skb;
+               entry->skb = skb;
+               ret = __imq_nf_queue(entry, dev);
+               if (ret)
+                       entry->skb = gso_skb;
+               return ret;
+       }
+
+       skb->next = NULL;
+
+       entry_seg = nf_queue_entry_dup(entry);
+       if (entry_seg) {
+               entry_seg->skb = skb;
+               ret = __imq_nf_queue(entry_seg, dev);
+               if (ret)
+                       free_entry(entry_seg);
+       }
+       return ret;
+}
+
+static int imq_nf_queue(struct nf_queue_entry *entry, unsigned queue_num)
+{
+       struct sk_buff *skb, *segs;
+       struct net_device *dev;
+       unsigned int queued;
+       int index, retval, err;
+
+       index = entry->skb->imq_flags & IMQ_F_IFMASK;
+       if (unlikely(index > numdevs - 1)) {
+               if (net_ratelimit())
+                       pr_warn("IMQ: invalid device specified, highest is %u\n",
+                               numdevs - 1);
+               retval = -EINVAL;
+               goto out_no_dev;
+       }
+
+       /* check for imq device by index from cache */
+       dev = imq_devs_cache[index];
+       if (unlikely(!dev)) {
+               dev = get_imq_device_by_index(index);
+               if (IS_ERR(dev)) {
+                       retval = PTR_ERR(dev);
+                       goto out_no_dev;
+               }
+       }
+
+       if (unlikely(!(dev->flags & IFF_UP))) {
+               entry->skb->imq_flags = 0;
+               retval = -ECANCELED;
+               goto out_no_dev;
+       }
+
+       if (!skb_is_gso(entry->skb))
+               return __imq_nf_queue(entry, dev);
+
+       /* Since 3.10.x, GSO handling moved here as result of upstream commit
+        * a5fedd43d5f6c94c71053a66e4c3d2e35f1731a2 (netfilter: move
+        * skb_gso_segment into nfnetlink_queue module).
+        *
+        * Following code replicates the gso handling from
+        * 'net/netfilter/nfnetlink_queue_core.c':nfqnl_enqueue_packet().
+        */
+
+       skb = entry->skb;
+
+       switch (entry->pf) {
+       case NFPROTO_IPV4:
+               skb->protocol = htons(ETH_P_IP);
+               break;
+       case NFPROTO_IPV6:
+               skb->protocol = htons(ETH_P_IPV6);
+               break;
+       }
+
+       nf_bridge_adjust_skb_data(skb);
+       segs = skb_gso_segment(skb, 0);
+       /* Does not use PTR_ERR to limit the number of error codes that can be
+        * returned by nf_queue.  For instance, callers rely on -ECANCELED to
+        * mean 'ignore this hook'.
+        */
+       err = -ENOBUFS;
+       if (IS_ERR(segs))
+               goto out_err;
+       queued = 0;
+       err = 0;
+       do {
+               struct sk_buff *nskb = segs->next;
+               if (nskb && nskb->next)
+                       nskb->cb_next = NULL;
+               if (err == 0)
+                       err = __imq_nf_queue_gso(entry, dev, segs);
+               if (err == 0)
+                       queued++;
+               else
+                       kfree_skb(segs);
+               segs = nskb;
+       } while (segs);
+
+       if (queued) {
+               if (err) /* some segments are already queued */
+                       free_entry(entry);
+               kfree_skb(skb);
+               return 0;
+       }
+
+out_err:
+       nf_bridge_adjust_segmented_data(skb);
+       retval = err;
+out_no_dev:
+       return retval;
+}
+
+static int __imq_nf_queue(struct nf_queue_entry *entry, struct net_device *dev)
+{
+       struct sk_buff *skb_orig, *skb, *skb_shared;
+       struct Qdisc *q;
+       struct netdev_queue *txq;
+       spinlock_t *root_lock;
+       int users;
+       int retval = -EINVAL;
+       unsigned int orig_queue_index;
+
+       dev->last_rx = jiffies;
+
+       skb = entry->skb;
+       skb_orig = NULL;
+
+       /* skb has owner? => make clone */
+       if (unlikely(skb->destructor)) {
+               skb_orig = skb;
+               skb = skb_clone(skb, GFP_ATOMIC);
+               if (unlikely(!skb)) {
+                       retval = -ENOMEM;
+                       goto out;
+               }
+               skb->cb_next = NULL;
+               entry->skb = skb;
+       }
+
+       skb->nf_queue_entry = entry;
+
+       dev->stats.rx_bytes += skb->len;
+       dev->stats.rx_packets++;
+
+       if (!skb->dev) {
+               /* skb->dev == NULL causes problems, try the find cause. */
+               if (net_ratelimit()) {
+                       dev_warn(&dev->dev,
+                                "received packet with skb->dev == NULL\n");
+                       dump_stack();
+               }
+
+               skb->dev = dev;
+       }
+
+       /* Disables softirqs for lock below */
+       rcu_read_lock_bh();
+
+       /* Multi-queue selection */
+       orig_queue_index = skb_get_queue_mapping(skb);
+       txq = imq_select_queue(dev, skb);
+
+       q = rcu_dereference(txq->qdisc);
+       if (unlikely(!q->enqueue))
+               goto packet_not_eaten_by_imq_dev;
+
+       root_lock = qdisc_lock(q);
+       spin_lock(root_lock);
+
+       users = atomic_read(&skb->users);
+
+       skb_shared = skb_get(skb); /* increase reference count by one */
+
+       /* backup skb->cb, as qdisc layer will overwrite it */
+       skb_save_cb(skb_shared);
+       qdisc_enqueue_root(skb_shared, q); /* might kfree_skb */
+
+       if (likely(atomic_read(&skb_shared->users) == users + 1)) {
+               kfree_skb(skb_shared); /* decrease reference count by one */
+
+               skb->destructor = &imq_skb_destructor;
+
+               /* cloned? */
+               if (unlikely(skb_orig))
+                       kfree_skb(skb_orig); /* free original */
+
+               spin_unlock(root_lock);
+               rcu_read_unlock_bh();
+
+               /* schedule qdisc dequeue */
+               __netif_schedule(q);
+
+               retval = 0;
+               goto out;
+       } else {
+               skb_restore_cb(skb_shared); /* restore skb->cb */
+               skb->nf_queue_entry = NULL;
+               /*
+                * qdisc dropped packet and decreased skb reference count of
+                * skb, so we don't really want to and try refree as that would
+                * actually destroy the skb.
+                */
+               spin_unlock(root_lock);
+               goto packet_not_eaten_by_imq_dev;
+       }
+
+packet_not_eaten_by_imq_dev:
+       skb_set_queue_mapping(skb, orig_queue_index);
+       rcu_read_unlock_bh();
+
+       /* cloned? restore original */
+       if (unlikely(skb_orig)) {
+               kfree_skb(skb);
+               entry->skb = skb_orig;
+       }
+       retval = -1;
+out:
+       return retval;
+}
+
+static unsigned int imq_nf_hook(unsigned int hook, struct sk_buff *pskb,
+                               const struct net_device *indev,
+                               const struct net_device *outdev,
+                               int (*okfn)(struct sk_buff *))
+{
+       return (pskb->imq_flags & IMQ_F_ENQUEUE) ? NF_IMQ_QUEUE : NF_ACCEPT;
+}
+
+static int imq_close(struct net_device *dev)
+{
+       netif_stop_queue(dev);
+       return 0;
+}
+
+static int imq_open(struct net_device *dev)
+{
+       netif_start_queue(dev);
+       return 0;
+}
+
+static const struct net_device_ops imq_netdev_ops = {
+       .ndo_open               = imq_open,
+       .ndo_stop               = imq_close,
+       .ndo_start_xmit         = imq_dev_xmit,
+       .ndo_get_stats          = imq_get_stats,
+};
+
+static void imq_setup(struct net_device *dev)
+{
+       dev->netdev_ops         = &imq_netdev_ops;
+       dev->type               = ARPHRD_VOID;
+       dev->mtu                = 16000; /* too small? */
+       dev->tx_queue_len       = 11000; /* too big? */
+       dev->flags              = IFF_NOARP;
+       dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST |
+                                 NETIF_F_GSO | NETIF_F_HW_CSUM |
+                                 NETIF_F_HIGHDMA;
+       dev->priv_flags         &= ~(IFF_XMIT_DST_RELEASE |
+                                    IFF_TX_SKB_SHARING);
+}
+
+static int imq_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+       int ret = 0;
+
+       if (tb[IFLA_ADDRESS]) {
+               if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
+                       ret = -EINVAL;
+                       goto end;
+               }
+               if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
+                       ret = -EADDRNOTAVAIL;
+                       goto end;
+               }
+       }
+       return 0;
+end:
+       pr_warn("IMQ: imq_validate failed (%d)\n", ret);
+       return ret;
+}
+
+static struct rtnl_link_ops imq_link_ops __read_mostly = {
+       .kind           = "imq",
+       .priv_size      = 0,
+       .setup          = imq_setup,
+       .validate       = imq_validate,
+};
+
+static const struct nf_queue_handler imq_nfqh = {
+       .outfn = imq_nf_queue,
+};
+
+static int __init imq_init_hooks(void)
+{
+       int ret;
+
+       nf_register_queue_imq_handler(&imq_nfqh);
+
+       ret = nf_register_hooks(imq_ops, ARRAY_SIZE(imq_ops));
+       if (ret < 0)
+               nf_unregister_queue_imq_handler();
+
+       return ret;
+}
+
+static int __init imq_init_one(int index)
+{
+       struct net_device *dev;
+       int ret;
+
+       dev = alloc_netdev_mq(0, "imq%d", imq_setup, numqueues);
+       if (!dev)
+               return -ENOMEM;
+
+       ret = dev_alloc_name(dev, dev->name);
+       if (ret < 0)
+               goto fail;
+
+       dev->rtnl_link_ops = &imq_link_ops;
+       ret = register_netdevice(dev);
+       if (ret < 0)
+               goto fail;
+
+       return 0;
+fail:
+       free_netdev(dev);
+       return ret;
+}
+
+static int __init imq_init_devs(void)
+{
+       int err, i;
+
+       if (numdevs < 1 || numdevs > IMQ_MAX_DEVS) {
+               pr_err("IMQ: numdevs has to be betweed 1 and %u\n",
+                      IMQ_MAX_DEVS);
+               return -EINVAL;
+       }
+
+       if (numqueues < 1 || numqueues > IMQ_MAX_QUEUES) {
+               pr_err("IMQ: numqueues has to be betweed 1 and %u\n",
+                      IMQ_MAX_QUEUES);
+               return -EINVAL;
+       }
+
+       get_random_bytes(&imq_hashrnd, sizeof(imq_hashrnd));
+
+       rtnl_lock();
+       err = __rtnl_link_register(&imq_link_ops);
+
+       for (i = 0; i < numdevs && !err; i++)
+               err = imq_init_one(i);
+
+       if (err) {
+               __rtnl_link_unregister(&imq_link_ops);
+               memset(imq_devs_cache, 0, sizeof(imq_devs_cache));
+       }
+       rtnl_unlock();
+
+       return err;
+}
+
+static int __init imq_init_module(void)
+{
+       int err;
+
+#if defined(CONFIG_IMQ_NUM_DEVS)
+       BUILD_BUG_ON(CONFIG_IMQ_NUM_DEVS > 16);
+       BUILD_BUG_ON(CONFIG_IMQ_NUM_DEVS < 2);
+       BUILD_BUG_ON(CONFIG_IMQ_NUM_DEVS - 1 > IMQ_F_IFMASK);
+#endif
+
+       err = imq_init_devs();
+       if (err) {
+               pr_err("IMQ: Error trying imq_init_devs(net)\n");
+               return err;
+       }
+
+       err = imq_init_hooks();
+       if (err) {
+               pr_err(KERN_ERR "IMQ: Error trying imq_init_hooks()\n");
+               rtnl_link_unregister(&imq_link_ops);
+               memset(imq_devs_cache, 0, sizeof(imq_devs_cache));
+               return err;
+       }
+
+       pr_info("IMQ driver loaded successfully. (numdevs = %d, numqueues = %d)\n",
+               numdevs, numqueues);
+
+#if defined(CONFIG_IMQ_BEHAVIOR_BA) || defined(CONFIG_IMQ_BEHAVIOR_BB)
+       pr_info("\tHooking IMQ before NAT on PREROUTING.\n");
+#else
+       pr_info("\tHooking IMQ after NAT on PREROUTING.\n");
+#endif
+#if defined(CONFIG_IMQ_BEHAVIOR_AB) || defined(CONFIG_IMQ_BEHAVIOR_BB)
+       pr_info("\tHooking IMQ before NAT on POSTROUTING.\n");
+#else
+       pr_info("\tHooking IMQ after NAT on POSTROUTING.\n");
+#endif
+
+       return 0;
+}
+
+static void __exit imq_unhook(void)
+{
+       nf_unregister_hooks(imq_ops, ARRAY_SIZE(imq_ops));
+       nf_unregister_queue_imq_handler();
+}
+
+static void __exit imq_cleanup_devs(void)
+{
+       rtnl_link_unregister(&imq_link_ops);
+       memset(imq_devs_cache, 0, sizeof(imq_devs_cache));
+}
+
+static void __exit imq_exit_module(void)
+{
+       imq_unhook();
+       imq_cleanup_devs();
+       pr_info("IMQ driver unloaded successfully.\n");
+}
+
+module_init(imq_init_module);
+module_exit(imq_exit_module);
+
+module_param(numdevs, int, 0);
+module_param(numqueues, int, 0);
+MODULE_PARM_DESC(numdevs, "number of IMQ devices (how many imq* devices will be created)");
+MODULE_PARM_DESC(numqueues, "number of queues per IMQ device");
+MODULE_AUTHOR("http://www.linuximq.net");
+MODULE_DESCRIPTION("Pseudo-driver for the intermediate queue device. See http://www.linuximq.net/ for more information.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("imq");
+
diff -ruN linux-3.10.27/drivers/net/Kconfig linux-3.10.27-imq/drivers/net/Kconfig
--- linux-3.10.27/drivers/net/Kconfig   2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/drivers/net/Kconfig       2014-01-18 10:19:59.341342885 +0100
@@ -207,6 +207,125 @@
        depends on RIONET
        default "128"
 
+config IMQ
+       tristate "IMQ (intermediate queueing device) support"
+       depends on NETDEVICES && NETFILTER
+       ---help---
+         The IMQ device(s) is used as placeholder for QoS queueing
+         disciplines. Every packet entering/leaving the IP stack can be
+         directed through the IMQ device where it's enqueued/dequeued to the
+         attached qdisc. This allows you to treat network devices as classes
+         and distribute bandwidth among them. Iptables is used to specify
+         through which IMQ device, if any, packets travel.
+
+         More information at: http://www.linuximq.net/
+
+         To compile this driver as a module, choose M here: the module
+         will be called imq.  If unsure, say N.
+
+choice
+       prompt "IMQ behavior (PRE/POSTROUTING)"
+       depends on IMQ
+       default IMQ_BEHAVIOR_AB
+       help
+         This setting defines how IMQ behaves in respect to its
+         hooking in PREROUTING and POSTROUTING.
+
+         IMQ can work in any of the following ways:
+
+             PREROUTING   |      POSTROUTING
+         -----------------|-------------------
+         #1  After NAT    |      After NAT
+         #2  After NAT    |      Before NAT
+         #3  Before NAT   |      After NAT
+         #4  Before NAT   |      Before NAT
+
+         The default behavior is to hook before NAT on PREROUTING
+         and after NAT on POSTROUTING (#3).
+
+         This settings are specially usefull when trying to use IMQ
+         to shape NATed clients.
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
+config IMQ_BEHAVIOR_AA
+       bool "IMQ AA"
+       help
+         This setting defines how IMQ behaves in respect to its
+         hooking in PREROUTING and POSTROUTING.
+
+         Choosing this option will make IMQ hook like this:
+
+         PREROUTING:   After NAT
+         POSTROUTING:  After NAT
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
+config IMQ_BEHAVIOR_AB
+       bool "IMQ AB"
+       help
+         This setting defines how IMQ behaves in respect to its
+         hooking in PREROUTING and POSTROUTING.
+
+         Choosing this option will make IMQ hook like this:
+
+         PREROUTING:   After NAT
+         POSTROUTING:  Before NAT
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
+config IMQ_BEHAVIOR_BA
+       bool "IMQ BA"
+       help
+         This setting defines how IMQ behaves in respect to its
+         hooking in PREROUTING and POSTROUTING.
+
+         Choosing this option will make IMQ hook like this:
+
+         PREROUTING:   Before NAT
+         POSTROUTING:  After NAT
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
+config IMQ_BEHAVIOR_BB
+       bool "IMQ BB"
+       help
+         This setting defines how IMQ behaves in respect to its
+         hooking in PREROUTING and POSTROUTING.
+
+         Choosing this option will make IMQ hook like this:
+
+         PREROUTING:   Before NAT
+         POSTROUTING:  Before NAT
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
+endchoice
+
+config IMQ_NUM_DEVS
+       int "Number of IMQ devices"
+       range 2 16
+       depends on IMQ
+       default "16"
+       help
+         This setting defines how many IMQ devices will be created.
+
+         The default value is 16.
+
+         More information can be found at: www.linuximq.net
+
+         If not sure leave the default settings alone.
+
 config TUN
        tristate "Universal TUN/TAP device driver support"
        select CRC32
diff -ruN linux-3.10.27/drivers/net/Makefile linux-3.10.27-imq/drivers/net/Makefile
--- linux-3.10.27/drivers/net/Makefile  2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/drivers/net/Makefile      2014-01-18 10:19:59.341342885 +0100
@@ -9,6 +9,7 @@
 obj-$(CONFIG_DUMMY) += dummy.o
 obj-$(CONFIG_EQUALIZER) += eql.o
 obj-$(CONFIG_IFB) += ifb.o
+obj-$(CONFIG_IMQ) += imq.o
 obj-$(CONFIG_MACVLAN) += macvlan.o
 obj-$(CONFIG_MACVTAP) += macvtap.o
 obj-$(CONFIG_MII) += mii.o
diff -ruN linux-3.10.27/include/linux/imq.h linux-3.10.27-imq/include/linux/imq.h
--- linux-3.10.27/include/linux/imq.h   1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/include/linux/imq.h       2014-01-18 10:19:59.342342913 +0100
@@ -0,0 +1,13 @@
+#ifndef _IMQ_H
+#define _IMQ_H
+
+/* IFMASK (16 device indexes, 0 to 15) and flag(s) fit in 5 bits */
+#define IMQ_F_BITS     5
+
+#define IMQ_F_IFMASK   0x0f
+#define IMQ_F_ENQUEUE  0x10
+
+#define IMQ_MAX_DEVS   (IMQ_F_IFMASK + 1)
+
+#endif /* _IMQ_H */
+
diff -ruN linux-3.10.27/include/linux/netfilter/xt_IMQ.h linux-3.10.27-imq/include/linux/netfilter/xt_IMQ.h
--- linux-3.10.27/include/linux/netfilter/xt_IMQ.h      1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/include/linux/netfilter/xt_IMQ.h  2014-01-18 10:19:59.342342913 +0100
@@ -0,0 +1,9 @@
+#ifndef _XT_IMQ_H
+#define _XT_IMQ_H
+
+struct xt_imq_info {
+       unsigned int todev;     /* target imq device */
+};
+
+#endif /* _XT_IMQ_H */
+
diff -ruN linux-3.10.27/include/linux/netfilter_ipv4/ipt_IMQ.h linux-3.10.27-imq/include/linux/netfilter_ipv4/ipt_IMQ.h
--- linux-3.10.27/include/linux/netfilter_ipv4/ipt_IMQ.h        1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/include/linux/netfilter_ipv4/ipt_IMQ.h    2014-01-18 10:19:59.343342933 +0100
@@ -0,0 +1,10 @@
+#ifndef _IPT_IMQ_H
+#define _IPT_IMQ_H
+
+/* Backwards compatibility for old userspace */
+#include <linux/netfilter/xt_IMQ.h>
+
+#define ipt_imq_info xt_imq_info
+
+#endif /* _IPT_IMQ_H */
+
diff -ruN linux-3.10.27/include/linux/netfilter_ipv6/ip6t_IMQ.h linux-3.10.27-imq/include/linux/netfilter_ipv6/ip6t_IMQ.h
--- linux-3.10.27/include/linux/netfilter_ipv6/ip6t_IMQ.h       1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/include/linux/netfilter_ipv6/ip6t_IMQ.h   2014-01-18 10:19:59.343342933 +0100
@@ -0,0 +1,10 @@
+#ifndef _IP6T_IMQ_H
+#define _IP6T_IMQ_H
+
+/* Backwards compatibility for old userspace */
+#include <linux/netfilter/xt_IMQ.h>
+
+#define ip6t_imq_info xt_imq_info
+
+#endif /* _IP6T_IMQ_H */
+
diff -ruN linux-3.10.27/include/linux/skbuff.h linux-3.10.27-imq/include/linux/skbuff.h
--- linux-3.10.27/include/linux/skbuff.h        2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/include/linux/skbuff.h    2014-01-18 10:18:22.220271201 +0100
@@ -33,6 +33,9 @@
 #include <linux/dma-mapping.h>
 #include <linux/netdev_features.h>
 #include <net/flow_keys.h>
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+#include <linux/imq.h>
+#endif
 
 /* Don't change this without changing skb_csum_unnecessary! */
 #define CHECKSUM_NONE 0
@@ -414,6 +417,9 @@
         * first. This is owned by whoever has the skb queued ATM.
         */
        char                    cb[48] __aligned(8);
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       void                    *cb_next;
+#endif
 
        unsigned long           _skb_refdst;
 #ifdef CONFIG_XFRM
@@ -449,6 +455,9 @@
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
        struct nf_conntrack     *nfct;
 #endif
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       struct nf_queue_entry   *nf_queue_entry;
+#endif
 #ifdef CONFIG_BRIDGE_NETFILTER
        struct nf_bridge_info   *nf_bridge;
 #endif
@@ -487,7 +496,9 @@
        __u8                    encapsulation:1;
        /* 7/9 bit hole (depending on ndisc_nodetype presence) */
        kmemcheck_bitfield_end(flags2);
-
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       __u8                    imq_flags:IMQ_F_BITS;
+#endif
 #ifdef CONFIG_NET_DMA
        dma_cookie_t            dma_cookie;
 #endif
@@ -616,7 +627,10 @@
 {
        return (struct rtable *)skb_dst(skb);
 }
-
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+extern int skb_save_cb(struct sk_buff *skb);
+extern int skb_restore_cb(struct sk_buff *skb);
+#endif
 extern void kfree_skb(struct sk_buff *skb);
 extern void kfree_skb_list(struct sk_buff *segs);
 extern void skb_tx_error(struct sk_buff *skb);
@@ -2735,6 +2749,10 @@
        nf_conntrack_get(src->nfct);
        dst->nfctinfo = src->nfctinfo;
 #endif
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       dst->imq_flags = src->imq_flags;
+       dst->nf_queue_entry = src->nf_queue_entry;
+#endif
 #ifdef CONFIG_BRIDGE_NETFILTER
        dst->nf_bridge  = src->nf_bridge;
        nf_bridge_get(src->nf_bridge);
diff -ruN linux-3.10.27/include/net/netfilter/nf_queue.h linux-3.10.27-imq/include/net/netfilter/nf_queue.h
--- linux-3.10.27/include/net/netfilter/nf_queue.h      2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/include/net/netfilter/nf_queue.h  2014-01-18 10:19:59.345342949 +0100
@@ -29,6 +29,12 @@
 void nf_register_queue_handler(const struct nf_queue_handler *qh);
 void nf_unregister_queue_handler(void);
 extern void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
+extern void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
+
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+extern void nf_register_queue_imq_handler(const struct nf_queue_handler *qh);
+extern void nf_unregister_queue_imq_handler(void);
+#endif
 
 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
diff -ruN linux-3.10.27/include/uapi/linux/netfilter.h linux-3.10.27-imq/include/uapi/linux/netfilter.h
--- linux-3.10.27/include/uapi/linux/netfilter.h        2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/include/uapi/linux/netfilter.h    2014-01-18 10:19:59.345342949 +0100
@@ -13,7 +13,8 @@
 #define NF_QUEUE 3
 #define NF_REPEAT 4
 #define NF_STOP 5
-#define NF_MAX_VERDICT NF_STOP
+#define NF_IMQ_QUEUE 6
+#define NF_MAX_VERDICT NF_IMQ_QUEUE
 
 /* we overload the higher bits for encoding auxiliary data such as the queue
  * number or errno values. Not nice, but better than additional function
diff -ruN linux-3.10.27/net/core/dev.c linux-3.10.27-imq/net/core/dev.c
--- linux-3.10.27/net/core/dev.c        2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/core/dev.c    2014-01-18 10:19:59.347342963 +0100
@@ -129,6 +129,9 @@
 #include <linux/inetdevice.h>
 #include <linux/cpu_rmap.h>
 #include <linux/static_key.h>
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+#include <linux/imq.h>
+#endif
 
 #include "net-sysfs.h"
 
@@ -2573,7 +2576,12 @@
                        }
                }
 
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+               if (!list_empty(&ptype_all) &&
+                                       !(skb->imq_flags & IMQ_F_ENQUEUE))
+#else
                if (!list_empty(&ptype_all))
+#endif
                        dev_queue_xmit_nit(skb, dev);
 
                skb_len = skb->len;
diff -ruN linux-3.10.27/net/core/skbuff.c linux-3.10.27-imq/net/core/skbuff.c
--- linux-3.10.27/net/core/skbuff.c     2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/core/skbuff.c 2014-01-18 10:19:59.348342972 +0100
@@ -73,6 +73,9 @@
 
 struct kmem_cache *skbuff_head_cache __read_mostly;
 static struct kmem_cache *skbuff_fclone_cache __read_mostly;
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+static struct kmem_cache *skbuff_cb_store_cache __read_mostly;
+#endif
 
 static void sock_pipe_buf_release(struct pipe_inode_info *pipe,
                                  struct pipe_buffer *buf)
@@ -92,6 +95,82 @@
        return 1;
 }
 
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+/* Control buffer save/restore for IMQ devices */
+struct skb_cb_table {
+       char                    cb[48] __aligned(8);
+       void                    *cb_next;
+       atomic_t                refcnt;
+};
+
+static DEFINE_SPINLOCK(skb_cb_store_lock);
+
+int skb_save_cb(struct sk_buff *skb)
+{
+       struct skb_cb_table *next;
+
+       next = kmem_cache_alloc(skbuff_cb_store_cache, GFP_ATOMIC);
+       if (!next)
+               return -ENOMEM;
+
+       BUILD_BUG_ON(sizeof(skb->cb) != sizeof(next->cb));
+
+       memcpy(next->cb, skb->cb, sizeof(skb->cb));
+       next->cb_next = skb->cb_next;
+
+       atomic_set(&next->refcnt, 1);
+
+       skb->cb_next = next;
+       return 0;
+}
+EXPORT_SYMBOL(skb_save_cb);
+
+int skb_restore_cb(struct sk_buff *skb)
+{
+       struct skb_cb_table *next;
+
+       if (!skb->cb_next)
+               return 0;
+
+       next = skb->cb_next;
+
+       BUILD_BUG_ON(sizeof(skb->cb) != sizeof(next->cb));
+
+       memcpy(skb->cb, next->cb, sizeof(skb->cb));
+       skb->cb_next = next->cb_next;
+
+       spin_lock(&skb_cb_store_lock);
+
+       if (atomic_dec_and_test(&next->refcnt))
+               kmem_cache_free(skbuff_cb_store_cache, next);
+
+       spin_unlock(&skb_cb_store_lock);
+
+       return 0;
+}
+EXPORT_SYMBOL(skb_restore_cb);
+
+static void skb_copy_stored_cb(struct sk_buff *new, const struct sk_buff *__old)
+{
+       struct skb_cb_table *next;
+       struct sk_buff *old;
+
+       if (!__old->cb_next) {
+               new->cb_next = NULL;
+               return;
+       }
+
+       spin_lock(&skb_cb_store_lock);
+
+       old = (struct sk_buff *)__old;
+
+       next = old->cb_next;
+       atomic_inc(&next->refcnt);
+       new->cb_next = next;
+
+       spin_unlock(&skb_cb_store_lock);
+}
+#endif
 
 /* Pipe buffer operations for a socket. */
 static const struct pipe_buf_operations sock_pipe_buf_ops = {
@@ -582,6 +661,28 @@
                WARN_ON(in_irq());
                skb->destructor(skb);
        }
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       /*
+        * This should not happen. When it does, avoid memleak by restoring
+        * the chain of cb-backups.
+        */
+       while (skb->cb_next != NULL) {
+               if (net_ratelimit())
+                       pr_warn("IMQ: kfree_skb: skb->cb_next: %08x\n",
+                               (unsigned int)skb->cb_next);
+
+               skb_restore_cb(skb);
+       }
+       /*
+        * This should not happen either, nf_queue_entry is nullified in
+        * imq_dev_xmit(). If we have non-NULL nf_queue_entry then we are
+        * leaking entry pointers, maybe memory. We don't know if this is
+        * pointer to already freed memory, or should this be freed.
+        * If this happens we need to add refcounting, etc for nf_queue_entry.
+        */
+       if (skb->nf_queue_entry && net_ratelimit())
+               pr_warn("%s\n", "IMQ: kfree_skb: skb->nf_queue_entry != NULL");
+#endif
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
        nf_conntrack_put(skb->nfct);
 #endif
@@ -713,6 +814,10 @@
        new->sp                 = secpath_get(old->sp);
 #endif
        memcpy(new->cb, old->cb, sizeof(old->cb));
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       new->cb_next = NULL;
+       /*skb_copy_stored_cb(new, old);*/
+#endif
        new->csum               = old->csum;
        new->local_df           = old->local_df;
        new->pkt_type           = old->pkt_type;
@@ -3093,6 +3198,13 @@
                                                0,
                                                SLAB_HWCACHE_ALIGN|SLAB_PANIC,
                                                NULL);
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+       skbuff_cb_store_cache = kmem_cache_create("skbuff_cb_store_cache",
+                                                 sizeof(struct skb_cb_table),
+                                                 0,
+                                                 SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+                                                 NULL);
+#endif
 }
 
 /**
diff -ruN linux-3.10.27/net/core/skbuff.c.orig linux-3.10.27-imq/net/core/skbuff.c.orig
--- linux-3.10.27/net/core/skbuff.c.orig        1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/net/core/skbuff.c.orig    2014-01-16 00:29:14.000000000 +0100
@@ -0,0 +1,3503 @@
+/*
+ *     Routines having to do with the 'struct sk_buff' memory handlers.
+ *
+ *     Authors:        Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *                     Florian La Roche <rzsfl@rz.uni-sb.de>
+ *
+ *     Fixes:
+ *             Alan Cox        :       Fixed the worst of the load
+ *                                     balancer bugs.
+ *             Dave Platt      :       Interrupt stacking fix.
+ *     Richard Kooijman        :       Timestamp fixes.
+ *             Alan Cox        :       Changed buffer format.
+ *             Alan Cox        :       destructor hook for AF_UNIX etc.
+ *             Linus Torvalds  :       Better skb_clone.
+ *             Alan Cox        :       Added skb_copy.
+ *             Alan Cox        :       Added all the changed routines Linus
+ *                                     only put in the headers
+ *             Ray VanTassle   :       Fixed --skb->lock in free
+ *             Alan Cox        :       skb_copy copy arp field
+ *             Andi Kleen      :       slabified it.
+ *             Robert Olsson   :       Removed skb_head_pool
+ *
+ *     NOTE:
+ *             The __skb_ routines should be called with interrupts
+ *     disabled, or you better be *real* sure that the operation is atomic
+ *     with respect to whatever list is being frobbed (e.g. via lock_sock()
+ *     or via disabling bottom half handlers, etc).
+ *
+ *     This program is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License
+ *     as published by the Free Software Foundation; either version
+ *     2 of the License, or (at your option) any later version.
+ */
+
+/*
+ *     The functions in this file will not compile correctly with gcc 2.4.x
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/kmemcheck.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#ifdef CONFIG_NET_CLS_ACT
+#include <net/pkt_sched.h>
+#endif
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/splice.h>
+#include <linux/cache.h>
+#include <linux/rtnetlink.h>
+#include <linux/init.h>
+#include <linux/scatterlist.h>
+#include <linux/errqueue.h>
+#include <linux/prefetch.h>
+
+#include <net/protocol.h>
+#include <net/dst.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+
+#include <asm/uaccess.h>
+#include <trace/events/skb.h>
+#include <linux/highmem.h>
+
+struct kmem_cache *skbuff_head_cache __read_mostly;
+static struct kmem_cache *skbuff_fclone_cache __read_mostly;
+
+static void sock_pipe_buf_release(struct pipe_inode_info *pipe,
+                                 struct pipe_buffer *buf)
+{
+       put_page(buf->page);
+}
+
+static void sock_pipe_buf_get(struct pipe_inode_info *pipe,
+                               struct pipe_buffer *buf)
+{
+       get_page(buf->page);
+}
+
+static int sock_pipe_buf_steal(struct pipe_inode_info *pipe,
+                              struct pipe_buffer *buf)
+{
+       return 1;
+}
+
+
+/* Pipe buffer operations for a socket. */
+static const struct pipe_buf_operations sock_pipe_buf_ops = {
+       .can_merge = 0,
+       .map = generic_pipe_buf_map,
+       .unmap = generic_pipe_buf_unmap,
+       .confirm = generic_pipe_buf_confirm,
+       .release = sock_pipe_buf_release,
+       .steal = sock_pipe_buf_steal,
+       .get = sock_pipe_buf_get,
+};
+
+/**
+ *     skb_panic - private function for out-of-line support
+ *     @skb:   buffer
+ *     @sz:    size
+ *     @addr:  address
+ *     @msg:   skb_over_panic or skb_under_panic
+ *
+ *     Out-of-line support for skb_put() and skb_push().
+ *     Called via the wrapper skb_over_panic() or skb_under_panic().
+ *     Keep out of line to prevent kernel bloat.
+ *     __builtin_return_address is not used because it is not always reliable.
+ */
+static void skb_panic(struct sk_buff *skb, unsigned int sz, void *addr,
+                     const char msg[])
+{
+       pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n",
+                msg, addr, skb->len, sz, skb->head, skb->data,
+                (unsigned long)skb->tail, (unsigned long)skb->end,
+                skb->dev ? skb->dev->name : "<NULL>");
+       BUG();
+}
+
+static void skb_over_panic(struct sk_buff *skb, unsigned int sz, void *addr)
+{
+       skb_panic(skb, sz, addr, __func__);
+}
+
+static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr)
+{
+       skb_panic(skb, sz, addr, __func__);
+}
+
+/*
+ * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells
+ * the caller if emergency pfmemalloc reserves are being used. If it is and
+ * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves
+ * may be used. Otherwise, the packet data may be discarded until enough
+ * memory is free
+ */
+#define kmalloc_reserve(size, gfp, node, pfmemalloc) \
+        __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc)
+
+static void *__kmalloc_reserve(size_t size, gfp_t flags, int node,
+                              unsigned long ip, bool *pfmemalloc)
+{
+       void *obj;
+       bool ret_pfmemalloc = false;
+
+       /*
+        * Try a regular allocation, when that fails and we're not entitled
+        * to the reserves, fail.
+        */
+       obj = kmalloc_node_track_caller(size,
+                                       flags | __GFP_NOMEMALLOC | __GFP_NOWARN,
+                                       node);
+       if (obj || !(gfp_pfmemalloc_allowed(flags)))
+               goto out;
+
+       /* Try again but now we are using pfmemalloc reserves */
+       ret_pfmemalloc = true;
+       obj = kmalloc_node_track_caller(size, flags, node);
+
+out:
+       if (pfmemalloc)
+               *pfmemalloc = ret_pfmemalloc;
+
+       return obj;
+}
+
+/*     Allocate a new skbuff. We do this ourselves so we can fill in a few
+ *     'private' fields and also do memory statistics to find all the
+ *     [BEEP] leaks.
+ *
+ */
+
+struct sk_buff *__alloc_skb_head(gfp_t gfp_mask, int node)
+{
+       struct sk_buff *skb;
+
+       /* Get the HEAD */
+       skb = kmem_cache_alloc_node(skbuff_head_cache,
+                                   gfp_mask & ~__GFP_DMA, node);
+       if (!skb)
+               goto out;
+
+       /*
+        * Only clear those fields we need to clear, not those that we will
+        * actually initialise below. Hence, don't put any more fields after
+        * the tail pointer in struct sk_buff!
+        */
+       memset(skb, 0, offsetof(struct sk_buff, tail));
+       skb->head = NULL;
+       skb->truesize = sizeof(struct sk_buff);
+       atomic_set(&skb->users, 1);
+
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb->mac_header = ~0U;
+#endif
+out:
+       return skb;
+}
+
+/**
+ *     __alloc_skb     -       allocate a network buffer
+ *     @size: size to allocate
+ *     @gfp_mask: allocation mask
+ *     @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache
+ *             instead of head cache and allocate a cloned (child) skb.
+ *             If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
+ *             allocations in case the data is required for writeback
+ *     @node: numa node to allocate memory on
+ *
+ *     Allocate a new &sk_buff. The returned buffer has no headroom and a
+ *     tail room of at least size bytes. The object has a reference count
+ *     of one. The return is the buffer. On a failure the return is %NULL.
+ *
+ *     Buffers may only be allocated from interrupts using a @gfp_mask of
+ *     %GFP_ATOMIC.
+ */
+struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
+                           int flags, int node)
+{
+       struct kmem_cache *cache;
+       struct skb_shared_info *shinfo;
+       struct sk_buff *skb;
+       u8 *data;
+       bool pfmemalloc;
+
+       cache = (flags & SKB_ALLOC_FCLONE)
+               ? skbuff_fclone_cache : skbuff_head_cache;
+
+       if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
+               gfp_mask |= __GFP_MEMALLOC;
+
+       /* Get the HEAD */
+       skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
+       if (!skb)
+               goto out;
+       prefetchw(skb);
+
+       /* We do our best to align skb_shared_info on a separate cache
+        * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives
+        * aligned memory blocks, unless SLUB/SLAB debug is enabled.
+        * Both skb->head and skb_shared_info are cache line aligned.
+        */
+       size = SKB_DATA_ALIGN(size);
+       size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+       data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc);
+       if (!data)
+               goto nodata;
+       /* kmalloc(size) might give us more room than requested.
+        * Put skb_shared_info exactly at the end of allocated zone,
+        * to allow max possible filling before reallocation.
+        */
+       size = SKB_WITH_OVERHEAD(ksize(data));
+       prefetchw(data + size);
+
+       /*
+        * Only clear those fields we need to clear, not those that we will
+        * actually initialise below. Hence, don't put any more fields after
+        * the tail pointer in struct sk_buff!
+        */
+       memset(skb, 0, offsetof(struct sk_buff, tail));
+       /* Account for allocated memory : skb + skb->head */
+       skb->truesize = SKB_TRUESIZE(size);
+       skb->pfmemalloc = pfmemalloc;
+       atomic_set(&skb->users, 1);
+       skb->head = data;
+       skb->data = data;
+       skb_reset_tail_pointer(skb);
+       skb->end = skb->tail + size;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb->mac_header = ~0U;
+       skb->transport_header = ~0U;
+#endif
+
+       /* make sure we initialize shinfo sequentially */
+       shinfo = skb_shinfo(skb);
+       memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
+       atomic_set(&shinfo->dataref, 1);
+       kmemcheck_annotate_variable(shinfo->destructor_arg);
+
+       if (flags & SKB_ALLOC_FCLONE) {
+               struct sk_buff *child = skb + 1;
+               atomic_t *fclone_ref = (atomic_t *) (child + 1);
+
+               kmemcheck_annotate_bitfield(child, flags1);
+               kmemcheck_annotate_bitfield(child, flags2);
+               skb->fclone = SKB_FCLONE_ORIG;
+               atomic_set(fclone_ref, 1);
+
+               child->fclone = SKB_FCLONE_UNAVAILABLE;
+               child->pfmemalloc = pfmemalloc;
+       }
+out:
+       return skb;
+nodata:
+       kmem_cache_free(cache, skb);
+       skb = NULL;
+       goto out;
+}
+EXPORT_SYMBOL(__alloc_skb);
+
+/**
+ * build_skb - build a network buffer
+ * @data: data buffer provided by caller
+ * @frag_size: size of fragment, or 0 if head was kmalloced
+ *
+ * Allocate a new &sk_buff. Caller provides space holding head and
+ * skb_shared_info. @data must have been allocated by kmalloc()
+ * The return is the new skb buffer.
+ * On a failure the return is %NULL, and @data is not freed.
+ * Notes :
+ *  Before IO, driver allocates only data buffer where NIC put incoming frame
+ *  Driver should add room at head (NET_SKB_PAD) and
+ *  MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info))
+ *  After IO, driver calls build_skb(), to allocate sk_buff and populate it
+ *  before giving packet to stack.
+ *  RX rings only contains data buffers, not full skbs.
+ */
+struct sk_buff *build_skb(void *data, unsigned int frag_size)
+{
+       struct skb_shared_info *shinfo;
+       struct sk_buff *skb;
+       unsigned int size = frag_size ? : ksize(data);
+
+       skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC);
+       if (!skb)
+               return NULL;
+
+       size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+       memset(skb, 0, offsetof(struct sk_buff, tail));
+       skb->truesize = SKB_TRUESIZE(size);
+       skb->head_frag = frag_size != 0;
+       atomic_set(&skb->users, 1);
+       skb->head = data;
+       skb->data = data;
+       skb_reset_tail_pointer(skb);
+       skb->end = skb->tail + size;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb->mac_header = ~0U;
+       skb->transport_header = ~0U;
+#endif
+
+       /* make sure we initialize shinfo sequentially */
+       shinfo = skb_shinfo(skb);
+       memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
+       atomic_set(&shinfo->dataref, 1);
+       kmemcheck_annotate_variable(shinfo->destructor_arg);
+
+       return skb;
+}
+EXPORT_SYMBOL(build_skb);
+
+struct netdev_alloc_cache {
+       struct page_frag        frag;
+       /* we maintain a pagecount bias, so that we dont dirty cache line
+        * containing page->_count every time we allocate a fragment.
+        */
+       unsigned int            pagecnt_bias;
+};
+static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+
+static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
+{
+       struct netdev_alloc_cache *nc;
+       void *data = NULL;
+       int order;
+       unsigned long flags;
+
+       local_irq_save(flags);
+       nc = &__get_cpu_var(netdev_alloc_cache);
+       if (unlikely(!nc->frag.page)) {
+refill:
+               for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) {
+                       gfp_t gfp = gfp_mask;
+
+                       if (order)
+                               gfp |= __GFP_COMP | __GFP_NOWARN;
+                       nc->frag.page = alloc_pages(gfp, order);
+                       if (likely(nc->frag.page))
+                               break;
+                       if (--order < 0)
+                               goto end;
+               }
+               nc->frag.size = PAGE_SIZE << order;
+recycle:
+               atomic_set(&nc->frag.page->_count, NETDEV_PAGECNT_MAX_BIAS);
+               nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS;
+               nc->frag.offset = 0;
+       }
+
+       if (nc->frag.offset + fragsz > nc->frag.size) {
+               /* avoid unnecessary locked operations if possible */
+               if ((atomic_read(&nc->frag.page->_count) == nc->pagecnt_bias) ||
+                   atomic_sub_and_test(nc->pagecnt_bias, &nc->frag.page->_count))
+                       goto recycle;
+               goto refill;
+       }
+
+       data = page_address(nc->frag.page) + nc->frag.offset;
+       nc->frag.offset += fragsz;
+       nc->pagecnt_bias--;
+end:
+       local_irq_restore(flags);
+       return data;
+}
+
+/**
+ * netdev_alloc_frag - allocate a page fragment
+ * @fragsz: fragment size
+ *
+ * Allocates a frag from a page for receive buffer.
+ * Uses GFP_ATOMIC allocations.
+ */
+void *netdev_alloc_frag(unsigned int fragsz)
+{
+       return __netdev_alloc_frag(fragsz, GFP_ATOMIC | __GFP_COLD);
+}
+EXPORT_SYMBOL(netdev_alloc_frag);
+
+/**
+ *     __netdev_alloc_skb - allocate an skbuff for rx on a specific device
+ *     @dev: network device to receive on
+ *     @length: length to allocate
+ *     @gfp_mask: get_free_pages mask, passed to alloc_skb
+ *
+ *     Allocate a new &sk_buff and assign it a usage count of one. The
+ *     buffer has unspecified headroom built in. Users should allocate
+ *     the headroom they think they need without accounting for the
+ *     built in space. The built in space is used for optimisations.
+ *
+ *     %NULL is returned if there is no free memory.
+ */
+struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
+                                  unsigned int length, gfp_t gfp_mask)
+{
+       struct sk_buff *skb = NULL;
+       unsigned int fragsz = SKB_DATA_ALIGN(length + NET_SKB_PAD) +
+                             SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+       if (fragsz <= PAGE_SIZE && !(gfp_mask & (__GFP_WAIT | GFP_DMA))) {
+               void *data;
+
+               if (sk_memalloc_socks())
+                       gfp_mask |= __GFP_MEMALLOC;
+
+               data = __netdev_alloc_frag(fragsz, gfp_mask);
+
+               if (likely(data)) {
+                       skb = build_skb(data, fragsz);
+                       if (unlikely(!skb))
+                               put_page(virt_to_head_page(data));
+               }
+       } else {
+               skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask,
+                                 SKB_ALLOC_RX, NUMA_NO_NODE);
+       }
+       if (likely(skb)) {
+               skb_reserve(skb, NET_SKB_PAD);
+               skb->dev = dev;
+       }
+       return skb;
+}
+EXPORT_SYMBOL(__netdev_alloc_skb);
+
+void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
+                    int size, unsigned int truesize)
+{
+       skb_fill_page_desc(skb, i, page, off, size);
+       skb->len += size;
+       skb->data_len += size;
+       skb->truesize += truesize;
+}
+EXPORT_SYMBOL(skb_add_rx_frag);
+
+static void skb_drop_list(struct sk_buff **listp)
+{
+       kfree_skb_list(*listp);
+       *listp = NULL;
+}
+
+static inline void skb_drop_fraglist(struct sk_buff *skb)
+{
+       skb_drop_list(&skb_shinfo(skb)->frag_list);
+}
+
+static void skb_clone_fraglist(struct sk_buff *skb)
+{
+       struct sk_buff *list;
+
+       skb_walk_frags(skb, list)
+               skb_get(list);
+}
+
+static void skb_free_head(struct sk_buff *skb)
+{
+       if (skb->head_frag)
+               put_page(virt_to_head_page(skb->head));
+       else
+               kfree(skb->head);
+}
+
+static void skb_release_data(struct sk_buff *skb)
+{
+       if (!skb->cloned ||
+           !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
+                              &skb_shinfo(skb)->dataref)) {
+               if (skb_shinfo(skb)->nr_frags) {
+                       int i;
+                       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+                               skb_frag_unref(skb, i);
+               }
+
+               /*
+                * If skb buf is from userspace, we need to notify the caller
+                * the lower device DMA has done;
+                */
+               if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
+                       struct ubuf_info *uarg;
+
+                       uarg = skb_shinfo(skb)->destructor_arg;
+                       if (uarg->callback)
+                               uarg->callback(uarg, true);
+               }
+
+               if (skb_has_frag_list(skb))
+                       skb_drop_fraglist(skb);
+
+               skb_free_head(skb);
+       }
+}
+
+/*
+ *     Free an skbuff by memory without cleaning the state.
+ */
+static void kfree_skbmem(struct sk_buff *skb)
+{
+       struct sk_buff *other;
+       atomic_t *fclone_ref;
+
+       switch (skb->fclone) {
+       case SKB_FCLONE_UNAVAILABLE:
+               kmem_cache_free(skbuff_head_cache, skb);
+               break;
+
+       case SKB_FCLONE_ORIG:
+               fclone_ref = (atomic_t *) (skb + 2);
+               if (atomic_dec_and_test(fclone_ref))
+                       kmem_cache_free(skbuff_fclone_cache, skb);
+               break;
+
+       case SKB_FCLONE_CLONE:
+               fclone_ref = (atomic_t *) (skb + 1);
+               other = skb - 1;
+
+               /* The clone portion is available for
+                * fast-cloning again.
+                */
+               skb->fclone = SKB_FCLONE_UNAVAILABLE;
+
+               if (atomic_dec_and_test(fclone_ref))
+                       kmem_cache_free(skbuff_fclone_cache, other);
+               break;
+       }
+}
+
+static void skb_release_head_state(struct sk_buff *skb)
+{
+       skb_dst_drop(skb);
+#ifdef CONFIG_XFRM
+       secpath_put(skb->sp);
+#endif
+       if (skb->destructor) {
+               WARN_ON(in_irq());
+               skb->destructor(skb);
+       }
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+       nf_conntrack_put(skb->nfct);
+#endif
+#ifdef CONFIG_BRIDGE_NETFILTER
+       nf_bridge_put(skb->nf_bridge);
+#endif
+/* XXX: IS this still necessary? - JHS */
+#ifdef CONFIG_NET_SCHED
+       skb->tc_index = 0;
+#ifdef CONFIG_NET_CLS_ACT
+       skb->tc_verd = 0;
+#endif
+#endif
+}
+
+/* Free everything but the sk_buff shell. */
+static void skb_release_all(struct sk_buff *skb)
+{
+       skb_release_head_state(skb);
+       if (likely(skb->head))
+               skb_release_data(skb);
+}
+
+/**
+ *     __kfree_skb - private function
+ *     @skb: buffer
+ *
+ *     Free an sk_buff. Release anything attached to the buffer.
+ *     Clean the state. This is an internal helper function. Users should
+ *     always call kfree_skb
+ */
+
+void __kfree_skb(struct sk_buff *skb)
+{
+       skb_release_all(skb);
+       kfree_skbmem(skb);
+}
+EXPORT_SYMBOL(__kfree_skb);
+
+/**
+ *     kfree_skb - free an sk_buff
+ *     @skb: buffer to free
+ *
+ *     Drop a reference to the buffer and free it if the usage count has
+ *     hit zero.
+ */
+void kfree_skb(struct sk_buff *skb)
+{
+       if (unlikely(!skb))
+               return;
+       if (likely(atomic_read(&skb->users) == 1))
+               smp_rmb();
+       else if (likely(!atomic_dec_and_test(&skb->users)))
+               return;
+       trace_kfree_skb(skb, __builtin_return_address(0));
+       __kfree_skb(skb);
+}
+EXPORT_SYMBOL(kfree_skb);
+
+void kfree_skb_list(struct sk_buff *segs)
+{
+       while (segs) {
+               struct sk_buff *next = segs->next;
+
+               kfree_skb(segs);
+               segs = next;
+       }
+}
+EXPORT_SYMBOL(kfree_skb_list);
+
+/**
+ *     skb_tx_error - report an sk_buff xmit error
+ *     @skb: buffer that triggered an error
+ *
+ *     Report xmit error if a device callback is tracking this skb.
+ *     skb must be freed afterwards.
+ */
+void skb_tx_error(struct sk_buff *skb)
+{
+       if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
+               struct ubuf_info *uarg;
+
+               uarg = skb_shinfo(skb)->destructor_arg;
+               if (uarg->callback)
+                       uarg->callback(uarg, false);
+               skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
+       }
+}
+EXPORT_SYMBOL(skb_tx_error);
+
+/**
+ *     consume_skb - free an skbuff
+ *     @skb: buffer to free
+ *
+ *     Drop a ref to the buffer and free it if the usage count has hit zero
+ *     Functions identically to kfree_skb, but kfree_skb assumes that the frame
+ *     is being dropped after a failure and notes that
+ */
+void consume_skb(struct sk_buff *skb)
+{
+       if (unlikely(!skb))
+               return;
+       if (likely(atomic_read(&skb->users) == 1))
+               smp_rmb();
+       else if (likely(!atomic_dec_and_test(&skb->users)))
+               return;
+       trace_consume_skb(skb);
+       __kfree_skb(skb);
+}
+EXPORT_SYMBOL(consume_skb);
+
+static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
+{
+       new->tstamp             = old->tstamp;
+       new->dev                = old->dev;
+       new->transport_header   = old->transport_header;
+       new->network_header     = old->network_header;
+       new->mac_header         = old->mac_header;
+       new->inner_transport_header = old->inner_transport_header;
+       new->inner_network_header = old->inner_network_header;
+       new->inner_mac_header = old->inner_mac_header;
+       skb_dst_copy(new, old);
+       new->rxhash             = old->rxhash;
+       new->ooo_okay           = old->ooo_okay;
+       new->l4_rxhash          = old->l4_rxhash;
+       new->no_fcs             = old->no_fcs;
+       new->encapsulation      = old->encapsulation;
+#ifdef CONFIG_XFRM
+       new->sp                 = secpath_get(old->sp);
+#endif
+       memcpy(new->cb, old->cb, sizeof(old->cb));
+       new->csum               = old->csum;
+       new->local_df           = old->local_df;
+       new->pkt_type           = old->pkt_type;
+       new->ip_summed          = old->ip_summed;
+       skb_copy_queue_mapping(new, old);
+       new->priority           = old->priority;
+#if IS_ENABLED(CONFIG_IP_VS)
+       new->ipvs_property      = old->ipvs_property;
+#endif
+       new->pfmemalloc         = old->pfmemalloc;
+       new->protocol           = old->protocol;
+       new->mark               = old->mark;
+       new->skb_iif            = old->skb_iif;
+       __nf_copy(new, old);
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
+       new->nf_trace           = old->nf_trace;
+#endif
+#ifdef CONFIG_NET_SCHED
+       new->tc_index           = old->tc_index;
+#ifdef CONFIG_NET_CLS_ACT
+       new->tc_verd            = old->tc_verd;
+#endif
+#endif
+       new->vlan_proto         = old->vlan_proto;
+       new->vlan_tci           = old->vlan_tci;
+
+       skb_copy_secmark(new, old);
+}
+
+/*
+ * You should not add any new code to this function.  Add it to
+ * __copy_skb_header above instead.
+ */
+static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb)
+{
+#define C(x) n->x = skb->x
+
+       n->next = n->prev = NULL;
+       n->sk = NULL;
+       __copy_skb_header(n, skb);
+
+       C(len);
+       C(data_len);
+       C(mac_len);
+       n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len;
+       n->cloned = 1;
+       n->nohdr = 0;
+       n->destructor = NULL;
+       C(tail);
+       C(end);
+       C(head);
+       C(head_frag);
+       C(data);
+       C(truesize);
+       atomic_set(&n->users, 1);
+
+       atomic_inc(&(skb_shinfo(skb)->dataref));
+       skb->cloned = 1;
+
+       return n;
+#undef C
+}
+
+/**
+ *     skb_morph       -       morph one skb into another
+ *     @dst: the skb to receive the contents
+ *     @src: the skb to supply the contents
+ *
+ *     This is identical to skb_clone except that the target skb is
+ *     supplied by the user.
+ *
+ *     The target skb is returned upon exit.
+ */
+struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src)
+{
+       skb_release_all(dst);
+       return __skb_clone(dst, src);
+}
+EXPORT_SYMBOL_GPL(skb_morph);
+
+/**
+ *     skb_copy_ubufs  -       copy userspace skb frags buffers to kernel
+ *     @skb: the skb to modify
+ *     @gfp_mask: allocation priority
+ *
+ *     This must be called on SKBTX_DEV_ZEROCOPY skb.
+ *     It will copy all frags into kernel and drop the reference
+ *     to userspace pages.
+ *
+ *     If this function is called from an interrupt gfp_mask() must be
+ *     %GFP_ATOMIC.
+ *
+ *     Returns 0 on success or a negative error code on failure
+ *     to allocate kernel memory to copy to.
+ */
+int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
+{
+       int i;
+       int num_frags = skb_shinfo(skb)->nr_frags;
+       struct page *page, *head = NULL;
+       struct ubuf_info *uarg = skb_shinfo(skb)->destructor_arg;
+
+       for (i = 0; i < num_frags; i++) {
+               u8 *vaddr;
+               skb_frag_t *f = &skb_shinfo(skb)->frags[i];
+
+               page = alloc_page(gfp_mask);
+               if (!page) {
+                       while (head) {
+                               struct page *next = (struct page *)head->private;
+                               put_page(head);
+                               head = next;
+                       }
+                       return -ENOMEM;
+               }
+               vaddr = kmap_atomic(skb_frag_page(f));
+               memcpy(page_address(page),
+                      vaddr + f->page_offset, skb_frag_size(f));
+               kunmap_atomic(vaddr);
+               page->private = (unsigned long)head;
+               head = page;
+       }
+
+       /* skb frags release userspace buffers */
+       for (i = 0; i < num_frags; i++)
+               skb_frag_unref(skb, i);
+
+       uarg->callback(uarg, false);
+
+       /* skb frags point to kernel buffers */
+       for (i = num_frags - 1; i >= 0; i--) {
+               __skb_fill_page_desc(skb, i, head, 0,
+                                    skb_shinfo(skb)->frags[i].size);
+               head = (struct page *)head->private;
+       }
+
+       skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(skb_copy_ubufs);
+
+/**
+ *     skb_clone       -       duplicate an sk_buff
+ *     @skb: buffer to clone
+ *     @gfp_mask: allocation priority
+ *
+ *     Duplicate an &sk_buff. The new one is not owned by a socket. Both
+ *     copies share the same packet data but not structure. The new
+ *     buffer has a reference count of 1. If the allocation fails the
+ *     function returns %NULL otherwise the new buffer is returned.
+ *
+ *     If this function is called from an interrupt gfp_mask() must be
+ *     %GFP_ATOMIC.
+ */
+
+struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
+{
+       struct sk_buff *n;
+
+       if (skb_orphan_frags(skb, gfp_mask))
+               return NULL;
+
+       n = skb + 1;
+       if (skb->fclone == SKB_FCLONE_ORIG &&
+           n->fclone == SKB_FCLONE_UNAVAILABLE) {
+               atomic_t *fclone_ref = (atomic_t *) (n + 1);
+               n->fclone = SKB_FCLONE_CLONE;
+               atomic_inc(fclone_ref);
+       } else {
+               if (skb_pfmemalloc(skb))
+                       gfp_mask |= __GFP_MEMALLOC;
+
+               n = kmem_cache_alloc(skbuff_head_cache, gfp_mask);
+               if (!n)
+                       return NULL;
+
+               kmemcheck_annotate_bitfield(n, flags1);
+               kmemcheck_annotate_bitfield(n, flags2);
+               n->fclone = SKB_FCLONE_UNAVAILABLE;
+       }
+
+       return __skb_clone(n, skb);
+}
+EXPORT_SYMBOL(skb_clone);
+
+static void skb_headers_offset_update(struct sk_buff *skb, int off)
+{
+       /* {transport,network,mac}_header and tail are relative to skb->head */
+       skb->transport_header += off;
+       skb->network_header   += off;
+       if (skb_mac_header_was_set(skb))
+               skb->mac_header += off;
+       skb->inner_transport_header += off;
+       skb->inner_network_header += off;
+       skb->inner_mac_header += off;
+}
+
+static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
+{
+#ifndef NET_SKBUFF_DATA_USES_OFFSET
+       /*
+        *      Shift between the two data areas in bytes
+        */
+       unsigned long offset = new->data - old->data;
+#endif
+
+       __copy_skb_header(new, old);
+
+#ifndef NET_SKBUFF_DATA_USES_OFFSET
+       skb_headers_offset_update(new, offset);
+#endif
+       skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size;
+       skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
+       skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type;
+}
+
+static inline int skb_alloc_rx_flag(const struct sk_buff *skb)
+{
+       if (skb_pfmemalloc(skb))
+               return SKB_ALLOC_RX;
+       return 0;
+}
+
+/**
+ *     skb_copy        -       create private copy of an sk_buff
+ *     @skb: buffer to copy
+ *     @gfp_mask: allocation priority
+ *
+ *     Make a copy of both an &sk_buff and its data. This is used when the
+ *     caller wishes to modify the data and needs a private copy of the
+ *     data to alter. Returns %NULL on failure or the pointer to the buffer
+ *     on success. The returned buffer has a reference count of 1.
+ *
+ *     As by-product this function converts non-linear &sk_buff to linear
+ *     one, so that &sk_buff becomes completely private and caller is allowed
+ *     to modify all the data of returned buffer. This means that this
+ *     function is not recommended for use in circumstances when only
+ *     header is going to be modified. Use pskb_copy() instead.
+ */
+
+struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
+{
+       int headerlen = skb_headroom(skb);
+       unsigned int size = skb_end_offset(skb) + skb->data_len;
+       struct sk_buff *n = __alloc_skb(size, gfp_mask,
+                                       skb_alloc_rx_flag(skb), NUMA_NO_NODE);
+
+       if (!n)
+               return NULL;
+
+       /* Set the data pointer */
+       skb_reserve(n, headerlen);
+       /* Set the tail pointer and length */
+       skb_put(n, skb->len);
+
+       if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len))
+               BUG();
+
+       copy_skb_header(n, skb);
+       return n;
+}
+EXPORT_SYMBOL(skb_copy);
+
+/**
+ *     __pskb_copy     -       create copy of an sk_buff with private head.
+ *     @skb: buffer to copy
+ *     @headroom: headroom of new skb
+ *     @gfp_mask: allocation priority
+ *
+ *     Make a copy of both an &sk_buff and part of its data, located
+ *     in header. Fragmented data remain shared. This is used when
+ *     the caller wishes to modify only header of &sk_buff and needs
+ *     private copy of the header to alter. Returns %NULL on failure
+ *     or the pointer to the buffer on success.
+ *     The returned buffer has a reference count of 1.
+ */
+
+struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask)
+{
+       unsigned int size = skb_headlen(skb) + headroom;
+       struct sk_buff *n = __alloc_skb(size, gfp_mask,
+                                       skb_alloc_rx_flag(skb), NUMA_NO_NODE);
+
+       if (!n)
+               goto out;
+
+       /* Set the data pointer */
+       skb_reserve(n, headroom);
+       /* Set the tail pointer and length */
+       skb_put(n, skb_headlen(skb));
+       /* Copy the bytes */
+       skb_copy_from_linear_data(skb, n->data, n->len);
+
+       n->truesize += skb->data_len;
+       n->data_len  = skb->data_len;
+       n->len       = skb->len;
+
+       if (skb_shinfo(skb)->nr_frags) {
+               int i;
+
+               if (skb_orphan_frags(skb, gfp_mask)) {
+                       kfree_skb(n);
+                       n = NULL;
+                       goto out;
+               }
+               for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+                       skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
+                       skb_frag_ref(skb, i);
+               }
+               skb_shinfo(n)->nr_frags = i;
+       }
+
+       if (skb_has_frag_list(skb)) {
+               skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list;
+               skb_clone_fraglist(n);
+       }
+
+       copy_skb_header(n, skb);
+out:
+       return n;
+}
+EXPORT_SYMBOL(__pskb_copy);
+
+/**
+ *     pskb_expand_head - reallocate header of &sk_buff
+ *     @skb: buffer to reallocate
+ *     @nhead: room to add at head
+ *     @ntail: room to add at tail
+ *     @gfp_mask: allocation priority
+ *
+ *     Expands (or creates identical copy, if &nhead and &ntail are zero)
+ *     header of skb. &sk_buff itself is not changed. &sk_buff MUST have
+ *     reference count of 1. Returns zero in the case of success or error,
+ *     if expansion failed. In the last case, &sk_buff is not changed.
+ *
+ *     All the pointers pointing into skb header may change and must be
+ *     reloaded after call to this function.
+ */
+
+int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
+                    gfp_t gfp_mask)
+{
+       int i;
+       u8 *data;
+       int size = nhead + skb_end_offset(skb) + ntail;
+       long off;
+
+       BUG_ON(nhead < 0);
+
+       if (skb_shared(skb))
+               BUG();
+
+       size = SKB_DATA_ALIGN(size);
+
+       if (skb_pfmemalloc(skb))
+               gfp_mask |= __GFP_MEMALLOC;
+       data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
+                              gfp_mask, NUMA_NO_NODE, NULL);
+       if (!data)
+               goto nodata;
+       size = SKB_WITH_OVERHEAD(ksize(data));
+
+       /* Copy only real data... and, alas, header. This should be
+        * optimized for the cases when header is void.
+        */
+       memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);
+
+       memcpy((struct skb_shared_info *)(data + size),
+              skb_shinfo(skb),
+              offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));
+
+       /*
+        * if shinfo is shared we must drop the old head gracefully, but if it
+        * is not we can just drop the old head and let the existing refcount
+        * be since all we did is relocate the values
+        */
+       if (skb_cloned(skb)) {
+               /* copy this zero copy skb frags */
+               if (skb_orphan_frags(skb, gfp_mask))
+                       goto nofrags;
+               for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+                       skb_frag_ref(skb, i);
+
+               if (skb_has_frag_list(skb))
+                       skb_clone_fraglist(skb);
+
+               skb_release_data(skb);
+       } else {
+               skb_free_head(skb);
+       }
+       off = (data + nhead) - skb->head;
+
+       skb->head     = data;
+       skb->head_frag = 0;
+       skb->data    += off;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb->end      = size;
+       off           = nhead;
+#else
+       skb->end      = skb->head + size;
+#endif
+       skb->tail             += off;
+       skb_headers_offset_update(skb, off);
+       /* Only adjust this if it actually is csum_start rather than csum */
+       if (skb->ip_summed == CHECKSUM_PARTIAL)
+               skb->csum_start += nhead;
+       skb->cloned   = 0;
+       skb->hdr_len  = 0;
+       skb->nohdr    = 0;
+       atomic_set(&skb_shinfo(skb)->dataref, 1);
+       return 0;
+
+nofrags:
+       kfree(data);
+nodata:
+       return -ENOMEM;
+}
+EXPORT_SYMBOL(pskb_expand_head);
+
+/* Make private copy of skb with writable head and some headroom */
+
+struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom)
+{
+       struct sk_buff *skb2;
+       int delta = headroom - skb_headroom(skb);
+
+       if (delta <= 0)
+               skb2 = pskb_copy(skb, GFP_ATOMIC);
+       else {
+               skb2 = skb_clone(skb, GFP_ATOMIC);
+               if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0,
+                                            GFP_ATOMIC)) {
+                       kfree_skb(skb2);
+                       skb2 = NULL;
+               }
+       }
+       return skb2;
+}
+EXPORT_SYMBOL(skb_realloc_headroom);
+
+/**
+ *     skb_copy_expand -       copy and expand sk_buff
+ *     @skb: buffer to copy
+ *     @newheadroom: new free bytes at head
+ *     @newtailroom: new free bytes at tail
+ *     @gfp_mask: allocation priority
+ *
+ *     Make a copy of both an &sk_buff and its data and while doing so
+ *     allocate additional space.
+ *
+ *     This is used when the caller wishes to modify the data and needs a
+ *     private copy of the data to alter as well as more space for new fields.
+ *     Returns %NULL on failure or the pointer to the buffer
+ *     on success. The returned buffer has a reference count of 1.
+ *
+ *     You must pass %GFP_ATOMIC as the allocation priority if this function
+ *     is called from an interrupt.
+ */
+struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
+                               int newheadroom, int newtailroom,
+                               gfp_t gfp_mask)
+{
+       /*
+        *      Allocate the copy buffer
+        */
+       struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom,
+                                       gfp_mask, skb_alloc_rx_flag(skb),
+                                       NUMA_NO_NODE);
+       int oldheadroom = skb_headroom(skb);
+       int head_copy_len, head_copy_off;
+       int off;
+
+       if (!n)
+               return NULL;
+
+       skb_reserve(n, newheadroom);
+
+       /* Set the tail pointer and length */
+       skb_put(n, skb->len);
+
+       head_copy_len = oldheadroom;
+       head_copy_off = 0;
+       if (newheadroom <= head_copy_len)
+               head_copy_len = newheadroom;
+       else
+               head_copy_off = newheadroom - head_copy_len;
+
+       /* Copy the linear header and data. */
+       if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off,
+                         skb->len + head_copy_len))
+               BUG();
+
+       copy_skb_header(n, skb);
+
+       off                  = newheadroom - oldheadroom;
+       if (n->ip_summed == CHECKSUM_PARTIAL)
+               n->csum_start += off;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+       skb_headers_offset_update(n, off);
+#endif
+
+       return n;
+}
+EXPORT_SYMBOL(skb_copy_expand);
+
+/**
+ *     skb_pad                 -       zero pad the tail of an skb
+ *     @skb: buffer to pad
+ *     @pad: space to pad
+ *
+ *     Ensure that a buffer is followed by a padding area that is zero
+ *     filled. Used by network drivers which may DMA or transfer data
+ *     beyond the buffer end onto the wire.
+ *
+ *     May return error in out of memory cases. The skb is freed on error.
+ */
+
+int skb_pad(struct sk_buff *skb, int pad)
+{
+       int err;
+       int ntail;
+
+       /* If the skbuff is non linear tailroom is always zero.. */
+       if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) {
+               memset(skb->data+skb->len, 0, pad);
+               return 0;
+       }
+
+       ntail = skb->data_len + pad - (skb->end - skb->tail);
+       if (likely(skb_cloned(skb) || ntail > 0)) {
+               err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC);
+               if (unlikely(err))
+                       goto free_skb;
+       }
+
+       /* FIXME: The use of this function with non-linear skb's really needs
+        * to be audited.
+        */
+       err = skb_linearize(skb);
+       if (unlikely(err))
+               goto free_skb;
+
+       memset(skb->data + skb->len, 0, pad);
+       return 0;
+
+free_skb:
+       kfree_skb(skb);
+       return err;
+}
+EXPORT_SYMBOL(skb_pad);
+
+/**
+ *     skb_put - add data to a buffer
+ *     @skb: buffer to use
+ *     @len: amount of data to add
+ *
+ *     This function extends the used data area of the buffer. If this would
+ *     exceed the total buffer size the kernel will panic. A pointer to the
+ *     first byte of the extra data is returned.
+ */
+unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
+{
+       unsigned char *tmp = skb_tail_pointer(skb);
+       SKB_LINEAR_ASSERT(skb);
+       skb->tail += len;
+       skb->len  += len;
+       if (unlikely(skb->tail > skb->end))
+               skb_over_panic(skb, len, __builtin_return_address(0));
+       return tmp;
+}
+EXPORT_SYMBOL(skb_put);
+
+/**
+ *     skb_push - add data to the start of a buffer
+ *     @skb: buffer to use
+ *     @len: amount of data to add
+ *
+ *     This function extends the used data area of the buffer at the buffer
+ *     start. If this would exceed the total buffer headroom the kernel will
+ *     panic. A pointer to the first byte of the extra data is returned.
+ */
+unsigned char *skb_push(struct sk_buff *skb, unsigned int len)
+{
+       skb->data -= len;
+       skb->len  += len;
+       if (unlikely(skb->data<skb->head))
+               skb_under_panic(skb, len, __builtin_return_address(0));
+       return skb->data;
+}
+EXPORT_SYMBOL(skb_push);
+
+/**
+ *     skb_pull - remove data from the start of a buffer
+ *     @skb: buffer to use
+ *     @len: amount of data to remove
+ *
+ *     This function removes data from the start of a buffer, returning
+ *     the memory to the headroom. A pointer to the next data in the buffer
+ *     is returned. Once the data has been pulled future pushes will overwrite
+ *     the old data.
+ */
+unsigned char *skb_pull(struct sk_buff *skb, unsigned int len)
+{
+       return skb_pull_inline(skb, len);
+}
+EXPORT_SYMBOL(skb_pull);
+
+/**
+ *     skb_trim - remove end from a buffer
+ *     @skb: buffer to alter
+ *     @len: new length
+ *
+ *     Cut the length of a buffer down by removing data from the tail. If
+ *     the buffer is already under the length specified it is not modified.
+ *     The skb must be linear.
+ */
+void skb_trim(struct sk_buff *skb, unsigned int len)
+{
+       if (skb->len > len)
+               __skb_trim(skb, len);
+}
+EXPORT_SYMBOL(skb_trim);
+
+/* Trims skb to length len. It can change skb pointers.
+ */
+
+int ___pskb_trim(struct sk_buff *skb, unsigned int len)
+{
+       struct sk_buff **fragp;
+       struct sk_buff *frag;
+       int offset = skb_headlen(skb);
+       int nfrags = skb_shinfo(skb)->nr_frags;
+       int i;
+       int err;
+
+       if (skb_cloned(skb) &&
+           unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
+               return err;
+
+       i = 0;
+       if (offset >= len)
+               goto drop_pages;
+
+       for (; i < nfrags; i++) {
+               int end = offset + skb_frag_size(&skb_shinfo(skb)->frags[i]);
+
+               if (end < len) {
+                       offset = end;
+                       continue;
+               }
+
+               skb_frag_size_set(&skb_shinfo(skb)->frags[i++], len - offset);
+
+drop_pages:
+               skb_shinfo(skb)->nr_frags = i;
+
+               for (; i < nfrags; i++)
+                       skb_frag_unref(skb, i);
+
+               if (skb_has_frag_list(skb))
+                       skb_drop_fraglist(skb);
+               goto done;
+       }
+
+       for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp);
+            fragp = &frag->next) {
+               int end = offset + frag->len;
+
+               if (skb_shared(frag)) {
+                       struct sk_buff *nfrag;
+
+                       nfrag = skb_clone(frag, GFP_ATOMIC);
+                       if (unlikely(!nfrag))
+                               return -ENOMEM;
+
+                       nfrag->next = frag->next;
+                       consume_skb(frag);
+                       frag = nfrag;
+                       *fragp = frag;
+               }
+
+               if (end < len) {
+                       offset = end;
+                       continue;
+               }
+
+               if (end > len &&
+                   unlikely((err = pskb_trim(frag, len - offset))))
+                       return err;
+
+               if (frag->next)
+                       skb_drop_list(&frag->next);
+               break;
+       }
+
+done:
+       if (len > skb_headlen(skb)) {
+               skb->data_len -= skb->len - len;
+               skb->len       = len;
+       } else {
+               skb->len       = len;
+               skb->data_len  = 0;
+               skb_set_tail_pointer(skb, len);
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(___pskb_trim);
+
+/**
+ *     __pskb_pull_tail - advance tail of skb header
+ *     @skb: buffer to reallocate
+ *     @delta: number of bytes to advance tail
+ *
+ *     The function makes a sense only on a fragmented &sk_buff,
+ *     it expands header moving its tail forward and copying necessary
+ *     data from fragmented part.
+ *
+ *     &sk_buff MUST have reference count of 1.
+ *
+ *     Returns %NULL (and &sk_buff does not change) if pull failed
+ *     or value of new tail of skb in the case of success.
+ *
+ *     All the pointers pointing into skb header may change and must be
+ *     reloaded after call to this function.
+ */
+
+/* Moves tail of skb head forward, copying data from fragmented part,
+ * when it is necessary.
+ * 1. It may fail due to malloc failure.
+ * 2. It may change skb pointers.
+ *
+ * It is pretty complicated. Luckily, it is called only in exceptional cases.
+ */
+unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta)
+{
+       /* If skb has not enough free space at tail, get new one
+        * plus 128 bytes for future expansions. If we have enough
+        * room at tail, reallocate without expansion only if skb is cloned.
+        */
+       int i, k, eat = (skb->tail + delta) - skb->end;
+
+       if (eat > 0 || skb_cloned(skb)) {
+               if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
+                                    GFP_ATOMIC))
+                       return NULL;
+       }
+
+       if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta))
+               BUG();
+
+       /* Optimization: no fragments, no reasons to preestimate
+        * size of pulled pages. Superb.
+        */
+       if (!skb_has_frag_list(skb))
+               goto pull_pages;
+
+       /* Estimate size of pulled pages. */
+       eat = delta;
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+
+               if (size >= eat)
+                       goto pull_pages;
+               eat -= size;
+       }
+
+       /* If we need update frag list, we are in troubles.
+        * Certainly, it possible to add an offset to skb data,
+        * but taking into account that pulling is expected to
+        * be very rare operation, it is worth to fight against
+        * further bloating skb head and crucify ourselves here instead.
+        * Pure masohism, indeed. 8)8)
+        */
+       if (eat) {
+               struct sk_buff *list = skb_shinfo(skb)->frag_list;
+               struct sk_buff *clone = NULL;
+               struct sk_buff *insp = NULL;
+
+               do {
+                       BUG_ON(!list);
+
+                       if (list->len <= eat) {
+                               /* Eaten as whole. */
+                               eat -= list->len;
+                               list = list->next;
+                               insp = list;
+                       } else {
+                               /* Eaten partially. */
+
+                               if (skb_shared(list)) {
+                                       /* Sucks! We need to fork list. :-( */
+                                       clone = skb_clone(list, GFP_ATOMIC);
+                                       if (!clone)
+                                               return NULL;
+                                       insp = list->next;
+                                       list = clone;
+                               } else {
+                                       /* This may be pulled without
+                                        * problems. */
+                                       insp = list;
+                               }
+                               if (!pskb_pull(list, eat)) {
+                                       kfree_skb(clone);
+                                       return NULL;
+                               }
+                               break;
+                       }
+               } while (eat);
+
+               /* Free pulled out fragments. */
+               while ((list = skb_shinfo(skb)->frag_list) != insp) {
+                       skb_shinfo(skb)->frag_list = list->next;
+                       kfree_skb(list);
+               }
+               /* And insert new clone at head. */
+               if (clone) {
+                       clone->next = list;
+                       skb_shinfo(skb)->frag_list = clone;
+               }
+       }
+       /* Success! Now we may commit changes to skb data. */
+
+pull_pages:
+       eat = delta;
+       k = 0;
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+
+               if (size <= eat) {
+                       skb_frag_unref(skb, i);
+                       eat -= size;
+               } else {
+                       skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i];
+                       if (eat) {
+                               skb_shinfo(skb)->frags[k].page_offset += eat;
+                               skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
+                               eat = 0;
+                       }
+                       k++;
+               }
+       }
+       skb_shinfo(skb)->nr_frags = k;
+
+       skb->tail     += delta;
+       skb->data_len -= delta;
+
+       return skb_tail_pointer(skb);
+}
+EXPORT_SYMBOL(__pskb_pull_tail);
+
+/**
+ *     skb_copy_bits - copy bits from skb to kernel buffer
+ *     @skb: source skb
+ *     @offset: offset in source
+ *     @to: destination buffer
+ *     @len: number of bytes to copy
+ *
+ *     Copy the specified number of bytes from the source skb to the
+ *     destination buffer.
+ *
+ *     CAUTION ! :
+ *             If its prototype is ever changed,
+ *             check arch/{*}/net/{*}.S files,
+ *             since it is called from BPF assembly code.
+ */
+int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
+{
+       int start = skb_headlen(skb);
+       struct sk_buff *frag_iter;
+       int i, copy;
+
+       if (offset > (int)skb->len - len)
+               goto fault;
+
+       /* Copy header. */
+       if ((copy = start - offset) > 0) {
+               if (copy > len)
+                       copy = len;
+               skb_copy_from_linear_data_offset(skb, offset, to, copy);
+               if ((len -= copy) == 0)
+                       return 0;
+               offset += copy;
+               to     += copy;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int end;
+               skb_frag_t *f = &skb_shinfo(skb)->frags[i];
+
+               WARN_ON(start > offset + len);
+
+               end = start + skb_frag_size(f);
+               if ((copy = end - offset) > 0) {
+                       u8 *vaddr;
+
+                       if (copy > len)
+                               copy = len;
+
+                       vaddr = kmap_atomic(skb_frag_page(f));
+                       memcpy(to,
+                              vaddr + f->page_offset + offset - start,
+                              copy);
+                       kunmap_atomic(vaddr);
+
+                       if ((len -= copy) == 0)
+                               return 0;
+                       offset += copy;
+                       to     += copy;
+               }
+               start = end;
+       }
+
+       skb_walk_frags(skb, frag_iter) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + frag_iter->len;
+               if ((copy = end - offset) > 0) {
+                       if (copy > len)
+                               copy = len;
+                       if (skb_copy_bits(frag_iter, offset - start, to, copy))
+                               goto fault;
+                       if ((len -= copy) == 0)
+                               return 0;
+                       offset += copy;
+                       to     += copy;
+               }
+               start = end;
+       }
+
+       if (!len)
+               return 0;
+
+fault:
+       return -EFAULT;
+}
+EXPORT_SYMBOL(skb_copy_bits);
+
+/*
+ * Callback from splice_to_pipe(), if we need to release some pages
+ * at the end of the spd in case we error'ed out in filling the pipe.
+ */
+static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+       put_page(spd->pages[i]);
+}
+
+static struct page *linear_to_page(struct page *page, unsigned int *len,
+                                  unsigned int *offset,
+                                  struct sock *sk)
+{
+       struct page_frag *pfrag = sk_page_frag(sk);
+
+       if (!sk_page_frag_refill(sk, pfrag))
+               return NULL;
+
+       *len = min_t(unsigned int, *len, pfrag->size - pfrag->offset);
+
+       memcpy(page_address(pfrag->page) + pfrag->offset,
+              page_address(page) + *offset, *len);
+       *offset = pfrag->offset;
+       pfrag->offset += *len;
+
+       return pfrag->page;
+}
+
+static bool spd_can_coalesce(const struct splice_pipe_desc *spd,
+                            struct page *page,
+                            unsigned int offset)
+{
+       return  spd->nr_pages &&
+               spd->pages[spd->nr_pages - 1] == page &&
+               (spd->partial[spd->nr_pages - 1].offset +
+                spd->partial[spd->nr_pages - 1].len == offset);
+}
+
+/*
+ * Fill page/offset/length into spd, if it can hold more pages.
+ */
+static bool spd_fill_page(struct splice_pipe_desc *spd,
+                         struct pipe_inode_info *pipe, struct page *page,
+                         unsigned int *len, unsigned int offset,
+                         bool linear,
+                         struct sock *sk)
+{
+       if (unlikely(spd->nr_pages == MAX_SKB_FRAGS))
+               return true;
+
+       if (linear) {
+               page = linear_to_page(page, len, &offset, sk);
+               if (!page)
+                       return true;
+       }
+       if (spd_can_coalesce(spd, page, offset)) {
+               spd->partial[spd->nr_pages - 1].len += *len;
+               return false;
+       }
+       get_page(page);
+       spd->pages[spd->nr_pages] = page;
+       spd->partial[spd->nr_pages].len = *len;
+       spd->partial[spd->nr_pages].offset = offset;
+       spd->nr_pages++;
+
+       return false;
+}
+
+static bool __splice_segment(struct page *page, unsigned int poff,
+                            unsigned int plen, unsigned int *off,
+                            unsigned int *len,
+                            struct splice_pipe_desc *spd, bool linear,
+                            struct sock *sk,
+                            struct pipe_inode_info *pipe)
+{
+       if (!*len)
+               return true;
+
+       /* skip this segment if already processed */
+       if (*off >= plen) {
+               *off -= plen;
+               return false;
+       }
+
+       /* ignore any bits we already processed */
+       poff += *off;
+       plen -= *off;
+       *off = 0;
+
+       do {
+               unsigned int flen = min(*len, plen);
+
+               if (spd_fill_page(spd, pipe, page, &flen, poff,
+                                 linear, sk))
+                       return true;
+               poff += flen;
+               plen -= flen;
+               *len -= flen;
+       } while (*len && plen);
+
+       return false;
+}
+
+/*
+ * Map linear and fragment data from the skb to spd. It reports true if the
+ * pipe is full or if we already spliced the requested length.
+ */
+static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
+                             unsigned int *offset, unsigned int *len,
+                             struct splice_pipe_desc *spd, struct sock *sk)
+{
+       int seg;
+
+       /* map the linear part :
+        * If skb->head_frag is set, this 'linear' part is backed by a
+        * fragment, and if the head is not shared with any clones then
+        * we can avoid a copy since we own the head portion of this page.
+        */
+       if (__splice_segment(virt_to_page(skb->data),
+                            (unsigned long) skb->data & (PAGE_SIZE - 1),
+                            skb_headlen(skb),
+                            offset, len, spd,
+                            skb_head_is_locked(skb),
+                            sk, pipe))
+               return true;
+
+       /*
+        * then map the fragments
+        */
+       for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
+               const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
+
+               if (__splice_segment(skb_frag_page(f),
+                                    f->page_offset, skb_frag_size(f),
+                                    offset, len, spd, false, sk, pipe))
+                       return true;
+       }
+
+       return false;
+}
+
+/*
+ * Map data from the skb to a pipe. Should handle both the linear part,
+ * the fragments, and the frag list. It does NOT handle frag lists within
+ * the frag list, if such a thing exists. We'd probably need to recurse to
+ * handle that cleanly.
+ */
+int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
+                   struct pipe_inode_info *pipe, unsigned int tlen,
+                   unsigned int flags)
+{
+       struct partial_page partial[MAX_SKB_FRAGS];
+       struct page *pages[MAX_SKB_FRAGS];
+       struct splice_pipe_desc spd = {
+               .pages = pages,
+               .partial = partial,
+               .nr_pages_max = MAX_SKB_FRAGS,
+               .flags = flags,
+               .ops = &sock_pipe_buf_ops,
+               .spd_release = sock_spd_release,
+       };
+       struct sk_buff *frag_iter;
+       struct sock *sk = skb->sk;
+       int ret = 0;
+
+       /*
+        * __skb_splice_bits() only fails if the output has no room left,
+        * so no point in going over the frag_list for the error case.
+        */
+       if (__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk))
+               goto done;
+       else if (!tlen)
+               goto done;
+
+       /*
+        * now see if we have a frag_list to map
+        */
+       skb_walk_frags(skb, frag_iter) {
+               if (!tlen)
+                       break;
+               if (__skb_splice_bits(frag_iter, pipe, &offset, &tlen, &spd, sk))
+                       break;
+       }
+
+done:
+       if (spd.nr_pages) {
+               /*
+                * Drop the socket lock, otherwise we have reverse
+                * locking dependencies between sk_lock and i_mutex
+                * here as compared to sendfile(). We enter here
+                * with the socket lock held, and splice_to_pipe() will
+                * grab the pipe inode lock. For sendfile() emulation,
+                * we call into ->sendpage() with the i_mutex lock held
+                * and networking will grab the socket lock.
+                */
+               release_sock(sk);
+               ret = splice_to_pipe(pipe, &spd);
+               lock_sock(sk);
+       }
+
+       return ret;
+}
+
+/**
+ *     skb_store_bits - store bits from kernel buffer to skb
+ *     @skb: destination buffer
+ *     @offset: offset in destination
+ *     @from: source buffer
+ *     @len: number of bytes to copy
+ *
+ *     Copy the specified number of bytes from the source buffer to the
+ *     destination skb.  This function handles all the messy bits of
+ *     traversing fragment lists and such.
+ */
+
+int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len)
+{
+       int start = skb_headlen(skb);
+       struct sk_buff *frag_iter;
+       int i, copy;
+
+       if (offset > (int)skb->len - len)
+               goto fault;
+
+       if ((copy = start - offset) > 0) {
+               if (copy > len)
+                       copy = len;
+               skb_copy_to_linear_data_offset(skb, offset, from, copy);
+               if ((len -= copy) == 0)
+                       return 0;
+               offset += copy;
+               from += copy;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + skb_frag_size(frag);
+               if ((copy = end - offset) > 0) {
+                       u8 *vaddr;
+
+                       if (copy > len)
+                               copy = len;
+
+                       vaddr = kmap_atomic(skb_frag_page(frag));
+                       memcpy(vaddr + frag->page_offset + offset - start,
+                              from, copy);
+                       kunmap_atomic(vaddr);
+
+                       if ((len -= copy) == 0)
+                               return 0;
+                       offset += copy;
+                       from += copy;
+               }
+               start = end;
+       }
+
+       skb_walk_frags(skb, frag_iter) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + frag_iter->len;
+               if ((copy = end - offset) > 0) {
+                       if (copy > len)
+                               copy = len;
+                       if (skb_store_bits(frag_iter, offset - start,
+                                          from, copy))
+                               goto fault;
+                       if ((len -= copy) == 0)
+                               return 0;
+                       offset += copy;
+                       from += copy;
+               }
+               start = end;
+       }
+       if (!len)
+               return 0;
+
+fault:
+       return -EFAULT;
+}
+EXPORT_SYMBOL(skb_store_bits);
+
+/* Checksum skb data. */
+
+__wsum skb_checksum(const struct sk_buff *skb, int offset,
+                         int len, __wsum csum)
+{
+       int start = skb_headlen(skb);
+       int i, copy = start - offset;
+       struct sk_buff *frag_iter;
+       int pos = 0;
+
+       /* Checksum header. */
+       if (copy > 0) {
+               if (copy > len)
+                       copy = len;
+               csum = csum_partial(skb->data + offset, copy, csum);
+               if ((len -= copy) == 0)
+                       return csum;
+               offset += copy;
+               pos     = copy;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int end;
+               skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+               WARN_ON(start > offset + len);
+
+               end = start + skb_frag_size(frag);
+               if ((copy = end - offset) > 0) {
+                       __wsum csum2;
+                       u8 *vaddr;
+
+                       if (copy > len)
+                               copy = len;
+                       vaddr = kmap_atomic(skb_frag_page(frag));
+                       csum2 = csum_partial(vaddr + frag->page_offset +
+                                            offset - start, copy, 0);
+                       kunmap_atomic(vaddr);
+                       csum = csum_block_add(csum, csum2, pos);
+                       if (!(len -= copy))
+                               return csum;
+                       offset += copy;
+                       pos    += copy;
+               }
+               start = end;
+       }
+
+       skb_walk_frags(skb, frag_iter) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + frag_iter->len;
+               if ((copy = end - offset) > 0) {
+                       __wsum csum2;
+                       if (copy > len)
+                               copy = len;
+                       csum2 = skb_checksum(frag_iter, offset - start,
+                                            copy, 0);
+                       csum = csum_block_add(csum, csum2, pos);
+                       if ((len -= copy) == 0)
+                               return csum;
+                       offset += copy;
+                       pos    += copy;
+               }
+               start = end;
+       }
+       BUG_ON(len);
+
+       return csum;
+}
+EXPORT_SYMBOL(skb_checksum);
+
+/* Both of above in one bottle. */
+
+__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
+                                   u8 *to, int len, __wsum csum)
+{
+       int start = skb_headlen(skb);
+       int i, copy = start - offset;
+       struct sk_buff *frag_iter;
+       int pos = 0;
+
+       /* Copy header. */
+       if (copy > 0) {
+               if (copy > len)
+                       copy = len;
+               csum = csum_partial_copy_nocheck(skb->data + offset, to,
+                                                copy, csum);
+               if ((len -= copy) == 0)
+                       return csum;
+               offset += copy;
+               to     += copy;
+               pos     = copy;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
+               if ((copy = end - offset) > 0) {
+                       __wsum csum2;
+                       u8 *vaddr;
+                       skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+                       if (copy > len)
+                               copy = len;
+                       vaddr = kmap_atomic(skb_frag_page(frag));
+                       csum2 = csum_partial_copy_nocheck(vaddr +
+                                                         frag->page_offset +
+                                                         offset - start, to,
+                                                         copy, 0);
+                       kunmap_atomic(vaddr);
+                       csum = csum_block_add(csum, csum2, pos);
+                       if (!(len -= copy))
+                               return csum;
+                       offset += copy;
+                       to     += copy;
+                       pos    += copy;
+               }
+               start = end;
+       }
+
+       skb_walk_frags(skb, frag_iter) {
+               __wsum csum2;
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + frag_iter->len;
+               if ((copy = end - offset) > 0) {
+                       if (copy > len)
+                               copy = len;
+                       csum2 = skb_copy_and_csum_bits(frag_iter,
+                                                      offset - start,
+                                                      to, copy, 0);
+                       csum = csum_block_add(csum, csum2, pos);
+                       if ((len -= copy) == 0)
+                               return csum;
+                       offset += copy;
+                       to     += copy;
+                       pos    += copy;
+               }
+               start = end;
+       }
+       BUG_ON(len);
+       return csum;
+}
+EXPORT_SYMBOL(skb_copy_and_csum_bits);
+
+void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
+{
+       __wsum csum;
+       long csstart;
+
+       if (skb->ip_summed == CHECKSUM_PARTIAL)
+               csstart = skb_checksum_start_offset(skb);
+       else
+               csstart = skb_headlen(skb);
+
+       BUG_ON(csstart > skb_headlen(skb));
+
+       skb_copy_from_linear_data(skb, to, csstart);
+
+       csum = 0;
+       if (csstart != skb->len)
+               csum = skb_copy_and_csum_bits(skb, csstart, to + csstart,
+                                             skb->len - csstart, 0);
+
+       if (skb->ip_summed == CHECKSUM_PARTIAL) {
+               long csstuff = csstart + skb->csum_offset;
+
+               *((__sum16 *)(to + csstuff)) = csum_fold(csum);
+       }
+}
+EXPORT_SYMBOL(skb_copy_and_csum_dev);
+
+/**
+ *     skb_dequeue - remove from the head of the queue
+ *     @list: list to dequeue from
+ *
+ *     Remove the head of the list. The list lock is taken so the function
+ *     may be used safely with other locking list functions. The head item is
+ *     returned or %NULL if the list is empty.
+ */
+
+struct sk_buff *skb_dequeue(struct sk_buff_head *list)
+{
+       unsigned long flags;
+       struct sk_buff *result;
+
+       spin_lock_irqsave(&list->lock, flags);
+       result = __skb_dequeue(list);
+       spin_unlock_irqrestore(&list->lock, flags);
+       return result;
+}
+EXPORT_SYMBOL(skb_dequeue);
+
+/**
+ *     skb_dequeue_tail - remove from the tail of the queue
+ *     @list: list to dequeue from
+ *
+ *     Remove the tail of the list. The list lock is taken so the function
+ *     may be used safely with other locking list functions. The tail item is
+ *     returned or %NULL if the list is empty.
+ */
+struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list)
+{
+       unsigned long flags;
+       struct sk_buff *result;
+
+       spin_lock_irqsave(&list->lock, flags);
+       result = __skb_dequeue_tail(list);
+       spin_unlock_irqrestore(&list->lock, flags);
+       return result;
+}
+EXPORT_SYMBOL(skb_dequeue_tail);
+
+/**
+ *     skb_queue_purge - empty a list
+ *     @list: list to empty
+ *
+ *     Delete all buffers on an &sk_buff list. Each buffer is removed from
+ *     the list and one reference dropped. This function takes the list
+ *     lock and is atomic with respect to other list locking functions.
+ */
+void skb_queue_purge(struct sk_buff_head *list)
+{
+       struct sk_buff *skb;
+       while ((skb = skb_dequeue(list)) != NULL)
+               kfree_skb(skb);
+}
+EXPORT_SYMBOL(skb_queue_purge);
+
+/**
+ *     skb_queue_head - queue a buffer at the list head
+ *     @list: list to use
+ *     @newsk: buffer to queue
+ *
+ *     Queue a buffer at the start of the list. This function takes the
+ *     list lock and can be used safely with other locking &sk_buff functions
+ *     safely.
+ *
+ *     A buffer cannot be placed on two lists at the same time.
+ */
+void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->lock, flags);
+       __skb_queue_head(list, newsk);
+       spin_unlock_irqrestore(&list->lock, flags);
+}
+EXPORT_SYMBOL(skb_queue_head);
+
+/**
+ *     skb_queue_tail - queue a buffer at the list tail
+ *     @list: list to use
+ *     @newsk: buffer to queue
+ *
+ *     Queue a buffer at the tail of the list. This function takes the
+ *     list lock and can be used safely with other locking &sk_buff functions
+ *     safely.
+ *
+ *     A buffer cannot be placed on two lists at the same time.
+ */
+void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->lock, flags);
+       __skb_queue_tail(list, newsk);
+       spin_unlock_irqrestore(&list->lock, flags);
+}
+EXPORT_SYMBOL(skb_queue_tail);
+
+/**
+ *     skb_unlink      -       remove a buffer from a list
+ *     @skb: buffer to remove
+ *     @list: list to use
+ *
+ *     Remove a packet from a list. The list locks are taken and this
+ *     function is atomic with respect to other list locked calls
+ *
+ *     You must know what list the SKB is on.
+ */
+void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->lock, flags);
+       __skb_unlink(skb, list);
+       spin_unlock_irqrestore(&list->lock, flags);
+}
+EXPORT_SYMBOL(skb_unlink);
+
+/**
+ *     skb_append      -       append a buffer
+ *     @old: buffer to insert after
+ *     @newsk: buffer to insert
+ *     @list: list to use
+ *
+ *     Place a packet after a given packet in a list. The list locks are taken
+ *     and this function is atomic with respect to other list locked calls.
+ *     A buffer cannot be placed on two lists at the same time.
+ */
+void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->lock, flags);
+       __skb_queue_after(list, old, newsk);
+       spin_unlock_irqrestore(&list->lock, flags);
+}
+EXPORT_SYMBOL(skb_append);
+
+/**
+ *     skb_insert      -       insert a buffer
+ *     @old: buffer to insert before
+ *     @newsk: buffer to insert
+ *     @list: list to use
+ *
+ *     Place a packet before a given packet in a list. The list locks are
+ *     taken and this function is atomic with respect to other list locked
+ *     calls.
+ *
+ *     A buffer cannot be placed on two lists at the same time.
+ */
+void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->lock, flags);
+       __skb_insert(newsk, old->prev, old, list);
+       spin_unlock_irqrestore(&list->lock, flags);
+}
+EXPORT_SYMBOL(skb_insert);
+
+static inline void skb_split_inside_header(struct sk_buff *skb,
+                                          struct sk_buff* skb1,
+                                          const u32 len, const int pos)
+{
+       int i;
+
+       skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - len),
+                                        pos - len);
+       /* And move data appendix as is. */
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+               skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
+
+       skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
+       skb_shinfo(skb)->nr_frags  = 0;
+       skb1->data_len             = skb->data_len;
+       skb1->len                  += skb1->data_len;
+       skb->data_len              = 0;
+       skb->len                   = len;
+       skb_set_tail_pointer(skb, len);
+}
+
+static inline void skb_split_no_header(struct sk_buff *skb,
+                                      struct sk_buff* skb1,
+                                      const u32 len, int pos)
+{
+       int i, k = 0;
+       const int nfrags = skb_shinfo(skb)->nr_frags;
+
+       skb_shinfo(skb)->nr_frags = 0;
+       skb1->len                 = skb1->data_len = skb->len - len;
+       skb->len                  = len;
+       skb->data_len             = len - pos;
+
+       for (i = 0; i < nfrags; i++) {
+               int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+
+               if (pos + size > len) {
+                       skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i];
+
+                       if (pos < len) {
+                               /* Split frag.
+                                * We have two variants in this case:
+                                * 1. Move all the frag to the second
+                                *    part, if it is possible. F.e.
+                                *    this approach is mandatory for TUX,
+                                *    where splitting is expensive.
+                                * 2. Split is accurately. We make this.
+                                */
+                               skb_frag_ref(skb, i);
+                               skb_shinfo(skb1)->frags[0].page_offset += len - pos;
+                               skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos);
+                               skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos);
+                               skb_shinfo(skb)->nr_frags++;
+                       }
+                       k++;
+               } else
+                       skb_shinfo(skb)->nr_frags++;
+               pos += size;
+       }
+       skb_shinfo(skb1)->nr_frags = k;
+}
+
+/**
+ * skb_split - Split fragmented skb to two parts at length len.
+ * @skb: the buffer to split
+ * @skb1: the buffer to receive the second part
+ * @len: new length for skb
+ */
+void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
+{
+       int pos = skb_headlen(skb);
+
+       skb_shinfo(skb1)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+       if (len < pos)  /* Split line is inside header. */
+               skb_split_inside_header(skb, skb1, len, pos);
+       else            /* Second chunk has no header, nothing to copy. */
+               skb_split_no_header(skb, skb1, len, pos);
+}
+EXPORT_SYMBOL(skb_split);
+
+/* Shifting from/to a cloned skb is a no-go.
+ *
+ * Caller cannot keep skb_shinfo related pointers past calling here!
+ */
+static int skb_prepare_for_shift(struct sk_buff *skb)
+{
+       return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+}
+
+/**
+ * skb_shift - Shifts paged data partially from skb to another
+ * @tgt: buffer into which tail data gets added
+ * @skb: buffer from which the paged data comes from
+ * @shiftlen: shift up to this many bytes
+ *
+ * Attempts to shift up to shiftlen worth of bytes, which may be less than
+ * the length of the skb, from skb to tgt. Returns number bytes shifted.
+ * It's up to caller to free skb if everything was shifted.
+ *
+ * If @tgt runs out of frags, the whole operation is aborted.
+ *
+ * Skb cannot include anything else but paged data while tgt is allowed
+ * to have non-paged data as well.
+ *
+ * TODO: full sized shift could be optimized but that would need
+ * specialized skb free'er to handle frags without up-to-date nr_frags.
+ */
+int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
+{
+       int from, to, merge, todo;
+       struct skb_frag_struct *fragfrom, *fragto;
+
+       BUG_ON(shiftlen > skb->len);
+       BUG_ON(skb_headlen(skb));       /* Would corrupt stream */
+
+       todo = shiftlen;
+       from = 0;
+       to = skb_shinfo(tgt)->nr_frags;
+       fragfrom = &skb_shinfo(skb)->frags[from];
+
+       /* Actual merge is delayed until the point when we know we can
+        * commit all, so that we don't have to undo partial changes
+        */
+       if (!to ||
+           !skb_can_coalesce(tgt, to, skb_frag_page(fragfrom),
+                             fragfrom->page_offset)) {
+               merge = -1;
+       } else {
+               merge = to - 1;
+
+               todo -= skb_frag_size(fragfrom);
+               if (todo < 0) {
+                       if (skb_prepare_for_shift(skb) ||
+                           skb_prepare_for_shift(tgt))
+                               return 0;
+
+                       /* All previous frag pointers might be stale! */
+                       fragfrom = &skb_shinfo(skb)->frags[from];
+                       fragto = &skb_shinfo(tgt)->frags[merge];
+
+                       skb_frag_size_add(fragto, shiftlen);
+                       skb_frag_size_sub(fragfrom, shiftlen);
+                       fragfrom->page_offset += shiftlen;
+
+                       goto onlymerged;
+               }
+
+               from++;
+       }
+
+       /* Skip full, not-fitting skb to avoid expensive operations */
+       if ((shiftlen == skb->len) &&
+           (skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to))
+               return 0;
+
+       if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt))
+               return 0;
+
+       while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) {
+               if (to == MAX_SKB_FRAGS)
+                       return 0;
+
+               fragfrom = &skb_shinfo(skb)->frags[from];
+               fragto = &skb_shinfo(tgt)->frags[to];
+
+               if (todo >= skb_frag_size(fragfrom)) {
+                       *fragto = *fragfrom;
+                       todo -= skb_frag_size(fragfrom);
+                       from++;
+                       to++;
+
+               } else {
+                       __skb_frag_ref(fragfrom);
+                       fragto->page = fragfrom->page;
+                       fragto->page_offset = fragfrom->page_offset;
+                       skb_frag_size_set(fragto, todo);
+
+                       fragfrom->page_offset += todo;
+                       skb_frag_size_sub(fragfrom, todo);
+                       todo = 0;
+
+                       to++;
+                       break;
+               }
+       }
+
+       /* Ready to "commit" this state change to tgt */
+       skb_shinfo(tgt)->nr_frags = to;
+
+       if (merge >= 0) {
+               fragfrom = &skb_shinfo(skb)->frags[0];
+               fragto = &skb_shinfo(tgt)->frags[merge];
+
+               skb_frag_size_add(fragto, skb_frag_size(fragfrom));
+               __skb_frag_unref(fragfrom);
+       }
+
+       /* Reposition in the original skb */
+       to = 0;
+       while (from < skb_shinfo(skb)->nr_frags)
+               skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++];
+       skb_shinfo(skb)->nr_frags = to;
+
+       BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags);
+
+onlymerged:
+       /* Most likely the tgt won't ever need its checksum anymore, skb on
+        * the other hand might need it if it needs to be resent
+        */
+       tgt->ip_summed = CHECKSUM_PARTIAL;
+       skb->ip_summed = CHECKSUM_PARTIAL;
+
+       /* Yak, is it really working this way? Some helper please? */
+       skb->len -= shiftlen;
+       skb->data_len -= shiftlen;
+       skb->truesize -= shiftlen;
+       tgt->len += shiftlen;
+       tgt->data_len += shiftlen;
+       tgt->truesize += shiftlen;
+
+       return shiftlen;
+}
+
+/**
+ * skb_prepare_seq_read - Prepare a sequential read of skb data
+ * @skb: the buffer to read
+ * @from: lower offset of data to be read
+ * @to: upper offset of data to be read
+ * @st: state variable
+ *
+ * Initializes the specified state variable. Must be called before
+ * invoking skb_seq_read() for the first time.
+ */
+void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
+                         unsigned int to, struct skb_seq_state *st)
+{
+       st->lower_offset = from;
+       st->upper_offset = to;
+       st->root_skb = st->cur_skb = skb;
+       st->frag_idx = st->stepped_offset = 0;
+       st->frag_data = NULL;
+}
+EXPORT_SYMBOL(skb_prepare_seq_read);
+
+/**
+ * skb_seq_read - Sequentially read skb data
+ * @consumed: number of bytes consumed by the caller so far
+ * @data: destination pointer for data to be returned
+ * @st: state variable
+ *
+ * Reads a block of skb data at &consumed relative to the
+ * lower offset specified to skb_prepare_seq_read(). Assigns
+ * the head of the data block to &data and returns the length
+ * of the block or 0 if the end of the skb data or the upper
+ * offset has been reached.
+ *
+ * The caller is not required to consume all of the data
+ * returned, i.e. &consumed is typically set to the number
+ * of bytes already consumed and the next call to
+ * skb_seq_read() will return the remaining part of the block.
+ *
+ * Note 1: The size of each block of data returned can be arbitrary,
+ *       this limitation is the cost for zerocopy seqeuental
+ *       reads of potentially non linear data.
+ *
+ * Note 2: Fragment lists within fragments are not implemented
+ *       at the moment, state->root_skb could be replaced with
+ *       a stack for this purpose.
+ */
+unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
+                         struct skb_seq_state *st)
+{
+       unsigned int block_limit, abs_offset = consumed + st->lower_offset;
+       skb_frag_t *frag;
+
+       if (unlikely(abs_offset >= st->upper_offset))
+               return 0;
+
+next_skb:
+       block_limit = skb_headlen(st->cur_skb) + st->stepped_offset;
+
+       if (abs_offset < block_limit && !st->frag_data) {
+               *data = st->cur_skb->data + (abs_offset - st->stepped_offset);
+               return block_limit - abs_offset;
+       }
+
+       if (st->frag_idx == 0 && !st->frag_data)
+               st->stepped_offset += skb_headlen(st->cur_skb);
+
+       while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) {
+               frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx];
+               block_limit = skb_frag_size(frag) + st->stepped_offset;
+
+               if (abs_offset < block_limit) {
+                       if (!st->frag_data)
+                               st->frag_data = kmap_atomic(skb_frag_page(frag));
+
+                       *data = (u8 *) st->frag_data + frag->page_offset +
+                               (abs_offset - st->stepped_offset);
+
+                       return block_limit - abs_offset;
+               }
+
+               if (st->frag_data) {
+                       kunmap_atomic(st->frag_data);
+                       st->frag_data = NULL;
+               }
+
+               st->frag_idx++;
+               st->stepped_offset += skb_frag_size(frag);
+       }
+
+       if (st->frag_data) {
+               kunmap_atomic(st->frag_data);
+               st->frag_data = NULL;
+       }
+
+       if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) {
+               st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
+               st->frag_idx = 0;
+               goto next_skb;
+       } else if (st->cur_skb->next) {
+               st->cur_skb = st->cur_skb->next;
+               st->frag_idx = 0;
+               goto next_skb;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(skb_seq_read);
+
+/**
+ * skb_abort_seq_read - Abort a sequential read of skb data
+ * @st: state variable
+ *
+ * Must be called if skb_seq_read() was not called until it
+ * returned 0.
+ */
+void skb_abort_seq_read(struct skb_seq_state *st)
+{
+       if (st->frag_data)
+               kunmap_atomic(st->frag_data);
+}
+EXPORT_SYMBOL(skb_abort_seq_read);
+
+#define TS_SKB_CB(state)       ((struct skb_seq_state *) &((state)->cb))
+
+static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text,
+                                         struct ts_config *conf,
+                                         struct ts_state *state)
+{
+       return skb_seq_read(offset, text, TS_SKB_CB(state));
+}
+
+static void skb_ts_finish(struct ts_config *conf, struct ts_state *state)
+{
+       skb_abort_seq_read(TS_SKB_CB(state));
+}
+
+/**
+ * skb_find_text - Find a text pattern in skb data
+ * @skb: the buffer to look in
+ * @from: search offset
+ * @to: search limit
+ * @config: textsearch configuration
+ * @state: uninitialized textsearch state variable
+ *
+ * Finds a pattern in the skb data according to the specified
+ * textsearch configuration. Use textsearch_next() to retrieve
+ * subsequent occurrences of the pattern. Returns the offset
+ * to the first occurrence or UINT_MAX if no match was found.
+ */
+unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
+                          unsigned int to, struct ts_config *config,
+                          struct ts_state *state)
+{
+       unsigned int ret;
+
+       config->get_next_block = skb_ts_get_next_block;
+       config->finish = skb_ts_finish;
+
+       skb_prepare_seq_read(skb, from, to, TS_SKB_CB(state));
+
+       ret = textsearch_find(config, state);
+       return (ret <= to - from ? ret : UINT_MAX);
+}
+EXPORT_SYMBOL(skb_find_text);
+
+/**
+ * skb_append_datato_frags - append the user data to a skb
+ * @sk: sock  structure
+ * @skb: skb structure to be appened with user data.
+ * @getfrag: call back function to be used for getting the user data
+ * @from: pointer to user message iov
+ * @length: length of the iov message
+ *
+ * Description: This procedure append the user data in the fragment part
+ * of the skb if any page alloc fails user this procedure returns  -ENOMEM
+ */
+int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
+                       int (*getfrag)(void *from, char *to, int offset,
+                                       int len, int odd, struct sk_buff *skb),
+                       void *from, int length)
+{
+       int frg_cnt = skb_shinfo(skb)->nr_frags;
+       int copy;
+       int offset = 0;
+       int ret;
+       struct page_frag *pfrag = &current->task_frag;
+
+       do {
+               /* Return error if we don't have space for new frag */
+               if (frg_cnt >= MAX_SKB_FRAGS)
+                       return -EMSGSIZE;
+
+               if (!sk_page_frag_refill(sk, pfrag))
+                       return -ENOMEM;
+
+               /* copy the user data to page */
+               copy = min_t(int, length, pfrag->size - pfrag->offset);
+
+               ret = getfrag(from, page_address(pfrag->page) + pfrag->offset,
+                             offset, copy, 0, skb);
+               if (ret < 0)
+                       return -EFAULT;
+
+               /* copy was successful so update the size parameters */
+               skb_fill_page_desc(skb, frg_cnt, pfrag->page, pfrag->offset,
+                                  copy);
+               frg_cnt++;
+               pfrag->offset += copy;
+               get_page(pfrag->page);
+
+               skb->truesize += copy;
+               atomic_add(copy, &sk->sk_wmem_alloc);
+               skb->len += copy;
+               skb->data_len += copy;
+               offset += copy;
+               length -= copy;
+
+       } while (length > 0);
+
+       return 0;
+}
+EXPORT_SYMBOL(skb_append_datato_frags);
+
+/**
+ *     skb_pull_rcsum - pull skb and update receive checksum
+ *     @skb: buffer to update
+ *     @len: length of data pulled
+ *
+ *     This function performs an skb_pull on the packet and updates
+ *     the CHECKSUM_COMPLETE checksum.  It should be used on
+ *     receive path processing instead of skb_pull unless you know
+ *     that the checksum difference is zero (e.g., a valid IP header)
+ *     or you are setting ip_summed to CHECKSUM_NONE.
+ */
+unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len)
+{
+       BUG_ON(len > skb->len);
+       skb->len -= len;
+       BUG_ON(skb->len < skb->data_len);
+       skb_postpull_rcsum(skb, skb->data, len);
+       return skb->data += len;
+}
+EXPORT_SYMBOL_GPL(skb_pull_rcsum);
+
+/**
+ *     skb_segment - Perform protocol segmentation on skb.
+ *     @skb: buffer to segment
+ *     @features: features for the output path (see dev->features)
+ *
+ *     This function performs segmentation on the given skb.  It returns
+ *     a pointer to the first in a list of new skbs for the segments.
+ *     In case of error it returns ERR_PTR(err).
+ */
+struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
+{
+       struct sk_buff *segs = NULL;
+       struct sk_buff *tail = NULL;
+       struct sk_buff *fskb = skb_shinfo(skb)->frag_list;
+       unsigned int mss = skb_shinfo(skb)->gso_size;
+       unsigned int doffset = skb->data - skb_mac_header(skb);
+       unsigned int offset = doffset;
+       unsigned int tnl_hlen = skb_tnl_header_len(skb);
+       unsigned int headroom;
+       unsigned int len;
+       __be16 proto;
+       bool csum;
+       int sg = !!(features & NETIF_F_SG);
+       int nfrags = skb_shinfo(skb)->nr_frags;
+       int err = -ENOMEM;
+       int i = 0;
+       int pos;
+
+       proto = skb_network_protocol(skb);
+       if (unlikely(!proto))
+               return ERR_PTR(-EINVAL);
+
+       csum = !!can_checksum_protocol(features, proto);
+       __skb_push(skb, doffset);
+       headroom = skb_headroom(skb);
+       pos = skb_headlen(skb);
+
+       do {
+               struct sk_buff *nskb;
+               skb_frag_t *frag;
+               int hsize;
+               int size;
+
+               len = skb->len - offset;
+               if (len > mss)
+                       len = mss;
+
+               hsize = skb_headlen(skb) - offset;
+               if (hsize < 0)
+                       hsize = 0;
+               if (hsize > len || !sg)
+                       hsize = len;
+
+               if (!hsize && i >= nfrags) {
+                       BUG_ON(fskb->len != len);
+
+                       pos += len;
+                       nskb = skb_clone(fskb, GFP_ATOMIC);
+                       fskb = fskb->next;
+
+                       if (unlikely(!nskb))
+                               goto err;
+
+                       hsize = skb_end_offset(nskb);
+                       if (skb_cow_head(nskb, doffset + headroom)) {
+                               kfree_skb(nskb);
+                               goto err;
+                       }
+
+                       nskb->truesize += skb_end_offset(nskb) - hsize;
+                       skb_release_head_state(nskb);
+                       __skb_push(nskb, doffset);
+               } else {
+                       nskb = __alloc_skb(hsize + doffset + headroom,
+                                          GFP_ATOMIC, skb_alloc_rx_flag(skb),
+                                          NUMA_NO_NODE);
+
+                       if (unlikely(!nskb))
+                               goto err;
+
+                       skb_reserve(nskb, headroom);
+                       __skb_put(nskb, doffset);
+               }
+
+               if (segs)
+                       tail->next = nskb;
+               else
+                       segs = nskb;
+               tail = nskb;
+
+               __copy_skb_header(nskb, skb);
+               nskb->mac_len = skb->mac_len;
+
+               /* nskb and skb might have different headroom */
+               if (nskb->ip_summed == CHECKSUM_PARTIAL)
+                       nskb->csum_start += skb_headroom(nskb) - headroom;
+
+               skb_reset_mac_header(nskb);
+               skb_set_network_header(nskb, skb->mac_len);
+               nskb->transport_header = (nskb->network_header +
+                                         skb_network_header_len(skb));
+
+               skb_copy_from_linear_data_offset(skb, -tnl_hlen,
+                                                nskb->data - tnl_hlen,
+                                                doffset + tnl_hlen);
+
+               if (fskb != skb_shinfo(skb)->frag_list)
+                       goto perform_csum_check;
+
+               if (!sg) {
+                       nskb->ip_summed = CHECKSUM_NONE;
+                       nskb->csum = skb_copy_and_csum_bits(skb, offset,
+                                                           skb_put(nskb, len),
+                                                           len, 0);
+                       continue;
+               }
+
+               frag = skb_shinfo(nskb)->frags;
+
+               skb_copy_from_linear_data_offset(skb, offset,
+                                                skb_put(nskb, hsize), hsize);
+
+               skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+
+               while (pos < offset + len && i < nfrags) {
+                       *frag = skb_shinfo(skb)->frags[i];
+                       __skb_frag_ref(frag);
+                       size = skb_frag_size(frag);
+
+                       if (pos < offset) {
+                               frag->page_offset += offset - pos;
+                               skb_frag_size_sub(frag, offset - pos);
+                       }
+
+                       skb_shinfo(nskb)->nr_frags++;
+
+                       if (pos + size <= offset + len) {
+                               i++;
+                               pos += size;
+                       } else {
+                               skb_frag_size_sub(frag, pos + size - (offset + len));
+                               goto skip_fraglist;
+                       }
+
+                       frag++;
+               }
+
+               if (pos < offset + len) {
+                       struct sk_buff *fskb2 = fskb;
+
+                       BUG_ON(pos + fskb->len != offset + len);
+
+                       pos += fskb->len;
+                       fskb = fskb->next;
+
+                       if (fskb2->next) {
+                               fskb2 = skb_clone(fskb2, GFP_ATOMIC);
+                               if (!fskb2)
+                                       goto err;
+                       } else
+                               skb_get(fskb2);
+
+                       SKB_FRAG_ASSERT(nskb);
+                       skb_shinfo(nskb)->frag_list = fskb2;
+               }
+
+skip_fraglist:
+               nskb->data_len = len - hsize;
+               nskb->len += nskb->data_len;
+               nskb->truesize += nskb->data_len;
+
+perform_csum_check:
+               if (!csum) {
+                       nskb->csum = skb_checksum(nskb, doffset,
+                                                 nskb->len - doffset, 0);
+                       nskb->ip_summed = CHECKSUM_NONE;
+               }
+       } while ((offset += len) < skb->len);
+
+       return segs;
+
+err:
+       while ((skb = segs)) {
+               segs = skb->next;
+               kfree_skb(skb);
+       }
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(skb_segment);
+
+int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+{
+       struct sk_buff *p = *head;
+       struct sk_buff *nskb;
+       struct skb_shared_info *skbinfo = skb_shinfo(skb);
+       struct skb_shared_info *pinfo = skb_shinfo(p);
+       unsigned int headroom;
+       unsigned int len = skb_gro_len(skb);
+       unsigned int offset = skb_gro_offset(skb);
+       unsigned int headlen = skb_headlen(skb);
+       unsigned int delta_truesize;
+
+       if (p->len + len >= 65536)
+               return -E2BIG;
+
+       if (pinfo->frag_list)
+               goto merge;
+       else if (headlen <= offset) {
+               skb_frag_t *frag;
+               skb_frag_t *frag2;
+               int i = skbinfo->nr_frags;
+               int nr_frags = pinfo->nr_frags + i;
+
+               offset -= headlen;
+
+               if (nr_frags > MAX_SKB_FRAGS)
+                       return -E2BIG;
+
+               pinfo->nr_frags = nr_frags;
+               skbinfo->nr_frags = 0;
+
+               frag = pinfo->frags + nr_frags;
+               frag2 = skbinfo->frags + i;
+               do {
+                       *--frag = *--frag2;
+               } while (--i);
+
+               frag->page_offset += offset;
+               skb_frag_size_sub(frag, offset);
+
+               /* all fragments truesize : remove (head size + sk_buff) */
+               delta_truesize = skb->truesize -
+                                SKB_TRUESIZE(skb_end_offset(skb));
+
+               skb->truesize -= skb->data_len;
+               skb->len -= skb->data_len;
+               skb->data_len = 0;
+
+               NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE;
+               goto done;
+       } else if (skb->head_frag) {
+               int nr_frags = pinfo->nr_frags;
+               skb_frag_t *frag = pinfo->frags + nr_frags;
+               struct page *page = virt_to_head_page(skb->head);
+               unsigned int first_size = headlen - offset;
+               unsigned int first_offset;
+
+               if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS)
+                       return -E2BIG;
+
+               first_offset = skb->data -
+                              (unsigned char *)page_address(page) +
+                              offset;
+
+               pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
+
+               frag->page.p      = page;
+               frag->page_offset = first_offset;
+               skb_frag_size_set(frag, first_size);
+
+               memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
+               /* We dont need to clear skbinfo->nr_frags here */
+
+               delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
+               NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
+               goto done;
+       } else if (skb_gro_len(p) != pinfo->gso_size)
+               return -E2BIG;
+
+       headroom = skb_headroom(p);
+       nskb = alloc_skb(headroom + skb_gro_offset(p), GFP_ATOMIC);
+       if (unlikely(!nskb))
+               return -ENOMEM;
+
+       __copy_skb_header(nskb, p);
+       nskb->mac_len = p->mac_len;
+
+       skb_reserve(nskb, headroom);
+       __skb_put(nskb, skb_gro_offset(p));
+
+       skb_set_mac_header(nskb, skb_mac_header(p) - p->data);
+       skb_set_network_header(nskb, skb_network_offset(p));
+       skb_set_transport_header(nskb, skb_transport_offset(p));
+
+       __skb_pull(p, skb_gro_offset(p));
+       memcpy(skb_mac_header(nskb), skb_mac_header(p),
+              p->data - skb_mac_header(p));
+
+       skb_shinfo(nskb)->frag_list = p;
+       skb_shinfo(nskb)->gso_size = pinfo->gso_size;
+       pinfo->gso_size = 0;
+       skb_header_release(p);
+       NAPI_GRO_CB(nskb)->last = p;
+
+       nskb->data_len += p->len;
+       nskb->truesize += p->truesize;
+       nskb->len += p->len;
+
+       *head = nskb;
+       nskb->next = p->next;
+       p->next = NULL;
+
+       p = nskb;
+
+merge:
+       delta_truesize = skb->truesize;
+       if (offset > headlen) {
+               unsigned int eat = offset - headlen;
+
+               skbinfo->frags[0].page_offset += eat;
+               skb_frag_size_sub(&skbinfo->frags[0], eat);
+               skb->data_len -= eat;
+               skb->len -= eat;
+               offset = headlen;
+       }
+
+       __skb_pull(skb, offset);
+
+       NAPI_GRO_CB(p)->last->next = skb;
+       NAPI_GRO_CB(p)->last = skb;
+       skb_header_release(skb);
+
+done:
+       NAPI_GRO_CB(p)->count++;
+       p->data_len += len;
+       p->truesize += delta_truesize;
+       p->len += len;
+
+       NAPI_GRO_CB(skb)->same_flow = 1;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(skb_gro_receive);
+
+void __init skb_init(void)
+{
+       skbuff_head_cache = kmem_cache_create("skbuff_head_cache",
+                                             sizeof(struct sk_buff),
+                                             0,
+                                             SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+                                             NULL);
+       skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache",
+                                               (2*sizeof(struct sk_buff)) +
+                                               sizeof(atomic_t),
+                                               0,
+                                               SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+                                               NULL);
+}
+
+/**
+ *     skb_to_sgvec - Fill a scatter-gather list from a socket buffer
+ *     @skb: Socket buffer containing the buffers to be mapped
+ *     @sg: The scatter-gather list to map into
+ *     @offset: The offset into the buffer's contents to start mapping
+ *     @len: Length of buffer space to be mapped
+ *
+ *     Fill the specified scatter-gather list with mappings/pointers into a
+ *     region of the buffer space attached to a socket buffer.
+ */
+static int
+__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
+{
+       int start = skb_headlen(skb);
+       int i, copy = start - offset;
+       struct sk_buff *frag_iter;
+       int elt = 0;
+
+       if (copy > 0) {
+               if (copy > len)
+                       copy = len;
+               sg_set_buf(sg, skb->data + offset, copy);
+               elt++;
+               if ((len -= copy) == 0)
+                       return elt;
+               offset += copy;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]);
+               if ((copy = end - offset) > 0) {
+                       skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+                       if (copy > len)
+                               copy = len;
+                       sg_set_page(&sg[elt], skb_frag_page(frag), copy,
+                                       frag->page_offset+offset-start);
+                       elt++;
+                       if (!(len -= copy))
+                               return elt;
+                       offset += copy;
+               }
+               start = end;
+       }
+
+       skb_walk_frags(skb, frag_iter) {
+               int end;
+
+               WARN_ON(start > offset + len);
+
+               end = start + frag_iter->len;
+               if ((copy = end - offset) > 0) {
+                       if (copy > len)
+                               copy = len;
+                       elt += __skb_to_sgvec(frag_iter, sg+elt, offset - start,
+                                             copy);
+                       if ((len -= copy) == 0)
+                               return elt;
+                       offset += copy;
+               }
+               start = end;
+       }
+       BUG_ON(len);
+       return elt;
+}
+
+int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
+{
+       int nsg = __skb_to_sgvec(skb, sg, offset, len);
+
+       sg_mark_end(&sg[nsg - 1]);
+
+       return nsg;
+}
+EXPORT_SYMBOL_GPL(skb_to_sgvec);
+
+/**
+ *     skb_cow_data - Check that a socket buffer's data buffers are writable
+ *     @skb: The socket buffer to check.
+ *     @tailbits: Amount of trailing space to be added
+ *     @trailer: Returned pointer to the skb where the @tailbits space begins
+ *
+ *     Make sure that the data buffers attached to a socket buffer are
+ *     writable. If they are not, private copies are made of the data buffers
+ *     and the socket buffer is set to use these instead.
+ *
+ *     If @tailbits is given, make sure that there is space to write @tailbits
+ *     bytes of data beyond current end of socket buffer.  @trailer will be
+ *     set to point to the skb in which this space begins.
+ *
+ *     The number of scatterlist elements required to completely map the
+ *     COW'd and extended socket buffer will be returned.
+ */
+int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
+{
+       int copyflag;
+       int elt;
+       struct sk_buff *skb1, **skb_p;
+
+       /* If skb is cloned or its head is paged, reallocate
+        * head pulling out all the pages (pages are considered not writable
+        * at the moment even if they are anonymous).
+        */
+       if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
+           __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
+               return -ENOMEM;
+
+       /* Easy case. Most of packets will go this way. */
+       if (!skb_has_frag_list(skb)) {
+               /* A little of trouble, not enough of space for trailer.
+                * This should not happen, when stack is tuned to generate
+                * good frames. OK, on miss we reallocate and reserve even more
+                * space, 128 bytes is fair. */
+
+               if (skb_tailroom(skb) < tailbits &&
+                   pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC))
+                       return -ENOMEM;
+
+               /* Voila! */
+               *trailer = skb;
+               return 1;
+       }
+
+       /* Misery. We are in troubles, going to mincer fragments... */
+
+       elt = 1;
+       skb_p = &skb_shinfo(skb)->frag_list;
+       copyflag = 0;
+
+       while ((skb1 = *skb_p) != NULL) {
+               int ntail = 0;
+
+               /* The fragment is partially pulled by someone,
+                * this can happen on input. Copy it and everything
+                * after it. */
+
+               if (skb_shared(skb1))
+                       copyflag = 1;
+
+               /* If the skb is the last, worry about trailer. */
+
+               if (skb1->next == NULL && tailbits) {
+                       if (skb_shinfo(skb1)->nr_frags ||
+                           skb_has_frag_list(skb1) ||
+                           skb_tailroom(skb1) < tailbits)
+                               ntail = tailbits + 128;
+               }
+
+               if (copyflag ||
+                   skb_cloned(skb1) ||
+                   ntail ||
+                   skb_shinfo(skb1)->nr_frags ||
+                   skb_has_frag_list(skb1)) {
+                       struct sk_buff *skb2;
+
+                       /* Fuck, we are miserable poor guys... */
+                       if (ntail == 0)
+                               skb2 = skb_copy(skb1, GFP_ATOMIC);
+                       else
+                               skb2 = skb_copy_expand(skb1,
+                                                      skb_headroom(skb1),
+                                                      ntail,
+                                                      GFP_ATOMIC);
+                       if (unlikely(skb2 == NULL))
+                               return -ENOMEM;
+
+                       if (skb1->sk)
+                               skb_set_owner_w(skb2, skb1->sk);
+
+                       /* Looking around. Are we still alive?
+                        * OK, link new skb, drop old one */
+
+                       skb2->next = skb1->next;
+                       *skb_p = skb2;
+                       kfree_skb(skb1);
+                       skb1 = skb2;
+               }
+               elt++;
+               *trailer = skb1;
+               skb_p = &skb1->next;
+       }
+
+       return elt;
+}
+EXPORT_SYMBOL_GPL(skb_cow_data);
+
+static void sock_rmem_free(struct sk_buff *skb)
+{
+       struct sock *sk = skb->sk;
+
+       atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
+}
+
+/*
+ * Note: We dont mem charge error packets (no sk_forward_alloc changes)
+ */
+int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
+{
+       int len = skb->len;
+
+       if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+           (unsigned int)sk->sk_rcvbuf)
+               return -ENOMEM;
+
+       skb_orphan(skb);
+       skb->sk = sk;
+       skb->destructor = sock_rmem_free;
+       atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+
+       /* before exiting rcu section, make sure dst is refcounted */
+       skb_dst_force(skb);
+
+       skb_queue_tail(&sk->sk_error_queue, skb);
+       if (!sock_flag(sk, SOCK_DEAD))
+               sk->sk_data_ready(sk, len);
+       return 0;
+}
+EXPORT_SYMBOL(sock_queue_err_skb);
+
+void skb_tstamp_tx(struct sk_buff *orig_skb,
+               struct skb_shared_hwtstamps *hwtstamps)
+{
+       struct sock *sk = orig_skb->sk;
+       struct sock_exterr_skb *serr;
+       struct sk_buff *skb;
+       int err;
+
+       if (!sk)
+               return;
+
+       if (hwtstamps) {
+               *skb_hwtstamps(orig_skb) =
+                       *hwtstamps;
+       } else {
+               /*
+                * no hardware time stamps available,
+                * so keep the shared tx_flags and only
+                * store software time stamp
+                */
+               orig_skb->tstamp = ktime_get_real();
+       }
+
+       skb = skb_clone(orig_skb, GFP_ATOMIC);
+       if (!skb)
+               return;
+
+       serr = SKB_EXT_ERR(skb);
+       memset(serr, 0, sizeof(*serr));
+       serr->ee.ee_errno = ENOMSG;
+       serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
+
+       err = sock_queue_err_skb(sk, skb);
+
+       if (err)
+               kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(skb_tstamp_tx);
+
+void skb_complete_wifi_ack(struct sk_buff *skb, bool acked)
+{
+       struct sock *sk = skb->sk;
+       struct sock_exterr_skb *serr;
+       int err;
+
+       skb->wifi_acked_valid = 1;
+       skb->wifi_acked = acked;
+
+       serr = SKB_EXT_ERR(skb);
+       memset(serr, 0, sizeof(*serr));
+       serr->ee.ee_errno = ENOMSG;
+       serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS;
+
+       err = sock_queue_err_skb(sk, skb);
+       if (err)
+               kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(skb_complete_wifi_ack);
+
+
+/**
+ * skb_partial_csum_set - set up and verify partial csum values for packet
+ * @skb: the skb to set
+ * @start: the number of bytes after skb->data to start checksumming.
+ * @off: the offset from start to place the checksum.
+ *
+ * For untrusted partially-checksummed packets, we need to make sure the values
+ * for skb->csum_start and skb->csum_offset are valid so we don't oops.
+ *
+ * This function checks and sets those values and skb->ip_summed: if this
+ * returns false you should drop the packet.
+ */
+bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
+{
+       if (unlikely(start > skb_headlen(skb)) ||
+           unlikely((int)start + off > skb_headlen(skb) - 2)) {
+               net_warn_ratelimited("bad partial csum: csum=%u/%u len=%u\n",
+                                    start, off, skb_headlen(skb));
+               return false;
+       }
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       skb->csum_start = skb_headroom(skb) + start;
+       skb->csum_offset = off;
+       skb_set_transport_header(skb, start);
+       return true;
+}
+EXPORT_SYMBOL_GPL(skb_partial_csum_set);
+
+void __skb_warn_lro_forwarding(const struct sk_buff *skb)
+{
+       net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n",
+                            skb->dev->name);
+}
+EXPORT_SYMBOL(__skb_warn_lro_forwarding);
+
+void kfree_skb_partial(struct sk_buff *skb, bool head_stolen)
+{
+       if (head_stolen) {
+               skb_release_head_state(skb);
+               kmem_cache_free(skbuff_head_cache, skb);
+       } else {
+               __kfree_skb(skb);
+       }
+}
+EXPORT_SYMBOL(kfree_skb_partial);
+
+/**
+ * skb_try_coalesce - try to merge skb to prior one
+ * @to: prior buffer
+ * @from: buffer to add
+ * @fragstolen: pointer to boolean
+ * @delta_truesize: how much more was allocated than was requested
+ */
+bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
+                     bool *fragstolen, int *delta_truesize)
+{
+       int i, delta, len = from->len;
+
+       *fragstolen = false;
+
+       if (skb_cloned(to))
+               return false;
+
+       if (len <= skb_tailroom(to)) {
+               BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
+               *delta_truesize = 0;
+               return true;
+       }
+
+       if (skb_has_frag_list(to) || skb_has_frag_list(from))
+               return false;
+
+       if (skb_headlen(from) != 0) {
+               struct page *page;
+               unsigned int offset;
+
+               if (skb_shinfo(to)->nr_frags +
+                   skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS)
+                       return false;
+
+               if (skb_head_is_locked(from))
+                       return false;
+
+               delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
+
+               page = virt_to_head_page(from->head);
+               offset = from->data - (unsigned char *)page_address(page);
+
+               skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,
+                                  page, offset, skb_headlen(from));
+               *fragstolen = true;
+       } else {
+               if (skb_shinfo(to)->nr_frags +
+                   skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS)
+                       return false;
+
+               delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from));
+       }
+
+       WARN_ON_ONCE(delta < len);
+
+       memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags,
+              skb_shinfo(from)->frags,
+              skb_shinfo(from)->nr_frags * sizeof(skb_frag_t));
+       skb_shinfo(to)->nr_frags += skb_shinfo(from)->nr_frags;
+
+       if (!skb_cloned(from))
+               skb_shinfo(from)->nr_frags = 0;
+
+       /* if the skb is not cloned this does nothing
+        * since we set nr_frags to 0.
+        */
+       for (i = 0; i < skb_shinfo(from)->nr_frags; i++)
+               skb_frag_ref(from, i);
+
+       to->truesize += delta;
+       to->len += len;
+       to->data_len += len;
+
+       *delta_truesize = delta;
+       return true;
+}
+EXPORT_SYMBOL(skb_try_coalesce);
diff -ruN linux-3.10.27/net/ipv6/ip6_output.c linux-3.10.27-imq/net/ipv6/ip6_output.c
--- linux-3.10.27/net/ipv6/ip6_output.c 2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/ipv6/ip6_output.c     2014-01-18 10:19:59.348342972 +0100
@@ -89,9 +89,6 @@
        struct in6_addr *nexthop;
        int ret;
 
-       skb->protocol = htons(ETH_P_IPV6);
-       skb->dev = dev;
-
        if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
                struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
@@ -168,6 +165,13 @@
                return 0;
        }
 
+       /*
+        * IMQ-patch: moved setting skb->dev and skb->protocol from
+        * ip6_finish_output2 to fix crashing at netif_skb_features().
+        */
+       skb->protocol = htons(ETH_P_IPV6);
+       skb->dev = dev;
+
        return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
                            ip6_finish_output,
                            !(IP6CB(skb)->flags & IP6SKB_REROUTED));
diff -ruN linux-3.10.27/net/ipv6/ip6_output.c.orig linux-3.10.27-imq/net/ipv6/ip6_output.c.orig
--- linux-3.10.27/net/ipv6/ip6_output.c.orig    1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/net/ipv6/ip6_output.c.orig        2014-01-16 00:29:14.000000000 +0100
@@ -0,0 +1,1580 @@
+/*
+ *     IPv6 output functions
+ *     Linux INET6 implementation
+ *
+ *     Authors:
+ *     Pedro Roque             <roque@di.fc.ul.pt>
+ *
+ *     Based on linux/net/ipv4/ip_output.c
+ *
+ *     This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ *     Changes:
+ *     A.N.Kuznetsov   :       airthmetics in fragmentation.
+ *                             extension headers are implemented.
+ *                             route changes now work.
+ *                             ip6_forward does not confuse sniffers.
+ *                             etc.
+ *
+ *      H. von Brand    :       Added missing #include <linux/string.h>
+ *     Imran Patel     :       frag id should be in NBO
+ *      Kazunori MIYAZAWA @USAGI
+ *                     :       add ip6_append_data and related functions
+ *                             for datagram xmit
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/in6.h>
+#include <linux/tcp.h>
+#include <linux/route.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/ndisc.h>
+#include <net/protocol.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/rawv6.h>
+#include <net/icmp.h>
+#include <net/xfrm.h>
+#include <net/checksum.h>
+#include <linux/mroute6.h>
+
+int __ip6_local_out(struct sk_buff *skb)
+{
+       int len;
+
+       len = skb->len - sizeof(struct ipv6hdr);
+       if (len > IPV6_MAXPLEN)
+               len = 0;
+       ipv6_hdr(skb)->payload_len = htons(len);
+
+       return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
+                      skb_dst(skb)->dev, dst_output);
+}
+
+int ip6_local_out(struct sk_buff *skb)
+{
+       int err;
+
+       err = __ip6_local_out(skb);
+       if (likely(err == 1))
+               err = dst_output(skb);
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(ip6_local_out);
+
+static int ip6_finish_output2(struct sk_buff *skb)
+{
+       struct dst_entry *dst = skb_dst(skb);
+       struct net_device *dev = dst->dev;
+       struct neighbour *neigh;
+       struct in6_addr *nexthop;
+       int ret;
+
+       skb->protocol = htons(ETH_P_IPV6);
+       skb->dev = dev;
+
+       if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
+               struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+               if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
+                   ((mroute6_socket(dev_net(dev), skb) &&
+                    !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
+                    ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
+                                        &ipv6_hdr(skb)->saddr))) {
+                       struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+
+                       /* Do not check for IFF_ALLMULTI; multicast routing
+                          is not supported in any case.
+                        */
+                       if (newskb)
+                               NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
+                                       newskb, NULL, newskb->dev,
+                                       dev_loopback_xmit);
+
+                       if (ipv6_hdr(skb)->hop_limit == 0) {
+                               IP6_INC_STATS(dev_net(dev), idev,
+                                             IPSTATS_MIB_OUTDISCARDS);
+                               kfree_skb(skb);
+                               return 0;
+                       }
+               }
+
+               IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST,
+                               skb->len);
+
+               if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <=
+                   IPV6_ADDR_SCOPE_NODELOCAL &&
+                   !(dev->flags & IFF_LOOPBACK)) {
+                       kfree_skb(skb);
+                       return 0;
+               }
+       }
+
+       rcu_read_lock_bh();
+       nexthop = rt6_nexthop((struct rt6_info *)dst);
+       neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
+       if (unlikely(!neigh))
+               neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
+       if (!IS_ERR(neigh)) {
+               ret = dst_neigh_output(dst, neigh, skb);
+               rcu_read_unlock_bh();
+               return ret;
+       }
+       rcu_read_unlock_bh();
+
+       IP6_INC_STATS(dev_net(dst->dev),
+                     ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+       kfree_skb(skb);
+       return -EINVAL;
+}
+
+static int ip6_finish_output(struct sk_buff *skb)
+{
+       if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
+           dst_allfrag(skb_dst(skb)) ||
+           (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
+               return ip6_fragment(skb, ip6_finish_output2);
+       else
+               return ip6_finish_output2(skb);
+}
+
+int ip6_output(struct sk_buff *skb)
+{
+       struct net_device *dev = skb_dst(skb)->dev;
+       struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+       if (unlikely(idev->cnf.disable_ipv6)) {
+               IP6_INC_STATS(dev_net(dev), idev,
+                             IPSTATS_MIB_OUTDISCARDS);
+               kfree_skb(skb);
+               return 0;
+       }
+
+       return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
+                           ip6_finish_output,
+                           !(IP6CB(skb)->flags & IP6SKB_REROUTED));
+}
+
+/*
+ *     xmit an sk_buff (used by TCP, SCTP and DCCP)
+ */
+
+int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
+            struct ipv6_txoptions *opt, int tclass)
+{
+       struct net *net = sock_net(sk);
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct in6_addr *first_hop = &fl6->daddr;
+       struct dst_entry *dst = skb_dst(skb);
+       struct ipv6hdr *hdr;
+       u8  proto = fl6->flowi6_proto;
+       int seg_len = skb->len;
+       int hlimit = -1;
+       u32 mtu;
+
+       if (opt) {
+               unsigned int head_room;
+
+               /* First: exthdrs may take lots of space (~8K for now)
+                  MAX_HEADER is not enough.
+                */
+               head_room = opt->opt_nflen + opt->opt_flen;
+               seg_len += head_room;
+               head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
+
+               if (skb_headroom(skb) < head_room) {
+                       struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
+                       if (skb2 == NULL) {
+                               IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                                             IPSTATS_MIB_OUTDISCARDS);
+                               kfree_skb(skb);
+                               return -ENOBUFS;
+                       }
+                       consume_skb(skb);
+                       skb = skb2;
+                       skb_set_owner_w(skb, sk);
+               }
+               if (opt->opt_flen)
+                       ipv6_push_frag_opts(skb, opt, &proto);
+               if (opt->opt_nflen)
+                       ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
+       }
+
+       skb_push(skb, sizeof(struct ipv6hdr));
+       skb_reset_network_header(skb);
+       hdr = ipv6_hdr(skb);
+
+       /*
+        *      Fill in the IPv6 header
+        */
+       if (np)
+               hlimit = np->hop_limit;
+       if (hlimit < 0)
+               hlimit = ip6_dst_hoplimit(dst);
+
+       ip6_flow_hdr(hdr, tclass, fl6->flowlabel);
+
+       hdr->payload_len = htons(seg_len);
+       hdr->nexthdr = proto;
+       hdr->hop_limit = hlimit;
+
+       hdr->saddr = fl6->saddr;
+       hdr->daddr = *first_hop;
+
+       skb->priority = sk->sk_priority;
+       skb->mark = sk->sk_mark;
+
+       mtu = dst_mtu(dst);
+       if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
+               IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                             IPSTATS_MIB_OUT, skb->len);
+               return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
+                              dst->dev, dst_output);
+       }
+
+       skb->dev = dst->dev;
+       ipv6_local_error(sk, EMSGSIZE, fl6, mtu);
+       IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
+       kfree_skb(skb);
+       return -EMSGSIZE;
+}
+
+EXPORT_SYMBOL(ip6_xmit);
+
+static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
+{
+       struct ip6_ra_chain *ra;
+       struct sock *last = NULL;
+
+       read_lock(&ip6_ra_lock);
+       for (ra = ip6_ra_chain; ra; ra = ra->next) {
+               struct sock *sk = ra->sk;
+               if (sk && ra->sel == sel &&
+                   (!sk->sk_bound_dev_if ||
+                    sk->sk_bound_dev_if == skb->dev->ifindex)) {
+                       if (last) {
+                               struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+                               if (skb2)
+                                       rawv6_rcv(last, skb2);
+                       }
+                       last = sk;
+               }
+       }
+
+       if (last) {
+               rawv6_rcv(last, skb);
+               read_unlock(&ip6_ra_lock);
+               return 1;
+       }
+       read_unlock(&ip6_ra_lock);
+       return 0;
+}
+
+static int ip6_forward_proxy_check(struct sk_buff *skb)
+{
+       struct ipv6hdr *hdr = ipv6_hdr(skb);
+       u8 nexthdr = hdr->nexthdr;
+       __be16 frag_off;
+       int offset;
+
+       if (ipv6_ext_hdr(nexthdr)) {
+               offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
+               if (offset < 0)
+                       return 0;
+       } else
+               offset = sizeof(struct ipv6hdr);
+
+       if (nexthdr == IPPROTO_ICMPV6) {
+               struct icmp6hdr *icmp6;
+
+               if (!pskb_may_pull(skb, (skb_network_header(skb) +
+                                        offset + 1 - skb->data)))
+                       return 0;
+
+               icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
+
+               switch (icmp6->icmp6_type) {
+               case NDISC_ROUTER_SOLICITATION:
+               case NDISC_ROUTER_ADVERTISEMENT:
+               case NDISC_NEIGHBOUR_SOLICITATION:
+               case NDISC_NEIGHBOUR_ADVERTISEMENT:
+               case NDISC_REDIRECT:
+                       /* For reaction involving unicast neighbor discovery
+                        * message destined to the proxied address, pass it to
+                        * input function.
+                        */
+                       return 1;
+               default:
+                       break;
+               }
+       }
+
+       /*
+        * The proxying router can't forward traffic sent to a link-local
+        * address, so signal the sender and discard the packet. This
+        * behavior is clarified by the MIPv6 specification.
+        */
+       if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
+               dst_link_failure(skb);
+               return -1;
+       }
+
+       return 0;
+}
+
+static inline int ip6_forward_finish(struct sk_buff *skb)
+{
+       return dst_output(skb);
+}
+
+int ip6_forward(struct sk_buff *skb)
+{
+       struct dst_entry *dst = skb_dst(skb);
+       struct ipv6hdr *hdr = ipv6_hdr(skb);
+       struct inet6_skb_parm *opt = IP6CB(skb);
+       struct net *net = dev_net(dst->dev);
+       u32 mtu;
+
+       if (net->ipv6.devconf_all->forwarding == 0)
+               goto error;
+
+       if (skb_warn_if_lro(skb))
+               goto drop;
+
+       if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
+               IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
+               goto drop;
+       }
+
+       if (skb->pkt_type != PACKET_HOST)
+               goto drop;
+
+       skb_forward_csum(skb);
+
+       /*
+        *      We DO NOT make any processing on
+        *      RA packets, pushing them to user level AS IS
+        *      without ane WARRANTY that application will be able
+        *      to interpret them. The reason is that we
+        *      cannot make anything clever here.
+        *
+        *      We are not end-node, so that if packet contains
+        *      AH/ESP, we cannot make anything.
+        *      Defragmentation also would be mistake, RA packets
+        *      cannot be fragmented, because there is no warranty
+        *      that different fragments will go along one path. --ANK
+        */
+       if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
+               if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
+                       return 0;
+       }
+
+       /*
+        *      check and decrement ttl
+        */
+       if (hdr->hop_limit <= 1) {
+               /* Force OUTPUT device used as source address */
+               skb->dev = dst->dev;
+               icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
+               IP6_INC_STATS_BH(net,
+                                ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
+
+               kfree_skb(skb);
+               return -ETIMEDOUT;
+       }
+
+       /* XXX: idev->cnf.proxy_ndp? */
+       if (net->ipv6.devconf_all->proxy_ndp &&
+           pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
+               int proxied = ip6_forward_proxy_check(skb);
+               if (proxied > 0)
+                       return ip6_input(skb);
+               else if (proxied < 0) {
+                       IP6_INC_STATS(net, ip6_dst_idev(dst),
+                                     IPSTATS_MIB_INDISCARDS);
+                       goto drop;
+               }
+       }
+
+       if (!xfrm6_route_forward(skb)) {
+               IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
+               goto drop;
+       }
+       dst = skb_dst(skb);
+
+       /* IPv6 specs say nothing about it, but it is clear that we cannot
+          send redirects to source routed frames.
+          We don't send redirects to frames decapsulated from IPsec.
+        */
+       if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
+               struct in6_addr *target = NULL;
+               struct inet_peer *peer;
+               struct rt6_info *rt;
+
+               /*
+                *      incoming and outgoing devices are the same
+                *      send a redirect.
+                */
+
+               rt = (struct rt6_info *) dst;
+               if (rt->rt6i_flags & RTF_GATEWAY)
+                       target = &rt->rt6i_gateway;
+               else
+                       target = &hdr->daddr;
+
+               peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
+
+               /* Limit redirects both by destination (here)
+                  and by source (inside ndisc_send_redirect)
+                */
+               if (inet_peer_xrlim_allow(peer, 1*HZ))
+                       ndisc_send_redirect(skb, target);
+               if (peer)
+                       inet_putpeer(peer);
+       } else {
+               int addrtype = ipv6_addr_type(&hdr->saddr);
+
+               /* This check is security critical. */
+               if (addrtype == IPV6_ADDR_ANY ||
+                   addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
+                       goto error;
+               if (addrtype & IPV6_ADDR_LINKLOCAL) {
+                       icmpv6_send(skb, ICMPV6_DEST_UNREACH,
+                                   ICMPV6_NOT_NEIGHBOUR, 0);
+                       goto error;
+               }
+       }
+
+       mtu = dst_mtu(dst);
+       if (mtu < IPV6_MIN_MTU)
+               mtu = IPV6_MIN_MTU;
+
+       if ((!skb->local_df && skb->len > mtu && !skb_is_gso(skb)) ||
+           (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) {
+               /* Again, force OUTPUT device used as source address */
+               skb->dev = dst->dev;
+               icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+               IP6_INC_STATS_BH(net,
+                                ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
+               IP6_INC_STATS_BH(net,
+                                ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
+               kfree_skb(skb);
+               return -EMSGSIZE;
+       }
+
+       if (skb_cow(skb, dst->dev->hard_header_len)) {
+               IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
+               goto drop;
+       }
+
+       hdr = ipv6_hdr(skb);
+
+       /* Mangling hops number delayed to point after skb COW */
+
+       hdr->hop_limit--;
+
+       IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
+       IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
+       return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
+                      ip6_forward_finish);
+
+error:
+       IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS);
+drop:
+       kfree_skb(skb);
+       return -EINVAL;
+}
+
+static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
+{
+       to->pkt_type = from->pkt_type;
+       to->priority = from->priority;
+       to->protocol = from->protocol;
+       skb_dst_drop(to);
+       skb_dst_set(to, dst_clone(skb_dst(from)));
+       to->dev = from->dev;
+       to->mark = from->mark;
+
+#ifdef CONFIG_NET_SCHED
+       to->tc_index = from->tc_index;
+#endif
+       nf_copy(to, from);
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
+       to->nf_trace = from->nf_trace;
+#endif
+       skb_copy_secmark(to, from);
+}
+
+int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
+{
+       struct sk_buff *frag;
+       struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
+       struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
+       struct ipv6hdr *tmp_hdr;
+       struct frag_hdr *fh;
+       unsigned int mtu, hlen, left, len;
+       int hroom, troom;
+       __be32 frag_id = 0;
+       int ptr, offset = 0, err=0;
+       u8 *prevhdr, nexthdr = 0;
+       struct net *net = dev_net(skb_dst(skb)->dev);
+
+       hlen = ip6_find_1stfragopt(skb, &prevhdr);
+       nexthdr = *prevhdr;
+
+       mtu = ip6_skb_dst_mtu(skb);
+
+       /* We must not fragment if the socket is set to force MTU discovery
+        * or if the skb it not generated by a local socket.
+        */
+       if (unlikely(!skb->local_df && skb->len > mtu) ||
+                    (IP6CB(skb)->frag_max_size &&
+                     IP6CB(skb)->frag_max_size > mtu)) {
+               if (skb->sk && dst_allfrag(skb_dst(skb)))
+                       sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
+
+               skb->dev = skb_dst(skb)->dev;
+               icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+               IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                             IPSTATS_MIB_FRAGFAILS);
+               kfree_skb(skb);
+               return -EMSGSIZE;
+       }
+
+       if (np && np->frag_size < mtu) {
+               if (np->frag_size)
+                       mtu = np->frag_size;
+       }
+       mtu -= hlen + sizeof(struct frag_hdr);
+
+       if (skb_has_frag_list(skb)) {
+               int first_len = skb_pagelen(skb);
+               struct sk_buff *frag2;
+
+               if (first_len - hlen > mtu ||
+                   ((first_len - hlen) & 7) ||
+                   skb_cloned(skb))
+                       goto slow_path;
+
+               skb_walk_frags(skb, frag) {
+                       /* Correct geometry. */
+                       if (frag->len > mtu ||
+                           ((frag->len & 7) && frag->next) ||
+                           skb_headroom(frag) < hlen)
+                               goto slow_path_clean;
+
+                       /* Partially cloned skb? */
+                       if (skb_shared(frag))
+                               goto slow_path_clean;
+
+                       BUG_ON(frag->sk);
+                       if (skb->sk) {
+                               frag->sk = skb->sk;
+                               frag->destructor = sock_wfree;
+                       }
+                       skb->truesize -= frag->truesize;
+               }
+
+               err = 0;
+               offset = 0;
+               frag = skb_shinfo(skb)->frag_list;
+               skb_frag_list_init(skb);
+               /* BUILD HEADER */
+
+               *prevhdr = NEXTHDR_FRAGMENT;
+               tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
+               if (!tmp_hdr) {
+                       IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                                     IPSTATS_MIB_FRAGFAILS);
+                       return -ENOMEM;
+               }
+
+               __skb_pull(skb, hlen);
+               fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
+               __skb_push(skb, hlen);
+               skb_reset_network_header(skb);
+               memcpy(skb_network_header(skb), tmp_hdr, hlen);
+
+               ipv6_select_ident(fh, rt);
+               fh->nexthdr = nexthdr;
+               fh->reserved = 0;
+               fh->frag_off = htons(IP6_MF);
+               frag_id = fh->identification;
+
+               first_len = skb_pagelen(skb);
+               skb->data_len = first_len - skb_headlen(skb);
+               skb->len = first_len;
+               ipv6_hdr(skb)->payload_len = htons(first_len -
+                                                  sizeof(struct ipv6hdr));
+
+               dst_hold(&rt->dst);
+
+               for (;;) {
+                       /* Prepare header of the next frame,
+                        * before previous one went down. */
+                       if (frag) {
+                               frag->ip_summed = CHECKSUM_NONE;
+                               skb_reset_transport_header(frag);
+                               fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
+                               __skb_push(frag, hlen);
+                               skb_reset_network_header(frag);
+                               memcpy(skb_network_header(frag), tmp_hdr,
+                                      hlen);
+                               offset += skb->len - hlen - sizeof(struct frag_hdr);
+                               fh->nexthdr = nexthdr;
+                               fh->reserved = 0;
+                               fh->frag_off = htons(offset);
+                               if (frag->next != NULL)
+                                       fh->frag_off |= htons(IP6_MF);
+                               fh->identification = frag_id;
+                               ipv6_hdr(frag)->payload_len =
+                                               htons(frag->len -
+                                                     sizeof(struct ipv6hdr));
+                               ip6_copy_metadata(frag, skb);
+                       }
+
+                       err = output(skb);
+                       if(!err)
+                               IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+                                             IPSTATS_MIB_FRAGCREATES);
+
+                       if (err || !frag)
+                               break;
+
+                       skb = frag;
+                       frag = skb->next;
+                       skb->next = NULL;
+               }
+
+               kfree(tmp_hdr);
+
+               if (err == 0) {
+                       IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+                                     IPSTATS_MIB_FRAGOKS);
+                       ip6_rt_put(rt);
+                       return 0;
+               }
+
+               while (frag) {
+                       skb = frag->next;
+                       kfree_skb(frag);
+                       frag = skb;
+               }
+
+               IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
+                             IPSTATS_MIB_FRAGFAILS);
+               ip6_rt_put(rt);
+               return err;
+
+slow_path_clean:
+               skb_walk_frags(skb, frag2) {
+                       if (frag2 == frag)
+                               break;
+                       frag2->sk = NULL;
+                       frag2->destructor = NULL;
+                       skb->truesize += frag2->truesize;
+               }
+       }
+
+slow_path:
+       if ((skb->ip_summed == CHECKSUM_PARTIAL) &&
+           skb_checksum_help(skb))
+               goto fail;
+
+       left = skb->len - hlen;         /* Space per frame */
+       ptr = hlen;                     /* Where to start from */
+
+       /*
+        *      Fragment the datagram.
+        */
+
+       *prevhdr = NEXTHDR_FRAGMENT;
+       hroom = LL_RESERVED_SPACE(rt->dst.dev);
+       troom = rt->dst.dev->needed_tailroom;
+
+       /*
+        *      Keep copying data until we run out.
+        */
+       while(left > 0) {
+               len = left;
+               /* IF: it doesn't fit, use 'mtu' - the data space left */
+               if (len > mtu)
+                       len = mtu;
+               /* IF: we are not sending up to and including the packet end
+                  then align the next start on an eight byte boundary */
+               if (len < left) {
+                       len &= ~7;
+               }
+               /*
+                *      Allocate buffer.
+                */
+
+               if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) +
+                                     hroom + troom, GFP_ATOMIC)) == NULL) {
+                       NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
+                       IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                                     IPSTATS_MIB_FRAGFAILS);
+                       err = -ENOMEM;
+                       goto fail;
+               }
+
+               /*
+                *      Set up data on packet
+                */
+
+               ip6_copy_metadata(frag, skb);
+               skb_reserve(frag, hroom);
+               skb_put(frag, len + hlen + sizeof(struct frag_hdr));
+               skb_reset_network_header(frag);
+               fh = (struct frag_hdr *)(skb_network_header(frag) + hlen);
+               frag->transport_header = (frag->network_header + hlen +
+                                         sizeof(struct frag_hdr));
+
+               /*
+                *      Charge the memory for the fragment to any owner
+                *      it might possess
+                */
+               if (skb->sk)
+                       skb_set_owner_w(frag, skb->sk);
+
+               /*
+                *      Copy the packet header into the new buffer.
+                */
+               skb_copy_from_linear_data(skb, skb_network_header(frag), hlen);
+
+               /*
+                *      Build fragment header.
+                */
+               fh->nexthdr = nexthdr;
+               fh->reserved = 0;
+               if (!frag_id) {
+                       ipv6_select_ident(fh, rt);
+                       frag_id = fh->identification;
+               } else
+                       fh->identification = frag_id;
+
+               /*
+                *      Copy a block of the IP datagram.
+                */
+               if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
+                       BUG();
+               left -= len;
+
+               fh->frag_off = htons(offset);
+               if (left > 0)
+                       fh->frag_off |= htons(IP6_MF);
+               ipv6_hdr(frag)->payload_len = htons(frag->len -
+                                                   sizeof(struct ipv6hdr));
+
+               ptr += len;
+               offset += len;
+
+               /*
+                *      Put this fragment into the sending queue.
+                */
+               err = output(frag);
+               if (err)
+                       goto fail;
+
+               IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                             IPSTATS_MIB_FRAGCREATES);
+       }
+       IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                     IPSTATS_MIB_FRAGOKS);
+       consume_skb(skb);
+       return err;
+
+fail:
+       IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+                     IPSTATS_MIB_FRAGFAILS);
+       kfree_skb(skb);
+       return err;
+}
+
+static inline int ip6_rt_check(const struct rt6key *rt_key,
+                              const struct in6_addr *fl_addr,
+                              const struct in6_addr *addr_cache)
+{
+       return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
+               (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
+}
+
+static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
+                                         struct dst_entry *dst,
+                                         const struct flowi6 *fl6)
+{
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct rt6_info *rt;
+
+       if (!dst)
+               goto out;
+
+       if (dst->ops->family != AF_INET6) {
+               dst_release(dst);
+               return NULL;
+       }
+
+       rt = (struct rt6_info *)dst;
+       /* Yes, checking route validity in not connected
+        * case is not very simple. Take into account,
+        * that we do not support routing by source, TOS,
+        * and MSG_DONTROUTE            --ANK (980726)
+        *
+        * 1. ip6_rt_check(): If route was host route,
+        *    check that cached destination is current.
+        *    If it is network route, we still may
+        *    check its validity using saved pointer
+        *    to the last used address: daddr_cache.
+        *    We do not want to save whole address now,
+        *    (because main consumer of this service
+        *    is tcp, which has not this problem),
+        *    so that the last trick works only on connected
+        *    sockets.
+        * 2. oif also should be the same.
+        */
+       if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
+#ifdef CONFIG_IPV6_SUBTREES
+           ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
+#endif
+           (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
+               dst_release(dst);
+               dst = NULL;
+       }
+
+out:
+       return dst;
+}
+
+static int ip6_dst_lookup_tail(struct sock *sk,
+                              struct dst_entry **dst, struct flowi6 *fl6)
+{
+       struct net *net = sock_net(sk);
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+       struct neighbour *n;
+       struct rt6_info *rt;
+#endif
+       int err;
+
+       if (*dst == NULL)
+               *dst = ip6_route_output(net, sk, fl6);
+
+       if ((err = (*dst)->error))
+               goto out_err_release;
+
+       if (ipv6_addr_any(&fl6->saddr)) {
+               struct rt6_info *rt = (struct rt6_info *) *dst;
+               err = ip6_route_get_saddr(net, rt, &fl6->daddr,
+                                         sk ? inet6_sk(sk)->srcprefs : 0,
+                                         &fl6->saddr);
+               if (err)
+                       goto out_err_release;
+       }
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+       /*
+        * Here if the dst entry we've looked up
+        * has a neighbour entry that is in the INCOMPLETE
+        * state and the src address from the flow is
+        * marked as OPTIMISTIC, we release the found
+        * dst entry and replace it instead with the
+        * dst entry of the nexthop router
+        */
+       rt = (struct rt6_info *) *dst;
+       rcu_read_lock_bh();
+       n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt));
+       err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
+       rcu_read_unlock_bh();
+
+       if (err) {
+               struct inet6_ifaddr *ifp;
+               struct flowi6 fl_gw6;
+               int redirect;
+
+               ifp = ipv6_get_ifaddr(net, &fl6->saddr,
+                                     (*dst)->dev, 1);
+
+               redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
+               if (ifp)
+                       in6_ifa_put(ifp);
+
+               if (redirect) {
+                       /*
+                        * We need to get the dst entry for the
+                        * default router instead
+                        */
+                       dst_release(*dst);
+                       memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
+                       memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
+                       *dst = ip6_route_output(net, sk, &fl_gw6);
+                       if ((err = (*dst)->error))
+                               goto out_err_release;
+               }
+       }
+#endif
+
+       return 0;
+
+out_err_release:
+       if (err == -ENETUNREACH)
+               IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES);
+       dst_release(*dst);
+       *dst = NULL;
+       return err;
+}
+
+/**
+ *     ip6_dst_lookup - perform route lookup on flow
+ *     @sk: socket which provides route info
+ *     @dst: pointer to dst_entry * for result
+ *     @fl6: flow to lookup
+ *
+ *     This function performs a route lookup on the given flow.
+ *
+ *     It returns zero on success, or a standard errno code on error.
+ */
+int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6)
+{
+       *dst = NULL;
+       return ip6_dst_lookup_tail(sk, dst, fl6);
+}
+EXPORT_SYMBOL_GPL(ip6_dst_lookup);
+
+/**
+ *     ip6_dst_lookup_flow - perform route lookup on flow with ipsec
+ *     @sk: socket which provides route info
+ *     @fl6: flow to lookup
+ *     @final_dst: final destination address for ipsec lookup
+ *     @can_sleep: we are in a sleepable context
+ *
+ *     This function performs a route lookup on the given flow.
+ *
+ *     It returns a valid dst pointer on success, or a pointer encoded
+ *     error code.
+ */
+struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
+                                     const struct in6_addr *final_dst,
+                                     bool can_sleep)
+{
+       struct dst_entry *dst = NULL;
+       int err;
+
+       err = ip6_dst_lookup_tail(sk, &dst, fl6);
+       if (err)
+               return ERR_PTR(err);
+       if (final_dst)
+               fl6->daddr = *final_dst;
+       if (can_sleep)
+               fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
+
+       return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
+}
+EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
+
+/**
+ *     ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
+ *     @sk: socket which provides the dst cache and route info
+ *     @fl6: flow to lookup
+ *     @final_dst: final destination address for ipsec lookup
+ *     @can_sleep: we are in a sleepable context
+ *
+ *     This function performs a route lookup on the given flow with the
+ *     possibility of using the cached route in the socket if it is valid.
+ *     It will take the socket dst lock when operating on the dst cache.
+ *     As a result, this function can only be used in process context.
+ *
+ *     It returns a valid dst pointer on success, or a pointer encoded
+ *     error code.
+ */
+struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
+                                        const struct in6_addr *final_dst,
+                                        bool can_sleep)
+{
+       struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
+       int err;
+
+       dst = ip6_sk_dst_check(sk, dst, fl6);
+
+       err = ip6_dst_lookup_tail(sk, &dst, fl6);
+       if (err)
+               return ERR_PTR(err);
+       if (final_dst)
+               fl6->daddr = *final_dst;
+       if (can_sleep)
+               fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
+
+       return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
+
+static inline int ip6_ufo_append_data(struct sock *sk,
+                       int getfrag(void *from, char *to, int offset, int len,
+                       int odd, struct sk_buff *skb),
+                       void *from, int length, int hh_len, int fragheaderlen,
+                       int transhdrlen, int mtu,unsigned int flags,
+                       struct rt6_info *rt)
+
+{
+       struct sk_buff *skb;
+       int err;
+
+       /* There is support for UDP large send offload by network
+        * device, so create one single skb packet containing complete
+        * udp datagram
+        */
+       if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
+               struct frag_hdr fhdr;
+
+               skb = sock_alloc_send_skb(sk,
+                       hh_len + fragheaderlen + transhdrlen + 20,
+                       (flags & MSG_DONTWAIT), &err);
+               if (skb == NULL)
+                       return err;
+
+               /* reserve space for Hardware header */
+               skb_reserve(skb, hh_len);
+
+               /* create space for UDP/IP header */
+               skb_put(skb,fragheaderlen + transhdrlen);
+
+               /* initialize network header pointer */
+               skb_reset_network_header(skb);
+
+               /* initialize protocol header pointer */
+               skb->transport_header = skb->network_header + fragheaderlen;
+
+               skb->ip_summed = CHECKSUM_PARTIAL;
+               skb->csum = 0;
+
+               /* Specify the length of each IPv6 datagram fragment.
+                * It has to be a multiple of 8.
+                */
+               skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
+                                            sizeof(struct frag_hdr)) & ~7;
+               skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
+               ipv6_select_ident(&fhdr, rt);
+               skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
+               __skb_queue_tail(&sk->sk_write_queue, skb);
+       }
+
+       return skb_append_datato_frags(sk, skb, getfrag, from,
+                                      (length - transhdrlen));
+}
+
+static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
+                                              gfp_t gfp)
+{
+       return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
+}
+
+static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
+                                               gfp_t gfp)
+{
+       return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
+}
+
+static void ip6_append_data_mtu(unsigned int *mtu,
+                               int *maxfraglen,
+                               unsigned int fragheaderlen,
+                               struct sk_buff *skb,
+                               struct rt6_info *rt,
+                               bool pmtuprobe)
+{
+       if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
+               if (skb == NULL) {
+                       /* first fragment, reserve header_len */
+                       *mtu = *mtu - rt->dst.header_len;
+
+               } else {
+                       /*
+                        * this fragment is not first, the headers
+                        * space is regarded as data space.
+                        */
+                       *mtu = min(*mtu, pmtuprobe ?
+                                  rt->dst.dev->mtu :
+                                  dst_mtu(rt->dst.path));
+               }
+               *maxfraglen = ((*mtu - fragheaderlen) & ~7)
+                             + fragheaderlen - sizeof(struct frag_hdr);
+       }
+}
+
+int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
+       int offset, int len, int odd, struct sk_buff *skb),
+       void *from, int length, int transhdrlen,
+       int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
+       struct rt6_info *rt, unsigned int flags, int dontfrag)
+{
+       struct inet_sock *inet = inet_sk(sk);
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct inet_cork *cork;
+       struct sk_buff *skb, *skb_prev = NULL;
+       unsigned int maxfraglen, fragheaderlen, mtu;
+       int exthdrlen;
+       int dst_exthdrlen;
+       int hh_len;
+       int copy;
+       int err;
+       int offset = 0;
+       __u8 tx_flags = 0;
+
+       if (flags&MSG_PROBE)
+               return 0;
+       cork = &inet->cork.base;
+       if (skb_queue_empty(&sk->sk_write_queue)) {
+               /*
+                * setup for corking
+                */
+               if (opt) {
+                       if (WARN_ON(np->cork.opt))
+                               return -EINVAL;
+
+                       np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation);
+                       if (unlikely(np->cork.opt == NULL))
+                               return -ENOBUFS;
+
+                       np->cork.opt->tot_len = opt->tot_len;
+                       np->cork.opt->opt_flen = opt->opt_flen;
+                       np->cork.opt->opt_nflen = opt->opt_nflen;
+
+                       np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt,
+                                                           sk->sk_allocation);
+                       if (opt->dst0opt && !np->cork.opt->dst0opt)
+                               return -ENOBUFS;
+
+                       np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt,
+                                                           sk->sk_allocation);
+                       if (opt->dst1opt && !np->cork.opt->dst1opt)
+                               return -ENOBUFS;
+
+                       np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt,
+                                                          sk->sk_allocation);
+                       if (opt->hopopt && !np->cork.opt->hopopt)
+                               return -ENOBUFS;
+
+                       np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt,
+                                                           sk->sk_allocation);
+                       if (opt->srcrt && !np->cork.opt->srcrt)
+                               return -ENOBUFS;
+
+                       /* need source address above miyazawa*/
+               }
+               dst_hold(&rt->dst);
+               cork->dst = &rt->dst;
+               inet->cork.fl.u.ip6 = *fl6;
+               np->cork.hop_limit = hlimit;
+               np->cork.tclass = tclass;
+               if (rt->dst.flags & DST_XFRM_TUNNEL)
+                       mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+                             rt->dst.dev->mtu : dst_mtu(&rt->dst);
+               else
+                       mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+                             rt->dst.dev->mtu : dst_mtu(rt->dst.path);
+               if (np->frag_size < mtu) {
+                       if (np->frag_size)
+                               mtu = np->frag_size;
+               }
+               cork->fragsize = mtu;
+               if (dst_allfrag(rt->dst.path))
+                       cork->flags |= IPCORK_ALLFRAG;
+               cork->length = 0;
+               exthdrlen = (opt ? opt->opt_flen : 0);
+               length += exthdrlen;
+               transhdrlen += exthdrlen;
+               dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
+       } else {
+               rt = (struct rt6_info *)cork->dst;
+               fl6 = &inet->cork.fl.u.ip6;
+               opt = np->cork.opt;
+               transhdrlen = 0;
+               exthdrlen = 0;
+               dst_exthdrlen = 0;
+               mtu = cork->fragsize;
+       }
+
+       hh_len = LL_RESERVED_SPACE(rt->dst.dev);
+
+       fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
+                       (opt ? opt->opt_nflen : 0);
+       maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
+
+       if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
+               if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
+                       ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
+                       return -EMSGSIZE;
+               }
+       }
+
+       /* For UDP, check if TX timestamp is enabled */
+       if (sk->sk_type == SOCK_DGRAM)
+               sock_tx_timestamp(sk, &tx_flags);
+
+       /*
+        * Let's try using as much space as possible.
+        * Use MTU if total length of the message fits into the MTU.
+        * Otherwise, we need to reserve fragment header and
+        * fragment alignment (= 8-15 octects, in total).
+        *
+        * Note that we may need to "move" the data from the tail of
+        * of the buffer to the new fragment when we split
+        * the message.
+        *
+        * FIXME: It may be fragmented into multiple chunks
+        *        at once if non-fragmentable extension headers
+        *        are too large.
+        * --yoshfuji
+        */
+
+       if ((length > mtu) && dontfrag && (sk->sk_protocol == IPPROTO_UDP ||
+                                          sk->sk_protocol == IPPROTO_RAW)) {
+               ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
+               return -EMSGSIZE;
+       }
+
+       skb = skb_peek_tail(&sk->sk_write_queue);
+       cork->length += length;
+       if (((length > mtu) ||
+            (skb && skb_has_frags(skb))) &&
+           (sk->sk_protocol == IPPROTO_UDP) &&
+           (rt->dst.dev->features & NETIF_F_UFO)) {
+               err = ip6_ufo_append_data(sk, getfrag, from, length,
+                                         hh_len, fragheaderlen,
+                                         transhdrlen, mtu, flags, rt);
+               if (err)
+                       goto error;
+               return 0;
+       }
+
+       if (!skb)
+               goto alloc_new_skb;
+
+       while (length > 0) {
+               /* Check if the remaining data fits into current packet. */
+               copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
+               if (copy < length)
+                       copy = maxfraglen - skb->len;
+
+               if (copy <= 0) {
+                       char *data;
+                       unsigned int datalen;
+                       unsigned int fraglen;
+                       unsigned int fraggap;
+                       unsigned int alloclen;
+alloc_new_skb:
+                       /* There's no room in the current skb */
+                       if (skb)
+                               fraggap = skb->len - maxfraglen;
+                       else
+                               fraggap = 0;
+                       /* update mtu and maxfraglen if necessary */
+                       if (skb == NULL || skb_prev == NULL)
+                               ip6_append_data_mtu(&mtu, &maxfraglen,
+                                                   fragheaderlen, skb, rt,
+                                                   np->pmtudisc ==
+                                                   IPV6_PMTUDISC_PROBE);
+
+                       skb_prev = skb;
+
+                       /*
+                        * If remaining data exceeds the mtu,
+                        * we know we need more fragment(s).
+                        */
+                       datalen = length + fraggap;
+
+                       if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
+                               datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
+                       if ((flags & MSG_MORE) &&
+                           !(rt->dst.dev->features&NETIF_F_SG))
+                               alloclen = mtu;
+                       else
+                               alloclen = datalen + fragheaderlen;
+
+                       alloclen += dst_exthdrlen;
+
+                       if (datalen != length + fraggap) {
+                               /*
+                                * this is not the last fragment, the trailer
+                                * space is regarded as data space.
+                                */
+                               datalen += rt->dst.trailer_len;
+                       }
+
+                       alloclen += rt->dst.trailer_len;
+                       fraglen = datalen + fragheaderlen;
+
+                       /*
+                        * We just reserve space for fragment header.
+                        * Note: this may be overallocation if the message
+                        * (without MSG_MORE) fits into the MTU.
+                        */
+                       alloclen += sizeof(struct frag_hdr);
+
+                       if (transhdrlen) {
+                               skb = sock_alloc_send_skb(sk,
+                                               alloclen + hh_len,
+                                               (flags & MSG_DONTWAIT), &err);
+                       } else {
+                               skb = NULL;
+                               if (atomic_read(&sk->sk_wmem_alloc) <=
+                                   2 * sk->sk_sndbuf)
+                                       skb = sock_wmalloc(sk,
+                                                          alloclen + hh_len, 1,
+                                                          sk->sk_allocation);
+                               if (unlikely(skb == NULL))
+                                       err = -ENOBUFS;
+                               else {
+                                       /* Only the initial fragment
+                                        * is time stamped.
+                                        */
+                                       tx_flags = 0;
+                               }
+                       }
+                       if (skb == NULL)
+                               goto error;
+                       /*
+                        *      Fill in the control structures
+                        */
+                       skb->ip_summed = CHECKSUM_NONE;
+                       skb->csum = 0;
+                       /* reserve for fragmentation and ipsec header */
+                       skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
+                                   dst_exthdrlen);
+
+                       if (sk->sk_type == SOCK_DGRAM)
+                               skb_shinfo(skb)->tx_flags = tx_flags;
+
+                       /*
+                        *      Find where to start putting bytes
+                        */
+                       data = skb_put(skb, fraglen);
+                       skb_set_network_header(skb, exthdrlen);
+                       data += fragheaderlen;
+                       skb->transport_header = (skb->network_header +
+                                                fragheaderlen);
+                       if (fraggap) {
+                               skb->csum = skb_copy_and_csum_bits(
+                                       skb_prev, maxfraglen,
+                                       data + transhdrlen, fraggap, 0);
+                               skb_prev->csum = csum_sub(skb_prev->csum,
+                                                         skb->csum);
+                               data += fraggap;
+                               pskb_trim_unique(skb_prev, maxfraglen);
+                       }
+                       copy = datalen - transhdrlen - fraggap;
+
+                       if (copy < 0) {
+                               err = -EINVAL;
+                               kfree_skb(skb);
+                               goto error;
+                       } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+                               err = -EFAULT;
+                               kfree_skb(skb);
+                               goto error;
+                       }
+
+                       offset += copy;
+                       length -= datalen - fraggap;
+                       transhdrlen = 0;
+                       exthdrlen = 0;
+                       dst_exthdrlen = 0;
+
+                       /*
+                        * Put the packet on the pending queue
+                        */
+                       __skb_queue_tail(&sk->sk_write_queue, skb);
+                       continue;
+               }
+
+               if (copy > length)
+                       copy = length;
+
+               if (!(rt->dst.dev->features&NETIF_F_SG)) {
+                       unsigned int off;
+
+                       off = skb->len;
+                       if (getfrag(from, skb_put(skb, copy),
+                                               offset, copy, off, skb) < 0) {
+                               __skb_trim(skb, off);
+                               err = -EFAULT;
+                               goto error;
+                       }
+               } else {
+                       int i = skb_shinfo(skb)->nr_frags;
+                       struct page_frag *pfrag = sk_page_frag(sk);
+
+                       err = -ENOMEM;
+                       if (!sk_page_frag_refill(sk, pfrag))
+                               goto error;
+
+                       if (!skb_can_coalesce(skb, i, pfrag->page,
+                                             pfrag->offset)) {
+                               err = -EMSGSIZE;
+                               if (i == MAX_SKB_FRAGS)
+                                       goto error;
+
+                               __skb_fill_page_desc(skb, i, pfrag->page,
+                                                    pfrag->offset, 0);
+                               skb_shinfo(skb)->nr_frags = ++i;
+                               get_page(pfrag->page);
+                       }
+                       copy = min_t(int, copy, pfrag->size - pfrag->offset);
+                       if (getfrag(from,
+                                   page_address(pfrag->page) + pfrag->offset,
+                                   offset, copy, skb->len, skb) < 0)
+                               goto error_efault;
+
+                       pfrag->offset += copy;
+                       skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
+                       skb->len += copy;
+                       skb->data_len += copy;
+                       skb->truesize += copy;
+                       atomic_add(copy, &sk->sk_wmem_alloc);
+               }
+               offset += copy;
+               length -= copy;
+       }
+
+       return 0;
+
+error_efault:
+       err = -EFAULT;
+error:
+       cork->length -= length;
+       IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
+       return err;
+}
+EXPORT_SYMBOL_GPL(ip6_append_data);
+
+static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
+{
+       if (np->cork.opt) {
+               kfree(np->cork.opt->dst0opt);
+               kfree(np->cork.opt->dst1opt);
+               kfree(np->cork.opt->hopopt);
+               kfree(np->cork.opt->srcrt);
+               kfree(np->cork.opt);
+               np->cork.opt = NULL;
+       }
+
+       if (inet->cork.base.dst) {
+               dst_release(inet->cork.base.dst);
+               inet->cork.base.dst = NULL;
+               inet->cork.base.flags &= ~IPCORK_ALLFRAG;
+       }
+       memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
+}
+
+int ip6_push_pending_frames(struct sock *sk)
+{
+       struct sk_buff *skb, *tmp_skb;
+       struct sk_buff **tail_skb;
+       struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
+       struct inet_sock *inet = inet_sk(sk);
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       struct net *net = sock_net(sk);
+       struct ipv6hdr *hdr;
+       struct ipv6_txoptions *opt = np->cork.opt;
+       struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
+       struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
+       unsigned char proto = fl6->flowi6_proto;
+       int err = 0;
+
+       if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
+               goto out;
+       tail_skb = &(skb_shinfo(skb)->frag_list);
+
+       /* move skb->data to ip header from ext header */
+       if (skb->data < skb_network_header(skb))
+               __skb_pull(skb, skb_network_offset(skb));
+       while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
+               __skb_pull(tmp_skb, skb_network_header_len(skb));
+               *tail_skb = tmp_skb;
+               tail_skb = &(tmp_skb->next);
+               skb->len += tmp_skb->len;
+               skb->data_len += tmp_skb->len;
+               skb->truesize += tmp_skb->truesize;
+               tmp_skb->destructor = NULL;
+               tmp_skb->sk = NULL;
+       }
+
+       /* Allow local fragmentation. */
+       if (np->pmtudisc < IPV6_PMTUDISC_DO)
+               skb->local_df = 1;
+
+       *final_dst = fl6->daddr;
+       __skb_pull(skb, skb_network_header_len(skb));
+       if (opt && opt->opt_flen)
+               ipv6_push_frag_opts(skb, opt, &proto);
+       if (opt && opt->opt_nflen)
+               ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
+
+       skb_push(skb, sizeof(struct ipv6hdr));
+       skb_reset_network_header(skb);
+       hdr = ipv6_hdr(skb);
+
+       ip6_flow_hdr(hdr, np->cork.tclass, fl6->flowlabel);
+       hdr->hop_limit = np->cork.hop_limit;
+       hdr->nexthdr = proto;
+       hdr->saddr = fl6->saddr;
+       hdr->daddr = *final_dst;
+
+       skb->priority = sk->sk_priority;
+       skb->mark = sk->sk_mark;
+
+       skb_dst_set(skb, dst_clone(&rt->dst));
+       IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);
+       if (proto == IPPROTO_ICMPV6) {
+               struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
+
+               ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
+               ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
+       }
+
+       err = ip6_local_out(skb);
+       if (err) {
+               if (err > 0)
+                       err = net_xmit_errno(err);
+               if (err)
+                       goto error;
+       }
+
+out:
+       ip6_cork_release(inet, np);
+       return err;
+error:
+       IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
+       goto out;
+}
+EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
+
+void ip6_flush_pending_frames(struct sock *sk)
+{
+       struct sk_buff *skb;
+
+       while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
+               if (skb_dst(skb))
+                       IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
+                                     IPSTATS_MIB_OUTDISCARDS);
+               kfree_skb(skb);
+       }
+
+       ip6_cork_release(inet_sk(sk), inet6_sk(sk));
+}
+EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
diff -ruN linux-3.10.27/net/netfilter/core.c linux-3.10.27-imq/net/netfilter/core.c
--- linux-3.10.27/net/netfilter/core.c  2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/core.c      2014-01-18 10:19:59.349342984 +0100
@@ -191,9 +191,11 @@
                ret = NF_DROP_GETERR(verdict);
                if (ret == 0)
                        ret = -EPERM;
-       } else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) {
+       } else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE ||
+                  (verdict & NF_VERDICT_MASK) == NF_IMQ_QUEUE) {
                int err = nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
-                                               verdict >> NF_VERDICT_QBITS);
+                                               verdict >> NF_VERDICT_QBITS,
+                                               verdict & NF_VERDICT_MASK);
                if (err < 0) {
                        if (err == -ECANCELED)
                                goto next_hook;
diff -ruN linux-3.10.27/net/netfilter/Kconfig linux-3.10.27-imq/net/netfilter/Kconfig
--- linux-3.10.27/net/netfilter/Kconfig 2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/Kconfig     2014-01-18 10:19:59.349342984 +0100
@@ -641,6 +641,18 @@
 
          To compile it as a module, choose M here.  If unsure, say N.
 
+config NETFILTER_XT_TARGET_IMQ
+        tristate '"IMQ" target support'
+       depends on NETFILTER_XTABLES
+       depends on IP_NF_MANGLE || IP6_NF_MANGLE
+       select IMQ
+       default m if NETFILTER_ADVANCED=n
+        help
+          This option adds a `IMQ' target which is used to specify if and
+          to which imq device packets should get enqueued/dequeued.
+
+          To compile it as a module, choose M here.  If unsure, say N.
+
 config NETFILTER_XT_TARGET_MARK
        tristate '"MARK" target support'
        depends on NETFILTER_ADVANCED
diff -ruN linux-3.10.27/net/netfilter/Makefile linux-3.10.27-imq/net/netfilter/Makefile
--- linux-3.10.27/net/netfilter/Makefile        2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/Makefile    2014-01-18 10:19:59.349342984 +0100
@@ -82,6 +82,7 @@
 obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_HMARK) += xt_HMARK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_IMQ) += xt_IMQ.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_LOG) += xt_LOG.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NETMAP) += xt_NETMAP.o
diff -ruN linux-3.10.27/net/netfilter/nf_internals.h linux-3.10.27-imq/net/netfilter/nf_internals.h
--- linux-3.10.27/net/netfilter/nf_internals.h  2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/nf_internals.h      2014-01-18 10:19:59.349342984 +0100
@@ -29,7 +29,7 @@
                    struct net_device *indev,
                    struct net_device *outdev,
                    int (*okfn)(struct sk_buff *),
-                   unsigned int queuenum);
+                   unsigned int queuenum, unsigned int queuetype);
 extern int __init netfilter_queue_init(void);
 
 /* nf_log.c */
diff -ruN linux-3.10.27/net/netfilter/nf_queue.c linux-3.10.27-imq/net/netfilter/nf_queue.c
--- linux-3.10.27/net/netfilter/nf_queue.c      2014-01-16 00:29:14.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/nf_queue.c  2014-01-18 10:19:59.350342998 +0100
@@ -27,6 +27,23 @@
  */
 static const struct nf_queue_handler __rcu *queue_handler __read_mostly;
 
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+static const struct nf_queue_handler __rcu *queue_imq_handler __read_mostly;
+
+void nf_register_queue_imq_handler(const struct nf_queue_handler *qh)
+{
+       rcu_assign_pointer(queue_imq_handler, qh);
+}
+EXPORT_SYMBOL_GPL(nf_register_queue_imq_handler);
+
+void nf_unregister_queue_imq_handler(void)
+{
+       RCU_INIT_POINTER(queue_imq_handler, NULL);
+       synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(nf_unregister_queue_imq_handler);
+#endif
+
 /* return EBUSY when somebody else is registered, return EEXIST if the
  * same handler is registered, return 0 in case of success. */
 void nf_register_queue_handler(const struct nf_queue_handler *qh)
@@ -105,7 +122,8 @@
                      struct net_device *indev,
                      struct net_device *outdev,
                      int (*okfn)(struct sk_buff *),
-                     unsigned int queuenum)
+                     unsigned int queuenum,
+                     unsigned int queuetype)
 {
        int status = -ENOENT;
        struct nf_queue_entry *entry = NULL;
@@ -115,7 +133,17 @@
        /* QUEUE == DROP if no one is waiting, to be safe. */
        rcu_read_lock();
 
-       qh = rcu_dereference(queue_handler);
+       if (queuetype == NF_IMQ_QUEUE) {
+#if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
+               qh = rcu_dereference(queue_imq_handler);
+#else
+               BUG();
+               goto err_unlock;
+#endif
+       } else {
+               qh = rcu_dereference(queue_handler);
+       }
+
        if (!qh) {
                status = -ESRCH;
                goto err_unlock;
@@ -205,9 +233,11 @@
                local_bh_enable();
                break;
        case NF_QUEUE:
+       case NF_IMQ_QUEUE:
                err = nf_queue(skb, elem, entry->pf, entry->hook,
                                entry->indev, entry->outdev, entry->okfn,
-                               verdict >> NF_VERDICT_QBITS);
+                               verdict >> NF_VERDICT_QBITS,
+                               verdict & NF_VERDICT_MASK);
                if (err < 0) {
                        if (err == -ECANCELED)
                                goto next_hook;
diff -ruN linux-3.10.27/net/netfilter/xt_IMQ.c linux-3.10.27-imq/net/netfilter/xt_IMQ.c
--- linux-3.10.27/net/netfilter/xt_IMQ.c        1970-01-01 01:00:00.000000000 +0100
+++ linux-3.10.27-imq/net/netfilter/xt_IMQ.c    2014-01-18 10:19:59.350342998 +0100
@@ -0,0 +1,72 @@
+/*
+ * This target marks packets to be enqueued to an imq device
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_IMQ.h>
+#include <linux/imq.h>
+
+static unsigned int imq_target(struct sk_buff *pskb,
+                               const struct xt_action_param *par)
+{
+       const struct xt_imq_info *mr = par->targinfo;
+
+       pskb->imq_flags = (mr->todev & IMQ_F_IFMASK) | IMQ_F_ENQUEUE;
+
+       return XT_CONTINUE;
+}
+
+static int imq_checkentry(const struct xt_tgchk_param *par)
+{
+       struct xt_imq_info *mr = par->targinfo;
+
+       if (mr->todev > IMQ_MAX_DEVS - 1) {
+               pr_warn("IMQ: invalid device specified, highest is %u\n",
+                       IMQ_MAX_DEVS - 1);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static struct xt_target xt_imq_reg[] __read_mostly = {
+       {
+               .name           = "IMQ",
+               .family         = AF_INET,
+               .checkentry     = imq_checkentry,
+               .target         = imq_target,
+               .targetsize     = sizeof(struct xt_imq_info),
+               .table          = "mangle",
+               .me             = THIS_MODULE
+       },
+       {
+               .name           = "IMQ",
+               .family         = AF_INET6,
+               .checkentry     = imq_checkentry,
+               .target         = imq_target,
+               .targetsize     = sizeof(struct xt_imq_info),
+               .table          = "mangle",
+               .me             = THIS_MODULE
+       },
+};
+
+static int __init imq_init(void)
+{
+       return xt_register_targets(xt_imq_reg, ARRAY_SIZE(xt_imq_reg));
+}
+
+static void __exit imq_fini(void)
+{
+       xt_unregister_targets(xt_imq_reg, ARRAY_SIZE(xt_imq_reg));
+}
+
+module_init(imq_init);
+module_exit(imq_fini);
+
+MODULE_AUTHOR("http://www.linuximq.net");
+MODULE_DESCRIPTION("Pseudo-driver for the intermediate queue device. See http://www.linuximq.net/ for more information.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_IMQ");
+MODULE_ALIAS("ip6t_IMQ");
+