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Merge tag 'xfs-6.10-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
[thirdparty/kernel/stable.git] / net / ipv6 / ip6_output.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * IPv6 output functions
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on linux/net/ipv4/ip_output.c
10 *
11 * Changes:
12 * A.N.Kuznetsov : airthmetics in fragmentation.
13 * extension headers are implemented.
14 * route changes now work.
15 * ip6_forward does not confuse sniffers.
16 * etc.
17 *
18 * H. von Brand : Added missing #include <linux/string.h>
19 * Imran Patel : frag id should be in NBO
20 * Kazunori MIYAZAWA @USAGI
21 * : add ip6_append_data and related functions
22 * for datagram xmit
23 */
24
25 #include <linux/errno.h>
26 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/socket.h>
29 #include <linux/net.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/in6.h>
33 #include <linux/tcp.h>
34 #include <linux/route.h>
35 #include <linux/module.h>
36 #include <linux/slab.h>
37
38 #include <linux/bpf-cgroup.h>
39 #include <linux/netfilter.h>
40 #include <linux/netfilter_ipv6.h>
41
42 #include <net/sock.h>
43 #include <net/snmp.h>
44
45 #include <net/gso.h>
46 #include <net/ipv6.h>
47 #include <net/ndisc.h>
48 #include <net/protocol.h>
49 #include <net/ip6_route.h>
50 #include <net/addrconf.h>
51 #include <net/rawv6.h>
52 #include <net/icmp.h>
53 #include <net/xfrm.h>
54 #include <net/checksum.h>
55 #include <linux/mroute6.h>
56 #include <net/l3mdev.h>
57 #include <net/lwtunnel.h>
58 #include <net/ip_tunnels.h>
59
60 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
61 {
62 struct dst_entry *dst = skb_dst(skb);
63 struct net_device *dev = dst->dev;
64 struct inet6_dev *idev = ip6_dst_idev(dst);
65 unsigned int hh_len = LL_RESERVED_SPACE(dev);
66 const struct in6_addr *daddr, *nexthop;
67 struct ipv6hdr *hdr;
68 struct neighbour *neigh;
69 int ret;
70
71 /* Be paranoid, rather than too clever. */
72 if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) {
73 skb = skb_expand_head(skb, hh_len);
74 if (!skb) {
75 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
76 return -ENOMEM;
77 }
78 }
79
80 hdr = ipv6_hdr(skb);
81 daddr = &hdr->daddr;
82 if (ipv6_addr_is_multicast(daddr)) {
83 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
84 ((mroute6_is_socket(net, skb) &&
85 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
86 ipv6_chk_mcast_addr(dev, daddr, &hdr->saddr))) {
87 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
88
89 /* Do not check for IFF_ALLMULTI; multicast routing
90 is not supported in any case.
91 */
92 if (newskb)
93 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
94 net, sk, newskb, NULL, newskb->dev,
95 dev_loopback_xmit);
96
97 if (hdr->hop_limit == 0) {
98 IP6_INC_STATS(net, idev,
99 IPSTATS_MIB_OUTDISCARDS);
100 kfree_skb(skb);
101 return 0;
102 }
103 }
104
105 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len);
106 if (IPV6_ADDR_MC_SCOPE(daddr) <= IPV6_ADDR_SCOPE_NODELOCAL &&
107 !(dev->flags & IFF_LOOPBACK)) {
108 kfree_skb(skb);
109 return 0;
110 }
111 }
112
113 if (lwtunnel_xmit_redirect(dst->lwtstate)) {
114 int res = lwtunnel_xmit(skb);
115
116 if (res != LWTUNNEL_XMIT_CONTINUE)
117 return res;
118 }
119
120 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
121
122 rcu_read_lock();
123 nexthop = rt6_nexthop(dst_rt6_info(dst), daddr);
124 neigh = __ipv6_neigh_lookup_noref(dev, nexthop);
125
126 if (unlikely(IS_ERR_OR_NULL(neigh))) {
127 if (unlikely(!neigh))
128 neigh = __neigh_create(&nd_tbl, nexthop, dev, false);
129 if (IS_ERR(neigh)) {
130 rcu_read_unlock();
131 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES);
132 kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
133 return -EINVAL;
134 }
135 }
136 sock_confirm_neigh(skb, neigh);
137 ret = neigh_output(neigh, skb, false);
138 rcu_read_unlock();
139 return ret;
140 }
141
142 static int
143 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk,
144 struct sk_buff *skb, unsigned int mtu)
145 {
146 struct sk_buff *segs, *nskb;
147 netdev_features_t features;
148 int ret = 0;
149
150 /* Please see corresponding comment in ip_finish_output_gso
151 * describing the cases where GSO segment length exceeds the
152 * egress MTU.
153 */
154 features = netif_skb_features(skb);
155 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
156 if (IS_ERR_OR_NULL(segs)) {
157 kfree_skb(skb);
158 return -ENOMEM;
159 }
160
161 consume_skb(skb);
162
163 skb_list_walk_safe(segs, segs, nskb) {
164 int err;
165
166 skb_mark_not_on_list(segs);
167 /* Last GSO segment can be smaller than gso_size (and MTU).
168 * Adding a fragment header would produce an "atomic fragment",
169 * which is considered harmful (RFC-8021). Avoid that.
170 */
171 err = segs->len > mtu ?
172 ip6_fragment(net, sk, segs, ip6_finish_output2) :
173 ip6_finish_output2(net, sk, segs);
174 if (err && ret == 0)
175 ret = err;
176 }
177
178 return ret;
179 }
180
181 static int ip6_finish_output_gso(struct net *net, struct sock *sk,
182 struct sk_buff *skb, unsigned int mtu)
183 {
184 if (!(IP6CB(skb)->flags & IP6SKB_FAKEJUMBO) &&
185 !skb_gso_validate_network_len(skb, mtu))
186 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu);
187
188 return ip6_finish_output2(net, sk, skb);
189 }
190
191 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
192 {
193 unsigned int mtu;
194
195 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
196 /* Policy lookup after SNAT yielded a new policy */
197 if (skb_dst(skb)->xfrm) {
198 IP6CB(skb)->flags |= IP6SKB_REROUTED;
199 return dst_output(net, sk, skb);
200 }
201 #endif
202
203 mtu = ip6_skb_dst_mtu(skb);
204 if (skb_is_gso(skb))
205 return ip6_finish_output_gso(net, sk, skb, mtu);
206
207 if (skb->len > mtu ||
208 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
209 return ip6_fragment(net, sk, skb, ip6_finish_output2);
210
211 return ip6_finish_output2(net, sk, skb);
212 }
213
214 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
215 {
216 int ret;
217
218 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
219 switch (ret) {
220 case NET_XMIT_SUCCESS:
221 case NET_XMIT_CN:
222 return __ip6_finish_output(net, sk, skb) ? : ret;
223 default:
224 kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS);
225 return ret;
226 }
227 }
228
229 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
230 {
231 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev;
232 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
233
234 skb->protocol = htons(ETH_P_IPV6);
235 skb->dev = dev;
236
237 if (unlikely(!idev || READ_ONCE(idev->cnf.disable_ipv6))) {
238 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
239 kfree_skb_reason(skb, SKB_DROP_REASON_IPV6DISABLED);
240 return 0;
241 }
242
243 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
244 net, sk, skb, indev, dev,
245 ip6_finish_output,
246 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
247 }
248 EXPORT_SYMBOL(ip6_output);
249
250 bool ip6_autoflowlabel(struct net *net, const struct sock *sk)
251 {
252 if (!inet6_test_bit(AUTOFLOWLABEL_SET, sk))
253 return ip6_default_np_autolabel(net);
254 return inet6_test_bit(AUTOFLOWLABEL, sk);
255 }
256
257 /*
258 * xmit an sk_buff (used by TCP, SCTP and DCCP)
259 * Note : socket lock is not held for SYNACK packets, but might be modified
260 * by calls to skb_set_owner_w() and ipv6_local_error(),
261 * which are using proper atomic operations or spinlocks.
262 */
263 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
264 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority)
265 {
266 struct net *net = sock_net(sk);
267 const struct ipv6_pinfo *np = inet6_sk(sk);
268 struct in6_addr *first_hop = &fl6->daddr;
269 struct dst_entry *dst = skb_dst(skb);
270 struct net_device *dev = dst->dev;
271 struct inet6_dev *idev = ip6_dst_idev(dst);
272 struct hop_jumbo_hdr *hop_jumbo;
273 int hoplen = sizeof(*hop_jumbo);
274 unsigned int head_room;
275 struct ipv6hdr *hdr;
276 u8 proto = fl6->flowi6_proto;
277 int seg_len = skb->len;
278 int hlimit = -1;
279 u32 mtu;
280
281 head_room = sizeof(struct ipv6hdr) + hoplen + LL_RESERVED_SPACE(dev);
282 if (opt)
283 head_room += opt->opt_nflen + opt->opt_flen;
284
285 if (unlikely(head_room > skb_headroom(skb))) {
286 skb = skb_expand_head(skb, head_room);
287 if (!skb) {
288 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
289 return -ENOBUFS;
290 }
291 }
292
293 if (opt) {
294 seg_len += opt->opt_nflen + opt->opt_flen;
295
296 if (opt->opt_flen)
297 ipv6_push_frag_opts(skb, opt, &proto);
298
299 if (opt->opt_nflen)
300 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop,
301 &fl6->saddr);
302 }
303
304 if (unlikely(seg_len > IPV6_MAXPLEN)) {
305 hop_jumbo = skb_push(skb, hoplen);
306
307 hop_jumbo->nexthdr = proto;
308 hop_jumbo->hdrlen = 0;
309 hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
310 hop_jumbo->tlv_len = 4;
311 hop_jumbo->jumbo_payload_len = htonl(seg_len + hoplen);
312
313 proto = IPPROTO_HOPOPTS;
314 seg_len = 0;
315 IP6CB(skb)->flags |= IP6SKB_FAKEJUMBO;
316 }
317
318 skb_push(skb, sizeof(struct ipv6hdr));
319 skb_reset_network_header(skb);
320 hdr = ipv6_hdr(skb);
321
322 /*
323 * Fill in the IPv6 header
324 */
325 if (np)
326 hlimit = READ_ONCE(np->hop_limit);
327 if (hlimit < 0)
328 hlimit = ip6_dst_hoplimit(dst);
329
330 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
331 ip6_autoflowlabel(net, sk), fl6));
332
333 hdr->payload_len = htons(seg_len);
334 hdr->nexthdr = proto;
335 hdr->hop_limit = hlimit;
336
337 hdr->saddr = fl6->saddr;
338 hdr->daddr = *first_hop;
339
340 skb->protocol = htons(ETH_P_IPV6);
341 skb->priority = priority;
342 skb->mark = mark;
343
344 mtu = dst_mtu(dst);
345 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
346 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
347
348 /* if egress device is enslaved to an L3 master device pass the
349 * skb to its handler for processing
350 */
351 skb = l3mdev_ip6_out((struct sock *)sk, skb);
352 if (unlikely(!skb))
353 return 0;
354
355 /* hooks should never assume socket lock is held.
356 * we promote our socket to non const
357 */
358 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
359 net, (struct sock *)sk, skb, NULL, dev,
360 dst_output);
361 }
362
363 skb->dev = dev;
364 /* ipv6_local_error() does not require socket lock,
365 * we promote our socket to non const
366 */
367 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
368
369 IP6_INC_STATS(net, idev, IPSTATS_MIB_FRAGFAILS);
370 kfree_skb(skb);
371 return -EMSGSIZE;
372 }
373 EXPORT_SYMBOL(ip6_xmit);
374
375 static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
376 {
377 struct ip6_ra_chain *ra;
378 struct sock *last = NULL;
379
380 read_lock(&ip6_ra_lock);
381 for (ra = ip6_ra_chain; ra; ra = ra->next) {
382 struct sock *sk = ra->sk;
383 if (sk && ra->sel == sel &&
384 (!sk->sk_bound_dev_if ||
385 sk->sk_bound_dev_if == skb->dev->ifindex)) {
386
387 if (inet6_test_bit(RTALERT_ISOLATE, sk) &&
388 !net_eq(sock_net(sk), dev_net(skb->dev))) {
389 continue;
390 }
391 if (last) {
392 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
393 if (skb2)
394 rawv6_rcv(last, skb2);
395 }
396 last = sk;
397 }
398 }
399
400 if (last) {
401 rawv6_rcv(last, skb);
402 read_unlock(&ip6_ra_lock);
403 return 1;
404 }
405 read_unlock(&ip6_ra_lock);
406 return 0;
407 }
408
409 static int ip6_forward_proxy_check(struct sk_buff *skb)
410 {
411 struct ipv6hdr *hdr = ipv6_hdr(skb);
412 u8 nexthdr = hdr->nexthdr;
413 __be16 frag_off;
414 int offset;
415
416 if (ipv6_ext_hdr(nexthdr)) {
417 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off);
418 if (offset < 0)
419 return 0;
420 } else
421 offset = sizeof(struct ipv6hdr);
422
423 if (nexthdr == IPPROTO_ICMPV6) {
424 struct icmp6hdr *icmp6;
425
426 if (!pskb_may_pull(skb, (skb_network_header(skb) +
427 offset + 1 - skb->data)))
428 return 0;
429
430 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
431
432 switch (icmp6->icmp6_type) {
433 case NDISC_ROUTER_SOLICITATION:
434 case NDISC_ROUTER_ADVERTISEMENT:
435 case NDISC_NEIGHBOUR_SOLICITATION:
436 case NDISC_NEIGHBOUR_ADVERTISEMENT:
437 case NDISC_REDIRECT:
438 /* For reaction involving unicast neighbor discovery
439 * message destined to the proxied address, pass it to
440 * input function.
441 */
442 return 1;
443 default:
444 break;
445 }
446 }
447
448 /*
449 * The proxying router can't forward traffic sent to a link-local
450 * address, so signal the sender and discard the packet. This
451 * behavior is clarified by the MIPv6 specification.
452 */
453 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) {
454 dst_link_failure(skb);
455 return -1;
456 }
457
458 return 0;
459 }
460
461 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
462 struct sk_buff *skb)
463 {
464 #ifdef CONFIG_NET_SWITCHDEV
465 if (skb->offload_l3_fwd_mark) {
466 consume_skb(skb);
467 return 0;
468 }
469 #endif
470
471 skb_clear_tstamp(skb);
472 return dst_output(net, sk, skb);
473 }
474
475 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
476 {
477 if (skb->len <= mtu)
478 return false;
479
480 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */
481 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
482 return true;
483
484 if (skb->ignore_df)
485 return false;
486
487 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
488 return false;
489
490 return true;
491 }
492
493 int ip6_forward(struct sk_buff *skb)
494 {
495 struct dst_entry *dst = skb_dst(skb);
496 struct ipv6hdr *hdr = ipv6_hdr(skb);
497 struct inet6_skb_parm *opt = IP6CB(skb);
498 struct net *net = dev_net(dst->dev);
499 struct inet6_dev *idev;
500 SKB_DR(reason);
501 u32 mtu;
502
503 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
504 if (READ_ONCE(net->ipv6.devconf_all->forwarding) == 0)
505 goto error;
506
507 if (skb->pkt_type != PACKET_HOST)
508 goto drop;
509
510 if (unlikely(skb->sk))
511 goto drop;
512
513 if (skb_warn_if_lro(skb))
514 goto drop;
515
516 if (!READ_ONCE(net->ipv6.devconf_all->disable_policy) &&
517 (!idev || !READ_ONCE(idev->cnf.disable_policy)) &&
518 !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
519 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
520 goto drop;
521 }
522
523 skb_forward_csum(skb);
524
525 /*
526 * We DO NOT make any processing on
527 * RA packets, pushing them to user level AS IS
528 * without ane WARRANTY that application will be able
529 * to interpret them. The reason is that we
530 * cannot make anything clever here.
531 *
532 * We are not end-node, so that if packet contains
533 * AH/ESP, we cannot make anything.
534 * Defragmentation also would be mistake, RA packets
535 * cannot be fragmented, because there is no warranty
536 * that different fragments will go along one path. --ANK
537 */
538 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
539 if (ip6_call_ra_chain(skb, ntohs(opt->ra)))
540 return 0;
541 }
542
543 /*
544 * check and decrement ttl
545 */
546 if (hdr->hop_limit <= 1) {
547 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
548 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
549
550 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
551 return -ETIMEDOUT;
552 }
553
554 /* XXX: idev->cnf.proxy_ndp? */
555 if (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
556 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
557 int proxied = ip6_forward_proxy_check(skb);
558 if (proxied > 0) {
559 /* It's tempting to decrease the hop limit
560 * here by 1, as we do at the end of the
561 * function too.
562 *
563 * But that would be incorrect, as proxying is
564 * not forwarding. The ip6_input function
565 * will handle this packet locally, and it
566 * depends on the hop limit being unchanged.
567 *
568 * One example is the NDP hop limit, that
569 * always has to stay 255, but other would be
570 * similar checks around RA packets, where the
571 * user can even change the desired limit.
572 */
573 return ip6_input(skb);
574 } else if (proxied < 0) {
575 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
576 goto drop;
577 }
578 }
579
580 if (!xfrm6_route_forward(skb)) {
581 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
582 SKB_DR_SET(reason, XFRM_POLICY);
583 goto drop;
584 }
585 dst = skb_dst(skb);
586
587 /* IPv6 specs say nothing about it, but it is clear that we cannot
588 send redirects to source routed frames.
589 We don't send redirects to frames decapsulated from IPsec.
590 */
591 if (IP6CB(skb)->iif == dst->dev->ifindex &&
592 opt->srcrt == 0 && !skb_sec_path(skb)) {
593 struct in6_addr *target = NULL;
594 struct inet_peer *peer;
595 struct rt6_info *rt;
596
597 /*
598 * incoming and outgoing devices are the same
599 * send a redirect.
600 */
601
602 rt = dst_rt6_info(dst);
603 if (rt->rt6i_flags & RTF_GATEWAY)
604 target = &rt->rt6i_gateway;
605 else
606 target = &hdr->daddr;
607
608 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
609
610 /* Limit redirects both by destination (here)
611 and by source (inside ndisc_send_redirect)
612 */
613 if (inet_peer_xrlim_allow(peer, 1*HZ))
614 ndisc_send_redirect(skb, target);
615 if (peer)
616 inet_putpeer(peer);
617 } else {
618 int addrtype = ipv6_addr_type(&hdr->saddr);
619
620 /* This check is security critical. */
621 if (addrtype == IPV6_ADDR_ANY ||
622 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK))
623 goto error;
624 if (addrtype & IPV6_ADDR_LINKLOCAL) {
625 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
626 ICMPV6_NOT_NEIGHBOUR, 0);
627 goto error;
628 }
629 }
630
631 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
632
633 mtu = ip6_dst_mtu_maybe_forward(dst, true);
634 if (mtu < IPV6_MIN_MTU)
635 mtu = IPV6_MIN_MTU;
636
637 if (ip6_pkt_too_big(skb, mtu)) {
638 /* Again, force OUTPUT device used as source address */
639 skb->dev = dst->dev;
640 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
641 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS);
642 __IP6_INC_STATS(net, ip6_dst_idev(dst),
643 IPSTATS_MIB_FRAGFAILS);
644 kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG);
645 return -EMSGSIZE;
646 }
647
648 if (skb_cow(skb, dst->dev->hard_header_len)) {
649 __IP6_INC_STATS(net, ip6_dst_idev(dst),
650 IPSTATS_MIB_OUTDISCARDS);
651 goto drop;
652 }
653
654 hdr = ipv6_hdr(skb);
655
656 /* Mangling hops number delayed to point after skb COW */
657
658 hdr->hop_limit--;
659
660 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
661 net, NULL, skb, skb->dev, dst->dev,
662 ip6_forward_finish);
663
664 error:
665 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
666 SKB_DR_SET(reason, IP_INADDRERRORS);
667 drop:
668 kfree_skb_reason(skb, reason);
669 return -EINVAL;
670 }
671
672 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
673 {
674 to->pkt_type = from->pkt_type;
675 to->priority = from->priority;
676 to->protocol = from->protocol;
677 skb_dst_drop(to);
678 skb_dst_set(to, dst_clone(skb_dst(from)));
679 to->dev = from->dev;
680 to->mark = from->mark;
681
682 skb_copy_hash(to, from);
683
684 #ifdef CONFIG_NET_SCHED
685 to->tc_index = from->tc_index;
686 #endif
687 nf_copy(to, from);
688 skb_ext_copy(to, from);
689 skb_copy_secmark(to, from);
690 }
691
692 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
693 u8 nexthdr, __be32 frag_id,
694 struct ip6_fraglist_iter *iter)
695 {
696 unsigned int first_len;
697 struct frag_hdr *fh;
698
699 /* BUILD HEADER */
700 *prevhdr = NEXTHDR_FRAGMENT;
701 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
702 if (!iter->tmp_hdr)
703 return -ENOMEM;
704
705 iter->frag = skb_shinfo(skb)->frag_list;
706 skb_frag_list_init(skb);
707
708 iter->offset = 0;
709 iter->hlen = hlen;
710 iter->frag_id = frag_id;
711 iter->nexthdr = nexthdr;
712
713 __skb_pull(skb, hlen);
714 fh = __skb_push(skb, sizeof(struct frag_hdr));
715 __skb_push(skb, hlen);
716 skb_reset_network_header(skb);
717 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen);
718
719 fh->nexthdr = nexthdr;
720 fh->reserved = 0;
721 fh->frag_off = htons(IP6_MF);
722 fh->identification = frag_id;
723
724 first_len = skb_pagelen(skb);
725 skb->data_len = first_len - skb_headlen(skb);
726 skb->len = first_len;
727 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr));
728
729 return 0;
730 }
731 EXPORT_SYMBOL(ip6_fraglist_init);
732
733 void ip6_fraglist_prepare(struct sk_buff *skb,
734 struct ip6_fraglist_iter *iter)
735 {
736 struct sk_buff *frag = iter->frag;
737 unsigned int hlen = iter->hlen;
738 struct frag_hdr *fh;
739
740 frag->ip_summed = CHECKSUM_NONE;
741 skb_reset_transport_header(frag);
742 fh = __skb_push(frag, sizeof(struct frag_hdr));
743 __skb_push(frag, hlen);
744 skb_reset_network_header(frag);
745 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen);
746 iter->offset += skb->len - hlen - sizeof(struct frag_hdr);
747 fh->nexthdr = iter->nexthdr;
748 fh->reserved = 0;
749 fh->frag_off = htons(iter->offset);
750 if (frag->next)
751 fh->frag_off |= htons(IP6_MF);
752 fh->identification = iter->frag_id;
753 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
754 ip6_copy_metadata(frag, skb);
755 }
756 EXPORT_SYMBOL(ip6_fraglist_prepare);
757
758 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
759 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
760 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state)
761 {
762 state->prevhdr = prevhdr;
763 state->nexthdr = nexthdr;
764 state->frag_id = frag_id;
765
766 state->hlen = hlen;
767 state->mtu = mtu;
768
769 state->left = skb->len - hlen; /* Space per frame */
770 state->ptr = hlen; /* Where to start from */
771
772 state->hroom = hdr_room;
773 state->troom = needed_tailroom;
774
775 state->offset = 0;
776 }
777 EXPORT_SYMBOL(ip6_frag_init);
778
779 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state)
780 {
781 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset;
782 struct sk_buff *frag;
783 struct frag_hdr *fh;
784 unsigned int len;
785
786 len = state->left;
787 /* IF: it doesn't fit, use 'mtu' - the data space left */
788 if (len > state->mtu)
789 len = state->mtu;
790 /* IF: we are not sending up to and including the packet end
791 then align the next start on an eight byte boundary */
792 if (len < state->left)
793 len &= ~7;
794
795 /* Allocate buffer */
796 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) +
797 state->hroom + state->troom, GFP_ATOMIC);
798 if (!frag)
799 return ERR_PTR(-ENOMEM);
800
801 /*
802 * Set up data on packet
803 */
804
805 ip6_copy_metadata(frag, skb);
806 skb_reserve(frag, state->hroom);
807 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr));
808 skb_reset_network_header(frag);
809 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen);
810 frag->transport_header = (frag->network_header + state->hlen +
811 sizeof(struct frag_hdr));
812
813 /*
814 * Charge the memory for the fragment to any owner
815 * it might possess
816 */
817 if (skb->sk)
818 skb_set_owner_w(frag, skb->sk);
819
820 /*
821 * Copy the packet header into the new buffer.
822 */
823 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen);
824
825 fragnexthdr_offset = skb_network_header(frag);
826 fragnexthdr_offset += prevhdr - skb_network_header(skb);
827 *fragnexthdr_offset = NEXTHDR_FRAGMENT;
828
829 /*
830 * Build fragment header.
831 */
832 fh->nexthdr = state->nexthdr;
833 fh->reserved = 0;
834 fh->identification = state->frag_id;
835
836 /*
837 * Copy a block of the IP datagram.
838 */
839 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag),
840 len));
841 state->left -= len;
842
843 fh->frag_off = htons(state->offset);
844 if (state->left > 0)
845 fh->frag_off |= htons(IP6_MF);
846 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
847
848 state->ptr += len;
849 state->offset += len;
850
851 return frag;
852 }
853 EXPORT_SYMBOL(ip6_frag_next);
854
855 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
856 int (*output)(struct net *, struct sock *, struct sk_buff *))
857 {
858 struct sk_buff *frag;
859 struct rt6_info *rt = dst_rt6_info(skb_dst(skb));
860 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
861 inet6_sk(skb->sk) : NULL;
862 bool mono_delivery_time = skb->mono_delivery_time;
863 struct ip6_frag_state state;
864 unsigned int mtu, hlen, nexthdr_offset;
865 ktime_t tstamp = skb->tstamp;
866 int hroom, err = 0;
867 __be32 frag_id;
868 u8 *prevhdr, nexthdr = 0;
869
870 err = ip6_find_1stfragopt(skb, &prevhdr);
871 if (err < 0)
872 goto fail;
873 hlen = err;
874 nexthdr = *prevhdr;
875 nexthdr_offset = prevhdr - skb_network_header(skb);
876
877 mtu = ip6_skb_dst_mtu(skb);
878
879 /* We must not fragment if the socket is set to force MTU discovery
880 * or if the skb it not generated by a local socket.
881 */
882 if (unlikely(!skb->ignore_df && skb->len > mtu))
883 goto fail_toobig;
884
885 if (IP6CB(skb)->frag_max_size) {
886 if (IP6CB(skb)->frag_max_size > mtu)
887 goto fail_toobig;
888
889 /* don't send fragments larger than what we received */
890 mtu = IP6CB(skb)->frag_max_size;
891 if (mtu < IPV6_MIN_MTU)
892 mtu = IPV6_MIN_MTU;
893 }
894
895 if (np) {
896 u32 frag_size = READ_ONCE(np->frag_size);
897
898 if (frag_size && frag_size < mtu)
899 mtu = frag_size;
900 }
901 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
902 goto fail_toobig;
903 mtu -= hlen + sizeof(struct frag_hdr);
904
905 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
906 &ipv6_hdr(skb)->saddr);
907
908 if (skb->ip_summed == CHECKSUM_PARTIAL &&
909 (err = skb_checksum_help(skb)))
910 goto fail;
911
912 prevhdr = skb_network_header(skb) + nexthdr_offset;
913 hroom = LL_RESERVED_SPACE(rt->dst.dev);
914 if (skb_has_frag_list(skb)) {
915 unsigned int first_len = skb_pagelen(skb);
916 struct ip6_fraglist_iter iter;
917 struct sk_buff *frag2;
918
919 if (first_len - hlen > mtu ||
920 ((first_len - hlen) & 7) ||
921 skb_cloned(skb) ||
922 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
923 goto slow_path;
924
925 skb_walk_frags(skb, frag) {
926 /* Correct geometry. */
927 if (frag->len > mtu ||
928 ((frag->len & 7) && frag->next) ||
929 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr)))
930 goto slow_path_clean;
931
932 /* Partially cloned skb? */
933 if (skb_shared(frag))
934 goto slow_path_clean;
935
936 BUG_ON(frag->sk);
937 if (skb->sk) {
938 frag->sk = skb->sk;
939 frag->destructor = sock_wfree;
940 }
941 skb->truesize -= frag->truesize;
942 }
943
944 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
945 &iter);
946 if (err < 0)
947 goto fail;
948
949 /* We prevent @rt from being freed. */
950 rcu_read_lock();
951
952 for (;;) {
953 /* Prepare header of the next frame,
954 * before previous one went down. */
955 if (iter.frag)
956 ip6_fraglist_prepare(skb, &iter);
957
958 skb_set_delivery_time(skb, tstamp, mono_delivery_time);
959 err = output(net, sk, skb);
960 if (!err)
961 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
962 IPSTATS_MIB_FRAGCREATES);
963
964 if (err || !iter.frag)
965 break;
966
967 skb = ip6_fraglist_next(&iter);
968 }
969
970 kfree(iter.tmp_hdr);
971
972 if (err == 0) {
973 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
974 IPSTATS_MIB_FRAGOKS);
975 rcu_read_unlock();
976 return 0;
977 }
978
979 kfree_skb_list(iter.frag);
980
981 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
982 IPSTATS_MIB_FRAGFAILS);
983 rcu_read_unlock();
984 return err;
985
986 slow_path_clean:
987 skb_walk_frags(skb, frag2) {
988 if (frag2 == frag)
989 break;
990 frag2->sk = NULL;
991 frag2->destructor = NULL;
992 skb->truesize += frag2->truesize;
993 }
994 }
995
996 slow_path:
997 /*
998 * Fragment the datagram.
999 */
1000
1001 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom,
1002 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id,
1003 &state);
1004
1005 /*
1006 * Keep copying data until we run out.
1007 */
1008
1009 while (state.left > 0) {
1010 frag = ip6_frag_next(skb, &state);
1011 if (IS_ERR(frag)) {
1012 err = PTR_ERR(frag);
1013 goto fail;
1014 }
1015
1016 /*
1017 * Put this fragment into the sending queue.
1018 */
1019 skb_set_delivery_time(frag, tstamp, mono_delivery_time);
1020 err = output(net, sk, frag);
1021 if (err)
1022 goto fail;
1023
1024 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
1025 IPSTATS_MIB_FRAGCREATES);
1026 }
1027 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
1028 IPSTATS_MIB_FRAGOKS);
1029 consume_skb(skb);
1030 return err;
1031
1032 fail_toobig:
1033 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1034 err = -EMSGSIZE;
1035
1036 fail:
1037 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
1038 IPSTATS_MIB_FRAGFAILS);
1039 kfree_skb(skb);
1040 return err;
1041 }
1042
1043 static inline int ip6_rt_check(const struct rt6key *rt_key,
1044 const struct in6_addr *fl_addr,
1045 const struct in6_addr *addr_cache)
1046 {
1047 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
1048 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
1049 }
1050
1051 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
1052 struct dst_entry *dst,
1053 const struct flowi6 *fl6)
1054 {
1055 struct ipv6_pinfo *np = inet6_sk(sk);
1056 struct rt6_info *rt;
1057
1058 if (!dst)
1059 goto out;
1060
1061 if (dst->ops->family != AF_INET6) {
1062 dst_release(dst);
1063 return NULL;
1064 }
1065
1066 rt = dst_rt6_info(dst);
1067 /* Yes, checking route validity in not connected
1068 * case is not very simple. Take into account,
1069 * that we do not support routing by source, TOS,
1070 * and MSG_DONTROUTE --ANK (980726)
1071 *
1072 * 1. ip6_rt_check(): If route was host route,
1073 * check that cached destination is current.
1074 * If it is network route, we still may
1075 * check its validity using saved pointer
1076 * to the last used address: daddr_cache.
1077 * We do not want to save whole address now,
1078 * (because main consumer of this service
1079 * is tcp, which has not this problem),
1080 * so that the last trick works only on connected
1081 * sockets.
1082 * 2. oif also should be the same.
1083 */
1084 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) ||
1085 #ifdef CONFIG_IPV6_SUBTREES
1086 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) ||
1087 #endif
1088 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) {
1089 dst_release(dst);
1090 dst = NULL;
1091 }
1092
1093 out:
1094 return dst;
1095 }
1096
1097 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
1098 struct dst_entry **dst, struct flowi6 *fl6)
1099 {
1100 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1101 struct neighbour *n;
1102 struct rt6_info *rt;
1103 #endif
1104 int err;
1105 int flags = 0;
1106
1107 /* The correct way to handle this would be to do
1108 * ip6_route_get_saddr, and then ip6_route_output; however,
1109 * the route-specific preferred source forces the
1110 * ip6_route_output call _before_ ip6_route_get_saddr.
1111 *
1112 * In source specific routing (no src=any default route),
1113 * ip6_route_output will fail given src=any saddr, though, so
1114 * that's why we try it again later.
1115 */
1116 if (ipv6_addr_any(&fl6->saddr)) {
1117 struct fib6_info *from;
1118 struct rt6_info *rt;
1119
1120 *dst = ip6_route_output(net, sk, fl6);
1121 rt = (*dst)->error ? NULL : dst_rt6_info(*dst);
1122
1123 rcu_read_lock();
1124 from = rt ? rcu_dereference(rt->from) : NULL;
1125 err = ip6_route_get_saddr(net, from, &fl6->daddr,
1126 sk ? READ_ONCE(inet6_sk(sk)->srcprefs) : 0,
1127 &fl6->saddr);
1128 rcu_read_unlock();
1129
1130 if (err)
1131 goto out_err_release;
1132
1133 /* If we had an erroneous initial result, pretend it
1134 * never existed and let the SA-enabled version take
1135 * over.
1136 */
1137 if ((*dst)->error) {
1138 dst_release(*dst);
1139 *dst = NULL;
1140 }
1141
1142 if (fl6->flowi6_oif)
1143 flags |= RT6_LOOKUP_F_IFACE;
1144 }
1145
1146 if (!*dst)
1147 *dst = ip6_route_output_flags(net, sk, fl6, flags);
1148
1149 err = (*dst)->error;
1150 if (err)
1151 goto out_err_release;
1152
1153 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1154 /*
1155 * Here if the dst entry we've looked up
1156 * has a neighbour entry that is in the INCOMPLETE
1157 * state and the src address from the flow is
1158 * marked as OPTIMISTIC, we release the found
1159 * dst entry and replace it instead with the
1160 * dst entry of the nexthop router
1161 */
1162 rt = dst_rt6_info(*dst);
1163 rcu_read_lock();
1164 n = __ipv6_neigh_lookup_noref(rt->dst.dev,
1165 rt6_nexthop(rt, &fl6->daddr));
1166 err = n && !(READ_ONCE(n->nud_state) & NUD_VALID) ? -EINVAL : 0;
1167 rcu_read_unlock();
1168
1169 if (err) {
1170 struct inet6_ifaddr *ifp;
1171 struct flowi6 fl_gw6;
1172 int redirect;
1173
1174 ifp = ipv6_get_ifaddr(net, &fl6->saddr,
1175 (*dst)->dev, 1);
1176
1177 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
1178 if (ifp)
1179 in6_ifa_put(ifp);
1180
1181 if (redirect) {
1182 /*
1183 * We need to get the dst entry for the
1184 * default router instead
1185 */
1186 dst_release(*dst);
1187 memcpy(&fl_gw6, fl6, sizeof(struct flowi6));
1188 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr));
1189 *dst = ip6_route_output(net, sk, &fl_gw6);
1190 err = (*dst)->error;
1191 if (err)
1192 goto out_err_release;
1193 }
1194 }
1195 #endif
1196 if (ipv6_addr_v4mapped(&fl6->saddr) &&
1197 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) {
1198 err = -EAFNOSUPPORT;
1199 goto out_err_release;
1200 }
1201
1202 return 0;
1203
1204 out_err_release:
1205 dst_release(*dst);
1206 *dst = NULL;
1207
1208 if (err == -ENETUNREACH)
1209 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES);
1210 return err;
1211 }
1212
1213 /**
1214 * ip6_dst_lookup - perform route lookup on flow
1215 * @net: Network namespace to perform lookup in
1216 * @sk: socket which provides route info
1217 * @dst: pointer to dst_entry * for result
1218 * @fl6: flow to lookup
1219 *
1220 * This function performs a route lookup on the given flow.
1221 *
1222 * It returns zero on success, or a standard errno code on error.
1223 */
1224 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1225 struct flowi6 *fl6)
1226 {
1227 *dst = NULL;
1228 return ip6_dst_lookup_tail(net, sk, dst, fl6);
1229 }
1230 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
1231
1232 /**
1233 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec
1234 * @net: Network namespace to perform lookup in
1235 * @sk: socket which provides route info
1236 * @fl6: flow to lookup
1237 * @final_dst: final destination address for ipsec lookup
1238 *
1239 * This function performs a route lookup on the given flow.
1240 *
1241 * It returns a valid dst pointer on success, or a pointer encoded
1242 * error code.
1243 */
1244 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1245 const struct in6_addr *final_dst)
1246 {
1247 struct dst_entry *dst = NULL;
1248 int err;
1249
1250 err = ip6_dst_lookup_tail(net, sk, &dst, fl6);
1251 if (err)
1252 return ERR_PTR(err);
1253 if (final_dst)
1254 fl6->daddr = *final_dst;
1255
1256 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0);
1257 }
1258 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
1259
1260 /**
1261 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow
1262 * @sk: socket which provides the dst cache and route info
1263 * @fl6: flow to lookup
1264 * @final_dst: final destination address for ipsec lookup
1265 * @connected: whether @sk is connected or not
1266 *
1267 * This function performs a route lookup on the given flow with the
1268 * possibility of using the cached route in the socket if it is valid.
1269 * It will take the socket dst lock when operating on the dst cache.
1270 * As a result, this function can only be used in process context.
1271 *
1272 * In addition, for a connected socket, cache the dst in the socket
1273 * if the current cache is not valid.
1274 *
1275 * It returns a valid dst pointer on success, or a pointer encoded
1276 * error code.
1277 */
1278 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1279 const struct in6_addr *final_dst,
1280 bool connected)
1281 {
1282 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
1283
1284 dst = ip6_sk_dst_check(sk, dst, fl6);
1285 if (dst)
1286 return dst;
1287
1288 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst);
1289 if (connected && !IS_ERR(dst))
1290 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
1291
1292 return dst;
1293 }
1294 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
1295
1296 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src,
1297 gfp_t gfp)
1298 {
1299 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1300 }
1301
1302 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
1303 gfp_t gfp)
1304 {
1305 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
1306 }
1307
1308 static void ip6_append_data_mtu(unsigned int *mtu,
1309 int *maxfraglen,
1310 unsigned int fragheaderlen,
1311 struct sk_buff *skb,
1312 struct rt6_info *rt,
1313 unsigned int orig_mtu)
1314 {
1315 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
1316 if (!skb) {
1317 /* first fragment, reserve header_len */
1318 *mtu = orig_mtu - rt->dst.header_len;
1319
1320 } else {
1321 /*
1322 * this fragment is not first, the headers
1323 * space is regarded as data space.
1324 */
1325 *mtu = orig_mtu;
1326 }
1327 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
1328 + fragheaderlen - sizeof(struct frag_hdr);
1329 }
1330 }
1331
1332 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
1333 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
1334 struct rt6_info *rt)
1335 {
1336 struct ipv6_pinfo *np = inet6_sk(sk);
1337 unsigned int mtu, frag_size;
1338 struct ipv6_txoptions *nopt, *opt = ipc6->opt;
1339
1340 /* callers pass dst together with a reference, set it first so
1341 * ip6_cork_release() can put it down even in case of an error.
1342 */
1343 cork->base.dst = &rt->dst;
1344
1345 /*
1346 * setup for corking
1347 */
1348 if (opt) {
1349 if (WARN_ON(v6_cork->opt))
1350 return -EINVAL;
1351
1352 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
1353 if (unlikely(!nopt))
1354 return -ENOBUFS;
1355
1356 nopt->tot_len = sizeof(*opt);
1357 nopt->opt_flen = opt->opt_flen;
1358 nopt->opt_nflen = opt->opt_nflen;
1359
1360 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation);
1361 if (opt->dst0opt && !nopt->dst0opt)
1362 return -ENOBUFS;
1363
1364 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation);
1365 if (opt->dst1opt && !nopt->dst1opt)
1366 return -ENOBUFS;
1367
1368 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation);
1369 if (opt->hopopt && !nopt->hopopt)
1370 return -ENOBUFS;
1371
1372 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation);
1373 if (opt->srcrt && !nopt->srcrt)
1374 return -ENOBUFS;
1375
1376 /* need source address above miyazawa*/
1377 }
1378 v6_cork->hop_limit = ipc6->hlimit;
1379 v6_cork->tclass = ipc6->tclass;
1380 if (rt->dst.flags & DST_XFRM_TUNNEL)
1381 mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ?
1382 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst);
1383 else
1384 mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ?
1385 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst));
1386
1387 frag_size = READ_ONCE(np->frag_size);
1388 if (frag_size && frag_size < mtu)
1389 mtu = frag_size;
1390
1391 cork->base.fragsize = mtu;
1392 cork->base.gso_size = ipc6->gso_size;
1393 cork->base.tx_flags = 0;
1394 cork->base.mark = ipc6->sockc.mark;
1395 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
1396
1397 cork->base.length = 0;
1398 cork->base.transmit_time = ipc6->sockc.transmit_time;
1399
1400 return 0;
1401 }
1402
1403 static int __ip6_append_data(struct sock *sk,
1404 struct sk_buff_head *queue,
1405 struct inet_cork_full *cork_full,
1406 struct inet6_cork *v6_cork,
1407 struct page_frag *pfrag,
1408 int getfrag(void *from, char *to, int offset,
1409 int len, int odd, struct sk_buff *skb),
1410 void *from, size_t length, int transhdrlen,
1411 unsigned int flags, struct ipcm6_cookie *ipc6)
1412 {
1413 struct sk_buff *skb, *skb_prev = NULL;
1414 struct inet_cork *cork = &cork_full->base;
1415 struct flowi6 *fl6 = &cork_full->fl.u.ip6;
1416 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
1417 struct ubuf_info *uarg = NULL;
1418 int exthdrlen = 0;
1419 int dst_exthdrlen = 0;
1420 int hh_len;
1421 int copy;
1422 int err;
1423 int offset = 0;
1424 bool zc = false;
1425 u32 tskey = 0;
1426 struct rt6_info *rt = dst_rt6_info(cork->dst);
1427 bool paged, hold_tskey, extra_uref = false;
1428 struct ipv6_txoptions *opt = v6_cork->opt;
1429 int csummode = CHECKSUM_NONE;
1430 unsigned int maxnonfragsize, headersize;
1431 unsigned int wmem_alloc_delta = 0;
1432
1433 skb = skb_peek_tail(queue);
1434 if (!skb) {
1435 exthdrlen = opt ? opt->opt_flen : 0;
1436 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
1437 }
1438
1439 paged = !!cork->gso_size;
1440 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize;
1441 orig_mtu = mtu;
1442
1443 hh_len = LL_RESERVED_SPACE(rt->dst.dev);
1444
1445 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
1446 (opt ? opt->opt_nflen : 0);
1447
1448 headersize = sizeof(struct ipv6hdr) +
1449 (opt ? opt->opt_flen + opt->opt_nflen : 0) +
1450 rt->rt6i_nfheader_len;
1451
1452 if (mtu <= fragheaderlen ||
1453 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr))
1454 goto emsgsize;
1455
1456 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
1457 sizeof(struct frag_hdr);
1458
1459 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit
1460 * the first fragment
1461 */
1462 if (headersize + transhdrlen > mtu)
1463 goto emsgsize;
1464
1465 if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
1466 (sk->sk_protocol == IPPROTO_UDP ||
1467 sk->sk_protocol == IPPROTO_ICMPV6 ||
1468 sk->sk_protocol == IPPROTO_RAW)) {
1469 ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
1470 sizeof(struct ipv6hdr));
1471 goto emsgsize;
1472 }
1473
1474 if (ip6_sk_ignore_df(sk))
1475 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
1476 else
1477 maxnonfragsize = mtu;
1478
1479 if (cork->length + length > maxnonfragsize - headersize) {
1480 emsgsize:
1481 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0);
1482 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu);
1483 return -EMSGSIZE;
1484 }
1485
1486 /* CHECKSUM_PARTIAL only with no extension headers and when
1487 * we are not going to fragment
1488 */
1489 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
1490 headersize == sizeof(struct ipv6hdr) &&
1491 length <= mtu - headersize &&
1492 (!(flags & MSG_MORE) || cork->gso_size) &&
1493 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
1494 csummode = CHECKSUM_PARTIAL;
1495
1496 if ((flags & MSG_ZEROCOPY) && length) {
1497 struct msghdr *msg = from;
1498
1499 if (getfrag == ip_generic_getfrag && msg->msg_ubuf) {
1500 if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb))
1501 return -EINVAL;
1502
1503 /* Leave uarg NULL if can't zerocopy, callers should
1504 * be able to handle it.
1505 */
1506 if ((rt->dst.dev->features & NETIF_F_SG) &&
1507 csummode == CHECKSUM_PARTIAL) {
1508 paged = true;
1509 zc = true;
1510 uarg = msg->msg_ubuf;
1511 }
1512 } else if (sock_flag(sk, SOCK_ZEROCOPY)) {
1513 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb));
1514 if (!uarg)
1515 return -ENOBUFS;
1516 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */
1517 if (rt->dst.dev->features & NETIF_F_SG &&
1518 csummode == CHECKSUM_PARTIAL) {
1519 paged = true;
1520 zc = true;
1521 } else {
1522 uarg_to_msgzc(uarg)->zerocopy = 0;
1523 skb_zcopy_set(skb, uarg, &extra_uref);
1524 }
1525 }
1526 } else if ((flags & MSG_SPLICE_PAGES) && length) {
1527 if (inet_test_bit(HDRINCL, sk))
1528 return -EPERM;
1529 if (rt->dst.dev->features & NETIF_F_SG &&
1530 getfrag == ip_generic_getfrag)
1531 /* We need an empty buffer to attach stuff to */
1532 paged = true;
1533 else
1534 flags &= ~MSG_SPLICE_PAGES;
1535 }
1536
1537 hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP &&
1538 READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID;
1539 if (hold_tskey)
1540 tskey = atomic_inc_return(&sk->sk_tskey) - 1;
1541
1542 /*
1543 * Let's try using as much space as possible.
1544 * Use MTU if total length of the message fits into the MTU.
1545 * Otherwise, we need to reserve fragment header and
1546 * fragment alignment (= 8-15 octects, in total).
1547 *
1548 * Note that we may need to "move" the data from the tail
1549 * of the buffer to the new fragment when we split
1550 * the message.
1551 *
1552 * FIXME: It may be fragmented into multiple chunks
1553 * at once if non-fragmentable extension headers
1554 * are too large.
1555 * --yoshfuji
1556 */
1557
1558 cork->length += length;
1559 if (!skb)
1560 goto alloc_new_skb;
1561
1562 while (length > 0) {
1563 /* Check if the remaining data fits into current packet. */
1564 copy = (cork->length <= mtu ? mtu : maxfraglen) - skb->len;
1565 if (copy < length)
1566 copy = maxfraglen - skb->len;
1567
1568 if (copy <= 0) {
1569 char *data;
1570 unsigned int datalen;
1571 unsigned int fraglen;
1572 unsigned int fraggap;
1573 unsigned int alloclen, alloc_extra;
1574 unsigned int pagedlen;
1575 alloc_new_skb:
1576 /* There's no room in the current skb */
1577 if (skb)
1578 fraggap = skb->len - maxfraglen;
1579 else
1580 fraggap = 0;
1581 /* update mtu and maxfraglen if necessary */
1582 if (!skb || !skb_prev)
1583 ip6_append_data_mtu(&mtu, &maxfraglen,
1584 fragheaderlen, skb, rt,
1585 orig_mtu);
1586
1587 skb_prev = skb;
1588
1589 /*
1590 * If remaining data exceeds the mtu,
1591 * we know we need more fragment(s).
1592 */
1593 datalen = length + fraggap;
1594
1595 if (datalen > (cork->length <= mtu ? mtu : maxfraglen) - fragheaderlen)
1596 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
1597 fraglen = datalen + fragheaderlen;
1598 pagedlen = 0;
1599
1600 alloc_extra = hh_len;
1601 alloc_extra += dst_exthdrlen;
1602 alloc_extra += rt->dst.trailer_len;
1603
1604 /* We just reserve space for fragment header.
1605 * Note: this may be overallocation if the message
1606 * (without MSG_MORE) fits into the MTU.
1607 */
1608 alloc_extra += sizeof(struct frag_hdr);
1609
1610 if ((flags & MSG_MORE) &&
1611 !(rt->dst.dev->features&NETIF_F_SG))
1612 alloclen = mtu;
1613 else if (!paged &&
1614 (fraglen + alloc_extra < SKB_MAX_ALLOC ||
1615 !(rt->dst.dev->features & NETIF_F_SG)))
1616 alloclen = fraglen;
1617 else {
1618 alloclen = fragheaderlen + transhdrlen;
1619 pagedlen = datalen - transhdrlen;
1620 }
1621 alloclen += alloc_extra;
1622
1623 if (datalen != length + fraggap) {
1624 /*
1625 * this is not the last fragment, the trailer
1626 * space is regarded as data space.
1627 */
1628 datalen += rt->dst.trailer_len;
1629 }
1630
1631 fraglen = datalen + fragheaderlen;
1632
1633 copy = datalen - transhdrlen - fraggap - pagedlen;
1634 /* [!] NOTE: copy may be negative if pagedlen>0
1635 * because then the equation may reduces to -fraggap.
1636 */
1637 if (copy < 0 && !(flags & MSG_SPLICE_PAGES)) {
1638 err = -EINVAL;
1639 goto error;
1640 }
1641 if (transhdrlen) {
1642 skb = sock_alloc_send_skb(sk, alloclen,
1643 (flags & MSG_DONTWAIT), &err);
1644 } else {
1645 skb = NULL;
1646 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <=
1647 2 * sk->sk_sndbuf)
1648 skb = alloc_skb(alloclen,
1649 sk->sk_allocation);
1650 if (unlikely(!skb))
1651 err = -ENOBUFS;
1652 }
1653 if (!skb)
1654 goto error;
1655 /*
1656 * Fill in the control structures
1657 */
1658 skb->protocol = htons(ETH_P_IPV6);
1659 skb->ip_summed = csummode;
1660 skb->csum = 0;
1661 /* reserve for fragmentation and ipsec header */
1662 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
1663 dst_exthdrlen);
1664
1665 /*
1666 * Find where to start putting bytes
1667 */
1668 data = skb_put(skb, fraglen - pagedlen);
1669 skb_set_network_header(skb, exthdrlen);
1670 data += fragheaderlen;
1671 skb->transport_header = (skb->network_header +
1672 fragheaderlen);
1673 if (fraggap) {
1674 skb->csum = skb_copy_and_csum_bits(
1675 skb_prev, maxfraglen,
1676 data + transhdrlen, fraggap);
1677 skb_prev->csum = csum_sub(skb_prev->csum,
1678 skb->csum);
1679 data += fraggap;
1680 pskb_trim_unique(skb_prev, maxfraglen);
1681 }
1682 if (copy > 0 &&
1683 getfrag(from, data + transhdrlen, offset,
1684 copy, fraggap, skb) < 0) {
1685 err = -EFAULT;
1686 kfree_skb(skb);
1687 goto error;
1688 } else if (flags & MSG_SPLICE_PAGES) {
1689 copy = 0;
1690 }
1691
1692 offset += copy;
1693 length -= copy + transhdrlen;
1694 transhdrlen = 0;
1695 exthdrlen = 0;
1696 dst_exthdrlen = 0;
1697
1698 /* Only the initial fragment is time stamped */
1699 skb_shinfo(skb)->tx_flags = cork->tx_flags;
1700 cork->tx_flags = 0;
1701 skb_shinfo(skb)->tskey = tskey;
1702 tskey = 0;
1703 skb_zcopy_set(skb, uarg, &extra_uref);
1704
1705 if ((flags & MSG_CONFIRM) && !skb_prev)
1706 skb_set_dst_pending_confirm(skb, 1);
1707
1708 /*
1709 * Put the packet on the pending queue
1710 */
1711 if (!skb->destructor) {
1712 skb->destructor = sock_wfree;
1713 skb->sk = sk;
1714 wmem_alloc_delta += skb->truesize;
1715 }
1716 __skb_queue_tail(queue, skb);
1717 continue;
1718 }
1719
1720 if (copy > length)
1721 copy = length;
1722
1723 if (!(rt->dst.dev->features&NETIF_F_SG) &&
1724 skb_tailroom(skb) >= copy) {
1725 unsigned int off;
1726
1727 off = skb->len;
1728 if (getfrag(from, skb_put(skb, copy),
1729 offset, copy, off, skb) < 0) {
1730 __skb_trim(skb, off);
1731 err = -EFAULT;
1732 goto error;
1733 }
1734 } else if (flags & MSG_SPLICE_PAGES) {
1735 struct msghdr *msg = from;
1736
1737 err = -EIO;
1738 if (WARN_ON_ONCE(copy > msg->msg_iter.count))
1739 goto error;
1740
1741 err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
1742 sk->sk_allocation);
1743 if (err < 0)
1744 goto error;
1745 copy = err;
1746 wmem_alloc_delta += copy;
1747 } else if (!zc) {
1748 int i = skb_shinfo(skb)->nr_frags;
1749
1750 err = -ENOMEM;
1751 if (!sk_page_frag_refill(sk, pfrag))
1752 goto error;
1753
1754 skb_zcopy_downgrade_managed(skb);
1755 if (!skb_can_coalesce(skb, i, pfrag->page,
1756 pfrag->offset)) {
1757 err = -EMSGSIZE;
1758 if (i == MAX_SKB_FRAGS)
1759 goto error;
1760
1761 __skb_fill_page_desc(skb, i, pfrag->page,
1762 pfrag->offset, 0);
1763 skb_shinfo(skb)->nr_frags = ++i;
1764 get_page(pfrag->page);
1765 }
1766 copy = min_t(int, copy, pfrag->size - pfrag->offset);
1767 if (getfrag(from,
1768 page_address(pfrag->page) + pfrag->offset,
1769 offset, copy, skb->len, skb) < 0)
1770 goto error_efault;
1771
1772 pfrag->offset += copy;
1773 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1774 skb->len += copy;
1775 skb->data_len += copy;
1776 skb->truesize += copy;
1777 wmem_alloc_delta += copy;
1778 } else {
1779 err = skb_zerocopy_iter_dgram(skb, from, copy);
1780 if (err < 0)
1781 goto error;
1782 }
1783 offset += copy;
1784 length -= copy;
1785 }
1786
1787 if (wmem_alloc_delta)
1788 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1789 return 0;
1790
1791 error_efault:
1792 err = -EFAULT;
1793 error:
1794 net_zcopy_put_abort(uarg, extra_uref);
1795 cork->length -= length;
1796 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
1797 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);
1798 if (hold_tskey)
1799 atomic_dec(&sk->sk_tskey);
1800 return err;
1801 }
1802
1803 int ip6_append_data(struct sock *sk,
1804 int getfrag(void *from, char *to, int offset, int len,
1805 int odd, struct sk_buff *skb),
1806 void *from, size_t length, int transhdrlen,
1807 struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1808 struct rt6_info *rt, unsigned int flags)
1809 {
1810 struct inet_sock *inet = inet_sk(sk);
1811 struct ipv6_pinfo *np = inet6_sk(sk);
1812 int exthdrlen;
1813 int err;
1814
1815 if (flags&MSG_PROBE)
1816 return 0;
1817 if (skb_queue_empty(&sk->sk_write_queue)) {
1818 /*
1819 * setup for corking
1820 */
1821 dst_hold(&rt->dst);
1822 err = ip6_setup_cork(sk, &inet->cork, &np->cork,
1823 ipc6, rt);
1824 if (err)
1825 return err;
1826
1827 inet->cork.fl.u.ip6 = *fl6;
1828 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
1829 length += exthdrlen;
1830 transhdrlen += exthdrlen;
1831 } else {
1832 transhdrlen = 0;
1833 }
1834
1835 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork,
1836 &np->cork, sk_page_frag(sk), getfrag,
1837 from, length, transhdrlen, flags, ipc6);
1838 }
1839 EXPORT_SYMBOL_GPL(ip6_append_data);
1840
1841 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork)
1842 {
1843 struct dst_entry *dst = cork->base.dst;
1844
1845 cork->base.dst = NULL;
1846 skb_dst_set(skb, dst);
1847 }
1848
1849 static void ip6_cork_release(struct inet_cork_full *cork,
1850 struct inet6_cork *v6_cork)
1851 {
1852 if (v6_cork->opt) {
1853 struct ipv6_txoptions *opt = v6_cork->opt;
1854
1855 kfree(opt->dst0opt);
1856 kfree(opt->dst1opt);
1857 kfree(opt->hopopt);
1858 kfree(opt->srcrt);
1859 kfree(opt);
1860 v6_cork->opt = NULL;
1861 }
1862
1863 if (cork->base.dst) {
1864 dst_release(cork->base.dst);
1865 cork->base.dst = NULL;
1866 }
1867 }
1868
1869 struct sk_buff *__ip6_make_skb(struct sock *sk,
1870 struct sk_buff_head *queue,
1871 struct inet_cork_full *cork,
1872 struct inet6_cork *v6_cork)
1873 {
1874 struct sk_buff *skb, *tmp_skb;
1875 struct sk_buff **tail_skb;
1876 struct in6_addr *final_dst;
1877 struct net *net = sock_net(sk);
1878 struct ipv6hdr *hdr;
1879 struct ipv6_txoptions *opt = v6_cork->opt;
1880 struct rt6_info *rt = dst_rt6_info(cork->base.dst);
1881 struct flowi6 *fl6 = &cork->fl.u.ip6;
1882 unsigned char proto = fl6->flowi6_proto;
1883
1884 skb = __skb_dequeue(queue);
1885 if (!skb)
1886 goto out;
1887 tail_skb = &(skb_shinfo(skb)->frag_list);
1888
1889 /* move skb->data to ip header from ext header */
1890 if (skb->data < skb_network_header(skb))
1891 __skb_pull(skb, skb_network_offset(skb));
1892 while ((tmp_skb = __skb_dequeue(queue)) != NULL) {
1893 __skb_pull(tmp_skb, skb_network_header_len(skb));
1894 *tail_skb = tmp_skb;
1895 tail_skb = &(tmp_skb->next);
1896 skb->len += tmp_skb->len;
1897 skb->data_len += tmp_skb->len;
1898 skb->truesize += tmp_skb->truesize;
1899 tmp_skb->destructor = NULL;
1900 tmp_skb->sk = NULL;
1901 }
1902
1903 /* Allow local fragmentation. */
1904 skb->ignore_df = ip6_sk_ignore_df(sk);
1905 __skb_pull(skb, skb_network_header_len(skb));
1906
1907 final_dst = &fl6->daddr;
1908 if (opt && opt->opt_flen)
1909 ipv6_push_frag_opts(skb, opt, &proto);
1910 if (opt && opt->opt_nflen)
1911 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr);
1912
1913 skb_push(skb, sizeof(struct ipv6hdr));
1914 skb_reset_network_header(skb);
1915 hdr = ipv6_hdr(skb);
1916
1917 ip6_flow_hdr(hdr, v6_cork->tclass,
1918 ip6_make_flowlabel(net, skb, fl6->flowlabel,
1919 ip6_autoflowlabel(net, sk), fl6));
1920 hdr->hop_limit = v6_cork->hop_limit;
1921 hdr->nexthdr = proto;
1922 hdr->saddr = fl6->saddr;
1923 hdr->daddr = *final_dst;
1924
1925 skb->priority = READ_ONCE(sk->sk_priority);
1926 skb->mark = cork->base.mark;
1927 skb->tstamp = cork->base.transmit_time;
1928
1929 ip6_cork_steal_dst(skb, cork);
1930 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS);
1931 if (proto == IPPROTO_ICMPV6) {
1932 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
1933 u8 icmp6_type;
1934
1935 if (sk->sk_socket->type == SOCK_RAW &&
1936 !(fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH))
1937 icmp6_type = fl6->fl6_icmp_type;
1938 else
1939 icmp6_type = icmp6_hdr(skb)->icmp6_type;
1940 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_type);
1941 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1942 }
1943
1944 ip6_cork_release(cork, v6_cork);
1945 out:
1946 return skb;
1947 }
1948
1949 int ip6_send_skb(struct sk_buff *skb)
1950 {
1951 struct net *net = sock_net(skb->sk);
1952 struct rt6_info *rt = dst_rt6_info(skb_dst(skb));
1953 int err;
1954
1955 err = ip6_local_out(net, skb->sk, skb);
1956 if (err) {
1957 if (err > 0)
1958 err = net_xmit_errno(err);
1959 if (err)
1960 IP6_INC_STATS(net, rt->rt6i_idev,
1961 IPSTATS_MIB_OUTDISCARDS);
1962 }
1963
1964 return err;
1965 }
1966
1967 int ip6_push_pending_frames(struct sock *sk)
1968 {
1969 struct sk_buff *skb;
1970
1971 skb = ip6_finish_skb(sk);
1972 if (!skb)
1973 return 0;
1974
1975 return ip6_send_skb(skb);
1976 }
1977 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
1978
1979 static void __ip6_flush_pending_frames(struct sock *sk,
1980 struct sk_buff_head *queue,
1981 struct inet_cork_full *cork,
1982 struct inet6_cork *v6_cork)
1983 {
1984 struct sk_buff *skb;
1985
1986 while ((skb = __skb_dequeue_tail(queue)) != NULL) {
1987 if (skb_dst(skb))
1988 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
1989 IPSTATS_MIB_OUTDISCARDS);
1990 kfree_skb(skb);
1991 }
1992
1993 ip6_cork_release(cork, v6_cork);
1994 }
1995
1996 void ip6_flush_pending_frames(struct sock *sk)
1997 {
1998 __ip6_flush_pending_frames(sk, &sk->sk_write_queue,
1999 &inet_sk(sk)->cork, &inet6_sk(sk)->cork);
2000 }
2001 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
2002
2003 struct sk_buff *ip6_make_skb(struct sock *sk,
2004 int getfrag(void *from, char *to, int offset,
2005 int len, int odd, struct sk_buff *skb),
2006 void *from, size_t length, int transhdrlen,
2007 struct ipcm6_cookie *ipc6, struct rt6_info *rt,
2008 unsigned int flags, struct inet_cork_full *cork)
2009 {
2010 struct inet6_cork v6_cork;
2011 struct sk_buff_head queue;
2012 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
2013 int err;
2014
2015 if (flags & MSG_PROBE) {
2016 dst_release(&rt->dst);
2017 return NULL;
2018 }
2019
2020 __skb_queue_head_init(&queue);
2021
2022 cork->base.flags = 0;
2023 cork->base.addr = 0;
2024 cork->base.opt = NULL;
2025 v6_cork.opt = NULL;
2026 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt);
2027 if (err) {
2028 ip6_cork_release(cork, &v6_cork);
2029 return ERR_PTR(err);
2030 }
2031 if (ipc6->dontfrag < 0)
2032 ipc6->dontfrag = inet6_test_bit(DONTFRAG, sk);
2033
2034 err = __ip6_append_data(sk, &queue, cork, &v6_cork,
2035 &current->task_frag, getfrag, from,
2036 length + exthdrlen, transhdrlen + exthdrlen,
2037 flags, ipc6);
2038 if (err) {
2039 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork);
2040 return ERR_PTR(err);
2041 }
2042
2043 return __ip6_make_skb(sk, &queue, cork, &v6_cork);
2044 }
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git