2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/compiler.h>
19 #include <linux/time.h>
20 #include <linux/cache.h>
22 #include <asm/atomic.h>
23 #include <asm/types.h>
24 #include <linux/spinlock.h>
25 #include <linux/net.h>
26 #include <linux/textsearch.h>
27 #include <net/checksum.h>
28 #include <linux/rcupdate.h>
29 #include <linux/dmaengine.h>
30 #include <linux/hrtimer.h>
32 /* Don't change this without changing skb_csum_unnecessary! */
33 #define CHECKSUM_NONE 0
34 #define CHECKSUM_UNNECESSARY 1
35 #define CHECKSUM_COMPLETE 2
36 #define CHECKSUM_PARTIAL 3
38 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
39 ~(SMP_CACHE_BYTES - 1))
40 #define SKB_WITH_OVERHEAD(X) \
41 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
42 #define SKB_MAX_ORDER(X, ORDER) \
43 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
44 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
45 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
47 /* A. Checksumming of received packets by device.
49 * NONE: device failed to checksum this packet.
50 * skb->csum is undefined.
52 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
53 * skb->csum is undefined.
54 * It is bad option, but, unfortunately, many of vendors do this.
55 * Apparently with secret goal to sell you new device, when you
56 * will add new protocol to your host. F.e. IPv6. 8)
58 * COMPLETE: the most generic way. Device supplied checksum of _all_
59 * the packet as seen by netif_rx in skb->csum.
60 * NOTE: Even if device supports only some protocols, but
61 * is able to produce some skb->csum, it MUST use COMPLETE,
64 * PARTIAL: identical to the case for output below. This may occur
65 * on a packet received directly from another Linux OS, e.g.,
66 * a virtualised Linux kernel on the same host. The packet can
67 * be treated in the same way as UNNECESSARY except that on
68 * output (i.e., forwarding) the checksum must be filled in
69 * by the OS or the hardware.
71 * B. Checksumming on output.
73 * NONE: skb is checksummed by protocol or csum is not required.
75 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
76 * from skb->csum_start to the end and to record the checksum
77 * at skb->csum_start + skb->csum_offset.
79 * Device must show its capabilities in dev->features, set
80 * at device setup time.
81 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
83 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
84 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
85 * TCP/UDP over IPv4. Sigh. Vendors like this
86 * way by an unknown reason. Though, see comment above
87 * about CHECKSUM_UNNECESSARY. 8)
88 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
90 * Any questions? No questions, good. --ANK
95 struct pipe_inode_info
;
97 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
103 #ifdef CONFIG_BRIDGE_NETFILTER
104 struct nf_bridge_info
{
106 struct net_device
*physindev
;
107 struct net_device
*physoutdev
;
109 unsigned long data
[32 / sizeof(unsigned long)];
113 struct sk_buff_head
{
114 /* These two members must be first. */
115 struct sk_buff
*next
;
116 struct sk_buff
*prev
;
124 /* To allow 64K frame to be packed as single skb without frag_list */
125 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
127 typedef struct skb_frag_struct skb_frag_t
;
129 struct skb_frag_struct
{
135 #define HAVE_HW_TIME_STAMP
138 * skb_shared_hwtstamps - hardware time stamps
140 * @hwtstamp: hardware time stamp transformed into duration
141 * since arbitrary point in time
142 * @syststamp: hwtstamp transformed to system time base
144 * Software time stamps generated by ktime_get_real() are stored in
145 * skb->tstamp. The relation between the different kinds of time
146 * stamps is as follows:
148 * syststamp and tstamp can be compared against each other in
149 * arbitrary combinations. The accuracy of a
150 * syststamp/tstamp/"syststamp from other device" comparison is
151 * limited by the accuracy of the transformation into system time
152 * base. This depends on the device driver and its underlying
155 * hwtstamps can only be compared against other hwtstamps from
158 * This structure is attached to packets as part of the
159 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
161 struct skb_shared_hwtstamps
{
167 * skb_shared_tx - instructions for time stamping of outgoing packets
169 * @hardware: generate hardware time stamp
170 * @software: generate software time stamp
171 * @in_progress: device driver is going to provide
172 * hardware time stamp
174 * These flags are attached to packets as part of the
175 * &skb_shared_info. Use skb_tx() to get a pointer.
177 union skb_shared_tx
{
186 /* This data is invariant across clones and lives at
187 * the end of the header data, ie. at skb->end.
189 struct skb_shared_info
{
191 unsigned short nr_frags
;
192 unsigned short gso_size
;
193 /* Warning: this field is not always filled in (UFO)! */
194 unsigned short gso_segs
;
195 unsigned short gso_type
;
197 union skb_shared_tx tx_flags
;
198 #ifdef CONFIG_HAS_DMA
199 unsigned int num_dma_maps
;
201 struct sk_buff
*frag_list
;
202 struct skb_shared_hwtstamps hwtstamps
;
203 skb_frag_t frags
[MAX_SKB_FRAGS
];
204 #ifdef CONFIG_HAS_DMA
205 dma_addr_t dma_maps
[MAX_SKB_FRAGS
+ 1];
209 /* We divide dataref into two halves. The higher 16 bits hold references
210 * to the payload part of skb->data. The lower 16 bits hold references to
211 * the entire skb->data. A clone of a headerless skb holds the length of
212 * the header in skb->hdr_len.
214 * All users must obey the rule that the skb->data reference count must be
215 * greater than or equal to the payload reference count.
217 * Holding a reference to the payload part means that the user does not
218 * care about modifications to the header part of skb->data.
220 #define SKB_DATAREF_SHIFT 16
221 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
225 SKB_FCLONE_UNAVAILABLE
,
231 SKB_GSO_TCPV4
= 1 << 0,
232 SKB_GSO_UDP
= 1 << 1,
234 /* This indicates the skb is from an untrusted source. */
235 SKB_GSO_DODGY
= 1 << 2,
237 /* This indicates the tcp segment has CWR set. */
238 SKB_GSO_TCP_ECN
= 1 << 3,
240 SKB_GSO_TCPV6
= 1 << 4,
243 #if BITS_PER_LONG > 32
244 #define NET_SKBUFF_DATA_USES_OFFSET 1
247 #ifdef NET_SKBUFF_DATA_USES_OFFSET
248 typedef unsigned int sk_buff_data_t
;
250 typedef unsigned char *sk_buff_data_t
;
254 * struct sk_buff - socket buffer
255 * @next: Next buffer in list
256 * @prev: Previous buffer in list
257 * @sk: Socket we are owned by
258 * @tstamp: Time we arrived
259 * @dev: Device we arrived on/are leaving by
260 * @transport_header: Transport layer header
261 * @network_header: Network layer header
262 * @mac_header: Link layer header
263 * @dst: destination entry
264 * @sp: the security path, used for xfrm
265 * @cb: Control buffer. Free for use by every layer. Put private vars here
266 * @len: Length of actual data
267 * @data_len: Data length
268 * @mac_len: Length of link layer header
269 * @hdr_len: writable header length of cloned skb
270 * @csum: Checksum (must include start/offset pair)
271 * @csum_start: Offset from skb->head where checksumming should start
272 * @csum_offset: Offset from csum_start where checksum should be stored
273 * @local_df: allow local fragmentation
274 * @cloned: Head may be cloned (check refcnt to be sure)
275 * @nohdr: Payload reference only, must not modify header
276 * @pkt_type: Packet class
277 * @fclone: skbuff clone status
278 * @ip_summed: Driver fed us an IP checksum
279 * @priority: Packet queueing priority
280 * @users: User count - see {datagram,tcp}.c
281 * @protocol: Packet protocol from driver
282 * @truesize: Buffer size
283 * @head: Head of buffer
284 * @data: Data head pointer
285 * @tail: Tail pointer
287 * @destructor: Destruct function
288 * @mark: Generic packet mark
289 * @nfct: Associated connection, if any
290 * @ipvs_property: skbuff is owned by ipvs
291 * @peeked: this packet has been seen already, so stats have been
292 * done for it, don't do them again
293 * @nf_trace: netfilter packet trace flag
294 * @nfctinfo: Relationship of this skb to the connection
295 * @nfct_reasm: netfilter conntrack re-assembly pointer
296 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
297 * @iif: ifindex of device we arrived on
298 * @queue_mapping: Queue mapping for multiqueue devices
299 * @tc_index: Traffic control index
300 * @tc_verd: traffic control verdict
301 * @ndisc_nodetype: router type (from link layer)
302 * @do_not_encrypt: set to prevent encryption of this frame
303 * @requeue: set to indicate that the wireless core should attempt
304 * a software retry on this frame if we failed to
305 * receive an ACK for it
306 * @dma_cookie: a cookie to one of several possible DMA operations
307 * done by skb DMA functions
308 * @secmark: security marking
309 * @vlan_tci: vlan tag control information
313 /* These two members must be first. */
314 struct sk_buff
*next
;
315 struct sk_buff
*prev
;
319 struct net_device
*dev
;
322 struct dst_entry
*dst
;
323 struct rtable
*rtable
;
329 * This is the control buffer. It is free to use for every
330 * layer. Please put your private variables there. If you
331 * want to keep them across layers you have to do a skb_clone()
332 * first. This is owned by whoever has the skb queued ATM.
360 void (*destructor
)(struct sk_buff
*skb
);
361 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
362 struct nf_conntrack
*nfct
;
363 struct sk_buff
*nfct_reasm
;
365 #ifdef CONFIG_BRIDGE_NETFILTER
366 struct nf_bridge_info
*nf_bridge
;
371 #ifdef CONFIG_NET_SCHED
372 __u16 tc_index
; /* traffic control index */
373 #ifdef CONFIG_NET_CLS_ACT
374 __u16 tc_verd
; /* traffic control verdict */
377 #ifdef CONFIG_IPV6_NDISC_NODETYPE
378 __u8 ndisc_nodetype
:2;
380 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
381 __u8 do_not_encrypt
:1;
384 /* 0/13/14 bit hole */
386 #ifdef CONFIG_NET_DMA
387 dma_cookie_t dma_cookie
;
389 #ifdef CONFIG_NETWORK_SECMARK
397 sk_buff_data_t transport_header
;
398 sk_buff_data_t network_header
;
399 sk_buff_data_t mac_header
;
400 /* These elements must be at the end, see alloc_skb() for details. */
405 unsigned int truesize
;
411 * Handling routines are only of interest to the kernel
413 #include <linux/slab.h>
415 #include <asm/system.h>
417 #ifdef CONFIG_HAS_DMA
418 #include <linux/dma-mapping.h>
419 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
420 enum dma_data_direction dir
);
421 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
422 enum dma_data_direction dir
);
425 extern void kfree_skb(struct sk_buff
*skb
);
426 extern void __kfree_skb(struct sk_buff
*skb
);
427 extern struct sk_buff
*__alloc_skb(unsigned int size
,
428 gfp_t priority
, int fclone
, int node
);
429 static inline struct sk_buff
*alloc_skb(unsigned int size
,
432 return __alloc_skb(size
, priority
, 0, -1);
435 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
438 return __alloc_skb(size
, priority
, 1, -1);
441 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
443 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
444 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
446 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
448 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
450 extern int pskb_expand_head(struct sk_buff
*skb
,
451 int nhead
, int ntail
,
453 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
454 unsigned int headroom
);
455 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
456 int newheadroom
, int newtailroom
,
458 extern int skb_to_sgvec(struct sk_buff
*skb
,
459 struct scatterlist
*sg
, int offset
,
461 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
462 struct sk_buff
**trailer
);
463 extern int skb_pad(struct sk_buff
*skb
, int pad
);
464 #define dev_kfree_skb(a) kfree_skb(a)
465 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
467 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
469 extern void skb_truesize_bug(struct sk_buff
*skb
);
471 static inline void skb_truesize_check(struct sk_buff
*skb
)
473 int len
= sizeof(struct sk_buff
) + skb
->len
;
475 if (unlikely((int)skb
->truesize
< len
))
476 skb_truesize_bug(skb
);
479 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
480 int getfrag(void *from
, char *to
, int offset
,
481 int len
,int odd
, struct sk_buff
*skb
),
482 void *from
, int length
);
489 __u32 stepped_offset
;
490 struct sk_buff
*root_skb
;
491 struct sk_buff
*cur_skb
;
495 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
496 unsigned int from
, unsigned int to
,
497 struct skb_seq_state
*st
);
498 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
499 struct skb_seq_state
*st
);
500 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
502 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
503 unsigned int to
, struct ts_config
*config
,
504 struct ts_state
*state
);
506 #ifdef NET_SKBUFF_DATA_USES_OFFSET
507 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
509 return skb
->head
+ skb
->end
;
512 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
519 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
521 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
523 return &skb_shinfo(skb
)->hwtstamps
;
526 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
528 return &skb_shinfo(skb
)->tx_flags
;
532 * skb_queue_empty - check if a queue is empty
535 * Returns true if the queue is empty, false otherwise.
537 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
539 return list
->next
== (struct sk_buff
*)list
;
543 * skb_queue_is_last - check if skb is the last entry in the queue
547 * Returns true if @skb is the last buffer on the list.
549 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
550 const struct sk_buff
*skb
)
552 return (skb
->next
== (struct sk_buff
*) list
);
556 * skb_queue_is_first - check if skb is the first entry in the queue
560 * Returns true if @skb is the first buffer on the list.
562 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
563 const struct sk_buff
*skb
)
565 return (skb
->prev
== (struct sk_buff
*) list
);
569 * skb_queue_next - return the next packet in the queue
571 * @skb: current buffer
573 * Return the next packet in @list after @skb. It is only valid to
574 * call this if skb_queue_is_last() evaluates to false.
576 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
577 const struct sk_buff
*skb
)
579 /* This BUG_ON may seem severe, but if we just return then we
580 * are going to dereference garbage.
582 BUG_ON(skb_queue_is_last(list
, skb
));
587 * skb_queue_prev - return the prev packet in the queue
589 * @skb: current buffer
591 * Return the prev packet in @list before @skb. It is only valid to
592 * call this if skb_queue_is_first() evaluates to false.
594 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
595 const struct sk_buff
*skb
)
597 /* This BUG_ON may seem severe, but if we just return then we
598 * are going to dereference garbage.
600 BUG_ON(skb_queue_is_first(list
, skb
));
605 * skb_get - reference buffer
606 * @skb: buffer to reference
608 * Makes another reference to a socket buffer and returns a pointer
611 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
613 atomic_inc(&skb
->users
);
618 * If users == 1, we are the only owner and are can avoid redundant
623 * skb_cloned - is the buffer a clone
624 * @skb: buffer to check
626 * Returns true if the buffer was generated with skb_clone() and is
627 * one of multiple shared copies of the buffer. Cloned buffers are
628 * shared data so must not be written to under normal circumstances.
630 static inline int skb_cloned(const struct sk_buff
*skb
)
632 return skb
->cloned
&&
633 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
637 * skb_header_cloned - is the header a clone
638 * @skb: buffer to check
640 * Returns true if modifying the header part of the buffer requires
641 * the data to be copied.
643 static inline int skb_header_cloned(const struct sk_buff
*skb
)
650 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
651 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
656 * skb_header_release - release reference to header
657 * @skb: buffer to operate on
659 * Drop a reference to the header part of the buffer. This is done
660 * by acquiring a payload reference. You must not read from the header
661 * part of skb->data after this.
663 static inline void skb_header_release(struct sk_buff
*skb
)
667 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
671 * skb_shared - is the buffer shared
672 * @skb: buffer to check
674 * Returns true if more than one person has a reference to this
677 static inline int skb_shared(const struct sk_buff
*skb
)
679 return atomic_read(&skb
->users
) != 1;
683 * skb_share_check - check if buffer is shared and if so clone it
684 * @skb: buffer to check
685 * @pri: priority for memory allocation
687 * If the buffer is shared the buffer is cloned and the old copy
688 * drops a reference. A new clone with a single reference is returned.
689 * If the buffer is not shared the original buffer is returned. When
690 * being called from interrupt status or with spinlocks held pri must
693 * NULL is returned on a memory allocation failure.
695 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
698 might_sleep_if(pri
& __GFP_WAIT
);
699 if (skb_shared(skb
)) {
700 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
708 * Copy shared buffers into a new sk_buff. We effectively do COW on
709 * packets to handle cases where we have a local reader and forward
710 * and a couple of other messy ones. The normal one is tcpdumping
711 * a packet thats being forwarded.
715 * skb_unshare - make a copy of a shared buffer
716 * @skb: buffer to check
717 * @pri: priority for memory allocation
719 * If the socket buffer is a clone then this function creates a new
720 * copy of the data, drops a reference count on the old copy and returns
721 * the new copy with the reference count at 1. If the buffer is not a clone
722 * the original buffer is returned. When called with a spinlock held or
723 * from interrupt state @pri must be %GFP_ATOMIC
725 * %NULL is returned on a memory allocation failure.
727 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
730 might_sleep_if(pri
& __GFP_WAIT
);
731 if (skb_cloned(skb
)) {
732 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
733 kfree_skb(skb
); /* Free our shared copy */
741 * @list_: list to peek at
743 * Peek an &sk_buff. Unlike most other operations you _MUST_
744 * be careful with this one. A peek leaves the buffer on the
745 * list and someone else may run off with it. You must hold
746 * the appropriate locks or have a private queue to do this.
748 * Returns %NULL for an empty list or a pointer to the head element.
749 * The reference count is not incremented and the reference is therefore
750 * volatile. Use with caution.
752 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
754 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
755 if (list
== (struct sk_buff
*)list_
)
762 * @list_: list to peek at
764 * Peek an &sk_buff. Unlike most other operations you _MUST_
765 * be careful with this one. A peek leaves the buffer on the
766 * list and someone else may run off with it. You must hold
767 * the appropriate locks or have a private queue to do this.
769 * Returns %NULL for an empty list or a pointer to the tail element.
770 * The reference count is not incremented and the reference is therefore
771 * volatile. Use with caution.
773 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
775 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
776 if (list
== (struct sk_buff
*)list_
)
782 * skb_queue_len - get queue length
783 * @list_: list to measure
785 * Return the length of an &sk_buff queue.
787 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
793 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
794 * @list: queue to initialize
796 * This initializes only the list and queue length aspects of
797 * an sk_buff_head object. This allows to initialize the list
798 * aspects of an sk_buff_head without reinitializing things like
799 * the spinlock. It can also be used for on-stack sk_buff_head
800 * objects where the spinlock is known to not be used.
802 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
804 list
->prev
= list
->next
= (struct sk_buff
*)list
;
809 * This function creates a split out lock class for each invocation;
810 * this is needed for now since a whole lot of users of the skb-queue
811 * infrastructure in drivers have different locking usage (in hardirq)
812 * than the networking core (in softirq only). In the long run either the
813 * network layer or drivers should need annotation to consolidate the
814 * main types of usage into 3 classes.
816 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
818 spin_lock_init(&list
->lock
);
819 __skb_queue_head_init(list
);
822 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
823 struct lock_class_key
*class)
825 skb_queue_head_init(list
);
826 lockdep_set_class(&list
->lock
, class);
830 * Insert an sk_buff on a list.
832 * The "__skb_xxxx()" functions are the non-atomic ones that
833 * can only be called with interrupts disabled.
835 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
836 static inline void __skb_insert(struct sk_buff
*newsk
,
837 struct sk_buff
*prev
, struct sk_buff
*next
,
838 struct sk_buff_head
*list
)
842 next
->prev
= prev
->next
= newsk
;
846 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
847 struct sk_buff
*prev
,
848 struct sk_buff
*next
)
850 struct sk_buff
*first
= list
->next
;
851 struct sk_buff
*last
= list
->prev
;
861 * skb_queue_splice - join two skb lists, this is designed for stacks
862 * @list: the new list to add
863 * @head: the place to add it in the first list
865 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
866 struct sk_buff_head
*head
)
868 if (!skb_queue_empty(list
)) {
869 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
870 head
->qlen
+= list
->qlen
;
875 * skb_queue_splice - join two skb lists and reinitialise the emptied list
876 * @list: the new list to add
877 * @head: the place to add it in the first list
879 * The list at @list is reinitialised
881 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
882 struct sk_buff_head
*head
)
884 if (!skb_queue_empty(list
)) {
885 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
886 head
->qlen
+= list
->qlen
;
887 __skb_queue_head_init(list
);
892 * skb_queue_splice_tail - join two skb lists, each list being a queue
893 * @list: the new list to add
894 * @head: the place to add it in the first list
896 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
897 struct sk_buff_head
*head
)
899 if (!skb_queue_empty(list
)) {
900 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
901 head
->qlen
+= list
->qlen
;
906 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
907 * @list: the new list to add
908 * @head: the place to add it in the first list
910 * Each of the lists is a queue.
911 * The list at @list is reinitialised
913 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
914 struct sk_buff_head
*head
)
916 if (!skb_queue_empty(list
)) {
917 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
918 head
->qlen
+= list
->qlen
;
919 __skb_queue_head_init(list
);
924 * __skb_queue_after - queue a buffer at the list head
926 * @prev: place after this buffer
927 * @newsk: buffer to queue
929 * Queue a buffer int the middle of a list. This function takes no locks
930 * and you must therefore hold required locks before calling it.
932 * A buffer cannot be placed on two lists at the same time.
934 static inline void __skb_queue_after(struct sk_buff_head
*list
,
935 struct sk_buff
*prev
,
936 struct sk_buff
*newsk
)
938 __skb_insert(newsk
, prev
, prev
->next
, list
);
941 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
942 struct sk_buff_head
*list
);
944 static inline void __skb_queue_before(struct sk_buff_head
*list
,
945 struct sk_buff
*next
,
946 struct sk_buff
*newsk
)
948 __skb_insert(newsk
, next
->prev
, next
, list
);
952 * __skb_queue_head - queue a buffer at the list head
954 * @newsk: buffer to queue
956 * Queue a buffer at the start of a list. This function takes no locks
957 * and you must therefore hold required locks before calling it.
959 * A buffer cannot be placed on two lists at the same time.
961 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
962 static inline void __skb_queue_head(struct sk_buff_head
*list
,
963 struct sk_buff
*newsk
)
965 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
969 * __skb_queue_tail - queue a buffer at the list tail
971 * @newsk: buffer to queue
973 * Queue a buffer at the end of a list. This function takes no locks
974 * and you must therefore hold required locks before calling it.
976 * A buffer cannot be placed on two lists at the same time.
978 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
979 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
980 struct sk_buff
*newsk
)
982 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
986 * remove sk_buff from list. _Must_ be called atomically, and with
989 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
990 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
992 struct sk_buff
*next
, *prev
;
997 skb
->next
= skb
->prev
= NULL
;
1003 * __skb_dequeue - remove from the head of the queue
1004 * @list: list to dequeue from
1006 * Remove the head of the list. This function does not take any locks
1007 * so must be used with appropriate locks held only. The head item is
1008 * returned or %NULL if the list is empty.
1010 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1011 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1013 struct sk_buff
*skb
= skb_peek(list
);
1015 __skb_unlink(skb
, list
);
1020 * __skb_dequeue_tail - remove from the tail of the queue
1021 * @list: list to dequeue from
1023 * Remove the tail of the list. This function does not take any locks
1024 * so must be used with appropriate locks held only. The tail item is
1025 * returned or %NULL if the list is empty.
1027 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1028 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1030 struct sk_buff
*skb
= skb_peek_tail(list
);
1032 __skb_unlink(skb
, list
);
1037 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1039 return skb
->data_len
;
1042 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1044 return skb
->len
- skb
->data_len
;
1047 static inline int skb_pagelen(const struct sk_buff
*skb
)
1051 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1052 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1053 return len
+ skb_headlen(skb
);
1056 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1057 struct page
*page
, int off
, int size
)
1059 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1062 frag
->page_offset
= off
;
1064 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1067 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1070 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1071 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1072 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1074 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1075 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1077 return skb
->head
+ skb
->tail
;
1080 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1082 skb
->tail
= skb
->data
- skb
->head
;
1085 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1087 skb_reset_tail_pointer(skb
);
1088 skb
->tail
+= offset
;
1090 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1091 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1096 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1098 skb
->tail
= skb
->data
;
1101 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1103 skb
->tail
= skb
->data
+ offset
;
1106 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1109 * Add data to an sk_buff
1111 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1112 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1114 unsigned char *tmp
= skb_tail_pointer(skb
);
1115 SKB_LINEAR_ASSERT(skb
);
1121 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1122 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1129 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1130 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1133 BUG_ON(skb
->len
< skb
->data_len
);
1134 return skb
->data
+= len
;
1137 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1139 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1141 if (len
> skb_headlen(skb
) &&
1142 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1145 return skb
->data
+= len
;
1148 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1150 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1153 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1155 if (likely(len
<= skb_headlen(skb
)))
1157 if (unlikely(len
> skb
->len
))
1159 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1163 * skb_headroom - bytes at buffer head
1164 * @skb: buffer to check
1166 * Return the number of bytes of free space at the head of an &sk_buff.
1168 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1170 return skb
->data
- skb
->head
;
1174 * skb_tailroom - bytes at buffer end
1175 * @skb: buffer to check
1177 * Return the number of bytes of free space at the tail of an sk_buff
1179 static inline int skb_tailroom(const struct sk_buff
*skb
)
1181 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1185 * skb_reserve - adjust headroom
1186 * @skb: buffer to alter
1187 * @len: bytes to move
1189 * Increase the headroom of an empty &sk_buff by reducing the tail
1190 * room. This is only allowed for an empty buffer.
1192 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1198 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1199 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1201 return skb
->head
+ skb
->transport_header
;
1204 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1206 skb
->transport_header
= skb
->data
- skb
->head
;
1209 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1212 skb_reset_transport_header(skb
);
1213 skb
->transport_header
+= offset
;
1216 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1218 return skb
->head
+ skb
->network_header
;
1221 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1223 skb
->network_header
= skb
->data
- skb
->head
;
1226 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1228 skb_reset_network_header(skb
);
1229 skb
->network_header
+= offset
;
1232 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1234 return skb
->head
+ skb
->mac_header
;
1237 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1239 return skb
->mac_header
!= ~0U;
1242 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1244 skb
->mac_header
= skb
->data
- skb
->head
;
1247 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1249 skb_reset_mac_header(skb
);
1250 skb
->mac_header
+= offset
;
1253 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1255 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1257 return skb
->transport_header
;
1260 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1262 skb
->transport_header
= skb
->data
;
1265 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1268 skb
->transport_header
= skb
->data
+ offset
;
1271 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1273 return skb
->network_header
;
1276 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1278 skb
->network_header
= skb
->data
;
1281 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1283 skb
->network_header
= skb
->data
+ offset
;
1286 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1288 return skb
->mac_header
;
1291 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1293 return skb
->mac_header
!= NULL
;
1296 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1298 skb
->mac_header
= skb
->data
;
1301 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1303 skb
->mac_header
= skb
->data
+ offset
;
1305 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1307 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1309 return skb_transport_header(skb
) - skb
->data
;
1312 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1314 return skb
->transport_header
- skb
->network_header
;
1317 static inline int skb_network_offset(const struct sk_buff
*skb
)
1319 return skb_network_header(skb
) - skb
->data
;
1323 * CPUs often take a performance hit when accessing unaligned memory
1324 * locations. The actual performance hit varies, it can be small if the
1325 * hardware handles it or large if we have to take an exception and fix it
1328 * Since an ethernet header is 14 bytes network drivers often end up with
1329 * the IP header at an unaligned offset. The IP header can be aligned by
1330 * shifting the start of the packet by 2 bytes. Drivers should do this
1333 * skb_reserve(NET_IP_ALIGN);
1335 * The downside to this alignment of the IP header is that the DMA is now
1336 * unaligned. On some architectures the cost of an unaligned DMA is high
1337 * and this cost outweighs the gains made by aligning the IP header.
1339 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1342 #ifndef NET_IP_ALIGN
1343 #define NET_IP_ALIGN 2
1347 * The networking layer reserves some headroom in skb data (via
1348 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1349 * the header has to grow. In the default case, if the header has to grow
1350 * 32 bytes or less we avoid the reallocation.
1352 * Unfortunately this headroom changes the DMA alignment of the resulting
1353 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1354 * on some architectures. An architecture can override this value,
1355 * perhaps setting it to a cacheline in size (since that will maintain
1356 * cacheline alignment of the DMA). It must be a power of 2.
1358 * Various parts of the networking layer expect at least 32 bytes of
1359 * headroom, you should not reduce this.
1362 #define NET_SKB_PAD 32
1365 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1367 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1369 if (unlikely(skb
->data_len
)) {
1374 skb_set_tail_pointer(skb
, len
);
1377 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1379 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1382 return ___pskb_trim(skb
, len
);
1383 __skb_trim(skb
, len
);
1387 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1389 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1393 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1394 * @skb: buffer to alter
1397 * This is identical to pskb_trim except that the caller knows that
1398 * the skb is not cloned so we should never get an error due to out-
1401 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1403 int err
= pskb_trim(skb
, len
);
1408 * skb_orphan - orphan a buffer
1409 * @skb: buffer to orphan
1411 * If a buffer currently has an owner then we call the owner's
1412 * destructor function and make the @skb unowned. The buffer continues
1413 * to exist but is no longer charged to its former owner.
1415 static inline void skb_orphan(struct sk_buff
*skb
)
1417 if (skb
->destructor
)
1418 skb
->destructor(skb
);
1419 skb
->destructor
= NULL
;
1424 * __skb_queue_purge - empty a list
1425 * @list: list to empty
1427 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1428 * the list and one reference dropped. This function does not take the
1429 * list lock and the caller must hold the relevant locks to use it.
1431 extern void skb_queue_purge(struct sk_buff_head
*list
);
1432 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1434 struct sk_buff
*skb
;
1435 while ((skb
= __skb_dequeue(list
)) != NULL
)
1440 * __dev_alloc_skb - allocate an skbuff for receiving
1441 * @length: length to allocate
1442 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1444 * Allocate a new &sk_buff and assign it a usage count of one. The
1445 * buffer has unspecified headroom built in. Users should allocate
1446 * the headroom they think they need without accounting for the
1447 * built in space. The built in space is used for optimisations.
1449 * %NULL is returned if there is no free memory.
1451 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1454 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1456 skb_reserve(skb
, NET_SKB_PAD
);
1460 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1462 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1463 unsigned int length
, gfp_t gfp_mask
);
1466 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1467 * @dev: network device to receive on
1468 * @length: length to allocate
1470 * Allocate a new &sk_buff and assign it a usage count of one. The
1471 * buffer has unspecified headroom built in. Users should allocate
1472 * the headroom they think they need without accounting for the
1473 * built in space. The built in space is used for optimisations.
1475 * %NULL is returned if there is no free memory. Although this function
1476 * allocates memory it can be called from an interrupt.
1478 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1479 unsigned int length
)
1481 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1484 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1487 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1488 * @dev: network device to receive on
1490 * Allocate a new page node local to the specified device.
1492 * %NULL is returned if there is no free memory.
1494 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1496 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1499 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1505 * skb_clone_writable - is the header of a clone writable
1506 * @skb: buffer to check
1507 * @len: length up to which to write
1509 * Returns true if modifying the header part of the cloned buffer
1510 * does not requires the data to be copied.
1512 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1514 return !skb_header_cloned(skb
) &&
1515 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1518 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1523 if (headroom
< NET_SKB_PAD
)
1524 headroom
= NET_SKB_PAD
;
1525 if (headroom
> skb_headroom(skb
))
1526 delta
= headroom
- skb_headroom(skb
);
1528 if (delta
|| cloned
)
1529 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1535 * skb_cow - copy header of skb when it is required
1536 * @skb: buffer to cow
1537 * @headroom: needed headroom
1539 * If the skb passed lacks sufficient headroom or its data part
1540 * is shared, data is reallocated. If reallocation fails, an error
1541 * is returned and original skb is not changed.
1543 * The result is skb with writable area skb->head...skb->tail
1544 * and at least @headroom of space at head.
1546 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1548 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1552 * skb_cow_head - skb_cow but only making the head writable
1553 * @skb: buffer to cow
1554 * @headroom: needed headroom
1556 * This function is identical to skb_cow except that we replace the
1557 * skb_cloned check by skb_header_cloned. It should be used when
1558 * you only need to push on some header and do not need to modify
1561 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1563 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1567 * skb_padto - pad an skbuff up to a minimal size
1568 * @skb: buffer to pad
1569 * @len: minimal length
1571 * Pads up a buffer to ensure the trailing bytes exist and are
1572 * blanked. If the buffer already contains sufficient data it
1573 * is untouched. Otherwise it is extended. Returns zero on
1574 * success. The skb is freed on error.
1577 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1579 unsigned int size
= skb
->len
;
1580 if (likely(size
>= len
))
1582 return skb_pad(skb
, len
- size
);
1585 static inline int skb_add_data(struct sk_buff
*skb
,
1586 char __user
*from
, int copy
)
1588 const int off
= skb
->len
;
1590 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1592 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1595 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1598 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1601 __skb_trim(skb
, off
);
1605 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1606 struct page
*page
, int off
)
1609 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1611 return page
== frag
->page
&&
1612 off
== frag
->page_offset
+ frag
->size
;
1617 static inline int __skb_linearize(struct sk_buff
*skb
)
1619 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1623 * skb_linearize - convert paged skb to linear one
1624 * @skb: buffer to linarize
1626 * If there is no free memory -ENOMEM is returned, otherwise zero
1627 * is returned and the old skb data released.
1629 static inline int skb_linearize(struct sk_buff
*skb
)
1631 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1635 * skb_linearize_cow - make sure skb is linear and writable
1636 * @skb: buffer to process
1638 * If there is no free memory -ENOMEM is returned, otherwise zero
1639 * is returned and the old skb data released.
1641 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1643 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1644 __skb_linearize(skb
) : 0;
1648 * skb_postpull_rcsum - update checksum for received skb after pull
1649 * @skb: buffer to update
1650 * @start: start of data before pull
1651 * @len: length of data pulled
1653 * After doing a pull on a received packet, you need to call this to
1654 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1655 * CHECKSUM_NONE so that it can be recomputed from scratch.
1658 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1659 const void *start
, unsigned int len
)
1661 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1662 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1665 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1668 * pskb_trim_rcsum - trim received skb and update checksum
1669 * @skb: buffer to trim
1672 * This is exactly the same as pskb_trim except that it ensures the
1673 * checksum of received packets are still valid after the operation.
1676 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1678 if (likely(len
>= skb
->len
))
1680 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1681 skb
->ip_summed
= CHECKSUM_NONE
;
1682 return __pskb_trim(skb
, len
);
1685 #define skb_queue_walk(queue, skb) \
1686 for (skb = (queue)->next; \
1687 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1690 #define skb_queue_walk_safe(queue, skb, tmp) \
1691 for (skb = (queue)->next, tmp = skb->next; \
1692 skb != (struct sk_buff *)(queue); \
1693 skb = tmp, tmp = skb->next)
1695 #define skb_queue_walk_from(queue, skb) \
1696 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1699 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1700 for (tmp = skb->next; \
1701 skb != (struct sk_buff *)(queue); \
1702 skb = tmp, tmp = skb->next)
1704 #define skb_queue_reverse_walk(queue, skb) \
1705 for (skb = (queue)->prev; \
1706 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1710 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1711 int *peeked
, int *err
);
1712 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1713 int noblock
, int *err
);
1714 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1715 struct poll_table_struct
*wait
);
1716 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1717 int offset
, struct iovec
*to
,
1719 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1722 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1726 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1727 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1728 unsigned int flags
);
1729 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1730 int len
, __wsum csum
);
1731 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1733 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1734 const void *from
, int len
);
1735 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1736 int offset
, u8
*to
, int len
,
1738 extern int skb_splice_bits(struct sk_buff
*skb
,
1739 unsigned int offset
,
1740 struct pipe_inode_info
*pipe
,
1742 unsigned int flags
);
1743 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1744 extern void skb_split(struct sk_buff
*skb
,
1745 struct sk_buff
*skb1
, const u32 len
);
1746 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1749 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1751 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1752 int len
, void *buffer
)
1754 int hlen
= skb_headlen(skb
);
1756 if (hlen
- offset
>= len
)
1757 return skb
->data
+ offset
;
1759 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1765 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1767 const unsigned int len
)
1769 memcpy(to
, skb
->data
, len
);
1772 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1773 const int offset
, void *to
,
1774 const unsigned int len
)
1776 memcpy(to
, skb
->data
+ offset
, len
);
1779 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1781 const unsigned int len
)
1783 memcpy(skb
->data
, from
, len
);
1786 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1789 const unsigned int len
)
1791 memcpy(skb
->data
+ offset
, from
, len
);
1794 extern void skb_init(void);
1796 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1802 * skb_get_timestamp - get timestamp from a skb
1803 * @skb: skb to get stamp from
1804 * @stamp: pointer to struct timeval to store stamp in
1806 * Timestamps are stored in the skb as offsets to a base timestamp.
1807 * This function converts the offset back to a struct timeval and stores
1810 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1811 struct timeval
*stamp
)
1813 *stamp
= ktime_to_timeval(skb
->tstamp
);
1816 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1817 struct timespec
*stamp
)
1819 *stamp
= ktime_to_timespec(skb
->tstamp
);
1822 static inline void __net_timestamp(struct sk_buff
*skb
)
1824 skb
->tstamp
= ktime_get_real();
1827 static inline ktime_t
net_timedelta(ktime_t t
)
1829 return ktime_sub(ktime_get_real(), t
);
1832 static inline ktime_t
net_invalid_timestamp(void)
1834 return ktime_set(0, 0);
1838 * skb_tstamp_tx - queue clone of skb with send time stamps
1839 * @orig_skb: the original outgoing packet
1840 * @hwtstamps: hardware time stamps, may be NULL if not available
1842 * If the skb has a socket associated, then this function clones the
1843 * skb (thus sharing the actual data and optional structures), stores
1844 * the optional hardware time stamping information (if non NULL) or
1845 * generates a software time stamp (otherwise), then queues the clone
1846 * to the error queue of the socket. Errors are silently ignored.
1848 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1849 struct skb_shared_hwtstamps
*hwtstamps
);
1851 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1852 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1854 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1856 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1860 * skb_checksum_complete - Calculate checksum of an entire packet
1861 * @skb: packet to process
1863 * This function calculates the checksum over the entire packet plus
1864 * the value of skb->csum. The latter can be used to supply the
1865 * checksum of a pseudo header as used by TCP/UDP. It returns the
1868 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1869 * this function can be used to verify that checksum on received
1870 * packets. In that case the function should return zero if the
1871 * checksum is correct. In particular, this function will return zero
1872 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1873 * hardware has already verified the correctness of the checksum.
1875 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1877 return skb_csum_unnecessary(skb
) ?
1878 0 : __skb_checksum_complete(skb
);
1881 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1882 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1883 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1885 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1886 nf_conntrack_destroy(nfct
);
1888 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1891 atomic_inc(&nfct
->use
);
1893 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1896 atomic_inc(&skb
->users
);
1898 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1904 #ifdef CONFIG_BRIDGE_NETFILTER
1905 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1907 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1910 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1913 atomic_inc(&nf_bridge
->use
);
1915 #endif /* CONFIG_BRIDGE_NETFILTER */
1916 static inline void nf_reset(struct sk_buff
*skb
)
1918 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1919 nf_conntrack_put(skb
->nfct
);
1921 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1922 skb
->nfct_reasm
= NULL
;
1924 #ifdef CONFIG_BRIDGE_NETFILTER
1925 nf_bridge_put(skb
->nf_bridge
);
1926 skb
->nf_bridge
= NULL
;
1930 /* Note: This doesn't put any conntrack and bridge info in dst. */
1931 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1933 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1934 dst
->nfct
= src
->nfct
;
1935 nf_conntrack_get(src
->nfct
);
1936 dst
->nfctinfo
= src
->nfctinfo
;
1937 dst
->nfct_reasm
= src
->nfct_reasm
;
1938 nf_conntrack_get_reasm(src
->nfct_reasm
);
1940 #ifdef CONFIG_BRIDGE_NETFILTER
1941 dst
->nf_bridge
= src
->nf_bridge
;
1942 nf_bridge_get(src
->nf_bridge
);
1946 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1948 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1949 nf_conntrack_put(dst
->nfct
);
1950 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1952 #ifdef CONFIG_BRIDGE_NETFILTER
1953 nf_bridge_put(dst
->nf_bridge
);
1955 __nf_copy(dst
, src
);
1958 #ifdef CONFIG_NETWORK_SECMARK
1959 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1961 to
->secmark
= from
->secmark
;
1964 static inline void skb_init_secmark(struct sk_buff
*skb
)
1969 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1972 static inline void skb_init_secmark(struct sk_buff
*skb
)
1976 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1978 skb
->queue_mapping
= queue_mapping
;
1981 static inline u16
skb_get_queue_mapping(struct sk_buff
*skb
)
1983 return skb
->queue_mapping
;
1986 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1988 to
->queue_mapping
= from
->queue_mapping
;
1991 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
1993 skb
->queue_mapping
= rx_queue
+ 1;
1996 static inline u16
skb_get_rx_queue(struct sk_buff
*skb
)
1998 return skb
->queue_mapping
- 1;
2001 static inline bool skb_rx_queue_recorded(struct sk_buff
*skb
)
2003 return (skb
->queue_mapping
!= 0);
2007 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2012 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2018 static inline int skb_is_gso(const struct sk_buff
*skb
)
2020 return skb_shinfo(skb
)->gso_size
;
2023 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2025 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2028 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2030 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2032 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2033 * wanted then gso_type will be set. */
2034 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2035 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2036 __skb_warn_lro_forwarding(skb
);
2042 static inline void skb_forward_csum(struct sk_buff
*skb
)
2044 /* Unfortunately we don't support this one. Any brave souls? */
2045 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2046 skb
->ip_summed
= CHECKSUM_NONE
;
2049 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2050 #endif /* __KERNEL__ */
2051 #endif /* _LINUX_SKBUFF_H */