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/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/cache.h>
23 #include <linux/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/dmaengine.h>
31 #include <linux/hrtimer.h>
32 #include <linux/dma-mapping.h>
34 /* Don't change this without changing skb_csum_unnecessary! */
35 #define CHECKSUM_NONE 0
36 #define CHECKSUM_UNNECESSARY 1
37 #define CHECKSUM_COMPLETE 2
38 #define CHECKSUM_PARTIAL 3
40 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
41 ~(SMP_CACHE_BYTES - 1))
42 #define SKB_WITH_OVERHEAD(X) \
43 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
44 #define SKB_MAX_ORDER(X, ORDER) \
45 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
46 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
47 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
49 /* return minimum truesize of one skb containing X bytes of data */
50 #define SKB_TRUESIZE(X) ((X) + \
51 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
52 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
54 /* A. Checksumming of received packets by device.
56 * NONE: device failed to checksum this packet.
57 * skb->csum is undefined.
59 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
60 * skb->csum is undefined.
61 * It is bad option, but, unfortunately, many of vendors do this.
62 * Apparently with secret goal to sell you new device, when you
63 * will add new protocol to your host. F.e. IPv6. 8)
65 * COMPLETE: the most generic way. Device supplied checksum of _all_
66 * the packet as seen by netif_rx in skb->csum.
67 * NOTE: Even if device supports only some protocols, but
68 * is able to produce some skb->csum, it MUST use COMPLETE,
71 * PARTIAL: identical to the case for output below. This may occur
72 * on a packet received directly from another Linux OS, e.g.,
73 * a virtualised Linux kernel on the same host. The packet can
74 * be treated in the same way as UNNECESSARY except that on
75 * output (i.e., forwarding) the checksum must be filled in
76 * by the OS or the hardware.
78 * B. Checksumming on output.
80 * NONE: skb is checksummed by protocol or csum is not required.
82 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
83 * from skb->csum_start to the end and to record the checksum
84 * at skb->csum_start + skb->csum_offset.
86 * Device must show its capabilities in dev->features, set
87 * at device setup time.
88 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
90 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
91 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
92 * TCP/UDP over IPv4. Sigh. Vendors like this
93 * way by an unknown reason. Though, see comment above
94 * about CHECKSUM_UNNECESSARY. 8)
95 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
97 * Any questions? No questions, good. --ANK
102 struct pipe_inode_info;
104 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
105 struct nf_conntrack {
110 #ifdef CONFIG_BRIDGE_NETFILTER
111 struct nf_bridge_info {
113 struct net_device *physindev;
114 struct net_device *physoutdev;
116 unsigned long data[32 / sizeof(unsigned long)];
120 struct sk_buff_head {
121 /* These two members must be first. */
122 struct sk_buff *next;
123 struct sk_buff *prev;
131 /* To allow 64K frame to be packed as single skb without frag_list. Since
132 * GRO uses frags we allocate at least 16 regardless of page size.
134 #if (65536/PAGE_SIZE + 2) < 16
135 #define MAX_SKB_FRAGS 16UL
137 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
140 typedef struct skb_frag_struct skb_frag_t;
142 struct skb_frag_struct {
144 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
153 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
158 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
163 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
168 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
173 #define HAVE_HW_TIME_STAMP
176 * struct skb_shared_hwtstamps - hardware time stamps
177 * @hwtstamp: hardware time stamp transformed into duration
178 * since arbitrary point in time
179 * @syststamp: hwtstamp transformed to system time base
181 * Software time stamps generated by ktime_get_real() are stored in
182 * skb->tstamp. The relation between the different kinds of time
183 * stamps is as follows:
185 * syststamp and tstamp can be compared against each other in
186 * arbitrary combinations. The accuracy of a
187 * syststamp/tstamp/"syststamp from other device" comparison is
188 * limited by the accuracy of the transformation into system time
189 * base. This depends on the device driver and its underlying
192 * hwtstamps can only be compared against other hwtstamps from
195 * This structure is attached to packets as part of the
196 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
198 struct skb_shared_hwtstamps {
203 /* Definitions for tx_flags in struct skb_shared_info */
205 /* generate hardware time stamp */
206 SKBTX_HW_TSTAMP = 1 << 0,
208 /* generate software time stamp */
209 SKBTX_SW_TSTAMP = 1 << 1,
211 /* device driver is going to provide hardware time stamp */
212 SKBTX_IN_PROGRESS = 1 << 2,
214 /* ensure the originating sk reference is available on driver level */
215 SKBTX_DRV_NEEDS_SK_REF = 1 << 3,
217 /* device driver supports TX zero-copy buffers */
218 SKBTX_DEV_ZEROCOPY = 1 << 4,
222 * The callback notifies userspace to release buffers when skb DMA is done in
223 * lower device, the skb last reference should be 0 when calling this.
224 * The desc is used to track userspace buffer index.
227 void (*callback)(void *);
232 /* This data is invariant across clones and lives at
233 * the end of the header data, ie. at skb->end.
235 struct skb_shared_info {
236 unsigned short nr_frags;
237 unsigned short gso_size;
238 /* Warning: this field is not always filled in (UFO)! */
239 unsigned short gso_segs;
240 unsigned short gso_type;
243 struct sk_buff *frag_list;
244 struct skb_shared_hwtstamps hwtstamps;
247 * Warning : all fields before dataref are cleared in __alloc_skb()
251 /* Intermediate layers must ensure that destructor_arg
252 * remains valid until skb destructor */
253 void * destructor_arg;
255 /* must be last field, see pskb_expand_head() */
256 skb_frag_t frags[MAX_SKB_FRAGS];
259 /* We divide dataref into two halves. The higher 16 bits hold references
260 * to the payload part of skb->data. The lower 16 bits hold references to
261 * the entire skb->data. A clone of a headerless skb holds the length of
262 * the header in skb->hdr_len.
264 * All users must obey the rule that the skb->data reference count must be
265 * greater than or equal to the payload reference count.
267 * Holding a reference to the payload part means that the user does not
268 * care about modifications to the header part of skb->data.
270 #define SKB_DATAREF_SHIFT 16
271 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
275 SKB_FCLONE_UNAVAILABLE,
281 SKB_GSO_TCPV4 = 1 << 0,
282 SKB_GSO_UDP = 1 << 1,
284 /* This indicates the skb is from an untrusted source. */
285 SKB_GSO_DODGY = 1 << 2,
287 /* This indicates the tcp segment has CWR set. */
288 SKB_GSO_TCP_ECN = 1 << 3,
290 SKB_GSO_TCPV6 = 1 << 4,
292 SKB_GSO_FCOE = 1 << 5,
295 #if BITS_PER_LONG > 32
296 #define NET_SKBUFF_DATA_USES_OFFSET 1
299 #ifdef NET_SKBUFF_DATA_USES_OFFSET
300 typedef unsigned int sk_buff_data_t;
302 typedef unsigned char *sk_buff_data_t;
305 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
306 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
307 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
311 * struct sk_buff - socket buffer
312 * @next: Next buffer in list
313 * @prev: Previous buffer in list
314 * @tstamp: Time we arrived
315 * @sk: Socket we are owned by
316 * @dev: Device we arrived on/are leaving by
317 * @cb: Control buffer. Free for use by every layer. Put private vars here
318 * @_skb_refdst: destination entry (with norefcount bit)
319 * @sp: the security path, used for xfrm
320 * @len: Length of actual data
321 * @data_len: Data length
322 * @mac_len: Length of link layer header
323 * @hdr_len: writable header length of cloned skb
324 * @csum: Checksum (must include start/offset pair)
325 * @csum_start: Offset from skb->head where checksumming should start
326 * @csum_offset: Offset from csum_start where checksum should be stored
327 * @priority: Packet queueing priority
328 * @local_df: allow local fragmentation
329 * @cloned: Head may be cloned (check refcnt to be sure)
330 * @ip_summed: Driver fed us an IP checksum
331 * @nohdr: Payload reference only, must not modify header
332 * @nfctinfo: Relationship of this skb to the connection
333 * @pkt_type: Packet class
334 * @fclone: skbuff clone status
335 * @ipvs_property: skbuff is owned by ipvs
336 * @peeked: this packet has been seen already, so stats have been
337 * done for it, don't do them again
338 * @nf_trace: netfilter packet trace flag
339 * @protocol: Packet protocol from driver
340 * @destructor: Destruct function
341 * @nfct: Associated connection, if any
342 * @nfct_reasm: netfilter conntrack re-assembly pointer
343 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
344 * @skb_iif: ifindex of device we arrived on
345 * @tc_index: Traffic control index
346 * @tc_verd: traffic control verdict
347 * @rxhash: the packet hash computed on receive
348 * @queue_mapping: Queue mapping for multiqueue devices
349 * @ndisc_nodetype: router type (from link layer)
350 * @ooo_okay: allow the mapping of a socket to a queue to be changed
351 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
353 * @dma_cookie: a cookie to one of several possible DMA operations
354 * done by skb DMA functions
355 * @secmark: security marking
356 * @mark: Generic packet mark
357 * @dropcount: total number of sk_receive_queue overflows
358 * @vlan_tci: vlan tag control information
359 * @transport_header: Transport layer header
360 * @network_header: Network layer header
361 * @mac_header: Link layer header
362 * @tail: Tail pointer
364 * @head: Head of buffer
365 * @data: Data head pointer
366 * @truesize: Buffer size
367 * @users: User count - see {datagram,tcp}.c
371 /* These two members must be first. */
372 struct sk_buff *next;
373 struct sk_buff *prev;
378 struct net_device *dev;
381 * This is the control buffer. It is free to use for every
382 * layer. Please put your private variables there. If you
383 * want to keep them across layers you have to do a skb_clone()
384 * first. This is owned by whoever has the skb queued ATM.
386 char cb[48] __aligned(8);
388 unsigned long _skb_refdst;
404 kmemcheck_bitfield_begin(flags1);
415 kmemcheck_bitfield_end(flags1);
418 void (*destructor)(struct sk_buff *skb);
419 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
420 struct nf_conntrack *nfct;
422 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
423 struct sk_buff *nfct_reasm;
425 #ifdef CONFIG_BRIDGE_NETFILTER
426 struct nf_bridge_info *nf_bridge;
430 #ifdef CONFIG_NET_SCHED
431 __u16 tc_index; /* traffic control index */
432 #ifdef CONFIG_NET_CLS_ACT
433 __u16 tc_verd; /* traffic control verdict */
440 kmemcheck_bitfield_begin(flags2);
441 #ifdef CONFIG_IPV6_NDISC_NODETYPE
442 __u8 ndisc_nodetype:2;
446 kmemcheck_bitfield_end(flags2);
450 #ifdef CONFIG_NET_DMA
451 dma_cookie_t dma_cookie;
453 #ifdef CONFIG_NETWORK_SECMARK
463 sk_buff_data_t transport_header;
464 sk_buff_data_t network_header;
465 sk_buff_data_t mac_header;
466 /* These elements must be at the end, see alloc_skb() for details. */
471 unsigned int truesize;
477 * Handling routines are only of interest to the kernel
479 #include <linux/slab.h>
481 #include <asm/system.h>
484 * skb might have a dst pointer attached, refcounted or not.
485 * _skb_refdst low order bit is set if refcount was _not_ taken
487 #define SKB_DST_NOREF 1UL
488 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
491 * skb_dst - returns skb dst_entry
494 * Returns skb dst_entry, regardless of reference taken or not.
496 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
498 /* If refdst was not refcounted, check we still are in a
499 * rcu_read_lock section
501 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
502 !rcu_read_lock_held() &&
503 !rcu_read_lock_bh_held());
504 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
508 * skb_dst_set - sets skb dst
512 * Sets skb dst, assuming a reference was taken on dst and should
513 * be released by skb_dst_drop()
515 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
517 skb->_skb_refdst = (unsigned long)dst;
520 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
523 * skb_dst_is_noref - Test if skb dst isn't refcounted
526 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
528 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
531 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
533 return (struct rtable *)skb_dst(skb);
536 extern void kfree_skb(struct sk_buff *skb);
537 extern void consume_skb(struct sk_buff *skb);
538 extern void __kfree_skb(struct sk_buff *skb);
539 extern struct sk_buff *__alloc_skb(unsigned int size,
540 gfp_t priority, int fclone, int node);
541 static inline struct sk_buff *alloc_skb(unsigned int size,
544 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
547 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
550 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
553 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
555 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
556 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
557 extern struct sk_buff *skb_clone(struct sk_buff *skb,
559 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
561 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
563 extern int pskb_expand_head(struct sk_buff *skb,
564 int nhead, int ntail,
566 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
567 unsigned int headroom);
568 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
569 int newheadroom, int newtailroom,
571 extern int skb_to_sgvec(struct sk_buff *skb,
572 struct scatterlist *sg, int offset,
574 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
575 struct sk_buff **trailer);
576 extern int skb_pad(struct sk_buff *skb, int pad);
577 #define dev_kfree_skb(a) consume_skb(a)
579 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
580 int getfrag(void *from, char *to, int offset,
581 int len,int odd, struct sk_buff *skb),
582 void *from, int length);
584 struct skb_seq_state {
588 __u32 stepped_offset;
589 struct sk_buff *root_skb;
590 struct sk_buff *cur_skb;
594 extern void skb_prepare_seq_read(struct sk_buff *skb,
595 unsigned int from, unsigned int to,
596 struct skb_seq_state *st);
597 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
598 struct skb_seq_state *st);
599 extern void skb_abort_seq_read(struct skb_seq_state *st);
601 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
602 unsigned int to, struct ts_config *config,
603 struct ts_state *state);
605 extern void __skb_get_rxhash(struct sk_buff *skb);
606 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
609 __skb_get_rxhash(skb);
614 #ifdef NET_SKBUFF_DATA_USES_OFFSET
615 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
617 return skb->head + skb->end;
620 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
627 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
629 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
631 return &skb_shinfo(skb)->hwtstamps;
635 * skb_queue_empty - check if a queue is empty
638 * Returns true if the queue is empty, false otherwise.
640 static inline int skb_queue_empty(const struct sk_buff_head *list)
642 return list->next == (struct sk_buff *)list;
646 * skb_queue_is_last - check if skb is the last entry in the queue
650 * Returns true if @skb is the last buffer on the list.
652 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
653 const struct sk_buff *skb)
655 return skb->next == (struct sk_buff *)list;
659 * skb_queue_is_first - check if skb is the first entry in the queue
663 * Returns true if @skb is the first buffer on the list.
665 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
666 const struct sk_buff *skb)
668 return skb->prev == (struct sk_buff *)list;
672 * skb_queue_next - return the next packet in the queue
674 * @skb: current buffer
676 * Return the next packet in @list after @skb. It is only valid to
677 * call this if skb_queue_is_last() evaluates to false.
679 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
680 const struct sk_buff *skb)
682 /* This BUG_ON may seem severe, but if we just return then we
683 * are going to dereference garbage.
685 BUG_ON(skb_queue_is_last(list, skb));
690 * skb_queue_prev - return the prev packet in the queue
692 * @skb: current buffer
694 * Return the prev packet in @list before @skb. It is only valid to
695 * call this if skb_queue_is_first() evaluates to false.
697 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
698 const struct sk_buff *skb)
700 /* This BUG_ON may seem severe, but if we just return then we
701 * are going to dereference garbage.
703 BUG_ON(skb_queue_is_first(list, skb));
708 * skb_get - reference buffer
709 * @skb: buffer to reference
711 * Makes another reference to a socket buffer and returns a pointer
714 static inline struct sk_buff *skb_get(struct sk_buff *skb)
716 atomic_inc(&skb->users);
721 * If users == 1, we are the only owner and are can avoid redundant
726 * skb_cloned - is the buffer a clone
727 * @skb: buffer to check
729 * Returns true if the buffer was generated with skb_clone() and is
730 * one of multiple shared copies of the buffer. Cloned buffers are
731 * shared data so must not be written to under normal circumstances.
733 static inline int skb_cloned(const struct sk_buff *skb)
735 return skb->cloned &&
736 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
740 * skb_header_cloned - is the header a clone
741 * @skb: buffer to check
743 * Returns true if modifying the header part of the buffer requires
744 * the data to be copied.
746 static inline int skb_header_cloned(const struct sk_buff *skb)
753 dataref = atomic_read(&skb_shinfo(skb)->dataref);
754 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
759 * skb_header_release - release reference to header
760 * @skb: buffer to operate on
762 * Drop a reference to the header part of the buffer. This is done
763 * by acquiring a payload reference. You must not read from the header
764 * part of skb->data after this.
766 static inline void skb_header_release(struct sk_buff *skb)
770 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
774 * skb_shared - is the buffer shared
775 * @skb: buffer to check
777 * Returns true if more than one person has a reference to this
780 static inline int skb_shared(const struct sk_buff *skb)
782 return atomic_read(&skb->users) != 1;
786 * skb_share_check - check if buffer is shared and if so clone it
787 * @skb: buffer to check
788 * @pri: priority for memory allocation
790 * If the buffer is shared the buffer is cloned and the old copy
791 * drops a reference. A new clone with a single reference is returned.
792 * If the buffer is not shared the original buffer is returned. When
793 * being called from interrupt status or with spinlocks held pri must
796 * NULL is returned on a memory allocation failure.
798 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
801 might_sleep_if(pri & __GFP_WAIT);
802 if (skb_shared(skb)) {
803 struct sk_buff *nskb = skb_clone(skb, pri);
811 * Copy shared buffers into a new sk_buff. We effectively do COW on
812 * packets to handle cases where we have a local reader and forward
813 * and a couple of other messy ones. The normal one is tcpdumping
814 * a packet thats being forwarded.
818 * skb_unshare - make a copy of a shared buffer
819 * @skb: buffer to check
820 * @pri: priority for memory allocation
822 * If the socket buffer is a clone then this function creates a new
823 * copy of the data, drops a reference count on the old copy and returns
824 * the new copy with the reference count at 1. If the buffer is not a clone
825 * the original buffer is returned. When called with a spinlock held or
826 * from interrupt state @pri must be %GFP_ATOMIC
828 * %NULL is returned on a memory allocation failure.
830 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
833 might_sleep_if(pri & __GFP_WAIT);
834 if (skb_cloned(skb)) {
835 struct sk_buff *nskb = skb_copy(skb, pri);
836 kfree_skb(skb); /* Free our shared copy */
843 * skb_peek - peek at the head of an &sk_buff_head
844 * @list_: list to peek at
846 * Peek an &sk_buff. Unlike most other operations you _MUST_
847 * be careful with this one. A peek leaves the buffer on the
848 * list and someone else may run off with it. You must hold
849 * the appropriate locks or have a private queue to do this.
851 * Returns %NULL for an empty list or a pointer to the head element.
852 * The reference count is not incremented and the reference is therefore
853 * volatile. Use with caution.
855 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
857 struct sk_buff *list = ((struct sk_buff *)list_)->next;
858 if (list == (struct sk_buff *)list_)
864 * skb_peek_tail - peek at the tail of an &sk_buff_head
865 * @list_: list to peek at
867 * Peek an &sk_buff. Unlike most other operations you _MUST_
868 * be careful with this one. A peek leaves the buffer on the
869 * list and someone else may run off with it. You must hold
870 * the appropriate locks or have a private queue to do this.
872 * Returns %NULL for an empty list or a pointer to the tail element.
873 * The reference count is not incremented and the reference is therefore
874 * volatile. Use with caution.
876 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
878 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
879 if (list == (struct sk_buff *)list_)
885 * skb_queue_len - get queue length
886 * @list_: list to measure
888 * Return the length of an &sk_buff queue.
890 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
896 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
897 * @list: queue to initialize
899 * This initializes only the list and queue length aspects of
900 * an sk_buff_head object. This allows to initialize the list
901 * aspects of an sk_buff_head without reinitializing things like
902 * the spinlock. It can also be used for on-stack sk_buff_head
903 * objects where the spinlock is known to not be used.
905 static inline void __skb_queue_head_init(struct sk_buff_head *list)
907 list->prev = list->next = (struct sk_buff *)list;
912 * This function creates a split out lock class for each invocation;
913 * this is needed for now since a whole lot of users of the skb-queue
914 * infrastructure in drivers have different locking usage (in hardirq)
915 * than the networking core (in softirq only). In the long run either the
916 * network layer or drivers should need annotation to consolidate the
917 * main types of usage into 3 classes.
919 static inline void skb_queue_head_init(struct sk_buff_head *list)
921 spin_lock_init(&list->lock);
922 __skb_queue_head_init(list);
925 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
926 struct lock_class_key *class)
928 skb_queue_head_init(list);
929 lockdep_set_class(&list->lock, class);
933 * Insert an sk_buff on a list.
935 * The "__skb_xxxx()" functions are the non-atomic ones that
936 * can only be called with interrupts disabled.
938 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
939 static inline void __skb_insert(struct sk_buff *newsk,
940 struct sk_buff *prev, struct sk_buff *next,
941 struct sk_buff_head *list)
945 next->prev = prev->next = newsk;
949 static inline void __skb_queue_splice(const struct sk_buff_head *list,
950 struct sk_buff *prev,
951 struct sk_buff *next)
953 struct sk_buff *first = list->next;
954 struct sk_buff *last = list->prev;
964 * skb_queue_splice - join two skb lists, this is designed for stacks
965 * @list: the new list to add
966 * @head: the place to add it in the first list
968 static inline void skb_queue_splice(const struct sk_buff_head *list,
969 struct sk_buff_head *head)
971 if (!skb_queue_empty(list)) {
972 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
973 head->qlen += list->qlen;
978 * skb_queue_splice - join two skb lists and reinitialise the emptied list
979 * @list: the new list to add
980 * @head: the place to add it in the first list
982 * The list at @list is reinitialised
984 static inline void skb_queue_splice_init(struct sk_buff_head *list,
985 struct sk_buff_head *head)
987 if (!skb_queue_empty(list)) {
988 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
989 head->qlen += list->qlen;
990 __skb_queue_head_init(list);
995 * skb_queue_splice_tail - join two skb lists, each list being a queue
996 * @list: the new list to add
997 * @head: the place to add it in the first list
999 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1000 struct sk_buff_head *head)
1002 if (!skb_queue_empty(list)) {
1003 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1004 head->qlen += list->qlen;
1009 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1010 * @list: the new list to add
1011 * @head: the place to add it in the first list
1013 * Each of the lists is a queue.
1014 * The list at @list is reinitialised
1016 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1017 struct sk_buff_head *head)
1019 if (!skb_queue_empty(list)) {
1020 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1021 head->qlen += list->qlen;
1022 __skb_queue_head_init(list);
1027 * __skb_queue_after - queue a buffer at the list head
1028 * @list: list to use
1029 * @prev: place after this buffer
1030 * @newsk: buffer to queue
1032 * Queue a buffer int the middle of a list. This function takes no locks
1033 * and you must therefore hold required locks before calling it.
1035 * A buffer cannot be placed on two lists at the same time.
1037 static inline void __skb_queue_after(struct sk_buff_head *list,
1038 struct sk_buff *prev,
1039 struct sk_buff *newsk)
1041 __skb_insert(newsk, prev, prev->next, list);
1044 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1045 struct sk_buff_head *list);
1047 static inline void __skb_queue_before(struct sk_buff_head *list,
1048 struct sk_buff *next,
1049 struct sk_buff *newsk)
1051 __skb_insert(newsk, next->prev, next, list);
1055 * __skb_queue_head - queue a buffer at the list head
1056 * @list: list to use
1057 * @newsk: buffer to queue
1059 * Queue a buffer at the start of a list. This function takes no locks
1060 * and you must therefore hold required locks before calling it.
1062 * A buffer cannot be placed on two lists at the same time.
1064 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1065 static inline void __skb_queue_head(struct sk_buff_head *list,
1066 struct sk_buff *newsk)
1068 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1072 * __skb_queue_tail - queue a buffer at the list tail
1073 * @list: list to use
1074 * @newsk: buffer to queue
1076 * Queue a buffer at the end of a list. This function takes no locks
1077 * and you must therefore hold required locks before calling it.
1079 * A buffer cannot be placed on two lists at the same time.
1081 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1082 static inline void __skb_queue_tail(struct sk_buff_head *list,
1083 struct sk_buff *newsk)
1085 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1089 * remove sk_buff from list. _Must_ be called atomically, and with
1092 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1093 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1095 struct sk_buff *next, *prev;
1100 skb->next = skb->prev = NULL;
1106 * __skb_dequeue - remove from the head of the queue
1107 * @list: list to dequeue from
1109 * Remove the head of the list. This function does not take any locks
1110 * so must be used with appropriate locks held only. The head item is
1111 * returned or %NULL if the list is empty.
1113 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1114 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1116 struct sk_buff *skb = skb_peek(list);
1118 __skb_unlink(skb, list);
1123 * __skb_dequeue_tail - remove from the tail of the queue
1124 * @list: list to dequeue from
1126 * Remove the tail of the list. This function does not take any locks
1127 * so must be used with appropriate locks held only. The tail item is
1128 * returned or %NULL if the list is empty.
1130 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1131 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1133 struct sk_buff *skb = skb_peek_tail(list);
1135 __skb_unlink(skb, list);
1140 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1142 return skb->data_len;
1145 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1147 return skb->len - skb->data_len;
1150 static inline int skb_pagelen(const struct sk_buff *skb)
1154 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1155 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1156 return len + skb_headlen(skb);
1160 * __skb_fill_page_desc - initialise a paged fragment in an skb
1161 * @skb: buffer containing fragment to be initialised
1162 * @i: paged fragment index to initialise
1163 * @page: the page to use for this fragment
1164 * @off: the offset to the data with @page
1165 * @size: the length of the data
1167 * Initialises the @i'th fragment of @skb to point to &size bytes at
1168 * offset @off within @page.
1170 * Does not take any additional reference on the fragment.
1172 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1173 struct page *page, int off, int size)
1175 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1178 frag->page_offset = off;
1179 skb_frag_size_set(frag, size);
1183 * skb_fill_page_desc - initialise a paged fragment in an skb
1184 * @skb: buffer containing fragment to be initialised
1185 * @i: paged fragment index to initialise
1186 * @page: the page to use for this fragment
1187 * @off: the offset to the data with @page
1188 * @size: the length of the data
1190 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1191 * @skb to point to &size bytes at offset @off within @page. In
1192 * addition updates @skb such that @i is the last fragment.
1194 * Does not take any additional reference on the fragment.
1196 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1197 struct page *page, int off, int size)
1199 __skb_fill_page_desc(skb, i, page, off, size);
1200 skb_shinfo(skb)->nr_frags = i + 1;
1203 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1206 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1207 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1208 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1210 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1211 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1213 return skb->head + skb->tail;
1216 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1218 skb->tail = skb->data - skb->head;
1221 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1223 skb_reset_tail_pointer(skb);
1224 skb->tail += offset;
1226 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1227 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1232 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1234 skb->tail = skb->data;
1237 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1239 skb->tail = skb->data + offset;
1242 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1245 * Add data to an sk_buff
1247 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1248 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1250 unsigned char *tmp = skb_tail_pointer(skb);
1251 SKB_LINEAR_ASSERT(skb);
1257 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1258 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1265 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1266 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1269 BUG_ON(skb->len < skb->data_len);
1270 return skb->data += len;
1273 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1275 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1278 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1280 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1282 if (len > skb_headlen(skb) &&
1283 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1286 return skb->data += len;
1289 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1291 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1294 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1296 if (likely(len <= skb_headlen(skb)))
1298 if (unlikely(len > skb->len))
1300 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1304 * skb_headroom - bytes at buffer head
1305 * @skb: buffer to check
1307 * Return the number of bytes of free space at the head of an &sk_buff.
1309 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1311 return skb->data - skb->head;
1315 * skb_tailroom - bytes at buffer end
1316 * @skb: buffer to check
1318 * Return the number of bytes of free space at the tail of an sk_buff
1320 static inline int skb_tailroom(const struct sk_buff *skb)
1322 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1326 * skb_reserve - adjust headroom
1327 * @skb: buffer to alter
1328 * @len: bytes to move
1330 * Increase the headroom of an empty &sk_buff by reducing the tail
1331 * room. This is only allowed for an empty buffer.
1333 static inline void skb_reserve(struct sk_buff *skb, int len)
1339 static inline void skb_reset_mac_len(struct sk_buff *skb)
1341 skb->mac_len = skb->network_header - skb->mac_header;
1344 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1345 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1347 return skb->head + skb->transport_header;
1350 static inline void skb_reset_transport_header(struct sk_buff *skb)
1352 skb->transport_header = skb->data - skb->head;
1355 static inline void skb_set_transport_header(struct sk_buff *skb,
1358 skb_reset_transport_header(skb);
1359 skb->transport_header += offset;
1362 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1364 return skb->head + skb->network_header;
1367 static inline void skb_reset_network_header(struct sk_buff *skb)
1369 skb->network_header = skb->data - skb->head;
1372 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1374 skb_reset_network_header(skb);
1375 skb->network_header += offset;
1378 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1380 return skb->head + skb->mac_header;
1383 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1385 return skb->mac_header != ~0U;
1388 static inline void skb_reset_mac_header(struct sk_buff *skb)
1390 skb->mac_header = skb->data - skb->head;
1393 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1395 skb_reset_mac_header(skb);
1396 skb->mac_header += offset;
1399 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1401 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1403 return skb->transport_header;
1406 static inline void skb_reset_transport_header(struct sk_buff *skb)
1408 skb->transport_header = skb->data;
1411 static inline void skb_set_transport_header(struct sk_buff *skb,
1414 skb->transport_header = skb->data + offset;
1417 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1419 return skb->network_header;
1422 static inline void skb_reset_network_header(struct sk_buff *skb)
1424 skb->network_header = skb->data;
1427 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1429 skb->network_header = skb->data + offset;
1432 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1434 return skb->mac_header;
1437 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1439 return skb->mac_header != NULL;
1442 static inline void skb_reset_mac_header(struct sk_buff *skb)
1444 skb->mac_header = skb->data;
1447 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1449 skb->mac_header = skb->data + offset;
1451 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1453 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1455 return skb->csum_start - skb_headroom(skb);
1458 static inline int skb_transport_offset(const struct sk_buff *skb)
1460 return skb_transport_header(skb) - skb->data;
1463 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1465 return skb->transport_header - skb->network_header;
1468 static inline int skb_network_offset(const struct sk_buff *skb)
1470 return skb_network_header(skb) - skb->data;
1473 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1475 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1479 * CPUs often take a performance hit when accessing unaligned memory
1480 * locations. The actual performance hit varies, it can be small if the
1481 * hardware handles it or large if we have to take an exception and fix it
1484 * Since an ethernet header is 14 bytes network drivers often end up with
1485 * the IP header at an unaligned offset. The IP header can be aligned by
1486 * shifting the start of the packet by 2 bytes. Drivers should do this
1489 * skb_reserve(skb, NET_IP_ALIGN);
1491 * The downside to this alignment of the IP header is that the DMA is now
1492 * unaligned. On some architectures the cost of an unaligned DMA is high
1493 * and this cost outweighs the gains made by aligning the IP header.
1495 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1498 #ifndef NET_IP_ALIGN
1499 #define NET_IP_ALIGN 2
1503 * The networking layer reserves some headroom in skb data (via
1504 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1505 * the header has to grow. In the default case, if the header has to grow
1506 * 32 bytes or less we avoid the reallocation.
1508 * Unfortunately this headroom changes the DMA alignment of the resulting
1509 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1510 * on some architectures. An architecture can override this value,
1511 * perhaps setting it to a cacheline in size (since that will maintain
1512 * cacheline alignment of the DMA). It must be a power of 2.
1514 * Various parts of the networking layer expect at least 32 bytes of
1515 * headroom, you should not reduce this.
1517 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1518 * to reduce average number of cache lines per packet.
1519 * get_rps_cpus() for example only access one 64 bytes aligned block :
1520 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1523 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1526 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1528 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1530 if (unlikely(skb_is_nonlinear(skb))) {
1535 skb_set_tail_pointer(skb, len);
1538 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1540 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1543 return ___pskb_trim(skb, len);
1544 __skb_trim(skb, len);
1548 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1550 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1554 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1555 * @skb: buffer to alter
1558 * This is identical to pskb_trim except that the caller knows that
1559 * the skb is not cloned so we should never get an error due to out-
1562 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1564 int err = pskb_trim(skb, len);
1569 * skb_orphan - orphan a buffer
1570 * @skb: buffer to orphan
1572 * If a buffer currently has an owner then we call the owner's
1573 * destructor function and make the @skb unowned. The buffer continues
1574 * to exist but is no longer charged to its former owner.
1576 static inline void skb_orphan(struct sk_buff *skb)
1578 if (skb->destructor)
1579 skb->destructor(skb);
1580 skb->destructor = NULL;
1585 * __skb_queue_purge - empty a list
1586 * @list: list to empty
1588 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1589 * the list and one reference dropped. This function does not take the
1590 * list lock and the caller must hold the relevant locks to use it.
1592 extern void skb_queue_purge(struct sk_buff_head *list);
1593 static inline void __skb_queue_purge(struct sk_buff_head *list)
1595 struct sk_buff *skb;
1596 while ((skb = __skb_dequeue(list)) != NULL)
1601 * __dev_alloc_skb - allocate an skbuff for receiving
1602 * @length: length to allocate
1603 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1605 * Allocate a new &sk_buff and assign it a usage count of one. The
1606 * buffer has unspecified headroom built in. Users should allocate
1607 * the headroom they think they need without accounting for the
1608 * built in space. The built in space is used for optimisations.
1610 * %NULL is returned if there is no free memory.
1612 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1615 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1617 skb_reserve(skb, NET_SKB_PAD);
1621 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1623 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1624 unsigned int length, gfp_t gfp_mask);
1627 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1628 * @dev: network device to receive on
1629 * @length: length to allocate
1631 * Allocate a new &sk_buff and assign it a usage count of one. The
1632 * buffer has unspecified headroom built in. Users should allocate
1633 * the headroom they think they need without accounting for the
1634 * built in space. The built in space is used for optimisations.
1636 * %NULL is returned if there is no free memory. Although this function
1637 * allocates memory it can be called from an interrupt.
1639 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1640 unsigned int length)
1642 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1645 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1646 unsigned int length, gfp_t gfp)
1648 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1650 if (NET_IP_ALIGN && skb)
1651 skb_reserve(skb, NET_IP_ALIGN);
1655 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1656 unsigned int length)
1658 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1662 * __netdev_alloc_page - allocate a page for ps-rx on a specific device
1663 * @dev: network device to receive on
1664 * @gfp_mask: alloc_pages_node mask
1666 * Allocate a new page. dev currently unused.
1668 * %NULL is returned if there is no free memory.
1670 static inline struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
1672 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, 0);
1676 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1677 * @dev: network device to receive on
1679 * Allocate a new page. dev currently unused.
1681 * %NULL is returned if there is no free memory.
1683 static inline struct page *netdev_alloc_page(struct net_device *dev)
1685 return __netdev_alloc_page(dev, GFP_ATOMIC);
1688 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1694 * skb_frag_page - retrieve the page refered to by a paged fragment
1695 * @frag: the paged fragment
1697 * Returns the &struct page associated with @frag.
1699 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1705 * __skb_frag_ref - take an addition reference on a paged fragment.
1706 * @frag: the paged fragment
1708 * Takes an additional reference on the paged fragment @frag.
1710 static inline void __skb_frag_ref(skb_frag_t *frag)
1712 get_page(skb_frag_page(frag));
1716 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1718 * @f: the fragment offset.
1720 * Takes an additional reference on the @f'th paged fragment of @skb.
1722 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1724 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1728 * __skb_frag_unref - release a reference on a paged fragment.
1729 * @frag: the paged fragment
1731 * Releases a reference on the paged fragment @frag.
1733 static inline void __skb_frag_unref(skb_frag_t *frag)
1735 put_page(skb_frag_page(frag));
1739 * skb_frag_unref - release a reference on a paged fragment of an skb.
1741 * @f: the fragment offset
1743 * Releases a reference on the @f'th paged fragment of @skb.
1745 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1747 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1751 * skb_frag_address - gets the address of the data contained in a paged fragment
1752 * @frag: the paged fragment buffer
1754 * Returns the address of the data within @frag. The page must already
1757 static inline void *skb_frag_address(const skb_frag_t *frag)
1759 return page_address(skb_frag_page(frag)) + frag->page_offset;
1763 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1764 * @frag: the paged fragment buffer
1766 * Returns the address of the data within @frag. Checks that the page
1767 * is mapped and returns %NULL otherwise.
1769 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1771 void *ptr = page_address(skb_frag_page(frag));
1775 return ptr + frag->page_offset;
1779 * __skb_frag_set_page - sets the page contained in a paged fragment
1780 * @frag: the paged fragment
1781 * @page: the page to set
1783 * Sets the fragment @frag to contain @page.
1785 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1788 __skb_frag_ref(frag);
1792 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1794 * @f: the fragment offset
1795 * @page: the page to set
1797 * Sets the @f'th fragment of @skb to contain @page.
1799 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1802 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1806 * skb_frag_dma_map - maps a paged fragment via the DMA API
1807 * @device: the device to map the fragment to
1808 * @frag: the paged fragment to map
1809 * @offset: the offset within the fragment (starting at the
1810 * fragment's own offset)
1811 * @size: the number of bytes to map
1812 * @direction: the direction of the mapping (%PCI_DMA_*)
1814 * Maps the page associated with @frag to @device.
1816 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1817 const skb_frag_t *frag,
1818 size_t offset, size_t size,
1819 enum dma_data_direction dir)
1821 return dma_map_page(dev, skb_frag_page(frag),
1822 frag->page_offset + offset, size, dir);
1826 * skb_clone_writable - is the header of a clone writable
1827 * @skb: buffer to check
1828 * @len: length up to which to write
1830 * Returns true if modifying the header part of the cloned buffer
1831 * does not requires the data to be copied.
1833 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1835 return !skb_header_cloned(skb) &&
1836 skb_headroom(skb) + len <= skb->hdr_len;
1839 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1844 if (headroom < NET_SKB_PAD)
1845 headroom = NET_SKB_PAD;
1846 if (headroom > skb_headroom(skb))
1847 delta = headroom - skb_headroom(skb);
1849 if (delta || cloned)
1850 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1856 * skb_cow - copy header of skb when it is required
1857 * @skb: buffer to cow
1858 * @headroom: needed headroom
1860 * If the skb passed lacks sufficient headroom or its data part
1861 * is shared, data is reallocated. If reallocation fails, an error
1862 * is returned and original skb is not changed.
1864 * The result is skb with writable area skb->head...skb->tail
1865 * and at least @headroom of space at head.
1867 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1869 return __skb_cow(skb, headroom, skb_cloned(skb));
1873 * skb_cow_head - skb_cow but only making the head writable
1874 * @skb: buffer to cow
1875 * @headroom: needed headroom
1877 * This function is identical to skb_cow except that we replace the
1878 * skb_cloned check by skb_header_cloned. It should be used when
1879 * you only need to push on some header and do not need to modify
1882 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1884 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1888 * skb_padto - pad an skbuff up to a minimal size
1889 * @skb: buffer to pad
1890 * @len: minimal length
1892 * Pads up a buffer to ensure the trailing bytes exist and are
1893 * blanked. If the buffer already contains sufficient data it
1894 * is untouched. Otherwise it is extended. Returns zero on
1895 * success. The skb is freed on error.
1898 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1900 unsigned int size = skb->len;
1901 if (likely(size >= len))
1903 return skb_pad(skb, len - size);
1906 static inline int skb_add_data(struct sk_buff *skb,
1907 char __user *from, int copy)
1909 const int off = skb->len;
1911 if (skb->ip_summed == CHECKSUM_NONE) {
1913 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1916 skb->csum = csum_block_add(skb->csum, csum, off);
1919 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1922 __skb_trim(skb, off);
1926 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1927 const struct page *page, int off)
1930 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1932 return page == skb_frag_page(frag) &&
1933 off == frag->page_offset + skb_frag_size(frag);
1938 static inline int __skb_linearize(struct sk_buff *skb)
1940 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1944 * skb_linearize - convert paged skb to linear one
1945 * @skb: buffer to linarize
1947 * If there is no free memory -ENOMEM is returned, otherwise zero
1948 * is returned and the old skb data released.
1950 static inline int skb_linearize(struct sk_buff *skb)
1952 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1956 * skb_linearize_cow - make sure skb is linear and writable
1957 * @skb: buffer to process
1959 * If there is no free memory -ENOMEM is returned, otherwise zero
1960 * is returned and the old skb data released.
1962 static inline int skb_linearize_cow(struct sk_buff *skb)
1964 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1965 __skb_linearize(skb) : 0;
1969 * skb_postpull_rcsum - update checksum for received skb after pull
1970 * @skb: buffer to update
1971 * @start: start of data before pull
1972 * @len: length of data pulled
1974 * After doing a pull on a received packet, you need to call this to
1975 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1976 * CHECKSUM_NONE so that it can be recomputed from scratch.
1979 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1980 const void *start, unsigned int len)
1982 if (skb->ip_summed == CHECKSUM_COMPLETE)
1983 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1986 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1989 * pskb_trim_rcsum - trim received skb and update checksum
1990 * @skb: buffer to trim
1993 * This is exactly the same as pskb_trim except that it ensures the
1994 * checksum of received packets are still valid after the operation.
1997 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1999 if (likely(len >= skb->len))
2001 if (skb->ip_summed == CHECKSUM_COMPLETE)
2002 skb->ip_summed = CHECKSUM_NONE;
2003 return __pskb_trim(skb, len);
2006 #define skb_queue_walk(queue, skb) \
2007 for (skb = (queue)->next; \
2008 skb != (struct sk_buff *)(queue); \
2011 #define skb_queue_walk_safe(queue, skb, tmp) \
2012 for (skb = (queue)->next, tmp = skb->next; \
2013 skb != (struct sk_buff *)(queue); \
2014 skb = tmp, tmp = skb->next)
2016 #define skb_queue_walk_from(queue, skb) \
2017 for (; skb != (struct sk_buff *)(queue); \
2020 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2021 for (tmp = skb->next; \
2022 skb != (struct sk_buff *)(queue); \
2023 skb = tmp, tmp = skb->next)
2025 #define skb_queue_reverse_walk(queue, skb) \
2026 for (skb = (queue)->prev; \
2027 skb != (struct sk_buff *)(queue); \
2030 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2031 for (skb = (queue)->prev, tmp = skb->prev; \
2032 skb != (struct sk_buff *)(queue); \
2033 skb = tmp, tmp = skb->prev)
2035 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2036 for (tmp = skb->prev; \
2037 skb != (struct sk_buff *)(queue); \
2038 skb = tmp, tmp = skb->prev)
2040 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2042 return skb_shinfo(skb)->frag_list != NULL;
2045 static inline void skb_frag_list_init(struct sk_buff *skb)
2047 skb_shinfo(skb)->frag_list = NULL;
2050 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2052 frag->next = skb_shinfo(skb)->frag_list;
2053 skb_shinfo(skb)->frag_list = frag;
2056 #define skb_walk_frags(skb, iter) \
2057 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2059 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2060 int *peeked, int *err);
2061 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2062 int noblock, int *err);
2063 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2064 struct poll_table_struct *wait);
2065 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2066 int offset, struct iovec *to,
2068 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2071 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2073 const struct iovec *from,
2076 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2078 const struct iovec *to,
2081 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2082 extern void skb_free_datagram_locked(struct sock *sk,
2083 struct sk_buff *skb);
2084 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2085 unsigned int flags);
2086 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2087 int len, __wsum csum);
2088 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2090 extern int skb_store_bits(struct sk_buff *skb, int offset,
2091 const void *from, int len);
2092 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2093 int offset, u8 *to, int len,
2095 extern int skb_splice_bits(struct sk_buff *skb,
2096 unsigned int offset,
2097 struct pipe_inode_info *pipe,
2099 unsigned int flags);
2100 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2101 extern void skb_split(struct sk_buff *skb,
2102 struct sk_buff *skb1, const u32 len);
2103 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2106 extern struct sk_buff *skb_segment(struct sk_buff *skb, u32 features);
2108 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2109 int len, void *buffer)
2111 int hlen = skb_headlen(skb);
2113 if (hlen - offset >= len)
2114 return skb->data + offset;
2116 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2122 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2124 const unsigned int len)
2126 memcpy(to, skb->data, len);
2129 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2130 const int offset, void *to,
2131 const unsigned int len)
2133 memcpy(to, skb->data + offset, len);
2136 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2138 const unsigned int len)
2140 memcpy(skb->data, from, len);
2143 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2146 const unsigned int len)
2148 memcpy(skb->data + offset, from, len);
2151 extern void skb_init(void);
2153 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2159 * skb_get_timestamp - get timestamp from a skb
2160 * @skb: skb to get stamp from
2161 * @stamp: pointer to struct timeval to store stamp in
2163 * Timestamps are stored in the skb as offsets to a base timestamp.
2164 * This function converts the offset back to a struct timeval and stores
2167 static inline void skb_get_timestamp(const struct sk_buff *skb,
2168 struct timeval *stamp)
2170 *stamp = ktime_to_timeval(skb->tstamp);
2173 static inline void skb_get_timestampns(const struct sk_buff *skb,
2174 struct timespec *stamp)
2176 *stamp = ktime_to_timespec(skb->tstamp);
2179 static inline void __net_timestamp(struct sk_buff *skb)
2181 skb->tstamp = ktime_get_real();
2184 static inline ktime_t net_timedelta(ktime_t t)
2186 return ktime_sub(ktime_get_real(), t);
2189 static inline ktime_t net_invalid_timestamp(void)
2191 return ktime_set(0, 0);
2194 extern void skb_timestamping_init(void);
2196 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2198 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2199 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2201 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2203 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2207 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2212 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2215 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2217 * @skb: clone of the the original outgoing packet
2218 * @hwtstamps: hardware time stamps
2221 void skb_complete_tx_timestamp(struct sk_buff *skb,
2222 struct skb_shared_hwtstamps *hwtstamps);
2225 * skb_tstamp_tx - queue clone of skb with send time stamps
2226 * @orig_skb: the original outgoing packet
2227 * @hwtstamps: hardware time stamps, may be NULL if not available
2229 * If the skb has a socket associated, then this function clones the
2230 * skb (thus sharing the actual data and optional structures), stores
2231 * the optional hardware time stamping information (if non NULL) or
2232 * generates a software time stamp (otherwise), then queues the clone
2233 * to the error queue of the socket. Errors are silently ignored.
2235 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2236 struct skb_shared_hwtstamps *hwtstamps);
2238 static inline void sw_tx_timestamp(struct sk_buff *skb)
2240 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2241 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2242 skb_tstamp_tx(skb, NULL);
2246 * skb_tx_timestamp() - Driver hook for transmit timestamping
2248 * Ethernet MAC Drivers should call this function in their hard_xmit()
2249 * function immediately before giving the sk_buff to the MAC hardware.
2251 * @skb: A socket buffer.
2253 static inline void skb_tx_timestamp(struct sk_buff *skb)
2255 skb_clone_tx_timestamp(skb);
2256 sw_tx_timestamp(skb);
2259 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2260 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2262 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2264 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2268 * skb_checksum_complete - Calculate checksum of an entire packet
2269 * @skb: packet to process
2271 * This function calculates the checksum over the entire packet plus
2272 * the value of skb->csum. The latter can be used to supply the
2273 * checksum of a pseudo header as used by TCP/UDP. It returns the
2276 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2277 * this function can be used to verify that checksum on received
2278 * packets. In that case the function should return zero if the
2279 * checksum is correct. In particular, this function will return zero
2280 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2281 * hardware has already verified the correctness of the checksum.
2283 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2285 return skb_csum_unnecessary(skb) ?
2286 0 : __skb_checksum_complete(skb);
2289 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2290 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2291 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2293 if (nfct && atomic_dec_and_test(&nfct->use))
2294 nf_conntrack_destroy(nfct);
2296 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2299 atomic_inc(&nfct->use);
2302 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2303 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2306 atomic_inc(&skb->users);
2308 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2314 #ifdef CONFIG_BRIDGE_NETFILTER
2315 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2317 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2320 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2323 atomic_inc(&nf_bridge->use);
2325 #endif /* CONFIG_BRIDGE_NETFILTER */
2326 static inline void nf_reset(struct sk_buff *skb)
2328 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2329 nf_conntrack_put(skb->nfct);
2332 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2333 nf_conntrack_put_reasm(skb->nfct_reasm);
2334 skb->nfct_reasm = NULL;
2336 #ifdef CONFIG_BRIDGE_NETFILTER
2337 nf_bridge_put(skb->nf_bridge);
2338 skb->nf_bridge = NULL;
2342 /* Note: This doesn't put any conntrack and bridge info in dst. */
2343 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2345 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2346 dst->nfct = src->nfct;
2347 nf_conntrack_get(src->nfct);
2348 dst->nfctinfo = src->nfctinfo;
2350 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2351 dst->nfct_reasm = src->nfct_reasm;
2352 nf_conntrack_get_reasm(src->nfct_reasm);
2354 #ifdef CONFIG_BRIDGE_NETFILTER
2355 dst->nf_bridge = src->nf_bridge;
2356 nf_bridge_get(src->nf_bridge);
2360 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2362 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2363 nf_conntrack_put(dst->nfct);
2365 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2366 nf_conntrack_put_reasm(dst->nfct_reasm);
2368 #ifdef CONFIG_BRIDGE_NETFILTER
2369 nf_bridge_put(dst->nf_bridge);
2371 __nf_copy(dst, src);
2374 #ifdef CONFIG_NETWORK_SECMARK
2375 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2377 to->secmark = from->secmark;
2380 static inline void skb_init_secmark(struct sk_buff *skb)
2385 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2388 static inline void skb_init_secmark(struct sk_buff *skb)
2392 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2394 skb->queue_mapping = queue_mapping;
2397 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2399 return skb->queue_mapping;
2402 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2404 to->queue_mapping = from->queue_mapping;
2407 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2409 skb->queue_mapping = rx_queue + 1;
2412 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2414 return skb->queue_mapping - 1;
2417 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2419 return skb->queue_mapping != 0;
2422 extern u16 __skb_tx_hash(const struct net_device *dev,
2423 const struct sk_buff *skb,
2424 unsigned int num_tx_queues);
2427 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2432 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2438 static inline int skb_is_gso(const struct sk_buff *skb)
2440 return skb_shinfo(skb)->gso_size;
2443 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2445 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2448 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2450 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2452 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2453 * wanted then gso_type will be set. */
2454 struct skb_shared_info *shinfo = skb_shinfo(skb);
2455 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2456 unlikely(shinfo->gso_type == 0)) {
2457 __skb_warn_lro_forwarding(skb);
2463 static inline void skb_forward_csum(struct sk_buff *skb)
2465 /* Unfortunately we don't support this one. Any brave souls? */
2466 if (skb->ip_summed == CHECKSUM_COMPLETE)
2467 skb->ip_summed = CHECKSUM_NONE;
2471 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2472 * @skb: skb to check
2474 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2475 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2476 * use this helper, to document places where we make this assertion.
2478 static inline void skb_checksum_none_assert(struct sk_buff *skb)
2481 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2485 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2487 #endif /* __KERNEL__ */
2488 #endif /* _LINUX_SKBUFF_H */