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 #define HAVE_ALLOC_SKB /* For the drivers to know */
33 #define HAVE_ALIGNABLE_SKB /* Ditto 8) */
35 /* Don't change this without changing skb_csum_unnecessary! */
36 #define CHECKSUM_NONE 0
37 #define CHECKSUM_UNNECESSARY 1
38 #define CHECKSUM_COMPLETE 2
39 #define CHECKSUM_PARTIAL 3
41 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
42 ~(SMP_CACHE_BYTES - 1))
43 #define SKB_WITH_OVERHEAD(X) \
44 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
45 #define SKB_MAX_ORDER(X, ORDER) \
46 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
47 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
48 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
50 /* A. Checksumming of received packets by device.
52 * NONE: device failed to checksum this packet.
53 * skb->csum is undefined.
55 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
56 * skb->csum is undefined.
57 * It is bad option, but, unfortunately, many of vendors do this.
58 * Apparently with secret goal to sell you new device, when you
59 * will add new protocol to your host. F.e. IPv6. 8)
61 * COMPLETE: the most generic way. Device supplied checksum of _all_
62 * the packet as seen by netif_rx in skb->csum.
63 * NOTE: Even if device supports only some protocols, but
64 * is able to produce some skb->csum, it MUST use COMPLETE,
67 * PARTIAL: identical to the case for output below. This may occur
68 * on a packet received directly from another Linux OS, e.g.,
69 * a virtualised Linux kernel on the same host. The packet can
70 * be treated in the same way as UNNECESSARY except that on
71 * output (i.e., forwarding) the checksum must be filled in
72 * by the OS or the hardware.
74 * B. Checksumming on output.
76 * NONE: skb is checksummed by protocol or csum is not required.
78 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
79 * from skb->csum_start to the end and to record the checksum
80 * at skb->csum_start + skb->csum_offset.
82 * Device must show its capabilities in dev->features, set
83 * at device setup time.
84 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
86 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
87 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
88 * TCP/UDP over IPv4. Sigh. Vendors like this
89 * way by an unknown reason. Though, see comment above
90 * about CHECKSUM_UNNECESSARY. 8)
91 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
93 * Any questions? No questions, good. --ANK
98 struct pipe_inode_info;
100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
101 struct nf_conntrack {
106 #ifdef CONFIG_BRIDGE_NETFILTER
107 struct nf_bridge_info {
109 struct net_device *physindev;
110 struct net_device *physoutdev;
112 unsigned long data[32 / sizeof(unsigned long)];
116 struct sk_buff_head {
117 /* These two members must be first. */
118 struct sk_buff *next;
119 struct sk_buff *prev;
127 /* To allow 64K frame to be packed as single skb without frag_list */
128 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
130 typedef struct skb_frag_struct skb_frag_t;
132 struct skb_frag_struct {
138 /* This data is invariant across clones and lives at
139 * the end of the header data, ie. at skb->end.
141 struct skb_shared_info {
143 unsigned short nr_frags;
144 unsigned short gso_size;
145 /* Warning: this field is not always filled in (UFO)! */
146 unsigned short gso_segs;
147 unsigned short gso_type;
149 struct sk_buff *frag_list;
150 skb_frag_t frags[MAX_SKB_FRAGS];
153 /* We divide dataref into two halves. The higher 16 bits hold references
154 * to the payload part of skb->data. The lower 16 bits hold references to
155 * the entire skb->data. A clone of a headerless skb holds the length of
156 * the header in skb->hdr_len.
158 * All users must obey the rule that the skb->data reference count must be
159 * greater than or equal to the payload reference count.
161 * Holding a reference to the payload part means that the user does not
162 * care about modifications to the header part of skb->data.
164 #define SKB_DATAREF_SHIFT 16
165 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
169 SKB_FCLONE_UNAVAILABLE,
175 SKB_GSO_TCPV4 = 1 << 0,
176 SKB_GSO_UDP = 1 << 1,
178 /* This indicates the skb is from an untrusted source. */
179 SKB_GSO_DODGY = 1 << 2,
181 /* This indicates the tcp segment has CWR set. */
182 SKB_GSO_TCP_ECN = 1 << 3,
184 SKB_GSO_TCPV6 = 1 << 4,
187 #if BITS_PER_LONG > 32
188 #define NET_SKBUFF_DATA_USES_OFFSET 1
191 #ifdef NET_SKBUFF_DATA_USES_OFFSET
192 typedef unsigned int sk_buff_data_t;
194 typedef unsigned char *sk_buff_data_t;
198 * struct sk_buff - socket buffer
199 * @next: Next buffer in list
200 * @prev: Previous buffer in list
201 * @sk: Socket we are owned by
202 * @tstamp: Time we arrived
203 * @dev: Device we arrived on/are leaving by
204 * @transport_header: Transport layer header
205 * @network_header: Network layer header
206 * @mac_header: Link layer header
207 * @dst: destination entry
208 * @sp: the security path, used for xfrm
209 * @cb: Control buffer. Free for use by every layer. Put private vars here
210 * @len: Length of actual data
211 * @data_len: Data length
212 * @mac_len: Length of link layer header
213 * @hdr_len: writable header length of cloned skb
214 * @csum: Checksum (must include start/offset pair)
215 * @csum_start: Offset from skb->head where checksumming should start
216 * @csum_offset: Offset from csum_start where checksum should be stored
217 * @local_df: allow local fragmentation
218 * @cloned: Head may be cloned (check refcnt to be sure)
219 * @nohdr: Payload reference only, must not modify header
220 * @pkt_type: Packet class
221 * @fclone: skbuff clone status
222 * @ip_summed: Driver fed us an IP checksum
223 * @priority: Packet queueing priority
224 * @users: User count - see {datagram,tcp}.c
225 * @protocol: Packet protocol from driver
226 * @truesize: Buffer size
227 * @head: Head of buffer
228 * @data: Data head pointer
229 * @tail: Tail pointer
231 * @destructor: Destruct function
232 * @mark: Generic packet mark
233 * @nfct: Associated connection, if any
234 * @ipvs_property: skbuff is owned by ipvs
235 * @peeked: this packet has been seen already, so stats have been
236 * done for it, don't do them again
237 * @nf_trace: netfilter packet trace flag
238 * @nfctinfo: Relationship of this skb to the connection
239 * @nfct_reasm: netfilter conntrack re-assembly pointer
240 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
241 * @iif: ifindex of device we arrived on
242 * @queue_mapping: Queue mapping for multiqueue devices
243 * @tc_index: Traffic control index
244 * @tc_verd: traffic control verdict
245 * @ndisc_nodetype: router type (from link layer)
246 * @dma_cookie: a cookie to one of several possible DMA operations
247 * done by skb DMA functions
248 * @secmark: security marking
252 /* These two members must be first. */
253 struct sk_buff *next;
254 struct sk_buff *prev;
258 struct net_device *dev;
261 struct dst_entry *dst;
262 struct rtable *rtable;
267 * This is the control buffer. It is free to use for every
268 * layer. Please put your private variables there. If you
269 * want to keep them across layers you have to do a skb_clone()
270 * first. This is owned by whoever has the skb queued ATM.
298 void (*destructor)(struct sk_buff *skb);
299 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
300 struct nf_conntrack *nfct;
301 struct sk_buff *nfct_reasm;
303 #ifdef CONFIG_BRIDGE_NETFILTER
304 struct nf_bridge_info *nf_bridge;
309 #ifdef CONFIG_NET_SCHED
310 __u16 tc_index; /* traffic control index */
311 #ifdef CONFIG_NET_CLS_ACT
312 __u16 tc_verd; /* traffic control verdict */
315 #ifdef CONFIG_IPV6_NDISC_NODETYPE
316 __u8 ndisc_nodetype:2;
320 #ifdef CONFIG_NET_DMA
321 dma_cookie_t dma_cookie;
323 #ifdef CONFIG_NETWORK_SECMARK
329 sk_buff_data_t transport_header;
330 sk_buff_data_t network_header;
331 sk_buff_data_t mac_header;
332 /* These elements must be at the end, see alloc_skb() for details. */
337 unsigned int truesize;
343 * Handling routines are only of interest to the kernel
345 #include <linux/slab.h>
347 #include <asm/system.h>
349 extern void kfree_skb(struct sk_buff *skb);
350 extern void __kfree_skb(struct sk_buff *skb);
351 extern struct sk_buff *__alloc_skb(unsigned int size,
352 gfp_t priority, int fclone, int node);
353 static inline struct sk_buff *alloc_skb(unsigned int size,
356 return __alloc_skb(size, priority, 0, -1);
359 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
362 return __alloc_skb(size, priority, 1, -1);
365 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
366 extern struct sk_buff *skb_clone(struct sk_buff *skb,
368 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
370 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
372 extern int pskb_expand_head(struct sk_buff *skb,
373 int nhead, int ntail,
375 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
376 unsigned int headroom);
377 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
378 int newheadroom, int newtailroom,
380 extern int skb_to_sgvec(struct sk_buff *skb,
381 struct scatterlist *sg, int offset,
383 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
384 struct sk_buff **trailer);
385 extern int skb_pad(struct sk_buff *skb, int pad);
386 #define dev_kfree_skb(a) kfree_skb(a)
387 extern void skb_over_panic(struct sk_buff *skb, int len,
389 extern void skb_under_panic(struct sk_buff *skb, int len,
391 extern void skb_truesize_bug(struct sk_buff *skb);
393 static inline void skb_truesize_check(struct sk_buff *skb)
395 int len = sizeof(struct sk_buff) + skb->len;
397 if (unlikely((int)skb->truesize < len))
398 skb_truesize_bug(skb);
401 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
402 int getfrag(void *from, char *to, int offset,
403 int len,int odd, struct sk_buff *skb),
404 void *from, int length);
411 __u32 stepped_offset;
412 struct sk_buff *root_skb;
413 struct sk_buff *cur_skb;
417 extern void skb_prepare_seq_read(struct sk_buff *skb,
418 unsigned int from, unsigned int to,
419 struct skb_seq_state *st);
420 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
421 struct skb_seq_state *st);
422 extern void skb_abort_seq_read(struct skb_seq_state *st);
424 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
425 unsigned int to, struct ts_config *config,
426 struct ts_state *state);
428 #ifdef NET_SKBUFF_DATA_USES_OFFSET
429 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
431 return skb->head + skb->end;
434 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
441 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
444 * skb_queue_empty - check if a queue is empty
447 * Returns true if the queue is empty, false otherwise.
449 static inline int skb_queue_empty(const struct sk_buff_head *list)
451 return list->next == (struct sk_buff *)list;
455 * skb_get - reference buffer
456 * @skb: buffer to reference
458 * Makes another reference to a socket buffer and returns a pointer
461 static inline struct sk_buff *skb_get(struct sk_buff *skb)
463 atomic_inc(&skb->users);
468 * If users == 1, we are the only owner and are can avoid redundant
473 * skb_cloned - is the buffer a clone
474 * @skb: buffer to check
476 * Returns true if the buffer was generated with skb_clone() and is
477 * one of multiple shared copies of the buffer. Cloned buffers are
478 * shared data so must not be written to under normal circumstances.
480 static inline int skb_cloned(const struct sk_buff *skb)
482 return skb->cloned &&
483 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
487 * skb_header_cloned - is the header a clone
488 * @skb: buffer to check
490 * Returns true if modifying the header part of the buffer requires
491 * the data to be copied.
493 static inline int skb_header_cloned(const struct sk_buff *skb)
500 dataref = atomic_read(&skb_shinfo(skb)->dataref);
501 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
506 * skb_header_release - release reference to header
507 * @skb: buffer to operate on
509 * Drop a reference to the header part of the buffer. This is done
510 * by acquiring a payload reference. You must not read from the header
511 * part of skb->data after this.
513 static inline void skb_header_release(struct sk_buff *skb)
517 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
521 * skb_shared - is the buffer shared
522 * @skb: buffer to check
524 * Returns true if more than one person has a reference to this
527 static inline int skb_shared(const struct sk_buff *skb)
529 return atomic_read(&skb->users) != 1;
533 * skb_share_check - check if buffer is shared and if so clone it
534 * @skb: buffer to check
535 * @pri: priority for memory allocation
537 * If the buffer is shared the buffer is cloned and the old copy
538 * drops a reference. A new clone with a single reference is returned.
539 * If the buffer is not shared the original buffer is returned. When
540 * being called from interrupt status or with spinlocks held pri must
543 * NULL is returned on a memory allocation failure.
545 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
548 might_sleep_if(pri & __GFP_WAIT);
549 if (skb_shared(skb)) {
550 struct sk_buff *nskb = skb_clone(skb, pri);
558 * Copy shared buffers into a new sk_buff. We effectively do COW on
559 * packets to handle cases where we have a local reader and forward
560 * and a couple of other messy ones. The normal one is tcpdumping
561 * a packet thats being forwarded.
565 * skb_unshare - make a copy of a shared buffer
566 * @skb: buffer to check
567 * @pri: priority for memory allocation
569 * If the socket buffer is a clone then this function creates a new
570 * copy of the data, drops a reference count on the old copy and returns
571 * the new copy with the reference count at 1. If the buffer is not a clone
572 * the original buffer is returned. When called with a spinlock held or
573 * from interrupt state @pri must be %GFP_ATOMIC
575 * %NULL is returned on a memory allocation failure.
577 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
580 might_sleep_if(pri & __GFP_WAIT);
581 if (skb_cloned(skb)) {
582 struct sk_buff *nskb = skb_copy(skb, pri);
583 kfree_skb(skb); /* Free our shared copy */
591 * @list_: list to peek at
593 * Peek an &sk_buff. Unlike most other operations you _MUST_
594 * be careful with this one. A peek leaves the buffer on the
595 * list and someone else may run off with it. You must hold
596 * the appropriate locks or have a private queue to do this.
598 * Returns %NULL for an empty list or a pointer to the head element.
599 * The reference count is not incremented and the reference is therefore
600 * volatile. Use with caution.
602 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
604 struct sk_buff *list = ((struct sk_buff *)list_)->next;
605 if (list == (struct sk_buff *)list_)
612 * @list_: list to peek at
614 * Peek an &sk_buff. Unlike most other operations you _MUST_
615 * be careful with this one. A peek leaves the buffer on the
616 * list and someone else may run off with it. You must hold
617 * the appropriate locks or have a private queue to do this.
619 * Returns %NULL for an empty list or a pointer to the tail element.
620 * The reference count is not incremented and the reference is therefore
621 * volatile. Use with caution.
623 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
625 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
626 if (list == (struct sk_buff *)list_)
632 * skb_queue_len - get queue length
633 * @list_: list to measure
635 * Return the length of an &sk_buff queue.
637 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
643 * This function creates a split out lock class for each invocation;
644 * this is needed for now since a whole lot of users of the skb-queue
645 * infrastructure in drivers have different locking usage (in hardirq)
646 * than the networking core (in softirq only). In the long run either the
647 * network layer or drivers should need annotation to consolidate the
648 * main types of usage into 3 classes.
650 static inline void skb_queue_head_init(struct sk_buff_head *list)
652 spin_lock_init(&list->lock);
653 list->prev = list->next = (struct sk_buff *)list;
657 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
658 struct lock_class_key *class)
660 skb_queue_head_init(list);
661 lockdep_set_class(&list->lock, class);
665 * Insert an sk_buff on a list.
667 * The "__skb_xxxx()" functions are the non-atomic ones that
668 * can only be called with interrupts disabled.
670 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
671 static inline void __skb_insert(struct sk_buff *newsk,
672 struct sk_buff *prev, struct sk_buff *next,
673 struct sk_buff_head *list)
677 next->prev = prev->next = newsk;
682 * __skb_queue_after - queue a buffer at the list head
684 * @prev: place after this buffer
685 * @newsk: buffer to queue
687 * Queue a buffer int the middle of a list. This function takes no locks
688 * and you must therefore hold required locks before calling it.
690 * A buffer cannot be placed on two lists at the same time.
692 static inline void __skb_queue_after(struct sk_buff_head *list,
693 struct sk_buff *prev,
694 struct sk_buff *newsk)
696 __skb_insert(newsk, prev, prev->next, list);
699 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
700 struct sk_buff_head *list);
702 static inline void __skb_queue_before(struct sk_buff_head *list,
703 struct sk_buff *next,
704 struct sk_buff *newsk)
706 __skb_insert(newsk, next->prev, next, list);
710 * __skb_queue_head - queue a buffer at the list head
712 * @newsk: buffer to queue
714 * Queue a buffer at the start of a list. This function takes no locks
715 * and you must therefore hold required locks before calling it.
717 * A buffer cannot be placed on two lists at the same time.
719 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
720 static inline void __skb_queue_head(struct sk_buff_head *list,
721 struct sk_buff *newsk)
723 __skb_queue_after(list, (struct sk_buff *)list, newsk);
727 * __skb_queue_tail - queue a buffer at the list tail
729 * @newsk: buffer to queue
731 * Queue a buffer at the end of a list. This function takes no locks
732 * and you must therefore hold required locks before calling it.
734 * A buffer cannot be placed on two lists at the same time.
736 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
737 static inline void __skb_queue_tail(struct sk_buff_head *list,
738 struct sk_buff *newsk)
740 __skb_queue_before(list, (struct sk_buff *)list, newsk);
744 * remove sk_buff from list. _Must_ be called atomically, and with
747 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
748 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
750 struct sk_buff *next, *prev;
755 skb->next = skb->prev = NULL;
761 * __skb_dequeue - remove from the head of the queue
762 * @list: list to dequeue from
764 * Remove the head of the list. This function does not take any locks
765 * so must be used with appropriate locks held only. The head item is
766 * returned or %NULL if the list is empty.
768 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
769 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
771 struct sk_buff *skb = skb_peek(list);
773 __skb_unlink(skb, list);
778 * __skb_dequeue_tail - remove from the tail of the queue
779 * @list: list to dequeue from
781 * Remove the tail of the list. This function does not take any locks
782 * so must be used with appropriate locks held only. The tail item is
783 * returned or %NULL if the list is empty.
785 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
786 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
788 struct sk_buff *skb = skb_peek_tail(list);
790 __skb_unlink(skb, list);
795 static inline int skb_is_nonlinear(const struct sk_buff *skb)
797 return skb->data_len;
800 static inline unsigned int skb_headlen(const struct sk_buff *skb)
802 return skb->len - skb->data_len;
805 static inline int skb_pagelen(const struct sk_buff *skb)
809 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
810 len += skb_shinfo(skb)->frags[i].size;
811 return len + skb_headlen(skb);
814 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
815 struct page *page, int off, int size)
817 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
820 frag->page_offset = off;
822 skb_shinfo(skb)->nr_frags = i + 1;
825 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
826 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
827 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
829 #ifdef NET_SKBUFF_DATA_USES_OFFSET
830 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
832 return skb->head + skb->tail;
835 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
837 skb->tail = skb->data - skb->head;
840 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
842 skb_reset_tail_pointer(skb);
845 #else /* NET_SKBUFF_DATA_USES_OFFSET */
846 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
851 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
853 skb->tail = skb->data;
856 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
858 skb->tail = skb->data + offset;
861 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
864 * Add data to an sk_buff
866 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
867 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
869 unsigned char *tmp = skb_tail_pointer(skb);
870 SKB_LINEAR_ASSERT(skb);
876 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
877 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
884 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
885 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
888 BUG_ON(skb->len < skb->data_len);
889 return skb->data += len;
892 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
894 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
896 if (len > skb_headlen(skb) &&
897 !__pskb_pull_tail(skb, len-skb_headlen(skb)))
900 return skb->data += len;
903 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
905 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
908 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
910 if (likely(len <= skb_headlen(skb)))
912 if (unlikely(len > skb->len))
914 return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL;
918 * skb_headroom - bytes at buffer head
919 * @skb: buffer to check
921 * Return the number of bytes of free space at the head of an &sk_buff.
923 static inline unsigned int skb_headroom(const struct sk_buff *skb)
925 return skb->data - skb->head;
929 * skb_tailroom - bytes at buffer end
930 * @skb: buffer to check
932 * Return the number of bytes of free space at the tail of an sk_buff
934 static inline int skb_tailroom(const struct sk_buff *skb)
936 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
940 * skb_reserve - adjust headroom
941 * @skb: buffer to alter
942 * @len: bytes to move
944 * Increase the headroom of an empty &sk_buff by reducing the tail
945 * room. This is only allowed for an empty buffer.
947 static inline void skb_reserve(struct sk_buff *skb, int len)
953 #ifdef NET_SKBUFF_DATA_USES_OFFSET
954 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
956 return skb->head + skb->transport_header;
959 static inline void skb_reset_transport_header(struct sk_buff *skb)
961 skb->transport_header = skb->data - skb->head;
964 static inline void skb_set_transport_header(struct sk_buff *skb,
967 skb_reset_transport_header(skb);
968 skb->transport_header += offset;
971 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
973 return skb->head + skb->network_header;
976 static inline void skb_reset_network_header(struct sk_buff *skb)
978 skb->network_header = skb->data - skb->head;
981 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
983 skb_reset_network_header(skb);
984 skb->network_header += offset;
987 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
989 return skb->head + skb->mac_header;
992 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
994 return skb->mac_header != ~0U;
997 static inline void skb_reset_mac_header(struct sk_buff *skb)
999 skb->mac_header = skb->data - skb->head;
1002 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1004 skb_reset_mac_header(skb);
1005 skb->mac_header += offset;
1008 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1010 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1012 return skb->transport_header;
1015 static inline void skb_reset_transport_header(struct sk_buff *skb)
1017 skb->transport_header = skb->data;
1020 static inline void skb_set_transport_header(struct sk_buff *skb,
1023 skb->transport_header = skb->data + offset;
1026 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1028 return skb->network_header;
1031 static inline void skb_reset_network_header(struct sk_buff *skb)
1033 skb->network_header = skb->data;
1036 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1038 skb->network_header = skb->data + offset;
1041 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1043 return skb->mac_header;
1046 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1048 return skb->mac_header != NULL;
1051 static inline void skb_reset_mac_header(struct sk_buff *skb)
1053 skb->mac_header = skb->data;
1056 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1058 skb->mac_header = skb->data + offset;
1060 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1062 static inline int skb_transport_offset(const struct sk_buff *skb)
1064 return skb_transport_header(skb) - skb->data;
1067 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1069 return skb->transport_header - skb->network_header;
1072 static inline int skb_network_offset(const struct sk_buff *skb)
1074 return skb_network_header(skb) - skb->data;
1078 * CPUs often take a performance hit when accessing unaligned memory
1079 * locations. The actual performance hit varies, it can be small if the
1080 * hardware handles it or large if we have to take an exception and fix it
1083 * Since an ethernet header is 14 bytes network drivers often end up with
1084 * the IP header at an unaligned offset. The IP header can be aligned by
1085 * shifting the start of the packet by 2 bytes. Drivers should do this
1088 * skb_reserve(NET_IP_ALIGN);
1090 * The downside to this alignment of the IP header is that the DMA is now
1091 * unaligned. On some architectures the cost of an unaligned DMA is high
1092 * and this cost outweighs the gains made by aligning the IP header.
1094 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1097 #ifndef NET_IP_ALIGN
1098 #define NET_IP_ALIGN 2
1102 * The networking layer reserves some headroom in skb data (via
1103 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1104 * the header has to grow. In the default case, if the header has to grow
1105 * 16 bytes or less we avoid the reallocation.
1107 * Unfortunately this headroom changes the DMA alignment of the resulting
1108 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1109 * on some architectures. An architecture can override this value,
1110 * perhaps setting it to a cacheline in size (since that will maintain
1111 * cacheline alignment of the DMA). It must be a power of 2.
1113 * Various parts of the networking layer expect at least 16 bytes of
1114 * headroom, you should not reduce this.
1117 #define NET_SKB_PAD 16
1120 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1122 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1124 if (unlikely(skb->data_len)) {
1129 skb_set_tail_pointer(skb, len);
1132 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1134 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1137 return ___pskb_trim(skb, len);
1138 __skb_trim(skb, len);
1142 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1144 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1148 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1149 * @skb: buffer to alter
1152 * This is identical to pskb_trim except that the caller knows that
1153 * the skb is not cloned so we should never get an error due to out-
1156 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1158 int err = pskb_trim(skb, len);
1163 * skb_orphan - orphan a buffer
1164 * @skb: buffer to orphan
1166 * If a buffer currently has an owner then we call the owner's
1167 * destructor function and make the @skb unowned. The buffer continues
1168 * to exist but is no longer charged to its former owner.
1170 static inline void skb_orphan(struct sk_buff *skb)
1172 if (skb->destructor)
1173 skb->destructor(skb);
1174 skb->destructor = NULL;
1179 * __skb_queue_purge - empty a list
1180 * @list: list to empty
1182 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1183 * the list and one reference dropped. This function does not take the
1184 * list lock and the caller must hold the relevant locks to use it.
1186 extern void skb_queue_purge(struct sk_buff_head *list);
1187 static inline void __skb_queue_purge(struct sk_buff_head *list)
1189 struct sk_buff *skb;
1190 while ((skb = __skb_dequeue(list)) != NULL)
1195 * __dev_alloc_skb - allocate an skbuff for receiving
1196 * @length: length to allocate
1197 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1199 * Allocate a new &sk_buff and assign it a usage count of one. The
1200 * buffer has unspecified headroom built in. Users should allocate
1201 * the headroom they think they need without accounting for the
1202 * built in space. The built in space is used for optimisations.
1204 * %NULL is returned if there is no free memory.
1206 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1209 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1211 skb_reserve(skb, NET_SKB_PAD);
1215 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1217 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1218 unsigned int length, gfp_t gfp_mask);
1221 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1222 * @dev: network device to receive on
1223 * @length: length to allocate
1225 * Allocate a new &sk_buff and assign it a usage count of one. The
1226 * buffer has unspecified headroom built in. Users should allocate
1227 * the headroom they think they need without accounting for the
1228 * built in space. The built in space is used for optimisations.
1230 * %NULL is returned if there is no free memory. Although this function
1231 * allocates memory it can be called from an interrupt.
1233 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1234 unsigned int length)
1236 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1240 * skb_clone_writable - is the header of a clone writable
1241 * @skb: buffer to check
1242 * @len: length up to which to write
1244 * Returns true if modifying the header part of the cloned buffer
1245 * does not requires the data to be copied.
1247 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1249 return !skb_header_cloned(skb) &&
1250 skb_headroom(skb) + len <= skb->hdr_len;
1253 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1258 if (headroom < NET_SKB_PAD)
1259 headroom = NET_SKB_PAD;
1260 if (headroom > skb_headroom(skb))
1261 delta = headroom - skb_headroom(skb);
1263 if (delta || cloned)
1264 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1270 * skb_cow - copy header of skb when it is required
1271 * @skb: buffer to cow
1272 * @headroom: needed headroom
1274 * If the skb passed lacks sufficient headroom or its data part
1275 * is shared, data is reallocated. If reallocation fails, an error
1276 * is returned and original skb is not changed.
1278 * The result is skb with writable area skb->head...skb->tail
1279 * and at least @headroom of space at head.
1281 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1283 return __skb_cow(skb, headroom, skb_cloned(skb));
1287 * skb_cow_head - skb_cow but only making the head writable
1288 * @skb: buffer to cow
1289 * @headroom: needed headroom
1291 * This function is identical to skb_cow except that we replace the
1292 * skb_cloned check by skb_header_cloned. It should be used when
1293 * you only need to push on some header and do not need to modify
1296 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1298 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1302 * skb_padto - pad an skbuff up to a minimal size
1303 * @skb: buffer to pad
1304 * @len: minimal length
1306 * Pads up a buffer to ensure the trailing bytes exist and are
1307 * blanked. If the buffer already contains sufficient data it
1308 * is untouched. Otherwise it is extended. Returns zero on
1309 * success. The skb is freed on error.
1312 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1314 unsigned int size = skb->len;
1315 if (likely(size >= len))
1317 return skb_pad(skb, len-size);
1320 static inline int skb_add_data(struct sk_buff *skb,
1321 char __user *from, int copy)
1323 const int off = skb->len;
1325 if (skb->ip_summed == CHECKSUM_NONE) {
1327 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1330 skb->csum = csum_block_add(skb->csum, csum, off);
1333 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1336 __skb_trim(skb, off);
1340 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1341 struct page *page, int off)
1344 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1346 return page == frag->page &&
1347 off == frag->page_offset + frag->size;
1352 static inline int __skb_linearize(struct sk_buff *skb)
1354 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1358 * skb_linearize - convert paged skb to linear one
1359 * @skb: buffer to linarize
1361 * If there is no free memory -ENOMEM is returned, otherwise zero
1362 * is returned and the old skb data released.
1364 static inline int skb_linearize(struct sk_buff *skb)
1366 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1370 * skb_linearize_cow - make sure skb is linear and writable
1371 * @skb: buffer to process
1373 * If there is no free memory -ENOMEM is returned, otherwise zero
1374 * is returned and the old skb data released.
1376 static inline int skb_linearize_cow(struct sk_buff *skb)
1378 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1379 __skb_linearize(skb) : 0;
1383 * skb_postpull_rcsum - update checksum for received skb after pull
1384 * @skb: buffer to update
1385 * @start: start of data before pull
1386 * @len: length of data pulled
1388 * After doing a pull on a received packet, you need to call this to
1389 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1390 * CHECKSUM_NONE so that it can be recomputed from scratch.
1393 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1394 const void *start, unsigned int len)
1396 if (skb->ip_summed == CHECKSUM_COMPLETE)
1397 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1400 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1403 * pskb_trim_rcsum - trim received skb and update checksum
1404 * @skb: buffer to trim
1407 * This is exactly the same as pskb_trim except that it ensures the
1408 * checksum of received packets are still valid after the operation.
1411 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1413 if (likely(len >= skb->len))
1415 if (skb->ip_summed == CHECKSUM_COMPLETE)
1416 skb->ip_summed = CHECKSUM_NONE;
1417 return __pskb_trim(skb, len);
1420 #define skb_queue_walk(queue, skb) \
1421 for (skb = (queue)->next; \
1422 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1425 #define skb_queue_walk_safe(queue, skb, tmp) \
1426 for (skb = (queue)->next, tmp = skb->next; \
1427 skb != (struct sk_buff *)(queue); \
1428 skb = tmp, tmp = skb->next)
1430 #define skb_queue_reverse_walk(queue, skb) \
1431 for (skb = (queue)->prev; \
1432 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1436 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1437 int *peeked, int *err);
1438 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1439 int noblock, int *err);
1440 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1441 struct poll_table_struct *wait);
1442 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1443 int offset, struct iovec *to,
1445 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1448 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1449 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1450 unsigned int flags);
1451 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1452 int len, __wsum csum);
1453 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1455 extern int skb_store_bits(struct sk_buff *skb, int offset,
1456 const void *from, int len);
1457 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1458 int offset, u8 *to, int len,
1460 extern int skb_splice_bits(struct sk_buff *skb,
1461 unsigned int offset,
1462 struct pipe_inode_info *pipe,
1464 unsigned int flags);
1465 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1466 extern void skb_split(struct sk_buff *skb,
1467 struct sk_buff *skb1, const u32 len);
1469 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1471 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1472 int len, void *buffer)
1474 int hlen = skb_headlen(skb);
1476 if (hlen - offset >= len)
1477 return skb->data + offset;
1479 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1485 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1487 const unsigned int len)
1489 memcpy(to, skb->data, len);
1492 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1493 const int offset, void *to,
1494 const unsigned int len)
1496 memcpy(to, skb->data + offset, len);
1499 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1501 const unsigned int len)
1503 memcpy(skb->data, from, len);
1506 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1509 const unsigned int len)
1511 memcpy(skb->data + offset, from, len);
1514 extern void skb_init(void);
1517 * skb_get_timestamp - get timestamp from a skb
1518 * @skb: skb to get stamp from
1519 * @stamp: pointer to struct timeval to store stamp in
1521 * Timestamps are stored in the skb as offsets to a base timestamp.
1522 * This function converts the offset back to a struct timeval and stores
1525 static inline void skb_get_timestamp(const struct sk_buff *skb, struct timeval *stamp)
1527 *stamp = ktime_to_timeval(skb->tstamp);
1530 static inline void __net_timestamp(struct sk_buff *skb)
1532 skb->tstamp = ktime_get_real();
1535 static inline ktime_t net_timedelta(ktime_t t)
1537 return ktime_sub(ktime_get_real(), t);
1540 static inline ktime_t net_invalid_timestamp(void)
1542 return ktime_set(0, 0);
1545 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1546 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1548 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1550 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1554 * skb_checksum_complete - Calculate checksum of an entire packet
1555 * @skb: packet to process
1557 * This function calculates the checksum over the entire packet plus
1558 * the value of skb->csum. The latter can be used to supply the
1559 * checksum of a pseudo header as used by TCP/UDP. It returns the
1562 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1563 * this function can be used to verify that checksum on received
1564 * packets. In that case the function should return zero if the
1565 * checksum is correct. In particular, this function will return zero
1566 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1567 * hardware has already verified the correctness of the checksum.
1569 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1571 return skb_csum_unnecessary(skb) ?
1572 0 : __skb_checksum_complete(skb);
1575 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1576 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1577 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1579 if (nfct && atomic_dec_and_test(&nfct->use))
1580 nf_conntrack_destroy(nfct);
1582 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1585 atomic_inc(&nfct->use);
1587 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1590 atomic_inc(&skb->users);
1592 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1598 #ifdef CONFIG_BRIDGE_NETFILTER
1599 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1601 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1604 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1607 atomic_inc(&nf_bridge->use);
1609 #endif /* CONFIG_BRIDGE_NETFILTER */
1610 static inline void nf_reset(struct sk_buff *skb)
1612 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1613 nf_conntrack_put(skb->nfct);
1615 nf_conntrack_put_reasm(skb->nfct_reasm);
1616 skb->nfct_reasm = NULL;
1618 #ifdef CONFIG_BRIDGE_NETFILTER
1619 nf_bridge_put(skb->nf_bridge);
1620 skb->nf_bridge = NULL;
1624 /* Note: This doesn't put any conntrack and bridge info in dst. */
1625 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1627 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1628 dst->nfct = src->nfct;
1629 nf_conntrack_get(src->nfct);
1630 dst->nfctinfo = src->nfctinfo;
1631 dst->nfct_reasm = src->nfct_reasm;
1632 nf_conntrack_get_reasm(src->nfct_reasm);
1634 #ifdef CONFIG_BRIDGE_NETFILTER
1635 dst->nf_bridge = src->nf_bridge;
1636 nf_bridge_get(src->nf_bridge);
1640 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1642 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1643 nf_conntrack_put(dst->nfct);
1644 nf_conntrack_put_reasm(dst->nfct_reasm);
1646 #ifdef CONFIG_BRIDGE_NETFILTER
1647 nf_bridge_put(dst->nf_bridge);
1649 __nf_copy(dst, src);
1652 #ifdef CONFIG_NETWORK_SECMARK
1653 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1655 to->secmark = from->secmark;
1658 static inline void skb_init_secmark(struct sk_buff *skb)
1663 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1666 static inline void skb_init_secmark(struct sk_buff *skb)
1670 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1672 skb->queue_mapping = queue_mapping;
1675 static inline u16 skb_get_queue_mapping(struct sk_buff *skb)
1677 return skb->queue_mapping;
1680 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1682 to->queue_mapping = from->queue_mapping;
1685 static inline int skb_is_gso(const struct sk_buff *skb)
1687 return skb_shinfo(skb)->gso_size;
1690 static inline int skb_is_gso_v6(const struct sk_buff *skb)
1692 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
1695 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
1697 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
1699 /* LRO sets gso_size but not gso_type, whereas if GSO is really
1700 * wanted then gso_type will be set. */
1701 struct skb_shared_info *shinfo = skb_shinfo(skb);
1702 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
1703 __skb_warn_lro_forwarding(skb);
1709 static inline void skb_forward_csum(struct sk_buff *skb)
1711 /* Unfortunately we don't support this one. Any brave souls? */
1712 if (skb->ip_summed == CHECKSUM_COMPLETE)
1713 skb->ip_summed = CHECKSUM_NONE;
1716 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
1717 #endif /* __KERNEL__ */
1718 #endif /* _LINUX_SKBUFF_H */