net: Discard and warn about LRO'd skbs received for forwarding
[linux-2.6/verdex.git] / include / linux / skbuff.h
blob2220b9e2dab095b6c2c0bea11fe1e0f4417145b4
1 /*
2 * Definitions for the 'struct sk_buff' memory handlers.
4 * Authors:
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,
65 * not UNNECESSARY.
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
85 * everything.
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
96 struct net_device;
97 struct scatterlist;
98 struct pipe_inode_info;
100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
101 struct nf_conntrack {
102 atomic_t use;
104 #endif
106 #ifdef CONFIG_BRIDGE_NETFILTER
107 struct nf_bridge_info {
108 atomic_t use;
109 struct net_device *physindev;
110 struct net_device *physoutdev;
111 unsigned int mask;
112 unsigned long data[32 / sizeof(unsigned long)];
114 #endif
116 struct sk_buff_head {
117 /* These two members must be first. */
118 struct sk_buff *next;
119 struct sk_buff *prev;
121 __u32 qlen;
122 spinlock_t lock;
125 struct sk_buff;
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 {
133 struct page *page;
134 __u32 page_offset;
135 __u32 size;
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 {
142 atomic_t dataref;
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;
148 __be32 ip6_frag_id;
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)
168 enum {
169 SKB_FCLONE_UNAVAILABLE,
170 SKB_FCLONE_ORIG,
171 SKB_FCLONE_CLONE,
174 enum {
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
189 #endif
191 #ifdef NET_SKBUFF_DATA_USES_OFFSET
192 typedef unsigned int sk_buff_data_t;
193 #else
194 typedef unsigned char *sk_buff_data_t;
195 #endif
197 /**
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
230 * @end: End 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
251 struct sk_buff {
252 /* These two members must be first. */
253 struct sk_buff *next;
254 struct sk_buff *prev;
256 struct sock *sk;
257 ktime_t tstamp;
258 struct net_device *dev;
260 union {
261 struct dst_entry *dst;
262 struct rtable *rtable;
264 struct sec_path *sp;
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.
272 char cb[48];
274 unsigned int len,
275 data_len;
276 __u16 mac_len,
277 hdr_len;
278 union {
279 __wsum csum;
280 struct {
281 __u16 csum_start;
282 __u16 csum_offset;
285 __u32 priority;
286 __u8 local_df:1,
287 cloned:1,
288 ip_summed:2,
289 nohdr:1,
290 nfctinfo:3;
291 __u8 pkt_type:3,
292 fclone:2,
293 ipvs_property:1,
294 peeked:1,
295 nf_trace:1;
296 __be16 protocol;
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;
302 #endif
303 #ifdef CONFIG_BRIDGE_NETFILTER
304 struct nf_bridge_info *nf_bridge;
305 #endif
307 int iif;
308 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
309 __u16 queue_mapping;
310 #endif
311 #ifdef CONFIG_NET_SCHED
312 __u16 tc_index; /* traffic control index */
313 #ifdef CONFIG_NET_CLS_ACT
314 __u16 tc_verd; /* traffic control verdict */
315 #endif
316 #endif
317 #ifdef CONFIG_IPV6_NDISC_NODETYPE
318 __u8 ndisc_nodetype:2;
319 #endif
320 /* 14 bit hole */
322 #ifdef CONFIG_NET_DMA
323 dma_cookie_t dma_cookie;
324 #endif
325 #ifdef CONFIG_NETWORK_SECMARK
326 __u32 secmark;
327 #endif
329 __u32 mark;
331 sk_buff_data_t transport_header;
332 sk_buff_data_t network_header;
333 sk_buff_data_t mac_header;
334 /* These elements must be at the end, see alloc_skb() for details. */
335 sk_buff_data_t tail;
336 sk_buff_data_t end;
337 unsigned char *head,
338 *data;
339 unsigned int truesize;
340 atomic_t users;
343 #ifdef __KERNEL__
345 * Handling routines are only of interest to the kernel
347 #include <linux/slab.h>
349 #include <asm/system.h>
351 extern void kfree_skb(struct sk_buff *skb);
352 extern void __kfree_skb(struct sk_buff *skb);
353 extern struct sk_buff *__alloc_skb(unsigned int size,
354 gfp_t priority, int fclone, int node);
355 static inline struct sk_buff *alloc_skb(unsigned int size,
356 gfp_t priority)
358 return __alloc_skb(size, priority, 0, -1);
361 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
362 gfp_t priority)
364 return __alloc_skb(size, priority, 1, -1);
367 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
368 extern struct sk_buff *skb_clone(struct sk_buff *skb,
369 gfp_t priority);
370 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
371 gfp_t priority);
372 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
373 gfp_t gfp_mask);
374 extern int pskb_expand_head(struct sk_buff *skb,
375 int nhead, int ntail,
376 gfp_t gfp_mask);
377 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
378 unsigned int headroom);
379 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
380 int newheadroom, int newtailroom,
381 gfp_t priority);
382 extern int skb_to_sgvec(struct sk_buff *skb,
383 struct scatterlist *sg, int offset,
384 int len);
385 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
386 struct sk_buff **trailer);
387 extern int skb_pad(struct sk_buff *skb, int pad);
388 #define dev_kfree_skb(a) kfree_skb(a)
389 extern void skb_over_panic(struct sk_buff *skb, int len,
390 void *here);
391 extern void skb_under_panic(struct sk_buff *skb, int len,
392 void *here);
393 extern void skb_truesize_bug(struct sk_buff *skb);
395 static inline void skb_truesize_check(struct sk_buff *skb)
397 int len = sizeof(struct sk_buff) + skb->len;
399 if (unlikely((int)skb->truesize < len))
400 skb_truesize_bug(skb);
403 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
404 int getfrag(void *from, char *to, int offset,
405 int len,int odd, struct sk_buff *skb),
406 void *from, int length);
408 struct skb_seq_state
410 __u32 lower_offset;
411 __u32 upper_offset;
412 __u32 frag_idx;
413 __u32 stepped_offset;
414 struct sk_buff *root_skb;
415 struct sk_buff *cur_skb;
416 __u8 *frag_data;
419 extern void skb_prepare_seq_read(struct sk_buff *skb,
420 unsigned int from, unsigned int to,
421 struct skb_seq_state *st);
422 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
423 struct skb_seq_state *st);
424 extern void skb_abort_seq_read(struct skb_seq_state *st);
426 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
427 unsigned int to, struct ts_config *config,
428 struct ts_state *state);
430 #ifdef NET_SKBUFF_DATA_USES_OFFSET
431 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
433 return skb->head + skb->end;
435 #else
436 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
438 return skb->end;
440 #endif
442 /* Internal */
443 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
446 * skb_queue_empty - check if a queue is empty
447 * @list: queue head
449 * Returns true if the queue is empty, false otherwise.
451 static inline int skb_queue_empty(const struct sk_buff_head *list)
453 return list->next == (struct sk_buff *)list;
457 * skb_get - reference buffer
458 * @skb: buffer to reference
460 * Makes another reference to a socket buffer and returns a pointer
461 * to the buffer.
463 static inline struct sk_buff *skb_get(struct sk_buff *skb)
465 atomic_inc(&skb->users);
466 return skb;
470 * If users == 1, we are the only owner and are can avoid redundant
471 * atomic change.
475 * skb_cloned - is the buffer a clone
476 * @skb: buffer to check
478 * Returns true if the buffer was generated with skb_clone() and is
479 * one of multiple shared copies of the buffer. Cloned buffers are
480 * shared data so must not be written to under normal circumstances.
482 static inline int skb_cloned(const struct sk_buff *skb)
484 return skb->cloned &&
485 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
489 * skb_header_cloned - is the header a clone
490 * @skb: buffer to check
492 * Returns true if modifying the header part of the buffer requires
493 * the data to be copied.
495 static inline int skb_header_cloned(const struct sk_buff *skb)
497 int dataref;
499 if (!skb->cloned)
500 return 0;
502 dataref = atomic_read(&skb_shinfo(skb)->dataref);
503 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
504 return dataref != 1;
508 * skb_header_release - release reference to header
509 * @skb: buffer to operate on
511 * Drop a reference to the header part of the buffer. This is done
512 * by acquiring a payload reference. You must not read from the header
513 * part of skb->data after this.
515 static inline void skb_header_release(struct sk_buff *skb)
517 BUG_ON(skb->nohdr);
518 skb->nohdr = 1;
519 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
523 * skb_shared - is the buffer shared
524 * @skb: buffer to check
526 * Returns true if more than one person has a reference to this
527 * buffer.
529 static inline int skb_shared(const struct sk_buff *skb)
531 return atomic_read(&skb->users) != 1;
535 * skb_share_check - check if buffer is shared and if so clone it
536 * @skb: buffer to check
537 * @pri: priority for memory allocation
539 * If the buffer is shared the buffer is cloned and the old copy
540 * drops a reference. A new clone with a single reference is returned.
541 * If the buffer is not shared the original buffer is returned. When
542 * being called from interrupt status or with spinlocks held pri must
543 * be GFP_ATOMIC.
545 * NULL is returned on a memory allocation failure.
547 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
548 gfp_t pri)
550 might_sleep_if(pri & __GFP_WAIT);
551 if (skb_shared(skb)) {
552 struct sk_buff *nskb = skb_clone(skb, pri);
553 kfree_skb(skb);
554 skb = nskb;
556 return skb;
560 * Copy shared buffers into a new sk_buff. We effectively do COW on
561 * packets to handle cases where we have a local reader and forward
562 * and a couple of other messy ones. The normal one is tcpdumping
563 * a packet thats being forwarded.
567 * skb_unshare - make a copy of a shared buffer
568 * @skb: buffer to check
569 * @pri: priority for memory allocation
571 * If the socket buffer is a clone then this function creates a new
572 * copy of the data, drops a reference count on the old copy and returns
573 * the new copy with the reference count at 1. If the buffer is not a clone
574 * the original buffer is returned. When called with a spinlock held or
575 * from interrupt state @pri must be %GFP_ATOMIC
577 * %NULL is returned on a memory allocation failure.
579 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
580 gfp_t pri)
582 might_sleep_if(pri & __GFP_WAIT);
583 if (skb_cloned(skb)) {
584 struct sk_buff *nskb = skb_copy(skb, pri);
585 kfree_skb(skb); /* Free our shared copy */
586 skb = nskb;
588 return skb;
592 * skb_peek
593 * @list_: list to peek at
595 * Peek an &sk_buff. Unlike most other operations you _MUST_
596 * be careful with this one. A peek leaves the buffer on the
597 * list and someone else may run off with it. You must hold
598 * the appropriate locks or have a private queue to do this.
600 * Returns %NULL for an empty list or a pointer to the head element.
601 * The reference count is not incremented and the reference is therefore
602 * volatile. Use with caution.
604 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
606 struct sk_buff *list = ((struct sk_buff *)list_)->next;
607 if (list == (struct sk_buff *)list_)
608 list = NULL;
609 return list;
613 * skb_peek_tail
614 * @list_: list to peek at
616 * Peek an &sk_buff. Unlike most other operations you _MUST_
617 * be careful with this one. A peek leaves the buffer on the
618 * list and someone else may run off with it. You must hold
619 * the appropriate locks or have a private queue to do this.
621 * Returns %NULL for an empty list or a pointer to the tail element.
622 * The reference count is not incremented and the reference is therefore
623 * volatile. Use with caution.
625 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
627 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
628 if (list == (struct sk_buff *)list_)
629 list = NULL;
630 return list;
634 * skb_queue_len - get queue length
635 * @list_: list to measure
637 * Return the length of an &sk_buff queue.
639 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
641 return list_->qlen;
645 * This function creates a split out lock class for each invocation;
646 * this is needed for now since a whole lot of users of the skb-queue
647 * infrastructure in drivers have different locking usage (in hardirq)
648 * than the networking core (in softirq only). In the long run either the
649 * network layer or drivers should need annotation to consolidate the
650 * main types of usage into 3 classes.
652 static inline void skb_queue_head_init(struct sk_buff_head *list)
654 spin_lock_init(&list->lock);
655 list->prev = list->next = (struct sk_buff *)list;
656 list->qlen = 0;
659 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
660 struct lock_class_key *class)
662 skb_queue_head_init(list);
663 lockdep_set_class(&list->lock, class);
667 * Insert an sk_buff on a list.
669 * The "__skb_xxxx()" functions are the non-atomic ones that
670 * can only be called with interrupts disabled.
672 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
673 static inline void __skb_insert(struct sk_buff *newsk,
674 struct sk_buff *prev, struct sk_buff *next,
675 struct sk_buff_head *list)
677 newsk->next = next;
678 newsk->prev = prev;
679 next->prev = prev->next = newsk;
680 list->qlen++;
684 * __skb_queue_after - queue a buffer at the list head
685 * @list: list to use
686 * @prev: place after this buffer
687 * @newsk: buffer to queue
689 * Queue a buffer int the middle of a list. This function takes no locks
690 * and you must therefore hold required locks before calling it.
692 * A buffer cannot be placed on two lists at the same time.
694 static inline void __skb_queue_after(struct sk_buff_head *list,
695 struct sk_buff *prev,
696 struct sk_buff *newsk)
698 __skb_insert(newsk, prev, prev->next, list);
701 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
702 struct sk_buff_head *list);
704 static inline void __skb_queue_before(struct sk_buff_head *list,
705 struct sk_buff *next,
706 struct sk_buff *newsk)
708 __skb_insert(newsk, next->prev, next, list);
712 * __skb_queue_head - queue a buffer at the list head
713 * @list: list to use
714 * @newsk: buffer to queue
716 * Queue a buffer at the start of a list. This function takes no locks
717 * and you must therefore hold required locks before calling it.
719 * A buffer cannot be placed on two lists at the same time.
721 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
722 static inline void __skb_queue_head(struct sk_buff_head *list,
723 struct sk_buff *newsk)
725 __skb_queue_after(list, (struct sk_buff *)list, newsk);
729 * __skb_queue_tail - queue a buffer at the list tail
730 * @list: list to use
731 * @newsk: buffer to queue
733 * Queue a buffer at the end of a list. This function takes no locks
734 * and you must therefore hold required locks before calling it.
736 * A buffer cannot be placed on two lists at the same time.
738 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
739 static inline void __skb_queue_tail(struct sk_buff_head *list,
740 struct sk_buff *newsk)
742 __skb_queue_before(list, (struct sk_buff *)list, newsk);
746 * remove sk_buff from list. _Must_ be called atomically, and with
747 * the list known..
749 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
750 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
752 struct sk_buff *next, *prev;
754 list->qlen--;
755 next = skb->next;
756 prev = skb->prev;
757 skb->next = skb->prev = NULL;
758 next->prev = prev;
759 prev->next = next;
763 * __skb_dequeue - remove from the head of the queue
764 * @list: list to dequeue from
766 * Remove the head of the list. This function does not take any locks
767 * so must be used with appropriate locks held only. The head item is
768 * returned or %NULL if the list is empty.
770 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
771 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
773 struct sk_buff *skb = skb_peek(list);
774 if (skb)
775 __skb_unlink(skb, list);
776 return skb;
780 * __skb_dequeue_tail - remove from the tail of the queue
781 * @list: list to dequeue from
783 * Remove the tail of the list. This function does not take any locks
784 * so must be used with appropriate locks held only. The tail item is
785 * returned or %NULL if the list is empty.
787 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
788 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
790 struct sk_buff *skb = skb_peek_tail(list);
791 if (skb)
792 __skb_unlink(skb, list);
793 return skb;
797 static inline int skb_is_nonlinear(const struct sk_buff *skb)
799 return skb->data_len;
802 static inline unsigned int skb_headlen(const struct sk_buff *skb)
804 return skb->len - skb->data_len;
807 static inline int skb_pagelen(const struct sk_buff *skb)
809 int i, len = 0;
811 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
812 len += skb_shinfo(skb)->frags[i].size;
813 return len + skb_headlen(skb);
816 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
817 struct page *page, int off, int size)
819 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
821 frag->page = page;
822 frag->page_offset = off;
823 frag->size = size;
824 skb_shinfo(skb)->nr_frags = i + 1;
827 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
828 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
829 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
831 #ifdef NET_SKBUFF_DATA_USES_OFFSET
832 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
834 return skb->head + skb->tail;
837 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
839 skb->tail = skb->data - skb->head;
842 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
844 skb_reset_tail_pointer(skb);
845 skb->tail += offset;
847 #else /* NET_SKBUFF_DATA_USES_OFFSET */
848 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
850 return skb->tail;
853 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
855 skb->tail = skb->data;
858 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
860 skb->tail = skb->data + offset;
863 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
866 * Add data to an sk_buff
868 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
869 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
871 unsigned char *tmp = skb_tail_pointer(skb);
872 SKB_LINEAR_ASSERT(skb);
873 skb->tail += len;
874 skb->len += len;
875 return tmp;
878 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
879 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
881 skb->data -= len;
882 skb->len += len;
883 return skb->data;
886 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
887 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
889 skb->len -= len;
890 BUG_ON(skb->len < skb->data_len);
891 return skb->data += len;
894 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
896 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
898 if (len > skb_headlen(skb) &&
899 !__pskb_pull_tail(skb, len-skb_headlen(skb)))
900 return NULL;
901 skb->len -= len;
902 return skb->data += len;
905 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
907 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
910 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
912 if (likely(len <= skb_headlen(skb)))
913 return 1;
914 if (unlikely(len > skb->len))
915 return 0;
916 return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL;
920 * skb_headroom - bytes at buffer head
921 * @skb: buffer to check
923 * Return the number of bytes of free space at the head of an &sk_buff.
925 static inline unsigned int skb_headroom(const struct sk_buff *skb)
927 return skb->data - skb->head;
931 * skb_tailroom - bytes at buffer end
932 * @skb: buffer to check
934 * Return the number of bytes of free space at the tail of an sk_buff
936 static inline int skb_tailroom(const struct sk_buff *skb)
938 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
942 * skb_reserve - adjust headroom
943 * @skb: buffer to alter
944 * @len: bytes to move
946 * Increase the headroom of an empty &sk_buff by reducing the tail
947 * room. This is only allowed for an empty buffer.
949 static inline void skb_reserve(struct sk_buff *skb, int len)
951 skb->data += len;
952 skb->tail += len;
955 #ifdef NET_SKBUFF_DATA_USES_OFFSET
956 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
958 return skb->head + skb->transport_header;
961 static inline void skb_reset_transport_header(struct sk_buff *skb)
963 skb->transport_header = skb->data - skb->head;
966 static inline void skb_set_transport_header(struct sk_buff *skb,
967 const int offset)
969 skb_reset_transport_header(skb);
970 skb->transport_header += offset;
973 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
975 return skb->head + skb->network_header;
978 static inline void skb_reset_network_header(struct sk_buff *skb)
980 skb->network_header = skb->data - skb->head;
983 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
985 skb_reset_network_header(skb);
986 skb->network_header += offset;
989 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
991 return skb->head + skb->mac_header;
994 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
996 return skb->mac_header != ~0U;
999 static inline void skb_reset_mac_header(struct sk_buff *skb)
1001 skb->mac_header = skb->data - skb->head;
1004 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1006 skb_reset_mac_header(skb);
1007 skb->mac_header += offset;
1010 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1012 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1014 return skb->transport_header;
1017 static inline void skb_reset_transport_header(struct sk_buff *skb)
1019 skb->transport_header = skb->data;
1022 static inline void skb_set_transport_header(struct sk_buff *skb,
1023 const int offset)
1025 skb->transport_header = skb->data + offset;
1028 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1030 return skb->network_header;
1033 static inline void skb_reset_network_header(struct sk_buff *skb)
1035 skb->network_header = skb->data;
1038 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1040 skb->network_header = skb->data + offset;
1043 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1045 return skb->mac_header;
1048 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1050 return skb->mac_header != NULL;
1053 static inline void skb_reset_mac_header(struct sk_buff *skb)
1055 skb->mac_header = skb->data;
1058 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1060 skb->mac_header = skb->data + offset;
1062 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1064 static inline int skb_transport_offset(const struct sk_buff *skb)
1066 return skb_transport_header(skb) - skb->data;
1069 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1071 return skb->transport_header - skb->network_header;
1074 static inline int skb_network_offset(const struct sk_buff *skb)
1076 return skb_network_header(skb) - skb->data;
1080 * CPUs often take a performance hit when accessing unaligned memory
1081 * locations. The actual performance hit varies, it can be small if the
1082 * hardware handles it or large if we have to take an exception and fix it
1083 * in software.
1085 * Since an ethernet header is 14 bytes network drivers often end up with
1086 * the IP header at an unaligned offset. The IP header can be aligned by
1087 * shifting the start of the packet by 2 bytes. Drivers should do this
1088 * with:
1090 * skb_reserve(NET_IP_ALIGN);
1092 * The downside to this alignment of the IP header is that the DMA is now
1093 * unaligned. On some architectures the cost of an unaligned DMA is high
1094 * and this cost outweighs the gains made by aligning the IP header.
1096 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1097 * to be overridden.
1099 #ifndef NET_IP_ALIGN
1100 #define NET_IP_ALIGN 2
1101 #endif
1104 * The networking layer reserves some headroom in skb data (via
1105 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1106 * the header has to grow. In the default case, if the header has to grow
1107 * 16 bytes or less we avoid the reallocation.
1109 * Unfortunately this headroom changes the DMA alignment of the resulting
1110 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1111 * on some architectures. An architecture can override this value,
1112 * perhaps setting it to a cacheline in size (since that will maintain
1113 * cacheline alignment of the DMA). It must be a power of 2.
1115 * Various parts of the networking layer expect at least 16 bytes of
1116 * headroom, you should not reduce this.
1118 #ifndef NET_SKB_PAD
1119 #define NET_SKB_PAD 16
1120 #endif
1122 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1124 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1126 if (unlikely(skb->data_len)) {
1127 WARN_ON(1);
1128 return;
1130 skb->len = len;
1131 skb_set_tail_pointer(skb, len);
1134 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1136 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1138 if (skb->data_len)
1139 return ___pskb_trim(skb, len);
1140 __skb_trim(skb, len);
1141 return 0;
1144 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1146 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1150 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1151 * @skb: buffer to alter
1152 * @len: new length
1154 * This is identical to pskb_trim except that the caller knows that
1155 * the skb is not cloned so we should never get an error due to out-
1156 * of-memory.
1158 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1160 int err = pskb_trim(skb, len);
1161 BUG_ON(err);
1165 * skb_orphan - orphan a buffer
1166 * @skb: buffer to orphan
1168 * If a buffer currently has an owner then we call the owner's
1169 * destructor function and make the @skb unowned. The buffer continues
1170 * to exist but is no longer charged to its former owner.
1172 static inline void skb_orphan(struct sk_buff *skb)
1174 if (skb->destructor)
1175 skb->destructor(skb);
1176 skb->destructor = NULL;
1177 skb->sk = NULL;
1181 * __skb_queue_purge - empty a list
1182 * @list: list to empty
1184 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1185 * the list and one reference dropped. This function does not take the
1186 * list lock and the caller must hold the relevant locks to use it.
1188 extern void skb_queue_purge(struct sk_buff_head *list);
1189 static inline void __skb_queue_purge(struct sk_buff_head *list)
1191 struct sk_buff *skb;
1192 while ((skb = __skb_dequeue(list)) != NULL)
1193 kfree_skb(skb);
1197 * __dev_alloc_skb - allocate an skbuff for receiving
1198 * @length: length to allocate
1199 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1201 * Allocate a new &sk_buff and assign it a usage count of one. The
1202 * buffer has unspecified headroom built in. Users should allocate
1203 * the headroom they think they need without accounting for the
1204 * built in space. The built in space is used for optimisations.
1206 * %NULL is returned if there is no free memory.
1208 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1209 gfp_t gfp_mask)
1211 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1212 if (likely(skb))
1213 skb_reserve(skb, NET_SKB_PAD);
1214 return skb;
1217 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1219 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1220 unsigned int length, gfp_t gfp_mask);
1223 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1224 * @dev: network device to receive on
1225 * @length: length to allocate
1227 * Allocate a new &sk_buff and assign it a usage count of one. The
1228 * buffer has unspecified headroom built in. Users should allocate
1229 * the headroom they think they need without accounting for the
1230 * built in space. The built in space is used for optimisations.
1232 * %NULL is returned if there is no free memory. Although this function
1233 * allocates memory it can be called from an interrupt.
1235 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1236 unsigned int length)
1238 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1242 * skb_clone_writable - is the header of a clone writable
1243 * @skb: buffer to check
1244 * @len: length up to which to write
1246 * Returns true if modifying the header part of the cloned buffer
1247 * does not requires the data to be copied.
1249 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1251 return !skb_header_cloned(skb) &&
1252 skb_headroom(skb) + len <= skb->hdr_len;
1255 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1256 int cloned)
1258 int delta = 0;
1260 if (headroom < NET_SKB_PAD)
1261 headroom = NET_SKB_PAD;
1262 if (headroom > skb_headroom(skb))
1263 delta = headroom - skb_headroom(skb);
1265 if (delta || cloned)
1266 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1267 GFP_ATOMIC);
1268 return 0;
1272 * skb_cow - copy header of skb when it is required
1273 * @skb: buffer to cow
1274 * @headroom: needed headroom
1276 * If the skb passed lacks sufficient headroom or its data part
1277 * is shared, data is reallocated. If reallocation fails, an error
1278 * is returned and original skb is not changed.
1280 * The result is skb with writable area skb->head...skb->tail
1281 * and at least @headroom of space at head.
1283 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1285 return __skb_cow(skb, headroom, skb_cloned(skb));
1289 * skb_cow_head - skb_cow but only making the head writable
1290 * @skb: buffer to cow
1291 * @headroom: needed headroom
1293 * This function is identical to skb_cow except that we replace the
1294 * skb_cloned check by skb_header_cloned. It should be used when
1295 * you only need to push on some header and do not need to modify
1296 * the data.
1298 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1300 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1304 * skb_padto - pad an skbuff up to a minimal size
1305 * @skb: buffer to pad
1306 * @len: minimal length
1308 * Pads up a buffer to ensure the trailing bytes exist and are
1309 * blanked. If the buffer already contains sufficient data it
1310 * is untouched. Otherwise it is extended. Returns zero on
1311 * success. The skb is freed on error.
1314 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1316 unsigned int size = skb->len;
1317 if (likely(size >= len))
1318 return 0;
1319 return skb_pad(skb, len-size);
1322 static inline int skb_add_data(struct sk_buff *skb,
1323 char __user *from, int copy)
1325 const int off = skb->len;
1327 if (skb->ip_summed == CHECKSUM_NONE) {
1328 int err = 0;
1329 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1330 copy, 0, &err);
1331 if (!err) {
1332 skb->csum = csum_block_add(skb->csum, csum, off);
1333 return 0;
1335 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1336 return 0;
1338 __skb_trim(skb, off);
1339 return -EFAULT;
1342 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1343 struct page *page, int off)
1345 if (i) {
1346 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1348 return page == frag->page &&
1349 off == frag->page_offset + frag->size;
1351 return 0;
1354 static inline int __skb_linearize(struct sk_buff *skb)
1356 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1360 * skb_linearize - convert paged skb to linear one
1361 * @skb: buffer to linarize
1363 * If there is no free memory -ENOMEM is returned, otherwise zero
1364 * is returned and the old skb data released.
1366 static inline int skb_linearize(struct sk_buff *skb)
1368 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1372 * skb_linearize_cow - make sure skb is linear and writable
1373 * @skb: buffer to process
1375 * If there is no free memory -ENOMEM is returned, otherwise zero
1376 * is returned and the old skb data released.
1378 static inline int skb_linearize_cow(struct sk_buff *skb)
1380 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1381 __skb_linearize(skb) : 0;
1385 * skb_postpull_rcsum - update checksum for received skb after pull
1386 * @skb: buffer to update
1387 * @start: start of data before pull
1388 * @len: length of data pulled
1390 * After doing a pull on a received packet, you need to call this to
1391 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1392 * CHECKSUM_NONE so that it can be recomputed from scratch.
1395 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1396 const void *start, unsigned int len)
1398 if (skb->ip_summed == CHECKSUM_COMPLETE)
1399 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1402 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1405 * pskb_trim_rcsum - trim received skb and update checksum
1406 * @skb: buffer to trim
1407 * @len: new length
1409 * This is exactly the same as pskb_trim except that it ensures the
1410 * checksum of received packets are still valid after the operation.
1413 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1415 if (likely(len >= skb->len))
1416 return 0;
1417 if (skb->ip_summed == CHECKSUM_COMPLETE)
1418 skb->ip_summed = CHECKSUM_NONE;
1419 return __pskb_trim(skb, len);
1422 #define skb_queue_walk(queue, skb) \
1423 for (skb = (queue)->next; \
1424 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1425 skb = skb->next)
1427 #define skb_queue_walk_safe(queue, skb, tmp) \
1428 for (skb = (queue)->next, tmp = skb->next; \
1429 skb != (struct sk_buff *)(queue); \
1430 skb = tmp, tmp = skb->next)
1432 #define skb_queue_reverse_walk(queue, skb) \
1433 for (skb = (queue)->prev; \
1434 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1435 skb = skb->prev)
1438 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1439 int *peeked, int *err);
1440 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1441 int noblock, int *err);
1442 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1443 struct poll_table_struct *wait);
1444 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1445 int offset, struct iovec *to,
1446 int size);
1447 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1448 int hlen,
1449 struct iovec *iov);
1450 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1451 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1452 unsigned int flags);
1453 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1454 int len, __wsum csum);
1455 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1456 void *to, int len);
1457 extern int skb_store_bits(struct sk_buff *skb, int offset,
1458 const void *from, int len);
1459 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1460 int offset, u8 *to, int len,
1461 __wsum csum);
1462 extern int skb_splice_bits(struct sk_buff *skb,
1463 unsigned int offset,
1464 struct pipe_inode_info *pipe,
1465 unsigned int len,
1466 unsigned int flags);
1467 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1468 extern void skb_split(struct sk_buff *skb,
1469 struct sk_buff *skb1, const u32 len);
1471 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1473 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1474 int len, void *buffer)
1476 int hlen = skb_headlen(skb);
1478 if (hlen - offset >= len)
1479 return skb->data + offset;
1481 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1482 return NULL;
1484 return buffer;
1487 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1488 void *to,
1489 const unsigned int len)
1491 memcpy(to, skb->data, len);
1494 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1495 const int offset, void *to,
1496 const unsigned int len)
1498 memcpy(to, skb->data + offset, len);
1501 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1502 const void *from,
1503 const unsigned int len)
1505 memcpy(skb->data, from, len);
1508 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1509 const int offset,
1510 const void *from,
1511 const unsigned int len)
1513 memcpy(skb->data + offset, from, len);
1516 extern void skb_init(void);
1519 * skb_get_timestamp - get timestamp from a skb
1520 * @skb: skb to get stamp from
1521 * @stamp: pointer to struct timeval to store stamp in
1523 * Timestamps are stored in the skb as offsets to a base timestamp.
1524 * This function converts the offset back to a struct timeval and stores
1525 * it in stamp.
1527 static inline void skb_get_timestamp(const struct sk_buff *skb, struct timeval *stamp)
1529 *stamp = ktime_to_timeval(skb->tstamp);
1532 static inline void __net_timestamp(struct sk_buff *skb)
1534 skb->tstamp = ktime_get_real();
1537 static inline ktime_t net_timedelta(ktime_t t)
1539 return ktime_sub(ktime_get_real(), t);
1542 static inline ktime_t net_invalid_timestamp(void)
1544 return ktime_set(0, 0);
1547 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1548 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1550 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1552 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1556 * skb_checksum_complete - Calculate checksum of an entire packet
1557 * @skb: packet to process
1559 * This function calculates the checksum over the entire packet plus
1560 * the value of skb->csum. The latter can be used to supply the
1561 * checksum of a pseudo header as used by TCP/UDP. It returns the
1562 * checksum.
1564 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1565 * this function can be used to verify that checksum on received
1566 * packets. In that case the function should return zero if the
1567 * checksum is correct. In particular, this function will return zero
1568 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1569 * hardware has already verified the correctness of the checksum.
1571 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1573 return skb_csum_unnecessary(skb) ?
1574 0 : __skb_checksum_complete(skb);
1577 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1578 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1579 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1581 if (nfct && atomic_dec_and_test(&nfct->use))
1582 nf_conntrack_destroy(nfct);
1584 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1586 if (nfct)
1587 atomic_inc(&nfct->use);
1589 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1591 if (skb)
1592 atomic_inc(&skb->users);
1594 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1596 if (skb)
1597 kfree_skb(skb);
1599 #endif
1600 #ifdef CONFIG_BRIDGE_NETFILTER
1601 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1603 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1604 kfree(nf_bridge);
1606 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1608 if (nf_bridge)
1609 atomic_inc(&nf_bridge->use);
1611 #endif /* CONFIG_BRIDGE_NETFILTER */
1612 static inline void nf_reset(struct sk_buff *skb)
1614 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1615 nf_conntrack_put(skb->nfct);
1616 skb->nfct = NULL;
1617 nf_conntrack_put_reasm(skb->nfct_reasm);
1618 skb->nfct_reasm = NULL;
1619 #endif
1620 #ifdef CONFIG_BRIDGE_NETFILTER
1621 nf_bridge_put(skb->nf_bridge);
1622 skb->nf_bridge = NULL;
1623 #endif
1626 /* Note: This doesn't put any conntrack and bridge info in dst. */
1627 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1629 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1630 dst->nfct = src->nfct;
1631 nf_conntrack_get(src->nfct);
1632 dst->nfctinfo = src->nfctinfo;
1633 dst->nfct_reasm = src->nfct_reasm;
1634 nf_conntrack_get_reasm(src->nfct_reasm);
1635 #endif
1636 #ifdef CONFIG_BRIDGE_NETFILTER
1637 dst->nf_bridge = src->nf_bridge;
1638 nf_bridge_get(src->nf_bridge);
1639 #endif
1642 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1644 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1645 nf_conntrack_put(dst->nfct);
1646 nf_conntrack_put_reasm(dst->nfct_reasm);
1647 #endif
1648 #ifdef CONFIG_BRIDGE_NETFILTER
1649 nf_bridge_put(dst->nf_bridge);
1650 #endif
1651 __nf_copy(dst, src);
1654 #ifdef CONFIG_NETWORK_SECMARK
1655 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1657 to->secmark = from->secmark;
1660 static inline void skb_init_secmark(struct sk_buff *skb)
1662 skb->secmark = 0;
1664 #else
1665 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1668 static inline void skb_init_secmark(struct sk_buff *skb)
1670 #endif
1672 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1674 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1675 skb->queue_mapping = queue_mapping;
1676 #endif
1679 static inline u16 skb_get_queue_mapping(struct sk_buff *skb)
1681 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1682 return skb->queue_mapping;
1683 #else
1684 return 0;
1685 #endif
1688 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1690 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1691 to->queue_mapping = from->queue_mapping;
1692 #endif
1695 static inline int skb_is_gso(const struct sk_buff *skb)
1697 return skb_shinfo(skb)->gso_size;
1700 static inline int skb_is_gso_v6(const struct sk_buff *skb)
1702 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
1705 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
1707 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
1709 /* LRO sets gso_size but not gso_type, whereas if GSO is really
1710 * wanted then gso_type will be set. */
1711 struct skb_shared_info *shinfo = skb_shinfo(skb);
1712 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
1713 __skb_warn_lro_forwarding(skb);
1714 return true;
1716 return false;
1719 static inline void skb_forward_csum(struct sk_buff *skb)
1721 /* Unfortunately we don't support this one. Any brave souls? */
1722 if (skb->ip_summed == CHECKSUM_COMPLETE)
1723 skb->ip_summed = CHECKSUM_NONE;
1726 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
1727 #endif /* __KERNEL__ */
1728 #endif /* _LINUX_SKBUFF_H */