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 #ifdef CONFIG_HAS_DMA
150 unsigned int num_dma_maps;
152 struct sk_buff *frag_list;
153 skb_frag_t frags[MAX_SKB_FRAGS];
154 #ifdef CONFIG_HAS_DMA
155 dma_addr_t dma_maps[MAX_SKB_FRAGS + 1];
159 /* We divide dataref into two halves. The higher 16 bits hold references
160 * to the payload part of skb->data. The lower 16 bits hold references to
161 * the entire skb->data. A clone of a headerless skb holds the length of
162 * the header in skb->hdr_len.
164 * All users must obey the rule that the skb->data reference count must be
165 * greater than or equal to the payload reference count.
167 * Holding a reference to the payload part means that the user does not
168 * care about modifications to the header part of skb->data.
170 #define SKB_DATAREF_SHIFT 16
171 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
175 SKB_FCLONE_UNAVAILABLE,
181 SKB_GSO_TCPV4 = 1 << 0,
182 SKB_GSO_UDP = 1 << 1,
184 /* This indicates the skb is from an untrusted source. */
185 SKB_GSO_DODGY = 1 << 2,
187 /* This indicates the tcp segment has CWR set. */
188 SKB_GSO_TCP_ECN = 1 << 3,
190 SKB_GSO_TCPV6 = 1 << 4,
193 #if BITS_PER_LONG > 32
194 #define NET_SKBUFF_DATA_USES_OFFSET 1
197 #ifdef NET_SKBUFF_DATA_USES_OFFSET
198 typedef unsigned int sk_buff_data_t;
200 typedef unsigned char *sk_buff_data_t;
204 * struct sk_buff - socket buffer
205 * @next: Next buffer in list
206 * @prev: Previous buffer in list
207 * @sk: Socket we are owned by
208 * @tstamp: Time we arrived
209 * @dev: Device we arrived on/are leaving by
210 * @transport_header: Transport layer header
211 * @network_header: Network layer header
212 * @mac_header: Link layer header
213 * @dst: destination entry
214 * @sp: the security path, used for xfrm
215 * @cb: Control buffer. Free for use by every layer. Put private vars here
216 * @len: Length of actual data
217 * @data_len: Data length
218 * @mac_len: Length of link layer header
219 * @hdr_len: writable header length of cloned skb
220 * @csum: Checksum (must include start/offset pair)
221 * @csum_start: Offset from skb->head where checksumming should start
222 * @csum_offset: Offset from csum_start where checksum should be stored
223 * @local_df: allow local fragmentation
224 * @cloned: Head may be cloned (check refcnt to be sure)
225 * @nohdr: Payload reference only, must not modify header
226 * @pkt_type: Packet class
227 * @fclone: skbuff clone status
228 * @ip_summed: Driver fed us an IP checksum
229 * @priority: Packet queueing priority
230 * @users: User count - see {datagram,tcp}.c
231 * @protocol: Packet protocol from driver
232 * @truesize: Buffer size
233 * @head: Head of buffer
234 * @data: Data head pointer
235 * @tail: Tail pointer
237 * @destructor: Destruct function
238 * @mark: Generic packet mark
239 * @nfct: Associated connection, if any
240 * @ipvs_property: skbuff is owned by ipvs
241 * @peeked: this packet has been seen already, so stats have been
242 * done for it, don't do them again
243 * @nf_trace: netfilter packet trace flag
244 * @nfctinfo: Relationship of this skb to the connection
245 * @nfct_reasm: netfilter conntrack re-assembly pointer
246 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
247 * @iif: ifindex of device we arrived on
248 * @queue_mapping: Queue mapping for multiqueue devices
249 * @tc_index: Traffic control index
250 * @tc_verd: traffic control verdict
251 * @ndisc_nodetype: router type (from link layer)
252 * @do_not_encrypt: set to prevent encryption of this frame
253 * @dma_cookie: a cookie to one of several possible DMA operations
254 * done by skb DMA functions
255 * @secmark: security marking
256 * @vlan_tci: vlan tag control information
260 /* These two members must be first. */
261 struct sk_buff *next;
262 struct sk_buff *prev;
266 struct net_device *dev;
269 struct dst_entry *dst;
270 struct rtable *rtable;
275 * This is the control buffer. It is free to use for every
276 * layer. Please put your private variables there. If you
277 * want to keep them across layers you have to do a skb_clone()
278 * first. This is owned by whoever has the skb queued ATM.
306 void (*destructor)(struct sk_buff *skb);
307 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
308 struct nf_conntrack *nfct;
309 struct sk_buff *nfct_reasm;
311 #ifdef CONFIG_BRIDGE_NETFILTER
312 struct nf_bridge_info *nf_bridge;
317 #ifdef CONFIG_NET_SCHED
318 __u16 tc_index; /* traffic control index */
319 #ifdef CONFIG_NET_CLS_ACT
320 __u16 tc_verd; /* traffic control verdict */
323 #ifdef CONFIG_IPV6_NDISC_NODETYPE
324 __u8 ndisc_nodetype:2;
326 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
327 __u8 do_not_encrypt:1;
329 /* 0/13/14 bit hole */
331 #ifdef CONFIG_NET_DMA
332 dma_cookie_t dma_cookie;
334 #ifdef CONFIG_NETWORK_SECMARK
342 sk_buff_data_t transport_header;
343 sk_buff_data_t network_header;
344 sk_buff_data_t mac_header;
345 /* These elements must be at the end, see alloc_skb() for details. */
350 unsigned int truesize;
356 * Handling routines are only of interest to the kernel
358 #include <linux/slab.h>
360 #include <asm/system.h>
362 #ifdef CONFIG_HAS_DMA
363 #include <linux/dma-mapping.h>
364 extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
365 enum dma_data_direction dir);
366 extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
367 enum dma_data_direction dir);
370 extern void kfree_skb(struct sk_buff *skb);
371 extern void __kfree_skb(struct sk_buff *skb);
372 extern struct sk_buff *__alloc_skb(unsigned int size,
373 gfp_t priority, int fclone, int node);
374 static inline struct sk_buff *alloc_skb(unsigned int size,
377 return __alloc_skb(size, priority, 0, -1);
380 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
383 return __alloc_skb(size, priority, 1, -1);
386 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
387 extern struct sk_buff *skb_clone(struct sk_buff *skb,
389 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
391 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
393 extern int pskb_expand_head(struct sk_buff *skb,
394 int nhead, int ntail,
396 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
397 unsigned int headroom);
398 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
399 int newheadroom, int newtailroom,
401 extern int skb_to_sgvec(struct sk_buff *skb,
402 struct scatterlist *sg, int offset,
404 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
405 struct sk_buff **trailer);
406 extern int skb_pad(struct sk_buff *skb, int pad);
407 #define dev_kfree_skb(a) kfree_skb(a)
408 extern void skb_over_panic(struct sk_buff *skb, int len,
410 extern void skb_under_panic(struct sk_buff *skb, int len,
412 extern void skb_truesize_bug(struct sk_buff *skb);
414 static inline void skb_truesize_check(struct sk_buff *skb)
416 int len = sizeof(struct sk_buff) + skb->len;
418 if (unlikely((int)skb->truesize < len))
419 skb_truesize_bug(skb);
422 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
423 int getfrag(void *from, char *to, int offset,
424 int len,int odd, struct sk_buff *skb),
425 void *from, int length);
432 __u32 stepped_offset;
433 struct sk_buff *root_skb;
434 struct sk_buff *cur_skb;
438 extern void skb_prepare_seq_read(struct sk_buff *skb,
439 unsigned int from, unsigned int to,
440 struct skb_seq_state *st);
441 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
442 struct skb_seq_state *st);
443 extern void skb_abort_seq_read(struct skb_seq_state *st);
445 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
446 unsigned int to, struct ts_config *config,
447 struct ts_state *state);
449 #ifdef NET_SKBUFF_DATA_USES_OFFSET
450 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
452 return skb->head + skb->end;
455 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
462 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
465 * skb_queue_empty - check if a queue is empty
468 * Returns true if the queue is empty, false otherwise.
470 static inline int skb_queue_empty(const struct sk_buff_head *list)
472 return list->next == (struct sk_buff *)list;
476 * skb_queue_is_last - check if skb is the last entry in the queue
480 * Returns true if @skb is the last buffer on the list.
482 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
483 const struct sk_buff *skb)
485 return (skb->next == (struct sk_buff *) list);
489 * skb_queue_next - return the next packet in the queue
491 * @skb: current buffer
493 * Return the next packet in @list after @skb. It is only valid to
494 * call this if skb_queue_is_last() evaluates to false.
496 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
497 const struct sk_buff *skb)
499 /* This BUG_ON may seem severe, but if we just return then we
500 * are going to dereference garbage.
502 BUG_ON(skb_queue_is_last(list, skb));
507 * skb_get - reference buffer
508 * @skb: buffer to reference
510 * Makes another reference to a socket buffer and returns a pointer
513 static inline struct sk_buff *skb_get(struct sk_buff *skb)
515 atomic_inc(&skb->users);
520 * If users == 1, we are the only owner and are can avoid redundant
525 * skb_cloned - is the buffer a clone
526 * @skb: buffer to check
528 * Returns true if the buffer was generated with skb_clone() and is
529 * one of multiple shared copies of the buffer. Cloned buffers are
530 * shared data so must not be written to under normal circumstances.
532 static inline int skb_cloned(const struct sk_buff *skb)
534 return skb->cloned &&
535 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
539 * skb_header_cloned - is the header a clone
540 * @skb: buffer to check
542 * Returns true if modifying the header part of the buffer requires
543 * the data to be copied.
545 static inline int skb_header_cloned(const struct sk_buff *skb)
552 dataref = atomic_read(&skb_shinfo(skb)->dataref);
553 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
558 * skb_header_release - release reference to header
559 * @skb: buffer to operate on
561 * Drop a reference to the header part of the buffer. This is done
562 * by acquiring a payload reference. You must not read from the header
563 * part of skb->data after this.
565 static inline void skb_header_release(struct sk_buff *skb)
569 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
573 * skb_shared - is the buffer shared
574 * @skb: buffer to check
576 * Returns true if more than one person has a reference to this
579 static inline int skb_shared(const struct sk_buff *skb)
581 return atomic_read(&skb->users) != 1;
585 * skb_share_check - check if buffer is shared and if so clone it
586 * @skb: buffer to check
587 * @pri: priority for memory allocation
589 * If the buffer is shared the buffer is cloned and the old copy
590 * drops a reference. A new clone with a single reference is returned.
591 * If the buffer is not shared the original buffer is returned. When
592 * being called from interrupt status or with spinlocks held pri must
595 * NULL is returned on a memory allocation failure.
597 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
600 might_sleep_if(pri & __GFP_WAIT);
601 if (skb_shared(skb)) {
602 struct sk_buff *nskb = skb_clone(skb, pri);
610 * Copy shared buffers into a new sk_buff. We effectively do COW on
611 * packets to handle cases where we have a local reader and forward
612 * and a couple of other messy ones. The normal one is tcpdumping
613 * a packet thats being forwarded.
617 * skb_unshare - make a copy of a shared buffer
618 * @skb: buffer to check
619 * @pri: priority for memory allocation
621 * If the socket buffer is a clone then this function creates a new
622 * copy of the data, drops a reference count on the old copy and returns
623 * the new copy with the reference count at 1. If the buffer is not a clone
624 * the original buffer is returned. When called with a spinlock held or
625 * from interrupt state @pri must be %GFP_ATOMIC
627 * %NULL is returned on a memory allocation failure.
629 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
632 might_sleep_if(pri & __GFP_WAIT);
633 if (skb_cloned(skb)) {
634 struct sk_buff *nskb = skb_copy(skb, pri);
635 kfree_skb(skb); /* Free our shared copy */
643 * @list_: list to peek at
645 * Peek an &sk_buff. Unlike most other operations you _MUST_
646 * be careful with this one. A peek leaves the buffer on the
647 * list and someone else may run off with it. You must hold
648 * the appropriate locks or have a private queue to do this.
650 * Returns %NULL for an empty list or a pointer to the head element.
651 * The reference count is not incremented and the reference is therefore
652 * volatile. Use with caution.
654 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
656 struct sk_buff *list = ((struct sk_buff *)list_)->next;
657 if (list == (struct sk_buff *)list_)
664 * @list_: list to peek at
666 * Peek an &sk_buff. Unlike most other operations you _MUST_
667 * be careful with this one. A peek leaves the buffer on the
668 * list and someone else may run off with it. You must hold
669 * the appropriate locks or have a private queue to do this.
671 * Returns %NULL for an empty list or a pointer to the tail element.
672 * The reference count is not incremented and the reference is therefore
673 * volatile. Use with caution.
675 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
677 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
678 if (list == (struct sk_buff *)list_)
684 * skb_queue_len - get queue length
685 * @list_: list to measure
687 * Return the length of an &sk_buff queue.
689 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
695 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
696 * @list: queue to initialize
698 * This initializes only the list and queue length aspects of
699 * an sk_buff_head object. This allows to initialize the list
700 * aspects of an sk_buff_head without reinitializing things like
701 * the spinlock. It can also be used for on-stack sk_buff_head
702 * objects where the spinlock is known to not be used.
704 static inline void __skb_queue_head_init(struct sk_buff_head *list)
706 list->prev = list->next = (struct sk_buff *)list;
711 * This function creates a split out lock class for each invocation;
712 * this is needed for now since a whole lot of users of the skb-queue
713 * infrastructure in drivers have different locking usage (in hardirq)
714 * than the networking core (in softirq only). In the long run either the
715 * network layer or drivers should need annotation to consolidate the
716 * main types of usage into 3 classes.
718 static inline void skb_queue_head_init(struct sk_buff_head *list)
720 spin_lock_init(&list->lock);
721 __skb_queue_head_init(list);
724 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
725 struct lock_class_key *class)
727 skb_queue_head_init(list);
728 lockdep_set_class(&list->lock, class);
732 * Insert an sk_buff on a list.
734 * The "__skb_xxxx()" functions are the non-atomic ones that
735 * can only be called with interrupts disabled.
737 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
738 static inline void __skb_insert(struct sk_buff *newsk,
739 struct sk_buff *prev, struct sk_buff *next,
740 struct sk_buff_head *list)
744 next->prev = prev->next = newsk;
748 static inline void __skb_queue_splice(const struct sk_buff_head *list,
749 struct sk_buff *prev,
750 struct sk_buff *next)
752 struct sk_buff *first = list->next;
753 struct sk_buff *last = list->prev;
763 * skb_queue_splice - join two skb lists, this is designed for stacks
764 * @list: the new list to add
765 * @head: the place to add it in the first list
767 static inline void skb_queue_splice(const struct sk_buff_head *list,
768 struct sk_buff_head *head)
770 if (!skb_queue_empty(list)) {
771 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
772 head->qlen += list->qlen;
777 * skb_queue_splice - join two skb lists and reinitialise the emptied list
778 * @list: the new list to add
779 * @head: the place to add it in the first list
781 * The list at @list is reinitialised
783 static inline void skb_queue_splice_init(struct sk_buff_head *list,
784 struct sk_buff_head *head)
786 if (!skb_queue_empty(list)) {
787 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
788 head->qlen += list->qlen;
789 __skb_queue_head_init(list);
794 * skb_queue_splice_tail - join two skb lists, each list being a queue
795 * @list: the new list to add
796 * @head: the place to add it in the first list
798 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
799 struct sk_buff_head *head)
801 if (!skb_queue_empty(list)) {
802 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
803 head->qlen += list->qlen;
808 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
809 * @list: the new list to add
810 * @head: the place to add it in the first list
812 * Each of the lists is a queue.
813 * The list at @list is reinitialised
815 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
816 struct sk_buff_head *head)
818 if (!skb_queue_empty(list)) {
819 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
820 head->qlen += list->qlen;
821 __skb_queue_head_init(list);
826 * __skb_queue_after - queue a buffer at the list head
828 * @prev: place after this buffer
829 * @newsk: buffer to queue
831 * Queue a buffer int the middle of a list. This function takes no locks
832 * and you must therefore hold required locks before calling it.
834 * A buffer cannot be placed on two lists at the same time.
836 static inline void __skb_queue_after(struct sk_buff_head *list,
837 struct sk_buff *prev,
838 struct sk_buff *newsk)
840 __skb_insert(newsk, prev, prev->next, list);
843 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
844 struct sk_buff_head *list);
846 static inline void __skb_queue_before(struct sk_buff_head *list,
847 struct sk_buff *next,
848 struct sk_buff *newsk)
850 __skb_insert(newsk, next->prev, next, list);
854 * __skb_queue_head - queue a buffer at the list head
856 * @newsk: buffer to queue
858 * Queue a buffer at the start of a list. This function takes no locks
859 * and you must therefore hold required locks before calling it.
861 * A buffer cannot be placed on two lists at the same time.
863 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
864 static inline void __skb_queue_head(struct sk_buff_head *list,
865 struct sk_buff *newsk)
867 __skb_queue_after(list, (struct sk_buff *)list, newsk);
871 * __skb_queue_tail - queue a buffer at the list tail
873 * @newsk: buffer to queue
875 * Queue a buffer at the end of a list. This function takes no locks
876 * and you must therefore hold required locks before calling it.
878 * A buffer cannot be placed on two lists at the same time.
880 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
881 static inline void __skb_queue_tail(struct sk_buff_head *list,
882 struct sk_buff *newsk)
884 __skb_queue_before(list, (struct sk_buff *)list, newsk);
888 * remove sk_buff from list. _Must_ be called atomically, and with
891 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
892 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
894 struct sk_buff *next, *prev;
899 skb->next = skb->prev = NULL;
905 * __skb_dequeue - remove from the head of the queue
906 * @list: list to dequeue from
908 * Remove the head of the list. This function does not take any locks
909 * so must be used with appropriate locks held only. The head item is
910 * returned or %NULL if the list is empty.
912 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
913 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
915 struct sk_buff *skb = skb_peek(list);
917 __skb_unlink(skb, list);
922 * __skb_dequeue_tail - remove from the tail of the queue
923 * @list: list to dequeue from
925 * Remove the tail of the list. This function does not take any locks
926 * so must be used with appropriate locks held only. The tail item is
927 * returned or %NULL if the list is empty.
929 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
930 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
932 struct sk_buff *skb = skb_peek_tail(list);
934 __skb_unlink(skb, list);
939 static inline int skb_is_nonlinear(const struct sk_buff *skb)
941 return skb->data_len;
944 static inline unsigned int skb_headlen(const struct sk_buff *skb)
946 return skb->len - skb->data_len;
949 static inline int skb_pagelen(const struct sk_buff *skb)
953 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
954 len += skb_shinfo(skb)->frags[i].size;
955 return len + skb_headlen(skb);
958 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
959 struct page *page, int off, int size)
961 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
964 frag->page_offset = off;
966 skb_shinfo(skb)->nr_frags = i + 1;
969 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
970 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
971 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
973 #ifdef NET_SKBUFF_DATA_USES_OFFSET
974 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
976 return skb->head + skb->tail;
979 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
981 skb->tail = skb->data - skb->head;
984 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
986 skb_reset_tail_pointer(skb);
989 #else /* NET_SKBUFF_DATA_USES_OFFSET */
990 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
995 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
997 skb->tail = skb->data;
1000 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1002 skb->tail = skb->data + offset;
1005 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1008 * Add data to an sk_buff
1010 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1011 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1013 unsigned char *tmp = skb_tail_pointer(skb);
1014 SKB_LINEAR_ASSERT(skb);
1020 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1021 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1028 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1029 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1032 BUG_ON(skb->len < skb->data_len);
1033 return skb->data += len;
1036 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1038 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1040 if (len > skb_headlen(skb) &&
1041 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1044 return skb->data += len;
1047 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1049 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1052 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1054 if (likely(len <= skb_headlen(skb)))
1056 if (unlikely(len > skb->len))
1058 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1062 * skb_headroom - bytes at buffer head
1063 * @skb: buffer to check
1065 * Return the number of bytes of free space at the head of an &sk_buff.
1067 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1069 return skb->data - skb->head;
1073 * skb_tailroom - bytes at buffer end
1074 * @skb: buffer to check
1076 * Return the number of bytes of free space at the tail of an sk_buff
1078 static inline int skb_tailroom(const struct sk_buff *skb)
1080 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1084 * skb_reserve - adjust headroom
1085 * @skb: buffer to alter
1086 * @len: bytes to move
1088 * Increase the headroom of an empty &sk_buff by reducing the tail
1089 * room. This is only allowed for an empty buffer.
1091 static inline void skb_reserve(struct sk_buff *skb, int len)
1097 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1098 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1100 return skb->head + skb->transport_header;
1103 static inline void skb_reset_transport_header(struct sk_buff *skb)
1105 skb->transport_header = skb->data - skb->head;
1108 static inline void skb_set_transport_header(struct sk_buff *skb,
1111 skb_reset_transport_header(skb);
1112 skb->transport_header += offset;
1115 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1117 return skb->head + skb->network_header;
1120 static inline void skb_reset_network_header(struct sk_buff *skb)
1122 skb->network_header = skb->data - skb->head;
1125 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1127 skb_reset_network_header(skb);
1128 skb->network_header += offset;
1131 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1133 return skb->head + skb->mac_header;
1136 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1138 return skb->mac_header != ~0U;
1141 static inline void skb_reset_mac_header(struct sk_buff *skb)
1143 skb->mac_header = skb->data - skb->head;
1146 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1148 skb_reset_mac_header(skb);
1149 skb->mac_header += offset;
1152 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1154 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1156 return skb->transport_header;
1159 static inline void skb_reset_transport_header(struct sk_buff *skb)
1161 skb->transport_header = skb->data;
1164 static inline void skb_set_transport_header(struct sk_buff *skb,
1167 skb->transport_header = skb->data + offset;
1170 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1172 return skb->network_header;
1175 static inline void skb_reset_network_header(struct sk_buff *skb)
1177 skb->network_header = skb->data;
1180 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1182 skb->network_header = skb->data + offset;
1185 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1187 return skb->mac_header;
1190 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1192 return skb->mac_header != NULL;
1195 static inline void skb_reset_mac_header(struct sk_buff *skb)
1197 skb->mac_header = skb->data;
1200 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1202 skb->mac_header = skb->data + offset;
1204 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1206 static inline int skb_transport_offset(const struct sk_buff *skb)
1208 return skb_transport_header(skb) - skb->data;
1211 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1213 return skb->transport_header - skb->network_header;
1216 static inline int skb_network_offset(const struct sk_buff *skb)
1218 return skb_network_header(skb) - skb->data;
1222 * CPUs often take a performance hit when accessing unaligned memory
1223 * locations. The actual performance hit varies, it can be small if the
1224 * hardware handles it or large if we have to take an exception and fix it
1227 * Since an ethernet header is 14 bytes network drivers often end up with
1228 * the IP header at an unaligned offset. The IP header can be aligned by
1229 * shifting the start of the packet by 2 bytes. Drivers should do this
1232 * skb_reserve(NET_IP_ALIGN);
1234 * The downside to this alignment of the IP header is that the DMA is now
1235 * unaligned. On some architectures the cost of an unaligned DMA is high
1236 * and this cost outweighs the gains made by aligning the IP header.
1238 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1241 #ifndef NET_IP_ALIGN
1242 #define NET_IP_ALIGN 2
1246 * The networking layer reserves some headroom in skb data (via
1247 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1248 * the header has to grow. In the default case, if the header has to grow
1249 * 16 bytes or less we avoid the reallocation.
1251 * Unfortunately this headroom changes the DMA alignment of the resulting
1252 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1253 * on some architectures. An architecture can override this value,
1254 * perhaps setting it to a cacheline in size (since that will maintain
1255 * cacheline alignment of the DMA). It must be a power of 2.
1257 * Various parts of the networking layer expect at least 16 bytes of
1258 * headroom, you should not reduce this.
1261 #define NET_SKB_PAD 16
1264 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1266 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1268 if (unlikely(skb->data_len)) {
1273 skb_set_tail_pointer(skb, len);
1276 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1278 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1281 return ___pskb_trim(skb, len);
1282 __skb_trim(skb, len);
1286 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1288 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1292 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1293 * @skb: buffer to alter
1296 * This is identical to pskb_trim except that the caller knows that
1297 * the skb is not cloned so we should never get an error due to out-
1300 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1302 int err = pskb_trim(skb, len);
1307 * skb_orphan - orphan a buffer
1308 * @skb: buffer to orphan
1310 * If a buffer currently has an owner then we call the owner's
1311 * destructor function and make the @skb unowned. The buffer continues
1312 * to exist but is no longer charged to its former owner.
1314 static inline void skb_orphan(struct sk_buff *skb)
1316 if (skb->destructor)
1317 skb->destructor(skb);
1318 skb->destructor = NULL;
1323 * __skb_queue_purge - empty a list
1324 * @list: list to empty
1326 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1327 * the list and one reference dropped. This function does not take the
1328 * list lock and the caller must hold the relevant locks to use it.
1330 extern void skb_queue_purge(struct sk_buff_head *list);
1331 static inline void __skb_queue_purge(struct sk_buff_head *list)
1333 struct sk_buff *skb;
1334 while ((skb = __skb_dequeue(list)) != NULL)
1339 * __dev_alloc_skb - allocate an skbuff for receiving
1340 * @length: length to allocate
1341 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1343 * Allocate a new &sk_buff and assign it a usage count of one. The
1344 * buffer has unspecified headroom built in. Users should allocate
1345 * the headroom they think they need without accounting for the
1346 * built in space. The built in space is used for optimisations.
1348 * %NULL is returned if there is no free memory.
1350 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1353 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1355 skb_reserve(skb, NET_SKB_PAD);
1359 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1361 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1362 unsigned int length, gfp_t gfp_mask);
1365 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1366 * @dev: network device to receive on
1367 * @length: length to allocate
1369 * Allocate a new &sk_buff and assign it a usage count of one. The
1370 * buffer has unspecified headroom built in. Users should allocate
1371 * the headroom they think they need without accounting for the
1372 * built in space. The built in space is used for optimisations.
1374 * %NULL is returned if there is no free memory. Although this function
1375 * allocates memory it can be called from an interrupt.
1377 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1378 unsigned int length)
1380 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1384 * skb_clone_writable - is the header of a clone writable
1385 * @skb: buffer to check
1386 * @len: length up to which to write
1388 * Returns true if modifying the header part of the cloned buffer
1389 * does not requires the data to be copied.
1391 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1393 return !skb_header_cloned(skb) &&
1394 skb_headroom(skb) + len <= skb->hdr_len;
1397 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1402 if (headroom < NET_SKB_PAD)
1403 headroom = NET_SKB_PAD;
1404 if (headroom > skb_headroom(skb))
1405 delta = headroom - skb_headroom(skb);
1407 if (delta || cloned)
1408 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1414 * skb_cow - copy header of skb when it is required
1415 * @skb: buffer to cow
1416 * @headroom: needed headroom
1418 * If the skb passed lacks sufficient headroom or its data part
1419 * is shared, data is reallocated. If reallocation fails, an error
1420 * is returned and original skb is not changed.
1422 * The result is skb with writable area skb->head...skb->tail
1423 * and at least @headroom of space at head.
1425 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1427 return __skb_cow(skb, headroom, skb_cloned(skb));
1431 * skb_cow_head - skb_cow but only making the head writable
1432 * @skb: buffer to cow
1433 * @headroom: needed headroom
1435 * This function is identical to skb_cow except that we replace the
1436 * skb_cloned check by skb_header_cloned. It should be used when
1437 * you only need to push on some header and do not need to modify
1440 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1442 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1446 * skb_padto - pad an skbuff up to a minimal size
1447 * @skb: buffer to pad
1448 * @len: minimal length
1450 * Pads up a buffer to ensure the trailing bytes exist and are
1451 * blanked. If the buffer already contains sufficient data it
1452 * is untouched. Otherwise it is extended. Returns zero on
1453 * success. The skb is freed on error.
1456 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1458 unsigned int size = skb->len;
1459 if (likely(size >= len))
1461 return skb_pad(skb, len - size);
1464 static inline int skb_add_data(struct sk_buff *skb,
1465 char __user *from, int copy)
1467 const int off = skb->len;
1469 if (skb->ip_summed == CHECKSUM_NONE) {
1471 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1474 skb->csum = csum_block_add(skb->csum, csum, off);
1477 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1480 __skb_trim(skb, off);
1484 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1485 struct page *page, int off)
1488 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1490 return page == frag->page &&
1491 off == frag->page_offset + frag->size;
1496 static inline int __skb_linearize(struct sk_buff *skb)
1498 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1502 * skb_linearize - convert paged skb to linear one
1503 * @skb: buffer to linarize
1505 * If there is no free memory -ENOMEM is returned, otherwise zero
1506 * is returned and the old skb data released.
1508 static inline int skb_linearize(struct sk_buff *skb)
1510 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1514 * skb_linearize_cow - make sure skb is linear and writable
1515 * @skb: buffer to process
1517 * If there is no free memory -ENOMEM is returned, otherwise zero
1518 * is returned and the old skb data released.
1520 static inline int skb_linearize_cow(struct sk_buff *skb)
1522 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1523 __skb_linearize(skb) : 0;
1527 * skb_postpull_rcsum - update checksum for received skb after pull
1528 * @skb: buffer to update
1529 * @start: start of data before pull
1530 * @len: length of data pulled
1532 * After doing a pull on a received packet, you need to call this to
1533 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1534 * CHECKSUM_NONE so that it can be recomputed from scratch.
1537 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1538 const void *start, unsigned int len)
1540 if (skb->ip_summed == CHECKSUM_COMPLETE)
1541 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1544 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1547 * pskb_trim_rcsum - trim received skb and update checksum
1548 * @skb: buffer to trim
1551 * This is exactly the same as pskb_trim except that it ensures the
1552 * checksum of received packets are still valid after the operation.
1555 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1557 if (likely(len >= skb->len))
1559 if (skb->ip_summed == CHECKSUM_COMPLETE)
1560 skb->ip_summed = CHECKSUM_NONE;
1561 return __pskb_trim(skb, len);
1564 #define skb_queue_walk(queue, skb) \
1565 for (skb = (queue)->next; \
1566 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1569 #define skb_queue_walk_safe(queue, skb, tmp) \
1570 for (skb = (queue)->next, tmp = skb->next; \
1571 skb != (struct sk_buff *)(queue); \
1572 skb = tmp, tmp = skb->next)
1574 #define skb_queue_walk_from(queue, skb) \
1575 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1578 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1579 for (tmp = skb->next; \
1580 skb != (struct sk_buff *)(queue); \
1581 skb = tmp, tmp = skb->next)
1583 #define skb_queue_reverse_walk(queue, skb) \
1584 for (skb = (queue)->prev; \
1585 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1589 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1590 int *peeked, int *err);
1591 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1592 int noblock, int *err);
1593 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1594 struct poll_table_struct *wait);
1595 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1596 int offset, struct iovec *to,
1598 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1601 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1605 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1606 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1607 unsigned int flags);
1608 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1609 int len, __wsum csum);
1610 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1612 extern int skb_store_bits(struct sk_buff *skb, int offset,
1613 const void *from, int len);
1614 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1615 int offset, u8 *to, int len,
1617 extern int skb_splice_bits(struct sk_buff *skb,
1618 unsigned int offset,
1619 struct pipe_inode_info *pipe,
1621 unsigned int flags);
1622 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1623 extern void skb_split(struct sk_buff *skb,
1624 struct sk_buff *skb1, const u32 len);
1626 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1628 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1629 int len, void *buffer)
1631 int hlen = skb_headlen(skb);
1633 if (hlen - offset >= len)
1634 return skb->data + offset;
1636 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1642 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1644 const unsigned int len)
1646 memcpy(to, skb->data, len);
1649 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1650 const int offset, void *to,
1651 const unsigned int len)
1653 memcpy(to, skb->data + offset, len);
1656 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1658 const unsigned int len)
1660 memcpy(skb->data, from, len);
1663 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1666 const unsigned int len)
1668 memcpy(skb->data + offset, from, len);
1671 extern void skb_init(void);
1674 * skb_get_timestamp - get timestamp from a skb
1675 * @skb: skb to get stamp from
1676 * @stamp: pointer to struct timeval to store stamp in
1678 * Timestamps are stored in the skb as offsets to a base timestamp.
1679 * This function converts the offset back to a struct timeval and stores
1682 static inline void skb_get_timestamp(const struct sk_buff *skb, struct timeval *stamp)
1684 *stamp = ktime_to_timeval(skb->tstamp);
1687 static inline void __net_timestamp(struct sk_buff *skb)
1689 skb->tstamp = ktime_get_real();
1692 static inline ktime_t net_timedelta(ktime_t t)
1694 return ktime_sub(ktime_get_real(), t);
1697 static inline ktime_t net_invalid_timestamp(void)
1699 return ktime_set(0, 0);
1702 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1703 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1705 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1707 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1711 * skb_checksum_complete - Calculate checksum of an entire packet
1712 * @skb: packet to process
1714 * This function calculates the checksum over the entire packet plus
1715 * the value of skb->csum. The latter can be used to supply the
1716 * checksum of a pseudo header as used by TCP/UDP. It returns the
1719 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1720 * this function can be used to verify that checksum on received
1721 * packets. In that case the function should return zero if the
1722 * checksum is correct. In particular, this function will return zero
1723 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1724 * hardware has already verified the correctness of the checksum.
1726 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1728 return skb_csum_unnecessary(skb) ?
1729 0 : __skb_checksum_complete(skb);
1732 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1733 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1734 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1736 if (nfct && atomic_dec_and_test(&nfct->use))
1737 nf_conntrack_destroy(nfct);
1739 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1742 atomic_inc(&nfct->use);
1744 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1747 atomic_inc(&skb->users);
1749 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1755 #ifdef CONFIG_BRIDGE_NETFILTER
1756 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1758 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1761 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1764 atomic_inc(&nf_bridge->use);
1766 #endif /* CONFIG_BRIDGE_NETFILTER */
1767 static inline void nf_reset(struct sk_buff *skb)
1769 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1770 nf_conntrack_put(skb->nfct);
1772 nf_conntrack_put_reasm(skb->nfct_reasm);
1773 skb->nfct_reasm = NULL;
1775 #ifdef CONFIG_BRIDGE_NETFILTER
1776 nf_bridge_put(skb->nf_bridge);
1777 skb->nf_bridge = NULL;
1781 /* Note: This doesn't put any conntrack and bridge info in dst. */
1782 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1784 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1785 dst->nfct = src->nfct;
1786 nf_conntrack_get(src->nfct);
1787 dst->nfctinfo = src->nfctinfo;
1788 dst->nfct_reasm = src->nfct_reasm;
1789 nf_conntrack_get_reasm(src->nfct_reasm);
1791 #ifdef CONFIG_BRIDGE_NETFILTER
1792 dst->nf_bridge = src->nf_bridge;
1793 nf_bridge_get(src->nf_bridge);
1797 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1799 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1800 nf_conntrack_put(dst->nfct);
1801 nf_conntrack_put_reasm(dst->nfct_reasm);
1803 #ifdef CONFIG_BRIDGE_NETFILTER
1804 nf_bridge_put(dst->nf_bridge);
1806 __nf_copy(dst, src);
1809 #ifdef CONFIG_NETWORK_SECMARK
1810 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1812 to->secmark = from->secmark;
1815 static inline void skb_init_secmark(struct sk_buff *skb)
1820 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1823 static inline void skb_init_secmark(struct sk_buff *skb)
1827 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1829 skb->queue_mapping = queue_mapping;
1832 static inline u16 skb_get_queue_mapping(struct sk_buff *skb)
1834 return skb->queue_mapping;
1837 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1839 to->queue_mapping = from->queue_mapping;
1842 static inline int skb_is_gso(const struct sk_buff *skb)
1844 return skb_shinfo(skb)->gso_size;
1847 static inline int skb_is_gso_v6(const struct sk_buff *skb)
1849 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
1852 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
1854 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
1856 /* LRO sets gso_size but not gso_type, whereas if GSO is really
1857 * wanted then gso_type will be set. */
1858 struct skb_shared_info *shinfo = skb_shinfo(skb);
1859 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
1860 __skb_warn_lro_forwarding(skb);
1866 static inline void skb_forward_csum(struct sk_buff *skb)
1868 /* Unfortunately we don't support this one. Any brave souls? */
1869 if (skb->ip_summed == CHECKSUM_COMPLETE)
1870 skb->ip_summed = CHECKSUM_NONE;
1873 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
1874 #endif /* __KERNEL__ */
1875 #endif /* _LINUX_SKBUFF_H */