2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/cache.h>
23 #include <asm/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/dmaengine.h>
31 #include <linux/hrtimer.h>
33 /* Don't change this without changing skb_csum_unnecessary! */
34 #define CHECKSUM_NONE 0
35 #define CHECKSUM_UNNECESSARY 1
36 #define CHECKSUM_COMPLETE 2
37 #define CHECKSUM_PARTIAL 3
39 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
40 ~(SMP_CACHE_BYTES - 1))
41 #define SKB_WITH_OVERHEAD(X) \
42 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
43 #define SKB_MAX_ORDER(X, ORDER) \
44 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
45 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
46 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
48 /* A. Checksumming of received packets by device.
50 * NONE: device failed to checksum this packet.
51 * skb->csum is undefined.
53 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
54 * skb->csum is undefined.
55 * It is bad option, but, unfortunately, many of vendors do this.
56 * Apparently with secret goal to sell you new device, when you
57 * will add new protocol to your host. F.e. IPv6. 8)
59 * COMPLETE: the most generic way. Device supplied checksum of _all_
60 * the packet as seen by netif_rx in skb->csum.
61 * NOTE: Even if device supports only some protocols, but
62 * is able to produce some skb->csum, it MUST use COMPLETE,
65 * PARTIAL: identical to the case for output below. This may occur
66 * on a packet received directly from another Linux OS, e.g.,
67 * a virtualised Linux kernel on the same host. The packet can
68 * be treated in the same way as UNNECESSARY except that on
69 * output (i.e., forwarding) the checksum must be filled in
70 * by the OS or the hardware.
72 * B. Checksumming on output.
74 * NONE: skb is checksummed by protocol or csum is not required.
76 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
77 * from skb->csum_start to the end and to record the checksum
78 * at skb->csum_start + skb->csum_offset.
80 * Device must show its capabilities in dev->features, set
81 * at device setup time.
82 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
84 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
85 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
86 * TCP/UDP over IPv4. Sigh. Vendors like this
87 * way by an unknown reason. Though, see comment above
88 * about CHECKSUM_UNNECESSARY. 8)
89 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
91 * Any questions? No questions, good. --ANK
96 struct pipe_inode_info;
98 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
104 #ifdef CONFIG_BRIDGE_NETFILTER
105 struct nf_bridge_info {
107 struct net_device *physindev;
108 struct net_device *physoutdev;
110 unsigned long data[32 / sizeof(unsigned long)];
114 struct sk_buff_head {
115 /* These two members must be first. */
116 struct sk_buff *next;
117 struct sk_buff *prev;
125 /* To allow 64K frame to be packed as single skb without frag_list */
126 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
128 typedef struct skb_frag_struct skb_frag_t;
130 struct skb_frag_struct {
136 #define HAVE_HW_TIME_STAMP
139 * struct skb_shared_hwtstamps - hardware time stamps
140 * @hwtstamp: hardware time stamp transformed into duration
141 * since arbitrary point in time
142 * @syststamp: hwtstamp transformed to system time base
144 * Software time stamps generated by ktime_get_real() are stored in
145 * skb->tstamp. The relation between the different kinds of time
146 * stamps is as follows:
148 * syststamp and tstamp can be compared against each other in
149 * arbitrary combinations. The accuracy of a
150 * syststamp/tstamp/"syststamp from other device" comparison is
151 * limited by the accuracy of the transformation into system time
152 * base. This depends on the device driver and its underlying
155 * hwtstamps can only be compared against other hwtstamps from
158 * This structure is attached to packets as part of the
159 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
161 struct skb_shared_hwtstamps {
167 * struct skb_shared_tx - instructions for time stamping of outgoing packets
168 * @hardware: generate hardware time stamp
169 * @software: generate software time stamp
170 * @in_progress: device driver is going to provide
171 * hardware time stamp
172 * @flags: all shared_tx flags
174 * These flags are attached to packets as part of the
175 * &skb_shared_info. Use skb_tx() to get a pointer.
177 union skb_shared_tx {
186 /* This data is invariant across clones and lives at
187 * the end of the header data, ie. at skb->end.
189 struct skb_shared_info {
191 unsigned short nr_frags;
192 unsigned short gso_size;
193 #ifdef CONFIG_HAS_DMA
196 /* Warning: this field is not always filled in (UFO)! */
197 unsigned short gso_segs;
198 unsigned short gso_type;
200 union skb_shared_tx tx_flags;
201 struct sk_buff *frag_list;
202 struct skb_shared_hwtstamps hwtstamps;
203 skb_frag_t frags[MAX_SKB_FRAGS];
204 #ifdef CONFIG_HAS_DMA
205 dma_addr_t dma_maps[MAX_SKB_FRAGS];
207 /* Intermediate layers must ensure that destructor_arg
208 * remains valid until skb destructor */
209 void * destructor_arg;
212 /* We divide dataref into two halves. The higher 16 bits hold references
213 * to the payload part of skb->data. The lower 16 bits hold references to
214 * the entire skb->data. A clone of a headerless skb holds the length of
215 * the header in skb->hdr_len.
217 * All users must obey the rule that the skb->data reference count must be
218 * greater than or equal to the payload reference count.
220 * Holding a reference to the payload part means that the user does not
221 * care about modifications to the header part of skb->data.
223 #define SKB_DATAREF_SHIFT 16
224 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
228 SKB_FCLONE_UNAVAILABLE,
234 SKB_GSO_TCPV4 = 1 << 0,
235 SKB_GSO_UDP = 1 << 1,
237 /* This indicates the skb is from an untrusted source. */
238 SKB_GSO_DODGY = 1 << 2,
240 /* This indicates the tcp segment has CWR set. */
241 SKB_GSO_TCP_ECN = 1 << 3,
243 SKB_GSO_TCPV6 = 1 << 4,
245 SKB_GSO_FCOE = 1 << 5,
248 #if BITS_PER_LONG > 32
249 #define NET_SKBUFF_DATA_USES_OFFSET 1
252 #ifdef NET_SKBUFF_DATA_USES_OFFSET
253 typedef unsigned int sk_buff_data_t;
255 typedef unsigned char *sk_buff_data_t;
259 * struct sk_buff - socket buffer
260 * @next: Next buffer in list
261 * @prev: Previous buffer in list
262 * @sk: Socket we are owned by
263 * @tstamp: Time we arrived
264 * @dev: Device we arrived on/are leaving by
265 * @transport_header: Transport layer header
266 * @network_header: Network layer header
267 * @mac_header: Link layer header
268 * @_skb_dst: destination entry
269 * @sp: the security path, used for xfrm
270 * @cb: Control buffer. Free for use by every layer. Put private vars here
271 * @len: Length of actual data
272 * @data_len: Data length
273 * @mac_len: Length of link layer header
274 * @hdr_len: writable header length of cloned skb
275 * @csum: Checksum (must include start/offset pair)
276 * @csum_start: Offset from skb->head where checksumming should start
277 * @csum_offset: Offset from csum_start where checksum should be stored
278 * @local_df: allow local fragmentation
279 * @cloned: Head may be cloned (check refcnt to be sure)
280 * @nohdr: Payload reference only, must not modify header
281 * @pkt_type: Packet class
282 * @fclone: skbuff clone status
283 * @ip_summed: Driver fed us an IP checksum
284 * @priority: Packet queueing priority
285 * @users: User count - see {datagram,tcp}.c
286 * @protocol: Packet protocol from driver
287 * @truesize: Buffer size
288 * @head: Head of buffer
289 * @data: Data head pointer
290 * @tail: Tail pointer
292 * @destructor: Destruct function
293 * @mark: Generic packet mark
294 * @nfct: Associated connection, if any
295 * @ipvs_property: skbuff is owned by ipvs
296 * @peeked: this packet has been seen already, so stats have been
297 * done for it, don't do them again
298 * @nf_trace: netfilter packet trace flag
299 * @nfctinfo: Relationship of this skb to the connection
300 * @nfct_reasm: netfilter conntrack re-assembly pointer
301 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
302 * @skb_iif: ifindex of device we arrived on
303 * @rxhash: the packet hash computed on receive
304 * @queue_mapping: Queue mapping for multiqueue devices
305 * @tc_index: Traffic control index
306 * @tc_verd: traffic control verdict
307 * @ndisc_nodetype: router type (from link layer)
308 * @dma_cookie: a cookie to one of several possible DMA operations
309 * done by skb DMA functions
310 * @secmark: security marking
311 * @vlan_tci: vlan tag control information
315 /* These two members must be first. */
316 struct sk_buff *next;
317 struct sk_buff *prev;
322 struct net_device *dev;
325 * This is the control buffer. It is free to use for every
326 * layer. Please put your private variables there. If you
327 * want to keep them across layers you have to do a skb_clone()
328 * first. This is owned by whoever has the skb queued ATM.
330 char cb[48] __aligned(8);
332 unsigned long _skb_dst;
348 kmemcheck_bitfield_begin(flags1);
359 kmemcheck_bitfield_end(flags1);
362 void (*destructor)(struct sk_buff *skb);
363 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
364 struct nf_conntrack *nfct;
365 struct sk_buff *nfct_reasm;
367 #ifdef CONFIG_BRIDGE_NETFILTER
368 struct nf_bridge_info *nf_bridge;
372 #ifdef CONFIG_NET_SCHED
373 __u16 tc_index; /* traffic control index */
374 #ifdef CONFIG_NET_CLS_ACT
375 __u16 tc_verd; /* traffic control verdict */
381 kmemcheck_bitfield_begin(flags2);
382 __u16 queue_mapping:16;
383 #ifdef CONFIG_IPV6_NDISC_NODETYPE
384 __u8 ndisc_nodetype:2;
386 kmemcheck_bitfield_end(flags2);
390 #ifdef CONFIG_NET_DMA
391 dma_cookie_t dma_cookie;
393 #ifdef CONFIG_NETWORK_SECMARK
403 sk_buff_data_t transport_header;
404 sk_buff_data_t network_header;
405 sk_buff_data_t mac_header;
406 /* These elements must be at the end, see alloc_skb() for details. */
411 unsigned int truesize;
417 * Handling routines are only of interest to the kernel
419 #include <linux/slab.h>
421 #include <asm/system.h>
423 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
425 return (struct dst_entry *)skb->_skb_dst;
428 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
430 skb->_skb_dst = (unsigned long)dst;
433 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
435 return (struct rtable *)skb_dst(skb);
438 extern void kfree_skb(struct sk_buff *skb);
439 extern void consume_skb(struct sk_buff *skb);
440 extern void __kfree_skb(struct sk_buff *skb);
441 extern struct sk_buff *__alloc_skb(unsigned int size,
442 gfp_t priority, int fclone, int node);
443 static inline struct sk_buff *alloc_skb(unsigned int size,
446 return __alloc_skb(size, priority, 0, -1);
449 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
452 return __alloc_skb(size, priority, 1, -1);
455 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
457 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
458 extern struct sk_buff *skb_clone(struct sk_buff *skb,
460 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
462 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
464 extern int pskb_expand_head(struct sk_buff *skb,
465 int nhead, int ntail,
467 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
468 unsigned int headroom);
469 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
470 int newheadroom, int newtailroom,
472 extern int skb_to_sgvec(struct sk_buff *skb,
473 struct scatterlist *sg, int offset,
475 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
476 struct sk_buff **trailer);
477 extern int skb_pad(struct sk_buff *skb, int pad);
478 #define dev_kfree_skb(a) consume_skb(a)
479 #define dev_consume_skb(a) kfree_skb_clean(a)
480 extern void skb_over_panic(struct sk_buff *skb, int len,
482 extern void skb_under_panic(struct sk_buff *skb, int len,
485 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
486 int getfrag(void *from, char *to, int offset,
487 int len,int odd, struct sk_buff *skb),
488 void *from, int length);
490 struct skb_seq_state {
494 __u32 stepped_offset;
495 struct sk_buff *root_skb;
496 struct sk_buff *cur_skb;
500 extern void skb_prepare_seq_read(struct sk_buff *skb,
501 unsigned int from, unsigned int to,
502 struct skb_seq_state *st);
503 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
504 struct skb_seq_state *st);
505 extern void skb_abort_seq_read(struct skb_seq_state *st);
507 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
508 unsigned int to, struct ts_config *config,
509 struct ts_state *state);
511 #ifdef NET_SKBUFF_DATA_USES_OFFSET
512 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
514 return skb->head + skb->end;
517 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
524 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
526 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
528 return &skb_shinfo(skb)->hwtstamps;
531 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
533 return &skb_shinfo(skb)->tx_flags;
537 * skb_queue_empty - check if a queue is empty
540 * Returns true if the queue is empty, false otherwise.
542 static inline int skb_queue_empty(const struct sk_buff_head *list)
544 return list->next == (struct sk_buff *)list;
548 * skb_queue_is_last - check if skb is the last entry in the queue
552 * Returns true if @skb is the last buffer on the list.
554 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
555 const struct sk_buff *skb)
557 return (skb->next == (struct sk_buff *) list);
561 * skb_queue_is_first - check if skb is the first entry in the queue
565 * Returns true if @skb is the first buffer on the list.
567 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
568 const struct sk_buff *skb)
570 return (skb->prev == (struct sk_buff *) list);
574 * skb_queue_next - return the next packet in the queue
576 * @skb: current buffer
578 * Return the next packet in @list after @skb. It is only valid to
579 * call this if skb_queue_is_last() evaluates to false.
581 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
582 const struct sk_buff *skb)
584 /* This BUG_ON may seem severe, but if we just return then we
585 * are going to dereference garbage.
587 BUG_ON(skb_queue_is_last(list, skb));
592 * skb_queue_prev - return the prev packet in the queue
594 * @skb: current buffer
596 * Return the prev packet in @list before @skb. It is only valid to
597 * call this if skb_queue_is_first() evaluates to false.
599 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
600 const struct sk_buff *skb)
602 /* This BUG_ON may seem severe, but if we just return then we
603 * are going to dereference garbage.
605 BUG_ON(skb_queue_is_first(list, skb));
610 * skb_get - reference buffer
611 * @skb: buffer to reference
613 * Makes another reference to a socket buffer and returns a pointer
616 static inline struct sk_buff *skb_get(struct sk_buff *skb)
618 atomic_inc(&skb->users);
623 * If users == 1, we are the only owner and are can avoid redundant
628 * skb_cloned - is the buffer a clone
629 * @skb: buffer to check
631 * Returns true if the buffer was generated with skb_clone() and is
632 * one of multiple shared copies of the buffer. Cloned buffers are
633 * shared data so must not be written to under normal circumstances.
635 static inline int skb_cloned(const struct sk_buff *skb)
637 return skb->cloned &&
638 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
642 * skb_header_cloned - is the header a clone
643 * @skb: buffer to check
645 * Returns true if modifying the header part of the buffer requires
646 * the data to be copied.
648 static inline int skb_header_cloned(const struct sk_buff *skb)
655 dataref = atomic_read(&skb_shinfo(skb)->dataref);
656 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
661 * skb_header_release - release reference to header
662 * @skb: buffer to operate on
664 * Drop a reference to the header part of the buffer. This is done
665 * by acquiring a payload reference. You must not read from the header
666 * part of skb->data after this.
668 static inline void skb_header_release(struct sk_buff *skb)
672 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
676 * skb_shared - is the buffer shared
677 * @skb: buffer to check
679 * Returns true if more than one person has a reference to this
682 static inline int skb_shared(const struct sk_buff *skb)
684 return atomic_read(&skb->users) != 1;
688 * skb_share_check - check if buffer is shared and if so clone it
689 * @skb: buffer to check
690 * @pri: priority for memory allocation
692 * If the buffer is shared the buffer is cloned and the old copy
693 * drops a reference. A new clone with a single reference is returned.
694 * If the buffer is not shared the original buffer is returned. When
695 * being called from interrupt status or with spinlocks held pri must
698 * NULL is returned on a memory allocation failure.
700 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
703 might_sleep_if(pri & __GFP_WAIT);
704 if (skb_shared(skb)) {
705 struct sk_buff *nskb = skb_clone(skb, pri);
713 * Copy shared buffers into a new sk_buff. We effectively do COW on
714 * packets to handle cases where we have a local reader and forward
715 * and a couple of other messy ones. The normal one is tcpdumping
716 * a packet thats being forwarded.
720 * skb_unshare - make a copy of a shared buffer
721 * @skb: buffer to check
722 * @pri: priority for memory allocation
724 * If the socket buffer is a clone then this function creates a new
725 * copy of the data, drops a reference count on the old copy and returns
726 * the new copy with the reference count at 1. If the buffer is not a clone
727 * the original buffer is returned. When called with a spinlock held or
728 * from interrupt state @pri must be %GFP_ATOMIC
730 * %NULL is returned on a memory allocation failure.
732 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
735 might_sleep_if(pri & __GFP_WAIT);
736 if (skb_cloned(skb)) {
737 struct sk_buff *nskb = skb_copy(skb, pri);
738 kfree_skb(skb); /* Free our shared copy */
745 * skb_peek - peek at the head of an &sk_buff_head
746 * @list_: list to peek at
748 * Peek an &sk_buff. Unlike most other operations you _MUST_
749 * be careful with this one. A peek leaves the buffer on the
750 * list and someone else may run off with it. You must hold
751 * the appropriate locks or have a private queue to do this.
753 * Returns %NULL for an empty list or a pointer to the head element.
754 * The reference count is not incremented and the reference is therefore
755 * volatile. Use with caution.
757 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
759 struct sk_buff *list = ((struct sk_buff *)list_)->next;
760 if (list == (struct sk_buff *)list_)
766 * skb_peek_tail - peek at the tail of an &sk_buff_head
767 * @list_: list to peek at
769 * Peek an &sk_buff. Unlike most other operations you _MUST_
770 * be careful with this one. A peek leaves the buffer on the
771 * list and someone else may run off with it. You must hold
772 * the appropriate locks or have a private queue to do this.
774 * Returns %NULL for an empty list or a pointer to the tail element.
775 * The reference count is not incremented and the reference is therefore
776 * volatile. Use with caution.
778 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
780 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
781 if (list == (struct sk_buff *)list_)
787 * skb_queue_len - get queue length
788 * @list_: list to measure
790 * Return the length of an &sk_buff queue.
792 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
798 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
799 * @list: queue to initialize
801 * This initializes only the list and queue length aspects of
802 * an sk_buff_head object. This allows to initialize the list
803 * aspects of an sk_buff_head without reinitializing things like
804 * the spinlock. It can also be used for on-stack sk_buff_head
805 * objects where the spinlock is known to not be used.
807 static inline void __skb_queue_head_init(struct sk_buff_head *list)
809 list->prev = list->next = (struct sk_buff *)list;
814 * This function creates a split out lock class for each invocation;
815 * this is needed for now since a whole lot of users of the skb-queue
816 * infrastructure in drivers have different locking usage (in hardirq)
817 * than the networking core (in softirq only). In the long run either the
818 * network layer or drivers should need annotation to consolidate the
819 * main types of usage into 3 classes.
821 static inline void skb_queue_head_init(struct sk_buff_head *list)
823 spin_lock_init(&list->lock);
824 __skb_queue_head_init(list);
827 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
828 struct lock_class_key *class)
830 skb_queue_head_init(list);
831 lockdep_set_class(&list->lock, class);
835 * Insert an sk_buff on a list.
837 * The "__skb_xxxx()" functions are the non-atomic ones that
838 * can only be called with interrupts disabled.
840 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
841 static inline void __skb_insert(struct sk_buff *newsk,
842 struct sk_buff *prev, struct sk_buff *next,
843 struct sk_buff_head *list)
847 next->prev = prev->next = newsk;
851 static inline void __skb_queue_splice(const struct sk_buff_head *list,
852 struct sk_buff *prev,
853 struct sk_buff *next)
855 struct sk_buff *first = list->next;
856 struct sk_buff *last = list->prev;
866 * skb_queue_splice - join two skb lists, this is designed for stacks
867 * @list: the new list to add
868 * @head: the place to add it in the first list
870 static inline void skb_queue_splice(const struct sk_buff_head *list,
871 struct sk_buff_head *head)
873 if (!skb_queue_empty(list)) {
874 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
875 head->qlen += list->qlen;
880 * skb_queue_splice - join two skb lists and reinitialise the emptied list
881 * @list: the new list to add
882 * @head: the place to add it in the first list
884 * The list at @list is reinitialised
886 static inline void skb_queue_splice_init(struct sk_buff_head *list,
887 struct sk_buff_head *head)
889 if (!skb_queue_empty(list)) {
890 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
891 head->qlen += list->qlen;
892 __skb_queue_head_init(list);
897 * skb_queue_splice_tail - join two skb lists, each list being a queue
898 * @list: the new list to add
899 * @head: the place to add it in the first list
901 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
902 struct sk_buff_head *head)
904 if (!skb_queue_empty(list)) {
905 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
906 head->qlen += list->qlen;
911 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
912 * @list: the new list to add
913 * @head: the place to add it in the first list
915 * Each of the lists is a queue.
916 * The list at @list is reinitialised
918 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
919 struct sk_buff_head *head)
921 if (!skb_queue_empty(list)) {
922 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
923 head->qlen += list->qlen;
924 __skb_queue_head_init(list);
929 * __skb_queue_after - queue a buffer at the list head
931 * @prev: place after this buffer
932 * @newsk: buffer to queue
934 * Queue a buffer int the middle of a list. This function takes no locks
935 * and you must therefore hold required locks before calling it.
937 * A buffer cannot be placed on two lists at the same time.
939 static inline void __skb_queue_after(struct sk_buff_head *list,
940 struct sk_buff *prev,
941 struct sk_buff *newsk)
943 __skb_insert(newsk, prev, prev->next, list);
946 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
947 struct sk_buff_head *list);
949 static inline void __skb_queue_before(struct sk_buff_head *list,
950 struct sk_buff *next,
951 struct sk_buff *newsk)
953 __skb_insert(newsk, next->prev, next, list);
957 * __skb_queue_head - queue a buffer at the list head
959 * @newsk: buffer to queue
961 * Queue a buffer at the start of a list. This function takes no locks
962 * and you must therefore hold required locks before calling it.
964 * A buffer cannot be placed on two lists at the same time.
966 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
967 static inline void __skb_queue_head(struct sk_buff_head *list,
968 struct sk_buff *newsk)
970 __skb_queue_after(list, (struct sk_buff *)list, newsk);
974 * __skb_queue_tail - queue a buffer at the list tail
976 * @newsk: buffer to queue
978 * Queue a buffer at the end of a list. This function takes no locks
979 * and you must therefore hold required locks before calling it.
981 * A buffer cannot be placed on two lists at the same time.
983 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
984 static inline void __skb_queue_tail(struct sk_buff_head *list,
985 struct sk_buff *newsk)
987 __skb_queue_before(list, (struct sk_buff *)list, newsk);
991 * remove sk_buff from list. _Must_ be called atomically, and with
994 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
995 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
997 struct sk_buff *next, *prev;
1002 skb->next = skb->prev = NULL;
1008 * __skb_dequeue - remove from the head of the queue
1009 * @list: list to dequeue from
1011 * Remove the head of the list. This function does not take any locks
1012 * so must be used with appropriate locks held only. The head item is
1013 * returned or %NULL if the list is empty.
1015 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1016 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1018 struct sk_buff *skb = skb_peek(list);
1020 __skb_unlink(skb, list);
1025 * __skb_dequeue_tail - remove from the tail of the queue
1026 * @list: list to dequeue from
1028 * Remove the tail of the list. This function does not take any locks
1029 * so must be used with appropriate locks held only. The tail item is
1030 * returned or %NULL if the list is empty.
1032 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1033 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1035 struct sk_buff *skb = skb_peek_tail(list);
1037 __skb_unlink(skb, list);
1042 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1044 return skb->data_len;
1047 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1049 return skb->len - skb->data_len;
1052 static inline int skb_pagelen(const struct sk_buff *skb)
1056 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1057 len += skb_shinfo(skb)->frags[i].size;
1058 return len + skb_headlen(skb);
1061 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1062 struct page *page, int off, int size)
1064 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1067 frag->page_offset = off;
1069 skb_shinfo(skb)->nr_frags = i + 1;
1072 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1075 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1076 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frags(skb))
1077 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1079 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1080 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1082 return skb->head + skb->tail;
1085 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1087 skb->tail = skb->data - skb->head;
1090 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1092 skb_reset_tail_pointer(skb);
1093 skb->tail += offset;
1095 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1096 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1101 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1103 skb->tail = skb->data;
1106 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1108 skb->tail = skb->data + offset;
1111 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1114 * Add data to an sk_buff
1116 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1117 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1119 unsigned char *tmp = skb_tail_pointer(skb);
1120 SKB_LINEAR_ASSERT(skb);
1126 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1127 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1134 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1135 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1138 BUG_ON(skb->len < skb->data_len);
1139 return skb->data += len;
1142 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1144 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1146 if (len > skb_headlen(skb) &&
1147 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1150 return skb->data += len;
1153 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1155 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1158 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1160 if (likely(len <= skb_headlen(skb)))
1162 if (unlikely(len > skb->len))
1164 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1168 * skb_headroom - bytes at buffer head
1169 * @skb: buffer to check
1171 * Return the number of bytes of free space at the head of an &sk_buff.
1173 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1175 return skb->data - skb->head;
1179 * skb_tailroom - bytes at buffer end
1180 * @skb: buffer to check
1182 * Return the number of bytes of free space at the tail of an sk_buff
1184 static inline int skb_tailroom(const struct sk_buff *skb)
1186 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1190 * skb_reserve - adjust headroom
1191 * @skb: buffer to alter
1192 * @len: bytes to move
1194 * Increase the headroom of an empty &sk_buff by reducing the tail
1195 * room. This is only allowed for an empty buffer.
1197 static inline void skb_reserve(struct sk_buff *skb, int len)
1203 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1204 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1206 return skb->head + skb->transport_header;
1209 static inline void skb_reset_transport_header(struct sk_buff *skb)
1211 skb->transport_header = skb->data - skb->head;
1214 static inline void skb_set_transport_header(struct sk_buff *skb,
1217 skb_reset_transport_header(skb);
1218 skb->transport_header += offset;
1221 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1223 return skb->head + skb->network_header;
1226 static inline void skb_reset_network_header(struct sk_buff *skb)
1228 skb->network_header = skb->data - skb->head;
1231 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1233 skb_reset_network_header(skb);
1234 skb->network_header += offset;
1237 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1239 return skb->head + skb->mac_header;
1242 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1244 return skb->mac_header != ~0U;
1247 static inline void skb_reset_mac_header(struct sk_buff *skb)
1249 skb->mac_header = skb->data - skb->head;
1252 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1254 skb_reset_mac_header(skb);
1255 skb->mac_header += offset;
1258 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1260 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1262 return skb->transport_header;
1265 static inline void skb_reset_transport_header(struct sk_buff *skb)
1267 skb->transport_header = skb->data;
1270 static inline void skb_set_transport_header(struct sk_buff *skb,
1273 skb->transport_header = skb->data + offset;
1276 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1278 return skb->network_header;
1281 static inline void skb_reset_network_header(struct sk_buff *skb)
1283 skb->network_header = skb->data;
1286 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1288 skb->network_header = skb->data + offset;
1291 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1293 return skb->mac_header;
1296 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1298 return skb->mac_header != NULL;
1301 static inline void skb_reset_mac_header(struct sk_buff *skb)
1303 skb->mac_header = skb->data;
1306 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1308 skb->mac_header = skb->data + offset;
1310 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1312 static inline int skb_transport_offset(const struct sk_buff *skb)
1314 return skb_transport_header(skb) - skb->data;
1317 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1319 return skb->transport_header - skb->network_header;
1322 static inline int skb_network_offset(const struct sk_buff *skb)
1324 return skb_network_header(skb) - skb->data;
1328 * CPUs often take a performance hit when accessing unaligned memory
1329 * locations. The actual performance hit varies, it can be small if the
1330 * hardware handles it or large if we have to take an exception and fix it
1333 * Since an ethernet header is 14 bytes network drivers often end up with
1334 * the IP header at an unaligned offset. The IP header can be aligned by
1335 * shifting the start of the packet by 2 bytes. Drivers should do this
1338 * skb_reserve(skb, NET_IP_ALIGN);
1340 * The downside to this alignment of the IP header is that the DMA is now
1341 * unaligned. On some architectures the cost of an unaligned DMA is high
1342 * and this cost outweighs the gains made by aligning the IP header.
1344 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1347 #ifndef NET_IP_ALIGN
1348 #define NET_IP_ALIGN 2
1352 * The networking layer reserves some headroom in skb data (via
1353 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1354 * the header has to grow. In the default case, if the header has to grow
1355 * 32 bytes or less we avoid the reallocation.
1357 * Unfortunately this headroom changes the DMA alignment of the resulting
1358 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1359 * on some architectures. An architecture can override this value,
1360 * perhaps setting it to a cacheline in size (since that will maintain
1361 * cacheline alignment of the DMA). It must be a power of 2.
1363 * Various parts of the networking layer expect at least 32 bytes of
1364 * headroom, you should not reduce this.
1367 #define NET_SKB_PAD 32
1370 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1372 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1374 if (unlikely(skb->data_len)) {
1379 skb_set_tail_pointer(skb, len);
1382 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1384 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1387 return ___pskb_trim(skb, len);
1388 __skb_trim(skb, len);
1392 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1394 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1398 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1399 * @skb: buffer to alter
1402 * This is identical to pskb_trim except that the caller knows that
1403 * the skb is not cloned so we should never get an error due to out-
1406 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1408 int err = pskb_trim(skb, len);
1413 * skb_orphan - orphan a buffer
1414 * @skb: buffer to orphan
1416 * If a buffer currently has an owner then we call the owner's
1417 * destructor function and make the @skb unowned. The buffer continues
1418 * to exist but is no longer charged to its former owner.
1420 static inline void skb_orphan(struct sk_buff *skb)
1422 if (skb->destructor)
1423 skb->destructor(skb);
1424 skb->destructor = NULL;
1429 * __skb_queue_purge - empty a list
1430 * @list: list to empty
1432 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1433 * the list and one reference dropped. This function does not take the
1434 * list lock and the caller must hold the relevant locks to use it.
1436 extern void skb_queue_purge(struct sk_buff_head *list);
1437 static inline void __skb_queue_purge(struct sk_buff_head *list)
1439 struct sk_buff *skb;
1440 while ((skb = __skb_dequeue(list)) != NULL)
1445 * __dev_alloc_skb - allocate an skbuff for receiving
1446 * @length: length to allocate
1447 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1449 * Allocate a new &sk_buff and assign it a usage count of one. The
1450 * buffer has unspecified headroom built in. Users should allocate
1451 * the headroom they think they need without accounting for the
1452 * built in space. The built in space is used for optimisations.
1454 * %NULL is returned if there is no free memory.
1456 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1459 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1461 skb_reserve(skb, NET_SKB_PAD);
1465 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1467 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1468 unsigned int length, gfp_t gfp_mask);
1471 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1472 * @dev: network device to receive on
1473 * @length: length to allocate
1475 * Allocate a new &sk_buff and assign it a usage count of one. The
1476 * buffer has unspecified headroom built in. Users should allocate
1477 * the headroom they think they need without accounting for the
1478 * built in space. The built in space is used for optimisations.
1480 * %NULL is returned if there is no free memory. Although this function
1481 * allocates memory it can be called from an interrupt.
1483 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1484 unsigned int length)
1486 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1489 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1490 unsigned int length)
1492 struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN);
1494 if (NET_IP_ALIGN && skb)
1495 skb_reserve(skb, NET_IP_ALIGN);
1499 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1502 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1503 * @dev: network device to receive on
1505 * Allocate a new page node local to the specified device.
1507 * %NULL is returned if there is no free memory.
1509 static inline struct page *netdev_alloc_page(struct net_device *dev)
1511 return __netdev_alloc_page(dev, GFP_ATOMIC);
1514 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1520 * skb_clone_writable - is the header of a clone writable
1521 * @skb: buffer to check
1522 * @len: length up to which to write
1524 * Returns true if modifying the header part of the cloned buffer
1525 * does not requires the data to be copied.
1527 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1529 return !skb_header_cloned(skb) &&
1530 skb_headroom(skb) + len <= skb->hdr_len;
1533 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1538 if (headroom < NET_SKB_PAD)
1539 headroom = NET_SKB_PAD;
1540 if (headroom > skb_headroom(skb))
1541 delta = headroom - skb_headroom(skb);
1543 if (delta || cloned)
1544 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1550 * skb_cow - copy header of skb when it is required
1551 * @skb: buffer to cow
1552 * @headroom: needed headroom
1554 * If the skb passed lacks sufficient headroom or its data part
1555 * is shared, data is reallocated. If reallocation fails, an error
1556 * is returned and original skb is not changed.
1558 * The result is skb with writable area skb->head...skb->tail
1559 * and at least @headroom of space at head.
1561 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1563 return __skb_cow(skb, headroom, skb_cloned(skb));
1567 * skb_cow_head - skb_cow but only making the head writable
1568 * @skb: buffer to cow
1569 * @headroom: needed headroom
1571 * This function is identical to skb_cow except that we replace the
1572 * skb_cloned check by skb_header_cloned. It should be used when
1573 * you only need to push on some header and do not need to modify
1576 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1578 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1582 * skb_padto - pad an skbuff up to a minimal size
1583 * @skb: buffer to pad
1584 * @len: minimal length
1586 * Pads up a buffer to ensure the trailing bytes exist and are
1587 * blanked. If the buffer already contains sufficient data it
1588 * is untouched. Otherwise it is extended. Returns zero on
1589 * success. The skb is freed on error.
1592 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1594 unsigned int size = skb->len;
1595 if (likely(size >= len))
1597 return skb_pad(skb, len - size);
1600 static inline int skb_add_data(struct sk_buff *skb,
1601 char __user *from, int copy)
1603 const int off = skb->len;
1605 if (skb->ip_summed == CHECKSUM_NONE) {
1607 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1610 skb->csum = csum_block_add(skb->csum, csum, off);
1613 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1616 __skb_trim(skb, off);
1620 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1621 struct page *page, int off)
1624 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1626 return page == frag->page &&
1627 off == frag->page_offset + frag->size;
1632 static inline int __skb_linearize(struct sk_buff *skb)
1634 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1638 * skb_linearize - convert paged skb to linear one
1639 * @skb: buffer to linarize
1641 * If there is no free memory -ENOMEM is returned, otherwise zero
1642 * is returned and the old skb data released.
1644 static inline int skb_linearize(struct sk_buff *skb)
1646 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1650 * skb_linearize_cow - make sure skb is linear and writable
1651 * @skb: buffer to process
1653 * If there is no free memory -ENOMEM is returned, otherwise zero
1654 * is returned and the old skb data released.
1656 static inline int skb_linearize_cow(struct sk_buff *skb)
1658 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1659 __skb_linearize(skb) : 0;
1663 * skb_postpull_rcsum - update checksum for received skb after pull
1664 * @skb: buffer to update
1665 * @start: start of data before pull
1666 * @len: length of data pulled
1668 * After doing a pull on a received packet, you need to call this to
1669 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1670 * CHECKSUM_NONE so that it can be recomputed from scratch.
1673 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1674 const void *start, unsigned int len)
1676 if (skb->ip_summed == CHECKSUM_COMPLETE)
1677 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1680 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1683 * pskb_trim_rcsum - trim received skb and update checksum
1684 * @skb: buffer to trim
1687 * This is exactly the same as pskb_trim except that it ensures the
1688 * checksum of received packets are still valid after the operation.
1691 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1693 if (likely(len >= skb->len))
1695 if (skb->ip_summed == CHECKSUM_COMPLETE)
1696 skb->ip_summed = CHECKSUM_NONE;
1697 return __pskb_trim(skb, len);
1700 #define skb_queue_walk(queue, skb) \
1701 for (skb = (queue)->next; \
1702 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1705 #define skb_queue_walk_safe(queue, skb, tmp) \
1706 for (skb = (queue)->next, tmp = skb->next; \
1707 skb != (struct sk_buff *)(queue); \
1708 skb = tmp, tmp = skb->next)
1710 #define skb_queue_walk_from(queue, skb) \
1711 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1714 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1715 for (tmp = skb->next; \
1716 skb != (struct sk_buff *)(queue); \
1717 skb = tmp, tmp = skb->next)
1719 #define skb_queue_reverse_walk(queue, skb) \
1720 for (skb = (queue)->prev; \
1721 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1725 static inline bool skb_has_frags(const struct sk_buff *skb)
1727 return skb_shinfo(skb)->frag_list != NULL;
1730 static inline void skb_frag_list_init(struct sk_buff *skb)
1732 skb_shinfo(skb)->frag_list = NULL;
1735 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
1737 frag->next = skb_shinfo(skb)->frag_list;
1738 skb_shinfo(skb)->frag_list = frag;
1741 #define skb_walk_frags(skb, iter) \
1742 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
1744 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1745 int *peeked, int *err);
1746 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1747 int noblock, int *err);
1748 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1749 struct poll_table_struct *wait);
1750 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1751 int offset, struct iovec *to,
1753 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1756 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1758 const struct iovec *from,
1761 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
1763 const struct iovec *to,
1766 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1767 extern void skb_free_datagram_locked(struct sock *sk,
1768 struct sk_buff *skb);
1769 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1770 unsigned int flags);
1771 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1772 int len, __wsum csum);
1773 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1775 extern int skb_store_bits(struct sk_buff *skb, int offset,
1776 const void *from, int len);
1777 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1778 int offset, u8 *to, int len,
1780 extern int skb_splice_bits(struct sk_buff *skb,
1781 unsigned int offset,
1782 struct pipe_inode_info *pipe,
1784 unsigned int flags);
1785 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1786 extern void skb_split(struct sk_buff *skb,
1787 struct sk_buff *skb1, const u32 len);
1788 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1791 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1793 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1794 int len, void *buffer)
1796 int hlen = skb_headlen(skb);
1798 if (hlen - offset >= len)
1799 return skb->data + offset;
1801 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1807 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1809 const unsigned int len)
1811 memcpy(to, skb->data, len);
1814 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1815 const int offset, void *to,
1816 const unsigned int len)
1818 memcpy(to, skb->data + offset, len);
1821 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1823 const unsigned int len)
1825 memcpy(skb->data, from, len);
1828 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1831 const unsigned int len)
1833 memcpy(skb->data + offset, from, len);
1836 extern void skb_init(void);
1838 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1844 * skb_get_timestamp - get timestamp from a skb
1845 * @skb: skb to get stamp from
1846 * @stamp: pointer to struct timeval to store stamp in
1848 * Timestamps are stored in the skb as offsets to a base timestamp.
1849 * This function converts the offset back to a struct timeval and stores
1852 static inline void skb_get_timestamp(const struct sk_buff *skb,
1853 struct timeval *stamp)
1855 *stamp = ktime_to_timeval(skb->tstamp);
1858 static inline void skb_get_timestampns(const struct sk_buff *skb,
1859 struct timespec *stamp)
1861 *stamp = ktime_to_timespec(skb->tstamp);
1864 static inline void __net_timestamp(struct sk_buff *skb)
1866 skb->tstamp = ktime_get_real();
1869 static inline ktime_t net_timedelta(ktime_t t)
1871 return ktime_sub(ktime_get_real(), t);
1874 static inline ktime_t net_invalid_timestamp(void)
1876 return ktime_set(0, 0);
1880 * skb_tstamp_tx - queue clone of skb with send time stamps
1881 * @orig_skb: the original outgoing packet
1882 * @hwtstamps: hardware time stamps, may be NULL if not available
1884 * If the skb has a socket associated, then this function clones the
1885 * skb (thus sharing the actual data and optional structures), stores
1886 * the optional hardware time stamping information (if non NULL) or
1887 * generates a software time stamp (otherwise), then queues the clone
1888 * to the error queue of the socket. Errors are silently ignored.
1890 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1891 struct skb_shared_hwtstamps *hwtstamps);
1893 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1894 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1896 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1898 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1902 * skb_checksum_complete - Calculate checksum of an entire packet
1903 * @skb: packet to process
1905 * This function calculates the checksum over the entire packet plus
1906 * the value of skb->csum. The latter can be used to supply the
1907 * checksum of a pseudo header as used by TCP/UDP. It returns the
1910 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1911 * this function can be used to verify that checksum on received
1912 * packets. In that case the function should return zero if the
1913 * checksum is correct. In particular, this function will return zero
1914 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1915 * hardware has already verified the correctness of the checksum.
1917 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1919 return skb_csum_unnecessary(skb) ?
1920 0 : __skb_checksum_complete(skb);
1923 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1924 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1925 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1927 if (nfct && atomic_dec_and_test(&nfct->use))
1928 nf_conntrack_destroy(nfct);
1930 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1933 atomic_inc(&nfct->use);
1935 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1938 atomic_inc(&skb->users);
1940 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1946 #ifdef CONFIG_BRIDGE_NETFILTER
1947 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1949 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1952 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1955 atomic_inc(&nf_bridge->use);
1957 #endif /* CONFIG_BRIDGE_NETFILTER */
1958 static inline void nf_reset(struct sk_buff *skb)
1960 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1961 nf_conntrack_put(skb->nfct);
1963 nf_conntrack_put_reasm(skb->nfct_reasm);
1964 skb->nfct_reasm = NULL;
1966 #ifdef CONFIG_BRIDGE_NETFILTER
1967 nf_bridge_put(skb->nf_bridge);
1968 skb->nf_bridge = NULL;
1972 /* Note: This doesn't put any conntrack and bridge info in dst. */
1973 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1975 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1976 dst->nfct = src->nfct;
1977 nf_conntrack_get(src->nfct);
1978 dst->nfctinfo = src->nfctinfo;
1979 dst->nfct_reasm = src->nfct_reasm;
1980 nf_conntrack_get_reasm(src->nfct_reasm);
1982 #ifdef CONFIG_BRIDGE_NETFILTER
1983 dst->nf_bridge = src->nf_bridge;
1984 nf_bridge_get(src->nf_bridge);
1988 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1990 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1991 nf_conntrack_put(dst->nfct);
1992 nf_conntrack_put_reasm(dst->nfct_reasm);
1994 #ifdef CONFIG_BRIDGE_NETFILTER
1995 nf_bridge_put(dst->nf_bridge);
1997 __nf_copy(dst, src);
2000 #ifdef CONFIG_NETWORK_SECMARK
2001 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2003 to->secmark = from->secmark;
2006 static inline void skb_init_secmark(struct sk_buff *skb)
2011 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2014 static inline void skb_init_secmark(struct sk_buff *skb)
2018 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2020 skb->queue_mapping = queue_mapping;
2023 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2025 return skb->queue_mapping;
2028 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2030 to->queue_mapping = from->queue_mapping;
2033 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2035 skb->queue_mapping = rx_queue + 1;
2038 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2040 return skb->queue_mapping - 1;
2043 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2045 return (skb->queue_mapping != 0);
2048 extern u16 skb_tx_hash(const struct net_device *dev,
2049 const struct sk_buff *skb);
2052 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2057 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2063 static inline int skb_is_gso(const struct sk_buff *skb)
2065 return skb_shinfo(skb)->gso_size;
2068 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2070 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2073 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2075 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2077 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2078 * wanted then gso_type will be set. */
2079 struct skb_shared_info *shinfo = skb_shinfo(skb);
2080 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2081 __skb_warn_lro_forwarding(skb);
2087 static inline void skb_forward_csum(struct sk_buff *skb)
2089 /* Unfortunately we don't support this one. Any brave souls? */
2090 if (skb->ip_summed == CHECKSUM_COMPLETE)
2091 skb->ip_summed = CHECKSUM_NONE;
2094 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2095 #endif /* __KERNEL__ */
2096 #endif /* _LINUX_SKBUFF_H */