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 /* Don't change this without changing skb_csum_unnecessary! */
33 #define CHECKSUM_NONE 0
34 #define CHECKSUM_UNNECESSARY 1
35 #define CHECKSUM_COMPLETE 2
36 #define CHECKSUM_PARTIAL 3
38 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
39 ~(SMP_CACHE_BYTES - 1))
40 #define SKB_WITH_OVERHEAD(X) \
41 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
42 #define SKB_MAX_ORDER(X, ORDER) \
43 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
44 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
45 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
47 /* A. Checksumming of received packets by device.
49 * NONE: device failed to checksum this packet.
50 * skb->csum is undefined.
52 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
53 * skb->csum is undefined.
54 * It is bad option, but, unfortunately, many of vendors do this.
55 * Apparently with secret goal to sell you new device, when you
56 * will add new protocol to your host. F.e. IPv6. 8)
58 * COMPLETE: the most generic way. Device supplied checksum of _all_
59 * the packet as seen by netif_rx in skb->csum.
60 * NOTE: Even if device supports only some protocols, but
61 * is able to produce some skb->csum, it MUST use COMPLETE,
64 * PARTIAL: identical to the case for output below. This may occur
65 * on a packet received directly from another Linux OS, e.g.,
66 * a virtualised Linux kernel on the same host. The packet can
67 * be treated in the same way as UNNECESSARY except that on
68 * output (i.e., forwarding) the checksum must be filled in
69 * by the OS or the hardware.
71 * B. Checksumming on output.
73 * NONE: skb is checksummed by protocol or csum is not required.
75 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
76 * from skb->csum_start to the end and to record the checksum
77 * at skb->csum_start + skb->csum_offset.
79 * Device must show its capabilities in dev->features, set
80 * at device setup time.
81 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
83 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
84 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
85 * TCP/UDP over IPv4. Sigh. Vendors like this
86 * way by an unknown reason. Though, see comment above
87 * about CHECKSUM_UNNECESSARY. 8)
88 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
90 * Any questions? No questions, good. --ANK
95 struct pipe_inode_info;
97 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
103 #ifdef CONFIG_BRIDGE_NETFILTER
104 struct nf_bridge_info {
106 struct net_device *physindev;
107 struct net_device *physoutdev;
109 unsigned long data[32 / sizeof(unsigned long)];
113 struct sk_buff_head {
114 /* These two members must be first. */
115 struct sk_buff *next;
116 struct sk_buff *prev;
124 /* To allow 64K frame to be packed as single skb without frag_list */
125 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
127 typedef struct skb_frag_struct skb_frag_t;
129 struct skb_frag_struct {
135 #define HAVE_HW_TIME_STAMP
138 * struct skb_shared_hwtstamps - hardware time stamps
139 * @hwtstamp: hardware time stamp transformed into duration
140 * since arbitrary point in time
141 * @syststamp: hwtstamp transformed to system time base
143 * Software time stamps generated by ktime_get_real() are stored in
144 * skb->tstamp. The relation between the different kinds of time
145 * stamps is as follows:
147 * syststamp and tstamp can be compared against each other in
148 * arbitrary combinations. The accuracy of a
149 * syststamp/tstamp/"syststamp from other device" comparison is
150 * limited by the accuracy of the transformation into system time
151 * base. This depends on the device driver and its underlying
154 * hwtstamps can only be compared against other hwtstamps from
157 * This structure is attached to packets as part of the
158 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
160 struct skb_shared_hwtstamps {
166 * struct skb_shared_tx - instructions for time stamping of outgoing packets
167 * @hardware: generate hardware time stamp
168 * @software: generate software time stamp
169 * @in_progress: device driver is going to provide
170 * hardware time stamp
171 * @flags: all shared_tx flags
173 * These flags are attached to packets as part of the
174 * &skb_shared_info. Use skb_tx() to get a pointer.
176 union skb_shared_tx {
185 /* This data is invariant across clones and lives at
186 * the end of the header data, ie. at skb->end.
188 struct skb_shared_info {
190 unsigned short nr_frags;
191 unsigned short gso_size;
192 /* Warning: this field is not always filled in (UFO)! */
193 unsigned short gso_segs;
194 unsigned short gso_type;
196 union skb_shared_tx tx_flags;
197 #ifdef CONFIG_HAS_DMA
198 unsigned int num_dma_maps;
200 struct sk_buff *frag_list;
201 struct skb_shared_hwtstamps hwtstamps;
202 skb_frag_t frags[MAX_SKB_FRAGS];
203 #ifdef CONFIG_HAS_DMA
204 dma_addr_t dma_maps[MAX_SKB_FRAGS + 1];
206 /* Intermediate layers must ensure that destructor_arg
207 * remains valid until skb destructor */
208 void * destructor_arg;
211 /* We divide dataref into two halves. The higher 16 bits hold references
212 * to the payload part of skb->data. The lower 16 bits hold references to
213 * the entire skb->data. A clone of a headerless skb holds the length of
214 * the header in skb->hdr_len.
216 * All users must obey the rule that the skb->data reference count must be
217 * greater than or equal to the payload reference count.
219 * Holding a reference to the payload part means that the user does not
220 * care about modifications to the header part of skb->data.
222 #define SKB_DATAREF_SHIFT 16
223 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
227 SKB_FCLONE_UNAVAILABLE,
233 SKB_GSO_TCPV4 = 1 << 0,
234 SKB_GSO_UDP = 1 << 1,
236 /* This indicates the skb is from an untrusted source. */
237 SKB_GSO_DODGY = 1 << 2,
239 /* This indicates the tcp segment has CWR set. */
240 SKB_GSO_TCP_ECN = 1 << 3,
242 SKB_GSO_TCPV6 = 1 << 4,
244 SKB_GSO_FCOE = 1 << 5,
247 #if BITS_PER_LONG > 32
248 #define NET_SKBUFF_DATA_USES_OFFSET 1
251 #ifdef NET_SKBUFF_DATA_USES_OFFSET
252 typedef unsigned int sk_buff_data_t;
254 typedef unsigned char *sk_buff_data_t;
258 * struct sk_buff - socket buffer
259 * @next: Next buffer in list
260 * @prev: Previous buffer in list
261 * @sk: Socket we are owned by
262 * @tstamp: Time we arrived
263 * @dev: Device we arrived on/are leaving by
264 * @transport_header: Transport layer header
265 * @network_header: Network layer header
266 * @mac_header: Link layer header
267 * @dst: destination entry
268 * @sp: the security path, used for xfrm
269 * @cb: Control buffer. Free for use by every layer. Put private vars here
270 * @len: Length of actual data
271 * @data_len: Data length
272 * @mac_len: Length of link layer header
273 * @hdr_len: writable header length of cloned skb
274 * @csum: Checksum (must include start/offset pair)
275 * @csum_start: Offset from skb->head where checksumming should start
276 * @csum_offset: Offset from csum_start where checksum should be stored
277 * @local_df: allow local fragmentation
278 * @cloned: Head may be cloned (check refcnt to be sure)
279 * @nohdr: Payload reference only, must not modify header
280 * @pkt_type: Packet class
281 * @fclone: skbuff clone status
282 * @ip_summed: Driver fed us an IP checksum
283 * @priority: Packet queueing priority
284 * @users: User count - see {datagram,tcp}.c
285 * @protocol: Packet protocol from driver
286 * @truesize: Buffer size
287 * @head: Head of buffer
288 * @data: Data head pointer
289 * @tail: Tail pointer
291 * @destructor: Destruct function
292 * @mark: Generic packet mark
293 * @nfct: Associated connection, if any
294 * @ipvs_property: skbuff is owned by ipvs
295 * @peeked: this packet has been seen already, so stats have been
296 * done for it, don't do them again
297 * @nf_trace: netfilter packet trace flag
298 * @nfctinfo: Relationship of this skb to the connection
299 * @nfct_reasm: netfilter conntrack re-assembly pointer
300 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
301 * @iif: ifindex of device we arrived on
302 * @queue_mapping: Queue mapping for multiqueue devices
303 * @tc_index: Traffic control index
304 * @tc_verd: traffic control verdict
305 * @ndisc_nodetype: router type (from link layer)
306 * @do_not_encrypt: set to prevent encryption of this frame
307 * @requeue: set to indicate that the wireless core should attempt
308 * a software retry on this frame if we failed to
309 * receive an ACK for it
310 * @dma_cookie: a cookie to one of several possible DMA operations
311 * done by skb DMA functions
312 * @secmark: security marking
313 * @vlan_tci: vlan tag control information
317 /* These two members must be first. */
318 struct sk_buff *next;
319 struct sk_buff *prev;
323 struct net_device *dev;
326 struct dst_entry *dst;
327 struct rtable *rtable;
333 * This is the control buffer. It is free to use for every
334 * layer. Please put your private variables there. If you
335 * want to keep them across layers you have to do a skb_clone()
336 * first. This is owned by whoever has the skb queued ATM.
364 void (*destructor)(struct sk_buff *skb);
365 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
366 struct nf_conntrack *nfct;
367 struct sk_buff *nfct_reasm;
369 #ifdef CONFIG_BRIDGE_NETFILTER
370 struct nf_bridge_info *nf_bridge;
375 #ifdef CONFIG_NET_SCHED
376 __u16 tc_index; /* traffic control index */
377 #ifdef CONFIG_NET_CLS_ACT
378 __u16 tc_verd; /* traffic control verdict */
381 #ifdef CONFIG_IPV6_NDISC_NODETYPE
382 __u8 ndisc_nodetype:2;
384 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
385 __u8 do_not_encrypt:1;
388 /* 0/13/14 bit hole */
390 #ifdef CONFIG_NET_DMA
391 dma_cookie_t dma_cookie;
393 #ifdef CONFIG_NETWORK_SECMARK
401 sk_buff_data_t transport_header;
402 sk_buff_data_t network_header;
403 sk_buff_data_t mac_header;
404 /* These elements must be at the end, see alloc_skb() for details. */
409 unsigned int truesize;
415 * Handling routines are only of interest to the kernel
417 #include <linux/slab.h>
419 #include <asm/system.h>
421 #ifdef CONFIG_HAS_DMA
422 #include <linux/dma-mapping.h>
423 extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
424 enum dma_data_direction dir);
425 extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
426 enum dma_data_direction dir);
429 extern void kfree_skb(struct sk_buff *skb);
430 extern void consume_skb(struct sk_buff *skb);
431 extern void __kfree_skb(struct sk_buff *skb);
432 extern struct sk_buff *__alloc_skb(unsigned int size,
433 gfp_t priority, int fclone, int node);
434 static inline struct sk_buff *alloc_skb(unsigned int size,
437 return __alloc_skb(size, priority, 0, -1);
440 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
443 return __alloc_skb(size, priority, 1, -1);
446 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
448 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
449 extern struct sk_buff *skb_clone(struct sk_buff *skb,
451 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
453 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
455 extern int pskb_expand_head(struct sk_buff *skb,
456 int nhead, int ntail,
458 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
459 unsigned int headroom);
460 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
461 int newheadroom, int newtailroom,
463 extern int skb_to_sgvec(struct sk_buff *skb,
464 struct scatterlist *sg, int offset,
466 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
467 struct sk_buff **trailer);
468 extern int skb_pad(struct sk_buff *skb, int pad);
469 #define dev_kfree_skb(a) consume_skb(a)
470 #define dev_consume_skb(a) kfree_skb_clean(a)
471 extern void skb_over_panic(struct sk_buff *skb, int len,
473 extern void skb_under_panic(struct sk_buff *skb, int len,
476 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
477 int getfrag(void *from, char *to, int offset,
478 int len,int odd, struct sk_buff *skb),
479 void *from, int length);
486 __u32 stepped_offset;
487 struct sk_buff *root_skb;
488 struct sk_buff *cur_skb;
492 extern void skb_prepare_seq_read(struct sk_buff *skb,
493 unsigned int from, unsigned int to,
494 struct skb_seq_state *st);
495 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
496 struct skb_seq_state *st);
497 extern void skb_abort_seq_read(struct skb_seq_state *st);
499 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
500 unsigned int to, struct ts_config *config,
501 struct ts_state *state);
503 #ifdef NET_SKBUFF_DATA_USES_OFFSET
504 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
506 return skb->head + skb->end;
509 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
516 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
518 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
520 return &skb_shinfo(skb)->hwtstamps;
523 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
525 return &skb_shinfo(skb)->tx_flags;
529 * skb_queue_empty - check if a queue is empty
532 * Returns true if the queue is empty, false otherwise.
534 static inline int skb_queue_empty(const struct sk_buff_head *list)
536 return list->next == (struct sk_buff *)list;
540 * skb_queue_is_last - check if skb is the last entry in the queue
544 * Returns true if @skb is the last buffer on the list.
546 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
547 const struct sk_buff *skb)
549 return (skb->next == (struct sk_buff *) list);
553 * skb_queue_is_first - check if skb is the first entry in the queue
557 * Returns true if @skb is the first buffer on the list.
559 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
560 const struct sk_buff *skb)
562 return (skb->prev == (struct sk_buff *) list);
566 * skb_queue_next - return the next packet in the queue
568 * @skb: current buffer
570 * Return the next packet in @list after @skb. It is only valid to
571 * call this if skb_queue_is_last() evaluates to false.
573 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
574 const struct sk_buff *skb)
576 /* This BUG_ON may seem severe, but if we just return then we
577 * are going to dereference garbage.
579 BUG_ON(skb_queue_is_last(list, skb));
584 * skb_queue_prev - return the prev packet in the queue
586 * @skb: current buffer
588 * Return the prev packet in @list before @skb. It is only valid to
589 * call this if skb_queue_is_first() evaluates to false.
591 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
592 const struct sk_buff *skb)
594 /* This BUG_ON may seem severe, but if we just return then we
595 * are going to dereference garbage.
597 BUG_ON(skb_queue_is_first(list, skb));
602 * skb_get - reference buffer
603 * @skb: buffer to reference
605 * Makes another reference to a socket buffer and returns a pointer
608 static inline struct sk_buff *skb_get(struct sk_buff *skb)
610 atomic_inc(&skb->users);
615 * If users == 1, we are the only owner and are can avoid redundant
620 * skb_cloned - is the buffer a clone
621 * @skb: buffer to check
623 * Returns true if the buffer was generated with skb_clone() and is
624 * one of multiple shared copies of the buffer. Cloned buffers are
625 * shared data so must not be written to under normal circumstances.
627 static inline int skb_cloned(const struct sk_buff *skb)
629 return skb->cloned &&
630 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
634 * skb_header_cloned - is the header a clone
635 * @skb: buffer to check
637 * Returns true if modifying the header part of the buffer requires
638 * the data to be copied.
640 static inline int skb_header_cloned(const struct sk_buff *skb)
647 dataref = atomic_read(&skb_shinfo(skb)->dataref);
648 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
653 * skb_header_release - release reference to header
654 * @skb: buffer to operate on
656 * Drop a reference to the header part of the buffer. This is done
657 * by acquiring a payload reference. You must not read from the header
658 * part of skb->data after this.
660 static inline void skb_header_release(struct sk_buff *skb)
664 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
668 * skb_shared - is the buffer shared
669 * @skb: buffer to check
671 * Returns true if more than one person has a reference to this
674 static inline int skb_shared(const struct sk_buff *skb)
676 return atomic_read(&skb->users) != 1;
680 * skb_share_check - check if buffer is shared and if so clone it
681 * @skb: buffer to check
682 * @pri: priority for memory allocation
684 * If the buffer is shared the buffer is cloned and the old copy
685 * drops a reference. A new clone with a single reference is returned.
686 * If the buffer is not shared the original buffer is returned. When
687 * being called from interrupt status or with spinlocks held pri must
690 * NULL is returned on a memory allocation failure.
692 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
695 might_sleep_if(pri & __GFP_WAIT);
696 if (skb_shared(skb)) {
697 struct sk_buff *nskb = skb_clone(skb, pri);
705 * Copy shared buffers into a new sk_buff. We effectively do COW on
706 * packets to handle cases where we have a local reader and forward
707 * and a couple of other messy ones. The normal one is tcpdumping
708 * a packet thats being forwarded.
712 * skb_unshare - make a copy of a shared buffer
713 * @skb: buffer to check
714 * @pri: priority for memory allocation
716 * If the socket buffer is a clone then this function creates a new
717 * copy of the data, drops a reference count on the old copy and returns
718 * the new copy with the reference count at 1. If the buffer is not a clone
719 * the original buffer is returned. When called with a spinlock held or
720 * from interrupt state @pri must be %GFP_ATOMIC
722 * %NULL is returned on a memory allocation failure.
724 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
727 might_sleep_if(pri & __GFP_WAIT);
728 if (skb_cloned(skb)) {
729 struct sk_buff *nskb = skb_copy(skb, pri);
730 kfree_skb(skb); /* Free our shared copy */
738 * @list_: list to peek at
740 * Peek an &sk_buff. Unlike most other operations you _MUST_
741 * be careful with this one. A peek leaves the buffer on the
742 * list and someone else may run off with it. You must hold
743 * the appropriate locks or have a private queue to do this.
745 * Returns %NULL for an empty list or a pointer to the head element.
746 * The reference count is not incremented and the reference is therefore
747 * volatile. Use with caution.
749 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
751 struct sk_buff *list = ((struct sk_buff *)list_)->next;
752 if (list == (struct sk_buff *)list_)
759 * @list_: list to peek at
761 * Peek an &sk_buff. Unlike most other operations you _MUST_
762 * be careful with this one. A peek leaves the buffer on the
763 * list and someone else may run off with it. You must hold
764 * the appropriate locks or have a private queue to do this.
766 * Returns %NULL for an empty list or a pointer to the tail element.
767 * The reference count is not incremented and the reference is therefore
768 * volatile. Use with caution.
770 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
772 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
773 if (list == (struct sk_buff *)list_)
779 * skb_queue_len - get queue length
780 * @list_: list to measure
782 * Return the length of an &sk_buff queue.
784 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
790 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
791 * @list: queue to initialize
793 * This initializes only the list and queue length aspects of
794 * an sk_buff_head object. This allows to initialize the list
795 * aspects of an sk_buff_head without reinitializing things like
796 * the spinlock. It can also be used for on-stack sk_buff_head
797 * objects where the spinlock is known to not be used.
799 static inline void __skb_queue_head_init(struct sk_buff_head *list)
801 list->prev = list->next = (struct sk_buff *)list;
806 * This function creates a split out lock class for each invocation;
807 * this is needed for now since a whole lot of users of the skb-queue
808 * infrastructure in drivers have different locking usage (in hardirq)
809 * than the networking core (in softirq only). In the long run either the
810 * network layer or drivers should need annotation to consolidate the
811 * main types of usage into 3 classes.
813 static inline void skb_queue_head_init(struct sk_buff_head *list)
815 spin_lock_init(&list->lock);
816 __skb_queue_head_init(list);
819 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
820 struct lock_class_key *class)
822 skb_queue_head_init(list);
823 lockdep_set_class(&list->lock, class);
827 * Insert an sk_buff on a list.
829 * The "__skb_xxxx()" functions are the non-atomic ones that
830 * can only be called with interrupts disabled.
832 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
833 static inline void __skb_insert(struct sk_buff *newsk,
834 struct sk_buff *prev, struct sk_buff *next,
835 struct sk_buff_head *list)
839 next->prev = prev->next = newsk;
843 static inline void __skb_queue_splice(const struct sk_buff_head *list,
844 struct sk_buff *prev,
845 struct sk_buff *next)
847 struct sk_buff *first = list->next;
848 struct sk_buff *last = list->prev;
858 * skb_queue_splice - join two skb lists, this is designed for stacks
859 * @list: the new list to add
860 * @head: the place to add it in the first list
862 static inline void skb_queue_splice(const struct sk_buff_head *list,
863 struct sk_buff_head *head)
865 if (!skb_queue_empty(list)) {
866 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
867 head->qlen += list->qlen;
872 * skb_queue_splice - join two skb lists and reinitialise the emptied list
873 * @list: the new list to add
874 * @head: the place to add it in the first list
876 * The list at @list is reinitialised
878 static inline void skb_queue_splice_init(struct sk_buff_head *list,
879 struct sk_buff_head *head)
881 if (!skb_queue_empty(list)) {
882 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
883 head->qlen += list->qlen;
884 __skb_queue_head_init(list);
889 * skb_queue_splice_tail - join two skb lists, each list being a queue
890 * @list: the new list to add
891 * @head: the place to add it in the first list
893 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
894 struct sk_buff_head *head)
896 if (!skb_queue_empty(list)) {
897 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
898 head->qlen += list->qlen;
903 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
904 * @list: the new list to add
905 * @head: the place to add it in the first list
907 * Each of the lists is a queue.
908 * The list at @list is reinitialised
910 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
911 struct sk_buff_head *head)
913 if (!skb_queue_empty(list)) {
914 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
915 head->qlen += list->qlen;
916 __skb_queue_head_init(list);
921 * __skb_queue_after - queue a buffer at the list head
923 * @prev: place after this buffer
924 * @newsk: buffer to queue
926 * Queue a buffer int the middle of a list. This function takes no locks
927 * and you must therefore hold required locks before calling it.
929 * A buffer cannot be placed on two lists at the same time.
931 static inline void __skb_queue_after(struct sk_buff_head *list,
932 struct sk_buff *prev,
933 struct sk_buff *newsk)
935 __skb_insert(newsk, prev, prev->next, list);
938 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
939 struct sk_buff_head *list);
941 static inline void __skb_queue_before(struct sk_buff_head *list,
942 struct sk_buff *next,
943 struct sk_buff *newsk)
945 __skb_insert(newsk, next->prev, next, list);
949 * __skb_queue_head - queue a buffer at the list head
951 * @newsk: buffer to queue
953 * Queue a buffer at the start of a list. This function takes no locks
954 * and you must therefore hold required locks before calling it.
956 * A buffer cannot be placed on two lists at the same time.
958 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
959 static inline void __skb_queue_head(struct sk_buff_head *list,
960 struct sk_buff *newsk)
962 __skb_queue_after(list, (struct sk_buff *)list, newsk);
966 * __skb_queue_tail - queue a buffer at the list tail
968 * @newsk: buffer to queue
970 * Queue a buffer at the end of a list. This function takes no locks
971 * and you must therefore hold required locks before calling it.
973 * A buffer cannot be placed on two lists at the same time.
975 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
976 static inline void __skb_queue_tail(struct sk_buff_head *list,
977 struct sk_buff *newsk)
979 __skb_queue_before(list, (struct sk_buff *)list, newsk);
983 * remove sk_buff from list. _Must_ be called atomically, and with
986 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
987 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
989 struct sk_buff *next, *prev;
994 skb->next = skb->prev = NULL;
1000 * __skb_dequeue - remove from the head of the queue
1001 * @list: list to dequeue from
1003 * Remove the head of the list. This function does not take any locks
1004 * so must be used with appropriate locks held only. The head item is
1005 * returned or %NULL if the list is empty.
1007 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1008 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1010 struct sk_buff *skb = skb_peek(list);
1012 __skb_unlink(skb, list);
1017 * __skb_dequeue_tail - remove from the tail of the queue
1018 * @list: list to dequeue from
1020 * Remove the tail of the list. This function does not take any locks
1021 * so must be used with appropriate locks held only. The tail item is
1022 * returned or %NULL if the list is empty.
1024 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1025 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1027 struct sk_buff *skb = skb_peek_tail(list);
1029 __skb_unlink(skb, list);
1034 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1036 return skb->data_len;
1039 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1041 return skb->len - skb->data_len;
1044 static inline int skb_pagelen(const struct sk_buff *skb)
1048 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1049 len += skb_shinfo(skb)->frags[i].size;
1050 return len + skb_headlen(skb);
1053 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1054 struct page *page, int off, int size)
1056 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1059 frag->page_offset = off;
1061 skb_shinfo(skb)->nr_frags = i + 1;
1064 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1067 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1068 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1069 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1071 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1072 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1074 return skb->head + skb->tail;
1077 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1079 skb->tail = skb->data - skb->head;
1082 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1084 skb_reset_tail_pointer(skb);
1085 skb->tail += offset;
1087 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1088 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1093 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1095 skb->tail = skb->data;
1098 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1100 skb->tail = skb->data + offset;
1103 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1106 * Add data to an sk_buff
1108 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1109 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1111 unsigned char *tmp = skb_tail_pointer(skb);
1112 SKB_LINEAR_ASSERT(skb);
1118 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1119 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1126 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1127 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1130 BUG_ON(skb->len < skb->data_len);
1131 return skb->data += len;
1134 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1136 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1138 if (len > skb_headlen(skb) &&
1139 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1142 return skb->data += len;
1145 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1147 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1150 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1152 if (likely(len <= skb_headlen(skb)))
1154 if (unlikely(len > skb->len))
1156 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1160 * skb_headroom - bytes at buffer head
1161 * @skb: buffer to check
1163 * Return the number of bytes of free space at the head of an &sk_buff.
1165 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1167 return skb->data - skb->head;
1171 * skb_tailroom - bytes at buffer end
1172 * @skb: buffer to check
1174 * Return the number of bytes of free space at the tail of an sk_buff
1176 static inline int skb_tailroom(const struct sk_buff *skb)
1178 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1182 * skb_reserve - adjust headroom
1183 * @skb: buffer to alter
1184 * @len: bytes to move
1186 * Increase the headroom of an empty &sk_buff by reducing the tail
1187 * room. This is only allowed for an empty buffer.
1189 static inline void skb_reserve(struct sk_buff *skb, int len)
1195 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1196 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1198 return skb->head + skb->transport_header;
1201 static inline void skb_reset_transport_header(struct sk_buff *skb)
1203 skb->transport_header = skb->data - skb->head;
1206 static inline void skb_set_transport_header(struct sk_buff *skb,
1209 skb_reset_transport_header(skb);
1210 skb->transport_header += offset;
1213 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1215 return skb->head + skb->network_header;
1218 static inline void skb_reset_network_header(struct sk_buff *skb)
1220 skb->network_header = skb->data - skb->head;
1223 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1225 skb_reset_network_header(skb);
1226 skb->network_header += offset;
1229 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1231 return skb->head + skb->mac_header;
1234 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1236 return skb->mac_header != ~0U;
1239 static inline void skb_reset_mac_header(struct sk_buff *skb)
1241 skb->mac_header = skb->data - skb->head;
1244 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1246 skb_reset_mac_header(skb);
1247 skb->mac_header += offset;
1250 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1252 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1254 return skb->transport_header;
1257 static inline void skb_reset_transport_header(struct sk_buff *skb)
1259 skb->transport_header = skb->data;
1262 static inline void skb_set_transport_header(struct sk_buff *skb,
1265 skb->transport_header = skb->data + offset;
1268 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1270 return skb->network_header;
1273 static inline void skb_reset_network_header(struct sk_buff *skb)
1275 skb->network_header = skb->data;
1278 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1280 skb->network_header = skb->data + offset;
1283 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1285 return skb->mac_header;
1288 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1290 return skb->mac_header != NULL;
1293 static inline void skb_reset_mac_header(struct sk_buff *skb)
1295 skb->mac_header = skb->data;
1298 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1300 skb->mac_header = skb->data + offset;
1302 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1304 static inline int skb_transport_offset(const struct sk_buff *skb)
1306 return skb_transport_header(skb) - skb->data;
1309 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1311 return skb->transport_header - skb->network_header;
1314 static inline int skb_network_offset(const struct sk_buff *skb)
1316 return skb_network_header(skb) - skb->data;
1320 * CPUs often take a performance hit when accessing unaligned memory
1321 * locations. The actual performance hit varies, it can be small if the
1322 * hardware handles it or large if we have to take an exception and fix it
1325 * Since an ethernet header is 14 bytes network drivers often end up with
1326 * the IP header at an unaligned offset. The IP header can be aligned by
1327 * shifting the start of the packet by 2 bytes. Drivers should do this
1330 * skb_reserve(NET_IP_ALIGN);
1332 * The downside to this alignment of the IP header is that the DMA is now
1333 * unaligned. On some architectures the cost of an unaligned DMA is high
1334 * and this cost outweighs the gains made by aligning the IP header.
1336 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1339 #ifndef NET_IP_ALIGN
1340 #define NET_IP_ALIGN 2
1344 * The networking layer reserves some headroom in skb data (via
1345 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1346 * the header has to grow. In the default case, if the header has to grow
1347 * 32 bytes or less we avoid the reallocation.
1349 * Unfortunately this headroom changes the DMA alignment of the resulting
1350 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1351 * on some architectures. An architecture can override this value,
1352 * perhaps setting it to a cacheline in size (since that will maintain
1353 * cacheline alignment of the DMA). It must be a power of 2.
1355 * Various parts of the networking layer expect at least 32 bytes of
1356 * headroom, you should not reduce this.
1359 #define NET_SKB_PAD 32
1362 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1364 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1366 if (unlikely(skb->data_len)) {
1371 skb_set_tail_pointer(skb, len);
1374 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1376 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1379 return ___pskb_trim(skb, len);
1380 __skb_trim(skb, len);
1384 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1386 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1390 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1391 * @skb: buffer to alter
1394 * This is identical to pskb_trim except that the caller knows that
1395 * the skb is not cloned so we should never get an error due to out-
1398 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1400 int err = pskb_trim(skb, len);
1405 * skb_orphan - orphan a buffer
1406 * @skb: buffer to orphan
1408 * If a buffer currently has an owner then we call the owner's
1409 * destructor function and make the @skb unowned. The buffer continues
1410 * to exist but is no longer charged to its former owner.
1412 static inline void skb_orphan(struct sk_buff *skb)
1414 if (skb->destructor)
1415 skb->destructor(skb);
1416 skb->destructor = NULL;
1421 * __skb_queue_purge - empty a list
1422 * @list: list to empty
1424 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1425 * the list and one reference dropped. This function does not take the
1426 * list lock and the caller must hold the relevant locks to use it.
1428 extern void skb_queue_purge(struct sk_buff_head *list);
1429 static inline void __skb_queue_purge(struct sk_buff_head *list)
1431 struct sk_buff *skb;
1432 while ((skb = __skb_dequeue(list)) != NULL)
1437 * __dev_alloc_skb - allocate an skbuff for receiving
1438 * @length: length to allocate
1439 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1441 * Allocate a new &sk_buff and assign it a usage count of one. The
1442 * buffer has unspecified headroom built in. Users should allocate
1443 * the headroom they think they need without accounting for the
1444 * built in space. The built in space is used for optimisations.
1446 * %NULL is returned if there is no free memory.
1448 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1451 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1453 skb_reserve(skb, NET_SKB_PAD);
1457 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1459 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1460 unsigned int length, gfp_t gfp_mask);
1463 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1464 * @dev: network device to receive on
1465 * @length: length to allocate
1467 * Allocate a new &sk_buff and assign it a usage count of one. The
1468 * buffer has unspecified headroom built in. Users should allocate
1469 * the headroom they think they need without accounting for the
1470 * built in space. The built in space is used for optimisations.
1472 * %NULL is returned if there is no free memory. Although this function
1473 * allocates memory it can be called from an interrupt.
1475 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1476 unsigned int length)
1478 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1481 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1484 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1485 * @dev: network device to receive on
1487 * Allocate a new page node local to the specified device.
1489 * %NULL is returned if there is no free memory.
1491 static inline struct page *netdev_alloc_page(struct net_device *dev)
1493 return __netdev_alloc_page(dev, GFP_ATOMIC);
1496 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1502 * skb_clone_writable - is the header of a clone writable
1503 * @skb: buffer to check
1504 * @len: length up to which to write
1506 * Returns true if modifying the header part of the cloned buffer
1507 * does not requires the data to be copied.
1509 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1511 return !skb_header_cloned(skb) &&
1512 skb_headroom(skb) + len <= skb->hdr_len;
1515 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1520 if (headroom < NET_SKB_PAD)
1521 headroom = NET_SKB_PAD;
1522 if (headroom > skb_headroom(skb))
1523 delta = headroom - skb_headroom(skb);
1525 if (delta || cloned)
1526 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1532 * skb_cow - copy header of skb when it is required
1533 * @skb: buffer to cow
1534 * @headroom: needed headroom
1536 * If the skb passed lacks sufficient headroom or its data part
1537 * is shared, data is reallocated. If reallocation fails, an error
1538 * is returned and original skb is not changed.
1540 * The result is skb with writable area skb->head...skb->tail
1541 * and at least @headroom of space at head.
1543 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1545 return __skb_cow(skb, headroom, skb_cloned(skb));
1549 * skb_cow_head - skb_cow but only making the head writable
1550 * @skb: buffer to cow
1551 * @headroom: needed headroom
1553 * This function is identical to skb_cow except that we replace the
1554 * skb_cloned check by skb_header_cloned. It should be used when
1555 * you only need to push on some header and do not need to modify
1558 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1560 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1564 * skb_padto - pad an skbuff up to a minimal size
1565 * @skb: buffer to pad
1566 * @len: minimal length
1568 * Pads up a buffer to ensure the trailing bytes exist and are
1569 * blanked. If the buffer already contains sufficient data it
1570 * is untouched. Otherwise it is extended. Returns zero on
1571 * success. The skb is freed on error.
1574 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1576 unsigned int size = skb->len;
1577 if (likely(size >= len))
1579 return skb_pad(skb, len - size);
1582 static inline int skb_add_data(struct sk_buff *skb,
1583 char __user *from, int copy)
1585 const int off = skb->len;
1587 if (skb->ip_summed == CHECKSUM_NONE) {
1589 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1592 skb->csum = csum_block_add(skb->csum, csum, off);
1595 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1598 __skb_trim(skb, off);
1602 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1603 struct page *page, int off)
1606 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1608 return page == frag->page &&
1609 off == frag->page_offset + frag->size;
1614 static inline int __skb_linearize(struct sk_buff *skb)
1616 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1620 * skb_linearize - convert paged skb to linear one
1621 * @skb: buffer to linarize
1623 * If there is no free memory -ENOMEM is returned, otherwise zero
1624 * is returned and the old skb data released.
1626 static inline int skb_linearize(struct sk_buff *skb)
1628 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1632 * skb_linearize_cow - make sure skb is linear and writable
1633 * @skb: buffer to process
1635 * If there is no free memory -ENOMEM is returned, otherwise zero
1636 * is returned and the old skb data released.
1638 static inline int skb_linearize_cow(struct sk_buff *skb)
1640 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1641 __skb_linearize(skb) : 0;
1645 * skb_postpull_rcsum - update checksum for received skb after pull
1646 * @skb: buffer to update
1647 * @start: start of data before pull
1648 * @len: length of data pulled
1650 * After doing a pull on a received packet, you need to call this to
1651 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1652 * CHECKSUM_NONE so that it can be recomputed from scratch.
1655 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1656 const void *start, unsigned int len)
1658 if (skb->ip_summed == CHECKSUM_COMPLETE)
1659 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1662 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1665 * pskb_trim_rcsum - trim received skb and update checksum
1666 * @skb: buffer to trim
1669 * This is exactly the same as pskb_trim except that it ensures the
1670 * checksum of received packets are still valid after the operation.
1673 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1675 if (likely(len >= skb->len))
1677 if (skb->ip_summed == CHECKSUM_COMPLETE)
1678 skb->ip_summed = CHECKSUM_NONE;
1679 return __pskb_trim(skb, len);
1682 #define skb_queue_walk(queue, skb) \
1683 for (skb = (queue)->next; \
1684 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1687 #define skb_queue_walk_safe(queue, skb, tmp) \
1688 for (skb = (queue)->next, tmp = skb->next; \
1689 skb != (struct sk_buff *)(queue); \
1690 skb = tmp, tmp = skb->next)
1692 #define skb_queue_walk_from(queue, skb) \
1693 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1696 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1697 for (tmp = skb->next; \
1698 skb != (struct sk_buff *)(queue); \
1699 skb = tmp, tmp = skb->next)
1701 #define skb_queue_reverse_walk(queue, skb) \
1702 for (skb = (queue)->prev; \
1703 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1707 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1708 int *peeked, int *err);
1709 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1710 int noblock, int *err);
1711 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1712 struct poll_table_struct *wait);
1713 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1714 int offset, struct iovec *to,
1716 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1719 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1721 const struct iovec *from,
1724 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
1726 const struct iovec *to,
1729 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1730 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1731 unsigned int flags);
1732 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1733 int len, __wsum csum);
1734 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1736 extern int skb_store_bits(struct sk_buff *skb, int offset,
1737 const void *from, int len);
1738 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1739 int offset, u8 *to, int len,
1741 extern int skb_splice_bits(struct sk_buff *skb,
1742 unsigned int offset,
1743 struct pipe_inode_info *pipe,
1745 unsigned int flags);
1746 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1747 extern void skb_split(struct sk_buff *skb,
1748 struct sk_buff *skb1, const u32 len);
1749 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1752 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1754 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1755 int len, void *buffer)
1757 int hlen = skb_headlen(skb);
1759 if (hlen - offset >= len)
1760 return skb->data + offset;
1762 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1768 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1770 const unsigned int len)
1772 memcpy(to, skb->data, len);
1775 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1776 const int offset, void *to,
1777 const unsigned int len)
1779 memcpy(to, skb->data + offset, len);
1782 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1784 const unsigned int len)
1786 memcpy(skb->data, from, len);
1789 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1792 const unsigned int len)
1794 memcpy(skb->data + offset, from, len);
1797 extern void skb_init(void);
1799 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1805 * skb_get_timestamp - get timestamp from a skb
1806 * @skb: skb to get stamp from
1807 * @stamp: pointer to struct timeval to store stamp in
1809 * Timestamps are stored in the skb as offsets to a base timestamp.
1810 * This function converts the offset back to a struct timeval and stores
1813 static inline void skb_get_timestamp(const struct sk_buff *skb,
1814 struct timeval *stamp)
1816 *stamp = ktime_to_timeval(skb->tstamp);
1819 static inline void skb_get_timestampns(const struct sk_buff *skb,
1820 struct timespec *stamp)
1822 *stamp = ktime_to_timespec(skb->tstamp);
1825 static inline void __net_timestamp(struct sk_buff *skb)
1827 skb->tstamp = ktime_get_real();
1830 static inline ktime_t net_timedelta(ktime_t t)
1832 return ktime_sub(ktime_get_real(), t);
1835 static inline ktime_t net_invalid_timestamp(void)
1837 return ktime_set(0, 0);
1841 * skb_tstamp_tx - queue clone of skb with send time stamps
1842 * @orig_skb: the original outgoing packet
1843 * @hwtstamps: hardware time stamps, may be NULL if not available
1845 * If the skb has a socket associated, then this function clones the
1846 * skb (thus sharing the actual data and optional structures), stores
1847 * the optional hardware time stamping information (if non NULL) or
1848 * generates a software time stamp (otherwise), then queues the clone
1849 * to the error queue of the socket. Errors are silently ignored.
1851 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1852 struct skb_shared_hwtstamps *hwtstamps);
1854 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1855 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1857 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1859 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1863 * skb_checksum_complete - Calculate checksum of an entire packet
1864 * @skb: packet to process
1866 * This function calculates the checksum over the entire packet plus
1867 * the value of skb->csum. The latter can be used to supply the
1868 * checksum of a pseudo header as used by TCP/UDP. It returns the
1871 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1872 * this function can be used to verify that checksum on received
1873 * packets. In that case the function should return zero if the
1874 * checksum is correct. In particular, this function will return zero
1875 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1876 * hardware has already verified the correctness of the checksum.
1878 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1880 return skb_csum_unnecessary(skb) ?
1881 0 : __skb_checksum_complete(skb);
1884 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1885 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1886 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1888 if (nfct && atomic_dec_and_test(&nfct->use))
1889 nf_conntrack_destroy(nfct);
1891 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1894 atomic_inc(&nfct->use);
1896 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1899 atomic_inc(&skb->users);
1901 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1907 #ifdef CONFIG_BRIDGE_NETFILTER
1908 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1910 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1913 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1916 atomic_inc(&nf_bridge->use);
1918 #endif /* CONFIG_BRIDGE_NETFILTER */
1919 static inline void nf_reset(struct sk_buff *skb)
1921 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1922 nf_conntrack_put(skb->nfct);
1924 nf_conntrack_put_reasm(skb->nfct_reasm);
1925 skb->nfct_reasm = NULL;
1927 #ifdef CONFIG_BRIDGE_NETFILTER
1928 nf_bridge_put(skb->nf_bridge);
1929 skb->nf_bridge = NULL;
1933 /* Note: This doesn't put any conntrack and bridge info in dst. */
1934 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1936 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1937 dst->nfct = src->nfct;
1938 nf_conntrack_get(src->nfct);
1939 dst->nfctinfo = src->nfctinfo;
1940 dst->nfct_reasm = src->nfct_reasm;
1941 nf_conntrack_get_reasm(src->nfct_reasm);
1943 #ifdef CONFIG_BRIDGE_NETFILTER
1944 dst->nf_bridge = src->nf_bridge;
1945 nf_bridge_get(src->nf_bridge);
1949 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1951 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1952 nf_conntrack_put(dst->nfct);
1953 nf_conntrack_put_reasm(dst->nfct_reasm);
1955 #ifdef CONFIG_BRIDGE_NETFILTER
1956 nf_bridge_put(dst->nf_bridge);
1958 __nf_copy(dst, src);
1961 #ifdef CONFIG_NETWORK_SECMARK
1962 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1964 to->secmark = from->secmark;
1967 static inline void skb_init_secmark(struct sk_buff *skb)
1972 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1975 static inline void skb_init_secmark(struct sk_buff *skb)
1979 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1981 skb->queue_mapping = queue_mapping;
1984 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
1986 return skb->queue_mapping;
1989 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1991 to->queue_mapping = from->queue_mapping;
1994 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
1996 skb->queue_mapping = rx_queue + 1;
1999 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2001 return skb->queue_mapping - 1;
2004 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2006 return (skb->queue_mapping != 0);
2009 extern u16 skb_tx_hash(const struct net_device *dev,
2010 const struct sk_buff *skb);
2013 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2018 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2024 static inline int skb_is_gso(const struct sk_buff *skb)
2026 return skb_shinfo(skb)->gso_size;
2029 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2031 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2034 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2036 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2038 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2039 * wanted then gso_type will be set. */
2040 struct skb_shared_info *shinfo = skb_shinfo(skb);
2041 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2042 __skb_warn_lro_forwarding(skb);
2048 static inline void skb_forward_csum(struct sk_buff *skb)
2050 /* Unfortunately we don't support this one. Any brave souls? */
2051 if (skb->ip_summed == CHECKSUM_COMPLETE)
2052 skb->ip_summed = CHECKSUM_NONE;
2055 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2056 #endif /* __KERNEL__ */
2057 #endif /* _LINUX_SKBUFF_H */