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 /* Warning: this field is not always filled in (UFO)! */
194 unsigned short gso_segs;
195 unsigned short gso_type;
197 union skb_shared_tx tx_flags;
198 #ifdef CONFIG_HAS_DMA
199 unsigned int num_dma_maps;
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 + 1];
209 /* We divide dataref into two halves. The higher 16 bits hold references
210 * to the payload part of skb->data. The lower 16 bits hold references to
211 * the entire skb->data. A clone of a headerless skb holds the length of
212 * the header in skb->hdr_len.
214 * All users must obey the rule that the skb->data reference count must be
215 * greater than or equal to the payload reference count.
217 * Holding a reference to the payload part means that the user does not
218 * care about modifications to the header part of skb->data.
220 #define SKB_DATAREF_SHIFT 16
221 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
225 SKB_FCLONE_UNAVAILABLE,
231 SKB_GSO_TCPV4 = 1 << 0,
232 SKB_GSO_UDP = 1 << 1,
234 /* This indicates the skb is from an untrusted source. */
235 SKB_GSO_DODGY = 1 << 2,
237 /* This indicates the tcp segment has CWR set. */
238 SKB_GSO_TCP_ECN = 1 << 3,
240 SKB_GSO_TCPV6 = 1 << 4,
242 SKB_GSO_FCOE = 1 << 5,
245 #if BITS_PER_LONG > 32
246 #define NET_SKBUFF_DATA_USES_OFFSET 1
249 #ifdef NET_SKBUFF_DATA_USES_OFFSET
250 typedef unsigned int sk_buff_data_t;
252 typedef unsigned char *sk_buff_data_t;
256 * struct sk_buff - socket buffer
257 * @next: Next buffer in list
258 * @prev: Previous buffer in list
259 * @sk: Socket we are owned by
260 * @tstamp: Time we arrived
261 * @dev: Device we arrived on/are leaving by
262 * @transport_header: Transport layer header
263 * @network_header: Network layer header
264 * @mac_header: Link layer header
265 * @dst: destination entry
266 * @sp: the security path, used for xfrm
267 * @cb: Control buffer. Free for use by every layer. Put private vars here
268 * @len: Length of actual data
269 * @data_len: Data length
270 * @mac_len: Length of link layer header
271 * @hdr_len: writable header length of cloned skb
272 * @csum: Checksum (must include start/offset pair)
273 * @csum_start: Offset from skb->head where checksumming should start
274 * @csum_offset: Offset from csum_start where checksum should be stored
275 * @local_df: allow local fragmentation
276 * @cloned: Head may be cloned (check refcnt to be sure)
277 * @nohdr: Payload reference only, must not modify header
278 * @pkt_type: Packet class
279 * @fclone: skbuff clone status
280 * @ip_summed: Driver fed us an IP checksum
281 * @priority: Packet queueing priority
282 * @users: User count - see {datagram,tcp}.c
283 * @protocol: Packet protocol from driver
284 * @truesize: Buffer size
285 * @head: Head of buffer
286 * @data: Data head pointer
287 * @tail: Tail pointer
289 * @destructor: Destruct function
290 * @mark: Generic packet mark
291 * @nfct: Associated connection, if any
292 * @ipvs_property: skbuff is owned by ipvs
293 * @peeked: this packet has been seen already, so stats have been
294 * done for it, don't do them again
295 * @nf_trace: netfilter packet trace flag
296 * @nfctinfo: Relationship of this skb to the connection
297 * @nfct_reasm: netfilter conntrack re-assembly pointer
298 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
299 * @iif: ifindex of device we arrived on
300 * @queue_mapping: Queue mapping for multiqueue devices
301 * @tc_index: Traffic control index
302 * @tc_verd: traffic control verdict
303 * @ndisc_nodetype: router type (from link layer)
304 * @do_not_encrypt: set to prevent encryption of this frame
305 * @requeue: set to indicate that the wireless core should attempt
306 * a software retry on this frame if we failed to
307 * receive an ACK for it
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;
321 struct net_device *dev;
324 struct dst_entry *dst;
325 struct rtable *rtable;
331 * This is the control buffer. It is free to use for every
332 * layer. Please put your private variables there. If you
333 * want to keep them across layers you have to do a skb_clone()
334 * first. This is owned by whoever has the skb queued ATM.
350 kmemcheck_bitfield_begin(flags1);
361 kmemcheck_bitfield_end(flags1);
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 */
382 kmemcheck_bitfield_begin(flags2);
383 #ifdef CONFIG_IPV6_NDISC_NODETYPE
384 __u8 ndisc_nodetype:2;
386 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
387 __u8 do_not_encrypt:1;
390 kmemcheck_bitfield_end(flags2);
392 /* 0/13/14 bit hole */
394 #ifdef CONFIG_NET_DMA
395 dma_cookie_t dma_cookie;
397 #ifdef CONFIG_NETWORK_SECMARK
405 sk_buff_data_t transport_header;
406 sk_buff_data_t network_header;
407 sk_buff_data_t mac_header;
408 /* These elements must be at the end, see alloc_skb() for details. */
413 unsigned int truesize;
419 * Handling routines are only of interest to the kernel
421 #include <linux/slab.h>
423 #include <asm/system.h>
425 #ifdef CONFIG_HAS_DMA
426 #include <linux/dma-mapping.h>
427 extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
428 enum dma_data_direction dir);
429 extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
430 enum dma_data_direction dir);
433 extern void kfree_skb(struct sk_buff *skb);
434 extern void consume_skb(struct sk_buff *skb);
435 extern void __kfree_skb(struct sk_buff *skb);
436 extern struct sk_buff *__alloc_skb(unsigned int size,
437 gfp_t priority, int fclone, int node);
438 static inline struct sk_buff *alloc_skb(unsigned int size,
441 return __alloc_skb(size, priority, 0, -1);
444 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
447 return __alloc_skb(size, priority, 1, -1);
450 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
452 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
453 extern struct sk_buff *skb_clone(struct sk_buff *skb,
455 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
457 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
459 extern int pskb_expand_head(struct sk_buff *skb,
460 int nhead, int ntail,
462 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
463 unsigned int headroom);
464 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
465 int newheadroom, int newtailroom,
467 extern int skb_to_sgvec(struct sk_buff *skb,
468 struct scatterlist *sg, int offset,
470 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
471 struct sk_buff **trailer);
472 extern int skb_pad(struct sk_buff *skb, int pad);
473 #define dev_kfree_skb(a) consume_skb(a)
474 #define dev_consume_skb(a) kfree_skb_clean(a)
475 extern void skb_over_panic(struct sk_buff *skb, int len,
477 extern void skb_under_panic(struct sk_buff *skb, int len,
480 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
481 int getfrag(void *from, char *to, int offset,
482 int len,int odd, struct sk_buff *skb),
483 void *from, int length);
490 __u32 stepped_offset;
491 struct sk_buff *root_skb;
492 struct sk_buff *cur_skb;
496 extern void skb_prepare_seq_read(struct sk_buff *skb,
497 unsigned int from, unsigned int to,
498 struct skb_seq_state *st);
499 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
500 struct skb_seq_state *st);
501 extern void skb_abort_seq_read(struct skb_seq_state *st);
503 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
504 unsigned int to, struct ts_config *config,
505 struct ts_state *state);
507 #ifdef NET_SKBUFF_DATA_USES_OFFSET
508 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
510 return skb->head + skb->end;
513 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
520 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
522 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
524 return &skb_shinfo(skb)->hwtstamps;
527 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
529 return &skb_shinfo(skb)->tx_flags;
533 * skb_queue_empty - check if a queue is empty
536 * Returns true if the queue is empty, false otherwise.
538 static inline int skb_queue_empty(const struct sk_buff_head *list)
540 return list->next == (struct sk_buff *)list;
544 * skb_queue_is_last - check if skb is the last entry in the queue
548 * Returns true if @skb is the last buffer on the list.
550 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
551 const struct sk_buff *skb)
553 return (skb->next == (struct sk_buff *) list);
557 * skb_queue_is_first - check if skb is the first entry in the queue
561 * Returns true if @skb is the first buffer on the list.
563 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
564 const struct sk_buff *skb)
566 return (skb->prev == (struct sk_buff *) list);
570 * skb_queue_next - return the next packet in the queue
572 * @skb: current buffer
574 * Return the next packet in @list after @skb. It is only valid to
575 * call this if skb_queue_is_last() evaluates to false.
577 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
578 const struct sk_buff *skb)
580 /* This BUG_ON may seem severe, but if we just return then we
581 * are going to dereference garbage.
583 BUG_ON(skb_queue_is_last(list, skb));
588 * skb_queue_prev - return the prev packet in the queue
590 * @skb: current buffer
592 * Return the prev packet in @list before @skb. It is only valid to
593 * call this if skb_queue_is_first() evaluates to false.
595 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
596 const struct sk_buff *skb)
598 /* This BUG_ON may seem severe, but if we just return then we
599 * are going to dereference garbage.
601 BUG_ON(skb_queue_is_first(list, skb));
606 * skb_get - reference buffer
607 * @skb: buffer to reference
609 * Makes another reference to a socket buffer and returns a pointer
612 static inline struct sk_buff *skb_get(struct sk_buff *skb)
614 atomic_inc(&skb->users);
619 * If users == 1, we are the only owner and are can avoid redundant
624 * skb_cloned - is the buffer a clone
625 * @skb: buffer to check
627 * Returns true if the buffer was generated with skb_clone() and is
628 * one of multiple shared copies of the buffer. Cloned buffers are
629 * shared data so must not be written to under normal circumstances.
631 static inline int skb_cloned(const struct sk_buff *skb)
633 return skb->cloned &&
634 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
638 * skb_header_cloned - is the header a clone
639 * @skb: buffer to check
641 * Returns true if modifying the header part of the buffer requires
642 * the data to be copied.
644 static inline int skb_header_cloned(const struct sk_buff *skb)
651 dataref = atomic_read(&skb_shinfo(skb)->dataref);
652 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
657 * skb_header_release - release reference to header
658 * @skb: buffer to operate on
660 * Drop a reference to the header part of the buffer. This is done
661 * by acquiring a payload reference. You must not read from the header
662 * part of skb->data after this.
664 static inline void skb_header_release(struct sk_buff *skb)
668 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
672 * skb_shared - is the buffer shared
673 * @skb: buffer to check
675 * Returns true if more than one person has a reference to this
678 static inline int skb_shared(const struct sk_buff *skb)
680 return atomic_read(&skb->users) != 1;
684 * skb_share_check - check if buffer is shared and if so clone it
685 * @skb: buffer to check
686 * @pri: priority for memory allocation
688 * If the buffer is shared the buffer is cloned and the old copy
689 * drops a reference. A new clone with a single reference is returned.
690 * If the buffer is not shared the original buffer is returned. When
691 * being called from interrupt status or with spinlocks held pri must
694 * NULL is returned on a memory allocation failure.
696 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
699 might_sleep_if(pri & __GFP_WAIT);
700 if (skb_shared(skb)) {
701 struct sk_buff *nskb = skb_clone(skb, pri);
709 * Copy shared buffers into a new sk_buff. We effectively do COW on
710 * packets to handle cases where we have a local reader and forward
711 * and a couple of other messy ones. The normal one is tcpdumping
712 * a packet thats being forwarded.
716 * skb_unshare - make a copy of a shared buffer
717 * @skb: buffer to check
718 * @pri: priority for memory allocation
720 * If the socket buffer is a clone then this function creates a new
721 * copy of the data, drops a reference count on the old copy and returns
722 * the new copy with the reference count at 1. If the buffer is not a clone
723 * the original buffer is returned. When called with a spinlock held or
724 * from interrupt state @pri must be %GFP_ATOMIC
726 * %NULL is returned on a memory allocation failure.
728 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
731 might_sleep_if(pri & __GFP_WAIT);
732 if (skb_cloned(skb)) {
733 struct sk_buff *nskb = skb_copy(skb, pri);
734 kfree_skb(skb); /* Free our shared copy */
742 * @list_: list to peek at
744 * Peek an &sk_buff. Unlike most other operations you _MUST_
745 * be careful with this one. A peek leaves the buffer on the
746 * list and someone else may run off with it. You must hold
747 * the appropriate locks or have a private queue to do this.
749 * Returns %NULL for an empty list or a pointer to the head element.
750 * The reference count is not incremented and the reference is therefore
751 * volatile. Use with caution.
753 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
755 struct sk_buff *list = ((struct sk_buff *)list_)->next;
756 if (list == (struct sk_buff *)list_)
763 * @list_: list to peek at
765 * Peek an &sk_buff. Unlike most other operations you _MUST_
766 * be careful with this one. A peek leaves the buffer on the
767 * list and someone else may run off with it. You must hold
768 * the appropriate locks or have a private queue to do this.
770 * Returns %NULL for an empty list or a pointer to the tail element.
771 * The reference count is not incremented and the reference is therefore
772 * volatile. Use with caution.
774 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
776 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
777 if (list == (struct sk_buff *)list_)
783 * skb_queue_len - get queue length
784 * @list_: list to measure
786 * Return the length of an &sk_buff queue.
788 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
794 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
795 * @list: queue to initialize
797 * This initializes only the list and queue length aspects of
798 * an sk_buff_head object. This allows to initialize the list
799 * aspects of an sk_buff_head without reinitializing things like
800 * the spinlock. It can also be used for on-stack sk_buff_head
801 * objects where the spinlock is known to not be used.
803 static inline void __skb_queue_head_init(struct sk_buff_head *list)
805 list->prev = list->next = (struct sk_buff *)list;
810 * This function creates a split out lock class for each invocation;
811 * this is needed for now since a whole lot of users of the skb-queue
812 * infrastructure in drivers have different locking usage (in hardirq)
813 * than the networking core (in softirq only). In the long run either the
814 * network layer or drivers should need annotation to consolidate the
815 * main types of usage into 3 classes.
817 static inline void skb_queue_head_init(struct sk_buff_head *list)
819 spin_lock_init(&list->lock);
820 __skb_queue_head_init(list);
823 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
824 struct lock_class_key *class)
826 skb_queue_head_init(list);
827 lockdep_set_class(&list->lock, class);
831 * Insert an sk_buff on a list.
833 * The "__skb_xxxx()" functions are the non-atomic ones that
834 * can only be called with interrupts disabled.
836 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
837 static inline void __skb_insert(struct sk_buff *newsk,
838 struct sk_buff *prev, struct sk_buff *next,
839 struct sk_buff_head *list)
843 next->prev = prev->next = newsk;
847 static inline void __skb_queue_splice(const struct sk_buff_head *list,
848 struct sk_buff *prev,
849 struct sk_buff *next)
851 struct sk_buff *first = list->next;
852 struct sk_buff *last = list->prev;
862 * skb_queue_splice - join two skb lists, this is designed for stacks
863 * @list: the new list to add
864 * @head: the place to add it in the first list
866 static inline void skb_queue_splice(const struct sk_buff_head *list,
867 struct sk_buff_head *head)
869 if (!skb_queue_empty(list)) {
870 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
871 head->qlen += list->qlen;
876 * skb_queue_splice - join two skb lists and reinitialise the emptied list
877 * @list: the new list to add
878 * @head: the place to add it in the first list
880 * The list at @list is reinitialised
882 static inline void skb_queue_splice_init(struct sk_buff_head *list,
883 struct sk_buff_head *head)
885 if (!skb_queue_empty(list)) {
886 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
887 head->qlen += list->qlen;
888 __skb_queue_head_init(list);
893 * skb_queue_splice_tail - join two skb lists, each list being a queue
894 * @list: the new list to add
895 * @head: the place to add it in the first list
897 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
898 struct sk_buff_head *head)
900 if (!skb_queue_empty(list)) {
901 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
902 head->qlen += list->qlen;
907 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
908 * @list: the new list to add
909 * @head: the place to add it in the first list
911 * Each of the lists is a queue.
912 * The list at @list is reinitialised
914 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
915 struct sk_buff_head *head)
917 if (!skb_queue_empty(list)) {
918 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
919 head->qlen += list->qlen;
920 __skb_queue_head_init(list);
925 * __skb_queue_after - queue a buffer at the list head
927 * @prev: place after this buffer
928 * @newsk: buffer to queue
930 * Queue a buffer int the middle of a list. This function takes no locks
931 * and you must therefore hold required locks before calling it.
933 * A buffer cannot be placed on two lists at the same time.
935 static inline void __skb_queue_after(struct sk_buff_head *list,
936 struct sk_buff *prev,
937 struct sk_buff *newsk)
939 __skb_insert(newsk, prev, prev->next, list);
942 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
943 struct sk_buff_head *list);
945 static inline void __skb_queue_before(struct sk_buff_head *list,
946 struct sk_buff *next,
947 struct sk_buff *newsk)
949 __skb_insert(newsk, next->prev, next, list);
953 * __skb_queue_head - queue a buffer at the list head
955 * @newsk: buffer to queue
957 * Queue a buffer at the start of a list. This function takes no locks
958 * and you must therefore hold required locks before calling it.
960 * A buffer cannot be placed on two lists at the same time.
962 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
963 static inline void __skb_queue_head(struct sk_buff_head *list,
964 struct sk_buff *newsk)
966 __skb_queue_after(list, (struct sk_buff *)list, newsk);
970 * __skb_queue_tail - queue a buffer at the list tail
972 * @newsk: buffer to queue
974 * Queue a buffer at the end of a list. This function takes no locks
975 * and you must therefore hold required locks before calling it.
977 * A buffer cannot be placed on two lists at the same time.
979 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
980 static inline void __skb_queue_tail(struct sk_buff_head *list,
981 struct sk_buff *newsk)
983 __skb_queue_before(list, (struct sk_buff *)list, newsk);
987 * remove sk_buff from list. _Must_ be called atomically, and with
990 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
991 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
993 struct sk_buff *next, *prev;
998 skb->next = skb->prev = NULL;
1004 * __skb_dequeue - remove from the head of the queue
1005 * @list: list to dequeue from
1007 * Remove the head of the list. This function does not take any locks
1008 * so must be used with appropriate locks held only. The head item is
1009 * returned or %NULL if the list is empty.
1011 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1012 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1014 struct sk_buff *skb = skb_peek(list);
1016 __skb_unlink(skb, list);
1021 * __skb_dequeue_tail - remove from the tail of the queue
1022 * @list: list to dequeue from
1024 * Remove the tail of the list. This function does not take any locks
1025 * so must be used with appropriate locks held only. The tail item is
1026 * returned or %NULL if the list is empty.
1028 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1029 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1031 struct sk_buff *skb = skb_peek_tail(list);
1033 __skb_unlink(skb, list);
1038 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1040 return skb->data_len;
1043 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1045 return skb->len - skb->data_len;
1048 static inline int skb_pagelen(const struct sk_buff *skb)
1052 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1053 len += skb_shinfo(skb)->frags[i].size;
1054 return len + skb_headlen(skb);
1057 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1058 struct page *page, int off, int size)
1060 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1063 frag->page_offset = off;
1065 skb_shinfo(skb)->nr_frags = i + 1;
1068 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1071 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1072 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1073 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1075 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1076 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1078 return skb->head + skb->tail;
1081 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1083 skb->tail = skb->data - skb->head;
1086 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1088 skb_reset_tail_pointer(skb);
1089 skb->tail += offset;
1091 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1092 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1097 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1099 skb->tail = skb->data;
1102 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1104 skb->tail = skb->data + offset;
1107 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1110 * Add data to an sk_buff
1112 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1113 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1115 unsigned char *tmp = skb_tail_pointer(skb);
1116 SKB_LINEAR_ASSERT(skb);
1122 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1123 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1130 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1131 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1134 BUG_ON(skb->len < skb->data_len);
1135 return skb->data += len;
1138 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1140 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1142 if (len > skb_headlen(skb) &&
1143 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1146 return skb->data += len;
1149 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1151 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1154 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1156 if (likely(len <= skb_headlen(skb)))
1158 if (unlikely(len > skb->len))
1160 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1164 * skb_headroom - bytes at buffer head
1165 * @skb: buffer to check
1167 * Return the number of bytes of free space at the head of an &sk_buff.
1169 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1171 return skb->data - skb->head;
1175 * skb_tailroom - bytes at buffer end
1176 * @skb: buffer to check
1178 * Return the number of bytes of free space at the tail of an sk_buff
1180 static inline int skb_tailroom(const struct sk_buff *skb)
1182 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1186 * skb_reserve - adjust headroom
1187 * @skb: buffer to alter
1188 * @len: bytes to move
1190 * Increase the headroom of an empty &sk_buff by reducing the tail
1191 * room. This is only allowed for an empty buffer.
1193 static inline void skb_reserve(struct sk_buff *skb, int len)
1199 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1200 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1202 return skb->head + skb->transport_header;
1205 static inline void skb_reset_transport_header(struct sk_buff *skb)
1207 skb->transport_header = skb->data - skb->head;
1210 static inline void skb_set_transport_header(struct sk_buff *skb,
1213 skb_reset_transport_header(skb);
1214 skb->transport_header += offset;
1217 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1219 return skb->head + skb->network_header;
1222 static inline void skb_reset_network_header(struct sk_buff *skb)
1224 skb->network_header = skb->data - skb->head;
1227 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1229 skb_reset_network_header(skb);
1230 skb->network_header += offset;
1233 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1235 return skb->head + skb->mac_header;
1238 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1240 return skb->mac_header != ~0U;
1243 static inline void skb_reset_mac_header(struct sk_buff *skb)
1245 skb->mac_header = skb->data - skb->head;
1248 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1250 skb_reset_mac_header(skb);
1251 skb->mac_header += offset;
1254 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1256 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1258 return skb->transport_header;
1261 static inline void skb_reset_transport_header(struct sk_buff *skb)
1263 skb->transport_header = skb->data;
1266 static inline void skb_set_transport_header(struct sk_buff *skb,
1269 skb->transport_header = skb->data + offset;
1272 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1274 return skb->network_header;
1277 static inline void skb_reset_network_header(struct sk_buff *skb)
1279 skb->network_header = skb->data;
1282 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1284 skb->network_header = skb->data + offset;
1287 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1289 return skb->mac_header;
1292 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1294 return skb->mac_header != NULL;
1297 static inline void skb_reset_mac_header(struct sk_buff *skb)
1299 skb->mac_header = skb->data;
1302 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1304 skb->mac_header = skb->data + offset;
1306 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1308 static inline int skb_transport_offset(const struct sk_buff *skb)
1310 return skb_transport_header(skb) - skb->data;
1313 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1315 return skb->transport_header - skb->network_header;
1318 static inline int skb_network_offset(const struct sk_buff *skb)
1320 return skb_network_header(skb) - skb->data;
1324 * CPUs often take a performance hit when accessing unaligned memory
1325 * locations. The actual performance hit varies, it can be small if the
1326 * hardware handles it or large if we have to take an exception and fix it
1329 * Since an ethernet header is 14 bytes network drivers often end up with
1330 * the IP header at an unaligned offset. The IP header can be aligned by
1331 * shifting the start of the packet by 2 bytes. Drivers should do this
1334 * skb_reserve(NET_IP_ALIGN);
1336 * The downside to this alignment of the IP header is that the DMA is now
1337 * unaligned. On some architectures the cost of an unaligned DMA is high
1338 * and this cost outweighs the gains made by aligning the IP header.
1340 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1343 #ifndef NET_IP_ALIGN
1344 #define NET_IP_ALIGN 2
1348 * The networking layer reserves some headroom in skb data (via
1349 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1350 * the header has to grow. In the default case, if the header has to grow
1351 * 32 bytes or less we avoid the reallocation.
1353 * Unfortunately this headroom changes the DMA alignment of the resulting
1354 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1355 * on some architectures. An architecture can override this value,
1356 * perhaps setting it to a cacheline in size (since that will maintain
1357 * cacheline alignment of the DMA). It must be a power of 2.
1359 * Various parts of the networking layer expect at least 32 bytes of
1360 * headroom, you should not reduce this.
1363 #define NET_SKB_PAD 32
1366 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1368 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1370 if (unlikely(skb->data_len)) {
1375 skb_set_tail_pointer(skb, len);
1378 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1380 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1383 return ___pskb_trim(skb, len);
1384 __skb_trim(skb, len);
1388 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1390 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1394 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1395 * @skb: buffer to alter
1398 * This is identical to pskb_trim except that the caller knows that
1399 * the skb is not cloned so we should never get an error due to out-
1402 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1404 int err = pskb_trim(skb, len);
1409 * skb_orphan - orphan a buffer
1410 * @skb: buffer to orphan
1412 * If a buffer currently has an owner then we call the owner's
1413 * destructor function and make the @skb unowned. The buffer continues
1414 * to exist but is no longer charged to its former owner.
1416 static inline void skb_orphan(struct sk_buff *skb)
1418 if (skb->destructor)
1419 skb->destructor(skb);
1420 skb->destructor = NULL;
1425 * __skb_queue_purge - empty a list
1426 * @list: list to empty
1428 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1429 * the list and one reference dropped. This function does not take the
1430 * list lock and the caller must hold the relevant locks to use it.
1432 extern void skb_queue_purge(struct sk_buff_head *list);
1433 static inline void __skb_queue_purge(struct sk_buff_head *list)
1435 struct sk_buff *skb;
1436 while ((skb = __skb_dequeue(list)) != NULL)
1441 * __dev_alloc_skb - allocate an skbuff for receiving
1442 * @length: length to allocate
1443 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1445 * Allocate a new &sk_buff and assign it a usage count of one. The
1446 * buffer has unspecified headroom built in. Users should allocate
1447 * the headroom they think they need without accounting for the
1448 * built in space. The built in space is used for optimisations.
1450 * %NULL is returned if there is no free memory.
1452 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1455 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1457 skb_reserve(skb, NET_SKB_PAD);
1461 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1463 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1464 unsigned int length, gfp_t gfp_mask);
1467 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1468 * @dev: network device to receive on
1469 * @length: length to allocate
1471 * Allocate a new &sk_buff and assign it a usage count of one. The
1472 * buffer has unspecified headroom built in. Users should allocate
1473 * the headroom they think they need without accounting for the
1474 * built in space. The built in space is used for optimisations.
1476 * %NULL is returned if there is no free memory. Although this function
1477 * allocates memory it can be called from an interrupt.
1479 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1480 unsigned int length)
1482 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1485 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1488 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1489 * @dev: network device to receive on
1491 * Allocate a new page node local to the specified device.
1493 * %NULL is returned if there is no free memory.
1495 static inline struct page *netdev_alloc_page(struct net_device *dev)
1497 return __netdev_alloc_page(dev, GFP_ATOMIC);
1500 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1506 * skb_clone_writable - is the header of a clone writable
1507 * @skb: buffer to check
1508 * @len: length up to which to write
1510 * Returns true if modifying the header part of the cloned buffer
1511 * does not requires the data to be copied.
1513 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1515 return !skb_header_cloned(skb) &&
1516 skb_headroom(skb) + len <= skb->hdr_len;
1519 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1524 if (headroom < NET_SKB_PAD)
1525 headroom = NET_SKB_PAD;
1526 if (headroom > skb_headroom(skb))
1527 delta = headroom - skb_headroom(skb);
1529 if (delta || cloned)
1530 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1536 * skb_cow - copy header of skb when it is required
1537 * @skb: buffer to cow
1538 * @headroom: needed headroom
1540 * If the skb passed lacks sufficient headroom or its data part
1541 * is shared, data is reallocated. If reallocation fails, an error
1542 * is returned and original skb is not changed.
1544 * The result is skb with writable area skb->head...skb->tail
1545 * and at least @headroom of space at head.
1547 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1549 return __skb_cow(skb, headroom, skb_cloned(skb));
1553 * skb_cow_head - skb_cow but only making the head writable
1554 * @skb: buffer to cow
1555 * @headroom: needed headroom
1557 * This function is identical to skb_cow except that we replace the
1558 * skb_cloned check by skb_header_cloned. It should be used when
1559 * you only need to push on some header and do not need to modify
1562 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1564 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1568 * skb_padto - pad an skbuff up to a minimal size
1569 * @skb: buffer to pad
1570 * @len: minimal length
1572 * Pads up a buffer to ensure the trailing bytes exist and are
1573 * blanked. If the buffer already contains sufficient data it
1574 * is untouched. Otherwise it is extended. Returns zero on
1575 * success. The skb is freed on error.
1578 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1580 unsigned int size = skb->len;
1581 if (likely(size >= len))
1583 return skb_pad(skb, len - size);
1586 static inline int skb_add_data(struct sk_buff *skb,
1587 char __user *from, int copy)
1589 const int off = skb->len;
1591 if (skb->ip_summed == CHECKSUM_NONE) {
1593 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1596 skb->csum = csum_block_add(skb->csum, csum, off);
1599 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1602 __skb_trim(skb, off);
1606 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1607 struct page *page, int off)
1610 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1612 return page == frag->page &&
1613 off == frag->page_offset + frag->size;
1618 static inline int __skb_linearize(struct sk_buff *skb)
1620 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1624 * skb_linearize - convert paged skb to linear one
1625 * @skb: buffer to linarize
1627 * If there is no free memory -ENOMEM is returned, otherwise zero
1628 * is returned and the old skb data released.
1630 static inline int skb_linearize(struct sk_buff *skb)
1632 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1636 * skb_linearize_cow - make sure skb is linear and writable
1637 * @skb: buffer to process
1639 * If there is no free memory -ENOMEM is returned, otherwise zero
1640 * is returned and the old skb data released.
1642 static inline int skb_linearize_cow(struct sk_buff *skb)
1644 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1645 __skb_linearize(skb) : 0;
1649 * skb_postpull_rcsum - update checksum for received skb after pull
1650 * @skb: buffer to update
1651 * @start: start of data before pull
1652 * @len: length of data pulled
1654 * After doing a pull on a received packet, you need to call this to
1655 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1656 * CHECKSUM_NONE so that it can be recomputed from scratch.
1659 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1660 const void *start, unsigned int len)
1662 if (skb->ip_summed == CHECKSUM_COMPLETE)
1663 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1666 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1669 * pskb_trim_rcsum - trim received skb and update checksum
1670 * @skb: buffer to trim
1673 * This is exactly the same as pskb_trim except that it ensures the
1674 * checksum of received packets are still valid after the operation.
1677 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1679 if (likely(len >= skb->len))
1681 if (skb->ip_summed == CHECKSUM_COMPLETE)
1682 skb->ip_summed = CHECKSUM_NONE;
1683 return __pskb_trim(skb, len);
1686 #define skb_queue_walk(queue, skb) \
1687 for (skb = (queue)->next; \
1688 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1691 #define skb_queue_walk_safe(queue, skb, tmp) \
1692 for (skb = (queue)->next, tmp = skb->next; \
1693 skb != (struct sk_buff *)(queue); \
1694 skb = tmp, tmp = skb->next)
1696 #define skb_queue_walk_from(queue, skb) \
1697 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1700 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1701 for (tmp = skb->next; \
1702 skb != (struct sk_buff *)(queue); \
1703 skb = tmp, tmp = skb->next)
1705 #define skb_queue_reverse_walk(queue, skb) \
1706 for (skb = (queue)->prev; \
1707 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1711 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1712 int *peeked, int *err);
1713 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1714 int noblock, int *err);
1715 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1716 struct poll_table_struct *wait);
1717 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1718 int offset, struct iovec *to,
1720 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1723 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1727 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1728 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1729 unsigned int flags);
1730 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1731 int len, __wsum csum);
1732 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1734 extern int skb_store_bits(struct sk_buff *skb, int offset,
1735 const void *from, int len);
1736 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1737 int offset, u8 *to, int len,
1739 extern int skb_splice_bits(struct sk_buff *skb,
1740 unsigned int offset,
1741 struct pipe_inode_info *pipe,
1743 unsigned int flags);
1744 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1745 extern void skb_split(struct sk_buff *skb,
1746 struct sk_buff *skb1, const u32 len);
1747 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1750 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1752 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1753 int len, void *buffer)
1755 int hlen = skb_headlen(skb);
1757 if (hlen - offset >= len)
1758 return skb->data + offset;
1760 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1766 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1768 const unsigned int len)
1770 memcpy(to, skb->data, len);
1773 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1774 const int offset, void *to,
1775 const unsigned int len)
1777 memcpy(to, skb->data + offset, len);
1780 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1782 const unsigned int len)
1784 memcpy(skb->data, from, len);
1787 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1790 const unsigned int len)
1792 memcpy(skb->data + offset, from, len);
1795 extern void skb_init(void);
1797 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1803 * skb_get_timestamp - get timestamp from a skb
1804 * @skb: skb to get stamp from
1805 * @stamp: pointer to struct timeval to store stamp in
1807 * Timestamps are stored in the skb as offsets to a base timestamp.
1808 * This function converts the offset back to a struct timeval and stores
1811 static inline void skb_get_timestamp(const struct sk_buff *skb,
1812 struct timeval *stamp)
1814 *stamp = ktime_to_timeval(skb->tstamp);
1817 static inline void skb_get_timestampns(const struct sk_buff *skb,
1818 struct timespec *stamp)
1820 *stamp = ktime_to_timespec(skb->tstamp);
1823 static inline void __net_timestamp(struct sk_buff *skb)
1825 skb->tstamp = ktime_get_real();
1828 static inline ktime_t net_timedelta(ktime_t t)
1830 return ktime_sub(ktime_get_real(), t);
1833 static inline ktime_t net_invalid_timestamp(void)
1835 return ktime_set(0, 0);
1839 * skb_tstamp_tx - queue clone of skb with send time stamps
1840 * @orig_skb: the original outgoing packet
1841 * @hwtstamps: hardware time stamps, may be NULL if not available
1843 * If the skb has a socket associated, then this function clones the
1844 * skb (thus sharing the actual data and optional structures), stores
1845 * the optional hardware time stamping information (if non NULL) or
1846 * generates a software time stamp (otherwise), then queues the clone
1847 * to the error queue of the socket. Errors are silently ignored.
1849 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1850 struct skb_shared_hwtstamps *hwtstamps);
1852 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1853 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1855 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1857 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1861 * skb_checksum_complete - Calculate checksum of an entire packet
1862 * @skb: packet to process
1864 * This function calculates the checksum over the entire packet plus
1865 * the value of skb->csum. The latter can be used to supply the
1866 * checksum of a pseudo header as used by TCP/UDP. It returns the
1869 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1870 * this function can be used to verify that checksum on received
1871 * packets. In that case the function should return zero if the
1872 * checksum is correct. In particular, this function will return zero
1873 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1874 * hardware has already verified the correctness of the checksum.
1876 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1878 return skb_csum_unnecessary(skb) ?
1879 0 : __skb_checksum_complete(skb);
1882 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1883 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1884 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1886 if (nfct && atomic_dec_and_test(&nfct->use))
1887 nf_conntrack_destroy(nfct);
1889 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1892 atomic_inc(&nfct->use);
1894 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1897 atomic_inc(&skb->users);
1899 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1905 #ifdef CONFIG_BRIDGE_NETFILTER
1906 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1908 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1911 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1914 atomic_inc(&nf_bridge->use);
1916 #endif /* CONFIG_BRIDGE_NETFILTER */
1917 static inline void nf_reset(struct sk_buff *skb)
1919 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1920 nf_conntrack_put(skb->nfct);
1922 nf_conntrack_put_reasm(skb->nfct_reasm);
1923 skb->nfct_reasm = NULL;
1925 #ifdef CONFIG_BRIDGE_NETFILTER
1926 nf_bridge_put(skb->nf_bridge);
1927 skb->nf_bridge = NULL;
1931 /* Note: This doesn't put any conntrack and bridge info in dst. */
1932 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1934 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1935 dst->nfct = src->nfct;
1936 nf_conntrack_get(src->nfct);
1937 dst->nfctinfo = src->nfctinfo;
1938 dst->nfct_reasm = src->nfct_reasm;
1939 nf_conntrack_get_reasm(src->nfct_reasm);
1941 #ifdef CONFIG_BRIDGE_NETFILTER
1942 dst->nf_bridge = src->nf_bridge;
1943 nf_bridge_get(src->nf_bridge);
1947 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1949 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1950 nf_conntrack_put(dst->nfct);
1951 nf_conntrack_put_reasm(dst->nfct_reasm);
1953 #ifdef CONFIG_BRIDGE_NETFILTER
1954 nf_bridge_put(dst->nf_bridge);
1956 __nf_copy(dst, src);
1959 #ifdef CONFIG_NETWORK_SECMARK
1960 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1962 to->secmark = from->secmark;
1965 static inline void skb_init_secmark(struct sk_buff *skb)
1970 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1973 static inline void skb_init_secmark(struct sk_buff *skb)
1977 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1979 skb->queue_mapping = queue_mapping;
1982 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
1984 return skb->queue_mapping;
1987 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1989 to->queue_mapping = from->queue_mapping;
1992 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
1994 skb->queue_mapping = rx_queue + 1;
1997 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
1999 return skb->queue_mapping - 1;
2002 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2004 return (skb->queue_mapping != 0);
2007 extern u16 skb_tx_hash(const struct net_device *dev,
2008 const struct sk_buff *skb);
2011 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2016 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2022 static inline int skb_is_gso(const struct sk_buff *skb)
2024 return skb_shinfo(skb)->gso_size;
2027 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2029 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2032 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2034 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2036 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2037 * wanted then gso_type will be set. */
2038 struct skb_shared_info *shinfo = skb_shinfo(skb);
2039 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2040 __skb_warn_lro_forwarding(skb);
2046 static inline void skb_forward_csum(struct sk_buff *skb)
2048 /* Unfortunately we don't support this one. Any brave souls? */
2049 if (skb->ip_summed == CHECKSUM_COMPLETE)
2050 skb->ip_summed = CHECKSUM_NONE;
2053 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2054 #endif /* __KERNEL__ */
2055 #endif /* _LINUX_SKBUFF_H */