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 struct sk_buff *frag_list;
198 struct skb_shared_hwtstamps hwtstamps;
199 skb_frag_t frags[MAX_SKB_FRAGS];
200 #ifdef CONFIG_HAS_DMA
201 dma_addr_t dma_maps[MAX_SKB_FRAGS + 1];
203 /* Intermediate layers must ensure that destructor_arg
204 * remains valid until skb destructor */
205 void * destructor_arg;
208 /* We divide dataref into two halves. The higher 16 bits hold references
209 * to the payload part of skb->data. The lower 16 bits hold references to
210 * the entire skb->data. A clone of a headerless skb holds the length of
211 * the header in skb->hdr_len.
213 * All users must obey the rule that the skb->data reference count must be
214 * greater than or equal to the payload reference count.
216 * Holding a reference to the payload part means that the user does not
217 * care about modifications to the header part of skb->data.
219 #define SKB_DATAREF_SHIFT 16
220 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
224 SKB_FCLONE_UNAVAILABLE,
230 SKB_GSO_TCPV4 = 1 << 0,
231 SKB_GSO_UDP = 1 << 1,
233 /* This indicates the skb is from an untrusted source. */
234 SKB_GSO_DODGY = 1 << 2,
236 /* This indicates the tcp segment has CWR set. */
237 SKB_GSO_TCP_ECN = 1 << 3,
239 SKB_GSO_TCPV6 = 1 << 4,
241 SKB_GSO_FCOE = 1 << 5,
244 #if BITS_PER_LONG > 32
245 #define NET_SKBUFF_DATA_USES_OFFSET 1
248 #ifdef NET_SKBUFF_DATA_USES_OFFSET
249 typedef unsigned int sk_buff_data_t;
251 typedef unsigned char *sk_buff_data_t;
255 * struct sk_buff - socket buffer
256 * @next: Next buffer in list
257 * @prev: Previous buffer in list
258 * @sk: Socket we are owned by
259 * @tstamp: Time we arrived
260 * @dev: Device we arrived on/are leaving by
261 * @transport_header: Transport layer header
262 * @network_header: Network layer header
263 * @mac_header: Link layer header
264 * @dst: destination entry
265 * @sp: the security path, used for xfrm
266 * @cb: Control buffer. Free for use by every layer. Put private vars here
267 * @len: Length of actual data
268 * @data_len: Data length
269 * @mac_len: Length of link layer header
270 * @hdr_len: writable header length of cloned skb
271 * @csum: Checksum (must include start/offset pair)
272 * @csum_start: Offset from skb->head where checksumming should start
273 * @csum_offset: Offset from csum_start where checksum should be stored
274 * @local_df: allow local fragmentation
275 * @cloned: Head may be cloned (check refcnt to be sure)
276 * @nohdr: Payload reference only, must not modify header
277 * @pkt_type: Packet class
278 * @fclone: skbuff clone status
279 * @ip_summed: Driver fed us an IP checksum
280 * @priority: Packet queueing priority
281 * @users: User count - see {datagram,tcp}.c
282 * @protocol: Packet protocol from driver
283 * @truesize: Buffer size
284 * @head: Head of buffer
285 * @data: Data head pointer
286 * @tail: Tail pointer
288 * @destructor: Destruct function
289 * @mark: Generic packet mark
290 * @nfct: Associated connection, if any
291 * @ipvs_property: skbuff is owned by ipvs
292 * @peeked: this packet has been seen already, so stats have been
293 * done for it, don't do them again
294 * @nf_trace: netfilter packet trace flag
295 * @nfctinfo: Relationship of this skb to the connection
296 * @nfct_reasm: netfilter conntrack re-assembly pointer
297 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
298 * @iif: ifindex of device we arrived on
299 * @queue_mapping: Queue mapping for multiqueue devices
300 * @tc_index: Traffic control index
301 * @tc_verd: traffic control verdict
302 * @ndisc_nodetype: router type (from link layer)
303 * @do_not_encrypt: set to prevent encryption of this frame
304 * @requeue: set to indicate that the wireless core should attempt
305 * a software retry on this frame if we failed to
306 * receive an ACK for it
307 * @dma_cookie: a cookie to one of several possible DMA operations
308 * done by skb DMA functions
309 * @secmark: security marking
310 * @vlan_tci: vlan tag control information
314 /* These two members must be first. */
315 struct sk_buff *next;
316 struct sk_buff *prev;
320 struct net_device *dev;
322 unsigned long _skb_dst;
327 * This is the control buffer. It is free to use for every
328 * layer. Please put your private variables there. If you
329 * want to keep them across layers you have to do a skb_clone()
330 * first. This is owned by whoever has the skb queued ATM.
358 void (*destructor)(struct sk_buff *skb);
359 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
360 struct nf_conntrack *nfct;
361 struct sk_buff *nfct_reasm;
363 #ifdef CONFIG_BRIDGE_NETFILTER
364 struct nf_bridge_info *nf_bridge;
369 #ifdef CONFIG_NET_SCHED
370 __u16 tc_index; /* traffic control index */
371 #ifdef CONFIG_NET_CLS_ACT
372 __u16 tc_verd; /* traffic control verdict */
375 #ifdef CONFIG_IPV6_NDISC_NODETYPE
376 __u8 ndisc_nodetype:2;
378 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
379 __u8 do_not_encrypt:1;
382 /* 0/13/14 bit hole */
384 #ifdef CONFIG_NET_DMA
385 dma_cookie_t dma_cookie;
387 #ifdef CONFIG_NETWORK_SECMARK
395 sk_buff_data_t transport_header;
396 sk_buff_data_t network_header;
397 sk_buff_data_t mac_header;
398 /* These elements must be at the end, see alloc_skb() for details. */
403 unsigned int truesize;
409 * Handling routines are only of interest to the kernel
411 #include <linux/slab.h>
413 #include <asm/system.h>
415 #ifdef CONFIG_HAS_DMA
416 #include <linux/dma-mapping.h>
417 extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
418 enum dma_data_direction dir);
419 extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
420 enum dma_data_direction dir);
423 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
425 return (struct dst_entry *)skb->_skb_dst;
428 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
430 skb->_skb_dst = (unsigned long)dst;
433 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
435 return (struct rtable *)skb_dst(skb);
438 extern void kfree_skb(struct sk_buff *skb);
439 extern void consume_skb(struct sk_buff *skb);
440 extern void __kfree_skb(struct sk_buff *skb);
441 extern struct sk_buff *__alloc_skb(unsigned int size,
442 gfp_t priority, int fclone, int node);
443 static inline struct sk_buff *alloc_skb(unsigned int size,
446 return __alloc_skb(size, priority, 0, -1);
449 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
452 return __alloc_skb(size, priority, 1, -1);
455 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
457 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
458 extern struct sk_buff *skb_clone(struct sk_buff *skb,
460 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
462 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
464 extern int pskb_expand_head(struct sk_buff *skb,
465 int nhead, int ntail,
467 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
468 unsigned int headroom);
469 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
470 int newheadroom, int newtailroom,
472 extern int skb_to_sgvec(struct sk_buff *skb,
473 struct scatterlist *sg, int offset,
475 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
476 struct sk_buff **trailer);
477 extern int skb_pad(struct sk_buff *skb, int pad);
478 #define dev_kfree_skb(a) consume_skb(a)
479 #define dev_consume_skb(a) kfree_skb_clean(a)
480 extern void skb_over_panic(struct sk_buff *skb, int len,
482 extern void skb_under_panic(struct sk_buff *skb, int len,
485 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
486 int getfrag(void *from, char *to, int offset,
487 int len,int odd, struct sk_buff *skb),
488 void *from, int length);
495 __u32 stepped_offset;
496 struct sk_buff *root_skb;
497 struct sk_buff *cur_skb;
501 extern void skb_prepare_seq_read(struct sk_buff *skb,
502 unsigned int from, unsigned int to,
503 struct skb_seq_state *st);
504 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
505 struct skb_seq_state *st);
506 extern void skb_abort_seq_read(struct skb_seq_state *st);
508 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
509 unsigned int to, struct ts_config *config,
510 struct ts_state *state);
512 #ifdef NET_SKBUFF_DATA_USES_OFFSET
513 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
515 return skb->head + skb->end;
518 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
525 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
527 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
529 return &skb_shinfo(skb)->hwtstamps;
532 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
534 return &skb_shinfo(skb)->tx_flags;
538 * skb_queue_empty - check if a queue is empty
541 * Returns true if the queue is empty, false otherwise.
543 static inline int skb_queue_empty(const struct sk_buff_head *list)
545 return list->next == (struct sk_buff *)list;
549 * skb_queue_is_last - check if skb is the last entry in the queue
553 * Returns true if @skb is the last buffer on the list.
555 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
556 const struct sk_buff *skb)
558 return (skb->next == (struct sk_buff *) list);
562 * skb_queue_is_first - check if skb is the first entry in the queue
566 * Returns true if @skb is the first buffer on the list.
568 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
569 const struct sk_buff *skb)
571 return (skb->prev == (struct sk_buff *) list);
575 * skb_queue_next - return the next packet in the queue
577 * @skb: current buffer
579 * Return the next packet in @list after @skb. It is only valid to
580 * call this if skb_queue_is_last() evaluates to false.
582 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
583 const struct sk_buff *skb)
585 /* This BUG_ON may seem severe, but if we just return then we
586 * are going to dereference garbage.
588 BUG_ON(skb_queue_is_last(list, skb));
593 * skb_queue_prev - return the prev packet in the queue
595 * @skb: current buffer
597 * Return the prev packet in @list before @skb. It is only valid to
598 * call this if skb_queue_is_first() evaluates to false.
600 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
601 const struct sk_buff *skb)
603 /* This BUG_ON may seem severe, but if we just return then we
604 * are going to dereference garbage.
606 BUG_ON(skb_queue_is_first(list, skb));
611 * skb_get - reference buffer
612 * @skb: buffer to reference
614 * Makes another reference to a socket buffer and returns a pointer
617 static inline struct sk_buff *skb_get(struct sk_buff *skb)
619 atomic_inc(&skb->users);
624 * If users == 1, we are the only owner and are can avoid redundant
629 * skb_cloned - is the buffer a clone
630 * @skb: buffer to check
632 * Returns true if the buffer was generated with skb_clone() and is
633 * one of multiple shared copies of the buffer. Cloned buffers are
634 * shared data so must not be written to under normal circumstances.
636 static inline int skb_cloned(const struct sk_buff *skb)
638 return skb->cloned &&
639 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
643 * skb_header_cloned - is the header a clone
644 * @skb: buffer to check
646 * Returns true if modifying the header part of the buffer requires
647 * the data to be copied.
649 static inline int skb_header_cloned(const struct sk_buff *skb)
656 dataref = atomic_read(&skb_shinfo(skb)->dataref);
657 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
662 * skb_header_release - release reference to header
663 * @skb: buffer to operate on
665 * Drop a reference to the header part of the buffer. This is done
666 * by acquiring a payload reference. You must not read from the header
667 * part of skb->data after this.
669 static inline void skb_header_release(struct sk_buff *skb)
673 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
677 * skb_shared - is the buffer shared
678 * @skb: buffer to check
680 * Returns true if more than one person has a reference to this
683 static inline int skb_shared(const struct sk_buff *skb)
685 return atomic_read(&skb->users) != 1;
689 * skb_share_check - check if buffer is shared and if so clone it
690 * @skb: buffer to check
691 * @pri: priority for memory allocation
693 * If the buffer is shared the buffer is cloned and the old copy
694 * drops a reference. A new clone with a single reference is returned.
695 * If the buffer is not shared the original buffer is returned. When
696 * being called from interrupt status or with spinlocks held pri must
699 * NULL is returned on a memory allocation failure.
701 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
704 might_sleep_if(pri & __GFP_WAIT);
705 if (skb_shared(skb)) {
706 struct sk_buff *nskb = skb_clone(skb, pri);
714 * Copy shared buffers into a new sk_buff. We effectively do COW on
715 * packets to handle cases where we have a local reader and forward
716 * and a couple of other messy ones. The normal one is tcpdumping
717 * a packet thats being forwarded.
721 * skb_unshare - make a copy of a shared buffer
722 * @skb: buffer to check
723 * @pri: priority for memory allocation
725 * If the socket buffer is a clone then this function creates a new
726 * copy of the data, drops a reference count on the old copy and returns
727 * the new copy with the reference count at 1. If the buffer is not a clone
728 * the original buffer is returned. When called with a spinlock held or
729 * from interrupt state @pri must be %GFP_ATOMIC
731 * %NULL is returned on a memory allocation failure.
733 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
736 might_sleep_if(pri & __GFP_WAIT);
737 if (skb_cloned(skb)) {
738 struct sk_buff *nskb = skb_copy(skb, pri);
739 kfree_skb(skb); /* Free our shared copy */
747 * @list_: list to peek at
749 * Peek an &sk_buff. Unlike most other operations you _MUST_
750 * be careful with this one. A peek leaves the buffer on the
751 * list and someone else may run off with it. You must hold
752 * the appropriate locks or have a private queue to do this.
754 * Returns %NULL for an empty list or a pointer to the head element.
755 * The reference count is not incremented and the reference is therefore
756 * volatile. Use with caution.
758 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
760 struct sk_buff *list = ((struct sk_buff *)list_)->next;
761 if (list == (struct sk_buff *)list_)
768 * @list_: list to peek at
770 * Peek an &sk_buff. Unlike most other operations you _MUST_
771 * be careful with this one. A peek leaves the buffer on the
772 * list and someone else may run off with it. You must hold
773 * the appropriate locks or have a private queue to do this.
775 * Returns %NULL for an empty list or a pointer to the tail element.
776 * The reference count is not incremented and the reference is therefore
777 * volatile. Use with caution.
779 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
781 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
782 if (list == (struct sk_buff *)list_)
788 * skb_queue_len - get queue length
789 * @list_: list to measure
791 * Return the length of an &sk_buff queue.
793 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
799 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
800 * @list: queue to initialize
802 * This initializes only the list and queue length aspects of
803 * an sk_buff_head object. This allows to initialize the list
804 * aspects of an sk_buff_head without reinitializing things like
805 * the spinlock. It can also be used for on-stack sk_buff_head
806 * objects where the spinlock is known to not be used.
808 static inline void __skb_queue_head_init(struct sk_buff_head *list)
810 list->prev = list->next = (struct sk_buff *)list;
815 * This function creates a split out lock class for each invocation;
816 * this is needed for now since a whole lot of users of the skb-queue
817 * infrastructure in drivers have different locking usage (in hardirq)
818 * than the networking core (in softirq only). In the long run either the
819 * network layer or drivers should need annotation to consolidate the
820 * main types of usage into 3 classes.
822 static inline void skb_queue_head_init(struct sk_buff_head *list)
824 spin_lock_init(&list->lock);
825 __skb_queue_head_init(list);
828 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
829 struct lock_class_key *class)
831 skb_queue_head_init(list);
832 lockdep_set_class(&list->lock, class);
836 * Insert an sk_buff on a list.
838 * The "__skb_xxxx()" functions are the non-atomic ones that
839 * can only be called with interrupts disabled.
841 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
842 static inline void __skb_insert(struct sk_buff *newsk,
843 struct sk_buff *prev, struct sk_buff *next,
844 struct sk_buff_head *list)
848 next->prev = prev->next = newsk;
852 static inline void __skb_queue_splice(const struct sk_buff_head *list,
853 struct sk_buff *prev,
854 struct sk_buff *next)
856 struct sk_buff *first = list->next;
857 struct sk_buff *last = list->prev;
867 * skb_queue_splice - join two skb lists, this is designed for stacks
868 * @list: the new list to add
869 * @head: the place to add it in the first list
871 static inline void skb_queue_splice(const struct sk_buff_head *list,
872 struct sk_buff_head *head)
874 if (!skb_queue_empty(list)) {
875 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
876 head->qlen += list->qlen;
881 * skb_queue_splice - join two skb lists and reinitialise the emptied list
882 * @list: the new list to add
883 * @head: the place to add it in the first list
885 * The list at @list is reinitialised
887 static inline void skb_queue_splice_init(struct sk_buff_head *list,
888 struct sk_buff_head *head)
890 if (!skb_queue_empty(list)) {
891 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
892 head->qlen += list->qlen;
893 __skb_queue_head_init(list);
898 * skb_queue_splice_tail - join two skb lists, each list being a queue
899 * @list: the new list to add
900 * @head: the place to add it in the first list
902 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
903 struct sk_buff_head *head)
905 if (!skb_queue_empty(list)) {
906 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
907 head->qlen += list->qlen;
912 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
913 * @list: the new list to add
914 * @head: the place to add it in the first list
916 * Each of the lists is a queue.
917 * The list at @list is reinitialised
919 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
920 struct sk_buff_head *head)
922 if (!skb_queue_empty(list)) {
923 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
924 head->qlen += list->qlen;
925 __skb_queue_head_init(list);
930 * __skb_queue_after - queue a buffer at the list head
932 * @prev: place after this buffer
933 * @newsk: buffer to queue
935 * Queue a buffer int the middle of a list. This function takes no locks
936 * and you must therefore hold required locks before calling it.
938 * A buffer cannot be placed on two lists at the same time.
940 static inline void __skb_queue_after(struct sk_buff_head *list,
941 struct sk_buff *prev,
942 struct sk_buff *newsk)
944 __skb_insert(newsk, prev, prev->next, list);
947 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
948 struct sk_buff_head *list);
950 static inline void __skb_queue_before(struct sk_buff_head *list,
951 struct sk_buff *next,
952 struct sk_buff *newsk)
954 __skb_insert(newsk, next->prev, next, list);
958 * __skb_queue_head - queue a buffer at the list head
960 * @newsk: buffer to queue
962 * Queue a buffer at the start of a list. This function takes no locks
963 * and you must therefore hold required locks before calling it.
965 * A buffer cannot be placed on two lists at the same time.
967 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
968 static inline void __skb_queue_head(struct sk_buff_head *list,
969 struct sk_buff *newsk)
971 __skb_queue_after(list, (struct sk_buff *)list, newsk);
975 * __skb_queue_tail - queue a buffer at the list tail
977 * @newsk: buffer to queue
979 * Queue a buffer at the end of a list. This function takes no locks
980 * and you must therefore hold required locks before calling it.
982 * A buffer cannot be placed on two lists at the same time.
984 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
985 static inline void __skb_queue_tail(struct sk_buff_head *list,
986 struct sk_buff *newsk)
988 __skb_queue_before(list, (struct sk_buff *)list, newsk);
992 * remove sk_buff from list. _Must_ be called atomically, and with
995 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
996 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
998 struct sk_buff *next, *prev;
1003 skb->next = skb->prev = NULL;
1009 * __skb_dequeue - remove from the head of the queue
1010 * @list: list to dequeue from
1012 * Remove the head of the list. This function does not take any locks
1013 * so must be used with appropriate locks held only. The head item is
1014 * returned or %NULL if the list is empty.
1016 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1017 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1019 struct sk_buff *skb = skb_peek(list);
1021 __skb_unlink(skb, list);
1026 * __skb_dequeue_tail - remove from the tail of the queue
1027 * @list: list to dequeue from
1029 * Remove the tail of the list. This function does not take any locks
1030 * so must be used with appropriate locks held only. The tail item is
1031 * returned or %NULL if the list is empty.
1033 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1034 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1036 struct sk_buff *skb = skb_peek_tail(list);
1038 __skb_unlink(skb, list);
1043 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1045 return skb->data_len;
1048 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1050 return skb->len - skb->data_len;
1053 static inline int skb_pagelen(const struct sk_buff *skb)
1057 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1058 len += skb_shinfo(skb)->frags[i].size;
1059 return len + skb_headlen(skb);
1062 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1063 struct page *page, int off, int size)
1065 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1068 frag->page_offset = off;
1070 skb_shinfo(skb)->nr_frags = i + 1;
1073 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1076 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1077 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1078 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1080 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1081 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1083 return skb->head + skb->tail;
1086 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1088 skb->tail = skb->data - skb->head;
1091 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1093 skb_reset_tail_pointer(skb);
1094 skb->tail += offset;
1096 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1097 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1102 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1104 skb->tail = skb->data;
1107 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1109 skb->tail = skb->data + offset;
1112 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1115 * Add data to an sk_buff
1117 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1118 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1120 unsigned char *tmp = skb_tail_pointer(skb);
1121 SKB_LINEAR_ASSERT(skb);
1127 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1128 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1135 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1136 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1139 BUG_ON(skb->len < skb->data_len);
1140 return skb->data += len;
1143 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1145 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1147 if (len > skb_headlen(skb) &&
1148 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1151 return skb->data += len;
1154 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1156 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1159 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1161 if (likely(len <= skb_headlen(skb)))
1163 if (unlikely(len > skb->len))
1165 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1169 * skb_headroom - bytes at buffer head
1170 * @skb: buffer to check
1172 * Return the number of bytes of free space at the head of an &sk_buff.
1174 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1176 return skb->data - skb->head;
1180 * skb_tailroom - bytes at buffer end
1181 * @skb: buffer to check
1183 * Return the number of bytes of free space at the tail of an sk_buff
1185 static inline int skb_tailroom(const struct sk_buff *skb)
1187 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1191 * skb_reserve - adjust headroom
1192 * @skb: buffer to alter
1193 * @len: bytes to move
1195 * Increase the headroom of an empty &sk_buff by reducing the tail
1196 * room. This is only allowed for an empty buffer.
1198 static inline void skb_reserve(struct sk_buff *skb, int len)
1204 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1205 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1207 return skb->head + skb->transport_header;
1210 static inline void skb_reset_transport_header(struct sk_buff *skb)
1212 skb->transport_header = skb->data - skb->head;
1215 static inline void skb_set_transport_header(struct sk_buff *skb,
1218 skb_reset_transport_header(skb);
1219 skb->transport_header += offset;
1222 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1224 return skb->head + skb->network_header;
1227 static inline void skb_reset_network_header(struct sk_buff *skb)
1229 skb->network_header = skb->data - skb->head;
1232 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1234 skb_reset_network_header(skb);
1235 skb->network_header += offset;
1238 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1240 return skb->head + skb->mac_header;
1243 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1245 return skb->mac_header != ~0U;
1248 static inline void skb_reset_mac_header(struct sk_buff *skb)
1250 skb->mac_header = skb->data - skb->head;
1253 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1255 skb_reset_mac_header(skb);
1256 skb->mac_header += offset;
1259 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1261 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1263 return skb->transport_header;
1266 static inline void skb_reset_transport_header(struct sk_buff *skb)
1268 skb->transport_header = skb->data;
1271 static inline void skb_set_transport_header(struct sk_buff *skb,
1274 skb->transport_header = skb->data + offset;
1277 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1279 return skb->network_header;
1282 static inline void skb_reset_network_header(struct sk_buff *skb)
1284 skb->network_header = skb->data;
1287 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1289 skb->network_header = skb->data + offset;
1292 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1294 return skb->mac_header;
1297 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1299 return skb->mac_header != NULL;
1302 static inline void skb_reset_mac_header(struct sk_buff *skb)
1304 skb->mac_header = skb->data;
1307 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1309 skb->mac_header = skb->data + offset;
1311 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1313 static inline int skb_transport_offset(const struct sk_buff *skb)
1315 return skb_transport_header(skb) - skb->data;
1318 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1320 return skb->transport_header - skb->network_header;
1323 static inline int skb_network_offset(const struct sk_buff *skb)
1325 return skb_network_header(skb) - skb->data;
1329 * CPUs often take a performance hit when accessing unaligned memory
1330 * locations. The actual performance hit varies, it can be small if the
1331 * hardware handles it or large if we have to take an exception and fix it
1334 * Since an ethernet header is 14 bytes network drivers often end up with
1335 * the IP header at an unaligned offset. The IP header can be aligned by
1336 * shifting the start of the packet by 2 bytes. Drivers should do this
1339 * skb_reserve(NET_IP_ALIGN);
1341 * The downside to this alignment of the IP header is that the DMA is now
1342 * unaligned. On some architectures the cost of an unaligned DMA is high
1343 * and this cost outweighs the gains made by aligning the IP header.
1345 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1348 #ifndef NET_IP_ALIGN
1349 #define NET_IP_ALIGN 2
1353 * The networking layer reserves some headroom in skb data (via
1354 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1355 * the header has to grow. In the default case, if the header has to grow
1356 * 32 bytes or less we avoid the reallocation.
1358 * Unfortunately this headroom changes the DMA alignment of the resulting
1359 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1360 * on some architectures. An architecture can override this value,
1361 * perhaps setting it to a cacheline in size (since that will maintain
1362 * cacheline alignment of the DMA). It must be a power of 2.
1364 * Various parts of the networking layer expect at least 32 bytes of
1365 * headroom, you should not reduce this.
1368 #define NET_SKB_PAD 32
1371 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1373 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1375 if (unlikely(skb->data_len)) {
1380 skb_set_tail_pointer(skb, len);
1383 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1385 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1388 return ___pskb_trim(skb, len);
1389 __skb_trim(skb, len);
1393 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1395 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1399 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1400 * @skb: buffer to alter
1403 * This is identical to pskb_trim except that the caller knows that
1404 * the skb is not cloned so we should never get an error due to out-
1407 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1409 int err = pskb_trim(skb, len);
1414 * skb_orphan - orphan a buffer
1415 * @skb: buffer to orphan
1417 * If a buffer currently has an owner then we call the owner's
1418 * destructor function and make the @skb unowned. The buffer continues
1419 * to exist but is no longer charged to its former owner.
1421 static inline void skb_orphan(struct sk_buff *skb)
1423 if (skb->destructor)
1424 skb->destructor(skb);
1425 skb->destructor = NULL;
1430 * __skb_queue_purge - empty a list
1431 * @list: list to empty
1433 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1434 * the list and one reference dropped. This function does not take the
1435 * list lock and the caller must hold the relevant locks to use it.
1437 extern void skb_queue_purge(struct sk_buff_head *list);
1438 static inline void __skb_queue_purge(struct sk_buff_head *list)
1440 struct sk_buff *skb;
1441 while ((skb = __skb_dequeue(list)) != NULL)
1446 * __dev_alloc_skb - allocate an skbuff for receiving
1447 * @length: length to allocate
1448 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1450 * Allocate a new &sk_buff and assign it a usage count of one. The
1451 * buffer has unspecified headroom built in. Users should allocate
1452 * the headroom they think they need without accounting for the
1453 * built in space. The built in space is used for optimisations.
1455 * %NULL is returned if there is no free memory.
1457 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1460 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1462 skb_reserve(skb, NET_SKB_PAD);
1466 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1468 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1469 unsigned int length, gfp_t gfp_mask);
1472 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1473 * @dev: network device to receive on
1474 * @length: length to allocate
1476 * Allocate a new &sk_buff and assign it a usage count of one. The
1477 * buffer has unspecified headroom built in. Users should allocate
1478 * the headroom they think they need without accounting for the
1479 * built in space. The built in space is used for optimisations.
1481 * %NULL is returned if there is no free memory. Although this function
1482 * allocates memory it can be called from an interrupt.
1484 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1485 unsigned int length)
1487 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1490 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1493 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1494 * @dev: network device to receive on
1496 * Allocate a new page node local to the specified device.
1498 * %NULL is returned if there is no free memory.
1500 static inline struct page *netdev_alloc_page(struct net_device *dev)
1502 return __netdev_alloc_page(dev, GFP_ATOMIC);
1505 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1511 * skb_clone_writable - is the header of a clone writable
1512 * @skb: buffer to check
1513 * @len: length up to which to write
1515 * Returns true if modifying the header part of the cloned buffer
1516 * does not requires the data to be copied.
1518 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1520 return !skb_header_cloned(skb) &&
1521 skb_headroom(skb) + len <= skb->hdr_len;
1524 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1529 if (headroom < NET_SKB_PAD)
1530 headroom = NET_SKB_PAD;
1531 if (headroom > skb_headroom(skb))
1532 delta = headroom - skb_headroom(skb);
1534 if (delta || cloned)
1535 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1541 * skb_cow - copy header of skb when it is required
1542 * @skb: buffer to cow
1543 * @headroom: needed headroom
1545 * If the skb passed lacks sufficient headroom or its data part
1546 * is shared, data is reallocated. If reallocation fails, an error
1547 * is returned and original skb is not changed.
1549 * The result is skb with writable area skb->head...skb->tail
1550 * and at least @headroom of space at head.
1552 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1554 return __skb_cow(skb, headroom, skb_cloned(skb));
1558 * skb_cow_head - skb_cow but only making the head writable
1559 * @skb: buffer to cow
1560 * @headroom: needed headroom
1562 * This function is identical to skb_cow except that we replace the
1563 * skb_cloned check by skb_header_cloned. It should be used when
1564 * you only need to push on some header and do not need to modify
1567 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1569 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1573 * skb_padto - pad an skbuff up to a minimal size
1574 * @skb: buffer to pad
1575 * @len: minimal length
1577 * Pads up a buffer to ensure the trailing bytes exist and are
1578 * blanked. If the buffer already contains sufficient data it
1579 * is untouched. Otherwise it is extended. Returns zero on
1580 * success. The skb is freed on error.
1583 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1585 unsigned int size = skb->len;
1586 if (likely(size >= len))
1588 return skb_pad(skb, len - size);
1591 static inline int skb_add_data(struct sk_buff *skb,
1592 char __user *from, int copy)
1594 const int off = skb->len;
1596 if (skb->ip_summed == CHECKSUM_NONE) {
1598 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1601 skb->csum = csum_block_add(skb->csum, csum, off);
1604 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1607 __skb_trim(skb, off);
1611 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1612 struct page *page, int off)
1615 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1617 return page == frag->page &&
1618 off == frag->page_offset + frag->size;
1623 static inline int __skb_linearize(struct sk_buff *skb)
1625 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1629 * skb_linearize - convert paged skb to linear one
1630 * @skb: buffer to linarize
1632 * If there is no free memory -ENOMEM is returned, otherwise zero
1633 * is returned and the old skb data released.
1635 static inline int skb_linearize(struct sk_buff *skb)
1637 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1641 * skb_linearize_cow - make sure skb is linear and writable
1642 * @skb: buffer to process
1644 * If there is no free memory -ENOMEM is returned, otherwise zero
1645 * is returned and the old skb data released.
1647 static inline int skb_linearize_cow(struct sk_buff *skb)
1649 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1650 __skb_linearize(skb) : 0;
1654 * skb_postpull_rcsum - update checksum for received skb after pull
1655 * @skb: buffer to update
1656 * @start: start of data before pull
1657 * @len: length of data pulled
1659 * After doing a pull on a received packet, you need to call this to
1660 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1661 * CHECKSUM_NONE so that it can be recomputed from scratch.
1664 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1665 const void *start, unsigned int len)
1667 if (skb->ip_summed == CHECKSUM_COMPLETE)
1668 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1671 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1674 * pskb_trim_rcsum - trim received skb and update checksum
1675 * @skb: buffer to trim
1678 * This is exactly the same as pskb_trim except that it ensures the
1679 * checksum of received packets are still valid after the operation.
1682 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1684 if (likely(len >= skb->len))
1686 if (skb->ip_summed == CHECKSUM_COMPLETE)
1687 skb->ip_summed = CHECKSUM_NONE;
1688 return __pskb_trim(skb, len);
1691 #define skb_queue_walk(queue, skb) \
1692 for (skb = (queue)->next; \
1693 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1696 #define skb_queue_walk_safe(queue, skb, tmp) \
1697 for (skb = (queue)->next, tmp = skb->next; \
1698 skb != (struct sk_buff *)(queue); \
1699 skb = tmp, tmp = skb->next)
1701 #define skb_queue_walk_from(queue, skb) \
1702 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1705 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1706 for (tmp = skb->next; \
1707 skb != (struct sk_buff *)(queue); \
1708 skb = tmp, tmp = skb->next)
1710 #define skb_queue_reverse_walk(queue, skb) \
1711 for (skb = (queue)->prev; \
1712 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1716 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1717 int *peeked, int *err);
1718 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1719 int noblock, int *err);
1720 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1721 struct poll_table_struct *wait);
1722 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1723 int offset, struct iovec *to,
1725 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1728 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1730 const struct iovec *from,
1733 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
1735 const struct iovec *to,
1738 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1739 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1740 unsigned int flags);
1741 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1742 int len, __wsum csum);
1743 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1745 extern int skb_store_bits(struct sk_buff *skb, int offset,
1746 const void *from, int len);
1747 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1748 int offset, u8 *to, int len,
1750 extern int skb_splice_bits(struct sk_buff *skb,
1751 unsigned int offset,
1752 struct pipe_inode_info *pipe,
1754 unsigned int flags);
1755 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1756 extern void skb_split(struct sk_buff *skb,
1757 struct sk_buff *skb1, const u32 len);
1758 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1761 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1763 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1764 int len, void *buffer)
1766 int hlen = skb_headlen(skb);
1768 if (hlen - offset >= len)
1769 return skb->data + offset;
1771 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1777 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1779 const unsigned int len)
1781 memcpy(to, skb->data, len);
1784 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1785 const int offset, void *to,
1786 const unsigned int len)
1788 memcpy(to, skb->data + offset, len);
1791 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1793 const unsigned int len)
1795 memcpy(skb->data, from, len);
1798 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1801 const unsigned int len)
1803 memcpy(skb->data + offset, from, len);
1806 extern void skb_init(void);
1808 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1814 * skb_get_timestamp - get timestamp from a skb
1815 * @skb: skb to get stamp from
1816 * @stamp: pointer to struct timeval to store stamp in
1818 * Timestamps are stored in the skb as offsets to a base timestamp.
1819 * This function converts the offset back to a struct timeval and stores
1822 static inline void skb_get_timestamp(const struct sk_buff *skb,
1823 struct timeval *stamp)
1825 *stamp = ktime_to_timeval(skb->tstamp);
1828 static inline void skb_get_timestampns(const struct sk_buff *skb,
1829 struct timespec *stamp)
1831 *stamp = ktime_to_timespec(skb->tstamp);
1834 static inline void __net_timestamp(struct sk_buff *skb)
1836 skb->tstamp = ktime_get_real();
1839 static inline ktime_t net_timedelta(ktime_t t)
1841 return ktime_sub(ktime_get_real(), t);
1844 static inline ktime_t net_invalid_timestamp(void)
1846 return ktime_set(0, 0);
1850 * skb_tstamp_tx - queue clone of skb with send time stamps
1851 * @orig_skb: the original outgoing packet
1852 * @hwtstamps: hardware time stamps, may be NULL if not available
1854 * If the skb has a socket associated, then this function clones the
1855 * skb (thus sharing the actual data and optional structures), stores
1856 * the optional hardware time stamping information (if non NULL) or
1857 * generates a software time stamp (otherwise), then queues the clone
1858 * to the error queue of the socket. Errors are silently ignored.
1860 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1861 struct skb_shared_hwtstamps *hwtstamps);
1863 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1864 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1866 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1868 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1872 * skb_checksum_complete - Calculate checksum of an entire packet
1873 * @skb: packet to process
1875 * This function calculates the checksum over the entire packet plus
1876 * the value of skb->csum. The latter can be used to supply the
1877 * checksum of a pseudo header as used by TCP/UDP. It returns the
1880 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1881 * this function can be used to verify that checksum on received
1882 * packets. In that case the function should return zero if the
1883 * checksum is correct. In particular, this function will return zero
1884 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1885 * hardware has already verified the correctness of the checksum.
1887 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1889 return skb_csum_unnecessary(skb) ?
1890 0 : __skb_checksum_complete(skb);
1893 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1894 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1895 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1897 if (nfct && atomic_dec_and_test(&nfct->use))
1898 nf_conntrack_destroy(nfct);
1900 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1903 atomic_inc(&nfct->use);
1905 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1908 atomic_inc(&skb->users);
1910 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1916 #ifdef CONFIG_BRIDGE_NETFILTER
1917 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1919 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1922 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1925 atomic_inc(&nf_bridge->use);
1927 #endif /* CONFIG_BRIDGE_NETFILTER */
1928 static inline void nf_reset(struct sk_buff *skb)
1930 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1931 nf_conntrack_put(skb->nfct);
1933 nf_conntrack_put_reasm(skb->nfct_reasm);
1934 skb->nfct_reasm = NULL;
1936 #ifdef CONFIG_BRIDGE_NETFILTER
1937 nf_bridge_put(skb->nf_bridge);
1938 skb->nf_bridge = NULL;
1942 /* Note: This doesn't put any conntrack and bridge info in dst. */
1943 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1945 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1946 dst->nfct = src->nfct;
1947 nf_conntrack_get(src->nfct);
1948 dst->nfctinfo = src->nfctinfo;
1949 dst->nfct_reasm = src->nfct_reasm;
1950 nf_conntrack_get_reasm(src->nfct_reasm);
1952 #ifdef CONFIG_BRIDGE_NETFILTER
1953 dst->nf_bridge = src->nf_bridge;
1954 nf_bridge_get(src->nf_bridge);
1958 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1960 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1961 nf_conntrack_put(dst->nfct);
1962 nf_conntrack_put_reasm(dst->nfct_reasm);
1964 #ifdef CONFIG_BRIDGE_NETFILTER
1965 nf_bridge_put(dst->nf_bridge);
1967 __nf_copy(dst, src);
1970 #ifdef CONFIG_NETWORK_SECMARK
1971 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1973 to->secmark = from->secmark;
1976 static inline void skb_init_secmark(struct sk_buff *skb)
1981 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1984 static inline void skb_init_secmark(struct sk_buff *skb)
1988 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1990 skb->queue_mapping = queue_mapping;
1993 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
1995 return skb->queue_mapping;
1998 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2000 to->queue_mapping = from->queue_mapping;
2003 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2005 skb->queue_mapping = rx_queue + 1;
2008 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2010 return skb->queue_mapping - 1;
2013 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2015 return (skb->queue_mapping != 0);
2018 extern u16 skb_tx_hash(const struct net_device *dev,
2019 const struct sk_buff *skb);
2022 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2027 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2033 static inline int skb_is_gso(const struct sk_buff *skb)
2035 return skb_shinfo(skb)->gso_size;
2038 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2040 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2043 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2045 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2047 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2048 * wanted then gso_type will be set. */
2049 struct skb_shared_info *shinfo = skb_shinfo(skb);
2050 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2051 __skb_warn_lro_forwarding(skb);
2057 static inline void skb_forward_csum(struct sk_buff *skb)
2059 /* Unfortunately we don't support this one. Any brave souls? */
2060 if (skb->ip_summed == CHECKSUM_COMPLETE)
2061 skb->ip_summed = CHECKSUM_NONE;
2064 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2065 #endif /* __KERNEL__ */
2066 #endif /* _LINUX_SKBUFF_H */