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
172 * These flags are attached to packets as part of the
173 * &skb_shared_info. Use skb_tx() to get a pointer.
175 union skb_shared_tx {
184 /* This data is invariant across clones and lives at
185 * the end of the header data, ie. at skb->end.
187 struct skb_shared_info {
189 unsigned short nr_frags;
190 unsigned short gso_size;
191 /* Warning: this field is not always filled in (UFO)! */
192 unsigned short gso_segs;
193 unsigned short gso_type;
195 union skb_shared_tx tx_flags;
196 #ifdef CONFIG_HAS_DMA
197 unsigned int num_dma_maps;
199 struct sk_buff *frag_list;
200 struct skb_shared_hwtstamps hwtstamps;
201 skb_frag_t frags[MAX_SKB_FRAGS];
202 #ifdef CONFIG_HAS_DMA
203 dma_addr_t dma_maps[MAX_SKB_FRAGS + 1];
207 /* We divide dataref into two halves. The higher 16 bits hold references
208 * to the payload part of skb->data. The lower 16 bits hold references to
209 * the entire skb->data. A clone of a headerless skb holds the length of
210 * the header in skb->hdr_len.
212 * All users must obey the rule that the skb->data reference count must be
213 * greater than or equal to the payload reference count.
215 * Holding a reference to the payload part means that the user does not
216 * care about modifications to the header part of skb->data.
218 #define SKB_DATAREF_SHIFT 16
219 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
223 SKB_FCLONE_UNAVAILABLE,
229 SKB_GSO_TCPV4 = 1 << 0,
230 SKB_GSO_UDP = 1 << 1,
232 /* This indicates the skb is from an untrusted source. */
233 SKB_GSO_DODGY = 1 << 2,
235 /* This indicates the tcp segment has CWR set. */
236 SKB_GSO_TCP_ECN = 1 << 3,
238 SKB_GSO_TCPV6 = 1 << 4,
240 SKB_GSO_FCOE = 1 << 5,
243 #if BITS_PER_LONG > 32
244 #define NET_SKBUFF_DATA_USES_OFFSET 1
247 #ifdef NET_SKBUFF_DATA_USES_OFFSET
248 typedef unsigned int sk_buff_data_t;
250 typedef unsigned char *sk_buff_data_t;
254 * struct sk_buff - socket buffer
255 * @next: Next buffer in list
256 * @prev: Previous buffer in list
257 * @sk: Socket we are owned by
258 * @tstamp: Time we arrived
259 * @dev: Device we arrived on/are leaving by
260 * @transport_header: Transport layer header
261 * @network_header: Network layer header
262 * @mac_header: Link layer header
263 * @dst: destination entry
264 * @sp: the security path, used for xfrm
265 * @cb: Control buffer. Free for use by every layer. Put private vars here
266 * @len: Length of actual data
267 * @data_len: Data length
268 * @mac_len: Length of link layer header
269 * @hdr_len: writable header length of cloned skb
270 * @csum: Checksum (must include start/offset pair)
271 * @csum_start: Offset from skb->head where checksumming should start
272 * @csum_offset: Offset from csum_start where checksum should be stored
273 * @local_df: allow local fragmentation
274 * @cloned: Head may be cloned (check refcnt to be sure)
275 * @nohdr: Payload reference only, must not modify header
276 * @pkt_type: Packet class
277 * @fclone: skbuff clone status
278 * @ip_summed: Driver fed us an IP checksum
279 * @priority: Packet queueing priority
280 * @users: User count - see {datagram,tcp}.c
281 * @protocol: Packet protocol from driver
282 * @truesize: Buffer size
283 * @head: Head of buffer
284 * @data: Data head pointer
285 * @tail: Tail pointer
287 * @destructor: Destruct function
288 * @mark: Generic packet mark
289 * @nfct: Associated connection, if any
290 * @ipvs_property: skbuff is owned by ipvs
291 * @peeked: this packet has been seen already, so stats have been
292 * done for it, don't do them again
293 * @nf_trace: netfilter packet trace flag
294 * @nfctinfo: Relationship of this skb to the connection
295 * @nfct_reasm: netfilter conntrack re-assembly pointer
296 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
297 * @iif: ifindex of device we arrived on
298 * @queue_mapping: Queue mapping for multiqueue devices
299 * @tc_index: Traffic control index
300 * @tc_verd: traffic control verdict
301 * @ndisc_nodetype: router type (from link layer)
302 * @do_not_encrypt: set to prevent encryption of this frame
303 * @requeue: set to indicate that the wireless core should attempt
304 * a software retry on this frame if we failed to
305 * receive an ACK for it
306 * @dma_cookie: a cookie to one of several possible DMA operations
307 * done by skb DMA functions
308 * @secmark: security marking
309 * @vlan_tci: vlan tag control information
313 /* These two members must be first. */
314 struct sk_buff *next;
315 struct sk_buff *prev;
319 struct net_device *dev;
322 struct dst_entry *dst;
323 struct rtable *rtable;
329 * This is the control buffer. It is free to use for every
330 * layer. Please put your private variables there. If you
331 * want to keep them across layers you have to do a skb_clone()
332 * first. This is owned by whoever has the skb queued ATM.
360 void (*destructor)(struct sk_buff *skb);
361 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
362 struct nf_conntrack *nfct;
363 struct sk_buff *nfct_reasm;
365 #ifdef CONFIG_BRIDGE_NETFILTER
366 struct nf_bridge_info *nf_bridge;
371 #ifdef CONFIG_NET_SCHED
372 __u16 tc_index; /* traffic control index */
373 #ifdef CONFIG_NET_CLS_ACT
374 __u16 tc_verd; /* traffic control verdict */
377 #ifdef CONFIG_IPV6_NDISC_NODETYPE
378 __u8 ndisc_nodetype:2;
380 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
381 __u8 do_not_encrypt:1;
384 /* 0/13/14 bit hole */
386 #ifdef CONFIG_NET_DMA
387 dma_cookie_t dma_cookie;
389 #ifdef CONFIG_NETWORK_SECMARK
397 sk_buff_data_t transport_header;
398 sk_buff_data_t network_header;
399 sk_buff_data_t mac_header;
400 /* These elements must be at the end, see alloc_skb() for details. */
405 unsigned int truesize;
411 * Handling routines are only of interest to the kernel
413 #include <linux/slab.h>
415 #include <asm/system.h>
417 #ifdef CONFIG_HAS_DMA
418 #include <linux/dma-mapping.h>
419 extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
420 enum dma_data_direction dir);
421 extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
422 enum dma_data_direction dir);
425 extern void kfree_skb(struct sk_buff *skb);
426 extern void consume_skb(struct sk_buff *skb);
427 extern void __kfree_skb(struct sk_buff *skb);
428 extern struct sk_buff *__alloc_skb(unsigned int size,
429 gfp_t priority, int fclone, int node);
430 static inline struct sk_buff *alloc_skb(unsigned int size,
433 return __alloc_skb(size, priority, 0, -1);
436 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
439 return __alloc_skb(size, priority, 1, -1);
442 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
444 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
445 extern struct sk_buff *skb_clone(struct sk_buff *skb,
447 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
449 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
451 extern int pskb_expand_head(struct sk_buff *skb,
452 int nhead, int ntail,
454 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
455 unsigned int headroom);
456 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
457 int newheadroom, int newtailroom,
459 extern int skb_to_sgvec(struct sk_buff *skb,
460 struct scatterlist *sg, int offset,
462 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
463 struct sk_buff **trailer);
464 extern int skb_pad(struct sk_buff *skb, int pad);
465 #define dev_kfree_skb(a) consume_skb(a)
466 #define dev_consume_skb(a) kfree_skb_clean(a)
467 extern void skb_over_panic(struct sk_buff *skb, int len,
469 extern void skb_under_panic(struct sk_buff *skb, int len,
472 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
473 int getfrag(void *from, char *to, int offset,
474 int len,int odd, struct sk_buff *skb),
475 void *from, int length);
482 __u32 stepped_offset;
483 struct sk_buff *root_skb;
484 struct sk_buff *cur_skb;
488 extern void skb_prepare_seq_read(struct sk_buff *skb,
489 unsigned int from, unsigned int to,
490 struct skb_seq_state *st);
491 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
492 struct skb_seq_state *st);
493 extern void skb_abort_seq_read(struct skb_seq_state *st);
495 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
496 unsigned int to, struct ts_config *config,
497 struct ts_state *state);
499 #ifdef NET_SKBUFF_DATA_USES_OFFSET
500 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
502 return skb->head + skb->end;
505 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
512 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
514 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
516 return &skb_shinfo(skb)->hwtstamps;
519 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
521 return &skb_shinfo(skb)->tx_flags;
525 * skb_queue_empty - check if a queue is empty
528 * Returns true if the queue is empty, false otherwise.
530 static inline int skb_queue_empty(const struct sk_buff_head *list)
532 return list->next == (struct sk_buff *)list;
536 * skb_queue_is_last - check if skb is the last entry in the queue
540 * Returns true if @skb is the last buffer on the list.
542 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
543 const struct sk_buff *skb)
545 return (skb->next == (struct sk_buff *) list);
549 * skb_queue_is_first - check if skb is the first entry in the queue
553 * Returns true if @skb is the first buffer on the list.
555 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
556 const struct sk_buff *skb)
558 return (skb->prev == (struct sk_buff *) list);
562 * skb_queue_next - return the next packet in the queue
564 * @skb: current buffer
566 * Return the next packet in @list after @skb. It is only valid to
567 * call this if skb_queue_is_last() evaluates to false.
569 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
570 const struct sk_buff *skb)
572 /* This BUG_ON may seem severe, but if we just return then we
573 * are going to dereference garbage.
575 BUG_ON(skb_queue_is_last(list, skb));
580 * skb_queue_prev - return the prev packet in the queue
582 * @skb: current buffer
584 * Return the prev packet in @list before @skb. It is only valid to
585 * call this if skb_queue_is_first() evaluates to false.
587 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
588 const struct sk_buff *skb)
590 /* This BUG_ON may seem severe, but if we just return then we
591 * are going to dereference garbage.
593 BUG_ON(skb_queue_is_first(list, skb));
598 * skb_get - reference buffer
599 * @skb: buffer to reference
601 * Makes another reference to a socket buffer and returns a pointer
604 static inline struct sk_buff *skb_get(struct sk_buff *skb)
606 atomic_inc(&skb->users);
611 * If users == 1, we are the only owner and are can avoid redundant
616 * skb_cloned - is the buffer a clone
617 * @skb: buffer to check
619 * Returns true if the buffer was generated with skb_clone() and is
620 * one of multiple shared copies of the buffer. Cloned buffers are
621 * shared data so must not be written to under normal circumstances.
623 static inline int skb_cloned(const struct sk_buff *skb)
625 return skb->cloned &&
626 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
630 * skb_header_cloned - is the header a clone
631 * @skb: buffer to check
633 * Returns true if modifying the header part of the buffer requires
634 * the data to be copied.
636 static inline int skb_header_cloned(const struct sk_buff *skb)
643 dataref = atomic_read(&skb_shinfo(skb)->dataref);
644 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
649 * skb_header_release - release reference to header
650 * @skb: buffer to operate on
652 * Drop a reference to the header part of the buffer. This is done
653 * by acquiring a payload reference. You must not read from the header
654 * part of skb->data after this.
656 static inline void skb_header_release(struct sk_buff *skb)
660 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
664 * skb_shared - is the buffer shared
665 * @skb: buffer to check
667 * Returns true if more than one person has a reference to this
670 static inline int skb_shared(const struct sk_buff *skb)
672 return atomic_read(&skb->users) != 1;
676 * skb_share_check - check if buffer is shared and if so clone it
677 * @skb: buffer to check
678 * @pri: priority for memory allocation
680 * If the buffer is shared the buffer is cloned and the old copy
681 * drops a reference. A new clone with a single reference is returned.
682 * If the buffer is not shared the original buffer is returned. When
683 * being called from interrupt status or with spinlocks held pri must
686 * NULL is returned on a memory allocation failure.
688 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
691 might_sleep_if(pri & __GFP_WAIT);
692 if (skb_shared(skb)) {
693 struct sk_buff *nskb = skb_clone(skb, pri);
701 * Copy shared buffers into a new sk_buff. We effectively do COW on
702 * packets to handle cases where we have a local reader and forward
703 * and a couple of other messy ones. The normal one is tcpdumping
704 * a packet thats being forwarded.
708 * skb_unshare - make a copy of a shared buffer
709 * @skb: buffer to check
710 * @pri: priority for memory allocation
712 * If the socket buffer is a clone then this function creates a new
713 * copy of the data, drops a reference count on the old copy and returns
714 * the new copy with the reference count at 1. If the buffer is not a clone
715 * the original buffer is returned. When called with a spinlock held or
716 * from interrupt state @pri must be %GFP_ATOMIC
718 * %NULL is returned on a memory allocation failure.
720 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
723 might_sleep_if(pri & __GFP_WAIT);
724 if (skb_cloned(skb)) {
725 struct sk_buff *nskb = skb_copy(skb, pri);
726 kfree_skb(skb); /* Free our shared copy */
734 * @list_: list to peek at
736 * Peek an &sk_buff. Unlike most other operations you _MUST_
737 * be careful with this one. A peek leaves the buffer on the
738 * list and someone else may run off with it. You must hold
739 * the appropriate locks or have a private queue to do this.
741 * Returns %NULL for an empty list or a pointer to the head element.
742 * The reference count is not incremented and the reference is therefore
743 * volatile. Use with caution.
745 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
747 struct sk_buff *list = ((struct sk_buff *)list_)->next;
748 if (list == (struct sk_buff *)list_)
755 * @list_: list to peek at
757 * Peek an &sk_buff. Unlike most other operations you _MUST_
758 * be careful with this one. A peek leaves the buffer on the
759 * list and someone else may run off with it. You must hold
760 * the appropriate locks or have a private queue to do this.
762 * Returns %NULL for an empty list or a pointer to the tail element.
763 * The reference count is not incremented and the reference is therefore
764 * volatile. Use with caution.
766 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
768 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
769 if (list == (struct sk_buff *)list_)
775 * skb_queue_len - get queue length
776 * @list_: list to measure
778 * Return the length of an &sk_buff queue.
780 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
786 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
787 * @list: queue to initialize
789 * This initializes only the list and queue length aspects of
790 * an sk_buff_head object. This allows to initialize the list
791 * aspects of an sk_buff_head without reinitializing things like
792 * the spinlock. It can also be used for on-stack sk_buff_head
793 * objects where the spinlock is known to not be used.
795 static inline void __skb_queue_head_init(struct sk_buff_head *list)
797 list->prev = list->next = (struct sk_buff *)list;
802 * This function creates a split out lock class for each invocation;
803 * this is needed for now since a whole lot of users of the skb-queue
804 * infrastructure in drivers have different locking usage (in hardirq)
805 * than the networking core (in softirq only). In the long run either the
806 * network layer or drivers should need annotation to consolidate the
807 * main types of usage into 3 classes.
809 static inline void skb_queue_head_init(struct sk_buff_head *list)
811 spin_lock_init(&list->lock);
812 __skb_queue_head_init(list);
815 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
816 struct lock_class_key *class)
818 skb_queue_head_init(list);
819 lockdep_set_class(&list->lock, class);
823 * Insert an sk_buff on a list.
825 * The "__skb_xxxx()" functions are the non-atomic ones that
826 * can only be called with interrupts disabled.
828 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
829 static inline void __skb_insert(struct sk_buff *newsk,
830 struct sk_buff *prev, struct sk_buff *next,
831 struct sk_buff_head *list)
835 next->prev = prev->next = newsk;
839 static inline void __skb_queue_splice(const struct sk_buff_head *list,
840 struct sk_buff *prev,
841 struct sk_buff *next)
843 struct sk_buff *first = list->next;
844 struct sk_buff *last = list->prev;
854 * skb_queue_splice - join two skb lists, this is designed for stacks
855 * @list: the new list to add
856 * @head: the place to add it in the first list
858 static inline void skb_queue_splice(const struct sk_buff_head *list,
859 struct sk_buff_head *head)
861 if (!skb_queue_empty(list)) {
862 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
863 head->qlen += list->qlen;
868 * skb_queue_splice - join two skb lists and reinitialise the emptied list
869 * @list: the new list to add
870 * @head: the place to add it in the first list
872 * The list at @list is reinitialised
874 static inline void skb_queue_splice_init(struct sk_buff_head *list,
875 struct sk_buff_head *head)
877 if (!skb_queue_empty(list)) {
878 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
879 head->qlen += list->qlen;
880 __skb_queue_head_init(list);
885 * skb_queue_splice_tail - join two skb lists, each list being a queue
886 * @list: the new list to add
887 * @head: the place to add it in the first list
889 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
890 struct sk_buff_head *head)
892 if (!skb_queue_empty(list)) {
893 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
894 head->qlen += list->qlen;
899 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
900 * @list: the new list to add
901 * @head: the place to add it in the first list
903 * Each of the lists is a queue.
904 * The list at @list is reinitialised
906 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
907 struct sk_buff_head *head)
909 if (!skb_queue_empty(list)) {
910 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
911 head->qlen += list->qlen;
912 __skb_queue_head_init(list);
917 * __skb_queue_after - queue a buffer at the list head
919 * @prev: place after this buffer
920 * @newsk: buffer to queue
922 * Queue a buffer int the middle of a list. This function takes no locks
923 * and you must therefore hold required locks before calling it.
925 * A buffer cannot be placed on two lists at the same time.
927 static inline void __skb_queue_after(struct sk_buff_head *list,
928 struct sk_buff *prev,
929 struct sk_buff *newsk)
931 __skb_insert(newsk, prev, prev->next, list);
934 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
935 struct sk_buff_head *list);
937 static inline void __skb_queue_before(struct sk_buff_head *list,
938 struct sk_buff *next,
939 struct sk_buff *newsk)
941 __skb_insert(newsk, next->prev, next, list);
945 * __skb_queue_head - queue a buffer at the list head
947 * @newsk: buffer to queue
949 * Queue a buffer at the start of a list. This function takes no locks
950 * and you must therefore hold required locks before calling it.
952 * A buffer cannot be placed on two lists at the same time.
954 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
955 static inline void __skb_queue_head(struct sk_buff_head *list,
956 struct sk_buff *newsk)
958 __skb_queue_after(list, (struct sk_buff *)list, newsk);
962 * __skb_queue_tail - queue a buffer at the list tail
964 * @newsk: buffer to queue
966 * Queue a buffer at the end of a list. This function takes no locks
967 * and you must therefore hold required locks before calling it.
969 * A buffer cannot be placed on two lists at the same time.
971 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
972 static inline void __skb_queue_tail(struct sk_buff_head *list,
973 struct sk_buff *newsk)
975 __skb_queue_before(list, (struct sk_buff *)list, newsk);
979 * remove sk_buff from list. _Must_ be called atomically, and with
982 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
983 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
985 struct sk_buff *next, *prev;
990 skb->next = skb->prev = NULL;
996 * __skb_dequeue - remove from the head of the queue
997 * @list: list to dequeue from
999 * Remove the head of the list. This function does not take any locks
1000 * so must be used with appropriate locks held only. The head item is
1001 * returned or %NULL if the list is empty.
1003 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1004 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1006 struct sk_buff *skb = skb_peek(list);
1008 __skb_unlink(skb, list);
1013 * __skb_dequeue_tail - remove from the tail of the queue
1014 * @list: list to dequeue from
1016 * Remove the tail of the list. This function does not take any locks
1017 * so must be used with appropriate locks held only. The tail item is
1018 * returned or %NULL if the list is empty.
1020 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1021 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1023 struct sk_buff *skb = skb_peek_tail(list);
1025 __skb_unlink(skb, list);
1030 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1032 return skb->data_len;
1035 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1037 return skb->len - skb->data_len;
1040 static inline int skb_pagelen(const struct sk_buff *skb)
1044 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1045 len += skb_shinfo(skb)->frags[i].size;
1046 return len + skb_headlen(skb);
1049 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1050 struct page *page, int off, int size)
1052 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1055 frag->page_offset = off;
1057 skb_shinfo(skb)->nr_frags = i + 1;
1060 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1063 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1064 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1065 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1067 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1068 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1070 return skb->head + skb->tail;
1073 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1075 skb->tail = skb->data - skb->head;
1078 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1080 skb_reset_tail_pointer(skb);
1081 skb->tail += offset;
1083 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1084 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1089 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1091 skb->tail = skb->data;
1094 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1096 skb->tail = skb->data + offset;
1099 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1102 * Add data to an sk_buff
1104 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1105 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1107 unsigned char *tmp = skb_tail_pointer(skb);
1108 SKB_LINEAR_ASSERT(skb);
1114 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1115 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1122 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1123 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1126 BUG_ON(skb->len < skb->data_len);
1127 return skb->data += len;
1130 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1132 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1134 if (len > skb_headlen(skb) &&
1135 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1138 return skb->data += len;
1141 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1143 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1146 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1148 if (likely(len <= skb_headlen(skb)))
1150 if (unlikely(len > skb->len))
1152 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1156 * skb_headroom - bytes at buffer head
1157 * @skb: buffer to check
1159 * Return the number of bytes of free space at the head of an &sk_buff.
1161 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1163 return skb->data - skb->head;
1167 * skb_tailroom - bytes at buffer end
1168 * @skb: buffer to check
1170 * Return the number of bytes of free space at the tail of an sk_buff
1172 static inline int skb_tailroom(const struct sk_buff *skb)
1174 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1178 * skb_reserve - adjust headroom
1179 * @skb: buffer to alter
1180 * @len: bytes to move
1182 * Increase the headroom of an empty &sk_buff by reducing the tail
1183 * room. This is only allowed for an empty buffer.
1185 static inline void skb_reserve(struct sk_buff *skb, int len)
1191 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1192 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1194 return skb->head + skb->transport_header;
1197 static inline void skb_reset_transport_header(struct sk_buff *skb)
1199 skb->transport_header = skb->data - skb->head;
1202 static inline void skb_set_transport_header(struct sk_buff *skb,
1205 skb_reset_transport_header(skb);
1206 skb->transport_header += offset;
1209 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1211 return skb->head + skb->network_header;
1214 static inline void skb_reset_network_header(struct sk_buff *skb)
1216 skb->network_header = skb->data - skb->head;
1219 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1221 skb_reset_network_header(skb);
1222 skb->network_header += offset;
1225 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1227 return skb->head + skb->mac_header;
1230 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1232 return skb->mac_header != ~0U;
1235 static inline void skb_reset_mac_header(struct sk_buff *skb)
1237 skb->mac_header = skb->data - skb->head;
1240 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1242 skb_reset_mac_header(skb);
1243 skb->mac_header += offset;
1246 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1248 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1250 return skb->transport_header;
1253 static inline void skb_reset_transport_header(struct sk_buff *skb)
1255 skb->transport_header = skb->data;
1258 static inline void skb_set_transport_header(struct sk_buff *skb,
1261 skb->transport_header = skb->data + offset;
1264 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1266 return skb->network_header;
1269 static inline void skb_reset_network_header(struct sk_buff *skb)
1271 skb->network_header = skb->data;
1274 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1276 skb->network_header = skb->data + offset;
1279 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1281 return skb->mac_header;
1284 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1286 return skb->mac_header != NULL;
1289 static inline void skb_reset_mac_header(struct sk_buff *skb)
1291 skb->mac_header = skb->data;
1294 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1296 skb->mac_header = skb->data + offset;
1298 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1300 static inline int skb_transport_offset(const struct sk_buff *skb)
1302 return skb_transport_header(skb) - skb->data;
1305 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1307 return skb->transport_header - skb->network_header;
1310 static inline int skb_network_offset(const struct sk_buff *skb)
1312 return skb_network_header(skb) - skb->data;
1316 * CPUs often take a performance hit when accessing unaligned memory
1317 * locations. The actual performance hit varies, it can be small if the
1318 * hardware handles it or large if we have to take an exception and fix it
1321 * Since an ethernet header is 14 bytes network drivers often end up with
1322 * the IP header at an unaligned offset. The IP header can be aligned by
1323 * shifting the start of the packet by 2 bytes. Drivers should do this
1326 * skb_reserve(NET_IP_ALIGN);
1328 * The downside to this alignment of the IP header is that the DMA is now
1329 * unaligned. On some architectures the cost of an unaligned DMA is high
1330 * and this cost outweighs the gains made by aligning the IP header.
1332 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1335 #ifndef NET_IP_ALIGN
1336 #define NET_IP_ALIGN 2
1340 * The networking layer reserves some headroom in skb data (via
1341 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1342 * the header has to grow. In the default case, if the header has to grow
1343 * 32 bytes or less we avoid the reallocation.
1345 * Unfortunately this headroom changes the DMA alignment of the resulting
1346 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1347 * on some architectures. An architecture can override this value,
1348 * perhaps setting it to a cacheline in size (since that will maintain
1349 * cacheline alignment of the DMA). It must be a power of 2.
1351 * Various parts of the networking layer expect at least 32 bytes of
1352 * headroom, you should not reduce this.
1355 #define NET_SKB_PAD 32
1358 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1360 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1362 if (unlikely(skb->data_len)) {
1367 skb_set_tail_pointer(skb, len);
1370 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1372 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1375 return ___pskb_trim(skb, len);
1376 __skb_trim(skb, len);
1380 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1382 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1386 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1387 * @skb: buffer to alter
1390 * This is identical to pskb_trim except that the caller knows that
1391 * the skb is not cloned so we should never get an error due to out-
1394 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1396 int err = pskb_trim(skb, len);
1401 * skb_orphan - orphan a buffer
1402 * @skb: buffer to orphan
1404 * If a buffer currently has an owner then we call the owner's
1405 * destructor function and make the @skb unowned. The buffer continues
1406 * to exist but is no longer charged to its former owner.
1408 static inline void skb_orphan(struct sk_buff *skb)
1410 if (skb->destructor)
1411 skb->destructor(skb);
1412 skb->destructor = NULL;
1417 * __skb_queue_purge - empty a list
1418 * @list: list to empty
1420 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1421 * the list and one reference dropped. This function does not take the
1422 * list lock and the caller must hold the relevant locks to use it.
1424 extern void skb_queue_purge(struct sk_buff_head *list);
1425 static inline void __skb_queue_purge(struct sk_buff_head *list)
1427 struct sk_buff *skb;
1428 while ((skb = __skb_dequeue(list)) != NULL)
1433 * __dev_alloc_skb - allocate an skbuff for receiving
1434 * @length: length to allocate
1435 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1437 * Allocate a new &sk_buff and assign it a usage count of one. The
1438 * buffer has unspecified headroom built in. Users should allocate
1439 * the headroom they think they need without accounting for the
1440 * built in space. The built in space is used for optimisations.
1442 * %NULL is returned if there is no free memory.
1444 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1447 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1449 skb_reserve(skb, NET_SKB_PAD);
1453 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1455 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1456 unsigned int length, gfp_t gfp_mask);
1459 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1460 * @dev: network device to receive on
1461 * @length: length to allocate
1463 * Allocate a new &sk_buff and assign it a usage count of one. The
1464 * buffer has unspecified headroom built in. Users should allocate
1465 * the headroom they think they need without accounting for the
1466 * built in space. The built in space is used for optimisations.
1468 * %NULL is returned if there is no free memory. Although this function
1469 * allocates memory it can be called from an interrupt.
1471 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1472 unsigned int length)
1474 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1477 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1480 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1481 * @dev: network device to receive on
1483 * Allocate a new page node local to the specified device.
1485 * %NULL is returned if there is no free memory.
1487 static inline struct page *netdev_alloc_page(struct net_device *dev)
1489 return __netdev_alloc_page(dev, GFP_ATOMIC);
1492 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1498 * skb_clone_writable - is the header of a clone writable
1499 * @skb: buffer to check
1500 * @len: length up to which to write
1502 * Returns true if modifying the header part of the cloned buffer
1503 * does not requires the data to be copied.
1505 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1507 return !skb_header_cloned(skb) &&
1508 skb_headroom(skb) + len <= skb->hdr_len;
1511 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1516 if (headroom < NET_SKB_PAD)
1517 headroom = NET_SKB_PAD;
1518 if (headroom > skb_headroom(skb))
1519 delta = headroom - skb_headroom(skb);
1521 if (delta || cloned)
1522 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1528 * skb_cow - copy header of skb when it is required
1529 * @skb: buffer to cow
1530 * @headroom: needed headroom
1532 * If the skb passed lacks sufficient headroom or its data part
1533 * is shared, data is reallocated. If reallocation fails, an error
1534 * is returned and original skb is not changed.
1536 * The result is skb with writable area skb->head...skb->tail
1537 * and at least @headroom of space at head.
1539 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1541 return __skb_cow(skb, headroom, skb_cloned(skb));
1545 * skb_cow_head - skb_cow but only making the head writable
1546 * @skb: buffer to cow
1547 * @headroom: needed headroom
1549 * This function is identical to skb_cow except that we replace the
1550 * skb_cloned check by skb_header_cloned. It should be used when
1551 * you only need to push on some header and do not need to modify
1554 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1556 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1560 * skb_padto - pad an skbuff up to a minimal size
1561 * @skb: buffer to pad
1562 * @len: minimal length
1564 * Pads up a buffer to ensure the trailing bytes exist and are
1565 * blanked. If the buffer already contains sufficient data it
1566 * is untouched. Otherwise it is extended. Returns zero on
1567 * success. The skb is freed on error.
1570 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1572 unsigned int size = skb->len;
1573 if (likely(size >= len))
1575 return skb_pad(skb, len - size);
1578 static inline int skb_add_data(struct sk_buff *skb,
1579 char __user *from, int copy)
1581 const int off = skb->len;
1583 if (skb->ip_summed == CHECKSUM_NONE) {
1585 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1588 skb->csum = csum_block_add(skb->csum, csum, off);
1591 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1594 __skb_trim(skb, off);
1598 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1599 struct page *page, int off)
1602 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1604 return page == frag->page &&
1605 off == frag->page_offset + frag->size;
1610 static inline int __skb_linearize(struct sk_buff *skb)
1612 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1616 * skb_linearize - convert paged skb to linear one
1617 * @skb: buffer to linarize
1619 * If there is no free memory -ENOMEM is returned, otherwise zero
1620 * is returned and the old skb data released.
1622 static inline int skb_linearize(struct sk_buff *skb)
1624 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1628 * skb_linearize_cow - make sure skb is linear and writable
1629 * @skb: buffer to process
1631 * If there is no free memory -ENOMEM is returned, otherwise zero
1632 * is returned and the old skb data released.
1634 static inline int skb_linearize_cow(struct sk_buff *skb)
1636 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1637 __skb_linearize(skb) : 0;
1641 * skb_postpull_rcsum - update checksum for received skb after pull
1642 * @skb: buffer to update
1643 * @start: start of data before pull
1644 * @len: length of data pulled
1646 * After doing a pull on a received packet, you need to call this to
1647 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1648 * CHECKSUM_NONE so that it can be recomputed from scratch.
1651 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1652 const void *start, unsigned int len)
1654 if (skb->ip_summed == CHECKSUM_COMPLETE)
1655 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1658 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1661 * pskb_trim_rcsum - trim received skb and update checksum
1662 * @skb: buffer to trim
1665 * This is exactly the same as pskb_trim except that it ensures the
1666 * checksum of received packets are still valid after the operation.
1669 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1671 if (likely(len >= skb->len))
1673 if (skb->ip_summed == CHECKSUM_COMPLETE)
1674 skb->ip_summed = CHECKSUM_NONE;
1675 return __pskb_trim(skb, len);
1678 #define skb_queue_walk(queue, skb) \
1679 for (skb = (queue)->next; \
1680 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1683 #define skb_queue_walk_safe(queue, skb, tmp) \
1684 for (skb = (queue)->next, tmp = skb->next; \
1685 skb != (struct sk_buff *)(queue); \
1686 skb = tmp, tmp = skb->next)
1688 #define skb_queue_walk_from(queue, skb) \
1689 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1692 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1693 for (tmp = skb->next; \
1694 skb != (struct sk_buff *)(queue); \
1695 skb = tmp, tmp = skb->next)
1697 #define skb_queue_reverse_walk(queue, skb) \
1698 for (skb = (queue)->prev; \
1699 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1703 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1704 int *peeked, int *err);
1705 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1706 int noblock, int *err);
1707 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1708 struct poll_table_struct *wait);
1709 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1710 int offset, struct iovec *to,
1712 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1715 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1719 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1720 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1721 unsigned int flags);
1722 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1723 int len, __wsum csum);
1724 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1726 extern int skb_store_bits(struct sk_buff *skb, int offset,
1727 const void *from, int len);
1728 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1729 int offset, u8 *to, int len,
1731 extern int skb_splice_bits(struct sk_buff *skb,
1732 unsigned int offset,
1733 struct pipe_inode_info *pipe,
1735 unsigned int flags);
1736 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1737 extern void skb_split(struct sk_buff *skb,
1738 struct sk_buff *skb1, const u32 len);
1739 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1742 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1744 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1745 int len, void *buffer)
1747 int hlen = skb_headlen(skb);
1749 if (hlen - offset >= len)
1750 return skb->data + offset;
1752 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1758 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1760 const unsigned int len)
1762 memcpy(to, skb->data, len);
1765 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1766 const int offset, void *to,
1767 const unsigned int len)
1769 memcpy(to, skb->data + offset, len);
1772 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1774 const unsigned int len)
1776 memcpy(skb->data, from, len);
1779 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1782 const unsigned int len)
1784 memcpy(skb->data + offset, from, len);
1787 extern void skb_init(void);
1789 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1795 * skb_get_timestamp - get timestamp from a skb
1796 * @skb: skb to get stamp from
1797 * @stamp: pointer to struct timeval to store stamp in
1799 * Timestamps are stored in the skb as offsets to a base timestamp.
1800 * This function converts the offset back to a struct timeval and stores
1803 static inline void skb_get_timestamp(const struct sk_buff *skb,
1804 struct timeval *stamp)
1806 *stamp = ktime_to_timeval(skb->tstamp);
1809 static inline void skb_get_timestampns(const struct sk_buff *skb,
1810 struct timespec *stamp)
1812 *stamp = ktime_to_timespec(skb->tstamp);
1815 static inline void __net_timestamp(struct sk_buff *skb)
1817 skb->tstamp = ktime_get_real();
1820 static inline ktime_t net_timedelta(ktime_t t)
1822 return ktime_sub(ktime_get_real(), t);
1825 static inline ktime_t net_invalid_timestamp(void)
1827 return ktime_set(0, 0);
1831 * skb_tstamp_tx - queue clone of skb with send time stamps
1832 * @orig_skb: the original outgoing packet
1833 * @hwtstamps: hardware time stamps, may be NULL if not available
1835 * If the skb has a socket associated, then this function clones the
1836 * skb (thus sharing the actual data and optional structures), stores
1837 * the optional hardware time stamping information (if non NULL) or
1838 * generates a software time stamp (otherwise), then queues the clone
1839 * to the error queue of the socket. Errors are silently ignored.
1841 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1842 struct skb_shared_hwtstamps *hwtstamps);
1844 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1845 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1847 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1849 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1853 * skb_checksum_complete - Calculate checksum of an entire packet
1854 * @skb: packet to process
1856 * This function calculates the checksum over the entire packet plus
1857 * the value of skb->csum. The latter can be used to supply the
1858 * checksum of a pseudo header as used by TCP/UDP. It returns the
1861 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1862 * this function can be used to verify that checksum on received
1863 * packets. In that case the function should return zero if the
1864 * checksum is correct. In particular, this function will return zero
1865 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1866 * hardware has already verified the correctness of the checksum.
1868 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1870 return skb_csum_unnecessary(skb) ?
1871 0 : __skb_checksum_complete(skb);
1874 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1875 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1876 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1878 if (nfct && atomic_dec_and_test(&nfct->use))
1879 nf_conntrack_destroy(nfct);
1881 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1884 atomic_inc(&nfct->use);
1886 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1889 atomic_inc(&skb->users);
1891 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1897 #ifdef CONFIG_BRIDGE_NETFILTER
1898 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1900 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1903 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1906 atomic_inc(&nf_bridge->use);
1908 #endif /* CONFIG_BRIDGE_NETFILTER */
1909 static inline void nf_reset(struct sk_buff *skb)
1911 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1912 nf_conntrack_put(skb->nfct);
1914 nf_conntrack_put_reasm(skb->nfct_reasm);
1915 skb->nfct_reasm = NULL;
1917 #ifdef CONFIG_BRIDGE_NETFILTER
1918 nf_bridge_put(skb->nf_bridge);
1919 skb->nf_bridge = NULL;
1923 /* Note: This doesn't put any conntrack and bridge info in dst. */
1924 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1926 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1927 dst->nfct = src->nfct;
1928 nf_conntrack_get(src->nfct);
1929 dst->nfctinfo = src->nfctinfo;
1930 dst->nfct_reasm = src->nfct_reasm;
1931 nf_conntrack_get_reasm(src->nfct_reasm);
1933 #ifdef CONFIG_BRIDGE_NETFILTER
1934 dst->nf_bridge = src->nf_bridge;
1935 nf_bridge_get(src->nf_bridge);
1939 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1941 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1942 nf_conntrack_put(dst->nfct);
1943 nf_conntrack_put_reasm(dst->nfct_reasm);
1945 #ifdef CONFIG_BRIDGE_NETFILTER
1946 nf_bridge_put(dst->nf_bridge);
1948 __nf_copy(dst, src);
1951 #ifdef CONFIG_NETWORK_SECMARK
1952 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1954 to->secmark = from->secmark;
1957 static inline void skb_init_secmark(struct sk_buff *skb)
1962 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1965 static inline void skb_init_secmark(struct sk_buff *skb)
1969 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
1971 skb->queue_mapping = queue_mapping;
1974 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
1976 return skb->queue_mapping;
1979 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
1981 to->queue_mapping = from->queue_mapping;
1984 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
1986 skb->queue_mapping = rx_queue + 1;
1989 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
1991 return skb->queue_mapping - 1;
1994 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
1996 return (skb->queue_mapping != 0);
1999 extern u16 skb_tx_hash(const struct net_device *dev,
2000 const struct sk_buff *skb);
2003 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2008 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2014 static inline int skb_is_gso(const struct sk_buff *skb)
2016 return skb_shinfo(skb)->gso_size;
2019 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2021 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2024 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2026 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2028 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2029 * wanted then gso_type will be set. */
2030 struct skb_shared_info *shinfo = skb_shinfo(skb);
2031 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2032 __skb_warn_lro_forwarding(skb);
2038 static inline void skb_forward_csum(struct sk_buff *skb)
2040 /* Unfortunately we don't support this one. Any brave souls? */
2041 if (skb->ip_summed == CHECKSUM_COMPLETE)
2042 skb->ip_summed = CHECKSUM_NONE;
2045 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2046 #endif /* __KERNEL__ */
2047 #endif /* _LINUX_SKBUFF_H */