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 #define HAVE_ALLOC_SKB /* For the drivers to know */
33 #define HAVE_ALIGNABLE_SKB /* Ditto 8) */
35 /* Don't change this without changing skb_csum_unnecessary! */
36 #define CHECKSUM_NONE 0
37 #define CHECKSUM_UNNECESSARY 1
38 #define CHECKSUM_COMPLETE 2
39 #define CHECKSUM_PARTIAL 3
41 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
42 ~(SMP_CACHE_BYTES - 1))
43 #define SKB_WITH_OVERHEAD(X) \
44 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
45 #define SKB_MAX_ORDER(X, ORDER) \
46 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
47 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
48 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
50 /* A. Checksumming of received packets by device.
52 * NONE: device failed to checksum this packet.
53 * skb->csum is undefined.
55 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
56 * skb->csum is undefined.
57 * It is bad option, but, unfortunately, many of vendors do this.
58 * Apparently with secret goal to sell you new device, when you
59 * will add new protocol to your host. F.e. IPv6. 8)
61 * COMPLETE: the most generic way. Device supplied checksum of _all_
62 * the packet as seen by netif_rx in skb->csum.
63 * NOTE: Even if device supports only some protocols, but
64 * is able to produce some skb->csum, it MUST use COMPLETE,
67 * PARTIAL: identical to the case for output below. This may occur
68 * on a packet received directly from another Linux OS, e.g.,
69 * a virtualised Linux kernel on the same host. The packet can
70 * be treated in the same way as UNNECESSARY except that on
71 * output (i.e., forwarding) the checksum must be filled in
72 * by the OS or the hardware.
74 * B. Checksumming on output.
76 * NONE: skb is checksummed by protocol or csum is not required.
78 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
79 * from skb->csum_start to the end and to record the checksum
80 * at skb->csum_start + skb->csum_offset.
82 * Device must show its capabilities in dev->features, set
83 * at device setup time.
84 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
86 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
87 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
88 * TCP/UDP over IPv4. Sigh. Vendors like this
89 * way by an unknown reason. Though, see comment above
90 * about CHECKSUM_UNNECESSARY. 8)
91 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
93 * Any questions? No questions, good. --ANK
98 struct pipe_inode_info
;
100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
101 struct nf_conntrack
{
106 #ifdef CONFIG_BRIDGE_NETFILTER
107 struct nf_bridge_info
{
109 struct net_device
*physindev
;
110 struct net_device
*physoutdev
;
112 unsigned long data
[32 / sizeof(unsigned long)];
116 struct sk_buff_head
{
117 /* These two members must be first. */
118 struct sk_buff
*next
;
119 struct sk_buff
*prev
;
127 /* To allow 64K frame to be packed as single skb without frag_list */
128 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
130 typedef struct skb_frag_struct skb_frag_t
;
132 struct skb_frag_struct
{
138 /* This data is invariant across clones and lives at
139 * the end of the header data, ie. at skb->end.
141 struct skb_shared_info
{
143 unsigned short nr_frags
;
144 unsigned short gso_size
;
145 /* Warning: this field is not always filled in (UFO)! */
146 unsigned short gso_segs
;
147 unsigned short gso_type
;
149 #ifdef CONFIG_HAS_DMA
150 unsigned int num_dma_maps
;
152 struct sk_buff
*frag_list
;
153 skb_frag_t frags
[MAX_SKB_FRAGS
];
154 #ifdef CONFIG_HAS_DMA
155 dma_addr_t dma_maps
[MAX_SKB_FRAGS
+ 1];
159 /* We divide dataref into two halves. The higher 16 bits hold references
160 * to the payload part of skb->data. The lower 16 bits hold references to
161 * the entire skb->data. A clone of a headerless skb holds the length of
162 * the header in skb->hdr_len.
164 * All users must obey the rule that the skb->data reference count must be
165 * greater than or equal to the payload reference count.
167 * Holding a reference to the payload part means that the user does not
168 * care about modifications to the header part of skb->data.
170 #define SKB_DATAREF_SHIFT 16
171 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
175 SKB_FCLONE_UNAVAILABLE
,
181 SKB_GSO_TCPV4
= 1 << 0,
182 SKB_GSO_UDP
= 1 << 1,
184 /* This indicates the skb is from an untrusted source. */
185 SKB_GSO_DODGY
= 1 << 2,
187 /* This indicates the tcp segment has CWR set. */
188 SKB_GSO_TCP_ECN
= 1 << 3,
190 SKB_GSO_TCPV6
= 1 << 4,
193 #if BITS_PER_LONG > 32
194 #define NET_SKBUFF_DATA_USES_OFFSET 1
197 #ifdef NET_SKBUFF_DATA_USES_OFFSET
198 typedef unsigned int sk_buff_data_t
;
200 typedef unsigned char *sk_buff_data_t
;
204 * struct sk_buff - socket buffer
205 * @next: Next buffer in list
206 * @prev: Previous buffer in list
207 * @sk: Socket we are owned by
208 * @tstamp: Time we arrived
209 * @dev: Device we arrived on/are leaving by
210 * @transport_header: Transport layer header
211 * @network_header: Network layer header
212 * @mac_header: Link layer header
213 * @dst: destination entry
214 * @sp: the security path, used for xfrm
215 * @cb: Control buffer. Free for use by every layer. Put private vars here
216 * @len: Length of actual data
217 * @data_len: Data length
218 * @mac_len: Length of link layer header
219 * @hdr_len: writable header length of cloned skb
220 * @csum: Checksum (must include start/offset pair)
221 * @csum_start: Offset from skb->head where checksumming should start
222 * @csum_offset: Offset from csum_start where checksum should be stored
223 * @local_df: allow local fragmentation
224 * @cloned: Head may be cloned (check refcnt to be sure)
225 * @nohdr: Payload reference only, must not modify header
226 * @pkt_type: Packet class
227 * @fclone: skbuff clone status
228 * @ip_summed: Driver fed us an IP checksum
229 * @priority: Packet queueing priority
230 * @users: User count - see {datagram,tcp}.c
231 * @protocol: Packet protocol from driver
232 * @truesize: Buffer size
233 * @head: Head of buffer
234 * @data: Data head pointer
235 * @tail: Tail pointer
237 * @destructor: Destruct function
238 * @mark: Generic packet mark
239 * @nfct: Associated connection, if any
240 * @ipvs_property: skbuff is owned by ipvs
241 * @peeked: this packet has been seen already, so stats have been
242 * done for it, don't do them again
243 * @nf_trace: netfilter packet trace flag
244 * @nfctinfo: Relationship of this skb to the connection
245 * @nfct_reasm: netfilter conntrack re-assembly pointer
246 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
247 * @iif: ifindex of device we arrived on
248 * @queue_mapping: Queue mapping for multiqueue devices
249 * @tc_index: Traffic control index
250 * @tc_verd: traffic control verdict
251 * @ndisc_nodetype: router type (from link layer)
252 * @do_not_encrypt: set to prevent encryption of this frame
253 * @requeue: set to indicate that the wireless core should attempt
254 * a software retry on this frame if we failed to
255 * receive an ACK for it
256 * @dma_cookie: a cookie to one of several possible DMA operations
257 * done by skb DMA functions
258 * @secmark: security marking
259 * @vlan_tci: vlan tag control information
263 /* These two members must be first. */
264 struct sk_buff
*next
;
265 struct sk_buff
*prev
;
269 struct net_device
*dev
;
272 struct dst_entry
*dst
;
273 struct rtable
*rtable
;
279 * This is the control buffer. It is free to use for every
280 * layer. Please put your private variables there. If you
281 * want to keep them across layers you have to do a skb_clone()
282 * first. This is owned by whoever has the skb queued ATM.
310 void (*destructor
)(struct sk_buff
*skb
);
311 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
312 struct nf_conntrack
*nfct
;
313 struct sk_buff
*nfct_reasm
;
315 #ifdef CONFIG_BRIDGE_NETFILTER
316 struct nf_bridge_info
*nf_bridge
;
321 #ifdef CONFIG_NET_SCHED
322 __u16 tc_index
; /* traffic control index */
323 #ifdef CONFIG_NET_CLS_ACT
324 __u16 tc_verd
; /* traffic control verdict */
327 #ifdef CONFIG_IPV6_NDISC_NODETYPE
328 __u8 ndisc_nodetype
:2;
330 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
331 __u8 do_not_encrypt
:1;
334 /* 0/13/14 bit hole */
336 #ifdef CONFIG_NET_DMA
337 dma_cookie_t dma_cookie
;
339 #ifdef CONFIG_NETWORK_SECMARK
347 sk_buff_data_t transport_header
;
348 sk_buff_data_t network_header
;
349 sk_buff_data_t mac_header
;
350 /* These elements must be at the end, see alloc_skb() for details. */
355 unsigned int truesize
;
361 * Handling routines are only of interest to the kernel
363 #include <linux/slab.h>
365 #include <asm/system.h>
367 #ifdef CONFIG_HAS_DMA
368 #include <linux/dma-mapping.h>
369 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
370 enum dma_data_direction dir
);
371 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
372 enum dma_data_direction dir
);
375 extern void kfree_skb(struct sk_buff
*skb
);
376 extern void __kfree_skb(struct sk_buff
*skb
);
377 extern struct sk_buff
*__alloc_skb(unsigned int size
,
378 gfp_t priority
, int fclone
, int node
);
379 static inline struct sk_buff
*alloc_skb(unsigned int size
,
382 return __alloc_skb(size
, priority
, 0, -1);
385 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
388 return __alloc_skb(size
, priority
, 1, -1);
391 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
393 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
394 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
396 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
398 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
400 extern int pskb_expand_head(struct sk_buff
*skb
,
401 int nhead
, int ntail
,
403 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
404 unsigned int headroom
);
405 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
406 int newheadroom
, int newtailroom
,
408 extern int skb_to_sgvec(struct sk_buff
*skb
,
409 struct scatterlist
*sg
, int offset
,
411 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
412 struct sk_buff
**trailer
);
413 extern int skb_pad(struct sk_buff
*skb
, int pad
);
414 #define dev_kfree_skb(a) kfree_skb(a)
415 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
417 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
420 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
421 int getfrag(void *from
, char *to
, int offset
,
422 int len
,int odd
, struct sk_buff
*skb
),
423 void *from
, int length
);
430 __u32 stepped_offset
;
431 struct sk_buff
*root_skb
;
432 struct sk_buff
*cur_skb
;
436 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
437 unsigned int from
, unsigned int to
,
438 struct skb_seq_state
*st
);
439 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
440 struct skb_seq_state
*st
);
441 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
443 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
444 unsigned int to
, struct ts_config
*config
,
445 struct ts_state
*state
);
447 #ifdef NET_SKBUFF_DATA_USES_OFFSET
448 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
450 return skb
->head
+ skb
->end
;
453 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
460 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
463 * skb_queue_empty - check if a queue is empty
466 * Returns true if the queue is empty, false otherwise.
468 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
470 return list
->next
== (struct sk_buff
*)list
;
474 * skb_queue_is_last - check if skb is the last entry in the queue
478 * Returns true if @skb is the last buffer on the list.
480 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
481 const struct sk_buff
*skb
)
483 return (skb
->next
== (struct sk_buff
*) list
);
487 * skb_queue_is_first - check if skb is the first entry in the queue
491 * Returns true if @skb is the first buffer on the list.
493 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
494 const struct sk_buff
*skb
)
496 return (skb
->prev
== (struct sk_buff
*) list
);
500 * skb_queue_next - return the next packet in the queue
502 * @skb: current buffer
504 * Return the next packet in @list after @skb. It is only valid to
505 * call this if skb_queue_is_last() evaluates to false.
507 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
508 const struct sk_buff
*skb
)
510 /* This BUG_ON may seem severe, but if we just return then we
511 * are going to dereference garbage.
513 BUG_ON(skb_queue_is_last(list
, skb
));
518 * skb_queue_prev - return the prev packet in the queue
520 * @skb: current buffer
522 * Return the prev packet in @list before @skb. It is only valid to
523 * call this if skb_queue_is_first() evaluates to false.
525 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
526 const struct sk_buff
*skb
)
528 /* This BUG_ON may seem severe, but if we just return then we
529 * are going to dereference garbage.
531 BUG_ON(skb_queue_is_first(list
, skb
));
536 * skb_get - reference buffer
537 * @skb: buffer to reference
539 * Makes another reference to a socket buffer and returns a pointer
542 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
544 atomic_inc(&skb
->users
);
549 * If users == 1, we are the only owner and are can avoid redundant
554 * skb_cloned - is the buffer a clone
555 * @skb: buffer to check
557 * Returns true if the buffer was generated with skb_clone() and is
558 * one of multiple shared copies of the buffer. Cloned buffers are
559 * shared data so must not be written to under normal circumstances.
561 static inline int skb_cloned(const struct sk_buff
*skb
)
563 return skb
->cloned
&&
564 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
568 * skb_header_cloned - is the header a clone
569 * @skb: buffer to check
571 * Returns true if modifying the header part of the buffer requires
572 * the data to be copied.
574 static inline int skb_header_cloned(const struct sk_buff
*skb
)
581 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
582 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
587 * skb_header_release - release reference to header
588 * @skb: buffer to operate on
590 * Drop a reference to the header part of the buffer. This is done
591 * by acquiring a payload reference. You must not read from the header
592 * part of skb->data after this.
594 static inline void skb_header_release(struct sk_buff
*skb
)
598 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
602 * skb_shared - is the buffer shared
603 * @skb: buffer to check
605 * Returns true if more than one person has a reference to this
608 static inline int skb_shared(const struct sk_buff
*skb
)
610 return atomic_read(&skb
->users
) != 1;
614 * skb_share_check - check if buffer is shared and if so clone it
615 * @skb: buffer to check
616 * @pri: priority for memory allocation
618 * If the buffer is shared the buffer is cloned and the old copy
619 * drops a reference. A new clone with a single reference is returned.
620 * If the buffer is not shared the original buffer is returned. When
621 * being called from interrupt status or with spinlocks held pri must
624 * NULL is returned on a memory allocation failure.
626 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
629 might_sleep_if(pri
& __GFP_WAIT
);
630 if (skb_shared(skb
)) {
631 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
639 * Copy shared buffers into a new sk_buff. We effectively do COW on
640 * packets to handle cases where we have a local reader and forward
641 * and a couple of other messy ones. The normal one is tcpdumping
642 * a packet thats being forwarded.
646 * skb_unshare - make a copy of a shared buffer
647 * @skb: buffer to check
648 * @pri: priority for memory allocation
650 * If the socket buffer is a clone then this function creates a new
651 * copy of the data, drops a reference count on the old copy and returns
652 * the new copy with the reference count at 1. If the buffer is not a clone
653 * the original buffer is returned. When called with a spinlock held or
654 * from interrupt state @pri must be %GFP_ATOMIC
656 * %NULL is returned on a memory allocation failure.
658 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
661 might_sleep_if(pri
& __GFP_WAIT
);
662 if (skb_cloned(skb
)) {
663 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
664 kfree_skb(skb
); /* Free our shared copy */
672 * @list_: list to peek at
674 * Peek an &sk_buff. Unlike most other operations you _MUST_
675 * be careful with this one. A peek leaves the buffer on the
676 * list and someone else may run off with it. You must hold
677 * the appropriate locks or have a private queue to do this.
679 * Returns %NULL for an empty list or a pointer to the head element.
680 * The reference count is not incremented and the reference is therefore
681 * volatile. Use with caution.
683 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
685 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
686 if (list
== (struct sk_buff
*)list_
)
693 * @list_: list to peek at
695 * Peek an &sk_buff. Unlike most other operations you _MUST_
696 * be careful with this one. A peek leaves the buffer on the
697 * list and someone else may run off with it. You must hold
698 * the appropriate locks or have a private queue to do this.
700 * Returns %NULL for an empty list or a pointer to the tail element.
701 * The reference count is not incremented and the reference is therefore
702 * volatile. Use with caution.
704 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
706 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
707 if (list
== (struct sk_buff
*)list_
)
713 * skb_queue_len - get queue length
714 * @list_: list to measure
716 * Return the length of an &sk_buff queue.
718 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
724 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
725 * @list: queue to initialize
727 * This initializes only the list and queue length aspects of
728 * an sk_buff_head object. This allows to initialize the list
729 * aspects of an sk_buff_head without reinitializing things like
730 * the spinlock. It can also be used for on-stack sk_buff_head
731 * objects where the spinlock is known to not be used.
733 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
735 list
->prev
= list
->next
= (struct sk_buff
*)list
;
740 * This function creates a split out lock class for each invocation;
741 * this is needed for now since a whole lot of users of the skb-queue
742 * infrastructure in drivers have different locking usage (in hardirq)
743 * than the networking core (in softirq only). In the long run either the
744 * network layer or drivers should need annotation to consolidate the
745 * main types of usage into 3 classes.
747 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
749 spin_lock_init(&list
->lock
);
750 __skb_queue_head_init(list
);
753 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
754 struct lock_class_key
*class)
756 skb_queue_head_init(list
);
757 lockdep_set_class(&list
->lock
, class);
761 * Insert an sk_buff on a list.
763 * The "__skb_xxxx()" functions are the non-atomic ones that
764 * can only be called with interrupts disabled.
766 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
767 static inline void __skb_insert(struct sk_buff
*newsk
,
768 struct sk_buff
*prev
, struct sk_buff
*next
,
769 struct sk_buff_head
*list
)
773 next
->prev
= prev
->next
= newsk
;
777 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
778 struct sk_buff
*prev
,
779 struct sk_buff
*next
)
781 struct sk_buff
*first
= list
->next
;
782 struct sk_buff
*last
= list
->prev
;
792 * skb_queue_splice - join two skb lists, this is designed for stacks
793 * @list: the new list to add
794 * @head: the place to add it in the first list
796 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
797 struct sk_buff_head
*head
)
799 if (!skb_queue_empty(list
)) {
800 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
801 head
->qlen
+= list
->qlen
;
806 * skb_queue_splice - join two skb lists and reinitialise the emptied list
807 * @list: the new list to add
808 * @head: the place to add it in the first list
810 * The list at @list is reinitialised
812 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
813 struct sk_buff_head
*head
)
815 if (!skb_queue_empty(list
)) {
816 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
817 head
->qlen
+= list
->qlen
;
818 __skb_queue_head_init(list
);
823 * skb_queue_splice_tail - join two skb lists, each list being a queue
824 * @list: the new list to add
825 * @head: the place to add it in the first list
827 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
828 struct sk_buff_head
*head
)
830 if (!skb_queue_empty(list
)) {
831 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
832 head
->qlen
+= list
->qlen
;
837 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
838 * @list: the new list to add
839 * @head: the place to add it in the first list
841 * Each of the lists is a queue.
842 * The list at @list is reinitialised
844 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
845 struct sk_buff_head
*head
)
847 if (!skb_queue_empty(list
)) {
848 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
849 head
->qlen
+= list
->qlen
;
850 __skb_queue_head_init(list
);
855 * __skb_queue_after - queue a buffer at the list head
857 * @prev: place after this buffer
858 * @newsk: buffer to queue
860 * Queue a buffer int the middle of a list. This function takes no locks
861 * and you must therefore hold required locks before calling it.
863 * A buffer cannot be placed on two lists at the same time.
865 static inline void __skb_queue_after(struct sk_buff_head
*list
,
866 struct sk_buff
*prev
,
867 struct sk_buff
*newsk
)
869 __skb_insert(newsk
, prev
, prev
->next
, list
);
872 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
873 struct sk_buff_head
*list
);
875 static inline void __skb_queue_before(struct sk_buff_head
*list
,
876 struct sk_buff
*next
,
877 struct sk_buff
*newsk
)
879 __skb_insert(newsk
, next
->prev
, next
, list
);
883 * __skb_queue_head - queue a buffer at the list head
885 * @newsk: buffer to queue
887 * Queue a buffer at the start of a list. This function takes no locks
888 * and you must therefore hold required locks before calling it.
890 * A buffer cannot be placed on two lists at the same time.
892 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
893 static inline void __skb_queue_head(struct sk_buff_head
*list
,
894 struct sk_buff
*newsk
)
896 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
900 * __skb_queue_tail - queue a buffer at the list tail
902 * @newsk: buffer to queue
904 * Queue a buffer at the end of a list. This function takes no locks
905 * and you must therefore hold required locks before calling it.
907 * A buffer cannot be placed on two lists at the same time.
909 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
910 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
911 struct sk_buff
*newsk
)
913 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
917 * remove sk_buff from list. _Must_ be called atomically, and with
920 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
921 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
923 struct sk_buff
*next
, *prev
;
928 skb
->next
= skb
->prev
= NULL
;
934 * __skb_dequeue - remove from the head of the queue
935 * @list: list to dequeue from
937 * Remove the head of the list. This function does not take any locks
938 * so must be used with appropriate locks held only. The head item is
939 * returned or %NULL if the list is empty.
941 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
942 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
944 struct sk_buff
*skb
= skb_peek(list
);
946 __skb_unlink(skb
, list
);
951 * __skb_dequeue_tail - remove from the tail of the queue
952 * @list: list to dequeue from
954 * Remove the tail of the list. This function does not take any locks
955 * so must be used with appropriate locks held only. The tail item is
956 * returned or %NULL if the list is empty.
958 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
959 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
961 struct sk_buff
*skb
= skb_peek_tail(list
);
963 __skb_unlink(skb
, list
);
968 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
970 return skb
->data_len
;
973 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
975 return skb
->len
- skb
->data_len
;
978 static inline int skb_pagelen(const struct sk_buff
*skb
)
982 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
983 len
+= skb_shinfo(skb
)->frags
[i
].size
;
984 return len
+ skb_headlen(skb
);
987 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
988 struct page
*page
, int off
, int size
)
990 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
993 frag
->page_offset
= off
;
995 skb_shinfo(skb
)->nr_frags
= i
+ 1;
998 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1001 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1002 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1003 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1005 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1006 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1008 return skb
->head
+ skb
->tail
;
1011 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1013 skb
->tail
= skb
->data
- skb
->head
;
1016 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1018 skb_reset_tail_pointer(skb
);
1019 skb
->tail
+= offset
;
1021 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1022 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1027 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1029 skb
->tail
= skb
->data
;
1032 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1034 skb
->tail
= skb
->data
+ offset
;
1037 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1040 * Add data to an sk_buff
1042 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1043 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1045 unsigned char *tmp
= skb_tail_pointer(skb
);
1046 SKB_LINEAR_ASSERT(skb
);
1052 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1053 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1060 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1061 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1064 BUG_ON(skb
->len
< skb
->data_len
);
1065 return skb
->data
+= len
;
1068 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1070 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1072 if (len
> skb_headlen(skb
) &&
1073 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1076 return skb
->data
+= len
;
1079 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1081 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1084 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1086 if (likely(len
<= skb_headlen(skb
)))
1088 if (unlikely(len
> skb
->len
))
1090 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1094 * skb_headroom - bytes at buffer head
1095 * @skb: buffer to check
1097 * Return the number of bytes of free space at the head of an &sk_buff.
1099 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1101 return skb
->data
- skb
->head
;
1105 * skb_tailroom - bytes at buffer end
1106 * @skb: buffer to check
1108 * Return the number of bytes of free space at the tail of an sk_buff
1110 static inline int skb_tailroom(const struct sk_buff
*skb
)
1112 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1116 * skb_reserve - adjust headroom
1117 * @skb: buffer to alter
1118 * @len: bytes to move
1120 * Increase the headroom of an empty &sk_buff by reducing the tail
1121 * room. This is only allowed for an empty buffer.
1123 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1129 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1130 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1132 return skb
->head
+ skb
->transport_header
;
1135 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1137 skb
->transport_header
= skb
->data
- skb
->head
;
1140 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1143 skb_reset_transport_header(skb
);
1144 skb
->transport_header
+= offset
;
1147 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1149 return skb
->head
+ skb
->network_header
;
1152 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1154 skb
->network_header
= skb
->data
- skb
->head
;
1157 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1159 skb_reset_network_header(skb
);
1160 skb
->network_header
+= offset
;
1163 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1165 return skb
->head
+ skb
->mac_header
;
1168 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1170 return skb
->mac_header
!= ~0U;
1173 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1175 skb
->mac_header
= skb
->data
- skb
->head
;
1178 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1180 skb_reset_mac_header(skb
);
1181 skb
->mac_header
+= offset
;
1184 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1186 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1188 return skb
->transport_header
;
1191 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1193 skb
->transport_header
= skb
->data
;
1196 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1199 skb
->transport_header
= skb
->data
+ offset
;
1202 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1204 return skb
->network_header
;
1207 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1209 skb
->network_header
= skb
->data
;
1212 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1214 skb
->network_header
= skb
->data
+ offset
;
1217 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1219 return skb
->mac_header
;
1222 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1224 return skb
->mac_header
!= NULL
;
1227 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1229 skb
->mac_header
= skb
->data
;
1232 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1234 skb
->mac_header
= skb
->data
+ offset
;
1236 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1238 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1240 return skb_transport_header(skb
) - skb
->data
;
1243 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1245 return skb
->transport_header
- skb
->network_header
;
1248 static inline int skb_network_offset(const struct sk_buff
*skb
)
1250 return skb_network_header(skb
) - skb
->data
;
1254 * CPUs often take a performance hit when accessing unaligned memory
1255 * locations. The actual performance hit varies, it can be small if the
1256 * hardware handles it or large if we have to take an exception and fix it
1259 * Since an ethernet header is 14 bytes network drivers often end up with
1260 * the IP header at an unaligned offset. The IP header can be aligned by
1261 * shifting the start of the packet by 2 bytes. Drivers should do this
1264 * skb_reserve(NET_IP_ALIGN);
1266 * The downside to this alignment of the IP header is that the DMA is now
1267 * unaligned. On some architectures the cost of an unaligned DMA is high
1268 * and this cost outweighs the gains made by aligning the IP header.
1270 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1273 #ifndef NET_IP_ALIGN
1274 #define NET_IP_ALIGN 2
1278 * The networking layer reserves some headroom in skb data (via
1279 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1280 * the header has to grow. In the default case, if the header has to grow
1281 * 16 bytes or less we avoid the reallocation.
1283 * Unfortunately this headroom changes the DMA alignment of the resulting
1284 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1285 * on some architectures. An architecture can override this value,
1286 * perhaps setting it to a cacheline in size (since that will maintain
1287 * cacheline alignment of the DMA). It must be a power of 2.
1289 * Various parts of the networking layer expect at least 16 bytes of
1290 * headroom, you should not reduce this.
1293 #define NET_SKB_PAD 16
1296 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1298 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1300 if (unlikely(skb
->data_len
)) {
1305 skb_set_tail_pointer(skb
, len
);
1308 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1310 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1313 return ___pskb_trim(skb
, len
);
1314 __skb_trim(skb
, len
);
1318 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1320 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1324 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1325 * @skb: buffer to alter
1328 * This is identical to pskb_trim except that the caller knows that
1329 * the skb is not cloned so we should never get an error due to out-
1332 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1334 int err
= pskb_trim(skb
, len
);
1339 * skb_orphan - orphan a buffer
1340 * @skb: buffer to orphan
1342 * If a buffer currently has an owner then we call the owner's
1343 * destructor function and make the @skb unowned. The buffer continues
1344 * to exist but is no longer charged to its former owner.
1346 static inline void skb_orphan(struct sk_buff
*skb
)
1348 if (skb
->destructor
)
1349 skb
->destructor(skb
);
1350 skb
->destructor
= NULL
;
1355 * __skb_queue_purge - empty a list
1356 * @list: list to empty
1358 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1359 * the list and one reference dropped. This function does not take the
1360 * list lock and the caller must hold the relevant locks to use it.
1362 extern void skb_queue_purge(struct sk_buff_head
*list
);
1363 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1365 struct sk_buff
*skb
;
1366 while ((skb
= __skb_dequeue(list
)) != NULL
)
1371 * __dev_alloc_skb - allocate an skbuff for receiving
1372 * @length: length to allocate
1373 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1375 * Allocate a new &sk_buff and assign it a usage count of one. The
1376 * buffer has unspecified headroom built in. Users should allocate
1377 * the headroom they think they need without accounting for the
1378 * built in space. The built in space is used for optimisations.
1380 * %NULL is returned if there is no free memory.
1382 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1385 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1387 skb_reserve(skb
, NET_SKB_PAD
);
1391 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1393 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1394 unsigned int length
, gfp_t gfp_mask
);
1397 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1398 * @dev: network device to receive on
1399 * @length: length to allocate
1401 * Allocate a new &sk_buff and assign it a usage count of one. The
1402 * buffer has unspecified headroom built in. Users should allocate
1403 * the headroom they think they need without accounting for the
1404 * built in space. The built in space is used for optimisations.
1406 * %NULL is returned if there is no free memory. Although this function
1407 * allocates memory it can be called from an interrupt.
1409 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1410 unsigned int length
)
1412 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1415 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1418 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1419 * @dev: network device to receive on
1421 * Allocate a new page node local to the specified device.
1423 * %NULL is returned if there is no free memory.
1425 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1427 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1430 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1436 * skb_clone_writable - is the header of a clone writable
1437 * @skb: buffer to check
1438 * @len: length up to which to write
1440 * Returns true if modifying the header part of the cloned buffer
1441 * does not requires the data to be copied.
1443 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1445 return !skb_header_cloned(skb
) &&
1446 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1449 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1454 if (headroom
< NET_SKB_PAD
)
1455 headroom
= NET_SKB_PAD
;
1456 if (headroom
> skb_headroom(skb
))
1457 delta
= headroom
- skb_headroom(skb
);
1459 if (delta
|| cloned
)
1460 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1466 * skb_cow - copy header of skb when it is required
1467 * @skb: buffer to cow
1468 * @headroom: needed headroom
1470 * If the skb passed lacks sufficient headroom or its data part
1471 * is shared, data is reallocated. If reallocation fails, an error
1472 * is returned and original skb is not changed.
1474 * The result is skb with writable area skb->head...skb->tail
1475 * and at least @headroom of space at head.
1477 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1479 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1483 * skb_cow_head - skb_cow but only making the head writable
1484 * @skb: buffer to cow
1485 * @headroom: needed headroom
1487 * This function is identical to skb_cow except that we replace the
1488 * skb_cloned check by skb_header_cloned. It should be used when
1489 * you only need to push on some header and do not need to modify
1492 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1494 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1498 * skb_padto - pad an skbuff up to a minimal size
1499 * @skb: buffer to pad
1500 * @len: minimal length
1502 * Pads up a buffer to ensure the trailing bytes exist and are
1503 * blanked. If the buffer already contains sufficient data it
1504 * is untouched. Otherwise it is extended. Returns zero on
1505 * success. The skb is freed on error.
1508 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1510 unsigned int size
= skb
->len
;
1511 if (likely(size
>= len
))
1513 return skb_pad(skb
, len
- size
);
1516 static inline int skb_add_data(struct sk_buff
*skb
,
1517 char __user
*from
, int copy
)
1519 const int off
= skb
->len
;
1521 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1523 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1526 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1529 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1532 __skb_trim(skb
, off
);
1536 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1537 struct page
*page
, int off
)
1540 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1542 return page
== frag
->page
&&
1543 off
== frag
->page_offset
+ frag
->size
;
1548 static inline int __skb_linearize(struct sk_buff
*skb
)
1550 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1554 * skb_linearize - convert paged skb to linear one
1555 * @skb: buffer to linarize
1557 * If there is no free memory -ENOMEM is returned, otherwise zero
1558 * is returned and the old skb data released.
1560 static inline int skb_linearize(struct sk_buff
*skb
)
1562 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1566 * skb_linearize_cow - make sure skb is linear and writable
1567 * @skb: buffer to process
1569 * If there is no free memory -ENOMEM is returned, otherwise zero
1570 * is returned and the old skb data released.
1572 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1574 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1575 __skb_linearize(skb
) : 0;
1579 * skb_postpull_rcsum - update checksum for received skb after pull
1580 * @skb: buffer to update
1581 * @start: start of data before pull
1582 * @len: length of data pulled
1584 * After doing a pull on a received packet, you need to call this to
1585 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1586 * CHECKSUM_NONE so that it can be recomputed from scratch.
1589 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1590 const void *start
, unsigned int len
)
1592 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1593 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1596 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1599 * pskb_trim_rcsum - trim received skb and update checksum
1600 * @skb: buffer to trim
1603 * This is exactly the same as pskb_trim except that it ensures the
1604 * checksum of received packets are still valid after the operation.
1607 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1609 if (likely(len
>= skb
->len
))
1611 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1612 skb
->ip_summed
= CHECKSUM_NONE
;
1613 return __pskb_trim(skb
, len
);
1616 #define skb_queue_walk(queue, skb) \
1617 for (skb = (queue)->next; \
1618 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1621 #define skb_queue_walk_safe(queue, skb, tmp) \
1622 for (skb = (queue)->next, tmp = skb->next; \
1623 skb != (struct sk_buff *)(queue); \
1624 skb = tmp, tmp = skb->next)
1626 #define skb_queue_walk_from(queue, skb) \
1627 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1630 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1631 for (tmp = skb->next; \
1632 skb != (struct sk_buff *)(queue); \
1633 skb = tmp, tmp = skb->next)
1635 #define skb_queue_reverse_walk(queue, skb) \
1636 for (skb = (queue)->prev; \
1637 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1641 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1642 int *peeked
, int *err
);
1643 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1644 int noblock
, int *err
);
1645 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1646 struct poll_table_struct
*wait
);
1647 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1648 int offset
, struct iovec
*to
,
1650 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1653 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1657 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1658 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1659 unsigned int flags
);
1660 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1661 int len
, __wsum csum
);
1662 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1664 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1665 const void *from
, int len
);
1666 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1667 int offset
, u8
*to
, int len
,
1669 extern int skb_splice_bits(struct sk_buff
*skb
,
1670 unsigned int offset
,
1671 struct pipe_inode_info
*pipe
,
1673 unsigned int flags
);
1674 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1675 extern void skb_split(struct sk_buff
*skb
,
1676 struct sk_buff
*skb1
, const u32 len
);
1677 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1680 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1681 extern int skb_gro_receive(struct sk_buff
**head
,
1682 struct sk_buff
*skb
);
1684 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1685 int len
, void *buffer
)
1687 int hlen
= skb_headlen(skb
);
1689 if (hlen
- offset
>= len
)
1690 return skb
->data
+ offset
;
1692 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1698 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1700 const unsigned int len
)
1702 memcpy(to
, skb
->data
, len
);
1705 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1706 const int offset
, void *to
,
1707 const unsigned int len
)
1709 memcpy(to
, skb
->data
+ offset
, len
);
1712 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1714 const unsigned int len
)
1716 memcpy(skb
->data
, from
, len
);
1719 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1722 const unsigned int len
)
1724 memcpy(skb
->data
+ offset
, from
, len
);
1727 extern void skb_init(void);
1730 * skb_get_timestamp - get timestamp from a skb
1731 * @skb: skb to get stamp from
1732 * @stamp: pointer to struct timeval to store stamp in
1734 * Timestamps are stored in the skb as offsets to a base timestamp.
1735 * This function converts the offset back to a struct timeval and stores
1738 static inline void skb_get_timestamp(const struct sk_buff
*skb
, struct timeval
*stamp
)
1740 *stamp
= ktime_to_timeval(skb
->tstamp
);
1743 static inline void __net_timestamp(struct sk_buff
*skb
)
1745 skb
->tstamp
= ktime_get_real();
1748 static inline ktime_t
net_timedelta(ktime_t t
)
1750 return ktime_sub(ktime_get_real(), t
);
1753 static inline ktime_t
net_invalid_timestamp(void)
1755 return ktime_set(0, 0);
1758 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1759 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1761 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1763 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1767 * skb_checksum_complete - Calculate checksum of an entire packet
1768 * @skb: packet to process
1770 * This function calculates the checksum over the entire packet plus
1771 * the value of skb->csum. The latter can be used to supply the
1772 * checksum of a pseudo header as used by TCP/UDP. It returns the
1775 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1776 * this function can be used to verify that checksum on received
1777 * packets. In that case the function should return zero if the
1778 * checksum is correct. In particular, this function will return zero
1779 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1780 * hardware has already verified the correctness of the checksum.
1782 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1784 return skb_csum_unnecessary(skb
) ?
1785 0 : __skb_checksum_complete(skb
);
1788 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1789 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1790 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1792 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1793 nf_conntrack_destroy(nfct
);
1795 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1798 atomic_inc(&nfct
->use
);
1800 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1803 atomic_inc(&skb
->users
);
1805 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1811 #ifdef CONFIG_BRIDGE_NETFILTER
1812 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1814 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1817 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1820 atomic_inc(&nf_bridge
->use
);
1822 #endif /* CONFIG_BRIDGE_NETFILTER */
1823 static inline void nf_reset(struct sk_buff
*skb
)
1825 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1826 nf_conntrack_put(skb
->nfct
);
1828 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1829 skb
->nfct_reasm
= NULL
;
1831 #ifdef CONFIG_BRIDGE_NETFILTER
1832 nf_bridge_put(skb
->nf_bridge
);
1833 skb
->nf_bridge
= NULL
;
1837 /* Note: This doesn't put any conntrack and bridge info in dst. */
1838 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1840 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1841 dst
->nfct
= src
->nfct
;
1842 nf_conntrack_get(src
->nfct
);
1843 dst
->nfctinfo
= src
->nfctinfo
;
1844 dst
->nfct_reasm
= src
->nfct_reasm
;
1845 nf_conntrack_get_reasm(src
->nfct_reasm
);
1847 #ifdef CONFIG_BRIDGE_NETFILTER
1848 dst
->nf_bridge
= src
->nf_bridge
;
1849 nf_bridge_get(src
->nf_bridge
);
1853 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1855 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1856 nf_conntrack_put(dst
->nfct
);
1857 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1859 #ifdef CONFIG_BRIDGE_NETFILTER
1860 nf_bridge_put(dst
->nf_bridge
);
1862 __nf_copy(dst
, src
);
1865 #ifdef CONFIG_NETWORK_SECMARK
1866 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1868 to
->secmark
= from
->secmark
;
1871 static inline void skb_init_secmark(struct sk_buff
*skb
)
1876 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1879 static inline void skb_init_secmark(struct sk_buff
*skb
)
1883 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1885 skb
->queue_mapping
= queue_mapping
;
1888 static inline u16
skb_get_queue_mapping(struct sk_buff
*skb
)
1890 return skb
->queue_mapping
;
1893 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1895 to
->queue_mapping
= from
->queue_mapping
;
1899 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
1904 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
1910 static inline int skb_is_gso(const struct sk_buff
*skb
)
1912 return skb_shinfo(skb
)->gso_size
;
1915 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
1917 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
1920 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
1922 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
1924 /* LRO sets gso_size but not gso_type, whereas if GSO is really
1925 * wanted then gso_type will be set. */
1926 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
1927 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
1928 __skb_warn_lro_forwarding(skb
);
1934 static inline void skb_forward_csum(struct sk_buff
*skb
)
1936 /* Unfortunately we don't support this one. Any brave souls? */
1937 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1938 skb
->ip_summed
= CHECKSUM_NONE
;
1941 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
1942 #endif /* __KERNEL__ */
1943 #endif /* _LINUX_SKBUFF_H */