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
99 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
100 struct nf_conntrack
{
105 #ifdef CONFIG_BRIDGE_NETFILTER
106 struct nf_bridge_info
{
108 struct net_device
*physindev
;
109 struct net_device
*physoutdev
;
110 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
111 struct net_device
*netoutdev
;
114 unsigned long data
[32 / sizeof(unsigned long)];
118 struct sk_buff_head
{
119 /* These two members must be first. */
120 struct sk_buff
*next
;
121 struct sk_buff
*prev
;
129 /* To allow 64K frame to be packed as single skb without frag_list */
130 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
132 typedef struct skb_frag_struct skb_frag_t
;
134 struct skb_frag_struct
{
140 /* This data is invariant across clones and lives at
141 * the end of the header data, ie. at skb->end.
143 struct skb_shared_info
{
145 unsigned short nr_frags
;
146 unsigned short gso_size
;
147 /* Warning: this field is not always filled in (UFO)! */
148 unsigned short gso_segs
;
149 unsigned short gso_type
;
151 struct sk_buff
*frag_list
;
152 skb_frag_t frags
[MAX_SKB_FRAGS
];
155 /* We divide dataref into two halves. The higher 16 bits hold references
156 * to the payload part of skb->data. The lower 16 bits hold references to
157 * the entire skb->data. A clone of a headerless skb holds the length of
158 * the header in skb->hdr_len.
160 * All users must obey the rule that the skb->data reference count must be
161 * greater than or equal to the payload reference count.
163 * Holding a reference to the payload part means that the user does not
164 * care about modifications to the header part of skb->data.
166 #define SKB_DATAREF_SHIFT 16
167 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
171 SKB_FCLONE_UNAVAILABLE
,
177 SKB_GSO_TCPV4
= 1 << 0,
178 SKB_GSO_UDP
= 1 << 1,
180 /* This indicates the skb is from an untrusted source. */
181 SKB_GSO_DODGY
= 1 << 2,
183 /* This indicates the tcp segment has CWR set. */
184 SKB_GSO_TCP_ECN
= 1 << 3,
186 SKB_GSO_TCPV6
= 1 << 4,
189 #if BITS_PER_LONG > 32
190 #define NET_SKBUFF_DATA_USES_OFFSET 1
193 #ifdef NET_SKBUFF_DATA_USES_OFFSET
194 typedef unsigned int sk_buff_data_t
;
196 typedef unsigned char *sk_buff_data_t
;
200 * struct sk_buff - socket buffer
201 * @next: Next buffer in list
202 * @prev: Previous buffer in list
203 * @sk: Socket we are owned by
204 * @tstamp: Time we arrived
205 * @dev: Device we arrived on/are leaving by
206 * @transport_header: Transport layer header
207 * @network_header: Network layer header
208 * @mac_header: Link layer header
209 * @dst: destination entry
210 * @sp: the security path, used for xfrm
211 * @cb: Control buffer. Free for use by every layer. Put private vars here
212 * @len: Length of actual data
213 * @data_len: Data length
214 * @mac_len: Length of link layer header
215 * @hdr_len: writable header length of cloned skb
216 * @csum: Checksum (must include start/offset pair)
217 * @csum_start: Offset from skb->head where checksumming should start
218 * @csum_offset: Offset from csum_start where checksum should be stored
219 * @local_df: allow local fragmentation
220 * @cloned: Head may be cloned (check refcnt to be sure)
221 * @nohdr: Payload reference only, must not modify header
222 * @pkt_type: Packet class
223 * @fclone: skbuff clone status
224 * @ip_summed: Driver fed us an IP checksum
225 * @priority: Packet queueing priority
226 * @users: User count - see {datagram,tcp}.c
227 * @protocol: Packet protocol from driver
228 * @truesize: Buffer size
229 * @head: Head of buffer
230 * @data: Data head pointer
231 * @tail: Tail pointer
233 * @destructor: Destruct function
234 * @mark: Generic packet mark
235 * @nfct: Associated connection, if any
236 * @ipvs_property: skbuff is owned by ipvs
237 * @nf_trace: netfilter packet trace flag
238 * @nfctinfo: Relationship of this skb to the connection
239 * @nfct_reasm: netfilter conntrack re-assembly pointer
240 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
241 * @iif: ifindex of device we arrived on
242 * @queue_mapping: Queue mapping for multiqueue devices
243 * @tc_index: Traffic control index
244 * @tc_verd: traffic control verdict
245 * @dma_cookie: a cookie to one of several possible DMA operations
246 * done by skb DMA functions
247 * @secmark: security marking
251 /* These two members must be first. */
252 struct sk_buff
*next
;
253 struct sk_buff
*prev
;
257 struct net_device
*dev
;
259 struct dst_entry
*dst
;
263 * This is the control buffer. It is free to use for every
264 * layer. Please put your private variables there. If you
265 * want to keep them across layers you have to do a skb_clone()
266 * first. This is owned by whoever has the skb queued ATM.
293 void (*destructor
)(struct sk_buff
*skb
);
294 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
295 struct nf_conntrack
*nfct
;
296 struct sk_buff
*nfct_reasm
;
298 #ifdef CONFIG_BRIDGE_NETFILTER
299 struct nf_bridge_info
*nf_bridge
;
303 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
306 #ifdef CONFIG_NET_SCHED
307 __u16 tc_index
; /* traffic control index */
308 #ifdef CONFIG_NET_CLS_ACT
309 __u16 tc_verd
; /* traffic control verdict */
314 #ifdef CONFIG_NET_DMA
315 dma_cookie_t dma_cookie
;
317 #ifdef CONFIG_NETWORK_SECMARK
323 sk_buff_data_t transport_header
;
324 sk_buff_data_t network_header
;
325 sk_buff_data_t mac_header
;
326 /* These elements must be at the end, see alloc_skb() for details. */
331 unsigned int truesize
;
337 * Handling routines are only of interest to the kernel
339 #include <linux/slab.h>
341 #include <asm/system.h>
343 extern void kfree_skb(struct sk_buff
*skb
);
344 extern void __kfree_skb(struct sk_buff
*skb
);
345 extern struct sk_buff
*__alloc_skb(unsigned int size
,
346 gfp_t priority
, int fclone
, int node
);
347 static inline struct sk_buff
*alloc_skb(unsigned int size
,
350 return __alloc_skb(size
, priority
, 0, -1);
353 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
356 return __alloc_skb(size
, priority
, 1, -1);
359 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
360 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
362 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
364 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
366 extern int pskb_expand_head(struct sk_buff
*skb
,
367 int nhead
, int ntail
,
369 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
370 unsigned int headroom
);
371 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
372 int newheadroom
, int newtailroom
,
374 extern int skb_to_sgvec(struct sk_buff
*skb
,
375 struct scatterlist
*sg
, int offset
,
377 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
378 struct sk_buff
**trailer
);
379 extern int skb_pad(struct sk_buff
*skb
, int pad
);
380 #define dev_kfree_skb(a) kfree_skb(a)
381 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
383 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
385 extern void skb_truesize_bug(struct sk_buff
*skb
);
387 static inline void skb_truesize_check(struct sk_buff
*skb
)
389 int len
= sizeof(struct sk_buff
) + skb
->len
;
391 if (unlikely((int)skb
->truesize
< len
))
392 skb_truesize_bug(skb
);
395 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
396 int getfrag(void *from
, char *to
, int offset
,
397 int len
,int odd
, struct sk_buff
*skb
),
398 void *from
, int length
);
405 __u32 stepped_offset
;
406 struct sk_buff
*root_skb
;
407 struct sk_buff
*cur_skb
;
411 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
412 unsigned int from
, unsigned int to
,
413 struct skb_seq_state
*st
);
414 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
415 struct skb_seq_state
*st
);
416 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
418 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
419 unsigned int to
, struct ts_config
*config
,
420 struct ts_state
*state
);
422 #ifdef NET_SKBUFF_DATA_USES_OFFSET
423 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
425 return skb
->head
+ skb
->end
;
428 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
435 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
438 * skb_queue_empty - check if a queue is empty
441 * Returns true if the queue is empty, false otherwise.
443 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
445 return list
->next
== (struct sk_buff
*)list
;
449 * skb_get - reference buffer
450 * @skb: buffer to reference
452 * Makes another reference to a socket buffer and returns a pointer
455 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
457 atomic_inc(&skb
->users
);
462 * If users == 1, we are the only owner and are can avoid redundant
467 * skb_cloned - is the buffer a clone
468 * @skb: buffer to check
470 * Returns true if the buffer was generated with skb_clone() and is
471 * one of multiple shared copies of the buffer. Cloned buffers are
472 * shared data so must not be written to under normal circumstances.
474 static inline int skb_cloned(const struct sk_buff
*skb
)
476 return skb
->cloned
&&
477 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
481 * skb_header_cloned - is the header a clone
482 * @skb: buffer to check
484 * Returns true if modifying the header part of the buffer requires
485 * the data to be copied.
487 static inline int skb_header_cloned(const struct sk_buff
*skb
)
494 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
495 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
500 * skb_header_release - release reference to header
501 * @skb: buffer to operate on
503 * Drop a reference to the header part of the buffer. This is done
504 * by acquiring a payload reference. You must not read from the header
505 * part of skb->data after this.
507 static inline void skb_header_release(struct sk_buff
*skb
)
511 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
515 * skb_shared - is the buffer shared
516 * @skb: buffer to check
518 * Returns true if more than one person has a reference to this
521 static inline int skb_shared(const struct sk_buff
*skb
)
523 return atomic_read(&skb
->users
) != 1;
527 * skb_share_check - check if buffer is shared and if so clone it
528 * @skb: buffer to check
529 * @pri: priority for memory allocation
531 * If the buffer is shared the buffer is cloned and the old copy
532 * drops a reference. A new clone with a single reference is returned.
533 * If the buffer is not shared the original buffer is returned. When
534 * being called from interrupt status or with spinlocks held pri must
537 * NULL is returned on a memory allocation failure.
539 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
542 might_sleep_if(pri
& __GFP_WAIT
);
543 if (skb_shared(skb
)) {
544 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
552 * Copy shared buffers into a new sk_buff. We effectively do COW on
553 * packets to handle cases where we have a local reader and forward
554 * and a couple of other messy ones. The normal one is tcpdumping
555 * a packet thats being forwarded.
559 * skb_unshare - make a copy of a shared buffer
560 * @skb: buffer to check
561 * @pri: priority for memory allocation
563 * If the socket buffer is a clone then this function creates a new
564 * copy of the data, drops a reference count on the old copy and returns
565 * the new copy with the reference count at 1. If the buffer is not a clone
566 * the original buffer is returned. When called with a spinlock held or
567 * from interrupt state @pri must be %GFP_ATOMIC
569 * %NULL is returned on a memory allocation failure.
571 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
574 might_sleep_if(pri
& __GFP_WAIT
);
575 if (skb_cloned(skb
)) {
576 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
577 kfree_skb(skb
); /* Free our shared copy */
585 * @list_: list to peek at
587 * Peek an &sk_buff. Unlike most other operations you _MUST_
588 * be careful with this one. A peek leaves the buffer on the
589 * list and someone else may run off with it. You must hold
590 * the appropriate locks or have a private queue to do this.
592 * Returns %NULL for an empty list or a pointer to the head element.
593 * The reference count is not incremented and the reference is therefore
594 * volatile. Use with caution.
596 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
598 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
599 if (list
== (struct sk_buff
*)list_
)
606 * @list_: list to peek at
608 * Peek an &sk_buff. Unlike most other operations you _MUST_
609 * be careful with this one. A peek leaves the buffer on the
610 * list and someone else may run off with it. You must hold
611 * the appropriate locks or have a private queue to do this.
613 * Returns %NULL for an empty list or a pointer to the tail element.
614 * The reference count is not incremented and the reference is therefore
615 * volatile. Use with caution.
617 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
619 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
620 if (list
== (struct sk_buff
*)list_
)
626 * skb_queue_len - get queue length
627 * @list_: list to measure
629 * Return the length of an &sk_buff queue.
631 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
637 * This function creates a split out lock class for each invocation;
638 * this is needed for now since a whole lot of users of the skb-queue
639 * infrastructure in drivers have different locking usage (in hardirq)
640 * than the networking core (in softirq only). In the long run either the
641 * network layer or drivers should need annotation to consolidate the
642 * main types of usage into 3 classes.
644 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
646 spin_lock_init(&list
->lock
);
647 list
->prev
= list
->next
= (struct sk_buff
*)list
;
651 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
652 struct lock_class_key
*class)
654 skb_queue_head_init(list
);
655 lockdep_set_class(&list
->lock
, class);
659 * Insert an sk_buff at the start of a list.
661 * The "__skb_xxxx()" functions are the non-atomic ones that
662 * can only be called with interrupts disabled.
666 * __skb_queue_after - queue a buffer at the list head
668 * @prev: place after this buffer
669 * @newsk: buffer to queue
671 * Queue a buffer int the middle of a list. This function takes no locks
672 * and you must therefore hold required locks before calling it.
674 * A buffer cannot be placed on two lists at the same time.
676 static inline void __skb_queue_after(struct sk_buff_head
*list
,
677 struct sk_buff
*prev
,
678 struct sk_buff
*newsk
)
680 struct sk_buff
*next
;
686 next
->prev
= prev
->next
= newsk
;
690 * __skb_queue_head - queue a buffer at the list head
692 * @newsk: buffer to queue
694 * Queue a buffer at the start of a list. This function takes no locks
695 * and you must therefore hold required locks before calling it.
697 * A buffer cannot be placed on two lists at the same time.
699 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
700 static inline void __skb_queue_head(struct sk_buff_head
*list
,
701 struct sk_buff
*newsk
)
703 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
707 * __skb_queue_tail - queue a buffer at the list tail
709 * @newsk: buffer to queue
711 * Queue a buffer at the end of a list. This function takes no locks
712 * and you must therefore hold required locks before calling it.
714 * A buffer cannot be placed on two lists at the same time.
716 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
717 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
718 struct sk_buff
*newsk
)
720 struct sk_buff
*prev
, *next
;
723 next
= (struct sk_buff
*)list
;
727 next
->prev
= prev
->next
= newsk
;
732 * __skb_dequeue - remove from the head of the queue
733 * @list: list to dequeue from
735 * Remove the head of the list. This function does not take any locks
736 * so must be used with appropriate locks held only. The head item is
737 * returned or %NULL if the list is empty.
739 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
740 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
742 struct sk_buff
*next
, *prev
, *result
;
744 prev
= (struct sk_buff
*) list
;
753 result
->next
= result
->prev
= NULL
;
760 * Insert a packet on a list.
762 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
763 static inline void __skb_insert(struct sk_buff
*newsk
,
764 struct sk_buff
*prev
, struct sk_buff
*next
,
765 struct sk_buff_head
*list
)
769 next
->prev
= prev
->next
= newsk
;
774 * Place a packet after a given packet in a list.
776 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
777 static inline void __skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
779 __skb_insert(newsk
, old
, old
->next
, list
);
783 * remove sk_buff from list. _Must_ be called atomically, and with
786 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
787 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
789 struct sk_buff
*next
, *prev
;
794 skb
->next
= skb
->prev
= NULL
;
800 /* XXX: more streamlined implementation */
803 * __skb_dequeue_tail - remove from the tail of the queue
804 * @list: list to dequeue from
806 * Remove the tail of the list. This function does not take any locks
807 * so must be used with appropriate locks held only. The tail item is
808 * returned or %NULL if the list is empty.
810 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
811 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
813 struct sk_buff
*skb
= skb_peek_tail(list
);
815 __skb_unlink(skb
, list
);
820 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
822 return skb
->data_len
;
825 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
827 return skb
->len
- skb
->data_len
;
830 static inline int skb_pagelen(const struct sk_buff
*skb
)
834 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
835 len
+= skb_shinfo(skb
)->frags
[i
].size
;
836 return len
+ skb_headlen(skb
);
839 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
840 struct page
*page
, int off
, int size
)
842 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
845 frag
->page_offset
= off
;
847 skb_shinfo(skb
)->nr_frags
= i
+ 1;
850 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
851 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
852 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
854 #ifdef NET_SKBUFF_DATA_USES_OFFSET
855 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
857 return skb
->head
+ skb
->tail
;
860 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
862 skb
->tail
= skb
->data
- skb
->head
;
865 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
867 skb_reset_tail_pointer(skb
);
870 #else /* NET_SKBUFF_DATA_USES_OFFSET */
871 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
876 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
878 skb
->tail
= skb
->data
;
881 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
883 skb
->tail
= skb
->data
+ offset
;
886 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
889 * Add data to an sk_buff
891 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
893 unsigned char *tmp
= skb_tail_pointer(skb
);
894 SKB_LINEAR_ASSERT(skb
);
901 * skb_put - add data to a buffer
902 * @skb: buffer to use
903 * @len: amount of data to add
905 * This function extends the used data area of the buffer. If this would
906 * exceed the total buffer size the kernel will panic. A pointer to the
907 * first byte of the extra data is returned.
909 static inline unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
)
911 unsigned char *tmp
= skb_tail_pointer(skb
);
912 SKB_LINEAR_ASSERT(skb
);
915 if (unlikely(skb
->tail
> skb
->end
))
916 skb_over_panic(skb
, len
, current_text_addr());
920 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
928 * skb_push - add data to the start of a buffer
929 * @skb: buffer to use
930 * @len: amount of data to add
932 * This function extends the used data area of the buffer at the buffer
933 * start. If this would exceed the total buffer headroom the kernel will
934 * panic. A pointer to the first byte of the extra data is returned.
936 static inline unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
)
940 if (unlikely(skb
->data
<skb
->head
))
941 skb_under_panic(skb
, len
, current_text_addr());
945 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
948 BUG_ON(skb
->len
< skb
->data_len
);
949 return skb
->data
+= len
;
953 * skb_pull - remove data from the start of a buffer
954 * @skb: buffer to use
955 * @len: amount of data to remove
957 * This function removes data from the start of a buffer, returning
958 * the memory to the headroom. A pointer to the next data in the buffer
959 * is returned. Once the data has been pulled future pushes will overwrite
962 static inline unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
)
964 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
967 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
969 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
971 if (len
> skb_headlen(skb
) &&
972 !__pskb_pull_tail(skb
, len
-skb_headlen(skb
)))
975 return skb
->data
+= len
;
978 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
980 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
983 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
985 if (likely(len
<= skb_headlen(skb
)))
987 if (unlikely(len
> skb
->len
))
989 return __pskb_pull_tail(skb
, len
-skb_headlen(skb
)) != NULL
;
993 * skb_headroom - bytes at buffer head
994 * @skb: buffer to check
996 * Return the number of bytes of free space at the head of an &sk_buff.
998 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1000 return skb
->data
- skb
->head
;
1004 * skb_tailroom - bytes at buffer end
1005 * @skb: buffer to check
1007 * Return the number of bytes of free space at the tail of an sk_buff
1009 static inline int skb_tailroom(const struct sk_buff
*skb
)
1011 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1015 * skb_reserve - adjust headroom
1016 * @skb: buffer to alter
1017 * @len: bytes to move
1019 * Increase the headroom of an empty &sk_buff by reducing the tail
1020 * room. This is only allowed for an empty buffer.
1022 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1028 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1029 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1031 return skb
->head
+ skb
->transport_header
;
1034 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1036 skb
->transport_header
= skb
->data
- skb
->head
;
1039 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1042 skb_reset_transport_header(skb
);
1043 skb
->transport_header
+= offset
;
1046 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1048 return skb
->head
+ skb
->network_header
;
1051 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1053 skb
->network_header
= skb
->data
- skb
->head
;
1056 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1058 skb_reset_network_header(skb
);
1059 skb
->network_header
+= offset
;
1062 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1064 return skb
->head
+ skb
->mac_header
;
1067 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1069 return skb
->mac_header
!= ~0U;
1072 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1074 skb
->mac_header
= skb
->data
- skb
->head
;
1077 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1079 skb_reset_mac_header(skb
);
1080 skb
->mac_header
+= offset
;
1083 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1085 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1087 return skb
->transport_header
;
1090 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1092 skb
->transport_header
= skb
->data
;
1095 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1098 skb
->transport_header
= skb
->data
+ offset
;
1101 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1103 return skb
->network_header
;
1106 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1108 skb
->network_header
= skb
->data
;
1111 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1113 skb
->network_header
= skb
->data
+ offset
;
1116 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1118 return skb
->mac_header
;
1121 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1123 return skb
->mac_header
!= NULL
;
1126 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1128 skb
->mac_header
= skb
->data
;
1131 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1133 skb
->mac_header
= skb
->data
+ offset
;
1135 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1137 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1139 return skb_transport_header(skb
) - skb
->data
;
1142 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1144 return skb
->transport_header
- skb
->network_header
;
1147 static inline int skb_network_offset(const struct sk_buff
*skb
)
1149 return skb_network_header(skb
) - skb
->data
;
1153 * CPUs often take a performance hit when accessing unaligned memory
1154 * locations. The actual performance hit varies, it can be small if the
1155 * hardware handles it or large if we have to take an exception and fix it
1158 * Since an ethernet header is 14 bytes network drivers often end up with
1159 * the IP header at an unaligned offset. The IP header can be aligned by
1160 * shifting the start of the packet by 2 bytes. Drivers should do this
1163 * skb_reserve(NET_IP_ALIGN);
1165 * The downside to this alignment of the IP header is that the DMA is now
1166 * unaligned. On some architectures the cost of an unaligned DMA is high
1167 * and this cost outweighs the gains made by aligning the IP header.
1169 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1172 #ifndef NET_IP_ALIGN
1173 #define NET_IP_ALIGN 2
1177 * The networking layer reserves some headroom in skb data (via
1178 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1179 * the header has to grow. In the default case, if the header has to grow
1180 * 16 bytes or less we avoid the reallocation.
1182 * Unfortunately this headroom changes the DMA alignment of the resulting
1183 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1184 * on some architectures. An architecture can override this value,
1185 * perhaps setting it to a cacheline in size (since that will maintain
1186 * cacheline alignment of the DMA). It must be a power of 2.
1188 * Various parts of the networking layer expect at least 16 bytes of
1189 * headroom, you should not reduce this.
1192 #define NET_SKB_PAD 16
1195 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1197 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1199 if (unlikely(skb
->data_len
)) {
1204 skb_set_tail_pointer(skb
, len
);
1208 * skb_trim - remove end from a buffer
1209 * @skb: buffer to alter
1212 * Cut the length of a buffer down by removing data from the tail. If
1213 * the buffer is already under the length specified it is not modified.
1214 * The skb must be linear.
1216 static inline void skb_trim(struct sk_buff
*skb
, unsigned int len
)
1219 __skb_trim(skb
, len
);
1223 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1226 return ___pskb_trim(skb
, len
);
1227 __skb_trim(skb
, len
);
1231 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1233 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1237 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1238 * @skb: buffer to alter
1241 * This is identical to pskb_trim except that the caller knows that
1242 * the skb is not cloned so we should never get an error due to out-
1245 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1247 int err
= pskb_trim(skb
, len
);
1252 * skb_orphan - orphan a buffer
1253 * @skb: buffer to orphan
1255 * If a buffer currently has an owner then we call the owner's
1256 * destructor function and make the @skb unowned. The buffer continues
1257 * to exist but is no longer charged to its former owner.
1259 static inline void skb_orphan(struct sk_buff
*skb
)
1261 if (skb
->destructor
)
1262 skb
->destructor(skb
);
1263 skb
->destructor
= NULL
;
1268 * __skb_queue_purge - empty a list
1269 * @list: list to empty
1271 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1272 * the list and one reference dropped. This function does not take the
1273 * list lock and the caller must hold the relevant locks to use it.
1275 extern void skb_queue_purge(struct sk_buff_head
*list
);
1276 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1278 struct sk_buff
*skb
;
1279 while ((skb
= __skb_dequeue(list
)) != NULL
)
1284 * __dev_alloc_skb - allocate an skbuff for receiving
1285 * @length: length to allocate
1286 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1288 * Allocate a new &sk_buff and assign it a usage count of one. The
1289 * buffer has unspecified headroom built in. Users should allocate
1290 * the headroom they think they need without accounting for the
1291 * built in space. The built in space is used for optimisations.
1293 * %NULL is returned if there is no free memory.
1295 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1298 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1300 skb_reserve(skb
, NET_SKB_PAD
);
1305 * dev_alloc_skb - allocate an skbuff for receiving
1306 * @length: length to allocate
1308 * Allocate a new &sk_buff and assign it a usage count of one. The
1309 * buffer has unspecified headroom built in. Users should allocate
1310 * the headroom they think they need without accounting for the
1311 * built in space. The built in space is used for optimisations.
1313 * %NULL is returned if there is no free memory. Although this function
1314 * allocates memory it can be called from an interrupt.
1316 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1318 return __dev_alloc_skb(length
, GFP_ATOMIC
);
1321 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1322 unsigned int length
, gfp_t gfp_mask
);
1325 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1326 * @dev: network device to receive on
1327 * @length: length to allocate
1329 * Allocate a new &sk_buff and assign it a usage count of one. The
1330 * buffer has unspecified headroom built in. Users should allocate
1331 * the headroom they think they need without accounting for the
1332 * built in space. The built in space is used for optimisations.
1334 * %NULL is returned if there is no free memory. Although this function
1335 * allocates memory it can be called from an interrupt.
1337 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1338 unsigned int length
)
1340 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1344 * skb_clone_writable - is the header of a clone writable
1345 * @skb: buffer to check
1346 * @len: length up to which to write
1348 * Returns true if modifying the header part of the cloned buffer
1349 * does not requires the data to be copied.
1351 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1353 return !skb_header_cloned(skb
) &&
1354 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1357 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1362 if (headroom
< NET_SKB_PAD
)
1363 headroom
= NET_SKB_PAD
;
1364 if (headroom
> skb_headroom(skb
))
1365 delta
= headroom
- skb_headroom(skb
);
1367 if (delta
|| cloned
)
1368 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1374 * skb_cow - copy header of skb when it is required
1375 * @skb: buffer to cow
1376 * @headroom: needed headroom
1378 * If the skb passed lacks sufficient headroom or its data part
1379 * is shared, data is reallocated. If reallocation fails, an error
1380 * is returned and original skb is not changed.
1382 * The result is skb with writable area skb->head...skb->tail
1383 * and at least @headroom of space at head.
1385 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1387 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1391 * skb_cow_head - skb_cow but only making the head writable
1392 * @skb: buffer to cow
1393 * @headroom: needed headroom
1395 * This function is identical to skb_cow except that we replace the
1396 * skb_cloned check by skb_header_cloned. It should be used when
1397 * you only need to push on some header and do not need to modify
1400 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1402 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1406 * skb_padto - pad an skbuff up to a minimal size
1407 * @skb: buffer to pad
1408 * @len: minimal length
1410 * Pads up a buffer to ensure the trailing bytes exist and are
1411 * blanked. If the buffer already contains sufficient data it
1412 * is untouched. Otherwise it is extended. Returns zero on
1413 * success. The skb is freed on error.
1416 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1418 unsigned int size
= skb
->len
;
1419 if (likely(size
>= len
))
1421 return skb_pad(skb
, len
-size
);
1424 static inline int skb_add_data(struct sk_buff
*skb
,
1425 char __user
*from
, int copy
)
1427 const int off
= skb
->len
;
1429 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1431 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1434 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1437 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1440 __skb_trim(skb
, off
);
1444 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1445 struct page
*page
, int off
)
1448 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1450 return page
== frag
->page
&&
1451 off
== frag
->page_offset
+ frag
->size
;
1456 static inline int __skb_linearize(struct sk_buff
*skb
)
1458 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1462 * skb_linearize - convert paged skb to linear one
1463 * @skb: buffer to linarize
1465 * If there is no free memory -ENOMEM is returned, otherwise zero
1466 * is returned and the old skb data released.
1468 static inline int skb_linearize(struct sk_buff
*skb
)
1470 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1474 * skb_linearize_cow - make sure skb is linear and writable
1475 * @skb: buffer to process
1477 * If there is no free memory -ENOMEM is returned, otherwise zero
1478 * is returned and the old skb data released.
1480 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1482 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1483 __skb_linearize(skb
) : 0;
1487 * skb_postpull_rcsum - update checksum for received skb after pull
1488 * @skb: buffer to update
1489 * @start: start of data before pull
1490 * @len: length of data pulled
1492 * After doing a pull on a received packet, you need to call this to
1493 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1494 * CHECKSUM_NONE so that it can be recomputed from scratch.
1497 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1498 const void *start
, unsigned int len
)
1500 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1501 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1504 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1507 * pskb_trim_rcsum - trim received skb and update checksum
1508 * @skb: buffer to trim
1511 * This is exactly the same as pskb_trim except that it ensures the
1512 * checksum of received packets are still valid after the operation.
1515 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1517 if (likely(len
>= skb
->len
))
1519 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1520 skb
->ip_summed
= CHECKSUM_NONE
;
1521 return __pskb_trim(skb
, len
);
1524 #define skb_queue_walk(queue, skb) \
1525 for (skb = (queue)->next; \
1526 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1529 #define skb_queue_walk_safe(queue, skb, tmp) \
1530 for (skb = (queue)->next, tmp = skb->next; \
1531 skb != (struct sk_buff *)(queue); \
1532 skb = tmp, tmp = skb->next)
1534 #define skb_queue_reverse_walk(queue, skb) \
1535 for (skb = (queue)->prev; \
1536 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1540 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1541 int noblock
, int *err
);
1542 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1543 struct poll_table_struct
*wait
);
1544 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1545 int offset
, struct iovec
*to
,
1547 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1550 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1551 extern void skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1552 unsigned int flags
);
1553 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1554 int len
, __wsum csum
);
1555 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1557 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1558 const void *from
, int len
);
1559 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1560 int offset
, u8
*to
, int len
,
1562 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1563 extern void skb_split(struct sk_buff
*skb
,
1564 struct sk_buff
*skb1
, const u32 len
);
1566 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1568 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1569 int len
, void *buffer
)
1571 int hlen
= skb_headlen(skb
);
1573 if (hlen
- offset
>= len
)
1574 return skb
->data
+ offset
;
1576 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1582 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1584 const unsigned int len
)
1586 memcpy(to
, skb
->data
, len
);
1589 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1590 const int offset
, void *to
,
1591 const unsigned int len
)
1593 memcpy(to
, skb
->data
+ offset
, len
);
1596 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1598 const unsigned int len
)
1600 memcpy(skb
->data
, from
, len
);
1603 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1606 const unsigned int len
)
1608 memcpy(skb
->data
+ offset
, from
, len
);
1611 extern void skb_init(void);
1614 * skb_get_timestamp - get timestamp from a skb
1615 * @skb: skb to get stamp from
1616 * @stamp: pointer to struct timeval to store stamp in
1618 * Timestamps are stored in the skb as offsets to a base timestamp.
1619 * This function converts the offset back to a struct timeval and stores
1622 static inline void skb_get_timestamp(const struct sk_buff
*skb
, struct timeval
*stamp
)
1624 *stamp
= ktime_to_timeval(skb
->tstamp
);
1627 static inline void __net_timestamp(struct sk_buff
*skb
)
1629 skb
->tstamp
= ktime_get_real();
1632 static inline ktime_t
net_timedelta(ktime_t t
)
1634 return ktime_sub(ktime_get_real(), t
);
1637 static inline ktime_t
net_invalid_timestamp(void)
1639 return ktime_set(0, 0);
1642 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1643 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1645 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1647 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1651 * skb_checksum_complete - Calculate checksum of an entire packet
1652 * @skb: packet to process
1654 * This function calculates the checksum over the entire packet plus
1655 * the value of skb->csum. The latter can be used to supply the
1656 * checksum of a pseudo header as used by TCP/UDP. It returns the
1659 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1660 * this function can be used to verify that checksum on received
1661 * packets. In that case the function should return zero if the
1662 * checksum is correct. In particular, this function will return zero
1663 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1664 * hardware has already verified the correctness of the checksum.
1666 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1668 return skb_csum_unnecessary(skb
) ?
1669 0 : __skb_checksum_complete(skb
);
1672 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1673 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1674 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1676 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1677 nf_conntrack_destroy(nfct
);
1679 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1682 atomic_inc(&nfct
->use
);
1684 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1687 atomic_inc(&skb
->users
);
1689 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1695 #ifdef CONFIG_BRIDGE_NETFILTER
1696 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1698 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1701 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1704 atomic_inc(&nf_bridge
->use
);
1706 #endif /* CONFIG_BRIDGE_NETFILTER */
1707 static inline void nf_reset(struct sk_buff
*skb
)
1709 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1710 nf_conntrack_put(skb
->nfct
);
1712 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1713 skb
->nfct_reasm
= NULL
;
1715 #ifdef CONFIG_BRIDGE_NETFILTER
1716 nf_bridge_put(skb
->nf_bridge
);
1717 skb
->nf_bridge
= NULL
;
1721 /* Note: This doesn't put any conntrack and bridge info in dst. */
1722 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1724 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1725 dst
->nfct
= src
->nfct
;
1726 nf_conntrack_get(src
->nfct
);
1727 dst
->nfctinfo
= src
->nfctinfo
;
1728 dst
->nfct_reasm
= src
->nfct_reasm
;
1729 nf_conntrack_get_reasm(src
->nfct_reasm
);
1731 #ifdef CONFIG_BRIDGE_NETFILTER
1732 dst
->nf_bridge
= src
->nf_bridge
;
1733 nf_bridge_get(src
->nf_bridge
);
1737 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1739 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1740 nf_conntrack_put(dst
->nfct
);
1741 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1743 #ifdef CONFIG_BRIDGE_NETFILTER
1744 nf_bridge_put(dst
->nf_bridge
);
1746 __nf_copy(dst
, src
);
1749 #ifdef CONFIG_NETWORK_SECMARK
1750 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1752 to
->secmark
= from
->secmark
;
1755 static inline void skb_init_secmark(struct sk_buff
*skb
)
1760 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1763 static inline void skb_init_secmark(struct sk_buff
*skb
)
1767 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1769 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1770 skb
->queue_mapping
= queue_mapping
;
1774 static inline u16
skb_get_queue_mapping(struct sk_buff
*skb
)
1776 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1777 return skb
->queue_mapping
;
1783 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1785 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
1786 to
->queue_mapping
= from
->queue_mapping
;
1790 static inline int skb_is_gso(const struct sk_buff
*skb
)
1792 return skb_shinfo(skb
)->gso_size
;
1795 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
1797 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
1800 static inline void skb_forward_csum(struct sk_buff
*skb
)
1802 /* Unfortunately we don't support this one. Any brave souls? */
1803 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1804 skb
->ip_summed
= CHECKSUM_NONE
;
1807 #endif /* __KERNEL__ */
1808 #endif /* _LINUX_SKBUFF_H */