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 * B. Checksumming on output.
69 * NONE: skb is checksummed by protocol or csum is not required.
71 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
72 * from skb->transport_header to the end and to record the checksum
73 * at skb->transport_header + skb->csum.
75 * Device must show its capabilities in dev->features, set
76 * at device setup time.
77 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
79 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
80 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
81 * TCP/UDP over IPv4. Sigh. Vendors like this
82 * way by an unknown reason. Though, see comment above
83 * about CHECKSUM_UNNECESSARY. 8)
85 * Any questions? No questions, good. --ANK
90 struct pipe_inode_info
;
92 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
98 #ifdef CONFIG_BRIDGE_NETFILTER
99 struct nf_bridge_info
{
101 struct net_device
*physindev
;
102 struct net_device
*physoutdev
;
103 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
104 struct net_device
*netoutdev
;
107 unsigned long data
[32 / sizeof(unsigned long)];
111 struct sk_buff_head
{
112 /* These two members must be first. */
113 struct sk_buff
*next
;
114 struct sk_buff
*prev
;
122 /* To allow 64K frame to be packed as single skb without frag_list */
123 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
125 typedef struct skb_frag_struct skb_frag_t
;
127 struct skb_frag_struct
{
133 /* This data is invariant across clones and lives at
134 * the end of the header data, ie. at skb->end.
136 struct skb_shared_info
{
138 unsigned short nr_frags
;
139 unsigned short gso_size
;
140 /* Warning: this field is not always filled in (UFO)! */
141 unsigned short gso_segs
;
142 unsigned short gso_type
;
144 struct sk_buff
*frag_list
;
145 skb_frag_t frags
[MAX_SKB_FRAGS
];
148 /* We divide dataref into two halves. The higher 16 bits hold references
149 * to the payload part of skb->data. The lower 16 bits hold references to
150 * the entire skb->data. A clone of a headerless skb holds the length of
151 * the header in skb->hdr_len.
153 * All users must obey the rule that the skb->data reference count must be
154 * greater than or equal to the payload reference count.
156 * Holding a reference to the payload part means that the user does not
157 * care about modifications to the header part of skb->data.
159 #define SKB_DATAREF_SHIFT 16
160 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
164 SKB_FCLONE_UNAVAILABLE
,
170 SKB_GSO_TCPV4
= 1 << 0,
171 SKB_GSO_UDP
= 1 << 1,
173 /* This indicates the skb is from an untrusted source. */
174 SKB_GSO_DODGY
= 1 << 2,
176 /* This indicates the tcp segment has CWR set. */
177 SKB_GSO_TCP_ECN
= 1 << 3,
179 SKB_GSO_TCPV6
= 1 << 4,
182 #if BITS_PER_LONG > 32
183 #define NET_SKBUFF_DATA_USES_OFFSET 1
186 #ifdef NET_SKBUFF_DATA_USES_OFFSET
187 typedef unsigned int sk_buff_data_t
;
189 typedef unsigned char *sk_buff_data_t
;
193 * struct sk_buff - socket buffer
194 * @next: Next buffer in list
195 * @prev: Previous buffer in list
196 * @sk: Socket we are owned by
197 * @tstamp: Time we arrived
198 * @dev: Device we arrived on/are leaving by
199 * @iif: ifindex of device we arrived on
200 * @transport_header: Transport layer header
201 * @network_header: Network layer header
202 * @mac_header: Link layer header
203 * @dst: destination entry
204 * @sp: the security path, used for xfrm
205 * @cb: Control buffer. Free for use by every layer. Put private vars here
206 * @len: Length of actual data
207 * @data_len: Data length
208 * @mac_len: Length of link layer header
209 * @hdr_len: writable header length of cloned skb
210 * @csum: Checksum (must include start/offset pair)
211 * @csum_start: Offset from skb->head where checksumming should start
212 * @csum_offset: Offset from csum_start where checksum should be stored
213 * @local_df: allow local fragmentation
214 * @cloned: Head may be cloned (check refcnt to be sure)
215 * @nohdr: Payload reference only, must not modify header
216 * @pkt_type: Packet class
217 * @fclone: skbuff clone status
218 * @ip_summed: Driver fed us an IP checksum
219 * @priority: Packet queueing priority
220 * @users: User count - see {datagram,tcp}.c
221 * @protocol: Packet protocol from driver
222 * @truesize: Buffer size
223 * @head: Head of buffer
224 * @data: Data head pointer
225 * @tail: Tail pointer
227 * @destructor: Destruct function
228 * @mark: Generic packet mark
229 * @nfct: Associated connection, if any
230 * @ipvs_property: skbuff is owned by ipvs
231 * @nfctinfo: Relationship of this skb to the connection
232 * @nfct_reasm: netfilter conntrack re-assembly pointer
233 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
234 * @tc_index: Traffic control index
235 * @tc_verd: traffic control verdict
236 * @dma_cookie: a cookie to one of several possible DMA operations
237 * done by skb DMA functions
238 * @secmark: security marking
242 /* These two members must be first. */
243 struct sk_buff
*next
;
244 struct sk_buff
*prev
;
248 struct net_device
*dev
;
250 /* 4 byte hole on 64 bit*/
252 struct dst_entry
*dst
;
256 * This is the control buffer. It is free to use for every
257 * layer. Please put your private variables there. If you
258 * want to keep them across layers you have to do a skb_clone()
259 * first. This is owned by whoever has the skb queued ATM.
285 void (*destructor
)(struct sk_buff
*skb
);
286 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
287 struct nf_conntrack
*nfct
;
288 struct sk_buff
*nfct_reasm
;
290 #ifdef CONFIG_BRIDGE_NETFILTER
291 struct nf_bridge_info
*nf_bridge
;
293 #ifdef CONFIG_NET_SCHED
294 __u16 tc_index
; /* traffic control index */
295 //#ifdef CONFIG_NET_CLS_ACT
296 __u16 tc_verd
; /* traffic control verdict */
299 #ifdef CONFIG_NET_DMA
300 dma_cookie_t dma_cookie
;
302 #ifdef CONFIG_NETWORK_SECMARK
308 sk_buff_data_t transport_header
;
309 sk_buff_data_t network_header
;
310 sk_buff_data_t mac_header
;
311 /* These elements must be at the end, see alloc_skb() for details. */
316 unsigned int truesize
;
318 unsigned char wl_idx
; /* Jiahao: index of wireless interface */
319 #if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
320 unsigned char imq_flags
;
321 struct nf_info
*nf_info
;
323 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
331 * Handling routines are only of interest to the kernel
333 #include <linux/slab.h>
335 #include <asm/system.h>
337 extern void kfree_skb(struct sk_buff
*skb
);
338 extern void __kfree_skb(struct sk_buff
*skb
);
339 extern struct sk_buff
*__alloc_skb(unsigned int size
,
340 gfp_t priority
, int fclone
, int node
);
341 static inline struct sk_buff
*alloc_skb(unsigned int size
,
344 return __alloc_skb(size
, priority
, 0, -1);
347 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
350 return __alloc_skb(size
, priority
, 1, -1);
353 extern void kfree_skbmem(struct sk_buff
*skb
);
354 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
356 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
358 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
360 extern int pskb_expand_head(struct sk_buff
*skb
,
361 int nhead
, int ntail
,
363 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
364 unsigned int headroom
);
365 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
366 int newheadroom
, int newtailroom
,
368 extern int skb_to_sgvec(struct sk_buff
*skb
,
369 struct scatterlist
*sg
, int offset
,
371 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
372 struct sk_buff
**trailer
);
373 extern int skb_pad(struct sk_buff
*skb
, int pad
);
374 #define dev_kfree_skb(a) kfree_skb(a)
375 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
377 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
379 extern void skb_truesize_bug(struct sk_buff
*skb
);
381 static inline void skb_truesize_check(struct sk_buff
*skb
)
383 if (unlikely((int)skb
->truesize
< sizeof(struct sk_buff
) + skb
->len
))
384 skb_truesize_bug(skb
);
387 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
388 int getfrag(void *from
, char *to
, int offset
,
389 int len
,int odd
, struct sk_buff
*skb
),
390 void *from
, int length
);
397 __u32 stepped_offset
;
398 struct sk_buff
*root_skb
;
399 struct sk_buff
*cur_skb
;
403 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
404 unsigned int from
, unsigned int to
,
405 struct skb_seq_state
*st
);
406 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
407 struct skb_seq_state
*st
);
408 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
410 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
411 unsigned int to
, struct ts_config
*config
,
412 struct ts_state
*state
);
414 #ifdef NET_SKBUFF_DATA_USES_OFFSET
415 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
417 return skb
->head
+ skb
->end
;
420 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
427 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
430 * skb_queue_empty - check if a queue is empty
433 * Returns true if the queue is empty, false otherwise.
435 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
437 return list
->next
== (struct sk_buff
*)list
;
441 * skb_get - reference buffer
442 * @skb: buffer to reference
444 * Makes another reference to a socket buffer and returns a pointer
447 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
449 atomic_inc(&skb
->users
);
454 * If users == 1, we are the only owner and are can avoid redundant
459 * skb_cloned - is the buffer a clone
460 * @skb: buffer to check
462 * Returns true if the buffer was generated with skb_clone() and is
463 * one of multiple shared copies of the buffer. Cloned buffers are
464 * shared data so must not be written to under normal circumstances.
466 static inline int skb_cloned(const struct sk_buff
*skb
)
468 return skb
->cloned
&&
469 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
473 * skb_header_cloned - is the header a clone
474 * @skb: buffer to check
476 * Returns true if modifying the header part of the buffer requires
477 * the data to be copied.
479 static inline int skb_header_cloned(const struct sk_buff
*skb
)
486 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
487 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
492 * skb_header_release - release reference to header
493 * @skb: buffer to operate on
495 * Drop a reference to the header part of the buffer. This is done
496 * by acquiring a payload reference. You must not read from the header
497 * part of skb->data after this.
499 static inline void skb_header_release(struct sk_buff
*skb
)
503 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
507 * skb_shared - is the buffer shared
508 * @skb: buffer to check
510 * Returns true if more than one person has a reference to this
513 static inline int skb_shared(const struct sk_buff
*skb
)
515 return atomic_read(&skb
->users
) != 1;
519 * skb_share_check - check if buffer is shared and if so clone it
520 * @skb: buffer to check
521 * @pri: priority for memory allocation
523 * If the buffer is shared the buffer is cloned and the old copy
524 * drops a reference. A new clone with a single reference is returned.
525 * If the buffer is not shared the original buffer is returned. When
526 * being called from interrupt status or with spinlocks held pri must
529 * NULL is returned on a memory allocation failure.
531 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
534 might_sleep_if(pri
& __GFP_WAIT
);
535 if (skb_shared(skb
)) {
536 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
544 * Copy shared buffers into a new sk_buff. We effectively do COW on
545 * packets to handle cases where we have a local reader and forward
546 * and a couple of other messy ones. The normal one is tcpdumping
547 * a packet thats being forwarded.
551 * skb_unshare - make a copy of a shared buffer
552 * @skb: buffer to check
553 * @pri: priority for memory allocation
555 * If the socket buffer is a clone then this function creates a new
556 * copy of the data, drops a reference count on the old copy and returns
557 * the new copy with the reference count at 1. If the buffer is not a clone
558 * the original buffer is returned. When called with a spinlock held or
559 * from interrupt state @pri must be %GFP_ATOMIC
561 * %NULL is returned on a memory allocation failure.
563 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
566 might_sleep_if(pri
& __GFP_WAIT
);
567 if (skb_cloned(skb
)) {
568 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
569 kfree_skb(skb
); /* Free our shared copy */
577 * @list_: list to peek at
579 * Peek an &sk_buff. Unlike most other operations you _MUST_
580 * be careful with this one. A peek leaves the buffer on the
581 * list and someone else may run off with it. You must hold
582 * the appropriate locks or have a private queue to do this.
584 * Returns %NULL for an empty list or a pointer to the head element.
585 * The reference count is not incremented and the reference is therefore
586 * volatile. Use with caution.
588 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
590 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
591 if (list
== (struct sk_buff
*)list_
)
598 * @list_: list to peek at
600 * Peek an &sk_buff. Unlike most other operations you _MUST_
601 * be careful with this one. A peek leaves the buffer on the
602 * list and someone else may run off with it. You must hold
603 * the appropriate locks or have a private queue to do this.
605 * Returns %NULL for an empty list or a pointer to the tail element.
606 * The reference count is not incremented and the reference is therefore
607 * volatile. Use with caution.
609 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
611 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
612 if (list
== (struct sk_buff
*)list_
)
618 * skb_queue_len - get queue length
619 * @list_: list to measure
621 * Return the length of an &sk_buff queue.
623 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
629 * This function creates a split out lock class for each invocation;
630 * this is needed for now since a whole lot of users of the skb-queue
631 * infrastructure in drivers have different locking usage (in hardirq)
632 * than the networking core (in softirq only). In the long run either the
633 * network layer or drivers should need annotation to consolidate the
634 * main types of usage into 3 classes.
636 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
638 spin_lock_init(&list
->lock
);
639 list
->prev
= list
->next
= (struct sk_buff
*)list
;
643 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
644 struct lock_class_key
*class)
646 skb_queue_head_init(list
);
647 lockdep_set_class(&list
->lock
, class);
651 * Insert an sk_buff at the start of a list.
653 * The "__skb_xxxx()" functions are the non-atomic ones that
654 * can only be called with interrupts disabled.
658 * __skb_queue_after - queue a buffer at the list head
660 * @prev: place after this buffer
661 * @newsk: buffer to queue
663 * Queue a buffer int the middle of a list. This function takes no locks
664 * and you must therefore hold required locks before calling it.
666 * A buffer cannot be placed on two lists at the same time.
668 static inline void __skb_queue_after(struct sk_buff_head
*list
,
669 struct sk_buff
*prev
,
670 struct sk_buff
*newsk
)
672 struct sk_buff
*next
;
678 next
->prev
= prev
->next
= newsk
;
682 * __skb_queue_head - queue a buffer at the list head
684 * @newsk: buffer to queue
686 * Queue a buffer at the start of a list. This function takes no locks
687 * and you must therefore hold required locks before calling it.
689 * A buffer cannot be placed on two lists at the same time.
691 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
692 static inline void __skb_queue_head(struct sk_buff_head
*list
,
693 struct sk_buff
*newsk
)
695 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
699 * __skb_queue_tail - queue a buffer at the list tail
701 * @newsk: buffer to queue
703 * Queue a buffer at the end of a list. This function takes no locks
704 * and you must therefore hold required locks before calling it.
706 * A buffer cannot be placed on two lists at the same time.
708 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
709 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
710 struct sk_buff
*newsk
)
712 struct sk_buff
*prev
, *next
;
715 next
= (struct sk_buff
*)list
;
719 next
->prev
= prev
->next
= newsk
;
724 * __skb_dequeue - remove from the head of the queue
725 * @list: list to dequeue from
727 * Remove the head of the list. This function does not take any locks
728 * so must be used with appropriate locks held only. The head item is
729 * returned or %NULL if the list is empty.
731 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
732 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
734 struct sk_buff
*next
, *prev
, *result
;
736 prev
= (struct sk_buff
*) list
;
745 result
->next
= result
->prev
= NULL
;
752 * Insert a packet on a list.
754 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
755 static inline void __skb_insert(struct sk_buff
*newsk
,
756 struct sk_buff
*prev
, struct sk_buff
*next
,
757 struct sk_buff_head
*list
)
761 next
->prev
= prev
->next
= newsk
;
766 * Place a packet after a given packet in a list.
768 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
769 static inline void __skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
771 __skb_insert(newsk
, old
, old
->next
, list
);
775 * remove sk_buff from list. _Must_ be called atomically, and with
778 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
779 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
781 struct sk_buff
*next
, *prev
;
786 skb
->next
= skb
->prev
= NULL
;
792 /* XXX: more streamlined implementation */
795 * __skb_dequeue_tail - remove from the tail of the queue
796 * @list: list to dequeue from
798 * Remove the tail of the list. This function does not take any locks
799 * so must be used with appropriate locks held only. The tail item is
800 * returned or %NULL if the list is empty.
802 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
803 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
805 struct sk_buff
*skb
= skb_peek_tail(list
);
807 __skb_unlink(skb
, list
);
812 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
814 return skb
->data_len
;
817 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
819 return skb
->len
- skb
->data_len
;
822 static inline int skb_pagelen(const struct sk_buff
*skb
)
826 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
827 len
+= skb_shinfo(skb
)->frags
[i
].size
;
828 return len
+ skb_headlen(skb
);
831 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
832 struct page
*page
, int off
, int size
)
834 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
837 frag
->page_offset
= off
;
839 skb_shinfo(skb
)->nr_frags
= i
+ 1;
842 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
843 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
844 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
846 #ifdef NET_SKBUFF_DATA_USES_OFFSET
847 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
849 return skb
->head
+ skb
->tail
;
852 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
854 skb
->tail
= skb
->data
- skb
->head
;
857 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
859 skb_reset_tail_pointer(skb
);
862 #else /* NET_SKBUFF_DATA_USES_OFFSET */
863 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
868 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
870 skb
->tail
= skb
->data
;
873 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
875 skb
->tail
= skb
->data
+ offset
;
878 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
881 * Add data to an sk_buff
883 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
885 unsigned char *tmp
= skb_tail_pointer(skb
);
886 SKB_LINEAR_ASSERT(skb
);
893 * skb_put - add data to a buffer
894 * @skb: buffer to use
895 * @len: amount of data to add
897 * This function extends the used data area of the buffer. If this would
898 * exceed the total buffer size the kernel will panic. A pointer to the
899 * first byte of the extra data is returned.
901 static inline unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
)
903 unsigned char *tmp
= skb_tail_pointer(skb
);
904 SKB_LINEAR_ASSERT(skb
);
907 if (unlikely(skb
->tail
> skb
->end
))
908 skb_over_panic(skb
, len
, current_text_addr());
912 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
920 * skb_push - add data to the start of a buffer
921 * @skb: buffer to use
922 * @len: amount of data to add
924 * This function extends the used data area of the buffer at the buffer
925 * start. If this would exceed the total buffer headroom the kernel will
926 * panic. A pointer to the first byte of the extra data is returned.
928 static inline unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
)
932 if (unlikely(skb
->data
<skb
->head
))
933 skb_under_panic(skb
, len
, current_text_addr());
937 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
940 BUG_ON(skb
->len
< skb
->data_len
);
941 return skb
->data
+= len
;
945 * skb_pull - remove data from the start of a buffer
946 * @skb: buffer to use
947 * @len: amount of data to remove
949 * This function removes data from the start of a buffer, returning
950 * the memory to the headroom. A pointer to the next data in the buffer
951 * is returned. Once the data has been pulled future pushes will overwrite
954 static inline unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
)
956 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
959 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
961 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
963 if (len
> skb_headlen(skb
) &&
964 !__pskb_pull_tail(skb
, len
-skb_headlen(skb
)))
967 return skb
->data
+= len
;
970 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
972 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
975 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
977 if (likely(len
<= skb_headlen(skb
)))
979 if (unlikely(len
> skb
->len
))
981 return __pskb_pull_tail(skb
, len
-skb_headlen(skb
)) != NULL
;
985 * skb_headroom - bytes at buffer head
986 * @skb: buffer to check
988 * Return the number of bytes of free space at the head of an &sk_buff.
990 static inline int skb_headroom(const struct sk_buff
*skb
)
992 return skb
->data
- skb
->head
;
996 * skb_tailroom - bytes at buffer end
997 * @skb: buffer to check
999 * Return the number of bytes of free space at the tail of an sk_buff
1001 static inline int skb_tailroom(const struct sk_buff
*skb
)
1003 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1007 * skb_reserve - adjust headroom
1008 * @skb: buffer to alter
1009 * @len: bytes to move
1011 * Increase the headroom of an empty &sk_buff by reducing the tail
1012 * room. This is only allowed for an empty buffer.
1014 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1020 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1021 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1023 return skb
->head
+ skb
->transport_header
;
1026 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1028 skb
->transport_header
= skb
->data
- skb
->head
;
1031 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1034 skb_reset_transport_header(skb
);
1035 skb
->transport_header
+= offset
;
1038 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1040 return skb
->head
+ skb
->network_header
;
1043 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1045 skb
->network_header
= skb
->data
- skb
->head
;
1048 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1050 skb_reset_network_header(skb
);
1051 skb
->network_header
+= offset
;
1054 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1056 return skb
->head
+ skb
->mac_header
;
1059 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1061 return skb
->mac_header
!= ~0U;
1064 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1066 skb
->mac_header
= skb
->data
- skb
->head
;
1069 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1071 skb_reset_mac_header(skb
);
1072 skb
->mac_header
+= offset
;
1075 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1077 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1079 return skb
->transport_header
;
1082 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1084 skb
->transport_header
= skb
->data
;
1087 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1090 skb
->transport_header
= skb
->data
+ offset
;
1093 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1095 return skb
->network_header
;
1098 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1100 skb
->network_header
= skb
->data
;
1103 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1105 skb
->network_header
= skb
->data
+ offset
;
1108 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1110 return skb
->mac_header
;
1113 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1115 return skb
->mac_header
!= NULL
;
1118 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1120 skb
->mac_header
= skb
->data
;
1123 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1125 skb
->mac_header
= skb
->data
+ offset
;
1127 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1129 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1131 return skb_transport_header(skb
) - skb
->data
;
1134 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1136 return skb
->transport_header
- skb
->network_header
;
1139 static inline int skb_network_offset(const struct sk_buff
*skb
)
1141 return skb_network_header(skb
) - skb
->data
;
1145 * CPUs often take a performance hit when accessing unaligned memory
1146 * locations. The actual performance hit varies, it can be small if the
1147 * hardware handles it or large if we have to take an exception and fix it
1150 * Since an ethernet header is 14 bytes network drivers often end up with
1151 * the IP header at an unaligned offset. The IP header can be aligned by
1152 * shifting the start of the packet by 2 bytes. Drivers should do this
1155 * skb_reserve(NET_IP_ALIGN);
1157 * The downside to this alignment of the IP header is that the DMA is now
1158 * unaligned. On some architectures the cost of an unaligned DMA is high
1159 * and this cost outweighs the gains made by aligning the IP header.
1161 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1164 #ifndef NET_IP_ALIGN
1165 #define NET_IP_ALIGN 2
1169 * The networking layer reserves some headroom in skb data (via
1170 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1171 * the header has to grow. In the default case, if the header has to grow
1172 * 32 bytes or less we avoid the reallocation.
1174 * Unfortunately this headroom changes the DMA alignment of the resulting
1175 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1176 * on some architectures. An architecture can override this value,
1177 * perhaps setting it to a cacheline in size (since that will maintain
1178 * cacheline alignment of the DMA). It must be a power of 2.
1180 * Various parts of the networking layer expect at least 32 bytes of
1181 * headroom, you should not reduce this.
1183 * This has been changed to 64 to acommodate for routing between ethernet
1184 * and wireless, but only for new allocations
1187 #define NET_SKB_PAD 32
1190 #ifndef NET_SKB_PAD_ALLOC
1191 #define NET_SKB_PAD_ALLOC 64
1194 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1196 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1198 if (unlikely(skb
->data_len
)) {
1203 skb_set_tail_pointer(skb
, len
);
1207 * skb_trim - remove end from a buffer
1208 * @skb: buffer to alter
1211 * Cut the length of a buffer down by removing data from the tail. If
1212 * the buffer is already under the length specified it is not modified.
1213 * The skb must be linear.
1215 static inline void skb_trim(struct sk_buff
*skb
, unsigned int len
)
1218 __skb_trim(skb
, len
);
1222 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1225 return ___pskb_trim(skb
, len
);
1226 __skb_trim(skb
, len
);
1230 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1232 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1236 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1237 * @skb: buffer to alter
1240 * This is identical to pskb_trim except that the caller knows that
1241 * the skb is not cloned so we should never get an error due to out-
1244 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1246 int err
= pskb_trim(skb
, len
);
1251 * skb_orphan - orphan a buffer
1252 * @skb: buffer to orphan
1254 * If a buffer currently has an owner then we call the owner's
1255 * destructor function and make the @skb unowned. The buffer continues
1256 * to exist but is no longer charged to its former owner.
1258 static inline void skb_orphan(struct sk_buff
*skb
)
1260 if (skb
->destructor
)
1261 skb
->destructor(skb
);
1262 skb
->destructor
= NULL
;
1267 * __skb_queue_purge - empty a list
1268 * @list: list to empty
1270 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1271 * the list and one reference dropped. This function does not take the
1272 * list lock and the caller must hold the relevant locks to use it.
1274 extern void skb_queue_purge(struct sk_buff_head
*list
);
1275 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1277 struct sk_buff
*skb
;
1278 while ((skb
= __skb_dequeue(list
)) != NULL
)
1283 * __dev_alloc_skb - allocate an skbuff for receiving
1284 * @length: length to allocate
1285 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1287 * Allocate a new &sk_buff and assign it a usage count of one. The
1288 * buffer has unspecified headroom built in. Users should allocate
1289 * the headroom they think they need without accounting for the
1290 * built in space. The built in space is used for optimisations.
1292 * %NULL is returned if there is no free memory.
1294 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1297 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD_ALLOC
, gfp_mask
);
1299 skb_reserve(skb
, NET_SKB_PAD_ALLOC
);
1304 * dev_alloc_skb - allocate an skbuff for receiving
1305 * @length: length to allocate
1307 * Allocate a new &sk_buff and assign it a usage count of one. The
1308 * buffer has unspecified headroom built in. Users should allocate
1309 * the headroom they think they need without accounting for the
1310 * built in space. The built in space is used for optimisations.
1312 * %NULL is returned if there is no free memory. Although this function
1313 * allocates memory it can be called from an interrupt.
1315 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1317 return __dev_alloc_skb(length
, GFP_ATOMIC
);
1320 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1321 unsigned int length
, gfp_t gfp_mask
);
1324 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1325 * @dev: network device to receive on
1326 * @length: length to allocate
1328 * Allocate a new &sk_buff and assign it a usage count of one. The
1329 * buffer has unspecified headroom built in. Users should allocate
1330 * the headroom they think they need without accounting for the
1331 * built in space. The built in space is used for optimisations.
1333 * %NULL is returned if there is no free memory. Although this function
1334 * allocates memory it can be called from an interrupt.
1336 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1337 unsigned int length
)
1339 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1343 * skb_clone_writable - is the header of a clone writable
1344 * @skb: buffer to check
1345 * @len: length up to which to write
1347 * Returns true if modifying the header part of the cloned buffer
1348 * does not requires the data to be copied.
1350 static inline int skb_clone_writable(struct sk_buff
*skb
, int len
)
1352 return !skb_header_cloned(skb
) &&
1353 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1356 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1361 if (headroom
< NET_SKB_PAD
)
1362 headroom
= NET_SKB_PAD
;
1363 if (headroom
> skb_headroom(skb
))
1364 delta
= headroom
- skb_headroom(skb
);
1366 if (delta
|| cloned
)
1367 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD_ALLOC
), 0,
1373 * skb_cow - copy header of skb when it is required
1374 * @skb: buffer to cow
1375 * @headroom: needed headroom
1377 * If the skb passed lacks sufficient headroom or its data part
1378 * is shared, data is reallocated. If reallocation fails, an error
1379 * is returned and original skb is not changed.
1381 * The result is skb with writable area skb->head...skb->tail
1382 * and at least @headroom of space at head.
1384 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1386 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1390 * skb_cow_head - skb_cow but only making the head writable
1391 * @skb: buffer to cow
1392 * @headroom: needed headroom
1394 * This function is identical to skb_cow except that we replace the
1395 * skb_cloned check by skb_header_cloned. It should be used when
1396 * you only need to push on some header and do not need to modify
1399 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1401 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1405 * skb_padto - pad an skbuff up to a minimal size
1406 * @skb: buffer to pad
1407 * @len: minimal length
1409 * Pads up a buffer to ensure the trailing bytes exist and are
1410 * blanked. If the buffer already contains sufficient data it
1411 * is untouched. Otherwise it is extended. Returns zero on
1412 * success. The skb is freed on error.
1415 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1417 unsigned int size
= skb
->len
;
1418 if (likely(size
>= len
))
1420 return skb_pad(skb
, len
-size
);
1423 static inline int skb_add_data(struct sk_buff
*skb
,
1424 char __user
*from
, int copy
)
1426 const int off
= skb
->len
;
1428 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1430 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1433 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1436 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1439 __skb_trim(skb
, off
);
1443 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1444 struct page
*page
, int off
)
1447 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1449 return page
== frag
->page
&&
1450 off
== frag
->page_offset
+ frag
->size
;
1455 static inline int __skb_linearize(struct sk_buff
*skb
)
1457 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1461 * skb_linearize - convert paged skb to linear one
1462 * @skb: buffer to linarize
1464 * If there is no free memory -ENOMEM is returned, otherwise zero
1465 * is returned and the old skb data released.
1467 static inline int skb_linearize(struct sk_buff
*skb
)
1469 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1473 * skb_linearize_cow - make sure skb is linear and writable
1474 * @skb: buffer to process
1476 * If there is no free memory -ENOMEM is returned, otherwise zero
1477 * is returned and the old skb data released.
1479 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1481 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1482 __skb_linearize(skb
) : 0;
1486 * skb_postpull_rcsum - update checksum for received skb after pull
1487 * @skb: buffer to update
1488 * @start: start of data before pull
1489 * @len: length of data pulled
1491 * After doing a pull on a received packet, you need to call this to
1492 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1493 * CHECKSUM_NONE so that it can be recomputed from scratch.
1496 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1497 const void *start
, unsigned int len
)
1499 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1500 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1503 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1506 * pskb_trim_rcsum - trim received skb and update checksum
1507 * @skb: buffer to trim
1510 * This is exactly the same as pskb_trim except that it ensures the
1511 * checksum of received packets are still valid after the operation.
1514 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1516 if (likely(len
>= skb
->len
))
1518 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1519 skb
->ip_summed
= CHECKSUM_NONE
;
1520 return __pskb_trim(skb
, len
);
1523 #define skb_queue_walk(queue, skb) \
1524 for (skb = (queue)->next; \
1525 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1528 #define skb_queue_walk_safe(queue, skb, tmp) \
1529 for (skb = (queue)->next, tmp = skb->next; \
1530 skb != (struct sk_buff *)(queue); \
1531 skb = tmp, tmp = skb->next)
1533 #define skb_queue_reverse_walk(queue, skb) \
1534 for (skb = (queue)->prev; \
1535 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1539 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1540 int noblock
, int *err
);
1541 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1542 struct poll_table_struct
*wait
);
1543 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1544 int offset
, struct iovec
*to
,
1546 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1549 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1550 extern void skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1551 unsigned int flags
);
1552 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1553 int len
, __wsum csum
);
1554 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1556 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1557 const void *from
, int len
);
1558 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1559 int offset
, u8
*to
, int len
,
1561 extern int skb_splice_bits(struct sk_buff
*skb
,
1562 unsigned int offset
,
1563 struct pipe_inode_info
*pipe
,
1565 unsigned int flags
);
1566 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1567 extern void skb_split(struct sk_buff
*skb
,
1568 struct sk_buff
*skb1
, const u32 len
);
1570 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1572 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1573 int len
, void *buffer
)
1575 int hlen
= skb_headlen(skb
);
1577 if (hlen
- offset
>= len
)
1578 return skb
->data
+ offset
;
1580 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1586 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1588 const unsigned int len
)
1590 memcpy(to
, skb
->data
, len
);
1593 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1594 const int offset
, void *to
,
1595 const unsigned int len
)
1597 memcpy(to
, skb
->data
+ offset
, len
);
1600 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1602 const unsigned int len
)
1604 memcpy(skb
->data
, from
, len
);
1607 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1610 const unsigned int len
)
1612 memcpy(skb
->data
+ offset
, from
, len
);
1615 extern void skb_init(void);
1618 * skb_get_timestamp - get timestamp from a skb
1619 * @skb: skb to get stamp from
1620 * @stamp: pointer to struct timeval to store stamp in
1622 * Timestamps are stored in the skb as offsets to a base timestamp.
1623 * This function converts the offset back to a struct timeval and stores
1626 static inline void skb_get_timestamp(const struct sk_buff
*skb
, struct timeval
*stamp
)
1628 *stamp
= ktime_to_timeval(skb
->tstamp
);
1631 static inline void __net_timestamp(struct sk_buff
*skb
)
1633 skb
->tstamp
= ktime_get_real();
1636 static inline ktime_t
net_timedelta(ktime_t t
)
1638 return ktime_sub(ktime_get_real(), t
);
1641 static inline ktime_t
net_invalid_timestamp(void)
1643 return ktime_set(0, 0);
1646 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1647 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1649 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1651 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1655 * skb_checksum_complete - Calculate checksum of an entire packet
1656 * @skb: packet to process
1658 * This function calculates the checksum over the entire packet plus
1659 * the value of skb->csum. The latter can be used to supply the
1660 * checksum of a pseudo header as used by TCP/UDP. It returns the
1663 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1664 * this function can be used to verify that checksum on received
1665 * packets. In that case the function should return zero if the
1666 * checksum is correct. In particular, this function will return zero
1667 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1668 * hardware has already verified the correctness of the checksum.
1670 static inline unsigned int skb_checksum_complete(struct sk_buff
*skb
)
1672 return skb_csum_unnecessary(skb
) ?
1673 0 : __skb_checksum_complete(skb
);
1676 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1677 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1678 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1680 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1681 nf_conntrack_destroy(nfct
);
1683 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1686 atomic_inc(&nfct
->use
);
1688 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1691 atomic_inc(&skb
->users
);
1693 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1699 #ifdef CONFIG_BRIDGE_NETFILTER
1700 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1702 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1705 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1708 atomic_inc(&nf_bridge
->use
);
1710 #endif /* CONFIG_BRIDGE_NETFILTER */
1711 static inline void nf_reset(struct sk_buff
*skb
)
1713 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1714 nf_conntrack_put(skb
->nfct
);
1716 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1717 skb
->nfct_reasm
= NULL
;
1719 #ifdef CONFIG_BRIDGE_NETFILTER
1720 nf_bridge_put(skb
->nf_bridge
);
1721 skb
->nf_bridge
= NULL
;
1725 /* Note: This doesn't put any conntrack and bridge info in dst. */
1726 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1728 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1729 dst
->nfct
= src
->nfct
;
1730 nf_conntrack_get(src
->nfct
);
1731 dst
->nfctinfo
= src
->nfctinfo
;
1732 dst
->nfct_reasm
= src
->nfct_reasm
;
1733 nf_conntrack_get_reasm(src
->nfct_reasm
);
1735 #ifdef CONFIG_BRIDGE_NETFILTER
1736 dst
->nf_bridge
= src
->nf_bridge
;
1737 nf_bridge_get(src
->nf_bridge
);
1739 #if defined(CONFIG_IMQ) || defined(CONFIG_IMQ_MODULE)
1740 dst
->imq_flags
= src
->imq_flags
;
1741 dst
->nf_info
= src
->nf_info
;
1745 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1747 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1748 nf_conntrack_put(dst
->nfct
);
1749 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1751 #ifdef CONFIG_BRIDGE_NETFILTER
1752 nf_bridge_put(dst
->nf_bridge
);
1754 __nf_copy(dst
, src
);
1757 #ifdef CONFIG_NETWORK_SECMARK
1758 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1760 to
->secmark
= from
->secmark
;
1763 static inline void skb_init_secmark(struct sk_buff
*skb
)
1768 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1771 static inline void skb_init_secmark(struct sk_buff
*skb
)
1775 static inline int skb_is_gso(const struct sk_buff
*skb
)
1777 return skb_shinfo(skb
)->gso_size
;
1780 static inline void skb_forward_csum(struct sk_buff
*skb
)
1782 /* Unfortunately we don't support this one. Any brave souls? */
1783 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1784 skb
->ip_summed
= CHECKSUM_NONE
;
1787 #endif /* __KERNEL__ */
1788 #endif /* _LINUX_SKBUFF_H */