2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/compiler.h>
19 #include <linux/time.h>
20 #include <linux/cache.h>
22 #include <asm/atomic.h>
23 #include <asm/types.h>
24 #include <linux/spinlock.h>
25 #include <linux/net.h>
26 #include <linux/textsearch.h>
27 #include <net/checksum.h>
28 #include <linux/rcupdate.h>
29 #include <linux/dmaengine.h>
30 #include <linux/hrtimer.h>
32 /* Don't change this without changing skb_csum_unnecessary! */
33 #define CHECKSUM_NONE 0
34 #define CHECKSUM_UNNECESSARY 1
35 #define CHECKSUM_COMPLETE 2
36 #define CHECKSUM_PARTIAL 3
38 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
39 ~(SMP_CACHE_BYTES - 1))
40 #define SKB_WITH_OVERHEAD(X) \
41 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
42 #define SKB_MAX_ORDER(X, ORDER) \
43 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
44 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
45 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
47 /* A. Checksumming of received packets by device.
49 * NONE: device failed to checksum this packet.
50 * skb->csum is undefined.
52 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
53 * skb->csum is undefined.
54 * It is bad option, but, unfortunately, many of vendors do this.
55 * Apparently with secret goal to sell you new device, when you
56 * will add new protocol to your host. F.e. IPv6. 8)
58 * COMPLETE: the most generic way. Device supplied checksum of _all_
59 * the packet as seen by netif_rx in skb->csum.
60 * NOTE: Even if device supports only some protocols, but
61 * is able to produce some skb->csum, it MUST use COMPLETE,
64 * PARTIAL: identical to the case for output below. This may occur
65 * on a packet received directly from another Linux OS, e.g.,
66 * a virtualised Linux kernel on the same host. The packet can
67 * be treated in the same way as UNNECESSARY except that on
68 * output (i.e., forwarding) the checksum must be filled in
69 * by the OS or the hardware.
71 * B. Checksumming on output.
73 * NONE: skb is checksummed by protocol or csum is not required.
75 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
76 * from skb->csum_start to the end and to record the checksum
77 * at skb->csum_start + skb->csum_offset.
79 * Device must show its capabilities in dev->features, set
80 * at device setup time.
81 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
83 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
84 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
85 * TCP/UDP over IPv4. Sigh. Vendors like this
86 * way by an unknown reason. Though, see comment above
87 * about CHECKSUM_UNNECESSARY. 8)
88 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
90 * Any questions? No questions, good. --ANK
95 struct pipe_inode_info
;
97 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
103 #ifdef CONFIG_BRIDGE_NETFILTER
104 struct nf_bridge_info
{
106 struct net_device
*physindev
;
107 struct net_device
*physoutdev
;
109 unsigned long data
[32 / sizeof(unsigned long)];
113 struct sk_buff_head
{
114 /* These two members must be first. */
115 struct sk_buff
*next
;
116 struct sk_buff
*prev
;
124 /* To allow 64K frame to be packed as single skb without frag_list */
125 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
127 typedef struct skb_frag_struct skb_frag_t
;
129 struct skb_frag_struct
{
135 #define HAVE_HW_TIME_STAMP
138 * struct skb_shared_hwtstamps - hardware time stamps
139 * @hwtstamp: hardware time stamp transformed into duration
140 * since arbitrary point in time
141 * @syststamp: hwtstamp transformed to system time base
143 * Software time stamps generated by ktime_get_real() are stored in
144 * skb->tstamp. The relation between the different kinds of time
145 * stamps is as follows:
147 * syststamp and tstamp can be compared against each other in
148 * arbitrary combinations. The accuracy of a
149 * syststamp/tstamp/"syststamp from other device" comparison is
150 * limited by the accuracy of the transformation into system time
151 * base. This depends on the device driver and its underlying
154 * hwtstamps can only be compared against other hwtstamps from
157 * This structure is attached to packets as part of the
158 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
160 struct skb_shared_hwtstamps
{
166 * struct skb_shared_tx - instructions for time stamping of outgoing packets
167 * @hardware: generate hardware time stamp
168 * @software: generate software time stamp
169 * @in_progress: device driver is going to provide
170 * hardware time stamp
172 * These flags are attached to packets as part of the
173 * &skb_shared_info. Use skb_tx() to get a pointer.
175 union skb_shared_tx
{
184 /* This data is invariant across clones and lives at
185 * the end of the header data, ie. at skb->end.
187 struct skb_shared_info
{
189 unsigned short nr_frags
;
190 unsigned short gso_size
;
191 /* Warning: this field is not always filled in (UFO)! */
192 unsigned short gso_segs
;
193 unsigned short gso_type
;
195 union skb_shared_tx tx_flags
;
196 #ifdef CONFIG_HAS_DMA
197 unsigned int num_dma_maps
;
199 struct sk_buff
*frag_list
;
200 struct skb_shared_hwtstamps hwtstamps
;
201 skb_frag_t frags
[MAX_SKB_FRAGS
];
202 #ifdef CONFIG_HAS_DMA
203 dma_addr_t dma_maps
[MAX_SKB_FRAGS
+ 1];
207 /* We divide dataref into two halves. The higher 16 bits hold references
208 * to the payload part of skb->data. The lower 16 bits hold references to
209 * the entire skb->data. A clone of a headerless skb holds the length of
210 * the header in skb->hdr_len.
212 * All users must obey the rule that the skb->data reference count must be
213 * greater than or equal to the payload reference count.
215 * Holding a reference to the payload part means that the user does not
216 * care about modifications to the header part of skb->data.
218 #define SKB_DATAREF_SHIFT 16
219 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
223 SKB_FCLONE_UNAVAILABLE
,
229 SKB_GSO_TCPV4
= 1 << 0,
230 SKB_GSO_UDP
= 1 << 1,
232 /* This indicates the skb is from an untrusted source. */
233 SKB_GSO_DODGY
= 1 << 2,
235 /* This indicates the tcp segment has CWR set. */
236 SKB_GSO_TCP_ECN
= 1 << 3,
238 SKB_GSO_TCPV6
= 1 << 4,
241 #if BITS_PER_LONG > 32
242 #define NET_SKBUFF_DATA_USES_OFFSET 1
245 #ifdef NET_SKBUFF_DATA_USES_OFFSET
246 typedef unsigned int sk_buff_data_t
;
248 typedef unsigned char *sk_buff_data_t
;
252 * struct sk_buff - socket buffer
253 * @next: Next buffer in list
254 * @prev: Previous buffer in list
255 * @sk: Socket we are owned by
256 * @tstamp: Time we arrived
257 * @dev: Device we arrived on/are leaving by
258 * @transport_header: Transport layer header
259 * @network_header: Network layer header
260 * @mac_header: Link layer header
261 * @dst: destination entry
262 * @sp: the security path, used for xfrm
263 * @cb: Control buffer. Free for use by every layer. Put private vars here
264 * @len: Length of actual data
265 * @data_len: Data length
266 * @mac_len: Length of link layer header
267 * @hdr_len: writable header length of cloned skb
268 * @csum: Checksum (must include start/offset pair)
269 * @csum_start: Offset from skb->head where checksumming should start
270 * @csum_offset: Offset from csum_start where checksum should be stored
271 * @local_df: allow local fragmentation
272 * @cloned: Head may be cloned (check refcnt to be sure)
273 * @nohdr: Payload reference only, must not modify header
274 * @pkt_type: Packet class
275 * @fclone: skbuff clone status
276 * @ip_summed: Driver fed us an IP checksum
277 * @priority: Packet queueing priority
278 * @users: User count - see {datagram,tcp}.c
279 * @protocol: Packet protocol from driver
280 * @truesize: Buffer size
281 * @head: Head of buffer
282 * @data: Data head pointer
283 * @tail: Tail pointer
285 * @destructor: Destruct function
286 * @mark: Generic packet mark
287 * @nfct: Associated connection, if any
288 * @ipvs_property: skbuff is owned by ipvs
289 * @peeked: this packet has been seen already, so stats have been
290 * done for it, don't do them again
291 * @nf_trace: netfilter packet trace flag
292 * @nfctinfo: Relationship of this skb to the connection
293 * @nfct_reasm: netfilter conntrack re-assembly pointer
294 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
295 * @iif: ifindex of device we arrived on
296 * @queue_mapping: Queue mapping for multiqueue devices
297 * @tc_index: Traffic control index
298 * @tc_verd: traffic control verdict
299 * @ndisc_nodetype: router type (from link layer)
300 * @do_not_encrypt: set to prevent encryption of this frame
301 * @requeue: set to indicate that the wireless core should attempt
302 * a software retry on this frame if we failed to
303 * receive an ACK for it
304 * @dma_cookie: a cookie to one of several possible DMA operations
305 * done by skb DMA functions
306 * @secmark: security marking
307 * @vlan_tci: vlan tag control information
311 /* These two members must be first. */
312 struct sk_buff
*next
;
313 struct sk_buff
*prev
;
317 struct net_device
*dev
;
320 struct dst_entry
*dst
;
321 struct rtable
*rtable
;
327 * This is the control buffer. It is free to use for every
328 * layer. Please put your private variables there. If you
329 * want to keep them across layers you have to do a skb_clone()
330 * first. This is owned by whoever has the skb queued ATM.
358 void (*destructor
)(struct sk_buff
*skb
);
359 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
360 struct nf_conntrack
*nfct
;
361 struct sk_buff
*nfct_reasm
;
363 #ifdef CONFIG_BRIDGE_NETFILTER
364 struct nf_bridge_info
*nf_bridge
;
369 #ifdef CONFIG_NET_SCHED
370 __u16 tc_index
; /* traffic control index */
371 #ifdef CONFIG_NET_CLS_ACT
372 __u16 tc_verd
; /* traffic control verdict */
375 #ifdef CONFIG_IPV6_NDISC_NODETYPE
376 __u8 ndisc_nodetype
:2;
378 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
379 __u8 do_not_encrypt
:1;
382 /* 0/13/14 bit hole */
384 #ifdef CONFIG_NET_DMA
385 dma_cookie_t dma_cookie
;
387 #ifdef CONFIG_NETWORK_SECMARK
395 sk_buff_data_t transport_header
;
396 sk_buff_data_t network_header
;
397 sk_buff_data_t mac_header
;
398 /* These elements must be at the end, see alloc_skb() for details. */
403 unsigned int truesize
;
409 * Handling routines are only of interest to the kernel
411 #include <linux/slab.h>
413 #include <asm/system.h>
415 #ifdef CONFIG_HAS_DMA
416 #include <linux/dma-mapping.h>
417 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
418 enum dma_data_direction dir
);
419 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
420 enum dma_data_direction dir
);
423 extern void kfree_skb(struct sk_buff
*skb
);
424 extern void consume_skb(struct sk_buff
*skb
);
425 extern void __kfree_skb(struct sk_buff
*skb
);
426 extern struct sk_buff
*__alloc_skb(unsigned int size
,
427 gfp_t priority
, int fclone
, int node
);
428 static inline struct sk_buff
*alloc_skb(unsigned int size
,
431 return __alloc_skb(size
, priority
, 0, -1);
434 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
437 return __alloc_skb(size
, priority
, 1, -1);
440 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
442 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
443 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
445 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
447 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
449 extern int pskb_expand_head(struct sk_buff
*skb
,
450 int nhead
, int ntail
,
452 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
453 unsigned int headroom
);
454 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
455 int newheadroom
, int newtailroom
,
457 extern int skb_to_sgvec(struct sk_buff
*skb
,
458 struct scatterlist
*sg
, int offset
,
460 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
461 struct sk_buff
**trailer
);
462 extern int skb_pad(struct sk_buff
*skb
, int pad
);
463 #define dev_kfree_skb(a) consume_skb(a)
464 #define dev_consume_skb(a) kfree_skb_clean(a)
465 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
467 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
470 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
471 int getfrag(void *from
, char *to
, int offset
,
472 int len
,int odd
, struct sk_buff
*skb
),
473 void *from
, int length
);
480 __u32 stepped_offset
;
481 struct sk_buff
*root_skb
;
482 struct sk_buff
*cur_skb
;
486 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
487 unsigned int from
, unsigned int to
,
488 struct skb_seq_state
*st
);
489 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
490 struct skb_seq_state
*st
);
491 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
493 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
494 unsigned int to
, struct ts_config
*config
,
495 struct ts_state
*state
);
497 #ifdef NET_SKBUFF_DATA_USES_OFFSET
498 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
500 return skb
->head
+ skb
->end
;
503 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
510 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
512 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
514 return &skb_shinfo(skb
)->hwtstamps
;
517 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
519 return &skb_shinfo(skb
)->tx_flags
;
523 * skb_queue_empty - check if a queue is empty
526 * Returns true if the queue is empty, false otherwise.
528 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
530 return list
->next
== (struct sk_buff
*)list
;
534 * skb_queue_is_last - check if skb is the last entry in the queue
538 * Returns true if @skb is the last buffer on the list.
540 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
541 const struct sk_buff
*skb
)
543 return (skb
->next
== (struct sk_buff
*) list
);
547 * skb_queue_is_first - check if skb is the first entry in the queue
551 * Returns true if @skb is the first buffer on the list.
553 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
554 const struct sk_buff
*skb
)
556 return (skb
->prev
== (struct sk_buff
*) list
);
560 * skb_queue_next - return the next packet in the queue
562 * @skb: current buffer
564 * Return the next packet in @list after @skb. It is only valid to
565 * call this if skb_queue_is_last() evaluates to false.
567 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
568 const struct sk_buff
*skb
)
570 /* This BUG_ON may seem severe, but if we just return then we
571 * are going to dereference garbage.
573 BUG_ON(skb_queue_is_last(list
, skb
));
578 * skb_queue_prev - return the prev packet in the queue
580 * @skb: current buffer
582 * Return the prev packet in @list before @skb. It is only valid to
583 * call this if skb_queue_is_first() evaluates to false.
585 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
586 const struct sk_buff
*skb
)
588 /* This BUG_ON may seem severe, but if we just return then we
589 * are going to dereference garbage.
591 BUG_ON(skb_queue_is_first(list
, skb
));
596 * skb_get - reference buffer
597 * @skb: buffer to reference
599 * Makes another reference to a socket buffer and returns a pointer
602 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
604 atomic_inc(&skb
->users
);
609 * If users == 1, we are the only owner and are can avoid redundant
614 * skb_cloned - is the buffer a clone
615 * @skb: buffer to check
617 * Returns true if the buffer was generated with skb_clone() and is
618 * one of multiple shared copies of the buffer. Cloned buffers are
619 * shared data so must not be written to under normal circumstances.
621 static inline int skb_cloned(const struct sk_buff
*skb
)
623 return skb
->cloned
&&
624 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
628 * skb_header_cloned - is the header a clone
629 * @skb: buffer to check
631 * Returns true if modifying the header part of the buffer requires
632 * the data to be copied.
634 static inline int skb_header_cloned(const struct sk_buff
*skb
)
641 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
642 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
647 * skb_header_release - release reference to header
648 * @skb: buffer to operate on
650 * Drop a reference to the header part of the buffer. This is done
651 * by acquiring a payload reference. You must not read from the header
652 * part of skb->data after this.
654 static inline void skb_header_release(struct sk_buff
*skb
)
658 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
662 * skb_shared - is the buffer shared
663 * @skb: buffer to check
665 * Returns true if more than one person has a reference to this
668 static inline int skb_shared(const struct sk_buff
*skb
)
670 return atomic_read(&skb
->users
) != 1;
674 * skb_share_check - check if buffer is shared and if so clone it
675 * @skb: buffer to check
676 * @pri: priority for memory allocation
678 * If the buffer is shared the buffer is cloned and the old copy
679 * drops a reference. A new clone with a single reference is returned.
680 * If the buffer is not shared the original buffer is returned. When
681 * being called from interrupt status or with spinlocks held pri must
684 * NULL is returned on a memory allocation failure.
686 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
689 might_sleep_if(pri
& __GFP_WAIT
);
690 if (skb_shared(skb
)) {
691 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
699 * Copy shared buffers into a new sk_buff. We effectively do COW on
700 * packets to handle cases where we have a local reader and forward
701 * and a couple of other messy ones. The normal one is tcpdumping
702 * a packet thats being forwarded.
706 * skb_unshare - make a copy of a shared buffer
707 * @skb: buffer to check
708 * @pri: priority for memory allocation
710 * If the socket buffer is a clone then this function creates a new
711 * copy of the data, drops a reference count on the old copy and returns
712 * the new copy with the reference count at 1. If the buffer is not a clone
713 * the original buffer is returned. When called with a spinlock held or
714 * from interrupt state @pri must be %GFP_ATOMIC
716 * %NULL is returned on a memory allocation failure.
718 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
721 might_sleep_if(pri
& __GFP_WAIT
);
722 if (skb_cloned(skb
)) {
723 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
724 kfree_skb(skb
); /* Free our shared copy */
732 * @list_: list to peek at
734 * Peek an &sk_buff. Unlike most other operations you _MUST_
735 * be careful with this one. A peek leaves the buffer on the
736 * list and someone else may run off with it. You must hold
737 * the appropriate locks or have a private queue to do this.
739 * Returns %NULL for an empty list or a pointer to the head element.
740 * The reference count is not incremented and the reference is therefore
741 * volatile. Use with caution.
743 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
745 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
746 if (list
== (struct sk_buff
*)list_
)
753 * @list_: list to peek at
755 * Peek an &sk_buff. Unlike most other operations you _MUST_
756 * be careful with this one. A peek leaves the buffer on the
757 * list and someone else may run off with it. You must hold
758 * the appropriate locks or have a private queue to do this.
760 * Returns %NULL for an empty list or a pointer to the tail element.
761 * The reference count is not incremented and the reference is therefore
762 * volatile. Use with caution.
764 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
766 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
767 if (list
== (struct sk_buff
*)list_
)
773 * skb_queue_len - get queue length
774 * @list_: list to measure
776 * Return the length of an &sk_buff queue.
778 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
784 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
785 * @list: queue to initialize
787 * This initializes only the list and queue length aspects of
788 * an sk_buff_head object. This allows to initialize the list
789 * aspects of an sk_buff_head without reinitializing things like
790 * the spinlock. It can also be used for on-stack sk_buff_head
791 * objects where the spinlock is known to not be used.
793 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
795 list
->prev
= list
->next
= (struct sk_buff
*)list
;
800 * This function creates a split out lock class for each invocation;
801 * this is needed for now since a whole lot of users of the skb-queue
802 * infrastructure in drivers have different locking usage (in hardirq)
803 * than the networking core (in softirq only). In the long run either the
804 * network layer or drivers should need annotation to consolidate the
805 * main types of usage into 3 classes.
807 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
809 spin_lock_init(&list
->lock
);
810 __skb_queue_head_init(list
);
813 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
814 struct lock_class_key
*class)
816 skb_queue_head_init(list
);
817 lockdep_set_class(&list
->lock
, class);
821 * Insert an sk_buff on a list.
823 * The "__skb_xxxx()" functions are the non-atomic ones that
824 * can only be called with interrupts disabled.
826 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
827 static inline void __skb_insert(struct sk_buff
*newsk
,
828 struct sk_buff
*prev
, struct sk_buff
*next
,
829 struct sk_buff_head
*list
)
833 next
->prev
= prev
->next
= newsk
;
837 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
838 struct sk_buff
*prev
,
839 struct sk_buff
*next
)
841 struct sk_buff
*first
= list
->next
;
842 struct sk_buff
*last
= list
->prev
;
852 * skb_queue_splice - join two skb lists, this is designed for stacks
853 * @list: the new list to add
854 * @head: the place to add it in the first list
856 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
857 struct sk_buff_head
*head
)
859 if (!skb_queue_empty(list
)) {
860 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
861 head
->qlen
+= list
->qlen
;
866 * skb_queue_splice - join two skb lists and reinitialise the emptied list
867 * @list: the new list to add
868 * @head: the place to add it in the first list
870 * The list at @list is reinitialised
872 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
873 struct sk_buff_head
*head
)
875 if (!skb_queue_empty(list
)) {
876 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
877 head
->qlen
+= list
->qlen
;
878 __skb_queue_head_init(list
);
883 * skb_queue_splice_tail - join two skb lists, each list being a queue
884 * @list: the new list to add
885 * @head: the place to add it in the first list
887 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
888 struct sk_buff_head
*head
)
890 if (!skb_queue_empty(list
)) {
891 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
892 head
->qlen
+= list
->qlen
;
897 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
898 * @list: the new list to add
899 * @head: the place to add it in the first list
901 * Each of the lists is a queue.
902 * The list at @list is reinitialised
904 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
905 struct sk_buff_head
*head
)
907 if (!skb_queue_empty(list
)) {
908 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
909 head
->qlen
+= list
->qlen
;
910 __skb_queue_head_init(list
);
915 * __skb_queue_after - queue a buffer at the list head
917 * @prev: place after this buffer
918 * @newsk: buffer to queue
920 * Queue a buffer int the middle of a list. This function takes no locks
921 * and you must therefore hold required locks before calling it.
923 * A buffer cannot be placed on two lists at the same time.
925 static inline void __skb_queue_after(struct sk_buff_head
*list
,
926 struct sk_buff
*prev
,
927 struct sk_buff
*newsk
)
929 __skb_insert(newsk
, prev
, prev
->next
, list
);
932 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
933 struct sk_buff_head
*list
);
935 static inline void __skb_queue_before(struct sk_buff_head
*list
,
936 struct sk_buff
*next
,
937 struct sk_buff
*newsk
)
939 __skb_insert(newsk
, next
->prev
, next
, list
);
943 * __skb_queue_head - queue a buffer at the list head
945 * @newsk: buffer to queue
947 * Queue a buffer at the start of a list. This function takes no locks
948 * and you must therefore hold required locks before calling it.
950 * A buffer cannot be placed on two lists at the same time.
952 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
953 static inline void __skb_queue_head(struct sk_buff_head
*list
,
954 struct sk_buff
*newsk
)
956 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
960 * __skb_queue_tail - queue a buffer at the list tail
962 * @newsk: buffer to queue
964 * Queue a buffer at the end of a list. This function takes no locks
965 * and you must therefore hold required locks before calling it.
967 * A buffer cannot be placed on two lists at the same time.
969 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
970 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
971 struct sk_buff
*newsk
)
973 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
977 * remove sk_buff from list. _Must_ be called atomically, and with
980 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
981 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
983 struct sk_buff
*next
, *prev
;
988 skb
->next
= skb
->prev
= NULL
;
994 * __skb_dequeue - remove from the head of the queue
995 * @list: list to dequeue from
997 * Remove the head of the list. This function does not take any locks
998 * so must be used with appropriate locks held only. The head item is
999 * returned or %NULL if the list is empty.
1001 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1002 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1004 struct sk_buff
*skb
= skb_peek(list
);
1006 __skb_unlink(skb
, list
);
1011 * __skb_dequeue_tail - remove from the tail of the queue
1012 * @list: list to dequeue from
1014 * Remove the tail of the list. This function does not take any locks
1015 * so must be used with appropriate locks held only. The tail item is
1016 * returned or %NULL if the list is empty.
1018 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1019 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1021 struct sk_buff
*skb
= skb_peek_tail(list
);
1023 __skb_unlink(skb
, list
);
1028 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1030 return skb
->data_len
;
1033 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1035 return skb
->len
- skb
->data_len
;
1038 static inline int skb_pagelen(const struct sk_buff
*skb
)
1042 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1043 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1044 return len
+ skb_headlen(skb
);
1047 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1048 struct page
*page
, int off
, int size
)
1050 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1053 frag
->page_offset
= off
;
1055 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1058 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1061 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1062 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1063 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1065 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1066 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1068 return skb
->head
+ skb
->tail
;
1071 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1073 skb
->tail
= skb
->data
- skb
->head
;
1076 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1078 skb_reset_tail_pointer(skb
);
1079 skb
->tail
+= offset
;
1081 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1082 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1087 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1089 skb
->tail
= skb
->data
;
1092 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1094 skb
->tail
= skb
->data
+ offset
;
1097 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1100 * Add data to an sk_buff
1102 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1103 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1105 unsigned char *tmp
= skb_tail_pointer(skb
);
1106 SKB_LINEAR_ASSERT(skb
);
1112 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1113 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1120 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1121 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1124 BUG_ON(skb
->len
< skb
->data_len
);
1125 return skb
->data
+= len
;
1128 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1130 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1132 if (len
> skb_headlen(skb
) &&
1133 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1136 return skb
->data
+= len
;
1139 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1141 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1144 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1146 if (likely(len
<= skb_headlen(skb
)))
1148 if (unlikely(len
> skb
->len
))
1150 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1154 * skb_headroom - bytes at buffer head
1155 * @skb: buffer to check
1157 * Return the number of bytes of free space at the head of an &sk_buff.
1159 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1161 return skb
->data
- skb
->head
;
1165 * skb_tailroom - bytes at buffer end
1166 * @skb: buffer to check
1168 * Return the number of bytes of free space at the tail of an sk_buff
1170 static inline int skb_tailroom(const struct sk_buff
*skb
)
1172 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1176 * skb_reserve - adjust headroom
1177 * @skb: buffer to alter
1178 * @len: bytes to move
1180 * Increase the headroom of an empty &sk_buff by reducing the tail
1181 * room. This is only allowed for an empty buffer.
1183 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1189 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1190 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1192 return skb
->head
+ skb
->transport_header
;
1195 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1197 skb
->transport_header
= skb
->data
- skb
->head
;
1200 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1203 skb_reset_transport_header(skb
);
1204 skb
->transport_header
+= offset
;
1207 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1209 return skb
->head
+ skb
->network_header
;
1212 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1214 skb
->network_header
= skb
->data
- skb
->head
;
1217 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1219 skb_reset_network_header(skb
);
1220 skb
->network_header
+= offset
;
1223 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1225 return skb
->head
+ skb
->mac_header
;
1228 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1230 return skb
->mac_header
!= ~0U;
1233 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1235 skb
->mac_header
= skb
->data
- skb
->head
;
1238 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1240 skb_reset_mac_header(skb
);
1241 skb
->mac_header
+= offset
;
1244 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1246 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1248 return skb
->transport_header
;
1251 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1253 skb
->transport_header
= skb
->data
;
1256 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1259 skb
->transport_header
= skb
->data
+ offset
;
1262 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1264 return skb
->network_header
;
1267 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1269 skb
->network_header
= skb
->data
;
1272 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1274 skb
->network_header
= skb
->data
+ offset
;
1277 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1279 return skb
->mac_header
;
1282 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1284 return skb
->mac_header
!= NULL
;
1287 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1289 skb
->mac_header
= skb
->data
;
1292 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1294 skb
->mac_header
= skb
->data
+ offset
;
1296 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1298 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1300 return skb_transport_header(skb
) - skb
->data
;
1303 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1305 return skb
->transport_header
- skb
->network_header
;
1308 static inline int skb_network_offset(const struct sk_buff
*skb
)
1310 return skb_network_header(skb
) - skb
->data
;
1314 * CPUs often take a performance hit when accessing unaligned memory
1315 * locations. The actual performance hit varies, it can be small if the
1316 * hardware handles it or large if we have to take an exception and fix it
1319 * Since an ethernet header is 14 bytes network drivers often end up with
1320 * the IP header at an unaligned offset. The IP header can be aligned by
1321 * shifting the start of the packet by 2 bytes. Drivers should do this
1324 * skb_reserve(NET_IP_ALIGN);
1326 * The downside to this alignment of the IP header is that the DMA is now
1327 * unaligned. On some architectures the cost of an unaligned DMA is high
1328 * and this cost outweighs the gains made by aligning the IP header.
1330 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1333 #ifndef NET_IP_ALIGN
1334 #define NET_IP_ALIGN 2
1338 * The networking layer reserves some headroom in skb data (via
1339 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1340 * the header has to grow. In the default case, if the header has to grow
1341 * 32 bytes or less we avoid the reallocation.
1343 * Unfortunately this headroom changes the DMA alignment of the resulting
1344 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1345 * on some architectures. An architecture can override this value,
1346 * perhaps setting it to a cacheline in size (since that will maintain
1347 * cacheline alignment of the DMA). It must be a power of 2.
1349 * Various parts of the networking layer expect at least 32 bytes of
1350 * headroom, you should not reduce this.
1353 #define NET_SKB_PAD 32
1356 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1358 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1360 if (unlikely(skb
->data_len
)) {
1365 skb_set_tail_pointer(skb
, len
);
1368 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1370 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1373 return ___pskb_trim(skb
, len
);
1374 __skb_trim(skb
, len
);
1378 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1380 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1384 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1385 * @skb: buffer to alter
1388 * This is identical to pskb_trim except that the caller knows that
1389 * the skb is not cloned so we should never get an error due to out-
1392 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1394 int err
= pskb_trim(skb
, len
);
1399 * skb_orphan - orphan a buffer
1400 * @skb: buffer to orphan
1402 * If a buffer currently has an owner then we call the owner's
1403 * destructor function and make the @skb unowned. The buffer continues
1404 * to exist but is no longer charged to its former owner.
1406 static inline void skb_orphan(struct sk_buff
*skb
)
1408 if (skb
->destructor
)
1409 skb
->destructor(skb
);
1410 skb
->destructor
= NULL
;
1415 * __skb_queue_purge - empty a list
1416 * @list: list to empty
1418 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1419 * the list and one reference dropped. This function does not take the
1420 * list lock and the caller must hold the relevant locks to use it.
1422 extern void skb_queue_purge(struct sk_buff_head
*list
);
1423 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1425 struct sk_buff
*skb
;
1426 while ((skb
= __skb_dequeue(list
)) != NULL
)
1431 * __dev_alloc_skb - allocate an skbuff for receiving
1432 * @length: length to allocate
1433 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1435 * Allocate a new &sk_buff and assign it a usage count of one. The
1436 * buffer has unspecified headroom built in. Users should allocate
1437 * the headroom they think they need without accounting for the
1438 * built in space. The built in space is used for optimisations.
1440 * %NULL is returned if there is no free memory.
1442 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1445 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1447 skb_reserve(skb
, NET_SKB_PAD
);
1451 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1453 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1454 unsigned int length
, gfp_t gfp_mask
);
1457 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1458 * @dev: network device to receive on
1459 * @length: length to allocate
1461 * Allocate a new &sk_buff and assign it a usage count of one. The
1462 * buffer has unspecified headroom built in. Users should allocate
1463 * the headroom they think they need without accounting for the
1464 * built in space. The built in space is used for optimisations.
1466 * %NULL is returned if there is no free memory. Although this function
1467 * allocates memory it can be called from an interrupt.
1469 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1470 unsigned int length
)
1472 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1475 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1478 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1479 * @dev: network device to receive on
1481 * Allocate a new page node local to the specified device.
1483 * %NULL is returned if there is no free memory.
1485 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1487 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1490 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1496 * skb_clone_writable - is the header of a clone writable
1497 * @skb: buffer to check
1498 * @len: length up to which to write
1500 * Returns true if modifying the header part of the cloned buffer
1501 * does not requires the data to be copied.
1503 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1505 return !skb_header_cloned(skb
) &&
1506 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1509 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1514 if (headroom
< NET_SKB_PAD
)
1515 headroom
= NET_SKB_PAD
;
1516 if (headroom
> skb_headroom(skb
))
1517 delta
= headroom
- skb_headroom(skb
);
1519 if (delta
|| cloned
)
1520 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1526 * skb_cow - copy header of skb when it is required
1527 * @skb: buffer to cow
1528 * @headroom: needed headroom
1530 * If the skb passed lacks sufficient headroom or its data part
1531 * is shared, data is reallocated. If reallocation fails, an error
1532 * is returned and original skb is not changed.
1534 * The result is skb with writable area skb->head...skb->tail
1535 * and at least @headroom of space at head.
1537 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1539 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1543 * skb_cow_head - skb_cow but only making the head writable
1544 * @skb: buffer to cow
1545 * @headroom: needed headroom
1547 * This function is identical to skb_cow except that we replace the
1548 * skb_cloned check by skb_header_cloned. It should be used when
1549 * you only need to push on some header and do not need to modify
1552 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1554 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1558 * skb_padto - pad an skbuff up to a minimal size
1559 * @skb: buffer to pad
1560 * @len: minimal length
1562 * Pads up a buffer to ensure the trailing bytes exist and are
1563 * blanked. If the buffer already contains sufficient data it
1564 * is untouched. Otherwise it is extended. Returns zero on
1565 * success. The skb is freed on error.
1568 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1570 unsigned int size
= skb
->len
;
1571 if (likely(size
>= len
))
1573 return skb_pad(skb
, len
- size
);
1576 static inline int skb_add_data(struct sk_buff
*skb
,
1577 char __user
*from
, int copy
)
1579 const int off
= skb
->len
;
1581 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1583 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1586 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1589 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1592 __skb_trim(skb
, off
);
1596 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1597 struct page
*page
, int off
)
1600 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1602 return page
== frag
->page
&&
1603 off
== frag
->page_offset
+ frag
->size
;
1608 static inline int __skb_linearize(struct sk_buff
*skb
)
1610 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1614 * skb_linearize - convert paged skb to linear one
1615 * @skb: buffer to linarize
1617 * If there is no free memory -ENOMEM is returned, otherwise zero
1618 * is returned and the old skb data released.
1620 static inline int skb_linearize(struct sk_buff
*skb
)
1622 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1626 * skb_linearize_cow - make sure skb is linear and writable
1627 * @skb: buffer to process
1629 * If there is no free memory -ENOMEM is returned, otherwise zero
1630 * is returned and the old skb data released.
1632 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1634 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1635 __skb_linearize(skb
) : 0;
1639 * skb_postpull_rcsum - update checksum for received skb after pull
1640 * @skb: buffer to update
1641 * @start: start of data before pull
1642 * @len: length of data pulled
1644 * After doing a pull on a received packet, you need to call this to
1645 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1646 * CHECKSUM_NONE so that it can be recomputed from scratch.
1649 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1650 const void *start
, unsigned int len
)
1652 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1653 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1656 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1659 * pskb_trim_rcsum - trim received skb and update checksum
1660 * @skb: buffer to trim
1663 * This is exactly the same as pskb_trim except that it ensures the
1664 * checksum of received packets are still valid after the operation.
1667 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1669 if (likely(len
>= skb
->len
))
1671 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1672 skb
->ip_summed
= CHECKSUM_NONE
;
1673 return __pskb_trim(skb
, len
);
1676 #define skb_queue_walk(queue, skb) \
1677 for (skb = (queue)->next; \
1678 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1681 #define skb_queue_walk_safe(queue, skb, tmp) \
1682 for (skb = (queue)->next, tmp = skb->next; \
1683 skb != (struct sk_buff *)(queue); \
1684 skb = tmp, tmp = skb->next)
1686 #define skb_queue_walk_from(queue, skb) \
1687 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1690 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1691 for (tmp = skb->next; \
1692 skb != (struct sk_buff *)(queue); \
1693 skb = tmp, tmp = skb->next)
1695 #define skb_queue_reverse_walk(queue, skb) \
1696 for (skb = (queue)->prev; \
1697 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1701 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1702 int *peeked
, int *err
);
1703 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1704 int noblock
, int *err
);
1705 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1706 struct poll_table_struct
*wait
);
1707 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1708 int offset
, struct iovec
*to
,
1710 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1713 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1717 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1718 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1719 unsigned int flags
);
1720 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1721 int len
, __wsum csum
);
1722 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1724 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1725 const void *from
, int len
);
1726 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1727 int offset
, u8
*to
, int len
,
1729 extern int skb_splice_bits(struct sk_buff
*skb
,
1730 unsigned int offset
,
1731 struct pipe_inode_info
*pipe
,
1733 unsigned int flags
);
1734 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1735 extern void skb_split(struct sk_buff
*skb
,
1736 struct sk_buff
*skb1
, const u32 len
);
1737 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1740 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1742 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1743 int len
, void *buffer
)
1745 int hlen
= skb_headlen(skb
);
1747 if (hlen
- offset
>= len
)
1748 return skb
->data
+ offset
;
1750 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1756 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1758 const unsigned int len
)
1760 memcpy(to
, skb
->data
, len
);
1763 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1764 const int offset
, void *to
,
1765 const unsigned int len
)
1767 memcpy(to
, skb
->data
+ offset
, len
);
1770 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1772 const unsigned int len
)
1774 memcpy(skb
->data
, from
, len
);
1777 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1780 const unsigned int len
)
1782 memcpy(skb
->data
+ offset
, from
, len
);
1785 extern void skb_init(void);
1787 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1793 * skb_get_timestamp - get timestamp from a skb
1794 * @skb: skb to get stamp from
1795 * @stamp: pointer to struct timeval to store stamp in
1797 * Timestamps are stored in the skb as offsets to a base timestamp.
1798 * This function converts the offset back to a struct timeval and stores
1801 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1802 struct timeval
*stamp
)
1804 *stamp
= ktime_to_timeval(skb
->tstamp
);
1807 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1808 struct timespec
*stamp
)
1810 *stamp
= ktime_to_timespec(skb
->tstamp
);
1813 static inline void __net_timestamp(struct sk_buff
*skb
)
1815 skb
->tstamp
= ktime_get_real();
1818 static inline ktime_t
net_timedelta(ktime_t t
)
1820 return ktime_sub(ktime_get_real(), t
);
1823 static inline ktime_t
net_invalid_timestamp(void)
1825 return ktime_set(0, 0);
1829 * skb_tstamp_tx - queue clone of skb with send time stamps
1830 * @orig_skb: the original outgoing packet
1831 * @hwtstamps: hardware time stamps, may be NULL if not available
1833 * If the skb has a socket associated, then this function clones the
1834 * skb (thus sharing the actual data and optional structures), stores
1835 * the optional hardware time stamping information (if non NULL) or
1836 * generates a software time stamp (otherwise), then queues the clone
1837 * to the error queue of the socket. Errors are silently ignored.
1839 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1840 struct skb_shared_hwtstamps
*hwtstamps
);
1842 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1843 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1845 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1847 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1851 * skb_checksum_complete - Calculate checksum of an entire packet
1852 * @skb: packet to process
1854 * This function calculates the checksum over the entire packet plus
1855 * the value of skb->csum. The latter can be used to supply the
1856 * checksum of a pseudo header as used by TCP/UDP. It returns the
1859 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1860 * this function can be used to verify that checksum on received
1861 * packets. In that case the function should return zero if the
1862 * checksum is correct. In particular, this function will return zero
1863 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1864 * hardware has already verified the correctness of the checksum.
1866 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1868 return skb_csum_unnecessary(skb
) ?
1869 0 : __skb_checksum_complete(skb
);
1872 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1873 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1874 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1876 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1877 nf_conntrack_destroy(nfct
);
1879 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1882 atomic_inc(&nfct
->use
);
1884 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1887 atomic_inc(&skb
->users
);
1889 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1895 #ifdef CONFIG_BRIDGE_NETFILTER
1896 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1898 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1901 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1904 atomic_inc(&nf_bridge
->use
);
1906 #endif /* CONFIG_BRIDGE_NETFILTER */
1907 static inline void nf_reset(struct sk_buff
*skb
)
1909 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1910 nf_conntrack_put(skb
->nfct
);
1912 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1913 skb
->nfct_reasm
= NULL
;
1915 #ifdef CONFIG_BRIDGE_NETFILTER
1916 nf_bridge_put(skb
->nf_bridge
);
1917 skb
->nf_bridge
= NULL
;
1921 /* Note: This doesn't put any conntrack and bridge info in dst. */
1922 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1924 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1925 dst
->nfct
= src
->nfct
;
1926 nf_conntrack_get(src
->nfct
);
1927 dst
->nfctinfo
= src
->nfctinfo
;
1928 dst
->nfct_reasm
= src
->nfct_reasm
;
1929 nf_conntrack_get_reasm(src
->nfct_reasm
);
1931 #ifdef CONFIG_BRIDGE_NETFILTER
1932 dst
->nf_bridge
= src
->nf_bridge
;
1933 nf_bridge_get(src
->nf_bridge
);
1937 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1939 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1940 nf_conntrack_put(dst
->nfct
);
1941 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1943 #ifdef CONFIG_BRIDGE_NETFILTER
1944 nf_bridge_put(dst
->nf_bridge
);
1946 __nf_copy(dst
, src
);
1949 #ifdef CONFIG_NETWORK_SECMARK
1950 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1952 to
->secmark
= from
->secmark
;
1955 static inline void skb_init_secmark(struct sk_buff
*skb
)
1960 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1963 static inline void skb_init_secmark(struct sk_buff
*skb
)
1967 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1969 skb
->queue_mapping
= queue_mapping
;
1972 static inline u16
skb_get_queue_mapping(struct sk_buff
*skb
)
1974 return skb
->queue_mapping
;
1977 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1979 to
->queue_mapping
= from
->queue_mapping
;
1982 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
1984 skb
->queue_mapping
= rx_queue
+ 1;
1987 static inline u16
skb_get_rx_queue(struct sk_buff
*skb
)
1989 return skb
->queue_mapping
- 1;
1992 static inline bool skb_rx_queue_recorded(struct sk_buff
*skb
)
1994 return (skb
->queue_mapping
!= 0);
1998 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2003 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2009 static inline int skb_is_gso(const struct sk_buff
*skb
)
2011 return skb_shinfo(skb
)->gso_size
;
2014 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2016 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2019 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2021 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2023 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2024 * wanted then gso_type will be set. */
2025 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2026 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2027 __skb_warn_lro_forwarding(skb
);
2033 static inline void skb_forward_csum(struct sk_buff
*skb
)
2035 /* Unfortunately we don't support this one. Any brave souls? */
2036 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2037 skb
->ip_summed
= CHECKSUM_NONE
;
2040 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2041 #endif /* __KERNEL__ */
2042 #endif /* _LINUX_SKBUFF_H */