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
171 * @flags: all shared_tx flags
173 * These flags are attached to packets as part of the
174 * &skb_shared_info. Use skb_tx() to get a pointer.
176 union skb_shared_tx
{
185 /* This data is invariant across clones and lives at
186 * the end of the header data, ie. at skb->end.
188 struct skb_shared_info
{
190 unsigned short nr_frags
;
191 unsigned short gso_size
;
192 /* Warning: this field is not always filled in (UFO)! */
193 unsigned short gso_segs
;
194 unsigned short gso_type
;
196 union skb_shared_tx tx_flags
;
197 #ifdef CONFIG_HAS_DMA
198 unsigned int num_dma_maps
;
200 struct sk_buff
*frag_list
;
201 struct skb_shared_hwtstamps hwtstamps
;
202 skb_frag_t frags
[MAX_SKB_FRAGS
];
203 #ifdef CONFIG_HAS_DMA
204 dma_addr_t dma_maps
[MAX_SKB_FRAGS
+ 1];
206 /* Intermediate layers must ensure that destructor_arg
207 * remains valid until skb destructor */
208 void * destructor_arg
;
211 /* We divide dataref into two halves. The higher 16 bits hold references
212 * to the payload part of skb->data. The lower 16 bits hold references to
213 * the entire skb->data. A clone of a headerless skb holds the length of
214 * the header in skb->hdr_len.
216 * All users must obey the rule that the skb->data reference count must be
217 * greater than or equal to the payload reference count.
219 * Holding a reference to the payload part means that the user does not
220 * care about modifications to the header part of skb->data.
222 #define SKB_DATAREF_SHIFT 16
223 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
227 SKB_FCLONE_UNAVAILABLE
,
233 SKB_GSO_TCPV4
= 1 << 0,
234 SKB_GSO_UDP
= 1 << 1,
236 /* This indicates the skb is from an untrusted source. */
237 SKB_GSO_DODGY
= 1 << 2,
239 /* This indicates the tcp segment has CWR set. */
240 SKB_GSO_TCP_ECN
= 1 << 3,
242 SKB_GSO_TCPV6
= 1 << 4,
244 SKB_GSO_FCOE
= 1 << 5,
247 #if BITS_PER_LONG > 32
248 #define NET_SKBUFF_DATA_USES_OFFSET 1
251 #ifdef NET_SKBUFF_DATA_USES_OFFSET
252 typedef unsigned int sk_buff_data_t
;
254 typedef unsigned char *sk_buff_data_t
;
258 * struct sk_buff - socket buffer
259 * @next: Next buffer in list
260 * @prev: Previous buffer in list
261 * @sk: Socket we are owned by
262 * @tstamp: Time we arrived
263 * @dev: Device we arrived on/are leaving by
264 * @transport_header: Transport layer header
265 * @network_header: Network layer header
266 * @mac_header: Link layer header
267 * @dst: destination entry
268 * @sp: the security path, used for xfrm
269 * @cb: Control buffer. Free for use by every layer. Put private vars here
270 * @len: Length of actual data
271 * @data_len: Data length
272 * @mac_len: Length of link layer header
273 * @hdr_len: writable header length of cloned skb
274 * @csum: Checksum (must include start/offset pair)
275 * @csum_start: Offset from skb->head where checksumming should start
276 * @csum_offset: Offset from csum_start where checksum should be stored
277 * @local_df: allow local fragmentation
278 * @cloned: Head may be cloned (check refcnt to be sure)
279 * @nohdr: Payload reference only, must not modify header
280 * @pkt_type: Packet class
281 * @fclone: skbuff clone status
282 * @ip_summed: Driver fed us an IP checksum
283 * @priority: Packet queueing priority
284 * @users: User count - see {datagram,tcp}.c
285 * @protocol: Packet protocol from driver
286 * @truesize: Buffer size
287 * @head: Head of buffer
288 * @data: Data head pointer
289 * @tail: Tail pointer
291 * @destructor: Destruct function
292 * @mark: Generic packet mark
293 * @nfct: Associated connection, if any
294 * @ipvs_property: skbuff is owned by ipvs
295 * @peeked: this packet has been seen already, so stats have been
296 * done for it, don't do them again
297 * @nf_trace: netfilter packet trace flag
298 * @nfctinfo: Relationship of this skb to the connection
299 * @nfct_reasm: netfilter conntrack re-assembly pointer
300 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
301 * @iif: ifindex of device we arrived on
302 * @queue_mapping: Queue mapping for multiqueue devices
303 * @tc_index: Traffic control index
304 * @tc_verd: traffic control verdict
305 * @ndisc_nodetype: router type (from link layer)
306 * @do_not_encrypt: set to prevent encryption of this frame
307 * @requeue: set to indicate that the wireless core should attempt
308 * a software retry on this frame if we failed to
309 * receive an ACK for it
310 * @dma_cookie: a cookie to one of several possible DMA operations
311 * done by skb DMA functions
312 * @secmark: security marking
313 * @vlan_tci: vlan tag control information
317 /* These two members must be first. */
318 struct sk_buff
*next
;
319 struct sk_buff
*prev
;
323 struct net_device
*dev
;
326 struct dst_entry
*dst
;
327 unsigned long _skb_dst
;
333 * This is the control buffer. It is free to use for every
334 * layer. Please put your private variables there. If you
335 * want to keep them across layers you have to do a skb_clone()
336 * first. This is owned by whoever has the skb queued ATM.
364 void (*destructor
)(struct sk_buff
*skb
);
365 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
366 struct nf_conntrack
*nfct
;
367 struct sk_buff
*nfct_reasm
;
369 #ifdef CONFIG_BRIDGE_NETFILTER
370 struct nf_bridge_info
*nf_bridge
;
375 #ifdef CONFIG_NET_SCHED
376 __u16 tc_index
; /* traffic control index */
377 #ifdef CONFIG_NET_CLS_ACT
378 __u16 tc_verd
; /* traffic control verdict */
381 #ifdef CONFIG_IPV6_NDISC_NODETYPE
382 __u8 ndisc_nodetype
:2;
384 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
385 __u8 do_not_encrypt
:1;
388 /* 0/13/14 bit hole */
390 #ifdef CONFIG_NET_DMA
391 dma_cookie_t dma_cookie
;
393 #ifdef CONFIG_NETWORK_SECMARK
401 sk_buff_data_t transport_header
;
402 sk_buff_data_t network_header
;
403 sk_buff_data_t mac_header
;
404 /* These elements must be at the end, see alloc_skb() for details. */
409 unsigned int truesize
;
415 * Handling routines are only of interest to the kernel
417 #include <linux/slab.h>
419 #include <asm/system.h>
421 #ifdef CONFIG_HAS_DMA
422 #include <linux/dma-mapping.h>
423 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
424 enum dma_data_direction dir
);
425 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
426 enum dma_data_direction dir
);
429 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
431 return (struct rtable
*)skb
->_skb_dst
;
434 extern void kfree_skb(struct sk_buff
*skb
);
435 extern void consume_skb(struct sk_buff
*skb
);
436 extern void __kfree_skb(struct sk_buff
*skb
);
437 extern struct sk_buff
*__alloc_skb(unsigned int size
,
438 gfp_t priority
, int fclone
, int node
);
439 static inline struct sk_buff
*alloc_skb(unsigned int size
,
442 return __alloc_skb(size
, priority
, 0, -1);
445 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
448 return __alloc_skb(size
, priority
, 1, -1);
451 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
453 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
454 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
456 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
458 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
460 extern int pskb_expand_head(struct sk_buff
*skb
,
461 int nhead
, int ntail
,
463 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
464 unsigned int headroom
);
465 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
466 int newheadroom
, int newtailroom
,
468 extern int skb_to_sgvec(struct sk_buff
*skb
,
469 struct scatterlist
*sg
, int offset
,
471 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
472 struct sk_buff
**trailer
);
473 extern int skb_pad(struct sk_buff
*skb
, int pad
);
474 #define dev_kfree_skb(a) consume_skb(a)
475 #define dev_consume_skb(a) kfree_skb_clean(a)
476 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
478 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
481 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
482 int getfrag(void *from
, char *to
, int offset
,
483 int len
,int odd
, struct sk_buff
*skb
),
484 void *from
, int length
);
491 __u32 stepped_offset
;
492 struct sk_buff
*root_skb
;
493 struct sk_buff
*cur_skb
;
497 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
498 unsigned int from
, unsigned int to
,
499 struct skb_seq_state
*st
);
500 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
501 struct skb_seq_state
*st
);
502 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
504 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
505 unsigned int to
, struct ts_config
*config
,
506 struct ts_state
*state
);
508 #ifdef NET_SKBUFF_DATA_USES_OFFSET
509 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
511 return skb
->head
+ skb
->end
;
514 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
521 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
523 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
525 return &skb_shinfo(skb
)->hwtstamps
;
528 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
530 return &skb_shinfo(skb
)->tx_flags
;
534 * skb_queue_empty - check if a queue is empty
537 * Returns true if the queue is empty, false otherwise.
539 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
541 return list
->next
== (struct sk_buff
*)list
;
545 * skb_queue_is_last - check if skb is the last entry in the queue
549 * Returns true if @skb is the last buffer on the list.
551 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
552 const struct sk_buff
*skb
)
554 return (skb
->next
== (struct sk_buff
*) list
);
558 * skb_queue_is_first - check if skb is the first entry in the queue
562 * Returns true if @skb is the first buffer on the list.
564 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
565 const struct sk_buff
*skb
)
567 return (skb
->prev
== (struct sk_buff
*) list
);
571 * skb_queue_next - return the next packet in the queue
573 * @skb: current buffer
575 * Return the next packet in @list after @skb. It is only valid to
576 * call this if skb_queue_is_last() evaluates to false.
578 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
579 const struct sk_buff
*skb
)
581 /* This BUG_ON may seem severe, but if we just return then we
582 * are going to dereference garbage.
584 BUG_ON(skb_queue_is_last(list
, skb
));
589 * skb_queue_prev - return the prev packet in the queue
591 * @skb: current buffer
593 * Return the prev packet in @list before @skb. It is only valid to
594 * call this if skb_queue_is_first() evaluates to false.
596 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
597 const struct sk_buff
*skb
)
599 /* This BUG_ON may seem severe, but if we just return then we
600 * are going to dereference garbage.
602 BUG_ON(skb_queue_is_first(list
, skb
));
607 * skb_get - reference buffer
608 * @skb: buffer to reference
610 * Makes another reference to a socket buffer and returns a pointer
613 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
615 atomic_inc(&skb
->users
);
620 * If users == 1, we are the only owner and are can avoid redundant
625 * skb_cloned - is the buffer a clone
626 * @skb: buffer to check
628 * Returns true if the buffer was generated with skb_clone() and is
629 * one of multiple shared copies of the buffer. Cloned buffers are
630 * shared data so must not be written to under normal circumstances.
632 static inline int skb_cloned(const struct sk_buff
*skb
)
634 return skb
->cloned
&&
635 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
639 * skb_header_cloned - is the header a clone
640 * @skb: buffer to check
642 * Returns true if modifying the header part of the buffer requires
643 * the data to be copied.
645 static inline int skb_header_cloned(const struct sk_buff
*skb
)
652 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
653 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
658 * skb_header_release - release reference to header
659 * @skb: buffer to operate on
661 * Drop a reference to the header part of the buffer. This is done
662 * by acquiring a payload reference. You must not read from the header
663 * part of skb->data after this.
665 static inline void skb_header_release(struct sk_buff
*skb
)
669 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
673 * skb_shared - is the buffer shared
674 * @skb: buffer to check
676 * Returns true if more than one person has a reference to this
679 static inline int skb_shared(const struct sk_buff
*skb
)
681 return atomic_read(&skb
->users
) != 1;
685 * skb_share_check - check if buffer is shared and if so clone it
686 * @skb: buffer to check
687 * @pri: priority for memory allocation
689 * If the buffer is shared the buffer is cloned and the old copy
690 * drops a reference. A new clone with a single reference is returned.
691 * If the buffer is not shared the original buffer is returned. When
692 * being called from interrupt status or with spinlocks held pri must
695 * NULL is returned on a memory allocation failure.
697 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
700 might_sleep_if(pri
& __GFP_WAIT
);
701 if (skb_shared(skb
)) {
702 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
710 * Copy shared buffers into a new sk_buff. We effectively do COW on
711 * packets to handle cases where we have a local reader and forward
712 * and a couple of other messy ones. The normal one is tcpdumping
713 * a packet thats being forwarded.
717 * skb_unshare - make a copy of a shared buffer
718 * @skb: buffer to check
719 * @pri: priority for memory allocation
721 * If the socket buffer is a clone then this function creates a new
722 * copy of the data, drops a reference count on the old copy and returns
723 * the new copy with the reference count at 1. If the buffer is not a clone
724 * the original buffer is returned. When called with a spinlock held or
725 * from interrupt state @pri must be %GFP_ATOMIC
727 * %NULL is returned on a memory allocation failure.
729 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
732 might_sleep_if(pri
& __GFP_WAIT
);
733 if (skb_cloned(skb
)) {
734 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
735 kfree_skb(skb
); /* Free our shared copy */
743 * @list_: list to peek at
745 * Peek an &sk_buff. Unlike most other operations you _MUST_
746 * be careful with this one. A peek leaves the buffer on the
747 * list and someone else may run off with it. You must hold
748 * the appropriate locks or have a private queue to do this.
750 * Returns %NULL for an empty list or a pointer to the head element.
751 * The reference count is not incremented and the reference is therefore
752 * volatile. Use with caution.
754 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
756 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
757 if (list
== (struct sk_buff
*)list_
)
764 * @list_: list to peek at
766 * Peek an &sk_buff. Unlike most other operations you _MUST_
767 * be careful with this one. A peek leaves the buffer on the
768 * list and someone else may run off with it. You must hold
769 * the appropriate locks or have a private queue to do this.
771 * Returns %NULL for an empty list or a pointer to the tail element.
772 * The reference count is not incremented and the reference is therefore
773 * volatile. Use with caution.
775 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
777 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
778 if (list
== (struct sk_buff
*)list_
)
784 * skb_queue_len - get queue length
785 * @list_: list to measure
787 * Return the length of an &sk_buff queue.
789 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
795 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
796 * @list: queue to initialize
798 * This initializes only the list and queue length aspects of
799 * an sk_buff_head object. This allows to initialize the list
800 * aspects of an sk_buff_head without reinitializing things like
801 * the spinlock. It can also be used for on-stack sk_buff_head
802 * objects where the spinlock is known to not be used.
804 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
806 list
->prev
= list
->next
= (struct sk_buff
*)list
;
811 * This function creates a split out lock class for each invocation;
812 * this is needed for now since a whole lot of users of the skb-queue
813 * infrastructure in drivers have different locking usage (in hardirq)
814 * than the networking core (in softirq only). In the long run either the
815 * network layer or drivers should need annotation to consolidate the
816 * main types of usage into 3 classes.
818 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
820 spin_lock_init(&list
->lock
);
821 __skb_queue_head_init(list
);
824 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
825 struct lock_class_key
*class)
827 skb_queue_head_init(list
);
828 lockdep_set_class(&list
->lock
, class);
832 * Insert an sk_buff on a list.
834 * The "__skb_xxxx()" functions are the non-atomic ones that
835 * can only be called with interrupts disabled.
837 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
838 static inline void __skb_insert(struct sk_buff
*newsk
,
839 struct sk_buff
*prev
, struct sk_buff
*next
,
840 struct sk_buff_head
*list
)
844 next
->prev
= prev
->next
= newsk
;
848 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
849 struct sk_buff
*prev
,
850 struct sk_buff
*next
)
852 struct sk_buff
*first
= list
->next
;
853 struct sk_buff
*last
= list
->prev
;
863 * skb_queue_splice - join two skb lists, this is designed for stacks
864 * @list: the new list to add
865 * @head: the place to add it in the first list
867 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
868 struct sk_buff_head
*head
)
870 if (!skb_queue_empty(list
)) {
871 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
872 head
->qlen
+= list
->qlen
;
877 * skb_queue_splice - join two skb lists and reinitialise the emptied list
878 * @list: the new list to add
879 * @head: the place to add it in the first list
881 * The list at @list is reinitialised
883 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
884 struct sk_buff_head
*head
)
886 if (!skb_queue_empty(list
)) {
887 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
888 head
->qlen
+= list
->qlen
;
889 __skb_queue_head_init(list
);
894 * skb_queue_splice_tail - join two skb lists, each list being a queue
895 * @list: the new list to add
896 * @head: the place to add it in the first list
898 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
899 struct sk_buff_head
*head
)
901 if (!skb_queue_empty(list
)) {
902 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
903 head
->qlen
+= list
->qlen
;
908 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
909 * @list: the new list to add
910 * @head: the place to add it in the first list
912 * Each of the lists is a queue.
913 * The list at @list is reinitialised
915 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
916 struct sk_buff_head
*head
)
918 if (!skb_queue_empty(list
)) {
919 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
920 head
->qlen
+= list
->qlen
;
921 __skb_queue_head_init(list
);
926 * __skb_queue_after - queue a buffer at the list head
928 * @prev: place after this buffer
929 * @newsk: buffer to queue
931 * Queue a buffer int the middle of a list. This function takes no locks
932 * and you must therefore hold required locks before calling it.
934 * A buffer cannot be placed on two lists at the same time.
936 static inline void __skb_queue_after(struct sk_buff_head
*list
,
937 struct sk_buff
*prev
,
938 struct sk_buff
*newsk
)
940 __skb_insert(newsk
, prev
, prev
->next
, list
);
943 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
944 struct sk_buff_head
*list
);
946 static inline void __skb_queue_before(struct sk_buff_head
*list
,
947 struct sk_buff
*next
,
948 struct sk_buff
*newsk
)
950 __skb_insert(newsk
, next
->prev
, next
, list
);
954 * __skb_queue_head - queue a buffer at the list head
956 * @newsk: buffer to queue
958 * Queue a buffer at the start of a list. This function takes no locks
959 * and you must therefore hold required locks before calling it.
961 * A buffer cannot be placed on two lists at the same time.
963 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
964 static inline void __skb_queue_head(struct sk_buff_head
*list
,
965 struct sk_buff
*newsk
)
967 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
971 * __skb_queue_tail - queue a buffer at the list tail
973 * @newsk: buffer to queue
975 * Queue a buffer at the end of a list. This function takes no locks
976 * and you must therefore hold required locks before calling it.
978 * A buffer cannot be placed on two lists at the same time.
980 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
981 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
982 struct sk_buff
*newsk
)
984 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
988 * remove sk_buff from list. _Must_ be called atomically, and with
991 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
992 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
994 struct sk_buff
*next
, *prev
;
999 skb
->next
= skb
->prev
= NULL
;
1005 * __skb_dequeue - remove from the head of the queue
1006 * @list: list to dequeue from
1008 * Remove the head of the list. This function does not take any locks
1009 * so must be used with appropriate locks held only. The head item is
1010 * returned or %NULL if the list is empty.
1012 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1013 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1015 struct sk_buff
*skb
= skb_peek(list
);
1017 __skb_unlink(skb
, list
);
1022 * __skb_dequeue_tail - remove from the tail of the queue
1023 * @list: list to dequeue from
1025 * Remove the tail of the list. This function does not take any locks
1026 * so must be used with appropriate locks held only. The tail item is
1027 * returned or %NULL if the list is empty.
1029 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1030 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1032 struct sk_buff
*skb
= skb_peek_tail(list
);
1034 __skb_unlink(skb
, list
);
1039 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1041 return skb
->data_len
;
1044 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1046 return skb
->len
- skb
->data_len
;
1049 static inline int skb_pagelen(const struct sk_buff
*skb
)
1053 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1054 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1055 return len
+ skb_headlen(skb
);
1058 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1059 struct page
*page
, int off
, int size
)
1061 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1064 frag
->page_offset
= off
;
1066 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1069 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1072 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1073 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1074 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1076 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1077 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1079 return skb
->head
+ skb
->tail
;
1082 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1084 skb
->tail
= skb
->data
- skb
->head
;
1087 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1089 skb_reset_tail_pointer(skb
);
1090 skb
->tail
+= offset
;
1092 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1093 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1098 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1100 skb
->tail
= skb
->data
;
1103 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1105 skb
->tail
= skb
->data
+ offset
;
1108 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1111 * Add data to an sk_buff
1113 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1114 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1116 unsigned char *tmp
= skb_tail_pointer(skb
);
1117 SKB_LINEAR_ASSERT(skb
);
1123 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1124 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1131 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1132 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1135 BUG_ON(skb
->len
< skb
->data_len
);
1136 return skb
->data
+= len
;
1139 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1141 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1143 if (len
> skb_headlen(skb
) &&
1144 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1147 return skb
->data
+= len
;
1150 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1152 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1155 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1157 if (likely(len
<= skb_headlen(skb
)))
1159 if (unlikely(len
> skb
->len
))
1161 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1165 * skb_headroom - bytes at buffer head
1166 * @skb: buffer to check
1168 * Return the number of bytes of free space at the head of an &sk_buff.
1170 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1172 return skb
->data
- skb
->head
;
1176 * skb_tailroom - bytes at buffer end
1177 * @skb: buffer to check
1179 * Return the number of bytes of free space at the tail of an sk_buff
1181 static inline int skb_tailroom(const struct sk_buff
*skb
)
1183 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1187 * skb_reserve - adjust headroom
1188 * @skb: buffer to alter
1189 * @len: bytes to move
1191 * Increase the headroom of an empty &sk_buff by reducing the tail
1192 * room. This is only allowed for an empty buffer.
1194 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1200 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1201 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1203 return skb
->head
+ skb
->transport_header
;
1206 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1208 skb
->transport_header
= skb
->data
- skb
->head
;
1211 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1214 skb_reset_transport_header(skb
);
1215 skb
->transport_header
+= offset
;
1218 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1220 return skb
->head
+ skb
->network_header
;
1223 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1225 skb
->network_header
= skb
->data
- skb
->head
;
1228 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1230 skb_reset_network_header(skb
);
1231 skb
->network_header
+= offset
;
1234 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1236 return skb
->head
+ skb
->mac_header
;
1239 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1241 return skb
->mac_header
!= ~0U;
1244 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1246 skb
->mac_header
= skb
->data
- skb
->head
;
1249 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1251 skb_reset_mac_header(skb
);
1252 skb
->mac_header
+= offset
;
1255 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1257 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1259 return skb
->transport_header
;
1262 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1264 skb
->transport_header
= skb
->data
;
1267 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1270 skb
->transport_header
= skb
->data
+ offset
;
1273 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1275 return skb
->network_header
;
1278 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1280 skb
->network_header
= skb
->data
;
1283 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1285 skb
->network_header
= skb
->data
+ offset
;
1288 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1290 return skb
->mac_header
;
1293 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1295 return skb
->mac_header
!= NULL
;
1298 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1300 skb
->mac_header
= skb
->data
;
1303 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1305 skb
->mac_header
= skb
->data
+ offset
;
1307 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1309 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1311 return skb_transport_header(skb
) - skb
->data
;
1314 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1316 return skb
->transport_header
- skb
->network_header
;
1319 static inline int skb_network_offset(const struct sk_buff
*skb
)
1321 return skb_network_header(skb
) - skb
->data
;
1325 * CPUs often take a performance hit when accessing unaligned memory
1326 * locations. The actual performance hit varies, it can be small if the
1327 * hardware handles it or large if we have to take an exception and fix it
1330 * Since an ethernet header is 14 bytes network drivers often end up with
1331 * the IP header at an unaligned offset. The IP header can be aligned by
1332 * shifting the start of the packet by 2 bytes. Drivers should do this
1335 * skb_reserve(NET_IP_ALIGN);
1337 * The downside to this alignment of the IP header is that the DMA is now
1338 * unaligned. On some architectures the cost of an unaligned DMA is high
1339 * and this cost outweighs the gains made by aligning the IP header.
1341 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1344 #ifndef NET_IP_ALIGN
1345 #define NET_IP_ALIGN 2
1349 * The networking layer reserves some headroom in skb data (via
1350 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1351 * the header has to grow. In the default case, if the header has to grow
1352 * 32 bytes or less we avoid the reallocation.
1354 * Unfortunately this headroom changes the DMA alignment of the resulting
1355 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1356 * on some architectures. An architecture can override this value,
1357 * perhaps setting it to a cacheline in size (since that will maintain
1358 * cacheline alignment of the DMA). It must be a power of 2.
1360 * Various parts of the networking layer expect at least 32 bytes of
1361 * headroom, you should not reduce this.
1364 #define NET_SKB_PAD 32
1367 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1369 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1371 if (unlikely(skb
->data_len
)) {
1376 skb_set_tail_pointer(skb
, len
);
1379 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1381 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1384 return ___pskb_trim(skb
, len
);
1385 __skb_trim(skb
, len
);
1389 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1391 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1395 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1396 * @skb: buffer to alter
1399 * This is identical to pskb_trim except that the caller knows that
1400 * the skb is not cloned so we should never get an error due to out-
1403 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1405 int err
= pskb_trim(skb
, len
);
1410 * skb_orphan - orphan a buffer
1411 * @skb: buffer to orphan
1413 * If a buffer currently has an owner then we call the owner's
1414 * destructor function and make the @skb unowned. The buffer continues
1415 * to exist but is no longer charged to its former owner.
1417 static inline void skb_orphan(struct sk_buff
*skb
)
1419 if (skb
->destructor
)
1420 skb
->destructor(skb
);
1421 skb
->destructor
= NULL
;
1426 * __skb_queue_purge - empty a list
1427 * @list: list to empty
1429 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1430 * the list and one reference dropped. This function does not take the
1431 * list lock and the caller must hold the relevant locks to use it.
1433 extern void skb_queue_purge(struct sk_buff_head
*list
);
1434 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1436 struct sk_buff
*skb
;
1437 while ((skb
= __skb_dequeue(list
)) != NULL
)
1442 * __dev_alloc_skb - allocate an skbuff for receiving
1443 * @length: length to allocate
1444 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1446 * Allocate a new &sk_buff and assign it a usage count of one. The
1447 * buffer has unspecified headroom built in. Users should allocate
1448 * the headroom they think they need without accounting for the
1449 * built in space. The built in space is used for optimisations.
1451 * %NULL is returned if there is no free memory.
1453 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1456 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1458 skb_reserve(skb
, NET_SKB_PAD
);
1462 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1464 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1465 unsigned int length
, gfp_t gfp_mask
);
1468 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1469 * @dev: network device to receive on
1470 * @length: length to allocate
1472 * Allocate a new &sk_buff and assign it a usage count of one. The
1473 * buffer has unspecified headroom built in. Users should allocate
1474 * the headroom they think they need without accounting for the
1475 * built in space. The built in space is used for optimisations.
1477 * %NULL is returned if there is no free memory. Although this function
1478 * allocates memory it can be called from an interrupt.
1480 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1481 unsigned int length
)
1483 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1486 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1489 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1490 * @dev: network device to receive on
1492 * Allocate a new page node local to the specified device.
1494 * %NULL is returned if there is no free memory.
1496 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1498 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1501 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1507 * skb_clone_writable - is the header of a clone writable
1508 * @skb: buffer to check
1509 * @len: length up to which to write
1511 * Returns true if modifying the header part of the cloned buffer
1512 * does not requires the data to be copied.
1514 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1516 return !skb_header_cloned(skb
) &&
1517 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1520 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1525 if (headroom
< NET_SKB_PAD
)
1526 headroom
= NET_SKB_PAD
;
1527 if (headroom
> skb_headroom(skb
))
1528 delta
= headroom
- skb_headroom(skb
);
1530 if (delta
|| cloned
)
1531 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1537 * skb_cow - copy header of skb when it is required
1538 * @skb: buffer to cow
1539 * @headroom: needed headroom
1541 * If the skb passed lacks sufficient headroom or its data part
1542 * is shared, data is reallocated. If reallocation fails, an error
1543 * is returned and original skb is not changed.
1545 * The result is skb with writable area skb->head...skb->tail
1546 * and at least @headroom of space at head.
1548 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1550 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1554 * skb_cow_head - skb_cow but only making the head writable
1555 * @skb: buffer to cow
1556 * @headroom: needed headroom
1558 * This function is identical to skb_cow except that we replace the
1559 * skb_cloned check by skb_header_cloned. It should be used when
1560 * you only need to push on some header and do not need to modify
1563 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1565 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1569 * skb_padto - pad an skbuff up to a minimal size
1570 * @skb: buffer to pad
1571 * @len: minimal length
1573 * Pads up a buffer to ensure the trailing bytes exist and are
1574 * blanked. If the buffer already contains sufficient data it
1575 * is untouched. Otherwise it is extended. Returns zero on
1576 * success. The skb is freed on error.
1579 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1581 unsigned int size
= skb
->len
;
1582 if (likely(size
>= len
))
1584 return skb_pad(skb
, len
- size
);
1587 static inline int skb_add_data(struct sk_buff
*skb
,
1588 char __user
*from
, int copy
)
1590 const int off
= skb
->len
;
1592 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1594 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1597 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1600 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1603 __skb_trim(skb
, off
);
1607 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1608 struct page
*page
, int off
)
1611 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1613 return page
== frag
->page
&&
1614 off
== frag
->page_offset
+ frag
->size
;
1619 static inline int __skb_linearize(struct sk_buff
*skb
)
1621 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1625 * skb_linearize - convert paged skb to linear one
1626 * @skb: buffer to linarize
1628 * If there is no free memory -ENOMEM is returned, otherwise zero
1629 * is returned and the old skb data released.
1631 static inline int skb_linearize(struct sk_buff
*skb
)
1633 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1637 * skb_linearize_cow - make sure skb is linear and writable
1638 * @skb: buffer to process
1640 * If there is no free memory -ENOMEM is returned, otherwise zero
1641 * is returned and the old skb data released.
1643 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1645 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1646 __skb_linearize(skb
) : 0;
1650 * skb_postpull_rcsum - update checksum for received skb after pull
1651 * @skb: buffer to update
1652 * @start: start of data before pull
1653 * @len: length of data pulled
1655 * After doing a pull on a received packet, you need to call this to
1656 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1657 * CHECKSUM_NONE so that it can be recomputed from scratch.
1660 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1661 const void *start
, unsigned int len
)
1663 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1664 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1667 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1670 * pskb_trim_rcsum - trim received skb and update checksum
1671 * @skb: buffer to trim
1674 * This is exactly the same as pskb_trim except that it ensures the
1675 * checksum of received packets are still valid after the operation.
1678 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1680 if (likely(len
>= skb
->len
))
1682 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1683 skb
->ip_summed
= CHECKSUM_NONE
;
1684 return __pskb_trim(skb
, len
);
1687 #define skb_queue_walk(queue, skb) \
1688 for (skb = (queue)->next; \
1689 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1692 #define skb_queue_walk_safe(queue, skb, tmp) \
1693 for (skb = (queue)->next, tmp = skb->next; \
1694 skb != (struct sk_buff *)(queue); \
1695 skb = tmp, tmp = skb->next)
1697 #define skb_queue_walk_from(queue, skb) \
1698 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1701 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1702 for (tmp = skb->next; \
1703 skb != (struct sk_buff *)(queue); \
1704 skb = tmp, tmp = skb->next)
1706 #define skb_queue_reverse_walk(queue, skb) \
1707 for (skb = (queue)->prev; \
1708 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1712 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1713 int *peeked
, int *err
);
1714 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1715 int noblock
, int *err
);
1716 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1717 struct poll_table_struct
*wait
);
1718 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1719 int offset
, struct iovec
*to
,
1721 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1724 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1726 const struct iovec
*from
,
1729 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
1731 const struct iovec
*to
,
1734 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1735 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1736 unsigned int flags
);
1737 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1738 int len
, __wsum csum
);
1739 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1741 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1742 const void *from
, int len
);
1743 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1744 int offset
, u8
*to
, int len
,
1746 extern int skb_splice_bits(struct sk_buff
*skb
,
1747 unsigned int offset
,
1748 struct pipe_inode_info
*pipe
,
1750 unsigned int flags
);
1751 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1752 extern void skb_split(struct sk_buff
*skb
,
1753 struct sk_buff
*skb1
, const u32 len
);
1754 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1757 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1759 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1760 int len
, void *buffer
)
1762 int hlen
= skb_headlen(skb
);
1764 if (hlen
- offset
>= len
)
1765 return skb
->data
+ offset
;
1767 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1773 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1775 const unsigned int len
)
1777 memcpy(to
, skb
->data
, len
);
1780 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1781 const int offset
, void *to
,
1782 const unsigned int len
)
1784 memcpy(to
, skb
->data
+ offset
, len
);
1787 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1789 const unsigned int len
)
1791 memcpy(skb
->data
, from
, len
);
1794 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1797 const unsigned int len
)
1799 memcpy(skb
->data
+ offset
, from
, len
);
1802 extern void skb_init(void);
1804 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1810 * skb_get_timestamp - get timestamp from a skb
1811 * @skb: skb to get stamp from
1812 * @stamp: pointer to struct timeval to store stamp in
1814 * Timestamps are stored in the skb as offsets to a base timestamp.
1815 * This function converts the offset back to a struct timeval and stores
1818 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1819 struct timeval
*stamp
)
1821 *stamp
= ktime_to_timeval(skb
->tstamp
);
1824 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1825 struct timespec
*stamp
)
1827 *stamp
= ktime_to_timespec(skb
->tstamp
);
1830 static inline void __net_timestamp(struct sk_buff
*skb
)
1832 skb
->tstamp
= ktime_get_real();
1835 static inline ktime_t
net_timedelta(ktime_t t
)
1837 return ktime_sub(ktime_get_real(), t
);
1840 static inline ktime_t
net_invalid_timestamp(void)
1842 return ktime_set(0, 0);
1846 * skb_tstamp_tx - queue clone of skb with send time stamps
1847 * @orig_skb: the original outgoing packet
1848 * @hwtstamps: hardware time stamps, may be NULL if not available
1850 * If the skb has a socket associated, then this function clones the
1851 * skb (thus sharing the actual data and optional structures), stores
1852 * the optional hardware time stamping information (if non NULL) or
1853 * generates a software time stamp (otherwise), then queues the clone
1854 * to the error queue of the socket. Errors are silently ignored.
1856 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1857 struct skb_shared_hwtstamps
*hwtstamps
);
1859 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1860 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1862 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1864 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1868 * skb_checksum_complete - Calculate checksum of an entire packet
1869 * @skb: packet to process
1871 * This function calculates the checksum over the entire packet plus
1872 * the value of skb->csum. The latter can be used to supply the
1873 * checksum of a pseudo header as used by TCP/UDP. It returns the
1876 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1877 * this function can be used to verify that checksum on received
1878 * packets. In that case the function should return zero if the
1879 * checksum is correct. In particular, this function will return zero
1880 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1881 * hardware has already verified the correctness of the checksum.
1883 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1885 return skb_csum_unnecessary(skb
) ?
1886 0 : __skb_checksum_complete(skb
);
1889 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1890 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1891 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1893 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1894 nf_conntrack_destroy(nfct
);
1896 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1899 atomic_inc(&nfct
->use
);
1901 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1904 atomic_inc(&skb
->users
);
1906 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1912 #ifdef CONFIG_BRIDGE_NETFILTER
1913 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1915 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1918 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1921 atomic_inc(&nf_bridge
->use
);
1923 #endif /* CONFIG_BRIDGE_NETFILTER */
1924 static inline void nf_reset(struct sk_buff
*skb
)
1926 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1927 nf_conntrack_put(skb
->nfct
);
1929 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1930 skb
->nfct_reasm
= NULL
;
1932 #ifdef CONFIG_BRIDGE_NETFILTER
1933 nf_bridge_put(skb
->nf_bridge
);
1934 skb
->nf_bridge
= NULL
;
1938 /* Note: This doesn't put any conntrack and bridge info in dst. */
1939 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1941 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1942 dst
->nfct
= src
->nfct
;
1943 nf_conntrack_get(src
->nfct
);
1944 dst
->nfctinfo
= src
->nfctinfo
;
1945 dst
->nfct_reasm
= src
->nfct_reasm
;
1946 nf_conntrack_get_reasm(src
->nfct_reasm
);
1948 #ifdef CONFIG_BRIDGE_NETFILTER
1949 dst
->nf_bridge
= src
->nf_bridge
;
1950 nf_bridge_get(src
->nf_bridge
);
1954 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1956 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1957 nf_conntrack_put(dst
->nfct
);
1958 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1960 #ifdef CONFIG_BRIDGE_NETFILTER
1961 nf_bridge_put(dst
->nf_bridge
);
1963 __nf_copy(dst
, src
);
1966 #ifdef CONFIG_NETWORK_SECMARK
1967 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1969 to
->secmark
= from
->secmark
;
1972 static inline void skb_init_secmark(struct sk_buff
*skb
)
1977 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1980 static inline void skb_init_secmark(struct sk_buff
*skb
)
1984 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1986 skb
->queue_mapping
= queue_mapping
;
1989 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
1991 return skb
->queue_mapping
;
1994 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1996 to
->queue_mapping
= from
->queue_mapping
;
1999 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2001 skb
->queue_mapping
= rx_queue
+ 1;
2004 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2006 return skb
->queue_mapping
- 1;
2009 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2011 return (skb
->queue_mapping
!= 0);
2014 extern u16
skb_tx_hash(const struct net_device
*dev
,
2015 const struct sk_buff
*skb
);
2018 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2023 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2029 static inline int skb_is_gso(const struct sk_buff
*skb
)
2031 return skb_shinfo(skb
)->gso_size
;
2034 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2036 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2039 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2041 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2043 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2044 * wanted then gso_type will be set. */
2045 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2046 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2047 __skb_warn_lro_forwarding(skb
);
2053 static inline void skb_forward_csum(struct sk_buff
*skb
)
2055 /* Unfortunately we don't support this one. Any brave souls? */
2056 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2057 skb
->ip_summed
= CHECKSUM_NONE
;
2060 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2061 #endif /* __KERNEL__ */
2062 #endif /* _LINUX_SKBUFF_H */