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/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/cache.h>
23 #include <asm/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/dmaengine.h>
31 #include <linux/hrtimer.h>
33 /* Don't change this without changing skb_csum_unnecessary! */
34 #define CHECKSUM_NONE 0
35 #define CHECKSUM_UNNECESSARY 1
36 #define CHECKSUM_COMPLETE 2
37 #define CHECKSUM_PARTIAL 3
39 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
40 ~(SMP_CACHE_BYTES - 1))
41 #define SKB_WITH_OVERHEAD(X) \
42 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
43 #define SKB_MAX_ORDER(X, ORDER) \
44 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
45 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
46 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
48 /* A. Checksumming of received packets by device.
50 * NONE: device failed to checksum this packet.
51 * skb->csum is undefined.
53 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
54 * skb->csum is undefined.
55 * It is bad option, but, unfortunately, many of vendors do this.
56 * Apparently with secret goal to sell you new device, when you
57 * will add new protocol to your host. F.e. IPv6. 8)
59 * COMPLETE: the most generic way. Device supplied checksum of _all_
60 * the packet as seen by netif_rx in skb->csum.
61 * NOTE: Even if device supports only some protocols, but
62 * is able to produce some skb->csum, it MUST use COMPLETE,
65 * PARTIAL: identical to the case for output below. This may occur
66 * on a packet received directly from another Linux OS, e.g.,
67 * a virtualised Linux kernel on the same host. The packet can
68 * be treated in the same way as UNNECESSARY except that on
69 * output (i.e., forwarding) the checksum must be filled in
70 * by the OS or the hardware.
72 * B. Checksumming on output.
74 * NONE: skb is checksummed by protocol or csum is not required.
76 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
77 * from skb->csum_start to the end and to record the checksum
78 * at skb->csum_start + skb->csum_offset.
80 * Device must show its capabilities in dev->features, set
81 * at device setup time.
82 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
84 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
85 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
86 * TCP/UDP over IPv4. Sigh. Vendors like this
87 * way by an unknown reason. Though, see comment above
88 * about CHECKSUM_UNNECESSARY. 8)
89 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
91 * Any questions? No questions, good. --ANK
96 struct pipe_inode_info
;
98 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
104 #ifdef CONFIG_BRIDGE_NETFILTER
105 struct nf_bridge_info
{
107 struct net_device
*physindev
;
108 struct net_device
*physoutdev
;
110 unsigned long data
[32 / sizeof(unsigned long)];
114 struct sk_buff_head
{
115 /* These two members must be first. */
116 struct sk_buff
*next
;
117 struct sk_buff
*prev
;
125 /* To allow 64K frame to be packed as single skb without frag_list */
126 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
128 typedef struct skb_frag_struct skb_frag_t
;
130 struct skb_frag_struct
{
136 #define HAVE_HW_TIME_STAMP
139 * struct skb_shared_hwtstamps - hardware time stamps
140 * @hwtstamp: hardware time stamp transformed into duration
141 * since arbitrary point in time
142 * @syststamp: hwtstamp transformed to system time base
144 * Software time stamps generated by ktime_get_real() are stored in
145 * skb->tstamp. The relation between the different kinds of time
146 * stamps is as follows:
148 * syststamp and tstamp can be compared against each other in
149 * arbitrary combinations. The accuracy of a
150 * syststamp/tstamp/"syststamp from other device" comparison is
151 * limited by the accuracy of the transformation into system time
152 * base. This depends on the device driver and its underlying
155 * hwtstamps can only be compared against other hwtstamps from
158 * This structure is attached to packets as part of the
159 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
161 struct skb_shared_hwtstamps
{
167 * struct skb_shared_tx - instructions for time stamping of outgoing packets
168 * @hardware: generate hardware time stamp
169 * @software: generate software time stamp
170 * @in_progress: device driver is going to provide
171 * hardware time stamp
172 * @flags: all shared_tx flags
174 * These flags are attached to packets as part of the
175 * &skb_shared_info. Use skb_tx() to get a pointer.
177 union skb_shared_tx
{
186 /* This data is invariant across clones and lives at
187 * the end of the header data, ie. at skb->end.
189 struct skb_shared_info
{
191 unsigned short nr_frags
;
192 unsigned short gso_size
;
193 #ifdef CONFIG_HAS_DMA
196 /* Warning: this field is not always filled in (UFO)! */
197 unsigned short gso_segs
;
198 unsigned short gso_type
;
200 union skb_shared_tx tx_flags
;
201 struct sk_buff
*frag_list
;
202 struct skb_shared_hwtstamps hwtstamps
;
203 skb_frag_t frags
[MAX_SKB_FRAGS
];
204 #ifdef CONFIG_HAS_DMA
205 dma_addr_t dma_maps
[MAX_SKB_FRAGS
];
207 /* Intermediate layers must ensure that destructor_arg
208 * remains valid until skb destructor */
209 void * destructor_arg
;
212 /* We divide dataref into two halves. The higher 16 bits hold references
213 * to the payload part of skb->data. The lower 16 bits hold references to
214 * the entire skb->data. A clone of a headerless skb holds the length of
215 * the header in skb->hdr_len.
217 * All users must obey the rule that the skb->data reference count must be
218 * greater than or equal to the payload reference count.
220 * Holding a reference to the payload part means that the user does not
221 * care about modifications to the header part of skb->data.
223 #define SKB_DATAREF_SHIFT 16
224 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
228 SKB_FCLONE_UNAVAILABLE
,
234 SKB_GSO_TCPV4
= 1 << 0,
235 SKB_GSO_UDP
= 1 << 1,
237 /* This indicates the skb is from an untrusted source. */
238 SKB_GSO_DODGY
= 1 << 2,
240 /* This indicates the tcp segment has CWR set. */
241 SKB_GSO_TCP_ECN
= 1 << 3,
243 SKB_GSO_TCPV6
= 1 << 4,
245 SKB_GSO_FCOE
= 1 << 5,
248 #if BITS_PER_LONG > 32
249 #define NET_SKBUFF_DATA_USES_OFFSET 1
252 #ifdef NET_SKBUFF_DATA_USES_OFFSET
253 typedef unsigned int sk_buff_data_t
;
255 typedef unsigned char *sk_buff_data_t
;
259 * struct sk_buff - socket buffer
260 * @next: Next buffer in list
261 * @prev: Previous buffer in list
262 * @sk: Socket we are owned by
263 * @tstamp: Time we arrived
264 * @dev: Device we arrived on/are leaving by
265 * @transport_header: Transport layer header
266 * @network_header: Network layer header
267 * @mac_header: Link layer header
268 * @_skb_dst: destination entry
269 * @sp: the security path, used for xfrm
270 * @cb: Control buffer. Free for use by every layer. Put private vars here
271 * @len: Length of actual data
272 * @data_len: Data length
273 * @mac_len: Length of link layer header
274 * @hdr_len: writable header length of cloned skb
275 * @csum: Checksum (must include start/offset pair)
276 * @csum_start: Offset from skb->head where checksumming should start
277 * @csum_offset: Offset from csum_start where checksum should be stored
278 * @local_df: allow local fragmentation
279 * @cloned: Head may be cloned (check refcnt to be sure)
280 * @nohdr: Payload reference only, must not modify header
281 * @pkt_type: Packet class
282 * @fclone: skbuff clone status
283 * @ip_summed: Driver fed us an IP checksum
284 * @priority: Packet queueing priority
285 * @users: User count - see {datagram,tcp}.c
286 * @protocol: Packet protocol from driver
287 * @truesize: Buffer size
288 * @head: Head of buffer
289 * @data: Data head pointer
290 * @tail: Tail pointer
292 * @destructor: Destruct function
293 * @mark: Generic packet mark
294 * @nfct: Associated connection, if any
295 * @ipvs_property: skbuff is owned by ipvs
296 * @peeked: this packet has been seen already, so stats have been
297 * done for it, don't do them again
298 * @nf_trace: netfilter packet trace flag
299 * @nfctinfo: Relationship of this skb to the connection
300 * @nfct_reasm: netfilter conntrack re-assembly pointer
301 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
302 * @iif: ifindex of device we arrived on
303 * @queue_mapping: Queue mapping for multiqueue devices
304 * @tc_index: Traffic control index
305 * @tc_verd: traffic control verdict
306 * @ndisc_nodetype: router type (from link layer)
307 * @dma_cookie: a cookie to one of several possible DMA operations
308 * done by skb DMA functions
309 * @secmark: security marking
310 * @vlan_tci: vlan tag control information
314 /* These two members must be first. */
315 struct sk_buff
*next
;
316 struct sk_buff
*prev
;
320 struct net_device
*dev
;
322 unsigned long _skb_dst
;
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.
346 kmemcheck_bitfield_begin(flags1
);
358 kmemcheck_bitfield_end(flags1
);
360 void (*destructor
)(struct sk_buff
*skb
);
361 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
362 struct nf_conntrack
*nfct
;
363 struct sk_buff
*nfct_reasm
;
365 #ifdef CONFIG_BRIDGE_NETFILTER
366 struct nf_bridge_info
*nf_bridge
;
370 #ifdef CONFIG_NET_SCHED
371 __u16 tc_index
; /* traffic control index */
372 #ifdef CONFIG_NET_CLS_ACT
373 __u16 tc_verd
; /* traffic control verdict */
377 kmemcheck_bitfield_begin(flags2
);
378 __u16 queue_mapping
:16;
379 #ifdef CONFIG_IPV6_NDISC_NODETYPE
380 __u8 ndisc_nodetype
:2;
382 kmemcheck_bitfield_end(flags2
);
386 #ifdef CONFIG_NET_DMA
387 dma_cookie_t dma_cookie
;
389 #ifdef CONFIG_NETWORK_SECMARK
399 sk_buff_data_t transport_header
;
400 sk_buff_data_t network_header
;
401 sk_buff_data_t mac_header
;
402 /* These elements must be at the end, see alloc_skb() for details. */
407 unsigned int truesize
;
413 * Handling routines are only of interest to the kernel
415 #include <linux/slab.h>
417 #include <asm/system.h>
419 #ifdef CONFIG_HAS_DMA
420 #include <linux/dma-mapping.h>
421 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
422 enum dma_data_direction dir
);
423 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
424 enum dma_data_direction dir
);
427 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
429 return (struct dst_entry
*)skb
->_skb_dst
;
432 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
434 skb
->_skb_dst
= (unsigned long)dst
;
437 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
439 return (struct rtable
*)skb_dst(skb
);
442 extern void kfree_skb(struct sk_buff
*skb
);
443 extern void consume_skb(struct sk_buff
*skb
);
444 extern void __kfree_skb(struct sk_buff
*skb
);
445 extern struct sk_buff
*__alloc_skb(unsigned int size
,
446 gfp_t priority
, int fclone
, int node
);
447 static inline struct sk_buff
*alloc_skb(unsigned int size
,
450 return __alloc_skb(size
, priority
, 0, -1);
453 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
456 return __alloc_skb(size
, priority
, 1, -1);
459 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
461 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
462 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
464 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
466 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
468 extern int pskb_expand_head(struct sk_buff
*skb
,
469 int nhead
, int ntail
,
471 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
472 unsigned int headroom
);
473 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
474 int newheadroom
, int newtailroom
,
476 extern int skb_to_sgvec(struct sk_buff
*skb
,
477 struct scatterlist
*sg
, int offset
,
479 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
480 struct sk_buff
**trailer
);
481 extern int skb_pad(struct sk_buff
*skb
, int pad
);
482 #define dev_kfree_skb(a) consume_skb(a)
483 #define dev_consume_skb(a) kfree_skb_clean(a)
484 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
486 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
489 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
490 int getfrag(void *from
, char *to
, int offset
,
491 int len
,int odd
, struct sk_buff
*skb
),
492 void *from
, int length
);
494 struct skb_seq_state
{
498 __u32 stepped_offset
;
499 struct sk_buff
*root_skb
;
500 struct sk_buff
*cur_skb
;
504 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
505 unsigned int from
, unsigned int to
,
506 struct skb_seq_state
*st
);
507 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
508 struct skb_seq_state
*st
);
509 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
511 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
512 unsigned int to
, struct ts_config
*config
,
513 struct ts_state
*state
);
515 #ifdef NET_SKBUFF_DATA_USES_OFFSET
516 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
518 return skb
->head
+ skb
->end
;
521 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
528 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
530 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
532 return &skb_shinfo(skb
)->hwtstamps
;
535 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
537 return &skb_shinfo(skb
)->tx_flags
;
541 * skb_queue_empty - check if a queue is empty
544 * Returns true if the queue is empty, false otherwise.
546 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
548 return list
->next
== (struct sk_buff
*)list
;
552 * skb_queue_is_last - check if skb is the last entry in the queue
556 * Returns true if @skb is the last buffer on the list.
558 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
559 const struct sk_buff
*skb
)
561 return (skb
->next
== (struct sk_buff
*) list
);
565 * skb_queue_is_first - check if skb is the first entry in the queue
569 * Returns true if @skb is the first buffer on the list.
571 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
572 const struct sk_buff
*skb
)
574 return (skb
->prev
== (struct sk_buff
*) list
);
578 * skb_queue_next - return the next packet in the queue
580 * @skb: current buffer
582 * Return the next packet in @list after @skb. It is only valid to
583 * call this if skb_queue_is_last() evaluates to false.
585 static inline struct sk_buff
*skb_queue_next(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_last(list
, skb
));
596 * skb_queue_prev - return the prev packet in the queue
598 * @skb: current buffer
600 * Return the prev packet in @list before @skb. It is only valid to
601 * call this if skb_queue_is_first() evaluates to false.
603 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
604 const struct sk_buff
*skb
)
606 /* This BUG_ON may seem severe, but if we just return then we
607 * are going to dereference garbage.
609 BUG_ON(skb_queue_is_first(list
, skb
));
614 * skb_get - reference buffer
615 * @skb: buffer to reference
617 * Makes another reference to a socket buffer and returns a pointer
620 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
622 atomic_inc(&skb
->users
);
627 * If users == 1, we are the only owner and are can avoid redundant
632 * skb_cloned - is the buffer a clone
633 * @skb: buffer to check
635 * Returns true if the buffer was generated with skb_clone() and is
636 * one of multiple shared copies of the buffer. Cloned buffers are
637 * shared data so must not be written to under normal circumstances.
639 static inline int skb_cloned(const struct sk_buff
*skb
)
641 return skb
->cloned
&&
642 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
646 * skb_header_cloned - is the header a clone
647 * @skb: buffer to check
649 * Returns true if modifying the header part of the buffer requires
650 * the data to be copied.
652 static inline int skb_header_cloned(const struct sk_buff
*skb
)
659 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
660 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
665 * skb_header_release - release reference to header
666 * @skb: buffer to operate on
668 * Drop a reference to the header part of the buffer. This is done
669 * by acquiring a payload reference. You must not read from the header
670 * part of skb->data after this.
672 static inline void skb_header_release(struct sk_buff
*skb
)
676 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
680 * skb_shared - is the buffer shared
681 * @skb: buffer to check
683 * Returns true if more than one person has a reference to this
686 static inline int skb_shared(const struct sk_buff
*skb
)
688 return atomic_read(&skb
->users
) != 1;
692 * skb_share_check - check if buffer is shared and if so clone it
693 * @skb: buffer to check
694 * @pri: priority for memory allocation
696 * If the buffer is shared the buffer is cloned and the old copy
697 * drops a reference. A new clone with a single reference is returned.
698 * If the buffer is not shared the original buffer is returned. When
699 * being called from interrupt status or with spinlocks held pri must
702 * NULL is returned on a memory allocation failure.
704 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
707 might_sleep_if(pri
& __GFP_WAIT
);
708 if (skb_shared(skb
)) {
709 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
717 * Copy shared buffers into a new sk_buff. We effectively do COW on
718 * packets to handle cases where we have a local reader and forward
719 * and a couple of other messy ones. The normal one is tcpdumping
720 * a packet thats being forwarded.
724 * skb_unshare - make a copy of a shared buffer
725 * @skb: buffer to check
726 * @pri: priority for memory allocation
728 * If the socket buffer is a clone then this function creates a new
729 * copy of the data, drops a reference count on the old copy and returns
730 * the new copy with the reference count at 1. If the buffer is not a clone
731 * the original buffer is returned. When called with a spinlock held or
732 * from interrupt state @pri must be %GFP_ATOMIC
734 * %NULL is returned on a memory allocation failure.
736 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
739 might_sleep_if(pri
& __GFP_WAIT
);
740 if (skb_cloned(skb
)) {
741 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
742 kfree_skb(skb
); /* Free our shared copy */
750 * @list_: list to peek at
752 * Peek an &sk_buff. Unlike most other operations you _MUST_
753 * be careful with this one. A peek leaves the buffer on the
754 * list and someone else may run off with it. You must hold
755 * the appropriate locks or have a private queue to do this.
757 * Returns %NULL for an empty list or a pointer to the head element.
758 * The reference count is not incremented and the reference is therefore
759 * volatile. Use with caution.
761 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
763 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
764 if (list
== (struct sk_buff
*)list_
)
771 * @list_: list to peek at
773 * Peek an &sk_buff. Unlike most other operations you _MUST_
774 * be careful with this one. A peek leaves the buffer on the
775 * list and someone else may run off with it. You must hold
776 * the appropriate locks or have a private queue to do this.
778 * Returns %NULL for an empty list or a pointer to the tail element.
779 * The reference count is not incremented and the reference is therefore
780 * volatile. Use with caution.
782 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
784 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
785 if (list
== (struct sk_buff
*)list_
)
791 * skb_queue_len - get queue length
792 * @list_: list to measure
794 * Return the length of an &sk_buff queue.
796 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
802 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
803 * @list: queue to initialize
805 * This initializes only the list and queue length aspects of
806 * an sk_buff_head object. This allows to initialize the list
807 * aspects of an sk_buff_head without reinitializing things like
808 * the spinlock. It can also be used for on-stack sk_buff_head
809 * objects where the spinlock is known to not be used.
811 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
813 list
->prev
= list
->next
= (struct sk_buff
*)list
;
818 * This function creates a split out lock class for each invocation;
819 * this is needed for now since a whole lot of users of the skb-queue
820 * infrastructure in drivers have different locking usage (in hardirq)
821 * than the networking core (in softirq only). In the long run either the
822 * network layer or drivers should need annotation to consolidate the
823 * main types of usage into 3 classes.
825 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
827 spin_lock_init(&list
->lock
);
828 __skb_queue_head_init(list
);
831 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
832 struct lock_class_key
*class)
834 skb_queue_head_init(list
);
835 lockdep_set_class(&list
->lock
, class);
839 * Insert an sk_buff on a list.
841 * The "__skb_xxxx()" functions are the non-atomic ones that
842 * can only be called with interrupts disabled.
844 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
845 static inline void __skb_insert(struct sk_buff
*newsk
,
846 struct sk_buff
*prev
, struct sk_buff
*next
,
847 struct sk_buff_head
*list
)
851 next
->prev
= prev
->next
= newsk
;
855 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
856 struct sk_buff
*prev
,
857 struct sk_buff
*next
)
859 struct sk_buff
*first
= list
->next
;
860 struct sk_buff
*last
= list
->prev
;
870 * skb_queue_splice - join two skb lists, this is designed for stacks
871 * @list: the new list to add
872 * @head: the place to add it in the first list
874 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
875 struct sk_buff_head
*head
)
877 if (!skb_queue_empty(list
)) {
878 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
879 head
->qlen
+= list
->qlen
;
884 * skb_queue_splice - join two skb lists and reinitialise the emptied list
885 * @list: the new list to add
886 * @head: the place to add it in the first list
888 * The list at @list is reinitialised
890 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
891 struct sk_buff_head
*head
)
893 if (!skb_queue_empty(list
)) {
894 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
895 head
->qlen
+= list
->qlen
;
896 __skb_queue_head_init(list
);
901 * skb_queue_splice_tail - join two skb lists, each list being a queue
902 * @list: the new list to add
903 * @head: the place to add it in the first list
905 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
906 struct sk_buff_head
*head
)
908 if (!skb_queue_empty(list
)) {
909 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
910 head
->qlen
+= list
->qlen
;
915 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
916 * @list: the new list to add
917 * @head: the place to add it in the first list
919 * Each of the lists is a queue.
920 * The list at @list is reinitialised
922 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
923 struct sk_buff_head
*head
)
925 if (!skb_queue_empty(list
)) {
926 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
927 head
->qlen
+= list
->qlen
;
928 __skb_queue_head_init(list
);
933 * __skb_queue_after - queue a buffer at the list head
935 * @prev: place after this buffer
936 * @newsk: buffer to queue
938 * Queue a buffer int the middle of a list. This function takes no locks
939 * and you must therefore hold required locks before calling it.
941 * A buffer cannot be placed on two lists at the same time.
943 static inline void __skb_queue_after(struct sk_buff_head
*list
,
944 struct sk_buff
*prev
,
945 struct sk_buff
*newsk
)
947 __skb_insert(newsk
, prev
, prev
->next
, list
);
950 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
951 struct sk_buff_head
*list
);
953 static inline void __skb_queue_before(struct sk_buff_head
*list
,
954 struct sk_buff
*next
,
955 struct sk_buff
*newsk
)
957 __skb_insert(newsk
, next
->prev
, next
, list
);
961 * __skb_queue_head - queue a buffer at the list head
963 * @newsk: buffer to queue
965 * Queue a buffer at the start of a list. This function takes no locks
966 * and you must therefore hold required locks before calling it.
968 * A buffer cannot be placed on two lists at the same time.
970 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
971 static inline void __skb_queue_head(struct sk_buff_head
*list
,
972 struct sk_buff
*newsk
)
974 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
978 * __skb_queue_tail - queue a buffer at the list tail
980 * @newsk: buffer to queue
982 * Queue a buffer at the end of a list. This function takes no locks
983 * and you must therefore hold required locks before calling it.
985 * A buffer cannot be placed on two lists at the same time.
987 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
988 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
989 struct sk_buff
*newsk
)
991 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
995 * remove sk_buff from list. _Must_ be called atomically, and with
998 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
999 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1001 struct sk_buff
*next
, *prev
;
1006 skb
->next
= skb
->prev
= NULL
;
1012 * __skb_dequeue - remove from the head of the queue
1013 * @list: list to dequeue from
1015 * Remove the head of the list. This function does not take any locks
1016 * so must be used with appropriate locks held only. The head item is
1017 * returned or %NULL if the list is empty.
1019 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1020 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1022 struct sk_buff
*skb
= skb_peek(list
);
1024 __skb_unlink(skb
, list
);
1029 * __skb_dequeue_tail - remove from the tail of the queue
1030 * @list: list to dequeue from
1032 * Remove the tail of the list. This function does not take any locks
1033 * so must be used with appropriate locks held only. The tail item is
1034 * returned or %NULL if the list is empty.
1036 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1037 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1039 struct sk_buff
*skb
= skb_peek_tail(list
);
1041 __skb_unlink(skb
, list
);
1046 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1048 return skb
->data_len
;
1051 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1053 return skb
->len
- skb
->data_len
;
1056 static inline int skb_pagelen(const struct sk_buff
*skb
)
1060 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1061 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1062 return len
+ skb_headlen(skb
);
1065 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1066 struct page
*page
, int off
, int size
)
1068 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1071 frag
->page_offset
= off
;
1073 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1076 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1079 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1080 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frags(skb))
1081 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1083 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1084 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1086 return skb
->head
+ skb
->tail
;
1089 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1091 skb
->tail
= skb
->data
- skb
->head
;
1094 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1096 skb_reset_tail_pointer(skb
);
1097 skb
->tail
+= offset
;
1099 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1100 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1105 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1107 skb
->tail
= skb
->data
;
1110 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1112 skb
->tail
= skb
->data
+ offset
;
1115 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1118 * Add data to an sk_buff
1120 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1121 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1123 unsigned char *tmp
= skb_tail_pointer(skb
);
1124 SKB_LINEAR_ASSERT(skb
);
1130 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1131 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1138 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1139 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1142 BUG_ON(skb
->len
< skb
->data_len
);
1143 return skb
->data
+= len
;
1146 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1148 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1150 if (len
> skb_headlen(skb
) &&
1151 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1154 return skb
->data
+= len
;
1157 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1159 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1162 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1164 if (likely(len
<= skb_headlen(skb
)))
1166 if (unlikely(len
> skb
->len
))
1168 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1172 * skb_headroom - bytes at buffer head
1173 * @skb: buffer to check
1175 * Return the number of bytes of free space at the head of an &sk_buff.
1177 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1179 return skb
->data
- skb
->head
;
1183 * skb_tailroom - bytes at buffer end
1184 * @skb: buffer to check
1186 * Return the number of bytes of free space at the tail of an sk_buff
1188 static inline int skb_tailroom(const struct sk_buff
*skb
)
1190 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1194 * skb_reserve - adjust headroom
1195 * @skb: buffer to alter
1196 * @len: bytes to move
1198 * Increase the headroom of an empty &sk_buff by reducing the tail
1199 * room. This is only allowed for an empty buffer.
1201 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1207 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1208 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1210 return skb
->head
+ skb
->transport_header
;
1213 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1215 skb
->transport_header
= skb
->data
- skb
->head
;
1218 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1221 skb_reset_transport_header(skb
);
1222 skb
->transport_header
+= offset
;
1225 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1227 return skb
->head
+ skb
->network_header
;
1230 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1232 skb
->network_header
= skb
->data
- skb
->head
;
1235 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1237 skb_reset_network_header(skb
);
1238 skb
->network_header
+= offset
;
1241 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1243 return skb
->head
+ skb
->mac_header
;
1246 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1248 return skb
->mac_header
!= ~0U;
1251 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1253 skb
->mac_header
= skb
->data
- skb
->head
;
1256 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1258 skb_reset_mac_header(skb
);
1259 skb
->mac_header
+= offset
;
1262 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1264 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1266 return skb
->transport_header
;
1269 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1271 skb
->transport_header
= skb
->data
;
1274 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1277 skb
->transport_header
= skb
->data
+ offset
;
1280 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1282 return skb
->network_header
;
1285 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1287 skb
->network_header
= skb
->data
;
1290 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1292 skb
->network_header
= skb
->data
+ offset
;
1295 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1297 return skb
->mac_header
;
1300 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1302 return skb
->mac_header
!= NULL
;
1305 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1307 skb
->mac_header
= skb
->data
;
1310 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1312 skb
->mac_header
= skb
->data
+ offset
;
1314 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1316 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1318 return skb_transport_header(skb
) - skb
->data
;
1321 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1323 return skb
->transport_header
- skb
->network_header
;
1326 static inline int skb_network_offset(const struct sk_buff
*skb
)
1328 return skb_network_header(skb
) - skb
->data
;
1332 * CPUs often take a performance hit when accessing unaligned memory
1333 * locations. The actual performance hit varies, it can be small if the
1334 * hardware handles it or large if we have to take an exception and fix it
1337 * Since an ethernet header is 14 bytes network drivers often end up with
1338 * the IP header at an unaligned offset. The IP header can be aligned by
1339 * shifting the start of the packet by 2 bytes. Drivers should do this
1342 * skb_reserve(skb, NET_IP_ALIGN);
1344 * The downside to this alignment of the IP header is that the DMA is now
1345 * unaligned. On some architectures the cost of an unaligned DMA is high
1346 * and this cost outweighs the gains made by aligning the IP header.
1348 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1351 #ifndef NET_IP_ALIGN
1352 #define NET_IP_ALIGN 2
1356 * The networking layer reserves some headroom in skb data (via
1357 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1358 * the header has to grow. In the default case, if the header has to grow
1359 * 32 bytes or less we avoid the reallocation.
1361 * Unfortunately this headroom changes the DMA alignment of the resulting
1362 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1363 * on some architectures. An architecture can override this value,
1364 * perhaps setting it to a cacheline in size (since that will maintain
1365 * cacheline alignment of the DMA). It must be a power of 2.
1367 * Various parts of the networking layer expect at least 32 bytes of
1368 * headroom, you should not reduce this.
1371 #define NET_SKB_PAD 32
1374 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1376 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1378 if (unlikely(skb
->data_len
)) {
1383 skb_set_tail_pointer(skb
, len
);
1386 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1388 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1391 return ___pskb_trim(skb
, len
);
1392 __skb_trim(skb
, len
);
1396 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1398 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1402 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1403 * @skb: buffer to alter
1406 * This is identical to pskb_trim except that the caller knows that
1407 * the skb is not cloned so we should never get an error due to out-
1410 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1412 int err
= pskb_trim(skb
, len
);
1417 * skb_orphan - orphan a buffer
1418 * @skb: buffer to orphan
1420 * If a buffer currently has an owner then we call the owner's
1421 * destructor function and make the @skb unowned. The buffer continues
1422 * to exist but is no longer charged to its former owner.
1424 static inline void skb_orphan(struct sk_buff
*skb
)
1426 if (skb
->destructor
)
1427 skb
->destructor(skb
);
1428 skb
->destructor
= NULL
;
1433 * __skb_queue_purge - empty a list
1434 * @list: list to empty
1436 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1437 * the list and one reference dropped. This function does not take the
1438 * list lock and the caller must hold the relevant locks to use it.
1440 extern void skb_queue_purge(struct sk_buff_head
*list
);
1441 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1443 struct sk_buff
*skb
;
1444 while ((skb
= __skb_dequeue(list
)) != NULL
)
1449 * __dev_alloc_skb - allocate an skbuff for receiving
1450 * @length: length to allocate
1451 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1453 * Allocate a new &sk_buff and assign it a usage count of one. The
1454 * buffer has unspecified headroom built in. Users should allocate
1455 * the headroom they think they need without accounting for the
1456 * built in space. The built in space is used for optimisations.
1458 * %NULL is returned if there is no free memory.
1460 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1463 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1465 skb_reserve(skb
, NET_SKB_PAD
);
1469 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1471 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1472 unsigned int length
, gfp_t gfp_mask
);
1475 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1476 * @dev: network device to receive on
1477 * @length: length to allocate
1479 * Allocate a new &sk_buff and assign it a usage count of one. The
1480 * buffer has unspecified headroom built in. Users should allocate
1481 * the headroom they think they need without accounting for the
1482 * built in space. The built in space is used for optimisations.
1484 * %NULL is returned if there is no free memory. Although this function
1485 * allocates memory it can be called from an interrupt.
1487 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1488 unsigned int length
)
1490 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1493 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
1494 unsigned int length
)
1496 struct sk_buff
*skb
= netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
);
1498 if (NET_IP_ALIGN
&& skb
)
1499 skb_reserve(skb
, NET_IP_ALIGN
);
1503 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1506 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1507 * @dev: network device to receive on
1509 * Allocate a new page node local to the specified device.
1511 * %NULL is returned if there is no free memory.
1513 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1515 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1518 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1524 * skb_clone_writable - is the header of a clone writable
1525 * @skb: buffer to check
1526 * @len: length up to which to write
1528 * Returns true if modifying the header part of the cloned buffer
1529 * does not requires the data to be copied.
1531 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1533 return !skb_header_cloned(skb
) &&
1534 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1537 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1542 if (headroom
< NET_SKB_PAD
)
1543 headroom
= NET_SKB_PAD
;
1544 if (headroom
> skb_headroom(skb
))
1545 delta
= headroom
- skb_headroom(skb
);
1547 if (delta
|| cloned
)
1548 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1554 * skb_cow - copy header of skb when it is required
1555 * @skb: buffer to cow
1556 * @headroom: needed headroom
1558 * If the skb passed lacks sufficient headroom or its data part
1559 * is shared, data is reallocated. If reallocation fails, an error
1560 * is returned and original skb is not changed.
1562 * The result is skb with writable area skb->head...skb->tail
1563 * and at least @headroom of space at head.
1565 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1567 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1571 * skb_cow_head - skb_cow but only making the head writable
1572 * @skb: buffer to cow
1573 * @headroom: needed headroom
1575 * This function is identical to skb_cow except that we replace the
1576 * skb_cloned check by skb_header_cloned. It should be used when
1577 * you only need to push on some header and do not need to modify
1580 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1582 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1586 * skb_padto - pad an skbuff up to a minimal size
1587 * @skb: buffer to pad
1588 * @len: minimal length
1590 * Pads up a buffer to ensure the trailing bytes exist and are
1591 * blanked. If the buffer already contains sufficient data it
1592 * is untouched. Otherwise it is extended. Returns zero on
1593 * success. The skb is freed on error.
1596 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1598 unsigned int size
= skb
->len
;
1599 if (likely(size
>= len
))
1601 return skb_pad(skb
, len
- size
);
1604 static inline int skb_add_data(struct sk_buff
*skb
,
1605 char __user
*from
, int copy
)
1607 const int off
= skb
->len
;
1609 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1611 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1614 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1617 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1620 __skb_trim(skb
, off
);
1624 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1625 struct page
*page
, int off
)
1628 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1630 return page
== frag
->page
&&
1631 off
== frag
->page_offset
+ frag
->size
;
1636 static inline int __skb_linearize(struct sk_buff
*skb
)
1638 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1642 * skb_linearize - convert paged skb to linear one
1643 * @skb: buffer to linarize
1645 * If there is no free memory -ENOMEM is returned, otherwise zero
1646 * is returned and the old skb data released.
1648 static inline int skb_linearize(struct sk_buff
*skb
)
1650 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1654 * skb_linearize_cow - make sure skb is linear and writable
1655 * @skb: buffer to process
1657 * If there is no free memory -ENOMEM is returned, otherwise zero
1658 * is returned and the old skb data released.
1660 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1662 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1663 __skb_linearize(skb
) : 0;
1667 * skb_postpull_rcsum - update checksum for received skb after pull
1668 * @skb: buffer to update
1669 * @start: start of data before pull
1670 * @len: length of data pulled
1672 * After doing a pull on a received packet, you need to call this to
1673 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1674 * CHECKSUM_NONE so that it can be recomputed from scratch.
1677 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1678 const void *start
, unsigned int len
)
1680 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1681 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1684 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1687 * pskb_trim_rcsum - trim received skb and update checksum
1688 * @skb: buffer to trim
1691 * This is exactly the same as pskb_trim except that it ensures the
1692 * checksum of received packets are still valid after the operation.
1695 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1697 if (likely(len
>= skb
->len
))
1699 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1700 skb
->ip_summed
= CHECKSUM_NONE
;
1701 return __pskb_trim(skb
, len
);
1704 #define skb_queue_walk(queue, skb) \
1705 for (skb = (queue)->next; \
1706 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1709 #define skb_queue_walk_safe(queue, skb, tmp) \
1710 for (skb = (queue)->next, tmp = skb->next; \
1711 skb != (struct sk_buff *)(queue); \
1712 skb = tmp, tmp = skb->next)
1714 #define skb_queue_walk_from(queue, skb) \
1715 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1718 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1719 for (tmp = skb->next; \
1720 skb != (struct sk_buff *)(queue); \
1721 skb = tmp, tmp = skb->next)
1723 #define skb_queue_reverse_walk(queue, skb) \
1724 for (skb = (queue)->prev; \
1725 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1729 static inline bool skb_has_frags(const struct sk_buff
*skb
)
1731 return skb_shinfo(skb
)->frag_list
!= NULL
;
1734 static inline void skb_frag_list_init(struct sk_buff
*skb
)
1736 skb_shinfo(skb
)->frag_list
= NULL
;
1739 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
1741 frag
->next
= skb_shinfo(skb
)->frag_list
;
1742 skb_shinfo(skb
)->frag_list
= frag
;
1745 #define skb_walk_frags(skb, iter) \
1746 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
1748 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1749 int *peeked
, int *err
);
1750 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1751 int noblock
, int *err
);
1752 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1753 struct poll_table_struct
*wait
);
1754 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1755 int offset
, struct iovec
*to
,
1757 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1760 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1762 const struct iovec
*from
,
1765 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
1767 const struct iovec
*to
,
1770 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1771 extern void skb_free_datagram_locked(struct sock
*sk
,
1772 struct sk_buff
*skb
);
1773 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1774 unsigned int flags
);
1775 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1776 int len
, __wsum csum
);
1777 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1779 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1780 const void *from
, int len
);
1781 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1782 int offset
, u8
*to
, int len
,
1784 extern int skb_splice_bits(struct sk_buff
*skb
,
1785 unsigned int offset
,
1786 struct pipe_inode_info
*pipe
,
1788 unsigned int flags
);
1789 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1790 extern void skb_split(struct sk_buff
*skb
,
1791 struct sk_buff
*skb1
, const u32 len
);
1792 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1795 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1797 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1798 int len
, void *buffer
)
1800 int hlen
= skb_headlen(skb
);
1802 if (hlen
- offset
>= len
)
1803 return skb
->data
+ offset
;
1805 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1811 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1813 const unsigned int len
)
1815 memcpy(to
, skb
->data
, len
);
1818 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1819 const int offset
, void *to
,
1820 const unsigned int len
)
1822 memcpy(to
, skb
->data
+ offset
, len
);
1825 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1827 const unsigned int len
)
1829 memcpy(skb
->data
, from
, len
);
1832 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1835 const unsigned int len
)
1837 memcpy(skb
->data
+ offset
, from
, len
);
1840 extern void skb_init(void);
1842 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1848 * skb_get_timestamp - get timestamp from a skb
1849 * @skb: skb to get stamp from
1850 * @stamp: pointer to struct timeval to store stamp in
1852 * Timestamps are stored in the skb as offsets to a base timestamp.
1853 * This function converts the offset back to a struct timeval and stores
1856 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1857 struct timeval
*stamp
)
1859 *stamp
= ktime_to_timeval(skb
->tstamp
);
1862 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1863 struct timespec
*stamp
)
1865 *stamp
= ktime_to_timespec(skb
->tstamp
);
1868 static inline void __net_timestamp(struct sk_buff
*skb
)
1870 skb
->tstamp
= ktime_get_real();
1873 static inline ktime_t
net_timedelta(ktime_t t
)
1875 return ktime_sub(ktime_get_real(), t
);
1878 static inline ktime_t
net_invalid_timestamp(void)
1880 return ktime_set(0, 0);
1884 * skb_tstamp_tx - queue clone of skb with send time stamps
1885 * @orig_skb: the original outgoing packet
1886 * @hwtstamps: hardware time stamps, may be NULL if not available
1888 * If the skb has a socket associated, then this function clones the
1889 * skb (thus sharing the actual data and optional structures), stores
1890 * the optional hardware time stamping information (if non NULL) or
1891 * generates a software time stamp (otherwise), then queues the clone
1892 * to the error queue of the socket. Errors are silently ignored.
1894 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1895 struct skb_shared_hwtstamps
*hwtstamps
);
1897 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1898 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1900 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1902 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1906 * skb_checksum_complete - Calculate checksum of an entire packet
1907 * @skb: packet to process
1909 * This function calculates the checksum over the entire packet plus
1910 * the value of skb->csum. The latter can be used to supply the
1911 * checksum of a pseudo header as used by TCP/UDP. It returns the
1914 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1915 * this function can be used to verify that checksum on received
1916 * packets. In that case the function should return zero if the
1917 * checksum is correct. In particular, this function will return zero
1918 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1919 * hardware has already verified the correctness of the checksum.
1921 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1923 return skb_csum_unnecessary(skb
) ?
1924 0 : __skb_checksum_complete(skb
);
1927 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1928 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1929 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1931 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1932 nf_conntrack_destroy(nfct
);
1934 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1937 atomic_inc(&nfct
->use
);
1939 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1942 atomic_inc(&skb
->users
);
1944 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1950 #ifdef CONFIG_BRIDGE_NETFILTER
1951 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1953 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1956 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1959 atomic_inc(&nf_bridge
->use
);
1961 #endif /* CONFIG_BRIDGE_NETFILTER */
1962 static inline void nf_reset(struct sk_buff
*skb
)
1964 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1965 nf_conntrack_put(skb
->nfct
);
1967 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1968 skb
->nfct_reasm
= NULL
;
1970 #ifdef CONFIG_BRIDGE_NETFILTER
1971 nf_bridge_put(skb
->nf_bridge
);
1972 skb
->nf_bridge
= NULL
;
1976 /* Note: This doesn't put any conntrack and bridge info in dst. */
1977 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1979 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1980 dst
->nfct
= src
->nfct
;
1981 nf_conntrack_get(src
->nfct
);
1982 dst
->nfctinfo
= src
->nfctinfo
;
1983 dst
->nfct_reasm
= src
->nfct_reasm
;
1984 nf_conntrack_get_reasm(src
->nfct_reasm
);
1986 #ifdef CONFIG_BRIDGE_NETFILTER
1987 dst
->nf_bridge
= src
->nf_bridge
;
1988 nf_bridge_get(src
->nf_bridge
);
1992 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1994 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1995 nf_conntrack_put(dst
->nfct
);
1996 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1998 #ifdef CONFIG_BRIDGE_NETFILTER
1999 nf_bridge_put(dst
->nf_bridge
);
2001 __nf_copy(dst
, src
);
2004 #ifdef CONFIG_NETWORK_SECMARK
2005 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2007 to
->secmark
= from
->secmark
;
2010 static inline void skb_init_secmark(struct sk_buff
*skb
)
2015 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2018 static inline void skb_init_secmark(struct sk_buff
*skb
)
2022 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2024 skb
->queue_mapping
= queue_mapping
;
2027 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2029 return skb
->queue_mapping
;
2032 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2034 to
->queue_mapping
= from
->queue_mapping
;
2037 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2039 skb
->queue_mapping
= rx_queue
+ 1;
2042 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2044 return skb
->queue_mapping
- 1;
2047 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2049 return (skb
->queue_mapping
!= 0);
2052 extern u16
skb_tx_hash(const struct net_device
*dev
,
2053 const struct sk_buff
*skb
);
2056 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2061 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2067 static inline int skb_is_gso(const struct sk_buff
*skb
)
2069 return skb_shinfo(skb
)->gso_size
;
2072 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2074 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2077 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2079 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2081 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2082 * wanted then gso_type will be set. */
2083 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2084 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2085 __skb_warn_lro_forwarding(skb
);
2091 static inline void skb_forward_csum(struct sk_buff
*skb
)
2093 /* Unfortunately we don't support this one. Any brave souls? */
2094 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2095 skb
->ip_summed
= CHECKSUM_NONE
;
2098 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2099 #endif /* __KERNEL__ */
2100 #endif /* _LINUX_SKBUFF_H */