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];
208 /* We divide dataref into two halves. The higher 16 bits hold references
209 * to the payload part of skb->data. The lower 16 bits hold references to
210 * the entire skb->data. A clone of a headerless skb holds the length of
211 * the header in skb->hdr_len.
213 * All users must obey the rule that the skb->data reference count must be
214 * greater than or equal to the payload reference count.
216 * Holding a reference to the payload part means that the user does not
217 * care about modifications to the header part of skb->data.
219 #define SKB_DATAREF_SHIFT 16
220 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
224 SKB_FCLONE_UNAVAILABLE
,
230 SKB_GSO_TCPV4
= 1 << 0,
231 SKB_GSO_UDP
= 1 << 1,
233 /* This indicates the skb is from an untrusted source. */
234 SKB_GSO_DODGY
= 1 << 2,
236 /* This indicates the tcp segment has CWR set. */
237 SKB_GSO_TCP_ECN
= 1 << 3,
239 SKB_GSO_TCPV6
= 1 << 4,
242 #if BITS_PER_LONG > 32
243 #define NET_SKBUFF_DATA_USES_OFFSET 1
246 #ifdef NET_SKBUFF_DATA_USES_OFFSET
247 typedef unsigned int sk_buff_data_t
;
249 typedef unsigned char *sk_buff_data_t
;
253 * struct sk_buff - socket buffer
254 * @next: Next buffer in list
255 * @prev: Previous buffer in list
256 * @sk: Socket we are owned by
257 * @tstamp: Time we arrived
258 * @dev: Device we arrived on/are leaving by
259 * @transport_header: Transport layer header
260 * @network_header: Network layer header
261 * @mac_header: Link layer header
262 * @dst: destination entry
263 * @sp: the security path, used for xfrm
264 * @cb: Control buffer. Free for use by every layer. Put private vars here
265 * @len: Length of actual data
266 * @data_len: Data length
267 * @mac_len: Length of link layer header
268 * @hdr_len: writable header length of cloned skb
269 * @csum: Checksum (must include start/offset pair)
270 * @csum_start: Offset from skb->head where checksumming should start
271 * @csum_offset: Offset from csum_start where checksum should be stored
272 * @local_df: allow local fragmentation
273 * @cloned: Head may be cloned (check refcnt to be sure)
274 * @nohdr: Payload reference only, must not modify header
275 * @pkt_type: Packet class
276 * @fclone: skbuff clone status
277 * @ip_summed: Driver fed us an IP checksum
278 * @priority: Packet queueing priority
279 * @users: User count - see {datagram,tcp}.c
280 * @protocol: Packet protocol from driver
281 * @truesize: Buffer size
282 * @head: Head of buffer
283 * @data: Data head pointer
284 * @tail: Tail pointer
286 * @destructor: Destruct function
287 * @mark: Generic packet mark
288 * @nfct: Associated connection, if any
289 * @ipvs_property: skbuff is owned by ipvs
290 * @peeked: this packet has been seen already, so stats have been
291 * done for it, don't do them again
292 * @nf_trace: netfilter packet trace flag
293 * @nfctinfo: Relationship of this skb to the connection
294 * @nfct_reasm: netfilter conntrack re-assembly pointer
295 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
296 * @iif: ifindex of device we arrived on
297 * @queue_mapping: Queue mapping for multiqueue devices
298 * @tc_index: Traffic control index
299 * @tc_verd: traffic control verdict
300 * @ndisc_nodetype: router type (from link layer)
301 * @do_not_encrypt: set to prevent encryption of this frame
302 * @requeue: set to indicate that the wireless core should attempt
303 * a software retry on this frame if we failed to
304 * receive an ACK for it
305 * @dma_cookie: a cookie to one of several possible DMA operations
306 * done by skb DMA functions
307 * @secmark: security marking
308 * @vlan_tci: vlan tag control information
312 /* These two members must be first. */
313 struct sk_buff
*next
;
314 struct sk_buff
*prev
;
318 struct net_device
*dev
;
321 struct dst_entry
*dst
;
322 struct rtable
*rtable
;
328 * This is the control buffer. It is free to use for every
329 * layer. Please put your private variables there. If you
330 * want to keep them across layers you have to do a skb_clone()
331 * first. This is owned by whoever has the skb queued ATM.
359 void (*destructor
)(struct sk_buff
*skb
);
360 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
361 struct nf_conntrack
*nfct
;
362 struct sk_buff
*nfct_reasm
;
364 #ifdef CONFIG_BRIDGE_NETFILTER
365 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 */
376 #ifdef CONFIG_IPV6_NDISC_NODETYPE
377 __u8 ndisc_nodetype
:2;
379 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
380 __u8 do_not_encrypt
:1;
383 /* 0/13/14 bit hole */
385 #ifdef CONFIG_NET_DMA
386 dma_cookie_t dma_cookie
;
388 #ifdef CONFIG_NETWORK_SECMARK
396 sk_buff_data_t transport_header
;
397 sk_buff_data_t network_header
;
398 sk_buff_data_t mac_header
;
399 /* These elements must be at the end, see alloc_skb() for details. */
404 unsigned int truesize
;
410 * Handling routines are only of interest to the kernel
412 #include <linux/slab.h>
414 #include <asm/system.h>
416 #ifdef CONFIG_HAS_DMA
417 #include <linux/dma-mapping.h>
418 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
419 enum dma_data_direction dir
);
420 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
421 enum dma_data_direction dir
);
424 extern void kfree_skb(struct sk_buff
*skb
);
425 extern void consume_skb(struct sk_buff
*skb
);
426 extern void __kfree_skb(struct sk_buff
*skb
);
427 extern struct sk_buff
*__alloc_skb(unsigned int size
,
428 gfp_t priority
, int fclone
, int node
);
429 static inline struct sk_buff
*alloc_skb(unsigned int size
,
432 return __alloc_skb(size
, priority
, 0, -1);
435 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
438 return __alloc_skb(size
, priority
, 1, -1);
441 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
443 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
444 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
446 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
448 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
450 extern int pskb_expand_head(struct sk_buff
*skb
,
451 int nhead
, int ntail
,
453 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
454 unsigned int headroom
);
455 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
456 int newheadroom
, int newtailroom
,
458 extern int skb_to_sgvec(struct sk_buff
*skb
,
459 struct scatterlist
*sg
, int offset
,
461 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
462 struct sk_buff
**trailer
);
463 extern int skb_pad(struct sk_buff
*skb
, int pad
);
464 #define dev_kfree_skb(a) consume_skb(a)
465 #define dev_consume_skb(a) kfree_skb_clean(a)
466 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
468 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
471 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
472 int getfrag(void *from
, char *to
, int offset
,
473 int len
,int odd
, struct sk_buff
*skb
),
474 void *from
, int length
);
481 __u32 stepped_offset
;
482 struct sk_buff
*root_skb
;
483 struct sk_buff
*cur_skb
;
487 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
488 unsigned int from
, unsigned int to
,
489 struct skb_seq_state
*st
);
490 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
491 struct skb_seq_state
*st
);
492 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
494 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
495 unsigned int to
, struct ts_config
*config
,
496 struct ts_state
*state
);
498 #ifdef NET_SKBUFF_DATA_USES_OFFSET
499 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
501 return skb
->head
+ skb
->end
;
504 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
511 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
513 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
515 return &skb_shinfo(skb
)->hwtstamps
;
518 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
520 return &skb_shinfo(skb
)->tx_flags
;
524 * skb_queue_empty - check if a queue is empty
527 * Returns true if the queue is empty, false otherwise.
529 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
531 return list
->next
== (struct sk_buff
*)list
;
535 * skb_queue_is_last - check if skb is the last entry in the queue
539 * Returns true if @skb is the last buffer on the list.
541 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
542 const struct sk_buff
*skb
)
544 return (skb
->next
== (struct sk_buff
*) list
);
548 * skb_queue_is_first - check if skb is the first entry in the queue
552 * Returns true if @skb is the first buffer on the list.
554 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
555 const struct sk_buff
*skb
)
557 return (skb
->prev
== (struct sk_buff
*) list
);
561 * skb_queue_next - return the next packet in the queue
563 * @skb: current buffer
565 * Return the next packet in @list after @skb. It is only valid to
566 * call this if skb_queue_is_last() evaluates to false.
568 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
569 const struct sk_buff
*skb
)
571 /* This BUG_ON may seem severe, but if we just return then we
572 * are going to dereference garbage.
574 BUG_ON(skb_queue_is_last(list
, skb
));
579 * skb_queue_prev - return the prev packet in the queue
581 * @skb: current buffer
583 * Return the prev packet in @list before @skb. It is only valid to
584 * call this if skb_queue_is_first() evaluates to false.
586 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
587 const struct sk_buff
*skb
)
589 /* This BUG_ON may seem severe, but if we just return then we
590 * are going to dereference garbage.
592 BUG_ON(skb_queue_is_first(list
, skb
));
597 * skb_get - reference buffer
598 * @skb: buffer to reference
600 * Makes another reference to a socket buffer and returns a pointer
603 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
605 atomic_inc(&skb
->users
);
610 * If users == 1, we are the only owner and are can avoid redundant
615 * skb_cloned - is the buffer a clone
616 * @skb: buffer to check
618 * Returns true if the buffer was generated with skb_clone() and is
619 * one of multiple shared copies of the buffer. Cloned buffers are
620 * shared data so must not be written to under normal circumstances.
622 static inline int skb_cloned(const struct sk_buff
*skb
)
624 return skb
->cloned
&&
625 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
629 * skb_header_cloned - is the header a clone
630 * @skb: buffer to check
632 * Returns true if modifying the header part of the buffer requires
633 * the data to be copied.
635 static inline int skb_header_cloned(const struct sk_buff
*skb
)
642 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
643 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
648 * skb_header_release - release reference to header
649 * @skb: buffer to operate on
651 * Drop a reference to the header part of the buffer. This is done
652 * by acquiring a payload reference. You must not read from the header
653 * part of skb->data after this.
655 static inline void skb_header_release(struct sk_buff
*skb
)
659 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
663 * skb_shared - is the buffer shared
664 * @skb: buffer to check
666 * Returns true if more than one person has a reference to this
669 static inline int skb_shared(const struct sk_buff
*skb
)
671 return atomic_read(&skb
->users
) != 1;
675 * skb_share_check - check if buffer is shared and if so clone it
676 * @skb: buffer to check
677 * @pri: priority for memory allocation
679 * If the buffer is shared the buffer is cloned and the old copy
680 * drops a reference. A new clone with a single reference is returned.
681 * If the buffer is not shared the original buffer is returned. When
682 * being called from interrupt status or with spinlocks held pri must
685 * NULL is returned on a memory allocation failure.
687 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
690 might_sleep_if(pri
& __GFP_WAIT
);
691 if (skb_shared(skb
)) {
692 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
700 * Copy shared buffers into a new sk_buff. We effectively do COW on
701 * packets to handle cases where we have a local reader and forward
702 * and a couple of other messy ones. The normal one is tcpdumping
703 * a packet thats being forwarded.
707 * skb_unshare - make a copy of a shared buffer
708 * @skb: buffer to check
709 * @pri: priority for memory allocation
711 * If the socket buffer is a clone then this function creates a new
712 * copy of the data, drops a reference count on the old copy and returns
713 * the new copy with the reference count at 1. If the buffer is not a clone
714 * the original buffer is returned. When called with a spinlock held or
715 * from interrupt state @pri must be %GFP_ATOMIC
717 * %NULL is returned on a memory allocation failure.
719 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
722 might_sleep_if(pri
& __GFP_WAIT
);
723 if (skb_cloned(skb
)) {
724 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
725 kfree_skb(skb
); /* Free our shared copy */
733 * @list_: list to peek at
735 * Peek an &sk_buff. Unlike most other operations you _MUST_
736 * be careful with this one. A peek leaves the buffer on the
737 * list and someone else may run off with it. You must hold
738 * the appropriate locks or have a private queue to do this.
740 * Returns %NULL for an empty list or a pointer to the head element.
741 * The reference count is not incremented and the reference is therefore
742 * volatile. Use with caution.
744 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
746 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
747 if (list
== (struct sk_buff
*)list_
)
754 * @list_: list to peek at
756 * Peek an &sk_buff. Unlike most other operations you _MUST_
757 * be careful with this one. A peek leaves the buffer on the
758 * list and someone else may run off with it. You must hold
759 * the appropriate locks or have a private queue to do this.
761 * Returns %NULL for an empty list or a pointer to the tail element.
762 * The reference count is not incremented and the reference is therefore
763 * volatile. Use with caution.
765 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
767 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
768 if (list
== (struct sk_buff
*)list_
)
774 * skb_queue_len - get queue length
775 * @list_: list to measure
777 * Return the length of an &sk_buff queue.
779 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
785 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
786 * @list: queue to initialize
788 * This initializes only the list and queue length aspects of
789 * an sk_buff_head object. This allows to initialize the list
790 * aspects of an sk_buff_head without reinitializing things like
791 * the spinlock. It can also be used for on-stack sk_buff_head
792 * objects where the spinlock is known to not be used.
794 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
796 list
->prev
= list
->next
= (struct sk_buff
*)list
;
801 * This function creates a split out lock class for each invocation;
802 * this is needed for now since a whole lot of users of the skb-queue
803 * infrastructure in drivers have different locking usage (in hardirq)
804 * than the networking core (in softirq only). In the long run either the
805 * network layer or drivers should need annotation to consolidate the
806 * main types of usage into 3 classes.
808 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
810 spin_lock_init(&list
->lock
);
811 __skb_queue_head_init(list
);
814 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
815 struct lock_class_key
*class)
817 skb_queue_head_init(list
);
818 lockdep_set_class(&list
->lock
, class);
822 * Insert an sk_buff on a list.
824 * The "__skb_xxxx()" functions are the non-atomic ones that
825 * can only be called with interrupts disabled.
827 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
828 static inline void __skb_insert(struct sk_buff
*newsk
,
829 struct sk_buff
*prev
, struct sk_buff
*next
,
830 struct sk_buff_head
*list
)
834 next
->prev
= prev
->next
= newsk
;
838 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
839 struct sk_buff
*prev
,
840 struct sk_buff
*next
)
842 struct sk_buff
*first
= list
->next
;
843 struct sk_buff
*last
= list
->prev
;
853 * skb_queue_splice - join two skb lists, this is designed for stacks
854 * @list: the new list to add
855 * @head: the place to add it in the first list
857 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
858 struct sk_buff_head
*head
)
860 if (!skb_queue_empty(list
)) {
861 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
862 head
->qlen
+= list
->qlen
;
867 * skb_queue_splice - join two skb lists and reinitialise the emptied list
868 * @list: the new list to add
869 * @head: the place to add it in the first list
871 * The list at @list is reinitialised
873 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
874 struct sk_buff_head
*head
)
876 if (!skb_queue_empty(list
)) {
877 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
878 head
->qlen
+= list
->qlen
;
879 __skb_queue_head_init(list
);
884 * skb_queue_splice_tail - join two skb lists, each list being a queue
885 * @list: the new list to add
886 * @head: the place to add it in the first list
888 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
889 struct sk_buff_head
*head
)
891 if (!skb_queue_empty(list
)) {
892 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
893 head
->qlen
+= list
->qlen
;
898 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
899 * @list: the new list to add
900 * @head: the place to add it in the first list
902 * Each of the lists is a queue.
903 * The list at @list is reinitialised
905 static inline void skb_queue_splice_tail_init(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
;
911 __skb_queue_head_init(list
);
916 * __skb_queue_after - queue a buffer at the list head
918 * @prev: place after this buffer
919 * @newsk: buffer to queue
921 * Queue a buffer int the middle of a list. This function takes no locks
922 * and you must therefore hold required locks before calling it.
924 * A buffer cannot be placed on two lists at the same time.
926 static inline void __skb_queue_after(struct sk_buff_head
*list
,
927 struct sk_buff
*prev
,
928 struct sk_buff
*newsk
)
930 __skb_insert(newsk
, prev
, prev
->next
, list
);
933 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
934 struct sk_buff_head
*list
);
936 static inline void __skb_queue_before(struct sk_buff_head
*list
,
937 struct sk_buff
*next
,
938 struct sk_buff
*newsk
)
940 __skb_insert(newsk
, next
->prev
, next
, list
);
944 * __skb_queue_head - queue a buffer at the list head
946 * @newsk: buffer to queue
948 * Queue a buffer at the start of a list. This function takes no locks
949 * and you must therefore hold required locks before calling it.
951 * A buffer cannot be placed on two lists at the same time.
953 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
954 static inline void __skb_queue_head(struct sk_buff_head
*list
,
955 struct sk_buff
*newsk
)
957 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
961 * __skb_queue_tail - queue a buffer at the list tail
963 * @newsk: buffer to queue
965 * Queue a buffer at the end 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_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
971 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
972 struct sk_buff
*newsk
)
974 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
978 * remove sk_buff from list. _Must_ be called atomically, and with
981 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
982 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
984 struct sk_buff
*next
, *prev
;
989 skb
->next
= skb
->prev
= NULL
;
995 * __skb_dequeue - remove from the head of the queue
996 * @list: list to dequeue from
998 * Remove the head of the list. This function does not take any locks
999 * so must be used with appropriate locks held only. The head item is
1000 * returned or %NULL if the list is empty.
1002 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1003 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1005 struct sk_buff
*skb
= skb_peek(list
);
1007 __skb_unlink(skb
, list
);
1012 * __skb_dequeue_tail - remove from the tail of the queue
1013 * @list: list to dequeue from
1015 * Remove the tail of the list. This function does not take any locks
1016 * so must be used with appropriate locks held only. The tail item is
1017 * returned or %NULL if the list is empty.
1019 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1020 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1022 struct sk_buff
*skb
= skb_peek_tail(list
);
1024 __skb_unlink(skb
, list
);
1029 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1031 return skb
->data_len
;
1034 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1036 return skb
->len
- skb
->data_len
;
1039 static inline int skb_pagelen(const struct sk_buff
*skb
)
1043 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1044 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1045 return len
+ skb_headlen(skb
);
1048 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1049 struct page
*page
, int off
, int size
)
1051 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1054 frag
->page_offset
= off
;
1056 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1059 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1062 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1063 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1064 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1066 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1067 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1069 return skb
->head
+ skb
->tail
;
1072 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1074 skb
->tail
= skb
->data
- skb
->head
;
1077 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1079 skb_reset_tail_pointer(skb
);
1080 skb
->tail
+= offset
;
1082 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1083 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1088 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1090 skb
->tail
= skb
->data
;
1093 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1095 skb
->tail
= skb
->data
+ offset
;
1098 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1101 * Add data to an sk_buff
1103 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1104 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1106 unsigned char *tmp
= skb_tail_pointer(skb
);
1107 SKB_LINEAR_ASSERT(skb
);
1113 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1114 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1121 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1122 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1125 BUG_ON(skb
->len
< skb
->data_len
);
1126 return skb
->data
+= len
;
1129 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1131 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1133 if (len
> skb_headlen(skb
) &&
1134 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1137 return skb
->data
+= len
;
1140 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1142 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1145 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1147 if (likely(len
<= skb_headlen(skb
)))
1149 if (unlikely(len
> skb
->len
))
1151 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1155 * skb_headroom - bytes at buffer head
1156 * @skb: buffer to check
1158 * Return the number of bytes of free space at the head of an &sk_buff.
1160 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1162 return skb
->data
- skb
->head
;
1166 * skb_tailroom - bytes at buffer end
1167 * @skb: buffer to check
1169 * Return the number of bytes of free space at the tail of an sk_buff
1171 static inline int skb_tailroom(const struct sk_buff
*skb
)
1173 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1177 * skb_reserve - adjust headroom
1178 * @skb: buffer to alter
1179 * @len: bytes to move
1181 * Increase the headroom of an empty &sk_buff by reducing the tail
1182 * room. This is only allowed for an empty buffer.
1184 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1190 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1191 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1193 return skb
->head
+ skb
->transport_header
;
1196 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1198 skb
->transport_header
= skb
->data
- skb
->head
;
1201 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1204 skb_reset_transport_header(skb
);
1205 skb
->transport_header
+= offset
;
1208 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1210 return skb
->head
+ skb
->network_header
;
1213 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1215 skb
->network_header
= skb
->data
- skb
->head
;
1218 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1220 skb_reset_network_header(skb
);
1221 skb
->network_header
+= offset
;
1224 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1226 return skb
->head
+ skb
->mac_header
;
1229 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1231 return skb
->mac_header
!= ~0U;
1234 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1236 skb
->mac_header
= skb
->data
- skb
->head
;
1239 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1241 skb_reset_mac_header(skb
);
1242 skb
->mac_header
+= offset
;
1245 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1247 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1249 return skb
->transport_header
;
1252 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1254 skb
->transport_header
= skb
->data
;
1257 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1260 skb
->transport_header
= skb
->data
+ offset
;
1263 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1265 return skb
->network_header
;
1268 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1270 skb
->network_header
= skb
->data
;
1273 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1275 skb
->network_header
= skb
->data
+ offset
;
1278 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1280 return skb
->mac_header
;
1283 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1285 return skb
->mac_header
!= NULL
;
1288 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1290 skb
->mac_header
= skb
->data
;
1293 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1295 skb
->mac_header
= skb
->data
+ offset
;
1297 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1299 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1301 return skb_transport_header(skb
) - skb
->data
;
1304 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1306 return skb
->transport_header
- skb
->network_header
;
1309 static inline int skb_network_offset(const struct sk_buff
*skb
)
1311 return skb_network_header(skb
) - skb
->data
;
1315 * CPUs often take a performance hit when accessing unaligned memory
1316 * locations. The actual performance hit varies, it can be small if the
1317 * hardware handles it or large if we have to take an exception and fix it
1320 * Since an ethernet header is 14 bytes network drivers often end up with
1321 * the IP header at an unaligned offset. The IP header can be aligned by
1322 * shifting the start of the packet by 2 bytes. Drivers should do this
1325 * skb_reserve(NET_IP_ALIGN);
1327 * The downside to this alignment of the IP header is that the DMA is now
1328 * unaligned. On some architectures the cost of an unaligned DMA is high
1329 * and this cost outweighs the gains made by aligning the IP header.
1331 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1334 #ifndef NET_IP_ALIGN
1335 #define NET_IP_ALIGN 2
1339 * The networking layer reserves some headroom in skb data (via
1340 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1341 * the header has to grow. In the default case, if the header has to grow
1342 * 32 bytes or less we avoid the reallocation.
1344 * Unfortunately this headroom changes the DMA alignment of the resulting
1345 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1346 * on some architectures. An architecture can override this value,
1347 * perhaps setting it to a cacheline in size (since that will maintain
1348 * cacheline alignment of the DMA). It must be a power of 2.
1350 * Various parts of the networking layer expect at least 32 bytes of
1351 * headroom, you should not reduce this.
1354 #define NET_SKB_PAD 32
1357 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1359 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1361 if (unlikely(skb
->data_len
)) {
1366 skb_set_tail_pointer(skb
, len
);
1369 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1371 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1374 return ___pskb_trim(skb
, len
);
1375 __skb_trim(skb
, len
);
1379 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1381 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1385 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1386 * @skb: buffer to alter
1389 * This is identical to pskb_trim except that the caller knows that
1390 * the skb is not cloned so we should never get an error due to out-
1393 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1395 int err
= pskb_trim(skb
, len
);
1400 * skb_orphan - orphan a buffer
1401 * @skb: buffer to orphan
1403 * If a buffer currently has an owner then we call the owner's
1404 * destructor function and make the @skb unowned. The buffer continues
1405 * to exist but is no longer charged to its former owner.
1407 static inline void skb_orphan(struct sk_buff
*skb
)
1409 if (skb
->destructor
)
1410 skb
->destructor(skb
);
1411 skb
->destructor
= NULL
;
1416 * __skb_queue_purge - empty a list
1417 * @list: list to empty
1419 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1420 * the list and one reference dropped. This function does not take the
1421 * list lock and the caller must hold the relevant locks to use it.
1423 extern void skb_queue_purge(struct sk_buff_head
*list
);
1424 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1426 struct sk_buff
*skb
;
1427 while ((skb
= __skb_dequeue(list
)) != NULL
)
1432 * __dev_alloc_skb - allocate an skbuff for receiving
1433 * @length: length to allocate
1434 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1436 * Allocate a new &sk_buff and assign it a usage count of one. The
1437 * buffer has unspecified headroom built in. Users should allocate
1438 * the headroom they think they need without accounting for the
1439 * built in space. The built in space is used for optimisations.
1441 * %NULL is returned if there is no free memory.
1443 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1446 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1448 skb_reserve(skb
, NET_SKB_PAD
);
1452 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1454 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1455 unsigned int length
, gfp_t gfp_mask
);
1458 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1459 * @dev: network device to receive on
1460 * @length: length to allocate
1462 * Allocate a new &sk_buff and assign it a usage count of one. The
1463 * buffer has unspecified headroom built in. Users should allocate
1464 * the headroom they think they need without accounting for the
1465 * built in space. The built in space is used for optimisations.
1467 * %NULL is returned if there is no free memory. Although this function
1468 * allocates memory it can be called from an interrupt.
1470 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1471 unsigned int length
)
1473 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1476 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1479 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1480 * @dev: network device to receive on
1482 * Allocate a new page node local to the specified device.
1484 * %NULL is returned if there is no free memory.
1486 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1488 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1491 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1497 * skb_clone_writable - is the header of a clone writable
1498 * @skb: buffer to check
1499 * @len: length up to which to write
1501 * Returns true if modifying the header part of the cloned buffer
1502 * does not requires the data to be copied.
1504 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1506 return !skb_header_cloned(skb
) &&
1507 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1510 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1515 if (headroom
< NET_SKB_PAD
)
1516 headroom
= NET_SKB_PAD
;
1517 if (headroom
> skb_headroom(skb
))
1518 delta
= headroom
- skb_headroom(skb
);
1520 if (delta
|| cloned
)
1521 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1527 * skb_cow - copy header of skb when it is required
1528 * @skb: buffer to cow
1529 * @headroom: needed headroom
1531 * If the skb passed lacks sufficient headroom or its data part
1532 * is shared, data is reallocated. If reallocation fails, an error
1533 * is returned and original skb is not changed.
1535 * The result is skb with writable area skb->head...skb->tail
1536 * and at least @headroom of space at head.
1538 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1540 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1544 * skb_cow_head - skb_cow but only making the head writable
1545 * @skb: buffer to cow
1546 * @headroom: needed headroom
1548 * This function is identical to skb_cow except that we replace the
1549 * skb_cloned check by skb_header_cloned. It should be used when
1550 * you only need to push on some header and do not need to modify
1553 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1555 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1559 * skb_padto - pad an skbuff up to a minimal size
1560 * @skb: buffer to pad
1561 * @len: minimal length
1563 * Pads up a buffer to ensure the trailing bytes exist and are
1564 * blanked. If the buffer already contains sufficient data it
1565 * is untouched. Otherwise it is extended. Returns zero on
1566 * success. The skb is freed on error.
1569 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1571 unsigned int size
= skb
->len
;
1572 if (likely(size
>= len
))
1574 return skb_pad(skb
, len
- size
);
1577 static inline int skb_add_data(struct sk_buff
*skb
,
1578 char __user
*from
, int copy
)
1580 const int off
= skb
->len
;
1582 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1584 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1587 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1590 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1593 __skb_trim(skb
, off
);
1597 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1598 struct page
*page
, int off
)
1601 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1603 return page
== frag
->page
&&
1604 off
== frag
->page_offset
+ frag
->size
;
1609 static inline int __skb_linearize(struct sk_buff
*skb
)
1611 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1615 * skb_linearize - convert paged skb to linear one
1616 * @skb: buffer to linarize
1618 * If there is no free memory -ENOMEM is returned, otherwise zero
1619 * is returned and the old skb data released.
1621 static inline int skb_linearize(struct sk_buff
*skb
)
1623 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1627 * skb_linearize_cow - make sure skb is linear and writable
1628 * @skb: buffer to process
1630 * If there is no free memory -ENOMEM is returned, otherwise zero
1631 * is returned and the old skb data released.
1633 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1635 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1636 __skb_linearize(skb
) : 0;
1640 * skb_postpull_rcsum - update checksum for received skb after pull
1641 * @skb: buffer to update
1642 * @start: start of data before pull
1643 * @len: length of data pulled
1645 * After doing a pull on a received packet, you need to call this to
1646 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1647 * CHECKSUM_NONE so that it can be recomputed from scratch.
1650 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1651 const void *start
, unsigned int len
)
1653 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1654 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1657 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1660 * pskb_trim_rcsum - trim received skb and update checksum
1661 * @skb: buffer to trim
1664 * This is exactly the same as pskb_trim except that it ensures the
1665 * checksum of received packets are still valid after the operation.
1668 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1670 if (likely(len
>= skb
->len
))
1672 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1673 skb
->ip_summed
= CHECKSUM_NONE
;
1674 return __pskb_trim(skb
, len
);
1677 #define skb_queue_walk(queue, skb) \
1678 for (skb = (queue)->next; \
1679 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1682 #define skb_queue_walk_safe(queue, skb, tmp) \
1683 for (skb = (queue)->next, tmp = skb->next; \
1684 skb != (struct sk_buff *)(queue); \
1685 skb = tmp, tmp = skb->next)
1687 #define skb_queue_walk_from(queue, skb) \
1688 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1691 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1692 for (tmp = skb->next; \
1693 skb != (struct sk_buff *)(queue); \
1694 skb = tmp, tmp = skb->next)
1696 #define skb_queue_reverse_walk(queue, skb) \
1697 for (skb = (queue)->prev; \
1698 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1702 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1703 int *peeked
, int *err
);
1704 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1705 int noblock
, int *err
);
1706 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1707 struct poll_table_struct
*wait
);
1708 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1709 int offset
, struct iovec
*to
,
1711 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1714 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1718 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1719 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1720 unsigned int flags
);
1721 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1722 int len
, __wsum csum
);
1723 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1725 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1726 const void *from
, int len
);
1727 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1728 int offset
, u8
*to
, int len
,
1730 extern int skb_splice_bits(struct sk_buff
*skb
,
1731 unsigned int offset
,
1732 struct pipe_inode_info
*pipe
,
1734 unsigned int flags
);
1735 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1736 extern void skb_split(struct sk_buff
*skb
,
1737 struct sk_buff
*skb1
, const u32 len
);
1738 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1741 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1743 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1744 int len
, void *buffer
)
1746 int hlen
= skb_headlen(skb
);
1748 if (hlen
- offset
>= len
)
1749 return skb
->data
+ offset
;
1751 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1757 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1759 const unsigned int len
)
1761 memcpy(to
, skb
->data
, len
);
1764 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1765 const int offset
, void *to
,
1766 const unsigned int len
)
1768 memcpy(to
, skb
->data
+ offset
, len
);
1771 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1773 const unsigned int len
)
1775 memcpy(skb
->data
, from
, len
);
1778 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1781 const unsigned int len
)
1783 memcpy(skb
->data
+ offset
, from
, len
);
1786 extern void skb_init(void);
1788 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1794 * skb_get_timestamp - get timestamp from a skb
1795 * @skb: skb to get stamp from
1796 * @stamp: pointer to struct timeval to store stamp in
1798 * Timestamps are stored in the skb as offsets to a base timestamp.
1799 * This function converts the offset back to a struct timeval and stores
1802 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1803 struct timeval
*stamp
)
1805 *stamp
= ktime_to_timeval(skb
->tstamp
);
1808 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1809 struct timespec
*stamp
)
1811 *stamp
= ktime_to_timespec(skb
->tstamp
);
1814 static inline void __net_timestamp(struct sk_buff
*skb
)
1816 skb
->tstamp
= ktime_get_real();
1819 static inline ktime_t
net_timedelta(ktime_t t
)
1821 return ktime_sub(ktime_get_real(), t
);
1824 static inline ktime_t
net_invalid_timestamp(void)
1826 return ktime_set(0, 0);
1830 * skb_tstamp_tx - queue clone of skb with send time stamps
1831 * @orig_skb: the original outgoing packet
1832 * @hwtstamps: hardware time stamps, may be NULL if not available
1834 * If the skb has a socket associated, then this function clones the
1835 * skb (thus sharing the actual data and optional structures), stores
1836 * the optional hardware time stamping information (if non NULL) or
1837 * generates a software time stamp (otherwise), then queues the clone
1838 * to the error queue of the socket. Errors are silently ignored.
1840 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1841 struct skb_shared_hwtstamps
*hwtstamps
);
1843 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1844 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1846 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1848 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1852 * skb_checksum_complete - Calculate checksum of an entire packet
1853 * @skb: packet to process
1855 * This function calculates the checksum over the entire packet plus
1856 * the value of skb->csum. The latter can be used to supply the
1857 * checksum of a pseudo header as used by TCP/UDP. It returns the
1860 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1861 * this function can be used to verify that checksum on received
1862 * packets. In that case the function should return zero if the
1863 * checksum is correct. In particular, this function will return zero
1864 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1865 * hardware has already verified the correctness of the checksum.
1867 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1869 return skb_csum_unnecessary(skb
) ?
1870 0 : __skb_checksum_complete(skb
);
1873 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1874 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1875 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1877 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1878 nf_conntrack_destroy(nfct
);
1880 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1883 atomic_inc(&nfct
->use
);
1885 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1888 atomic_inc(&skb
->users
);
1890 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1896 #ifdef CONFIG_BRIDGE_NETFILTER
1897 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1899 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1902 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1905 atomic_inc(&nf_bridge
->use
);
1907 #endif /* CONFIG_BRIDGE_NETFILTER */
1908 static inline void nf_reset(struct sk_buff
*skb
)
1910 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1911 nf_conntrack_put(skb
->nfct
);
1913 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1914 skb
->nfct_reasm
= NULL
;
1916 #ifdef CONFIG_BRIDGE_NETFILTER
1917 nf_bridge_put(skb
->nf_bridge
);
1918 skb
->nf_bridge
= NULL
;
1922 /* Note: This doesn't put any conntrack and bridge info in dst. */
1923 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1925 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1926 dst
->nfct
= src
->nfct
;
1927 nf_conntrack_get(src
->nfct
);
1928 dst
->nfctinfo
= src
->nfctinfo
;
1929 dst
->nfct_reasm
= src
->nfct_reasm
;
1930 nf_conntrack_get_reasm(src
->nfct_reasm
);
1932 #ifdef CONFIG_BRIDGE_NETFILTER
1933 dst
->nf_bridge
= src
->nf_bridge
;
1934 nf_bridge_get(src
->nf_bridge
);
1938 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1940 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1941 nf_conntrack_put(dst
->nfct
);
1942 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1944 #ifdef CONFIG_BRIDGE_NETFILTER
1945 nf_bridge_put(dst
->nf_bridge
);
1947 __nf_copy(dst
, src
);
1950 #ifdef CONFIG_NETWORK_SECMARK
1951 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1953 to
->secmark
= from
->secmark
;
1956 static inline void skb_init_secmark(struct sk_buff
*skb
)
1961 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1964 static inline void skb_init_secmark(struct sk_buff
*skb
)
1968 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1970 skb
->queue_mapping
= queue_mapping
;
1973 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
1975 return skb
->queue_mapping
;
1978 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1980 to
->queue_mapping
= from
->queue_mapping
;
1983 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
1985 skb
->queue_mapping
= rx_queue
+ 1;
1988 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
1990 return skb
->queue_mapping
- 1;
1993 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
1995 return (skb
->queue_mapping
!= 0);
1998 extern u16
skb_tx_hash(const struct net_device
*dev
,
1999 const struct sk_buff
*skb
);
2002 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2007 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2013 static inline int skb_is_gso(const struct sk_buff
*skb
)
2015 return skb_shinfo(skb
)->gso_size
;
2018 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2020 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2023 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2025 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2027 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2028 * wanted then gso_type will be set. */
2029 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2030 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2031 __skb_warn_lro_forwarding(skb
);
2037 static inline void skb_forward_csum(struct sk_buff
*skb
)
2039 /* Unfortunately we don't support this one. Any brave souls? */
2040 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2041 skb
->ip_summed
= CHECKSUM_NONE
;
2044 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2045 #endif /* __KERNEL__ */
2046 #endif /* _LINUX_SKBUFF_H */