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 #ifdef CONFIG_HAS_DMA
195 /* Warning: this field is not always filled in (UFO)! */
196 unsigned short gso_segs
;
197 unsigned short gso_type
;
199 union skb_shared_tx tx_flags
;
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
];
206 /* Intermediate layers must ensure that destructor_arg
207 * remains valid until skb destructor */
208 void * destructor_arg
;
211 /* We divide dataref into two halves. The higher 16 bits hold references
212 * to the payload part of skb->data. The lower 16 bits hold references to
213 * the entire skb->data. A clone of a headerless skb holds the length of
214 * the header in skb->hdr_len.
216 * All users must obey the rule that the skb->data reference count must be
217 * greater than or equal to the payload reference count.
219 * Holding a reference to the payload part means that the user does not
220 * care about modifications to the header part of skb->data.
222 #define SKB_DATAREF_SHIFT 16
223 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
227 SKB_FCLONE_UNAVAILABLE
,
233 SKB_GSO_TCPV4
= 1 << 0,
234 SKB_GSO_UDP
= 1 << 1,
236 /* This indicates the skb is from an untrusted source. */
237 SKB_GSO_DODGY
= 1 << 2,
239 /* This indicates the tcp segment has CWR set. */
240 SKB_GSO_TCP_ECN
= 1 << 3,
242 SKB_GSO_TCPV6
= 1 << 4,
244 SKB_GSO_FCOE
= 1 << 5,
247 #if BITS_PER_LONG > 32
248 #define NET_SKBUFF_DATA_USES_OFFSET 1
251 #ifdef NET_SKBUFF_DATA_USES_OFFSET
252 typedef unsigned int sk_buff_data_t
;
254 typedef unsigned char *sk_buff_data_t
;
258 * struct sk_buff - socket buffer
259 * @next: Next buffer in list
260 * @prev: Previous buffer in list
261 * @sk: Socket we are owned by
262 * @tstamp: Time we arrived
263 * @dev: Device we arrived on/are leaving by
264 * @transport_header: Transport layer header
265 * @network_header: Network layer header
266 * @mac_header: Link layer header
267 * @dst: destination entry
268 * @sp: the security path, used for xfrm
269 * @cb: Control buffer. Free for use by every layer. Put private vars here
270 * @len: Length of actual data
271 * @data_len: Data length
272 * @mac_len: Length of link layer header
273 * @hdr_len: writable header length of cloned skb
274 * @csum: Checksum (must include start/offset pair)
275 * @csum_start: Offset from skb->head where checksumming should start
276 * @csum_offset: Offset from csum_start where checksum should be stored
277 * @local_df: allow local fragmentation
278 * @cloned: Head may be cloned (check refcnt to be sure)
279 * @nohdr: Payload reference only, must not modify header
280 * @pkt_type: Packet class
281 * @fclone: skbuff clone status
282 * @ip_summed: Driver fed us an IP checksum
283 * @priority: Packet queueing priority
284 * @users: User count - see {datagram,tcp}.c
285 * @protocol: Packet protocol from driver
286 * @truesize: Buffer size
287 * @head: Head of buffer
288 * @data: Data head pointer
289 * @tail: Tail pointer
291 * @destructor: Destruct function
292 * @mark: Generic packet mark
293 * @nfct: Associated connection, if any
294 * @ipvs_property: skbuff is owned by ipvs
295 * @peeked: this packet has been seen already, so stats have been
296 * done for it, don't do them again
297 * @nf_trace: netfilter packet trace flag
298 * @nfctinfo: Relationship of this skb to the connection
299 * @nfct_reasm: netfilter conntrack re-assembly pointer
300 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
301 * @iif: ifindex of device we arrived on
302 * @queue_mapping: Queue mapping for multiqueue devices
303 * @tc_index: Traffic control index
304 * @tc_verd: traffic control verdict
305 * @ndisc_nodetype: router type (from link layer)
306 * @do_not_encrypt: set to prevent encryption of this frame
307 * @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.
358 void (*destructor
)(struct sk_buff
*skb
);
359 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
360 struct nf_conntrack
*nfct
;
361 struct sk_buff
*nfct_reasm
;
363 #ifdef CONFIG_BRIDGE_NETFILTER
364 struct nf_bridge_info
*nf_bridge
;
369 #ifdef CONFIG_NET_SCHED
370 __u16 tc_index
; /* traffic control index */
371 #ifdef CONFIG_NET_CLS_ACT
372 __u16 tc_verd
; /* traffic control verdict */
375 #ifdef CONFIG_IPV6_NDISC_NODETYPE
376 __u8 ndisc_nodetype
:2;
378 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
379 __u8 do_not_encrypt
:1;
381 /* 0/13/14 bit hole */
383 #ifdef CONFIG_NET_DMA
384 dma_cookie_t dma_cookie
;
386 #ifdef CONFIG_NETWORK_SECMARK
394 sk_buff_data_t transport_header
;
395 sk_buff_data_t network_header
;
396 sk_buff_data_t mac_header
;
397 /* These elements must be at the end, see alloc_skb() for details. */
402 unsigned int truesize
;
408 * Handling routines are only of interest to the kernel
410 #include <linux/slab.h>
412 #include <asm/system.h>
414 #ifdef CONFIG_HAS_DMA
415 #include <linux/dma-mapping.h>
416 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
417 enum dma_data_direction dir
);
418 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
419 enum dma_data_direction dir
);
422 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
424 return (struct dst_entry
*)skb
->_skb_dst
;
427 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
429 skb
->_skb_dst
= (unsigned long)dst
;
432 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
434 return (struct rtable
*)skb_dst(skb
);
437 extern void kfree_skb(struct sk_buff
*skb
);
438 extern void consume_skb(struct sk_buff
*skb
);
439 extern void __kfree_skb(struct sk_buff
*skb
);
440 extern struct sk_buff
*__alloc_skb(unsigned int size
,
441 gfp_t priority
, int fclone
, int node
);
442 static inline struct sk_buff
*alloc_skb(unsigned int size
,
445 return __alloc_skb(size
, priority
, 0, -1);
448 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
451 return __alloc_skb(size
, priority
, 1, -1);
454 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
456 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
457 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
459 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
461 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
463 extern int pskb_expand_head(struct sk_buff
*skb
,
464 int nhead
, int ntail
,
466 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
467 unsigned int headroom
);
468 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
469 int newheadroom
, int newtailroom
,
471 extern int skb_to_sgvec(struct sk_buff
*skb
,
472 struct scatterlist
*sg
, int offset
,
474 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
475 struct sk_buff
**trailer
);
476 extern int skb_pad(struct sk_buff
*skb
, int pad
);
477 #define dev_kfree_skb(a) consume_skb(a)
478 #define dev_consume_skb(a) kfree_skb_clean(a)
479 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
481 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
484 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
485 int getfrag(void *from
, char *to
, int offset
,
486 int len
,int odd
, struct sk_buff
*skb
),
487 void *from
, int length
);
494 __u32 stepped_offset
;
495 struct sk_buff
*root_skb
;
496 struct sk_buff
*cur_skb
;
500 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
501 unsigned int from
, unsigned int to
,
502 struct skb_seq_state
*st
);
503 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
504 struct skb_seq_state
*st
);
505 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
507 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
508 unsigned int to
, struct ts_config
*config
,
509 struct ts_state
*state
);
511 #ifdef NET_SKBUFF_DATA_USES_OFFSET
512 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
514 return skb
->head
+ skb
->end
;
517 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
524 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
526 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
528 return &skb_shinfo(skb
)->hwtstamps
;
531 static inline union skb_shared_tx
*skb_tx(struct sk_buff
*skb
)
533 return &skb_shinfo(skb
)->tx_flags
;
537 * skb_queue_empty - check if a queue is empty
540 * Returns true if the queue is empty, false otherwise.
542 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
544 return list
->next
== (struct sk_buff
*)list
;
548 * skb_queue_is_last - check if skb is the last entry in the queue
552 * Returns true if @skb is the last buffer on the list.
554 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
555 const struct sk_buff
*skb
)
557 return (skb
->next
== (struct sk_buff
*) list
);
561 * skb_queue_is_first - check if skb is the first entry in the queue
565 * Returns true if @skb is the first buffer on the list.
567 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
568 const struct sk_buff
*skb
)
570 return (skb
->prev
== (struct sk_buff
*) list
);
574 * skb_queue_next - return the next packet in the queue
576 * @skb: current buffer
578 * Return the next packet in @list after @skb. It is only valid to
579 * call this if skb_queue_is_last() evaluates to false.
581 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
582 const struct sk_buff
*skb
)
584 /* This BUG_ON may seem severe, but if we just return then we
585 * are going to dereference garbage.
587 BUG_ON(skb_queue_is_last(list
, skb
));
592 * skb_queue_prev - return the prev packet in the queue
594 * @skb: current buffer
596 * Return the prev packet in @list before @skb. It is only valid to
597 * call this if skb_queue_is_first() evaluates to false.
599 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
600 const struct sk_buff
*skb
)
602 /* This BUG_ON may seem severe, but if we just return then we
603 * are going to dereference garbage.
605 BUG_ON(skb_queue_is_first(list
, skb
));
610 * skb_get - reference buffer
611 * @skb: buffer to reference
613 * Makes another reference to a socket buffer and returns a pointer
616 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
618 atomic_inc(&skb
->users
);
623 * If users == 1, we are the only owner and are can avoid redundant
628 * skb_cloned - is the buffer a clone
629 * @skb: buffer to check
631 * Returns true if the buffer was generated with skb_clone() and is
632 * one of multiple shared copies of the buffer. Cloned buffers are
633 * shared data so must not be written to under normal circumstances.
635 static inline int skb_cloned(const struct sk_buff
*skb
)
637 return skb
->cloned
&&
638 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
642 * skb_header_cloned - is the header a clone
643 * @skb: buffer to check
645 * Returns true if modifying the header part of the buffer requires
646 * the data to be copied.
648 static inline int skb_header_cloned(const struct sk_buff
*skb
)
655 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
656 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
661 * skb_header_release - release reference to header
662 * @skb: buffer to operate on
664 * Drop a reference to the header part of the buffer. This is done
665 * by acquiring a payload reference. You must not read from the header
666 * part of skb->data after this.
668 static inline void skb_header_release(struct sk_buff
*skb
)
672 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
676 * skb_shared - is the buffer shared
677 * @skb: buffer to check
679 * Returns true if more than one person has a reference to this
682 static inline int skb_shared(const struct sk_buff
*skb
)
684 return atomic_read(&skb
->users
) != 1;
688 * skb_share_check - check if buffer is shared and if so clone it
689 * @skb: buffer to check
690 * @pri: priority for memory allocation
692 * If the buffer is shared the buffer is cloned and the old copy
693 * drops a reference. A new clone with a single reference is returned.
694 * If the buffer is not shared the original buffer is returned. When
695 * being called from interrupt status or with spinlocks held pri must
698 * NULL is returned on a memory allocation failure.
700 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
703 might_sleep_if(pri
& __GFP_WAIT
);
704 if (skb_shared(skb
)) {
705 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
713 * Copy shared buffers into a new sk_buff. We effectively do COW on
714 * packets to handle cases where we have a local reader and forward
715 * and a couple of other messy ones. The normal one is tcpdumping
716 * a packet thats being forwarded.
720 * skb_unshare - make a copy of a shared buffer
721 * @skb: buffer to check
722 * @pri: priority for memory allocation
724 * If the socket buffer is a clone then this function creates a new
725 * copy of the data, drops a reference count on the old copy and returns
726 * the new copy with the reference count at 1. If the buffer is not a clone
727 * the original buffer is returned. When called with a spinlock held or
728 * from interrupt state @pri must be %GFP_ATOMIC
730 * %NULL is returned on a memory allocation failure.
732 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
735 might_sleep_if(pri
& __GFP_WAIT
);
736 if (skb_cloned(skb
)) {
737 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
738 kfree_skb(skb
); /* Free our shared copy */
746 * @list_: list to peek at
748 * Peek an &sk_buff. Unlike most other operations you _MUST_
749 * be careful with this one. A peek leaves the buffer on the
750 * list and someone else may run off with it. You must hold
751 * the appropriate locks or have a private queue to do this.
753 * Returns %NULL for an empty list or a pointer to the head element.
754 * The reference count is not incremented and the reference is therefore
755 * volatile. Use with caution.
757 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
759 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
760 if (list
== (struct sk_buff
*)list_
)
767 * @list_: list to peek at
769 * Peek an &sk_buff. Unlike most other operations you _MUST_
770 * be careful with this one. A peek leaves the buffer on the
771 * list and someone else may run off with it. You must hold
772 * the appropriate locks or have a private queue to do this.
774 * Returns %NULL for an empty list or a pointer to the tail element.
775 * The reference count is not incremented and the reference is therefore
776 * volatile. Use with caution.
778 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
780 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
781 if (list
== (struct sk_buff
*)list_
)
787 * skb_queue_len - get queue length
788 * @list_: list to measure
790 * Return the length of an &sk_buff queue.
792 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
798 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
799 * @list: queue to initialize
801 * This initializes only the list and queue length aspects of
802 * an sk_buff_head object. This allows to initialize the list
803 * aspects of an sk_buff_head without reinitializing things like
804 * the spinlock. It can also be used for on-stack sk_buff_head
805 * objects where the spinlock is known to not be used.
807 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
809 list
->prev
= list
->next
= (struct sk_buff
*)list
;
814 * This function creates a split out lock class for each invocation;
815 * this is needed for now since a whole lot of users of the skb-queue
816 * infrastructure in drivers have different locking usage (in hardirq)
817 * than the networking core (in softirq only). In the long run either the
818 * network layer or drivers should need annotation to consolidate the
819 * main types of usage into 3 classes.
821 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
823 spin_lock_init(&list
->lock
);
824 __skb_queue_head_init(list
);
827 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
828 struct lock_class_key
*class)
830 skb_queue_head_init(list
);
831 lockdep_set_class(&list
->lock
, class);
835 * Insert an sk_buff on a list.
837 * The "__skb_xxxx()" functions are the non-atomic ones that
838 * can only be called with interrupts disabled.
840 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
841 static inline void __skb_insert(struct sk_buff
*newsk
,
842 struct sk_buff
*prev
, struct sk_buff
*next
,
843 struct sk_buff_head
*list
)
847 next
->prev
= prev
->next
= newsk
;
851 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
852 struct sk_buff
*prev
,
853 struct sk_buff
*next
)
855 struct sk_buff
*first
= list
->next
;
856 struct sk_buff
*last
= list
->prev
;
866 * skb_queue_splice - join two skb lists, this is designed for stacks
867 * @list: the new list to add
868 * @head: the place to add it in the first list
870 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
871 struct sk_buff_head
*head
)
873 if (!skb_queue_empty(list
)) {
874 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
875 head
->qlen
+= list
->qlen
;
880 * skb_queue_splice - join two skb lists and reinitialise the emptied list
881 * @list: the new list to add
882 * @head: the place to add it in the first list
884 * The list at @list is reinitialised
886 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
887 struct sk_buff_head
*head
)
889 if (!skb_queue_empty(list
)) {
890 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
891 head
->qlen
+= list
->qlen
;
892 __skb_queue_head_init(list
);
897 * skb_queue_splice_tail - join two skb lists, each list being a queue
898 * @list: the new list to add
899 * @head: the place to add it in the first list
901 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
902 struct sk_buff_head
*head
)
904 if (!skb_queue_empty(list
)) {
905 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
906 head
->qlen
+= list
->qlen
;
911 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
912 * @list: the new list to add
913 * @head: the place to add it in the first list
915 * Each of the lists is a queue.
916 * The list at @list is reinitialised
918 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
919 struct sk_buff_head
*head
)
921 if (!skb_queue_empty(list
)) {
922 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
923 head
->qlen
+= list
->qlen
;
924 __skb_queue_head_init(list
);
929 * __skb_queue_after - queue a buffer at the list head
931 * @prev: place after this buffer
932 * @newsk: buffer to queue
934 * Queue a buffer int the middle of a list. This function takes no locks
935 * and you must therefore hold required locks before calling it.
937 * A buffer cannot be placed on two lists at the same time.
939 static inline void __skb_queue_after(struct sk_buff_head
*list
,
940 struct sk_buff
*prev
,
941 struct sk_buff
*newsk
)
943 __skb_insert(newsk
, prev
, prev
->next
, list
);
946 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
947 struct sk_buff_head
*list
);
949 static inline void __skb_queue_before(struct sk_buff_head
*list
,
950 struct sk_buff
*next
,
951 struct sk_buff
*newsk
)
953 __skb_insert(newsk
, next
->prev
, next
, list
);
957 * __skb_queue_head - queue a buffer at the list head
959 * @newsk: buffer to queue
961 * Queue a buffer at the start of a list. This function takes no locks
962 * and you must therefore hold required locks before calling it.
964 * A buffer cannot be placed on two lists at the same time.
966 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
967 static inline void __skb_queue_head(struct sk_buff_head
*list
,
968 struct sk_buff
*newsk
)
970 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
974 * __skb_queue_tail - queue a buffer at the list tail
976 * @newsk: buffer to queue
978 * Queue a buffer at the end of a list. This function takes no locks
979 * and you must therefore hold required locks before calling it.
981 * A buffer cannot be placed on two lists at the same time.
983 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
984 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
985 struct sk_buff
*newsk
)
987 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
991 * remove sk_buff from list. _Must_ be called atomically, and with
994 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
995 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
997 struct sk_buff
*next
, *prev
;
1002 skb
->next
= skb
->prev
= NULL
;
1008 * __skb_dequeue - remove from the head of the queue
1009 * @list: list to dequeue from
1011 * Remove the head of the list. This function does not take any locks
1012 * so must be used with appropriate locks held only. The head item is
1013 * returned or %NULL if the list is empty.
1015 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1016 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1018 struct sk_buff
*skb
= skb_peek(list
);
1020 __skb_unlink(skb
, list
);
1025 * __skb_dequeue_tail - remove from the tail of the queue
1026 * @list: list to dequeue from
1028 * Remove the tail of the list. This function does not take any locks
1029 * so must be used with appropriate locks held only. The tail item is
1030 * returned or %NULL if the list is empty.
1032 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1033 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1035 struct sk_buff
*skb
= skb_peek_tail(list
);
1037 __skb_unlink(skb
, list
);
1042 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
1044 return skb
->data_len
;
1047 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1049 return skb
->len
- skb
->data_len
;
1052 static inline int skb_pagelen(const struct sk_buff
*skb
)
1056 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1057 len
+= skb_shinfo(skb
)->frags
[i
].size
;
1058 return len
+ skb_headlen(skb
);
1061 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1062 struct page
*page
, int off
, int size
)
1064 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1067 frag
->page_offset
= off
;
1069 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1072 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1075 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1076 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frags(skb))
1077 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1079 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1080 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1082 return skb
->head
+ skb
->tail
;
1085 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1087 skb
->tail
= skb
->data
- skb
->head
;
1090 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1092 skb_reset_tail_pointer(skb
);
1093 skb
->tail
+= offset
;
1095 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1096 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1101 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1103 skb
->tail
= skb
->data
;
1106 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1108 skb
->tail
= skb
->data
+ offset
;
1111 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1114 * Add data to an sk_buff
1116 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1117 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1119 unsigned char *tmp
= skb_tail_pointer(skb
);
1120 SKB_LINEAR_ASSERT(skb
);
1126 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1127 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1134 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1135 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1138 BUG_ON(skb
->len
< skb
->data_len
);
1139 return skb
->data
+= len
;
1142 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1144 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1146 if (len
> skb_headlen(skb
) &&
1147 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1150 return skb
->data
+= len
;
1153 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1155 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1158 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1160 if (likely(len
<= skb_headlen(skb
)))
1162 if (unlikely(len
> skb
->len
))
1164 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1168 * skb_headroom - bytes at buffer head
1169 * @skb: buffer to check
1171 * Return the number of bytes of free space at the head of an &sk_buff.
1173 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1175 return skb
->data
- skb
->head
;
1179 * skb_tailroom - bytes at buffer end
1180 * @skb: buffer to check
1182 * Return the number of bytes of free space at the tail of an sk_buff
1184 static inline int skb_tailroom(const struct sk_buff
*skb
)
1186 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1190 * skb_reserve - adjust headroom
1191 * @skb: buffer to alter
1192 * @len: bytes to move
1194 * Increase the headroom of an empty &sk_buff by reducing the tail
1195 * room. This is only allowed for an empty buffer.
1197 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1203 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1204 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1206 return skb
->head
+ skb
->transport_header
;
1209 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1211 skb
->transport_header
= skb
->data
- skb
->head
;
1214 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1217 skb_reset_transport_header(skb
);
1218 skb
->transport_header
+= offset
;
1221 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1223 return skb
->head
+ skb
->network_header
;
1226 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1228 skb
->network_header
= skb
->data
- skb
->head
;
1231 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1233 skb_reset_network_header(skb
);
1234 skb
->network_header
+= offset
;
1237 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1239 return skb
->head
+ skb
->mac_header
;
1242 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1244 return skb
->mac_header
!= ~0U;
1247 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1249 skb
->mac_header
= skb
->data
- skb
->head
;
1252 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1254 skb_reset_mac_header(skb
);
1255 skb
->mac_header
+= offset
;
1258 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1260 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1262 return skb
->transport_header
;
1265 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1267 skb
->transport_header
= skb
->data
;
1270 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1273 skb
->transport_header
= skb
->data
+ offset
;
1276 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1278 return skb
->network_header
;
1281 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1283 skb
->network_header
= skb
->data
;
1286 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1288 skb
->network_header
= skb
->data
+ offset
;
1291 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1293 return skb
->mac_header
;
1296 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1298 return skb
->mac_header
!= NULL
;
1301 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1303 skb
->mac_header
= skb
->data
;
1306 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1308 skb
->mac_header
= skb
->data
+ offset
;
1310 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1312 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1314 return skb_transport_header(skb
) - skb
->data
;
1317 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1319 return skb
->transport_header
- skb
->network_header
;
1322 static inline int skb_network_offset(const struct sk_buff
*skb
)
1324 return skb_network_header(skb
) - skb
->data
;
1328 * CPUs often take a performance hit when accessing unaligned memory
1329 * locations. The actual performance hit varies, it can be small if the
1330 * hardware handles it or large if we have to take an exception and fix it
1333 * Since an ethernet header is 14 bytes network drivers often end up with
1334 * the IP header at an unaligned offset. The IP header can be aligned by
1335 * shifting the start of the packet by 2 bytes. Drivers should do this
1338 * skb_reserve(NET_IP_ALIGN);
1340 * The downside to this alignment of the IP header is that the DMA is now
1341 * unaligned. On some architectures the cost of an unaligned DMA is high
1342 * and this cost outweighs the gains made by aligning the IP header.
1344 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1347 #ifndef NET_IP_ALIGN
1348 #define NET_IP_ALIGN 2
1352 * The networking layer reserves some headroom in skb data (via
1353 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1354 * the header has to grow. In the default case, if the header has to grow
1355 * 32 bytes or less we avoid the reallocation.
1357 * Unfortunately this headroom changes the DMA alignment of the resulting
1358 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1359 * on some architectures. An architecture can override this value,
1360 * perhaps setting it to a cacheline in size (since that will maintain
1361 * cacheline alignment of the DMA). It must be a power of 2.
1363 * Various parts of the networking layer expect at least 32 bytes of
1364 * headroom, you should not reduce this.
1367 #define NET_SKB_PAD 32
1370 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1372 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1374 if (unlikely(skb
->data_len
)) {
1379 skb_set_tail_pointer(skb
, len
);
1382 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1384 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1387 return ___pskb_trim(skb
, len
);
1388 __skb_trim(skb
, len
);
1392 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1394 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1398 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1399 * @skb: buffer to alter
1402 * This is identical to pskb_trim except that the caller knows that
1403 * the skb is not cloned so we should never get an error due to out-
1406 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1408 int err
= pskb_trim(skb
, len
);
1413 * skb_orphan - orphan a buffer
1414 * @skb: buffer to orphan
1416 * If a buffer currently has an owner then we call the owner's
1417 * destructor function and make the @skb unowned. The buffer continues
1418 * to exist but is no longer charged to its former owner.
1420 static inline void skb_orphan(struct sk_buff
*skb
)
1422 if (skb
->destructor
)
1423 skb
->destructor(skb
);
1424 skb
->destructor
= NULL
;
1429 * __skb_queue_purge - empty a list
1430 * @list: list to empty
1432 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1433 * the list and one reference dropped. This function does not take the
1434 * list lock and the caller must hold the relevant locks to use it.
1436 extern void skb_queue_purge(struct sk_buff_head
*list
);
1437 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1439 struct sk_buff
*skb
;
1440 while ((skb
= __skb_dequeue(list
)) != NULL
)
1445 * __dev_alloc_skb - allocate an skbuff for receiving
1446 * @length: length to allocate
1447 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1449 * Allocate a new &sk_buff and assign it a usage count of one. The
1450 * buffer has unspecified headroom built in. Users should allocate
1451 * the headroom they think they need without accounting for the
1452 * built in space. The built in space is used for optimisations.
1454 * %NULL is returned if there is no free memory.
1456 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1459 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1461 skb_reserve(skb
, NET_SKB_PAD
);
1465 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1467 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1468 unsigned int length
, gfp_t gfp_mask
);
1471 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1472 * @dev: network device to receive on
1473 * @length: length to allocate
1475 * Allocate a new &sk_buff and assign it a usage count of one. The
1476 * buffer has unspecified headroom built in. Users should allocate
1477 * the headroom they think they need without accounting for the
1478 * built in space. The built in space is used for optimisations.
1480 * %NULL is returned if there is no free memory. Although this function
1481 * allocates memory it can be called from an interrupt.
1483 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1484 unsigned int length
)
1486 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1489 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1492 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1493 * @dev: network device to receive on
1495 * Allocate a new page node local to the specified device.
1497 * %NULL is returned if there is no free memory.
1499 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1501 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1504 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1510 * skb_clone_writable - is the header of a clone writable
1511 * @skb: buffer to check
1512 * @len: length up to which to write
1514 * Returns true if modifying the header part of the cloned buffer
1515 * does not requires the data to be copied.
1517 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1519 return !skb_header_cloned(skb
) &&
1520 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1523 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1528 if (headroom
< NET_SKB_PAD
)
1529 headroom
= NET_SKB_PAD
;
1530 if (headroom
> skb_headroom(skb
))
1531 delta
= headroom
- skb_headroom(skb
);
1533 if (delta
|| cloned
)
1534 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1540 * skb_cow - copy header of skb when it is required
1541 * @skb: buffer to cow
1542 * @headroom: needed headroom
1544 * If the skb passed lacks sufficient headroom or its data part
1545 * is shared, data is reallocated. If reallocation fails, an error
1546 * is returned and original skb is not changed.
1548 * The result is skb with writable area skb->head...skb->tail
1549 * and at least @headroom of space at head.
1551 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1553 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1557 * skb_cow_head - skb_cow but only making the head writable
1558 * @skb: buffer to cow
1559 * @headroom: needed headroom
1561 * This function is identical to skb_cow except that we replace the
1562 * skb_cloned check by skb_header_cloned. It should be used when
1563 * you only need to push on some header and do not need to modify
1566 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1568 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1572 * skb_padto - pad an skbuff up to a minimal size
1573 * @skb: buffer to pad
1574 * @len: minimal length
1576 * Pads up a buffer to ensure the trailing bytes exist and are
1577 * blanked. If the buffer already contains sufficient data it
1578 * is untouched. Otherwise it is extended. Returns zero on
1579 * success. The skb is freed on error.
1582 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1584 unsigned int size
= skb
->len
;
1585 if (likely(size
>= len
))
1587 return skb_pad(skb
, len
- size
);
1590 static inline int skb_add_data(struct sk_buff
*skb
,
1591 char __user
*from
, int copy
)
1593 const int off
= skb
->len
;
1595 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1597 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1600 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1603 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1606 __skb_trim(skb
, off
);
1610 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1611 struct page
*page
, int off
)
1614 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1616 return page
== frag
->page
&&
1617 off
== frag
->page_offset
+ frag
->size
;
1622 static inline int __skb_linearize(struct sk_buff
*skb
)
1624 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1628 * skb_linearize - convert paged skb to linear one
1629 * @skb: buffer to linarize
1631 * If there is no free memory -ENOMEM is returned, otherwise zero
1632 * is returned and the old skb data released.
1634 static inline int skb_linearize(struct sk_buff
*skb
)
1636 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1640 * skb_linearize_cow - make sure skb is linear and writable
1641 * @skb: buffer to process
1643 * If there is no free memory -ENOMEM is returned, otherwise zero
1644 * is returned and the old skb data released.
1646 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1648 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1649 __skb_linearize(skb
) : 0;
1653 * skb_postpull_rcsum - update checksum for received skb after pull
1654 * @skb: buffer to update
1655 * @start: start of data before pull
1656 * @len: length of data pulled
1658 * After doing a pull on a received packet, you need to call this to
1659 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1660 * CHECKSUM_NONE so that it can be recomputed from scratch.
1663 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1664 const void *start
, unsigned int len
)
1666 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1667 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1670 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1673 * pskb_trim_rcsum - trim received skb and update checksum
1674 * @skb: buffer to trim
1677 * This is exactly the same as pskb_trim except that it ensures the
1678 * checksum of received packets are still valid after the operation.
1681 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1683 if (likely(len
>= skb
->len
))
1685 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1686 skb
->ip_summed
= CHECKSUM_NONE
;
1687 return __pskb_trim(skb
, len
);
1690 #define skb_queue_walk(queue, skb) \
1691 for (skb = (queue)->next; \
1692 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1695 #define skb_queue_walk_safe(queue, skb, tmp) \
1696 for (skb = (queue)->next, tmp = skb->next; \
1697 skb != (struct sk_buff *)(queue); \
1698 skb = tmp, tmp = skb->next)
1700 #define skb_queue_walk_from(queue, skb) \
1701 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1704 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1705 for (tmp = skb->next; \
1706 skb != (struct sk_buff *)(queue); \
1707 skb = tmp, tmp = skb->next)
1709 #define skb_queue_reverse_walk(queue, skb) \
1710 for (skb = (queue)->prev; \
1711 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1715 static inline bool skb_has_frags(const struct sk_buff
*skb
)
1717 return skb_shinfo(skb
)->frag_list
!= NULL
;
1720 static inline void skb_frag_list_init(struct sk_buff
*skb
)
1722 skb_shinfo(skb
)->frag_list
= NULL
;
1725 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
1727 frag
->next
= skb_shinfo(skb
)->frag_list
;
1728 skb_shinfo(skb
)->frag_list
= frag
;
1731 #define skb_walk_frags(skb, iter) \
1732 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
1734 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1735 int *peeked
, int *err
);
1736 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1737 int noblock
, int *err
);
1738 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1739 struct poll_table_struct
*wait
);
1740 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1741 int offset
, struct iovec
*to
,
1743 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1746 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1748 const struct iovec
*from
,
1751 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
1753 const struct iovec
*to
,
1756 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1757 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1758 unsigned int flags
);
1759 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1760 int len
, __wsum csum
);
1761 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1763 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1764 const void *from
, int len
);
1765 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1766 int offset
, u8
*to
, int len
,
1768 extern int skb_splice_bits(struct sk_buff
*skb
,
1769 unsigned int offset
,
1770 struct pipe_inode_info
*pipe
,
1772 unsigned int flags
);
1773 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1774 extern void skb_split(struct sk_buff
*skb
,
1775 struct sk_buff
*skb1
, const u32 len
);
1776 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1779 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1781 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1782 int len
, void *buffer
)
1784 int hlen
= skb_headlen(skb
);
1786 if (hlen
- offset
>= len
)
1787 return skb
->data
+ offset
;
1789 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1795 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1797 const unsigned int len
)
1799 memcpy(to
, skb
->data
, len
);
1802 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1803 const int offset
, void *to
,
1804 const unsigned int len
)
1806 memcpy(to
, skb
->data
+ offset
, len
);
1809 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1811 const unsigned int len
)
1813 memcpy(skb
->data
, from
, len
);
1816 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1819 const unsigned int len
)
1821 memcpy(skb
->data
+ offset
, from
, len
);
1824 extern void skb_init(void);
1826 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
1832 * skb_get_timestamp - get timestamp from a skb
1833 * @skb: skb to get stamp from
1834 * @stamp: pointer to struct timeval to store stamp in
1836 * Timestamps are stored in the skb as offsets to a base timestamp.
1837 * This function converts the offset back to a struct timeval and stores
1840 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
1841 struct timeval
*stamp
)
1843 *stamp
= ktime_to_timeval(skb
->tstamp
);
1846 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
1847 struct timespec
*stamp
)
1849 *stamp
= ktime_to_timespec(skb
->tstamp
);
1852 static inline void __net_timestamp(struct sk_buff
*skb
)
1854 skb
->tstamp
= ktime_get_real();
1857 static inline ktime_t
net_timedelta(ktime_t t
)
1859 return ktime_sub(ktime_get_real(), t
);
1862 static inline ktime_t
net_invalid_timestamp(void)
1864 return ktime_set(0, 0);
1868 * skb_tstamp_tx - queue clone of skb with send time stamps
1869 * @orig_skb: the original outgoing packet
1870 * @hwtstamps: hardware time stamps, may be NULL if not available
1872 * If the skb has a socket associated, then this function clones the
1873 * skb (thus sharing the actual data and optional structures), stores
1874 * the optional hardware time stamping information (if non NULL) or
1875 * generates a software time stamp (otherwise), then queues the clone
1876 * to the error queue of the socket. Errors are silently ignored.
1878 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
1879 struct skb_shared_hwtstamps
*hwtstamps
);
1881 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1882 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1884 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1886 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1890 * skb_checksum_complete - Calculate checksum of an entire packet
1891 * @skb: packet to process
1893 * This function calculates the checksum over the entire packet plus
1894 * the value of skb->csum. The latter can be used to supply the
1895 * checksum of a pseudo header as used by TCP/UDP. It returns the
1898 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1899 * this function can be used to verify that checksum on received
1900 * packets. In that case the function should return zero if the
1901 * checksum is correct. In particular, this function will return zero
1902 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1903 * hardware has already verified the correctness of the checksum.
1905 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1907 return skb_csum_unnecessary(skb
) ?
1908 0 : __skb_checksum_complete(skb
);
1911 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1912 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1913 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1915 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1916 nf_conntrack_destroy(nfct
);
1918 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1921 atomic_inc(&nfct
->use
);
1923 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1926 atomic_inc(&skb
->users
);
1928 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1934 #ifdef CONFIG_BRIDGE_NETFILTER
1935 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1937 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1940 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1943 atomic_inc(&nf_bridge
->use
);
1945 #endif /* CONFIG_BRIDGE_NETFILTER */
1946 static inline void nf_reset(struct sk_buff
*skb
)
1948 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1949 nf_conntrack_put(skb
->nfct
);
1951 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1952 skb
->nfct_reasm
= NULL
;
1954 #ifdef CONFIG_BRIDGE_NETFILTER
1955 nf_bridge_put(skb
->nf_bridge
);
1956 skb
->nf_bridge
= NULL
;
1960 /* Note: This doesn't put any conntrack and bridge info in dst. */
1961 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1963 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1964 dst
->nfct
= src
->nfct
;
1965 nf_conntrack_get(src
->nfct
);
1966 dst
->nfctinfo
= src
->nfctinfo
;
1967 dst
->nfct_reasm
= src
->nfct_reasm
;
1968 nf_conntrack_get_reasm(src
->nfct_reasm
);
1970 #ifdef CONFIG_BRIDGE_NETFILTER
1971 dst
->nf_bridge
= src
->nf_bridge
;
1972 nf_bridge_get(src
->nf_bridge
);
1976 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1978 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1979 nf_conntrack_put(dst
->nfct
);
1980 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1982 #ifdef CONFIG_BRIDGE_NETFILTER
1983 nf_bridge_put(dst
->nf_bridge
);
1985 __nf_copy(dst
, src
);
1988 #ifdef CONFIG_NETWORK_SECMARK
1989 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1991 to
->secmark
= from
->secmark
;
1994 static inline void skb_init_secmark(struct sk_buff
*skb
)
1999 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2002 static inline void skb_init_secmark(struct sk_buff
*skb
)
2006 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2008 skb
->queue_mapping
= queue_mapping
;
2011 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2013 return skb
->queue_mapping
;
2016 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2018 to
->queue_mapping
= from
->queue_mapping
;
2021 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2023 skb
->queue_mapping
= rx_queue
+ 1;
2026 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2028 return skb
->queue_mapping
- 1;
2031 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2033 return (skb
->queue_mapping
!= 0);
2036 extern u16
skb_tx_hash(const struct net_device
*dev
,
2037 const struct sk_buff
*skb
);
2040 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2045 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2051 static inline int skb_is_gso(const struct sk_buff
*skb
)
2053 return skb_shinfo(skb
)->gso_size
;
2056 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
2058 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2061 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2063 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2065 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2066 * wanted then gso_type will be set. */
2067 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2068 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
2069 __skb_warn_lro_forwarding(skb
);
2075 static inline void skb_forward_csum(struct sk_buff
*skb
)
2077 /* Unfortunately we don't support this one. Any brave souls? */
2078 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2079 skb
->ip_summed
= CHECKSUM_NONE
;
2082 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2083 #endif /* __KERNEL__ */
2084 #endif /* _LINUX_SKBUFF_H */