2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
24 #include <linux/atomic.h>
25 #include <asm/types.h>
26 #include <linux/spinlock.h>
27 #include <linux/net.h>
28 #include <linux/textsearch.h>
29 #include <net/checksum.h>
30 #include <linux/rcupdate.h>
31 #include <linux/dmaengine.h>
32 #include <linux/hrtimer.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/netdev_features.h>
36 /* Don't change this without changing skb_csum_unnecessary! */
37 #define CHECKSUM_NONE 0
38 #define CHECKSUM_UNNECESSARY 1
39 #define CHECKSUM_COMPLETE 2
40 #define CHECKSUM_PARTIAL 3
42 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
43 ~(SMP_CACHE_BYTES - 1))
44 #define SKB_WITH_OVERHEAD(X) \
45 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
46 #define SKB_MAX_ORDER(X, ORDER) \
47 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
48 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
49 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
51 /* return minimum truesize of one skb containing X bytes of data */
52 #define SKB_TRUESIZE(X) ((X) + \
53 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
54 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
56 /* A. Checksumming of received packets by device.
58 * NONE: device failed to checksum this packet.
59 * skb->csum is undefined.
61 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
62 * skb->csum is undefined.
63 * It is bad option, but, unfortunately, many of vendors do this.
64 * Apparently with secret goal to sell you new device, when you
65 * will add new protocol to your host. F.e. IPv6. 8)
67 * COMPLETE: the most generic way. Device supplied checksum of _all_
68 * the packet as seen by netif_rx in skb->csum.
69 * NOTE: Even if device supports only some protocols, but
70 * is able to produce some skb->csum, it MUST use COMPLETE,
73 * PARTIAL: identical to the case for output below. This may occur
74 * on a packet received directly from another Linux OS, e.g.,
75 * a virtualised Linux kernel on the same host. The packet can
76 * be treated in the same way as UNNECESSARY except that on
77 * output (i.e., forwarding) the checksum must be filled in
78 * by the OS or the hardware.
80 * B. Checksumming on output.
82 * NONE: skb is checksummed by protocol or csum is not required.
84 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
85 * from skb->csum_start to the end and to record the checksum
86 * at skb->csum_start + skb->csum_offset.
88 * Device must show its capabilities in dev->features, set
89 * at device setup time.
90 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
92 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
93 * TCP/UDP over IPv4. Sigh. Vendors like this
94 * way by an unknown reason. Though, see comment above
95 * about CHECKSUM_UNNECESSARY. 8)
96 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
98 * UNNECESSARY: device will do per protocol specific csum. Protocol drivers
99 * that do not want net to perform the checksum calculation should use
100 * this flag in their outgoing skbs.
101 * NETIF_F_FCOE_CRC this indicates the device can do FCoE FC CRC
102 * offload. Correspondingly, the FCoE protocol driver
103 * stack should use CHECKSUM_UNNECESSARY.
105 * Any questions? No questions, good. --ANK
110 struct pipe_inode_info
;
112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
113 struct nf_conntrack
{
118 #ifdef CONFIG_BRIDGE_NETFILTER
119 struct nf_bridge_info
{
122 struct net_device
*physindev
;
123 struct net_device
*physoutdev
;
124 unsigned long data
[32 / sizeof(unsigned long)];
128 struct sk_buff_head
{
129 /* These two members must be first. */
130 struct sk_buff
*next
;
131 struct sk_buff
*prev
;
139 /* To allow 64K frame to be packed as single skb without frag_list we
140 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
141 * buffers which do not start on a page boundary.
143 * Since GRO uses frags we allocate at least 16 regardless of page
146 #if (65536/PAGE_SIZE + 1) < 16
147 #define MAX_SKB_FRAGS 16UL
149 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
152 typedef struct skb_frag_struct skb_frag_t
;
154 struct skb_frag_struct
{
158 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
167 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
172 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
177 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
182 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
187 #define HAVE_HW_TIME_STAMP
190 * struct skb_shared_hwtstamps - hardware time stamps
191 * @hwtstamp: hardware time stamp transformed into duration
192 * since arbitrary point in time
193 * @syststamp: hwtstamp transformed to system time base
195 * Software time stamps generated by ktime_get_real() are stored in
196 * skb->tstamp. The relation between the different kinds of time
197 * stamps is as follows:
199 * syststamp and tstamp can be compared against each other in
200 * arbitrary combinations. The accuracy of a
201 * syststamp/tstamp/"syststamp from other device" comparison is
202 * limited by the accuracy of the transformation into system time
203 * base. This depends on the device driver and its underlying
206 * hwtstamps can only be compared against other hwtstamps from
209 * This structure is attached to packets as part of the
210 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
212 struct skb_shared_hwtstamps
{
217 /* Definitions for tx_flags in struct skb_shared_info */
219 /* generate hardware time stamp */
220 SKBTX_HW_TSTAMP
= 1 << 0,
222 /* generate software time stamp */
223 SKBTX_SW_TSTAMP
= 1 << 1,
225 /* device driver is going to provide hardware time stamp */
226 SKBTX_IN_PROGRESS
= 1 << 2,
228 /* device driver supports TX zero-copy buffers */
229 SKBTX_DEV_ZEROCOPY
= 1 << 3,
231 /* generate wifi status information (where possible) */
232 SKBTX_WIFI_STATUS
= 1 << 4,
236 * The callback notifies userspace to release buffers when skb DMA is done in
237 * lower device, the skb last reference should be 0 when calling this.
238 * The zerocopy_success argument is true if zero copy transmit occurred,
239 * false on data copy or out of memory error caused by data copy attempt.
240 * The ctx field is used to track device context.
241 * The desc field is used to track userspace buffer index.
244 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
249 /* This data is invariant across clones and lives at
250 * the end of the header data, ie. at skb->end.
252 struct skb_shared_info
{
253 unsigned char nr_frags
;
255 unsigned short gso_size
;
256 /* Warning: this field is not always filled in (UFO)! */
257 unsigned short gso_segs
;
258 unsigned short gso_type
;
259 struct sk_buff
*frag_list
;
260 struct skb_shared_hwtstamps hwtstamps
;
264 * Warning : all fields before dataref are cleared in __alloc_skb()
268 /* Intermediate layers must ensure that destructor_arg
269 * remains valid until skb destructor */
270 void * destructor_arg
;
272 /* must be last field, see pskb_expand_head() */
273 skb_frag_t frags
[MAX_SKB_FRAGS
];
276 /* We divide dataref into two halves. The higher 16 bits hold references
277 * to the payload part of skb->data. The lower 16 bits hold references to
278 * the entire skb->data. A clone of a headerless skb holds the length of
279 * the header in skb->hdr_len.
281 * All users must obey the rule that the skb->data reference count must be
282 * greater than or equal to the payload reference count.
284 * Holding a reference to the payload part means that the user does not
285 * care about modifications to the header part of skb->data.
287 #define SKB_DATAREF_SHIFT 16
288 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
292 SKB_FCLONE_UNAVAILABLE
,
298 SKB_GSO_TCPV4
= 1 << 0,
299 SKB_GSO_UDP
= 1 << 1,
301 /* This indicates the skb is from an untrusted source. */
302 SKB_GSO_DODGY
= 1 << 2,
304 /* This indicates the tcp segment has CWR set. */
305 SKB_GSO_TCP_ECN
= 1 << 3,
307 SKB_GSO_TCPV6
= 1 << 4,
309 SKB_GSO_FCOE
= 1 << 5,
312 #if BITS_PER_LONG > 32
313 #define NET_SKBUFF_DATA_USES_OFFSET 1
316 #ifdef NET_SKBUFF_DATA_USES_OFFSET
317 typedef unsigned int sk_buff_data_t
;
319 typedef unsigned char *sk_buff_data_t
;
322 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
323 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
324 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
328 * struct sk_buff - socket buffer
329 * @next: Next buffer in list
330 * @prev: Previous buffer in list
331 * @tstamp: Time we arrived
332 * @sk: Socket we are owned by
333 * @dev: Device we arrived on/are leaving by
334 * @cb: Control buffer. Free for use by every layer. Put private vars here
335 * @_skb_refdst: destination entry (with norefcount bit)
336 * @sp: the security path, used for xfrm
337 * @len: Length of actual data
338 * @data_len: Data length
339 * @mac_len: Length of link layer header
340 * @hdr_len: writable header length of cloned skb
341 * @csum: Checksum (must include start/offset pair)
342 * @csum_start: Offset from skb->head where checksumming should start
343 * @csum_offset: Offset from csum_start where checksum should be stored
344 * @priority: Packet queueing priority
345 * @local_df: allow local fragmentation
346 * @cloned: Head may be cloned (check refcnt to be sure)
347 * @ip_summed: Driver fed us an IP checksum
348 * @nohdr: Payload reference only, must not modify header
349 * @nfctinfo: Relationship of this skb to the connection
350 * @pkt_type: Packet class
351 * @fclone: skbuff clone status
352 * @ipvs_property: skbuff is owned by ipvs
353 * @peeked: this packet has been seen already, so stats have been
354 * done for it, don't do them again
355 * @nf_trace: netfilter packet trace flag
356 * @protocol: Packet protocol from driver
357 * @destructor: Destruct function
358 * @nfct: Associated connection, if any
359 * @nfct_reasm: netfilter conntrack re-assembly pointer
360 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
361 * @skb_iif: ifindex of device we arrived on
362 * @tc_index: Traffic control index
363 * @tc_verd: traffic control verdict
364 * @rxhash: the packet hash computed on receive
365 * @queue_mapping: Queue mapping for multiqueue devices
366 * @ndisc_nodetype: router type (from link layer)
367 * @ooo_okay: allow the mapping of a socket to a queue to be changed
368 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
370 * @wifi_acked_valid: wifi_acked was set
371 * @wifi_acked: whether frame was acked on wifi or not
372 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
373 * @dma_cookie: a cookie to one of several possible DMA operations
374 * done by skb DMA functions
375 * @secmark: security marking
376 * @mark: Generic packet mark
377 * @dropcount: total number of sk_receive_queue overflows
378 * @vlan_tci: vlan tag control information
379 * @inner_transport_header: Inner transport layer header (encapsulation)
380 * @inner_network_header: Network layer header (encapsulation)
381 * @transport_header: Transport layer header
382 * @network_header: Network layer header
383 * @mac_header: Link layer header
384 * @tail: Tail pointer
386 * @head: Head of buffer
387 * @data: Data head pointer
388 * @truesize: Buffer size
389 * @users: User count - see {datagram,tcp}.c
393 /* These two members must be first. */
394 struct sk_buff
*next
;
395 struct sk_buff
*prev
;
400 struct net_device
*dev
;
403 * This is the control buffer. It is free to use for every
404 * layer. Please put your private variables there. If you
405 * want to keep them across layers you have to do a skb_clone()
406 * first. This is owned by whoever has the skb queued ATM.
408 char cb
[48] __aligned(8);
410 unsigned long _skb_refdst
;
426 kmemcheck_bitfield_begin(flags1
);
437 kmemcheck_bitfield_end(flags1
);
440 void (*destructor
)(struct sk_buff
*skb
);
441 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
442 struct nf_conntrack
*nfct
;
444 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
445 struct sk_buff
*nfct_reasm
;
447 #ifdef CONFIG_BRIDGE_NETFILTER
448 struct nf_bridge_info
*nf_bridge
;
457 #ifdef CONFIG_NET_SCHED
458 __u16 tc_index
; /* traffic control index */
459 #ifdef CONFIG_NET_CLS_ACT
460 __u16 tc_verd
; /* traffic control verdict */
465 kmemcheck_bitfield_begin(flags2
);
466 #ifdef CONFIG_IPV6_NDISC_NODETYPE
467 __u8 ndisc_nodetype
:2;
472 __u8 wifi_acked_valid
:1;
476 /* Encapsulation protocol and NIC drivers should use
477 * this flag to indicate to each other if the skb contains
478 * encapsulated packet or not and maybe use the inner packet
481 __u8 encapsulation
:1;
482 /* 7/9 bit hole (depending on ndisc_nodetype presence) */
483 kmemcheck_bitfield_end(flags2
);
485 #ifdef CONFIG_NET_DMA
486 dma_cookie_t dma_cookie
;
488 #ifdef CONFIG_NETWORK_SECMARK
497 sk_buff_data_t inner_transport_header
;
498 sk_buff_data_t inner_network_header
;
499 sk_buff_data_t transport_header
;
500 sk_buff_data_t network_header
;
501 sk_buff_data_t mac_header
;
502 /* These elements must be at the end, see alloc_skb() for details. */
507 unsigned int truesize
;
513 * Handling routines are only of interest to the kernel
515 #include <linux/slab.h>
518 #define SKB_ALLOC_FCLONE 0x01
519 #define SKB_ALLOC_RX 0x02
521 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
522 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
524 return unlikely(skb
->pfmemalloc
);
528 * skb might have a dst pointer attached, refcounted or not.
529 * _skb_refdst low order bit is set if refcount was _not_ taken
531 #define SKB_DST_NOREF 1UL
532 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
535 * skb_dst - returns skb dst_entry
538 * Returns skb dst_entry, regardless of reference taken or not.
540 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
542 /* If refdst was not refcounted, check we still are in a
543 * rcu_read_lock section
545 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
546 !rcu_read_lock_held() &&
547 !rcu_read_lock_bh_held());
548 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
552 * skb_dst_set - sets skb dst
556 * Sets skb dst, assuming a reference was taken on dst and should
557 * be released by skb_dst_drop()
559 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
561 skb
->_skb_refdst
= (unsigned long)dst
;
564 extern void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
);
567 * skb_dst_is_noref - Test if skb dst isn't refcounted
570 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
572 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
575 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
577 return (struct rtable
*)skb_dst(skb
);
580 extern void kfree_skb(struct sk_buff
*skb
);
581 extern void skb_tx_error(struct sk_buff
*skb
);
582 extern void consume_skb(struct sk_buff
*skb
);
583 extern void __kfree_skb(struct sk_buff
*skb
);
584 extern struct kmem_cache
*skbuff_head_cache
;
586 extern void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
587 extern bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
588 bool *fragstolen
, int *delta_truesize
);
590 extern struct sk_buff
*__alloc_skb(unsigned int size
,
591 gfp_t priority
, int flags
, int node
);
592 extern struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
593 static inline struct sk_buff
*alloc_skb(unsigned int size
,
596 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
599 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
602 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
605 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
606 extern int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
607 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
609 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
611 extern struct sk_buff
*__pskb_copy(struct sk_buff
*skb
,
612 int headroom
, gfp_t gfp_mask
);
614 extern int pskb_expand_head(struct sk_buff
*skb
,
615 int nhead
, int ntail
,
617 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
618 unsigned int headroom
);
619 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
620 int newheadroom
, int newtailroom
,
622 extern int skb_to_sgvec(struct sk_buff
*skb
,
623 struct scatterlist
*sg
, int offset
,
625 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
626 struct sk_buff
**trailer
);
627 extern int skb_pad(struct sk_buff
*skb
, int pad
);
628 #define dev_kfree_skb(a) consume_skb(a)
630 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
631 int getfrag(void *from
, char *to
, int offset
,
632 int len
,int odd
, struct sk_buff
*skb
),
633 void *from
, int length
);
635 struct skb_seq_state
{
639 __u32 stepped_offset
;
640 struct sk_buff
*root_skb
;
641 struct sk_buff
*cur_skb
;
645 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
646 unsigned int from
, unsigned int to
,
647 struct skb_seq_state
*st
);
648 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
649 struct skb_seq_state
*st
);
650 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
652 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
653 unsigned int to
, struct ts_config
*config
,
654 struct ts_state
*state
);
656 extern void __skb_get_rxhash(struct sk_buff
*skb
);
657 static inline __u32
skb_get_rxhash(struct sk_buff
*skb
)
660 __skb_get_rxhash(skb
);
665 #ifdef NET_SKBUFF_DATA_USES_OFFSET
666 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
668 return skb
->head
+ skb
->end
;
671 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
676 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
681 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
683 return skb
->end
- skb
->head
;
688 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
690 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
692 return &skb_shinfo(skb
)->hwtstamps
;
696 * skb_queue_empty - check if a queue is empty
699 * Returns true if the queue is empty, false otherwise.
701 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
703 return list
->next
== (struct sk_buff
*)list
;
707 * skb_queue_is_last - check if skb is the last entry in the queue
711 * Returns true if @skb is the last buffer on the list.
713 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
714 const struct sk_buff
*skb
)
716 return skb
->next
== (struct sk_buff
*)list
;
720 * skb_queue_is_first - check if skb is the first entry in the queue
724 * Returns true if @skb is the first buffer on the list.
726 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
727 const struct sk_buff
*skb
)
729 return skb
->prev
== (struct sk_buff
*)list
;
733 * skb_queue_next - return the next packet in the queue
735 * @skb: current buffer
737 * Return the next packet in @list after @skb. It is only valid to
738 * call this if skb_queue_is_last() evaluates to false.
740 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
741 const struct sk_buff
*skb
)
743 /* This BUG_ON may seem severe, but if we just return then we
744 * are going to dereference garbage.
746 BUG_ON(skb_queue_is_last(list
, skb
));
751 * skb_queue_prev - return the prev packet in the queue
753 * @skb: current buffer
755 * Return the prev packet in @list before @skb. It is only valid to
756 * call this if skb_queue_is_first() evaluates to false.
758 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
759 const struct sk_buff
*skb
)
761 /* This BUG_ON may seem severe, but if we just return then we
762 * are going to dereference garbage.
764 BUG_ON(skb_queue_is_first(list
, skb
));
769 * skb_get - reference buffer
770 * @skb: buffer to reference
772 * Makes another reference to a socket buffer and returns a pointer
775 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
777 atomic_inc(&skb
->users
);
782 * If users == 1, we are the only owner and are can avoid redundant
787 * skb_cloned - is the buffer a clone
788 * @skb: buffer to check
790 * Returns true if the buffer was generated with skb_clone() and is
791 * one of multiple shared copies of the buffer. Cloned buffers are
792 * shared data so must not be written to under normal circumstances.
794 static inline int skb_cloned(const struct sk_buff
*skb
)
796 return skb
->cloned
&&
797 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
801 * skb_header_cloned - is the header a clone
802 * @skb: buffer to check
804 * Returns true if modifying the header part of the buffer requires
805 * the data to be copied.
807 static inline int skb_header_cloned(const struct sk_buff
*skb
)
814 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
815 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
820 * skb_header_release - release reference to header
821 * @skb: buffer to operate on
823 * Drop a reference to the header part of the buffer. This is done
824 * by acquiring a payload reference. You must not read from the header
825 * part of skb->data after this.
827 static inline void skb_header_release(struct sk_buff
*skb
)
831 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
835 * skb_shared - is the buffer shared
836 * @skb: buffer to check
838 * Returns true if more than one person has a reference to this
841 static inline int skb_shared(const struct sk_buff
*skb
)
843 return atomic_read(&skb
->users
) != 1;
847 * skb_share_check - check if buffer is shared and if so clone it
848 * @skb: buffer to check
849 * @pri: priority for memory allocation
851 * If the buffer is shared the buffer is cloned and the old copy
852 * drops a reference. A new clone with a single reference is returned.
853 * If the buffer is not shared the original buffer is returned. When
854 * being called from interrupt status or with spinlocks held pri must
857 * NULL is returned on a memory allocation failure.
859 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
861 might_sleep_if(pri
& __GFP_WAIT
);
862 if (skb_shared(skb
)) {
863 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
875 * Copy shared buffers into a new sk_buff. We effectively do COW on
876 * packets to handle cases where we have a local reader and forward
877 * and a couple of other messy ones. The normal one is tcpdumping
878 * a packet thats being forwarded.
882 * skb_unshare - make a copy of a shared buffer
883 * @skb: buffer to check
884 * @pri: priority for memory allocation
886 * If the socket buffer is a clone then this function creates a new
887 * copy of the data, drops a reference count on the old copy and returns
888 * the new copy with the reference count at 1. If the buffer is not a clone
889 * the original buffer is returned. When called with a spinlock held or
890 * from interrupt state @pri must be %GFP_ATOMIC
892 * %NULL is returned on a memory allocation failure.
894 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
897 might_sleep_if(pri
& __GFP_WAIT
);
898 if (skb_cloned(skb
)) {
899 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
900 kfree_skb(skb
); /* Free our shared copy */
907 * skb_peek - peek at the head of an &sk_buff_head
908 * @list_: list to peek at
910 * Peek an &sk_buff. Unlike most other operations you _MUST_
911 * be careful with this one. A peek leaves the buffer on the
912 * list and someone else may run off with it. You must hold
913 * the appropriate locks or have a private queue to do this.
915 * Returns %NULL for an empty list or a pointer to the head element.
916 * The reference count is not incremented and the reference is therefore
917 * volatile. Use with caution.
919 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
921 struct sk_buff
*skb
= list_
->next
;
923 if (skb
== (struct sk_buff
*)list_
)
929 * skb_peek_next - peek skb following the given one from a queue
930 * @skb: skb to start from
931 * @list_: list to peek at
933 * Returns %NULL when the end of the list is met or a pointer to the
934 * next element. The reference count is not incremented and the
935 * reference is therefore volatile. Use with caution.
937 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
938 const struct sk_buff_head
*list_
)
940 struct sk_buff
*next
= skb
->next
;
942 if (next
== (struct sk_buff
*)list_
)
948 * skb_peek_tail - peek at the tail of an &sk_buff_head
949 * @list_: list to peek at
951 * Peek an &sk_buff. Unlike most other operations you _MUST_
952 * be careful with this one. A peek leaves the buffer on the
953 * list and someone else may run off with it. You must hold
954 * the appropriate locks or have a private queue to do this.
956 * Returns %NULL for an empty list or a pointer to the tail element.
957 * The reference count is not incremented and the reference is therefore
958 * volatile. Use with caution.
960 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
962 struct sk_buff
*skb
= list_
->prev
;
964 if (skb
== (struct sk_buff
*)list_
)
971 * skb_queue_len - get queue length
972 * @list_: list to measure
974 * Return the length of an &sk_buff queue.
976 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
982 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
983 * @list: queue to initialize
985 * This initializes only the list and queue length aspects of
986 * an sk_buff_head object. This allows to initialize the list
987 * aspects of an sk_buff_head without reinitializing things like
988 * the spinlock. It can also be used for on-stack sk_buff_head
989 * objects where the spinlock is known to not be used.
991 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
993 list
->prev
= list
->next
= (struct sk_buff
*)list
;
998 * This function creates a split out lock class for each invocation;
999 * this is needed for now since a whole lot of users of the skb-queue
1000 * infrastructure in drivers have different locking usage (in hardirq)
1001 * than the networking core (in softirq only). In the long run either the
1002 * network layer or drivers should need annotation to consolidate the
1003 * main types of usage into 3 classes.
1005 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1007 spin_lock_init(&list
->lock
);
1008 __skb_queue_head_init(list
);
1011 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1012 struct lock_class_key
*class)
1014 skb_queue_head_init(list
);
1015 lockdep_set_class(&list
->lock
, class);
1019 * Insert an sk_buff on a list.
1021 * The "__skb_xxxx()" functions are the non-atomic ones that
1022 * can only be called with interrupts disabled.
1024 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
1025 static inline void __skb_insert(struct sk_buff
*newsk
,
1026 struct sk_buff
*prev
, struct sk_buff
*next
,
1027 struct sk_buff_head
*list
)
1031 next
->prev
= prev
->next
= newsk
;
1035 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1036 struct sk_buff
*prev
,
1037 struct sk_buff
*next
)
1039 struct sk_buff
*first
= list
->next
;
1040 struct sk_buff
*last
= list
->prev
;
1050 * skb_queue_splice - join two skb lists, this is designed for stacks
1051 * @list: the new list to add
1052 * @head: the place to add it in the first list
1054 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1055 struct sk_buff_head
*head
)
1057 if (!skb_queue_empty(list
)) {
1058 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1059 head
->qlen
+= list
->qlen
;
1064 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1065 * @list: the new list to add
1066 * @head: the place to add it in the first list
1068 * The list at @list is reinitialised
1070 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1071 struct sk_buff_head
*head
)
1073 if (!skb_queue_empty(list
)) {
1074 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1075 head
->qlen
+= list
->qlen
;
1076 __skb_queue_head_init(list
);
1081 * skb_queue_splice_tail - join two skb lists, each list being a queue
1082 * @list: the new list to add
1083 * @head: the place to add it in the first list
1085 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1086 struct sk_buff_head
*head
)
1088 if (!skb_queue_empty(list
)) {
1089 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1090 head
->qlen
+= list
->qlen
;
1095 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1096 * @list: the new list to add
1097 * @head: the place to add it in the first list
1099 * Each of the lists is a queue.
1100 * The list at @list is reinitialised
1102 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1103 struct sk_buff_head
*head
)
1105 if (!skb_queue_empty(list
)) {
1106 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1107 head
->qlen
+= list
->qlen
;
1108 __skb_queue_head_init(list
);
1113 * __skb_queue_after - queue a buffer at the list head
1114 * @list: list to use
1115 * @prev: place after this buffer
1116 * @newsk: buffer to queue
1118 * Queue a buffer int the middle of a list. This function takes no locks
1119 * and you must therefore hold required locks before calling it.
1121 * A buffer cannot be placed on two lists at the same time.
1123 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1124 struct sk_buff
*prev
,
1125 struct sk_buff
*newsk
)
1127 __skb_insert(newsk
, prev
, prev
->next
, list
);
1130 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1131 struct sk_buff_head
*list
);
1133 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1134 struct sk_buff
*next
,
1135 struct sk_buff
*newsk
)
1137 __skb_insert(newsk
, next
->prev
, next
, list
);
1141 * __skb_queue_head - queue a buffer at the list head
1142 * @list: list to use
1143 * @newsk: buffer to queue
1145 * Queue a buffer at the start of a list. This function takes no locks
1146 * and you must therefore hold required locks before calling it.
1148 * A buffer cannot be placed on two lists at the same time.
1150 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1151 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1152 struct sk_buff
*newsk
)
1154 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1158 * __skb_queue_tail - queue a buffer at the list tail
1159 * @list: list to use
1160 * @newsk: buffer to queue
1162 * Queue a buffer at the end of a list. This function takes no locks
1163 * and you must therefore hold required locks before calling it.
1165 * A buffer cannot be placed on two lists at the same time.
1167 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1168 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1169 struct sk_buff
*newsk
)
1171 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1175 * remove sk_buff from list. _Must_ be called atomically, and with
1178 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1179 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1181 struct sk_buff
*next
, *prev
;
1186 skb
->next
= skb
->prev
= NULL
;
1192 * __skb_dequeue - remove from the head of the queue
1193 * @list: list to dequeue from
1195 * Remove the head of the list. This function does not take any locks
1196 * so must be used with appropriate locks held only. The head item is
1197 * returned or %NULL if the list is empty.
1199 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1200 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1202 struct sk_buff
*skb
= skb_peek(list
);
1204 __skb_unlink(skb
, list
);
1209 * __skb_dequeue_tail - remove from the tail of the queue
1210 * @list: list to dequeue from
1212 * Remove the tail of the list. This function does not take any locks
1213 * so must be used with appropriate locks held only. The tail item is
1214 * returned or %NULL if the list is empty.
1216 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1217 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1219 struct sk_buff
*skb
= skb_peek_tail(list
);
1221 __skb_unlink(skb
, list
);
1226 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1228 return skb
->data_len
;
1231 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1233 return skb
->len
- skb
->data_len
;
1236 static inline int skb_pagelen(const struct sk_buff
*skb
)
1240 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1241 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1242 return len
+ skb_headlen(skb
);
1246 * __skb_fill_page_desc - initialise a paged fragment in an skb
1247 * @skb: buffer containing fragment to be initialised
1248 * @i: paged fragment index to initialise
1249 * @page: the page to use for this fragment
1250 * @off: the offset to the data with @page
1251 * @size: the length of the data
1253 * Initialises the @i'th fragment of @skb to point to &size bytes at
1254 * offset @off within @page.
1256 * Does not take any additional reference on the fragment.
1258 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1259 struct page
*page
, int off
, int size
)
1261 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1264 * Propagate page->pfmemalloc to the skb if we can. The problem is
1265 * that not all callers have unique ownership of the page. If
1266 * pfmemalloc is set, we check the mapping as a mapping implies
1267 * page->index is set (index and pfmemalloc share space).
1268 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1269 * do not lose pfmemalloc information as the pages would not be
1270 * allocated using __GFP_MEMALLOC.
1272 if (page
->pfmemalloc
&& !page
->mapping
)
1273 skb
->pfmemalloc
= true;
1274 frag
->page
.p
= page
;
1275 frag
->page_offset
= off
;
1276 skb_frag_size_set(frag
, size
);
1280 * skb_fill_page_desc - initialise a paged fragment in an skb
1281 * @skb: buffer containing fragment to be initialised
1282 * @i: paged fragment index to initialise
1283 * @page: the page to use for this fragment
1284 * @off: the offset to the data with @page
1285 * @size: the length of the data
1287 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1288 * @skb to point to &size bytes at offset @off within @page. In
1289 * addition updates @skb such that @i is the last fragment.
1291 * Does not take any additional reference on the fragment.
1293 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1294 struct page
*page
, int off
, int size
)
1296 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1297 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1300 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1301 int off
, int size
, unsigned int truesize
);
1303 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1304 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1305 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1307 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1308 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1310 return skb
->head
+ skb
->tail
;
1313 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1315 skb
->tail
= skb
->data
- skb
->head
;
1318 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1320 skb_reset_tail_pointer(skb
);
1321 skb
->tail
+= offset
;
1323 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1324 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1329 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1331 skb
->tail
= skb
->data
;
1334 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1336 skb
->tail
= skb
->data
+ offset
;
1339 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1342 * Add data to an sk_buff
1344 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1345 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1347 unsigned char *tmp
= skb_tail_pointer(skb
);
1348 SKB_LINEAR_ASSERT(skb
);
1354 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1355 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1362 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1363 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1366 BUG_ON(skb
->len
< skb
->data_len
);
1367 return skb
->data
+= len
;
1370 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1372 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1375 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1377 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1379 if (len
> skb_headlen(skb
) &&
1380 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1383 return skb
->data
+= len
;
1386 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1388 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1391 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1393 if (likely(len
<= skb_headlen(skb
)))
1395 if (unlikely(len
> skb
->len
))
1397 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1401 * skb_headroom - bytes at buffer head
1402 * @skb: buffer to check
1404 * Return the number of bytes of free space at the head of an &sk_buff.
1406 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1408 return skb
->data
- skb
->head
;
1412 * skb_tailroom - bytes at buffer end
1413 * @skb: buffer to check
1415 * Return the number of bytes of free space at the tail of an sk_buff
1417 static inline int skb_tailroom(const struct sk_buff
*skb
)
1419 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1423 * skb_availroom - bytes at buffer end
1424 * @skb: buffer to check
1426 * Return the number of bytes of free space at the tail of an sk_buff
1427 * allocated by sk_stream_alloc()
1429 static inline int skb_availroom(const struct sk_buff
*skb
)
1431 return skb_is_nonlinear(skb
) ? 0 : skb
->avail_size
- skb
->len
;
1435 * skb_reserve - adjust headroom
1436 * @skb: buffer to alter
1437 * @len: bytes to move
1439 * Increase the headroom of an empty &sk_buff by reducing the tail
1440 * room. This is only allowed for an empty buffer.
1442 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1448 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1450 skb
->inner_network_header
= skb
->network_header
;
1451 skb
->inner_transport_header
= skb
->transport_header
;
1454 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1456 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1459 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1460 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1463 return skb
->head
+ skb
->inner_transport_header
;
1466 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1468 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1471 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1474 skb_reset_inner_transport_header(skb
);
1475 skb
->inner_transport_header
+= offset
;
1478 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1480 return skb
->head
+ skb
->inner_network_header
;
1483 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1485 skb
->inner_network_header
= skb
->data
- skb
->head
;
1488 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1491 skb_reset_inner_network_header(skb
);
1492 skb
->inner_network_header
+= offset
;
1495 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1497 return skb
->transport_header
!= ~0U;
1500 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1502 return skb
->head
+ skb
->transport_header
;
1505 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1507 skb
->transport_header
= skb
->data
- skb
->head
;
1510 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1513 skb_reset_transport_header(skb
);
1514 skb
->transport_header
+= offset
;
1517 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1519 return skb
->head
+ skb
->network_header
;
1522 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1524 skb
->network_header
= skb
->data
- skb
->head
;
1527 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1529 skb_reset_network_header(skb
);
1530 skb
->network_header
+= offset
;
1533 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1535 return skb
->head
+ skb
->mac_header
;
1538 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1540 return skb
->mac_header
!= ~0U;
1543 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1545 skb
->mac_header
= skb
->data
- skb
->head
;
1548 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1550 skb_reset_mac_header(skb
);
1551 skb
->mac_header
+= offset
;
1554 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1555 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1558 return skb
->inner_transport_header
;
1561 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1563 skb
->inner_transport_header
= skb
->data
;
1566 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1569 skb
->inner_transport_header
= skb
->data
+ offset
;
1572 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1574 return skb
->inner_network_header
;
1577 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1579 skb
->inner_network_header
= skb
->data
;
1582 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1585 skb
->inner_network_header
= skb
->data
+ offset
;
1588 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1590 return skb
->transport_header
!= NULL
;
1593 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1595 return skb
->transport_header
;
1598 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1600 skb
->transport_header
= skb
->data
;
1603 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1606 skb
->transport_header
= skb
->data
+ offset
;
1609 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1611 return skb
->network_header
;
1614 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1616 skb
->network_header
= skb
->data
;
1619 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1621 skb
->network_header
= skb
->data
+ offset
;
1624 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1626 return skb
->mac_header
;
1629 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1631 return skb
->mac_header
!= NULL
;
1634 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1636 skb
->mac_header
= skb
->data
;
1639 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1641 skb
->mac_header
= skb
->data
+ offset
;
1643 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1645 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1647 if (skb_mac_header_was_set(skb
)) {
1648 const unsigned char *old_mac
= skb_mac_header(skb
);
1650 skb_set_mac_header(skb
, -skb
->mac_len
);
1651 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1655 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1657 return skb
->csum_start
- skb_headroom(skb
);
1660 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1662 return skb_transport_header(skb
) - skb
->data
;
1665 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1667 return skb
->transport_header
- skb
->network_header
;
1670 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1672 return skb
->inner_transport_header
- skb
->inner_network_header
;
1675 static inline int skb_network_offset(const struct sk_buff
*skb
)
1677 return skb_network_header(skb
) - skb
->data
;
1680 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1682 return skb_inner_network_header(skb
) - skb
->data
;
1685 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1687 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1691 * CPUs often take a performance hit when accessing unaligned memory
1692 * locations. The actual performance hit varies, it can be small if the
1693 * hardware handles it or large if we have to take an exception and fix it
1696 * Since an ethernet header is 14 bytes network drivers often end up with
1697 * the IP header at an unaligned offset. The IP header can be aligned by
1698 * shifting the start of the packet by 2 bytes. Drivers should do this
1701 * skb_reserve(skb, NET_IP_ALIGN);
1703 * The downside to this alignment of the IP header is that the DMA is now
1704 * unaligned. On some architectures the cost of an unaligned DMA is high
1705 * and this cost outweighs the gains made by aligning the IP header.
1707 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1710 #ifndef NET_IP_ALIGN
1711 #define NET_IP_ALIGN 2
1715 * The networking layer reserves some headroom in skb data (via
1716 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1717 * the header has to grow. In the default case, if the header has to grow
1718 * 32 bytes or less we avoid the reallocation.
1720 * Unfortunately this headroom changes the DMA alignment of the resulting
1721 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1722 * on some architectures. An architecture can override this value,
1723 * perhaps setting it to a cacheline in size (since that will maintain
1724 * cacheline alignment of the DMA). It must be a power of 2.
1726 * Various parts of the networking layer expect at least 32 bytes of
1727 * headroom, you should not reduce this.
1729 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1730 * to reduce average number of cache lines per packet.
1731 * get_rps_cpus() for example only access one 64 bytes aligned block :
1732 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1735 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1738 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1740 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1742 if (unlikely(skb_is_nonlinear(skb
))) {
1747 skb_set_tail_pointer(skb
, len
);
1750 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1752 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1755 return ___pskb_trim(skb
, len
);
1756 __skb_trim(skb
, len
);
1760 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1762 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1766 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1767 * @skb: buffer to alter
1770 * This is identical to pskb_trim except that the caller knows that
1771 * the skb is not cloned so we should never get an error due to out-
1774 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1776 int err
= pskb_trim(skb
, len
);
1781 * skb_orphan - orphan a buffer
1782 * @skb: buffer to orphan
1784 * If a buffer currently has an owner then we call the owner's
1785 * destructor function and make the @skb unowned. The buffer continues
1786 * to exist but is no longer charged to its former owner.
1788 static inline void skb_orphan(struct sk_buff
*skb
)
1790 if (skb
->destructor
)
1791 skb
->destructor(skb
);
1792 skb
->destructor
= NULL
;
1797 * skb_orphan_frags - orphan the frags contained in a buffer
1798 * @skb: buffer to orphan frags from
1799 * @gfp_mask: allocation mask for replacement pages
1801 * For each frag in the SKB which needs a destructor (i.e. has an
1802 * owner) create a copy of that frag and release the original
1803 * page by calling the destructor.
1805 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1807 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1809 return skb_copy_ubufs(skb
, gfp_mask
);
1813 * __skb_queue_purge - empty a list
1814 * @list: list to empty
1816 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1817 * the list and one reference dropped. This function does not take the
1818 * list lock and the caller must hold the relevant locks to use it.
1820 extern void skb_queue_purge(struct sk_buff_head
*list
);
1821 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1823 struct sk_buff
*skb
;
1824 while ((skb
= __skb_dequeue(list
)) != NULL
)
1828 extern void *netdev_alloc_frag(unsigned int fragsz
);
1830 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1831 unsigned int length
,
1835 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1836 * @dev: network device to receive on
1837 * @length: length to allocate
1839 * Allocate a new &sk_buff and assign it a usage count of one. The
1840 * buffer has unspecified headroom built in. Users should allocate
1841 * the headroom they think they need without accounting for the
1842 * built in space. The built in space is used for optimisations.
1844 * %NULL is returned if there is no free memory. Although this function
1845 * allocates memory it can be called from an interrupt.
1847 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1848 unsigned int length
)
1850 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1853 /* legacy helper around __netdev_alloc_skb() */
1854 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1857 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
1860 /* legacy helper around netdev_alloc_skb() */
1861 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1863 return netdev_alloc_skb(NULL
, length
);
1867 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
1868 unsigned int length
, gfp_t gfp
)
1870 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
1872 if (NET_IP_ALIGN
&& skb
)
1873 skb_reserve(skb
, NET_IP_ALIGN
);
1877 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
1878 unsigned int length
)
1880 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
1884 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1885 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1886 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1887 * @order: size of the allocation
1889 * Allocate a new page.
1891 * %NULL is returned if there is no free memory.
1893 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
1894 struct sk_buff
*skb
,
1899 gfp_mask
|= __GFP_COLD
;
1901 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1902 gfp_mask
|= __GFP_MEMALLOC
;
1904 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
1905 if (skb
&& page
&& page
->pfmemalloc
)
1906 skb
->pfmemalloc
= true;
1912 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1913 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1914 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1916 * Allocate a new page.
1918 * %NULL is returned if there is no free memory.
1920 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
1921 struct sk_buff
*skb
)
1923 return __skb_alloc_pages(gfp_mask
, skb
, 0);
1927 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1928 * @page: The page that was allocated from skb_alloc_page
1929 * @skb: The skb that may need pfmemalloc set
1931 static inline void skb_propagate_pfmemalloc(struct page
*page
,
1932 struct sk_buff
*skb
)
1934 if (page
&& page
->pfmemalloc
)
1935 skb
->pfmemalloc
= true;
1939 * skb_frag_page - retrieve the page refered to by a paged fragment
1940 * @frag: the paged fragment
1942 * Returns the &struct page associated with @frag.
1944 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
1946 return frag
->page
.p
;
1950 * __skb_frag_ref - take an addition reference on a paged fragment.
1951 * @frag: the paged fragment
1953 * Takes an additional reference on the paged fragment @frag.
1955 static inline void __skb_frag_ref(skb_frag_t
*frag
)
1957 get_page(skb_frag_page(frag
));
1961 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1963 * @f: the fragment offset.
1965 * Takes an additional reference on the @f'th paged fragment of @skb.
1967 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
1969 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
1973 * __skb_frag_unref - release a reference on a paged fragment.
1974 * @frag: the paged fragment
1976 * Releases a reference on the paged fragment @frag.
1978 static inline void __skb_frag_unref(skb_frag_t
*frag
)
1980 put_page(skb_frag_page(frag
));
1984 * skb_frag_unref - release a reference on a paged fragment of an skb.
1986 * @f: the fragment offset
1988 * Releases a reference on the @f'th paged fragment of @skb.
1990 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
1992 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
1996 * skb_frag_address - gets the address of the data contained in a paged fragment
1997 * @frag: the paged fragment buffer
1999 * Returns the address of the data within @frag. The page must already
2002 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2004 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2008 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2009 * @frag: the paged fragment buffer
2011 * Returns the address of the data within @frag. Checks that the page
2012 * is mapped and returns %NULL otherwise.
2014 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2016 void *ptr
= page_address(skb_frag_page(frag
));
2020 return ptr
+ frag
->page_offset
;
2024 * __skb_frag_set_page - sets the page contained in a paged fragment
2025 * @frag: the paged fragment
2026 * @page: the page to set
2028 * Sets the fragment @frag to contain @page.
2030 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2032 frag
->page
.p
= page
;
2036 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2038 * @f: the fragment offset
2039 * @page: the page to set
2041 * Sets the @f'th fragment of @skb to contain @page.
2043 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2046 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2050 * skb_frag_dma_map - maps a paged fragment via the DMA API
2051 * @dev: the device to map the fragment to
2052 * @frag: the paged fragment to map
2053 * @offset: the offset within the fragment (starting at the
2054 * fragment's own offset)
2055 * @size: the number of bytes to map
2056 * @dir: the direction of the mapping (%PCI_DMA_*)
2058 * Maps the page associated with @frag to @device.
2060 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2061 const skb_frag_t
*frag
,
2062 size_t offset
, size_t size
,
2063 enum dma_data_direction dir
)
2065 return dma_map_page(dev
, skb_frag_page(frag
),
2066 frag
->page_offset
+ offset
, size
, dir
);
2069 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2072 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2076 * skb_clone_writable - is the header of a clone writable
2077 * @skb: buffer to check
2078 * @len: length up to which to write
2080 * Returns true if modifying the header part of the cloned buffer
2081 * does not requires the data to be copied.
2083 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2085 return !skb_header_cloned(skb
) &&
2086 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2089 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2094 if (headroom
> skb_headroom(skb
))
2095 delta
= headroom
- skb_headroom(skb
);
2097 if (delta
|| cloned
)
2098 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2104 * skb_cow - copy header of skb when it is required
2105 * @skb: buffer to cow
2106 * @headroom: needed headroom
2108 * If the skb passed lacks sufficient headroom or its data part
2109 * is shared, data is reallocated. If reallocation fails, an error
2110 * is returned and original skb is not changed.
2112 * The result is skb with writable area skb->head...skb->tail
2113 * and at least @headroom of space at head.
2115 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2117 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2121 * skb_cow_head - skb_cow but only making the head writable
2122 * @skb: buffer to cow
2123 * @headroom: needed headroom
2125 * This function is identical to skb_cow except that we replace the
2126 * skb_cloned check by skb_header_cloned. It should be used when
2127 * you only need to push on some header and do not need to modify
2130 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2132 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2136 * skb_padto - pad an skbuff up to a minimal size
2137 * @skb: buffer to pad
2138 * @len: minimal length
2140 * Pads up a buffer to ensure the trailing bytes exist and are
2141 * blanked. If the buffer already contains sufficient data it
2142 * is untouched. Otherwise it is extended. Returns zero on
2143 * success. The skb is freed on error.
2146 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2148 unsigned int size
= skb
->len
;
2149 if (likely(size
>= len
))
2151 return skb_pad(skb
, len
- size
);
2154 static inline int skb_add_data(struct sk_buff
*skb
,
2155 char __user
*from
, int copy
)
2157 const int off
= skb
->len
;
2159 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2161 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2164 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2167 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2170 __skb_trim(skb
, off
);
2174 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2175 const struct page
*page
, int off
)
2178 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2180 return page
== skb_frag_page(frag
) &&
2181 off
== frag
->page_offset
+ skb_frag_size(frag
);
2186 static inline int __skb_linearize(struct sk_buff
*skb
)
2188 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2192 * skb_linearize - convert paged skb to linear one
2193 * @skb: buffer to linarize
2195 * If there is no free memory -ENOMEM is returned, otherwise zero
2196 * is returned and the old skb data released.
2198 static inline int skb_linearize(struct sk_buff
*skb
)
2200 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2204 * skb_linearize_cow - make sure skb is linear and writable
2205 * @skb: buffer to process
2207 * If there is no free memory -ENOMEM is returned, otherwise zero
2208 * is returned and the old skb data released.
2210 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2212 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2213 __skb_linearize(skb
) : 0;
2217 * skb_postpull_rcsum - update checksum for received skb after pull
2218 * @skb: buffer to update
2219 * @start: start of data before pull
2220 * @len: length of data pulled
2222 * After doing a pull on a received packet, you need to call this to
2223 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2224 * CHECKSUM_NONE so that it can be recomputed from scratch.
2227 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2228 const void *start
, unsigned int len
)
2230 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2231 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2234 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2237 * pskb_trim_rcsum - trim received skb and update checksum
2238 * @skb: buffer to trim
2241 * This is exactly the same as pskb_trim except that it ensures the
2242 * checksum of received packets are still valid after the operation.
2245 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2247 if (likely(len
>= skb
->len
))
2249 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2250 skb
->ip_summed
= CHECKSUM_NONE
;
2251 return __pskb_trim(skb
, len
);
2254 #define skb_queue_walk(queue, skb) \
2255 for (skb = (queue)->next; \
2256 skb != (struct sk_buff *)(queue); \
2259 #define skb_queue_walk_safe(queue, skb, tmp) \
2260 for (skb = (queue)->next, tmp = skb->next; \
2261 skb != (struct sk_buff *)(queue); \
2262 skb = tmp, tmp = skb->next)
2264 #define skb_queue_walk_from(queue, skb) \
2265 for (; skb != (struct sk_buff *)(queue); \
2268 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2269 for (tmp = skb->next; \
2270 skb != (struct sk_buff *)(queue); \
2271 skb = tmp, tmp = skb->next)
2273 #define skb_queue_reverse_walk(queue, skb) \
2274 for (skb = (queue)->prev; \
2275 skb != (struct sk_buff *)(queue); \
2278 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2279 for (skb = (queue)->prev, tmp = skb->prev; \
2280 skb != (struct sk_buff *)(queue); \
2281 skb = tmp, tmp = skb->prev)
2283 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2284 for (tmp = skb->prev; \
2285 skb != (struct sk_buff *)(queue); \
2286 skb = tmp, tmp = skb->prev)
2288 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2290 return skb_shinfo(skb
)->frag_list
!= NULL
;
2293 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2295 skb_shinfo(skb
)->frag_list
= NULL
;
2298 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2300 frag
->next
= skb_shinfo(skb
)->frag_list
;
2301 skb_shinfo(skb
)->frag_list
= frag
;
2304 #define skb_walk_frags(skb, iter) \
2305 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2307 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2308 int *peeked
, int *off
, int *err
);
2309 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2310 int noblock
, int *err
);
2311 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2312 struct poll_table_struct
*wait
);
2313 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
2314 int offset
, struct iovec
*to
,
2316 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
2319 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
2321 const struct iovec
*from
,
2324 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
2326 const struct iovec
*to
,
2329 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2330 extern void skb_free_datagram_locked(struct sock
*sk
,
2331 struct sk_buff
*skb
);
2332 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
2333 unsigned int flags
);
2334 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
2335 int len
, __wsum csum
);
2336 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
2338 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
2339 const void *from
, int len
);
2340 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
2341 int offset
, u8
*to
, int len
,
2343 extern int skb_splice_bits(struct sk_buff
*skb
,
2344 unsigned int offset
,
2345 struct pipe_inode_info
*pipe
,
2347 unsigned int flags
);
2348 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2349 extern void skb_split(struct sk_buff
*skb
,
2350 struct sk_buff
*skb1
, const u32 len
);
2351 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
2354 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
,
2355 netdev_features_t features
);
2357 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2358 int len
, void *buffer
)
2360 int hlen
= skb_headlen(skb
);
2362 if (hlen
- offset
>= len
)
2363 return skb
->data
+ offset
;
2365 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2371 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2373 const unsigned int len
)
2375 memcpy(to
, skb
->data
, len
);
2378 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2379 const int offset
, void *to
,
2380 const unsigned int len
)
2382 memcpy(to
, skb
->data
+ offset
, len
);
2385 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2387 const unsigned int len
)
2389 memcpy(skb
->data
, from
, len
);
2392 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2395 const unsigned int len
)
2397 memcpy(skb
->data
+ offset
, from
, len
);
2400 extern void skb_init(void);
2402 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2408 * skb_get_timestamp - get timestamp from a skb
2409 * @skb: skb to get stamp from
2410 * @stamp: pointer to struct timeval to store stamp in
2412 * Timestamps are stored in the skb as offsets to a base timestamp.
2413 * This function converts the offset back to a struct timeval and stores
2416 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2417 struct timeval
*stamp
)
2419 *stamp
= ktime_to_timeval(skb
->tstamp
);
2422 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2423 struct timespec
*stamp
)
2425 *stamp
= ktime_to_timespec(skb
->tstamp
);
2428 static inline void __net_timestamp(struct sk_buff
*skb
)
2430 skb
->tstamp
= ktime_get_real();
2433 static inline ktime_t
net_timedelta(ktime_t t
)
2435 return ktime_sub(ktime_get_real(), t
);
2438 static inline ktime_t
net_invalid_timestamp(void)
2440 return ktime_set(0, 0);
2443 extern void skb_timestamping_init(void);
2445 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2447 extern void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2448 extern bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2450 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2452 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2456 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2461 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2464 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2466 * PHY drivers may accept clones of transmitted packets for
2467 * timestamping via their phy_driver.txtstamp method. These drivers
2468 * must call this function to return the skb back to the stack, with
2469 * or without a timestamp.
2471 * @skb: clone of the the original outgoing packet
2472 * @hwtstamps: hardware time stamps, may be NULL if not available
2475 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2476 struct skb_shared_hwtstamps
*hwtstamps
);
2479 * skb_tstamp_tx - queue clone of skb with send time stamps
2480 * @orig_skb: the original outgoing packet
2481 * @hwtstamps: hardware time stamps, may be NULL if not available
2483 * If the skb has a socket associated, then this function clones the
2484 * skb (thus sharing the actual data and optional structures), stores
2485 * the optional hardware time stamping information (if non NULL) or
2486 * generates a software time stamp (otherwise), then queues the clone
2487 * to the error queue of the socket. Errors are silently ignored.
2489 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2490 struct skb_shared_hwtstamps
*hwtstamps
);
2492 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2494 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2495 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2496 skb_tstamp_tx(skb
, NULL
);
2500 * skb_tx_timestamp() - Driver hook for transmit timestamping
2502 * Ethernet MAC Drivers should call this function in their hard_xmit()
2503 * function immediately before giving the sk_buff to the MAC hardware.
2505 * @skb: A socket buffer.
2507 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2509 skb_clone_tx_timestamp(skb
);
2510 sw_tx_timestamp(skb
);
2514 * skb_complete_wifi_ack - deliver skb with wifi status
2516 * @skb: the original outgoing packet
2517 * @acked: ack status
2520 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2522 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2523 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2525 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2527 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
2531 * skb_checksum_complete - Calculate checksum of an entire packet
2532 * @skb: packet to process
2534 * This function calculates the checksum over the entire packet plus
2535 * the value of skb->csum. The latter can be used to supply the
2536 * checksum of a pseudo header as used by TCP/UDP. It returns the
2539 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2540 * this function can be used to verify that checksum on received
2541 * packets. In that case the function should return zero if the
2542 * checksum is correct. In particular, this function will return zero
2543 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2544 * hardware has already verified the correctness of the checksum.
2546 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2548 return skb_csum_unnecessary(skb
) ?
2549 0 : __skb_checksum_complete(skb
);
2552 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2553 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2554 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2556 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2557 nf_conntrack_destroy(nfct
);
2559 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2562 atomic_inc(&nfct
->use
);
2565 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2566 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
2569 atomic_inc(&skb
->users
);
2571 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
2577 #ifdef CONFIG_BRIDGE_NETFILTER
2578 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2580 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2583 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2586 atomic_inc(&nf_bridge
->use
);
2588 #endif /* CONFIG_BRIDGE_NETFILTER */
2589 static inline void nf_reset(struct sk_buff
*skb
)
2591 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2592 nf_conntrack_put(skb
->nfct
);
2595 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2596 nf_conntrack_put_reasm(skb
->nfct_reasm
);
2597 skb
->nfct_reasm
= NULL
;
2599 #ifdef CONFIG_BRIDGE_NETFILTER
2600 nf_bridge_put(skb
->nf_bridge
);
2601 skb
->nf_bridge
= NULL
;
2605 /* Note: This doesn't put any conntrack and bridge info in dst. */
2606 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2608 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2609 dst
->nfct
= src
->nfct
;
2610 nf_conntrack_get(src
->nfct
);
2611 dst
->nfctinfo
= src
->nfctinfo
;
2613 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2614 dst
->nfct_reasm
= src
->nfct_reasm
;
2615 nf_conntrack_get_reasm(src
->nfct_reasm
);
2617 #ifdef CONFIG_BRIDGE_NETFILTER
2618 dst
->nf_bridge
= src
->nf_bridge
;
2619 nf_bridge_get(src
->nf_bridge
);
2623 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2625 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2626 nf_conntrack_put(dst
->nfct
);
2628 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2629 nf_conntrack_put_reasm(dst
->nfct_reasm
);
2631 #ifdef CONFIG_BRIDGE_NETFILTER
2632 nf_bridge_put(dst
->nf_bridge
);
2634 __nf_copy(dst
, src
);
2637 #ifdef CONFIG_NETWORK_SECMARK
2638 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2640 to
->secmark
= from
->secmark
;
2643 static inline void skb_init_secmark(struct sk_buff
*skb
)
2648 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2651 static inline void skb_init_secmark(struct sk_buff
*skb
)
2655 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2657 skb
->queue_mapping
= queue_mapping
;
2660 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2662 return skb
->queue_mapping
;
2665 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2667 to
->queue_mapping
= from
->queue_mapping
;
2670 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2672 skb
->queue_mapping
= rx_queue
+ 1;
2675 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2677 return skb
->queue_mapping
- 1;
2680 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2682 return skb
->queue_mapping
!= 0;
2685 extern u16
__skb_tx_hash(const struct net_device
*dev
,
2686 const struct sk_buff
*skb
,
2687 unsigned int num_tx_queues
);
2690 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2695 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2701 static inline bool skb_is_gso(const struct sk_buff
*skb
)
2703 return skb_shinfo(skb
)->gso_size
;
2706 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
2708 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2711 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2713 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2715 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2716 * wanted then gso_type will be set. */
2717 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2719 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
2720 unlikely(shinfo
->gso_type
== 0)) {
2721 __skb_warn_lro_forwarding(skb
);
2727 static inline void skb_forward_csum(struct sk_buff
*skb
)
2729 /* Unfortunately we don't support this one. Any brave souls? */
2730 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2731 skb
->ip_summed
= CHECKSUM_NONE
;
2735 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2736 * @skb: skb to check
2738 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2739 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2740 * use this helper, to document places where we make this assertion.
2742 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
2745 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
2749 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2752 * skb_head_is_locked - Determine if the skb->head is locked down
2753 * @skb: skb to check
2755 * The head on skbs build around a head frag can be removed if they are
2756 * not cloned. This function returns true if the skb head is locked down
2757 * due to either being allocated via kmalloc, or by being a clone with
2758 * multiple references to the head.
2760 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
2762 return !skb
->head_frag
|| skb_cloned(skb
);
2764 #endif /* __KERNEL__ */
2765 #endif /* _LINUX_SKBUFF_H */