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 ctx field is used to track device context.
239 * The desc field is used to track userspace buffer index.
242 void (*callback
)(struct ubuf_info
*);
247 /* This data is invariant across clones and lives at
248 * the end of the header data, ie. at skb->end.
250 struct skb_shared_info
{
251 unsigned char nr_frags
;
253 unsigned short gso_size
;
254 /* Warning: this field is not always filled in (UFO)! */
255 unsigned short gso_segs
;
256 unsigned short gso_type
;
257 struct sk_buff
*frag_list
;
258 struct skb_shared_hwtstamps hwtstamps
;
262 * Warning : all fields before dataref are cleared in __alloc_skb()
266 /* Intermediate layers must ensure that destructor_arg
267 * remains valid until skb destructor */
268 void * destructor_arg
;
270 /* must be last field, see pskb_expand_head() */
271 skb_frag_t frags
[MAX_SKB_FRAGS
];
274 /* We divide dataref into two halves. The higher 16 bits hold references
275 * to the payload part of skb->data. The lower 16 bits hold references to
276 * the entire skb->data. A clone of a headerless skb holds the length of
277 * the header in skb->hdr_len.
279 * All users must obey the rule that the skb->data reference count must be
280 * greater than or equal to the payload reference count.
282 * Holding a reference to the payload part means that the user does not
283 * care about modifications to the header part of skb->data.
285 #define SKB_DATAREF_SHIFT 16
286 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
290 SKB_FCLONE_UNAVAILABLE
,
296 SKB_GSO_TCPV4
= 1 << 0,
297 SKB_GSO_UDP
= 1 << 1,
299 /* This indicates the skb is from an untrusted source. */
300 SKB_GSO_DODGY
= 1 << 2,
302 /* This indicates the tcp segment has CWR set. */
303 SKB_GSO_TCP_ECN
= 1 << 3,
305 SKB_GSO_TCPV6
= 1 << 4,
307 SKB_GSO_FCOE
= 1 << 5,
310 #if BITS_PER_LONG > 32
311 #define NET_SKBUFF_DATA_USES_OFFSET 1
314 #ifdef NET_SKBUFF_DATA_USES_OFFSET
315 typedef unsigned int sk_buff_data_t
;
317 typedef unsigned char *sk_buff_data_t
;
320 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
321 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
322 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
326 * struct sk_buff - socket buffer
327 * @next: Next buffer in list
328 * @prev: Previous buffer in list
329 * @tstamp: Time we arrived
330 * @sk: Socket we are owned by
331 * @dev: Device we arrived on/are leaving by
332 * @cb: Control buffer. Free for use by every layer. Put private vars here
333 * @_skb_refdst: destination entry (with norefcount bit)
334 * @sp: the security path, used for xfrm
335 * @len: Length of actual data
336 * @data_len: Data length
337 * @mac_len: Length of link layer header
338 * @hdr_len: writable header length of cloned skb
339 * @csum: Checksum (must include start/offset pair)
340 * @csum_start: Offset from skb->head where checksumming should start
341 * @csum_offset: Offset from csum_start where checksum should be stored
342 * @priority: Packet queueing priority
343 * @local_df: allow local fragmentation
344 * @cloned: Head may be cloned (check refcnt to be sure)
345 * @ip_summed: Driver fed us an IP checksum
346 * @nohdr: Payload reference only, must not modify header
347 * @nfctinfo: Relationship of this skb to the connection
348 * @pkt_type: Packet class
349 * @fclone: skbuff clone status
350 * @ipvs_property: skbuff is owned by ipvs
351 * @peeked: this packet has been seen already, so stats have been
352 * done for it, don't do them again
353 * @nf_trace: netfilter packet trace flag
354 * @protocol: Packet protocol from driver
355 * @destructor: Destruct function
356 * @nfct: Associated connection, if any
357 * @nfct_reasm: netfilter conntrack re-assembly pointer
358 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
359 * @skb_iif: ifindex of device we arrived on
360 * @tc_index: Traffic control index
361 * @tc_verd: traffic control verdict
362 * @rxhash: the packet hash computed on receive
363 * @queue_mapping: Queue mapping for multiqueue devices
364 * @ndisc_nodetype: router type (from link layer)
365 * @ooo_okay: allow the mapping of a socket to a queue to be changed
366 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
368 * @wifi_acked_valid: wifi_acked was set
369 * @wifi_acked: whether frame was acked on wifi or not
370 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
371 * @dma_cookie: a cookie to one of several possible DMA operations
372 * done by skb DMA functions
373 * @secmark: security marking
374 * @mark: Generic packet mark
375 * @dropcount: total number of sk_receive_queue overflows
376 * @vlan_tci: vlan tag control information
377 * @transport_header: Transport layer header
378 * @network_header: Network layer header
379 * @mac_header: Link layer header
380 * @tail: Tail pointer
382 * @head: Head of buffer
383 * @data: Data head pointer
384 * @truesize: Buffer size
385 * @users: User count - see {datagram,tcp}.c
389 /* These two members must be first. */
390 struct sk_buff
*next
;
391 struct sk_buff
*prev
;
396 struct net_device
*dev
;
399 * This is the control buffer. It is free to use for every
400 * layer. Please put your private variables there. If you
401 * want to keep them across layers you have to do a skb_clone()
402 * first. This is owned by whoever has the skb queued ATM.
404 char cb
[48] __aligned(8);
406 unsigned long _skb_refdst
;
422 kmemcheck_bitfield_begin(flags1
);
433 kmemcheck_bitfield_end(flags1
);
436 void (*destructor
)(struct sk_buff
*skb
);
437 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
438 struct nf_conntrack
*nfct
;
440 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
441 struct sk_buff
*nfct_reasm
;
443 #ifdef CONFIG_BRIDGE_NETFILTER
444 struct nf_bridge_info
*nf_bridge
;
453 #ifdef CONFIG_NET_SCHED
454 __u16 tc_index
; /* traffic control index */
455 #ifdef CONFIG_NET_CLS_ACT
456 __u16 tc_verd
; /* traffic control verdict */
461 kmemcheck_bitfield_begin(flags2
);
462 #ifdef CONFIG_IPV6_NDISC_NODETYPE
463 __u8 ndisc_nodetype
:2;
468 __u8 wifi_acked_valid
:1;
472 /* 8/10 bit hole (depending on ndisc_nodetype presence) */
473 kmemcheck_bitfield_end(flags2
);
475 #ifdef CONFIG_NET_DMA
476 dma_cookie_t dma_cookie
;
478 #ifdef CONFIG_NETWORK_SECMARK
487 sk_buff_data_t transport_header
;
488 sk_buff_data_t network_header
;
489 sk_buff_data_t mac_header
;
490 /* These elements must be at the end, see alloc_skb() for details. */
495 unsigned int truesize
;
501 * Handling routines are only of interest to the kernel
503 #include <linux/slab.h>
506 #define SKB_ALLOC_FCLONE 0x01
507 #define SKB_ALLOC_RX 0x02
509 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
510 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
512 return unlikely(skb
->pfmemalloc
);
516 * skb might have a dst pointer attached, refcounted or not.
517 * _skb_refdst low order bit is set if refcount was _not_ taken
519 #define SKB_DST_NOREF 1UL
520 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
523 * skb_dst - returns skb dst_entry
526 * Returns skb dst_entry, regardless of reference taken or not.
528 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
530 /* If refdst was not refcounted, check we still are in a
531 * rcu_read_lock section
533 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
534 !rcu_read_lock_held() &&
535 !rcu_read_lock_bh_held());
536 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
540 * skb_dst_set - sets skb dst
544 * Sets skb dst, assuming a reference was taken on dst and should
545 * be released by skb_dst_drop()
547 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
549 skb
->_skb_refdst
= (unsigned long)dst
;
552 extern void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
);
555 * skb_dst_is_noref - Test if skb dst isn't refcounted
558 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
560 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
563 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
565 return (struct rtable
*)skb_dst(skb
);
568 extern void kfree_skb(struct sk_buff
*skb
);
569 extern void consume_skb(struct sk_buff
*skb
);
570 extern void __kfree_skb(struct sk_buff
*skb
);
571 extern struct kmem_cache
*skbuff_head_cache
;
573 extern void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
574 extern bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
575 bool *fragstolen
, int *delta_truesize
);
577 extern struct sk_buff
*__alloc_skb(unsigned int size
,
578 gfp_t priority
, int flags
, int node
);
579 extern struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
580 static inline struct sk_buff
*alloc_skb(unsigned int size
,
583 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
586 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
589 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
592 extern void skb_recycle(struct sk_buff
*skb
);
593 extern bool skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
595 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
596 extern int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
597 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
599 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
601 extern struct sk_buff
*__pskb_copy(struct sk_buff
*skb
,
602 int headroom
, gfp_t gfp_mask
);
604 extern int pskb_expand_head(struct sk_buff
*skb
,
605 int nhead
, int ntail
,
607 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
608 unsigned int headroom
);
609 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
610 int newheadroom
, int newtailroom
,
612 extern int skb_to_sgvec(struct sk_buff
*skb
,
613 struct scatterlist
*sg
, int offset
,
615 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
616 struct sk_buff
**trailer
);
617 extern int skb_pad(struct sk_buff
*skb
, int pad
);
618 #define dev_kfree_skb(a) consume_skb(a)
620 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
621 int getfrag(void *from
, char *to
, int offset
,
622 int len
,int odd
, struct sk_buff
*skb
),
623 void *from
, int length
);
625 struct skb_seq_state
{
629 __u32 stepped_offset
;
630 struct sk_buff
*root_skb
;
631 struct sk_buff
*cur_skb
;
635 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
636 unsigned int from
, unsigned int to
,
637 struct skb_seq_state
*st
);
638 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
639 struct skb_seq_state
*st
);
640 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
642 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
643 unsigned int to
, struct ts_config
*config
,
644 struct ts_state
*state
);
646 extern void __skb_get_rxhash(struct sk_buff
*skb
);
647 static inline __u32
skb_get_rxhash(struct sk_buff
*skb
)
650 __skb_get_rxhash(skb
);
655 #ifdef NET_SKBUFF_DATA_USES_OFFSET
656 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
658 return skb
->head
+ skb
->end
;
661 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
666 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
671 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
673 return skb
->end
- skb
->head
;
678 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
680 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
682 return &skb_shinfo(skb
)->hwtstamps
;
686 * skb_queue_empty - check if a queue is empty
689 * Returns true if the queue is empty, false otherwise.
691 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
693 return list
->next
== (struct sk_buff
*)list
;
697 * skb_queue_is_last - check if skb is the last entry in the queue
701 * Returns true if @skb is the last buffer on the list.
703 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
704 const struct sk_buff
*skb
)
706 return skb
->next
== (struct sk_buff
*)list
;
710 * skb_queue_is_first - check if skb is the first entry in the queue
714 * Returns true if @skb is the first buffer on the list.
716 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
717 const struct sk_buff
*skb
)
719 return skb
->prev
== (struct sk_buff
*)list
;
723 * skb_queue_next - return the next packet in the queue
725 * @skb: current buffer
727 * Return the next packet in @list after @skb. It is only valid to
728 * call this if skb_queue_is_last() evaluates to false.
730 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
731 const struct sk_buff
*skb
)
733 /* This BUG_ON may seem severe, but if we just return then we
734 * are going to dereference garbage.
736 BUG_ON(skb_queue_is_last(list
, skb
));
741 * skb_queue_prev - return the prev packet in the queue
743 * @skb: current buffer
745 * Return the prev packet in @list before @skb. It is only valid to
746 * call this if skb_queue_is_first() evaluates to false.
748 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
749 const struct sk_buff
*skb
)
751 /* This BUG_ON may seem severe, but if we just return then we
752 * are going to dereference garbage.
754 BUG_ON(skb_queue_is_first(list
, skb
));
759 * skb_get - reference buffer
760 * @skb: buffer to reference
762 * Makes another reference to a socket buffer and returns a pointer
765 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
767 atomic_inc(&skb
->users
);
772 * If users == 1, we are the only owner and are can avoid redundant
777 * skb_cloned - is the buffer a clone
778 * @skb: buffer to check
780 * Returns true if the buffer was generated with skb_clone() and is
781 * one of multiple shared copies of the buffer. Cloned buffers are
782 * shared data so must not be written to under normal circumstances.
784 static inline int skb_cloned(const struct sk_buff
*skb
)
786 return skb
->cloned
&&
787 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
791 * skb_header_cloned - is the header a clone
792 * @skb: buffer to check
794 * Returns true if modifying the header part of the buffer requires
795 * the data to be copied.
797 static inline int skb_header_cloned(const struct sk_buff
*skb
)
804 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
805 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
810 * skb_header_release - release reference to header
811 * @skb: buffer to operate on
813 * Drop a reference to the header part of the buffer. This is done
814 * by acquiring a payload reference. You must not read from the header
815 * part of skb->data after this.
817 static inline void skb_header_release(struct sk_buff
*skb
)
821 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
825 * skb_shared - is the buffer shared
826 * @skb: buffer to check
828 * Returns true if more than one person has a reference to this
831 static inline int skb_shared(const struct sk_buff
*skb
)
833 return atomic_read(&skb
->users
) != 1;
837 * skb_share_check - check if buffer is shared and if so clone it
838 * @skb: buffer to check
839 * @pri: priority for memory allocation
841 * If the buffer is shared the buffer is cloned and the old copy
842 * drops a reference. A new clone with a single reference is returned.
843 * If the buffer is not shared the original buffer is returned. When
844 * being called from interrupt status or with spinlocks held pri must
847 * NULL is returned on a memory allocation failure.
849 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
851 might_sleep_if(pri
& __GFP_WAIT
);
852 if (skb_shared(skb
)) {
853 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
865 * Copy shared buffers into a new sk_buff. We effectively do COW on
866 * packets to handle cases where we have a local reader and forward
867 * and a couple of other messy ones. The normal one is tcpdumping
868 * a packet thats being forwarded.
872 * skb_unshare - make a copy of a shared buffer
873 * @skb: buffer to check
874 * @pri: priority for memory allocation
876 * If the socket buffer is a clone then this function creates a new
877 * copy of the data, drops a reference count on the old copy and returns
878 * the new copy with the reference count at 1. If the buffer is not a clone
879 * the original buffer is returned. When called with a spinlock held or
880 * from interrupt state @pri must be %GFP_ATOMIC
882 * %NULL is returned on a memory allocation failure.
884 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
887 might_sleep_if(pri
& __GFP_WAIT
);
888 if (skb_cloned(skb
)) {
889 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
890 kfree_skb(skb
); /* Free our shared copy */
897 * skb_peek - peek at the head of an &sk_buff_head
898 * @list_: list to peek at
900 * Peek an &sk_buff. Unlike most other operations you _MUST_
901 * be careful with this one. A peek leaves the buffer on the
902 * list and someone else may run off with it. You must hold
903 * the appropriate locks or have a private queue to do this.
905 * Returns %NULL for an empty list or a pointer to the head element.
906 * The reference count is not incremented and the reference is therefore
907 * volatile. Use with caution.
909 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
911 struct sk_buff
*skb
= list_
->next
;
913 if (skb
== (struct sk_buff
*)list_
)
919 * skb_peek_next - peek skb following the given one from a queue
920 * @skb: skb to start from
921 * @list_: list to peek at
923 * Returns %NULL when the end of the list is met or a pointer to the
924 * next element. The reference count is not incremented and the
925 * reference is therefore volatile. Use with caution.
927 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
928 const struct sk_buff_head
*list_
)
930 struct sk_buff
*next
= skb
->next
;
932 if (next
== (struct sk_buff
*)list_
)
938 * skb_peek_tail - peek at the tail of an &sk_buff_head
939 * @list_: list to peek at
941 * Peek an &sk_buff. Unlike most other operations you _MUST_
942 * be careful with this one. A peek leaves the buffer on the
943 * list and someone else may run off with it. You must hold
944 * the appropriate locks or have a private queue to do this.
946 * Returns %NULL for an empty list or a pointer to the tail element.
947 * The reference count is not incremented and the reference is therefore
948 * volatile. Use with caution.
950 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
952 struct sk_buff
*skb
= list_
->prev
;
954 if (skb
== (struct sk_buff
*)list_
)
961 * skb_queue_len - get queue length
962 * @list_: list to measure
964 * Return the length of an &sk_buff queue.
966 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
972 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
973 * @list: queue to initialize
975 * This initializes only the list and queue length aspects of
976 * an sk_buff_head object. This allows to initialize the list
977 * aspects of an sk_buff_head without reinitializing things like
978 * the spinlock. It can also be used for on-stack sk_buff_head
979 * objects where the spinlock is known to not be used.
981 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
983 list
->prev
= list
->next
= (struct sk_buff
*)list
;
988 * This function creates a split out lock class for each invocation;
989 * this is needed for now since a whole lot of users of the skb-queue
990 * infrastructure in drivers have different locking usage (in hardirq)
991 * than the networking core (in softirq only). In the long run either the
992 * network layer or drivers should need annotation to consolidate the
993 * main types of usage into 3 classes.
995 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
997 spin_lock_init(&list
->lock
);
998 __skb_queue_head_init(list
);
1001 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1002 struct lock_class_key
*class)
1004 skb_queue_head_init(list
);
1005 lockdep_set_class(&list
->lock
, class);
1009 * Insert an sk_buff on a list.
1011 * The "__skb_xxxx()" functions are the non-atomic ones that
1012 * can only be called with interrupts disabled.
1014 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
1015 static inline void __skb_insert(struct sk_buff
*newsk
,
1016 struct sk_buff
*prev
, struct sk_buff
*next
,
1017 struct sk_buff_head
*list
)
1021 next
->prev
= prev
->next
= newsk
;
1025 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1026 struct sk_buff
*prev
,
1027 struct sk_buff
*next
)
1029 struct sk_buff
*first
= list
->next
;
1030 struct sk_buff
*last
= list
->prev
;
1040 * skb_queue_splice - join two skb lists, this is designed for stacks
1041 * @list: the new list to add
1042 * @head: the place to add it in the first list
1044 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1045 struct sk_buff_head
*head
)
1047 if (!skb_queue_empty(list
)) {
1048 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1049 head
->qlen
+= list
->qlen
;
1054 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1055 * @list: the new list to add
1056 * @head: the place to add it in the first list
1058 * The list at @list is reinitialised
1060 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1061 struct sk_buff_head
*head
)
1063 if (!skb_queue_empty(list
)) {
1064 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1065 head
->qlen
+= list
->qlen
;
1066 __skb_queue_head_init(list
);
1071 * skb_queue_splice_tail - join two skb lists, each list being a queue
1072 * @list: the new list to add
1073 * @head: the place to add it in the first list
1075 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1076 struct sk_buff_head
*head
)
1078 if (!skb_queue_empty(list
)) {
1079 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1080 head
->qlen
+= list
->qlen
;
1085 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1086 * @list: the new list to add
1087 * @head: the place to add it in the first list
1089 * Each of the lists is a queue.
1090 * The list at @list is reinitialised
1092 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1093 struct sk_buff_head
*head
)
1095 if (!skb_queue_empty(list
)) {
1096 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1097 head
->qlen
+= list
->qlen
;
1098 __skb_queue_head_init(list
);
1103 * __skb_queue_after - queue a buffer at the list head
1104 * @list: list to use
1105 * @prev: place after this buffer
1106 * @newsk: buffer to queue
1108 * Queue a buffer int the middle of a list. This function takes no locks
1109 * and you must therefore hold required locks before calling it.
1111 * A buffer cannot be placed on two lists at the same time.
1113 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1114 struct sk_buff
*prev
,
1115 struct sk_buff
*newsk
)
1117 __skb_insert(newsk
, prev
, prev
->next
, list
);
1120 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1121 struct sk_buff_head
*list
);
1123 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1124 struct sk_buff
*next
,
1125 struct sk_buff
*newsk
)
1127 __skb_insert(newsk
, next
->prev
, next
, list
);
1131 * __skb_queue_head - queue a buffer at the list head
1132 * @list: list to use
1133 * @newsk: buffer to queue
1135 * Queue a buffer at the start of a list. This function takes no locks
1136 * and you must therefore hold required locks before calling it.
1138 * A buffer cannot be placed on two lists at the same time.
1140 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1141 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1142 struct sk_buff
*newsk
)
1144 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1148 * __skb_queue_tail - queue a buffer at the list tail
1149 * @list: list to use
1150 * @newsk: buffer to queue
1152 * Queue a buffer at the end of a list. This function takes no locks
1153 * and you must therefore hold required locks before calling it.
1155 * A buffer cannot be placed on two lists at the same time.
1157 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1158 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1159 struct sk_buff
*newsk
)
1161 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1165 * remove sk_buff from list. _Must_ be called atomically, and with
1168 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1169 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1171 struct sk_buff
*next
, *prev
;
1176 skb
->next
= skb
->prev
= NULL
;
1182 * __skb_dequeue - remove from the head of the queue
1183 * @list: list to dequeue from
1185 * Remove the head of the list. This function does not take any locks
1186 * so must be used with appropriate locks held only. The head item is
1187 * returned or %NULL if the list is empty.
1189 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1190 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1192 struct sk_buff
*skb
= skb_peek(list
);
1194 __skb_unlink(skb
, list
);
1199 * __skb_dequeue_tail - remove from the tail of the queue
1200 * @list: list to dequeue from
1202 * Remove the tail of the list. This function does not take any locks
1203 * so must be used with appropriate locks held only. The tail item is
1204 * returned or %NULL if the list is empty.
1206 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1207 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1209 struct sk_buff
*skb
= skb_peek_tail(list
);
1211 __skb_unlink(skb
, list
);
1216 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1218 return skb
->data_len
;
1221 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1223 return skb
->len
- skb
->data_len
;
1226 static inline int skb_pagelen(const struct sk_buff
*skb
)
1230 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1231 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1232 return len
+ skb_headlen(skb
);
1236 * __skb_fill_page_desc - initialise a paged fragment in an skb
1237 * @skb: buffer containing fragment to be initialised
1238 * @i: paged fragment index to initialise
1239 * @page: the page to use for this fragment
1240 * @off: the offset to the data with @page
1241 * @size: the length of the data
1243 * Initialises the @i'th fragment of @skb to point to &size bytes at
1244 * offset @off within @page.
1246 * Does not take any additional reference on the fragment.
1248 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1249 struct page
*page
, int off
, int size
)
1251 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1254 * Propagate page->pfmemalloc to the skb if we can. The problem is
1255 * that not all callers have unique ownership of the page. If
1256 * pfmemalloc is set, we check the mapping as a mapping implies
1257 * page->index is set (index and pfmemalloc share space).
1258 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1259 * do not lose pfmemalloc information as the pages would not be
1260 * allocated using __GFP_MEMALLOC.
1262 if (page
->pfmemalloc
&& !page
->mapping
)
1263 skb
->pfmemalloc
= true;
1264 frag
->page
.p
= page
;
1265 frag
->page_offset
= off
;
1266 skb_frag_size_set(frag
, size
);
1270 * skb_fill_page_desc - initialise a paged fragment in an skb
1271 * @skb: buffer containing fragment to be initialised
1272 * @i: paged fragment index to initialise
1273 * @page: the page to use for this fragment
1274 * @off: the offset to the data with @page
1275 * @size: the length of the data
1277 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1278 * @skb to point to &size bytes at offset @off within @page. In
1279 * addition updates @skb such that @i is the last fragment.
1281 * Does not take any additional reference on the fragment.
1283 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1284 struct page
*page
, int off
, int size
)
1286 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1287 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1290 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1291 int off
, int size
, unsigned int truesize
);
1293 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1294 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1295 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1297 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1298 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1300 return skb
->head
+ skb
->tail
;
1303 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1305 skb
->tail
= skb
->data
- skb
->head
;
1308 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1310 skb_reset_tail_pointer(skb
);
1311 skb
->tail
+= offset
;
1313 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1314 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1319 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1321 skb
->tail
= skb
->data
;
1324 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1326 skb
->tail
= skb
->data
+ offset
;
1329 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1332 * Add data to an sk_buff
1334 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1335 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1337 unsigned char *tmp
= skb_tail_pointer(skb
);
1338 SKB_LINEAR_ASSERT(skb
);
1344 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1345 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1352 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1353 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1356 BUG_ON(skb
->len
< skb
->data_len
);
1357 return skb
->data
+= len
;
1360 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1362 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1365 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1367 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1369 if (len
> skb_headlen(skb
) &&
1370 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1373 return skb
->data
+= len
;
1376 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1378 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1381 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1383 if (likely(len
<= skb_headlen(skb
)))
1385 if (unlikely(len
> skb
->len
))
1387 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1391 * skb_headroom - bytes at buffer head
1392 * @skb: buffer to check
1394 * Return the number of bytes of free space at the head of an &sk_buff.
1396 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1398 return skb
->data
- skb
->head
;
1402 * skb_tailroom - bytes at buffer end
1403 * @skb: buffer to check
1405 * Return the number of bytes of free space at the tail of an sk_buff
1407 static inline int skb_tailroom(const struct sk_buff
*skb
)
1409 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1413 * skb_availroom - bytes at buffer end
1414 * @skb: buffer to check
1416 * Return the number of bytes of free space at the tail of an sk_buff
1417 * allocated by sk_stream_alloc()
1419 static inline int skb_availroom(const struct sk_buff
*skb
)
1421 return skb_is_nonlinear(skb
) ? 0 : skb
->avail_size
- skb
->len
;
1425 * skb_reserve - adjust headroom
1426 * @skb: buffer to alter
1427 * @len: bytes to move
1429 * Increase the headroom of an empty &sk_buff by reducing the tail
1430 * room. This is only allowed for an empty buffer.
1432 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1438 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1440 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1443 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1444 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1446 return skb
->head
+ skb
->transport_header
;
1449 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1451 skb
->transport_header
= skb
->data
- skb
->head
;
1454 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1457 skb_reset_transport_header(skb
);
1458 skb
->transport_header
+= offset
;
1461 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1463 return skb
->head
+ skb
->network_header
;
1466 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1468 skb
->network_header
= skb
->data
- skb
->head
;
1471 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1473 skb_reset_network_header(skb
);
1474 skb
->network_header
+= offset
;
1477 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1479 return skb
->head
+ skb
->mac_header
;
1482 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1484 return skb
->mac_header
!= ~0U;
1487 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1489 skb
->mac_header
= skb
->data
- skb
->head
;
1492 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1494 skb_reset_mac_header(skb
);
1495 skb
->mac_header
+= offset
;
1498 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1500 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1502 return skb
->transport_header
;
1505 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1507 skb
->transport_header
= skb
->data
;
1510 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1513 skb
->transport_header
= skb
->data
+ offset
;
1516 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1518 return skb
->network_header
;
1521 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1523 skb
->network_header
= skb
->data
;
1526 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1528 skb
->network_header
= skb
->data
+ offset
;
1531 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1533 return skb
->mac_header
;
1536 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1538 return skb
->mac_header
!= NULL
;
1541 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1543 skb
->mac_header
= skb
->data
;
1546 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1548 skb
->mac_header
= skb
->data
+ offset
;
1550 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1552 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1554 if (skb_mac_header_was_set(skb
)) {
1555 const unsigned char *old_mac
= skb_mac_header(skb
);
1557 skb_set_mac_header(skb
, -skb
->mac_len
);
1558 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1562 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1564 return skb
->csum_start
- skb_headroom(skb
);
1567 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1569 return skb_transport_header(skb
) - skb
->data
;
1572 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1574 return skb
->transport_header
- skb
->network_header
;
1577 static inline int skb_network_offset(const struct sk_buff
*skb
)
1579 return skb_network_header(skb
) - skb
->data
;
1582 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1584 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1588 * CPUs often take a performance hit when accessing unaligned memory
1589 * locations. The actual performance hit varies, it can be small if the
1590 * hardware handles it or large if we have to take an exception and fix it
1593 * Since an ethernet header is 14 bytes network drivers often end up with
1594 * the IP header at an unaligned offset. The IP header can be aligned by
1595 * shifting the start of the packet by 2 bytes. Drivers should do this
1598 * skb_reserve(skb, NET_IP_ALIGN);
1600 * The downside to this alignment of the IP header is that the DMA is now
1601 * unaligned. On some architectures the cost of an unaligned DMA is high
1602 * and this cost outweighs the gains made by aligning the IP header.
1604 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1607 #ifndef NET_IP_ALIGN
1608 #define NET_IP_ALIGN 2
1612 * The networking layer reserves some headroom in skb data (via
1613 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1614 * the header has to grow. In the default case, if the header has to grow
1615 * 32 bytes or less we avoid the reallocation.
1617 * Unfortunately this headroom changes the DMA alignment of the resulting
1618 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1619 * on some architectures. An architecture can override this value,
1620 * perhaps setting it to a cacheline in size (since that will maintain
1621 * cacheline alignment of the DMA). It must be a power of 2.
1623 * Various parts of the networking layer expect at least 32 bytes of
1624 * headroom, you should not reduce this.
1626 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1627 * to reduce average number of cache lines per packet.
1628 * get_rps_cpus() for example only access one 64 bytes aligned block :
1629 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1632 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1635 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1637 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1639 if (unlikely(skb_is_nonlinear(skb
))) {
1644 skb_set_tail_pointer(skb
, len
);
1647 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1649 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1652 return ___pskb_trim(skb
, len
);
1653 __skb_trim(skb
, len
);
1657 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1659 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1663 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1664 * @skb: buffer to alter
1667 * This is identical to pskb_trim except that the caller knows that
1668 * the skb is not cloned so we should never get an error due to out-
1671 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1673 int err
= pskb_trim(skb
, len
);
1678 * skb_orphan - orphan a buffer
1679 * @skb: buffer to orphan
1681 * If a buffer currently has an owner then we call the owner's
1682 * destructor function and make the @skb unowned. The buffer continues
1683 * to exist but is no longer charged to its former owner.
1685 static inline void skb_orphan(struct sk_buff
*skb
)
1687 if (skb
->destructor
)
1688 skb
->destructor(skb
);
1689 skb
->destructor
= NULL
;
1694 * skb_orphan_frags - orphan the frags contained in a buffer
1695 * @skb: buffer to orphan frags from
1696 * @gfp_mask: allocation mask for replacement pages
1698 * For each frag in the SKB which needs a destructor (i.e. has an
1699 * owner) create a copy of that frag and release the original
1700 * page by calling the destructor.
1702 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1704 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1706 return skb_copy_ubufs(skb
, gfp_mask
);
1710 * __skb_queue_purge - empty a list
1711 * @list: list to empty
1713 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1714 * the list and one reference dropped. This function does not take the
1715 * list lock and the caller must hold the relevant locks to use it.
1717 extern void skb_queue_purge(struct sk_buff_head
*list
);
1718 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1720 struct sk_buff
*skb
;
1721 while ((skb
= __skb_dequeue(list
)) != NULL
)
1725 extern void *netdev_alloc_frag(unsigned int fragsz
);
1727 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1728 unsigned int length
,
1732 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1733 * @dev: network device to receive on
1734 * @length: length to allocate
1736 * Allocate a new &sk_buff and assign it a usage count of one. The
1737 * buffer has unspecified headroom built in. Users should allocate
1738 * the headroom they think they need without accounting for the
1739 * built in space. The built in space is used for optimisations.
1741 * %NULL is returned if there is no free memory. Although this function
1742 * allocates memory it can be called from an interrupt.
1744 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1745 unsigned int length
)
1747 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1750 /* legacy helper around __netdev_alloc_skb() */
1751 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1754 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
1757 /* legacy helper around netdev_alloc_skb() */
1758 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1760 return netdev_alloc_skb(NULL
, length
);
1764 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
1765 unsigned int length
, gfp_t gfp
)
1767 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
1769 if (NET_IP_ALIGN
&& skb
)
1770 skb_reserve(skb
, NET_IP_ALIGN
);
1774 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
1775 unsigned int length
)
1777 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
1781 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1782 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1783 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1784 * @order: size of the allocation
1786 * Allocate a new page.
1788 * %NULL is returned if there is no free memory.
1790 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
1791 struct sk_buff
*skb
,
1796 gfp_mask
|= __GFP_COLD
;
1798 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1799 gfp_mask
|= __GFP_MEMALLOC
;
1801 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
1802 if (skb
&& page
&& page
->pfmemalloc
)
1803 skb
->pfmemalloc
= true;
1809 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1810 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1811 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1813 * Allocate a new page.
1815 * %NULL is returned if there is no free memory.
1817 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
1818 struct sk_buff
*skb
)
1820 return __skb_alloc_pages(gfp_mask
, skb
, 0);
1824 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1825 * @page: The page that was allocated from skb_alloc_page
1826 * @skb: The skb that may need pfmemalloc set
1828 static inline void skb_propagate_pfmemalloc(struct page
*page
,
1829 struct sk_buff
*skb
)
1831 if (page
&& page
->pfmemalloc
)
1832 skb
->pfmemalloc
= true;
1836 * skb_frag_page - retrieve the page refered to by a paged fragment
1837 * @frag: the paged fragment
1839 * Returns the &struct page associated with @frag.
1841 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
1843 return frag
->page
.p
;
1847 * __skb_frag_ref - take an addition reference on a paged fragment.
1848 * @frag: the paged fragment
1850 * Takes an additional reference on the paged fragment @frag.
1852 static inline void __skb_frag_ref(skb_frag_t
*frag
)
1854 get_page(skb_frag_page(frag
));
1858 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1860 * @f: the fragment offset.
1862 * Takes an additional reference on the @f'th paged fragment of @skb.
1864 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
1866 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
1870 * __skb_frag_unref - release a reference on a paged fragment.
1871 * @frag: the paged fragment
1873 * Releases a reference on the paged fragment @frag.
1875 static inline void __skb_frag_unref(skb_frag_t
*frag
)
1877 put_page(skb_frag_page(frag
));
1881 * skb_frag_unref - release a reference on a paged fragment of an skb.
1883 * @f: the fragment offset
1885 * Releases a reference on the @f'th paged fragment of @skb.
1887 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
1889 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
1893 * skb_frag_address - gets the address of the data contained in a paged fragment
1894 * @frag: the paged fragment buffer
1896 * Returns the address of the data within @frag. The page must already
1899 static inline void *skb_frag_address(const skb_frag_t
*frag
)
1901 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
1905 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1906 * @frag: the paged fragment buffer
1908 * Returns the address of the data within @frag. Checks that the page
1909 * is mapped and returns %NULL otherwise.
1911 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
1913 void *ptr
= page_address(skb_frag_page(frag
));
1917 return ptr
+ frag
->page_offset
;
1921 * __skb_frag_set_page - sets the page contained in a paged fragment
1922 * @frag: the paged fragment
1923 * @page: the page to set
1925 * Sets the fragment @frag to contain @page.
1927 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
1929 frag
->page
.p
= page
;
1933 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1935 * @f: the fragment offset
1936 * @page: the page to set
1938 * Sets the @f'th fragment of @skb to contain @page.
1940 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
1943 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
1947 * skb_frag_dma_map - maps a paged fragment via the DMA API
1948 * @dev: the device to map the fragment to
1949 * @frag: the paged fragment to map
1950 * @offset: the offset within the fragment (starting at the
1951 * fragment's own offset)
1952 * @size: the number of bytes to map
1953 * @dir: the direction of the mapping (%PCI_DMA_*)
1955 * Maps the page associated with @frag to @device.
1957 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
1958 const skb_frag_t
*frag
,
1959 size_t offset
, size_t size
,
1960 enum dma_data_direction dir
)
1962 return dma_map_page(dev
, skb_frag_page(frag
),
1963 frag
->page_offset
+ offset
, size
, dir
);
1966 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
1969 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
1973 * skb_clone_writable - is the header of a clone writable
1974 * @skb: buffer to check
1975 * @len: length up to which to write
1977 * Returns true if modifying the header part of the cloned buffer
1978 * does not requires the data to be copied.
1980 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
1982 return !skb_header_cloned(skb
) &&
1983 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1986 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1991 if (headroom
> skb_headroom(skb
))
1992 delta
= headroom
- skb_headroom(skb
);
1994 if (delta
|| cloned
)
1995 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2001 * skb_cow - copy header of skb when it is required
2002 * @skb: buffer to cow
2003 * @headroom: needed headroom
2005 * If the skb passed lacks sufficient headroom or its data part
2006 * is shared, data is reallocated. If reallocation fails, an error
2007 * is returned and original skb is not changed.
2009 * The result is skb with writable area skb->head...skb->tail
2010 * and at least @headroom of space at head.
2012 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2014 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2018 * skb_cow_head - skb_cow but only making the head writable
2019 * @skb: buffer to cow
2020 * @headroom: needed headroom
2022 * This function is identical to skb_cow except that we replace the
2023 * skb_cloned check by skb_header_cloned. It should be used when
2024 * you only need to push on some header and do not need to modify
2027 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2029 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2033 * skb_padto - pad an skbuff up to a minimal size
2034 * @skb: buffer to pad
2035 * @len: minimal length
2037 * Pads up a buffer to ensure the trailing bytes exist and are
2038 * blanked. If the buffer already contains sufficient data it
2039 * is untouched. Otherwise it is extended. Returns zero on
2040 * success. The skb is freed on error.
2043 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2045 unsigned int size
= skb
->len
;
2046 if (likely(size
>= len
))
2048 return skb_pad(skb
, len
- size
);
2051 static inline int skb_add_data(struct sk_buff
*skb
,
2052 char __user
*from
, int copy
)
2054 const int off
= skb
->len
;
2056 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2058 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2061 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2064 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2067 __skb_trim(skb
, off
);
2071 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2072 const struct page
*page
, int off
)
2075 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2077 return page
== skb_frag_page(frag
) &&
2078 off
== frag
->page_offset
+ skb_frag_size(frag
);
2083 static inline int __skb_linearize(struct sk_buff
*skb
)
2085 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2089 * skb_linearize - convert paged skb to linear one
2090 * @skb: buffer to linarize
2092 * If there is no free memory -ENOMEM is returned, otherwise zero
2093 * is returned and the old skb data released.
2095 static inline int skb_linearize(struct sk_buff
*skb
)
2097 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2101 * skb_linearize_cow - make sure skb is linear and writable
2102 * @skb: buffer to process
2104 * If there is no free memory -ENOMEM is returned, otherwise zero
2105 * is returned and the old skb data released.
2107 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2109 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2110 __skb_linearize(skb
) : 0;
2114 * skb_postpull_rcsum - update checksum for received skb after pull
2115 * @skb: buffer to update
2116 * @start: start of data before pull
2117 * @len: length of data pulled
2119 * After doing a pull on a received packet, you need to call this to
2120 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2121 * CHECKSUM_NONE so that it can be recomputed from scratch.
2124 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2125 const void *start
, unsigned int len
)
2127 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2128 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2131 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2134 * pskb_trim_rcsum - trim received skb and update checksum
2135 * @skb: buffer to trim
2138 * This is exactly the same as pskb_trim except that it ensures the
2139 * checksum of received packets are still valid after the operation.
2142 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2144 if (likely(len
>= skb
->len
))
2146 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2147 skb
->ip_summed
= CHECKSUM_NONE
;
2148 return __pskb_trim(skb
, len
);
2151 #define skb_queue_walk(queue, skb) \
2152 for (skb = (queue)->next; \
2153 skb != (struct sk_buff *)(queue); \
2156 #define skb_queue_walk_safe(queue, skb, tmp) \
2157 for (skb = (queue)->next, tmp = skb->next; \
2158 skb != (struct sk_buff *)(queue); \
2159 skb = tmp, tmp = skb->next)
2161 #define skb_queue_walk_from(queue, skb) \
2162 for (; skb != (struct sk_buff *)(queue); \
2165 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2166 for (tmp = skb->next; \
2167 skb != (struct sk_buff *)(queue); \
2168 skb = tmp, tmp = skb->next)
2170 #define skb_queue_reverse_walk(queue, skb) \
2171 for (skb = (queue)->prev; \
2172 skb != (struct sk_buff *)(queue); \
2175 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2176 for (skb = (queue)->prev, tmp = skb->prev; \
2177 skb != (struct sk_buff *)(queue); \
2178 skb = tmp, tmp = skb->prev)
2180 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2181 for (tmp = skb->prev; \
2182 skb != (struct sk_buff *)(queue); \
2183 skb = tmp, tmp = skb->prev)
2185 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2187 return skb_shinfo(skb
)->frag_list
!= NULL
;
2190 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2192 skb_shinfo(skb
)->frag_list
= NULL
;
2195 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2197 frag
->next
= skb_shinfo(skb
)->frag_list
;
2198 skb_shinfo(skb
)->frag_list
= frag
;
2201 #define skb_walk_frags(skb, iter) \
2202 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2204 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2205 int *peeked
, int *off
, int *err
);
2206 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2207 int noblock
, int *err
);
2208 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2209 struct poll_table_struct
*wait
);
2210 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
2211 int offset
, struct iovec
*to
,
2213 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
2216 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
2218 const struct iovec
*from
,
2221 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
2223 const struct iovec
*to
,
2226 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2227 extern void skb_free_datagram_locked(struct sock
*sk
,
2228 struct sk_buff
*skb
);
2229 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
2230 unsigned int flags
);
2231 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
2232 int len
, __wsum csum
);
2233 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
2235 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
2236 const void *from
, int len
);
2237 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
2238 int offset
, u8
*to
, int len
,
2240 extern int skb_splice_bits(struct sk_buff
*skb
,
2241 unsigned int offset
,
2242 struct pipe_inode_info
*pipe
,
2244 unsigned int flags
);
2245 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2246 extern void skb_split(struct sk_buff
*skb
,
2247 struct sk_buff
*skb1
, const u32 len
);
2248 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
2251 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
,
2252 netdev_features_t features
);
2254 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2255 int len
, void *buffer
)
2257 int hlen
= skb_headlen(skb
);
2259 if (hlen
- offset
>= len
)
2260 return skb
->data
+ offset
;
2262 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2268 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2270 const unsigned int len
)
2272 memcpy(to
, skb
->data
, len
);
2275 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2276 const int offset
, void *to
,
2277 const unsigned int len
)
2279 memcpy(to
, skb
->data
+ offset
, len
);
2282 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2284 const unsigned int len
)
2286 memcpy(skb
->data
, from
, len
);
2289 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2292 const unsigned int len
)
2294 memcpy(skb
->data
+ offset
, from
, len
);
2297 extern void skb_init(void);
2299 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2305 * skb_get_timestamp - get timestamp from a skb
2306 * @skb: skb to get stamp from
2307 * @stamp: pointer to struct timeval to store stamp in
2309 * Timestamps are stored in the skb as offsets to a base timestamp.
2310 * This function converts the offset back to a struct timeval and stores
2313 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2314 struct timeval
*stamp
)
2316 *stamp
= ktime_to_timeval(skb
->tstamp
);
2319 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2320 struct timespec
*stamp
)
2322 *stamp
= ktime_to_timespec(skb
->tstamp
);
2325 static inline void __net_timestamp(struct sk_buff
*skb
)
2327 skb
->tstamp
= ktime_get_real();
2330 static inline ktime_t
net_timedelta(ktime_t t
)
2332 return ktime_sub(ktime_get_real(), t
);
2335 static inline ktime_t
net_invalid_timestamp(void)
2337 return ktime_set(0, 0);
2340 extern void skb_timestamping_init(void);
2342 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2344 extern void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2345 extern bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2347 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2349 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2353 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2358 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2361 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2363 * PHY drivers may accept clones of transmitted packets for
2364 * timestamping via their phy_driver.txtstamp method. These drivers
2365 * must call this function to return the skb back to the stack, with
2366 * or without a timestamp.
2368 * @skb: clone of the the original outgoing packet
2369 * @hwtstamps: hardware time stamps, may be NULL if not available
2372 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2373 struct skb_shared_hwtstamps
*hwtstamps
);
2376 * skb_tstamp_tx - queue clone of skb with send time stamps
2377 * @orig_skb: the original outgoing packet
2378 * @hwtstamps: hardware time stamps, may be NULL if not available
2380 * If the skb has a socket associated, then this function clones the
2381 * skb (thus sharing the actual data and optional structures), stores
2382 * the optional hardware time stamping information (if non NULL) or
2383 * generates a software time stamp (otherwise), then queues the clone
2384 * to the error queue of the socket. Errors are silently ignored.
2386 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2387 struct skb_shared_hwtstamps
*hwtstamps
);
2389 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2391 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2392 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2393 skb_tstamp_tx(skb
, NULL
);
2397 * skb_tx_timestamp() - Driver hook for transmit timestamping
2399 * Ethernet MAC Drivers should call this function in their hard_xmit()
2400 * function immediately before giving the sk_buff to the MAC hardware.
2402 * @skb: A socket buffer.
2404 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2406 skb_clone_tx_timestamp(skb
);
2407 sw_tx_timestamp(skb
);
2411 * skb_complete_wifi_ack - deliver skb with wifi status
2413 * @skb: the original outgoing packet
2414 * @acked: ack status
2417 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2419 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2420 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2422 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2424 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
2428 * skb_checksum_complete - Calculate checksum of an entire packet
2429 * @skb: packet to process
2431 * This function calculates the checksum over the entire packet plus
2432 * the value of skb->csum. The latter can be used to supply the
2433 * checksum of a pseudo header as used by TCP/UDP. It returns the
2436 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2437 * this function can be used to verify that checksum on received
2438 * packets. In that case the function should return zero if the
2439 * checksum is correct. In particular, this function will return zero
2440 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2441 * hardware has already verified the correctness of the checksum.
2443 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2445 return skb_csum_unnecessary(skb
) ?
2446 0 : __skb_checksum_complete(skb
);
2449 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2450 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2451 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2453 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2454 nf_conntrack_destroy(nfct
);
2456 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2459 atomic_inc(&nfct
->use
);
2462 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2463 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
2466 atomic_inc(&skb
->users
);
2468 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
2474 #ifdef CONFIG_BRIDGE_NETFILTER
2475 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2477 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2480 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2483 atomic_inc(&nf_bridge
->use
);
2485 #endif /* CONFIG_BRIDGE_NETFILTER */
2486 static inline void nf_reset(struct sk_buff
*skb
)
2488 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2489 nf_conntrack_put(skb
->nfct
);
2492 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2493 nf_conntrack_put_reasm(skb
->nfct_reasm
);
2494 skb
->nfct_reasm
= NULL
;
2496 #ifdef CONFIG_BRIDGE_NETFILTER
2497 nf_bridge_put(skb
->nf_bridge
);
2498 skb
->nf_bridge
= NULL
;
2502 /* Note: This doesn't put any conntrack and bridge info in dst. */
2503 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2505 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2506 dst
->nfct
= src
->nfct
;
2507 nf_conntrack_get(src
->nfct
);
2508 dst
->nfctinfo
= src
->nfctinfo
;
2510 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2511 dst
->nfct_reasm
= src
->nfct_reasm
;
2512 nf_conntrack_get_reasm(src
->nfct_reasm
);
2514 #ifdef CONFIG_BRIDGE_NETFILTER
2515 dst
->nf_bridge
= src
->nf_bridge
;
2516 nf_bridge_get(src
->nf_bridge
);
2520 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2522 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2523 nf_conntrack_put(dst
->nfct
);
2525 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2526 nf_conntrack_put_reasm(dst
->nfct_reasm
);
2528 #ifdef CONFIG_BRIDGE_NETFILTER
2529 nf_bridge_put(dst
->nf_bridge
);
2531 __nf_copy(dst
, src
);
2534 #ifdef CONFIG_NETWORK_SECMARK
2535 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2537 to
->secmark
= from
->secmark
;
2540 static inline void skb_init_secmark(struct sk_buff
*skb
)
2545 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2548 static inline void skb_init_secmark(struct sk_buff
*skb
)
2552 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2554 skb
->queue_mapping
= queue_mapping
;
2557 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2559 return skb
->queue_mapping
;
2562 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2564 to
->queue_mapping
= from
->queue_mapping
;
2567 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2569 skb
->queue_mapping
= rx_queue
+ 1;
2572 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2574 return skb
->queue_mapping
- 1;
2577 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2579 return skb
->queue_mapping
!= 0;
2582 extern u16
__skb_tx_hash(const struct net_device
*dev
,
2583 const struct sk_buff
*skb
,
2584 unsigned int num_tx_queues
);
2587 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2592 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2598 static inline bool skb_is_gso(const struct sk_buff
*skb
)
2600 return skb_shinfo(skb
)->gso_size
;
2603 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
2605 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2608 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2610 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2612 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2613 * wanted then gso_type will be set. */
2614 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2616 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
2617 unlikely(shinfo
->gso_type
== 0)) {
2618 __skb_warn_lro_forwarding(skb
);
2624 static inline void skb_forward_csum(struct sk_buff
*skb
)
2626 /* Unfortunately we don't support this one. Any brave souls? */
2627 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2628 skb
->ip_summed
= CHECKSUM_NONE
;
2632 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2633 * @skb: skb to check
2635 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2636 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2637 * use this helper, to document places where we make this assertion.
2639 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
2642 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
2646 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2648 static inline bool skb_is_recycleable(const struct sk_buff
*skb
, int skb_size
)
2650 if (irqs_disabled())
2653 if (skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)
2656 if (skb_is_nonlinear(skb
) || skb
->fclone
!= SKB_FCLONE_UNAVAILABLE
)
2659 skb_size
= SKB_DATA_ALIGN(skb_size
+ NET_SKB_PAD
);
2660 if (skb_end_offset(skb
) < skb_size
)
2663 if (skb_shared(skb
) || skb_cloned(skb
))
2670 * skb_head_is_locked - Determine if the skb->head is locked down
2671 * @skb: skb to check
2673 * The head on skbs build around a head frag can be removed if they are
2674 * not cloned. This function returns true if the skb head is locked down
2675 * due to either being allocated via kmalloc, or by being a clone with
2676 * multiple references to the head.
2678 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
2680 return !skb
->head_frag
|| skb_cloned(skb
);
2682 #endif /* __KERNEL__ */
2683 #endif /* _LINUX_SKBUFF_H */