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 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
593 extern int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
594 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
596 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
598 extern struct sk_buff
*__pskb_copy(struct sk_buff
*skb
,
599 int headroom
, gfp_t gfp_mask
);
601 extern int pskb_expand_head(struct sk_buff
*skb
,
602 int nhead
, int ntail
,
604 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
605 unsigned int headroom
);
606 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
607 int newheadroom
, int newtailroom
,
609 extern int skb_to_sgvec(struct sk_buff
*skb
,
610 struct scatterlist
*sg
, int offset
,
612 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
613 struct sk_buff
**trailer
);
614 extern int skb_pad(struct sk_buff
*skb
, int pad
);
615 #define dev_kfree_skb(a) consume_skb(a)
617 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
618 int getfrag(void *from
, char *to
, int offset
,
619 int len
,int odd
, struct sk_buff
*skb
),
620 void *from
, int length
);
622 struct skb_seq_state
{
626 __u32 stepped_offset
;
627 struct sk_buff
*root_skb
;
628 struct sk_buff
*cur_skb
;
632 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
633 unsigned int from
, unsigned int to
,
634 struct skb_seq_state
*st
);
635 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
636 struct skb_seq_state
*st
);
637 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
639 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
640 unsigned int to
, struct ts_config
*config
,
641 struct ts_state
*state
);
643 extern void __skb_get_rxhash(struct sk_buff
*skb
);
644 static inline __u32
skb_get_rxhash(struct sk_buff
*skb
)
647 __skb_get_rxhash(skb
);
652 #ifdef NET_SKBUFF_DATA_USES_OFFSET
653 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
655 return skb
->head
+ skb
->end
;
658 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
663 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
668 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
670 return skb
->end
- skb
->head
;
675 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
677 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
679 return &skb_shinfo(skb
)->hwtstamps
;
683 * skb_queue_empty - check if a queue is empty
686 * Returns true if the queue is empty, false otherwise.
688 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
690 return list
->next
== (struct sk_buff
*)list
;
694 * skb_queue_is_last - check if skb is the last entry in the queue
698 * Returns true if @skb is the last buffer on the list.
700 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
701 const struct sk_buff
*skb
)
703 return skb
->next
== (struct sk_buff
*)list
;
707 * skb_queue_is_first - check if skb is the first entry in the queue
711 * Returns true if @skb is the first buffer on the list.
713 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
714 const struct sk_buff
*skb
)
716 return skb
->prev
== (struct sk_buff
*)list
;
720 * skb_queue_next - return the next packet in the queue
722 * @skb: current buffer
724 * Return the next packet in @list after @skb. It is only valid to
725 * call this if skb_queue_is_last() evaluates to false.
727 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
728 const struct sk_buff
*skb
)
730 /* This BUG_ON may seem severe, but if we just return then we
731 * are going to dereference garbage.
733 BUG_ON(skb_queue_is_last(list
, skb
));
738 * skb_queue_prev - return the prev packet in the queue
740 * @skb: current buffer
742 * Return the prev packet in @list before @skb. It is only valid to
743 * call this if skb_queue_is_first() evaluates to false.
745 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
746 const struct sk_buff
*skb
)
748 /* This BUG_ON may seem severe, but if we just return then we
749 * are going to dereference garbage.
751 BUG_ON(skb_queue_is_first(list
, skb
));
756 * skb_get - reference buffer
757 * @skb: buffer to reference
759 * Makes another reference to a socket buffer and returns a pointer
762 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
764 atomic_inc(&skb
->users
);
769 * If users == 1, we are the only owner and are can avoid redundant
774 * skb_cloned - is the buffer a clone
775 * @skb: buffer to check
777 * Returns true if the buffer was generated with skb_clone() and is
778 * one of multiple shared copies of the buffer. Cloned buffers are
779 * shared data so must not be written to under normal circumstances.
781 static inline int skb_cloned(const struct sk_buff
*skb
)
783 return skb
->cloned
&&
784 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
788 * skb_header_cloned - is the header a clone
789 * @skb: buffer to check
791 * Returns true if modifying the header part of the buffer requires
792 * the data to be copied.
794 static inline int skb_header_cloned(const struct sk_buff
*skb
)
801 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
802 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
807 * skb_header_release - release reference to header
808 * @skb: buffer to operate on
810 * Drop a reference to the header part of the buffer. This is done
811 * by acquiring a payload reference. You must not read from the header
812 * part of skb->data after this.
814 static inline void skb_header_release(struct sk_buff
*skb
)
818 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
822 * skb_shared - is the buffer shared
823 * @skb: buffer to check
825 * Returns true if more than one person has a reference to this
828 static inline int skb_shared(const struct sk_buff
*skb
)
830 return atomic_read(&skb
->users
) != 1;
834 * skb_share_check - check if buffer is shared and if so clone it
835 * @skb: buffer to check
836 * @pri: priority for memory allocation
838 * If the buffer is shared the buffer is cloned and the old copy
839 * drops a reference. A new clone with a single reference is returned.
840 * If the buffer is not shared the original buffer is returned. When
841 * being called from interrupt status or with spinlocks held pri must
844 * NULL is returned on a memory allocation failure.
846 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
848 might_sleep_if(pri
& __GFP_WAIT
);
849 if (skb_shared(skb
)) {
850 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
862 * Copy shared buffers into a new sk_buff. We effectively do COW on
863 * packets to handle cases where we have a local reader and forward
864 * and a couple of other messy ones. The normal one is tcpdumping
865 * a packet thats being forwarded.
869 * skb_unshare - make a copy of a shared buffer
870 * @skb: buffer to check
871 * @pri: priority for memory allocation
873 * If the socket buffer is a clone then this function creates a new
874 * copy of the data, drops a reference count on the old copy and returns
875 * the new copy with the reference count at 1. If the buffer is not a clone
876 * the original buffer is returned. When called with a spinlock held or
877 * from interrupt state @pri must be %GFP_ATOMIC
879 * %NULL is returned on a memory allocation failure.
881 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
884 might_sleep_if(pri
& __GFP_WAIT
);
885 if (skb_cloned(skb
)) {
886 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
887 kfree_skb(skb
); /* Free our shared copy */
894 * skb_peek - peek at the head of an &sk_buff_head
895 * @list_: list to peek at
897 * Peek an &sk_buff. Unlike most other operations you _MUST_
898 * be careful with this one. A peek leaves the buffer on the
899 * list and someone else may run off with it. You must hold
900 * the appropriate locks or have a private queue to do this.
902 * Returns %NULL for an empty list or a pointer to the head element.
903 * The reference count is not incremented and the reference is therefore
904 * volatile. Use with caution.
906 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
908 struct sk_buff
*skb
= list_
->next
;
910 if (skb
== (struct sk_buff
*)list_
)
916 * skb_peek_next - peek skb following the given one from a queue
917 * @skb: skb to start from
918 * @list_: list to peek at
920 * Returns %NULL when the end of the list is met or a pointer to the
921 * next element. The reference count is not incremented and the
922 * reference is therefore volatile. Use with caution.
924 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
925 const struct sk_buff_head
*list_
)
927 struct sk_buff
*next
= skb
->next
;
929 if (next
== (struct sk_buff
*)list_
)
935 * skb_peek_tail - peek at the tail of an &sk_buff_head
936 * @list_: list to peek at
938 * Peek an &sk_buff. Unlike most other operations you _MUST_
939 * be careful with this one. A peek leaves the buffer on the
940 * list and someone else may run off with it. You must hold
941 * the appropriate locks or have a private queue to do this.
943 * Returns %NULL for an empty list or a pointer to the tail element.
944 * The reference count is not incremented and the reference is therefore
945 * volatile. Use with caution.
947 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
949 struct sk_buff
*skb
= list_
->prev
;
951 if (skb
== (struct sk_buff
*)list_
)
958 * skb_queue_len - get queue length
959 * @list_: list to measure
961 * Return the length of an &sk_buff queue.
963 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
969 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
970 * @list: queue to initialize
972 * This initializes only the list and queue length aspects of
973 * an sk_buff_head object. This allows to initialize the list
974 * aspects of an sk_buff_head without reinitializing things like
975 * the spinlock. It can also be used for on-stack sk_buff_head
976 * objects where the spinlock is known to not be used.
978 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
980 list
->prev
= list
->next
= (struct sk_buff
*)list
;
985 * This function creates a split out lock class for each invocation;
986 * this is needed for now since a whole lot of users of the skb-queue
987 * infrastructure in drivers have different locking usage (in hardirq)
988 * than the networking core (in softirq only). In the long run either the
989 * network layer or drivers should need annotation to consolidate the
990 * main types of usage into 3 classes.
992 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
994 spin_lock_init(&list
->lock
);
995 __skb_queue_head_init(list
);
998 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
999 struct lock_class_key
*class)
1001 skb_queue_head_init(list
);
1002 lockdep_set_class(&list
->lock
, class);
1006 * Insert an sk_buff on a list.
1008 * The "__skb_xxxx()" functions are the non-atomic ones that
1009 * can only be called with interrupts disabled.
1011 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
1012 static inline void __skb_insert(struct sk_buff
*newsk
,
1013 struct sk_buff
*prev
, struct sk_buff
*next
,
1014 struct sk_buff_head
*list
)
1018 next
->prev
= prev
->next
= newsk
;
1022 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1023 struct sk_buff
*prev
,
1024 struct sk_buff
*next
)
1026 struct sk_buff
*first
= list
->next
;
1027 struct sk_buff
*last
= list
->prev
;
1037 * skb_queue_splice - join two skb lists, this is designed for stacks
1038 * @list: the new list to add
1039 * @head: the place to add it in the first list
1041 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1042 struct sk_buff_head
*head
)
1044 if (!skb_queue_empty(list
)) {
1045 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1046 head
->qlen
+= list
->qlen
;
1051 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1052 * @list: the new list to add
1053 * @head: the place to add it in the first list
1055 * The list at @list is reinitialised
1057 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1058 struct sk_buff_head
*head
)
1060 if (!skb_queue_empty(list
)) {
1061 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1062 head
->qlen
+= list
->qlen
;
1063 __skb_queue_head_init(list
);
1068 * skb_queue_splice_tail - join two skb lists, each list being a queue
1069 * @list: the new list to add
1070 * @head: the place to add it in the first list
1072 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1073 struct sk_buff_head
*head
)
1075 if (!skb_queue_empty(list
)) {
1076 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1077 head
->qlen
+= list
->qlen
;
1082 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1083 * @list: the new list to add
1084 * @head: the place to add it in the first list
1086 * Each of the lists is a queue.
1087 * The list at @list is reinitialised
1089 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1090 struct sk_buff_head
*head
)
1092 if (!skb_queue_empty(list
)) {
1093 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1094 head
->qlen
+= list
->qlen
;
1095 __skb_queue_head_init(list
);
1100 * __skb_queue_after - queue a buffer at the list head
1101 * @list: list to use
1102 * @prev: place after this buffer
1103 * @newsk: buffer to queue
1105 * Queue a buffer int the middle of a list. This function takes no locks
1106 * and you must therefore hold required locks before calling it.
1108 * A buffer cannot be placed on two lists at the same time.
1110 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1111 struct sk_buff
*prev
,
1112 struct sk_buff
*newsk
)
1114 __skb_insert(newsk
, prev
, prev
->next
, list
);
1117 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1118 struct sk_buff_head
*list
);
1120 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1121 struct sk_buff
*next
,
1122 struct sk_buff
*newsk
)
1124 __skb_insert(newsk
, next
->prev
, next
, list
);
1128 * __skb_queue_head - queue a buffer at the list head
1129 * @list: list to use
1130 * @newsk: buffer to queue
1132 * Queue a buffer at the start of a list. This function takes no locks
1133 * and you must therefore hold required locks before calling it.
1135 * A buffer cannot be placed on two lists at the same time.
1137 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1138 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1139 struct sk_buff
*newsk
)
1141 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1145 * __skb_queue_tail - queue a buffer at the list tail
1146 * @list: list to use
1147 * @newsk: buffer to queue
1149 * Queue a buffer at the end of a list. This function takes no locks
1150 * and you must therefore hold required locks before calling it.
1152 * A buffer cannot be placed on two lists at the same time.
1154 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1155 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1156 struct sk_buff
*newsk
)
1158 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1162 * remove sk_buff from list. _Must_ be called atomically, and with
1165 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1166 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1168 struct sk_buff
*next
, *prev
;
1173 skb
->next
= skb
->prev
= NULL
;
1179 * __skb_dequeue - remove from the head of the queue
1180 * @list: list to dequeue from
1182 * Remove the head of the list. This function does not take any locks
1183 * so must be used with appropriate locks held only. The head item is
1184 * returned or %NULL if the list is empty.
1186 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1187 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1189 struct sk_buff
*skb
= skb_peek(list
);
1191 __skb_unlink(skb
, list
);
1196 * __skb_dequeue_tail - remove from the tail of the queue
1197 * @list: list to dequeue from
1199 * Remove the tail of the list. This function does not take any locks
1200 * so must be used with appropriate locks held only. The tail item is
1201 * returned or %NULL if the list is empty.
1203 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1204 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1206 struct sk_buff
*skb
= skb_peek_tail(list
);
1208 __skb_unlink(skb
, list
);
1213 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1215 return skb
->data_len
;
1218 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1220 return skb
->len
- skb
->data_len
;
1223 static inline int skb_pagelen(const struct sk_buff
*skb
)
1227 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1228 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1229 return len
+ skb_headlen(skb
);
1233 * __skb_fill_page_desc - initialise a paged fragment in an skb
1234 * @skb: buffer containing fragment to be initialised
1235 * @i: paged fragment index to initialise
1236 * @page: the page to use for this fragment
1237 * @off: the offset to the data with @page
1238 * @size: the length of the data
1240 * Initialises the @i'th fragment of @skb to point to &size bytes at
1241 * offset @off within @page.
1243 * Does not take any additional reference on the fragment.
1245 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1246 struct page
*page
, int off
, int size
)
1248 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1251 * Propagate page->pfmemalloc to the skb if we can. The problem is
1252 * that not all callers have unique ownership of the page. If
1253 * pfmemalloc is set, we check the mapping as a mapping implies
1254 * page->index is set (index and pfmemalloc share space).
1255 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1256 * do not lose pfmemalloc information as the pages would not be
1257 * allocated using __GFP_MEMALLOC.
1259 if (page
->pfmemalloc
&& !page
->mapping
)
1260 skb
->pfmemalloc
= true;
1261 frag
->page
.p
= page
;
1262 frag
->page_offset
= off
;
1263 skb_frag_size_set(frag
, size
);
1267 * skb_fill_page_desc - initialise a paged fragment in an skb
1268 * @skb: buffer containing fragment to be initialised
1269 * @i: paged fragment index to initialise
1270 * @page: the page to use for this fragment
1271 * @off: the offset to the data with @page
1272 * @size: the length of the data
1274 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1275 * @skb to point to &size bytes at offset @off within @page. In
1276 * addition updates @skb such that @i is the last fragment.
1278 * Does not take any additional reference on the fragment.
1280 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1281 struct page
*page
, int off
, int size
)
1283 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1284 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1287 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1288 int off
, int size
, unsigned int truesize
);
1290 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1291 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1292 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1294 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1295 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1297 return skb
->head
+ skb
->tail
;
1300 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1302 skb
->tail
= skb
->data
- skb
->head
;
1305 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1307 skb_reset_tail_pointer(skb
);
1308 skb
->tail
+= offset
;
1310 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1311 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1316 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1318 skb
->tail
= skb
->data
;
1321 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1323 skb
->tail
= skb
->data
+ offset
;
1326 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1329 * Add data to an sk_buff
1331 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1332 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1334 unsigned char *tmp
= skb_tail_pointer(skb
);
1335 SKB_LINEAR_ASSERT(skb
);
1341 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1342 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1349 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1350 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1353 BUG_ON(skb
->len
< skb
->data_len
);
1354 return skb
->data
+= len
;
1357 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1359 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1362 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1364 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1366 if (len
> skb_headlen(skb
) &&
1367 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1370 return skb
->data
+= len
;
1373 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1375 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1378 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1380 if (likely(len
<= skb_headlen(skb
)))
1382 if (unlikely(len
> skb
->len
))
1384 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1388 * skb_headroom - bytes at buffer head
1389 * @skb: buffer to check
1391 * Return the number of bytes of free space at the head of an &sk_buff.
1393 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1395 return skb
->data
- skb
->head
;
1399 * skb_tailroom - bytes at buffer end
1400 * @skb: buffer to check
1402 * Return the number of bytes of free space at the tail of an sk_buff
1404 static inline int skb_tailroom(const struct sk_buff
*skb
)
1406 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1410 * skb_availroom - bytes at buffer end
1411 * @skb: buffer to check
1413 * Return the number of bytes of free space at the tail of an sk_buff
1414 * allocated by sk_stream_alloc()
1416 static inline int skb_availroom(const struct sk_buff
*skb
)
1418 return skb_is_nonlinear(skb
) ? 0 : skb
->avail_size
- skb
->len
;
1422 * skb_reserve - adjust headroom
1423 * @skb: buffer to alter
1424 * @len: bytes to move
1426 * Increase the headroom of an empty &sk_buff by reducing the tail
1427 * room. This is only allowed for an empty buffer.
1429 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1435 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1437 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1440 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1441 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1443 return skb
->head
+ skb
->transport_header
;
1446 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1448 skb
->transport_header
= skb
->data
- skb
->head
;
1451 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1454 skb_reset_transport_header(skb
);
1455 skb
->transport_header
+= offset
;
1458 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1460 return skb
->head
+ skb
->network_header
;
1463 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1465 skb
->network_header
= skb
->data
- skb
->head
;
1468 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1470 skb_reset_network_header(skb
);
1471 skb
->network_header
+= offset
;
1474 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1476 return skb
->head
+ skb
->mac_header
;
1479 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1481 return skb
->mac_header
!= ~0U;
1484 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1486 skb
->mac_header
= skb
->data
- skb
->head
;
1489 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1491 skb_reset_mac_header(skb
);
1492 skb
->mac_header
+= offset
;
1495 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1497 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1499 return skb
->transport_header
;
1502 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1504 skb
->transport_header
= skb
->data
;
1507 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1510 skb
->transport_header
= skb
->data
+ offset
;
1513 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1515 return skb
->network_header
;
1518 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1520 skb
->network_header
= skb
->data
;
1523 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1525 skb
->network_header
= skb
->data
+ offset
;
1528 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1530 return skb
->mac_header
;
1533 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1535 return skb
->mac_header
!= NULL
;
1538 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1540 skb
->mac_header
= skb
->data
;
1543 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1545 skb
->mac_header
= skb
->data
+ offset
;
1547 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1549 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1551 if (skb_mac_header_was_set(skb
)) {
1552 const unsigned char *old_mac
= skb_mac_header(skb
);
1554 skb_set_mac_header(skb
, -skb
->mac_len
);
1555 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1559 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1561 return skb
->csum_start
- skb_headroom(skb
);
1564 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1566 return skb_transport_header(skb
) - skb
->data
;
1569 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1571 return skb
->transport_header
- skb
->network_header
;
1574 static inline int skb_network_offset(const struct sk_buff
*skb
)
1576 return skb_network_header(skb
) - skb
->data
;
1579 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1581 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1585 * CPUs often take a performance hit when accessing unaligned memory
1586 * locations. The actual performance hit varies, it can be small if the
1587 * hardware handles it or large if we have to take an exception and fix it
1590 * Since an ethernet header is 14 bytes network drivers often end up with
1591 * the IP header at an unaligned offset. The IP header can be aligned by
1592 * shifting the start of the packet by 2 bytes. Drivers should do this
1595 * skb_reserve(skb, NET_IP_ALIGN);
1597 * The downside to this alignment of the IP header is that the DMA is now
1598 * unaligned. On some architectures the cost of an unaligned DMA is high
1599 * and this cost outweighs the gains made by aligning the IP header.
1601 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1604 #ifndef NET_IP_ALIGN
1605 #define NET_IP_ALIGN 2
1609 * The networking layer reserves some headroom in skb data (via
1610 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1611 * the header has to grow. In the default case, if the header has to grow
1612 * 32 bytes or less we avoid the reallocation.
1614 * Unfortunately this headroom changes the DMA alignment of the resulting
1615 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1616 * on some architectures. An architecture can override this value,
1617 * perhaps setting it to a cacheline in size (since that will maintain
1618 * cacheline alignment of the DMA). It must be a power of 2.
1620 * Various parts of the networking layer expect at least 32 bytes of
1621 * headroom, you should not reduce this.
1623 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1624 * to reduce average number of cache lines per packet.
1625 * get_rps_cpus() for example only access one 64 bytes aligned block :
1626 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1629 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1632 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1634 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1636 if (unlikely(skb_is_nonlinear(skb
))) {
1641 skb_set_tail_pointer(skb
, len
);
1644 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1646 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1649 return ___pskb_trim(skb
, len
);
1650 __skb_trim(skb
, len
);
1654 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1656 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1660 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1661 * @skb: buffer to alter
1664 * This is identical to pskb_trim except that the caller knows that
1665 * the skb is not cloned so we should never get an error due to out-
1668 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1670 int err
= pskb_trim(skb
, len
);
1675 * skb_orphan - orphan a buffer
1676 * @skb: buffer to orphan
1678 * If a buffer currently has an owner then we call the owner's
1679 * destructor function and make the @skb unowned. The buffer continues
1680 * to exist but is no longer charged to its former owner.
1682 static inline void skb_orphan(struct sk_buff
*skb
)
1684 if (skb
->destructor
)
1685 skb
->destructor(skb
);
1686 skb
->destructor
= NULL
;
1691 * skb_orphan_frags - orphan the frags contained in a buffer
1692 * @skb: buffer to orphan frags from
1693 * @gfp_mask: allocation mask for replacement pages
1695 * For each frag in the SKB which needs a destructor (i.e. has an
1696 * owner) create a copy of that frag and release the original
1697 * page by calling the destructor.
1699 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1701 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1703 return skb_copy_ubufs(skb
, gfp_mask
);
1707 * __skb_queue_purge - empty a list
1708 * @list: list to empty
1710 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1711 * the list and one reference dropped. This function does not take the
1712 * list lock and the caller must hold the relevant locks to use it.
1714 extern void skb_queue_purge(struct sk_buff_head
*list
);
1715 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1717 struct sk_buff
*skb
;
1718 while ((skb
= __skb_dequeue(list
)) != NULL
)
1722 extern void *netdev_alloc_frag(unsigned int fragsz
);
1724 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1725 unsigned int length
,
1729 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1730 * @dev: network device to receive on
1731 * @length: length to allocate
1733 * Allocate a new &sk_buff and assign it a usage count of one. The
1734 * buffer has unspecified headroom built in. Users should allocate
1735 * the headroom they think they need without accounting for the
1736 * built in space. The built in space is used for optimisations.
1738 * %NULL is returned if there is no free memory. Although this function
1739 * allocates memory it can be called from an interrupt.
1741 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1742 unsigned int length
)
1744 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1747 /* legacy helper around __netdev_alloc_skb() */
1748 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1751 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
1754 /* legacy helper around netdev_alloc_skb() */
1755 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1757 return netdev_alloc_skb(NULL
, length
);
1761 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
1762 unsigned int length
, gfp_t gfp
)
1764 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
1766 if (NET_IP_ALIGN
&& skb
)
1767 skb_reserve(skb
, NET_IP_ALIGN
);
1771 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
1772 unsigned int length
)
1774 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
1778 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1779 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1780 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1781 * @order: size of the allocation
1783 * Allocate a new page.
1785 * %NULL is returned if there is no free memory.
1787 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
1788 struct sk_buff
*skb
,
1793 gfp_mask
|= __GFP_COLD
;
1795 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1796 gfp_mask
|= __GFP_MEMALLOC
;
1798 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
1799 if (skb
&& page
&& page
->pfmemalloc
)
1800 skb
->pfmemalloc
= true;
1806 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1807 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1808 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1810 * Allocate a new page.
1812 * %NULL is returned if there is no free memory.
1814 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
1815 struct sk_buff
*skb
)
1817 return __skb_alloc_pages(gfp_mask
, skb
, 0);
1821 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1822 * @page: The page that was allocated from skb_alloc_page
1823 * @skb: The skb that may need pfmemalloc set
1825 static inline void skb_propagate_pfmemalloc(struct page
*page
,
1826 struct sk_buff
*skb
)
1828 if (page
&& page
->pfmemalloc
)
1829 skb
->pfmemalloc
= true;
1833 * skb_frag_page - retrieve the page refered to by a paged fragment
1834 * @frag: the paged fragment
1836 * Returns the &struct page associated with @frag.
1838 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
1840 return frag
->page
.p
;
1844 * __skb_frag_ref - take an addition reference on a paged fragment.
1845 * @frag: the paged fragment
1847 * Takes an additional reference on the paged fragment @frag.
1849 static inline void __skb_frag_ref(skb_frag_t
*frag
)
1851 get_page(skb_frag_page(frag
));
1855 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1857 * @f: the fragment offset.
1859 * Takes an additional reference on the @f'th paged fragment of @skb.
1861 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
1863 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
1867 * __skb_frag_unref - release a reference on a paged fragment.
1868 * @frag: the paged fragment
1870 * Releases a reference on the paged fragment @frag.
1872 static inline void __skb_frag_unref(skb_frag_t
*frag
)
1874 put_page(skb_frag_page(frag
));
1878 * skb_frag_unref - release a reference on a paged fragment of an skb.
1880 * @f: the fragment offset
1882 * Releases a reference on the @f'th paged fragment of @skb.
1884 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
1886 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
1890 * skb_frag_address - gets the address of the data contained in a paged fragment
1891 * @frag: the paged fragment buffer
1893 * Returns the address of the data within @frag. The page must already
1896 static inline void *skb_frag_address(const skb_frag_t
*frag
)
1898 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
1902 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1903 * @frag: the paged fragment buffer
1905 * Returns the address of the data within @frag. Checks that the page
1906 * is mapped and returns %NULL otherwise.
1908 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
1910 void *ptr
= page_address(skb_frag_page(frag
));
1914 return ptr
+ frag
->page_offset
;
1918 * __skb_frag_set_page - sets the page contained in a paged fragment
1919 * @frag: the paged fragment
1920 * @page: the page to set
1922 * Sets the fragment @frag to contain @page.
1924 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
1926 frag
->page
.p
= page
;
1930 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1932 * @f: the fragment offset
1933 * @page: the page to set
1935 * Sets the @f'th fragment of @skb to contain @page.
1937 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
1940 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
1944 * skb_frag_dma_map - maps a paged fragment via the DMA API
1945 * @dev: the device to map the fragment to
1946 * @frag: the paged fragment to map
1947 * @offset: the offset within the fragment (starting at the
1948 * fragment's own offset)
1949 * @size: the number of bytes to map
1950 * @dir: the direction of the mapping (%PCI_DMA_*)
1952 * Maps the page associated with @frag to @device.
1954 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
1955 const skb_frag_t
*frag
,
1956 size_t offset
, size_t size
,
1957 enum dma_data_direction dir
)
1959 return dma_map_page(dev
, skb_frag_page(frag
),
1960 frag
->page_offset
+ offset
, size
, dir
);
1963 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
1966 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
1970 * skb_clone_writable - is the header of a clone writable
1971 * @skb: buffer to check
1972 * @len: length up to which to write
1974 * Returns true if modifying the header part of the cloned buffer
1975 * does not requires the data to be copied.
1977 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
1979 return !skb_header_cloned(skb
) &&
1980 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1983 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1988 if (headroom
> skb_headroom(skb
))
1989 delta
= headroom
- skb_headroom(skb
);
1991 if (delta
|| cloned
)
1992 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1998 * skb_cow - copy header of skb when it is required
1999 * @skb: buffer to cow
2000 * @headroom: needed headroom
2002 * If the skb passed lacks sufficient headroom or its data part
2003 * is shared, data is reallocated. If reallocation fails, an error
2004 * is returned and original skb is not changed.
2006 * The result is skb with writable area skb->head...skb->tail
2007 * and at least @headroom of space at head.
2009 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2011 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2015 * skb_cow_head - skb_cow but only making the head writable
2016 * @skb: buffer to cow
2017 * @headroom: needed headroom
2019 * This function is identical to skb_cow except that we replace the
2020 * skb_cloned check by skb_header_cloned. It should be used when
2021 * you only need to push on some header and do not need to modify
2024 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2026 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2030 * skb_padto - pad an skbuff up to a minimal size
2031 * @skb: buffer to pad
2032 * @len: minimal length
2034 * Pads up a buffer to ensure the trailing bytes exist and are
2035 * blanked. If the buffer already contains sufficient data it
2036 * is untouched. Otherwise it is extended. Returns zero on
2037 * success. The skb is freed on error.
2040 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2042 unsigned int size
= skb
->len
;
2043 if (likely(size
>= len
))
2045 return skb_pad(skb
, len
- size
);
2048 static inline int skb_add_data(struct sk_buff
*skb
,
2049 char __user
*from
, int copy
)
2051 const int off
= skb
->len
;
2053 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2055 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2058 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2061 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2064 __skb_trim(skb
, off
);
2068 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2069 const struct page
*page
, int off
)
2072 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2074 return page
== skb_frag_page(frag
) &&
2075 off
== frag
->page_offset
+ skb_frag_size(frag
);
2080 static inline int __skb_linearize(struct sk_buff
*skb
)
2082 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2086 * skb_linearize - convert paged skb to linear one
2087 * @skb: buffer to linarize
2089 * If there is no free memory -ENOMEM is returned, otherwise zero
2090 * is returned and the old skb data released.
2092 static inline int skb_linearize(struct sk_buff
*skb
)
2094 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2098 * skb_linearize_cow - make sure skb is linear and writable
2099 * @skb: buffer to process
2101 * If there is no free memory -ENOMEM is returned, otherwise zero
2102 * is returned and the old skb data released.
2104 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2106 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2107 __skb_linearize(skb
) : 0;
2111 * skb_postpull_rcsum - update checksum for received skb after pull
2112 * @skb: buffer to update
2113 * @start: start of data before pull
2114 * @len: length of data pulled
2116 * After doing a pull on a received packet, you need to call this to
2117 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2118 * CHECKSUM_NONE so that it can be recomputed from scratch.
2121 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2122 const void *start
, unsigned int len
)
2124 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2125 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2128 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2131 * pskb_trim_rcsum - trim received skb and update checksum
2132 * @skb: buffer to trim
2135 * This is exactly the same as pskb_trim except that it ensures the
2136 * checksum of received packets are still valid after the operation.
2139 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2141 if (likely(len
>= skb
->len
))
2143 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2144 skb
->ip_summed
= CHECKSUM_NONE
;
2145 return __pskb_trim(skb
, len
);
2148 #define skb_queue_walk(queue, skb) \
2149 for (skb = (queue)->next; \
2150 skb != (struct sk_buff *)(queue); \
2153 #define skb_queue_walk_safe(queue, skb, tmp) \
2154 for (skb = (queue)->next, tmp = skb->next; \
2155 skb != (struct sk_buff *)(queue); \
2156 skb = tmp, tmp = skb->next)
2158 #define skb_queue_walk_from(queue, skb) \
2159 for (; skb != (struct sk_buff *)(queue); \
2162 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2163 for (tmp = skb->next; \
2164 skb != (struct sk_buff *)(queue); \
2165 skb = tmp, tmp = skb->next)
2167 #define skb_queue_reverse_walk(queue, skb) \
2168 for (skb = (queue)->prev; \
2169 skb != (struct sk_buff *)(queue); \
2172 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2173 for (skb = (queue)->prev, tmp = skb->prev; \
2174 skb != (struct sk_buff *)(queue); \
2175 skb = tmp, tmp = skb->prev)
2177 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2178 for (tmp = skb->prev; \
2179 skb != (struct sk_buff *)(queue); \
2180 skb = tmp, tmp = skb->prev)
2182 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2184 return skb_shinfo(skb
)->frag_list
!= NULL
;
2187 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2189 skb_shinfo(skb
)->frag_list
= NULL
;
2192 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2194 frag
->next
= skb_shinfo(skb
)->frag_list
;
2195 skb_shinfo(skb
)->frag_list
= frag
;
2198 #define skb_walk_frags(skb, iter) \
2199 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2201 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2202 int *peeked
, int *off
, int *err
);
2203 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2204 int noblock
, int *err
);
2205 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2206 struct poll_table_struct
*wait
);
2207 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
2208 int offset
, struct iovec
*to
,
2210 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
2213 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
2215 const struct iovec
*from
,
2218 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
2220 const struct iovec
*to
,
2223 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2224 extern void skb_free_datagram_locked(struct sock
*sk
,
2225 struct sk_buff
*skb
);
2226 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
2227 unsigned int flags
);
2228 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
2229 int len
, __wsum csum
);
2230 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
2232 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
2233 const void *from
, int len
);
2234 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
2235 int offset
, u8
*to
, int len
,
2237 extern int skb_splice_bits(struct sk_buff
*skb
,
2238 unsigned int offset
,
2239 struct pipe_inode_info
*pipe
,
2241 unsigned int flags
);
2242 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2243 extern void skb_split(struct sk_buff
*skb
,
2244 struct sk_buff
*skb1
, const u32 len
);
2245 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
2248 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
,
2249 netdev_features_t features
);
2251 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2252 int len
, void *buffer
)
2254 int hlen
= skb_headlen(skb
);
2256 if (hlen
- offset
>= len
)
2257 return skb
->data
+ offset
;
2259 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2265 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2267 const unsigned int len
)
2269 memcpy(to
, skb
->data
, len
);
2272 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2273 const int offset
, void *to
,
2274 const unsigned int len
)
2276 memcpy(to
, skb
->data
+ offset
, len
);
2279 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2281 const unsigned int len
)
2283 memcpy(skb
->data
, from
, len
);
2286 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2289 const unsigned int len
)
2291 memcpy(skb
->data
+ offset
, from
, len
);
2294 extern void skb_init(void);
2296 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2302 * skb_get_timestamp - get timestamp from a skb
2303 * @skb: skb to get stamp from
2304 * @stamp: pointer to struct timeval to store stamp in
2306 * Timestamps are stored in the skb as offsets to a base timestamp.
2307 * This function converts the offset back to a struct timeval and stores
2310 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2311 struct timeval
*stamp
)
2313 *stamp
= ktime_to_timeval(skb
->tstamp
);
2316 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2317 struct timespec
*stamp
)
2319 *stamp
= ktime_to_timespec(skb
->tstamp
);
2322 static inline void __net_timestamp(struct sk_buff
*skb
)
2324 skb
->tstamp
= ktime_get_real();
2327 static inline ktime_t
net_timedelta(ktime_t t
)
2329 return ktime_sub(ktime_get_real(), t
);
2332 static inline ktime_t
net_invalid_timestamp(void)
2334 return ktime_set(0, 0);
2337 extern void skb_timestamping_init(void);
2339 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2341 extern void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2342 extern bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2344 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2346 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2350 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2355 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2358 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2360 * PHY drivers may accept clones of transmitted packets for
2361 * timestamping via their phy_driver.txtstamp method. These drivers
2362 * must call this function to return the skb back to the stack, with
2363 * or without a timestamp.
2365 * @skb: clone of the the original outgoing packet
2366 * @hwtstamps: hardware time stamps, may be NULL if not available
2369 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2370 struct skb_shared_hwtstamps
*hwtstamps
);
2373 * skb_tstamp_tx - queue clone of skb with send time stamps
2374 * @orig_skb: the original outgoing packet
2375 * @hwtstamps: hardware time stamps, may be NULL if not available
2377 * If the skb has a socket associated, then this function clones the
2378 * skb (thus sharing the actual data and optional structures), stores
2379 * the optional hardware time stamping information (if non NULL) or
2380 * generates a software time stamp (otherwise), then queues the clone
2381 * to the error queue of the socket. Errors are silently ignored.
2383 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2384 struct skb_shared_hwtstamps
*hwtstamps
);
2386 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2388 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2389 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2390 skb_tstamp_tx(skb
, NULL
);
2394 * skb_tx_timestamp() - Driver hook for transmit timestamping
2396 * Ethernet MAC Drivers should call this function in their hard_xmit()
2397 * function immediately before giving the sk_buff to the MAC hardware.
2399 * @skb: A socket buffer.
2401 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2403 skb_clone_tx_timestamp(skb
);
2404 sw_tx_timestamp(skb
);
2408 * skb_complete_wifi_ack - deliver skb with wifi status
2410 * @skb: the original outgoing packet
2411 * @acked: ack status
2414 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2416 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2417 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2419 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2421 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
2425 * skb_checksum_complete - Calculate checksum of an entire packet
2426 * @skb: packet to process
2428 * This function calculates the checksum over the entire packet plus
2429 * the value of skb->csum. The latter can be used to supply the
2430 * checksum of a pseudo header as used by TCP/UDP. It returns the
2433 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2434 * this function can be used to verify that checksum on received
2435 * packets. In that case the function should return zero if the
2436 * checksum is correct. In particular, this function will return zero
2437 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2438 * hardware has already verified the correctness of the checksum.
2440 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2442 return skb_csum_unnecessary(skb
) ?
2443 0 : __skb_checksum_complete(skb
);
2446 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2447 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2448 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2450 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2451 nf_conntrack_destroy(nfct
);
2453 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2456 atomic_inc(&nfct
->use
);
2459 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2460 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
2463 atomic_inc(&skb
->users
);
2465 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
2471 #ifdef CONFIG_BRIDGE_NETFILTER
2472 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2474 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2477 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2480 atomic_inc(&nf_bridge
->use
);
2482 #endif /* CONFIG_BRIDGE_NETFILTER */
2483 static inline void nf_reset(struct sk_buff
*skb
)
2485 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2486 nf_conntrack_put(skb
->nfct
);
2489 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2490 nf_conntrack_put_reasm(skb
->nfct_reasm
);
2491 skb
->nfct_reasm
= NULL
;
2493 #ifdef CONFIG_BRIDGE_NETFILTER
2494 nf_bridge_put(skb
->nf_bridge
);
2495 skb
->nf_bridge
= NULL
;
2499 /* Note: This doesn't put any conntrack and bridge info in dst. */
2500 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2502 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2503 dst
->nfct
= src
->nfct
;
2504 nf_conntrack_get(src
->nfct
);
2505 dst
->nfctinfo
= src
->nfctinfo
;
2507 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2508 dst
->nfct_reasm
= src
->nfct_reasm
;
2509 nf_conntrack_get_reasm(src
->nfct_reasm
);
2511 #ifdef CONFIG_BRIDGE_NETFILTER
2512 dst
->nf_bridge
= src
->nf_bridge
;
2513 nf_bridge_get(src
->nf_bridge
);
2517 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2519 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2520 nf_conntrack_put(dst
->nfct
);
2522 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2523 nf_conntrack_put_reasm(dst
->nfct_reasm
);
2525 #ifdef CONFIG_BRIDGE_NETFILTER
2526 nf_bridge_put(dst
->nf_bridge
);
2528 __nf_copy(dst
, src
);
2531 #ifdef CONFIG_NETWORK_SECMARK
2532 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2534 to
->secmark
= from
->secmark
;
2537 static inline void skb_init_secmark(struct sk_buff
*skb
)
2542 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2545 static inline void skb_init_secmark(struct sk_buff
*skb
)
2549 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2551 skb
->queue_mapping
= queue_mapping
;
2554 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2556 return skb
->queue_mapping
;
2559 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2561 to
->queue_mapping
= from
->queue_mapping
;
2564 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2566 skb
->queue_mapping
= rx_queue
+ 1;
2569 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2571 return skb
->queue_mapping
- 1;
2574 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2576 return skb
->queue_mapping
!= 0;
2579 extern u16
__skb_tx_hash(const struct net_device
*dev
,
2580 const struct sk_buff
*skb
,
2581 unsigned int num_tx_queues
);
2584 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2589 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2595 static inline bool skb_is_gso(const struct sk_buff
*skb
)
2597 return skb_shinfo(skb
)->gso_size
;
2600 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
2602 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2605 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2607 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2609 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2610 * wanted then gso_type will be set. */
2611 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2613 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
2614 unlikely(shinfo
->gso_type
== 0)) {
2615 __skb_warn_lro_forwarding(skb
);
2621 static inline void skb_forward_csum(struct sk_buff
*skb
)
2623 /* Unfortunately we don't support this one. Any brave souls? */
2624 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2625 skb
->ip_summed
= CHECKSUM_NONE
;
2629 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2630 * @skb: skb to check
2632 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2633 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2634 * use this helper, to document places where we make this assertion.
2636 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
2639 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
2643 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2646 * skb_head_is_locked - Determine if the skb->head is locked down
2647 * @skb: skb to check
2649 * The head on skbs build around a head frag can be removed if they are
2650 * not cloned. This function returns true if the skb head is locked down
2651 * due to either being allocated via kmalloc, or by being a clone with
2652 * multiple references to the head.
2654 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
2656 return !skb
->head_frag
|| skb_cloned(skb
);
2658 #endif /* __KERNEL__ */
2659 #endif /* _LINUX_SKBUFF_H */