2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
24 #include <linux/atomic.h>
25 #include <asm/types.h>
26 #include <linux/spinlock.h>
27 #include <linux/net.h>
28 #include <linux/textsearch.h>
29 #include <net/checksum.h>
30 #include <linux/rcupdate.h>
31 #include <linux/dmaengine.h>
32 #include <linux/hrtimer.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/netdev_features.h>
36 /* Don't change this without changing skb_csum_unnecessary! */
37 #define CHECKSUM_NONE 0
38 #define CHECKSUM_UNNECESSARY 1
39 #define CHECKSUM_COMPLETE 2
40 #define CHECKSUM_PARTIAL 3
42 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
43 ~(SMP_CACHE_BYTES - 1))
44 #define SKB_WITH_OVERHEAD(X) \
45 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
46 #define SKB_MAX_ORDER(X, ORDER) \
47 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
48 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
49 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
51 /* return minimum truesize of one skb containing X bytes of data */
52 #define SKB_TRUESIZE(X) ((X) + \
53 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
54 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
56 /* A. Checksumming of received packets by device.
58 * NONE: device failed to checksum this packet.
59 * skb->csum is undefined.
61 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
62 * skb->csum is undefined.
63 * It is bad option, but, unfortunately, many of vendors do this.
64 * Apparently with secret goal to sell you new device, when you
65 * will add new protocol to your host. F.e. IPv6. 8)
67 * COMPLETE: the most generic way. Device supplied checksum of _all_
68 * the packet as seen by netif_rx in skb->csum.
69 * NOTE: Even if device supports only some protocols, but
70 * is able to produce some skb->csum, it MUST use COMPLETE,
73 * PARTIAL: identical to the case for output below. This may occur
74 * on a packet received directly from another Linux OS, e.g.,
75 * a virtualised Linux kernel on the same host. The packet can
76 * be treated in the same way as UNNECESSARY except that on
77 * output (i.e., forwarding) the checksum must be filled in
78 * by the OS or the hardware.
80 * B. Checksumming on output.
82 * NONE: skb is checksummed by protocol or csum is not required.
84 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
85 * from skb->csum_start to the end and to record the checksum
86 * at skb->csum_start + skb->csum_offset.
88 * Device must show its capabilities in dev->features, set
89 * at device setup time.
90 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
92 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
93 * TCP/UDP over IPv4. Sigh. Vendors like this
94 * way by an unknown reason. Though, see comment above
95 * about CHECKSUM_UNNECESSARY. 8)
96 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
98 * UNNECESSARY: device will do per protocol specific csum. Protocol drivers
99 * that do not want net to perform the checksum calculation should use
100 * this flag in their outgoing skbs.
101 * NETIF_F_FCOE_CRC this indicates the device can do FCoE FC CRC
102 * offload. Correspondingly, the FCoE protocol driver
103 * stack should use CHECKSUM_UNNECESSARY.
105 * Any questions? No questions, good. --ANK
110 struct pipe_inode_info
;
112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
113 struct nf_conntrack
{
118 #ifdef CONFIG_BRIDGE_NETFILTER
119 struct nf_bridge_info
{
122 struct net_device
*physindev
;
123 struct net_device
*physoutdev
;
124 unsigned long data
[32 / sizeof(unsigned long)];
128 struct sk_buff_head
{
129 /* These two members must be first. */
130 struct sk_buff
*next
;
131 struct sk_buff
*prev
;
139 /* To allow 64K frame to be packed as single skb without frag_list we
140 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
141 * buffers which do not start on a page boundary.
143 * Since GRO uses frags we allocate at least 16 regardless of page
146 #if (65536/PAGE_SIZE + 1) < 16
147 #define MAX_SKB_FRAGS 16UL
149 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
152 typedef struct skb_frag_struct skb_frag_t
;
154 struct skb_frag_struct
{
158 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
167 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
172 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
177 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
182 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
187 #define HAVE_HW_TIME_STAMP
190 * struct skb_shared_hwtstamps - hardware time stamps
191 * @hwtstamp: hardware time stamp transformed into duration
192 * since arbitrary point in time
193 * @syststamp: hwtstamp transformed to system time base
195 * Software time stamps generated by ktime_get_real() are stored in
196 * skb->tstamp. The relation between the different kinds of time
197 * stamps is as follows:
199 * syststamp and tstamp can be compared against each other in
200 * arbitrary combinations. The accuracy of a
201 * syststamp/tstamp/"syststamp from other device" comparison is
202 * limited by the accuracy of the transformation into system time
203 * base. This depends on the device driver and its underlying
206 * hwtstamps can only be compared against other hwtstamps from
209 * This structure is attached to packets as part of the
210 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
212 struct skb_shared_hwtstamps
{
217 /* Definitions for tx_flags in struct skb_shared_info */
219 /* generate hardware time stamp */
220 SKBTX_HW_TSTAMP
= 1 << 0,
222 /* generate software time stamp */
223 SKBTX_SW_TSTAMP
= 1 << 1,
225 /* device driver is going to provide hardware time stamp */
226 SKBTX_IN_PROGRESS
= 1 << 2,
228 /* device driver supports TX zero-copy buffers */
229 SKBTX_DEV_ZEROCOPY
= 1 << 3,
231 /* generate wifi status information (where possible) */
232 SKBTX_WIFI_STATUS
= 1 << 4,
236 * The callback notifies userspace to release buffers when skb DMA is done in
237 * lower device, the skb last reference should be 0 when calling this.
238 * The zerocopy_success argument is true if zero copy transmit occurred,
239 * false on data copy or out of memory error caused by data copy attempt.
240 * The ctx field is used to track device context.
241 * The desc field is used to track userspace buffer index.
244 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
249 /* This data is invariant across clones and lives at
250 * the end of the header data, ie. at skb->end.
252 struct skb_shared_info
{
253 unsigned char nr_frags
;
255 unsigned short gso_size
;
256 /* Warning: this field is not always filled in (UFO)! */
257 unsigned short gso_segs
;
258 unsigned short gso_type
;
259 struct sk_buff
*frag_list
;
260 struct skb_shared_hwtstamps hwtstamps
;
264 * Warning : all fields before dataref are cleared in __alloc_skb()
268 /* Intermediate layers must ensure that destructor_arg
269 * remains valid until skb destructor */
270 void * destructor_arg
;
272 /* must be last field, see pskb_expand_head() */
273 skb_frag_t frags
[MAX_SKB_FRAGS
];
276 /* We divide dataref into two halves. The higher 16 bits hold references
277 * to the payload part of skb->data. The lower 16 bits hold references to
278 * the entire skb->data. A clone of a headerless skb holds the length of
279 * the header in skb->hdr_len.
281 * All users must obey the rule that the skb->data reference count must be
282 * greater than or equal to the payload reference count.
284 * Holding a reference to the payload part means that the user does not
285 * care about modifications to the header part of skb->data.
287 #define SKB_DATAREF_SHIFT 16
288 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
292 SKB_FCLONE_UNAVAILABLE
,
298 SKB_GSO_TCPV4
= 1 << 0,
299 SKB_GSO_UDP
= 1 << 1,
301 /* This indicates the skb is from an untrusted source. */
302 SKB_GSO_DODGY
= 1 << 2,
304 /* This indicates the tcp segment has CWR set. */
305 SKB_GSO_TCP_ECN
= 1 << 3,
307 SKB_GSO_TCPV6
= 1 << 4,
309 SKB_GSO_FCOE
= 1 << 5,
311 /* This indicates at least one fragment might be overwritten
312 * (as in vmsplice(), sendfile() ...)
313 * If we need to compute a TX checksum, we'll need to copy
314 * all frags to avoid possible bad checksum
316 SKB_GSO_SHARED_FRAG
= 1 << 6,
319 #if BITS_PER_LONG > 32
320 #define NET_SKBUFF_DATA_USES_OFFSET 1
323 #ifdef NET_SKBUFF_DATA_USES_OFFSET
324 typedef unsigned int sk_buff_data_t
;
326 typedef unsigned char *sk_buff_data_t
;
329 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
330 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
331 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
335 * struct sk_buff - socket buffer
336 * @next: Next buffer in list
337 * @prev: Previous buffer in list
338 * @tstamp: Time we arrived
339 * @sk: Socket we are owned by
340 * @dev: Device we arrived on/are leaving by
341 * @cb: Control buffer. Free for use by every layer. Put private vars here
342 * @_skb_refdst: destination entry (with norefcount bit)
343 * @sp: the security path, used for xfrm
344 * @len: Length of actual data
345 * @data_len: Data length
346 * @mac_len: Length of link layer header
347 * @hdr_len: writable header length of cloned skb
348 * @csum: Checksum (must include start/offset pair)
349 * @csum_start: Offset from skb->head where checksumming should start
350 * @csum_offset: Offset from csum_start where checksum should be stored
351 * @priority: Packet queueing priority
352 * @local_df: allow local fragmentation
353 * @cloned: Head may be cloned (check refcnt to be sure)
354 * @ip_summed: Driver fed us an IP checksum
355 * @nohdr: Payload reference only, must not modify header
356 * @nfctinfo: Relationship of this skb to the connection
357 * @pkt_type: Packet class
358 * @fclone: skbuff clone status
359 * @ipvs_property: skbuff is owned by ipvs
360 * @peeked: this packet has been seen already, so stats have been
361 * done for it, don't do them again
362 * @nf_trace: netfilter packet trace flag
363 * @protocol: Packet protocol from driver
364 * @destructor: Destruct function
365 * @nfct: Associated connection, if any
366 * @nfct_reasm: netfilter conntrack re-assembly pointer
367 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
368 * @skb_iif: ifindex of device we arrived on
369 * @tc_index: Traffic control index
370 * @tc_verd: traffic control verdict
371 * @rxhash: the packet hash computed on receive
372 * @queue_mapping: Queue mapping for multiqueue devices
373 * @ndisc_nodetype: router type (from link layer)
374 * @ooo_okay: allow the mapping of a socket to a queue to be changed
375 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
377 * @wifi_acked_valid: wifi_acked was set
378 * @wifi_acked: whether frame was acked on wifi or not
379 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
380 * @dma_cookie: a cookie to one of several possible DMA operations
381 * done by skb DMA functions
382 * @secmark: security marking
383 * @mark: Generic packet mark
384 * @dropcount: total number of sk_receive_queue overflows
385 * @vlan_tci: vlan tag control information
386 * @inner_transport_header: Inner transport layer header (encapsulation)
387 * @inner_network_header: Network layer header (encapsulation)
388 * @transport_header: Transport layer header
389 * @network_header: Network layer header
390 * @mac_header: Link layer header
391 * @tail: Tail pointer
393 * @head: Head of buffer
394 * @data: Data head pointer
395 * @truesize: Buffer size
396 * @users: User count - see {datagram,tcp}.c
400 /* These two members must be first. */
401 struct sk_buff
*next
;
402 struct sk_buff
*prev
;
407 struct net_device
*dev
;
410 * This is the control buffer. It is free to use for every
411 * layer. Please put your private variables there. If you
412 * want to keep them across layers you have to do a skb_clone()
413 * first. This is owned by whoever has the skb queued ATM.
415 char cb
[48] __aligned(8);
417 unsigned long _skb_refdst
;
433 kmemcheck_bitfield_begin(flags1
);
444 kmemcheck_bitfield_end(flags1
);
447 void (*destructor
)(struct sk_buff
*skb
);
448 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
449 struct nf_conntrack
*nfct
;
451 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
452 struct sk_buff
*nfct_reasm
;
454 #ifdef CONFIG_BRIDGE_NETFILTER
455 struct nf_bridge_info
*nf_bridge
;
464 #ifdef CONFIG_NET_SCHED
465 __u16 tc_index
; /* traffic control index */
466 #ifdef CONFIG_NET_CLS_ACT
467 __u16 tc_verd
; /* traffic control verdict */
472 kmemcheck_bitfield_begin(flags2
);
473 #ifdef CONFIG_IPV6_NDISC_NODETYPE
474 __u8 ndisc_nodetype
:2;
479 __u8 wifi_acked_valid
:1;
483 /* Encapsulation protocol and NIC drivers should use
484 * this flag to indicate to each other if the skb contains
485 * encapsulated packet or not and maybe use the inner packet
488 __u8 encapsulation
:1;
489 /* 7/9 bit hole (depending on ndisc_nodetype presence) */
490 kmemcheck_bitfield_end(flags2
);
492 #ifdef CONFIG_NET_DMA
493 dma_cookie_t dma_cookie
;
495 #ifdef CONFIG_NETWORK_SECMARK
504 sk_buff_data_t inner_transport_header
;
505 sk_buff_data_t inner_network_header
;
506 sk_buff_data_t transport_header
;
507 sk_buff_data_t network_header
;
508 sk_buff_data_t mac_header
;
509 /* These elements must be at the end, see alloc_skb() for details. */
514 unsigned int truesize
;
520 * Handling routines are only of interest to the kernel
522 #include <linux/slab.h>
525 #define SKB_ALLOC_FCLONE 0x01
526 #define SKB_ALLOC_RX 0x02
528 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
529 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
531 return unlikely(skb
->pfmemalloc
);
535 * skb might have a dst pointer attached, refcounted or not.
536 * _skb_refdst low order bit is set if refcount was _not_ taken
538 #define SKB_DST_NOREF 1UL
539 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
542 * skb_dst - returns skb dst_entry
545 * Returns skb dst_entry, regardless of reference taken or not.
547 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
549 /* If refdst was not refcounted, check we still are in a
550 * rcu_read_lock section
552 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
553 !rcu_read_lock_held() &&
554 !rcu_read_lock_bh_held());
555 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
559 * skb_dst_set - sets skb dst
563 * Sets skb dst, assuming a reference was taken on dst and should
564 * be released by skb_dst_drop()
566 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
568 skb
->_skb_refdst
= (unsigned long)dst
;
571 extern void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
);
574 * skb_dst_is_noref - Test if skb dst isn't refcounted
577 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
579 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
582 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
584 return (struct rtable
*)skb_dst(skb
);
587 extern void kfree_skb(struct sk_buff
*skb
);
588 extern void skb_tx_error(struct sk_buff
*skb
);
589 extern void consume_skb(struct sk_buff
*skb
);
590 extern void __kfree_skb(struct sk_buff
*skb
);
591 extern struct kmem_cache
*skbuff_head_cache
;
593 extern void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
594 extern bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
595 bool *fragstolen
, int *delta_truesize
);
597 extern struct sk_buff
*__alloc_skb(unsigned int size
,
598 gfp_t priority
, int flags
, int node
);
599 extern struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
600 static inline struct sk_buff
*alloc_skb(unsigned int size
,
603 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
606 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
609 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
612 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
613 extern int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
614 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
616 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
618 extern struct sk_buff
*__pskb_copy(struct sk_buff
*skb
,
619 int headroom
, gfp_t gfp_mask
);
621 extern int pskb_expand_head(struct sk_buff
*skb
,
622 int nhead
, int ntail
,
624 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
625 unsigned int headroom
);
626 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
627 int newheadroom
, int newtailroom
,
629 extern int skb_to_sgvec(struct sk_buff
*skb
,
630 struct scatterlist
*sg
, int offset
,
632 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
633 struct sk_buff
**trailer
);
634 extern int skb_pad(struct sk_buff
*skb
, int pad
);
635 #define dev_kfree_skb(a) consume_skb(a)
637 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
638 int getfrag(void *from
, char *to
, int offset
,
639 int len
,int odd
, struct sk_buff
*skb
),
640 void *from
, int length
);
642 struct skb_seq_state
{
646 __u32 stepped_offset
;
647 struct sk_buff
*root_skb
;
648 struct sk_buff
*cur_skb
;
652 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
653 unsigned int from
, unsigned int to
,
654 struct skb_seq_state
*st
);
655 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
656 struct skb_seq_state
*st
);
657 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
659 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
660 unsigned int to
, struct ts_config
*config
,
661 struct ts_state
*state
);
663 extern void __skb_get_rxhash(struct sk_buff
*skb
);
664 static inline __u32
skb_get_rxhash(struct sk_buff
*skb
)
667 __skb_get_rxhash(skb
);
672 #ifdef NET_SKBUFF_DATA_USES_OFFSET
673 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
675 return skb
->head
+ skb
->end
;
678 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
683 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
688 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
690 return skb
->end
- skb
->head
;
695 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
697 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
699 return &skb_shinfo(skb
)->hwtstamps
;
703 * skb_queue_empty - check if a queue is empty
706 * Returns true if the queue is empty, false otherwise.
708 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
710 return list
->next
== (struct sk_buff
*)list
;
714 * skb_queue_is_last - check if skb is the last entry in the queue
718 * Returns true if @skb is the last buffer on the list.
720 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
721 const struct sk_buff
*skb
)
723 return skb
->next
== (struct sk_buff
*)list
;
727 * skb_queue_is_first - check if skb is the first entry in the queue
731 * Returns true if @skb is the first buffer on the list.
733 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
734 const struct sk_buff
*skb
)
736 return skb
->prev
== (struct sk_buff
*)list
;
740 * skb_queue_next - return the next packet in the queue
742 * @skb: current buffer
744 * Return the next packet in @list after @skb. It is only valid to
745 * call this if skb_queue_is_last() evaluates to false.
747 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
748 const struct sk_buff
*skb
)
750 /* This BUG_ON may seem severe, but if we just return then we
751 * are going to dereference garbage.
753 BUG_ON(skb_queue_is_last(list
, skb
));
758 * skb_queue_prev - return the prev packet in the queue
760 * @skb: current buffer
762 * Return the prev packet in @list before @skb. It is only valid to
763 * call this if skb_queue_is_first() evaluates to false.
765 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
766 const struct sk_buff
*skb
)
768 /* This BUG_ON may seem severe, but if we just return then we
769 * are going to dereference garbage.
771 BUG_ON(skb_queue_is_first(list
, skb
));
776 * skb_get - reference buffer
777 * @skb: buffer to reference
779 * Makes another reference to a socket buffer and returns a pointer
782 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
784 atomic_inc(&skb
->users
);
789 * If users == 1, we are the only owner and are can avoid redundant
794 * skb_cloned - is the buffer a clone
795 * @skb: buffer to check
797 * Returns true if the buffer was generated with skb_clone() and is
798 * one of multiple shared copies of the buffer. Cloned buffers are
799 * shared data so must not be written to under normal circumstances.
801 static inline int skb_cloned(const struct sk_buff
*skb
)
803 return skb
->cloned
&&
804 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
808 * skb_header_cloned - is the header a clone
809 * @skb: buffer to check
811 * Returns true if modifying the header part of the buffer requires
812 * the data to be copied.
814 static inline int skb_header_cloned(const struct sk_buff
*skb
)
821 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
822 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
827 * skb_header_release - release reference to header
828 * @skb: buffer to operate on
830 * Drop a reference to the header part of the buffer. This is done
831 * by acquiring a payload reference. You must not read from the header
832 * part of skb->data after this.
834 static inline void skb_header_release(struct sk_buff
*skb
)
838 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
842 * skb_shared - is the buffer shared
843 * @skb: buffer to check
845 * Returns true if more than one person has a reference to this
848 static inline int skb_shared(const struct sk_buff
*skb
)
850 return atomic_read(&skb
->users
) != 1;
854 * skb_share_check - check if buffer is shared and if so clone it
855 * @skb: buffer to check
856 * @pri: priority for memory allocation
858 * If the buffer is shared the buffer is cloned and the old copy
859 * drops a reference. A new clone with a single reference is returned.
860 * If the buffer is not shared the original buffer is returned. When
861 * being called from interrupt status or with spinlocks held pri must
864 * NULL is returned on a memory allocation failure.
866 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
868 might_sleep_if(pri
& __GFP_WAIT
);
869 if (skb_shared(skb
)) {
870 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
882 * Copy shared buffers into a new sk_buff. We effectively do COW on
883 * packets to handle cases where we have a local reader and forward
884 * and a couple of other messy ones. The normal one is tcpdumping
885 * a packet thats being forwarded.
889 * skb_unshare - make a copy of a shared buffer
890 * @skb: buffer to check
891 * @pri: priority for memory allocation
893 * If the socket buffer is a clone then this function creates a new
894 * copy of the data, drops a reference count on the old copy and returns
895 * the new copy with the reference count at 1. If the buffer is not a clone
896 * the original buffer is returned. When called with a spinlock held or
897 * from interrupt state @pri must be %GFP_ATOMIC
899 * %NULL is returned on a memory allocation failure.
901 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
904 might_sleep_if(pri
& __GFP_WAIT
);
905 if (skb_cloned(skb
)) {
906 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
907 kfree_skb(skb
); /* Free our shared copy */
914 * skb_peek - peek at the head of an &sk_buff_head
915 * @list_: list to peek at
917 * Peek an &sk_buff. Unlike most other operations you _MUST_
918 * be careful with this one. A peek leaves the buffer on the
919 * list and someone else may run off with it. You must hold
920 * the appropriate locks or have a private queue to do this.
922 * Returns %NULL for an empty list or a pointer to the head element.
923 * The reference count is not incremented and the reference is therefore
924 * volatile. Use with caution.
926 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
928 struct sk_buff
*skb
= list_
->next
;
930 if (skb
== (struct sk_buff
*)list_
)
936 * skb_peek_next - peek skb following the given one from a queue
937 * @skb: skb to start from
938 * @list_: list to peek at
940 * Returns %NULL when the end of the list is met or a pointer to the
941 * next element. The reference count is not incremented and the
942 * reference is therefore volatile. Use with caution.
944 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
945 const struct sk_buff_head
*list_
)
947 struct sk_buff
*next
= skb
->next
;
949 if (next
== (struct sk_buff
*)list_
)
955 * skb_peek_tail - peek at the tail of an &sk_buff_head
956 * @list_: list to peek at
958 * Peek an &sk_buff. Unlike most other operations you _MUST_
959 * be careful with this one. A peek leaves the buffer on the
960 * list and someone else may run off with it. You must hold
961 * the appropriate locks or have a private queue to do this.
963 * Returns %NULL for an empty list or a pointer to the tail element.
964 * The reference count is not incremented and the reference is therefore
965 * volatile. Use with caution.
967 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
969 struct sk_buff
*skb
= list_
->prev
;
971 if (skb
== (struct sk_buff
*)list_
)
978 * skb_queue_len - get queue length
979 * @list_: list to measure
981 * Return the length of an &sk_buff queue.
983 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
989 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
990 * @list: queue to initialize
992 * This initializes only the list and queue length aspects of
993 * an sk_buff_head object. This allows to initialize the list
994 * aspects of an sk_buff_head without reinitializing things like
995 * the spinlock. It can also be used for on-stack sk_buff_head
996 * objects where the spinlock is known to not be used.
998 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1000 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1005 * This function creates a split out lock class for each invocation;
1006 * this is needed for now since a whole lot of users of the skb-queue
1007 * infrastructure in drivers have different locking usage (in hardirq)
1008 * than the networking core (in softirq only). In the long run either the
1009 * network layer or drivers should need annotation to consolidate the
1010 * main types of usage into 3 classes.
1012 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1014 spin_lock_init(&list
->lock
);
1015 __skb_queue_head_init(list
);
1018 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1019 struct lock_class_key
*class)
1021 skb_queue_head_init(list
);
1022 lockdep_set_class(&list
->lock
, class);
1026 * Insert an sk_buff on a list.
1028 * The "__skb_xxxx()" functions are the non-atomic ones that
1029 * can only be called with interrupts disabled.
1031 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
1032 static inline void __skb_insert(struct sk_buff
*newsk
,
1033 struct sk_buff
*prev
, struct sk_buff
*next
,
1034 struct sk_buff_head
*list
)
1038 next
->prev
= prev
->next
= newsk
;
1042 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1043 struct sk_buff
*prev
,
1044 struct sk_buff
*next
)
1046 struct sk_buff
*first
= list
->next
;
1047 struct sk_buff
*last
= list
->prev
;
1057 * skb_queue_splice - join two skb lists, this is designed for stacks
1058 * @list: the new list to add
1059 * @head: the place to add it in the first list
1061 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1062 struct sk_buff_head
*head
)
1064 if (!skb_queue_empty(list
)) {
1065 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1066 head
->qlen
+= list
->qlen
;
1071 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1072 * @list: the new list to add
1073 * @head: the place to add it in the first list
1075 * The list at @list is reinitialised
1077 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1078 struct sk_buff_head
*head
)
1080 if (!skb_queue_empty(list
)) {
1081 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1082 head
->qlen
+= list
->qlen
;
1083 __skb_queue_head_init(list
);
1088 * skb_queue_splice_tail - join two skb lists, each list being a queue
1089 * @list: the new list to add
1090 * @head: the place to add it in the first list
1092 static inline void skb_queue_splice_tail(const 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
;
1102 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1103 * @list: the new list to add
1104 * @head: the place to add it in the first list
1106 * Each of the lists is a queue.
1107 * The list at @list is reinitialised
1109 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1110 struct sk_buff_head
*head
)
1112 if (!skb_queue_empty(list
)) {
1113 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1114 head
->qlen
+= list
->qlen
;
1115 __skb_queue_head_init(list
);
1120 * __skb_queue_after - queue a buffer at the list head
1121 * @list: list to use
1122 * @prev: place after this buffer
1123 * @newsk: buffer to queue
1125 * Queue a buffer int the middle of a list. This function takes no locks
1126 * and you must therefore hold required locks before calling it.
1128 * A buffer cannot be placed on two lists at the same time.
1130 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1131 struct sk_buff
*prev
,
1132 struct sk_buff
*newsk
)
1134 __skb_insert(newsk
, prev
, prev
->next
, list
);
1137 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1138 struct sk_buff_head
*list
);
1140 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1141 struct sk_buff
*next
,
1142 struct sk_buff
*newsk
)
1144 __skb_insert(newsk
, next
->prev
, next
, list
);
1148 * __skb_queue_head - queue a buffer at the list head
1149 * @list: list to use
1150 * @newsk: buffer to queue
1152 * Queue a buffer at the start 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_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1158 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1159 struct sk_buff
*newsk
)
1161 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1165 * __skb_queue_tail - queue a buffer at the list tail
1166 * @list: list to use
1167 * @newsk: buffer to queue
1169 * Queue a buffer at the end of a list. This function takes no locks
1170 * and you must therefore hold required locks before calling it.
1172 * A buffer cannot be placed on two lists at the same time.
1174 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1175 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1176 struct sk_buff
*newsk
)
1178 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1182 * remove sk_buff from list. _Must_ be called atomically, and with
1185 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1186 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1188 struct sk_buff
*next
, *prev
;
1193 skb
->next
= skb
->prev
= NULL
;
1199 * __skb_dequeue - remove from the head of the queue
1200 * @list: list to dequeue from
1202 * Remove the head of the list. This function does not take any locks
1203 * so must be used with appropriate locks held only. The head item is
1204 * returned or %NULL if the list is empty.
1206 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1207 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1209 struct sk_buff
*skb
= skb_peek(list
);
1211 __skb_unlink(skb
, list
);
1216 * __skb_dequeue_tail - remove from the tail of the queue
1217 * @list: list to dequeue from
1219 * Remove the tail of the list. This function does not take any locks
1220 * so must be used with appropriate locks held only. The tail item is
1221 * returned or %NULL if the list is empty.
1223 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1224 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1226 struct sk_buff
*skb
= skb_peek_tail(list
);
1228 __skb_unlink(skb
, list
);
1233 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1235 return skb
->data_len
;
1238 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1240 return skb
->len
- skb
->data_len
;
1243 static inline int skb_pagelen(const struct sk_buff
*skb
)
1247 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1248 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1249 return len
+ skb_headlen(skb
);
1253 * __skb_fill_page_desc - initialise a paged fragment in an skb
1254 * @skb: buffer containing fragment to be initialised
1255 * @i: paged fragment index to initialise
1256 * @page: the page to use for this fragment
1257 * @off: the offset to the data with @page
1258 * @size: the length of the data
1260 * Initialises the @i'th fragment of @skb to point to &size bytes at
1261 * offset @off within @page.
1263 * Does not take any additional reference on the fragment.
1265 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1266 struct page
*page
, int off
, int size
)
1268 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1271 * Propagate page->pfmemalloc to the skb if we can. The problem is
1272 * that not all callers have unique ownership of the page. If
1273 * pfmemalloc is set, we check the mapping as a mapping implies
1274 * page->index is set (index and pfmemalloc share space).
1275 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1276 * do not lose pfmemalloc information as the pages would not be
1277 * allocated using __GFP_MEMALLOC.
1279 if (page
->pfmemalloc
&& !page
->mapping
)
1280 skb
->pfmemalloc
= true;
1281 frag
->page
.p
= page
;
1282 frag
->page_offset
= off
;
1283 skb_frag_size_set(frag
, size
);
1287 * skb_fill_page_desc - initialise a paged fragment in an skb
1288 * @skb: buffer containing fragment to be initialised
1289 * @i: paged fragment index to initialise
1290 * @page: the page to use for this fragment
1291 * @off: the offset to the data with @page
1292 * @size: the length of the data
1294 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1295 * @skb to point to &size bytes at offset @off within @page. In
1296 * addition updates @skb such that @i is the last fragment.
1298 * Does not take any additional reference on the fragment.
1300 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1301 struct page
*page
, int off
, int size
)
1303 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1304 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1307 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1308 int off
, int size
, unsigned int truesize
);
1310 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1311 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1312 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1314 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1315 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1317 return skb
->head
+ skb
->tail
;
1320 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1322 skb
->tail
= skb
->data
- skb
->head
;
1325 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1327 skb_reset_tail_pointer(skb
);
1328 skb
->tail
+= offset
;
1330 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1331 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1336 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1338 skb
->tail
= skb
->data
;
1341 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1343 skb
->tail
= skb
->data
+ offset
;
1346 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1349 * Add data to an sk_buff
1351 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1352 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1354 unsigned char *tmp
= skb_tail_pointer(skb
);
1355 SKB_LINEAR_ASSERT(skb
);
1361 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1362 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1369 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1370 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1373 BUG_ON(skb
->len
< skb
->data_len
);
1374 return skb
->data
+= len
;
1377 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1379 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1382 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1384 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1386 if (len
> skb_headlen(skb
) &&
1387 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1390 return skb
->data
+= len
;
1393 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1395 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1398 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1400 if (likely(len
<= skb_headlen(skb
)))
1402 if (unlikely(len
> skb
->len
))
1404 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1408 * skb_headroom - bytes at buffer head
1409 * @skb: buffer to check
1411 * Return the number of bytes of free space at the head of an &sk_buff.
1413 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1415 return skb
->data
- skb
->head
;
1419 * skb_tailroom - bytes at buffer end
1420 * @skb: buffer to check
1422 * Return the number of bytes of free space at the tail of an sk_buff
1424 static inline int skb_tailroom(const struct sk_buff
*skb
)
1426 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1430 * skb_availroom - bytes at buffer end
1431 * @skb: buffer to check
1433 * Return the number of bytes of free space at the tail of an sk_buff
1434 * allocated by sk_stream_alloc()
1436 static inline int skb_availroom(const struct sk_buff
*skb
)
1438 return skb_is_nonlinear(skb
) ? 0 : skb
->avail_size
- skb
->len
;
1442 * skb_reserve - adjust headroom
1443 * @skb: buffer to alter
1444 * @len: bytes to move
1446 * Increase the headroom of an empty &sk_buff by reducing the tail
1447 * room. This is only allowed for an empty buffer.
1449 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1455 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1457 skb
->inner_network_header
= skb
->network_header
;
1458 skb
->inner_transport_header
= skb
->transport_header
;
1461 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1463 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1466 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1467 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1470 return skb
->head
+ skb
->inner_transport_header
;
1473 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1475 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1478 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1481 skb_reset_inner_transport_header(skb
);
1482 skb
->inner_transport_header
+= offset
;
1485 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1487 return skb
->head
+ skb
->inner_network_header
;
1490 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1492 skb
->inner_network_header
= skb
->data
- skb
->head
;
1495 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1498 skb_reset_inner_network_header(skb
);
1499 skb
->inner_network_header
+= offset
;
1502 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1504 return skb
->transport_header
!= ~0U;
1507 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1509 return skb
->head
+ skb
->transport_header
;
1512 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1514 skb
->transport_header
= skb
->data
- skb
->head
;
1517 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1520 skb_reset_transport_header(skb
);
1521 skb
->transport_header
+= offset
;
1524 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1526 return skb
->head
+ skb
->network_header
;
1529 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1531 skb
->network_header
= skb
->data
- skb
->head
;
1534 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1536 skb_reset_network_header(skb
);
1537 skb
->network_header
+= offset
;
1540 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1542 return skb
->head
+ skb
->mac_header
;
1545 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1547 return skb
->mac_header
!= ~0U;
1550 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1552 skb
->mac_header
= skb
->data
- skb
->head
;
1555 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1557 skb_reset_mac_header(skb
);
1558 skb
->mac_header
+= offset
;
1561 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1562 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1565 return skb
->inner_transport_header
;
1568 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1570 skb
->inner_transport_header
= skb
->data
;
1573 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1576 skb
->inner_transport_header
= skb
->data
+ offset
;
1579 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1581 return skb
->inner_network_header
;
1584 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1586 skb
->inner_network_header
= skb
->data
;
1589 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1592 skb
->inner_network_header
= skb
->data
+ offset
;
1595 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1597 return skb
->transport_header
!= NULL
;
1600 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1602 return skb
->transport_header
;
1605 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1607 skb
->transport_header
= skb
->data
;
1610 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1613 skb
->transport_header
= skb
->data
+ offset
;
1616 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1618 return skb
->network_header
;
1621 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1623 skb
->network_header
= skb
->data
;
1626 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1628 skb
->network_header
= skb
->data
+ offset
;
1631 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1633 return skb
->mac_header
;
1636 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1638 return skb
->mac_header
!= NULL
;
1641 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1643 skb
->mac_header
= skb
->data
;
1646 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1648 skb
->mac_header
= skb
->data
+ offset
;
1650 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1652 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1654 if (skb_mac_header_was_set(skb
)) {
1655 const unsigned char *old_mac
= skb_mac_header(skb
);
1657 skb_set_mac_header(skb
, -skb
->mac_len
);
1658 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1662 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1664 return skb
->csum_start
- skb_headroom(skb
);
1667 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1669 return skb_transport_header(skb
) - skb
->data
;
1672 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1674 return skb
->transport_header
- skb
->network_header
;
1677 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1679 return skb
->inner_transport_header
- skb
->inner_network_header
;
1682 static inline int skb_network_offset(const struct sk_buff
*skb
)
1684 return skb_network_header(skb
) - skb
->data
;
1687 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1689 return skb_inner_network_header(skb
) - skb
->data
;
1692 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1694 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1698 * CPUs often take a performance hit when accessing unaligned memory
1699 * locations. The actual performance hit varies, it can be small if the
1700 * hardware handles it or large if we have to take an exception and fix it
1703 * Since an ethernet header is 14 bytes network drivers often end up with
1704 * the IP header at an unaligned offset. The IP header can be aligned by
1705 * shifting the start of the packet by 2 bytes. Drivers should do this
1708 * skb_reserve(skb, NET_IP_ALIGN);
1710 * The downside to this alignment of the IP header is that the DMA is now
1711 * unaligned. On some architectures the cost of an unaligned DMA is high
1712 * and this cost outweighs the gains made by aligning the IP header.
1714 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1717 #ifndef NET_IP_ALIGN
1718 #define NET_IP_ALIGN 2
1722 * The networking layer reserves some headroom in skb data (via
1723 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1724 * the header has to grow. In the default case, if the header has to grow
1725 * 32 bytes or less we avoid the reallocation.
1727 * Unfortunately this headroom changes the DMA alignment of the resulting
1728 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1729 * on some architectures. An architecture can override this value,
1730 * perhaps setting it to a cacheline in size (since that will maintain
1731 * cacheline alignment of the DMA). It must be a power of 2.
1733 * Various parts of the networking layer expect at least 32 bytes of
1734 * headroom, you should not reduce this.
1736 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1737 * to reduce average number of cache lines per packet.
1738 * get_rps_cpus() for example only access one 64 bytes aligned block :
1739 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1742 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1745 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1747 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1749 if (unlikely(skb_is_nonlinear(skb
))) {
1754 skb_set_tail_pointer(skb
, len
);
1757 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1759 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1762 return ___pskb_trim(skb
, len
);
1763 __skb_trim(skb
, len
);
1767 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1769 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1773 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1774 * @skb: buffer to alter
1777 * This is identical to pskb_trim except that the caller knows that
1778 * the skb is not cloned so we should never get an error due to out-
1781 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1783 int err
= pskb_trim(skb
, len
);
1788 * skb_orphan - orphan a buffer
1789 * @skb: buffer to orphan
1791 * If a buffer currently has an owner then we call the owner's
1792 * destructor function and make the @skb unowned. The buffer continues
1793 * to exist but is no longer charged to its former owner.
1795 static inline void skb_orphan(struct sk_buff
*skb
)
1797 if (skb
->destructor
)
1798 skb
->destructor(skb
);
1799 skb
->destructor
= NULL
;
1804 * skb_orphan_frags - orphan the frags contained in a buffer
1805 * @skb: buffer to orphan frags from
1806 * @gfp_mask: allocation mask for replacement pages
1808 * For each frag in the SKB which needs a destructor (i.e. has an
1809 * owner) create a copy of that frag and release the original
1810 * page by calling the destructor.
1812 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1814 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1816 return skb_copy_ubufs(skb
, gfp_mask
);
1820 * __skb_queue_purge - empty a list
1821 * @list: list to empty
1823 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1824 * the list and one reference dropped. This function does not take the
1825 * list lock and the caller must hold the relevant locks to use it.
1827 extern void skb_queue_purge(struct sk_buff_head
*list
);
1828 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1830 struct sk_buff
*skb
;
1831 while ((skb
= __skb_dequeue(list
)) != NULL
)
1835 extern void *netdev_alloc_frag(unsigned int fragsz
);
1837 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1838 unsigned int length
,
1842 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1843 * @dev: network device to receive on
1844 * @length: length to allocate
1846 * Allocate a new &sk_buff and assign it a usage count of one. The
1847 * buffer has unspecified headroom built in. Users should allocate
1848 * the headroom they think they need without accounting for the
1849 * built in space. The built in space is used for optimisations.
1851 * %NULL is returned if there is no free memory. Although this function
1852 * allocates memory it can be called from an interrupt.
1854 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1855 unsigned int length
)
1857 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1860 /* legacy helper around __netdev_alloc_skb() */
1861 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1864 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
1867 /* legacy helper around netdev_alloc_skb() */
1868 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
1870 return netdev_alloc_skb(NULL
, length
);
1874 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
1875 unsigned int length
, gfp_t gfp
)
1877 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
1879 if (NET_IP_ALIGN
&& skb
)
1880 skb_reserve(skb
, NET_IP_ALIGN
);
1884 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
1885 unsigned int length
)
1887 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
1891 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1892 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1893 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1894 * @order: size of the allocation
1896 * Allocate a new page.
1898 * %NULL is returned if there is no free memory.
1900 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
1901 struct sk_buff
*skb
,
1906 gfp_mask
|= __GFP_COLD
;
1908 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1909 gfp_mask
|= __GFP_MEMALLOC
;
1911 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
1912 if (skb
&& page
&& page
->pfmemalloc
)
1913 skb
->pfmemalloc
= true;
1919 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1920 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1921 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1923 * Allocate a new page.
1925 * %NULL is returned if there is no free memory.
1927 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
1928 struct sk_buff
*skb
)
1930 return __skb_alloc_pages(gfp_mask
, skb
, 0);
1934 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1935 * @page: The page that was allocated from skb_alloc_page
1936 * @skb: The skb that may need pfmemalloc set
1938 static inline void skb_propagate_pfmemalloc(struct page
*page
,
1939 struct sk_buff
*skb
)
1941 if (page
&& page
->pfmemalloc
)
1942 skb
->pfmemalloc
= true;
1946 * skb_frag_page - retrieve the page refered to by a paged fragment
1947 * @frag: the paged fragment
1949 * Returns the &struct page associated with @frag.
1951 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
1953 return frag
->page
.p
;
1957 * __skb_frag_ref - take an addition reference on a paged fragment.
1958 * @frag: the paged fragment
1960 * Takes an additional reference on the paged fragment @frag.
1962 static inline void __skb_frag_ref(skb_frag_t
*frag
)
1964 get_page(skb_frag_page(frag
));
1968 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1970 * @f: the fragment offset.
1972 * Takes an additional reference on the @f'th paged fragment of @skb.
1974 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
1976 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
1980 * __skb_frag_unref - release a reference on a paged fragment.
1981 * @frag: the paged fragment
1983 * Releases a reference on the paged fragment @frag.
1985 static inline void __skb_frag_unref(skb_frag_t
*frag
)
1987 put_page(skb_frag_page(frag
));
1991 * skb_frag_unref - release a reference on a paged fragment of an skb.
1993 * @f: the fragment offset
1995 * Releases a reference on the @f'th paged fragment of @skb.
1997 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
1999 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2003 * skb_frag_address - gets the address of the data contained in a paged fragment
2004 * @frag: the paged fragment buffer
2006 * Returns the address of the data within @frag. The page must already
2009 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2011 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2015 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2016 * @frag: the paged fragment buffer
2018 * Returns the address of the data within @frag. Checks that the page
2019 * is mapped and returns %NULL otherwise.
2021 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2023 void *ptr
= page_address(skb_frag_page(frag
));
2027 return ptr
+ frag
->page_offset
;
2031 * __skb_frag_set_page - sets the page contained in a paged fragment
2032 * @frag: the paged fragment
2033 * @page: the page to set
2035 * Sets the fragment @frag to contain @page.
2037 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2039 frag
->page
.p
= page
;
2043 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2045 * @f: the fragment offset
2046 * @page: the page to set
2048 * Sets the @f'th fragment of @skb to contain @page.
2050 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2053 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2057 * skb_frag_dma_map - maps a paged fragment via the DMA API
2058 * @dev: the device to map the fragment to
2059 * @frag: the paged fragment to map
2060 * @offset: the offset within the fragment (starting at the
2061 * fragment's own offset)
2062 * @size: the number of bytes to map
2063 * @dir: the direction of the mapping (%PCI_DMA_*)
2065 * Maps the page associated with @frag to @device.
2067 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2068 const skb_frag_t
*frag
,
2069 size_t offset
, size_t size
,
2070 enum dma_data_direction dir
)
2072 return dma_map_page(dev
, skb_frag_page(frag
),
2073 frag
->page_offset
+ offset
, size
, dir
);
2076 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2079 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2083 * skb_clone_writable - is the header of a clone writable
2084 * @skb: buffer to check
2085 * @len: length up to which to write
2087 * Returns true if modifying the header part of the cloned buffer
2088 * does not requires the data to be copied.
2090 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2092 return !skb_header_cloned(skb
) &&
2093 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2096 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2101 if (headroom
> skb_headroom(skb
))
2102 delta
= headroom
- skb_headroom(skb
);
2104 if (delta
|| cloned
)
2105 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2111 * skb_cow - copy header of skb when it is required
2112 * @skb: buffer to cow
2113 * @headroom: needed headroom
2115 * If the skb passed lacks sufficient headroom or its data part
2116 * is shared, data is reallocated. If reallocation fails, an error
2117 * is returned and original skb is not changed.
2119 * The result is skb with writable area skb->head...skb->tail
2120 * and at least @headroom of space at head.
2122 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2124 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2128 * skb_cow_head - skb_cow but only making the head writable
2129 * @skb: buffer to cow
2130 * @headroom: needed headroom
2132 * This function is identical to skb_cow except that we replace the
2133 * skb_cloned check by skb_header_cloned. It should be used when
2134 * you only need to push on some header and do not need to modify
2137 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2139 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2143 * skb_padto - pad an skbuff up to a minimal size
2144 * @skb: buffer to pad
2145 * @len: minimal length
2147 * Pads up a buffer to ensure the trailing bytes exist and are
2148 * blanked. If the buffer already contains sufficient data it
2149 * is untouched. Otherwise it is extended. Returns zero on
2150 * success. The skb is freed on error.
2153 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2155 unsigned int size
= skb
->len
;
2156 if (likely(size
>= len
))
2158 return skb_pad(skb
, len
- size
);
2161 static inline int skb_add_data(struct sk_buff
*skb
,
2162 char __user
*from
, int copy
)
2164 const int off
= skb
->len
;
2166 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2168 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2171 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2174 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2177 __skb_trim(skb
, off
);
2181 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2182 const struct page
*page
, int off
)
2185 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2187 return page
== skb_frag_page(frag
) &&
2188 off
== frag
->page_offset
+ skb_frag_size(frag
);
2193 static inline int __skb_linearize(struct sk_buff
*skb
)
2195 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2199 * skb_linearize - convert paged skb to linear one
2200 * @skb: buffer to linarize
2202 * If there is no free memory -ENOMEM is returned, otherwise zero
2203 * is returned and the old skb data released.
2205 static inline int skb_linearize(struct sk_buff
*skb
)
2207 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2211 * skb_has_shared_frag - can any frag be overwritten
2212 * @skb: buffer to test
2214 * Return true if the skb has at least one frag that might be modified
2215 * by an external entity (as in vmsplice()/sendfile())
2217 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2219 return skb_shinfo(skb
)->gso_type
& SKB_GSO_SHARED_FRAG
;
2223 * skb_linearize_cow - make sure skb is linear and writable
2224 * @skb: buffer to process
2226 * If there is no free memory -ENOMEM is returned, otherwise zero
2227 * is returned and the old skb data released.
2229 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2231 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2232 __skb_linearize(skb
) : 0;
2236 * skb_postpull_rcsum - update checksum for received skb after pull
2237 * @skb: buffer to update
2238 * @start: start of data before pull
2239 * @len: length of data pulled
2241 * After doing a pull on a received packet, you need to call this to
2242 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2243 * CHECKSUM_NONE so that it can be recomputed from scratch.
2246 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2247 const void *start
, unsigned int len
)
2249 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2250 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2253 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2256 * pskb_trim_rcsum - trim received skb and update checksum
2257 * @skb: buffer to trim
2260 * This is exactly the same as pskb_trim except that it ensures the
2261 * checksum of received packets are still valid after the operation.
2264 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2266 if (likely(len
>= skb
->len
))
2268 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2269 skb
->ip_summed
= CHECKSUM_NONE
;
2270 return __pskb_trim(skb
, len
);
2273 #define skb_queue_walk(queue, skb) \
2274 for (skb = (queue)->next; \
2275 skb != (struct sk_buff *)(queue); \
2278 #define skb_queue_walk_safe(queue, skb, tmp) \
2279 for (skb = (queue)->next, tmp = skb->next; \
2280 skb != (struct sk_buff *)(queue); \
2281 skb = tmp, tmp = skb->next)
2283 #define skb_queue_walk_from(queue, skb) \
2284 for (; skb != (struct sk_buff *)(queue); \
2287 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2288 for (tmp = skb->next; \
2289 skb != (struct sk_buff *)(queue); \
2290 skb = tmp, tmp = skb->next)
2292 #define skb_queue_reverse_walk(queue, skb) \
2293 for (skb = (queue)->prev; \
2294 skb != (struct sk_buff *)(queue); \
2297 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2298 for (skb = (queue)->prev, tmp = skb->prev; \
2299 skb != (struct sk_buff *)(queue); \
2300 skb = tmp, tmp = skb->prev)
2302 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2303 for (tmp = skb->prev; \
2304 skb != (struct sk_buff *)(queue); \
2305 skb = tmp, tmp = skb->prev)
2307 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2309 return skb_shinfo(skb
)->frag_list
!= NULL
;
2312 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2314 skb_shinfo(skb
)->frag_list
= NULL
;
2317 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2319 frag
->next
= skb_shinfo(skb
)->frag_list
;
2320 skb_shinfo(skb
)->frag_list
= frag
;
2323 #define skb_walk_frags(skb, iter) \
2324 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2326 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2327 int *peeked
, int *off
, int *err
);
2328 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2329 int noblock
, int *err
);
2330 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2331 struct poll_table_struct
*wait
);
2332 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
2333 int offset
, struct iovec
*to
,
2335 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
2338 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
2340 const struct iovec
*from
,
2343 extern int skb_copy_datagram_const_iovec(const struct sk_buff
*from
,
2345 const struct iovec
*to
,
2348 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2349 extern void skb_free_datagram_locked(struct sock
*sk
,
2350 struct sk_buff
*skb
);
2351 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
2352 unsigned int flags
);
2353 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
2354 int len
, __wsum csum
);
2355 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
2357 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
2358 const void *from
, int len
);
2359 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
2360 int offset
, u8
*to
, int len
,
2362 extern int skb_splice_bits(struct sk_buff
*skb
,
2363 unsigned int offset
,
2364 struct pipe_inode_info
*pipe
,
2366 unsigned int flags
);
2367 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2368 extern void skb_split(struct sk_buff
*skb
,
2369 struct sk_buff
*skb1
, const u32 len
);
2370 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
2373 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
,
2374 netdev_features_t features
);
2376 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2377 int len
, void *buffer
)
2379 int hlen
= skb_headlen(skb
);
2381 if (hlen
- offset
>= len
)
2382 return skb
->data
+ offset
;
2384 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2390 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2392 const unsigned int len
)
2394 memcpy(to
, skb
->data
, len
);
2397 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2398 const int offset
, void *to
,
2399 const unsigned int len
)
2401 memcpy(to
, skb
->data
+ offset
, len
);
2404 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2406 const unsigned int len
)
2408 memcpy(skb
->data
, from
, len
);
2411 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2414 const unsigned int len
)
2416 memcpy(skb
->data
+ offset
, from
, len
);
2419 extern void skb_init(void);
2421 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2427 * skb_get_timestamp - get timestamp from a skb
2428 * @skb: skb to get stamp from
2429 * @stamp: pointer to struct timeval to store stamp in
2431 * Timestamps are stored in the skb as offsets to a base timestamp.
2432 * This function converts the offset back to a struct timeval and stores
2435 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2436 struct timeval
*stamp
)
2438 *stamp
= ktime_to_timeval(skb
->tstamp
);
2441 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2442 struct timespec
*stamp
)
2444 *stamp
= ktime_to_timespec(skb
->tstamp
);
2447 static inline void __net_timestamp(struct sk_buff
*skb
)
2449 skb
->tstamp
= ktime_get_real();
2452 static inline ktime_t
net_timedelta(ktime_t t
)
2454 return ktime_sub(ktime_get_real(), t
);
2457 static inline ktime_t
net_invalid_timestamp(void)
2459 return ktime_set(0, 0);
2462 extern void skb_timestamping_init(void);
2464 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2466 extern void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2467 extern bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2469 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2471 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2475 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2480 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2483 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2485 * PHY drivers may accept clones of transmitted packets for
2486 * timestamping via their phy_driver.txtstamp method. These drivers
2487 * must call this function to return the skb back to the stack, with
2488 * or without a timestamp.
2490 * @skb: clone of the the original outgoing packet
2491 * @hwtstamps: hardware time stamps, may be NULL if not available
2494 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2495 struct skb_shared_hwtstamps
*hwtstamps
);
2498 * skb_tstamp_tx - queue clone of skb with send time stamps
2499 * @orig_skb: the original outgoing packet
2500 * @hwtstamps: hardware time stamps, may be NULL if not available
2502 * If the skb has a socket associated, then this function clones the
2503 * skb (thus sharing the actual data and optional structures), stores
2504 * the optional hardware time stamping information (if non NULL) or
2505 * generates a software time stamp (otherwise), then queues the clone
2506 * to the error queue of the socket. Errors are silently ignored.
2508 extern void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2509 struct skb_shared_hwtstamps
*hwtstamps
);
2511 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2513 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2514 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2515 skb_tstamp_tx(skb
, NULL
);
2519 * skb_tx_timestamp() - Driver hook for transmit timestamping
2521 * Ethernet MAC Drivers should call this function in their hard_xmit()
2522 * function immediately before giving the sk_buff to the MAC hardware.
2524 * @skb: A socket buffer.
2526 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2528 skb_clone_tx_timestamp(skb
);
2529 sw_tx_timestamp(skb
);
2533 * skb_complete_wifi_ack - deliver skb with wifi status
2535 * @skb: the original outgoing packet
2536 * @acked: ack status
2539 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2541 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2542 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2544 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2546 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
2550 * skb_checksum_complete - Calculate checksum of an entire packet
2551 * @skb: packet to process
2553 * This function calculates the checksum over the entire packet plus
2554 * the value of skb->csum. The latter can be used to supply the
2555 * checksum of a pseudo header as used by TCP/UDP. It returns the
2558 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2559 * this function can be used to verify that checksum on received
2560 * packets. In that case the function should return zero if the
2561 * checksum is correct. In particular, this function will return zero
2562 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2563 * hardware has already verified the correctness of the checksum.
2565 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2567 return skb_csum_unnecessary(skb
) ?
2568 0 : __skb_checksum_complete(skb
);
2571 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2572 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2573 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2575 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2576 nf_conntrack_destroy(nfct
);
2578 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2581 atomic_inc(&nfct
->use
);
2584 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2585 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
2588 atomic_inc(&skb
->users
);
2590 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
2596 #ifdef CONFIG_BRIDGE_NETFILTER
2597 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2599 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2602 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2605 atomic_inc(&nf_bridge
->use
);
2607 #endif /* CONFIG_BRIDGE_NETFILTER */
2608 static inline void nf_reset(struct sk_buff
*skb
)
2610 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2611 nf_conntrack_put(skb
->nfct
);
2614 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2615 nf_conntrack_put_reasm(skb
->nfct_reasm
);
2616 skb
->nfct_reasm
= NULL
;
2618 #ifdef CONFIG_BRIDGE_NETFILTER
2619 nf_bridge_put(skb
->nf_bridge
);
2620 skb
->nf_bridge
= NULL
;
2624 /* Note: This doesn't put any conntrack and bridge info in dst. */
2625 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2627 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2628 dst
->nfct
= src
->nfct
;
2629 nf_conntrack_get(src
->nfct
);
2630 dst
->nfctinfo
= src
->nfctinfo
;
2632 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2633 dst
->nfct_reasm
= src
->nfct_reasm
;
2634 nf_conntrack_get_reasm(src
->nfct_reasm
);
2636 #ifdef CONFIG_BRIDGE_NETFILTER
2637 dst
->nf_bridge
= src
->nf_bridge
;
2638 nf_bridge_get(src
->nf_bridge
);
2642 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2644 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2645 nf_conntrack_put(dst
->nfct
);
2647 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2648 nf_conntrack_put_reasm(dst
->nfct_reasm
);
2650 #ifdef CONFIG_BRIDGE_NETFILTER
2651 nf_bridge_put(dst
->nf_bridge
);
2653 __nf_copy(dst
, src
);
2656 #ifdef CONFIG_NETWORK_SECMARK
2657 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2659 to
->secmark
= from
->secmark
;
2662 static inline void skb_init_secmark(struct sk_buff
*skb
)
2667 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2670 static inline void skb_init_secmark(struct sk_buff
*skb
)
2674 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2676 skb
->queue_mapping
= queue_mapping
;
2679 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2681 return skb
->queue_mapping
;
2684 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2686 to
->queue_mapping
= from
->queue_mapping
;
2689 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2691 skb
->queue_mapping
= rx_queue
+ 1;
2694 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2696 return skb
->queue_mapping
- 1;
2699 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2701 return skb
->queue_mapping
!= 0;
2704 extern u16
__skb_tx_hash(const struct net_device
*dev
,
2705 const struct sk_buff
*skb
,
2706 unsigned int num_tx_queues
);
2709 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2714 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
2720 static inline bool skb_is_gso(const struct sk_buff
*skb
)
2722 return skb_shinfo(skb
)->gso_size
;
2725 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
2727 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
2730 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
2732 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
2734 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2735 * wanted then gso_type will be set. */
2736 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
2738 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
2739 unlikely(shinfo
->gso_type
== 0)) {
2740 __skb_warn_lro_forwarding(skb
);
2746 static inline void skb_forward_csum(struct sk_buff
*skb
)
2748 /* Unfortunately we don't support this one. Any brave souls? */
2749 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2750 skb
->ip_summed
= CHECKSUM_NONE
;
2754 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2755 * @skb: skb to check
2757 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2758 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2759 * use this helper, to document places where we make this assertion.
2761 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
2764 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
2768 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
2771 * skb_head_is_locked - Determine if the skb->head is locked down
2772 * @skb: skb to check
2774 * The head on skbs build around a head frag can be removed if they are
2775 * not cloned. This function returns true if the skb head is locked down
2776 * due to either being allocated via kmalloc, or by being a clone with
2777 * multiple references to the head.
2779 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
2781 return !skb
->head_frag
|| skb_cloned(skb
);
2783 #endif /* __KERNEL__ */
2784 #endif /* _LINUX_SKBUFF_H */