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>
35 #include <net/flow_keys.h>
37 /* Don't change this without changing skb_csum_unnecessary! */
38 #define CHECKSUM_NONE 0
39 #define CHECKSUM_UNNECESSARY 1
40 #define CHECKSUM_COMPLETE 2
41 #define CHECKSUM_PARTIAL 3
43 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
44 ~(SMP_CACHE_BYTES - 1))
45 #define SKB_WITH_OVERHEAD(X) \
46 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
47 #define SKB_MAX_ORDER(X, ORDER) \
48 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
49 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
50 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
52 /* return minimum truesize of one skb containing X bytes of data */
53 #define SKB_TRUESIZE(X) ((X) + \
54 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
55 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
57 /* A. Checksumming of received packets by device.
59 * NONE: device failed to checksum this packet.
60 * skb->csum is undefined.
62 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
63 * skb->csum is undefined.
64 * It is bad option, but, unfortunately, many of vendors do this.
65 * Apparently with secret goal to sell you new device, when you
66 * will add new protocol to your host. F.e. IPv6. 8)
68 * COMPLETE: the most generic way. Device supplied checksum of _all_
69 * the packet as seen by netif_rx in skb->csum.
70 * NOTE: Even if device supports only some protocols, but
71 * is able to produce some skb->csum, it MUST use COMPLETE,
74 * PARTIAL: identical to the case for output below. This may occur
75 * on a packet received directly from another Linux OS, e.g.,
76 * a virtualised Linux kernel on the same host. The packet can
77 * be treated in the same way as UNNECESSARY except that on
78 * output (i.e., forwarding) the checksum must be filled in
79 * by the OS or the hardware.
81 * B. Checksumming on output.
83 * NONE: skb is checksummed by protocol or csum is not required.
85 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
86 * from skb->csum_start to the end and to record the checksum
87 * at skb->csum_start + skb->csum_offset.
89 * Device must show its capabilities in dev->features, set
90 * at device setup time.
91 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
93 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
94 * TCP/UDP over IPv4. Sigh. Vendors like this
95 * way by an unknown reason. Though, see comment above
96 * about CHECKSUM_UNNECESSARY. 8)
97 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
99 * UNNECESSARY: device will do per protocol specific csum. Protocol drivers
100 * that do not want net to perform the checksum calculation should use
101 * this flag in their outgoing skbs.
102 * NETIF_F_FCOE_CRC this indicates the device can do FCoE FC CRC
103 * offload. Correspondingly, the FCoE protocol driver
104 * stack should use CHECKSUM_UNNECESSARY.
106 * Any questions? No questions, good. --ANK
111 struct pipe_inode_info;
113 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
114 struct nf_conntrack {
119 #ifdef CONFIG_BRIDGE_NETFILTER
120 struct nf_bridge_info {
123 struct net_device *physindev;
124 struct net_device *physoutdev;
125 unsigned long data[32 / sizeof(unsigned long)];
129 struct sk_buff_head {
130 /* These two members must be first. */
131 struct sk_buff *next;
132 struct sk_buff *prev;
140 /* To allow 64K frame to be packed as single skb without frag_list we
141 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
142 * buffers which do not start on a page boundary.
144 * Since GRO uses frags we allocate at least 16 regardless of page
147 #if (65536/PAGE_SIZE + 1) < 16
148 #define MAX_SKB_FRAGS 16UL
150 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
153 typedef struct skb_frag_struct skb_frag_t;
155 struct skb_frag_struct {
159 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
168 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
173 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
178 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
183 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
188 #define HAVE_HW_TIME_STAMP
191 * struct skb_shared_hwtstamps - hardware time stamps
192 * @hwtstamp: hardware time stamp transformed into duration
193 * since arbitrary point in time
194 * @syststamp: hwtstamp transformed to system time base
196 * Software time stamps generated by ktime_get_real() are stored in
197 * skb->tstamp. The relation between the different kinds of time
198 * stamps is as follows:
200 * syststamp and tstamp can be compared against each other in
201 * arbitrary combinations. The accuracy of a
202 * syststamp/tstamp/"syststamp from other device" comparison is
203 * limited by the accuracy of the transformation into system time
204 * base. This depends on the device driver and its underlying
207 * hwtstamps can only be compared against other hwtstamps from
210 * This structure is attached to packets as part of the
211 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
213 struct skb_shared_hwtstamps {
218 /* Definitions for tx_flags in struct skb_shared_info */
220 /* generate hardware time stamp */
221 SKBTX_HW_TSTAMP = 1 << 0,
223 /* generate software time stamp */
224 SKBTX_SW_TSTAMP = 1 << 1,
226 /* device driver is going to provide hardware time stamp */
227 SKBTX_IN_PROGRESS = 1 << 2,
229 /* device driver supports TX zero-copy buffers */
230 SKBTX_DEV_ZEROCOPY = 1 << 3,
232 /* generate wifi status information (where possible) */
233 SKBTX_WIFI_STATUS = 1 << 4,
235 /* This indicates at least one fragment might be overwritten
236 * (as in vmsplice(), sendfile() ...)
237 * If we need to compute a TX checksum, we'll need to copy
238 * all frags to avoid possible bad checksum
240 SKBTX_SHARED_FRAG = 1 << 5,
244 * The callback notifies userspace to release buffers when skb DMA is done in
245 * lower device, the skb last reference should be 0 when calling this.
246 * The zerocopy_success argument is true if zero copy transmit occurred,
247 * false on data copy or out of memory error caused by data copy attempt.
248 * The ctx field is used to track device context.
249 * The desc field is used to track userspace buffer index.
252 void (*callback)(struct ubuf_info *, bool zerocopy_success);
257 /* This data is invariant across clones and lives at
258 * the end of the header data, ie. at skb->end.
260 struct skb_shared_info {
261 unsigned char nr_frags;
263 unsigned short gso_size;
264 /* Warning: this field is not always filled in (UFO)! */
265 unsigned short gso_segs;
266 unsigned short gso_type;
267 struct sk_buff *frag_list;
268 struct skb_shared_hwtstamps hwtstamps;
272 * Warning : all fields before dataref are cleared in __alloc_skb()
276 /* Intermediate layers must ensure that destructor_arg
277 * remains valid until skb destructor */
278 void * destructor_arg;
280 /* must be last field, see pskb_expand_head() */
281 skb_frag_t frags[MAX_SKB_FRAGS];
284 /* We divide dataref into two halves. The higher 16 bits hold references
285 * to the payload part of skb->data. The lower 16 bits hold references to
286 * the entire skb->data. A clone of a headerless skb holds the length of
287 * the header in skb->hdr_len.
289 * All users must obey the rule that the skb->data reference count must be
290 * greater than or equal to the payload reference count.
292 * Holding a reference to the payload part means that the user does not
293 * care about modifications to the header part of skb->data.
295 #define SKB_DATAREF_SHIFT 16
296 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
300 SKB_FCLONE_UNAVAILABLE,
306 SKB_GSO_TCPV4 = 1 << 0,
307 SKB_GSO_UDP = 1 << 1,
309 /* This indicates the skb is from an untrusted source. */
310 SKB_GSO_DODGY = 1 << 2,
312 /* This indicates the tcp segment has CWR set. */
313 SKB_GSO_TCP_ECN = 1 << 3,
315 SKB_GSO_TCPV6 = 1 << 4,
317 SKB_GSO_FCOE = 1 << 5,
319 SKB_GSO_GRE = 1 << 6,
321 SKB_GSO_UDP_TUNNEL = 1 << 7,
324 #if BITS_PER_LONG > 32
325 #define NET_SKBUFF_DATA_USES_OFFSET 1
328 #ifdef NET_SKBUFF_DATA_USES_OFFSET
329 typedef unsigned int sk_buff_data_t;
331 typedef unsigned char *sk_buff_data_t;
334 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
335 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
336 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
340 * struct sk_buff - socket buffer
341 * @next: Next buffer in list
342 * @prev: Previous buffer in list
343 * @tstamp: Time we arrived
344 * @sk: Socket we are owned by
345 * @dev: Device we arrived on/are leaving by
346 * @cb: Control buffer. Free for use by every layer. Put private vars here
347 * @_skb_refdst: destination entry (with norefcount bit)
348 * @sp: the security path, used for xfrm
349 * @len: Length of actual data
350 * @data_len: Data length
351 * @mac_len: Length of link layer header
352 * @hdr_len: writable header length of cloned skb
353 * @csum: Checksum (must include start/offset pair)
354 * @csum_start: Offset from skb->head where checksumming should start
355 * @csum_offset: Offset from csum_start where checksum should be stored
356 * @priority: Packet queueing priority
357 * @local_df: allow local fragmentation
358 * @cloned: Head may be cloned (check refcnt to be sure)
359 * @ip_summed: Driver fed us an IP checksum
360 * @nohdr: Payload reference only, must not modify header
361 * @nfctinfo: Relationship of this skb to the connection
362 * @pkt_type: Packet class
363 * @fclone: skbuff clone status
364 * @ipvs_property: skbuff is owned by ipvs
365 * @peeked: this packet has been seen already, so stats have been
366 * done for it, don't do them again
367 * @nf_trace: netfilter packet trace flag
368 * @protocol: Packet protocol from driver
369 * @destructor: Destruct function
370 * @nfct: Associated connection, if any
371 * @nfct_reasm: netfilter conntrack re-assembly pointer
372 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
373 * @skb_iif: ifindex of device we arrived on
374 * @tc_index: Traffic control index
375 * @tc_verd: traffic control verdict
376 * @rxhash: the packet hash computed on receive
377 * @queue_mapping: Queue mapping for multiqueue devices
378 * @ndisc_nodetype: router type (from link layer)
379 * @ooo_okay: allow the mapping of a socket to a queue to be changed
380 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
382 * @wifi_acked_valid: wifi_acked was set
383 * @wifi_acked: whether frame was acked on wifi or not
384 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
385 * @dma_cookie: a cookie to one of several possible DMA operations
386 * done by skb DMA functions
387 * @secmark: security marking
388 * @mark: Generic packet mark
389 * @dropcount: total number of sk_receive_queue overflows
390 * @vlan_tci: vlan tag control information
391 * @inner_transport_header: Inner transport layer header (encapsulation)
392 * @inner_network_header: Network layer header (encapsulation)
393 * @inner_mac_header: Link layer header (encapsulation)
394 * @transport_header: Transport layer header
395 * @network_header: Network layer header
396 * @mac_header: Link layer header
397 * @tail: Tail pointer
399 * @head: Head of buffer
400 * @data: Data head pointer
401 * @truesize: Buffer size
402 * @users: User count - see {datagram,tcp}.c
406 /* These two members must be first. */
407 struct sk_buff *next;
408 struct sk_buff *prev;
413 struct net_device *dev;
416 * This is the control buffer. It is free to use for every
417 * layer. Please put your private variables there. If you
418 * want to keep them across layers you have to do a skb_clone()
419 * first. This is owned by whoever has the skb queued ATM.
421 char cb[48] __aligned(8);
423 unsigned long _skb_refdst;
439 kmemcheck_bitfield_begin(flags1);
450 kmemcheck_bitfield_end(flags1);
453 void (*destructor)(struct sk_buff *skb);
454 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
455 struct nf_conntrack *nfct;
457 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
458 struct sk_buff *nfct_reasm;
460 #ifdef CONFIG_BRIDGE_NETFILTER
461 struct nf_bridge_info *nf_bridge;
470 #ifdef CONFIG_NET_SCHED
471 __u16 tc_index; /* traffic control index */
472 #ifdef CONFIG_NET_CLS_ACT
473 __u16 tc_verd; /* traffic control verdict */
478 kmemcheck_bitfield_begin(flags2);
479 #ifdef CONFIG_IPV6_NDISC_NODETYPE
480 __u8 ndisc_nodetype:2;
485 __u8 wifi_acked_valid:1;
489 /* Encapsulation protocol and NIC drivers should use
490 * this flag to indicate to each other if the skb contains
491 * encapsulated packet or not and maybe use the inner packet
494 __u8 encapsulation:1;
495 /* 7/9 bit hole (depending on ndisc_nodetype presence) */
496 kmemcheck_bitfield_end(flags2);
498 #ifdef CONFIG_NET_DMA
499 dma_cookie_t dma_cookie;
501 #ifdef CONFIG_NETWORK_SECMARK
507 __u32 reserved_tailroom;
510 sk_buff_data_t inner_transport_header;
511 sk_buff_data_t inner_network_header;
512 sk_buff_data_t inner_mac_header;
513 sk_buff_data_t transport_header;
514 sk_buff_data_t network_header;
515 sk_buff_data_t mac_header;
516 /* These elements must be at the end, see alloc_skb() for details. */
521 unsigned int truesize;
527 * Handling routines are only of interest to the kernel
529 #include <linux/slab.h>
532 #define SKB_ALLOC_FCLONE 0x01
533 #define SKB_ALLOC_RX 0x02
535 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
536 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
538 return unlikely(skb->pfmemalloc);
542 * skb might have a dst pointer attached, refcounted or not.
543 * _skb_refdst low order bit is set if refcount was _not_ taken
545 #define SKB_DST_NOREF 1UL
546 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
549 * skb_dst - returns skb dst_entry
552 * Returns skb dst_entry, regardless of reference taken or not.
554 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
556 /* If refdst was not refcounted, check we still are in a
557 * rcu_read_lock section
559 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
560 !rcu_read_lock_held() &&
561 !rcu_read_lock_bh_held());
562 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
566 * skb_dst_set - sets skb dst
570 * Sets skb dst, assuming a reference was taken on dst and should
571 * be released by skb_dst_drop()
573 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
575 skb->_skb_refdst = (unsigned long)dst;
578 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
581 * skb_dst_is_noref - Test if skb dst isn't refcounted
584 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
586 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
589 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
591 return (struct rtable *)skb_dst(skb);
594 extern void kfree_skb(struct sk_buff *skb);
595 extern void skb_tx_error(struct sk_buff *skb);
596 extern void consume_skb(struct sk_buff *skb);
597 extern void __kfree_skb(struct sk_buff *skb);
598 extern struct kmem_cache *skbuff_head_cache;
600 extern void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
601 extern bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
602 bool *fragstolen, int *delta_truesize);
604 extern struct sk_buff *__alloc_skb(unsigned int size,
605 gfp_t priority, int flags, int node);
606 extern struct sk_buff *build_skb(void *data, unsigned int frag_size);
607 static inline struct sk_buff *alloc_skb(unsigned int size,
610 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
613 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
616 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
619 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
620 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
621 extern struct sk_buff *skb_clone(struct sk_buff *skb,
623 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
625 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
626 int headroom, gfp_t gfp_mask);
628 extern int pskb_expand_head(struct sk_buff *skb,
629 int nhead, int ntail,
631 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
632 unsigned int headroom);
633 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
634 int newheadroom, int newtailroom,
636 extern int skb_to_sgvec(struct sk_buff *skb,
637 struct scatterlist *sg, int offset,
639 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
640 struct sk_buff **trailer);
641 extern int skb_pad(struct sk_buff *skb, int pad);
642 #define dev_kfree_skb(a) consume_skb(a)
644 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
645 int getfrag(void *from, char *to, int offset,
646 int len,int odd, struct sk_buff *skb),
647 void *from, int length);
649 struct skb_seq_state {
653 __u32 stepped_offset;
654 struct sk_buff *root_skb;
655 struct sk_buff *cur_skb;
659 extern void skb_prepare_seq_read(struct sk_buff *skb,
660 unsigned int from, unsigned int to,
661 struct skb_seq_state *st);
662 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
663 struct skb_seq_state *st);
664 extern void skb_abort_seq_read(struct skb_seq_state *st);
666 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
667 unsigned int to, struct ts_config *config,
668 struct ts_state *state);
670 extern void __skb_get_rxhash(struct sk_buff *skb);
671 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
674 __skb_get_rxhash(skb);
679 #ifdef NET_SKBUFF_DATA_USES_OFFSET
680 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
682 return skb->head + skb->end;
685 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
690 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
695 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
697 return skb->end - skb->head;
702 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
704 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
706 return &skb_shinfo(skb)->hwtstamps;
710 * skb_queue_empty - check if a queue is empty
713 * Returns true if the queue is empty, false otherwise.
715 static inline int skb_queue_empty(const struct sk_buff_head *list)
717 return list->next == (struct sk_buff *)list;
721 * skb_queue_is_last - check if skb is the last entry in the queue
725 * Returns true if @skb is the last buffer on the list.
727 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
728 const struct sk_buff *skb)
730 return skb->next == (struct sk_buff *)list;
734 * skb_queue_is_first - check if skb is the first entry in the queue
738 * Returns true if @skb is the first buffer on the list.
740 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
741 const struct sk_buff *skb)
743 return skb->prev == (struct sk_buff *)list;
747 * skb_queue_next - return the next packet in the queue
749 * @skb: current buffer
751 * Return the next packet in @list after @skb. It is only valid to
752 * call this if skb_queue_is_last() evaluates to false.
754 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
755 const struct sk_buff *skb)
757 /* This BUG_ON may seem severe, but if we just return then we
758 * are going to dereference garbage.
760 BUG_ON(skb_queue_is_last(list, skb));
765 * skb_queue_prev - return the prev packet in the queue
767 * @skb: current buffer
769 * Return the prev packet in @list before @skb. It is only valid to
770 * call this if skb_queue_is_first() evaluates to false.
772 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
773 const struct sk_buff *skb)
775 /* This BUG_ON may seem severe, but if we just return then we
776 * are going to dereference garbage.
778 BUG_ON(skb_queue_is_first(list, skb));
783 * skb_get - reference buffer
784 * @skb: buffer to reference
786 * Makes another reference to a socket buffer and returns a pointer
789 static inline struct sk_buff *skb_get(struct sk_buff *skb)
791 atomic_inc(&skb->users);
796 * If users == 1, we are the only owner and are can avoid redundant
801 * skb_cloned - is the buffer a clone
802 * @skb: buffer to check
804 * Returns true if the buffer was generated with skb_clone() and is
805 * one of multiple shared copies of the buffer. Cloned buffers are
806 * shared data so must not be written to under normal circumstances.
808 static inline int skb_cloned(const struct sk_buff *skb)
810 return skb->cloned &&
811 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
814 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
816 might_sleep_if(pri & __GFP_WAIT);
819 return pskb_expand_head(skb, 0, 0, pri);
825 * skb_header_cloned - is the header a clone
826 * @skb: buffer to check
828 * Returns true if modifying the header part of the buffer requires
829 * the data to be copied.
831 static inline int skb_header_cloned(const struct sk_buff *skb)
838 dataref = atomic_read(&skb_shinfo(skb)->dataref);
839 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
844 * skb_header_release - release reference to header
845 * @skb: buffer to operate on
847 * Drop a reference to the header part of the buffer. This is done
848 * by acquiring a payload reference. You must not read from the header
849 * part of skb->data after this.
851 static inline void skb_header_release(struct sk_buff *skb)
855 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
859 * skb_shared - is the buffer shared
860 * @skb: buffer to check
862 * Returns true if more than one person has a reference to this
865 static inline int skb_shared(const struct sk_buff *skb)
867 return atomic_read(&skb->users) != 1;
871 * skb_share_check - check if buffer is shared and if so clone it
872 * @skb: buffer to check
873 * @pri: priority for memory allocation
875 * If the buffer is shared the buffer is cloned and the old copy
876 * drops a reference. A new clone with a single reference is returned.
877 * If the buffer is not shared the original buffer is returned. When
878 * being called from interrupt status or with spinlocks held pri must
881 * NULL is returned on a memory allocation failure.
883 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
885 might_sleep_if(pri & __GFP_WAIT);
886 if (skb_shared(skb)) {
887 struct sk_buff *nskb = skb_clone(skb, pri);
899 * Copy shared buffers into a new sk_buff. We effectively do COW on
900 * packets to handle cases where we have a local reader and forward
901 * and a couple of other messy ones. The normal one is tcpdumping
902 * a packet thats being forwarded.
906 * skb_unshare - make a copy of a shared buffer
907 * @skb: buffer to check
908 * @pri: priority for memory allocation
910 * If the socket buffer is a clone then this function creates a new
911 * copy of the data, drops a reference count on the old copy and returns
912 * the new copy with the reference count at 1. If the buffer is not a clone
913 * the original buffer is returned. When called with a spinlock held or
914 * from interrupt state @pri must be %GFP_ATOMIC
916 * %NULL is returned on a memory allocation failure.
918 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
921 might_sleep_if(pri & __GFP_WAIT);
922 if (skb_cloned(skb)) {
923 struct sk_buff *nskb = skb_copy(skb, pri);
924 kfree_skb(skb); /* Free our shared copy */
931 * skb_peek - peek at the head of an &sk_buff_head
932 * @list_: list to peek at
934 * Peek an &sk_buff. Unlike most other operations you _MUST_
935 * be careful with this one. A peek leaves the buffer on the
936 * list and someone else may run off with it. You must hold
937 * the appropriate locks or have a private queue to do this.
939 * Returns %NULL for an empty list or a pointer to the head element.
940 * The reference count is not incremented and the reference is therefore
941 * volatile. Use with caution.
943 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
945 struct sk_buff *skb = list_->next;
947 if (skb == (struct sk_buff *)list_)
953 * skb_peek_next - peek skb following the given one from a queue
954 * @skb: skb to start from
955 * @list_: list to peek at
957 * Returns %NULL when the end of the list is met or a pointer to the
958 * next element. The reference count is not incremented and the
959 * reference is therefore volatile. Use with caution.
961 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
962 const struct sk_buff_head *list_)
964 struct sk_buff *next = skb->next;
966 if (next == (struct sk_buff *)list_)
972 * skb_peek_tail - peek at the tail of an &sk_buff_head
973 * @list_: list to peek at
975 * Peek an &sk_buff. Unlike most other operations you _MUST_
976 * be careful with this one. A peek leaves the buffer on the
977 * list and someone else may run off with it. You must hold
978 * the appropriate locks or have a private queue to do this.
980 * Returns %NULL for an empty list or a pointer to the tail element.
981 * The reference count is not incremented and the reference is therefore
982 * volatile. Use with caution.
984 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
986 struct sk_buff *skb = list_->prev;
988 if (skb == (struct sk_buff *)list_)
995 * skb_queue_len - get queue length
996 * @list_: list to measure
998 * Return the length of an &sk_buff queue.
1000 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1006 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1007 * @list: queue to initialize
1009 * This initializes only the list and queue length aspects of
1010 * an sk_buff_head object. This allows to initialize the list
1011 * aspects of an sk_buff_head without reinitializing things like
1012 * the spinlock. It can also be used for on-stack sk_buff_head
1013 * objects where the spinlock is known to not be used.
1015 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1017 list->prev = list->next = (struct sk_buff *)list;
1022 * This function creates a split out lock class for each invocation;
1023 * this is needed for now since a whole lot of users of the skb-queue
1024 * infrastructure in drivers have different locking usage (in hardirq)
1025 * than the networking core (in softirq only). In the long run either the
1026 * network layer or drivers should need annotation to consolidate the
1027 * main types of usage into 3 classes.
1029 static inline void skb_queue_head_init(struct sk_buff_head *list)
1031 spin_lock_init(&list->lock);
1032 __skb_queue_head_init(list);
1035 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1036 struct lock_class_key *class)
1038 skb_queue_head_init(list);
1039 lockdep_set_class(&list->lock, class);
1043 * Insert an sk_buff on a list.
1045 * The "__skb_xxxx()" functions are the non-atomic ones that
1046 * can only be called with interrupts disabled.
1048 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
1049 static inline void __skb_insert(struct sk_buff *newsk,
1050 struct sk_buff *prev, struct sk_buff *next,
1051 struct sk_buff_head *list)
1055 next->prev = prev->next = newsk;
1059 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1060 struct sk_buff *prev,
1061 struct sk_buff *next)
1063 struct sk_buff *first = list->next;
1064 struct sk_buff *last = list->prev;
1074 * skb_queue_splice - join two skb lists, this is designed for stacks
1075 * @list: the new list to add
1076 * @head: the place to add it in the first list
1078 static inline void skb_queue_splice(const struct sk_buff_head *list,
1079 struct sk_buff_head *head)
1081 if (!skb_queue_empty(list)) {
1082 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1083 head->qlen += list->qlen;
1088 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1089 * @list: the new list to add
1090 * @head: the place to add it in the first list
1092 * The list at @list is reinitialised
1094 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1095 struct sk_buff_head *head)
1097 if (!skb_queue_empty(list)) {
1098 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1099 head->qlen += list->qlen;
1100 __skb_queue_head_init(list);
1105 * skb_queue_splice_tail - join two skb lists, each list being a queue
1106 * @list: the new list to add
1107 * @head: the place to add it in the first list
1109 static inline void skb_queue_splice_tail(const 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;
1119 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1120 * @list: the new list to add
1121 * @head: the place to add it in the first list
1123 * Each of the lists is a queue.
1124 * The list at @list is reinitialised
1126 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1127 struct sk_buff_head *head)
1129 if (!skb_queue_empty(list)) {
1130 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1131 head->qlen += list->qlen;
1132 __skb_queue_head_init(list);
1137 * __skb_queue_after - queue a buffer at the list head
1138 * @list: list to use
1139 * @prev: place after this buffer
1140 * @newsk: buffer to queue
1142 * Queue a buffer int the middle of a list. This function takes no locks
1143 * and you must therefore hold required locks before calling it.
1145 * A buffer cannot be placed on two lists at the same time.
1147 static inline void __skb_queue_after(struct sk_buff_head *list,
1148 struct sk_buff *prev,
1149 struct sk_buff *newsk)
1151 __skb_insert(newsk, prev, prev->next, list);
1154 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1155 struct sk_buff_head *list);
1157 static inline void __skb_queue_before(struct sk_buff_head *list,
1158 struct sk_buff *next,
1159 struct sk_buff *newsk)
1161 __skb_insert(newsk, next->prev, next, list);
1165 * __skb_queue_head - queue a buffer at the list head
1166 * @list: list to use
1167 * @newsk: buffer to queue
1169 * Queue a buffer at the start 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_head(struct sk_buff_head *list, struct sk_buff *newsk);
1175 static inline void __skb_queue_head(struct sk_buff_head *list,
1176 struct sk_buff *newsk)
1178 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1182 * __skb_queue_tail - queue a buffer at the list tail
1183 * @list: list to use
1184 * @newsk: buffer to queue
1186 * Queue a buffer at the end of a list. This function takes no locks
1187 * and you must therefore hold required locks before calling it.
1189 * A buffer cannot be placed on two lists at the same time.
1191 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1192 static inline void __skb_queue_tail(struct sk_buff_head *list,
1193 struct sk_buff *newsk)
1195 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1199 * remove sk_buff from list. _Must_ be called atomically, and with
1202 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1203 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1205 struct sk_buff *next, *prev;
1210 skb->next = skb->prev = NULL;
1216 * __skb_dequeue - remove from the head of the queue
1217 * @list: list to dequeue from
1219 * Remove the head of the list. This function does not take any locks
1220 * so must be used with appropriate locks held only. The head item is
1221 * returned or %NULL if the list is empty.
1223 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1224 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1226 struct sk_buff *skb = skb_peek(list);
1228 __skb_unlink(skb, list);
1233 * __skb_dequeue_tail - remove from the tail of the queue
1234 * @list: list to dequeue from
1236 * Remove the tail of the list. This function does not take any locks
1237 * so must be used with appropriate locks held only. The tail item is
1238 * returned or %NULL if the list is empty.
1240 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1241 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1243 struct sk_buff *skb = skb_peek_tail(list);
1245 __skb_unlink(skb, list);
1250 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1252 return skb->data_len;
1255 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1257 return skb->len - skb->data_len;
1260 static inline int skb_pagelen(const struct sk_buff *skb)
1264 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1265 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1266 return len + skb_headlen(skb);
1270 * __skb_fill_page_desc - initialise a paged fragment in an skb
1271 * @skb: buffer containing fragment to be initialised
1272 * @i: paged fragment index to initialise
1273 * @page: the page to use for this fragment
1274 * @off: the offset to the data with @page
1275 * @size: the length of the data
1277 * Initialises the @i'th fragment of @skb to point to &size bytes at
1278 * offset @off within @page.
1280 * Does not take any additional reference on the fragment.
1282 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1283 struct page *page, int off, int size)
1285 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1288 * Propagate page->pfmemalloc to the skb if we can. The problem is
1289 * that not all callers have unique ownership of the page. If
1290 * pfmemalloc is set, we check the mapping as a mapping implies
1291 * page->index is set (index and pfmemalloc share space).
1292 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1293 * do not lose pfmemalloc information as the pages would not be
1294 * allocated using __GFP_MEMALLOC.
1296 frag->page.p = page;
1297 frag->page_offset = off;
1298 skb_frag_size_set(frag, size);
1300 page = compound_head(page);
1301 if (page->pfmemalloc && !page->mapping)
1302 skb->pfmemalloc = true;
1306 * skb_fill_page_desc - initialise a paged fragment in an skb
1307 * @skb: buffer containing fragment to be initialised
1308 * @i: paged fragment index to initialise
1309 * @page: the page to use for this fragment
1310 * @off: the offset to the data with @page
1311 * @size: the length of the data
1313 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1314 * @skb to point to &size bytes at offset @off within @page. In
1315 * addition updates @skb such that @i is the last fragment.
1317 * Does not take any additional reference on the fragment.
1319 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1320 struct page *page, int off, int size)
1322 __skb_fill_page_desc(skb, i, page, off, size);
1323 skb_shinfo(skb)->nr_frags = i + 1;
1326 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1327 int off, int size, unsigned int truesize);
1329 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1330 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1331 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1333 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1334 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1336 return skb->head + skb->tail;
1339 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1341 skb->tail = skb->data - skb->head;
1344 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1346 skb_reset_tail_pointer(skb);
1347 skb->tail += offset;
1349 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1350 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1355 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1357 skb->tail = skb->data;
1360 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1362 skb->tail = skb->data + offset;
1365 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1368 * Add data to an sk_buff
1370 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1371 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1373 unsigned char *tmp = skb_tail_pointer(skb);
1374 SKB_LINEAR_ASSERT(skb);
1380 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1381 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1388 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1389 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1392 BUG_ON(skb->len < skb->data_len);
1393 return skb->data += len;
1396 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1398 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1401 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1403 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1405 if (len > skb_headlen(skb) &&
1406 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1409 return skb->data += len;
1412 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1414 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1417 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1419 if (likely(len <= skb_headlen(skb)))
1421 if (unlikely(len > skb->len))
1423 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1427 * skb_headroom - bytes at buffer head
1428 * @skb: buffer to check
1430 * Return the number of bytes of free space at the head of an &sk_buff.
1432 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1434 return skb->data - skb->head;
1438 * skb_tailroom - bytes at buffer end
1439 * @skb: buffer to check
1441 * Return the number of bytes of free space at the tail of an sk_buff
1443 static inline int skb_tailroom(const struct sk_buff *skb)
1445 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1449 * skb_availroom - bytes at buffer end
1450 * @skb: buffer to check
1452 * Return the number of bytes of free space at the tail of an sk_buff
1453 * allocated by sk_stream_alloc()
1455 static inline int skb_availroom(const struct sk_buff *skb)
1457 if (skb_is_nonlinear(skb))
1460 return skb->end - skb->tail - skb->reserved_tailroom;
1464 * skb_reserve - adjust headroom
1465 * @skb: buffer to alter
1466 * @len: bytes to move
1468 * Increase the headroom of an empty &sk_buff by reducing the tail
1469 * room. This is only allowed for an empty buffer.
1471 static inline void skb_reserve(struct sk_buff *skb, int len)
1477 static inline void skb_reset_inner_headers(struct sk_buff *skb)
1479 skb->inner_mac_header = skb->mac_header;
1480 skb->inner_network_header = skb->network_header;
1481 skb->inner_transport_header = skb->transport_header;
1484 static inline void skb_reset_mac_len(struct sk_buff *skb)
1486 skb->mac_len = skb->network_header - skb->mac_header;
1489 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1490 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1493 return skb->head + skb->inner_transport_header;
1496 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1498 skb->inner_transport_header = skb->data - skb->head;
1501 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1504 skb_reset_inner_transport_header(skb);
1505 skb->inner_transport_header += offset;
1508 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1510 return skb->head + skb->inner_network_header;
1513 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1515 skb->inner_network_header = skb->data - skb->head;
1518 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1521 skb_reset_inner_network_header(skb);
1522 skb->inner_network_header += offset;
1525 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1527 return skb->head + skb->inner_mac_header;
1530 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1532 skb->inner_mac_header = skb->data - skb->head;
1535 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1538 skb_reset_inner_mac_header(skb);
1539 skb->inner_mac_header += offset;
1541 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1543 return skb->transport_header != ~0U;
1546 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1548 return skb->head + skb->transport_header;
1551 static inline void skb_reset_transport_header(struct sk_buff *skb)
1553 skb->transport_header = skb->data - skb->head;
1556 static inline void skb_set_transport_header(struct sk_buff *skb,
1559 skb_reset_transport_header(skb);
1560 skb->transport_header += offset;
1563 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1565 return skb->head + skb->network_header;
1568 static inline void skb_reset_network_header(struct sk_buff *skb)
1570 skb->network_header = skb->data - skb->head;
1573 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1575 skb_reset_network_header(skb);
1576 skb->network_header += offset;
1579 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1581 return skb->head + skb->mac_header;
1584 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1586 return skb->mac_header != ~0U;
1589 static inline void skb_reset_mac_header(struct sk_buff *skb)
1591 skb->mac_header = skb->data - skb->head;
1594 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1596 skb_reset_mac_header(skb);
1597 skb->mac_header += offset;
1600 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1601 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1604 return skb->inner_transport_header;
1607 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1609 skb->inner_transport_header = skb->data;
1612 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1615 skb->inner_transport_header = skb->data + offset;
1618 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1620 return skb->inner_network_header;
1623 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1625 skb->inner_network_header = skb->data;
1628 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1631 skb->inner_network_header = skb->data + offset;
1634 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1636 return skb->inner_mac_header;
1639 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1641 skb->inner_mac_header = skb->data;
1644 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1647 skb->inner_mac_header = skb->data + offset;
1649 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1651 return skb->transport_header != NULL;
1654 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1656 return skb->transport_header;
1659 static inline void skb_reset_transport_header(struct sk_buff *skb)
1661 skb->transport_header = skb->data;
1664 static inline void skb_set_transport_header(struct sk_buff *skb,
1667 skb->transport_header = skb->data + offset;
1670 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1672 return skb->network_header;
1675 static inline void skb_reset_network_header(struct sk_buff *skb)
1677 skb->network_header = skb->data;
1680 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1682 skb->network_header = skb->data + offset;
1685 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1687 return skb->mac_header;
1690 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1692 return skb->mac_header != NULL;
1695 static inline void skb_reset_mac_header(struct sk_buff *skb)
1697 skb->mac_header = skb->data;
1700 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1702 skb->mac_header = skb->data + offset;
1704 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1706 static inline void skb_probe_transport_header(struct sk_buff *skb,
1707 const int offset_hint)
1709 struct flow_keys keys;
1711 if (skb_transport_header_was_set(skb))
1713 else if (skb_flow_dissect(skb, &keys))
1714 skb_set_transport_header(skb, keys.thoff);
1716 skb_set_transport_header(skb, offset_hint);
1719 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1721 if (skb_mac_header_was_set(skb)) {
1722 const unsigned char *old_mac = skb_mac_header(skb);
1724 skb_set_mac_header(skb, -skb->mac_len);
1725 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1729 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1731 return skb->csum_start - skb_headroom(skb);
1734 static inline int skb_transport_offset(const struct sk_buff *skb)
1736 return skb_transport_header(skb) - skb->data;
1739 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1741 return skb->transport_header - skb->network_header;
1744 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
1746 return skb->inner_transport_header - skb->inner_network_header;
1749 static inline int skb_network_offset(const struct sk_buff *skb)
1751 return skb_network_header(skb) - skb->data;
1754 static inline int skb_inner_network_offset(const struct sk_buff *skb)
1756 return skb_inner_network_header(skb) - skb->data;
1759 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1761 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1765 * CPUs often take a performance hit when accessing unaligned memory
1766 * locations. The actual performance hit varies, it can be small if the
1767 * hardware handles it or large if we have to take an exception and fix it
1770 * Since an ethernet header is 14 bytes network drivers often end up with
1771 * the IP header at an unaligned offset. The IP header can be aligned by
1772 * shifting the start of the packet by 2 bytes. Drivers should do this
1775 * skb_reserve(skb, NET_IP_ALIGN);
1777 * The downside to this alignment of the IP header is that the DMA is now
1778 * unaligned. On some architectures the cost of an unaligned DMA is high
1779 * and this cost outweighs the gains made by aligning the IP header.
1781 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1784 #ifndef NET_IP_ALIGN
1785 #define NET_IP_ALIGN 2
1789 * The networking layer reserves some headroom in skb data (via
1790 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1791 * the header has to grow. In the default case, if the header has to grow
1792 * 32 bytes or less we avoid the reallocation.
1794 * Unfortunately this headroom changes the DMA alignment of the resulting
1795 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1796 * on some architectures. An architecture can override this value,
1797 * perhaps setting it to a cacheline in size (since that will maintain
1798 * cacheline alignment of the DMA). It must be a power of 2.
1800 * Various parts of the networking layer expect at least 32 bytes of
1801 * headroom, you should not reduce this.
1803 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1804 * to reduce average number of cache lines per packet.
1805 * get_rps_cpus() for example only access one 64 bytes aligned block :
1806 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1809 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1812 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1814 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1816 if (unlikely(skb_is_nonlinear(skb))) {
1821 skb_set_tail_pointer(skb, len);
1824 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1826 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1829 return ___pskb_trim(skb, len);
1830 __skb_trim(skb, len);
1834 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1836 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1840 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1841 * @skb: buffer to alter
1844 * This is identical to pskb_trim except that the caller knows that
1845 * the skb is not cloned so we should never get an error due to out-
1848 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1850 int err = pskb_trim(skb, len);
1855 * skb_orphan - orphan a buffer
1856 * @skb: buffer to orphan
1858 * If a buffer currently has an owner then we call the owner's
1859 * destructor function and make the @skb unowned. The buffer continues
1860 * to exist but is no longer charged to its former owner.
1862 static inline void skb_orphan(struct sk_buff *skb)
1864 if (skb->destructor)
1865 skb->destructor(skb);
1866 skb->destructor = NULL;
1871 * skb_orphan_frags - orphan the frags contained in a buffer
1872 * @skb: buffer to orphan frags from
1873 * @gfp_mask: allocation mask for replacement pages
1875 * For each frag in the SKB which needs a destructor (i.e. has an
1876 * owner) create a copy of that frag and release the original
1877 * page by calling the destructor.
1879 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
1881 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
1883 return skb_copy_ubufs(skb, gfp_mask);
1887 * __skb_queue_purge - empty a list
1888 * @list: list to empty
1890 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1891 * the list and one reference dropped. This function does not take the
1892 * list lock and the caller must hold the relevant locks to use it.
1894 extern void skb_queue_purge(struct sk_buff_head *list);
1895 static inline void __skb_queue_purge(struct sk_buff_head *list)
1897 struct sk_buff *skb;
1898 while ((skb = __skb_dequeue(list)) != NULL)
1902 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
1903 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
1904 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
1906 extern void *netdev_alloc_frag(unsigned int fragsz);
1908 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1909 unsigned int length,
1913 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1914 * @dev: network device to receive on
1915 * @length: length to allocate
1917 * Allocate a new &sk_buff and assign it a usage count of one. The
1918 * buffer has unspecified headroom built in. Users should allocate
1919 * the headroom they think they need without accounting for the
1920 * built in space. The built in space is used for optimisations.
1922 * %NULL is returned if there is no free memory. Although this function
1923 * allocates memory it can be called from an interrupt.
1925 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1926 unsigned int length)
1928 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1931 /* legacy helper around __netdev_alloc_skb() */
1932 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1935 return __netdev_alloc_skb(NULL, length, gfp_mask);
1938 /* legacy helper around netdev_alloc_skb() */
1939 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
1941 return netdev_alloc_skb(NULL, length);
1945 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1946 unsigned int length, gfp_t gfp)
1948 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1950 if (NET_IP_ALIGN && skb)
1951 skb_reserve(skb, NET_IP_ALIGN);
1955 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1956 unsigned int length)
1958 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1962 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1963 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1964 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1965 * @order: size of the allocation
1967 * Allocate a new page.
1969 * %NULL is returned if there is no free memory.
1971 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
1972 struct sk_buff *skb,
1977 gfp_mask |= __GFP_COLD;
1979 if (!(gfp_mask & __GFP_NOMEMALLOC))
1980 gfp_mask |= __GFP_MEMALLOC;
1982 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
1983 if (skb && page && page->pfmemalloc)
1984 skb->pfmemalloc = true;
1990 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1991 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1992 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1994 * Allocate a new page.
1996 * %NULL is returned if there is no free memory.
1998 static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
1999 struct sk_buff *skb)
2001 return __skb_alloc_pages(gfp_mask, skb, 0);
2005 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2006 * @page: The page that was allocated from skb_alloc_page
2007 * @skb: The skb that may need pfmemalloc set
2009 static inline void skb_propagate_pfmemalloc(struct page *page,
2010 struct sk_buff *skb)
2012 if (page && page->pfmemalloc)
2013 skb->pfmemalloc = true;
2017 * skb_frag_page - retrieve the page refered to by a paged fragment
2018 * @frag: the paged fragment
2020 * Returns the &struct page associated with @frag.
2022 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2024 return frag->page.p;
2028 * __skb_frag_ref - take an addition reference on a paged fragment.
2029 * @frag: the paged fragment
2031 * Takes an additional reference on the paged fragment @frag.
2033 static inline void __skb_frag_ref(skb_frag_t *frag)
2035 get_page(skb_frag_page(frag));
2039 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2041 * @f: the fragment offset.
2043 * Takes an additional reference on the @f'th paged fragment of @skb.
2045 static inline void skb_frag_ref(struct sk_buff *skb, int f)
2047 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
2051 * __skb_frag_unref - release a reference on a paged fragment.
2052 * @frag: the paged fragment
2054 * Releases a reference on the paged fragment @frag.
2056 static inline void __skb_frag_unref(skb_frag_t *frag)
2058 put_page(skb_frag_page(frag));
2062 * skb_frag_unref - release a reference on a paged fragment of an skb.
2064 * @f: the fragment offset
2066 * Releases a reference on the @f'th paged fragment of @skb.
2068 static inline void skb_frag_unref(struct sk_buff *skb, int f)
2070 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
2074 * skb_frag_address - gets the address of the data contained in a paged fragment
2075 * @frag: the paged fragment buffer
2077 * Returns the address of the data within @frag. The page must already
2080 static inline void *skb_frag_address(const skb_frag_t *frag)
2082 return page_address(skb_frag_page(frag)) + frag->page_offset;
2086 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2087 * @frag: the paged fragment buffer
2089 * Returns the address of the data within @frag. Checks that the page
2090 * is mapped and returns %NULL otherwise.
2092 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
2094 void *ptr = page_address(skb_frag_page(frag));
2098 return ptr + frag->page_offset;
2102 * __skb_frag_set_page - sets the page contained in a paged fragment
2103 * @frag: the paged fragment
2104 * @page: the page to set
2106 * Sets the fragment @frag to contain @page.
2108 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
2110 frag->page.p = page;
2114 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2116 * @f: the fragment offset
2117 * @page: the page to set
2119 * Sets the @f'th fragment of @skb to contain @page.
2121 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
2124 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
2128 * skb_frag_dma_map - maps a paged fragment via the DMA API
2129 * @dev: the device to map the fragment to
2130 * @frag: the paged fragment to map
2131 * @offset: the offset within the fragment (starting at the
2132 * fragment's own offset)
2133 * @size: the number of bytes to map
2134 * @dir: the direction of the mapping (%PCI_DMA_*)
2136 * Maps the page associated with @frag to @device.
2138 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
2139 const skb_frag_t *frag,
2140 size_t offset, size_t size,
2141 enum dma_data_direction dir)
2143 return dma_map_page(dev, skb_frag_page(frag),
2144 frag->page_offset + offset, size, dir);
2147 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
2150 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
2154 * skb_clone_writable - is the header of a clone writable
2155 * @skb: buffer to check
2156 * @len: length up to which to write
2158 * Returns true if modifying the header part of the cloned buffer
2159 * does not requires the data to be copied.
2161 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
2163 return !skb_header_cloned(skb) &&
2164 skb_headroom(skb) + len <= skb->hdr_len;
2167 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
2172 if (headroom > skb_headroom(skb))
2173 delta = headroom - skb_headroom(skb);
2175 if (delta || cloned)
2176 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2182 * skb_cow - copy header of skb when it is required
2183 * @skb: buffer to cow
2184 * @headroom: needed headroom
2186 * If the skb passed lacks sufficient headroom or its data part
2187 * is shared, data is reallocated. If reallocation fails, an error
2188 * is returned and original skb is not changed.
2190 * The result is skb with writable area skb->head...skb->tail
2191 * and at least @headroom of space at head.
2193 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2195 return __skb_cow(skb, headroom, skb_cloned(skb));
2199 * skb_cow_head - skb_cow but only making the head writable
2200 * @skb: buffer to cow
2201 * @headroom: needed headroom
2203 * This function is identical to skb_cow except that we replace the
2204 * skb_cloned check by skb_header_cloned. It should be used when
2205 * you only need to push on some header and do not need to modify
2208 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2210 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2214 * skb_padto - pad an skbuff up to a minimal size
2215 * @skb: buffer to pad
2216 * @len: minimal length
2218 * Pads up a buffer to ensure the trailing bytes exist and are
2219 * blanked. If the buffer already contains sufficient data it
2220 * is untouched. Otherwise it is extended. Returns zero on
2221 * success. The skb is freed on error.
2224 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2226 unsigned int size = skb->len;
2227 if (likely(size >= len))
2229 return skb_pad(skb, len - size);
2232 static inline int skb_add_data(struct sk_buff *skb,
2233 char __user *from, int copy)
2235 const int off = skb->len;
2237 if (skb->ip_summed == CHECKSUM_NONE) {
2239 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2242 skb->csum = csum_block_add(skb->csum, csum, off);
2245 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2248 __skb_trim(skb, off);
2252 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2253 const struct page *page, int off)
2256 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2258 return page == skb_frag_page(frag) &&
2259 off == frag->page_offset + skb_frag_size(frag);
2264 static inline int __skb_linearize(struct sk_buff *skb)
2266 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2270 * skb_linearize - convert paged skb to linear one
2271 * @skb: buffer to linarize
2273 * If there is no free memory -ENOMEM is returned, otherwise zero
2274 * is returned and the old skb data released.
2276 static inline int skb_linearize(struct sk_buff *skb)
2278 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2282 * skb_has_shared_frag - can any frag be overwritten
2283 * @skb: buffer to test
2285 * Return true if the skb has at least one frag that might be modified
2286 * by an external entity (as in vmsplice()/sendfile())
2288 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
2290 return skb_is_nonlinear(skb) &&
2291 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
2295 * skb_linearize_cow - make sure skb is linear and writable
2296 * @skb: buffer to process
2298 * If there is no free memory -ENOMEM is returned, otherwise zero
2299 * is returned and the old skb data released.
2301 static inline int skb_linearize_cow(struct sk_buff *skb)
2303 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2304 __skb_linearize(skb) : 0;
2308 * skb_postpull_rcsum - update checksum for received skb after pull
2309 * @skb: buffer to update
2310 * @start: start of data before pull
2311 * @len: length of data pulled
2313 * After doing a pull on a received packet, you need to call this to
2314 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2315 * CHECKSUM_NONE so that it can be recomputed from scratch.
2318 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2319 const void *start, unsigned int len)
2321 if (skb->ip_summed == CHECKSUM_COMPLETE)
2322 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2325 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2328 * pskb_trim_rcsum - trim received skb and update checksum
2329 * @skb: buffer to trim
2332 * This is exactly the same as pskb_trim except that it ensures the
2333 * checksum of received packets are still valid after the operation.
2336 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2338 if (likely(len >= skb->len))
2340 if (skb->ip_summed == CHECKSUM_COMPLETE)
2341 skb->ip_summed = CHECKSUM_NONE;
2342 return __pskb_trim(skb, len);
2345 #define skb_queue_walk(queue, skb) \
2346 for (skb = (queue)->next; \
2347 skb != (struct sk_buff *)(queue); \
2350 #define skb_queue_walk_safe(queue, skb, tmp) \
2351 for (skb = (queue)->next, tmp = skb->next; \
2352 skb != (struct sk_buff *)(queue); \
2353 skb = tmp, tmp = skb->next)
2355 #define skb_queue_walk_from(queue, skb) \
2356 for (; skb != (struct sk_buff *)(queue); \
2359 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2360 for (tmp = skb->next; \
2361 skb != (struct sk_buff *)(queue); \
2362 skb = tmp, tmp = skb->next)
2364 #define skb_queue_reverse_walk(queue, skb) \
2365 for (skb = (queue)->prev; \
2366 skb != (struct sk_buff *)(queue); \
2369 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2370 for (skb = (queue)->prev, tmp = skb->prev; \
2371 skb != (struct sk_buff *)(queue); \
2372 skb = tmp, tmp = skb->prev)
2374 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2375 for (tmp = skb->prev; \
2376 skb != (struct sk_buff *)(queue); \
2377 skb = tmp, tmp = skb->prev)
2379 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2381 return skb_shinfo(skb)->frag_list != NULL;
2384 static inline void skb_frag_list_init(struct sk_buff *skb)
2386 skb_shinfo(skb)->frag_list = NULL;
2389 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2391 frag->next = skb_shinfo(skb)->frag_list;
2392 skb_shinfo(skb)->frag_list = frag;
2395 #define skb_walk_frags(skb, iter) \
2396 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2398 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2399 int *peeked, int *off, int *err);
2400 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2401 int noblock, int *err);
2402 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2403 struct poll_table_struct *wait);
2404 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2405 int offset, struct iovec *to,
2407 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2410 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2412 const struct iovec *from,
2415 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2417 const struct iovec *to,
2420 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2421 extern void skb_free_datagram_locked(struct sock *sk,
2422 struct sk_buff *skb);
2423 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2424 unsigned int flags);
2425 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2426 int len, __wsum csum);
2427 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2429 extern int skb_store_bits(struct sk_buff *skb, int offset,
2430 const void *from, int len);
2431 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2432 int offset, u8 *to, int len,
2434 extern int skb_splice_bits(struct sk_buff *skb,
2435 unsigned int offset,
2436 struct pipe_inode_info *pipe,
2438 unsigned int flags);
2439 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2440 extern void skb_split(struct sk_buff *skb,
2441 struct sk_buff *skb1, const u32 len);
2442 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2445 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2446 netdev_features_t features);
2448 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2449 int len, void *buffer)
2451 int hlen = skb_headlen(skb);
2453 if (hlen - offset >= len)
2454 return skb->data + offset;
2456 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2462 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2464 const unsigned int len)
2466 memcpy(to, skb->data, len);
2469 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2470 const int offset, void *to,
2471 const unsigned int len)
2473 memcpy(to, skb->data + offset, len);
2476 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2478 const unsigned int len)
2480 memcpy(skb->data, from, len);
2483 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2486 const unsigned int len)
2488 memcpy(skb->data + offset, from, len);
2491 extern void skb_init(void);
2493 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2499 * skb_get_timestamp - get timestamp from a skb
2500 * @skb: skb to get stamp from
2501 * @stamp: pointer to struct timeval to store stamp in
2503 * Timestamps are stored in the skb as offsets to a base timestamp.
2504 * This function converts the offset back to a struct timeval and stores
2507 static inline void skb_get_timestamp(const struct sk_buff *skb,
2508 struct timeval *stamp)
2510 *stamp = ktime_to_timeval(skb->tstamp);
2513 static inline void skb_get_timestampns(const struct sk_buff *skb,
2514 struct timespec *stamp)
2516 *stamp = ktime_to_timespec(skb->tstamp);
2519 static inline void __net_timestamp(struct sk_buff *skb)
2521 skb->tstamp = ktime_get_real();
2524 static inline ktime_t net_timedelta(ktime_t t)
2526 return ktime_sub(ktime_get_real(), t);
2529 static inline ktime_t net_invalid_timestamp(void)
2531 return ktime_set(0, 0);
2534 extern void skb_timestamping_init(void);
2536 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2538 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2539 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2541 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2543 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2547 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2552 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2555 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2557 * PHY drivers may accept clones of transmitted packets for
2558 * timestamping via their phy_driver.txtstamp method. These drivers
2559 * must call this function to return the skb back to the stack, with
2560 * or without a timestamp.
2562 * @skb: clone of the the original outgoing packet
2563 * @hwtstamps: hardware time stamps, may be NULL if not available
2566 void skb_complete_tx_timestamp(struct sk_buff *skb,
2567 struct skb_shared_hwtstamps *hwtstamps);
2570 * skb_tstamp_tx - queue clone of skb with send time stamps
2571 * @orig_skb: the original outgoing packet
2572 * @hwtstamps: hardware time stamps, may be NULL if not available
2574 * If the skb has a socket associated, then this function clones the
2575 * skb (thus sharing the actual data and optional structures), stores
2576 * the optional hardware time stamping information (if non NULL) or
2577 * generates a software time stamp (otherwise), then queues the clone
2578 * to the error queue of the socket. Errors are silently ignored.
2580 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2581 struct skb_shared_hwtstamps *hwtstamps);
2583 static inline void sw_tx_timestamp(struct sk_buff *skb)
2585 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2586 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2587 skb_tstamp_tx(skb, NULL);
2591 * skb_tx_timestamp() - Driver hook for transmit timestamping
2593 * Ethernet MAC Drivers should call this function in their hard_xmit()
2594 * function immediately before giving the sk_buff to the MAC hardware.
2596 * @skb: A socket buffer.
2598 static inline void skb_tx_timestamp(struct sk_buff *skb)
2600 skb_clone_tx_timestamp(skb);
2601 sw_tx_timestamp(skb);
2605 * skb_complete_wifi_ack - deliver skb with wifi status
2607 * @skb: the original outgoing packet
2608 * @acked: ack status
2611 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2613 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2614 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2616 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2618 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2622 * skb_checksum_complete - Calculate checksum of an entire packet
2623 * @skb: packet to process
2625 * This function calculates the checksum over the entire packet plus
2626 * the value of skb->csum. The latter can be used to supply the
2627 * checksum of a pseudo header as used by TCP/UDP. It returns the
2630 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2631 * this function can be used to verify that checksum on received
2632 * packets. In that case the function should return zero if the
2633 * checksum is correct. In particular, this function will return zero
2634 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2635 * hardware has already verified the correctness of the checksum.
2637 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2639 return skb_csum_unnecessary(skb) ?
2640 0 : __skb_checksum_complete(skb);
2643 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2644 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2645 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2647 if (nfct && atomic_dec_and_test(&nfct->use))
2648 nf_conntrack_destroy(nfct);
2650 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2653 atomic_inc(&nfct->use);
2656 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2657 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2660 atomic_inc(&skb->users);
2662 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2668 #ifdef CONFIG_BRIDGE_NETFILTER
2669 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2671 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2674 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2677 atomic_inc(&nf_bridge->use);
2679 #endif /* CONFIG_BRIDGE_NETFILTER */
2680 static inline void nf_reset(struct sk_buff *skb)
2682 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2683 nf_conntrack_put(skb->nfct);
2686 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2687 nf_conntrack_put_reasm(skb->nfct_reasm);
2688 skb->nfct_reasm = NULL;
2690 #ifdef CONFIG_BRIDGE_NETFILTER
2691 nf_bridge_put(skb->nf_bridge);
2692 skb->nf_bridge = NULL;
2696 /* Note: This doesn't put any conntrack and bridge info in dst. */
2697 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2699 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2700 dst->nfct = src->nfct;
2701 nf_conntrack_get(src->nfct);
2702 dst->nfctinfo = src->nfctinfo;
2704 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2705 dst->nfct_reasm = src->nfct_reasm;
2706 nf_conntrack_get_reasm(src->nfct_reasm);
2708 #ifdef CONFIG_BRIDGE_NETFILTER
2709 dst->nf_bridge = src->nf_bridge;
2710 nf_bridge_get(src->nf_bridge);
2714 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2716 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2717 nf_conntrack_put(dst->nfct);
2719 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2720 nf_conntrack_put_reasm(dst->nfct_reasm);
2722 #ifdef CONFIG_BRIDGE_NETFILTER
2723 nf_bridge_put(dst->nf_bridge);
2725 __nf_copy(dst, src);
2728 #ifdef CONFIG_NETWORK_SECMARK
2729 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2731 to->secmark = from->secmark;
2734 static inline void skb_init_secmark(struct sk_buff *skb)
2739 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2742 static inline void skb_init_secmark(struct sk_buff *skb)
2746 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2748 skb->queue_mapping = queue_mapping;
2751 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2753 return skb->queue_mapping;
2756 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2758 to->queue_mapping = from->queue_mapping;
2761 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2763 skb->queue_mapping = rx_queue + 1;
2766 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2768 return skb->queue_mapping - 1;
2771 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2773 return skb->queue_mapping != 0;
2776 extern u16 __skb_tx_hash(const struct net_device *dev,
2777 const struct sk_buff *skb,
2778 unsigned int num_tx_queues);
2781 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2786 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2792 /* Keeps track of mac header offset relative to skb->head.
2793 * It is useful for TSO of Tunneling protocol. e.g. GRE.
2794 * For non-tunnel skb it points to skb_mac_header() and for
2795 * tunnel skb it points to outer mac header. */
2799 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
2801 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
2803 return (skb_mac_header(inner_skb) - inner_skb->head) -
2804 SKB_GSO_CB(inner_skb)->mac_offset;
2807 static inline bool skb_is_gso(const struct sk_buff *skb)
2809 return skb_shinfo(skb)->gso_size;
2812 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
2814 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2817 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2819 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2821 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2822 * wanted then gso_type will be set. */
2823 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2825 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2826 unlikely(shinfo->gso_type == 0)) {
2827 __skb_warn_lro_forwarding(skb);
2833 static inline void skb_forward_csum(struct sk_buff *skb)
2835 /* Unfortunately we don't support this one. Any brave souls? */
2836 if (skb->ip_summed == CHECKSUM_COMPLETE)
2837 skb->ip_summed = CHECKSUM_NONE;
2841 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2842 * @skb: skb to check
2844 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2845 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2846 * use this helper, to document places where we make this assertion.
2848 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2851 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2855 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2857 u32 __skb_get_poff(const struct sk_buff *skb);
2860 * skb_head_is_locked - Determine if the skb->head is locked down
2861 * @skb: skb to check
2863 * The head on skbs build around a head frag can be removed if they are
2864 * not cloned. This function returns true if the skb head is locked down
2865 * due to either being allocated via kmalloc, or by being a clone with
2866 * multiple references to the head.
2868 static inline bool skb_head_is_locked(const struct sk_buff *skb)
2870 return !skb->head_frag || skb_cloned(skb);
2872 #endif /* __KERNEL__ */
2873 #endif /* _LINUX_SKBUFF_H */