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/cache.h>
23 #include <linux/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/dmaengine.h>
31 #include <linux/hrtimer.h>
32 #include <linux/dma-mapping.h>
34 /* Don't change this without changing skb_csum_unnecessary! */
35 #define CHECKSUM_NONE 0
36 #define CHECKSUM_UNNECESSARY 1
37 #define CHECKSUM_COMPLETE 2
38 #define CHECKSUM_PARTIAL 3
40 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
41 ~(SMP_CACHE_BYTES - 1))
42 #define SKB_WITH_OVERHEAD(X) \
43 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
44 #define SKB_MAX_ORDER(X, ORDER) \
45 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
46 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
47 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
49 /* return minimum truesize of one skb containing X bytes of data */
50 #define SKB_TRUESIZE(X) ((X) + \
51 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
52 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
54 /* A. Checksumming of received packets by device.
56 * NONE: device failed to checksum this packet.
57 * skb->csum is undefined.
59 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
60 * skb->csum is undefined.
61 * It is bad option, but, unfortunately, many of vendors do this.
62 * Apparently with secret goal to sell you new device, when you
63 * will add new protocol to your host. F.e. IPv6. 8)
65 * COMPLETE: the most generic way. Device supplied checksum of _all_
66 * the packet as seen by netif_rx in skb->csum.
67 * NOTE: Even if device supports only some protocols, but
68 * is able to produce some skb->csum, it MUST use COMPLETE,
71 * PARTIAL: identical to the case for output below. This may occur
72 * on a packet received directly from another Linux OS, e.g.,
73 * a virtualised Linux kernel on the same host. The packet can
74 * be treated in the same way as UNNECESSARY except that on
75 * output (i.e., forwarding) the checksum must be filled in
76 * by the OS or the hardware.
78 * B. Checksumming on output.
80 * NONE: skb is checksummed by protocol or csum is not required.
82 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
83 * from skb->csum_start to the end and to record the checksum
84 * at skb->csum_start + skb->csum_offset.
86 * Device must show its capabilities in dev->features, set
87 * at device setup time.
88 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
90 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
91 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
92 * TCP/UDP over IPv4. Sigh. Vendors like this
93 * way by an unknown reason. Though, see comment above
94 * about CHECKSUM_UNNECESSARY. 8)
95 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
97 * Any questions? No questions, good. --ANK
102 struct pipe_inode_info;
104 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
105 struct nf_conntrack {
110 #ifdef CONFIG_BRIDGE_NETFILTER
111 struct nf_bridge_info {
113 struct net_device *physindev;
114 struct net_device *physoutdev;
116 unsigned long data[32 / sizeof(unsigned long)];
120 struct sk_buff_head {
121 /* These two members must be first. */
122 struct sk_buff *next;
123 struct sk_buff *prev;
131 /* To allow 64K frame to be packed as single skb without frag_list. Since
132 * GRO uses frags we allocate at least 16 regardless of page size.
134 #if (65536/PAGE_SIZE + 2) < 16
135 #define MAX_SKB_FRAGS 16UL
137 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
140 typedef struct skb_frag_struct skb_frag_t;
142 struct skb_frag_struct {
146 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
155 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
160 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
165 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
170 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
175 #define HAVE_HW_TIME_STAMP
178 * struct skb_shared_hwtstamps - hardware time stamps
179 * @hwtstamp: hardware time stamp transformed into duration
180 * since arbitrary point in time
181 * @syststamp: hwtstamp transformed to system time base
183 * Software time stamps generated by ktime_get_real() are stored in
184 * skb->tstamp. The relation between the different kinds of time
185 * stamps is as follows:
187 * syststamp and tstamp can be compared against each other in
188 * arbitrary combinations. The accuracy of a
189 * syststamp/tstamp/"syststamp from other device" comparison is
190 * limited by the accuracy of the transformation into system time
191 * base. This depends on the device driver and its underlying
194 * hwtstamps can only be compared against other hwtstamps from
197 * This structure is attached to packets as part of the
198 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
200 struct skb_shared_hwtstamps {
205 /* Definitions for tx_flags in struct skb_shared_info */
207 /* generate hardware time stamp */
208 SKBTX_HW_TSTAMP = 1 << 0,
210 /* generate software time stamp */
211 SKBTX_SW_TSTAMP = 1 << 1,
213 /* device driver is going to provide hardware time stamp */
214 SKBTX_IN_PROGRESS = 1 << 2,
216 /* device driver supports TX zero-copy buffers */
217 SKBTX_DEV_ZEROCOPY = 1 << 3,
221 * The callback notifies userspace to release buffers when skb DMA is done in
222 * lower device, the skb last reference should be 0 when calling this.
223 * The desc is used to track userspace buffer index.
226 void (*callback)(void *);
231 /* This data is invariant across clones and lives at
232 * the end of the header data, ie. at skb->end.
234 struct skb_shared_info {
235 unsigned short nr_frags;
236 unsigned short gso_size;
237 /* Warning: this field is not always filled in (UFO)! */
238 unsigned short gso_segs;
239 unsigned short gso_type;
242 struct sk_buff *frag_list;
243 struct skb_shared_hwtstamps hwtstamps;
246 * Warning : all fields before dataref are cleared in __alloc_skb()
250 /* Intermediate layers must ensure that destructor_arg
251 * remains valid until skb destructor */
252 void * destructor_arg;
254 /* must be last field, see pskb_expand_head() */
255 skb_frag_t frags[MAX_SKB_FRAGS];
258 /* We divide dataref into two halves. The higher 16 bits hold references
259 * to the payload part of skb->data. The lower 16 bits hold references to
260 * the entire skb->data. A clone of a headerless skb holds the length of
261 * the header in skb->hdr_len.
263 * All users must obey the rule that the skb->data reference count must be
264 * greater than or equal to the payload reference count.
266 * Holding a reference to the payload part means that the user does not
267 * care about modifications to the header part of skb->data.
269 #define SKB_DATAREF_SHIFT 16
270 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
274 SKB_FCLONE_UNAVAILABLE,
280 SKB_GSO_TCPV4 = 1 << 0,
281 SKB_GSO_UDP = 1 << 1,
283 /* This indicates the skb is from an untrusted source. */
284 SKB_GSO_DODGY = 1 << 2,
286 /* This indicates the tcp segment has CWR set. */
287 SKB_GSO_TCP_ECN = 1 << 3,
289 SKB_GSO_TCPV6 = 1 << 4,
291 SKB_GSO_FCOE = 1 << 5,
294 #if BITS_PER_LONG > 32
295 #define NET_SKBUFF_DATA_USES_OFFSET 1
298 #ifdef NET_SKBUFF_DATA_USES_OFFSET
299 typedef unsigned int sk_buff_data_t;
301 typedef unsigned char *sk_buff_data_t;
304 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
305 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
306 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
310 * struct sk_buff - socket buffer
311 * @next: Next buffer in list
312 * @prev: Previous buffer in list
313 * @tstamp: Time we arrived
314 * @sk: Socket we are owned by
315 * @dev: Device we arrived on/are leaving by
316 * @cb: Control buffer. Free for use by every layer. Put private vars here
317 * @_skb_refdst: destination entry (with norefcount bit)
318 * @sp: the security path, used for xfrm
319 * @len: Length of actual data
320 * @data_len: Data length
321 * @mac_len: Length of link layer header
322 * @hdr_len: writable header length of cloned skb
323 * @csum: Checksum (must include start/offset pair)
324 * @csum_start: Offset from skb->head where checksumming should start
325 * @csum_offset: Offset from csum_start where checksum should be stored
326 * @priority: Packet queueing priority
327 * @local_df: allow local fragmentation
328 * @cloned: Head may be cloned (check refcnt to be sure)
329 * @ip_summed: Driver fed us an IP checksum
330 * @nohdr: Payload reference only, must not modify header
331 * @nfctinfo: Relationship of this skb to the connection
332 * @pkt_type: Packet class
333 * @fclone: skbuff clone status
334 * @ipvs_property: skbuff is owned by ipvs
335 * @peeked: this packet has been seen already, so stats have been
336 * done for it, don't do them again
337 * @nf_trace: netfilter packet trace flag
338 * @protocol: Packet protocol from driver
339 * @destructor: Destruct function
340 * @nfct: Associated connection, if any
341 * @nfct_reasm: netfilter conntrack re-assembly pointer
342 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
343 * @skb_iif: ifindex of device we arrived on
344 * @tc_index: Traffic control index
345 * @tc_verd: traffic control verdict
346 * @rxhash: the packet hash computed on receive
347 * @queue_mapping: Queue mapping for multiqueue devices
348 * @ndisc_nodetype: router type (from link layer)
349 * @ooo_okay: allow the mapping of a socket to a queue to be changed
350 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
352 * @dma_cookie: a cookie to one of several possible DMA operations
353 * done by skb DMA functions
354 * @secmark: security marking
355 * @mark: Generic packet mark
356 * @dropcount: total number of sk_receive_queue overflows
357 * @vlan_tci: vlan tag control information
358 * @transport_header: Transport layer header
359 * @network_header: Network layer header
360 * @mac_header: Link layer header
361 * @tail: Tail pointer
363 * @head: Head of buffer
364 * @data: Data head pointer
365 * @truesize: Buffer size
366 * @users: User count - see {datagram,tcp}.c
370 /* These two members must be first. */
371 struct sk_buff *next;
372 struct sk_buff *prev;
377 struct net_device *dev;
380 * This is the control buffer. It is free to use for every
381 * layer. Please put your private variables there. If you
382 * want to keep them across layers you have to do a skb_clone()
383 * first. This is owned by whoever has the skb queued ATM.
385 char cb[48] __aligned(8);
387 unsigned long _skb_refdst;
403 kmemcheck_bitfield_begin(flags1);
414 kmemcheck_bitfield_end(flags1);
417 void (*destructor)(struct sk_buff *skb);
418 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
419 struct nf_conntrack *nfct;
421 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
422 struct sk_buff *nfct_reasm;
424 #ifdef CONFIG_BRIDGE_NETFILTER
425 struct nf_bridge_info *nf_bridge;
429 #ifdef CONFIG_NET_SCHED
430 __u16 tc_index; /* traffic control index */
431 #ifdef CONFIG_NET_CLS_ACT
432 __u16 tc_verd; /* traffic control verdict */
439 kmemcheck_bitfield_begin(flags2);
440 #ifdef CONFIG_IPV6_NDISC_NODETYPE
441 __u8 ndisc_nodetype:2;
445 kmemcheck_bitfield_end(flags2);
449 #ifdef CONFIG_NET_DMA
450 dma_cookie_t dma_cookie;
452 #ifdef CONFIG_NETWORK_SECMARK
458 __u32 reserved_tailroom;
463 sk_buff_data_t transport_header;
464 sk_buff_data_t network_header;
465 sk_buff_data_t mac_header;
466 /* These elements must be at the end, see alloc_skb() for details. */
471 unsigned int truesize;
477 * Handling routines are only of interest to the kernel
479 #include <linux/slab.h>
481 #include <asm/system.h>
484 * skb might have a dst pointer attached, refcounted or not.
485 * _skb_refdst low order bit is set if refcount was _not_ taken
487 #define SKB_DST_NOREF 1UL
488 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
491 * skb_dst - returns skb dst_entry
494 * Returns skb dst_entry, regardless of reference taken or not.
496 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
498 /* If refdst was not refcounted, check we still are in a
499 * rcu_read_lock section
501 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
502 !rcu_read_lock_held() &&
503 !rcu_read_lock_bh_held());
504 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
508 * skb_dst_set - sets skb dst
512 * Sets skb dst, assuming a reference was taken on dst and should
513 * be released by skb_dst_drop()
515 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
517 skb->_skb_refdst = (unsigned long)dst;
520 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
523 * skb_dst_is_noref - Test if skb dst isn't refcounted
526 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
528 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
531 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
533 return (struct rtable *)skb_dst(skb);
536 extern void kfree_skb(struct sk_buff *skb);
537 extern void consume_skb(struct sk_buff *skb);
538 extern void __kfree_skb(struct sk_buff *skb);
539 extern struct sk_buff *__alloc_skb(unsigned int size,
540 gfp_t priority, int fclone, int node);
541 static inline struct sk_buff *alloc_skb(unsigned int size,
544 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
547 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
550 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
553 extern void skb_recycle(struct sk_buff *skb);
554 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
556 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
557 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
558 extern struct sk_buff *skb_clone(struct sk_buff *skb,
560 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
562 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
564 extern int pskb_expand_head(struct sk_buff *skb,
565 int nhead, int ntail,
567 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
568 unsigned int headroom);
569 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
570 int newheadroom, int newtailroom,
572 extern int skb_to_sgvec(struct sk_buff *skb,
573 struct scatterlist *sg, int offset,
575 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
576 struct sk_buff **trailer);
577 extern int skb_pad(struct sk_buff *skb, int pad);
578 #define dev_kfree_skb(a) consume_skb(a)
580 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
581 int getfrag(void *from, char *to, int offset,
582 int len,int odd, struct sk_buff *skb),
583 void *from, int length);
585 struct skb_seq_state {
589 __u32 stepped_offset;
590 struct sk_buff *root_skb;
591 struct sk_buff *cur_skb;
595 extern void skb_prepare_seq_read(struct sk_buff *skb,
596 unsigned int from, unsigned int to,
597 struct skb_seq_state *st);
598 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
599 struct skb_seq_state *st);
600 extern void skb_abort_seq_read(struct skb_seq_state *st);
602 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
603 unsigned int to, struct ts_config *config,
604 struct ts_state *state);
606 extern void __skb_get_rxhash(struct sk_buff *skb);
607 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
610 __skb_get_rxhash(skb);
615 #ifdef NET_SKBUFF_DATA_USES_OFFSET
616 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
618 return skb->head + skb->end;
621 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
628 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
630 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
632 return &skb_shinfo(skb)->hwtstamps;
636 * skb_queue_empty - check if a queue is empty
639 * Returns true if the queue is empty, false otherwise.
641 static inline int skb_queue_empty(const struct sk_buff_head *list)
643 return list->next == (struct sk_buff *)list;
647 * skb_queue_is_last - check if skb is the last entry in the queue
651 * Returns true if @skb is the last buffer on the list.
653 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
654 const struct sk_buff *skb)
656 return skb->next == (struct sk_buff *)list;
660 * skb_queue_is_first - check if skb is the first entry in the queue
664 * Returns true if @skb is the first buffer on the list.
666 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
667 const struct sk_buff *skb)
669 return skb->prev == (struct sk_buff *)list;
673 * skb_queue_next - return the next packet in the queue
675 * @skb: current buffer
677 * Return the next packet in @list after @skb. It is only valid to
678 * call this if skb_queue_is_last() evaluates to false.
680 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
681 const struct sk_buff *skb)
683 /* This BUG_ON may seem severe, but if we just return then we
684 * are going to dereference garbage.
686 BUG_ON(skb_queue_is_last(list, skb));
691 * skb_queue_prev - return the prev packet in the queue
693 * @skb: current buffer
695 * Return the prev packet in @list before @skb. It is only valid to
696 * call this if skb_queue_is_first() evaluates to false.
698 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
699 const struct sk_buff *skb)
701 /* This BUG_ON may seem severe, but if we just return then we
702 * are going to dereference garbage.
704 BUG_ON(skb_queue_is_first(list, skb));
709 * skb_get - reference buffer
710 * @skb: buffer to reference
712 * Makes another reference to a socket buffer and returns a pointer
715 static inline struct sk_buff *skb_get(struct sk_buff *skb)
717 atomic_inc(&skb->users);
722 * If users == 1, we are the only owner and are can avoid redundant
727 * skb_cloned - is the buffer a clone
728 * @skb: buffer to check
730 * Returns true if the buffer was generated with skb_clone() and is
731 * one of multiple shared copies of the buffer. Cloned buffers are
732 * shared data so must not be written to under normal circumstances.
734 static inline int skb_cloned(const struct sk_buff *skb)
736 return skb->cloned &&
737 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
740 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
742 might_sleep_if(pri & __GFP_WAIT);
745 return pskb_expand_head(skb, 0, 0, pri);
751 * skb_header_cloned - is the header a clone
752 * @skb: buffer to check
754 * Returns true if modifying the header part of the buffer requires
755 * the data to be copied.
757 static inline int skb_header_cloned(const struct sk_buff *skb)
764 dataref = atomic_read(&skb_shinfo(skb)->dataref);
765 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
770 * skb_header_release - release reference to header
771 * @skb: buffer to operate on
773 * Drop a reference to the header part of the buffer. This is done
774 * by acquiring a payload reference. You must not read from the header
775 * part of skb->data after this.
777 static inline void skb_header_release(struct sk_buff *skb)
781 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
785 * skb_shared - is the buffer shared
786 * @skb: buffer to check
788 * Returns true if more than one person has a reference to this
791 static inline int skb_shared(const struct sk_buff *skb)
793 return atomic_read(&skb->users) != 1;
797 * skb_share_check - check if buffer is shared and if so clone it
798 * @skb: buffer to check
799 * @pri: priority for memory allocation
801 * If the buffer is shared the buffer is cloned and the old copy
802 * drops a reference. A new clone with a single reference is returned.
803 * If the buffer is not shared the original buffer is returned. When
804 * being called from interrupt status or with spinlocks held pri must
807 * NULL is returned on a memory allocation failure.
809 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
812 might_sleep_if(pri & __GFP_WAIT);
813 if (skb_shared(skb)) {
814 struct sk_buff *nskb = skb_clone(skb, pri);
822 * Copy shared buffers into a new sk_buff. We effectively do COW on
823 * packets to handle cases where we have a local reader and forward
824 * and a couple of other messy ones. The normal one is tcpdumping
825 * a packet thats being forwarded.
829 * skb_unshare - make a copy of a shared buffer
830 * @skb: buffer to check
831 * @pri: priority for memory allocation
833 * If the socket buffer is a clone then this function creates a new
834 * copy of the data, drops a reference count on the old copy and returns
835 * the new copy with the reference count at 1. If the buffer is not a clone
836 * the original buffer is returned. When called with a spinlock held or
837 * from interrupt state @pri must be %GFP_ATOMIC
839 * %NULL is returned on a memory allocation failure.
841 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
844 might_sleep_if(pri & __GFP_WAIT);
845 if (skb_cloned(skb)) {
846 struct sk_buff *nskb = skb_copy(skb, pri);
847 kfree_skb(skb); /* Free our shared copy */
854 * skb_peek - peek at the head of an &sk_buff_head
855 * @list_: list to peek at
857 * Peek an &sk_buff. Unlike most other operations you _MUST_
858 * be careful with this one. A peek leaves the buffer on the
859 * list and someone else may run off with it. You must hold
860 * the appropriate locks or have a private queue to do this.
862 * Returns %NULL for an empty list or a pointer to the head element.
863 * The reference count is not incremented and the reference is therefore
864 * volatile. Use with caution.
866 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
868 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
869 if (list == (struct sk_buff *)list_)
875 * skb_peek_tail - peek at the tail of an &sk_buff_head
876 * @list_: list to peek at
878 * Peek an &sk_buff. Unlike most other operations you _MUST_
879 * be careful with this one. A peek leaves the buffer on the
880 * list and someone else may run off with it. You must hold
881 * the appropriate locks or have a private queue to do this.
883 * Returns %NULL for an empty list or a pointer to the tail element.
884 * The reference count is not incremented and the reference is therefore
885 * volatile. Use with caution.
887 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
889 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
890 if (list == (struct sk_buff *)list_)
896 * skb_queue_len - get queue length
897 * @list_: list to measure
899 * Return the length of an &sk_buff queue.
901 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
907 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
908 * @list: queue to initialize
910 * This initializes only the list and queue length aspects of
911 * an sk_buff_head object. This allows to initialize the list
912 * aspects of an sk_buff_head without reinitializing things like
913 * the spinlock. It can also be used for on-stack sk_buff_head
914 * objects where the spinlock is known to not be used.
916 static inline void __skb_queue_head_init(struct sk_buff_head *list)
918 list->prev = list->next = (struct sk_buff *)list;
923 * This function creates a split out lock class for each invocation;
924 * this is needed for now since a whole lot of users of the skb-queue
925 * infrastructure in drivers have different locking usage (in hardirq)
926 * than the networking core (in softirq only). In the long run either the
927 * network layer or drivers should need annotation to consolidate the
928 * main types of usage into 3 classes.
930 static inline void skb_queue_head_init(struct sk_buff_head *list)
932 spin_lock_init(&list->lock);
933 __skb_queue_head_init(list);
936 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
937 struct lock_class_key *class)
939 skb_queue_head_init(list);
940 lockdep_set_class(&list->lock, class);
944 * Insert an sk_buff on a list.
946 * The "__skb_xxxx()" functions are the non-atomic ones that
947 * can only be called with interrupts disabled.
949 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
950 static inline void __skb_insert(struct sk_buff *newsk,
951 struct sk_buff *prev, struct sk_buff *next,
952 struct sk_buff_head *list)
956 next->prev = prev->next = newsk;
960 static inline void __skb_queue_splice(const struct sk_buff_head *list,
961 struct sk_buff *prev,
962 struct sk_buff *next)
964 struct sk_buff *first = list->next;
965 struct sk_buff *last = list->prev;
975 * skb_queue_splice - join two skb lists, this is designed for stacks
976 * @list: the new list to add
977 * @head: the place to add it in the first list
979 static inline void skb_queue_splice(const struct sk_buff_head *list,
980 struct sk_buff_head *head)
982 if (!skb_queue_empty(list)) {
983 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
984 head->qlen += list->qlen;
989 * skb_queue_splice - join two skb lists and reinitialise the emptied list
990 * @list: the new list to add
991 * @head: the place to add it in the first list
993 * The list at @list is reinitialised
995 static inline void skb_queue_splice_init(struct sk_buff_head *list,
996 struct sk_buff_head *head)
998 if (!skb_queue_empty(list)) {
999 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1000 head->qlen += list->qlen;
1001 __skb_queue_head_init(list);
1006 * skb_queue_splice_tail - join two skb lists, each list being a queue
1007 * @list: the new list to add
1008 * @head: the place to add it in the first list
1010 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1011 struct sk_buff_head *head)
1013 if (!skb_queue_empty(list)) {
1014 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1015 head->qlen += list->qlen;
1020 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1021 * @list: the new list to add
1022 * @head: the place to add it in the first list
1024 * Each of the lists is a queue.
1025 * The list at @list is reinitialised
1027 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1028 struct sk_buff_head *head)
1030 if (!skb_queue_empty(list)) {
1031 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1032 head->qlen += list->qlen;
1033 __skb_queue_head_init(list);
1038 * __skb_queue_after - queue a buffer at the list head
1039 * @list: list to use
1040 * @prev: place after this buffer
1041 * @newsk: buffer to queue
1043 * Queue a buffer int the middle of a list. This function takes no locks
1044 * and you must therefore hold required locks before calling it.
1046 * A buffer cannot be placed on two lists at the same time.
1048 static inline void __skb_queue_after(struct sk_buff_head *list,
1049 struct sk_buff *prev,
1050 struct sk_buff *newsk)
1052 __skb_insert(newsk, prev, prev->next, list);
1055 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1056 struct sk_buff_head *list);
1058 static inline void __skb_queue_before(struct sk_buff_head *list,
1059 struct sk_buff *next,
1060 struct sk_buff *newsk)
1062 __skb_insert(newsk, next->prev, next, list);
1066 * __skb_queue_head - queue a buffer at the list head
1067 * @list: list to use
1068 * @newsk: buffer to queue
1070 * Queue a buffer at the start of a list. This function takes no locks
1071 * and you must therefore hold required locks before calling it.
1073 * A buffer cannot be placed on two lists at the same time.
1075 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1076 static inline void __skb_queue_head(struct sk_buff_head *list,
1077 struct sk_buff *newsk)
1079 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1083 * __skb_queue_tail - queue a buffer at the list tail
1084 * @list: list to use
1085 * @newsk: buffer to queue
1087 * Queue a buffer at the end of a list. This function takes no locks
1088 * and you must therefore hold required locks before calling it.
1090 * A buffer cannot be placed on two lists at the same time.
1092 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1093 static inline void __skb_queue_tail(struct sk_buff_head *list,
1094 struct sk_buff *newsk)
1096 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1100 * remove sk_buff from list. _Must_ be called atomically, and with
1103 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1104 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1106 struct sk_buff *next, *prev;
1111 skb->next = skb->prev = NULL;
1117 * __skb_dequeue - remove from the head of the queue
1118 * @list: list to dequeue from
1120 * Remove the head of the list. This function does not take any locks
1121 * so must be used with appropriate locks held only. The head item is
1122 * returned or %NULL if the list is empty.
1124 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1125 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1127 struct sk_buff *skb = skb_peek(list);
1129 __skb_unlink(skb, list);
1134 * __skb_dequeue_tail - remove from the tail of the queue
1135 * @list: list to dequeue from
1137 * Remove the tail of the list. This function does not take any locks
1138 * so must be used with appropriate locks held only. The tail item is
1139 * returned or %NULL if the list is empty.
1141 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1142 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1144 struct sk_buff *skb = skb_peek_tail(list);
1146 __skb_unlink(skb, list);
1151 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1153 return skb->data_len;
1156 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1158 return skb->len - skb->data_len;
1161 static inline int skb_pagelen(const struct sk_buff *skb)
1165 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1166 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1167 return len + skb_headlen(skb);
1170 static inline bool skb_has_frags(const struct sk_buff *skb)
1172 return skb_shinfo(skb)->nr_frags;
1176 * __skb_fill_page_desc - initialise a paged fragment in an skb
1177 * @skb: buffer containing fragment to be initialised
1178 * @i: paged fragment index to initialise
1179 * @page: the page to use for this fragment
1180 * @off: the offset to the data with @page
1181 * @size: the length of the data
1183 * Initialises the @i'th fragment of @skb to point to &size bytes at
1184 * offset @off within @page.
1186 * Does not take any additional reference on the fragment.
1188 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1189 struct page *page, int off, int size)
1191 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1193 frag->page.p = page;
1194 frag->page_offset = off;
1195 skb_frag_size_set(frag, size);
1199 * skb_fill_page_desc - initialise a paged fragment in an skb
1200 * @skb: buffer containing fragment to be initialised
1201 * @i: paged fragment index to initialise
1202 * @page: the page to use for this fragment
1203 * @off: the offset to the data with @page
1204 * @size: the length of the data
1206 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1207 * @skb to point to &size bytes at offset @off within @page. In
1208 * addition updates @skb such that @i is the last fragment.
1210 * Does not take any additional reference on the fragment.
1212 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1213 struct page *page, int off, int size)
1215 __skb_fill_page_desc(skb, i, page, off, size);
1216 skb_shinfo(skb)->nr_frags = i + 1;
1219 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1222 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1223 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1224 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1226 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1227 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1229 return skb->head + skb->tail;
1232 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1234 skb->tail = skb->data - skb->head;
1237 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1239 skb_reset_tail_pointer(skb);
1240 skb->tail += offset;
1242 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1243 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1248 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1250 skb->tail = skb->data;
1253 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1255 skb->tail = skb->data + offset;
1258 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1261 * Add data to an sk_buff
1263 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1264 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1266 unsigned char *tmp = skb_tail_pointer(skb);
1267 SKB_LINEAR_ASSERT(skb);
1273 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1274 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1281 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1282 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1285 BUG_ON(skb->len < skb->data_len);
1286 return skb->data += len;
1289 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1291 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1294 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1296 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1298 if (len > skb_headlen(skb) &&
1299 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1302 return skb->data += len;
1305 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1307 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1310 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1312 if (likely(len <= skb_headlen(skb)))
1314 if (unlikely(len > skb->len))
1316 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1320 * skb_headroom - bytes at buffer head
1321 * @skb: buffer to check
1323 * Return the number of bytes of free space at the head of an &sk_buff.
1325 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1327 return skb->data - skb->head;
1331 * skb_tailroom - bytes at buffer end
1332 * @skb: buffer to check
1334 * Return the number of bytes of free space at the tail of an sk_buff
1336 static inline int skb_tailroom(const struct sk_buff *skb)
1338 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1342 * skb_availroom - bytes at buffer end
1343 * @skb: buffer to check
1345 * Return the number of bytes of free space at the tail of an sk_buff
1346 * allocated by sk_stream_alloc()
1348 static inline int skb_availroom(const struct sk_buff *skb)
1350 if (skb_is_nonlinear(skb))
1353 return skb->end - skb->tail - skb->reserved_tailroom;
1357 * skb_reserve - adjust headroom
1358 * @skb: buffer to alter
1359 * @len: bytes to move
1361 * Increase the headroom of an empty &sk_buff by reducing the tail
1362 * room. This is only allowed for an empty buffer.
1364 static inline void skb_reserve(struct sk_buff *skb, int len)
1370 static inline void skb_reset_mac_len(struct sk_buff *skb)
1372 skb->mac_len = skb->network_header - skb->mac_header;
1375 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1376 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1378 return skb->head + skb->transport_header;
1381 static inline void skb_reset_transport_header(struct sk_buff *skb)
1383 skb->transport_header = skb->data - skb->head;
1386 static inline void skb_set_transport_header(struct sk_buff *skb,
1389 skb_reset_transport_header(skb);
1390 skb->transport_header += offset;
1393 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1395 return skb->head + skb->network_header;
1398 static inline void skb_reset_network_header(struct sk_buff *skb)
1400 skb->network_header = skb->data - skb->head;
1403 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1405 skb_reset_network_header(skb);
1406 skb->network_header += offset;
1409 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1411 return skb->head + skb->mac_header;
1414 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1416 return skb->mac_header != ~0U;
1419 static inline void skb_reset_mac_header(struct sk_buff *skb)
1421 skb->mac_header = skb->data - skb->head;
1424 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1426 skb_reset_mac_header(skb);
1427 skb->mac_header += offset;
1430 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1432 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1434 return skb->transport_header;
1437 static inline void skb_reset_transport_header(struct sk_buff *skb)
1439 skb->transport_header = skb->data;
1442 static inline void skb_set_transport_header(struct sk_buff *skb,
1445 skb->transport_header = skb->data + offset;
1448 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1450 return skb->network_header;
1453 static inline void skb_reset_network_header(struct sk_buff *skb)
1455 skb->network_header = skb->data;
1458 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1460 skb->network_header = skb->data + offset;
1463 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1465 return skb->mac_header;
1468 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1470 return skb->mac_header != NULL;
1473 static inline void skb_reset_mac_header(struct sk_buff *skb)
1475 skb->mac_header = skb->data;
1478 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1480 skb->mac_header = skb->data + offset;
1482 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1484 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1486 if (skb_mac_header_was_set(skb)) {
1487 const unsigned char *old_mac = skb_mac_header(skb);
1489 skb_set_mac_header(skb, -skb->mac_len);
1490 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1494 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1496 return skb->csum_start - skb_headroom(skb);
1499 static inline int skb_transport_offset(const struct sk_buff *skb)
1501 return skb_transport_header(skb) - skb->data;
1504 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1506 return skb->transport_header - skb->network_header;
1509 static inline int skb_network_offset(const struct sk_buff *skb)
1511 return skb_network_header(skb) - skb->data;
1514 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1516 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1520 * CPUs often take a performance hit when accessing unaligned memory
1521 * locations. The actual performance hit varies, it can be small if the
1522 * hardware handles it or large if we have to take an exception and fix it
1525 * Since an ethernet header is 14 bytes network drivers often end up with
1526 * the IP header at an unaligned offset. The IP header can be aligned by
1527 * shifting the start of the packet by 2 bytes. Drivers should do this
1530 * skb_reserve(skb, NET_IP_ALIGN);
1532 * The downside to this alignment of the IP header is that the DMA is now
1533 * unaligned. On some architectures the cost of an unaligned DMA is high
1534 * and this cost outweighs the gains made by aligning the IP header.
1536 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1539 #ifndef NET_IP_ALIGN
1540 #define NET_IP_ALIGN 2
1544 * The networking layer reserves some headroom in skb data (via
1545 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1546 * the header has to grow. In the default case, if the header has to grow
1547 * 32 bytes or less we avoid the reallocation.
1549 * Unfortunately this headroom changes the DMA alignment of the resulting
1550 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1551 * on some architectures. An architecture can override this value,
1552 * perhaps setting it to a cacheline in size (since that will maintain
1553 * cacheline alignment of the DMA). It must be a power of 2.
1555 * Various parts of the networking layer expect at least 32 bytes of
1556 * headroom, you should not reduce this.
1558 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1559 * to reduce average number of cache lines per packet.
1560 * get_rps_cpus() for example only access one 64 bytes aligned block :
1561 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1564 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1567 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1569 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1571 if (unlikely(skb_is_nonlinear(skb))) {
1576 skb_set_tail_pointer(skb, len);
1579 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1581 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1584 return ___pskb_trim(skb, len);
1585 __skb_trim(skb, len);
1589 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1591 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1595 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1596 * @skb: buffer to alter
1599 * This is identical to pskb_trim except that the caller knows that
1600 * the skb is not cloned so we should never get an error due to out-
1603 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1605 int err = pskb_trim(skb, len);
1610 * skb_orphan - orphan a buffer
1611 * @skb: buffer to orphan
1613 * If a buffer currently has an owner then we call the owner's
1614 * destructor function and make the @skb unowned. The buffer continues
1615 * to exist but is no longer charged to its former owner.
1617 static inline void skb_orphan(struct sk_buff *skb)
1619 if (skb->destructor)
1620 skb->destructor(skb);
1621 skb->destructor = NULL;
1626 * __skb_queue_purge - empty a list
1627 * @list: list to empty
1629 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1630 * the list and one reference dropped. This function does not take the
1631 * list lock and the caller must hold the relevant locks to use it.
1633 extern void skb_queue_purge(struct sk_buff_head *list);
1634 static inline void __skb_queue_purge(struct sk_buff_head *list)
1636 struct sk_buff *skb;
1637 while ((skb = __skb_dequeue(list)) != NULL)
1642 * __dev_alloc_skb - allocate an skbuff for receiving
1643 * @length: length to allocate
1644 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1646 * Allocate a new &sk_buff and assign it a usage count of one. The
1647 * buffer has unspecified headroom built in. Users should allocate
1648 * the headroom they think they need without accounting for the
1649 * built in space. The built in space is used for optimisations.
1651 * %NULL is returned if there is no free memory.
1653 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1656 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1658 skb_reserve(skb, NET_SKB_PAD);
1662 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1664 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1665 unsigned int length, gfp_t gfp_mask);
1668 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1669 * @dev: network device to receive on
1670 * @length: length to allocate
1672 * Allocate a new &sk_buff and assign it a usage count of one. The
1673 * buffer has unspecified headroom built in. Users should allocate
1674 * the headroom they think they need without accounting for the
1675 * built in space. The built in space is used for optimisations.
1677 * %NULL is returned if there is no free memory. Although this function
1678 * allocates memory it can be called from an interrupt.
1680 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1681 unsigned int length)
1683 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1686 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1687 unsigned int length, gfp_t gfp)
1689 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1691 if (NET_IP_ALIGN && skb)
1692 skb_reserve(skb, NET_IP_ALIGN);
1696 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1697 unsigned int length)
1699 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1703 * __netdev_alloc_page - allocate a page for ps-rx on a specific device
1704 * @dev: network device to receive on
1705 * @gfp_mask: alloc_pages_node mask
1707 * Allocate a new page. dev currently unused.
1709 * %NULL is returned if there is no free memory.
1711 static inline struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
1713 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, 0);
1717 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1718 * @dev: network device to receive on
1720 * Allocate a new page. dev currently unused.
1722 * %NULL is returned if there is no free memory.
1724 static inline struct page *netdev_alloc_page(struct net_device *dev)
1726 return __netdev_alloc_page(dev, GFP_ATOMIC);
1729 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1735 * skb_frag_page - retrieve the page refered to by a paged fragment
1736 * @frag: the paged fragment
1738 * Returns the &struct page associated with @frag.
1740 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1742 return frag->page.p;
1746 * __skb_frag_ref - take an addition reference on a paged fragment.
1747 * @frag: the paged fragment
1749 * Takes an additional reference on the paged fragment @frag.
1751 static inline void __skb_frag_ref(skb_frag_t *frag)
1753 get_page(skb_frag_page(frag));
1757 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1759 * @f: the fragment offset.
1761 * Takes an additional reference on the @f'th paged fragment of @skb.
1763 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1765 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1769 * __skb_frag_unref - release a reference on a paged fragment.
1770 * @frag: the paged fragment
1772 * Releases a reference on the paged fragment @frag.
1774 static inline void __skb_frag_unref(skb_frag_t *frag)
1776 put_page(skb_frag_page(frag));
1780 * skb_frag_unref - release a reference on a paged fragment of an skb.
1782 * @f: the fragment offset
1784 * Releases a reference on the @f'th paged fragment of @skb.
1786 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1788 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1792 * skb_frag_address - gets the address of the data contained in a paged fragment
1793 * @frag: the paged fragment buffer
1795 * Returns the address of the data within @frag. The page must already
1798 static inline void *skb_frag_address(const skb_frag_t *frag)
1800 return page_address(skb_frag_page(frag)) + frag->page_offset;
1804 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1805 * @frag: the paged fragment buffer
1807 * Returns the address of the data within @frag. Checks that the page
1808 * is mapped and returns %NULL otherwise.
1810 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1812 void *ptr = page_address(skb_frag_page(frag));
1816 return ptr + frag->page_offset;
1820 * __skb_frag_set_page - sets the page contained in a paged fragment
1821 * @frag: the paged fragment
1822 * @page: the page to set
1824 * Sets the fragment @frag to contain @page.
1826 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1828 frag->page.p = page;
1832 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1834 * @f: the fragment offset
1835 * @page: the page to set
1837 * Sets the @f'th fragment of @skb to contain @page.
1839 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1842 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1846 * skb_frag_dma_map - maps a paged fragment via the DMA API
1847 * @dev: the device to map the fragment to
1848 * @frag: the paged fragment to map
1849 * @offset: the offset within the fragment (starting at the
1850 * fragment's own offset)
1851 * @size: the number of bytes to map
1852 * @dir: the direction of the mapping (%PCI_DMA_*)
1854 * Maps the page associated with @frag to @device.
1856 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1857 const skb_frag_t *frag,
1858 size_t offset, size_t size,
1859 enum dma_data_direction dir)
1861 return dma_map_page(dev, skb_frag_page(frag),
1862 frag->page_offset + offset, size, dir);
1866 * skb_clone_writable - is the header of a clone writable
1867 * @skb: buffer to check
1868 * @len: length up to which to write
1870 * Returns true if modifying the header part of the cloned buffer
1871 * does not requires the data to be copied.
1873 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1875 return !skb_header_cloned(skb) &&
1876 skb_headroom(skb) + len <= skb->hdr_len;
1879 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1884 if (headroom > skb_headroom(skb))
1885 delta = headroom - skb_headroom(skb);
1887 if (delta || cloned)
1888 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1894 * skb_cow - copy header of skb when it is required
1895 * @skb: buffer to cow
1896 * @headroom: needed headroom
1898 * If the skb passed lacks sufficient headroom or its data part
1899 * is shared, data is reallocated. If reallocation fails, an error
1900 * is returned and original skb is not changed.
1902 * The result is skb with writable area skb->head...skb->tail
1903 * and at least @headroom of space at head.
1905 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1907 return __skb_cow(skb, headroom, skb_cloned(skb));
1911 * skb_cow_head - skb_cow but only making the head writable
1912 * @skb: buffer to cow
1913 * @headroom: needed headroom
1915 * This function is identical to skb_cow except that we replace the
1916 * skb_cloned check by skb_header_cloned. It should be used when
1917 * you only need to push on some header and do not need to modify
1920 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1922 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1926 * skb_padto - pad an skbuff up to a minimal size
1927 * @skb: buffer to pad
1928 * @len: minimal length
1930 * Pads up a buffer to ensure the trailing bytes exist and are
1931 * blanked. If the buffer already contains sufficient data it
1932 * is untouched. Otherwise it is extended. Returns zero on
1933 * success. The skb is freed on error.
1936 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1938 unsigned int size = skb->len;
1939 if (likely(size >= len))
1941 return skb_pad(skb, len - size);
1944 static inline int skb_add_data(struct sk_buff *skb,
1945 char __user *from, int copy)
1947 const int off = skb->len;
1949 if (skb->ip_summed == CHECKSUM_NONE) {
1951 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1954 skb->csum = csum_block_add(skb->csum, csum, off);
1957 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1960 __skb_trim(skb, off);
1964 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1965 const struct page *page, int off)
1968 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1970 return page == skb_frag_page(frag) &&
1971 off == frag->page_offset + skb_frag_size(frag);
1976 static inline int __skb_linearize(struct sk_buff *skb)
1978 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1982 * skb_linearize - convert paged skb to linear one
1983 * @skb: buffer to linarize
1985 * If there is no free memory -ENOMEM is returned, otherwise zero
1986 * is returned and the old skb data released.
1988 static inline int skb_linearize(struct sk_buff *skb)
1990 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1994 * skb_linearize_cow - make sure skb is linear and writable
1995 * @skb: buffer to process
1997 * If there is no free memory -ENOMEM is returned, otherwise zero
1998 * is returned and the old skb data released.
2000 static inline int skb_linearize_cow(struct sk_buff *skb)
2002 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2003 __skb_linearize(skb) : 0;
2007 * skb_postpull_rcsum - update checksum for received skb after pull
2008 * @skb: buffer to update
2009 * @start: start of data before pull
2010 * @len: length of data pulled
2012 * After doing a pull on a received packet, you need to call this to
2013 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2014 * CHECKSUM_NONE so that it can be recomputed from scratch.
2017 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2018 const void *start, unsigned int len)
2020 if (skb->ip_summed == CHECKSUM_COMPLETE)
2021 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2024 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2027 * pskb_trim_rcsum - trim received skb and update checksum
2028 * @skb: buffer to trim
2031 * This is exactly the same as pskb_trim except that it ensures the
2032 * checksum of received packets are still valid after the operation.
2035 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2037 if (likely(len >= skb->len))
2039 if (skb->ip_summed == CHECKSUM_COMPLETE)
2040 skb->ip_summed = CHECKSUM_NONE;
2041 return __pskb_trim(skb, len);
2044 #define skb_queue_walk(queue, skb) \
2045 for (skb = (queue)->next; \
2046 skb != (struct sk_buff *)(queue); \
2049 #define skb_queue_walk_safe(queue, skb, tmp) \
2050 for (skb = (queue)->next, tmp = skb->next; \
2051 skb != (struct sk_buff *)(queue); \
2052 skb = tmp, tmp = skb->next)
2054 #define skb_queue_walk_from(queue, skb) \
2055 for (; skb != (struct sk_buff *)(queue); \
2058 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2059 for (tmp = skb->next; \
2060 skb != (struct sk_buff *)(queue); \
2061 skb = tmp, tmp = skb->next)
2063 #define skb_queue_reverse_walk(queue, skb) \
2064 for (skb = (queue)->prev; \
2065 skb != (struct sk_buff *)(queue); \
2068 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2069 for (skb = (queue)->prev, tmp = skb->prev; \
2070 skb != (struct sk_buff *)(queue); \
2071 skb = tmp, tmp = skb->prev)
2073 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2074 for (tmp = skb->prev; \
2075 skb != (struct sk_buff *)(queue); \
2076 skb = tmp, tmp = skb->prev)
2078 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2080 return skb_shinfo(skb)->frag_list != NULL;
2083 static inline void skb_frag_list_init(struct sk_buff *skb)
2085 skb_shinfo(skb)->frag_list = NULL;
2088 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2090 frag->next = skb_shinfo(skb)->frag_list;
2091 skb_shinfo(skb)->frag_list = frag;
2094 #define skb_walk_frags(skb, iter) \
2095 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2097 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2098 int *peeked, int *err);
2099 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2100 int noblock, int *err);
2101 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2102 struct poll_table_struct *wait);
2103 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2104 int offset, struct iovec *to,
2106 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2109 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2111 const struct iovec *from,
2114 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2116 const struct iovec *to,
2119 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2120 extern void skb_free_datagram_locked(struct sock *sk,
2121 struct sk_buff *skb);
2122 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2123 unsigned int flags);
2124 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2125 int len, __wsum csum);
2126 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2128 extern int skb_store_bits(struct sk_buff *skb, int offset,
2129 const void *from, int len);
2130 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2131 int offset, u8 *to, int len,
2133 extern int skb_splice_bits(struct sk_buff *skb,
2134 unsigned int offset,
2135 struct pipe_inode_info *pipe,
2137 unsigned int flags);
2138 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2139 extern void skb_split(struct sk_buff *skb,
2140 struct sk_buff *skb1, const u32 len);
2141 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2144 extern struct sk_buff *skb_segment(struct sk_buff *skb, u32 features);
2146 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
2148 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2149 int len, void *buffer)
2151 int hlen = skb_headlen(skb);
2153 if (hlen - offset >= len)
2154 return skb->data + offset;
2156 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2162 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2164 const unsigned int len)
2166 memcpy(to, skb->data, len);
2169 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2170 const int offset, void *to,
2171 const unsigned int len)
2173 memcpy(to, skb->data + offset, len);
2176 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2178 const unsigned int len)
2180 memcpy(skb->data, from, len);
2183 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2186 const unsigned int len)
2188 memcpy(skb->data + offset, from, len);
2191 extern void skb_init(void);
2193 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2199 * skb_get_timestamp - get timestamp from a skb
2200 * @skb: skb to get stamp from
2201 * @stamp: pointer to struct timeval to store stamp in
2203 * Timestamps are stored in the skb as offsets to a base timestamp.
2204 * This function converts the offset back to a struct timeval and stores
2207 static inline void skb_get_timestamp(const struct sk_buff *skb,
2208 struct timeval *stamp)
2210 *stamp = ktime_to_timeval(skb->tstamp);
2213 static inline void skb_get_timestampns(const struct sk_buff *skb,
2214 struct timespec *stamp)
2216 *stamp = ktime_to_timespec(skb->tstamp);
2219 static inline void __net_timestamp(struct sk_buff *skb)
2221 skb->tstamp = ktime_get_real();
2224 static inline ktime_t net_timedelta(ktime_t t)
2226 return ktime_sub(ktime_get_real(), t);
2229 static inline ktime_t net_invalid_timestamp(void)
2231 return ktime_set(0, 0);
2234 extern void skb_timestamping_init(void);
2236 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2238 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2239 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2241 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2243 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2247 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2252 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2255 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2257 * PHY drivers may accept clones of transmitted packets for
2258 * timestamping via their phy_driver.txtstamp method. These drivers
2259 * must call this function to return the skb back to the stack, with
2260 * or without a timestamp.
2262 * @skb: clone of the the original outgoing packet
2263 * @hwtstamps: hardware time stamps, may be NULL if not available
2266 void skb_complete_tx_timestamp(struct sk_buff *skb,
2267 struct skb_shared_hwtstamps *hwtstamps);
2270 * skb_tstamp_tx - queue clone of skb with send time stamps
2271 * @orig_skb: the original outgoing packet
2272 * @hwtstamps: hardware time stamps, may be NULL if not available
2274 * If the skb has a socket associated, then this function clones the
2275 * skb (thus sharing the actual data and optional structures), stores
2276 * the optional hardware time stamping information (if non NULL) or
2277 * generates a software time stamp (otherwise), then queues the clone
2278 * to the error queue of the socket. Errors are silently ignored.
2280 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2281 struct skb_shared_hwtstamps *hwtstamps);
2283 static inline void sw_tx_timestamp(struct sk_buff *skb)
2285 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2286 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2287 skb_tstamp_tx(skb, NULL);
2291 * skb_tx_timestamp() - Driver hook for transmit timestamping
2293 * Ethernet MAC Drivers should call this function in their hard_xmit()
2294 * function immediately before giving the sk_buff to the MAC hardware.
2296 * @skb: A socket buffer.
2298 static inline void skb_tx_timestamp(struct sk_buff *skb)
2300 skb_clone_tx_timestamp(skb);
2301 sw_tx_timestamp(skb);
2304 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2305 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2307 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2309 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2313 * skb_checksum_complete - Calculate checksum of an entire packet
2314 * @skb: packet to process
2316 * This function calculates the checksum over the entire packet plus
2317 * the value of skb->csum. The latter can be used to supply the
2318 * checksum of a pseudo header as used by TCP/UDP. It returns the
2321 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2322 * this function can be used to verify that checksum on received
2323 * packets. In that case the function should return zero if the
2324 * checksum is correct. In particular, this function will return zero
2325 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2326 * hardware has already verified the correctness of the checksum.
2328 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2330 return skb_csum_unnecessary(skb) ?
2331 0 : __skb_checksum_complete(skb);
2334 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2335 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2336 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2338 if (nfct && atomic_dec_and_test(&nfct->use))
2339 nf_conntrack_destroy(nfct);
2341 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2344 atomic_inc(&nfct->use);
2347 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2348 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2351 atomic_inc(&skb->users);
2353 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2359 #ifdef CONFIG_BRIDGE_NETFILTER
2360 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2362 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2365 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2368 atomic_inc(&nf_bridge->use);
2370 #endif /* CONFIG_BRIDGE_NETFILTER */
2371 static inline void nf_reset(struct sk_buff *skb)
2373 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2374 nf_conntrack_put(skb->nfct);
2377 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2378 nf_conntrack_put_reasm(skb->nfct_reasm);
2379 skb->nfct_reasm = NULL;
2381 #ifdef CONFIG_BRIDGE_NETFILTER
2382 nf_bridge_put(skb->nf_bridge);
2383 skb->nf_bridge = NULL;
2387 static inline void nf_reset_trace(struct sk_buff *skb)
2389 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
2394 /* Note: This doesn't put any conntrack and bridge info in dst. */
2395 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2397 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2398 dst->nfct = src->nfct;
2399 nf_conntrack_get(src->nfct);
2400 dst->nfctinfo = src->nfctinfo;
2402 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2403 dst->nfct_reasm = src->nfct_reasm;
2404 nf_conntrack_get_reasm(src->nfct_reasm);
2406 #ifdef CONFIG_BRIDGE_NETFILTER
2407 dst->nf_bridge = src->nf_bridge;
2408 nf_bridge_get(src->nf_bridge);
2412 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2414 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2415 nf_conntrack_put(dst->nfct);
2417 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2418 nf_conntrack_put_reasm(dst->nfct_reasm);
2420 #ifdef CONFIG_BRIDGE_NETFILTER
2421 nf_bridge_put(dst->nf_bridge);
2423 __nf_copy(dst, src);
2426 #ifdef CONFIG_NETWORK_SECMARK
2427 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2429 to->secmark = from->secmark;
2432 static inline void skb_init_secmark(struct sk_buff *skb)
2437 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2440 static inline void skb_init_secmark(struct sk_buff *skb)
2444 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2446 skb->queue_mapping = queue_mapping;
2449 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2451 return skb->queue_mapping;
2454 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2456 to->queue_mapping = from->queue_mapping;
2459 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2461 skb->queue_mapping = rx_queue + 1;
2464 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2466 return skb->queue_mapping - 1;
2469 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2471 return skb->queue_mapping != 0;
2474 extern u16 __skb_tx_hash(const struct net_device *dev,
2475 const struct sk_buff *skb,
2476 unsigned int num_tx_queues);
2479 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2484 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2490 static inline int skb_is_gso(const struct sk_buff *skb)
2492 return skb_shinfo(skb)->gso_size;
2495 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2497 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2500 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2502 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2504 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2505 * wanted then gso_type will be set. */
2506 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2508 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2509 unlikely(shinfo->gso_type == 0)) {
2510 __skb_warn_lro_forwarding(skb);
2516 static inline void skb_forward_csum(struct sk_buff *skb)
2518 /* Unfortunately we don't support this one. Any brave souls? */
2519 if (skb->ip_summed == CHECKSUM_COMPLETE)
2520 skb->ip_summed = CHECKSUM_NONE;
2524 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2525 * @skb: skb to check
2527 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2528 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2529 * use this helper, to document places where we make this assertion.
2531 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2534 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2538 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2540 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2542 if (irqs_disabled())
2545 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2548 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2551 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2552 if (skb_end_pointer(skb) - skb->head < skb_size)
2555 if (skb_shared(skb) || skb_cloned(skb))
2562 * skb_gso_network_seglen - Return length of individual segments of a gso packet
2566 * skb_gso_network_seglen is used to determine the real size of the
2567 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
2569 * The MAC/L2 header is not accounted for.
2571 static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
2573 unsigned int hdr_len = skb_transport_header(skb) -
2574 skb_network_header(skb);
2575 return hdr_len + skb_gso_transport_seglen(skb);
2577 #endif /* __KERNEL__ */
2578 #endif /* _LINUX_SKBUFF_H */