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 <linux/sched.h>
36 #include <net/flow_keys.h>
38 /* A. Checksumming of received packets by device.
42 * Device failed to checksum this packet e.g. due to lack of capabilities.
43 * The packet contains full (though not verified) checksum in packet but
44 * not in skb->csum. Thus, skb->csum is undefined in this case.
46 * CHECKSUM_UNNECESSARY:
48 * The hardware you're dealing with doesn't calculate the full checksum
49 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
50 * for specific protocols e.g. TCP/UDP/SCTP, then, for such packets it will
51 * set CHECKSUM_UNNECESSARY if their checksums are okay. skb->csum is still
52 * undefined in this case though. It is a bad option, but, unfortunately,
53 * nowadays most vendors do this. Apparently with the secret goal to sell
54 * you new devices, when you will add new protocol to your host, f.e. IPv6 8)
58 * This is the most generic way. The device supplied checksum of the _whole_
59 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
60 * hardware doesn't need to parse L3/L4 headers to implement this.
62 * Note: Even if device supports only some protocols, but is able to produce
63 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
67 * This is identical to the case for output below. This may occur on a packet
68 * received directly from another Linux OS, e.g., a virtualized Linux kernel
69 * on the same host. The packet can be treated in the same way as
70 * CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the
71 * checksum must be filled in by the OS or the hardware.
73 * B. Checksumming on output.
77 * The skb was already checksummed by the protocol, or a checksum is not
82 * The device is required to checksum the packet as seen by hard_start_xmit()
83 * from skb->csum_start up to the end, and to record/write the checksum at
84 * offset skb->csum_start + skb->csum_offset.
86 * The device must show its capabilities in dev->features, set up at device
87 * setup time, e.g. netdev_features.h:
89 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
90 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
91 * IPv4. Sigh. Vendors like this way for an unknown reason.
92 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
93 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
94 * NETIF_F_... - Well, you get the picture.
96 * CHECKSUM_UNNECESSARY:
98 * Normally, the device will do per protocol specific checksumming. Protocol
99 * implementations that do not want the NIC to perform the checksum
100 * calculation should use this flag in their outgoing skbs.
102 * NETIF_F_FCOE_CRC - This indicates that 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
109 /* Don't change this without changing skb_csum_unnecessary! */
110 #define CHECKSUM_NONE 0
111 #define CHECKSUM_UNNECESSARY 1
112 #define CHECKSUM_COMPLETE 2
113 #define CHECKSUM_PARTIAL 3
115 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
116 ~(SMP_CACHE_BYTES - 1))
117 #define SKB_WITH_OVERHEAD(X) \
118 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
119 #define SKB_MAX_ORDER(X, ORDER) \
120 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
121 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
122 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
124 /* return minimum truesize of one skb containing X bytes of data */
125 #define SKB_TRUESIZE(X) ((X) + \
126 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
127 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
131 struct pipe_inode_info
;
133 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
134 struct nf_conntrack
{
139 #ifdef CONFIG_BRIDGE_NETFILTER
140 struct nf_bridge_info
{
143 struct net_device
*physindev
;
144 struct net_device
*physoutdev
;
145 unsigned long data
[32 / sizeof(unsigned long)];
149 struct sk_buff_head
{
150 /* These two members must be first. */
151 struct sk_buff
*next
;
152 struct sk_buff
*prev
;
160 /* To allow 64K frame to be packed as single skb without frag_list we
161 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
162 * buffers which do not start on a page boundary.
164 * Since GRO uses frags we allocate at least 16 regardless of page
167 #if (65536/PAGE_SIZE + 1) < 16
168 #define MAX_SKB_FRAGS 16UL
170 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
173 typedef struct skb_frag_struct skb_frag_t
;
175 struct skb_frag_struct
{
179 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
188 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
193 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
198 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
203 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
208 #define HAVE_HW_TIME_STAMP
211 * struct skb_shared_hwtstamps - hardware time stamps
212 * @hwtstamp: hardware time stamp transformed into duration
213 * since arbitrary point in time
214 * @syststamp: hwtstamp transformed to system time base
216 * Software time stamps generated by ktime_get_real() are stored in
217 * skb->tstamp. The relation between the different kinds of time
218 * stamps is as follows:
220 * syststamp and tstamp can be compared against each other in
221 * arbitrary combinations. The accuracy of a
222 * syststamp/tstamp/"syststamp from other device" comparison is
223 * limited by the accuracy of the transformation into system time
224 * base. This depends on the device driver and its underlying
227 * hwtstamps can only be compared against other hwtstamps from
230 * This structure is attached to packets as part of the
231 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
233 struct skb_shared_hwtstamps
{
238 /* Definitions for tx_flags in struct skb_shared_info */
240 /* generate hardware time stamp */
241 SKBTX_HW_TSTAMP
= 1 << 0,
243 /* generate software time stamp */
244 SKBTX_SW_TSTAMP
= 1 << 1,
246 /* device driver is going to provide hardware time stamp */
247 SKBTX_IN_PROGRESS
= 1 << 2,
249 /* device driver supports TX zero-copy buffers */
250 SKBTX_DEV_ZEROCOPY
= 1 << 3,
252 /* generate wifi status information (where possible) */
253 SKBTX_WIFI_STATUS
= 1 << 4,
255 /* This indicates at least one fragment might be overwritten
256 * (as in vmsplice(), sendfile() ...)
257 * If we need to compute a TX checksum, we'll need to copy
258 * all frags to avoid possible bad checksum
260 SKBTX_SHARED_FRAG
= 1 << 5,
264 * The callback notifies userspace to release buffers when skb DMA is done in
265 * lower device, the skb last reference should be 0 when calling this.
266 * The zerocopy_success argument is true if zero copy transmit occurred,
267 * false on data copy or out of memory error caused by data copy attempt.
268 * The ctx field is used to track device context.
269 * The desc field is used to track userspace buffer index.
272 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
277 /* This data is invariant across clones and lives at
278 * the end of the header data, ie. at skb->end.
280 struct skb_shared_info
{
281 unsigned char nr_frags
;
283 unsigned short gso_size
;
284 /* Warning: this field is not always filled in (UFO)! */
285 unsigned short gso_segs
;
286 unsigned short gso_type
;
287 struct sk_buff
*frag_list
;
288 struct skb_shared_hwtstamps hwtstamps
;
292 * Warning : all fields before dataref are cleared in __alloc_skb()
296 /* Intermediate layers must ensure that destructor_arg
297 * remains valid until skb destructor */
298 void * destructor_arg
;
300 /* must be last field, see pskb_expand_head() */
301 skb_frag_t frags
[MAX_SKB_FRAGS
];
304 /* We divide dataref into two halves. The higher 16 bits hold references
305 * to the payload part of skb->data. The lower 16 bits hold references to
306 * the entire skb->data. A clone of a headerless skb holds the length of
307 * the header in skb->hdr_len.
309 * All users must obey the rule that the skb->data reference count must be
310 * greater than or equal to the payload reference count.
312 * Holding a reference to the payload part means that the user does not
313 * care about modifications to the header part of skb->data.
315 #define SKB_DATAREF_SHIFT 16
316 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
320 SKB_FCLONE_UNAVAILABLE
,
326 SKB_GSO_TCPV4
= 1 << 0,
327 SKB_GSO_UDP
= 1 << 1,
329 /* This indicates the skb is from an untrusted source. */
330 SKB_GSO_DODGY
= 1 << 2,
332 /* This indicates the tcp segment has CWR set. */
333 SKB_GSO_TCP_ECN
= 1 << 3,
335 SKB_GSO_TCPV6
= 1 << 4,
337 SKB_GSO_FCOE
= 1 << 5,
339 SKB_GSO_GRE
= 1 << 6,
341 SKB_GSO_IPIP
= 1 << 7,
343 SKB_GSO_SIT
= 1 << 8,
345 SKB_GSO_UDP_TUNNEL
= 1 << 9,
347 SKB_GSO_MPLS
= 1 << 10,
349 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
351 SKB_GSO_GRE_CSUM
= 1 << 12,
354 #if BITS_PER_LONG > 32
355 #define NET_SKBUFF_DATA_USES_OFFSET 1
358 #ifdef NET_SKBUFF_DATA_USES_OFFSET
359 typedef unsigned int sk_buff_data_t
;
361 typedef unsigned char *sk_buff_data_t
;
365 * struct skb_mstamp - multi resolution time stamps
366 * @stamp_us: timestamp in us resolution
367 * @stamp_jiffies: timestamp in jiffies
380 * skb_mstamp_get - get current timestamp
381 * @cl: place to store timestamps
383 static inline void skb_mstamp_get(struct skb_mstamp
*cl
)
385 u64 val
= local_clock();
387 do_div(val
, NSEC_PER_USEC
);
388 cl
->stamp_us
= (u32
)val
;
389 cl
->stamp_jiffies
= (u32
)jiffies
;
393 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
394 * @t1: pointer to newest sample
395 * @t0: pointer to oldest sample
397 static inline u32
skb_mstamp_us_delta(const struct skb_mstamp
*t1
,
398 const struct skb_mstamp
*t0
)
400 s32 delta_us
= t1
->stamp_us
- t0
->stamp_us
;
401 u32 delta_jiffies
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
403 /* If delta_us is negative, this might be because interval is too big,
404 * or local_clock() drift is too big : fallback using jiffies.
407 delta_jiffies
>= (INT_MAX
/ (USEC_PER_SEC
/ HZ
)))
409 delta_us
= jiffies_to_usecs(delta_jiffies
);
416 * struct sk_buff - socket buffer
417 * @next: Next buffer in list
418 * @prev: Previous buffer in list
419 * @tstamp: Time we arrived/left
420 * @sk: Socket we are owned by
421 * @dev: Device we arrived on/are leaving by
422 * @cb: Control buffer. Free for use by every layer. Put private vars here
423 * @_skb_refdst: destination entry (with norefcount bit)
424 * @sp: the security path, used for xfrm
425 * @len: Length of actual data
426 * @data_len: Data length
427 * @mac_len: Length of link layer header
428 * @hdr_len: writable header length of cloned skb
429 * @csum: Checksum (must include start/offset pair)
430 * @csum_start: Offset from skb->head where checksumming should start
431 * @csum_offset: Offset from csum_start where checksum should be stored
432 * @priority: Packet queueing priority
433 * @ignore_df: allow local fragmentation
434 * @cloned: Head may be cloned (check refcnt to be sure)
435 * @ip_summed: Driver fed us an IP checksum
436 * @nohdr: Payload reference only, must not modify header
437 * @nfctinfo: Relationship of this skb to the connection
438 * @pkt_type: Packet class
439 * @fclone: skbuff clone status
440 * @ipvs_property: skbuff is owned by ipvs
441 * @peeked: this packet has been seen already, so stats have been
442 * done for it, don't do them again
443 * @nf_trace: netfilter packet trace flag
444 * @protocol: Packet protocol from driver
445 * @destructor: Destruct function
446 * @nfct: Associated connection, if any
447 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
448 * @skb_iif: ifindex of device we arrived on
449 * @tc_index: Traffic control index
450 * @tc_verd: traffic control verdict
451 * @hash: the packet hash
452 * @queue_mapping: Queue mapping for multiqueue devices
453 * @ndisc_nodetype: router type (from link layer)
454 * @ooo_okay: allow the mapping of a socket to a queue to be changed
455 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
457 * @wifi_acked_valid: wifi_acked was set
458 * @wifi_acked: whether frame was acked on wifi or not
459 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
460 * @dma_cookie: a cookie to one of several possible DMA operations
461 * done by skb DMA functions
462 * @napi_id: id of the NAPI struct this skb came from
463 * @secmark: security marking
464 * @mark: Generic packet mark
465 * @dropcount: total number of sk_receive_queue overflows
466 * @vlan_proto: vlan encapsulation protocol
467 * @vlan_tci: vlan tag control information
468 * @inner_protocol: Protocol (encapsulation)
469 * @inner_transport_header: Inner transport layer header (encapsulation)
470 * @inner_network_header: Network layer header (encapsulation)
471 * @inner_mac_header: Link layer header (encapsulation)
472 * @transport_header: Transport layer header
473 * @network_header: Network layer header
474 * @mac_header: Link layer header
475 * @tail: Tail pointer
477 * @head: Head of buffer
478 * @data: Data head pointer
479 * @truesize: Buffer size
480 * @users: User count - see {datagram,tcp}.c
484 /* These two members must be first. */
485 struct sk_buff
*next
;
486 struct sk_buff
*prev
;
490 struct skb_mstamp skb_mstamp
;
494 struct net_device
*dev
;
497 * This is the control buffer. It is free to use for every
498 * layer. Please put your private variables there. If you
499 * want to keep them across layers you have to do a skb_clone()
500 * first. This is owned by whoever has the skb queued ATM.
502 char cb
[48] __aligned(8);
504 unsigned long _skb_refdst
;
520 kmemcheck_bitfield_begin(flags1
);
531 kmemcheck_bitfield_end(flags1
);
534 void (*destructor
)(struct sk_buff
*skb
);
535 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
536 struct nf_conntrack
*nfct
;
538 #ifdef CONFIG_BRIDGE_NETFILTER
539 struct nf_bridge_info
*nf_bridge
;
549 #ifdef CONFIG_NET_SCHED
550 __u16 tc_index
; /* traffic control index */
551 #ifdef CONFIG_NET_CLS_ACT
552 __u16 tc_verd
; /* traffic control verdict */
557 kmemcheck_bitfield_begin(flags2
);
558 #ifdef CONFIG_IPV6_NDISC_NODETYPE
559 __u8 ndisc_nodetype
:2;
564 __u8 wifi_acked_valid
:1;
568 /* Encapsulation protocol and NIC drivers should use
569 * this flag to indicate to each other if the skb contains
570 * encapsulated packet or not and maybe use the inner packet
573 __u8 encapsulation
:1;
574 __u8 encap_hdr_csum
:1;
576 __u8 csum_complete_sw
:1;
577 /* 3/5 bit hole (depending on ndisc_nodetype presence) */
578 kmemcheck_bitfield_end(flags2
);
580 #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL
582 unsigned int napi_id
;
583 dma_cookie_t dma_cookie
;
586 #ifdef CONFIG_NETWORK_SECMARK
592 __u32 reserved_tailroom
;
595 __be16 inner_protocol
;
596 __u16 inner_transport_header
;
597 __u16 inner_network_header
;
598 __u16 inner_mac_header
;
599 __u16 transport_header
;
600 __u16 network_header
;
602 /* These elements must be at the end, see alloc_skb() for details. */
607 unsigned int truesize
;
613 * Handling routines are only of interest to the kernel
615 #include <linux/slab.h>
618 #define SKB_ALLOC_FCLONE 0x01
619 #define SKB_ALLOC_RX 0x02
621 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
622 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
624 return unlikely(skb
->pfmemalloc
);
628 * skb might have a dst pointer attached, refcounted or not.
629 * _skb_refdst low order bit is set if refcount was _not_ taken
631 #define SKB_DST_NOREF 1UL
632 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
635 * skb_dst - returns skb dst_entry
638 * Returns skb dst_entry, regardless of reference taken or not.
640 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
642 /* If refdst was not refcounted, check we still are in a
643 * rcu_read_lock section
645 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
646 !rcu_read_lock_held() &&
647 !rcu_read_lock_bh_held());
648 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
652 * skb_dst_set - sets skb dst
656 * Sets skb dst, assuming a reference was taken on dst and should
657 * be released by skb_dst_drop()
659 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
661 skb
->_skb_refdst
= (unsigned long)dst
;
664 void __skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
,
668 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
672 * Sets skb dst, assuming a reference was not taken on dst.
673 * If dst entry is cached, we do not take reference and dst_release
674 * will be avoided by refdst_drop. If dst entry is not cached, we take
675 * reference, so that last dst_release can destroy the dst immediately.
677 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
679 __skb_dst_set_noref(skb
, dst
, false);
683 * skb_dst_set_noref_force - sets skb dst, without taking reference
687 * Sets skb dst, assuming a reference was not taken on dst.
688 * No reference is taken and no dst_release will be called. While for
689 * cached dsts deferred reclaim is a basic feature, for entries that are
690 * not cached it is caller's job to guarantee that last dst_release for
691 * provided dst happens when nobody uses it, eg. after a RCU grace period.
693 static inline void skb_dst_set_noref_force(struct sk_buff
*skb
,
694 struct dst_entry
*dst
)
696 __skb_dst_set_noref(skb
, dst
, true);
700 * skb_dst_is_noref - Test if skb dst isn't refcounted
703 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
705 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
708 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
710 return (struct rtable
*)skb_dst(skb
);
713 void kfree_skb(struct sk_buff
*skb
);
714 void kfree_skb_list(struct sk_buff
*segs
);
715 void skb_tx_error(struct sk_buff
*skb
);
716 void consume_skb(struct sk_buff
*skb
);
717 void __kfree_skb(struct sk_buff
*skb
);
718 extern struct kmem_cache
*skbuff_head_cache
;
720 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
721 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
722 bool *fragstolen
, int *delta_truesize
);
724 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
726 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
727 static inline struct sk_buff
*alloc_skb(unsigned int size
,
730 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
733 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
736 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
739 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
740 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
742 return __alloc_skb_head(priority
, -1);
745 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
746 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
747 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
748 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
749 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
750 gfp_t gfp_mask
, bool fclone
);
751 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
754 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
757 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
758 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
759 unsigned int headroom
);
760 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
761 int newtailroom
, gfp_t priority
);
762 int skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
763 int offset
, int len
);
764 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
,
766 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
767 int skb_pad(struct sk_buff
*skb
, int pad
);
768 #define dev_kfree_skb(a) consume_skb(a)
770 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
771 int getfrag(void *from
, char *to
, int offset
,
772 int len
, int odd
, struct sk_buff
*skb
),
773 void *from
, int length
);
775 struct skb_seq_state
{
779 __u32 stepped_offset
;
780 struct sk_buff
*root_skb
;
781 struct sk_buff
*cur_skb
;
785 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
786 unsigned int to
, struct skb_seq_state
*st
);
787 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
788 struct skb_seq_state
*st
);
789 void skb_abort_seq_read(struct skb_seq_state
*st
);
791 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
792 unsigned int to
, struct ts_config
*config
,
793 struct ts_state
*state
);
796 * Packet hash types specify the type of hash in skb_set_hash.
798 * Hash types refer to the protocol layer addresses which are used to
799 * construct a packet's hash. The hashes are used to differentiate or identify
800 * flows of the protocol layer for the hash type. Hash types are either
801 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
803 * Properties of hashes:
805 * 1) Two packets in different flows have different hash values
806 * 2) Two packets in the same flow should have the same hash value
808 * A hash at a higher layer is considered to be more specific. A driver should
809 * set the most specific hash possible.
811 * A driver cannot indicate a more specific hash than the layer at which a hash
812 * was computed. For instance an L3 hash cannot be set as an L4 hash.
814 * A driver may indicate a hash level which is less specific than the
815 * actual layer the hash was computed on. For instance, a hash computed
816 * at L4 may be considered an L3 hash. This should only be done if the
817 * driver can't unambiguously determine that the HW computed the hash at
818 * the higher layer. Note that the "should" in the second property above
821 enum pkt_hash_types
{
822 PKT_HASH_TYPE_NONE
, /* Undefined type */
823 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
824 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
825 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
829 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
831 skb
->l4_hash
= (type
== PKT_HASH_TYPE_L4
);
835 void __skb_get_hash(struct sk_buff
*skb
);
836 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
844 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
849 static inline void skb_clear_hash(struct sk_buff
*skb
)
855 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
861 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
863 to
->hash
= from
->hash
;
864 to
->l4_hash
= from
->l4_hash
;
867 #ifdef NET_SKBUFF_DATA_USES_OFFSET
868 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
870 return skb
->head
+ skb
->end
;
873 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
878 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
883 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
885 return skb
->end
- skb
->head
;
890 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
892 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
894 return &skb_shinfo(skb
)->hwtstamps
;
898 * skb_queue_empty - check if a queue is empty
901 * Returns true if the queue is empty, false otherwise.
903 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
905 return list
->next
== (const struct sk_buff
*) list
;
909 * skb_queue_is_last - check if skb is the last entry in the queue
913 * Returns true if @skb is the last buffer on the list.
915 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
916 const struct sk_buff
*skb
)
918 return skb
->next
== (const struct sk_buff
*) list
;
922 * skb_queue_is_first - check if skb is the first entry in the queue
926 * Returns true if @skb is the first buffer on the list.
928 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
929 const struct sk_buff
*skb
)
931 return skb
->prev
== (const struct sk_buff
*) list
;
935 * skb_queue_next - return the next packet in the queue
937 * @skb: current buffer
939 * Return the next packet in @list after @skb. It is only valid to
940 * call this if skb_queue_is_last() evaluates to false.
942 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
943 const struct sk_buff
*skb
)
945 /* This BUG_ON may seem severe, but if we just return then we
946 * are going to dereference garbage.
948 BUG_ON(skb_queue_is_last(list
, skb
));
953 * skb_queue_prev - return the prev packet in the queue
955 * @skb: current buffer
957 * Return the prev packet in @list before @skb. It is only valid to
958 * call this if skb_queue_is_first() evaluates to false.
960 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
961 const struct sk_buff
*skb
)
963 /* This BUG_ON may seem severe, but if we just return then we
964 * are going to dereference garbage.
966 BUG_ON(skb_queue_is_first(list
, skb
));
971 * skb_get - reference buffer
972 * @skb: buffer to reference
974 * Makes another reference to a socket buffer and returns a pointer
977 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
979 atomic_inc(&skb
->users
);
984 * If users == 1, we are the only owner and are can avoid redundant
989 * skb_cloned - is the buffer a clone
990 * @skb: buffer to check
992 * Returns true if the buffer was generated with skb_clone() and is
993 * one of multiple shared copies of the buffer. Cloned buffers are
994 * shared data so must not be written to under normal circumstances.
996 static inline int skb_cloned(const struct sk_buff
*skb
)
998 return skb
->cloned
&&
999 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1002 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1004 might_sleep_if(pri
& __GFP_WAIT
);
1006 if (skb_cloned(skb
))
1007 return pskb_expand_head(skb
, 0, 0, pri
);
1013 * skb_header_cloned - is the header a clone
1014 * @skb: buffer to check
1016 * Returns true if modifying the header part of the buffer requires
1017 * the data to be copied.
1019 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1026 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1027 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1028 return dataref
!= 1;
1032 * skb_header_release - release reference to header
1033 * @skb: buffer to operate on
1035 * Drop a reference to the header part of the buffer. This is done
1036 * by acquiring a payload reference. You must not read from the header
1037 * part of skb->data after this.
1039 static inline void skb_header_release(struct sk_buff
*skb
)
1043 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1047 * skb_shared - is the buffer shared
1048 * @skb: buffer to check
1050 * Returns true if more than one person has a reference to this
1053 static inline int skb_shared(const struct sk_buff
*skb
)
1055 return atomic_read(&skb
->users
) != 1;
1059 * skb_share_check - check if buffer is shared and if so clone it
1060 * @skb: buffer to check
1061 * @pri: priority for memory allocation
1063 * If the buffer is shared the buffer is cloned and the old copy
1064 * drops a reference. A new clone with a single reference is returned.
1065 * If the buffer is not shared the original buffer is returned. When
1066 * being called from interrupt status or with spinlocks held pri must
1069 * NULL is returned on a memory allocation failure.
1071 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1073 might_sleep_if(pri
& __GFP_WAIT
);
1074 if (skb_shared(skb
)) {
1075 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1087 * Copy shared buffers into a new sk_buff. We effectively do COW on
1088 * packets to handle cases where we have a local reader and forward
1089 * and a couple of other messy ones. The normal one is tcpdumping
1090 * a packet thats being forwarded.
1094 * skb_unshare - make a copy of a shared buffer
1095 * @skb: buffer to check
1096 * @pri: priority for memory allocation
1098 * If the socket buffer is a clone then this function creates a new
1099 * copy of the data, drops a reference count on the old copy and returns
1100 * the new copy with the reference count at 1. If the buffer is not a clone
1101 * the original buffer is returned. When called with a spinlock held or
1102 * from interrupt state @pri must be %GFP_ATOMIC
1104 * %NULL is returned on a memory allocation failure.
1106 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1109 might_sleep_if(pri
& __GFP_WAIT
);
1110 if (skb_cloned(skb
)) {
1111 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1112 kfree_skb(skb
); /* Free our shared copy */
1119 * skb_peek - peek at the head of an &sk_buff_head
1120 * @list_: list to peek at
1122 * Peek an &sk_buff. Unlike most other operations you _MUST_
1123 * be careful with this one. A peek leaves the buffer on the
1124 * list and someone else may run off with it. You must hold
1125 * the appropriate locks or have a private queue to do this.
1127 * Returns %NULL for an empty list or a pointer to the head element.
1128 * The reference count is not incremented and the reference is therefore
1129 * volatile. Use with caution.
1131 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1133 struct sk_buff
*skb
= list_
->next
;
1135 if (skb
== (struct sk_buff
*)list_
)
1141 * skb_peek_next - peek skb following the given one from a queue
1142 * @skb: skb to start from
1143 * @list_: list to peek at
1145 * Returns %NULL when the end of the list is met or a pointer to the
1146 * next element. The reference count is not incremented and the
1147 * reference is therefore volatile. Use with caution.
1149 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1150 const struct sk_buff_head
*list_
)
1152 struct sk_buff
*next
= skb
->next
;
1154 if (next
== (struct sk_buff
*)list_
)
1160 * skb_peek_tail - peek at the tail of an &sk_buff_head
1161 * @list_: list to peek at
1163 * Peek an &sk_buff. Unlike most other operations you _MUST_
1164 * be careful with this one. A peek leaves the buffer on the
1165 * list and someone else may run off with it. You must hold
1166 * the appropriate locks or have a private queue to do this.
1168 * Returns %NULL for an empty list or a pointer to the tail element.
1169 * The reference count is not incremented and the reference is therefore
1170 * volatile. Use with caution.
1172 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1174 struct sk_buff
*skb
= list_
->prev
;
1176 if (skb
== (struct sk_buff
*)list_
)
1183 * skb_queue_len - get queue length
1184 * @list_: list to measure
1186 * Return the length of an &sk_buff queue.
1188 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1194 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1195 * @list: queue to initialize
1197 * This initializes only the list and queue length aspects of
1198 * an sk_buff_head object. This allows to initialize the list
1199 * aspects of an sk_buff_head without reinitializing things like
1200 * the spinlock. It can also be used for on-stack sk_buff_head
1201 * objects where the spinlock is known to not be used.
1203 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1205 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1210 * This function creates a split out lock class for each invocation;
1211 * this is needed for now since a whole lot of users of the skb-queue
1212 * infrastructure in drivers have different locking usage (in hardirq)
1213 * than the networking core (in softirq only). In the long run either the
1214 * network layer or drivers should need annotation to consolidate the
1215 * main types of usage into 3 classes.
1217 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1219 spin_lock_init(&list
->lock
);
1220 __skb_queue_head_init(list
);
1223 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1224 struct lock_class_key
*class)
1226 skb_queue_head_init(list
);
1227 lockdep_set_class(&list
->lock
, class);
1231 * Insert an sk_buff on a list.
1233 * The "__skb_xxxx()" functions are the non-atomic ones that
1234 * can only be called with interrupts disabled.
1236 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1237 struct sk_buff_head
*list
);
1238 static inline void __skb_insert(struct sk_buff
*newsk
,
1239 struct sk_buff
*prev
, struct sk_buff
*next
,
1240 struct sk_buff_head
*list
)
1244 next
->prev
= prev
->next
= newsk
;
1248 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1249 struct sk_buff
*prev
,
1250 struct sk_buff
*next
)
1252 struct sk_buff
*first
= list
->next
;
1253 struct sk_buff
*last
= list
->prev
;
1263 * skb_queue_splice - join two skb lists, this is designed for stacks
1264 * @list: the new list to add
1265 * @head: the place to add it in the first list
1267 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1268 struct sk_buff_head
*head
)
1270 if (!skb_queue_empty(list
)) {
1271 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1272 head
->qlen
+= list
->qlen
;
1277 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1278 * @list: the new list to add
1279 * @head: the place to add it in the first list
1281 * The list at @list is reinitialised
1283 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1284 struct sk_buff_head
*head
)
1286 if (!skb_queue_empty(list
)) {
1287 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1288 head
->qlen
+= list
->qlen
;
1289 __skb_queue_head_init(list
);
1294 * skb_queue_splice_tail - join two skb lists, each list being a queue
1295 * @list: the new list to add
1296 * @head: the place to add it in the first list
1298 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1299 struct sk_buff_head
*head
)
1301 if (!skb_queue_empty(list
)) {
1302 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1303 head
->qlen
+= list
->qlen
;
1308 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1309 * @list: the new list to add
1310 * @head: the place to add it in the first list
1312 * Each of the lists is a queue.
1313 * The list at @list is reinitialised
1315 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1316 struct sk_buff_head
*head
)
1318 if (!skb_queue_empty(list
)) {
1319 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1320 head
->qlen
+= list
->qlen
;
1321 __skb_queue_head_init(list
);
1326 * __skb_queue_after - queue a buffer at the list head
1327 * @list: list to use
1328 * @prev: place after this buffer
1329 * @newsk: buffer to queue
1331 * Queue a buffer int the middle of a list. This function takes no locks
1332 * and you must therefore hold required locks before calling it.
1334 * A buffer cannot be placed on two lists at the same time.
1336 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1337 struct sk_buff
*prev
,
1338 struct sk_buff
*newsk
)
1340 __skb_insert(newsk
, prev
, prev
->next
, list
);
1343 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1344 struct sk_buff_head
*list
);
1346 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1347 struct sk_buff
*next
,
1348 struct sk_buff
*newsk
)
1350 __skb_insert(newsk
, next
->prev
, next
, list
);
1354 * __skb_queue_head - queue a buffer at the list head
1355 * @list: list to use
1356 * @newsk: buffer to queue
1358 * Queue a buffer at the start of a list. This function takes no locks
1359 * and you must therefore hold required locks before calling it.
1361 * A buffer cannot be placed on two lists at the same time.
1363 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1364 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1365 struct sk_buff
*newsk
)
1367 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1371 * __skb_queue_tail - queue a buffer at the list tail
1372 * @list: list to use
1373 * @newsk: buffer to queue
1375 * Queue a buffer at the end of a list. This function takes no locks
1376 * and you must therefore hold required locks before calling it.
1378 * A buffer cannot be placed on two lists at the same time.
1380 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1381 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1382 struct sk_buff
*newsk
)
1384 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1388 * remove sk_buff from list. _Must_ be called atomically, and with
1391 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1392 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1394 struct sk_buff
*next
, *prev
;
1399 skb
->next
= skb
->prev
= NULL
;
1405 * __skb_dequeue - remove from the head of the queue
1406 * @list: list to dequeue from
1408 * Remove the head of the list. This function does not take any locks
1409 * so must be used with appropriate locks held only. The head item is
1410 * returned or %NULL if the list is empty.
1412 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1413 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1415 struct sk_buff
*skb
= skb_peek(list
);
1417 __skb_unlink(skb
, list
);
1422 * __skb_dequeue_tail - remove from the tail of the queue
1423 * @list: list to dequeue from
1425 * Remove the tail of the list. This function does not take any locks
1426 * so must be used with appropriate locks held only. The tail item is
1427 * returned or %NULL if the list is empty.
1429 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1430 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1432 struct sk_buff
*skb
= skb_peek_tail(list
);
1434 __skb_unlink(skb
, list
);
1439 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1441 return skb
->data_len
;
1444 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1446 return skb
->len
- skb
->data_len
;
1449 static inline int skb_pagelen(const struct sk_buff
*skb
)
1453 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1454 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1455 return len
+ skb_headlen(skb
);
1459 * __skb_fill_page_desc - initialise a paged fragment in an skb
1460 * @skb: buffer containing fragment to be initialised
1461 * @i: paged fragment index to initialise
1462 * @page: the page to use for this fragment
1463 * @off: the offset to the data with @page
1464 * @size: the length of the data
1466 * Initialises the @i'th fragment of @skb to point to &size bytes at
1467 * offset @off within @page.
1469 * Does not take any additional reference on the fragment.
1471 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1472 struct page
*page
, int off
, int size
)
1474 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1477 * Propagate page->pfmemalloc to the skb if we can. The problem is
1478 * that not all callers have unique ownership of the page. If
1479 * pfmemalloc is set, we check the mapping as a mapping implies
1480 * page->index is set (index and pfmemalloc share space).
1481 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1482 * do not lose pfmemalloc information as the pages would not be
1483 * allocated using __GFP_MEMALLOC.
1485 frag
->page
.p
= page
;
1486 frag
->page_offset
= off
;
1487 skb_frag_size_set(frag
, size
);
1489 page
= compound_head(page
);
1490 if (page
->pfmemalloc
&& !page
->mapping
)
1491 skb
->pfmemalloc
= true;
1495 * skb_fill_page_desc - initialise a paged fragment in an skb
1496 * @skb: buffer containing fragment to be initialised
1497 * @i: paged fragment index to initialise
1498 * @page: the page to use for this fragment
1499 * @off: the offset to the data with @page
1500 * @size: the length of the data
1502 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1503 * @skb to point to @size bytes at offset @off within @page. In
1504 * addition updates @skb such that @i is the last fragment.
1506 * Does not take any additional reference on the fragment.
1508 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1509 struct page
*page
, int off
, int size
)
1511 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1512 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1515 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1516 int size
, unsigned int truesize
);
1518 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1519 unsigned int truesize
);
1521 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1522 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1523 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1525 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1526 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1528 return skb
->head
+ skb
->tail
;
1531 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1533 skb
->tail
= skb
->data
- skb
->head
;
1536 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1538 skb_reset_tail_pointer(skb
);
1539 skb
->tail
+= offset
;
1542 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1543 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1548 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1550 skb
->tail
= skb
->data
;
1553 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1555 skb
->tail
= skb
->data
+ offset
;
1558 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1561 * Add data to an sk_buff
1563 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1564 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1565 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1567 unsigned char *tmp
= skb_tail_pointer(skb
);
1568 SKB_LINEAR_ASSERT(skb
);
1574 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1575 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1582 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1583 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1586 BUG_ON(skb
->len
< skb
->data_len
);
1587 return skb
->data
+= len
;
1590 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1592 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1595 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1597 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1599 if (len
> skb_headlen(skb
) &&
1600 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1603 return skb
->data
+= len
;
1606 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1608 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1611 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1613 if (likely(len
<= skb_headlen(skb
)))
1615 if (unlikely(len
> skb
->len
))
1617 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1621 * skb_headroom - bytes at buffer head
1622 * @skb: buffer to check
1624 * Return the number of bytes of free space at the head of an &sk_buff.
1626 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1628 return skb
->data
- skb
->head
;
1632 * skb_tailroom - bytes at buffer end
1633 * @skb: buffer to check
1635 * Return the number of bytes of free space at the tail of an sk_buff
1637 static inline int skb_tailroom(const struct sk_buff
*skb
)
1639 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1643 * skb_availroom - bytes at buffer end
1644 * @skb: buffer to check
1646 * Return the number of bytes of free space at the tail of an sk_buff
1647 * allocated by sk_stream_alloc()
1649 static inline int skb_availroom(const struct sk_buff
*skb
)
1651 if (skb_is_nonlinear(skb
))
1654 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1658 * skb_reserve - adjust headroom
1659 * @skb: buffer to alter
1660 * @len: bytes to move
1662 * Increase the headroom of an empty &sk_buff by reducing the tail
1663 * room. This is only allowed for an empty buffer.
1665 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1671 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1673 skb
->inner_mac_header
= skb
->mac_header
;
1674 skb
->inner_network_header
= skb
->network_header
;
1675 skb
->inner_transport_header
= skb
->transport_header
;
1678 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1680 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1683 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1686 return skb
->head
+ skb
->inner_transport_header
;
1689 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1691 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1694 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1697 skb_reset_inner_transport_header(skb
);
1698 skb
->inner_transport_header
+= offset
;
1701 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1703 return skb
->head
+ skb
->inner_network_header
;
1706 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1708 skb
->inner_network_header
= skb
->data
- skb
->head
;
1711 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1714 skb_reset_inner_network_header(skb
);
1715 skb
->inner_network_header
+= offset
;
1718 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
1720 return skb
->head
+ skb
->inner_mac_header
;
1723 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
1725 skb
->inner_mac_header
= skb
->data
- skb
->head
;
1728 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
1731 skb_reset_inner_mac_header(skb
);
1732 skb
->inner_mac_header
+= offset
;
1734 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1736 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
1739 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1741 return skb
->head
+ skb
->transport_header
;
1744 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1746 skb
->transport_header
= skb
->data
- skb
->head
;
1749 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1752 skb_reset_transport_header(skb
);
1753 skb
->transport_header
+= offset
;
1756 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1758 return skb
->head
+ skb
->network_header
;
1761 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1763 skb
->network_header
= skb
->data
- skb
->head
;
1766 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1768 skb_reset_network_header(skb
);
1769 skb
->network_header
+= offset
;
1772 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1774 return skb
->head
+ skb
->mac_header
;
1777 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1779 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
1782 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1784 skb
->mac_header
= skb
->data
- skb
->head
;
1787 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1789 skb_reset_mac_header(skb
);
1790 skb
->mac_header
+= offset
;
1793 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
1795 skb
->mac_header
= skb
->network_header
;
1798 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
1799 const int offset_hint
)
1801 struct flow_keys keys
;
1803 if (skb_transport_header_was_set(skb
))
1805 else if (skb_flow_dissect(skb
, &keys
))
1806 skb_set_transport_header(skb
, keys
.thoff
);
1808 skb_set_transport_header(skb
, offset_hint
);
1811 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1813 if (skb_mac_header_was_set(skb
)) {
1814 const unsigned char *old_mac
= skb_mac_header(skb
);
1816 skb_set_mac_header(skb
, -skb
->mac_len
);
1817 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1821 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1823 return skb
->csum_start
- skb_headroom(skb
);
1826 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1828 return skb_transport_header(skb
) - skb
->data
;
1831 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1833 return skb
->transport_header
- skb
->network_header
;
1836 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1838 return skb
->inner_transport_header
- skb
->inner_network_header
;
1841 static inline int skb_network_offset(const struct sk_buff
*skb
)
1843 return skb_network_header(skb
) - skb
->data
;
1846 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1848 return skb_inner_network_header(skb
) - skb
->data
;
1851 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1853 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1857 * CPUs often take a performance hit when accessing unaligned memory
1858 * locations. The actual performance hit varies, it can be small if the
1859 * hardware handles it or large if we have to take an exception and fix it
1862 * Since an ethernet header is 14 bytes network drivers often end up with
1863 * the IP header at an unaligned offset. The IP header can be aligned by
1864 * shifting the start of the packet by 2 bytes. Drivers should do this
1867 * skb_reserve(skb, NET_IP_ALIGN);
1869 * The downside to this alignment of the IP header is that the DMA is now
1870 * unaligned. On some architectures the cost of an unaligned DMA is high
1871 * and this cost outweighs the gains made by aligning the IP header.
1873 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1876 #ifndef NET_IP_ALIGN
1877 #define NET_IP_ALIGN 2
1881 * The networking layer reserves some headroom in skb data (via
1882 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1883 * the header has to grow. In the default case, if the header has to grow
1884 * 32 bytes or less we avoid the reallocation.
1886 * Unfortunately this headroom changes the DMA alignment of the resulting
1887 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1888 * on some architectures. An architecture can override this value,
1889 * perhaps setting it to a cacheline in size (since that will maintain
1890 * cacheline alignment of the DMA). It must be a power of 2.
1892 * Various parts of the networking layer expect at least 32 bytes of
1893 * headroom, you should not reduce this.
1895 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1896 * to reduce average number of cache lines per packet.
1897 * get_rps_cpus() for example only access one 64 bytes aligned block :
1898 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1901 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1904 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1906 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1908 if (unlikely(skb_is_nonlinear(skb
))) {
1913 skb_set_tail_pointer(skb
, len
);
1916 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1918 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1921 return ___pskb_trim(skb
, len
);
1922 __skb_trim(skb
, len
);
1926 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1928 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1932 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1933 * @skb: buffer to alter
1936 * This is identical to pskb_trim except that the caller knows that
1937 * the skb is not cloned so we should never get an error due to out-
1940 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1942 int err
= pskb_trim(skb
, len
);
1947 * skb_orphan - orphan a buffer
1948 * @skb: buffer to orphan
1950 * If a buffer currently has an owner then we call the owner's
1951 * destructor function and make the @skb unowned. The buffer continues
1952 * to exist but is no longer charged to its former owner.
1954 static inline void skb_orphan(struct sk_buff
*skb
)
1956 if (skb
->destructor
) {
1957 skb
->destructor(skb
);
1958 skb
->destructor
= NULL
;
1966 * skb_orphan_frags - orphan the frags contained in a buffer
1967 * @skb: buffer to orphan frags from
1968 * @gfp_mask: allocation mask for replacement pages
1970 * For each frag in the SKB which needs a destructor (i.e. has an
1971 * owner) create a copy of that frag and release the original
1972 * page by calling the destructor.
1974 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1976 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1978 return skb_copy_ubufs(skb
, gfp_mask
);
1982 * __skb_queue_purge - empty a list
1983 * @list: list to empty
1985 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1986 * the list and one reference dropped. This function does not take the
1987 * list lock and the caller must hold the relevant locks to use it.
1989 void skb_queue_purge(struct sk_buff_head
*list
);
1990 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1992 struct sk_buff
*skb
;
1993 while ((skb
= __skb_dequeue(list
)) != NULL
)
1997 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
1998 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
1999 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2001 void *netdev_alloc_frag(unsigned int fragsz
);
2003 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2007 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2008 * @dev: network device to receive on
2009 * @length: length to allocate
2011 * Allocate a new &sk_buff and assign it a usage count of one. The
2012 * buffer has unspecified headroom built in. Users should allocate
2013 * the headroom they think they need without accounting for the
2014 * built in space. The built in space is used for optimisations.
2016 * %NULL is returned if there is no free memory. Although this function
2017 * allocates memory it can be called from an interrupt.
2019 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2020 unsigned int length
)
2022 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2025 /* legacy helper around __netdev_alloc_skb() */
2026 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2029 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2032 /* legacy helper around netdev_alloc_skb() */
2033 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2035 return netdev_alloc_skb(NULL
, length
);
2039 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2040 unsigned int length
, gfp_t gfp
)
2042 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2044 if (NET_IP_ALIGN
&& skb
)
2045 skb_reserve(skb
, NET_IP_ALIGN
);
2049 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2050 unsigned int length
)
2052 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2056 * __skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data
2057 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2058 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2059 * @order: size of the allocation
2061 * Allocate a new page.
2063 * %NULL is returned if there is no free memory.
2065 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
2066 struct sk_buff
*skb
,
2071 gfp_mask
|= __GFP_COLD
;
2073 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2074 gfp_mask
|= __GFP_MEMALLOC
;
2076 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2077 if (skb
&& page
&& page
->pfmemalloc
)
2078 skb
->pfmemalloc
= true;
2084 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
2085 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2086 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2088 * Allocate a new page.
2090 * %NULL is returned if there is no free memory.
2092 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
2093 struct sk_buff
*skb
)
2095 return __skb_alloc_pages(gfp_mask
, skb
, 0);
2099 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2100 * @page: The page that was allocated from skb_alloc_page
2101 * @skb: The skb that may need pfmemalloc set
2103 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2104 struct sk_buff
*skb
)
2106 if (page
&& page
->pfmemalloc
)
2107 skb
->pfmemalloc
= true;
2111 * skb_frag_page - retrieve the page referred to by a paged fragment
2112 * @frag: the paged fragment
2114 * Returns the &struct page associated with @frag.
2116 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2118 return frag
->page
.p
;
2122 * __skb_frag_ref - take an addition reference on a paged fragment.
2123 * @frag: the paged fragment
2125 * Takes an additional reference on the paged fragment @frag.
2127 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2129 get_page(skb_frag_page(frag
));
2133 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2135 * @f: the fragment offset.
2137 * Takes an additional reference on the @f'th paged fragment of @skb.
2139 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2141 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2145 * __skb_frag_unref - release a reference on a paged fragment.
2146 * @frag: the paged fragment
2148 * Releases a reference on the paged fragment @frag.
2150 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2152 put_page(skb_frag_page(frag
));
2156 * skb_frag_unref - release a reference on a paged fragment of an skb.
2158 * @f: the fragment offset
2160 * Releases a reference on the @f'th paged fragment of @skb.
2162 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2164 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2168 * skb_frag_address - gets the address of the data contained in a paged fragment
2169 * @frag: the paged fragment buffer
2171 * Returns the address of the data within @frag. The page must already
2174 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2176 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2180 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2181 * @frag: the paged fragment buffer
2183 * Returns the address of the data within @frag. Checks that the page
2184 * is mapped and returns %NULL otherwise.
2186 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2188 void *ptr
= page_address(skb_frag_page(frag
));
2192 return ptr
+ frag
->page_offset
;
2196 * __skb_frag_set_page - sets the page contained in a paged fragment
2197 * @frag: the paged fragment
2198 * @page: the page to set
2200 * Sets the fragment @frag to contain @page.
2202 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2204 frag
->page
.p
= page
;
2208 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2210 * @f: the fragment offset
2211 * @page: the page to set
2213 * Sets the @f'th fragment of @skb to contain @page.
2215 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2218 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2221 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2224 * skb_frag_dma_map - maps a paged fragment via the DMA API
2225 * @dev: the device to map the fragment to
2226 * @frag: the paged fragment to map
2227 * @offset: the offset within the fragment (starting at the
2228 * fragment's own offset)
2229 * @size: the number of bytes to map
2230 * @dir: the direction of the mapping (%PCI_DMA_*)
2232 * Maps the page associated with @frag to @device.
2234 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2235 const skb_frag_t
*frag
,
2236 size_t offset
, size_t size
,
2237 enum dma_data_direction dir
)
2239 return dma_map_page(dev
, skb_frag_page(frag
),
2240 frag
->page_offset
+ offset
, size
, dir
);
2243 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2246 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2250 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2253 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2258 * skb_clone_writable - is the header of a clone writable
2259 * @skb: buffer to check
2260 * @len: length up to which to write
2262 * Returns true if modifying the header part of the cloned buffer
2263 * does not requires the data to be copied.
2265 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2267 return !skb_header_cloned(skb
) &&
2268 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2271 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2276 if (headroom
> skb_headroom(skb
))
2277 delta
= headroom
- skb_headroom(skb
);
2279 if (delta
|| cloned
)
2280 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2286 * skb_cow - copy header of skb when it is required
2287 * @skb: buffer to cow
2288 * @headroom: needed headroom
2290 * If the skb passed lacks sufficient headroom or its data part
2291 * is shared, data is reallocated. If reallocation fails, an error
2292 * is returned and original skb is not changed.
2294 * The result is skb with writable area skb->head...skb->tail
2295 * and at least @headroom of space at head.
2297 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2299 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2303 * skb_cow_head - skb_cow but only making the head writable
2304 * @skb: buffer to cow
2305 * @headroom: needed headroom
2307 * This function is identical to skb_cow except that we replace the
2308 * skb_cloned check by skb_header_cloned. It should be used when
2309 * you only need to push on some header and do not need to modify
2312 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2314 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2318 * skb_padto - pad an skbuff up to a minimal size
2319 * @skb: buffer to pad
2320 * @len: minimal length
2322 * Pads up a buffer to ensure the trailing bytes exist and are
2323 * blanked. If the buffer already contains sufficient data it
2324 * is untouched. Otherwise it is extended. Returns zero on
2325 * success. The skb is freed on error.
2328 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2330 unsigned int size
= skb
->len
;
2331 if (likely(size
>= len
))
2333 return skb_pad(skb
, len
- size
);
2336 static inline int skb_add_data(struct sk_buff
*skb
,
2337 char __user
*from
, int copy
)
2339 const int off
= skb
->len
;
2341 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2343 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2346 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2349 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2352 __skb_trim(skb
, off
);
2356 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2357 const struct page
*page
, int off
)
2360 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2362 return page
== skb_frag_page(frag
) &&
2363 off
== frag
->page_offset
+ skb_frag_size(frag
);
2368 static inline int __skb_linearize(struct sk_buff
*skb
)
2370 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2374 * skb_linearize - convert paged skb to linear one
2375 * @skb: buffer to linarize
2377 * If there is no free memory -ENOMEM is returned, otherwise zero
2378 * is returned and the old skb data released.
2380 static inline int skb_linearize(struct sk_buff
*skb
)
2382 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2386 * skb_has_shared_frag - can any frag be overwritten
2387 * @skb: buffer to test
2389 * Return true if the skb has at least one frag that might be modified
2390 * by an external entity (as in vmsplice()/sendfile())
2392 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2394 return skb_is_nonlinear(skb
) &&
2395 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2399 * skb_linearize_cow - make sure skb is linear and writable
2400 * @skb: buffer to process
2402 * If there is no free memory -ENOMEM is returned, otherwise zero
2403 * is returned and the old skb data released.
2405 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2407 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2408 __skb_linearize(skb
) : 0;
2412 * skb_postpull_rcsum - update checksum for received skb after pull
2413 * @skb: buffer to update
2414 * @start: start of data before pull
2415 * @len: length of data pulled
2417 * After doing a pull on a received packet, you need to call this to
2418 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2419 * CHECKSUM_NONE so that it can be recomputed from scratch.
2422 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2423 const void *start
, unsigned int len
)
2425 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2426 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2429 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2432 * pskb_trim_rcsum - trim received skb and update checksum
2433 * @skb: buffer to trim
2436 * This is exactly the same as pskb_trim except that it ensures the
2437 * checksum of received packets are still valid after the operation.
2440 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2442 if (likely(len
>= skb
->len
))
2444 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2445 skb
->ip_summed
= CHECKSUM_NONE
;
2446 return __pskb_trim(skb
, len
);
2449 #define skb_queue_walk(queue, skb) \
2450 for (skb = (queue)->next; \
2451 skb != (struct sk_buff *)(queue); \
2454 #define skb_queue_walk_safe(queue, skb, tmp) \
2455 for (skb = (queue)->next, tmp = skb->next; \
2456 skb != (struct sk_buff *)(queue); \
2457 skb = tmp, tmp = skb->next)
2459 #define skb_queue_walk_from(queue, skb) \
2460 for (; skb != (struct sk_buff *)(queue); \
2463 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2464 for (tmp = skb->next; \
2465 skb != (struct sk_buff *)(queue); \
2466 skb = tmp, tmp = skb->next)
2468 #define skb_queue_reverse_walk(queue, skb) \
2469 for (skb = (queue)->prev; \
2470 skb != (struct sk_buff *)(queue); \
2473 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2474 for (skb = (queue)->prev, tmp = skb->prev; \
2475 skb != (struct sk_buff *)(queue); \
2476 skb = tmp, tmp = skb->prev)
2478 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2479 for (tmp = skb->prev; \
2480 skb != (struct sk_buff *)(queue); \
2481 skb = tmp, tmp = skb->prev)
2483 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2485 return skb_shinfo(skb
)->frag_list
!= NULL
;
2488 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2490 skb_shinfo(skb
)->frag_list
= NULL
;
2493 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2495 frag
->next
= skb_shinfo(skb
)->frag_list
;
2496 skb_shinfo(skb
)->frag_list
= frag
;
2499 #define skb_walk_frags(skb, iter) \
2500 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2502 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2503 int *peeked
, int *off
, int *err
);
2504 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
2506 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2507 struct poll_table_struct
*wait
);
2508 int skb_copy_datagram_iovec(const struct sk_buff
*from
, int offset
,
2509 struct iovec
*to
, int size
);
2510 int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
, int hlen
,
2512 int skb_copy_datagram_from_iovec(struct sk_buff
*skb
, int offset
,
2513 const struct iovec
*from
, int from_offset
,
2515 int zerocopy_sg_from_iovec(struct sk_buff
*skb
, const struct iovec
*frm
,
2516 int offset
, size_t count
);
2517 int skb_copy_datagram_const_iovec(const struct sk_buff
*from
, int offset
,
2518 const struct iovec
*to
, int to_offset
,
2520 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2521 void skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
);
2522 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
2523 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
2524 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
2525 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
2526 int len
, __wsum csum
);
2527 int skb_splice_bits(struct sk_buff
*skb
, unsigned int offset
,
2528 struct pipe_inode_info
*pipe
, unsigned int len
,
2529 unsigned int flags
);
2530 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2531 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
2532 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
2534 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
2535 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
2536 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
2537 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
2538 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
2540 struct skb_checksum_ops
{
2541 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
2542 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
2545 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2546 __wsum csum
, const struct skb_checksum_ops
*ops
);
2547 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2550 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2551 int len
, void *buffer
)
2553 int hlen
= skb_headlen(skb
);
2555 if (hlen
- offset
>= len
)
2556 return skb
->data
+ offset
;
2558 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2565 * skb_needs_linearize - check if we need to linearize a given skb
2566 * depending on the given device features.
2567 * @skb: socket buffer to check
2568 * @features: net device features
2570 * Returns true if either:
2571 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2572 * 2. skb is fragmented and the device does not support SG.
2574 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
2575 netdev_features_t features
)
2577 return skb_is_nonlinear(skb
) &&
2578 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
2579 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
2582 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2584 const unsigned int len
)
2586 memcpy(to
, skb
->data
, len
);
2589 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2590 const int offset
, void *to
,
2591 const unsigned int len
)
2593 memcpy(to
, skb
->data
+ offset
, len
);
2596 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2598 const unsigned int len
)
2600 memcpy(skb
->data
, from
, len
);
2603 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2606 const unsigned int len
)
2608 memcpy(skb
->data
+ offset
, from
, len
);
2611 void skb_init(void);
2613 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2619 * skb_get_timestamp - get timestamp from a skb
2620 * @skb: skb to get stamp from
2621 * @stamp: pointer to struct timeval to store stamp in
2623 * Timestamps are stored in the skb as offsets to a base timestamp.
2624 * This function converts the offset back to a struct timeval and stores
2627 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2628 struct timeval
*stamp
)
2630 *stamp
= ktime_to_timeval(skb
->tstamp
);
2633 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2634 struct timespec
*stamp
)
2636 *stamp
= ktime_to_timespec(skb
->tstamp
);
2639 static inline void __net_timestamp(struct sk_buff
*skb
)
2641 skb
->tstamp
= ktime_get_real();
2644 static inline ktime_t
net_timedelta(ktime_t t
)
2646 return ktime_sub(ktime_get_real(), t
);
2649 static inline ktime_t
net_invalid_timestamp(void)
2651 return ktime_set(0, 0);
2654 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2656 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2657 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2659 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2661 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2665 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2670 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2673 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2675 * PHY drivers may accept clones of transmitted packets for
2676 * timestamping via their phy_driver.txtstamp method. These drivers
2677 * must call this function to return the skb back to the stack, with
2678 * or without a timestamp.
2680 * @skb: clone of the the original outgoing packet
2681 * @hwtstamps: hardware time stamps, may be NULL if not available
2684 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2685 struct skb_shared_hwtstamps
*hwtstamps
);
2688 * skb_tstamp_tx - queue clone of skb with send time stamps
2689 * @orig_skb: the original outgoing packet
2690 * @hwtstamps: hardware time stamps, may be NULL if not available
2692 * If the skb has a socket associated, then this function clones the
2693 * skb (thus sharing the actual data and optional structures), stores
2694 * the optional hardware time stamping information (if non NULL) or
2695 * generates a software time stamp (otherwise), then queues the clone
2696 * to the error queue of the socket. Errors are silently ignored.
2698 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2699 struct skb_shared_hwtstamps
*hwtstamps
);
2701 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2703 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2704 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2705 skb_tstamp_tx(skb
, NULL
);
2709 * skb_tx_timestamp() - Driver hook for transmit timestamping
2711 * Ethernet MAC Drivers should call this function in their hard_xmit()
2712 * function immediately before giving the sk_buff to the MAC hardware.
2714 * Specifically, one should make absolutely sure that this function is
2715 * called before TX completion of this packet can trigger. Otherwise
2716 * the packet could potentially already be freed.
2718 * @skb: A socket buffer.
2720 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2722 skb_clone_tx_timestamp(skb
);
2723 sw_tx_timestamp(skb
);
2727 * skb_complete_wifi_ack - deliver skb with wifi status
2729 * @skb: the original outgoing packet
2730 * @acked: ack status
2733 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2735 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2736 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2738 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2740 return ((skb
->ip_summed
& CHECKSUM_UNNECESSARY
) || skb
->csum_valid
);
2744 * skb_checksum_complete - Calculate checksum of an entire packet
2745 * @skb: packet to process
2747 * This function calculates the checksum over the entire packet plus
2748 * the value of skb->csum. The latter can be used to supply the
2749 * checksum of a pseudo header as used by TCP/UDP. It returns the
2752 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2753 * this function can be used to verify that checksum on received
2754 * packets. In that case the function should return zero if the
2755 * checksum is correct. In particular, this function will return zero
2756 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2757 * hardware has already verified the correctness of the checksum.
2759 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2761 return skb_csum_unnecessary(skb
) ?
2762 0 : __skb_checksum_complete(skb
);
2765 /* Check if we need to perform checksum complete validation.
2767 * Returns true if checksum complete is needed, false otherwise
2768 * (either checksum is unnecessary or zero checksum is allowed).
2770 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
2774 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
2775 skb
->csum_valid
= 1;
2782 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
2785 #define CHECKSUM_BREAK 76
2787 /* Validate (init) checksum based on checksum complete.
2790 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
2791 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
2792 * checksum is stored in skb->csum for use in __skb_checksum_complete
2793 * non-zero: value of invalid checksum
2796 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
2800 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
2801 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
2802 skb
->csum_valid
= 1;
2809 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
2812 csum
= __skb_checksum_complete(skb
);
2813 skb
->csum_valid
= !csum
;
2820 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
2825 /* Perform checksum validate (init). Note that this is a macro since we only
2826 * want to calculate the pseudo header which is an input function if necessary.
2827 * First we try to validate without any computation (checksum unnecessary) and
2828 * then calculate based on checksum complete calling the function to compute
2832 * 0: checksum is validated or try to in skb_checksum_complete
2833 * non-zero: value of invalid checksum
2835 #define __skb_checksum_validate(skb, proto, complete, \
2836 zero_okay, check, compute_pseudo) \
2838 __sum16 __ret = 0; \
2839 skb->csum_valid = 0; \
2840 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
2841 __ret = __skb_checksum_validate_complete(skb, \
2842 complete, compute_pseudo(skb, proto)); \
2846 #define skb_checksum_init(skb, proto, compute_pseudo) \
2847 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
2849 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
2850 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
2852 #define skb_checksum_validate(skb, proto, compute_pseudo) \
2853 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
2855 #define skb_checksum_validate_zero_check(skb, proto, check, \
2857 __skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo)
2859 #define skb_checksum_simple_validate(skb) \
2860 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
2862 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2863 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2864 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2866 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2867 nf_conntrack_destroy(nfct
);
2869 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2872 atomic_inc(&nfct
->use
);
2875 #ifdef CONFIG_BRIDGE_NETFILTER
2876 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2878 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2881 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2884 atomic_inc(&nf_bridge
->use
);
2886 #endif /* CONFIG_BRIDGE_NETFILTER */
2887 static inline void nf_reset(struct sk_buff
*skb
)
2889 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2890 nf_conntrack_put(skb
->nfct
);
2893 #ifdef CONFIG_BRIDGE_NETFILTER
2894 nf_bridge_put(skb
->nf_bridge
);
2895 skb
->nf_bridge
= NULL
;
2899 static inline void nf_reset_trace(struct sk_buff
*skb
)
2901 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
2906 /* Note: This doesn't put any conntrack and bridge info in dst. */
2907 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2909 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2910 dst
->nfct
= src
->nfct
;
2911 nf_conntrack_get(src
->nfct
);
2912 dst
->nfctinfo
= src
->nfctinfo
;
2914 #ifdef CONFIG_BRIDGE_NETFILTER
2915 dst
->nf_bridge
= src
->nf_bridge
;
2916 nf_bridge_get(src
->nf_bridge
);
2918 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
2919 dst
->nf_trace
= src
->nf_trace
;
2923 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2925 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2926 nf_conntrack_put(dst
->nfct
);
2928 #ifdef CONFIG_BRIDGE_NETFILTER
2929 nf_bridge_put(dst
->nf_bridge
);
2931 __nf_copy(dst
, src
);
2934 #ifdef CONFIG_NETWORK_SECMARK
2935 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2937 to
->secmark
= from
->secmark
;
2940 static inline void skb_init_secmark(struct sk_buff
*skb
)
2945 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2948 static inline void skb_init_secmark(struct sk_buff
*skb
)
2952 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
2954 return !skb
->destructor
&&
2955 #if IS_ENABLED(CONFIG_XFRM)
2958 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
2961 !skb
->_skb_refdst
&&
2962 !skb_has_frag_list(skb
);
2965 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2967 skb
->queue_mapping
= queue_mapping
;
2970 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
2972 return skb
->queue_mapping
;
2975 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
2977 to
->queue_mapping
= from
->queue_mapping
;
2980 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
2982 skb
->queue_mapping
= rx_queue
+ 1;
2985 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
2987 return skb
->queue_mapping
- 1;
2990 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
2992 return skb
->queue_mapping
!= 0;
2995 u16
__skb_tx_hash(const struct net_device
*dev
, const struct sk_buff
*skb
,
2996 unsigned int num_tx_queues
);
2998 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3007 /* Keeps track of mac header offset relative to skb->head.
3008 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3009 * For non-tunnel skb it points to skb_mac_header() and for
3010 * tunnel skb it points to outer mac header.
3011 * Keeps track of level of encapsulation of network headers.
3018 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3020 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3022 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3023 SKB_GSO_CB(inner_skb
)->mac_offset
;
3026 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3028 int new_headroom
, headroom
;
3031 headroom
= skb_headroom(skb
);
3032 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3036 new_headroom
= skb_headroom(skb
);
3037 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3041 /* Compute the checksum for a gso segment. First compute the checksum value
3042 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3043 * then add in skb->csum (checksum from csum_start to end of packet).
3044 * skb->csum and csum_start are then updated to reflect the checksum of the
3045 * resultant packet starting from the transport header-- the resultant checksum
3046 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3049 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3051 int plen
= SKB_GSO_CB(skb
)->csum_start
- skb_headroom(skb
) -
3052 skb_transport_offset(skb
);
3055 csum
= csum_fold(csum_partial(skb_transport_header(skb
),
3058 SKB_GSO_CB(skb
)->csum_start
-= plen
;
3063 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3065 return skb_shinfo(skb
)->gso_size
;
3068 /* Note: Should be called only if skb_is_gso(skb) is true */
3069 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3071 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3074 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3076 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3078 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3079 * wanted then gso_type will be set. */
3080 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3082 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3083 unlikely(shinfo
->gso_type
== 0)) {
3084 __skb_warn_lro_forwarding(skb
);
3090 static inline void skb_forward_csum(struct sk_buff
*skb
)
3092 /* Unfortunately we don't support this one. Any brave souls? */
3093 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3094 skb
->ip_summed
= CHECKSUM_NONE
;
3098 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3099 * @skb: skb to check
3101 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3102 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3103 * use this helper, to document places where we make this assertion.
3105 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3108 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3112 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3114 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3116 u32
__skb_get_poff(const struct sk_buff
*skb
);
3119 * skb_head_is_locked - Determine if the skb->head is locked down
3120 * @skb: skb to check
3122 * The head on skbs build around a head frag can be removed if they are
3123 * not cloned. This function returns true if the skb head is locked down
3124 * due to either being allocated via kmalloc, or by being a clone with
3125 * multiple references to the head.
3127 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3129 return !skb
->head_frag
|| skb_cloned(skb
);
3133 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3137 * skb_gso_network_seglen is used to determine the real size of the
3138 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3140 * The MAC/L2 header is not accounted for.
3142 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3144 unsigned int hdr_len
= skb_transport_header(skb
) -
3145 skb_network_header(skb
);
3146 return hdr_len
+ skb_gso_transport_seglen(skb
);
3148 #endif /* __KERNEL__ */
3149 #endif /* _LINUX_SKBUFF_H */