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) ALIGN(X, SMP_CACHE_BYTES)
116 #define SKB_WITH_OVERHEAD(X) \
117 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
118 #define SKB_MAX_ORDER(X, ORDER) \
119 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
120 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
121 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
123 /* return minimum truesize of one skb containing X bytes of data */
124 #define SKB_TRUESIZE(X) ((X) + \
125 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
126 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
130 struct pipe_inode_info
;
132 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
133 struct nf_conntrack
{
138 #ifdef CONFIG_BRIDGE_NETFILTER
139 struct nf_bridge_info
{
142 struct net_device
*physindev
;
143 struct net_device
*physoutdev
;
144 unsigned long data
[32 / sizeof(unsigned long)];
148 struct sk_buff_head
{
149 /* These two members must be first. */
150 struct sk_buff
*next
;
151 struct sk_buff
*prev
;
159 /* To allow 64K frame to be packed as single skb without frag_list we
160 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
161 * buffers which do not start on a page boundary.
163 * Since GRO uses frags we allocate at least 16 regardless of page
166 #if (65536/PAGE_SIZE + 1) < 16
167 #define MAX_SKB_FRAGS 16UL
169 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
172 typedef struct skb_frag_struct skb_frag_t
;
174 struct skb_frag_struct
{
178 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
187 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
192 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
197 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
202 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
207 #define HAVE_HW_TIME_STAMP
210 * struct skb_shared_hwtstamps - hardware time stamps
211 * @hwtstamp: hardware time stamp transformed into duration
212 * since arbitrary point in time
214 * Software time stamps generated by ktime_get_real() are stored in
217 * hwtstamps can only be compared against other hwtstamps from
220 * This structure is attached to packets as part of the
221 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
223 struct skb_shared_hwtstamps
{
227 /* Definitions for tx_flags in struct skb_shared_info */
229 /* generate hardware time stamp */
230 SKBTX_HW_TSTAMP
= 1 << 0,
232 /* generate software time stamp when queueing packet to NIC */
233 SKBTX_SW_TSTAMP
= 1 << 1,
235 /* device driver is going to provide hardware time stamp */
236 SKBTX_IN_PROGRESS
= 1 << 2,
238 /* device driver supports TX zero-copy buffers */
239 SKBTX_DEV_ZEROCOPY
= 1 << 3,
241 /* generate wifi status information (where possible) */
242 SKBTX_WIFI_STATUS
= 1 << 4,
244 /* This indicates at least one fragment might be overwritten
245 * (as in vmsplice(), sendfile() ...)
246 * If we need to compute a TX checksum, we'll need to copy
247 * all frags to avoid possible bad checksum
249 SKBTX_SHARED_FRAG
= 1 << 5,
251 /* generate software time stamp when entering packet scheduling */
252 SKBTX_SCHED_TSTAMP
= 1 << 6,
254 /* generate software timestamp on peer data acknowledgment */
255 SKBTX_ACK_TSTAMP
= 1 << 7,
258 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
259 SKBTX_SCHED_TSTAMP | \
261 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
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
;
293 * Warning : all fields before dataref are cleared in __alloc_skb()
297 /* Intermediate layers must ensure that destructor_arg
298 * remains valid until skb destructor */
299 void * destructor_arg
;
301 /* must be last field, see pskb_expand_head() */
302 skb_frag_t frags
[MAX_SKB_FRAGS
];
305 /* We divide dataref into two halves. The higher 16 bits hold references
306 * to the payload part of skb->data. The lower 16 bits hold references to
307 * the entire skb->data. A clone of a headerless skb holds the length of
308 * the header in skb->hdr_len.
310 * All users must obey the rule that the skb->data reference count must be
311 * greater than or equal to the payload reference count.
313 * Holding a reference to the payload part means that the user does not
314 * care about modifications to the header part of skb->data.
316 #define SKB_DATAREF_SHIFT 16
317 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
321 SKB_FCLONE_UNAVAILABLE
,
327 SKB_GSO_TCPV4
= 1 << 0,
328 SKB_GSO_UDP
= 1 << 1,
330 /* This indicates the skb is from an untrusted source. */
331 SKB_GSO_DODGY
= 1 << 2,
333 /* This indicates the tcp segment has CWR set. */
334 SKB_GSO_TCP_ECN
= 1 << 3,
336 SKB_GSO_TCPV6
= 1 << 4,
338 SKB_GSO_FCOE
= 1 << 5,
340 SKB_GSO_GRE
= 1 << 6,
342 SKB_GSO_GRE_CSUM
= 1 << 7,
344 SKB_GSO_IPIP
= 1 << 8,
346 SKB_GSO_SIT
= 1 << 9,
348 SKB_GSO_UDP_TUNNEL
= 1 << 10,
350 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
352 SKB_GSO_MPLS
= 1 << 12,
356 #if BITS_PER_LONG > 32
357 #define NET_SKBUFF_DATA_USES_OFFSET 1
360 #ifdef NET_SKBUFF_DATA_USES_OFFSET
361 typedef unsigned int sk_buff_data_t
;
363 typedef unsigned char *sk_buff_data_t
;
367 * struct skb_mstamp - multi resolution time stamps
368 * @stamp_us: timestamp in us resolution
369 * @stamp_jiffies: timestamp in jiffies
382 * skb_mstamp_get - get current timestamp
383 * @cl: place to store timestamps
385 static inline void skb_mstamp_get(struct skb_mstamp
*cl
)
387 u64 val
= local_clock();
389 do_div(val
, NSEC_PER_USEC
);
390 cl
->stamp_us
= (u32
)val
;
391 cl
->stamp_jiffies
= (u32
)jiffies
;
395 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
396 * @t1: pointer to newest sample
397 * @t0: pointer to oldest sample
399 static inline u32
skb_mstamp_us_delta(const struct skb_mstamp
*t1
,
400 const struct skb_mstamp
*t0
)
402 s32 delta_us
= t1
->stamp_us
- t0
->stamp_us
;
403 u32 delta_jiffies
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
405 /* If delta_us is negative, this might be because interval is too big,
406 * or local_clock() drift is too big : fallback using jiffies.
409 delta_jiffies
>= (INT_MAX
/ (USEC_PER_SEC
/ HZ
)))
411 delta_us
= jiffies_to_usecs(delta_jiffies
);
418 * struct sk_buff - socket buffer
419 * @next: Next buffer in list
420 * @prev: Previous buffer in list
421 * @tstamp: Time we arrived/left
422 * @sk: Socket we are owned by
423 * @dev: Device we arrived on/are leaving by
424 * @cb: Control buffer. Free for use by every layer. Put private vars here
425 * @_skb_refdst: destination entry (with norefcount bit)
426 * @sp: the security path, used for xfrm
427 * @len: Length of actual data
428 * @data_len: Data length
429 * @mac_len: Length of link layer header
430 * @hdr_len: writable header length of cloned skb
431 * @csum: Checksum (must include start/offset pair)
432 * @csum_start: Offset from skb->head where checksumming should start
433 * @csum_offset: Offset from csum_start where checksum should be stored
434 * @priority: Packet queueing priority
435 * @ignore_df: allow local fragmentation
436 * @cloned: Head may be cloned (check refcnt to be sure)
437 * @ip_summed: Driver fed us an IP checksum
438 * @nohdr: Payload reference only, must not modify header
439 * @nfctinfo: Relationship of this skb to the connection
440 * @pkt_type: Packet class
441 * @fclone: skbuff clone status
442 * @ipvs_property: skbuff is owned by ipvs
443 * @peeked: this packet has been seen already, so stats have been
444 * done for it, don't do them again
445 * @nf_trace: netfilter packet trace flag
446 * @protocol: Packet protocol from driver
447 * @destructor: Destruct function
448 * @nfct: Associated connection, if any
449 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
450 * @skb_iif: ifindex of device we arrived on
451 * @tc_index: Traffic control index
452 * @tc_verd: traffic control verdict
453 * @hash: the packet hash
454 * @queue_mapping: Queue mapping for multiqueue devices
455 * @xmit_more: More SKBs are pending for this queue
456 * @ndisc_nodetype: router type (from link layer)
457 * @ooo_okay: allow the mapping of a socket to a queue to be changed
458 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
460 * @sw_hash: indicates hash was computed in software stack
461 * @wifi_acked_valid: wifi_acked was set
462 * @wifi_acked: whether frame was acked on wifi or not
463 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
464 * @dma_cookie: a cookie to one of several possible DMA operations
465 * done by skb DMA functions
466 * @napi_id: id of the NAPI struct this skb came from
467 * @secmark: security marking
468 * @mark: Generic packet mark
469 * @dropcount: total number of sk_receive_queue overflows
470 * @vlan_proto: vlan encapsulation protocol
471 * @vlan_tci: vlan tag control information
472 * @inner_protocol: Protocol (encapsulation)
473 * @inner_transport_header: Inner transport layer header (encapsulation)
474 * @inner_network_header: Network layer header (encapsulation)
475 * @inner_mac_header: Link layer header (encapsulation)
476 * @transport_header: Transport layer header
477 * @network_header: Network layer header
478 * @mac_header: Link layer header
479 * @tail: Tail pointer
481 * @head: Head of buffer
482 * @data: Data head pointer
483 * @truesize: Buffer size
484 * @users: User count - see {datagram,tcp}.c
488 /* These two members must be first. */
489 struct sk_buff
*next
;
490 struct sk_buff
*prev
;
494 struct skb_mstamp skb_mstamp
;
498 struct net_device
*dev
;
501 * This is the control buffer. It is free to use for every
502 * layer. Please put your private variables there. If you
503 * want to keep them across layers you have to do a skb_clone()
504 * first. This is owned by whoever has the skb queued ATM.
506 char cb
[48] __aligned(8);
508 unsigned long _skb_refdst
;
524 kmemcheck_bitfield_begin(flags1
);
535 kmemcheck_bitfield_end(flags1
);
538 void (*destructor
)(struct sk_buff
*skb
);
539 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
540 struct nf_conntrack
*nfct
;
542 #ifdef CONFIG_BRIDGE_NETFILTER
543 struct nf_bridge_info
*nf_bridge
;
553 #ifdef CONFIG_NET_SCHED
554 __u16 tc_index
; /* traffic control index */
555 #ifdef CONFIG_NET_CLS_ACT
556 __u16 tc_verd
; /* traffic control verdict */
561 kmemcheck_bitfield_begin(flags2
);
563 #ifdef CONFIG_IPV6_NDISC_NODETYPE
564 __u8 ndisc_nodetype
:2;
570 __u8 wifi_acked_valid
:1;
574 /* Encapsulation protocol and NIC drivers should use
575 * this flag to indicate to each other if the skb contains
576 * encapsulated packet or not and maybe use the inner packet
579 __u8 encapsulation
:1;
580 __u8 encap_hdr_csum
:1;
582 __u8 csum_complete_sw
:1;
583 /* 1/3 bit hole (depending on ndisc_nodetype presence) */
584 kmemcheck_bitfield_end(flags2
);
586 #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL
588 unsigned int napi_id
;
589 dma_cookie_t dma_cookie
;
592 #ifdef CONFIG_NETWORK_SECMARK
598 __u32 reserved_tailroom
;
601 __be16 inner_protocol
;
602 __u16 inner_transport_header
;
603 __u16 inner_network_header
;
604 __u16 inner_mac_header
;
605 __u16 transport_header
;
606 __u16 network_header
;
608 /* These elements must be at the end, see alloc_skb() for details. */
613 unsigned int truesize
;
619 * Handling routines are only of interest to the kernel
621 #include <linux/slab.h>
624 #define SKB_ALLOC_FCLONE 0x01
625 #define SKB_ALLOC_RX 0x02
627 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
628 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
630 return unlikely(skb
->pfmemalloc
);
634 * skb might have a dst pointer attached, refcounted or not.
635 * _skb_refdst low order bit is set if refcount was _not_ taken
637 #define SKB_DST_NOREF 1UL
638 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
641 * skb_dst - returns skb dst_entry
644 * Returns skb dst_entry, regardless of reference taken or not.
646 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
648 /* If refdst was not refcounted, check we still are in a
649 * rcu_read_lock section
651 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
652 !rcu_read_lock_held() &&
653 !rcu_read_lock_bh_held());
654 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
658 * skb_dst_set - sets skb dst
662 * Sets skb dst, assuming a reference was taken on dst and should
663 * be released by skb_dst_drop()
665 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
667 skb
->_skb_refdst
= (unsigned long)dst
;
670 void __skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
,
674 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
678 * Sets skb dst, assuming a reference was not taken on dst.
679 * If dst entry is cached, we do not take reference and dst_release
680 * will be avoided by refdst_drop. If dst entry is not cached, we take
681 * reference, so that last dst_release can destroy the dst immediately.
683 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
685 __skb_dst_set_noref(skb
, dst
, false);
689 * skb_dst_set_noref_force - sets skb dst, without taking reference
693 * Sets skb dst, assuming a reference was not taken on dst.
694 * No reference is taken and no dst_release will be called. While for
695 * cached dsts deferred reclaim is a basic feature, for entries that are
696 * not cached it is caller's job to guarantee that last dst_release for
697 * provided dst happens when nobody uses it, eg. after a RCU grace period.
699 static inline void skb_dst_set_noref_force(struct sk_buff
*skb
,
700 struct dst_entry
*dst
)
702 __skb_dst_set_noref(skb
, dst
, true);
706 * skb_dst_is_noref - Test if skb dst isn't refcounted
709 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
711 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
714 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
716 return (struct rtable
*)skb_dst(skb
);
719 void kfree_skb(struct sk_buff
*skb
);
720 void kfree_skb_list(struct sk_buff
*segs
);
721 void skb_tx_error(struct sk_buff
*skb
);
722 void consume_skb(struct sk_buff
*skb
);
723 void __kfree_skb(struct sk_buff
*skb
);
724 extern struct kmem_cache
*skbuff_head_cache
;
726 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
727 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
728 bool *fragstolen
, int *delta_truesize
);
730 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
732 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
733 static inline struct sk_buff
*alloc_skb(unsigned int size
,
736 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
739 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
742 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
745 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
746 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
748 return __alloc_skb_head(priority
, -1);
751 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
752 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
753 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
754 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
755 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
756 gfp_t gfp_mask
, bool fclone
);
757 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
760 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
763 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
764 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
765 unsigned int headroom
);
766 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
767 int newtailroom
, gfp_t priority
);
768 int skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
769 int offset
, int len
);
770 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
,
772 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
773 int skb_pad(struct sk_buff
*skb
, int pad
);
774 #define dev_kfree_skb(a) consume_skb(a)
776 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
777 int getfrag(void *from
, char *to
, int offset
,
778 int len
, int odd
, struct sk_buff
*skb
),
779 void *from
, int length
);
781 struct skb_seq_state
{
785 __u32 stepped_offset
;
786 struct sk_buff
*root_skb
;
787 struct sk_buff
*cur_skb
;
791 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
792 unsigned int to
, struct skb_seq_state
*st
);
793 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
794 struct skb_seq_state
*st
);
795 void skb_abort_seq_read(struct skb_seq_state
*st
);
797 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
798 unsigned int to
, struct ts_config
*config
,
799 struct ts_state
*state
);
802 * Packet hash types specify the type of hash in skb_set_hash.
804 * Hash types refer to the protocol layer addresses which are used to
805 * construct a packet's hash. The hashes are used to differentiate or identify
806 * flows of the protocol layer for the hash type. Hash types are either
807 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
809 * Properties of hashes:
811 * 1) Two packets in different flows have different hash values
812 * 2) Two packets in the same flow should have the same hash value
814 * A hash at a higher layer is considered to be more specific. A driver should
815 * set the most specific hash possible.
817 * A driver cannot indicate a more specific hash than the layer at which a hash
818 * was computed. For instance an L3 hash cannot be set as an L4 hash.
820 * A driver may indicate a hash level which is less specific than the
821 * actual layer the hash was computed on. For instance, a hash computed
822 * at L4 may be considered an L3 hash. This should only be done if the
823 * driver can't unambiguously determine that the HW computed the hash at
824 * the higher layer. Note that the "should" in the second property above
827 enum pkt_hash_types
{
828 PKT_HASH_TYPE_NONE
, /* Undefined type */
829 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
830 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
831 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
835 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
837 skb
->l4_hash
= (type
== PKT_HASH_TYPE_L4
);
842 void __skb_get_hash(struct sk_buff
*skb
);
843 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
845 if (!skb
->l4_hash
&& !skb
->sw_hash
)
851 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
856 static inline void skb_clear_hash(struct sk_buff
*skb
)
863 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
869 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
871 to
->hash
= from
->hash
;
872 to
->sw_hash
= from
->sw_hash
;
873 to
->l4_hash
= from
->l4_hash
;
876 #ifdef NET_SKBUFF_DATA_USES_OFFSET
877 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
879 return skb
->head
+ skb
->end
;
882 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
887 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
892 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
894 return skb
->end
- skb
->head
;
899 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
901 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
903 return &skb_shinfo(skb
)->hwtstamps
;
907 * skb_queue_empty - check if a queue is empty
910 * Returns true if the queue is empty, false otherwise.
912 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
914 return list
->next
== (const struct sk_buff
*) list
;
918 * skb_queue_is_last - check if skb is the last entry in the queue
922 * Returns true if @skb is the last buffer on the list.
924 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
925 const struct sk_buff
*skb
)
927 return skb
->next
== (const struct sk_buff
*) list
;
931 * skb_queue_is_first - check if skb is the first entry in the queue
935 * Returns true if @skb is the first buffer on the list.
937 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
938 const struct sk_buff
*skb
)
940 return skb
->prev
== (const struct sk_buff
*) list
;
944 * skb_queue_next - return the next packet in the queue
946 * @skb: current buffer
948 * Return the next packet in @list after @skb. It is only valid to
949 * call this if skb_queue_is_last() evaluates to false.
951 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
952 const struct sk_buff
*skb
)
954 /* This BUG_ON may seem severe, but if we just return then we
955 * are going to dereference garbage.
957 BUG_ON(skb_queue_is_last(list
, skb
));
962 * skb_queue_prev - return the prev packet in the queue
964 * @skb: current buffer
966 * Return the prev packet in @list before @skb. It is only valid to
967 * call this if skb_queue_is_first() evaluates to false.
969 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
970 const struct sk_buff
*skb
)
972 /* This BUG_ON may seem severe, but if we just return then we
973 * are going to dereference garbage.
975 BUG_ON(skb_queue_is_first(list
, skb
));
980 * skb_get - reference buffer
981 * @skb: buffer to reference
983 * Makes another reference to a socket buffer and returns a pointer
986 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
988 atomic_inc(&skb
->users
);
993 * If users == 1, we are the only owner and are can avoid redundant
998 * skb_cloned - is the buffer a clone
999 * @skb: buffer to check
1001 * Returns true if the buffer was generated with skb_clone() and is
1002 * one of multiple shared copies of the buffer. Cloned buffers are
1003 * shared data so must not be written to under normal circumstances.
1005 static inline int skb_cloned(const struct sk_buff
*skb
)
1007 return skb
->cloned
&&
1008 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1011 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1013 might_sleep_if(pri
& __GFP_WAIT
);
1015 if (skb_cloned(skb
))
1016 return pskb_expand_head(skb
, 0, 0, pri
);
1022 * skb_header_cloned - is the header a clone
1023 * @skb: buffer to check
1025 * Returns true if modifying the header part of the buffer requires
1026 * the data to be copied.
1028 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1035 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1036 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1037 return dataref
!= 1;
1041 * skb_header_release - release reference to header
1042 * @skb: buffer to operate on
1044 * Drop a reference to the header part of the buffer. This is done
1045 * by acquiring a payload reference. You must not read from the header
1046 * part of skb->data after this.
1048 static inline void skb_header_release(struct sk_buff
*skb
)
1052 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1056 * skb_shared - is the buffer shared
1057 * @skb: buffer to check
1059 * Returns true if more than one person has a reference to this
1062 static inline int skb_shared(const struct sk_buff
*skb
)
1064 return atomic_read(&skb
->users
) != 1;
1068 * skb_share_check - check if buffer is shared and if so clone it
1069 * @skb: buffer to check
1070 * @pri: priority for memory allocation
1072 * If the buffer is shared the buffer is cloned and the old copy
1073 * drops a reference. A new clone with a single reference is returned.
1074 * If the buffer is not shared the original buffer is returned. When
1075 * being called from interrupt status or with spinlocks held pri must
1078 * NULL is returned on a memory allocation failure.
1080 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1082 might_sleep_if(pri
& __GFP_WAIT
);
1083 if (skb_shared(skb
)) {
1084 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1096 * Copy shared buffers into a new sk_buff. We effectively do COW on
1097 * packets to handle cases where we have a local reader and forward
1098 * and a couple of other messy ones. The normal one is tcpdumping
1099 * a packet thats being forwarded.
1103 * skb_unshare - make a copy of a shared buffer
1104 * @skb: buffer to check
1105 * @pri: priority for memory allocation
1107 * If the socket buffer is a clone then this function creates a new
1108 * copy of the data, drops a reference count on the old copy and returns
1109 * the new copy with the reference count at 1. If the buffer is not a clone
1110 * the original buffer is returned. When called with a spinlock held or
1111 * from interrupt state @pri must be %GFP_ATOMIC
1113 * %NULL is returned on a memory allocation failure.
1115 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1118 might_sleep_if(pri
& __GFP_WAIT
);
1119 if (skb_cloned(skb
)) {
1120 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1121 kfree_skb(skb
); /* Free our shared copy */
1128 * skb_peek - peek at the head of an &sk_buff_head
1129 * @list_: list to peek at
1131 * Peek an &sk_buff. Unlike most other operations you _MUST_
1132 * be careful with this one. A peek leaves the buffer on the
1133 * list and someone else may run off with it. You must hold
1134 * the appropriate locks or have a private queue to do this.
1136 * Returns %NULL for an empty list or a pointer to the head element.
1137 * The reference count is not incremented and the reference is therefore
1138 * volatile. Use with caution.
1140 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1142 struct sk_buff
*skb
= list_
->next
;
1144 if (skb
== (struct sk_buff
*)list_
)
1150 * skb_peek_next - peek skb following the given one from a queue
1151 * @skb: skb to start from
1152 * @list_: list to peek at
1154 * Returns %NULL when the end of the list is met or a pointer to the
1155 * next element. The reference count is not incremented and the
1156 * reference is therefore volatile. Use with caution.
1158 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1159 const struct sk_buff_head
*list_
)
1161 struct sk_buff
*next
= skb
->next
;
1163 if (next
== (struct sk_buff
*)list_
)
1169 * skb_peek_tail - peek at the tail of an &sk_buff_head
1170 * @list_: list to peek at
1172 * Peek an &sk_buff. Unlike most other operations you _MUST_
1173 * be careful with this one. A peek leaves the buffer on the
1174 * list and someone else may run off with it. You must hold
1175 * the appropriate locks or have a private queue to do this.
1177 * Returns %NULL for an empty list or a pointer to the tail element.
1178 * The reference count is not incremented and the reference is therefore
1179 * volatile. Use with caution.
1181 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1183 struct sk_buff
*skb
= list_
->prev
;
1185 if (skb
== (struct sk_buff
*)list_
)
1192 * skb_queue_len - get queue length
1193 * @list_: list to measure
1195 * Return the length of an &sk_buff queue.
1197 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1203 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1204 * @list: queue to initialize
1206 * This initializes only the list and queue length aspects of
1207 * an sk_buff_head object. This allows to initialize the list
1208 * aspects of an sk_buff_head without reinitializing things like
1209 * the spinlock. It can also be used for on-stack sk_buff_head
1210 * objects where the spinlock is known to not be used.
1212 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1214 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1219 * This function creates a split out lock class for each invocation;
1220 * this is needed for now since a whole lot of users of the skb-queue
1221 * infrastructure in drivers have different locking usage (in hardirq)
1222 * than the networking core (in softirq only). In the long run either the
1223 * network layer or drivers should need annotation to consolidate the
1224 * main types of usage into 3 classes.
1226 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1228 spin_lock_init(&list
->lock
);
1229 __skb_queue_head_init(list
);
1232 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1233 struct lock_class_key
*class)
1235 skb_queue_head_init(list
);
1236 lockdep_set_class(&list
->lock
, class);
1240 * Insert an sk_buff on a list.
1242 * The "__skb_xxxx()" functions are the non-atomic ones that
1243 * can only be called with interrupts disabled.
1245 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1246 struct sk_buff_head
*list
);
1247 static inline void __skb_insert(struct sk_buff
*newsk
,
1248 struct sk_buff
*prev
, struct sk_buff
*next
,
1249 struct sk_buff_head
*list
)
1253 next
->prev
= prev
->next
= newsk
;
1257 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1258 struct sk_buff
*prev
,
1259 struct sk_buff
*next
)
1261 struct sk_buff
*first
= list
->next
;
1262 struct sk_buff
*last
= list
->prev
;
1272 * skb_queue_splice - join two skb lists, this is designed for stacks
1273 * @list: the new list to add
1274 * @head: the place to add it in the first list
1276 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1277 struct sk_buff_head
*head
)
1279 if (!skb_queue_empty(list
)) {
1280 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1281 head
->qlen
+= list
->qlen
;
1286 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1287 * @list: the new list to add
1288 * @head: the place to add it in the first list
1290 * The list at @list is reinitialised
1292 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1293 struct sk_buff_head
*head
)
1295 if (!skb_queue_empty(list
)) {
1296 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1297 head
->qlen
+= list
->qlen
;
1298 __skb_queue_head_init(list
);
1303 * skb_queue_splice_tail - join two skb lists, each list being a queue
1304 * @list: the new list to add
1305 * @head: the place to add it in the first list
1307 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1308 struct sk_buff_head
*head
)
1310 if (!skb_queue_empty(list
)) {
1311 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1312 head
->qlen
+= list
->qlen
;
1317 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1318 * @list: the new list to add
1319 * @head: the place to add it in the first list
1321 * Each of the lists is a queue.
1322 * The list at @list is reinitialised
1324 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1325 struct sk_buff_head
*head
)
1327 if (!skb_queue_empty(list
)) {
1328 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1329 head
->qlen
+= list
->qlen
;
1330 __skb_queue_head_init(list
);
1335 * __skb_queue_after - queue a buffer at the list head
1336 * @list: list to use
1337 * @prev: place after this buffer
1338 * @newsk: buffer to queue
1340 * Queue a buffer int the middle of a list. This function takes no locks
1341 * and you must therefore hold required locks before calling it.
1343 * A buffer cannot be placed on two lists at the same time.
1345 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1346 struct sk_buff
*prev
,
1347 struct sk_buff
*newsk
)
1349 __skb_insert(newsk
, prev
, prev
->next
, list
);
1352 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1353 struct sk_buff_head
*list
);
1355 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1356 struct sk_buff
*next
,
1357 struct sk_buff
*newsk
)
1359 __skb_insert(newsk
, next
->prev
, next
, list
);
1363 * __skb_queue_head - queue a buffer at the list head
1364 * @list: list to use
1365 * @newsk: buffer to queue
1367 * Queue a buffer at the start of a list. This function takes no locks
1368 * and you must therefore hold required locks before calling it.
1370 * A buffer cannot be placed on two lists at the same time.
1372 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1373 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1374 struct sk_buff
*newsk
)
1376 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1380 * __skb_queue_tail - queue a buffer at the list tail
1381 * @list: list to use
1382 * @newsk: buffer to queue
1384 * Queue a buffer at the end of a list. This function takes no locks
1385 * and you must therefore hold required locks before calling it.
1387 * A buffer cannot be placed on two lists at the same time.
1389 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1390 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1391 struct sk_buff
*newsk
)
1393 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1397 * remove sk_buff from list. _Must_ be called atomically, and with
1400 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1401 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1403 struct sk_buff
*next
, *prev
;
1408 skb
->next
= skb
->prev
= NULL
;
1414 * __skb_dequeue - remove from the head of the queue
1415 * @list: list to dequeue from
1417 * Remove the head of the list. This function does not take any locks
1418 * so must be used with appropriate locks held only. The head item is
1419 * returned or %NULL if the list is empty.
1421 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1422 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1424 struct sk_buff
*skb
= skb_peek(list
);
1426 __skb_unlink(skb
, list
);
1431 * __skb_dequeue_tail - remove from the tail of the queue
1432 * @list: list to dequeue from
1434 * Remove the tail of the list. This function does not take any locks
1435 * so must be used with appropriate locks held only. The tail item is
1436 * returned or %NULL if the list is empty.
1438 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1439 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1441 struct sk_buff
*skb
= skb_peek_tail(list
);
1443 __skb_unlink(skb
, list
);
1448 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1450 return skb
->data_len
;
1453 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1455 return skb
->len
- skb
->data_len
;
1458 static inline int skb_pagelen(const struct sk_buff
*skb
)
1462 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1463 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1464 return len
+ skb_headlen(skb
);
1468 * __skb_fill_page_desc - initialise a paged fragment in an skb
1469 * @skb: buffer containing fragment to be initialised
1470 * @i: paged fragment index to initialise
1471 * @page: the page to use for this fragment
1472 * @off: the offset to the data with @page
1473 * @size: the length of the data
1475 * Initialises the @i'th fragment of @skb to point to &size bytes at
1476 * offset @off within @page.
1478 * Does not take any additional reference on the fragment.
1480 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1481 struct page
*page
, int off
, int size
)
1483 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1486 * Propagate page->pfmemalloc to the skb if we can. The problem is
1487 * that not all callers have unique ownership of the page. If
1488 * pfmemalloc is set, we check the mapping as a mapping implies
1489 * page->index is set (index and pfmemalloc share space).
1490 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1491 * do not lose pfmemalloc information as the pages would not be
1492 * allocated using __GFP_MEMALLOC.
1494 frag
->page
.p
= page
;
1495 frag
->page_offset
= off
;
1496 skb_frag_size_set(frag
, size
);
1498 page
= compound_head(page
);
1499 if (page
->pfmemalloc
&& !page
->mapping
)
1500 skb
->pfmemalloc
= true;
1504 * skb_fill_page_desc - initialise a paged fragment in an skb
1505 * @skb: buffer containing fragment to be initialised
1506 * @i: paged fragment index to initialise
1507 * @page: the page to use for this fragment
1508 * @off: the offset to the data with @page
1509 * @size: the length of the data
1511 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1512 * @skb to point to @size bytes at offset @off within @page. In
1513 * addition updates @skb such that @i is the last fragment.
1515 * Does not take any additional reference on the fragment.
1517 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1518 struct page
*page
, int off
, int size
)
1520 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1521 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1524 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1525 int size
, unsigned int truesize
);
1527 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1528 unsigned int truesize
);
1530 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1531 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1532 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1534 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1535 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1537 return skb
->head
+ skb
->tail
;
1540 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1542 skb
->tail
= skb
->data
- skb
->head
;
1545 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1547 skb_reset_tail_pointer(skb
);
1548 skb
->tail
+= offset
;
1551 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1552 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1557 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1559 skb
->tail
= skb
->data
;
1562 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1564 skb
->tail
= skb
->data
+ offset
;
1567 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1570 * Add data to an sk_buff
1572 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1573 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1574 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1576 unsigned char *tmp
= skb_tail_pointer(skb
);
1577 SKB_LINEAR_ASSERT(skb
);
1583 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1584 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1591 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1592 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1595 BUG_ON(skb
->len
< skb
->data_len
);
1596 return skb
->data
+= len
;
1599 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1601 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1604 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1606 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1608 if (len
> skb_headlen(skb
) &&
1609 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1612 return skb
->data
+= len
;
1615 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1617 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1620 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1622 if (likely(len
<= skb_headlen(skb
)))
1624 if (unlikely(len
> skb
->len
))
1626 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1630 * skb_headroom - bytes at buffer head
1631 * @skb: buffer to check
1633 * Return the number of bytes of free space at the head of an &sk_buff.
1635 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1637 return skb
->data
- skb
->head
;
1641 * skb_tailroom - bytes at buffer end
1642 * @skb: buffer to check
1644 * Return the number of bytes of free space at the tail of an sk_buff
1646 static inline int skb_tailroom(const struct sk_buff
*skb
)
1648 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1652 * skb_availroom - bytes at buffer end
1653 * @skb: buffer to check
1655 * Return the number of bytes of free space at the tail of an sk_buff
1656 * allocated by sk_stream_alloc()
1658 static inline int skb_availroom(const struct sk_buff
*skb
)
1660 if (skb_is_nonlinear(skb
))
1663 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1667 * skb_reserve - adjust headroom
1668 * @skb: buffer to alter
1669 * @len: bytes to move
1671 * Increase the headroom of an empty &sk_buff by reducing the tail
1672 * room. This is only allowed for an empty buffer.
1674 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1680 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1682 skb
->inner_mac_header
= skb
->mac_header
;
1683 skb
->inner_network_header
= skb
->network_header
;
1684 skb
->inner_transport_header
= skb
->transport_header
;
1687 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1689 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1692 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1695 return skb
->head
+ skb
->inner_transport_header
;
1698 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1700 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1703 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1706 skb_reset_inner_transport_header(skb
);
1707 skb
->inner_transport_header
+= offset
;
1710 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1712 return skb
->head
+ skb
->inner_network_header
;
1715 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1717 skb
->inner_network_header
= skb
->data
- skb
->head
;
1720 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1723 skb_reset_inner_network_header(skb
);
1724 skb
->inner_network_header
+= offset
;
1727 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
1729 return skb
->head
+ skb
->inner_mac_header
;
1732 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
1734 skb
->inner_mac_header
= skb
->data
- skb
->head
;
1737 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
1740 skb_reset_inner_mac_header(skb
);
1741 skb
->inner_mac_header
+= offset
;
1743 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1745 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
1748 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1750 return skb
->head
+ skb
->transport_header
;
1753 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1755 skb
->transport_header
= skb
->data
- skb
->head
;
1758 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1761 skb_reset_transport_header(skb
);
1762 skb
->transport_header
+= offset
;
1765 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1767 return skb
->head
+ skb
->network_header
;
1770 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1772 skb
->network_header
= skb
->data
- skb
->head
;
1775 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1777 skb_reset_network_header(skb
);
1778 skb
->network_header
+= offset
;
1781 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1783 return skb
->head
+ skb
->mac_header
;
1786 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1788 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
1791 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1793 skb
->mac_header
= skb
->data
- skb
->head
;
1796 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1798 skb_reset_mac_header(skb
);
1799 skb
->mac_header
+= offset
;
1802 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
1804 skb
->mac_header
= skb
->network_header
;
1807 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
1808 const int offset_hint
)
1810 struct flow_keys keys
;
1812 if (skb_transport_header_was_set(skb
))
1814 else if (skb_flow_dissect(skb
, &keys
))
1815 skb_set_transport_header(skb
, keys
.thoff
);
1817 skb_set_transport_header(skb
, offset_hint
);
1820 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1822 if (skb_mac_header_was_set(skb
)) {
1823 const unsigned char *old_mac
= skb_mac_header(skb
);
1825 skb_set_mac_header(skb
, -skb
->mac_len
);
1826 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1830 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1832 return skb
->csum_start
- skb_headroom(skb
);
1835 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1837 return skb_transport_header(skb
) - skb
->data
;
1840 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1842 return skb
->transport_header
- skb
->network_header
;
1845 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1847 return skb
->inner_transport_header
- skb
->inner_network_header
;
1850 static inline int skb_network_offset(const struct sk_buff
*skb
)
1852 return skb_network_header(skb
) - skb
->data
;
1855 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1857 return skb_inner_network_header(skb
) - skb
->data
;
1860 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1862 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1865 static inline void skb_pop_rcv_encapsulation(struct sk_buff
*skb
)
1867 /* Only continue with checksum unnecessary if device indicated
1868 * it is valid across encapsulation (skb->encapsulation was set).
1870 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
&& !skb
->encapsulation
)
1871 skb
->ip_summed
= CHECKSUM_NONE
;
1873 skb
->encapsulation
= 0;
1874 skb
->csum_valid
= 0;
1878 * CPUs often take a performance hit when accessing unaligned memory
1879 * locations. The actual performance hit varies, it can be small if the
1880 * hardware handles it or large if we have to take an exception and fix it
1883 * Since an ethernet header is 14 bytes network drivers often end up with
1884 * the IP header at an unaligned offset. The IP header can be aligned by
1885 * shifting the start of the packet by 2 bytes. Drivers should do this
1888 * skb_reserve(skb, NET_IP_ALIGN);
1890 * The downside to this alignment of the IP header is that the DMA is now
1891 * unaligned. On some architectures the cost of an unaligned DMA is high
1892 * and this cost outweighs the gains made by aligning the IP header.
1894 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1897 #ifndef NET_IP_ALIGN
1898 #define NET_IP_ALIGN 2
1902 * The networking layer reserves some headroom in skb data (via
1903 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1904 * the header has to grow. In the default case, if the header has to grow
1905 * 32 bytes or less we avoid the reallocation.
1907 * Unfortunately this headroom changes the DMA alignment of the resulting
1908 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1909 * on some architectures. An architecture can override this value,
1910 * perhaps setting it to a cacheline in size (since that will maintain
1911 * cacheline alignment of the DMA). It must be a power of 2.
1913 * Various parts of the networking layer expect at least 32 bytes of
1914 * headroom, you should not reduce this.
1916 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1917 * to reduce average number of cache lines per packet.
1918 * get_rps_cpus() for example only access one 64 bytes aligned block :
1919 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1922 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1925 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1927 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1929 if (unlikely(skb_is_nonlinear(skb
))) {
1934 skb_set_tail_pointer(skb
, len
);
1937 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1939 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1942 return ___pskb_trim(skb
, len
);
1943 __skb_trim(skb
, len
);
1947 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1949 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1953 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1954 * @skb: buffer to alter
1957 * This is identical to pskb_trim except that the caller knows that
1958 * the skb is not cloned so we should never get an error due to out-
1961 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1963 int err
= pskb_trim(skb
, len
);
1968 * skb_orphan - orphan a buffer
1969 * @skb: buffer to orphan
1971 * If a buffer currently has an owner then we call the owner's
1972 * destructor function and make the @skb unowned. The buffer continues
1973 * to exist but is no longer charged to its former owner.
1975 static inline void skb_orphan(struct sk_buff
*skb
)
1977 if (skb
->destructor
) {
1978 skb
->destructor(skb
);
1979 skb
->destructor
= NULL
;
1987 * skb_orphan_frags - orphan the frags contained in a buffer
1988 * @skb: buffer to orphan frags from
1989 * @gfp_mask: allocation mask for replacement pages
1991 * For each frag in the SKB which needs a destructor (i.e. has an
1992 * owner) create a copy of that frag and release the original
1993 * page by calling the destructor.
1995 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
1997 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
1999 return skb_copy_ubufs(skb
, gfp_mask
);
2003 * __skb_queue_purge - empty a list
2004 * @list: list to empty
2006 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2007 * the list and one reference dropped. This function does not take the
2008 * list lock and the caller must hold the relevant locks to use it.
2010 void skb_queue_purge(struct sk_buff_head
*list
);
2011 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2013 struct sk_buff
*skb
;
2014 while ((skb
= __skb_dequeue(list
)) != NULL
)
2018 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2019 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2020 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2022 void *netdev_alloc_frag(unsigned int fragsz
);
2024 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2028 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2029 * @dev: network device to receive on
2030 * @length: length to allocate
2032 * Allocate a new &sk_buff and assign it a usage count of one. The
2033 * buffer has unspecified headroom built in. Users should allocate
2034 * the headroom they think they need without accounting for the
2035 * built in space. The built in space is used for optimisations.
2037 * %NULL is returned if there is no free memory. Although this function
2038 * allocates memory it can be called from an interrupt.
2040 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2041 unsigned int length
)
2043 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2046 /* legacy helper around __netdev_alloc_skb() */
2047 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2050 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2053 /* legacy helper around netdev_alloc_skb() */
2054 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2056 return netdev_alloc_skb(NULL
, length
);
2060 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2061 unsigned int length
, gfp_t gfp
)
2063 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2065 if (NET_IP_ALIGN
&& skb
)
2066 skb_reserve(skb
, NET_IP_ALIGN
);
2070 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2071 unsigned int length
)
2073 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2077 * __skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data
2078 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2079 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2080 * @order: size of the allocation
2082 * Allocate a new page.
2084 * %NULL is returned if there is no free memory.
2086 static inline struct page
*__skb_alloc_pages(gfp_t gfp_mask
,
2087 struct sk_buff
*skb
,
2092 gfp_mask
|= __GFP_COLD
;
2094 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2095 gfp_mask
|= __GFP_MEMALLOC
;
2097 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2098 if (skb
&& page
&& page
->pfmemalloc
)
2099 skb
->pfmemalloc
= true;
2105 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
2106 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2107 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2109 * Allocate a new page.
2111 * %NULL is returned if there is no free memory.
2113 static inline struct page
*__skb_alloc_page(gfp_t gfp_mask
,
2114 struct sk_buff
*skb
)
2116 return __skb_alloc_pages(gfp_mask
, skb
, 0);
2120 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2121 * @page: The page that was allocated from skb_alloc_page
2122 * @skb: The skb that may need pfmemalloc set
2124 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2125 struct sk_buff
*skb
)
2127 if (page
&& page
->pfmemalloc
)
2128 skb
->pfmemalloc
= true;
2132 * skb_frag_page - retrieve the page referred to by a paged fragment
2133 * @frag: the paged fragment
2135 * Returns the &struct page associated with @frag.
2137 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2139 return frag
->page
.p
;
2143 * __skb_frag_ref - take an addition reference on a paged fragment.
2144 * @frag: the paged fragment
2146 * Takes an additional reference on the paged fragment @frag.
2148 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2150 get_page(skb_frag_page(frag
));
2154 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2156 * @f: the fragment offset.
2158 * Takes an additional reference on the @f'th paged fragment of @skb.
2160 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2162 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2166 * __skb_frag_unref - release a reference on a paged fragment.
2167 * @frag: the paged fragment
2169 * Releases a reference on the paged fragment @frag.
2171 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2173 put_page(skb_frag_page(frag
));
2177 * skb_frag_unref - release a reference on a paged fragment of an skb.
2179 * @f: the fragment offset
2181 * Releases a reference on the @f'th paged fragment of @skb.
2183 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2185 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2189 * skb_frag_address - gets the address of the data contained in a paged fragment
2190 * @frag: the paged fragment buffer
2192 * Returns the address of the data within @frag. The page must already
2195 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2197 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2201 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2202 * @frag: the paged fragment buffer
2204 * Returns the address of the data within @frag. Checks that the page
2205 * is mapped and returns %NULL otherwise.
2207 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2209 void *ptr
= page_address(skb_frag_page(frag
));
2213 return ptr
+ frag
->page_offset
;
2217 * __skb_frag_set_page - sets the page contained in a paged fragment
2218 * @frag: the paged fragment
2219 * @page: the page to set
2221 * Sets the fragment @frag to contain @page.
2223 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2225 frag
->page
.p
= page
;
2229 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2231 * @f: the fragment offset
2232 * @page: the page to set
2234 * Sets the @f'th fragment of @skb to contain @page.
2236 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2239 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2242 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2245 * skb_frag_dma_map - maps a paged fragment via the DMA API
2246 * @dev: the device to map the fragment to
2247 * @frag: the paged fragment to map
2248 * @offset: the offset within the fragment (starting at the
2249 * fragment's own offset)
2250 * @size: the number of bytes to map
2251 * @dir: the direction of the mapping (%PCI_DMA_*)
2253 * Maps the page associated with @frag to @device.
2255 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2256 const skb_frag_t
*frag
,
2257 size_t offset
, size_t size
,
2258 enum dma_data_direction dir
)
2260 return dma_map_page(dev
, skb_frag_page(frag
),
2261 frag
->page_offset
+ offset
, size
, dir
);
2264 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2267 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2271 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2274 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2279 * skb_clone_writable - is the header of a clone writable
2280 * @skb: buffer to check
2281 * @len: length up to which to write
2283 * Returns true if modifying the header part of the cloned buffer
2284 * does not requires the data to be copied.
2286 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2288 return !skb_header_cloned(skb
) &&
2289 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2292 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2297 if (headroom
> skb_headroom(skb
))
2298 delta
= headroom
- skb_headroom(skb
);
2300 if (delta
|| cloned
)
2301 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2307 * skb_cow - copy header of skb when it is required
2308 * @skb: buffer to cow
2309 * @headroom: needed headroom
2311 * If the skb passed lacks sufficient headroom or its data part
2312 * is shared, data is reallocated. If reallocation fails, an error
2313 * is returned and original skb is not changed.
2315 * The result is skb with writable area skb->head...skb->tail
2316 * and at least @headroom of space at head.
2318 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2320 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2324 * skb_cow_head - skb_cow but only making the head writable
2325 * @skb: buffer to cow
2326 * @headroom: needed headroom
2328 * This function is identical to skb_cow except that we replace the
2329 * skb_cloned check by skb_header_cloned. It should be used when
2330 * you only need to push on some header and do not need to modify
2333 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2335 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2339 * skb_padto - pad an skbuff up to a minimal size
2340 * @skb: buffer to pad
2341 * @len: minimal length
2343 * Pads up a buffer to ensure the trailing bytes exist and are
2344 * blanked. If the buffer already contains sufficient data it
2345 * is untouched. Otherwise it is extended. Returns zero on
2346 * success. The skb is freed on error.
2349 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2351 unsigned int size
= skb
->len
;
2352 if (likely(size
>= len
))
2354 return skb_pad(skb
, len
- size
);
2357 static inline int skb_add_data(struct sk_buff
*skb
,
2358 char __user
*from
, int copy
)
2360 const int off
= skb
->len
;
2362 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2364 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
2367 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2370 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
2373 __skb_trim(skb
, off
);
2377 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2378 const struct page
*page
, int off
)
2381 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2383 return page
== skb_frag_page(frag
) &&
2384 off
== frag
->page_offset
+ skb_frag_size(frag
);
2389 static inline int __skb_linearize(struct sk_buff
*skb
)
2391 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2395 * skb_linearize - convert paged skb to linear one
2396 * @skb: buffer to linarize
2398 * If there is no free memory -ENOMEM is returned, otherwise zero
2399 * is returned and the old skb data released.
2401 static inline int skb_linearize(struct sk_buff
*skb
)
2403 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2407 * skb_has_shared_frag - can any frag be overwritten
2408 * @skb: buffer to test
2410 * Return true if the skb has at least one frag that might be modified
2411 * by an external entity (as in vmsplice()/sendfile())
2413 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2415 return skb_is_nonlinear(skb
) &&
2416 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2420 * skb_linearize_cow - make sure skb is linear and writable
2421 * @skb: buffer to process
2423 * If there is no free memory -ENOMEM is returned, otherwise zero
2424 * is returned and the old skb data released.
2426 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2428 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2429 __skb_linearize(skb
) : 0;
2433 * skb_postpull_rcsum - update checksum for received skb after pull
2434 * @skb: buffer to update
2435 * @start: start of data before pull
2436 * @len: length of data pulled
2438 * After doing a pull on a received packet, you need to call this to
2439 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2440 * CHECKSUM_NONE so that it can be recomputed from scratch.
2443 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2444 const void *start
, unsigned int len
)
2446 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2447 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2450 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2453 * pskb_trim_rcsum - trim received skb and update checksum
2454 * @skb: buffer to trim
2457 * This is exactly the same as pskb_trim except that it ensures the
2458 * checksum of received packets are still valid after the operation.
2461 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2463 if (likely(len
>= skb
->len
))
2465 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2466 skb
->ip_summed
= CHECKSUM_NONE
;
2467 return __pskb_trim(skb
, len
);
2470 #define skb_queue_walk(queue, skb) \
2471 for (skb = (queue)->next; \
2472 skb != (struct sk_buff *)(queue); \
2475 #define skb_queue_walk_safe(queue, skb, tmp) \
2476 for (skb = (queue)->next, tmp = skb->next; \
2477 skb != (struct sk_buff *)(queue); \
2478 skb = tmp, tmp = skb->next)
2480 #define skb_queue_walk_from(queue, skb) \
2481 for (; skb != (struct sk_buff *)(queue); \
2484 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2485 for (tmp = skb->next; \
2486 skb != (struct sk_buff *)(queue); \
2487 skb = tmp, tmp = skb->next)
2489 #define skb_queue_reverse_walk(queue, skb) \
2490 for (skb = (queue)->prev; \
2491 skb != (struct sk_buff *)(queue); \
2494 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2495 for (skb = (queue)->prev, tmp = skb->prev; \
2496 skb != (struct sk_buff *)(queue); \
2497 skb = tmp, tmp = skb->prev)
2499 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2500 for (tmp = skb->prev; \
2501 skb != (struct sk_buff *)(queue); \
2502 skb = tmp, tmp = skb->prev)
2504 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2506 return skb_shinfo(skb
)->frag_list
!= NULL
;
2509 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2511 skb_shinfo(skb
)->frag_list
= NULL
;
2514 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2516 frag
->next
= skb_shinfo(skb
)->frag_list
;
2517 skb_shinfo(skb
)->frag_list
= frag
;
2520 #define skb_walk_frags(skb, iter) \
2521 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2523 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2524 int *peeked
, int *off
, int *err
);
2525 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
2527 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2528 struct poll_table_struct
*wait
);
2529 int skb_copy_datagram_iovec(const struct sk_buff
*from
, int offset
,
2530 struct iovec
*to
, int size
);
2531 int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
, int hlen
,
2533 int skb_copy_datagram_from_iovec(struct sk_buff
*skb
, int offset
,
2534 const struct iovec
*from
, int from_offset
,
2536 int zerocopy_sg_from_iovec(struct sk_buff
*skb
, const struct iovec
*frm
,
2537 int offset
, size_t count
);
2538 int skb_copy_datagram_const_iovec(const struct sk_buff
*from
, int offset
,
2539 const struct iovec
*to
, int to_offset
,
2541 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2542 void skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
);
2543 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
2544 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
2545 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
2546 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
2547 int len
, __wsum csum
);
2548 int skb_splice_bits(struct sk_buff
*skb
, unsigned int offset
,
2549 struct pipe_inode_info
*pipe
, unsigned int len
,
2550 unsigned int flags
);
2551 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2552 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
2553 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
2555 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
2556 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
2557 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
2558 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
2559 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
2560 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
2562 struct skb_checksum_ops
{
2563 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
2564 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
2567 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2568 __wsum csum
, const struct skb_checksum_ops
*ops
);
2569 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2572 static inline void *__skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2573 int len
, void *data
, int hlen
, void *buffer
)
2575 if (hlen
- offset
>= len
)
2576 return data
+ offset
;
2579 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2585 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2586 int len
, void *buffer
)
2588 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
2589 skb_headlen(skb
), buffer
);
2593 * skb_needs_linearize - check if we need to linearize a given skb
2594 * depending on the given device features.
2595 * @skb: socket buffer to check
2596 * @features: net device features
2598 * Returns true if either:
2599 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2600 * 2. skb is fragmented and the device does not support SG.
2602 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
2603 netdev_features_t features
)
2605 return skb_is_nonlinear(skb
) &&
2606 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
2607 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
2610 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2612 const unsigned int len
)
2614 memcpy(to
, skb
->data
, len
);
2617 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2618 const int offset
, void *to
,
2619 const unsigned int len
)
2621 memcpy(to
, skb
->data
+ offset
, len
);
2624 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2626 const unsigned int len
)
2628 memcpy(skb
->data
, from
, len
);
2631 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2634 const unsigned int len
)
2636 memcpy(skb
->data
+ offset
, from
, len
);
2639 void skb_init(void);
2641 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2647 * skb_get_timestamp - get timestamp from a skb
2648 * @skb: skb to get stamp from
2649 * @stamp: pointer to struct timeval to store stamp in
2651 * Timestamps are stored in the skb as offsets to a base timestamp.
2652 * This function converts the offset back to a struct timeval and stores
2655 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2656 struct timeval
*stamp
)
2658 *stamp
= ktime_to_timeval(skb
->tstamp
);
2661 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2662 struct timespec
*stamp
)
2664 *stamp
= ktime_to_timespec(skb
->tstamp
);
2667 static inline void __net_timestamp(struct sk_buff
*skb
)
2669 skb
->tstamp
= ktime_get_real();
2672 static inline ktime_t
net_timedelta(ktime_t t
)
2674 return ktime_sub(ktime_get_real(), t
);
2677 static inline ktime_t
net_invalid_timestamp(void)
2679 return ktime_set(0, 0);
2682 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2684 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2685 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2687 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2689 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2693 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2698 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2701 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2703 * PHY drivers may accept clones of transmitted packets for
2704 * timestamping via their phy_driver.txtstamp method. These drivers
2705 * must call this function to return the skb back to the stack, with
2706 * or without a timestamp.
2708 * @skb: clone of the the original outgoing packet
2709 * @hwtstamps: hardware time stamps, may be NULL if not available
2712 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2713 struct skb_shared_hwtstamps
*hwtstamps
);
2715 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
2716 struct skb_shared_hwtstamps
*hwtstamps
,
2717 struct sock
*sk
, int tstype
);
2720 * skb_tstamp_tx - queue clone of skb with send time stamps
2721 * @orig_skb: the original outgoing packet
2722 * @hwtstamps: hardware time stamps, may be NULL if not available
2724 * If the skb has a socket associated, then this function clones the
2725 * skb (thus sharing the actual data and optional structures), stores
2726 * the optional hardware time stamping information (if non NULL) or
2727 * generates a software time stamp (otherwise), then queues the clone
2728 * to the error queue of the socket. Errors are silently ignored.
2730 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2731 struct skb_shared_hwtstamps
*hwtstamps
);
2733 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2735 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2736 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2737 skb_tstamp_tx(skb
, NULL
);
2741 * skb_tx_timestamp() - Driver hook for transmit timestamping
2743 * Ethernet MAC Drivers should call this function in their hard_xmit()
2744 * function immediately before giving the sk_buff to the MAC hardware.
2746 * Specifically, one should make absolutely sure that this function is
2747 * called before TX completion of this packet can trigger. Otherwise
2748 * the packet could potentially already be freed.
2750 * @skb: A socket buffer.
2752 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2754 skb_clone_tx_timestamp(skb
);
2755 sw_tx_timestamp(skb
);
2759 * skb_complete_wifi_ack - deliver skb with wifi status
2761 * @skb: the original outgoing packet
2762 * @acked: ack status
2765 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2767 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2768 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2770 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2772 return ((skb
->ip_summed
& CHECKSUM_UNNECESSARY
) || skb
->csum_valid
);
2776 * skb_checksum_complete - Calculate checksum of an entire packet
2777 * @skb: packet to process
2779 * This function calculates the checksum over the entire packet plus
2780 * the value of skb->csum. The latter can be used to supply the
2781 * checksum of a pseudo header as used by TCP/UDP. It returns the
2784 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2785 * this function can be used to verify that checksum on received
2786 * packets. In that case the function should return zero if the
2787 * checksum is correct. In particular, this function will return zero
2788 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2789 * hardware has already verified the correctness of the checksum.
2791 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2793 return skb_csum_unnecessary(skb
) ?
2794 0 : __skb_checksum_complete(skb
);
2797 /* Check if we need to perform checksum complete validation.
2799 * Returns true if checksum complete is needed, false otherwise
2800 * (either checksum is unnecessary or zero checksum is allowed).
2802 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
2806 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
2807 skb
->csum_valid
= 1;
2814 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
2817 #define CHECKSUM_BREAK 76
2819 /* Validate (init) checksum based on checksum complete.
2822 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
2823 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
2824 * checksum is stored in skb->csum for use in __skb_checksum_complete
2825 * non-zero: value of invalid checksum
2828 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
2832 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
2833 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
2834 skb
->csum_valid
= 1;
2841 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
2844 csum
= __skb_checksum_complete(skb
);
2845 skb
->csum_valid
= !csum
;
2852 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
2857 /* Perform checksum validate (init). Note that this is a macro since we only
2858 * want to calculate the pseudo header which is an input function if necessary.
2859 * First we try to validate without any computation (checksum unnecessary) and
2860 * then calculate based on checksum complete calling the function to compute
2864 * 0: checksum is validated or try to in skb_checksum_complete
2865 * non-zero: value of invalid checksum
2867 #define __skb_checksum_validate(skb, proto, complete, \
2868 zero_okay, check, compute_pseudo) \
2870 __sum16 __ret = 0; \
2871 skb->csum_valid = 0; \
2872 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
2873 __ret = __skb_checksum_validate_complete(skb, \
2874 complete, compute_pseudo(skb, proto)); \
2878 #define skb_checksum_init(skb, proto, compute_pseudo) \
2879 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
2881 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
2882 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
2884 #define skb_checksum_validate(skb, proto, compute_pseudo) \
2885 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
2887 #define skb_checksum_validate_zero_check(skb, proto, check, \
2889 __skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo)
2891 #define skb_checksum_simple_validate(skb) \
2892 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
2894 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2895 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
2896 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
2898 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
2899 nf_conntrack_destroy(nfct
);
2901 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
2904 atomic_inc(&nfct
->use
);
2907 #ifdef CONFIG_BRIDGE_NETFILTER
2908 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
2910 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
2913 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
2916 atomic_inc(&nf_bridge
->use
);
2918 #endif /* CONFIG_BRIDGE_NETFILTER */
2919 static inline void nf_reset(struct sk_buff
*skb
)
2921 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2922 nf_conntrack_put(skb
->nfct
);
2925 #ifdef CONFIG_BRIDGE_NETFILTER
2926 nf_bridge_put(skb
->nf_bridge
);
2927 skb
->nf_bridge
= NULL
;
2931 static inline void nf_reset_trace(struct sk_buff
*skb
)
2933 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
2938 /* Note: This doesn't put any conntrack and bridge info in dst. */
2939 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2941 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2942 dst
->nfct
= src
->nfct
;
2943 nf_conntrack_get(src
->nfct
);
2944 dst
->nfctinfo
= src
->nfctinfo
;
2946 #ifdef CONFIG_BRIDGE_NETFILTER
2947 dst
->nf_bridge
= src
->nf_bridge
;
2948 nf_bridge_get(src
->nf_bridge
);
2950 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
2951 dst
->nf_trace
= src
->nf_trace
;
2955 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
2957 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2958 nf_conntrack_put(dst
->nfct
);
2960 #ifdef CONFIG_BRIDGE_NETFILTER
2961 nf_bridge_put(dst
->nf_bridge
);
2963 __nf_copy(dst
, src
);
2966 #ifdef CONFIG_NETWORK_SECMARK
2967 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2969 to
->secmark
= from
->secmark
;
2972 static inline void skb_init_secmark(struct sk_buff
*skb
)
2977 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
2980 static inline void skb_init_secmark(struct sk_buff
*skb
)
2984 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
2986 return !skb
->destructor
&&
2987 #if IS_ENABLED(CONFIG_XFRM)
2990 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
2993 !skb
->_skb_refdst
&&
2994 !skb_has_frag_list(skb
);
2997 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
2999 skb
->queue_mapping
= queue_mapping
;
3002 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3004 return skb
->queue_mapping
;
3007 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3009 to
->queue_mapping
= from
->queue_mapping
;
3012 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3014 skb
->queue_mapping
= rx_queue
+ 1;
3017 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3019 return skb
->queue_mapping
- 1;
3022 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3024 return skb
->queue_mapping
!= 0;
3027 u16
__skb_tx_hash(const struct net_device
*dev
, struct sk_buff
*skb
,
3028 unsigned int num_tx_queues
);
3030 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3039 /* Keeps track of mac header offset relative to skb->head.
3040 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3041 * For non-tunnel skb it points to skb_mac_header() and for
3042 * tunnel skb it points to outer mac header.
3043 * Keeps track of level of encapsulation of network headers.
3050 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3052 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3054 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3055 SKB_GSO_CB(inner_skb
)->mac_offset
;
3058 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3060 int new_headroom
, headroom
;
3063 headroom
= skb_headroom(skb
);
3064 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3068 new_headroom
= skb_headroom(skb
);
3069 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3073 /* Compute the checksum for a gso segment. First compute the checksum value
3074 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3075 * then add in skb->csum (checksum from csum_start to end of packet).
3076 * skb->csum and csum_start are then updated to reflect the checksum of the
3077 * resultant packet starting from the transport header-- the resultant checksum
3078 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3081 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3083 int plen
= SKB_GSO_CB(skb
)->csum_start
- skb_headroom(skb
) -
3084 skb_transport_offset(skb
);
3087 csum
= csum_fold(csum_partial(skb_transport_header(skb
),
3090 SKB_GSO_CB(skb
)->csum_start
-= plen
;
3095 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3097 return skb_shinfo(skb
)->gso_size
;
3100 /* Note: Should be called only if skb_is_gso(skb) is true */
3101 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3103 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3106 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3108 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3110 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3111 * wanted then gso_type will be set. */
3112 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3114 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3115 unlikely(shinfo
->gso_type
== 0)) {
3116 __skb_warn_lro_forwarding(skb
);
3122 static inline void skb_forward_csum(struct sk_buff
*skb
)
3124 /* Unfortunately we don't support this one. Any brave souls? */
3125 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3126 skb
->ip_summed
= CHECKSUM_NONE
;
3130 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3131 * @skb: skb to check
3133 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3134 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3135 * use this helper, to document places where we make this assertion.
3137 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3140 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3144 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3146 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3148 u32
__skb_get_poff(const struct sk_buff
*skb
);
3151 * skb_head_is_locked - Determine if the skb->head is locked down
3152 * @skb: skb to check
3154 * The head on skbs build around a head frag can be removed if they are
3155 * not cloned. This function returns true if the skb head is locked down
3156 * due to either being allocated via kmalloc, or by being a clone with
3157 * multiple references to the head.
3159 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3161 return !skb
->head_frag
|| skb_cloned(skb
);
3165 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3169 * skb_gso_network_seglen is used to determine the real size of the
3170 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3172 * The MAC/L2 header is not accounted for.
3174 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3176 unsigned int hdr_len
= skb_transport_header(skb
) -
3177 skb_network_header(skb
);
3178 return hdr_len
+ skb_gso_transport_seglen(skb
);
3180 #endif /* __KERNEL__ */
3181 #endif /* _LINUX_SKBUFF_H */