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>
23 #include <linux/rbtree.h>
24 #include <linux/socket.h>
26 #include <linux/atomic.h>
27 #include <asm/types.h>
28 #include <linux/spinlock.h>
29 #include <linux/net.h>
30 #include <linux/textsearch.h>
31 #include <net/checksum.h>
32 #include <linux/rcupdate.h>
33 #include <linux/hrtimer.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/netdev_features.h>
36 #include <linux/sched.h>
37 #include <net/flow_keys.h>
39 /* A. Checksumming of received packets by device.
43 * Device failed to checksum this packet e.g. due to lack of capabilities.
44 * The packet contains full (though not verified) checksum in packet but
45 * not in skb->csum. Thus, skb->csum is undefined in this case.
47 * CHECKSUM_UNNECESSARY:
49 * The hardware you're dealing with doesn't calculate the full checksum
50 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
51 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
52 * if their checksums are okay. skb->csum is still undefined in this case
53 * though. It is a bad option, but, unfortunately, nowadays most vendors do
54 * this. Apparently with the secret goal to sell you new devices, when you
55 * will add new protocol to your host, f.e. IPv6 8)
57 * CHECKSUM_UNNECESSARY is applicable to following protocols:
59 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
60 * zero UDP checksum for either IPv4 or IPv6, the networking stack
61 * may perform further validation in this case.
62 * GRE: only if the checksum is present in the header.
63 * SCTP: indicates the CRC in SCTP header has been validated.
65 * skb->csum_level indicates the number of consecutive checksums found in
66 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
67 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
68 * and a device is able to verify the checksums for UDP (possibly zero),
69 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
70 * two. If the device were only able to verify the UDP checksum and not
71 * GRE, either because it doesn't support GRE checksum of because GRE
72 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
73 * not considered in this case).
77 * This is the most generic way. The device supplied checksum of the _whole_
78 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
79 * hardware doesn't need to parse L3/L4 headers to implement this.
81 * Note: Even if device supports only some protocols, but is able to produce
82 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
86 * A checksum is set up to be offloaded to a device as described in the
87 * output description for CHECKSUM_PARTIAL. This may occur on a packet
88 * received directly from another Linux OS, e.g., a virtualized Linux kernel
89 * on the same host, or it may be set in the input path in GRO or remote
90 * checksum offload. For the purposes of checksum verification, the checksum
91 * referred to by skb->csum_start + skb->csum_offset and any preceding
92 * checksums in the packet are considered verified. Any checksums in the
93 * packet that are after the checksum being offloaded are not considered to
96 * B. Checksumming on output.
100 * The skb was already checksummed by the protocol, or a checksum is not
105 * The device is required to checksum the packet as seen by hard_start_xmit()
106 * from skb->csum_start up to the end, and to record/write the checksum at
107 * offset skb->csum_start + skb->csum_offset.
109 * The device must show its capabilities in dev->features, set up at device
110 * setup time, e.g. netdev_features.h:
112 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
113 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
114 * IPv4. Sigh. Vendors like this way for an unknown reason.
115 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
116 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
117 * NETIF_F_... - Well, you get the picture.
119 * CHECKSUM_UNNECESSARY:
121 * Normally, the device will do per protocol specific checksumming. Protocol
122 * implementations that do not want the NIC to perform the checksum
123 * calculation should use this flag in their outgoing skbs.
125 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
126 * offload. Correspondingly, the FCoE protocol driver
127 * stack should use CHECKSUM_UNNECESSARY.
129 * Any questions? No questions, good. --ANK
132 /* Don't change this without changing skb_csum_unnecessary! */
133 #define CHECKSUM_NONE 0
134 #define CHECKSUM_UNNECESSARY 1
135 #define CHECKSUM_COMPLETE 2
136 #define CHECKSUM_PARTIAL 3
138 /* Maximum value in skb->csum_level */
139 #define SKB_MAX_CSUM_LEVEL 3
141 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
142 #define SKB_WITH_OVERHEAD(X) \
143 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
144 #define SKB_MAX_ORDER(X, ORDER) \
145 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
146 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
147 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
149 /* return minimum truesize of one skb containing X bytes of data */
150 #define SKB_TRUESIZE(X) ((X) + \
151 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
152 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
156 struct pipe_inode_info
;
160 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
161 struct nf_conntrack
{
166 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
167 struct nf_bridge_info
{
170 struct net_device
*physindev
;
171 struct net_device
*physoutdev
;
172 unsigned long data
[32 / sizeof(unsigned long)];
176 struct sk_buff_head
{
177 /* These two members must be first. */
178 struct sk_buff
*next
;
179 struct sk_buff
*prev
;
187 /* To allow 64K frame to be packed as single skb without frag_list we
188 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
189 * buffers which do not start on a page boundary.
191 * Since GRO uses frags we allocate at least 16 regardless of page
194 #if (65536/PAGE_SIZE + 1) < 16
195 #define MAX_SKB_FRAGS 16UL
197 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
200 typedef struct skb_frag_struct skb_frag_t
;
202 struct skb_frag_struct
{
206 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
215 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
220 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
225 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
230 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
235 #define HAVE_HW_TIME_STAMP
238 * struct skb_shared_hwtstamps - hardware time stamps
239 * @hwtstamp: hardware time stamp transformed into duration
240 * since arbitrary point in time
242 * Software time stamps generated by ktime_get_real() are stored in
245 * hwtstamps can only be compared against other hwtstamps from
248 * This structure is attached to packets as part of the
249 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
251 struct skb_shared_hwtstamps
{
255 /* Definitions for tx_flags in struct skb_shared_info */
257 /* generate hardware time stamp */
258 SKBTX_HW_TSTAMP
= 1 << 0,
260 /* generate software time stamp when queueing packet to NIC */
261 SKBTX_SW_TSTAMP
= 1 << 1,
263 /* device driver is going to provide hardware time stamp */
264 SKBTX_IN_PROGRESS
= 1 << 2,
266 /* device driver supports TX zero-copy buffers */
267 SKBTX_DEV_ZEROCOPY
= 1 << 3,
269 /* generate wifi status information (where possible) */
270 SKBTX_WIFI_STATUS
= 1 << 4,
272 /* This indicates at least one fragment might be overwritten
273 * (as in vmsplice(), sendfile() ...)
274 * If we need to compute a TX checksum, we'll need to copy
275 * all frags to avoid possible bad checksum
277 SKBTX_SHARED_FRAG
= 1 << 5,
279 /* generate software time stamp when entering packet scheduling */
280 SKBTX_SCHED_TSTAMP
= 1 << 6,
282 /* generate software timestamp on peer data acknowledgment */
283 SKBTX_ACK_TSTAMP
= 1 << 7,
286 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
287 SKBTX_SCHED_TSTAMP | \
289 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
292 * The callback notifies userspace to release buffers when skb DMA is done in
293 * lower device, the skb last reference should be 0 when calling this.
294 * The zerocopy_success argument is true if zero copy transmit occurred,
295 * false on data copy or out of memory error caused by data copy attempt.
296 * The ctx field is used to track device context.
297 * The desc field is used to track userspace buffer index.
300 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
305 /* This data is invariant across clones and lives at
306 * the end of the header data, ie. at skb->end.
308 struct skb_shared_info
{
309 unsigned char nr_frags
;
311 unsigned short gso_size
;
312 /* Warning: this field is not always filled in (UFO)! */
313 unsigned short gso_segs
;
314 unsigned short gso_type
;
315 struct sk_buff
*frag_list
;
316 struct skb_shared_hwtstamps hwtstamps
;
321 * Warning : all fields before dataref are cleared in __alloc_skb()
325 /* Intermediate layers must ensure that destructor_arg
326 * remains valid until skb destructor */
327 void * destructor_arg
;
329 /* must be last field, see pskb_expand_head() */
330 skb_frag_t frags
[MAX_SKB_FRAGS
];
333 /* We divide dataref into two halves. The higher 16 bits hold references
334 * to the payload part of skb->data. The lower 16 bits hold references to
335 * the entire skb->data. A clone of a headerless skb holds the length of
336 * the header in skb->hdr_len.
338 * All users must obey the rule that the skb->data reference count must be
339 * greater than or equal to the payload reference count.
341 * Holding a reference to the payload part means that the user does not
342 * care about modifications to the header part of skb->data.
344 #define SKB_DATAREF_SHIFT 16
345 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
349 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
350 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
351 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
355 SKB_GSO_TCPV4
= 1 << 0,
356 SKB_GSO_UDP
= 1 << 1,
358 /* This indicates the skb is from an untrusted source. */
359 SKB_GSO_DODGY
= 1 << 2,
361 /* This indicates the tcp segment has CWR set. */
362 SKB_GSO_TCP_ECN
= 1 << 3,
364 SKB_GSO_TCPV6
= 1 << 4,
366 SKB_GSO_FCOE
= 1 << 5,
368 SKB_GSO_GRE
= 1 << 6,
370 SKB_GSO_GRE_CSUM
= 1 << 7,
372 SKB_GSO_IPIP
= 1 << 8,
374 SKB_GSO_SIT
= 1 << 9,
376 SKB_GSO_UDP_TUNNEL
= 1 << 10,
378 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
380 SKB_GSO_TUNNEL_REMCSUM
= 1 << 12,
383 #if BITS_PER_LONG > 32
384 #define NET_SKBUFF_DATA_USES_OFFSET 1
387 #ifdef NET_SKBUFF_DATA_USES_OFFSET
388 typedef unsigned int sk_buff_data_t
;
390 typedef unsigned char *sk_buff_data_t
;
394 * struct skb_mstamp - multi resolution time stamps
395 * @stamp_us: timestamp in us resolution
396 * @stamp_jiffies: timestamp in jiffies
409 * skb_mstamp_get - get current timestamp
410 * @cl: place to store timestamps
412 static inline void skb_mstamp_get(struct skb_mstamp
*cl
)
414 u64 val
= local_clock();
416 do_div(val
, NSEC_PER_USEC
);
417 cl
->stamp_us
= (u32
)val
;
418 cl
->stamp_jiffies
= (u32
)jiffies
;
422 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
423 * @t1: pointer to newest sample
424 * @t0: pointer to oldest sample
426 static inline u32
skb_mstamp_us_delta(const struct skb_mstamp
*t1
,
427 const struct skb_mstamp
*t0
)
429 s32 delta_us
= t1
->stamp_us
- t0
->stamp_us
;
430 u32 delta_jiffies
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
432 /* If delta_us is negative, this might be because interval is too big,
433 * or local_clock() drift is too big : fallback using jiffies.
436 delta_jiffies
>= (INT_MAX
/ (USEC_PER_SEC
/ HZ
)))
438 delta_us
= jiffies_to_usecs(delta_jiffies
);
445 * struct sk_buff - socket buffer
446 * @next: Next buffer in list
447 * @prev: Previous buffer in list
448 * @tstamp: Time we arrived/left
449 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
450 * @sk: Socket we are owned by
451 * @dev: Device we arrived on/are leaving by
452 * @cb: Control buffer. Free for use by every layer. Put private vars here
453 * @_skb_refdst: destination entry (with norefcount bit)
454 * @sp: the security path, used for xfrm
455 * @len: Length of actual data
456 * @data_len: Data length
457 * @mac_len: Length of link layer header
458 * @hdr_len: writable header length of cloned skb
459 * @csum: Checksum (must include start/offset pair)
460 * @csum_start: Offset from skb->head where checksumming should start
461 * @csum_offset: Offset from csum_start where checksum should be stored
462 * @priority: Packet queueing priority
463 * @ignore_df: allow local fragmentation
464 * @cloned: Head may be cloned (check refcnt to be sure)
465 * @ip_summed: Driver fed us an IP checksum
466 * @nohdr: Payload reference only, must not modify header
467 * @nfctinfo: Relationship of this skb to the connection
468 * @pkt_type: Packet class
469 * @fclone: skbuff clone status
470 * @ipvs_property: skbuff is owned by ipvs
471 * @peeked: this packet has been seen already, so stats have been
472 * done for it, don't do them again
473 * @nf_trace: netfilter packet trace flag
474 * @protocol: Packet protocol from driver
475 * @destructor: Destruct function
476 * @nfct: Associated connection, if any
477 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
478 * @skb_iif: ifindex of device we arrived on
479 * @tc_index: Traffic control index
480 * @tc_verd: traffic control verdict
481 * @hash: the packet hash
482 * @queue_mapping: Queue mapping for multiqueue devices
483 * @xmit_more: More SKBs are pending for this queue
484 * @ndisc_nodetype: router type (from link layer)
485 * @ooo_okay: allow the mapping of a socket to a queue to be changed
486 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
488 * @sw_hash: indicates hash was computed in software stack
489 * @wifi_acked_valid: wifi_acked was set
490 * @wifi_acked: whether frame was acked on wifi or not
491 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
492 * @napi_id: id of the NAPI struct this skb came from
493 * @secmark: security marking
494 * @mark: Generic packet mark
495 * @vlan_proto: vlan encapsulation protocol
496 * @vlan_tci: vlan tag control information
497 * @inner_protocol: Protocol (encapsulation)
498 * @inner_transport_header: Inner transport layer header (encapsulation)
499 * @inner_network_header: Network layer header (encapsulation)
500 * @inner_mac_header: Link layer header (encapsulation)
501 * @transport_header: Transport layer header
502 * @network_header: Network layer header
503 * @mac_header: Link layer header
504 * @tail: Tail pointer
506 * @head: Head of buffer
507 * @data: Data head pointer
508 * @truesize: Buffer size
509 * @users: User count - see {datagram,tcp}.c
515 /* These two members must be first. */
516 struct sk_buff
*next
;
517 struct sk_buff
*prev
;
521 struct skb_mstamp skb_mstamp
;
524 struct rb_node rbnode
; /* used in netem & tcp stack */
527 struct net_device
*dev
;
530 * This is the control buffer. It is free to use for every
531 * layer. Please put your private variables there. If you
532 * want to keep them across layers you have to do a skb_clone()
533 * first. This is owned by whoever has the skb queued ATM.
535 char cb
[48] __aligned(8);
537 unsigned long _skb_refdst
;
538 void (*destructor
)(struct sk_buff
*skb
);
542 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
543 struct nf_conntrack
*nfct
;
545 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
546 struct nf_bridge_info
*nf_bridge
;
553 /* Following fields are _not_ copied in __copy_skb_header()
554 * Note that queue_mapping is here mostly to fill a hole.
556 kmemcheck_bitfield_begin(flags1
);
565 kmemcheck_bitfield_end(flags1
);
567 /* fields enclosed in headers_start/headers_end are copied
568 * using a single memcpy() in __copy_skb_header()
571 __u32 headers_start
[0];
574 /* if you move pkt_type around you also must adapt those constants */
575 #ifdef __BIG_ENDIAN_BITFIELD
576 #define PKT_TYPE_MAX (7 << 5)
578 #define PKT_TYPE_MAX 7
580 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
582 __u8 __pkt_type_offset
[0];
593 __u8 wifi_acked_valid
:1;
597 /* Indicates the inner headers are valid in the skbuff. */
598 __u8 encapsulation
:1;
599 __u8 encap_hdr_csum
:1;
601 __u8 csum_complete_sw
:1;
605 #ifdef CONFIG_IPV6_NDISC_NODETYPE
606 __u8 ndisc_nodetype
:2;
608 __u8 ipvs_property
:1;
609 __u8 inner_protocol_type
:1;
610 __u8 remcsum_offload
:1;
611 /* 3 or 5 bit hole */
613 #ifdef CONFIG_NET_SCHED
614 __u16 tc_index
; /* traffic control index */
615 #ifdef CONFIG_NET_CLS_ACT
616 __u16 tc_verd
; /* traffic control verdict */
632 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
634 unsigned int napi_id
;
635 unsigned int sender_cpu
;
638 #ifdef CONFIG_NETWORK_SECMARK
643 __u32 reserved_tailroom
;
647 __be16 inner_protocol
;
651 __u16 inner_transport_header
;
652 __u16 inner_network_header
;
653 __u16 inner_mac_header
;
656 __u16 transport_header
;
657 __u16 network_header
;
661 __u32 headers_end
[0];
664 /* These elements must be at the end, see alloc_skb() for details. */
669 unsigned int truesize
;
675 * Handling routines are only of interest to the kernel
677 #include <linux/slab.h>
680 #define SKB_ALLOC_FCLONE 0x01
681 #define SKB_ALLOC_RX 0x02
682 #define SKB_ALLOC_NAPI 0x04
684 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
685 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
687 return unlikely(skb
->pfmemalloc
);
691 * skb might have a dst pointer attached, refcounted or not.
692 * _skb_refdst low order bit is set if refcount was _not_ taken
694 #define SKB_DST_NOREF 1UL
695 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
698 * skb_dst - returns skb dst_entry
701 * Returns skb dst_entry, regardless of reference taken or not.
703 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
705 /* If refdst was not refcounted, check we still are in a
706 * rcu_read_lock section
708 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
709 !rcu_read_lock_held() &&
710 !rcu_read_lock_bh_held());
711 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
715 * skb_dst_set - sets skb dst
719 * Sets skb dst, assuming a reference was taken on dst and should
720 * be released by skb_dst_drop()
722 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
724 skb
->_skb_refdst
= (unsigned long)dst
;
728 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
732 * Sets skb dst, assuming a reference was not taken on dst.
733 * If dst entry is cached, we do not take reference and dst_release
734 * will be avoided by refdst_drop. If dst entry is not cached, we take
735 * reference, so that last dst_release can destroy the dst immediately.
737 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
739 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
740 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
744 * skb_dst_is_noref - Test if skb dst isn't refcounted
747 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
749 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
752 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
754 return (struct rtable
*)skb_dst(skb
);
757 void kfree_skb(struct sk_buff
*skb
);
758 void kfree_skb_list(struct sk_buff
*segs
);
759 void skb_tx_error(struct sk_buff
*skb
);
760 void consume_skb(struct sk_buff
*skb
);
761 void __kfree_skb(struct sk_buff
*skb
);
762 extern struct kmem_cache
*skbuff_head_cache
;
764 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
765 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
766 bool *fragstolen
, int *delta_truesize
);
768 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
770 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
771 static inline struct sk_buff
*alloc_skb(unsigned int size
,
774 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
777 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
778 unsigned long data_len
,
783 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
784 struct sk_buff_fclones
{
793 * skb_fclone_busy - check if fclone is busy
796 * Returns true is skb is a fast clone, and its clone is not freed.
797 * Some drivers call skb_orphan() in their ndo_start_xmit(),
798 * so we also check that this didnt happen.
800 static inline bool skb_fclone_busy(const struct sock
*sk
,
801 const struct sk_buff
*skb
)
803 const struct sk_buff_fclones
*fclones
;
805 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
807 return skb
->fclone
== SKB_FCLONE_ORIG
&&
808 atomic_read(&fclones
->fclone_ref
) > 1 &&
809 fclones
->skb2
.sk
== sk
;
812 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
815 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
818 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
819 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
821 return __alloc_skb_head(priority
, -1);
824 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
825 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
826 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
827 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
828 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
829 gfp_t gfp_mask
, bool fclone
);
830 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
833 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
836 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
837 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
838 unsigned int headroom
);
839 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
840 int newtailroom
, gfp_t priority
);
841 int skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
842 int offset
, int len
);
843 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
,
845 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
846 int skb_pad(struct sk_buff
*skb
, int pad
);
847 #define dev_kfree_skb(a) consume_skb(a)
849 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
850 int getfrag(void *from
, char *to
, int offset
,
851 int len
, int odd
, struct sk_buff
*skb
),
852 void *from
, int length
);
854 struct skb_seq_state
{
858 __u32 stepped_offset
;
859 struct sk_buff
*root_skb
;
860 struct sk_buff
*cur_skb
;
864 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
865 unsigned int to
, struct skb_seq_state
*st
);
866 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
867 struct skb_seq_state
*st
);
868 void skb_abort_seq_read(struct skb_seq_state
*st
);
870 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
871 unsigned int to
, struct ts_config
*config
);
874 * Packet hash types specify the type of hash in skb_set_hash.
876 * Hash types refer to the protocol layer addresses which are used to
877 * construct a packet's hash. The hashes are used to differentiate or identify
878 * flows of the protocol layer for the hash type. Hash types are either
879 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
881 * Properties of hashes:
883 * 1) Two packets in different flows have different hash values
884 * 2) Two packets in the same flow should have the same hash value
886 * A hash at a higher layer is considered to be more specific. A driver should
887 * set the most specific hash possible.
889 * A driver cannot indicate a more specific hash than the layer at which a hash
890 * was computed. For instance an L3 hash cannot be set as an L4 hash.
892 * A driver may indicate a hash level which is less specific than the
893 * actual layer the hash was computed on. For instance, a hash computed
894 * at L4 may be considered an L3 hash. This should only be done if the
895 * driver can't unambiguously determine that the HW computed the hash at
896 * the higher layer. Note that the "should" in the second property above
899 enum pkt_hash_types
{
900 PKT_HASH_TYPE_NONE
, /* Undefined type */
901 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
902 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
903 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
907 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
909 skb
->l4_hash
= (type
== PKT_HASH_TYPE_L4
);
914 void __skb_get_hash(struct sk_buff
*skb
);
915 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
917 if (!skb
->l4_hash
&& !skb
->sw_hash
)
923 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
928 static inline void skb_clear_hash(struct sk_buff
*skb
)
935 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
941 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
943 to
->hash
= from
->hash
;
944 to
->sw_hash
= from
->sw_hash
;
945 to
->l4_hash
= from
->l4_hash
;
948 #ifdef NET_SKBUFF_DATA_USES_OFFSET
949 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
951 return skb
->head
+ skb
->end
;
954 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
959 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
964 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
966 return skb
->end
- skb
->head
;
971 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
973 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
975 return &skb_shinfo(skb
)->hwtstamps
;
979 * skb_queue_empty - check if a queue is empty
982 * Returns true if the queue is empty, false otherwise.
984 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
986 return list
->next
== (const struct sk_buff
*) list
;
990 * skb_queue_is_last - check if skb is the last entry in the queue
994 * Returns true if @skb is the last buffer on the list.
996 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
997 const struct sk_buff
*skb
)
999 return skb
->next
== (const struct sk_buff
*) list
;
1003 * skb_queue_is_first - check if skb is the first entry in the queue
1007 * Returns true if @skb is the first buffer on the list.
1009 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1010 const struct sk_buff
*skb
)
1012 return skb
->prev
== (const struct sk_buff
*) list
;
1016 * skb_queue_next - return the next packet in the queue
1018 * @skb: current buffer
1020 * Return the next packet in @list after @skb. It is only valid to
1021 * call this if skb_queue_is_last() evaluates to false.
1023 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1024 const struct sk_buff
*skb
)
1026 /* This BUG_ON may seem severe, but if we just return then we
1027 * are going to dereference garbage.
1029 BUG_ON(skb_queue_is_last(list
, skb
));
1034 * skb_queue_prev - return the prev packet in the queue
1036 * @skb: current buffer
1038 * Return the prev packet in @list before @skb. It is only valid to
1039 * call this if skb_queue_is_first() evaluates to false.
1041 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1042 const struct sk_buff
*skb
)
1044 /* This BUG_ON may seem severe, but if we just return then we
1045 * are going to dereference garbage.
1047 BUG_ON(skb_queue_is_first(list
, skb
));
1052 * skb_get - reference buffer
1053 * @skb: buffer to reference
1055 * Makes another reference to a socket buffer and returns a pointer
1058 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1060 atomic_inc(&skb
->users
);
1065 * If users == 1, we are the only owner and are can avoid redundant
1070 * skb_cloned - is the buffer a clone
1071 * @skb: buffer to check
1073 * Returns true if the buffer was generated with skb_clone() and is
1074 * one of multiple shared copies of the buffer. Cloned buffers are
1075 * shared data so must not be written to under normal circumstances.
1077 static inline int skb_cloned(const struct sk_buff
*skb
)
1079 return skb
->cloned
&&
1080 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1083 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1085 might_sleep_if(pri
& __GFP_WAIT
);
1087 if (skb_cloned(skb
))
1088 return pskb_expand_head(skb
, 0, 0, pri
);
1094 * skb_header_cloned - is the header a clone
1095 * @skb: buffer to check
1097 * Returns true if modifying the header part of the buffer requires
1098 * the data to be copied.
1100 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1107 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1108 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1109 return dataref
!= 1;
1113 * skb_header_release - release reference to header
1114 * @skb: buffer to operate on
1116 * Drop a reference to the header part of the buffer. This is done
1117 * by acquiring a payload reference. You must not read from the header
1118 * part of skb->data after this.
1119 * Note : Check if you can use __skb_header_release() instead.
1121 static inline void skb_header_release(struct sk_buff
*skb
)
1125 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1129 * __skb_header_release - release reference to header
1130 * @skb: buffer to operate on
1132 * Variant of skb_header_release() assuming skb is private to caller.
1133 * We can avoid one atomic operation.
1135 static inline void __skb_header_release(struct sk_buff
*skb
)
1138 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1143 * skb_shared - is the buffer shared
1144 * @skb: buffer to check
1146 * Returns true if more than one person has a reference to this
1149 static inline int skb_shared(const struct sk_buff
*skb
)
1151 return atomic_read(&skb
->users
) != 1;
1155 * skb_share_check - check if buffer is shared and if so clone it
1156 * @skb: buffer to check
1157 * @pri: priority for memory allocation
1159 * If the buffer is shared the buffer is cloned and the old copy
1160 * drops a reference. A new clone with a single reference is returned.
1161 * If the buffer is not shared the original buffer is returned. When
1162 * being called from interrupt status or with spinlocks held pri must
1165 * NULL is returned on a memory allocation failure.
1167 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1169 might_sleep_if(pri
& __GFP_WAIT
);
1170 if (skb_shared(skb
)) {
1171 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1183 * Copy shared buffers into a new sk_buff. We effectively do COW on
1184 * packets to handle cases where we have a local reader and forward
1185 * and a couple of other messy ones. The normal one is tcpdumping
1186 * a packet thats being forwarded.
1190 * skb_unshare - make a copy of a shared buffer
1191 * @skb: buffer to check
1192 * @pri: priority for memory allocation
1194 * If the socket buffer is a clone then this function creates a new
1195 * copy of the data, drops a reference count on the old copy and returns
1196 * the new copy with the reference count at 1. If the buffer is not a clone
1197 * the original buffer is returned. When called with a spinlock held or
1198 * from interrupt state @pri must be %GFP_ATOMIC
1200 * %NULL is returned on a memory allocation failure.
1202 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1205 might_sleep_if(pri
& __GFP_WAIT
);
1206 if (skb_cloned(skb
)) {
1207 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1209 /* Free our shared copy */
1220 * skb_peek - peek at the head of an &sk_buff_head
1221 * @list_: list to peek at
1223 * Peek an &sk_buff. Unlike most other operations you _MUST_
1224 * be careful with this one. A peek leaves the buffer on the
1225 * list and someone else may run off with it. You must hold
1226 * the appropriate locks or have a private queue to do this.
1228 * Returns %NULL for an empty list or a pointer to the head element.
1229 * The reference count is not incremented and the reference is therefore
1230 * volatile. Use with caution.
1232 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1234 struct sk_buff
*skb
= list_
->next
;
1236 if (skb
== (struct sk_buff
*)list_
)
1242 * skb_peek_next - peek skb following the given one from a queue
1243 * @skb: skb to start from
1244 * @list_: list to peek at
1246 * Returns %NULL when the end of the list is met or a pointer to the
1247 * next element. The reference count is not incremented and the
1248 * reference is therefore volatile. Use with caution.
1250 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1251 const struct sk_buff_head
*list_
)
1253 struct sk_buff
*next
= skb
->next
;
1255 if (next
== (struct sk_buff
*)list_
)
1261 * skb_peek_tail - peek at the tail of an &sk_buff_head
1262 * @list_: list to peek at
1264 * Peek an &sk_buff. Unlike most other operations you _MUST_
1265 * be careful with this one. A peek leaves the buffer on the
1266 * list and someone else may run off with it. You must hold
1267 * the appropriate locks or have a private queue to do this.
1269 * Returns %NULL for an empty list or a pointer to the tail element.
1270 * The reference count is not incremented and the reference is therefore
1271 * volatile. Use with caution.
1273 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1275 struct sk_buff
*skb
= list_
->prev
;
1277 if (skb
== (struct sk_buff
*)list_
)
1284 * skb_queue_len - get queue length
1285 * @list_: list to measure
1287 * Return the length of an &sk_buff queue.
1289 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1295 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1296 * @list: queue to initialize
1298 * This initializes only the list and queue length aspects of
1299 * an sk_buff_head object. This allows to initialize the list
1300 * aspects of an sk_buff_head without reinitializing things like
1301 * the spinlock. It can also be used for on-stack sk_buff_head
1302 * objects where the spinlock is known to not be used.
1304 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1306 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1311 * This function creates a split out lock class for each invocation;
1312 * this is needed for now since a whole lot of users of the skb-queue
1313 * infrastructure in drivers have different locking usage (in hardirq)
1314 * than the networking core (in softirq only). In the long run either the
1315 * network layer or drivers should need annotation to consolidate the
1316 * main types of usage into 3 classes.
1318 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1320 spin_lock_init(&list
->lock
);
1321 __skb_queue_head_init(list
);
1324 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1325 struct lock_class_key
*class)
1327 skb_queue_head_init(list
);
1328 lockdep_set_class(&list
->lock
, class);
1332 * Insert an sk_buff on a list.
1334 * The "__skb_xxxx()" functions are the non-atomic ones that
1335 * can only be called with interrupts disabled.
1337 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1338 struct sk_buff_head
*list
);
1339 static inline void __skb_insert(struct sk_buff
*newsk
,
1340 struct sk_buff
*prev
, struct sk_buff
*next
,
1341 struct sk_buff_head
*list
)
1345 next
->prev
= prev
->next
= newsk
;
1349 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1350 struct sk_buff
*prev
,
1351 struct sk_buff
*next
)
1353 struct sk_buff
*first
= list
->next
;
1354 struct sk_buff
*last
= list
->prev
;
1364 * skb_queue_splice - join two skb lists, this is designed for stacks
1365 * @list: the new list to add
1366 * @head: the place to add it in the first list
1368 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1369 struct sk_buff_head
*head
)
1371 if (!skb_queue_empty(list
)) {
1372 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1373 head
->qlen
+= list
->qlen
;
1378 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1379 * @list: the new list to add
1380 * @head: the place to add it in the first list
1382 * The list at @list is reinitialised
1384 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1385 struct sk_buff_head
*head
)
1387 if (!skb_queue_empty(list
)) {
1388 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1389 head
->qlen
+= list
->qlen
;
1390 __skb_queue_head_init(list
);
1395 * skb_queue_splice_tail - join two skb lists, each list being a queue
1396 * @list: the new list to add
1397 * @head: the place to add it in the first list
1399 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1400 struct sk_buff_head
*head
)
1402 if (!skb_queue_empty(list
)) {
1403 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1404 head
->qlen
+= list
->qlen
;
1409 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1410 * @list: the new list to add
1411 * @head: the place to add it in the first list
1413 * Each of the lists is a queue.
1414 * The list at @list is reinitialised
1416 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1417 struct sk_buff_head
*head
)
1419 if (!skb_queue_empty(list
)) {
1420 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1421 head
->qlen
+= list
->qlen
;
1422 __skb_queue_head_init(list
);
1427 * __skb_queue_after - queue a buffer at the list head
1428 * @list: list to use
1429 * @prev: place after this buffer
1430 * @newsk: buffer to queue
1432 * Queue a buffer int the middle of a list. This function takes no locks
1433 * and you must therefore hold required locks before calling it.
1435 * A buffer cannot be placed on two lists at the same time.
1437 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1438 struct sk_buff
*prev
,
1439 struct sk_buff
*newsk
)
1441 __skb_insert(newsk
, prev
, prev
->next
, list
);
1444 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1445 struct sk_buff_head
*list
);
1447 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1448 struct sk_buff
*next
,
1449 struct sk_buff
*newsk
)
1451 __skb_insert(newsk
, next
->prev
, next
, list
);
1455 * __skb_queue_head - queue a buffer at the list head
1456 * @list: list to use
1457 * @newsk: buffer to queue
1459 * Queue a buffer at the start of a list. This function takes no locks
1460 * and you must therefore hold required locks before calling it.
1462 * A buffer cannot be placed on two lists at the same time.
1464 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1465 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1466 struct sk_buff
*newsk
)
1468 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1472 * __skb_queue_tail - queue a buffer at the list tail
1473 * @list: list to use
1474 * @newsk: buffer to queue
1476 * Queue a buffer at the end of a list. This function takes no locks
1477 * and you must therefore hold required locks before calling it.
1479 * A buffer cannot be placed on two lists at the same time.
1481 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1482 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1483 struct sk_buff
*newsk
)
1485 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1489 * remove sk_buff from list. _Must_ be called atomically, and with
1492 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1493 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1495 struct sk_buff
*next
, *prev
;
1500 skb
->next
= skb
->prev
= NULL
;
1506 * __skb_dequeue - remove from the head of the queue
1507 * @list: list to dequeue from
1509 * Remove the head of the list. This function does not take any locks
1510 * so must be used with appropriate locks held only. The head item is
1511 * returned or %NULL if the list is empty.
1513 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1514 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1516 struct sk_buff
*skb
= skb_peek(list
);
1518 __skb_unlink(skb
, list
);
1523 * __skb_dequeue_tail - remove from the tail of the queue
1524 * @list: list to dequeue from
1526 * Remove the tail of the list. This function does not take any locks
1527 * so must be used with appropriate locks held only. The tail item is
1528 * returned or %NULL if the list is empty.
1530 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1531 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1533 struct sk_buff
*skb
= skb_peek_tail(list
);
1535 __skb_unlink(skb
, list
);
1540 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1542 return skb
->data_len
;
1545 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1547 return skb
->len
- skb
->data_len
;
1550 static inline int skb_pagelen(const struct sk_buff
*skb
)
1554 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1555 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1556 return len
+ skb_headlen(skb
);
1560 * __skb_fill_page_desc - initialise a paged fragment in an skb
1561 * @skb: buffer containing fragment to be initialised
1562 * @i: paged fragment index to initialise
1563 * @page: the page to use for this fragment
1564 * @off: the offset to the data with @page
1565 * @size: the length of the data
1567 * Initialises the @i'th fragment of @skb to point to &size bytes at
1568 * offset @off within @page.
1570 * Does not take any additional reference on the fragment.
1572 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1573 struct page
*page
, int off
, int size
)
1575 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1578 * Propagate page->pfmemalloc to the skb if we can. The problem is
1579 * that not all callers have unique ownership of the page. If
1580 * pfmemalloc is set, we check the mapping as a mapping implies
1581 * page->index is set (index and pfmemalloc share space).
1582 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1583 * do not lose pfmemalloc information as the pages would not be
1584 * allocated using __GFP_MEMALLOC.
1586 frag
->page
.p
= page
;
1587 frag
->page_offset
= off
;
1588 skb_frag_size_set(frag
, size
);
1590 page
= compound_head(page
);
1591 if (page
->pfmemalloc
&& !page
->mapping
)
1592 skb
->pfmemalloc
= true;
1596 * skb_fill_page_desc - initialise a paged fragment in an skb
1597 * @skb: buffer containing fragment to be initialised
1598 * @i: paged fragment index to initialise
1599 * @page: the page to use for this fragment
1600 * @off: the offset to the data with @page
1601 * @size: the length of the data
1603 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1604 * @skb to point to @size bytes at offset @off within @page. In
1605 * addition updates @skb such that @i is the last fragment.
1607 * Does not take any additional reference on the fragment.
1609 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1610 struct page
*page
, int off
, int size
)
1612 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1613 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1616 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1617 int size
, unsigned int truesize
);
1619 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1620 unsigned int truesize
);
1622 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1623 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1624 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1626 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1627 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1629 return skb
->head
+ skb
->tail
;
1632 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1634 skb
->tail
= skb
->data
- skb
->head
;
1637 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1639 skb_reset_tail_pointer(skb
);
1640 skb
->tail
+= offset
;
1643 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1644 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1649 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1651 skb
->tail
= skb
->data
;
1654 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1656 skb
->tail
= skb
->data
+ offset
;
1659 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1662 * Add data to an sk_buff
1664 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1665 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1666 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1668 unsigned char *tmp
= skb_tail_pointer(skb
);
1669 SKB_LINEAR_ASSERT(skb
);
1675 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1676 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1683 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1684 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1687 BUG_ON(skb
->len
< skb
->data_len
);
1688 return skb
->data
+= len
;
1691 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1693 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1696 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1698 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1700 if (len
> skb_headlen(skb
) &&
1701 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1704 return skb
->data
+= len
;
1707 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1709 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1712 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1714 if (likely(len
<= skb_headlen(skb
)))
1716 if (unlikely(len
> skb
->len
))
1718 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1722 * skb_headroom - bytes at buffer head
1723 * @skb: buffer to check
1725 * Return the number of bytes of free space at the head of an &sk_buff.
1727 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1729 return skb
->data
- skb
->head
;
1733 * skb_tailroom - bytes at buffer end
1734 * @skb: buffer to check
1736 * Return the number of bytes of free space at the tail of an sk_buff
1738 static inline int skb_tailroom(const struct sk_buff
*skb
)
1740 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1744 * skb_availroom - bytes at buffer end
1745 * @skb: buffer to check
1747 * Return the number of bytes of free space at the tail of an sk_buff
1748 * allocated by sk_stream_alloc()
1750 static inline int skb_availroom(const struct sk_buff
*skb
)
1752 if (skb_is_nonlinear(skb
))
1755 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1759 * skb_reserve - adjust headroom
1760 * @skb: buffer to alter
1761 * @len: bytes to move
1763 * Increase the headroom of an empty &sk_buff by reducing the tail
1764 * room. This is only allowed for an empty buffer.
1766 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1772 #define ENCAP_TYPE_ETHER 0
1773 #define ENCAP_TYPE_IPPROTO 1
1775 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
1778 skb
->inner_protocol
= protocol
;
1779 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
1782 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
1785 skb
->inner_ipproto
= ipproto
;
1786 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
1789 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1791 skb
->inner_mac_header
= skb
->mac_header
;
1792 skb
->inner_network_header
= skb
->network_header
;
1793 skb
->inner_transport_header
= skb
->transport_header
;
1796 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1798 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1801 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1804 return skb
->head
+ skb
->inner_transport_header
;
1807 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1809 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1812 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1815 skb_reset_inner_transport_header(skb
);
1816 skb
->inner_transport_header
+= offset
;
1819 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1821 return skb
->head
+ skb
->inner_network_header
;
1824 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1826 skb
->inner_network_header
= skb
->data
- skb
->head
;
1829 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1832 skb_reset_inner_network_header(skb
);
1833 skb
->inner_network_header
+= offset
;
1836 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
1838 return skb
->head
+ skb
->inner_mac_header
;
1841 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
1843 skb
->inner_mac_header
= skb
->data
- skb
->head
;
1846 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
1849 skb_reset_inner_mac_header(skb
);
1850 skb
->inner_mac_header
+= offset
;
1852 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1854 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
1857 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1859 return skb
->head
+ skb
->transport_header
;
1862 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1864 skb
->transport_header
= skb
->data
- skb
->head
;
1867 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1870 skb_reset_transport_header(skb
);
1871 skb
->transport_header
+= offset
;
1874 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1876 return skb
->head
+ skb
->network_header
;
1879 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1881 skb
->network_header
= skb
->data
- skb
->head
;
1884 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1886 skb_reset_network_header(skb
);
1887 skb
->network_header
+= offset
;
1890 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1892 return skb
->head
+ skb
->mac_header
;
1895 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1897 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
1900 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1902 skb
->mac_header
= skb
->data
- skb
->head
;
1905 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1907 skb_reset_mac_header(skb
);
1908 skb
->mac_header
+= offset
;
1911 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
1913 skb
->mac_header
= skb
->network_header
;
1916 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
1917 const int offset_hint
)
1919 struct flow_keys keys
;
1921 if (skb_transport_header_was_set(skb
))
1923 else if (skb_flow_dissect(skb
, &keys
))
1924 skb_set_transport_header(skb
, keys
.thoff
);
1926 skb_set_transport_header(skb
, offset_hint
);
1929 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1931 if (skb_mac_header_was_set(skb
)) {
1932 const unsigned char *old_mac
= skb_mac_header(skb
);
1934 skb_set_mac_header(skb
, -skb
->mac_len
);
1935 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1939 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1941 return skb
->csum_start
- skb_headroom(skb
);
1944 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1946 return skb_transport_header(skb
) - skb
->data
;
1949 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1951 return skb
->transport_header
- skb
->network_header
;
1954 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1956 return skb
->inner_transport_header
- skb
->inner_network_header
;
1959 static inline int skb_network_offset(const struct sk_buff
*skb
)
1961 return skb_network_header(skb
) - skb
->data
;
1964 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1966 return skb_inner_network_header(skb
) - skb
->data
;
1969 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1971 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1975 * CPUs often take a performance hit when accessing unaligned memory
1976 * locations. The actual performance hit varies, it can be small if the
1977 * hardware handles it or large if we have to take an exception and fix it
1980 * Since an ethernet header is 14 bytes network drivers often end up with
1981 * the IP header at an unaligned offset. The IP header can be aligned by
1982 * shifting the start of the packet by 2 bytes. Drivers should do this
1985 * skb_reserve(skb, NET_IP_ALIGN);
1987 * The downside to this alignment of the IP header is that the DMA is now
1988 * unaligned. On some architectures the cost of an unaligned DMA is high
1989 * and this cost outweighs the gains made by aligning the IP header.
1991 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1994 #ifndef NET_IP_ALIGN
1995 #define NET_IP_ALIGN 2
1999 * The networking layer reserves some headroom in skb data (via
2000 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2001 * the header has to grow. In the default case, if the header has to grow
2002 * 32 bytes or less we avoid the reallocation.
2004 * Unfortunately this headroom changes the DMA alignment of the resulting
2005 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2006 * on some architectures. An architecture can override this value,
2007 * perhaps setting it to a cacheline in size (since that will maintain
2008 * cacheline alignment of the DMA). It must be a power of 2.
2010 * Various parts of the networking layer expect at least 32 bytes of
2011 * headroom, you should not reduce this.
2013 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2014 * to reduce average number of cache lines per packet.
2015 * get_rps_cpus() for example only access one 64 bytes aligned block :
2016 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2019 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2022 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2024 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2026 if (unlikely(skb_is_nonlinear(skb
))) {
2031 skb_set_tail_pointer(skb
, len
);
2034 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2036 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2039 return ___pskb_trim(skb
, len
);
2040 __skb_trim(skb
, len
);
2044 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2046 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2050 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2051 * @skb: buffer to alter
2054 * This is identical to pskb_trim except that the caller knows that
2055 * the skb is not cloned so we should never get an error due to out-
2058 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2060 int err
= pskb_trim(skb
, len
);
2065 * skb_orphan - orphan a buffer
2066 * @skb: buffer to orphan
2068 * If a buffer currently has an owner then we call the owner's
2069 * destructor function and make the @skb unowned. The buffer continues
2070 * to exist but is no longer charged to its former owner.
2072 static inline void skb_orphan(struct sk_buff
*skb
)
2074 if (skb
->destructor
) {
2075 skb
->destructor(skb
);
2076 skb
->destructor
= NULL
;
2084 * skb_orphan_frags - orphan the frags contained in a buffer
2085 * @skb: buffer to orphan frags from
2086 * @gfp_mask: allocation mask for replacement pages
2088 * For each frag in the SKB which needs a destructor (i.e. has an
2089 * owner) create a copy of that frag and release the original
2090 * page by calling the destructor.
2092 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2094 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
2096 return skb_copy_ubufs(skb
, gfp_mask
);
2100 * __skb_queue_purge - empty a list
2101 * @list: list to empty
2103 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2104 * the list and one reference dropped. This function does not take the
2105 * list lock and the caller must hold the relevant locks to use it.
2107 void skb_queue_purge(struct sk_buff_head
*list
);
2108 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2110 struct sk_buff
*skb
;
2111 while ((skb
= __skb_dequeue(list
)) != NULL
)
2115 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2116 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2117 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2119 void *netdev_alloc_frag(unsigned int fragsz
);
2121 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2125 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2126 * @dev: network device to receive on
2127 * @length: length to allocate
2129 * Allocate a new &sk_buff and assign it a usage count of one. The
2130 * buffer has unspecified headroom built in. Users should allocate
2131 * the headroom they think they need without accounting for the
2132 * built in space. The built in space is used for optimisations.
2134 * %NULL is returned if there is no free memory. Although this function
2135 * allocates memory it can be called from an interrupt.
2137 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2138 unsigned int length
)
2140 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2143 /* legacy helper around __netdev_alloc_skb() */
2144 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2147 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2150 /* legacy helper around netdev_alloc_skb() */
2151 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2153 return netdev_alloc_skb(NULL
, length
);
2157 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2158 unsigned int length
, gfp_t gfp
)
2160 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2162 if (NET_IP_ALIGN
&& skb
)
2163 skb_reserve(skb
, NET_IP_ALIGN
);
2167 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2168 unsigned int length
)
2170 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2173 void *napi_alloc_frag(unsigned int fragsz
);
2174 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2175 unsigned int length
, gfp_t gfp_mask
);
2176 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2177 unsigned int length
)
2179 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2183 * __dev_alloc_pages - allocate page for network Rx
2184 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2185 * @order: size of the allocation
2187 * Allocate a new page.
2189 * %NULL is returned if there is no free memory.
2191 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2194 /* This piece of code contains several assumptions.
2195 * 1. This is for device Rx, therefor a cold page is preferred.
2196 * 2. The expectation is the user wants a compound page.
2197 * 3. If requesting a order 0 page it will not be compound
2198 * due to the check to see if order has a value in prep_new_page
2199 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2200 * code in gfp_to_alloc_flags that should be enforcing this.
2202 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2204 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2207 static inline struct page
*dev_alloc_pages(unsigned int order
)
2209 return __dev_alloc_pages(GFP_ATOMIC
, order
);
2213 * __dev_alloc_page - allocate a page for network Rx
2214 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2216 * Allocate a new page.
2218 * %NULL is returned if there is no free memory.
2220 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2222 return __dev_alloc_pages(gfp_mask
, 0);
2225 static inline struct page
*dev_alloc_page(void)
2227 return __dev_alloc_page(GFP_ATOMIC
);
2231 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2232 * @page: The page that was allocated from skb_alloc_page
2233 * @skb: The skb that may need pfmemalloc set
2235 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2236 struct sk_buff
*skb
)
2238 if (page
&& page
->pfmemalloc
)
2239 skb
->pfmemalloc
= true;
2243 * skb_frag_page - retrieve the page referred to by a paged fragment
2244 * @frag: the paged fragment
2246 * Returns the &struct page associated with @frag.
2248 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2250 return frag
->page
.p
;
2254 * __skb_frag_ref - take an addition reference on a paged fragment.
2255 * @frag: the paged fragment
2257 * Takes an additional reference on the paged fragment @frag.
2259 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2261 get_page(skb_frag_page(frag
));
2265 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2267 * @f: the fragment offset.
2269 * Takes an additional reference on the @f'th paged fragment of @skb.
2271 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2273 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2277 * __skb_frag_unref - release a reference on a paged fragment.
2278 * @frag: the paged fragment
2280 * Releases a reference on the paged fragment @frag.
2282 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2284 put_page(skb_frag_page(frag
));
2288 * skb_frag_unref - release a reference on a paged fragment of an skb.
2290 * @f: the fragment offset
2292 * Releases a reference on the @f'th paged fragment of @skb.
2294 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2296 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2300 * skb_frag_address - gets the address of the data contained in a paged fragment
2301 * @frag: the paged fragment buffer
2303 * Returns the address of the data within @frag. The page must already
2306 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2308 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2312 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2313 * @frag: the paged fragment buffer
2315 * Returns the address of the data within @frag. Checks that the page
2316 * is mapped and returns %NULL otherwise.
2318 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2320 void *ptr
= page_address(skb_frag_page(frag
));
2324 return ptr
+ frag
->page_offset
;
2328 * __skb_frag_set_page - sets the page contained in a paged fragment
2329 * @frag: the paged fragment
2330 * @page: the page to set
2332 * Sets the fragment @frag to contain @page.
2334 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2336 frag
->page
.p
= page
;
2340 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2342 * @f: the fragment offset
2343 * @page: the page to set
2345 * Sets the @f'th fragment of @skb to contain @page.
2347 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2350 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2353 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2356 * skb_frag_dma_map - maps a paged fragment via the DMA API
2357 * @dev: the device to map the fragment to
2358 * @frag: the paged fragment to map
2359 * @offset: the offset within the fragment (starting at the
2360 * fragment's own offset)
2361 * @size: the number of bytes to map
2362 * @dir: the direction of the mapping (%PCI_DMA_*)
2364 * Maps the page associated with @frag to @device.
2366 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2367 const skb_frag_t
*frag
,
2368 size_t offset
, size_t size
,
2369 enum dma_data_direction dir
)
2371 return dma_map_page(dev
, skb_frag_page(frag
),
2372 frag
->page_offset
+ offset
, size
, dir
);
2375 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2378 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2382 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2385 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2390 * skb_clone_writable - is the header of a clone writable
2391 * @skb: buffer to check
2392 * @len: length up to which to write
2394 * Returns true if modifying the header part of the cloned buffer
2395 * does not requires the data to be copied.
2397 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2399 return !skb_header_cloned(skb
) &&
2400 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2403 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2408 if (headroom
> skb_headroom(skb
))
2409 delta
= headroom
- skb_headroom(skb
);
2411 if (delta
|| cloned
)
2412 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2418 * skb_cow - copy header of skb when it is required
2419 * @skb: buffer to cow
2420 * @headroom: needed headroom
2422 * If the skb passed lacks sufficient headroom or its data part
2423 * is shared, data is reallocated. If reallocation fails, an error
2424 * is returned and original skb is not changed.
2426 * The result is skb with writable area skb->head...skb->tail
2427 * and at least @headroom of space at head.
2429 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2431 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2435 * skb_cow_head - skb_cow but only making the head writable
2436 * @skb: buffer to cow
2437 * @headroom: needed headroom
2439 * This function is identical to skb_cow except that we replace the
2440 * skb_cloned check by skb_header_cloned. It should be used when
2441 * you only need to push on some header and do not need to modify
2444 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2446 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2450 * skb_padto - pad an skbuff up to a minimal size
2451 * @skb: buffer to pad
2452 * @len: minimal length
2454 * Pads up a buffer to ensure the trailing bytes exist and are
2455 * blanked. If the buffer already contains sufficient data it
2456 * is untouched. Otherwise it is extended. Returns zero on
2457 * success. The skb is freed on error.
2459 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2461 unsigned int size
= skb
->len
;
2462 if (likely(size
>= len
))
2464 return skb_pad(skb
, len
- size
);
2468 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2469 * @skb: buffer to pad
2470 * @len: minimal length
2472 * Pads up a buffer to ensure the trailing bytes exist and are
2473 * blanked. If the buffer already contains sufficient data it
2474 * is untouched. Otherwise it is extended. Returns zero on
2475 * success. The skb is freed on error.
2477 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2479 unsigned int size
= skb
->len
;
2481 if (unlikely(size
< len
)) {
2483 if (skb_pad(skb
, len
))
2485 __skb_put(skb
, len
);
2490 static inline int skb_add_data(struct sk_buff
*skb
,
2491 struct iov_iter
*from
, int copy
)
2493 const int off
= skb
->len
;
2495 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2497 if (csum_and_copy_from_iter(skb_put(skb
, copy
), copy
,
2498 &csum
, from
) == copy
) {
2499 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2502 } else if (copy_from_iter(skb_put(skb
, copy
), copy
, from
) == copy
)
2505 __skb_trim(skb
, off
);
2509 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2510 const struct page
*page
, int off
)
2513 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2515 return page
== skb_frag_page(frag
) &&
2516 off
== frag
->page_offset
+ skb_frag_size(frag
);
2521 static inline int __skb_linearize(struct sk_buff
*skb
)
2523 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2527 * skb_linearize - convert paged skb to linear one
2528 * @skb: buffer to linarize
2530 * If there is no free memory -ENOMEM is returned, otherwise zero
2531 * is returned and the old skb data released.
2533 static inline int skb_linearize(struct sk_buff
*skb
)
2535 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2539 * skb_has_shared_frag - can any frag be overwritten
2540 * @skb: buffer to test
2542 * Return true if the skb has at least one frag that might be modified
2543 * by an external entity (as in vmsplice()/sendfile())
2545 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2547 return skb_is_nonlinear(skb
) &&
2548 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2552 * skb_linearize_cow - make sure skb is linear and writable
2553 * @skb: buffer to process
2555 * If there is no free memory -ENOMEM is returned, otherwise zero
2556 * is returned and the old skb data released.
2558 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2560 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2561 __skb_linearize(skb
) : 0;
2565 * skb_postpull_rcsum - update checksum for received skb after pull
2566 * @skb: buffer to update
2567 * @start: start of data before pull
2568 * @len: length of data pulled
2570 * After doing a pull on a received packet, you need to call this to
2571 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2572 * CHECKSUM_NONE so that it can be recomputed from scratch.
2575 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2576 const void *start
, unsigned int len
)
2578 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2579 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2582 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2585 * pskb_trim_rcsum - trim received skb and update checksum
2586 * @skb: buffer to trim
2589 * This is exactly the same as pskb_trim except that it ensures the
2590 * checksum of received packets are still valid after the operation.
2593 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2595 if (likely(len
>= skb
->len
))
2597 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2598 skb
->ip_summed
= CHECKSUM_NONE
;
2599 return __pskb_trim(skb
, len
);
2602 #define skb_queue_walk(queue, skb) \
2603 for (skb = (queue)->next; \
2604 skb != (struct sk_buff *)(queue); \
2607 #define skb_queue_walk_safe(queue, skb, tmp) \
2608 for (skb = (queue)->next, tmp = skb->next; \
2609 skb != (struct sk_buff *)(queue); \
2610 skb = tmp, tmp = skb->next)
2612 #define skb_queue_walk_from(queue, skb) \
2613 for (; skb != (struct sk_buff *)(queue); \
2616 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2617 for (tmp = skb->next; \
2618 skb != (struct sk_buff *)(queue); \
2619 skb = tmp, tmp = skb->next)
2621 #define skb_queue_reverse_walk(queue, skb) \
2622 for (skb = (queue)->prev; \
2623 skb != (struct sk_buff *)(queue); \
2626 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2627 for (skb = (queue)->prev, tmp = skb->prev; \
2628 skb != (struct sk_buff *)(queue); \
2629 skb = tmp, tmp = skb->prev)
2631 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2632 for (tmp = skb->prev; \
2633 skb != (struct sk_buff *)(queue); \
2634 skb = tmp, tmp = skb->prev)
2636 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2638 return skb_shinfo(skb
)->frag_list
!= NULL
;
2641 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2643 skb_shinfo(skb
)->frag_list
= NULL
;
2646 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2648 frag
->next
= skb_shinfo(skb
)->frag_list
;
2649 skb_shinfo(skb
)->frag_list
= frag
;
2652 #define skb_walk_frags(skb, iter) \
2653 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2655 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2656 int *peeked
, int *off
, int *err
);
2657 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
2659 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2660 struct poll_table_struct
*wait
);
2661 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
2662 struct iov_iter
*to
, int size
);
2663 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
2664 struct msghdr
*msg
, int size
)
2666 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
2668 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
2669 struct msghdr
*msg
);
2670 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
2671 struct iov_iter
*from
, int len
);
2672 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
2673 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2674 void skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
);
2675 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
2676 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
2677 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
2678 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
2679 int len
, __wsum csum
);
2680 int skb_splice_bits(struct sk_buff
*skb
, unsigned int offset
,
2681 struct pipe_inode_info
*pipe
, unsigned int len
,
2682 unsigned int flags
);
2683 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2684 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
2685 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
2687 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
2688 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
2689 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
2690 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
2691 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
2692 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
2693 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
2694 int skb_vlan_pop(struct sk_buff
*skb
);
2695 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
2697 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
2699 return copy_from_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
2702 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
2704 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
2707 struct skb_checksum_ops
{
2708 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
2709 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
2712 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2713 __wsum csum
, const struct skb_checksum_ops
*ops
);
2714 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2717 static inline void *__skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2718 int len
, void *data
, int hlen
, void *buffer
)
2720 if (hlen
- offset
>= len
)
2721 return data
+ offset
;
2724 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2730 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2731 int len
, void *buffer
)
2733 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
2734 skb_headlen(skb
), buffer
);
2738 * skb_needs_linearize - check if we need to linearize a given skb
2739 * depending on the given device features.
2740 * @skb: socket buffer to check
2741 * @features: net device features
2743 * Returns true if either:
2744 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2745 * 2. skb is fragmented and the device does not support SG.
2747 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
2748 netdev_features_t features
)
2750 return skb_is_nonlinear(skb
) &&
2751 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
2752 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
2755 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2757 const unsigned int len
)
2759 memcpy(to
, skb
->data
, len
);
2762 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2763 const int offset
, void *to
,
2764 const unsigned int len
)
2766 memcpy(to
, skb
->data
+ offset
, len
);
2769 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2771 const unsigned int len
)
2773 memcpy(skb
->data
, from
, len
);
2776 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2779 const unsigned int len
)
2781 memcpy(skb
->data
+ offset
, from
, len
);
2784 void skb_init(void);
2786 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2792 * skb_get_timestamp - get timestamp from a skb
2793 * @skb: skb to get stamp from
2794 * @stamp: pointer to struct timeval to store stamp in
2796 * Timestamps are stored in the skb as offsets to a base timestamp.
2797 * This function converts the offset back to a struct timeval and stores
2800 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2801 struct timeval
*stamp
)
2803 *stamp
= ktime_to_timeval(skb
->tstamp
);
2806 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2807 struct timespec
*stamp
)
2809 *stamp
= ktime_to_timespec(skb
->tstamp
);
2812 static inline void __net_timestamp(struct sk_buff
*skb
)
2814 skb
->tstamp
= ktime_get_real();
2817 static inline ktime_t
net_timedelta(ktime_t t
)
2819 return ktime_sub(ktime_get_real(), t
);
2822 static inline ktime_t
net_invalid_timestamp(void)
2824 return ktime_set(0, 0);
2827 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
2829 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2831 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2832 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2834 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2836 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2840 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2845 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2848 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2850 * PHY drivers may accept clones of transmitted packets for
2851 * timestamping via their phy_driver.txtstamp method. These drivers
2852 * must call this function to return the skb back to the stack, with
2853 * or without a timestamp.
2855 * @skb: clone of the the original outgoing packet
2856 * @hwtstamps: hardware time stamps, may be NULL if not available
2859 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2860 struct skb_shared_hwtstamps
*hwtstamps
);
2862 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
2863 struct skb_shared_hwtstamps
*hwtstamps
,
2864 struct sock
*sk
, int tstype
);
2867 * skb_tstamp_tx - queue clone of skb with send time stamps
2868 * @orig_skb: the original outgoing packet
2869 * @hwtstamps: hardware time stamps, may be NULL if not available
2871 * If the skb has a socket associated, then this function clones the
2872 * skb (thus sharing the actual data and optional structures), stores
2873 * the optional hardware time stamping information (if non NULL) or
2874 * generates a software time stamp (otherwise), then queues the clone
2875 * to the error queue of the socket. Errors are silently ignored.
2877 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2878 struct skb_shared_hwtstamps
*hwtstamps
);
2880 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2882 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2883 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2884 skb_tstamp_tx(skb
, NULL
);
2888 * skb_tx_timestamp() - Driver hook for transmit timestamping
2890 * Ethernet MAC Drivers should call this function in their hard_xmit()
2891 * function immediately before giving the sk_buff to the MAC hardware.
2893 * Specifically, one should make absolutely sure that this function is
2894 * called before TX completion of this packet can trigger. Otherwise
2895 * the packet could potentially already be freed.
2897 * @skb: A socket buffer.
2899 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2901 skb_clone_tx_timestamp(skb
);
2902 sw_tx_timestamp(skb
);
2906 * skb_complete_wifi_ack - deliver skb with wifi status
2908 * @skb: the original outgoing packet
2909 * @acked: ack status
2912 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2914 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2915 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2917 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2919 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
2921 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
2922 skb_checksum_start_offset(skb
) >= 0));
2926 * skb_checksum_complete - Calculate checksum of an entire packet
2927 * @skb: packet to process
2929 * This function calculates the checksum over the entire packet plus
2930 * the value of skb->csum. The latter can be used to supply the
2931 * checksum of a pseudo header as used by TCP/UDP. It returns the
2934 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2935 * this function can be used to verify that checksum on received
2936 * packets. In that case the function should return zero if the
2937 * checksum is correct. In particular, this function will return zero
2938 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2939 * hardware has already verified the correctness of the checksum.
2941 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2943 return skb_csum_unnecessary(skb
) ?
2944 0 : __skb_checksum_complete(skb
);
2947 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
2949 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
2950 if (skb
->csum_level
== 0)
2951 skb
->ip_summed
= CHECKSUM_NONE
;
2957 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
2959 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
2960 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
2962 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
2963 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2964 skb
->csum_level
= 0;
2968 static inline void __skb_mark_checksum_bad(struct sk_buff
*skb
)
2970 /* Mark current checksum as bad (typically called from GRO
2971 * path). In the case that ip_summed is CHECKSUM_NONE
2972 * this must be the first checksum encountered in the packet.
2973 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
2974 * checksum after the last one validated. For UDP, a zero
2975 * checksum can not be marked as bad.
2978 if (skb
->ip_summed
== CHECKSUM_NONE
||
2979 skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
2983 /* Check if we need to perform checksum complete validation.
2985 * Returns true if checksum complete is needed, false otherwise
2986 * (either checksum is unnecessary or zero checksum is allowed).
2988 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
2992 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
2993 skb
->csum_valid
= 1;
2994 __skb_decr_checksum_unnecessary(skb
);
3001 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3004 #define CHECKSUM_BREAK 76
3006 /* Validate (init) checksum based on checksum complete.
3009 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3010 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3011 * checksum is stored in skb->csum for use in __skb_checksum_complete
3012 * non-zero: value of invalid checksum
3015 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3019 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3020 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3021 skb
->csum_valid
= 1;
3024 } else if (skb
->csum_bad
) {
3025 /* ip_summed == CHECKSUM_NONE in this case */
3031 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3034 csum
= __skb_checksum_complete(skb
);
3035 skb
->csum_valid
= !csum
;
3042 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3047 /* Perform checksum validate (init). Note that this is a macro since we only
3048 * want to calculate the pseudo header which is an input function if necessary.
3049 * First we try to validate without any computation (checksum unnecessary) and
3050 * then calculate based on checksum complete calling the function to compute
3054 * 0: checksum is validated or try to in skb_checksum_complete
3055 * non-zero: value of invalid checksum
3057 #define __skb_checksum_validate(skb, proto, complete, \
3058 zero_okay, check, compute_pseudo) \
3060 __sum16 __ret = 0; \
3061 skb->csum_valid = 0; \
3062 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3063 __ret = __skb_checksum_validate_complete(skb, \
3064 complete, compute_pseudo(skb, proto)); \
3068 #define skb_checksum_init(skb, proto, compute_pseudo) \
3069 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3071 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3072 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3074 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3075 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3077 #define skb_checksum_validate_zero_check(skb, proto, check, \
3079 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3081 #define skb_checksum_simple_validate(skb) \
3082 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3084 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3086 return (skb
->ip_summed
== CHECKSUM_NONE
&&
3087 skb
->csum_valid
&& !skb
->csum_bad
);
3090 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3091 __sum16 check
, __wsum pseudo
)
3093 skb
->csum
= ~pseudo
;
3094 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3097 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3099 if (__skb_checksum_convert_check(skb)) \
3100 __skb_checksum_convert(skb, check, \
3101 compute_pseudo(skb, proto)); \
3104 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3105 u16 start
, u16 offset
)
3107 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3108 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3109 skb
->csum_offset
= offset
- start
;
3112 /* Update skbuf and packet to reflect the remote checksum offload operation.
3113 * When called, ptr indicates the starting point for skb->csum when
3114 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3115 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3117 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3118 int start
, int offset
, bool nopartial
)
3123 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3127 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3128 __skb_checksum_complete(skb
);
3129 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3132 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3134 /* Adjust skb->csum since we changed the packet */
3135 skb
->csum
= csum_add(skb
->csum
, delta
);
3138 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3139 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3140 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3142 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3143 nf_conntrack_destroy(nfct
);
3145 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3148 atomic_inc(&nfct
->use
);
3151 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3152 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3154 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
3157 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3160 atomic_inc(&nf_bridge
->use
);
3162 #endif /* CONFIG_BRIDGE_NETFILTER */
3163 static inline void nf_reset(struct sk_buff
*skb
)
3165 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3166 nf_conntrack_put(skb
->nfct
);
3169 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3170 nf_bridge_put(skb
->nf_bridge
);
3171 skb
->nf_bridge
= NULL
;
3175 static inline void nf_reset_trace(struct sk_buff
*skb
)
3177 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3182 /* Note: This doesn't put any conntrack and bridge info in dst. */
3183 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3186 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3187 dst
->nfct
= src
->nfct
;
3188 nf_conntrack_get(src
->nfct
);
3190 dst
->nfctinfo
= src
->nfctinfo
;
3192 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3193 dst
->nf_bridge
= src
->nf_bridge
;
3194 nf_bridge_get(src
->nf_bridge
);
3196 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3198 dst
->nf_trace
= src
->nf_trace
;
3202 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3204 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3205 nf_conntrack_put(dst
->nfct
);
3207 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3208 nf_bridge_put(dst
->nf_bridge
);
3210 __nf_copy(dst
, src
, true);
3213 #ifdef CONFIG_NETWORK_SECMARK
3214 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3216 to
->secmark
= from
->secmark
;
3219 static inline void skb_init_secmark(struct sk_buff
*skb
)
3224 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3227 static inline void skb_init_secmark(struct sk_buff
*skb
)
3231 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3233 return !skb
->destructor
&&
3234 #if IS_ENABLED(CONFIG_XFRM)
3237 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3240 !skb
->_skb_refdst
&&
3241 !skb_has_frag_list(skb
);
3244 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3246 skb
->queue_mapping
= queue_mapping
;
3249 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3251 return skb
->queue_mapping
;
3254 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3256 to
->queue_mapping
= from
->queue_mapping
;
3259 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3261 skb
->queue_mapping
= rx_queue
+ 1;
3264 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3266 return skb
->queue_mapping
- 1;
3269 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3271 return skb
->queue_mapping
!= 0;
3274 u16
__skb_tx_hash(const struct net_device
*dev
, struct sk_buff
*skb
,
3275 unsigned int num_tx_queues
);
3277 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3286 /* Keeps track of mac header offset relative to skb->head.
3287 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3288 * For non-tunnel skb it points to skb_mac_header() and for
3289 * tunnel skb it points to outer mac header.
3290 * Keeps track of level of encapsulation of network headers.
3297 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3299 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3301 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3302 SKB_GSO_CB(inner_skb
)->mac_offset
;
3305 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3307 int new_headroom
, headroom
;
3310 headroom
= skb_headroom(skb
);
3311 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3315 new_headroom
= skb_headroom(skb
);
3316 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3320 /* Compute the checksum for a gso segment. First compute the checksum value
3321 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3322 * then add in skb->csum (checksum from csum_start to end of packet).
3323 * skb->csum and csum_start are then updated to reflect the checksum of the
3324 * resultant packet starting from the transport header-- the resultant checksum
3325 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3328 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3330 int plen
= SKB_GSO_CB(skb
)->csum_start
- skb_headroom(skb
) -
3331 skb_transport_offset(skb
);
3334 csum
= csum_fold(csum_partial(skb_transport_header(skb
),
3337 SKB_GSO_CB(skb
)->csum_start
-= plen
;
3342 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3344 return skb_shinfo(skb
)->gso_size
;
3347 /* Note: Should be called only if skb_is_gso(skb) is true */
3348 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3350 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3353 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3355 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3357 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3358 * wanted then gso_type will be set. */
3359 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3361 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3362 unlikely(shinfo
->gso_type
== 0)) {
3363 __skb_warn_lro_forwarding(skb
);
3369 static inline void skb_forward_csum(struct sk_buff
*skb
)
3371 /* Unfortunately we don't support this one. Any brave souls? */
3372 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3373 skb
->ip_summed
= CHECKSUM_NONE
;
3377 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3378 * @skb: skb to check
3380 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3381 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3382 * use this helper, to document places where we make this assertion.
3384 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3387 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3391 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3393 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3395 u32
skb_get_poff(const struct sk_buff
*skb
);
3396 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
3397 const struct flow_keys
*keys
, int hlen
);
3400 * skb_head_is_locked - Determine if the skb->head is locked down
3401 * @skb: skb to check
3403 * The head on skbs build around a head frag can be removed if they are
3404 * not cloned. This function returns true if the skb head is locked down
3405 * due to either being allocated via kmalloc, or by being a clone with
3406 * multiple references to the head.
3408 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3410 return !skb
->head_frag
|| skb_cloned(skb
);
3414 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3418 * skb_gso_network_seglen is used to determine the real size of the
3419 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3421 * The MAC/L2 header is not accounted for.
3423 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3425 unsigned int hdr_len
= skb_transport_header(skb
) -
3426 skb_network_header(skb
);
3427 return hdr_len
+ skb_gso_transport_seglen(skb
);
3429 #endif /* __KERNEL__ */
3430 #endif /* _LINUX_SKBUFF_H */