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/compiler.h>
19 #include <linux/time.h>
20 #include <linux/bug.h>
21 #include <linux/cache.h>
22 #include <linux/rbtree.h>
23 #include <linux/socket.h>
24 #include <linux/refcount.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 <linux/sched/clock.h>
38 #include <net/flow_dissector.h>
39 #include <linux/splice.h>
40 #include <linux/in6.h>
41 #include <linux/if_packet.h>
44 /* The interface for checksum offload between the stack and networking drivers
47 * A. IP checksum related features
49 * Drivers advertise checksum offload capabilities in the features of a device.
50 * From the stack's point of view these are capabilities offered by the driver,
51 * a driver typically only advertises features that it is capable of offloading
54 * The checksum related features are:
56 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
57 * IP (one's complement) checksum for any combination
58 * of protocols or protocol layering. The checksum is
59 * computed and set in a packet per the CHECKSUM_PARTIAL
60 * interface (see below).
62 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
63 * TCP or UDP packets over IPv4. These are specifically
64 * unencapsulated packets of the form IPv4|TCP or
65 * IPv4|UDP where the Protocol field in the IPv4 header
66 * is TCP or UDP. The IPv4 header may contain IP options
67 * This feature cannot be set in features for a device
68 * with NETIF_F_HW_CSUM also set. This feature is being
69 * DEPRECATED (see below).
71 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
72 * TCP or UDP packets over IPv6. These are specifically
73 * unencapsulated packets of the form IPv6|TCP or
74 * IPv4|UDP where the Next Header field in the IPv6
75 * header is either TCP or UDP. IPv6 extension headers
76 * are not supported with this feature. This feature
77 * cannot be set in features for a device with
78 * NETIF_F_HW_CSUM also set. This feature is being
79 * DEPRECATED (see below).
81 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
82 * This flag is used only used to disable the RX checksum
83 * feature for a device. The stack will accept receive
84 * checksum indication in packets received on a device
85 * regardless of whether NETIF_F_RXCSUM is set.
87 * B. Checksumming of received packets by device. Indication of checksum
88 * verification is in set skb->ip_summed. Possible values are:
92 * Device did not checksum this packet e.g. due to lack of capabilities.
93 * The packet contains full (though not verified) checksum in packet but
94 * not in skb->csum. Thus, skb->csum is undefined in this case.
96 * CHECKSUM_UNNECESSARY:
98 * The hardware you're dealing with doesn't calculate the full checksum
99 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
100 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
101 * if their checksums are okay. skb->csum is still undefined in this case
102 * though. A driver or device must never modify the checksum field in the
103 * packet even if checksum is verified.
105 * CHECKSUM_UNNECESSARY is applicable to following protocols:
106 * TCP: IPv6 and IPv4.
107 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
108 * zero UDP checksum for either IPv4 or IPv6, the networking stack
109 * may perform further validation in this case.
110 * GRE: only if the checksum is present in the header.
111 * SCTP: indicates the CRC in SCTP header has been validated.
112 * FCOE: indicates the CRC in FC frame has been validated.
114 * skb->csum_level indicates the number of consecutive checksums found in
115 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
116 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
117 * and a device is able to verify the checksums for UDP (possibly zero),
118 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
119 * two. If the device were only able to verify the UDP checksum and not
120 * GRE, either because it doesn't support GRE checksum of because GRE
121 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
122 * not considered in this case).
126 * This is the most generic way. The device supplied checksum of the _whole_
127 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
128 * hardware doesn't need to parse L3/L4 headers to implement this.
131 * - Even if device supports only some protocols, but is able to produce
132 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
133 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
137 * A checksum is set up to be offloaded to a device as described in the
138 * output description for CHECKSUM_PARTIAL. This may occur on a packet
139 * received directly from another Linux OS, e.g., a virtualized Linux kernel
140 * on the same host, or it may be set in the input path in GRO or remote
141 * checksum offload. For the purposes of checksum verification, the checksum
142 * referred to by skb->csum_start + skb->csum_offset and any preceding
143 * checksums in the packet are considered verified. Any checksums in the
144 * packet that are after the checksum being offloaded are not considered to
147 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
148 * in the skb->ip_summed for a packet. Values are:
152 * The driver is required to checksum the packet as seen by hard_start_xmit()
153 * from skb->csum_start up to the end, and to record/write the checksum at
154 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
155 * csum_start and csum_offset values are valid values given the length and
156 * offset of the packet, however they should not attempt to validate that the
157 * checksum refers to a legitimate transport layer checksum-- it is the
158 * purview of the stack to validate that csum_start and csum_offset are set
161 * When the stack requests checksum offload for a packet, the driver MUST
162 * ensure that the checksum is set correctly. A driver can either offload the
163 * checksum calculation to the device, or call skb_checksum_help (in the case
164 * that the device does not support offload for a particular checksum).
166 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
167 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
168 * checksum offload capability.
169 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
170 * on network device checksumming capabilities: if a packet does not match
171 * them, skb_checksum_help or skb_crc32c_help (depending on the value of
172 * csum_not_inet, see item D.) is called to resolve the checksum.
176 * The skb was already checksummed by the protocol, or a checksum is not
179 * CHECKSUM_UNNECESSARY:
181 * This has the same meaning on as CHECKSUM_NONE for checksum offload on
185 * Not used in checksum output. If a driver observes a packet with this value
186 * set in skbuff, if should treat as CHECKSUM_NONE being set.
188 * D. Non-IP checksum (CRC) offloads
190 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
191 * offloading the SCTP CRC in a packet. To perform this offload the stack
192 * will set set csum_start and csum_offset accordingly, set ip_summed to
193 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
194 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
195 * A driver that supports both IP checksum offload and SCTP CRC32c offload
196 * must verify which offload is configured for a packet by testing the
197 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
198 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
200 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
201 * offloading the FCOE CRC in a packet. To perform this offload the stack
202 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
203 * accordingly. Note the there is no indication in the skbuff that the
204 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
205 * both IP checksum offload and FCOE CRC offload must verify which offload
206 * is configured for a packet presumably by inspecting packet headers.
208 * E. Checksumming on output with GSO.
210 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
211 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
212 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
213 * part of the GSO operation is implied. If a checksum is being offloaded
214 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
215 * are set to refer to the outermost checksum being offload (two offloaded
216 * checksums are possible with UDP encapsulation).
219 /* Don't change this without changing skb_csum_unnecessary! */
220 #define CHECKSUM_NONE 0
221 #define CHECKSUM_UNNECESSARY 1
222 #define CHECKSUM_COMPLETE 2
223 #define CHECKSUM_PARTIAL 3
225 /* Maximum value in skb->csum_level */
226 #define SKB_MAX_CSUM_LEVEL 3
228 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
229 #define SKB_WITH_OVERHEAD(X) \
230 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
231 #define SKB_MAX_ORDER(X, ORDER) \
232 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
233 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
234 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
236 /* return minimum truesize of one skb containing X bytes of data */
237 #define SKB_TRUESIZE(X) ((X) + \
238 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
239 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
243 struct pipe_inode_info
;
250 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
251 struct nf_conntrack
{
256 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
257 struct nf_bridge_info
{
259 BRNF_PROTO_UNCHANGED
,
267 struct net_device
*physindev
;
269 /* always valid & non-NULL from FORWARD on, for physdev match */
270 struct net_device
*physoutdev
;
272 /* prerouting: detect dnat in orig/reply direction */
274 struct in6_addr ipv6_daddr
;
276 /* after prerouting + nat detected: store original source
277 * mac since neigh resolution overwrites it, only used while
278 * skb is out in neigh layer.
280 char neigh_header
[8];
285 struct sk_buff_head
{
286 /* These two members must be first. */
287 struct sk_buff
*next
;
288 struct sk_buff
*prev
;
296 /* To allow 64K frame to be packed as single skb without frag_list we
297 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
298 * buffers which do not start on a page boundary.
300 * Since GRO uses frags we allocate at least 16 regardless of page
303 #if (65536/PAGE_SIZE + 1) < 16
304 #define MAX_SKB_FRAGS 16UL
306 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
308 extern int sysctl_max_skb_frags
;
310 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
311 * segment using its current segmentation instead.
313 #define GSO_BY_FRAGS 0xFFFF
315 typedef struct skb_frag_struct skb_frag_t
;
317 struct skb_frag_struct
{
321 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
331 * skb_frag_size - Returns the size of a skb fragment
332 * @frag: skb fragment
334 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
340 * skb_frag_size_set - Sets the size of a skb fragment
341 * @frag: skb fragment
342 * @size: size of fragment
344 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
350 * skb_frag_size_add - Incrementes the size of a skb fragment by %delta
351 * @frag: skb fragment
352 * @delta: value to add
354 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
360 * skb_frag_size_sub - Decrements the size of a skb fragment by %delta
361 * @frag: skb fragment
362 * @delta: value to subtract
364 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
370 * skb_frag_must_loop - Test if %p is a high memory page
371 * @p: fragment's page
373 static inline bool skb_frag_must_loop(struct page
*p
)
375 #if defined(CONFIG_HIGHMEM)
383 * skb_frag_foreach_page - loop over pages in a fragment
385 * @f: skb frag to operate on
386 * @f_off: offset from start of f->page.p
387 * @f_len: length from f_off to loop over
388 * @p: (temp var) current page
389 * @p_off: (temp var) offset from start of current page,
390 * non-zero only on first page.
391 * @p_len: (temp var) length in current page,
392 * < PAGE_SIZE only on first and last page.
393 * @copied: (temp var) length so far, excluding current p_len.
395 * A fragment can hold a compound page, in which case per-page
396 * operations, notably kmap_atomic, must be called for each
399 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
400 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
401 p_off = (f_off) & (PAGE_SIZE - 1), \
402 p_len = skb_frag_must_loop(p) ? \
403 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
406 copied += p_len, p++, p_off = 0, \
407 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
409 #define HAVE_HW_TIME_STAMP
412 * struct skb_shared_hwtstamps - hardware time stamps
413 * @hwtstamp: hardware time stamp transformed into duration
414 * since arbitrary point in time
416 * Software time stamps generated by ktime_get_real() are stored in
419 * hwtstamps can only be compared against other hwtstamps from
422 * This structure is attached to packets as part of the
423 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
425 struct skb_shared_hwtstamps
{
429 /* Definitions for tx_flags in struct skb_shared_info */
431 /* generate hardware time stamp */
432 SKBTX_HW_TSTAMP
= 1 << 0,
434 /* generate software time stamp when queueing packet to NIC */
435 SKBTX_SW_TSTAMP
= 1 << 1,
437 /* device driver is going to provide hardware time stamp */
438 SKBTX_IN_PROGRESS
= 1 << 2,
440 /* device driver supports TX zero-copy buffers */
441 SKBTX_DEV_ZEROCOPY
= 1 << 3,
443 /* generate wifi status information (where possible) */
444 SKBTX_WIFI_STATUS
= 1 << 4,
446 /* This indicates at least one fragment might be overwritten
447 * (as in vmsplice(), sendfile() ...)
448 * If we need to compute a TX checksum, we'll need to copy
449 * all frags to avoid possible bad checksum
451 SKBTX_SHARED_FRAG
= 1 << 5,
453 /* generate software time stamp when entering packet scheduling */
454 SKBTX_SCHED_TSTAMP
= 1 << 6,
457 #define SKBTX_ZEROCOPY_FRAG (SKBTX_DEV_ZEROCOPY | SKBTX_SHARED_FRAG)
458 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
460 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
463 * The callback notifies userspace to release buffers when skb DMA is done in
464 * lower device, the skb last reference should be 0 when calling this.
465 * The zerocopy_success argument is true if zero copy transmit occurred,
466 * false on data copy or out of memory error caused by data copy attempt.
467 * The ctx field is used to track device context.
468 * The desc field is used to track userspace buffer index.
471 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
487 struct user_struct
*user
;
492 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
494 int mm_account_pinned_pages(struct mmpin
*mmp
, size_t size
);
495 void mm_unaccount_pinned_pages(struct mmpin
*mmp
);
497 struct ubuf_info
*sock_zerocopy_alloc(struct sock
*sk
, size_t size
);
498 struct ubuf_info
*sock_zerocopy_realloc(struct sock
*sk
, size_t size
,
499 struct ubuf_info
*uarg
);
501 static inline void sock_zerocopy_get(struct ubuf_info
*uarg
)
503 refcount_inc(&uarg
->refcnt
);
506 void sock_zerocopy_put(struct ubuf_info
*uarg
);
507 void sock_zerocopy_put_abort(struct ubuf_info
*uarg
, bool have_uref
);
509 void sock_zerocopy_callback(struct ubuf_info
*uarg
, bool success
);
511 int skb_zerocopy_iter_dgram(struct sk_buff
*skb
, struct msghdr
*msg
, int len
);
512 int skb_zerocopy_iter_stream(struct sock
*sk
, struct sk_buff
*skb
,
513 struct msghdr
*msg
, int len
,
514 struct ubuf_info
*uarg
);
516 /* This data is invariant across clones and lives at
517 * the end of the header data, ie. at skb->end.
519 struct skb_shared_info
{
524 unsigned short gso_size
;
525 /* Warning: this field is not always filled in (UFO)! */
526 unsigned short gso_segs
;
527 struct sk_buff
*frag_list
;
528 struct skb_shared_hwtstamps hwtstamps
;
529 unsigned int gso_type
;
533 * Warning : all fields before dataref are cleared in __alloc_skb()
537 /* Intermediate layers must ensure that destructor_arg
538 * remains valid until skb destructor */
539 void * destructor_arg
;
541 /* must be last field, see pskb_expand_head() */
542 skb_frag_t frags
[MAX_SKB_FRAGS
];
545 /* We divide dataref into two halves. The higher 16 bits hold references
546 * to the payload part of skb->data. The lower 16 bits hold references to
547 * the entire skb->data. A clone of a headerless skb holds the length of
548 * the header in skb->hdr_len.
550 * All users must obey the rule that the skb->data reference count must be
551 * greater than or equal to the payload reference count.
553 * Holding a reference to the payload part means that the user does not
554 * care about modifications to the header part of skb->data.
556 #define SKB_DATAREF_SHIFT 16
557 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
561 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
562 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
563 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
567 SKB_GSO_TCPV4
= 1 << 0,
569 /* This indicates the skb is from an untrusted source. */
570 SKB_GSO_DODGY
= 1 << 1,
572 /* This indicates the tcp segment has CWR set. */
573 SKB_GSO_TCP_ECN
= 1 << 2,
575 SKB_GSO_TCP_FIXEDID
= 1 << 3,
577 SKB_GSO_TCPV6
= 1 << 4,
579 SKB_GSO_FCOE
= 1 << 5,
581 SKB_GSO_GRE
= 1 << 6,
583 SKB_GSO_GRE_CSUM
= 1 << 7,
585 SKB_GSO_IPXIP4
= 1 << 8,
587 SKB_GSO_IPXIP6
= 1 << 9,
589 SKB_GSO_UDP_TUNNEL
= 1 << 10,
591 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
593 SKB_GSO_PARTIAL
= 1 << 12,
595 SKB_GSO_TUNNEL_REMCSUM
= 1 << 13,
597 SKB_GSO_SCTP
= 1 << 14,
599 SKB_GSO_ESP
= 1 << 15,
601 SKB_GSO_UDP
= 1 << 16,
603 SKB_GSO_UDP_L4
= 1 << 17,
606 #if BITS_PER_LONG > 32
607 #define NET_SKBUFF_DATA_USES_OFFSET 1
610 #ifdef NET_SKBUFF_DATA_USES_OFFSET
611 typedef unsigned int sk_buff_data_t
;
613 typedef unsigned char *sk_buff_data_t
;
617 * struct sk_buff - socket buffer
618 * @next: Next buffer in list
619 * @prev: Previous buffer in list
620 * @tstamp: Time we arrived/left
621 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
622 * @sk: Socket we are owned by
623 * @dev: Device we arrived on/are leaving by
624 * @cb: Control buffer. Free for use by every layer. Put private vars here
625 * @_skb_refdst: destination entry (with norefcount bit)
626 * @sp: the security path, used for xfrm
627 * @len: Length of actual data
628 * @data_len: Data length
629 * @mac_len: Length of link layer header
630 * @hdr_len: writable header length of cloned skb
631 * @csum: Checksum (must include start/offset pair)
632 * @csum_start: Offset from skb->head where checksumming should start
633 * @csum_offset: Offset from csum_start where checksum should be stored
634 * @priority: Packet queueing priority
635 * @ignore_df: allow local fragmentation
636 * @cloned: Head may be cloned (check refcnt to be sure)
637 * @ip_summed: Driver fed us an IP checksum
638 * @nohdr: Payload reference only, must not modify header
639 * @pkt_type: Packet class
640 * @fclone: skbuff clone status
641 * @ipvs_property: skbuff is owned by ipvs
642 * @offload_fwd_mark: Packet was L2-forwarded in hardware
643 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
644 * @tc_skip_classify: do not classify packet. set by IFB device
645 * @tc_at_ingress: used within tc_classify to distinguish in/egress
646 * @tc_redirected: packet was redirected by a tc action
647 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect
648 * @peeked: this packet has been seen already, so stats have been
649 * done for it, don't do them again
650 * @nf_trace: netfilter packet trace flag
651 * @protocol: Packet protocol from driver
652 * @destructor: Destruct function
653 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
654 * @_nfct: Associated connection, if any (with nfctinfo bits)
655 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
656 * @skb_iif: ifindex of device we arrived on
657 * @tc_index: Traffic control index
658 * @hash: the packet hash
659 * @queue_mapping: Queue mapping for multiqueue devices
660 * @xmit_more: More SKBs are pending for this queue
661 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
662 * @active_extensions: active extensions (skb_ext_id types)
663 * @ndisc_nodetype: router type (from link layer)
664 * @ooo_okay: allow the mapping of a socket to a queue to be changed
665 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
667 * @sw_hash: indicates hash was computed in software stack
668 * @wifi_acked_valid: wifi_acked was set
669 * @wifi_acked: whether frame was acked on wifi or not
670 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
671 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
672 * @dst_pending_confirm: need to confirm neighbour
673 * @decrypted: Decrypted SKB
674 * @napi_id: id of the NAPI struct this skb came from
675 * @secmark: security marking
676 * @mark: Generic packet mark
677 * @vlan_proto: vlan encapsulation protocol
678 * @vlan_tci: vlan tag control information
679 * @inner_protocol: Protocol (encapsulation)
680 * @inner_transport_header: Inner transport layer header (encapsulation)
681 * @inner_network_header: Network layer header (encapsulation)
682 * @inner_mac_header: Link layer header (encapsulation)
683 * @transport_header: Transport layer header
684 * @network_header: Network layer header
685 * @mac_header: Link layer header
686 * @tail: Tail pointer
688 * @head: Head of buffer
689 * @data: Data head pointer
690 * @truesize: Buffer size
691 * @users: User count - see {datagram,tcp}.c
692 * @extensions: allocated extensions, valid if active_extensions is nonzero
698 /* These two members must be first. */
699 struct sk_buff
*next
;
700 struct sk_buff
*prev
;
703 struct net_device
*dev
;
704 /* Some protocols might use this space to store information,
705 * while device pointer would be NULL.
706 * UDP receive path is one user.
708 unsigned long dev_scratch
;
711 struct rb_node rbnode
; /* used in netem, ip4 defrag, and tcp stack */
712 struct list_head list
;
717 int ip_defrag_offset
;
722 u64 skb_mstamp_ns
; /* earliest departure time */
725 * This is the control buffer. It is free to use for every
726 * layer. Please put your private variables there. If you
727 * want to keep them across layers you have to do a skb_clone()
728 * first. This is owned by whoever has the skb queued ATM.
730 char cb
[48] __aligned(8);
734 unsigned long _skb_refdst
;
735 void (*destructor
)(struct sk_buff
*skb
);
737 struct list_head tcp_tsorted_anchor
;
740 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
748 /* Following fields are _not_ copied in __copy_skb_header()
749 * Note that queue_mapping is here mostly to fill a hole.
753 /* if you move cloned around you also must adapt those constants */
754 #ifdef __BIG_ENDIAN_BITFIELD
755 #define CLONED_MASK (1 << 7)
757 #define CLONED_MASK 1
759 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
761 __u8 __cloned_offset
[0];
769 #ifdef CONFIG_SKB_EXTENSIONS
770 __u8 active_extensions
;
772 /* fields enclosed in headers_start/headers_end are copied
773 * using a single memcpy() in __copy_skb_header()
776 __u32 headers_start
[0];
779 /* if you move pkt_type around you also must adapt those constants */
780 #ifdef __BIG_ENDIAN_BITFIELD
781 #define PKT_TYPE_MAX (7 << 5)
783 #define PKT_TYPE_MAX 7
785 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
787 __u8 __pkt_type_offset
[0];
796 __u8 wifi_acked_valid
:1;
799 /* Indicates the inner headers are valid in the skbuff. */
800 __u8 encapsulation
:1;
801 __u8 encap_hdr_csum
:1;
804 #ifdef __BIG_ENDIAN_BITFIELD
805 #define PKT_VLAN_PRESENT_BIT 7
807 #define PKT_VLAN_PRESENT_BIT 0
809 #define PKT_VLAN_PRESENT_OFFSET() offsetof(struct sk_buff, __pkt_vlan_present_offset)
810 __u8 __pkt_vlan_present_offset
[0];
812 __u8 csum_complete_sw
:1;
814 __u8 csum_not_inet
:1;
815 __u8 dst_pending_confirm
:1;
816 #ifdef CONFIG_IPV6_NDISC_NODETYPE
817 __u8 ndisc_nodetype
:2;
820 __u8 ipvs_property
:1;
821 __u8 inner_protocol_type
:1;
822 __u8 remcsum_offload
:1;
823 #ifdef CONFIG_NET_SWITCHDEV
824 __u8 offload_fwd_mark
:1;
825 __u8 offload_l3_fwd_mark
:1;
827 #ifdef CONFIG_NET_CLS_ACT
828 __u8 tc_skip_classify
:1;
829 __u8 tc_at_ingress
:1;
830 __u8 tc_redirected
:1;
831 __u8 tc_from_ingress
:1;
833 #ifdef CONFIG_TLS_DEVICE
837 #ifdef CONFIG_NET_SCHED
838 __u16 tc_index
; /* traffic control index */
853 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
855 unsigned int napi_id
;
856 unsigned int sender_cpu
;
859 #ifdef CONFIG_NETWORK_SECMARK
865 __u32 reserved_tailroom
;
869 __be16 inner_protocol
;
873 __u16 inner_transport_header
;
874 __u16 inner_network_header
;
875 __u16 inner_mac_header
;
878 __u16 transport_header
;
879 __u16 network_header
;
883 __u32 headers_end
[0];
886 /* These elements must be at the end, see alloc_skb() for details. */
891 unsigned int truesize
;
894 #ifdef CONFIG_SKB_EXTENSIONS
895 /* only useable after checking ->active_extensions != 0 */
896 struct skb_ext
*extensions
;
902 * Handling routines are only of interest to the kernel
905 #define SKB_ALLOC_FCLONE 0x01
906 #define SKB_ALLOC_RX 0x02
907 #define SKB_ALLOC_NAPI 0x04
910 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
913 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
915 return unlikely(skb
->pfmemalloc
);
919 * skb might have a dst pointer attached, refcounted or not.
920 * _skb_refdst low order bit is set if refcount was _not_ taken
922 #define SKB_DST_NOREF 1UL
923 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
925 #define SKB_NFCT_PTRMASK ~(7UL)
927 * skb_dst - returns skb dst_entry
930 * Returns skb dst_entry, regardless of reference taken or not.
932 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
934 /* If refdst was not refcounted, check we still are in a
935 * rcu_read_lock section
937 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
938 !rcu_read_lock_held() &&
939 !rcu_read_lock_bh_held());
940 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
944 * skb_dst_set - sets skb dst
948 * Sets skb dst, assuming a reference was taken on dst and should
949 * be released by skb_dst_drop()
951 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
953 skb
->_skb_refdst
= (unsigned long)dst
;
957 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
961 * Sets skb dst, assuming a reference was not taken on dst.
962 * If dst entry is cached, we do not take reference and dst_release
963 * will be avoided by refdst_drop. If dst entry is not cached, we take
964 * reference, so that last dst_release can destroy the dst immediately.
966 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
968 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
969 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
973 * skb_dst_is_noref - Test if skb dst isn't refcounted
976 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
978 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
982 * skb_rtable - Returns the skb &rtable
985 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
987 return (struct rtable
*)skb_dst(skb
);
990 /* For mangling skb->pkt_type from user space side from applications
991 * such as nft, tc, etc, we only allow a conservative subset of
992 * possible pkt_types to be set.
994 static inline bool skb_pkt_type_ok(u32 ptype
)
996 return ptype
<= PACKET_OTHERHOST
;
1000 * skb_napi_id - Returns the skb's NAPI id
1003 static inline unsigned int skb_napi_id(const struct sk_buff
*skb
)
1005 #ifdef CONFIG_NET_RX_BUSY_POLL
1006 return skb
->napi_id
;
1013 * skb_unref - decrement the skb's reference count
1016 * Returns true if we can free the skb.
1018 static inline bool skb_unref(struct sk_buff
*skb
)
1022 if (likely(refcount_read(&skb
->users
) == 1))
1024 else if (likely(!refcount_dec_and_test(&skb
->users
)))
1030 void skb_release_head_state(struct sk_buff
*skb
);
1031 void kfree_skb(struct sk_buff
*skb
);
1032 void kfree_skb_list(struct sk_buff
*segs
);
1033 void skb_tx_error(struct sk_buff
*skb
);
1034 void consume_skb(struct sk_buff
*skb
);
1035 void __consume_stateless_skb(struct sk_buff
*skb
);
1036 void __kfree_skb(struct sk_buff
*skb
);
1037 extern struct kmem_cache
*skbuff_head_cache
;
1039 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
1040 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
1041 bool *fragstolen
, int *delta_truesize
);
1043 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
1045 struct sk_buff
*__build_skb(void *data
, unsigned int frag_size
);
1046 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
1049 * alloc_skb - allocate a network buffer
1050 * @size: size to allocate
1051 * @priority: allocation mask
1053 * This function is a convenient wrapper around __alloc_skb().
1055 static inline struct sk_buff
*alloc_skb(unsigned int size
,
1058 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
1061 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
1062 unsigned long data_len
,
1067 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1068 struct sk_buff_fclones
{
1069 struct sk_buff skb1
;
1071 struct sk_buff skb2
;
1073 refcount_t fclone_ref
;
1077 * skb_fclone_busy - check if fclone is busy
1081 * Returns true if skb is a fast clone, and its clone is not freed.
1082 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1083 * so we also check that this didnt happen.
1085 static inline bool skb_fclone_busy(const struct sock
*sk
,
1086 const struct sk_buff
*skb
)
1088 const struct sk_buff_fclones
*fclones
;
1090 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
1092 return skb
->fclone
== SKB_FCLONE_ORIG
&&
1093 refcount_read(&fclones
->fclone_ref
) > 1 &&
1094 fclones
->skb2
.sk
== sk
;
1098 * alloc_skb_fclone - allocate a network buffer from fclone cache
1099 * @size: size to allocate
1100 * @priority: allocation mask
1102 * This function is a convenient wrapper around __alloc_skb().
1104 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
1107 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
1110 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
1111 void skb_headers_offset_update(struct sk_buff
*skb
, int off
);
1112 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
1113 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
1114 void skb_copy_header(struct sk_buff
*new, const struct sk_buff
*old
);
1115 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
1116 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
1117 gfp_t gfp_mask
, bool fclone
);
1118 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
1121 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
1124 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
1125 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
1126 unsigned int headroom
);
1127 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
1128 int newtailroom
, gfp_t priority
);
1129 int __must_check
skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
1130 int offset
, int len
);
1131 int __must_check
skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
,
1132 int offset
, int len
);
1133 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
1134 int __skb_pad(struct sk_buff
*skb
, int pad
, bool free_on_error
);
1137 * skb_pad - zero pad the tail of an skb
1138 * @skb: buffer to pad
1139 * @pad: space to pad
1141 * Ensure that a buffer is followed by a padding area that is zero
1142 * filled. Used by network drivers which may DMA or transfer data
1143 * beyond the buffer end onto the wire.
1145 * May return error in out of memory cases. The skb is freed on error.
1147 static inline int skb_pad(struct sk_buff
*skb
, int pad
)
1149 return __skb_pad(skb
, pad
, true);
1151 #define dev_kfree_skb(a) consume_skb(a)
1153 int skb_append_pagefrags(struct sk_buff
*skb
, struct page
*page
,
1154 int offset
, size_t size
);
1156 struct skb_seq_state
{
1160 __u32 stepped_offset
;
1161 struct sk_buff
*root_skb
;
1162 struct sk_buff
*cur_skb
;
1166 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1167 unsigned int to
, struct skb_seq_state
*st
);
1168 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1169 struct skb_seq_state
*st
);
1170 void skb_abort_seq_read(struct skb_seq_state
*st
);
1172 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1173 unsigned int to
, struct ts_config
*config
);
1176 * Packet hash types specify the type of hash in skb_set_hash.
1178 * Hash types refer to the protocol layer addresses which are used to
1179 * construct a packet's hash. The hashes are used to differentiate or identify
1180 * flows of the protocol layer for the hash type. Hash types are either
1181 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1183 * Properties of hashes:
1185 * 1) Two packets in different flows have different hash values
1186 * 2) Two packets in the same flow should have the same hash value
1188 * A hash at a higher layer is considered to be more specific. A driver should
1189 * set the most specific hash possible.
1191 * A driver cannot indicate a more specific hash than the layer at which a hash
1192 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1194 * A driver may indicate a hash level which is less specific than the
1195 * actual layer the hash was computed on. For instance, a hash computed
1196 * at L4 may be considered an L3 hash. This should only be done if the
1197 * driver can't unambiguously determine that the HW computed the hash at
1198 * the higher layer. Note that the "should" in the second property above
1201 enum pkt_hash_types
{
1202 PKT_HASH_TYPE_NONE
, /* Undefined type */
1203 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
1204 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
1205 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
1208 static inline void skb_clear_hash(struct sk_buff
*skb
)
1215 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
1218 skb_clear_hash(skb
);
1222 __skb_set_hash(struct sk_buff
*skb
, __u32 hash
, bool is_sw
, bool is_l4
)
1224 skb
->l4_hash
= is_l4
;
1225 skb
->sw_hash
= is_sw
;
1230 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
1232 /* Used by drivers to set hash from HW */
1233 __skb_set_hash(skb
, hash
, false, type
== PKT_HASH_TYPE_L4
);
1237 __skb_set_sw_hash(struct sk_buff
*skb
, __u32 hash
, bool is_l4
)
1239 __skb_set_hash(skb
, hash
, true, is_l4
);
1242 void __skb_get_hash(struct sk_buff
*skb
);
1243 u32
__skb_get_hash_symmetric(const struct sk_buff
*skb
);
1244 u32
skb_get_poff(const struct sk_buff
*skb
);
1245 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
1246 const struct flow_keys_basic
*keys
, int hlen
);
1247 __be32
__skb_flow_get_ports(const struct sk_buff
*skb
, int thoff
, u8 ip_proto
,
1248 void *data
, int hlen_proto
);
1250 static inline __be32
skb_flow_get_ports(const struct sk_buff
*skb
,
1251 int thoff
, u8 ip_proto
)
1253 return __skb_flow_get_ports(skb
, thoff
, ip_proto
, NULL
, 0);
1256 void skb_flow_dissector_init(struct flow_dissector
*flow_dissector
,
1257 const struct flow_dissector_key
*key
,
1258 unsigned int key_count
);
1261 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr
*attr
,
1262 struct bpf_prog
*prog
);
1264 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr
*attr
);
1266 static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr
*attr
,
1267 struct bpf_prog
*prog
)
1272 static inline int skb_flow_dissector_bpf_prog_detach(const union bpf_attr
*attr
)
1278 struct bpf_flow_keys
;
1279 bool __skb_flow_bpf_dissect(struct bpf_prog
*prog
,
1280 const struct sk_buff
*skb
,
1281 struct flow_dissector
*flow_dissector
,
1282 struct bpf_flow_keys
*flow_keys
);
1283 bool __skb_flow_dissect(const struct sk_buff
*skb
,
1284 struct flow_dissector
*flow_dissector
,
1285 void *target_container
,
1286 void *data
, __be16 proto
, int nhoff
, int hlen
,
1287 unsigned int flags
);
1289 static inline bool skb_flow_dissect(const struct sk_buff
*skb
,
1290 struct flow_dissector
*flow_dissector
,
1291 void *target_container
, unsigned int flags
)
1293 return __skb_flow_dissect(skb
, flow_dissector
, target_container
,
1294 NULL
, 0, 0, 0, flags
);
1297 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff
*skb
,
1298 struct flow_keys
*flow
,
1301 memset(flow
, 0, sizeof(*flow
));
1302 return __skb_flow_dissect(skb
, &flow_keys_dissector
, flow
,
1303 NULL
, 0, 0, 0, flags
);
1307 skb_flow_dissect_flow_keys_basic(const struct sk_buff
*skb
,
1308 struct flow_keys_basic
*flow
, void *data
,
1309 __be16 proto
, int nhoff
, int hlen
,
1312 memset(flow
, 0, sizeof(*flow
));
1313 return __skb_flow_dissect(skb
, &flow_keys_basic_dissector
, flow
,
1314 data
, proto
, nhoff
, hlen
, flags
);
1318 skb_flow_dissect_tunnel_info(const struct sk_buff
*skb
,
1319 struct flow_dissector
*flow_dissector
,
1320 void *target_container
);
1322 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
1324 if (!skb
->l4_hash
&& !skb
->sw_hash
)
1325 __skb_get_hash(skb
);
1330 static inline __u32
skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
)
1332 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1333 struct flow_keys keys
;
1334 __u32 hash
= __get_hash_from_flowi6(fl6
, &keys
);
1336 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1342 __u32
skb_get_hash_perturb(const struct sk_buff
*skb
, u32 perturb
);
1344 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
1349 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
1351 to
->hash
= from
->hash
;
1352 to
->sw_hash
= from
->sw_hash
;
1353 to
->l4_hash
= from
->l4_hash
;
1356 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1357 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1359 return skb
->head
+ skb
->end
;
1362 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1367 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1372 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1374 return skb
->end
- skb
->head
;
1379 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1381 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
1383 return &skb_shinfo(skb
)->hwtstamps
;
1386 static inline struct ubuf_info
*skb_zcopy(struct sk_buff
*skb
)
1388 bool is_zcopy
= skb
&& skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
;
1390 return is_zcopy
? skb_uarg(skb
) : NULL
;
1393 static inline void skb_zcopy_set(struct sk_buff
*skb
, struct ubuf_info
*uarg
,
1396 if (skb
&& uarg
&& !skb_zcopy(skb
)) {
1397 if (unlikely(have_ref
&& *have_ref
))
1400 sock_zerocopy_get(uarg
);
1401 skb_shinfo(skb
)->destructor_arg
= uarg
;
1402 skb_shinfo(skb
)->tx_flags
|= SKBTX_ZEROCOPY_FRAG
;
1406 static inline void skb_zcopy_set_nouarg(struct sk_buff
*skb
, void *val
)
1408 skb_shinfo(skb
)->destructor_arg
= (void *)((uintptr_t) val
| 0x1UL
);
1409 skb_shinfo(skb
)->tx_flags
|= SKBTX_ZEROCOPY_FRAG
;
1412 static inline bool skb_zcopy_is_nouarg(struct sk_buff
*skb
)
1414 return (uintptr_t) skb_shinfo(skb
)->destructor_arg
& 0x1UL
;
1417 static inline void *skb_zcopy_get_nouarg(struct sk_buff
*skb
)
1419 return (void *)((uintptr_t) skb_shinfo(skb
)->destructor_arg
& ~0x1UL
);
1422 /* Release a reference on a zerocopy structure */
1423 static inline void skb_zcopy_clear(struct sk_buff
*skb
, bool zerocopy
)
1425 struct ubuf_info
*uarg
= skb_zcopy(skb
);
1428 if (uarg
->callback
== sock_zerocopy_callback
) {
1429 uarg
->zerocopy
= uarg
->zerocopy
&& zerocopy
;
1430 sock_zerocopy_put(uarg
);
1431 } else if (!skb_zcopy_is_nouarg(skb
)) {
1432 uarg
->callback(uarg
, zerocopy
);
1435 skb_shinfo(skb
)->tx_flags
&= ~SKBTX_ZEROCOPY_FRAG
;
1439 /* Abort a zerocopy operation and revert zckey on error in send syscall */
1440 static inline void skb_zcopy_abort(struct sk_buff
*skb
)
1442 struct ubuf_info
*uarg
= skb_zcopy(skb
);
1445 sock_zerocopy_put_abort(uarg
, false);
1446 skb_shinfo(skb
)->tx_flags
&= ~SKBTX_ZEROCOPY_FRAG
;
1450 static inline void skb_mark_not_on_list(struct sk_buff
*skb
)
1455 static inline void skb_list_del_init(struct sk_buff
*skb
)
1457 __list_del_entry(&skb
->list
);
1458 skb_mark_not_on_list(skb
);
1462 * skb_queue_empty - check if a queue is empty
1465 * Returns true if the queue is empty, false otherwise.
1467 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1469 return list
->next
== (const struct sk_buff
*) list
;
1473 * skb_queue_is_last - check if skb is the last entry in the queue
1477 * Returns true if @skb is the last buffer on the list.
1479 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1480 const struct sk_buff
*skb
)
1482 return skb
->next
== (const struct sk_buff
*) list
;
1486 * skb_queue_is_first - check if skb is the first entry in the queue
1490 * Returns true if @skb is the first buffer on the list.
1492 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1493 const struct sk_buff
*skb
)
1495 return skb
->prev
== (const struct sk_buff
*) list
;
1499 * skb_queue_next - return the next packet in the queue
1501 * @skb: current buffer
1503 * Return the next packet in @list after @skb. It is only valid to
1504 * call this if skb_queue_is_last() evaluates to false.
1506 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1507 const struct sk_buff
*skb
)
1509 /* This BUG_ON may seem severe, but if we just return then we
1510 * are going to dereference garbage.
1512 BUG_ON(skb_queue_is_last(list
, skb
));
1517 * skb_queue_prev - return the prev packet in the queue
1519 * @skb: current buffer
1521 * Return the prev packet in @list before @skb. It is only valid to
1522 * call this if skb_queue_is_first() evaluates to false.
1524 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1525 const struct sk_buff
*skb
)
1527 /* This BUG_ON may seem severe, but if we just return then we
1528 * are going to dereference garbage.
1530 BUG_ON(skb_queue_is_first(list
, skb
));
1535 * skb_get - reference buffer
1536 * @skb: buffer to reference
1538 * Makes another reference to a socket buffer and returns a pointer
1541 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1543 refcount_inc(&skb
->users
);
1548 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1552 * skb_cloned - is the buffer a clone
1553 * @skb: buffer to check
1555 * Returns true if the buffer was generated with skb_clone() and is
1556 * one of multiple shared copies of the buffer. Cloned buffers are
1557 * shared data so must not be written to under normal circumstances.
1559 static inline int skb_cloned(const struct sk_buff
*skb
)
1561 return skb
->cloned
&&
1562 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1565 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1567 might_sleep_if(gfpflags_allow_blocking(pri
));
1569 if (skb_cloned(skb
))
1570 return pskb_expand_head(skb
, 0, 0, pri
);
1576 * skb_header_cloned - is the header a clone
1577 * @skb: buffer to check
1579 * Returns true if modifying the header part of the buffer requires
1580 * the data to be copied.
1582 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1589 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1590 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1591 return dataref
!= 1;
1594 static inline int skb_header_unclone(struct sk_buff
*skb
, gfp_t pri
)
1596 might_sleep_if(gfpflags_allow_blocking(pri
));
1598 if (skb_header_cloned(skb
))
1599 return pskb_expand_head(skb
, 0, 0, pri
);
1605 * __skb_header_release - release reference to header
1606 * @skb: buffer to operate on
1608 static inline void __skb_header_release(struct sk_buff
*skb
)
1611 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1616 * skb_shared - is the buffer shared
1617 * @skb: buffer to check
1619 * Returns true if more than one person has a reference to this
1622 static inline int skb_shared(const struct sk_buff
*skb
)
1624 return refcount_read(&skb
->users
) != 1;
1628 * skb_share_check - check if buffer is shared and if so clone it
1629 * @skb: buffer to check
1630 * @pri: priority for memory allocation
1632 * If the buffer is shared the buffer is cloned and the old copy
1633 * drops a reference. A new clone with a single reference is returned.
1634 * If the buffer is not shared the original buffer is returned. When
1635 * being called from interrupt status or with spinlocks held pri must
1638 * NULL is returned on a memory allocation failure.
1640 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1642 might_sleep_if(gfpflags_allow_blocking(pri
));
1643 if (skb_shared(skb
)) {
1644 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1656 * Copy shared buffers into a new sk_buff. We effectively do COW on
1657 * packets to handle cases where we have a local reader and forward
1658 * and a couple of other messy ones. The normal one is tcpdumping
1659 * a packet thats being forwarded.
1663 * skb_unshare - make a copy of a shared buffer
1664 * @skb: buffer to check
1665 * @pri: priority for memory allocation
1667 * If the socket buffer is a clone then this function creates a new
1668 * copy of the data, drops a reference count on the old copy and returns
1669 * the new copy with the reference count at 1. If the buffer is not a clone
1670 * the original buffer is returned. When called with a spinlock held or
1671 * from interrupt state @pri must be %GFP_ATOMIC
1673 * %NULL is returned on a memory allocation failure.
1675 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1678 might_sleep_if(gfpflags_allow_blocking(pri
));
1679 if (skb_cloned(skb
)) {
1680 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1682 /* Free our shared copy */
1693 * skb_peek - peek at the head of an &sk_buff_head
1694 * @list_: list to peek at
1696 * Peek an &sk_buff. Unlike most other operations you _MUST_
1697 * be careful with this one. A peek leaves the buffer on the
1698 * list and someone else may run off with it. You must hold
1699 * the appropriate locks or have a private queue to do this.
1701 * Returns %NULL for an empty list or a pointer to the head element.
1702 * The reference count is not incremented and the reference is therefore
1703 * volatile. Use with caution.
1705 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1707 struct sk_buff
*skb
= list_
->next
;
1709 if (skb
== (struct sk_buff
*)list_
)
1715 * __skb_peek - peek at the head of a non-empty &sk_buff_head
1716 * @list_: list to peek at
1718 * Like skb_peek(), but the caller knows that the list is not empty.
1720 static inline struct sk_buff
*__skb_peek(const struct sk_buff_head
*list_
)
1726 * skb_peek_next - peek skb following the given one from a queue
1727 * @skb: skb to start from
1728 * @list_: list to peek at
1730 * Returns %NULL when the end of the list is met or a pointer to the
1731 * next element. The reference count is not incremented and the
1732 * reference is therefore volatile. Use with caution.
1734 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1735 const struct sk_buff_head
*list_
)
1737 struct sk_buff
*next
= skb
->next
;
1739 if (next
== (struct sk_buff
*)list_
)
1745 * skb_peek_tail - peek at the tail of an &sk_buff_head
1746 * @list_: list to peek at
1748 * Peek an &sk_buff. Unlike most other operations you _MUST_
1749 * be careful with this one. A peek leaves the buffer on the
1750 * list and someone else may run off with it. You must hold
1751 * the appropriate locks or have a private queue to do this.
1753 * Returns %NULL for an empty list or a pointer to the tail element.
1754 * The reference count is not incremented and the reference is therefore
1755 * volatile. Use with caution.
1757 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1759 struct sk_buff
*skb
= list_
->prev
;
1761 if (skb
== (struct sk_buff
*)list_
)
1768 * skb_queue_len - get queue length
1769 * @list_: list to measure
1771 * Return the length of an &sk_buff queue.
1773 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1779 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1780 * @list: queue to initialize
1782 * This initializes only the list and queue length aspects of
1783 * an sk_buff_head object. This allows to initialize the list
1784 * aspects of an sk_buff_head without reinitializing things like
1785 * the spinlock. It can also be used for on-stack sk_buff_head
1786 * objects where the spinlock is known to not be used.
1788 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1790 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1795 * This function creates a split out lock class for each invocation;
1796 * this is needed for now since a whole lot of users of the skb-queue
1797 * infrastructure in drivers have different locking usage (in hardirq)
1798 * than the networking core (in softirq only). In the long run either the
1799 * network layer or drivers should need annotation to consolidate the
1800 * main types of usage into 3 classes.
1802 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1804 spin_lock_init(&list
->lock
);
1805 __skb_queue_head_init(list
);
1808 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1809 struct lock_class_key
*class)
1811 skb_queue_head_init(list
);
1812 lockdep_set_class(&list
->lock
, class);
1816 * Insert an sk_buff on a list.
1818 * The "__skb_xxxx()" functions are the non-atomic ones that
1819 * can only be called with interrupts disabled.
1821 static inline void __skb_insert(struct sk_buff
*newsk
,
1822 struct sk_buff
*prev
, struct sk_buff
*next
,
1823 struct sk_buff_head
*list
)
1827 next
->prev
= prev
->next
= newsk
;
1831 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1832 struct sk_buff
*prev
,
1833 struct sk_buff
*next
)
1835 struct sk_buff
*first
= list
->next
;
1836 struct sk_buff
*last
= list
->prev
;
1846 * skb_queue_splice - join two skb lists, this is designed for stacks
1847 * @list: the new list to add
1848 * @head: the place to add it in the first list
1850 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1851 struct sk_buff_head
*head
)
1853 if (!skb_queue_empty(list
)) {
1854 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1855 head
->qlen
+= list
->qlen
;
1860 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1861 * @list: the new list to add
1862 * @head: the place to add it in the first list
1864 * The list at @list is reinitialised
1866 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1867 struct sk_buff_head
*head
)
1869 if (!skb_queue_empty(list
)) {
1870 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1871 head
->qlen
+= list
->qlen
;
1872 __skb_queue_head_init(list
);
1877 * skb_queue_splice_tail - join two skb lists, each list being a queue
1878 * @list: the new list to add
1879 * @head: the place to add it in the first list
1881 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1882 struct sk_buff_head
*head
)
1884 if (!skb_queue_empty(list
)) {
1885 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1886 head
->qlen
+= list
->qlen
;
1891 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1892 * @list: the new list to add
1893 * @head: the place to add it in the first list
1895 * Each of the lists is a queue.
1896 * The list at @list is reinitialised
1898 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1899 struct sk_buff_head
*head
)
1901 if (!skb_queue_empty(list
)) {
1902 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1903 head
->qlen
+= list
->qlen
;
1904 __skb_queue_head_init(list
);
1909 * __skb_queue_after - queue a buffer at the list head
1910 * @list: list to use
1911 * @prev: place after this buffer
1912 * @newsk: buffer to queue
1914 * Queue a buffer int the middle of a list. This function takes no locks
1915 * and you must therefore hold required locks before calling it.
1917 * A buffer cannot be placed on two lists at the same time.
1919 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1920 struct sk_buff
*prev
,
1921 struct sk_buff
*newsk
)
1923 __skb_insert(newsk
, prev
, prev
->next
, list
);
1926 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1927 struct sk_buff_head
*list
);
1929 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1930 struct sk_buff
*next
,
1931 struct sk_buff
*newsk
)
1933 __skb_insert(newsk
, next
->prev
, next
, list
);
1937 * __skb_queue_head - queue a buffer at the list head
1938 * @list: list to use
1939 * @newsk: buffer to queue
1941 * Queue a buffer at the start of a list. This function takes no locks
1942 * and you must therefore hold required locks before calling it.
1944 * A buffer cannot be placed on two lists at the same time.
1946 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1947 struct sk_buff
*newsk
)
1949 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1951 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1954 * __skb_queue_tail - queue a buffer at the list tail
1955 * @list: list to use
1956 * @newsk: buffer to queue
1958 * Queue a buffer at the end of a list. This function takes no locks
1959 * and you must therefore hold required locks before calling it.
1961 * A buffer cannot be placed on two lists at the same time.
1963 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1964 struct sk_buff
*newsk
)
1966 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1968 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1971 * remove sk_buff from list. _Must_ be called atomically, and with
1974 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1975 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1977 struct sk_buff
*next
, *prev
;
1982 skb
->next
= skb
->prev
= NULL
;
1988 * __skb_dequeue - remove from the head of the queue
1989 * @list: list to dequeue from
1991 * Remove the head of the list. This function does not take any locks
1992 * so must be used with appropriate locks held only. The head item is
1993 * returned or %NULL if the list is empty.
1995 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1997 struct sk_buff
*skb
= skb_peek(list
);
1999 __skb_unlink(skb
, list
);
2002 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
2005 * __skb_dequeue_tail - remove from the tail of the queue
2006 * @list: list to dequeue from
2008 * Remove the tail of the list. This function does not take any locks
2009 * so must be used with appropriate locks held only. The tail item is
2010 * returned or %NULL if the list is empty.
2012 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
2014 struct sk_buff
*skb
= skb_peek_tail(list
);
2016 __skb_unlink(skb
, list
);
2019 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
2022 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
2024 return skb
->data_len
;
2027 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
2029 return skb
->len
- skb
->data_len
;
2032 static inline unsigned int __skb_pagelen(const struct sk_buff
*skb
)
2034 unsigned int i
, len
= 0;
2036 for (i
= skb_shinfo(skb
)->nr_frags
- 1; (int)i
>= 0; i
--)
2037 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
2041 static inline unsigned int skb_pagelen(const struct sk_buff
*skb
)
2043 return skb_headlen(skb
) + __skb_pagelen(skb
);
2047 * __skb_fill_page_desc - initialise a paged fragment in an skb
2048 * @skb: buffer containing fragment to be initialised
2049 * @i: paged fragment index to initialise
2050 * @page: the page to use for this fragment
2051 * @off: the offset to the data with @page
2052 * @size: the length of the data
2054 * Initialises the @i'th fragment of @skb to point to &size bytes at
2055 * offset @off within @page.
2057 * Does not take any additional reference on the fragment.
2059 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
2060 struct page
*page
, int off
, int size
)
2062 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
2065 * Propagate page pfmemalloc to the skb if we can. The problem is
2066 * that not all callers have unique ownership of the page but rely
2067 * on page_is_pfmemalloc doing the right thing(tm).
2069 frag
->page
.p
= page
;
2070 frag
->page_offset
= off
;
2071 skb_frag_size_set(frag
, size
);
2073 page
= compound_head(page
);
2074 if (page_is_pfmemalloc(page
))
2075 skb
->pfmemalloc
= true;
2079 * skb_fill_page_desc - initialise a paged fragment in an skb
2080 * @skb: buffer containing fragment to be initialised
2081 * @i: paged fragment index to initialise
2082 * @page: the page to use for this fragment
2083 * @off: the offset to the data with @page
2084 * @size: the length of the data
2086 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2087 * @skb to point to @size bytes at offset @off within @page. In
2088 * addition updates @skb such that @i is the last fragment.
2090 * Does not take any additional reference on the fragment.
2092 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
2093 struct page
*page
, int off
, int size
)
2095 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
2096 skb_shinfo(skb
)->nr_frags
= i
+ 1;
2099 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
2100 int size
, unsigned int truesize
);
2102 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
2103 unsigned int truesize
);
2105 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
2106 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
2107 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2109 #ifdef NET_SKBUFF_DATA_USES_OFFSET
2110 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
2112 return skb
->head
+ skb
->tail
;
2115 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
2117 skb
->tail
= skb
->data
- skb
->head
;
2120 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
2122 skb_reset_tail_pointer(skb
);
2123 skb
->tail
+= offset
;
2126 #else /* NET_SKBUFF_DATA_USES_OFFSET */
2127 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
2132 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
2134 skb
->tail
= skb
->data
;
2137 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
2139 skb
->tail
= skb
->data
+ offset
;
2142 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2145 * Add data to an sk_buff
2147 void *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
2148 void *skb_put(struct sk_buff
*skb
, unsigned int len
);
2149 static inline void *__skb_put(struct sk_buff
*skb
, unsigned int len
)
2151 void *tmp
= skb_tail_pointer(skb
);
2152 SKB_LINEAR_ASSERT(skb
);
2158 static inline void *__skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
2160 void *tmp
= __skb_put(skb
, len
);
2162 memset(tmp
, 0, len
);
2166 static inline void *__skb_put_data(struct sk_buff
*skb
, const void *data
,
2169 void *tmp
= __skb_put(skb
, len
);
2171 memcpy(tmp
, data
, len
);
2175 static inline void __skb_put_u8(struct sk_buff
*skb
, u8 val
)
2177 *(u8
*)__skb_put(skb
, 1) = val
;
2180 static inline void *skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
2182 void *tmp
= skb_put(skb
, len
);
2184 memset(tmp
, 0, len
);
2189 static inline void *skb_put_data(struct sk_buff
*skb
, const void *data
,
2192 void *tmp
= skb_put(skb
, len
);
2194 memcpy(tmp
, data
, len
);
2199 static inline void skb_put_u8(struct sk_buff
*skb
, u8 val
)
2201 *(u8
*)skb_put(skb
, 1) = val
;
2204 void *skb_push(struct sk_buff
*skb
, unsigned int len
);
2205 static inline void *__skb_push(struct sk_buff
*skb
, unsigned int len
)
2212 void *skb_pull(struct sk_buff
*skb
, unsigned int len
);
2213 static inline void *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
2216 BUG_ON(skb
->len
< skb
->data_len
);
2217 return skb
->data
+= len
;
2220 static inline void *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
2222 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
2225 void *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
2227 static inline void *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
2229 if (len
> skb_headlen(skb
) &&
2230 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
2233 return skb
->data
+= len
;
2236 static inline void *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
2238 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
2241 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
2243 if (likely(len
<= skb_headlen(skb
)))
2245 if (unlikely(len
> skb
->len
))
2247 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
2250 void skb_condense(struct sk_buff
*skb
);
2253 * skb_headroom - bytes at buffer head
2254 * @skb: buffer to check
2256 * Return the number of bytes of free space at the head of an &sk_buff.
2258 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
2260 return skb
->data
- skb
->head
;
2264 * skb_tailroom - bytes at buffer end
2265 * @skb: buffer to check
2267 * Return the number of bytes of free space at the tail of an sk_buff
2269 static inline int skb_tailroom(const struct sk_buff
*skb
)
2271 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
2275 * skb_availroom - bytes at buffer end
2276 * @skb: buffer to check
2278 * Return the number of bytes of free space at the tail of an sk_buff
2279 * allocated by sk_stream_alloc()
2281 static inline int skb_availroom(const struct sk_buff
*skb
)
2283 if (skb_is_nonlinear(skb
))
2286 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
2290 * skb_reserve - adjust headroom
2291 * @skb: buffer to alter
2292 * @len: bytes to move
2294 * Increase the headroom of an empty &sk_buff by reducing the tail
2295 * room. This is only allowed for an empty buffer.
2297 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
2304 * skb_tailroom_reserve - adjust reserved_tailroom
2305 * @skb: buffer to alter
2306 * @mtu: maximum amount of headlen permitted
2307 * @needed_tailroom: minimum amount of reserved_tailroom
2309 * Set reserved_tailroom so that headlen can be as large as possible but
2310 * not larger than mtu and tailroom cannot be smaller than
2312 * The required headroom should already have been reserved before using
2315 static inline void skb_tailroom_reserve(struct sk_buff
*skb
, unsigned int mtu
,
2316 unsigned int needed_tailroom
)
2318 SKB_LINEAR_ASSERT(skb
);
2319 if (mtu
< skb_tailroom(skb
) - needed_tailroom
)
2320 /* use at most mtu */
2321 skb
->reserved_tailroom
= skb_tailroom(skb
) - mtu
;
2323 /* use up to all available space */
2324 skb
->reserved_tailroom
= needed_tailroom
;
2327 #define ENCAP_TYPE_ETHER 0
2328 #define ENCAP_TYPE_IPPROTO 1
2330 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
2333 skb
->inner_protocol
= protocol
;
2334 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
2337 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
2340 skb
->inner_ipproto
= ipproto
;
2341 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
2344 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
2346 skb
->inner_mac_header
= skb
->mac_header
;
2347 skb
->inner_network_header
= skb
->network_header
;
2348 skb
->inner_transport_header
= skb
->transport_header
;
2351 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
2353 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
2356 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2359 return skb
->head
+ skb
->inner_transport_header
;
2362 static inline int skb_inner_transport_offset(const struct sk_buff
*skb
)
2364 return skb_inner_transport_header(skb
) - skb
->data
;
2367 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
2369 skb
->inner_transport_header
= skb
->data
- skb
->head
;
2372 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
2375 skb_reset_inner_transport_header(skb
);
2376 skb
->inner_transport_header
+= offset
;
2379 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
2381 return skb
->head
+ skb
->inner_network_header
;
2384 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
2386 skb
->inner_network_header
= skb
->data
- skb
->head
;
2389 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
2392 skb_reset_inner_network_header(skb
);
2393 skb
->inner_network_header
+= offset
;
2396 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
2398 return skb
->head
+ skb
->inner_mac_header
;
2401 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
2403 skb
->inner_mac_header
= skb
->data
- skb
->head
;
2406 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
2409 skb_reset_inner_mac_header(skb
);
2410 skb
->inner_mac_header
+= offset
;
2412 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
2414 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
2417 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
2419 return skb
->head
+ skb
->transport_header
;
2422 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
2424 skb
->transport_header
= skb
->data
- skb
->head
;
2427 static inline void skb_set_transport_header(struct sk_buff
*skb
,
2430 skb_reset_transport_header(skb
);
2431 skb
->transport_header
+= offset
;
2434 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
2436 return skb
->head
+ skb
->network_header
;
2439 static inline void skb_reset_network_header(struct sk_buff
*skb
)
2441 skb
->network_header
= skb
->data
- skb
->head
;
2444 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
2446 skb_reset_network_header(skb
);
2447 skb
->network_header
+= offset
;
2450 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
2452 return skb
->head
+ skb
->mac_header
;
2455 static inline int skb_mac_offset(const struct sk_buff
*skb
)
2457 return skb_mac_header(skb
) - skb
->data
;
2460 static inline u32
skb_mac_header_len(const struct sk_buff
*skb
)
2462 return skb
->network_header
- skb
->mac_header
;
2465 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
2467 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
2470 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
2472 skb
->mac_header
= skb
->data
- skb
->head
;
2475 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
2477 skb_reset_mac_header(skb
);
2478 skb
->mac_header
+= offset
;
2481 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
2483 skb
->mac_header
= skb
->network_header
;
2486 static inline void skb_probe_transport_header(struct sk_buff
*skb
)
2488 struct flow_keys_basic keys
;
2490 if (skb_transport_header_was_set(skb
))
2493 if (skb_flow_dissect_flow_keys_basic(skb
, &keys
, NULL
, 0, 0, 0, 0))
2494 skb_set_transport_header(skb
, keys
.control
.thoff
);
2497 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
2499 if (skb_mac_header_was_set(skb
)) {
2500 const unsigned char *old_mac
= skb_mac_header(skb
);
2502 skb_set_mac_header(skb
, -skb
->mac_len
);
2503 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
2507 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
2509 return skb
->csum_start
- skb_headroom(skb
);
2512 static inline unsigned char *skb_checksum_start(const struct sk_buff
*skb
)
2514 return skb
->head
+ skb
->csum_start
;
2517 static inline int skb_transport_offset(const struct sk_buff
*skb
)
2519 return skb_transport_header(skb
) - skb
->data
;
2522 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
2524 return skb
->transport_header
- skb
->network_header
;
2527 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
2529 return skb
->inner_transport_header
- skb
->inner_network_header
;
2532 static inline int skb_network_offset(const struct sk_buff
*skb
)
2534 return skb_network_header(skb
) - skb
->data
;
2537 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
2539 return skb_inner_network_header(skb
) - skb
->data
;
2542 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
2544 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
2548 * CPUs often take a performance hit when accessing unaligned memory
2549 * locations. The actual performance hit varies, it can be small if the
2550 * hardware handles it or large if we have to take an exception and fix it
2553 * Since an ethernet header is 14 bytes network drivers often end up with
2554 * the IP header at an unaligned offset. The IP header can be aligned by
2555 * shifting the start of the packet by 2 bytes. Drivers should do this
2558 * skb_reserve(skb, NET_IP_ALIGN);
2560 * The downside to this alignment of the IP header is that the DMA is now
2561 * unaligned. On some architectures the cost of an unaligned DMA is high
2562 * and this cost outweighs the gains made by aligning the IP header.
2564 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2567 #ifndef NET_IP_ALIGN
2568 #define NET_IP_ALIGN 2
2572 * The networking layer reserves some headroom in skb data (via
2573 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2574 * the header has to grow. In the default case, if the header has to grow
2575 * 32 bytes or less we avoid the reallocation.
2577 * Unfortunately this headroom changes the DMA alignment of the resulting
2578 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2579 * on some architectures. An architecture can override this value,
2580 * perhaps setting it to a cacheline in size (since that will maintain
2581 * cacheline alignment of the DMA). It must be a power of 2.
2583 * Various parts of the networking layer expect at least 32 bytes of
2584 * headroom, you should not reduce this.
2586 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2587 * to reduce average number of cache lines per packet.
2588 * get_rps_cpus() for example only access one 64 bytes aligned block :
2589 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2592 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2595 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2597 static inline void __skb_set_length(struct sk_buff
*skb
, unsigned int len
)
2599 if (WARN_ON(skb_is_nonlinear(skb
)))
2602 skb_set_tail_pointer(skb
, len
);
2605 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2607 __skb_set_length(skb
, len
);
2610 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2612 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2615 return ___pskb_trim(skb
, len
);
2616 __skb_trim(skb
, len
);
2620 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2622 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2626 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2627 * @skb: buffer to alter
2630 * This is identical to pskb_trim except that the caller knows that
2631 * the skb is not cloned so we should never get an error due to out-
2634 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2636 int err
= pskb_trim(skb
, len
);
2640 static inline int __skb_grow(struct sk_buff
*skb
, unsigned int len
)
2642 unsigned int diff
= len
- skb
->len
;
2644 if (skb_tailroom(skb
) < diff
) {
2645 int ret
= pskb_expand_head(skb
, 0, diff
- skb_tailroom(skb
),
2650 __skb_set_length(skb
, len
);
2655 * skb_orphan - orphan a buffer
2656 * @skb: buffer to orphan
2658 * If a buffer currently has an owner then we call the owner's
2659 * destructor function and make the @skb unowned. The buffer continues
2660 * to exist but is no longer charged to its former owner.
2662 static inline void skb_orphan(struct sk_buff
*skb
)
2664 if (skb
->destructor
) {
2665 skb
->destructor(skb
);
2666 skb
->destructor
= NULL
;
2674 * skb_orphan_frags - orphan the frags contained in a buffer
2675 * @skb: buffer to orphan frags from
2676 * @gfp_mask: allocation mask for replacement pages
2678 * For each frag in the SKB which needs a destructor (i.e. has an
2679 * owner) create a copy of that frag and release the original
2680 * page by calling the destructor.
2682 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2684 if (likely(!skb_zcopy(skb
)))
2686 if (skb_uarg(skb
)->callback
== sock_zerocopy_callback
)
2688 return skb_copy_ubufs(skb
, gfp_mask
);
2691 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
2692 static inline int skb_orphan_frags_rx(struct sk_buff
*skb
, gfp_t gfp_mask
)
2694 if (likely(!skb_zcopy(skb
)))
2696 return skb_copy_ubufs(skb
, gfp_mask
);
2700 * __skb_queue_purge - empty a list
2701 * @list: list to empty
2703 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2704 * the list and one reference dropped. This function does not take the
2705 * list lock and the caller must hold the relevant locks to use it.
2707 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2709 struct sk_buff
*skb
;
2710 while ((skb
= __skb_dequeue(list
)) != NULL
)
2713 void skb_queue_purge(struct sk_buff_head
*list
);
2715 unsigned int skb_rbtree_purge(struct rb_root
*root
);
2717 void *netdev_alloc_frag(unsigned int fragsz
);
2719 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2723 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2724 * @dev: network device to receive on
2725 * @length: length to allocate
2727 * Allocate a new &sk_buff and assign it a usage count of one. The
2728 * buffer has unspecified headroom built in. Users should allocate
2729 * the headroom they think they need without accounting for the
2730 * built in space. The built in space is used for optimisations.
2732 * %NULL is returned if there is no free memory. Although this function
2733 * allocates memory it can be called from an interrupt.
2735 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2736 unsigned int length
)
2738 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2741 /* legacy helper around __netdev_alloc_skb() */
2742 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2745 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2748 /* legacy helper around netdev_alloc_skb() */
2749 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2751 return netdev_alloc_skb(NULL
, length
);
2755 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2756 unsigned int length
, gfp_t gfp
)
2758 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2760 if (NET_IP_ALIGN
&& skb
)
2761 skb_reserve(skb
, NET_IP_ALIGN
);
2765 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2766 unsigned int length
)
2768 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2771 static inline void skb_free_frag(void *addr
)
2773 page_frag_free(addr
);
2776 void *napi_alloc_frag(unsigned int fragsz
);
2777 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2778 unsigned int length
, gfp_t gfp_mask
);
2779 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2780 unsigned int length
)
2782 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2784 void napi_consume_skb(struct sk_buff
*skb
, int budget
);
2786 void __kfree_skb_flush(void);
2787 void __kfree_skb_defer(struct sk_buff
*skb
);
2790 * __dev_alloc_pages - allocate page for network Rx
2791 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2792 * @order: size of the allocation
2794 * Allocate a new page.
2796 * %NULL is returned if there is no free memory.
2798 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2801 /* This piece of code contains several assumptions.
2802 * 1. This is for device Rx, therefor a cold page is preferred.
2803 * 2. The expectation is the user wants a compound page.
2804 * 3. If requesting a order 0 page it will not be compound
2805 * due to the check to see if order has a value in prep_new_page
2806 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2807 * code in gfp_to_alloc_flags that should be enforcing this.
2809 gfp_mask
|= __GFP_COMP
| __GFP_MEMALLOC
;
2811 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2814 static inline struct page
*dev_alloc_pages(unsigned int order
)
2816 return __dev_alloc_pages(GFP_ATOMIC
| __GFP_NOWARN
, order
);
2820 * __dev_alloc_page - allocate a page for network Rx
2821 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2823 * Allocate a new page.
2825 * %NULL is returned if there is no free memory.
2827 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2829 return __dev_alloc_pages(gfp_mask
, 0);
2832 static inline struct page
*dev_alloc_page(void)
2834 return dev_alloc_pages(0);
2838 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2839 * @page: The page that was allocated from skb_alloc_page
2840 * @skb: The skb that may need pfmemalloc set
2842 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2843 struct sk_buff
*skb
)
2845 if (page_is_pfmemalloc(page
))
2846 skb
->pfmemalloc
= true;
2850 * skb_frag_page - retrieve the page referred to by a paged fragment
2851 * @frag: the paged fragment
2853 * Returns the &struct page associated with @frag.
2855 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2857 return frag
->page
.p
;
2861 * __skb_frag_ref - take an addition reference on a paged fragment.
2862 * @frag: the paged fragment
2864 * Takes an additional reference on the paged fragment @frag.
2866 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2868 get_page(skb_frag_page(frag
));
2872 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2874 * @f: the fragment offset.
2876 * Takes an additional reference on the @f'th paged fragment of @skb.
2878 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2880 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2884 * __skb_frag_unref - release a reference on a paged fragment.
2885 * @frag: the paged fragment
2887 * Releases a reference on the paged fragment @frag.
2889 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2891 put_page(skb_frag_page(frag
));
2895 * skb_frag_unref - release a reference on a paged fragment of an skb.
2897 * @f: the fragment offset
2899 * Releases a reference on the @f'th paged fragment of @skb.
2901 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2903 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2907 * skb_frag_address - gets the address of the data contained in a paged fragment
2908 * @frag: the paged fragment buffer
2910 * Returns the address of the data within @frag. The page must already
2913 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2915 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2919 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2920 * @frag: the paged fragment buffer
2922 * Returns the address of the data within @frag. Checks that the page
2923 * is mapped and returns %NULL otherwise.
2925 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2927 void *ptr
= page_address(skb_frag_page(frag
));
2931 return ptr
+ frag
->page_offset
;
2935 * __skb_frag_set_page - sets the page contained in a paged fragment
2936 * @frag: the paged fragment
2937 * @page: the page to set
2939 * Sets the fragment @frag to contain @page.
2941 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2943 frag
->page
.p
= page
;
2947 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2949 * @f: the fragment offset
2950 * @page: the page to set
2952 * Sets the @f'th fragment of @skb to contain @page.
2954 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2957 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2960 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2963 * skb_frag_dma_map - maps a paged fragment via the DMA API
2964 * @dev: the device to map the fragment to
2965 * @frag: the paged fragment to map
2966 * @offset: the offset within the fragment (starting at the
2967 * fragment's own offset)
2968 * @size: the number of bytes to map
2969 * @dir: the direction of the mapping (``PCI_DMA_*``)
2971 * Maps the page associated with @frag to @device.
2973 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2974 const skb_frag_t
*frag
,
2975 size_t offset
, size_t size
,
2976 enum dma_data_direction dir
)
2978 return dma_map_page(dev
, skb_frag_page(frag
),
2979 frag
->page_offset
+ offset
, size
, dir
);
2982 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2985 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2989 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2992 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2997 * skb_clone_writable - is the header of a clone writable
2998 * @skb: buffer to check
2999 * @len: length up to which to write
3001 * Returns true if modifying the header part of the cloned buffer
3002 * does not requires the data to be copied.
3004 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
3006 return !skb_header_cloned(skb
) &&
3007 skb_headroom(skb
) + len
<= skb
->hdr_len
;
3010 static inline int skb_try_make_writable(struct sk_buff
*skb
,
3011 unsigned int write_len
)
3013 return skb_cloned(skb
) && !skb_clone_writable(skb
, write_len
) &&
3014 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
3017 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
3022 if (headroom
> skb_headroom(skb
))
3023 delta
= headroom
- skb_headroom(skb
);
3025 if (delta
|| cloned
)
3026 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
3032 * skb_cow - copy header of skb when it is required
3033 * @skb: buffer to cow
3034 * @headroom: needed headroom
3036 * If the skb passed lacks sufficient headroom or its data part
3037 * is shared, data is reallocated. If reallocation fails, an error
3038 * is returned and original skb is not changed.
3040 * The result is skb with writable area skb->head...skb->tail
3041 * and at least @headroom of space at head.
3043 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
3045 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
3049 * skb_cow_head - skb_cow but only making the head writable
3050 * @skb: buffer to cow
3051 * @headroom: needed headroom
3053 * This function is identical to skb_cow except that we replace the
3054 * skb_cloned check by skb_header_cloned. It should be used when
3055 * you only need to push on some header and do not need to modify
3058 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
3060 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
3064 * skb_padto - pad an skbuff up to a minimal size
3065 * @skb: buffer to pad
3066 * @len: minimal length
3068 * Pads up a buffer to ensure the trailing bytes exist and are
3069 * blanked. If the buffer already contains sufficient data it
3070 * is untouched. Otherwise it is extended. Returns zero on
3071 * success. The skb is freed on error.
3073 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
3075 unsigned int size
= skb
->len
;
3076 if (likely(size
>= len
))
3078 return skb_pad(skb
, len
- size
);
3082 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3083 * @skb: buffer to pad
3084 * @len: minimal length
3085 * @free_on_error: free buffer on error
3087 * Pads up a buffer to ensure the trailing bytes exist and are
3088 * blanked. If the buffer already contains sufficient data it
3089 * is untouched. Otherwise it is extended. Returns zero on
3090 * success. The skb is freed on error if @free_on_error is true.
3092 static inline int __skb_put_padto(struct sk_buff
*skb
, unsigned int len
,
3095 unsigned int size
= skb
->len
;
3097 if (unlikely(size
< len
)) {
3099 if (__skb_pad(skb
, len
, free_on_error
))
3101 __skb_put(skb
, len
);
3107 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3108 * @skb: buffer to pad
3109 * @len: minimal length
3111 * Pads up a buffer to ensure the trailing bytes exist and are
3112 * blanked. If the buffer already contains sufficient data it
3113 * is untouched. Otherwise it is extended. Returns zero on
3114 * success. The skb is freed on error.
3116 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
3118 return __skb_put_padto(skb
, len
, true);
3121 static inline int skb_add_data(struct sk_buff
*skb
,
3122 struct iov_iter
*from
, int copy
)
3124 const int off
= skb
->len
;
3126 if (skb
->ip_summed
== CHECKSUM_NONE
) {
3128 if (csum_and_copy_from_iter_full(skb_put(skb
, copy
), copy
,
3130 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
3133 } else if (copy_from_iter_full(skb_put(skb
, copy
), copy
, from
))
3136 __skb_trim(skb
, off
);
3140 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
3141 const struct page
*page
, int off
)
3146 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
3148 return page
== skb_frag_page(frag
) &&
3149 off
== frag
->page_offset
+ skb_frag_size(frag
);
3154 static inline int __skb_linearize(struct sk_buff
*skb
)
3156 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
3160 * skb_linearize - convert paged skb to linear one
3161 * @skb: buffer to linarize
3163 * If there is no free memory -ENOMEM is returned, otherwise zero
3164 * is returned and the old skb data released.
3166 static inline int skb_linearize(struct sk_buff
*skb
)
3168 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
3172 * skb_has_shared_frag - can any frag be overwritten
3173 * @skb: buffer to test
3175 * Return true if the skb has at least one frag that might be modified
3176 * by an external entity (as in vmsplice()/sendfile())
3178 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
3180 return skb_is_nonlinear(skb
) &&
3181 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
3185 * skb_linearize_cow - make sure skb is linear and writable
3186 * @skb: buffer to process
3188 * If there is no free memory -ENOMEM is returned, otherwise zero
3189 * is returned and the old skb data released.
3191 static inline int skb_linearize_cow(struct sk_buff
*skb
)
3193 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
3194 __skb_linearize(skb
) : 0;
3197 static __always_inline
void
3198 __skb_postpull_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
3201 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3202 skb
->csum
= csum_block_sub(skb
->csum
,
3203 csum_partial(start
, len
, 0), off
);
3204 else if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3205 skb_checksum_start_offset(skb
) < 0)
3206 skb
->ip_summed
= CHECKSUM_NONE
;
3210 * skb_postpull_rcsum - update checksum for received skb after pull
3211 * @skb: buffer to update
3212 * @start: start of data before pull
3213 * @len: length of data pulled
3215 * After doing a pull on a received packet, you need to call this to
3216 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3217 * CHECKSUM_NONE so that it can be recomputed from scratch.
3219 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
3220 const void *start
, unsigned int len
)
3222 __skb_postpull_rcsum(skb
, start
, len
, 0);
3225 static __always_inline
void
3226 __skb_postpush_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
3229 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3230 skb
->csum
= csum_block_add(skb
->csum
,
3231 csum_partial(start
, len
, 0), off
);
3235 * skb_postpush_rcsum - update checksum for received skb after push
3236 * @skb: buffer to update
3237 * @start: start of data after push
3238 * @len: length of data pushed
3240 * After doing a push on a received packet, you need to call this to
3241 * update the CHECKSUM_COMPLETE checksum.
3243 static inline void skb_postpush_rcsum(struct sk_buff
*skb
,
3244 const void *start
, unsigned int len
)
3246 __skb_postpush_rcsum(skb
, start
, len
, 0);
3249 void *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
3252 * skb_push_rcsum - push skb and update receive checksum
3253 * @skb: buffer to update
3254 * @len: length of data pulled
3256 * This function performs an skb_push on the packet and updates
3257 * the CHECKSUM_COMPLETE checksum. It should be used on
3258 * receive path processing instead of skb_push unless you know
3259 * that the checksum difference is zero (e.g., a valid IP header)
3260 * or you are setting ip_summed to CHECKSUM_NONE.
3262 static inline void *skb_push_rcsum(struct sk_buff
*skb
, unsigned int len
)
3265 skb_postpush_rcsum(skb
, skb
->data
, len
);
3269 int pskb_trim_rcsum_slow(struct sk_buff
*skb
, unsigned int len
);
3271 * pskb_trim_rcsum - trim received skb and update checksum
3272 * @skb: buffer to trim
3275 * This is exactly the same as pskb_trim except that it ensures the
3276 * checksum of received packets are still valid after the operation.
3277 * It can change skb pointers.
3280 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3282 if (likely(len
>= skb
->len
))
3284 return pskb_trim_rcsum_slow(skb
, len
);
3287 static inline int __skb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3289 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3290 skb
->ip_summed
= CHECKSUM_NONE
;
3291 __skb_trim(skb
, len
);
3295 static inline int __skb_grow_rcsum(struct sk_buff
*skb
, unsigned int len
)
3297 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3298 skb
->ip_summed
= CHECKSUM_NONE
;
3299 return __skb_grow(skb
, len
);
3302 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3303 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3304 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3305 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3306 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3308 #define skb_queue_walk(queue, skb) \
3309 for (skb = (queue)->next; \
3310 skb != (struct sk_buff *)(queue); \
3313 #define skb_queue_walk_safe(queue, skb, tmp) \
3314 for (skb = (queue)->next, tmp = skb->next; \
3315 skb != (struct sk_buff *)(queue); \
3316 skb = tmp, tmp = skb->next)
3318 #define skb_queue_walk_from(queue, skb) \
3319 for (; skb != (struct sk_buff *)(queue); \
3322 #define skb_rbtree_walk(skb, root) \
3323 for (skb = skb_rb_first(root); skb != NULL; \
3324 skb = skb_rb_next(skb))
3326 #define skb_rbtree_walk_from(skb) \
3327 for (; skb != NULL; \
3328 skb = skb_rb_next(skb))
3330 #define skb_rbtree_walk_from_safe(skb, tmp) \
3331 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3334 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3335 for (tmp = skb->next; \
3336 skb != (struct sk_buff *)(queue); \
3337 skb = tmp, tmp = skb->next)
3339 #define skb_queue_reverse_walk(queue, skb) \
3340 for (skb = (queue)->prev; \
3341 skb != (struct sk_buff *)(queue); \
3344 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3345 for (skb = (queue)->prev, tmp = skb->prev; \
3346 skb != (struct sk_buff *)(queue); \
3347 skb = tmp, tmp = skb->prev)
3349 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3350 for (tmp = skb->prev; \
3351 skb != (struct sk_buff *)(queue); \
3352 skb = tmp, tmp = skb->prev)
3354 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
3356 return skb_shinfo(skb
)->frag_list
!= NULL
;
3359 static inline void skb_frag_list_init(struct sk_buff
*skb
)
3361 skb_shinfo(skb
)->frag_list
= NULL
;
3364 #define skb_walk_frags(skb, iter) \
3365 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3368 int __skb_wait_for_more_packets(struct sock
*sk
, int *err
, long *timeo_p
,
3369 const struct sk_buff
*skb
);
3370 struct sk_buff
*__skb_try_recv_from_queue(struct sock
*sk
,
3371 struct sk_buff_head
*queue
,
3373 void (*destructor
)(struct sock
*sk
,
3374 struct sk_buff
*skb
),
3375 int *peeked
, int *off
, int *err
,
3376 struct sk_buff
**last
);
3377 struct sk_buff
*__skb_try_recv_datagram(struct sock
*sk
, unsigned flags
,
3378 void (*destructor
)(struct sock
*sk
,
3379 struct sk_buff
*skb
),
3380 int *peeked
, int *off
, int *err
,
3381 struct sk_buff
**last
);
3382 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
3383 void (*destructor
)(struct sock
*sk
,
3384 struct sk_buff
*skb
),
3385 int *peeked
, int *off
, int *err
);
3386 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
3388 __poll_t
datagram_poll(struct file
*file
, struct socket
*sock
,
3389 struct poll_table_struct
*wait
);
3390 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
3391 struct iov_iter
*to
, int size
);
3392 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
3393 struct msghdr
*msg
, int size
)
3395 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
3397 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
3398 struct msghdr
*msg
);
3399 int skb_copy_and_hash_datagram_iter(const struct sk_buff
*skb
, int offset
,
3400 struct iov_iter
*to
, int len
,
3401 struct ahash_request
*hash
);
3402 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
3403 struct iov_iter
*from
, int len
);
3404 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
3405 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
3406 void __skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
, int len
);
3407 static inline void skb_free_datagram_locked(struct sock
*sk
,
3408 struct sk_buff
*skb
)
3410 __skb_free_datagram_locked(sk
, skb
, 0);
3412 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
3413 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
3414 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
3415 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
3416 int len
, __wsum csum
);
3417 int skb_splice_bits(struct sk_buff
*skb
, struct sock
*sk
, unsigned int offset
,
3418 struct pipe_inode_info
*pipe
, unsigned int len
,
3419 unsigned int flags
);
3420 int skb_send_sock_locked(struct sock
*sk
, struct sk_buff
*skb
, int offset
,
3422 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
3423 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
3424 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
3426 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
3427 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
3428 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
3429 bool skb_gso_validate_network_len(const struct sk_buff
*skb
, unsigned int mtu
);
3430 bool skb_gso_validate_mac_len(const struct sk_buff
*skb
, unsigned int len
);
3431 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
3432 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
3433 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
3434 int __skb_vlan_pop(struct sk_buff
*skb
, u16
*vlan_tci
);
3435 int skb_vlan_pop(struct sk_buff
*skb
);
3436 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
3437 struct sk_buff
*pskb_extract(struct sk_buff
*skb
, int off
, int to_copy
,
3440 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
3442 return copy_from_iter_full(data
, len
, &msg
->msg_iter
) ? 0 : -EFAULT
;
3445 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
3447 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3450 struct skb_checksum_ops
{
3451 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
3452 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
3455 extern const struct skb_checksum_ops
*crc32c_csum_stub __read_mostly
;
3457 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3458 __wsum csum
, const struct skb_checksum_ops
*ops
);
3459 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3462 static inline void * __must_check
3463 __skb_header_pointer(const struct sk_buff
*skb
, int offset
,
3464 int len
, void *data
, int hlen
, void *buffer
)
3466 if (hlen
- offset
>= len
)
3467 return data
+ offset
;
3470 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
3476 static inline void * __must_check
3477 skb_header_pointer(const struct sk_buff
*skb
, int offset
, int len
, void *buffer
)
3479 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
3480 skb_headlen(skb
), buffer
);
3484 * skb_needs_linearize - check if we need to linearize a given skb
3485 * depending on the given device features.
3486 * @skb: socket buffer to check
3487 * @features: net device features
3489 * Returns true if either:
3490 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3491 * 2. skb is fragmented and the device does not support SG.
3493 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
3494 netdev_features_t features
)
3496 return skb_is_nonlinear(skb
) &&
3497 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
3498 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
3501 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
3503 const unsigned int len
)
3505 memcpy(to
, skb
->data
, len
);
3508 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
3509 const int offset
, void *to
,
3510 const unsigned int len
)
3512 memcpy(to
, skb
->data
+ offset
, len
);
3515 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
3517 const unsigned int len
)
3519 memcpy(skb
->data
, from
, len
);
3522 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
3525 const unsigned int len
)
3527 memcpy(skb
->data
+ offset
, from
, len
);
3530 void skb_init(void);
3532 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
3538 * skb_get_timestamp - get timestamp from a skb
3539 * @skb: skb to get stamp from
3540 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
3542 * Timestamps are stored in the skb as offsets to a base timestamp.
3543 * This function converts the offset back to a struct timeval and stores
3546 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
3547 struct __kernel_old_timeval
*stamp
)
3549 *stamp
= ns_to_kernel_old_timeval(skb
->tstamp
);
3552 static inline void skb_get_new_timestamp(const struct sk_buff
*skb
,
3553 struct __kernel_sock_timeval
*stamp
)
3555 struct timespec64 ts
= ktime_to_timespec64(skb
->tstamp
);
3557 stamp
->tv_sec
= ts
.tv_sec
;
3558 stamp
->tv_usec
= ts
.tv_nsec
/ 1000;
3561 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
3562 struct timespec
*stamp
)
3564 *stamp
= ktime_to_timespec(skb
->tstamp
);
3567 static inline void skb_get_new_timestampns(const struct sk_buff
*skb
,
3568 struct __kernel_timespec
*stamp
)
3570 struct timespec64 ts
= ktime_to_timespec64(skb
->tstamp
);
3572 stamp
->tv_sec
= ts
.tv_sec
;
3573 stamp
->tv_nsec
= ts
.tv_nsec
;
3576 static inline void __net_timestamp(struct sk_buff
*skb
)
3578 skb
->tstamp
= ktime_get_real();
3581 static inline ktime_t
net_timedelta(ktime_t t
)
3583 return ktime_sub(ktime_get_real(), t
);
3586 static inline ktime_t
net_invalid_timestamp(void)
3591 static inline u8
skb_metadata_len(const struct sk_buff
*skb
)
3593 return skb_shinfo(skb
)->meta_len
;
3596 static inline void *skb_metadata_end(const struct sk_buff
*skb
)
3598 return skb_mac_header(skb
);
3601 static inline bool __skb_metadata_differs(const struct sk_buff
*skb_a
,
3602 const struct sk_buff
*skb_b
,
3605 const void *a
= skb_metadata_end(skb_a
);
3606 const void *b
= skb_metadata_end(skb_b
);
3607 /* Using more efficient varaiant than plain call to memcmp(). */
3608 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
3612 #define __it(x, op) (x -= sizeof(u##op))
3613 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
3614 case 32: diffs
|= __it_diff(a
, b
, 64);
3616 case 24: diffs
|= __it_diff(a
, b
, 64);
3618 case 16: diffs
|= __it_diff(a
, b
, 64);
3620 case 8: diffs
|= __it_diff(a
, b
, 64);
3622 case 28: diffs
|= __it_diff(a
, b
, 64);
3624 case 20: diffs
|= __it_diff(a
, b
, 64);
3626 case 12: diffs
|= __it_diff(a
, b
, 64);
3628 case 4: diffs
|= __it_diff(a
, b
, 32);
3633 return memcmp(a
- meta_len
, b
- meta_len
, meta_len
);
3637 static inline bool skb_metadata_differs(const struct sk_buff
*skb_a
,
3638 const struct sk_buff
*skb_b
)
3640 u8 len_a
= skb_metadata_len(skb_a
);
3641 u8 len_b
= skb_metadata_len(skb_b
);
3643 if (!(len_a
| len_b
))
3646 return len_a
!= len_b
?
3647 true : __skb_metadata_differs(skb_a
, skb_b
, len_a
);
3650 static inline void skb_metadata_set(struct sk_buff
*skb
, u8 meta_len
)
3652 skb_shinfo(skb
)->meta_len
= meta_len
;
3655 static inline void skb_metadata_clear(struct sk_buff
*skb
)
3657 skb_metadata_set(skb
, 0);
3660 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
3662 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3664 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
3665 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
3667 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3669 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
3673 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
3678 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3681 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3683 * PHY drivers may accept clones of transmitted packets for
3684 * timestamping via their phy_driver.txtstamp method. These drivers
3685 * must call this function to return the skb back to the stack with a
3688 * @skb: clone of the the original outgoing packet
3689 * @hwtstamps: hardware time stamps
3692 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
3693 struct skb_shared_hwtstamps
*hwtstamps
);
3695 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
3696 struct skb_shared_hwtstamps
*hwtstamps
,
3697 struct sock
*sk
, int tstype
);
3700 * skb_tstamp_tx - queue clone of skb with send time stamps
3701 * @orig_skb: the original outgoing packet
3702 * @hwtstamps: hardware time stamps, may be NULL if not available
3704 * If the skb has a socket associated, then this function clones the
3705 * skb (thus sharing the actual data and optional structures), stores
3706 * the optional hardware time stamping information (if non NULL) or
3707 * generates a software time stamp (otherwise), then queues the clone
3708 * to the error queue of the socket. Errors are silently ignored.
3710 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
3711 struct skb_shared_hwtstamps
*hwtstamps
);
3714 * skb_tx_timestamp() - Driver hook for transmit timestamping
3716 * Ethernet MAC Drivers should call this function in their hard_xmit()
3717 * function immediately before giving the sk_buff to the MAC hardware.
3719 * Specifically, one should make absolutely sure that this function is
3720 * called before TX completion of this packet can trigger. Otherwise
3721 * the packet could potentially already be freed.
3723 * @skb: A socket buffer.
3725 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
3727 skb_clone_tx_timestamp(skb
);
3728 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
)
3729 skb_tstamp_tx(skb
, NULL
);
3733 * skb_complete_wifi_ack - deliver skb with wifi status
3735 * @skb: the original outgoing packet
3736 * @acked: ack status
3739 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
3741 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
3742 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
3744 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
3746 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
3748 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3749 skb_checksum_start_offset(skb
) >= 0));
3753 * skb_checksum_complete - Calculate checksum of an entire packet
3754 * @skb: packet to process
3756 * This function calculates the checksum over the entire packet plus
3757 * the value of skb->csum. The latter can be used to supply the
3758 * checksum of a pseudo header as used by TCP/UDP. It returns the
3761 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3762 * this function can be used to verify that checksum on received
3763 * packets. In that case the function should return zero if the
3764 * checksum is correct. In particular, this function will return zero
3765 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3766 * hardware has already verified the correctness of the checksum.
3768 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
3770 return skb_csum_unnecessary(skb
) ?
3771 0 : __skb_checksum_complete(skb
);
3774 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
3776 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3777 if (skb
->csum_level
== 0)
3778 skb
->ip_summed
= CHECKSUM_NONE
;
3784 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
3786 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3787 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
3789 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
3790 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
3791 skb
->csum_level
= 0;
3795 /* Check if we need to perform checksum complete validation.
3797 * Returns true if checksum complete is needed, false otherwise
3798 * (either checksum is unnecessary or zero checksum is allowed).
3800 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3804 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3805 skb
->csum_valid
= 1;
3806 __skb_decr_checksum_unnecessary(skb
);
3813 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
3816 #define CHECKSUM_BREAK 76
3818 /* Unset checksum-complete
3820 * Unset checksum complete can be done when packet is being modified
3821 * (uncompressed for instance) and checksum-complete value is
3824 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3826 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3827 skb
->ip_summed
= CHECKSUM_NONE
;
3830 /* Validate (init) checksum based on checksum complete.
3833 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3834 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3835 * checksum is stored in skb->csum for use in __skb_checksum_complete
3836 * non-zero: value of invalid checksum
3839 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3843 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3844 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3845 skb
->csum_valid
= 1;
3852 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3855 csum
= __skb_checksum_complete(skb
);
3856 skb
->csum_valid
= !csum
;
3863 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3868 /* Perform checksum validate (init). Note that this is a macro since we only
3869 * want to calculate the pseudo header which is an input function if necessary.
3870 * First we try to validate without any computation (checksum unnecessary) and
3871 * then calculate based on checksum complete calling the function to compute
3875 * 0: checksum is validated or try to in skb_checksum_complete
3876 * non-zero: value of invalid checksum
3878 #define __skb_checksum_validate(skb, proto, complete, \
3879 zero_okay, check, compute_pseudo) \
3881 __sum16 __ret = 0; \
3882 skb->csum_valid = 0; \
3883 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3884 __ret = __skb_checksum_validate_complete(skb, \
3885 complete, compute_pseudo(skb, proto)); \
3889 #define skb_checksum_init(skb, proto, compute_pseudo) \
3890 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3892 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3893 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3895 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3896 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3898 #define skb_checksum_validate_zero_check(skb, proto, check, \
3900 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3902 #define skb_checksum_simple_validate(skb) \
3903 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3905 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3907 return (skb
->ip_summed
== CHECKSUM_NONE
&& skb
->csum_valid
);
3910 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3911 __sum16 check
, __wsum pseudo
)
3913 skb
->csum
= ~pseudo
;
3914 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3917 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3919 if (__skb_checksum_convert_check(skb)) \
3920 __skb_checksum_convert(skb, check, \
3921 compute_pseudo(skb, proto)); \
3924 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3925 u16 start
, u16 offset
)
3927 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3928 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3929 skb
->csum_offset
= offset
- start
;
3932 /* Update skbuf and packet to reflect the remote checksum offload operation.
3933 * When called, ptr indicates the starting point for skb->csum when
3934 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3935 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3937 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3938 int start
, int offset
, bool nopartial
)
3943 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3947 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3948 __skb_checksum_complete(skb
);
3949 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3952 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3954 /* Adjust skb->csum since we changed the packet */
3955 skb
->csum
= csum_add(skb
->csum
, delta
);
3958 static inline struct nf_conntrack
*skb_nfct(const struct sk_buff
*skb
)
3960 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3961 return (void *)(skb
->_nfct
& SKB_NFCT_PTRMASK
);
3967 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3968 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3969 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3971 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3972 nf_conntrack_destroy(nfct
);
3974 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3977 atomic_inc(&nfct
->use
);
3981 #ifdef CONFIG_SKB_EXTENSIONS
3983 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3989 SKB_EXT_NUM
, /* must be last */
3993 * struct skb_ext - sk_buff extensions
3994 * @refcnt: 1 on allocation, deallocated on 0
3995 * @offset: offset to add to @data to obtain extension address
3996 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
3997 * @data: start of extension data, variable sized
3999 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4000 * to use 'u8' types while allowing up to 2kb worth of extension data.
4004 u8 offset
[SKB_EXT_NUM
]; /* in chunks of 8 bytes */
4005 u8 chunks
; /* same */
4006 char data
[0] __aligned(8);
4009 void *skb_ext_add(struct sk_buff
*skb
, enum skb_ext_id id
);
4010 void __skb_ext_del(struct sk_buff
*skb
, enum skb_ext_id id
);
4011 void __skb_ext_put(struct skb_ext
*ext
);
4013 static inline void skb_ext_put(struct sk_buff
*skb
)
4015 if (skb
->active_extensions
)
4016 __skb_ext_put(skb
->extensions
);
4019 static inline void __skb_ext_copy(struct sk_buff
*dst
,
4020 const struct sk_buff
*src
)
4022 dst
->active_extensions
= src
->active_extensions
;
4024 if (src
->active_extensions
) {
4025 struct skb_ext
*ext
= src
->extensions
;
4027 refcount_inc(&ext
->refcnt
);
4028 dst
->extensions
= ext
;
4032 static inline void skb_ext_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
4035 __skb_ext_copy(dst
, src
);
4038 static inline bool __skb_ext_exist(const struct skb_ext
*ext
, enum skb_ext_id i
)
4040 return !!ext
->offset
[i
];
4043 static inline bool skb_ext_exist(const struct sk_buff
*skb
, enum skb_ext_id id
)
4045 return skb
->active_extensions
& (1 << id
);
4048 static inline void skb_ext_del(struct sk_buff
*skb
, enum skb_ext_id id
)
4050 if (skb_ext_exist(skb
, id
))
4051 __skb_ext_del(skb
, id
);
4054 static inline void *skb_ext_find(const struct sk_buff
*skb
, enum skb_ext_id id
)
4056 if (skb_ext_exist(skb
, id
)) {
4057 struct skb_ext
*ext
= skb
->extensions
;
4059 return (void *)ext
+ (ext
->offset
[id
] << 3);
4065 static inline void skb_ext_put(struct sk_buff
*skb
) {}
4066 static inline void skb_ext_del(struct sk_buff
*skb
, int unused
) {}
4067 static inline void __skb_ext_copy(struct sk_buff
*d
, const struct sk_buff
*s
) {}
4068 static inline void skb_ext_copy(struct sk_buff
*dst
, const struct sk_buff
*s
) {}
4069 #endif /* CONFIG_SKB_EXTENSIONS */
4071 static inline void nf_reset(struct sk_buff
*skb
)
4073 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4074 nf_conntrack_put(skb_nfct(skb
));
4077 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4078 skb_ext_del(skb
, SKB_EXT_BRIDGE_NF
);
4082 static inline void nf_reset_trace(struct sk_buff
*skb
)
4084 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4089 static inline void ipvs_reset(struct sk_buff
*skb
)
4091 #if IS_ENABLED(CONFIG_IP_VS)
4092 skb
->ipvs_property
= 0;
4096 /* Note: This doesn't put any conntrack info in dst. */
4097 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
4100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4101 dst
->_nfct
= src
->_nfct
;
4102 nf_conntrack_get(skb_nfct(src
));
4104 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4106 dst
->nf_trace
= src
->nf_trace
;
4110 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
4112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4113 nf_conntrack_put(skb_nfct(dst
));
4115 __nf_copy(dst
, src
, true);
4118 #ifdef CONFIG_NETWORK_SECMARK
4119 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
4121 to
->secmark
= from
->secmark
;
4124 static inline void skb_init_secmark(struct sk_buff
*skb
)
4129 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
4132 static inline void skb_init_secmark(struct sk_buff
*skb
)
4136 static inline int secpath_exists(const struct sk_buff
*skb
)
4139 return skb_ext_exist(skb
, SKB_EXT_SEC_PATH
);
4145 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
4147 return !skb
->destructor
&&
4148 !secpath_exists(skb
) &&
4150 !skb
->_skb_refdst
&&
4151 !skb_has_frag_list(skb
);
4154 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
4156 skb
->queue_mapping
= queue_mapping
;
4159 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
4161 return skb
->queue_mapping
;
4164 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
4166 to
->queue_mapping
= from
->queue_mapping
;
4169 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
4171 skb
->queue_mapping
= rx_queue
+ 1;
4174 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
4176 return skb
->queue_mapping
- 1;
4179 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
4181 return skb
->queue_mapping
!= 0;
4184 static inline void skb_set_dst_pending_confirm(struct sk_buff
*skb
, u32 val
)
4186 skb
->dst_pending_confirm
= val
;
4189 static inline bool skb_get_dst_pending_confirm(const struct sk_buff
*skb
)
4191 return skb
->dst_pending_confirm
!= 0;
4194 static inline struct sec_path
*skb_sec_path(const struct sk_buff
*skb
)
4197 return skb_ext_find(skb
, SKB_EXT_SEC_PATH
);
4203 /* Keeps track of mac header offset relative to skb->head.
4204 * It is useful for TSO of Tunneling protocol. e.g. GRE.
4205 * For non-tunnel skb it points to skb_mac_header() and for
4206 * tunnel skb it points to outer mac header.
4207 * Keeps track of level of encapsulation of network headers.
4218 #define SKB_SGO_CB_OFFSET 32
4219 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
4221 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
4223 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
4224 SKB_GSO_CB(inner_skb
)->mac_offset
;
4227 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
4229 int new_headroom
, headroom
;
4232 headroom
= skb_headroom(skb
);
4233 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
4237 new_headroom
= skb_headroom(skb
);
4238 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
4242 static inline void gso_reset_checksum(struct sk_buff
*skb
, __wsum res
)
4244 /* Do not update partial checksums if remote checksum is enabled. */
4245 if (skb
->remcsum_offload
)
4248 SKB_GSO_CB(skb
)->csum
= res
;
4249 SKB_GSO_CB(skb
)->csum_start
= skb_checksum_start(skb
) - skb
->head
;
4252 /* Compute the checksum for a gso segment. First compute the checksum value
4253 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
4254 * then add in skb->csum (checksum from csum_start to end of packet).
4255 * skb->csum and csum_start are then updated to reflect the checksum of the
4256 * resultant packet starting from the transport header-- the resultant checksum
4257 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
4260 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
4262 unsigned char *csum_start
= skb_transport_header(skb
);
4263 int plen
= (skb
->head
+ SKB_GSO_CB(skb
)->csum_start
) - csum_start
;
4264 __wsum partial
= SKB_GSO_CB(skb
)->csum
;
4266 SKB_GSO_CB(skb
)->csum
= res
;
4267 SKB_GSO_CB(skb
)->csum_start
= csum_start
- skb
->head
;
4269 return csum_fold(csum_partial(csum_start
, plen
, partial
));
4272 static inline bool skb_is_gso(const struct sk_buff
*skb
)
4274 return skb_shinfo(skb
)->gso_size
;
4277 /* Note: Should be called only if skb_is_gso(skb) is true */
4278 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
4280 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
4283 /* Note: Should be called only if skb_is_gso(skb) is true */
4284 static inline bool skb_is_gso_sctp(const struct sk_buff
*skb
)
4286 return skb_shinfo(skb
)->gso_type
& SKB_GSO_SCTP
;
4289 /* Note: Should be called only if skb_is_gso(skb) is true */
4290 static inline bool skb_is_gso_tcp(const struct sk_buff
*skb
)
4292 return skb_shinfo(skb
)->gso_type
& (SKB_GSO_TCPV4
| SKB_GSO_TCPV6
);
4295 static inline void skb_gso_reset(struct sk_buff
*skb
)
4297 skb_shinfo(skb
)->gso_size
= 0;
4298 skb_shinfo(skb
)->gso_segs
= 0;
4299 skb_shinfo(skb
)->gso_type
= 0;
4302 static inline void skb_increase_gso_size(struct skb_shared_info
*shinfo
,
4305 if (WARN_ON_ONCE(shinfo
->gso_size
== GSO_BY_FRAGS
))
4307 shinfo
->gso_size
+= increment
;
4310 static inline void skb_decrease_gso_size(struct skb_shared_info
*shinfo
,
4313 if (WARN_ON_ONCE(shinfo
->gso_size
== GSO_BY_FRAGS
))
4315 shinfo
->gso_size
-= decrement
;
4318 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
4320 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
4322 /* LRO sets gso_size but not gso_type, whereas if GSO is really
4323 * wanted then gso_type will be set. */
4324 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
4326 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
4327 unlikely(shinfo
->gso_type
== 0)) {
4328 __skb_warn_lro_forwarding(skb
);
4334 static inline void skb_forward_csum(struct sk_buff
*skb
)
4336 /* Unfortunately we don't support this one. Any brave souls? */
4337 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
4338 skb
->ip_summed
= CHECKSUM_NONE
;
4342 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4343 * @skb: skb to check
4345 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4346 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4347 * use this helper, to document places where we make this assertion.
4349 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
4352 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
4356 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
4358 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
4359 struct sk_buff
*skb_checksum_trimmed(struct sk_buff
*skb
,
4360 unsigned int transport_len
,
4361 __sum16(*skb_chkf
)(struct sk_buff
*skb
));
4364 * skb_head_is_locked - Determine if the skb->head is locked down
4365 * @skb: skb to check
4367 * The head on skbs build around a head frag can be removed if they are
4368 * not cloned. This function returns true if the skb head is locked down
4369 * due to either being allocated via kmalloc, or by being a clone with
4370 * multiple references to the head.
4372 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
4374 return !skb
->head_frag
|| skb_cloned(skb
);
4377 /* Local Checksum Offload.
4378 * Compute outer checksum based on the assumption that the
4379 * inner checksum will be offloaded later.
4380 * See Documentation/networking/checksum-offloads.rst for
4381 * explanation of how this works.
4382 * Fill in outer checksum adjustment (e.g. with sum of outer
4383 * pseudo-header) before calling.
4384 * Also ensure that inner checksum is in linear data area.
4386 static inline __wsum
lco_csum(struct sk_buff
*skb
)
4388 unsigned char *csum_start
= skb_checksum_start(skb
);
4389 unsigned char *l4_hdr
= skb_transport_header(skb
);
4392 /* Start with complement of inner checksum adjustment */
4393 partial
= ~csum_unfold(*(__force __sum16
*)(csum_start
+
4396 /* Add in checksum of our headers (incl. outer checksum
4397 * adjustment filled in by caller) and return result.
4399 return csum_partial(l4_hdr
, csum_start
- l4_hdr
, partial
);
4402 #endif /* __KERNEL__ */
4403 #endif /* _LINUX_SKBUFF_H */