2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
23 #include <linux/rbtree.h>
24 #include <linux/socket.h>
25 #include <linux/refcount.h>
27 #include <linux/atomic.h>
28 #include <asm/types.h>
29 #include <linux/spinlock.h>
30 #include <linux/net.h>
31 #include <linux/textsearch.h>
32 #include <net/checksum.h>
33 #include <linux/rcupdate.h>
34 #include <linux/hrtimer.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/netdev_features.h>
37 #include <linux/sched.h>
38 #include <linux/sched/clock.h>
39 #include <net/flow_dissector.h>
40 #include <linux/splice.h>
41 #include <linux/in6.h>
42 #include <linux/if_packet.h>
45 /* The interface for checksum offload between the stack and networking drivers
48 * A. IP checksum related features
50 * Drivers advertise checksum offload capabilities in the features of a device.
51 * From the stack's point of view these are capabilities offered by the driver,
52 * a driver typically only advertises features that it is capable of offloading
55 * The checksum related features are:
57 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
58 * IP (one's complement) checksum for any combination
59 * of protocols or protocol layering. The checksum is
60 * computed and set in a packet per the CHECKSUM_PARTIAL
61 * interface (see below).
63 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
64 * TCP or UDP packets over IPv4. These are specifically
65 * unencapsulated packets of the form IPv4|TCP or
66 * IPv4|UDP where the Protocol field in the IPv4 header
67 * is TCP or UDP. The IPv4 header may contain IP options
68 * This feature cannot be set in features for a device
69 * with NETIF_F_HW_CSUM also set. This feature is being
70 * DEPRECATED (see below).
72 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
73 * TCP or UDP packets over IPv6. These are specifically
74 * unencapsulated packets of the form IPv6|TCP or
75 * IPv4|UDP where the Next Header field in the IPv6
76 * header is either TCP or UDP. IPv6 extension headers
77 * are not supported with this feature. This feature
78 * cannot be set in features for a device with
79 * NETIF_F_HW_CSUM also set. This feature is being
80 * DEPRECATED (see below).
82 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
83 * This flag is used only used to disable the RX checksum
84 * feature for a device. The stack will accept receive
85 * checksum indication in packets received on a device
86 * regardless of whether NETIF_F_RXCSUM is set.
88 * B. Checksumming of received packets by device. Indication of checksum
89 * verification is in set skb->ip_summed. Possible values are:
93 * Device did not checksum this packet e.g. due to lack of capabilities.
94 * The packet contains full (though not verified) checksum in packet but
95 * not in skb->csum. Thus, skb->csum is undefined in this case.
97 * CHECKSUM_UNNECESSARY:
99 * The hardware you're dealing with doesn't calculate the full checksum
100 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
101 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
102 * if their checksums are okay. skb->csum is still undefined in this case
103 * though. A driver or device must never modify the checksum field in the
104 * packet even if checksum is verified.
106 * CHECKSUM_UNNECESSARY is applicable to following protocols:
107 * TCP: IPv6 and IPv4.
108 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
109 * zero UDP checksum for either IPv4 or IPv6, the networking stack
110 * may perform further validation in this case.
111 * GRE: only if the checksum is present in the header.
112 * SCTP: indicates the CRC in SCTP header has been validated.
113 * FCOE: indicates the CRC in FC frame has been validated.
115 * skb->csum_level indicates the number of consecutive checksums found in
116 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
117 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
118 * and a device is able to verify the checksums for UDP (possibly zero),
119 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
120 * two. If the device were only able to verify the UDP checksum and not
121 * GRE, either because it doesn't support GRE checksum of because GRE
122 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
123 * not considered in this case).
127 * This is the most generic way. The device supplied checksum of the _whole_
128 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
129 * hardware doesn't need to parse L3/L4 headers to implement this.
132 * - Even if device supports only some protocols, but is able to produce
133 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
134 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
138 * A checksum is set up to be offloaded to a device as described in the
139 * output description for CHECKSUM_PARTIAL. This may occur on a packet
140 * received directly from another Linux OS, e.g., a virtualized Linux kernel
141 * on the same host, or it may be set in the input path in GRO or remote
142 * checksum offload. For the purposes of checksum verification, the checksum
143 * referred to by skb->csum_start + skb->csum_offset and any preceding
144 * checksums in the packet are considered verified. Any checksums in the
145 * packet that are after the checksum being offloaded are not considered to
148 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
149 * in the skb->ip_summed for a packet. Values are:
153 * The driver is required to checksum the packet as seen by hard_start_xmit()
154 * from skb->csum_start up to the end, and to record/write the checksum at
155 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
156 * csum_start and csum_offset values are valid values given the length and
157 * offset of the packet, however they should not attempt to validate that the
158 * checksum refers to a legitimate transport layer checksum-- it is the
159 * purview of the stack to validate that csum_start and csum_offset are set
162 * When the stack requests checksum offload for a packet, the driver MUST
163 * ensure that the checksum is set correctly. A driver can either offload the
164 * checksum calculation to the device, or call skb_checksum_help (in the case
165 * that the device does not support offload for a particular checksum).
167 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
168 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
169 * checksum offload capability.
170 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
171 * on network device checksumming capabilities: if a packet does not match
172 * them, skb_checksum_help or skb_crc32c_help (depending on the value of
173 * csum_not_inet, see item D.) is called to resolve the checksum.
177 * The skb was already checksummed by the protocol, or a checksum is not
180 * CHECKSUM_UNNECESSARY:
182 * This has the same meaning on as CHECKSUM_NONE for checksum offload on
186 * Not used in checksum output. If a driver observes a packet with this value
187 * set in skbuff, if should treat as CHECKSUM_NONE being set.
189 * D. Non-IP checksum (CRC) offloads
191 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
192 * offloading the SCTP CRC in a packet. To perform this offload the stack
193 * will set set csum_start and csum_offset accordingly, set ip_summed to
194 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
195 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
196 * A driver that supports both IP checksum offload and SCTP CRC32c offload
197 * must verify which offload is configured for a packet by testing the
198 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
199 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
201 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
202 * offloading the FCOE CRC in a packet. To perform this offload the stack
203 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
204 * accordingly. Note the there is no indication in the skbuff that the
205 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
206 * both IP checksum offload and FCOE CRC offload must verify which offload
207 * is configured for a packet presumably by inspecting packet headers.
209 * E. Checksumming on output with GSO.
211 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
212 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
213 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
214 * part of the GSO operation is implied. If a checksum is being offloaded
215 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
216 * are set to refer to the outermost checksum being offload (two offloaded
217 * checksums are possible with UDP encapsulation).
220 /* Don't change this without changing skb_csum_unnecessary! */
221 #define CHECKSUM_NONE 0
222 #define CHECKSUM_UNNECESSARY 1
223 #define CHECKSUM_COMPLETE 2
224 #define CHECKSUM_PARTIAL 3
226 /* Maximum value in skb->csum_level */
227 #define SKB_MAX_CSUM_LEVEL 3
229 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
230 #define SKB_WITH_OVERHEAD(X) \
231 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
232 #define SKB_MAX_ORDER(X, ORDER) \
233 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
234 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
235 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
237 /* return minimum truesize of one skb containing X bytes of data */
238 #define SKB_TRUESIZE(X) ((X) + \
239 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
240 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
244 struct pipe_inode_info
;
248 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
249 struct nf_conntrack
{
254 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
255 struct nf_bridge_info
{
258 BRNF_PROTO_UNCHANGED
,
266 struct net_device
*physindev
;
268 /* always valid & non-NULL from FORWARD on, for physdev match */
269 struct net_device
*physoutdev
;
271 /* prerouting: detect dnat in orig/reply direction */
273 struct in6_addr ipv6_daddr
;
275 /* after prerouting + nat detected: store original source
276 * mac since neigh resolution overwrites it, only used while
277 * skb is out in neigh layer.
279 char neigh_header
[8];
284 struct sk_buff_head
{
285 /* These two members must be first. */
286 struct sk_buff
*next
;
287 struct sk_buff
*prev
;
295 /* To allow 64K frame to be packed as single skb without frag_list we
296 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
297 * buffers which do not start on a page boundary.
299 * Since GRO uses frags we allocate at least 16 regardless of page
302 #if (65536/PAGE_SIZE + 1) < 16
303 #define MAX_SKB_FRAGS 16UL
305 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
307 extern int sysctl_max_skb_frags
;
309 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
310 * segment using its current segmentation instead.
312 #define GSO_BY_FRAGS 0xFFFF
314 typedef struct skb_frag_struct skb_frag_t
;
316 struct skb_frag_struct
{
320 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
329 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
334 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
339 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
344 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
349 static inline bool skb_frag_must_loop(struct page
*p
)
351 #if defined(CONFIG_HIGHMEM)
359 * skb_frag_foreach_page - loop over pages in a fragment
361 * @f: skb frag to operate on
362 * @f_off: offset from start of f->page.p
363 * @f_len: length from f_off to loop over
364 * @p: (temp var) current page
365 * @p_off: (temp var) offset from start of current page,
366 * non-zero only on first page.
367 * @p_len: (temp var) length in current page,
368 * < PAGE_SIZE only on first and last page.
369 * @copied: (temp var) length so far, excluding current p_len.
371 * A fragment can hold a compound page, in which case per-page
372 * operations, notably kmap_atomic, must be called for each
375 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
376 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
377 p_off = (f_off) & (PAGE_SIZE - 1), \
378 p_len = skb_frag_must_loop(p) ? \
379 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
382 copied += p_len, p++, p_off = 0, \
383 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
385 #define HAVE_HW_TIME_STAMP
388 * struct skb_shared_hwtstamps - hardware time stamps
389 * @hwtstamp: hardware time stamp transformed into duration
390 * since arbitrary point in time
392 * Software time stamps generated by ktime_get_real() are stored in
395 * hwtstamps can only be compared against other hwtstamps from
398 * This structure is attached to packets as part of the
399 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
401 struct skb_shared_hwtstamps
{
405 /* Definitions for tx_flags in struct skb_shared_info */
407 /* generate hardware time stamp */
408 SKBTX_HW_TSTAMP
= 1 << 0,
410 /* generate software time stamp when queueing packet to NIC */
411 SKBTX_SW_TSTAMP
= 1 << 1,
413 /* device driver is going to provide hardware time stamp */
414 SKBTX_IN_PROGRESS
= 1 << 2,
416 /* device driver supports TX zero-copy buffers */
417 SKBTX_DEV_ZEROCOPY
= 1 << 3,
419 /* generate wifi status information (where possible) */
420 SKBTX_WIFI_STATUS
= 1 << 4,
422 /* This indicates at least one fragment might be overwritten
423 * (as in vmsplice(), sendfile() ...)
424 * If we need to compute a TX checksum, we'll need to copy
425 * all frags to avoid possible bad checksum
427 SKBTX_SHARED_FRAG
= 1 << 5,
429 /* generate software time stamp when entering packet scheduling */
430 SKBTX_SCHED_TSTAMP
= 1 << 6,
433 #define SKBTX_ZEROCOPY_FRAG (SKBTX_DEV_ZEROCOPY | SKBTX_SHARED_FRAG)
434 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
436 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
439 * The callback notifies userspace to release buffers when skb DMA is done in
440 * lower device, the skb last reference should be 0 when calling this.
441 * The zerocopy_success argument is true if zero copy transmit occurred,
442 * false on data copy or out of memory error caused by data copy attempt.
443 * The ctx field is used to track device context.
444 * The desc field is used to track userspace buffer index.
447 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
463 struct user_struct
*user
;
468 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
470 struct ubuf_info
*sock_zerocopy_alloc(struct sock
*sk
, size_t size
);
471 struct ubuf_info
*sock_zerocopy_realloc(struct sock
*sk
, size_t size
,
472 struct ubuf_info
*uarg
);
474 static inline void sock_zerocopy_get(struct ubuf_info
*uarg
)
476 refcount_inc(&uarg
->refcnt
);
479 void sock_zerocopy_put(struct ubuf_info
*uarg
);
480 void sock_zerocopy_put_abort(struct ubuf_info
*uarg
);
482 void sock_zerocopy_callback(struct ubuf_info
*uarg
, bool success
);
484 int skb_zerocopy_iter_stream(struct sock
*sk
, struct sk_buff
*skb
,
485 struct msghdr
*msg
, int len
,
486 struct ubuf_info
*uarg
);
488 /* This data is invariant across clones and lives at
489 * the end of the header data, ie. at skb->end.
491 struct skb_shared_info
{
492 unsigned short _unused
;
493 unsigned char nr_frags
;
495 unsigned short gso_size
;
496 /* Warning: this field is not always filled in (UFO)! */
497 unsigned short gso_segs
;
498 struct sk_buff
*frag_list
;
499 struct skb_shared_hwtstamps hwtstamps
;
500 unsigned int gso_type
;
505 * Warning : all fields before dataref are cleared in __alloc_skb()
509 /* Intermediate layers must ensure that destructor_arg
510 * remains valid until skb destructor */
511 void * destructor_arg
;
513 /* must be last field, see pskb_expand_head() */
514 skb_frag_t frags
[MAX_SKB_FRAGS
];
517 /* We divide dataref into two halves. The higher 16 bits hold references
518 * to the payload part of skb->data. The lower 16 bits hold references to
519 * the entire skb->data. A clone of a headerless skb holds the length of
520 * the header in skb->hdr_len.
522 * All users must obey the rule that the skb->data reference count must be
523 * greater than or equal to the payload reference count.
525 * Holding a reference to the payload part means that the user does not
526 * care about modifications to the header part of skb->data.
528 #define SKB_DATAREF_SHIFT 16
529 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
533 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
534 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
535 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
539 SKB_GSO_TCPV4
= 1 << 0,
541 /* This indicates the skb is from an untrusted source. */
542 SKB_GSO_DODGY
= 1 << 1,
544 /* This indicates the tcp segment has CWR set. */
545 SKB_GSO_TCP_ECN
= 1 << 2,
547 SKB_GSO_TCP_FIXEDID
= 1 << 3,
549 SKB_GSO_TCPV6
= 1 << 4,
551 SKB_GSO_FCOE
= 1 << 5,
553 SKB_GSO_GRE
= 1 << 6,
555 SKB_GSO_GRE_CSUM
= 1 << 7,
557 SKB_GSO_IPXIP4
= 1 << 8,
559 SKB_GSO_IPXIP6
= 1 << 9,
561 SKB_GSO_UDP_TUNNEL
= 1 << 10,
563 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
565 SKB_GSO_PARTIAL
= 1 << 12,
567 SKB_GSO_TUNNEL_REMCSUM
= 1 << 13,
569 SKB_GSO_SCTP
= 1 << 14,
571 SKB_GSO_ESP
= 1 << 15,
574 #if BITS_PER_LONG > 32
575 #define NET_SKBUFF_DATA_USES_OFFSET 1
578 #ifdef NET_SKBUFF_DATA_USES_OFFSET
579 typedef unsigned int sk_buff_data_t
;
581 typedef unsigned char *sk_buff_data_t
;
585 * struct sk_buff - socket buffer
586 * @next: Next buffer in list
587 * @prev: Previous buffer in list
588 * @tstamp: Time we arrived/left
589 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
590 * @sk: Socket we are owned by
591 * @dev: Device we arrived on/are leaving by
592 * @cb: Control buffer. Free for use by every layer. Put private vars here
593 * @_skb_refdst: destination entry (with norefcount bit)
594 * @sp: the security path, used for xfrm
595 * @len: Length of actual data
596 * @data_len: Data length
597 * @mac_len: Length of link layer header
598 * @hdr_len: writable header length of cloned skb
599 * @csum: Checksum (must include start/offset pair)
600 * @csum_start: Offset from skb->head where checksumming should start
601 * @csum_offset: Offset from csum_start where checksum should be stored
602 * @priority: Packet queueing priority
603 * @ignore_df: allow local fragmentation
604 * @cloned: Head may be cloned (check refcnt to be sure)
605 * @ip_summed: Driver fed us an IP checksum
606 * @nohdr: Payload reference only, must not modify header
607 * @pkt_type: Packet class
608 * @fclone: skbuff clone status
609 * @ipvs_property: skbuff is owned by ipvs
610 * @tc_skip_classify: do not classify packet. set by IFB device
611 * @tc_at_ingress: used within tc_classify to distinguish in/egress
612 * @tc_redirected: packet was redirected by a tc action
613 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect
614 * @peeked: this packet has been seen already, so stats have been
615 * done for it, don't do them again
616 * @nf_trace: netfilter packet trace flag
617 * @protocol: Packet protocol from driver
618 * @destructor: Destruct function
619 * @_nfct: Associated connection, if any (with nfctinfo bits)
620 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
621 * @skb_iif: ifindex of device we arrived on
622 * @tc_index: Traffic control index
623 * @hash: the packet hash
624 * @queue_mapping: Queue mapping for multiqueue devices
625 * @xmit_more: More SKBs are pending for this queue
626 * @ndisc_nodetype: router type (from link layer)
627 * @ooo_okay: allow the mapping of a socket to a queue to be changed
628 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
630 * @sw_hash: indicates hash was computed in software stack
631 * @wifi_acked_valid: wifi_acked was set
632 * @wifi_acked: whether frame was acked on wifi or not
633 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
634 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
635 * @dst_pending_confirm: need to confirm neighbour
636 * @napi_id: id of the NAPI struct this skb came from
637 * @secmark: security marking
638 * @mark: Generic packet mark
639 * @vlan_proto: vlan encapsulation protocol
640 * @vlan_tci: vlan tag control information
641 * @inner_protocol: Protocol (encapsulation)
642 * @inner_transport_header: Inner transport layer header (encapsulation)
643 * @inner_network_header: Network layer header (encapsulation)
644 * @inner_mac_header: Link layer header (encapsulation)
645 * @transport_header: Transport layer header
646 * @network_header: Network layer header
647 * @mac_header: Link layer header
648 * @tail: Tail pointer
650 * @head: Head of buffer
651 * @data: Data head pointer
652 * @truesize: Buffer size
653 * @users: User count - see {datagram,tcp}.c
659 /* These two members must be first. */
660 struct sk_buff
*next
;
661 struct sk_buff
*prev
;
668 struct rb_node rbnode
; /* used in netem & tcp stack */
673 struct net_device
*dev
;
674 /* Some protocols might use this space to store information,
675 * while device pointer would be NULL.
676 * UDP receive path is one user.
678 unsigned long dev_scratch
;
681 * This is the control buffer. It is free to use for every
682 * layer. Please put your private variables there. If you
683 * want to keep them across layers you have to do a skb_clone()
684 * first. This is owned by whoever has the skb queued ATM.
686 char cb
[48] __aligned(8);
688 unsigned long _skb_refdst
;
689 void (*destructor
)(struct sk_buff
*skb
);
693 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
696 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
697 struct nf_bridge_info
*nf_bridge
;
704 /* Following fields are _not_ copied in __copy_skb_header()
705 * Note that queue_mapping is here mostly to fill a hole.
707 kmemcheck_bitfield_begin(flags1
);
710 /* if you move cloned around you also must adapt those constants */
711 #ifdef __BIG_ENDIAN_BITFIELD
712 #define CLONED_MASK (1 << 7)
714 #define CLONED_MASK 1
716 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
718 __u8 __cloned_offset
[0];
725 __unused
:1; /* one bit hole */
726 kmemcheck_bitfield_end(flags1
);
728 /* fields enclosed in headers_start/headers_end are copied
729 * using a single memcpy() in __copy_skb_header()
732 __u32 headers_start
[0];
735 /* if you move pkt_type around you also must adapt those constants */
736 #ifdef __BIG_ENDIAN_BITFIELD
737 #define PKT_TYPE_MAX (7 << 5)
739 #define PKT_TYPE_MAX 7
741 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
743 __u8 __pkt_type_offset
[0];
753 __u8 wifi_acked_valid
:1;
757 /* Indicates the inner headers are valid in the skbuff. */
758 __u8 encapsulation
:1;
759 __u8 encap_hdr_csum
:1;
761 __u8 csum_complete_sw
:1;
763 __u8 csum_not_inet
:1;
765 __u8 dst_pending_confirm
:1;
766 #ifdef CONFIG_IPV6_NDISC_NODETYPE
767 __u8 ndisc_nodetype
:2;
769 __u8 ipvs_property
:1;
770 __u8 inner_protocol_type
:1;
771 __u8 remcsum_offload
:1;
772 #ifdef CONFIG_NET_SWITCHDEV
773 __u8 offload_fwd_mark
:1;
775 #ifdef CONFIG_NET_CLS_ACT
776 __u8 tc_skip_classify
:1;
777 __u8 tc_at_ingress
:1;
778 __u8 tc_redirected
:1;
779 __u8 tc_from_ingress
:1;
782 #ifdef CONFIG_NET_SCHED
783 __u16 tc_index
; /* traffic control index */
798 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
800 unsigned int napi_id
;
801 unsigned int sender_cpu
;
804 #ifdef CONFIG_NETWORK_SECMARK
810 __u32 reserved_tailroom
;
814 __be16 inner_protocol
;
818 __u16 inner_transport_header
;
819 __u16 inner_network_header
;
820 __u16 inner_mac_header
;
823 __u16 transport_header
;
824 __u16 network_header
;
828 __u32 headers_end
[0];
831 /* These elements must be at the end, see alloc_skb() for details. */
836 unsigned int truesize
;
842 * Handling routines are only of interest to the kernel
844 #include <linux/slab.h>
847 #define SKB_ALLOC_FCLONE 0x01
848 #define SKB_ALLOC_RX 0x02
849 #define SKB_ALLOC_NAPI 0x04
851 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
852 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
854 return unlikely(skb
->pfmemalloc
);
858 * skb might have a dst pointer attached, refcounted or not.
859 * _skb_refdst low order bit is set if refcount was _not_ taken
861 #define SKB_DST_NOREF 1UL
862 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
864 #define SKB_NFCT_PTRMASK ~(7UL)
866 * skb_dst - returns skb dst_entry
869 * Returns skb dst_entry, regardless of reference taken or not.
871 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
873 /* If refdst was not refcounted, check we still are in a
874 * rcu_read_lock section
876 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
877 !rcu_read_lock_held() &&
878 !rcu_read_lock_bh_held());
879 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
883 * skb_dst_set - sets skb dst
887 * Sets skb dst, assuming a reference was taken on dst and should
888 * be released by skb_dst_drop()
890 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
892 skb
->_skb_refdst
= (unsigned long)dst
;
896 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
900 * Sets skb dst, assuming a reference was not taken on dst.
901 * If dst entry is cached, we do not take reference and dst_release
902 * will be avoided by refdst_drop. If dst entry is not cached, we take
903 * reference, so that last dst_release can destroy the dst immediately.
905 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
907 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
908 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
912 * skb_dst_is_noref - Test if skb dst isn't refcounted
915 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
917 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
920 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
922 return (struct rtable
*)skb_dst(skb
);
925 /* For mangling skb->pkt_type from user space side from applications
926 * such as nft, tc, etc, we only allow a conservative subset of
927 * possible pkt_types to be set.
929 static inline bool skb_pkt_type_ok(u32 ptype
)
931 return ptype
<= PACKET_OTHERHOST
;
934 static inline unsigned int skb_napi_id(const struct sk_buff
*skb
)
936 #ifdef CONFIG_NET_RX_BUSY_POLL
943 /* decrement the reference count and return true if we can free the skb */
944 static inline bool skb_unref(struct sk_buff
*skb
)
948 if (likely(refcount_read(&skb
->users
) == 1))
950 else if (likely(!refcount_dec_and_test(&skb
->users
)))
956 void skb_release_head_state(struct sk_buff
*skb
);
957 void kfree_skb(struct sk_buff
*skb
);
958 void kfree_skb_list(struct sk_buff
*segs
);
959 void skb_tx_error(struct sk_buff
*skb
);
960 void consume_skb(struct sk_buff
*skb
);
961 void __consume_stateless_skb(struct sk_buff
*skb
);
962 void __kfree_skb(struct sk_buff
*skb
);
963 extern struct kmem_cache
*skbuff_head_cache
;
965 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
966 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
967 bool *fragstolen
, int *delta_truesize
);
969 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
971 struct sk_buff
*__build_skb(void *data
, unsigned int frag_size
);
972 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
973 static inline struct sk_buff
*alloc_skb(unsigned int size
,
976 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
979 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
980 unsigned long data_len
,
985 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
986 struct sk_buff_fclones
{
991 refcount_t fclone_ref
;
995 * skb_fclone_busy - check if fclone is busy
999 * Returns true if skb is a fast clone, and its clone is not freed.
1000 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1001 * so we also check that this didnt happen.
1003 static inline bool skb_fclone_busy(const struct sock
*sk
,
1004 const struct sk_buff
*skb
)
1006 const struct sk_buff_fclones
*fclones
;
1008 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
1010 return skb
->fclone
== SKB_FCLONE_ORIG
&&
1011 refcount_read(&fclones
->fclone_ref
) > 1 &&
1012 fclones
->skb2
.sk
== sk
;
1015 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
1018 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
1021 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
1022 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
1023 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
1024 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
1025 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
1026 gfp_t gfp_mask
, bool fclone
);
1027 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
1030 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
1033 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
1034 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
1035 unsigned int headroom
);
1036 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
1037 int newtailroom
, gfp_t priority
);
1038 int __must_check
skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
1039 int offset
, int len
);
1040 int __must_check
skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
,
1041 int offset
, int len
);
1042 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
1043 int __skb_pad(struct sk_buff
*skb
, int pad
, bool free_on_error
);
1046 * skb_pad - zero pad the tail of an skb
1047 * @skb: buffer to pad
1048 * @pad: space to pad
1050 * Ensure that a buffer is followed by a padding area that is zero
1051 * filled. Used by network drivers which may DMA or transfer data
1052 * beyond the buffer end onto the wire.
1054 * May return error in out of memory cases. The skb is freed on error.
1056 static inline int skb_pad(struct sk_buff
*skb
, int pad
)
1058 return __skb_pad(skb
, pad
, true);
1060 #define dev_kfree_skb(a) consume_skb(a)
1062 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
1063 int getfrag(void *from
, char *to
, int offset
,
1064 int len
, int odd
, struct sk_buff
*skb
),
1065 void *from
, int length
);
1067 int skb_append_pagefrags(struct sk_buff
*skb
, struct page
*page
,
1068 int offset
, size_t size
);
1070 struct skb_seq_state
{
1074 __u32 stepped_offset
;
1075 struct sk_buff
*root_skb
;
1076 struct sk_buff
*cur_skb
;
1080 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1081 unsigned int to
, struct skb_seq_state
*st
);
1082 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1083 struct skb_seq_state
*st
);
1084 void skb_abort_seq_read(struct skb_seq_state
*st
);
1086 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1087 unsigned int to
, struct ts_config
*config
);
1090 * Packet hash types specify the type of hash in skb_set_hash.
1092 * Hash types refer to the protocol layer addresses which are used to
1093 * construct a packet's hash. The hashes are used to differentiate or identify
1094 * flows of the protocol layer for the hash type. Hash types are either
1095 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1097 * Properties of hashes:
1099 * 1) Two packets in different flows have different hash values
1100 * 2) Two packets in the same flow should have the same hash value
1102 * A hash at a higher layer is considered to be more specific. A driver should
1103 * set the most specific hash possible.
1105 * A driver cannot indicate a more specific hash than the layer at which a hash
1106 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1108 * A driver may indicate a hash level which is less specific than the
1109 * actual layer the hash was computed on. For instance, a hash computed
1110 * at L4 may be considered an L3 hash. This should only be done if the
1111 * driver can't unambiguously determine that the HW computed the hash at
1112 * the higher layer. Note that the "should" in the second property above
1115 enum pkt_hash_types
{
1116 PKT_HASH_TYPE_NONE
, /* Undefined type */
1117 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
1118 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
1119 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
1122 static inline void skb_clear_hash(struct sk_buff
*skb
)
1129 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
1132 skb_clear_hash(skb
);
1136 __skb_set_hash(struct sk_buff
*skb
, __u32 hash
, bool is_sw
, bool is_l4
)
1138 skb
->l4_hash
= is_l4
;
1139 skb
->sw_hash
= is_sw
;
1144 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
1146 /* Used by drivers to set hash from HW */
1147 __skb_set_hash(skb
, hash
, false, type
== PKT_HASH_TYPE_L4
);
1151 __skb_set_sw_hash(struct sk_buff
*skb
, __u32 hash
, bool is_l4
)
1153 __skb_set_hash(skb
, hash
, true, is_l4
);
1156 void __skb_get_hash(struct sk_buff
*skb
);
1157 u32
__skb_get_hash_symmetric(const struct sk_buff
*skb
);
1158 u32
skb_get_poff(const struct sk_buff
*skb
);
1159 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
1160 const struct flow_keys
*keys
, int hlen
);
1161 __be32
__skb_flow_get_ports(const struct sk_buff
*skb
, int thoff
, u8 ip_proto
,
1162 void *data
, int hlen_proto
);
1164 static inline __be32
skb_flow_get_ports(const struct sk_buff
*skb
,
1165 int thoff
, u8 ip_proto
)
1167 return __skb_flow_get_ports(skb
, thoff
, ip_proto
, NULL
, 0);
1170 void skb_flow_dissector_init(struct flow_dissector
*flow_dissector
,
1171 const struct flow_dissector_key
*key
,
1172 unsigned int key_count
);
1174 bool __skb_flow_dissect(const struct sk_buff
*skb
,
1175 struct flow_dissector
*flow_dissector
,
1176 void *target_container
,
1177 void *data
, __be16 proto
, int nhoff
, int hlen
,
1178 unsigned int flags
);
1180 static inline bool skb_flow_dissect(const struct sk_buff
*skb
,
1181 struct flow_dissector
*flow_dissector
,
1182 void *target_container
, unsigned int flags
)
1184 return __skb_flow_dissect(skb
, flow_dissector
, target_container
,
1185 NULL
, 0, 0, 0, flags
);
1188 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff
*skb
,
1189 struct flow_keys
*flow
,
1192 memset(flow
, 0, sizeof(*flow
));
1193 return __skb_flow_dissect(skb
, &flow_keys_dissector
, flow
,
1194 NULL
, 0, 0, 0, flags
);
1197 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys
*flow
,
1198 void *data
, __be16 proto
,
1199 int nhoff
, int hlen
,
1202 memset(flow
, 0, sizeof(*flow
));
1203 return __skb_flow_dissect(NULL
, &flow_keys_buf_dissector
, flow
,
1204 data
, proto
, nhoff
, hlen
, flags
);
1207 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
1209 if (!skb
->l4_hash
&& !skb
->sw_hash
)
1210 __skb_get_hash(skb
);
1215 static inline __u32
skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
)
1217 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1218 struct flow_keys keys
;
1219 __u32 hash
= __get_hash_from_flowi6(fl6
, &keys
);
1221 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1227 __u32
skb_get_hash_perturb(const struct sk_buff
*skb
, u32 perturb
);
1229 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
1234 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
1236 to
->hash
= from
->hash
;
1237 to
->sw_hash
= from
->sw_hash
;
1238 to
->l4_hash
= from
->l4_hash
;
1241 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1242 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1244 return skb
->head
+ skb
->end
;
1247 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1252 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1257 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1259 return skb
->end
- skb
->head
;
1264 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1266 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
1268 return &skb_shinfo(skb
)->hwtstamps
;
1271 static inline struct ubuf_info
*skb_zcopy(struct sk_buff
*skb
)
1273 bool is_zcopy
= skb
&& skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
;
1275 return is_zcopy
? skb_uarg(skb
) : NULL
;
1278 static inline void skb_zcopy_set(struct sk_buff
*skb
, struct ubuf_info
*uarg
)
1280 if (skb
&& uarg
&& !skb_zcopy(skb
)) {
1281 sock_zerocopy_get(uarg
);
1282 skb_shinfo(skb
)->destructor_arg
= uarg
;
1283 skb_shinfo(skb
)->tx_flags
|= SKBTX_ZEROCOPY_FRAG
;
1287 /* Release a reference on a zerocopy structure */
1288 static inline void skb_zcopy_clear(struct sk_buff
*skb
, bool zerocopy
)
1290 struct ubuf_info
*uarg
= skb_zcopy(skb
);
1293 if (uarg
->callback
== sock_zerocopy_callback
) {
1294 uarg
->zerocopy
= uarg
->zerocopy
&& zerocopy
;
1295 sock_zerocopy_put(uarg
);
1297 uarg
->callback(uarg
, zerocopy
);
1300 skb_shinfo(skb
)->tx_flags
&= ~SKBTX_ZEROCOPY_FRAG
;
1304 /* Abort a zerocopy operation and revert zckey on error in send syscall */
1305 static inline void skb_zcopy_abort(struct sk_buff
*skb
)
1307 struct ubuf_info
*uarg
= skb_zcopy(skb
);
1310 sock_zerocopy_put_abort(uarg
);
1311 skb_shinfo(skb
)->tx_flags
&= ~SKBTX_ZEROCOPY_FRAG
;
1316 * skb_queue_empty - check if a queue is empty
1319 * Returns true if the queue is empty, false otherwise.
1321 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1323 return list
->next
== (const struct sk_buff
*) list
;
1327 * skb_queue_is_last - check if skb is the last entry in the queue
1331 * Returns true if @skb is the last buffer on the list.
1333 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1334 const struct sk_buff
*skb
)
1336 return skb
->next
== (const struct sk_buff
*) list
;
1340 * skb_queue_is_first - check if skb is the first entry in the queue
1344 * Returns true if @skb is the first buffer on the list.
1346 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1347 const struct sk_buff
*skb
)
1349 return skb
->prev
== (const struct sk_buff
*) list
;
1353 * skb_queue_next - return the next packet in the queue
1355 * @skb: current buffer
1357 * Return the next packet in @list after @skb. It is only valid to
1358 * call this if skb_queue_is_last() evaluates to false.
1360 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1361 const struct sk_buff
*skb
)
1363 /* This BUG_ON may seem severe, but if we just return then we
1364 * are going to dereference garbage.
1366 BUG_ON(skb_queue_is_last(list
, skb
));
1371 * skb_queue_prev - return the prev packet in the queue
1373 * @skb: current buffer
1375 * Return the prev packet in @list before @skb. It is only valid to
1376 * call this if skb_queue_is_first() evaluates to false.
1378 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1379 const struct sk_buff
*skb
)
1381 /* This BUG_ON may seem severe, but if we just return then we
1382 * are going to dereference garbage.
1384 BUG_ON(skb_queue_is_first(list
, skb
));
1389 * skb_get - reference buffer
1390 * @skb: buffer to reference
1392 * Makes another reference to a socket buffer and returns a pointer
1395 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1397 refcount_inc(&skb
->users
);
1402 * If users == 1, we are the only owner and are can avoid redundant
1407 * skb_cloned - is the buffer a clone
1408 * @skb: buffer to check
1410 * Returns true if the buffer was generated with skb_clone() and is
1411 * one of multiple shared copies of the buffer. Cloned buffers are
1412 * shared data so must not be written to under normal circumstances.
1414 static inline int skb_cloned(const struct sk_buff
*skb
)
1416 return skb
->cloned
&&
1417 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1420 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1422 might_sleep_if(gfpflags_allow_blocking(pri
));
1424 if (skb_cloned(skb
))
1425 return pskb_expand_head(skb
, 0, 0, pri
);
1431 * skb_header_cloned - is the header a clone
1432 * @skb: buffer to check
1434 * Returns true if modifying the header part of the buffer requires
1435 * the data to be copied.
1437 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1444 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1445 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1446 return dataref
!= 1;
1449 static inline int skb_header_unclone(struct sk_buff
*skb
, gfp_t pri
)
1451 might_sleep_if(gfpflags_allow_blocking(pri
));
1453 if (skb_header_cloned(skb
))
1454 return pskb_expand_head(skb
, 0, 0, pri
);
1460 * skb_header_release - release reference to header
1461 * @skb: buffer to operate on
1463 * Drop a reference to the header part of the buffer. This is done
1464 * by acquiring a payload reference. You must not read from the header
1465 * part of skb->data after this.
1466 * Note : Check if you can use __skb_header_release() instead.
1468 static inline void skb_header_release(struct sk_buff
*skb
)
1472 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1476 * __skb_header_release - release reference to header
1477 * @skb: buffer to operate on
1479 * Variant of skb_header_release() assuming skb is private to caller.
1480 * We can avoid one atomic operation.
1482 static inline void __skb_header_release(struct sk_buff
*skb
)
1485 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1490 * skb_shared - is the buffer shared
1491 * @skb: buffer to check
1493 * Returns true if more than one person has a reference to this
1496 static inline int skb_shared(const struct sk_buff
*skb
)
1498 return refcount_read(&skb
->users
) != 1;
1502 * skb_share_check - check if buffer is shared and if so clone it
1503 * @skb: buffer to check
1504 * @pri: priority for memory allocation
1506 * If the buffer is shared the buffer is cloned and the old copy
1507 * drops a reference. A new clone with a single reference is returned.
1508 * If the buffer is not shared the original buffer is returned. When
1509 * being called from interrupt status or with spinlocks held pri must
1512 * NULL is returned on a memory allocation failure.
1514 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1516 might_sleep_if(gfpflags_allow_blocking(pri
));
1517 if (skb_shared(skb
)) {
1518 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1530 * Copy shared buffers into a new sk_buff. We effectively do COW on
1531 * packets to handle cases where we have a local reader and forward
1532 * and a couple of other messy ones. The normal one is tcpdumping
1533 * a packet thats being forwarded.
1537 * skb_unshare - make a copy of a shared buffer
1538 * @skb: buffer to check
1539 * @pri: priority for memory allocation
1541 * If the socket buffer is a clone then this function creates a new
1542 * copy of the data, drops a reference count on the old copy and returns
1543 * the new copy with the reference count at 1. If the buffer is not a clone
1544 * the original buffer is returned. When called with a spinlock held or
1545 * from interrupt state @pri must be %GFP_ATOMIC
1547 * %NULL is returned on a memory allocation failure.
1549 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1552 might_sleep_if(gfpflags_allow_blocking(pri
));
1553 if (skb_cloned(skb
)) {
1554 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1556 /* Free our shared copy */
1567 * skb_peek - peek at the head of an &sk_buff_head
1568 * @list_: list to peek at
1570 * Peek an &sk_buff. Unlike most other operations you _MUST_
1571 * be careful with this one. A peek leaves the buffer on the
1572 * list and someone else may run off with it. You must hold
1573 * the appropriate locks or have a private queue to do this.
1575 * Returns %NULL for an empty list or a pointer to the head element.
1576 * The reference count is not incremented and the reference is therefore
1577 * volatile. Use with caution.
1579 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1581 struct sk_buff
*skb
= list_
->next
;
1583 if (skb
== (struct sk_buff
*)list_
)
1589 * skb_peek_next - peek skb following the given one from a queue
1590 * @skb: skb to start from
1591 * @list_: list to peek at
1593 * Returns %NULL when the end of the list is met or a pointer to the
1594 * next element. The reference count is not incremented and the
1595 * reference is therefore volatile. Use with caution.
1597 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1598 const struct sk_buff_head
*list_
)
1600 struct sk_buff
*next
= skb
->next
;
1602 if (next
== (struct sk_buff
*)list_
)
1608 * skb_peek_tail - peek at the tail of an &sk_buff_head
1609 * @list_: list to peek at
1611 * Peek an &sk_buff. Unlike most other operations you _MUST_
1612 * be careful with this one. A peek leaves the buffer on the
1613 * list and someone else may run off with it. You must hold
1614 * the appropriate locks or have a private queue to do this.
1616 * Returns %NULL for an empty list or a pointer to the tail element.
1617 * The reference count is not incremented and the reference is therefore
1618 * volatile. Use with caution.
1620 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1622 struct sk_buff
*skb
= list_
->prev
;
1624 if (skb
== (struct sk_buff
*)list_
)
1631 * skb_queue_len - get queue length
1632 * @list_: list to measure
1634 * Return the length of an &sk_buff queue.
1636 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1642 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1643 * @list: queue to initialize
1645 * This initializes only the list and queue length aspects of
1646 * an sk_buff_head object. This allows to initialize the list
1647 * aspects of an sk_buff_head without reinitializing things like
1648 * the spinlock. It can also be used for on-stack sk_buff_head
1649 * objects where the spinlock is known to not be used.
1651 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1653 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1658 * This function creates a split out lock class for each invocation;
1659 * this is needed for now since a whole lot of users of the skb-queue
1660 * infrastructure in drivers have different locking usage (in hardirq)
1661 * than the networking core (in softirq only). In the long run either the
1662 * network layer or drivers should need annotation to consolidate the
1663 * main types of usage into 3 classes.
1665 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1667 spin_lock_init(&list
->lock
);
1668 __skb_queue_head_init(list
);
1671 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1672 struct lock_class_key
*class)
1674 skb_queue_head_init(list
);
1675 lockdep_set_class(&list
->lock
, class);
1679 * Insert an sk_buff on a list.
1681 * The "__skb_xxxx()" functions are the non-atomic ones that
1682 * can only be called with interrupts disabled.
1684 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1685 struct sk_buff_head
*list
);
1686 static inline void __skb_insert(struct sk_buff
*newsk
,
1687 struct sk_buff
*prev
, struct sk_buff
*next
,
1688 struct sk_buff_head
*list
)
1692 next
->prev
= prev
->next
= newsk
;
1696 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1697 struct sk_buff
*prev
,
1698 struct sk_buff
*next
)
1700 struct sk_buff
*first
= list
->next
;
1701 struct sk_buff
*last
= list
->prev
;
1711 * skb_queue_splice - join two skb lists, this is designed for stacks
1712 * @list: the new list to add
1713 * @head: the place to add it in the first list
1715 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1716 struct sk_buff_head
*head
)
1718 if (!skb_queue_empty(list
)) {
1719 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1720 head
->qlen
+= list
->qlen
;
1725 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1726 * @list: the new list to add
1727 * @head: the place to add it in the first list
1729 * The list at @list is reinitialised
1731 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1732 struct sk_buff_head
*head
)
1734 if (!skb_queue_empty(list
)) {
1735 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1736 head
->qlen
+= list
->qlen
;
1737 __skb_queue_head_init(list
);
1742 * skb_queue_splice_tail - join two skb lists, each list being a queue
1743 * @list: the new list to add
1744 * @head: the place to add it in the first list
1746 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1747 struct sk_buff_head
*head
)
1749 if (!skb_queue_empty(list
)) {
1750 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1751 head
->qlen
+= list
->qlen
;
1756 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1757 * @list: the new list to add
1758 * @head: the place to add it in the first list
1760 * Each of the lists is a queue.
1761 * The list at @list is reinitialised
1763 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1764 struct sk_buff_head
*head
)
1766 if (!skb_queue_empty(list
)) {
1767 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1768 head
->qlen
+= list
->qlen
;
1769 __skb_queue_head_init(list
);
1774 * __skb_queue_after - queue a buffer at the list head
1775 * @list: list to use
1776 * @prev: place after this buffer
1777 * @newsk: buffer to queue
1779 * Queue a buffer int the middle of a list. This function takes no locks
1780 * and you must therefore hold required locks before calling it.
1782 * A buffer cannot be placed on two lists at the same time.
1784 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1785 struct sk_buff
*prev
,
1786 struct sk_buff
*newsk
)
1788 __skb_insert(newsk
, prev
, prev
->next
, list
);
1791 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1792 struct sk_buff_head
*list
);
1794 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1795 struct sk_buff
*next
,
1796 struct sk_buff
*newsk
)
1798 __skb_insert(newsk
, next
->prev
, next
, list
);
1802 * __skb_queue_head - queue a buffer at the list head
1803 * @list: list to use
1804 * @newsk: buffer to queue
1806 * Queue a buffer at the start of a list. This function takes no locks
1807 * and you must therefore hold required locks before calling it.
1809 * A buffer cannot be placed on two lists at the same time.
1811 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1812 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1813 struct sk_buff
*newsk
)
1815 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1819 * __skb_queue_tail - queue a buffer at the list tail
1820 * @list: list to use
1821 * @newsk: buffer to queue
1823 * Queue a buffer at the end of a list. This function takes no locks
1824 * and you must therefore hold required locks before calling it.
1826 * A buffer cannot be placed on two lists at the same time.
1828 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1829 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1830 struct sk_buff
*newsk
)
1832 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1836 * remove sk_buff from list. _Must_ be called atomically, and with
1839 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1840 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1842 struct sk_buff
*next
, *prev
;
1847 skb
->next
= skb
->prev
= NULL
;
1853 * __skb_dequeue - remove from the head of the queue
1854 * @list: list to dequeue from
1856 * Remove the head of the list. This function does not take any locks
1857 * so must be used with appropriate locks held only. The head item is
1858 * returned or %NULL if the list is empty.
1860 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1861 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1863 struct sk_buff
*skb
= skb_peek(list
);
1865 __skb_unlink(skb
, list
);
1870 * __skb_dequeue_tail - remove from the tail of the queue
1871 * @list: list to dequeue from
1873 * Remove the tail of the list. This function does not take any locks
1874 * so must be used with appropriate locks held only. The tail item is
1875 * returned or %NULL if the list is empty.
1877 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1878 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1880 struct sk_buff
*skb
= skb_peek_tail(list
);
1882 __skb_unlink(skb
, list
);
1887 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1889 return skb
->data_len
;
1892 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1894 return skb
->len
- skb
->data_len
;
1897 static inline unsigned int __skb_pagelen(const struct sk_buff
*skb
)
1899 unsigned int i
, len
= 0;
1901 for (i
= skb_shinfo(skb
)->nr_frags
- 1; (int)i
>= 0; i
--)
1902 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1906 static inline unsigned int skb_pagelen(const struct sk_buff
*skb
)
1908 return skb_headlen(skb
) + __skb_pagelen(skb
);
1912 * __skb_fill_page_desc - initialise a paged fragment in an skb
1913 * @skb: buffer containing fragment to be initialised
1914 * @i: paged fragment index to initialise
1915 * @page: the page to use for this fragment
1916 * @off: the offset to the data with @page
1917 * @size: the length of the data
1919 * Initialises the @i'th fragment of @skb to point to &size bytes at
1920 * offset @off within @page.
1922 * Does not take any additional reference on the fragment.
1924 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1925 struct page
*page
, int off
, int size
)
1927 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1930 * Propagate page pfmemalloc to the skb if we can. The problem is
1931 * that not all callers have unique ownership of the page but rely
1932 * on page_is_pfmemalloc doing the right thing(tm).
1934 frag
->page
.p
= page
;
1935 frag
->page_offset
= off
;
1936 skb_frag_size_set(frag
, size
);
1938 page
= compound_head(page
);
1939 if (page_is_pfmemalloc(page
))
1940 skb
->pfmemalloc
= true;
1944 * skb_fill_page_desc - initialise a paged fragment in an skb
1945 * @skb: buffer containing fragment to be initialised
1946 * @i: paged fragment index to initialise
1947 * @page: the page to use for this fragment
1948 * @off: the offset to the data with @page
1949 * @size: the length of the data
1951 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1952 * @skb to point to @size bytes at offset @off within @page. In
1953 * addition updates @skb such that @i is the last fragment.
1955 * Does not take any additional reference on the fragment.
1957 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1958 struct page
*page
, int off
, int size
)
1960 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1961 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1964 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1965 int size
, unsigned int truesize
);
1967 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1968 unsigned int truesize
);
1970 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1971 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1972 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1974 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1975 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1977 return skb
->head
+ skb
->tail
;
1980 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1982 skb
->tail
= skb
->data
- skb
->head
;
1985 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1987 skb_reset_tail_pointer(skb
);
1988 skb
->tail
+= offset
;
1991 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1992 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1997 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1999 skb
->tail
= skb
->data
;
2002 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
2004 skb
->tail
= skb
->data
+ offset
;
2007 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2010 * Add data to an sk_buff
2012 void *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
2013 void *skb_put(struct sk_buff
*skb
, unsigned int len
);
2014 static inline void *__skb_put(struct sk_buff
*skb
, unsigned int len
)
2016 void *tmp
= skb_tail_pointer(skb
);
2017 SKB_LINEAR_ASSERT(skb
);
2023 static inline void *__skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
2025 void *tmp
= __skb_put(skb
, len
);
2027 memset(tmp
, 0, len
);
2031 static inline void *__skb_put_data(struct sk_buff
*skb
, const void *data
,
2034 void *tmp
= __skb_put(skb
, len
);
2036 memcpy(tmp
, data
, len
);
2040 static inline void __skb_put_u8(struct sk_buff
*skb
, u8 val
)
2042 *(u8
*)__skb_put(skb
, 1) = val
;
2045 static inline void *skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
2047 void *tmp
= skb_put(skb
, len
);
2049 memset(tmp
, 0, len
);
2054 static inline void *skb_put_data(struct sk_buff
*skb
, const void *data
,
2057 void *tmp
= skb_put(skb
, len
);
2059 memcpy(tmp
, data
, len
);
2064 static inline void skb_put_u8(struct sk_buff
*skb
, u8 val
)
2066 *(u8
*)skb_put(skb
, 1) = val
;
2069 void *skb_push(struct sk_buff
*skb
, unsigned int len
);
2070 static inline void *__skb_push(struct sk_buff
*skb
, unsigned int len
)
2077 void *skb_pull(struct sk_buff
*skb
, unsigned int len
);
2078 static inline void *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
2081 BUG_ON(skb
->len
< skb
->data_len
);
2082 return skb
->data
+= len
;
2085 static inline void *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
2087 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
2090 void *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
2092 static inline void *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
2094 if (len
> skb_headlen(skb
) &&
2095 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
2098 return skb
->data
+= len
;
2101 static inline void *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
2103 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
2106 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
2108 if (likely(len
<= skb_headlen(skb
)))
2110 if (unlikely(len
> skb
->len
))
2112 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
2115 void skb_condense(struct sk_buff
*skb
);
2118 * skb_headroom - bytes at buffer head
2119 * @skb: buffer to check
2121 * Return the number of bytes of free space at the head of an &sk_buff.
2123 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
2125 return skb
->data
- skb
->head
;
2129 * skb_tailroom - bytes at buffer end
2130 * @skb: buffer to check
2132 * Return the number of bytes of free space at the tail of an sk_buff
2134 static inline int skb_tailroom(const struct sk_buff
*skb
)
2136 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
2140 * skb_availroom - bytes at buffer end
2141 * @skb: buffer to check
2143 * Return the number of bytes of free space at the tail of an sk_buff
2144 * allocated by sk_stream_alloc()
2146 static inline int skb_availroom(const struct sk_buff
*skb
)
2148 if (skb_is_nonlinear(skb
))
2151 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
2155 * skb_reserve - adjust headroom
2156 * @skb: buffer to alter
2157 * @len: bytes to move
2159 * Increase the headroom of an empty &sk_buff by reducing the tail
2160 * room. This is only allowed for an empty buffer.
2162 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
2169 * skb_tailroom_reserve - adjust reserved_tailroom
2170 * @skb: buffer to alter
2171 * @mtu: maximum amount of headlen permitted
2172 * @needed_tailroom: minimum amount of reserved_tailroom
2174 * Set reserved_tailroom so that headlen can be as large as possible but
2175 * not larger than mtu and tailroom cannot be smaller than
2177 * The required headroom should already have been reserved before using
2180 static inline void skb_tailroom_reserve(struct sk_buff
*skb
, unsigned int mtu
,
2181 unsigned int needed_tailroom
)
2183 SKB_LINEAR_ASSERT(skb
);
2184 if (mtu
< skb_tailroom(skb
) - needed_tailroom
)
2185 /* use at most mtu */
2186 skb
->reserved_tailroom
= skb_tailroom(skb
) - mtu
;
2188 /* use up to all available space */
2189 skb
->reserved_tailroom
= needed_tailroom
;
2192 #define ENCAP_TYPE_ETHER 0
2193 #define ENCAP_TYPE_IPPROTO 1
2195 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
2198 skb
->inner_protocol
= protocol
;
2199 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
2202 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
2205 skb
->inner_ipproto
= ipproto
;
2206 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
2209 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
2211 skb
->inner_mac_header
= skb
->mac_header
;
2212 skb
->inner_network_header
= skb
->network_header
;
2213 skb
->inner_transport_header
= skb
->transport_header
;
2216 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
2218 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
2221 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2224 return skb
->head
+ skb
->inner_transport_header
;
2227 static inline int skb_inner_transport_offset(const struct sk_buff
*skb
)
2229 return skb_inner_transport_header(skb
) - skb
->data
;
2232 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
2234 skb
->inner_transport_header
= skb
->data
- skb
->head
;
2237 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
2240 skb_reset_inner_transport_header(skb
);
2241 skb
->inner_transport_header
+= offset
;
2244 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
2246 return skb
->head
+ skb
->inner_network_header
;
2249 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
2251 skb
->inner_network_header
= skb
->data
- skb
->head
;
2254 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
2257 skb_reset_inner_network_header(skb
);
2258 skb
->inner_network_header
+= offset
;
2261 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
2263 return skb
->head
+ skb
->inner_mac_header
;
2266 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
2268 skb
->inner_mac_header
= skb
->data
- skb
->head
;
2271 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
2274 skb_reset_inner_mac_header(skb
);
2275 skb
->inner_mac_header
+= offset
;
2277 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
2279 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
2282 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
2284 return skb
->head
+ skb
->transport_header
;
2287 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
2289 skb
->transport_header
= skb
->data
- skb
->head
;
2292 static inline void skb_set_transport_header(struct sk_buff
*skb
,
2295 skb_reset_transport_header(skb
);
2296 skb
->transport_header
+= offset
;
2299 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
2301 return skb
->head
+ skb
->network_header
;
2304 static inline void skb_reset_network_header(struct sk_buff
*skb
)
2306 skb
->network_header
= skb
->data
- skb
->head
;
2309 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
2311 skb_reset_network_header(skb
);
2312 skb
->network_header
+= offset
;
2315 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
2317 return skb
->head
+ skb
->mac_header
;
2320 static inline int skb_mac_offset(const struct sk_buff
*skb
)
2322 return skb_mac_header(skb
) - skb
->data
;
2325 static inline u32
skb_mac_header_len(const struct sk_buff
*skb
)
2327 return skb
->network_header
- skb
->mac_header
;
2330 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
2332 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
2335 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
2337 skb
->mac_header
= skb
->data
- skb
->head
;
2340 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
2342 skb_reset_mac_header(skb
);
2343 skb
->mac_header
+= offset
;
2346 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
2348 skb
->mac_header
= skb
->network_header
;
2351 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
2352 const int offset_hint
)
2354 struct flow_keys keys
;
2356 if (skb_transport_header_was_set(skb
))
2358 else if (skb_flow_dissect_flow_keys(skb
, &keys
, 0))
2359 skb_set_transport_header(skb
, keys
.control
.thoff
);
2361 skb_set_transport_header(skb
, offset_hint
);
2364 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
2366 if (skb_mac_header_was_set(skb
)) {
2367 const unsigned char *old_mac
= skb_mac_header(skb
);
2369 skb_set_mac_header(skb
, -skb
->mac_len
);
2370 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
2374 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
2376 return skb
->csum_start
- skb_headroom(skb
);
2379 static inline unsigned char *skb_checksum_start(const struct sk_buff
*skb
)
2381 return skb
->head
+ skb
->csum_start
;
2384 static inline int skb_transport_offset(const struct sk_buff
*skb
)
2386 return skb_transport_header(skb
) - skb
->data
;
2389 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
2391 return skb
->transport_header
- skb
->network_header
;
2394 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
2396 return skb
->inner_transport_header
- skb
->inner_network_header
;
2399 static inline int skb_network_offset(const struct sk_buff
*skb
)
2401 return skb_network_header(skb
) - skb
->data
;
2404 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
2406 return skb_inner_network_header(skb
) - skb
->data
;
2409 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
2411 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
2415 * CPUs often take a performance hit when accessing unaligned memory
2416 * locations. The actual performance hit varies, it can be small if the
2417 * hardware handles it or large if we have to take an exception and fix it
2420 * Since an ethernet header is 14 bytes network drivers often end up with
2421 * the IP header at an unaligned offset. The IP header can be aligned by
2422 * shifting the start of the packet by 2 bytes. Drivers should do this
2425 * skb_reserve(skb, NET_IP_ALIGN);
2427 * The downside to this alignment of the IP header is that the DMA is now
2428 * unaligned. On some architectures the cost of an unaligned DMA is high
2429 * and this cost outweighs the gains made by aligning the IP header.
2431 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2434 #ifndef NET_IP_ALIGN
2435 #define NET_IP_ALIGN 2
2439 * The networking layer reserves some headroom in skb data (via
2440 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2441 * the header has to grow. In the default case, if the header has to grow
2442 * 32 bytes or less we avoid the reallocation.
2444 * Unfortunately this headroom changes the DMA alignment of the resulting
2445 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2446 * on some architectures. An architecture can override this value,
2447 * perhaps setting it to a cacheline in size (since that will maintain
2448 * cacheline alignment of the DMA). It must be a power of 2.
2450 * Various parts of the networking layer expect at least 32 bytes of
2451 * headroom, you should not reduce this.
2453 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2454 * to reduce average number of cache lines per packet.
2455 * get_rps_cpus() for example only access one 64 bytes aligned block :
2456 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2459 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2462 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2464 static inline void __skb_set_length(struct sk_buff
*skb
, unsigned int len
)
2466 if (unlikely(skb_is_nonlinear(skb
))) {
2471 skb_set_tail_pointer(skb
, len
);
2474 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2476 __skb_set_length(skb
, len
);
2479 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2481 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2484 return ___pskb_trim(skb
, len
);
2485 __skb_trim(skb
, len
);
2489 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2491 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2495 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2496 * @skb: buffer to alter
2499 * This is identical to pskb_trim except that the caller knows that
2500 * the skb is not cloned so we should never get an error due to out-
2503 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2505 int err
= pskb_trim(skb
, len
);
2509 static inline int __skb_grow(struct sk_buff
*skb
, unsigned int len
)
2511 unsigned int diff
= len
- skb
->len
;
2513 if (skb_tailroom(skb
) < diff
) {
2514 int ret
= pskb_expand_head(skb
, 0, diff
- skb_tailroom(skb
),
2519 __skb_set_length(skb
, len
);
2524 * skb_orphan - orphan a buffer
2525 * @skb: buffer to orphan
2527 * If a buffer currently has an owner then we call the owner's
2528 * destructor function and make the @skb unowned. The buffer continues
2529 * to exist but is no longer charged to its former owner.
2531 static inline void skb_orphan(struct sk_buff
*skb
)
2533 if (skb
->destructor
) {
2534 skb
->destructor(skb
);
2535 skb
->destructor
= NULL
;
2543 * skb_orphan_frags - orphan the frags contained in a buffer
2544 * @skb: buffer to orphan frags from
2545 * @gfp_mask: allocation mask for replacement pages
2547 * For each frag in the SKB which needs a destructor (i.e. has an
2548 * owner) create a copy of that frag and release the original
2549 * page by calling the destructor.
2551 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2553 if (likely(!skb_zcopy(skb
)))
2555 if (skb_uarg(skb
)->callback
== sock_zerocopy_callback
)
2557 return skb_copy_ubufs(skb
, gfp_mask
);
2560 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
2561 static inline int skb_orphan_frags_rx(struct sk_buff
*skb
, gfp_t gfp_mask
)
2563 if (likely(!skb_zcopy(skb
)))
2565 return skb_copy_ubufs(skb
, gfp_mask
);
2569 * __skb_queue_purge - empty a list
2570 * @list: list to empty
2572 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2573 * the list and one reference dropped. This function does not take the
2574 * list lock and the caller must hold the relevant locks to use it.
2576 void skb_queue_purge(struct sk_buff_head
*list
);
2577 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2579 struct sk_buff
*skb
;
2580 while ((skb
= __skb_dequeue(list
)) != NULL
)
2584 void skb_rbtree_purge(struct rb_root
*root
);
2586 void *netdev_alloc_frag(unsigned int fragsz
);
2588 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2592 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2593 * @dev: network device to receive on
2594 * @length: length to allocate
2596 * Allocate a new &sk_buff and assign it a usage count of one. The
2597 * buffer has unspecified headroom built in. Users should allocate
2598 * the headroom they think they need without accounting for the
2599 * built in space. The built in space is used for optimisations.
2601 * %NULL is returned if there is no free memory. Although this function
2602 * allocates memory it can be called from an interrupt.
2604 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2605 unsigned int length
)
2607 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2610 /* legacy helper around __netdev_alloc_skb() */
2611 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2614 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2617 /* legacy helper around netdev_alloc_skb() */
2618 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2620 return netdev_alloc_skb(NULL
, length
);
2624 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2625 unsigned int length
, gfp_t gfp
)
2627 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2629 if (NET_IP_ALIGN
&& skb
)
2630 skb_reserve(skb
, NET_IP_ALIGN
);
2634 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2635 unsigned int length
)
2637 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2640 static inline void skb_free_frag(void *addr
)
2642 page_frag_free(addr
);
2645 void *napi_alloc_frag(unsigned int fragsz
);
2646 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2647 unsigned int length
, gfp_t gfp_mask
);
2648 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2649 unsigned int length
)
2651 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2653 void napi_consume_skb(struct sk_buff
*skb
, int budget
);
2655 void __kfree_skb_flush(void);
2656 void __kfree_skb_defer(struct sk_buff
*skb
);
2659 * __dev_alloc_pages - allocate page for network Rx
2660 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2661 * @order: size of the allocation
2663 * Allocate a new page.
2665 * %NULL is returned if there is no free memory.
2667 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2670 /* This piece of code contains several assumptions.
2671 * 1. This is for device Rx, therefor a cold page is preferred.
2672 * 2. The expectation is the user wants a compound page.
2673 * 3. If requesting a order 0 page it will not be compound
2674 * due to the check to see if order has a value in prep_new_page
2675 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2676 * code in gfp_to_alloc_flags that should be enforcing this.
2678 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2680 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2683 static inline struct page
*dev_alloc_pages(unsigned int order
)
2685 return __dev_alloc_pages(GFP_ATOMIC
| __GFP_NOWARN
, order
);
2689 * __dev_alloc_page - allocate a page for network Rx
2690 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2692 * Allocate a new page.
2694 * %NULL is returned if there is no free memory.
2696 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2698 return __dev_alloc_pages(gfp_mask
, 0);
2701 static inline struct page
*dev_alloc_page(void)
2703 return dev_alloc_pages(0);
2707 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2708 * @page: The page that was allocated from skb_alloc_page
2709 * @skb: The skb that may need pfmemalloc set
2711 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2712 struct sk_buff
*skb
)
2714 if (page_is_pfmemalloc(page
))
2715 skb
->pfmemalloc
= true;
2719 * skb_frag_page - retrieve the page referred to by a paged fragment
2720 * @frag: the paged fragment
2722 * Returns the &struct page associated with @frag.
2724 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2726 return frag
->page
.p
;
2730 * __skb_frag_ref - take an addition reference on a paged fragment.
2731 * @frag: the paged fragment
2733 * Takes an additional reference on the paged fragment @frag.
2735 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2737 get_page(skb_frag_page(frag
));
2741 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2743 * @f: the fragment offset.
2745 * Takes an additional reference on the @f'th paged fragment of @skb.
2747 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2749 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2753 * __skb_frag_unref - release a reference on a paged fragment.
2754 * @frag: the paged fragment
2756 * Releases a reference on the paged fragment @frag.
2758 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2760 put_page(skb_frag_page(frag
));
2764 * skb_frag_unref - release a reference on a paged fragment of an skb.
2766 * @f: the fragment offset
2768 * Releases a reference on the @f'th paged fragment of @skb.
2770 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2772 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2776 * skb_frag_address - gets the address of the data contained in a paged fragment
2777 * @frag: the paged fragment buffer
2779 * Returns the address of the data within @frag. The page must already
2782 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2784 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2788 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2789 * @frag: the paged fragment buffer
2791 * Returns the address of the data within @frag. Checks that the page
2792 * is mapped and returns %NULL otherwise.
2794 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2796 void *ptr
= page_address(skb_frag_page(frag
));
2800 return ptr
+ frag
->page_offset
;
2804 * __skb_frag_set_page - sets the page contained in a paged fragment
2805 * @frag: the paged fragment
2806 * @page: the page to set
2808 * Sets the fragment @frag to contain @page.
2810 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2812 frag
->page
.p
= page
;
2816 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2818 * @f: the fragment offset
2819 * @page: the page to set
2821 * Sets the @f'th fragment of @skb to contain @page.
2823 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2826 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2829 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2832 * skb_frag_dma_map - maps a paged fragment via the DMA API
2833 * @dev: the device to map the fragment to
2834 * @frag: the paged fragment to map
2835 * @offset: the offset within the fragment (starting at the
2836 * fragment's own offset)
2837 * @size: the number of bytes to map
2838 * @dir: the direction of the mapping (``PCI_DMA_*``)
2840 * Maps the page associated with @frag to @device.
2842 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2843 const skb_frag_t
*frag
,
2844 size_t offset
, size_t size
,
2845 enum dma_data_direction dir
)
2847 return dma_map_page(dev
, skb_frag_page(frag
),
2848 frag
->page_offset
+ offset
, size
, dir
);
2851 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2854 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2858 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2861 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2866 * skb_clone_writable - is the header of a clone writable
2867 * @skb: buffer to check
2868 * @len: length up to which to write
2870 * Returns true if modifying the header part of the cloned buffer
2871 * does not requires the data to be copied.
2873 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2875 return !skb_header_cloned(skb
) &&
2876 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2879 static inline int skb_try_make_writable(struct sk_buff
*skb
,
2880 unsigned int write_len
)
2882 return skb_cloned(skb
) && !skb_clone_writable(skb
, write_len
) &&
2883 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
2886 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2891 if (headroom
> skb_headroom(skb
))
2892 delta
= headroom
- skb_headroom(skb
);
2894 if (delta
|| cloned
)
2895 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2901 * skb_cow - copy header of skb when it is required
2902 * @skb: buffer to cow
2903 * @headroom: needed headroom
2905 * If the skb passed lacks sufficient headroom or its data part
2906 * is shared, data is reallocated. If reallocation fails, an error
2907 * is returned and original skb is not changed.
2909 * The result is skb with writable area skb->head...skb->tail
2910 * and at least @headroom of space at head.
2912 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2914 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2918 * skb_cow_head - skb_cow but only making the head writable
2919 * @skb: buffer to cow
2920 * @headroom: needed headroom
2922 * This function is identical to skb_cow except that we replace the
2923 * skb_cloned check by skb_header_cloned. It should be used when
2924 * you only need to push on some header and do not need to modify
2927 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2929 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2933 * skb_padto - pad an skbuff up to a minimal size
2934 * @skb: buffer to pad
2935 * @len: minimal length
2937 * Pads up a buffer to ensure the trailing bytes exist and are
2938 * blanked. If the buffer already contains sufficient data it
2939 * is untouched. Otherwise it is extended. Returns zero on
2940 * success. The skb is freed on error.
2942 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2944 unsigned int size
= skb
->len
;
2945 if (likely(size
>= len
))
2947 return skb_pad(skb
, len
- size
);
2951 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2952 * @skb: buffer to pad
2953 * @len: minimal length
2954 * @free_on_error: free buffer on error
2956 * Pads up a buffer to ensure the trailing bytes exist and are
2957 * blanked. If the buffer already contains sufficient data it
2958 * is untouched. Otherwise it is extended. Returns zero on
2959 * success. The skb is freed on error if @free_on_error is true.
2961 static inline int __skb_put_padto(struct sk_buff
*skb
, unsigned int len
,
2964 unsigned int size
= skb
->len
;
2966 if (unlikely(size
< len
)) {
2968 if (__skb_pad(skb
, len
, free_on_error
))
2970 __skb_put(skb
, len
);
2976 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2977 * @skb: buffer to pad
2978 * @len: minimal length
2980 * Pads up a buffer to ensure the trailing bytes exist and are
2981 * blanked. If the buffer already contains sufficient data it
2982 * is untouched. Otherwise it is extended. Returns zero on
2983 * success. The skb is freed on error.
2985 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2987 return __skb_put_padto(skb
, len
, true);
2990 static inline int skb_add_data(struct sk_buff
*skb
,
2991 struct iov_iter
*from
, int copy
)
2993 const int off
= skb
->len
;
2995 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2997 if (csum_and_copy_from_iter_full(skb_put(skb
, copy
), copy
,
2999 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
3002 } else if (copy_from_iter_full(skb_put(skb
, copy
), copy
, from
))
3005 __skb_trim(skb
, off
);
3009 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
3010 const struct page
*page
, int off
)
3015 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
3017 return page
== skb_frag_page(frag
) &&
3018 off
== frag
->page_offset
+ skb_frag_size(frag
);
3023 static inline int __skb_linearize(struct sk_buff
*skb
)
3025 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
3029 * skb_linearize - convert paged skb to linear one
3030 * @skb: buffer to linarize
3032 * If there is no free memory -ENOMEM is returned, otherwise zero
3033 * is returned and the old skb data released.
3035 static inline int skb_linearize(struct sk_buff
*skb
)
3037 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
3041 * skb_has_shared_frag - can any frag be overwritten
3042 * @skb: buffer to test
3044 * Return true if the skb has at least one frag that might be modified
3045 * by an external entity (as in vmsplice()/sendfile())
3047 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
3049 return skb_is_nonlinear(skb
) &&
3050 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
3054 * skb_linearize_cow - make sure skb is linear and writable
3055 * @skb: buffer to process
3057 * If there is no free memory -ENOMEM is returned, otherwise zero
3058 * is returned and the old skb data released.
3060 static inline int skb_linearize_cow(struct sk_buff
*skb
)
3062 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
3063 __skb_linearize(skb
) : 0;
3066 static __always_inline
void
3067 __skb_postpull_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
3070 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3071 skb
->csum
= csum_block_sub(skb
->csum
,
3072 csum_partial(start
, len
, 0), off
);
3073 else if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3074 skb_checksum_start_offset(skb
) < 0)
3075 skb
->ip_summed
= CHECKSUM_NONE
;
3079 * skb_postpull_rcsum - update checksum for received skb after pull
3080 * @skb: buffer to update
3081 * @start: start of data before pull
3082 * @len: length of data pulled
3084 * After doing a pull on a received packet, you need to call this to
3085 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3086 * CHECKSUM_NONE so that it can be recomputed from scratch.
3088 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
3089 const void *start
, unsigned int len
)
3091 __skb_postpull_rcsum(skb
, start
, len
, 0);
3094 static __always_inline
void
3095 __skb_postpush_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
3098 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3099 skb
->csum
= csum_block_add(skb
->csum
,
3100 csum_partial(start
, len
, 0), off
);
3104 * skb_postpush_rcsum - update checksum for received skb after push
3105 * @skb: buffer to update
3106 * @start: start of data after push
3107 * @len: length of data pushed
3109 * After doing a push on a received packet, you need to call this to
3110 * update the CHECKSUM_COMPLETE checksum.
3112 static inline void skb_postpush_rcsum(struct sk_buff
*skb
,
3113 const void *start
, unsigned int len
)
3115 __skb_postpush_rcsum(skb
, start
, len
, 0);
3118 void *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
3121 * skb_push_rcsum - push skb and update receive checksum
3122 * @skb: buffer to update
3123 * @len: length of data pulled
3125 * This function performs an skb_push on the packet and updates
3126 * the CHECKSUM_COMPLETE checksum. It should be used on
3127 * receive path processing instead of skb_push unless you know
3128 * that the checksum difference is zero (e.g., a valid IP header)
3129 * or you are setting ip_summed to CHECKSUM_NONE.
3131 static inline void *skb_push_rcsum(struct sk_buff
*skb
, unsigned int len
)
3134 skb_postpush_rcsum(skb
, skb
->data
, len
);
3139 * pskb_trim_rcsum - trim received skb and update checksum
3140 * @skb: buffer to trim
3143 * This is exactly the same as pskb_trim except that it ensures the
3144 * checksum of received packets are still valid after the operation.
3147 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3149 if (likely(len
>= skb
->len
))
3151 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3152 skb
->ip_summed
= CHECKSUM_NONE
;
3153 return __pskb_trim(skb
, len
);
3156 static inline int __skb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3158 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3159 skb
->ip_summed
= CHECKSUM_NONE
;
3160 __skb_trim(skb
, len
);
3164 static inline int __skb_grow_rcsum(struct sk_buff
*skb
, unsigned int len
)
3166 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3167 skb
->ip_summed
= CHECKSUM_NONE
;
3168 return __skb_grow(skb
, len
);
3171 #define skb_queue_walk(queue, skb) \
3172 for (skb = (queue)->next; \
3173 skb != (struct sk_buff *)(queue); \
3176 #define skb_queue_walk_safe(queue, skb, tmp) \
3177 for (skb = (queue)->next, tmp = skb->next; \
3178 skb != (struct sk_buff *)(queue); \
3179 skb = tmp, tmp = skb->next)
3181 #define skb_queue_walk_from(queue, skb) \
3182 for (; skb != (struct sk_buff *)(queue); \
3185 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3186 for (tmp = skb->next; \
3187 skb != (struct sk_buff *)(queue); \
3188 skb = tmp, tmp = skb->next)
3190 #define skb_queue_reverse_walk(queue, skb) \
3191 for (skb = (queue)->prev; \
3192 skb != (struct sk_buff *)(queue); \
3195 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3196 for (skb = (queue)->prev, tmp = skb->prev; \
3197 skb != (struct sk_buff *)(queue); \
3198 skb = tmp, tmp = skb->prev)
3200 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3201 for (tmp = skb->prev; \
3202 skb != (struct sk_buff *)(queue); \
3203 skb = tmp, tmp = skb->prev)
3205 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
3207 return skb_shinfo(skb
)->frag_list
!= NULL
;
3210 static inline void skb_frag_list_init(struct sk_buff
*skb
)
3212 skb_shinfo(skb
)->frag_list
= NULL
;
3215 #define skb_walk_frags(skb, iter) \
3216 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3219 int __skb_wait_for_more_packets(struct sock
*sk
, int *err
, long *timeo_p
,
3220 const struct sk_buff
*skb
);
3221 struct sk_buff
*__skb_try_recv_from_queue(struct sock
*sk
,
3222 struct sk_buff_head
*queue
,
3224 void (*destructor
)(struct sock
*sk
,
3225 struct sk_buff
*skb
),
3226 int *peeked
, int *off
, int *err
,
3227 struct sk_buff
**last
);
3228 struct sk_buff
*__skb_try_recv_datagram(struct sock
*sk
, unsigned flags
,
3229 void (*destructor
)(struct sock
*sk
,
3230 struct sk_buff
*skb
),
3231 int *peeked
, int *off
, int *err
,
3232 struct sk_buff
**last
);
3233 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
3234 void (*destructor
)(struct sock
*sk
,
3235 struct sk_buff
*skb
),
3236 int *peeked
, int *off
, int *err
);
3237 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
3239 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
3240 struct poll_table_struct
*wait
);
3241 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
3242 struct iov_iter
*to
, int size
);
3243 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
3244 struct msghdr
*msg
, int size
)
3246 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
3248 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
3249 struct msghdr
*msg
);
3250 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
3251 struct iov_iter
*from
, int len
);
3252 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
3253 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
3254 void __skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
, int len
);
3255 static inline void skb_free_datagram_locked(struct sock
*sk
,
3256 struct sk_buff
*skb
)
3258 __skb_free_datagram_locked(sk
, skb
, 0);
3260 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
3261 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
3262 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
3263 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
3264 int len
, __wsum csum
);
3265 int skb_splice_bits(struct sk_buff
*skb
, struct sock
*sk
, unsigned int offset
,
3266 struct pipe_inode_info
*pipe
, unsigned int len
,
3267 unsigned int flags
);
3268 int skb_send_sock_locked(struct sock
*sk
, struct sk_buff
*skb
, int offset
,
3270 int skb_send_sock(struct sock
*sk
, struct sk_buff
*skb
, int offset
, int len
);
3271 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
3272 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
3273 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
3275 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
3276 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
3277 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
3278 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
3279 bool skb_gso_validate_mtu(const struct sk_buff
*skb
, unsigned int mtu
);
3280 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
3281 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
3282 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
3283 int __skb_vlan_pop(struct sk_buff
*skb
, u16
*vlan_tci
);
3284 int skb_vlan_pop(struct sk_buff
*skb
);
3285 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
3286 struct sk_buff
*pskb_extract(struct sk_buff
*skb
, int off
, int to_copy
,
3289 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
3291 return copy_from_iter_full(data
, len
, &msg
->msg_iter
) ? 0 : -EFAULT
;
3294 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
3296 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3299 struct skb_checksum_ops
{
3300 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
3301 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
3304 extern const struct skb_checksum_ops
*crc32c_csum_stub __read_mostly
;
3306 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3307 __wsum csum
, const struct skb_checksum_ops
*ops
);
3308 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3311 static inline void * __must_check
3312 __skb_header_pointer(const struct sk_buff
*skb
, int offset
,
3313 int len
, void *data
, int hlen
, void *buffer
)
3315 if (hlen
- offset
>= len
)
3316 return data
+ offset
;
3319 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
3325 static inline void * __must_check
3326 skb_header_pointer(const struct sk_buff
*skb
, int offset
, int len
, void *buffer
)
3328 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
3329 skb_headlen(skb
), buffer
);
3333 * skb_needs_linearize - check if we need to linearize a given skb
3334 * depending on the given device features.
3335 * @skb: socket buffer to check
3336 * @features: net device features
3338 * Returns true if either:
3339 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3340 * 2. skb is fragmented and the device does not support SG.
3342 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
3343 netdev_features_t features
)
3345 return skb_is_nonlinear(skb
) &&
3346 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
3347 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
3350 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
3352 const unsigned int len
)
3354 memcpy(to
, skb
->data
, len
);
3357 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
3358 const int offset
, void *to
,
3359 const unsigned int len
)
3361 memcpy(to
, skb
->data
+ offset
, len
);
3364 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
3366 const unsigned int len
)
3368 memcpy(skb
->data
, from
, len
);
3371 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
3374 const unsigned int len
)
3376 memcpy(skb
->data
+ offset
, from
, len
);
3379 void skb_init(void);
3381 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
3387 * skb_get_timestamp - get timestamp from a skb
3388 * @skb: skb to get stamp from
3389 * @stamp: pointer to struct timeval to store stamp in
3391 * Timestamps are stored in the skb as offsets to a base timestamp.
3392 * This function converts the offset back to a struct timeval and stores
3395 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
3396 struct timeval
*stamp
)
3398 *stamp
= ktime_to_timeval(skb
->tstamp
);
3401 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
3402 struct timespec
*stamp
)
3404 *stamp
= ktime_to_timespec(skb
->tstamp
);
3407 static inline void __net_timestamp(struct sk_buff
*skb
)
3409 skb
->tstamp
= ktime_get_real();
3412 static inline ktime_t
net_timedelta(ktime_t t
)
3414 return ktime_sub(ktime_get_real(), t
);
3417 static inline ktime_t
net_invalid_timestamp(void)
3422 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
3424 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3426 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
3427 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
3429 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3431 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
3435 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
3440 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3443 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3445 * PHY drivers may accept clones of transmitted packets for
3446 * timestamping via their phy_driver.txtstamp method. These drivers
3447 * must call this function to return the skb back to the stack with a
3450 * @skb: clone of the the original outgoing packet
3451 * @hwtstamps: hardware time stamps
3454 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
3455 struct skb_shared_hwtstamps
*hwtstamps
);
3457 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
3458 struct skb_shared_hwtstamps
*hwtstamps
,
3459 struct sock
*sk
, int tstype
);
3462 * skb_tstamp_tx - queue clone of skb with send time stamps
3463 * @orig_skb: the original outgoing packet
3464 * @hwtstamps: hardware time stamps, may be NULL if not available
3466 * If the skb has a socket associated, then this function clones the
3467 * skb (thus sharing the actual data and optional structures), stores
3468 * the optional hardware time stamping information (if non NULL) or
3469 * generates a software time stamp (otherwise), then queues the clone
3470 * to the error queue of the socket. Errors are silently ignored.
3472 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
3473 struct skb_shared_hwtstamps
*hwtstamps
);
3476 * skb_tx_timestamp() - Driver hook for transmit timestamping
3478 * Ethernet MAC Drivers should call this function in their hard_xmit()
3479 * function immediately before giving the sk_buff to the MAC hardware.
3481 * Specifically, one should make absolutely sure that this function is
3482 * called before TX completion of this packet can trigger. Otherwise
3483 * the packet could potentially already be freed.
3485 * @skb: A socket buffer.
3487 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
3489 skb_clone_tx_timestamp(skb
);
3490 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
)
3491 skb_tstamp_tx(skb
, NULL
);
3495 * skb_complete_wifi_ack - deliver skb with wifi status
3497 * @skb: the original outgoing packet
3498 * @acked: ack status
3501 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
3503 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
3504 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
3506 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
3508 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
3510 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3511 skb_checksum_start_offset(skb
) >= 0));
3515 * skb_checksum_complete - Calculate checksum of an entire packet
3516 * @skb: packet to process
3518 * This function calculates the checksum over the entire packet plus
3519 * the value of skb->csum. The latter can be used to supply the
3520 * checksum of a pseudo header as used by TCP/UDP. It returns the
3523 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3524 * this function can be used to verify that checksum on received
3525 * packets. In that case the function should return zero if the
3526 * checksum is correct. In particular, this function will return zero
3527 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3528 * hardware has already verified the correctness of the checksum.
3530 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
3532 return skb_csum_unnecessary(skb
) ?
3533 0 : __skb_checksum_complete(skb
);
3536 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
3538 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3539 if (skb
->csum_level
== 0)
3540 skb
->ip_summed
= CHECKSUM_NONE
;
3546 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
3548 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3549 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
3551 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
3552 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
3553 skb
->csum_level
= 0;
3557 /* Check if we need to perform checksum complete validation.
3559 * Returns true if checksum complete is needed, false otherwise
3560 * (either checksum is unnecessary or zero checksum is allowed).
3562 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3566 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3567 skb
->csum_valid
= 1;
3568 __skb_decr_checksum_unnecessary(skb
);
3575 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3578 #define CHECKSUM_BREAK 76
3580 /* Unset checksum-complete
3582 * Unset checksum complete can be done when packet is being modified
3583 * (uncompressed for instance) and checksum-complete value is
3586 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3588 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3589 skb
->ip_summed
= CHECKSUM_NONE
;
3592 /* Validate (init) checksum based on checksum complete.
3595 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3596 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3597 * checksum is stored in skb->csum for use in __skb_checksum_complete
3598 * non-zero: value of invalid checksum
3601 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3605 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3606 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3607 skb
->csum_valid
= 1;
3614 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3617 csum
= __skb_checksum_complete(skb
);
3618 skb
->csum_valid
= !csum
;
3625 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3630 /* Perform checksum validate (init). Note that this is a macro since we only
3631 * want to calculate the pseudo header which is an input function if necessary.
3632 * First we try to validate without any computation (checksum unnecessary) and
3633 * then calculate based on checksum complete calling the function to compute
3637 * 0: checksum is validated or try to in skb_checksum_complete
3638 * non-zero: value of invalid checksum
3640 #define __skb_checksum_validate(skb, proto, complete, \
3641 zero_okay, check, compute_pseudo) \
3643 __sum16 __ret = 0; \
3644 skb->csum_valid = 0; \
3645 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3646 __ret = __skb_checksum_validate_complete(skb, \
3647 complete, compute_pseudo(skb, proto)); \
3651 #define skb_checksum_init(skb, proto, compute_pseudo) \
3652 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3654 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3655 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3657 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3658 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3660 #define skb_checksum_validate_zero_check(skb, proto, check, \
3662 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3664 #define skb_checksum_simple_validate(skb) \
3665 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3667 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3669 return (skb
->ip_summed
== CHECKSUM_NONE
&& skb
->csum_valid
);
3672 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3673 __sum16 check
, __wsum pseudo
)
3675 skb
->csum
= ~pseudo
;
3676 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3679 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3681 if (__skb_checksum_convert_check(skb)) \
3682 __skb_checksum_convert(skb, check, \
3683 compute_pseudo(skb, proto)); \
3686 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3687 u16 start
, u16 offset
)
3689 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3690 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3691 skb
->csum_offset
= offset
- start
;
3694 /* Update skbuf and packet to reflect the remote checksum offload operation.
3695 * When called, ptr indicates the starting point for skb->csum when
3696 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3697 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3699 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3700 int start
, int offset
, bool nopartial
)
3705 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3709 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3710 __skb_checksum_complete(skb
);
3711 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3714 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3716 /* Adjust skb->csum since we changed the packet */
3717 skb
->csum
= csum_add(skb
->csum
, delta
);
3720 static inline struct nf_conntrack
*skb_nfct(const struct sk_buff
*skb
)
3722 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3723 return (void *)(skb
->_nfct
& SKB_NFCT_PTRMASK
);
3729 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3730 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3731 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3733 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3734 nf_conntrack_destroy(nfct
);
3736 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3739 atomic_inc(&nfct
->use
);
3742 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3743 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3745 if (nf_bridge
&& refcount_dec_and_test(&nf_bridge
->use
))
3748 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3751 refcount_inc(&nf_bridge
->use
);
3753 #endif /* CONFIG_BRIDGE_NETFILTER */
3754 static inline void nf_reset(struct sk_buff
*skb
)
3756 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3757 nf_conntrack_put(skb_nfct(skb
));
3760 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3761 nf_bridge_put(skb
->nf_bridge
);
3762 skb
->nf_bridge
= NULL
;
3766 static inline void nf_reset_trace(struct sk_buff
*skb
)
3768 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3773 static inline void ipvs_reset(struct sk_buff
*skb
)
3775 #if IS_ENABLED(CONFIG_IP_VS)
3776 skb
->ipvs_property
= 0;
3780 /* Note: This doesn't put any conntrack and bridge info in dst. */
3781 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3784 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3785 dst
->_nfct
= src
->_nfct
;
3786 nf_conntrack_get(skb_nfct(src
));
3788 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3789 dst
->nf_bridge
= src
->nf_bridge
;
3790 nf_bridge_get(src
->nf_bridge
);
3792 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3794 dst
->nf_trace
= src
->nf_trace
;
3798 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3800 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3801 nf_conntrack_put(skb_nfct(dst
));
3803 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3804 nf_bridge_put(dst
->nf_bridge
);
3806 __nf_copy(dst
, src
, true);
3809 #ifdef CONFIG_NETWORK_SECMARK
3810 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3812 to
->secmark
= from
->secmark
;
3815 static inline void skb_init_secmark(struct sk_buff
*skb
)
3820 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3823 static inline void skb_init_secmark(struct sk_buff
*skb
)
3827 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3829 return !skb
->destructor
&&
3830 #if IS_ENABLED(CONFIG_XFRM)
3834 !skb
->_skb_refdst
&&
3835 !skb_has_frag_list(skb
);
3838 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3840 skb
->queue_mapping
= queue_mapping
;
3843 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3845 return skb
->queue_mapping
;
3848 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3850 to
->queue_mapping
= from
->queue_mapping
;
3853 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3855 skb
->queue_mapping
= rx_queue
+ 1;
3858 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3860 return skb
->queue_mapping
- 1;
3863 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3865 return skb
->queue_mapping
!= 0;
3868 static inline void skb_set_dst_pending_confirm(struct sk_buff
*skb
, u32 val
)
3870 skb
->dst_pending_confirm
= val
;
3873 static inline bool skb_get_dst_pending_confirm(const struct sk_buff
*skb
)
3875 return skb
->dst_pending_confirm
!= 0;
3878 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3887 /* Keeps track of mac header offset relative to skb->head.
3888 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3889 * For non-tunnel skb it points to skb_mac_header() and for
3890 * tunnel skb it points to outer mac header.
3891 * Keeps track of level of encapsulation of network headers.
3902 #define SKB_SGO_CB_OFFSET 32
3903 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
3905 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3907 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3908 SKB_GSO_CB(inner_skb
)->mac_offset
;
3911 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3913 int new_headroom
, headroom
;
3916 headroom
= skb_headroom(skb
);
3917 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3921 new_headroom
= skb_headroom(skb
);
3922 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3926 static inline void gso_reset_checksum(struct sk_buff
*skb
, __wsum res
)
3928 /* Do not update partial checksums if remote checksum is enabled. */
3929 if (skb
->remcsum_offload
)
3932 SKB_GSO_CB(skb
)->csum
= res
;
3933 SKB_GSO_CB(skb
)->csum_start
= skb_checksum_start(skb
) - skb
->head
;
3936 /* Compute the checksum for a gso segment. First compute the checksum value
3937 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3938 * then add in skb->csum (checksum from csum_start to end of packet).
3939 * skb->csum and csum_start are then updated to reflect the checksum of the
3940 * resultant packet starting from the transport header-- the resultant checksum
3941 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3944 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3946 unsigned char *csum_start
= skb_transport_header(skb
);
3947 int plen
= (skb
->head
+ SKB_GSO_CB(skb
)->csum_start
) - csum_start
;
3948 __wsum partial
= SKB_GSO_CB(skb
)->csum
;
3950 SKB_GSO_CB(skb
)->csum
= res
;
3951 SKB_GSO_CB(skb
)->csum_start
= csum_start
- skb
->head
;
3953 return csum_fold(csum_partial(csum_start
, plen
, partial
));
3956 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3958 return skb_shinfo(skb
)->gso_size
;
3961 /* Note: Should be called only if skb_is_gso(skb) is true */
3962 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3964 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3967 static inline void skb_gso_reset(struct sk_buff
*skb
)
3969 skb_shinfo(skb
)->gso_size
= 0;
3970 skb_shinfo(skb
)->gso_segs
= 0;
3971 skb_shinfo(skb
)->gso_type
= 0;
3974 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3976 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3978 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3979 * wanted then gso_type will be set. */
3980 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3982 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3983 unlikely(shinfo
->gso_type
== 0)) {
3984 __skb_warn_lro_forwarding(skb
);
3990 static inline void skb_forward_csum(struct sk_buff
*skb
)
3992 /* Unfortunately we don't support this one. Any brave souls? */
3993 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3994 skb
->ip_summed
= CHECKSUM_NONE
;
3998 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3999 * @skb: skb to check
4001 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4002 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4003 * use this helper, to document places where we make this assertion.
4005 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
4008 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
4012 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
4014 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
4015 struct sk_buff
*skb_checksum_trimmed(struct sk_buff
*skb
,
4016 unsigned int transport_len
,
4017 __sum16(*skb_chkf
)(struct sk_buff
*skb
));
4020 * skb_head_is_locked - Determine if the skb->head is locked down
4021 * @skb: skb to check
4023 * The head on skbs build around a head frag can be removed if they are
4024 * not cloned. This function returns true if the skb head is locked down
4025 * due to either being allocated via kmalloc, or by being a clone with
4026 * multiple references to the head.
4028 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
4030 return !skb
->head_frag
|| skb_cloned(skb
);
4034 * skb_gso_network_seglen - Return length of individual segments of a gso packet
4038 * skb_gso_network_seglen is used to determine the real size of the
4039 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
4041 * The MAC/L2 header is not accounted for.
4043 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
4045 unsigned int hdr_len
= skb_transport_header(skb
) -
4046 skb_network_header(skb
);
4047 return hdr_len
+ skb_gso_transport_seglen(skb
);
4050 /* Local Checksum Offload.
4051 * Compute outer checksum based on the assumption that the
4052 * inner checksum will be offloaded later.
4053 * See Documentation/networking/checksum-offloads.txt for
4054 * explanation of how this works.
4055 * Fill in outer checksum adjustment (e.g. with sum of outer
4056 * pseudo-header) before calling.
4057 * Also ensure that inner checksum is in linear data area.
4059 static inline __wsum
lco_csum(struct sk_buff
*skb
)
4061 unsigned char *csum_start
= skb_checksum_start(skb
);
4062 unsigned char *l4_hdr
= skb_transport_header(skb
);
4065 /* Start with complement of inner checksum adjustment */
4066 partial
= ~csum_unfold(*(__force __sum16
*)(csum_start
+
4069 /* Add in checksum of our headers (incl. outer checksum
4070 * adjustment filled in by caller) and return result.
4072 return csum_partial(l4_hdr
, csum_start
- l4_hdr
, partial
);
4075 #endif /* __KERNEL__ */
4076 #endif /* _LINUX_SKBUFF_H */