2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
23 #include <linux/rbtree.h>
24 #include <linux/socket.h>
26 #include <linux/atomic.h>
27 #include <asm/types.h>
28 #include <linux/spinlock.h>
29 #include <linux/net.h>
30 #include <linux/textsearch.h>
31 #include <net/checksum.h>
32 #include <linux/rcupdate.h>
33 #include <linux/hrtimer.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/netdev_features.h>
36 #include <linux/sched.h>
37 #include <linux/sched/clock.h>
38 #include <net/flow_dissector.h>
39 #include <linux/splice.h>
40 #include <linux/in6.h>
41 #include <linux/if_packet.h>
44 /* The interface for checksum offload between the stack and networking drivers
47 * A. IP checksum related features
49 * Drivers advertise checksum offload capabilities in the features of a device.
50 * From the stack's point of view these are capabilities offered by the driver,
51 * a driver typically only advertises features that it is capable of offloading
54 * The checksum related features are:
56 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
57 * IP (one's complement) checksum for any combination
58 * of protocols or protocol layering. The checksum is
59 * computed and set in a packet per the CHECKSUM_PARTIAL
60 * interface (see below).
62 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
63 * TCP or UDP packets over IPv4. These are specifically
64 * unencapsulated packets of the form IPv4|TCP or
65 * IPv4|UDP where the Protocol field in the IPv4 header
66 * is TCP or UDP. The IPv4 header may contain IP options
67 * This feature cannot be set in features for a device
68 * with NETIF_F_HW_CSUM also set. This feature is being
69 * DEPRECATED (see below).
71 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
72 * TCP or UDP packets over IPv6. These are specifically
73 * unencapsulated packets of the form IPv6|TCP or
74 * IPv4|UDP where the Next Header field in the IPv6
75 * header is either TCP or UDP. IPv6 extension headers
76 * are not supported with this feature. This feature
77 * cannot be set in features for a device with
78 * NETIF_F_HW_CSUM also set. This feature is being
79 * DEPRECATED (see below).
81 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
82 * This flag is used only used to disable the RX checksum
83 * feature for a device. The stack will accept receive
84 * checksum indication in packets received on a device
85 * regardless of whether NETIF_F_RXCSUM is set.
87 * B. Checksumming of received packets by device. Indication of checksum
88 * verification is in set skb->ip_summed. Possible values are:
92 * Device did not checksum this packet e.g. due to lack of capabilities.
93 * The packet contains full (though not verified) checksum in packet but
94 * not in skb->csum. Thus, skb->csum is undefined in this case.
96 * CHECKSUM_UNNECESSARY:
98 * The hardware you're dealing with doesn't calculate the full checksum
99 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
100 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
101 * if their checksums are okay. skb->csum is still undefined in this case
102 * though. A driver or device must never modify the checksum field in the
103 * packet even if checksum is verified.
105 * CHECKSUM_UNNECESSARY is applicable to following protocols:
106 * TCP: IPv6 and IPv4.
107 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
108 * zero UDP checksum for either IPv4 or IPv6, the networking stack
109 * may perform further validation in this case.
110 * GRE: only if the checksum is present in the header.
111 * SCTP: indicates the CRC in SCTP header has been validated.
112 * FCOE: indicates the CRC in FC frame has been validated.
114 * skb->csum_level indicates the number of consecutive checksums found in
115 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
116 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
117 * and a device is able to verify the checksums for UDP (possibly zero),
118 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
119 * two. If the device were only able to verify the UDP checksum and not
120 * GRE, either because it doesn't support GRE checksum of because GRE
121 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
122 * not considered in this case).
126 * This is the most generic way. The device supplied checksum of the _whole_
127 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
128 * hardware doesn't need to parse L3/L4 headers to implement this.
131 * - Even if device supports only some protocols, but is able to produce
132 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
133 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
137 * A checksum is set up to be offloaded to a device as described in the
138 * output description for CHECKSUM_PARTIAL. This may occur on a packet
139 * received directly from another Linux OS, e.g., a virtualized Linux kernel
140 * on the same host, or it may be set in the input path in GRO or remote
141 * checksum offload. For the purposes of checksum verification, the checksum
142 * referred to by skb->csum_start + skb->csum_offset and any preceding
143 * checksums in the packet are considered verified. Any checksums in the
144 * packet that are after the checksum being offloaded are not considered to
147 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
148 * in the skb->ip_summed for a packet. Values are:
152 * The driver is required to checksum the packet as seen by hard_start_xmit()
153 * from skb->csum_start up to the end, and to record/write the checksum at
154 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
155 * csum_start and csum_offset values are valid values given the length and
156 * offset of the packet, however they should not attempt to validate that the
157 * checksum refers to a legitimate transport layer checksum-- it is the
158 * purview of the stack to validate that csum_start and csum_offset are set
161 * When the stack requests checksum offload for a packet, the driver MUST
162 * ensure that the checksum is set correctly. A driver can either offload the
163 * checksum calculation to the device, or call skb_checksum_help (in the case
164 * that the device does not support offload for a particular checksum).
166 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
167 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
168 * checksum offload capability.
169 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
170 * on network device checksumming capabilities: if a packet does not match
171 * them, skb_checksum_help or skb_crc32c_help (depending on the value of
172 * csum_not_inet, see item D.) is called to resolve the checksum.
176 * The skb was already checksummed by the protocol, or a checksum is not
179 * CHECKSUM_UNNECESSARY:
181 * This has the same meaning on as CHECKSUM_NONE for checksum offload on
185 * Not used in checksum output. If a driver observes a packet with this value
186 * set in skbuff, if should treat as CHECKSUM_NONE being set.
188 * D. Non-IP checksum (CRC) offloads
190 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
191 * offloading the SCTP CRC in a packet. To perform this offload the stack
192 * will set set csum_start and csum_offset accordingly, set ip_summed to
193 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
194 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
195 * A driver that supports both IP checksum offload and SCTP CRC32c offload
196 * must verify which offload is configured for a packet by testing the
197 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
198 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
200 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
201 * offloading the FCOE CRC in a packet. To perform this offload the stack
202 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
203 * accordingly. Note the there is no indication in the skbuff that the
204 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
205 * both IP checksum offload and FCOE CRC offload must verify which offload
206 * is configured for a packet presumably by inspecting packet headers.
208 * E. Checksumming on output with GSO.
210 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
211 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
212 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
213 * part of the GSO operation is implied. If a checksum is being offloaded
214 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
215 * are set to refer to the outermost checksum being offload (two offloaded
216 * checksums are possible with UDP encapsulation).
219 /* Don't change this without changing skb_csum_unnecessary! */
220 #define CHECKSUM_NONE 0
221 #define CHECKSUM_UNNECESSARY 1
222 #define CHECKSUM_COMPLETE 2
223 #define CHECKSUM_PARTIAL 3
225 /* Maximum value in skb->csum_level */
226 #define SKB_MAX_CSUM_LEVEL 3
228 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
229 #define SKB_WITH_OVERHEAD(X) \
230 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
231 #define SKB_MAX_ORDER(X, ORDER) \
232 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
233 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
234 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
236 /* return minimum truesize of one skb containing X bytes of data */
237 #define SKB_TRUESIZE(X) ((X) + \
238 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
239 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
243 struct pipe_inode_info
;
247 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
248 struct nf_conntrack
{
253 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
254 struct nf_bridge_info
{
257 BRNF_PROTO_UNCHANGED
,
265 struct net_device
*physindev
;
267 /* always valid & non-NULL from FORWARD on, for physdev match */
268 struct net_device
*physoutdev
;
270 /* prerouting: detect dnat in orig/reply direction */
272 struct in6_addr ipv6_daddr
;
274 /* after prerouting + nat detected: store original source
275 * mac since neigh resolution overwrites it, only used while
276 * skb is out in neigh layer.
278 char neigh_header
[8];
283 struct sk_buff_head
{
284 /* These two members must be first. */
285 struct sk_buff
*next
;
286 struct sk_buff
*prev
;
294 /* To allow 64K frame to be packed as single skb without frag_list we
295 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
296 * buffers which do not start on a page boundary.
298 * Since GRO uses frags we allocate at least 16 regardless of page
301 #if (65536/PAGE_SIZE + 1) < 16
302 #define MAX_SKB_FRAGS 16UL
304 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
306 extern int sysctl_max_skb_frags
;
308 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
309 * segment using its current segmentation instead.
311 #define GSO_BY_FRAGS 0xFFFF
313 typedef struct skb_frag_struct skb_frag_t
;
315 struct skb_frag_struct
{
319 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
328 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
333 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
338 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
343 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
348 #define HAVE_HW_TIME_STAMP
351 * struct skb_shared_hwtstamps - hardware time stamps
352 * @hwtstamp: hardware time stamp transformed into duration
353 * since arbitrary point in time
355 * Software time stamps generated by ktime_get_real() are stored in
358 * hwtstamps can only be compared against other hwtstamps from
361 * This structure is attached to packets as part of the
362 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
364 struct skb_shared_hwtstamps
{
368 /* Definitions for tx_flags in struct skb_shared_info */
370 /* generate hardware time stamp */
371 SKBTX_HW_TSTAMP
= 1 << 0,
373 /* generate software time stamp when queueing packet to NIC */
374 SKBTX_SW_TSTAMP
= 1 << 1,
376 /* device driver is going to provide hardware time stamp */
377 SKBTX_IN_PROGRESS
= 1 << 2,
379 /* device driver supports TX zero-copy buffers */
380 SKBTX_DEV_ZEROCOPY
= 1 << 3,
382 /* generate wifi status information (where possible) */
383 SKBTX_WIFI_STATUS
= 1 << 4,
385 /* This indicates at least one fragment might be overwritten
386 * (as in vmsplice(), sendfile() ...)
387 * If we need to compute a TX checksum, we'll need to copy
388 * all frags to avoid possible bad checksum
390 SKBTX_SHARED_FRAG
= 1 << 5,
392 /* generate software time stamp when entering packet scheduling */
393 SKBTX_SCHED_TSTAMP
= 1 << 6,
396 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
398 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
401 * The callback notifies userspace to release buffers when skb DMA is done in
402 * lower device, the skb last reference should be 0 when calling this.
403 * The zerocopy_success argument is true if zero copy transmit occurred,
404 * false on data copy or out of memory error caused by data copy attempt.
405 * The ctx field is used to track device context.
406 * The desc field is used to track userspace buffer index.
409 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
414 /* This data is invariant across clones and lives at
415 * the end of the header data, ie. at skb->end.
417 struct skb_shared_info
{
418 unsigned short _unused
;
419 unsigned char nr_frags
;
421 unsigned short gso_size
;
422 /* Warning: this field is not always filled in (UFO)! */
423 unsigned short gso_segs
;
424 struct sk_buff
*frag_list
;
425 struct skb_shared_hwtstamps hwtstamps
;
426 unsigned int gso_type
;
431 * Warning : all fields before dataref are cleared in __alloc_skb()
435 /* Intermediate layers must ensure that destructor_arg
436 * remains valid until skb destructor */
437 void * destructor_arg
;
439 /* must be last field, see pskb_expand_head() */
440 skb_frag_t frags
[MAX_SKB_FRAGS
];
443 /* We divide dataref into two halves. The higher 16 bits hold references
444 * to the payload part of skb->data. The lower 16 bits hold references to
445 * the entire skb->data. A clone of a headerless skb holds the length of
446 * the header in skb->hdr_len.
448 * All users must obey the rule that the skb->data reference count must be
449 * greater than or equal to the payload reference count.
451 * Holding a reference to the payload part means that the user does not
452 * care about modifications to the header part of skb->data.
454 #define SKB_DATAREF_SHIFT 16
455 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
459 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
460 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
461 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
465 SKB_GSO_TCPV4
= 1 << 0,
466 SKB_GSO_UDP
= 1 << 1,
468 /* This indicates the skb is from an untrusted source. */
469 SKB_GSO_DODGY
= 1 << 2,
471 /* This indicates the tcp segment has CWR set. */
472 SKB_GSO_TCP_ECN
= 1 << 3,
474 SKB_GSO_TCP_FIXEDID
= 1 << 4,
476 SKB_GSO_TCPV6
= 1 << 5,
478 SKB_GSO_FCOE
= 1 << 6,
480 SKB_GSO_GRE
= 1 << 7,
482 SKB_GSO_GRE_CSUM
= 1 << 8,
484 SKB_GSO_IPXIP4
= 1 << 9,
486 SKB_GSO_IPXIP6
= 1 << 10,
488 SKB_GSO_UDP_TUNNEL
= 1 << 11,
490 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 12,
492 SKB_GSO_PARTIAL
= 1 << 13,
494 SKB_GSO_TUNNEL_REMCSUM
= 1 << 14,
496 SKB_GSO_SCTP
= 1 << 15,
498 SKB_GSO_ESP
= 1 << 16,
501 #if BITS_PER_LONG > 32
502 #define NET_SKBUFF_DATA_USES_OFFSET 1
505 #ifdef NET_SKBUFF_DATA_USES_OFFSET
506 typedef unsigned int sk_buff_data_t
;
508 typedef unsigned char *sk_buff_data_t
;
512 * struct sk_buff - socket buffer
513 * @next: Next buffer in list
514 * @prev: Previous buffer in list
515 * @tstamp: Time we arrived/left
516 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
517 * @sk: Socket we are owned by
518 * @dev: Device we arrived on/are leaving by
519 * @cb: Control buffer. Free for use by every layer. Put private vars here
520 * @_skb_refdst: destination entry (with norefcount bit)
521 * @sp: the security path, used for xfrm
522 * @len: Length of actual data
523 * @data_len: Data length
524 * @mac_len: Length of link layer header
525 * @hdr_len: writable header length of cloned skb
526 * @csum: Checksum (must include start/offset pair)
527 * @csum_start: Offset from skb->head where checksumming should start
528 * @csum_offset: Offset from csum_start where checksum should be stored
529 * @priority: Packet queueing priority
530 * @ignore_df: allow local fragmentation
531 * @cloned: Head may be cloned (check refcnt to be sure)
532 * @ip_summed: Driver fed us an IP checksum
533 * @nohdr: Payload reference only, must not modify header
534 * @pkt_type: Packet class
535 * @fclone: skbuff clone status
536 * @ipvs_property: skbuff is owned by ipvs
537 * @tc_skip_classify: do not classify packet. set by IFB device
538 * @tc_at_ingress: used within tc_classify to distinguish in/egress
539 * @tc_redirected: packet was redirected by a tc action
540 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect
541 * @peeked: this packet has been seen already, so stats have been
542 * done for it, don't do them again
543 * @nf_trace: netfilter packet trace flag
544 * @protocol: Packet protocol from driver
545 * @destructor: Destruct function
546 * @_nfct: Associated connection, if any (with nfctinfo bits)
547 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
548 * @skb_iif: ifindex of device we arrived on
549 * @tc_index: Traffic control index
550 * @hash: the packet hash
551 * @queue_mapping: Queue mapping for multiqueue devices
552 * @xmit_more: More SKBs are pending for this queue
553 * @ndisc_nodetype: router type (from link layer)
554 * @ooo_okay: allow the mapping of a socket to a queue to be changed
555 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
557 * @sw_hash: indicates hash was computed in software stack
558 * @wifi_acked_valid: wifi_acked was set
559 * @wifi_acked: whether frame was acked on wifi or not
560 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
561 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
562 * @dst_pending_confirm: need to confirm neighbour
563 * @napi_id: id of the NAPI struct this skb came from
564 * @secmark: security marking
565 * @mark: Generic packet mark
566 * @vlan_proto: vlan encapsulation protocol
567 * @vlan_tci: vlan tag control information
568 * @inner_protocol: Protocol (encapsulation)
569 * @inner_transport_header: Inner transport layer header (encapsulation)
570 * @inner_network_header: Network layer header (encapsulation)
571 * @inner_mac_header: Link layer header (encapsulation)
572 * @transport_header: Transport layer header
573 * @network_header: Network layer header
574 * @mac_header: Link layer header
575 * @tail: Tail pointer
577 * @head: Head of buffer
578 * @data: Data head pointer
579 * @truesize: Buffer size
580 * @users: User count - see {datagram,tcp}.c
586 /* These two members must be first. */
587 struct sk_buff
*next
;
588 struct sk_buff
*prev
;
595 struct rb_node rbnode
; /* used in netem & tcp stack */
600 struct net_device
*dev
;
601 /* Some protocols might use this space to store information,
602 * while device pointer would be NULL.
603 * UDP receive path is one user.
605 unsigned long dev_scratch
;
608 * This is the control buffer. It is free to use for every
609 * layer. Please put your private variables there. If you
610 * want to keep them across layers you have to do a skb_clone()
611 * first. This is owned by whoever has the skb queued ATM.
613 char cb
[48] __aligned(8);
615 unsigned long _skb_refdst
;
616 void (*destructor
)(struct sk_buff
*skb
);
620 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
623 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
624 struct nf_bridge_info
*nf_bridge
;
631 /* Following fields are _not_ copied in __copy_skb_header()
632 * Note that queue_mapping is here mostly to fill a hole.
634 kmemcheck_bitfield_begin(flags1
);
637 /* if you move cloned around you also must adapt those constants */
638 #ifdef __BIG_ENDIAN_BITFIELD
639 #define CLONED_MASK (1 << 7)
641 #define CLONED_MASK 1
643 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
645 __u8 __cloned_offset
[0];
652 __unused
:1; /* one bit hole */
653 kmemcheck_bitfield_end(flags1
);
655 /* fields enclosed in headers_start/headers_end are copied
656 * using a single memcpy() in __copy_skb_header()
659 __u32 headers_start
[0];
662 /* if you move pkt_type around you also must adapt those constants */
663 #ifdef __BIG_ENDIAN_BITFIELD
664 #define PKT_TYPE_MAX (7 << 5)
666 #define PKT_TYPE_MAX 7
668 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
670 __u8 __pkt_type_offset
[0];
680 __u8 wifi_acked_valid
:1;
684 /* Indicates the inner headers are valid in the skbuff. */
685 __u8 encapsulation
:1;
686 __u8 encap_hdr_csum
:1;
688 __u8 csum_complete_sw
:1;
690 __u8 csum_not_inet
:1;
692 __u8 dst_pending_confirm
:1;
693 #ifdef CONFIG_IPV6_NDISC_NODETYPE
694 __u8 ndisc_nodetype
:2;
696 __u8 ipvs_property
:1;
697 __u8 inner_protocol_type
:1;
698 __u8 remcsum_offload
:1;
699 #ifdef CONFIG_NET_SWITCHDEV
700 __u8 offload_fwd_mark
:1;
702 #ifdef CONFIG_NET_CLS_ACT
703 __u8 tc_skip_classify
:1;
704 __u8 tc_at_ingress
:1;
705 __u8 tc_redirected
:1;
706 __u8 tc_from_ingress
:1;
709 #ifdef CONFIG_NET_SCHED
710 __u16 tc_index
; /* traffic control index */
725 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
727 unsigned int napi_id
;
728 unsigned int sender_cpu
;
731 #ifdef CONFIG_NETWORK_SECMARK
737 __u32 reserved_tailroom
;
741 __be16 inner_protocol
;
745 __u16 inner_transport_header
;
746 __u16 inner_network_header
;
747 __u16 inner_mac_header
;
750 __u16 transport_header
;
751 __u16 network_header
;
755 __u32 headers_end
[0];
758 /* These elements must be at the end, see alloc_skb() for details. */
763 unsigned int truesize
;
769 * Handling routines are only of interest to the kernel
771 #include <linux/slab.h>
774 #define SKB_ALLOC_FCLONE 0x01
775 #define SKB_ALLOC_RX 0x02
776 #define SKB_ALLOC_NAPI 0x04
778 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
779 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
781 return unlikely(skb
->pfmemalloc
);
785 * skb might have a dst pointer attached, refcounted or not.
786 * _skb_refdst low order bit is set if refcount was _not_ taken
788 #define SKB_DST_NOREF 1UL
789 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
791 #define SKB_NFCT_PTRMASK ~(7UL)
793 * skb_dst - returns skb dst_entry
796 * Returns skb dst_entry, regardless of reference taken or not.
798 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
800 /* If refdst was not refcounted, check we still are in a
801 * rcu_read_lock section
803 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
804 !rcu_read_lock_held() &&
805 !rcu_read_lock_bh_held());
806 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
810 * skb_dst_set - sets skb dst
814 * Sets skb dst, assuming a reference was taken on dst and should
815 * be released by skb_dst_drop()
817 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
819 skb
->_skb_refdst
= (unsigned long)dst
;
823 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
827 * Sets skb dst, assuming a reference was not taken on dst.
828 * If dst entry is cached, we do not take reference and dst_release
829 * will be avoided by refdst_drop. If dst entry is not cached, we take
830 * reference, so that last dst_release can destroy the dst immediately.
832 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
834 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
835 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
839 * skb_dst_is_noref - Test if skb dst isn't refcounted
842 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
844 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
847 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
849 return (struct rtable
*)skb_dst(skb
);
852 /* For mangling skb->pkt_type from user space side from applications
853 * such as nft, tc, etc, we only allow a conservative subset of
854 * possible pkt_types to be set.
856 static inline bool skb_pkt_type_ok(u32 ptype
)
858 return ptype
<= PACKET_OTHERHOST
;
861 static inline unsigned int skb_napi_id(const struct sk_buff
*skb
)
863 #ifdef CONFIG_NET_RX_BUSY_POLL
870 /* decrement the reference count and return true if we can free the skb */
871 static inline bool skb_unref(struct sk_buff
*skb
)
875 if (likely(refcount_read(&skb
->users
) == 1))
877 else if (likely(!refcount_dec_and_test(&skb
->users
)))
883 void skb_release_head_state(struct sk_buff
*skb
);
884 void kfree_skb(struct sk_buff
*skb
);
885 void kfree_skb_list(struct sk_buff
*segs
);
886 void skb_tx_error(struct sk_buff
*skb
);
887 void consume_skb(struct sk_buff
*skb
);
888 void __consume_stateless_skb(struct sk_buff
*skb
);
889 void __kfree_skb(struct sk_buff
*skb
);
890 extern struct kmem_cache
*skbuff_head_cache
;
892 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
893 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
894 bool *fragstolen
, int *delta_truesize
);
896 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
898 struct sk_buff
*__build_skb(void *data
, unsigned int frag_size
);
899 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
900 static inline struct sk_buff
*alloc_skb(unsigned int size
,
903 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
906 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
907 unsigned long data_len
,
912 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
913 struct sk_buff_fclones
{
918 refcount_t fclone_ref
;
922 * skb_fclone_busy - check if fclone is busy
926 * Returns true if skb is a fast clone, and its clone is not freed.
927 * Some drivers call skb_orphan() in their ndo_start_xmit(),
928 * so we also check that this didnt happen.
930 static inline bool skb_fclone_busy(const struct sock
*sk
,
931 const struct sk_buff
*skb
)
933 const struct sk_buff_fclones
*fclones
;
935 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
937 return skb
->fclone
== SKB_FCLONE_ORIG
&&
938 refcount_read(&fclones
->fclone_ref
) > 1 &&
939 fclones
->skb2
.sk
== sk
;
942 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
945 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
948 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
949 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
951 return __alloc_skb_head(priority
, -1);
954 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
955 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
956 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
957 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
958 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
959 gfp_t gfp_mask
, bool fclone
);
960 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
963 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
966 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
967 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
968 unsigned int headroom
);
969 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
970 int newtailroom
, gfp_t priority
);
971 int __must_check
skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
972 int offset
, int len
);
973 int __must_check
skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
,
974 int offset
, int len
);
975 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
976 int __skb_pad(struct sk_buff
*skb
, int pad
, bool free_on_error
);
979 * skb_pad - zero pad the tail of an skb
980 * @skb: buffer to pad
983 * Ensure that a buffer is followed by a padding area that is zero
984 * filled. Used by network drivers which may DMA or transfer data
985 * beyond the buffer end onto the wire.
987 * May return error in out of memory cases. The skb is freed on error.
989 static inline int skb_pad(struct sk_buff
*skb
, int pad
)
991 return __skb_pad(skb
, pad
, true);
993 #define dev_kfree_skb(a) consume_skb(a)
995 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
996 int getfrag(void *from
, char *to
, int offset
,
997 int len
, int odd
, struct sk_buff
*skb
),
998 void *from
, int length
);
1000 int skb_append_pagefrags(struct sk_buff
*skb
, struct page
*page
,
1001 int offset
, size_t size
);
1003 struct skb_seq_state
{
1007 __u32 stepped_offset
;
1008 struct sk_buff
*root_skb
;
1009 struct sk_buff
*cur_skb
;
1013 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1014 unsigned int to
, struct skb_seq_state
*st
);
1015 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1016 struct skb_seq_state
*st
);
1017 void skb_abort_seq_read(struct skb_seq_state
*st
);
1019 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1020 unsigned int to
, struct ts_config
*config
);
1023 * Packet hash types specify the type of hash in skb_set_hash.
1025 * Hash types refer to the protocol layer addresses which are used to
1026 * construct a packet's hash. The hashes are used to differentiate or identify
1027 * flows of the protocol layer for the hash type. Hash types are either
1028 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1030 * Properties of hashes:
1032 * 1) Two packets in different flows have different hash values
1033 * 2) Two packets in the same flow should have the same hash value
1035 * A hash at a higher layer is considered to be more specific. A driver should
1036 * set the most specific hash possible.
1038 * A driver cannot indicate a more specific hash than the layer at which a hash
1039 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1041 * A driver may indicate a hash level which is less specific than the
1042 * actual layer the hash was computed on. For instance, a hash computed
1043 * at L4 may be considered an L3 hash. This should only be done if the
1044 * driver can't unambiguously determine that the HW computed the hash at
1045 * the higher layer. Note that the "should" in the second property above
1048 enum pkt_hash_types
{
1049 PKT_HASH_TYPE_NONE
, /* Undefined type */
1050 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
1051 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
1052 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
1055 static inline void skb_clear_hash(struct sk_buff
*skb
)
1062 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
1065 skb_clear_hash(skb
);
1069 __skb_set_hash(struct sk_buff
*skb
, __u32 hash
, bool is_sw
, bool is_l4
)
1071 skb
->l4_hash
= is_l4
;
1072 skb
->sw_hash
= is_sw
;
1077 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
1079 /* Used by drivers to set hash from HW */
1080 __skb_set_hash(skb
, hash
, false, type
== PKT_HASH_TYPE_L4
);
1084 __skb_set_sw_hash(struct sk_buff
*skb
, __u32 hash
, bool is_l4
)
1086 __skb_set_hash(skb
, hash
, true, is_l4
);
1089 void __skb_get_hash(struct sk_buff
*skb
);
1090 u32
__skb_get_hash_symmetric(const struct sk_buff
*skb
);
1091 u32
skb_get_poff(const struct sk_buff
*skb
);
1092 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
1093 const struct flow_keys
*keys
, int hlen
);
1094 __be32
__skb_flow_get_ports(const struct sk_buff
*skb
, int thoff
, u8 ip_proto
,
1095 void *data
, int hlen_proto
);
1097 static inline __be32
skb_flow_get_ports(const struct sk_buff
*skb
,
1098 int thoff
, u8 ip_proto
)
1100 return __skb_flow_get_ports(skb
, thoff
, ip_proto
, NULL
, 0);
1103 void skb_flow_dissector_init(struct flow_dissector
*flow_dissector
,
1104 const struct flow_dissector_key
*key
,
1105 unsigned int key_count
);
1107 bool __skb_flow_dissect(const struct sk_buff
*skb
,
1108 struct flow_dissector
*flow_dissector
,
1109 void *target_container
,
1110 void *data
, __be16 proto
, int nhoff
, int hlen
,
1111 unsigned int flags
);
1113 static inline bool skb_flow_dissect(const struct sk_buff
*skb
,
1114 struct flow_dissector
*flow_dissector
,
1115 void *target_container
, unsigned int flags
)
1117 return __skb_flow_dissect(skb
, flow_dissector
, target_container
,
1118 NULL
, 0, 0, 0, flags
);
1121 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff
*skb
,
1122 struct flow_keys
*flow
,
1125 memset(flow
, 0, sizeof(*flow
));
1126 return __skb_flow_dissect(skb
, &flow_keys_dissector
, flow
,
1127 NULL
, 0, 0, 0, flags
);
1130 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys
*flow
,
1131 void *data
, __be16 proto
,
1132 int nhoff
, int hlen
,
1135 memset(flow
, 0, sizeof(*flow
));
1136 return __skb_flow_dissect(NULL
, &flow_keys_buf_dissector
, flow
,
1137 data
, proto
, nhoff
, hlen
, flags
);
1140 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
1142 if (!skb
->l4_hash
&& !skb
->sw_hash
)
1143 __skb_get_hash(skb
);
1148 __u32
__skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
);
1150 static inline __u32
skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
)
1152 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1153 struct flow_keys keys
;
1154 __u32 hash
= __get_hash_from_flowi6(fl6
, &keys
);
1156 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1162 __u32
__skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl
);
1164 static inline __u32
skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl4
)
1166 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1167 struct flow_keys keys
;
1168 __u32 hash
= __get_hash_from_flowi4(fl4
, &keys
);
1170 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1176 __u32
skb_get_hash_perturb(const struct sk_buff
*skb
, u32 perturb
);
1178 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
1183 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
1185 to
->hash
= from
->hash
;
1186 to
->sw_hash
= from
->sw_hash
;
1187 to
->l4_hash
= from
->l4_hash
;
1190 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1191 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1193 return skb
->head
+ skb
->end
;
1196 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1201 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1206 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1208 return skb
->end
- skb
->head
;
1213 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1215 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
1217 return &skb_shinfo(skb
)->hwtstamps
;
1221 * skb_queue_empty - check if a queue is empty
1224 * Returns true if the queue is empty, false otherwise.
1226 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1228 return list
->next
== (const struct sk_buff
*) list
;
1232 * skb_queue_is_last - check if skb is the last entry in the queue
1236 * Returns true if @skb is the last buffer on the list.
1238 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1239 const struct sk_buff
*skb
)
1241 return skb
->next
== (const struct sk_buff
*) list
;
1245 * skb_queue_is_first - check if skb is the first entry in the queue
1249 * Returns true if @skb is the first buffer on the list.
1251 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1252 const struct sk_buff
*skb
)
1254 return skb
->prev
== (const struct sk_buff
*) list
;
1258 * skb_queue_next - return the next packet in the queue
1260 * @skb: current buffer
1262 * Return the next packet in @list after @skb. It is only valid to
1263 * call this if skb_queue_is_last() evaluates to false.
1265 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1266 const struct sk_buff
*skb
)
1268 /* This BUG_ON may seem severe, but if we just return then we
1269 * are going to dereference garbage.
1271 BUG_ON(skb_queue_is_last(list
, skb
));
1276 * skb_queue_prev - return the prev packet in the queue
1278 * @skb: current buffer
1280 * Return the prev packet in @list before @skb. It is only valid to
1281 * call this if skb_queue_is_first() evaluates to false.
1283 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1284 const struct sk_buff
*skb
)
1286 /* This BUG_ON may seem severe, but if we just return then we
1287 * are going to dereference garbage.
1289 BUG_ON(skb_queue_is_first(list
, skb
));
1294 * skb_get - reference buffer
1295 * @skb: buffer to reference
1297 * Makes another reference to a socket buffer and returns a pointer
1300 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1302 refcount_inc(&skb
->users
);
1307 * If users == 1, we are the only owner and are can avoid redundant
1312 * skb_cloned - is the buffer a clone
1313 * @skb: buffer to check
1315 * Returns true if the buffer was generated with skb_clone() and is
1316 * one of multiple shared copies of the buffer. Cloned buffers are
1317 * shared data so must not be written to under normal circumstances.
1319 static inline int skb_cloned(const struct sk_buff
*skb
)
1321 return skb
->cloned
&&
1322 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1325 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1327 might_sleep_if(gfpflags_allow_blocking(pri
));
1329 if (skb_cloned(skb
))
1330 return pskb_expand_head(skb
, 0, 0, pri
);
1336 * skb_header_cloned - is the header a clone
1337 * @skb: buffer to check
1339 * Returns true if modifying the header part of the buffer requires
1340 * the data to be copied.
1342 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1349 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1350 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1351 return dataref
!= 1;
1354 static inline int skb_header_unclone(struct sk_buff
*skb
, gfp_t pri
)
1356 might_sleep_if(gfpflags_allow_blocking(pri
));
1358 if (skb_header_cloned(skb
))
1359 return pskb_expand_head(skb
, 0, 0, pri
);
1365 * skb_header_release - release reference to header
1366 * @skb: buffer to operate on
1368 * Drop a reference to the header part of the buffer. This is done
1369 * by acquiring a payload reference. You must not read from the header
1370 * part of skb->data after this.
1371 * Note : Check if you can use __skb_header_release() instead.
1373 static inline void skb_header_release(struct sk_buff
*skb
)
1377 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1381 * __skb_header_release - release reference to header
1382 * @skb: buffer to operate on
1384 * Variant of skb_header_release() assuming skb is private to caller.
1385 * We can avoid one atomic operation.
1387 static inline void __skb_header_release(struct sk_buff
*skb
)
1390 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1395 * skb_shared - is the buffer shared
1396 * @skb: buffer to check
1398 * Returns true if more than one person has a reference to this
1401 static inline int skb_shared(const struct sk_buff
*skb
)
1403 return refcount_read(&skb
->users
) != 1;
1407 * skb_share_check - check if buffer is shared and if so clone it
1408 * @skb: buffer to check
1409 * @pri: priority for memory allocation
1411 * If the buffer is shared the buffer is cloned and the old copy
1412 * drops a reference. A new clone with a single reference is returned.
1413 * If the buffer is not shared the original buffer is returned. When
1414 * being called from interrupt status or with spinlocks held pri must
1417 * NULL is returned on a memory allocation failure.
1419 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1421 might_sleep_if(gfpflags_allow_blocking(pri
));
1422 if (skb_shared(skb
)) {
1423 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1435 * Copy shared buffers into a new sk_buff. We effectively do COW on
1436 * packets to handle cases where we have a local reader and forward
1437 * and a couple of other messy ones. The normal one is tcpdumping
1438 * a packet thats being forwarded.
1442 * skb_unshare - make a copy of a shared buffer
1443 * @skb: buffer to check
1444 * @pri: priority for memory allocation
1446 * If the socket buffer is a clone then this function creates a new
1447 * copy of the data, drops a reference count on the old copy and returns
1448 * the new copy with the reference count at 1. If the buffer is not a clone
1449 * the original buffer is returned. When called with a spinlock held or
1450 * from interrupt state @pri must be %GFP_ATOMIC
1452 * %NULL is returned on a memory allocation failure.
1454 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1457 might_sleep_if(gfpflags_allow_blocking(pri
));
1458 if (skb_cloned(skb
)) {
1459 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1461 /* Free our shared copy */
1472 * skb_peek - peek at the head of an &sk_buff_head
1473 * @list_: list to peek at
1475 * Peek an &sk_buff. Unlike most other operations you _MUST_
1476 * be careful with this one. A peek leaves the buffer on the
1477 * list and someone else may run off with it. You must hold
1478 * the appropriate locks or have a private queue to do this.
1480 * Returns %NULL for an empty list or a pointer to the head element.
1481 * The reference count is not incremented and the reference is therefore
1482 * volatile. Use with caution.
1484 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1486 struct sk_buff
*skb
= list_
->next
;
1488 if (skb
== (struct sk_buff
*)list_
)
1494 * skb_peek_next - peek skb following the given one from a queue
1495 * @skb: skb to start from
1496 * @list_: list to peek at
1498 * Returns %NULL when the end of the list is met or a pointer to the
1499 * next element. The reference count is not incremented and the
1500 * reference is therefore volatile. Use with caution.
1502 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1503 const struct sk_buff_head
*list_
)
1505 struct sk_buff
*next
= skb
->next
;
1507 if (next
== (struct sk_buff
*)list_
)
1513 * skb_peek_tail - peek at the tail of an &sk_buff_head
1514 * @list_: list to peek at
1516 * Peek an &sk_buff. Unlike most other operations you _MUST_
1517 * be careful with this one. A peek leaves the buffer on the
1518 * list and someone else may run off with it. You must hold
1519 * the appropriate locks or have a private queue to do this.
1521 * Returns %NULL for an empty list or a pointer to the tail element.
1522 * The reference count is not incremented and the reference is therefore
1523 * volatile. Use with caution.
1525 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1527 struct sk_buff
*skb
= list_
->prev
;
1529 if (skb
== (struct sk_buff
*)list_
)
1536 * skb_queue_len - get queue length
1537 * @list_: list to measure
1539 * Return the length of an &sk_buff queue.
1541 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1547 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1548 * @list: queue to initialize
1550 * This initializes only the list and queue length aspects of
1551 * an sk_buff_head object. This allows to initialize the list
1552 * aspects of an sk_buff_head without reinitializing things like
1553 * the spinlock. It can also be used for on-stack sk_buff_head
1554 * objects where the spinlock is known to not be used.
1556 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1558 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1563 * This function creates a split out lock class for each invocation;
1564 * this is needed for now since a whole lot of users of the skb-queue
1565 * infrastructure in drivers have different locking usage (in hardirq)
1566 * than the networking core (in softirq only). In the long run either the
1567 * network layer or drivers should need annotation to consolidate the
1568 * main types of usage into 3 classes.
1570 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1572 spin_lock_init(&list
->lock
);
1573 __skb_queue_head_init(list
);
1576 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1577 struct lock_class_key
*class)
1579 skb_queue_head_init(list
);
1580 lockdep_set_class(&list
->lock
, class);
1584 * Insert an sk_buff on a list.
1586 * The "__skb_xxxx()" functions are the non-atomic ones that
1587 * can only be called with interrupts disabled.
1589 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1590 struct sk_buff_head
*list
);
1591 static inline void __skb_insert(struct sk_buff
*newsk
,
1592 struct sk_buff
*prev
, struct sk_buff
*next
,
1593 struct sk_buff_head
*list
)
1597 next
->prev
= prev
->next
= newsk
;
1601 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1602 struct sk_buff
*prev
,
1603 struct sk_buff
*next
)
1605 struct sk_buff
*first
= list
->next
;
1606 struct sk_buff
*last
= list
->prev
;
1616 * skb_queue_splice - join two skb lists, this is designed for stacks
1617 * @list: the new list to add
1618 * @head: the place to add it in the first list
1620 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1621 struct sk_buff_head
*head
)
1623 if (!skb_queue_empty(list
)) {
1624 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1625 head
->qlen
+= list
->qlen
;
1630 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1631 * @list: the new list to add
1632 * @head: the place to add it in the first list
1634 * The list at @list is reinitialised
1636 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1637 struct sk_buff_head
*head
)
1639 if (!skb_queue_empty(list
)) {
1640 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1641 head
->qlen
+= list
->qlen
;
1642 __skb_queue_head_init(list
);
1647 * skb_queue_splice_tail - join two skb lists, each list being a queue
1648 * @list: the new list to add
1649 * @head: the place to add it in the first list
1651 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1652 struct sk_buff_head
*head
)
1654 if (!skb_queue_empty(list
)) {
1655 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1656 head
->qlen
+= list
->qlen
;
1661 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1662 * @list: the new list to add
1663 * @head: the place to add it in the first list
1665 * Each of the lists is a queue.
1666 * The list at @list is reinitialised
1668 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1669 struct sk_buff_head
*head
)
1671 if (!skb_queue_empty(list
)) {
1672 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1673 head
->qlen
+= list
->qlen
;
1674 __skb_queue_head_init(list
);
1679 * __skb_queue_after - queue a buffer at the list head
1680 * @list: list to use
1681 * @prev: place after this buffer
1682 * @newsk: buffer to queue
1684 * Queue a buffer int the middle of a list. This function takes no locks
1685 * and you must therefore hold required locks before calling it.
1687 * A buffer cannot be placed on two lists at the same time.
1689 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1690 struct sk_buff
*prev
,
1691 struct sk_buff
*newsk
)
1693 __skb_insert(newsk
, prev
, prev
->next
, list
);
1696 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1697 struct sk_buff_head
*list
);
1699 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1700 struct sk_buff
*next
,
1701 struct sk_buff
*newsk
)
1703 __skb_insert(newsk
, next
->prev
, next
, list
);
1707 * __skb_queue_head - queue a buffer at the list head
1708 * @list: list to use
1709 * @newsk: buffer to queue
1711 * Queue a buffer at the start of a list. This function takes no locks
1712 * and you must therefore hold required locks before calling it.
1714 * A buffer cannot be placed on two lists at the same time.
1716 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1717 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1718 struct sk_buff
*newsk
)
1720 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1724 * __skb_queue_tail - queue a buffer at the list tail
1725 * @list: list to use
1726 * @newsk: buffer to queue
1728 * Queue a buffer at the end of a list. This function takes no locks
1729 * and you must therefore hold required locks before calling it.
1731 * A buffer cannot be placed on two lists at the same time.
1733 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1734 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1735 struct sk_buff
*newsk
)
1737 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1741 * remove sk_buff from list. _Must_ be called atomically, and with
1744 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1745 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1747 struct sk_buff
*next
, *prev
;
1752 skb
->next
= skb
->prev
= NULL
;
1758 * __skb_dequeue - remove from the head of the queue
1759 * @list: list to dequeue from
1761 * Remove the head of the list. This function does not take any locks
1762 * so must be used with appropriate locks held only. The head item is
1763 * returned or %NULL if the list is empty.
1765 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1766 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1768 struct sk_buff
*skb
= skb_peek(list
);
1770 __skb_unlink(skb
, list
);
1775 * __skb_dequeue_tail - remove from the tail of the queue
1776 * @list: list to dequeue from
1778 * Remove the tail of the list. This function does not take any locks
1779 * so must be used with appropriate locks held only. The tail item is
1780 * returned or %NULL if the list is empty.
1782 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1783 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1785 struct sk_buff
*skb
= skb_peek_tail(list
);
1787 __skb_unlink(skb
, list
);
1792 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1794 return skb
->data_len
;
1797 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1799 return skb
->len
- skb
->data_len
;
1802 static inline unsigned int skb_pagelen(const struct sk_buff
*skb
)
1804 unsigned int i
, len
= 0;
1806 for (i
= skb_shinfo(skb
)->nr_frags
- 1; (int)i
>= 0; i
--)
1807 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1808 return len
+ skb_headlen(skb
);
1812 * __skb_fill_page_desc - initialise a paged fragment in an skb
1813 * @skb: buffer containing fragment to be initialised
1814 * @i: paged fragment index to initialise
1815 * @page: the page to use for this fragment
1816 * @off: the offset to the data with @page
1817 * @size: the length of the data
1819 * Initialises the @i'th fragment of @skb to point to &size bytes at
1820 * offset @off within @page.
1822 * Does not take any additional reference on the fragment.
1824 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1825 struct page
*page
, int off
, int size
)
1827 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1830 * Propagate page pfmemalloc to the skb if we can. The problem is
1831 * that not all callers have unique ownership of the page but rely
1832 * on page_is_pfmemalloc doing the right thing(tm).
1834 frag
->page
.p
= page
;
1835 frag
->page_offset
= off
;
1836 skb_frag_size_set(frag
, size
);
1838 page
= compound_head(page
);
1839 if (page_is_pfmemalloc(page
))
1840 skb
->pfmemalloc
= true;
1844 * skb_fill_page_desc - initialise a paged fragment in an skb
1845 * @skb: buffer containing fragment to be initialised
1846 * @i: paged fragment index to initialise
1847 * @page: the page to use for this fragment
1848 * @off: the offset to the data with @page
1849 * @size: the length of the data
1851 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1852 * @skb to point to @size bytes at offset @off within @page. In
1853 * addition updates @skb such that @i is the last fragment.
1855 * Does not take any additional reference on the fragment.
1857 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1858 struct page
*page
, int off
, int size
)
1860 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1861 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1864 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1865 int size
, unsigned int truesize
);
1867 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1868 unsigned int truesize
);
1870 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1871 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1872 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1874 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1875 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1877 return skb
->head
+ skb
->tail
;
1880 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1882 skb
->tail
= skb
->data
- skb
->head
;
1885 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1887 skb_reset_tail_pointer(skb
);
1888 skb
->tail
+= offset
;
1891 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1892 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1897 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1899 skb
->tail
= skb
->data
;
1902 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1904 skb
->tail
= skb
->data
+ offset
;
1907 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1910 * Add data to an sk_buff
1912 void *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1913 void *skb_put(struct sk_buff
*skb
, unsigned int len
);
1914 static inline void *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1916 void *tmp
= skb_tail_pointer(skb
);
1917 SKB_LINEAR_ASSERT(skb
);
1923 static inline void *__skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
1925 void *tmp
= __skb_put(skb
, len
);
1927 memset(tmp
, 0, len
);
1931 static inline void *__skb_put_data(struct sk_buff
*skb
, const void *data
,
1934 void *tmp
= __skb_put(skb
, len
);
1936 memcpy(tmp
, data
, len
);
1940 static inline void __skb_put_u8(struct sk_buff
*skb
, u8 val
)
1942 *(u8
*)__skb_put(skb
, 1) = val
;
1945 static inline void *skb_put_zero(struct sk_buff
*skb
, unsigned int len
)
1947 void *tmp
= skb_put(skb
, len
);
1949 memset(tmp
, 0, len
);
1954 static inline void *skb_put_data(struct sk_buff
*skb
, const void *data
,
1957 void *tmp
= skb_put(skb
, len
);
1959 memcpy(tmp
, data
, len
);
1964 static inline void skb_put_u8(struct sk_buff
*skb
, u8 val
)
1966 *(u8
*)skb_put(skb
, 1) = val
;
1969 void *skb_push(struct sk_buff
*skb
, unsigned int len
);
1970 static inline void *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1977 void *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1978 static inline void *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1981 BUG_ON(skb
->len
< skb
->data_len
);
1982 return skb
->data
+= len
;
1985 static inline void *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1987 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1990 void *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1992 static inline void *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1994 if (len
> skb_headlen(skb
) &&
1995 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1998 return skb
->data
+= len
;
2001 static inline void *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
2003 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
2006 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
2008 if (likely(len
<= skb_headlen(skb
)))
2010 if (unlikely(len
> skb
->len
))
2012 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
2015 void skb_condense(struct sk_buff
*skb
);
2018 * skb_headroom - bytes at buffer head
2019 * @skb: buffer to check
2021 * Return the number of bytes of free space at the head of an &sk_buff.
2023 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
2025 return skb
->data
- skb
->head
;
2029 * skb_tailroom - bytes at buffer end
2030 * @skb: buffer to check
2032 * Return the number of bytes of free space at the tail of an sk_buff
2034 static inline int skb_tailroom(const struct sk_buff
*skb
)
2036 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
2040 * skb_availroom - bytes at buffer end
2041 * @skb: buffer to check
2043 * Return the number of bytes of free space at the tail of an sk_buff
2044 * allocated by sk_stream_alloc()
2046 static inline int skb_availroom(const struct sk_buff
*skb
)
2048 if (skb_is_nonlinear(skb
))
2051 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
2055 * skb_reserve - adjust headroom
2056 * @skb: buffer to alter
2057 * @len: bytes to move
2059 * Increase the headroom of an empty &sk_buff by reducing the tail
2060 * room. This is only allowed for an empty buffer.
2062 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
2069 * skb_tailroom_reserve - adjust reserved_tailroom
2070 * @skb: buffer to alter
2071 * @mtu: maximum amount of headlen permitted
2072 * @needed_tailroom: minimum amount of reserved_tailroom
2074 * Set reserved_tailroom so that headlen can be as large as possible but
2075 * not larger than mtu and tailroom cannot be smaller than
2077 * The required headroom should already have been reserved before using
2080 static inline void skb_tailroom_reserve(struct sk_buff
*skb
, unsigned int mtu
,
2081 unsigned int needed_tailroom
)
2083 SKB_LINEAR_ASSERT(skb
);
2084 if (mtu
< skb_tailroom(skb
) - needed_tailroom
)
2085 /* use at most mtu */
2086 skb
->reserved_tailroom
= skb_tailroom(skb
) - mtu
;
2088 /* use up to all available space */
2089 skb
->reserved_tailroom
= needed_tailroom
;
2092 #define ENCAP_TYPE_ETHER 0
2093 #define ENCAP_TYPE_IPPROTO 1
2095 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
2098 skb
->inner_protocol
= protocol
;
2099 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
2102 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
2105 skb
->inner_ipproto
= ipproto
;
2106 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
2109 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
2111 skb
->inner_mac_header
= skb
->mac_header
;
2112 skb
->inner_network_header
= skb
->network_header
;
2113 skb
->inner_transport_header
= skb
->transport_header
;
2116 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
2118 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
2121 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2124 return skb
->head
+ skb
->inner_transport_header
;
2127 static inline int skb_inner_transport_offset(const struct sk_buff
*skb
)
2129 return skb_inner_transport_header(skb
) - skb
->data
;
2132 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
2134 skb
->inner_transport_header
= skb
->data
- skb
->head
;
2137 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
2140 skb_reset_inner_transport_header(skb
);
2141 skb
->inner_transport_header
+= offset
;
2144 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
2146 return skb
->head
+ skb
->inner_network_header
;
2149 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
2151 skb
->inner_network_header
= skb
->data
- skb
->head
;
2154 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
2157 skb_reset_inner_network_header(skb
);
2158 skb
->inner_network_header
+= offset
;
2161 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
2163 return skb
->head
+ skb
->inner_mac_header
;
2166 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
2168 skb
->inner_mac_header
= skb
->data
- skb
->head
;
2171 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
2174 skb_reset_inner_mac_header(skb
);
2175 skb
->inner_mac_header
+= offset
;
2177 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
2179 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
2182 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
2184 return skb
->head
+ skb
->transport_header
;
2187 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
2189 skb
->transport_header
= skb
->data
- skb
->head
;
2192 static inline void skb_set_transport_header(struct sk_buff
*skb
,
2195 skb_reset_transport_header(skb
);
2196 skb
->transport_header
+= offset
;
2199 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
2201 return skb
->head
+ skb
->network_header
;
2204 static inline void skb_reset_network_header(struct sk_buff
*skb
)
2206 skb
->network_header
= skb
->data
- skb
->head
;
2209 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
2211 skb_reset_network_header(skb
);
2212 skb
->network_header
+= offset
;
2215 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
2217 return skb
->head
+ skb
->mac_header
;
2220 static inline int skb_mac_offset(const struct sk_buff
*skb
)
2222 return skb_mac_header(skb
) - skb
->data
;
2225 static inline u32
skb_mac_header_len(const struct sk_buff
*skb
)
2227 return skb
->network_header
- skb
->mac_header
;
2230 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
2232 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
2235 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
2237 skb
->mac_header
= skb
->data
- skb
->head
;
2240 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
2242 skb_reset_mac_header(skb
);
2243 skb
->mac_header
+= offset
;
2246 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
2248 skb
->mac_header
= skb
->network_header
;
2251 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
2252 const int offset_hint
)
2254 struct flow_keys keys
;
2256 if (skb_transport_header_was_set(skb
))
2258 else if (skb_flow_dissect_flow_keys(skb
, &keys
, 0))
2259 skb_set_transport_header(skb
, keys
.control
.thoff
);
2261 skb_set_transport_header(skb
, offset_hint
);
2264 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
2266 if (skb_mac_header_was_set(skb
)) {
2267 const unsigned char *old_mac
= skb_mac_header(skb
);
2269 skb_set_mac_header(skb
, -skb
->mac_len
);
2270 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
2274 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
2276 return skb
->csum_start
- skb_headroom(skb
);
2279 static inline unsigned char *skb_checksum_start(const struct sk_buff
*skb
)
2281 return skb
->head
+ skb
->csum_start
;
2284 static inline int skb_transport_offset(const struct sk_buff
*skb
)
2286 return skb_transport_header(skb
) - skb
->data
;
2289 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
2291 return skb
->transport_header
- skb
->network_header
;
2294 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
2296 return skb
->inner_transport_header
- skb
->inner_network_header
;
2299 static inline int skb_network_offset(const struct sk_buff
*skb
)
2301 return skb_network_header(skb
) - skb
->data
;
2304 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
2306 return skb_inner_network_header(skb
) - skb
->data
;
2309 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
2311 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
2315 * CPUs often take a performance hit when accessing unaligned memory
2316 * locations. The actual performance hit varies, it can be small if the
2317 * hardware handles it or large if we have to take an exception and fix it
2320 * Since an ethernet header is 14 bytes network drivers often end up with
2321 * the IP header at an unaligned offset. The IP header can be aligned by
2322 * shifting the start of the packet by 2 bytes. Drivers should do this
2325 * skb_reserve(skb, NET_IP_ALIGN);
2327 * The downside to this alignment of the IP header is that the DMA is now
2328 * unaligned. On some architectures the cost of an unaligned DMA is high
2329 * and this cost outweighs the gains made by aligning the IP header.
2331 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2334 #ifndef NET_IP_ALIGN
2335 #define NET_IP_ALIGN 2
2339 * The networking layer reserves some headroom in skb data (via
2340 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2341 * the header has to grow. In the default case, if the header has to grow
2342 * 32 bytes or less we avoid the reallocation.
2344 * Unfortunately this headroom changes the DMA alignment of the resulting
2345 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2346 * on some architectures. An architecture can override this value,
2347 * perhaps setting it to a cacheline in size (since that will maintain
2348 * cacheline alignment of the DMA). It must be a power of 2.
2350 * Various parts of the networking layer expect at least 32 bytes of
2351 * headroom, you should not reduce this.
2353 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2354 * to reduce average number of cache lines per packet.
2355 * get_rps_cpus() for example only access one 64 bytes aligned block :
2356 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2359 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2362 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2364 static inline void __skb_set_length(struct sk_buff
*skb
, unsigned int len
)
2366 if (unlikely(skb_is_nonlinear(skb
))) {
2371 skb_set_tail_pointer(skb
, len
);
2374 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2376 __skb_set_length(skb
, len
);
2379 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2381 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2384 return ___pskb_trim(skb
, len
);
2385 __skb_trim(skb
, len
);
2389 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2391 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2395 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2396 * @skb: buffer to alter
2399 * This is identical to pskb_trim except that the caller knows that
2400 * the skb is not cloned so we should never get an error due to out-
2403 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2405 int err
= pskb_trim(skb
, len
);
2409 static inline int __skb_grow(struct sk_buff
*skb
, unsigned int len
)
2411 unsigned int diff
= len
- skb
->len
;
2413 if (skb_tailroom(skb
) < diff
) {
2414 int ret
= pskb_expand_head(skb
, 0, diff
- skb_tailroom(skb
),
2419 __skb_set_length(skb
, len
);
2424 * skb_orphan - orphan a buffer
2425 * @skb: buffer to orphan
2427 * If a buffer currently has an owner then we call the owner's
2428 * destructor function and make the @skb unowned. The buffer continues
2429 * to exist but is no longer charged to its former owner.
2431 static inline void skb_orphan(struct sk_buff
*skb
)
2433 if (skb
->destructor
) {
2434 skb
->destructor(skb
);
2435 skb
->destructor
= NULL
;
2443 * skb_orphan_frags - orphan the frags contained in a buffer
2444 * @skb: buffer to orphan frags from
2445 * @gfp_mask: allocation mask for replacement pages
2447 * For each frag in the SKB which needs a destructor (i.e. has an
2448 * owner) create a copy of that frag and release the original
2449 * page by calling the destructor.
2451 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2453 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
2455 return skb_copy_ubufs(skb
, gfp_mask
);
2459 * __skb_queue_purge - empty a list
2460 * @list: list to empty
2462 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2463 * the list and one reference dropped. This function does not take the
2464 * list lock and the caller must hold the relevant locks to use it.
2466 void skb_queue_purge(struct sk_buff_head
*list
);
2467 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2469 struct sk_buff
*skb
;
2470 while ((skb
= __skb_dequeue(list
)) != NULL
)
2474 void skb_rbtree_purge(struct rb_root
*root
);
2476 void *netdev_alloc_frag(unsigned int fragsz
);
2478 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2482 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2483 * @dev: network device to receive on
2484 * @length: length to allocate
2486 * Allocate a new &sk_buff and assign it a usage count of one. The
2487 * buffer has unspecified headroom built in. Users should allocate
2488 * the headroom they think they need without accounting for the
2489 * built in space. The built in space is used for optimisations.
2491 * %NULL is returned if there is no free memory. Although this function
2492 * allocates memory it can be called from an interrupt.
2494 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2495 unsigned int length
)
2497 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2500 /* legacy helper around __netdev_alloc_skb() */
2501 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2504 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2507 /* legacy helper around netdev_alloc_skb() */
2508 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2510 return netdev_alloc_skb(NULL
, length
);
2514 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2515 unsigned int length
, gfp_t gfp
)
2517 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2519 if (NET_IP_ALIGN
&& skb
)
2520 skb_reserve(skb
, NET_IP_ALIGN
);
2524 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2525 unsigned int length
)
2527 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2530 static inline void skb_free_frag(void *addr
)
2532 page_frag_free(addr
);
2535 void *napi_alloc_frag(unsigned int fragsz
);
2536 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2537 unsigned int length
, gfp_t gfp_mask
);
2538 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2539 unsigned int length
)
2541 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2543 void napi_consume_skb(struct sk_buff
*skb
, int budget
);
2545 void __kfree_skb_flush(void);
2546 void __kfree_skb_defer(struct sk_buff
*skb
);
2549 * __dev_alloc_pages - allocate page for network Rx
2550 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2551 * @order: size of the allocation
2553 * Allocate a new page.
2555 * %NULL is returned if there is no free memory.
2557 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2560 /* This piece of code contains several assumptions.
2561 * 1. This is for device Rx, therefor a cold page is preferred.
2562 * 2. The expectation is the user wants a compound page.
2563 * 3. If requesting a order 0 page it will not be compound
2564 * due to the check to see if order has a value in prep_new_page
2565 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2566 * code in gfp_to_alloc_flags that should be enforcing this.
2568 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2570 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2573 static inline struct page
*dev_alloc_pages(unsigned int order
)
2575 return __dev_alloc_pages(GFP_ATOMIC
| __GFP_NOWARN
, order
);
2579 * __dev_alloc_page - allocate a page for network Rx
2580 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2582 * Allocate a new page.
2584 * %NULL is returned if there is no free memory.
2586 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2588 return __dev_alloc_pages(gfp_mask
, 0);
2591 static inline struct page
*dev_alloc_page(void)
2593 return dev_alloc_pages(0);
2597 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2598 * @page: The page that was allocated from skb_alloc_page
2599 * @skb: The skb that may need pfmemalloc set
2601 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2602 struct sk_buff
*skb
)
2604 if (page_is_pfmemalloc(page
))
2605 skb
->pfmemalloc
= true;
2609 * skb_frag_page - retrieve the page referred to by a paged fragment
2610 * @frag: the paged fragment
2612 * Returns the &struct page associated with @frag.
2614 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2616 return frag
->page
.p
;
2620 * __skb_frag_ref - take an addition reference on a paged fragment.
2621 * @frag: the paged fragment
2623 * Takes an additional reference on the paged fragment @frag.
2625 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2627 get_page(skb_frag_page(frag
));
2631 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2633 * @f: the fragment offset.
2635 * Takes an additional reference on the @f'th paged fragment of @skb.
2637 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2639 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2643 * __skb_frag_unref - release a reference on a paged fragment.
2644 * @frag: the paged fragment
2646 * Releases a reference on the paged fragment @frag.
2648 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2650 put_page(skb_frag_page(frag
));
2654 * skb_frag_unref - release a reference on a paged fragment of an skb.
2656 * @f: the fragment offset
2658 * Releases a reference on the @f'th paged fragment of @skb.
2660 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2662 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2666 * skb_frag_address - gets the address of the data contained in a paged fragment
2667 * @frag: the paged fragment buffer
2669 * Returns the address of the data within @frag. The page must already
2672 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2674 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2678 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2679 * @frag: the paged fragment buffer
2681 * Returns the address of the data within @frag. Checks that the page
2682 * is mapped and returns %NULL otherwise.
2684 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2686 void *ptr
= page_address(skb_frag_page(frag
));
2690 return ptr
+ frag
->page_offset
;
2694 * __skb_frag_set_page - sets the page contained in a paged fragment
2695 * @frag: the paged fragment
2696 * @page: the page to set
2698 * Sets the fragment @frag to contain @page.
2700 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2702 frag
->page
.p
= page
;
2706 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2708 * @f: the fragment offset
2709 * @page: the page to set
2711 * Sets the @f'th fragment of @skb to contain @page.
2713 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2716 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2719 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2722 * skb_frag_dma_map - maps a paged fragment via the DMA API
2723 * @dev: the device to map the fragment to
2724 * @frag: the paged fragment to map
2725 * @offset: the offset within the fragment (starting at the
2726 * fragment's own offset)
2727 * @size: the number of bytes to map
2728 * @dir: the direction of the mapping (``PCI_DMA_*``)
2730 * Maps the page associated with @frag to @device.
2732 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2733 const skb_frag_t
*frag
,
2734 size_t offset
, size_t size
,
2735 enum dma_data_direction dir
)
2737 return dma_map_page(dev
, skb_frag_page(frag
),
2738 frag
->page_offset
+ offset
, size
, dir
);
2741 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2744 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2748 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2751 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2756 * skb_clone_writable - is the header of a clone writable
2757 * @skb: buffer to check
2758 * @len: length up to which to write
2760 * Returns true if modifying the header part of the cloned buffer
2761 * does not requires the data to be copied.
2763 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2765 return !skb_header_cloned(skb
) &&
2766 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2769 static inline int skb_try_make_writable(struct sk_buff
*skb
,
2770 unsigned int write_len
)
2772 return skb_cloned(skb
) && !skb_clone_writable(skb
, write_len
) &&
2773 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
2776 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2781 if (headroom
> skb_headroom(skb
))
2782 delta
= headroom
- skb_headroom(skb
);
2784 if (delta
|| cloned
)
2785 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2791 * skb_cow - copy header of skb when it is required
2792 * @skb: buffer to cow
2793 * @headroom: needed headroom
2795 * If the skb passed lacks sufficient headroom or its data part
2796 * is shared, data is reallocated. If reallocation fails, an error
2797 * is returned and original skb is not changed.
2799 * The result is skb with writable area skb->head...skb->tail
2800 * and at least @headroom of space at head.
2802 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2804 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2808 * skb_cow_head - skb_cow but only making the head writable
2809 * @skb: buffer to cow
2810 * @headroom: needed headroom
2812 * This function is identical to skb_cow except that we replace the
2813 * skb_cloned check by skb_header_cloned. It should be used when
2814 * you only need to push on some header and do not need to modify
2817 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2819 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2823 * skb_padto - pad an skbuff up to a minimal size
2824 * @skb: buffer to pad
2825 * @len: minimal length
2827 * Pads up a buffer to ensure the trailing bytes exist and are
2828 * blanked. If the buffer already contains sufficient data it
2829 * is untouched. Otherwise it is extended. Returns zero on
2830 * success. The skb is freed on error.
2832 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2834 unsigned int size
= skb
->len
;
2835 if (likely(size
>= len
))
2837 return skb_pad(skb
, len
- size
);
2841 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2842 * @skb: buffer to pad
2843 * @len: minimal length
2844 * @free_on_error: free buffer on error
2846 * Pads up a buffer to ensure the trailing bytes exist and are
2847 * blanked. If the buffer already contains sufficient data it
2848 * is untouched. Otherwise it is extended. Returns zero on
2849 * success. The skb is freed on error if @free_on_error is true.
2851 static inline int __skb_put_padto(struct sk_buff
*skb
, unsigned int len
,
2854 unsigned int size
= skb
->len
;
2856 if (unlikely(size
< len
)) {
2858 if (__skb_pad(skb
, len
, free_on_error
))
2860 __skb_put(skb
, len
);
2866 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2867 * @skb: buffer to pad
2868 * @len: minimal length
2870 * Pads up a buffer to ensure the trailing bytes exist and are
2871 * blanked. If the buffer already contains sufficient data it
2872 * is untouched. Otherwise it is extended. Returns zero on
2873 * success. The skb is freed on error.
2875 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2877 return __skb_put_padto(skb
, len
, true);
2880 static inline int skb_add_data(struct sk_buff
*skb
,
2881 struct iov_iter
*from
, int copy
)
2883 const int off
= skb
->len
;
2885 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2887 if (csum_and_copy_from_iter_full(skb_put(skb
, copy
), copy
,
2889 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2892 } else if (copy_from_iter_full(skb_put(skb
, copy
), copy
, from
))
2895 __skb_trim(skb
, off
);
2899 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2900 const struct page
*page
, int off
)
2903 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2905 return page
== skb_frag_page(frag
) &&
2906 off
== frag
->page_offset
+ skb_frag_size(frag
);
2911 static inline int __skb_linearize(struct sk_buff
*skb
)
2913 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2917 * skb_linearize - convert paged skb to linear one
2918 * @skb: buffer to linarize
2920 * If there is no free memory -ENOMEM is returned, otherwise zero
2921 * is returned and the old skb data released.
2923 static inline int skb_linearize(struct sk_buff
*skb
)
2925 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2929 * skb_has_shared_frag - can any frag be overwritten
2930 * @skb: buffer to test
2932 * Return true if the skb has at least one frag that might be modified
2933 * by an external entity (as in vmsplice()/sendfile())
2935 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2937 return skb_is_nonlinear(skb
) &&
2938 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2942 * skb_linearize_cow - make sure skb is linear and writable
2943 * @skb: buffer to process
2945 * If there is no free memory -ENOMEM is returned, otherwise zero
2946 * is returned and the old skb data released.
2948 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2950 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2951 __skb_linearize(skb
) : 0;
2954 static __always_inline
void
2955 __skb_postpull_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
2958 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2959 skb
->csum
= csum_block_sub(skb
->csum
,
2960 csum_partial(start
, len
, 0), off
);
2961 else if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
2962 skb_checksum_start_offset(skb
) < 0)
2963 skb
->ip_summed
= CHECKSUM_NONE
;
2967 * skb_postpull_rcsum - update checksum for received skb after pull
2968 * @skb: buffer to update
2969 * @start: start of data before pull
2970 * @len: length of data pulled
2972 * After doing a pull on a received packet, you need to call this to
2973 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2974 * CHECKSUM_NONE so that it can be recomputed from scratch.
2976 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2977 const void *start
, unsigned int len
)
2979 __skb_postpull_rcsum(skb
, start
, len
, 0);
2982 static __always_inline
void
2983 __skb_postpush_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
2986 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2987 skb
->csum
= csum_block_add(skb
->csum
,
2988 csum_partial(start
, len
, 0), off
);
2992 * skb_postpush_rcsum - update checksum for received skb after push
2993 * @skb: buffer to update
2994 * @start: start of data after push
2995 * @len: length of data pushed
2997 * After doing a push on a received packet, you need to call this to
2998 * update the CHECKSUM_COMPLETE checksum.
3000 static inline void skb_postpush_rcsum(struct sk_buff
*skb
,
3001 const void *start
, unsigned int len
)
3003 __skb_postpush_rcsum(skb
, start
, len
, 0);
3006 void *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
3009 * skb_push_rcsum - push skb and update receive checksum
3010 * @skb: buffer to update
3011 * @len: length of data pulled
3013 * This function performs an skb_push on the packet and updates
3014 * the CHECKSUM_COMPLETE checksum. It should be used on
3015 * receive path processing instead of skb_push unless you know
3016 * that the checksum difference is zero (e.g., a valid IP header)
3017 * or you are setting ip_summed to CHECKSUM_NONE.
3019 static inline void *skb_push_rcsum(struct sk_buff
*skb
, unsigned int len
)
3022 skb_postpush_rcsum(skb
, skb
->data
, len
);
3027 * pskb_trim_rcsum - trim received skb and update checksum
3028 * @skb: buffer to trim
3031 * This is exactly the same as pskb_trim except that it ensures the
3032 * checksum of received packets are still valid after the operation.
3035 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3037 if (likely(len
>= skb
->len
))
3039 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3040 skb
->ip_summed
= CHECKSUM_NONE
;
3041 return __pskb_trim(skb
, len
);
3044 static inline int __skb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
3046 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3047 skb
->ip_summed
= CHECKSUM_NONE
;
3048 __skb_trim(skb
, len
);
3052 static inline int __skb_grow_rcsum(struct sk_buff
*skb
, unsigned int len
)
3054 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3055 skb
->ip_summed
= CHECKSUM_NONE
;
3056 return __skb_grow(skb
, len
);
3059 #define skb_queue_walk(queue, skb) \
3060 for (skb = (queue)->next; \
3061 skb != (struct sk_buff *)(queue); \
3064 #define skb_queue_walk_safe(queue, skb, tmp) \
3065 for (skb = (queue)->next, tmp = skb->next; \
3066 skb != (struct sk_buff *)(queue); \
3067 skb = tmp, tmp = skb->next)
3069 #define skb_queue_walk_from(queue, skb) \
3070 for (; skb != (struct sk_buff *)(queue); \
3073 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3074 for (tmp = skb->next; \
3075 skb != (struct sk_buff *)(queue); \
3076 skb = tmp, tmp = skb->next)
3078 #define skb_queue_reverse_walk(queue, skb) \
3079 for (skb = (queue)->prev; \
3080 skb != (struct sk_buff *)(queue); \
3083 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3084 for (skb = (queue)->prev, tmp = skb->prev; \
3085 skb != (struct sk_buff *)(queue); \
3086 skb = tmp, tmp = skb->prev)
3088 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3089 for (tmp = skb->prev; \
3090 skb != (struct sk_buff *)(queue); \
3091 skb = tmp, tmp = skb->prev)
3093 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
3095 return skb_shinfo(skb
)->frag_list
!= NULL
;
3098 static inline void skb_frag_list_init(struct sk_buff
*skb
)
3100 skb_shinfo(skb
)->frag_list
= NULL
;
3103 #define skb_walk_frags(skb, iter) \
3104 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3107 int __skb_wait_for_more_packets(struct sock
*sk
, int *err
, long *timeo_p
,
3108 const struct sk_buff
*skb
);
3109 struct sk_buff
*__skb_try_recv_from_queue(struct sock
*sk
,
3110 struct sk_buff_head
*queue
,
3112 void (*destructor
)(struct sock
*sk
,
3113 struct sk_buff
*skb
),
3114 int *peeked
, int *off
, int *err
,
3115 struct sk_buff
**last
);
3116 struct sk_buff
*__skb_try_recv_datagram(struct sock
*sk
, unsigned flags
,
3117 void (*destructor
)(struct sock
*sk
,
3118 struct sk_buff
*skb
),
3119 int *peeked
, int *off
, int *err
,
3120 struct sk_buff
**last
);
3121 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
3122 void (*destructor
)(struct sock
*sk
,
3123 struct sk_buff
*skb
),
3124 int *peeked
, int *off
, int *err
);
3125 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
3127 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
3128 struct poll_table_struct
*wait
);
3129 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
3130 struct iov_iter
*to
, int size
);
3131 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
3132 struct msghdr
*msg
, int size
)
3134 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
3136 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
3137 struct msghdr
*msg
);
3138 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
3139 struct iov_iter
*from
, int len
);
3140 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
3141 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
3142 void __skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
, int len
);
3143 static inline void skb_free_datagram_locked(struct sock
*sk
,
3144 struct sk_buff
*skb
)
3146 __skb_free_datagram_locked(sk
, skb
, 0);
3148 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
3149 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
3150 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
3151 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
3152 int len
, __wsum csum
);
3153 int skb_splice_bits(struct sk_buff
*skb
, struct sock
*sk
, unsigned int offset
,
3154 struct pipe_inode_info
*pipe
, unsigned int len
,
3155 unsigned int flags
);
3156 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
3157 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
3158 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
3160 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
3161 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
3162 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
3163 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
3164 bool skb_gso_validate_mtu(const struct sk_buff
*skb
, unsigned int mtu
);
3165 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
3166 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
3167 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
3168 int __skb_vlan_pop(struct sk_buff
*skb
, u16
*vlan_tci
);
3169 int skb_vlan_pop(struct sk_buff
*skb
);
3170 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
3171 struct sk_buff
*pskb_extract(struct sk_buff
*skb
, int off
, int to_copy
,
3174 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
3176 return copy_from_iter_full(data
, len
, &msg
->msg_iter
) ? 0 : -EFAULT
;
3179 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
3181 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3184 struct skb_checksum_ops
{
3185 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
3186 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
3189 extern const struct skb_checksum_ops
*crc32c_csum_stub __read_mostly
;
3191 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3192 __wsum csum
, const struct skb_checksum_ops
*ops
);
3193 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3196 static inline void * __must_check
3197 __skb_header_pointer(const struct sk_buff
*skb
, int offset
,
3198 int len
, void *data
, int hlen
, void *buffer
)
3200 if (hlen
- offset
>= len
)
3201 return data
+ offset
;
3204 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
3210 static inline void * __must_check
3211 skb_header_pointer(const struct sk_buff
*skb
, int offset
, int len
, void *buffer
)
3213 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
3214 skb_headlen(skb
), buffer
);
3218 * skb_needs_linearize - check if we need to linearize a given skb
3219 * depending on the given device features.
3220 * @skb: socket buffer to check
3221 * @features: net device features
3223 * Returns true if either:
3224 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3225 * 2. skb is fragmented and the device does not support SG.
3227 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
3228 netdev_features_t features
)
3230 return skb_is_nonlinear(skb
) &&
3231 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
3232 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
3235 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
3237 const unsigned int len
)
3239 memcpy(to
, skb
->data
, len
);
3242 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
3243 const int offset
, void *to
,
3244 const unsigned int len
)
3246 memcpy(to
, skb
->data
+ offset
, len
);
3249 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
3251 const unsigned int len
)
3253 memcpy(skb
->data
, from
, len
);
3256 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
3259 const unsigned int len
)
3261 memcpy(skb
->data
+ offset
, from
, len
);
3264 void skb_init(void);
3266 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
3272 * skb_get_timestamp - get timestamp from a skb
3273 * @skb: skb to get stamp from
3274 * @stamp: pointer to struct timeval to store stamp in
3276 * Timestamps are stored in the skb as offsets to a base timestamp.
3277 * This function converts the offset back to a struct timeval and stores
3280 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
3281 struct timeval
*stamp
)
3283 *stamp
= ktime_to_timeval(skb
->tstamp
);
3286 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
3287 struct timespec
*stamp
)
3289 *stamp
= ktime_to_timespec(skb
->tstamp
);
3292 static inline void __net_timestamp(struct sk_buff
*skb
)
3294 skb
->tstamp
= ktime_get_real();
3297 static inline ktime_t
net_timedelta(ktime_t t
)
3299 return ktime_sub(ktime_get_real(), t
);
3302 static inline ktime_t
net_invalid_timestamp(void)
3307 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
3309 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3311 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
3312 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
3314 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3316 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
3320 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
3325 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3328 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3330 * PHY drivers may accept clones of transmitted packets for
3331 * timestamping via their phy_driver.txtstamp method. These drivers
3332 * must call this function to return the skb back to the stack with a
3335 * @skb: clone of the the original outgoing packet
3336 * @hwtstamps: hardware time stamps
3339 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
3340 struct skb_shared_hwtstamps
*hwtstamps
);
3342 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
3343 struct skb_shared_hwtstamps
*hwtstamps
,
3344 struct sock
*sk
, int tstype
);
3347 * skb_tstamp_tx - queue clone of skb with send time stamps
3348 * @orig_skb: the original outgoing packet
3349 * @hwtstamps: hardware time stamps, may be NULL if not available
3351 * If the skb has a socket associated, then this function clones the
3352 * skb (thus sharing the actual data and optional structures), stores
3353 * the optional hardware time stamping information (if non NULL) or
3354 * generates a software time stamp (otherwise), then queues the clone
3355 * to the error queue of the socket. Errors are silently ignored.
3357 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
3358 struct skb_shared_hwtstamps
*hwtstamps
);
3361 * skb_tx_timestamp() - Driver hook for transmit timestamping
3363 * Ethernet MAC Drivers should call this function in their hard_xmit()
3364 * function immediately before giving the sk_buff to the MAC hardware.
3366 * Specifically, one should make absolutely sure that this function is
3367 * called before TX completion of this packet can trigger. Otherwise
3368 * the packet could potentially already be freed.
3370 * @skb: A socket buffer.
3372 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
3374 skb_clone_tx_timestamp(skb
);
3375 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
)
3376 skb_tstamp_tx(skb
, NULL
);
3380 * skb_complete_wifi_ack - deliver skb with wifi status
3382 * @skb: the original outgoing packet
3383 * @acked: ack status
3386 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
3388 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
3389 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
3391 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
3393 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
3395 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3396 skb_checksum_start_offset(skb
) >= 0));
3400 * skb_checksum_complete - Calculate checksum of an entire packet
3401 * @skb: packet to process
3403 * This function calculates the checksum over the entire packet plus
3404 * the value of skb->csum. The latter can be used to supply the
3405 * checksum of a pseudo header as used by TCP/UDP. It returns the
3408 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3409 * this function can be used to verify that checksum on received
3410 * packets. In that case the function should return zero if the
3411 * checksum is correct. In particular, this function will return zero
3412 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3413 * hardware has already verified the correctness of the checksum.
3415 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
3417 return skb_csum_unnecessary(skb
) ?
3418 0 : __skb_checksum_complete(skb
);
3421 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
3423 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3424 if (skb
->csum_level
== 0)
3425 skb
->ip_summed
= CHECKSUM_NONE
;
3431 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
3433 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3434 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
3436 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
3437 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
3438 skb
->csum_level
= 0;
3442 /* Check if we need to perform checksum complete validation.
3444 * Returns true if checksum complete is needed, false otherwise
3445 * (either checksum is unnecessary or zero checksum is allowed).
3447 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3451 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3452 skb
->csum_valid
= 1;
3453 __skb_decr_checksum_unnecessary(skb
);
3460 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3463 #define CHECKSUM_BREAK 76
3465 /* Unset checksum-complete
3467 * Unset checksum complete can be done when packet is being modified
3468 * (uncompressed for instance) and checksum-complete value is
3471 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3473 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3474 skb
->ip_summed
= CHECKSUM_NONE
;
3477 /* Validate (init) checksum based on checksum complete.
3480 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3481 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3482 * checksum is stored in skb->csum for use in __skb_checksum_complete
3483 * non-zero: value of invalid checksum
3486 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3490 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3491 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3492 skb
->csum_valid
= 1;
3499 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3502 csum
= __skb_checksum_complete(skb
);
3503 skb
->csum_valid
= !csum
;
3510 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3515 /* Perform checksum validate (init). Note that this is a macro since we only
3516 * want to calculate the pseudo header which is an input function if necessary.
3517 * First we try to validate without any computation (checksum unnecessary) and
3518 * then calculate based on checksum complete calling the function to compute
3522 * 0: checksum is validated or try to in skb_checksum_complete
3523 * non-zero: value of invalid checksum
3525 #define __skb_checksum_validate(skb, proto, complete, \
3526 zero_okay, check, compute_pseudo) \
3528 __sum16 __ret = 0; \
3529 skb->csum_valid = 0; \
3530 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3531 __ret = __skb_checksum_validate_complete(skb, \
3532 complete, compute_pseudo(skb, proto)); \
3536 #define skb_checksum_init(skb, proto, compute_pseudo) \
3537 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3539 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3540 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3542 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3543 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3545 #define skb_checksum_validate_zero_check(skb, proto, check, \
3547 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3549 #define skb_checksum_simple_validate(skb) \
3550 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3552 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3554 return (skb
->ip_summed
== CHECKSUM_NONE
&& skb
->csum_valid
);
3557 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3558 __sum16 check
, __wsum pseudo
)
3560 skb
->csum
= ~pseudo
;
3561 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3564 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3566 if (__skb_checksum_convert_check(skb)) \
3567 __skb_checksum_convert(skb, check, \
3568 compute_pseudo(skb, proto)); \
3571 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3572 u16 start
, u16 offset
)
3574 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3575 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3576 skb
->csum_offset
= offset
- start
;
3579 /* Update skbuf and packet to reflect the remote checksum offload operation.
3580 * When called, ptr indicates the starting point for skb->csum when
3581 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3582 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3584 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3585 int start
, int offset
, bool nopartial
)
3590 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3594 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3595 __skb_checksum_complete(skb
);
3596 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3599 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3601 /* Adjust skb->csum since we changed the packet */
3602 skb
->csum
= csum_add(skb
->csum
, delta
);
3605 static inline struct nf_conntrack
*skb_nfct(const struct sk_buff
*skb
)
3607 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3608 return (void *)(skb
->_nfct
& SKB_NFCT_PTRMASK
);
3614 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3615 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3616 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3618 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3619 nf_conntrack_destroy(nfct
);
3621 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3624 atomic_inc(&nfct
->use
);
3627 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3628 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3630 if (nf_bridge
&& refcount_dec_and_test(&nf_bridge
->use
))
3633 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3636 refcount_inc(&nf_bridge
->use
);
3638 #endif /* CONFIG_BRIDGE_NETFILTER */
3639 static inline void nf_reset(struct sk_buff
*skb
)
3641 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3642 nf_conntrack_put(skb_nfct(skb
));
3645 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3646 nf_bridge_put(skb
->nf_bridge
);
3647 skb
->nf_bridge
= NULL
;
3651 static inline void nf_reset_trace(struct sk_buff
*skb
)
3653 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3658 /* Note: This doesn't put any conntrack and bridge info in dst. */
3659 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3662 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3663 dst
->_nfct
= src
->_nfct
;
3664 nf_conntrack_get(skb_nfct(src
));
3666 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3667 dst
->nf_bridge
= src
->nf_bridge
;
3668 nf_bridge_get(src
->nf_bridge
);
3670 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3672 dst
->nf_trace
= src
->nf_trace
;
3676 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3678 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3679 nf_conntrack_put(skb_nfct(dst
));
3681 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3682 nf_bridge_put(dst
->nf_bridge
);
3684 __nf_copy(dst
, src
, true);
3687 #ifdef CONFIG_NETWORK_SECMARK
3688 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3690 to
->secmark
= from
->secmark
;
3693 static inline void skb_init_secmark(struct sk_buff
*skb
)
3698 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3701 static inline void skb_init_secmark(struct sk_buff
*skb
)
3705 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3707 return !skb
->destructor
&&
3708 #if IS_ENABLED(CONFIG_XFRM)
3712 !skb
->_skb_refdst
&&
3713 !skb_has_frag_list(skb
);
3716 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3718 skb
->queue_mapping
= queue_mapping
;
3721 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3723 return skb
->queue_mapping
;
3726 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3728 to
->queue_mapping
= from
->queue_mapping
;
3731 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3733 skb
->queue_mapping
= rx_queue
+ 1;
3736 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3738 return skb
->queue_mapping
- 1;
3741 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3743 return skb
->queue_mapping
!= 0;
3746 static inline void skb_set_dst_pending_confirm(struct sk_buff
*skb
, u32 val
)
3748 skb
->dst_pending_confirm
= val
;
3751 static inline bool skb_get_dst_pending_confirm(const struct sk_buff
*skb
)
3753 return skb
->dst_pending_confirm
!= 0;
3756 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3765 /* Keeps track of mac header offset relative to skb->head.
3766 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3767 * For non-tunnel skb it points to skb_mac_header() and for
3768 * tunnel skb it points to outer mac header.
3769 * Keeps track of level of encapsulation of network headers.
3780 #define SKB_SGO_CB_OFFSET 32
3781 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
3783 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3785 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3786 SKB_GSO_CB(inner_skb
)->mac_offset
;
3789 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3791 int new_headroom
, headroom
;
3794 headroom
= skb_headroom(skb
);
3795 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3799 new_headroom
= skb_headroom(skb
);
3800 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3804 static inline void gso_reset_checksum(struct sk_buff
*skb
, __wsum res
)
3806 /* Do not update partial checksums if remote checksum is enabled. */
3807 if (skb
->remcsum_offload
)
3810 SKB_GSO_CB(skb
)->csum
= res
;
3811 SKB_GSO_CB(skb
)->csum_start
= skb_checksum_start(skb
) - skb
->head
;
3814 /* Compute the checksum for a gso segment. First compute the checksum value
3815 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3816 * then add in skb->csum (checksum from csum_start to end of packet).
3817 * skb->csum and csum_start are then updated to reflect the checksum of the
3818 * resultant packet starting from the transport header-- the resultant checksum
3819 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3822 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3824 unsigned char *csum_start
= skb_transport_header(skb
);
3825 int plen
= (skb
->head
+ SKB_GSO_CB(skb
)->csum_start
) - csum_start
;
3826 __wsum partial
= SKB_GSO_CB(skb
)->csum
;
3828 SKB_GSO_CB(skb
)->csum
= res
;
3829 SKB_GSO_CB(skb
)->csum_start
= csum_start
- skb
->head
;
3831 return csum_fold(csum_partial(csum_start
, plen
, partial
));
3834 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3836 return skb_shinfo(skb
)->gso_size
;
3839 /* Note: Should be called only if skb_is_gso(skb) is true */
3840 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3842 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3845 static inline void skb_gso_reset(struct sk_buff
*skb
)
3847 skb_shinfo(skb
)->gso_size
= 0;
3848 skb_shinfo(skb
)->gso_segs
= 0;
3849 skb_shinfo(skb
)->gso_type
= 0;
3852 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3854 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3856 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3857 * wanted then gso_type will be set. */
3858 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3860 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3861 unlikely(shinfo
->gso_type
== 0)) {
3862 __skb_warn_lro_forwarding(skb
);
3868 static inline void skb_forward_csum(struct sk_buff
*skb
)
3870 /* Unfortunately we don't support this one. Any brave souls? */
3871 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3872 skb
->ip_summed
= CHECKSUM_NONE
;
3876 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3877 * @skb: skb to check
3879 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3880 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3881 * use this helper, to document places where we make this assertion.
3883 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3886 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3890 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3892 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3893 struct sk_buff
*skb_checksum_trimmed(struct sk_buff
*skb
,
3894 unsigned int transport_len
,
3895 __sum16(*skb_chkf
)(struct sk_buff
*skb
));
3898 * skb_head_is_locked - Determine if the skb->head is locked down
3899 * @skb: skb to check
3901 * The head on skbs build around a head frag can be removed if they are
3902 * not cloned. This function returns true if the skb head is locked down
3903 * due to either being allocated via kmalloc, or by being a clone with
3904 * multiple references to the head.
3906 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3908 return !skb
->head_frag
|| skb_cloned(skb
);
3912 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3916 * skb_gso_network_seglen is used to determine the real size of the
3917 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3919 * The MAC/L2 header is not accounted for.
3921 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3923 unsigned int hdr_len
= skb_transport_header(skb
) -
3924 skb_network_header(skb
);
3925 return hdr_len
+ skb_gso_transport_seglen(skb
);
3928 /* Local Checksum Offload.
3929 * Compute outer checksum based on the assumption that the
3930 * inner checksum will be offloaded later.
3931 * See Documentation/networking/checksum-offloads.txt for
3932 * explanation of how this works.
3933 * Fill in outer checksum adjustment (e.g. with sum of outer
3934 * pseudo-header) before calling.
3935 * Also ensure that inner checksum is in linear data area.
3937 static inline __wsum
lco_csum(struct sk_buff
*skb
)
3939 unsigned char *csum_start
= skb_checksum_start(skb
);
3940 unsigned char *l4_hdr
= skb_transport_header(skb
);
3943 /* Start with complement of inner checksum adjustment */
3944 partial
= ~csum_unfold(*(__force __sum16
*)(csum_start
+
3947 /* Add in checksum of our headers (incl. outer checksum
3948 * adjustment filled in by caller) and return result.
3950 return csum_partial(l4_hdr
, csum_start
- l4_hdr
, partial
);
3953 #endif /* __KERNEL__ */
3954 #endif /* _LINUX_SKBUFF_H */