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.
113 * skb->csum_level indicates the number of consecutive checksums found in
114 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
115 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
116 * and a device is able to verify the checksums for UDP (possibly zero),
117 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
118 * two. If the device were only able to verify the UDP checksum and not
119 * GRE, either because it doesn't support GRE checksum of because GRE
120 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
121 * not considered in this case).
125 * This is the most generic way. The device supplied checksum of the _whole_
126 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
127 * hardware doesn't need to parse L3/L4 headers to implement this.
129 * Note: Even if device supports only some protocols, but is able to produce
130 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
134 * A checksum is set up to be offloaded to a device as described in the
135 * output description for CHECKSUM_PARTIAL. This may occur on a packet
136 * received directly from another Linux OS, e.g., a virtualized Linux kernel
137 * on the same host, or it may be set in the input path in GRO or remote
138 * checksum offload. For the purposes of checksum verification, the checksum
139 * referred to by skb->csum_start + skb->csum_offset and any preceding
140 * checksums in the packet are considered verified. Any checksums in the
141 * packet that are after the checksum being offloaded are not considered to
144 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
145 * in the skb->ip_summed for a packet. Values are:
149 * The driver is required to checksum the packet as seen by hard_start_xmit()
150 * from skb->csum_start up to the end, and to record/write the checksum at
151 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
152 * csum_start and csum_offset values are valid values given the length and
153 * offset of the packet, however they should not attempt to validate that the
154 * checksum refers to a legitimate transport layer checksum-- it is the
155 * purview of the stack to validate that csum_start and csum_offset are set
158 * When the stack requests checksum offload for a packet, the driver MUST
159 * ensure that the checksum is set correctly. A driver can either offload the
160 * checksum calculation to the device, or call skb_checksum_help (in the case
161 * that the device does not support offload for a particular checksum).
163 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
164 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
165 * checksum offload capability. If a device has limited checksum capabilities
166 * (for instance can only perform NETIF_F_IP_CSUM or NETIF_F_IPV6_CSUM as
167 * described above) a helper function can be called to resolve
168 * CHECKSUM_PARTIAL. The helper functions are skb_csum_off_chk*. The helper
169 * function takes a spec argument that describes the protocol layer that is
170 * supported for checksum offload and can be called for each packet. If a
171 * packet does not match the specification for offload, skb_checksum_help
172 * 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 ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
193 * accordingly. Note the there is no indication in the skbuff that the
194 * CHECKSUM_PARTIAL refers to an SCTP checksum, a driver that supports
195 * both IP checksum offload and SCTP CRC offload must verify which offload
196 * is configured for a packet presumably by inspecting packet headers.
198 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
199 * offloading the FCOE CRC in a packet. To perform this offload the stack
200 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
201 * accordingly. Note the there is no indication in the skbuff that the
202 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
203 * both IP checksum offload and FCOE CRC offload must verify which offload
204 * is configured for a packet presumably by inspecting packet headers.
206 * E. Checksumming on output with GSO.
208 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
209 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
210 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
211 * part of the GSO operation is implied. If a checksum is being offloaded
212 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
213 * are set to refer to the outermost checksum being offload (two offloaded
214 * checksums are possible with UDP encapsulation).
217 /* Don't change this without changing skb_csum_unnecessary! */
218 #define CHECKSUM_NONE 0
219 #define CHECKSUM_UNNECESSARY 1
220 #define CHECKSUM_COMPLETE 2
221 #define CHECKSUM_PARTIAL 3
223 /* Maximum value in skb->csum_level */
224 #define SKB_MAX_CSUM_LEVEL 3
226 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
227 #define SKB_WITH_OVERHEAD(X) \
228 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
229 #define SKB_MAX_ORDER(X, ORDER) \
230 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
231 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
232 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
234 /* return minimum truesize of one skb containing X bytes of data */
235 #define SKB_TRUESIZE(X) ((X) + \
236 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
237 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
241 struct pipe_inode_info
;
245 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
246 struct nf_conntrack
{
251 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
252 struct nf_bridge_info
{
255 BRNF_PROTO_UNCHANGED
,
263 struct net_device
*physindev
;
265 /* always valid & non-NULL from FORWARD on, for physdev match */
266 struct net_device
*physoutdev
;
268 /* prerouting: detect dnat in orig/reply direction */
270 struct in6_addr ipv6_daddr
;
272 /* after prerouting + nat detected: store original source
273 * mac since neigh resolution overwrites it, only used while
274 * skb is out in neigh layer.
276 char neigh_header
[8];
281 struct sk_buff_head
{
282 /* These two members must be first. */
283 struct sk_buff
*next
;
284 struct sk_buff
*prev
;
292 /* To allow 64K frame to be packed as single skb without frag_list we
293 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
294 * buffers which do not start on a page boundary.
296 * Since GRO uses frags we allocate at least 16 regardless of page
299 #if (65536/PAGE_SIZE + 1) < 16
300 #define MAX_SKB_FRAGS 16UL
302 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
304 extern int sysctl_max_skb_frags
;
306 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
307 * segment using its current segmentation instead.
309 #define GSO_BY_FRAGS 0xFFFF
311 typedef struct skb_frag_struct skb_frag_t
;
313 struct skb_frag_struct
{
317 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
326 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
331 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
336 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
341 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
346 #define HAVE_HW_TIME_STAMP
349 * struct skb_shared_hwtstamps - hardware time stamps
350 * @hwtstamp: hardware time stamp transformed into duration
351 * since arbitrary point in time
353 * Software time stamps generated by ktime_get_real() are stored in
356 * hwtstamps can only be compared against other hwtstamps from
359 * This structure is attached to packets as part of the
360 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
362 struct skb_shared_hwtstamps
{
366 /* Definitions for tx_flags in struct skb_shared_info */
368 /* generate hardware time stamp */
369 SKBTX_HW_TSTAMP
= 1 << 0,
371 /* generate software time stamp when queueing packet to NIC */
372 SKBTX_SW_TSTAMP
= 1 << 1,
374 /* device driver is going to provide hardware time stamp */
375 SKBTX_IN_PROGRESS
= 1 << 2,
377 /* device driver supports TX zero-copy buffers */
378 SKBTX_DEV_ZEROCOPY
= 1 << 3,
380 /* generate wifi status information (where possible) */
381 SKBTX_WIFI_STATUS
= 1 << 4,
383 /* This indicates at least one fragment might be overwritten
384 * (as in vmsplice(), sendfile() ...)
385 * If we need to compute a TX checksum, we'll need to copy
386 * all frags to avoid possible bad checksum
388 SKBTX_SHARED_FRAG
= 1 << 5,
390 /* generate software time stamp when entering packet scheduling */
391 SKBTX_SCHED_TSTAMP
= 1 << 6,
394 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
396 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
399 * The callback notifies userspace to release buffers when skb DMA is done in
400 * lower device, the skb last reference should be 0 when calling this.
401 * The zerocopy_success argument is true if zero copy transmit occurred,
402 * false on data copy or out of memory error caused by data copy attempt.
403 * The ctx field is used to track device context.
404 * The desc field is used to track userspace buffer index.
407 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
412 /* This data is invariant across clones and lives at
413 * the end of the header data, ie. at skb->end.
415 struct skb_shared_info
{
416 unsigned short _unused
;
417 unsigned char nr_frags
;
419 unsigned short gso_size
;
420 /* Warning: this field is not always filled in (UFO)! */
421 unsigned short gso_segs
;
422 struct sk_buff
*frag_list
;
423 struct skb_shared_hwtstamps hwtstamps
;
424 unsigned int gso_type
;
429 * Warning : all fields before dataref are cleared in __alloc_skb()
433 /* Intermediate layers must ensure that destructor_arg
434 * remains valid until skb destructor */
435 void * destructor_arg
;
437 /* must be last field, see pskb_expand_head() */
438 skb_frag_t frags
[MAX_SKB_FRAGS
];
441 /* We divide dataref into two halves. The higher 16 bits hold references
442 * to the payload part of skb->data. The lower 16 bits hold references to
443 * the entire skb->data. A clone of a headerless skb holds the length of
444 * the header in skb->hdr_len.
446 * All users must obey the rule that the skb->data reference count must be
447 * greater than or equal to the payload reference count.
449 * Holding a reference to the payload part means that the user does not
450 * care about modifications to the header part of skb->data.
452 #define SKB_DATAREF_SHIFT 16
453 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
457 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
458 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
459 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
463 SKB_GSO_TCPV4
= 1 << 0,
464 SKB_GSO_UDP
= 1 << 1,
466 /* This indicates the skb is from an untrusted source. */
467 SKB_GSO_DODGY
= 1 << 2,
469 /* This indicates the tcp segment has CWR set. */
470 SKB_GSO_TCP_ECN
= 1 << 3,
472 SKB_GSO_TCP_FIXEDID
= 1 << 4,
474 SKB_GSO_TCPV6
= 1 << 5,
476 SKB_GSO_FCOE
= 1 << 6,
478 SKB_GSO_GRE
= 1 << 7,
480 SKB_GSO_GRE_CSUM
= 1 << 8,
482 SKB_GSO_IPXIP4
= 1 << 9,
484 SKB_GSO_IPXIP6
= 1 << 10,
486 SKB_GSO_UDP_TUNNEL
= 1 << 11,
488 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 12,
490 SKB_GSO_PARTIAL
= 1 << 13,
492 SKB_GSO_TUNNEL_REMCSUM
= 1 << 14,
494 SKB_GSO_SCTP
= 1 << 15,
496 SKB_GSO_ESP
= 1 << 16,
499 #if BITS_PER_LONG > 32
500 #define NET_SKBUFF_DATA_USES_OFFSET 1
503 #ifdef NET_SKBUFF_DATA_USES_OFFSET
504 typedef unsigned int sk_buff_data_t
;
506 typedef unsigned char *sk_buff_data_t
;
510 * struct sk_buff - socket buffer
511 * @next: Next buffer in list
512 * @prev: Previous buffer in list
513 * @tstamp: Time we arrived/left
514 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
515 * @sk: Socket we are owned by
516 * @dev: Device we arrived on/are leaving by
517 * @cb: Control buffer. Free for use by every layer. Put private vars here
518 * @_skb_refdst: destination entry (with norefcount bit)
519 * @sp: the security path, used for xfrm
520 * @len: Length of actual data
521 * @data_len: Data length
522 * @mac_len: Length of link layer header
523 * @hdr_len: writable header length of cloned skb
524 * @csum: Checksum (must include start/offset pair)
525 * @csum_start: Offset from skb->head where checksumming should start
526 * @csum_offset: Offset from csum_start where checksum should be stored
527 * @priority: Packet queueing priority
528 * @ignore_df: allow local fragmentation
529 * @cloned: Head may be cloned (check refcnt to be sure)
530 * @ip_summed: Driver fed us an IP checksum
531 * @nohdr: Payload reference only, must not modify header
532 * @pkt_type: Packet class
533 * @fclone: skbuff clone status
534 * @ipvs_property: skbuff is owned by ipvs
535 * @tc_skip_classify: do not classify packet. set by IFB device
536 * @tc_at_ingress: used within tc_classify to distinguish in/egress
537 * @tc_redirected: packet was redirected by a tc action
538 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect
539 * @peeked: this packet has been seen already, so stats have been
540 * done for it, don't do them again
541 * @nf_trace: netfilter packet trace flag
542 * @protocol: Packet protocol from driver
543 * @destructor: Destruct function
544 * @_nfct: Associated connection, if any (with nfctinfo bits)
545 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
546 * @skb_iif: ifindex of device we arrived on
547 * @tc_index: Traffic control index
548 * @hash: the packet hash
549 * @queue_mapping: Queue mapping for multiqueue devices
550 * @xmit_more: More SKBs are pending for this queue
551 * @ndisc_nodetype: router type (from link layer)
552 * @ooo_okay: allow the mapping of a socket to a queue to be changed
553 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
555 * @sw_hash: indicates hash was computed in software stack
556 * @wifi_acked_valid: wifi_acked was set
557 * @wifi_acked: whether frame was acked on wifi or not
558 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
559 * @dst_pending_confirm: need to confirm neighbour
560 * @napi_id: id of the NAPI struct this skb came from
561 * @secmark: security marking
562 * @mark: Generic packet mark
563 * @vlan_proto: vlan encapsulation protocol
564 * @vlan_tci: vlan tag control information
565 * @inner_protocol: Protocol (encapsulation)
566 * @inner_transport_header: Inner transport layer header (encapsulation)
567 * @inner_network_header: Network layer header (encapsulation)
568 * @inner_mac_header: Link layer header (encapsulation)
569 * @transport_header: Transport layer header
570 * @network_header: Network layer header
571 * @mac_header: Link layer header
572 * @tail: Tail pointer
574 * @head: Head of buffer
575 * @data: Data head pointer
576 * @truesize: Buffer size
577 * @users: User count - see {datagram,tcp}.c
583 /* These two members must be first. */
584 struct sk_buff
*next
;
585 struct sk_buff
*prev
;
592 struct rb_node rbnode
; /* used in netem & tcp stack */
597 struct net_device
*dev
;
598 /* Some protocols might use this space to store information,
599 * while device pointer would be NULL.
600 * UDP receive path is one user.
602 unsigned long dev_scratch
;
605 * This is the control buffer. It is free to use for every
606 * layer. Please put your private variables there. If you
607 * want to keep them across layers you have to do a skb_clone()
608 * first. This is owned by whoever has the skb queued ATM.
610 char cb
[48] __aligned(8);
612 unsigned long _skb_refdst
;
613 void (*destructor
)(struct sk_buff
*skb
);
617 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
620 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
621 struct nf_bridge_info
*nf_bridge
;
628 /* Following fields are _not_ copied in __copy_skb_header()
629 * Note that queue_mapping is here mostly to fill a hole.
631 kmemcheck_bitfield_begin(flags1
);
634 /* if you move cloned around you also must adapt those constants */
635 #ifdef __BIG_ENDIAN_BITFIELD
636 #define CLONED_MASK (1 << 7)
638 #define CLONED_MASK 1
640 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
642 __u8 __cloned_offset
[0];
649 __unused
:1; /* one bit hole */
650 kmemcheck_bitfield_end(flags1
);
652 /* fields enclosed in headers_start/headers_end are copied
653 * using a single memcpy() in __copy_skb_header()
656 __u32 headers_start
[0];
659 /* if you move pkt_type around you also must adapt those constants */
660 #ifdef __BIG_ENDIAN_BITFIELD
661 #define PKT_TYPE_MAX (7 << 5)
663 #define PKT_TYPE_MAX 7
665 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
667 __u8 __pkt_type_offset
[0];
677 __u8 wifi_acked_valid
:1;
681 /* Indicates the inner headers are valid in the skbuff. */
682 __u8 encapsulation
:1;
683 __u8 encap_hdr_csum
:1;
685 __u8 csum_complete_sw
:1;
689 __u8 dst_pending_confirm
:1;
690 #ifdef CONFIG_IPV6_NDISC_NODETYPE
691 __u8 ndisc_nodetype
:2;
693 __u8 ipvs_property
:1;
694 __u8 inner_protocol_type
:1;
695 __u8 remcsum_offload
:1;
696 #ifdef CONFIG_NET_SWITCHDEV
697 __u8 offload_fwd_mark
:1;
699 #ifdef CONFIG_NET_CLS_ACT
700 __u8 tc_skip_classify
:1;
701 __u8 tc_at_ingress
:1;
702 __u8 tc_redirected
:1;
703 __u8 tc_from_ingress
:1;
706 #ifdef CONFIG_NET_SCHED
707 __u16 tc_index
; /* traffic control index */
722 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
724 unsigned int napi_id
;
725 unsigned int sender_cpu
;
728 #ifdef CONFIG_NETWORK_SECMARK
734 __u32 reserved_tailroom
;
738 __be16 inner_protocol
;
742 __u16 inner_transport_header
;
743 __u16 inner_network_header
;
744 __u16 inner_mac_header
;
747 __u16 transport_header
;
748 __u16 network_header
;
752 __u32 headers_end
[0];
755 /* These elements must be at the end, see alloc_skb() for details. */
760 unsigned int truesize
;
766 * Handling routines are only of interest to the kernel
768 #include <linux/slab.h>
771 #define SKB_ALLOC_FCLONE 0x01
772 #define SKB_ALLOC_RX 0x02
773 #define SKB_ALLOC_NAPI 0x04
775 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
776 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
778 return unlikely(skb
->pfmemalloc
);
782 * skb might have a dst pointer attached, refcounted or not.
783 * _skb_refdst low order bit is set if refcount was _not_ taken
785 #define SKB_DST_NOREF 1UL
786 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
788 #define SKB_NFCT_PTRMASK ~(7UL)
790 * skb_dst - returns skb dst_entry
793 * Returns skb dst_entry, regardless of reference taken or not.
795 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
797 /* If refdst was not refcounted, check we still are in a
798 * rcu_read_lock section
800 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
801 !rcu_read_lock_held() &&
802 !rcu_read_lock_bh_held());
803 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
807 * skb_dst_set - sets skb dst
811 * Sets skb dst, assuming a reference was taken on dst and should
812 * be released by skb_dst_drop()
814 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
816 skb
->_skb_refdst
= (unsigned long)dst
;
820 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
824 * Sets skb dst, assuming a reference was not taken on dst.
825 * If dst entry is cached, we do not take reference and dst_release
826 * will be avoided by refdst_drop. If dst entry is not cached, we take
827 * reference, so that last dst_release can destroy the dst immediately.
829 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
831 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
832 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
836 * skb_dst_is_noref - Test if skb dst isn't refcounted
839 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
841 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
844 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
846 return (struct rtable
*)skb_dst(skb
);
849 /* For mangling skb->pkt_type from user space side from applications
850 * such as nft, tc, etc, we only allow a conservative subset of
851 * possible pkt_types to be set.
853 static inline bool skb_pkt_type_ok(u32 ptype
)
855 return ptype
<= PACKET_OTHERHOST
;
858 void kfree_skb(struct sk_buff
*skb
);
859 void kfree_skb_list(struct sk_buff
*segs
);
860 void skb_tx_error(struct sk_buff
*skb
);
861 void consume_skb(struct sk_buff
*skb
);
862 void __kfree_skb(struct sk_buff
*skb
);
863 extern struct kmem_cache
*skbuff_head_cache
;
865 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
866 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
867 bool *fragstolen
, int *delta_truesize
);
869 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
871 struct sk_buff
*__build_skb(void *data
, unsigned int frag_size
);
872 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
873 static inline struct sk_buff
*alloc_skb(unsigned int size
,
876 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
879 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
880 unsigned long data_len
,
885 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
886 struct sk_buff_fclones
{
895 * skb_fclone_busy - check if fclone is busy
899 * Returns true if skb is a fast clone, and its clone is not freed.
900 * Some drivers call skb_orphan() in their ndo_start_xmit(),
901 * so we also check that this didnt happen.
903 static inline bool skb_fclone_busy(const struct sock
*sk
,
904 const struct sk_buff
*skb
)
906 const struct sk_buff_fclones
*fclones
;
908 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
910 return skb
->fclone
== SKB_FCLONE_ORIG
&&
911 atomic_read(&fclones
->fclone_ref
) > 1 &&
912 fclones
->skb2
.sk
== sk
;
915 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
918 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
921 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
922 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
924 return __alloc_skb_head(priority
, -1);
927 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
928 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
929 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
930 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
931 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
932 gfp_t gfp_mask
, bool fclone
);
933 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
936 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
939 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
940 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
941 unsigned int headroom
);
942 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
943 int newtailroom
, gfp_t priority
);
944 int skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
945 int offset
, int len
);
946 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
,
948 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
949 int skb_pad(struct sk_buff
*skb
, int pad
);
950 #define dev_kfree_skb(a) consume_skb(a)
952 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
953 int getfrag(void *from
, char *to
, int offset
,
954 int len
, int odd
, struct sk_buff
*skb
),
955 void *from
, int length
);
957 int skb_append_pagefrags(struct sk_buff
*skb
, struct page
*page
,
958 int offset
, size_t size
);
960 struct skb_seq_state
{
964 __u32 stepped_offset
;
965 struct sk_buff
*root_skb
;
966 struct sk_buff
*cur_skb
;
970 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
971 unsigned int to
, struct skb_seq_state
*st
);
972 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
973 struct skb_seq_state
*st
);
974 void skb_abort_seq_read(struct skb_seq_state
*st
);
976 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
977 unsigned int to
, struct ts_config
*config
);
980 * Packet hash types specify the type of hash in skb_set_hash.
982 * Hash types refer to the protocol layer addresses which are used to
983 * construct a packet's hash. The hashes are used to differentiate or identify
984 * flows of the protocol layer for the hash type. Hash types are either
985 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
987 * Properties of hashes:
989 * 1) Two packets in different flows have different hash values
990 * 2) Two packets in the same flow should have the same hash value
992 * A hash at a higher layer is considered to be more specific. A driver should
993 * set the most specific hash possible.
995 * A driver cannot indicate a more specific hash than the layer at which a hash
996 * was computed. For instance an L3 hash cannot be set as an L4 hash.
998 * A driver may indicate a hash level which is less specific than the
999 * actual layer the hash was computed on. For instance, a hash computed
1000 * at L4 may be considered an L3 hash. This should only be done if the
1001 * driver can't unambiguously determine that the HW computed the hash at
1002 * the higher layer. Note that the "should" in the second property above
1005 enum pkt_hash_types
{
1006 PKT_HASH_TYPE_NONE
, /* Undefined type */
1007 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
1008 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
1009 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
1012 static inline void skb_clear_hash(struct sk_buff
*skb
)
1019 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
1022 skb_clear_hash(skb
);
1026 __skb_set_hash(struct sk_buff
*skb
, __u32 hash
, bool is_sw
, bool is_l4
)
1028 skb
->l4_hash
= is_l4
;
1029 skb
->sw_hash
= is_sw
;
1034 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
1036 /* Used by drivers to set hash from HW */
1037 __skb_set_hash(skb
, hash
, false, type
== PKT_HASH_TYPE_L4
);
1041 __skb_set_sw_hash(struct sk_buff
*skb
, __u32 hash
, bool is_l4
)
1043 __skb_set_hash(skb
, hash
, true, is_l4
);
1046 void __skb_get_hash(struct sk_buff
*skb
);
1047 u32
__skb_get_hash_symmetric(const struct sk_buff
*skb
);
1048 u32
skb_get_poff(const struct sk_buff
*skb
);
1049 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
1050 const struct flow_keys
*keys
, int hlen
);
1051 __be32
__skb_flow_get_ports(const struct sk_buff
*skb
, int thoff
, u8 ip_proto
,
1052 void *data
, int hlen_proto
);
1054 static inline __be32
skb_flow_get_ports(const struct sk_buff
*skb
,
1055 int thoff
, u8 ip_proto
)
1057 return __skb_flow_get_ports(skb
, thoff
, ip_proto
, NULL
, 0);
1060 void skb_flow_dissector_init(struct flow_dissector
*flow_dissector
,
1061 const struct flow_dissector_key
*key
,
1062 unsigned int key_count
);
1064 bool __skb_flow_dissect(const struct sk_buff
*skb
,
1065 struct flow_dissector
*flow_dissector
,
1066 void *target_container
,
1067 void *data
, __be16 proto
, int nhoff
, int hlen
,
1068 unsigned int flags
);
1070 static inline bool skb_flow_dissect(const struct sk_buff
*skb
,
1071 struct flow_dissector
*flow_dissector
,
1072 void *target_container
, unsigned int flags
)
1074 return __skb_flow_dissect(skb
, flow_dissector
, target_container
,
1075 NULL
, 0, 0, 0, flags
);
1078 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff
*skb
,
1079 struct flow_keys
*flow
,
1082 memset(flow
, 0, sizeof(*flow
));
1083 return __skb_flow_dissect(skb
, &flow_keys_dissector
, flow
,
1084 NULL
, 0, 0, 0, flags
);
1087 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys
*flow
,
1088 void *data
, __be16 proto
,
1089 int nhoff
, int hlen
,
1092 memset(flow
, 0, sizeof(*flow
));
1093 return __skb_flow_dissect(NULL
, &flow_keys_buf_dissector
, flow
,
1094 data
, proto
, nhoff
, hlen
, flags
);
1097 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
1099 if (!skb
->l4_hash
&& !skb
->sw_hash
)
1100 __skb_get_hash(skb
);
1105 __u32
__skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
);
1107 static inline __u32
skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
)
1109 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1110 struct flow_keys keys
;
1111 __u32 hash
= __get_hash_from_flowi6(fl6
, &keys
);
1113 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1119 __u32
__skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl
);
1121 static inline __u32
skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl4
)
1123 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1124 struct flow_keys keys
;
1125 __u32 hash
= __get_hash_from_flowi4(fl4
, &keys
);
1127 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1133 __u32
skb_get_hash_perturb(const struct sk_buff
*skb
, u32 perturb
);
1135 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
1140 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
1142 to
->hash
= from
->hash
;
1143 to
->sw_hash
= from
->sw_hash
;
1144 to
->l4_hash
= from
->l4_hash
;
1147 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1148 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1150 return skb
->head
+ skb
->end
;
1153 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1158 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1163 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1165 return skb
->end
- skb
->head
;
1170 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1172 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
1174 return &skb_shinfo(skb
)->hwtstamps
;
1178 * skb_queue_empty - check if a queue is empty
1181 * Returns true if the queue is empty, false otherwise.
1183 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1185 return list
->next
== (const struct sk_buff
*) list
;
1189 * skb_queue_is_last - check if skb is the last entry in the queue
1193 * Returns true if @skb is the last buffer on the list.
1195 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1196 const struct sk_buff
*skb
)
1198 return skb
->next
== (const struct sk_buff
*) list
;
1202 * skb_queue_is_first - check if skb is the first entry in the queue
1206 * Returns true if @skb is the first buffer on the list.
1208 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1209 const struct sk_buff
*skb
)
1211 return skb
->prev
== (const struct sk_buff
*) list
;
1215 * skb_queue_next - return the next packet in the queue
1217 * @skb: current buffer
1219 * Return the next packet in @list after @skb. It is only valid to
1220 * call this if skb_queue_is_last() evaluates to false.
1222 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1223 const struct sk_buff
*skb
)
1225 /* This BUG_ON may seem severe, but if we just return then we
1226 * are going to dereference garbage.
1228 BUG_ON(skb_queue_is_last(list
, skb
));
1233 * skb_queue_prev - return the prev packet in the queue
1235 * @skb: current buffer
1237 * Return the prev packet in @list before @skb. It is only valid to
1238 * call this if skb_queue_is_first() evaluates to false.
1240 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1241 const struct sk_buff
*skb
)
1243 /* This BUG_ON may seem severe, but if we just return then we
1244 * are going to dereference garbage.
1246 BUG_ON(skb_queue_is_first(list
, skb
));
1251 * skb_get - reference buffer
1252 * @skb: buffer to reference
1254 * Makes another reference to a socket buffer and returns a pointer
1257 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1259 atomic_inc(&skb
->users
);
1264 * If users == 1, we are the only owner and are can avoid redundant
1269 * skb_cloned - is the buffer a clone
1270 * @skb: buffer to check
1272 * Returns true if the buffer was generated with skb_clone() and is
1273 * one of multiple shared copies of the buffer. Cloned buffers are
1274 * shared data so must not be written to under normal circumstances.
1276 static inline int skb_cloned(const struct sk_buff
*skb
)
1278 return skb
->cloned
&&
1279 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1282 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1284 might_sleep_if(gfpflags_allow_blocking(pri
));
1286 if (skb_cloned(skb
))
1287 return pskb_expand_head(skb
, 0, 0, pri
);
1293 * skb_header_cloned - is the header a clone
1294 * @skb: buffer to check
1296 * Returns true if modifying the header part of the buffer requires
1297 * the data to be copied.
1299 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1306 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1307 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1308 return dataref
!= 1;
1311 static inline int skb_header_unclone(struct sk_buff
*skb
, gfp_t pri
)
1313 might_sleep_if(gfpflags_allow_blocking(pri
));
1315 if (skb_header_cloned(skb
))
1316 return pskb_expand_head(skb
, 0, 0, pri
);
1322 * skb_header_release - release reference to header
1323 * @skb: buffer to operate on
1325 * Drop a reference to the header part of the buffer. This is done
1326 * by acquiring a payload reference. You must not read from the header
1327 * part of skb->data after this.
1328 * Note : Check if you can use __skb_header_release() instead.
1330 static inline void skb_header_release(struct sk_buff
*skb
)
1334 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1338 * __skb_header_release - release reference to header
1339 * @skb: buffer to operate on
1341 * Variant of skb_header_release() assuming skb is private to caller.
1342 * We can avoid one atomic operation.
1344 static inline void __skb_header_release(struct sk_buff
*skb
)
1347 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1352 * skb_shared - is the buffer shared
1353 * @skb: buffer to check
1355 * Returns true if more than one person has a reference to this
1358 static inline int skb_shared(const struct sk_buff
*skb
)
1360 return atomic_read(&skb
->users
) != 1;
1364 * skb_share_check - check if buffer is shared and if so clone it
1365 * @skb: buffer to check
1366 * @pri: priority for memory allocation
1368 * If the buffer is shared the buffer is cloned and the old copy
1369 * drops a reference. A new clone with a single reference is returned.
1370 * If the buffer is not shared the original buffer is returned. When
1371 * being called from interrupt status or with spinlocks held pri must
1374 * NULL is returned on a memory allocation failure.
1376 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1378 might_sleep_if(gfpflags_allow_blocking(pri
));
1379 if (skb_shared(skb
)) {
1380 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1392 * Copy shared buffers into a new sk_buff. We effectively do COW on
1393 * packets to handle cases where we have a local reader and forward
1394 * and a couple of other messy ones. The normal one is tcpdumping
1395 * a packet thats being forwarded.
1399 * skb_unshare - make a copy of a shared buffer
1400 * @skb: buffer to check
1401 * @pri: priority for memory allocation
1403 * If the socket buffer is a clone then this function creates a new
1404 * copy of the data, drops a reference count on the old copy and returns
1405 * the new copy with the reference count at 1. If the buffer is not a clone
1406 * the original buffer is returned. When called with a spinlock held or
1407 * from interrupt state @pri must be %GFP_ATOMIC
1409 * %NULL is returned on a memory allocation failure.
1411 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1414 might_sleep_if(gfpflags_allow_blocking(pri
));
1415 if (skb_cloned(skb
)) {
1416 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1418 /* Free our shared copy */
1429 * skb_peek - peek at the head of an &sk_buff_head
1430 * @list_: list to peek at
1432 * Peek an &sk_buff. Unlike most other operations you _MUST_
1433 * be careful with this one. A peek leaves the buffer on the
1434 * list and someone else may run off with it. You must hold
1435 * the appropriate locks or have a private queue to do this.
1437 * Returns %NULL for an empty list or a pointer to the head element.
1438 * The reference count is not incremented and the reference is therefore
1439 * volatile. Use with caution.
1441 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1443 struct sk_buff
*skb
= list_
->next
;
1445 if (skb
== (struct sk_buff
*)list_
)
1451 * skb_peek_next - peek skb following the given one from a queue
1452 * @skb: skb to start from
1453 * @list_: list to peek at
1455 * Returns %NULL when the end of the list is met or a pointer to the
1456 * next element. The reference count is not incremented and the
1457 * reference is therefore volatile. Use with caution.
1459 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1460 const struct sk_buff_head
*list_
)
1462 struct sk_buff
*next
= skb
->next
;
1464 if (next
== (struct sk_buff
*)list_
)
1470 * skb_peek_tail - peek at the tail of an &sk_buff_head
1471 * @list_: list to peek at
1473 * Peek an &sk_buff. Unlike most other operations you _MUST_
1474 * be careful with this one. A peek leaves the buffer on the
1475 * list and someone else may run off with it. You must hold
1476 * the appropriate locks or have a private queue to do this.
1478 * Returns %NULL for an empty list or a pointer to the tail element.
1479 * The reference count is not incremented and the reference is therefore
1480 * volatile. Use with caution.
1482 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1484 struct sk_buff
*skb
= list_
->prev
;
1486 if (skb
== (struct sk_buff
*)list_
)
1493 * skb_queue_len - get queue length
1494 * @list_: list to measure
1496 * Return the length of an &sk_buff queue.
1498 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1504 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1505 * @list: queue to initialize
1507 * This initializes only the list and queue length aspects of
1508 * an sk_buff_head object. This allows to initialize the list
1509 * aspects of an sk_buff_head without reinitializing things like
1510 * the spinlock. It can also be used for on-stack sk_buff_head
1511 * objects where the spinlock is known to not be used.
1513 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1515 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1520 * This function creates a split out lock class for each invocation;
1521 * this is needed for now since a whole lot of users of the skb-queue
1522 * infrastructure in drivers have different locking usage (in hardirq)
1523 * than the networking core (in softirq only). In the long run either the
1524 * network layer or drivers should need annotation to consolidate the
1525 * main types of usage into 3 classes.
1527 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1529 spin_lock_init(&list
->lock
);
1530 __skb_queue_head_init(list
);
1533 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1534 struct lock_class_key
*class)
1536 skb_queue_head_init(list
);
1537 lockdep_set_class(&list
->lock
, class);
1541 * Insert an sk_buff on a list.
1543 * The "__skb_xxxx()" functions are the non-atomic ones that
1544 * can only be called with interrupts disabled.
1546 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1547 struct sk_buff_head
*list
);
1548 static inline void __skb_insert(struct sk_buff
*newsk
,
1549 struct sk_buff
*prev
, struct sk_buff
*next
,
1550 struct sk_buff_head
*list
)
1554 next
->prev
= prev
->next
= newsk
;
1558 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1559 struct sk_buff
*prev
,
1560 struct sk_buff
*next
)
1562 struct sk_buff
*first
= list
->next
;
1563 struct sk_buff
*last
= list
->prev
;
1573 * skb_queue_splice - join two skb lists, this is designed for stacks
1574 * @list: the new list to add
1575 * @head: the place to add it in the first list
1577 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1578 struct sk_buff_head
*head
)
1580 if (!skb_queue_empty(list
)) {
1581 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1582 head
->qlen
+= list
->qlen
;
1587 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1588 * @list: the new list to add
1589 * @head: the place to add it in the first list
1591 * The list at @list is reinitialised
1593 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1594 struct sk_buff_head
*head
)
1596 if (!skb_queue_empty(list
)) {
1597 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1598 head
->qlen
+= list
->qlen
;
1599 __skb_queue_head_init(list
);
1604 * skb_queue_splice_tail - join two skb lists, each list being a queue
1605 * @list: the new list to add
1606 * @head: the place to add it in the first list
1608 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1609 struct sk_buff_head
*head
)
1611 if (!skb_queue_empty(list
)) {
1612 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1613 head
->qlen
+= list
->qlen
;
1618 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1619 * @list: the new list to add
1620 * @head: the place to add it in the first list
1622 * Each of the lists is a queue.
1623 * The list at @list is reinitialised
1625 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1626 struct sk_buff_head
*head
)
1628 if (!skb_queue_empty(list
)) {
1629 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1630 head
->qlen
+= list
->qlen
;
1631 __skb_queue_head_init(list
);
1636 * __skb_queue_after - queue a buffer at the list head
1637 * @list: list to use
1638 * @prev: place after this buffer
1639 * @newsk: buffer to queue
1641 * Queue a buffer int the middle of a list. This function takes no locks
1642 * and you must therefore hold required locks before calling it.
1644 * A buffer cannot be placed on two lists at the same time.
1646 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1647 struct sk_buff
*prev
,
1648 struct sk_buff
*newsk
)
1650 __skb_insert(newsk
, prev
, prev
->next
, list
);
1653 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1654 struct sk_buff_head
*list
);
1656 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1657 struct sk_buff
*next
,
1658 struct sk_buff
*newsk
)
1660 __skb_insert(newsk
, next
->prev
, next
, list
);
1664 * __skb_queue_head - queue a buffer at the list head
1665 * @list: list to use
1666 * @newsk: buffer to queue
1668 * Queue a buffer at the start of a list. This function takes no locks
1669 * and you must therefore hold required locks before calling it.
1671 * A buffer cannot be placed on two lists at the same time.
1673 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1674 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1675 struct sk_buff
*newsk
)
1677 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1681 * __skb_queue_tail - queue a buffer at the list tail
1682 * @list: list to use
1683 * @newsk: buffer to queue
1685 * Queue a buffer at the end of a list. This function takes no locks
1686 * and you must therefore hold required locks before calling it.
1688 * A buffer cannot be placed on two lists at the same time.
1690 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1691 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1692 struct sk_buff
*newsk
)
1694 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1698 * remove sk_buff from list. _Must_ be called atomically, and with
1701 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1702 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1704 struct sk_buff
*next
, *prev
;
1709 skb
->next
= skb
->prev
= NULL
;
1715 * __skb_dequeue - remove from the head of the queue
1716 * @list: list to dequeue from
1718 * Remove the head of the list. This function does not take any locks
1719 * so must be used with appropriate locks held only. The head item is
1720 * returned or %NULL if the list is empty.
1722 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1723 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1725 struct sk_buff
*skb
= skb_peek(list
);
1727 __skb_unlink(skb
, list
);
1732 * __skb_dequeue_tail - remove from the tail of the queue
1733 * @list: list to dequeue from
1735 * Remove the tail of the list. This function does not take any locks
1736 * so must be used with appropriate locks held only. The tail item is
1737 * returned or %NULL if the list is empty.
1739 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1740 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1742 struct sk_buff
*skb
= skb_peek_tail(list
);
1744 __skb_unlink(skb
, list
);
1749 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1751 return skb
->data_len
;
1754 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1756 return skb
->len
- skb
->data_len
;
1759 static inline unsigned int skb_pagelen(const struct sk_buff
*skb
)
1761 unsigned int i
, len
= 0;
1763 for (i
= skb_shinfo(skb
)->nr_frags
- 1; (int)i
>= 0; i
--)
1764 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1765 return len
+ skb_headlen(skb
);
1769 * __skb_fill_page_desc - initialise a paged fragment in an skb
1770 * @skb: buffer containing fragment to be initialised
1771 * @i: paged fragment index to initialise
1772 * @page: the page to use for this fragment
1773 * @off: the offset to the data with @page
1774 * @size: the length of the data
1776 * Initialises the @i'th fragment of @skb to point to &size bytes at
1777 * offset @off within @page.
1779 * Does not take any additional reference on the fragment.
1781 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1782 struct page
*page
, int off
, int size
)
1784 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1787 * Propagate page pfmemalloc to the skb if we can. The problem is
1788 * that not all callers have unique ownership of the page but rely
1789 * on page_is_pfmemalloc doing the right thing(tm).
1791 frag
->page
.p
= page
;
1792 frag
->page_offset
= off
;
1793 skb_frag_size_set(frag
, size
);
1795 page
= compound_head(page
);
1796 if (page_is_pfmemalloc(page
))
1797 skb
->pfmemalloc
= true;
1801 * skb_fill_page_desc - initialise a paged fragment in an skb
1802 * @skb: buffer containing fragment to be initialised
1803 * @i: paged fragment index to initialise
1804 * @page: the page to use for this fragment
1805 * @off: the offset to the data with @page
1806 * @size: the length of the data
1808 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1809 * @skb to point to @size bytes at offset @off within @page. In
1810 * addition updates @skb such that @i is the last fragment.
1812 * Does not take any additional reference on the fragment.
1814 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1815 struct page
*page
, int off
, int size
)
1817 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1818 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1821 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1822 int size
, unsigned int truesize
);
1824 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1825 unsigned int truesize
);
1827 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1828 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1829 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1831 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1832 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1834 return skb
->head
+ skb
->tail
;
1837 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1839 skb
->tail
= skb
->data
- skb
->head
;
1842 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1844 skb_reset_tail_pointer(skb
);
1845 skb
->tail
+= offset
;
1848 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1849 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1854 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1856 skb
->tail
= skb
->data
;
1859 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1861 skb
->tail
= skb
->data
+ offset
;
1864 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1867 * Add data to an sk_buff
1869 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1870 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1871 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1873 unsigned char *tmp
= skb_tail_pointer(skb
);
1874 SKB_LINEAR_ASSERT(skb
);
1880 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1881 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1888 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1889 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1892 BUG_ON(skb
->len
< skb
->data_len
);
1893 return skb
->data
+= len
;
1896 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1898 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1901 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1903 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1905 if (len
> skb_headlen(skb
) &&
1906 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1909 return skb
->data
+= len
;
1912 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1914 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1917 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1919 if (likely(len
<= skb_headlen(skb
)))
1921 if (unlikely(len
> skb
->len
))
1923 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1926 void skb_condense(struct sk_buff
*skb
);
1929 * skb_headroom - bytes at buffer head
1930 * @skb: buffer to check
1932 * Return the number of bytes of free space at the head of an &sk_buff.
1934 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1936 return skb
->data
- skb
->head
;
1940 * skb_tailroom - bytes at buffer end
1941 * @skb: buffer to check
1943 * Return the number of bytes of free space at the tail of an sk_buff
1945 static inline int skb_tailroom(const struct sk_buff
*skb
)
1947 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1951 * skb_availroom - bytes at buffer end
1952 * @skb: buffer to check
1954 * Return the number of bytes of free space at the tail of an sk_buff
1955 * allocated by sk_stream_alloc()
1957 static inline int skb_availroom(const struct sk_buff
*skb
)
1959 if (skb_is_nonlinear(skb
))
1962 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1966 * skb_reserve - adjust headroom
1967 * @skb: buffer to alter
1968 * @len: bytes to move
1970 * Increase the headroom of an empty &sk_buff by reducing the tail
1971 * room. This is only allowed for an empty buffer.
1973 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1980 * skb_tailroom_reserve - adjust reserved_tailroom
1981 * @skb: buffer to alter
1982 * @mtu: maximum amount of headlen permitted
1983 * @needed_tailroom: minimum amount of reserved_tailroom
1985 * Set reserved_tailroom so that headlen can be as large as possible but
1986 * not larger than mtu and tailroom cannot be smaller than
1988 * The required headroom should already have been reserved before using
1991 static inline void skb_tailroom_reserve(struct sk_buff
*skb
, unsigned int mtu
,
1992 unsigned int needed_tailroom
)
1994 SKB_LINEAR_ASSERT(skb
);
1995 if (mtu
< skb_tailroom(skb
) - needed_tailroom
)
1996 /* use at most mtu */
1997 skb
->reserved_tailroom
= skb_tailroom(skb
) - mtu
;
1999 /* use up to all available space */
2000 skb
->reserved_tailroom
= needed_tailroom
;
2003 #define ENCAP_TYPE_ETHER 0
2004 #define ENCAP_TYPE_IPPROTO 1
2006 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
2009 skb
->inner_protocol
= protocol
;
2010 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
2013 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
2016 skb
->inner_ipproto
= ipproto
;
2017 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
2020 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
2022 skb
->inner_mac_header
= skb
->mac_header
;
2023 skb
->inner_network_header
= skb
->network_header
;
2024 skb
->inner_transport_header
= skb
->transport_header
;
2027 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
2029 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
2032 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2035 return skb
->head
+ skb
->inner_transport_header
;
2038 static inline int skb_inner_transport_offset(const struct sk_buff
*skb
)
2040 return skb_inner_transport_header(skb
) - skb
->data
;
2043 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
2045 skb
->inner_transport_header
= skb
->data
- skb
->head
;
2048 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
2051 skb_reset_inner_transport_header(skb
);
2052 skb
->inner_transport_header
+= offset
;
2055 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
2057 return skb
->head
+ skb
->inner_network_header
;
2060 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
2062 skb
->inner_network_header
= skb
->data
- skb
->head
;
2065 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
2068 skb_reset_inner_network_header(skb
);
2069 skb
->inner_network_header
+= offset
;
2072 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
2074 return skb
->head
+ skb
->inner_mac_header
;
2077 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
2079 skb
->inner_mac_header
= skb
->data
- skb
->head
;
2082 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
2085 skb_reset_inner_mac_header(skb
);
2086 skb
->inner_mac_header
+= offset
;
2088 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
2090 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
2093 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
2095 return skb
->head
+ skb
->transport_header
;
2098 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
2100 skb
->transport_header
= skb
->data
- skb
->head
;
2103 static inline void skb_set_transport_header(struct sk_buff
*skb
,
2106 skb_reset_transport_header(skb
);
2107 skb
->transport_header
+= offset
;
2110 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
2112 return skb
->head
+ skb
->network_header
;
2115 static inline void skb_reset_network_header(struct sk_buff
*skb
)
2117 skb
->network_header
= skb
->data
- skb
->head
;
2120 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
2122 skb_reset_network_header(skb
);
2123 skb
->network_header
+= offset
;
2126 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
2128 return skb
->head
+ skb
->mac_header
;
2131 static inline int skb_mac_offset(const struct sk_buff
*skb
)
2133 return skb_mac_header(skb
) - skb
->data
;
2136 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
2138 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
2141 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
2143 skb
->mac_header
= skb
->data
- skb
->head
;
2146 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
2148 skb_reset_mac_header(skb
);
2149 skb
->mac_header
+= offset
;
2152 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
2154 skb
->mac_header
= skb
->network_header
;
2157 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
2158 const int offset_hint
)
2160 struct flow_keys keys
;
2162 if (skb_transport_header_was_set(skb
))
2164 else if (skb_flow_dissect_flow_keys(skb
, &keys
, 0))
2165 skb_set_transport_header(skb
, keys
.control
.thoff
);
2167 skb_set_transport_header(skb
, offset_hint
);
2170 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
2172 if (skb_mac_header_was_set(skb
)) {
2173 const unsigned char *old_mac
= skb_mac_header(skb
);
2175 skb_set_mac_header(skb
, -skb
->mac_len
);
2176 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
2180 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
2182 return skb
->csum_start
- skb_headroom(skb
);
2185 static inline unsigned char *skb_checksum_start(const struct sk_buff
*skb
)
2187 return skb
->head
+ skb
->csum_start
;
2190 static inline int skb_transport_offset(const struct sk_buff
*skb
)
2192 return skb_transport_header(skb
) - skb
->data
;
2195 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
2197 return skb
->transport_header
- skb
->network_header
;
2200 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
2202 return skb
->inner_transport_header
- skb
->inner_network_header
;
2205 static inline int skb_network_offset(const struct sk_buff
*skb
)
2207 return skb_network_header(skb
) - skb
->data
;
2210 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
2212 return skb_inner_network_header(skb
) - skb
->data
;
2215 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
2217 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
2221 * CPUs often take a performance hit when accessing unaligned memory
2222 * locations. The actual performance hit varies, it can be small if the
2223 * hardware handles it or large if we have to take an exception and fix it
2226 * Since an ethernet header is 14 bytes network drivers often end up with
2227 * the IP header at an unaligned offset. The IP header can be aligned by
2228 * shifting the start of the packet by 2 bytes. Drivers should do this
2231 * skb_reserve(skb, NET_IP_ALIGN);
2233 * The downside to this alignment of the IP header is that the DMA is now
2234 * unaligned. On some architectures the cost of an unaligned DMA is high
2235 * and this cost outweighs the gains made by aligning the IP header.
2237 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2240 #ifndef NET_IP_ALIGN
2241 #define NET_IP_ALIGN 2
2245 * The networking layer reserves some headroom in skb data (via
2246 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2247 * the header has to grow. In the default case, if the header has to grow
2248 * 32 bytes or less we avoid the reallocation.
2250 * Unfortunately this headroom changes the DMA alignment of the resulting
2251 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2252 * on some architectures. An architecture can override this value,
2253 * perhaps setting it to a cacheline in size (since that will maintain
2254 * cacheline alignment of the DMA). It must be a power of 2.
2256 * Various parts of the networking layer expect at least 32 bytes of
2257 * headroom, you should not reduce this.
2259 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2260 * to reduce average number of cache lines per packet.
2261 * get_rps_cpus() for example only access one 64 bytes aligned block :
2262 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2265 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2268 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2270 static inline void __skb_set_length(struct sk_buff
*skb
, unsigned int len
)
2272 if (unlikely(skb_is_nonlinear(skb
))) {
2277 skb_set_tail_pointer(skb
, len
);
2280 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2282 __skb_set_length(skb
, len
);
2285 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2287 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2290 return ___pskb_trim(skb
, len
);
2291 __skb_trim(skb
, len
);
2295 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2297 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2301 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2302 * @skb: buffer to alter
2305 * This is identical to pskb_trim except that the caller knows that
2306 * the skb is not cloned so we should never get an error due to out-
2309 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2311 int err
= pskb_trim(skb
, len
);
2315 static inline int __skb_grow(struct sk_buff
*skb
, unsigned int len
)
2317 unsigned int diff
= len
- skb
->len
;
2319 if (skb_tailroom(skb
) < diff
) {
2320 int ret
= pskb_expand_head(skb
, 0, diff
- skb_tailroom(skb
),
2325 __skb_set_length(skb
, len
);
2330 * skb_orphan - orphan a buffer
2331 * @skb: buffer to orphan
2333 * If a buffer currently has an owner then we call the owner's
2334 * destructor function and make the @skb unowned. The buffer continues
2335 * to exist but is no longer charged to its former owner.
2337 static inline void skb_orphan(struct sk_buff
*skb
)
2339 if (skb
->destructor
) {
2340 skb
->destructor(skb
);
2341 skb
->destructor
= NULL
;
2349 * skb_orphan_frags - orphan the frags contained in a buffer
2350 * @skb: buffer to orphan frags from
2351 * @gfp_mask: allocation mask for replacement pages
2353 * For each frag in the SKB which needs a destructor (i.e. has an
2354 * owner) create a copy of that frag and release the original
2355 * page by calling the destructor.
2357 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2359 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
2361 return skb_copy_ubufs(skb
, gfp_mask
);
2365 * __skb_queue_purge - empty a list
2366 * @list: list to empty
2368 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2369 * the list and one reference dropped. This function does not take the
2370 * list lock and the caller must hold the relevant locks to use it.
2372 void skb_queue_purge(struct sk_buff_head
*list
);
2373 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2375 struct sk_buff
*skb
;
2376 while ((skb
= __skb_dequeue(list
)) != NULL
)
2380 void skb_rbtree_purge(struct rb_root
*root
);
2382 void *netdev_alloc_frag(unsigned int fragsz
);
2384 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2388 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2389 * @dev: network device to receive on
2390 * @length: length to allocate
2392 * Allocate a new &sk_buff and assign it a usage count of one. The
2393 * buffer has unspecified headroom built in. Users should allocate
2394 * the headroom they think they need without accounting for the
2395 * built in space. The built in space is used for optimisations.
2397 * %NULL is returned if there is no free memory. Although this function
2398 * allocates memory it can be called from an interrupt.
2400 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2401 unsigned int length
)
2403 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2406 /* legacy helper around __netdev_alloc_skb() */
2407 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2410 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2413 /* legacy helper around netdev_alloc_skb() */
2414 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2416 return netdev_alloc_skb(NULL
, length
);
2420 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2421 unsigned int length
, gfp_t gfp
)
2423 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2425 if (NET_IP_ALIGN
&& skb
)
2426 skb_reserve(skb
, NET_IP_ALIGN
);
2430 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2431 unsigned int length
)
2433 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2436 static inline void skb_free_frag(void *addr
)
2438 page_frag_free(addr
);
2441 void *napi_alloc_frag(unsigned int fragsz
);
2442 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2443 unsigned int length
, gfp_t gfp_mask
);
2444 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2445 unsigned int length
)
2447 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2449 void napi_consume_skb(struct sk_buff
*skb
, int budget
);
2451 void __kfree_skb_flush(void);
2452 void __kfree_skb_defer(struct sk_buff
*skb
);
2455 * __dev_alloc_pages - allocate page for network Rx
2456 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2457 * @order: size of the allocation
2459 * Allocate a new page.
2461 * %NULL is returned if there is no free memory.
2463 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2466 /* This piece of code contains several assumptions.
2467 * 1. This is for device Rx, therefor a cold page is preferred.
2468 * 2. The expectation is the user wants a compound page.
2469 * 3. If requesting a order 0 page it will not be compound
2470 * due to the check to see if order has a value in prep_new_page
2471 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2472 * code in gfp_to_alloc_flags that should be enforcing this.
2474 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2476 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2479 static inline struct page
*dev_alloc_pages(unsigned int order
)
2481 return __dev_alloc_pages(GFP_ATOMIC
| __GFP_NOWARN
, order
);
2485 * __dev_alloc_page - allocate a page for network Rx
2486 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2488 * Allocate a new page.
2490 * %NULL is returned if there is no free memory.
2492 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2494 return __dev_alloc_pages(gfp_mask
, 0);
2497 static inline struct page
*dev_alloc_page(void)
2499 return dev_alloc_pages(0);
2503 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2504 * @page: The page that was allocated from skb_alloc_page
2505 * @skb: The skb that may need pfmemalloc set
2507 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2508 struct sk_buff
*skb
)
2510 if (page_is_pfmemalloc(page
))
2511 skb
->pfmemalloc
= true;
2515 * skb_frag_page - retrieve the page referred to by a paged fragment
2516 * @frag: the paged fragment
2518 * Returns the &struct page associated with @frag.
2520 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2522 return frag
->page
.p
;
2526 * __skb_frag_ref - take an addition reference on a paged fragment.
2527 * @frag: the paged fragment
2529 * Takes an additional reference on the paged fragment @frag.
2531 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2533 get_page(skb_frag_page(frag
));
2537 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2539 * @f: the fragment offset.
2541 * Takes an additional reference on the @f'th paged fragment of @skb.
2543 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2545 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2549 * __skb_frag_unref - release a reference on a paged fragment.
2550 * @frag: the paged fragment
2552 * Releases a reference on the paged fragment @frag.
2554 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2556 put_page(skb_frag_page(frag
));
2560 * skb_frag_unref - release a reference on a paged fragment of an skb.
2562 * @f: the fragment offset
2564 * Releases a reference on the @f'th paged fragment of @skb.
2566 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2568 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2572 * skb_frag_address - gets the address of the data contained in a paged fragment
2573 * @frag: the paged fragment buffer
2575 * Returns the address of the data within @frag. The page must already
2578 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2580 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2584 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2585 * @frag: the paged fragment buffer
2587 * Returns the address of the data within @frag. Checks that the page
2588 * is mapped and returns %NULL otherwise.
2590 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2592 void *ptr
= page_address(skb_frag_page(frag
));
2596 return ptr
+ frag
->page_offset
;
2600 * __skb_frag_set_page - sets the page contained in a paged fragment
2601 * @frag: the paged fragment
2602 * @page: the page to set
2604 * Sets the fragment @frag to contain @page.
2606 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2608 frag
->page
.p
= page
;
2612 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2614 * @f: the fragment offset
2615 * @page: the page to set
2617 * Sets the @f'th fragment of @skb to contain @page.
2619 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2622 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2625 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2628 * skb_frag_dma_map - maps a paged fragment via the DMA API
2629 * @dev: the device to map the fragment to
2630 * @frag: the paged fragment to map
2631 * @offset: the offset within the fragment (starting at the
2632 * fragment's own offset)
2633 * @size: the number of bytes to map
2634 * @dir: the direction of the mapping (%PCI_DMA_*)
2636 * Maps the page associated with @frag to @device.
2638 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2639 const skb_frag_t
*frag
,
2640 size_t offset
, size_t size
,
2641 enum dma_data_direction dir
)
2643 return dma_map_page(dev
, skb_frag_page(frag
),
2644 frag
->page_offset
+ offset
, size
, dir
);
2647 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2650 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2654 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2657 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2662 * skb_clone_writable - is the header of a clone writable
2663 * @skb: buffer to check
2664 * @len: length up to which to write
2666 * Returns true if modifying the header part of the cloned buffer
2667 * does not requires the data to be copied.
2669 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2671 return !skb_header_cloned(skb
) &&
2672 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2675 static inline int skb_try_make_writable(struct sk_buff
*skb
,
2676 unsigned int write_len
)
2678 return skb_cloned(skb
) && !skb_clone_writable(skb
, write_len
) &&
2679 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
2682 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2687 if (headroom
> skb_headroom(skb
))
2688 delta
= headroom
- skb_headroom(skb
);
2690 if (delta
|| cloned
)
2691 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2697 * skb_cow - copy header of skb when it is required
2698 * @skb: buffer to cow
2699 * @headroom: needed headroom
2701 * If the skb passed lacks sufficient headroom or its data part
2702 * is shared, data is reallocated. If reallocation fails, an error
2703 * is returned and original skb is not changed.
2705 * The result is skb with writable area skb->head...skb->tail
2706 * and at least @headroom of space at head.
2708 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2710 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2714 * skb_cow_head - skb_cow but only making the head writable
2715 * @skb: buffer to cow
2716 * @headroom: needed headroom
2718 * This function is identical to skb_cow except that we replace the
2719 * skb_cloned check by skb_header_cloned. It should be used when
2720 * you only need to push on some header and do not need to modify
2723 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2725 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2729 * skb_padto - pad an skbuff up to a minimal size
2730 * @skb: buffer to pad
2731 * @len: minimal length
2733 * Pads up a buffer to ensure the trailing bytes exist and are
2734 * blanked. If the buffer already contains sufficient data it
2735 * is untouched. Otherwise it is extended. Returns zero on
2736 * success. The skb is freed on error.
2738 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2740 unsigned int size
= skb
->len
;
2741 if (likely(size
>= len
))
2743 return skb_pad(skb
, len
- size
);
2747 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2748 * @skb: buffer to pad
2749 * @len: minimal length
2751 * Pads up a buffer to ensure the trailing bytes exist and are
2752 * blanked. If the buffer already contains sufficient data it
2753 * is untouched. Otherwise it is extended. Returns zero on
2754 * success. The skb is freed on error.
2756 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2758 unsigned int size
= skb
->len
;
2760 if (unlikely(size
< len
)) {
2762 if (skb_pad(skb
, len
))
2764 __skb_put(skb
, len
);
2769 static inline int skb_add_data(struct sk_buff
*skb
,
2770 struct iov_iter
*from
, int copy
)
2772 const int off
= skb
->len
;
2774 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2776 if (csum_and_copy_from_iter_full(skb_put(skb
, copy
), copy
,
2778 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2781 } else if (copy_from_iter_full(skb_put(skb
, copy
), copy
, from
))
2784 __skb_trim(skb
, off
);
2788 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2789 const struct page
*page
, int off
)
2792 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2794 return page
== skb_frag_page(frag
) &&
2795 off
== frag
->page_offset
+ skb_frag_size(frag
);
2800 static inline int __skb_linearize(struct sk_buff
*skb
)
2802 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2806 * skb_linearize - convert paged skb to linear one
2807 * @skb: buffer to linarize
2809 * If there is no free memory -ENOMEM is returned, otherwise zero
2810 * is returned and the old skb data released.
2812 static inline int skb_linearize(struct sk_buff
*skb
)
2814 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2818 * skb_has_shared_frag - can any frag be overwritten
2819 * @skb: buffer to test
2821 * Return true if the skb has at least one frag that might be modified
2822 * by an external entity (as in vmsplice()/sendfile())
2824 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2826 return skb_is_nonlinear(skb
) &&
2827 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2831 * skb_linearize_cow - make sure skb is linear and writable
2832 * @skb: buffer to process
2834 * If there is no free memory -ENOMEM is returned, otherwise zero
2835 * is returned and the old skb data released.
2837 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2839 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2840 __skb_linearize(skb
) : 0;
2843 static __always_inline
void
2844 __skb_postpull_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
2847 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2848 skb
->csum
= csum_block_sub(skb
->csum
,
2849 csum_partial(start
, len
, 0), off
);
2850 else if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
2851 skb_checksum_start_offset(skb
) < 0)
2852 skb
->ip_summed
= CHECKSUM_NONE
;
2856 * skb_postpull_rcsum - update checksum for received skb after pull
2857 * @skb: buffer to update
2858 * @start: start of data before pull
2859 * @len: length of data pulled
2861 * After doing a pull on a received packet, you need to call this to
2862 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2863 * CHECKSUM_NONE so that it can be recomputed from scratch.
2865 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2866 const void *start
, unsigned int len
)
2868 __skb_postpull_rcsum(skb
, start
, len
, 0);
2871 static __always_inline
void
2872 __skb_postpush_rcsum(struct sk_buff
*skb
, const void *start
, unsigned int len
,
2875 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2876 skb
->csum
= csum_block_add(skb
->csum
,
2877 csum_partial(start
, len
, 0), off
);
2881 * skb_postpush_rcsum - update checksum for received skb after push
2882 * @skb: buffer to update
2883 * @start: start of data after push
2884 * @len: length of data pushed
2886 * After doing a push on a received packet, you need to call this to
2887 * update the CHECKSUM_COMPLETE checksum.
2889 static inline void skb_postpush_rcsum(struct sk_buff
*skb
,
2890 const void *start
, unsigned int len
)
2892 __skb_postpush_rcsum(skb
, start
, len
, 0);
2895 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2898 * skb_push_rcsum - push skb and update receive checksum
2899 * @skb: buffer to update
2900 * @len: length of data pulled
2902 * This function performs an skb_push on the packet and updates
2903 * the CHECKSUM_COMPLETE checksum. It should be used on
2904 * receive path processing instead of skb_push unless you know
2905 * that the checksum difference is zero (e.g., a valid IP header)
2906 * or you are setting ip_summed to CHECKSUM_NONE.
2908 static inline unsigned char *skb_push_rcsum(struct sk_buff
*skb
,
2912 skb_postpush_rcsum(skb
, skb
->data
, len
);
2917 * pskb_trim_rcsum - trim received skb and update checksum
2918 * @skb: buffer to trim
2921 * This is exactly the same as pskb_trim except that it ensures the
2922 * checksum of received packets are still valid after the operation.
2925 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2927 if (likely(len
>= skb
->len
))
2929 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2930 skb
->ip_summed
= CHECKSUM_NONE
;
2931 return __pskb_trim(skb
, len
);
2934 static inline int __skb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2936 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2937 skb
->ip_summed
= CHECKSUM_NONE
;
2938 __skb_trim(skb
, len
);
2942 static inline int __skb_grow_rcsum(struct sk_buff
*skb
, unsigned int len
)
2944 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2945 skb
->ip_summed
= CHECKSUM_NONE
;
2946 return __skb_grow(skb
, len
);
2949 #define skb_queue_walk(queue, skb) \
2950 for (skb = (queue)->next; \
2951 skb != (struct sk_buff *)(queue); \
2954 #define skb_queue_walk_safe(queue, skb, tmp) \
2955 for (skb = (queue)->next, tmp = skb->next; \
2956 skb != (struct sk_buff *)(queue); \
2957 skb = tmp, tmp = skb->next)
2959 #define skb_queue_walk_from(queue, skb) \
2960 for (; skb != (struct sk_buff *)(queue); \
2963 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2964 for (tmp = skb->next; \
2965 skb != (struct sk_buff *)(queue); \
2966 skb = tmp, tmp = skb->next)
2968 #define skb_queue_reverse_walk(queue, skb) \
2969 for (skb = (queue)->prev; \
2970 skb != (struct sk_buff *)(queue); \
2973 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2974 for (skb = (queue)->prev, tmp = skb->prev; \
2975 skb != (struct sk_buff *)(queue); \
2976 skb = tmp, tmp = skb->prev)
2978 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2979 for (tmp = skb->prev; \
2980 skb != (struct sk_buff *)(queue); \
2981 skb = tmp, tmp = skb->prev)
2983 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2985 return skb_shinfo(skb
)->frag_list
!= NULL
;
2988 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2990 skb_shinfo(skb
)->frag_list
= NULL
;
2993 #define skb_walk_frags(skb, iter) \
2994 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2997 int __skb_wait_for_more_packets(struct sock
*sk
, int *err
, long *timeo_p
,
2998 const struct sk_buff
*skb
);
2999 struct sk_buff
*__skb_try_recv_from_queue(struct sock
*sk
,
3000 struct sk_buff_head
*queue
,
3002 void (*destructor
)(struct sock
*sk
,
3003 struct sk_buff
*skb
),
3004 int *peeked
, int *off
, int *err
,
3005 struct sk_buff
**last
);
3006 struct sk_buff
*__skb_try_recv_datagram(struct sock
*sk
, unsigned flags
,
3007 void (*destructor
)(struct sock
*sk
,
3008 struct sk_buff
*skb
),
3009 int *peeked
, int *off
, int *err
,
3010 struct sk_buff
**last
);
3011 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
3012 void (*destructor
)(struct sock
*sk
,
3013 struct sk_buff
*skb
),
3014 int *peeked
, int *off
, int *err
);
3015 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
3017 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
3018 struct poll_table_struct
*wait
);
3019 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
3020 struct iov_iter
*to
, int size
);
3021 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
3022 struct msghdr
*msg
, int size
)
3024 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
3026 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
3027 struct msghdr
*msg
);
3028 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
3029 struct iov_iter
*from
, int len
);
3030 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
3031 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
3032 void __skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
, int len
);
3033 static inline void skb_free_datagram_locked(struct sock
*sk
,
3034 struct sk_buff
*skb
)
3036 __skb_free_datagram_locked(sk
, skb
, 0);
3038 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
3039 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
3040 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
3041 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
3042 int len
, __wsum csum
);
3043 int skb_splice_bits(struct sk_buff
*skb
, struct sock
*sk
, unsigned int offset
,
3044 struct pipe_inode_info
*pipe
, unsigned int len
,
3045 unsigned int flags
);
3046 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
3047 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
3048 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
3050 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
3051 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
3052 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
3053 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
3054 bool skb_gso_validate_mtu(const struct sk_buff
*skb
, unsigned int mtu
);
3055 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
3056 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
3057 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
3058 int __skb_vlan_pop(struct sk_buff
*skb
, u16
*vlan_tci
);
3059 int skb_vlan_pop(struct sk_buff
*skb
);
3060 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
3061 struct sk_buff
*pskb_extract(struct sk_buff
*skb
, int off
, int to_copy
,
3064 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
3066 return copy_from_iter_full(data
, len
, &msg
->msg_iter
) ? 0 : -EFAULT
;
3069 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
3071 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3074 struct skb_checksum_ops
{
3075 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
3076 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
3079 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3080 __wsum csum
, const struct skb_checksum_ops
*ops
);
3081 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3084 static inline void * __must_check
3085 __skb_header_pointer(const struct sk_buff
*skb
, int offset
,
3086 int len
, void *data
, int hlen
, void *buffer
)
3088 if (hlen
- offset
>= len
)
3089 return data
+ offset
;
3092 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
3098 static inline void * __must_check
3099 skb_header_pointer(const struct sk_buff
*skb
, int offset
, int len
, void *buffer
)
3101 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
3102 skb_headlen(skb
), buffer
);
3106 * skb_needs_linearize - check if we need to linearize a given skb
3107 * depending on the given device features.
3108 * @skb: socket buffer to check
3109 * @features: net device features
3111 * Returns true if either:
3112 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3113 * 2. skb is fragmented and the device does not support SG.
3115 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
3116 netdev_features_t features
)
3118 return skb_is_nonlinear(skb
) &&
3119 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
3120 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
3123 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
3125 const unsigned int len
)
3127 memcpy(to
, skb
->data
, len
);
3130 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
3131 const int offset
, void *to
,
3132 const unsigned int len
)
3134 memcpy(to
, skb
->data
+ offset
, len
);
3137 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
3139 const unsigned int len
)
3141 memcpy(skb
->data
, from
, len
);
3144 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
3147 const unsigned int len
)
3149 memcpy(skb
->data
+ offset
, from
, len
);
3152 void skb_init(void);
3154 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
3160 * skb_get_timestamp - get timestamp from a skb
3161 * @skb: skb to get stamp from
3162 * @stamp: pointer to struct timeval to store stamp in
3164 * Timestamps are stored in the skb as offsets to a base timestamp.
3165 * This function converts the offset back to a struct timeval and stores
3168 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
3169 struct timeval
*stamp
)
3171 *stamp
= ktime_to_timeval(skb
->tstamp
);
3174 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
3175 struct timespec
*stamp
)
3177 *stamp
= ktime_to_timespec(skb
->tstamp
);
3180 static inline void __net_timestamp(struct sk_buff
*skb
)
3182 skb
->tstamp
= ktime_get_real();
3185 static inline ktime_t
net_timedelta(ktime_t t
)
3187 return ktime_sub(ktime_get_real(), t
);
3190 static inline ktime_t
net_invalid_timestamp(void)
3195 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
3197 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3199 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
3200 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
3202 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3204 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
3208 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
3213 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3216 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3218 * PHY drivers may accept clones of transmitted packets for
3219 * timestamping via their phy_driver.txtstamp method. These drivers
3220 * must call this function to return the skb back to the stack with a
3223 * @skb: clone of the the original outgoing packet
3224 * @hwtstamps: hardware time stamps
3227 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
3228 struct skb_shared_hwtstamps
*hwtstamps
);
3230 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
3231 struct skb_shared_hwtstamps
*hwtstamps
,
3232 struct sock
*sk
, int tstype
);
3235 * skb_tstamp_tx - queue clone of skb with send time stamps
3236 * @orig_skb: the original outgoing packet
3237 * @hwtstamps: hardware time stamps, may be NULL if not available
3239 * If the skb has a socket associated, then this function clones the
3240 * skb (thus sharing the actual data and optional structures), stores
3241 * the optional hardware time stamping information (if non NULL) or
3242 * generates a software time stamp (otherwise), then queues the clone
3243 * to the error queue of the socket. Errors are silently ignored.
3245 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
3246 struct skb_shared_hwtstamps
*hwtstamps
);
3248 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
3250 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
3251 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
3252 skb_tstamp_tx(skb
, NULL
);
3256 * skb_tx_timestamp() - Driver hook for transmit timestamping
3258 * Ethernet MAC Drivers should call this function in their hard_xmit()
3259 * function immediately before giving the sk_buff to the MAC hardware.
3261 * Specifically, one should make absolutely sure that this function is
3262 * called before TX completion of this packet can trigger. Otherwise
3263 * the packet could potentially already be freed.
3265 * @skb: A socket buffer.
3267 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
3269 skb_clone_tx_timestamp(skb
);
3270 sw_tx_timestamp(skb
);
3274 * skb_complete_wifi_ack - deliver skb with wifi status
3276 * @skb: the original outgoing packet
3277 * @acked: ack status
3280 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
3282 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
3283 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
3285 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
3287 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
3289 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3290 skb_checksum_start_offset(skb
) >= 0));
3294 * skb_checksum_complete - Calculate checksum of an entire packet
3295 * @skb: packet to process
3297 * This function calculates the checksum over the entire packet plus
3298 * the value of skb->csum. The latter can be used to supply the
3299 * checksum of a pseudo header as used by TCP/UDP. It returns the
3302 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3303 * this function can be used to verify that checksum on received
3304 * packets. In that case the function should return zero if the
3305 * checksum is correct. In particular, this function will return zero
3306 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3307 * hardware has already verified the correctness of the checksum.
3309 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
3311 return skb_csum_unnecessary(skb
) ?
3312 0 : __skb_checksum_complete(skb
);
3315 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
3317 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3318 if (skb
->csum_level
== 0)
3319 skb
->ip_summed
= CHECKSUM_NONE
;
3325 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
3327 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3328 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
3330 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
3331 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
3332 skb
->csum_level
= 0;
3336 static inline void __skb_mark_checksum_bad(struct sk_buff
*skb
)
3338 /* Mark current checksum as bad (typically called from GRO
3339 * path). In the case that ip_summed is CHECKSUM_NONE
3340 * this must be the first checksum encountered in the packet.
3341 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
3342 * checksum after the last one validated. For UDP, a zero
3343 * checksum can not be marked as bad.
3346 if (skb
->ip_summed
== CHECKSUM_NONE
||
3347 skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
3351 /* Check if we need to perform checksum complete validation.
3353 * Returns true if checksum complete is needed, false otherwise
3354 * (either checksum is unnecessary or zero checksum is allowed).
3356 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3360 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3361 skb
->csum_valid
= 1;
3362 __skb_decr_checksum_unnecessary(skb
);
3369 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3372 #define CHECKSUM_BREAK 76
3374 /* Unset checksum-complete
3376 * Unset checksum complete can be done when packet is being modified
3377 * (uncompressed for instance) and checksum-complete value is
3380 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3382 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3383 skb
->ip_summed
= CHECKSUM_NONE
;
3386 /* Validate (init) checksum based on checksum complete.
3389 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3390 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3391 * checksum is stored in skb->csum for use in __skb_checksum_complete
3392 * non-zero: value of invalid checksum
3395 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3399 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3400 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3401 skb
->csum_valid
= 1;
3404 } else if (skb
->csum_bad
) {
3405 /* ip_summed == CHECKSUM_NONE in this case */
3406 return (__force __sum16
)1;
3411 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3414 csum
= __skb_checksum_complete(skb
);
3415 skb
->csum_valid
= !csum
;
3422 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3427 /* Perform checksum validate (init). Note that this is a macro since we only
3428 * want to calculate the pseudo header which is an input function if necessary.
3429 * First we try to validate without any computation (checksum unnecessary) and
3430 * then calculate based on checksum complete calling the function to compute
3434 * 0: checksum is validated or try to in skb_checksum_complete
3435 * non-zero: value of invalid checksum
3437 #define __skb_checksum_validate(skb, proto, complete, \
3438 zero_okay, check, compute_pseudo) \
3440 __sum16 __ret = 0; \
3441 skb->csum_valid = 0; \
3442 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3443 __ret = __skb_checksum_validate_complete(skb, \
3444 complete, compute_pseudo(skb, proto)); \
3448 #define skb_checksum_init(skb, proto, compute_pseudo) \
3449 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3451 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3452 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3454 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3455 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3457 #define skb_checksum_validate_zero_check(skb, proto, check, \
3459 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3461 #define skb_checksum_simple_validate(skb) \
3462 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3464 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3466 return (skb
->ip_summed
== CHECKSUM_NONE
&&
3467 skb
->csum_valid
&& !skb
->csum_bad
);
3470 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3471 __sum16 check
, __wsum pseudo
)
3473 skb
->csum
= ~pseudo
;
3474 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3477 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3479 if (__skb_checksum_convert_check(skb)) \
3480 __skb_checksum_convert(skb, check, \
3481 compute_pseudo(skb, proto)); \
3484 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3485 u16 start
, u16 offset
)
3487 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3488 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3489 skb
->csum_offset
= offset
- start
;
3492 /* Update skbuf and packet to reflect the remote checksum offload operation.
3493 * When called, ptr indicates the starting point for skb->csum when
3494 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3495 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3497 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3498 int start
, int offset
, bool nopartial
)
3503 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3507 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3508 __skb_checksum_complete(skb
);
3509 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3512 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3514 /* Adjust skb->csum since we changed the packet */
3515 skb
->csum
= csum_add(skb
->csum
, delta
);
3518 static inline struct nf_conntrack
*skb_nfct(const struct sk_buff
*skb
)
3520 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3521 return (void *)(skb
->_nfct
& SKB_NFCT_PTRMASK
);
3527 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3528 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3529 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3531 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3532 nf_conntrack_destroy(nfct
);
3534 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3537 atomic_inc(&nfct
->use
);
3540 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3541 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3543 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
3546 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3549 atomic_inc(&nf_bridge
->use
);
3551 #endif /* CONFIG_BRIDGE_NETFILTER */
3552 static inline void nf_reset(struct sk_buff
*skb
)
3554 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3555 nf_conntrack_put(skb_nfct(skb
));
3558 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3559 nf_bridge_put(skb
->nf_bridge
);
3560 skb
->nf_bridge
= NULL
;
3564 static inline void nf_reset_trace(struct sk_buff
*skb
)
3566 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3571 /* Note: This doesn't put any conntrack and bridge info in dst. */
3572 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3575 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3576 dst
->_nfct
= src
->_nfct
;
3577 nf_conntrack_get(skb_nfct(src
));
3579 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3580 dst
->nf_bridge
= src
->nf_bridge
;
3581 nf_bridge_get(src
->nf_bridge
);
3583 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3585 dst
->nf_trace
= src
->nf_trace
;
3589 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3591 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3592 nf_conntrack_put(skb_nfct(dst
));
3594 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3595 nf_bridge_put(dst
->nf_bridge
);
3597 __nf_copy(dst
, src
, true);
3600 #ifdef CONFIG_NETWORK_SECMARK
3601 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3603 to
->secmark
= from
->secmark
;
3606 static inline void skb_init_secmark(struct sk_buff
*skb
)
3611 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3614 static inline void skb_init_secmark(struct sk_buff
*skb
)
3618 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3620 return !skb
->destructor
&&
3621 #if IS_ENABLED(CONFIG_XFRM)
3625 !skb
->_skb_refdst
&&
3626 !skb_has_frag_list(skb
);
3629 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3631 skb
->queue_mapping
= queue_mapping
;
3634 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3636 return skb
->queue_mapping
;
3639 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3641 to
->queue_mapping
= from
->queue_mapping
;
3644 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3646 skb
->queue_mapping
= rx_queue
+ 1;
3649 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3651 return skb
->queue_mapping
- 1;
3654 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3656 return skb
->queue_mapping
!= 0;
3659 static inline void skb_set_dst_pending_confirm(struct sk_buff
*skb
, u32 val
)
3661 skb
->dst_pending_confirm
= val
;
3664 static inline bool skb_get_dst_pending_confirm(const struct sk_buff
*skb
)
3666 return skb
->dst_pending_confirm
!= 0;
3669 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3678 /* Keeps track of mac header offset relative to skb->head.
3679 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3680 * For non-tunnel skb it points to skb_mac_header() and for
3681 * tunnel skb it points to outer mac header.
3682 * Keeps track of level of encapsulation of network headers.
3693 #define SKB_SGO_CB_OFFSET 32
3694 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
3696 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3698 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3699 SKB_GSO_CB(inner_skb
)->mac_offset
;
3702 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3704 int new_headroom
, headroom
;
3707 headroom
= skb_headroom(skb
);
3708 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3712 new_headroom
= skb_headroom(skb
);
3713 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3717 static inline void gso_reset_checksum(struct sk_buff
*skb
, __wsum res
)
3719 /* Do not update partial checksums if remote checksum is enabled. */
3720 if (skb
->remcsum_offload
)
3723 SKB_GSO_CB(skb
)->csum
= res
;
3724 SKB_GSO_CB(skb
)->csum_start
= skb_checksum_start(skb
) - skb
->head
;
3727 /* Compute the checksum for a gso segment. First compute the checksum value
3728 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3729 * then add in skb->csum (checksum from csum_start to end of packet).
3730 * skb->csum and csum_start are then updated to reflect the checksum of the
3731 * resultant packet starting from the transport header-- the resultant checksum
3732 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3735 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3737 unsigned char *csum_start
= skb_transport_header(skb
);
3738 int plen
= (skb
->head
+ SKB_GSO_CB(skb
)->csum_start
) - csum_start
;
3739 __wsum partial
= SKB_GSO_CB(skb
)->csum
;
3741 SKB_GSO_CB(skb
)->csum
= res
;
3742 SKB_GSO_CB(skb
)->csum_start
= csum_start
- skb
->head
;
3744 return csum_fold(csum_partial(csum_start
, plen
, partial
));
3747 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3749 return skb_shinfo(skb
)->gso_size
;
3752 /* Note: Should be called only if skb_is_gso(skb) is true */
3753 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3755 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3758 static inline void skb_gso_reset(struct sk_buff
*skb
)
3760 skb_shinfo(skb
)->gso_size
= 0;
3761 skb_shinfo(skb
)->gso_segs
= 0;
3762 skb_shinfo(skb
)->gso_type
= 0;
3765 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3767 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3769 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3770 * wanted then gso_type will be set. */
3771 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3773 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3774 unlikely(shinfo
->gso_type
== 0)) {
3775 __skb_warn_lro_forwarding(skb
);
3781 static inline void skb_forward_csum(struct sk_buff
*skb
)
3783 /* Unfortunately we don't support this one. Any brave souls? */
3784 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3785 skb
->ip_summed
= CHECKSUM_NONE
;
3789 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3790 * @skb: skb to check
3792 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3793 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3794 * use this helper, to document places where we make this assertion.
3796 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3799 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3803 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3805 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3806 struct sk_buff
*skb_checksum_trimmed(struct sk_buff
*skb
,
3807 unsigned int transport_len
,
3808 __sum16(*skb_chkf
)(struct sk_buff
*skb
));
3811 * skb_head_is_locked - Determine if the skb->head is locked down
3812 * @skb: skb to check
3814 * The head on skbs build around a head frag can be removed if they are
3815 * not cloned. This function returns true if the skb head is locked down
3816 * due to either being allocated via kmalloc, or by being a clone with
3817 * multiple references to the head.
3819 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3821 return !skb
->head_frag
|| skb_cloned(skb
);
3825 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3829 * skb_gso_network_seglen is used to determine the real size of the
3830 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3832 * The MAC/L2 header is not accounted for.
3834 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3836 unsigned int hdr_len
= skb_transport_header(skb
) -
3837 skb_network_header(skb
);
3838 return hdr_len
+ skb_gso_transport_seglen(skb
);
3841 /* Local Checksum Offload.
3842 * Compute outer checksum based on the assumption that the
3843 * inner checksum will be offloaded later.
3844 * See Documentation/networking/checksum-offloads.txt for
3845 * explanation of how this works.
3846 * Fill in outer checksum adjustment (e.g. with sum of outer
3847 * pseudo-header) before calling.
3848 * Also ensure that inner checksum is in linear data area.
3850 static inline __wsum
lco_csum(struct sk_buff
*skb
)
3852 unsigned char *csum_start
= skb_checksum_start(skb
);
3853 unsigned char *l4_hdr
= skb_transport_header(skb
);
3856 /* Start with complement of inner checksum adjustment */
3857 partial
= ~csum_unfold(*(__force __sum16
*)(csum_start
+
3860 /* Add in checksum of our headers (incl. outer checksum
3861 * adjustment filled in by caller) and return result.
3863 return csum_partial(l4_hdr
, csum_start
- l4_hdr
, partial
);
3866 #endif /* __KERNEL__ */
3867 #endif /* _LINUX_SKBUFF_H */