2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
23 #include <linux/rbtree.h>
24 #include <linux/socket.h>
26 #include <linux/atomic.h>
27 #include <asm/types.h>
28 #include <linux/spinlock.h>
29 #include <linux/net.h>
30 #include <linux/textsearch.h>
31 #include <net/checksum.h>
32 #include <linux/rcupdate.h>
33 #include <linux/hrtimer.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/netdev_features.h>
36 #include <linux/sched.h>
37 #include <net/flow_dissector.h>
38 #include <linux/splice.h>
39 #include <linux/in6.h>
42 /* The interface for checksum offload between the stack and networking drivers
45 * A. IP checksum related features
47 * Drivers advertise checksum offload capabilities in the features of a device.
48 * From the stack's point of view these are capabilities offered by the driver,
49 * a driver typically only advertises features that it is capable of offloading
52 * The checksum related features are:
54 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
55 * IP (one's complement) checksum for any combination
56 * of protocols or protocol layering. The checksum is
57 * computed and set in a packet per the CHECKSUM_PARTIAL
58 * interface (see below).
60 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
61 * TCP or UDP packets over IPv4. These are specifically
62 * unencapsulated packets of the form IPv4|TCP or
63 * IPv4|UDP where the Protocol field in the IPv4 header
64 * is TCP or UDP. The IPv4 header may contain IP options
65 * This feature cannot be set in features for a device
66 * with NETIF_F_HW_CSUM also set. This feature is being
67 * DEPRECATED (see below).
69 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
70 * TCP or UDP packets over IPv6. These are specifically
71 * unencapsulated packets of the form IPv6|TCP or
72 * IPv4|UDP where the Next Header field in the IPv6
73 * header is either TCP or UDP. IPv6 extension headers
74 * are not supported with this feature. This feature
75 * cannot be set in features for a device with
76 * NETIF_F_HW_CSUM also set. This feature is being
77 * DEPRECATED (see below).
79 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
80 * This flag is used only used to disable the RX checksum
81 * feature for a device. The stack will accept receive
82 * checksum indication in packets received on a device
83 * regardless of whether NETIF_F_RXCSUM is set.
85 * B. Checksumming of received packets by device. Indication of checksum
86 * verification is in set skb->ip_summed. Possible values are:
90 * Device did not checksum this packet e.g. due to lack of capabilities.
91 * The packet contains full (though not verified) checksum in packet but
92 * not in skb->csum. Thus, skb->csum is undefined in this case.
94 * CHECKSUM_UNNECESSARY:
96 * The hardware you're dealing with doesn't calculate the full checksum
97 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
98 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
99 * if their checksums are okay. skb->csum is still undefined in this case
100 * though. A driver or device must never modify the checksum field in the
101 * packet even if checksum is verified.
103 * CHECKSUM_UNNECESSARY is applicable to following protocols:
104 * TCP: IPv6 and IPv4.
105 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
106 * zero UDP checksum for either IPv4 or IPv6, the networking stack
107 * may perform further validation in this case.
108 * GRE: only if the checksum is present in the header.
109 * SCTP: indicates the CRC in SCTP header has been validated.
111 * skb->csum_level indicates the number of consecutive checksums found in
112 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
113 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
114 * and a device is able to verify the checksums for UDP (possibly zero),
115 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
116 * two. If the device were only able to verify the UDP checksum and not
117 * GRE, either because it doesn't support GRE checksum of because GRE
118 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
119 * not considered in this case).
123 * This is the most generic way. The device supplied checksum of the _whole_
124 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
125 * hardware doesn't need to parse L3/L4 headers to implement this.
127 * Note: Even if device supports only some protocols, but is able to produce
128 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
132 * A checksum is set up to be offloaded to a device as described in the
133 * output description for CHECKSUM_PARTIAL. This may occur on a packet
134 * received directly from another Linux OS, e.g., a virtualized Linux kernel
135 * on the same host, or it may be set in the input path in GRO or remote
136 * checksum offload. For the purposes of checksum verification, the checksum
137 * referred to by skb->csum_start + skb->csum_offset and any preceding
138 * checksums in the packet are considered verified. Any checksums in the
139 * packet that are after the checksum being offloaded are not considered to
142 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
143 * in the skb->ip_summed for a packet. Values are:
147 * The driver is required to checksum the packet as seen by hard_start_xmit()
148 * from skb->csum_start up to the end, and to record/write the checksum at
149 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
150 * csum_start and csum_offset values are valid values given the length and
151 * offset of the packet, however they should not attempt to validate that the
152 * checksum refers to a legitimate transport layer checksum-- it is the
153 * purview of the stack to validate that csum_start and csum_offset are set
156 * When the stack requests checksum offload for a packet, the driver MUST
157 * ensure that the checksum is set correctly. A driver can either offload the
158 * checksum calculation to the device, or call skb_checksum_help (in the case
159 * that the device does not support offload for a particular checksum).
161 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
162 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
163 * checksum offload capability. If a device has limited checksum capabilities
164 * (for instance can only perform NETIF_F_IP_CSUM or NETIF_F_IPV6_CSUM as
165 * described above) a helper function can be called to resolve
166 * CHECKSUM_PARTIAL. The helper functions are skb_csum_off_chk*. The helper
167 * function takes a spec argument that describes the protocol layer that is
168 * supported for checksum offload and can be called for each packet. If a
169 * packet does not match the specification for offload, skb_checksum_help
170 * is called to resolve the checksum.
174 * The skb was already checksummed by the protocol, or a checksum is not
177 * CHECKSUM_UNNECESSARY:
179 * This has the same meaning on as CHECKSUM_NONE for checksum offload on
183 * Not used in checksum output. If a driver observes a packet with this value
184 * set in skbuff, if should treat as CHECKSUM_NONE being set.
186 * D. Non-IP checksum (CRC) offloads
188 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
189 * offloading the SCTP CRC in a packet. To perform this offload the stack
190 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
191 * accordingly. Note the there is no indication in the skbuff that the
192 * CHECKSUM_PARTIAL refers to an SCTP checksum, a driver that supports
193 * both IP checksum offload and SCTP CRC offload must verify which offload
194 * is configured for a packet presumably by inspecting packet headers.
196 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
197 * offloading the FCOE CRC in a packet. To perform this offload the stack
198 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
199 * accordingly. Note the there is no indication in the skbuff that the
200 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
201 * both IP checksum offload and FCOE CRC offload must verify which offload
202 * is configured for a packet presumably by inspecting packet headers.
204 * E. Checksumming on output with GSO.
206 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
207 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
208 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
209 * part of the GSO operation is implied. If a checksum is being offloaded
210 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
211 * are set to refer to the outermost checksum being offload (two offloaded
212 * checksums are possible with UDP encapsulation).
215 /* Don't change this without changing skb_csum_unnecessary! */
216 #define CHECKSUM_NONE 0
217 #define CHECKSUM_UNNECESSARY 1
218 #define CHECKSUM_COMPLETE 2
219 #define CHECKSUM_PARTIAL 3
221 /* Maximum value in skb->csum_level */
222 #define SKB_MAX_CSUM_LEVEL 3
224 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
225 #define SKB_WITH_OVERHEAD(X) \
226 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
227 #define SKB_MAX_ORDER(X, ORDER) \
228 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
229 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
230 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
232 /* return minimum truesize of one skb containing X bytes of data */
233 #define SKB_TRUESIZE(X) ((X) + \
234 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
235 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
239 struct pipe_inode_info
;
243 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
244 struct nf_conntrack
{
249 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
250 struct nf_bridge_info
{
253 BRNF_PROTO_UNCHANGED
,
261 struct net_device
*physindev
;
263 /* always valid & non-NULL from FORWARD on, for physdev match */
264 struct net_device
*physoutdev
;
266 /* prerouting: detect dnat in orig/reply direction */
268 struct in6_addr ipv6_daddr
;
270 /* after prerouting + nat detected: store original source
271 * mac since neigh resolution overwrites it, only used while
272 * skb is out in neigh layer.
274 char neigh_header
[8];
279 struct sk_buff_head
{
280 /* These two members must be first. */
281 struct sk_buff
*next
;
282 struct sk_buff
*prev
;
290 /* To allow 64K frame to be packed as single skb without frag_list we
291 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
292 * buffers which do not start on a page boundary.
294 * Since GRO uses frags we allocate at least 16 regardless of page
297 #if (65536/PAGE_SIZE + 1) < 16
298 #define MAX_SKB_FRAGS 16UL
300 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
302 extern int sysctl_max_skb_frags
;
304 typedef struct skb_frag_struct skb_frag_t
;
306 struct skb_frag_struct
{
310 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
319 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
324 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
329 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
334 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
339 #define HAVE_HW_TIME_STAMP
342 * struct skb_shared_hwtstamps - hardware time stamps
343 * @hwtstamp: hardware time stamp transformed into duration
344 * since arbitrary point in time
346 * Software time stamps generated by ktime_get_real() are stored in
349 * hwtstamps can only be compared against other hwtstamps from
352 * This structure is attached to packets as part of the
353 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
355 struct skb_shared_hwtstamps
{
359 /* Definitions for tx_flags in struct skb_shared_info */
361 /* generate hardware time stamp */
362 SKBTX_HW_TSTAMP
= 1 << 0,
364 /* generate software time stamp when queueing packet to NIC */
365 SKBTX_SW_TSTAMP
= 1 << 1,
367 /* device driver is going to provide hardware time stamp */
368 SKBTX_IN_PROGRESS
= 1 << 2,
370 /* device driver supports TX zero-copy buffers */
371 SKBTX_DEV_ZEROCOPY
= 1 << 3,
373 /* generate wifi status information (where possible) */
374 SKBTX_WIFI_STATUS
= 1 << 4,
376 /* This indicates at least one fragment might be overwritten
377 * (as in vmsplice(), sendfile() ...)
378 * If we need to compute a TX checksum, we'll need to copy
379 * all frags to avoid possible bad checksum
381 SKBTX_SHARED_FRAG
= 1 << 5,
383 /* generate software time stamp when entering packet scheduling */
384 SKBTX_SCHED_TSTAMP
= 1 << 6,
387 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
389 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
392 * The callback notifies userspace to release buffers when skb DMA is done in
393 * lower device, the skb last reference should be 0 when calling this.
394 * The zerocopy_success argument is true if zero copy transmit occurred,
395 * false on data copy or out of memory error caused by data copy attempt.
396 * The ctx field is used to track device context.
397 * The desc field is used to track userspace buffer index.
400 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
405 /* This data is invariant across clones and lives at
406 * the end of the header data, ie. at skb->end.
408 struct skb_shared_info
{
409 unsigned char nr_frags
;
411 unsigned short gso_size
;
412 /* Warning: this field is not always filled in (UFO)! */
413 unsigned short gso_segs
;
414 unsigned short gso_type
;
415 struct sk_buff
*frag_list
;
416 struct skb_shared_hwtstamps hwtstamps
;
421 * Warning : all fields before dataref are cleared in __alloc_skb()
425 /* Intermediate layers must ensure that destructor_arg
426 * remains valid until skb destructor */
427 void * destructor_arg
;
429 /* must be last field, see pskb_expand_head() */
430 skb_frag_t frags
[MAX_SKB_FRAGS
];
433 /* We divide dataref into two halves. The higher 16 bits hold references
434 * to the payload part of skb->data. The lower 16 bits hold references to
435 * the entire skb->data. A clone of a headerless skb holds the length of
436 * the header in skb->hdr_len.
438 * All users must obey the rule that the skb->data reference count must be
439 * greater than or equal to the payload reference count.
441 * Holding a reference to the payload part means that the user does not
442 * care about modifications to the header part of skb->data.
444 #define SKB_DATAREF_SHIFT 16
445 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
449 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
450 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
451 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
455 SKB_GSO_TCPV4
= 1 << 0,
456 SKB_GSO_UDP
= 1 << 1,
458 /* This indicates the skb is from an untrusted source. */
459 SKB_GSO_DODGY
= 1 << 2,
461 /* This indicates the tcp segment has CWR set. */
462 SKB_GSO_TCP_ECN
= 1 << 3,
464 SKB_GSO_TCP_FIXEDID
= 1 << 4,
466 SKB_GSO_TCPV6
= 1 << 5,
468 SKB_GSO_FCOE
= 1 << 6,
470 SKB_GSO_GRE
= 1 << 7,
472 SKB_GSO_GRE_CSUM
= 1 << 8,
474 SKB_GSO_IPXIP4
= 1 << 9,
476 SKB_GSO_IPXIP6
= 1 << 10,
478 SKB_GSO_UDP_TUNNEL
= 1 << 11,
480 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 12,
482 SKB_GSO_PARTIAL
= 1 << 13,
484 SKB_GSO_TUNNEL_REMCSUM
= 1 << 14,
487 #if BITS_PER_LONG > 32
488 #define NET_SKBUFF_DATA_USES_OFFSET 1
491 #ifdef NET_SKBUFF_DATA_USES_OFFSET
492 typedef unsigned int sk_buff_data_t
;
494 typedef unsigned char *sk_buff_data_t
;
498 * struct skb_mstamp - multi resolution time stamps
499 * @stamp_us: timestamp in us resolution
500 * @stamp_jiffies: timestamp in jiffies
513 * skb_mstamp_get - get current timestamp
514 * @cl: place to store timestamps
516 static inline void skb_mstamp_get(struct skb_mstamp
*cl
)
518 u64 val
= local_clock();
520 do_div(val
, NSEC_PER_USEC
);
521 cl
->stamp_us
= (u32
)val
;
522 cl
->stamp_jiffies
= (u32
)jiffies
;
526 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
527 * @t1: pointer to newest sample
528 * @t0: pointer to oldest sample
530 static inline u32
skb_mstamp_us_delta(const struct skb_mstamp
*t1
,
531 const struct skb_mstamp
*t0
)
533 s32 delta_us
= t1
->stamp_us
- t0
->stamp_us
;
534 u32 delta_jiffies
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
536 /* If delta_us is negative, this might be because interval is too big,
537 * or local_clock() drift is too big : fallback using jiffies.
540 delta_jiffies
>= (INT_MAX
/ (USEC_PER_SEC
/ HZ
)))
542 delta_us
= jiffies_to_usecs(delta_jiffies
);
547 static inline bool skb_mstamp_after(const struct skb_mstamp
*t1
,
548 const struct skb_mstamp
*t0
)
550 s32 diff
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
553 diff
= t1
->stamp_us
- t0
->stamp_us
;
558 * struct sk_buff - socket buffer
559 * @next: Next buffer in list
560 * @prev: Previous buffer in list
561 * @tstamp: Time we arrived/left
562 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
563 * @sk: Socket we are owned by
564 * @dev: Device we arrived on/are leaving by
565 * @cb: Control buffer. Free for use by every layer. Put private vars here
566 * @_skb_refdst: destination entry (with norefcount bit)
567 * @sp: the security path, used for xfrm
568 * @len: Length of actual data
569 * @data_len: Data length
570 * @mac_len: Length of link layer header
571 * @hdr_len: writable header length of cloned skb
572 * @csum: Checksum (must include start/offset pair)
573 * @csum_start: Offset from skb->head where checksumming should start
574 * @csum_offset: Offset from csum_start where checksum should be stored
575 * @priority: Packet queueing priority
576 * @ignore_df: allow local fragmentation
577 * @cloned: Head may be cloned (check refcnt to be sure)
578 * @ip_summed: Driver fed us an IP checksum
579 * @nohdr: Payload reference only, must not modify header
580 * @nfctinfo: Relationship of this skb to the connection
581 * @pkt_type: Packet class
582 * @fclone: skbuff clone status
583 * @ipvs_property: skbuff is owned by ipvs
584 * @peeked: this packet has been seen already, so stats have been
585 * done for it, don't do them again
586 * @nf_trace: netfilter packet trace flag
587 * @protocol: Packet protocol from driver
588 * @destructor: Destruct function
589 * @nfct: Associated connection, if any
590 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
591 * @skb_iif: ifindex of device we arrived on
592 * @tc_index: Traffic control index
593 * @tc_verd: traffic control verdict
594 * @hash: the packet hash
595 * @queue_mapping: Queue mapping for multiqueue devices
596 * @xmit_more: More SKBs are pending for this queue
597 * @ndisc_nodetype: router type (from link layer)
598 * @ooo_okay: allow the mapping of a socket to a queue to be changed
599 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
601 * @sw_hash: indicates hash was computed in software stack
602 * @wifi_acked_valid: wifi_acked was set
603 * @wifi_acked: whether frame was acked on wifi or not
604 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
605 * @napi_id: id of the NAPI struct this skb came from
606 * @secmark: security marking
607 * @offload_fwd_mark: fwding offload mark
608 * @mark: Generic packet mark
609 * @vlan_proto: vlan encapsulation protocol
610 * @vlan_tci: vlan tag control information
611 * @inner_protocol: Protocol (encapsulation)
612 * @inner_transport_header: Inner transport layer header (encapsulation)
613 * @inner_network_header: Network layer header (encapsulation)
614 * @inner_mac_header: Link layer header (encapsulation)
615 * @transport_header: Transport layer header
616 * @network_header: Network layer header
617 * @mac_header: Link layer header
618 * @tail: Tail pointer
620 * @head: Head of buffer
621 * @data: Data head pointer
622 * @truesize: Buffer size
623 * @users: User count - see {datagram,tcp}.c
629 /* These two members must be first. */
630 struct sk_buff
*next
;
631 struct sk_buff
*prev
;
635 struct skb_mstamp skb_mstamp
;
638 struct rb_node rbnode
; /* used in netem & tcp stack */
641 struct net_device
*dev
;
644 * This is the control buffer. It is free to use for every
645 * layer. Please put your private variables there. If you
646 * want to keep them across layers you have to do a skb_clone()
647 * first. This is owned by whoever has the skb queued ATM.
649 char cb
[48] __aligned(8);
651 unsigned long _skb_refdst
;
652 void (*destructor
)(struct sk_buff
*skb
);
656 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
657 struct nf_conntrack
*nfct
;
659 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
660 struct nf_bridge_info
*nf_bridge
;
667 /* Following fields are _not_ copied in __copy_skb_header()
668 * Note that queue_mapping is here mostly to fill a hole.
670 kmemcheck_bitfield_begin(flags1
);
679 kmemcheck_bitfield_end(flags1
);
681 /* fields enclosed in headers_start/headers_end are copied
682 * using a single memcpy() in __copy_skb_header()
685 __u32 headers_start
[0];
688 /* if you move pkt_type around you also must adapt those constants */
689 #ifdef __BIG_ENDIAN_BITFIELD
690 #define PKT_TYPE_MAX (7 << 5)
692 #define PKT_TYPE_MAX 7
694 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
696 __u8 __pkt_type_offset
[0];
707 __u8 wifi_acked_valid
:1;
711 /* Indicates the inner headers are valid in the skbuff. */
712 __u8 encapsulation
:1;
713 __u8 encap_hdr_csum
:1;
715 __u8 csum_complete_sw
:1;
719 #ifdef CONFIG_IPV6_NDISC_NODETYPE
720 __u8 ndisc_nodetype
:2;
722 __u8 ipvs_property
:1;
723 __u8 inner_protocol_type
:1;
724 __u8 remcsum_offload
:1;
725 /* 3 or 5 bit hole */
727 #ifdef CONFIG_NET_SCHED
728 __u16 tc_index
; /* traffic control index */
729 #ifdef CONFIG_NET_CLS_ACT
730 __u16 tc_verd
; /* traffic control verdict */
746 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
748 unsigned int napi_id
;
749 unsigned int sender_cpu
;
753 #ifdef CONFIG_NETWORK_SECMARK
756 #ifdef CONFIG_NET_SWITCHDEV
757 __u32 offload_fwd_mark
;
763 __u32 reserved_tailroom
;
767 __be16 inner_protocol
;
771 __u16 inner_transport_header
;
772 __u16 inner_network_header
;
773 __u16 inner_mac_header
;
776 __u16 transport_header
;
777 __u16 network_header
;
781 __u32 headers_end
[0];
784 /* These elements must be at the end, see alloc_skb() for details. */
789 unsigned int truesize
;
795 * Handling routines are only of interest to the kernel
797 #include <linux/slab.h>
800 #define SKB_ALLOC_FCLONE 0x01
801 #define SKB_ALLOC_RX 0x02
802 #define SKB_ALLOC_NAPI 0x04
804 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
805 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
807 return unlikely(skb
->pfmemalloc
);
811 * skb might have a dst pointer attached, refcounted or not.
812 * _skb_refdst low order bit is set if refcount was _not_ taken
814 #define SKB_DST_NOREF 1UL
815 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
818 * skb_dst - returns skb dst_entry
821 * Returns skb dst_entry, regardless of reference taken or not.
823 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
825 /* If refdst was not refcounted, check we still are in a
826 * rcu_read_lock section
828 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
829 !rcu_read_lock_held() &&
830 !rcu_read_lock_bh_held());
831 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
835 * skb_dst_set - sets skb dst
839 * Sets skb dst, assuming a reference was taken on dst and should
840 * be released by skb_dst_drop()
842 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
844 skb
->_skb_refdst
= (unsigned long)dst
;
848 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
852 * Sets skb dst, assuming a reference was not taken on dst.
853 * If dst entry is cached, we do not take reference and dst_release
854 * will be avoided by refdst_drop. If dst entry is not cached, we take
855 * reference, so that last dst_release can destroy the dst immediately.
857 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
859 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
860 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
864 * skb_dst_is_noref - Test if skb dst isn't refcounted
867 static inline bool skb_dst_is_noref(const struct sk_buff
*skb
)
869 return (skb
->_skb_refdst
& SKB_DST_NOREF
) && skb_dst(skb
);
872 static inline struct rtable
*skb_rtable(const struct sk_buff
*skb
)
874 return (struct rtable
*)skb_dst(skb
);
877 void kfree_skb(struct sk_buff
*skb
);
878 void kfree_skb_list(struct sk_buff
*segs
);
879 void skb_tx_error(struct sk_buff
*skb
);
880 void consume_skb(struct sk_buff
*skb
);
881 void __kfree_skb(struct sk_buff
*skb
);
882 extern struct kmem_cache
*skbuff_head_cache
;
884 void kfree_skb_partial(struct sk_buff
*skb
, bool head_stolen
);
885 bool skb_try_coalesce(struct sk_buff
*to
, struct sk_buff
*from
,
886 bool *fragstolen
, int *delta_truesize
);
888 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t priority
, int flags
,
890 struct sk_buff
*__build_skb(void *data
, unsigned int frag_size
);
891 struct sk_buff
*build_skb(void *data
, unsigned int frag_size
);
892 static inline struct sk_buff
*alloc_skb(unsigned int size
,
895 return __alloc_skb(size
, priority
, 0, NUMA_NO_NODE
);
898 struct sk_buff
*alloc_skb_with_frags(unsigned long header_len
,
899 unsigned long data_len
,
904 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
905 struct sk_buff_fclones
{
914 * skb_fclone_busy - check if fclone is busy
917 * Returns true if skb is a fast clone, and its clone is not freed.
918 * Some drivers call skb_orphan() in their ndo_start_xmit(),
919 * so we also check that this didnt happen.
921 static inline bool skb_fclone_busy(const struct sock
*sk
,
922 const struct sk_buff
*skb
)
924 const struct sk_buff_fclones
*fclones
;
926 fclones
= container_of(skb
, struct sk_buff_fclones
, skb1
);
928 return skb
->fclone
== SKB_FCLONE_ORIG
&&
929 atomic_read(&fclones
->fclone_ref
) > 1 &&
930 fclones
->skb2
.sk
== sk
;
933 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
936 return __alloc_skb(size
, priority
, SKB_ALLOC_FCLONE
, NUMA_NO_NODE
);
939 struct sk_buff
*__alloc_skb_head(gfp_t priority
, int node
);
940 static inline struct sk_buff
*alloc_skb_head(gfp_t priority
)
942 return __alloc_skb_head(priority
, -1);
945 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
946 int skb_copy_ubufs(struct sk_buff
*skb
, gfp_t gfp_mask
);
947 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t priority
);
948 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t priority
);
949 struct sk_buff
*__pskb_copy_fclone(struct sk_buff
*skb
, int headroom
,
950 gfp_t gfp_mask
, bool fclone
);
951 static inline struct sk_buff
*__pskb_copy(struct sk_buff
*skb
, int headroom
,
954 return __pskb_copy_fclone(skb
, headroom
, gfp_mask
, false);
957 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
, gfp_t gfp_mask
);
958 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
959 unsigned int headroom
);
960 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
, int newheadroom
,
961 int newtailroom
, gfp_t priority
);
962 int skb_to_sgvec_nomark(struct sk_buff
*skb
, struct scatterlist
*sg
,
963 int offset
, int len
);
964 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
,
966 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
);
967 int skb_pad(struct sk_buff
*skb
, int pad
);
968 #define dev_kfree_skb(a) consume_skb(a)
970 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
971 int getfrag(void *from
, char *to
, int offset
,
972 int len
, int odd
, struct sk_buff
*skb
),
973 void *from
, int length
);
975 int skb_append_pagefrags(struct sk_buff
*skb
, struct page
*page
,
976 int offset
, size_t size
);
978 struct skb_seq_state
{
982 __u32 stepped_offset
;
983 struct sk_buff
*root_skb
;
984 struct sk_buff
*cur_skb
;
988 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
989 unsigned int to
, struct skb_seq_state
*st
);
990 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
991 struct skb_seq_state
*st
);
992 void skb_abort_seq_read(struct skb_seq_state
*st
);
994 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
995 unsigned int to
, struct ts_config
*config
);
998 * Packet hash types specify the type of hash in skb_set_hash.
1000 * Hash types refer to the protocol layer addresses which are used to
1001 * construct a packet's hash. The hashes are used to differentiate or identify
1002 * flows of the protocol layer for the hash type. Hash types are either
1003 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1005 * Properties of hashes:
1007 * 1) Two packets in different flows have different hash values
1008 * 2) Two packets in the same flow should have the same hash value
1010 * A hash at a higher layer is considered to be more specific. A driver should
1011 * set the most specific hash possible.
1013 * A driver cannot indicate a more specific hash than the layer at which a hash
1014 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1016 * A driver may indicate a hash level which is less specific than the
1017 * actual layer the hash was computed on. For instance, a hash computed
1018 * at L4 may be considered an L3 hash. This should only be done if the
1019 * driver can't unambiguously determine that the HW computed the hash at
1020 * the higher layer. Note that the "should" in the second property above
1023 enum pkt_hash_types
{
1024 PKT_HASH_TYPE_NONE
, /* Undefined type */
1025 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
1026 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
1027 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
1030 static inline void skb_clear_hash(struct sk_buff
*skb
)
1037 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
1040 skb_clear_hash(skb
);
1044 __skb_set_hash(struct sk_buff
*skb
, __u32 hash
, bool is_sw
, bool is_l4
)
1046 skb
->l4_hash
= is_l4
;
1047 skb
->sw_hash
= is_sw
;
1052 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
1054 /* Used by drivers to set hash from HW */
1055 __skb_set_hash(skb
, hash
, false, type
== PKT_HASH_TYPE_L4
);
1059 __skb_set_sw_hash(struct sk_buff
*skb
, __u32 hash
, bool is_l4
)
1061 __skb_set_hash(skb
, hash
, true, is_l4
);
1064 void __skb_get_hash(struct sk_buff
*skb
);
1065 u32
skb_get_poff(const struct sk_buff
*skb
);
1066 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
1067 const struct flow_keys
*keys
, int hlen
);
1068 __be32
__skb_flow_get_ports(const struct sk_buff
*skb
, int thoff
, u8 ip_proto
,
1069 void *data
, int hlen_proto
);
1071 static inline __be32
skb_flow_get_ports(const struct sk_buff
*skb
,
1072 int thoff
, u8 ip_proto
)
1074 return __skb_flow_get_ports(skb
, thoff
, ip_proto
, NULL
, 0);
1077 void skb_flow_dissector_init(struct flow_dissector
*flow_dissector
,
1078 const struct flow_dissector_key
*key
,
1079 unsigned int key_count
);
1081 bool __skb_flow_dissect(const struct sk_buff
*skb
,
1082 struct flow_dissector
*flow_dissector
,
1083 void *target_container
,
1084 void *data
, __be16 proto
, int nhoff
, int hlen
,
1085 unsigned int flags
);
1087 static inline bool skb_flow_dissect(const struct sk_buff
*skb
,
1088 struct flow_dissector
*flow_dissector
,
1089 void *target_container
, unsigned int flags
)
1091 return __skb_flow_dissect(skb
, flow_dissector
, target_container
,
1092 NULL
, 0, 0, 0, flags
);
1095 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff
*skb
,
1096 struct flow_keys
*flow
,
1099 memset(flow
, 0, sizeof(*flow
));
1100 return __skb_flow_dissect(skb
, &flow_keys_dissector
, flow
,
1101 NULL
, 0, 0, 0, flags
);
1104 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys
*flow
,
1105 void *data
, __be16 proto
,
1106 int nhoff
, int hlen
,
1109 memset(flow
, 0, sizeof(*flow
));
1110 return __skb_flow_dissect(NULL
, &flow_keys_buf_dissector
, flow
,
1111 data
, proto
, nhoff
, hlen
, flags
);
1114 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
1116 if (!skb
->l4_hash
&& !skb
->sw_hash
)
1117 __skb_get_hash(skb
);
1122 __u32
__skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
);
1124 static inline __u32
skb_get_hash_flowi6(struct sk_buff
*skb
, const struct flowi6
*fl6
)
1126 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1127 struct flow_keys keys
;
1128 __u32 hash
= __get_hash_from_flowi6(fl6
, &keys
);
1130 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1136 __u32
__skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl
);
1138 static inline __u32
skb_get_hash_flowi4(struct sk_buff
*skb
, const struct flowi4
*fl4
)
1140 if (!skb
->l4_hash
&& !skb
->sw_hash
) {
1141 struct flow_keys keys
;
1142 __u32 hash
= __get_hash_from_flowi4(fl4
, &keys
);
1144 __skb_set_sw_hash(skb
, hash
, flow_keys_have_l4(&keys
));
1150 __u32
skb_get_hash_perturb(const struct sk_buff
*skb
, u32 perturb
);
1152 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
1157 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
1159 to
->hash
= from
->hash
;
1160 to
->sw_hash
= from
->sw_hash
;
1161 to
->l4_hash
= from
->l4_hash
;
1164 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1165 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1167 return skb
->head
+ skb
->end
;
1170 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1175 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
1180 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
1182 return skb
->end
- skb
->head
;
1187 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1189 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
1191 return &skb_shinfo(skb
)->hwtstamps
;
1195 * skb_queue_empty - check if a queue is empty
1198 * Returns true if the queue is empty, false otherwise.
1200 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1202 return list
->next
== (const struct sk_buff
*) list
;
1206 * skb_queue_is_last - check if skb is the last entry in the queue
1210 * Returns true if @skb is the last buffer on the list.
1212 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1213 const struct sk_buff
*skb
)
1215 return skb
->next
== (const struct sk_buff
*) list
;
1219 * skb_queue_is_first - check if skb is the first entry in the queue
1223 * Returns true if @skb is the first buffer on the list.
1225 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1226 const struct sk_buff
*skb
)
1228 return skb
->prev
== (const struct sk_buff
*) list
;
1232 * skb_queue_next - return the next packet in the queue
1234 * @skb: current buffer
1236 * Return the next packet in @list after @skb. It is only valid to
1237 * call this if skb_queue_is_last() evaluates to false.
1239 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1240 const struct sk_buff
*skb
)
1242 /* This BUG_ON may seem severe, but if we just return then we
1243 * are going to dereference garbage.
1245 BUG_ON(skb_queue_is_last(list
, skb
));
1250 * skb_queue_prev - return the prev packet in the queue
1252 * @skb: current buffer
1254 * Return the prev packet in @list before @skb. It is only valid to
1255 * call this if skb_queue_is_first() evaluates to false.
1257 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1258 const struct sk_buff
*skb
)
1260 /* This BUG_ON may seem severe, but if we just return then we
1261 * are going to dereference garbage.
1263 BUG_ON(skb_queue_is_first(list
, skb
));
1268 * skb_get - reference buffer
1269 * @skb: buffer to reference
1271 * Makes another reference to a socket buffer and returns a pointer
1274 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1276 atomic_inc(&skb
->users
);
1281 * If users == 1, we are the only owner and are can avoid redundant
1286 * skb_cloned - is the buffer a clone
1287 * @skb: buffer to check
1289 * Returns true if the buffer was generated with skb_clone() and is
1290 * one of multiple shared copies of the buffer. Cloned buffers are
1291 * shared data so must not be written to under normal circumstances.
1293 static inline int skb_cloned(const struct sk_buff
*skb
)
1295 return skb
->cloned
&&
1296 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1299 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1301 might_sleep_if(gfpflags_allow_blocking(pri
));
1303 if (skb_cloned(skb
))
1304 return pskb_expand_head(skb
, 0, 0, pri
);
1310 * skb_header_cloned - is the header a clone
1311 * @skb: buffer to check
1313 * Returns true if modifying the header part of the buffer requires
1314 * the data to be copied.
1316 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1323 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1324 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1325 return dataref
!= 1;
1328 static inline int skb_header_unclone(struct sk_buff
*skb
, gfp_t pri
)
1330 might_sleep_if(gfpflags_allow_blocking(pri
));
1332 if (skb_header_cloned(skb
))
1333 return pskb_expand_head(skb
, 0, 0, pri
);
1339 * skb_header_release - release reference to header
1340 * @skb: buffer to operate on
1342 * Drop a reference to the header part of the buffer. This is done
1343 * by acquiring a payload reference. You must not read from the header
1344 * part of skb->data after this.
1345 * Note : Check if you can use __skb_header_release() instead.
1347 static inline void skb_header_release(struct sk_buff
*skb
)
1351 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1355 * __skb_header_release - release reference to header
1356 * @skb: buffer to operate on
1358 * Variant of skb_header_release() assuming skb is private to caller.
1359 * We can avoid one atomic operation.
1361 static inline void __skb_header_release(struct sk_buff
*skb
)
1364 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1369 * skb_shared - is the buffer shared
1370 * @skb: buffer to check
1372 * Returns true if more than one person has a reference to this
1375 static inline int skb_shared(const struct sk_buff
*skb
)
1377 return atomic_read(&skb
->users
) != 1;
1381 * skb_share_check - check if buffer is shared and if so clone it
1382 * @skb: buffer to check
1383 * @pri: priority for memory allocation
1385 * If the buffer is shared the buffer is cloned and the old copy
1386 * drops a reference. A new clone with a single reference is returned.
1387 * If the buffer is not shared the original buffer is returned. When
1388 * being called from interrupt status or with spinlocks held pri must
1391 * NULL is returned on a memory allocation failure.
1393 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1395 might_sleep_if(gfpflags_allow_blocking(pri
));
1396 if (skb_shared(skb
)) {
1397 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1409 * Copy shared buffers into a new sk_buff. We effectively do COW on
1410 * packets to handle cases where we have a local reader and forward
1411 * and a couple of other messy ones. The normal one is tcpdumping
1412 * a packet thats being forwarded.
1416 * skb_unshare - make a copy of a shared buffer
1417 * @skb: buffer to check
1418 * @pri: priority for memory allocation
1420 * If the socket buffer is a clone then this function creates a new
1421 * copy of the data, drops a reference count on the old copy and returns
1422 * the new copy with the reference count at 1. If the buffer is not a clone
1423 * the original buffer is returned. When called with a spinlock held or
1424 * from interrupt state @pri must be %GFP_ATOMIC
1426 * %NULL is returned on a memory allocation failure.
1428 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1431 might_sleep_if(gfpflags_allow_blocking(pri
));
1432 if (skb_cloned(skb
)) {
1433 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1435 /* Free our shared copy */
1446 * skb_peek - peek at the head of an &sk_buff_head
1447 * @list_: list to peek at
1449 * Peek an &sk_buff. Unlike most other operations you _MUST_
1450 * be careful with this one. A peek leaves the buffer on the
1451 * list and someone else may run off with it. You must hold
1452 * the appropriate locks or have a private queue to do this.
1454 * Returns %NULL for an empty list or a pointer to the head element.
1455 * The reference count is not incremented and the reference is therefore
1456 * volatile. Use with caution.
1458 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1460 struct sk_buff
*skb
= list_
->next
;
1462 if (skb
== (struct sk_buff
*)list_
)
1468 * skb_peek_next - peek skb following the given one from a queue
1469 * @skb: skb to start from
1470 * @list_: list to peek at
1472 * Returns %NULL when the end of the list is met or a pointer to the
1473 * next element. The reference count is not incremented and the
1474 * reference is therefore volatile. Use with caution.
1476 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1477 const struct sk_buff_head
*list_
)
1479 struct sk_buff
*next
= skb
->next
;
1481 if (next
== (struct sk_buff
*)list_
)
1487 * skb_peek_tail - peek at the tail of an &sk_buff_head
1488 * @list_: list to peek at
1490 * Peek an &sk_buff. Unlike most other operations you _MUST_
1491 * be careful with this one. A peek leaves the buffer on the
1492 * list and someone else may run off with it. You must hold
1493 * the appropriate locks or have a private queue to do this.
1495 * Returns %NULL for an empty list or a pointer to the tail element.
1496 * The reference count is not incremented and the reference is therefore
1497 * volatile. Use with caution.
1499 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1501 struct sk_buff
*skb
= list_
->prev
;
1503 if (skb
== (struct sk_buff
*)list_
)
1510 * skb_queue_len - get queue length
1511 * @list_: list to measure
1513 * Return the length of an &sk_buff queue.
1515 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1521 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1522 * @list: queue to initialize
1524 * This initializes only the list and queue length aspects of
1525 * an sk_buff_head object. This allows to initialize the list
1526 * aspects of an sk_buff_head without reinitializing things like
1527 * the spinlock. It can also be used for on-stack sk_buff_head
1528 * objects where the spinlock is known to not be used.
1530 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1532 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1537 * This function creates a split out lock class for each invocation;
1538 * this is needed for now since a whole lot of users of the skb-queue
1539 * infrastructure in drivers have different locking usage (in hardirq)
1540 * than the networking core (in softirq only). In the long run either the
1541 * network layer or drivers should need annotation to consolidate the
1542 * main types of usage into 3 classes.
1544 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1546 spin_lock_init(&list
->lock
);
1547 __skb_queue_head_init(list
);
1550 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1551 struct lock_class_key
*class)
1553 skb_queue_head_init(list
);
1554 lockdep_set_class(&list
->lock
, class);
1558 * Insert an sk_buff on a list.
1560 * The "__skb_xxxx()" functions are the non-atomic ones that
1561 * can only be called with interrupts disabled.
1563 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1564 struct sk_buff_head
*list
);
1565 static inline void __skb_insert(struct sk_buff
*newsk
,
1566 struct sk_buff
*prev
, struct sk_buff
*next
,
1567 struct sk_buff_head
*list
)
1571 next
->prev
= prev
->next
= newsk
;
1575 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1576 struct sk_buff
*prev
,
1577 struct sk_buff
*next
)
1579 struct sk_buff
*first
= list
->next
;
1580 struct sk_buff
*last
= list
->prev
;
1590 * skb_queue_splice - join two skb lists, this is designed for stacks
1591 * @list: the new list to add
1592 * @head: the place to add it in the first list
1594 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1595 struct sk_buff_head
*head
)
1597 if (!skb_queue_empty(list
)) {
1598 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1599 head
->qlen
+= list
->qlen
;
1604 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1605 * @list: the new list to add
1606 * @head: the place to add it in the first list
1608 * The list at @list is reinitialised
1610 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1611 struct sk_buff_head
*head
)
1613 if (!skb_queue_empty(list
)) {
1614 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1615 head
->qlen
+= list
->qlen
;
1616 __skb_queue_head_init(list
);
1621 * skb_queue_splice_tail - join two skb lists, each list being a queue
1622 * @list: the new list to add
1623 * @head: the place to add it in the first list
1625 static inline void skb_queue_splice_tail(const 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
;
1635 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1636 * @list: the new list to add
1637 * @head: the place to add it in the first list
1639 * Each of the lists is a queue.
1640 * The list at @list is reinitialised
1642 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1643 struct sk_buff_head
*head
)
1645 if (!skb_queue_empty(list
)) {
1646 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1647 head
->qlen
+= list
->qlen
;
1648 __skb_queue_head_init(list
);
1653 * __skb_queue_after - queue a buffer at the list head
1654 * @list: list to use
1655 * @prev: place after this buffer
1656 * @newsk: buffer to queue
1658 * Queue a buffer int the middle of a list. This function takes no locks
1659 * and you must therefore hold required locks before calling it.
1661 * A buffer cannot be placed on two lists at the same time.
1663 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1664 struct sk_buff
*prev
,
1665 struct sk_buff
*newsk
)
1667 __skb_insert(newsk
, prev
, prev
->next
, list
);
1670 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1671 struct sk_buff_head
*list
);
1673 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1674 struct sk_buff
*next
,
1675 struct sk_buff
*newsk
)
1677 __skb_insert(newsk
, next
->prev
, next
, list
);
1681 * __skb_queue_head - queue a buffer at the list head
1682 * @list: list to use
1683 * @newsk: buffer to queue
1685 * Queue a buffer at the start 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_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1691 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1692 struct sk_buff
*newsk
)
1694 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1698 * __skb_queue_tail - queue a buffer at the list tail
1699 * @list: list to use
1700 * @newsk: buffer to queue
1702 * Queue a buffer at the end of a list. This function takes no locks
1703 * and you must therefore hold required locks before calling it.
1705 * A buffer cannot be placed on two lists at the same time.
1707 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1708 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1709 struct sk_buff
*newsk
)
1711 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1715 * remove sk_buff from list. _Must_ be called atomically, and with
1718 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1719 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1721 struct sk_buff
*next
, *prev
;
1726 skb
->next
= skb
->prev
= NULL
;
1732 * __skb_dequeue - remove from the head of the queue
1733 * @list: list to dequeue from
1735 * Remove the head of the list. This function does not take any locks
1736 * so must be used with appropriate locks held only. The head item is
1737 * returned or %NULL if the list is empty.
1739 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1740 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1742 struct sk_buff
*skb
= skb_peek(list
);
1744 __skb_unlink(skb
, list
);
1749 * __skb_dequeue_tail - remove from the tail of the queue
1750 * @list: list to dequeue from
1752 * Remove the tail of the list. This function does not take any locks
1753 * so must be used with appropriate locks held only. The tail item is
1754 * returned or %NULL if the list is empty.
1756 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1757 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1759 struct sk_buff
*skb
= skb_peek_tail(list
);
1761 __skb_unlink(skb
, list
);
1766 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1768 return skb
->data_len
;
1771 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1773 return skb
->len
- skb
->data_len
;
1776 static inline int skb_pagelen(const struct sk_buff
*skb
)
1780 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1781 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1782 return len
+ skb_headlen(skb
);
1786 * __skb_fill_page_desc - initialise a paged fragment in an skb
1787 * @skb: buffer containing fragment to be initialised
1788 * @i: paged fragment index to initialise
1789 * @page: the page to use for this fragment
1790 * @off: the offset to the data with @page
1791 * @size: the length of the data
1793 * Initialises the @i'th fragment of @skb to point to &size bytes at
1794 * offset @off within @page.
1796 * Does not take any additional reference on the fragment.
1798 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1799 struct page
*page
, int off
, int size
)
1801 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1804 * Propagate page pfmemalloc to the skb if we can. The problem is
1805 * that not all callers have unique ownership of the page but rely
1806 * on page_is_pfmemalloc doing the right thing(tm).
1808 frag
->page
.p
= page
;
1809 frag
->page_offset
= off
;
1810 skb_frag_size_set(frag
, size
);
1812 page
= compound_head(page
);
1813 if (page_is_pfmemalloc(page
))
1814 skb
->pfmemalloc
= true;
1818 * skb_fill_page_desc - initialise a paged fragment in an skb
1819 * @skb: buffer containing fragment to be initialised
1820 * @i: paged fragment index to initialise
1821 * @page: the page to use for this fragment
1822 * @off: the offset to the data with @page
1823 * @size: the length of the data
1825 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1826 * @skb to point to @size bytes at offset @off within @page. In
1827 * addition updates @skb such that @i is the last fragment.
1829 * Does not take any additional reference on the fragment.
1831 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1832 struct page
*page
, int off
, int size
)
1834 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1835 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1838 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1839 int size
, unsigned int truesize
);
1841 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1842 unsigned int truesize
);
1844 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1845 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1846 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1848 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1849 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1851 return skb
->head
+ skb
->tail
;
1854 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1856 skb
->tail
= skb
->data
- skb
->head
;
1859 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1861 skb_reset_tail_pointer(skb
);
1862 skb
->tail
+= offset
;
1865 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1866 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1871 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1873 skb
->tail
= skb
->data
;
1876 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1878 skb
->tail
= skb
->data
+ offset
;
1881 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1884 * Add data to an sk_buff
1886 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1887 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1888 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1890 unsigned char *tmp
= skb_tail_pointer(skb
);
1891 SKB_LINEAR_ASSERT(skb
);
1897 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1898 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1905 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1906 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1909 BUG_ON(skb
->len
< skb
->data_len
);
1910 return skb
->data
+= len
;
1913 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1915 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1918 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1920 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1922 if (len
> skb_headlen(skb
) &&
1923 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1926 return skb
->data
+= len
;
1929 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1931 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1934 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1936 if (likely(len
<= skb_headlen(skb
)))
1938 if (unlikely(len
> skb
->len
))
1940 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1944 * skb_headroom - bytes at buffer head
1945 * @skb: buffer to check
1947 * Return the number of bytes of free space at the head of an &sk_buff.
1949 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1951 return skb
->data
- skb
->head
;
1955 * skb_tailroom - bytes at buffer end
1956 * @skb: buffer to check
1958 * Return the number of bytes of free space at the tail of an sk_buff
1960 static inline int skb_tailroom(const struct sk_buff
*skb
)
1962 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1966 * skb_availroom - bytes at buffer end
1967 * @skb: buffer to check
1969 * Return the number of bytes of free space at the tail of an sk_buff
1970 * allocated by sk_stream_alloc()
1972 static inline int skb_availroom(const struct sk_buff
*skb
)
1974 if (skb_is_nonlinear(skb
))
1977 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1981 * skb_reserve - adjust headroom
1982 * @skb: buffer to alter
1983 * @len: bytes to move
1985 * Increase the headroom of an empty &sk_buff by reducing the tail
1986 * room. This is only allowed for an empty buffer.
1988 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1995 * skb_tailroom_reserve - adjust reserved_tailroom
1996 * @skb: buffer to alter
1997 * @mtu: maximum amount of headlen permitted
1998 * @needed_tailroom: minimum amount of reserved_tailroom
2000 * Set reserved_tailroom so that headlen can be as large as possible but
2001 * not larger than mtu and tailroom cannot be smaller than
2003 * The required headroom should already have been reserved before using
2006 static inline void skb_tailroom_reserve(struct sk_buff
*skb
, unsigned int mtu
,
2007 unsigned int needed_tailroom
)
2009 SKB_LINEAR_ASSERT(skb
);
2010 if (mtu
< skb_tailroom(skb
) - needed_tailroom
)
2011 /* use at most mtu */
2012 skb
->reserved_tailroom
= skb_tailroom(skb
) - mtu
;
2014 /* use up to all available space */
2015 skb
->reserved_tailroom
= needed_tailroom
;
2018 #define ENCAP_TYPE_ETHER 0
2019 #define ENCAP_TYPE_IPPROTO 1
2021 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
2024 skb
->inner_protocol
= protocol
;
2025 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
2028 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
2031 skb
->inner_ipproto
= ipproto
;
2032 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
2035 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
2037 skb
->inner_mac_header
= skb
->mac_header
;
2038 skb
->inner_network_header
= skb
->network_header
;
2039 skb
->inner_transport_header
= skb
->transport_header
;
2042 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
2044 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
2047 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2050 return skb
->head
+ skb
->inner_transport_header
;
2053 static inline int skb_inner_transport_offset(const struct sk_buff
*skb
)
2055 return skb_inner_transport_header(skb
) - skb
->data
;
2058 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
2060 skb
->inner_transport_header
= skb
->data
- skb
->head
;
2063 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
2066 skb_reset_inner_transport_header(skb
);
2067 skb
->inner_transport_header
+= offset
;
2070 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
2072 return skb
->head
+ skb
->inner_network_header
;
2075 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
2077 skb
->inner_network_header
= skb
->data
- skb
->head
;
2080 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
2083 skb_reset_inner_network_header(skb
);
2084 skb
->inner_network_header
+= offset
;
2087 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
2089 return skb
->head
+ skb
->inner_mac_header
;
2092 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
2094 skb
->inner_mac_header
= skb
->data
- skb
->head
;
2097 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
2100 skb_reset_inner_mac_header(skb
);
2101 skb
->inner_mac_header
+= offset
;
2103 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
2105 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
2108 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
2110 return skb
->head
+ skb
->transport_header
;
2113 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
2115 skb
->transport_header
= skb
->data
- skb
->head
;
2118 static inline void skb_set_transport_header(struct sk_buff
*skb
,
2121 skb_reset_transport_header(skb
);
2122 skb
->transport_header
+= offset
;
2125 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
2127 return skb
->head
+ skb
->network_header
;
2130 static inline void skb_reset_network_header(struct sk_buff
*skb
)
2132 skb
->network_header
= skb
->data
- skb
->head
;
2135 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
2137 skb_reset_network_header(skb
);
2138 skb
->network_header
+= offset
;
2141 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
2143 return skb
->head
+ skb
->mac_header
;
2146 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
2148 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
2151 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
2153 skb
->mac_header
= skb
->data
- skb
->head
;
2156 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
2158 skb_reset_mac_header(skb
);
2159 skb
->mac_header
+= offset
;
2162 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
2164 skb
->mac_header
= skb
->network_header
;
2167 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
2168 const int offset_hint
)
2170 struct flow_keys keys
;
2172 if (skb_transport_header_was_set(skb
))
2174 else if (skb_flow_dissect_flow_keys(skb
, &keys
, 0))
2175 skb_set_transport_header(skb
, keys
.control
.thoff
);
2177 skb_set_transport_header(skb
, offset_hint
);
2180 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
2182 if (skb_mac_header_was_set(skb
)) {
2183 const unsigned char *old_mac
= skb_mac_header(skb
);
2185 skb_set_mac_header(skb
, -skb
->mac_len
);
2186 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
2190 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
2192 return skb
->csum_start
- skb_headroom(skb
);
2195 static inline unsigned char *skb_checksum_start(const struct sk_buff
*skb
)
2197 return skb
->head
+ skb
->csum_start
;
2200 static inline int skb_transport_offset(const struct sk_buff
*skb
)
2202 return skb_transport_header(skb
) - skb
->data
;
2205 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
2207 return skb
->transport_header
- skb
->network_header
;
2210 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
2212 return skb
->inner_transport_header
- skb
->inner_network_header
;
2215 static inline int skb_network_offset(const struct sk_buff
*skb
)
2217 return skb_network_header(skb
) - skb
->data
;
2220 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
2222 return skb_inner_network_header(skb
) - skb
->data
;
2225 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
2227 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
2231 * CPUs often take a performance hit when accessing unaligned memory
2232 * locations. The actual performance hit varies, it can be small if the
2233 * hardware handles it or large if we have to take an exception and fix it
2236 * Since an ethernet header is 14 bytes network drivers often end up with
2237 * the IP header at an unaligned offset. The IP header can be aligned by
2238 * shifting the start of the packet by 2 bytes. Drivers should do this
2241 * skb_reserve(skb, NET_IP_ALIGN);
2243 * The downside to this alignment of the IP header is that the DMA is now
2244 * unaligned. On some architectures the cost of an unaligned DMA is high
2245 * and this cost outweighs the gains made by aligning the IP header.
2247 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2250 #ifndef NET_IP_ALIGN
2251 #define NET_IP_ALIGN 2
2255 * The networking layer reserves some headroom in skb data (via
2256 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2257 * the header has to grow. In the default case, if the header has to grow
2258 * 32 bytes or less we avoid the reallocation.
2260 * Unfortunately this headroom changes the DMA alignment of the resulting
2261 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2262 * on some architectures. An architecture can override this value,
2263 * perhaps setting it to a cacheline in size (since that will maintain
2264 * cacheline alignment of the DMA). It must be a power of 2.
2266 * Various parts of the networking layer expect at least 32 bytes of
2267 * headroom, you should not reduce this.
2269 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2270 * to reduce average number of cache lines per packet.
2271 * get_rps_cpus() for example only access one 64 bytes aligned block :
2272 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2275 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2278 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2280 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2282 if (unlikely(skb_is_nonlinear(skb
))) {
2287 skb_set_tail_pointer(skb
, len
);
2290 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2292 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2295 return ___pskb_trim(skb
, len
);
2296 __skb_trim(skb
, len
);
2300 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2302 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2306 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2307 * @skb: buffer to alter
2310 * This is identical to pskb_trim except that the caller knows that
2311 * the skb is not cloned so we should never get an error due to out-
2314 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2316 int err
= pskb_trim(skb
, len
);
2321 * skb_orphan - orphan a buffer
2322 * @skb: buffer to orphan
2324 * If a buffer currently has an owner then we call the owner's
2325 * destructor function and make the @skb unowned. The buffer continues
2326 * to exist but is no longer charged to its former owner.
2328 static inline void skb_orphan(struct sk_buff
*skb
)
2330 if (skb
->destructor
) {
2331 skb
->destructor(skb
);
2332 skb
->destructor
= NULL
;
2340 * skb_orphan_frags - orphan the frags contained in a buffer
2341 * @skb: buffer to orphan frags from
2342 * @gfp_mask: allocation mask for replacement pages
2344 * For each frag in the SKB which needs a destructor (i.e. has an
2345 * owner) create a copy of that frag and release the original
2346 * page by calling the destructor.
2348 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2350 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
2352 return skb_copy_ubufs(skb
, gfp_mask
);
2356 * __skb_queue_purge - empty a list
2357 * @list: list to empty
2359 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2360 * the list and one reference dropped. This function does not take the
2361 * list lock and the caller must hold the relevant locks to use it.
2363 void skb_queue_purge(struct sk_buff_head
*list
);
2364 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2366 struct sk_buff
*skb
;
2367 while ((skb
= __skb_dequeue(list
)) != NULL
)
2371 void *netdev_alloc_frag(unsigned int fragsz
);
2373 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2377 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2378 * @dev: network device to receive on
2379 * @length: length to allocate
2381 * Allocate a new &sk_buff and assign it a usage count of one. The
2382 * buffer has unspecified headroom built in. Users should allocate
2383 * the headroom they think they need without accounting for the
2384 * built in space. The built in space is used for optimisations.
2386 * %NULL is returned if there is no free memory. Although this function
2387 * allocates memory it can be called from an interrupt.
2389 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2390 unsigned int length
)
2392 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2395 /* legacy helper around __netdev_alloc_skb() */
2396 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2399 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2402 /* legacy helper around netdev_alloc_skb() */
2403 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2405 return netdev_alloc_skb(NULL
, length
);
2409 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2410 unsigned int length
, gfp_t gfp
)
2412 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2414 if (NET_IP_ALIGN
&& skb
)
2415 skb_reserve(skb
, NET_IP_ALIGN
);
2419 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2420 unsigned int length
)
2422 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2425 static inline void skb_free_frag(void *addr
)
2427 __free_page_frag(addr
);
2430 void *napi_alloc_frag(unsigned int fragsz
);
2431 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2432 unsigned int length
, gfp_t gfp_mask
);
2433 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2434 unsigned int length
)
2436 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2438 void napi_consume_skb(struct sk_buff
*skb
, int budget
);
2440 void __kfree_skb_flush(void);
2441 void __kfree_skb_defer(struct sk_buff
*skb
);
2444 * __dev_alloc_pages - allocate page for network Rx
2445 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2446 * @order: size of the allocation
2448 * Allocate a new page.
2450 * %NULL is returned if there is no free memory.
2452 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2455 /* This piece of code contains several assumptions.
2456 * 1. This is for device Rx, therefor a cold page is preferred.
2457 * 2. The expectation is the user wants a compound page.
2458 * 3. If requesting a order 0 page it will not be compound
2459 * due to the check to see if order has a value in prep_new_page
2460 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2461 * code in gfp_to_alloc_flags that should be enforcing this.
2463 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2465 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2468 static inline struct page
*dev_alloc_pages(unsigned int order
)
2470 return __dev_alloc_pages(GFP_ATOMIC
| __GFP_NOWARN
, order
);
2474 * __dev_alloc_page - allocate a page for network Rx
2475 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2477 * Allocate a new page.
2479 * %NULL is returned if there is no free memory.
2481 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2483 return __dev_alloc_pages(gfp_mask
, 0);
2486 static inline struct page
*dev_alloc_page(void)
2488 return dev_alloc_pages(0);
2492 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2493 * @page: The page that was allocated from skb_alloc_page
2494 * @skb: The skb that may need pfmemalloc set
2496 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2497 struct sk_buff
*skb
)
2499 if (page_is_pfmemalloc(page
))
2500 skb
->pfmemalloc
= true;
2504 * skb_frag_page - retrieve the page referred to by a paged fragment
2505 * @frag: the paged fragment
2507 * Returns the &struct page associated with @frag.
2509 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2511 return frag
->page
.p
;
2515 * __skb_frag_ref - take an addition reference on a paged fragment.
2516 * @frag: the paged fragment
2518 * Takes an additional reference on the paged fragment @frag.
2520 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2522 get_page(skb_frag_page(frag
));
2526 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2528 * @f: the fragment offset.
2530 * Takes an additional reference on the @f'th paged fragment of @skb.
2532 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2534 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2538 * __skb_frag_unref - release a reference on a paged fragment.
2539 * @frag: the paged fragment
2541 * Releases a reference on the paged fragment @frag.
2543 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2545 put_page(skb_frag_page(frag
));
2549 * skb_frag_unref - release a reference on a paged fragment of an skb.
2551 * @f: the fragment offset
2553 * Releases a reference on the @f'th paged fragment of @skb.
2555 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2557 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2561 * skb_frag_address - gets the address of the data contained in a paged fragment
2562 * @frag: the paged fragment buffer
2564 * Returns the address of the data within @frag. The page must already
2567 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2569 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2573 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2574 * @frag: the paged fragment buffer
2576 * Returns the address of the data within @frag. Checks that the page
2577 * is mapped and returns %NULL otherwise.
2579 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2581 void *ptr
= page_address(skb_frag_page(frag
));
2585 return ptr
+ frag
->page_offset
;
2589 * __skb_frag_set_page - sets the page contained in a paged fragment
2590 * @frag: the paged fragment
2591 * @page: the page to set
2593 * Sets the fragment @frag to contain @page.
2595 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2597 frag
->page
.p
= page
;
2601 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2603 * @f: the fragment offset
2604 * @page: the page to set
2606 * Sets the @f'th fragment of @skb to contain @page.
2608 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2611 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2614 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2617 * skb_frag_dma_map - maps a paged fragment via the DMA API
2618 * @dev: the device to map the fragment to
2619 * @frag: the paged fragment to map
2620 * @offset: the offset within the fragment (starting at the
2621 * fragment's own offset)
2622 * @size: the number of bytes to map
2623 * @dir: the direction of the mapping (%PCI_DMA_*)
2625 * Maps the page associated with @frag to @device.
2627 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2628 const skb_frag_t
*frag
,
2629 size_t offset
, size_t size
,
2630 enum dma_data_direction dir
)
2632 return dma_map_page(dev
, skb_frag_page(frag
),
2633 frag
->page_offset
+ offset
, size
, dir
);
2636 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2639 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2643 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2646 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2651 * skb_clone_writable - is the header of a clone writable
2652 * @skb: buffer to check
2653 * @len: length up to which to write
2655 * Returns true if modifying the header part of the cloned buffer
2656 * does not requires the data to be copied.
2658 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2660 return !skb_header_cloned(skb
) &&
2661 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2664 static inline int skb_try_make_writable(struct sk_buff
*skb
,
2665 unsigned int write_len
)
2667 return skb_cloned(skb
) && !skb_clone_writable(skb
, write_len
) &&
2668 pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
);
2671 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2676 if (headroom
> skb_headroom(skb
))
2677 delta
= headroom
- skb_headroom(skb
);
2679 if (delta
|| cloned
)
2680 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2686 * skb_cow - copy header of skb when it is required
2687 * @skb: buffer to cow
2688 * @headroom: needed headroom
2690 * If the skb passed lacks sufficient headroom or its data part
2691 * is shared, data is reallocated. If reallocation fails, an error
2692 * is returned and original skb is not changed.
2694 * The result is skb with writable area skb->head...skb->tail
2695 * and at least @headroom of space at head.
2697 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2699 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2703 * skb_cow_head - skb_cow but only making the head writable
2704 * @skb: buffer to cow
2705 * @headroom: needed headroom
2707 * This function is identical to skb_cow except that we replace the
2708 * skb_cloned check by skb_header_cloned. It should be used when
2709 * you only need to push on some header and do not need to modify
2712 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2714 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2718 * skb_padto - pad an skbuff up to a minimal size
2719 * @skb: buffer to pad
2720 * @len: minimal length
2722 * Pads up a buffer to ensure the trailing bytes exist and are
2723 * blanked. If the buffer already contains sufficient data it
2724 * is untouched. Otherwise it is extended. Returns zero on
2725 * success. The skb is freed on error.
2727 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2729 unsigned int size
= skb
->len
;
2730 if (likely(size
>= len
))
2732 return skb_pad(skb
, len
- size
);
2736 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2737 * @skb: buffer to pad
2738 * @len: minimal length
2740 * Pads up a buffer to ensure the trailing bytes exist and are
2741 * blanked. If the buffer already contains sufficient data it
2742 * is untouched. Otherwise it is extended. Returns zero on
2743 * success. The skb is freed on error.
2745 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2747 unsigned int size
= skb
->len
;
2749 if (unlikely(size
< len
)) {
2751 if (skb_pad(skb
, len
))
2753 __skb_put(skb
, len
);
2758 static inline int skb_add_data(struct sk_buff
*skb
,
2759 struct iov_iter
*from
, int copy
)
2761 const int off
= skb
->len
;
2763 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2765 if (csum_and_copy_from_iter(skb_put(skb
, copy
), copy
,
2766 &csum
, from
) == copy
) {
2767 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2770 } else if (copy_from_iter(skb_put(skb
, copy
), copy
, from
) == copy
)
2773 __skb_trim(skb
, off
);
2777 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2778 const struct page
*page
, int off
)
2781 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2783 return page
== skb_frag_page(frag
) &&
2784 off
== frag
->page_offset
+ skb_frag_size(frag
);
2789 static inline int __skb_linearize(struct sk_buff
*skb
)
2791 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2795 * skb_linearize - convert paged skb to linear one
2796 * @skb: buffer to linarize
2798 * If there is no free memory -ENOMEM is returned, otherwise zero
2799 * is returned and the old skb data released.
2801 static inline int skb_linearize(struct sk_buff
*skb
)
2803 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2807 * skb_has_shared_frag - can any frag be overwritten
2808 * @skb: buffer to test
2810 * Return true if the skb has at least one frag that might be modified
2811 * by an external entity (as in vmsplice()/sendfile())
2813 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2815 return skb_is_nonlinear(skb
) &&
2816 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2820 * skb_linearize_cow - make sure skb is linear and writable
2821 * @skb: buffer to process
2823 * If there is no free memory -ENOMEM is returned, otherwise zero
2824 * is returned and the old skb data released.
2826 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2828 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2829 __skb_linearize(skb
) : 0;
2833 * skb_postpull_rcsum - update checksum for received skb after pull
2834 * @skb: buffer to update
2835 * @start: start of data before pull
2836 * @len: length of data pulled
2838 * After doing a pull on a received packet, you need to call this to
2839 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2840 * CHECKSUM_NONE so that it can be recomputed from scratch.
2843 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2844 const void *start
, unsigned int len
)
2846 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2847 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2848 else if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
2849 skb_checksum_start_offset(skb
) < 0)
2850 skb
->ip_summed
= CHECKSUM_NONE
;
2853 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2855 static inline void skb_postpush_rcsum(struct sk_buff
*skb
,
2856 const void *start
, unsigned int len
)
2858 /* For performing the reverse operation to skb_postpull_rcsum(),
2859 * we can instead of ...
2861 * skb->csum = csum_add(skb->csum, csum_partial(start, len, 0));
2863 * ... just use this equivalent version here to save a few
2864 * instructions. Feeding csum of 0 in csum_partial() and later
2865 * on adding skb->csum is equivalent to feed skb->csum in the
2868 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2869 skb
->csum
= csum_partial(start
, len
, skb
->csum
);
2873 * pskb_trim_rcsum - trim received skb and update checksum
2874 * @skb: buffer to trim
2877 * This is exactly the same as pskb_trim except that it ensures the
2878 * checksum of received packets are still valid after the operation.
2881 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2883 if (likely(len
>= skb
->len
))
2885 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2886 skb
->ip_summed
= CHECKSUM_NONE
;
2887 return __pskb_trim(skb
, len
);
2890 #define skb_queue_walk(queue, skb) \
2891 for (skb = (queue)->next; \
2892 skb != (struct sk_buff *)(queue); \
2895 #define skb_queue_walk_safe(queue, skb, tmp) \
2896 for (skb = (queue)->next, tmp = skb->next; \
2897 skb != (struct sk_buff *)(queue); \
2898 skb = tmp, tmp = skb->next)
2900 #define skb_queue_walk_from(queue, skb) \
2901 for (; skb != (struct sk_buff *)(queue); \
2904 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2905 for (tmp = skb->next; \
2906 skb != (struct sk_buff *)(queue); \
2907 skb = tmp, tmp = skb->next)
2909 #define skb_queue_reverse_walk(queue, skb) \
2910 for (skb = (queue)->prev; \
2911 skb != (struct sk_buff *)(queue); \
2914 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2915 for (skb = (queue)->prev, tmp = skb->prev; \
2916 skb != (struct sk_buff *)(queue); \
2917 skb = tmp, tmp = skb->prev)
2919 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2920 for (tmp = skb->prev; \
2921 skb != (struct sk_buff *)(queue); \
2922 skb = tmp, tmp = skb->prev)
2924 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2926 return skb_shinfo(skb
)->frag_list
!= NULL
;
2929 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2931 skb_shinfo(skb
)->frag_list
= NULL
;
2934 #define skb_walk_frags(skb, iter) \
2935 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2938 int __skb_wait_for_more_packets(struct sock
*sk
, int *err
, long *timeo_p
,
2939 const struct sk_buff
*skb
);
2940 struct sk_buff
*__skb_try_recv_datagram(struct sock
*sk
, unsigned flags
,
2941 int *peeked
, int *off
, int *err
,
2942 struct sk_buff
**last
);
2943 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2944 int *peeked
, int *off
, int *err
);
2945 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
2947 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2948 struct poll_table_struct
*wait
);
2949 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
2950 struct iov_iter
*to
, int size
);
2951 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
2952 struct msghdr
*msg
, int size
)
2954 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
2956 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
2957 struct msghdr
*msg
);
2958 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
2959 struct iov_iter
*from
, int len
);
2960 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
2961 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2962 void __skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
, int len
);
2963 static inline void skb_free_datagram_locked(struct sock
*sk
,
2964 struct sk_buff
*skb
)
2966 __skb_free_datagram_locked(sk
, skb
, 0);
2968 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
2969 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
2970 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
2971 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
2972 int len
, __wsum csum
);
2973 ssize_t
skb_socket_splice(struct sock
*sk
,
2974 struct pipe_inode_info
*pipe
,
2975 struct splice_pipe_desc
*spd
);
2976 int skb_splice_bits(struct sk_buff
*skb
, struct sock
*sk
, unsigned int offset
,
2977 struct pipe_inode_info
*pipe
, unsigned int len
,
2979 ssize_t (*splice_cb
)(struct sock
*,
2980 struct pipe_inode_info
*,
2981 struct splice_pipe_desc
*));
2982 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2983 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
2984 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
2986 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
2987 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
2988 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
2989 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
2990 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
2991 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
2992 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
2993 int skb_vlan_pop(struct sk_buff
*skb
);
2994 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
2995 struct sk_buff
*pskb_extract(struct sk_buff
*skb
, int off
, int to_copy
,
2998 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
3000 return copy_from_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3003 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
3005 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
3008 struct skb_checksum_ops
{
3009 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
3010 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
3013 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3014 __wsum csum
, const struct skb_checksum_ops
*ops
);
3015 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
3018 static inline void * __must_check
3019 __skb_header_pointer(const struct sk_buff
*skb
, int offset
,
3020 int len
, void *data
, int hlen
, void *buffer
)
3022 if (hlen
- offset
>= len
)
3023 return data
+ offset
;
3026 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
3032 static inline void * __must_check
3033 skb_header_pointer(const struct sk_buff
*skb
, int offset
, int len
, void *buffer
)
3035 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
3036 skb_headlen(skb
), buffer
);
3040 * skb_needs_linearize - check if we need to linearize a given skb
3041 * depending on the given device features.
3042 * @skb: socket buffer to check
3043 * @features: net device features
3045 * Returns true if either:
3046 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3047 * 2. skb is fragmented and the device does not support SG.
3049 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
3050 netdev_features_t features
)
3052 return skb_is_nonlinear(skb
) &&
3053 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
3054 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
3057 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
3059 const unsigned int len
)
3061 memcpy(to
, skb
->data
, len
);
3064 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
3065 const int offset
, void *to
,
3066 const unsigned int len
)
3068 memcpy(to
, skb
->data
+ offset
, len
);
3071 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
3073 const unsigned int len
)
3075 memcpy(skb
->data
, from
, len
);
3078 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
3081 const unsigned int len
)
3083 memcpy(skb
->data
+ offset
, from
, len
);
3086 void skb_init(void);
3088 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
3094 * skb_get_timestamp - get timestamp from a skb
3095 * @skb: skb to get stamp from
3096 * @stamp: pointer to struct timeval to store stamp in
3098 * Timestamps are stored in the skb as offsets to a base timestamp.
3099 * This function converts the offset back to a struct timeval and stores
3102 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
3103 struct timeval
*stamp
)
3105 *stamp
= ktime_to_timeval(skb
->tstamp
);
3108 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
3109 struct timespec
*stamp
)
3111 *stamp
= ktime_to_timespec(skb
->tstamp
);
3114 static inline void __net_timestamp(struct sk_buff
*skb
)
3116 skb
->tstamp
= ktime_get_real();
3119 static inline ktime_t
net_timedelta(ktime_t t
)
3121 return ktime_sub(ktime_get_real(), t
);
3124 static inline ktime_t
net_invalid_timestamp(void)
3126 return ktime_set(0, 0);
3129 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
3131 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3133 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
3134 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
3136 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3138 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
3142 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
3147 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3150 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3152 * PHY drivers may accept clones of transmitted packets for
3153 * timestamping via their phy_driver.txtstamp method. These drivers
3154 * must call this function to return the skb back to the stack with a
3157 * @skb: clone of the the original outgoing packet
3158 * @hwtstamps: hardware time stamps
3161 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
3162 struct skb_shared_hwtstamps
*hwtstamps
);
3164 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
3165 struct skb_shared_hwtstamps
*hwtstamps
,
3166 struct sock
*sk
, int tstype
);
3169 * skb_tstamp_tx - queue clone of skb with send time stamps
3170 * @orig_skb: the original outgoing packet
3171 * @hwtstamps: hardware time stamps, may be NULL if not available
3173 * If the skb has a socket associated, then this function clones the
3174 * skb (thus sharing the actual data and optional structures), stores
3175 * the optional hardware time stamping information (if non NULL) or
3176 * generates a software time stamp (otherwise), then queues the clone
3177 * to the error queue of the socket. Errors are silently ignored.
3179 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
3180 struct skb_shared_hwtstamps
*hwtstamps
);
3182 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
3184 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
3185 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
3186 skb_tstamp_tx(skb
, NULL
);
3190 * skb_tx_timestamp() - Driver hook for transmit timestamping
3192 * Ethernet MAC Drivers should call this function in their hard_xmit()
3193 * function immediately before giving the sk_buff to the MAC hardware.
3195 * Specifically, one should make absolutely sure that this function is
3196 * called before TX completion of this packet can trigger. Otherwise
3197 * the packet could potentially already be freed.
3199 * @skb: A socket buffer.
3201 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
3203 skb_clone_tx_timestamp(skb
);
3204 sw_tx_timestamp(skb
);
3208 * skb_complete_wifi_ack - deliver skb with wifi status
3210 * @skb: the original outgoing packet
3211 * @acked: ack status
3214 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
3216 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
3217 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
3219 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
3221 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
3223 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
3224 skb_checksum_start_offset(skb
) >= 0));
3228 * skb_checksum_complete - Calculate checksum of an entire packet
3229 * @skb: packet to process
3231 * This function calculates the checksum over the entire packet plus
3232 * the value of skb->csum. The latter can be used to supply the
3233 * checksum of a pseudo header as used by TCP/UDP. It returns the
3236 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3237 * this function can be used to verify that checksum on received
3238 * packets. In that case the function should return zero if the
3239 * checksum is correct. In particular, this function will return zero
3240 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3241 * hardware has already verified the correctness of the checksum.
3243 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
3245 return skb_csum_unnecessary(skb
) ?
3246 0 : __skb_checksum_complete(skb
);
3249 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
3251 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3252 if (skb
->csum_level
== 0)
3253 skb
->ip_summed
= CHECKSUM_NONE
;
3259 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
3261 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
3262 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
3264 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
3265 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
3266 skb
->csum_level
= 0;
3270 static inline void __skb_mark_checksum_bad(struct sk_buff
*skb
)
3272 /* Mark current checksum as bad (typically called from GRO
3273 * path). In the case that ip_summed is CHECKSUM_NONE
3274 * this must be the first checksum encountered in the packet.
3275 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
3276 * checksum after the last one validated. For UDP, a zero
3277 * checksum can not be marked as bad.
3280 if (skb
->ip_summed
== CHECKSUM_NONE
||
3281 skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
3285 /* Check if we need to perform checksum complete validation.
3287 * Returns true if checksum complete is needed, false otherwise
3288 * (either checksum is unnecessary or zero checksum is allowed).
3290 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3294 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3295 skb
->csum_valid
= 1;
3296 __skb_decr_checksum_unnecessary(skb
);
3303 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3306 #define CHECKSUM_BREAK 76
3308 /* Unset checksum-complete
3310 * Unset checksum complete can be done when packet is being modified
3311 * (uncompressed for instance) and checksum-complete value is
3314 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3316 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3317 skb
->ip_summed
= CHECKSUM_NONE
;
3320 /* Validate (init) checksum based on checksum complete.
3323 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3324 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3325 * checksum is stored in skb->csum for use in __skb_checksum_complete
3326 * non-zero: value of invalid checksum
3329 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3333 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3334 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3335 skb
->csum_valid
= 1;
3338 } else if (skb
->csum_bad
) {
3339 /* ip_summed == CHECKSUM_NONE in this case */
3340 return (__force __sum16
)1;
3345 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3348 csum
= __skb_checksum_complete(skb
);
3349 skb
->csum_valid
= !csum
;
3356 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3361 /* Perform checksum validate (init). Note that this is a macro since we only
3362 * want to calculate the pseudo header which is an input function if necessary.
3363 * First we try to validate without any computation (checksum unnecessary) and
3364 * then calculate based on checksum complete calling the function to compute
3368 * 0: checksum is validated or try to in skb_checksum_complete
3369 * non-zero: value of invalid checksum
3371 #define __skb_checksum_validate(skb, proto, complete, \
3372 zero_okay, check, compute_pseudo) \
3374 __sum16 __ret = 0; \
3375 skb->csum_valid = 0; \
3376 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3377 __ret = __skb_checksum_validate_complete(skb, \
3378 complete, compute_pseudo(skb, proto)); \
3382 #define skb_checksum_init(skb, proto, compute_pseudo) \
3383 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3385 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3386 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3388 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3389 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3391 #define skb_checksum_validate_zero_check(skb, proto, check, \
3393 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3395 #define skb_checksum_simple_validate(skb) \
3396 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3398 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3400 return (skb
->ip_summed
== CHECKSUM_NONE
&&
3401 skb
->csum_valid
&& !skb
->csum_bad
);
3404 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3405 __sum16 check
, __wsum pseudo
)
3407 skb
->csum
= ~pseudo
;
3408 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3411 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3413 if (__skb_checksum_convert_check(skb)) \
3414 __skb_checksum_convert(skb, check, \
3415 compute_pseudo(skb, proto)); \
3418 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3419 u16 start
, u16 offset
)
3421 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3422 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3423 skb
->csum_offset
= offset
- start
;
3426 /* Update skbuf and packet to reflect the remote checksum offload operation.
3427 * When called, ptr indicates the starting point for skb->csum when
3428 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3429 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3431 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3432 int start
, int offset
, bool nopartial
)
3437 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3441 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3442 __skb_checksum_complete(skb
);
3443 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3446 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3448 /* Adjust skb->csum since we changed the packet */
3449 skb
->csum
= csum_add(skb
->csum
, delta
);
3452 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3453 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3454 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3456 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3457 nf_conntrack_destroy(nfct
);
3459 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3462 atomic_inc(&nfct
->use
);
3465 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3466 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3468 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
3471 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3474 atomic_inc(&nf_bridge
->use
);
3476 #endif /* CONFIG_BRIDGE_NETFILTER */
3477 static inline void nf_reset(struct sk_buff
*skb
)
3479 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3480 nf_conntrack_put(skb
->nfct
);
3483 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3484 nf_bridge_put(skb
->nf_bridge
);
3485 skb
->nf_bridge
= NULL
;
3489 static inline void nf_reset_trace(struct sk_buff
*skb
)
3491 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3496 /* Note: This doesn't put any conntrack and bridge info in dst. */
3497 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3500 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3501 dst
->nfct
= src
->nfct
;
3502 nf_conntrack_get(src
->nfct
);
3504 dst
->nfctinfo
= src
->nfctinfo
;
3506 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3507 dst
->nf_bridge
= src
->nf_bridge
;
3508 nf_bridge_get(src
->nf_bridge
);
3510 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3512 dst
->nf_trace
= src
->nf_trace
;
3516 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3518 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3519 nf_conntrack_put(dst
->nfct
);
3521 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3522 nf_bridge_put(dst
->nf_bridge
);
3524 __nf_copy(dst
, src
, true);
3527 #ifdef CONFIG_NETWORK_SECMARK
3528 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3530 to
->secmark
= from
->secmark
;
3533 static inline void skb_init_secmark(struct sk_buff
*skb
)
3538 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3541 static inline void skb_init_secmark(struct sk_buff
*skb
)
3545 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3547 return !skb
->destructor
&&
3548 #if IS_ENABLED(CONFIG_XFRM)
3551 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3554 !skb
->_skb_refdst
&&
3555 !skb_has_frag_list(skb
);
3558 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3560 skb
->queue_mapping
= queue_mapping
;
3563 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3565 return skb
->queue_mapping
;
3568 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3570 to
->queue_mapping
= from
->queue_mapping
;
3573 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3575 skb
->queue_mapping
= rx_queue
+ 1;
3578 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3580 return skb
->queue_mapping
- 1;
3583 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3585 return skb
->queue_mapping
!= 0;
3588 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3597 /* Keeps track of mac header offset relative to skb->head.
3598 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3599 * For non-tunnel skb it points to skb_mac_header() and for
3600 * tunnel skb it points to outer mac header.
3601 * Keeps track of level of encapsulation of network headers.
3612 #define SKB_SGO_CB_OFFSET 32
3613 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
3615 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3617 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3618 SKB_GSO_CB(inner_skb
)->mac_offset
;
3621 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3623 int new_headroom
, headroom
;
3626 headroom
= skb_headroom(skb
);
3627 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3631 new_headroom
= skb_headroom(skb
);
3632 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3636 static inline void gso_reset_checksum(struct sk_buff
*skb
, __wsum res
)
3638 /* Do not update partial checksums if remote checksum is enabled. */
3639 if (skb
->remcsum_offload
)
3642 SKB_GSO_CB(skb
)->csum
= res
;
3643 SKB_GSO_CB(skb
)->csum_start
= skb_checksum_start(skb
) - skb
->head
;
3646 /* Compute the checksum for a gso segment. First compute the checksum value
3647 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3648 * then add in skb->csum (checksum from csum_start to end of packet).
3649 * skb->csum and csum_start are then updated to reflect the checksum of the
3650 * resultant packet starting from the transport header-- the resultant checksum
3651 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3654 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3656 unsigned char *csum_start
= skb_transport_header(skb
);
3657 int plen
= (skb
->head
+ SKB_GSO_CB(skb
)->csum_start
) - csum_start
;
3658 __wsum partial
= SKB_GSO_CB(skb
)->csum
;
3660 SKB_GSO_CB(skb
)->csum
= res
;
3661 SKB_GSO_CB(skb
)->csum_start
= csum_start
- skb
->head
;
3663 return csum_fold(csum_partial(csum_start
, plen
, partial
));
3666 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3668 return skb_shinfo(skb
)->gso_size
;
3671 /* Note: Should be called only if skb_is_gso(skb) is true */
3672 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3674 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3677 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3679 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3681 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3682 * wanted then gso_type will be set. */
3683 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3685 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3686 unlikely(shinfo
->gso_type
== 0)) {
3687 __skb_warn_lro_forwarding(skb
);
3693 static inline void skb_forward_csum(struct sk_buff
*skb
)
3695 /* Unfortunately we don't support this one. Any brave souls? */
3696 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3697 skb
->ip_summed
= CHECKSUM_NONE
;
3701 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3702 * @skb: skb to check
3704 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3705 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3706 * use this helper, to document places where we make this assertion.
3708 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3711 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3715 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3717 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3718 struct sk_buff
*skb_checksum_trimmed(struct sk_buff
*skb
,
3719 unsigned int transport_len
,
3720 __sum16(*skb_chkf
)(struct sk_buff
*skb
));
3723 * skb_head_is_locked - Determine if the skb->head is locked down
3724 * @skb: skb to check
3726 * The head on skbs build around a head frag can be removed if they are
3727 * not cloned. This function returns true if the skb head is locked down
3728 * due to either being allocated via kmalloc, or by being a clone with
3729 * multiple references to the head.
3731 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3733 return !skb
->head_frag
|| skb_cloned(skb
);
3737 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3741 * skb_gso_network_seglen is used to determine the real size of the
3742 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3744 * The MAC/L2 header is not accounted for.
3746 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3748 unsigned int hdr_len
= skb_transport_header(skb
) -
3749 skb_network_header(skb
);
3750 return hdr_len
+ skb_gso_transport_seglen(skb
);
3753 /* Local Checksum Offload.
3754 * Compute outer checksum based on the assumption that the
3755 * inner checksum will be offloaded later.
3756 * See Documentation/networking/checksum-offloads.txt for
3757 * explanation of how this works.
3758 * Fill in outer checksum adjustment (e.g. with sum of outer
3759 * pseudo-header) before calling.
3760 * Also ensure that inner checksum is in linear data area.
3762 static inline __wsum
lco_csum(struct sk_buff
*skb
)
3764 unsigned char *csum_start
= skb_checksum_start(skb
);
3765 unsigned char *l4_hdr
= skb_transport_header(skb
);
3768 /* Start with complement of inner checksum adjustment */
3769 partial
= ~csum_unfold(*(__force __sum16
*)(csum_start
+
3772 /* Add in checksum of our headers (incl. outer checksum
3773 * adjustment filled in by caller) and return result.
3775 return csum_partial(l4_hdr
, csum_start
- l4_hdr
, partial
);
3778 #endif /* __KERNEL__ */
3779 #endif /* _LINUX_SKBUFF_H */