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 */