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_keys.h>
39 /* A. Checksumming of received packets by device.
43 * Device failed to checksum this packet e.g. due to lack of capabilities.
44 * The packet contains full (though not verified) checksum in packet but
45 * not in skb->csum. Thus, skb->csum is undefined in this case.
47 * CHECKSUM_UNNECESSARY:
49 * The hardware you're dealing with doesn't calculate the full checksum
50 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
51 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
52 * if their checksums are okay. skb->csum is still undefined in this case
53 * though. It is a bad option, but, unfortunately, nowadays most vendors do
54 * this. Apparently with the secret goal to sell you new devices, when you
55 * will add new protocol to your host, f.e. IPv6 8)
57 * CHECKSUM_UNNECESSARY is applicable to following protocols:
59 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
60 * zero UDP checksum for either IPv4 or IPv6, the networking stack
61 * may perform further validation in this case.
62 * GRE: only if the checksum is present in the header.
63 * SCTP: indicates the CRC in SCTP header has been validated.
65 * skb->csum_level indicates the number of consecutive checksums found in
66 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
67 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
68 * and a device is able to verify the checksums for UDP (possibly zero),
69 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
70 * two. If the device were only able to verify the UDP checksum and not
71 * GRE, either because it doesn't support GRE checksum of because GRE
72 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
73 * not considered in this case).
77 * This is the most generic way. The device supplied checksum of the _whole_
78 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
79 * hardware doesn't need to parse L3/L4 headers to implement this.
81 * Note: Even if device supports only some protocols, but is able to produce
82 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
86 * A checksum is set up to be offloaded to a device as described in the
87 * output description for CHECKSUM_PARTIAL. This may occur on a packet
88 * received directly from another Linux OS, e.g., a virtualized Linux kernel
89 * on the same host, or it may be set in the input path in GRO or remote
90 * checksum offload. For the purposes of checksum verification, the checksum
91 * referred to by skb->csum_start + skb->csum_offset and any preceding
92 * checksums in the packet are considered verified. Any checksums in the
93 * packet that are after the checksum being offloaded are not considered to
96 * B. Checksumming on output.
100 * The skb was already checksummed by the protocol, or a checksum is not
105 * The device is required to checksum the packet as seen by hard_start_xmit()
106 * from skb->csum_start up to the end, and to record/write the checksum at
107 * offset skb->csum_start + skb->csum_offset.
109 * The device must show its capabilities in dev->features, set up at device
110 * setup time, e.g. netdev_features.h:
112 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
113 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
114 * IPv4. Sigh. Vendors like this way for an unknown reason.
115 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
116 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
117 * NETIF_F_... - Well, you get the picture.
119 * CHECKSUM_UNNECESSARY:
121 * Normally, the device will do per protocol specific checksumming. Protocol
122 * implementations that do not want the NIC to perform the checksum
123 * calculation should use this flag in their outgoing skbs.
125 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
126 * offload. Correspondingly, the FCoE protocol driver
127 * stack should use CHECKSUM_UNNECESSARY.
129 * Any questions? No questions, good. --ANK
132 /* Don't change this without changing skb_csum_unnecessary! */
133 #define CHECKSUM_NONE 0
134 #define CHECKSUM_UNNECESSARY 1
135 #define CHECKSUM_COMPLETE 2
136 #define CHECKSUM_PARTIAL 3
138 /* Maximum value in skb->csum_level */
139 #define SKB_MAX_CSUM_LEVEL 3
141 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
142 #define SKB_WITH_OVERHEAD(X) \
143 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
144 #define SKB_MAX_ORDER(X, ORDER) \
145 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
146 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
147 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
149 /* return minimum truesize of one skb containing X bytes of data */
150 #define SKB_TRUESIZE(X) ((X) + \
151 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
152 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
156 struct pipe_inode_info;
160 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
161 struct nf_conntrack {
166 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
167 struct nf_bridge_info {
170 BRNF_PROTO_UNCHANGED,
176 struct net_device *physindev;
177 struct net_device *physoutdev;
178 char neigh_header[8];
183 struct sk_buff_head {
184 /* These two members must be first. */
185 struct sk_buff *next;
186 struct sk_buff *prev;
190 raw_spinlock_t raw_lock;
195 /* To allow 64K frame to be packed as single skb without frag_list we
196 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
197 * buffers which do not start on a page boundary.
199 * Since GRO uses frags we allocate at least 16 regardless of page
202 #if (65536/PAGE_SIZE + 1) < 16
203 #define MAX_SKB_FRAGS 16UL
205 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
208 typedef struct skb_frag_struct skb_frag_t;
210 struct skb_frag_struct {
214 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
223 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
228 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
233 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
238 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
243 #define HAVE_HW_TIME_STAMP
246 * struct skb_shared_hwtstamps - hardware time stamps
247 * @hwtstamp: hardware time stamp transformed into duration
248 * since arbitrary point in time
250 * Software time stamps generated by ktime_get_real() are stored in
253 * hwtstamps can only be compared against other hwtstamps from
256 * This structure is attached to packets as part of the
257 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
259 struct skb_shared_hwtstamps {
263 /* Definitions for tx_flags in struct skb_shared_info */
265 /* generate hardware time stamp */
266 SKBTX_HW_TSTAMP = 1 << 0,
268 /* generate software time stamp when queueing packet to NIC */
269 SKBTX_SW_TSTAMP = 1 << 1,
271 /* device driver is going to provide hardware time stamp */
272 SKBTX_IN_PROGRESS = 1 << 2,
274 /* device driver supports TX zero-copy buffers */
275 SKBTX_DEV_ZEROCOPY = 1 << 3,
277 /* generate wifi status information (where possible) */
278 SKBTX_WIFI_STATUS = 1 << 4,
280 /* This indicates at least one fragment might be overwritten
281 * (as in vmsplice(), sendfile() ...)
282 * If we need to compute a TX checksum, we'll need to copy
283 * all frags to avoid possible bad checksum
285 SKBTX_SHARED_FRAG = 1 << 5,
287 /* generate software time stamp when entering packet scheduling */
288 SKBTX_SCHED_TSTAMP = 1 << 6,
290 /* generate software timestamp on peer data acknowledgment */
291 SKBTX_ACK_TSTAMP = 1 << 7,
294 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
295 SKBTX_SCHED_TSTAMP | \
297 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
300 * The callback notifies userspace to release buffers when skb DMA is done in
301 * lower device, the skb last reference should be 0 when calling this.
302 * The zerocopy_success argument is true if zero copy transmit occurred,
303 * false on data copy or out of memory error caused by data copy attempt.
304 * The ctx field is used to track device context.
305 * The desc field is used to track userspace buffer index.
308 void (*callback)(struct ubuf_info *, bool zerocopy_success);
313 /* This data is invariant across clones and lives at
314 * the end of the header data, ie. at skb->end.
316 struct skb_shared_info {
317 unsigned char nr_frags;
319 unsigned short gso_size;
320 /* Warning: this field is not always filled in (UFO)! */
321 unsigned short gso_segs;
322 unsigned short gso_type;
323 struct sk_buff *frag_list;
324 struct skb_shared_hwtstamps hwtstamps;
329 * Warning : all fields before dataref are cleared in __alloc_skb()
333 /* Intermediate layers must ensure that destructor_arg
334 * remains valid until skb destructor */
335 void * destructor_arg;
337 /* must be last field, see pskb_expand_head() */
338 skb_frag_t frags[MAX_SKB_FRAGS];
341 /* We divide dataref into two halves. The higher 16 bits hold references
342 * to the payload part of skb->data. The lower 16 bits hold references to
343 * the entire skb->data. A clone of a headerless skb holds the length of
344 * the header in skb->hdr_len.
346 * All users must obey the rule that the skb->data reference count must be
347 * greater than or equal to the payload reference count.
349 * Holding a reference to the payload part means that the user does not
350 * care about modifications to the header part of skb->data.
352 #define SKB_DATAREF_SHIFT 16
353 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
357 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
358 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
359 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
363 SKB_GSO_TCPV4 = 1 << 0,
364 SKB_GSO_UDP = 1 << 1,
366 /* This indicates the skb is from an untrusted source. */
367 SKB_GSO_DODGY = 1 << 2,
369 /* This indicates the tcp segment has CWR set. */
370 SKB_GSO_TCP_ECN = 1 << 3,
372 SKB_GSO_TCPV6 = 1 << 4,
374 SKB_GSO_FCOE = 1 << 5,
376 SKB_GSO_GRE = 1 << 6,
378 SKB_GSO_GRE_CSUM = 1 << 7,
380 SKB_GSO_IPIP = 1 << 8,
382 SKB_GSO_SIT = 1 << 9,
384 SKB_GSO_UDP_TUNNEL = 1 << 10,
386 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
388 SKB_GSO_TUNNEL_REMCSUM = 1 << 12,
391 #if BITS_PER_LONG > 32
392 #define NET_SKBUFF_DATA_USES_OFFSET 1
395 #ifdef NET_SKBUFF_DATA_USES_OFFSET
396 typedef unsigned int sk_buff_data_t;
398 typedef unsigned char *sk_buff_data_t;
402 * struct skb_mstamp - multi resolution time stamps
403 * @stamp_us: timestamp in us resolution
404 * @stamp_jiffies: timestamp in jiffies
417 * skb_mstamp_get - get current timestamp
418 * @cl: place to store timestamps
420 static inline void skb_mstamp_get(struct skb_mstamp *cl)
422 u64 val = local_clock();
424 do_div(val, NSEC_PER_USEC);
425 cl->stamp_us = (u32)val;
426 cl->stamp_jiffies = (u32)jiffies;
430 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
431 * @t1: pointer to newest sample
432 * @t0: pointer to oldest sample
434 static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1,
435 const struct skb_mstamp *t0)
437 s32 delta_us = t1->stamp_us - t0->stamp_us;
438 u32 delta_jiffies = t1->stamp_jiffies - t0->stamp_jiffies;
440 /* If delta_us is negative, this might be because interval is too big,
441 * or local_clock() drift is too big : fallback using jiffies.
444 delta_jiffies >= (INT_MAX / (USEC_PER_SEC / HZ)))
446 delta_us = jiffies_to_usecs(delta_jiffies);
453 * struct sk_buff - socket buffer
454 * @next: Next buffer in list
455 * @prev: Previous buffer in list
456 * @tstamp: Time we arrived/left
457 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
458 * @sk: Socket we are owned by
459 * @dev: Device we arrived on/are leaving by
460 * @cb: Control buffer. Free for use by every layer. Put private vars here
461 * @_skb_refdst: destination entry (with norefcount bit)
462 * @sp: the security path, used for xfrm
463 * @len: Length of actual data
464 * @data_len: Data length
465 * @mac_len: Length of link layer header
466 * @hdr_len: writable header length of cloned skb
467 * @csum: Checksum (must include start/offset pair)
468 * @csum_start: Offset from skb->head where checksumming should start
469 * @csum_offset: Offset from csum_start where checksum should be stored
470 * @priority: Packet queueing priority
471 * @ignore_df: allow local fragmentation
472 * @cloned: Head may be cloned (check refcnt to be sure)
473 * @ip_summed: Driver fed us an IP checksum
474 * @nohdr: Payload reference only, must not modify header
475 * @nfctinfo: Relationship of this skb to the connection
476 * @pkt_type: Packet class
477 * @fclone: skbuff clone status
478 * @ipvs_property: skbuff is owned by ipvs
479 * @peeked: this packet has been seen already, so stats have been
480 * done for it, don't do them again
481 * @nf_trace: netfilter packet trace flag
482 * @protocol: Packet protocol from driver
483 * @destructor: Destruct function
484 * @nfct: Associated connection, if any
485 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
486 * @skb_iif: ifindex of device we arrived on
487 * @tc_index: Traffic control index
488 * @tc_verd: traffic control verdict
489 * @hash: the packet hash
490 * @queue_mapping: Queue mapping for multiqueue devices
491 * @xmit_more: More SKBs are pending for this queue
492 * @ndisc_nodetype: router type (from link layer)
493 * @ooo_okay: allow the mapping of a socket to a queue to be changed
494 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
496 * @sw_hash: indicates hash was computed in software stack
497 * @wifi_acked_valid: wifi_acked was set
498 * @wifi_acked: whether frame was acked on wifi or not
499 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
500 * @napi_id: id of the NAPI struct this skb came from
501 * @secmark: security marking
502 * @mark: Generic packet mark
503 * @vlan_proto: vlan encapsulation protocol
504 * @vlan_tci: vlan tag control information
505 * @inner_protocol: Protocol (encapsulation)
506 * @inner_transport_header: Inner transport layer header (encapsulation)
507 * @inner_network_header: Network layer header (encapsulation)
508 * @inner_mac_header: Link layer header (encapsulation)
509 * @transport_header: Transport layer header
510 * @network_header: Network layer header
511 * @mac_header: Link layer header
512 * @tail: Tail pointer
514 * @head: Head of buffer
515 * @data: Data head pointer
516 * @truesize: Buffer size
517 * @users: User count - see {datagram,tcp}.c
523 /* These two members must be first. */
524 struct sk_buff *next;
525 struct sk_buff *prev;
529 struct skb_mstamp skb_mstamp;
532 struct rb_node rbnode; /* used in netem & tcp stack */
535 struct net_device *dev;
538 * This is the control buffer. It is free to use for every
539 * layer. Please put your private variables there. If you
540 * want to keep them across layers you have to do a skb_clone()
541 * first. This is owned by whoever has the skb queued ATM.
543 char cb[48] __aligned(8);
545 unsigned long _skb_refdst;
546 void (*destructor)(struct sk_buff *skb);
550 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
551 struct nf_conntrack *nfct;
553 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
554 struct nf_bridge_info *nf_bridge;
561 /* Following fields are _not_ copied in __copy_skb_header()
562 * Note that queue_mapping is here mostly to fill a hole.
564 kmemcheck_bitfield_begin(flags1);
573 kmemcheck_bitfield_end(flags1);
575 /* fields enclosed in headers_start/headers_end are copied
576 * using a single memcpy() in __copy_skb_header()
579 __u32 headers_start[0];
582 /* if you move pkt_type around you also must adapt those constants */
583 #ifdef __BIG_ENDIAN_BITFIELD
584 #define PKT_TYPE_MAX (7 << 5)
586 #define PKT_TYPE_MAX 7
588 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
590 __u8 __pkt_type_offset[0];
601 __u8 wifi_acked_valid:1;
605 /* Indicates the inner headers are valid in the skbuff. */
606 __u8 encapsulation:1;
607 __u8 encap_hdr_csum:1;
609 __u8 csum_complete_sw:1;
613 #ifdef CONFIG_IPV6_NDISC_NODETYPE
614 __u8 ndisc_nodetype:2;
616 __u8 ipvs_property:1;
617 __u8 inner_protocol_type:1;
618 __u8 remcsum_offload:1;
619 /* 3 or 5 bit hole */
621 #ifdef CONFIG_NET_SCHED
622 __u16 tc_index; /* traffic control index */
623 #ifdef CONFIG_NET_CLS_ACT
624 __u16 tc_verd; /* traffic control verdict */
640 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
642 unsigned int napi_id;
643 unsigned int sender_cpu;
646 #ifdef CONFIG_NETWORK_SECMARK
651 __u32 reserved_tailroom;
655 __be16 inner_protocol;
659 __u16 inner_transport_header;
660 __u16 inner_network_header;
661 __u16 inner_mac_header;
664 __u16 transport_header;
665 __u16 network_header;
669 __u32 headers_end[0];
672 /* These elements must be at the end, see alloc_skb() for details. */
677 unsigned int truesize;
683 * Handling routines are only of interest to the kernel
685 #include <linux/slab.h>
688 #define SKB_ALLOC_FCLONE 0x01
689 #define SKB_ALLOC_RX 0x02
690 #define SKB_ALLOC_NAPI 0x04
692 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
693 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
695 return unlikely(skb->pfmemalloc);
699 * skb might have a dst pointer attached, refcounted or not.
700 * _skb_refdst low order bit is set if refcount was _not_ taken
702 #define SKB_DST_NOREF 1UL
703 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
706 * skb_dst - returns skb dst_entry
709 * Returns skb dst_entry, regardless of reference taken or not.
711 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
713 /* If refdst was not refcounted, check we still are in a
714 * rcu_read_lock section
716 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
717 !rcu_read_lock_held() &&
718 !rcu_read_lock_bh_held());
719 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
723 * skb_dst_set - sets skb dst
727 * Sets skb dst, assuming a reference was taken on dst and should
728 * be released by skb_dst_drop()
730 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
732 skb->_skb_refdst = (unsigned long)dst;
736 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
740 * Sets skb dst, assuming a reference was not taken on dst.
741 * If dst entry is cached, we do not take reference and dst_release
742 * will be avoided by refdst_drop. If dst entry is not cached, we take
743 * reference, so that last dst_release can destroy the dst immediately.
745 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
747 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
748 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
752 * skb_dst_is_noref - Test if skb dst isn't refcounted
755 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
757 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
760 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
762 return (struct rtable *)skb_dst(skb);
765 void kfree_skb(struct sk_buff *skb);
766 void kfree_skb_list(struct sk_buff *segs);
767 void skb_tx_error(struct sk_buff *skb);
768 void consume_skb(struct sk_buff *skb);
769 void __kfree_skb(struct sk_buff *skb);
770 extern struct kmem_cache *skbuff_head_cache;
772 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
773 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
774 bool *fragstolen, int *delta_truesize);
776 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
778 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
779 struct sk_buff *build_skb(void *data, unsigned int frag_size);
780 static inline struct sk_buff *alloc_skb(unsigned int size,
783 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
786 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
787 unsigned long data_len,
792 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
793 struct sk_buff_fclones {
802 * skb_fclone_busy - check if fclone is busy
805 * Returns true is skb is a fast clone, and its clone is not freed.
806 * Some drivers call skb_orphan() in their ndo_start_xmit(),
807 * so we also check that this didnt happen.
809 static inline bool skb_fclone_busy(const struct sock *sk,
810 const struct sk_buff *skb)
812 const struct sk_buff_fclones *fclones;
814 fclones = container_of(skb, struct sk_buff_fclones, skb1);
816 return skb->fclone == SKB_FCLONE_ORIG &&
817 atomic_read(&fclones->fclone_ref) > 1 &&
818 fclones->skb2.sk == sk;
821 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
824 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
827 struct sk_buff *__alloc_skb_head(gfp_t priority, int node);
828 static inline struct sk_buff *alloc_skb_head(gfp_t priority)
830 return __alloc_skb_head(priority, -1);
833 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
834 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
835 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
836 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
837 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
838 gfp_t gfp_mask, bool fclone);
839 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
842 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
845 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
846 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
847 unsigned int headroom);
848 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
849 int newtailroom, gfp_t priority);
850 int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
851 int offset, int len);
852 int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
854 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
855 int skb_pad(struct sk_buff *skb, int pad);
856 #define dev_kfree_skb(a) consume_skb(a)
858 int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
859 int getfrag(void *from, char *to, int offset,
860 int len, int odd, struct sk_buff *skb),
861 void *from, int length);
863 struct skb_seq_state {
867 __u32 stepped_offset;
868 struct sk_buff *root_skb;
869 struct sk_buff *cur_skb;
873 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
874 unsigned int to, struct skb_seq_state *st);
875 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
876 struct skb_seq_state *st);
877 void skb_abort_seq_read(struct skb_seq_state *st);
879 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
880 unsigned int to, struct ts_config *config);
883 * Packet hash types specify the type of hash in skb_set_hash.
885 * Hash types refer to the protocol layer addresses which are used to
886 * construct a packet's hash. The hashes are used to differentiate or identify
887 * flows of the protocol layer for the hash type. Hash types are either
888 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
890 * Properties of hashes:
892 * 1) Two packets in different flows have different hash values
893 * 2) Two packets in the same flow should have the same hash value
895 * A hash at a higher layer is considered to be more specific. A driver should
896 * set the most specific hash possible.
898 * A driver cannot indicate a more specific hash than the layer at which a hash
899 * was computed. For instance an L3 hash cannot be set as an L4 hash.
901 * A driver may indicate a hash level which is less specific than the
902 * actual layer the hash was computed on. For instance, a hash computed
903 * at L4 may be considered an L3 hash. This should only be done if the
904 * driver can't unambiguously determine that the HW computed the hash at
905 * the higher layer. Note that the "should" in the second property above
908 enum pkt_hash_types {
909 PKT_HASH_TYPE_NONE, /* Undefined type */
910 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
911 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
912 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
916 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
918 skb->l4_hash = (type == PKT_HASH_TYPE_L4);
923 void __skb_get_hash(struct sk_buff *skb);
924 static inline __u32 skb_get_hash(struct sk_buff *skb)
926 if (!skb->l4_hash && !skb->sw_hash)
932 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
937 static inline void skb_clear_hash(struct sk_buff *skb)
944 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
950 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
952 to->hash = from->hash;
953 to->sw_hash = from->sw_hash;
954 to->l4_hash = from->l4_hash;
957 static inline void skb_sender_cpu_clear(struct sk_buff *skb)
964 #ifdef NET_SKBUFF_DATA_USES_OFFSET
965 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
967 return skb->head + skb->end;
970 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
975 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
980 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
982 return skb->end - skb->head;
987 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
989 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
991 return &skb_shinfo(skb)->hwtstamps;
995 * skb_queue_empty - check if a queue is empty
998 * Returns true if the queue is empty, false otherwise.
1000 static inline int skb_queue_empty(const struct sk_buff_head *list)
1002 return list->next == (const struct sk_buff *) list;
1006 * skb_queue_is_last - check if skb is the last entry in the queue
1010 * Returns true if @skb is the last buffer on the list.
1012 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1013 const struct sk_buff *skb)
1015 return skb->next == (const struct sk_buff *) list;
1019 * skb_queue_is_first - check if skb is the first entry in the queue
1023 * Returns true if @skb is the first buffer on the list.
1025 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1026 const struct sk_buff *skb)
1028 return skb->prev == (const struct sk_buff *) list;
1032 * skb_queue_next - return the next packet in the queue
1034 * @skb: current buffer
1036 * Return the next packet in @list after @skb. It is only valid to
1037 * call this if skb_queue_is_last() evaluates to false.
1039 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1040 const struct sk_buff *skb)
1042 /* This BUG_ON may seem severe, but if we just return then we
1043 * are going to dereference garbage.
1045 BUG_ON(skb_queue_is_last(list, skb));
1050 * skb_queue_prev - return the prev packet in the queue
1052 * @skb: current buffer
1054 * Return the prev packet in @list before @skb. It is only valid to
1055 * call this if skb_queue_is_first() evaluates to false.
1057 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1058 const struct sk_buff *skb)
1060 /* This BUG_ON may seem severe, but if we just return then we
1061 * are going to dereference garbage.
1063 BUG_ON(skb_queue_is_first(list, skb));
1068 * skb_get - reference buffer
1069 * @skb: buffer to reference
1071 * Makes another reference to a socket buffer and returns a pointer
1074 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1076 atomic_inc(&skb->users);
1081 * If users == 1, we are the only owner and are can avoid redundant
1086 * skb_cloned - is the buffer a clone
1087 * @skb: buffer to check
1089 * Returns true if the buffer was generated with skb_clone() and is
1090 * one of multiple shared copies of the buffer. Cloned buffers are
1091 * shared data so must not be written to under normal circumstances.
1093 static inline int skb_cloned(const struct sk_buff *skb)
1095 return skb->cloned &&
1096 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1099 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1101 might_sleep_if(pri & __GFP_WAIT);
1103 if (skb_cloned(skb))
1104 return pskb_expand_head(skb, 0, 0, pri);
1110 * skb_header_cloned - is the header a clone
1111 * @skb: buffer to check
1113 * Returns true if modifying the header part of the buffer requires
1114 * the data to be copied.
1116 static inline int skb_header_cloned(const struct sk_buff *skb)
1123 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1124 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1125 return dataref != 1;
1129 * skb_header_release - release reference to header
1130 * @skb: buffer to operate on
1132 * Drop a reference to the header part of the buffer. This is done
1133 * by acquiring a payload reference. You must not read from the header
1134 * part of skb->data after this.
1135 * Note : Check if you can use __skb_header_release() instead.
1137 static inline void skb_header_release(struct sk_buff *skb)
1141 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
1145 * __skb_header_release - release reference to header
1146 * @skb: buffer to operate on
1148 * Variant of skb_header_release() assuming skb is private to caller.
1149 * We can avoid one atomic operation.
1151 static inline void __skb_header_release(struct sk_buff *skb)
1154 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1159 * skb_shared - is the buffer shared
1160 * @skb: buffer to check
1162 * Returns true if more than one person has a reference to this
1165 static inline int skb_shared(const struct sk_buff *skb)
1167 return atomic_read(&skb->users) != 1;
1171 * skb_share_check - check if buffer is shared and if so clone it
1172 * @skb: buffer to check
1173 * @pri: priority for memory allocation
1175 * If the buffer is shared the buffer is cloned and the old copy
1176 * drops a reference. A new clone with a single reference is returned.
1177 * If the buffer is not shared the original buffer is returned. When
1178 * being called from interrupt status or with spinlocks held pri must
1181 * NULL is returned on a memory allocation failure.
1183 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1185 might_sleep_if(pri & __GFP_WAIT);
1186 if (skb_shared(skb)) {
1187 struct sk_buff *nskb = skb_clone(skb, pri);
1199 * Copy shared buffers into a new sk_buff. We effectively do COW on
1200 * packets to handle cases where we have a local reader and forward
1201 * and a couple of other messy ones. The normal one is tcpdumping
1202 * a packet thats being forwarded.
1206 * skb_unshare - make a copy of a shared buffer
1207 * @skb: buffer to check
1208 * @pri: priority for memory allocation
1210 * If the socket buffer is a clone then this function creates a new
1211 * copy of the data, drops a reference count on the old copy and returns
1212 * the new copy with the reference count at 1. If the buffer is not a clone
1213 * the original buffer is returned. When called with a spinlock held or
1214 * from interrupt state @pri must be %GFP_ATOMIC
1216 * %NULL is returned on a memory allocation failure.
1218 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1221 might_sleep_if(pri & __GFP_WAIT);
1222 if (skb_cloned(skb)) {
1223 struct sk_buff *nskb = skb_copy(skb, pri);
1225 /* Free our shared copy */
1236 * skb_peek - peek at the head of an &sk_buff_head
1237 * @list_: list to peek at
1239 * Peek an &sk_buff. Unlike most other operations you _MUST_
1240 * be careful with this one. A peek leaves the buffer on the
1241 * list and someone else may run off with it. You must hold
1242 * the appropriate locks or have a private queue to do this.
1244 * Returns %NULL for an empty list or a pointer to the head element.
1245 * The reference count is not incremented and the reference is therefore
1246 * volatile. Use with caution.
1248 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1250 struct sk_buff *skb = list_->next;
1252 if (skb == (struct sk_buff *)list_)
1258 * skb_peek_next - peek skb following the given one from a queue
1259 * @skb: skb to start from
1260 * @list_: list to peek at
1262 * Returns %NULL when the end of the list is met or a pointer to the
1263 * next element. The reference count is not incremented and the
1264 * reference is therefore volatile. Use with caution.
1266 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1267 const struct sk_buff_head *list_)
1269 struct sk_buff *next = skb->next;
1271 if (next == (struct sk_buff *)list_)
1277 * skb_peek_tail - peek at the tail of an &sk_buff_head
1278 * @list_: list to peek at
1280 * Peek an &sk_buff. Unlike most other operations you _MUST_
1281 * be careful with this one. A peek leaves the buffer on the
1282 * list and someone else may run off with it. You must hold
1283 * the appropriate locks or have a private queue to do this.
1285 * Returns %NULL for an empty list or a pointer to the tail element.
1286 * The reference count is not incremented and the reference is therefore
1287 * volatile. Use with caution.
1289 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1291 struct sk_buff *skb = list_->prev;
1293 if (skb == (struct sk_buff *)list_)
1300 * skb_queue_len - get queue length
1301 * @list_: list to measure
1303 * Return the length of an &sk_buff queue.
1305 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1311 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1312 * @list: queue to initialize
1314 * This initializes only the list and queue length aspects of
1315 * an sk_buff_head object. This allows to initialize the list
1316 * aspects of an sk_buff_head without reinitializing things like
1317 * the spinlock. It can also be used for on-stack sk_buff_head
1318 * objects where the spinlock is known to not be used.
1320 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1322 list->prev = list->next = (struct sk_buff *)list;
1327 * This function creates a split out lock class for each invocation;
1328 * this is needed for now since a whole lot of users of the skb-queue
1329 * infrastructure in drivers have different locking usage (in hardirq)
1330 * than the networking core (in softirq only). In the long run either the
1331 * network layer or drivers should need annotation to consolidate the
1332 * main types of usage into 3 classes.
1334 static inline void skb_queue_head_init(struct sk_buff_head *list)
1336 spin_lock_init(&list->lock);
1337 __skb_queue_head_init(list);
1340 static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
1342 raw_spin_lock_init(&list->raw_lock);
1343 __skb_queue_head_init(list);
1346 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1347 struct lock_class_key *class)
1349 skb_queue_head_init(list);
1350 lockdep_set_class(&list->lock, class);
1354 * Insert an sk_buff on a list.
1356 * The "__skb_xxxx()" functions are the non-atomic ones that
1357 * can only be called with interrupts disabled.
1359 void skb_insert(struct sk_buff *old, struct sk_buff *newsk,
1360 struct sk_buff_head *list);
1361 static inline void __skb_insert(struct sk_buff *newsk,
1362 struct sk_buff *prev, struct sk_buff *next,
1363 struct sk_buff_head *list)
1367 next->prev = prev->next = newsk;
1371 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1372 struct sk_buff *prev,
1373 struct sk_buff *next)
1375 struct sk_buff *first = list->next;
1376 struct sk_buff *last = list->prev;
1386 * skb_queue_splice - join two skb lists, this is designed for stacks
1387 * @list: the new list to add
1388 * @head: the place to add it in the first list
1390 static inline void skb_queue_splice(const struct sk_buff_head *list,
1391 struct sk_buff_head *head)
1393 if (!skb_queue_empty(list)) {
1394 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1395 head->qlen += list->qlen;
1400 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1401 * @list: the new list to add
1402 * @head: the place to add it in the first list
1404 * The list at @list is reinitialised
1406 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1407 struct sk_buff_head *head)
1409 if (!skb_queue_empty(list)) {
1410 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1411 head->qlen += list->qlen;
1412 __skb_queue_head_init(list);
1417 * skb_queue_splice_tail - join two skb lists, each list being a queue
1418 * @list: the new list to add
1419 * @head: the place to add it in the first list
1421 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1422 struct sk_buff_head *head)
1424 if (!skb_queue_empty(list)) {
1425 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1426 head->qlen += list->qlen;
1431 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1432 * @list: the new list to add
1433 * @head: the place to add it in the first list
1435 * Each of the lists is a queue.
1436 * The list at @list is reinitialised
1438 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1439 struct sk_buff_head *head)
1441 if (!skb_queue_empty(list)) {
1442 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1443 head->qlen += list->qlen;
1444 __skb_queue_head_init(list);
1449 * __skb_queue_after - queue a buffer at the list head
1450 * @list: list to use
1451 * @prev: place after this buffer
1452 * @newsk: buffer to queue
1454 * Queue a buffer int the middle of a list. This function takes no locks
1455 * and you must therefore hold required locks before calling it.
1457 * A buffer cannot be placed on two lists at the same time.
1459 static inline void __skb_queue_after(struct sk_buff_head *list,
1460 struct sk_buff *prev,
1461 struct sk_buff *newsk)
1463 __skb_insert(newsk, prev, prev->next, list);
1466 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1467 struct sk_buff_head *list);
1469 static inline void __skb_queue_before(struct sk_buff_head *list,
1470 struct sk_buff *next,
1471 struct sk_buff *newsk)
1473 __skb_insert(newsk, next->prev, next, list);
1477 * __skb_queue_head - queue a buffer at the list head
1478 * @list: list to use
1479 * @newsk: buffer to queue
1481 * Queue a buffer at the start of a list. This function takes no locks
1482 * and you must therefore hold required locks before calling it.
1484 * A buffer cannot be placed on two lists at the same time.
1486 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1487 static inline void __skb_queue_head(struct sk_buff_head *list,
1488 struct sk_buff *newsk)
1490 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1494 * __skb_queue_tail - queue a buffer at the list tail
1495 * @list: list to use
1496 * @newsk: buffer to queue
1498 * Queue a buffer at the end of a list. This function takes no locks
1499 * and you must therefore hold required locks before calling it.
1501 * A buffer cannot be placed on two lists at the same time.
1503 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1504 static inline void __skb_queue_tail(struct sk_buff_head *list,
1505 struct sk_buff *newsk)
1507 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1511 * remove sk_buff from list. _Must_ be called atomically, and with
1514 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1515 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1517 struct sk_buff *next, *prev;
1522 skb->next = skb->prev = NULL;
1528 * __skb_dequeue - remove from the head of the queue
1529 * @list: list to dequeue from
1531 * Remove the head of the list. This function does not take any locks
1532 * so must be used with appropriate locks held only. The head item is
1533 * returned or %NULL if the list is empty.
1535 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1536 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1538 struct sk_buff *skb = skb_peek(list);
1540 __skb_unlink(skb, list);
1545 * __skb_dequeue_tail - remove from the tail of the queue
1546 * @list: list to dequeue from
1548 * Remove the tail of the list. This function does not take any locks
1549 * so must be used with appropriate locks held only. The tail item is
1550 * returned or %NULL if the list is empty.
1552 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1553 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1555 struct sk_buff *skb = skb_peek_tail(list);
1557 __skb_unlink(skb, list);
1562 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1564 return skb->data_len;
1567 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1569 return skb->len - skb->data_len;
1572 static inline int skb_pagelen(const struct sk_buff *skb)
1576 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1577 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1578 return len + skb_headlen(skb);
1582 * __skb_fill_page_desc - initialise a paged fragment in an skb
1583 * @skb: buffer containing fragment to be initialised
1584 * @i: paged fragment index to initialise
1585 * @page: the page to use for this fragment
1586 * @off: the offset to the data with @page
1587 * @size: the length of the data
1589 * Initialises the @i'th fragment of @skb to point to &size bytes at
1590 * offset @off within @page.
1592 * Does not take any additional reference on the fragment.
1594 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1595 struct page *page, int off, int size)
1597 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1600 * Propagate page->pfmemalloc to the skb if we can. The problem is
1601 * that not all callers have unique ownership of the page. If
1602 * pfmemalloc is set, we check the mapping as a mapping implies
1603 * page->index is set (index and pfmemalloc share space).
1604 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1605 * do not lose pfmemalloc information as the pages would not be
1606 * allocated using __GFP_MEMALLOC.
1608 frag->page.p = page;
1609 frag->page_offset = off;
1610 skb_frag_size_set(frag, size);
1612 page = compound_head(page);
1613 if (page->pfmemalloc && !page->mapping)
1614 skb->pfmemalloc = true;
1618 * skb_fill_page_desc - initialise a paged fragment in an skb
1619 * @skb: buffer containing fragment to be initialised
1620 * @i: paged fragment index to initialise
1621 * @page: the page to use for this fragment
1622 * @off: the offset to the data with @page
1623 * @size: the length of the data
1625 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1626 * @skb to point to @size bytes at offset @off within @page. In
1627 * addition updates @skb such that @i is the last fragment.
1629 * Does not take any additional reference on the fragment.
1631 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1632 struct page *page, int off, int size)
1634 __skb_fill_page_desc(skb, i, page, off, size);
1635 skb_shinfo(skb)->nr_frags = i + 1;
1638 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
1639 int size, unsigned int truesize);
1641 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
1642 unsigned int truesize);
1644 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1645 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1646 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1648 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1649 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1651 return skb->head + skb->tail;
1654 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1656 skb->tail = skb->data - skb->head;
1659 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1661 skb_reset_tail_pointer(skb);
1662 skb->tail += offset;
1665 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1666 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1671 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1673 skb->tail = skb->data;
1676 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1678 skb->tail = skb->data + offset;
1681 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1684 * Add data to an sk_buff
1686 unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
1687 unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1688 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1690 unsigned char *tmp = skb_tail_pointer(skb);
1691 SKB_LINEAR_ASSERT(skb);
1697 unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1698 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1705 unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1706 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1709 BUG_ON(skb->len < skb->data_len);
1710 return skb->data += len;
1713 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1715 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1718 unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1720 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1722 if (len > skb_headlen(skb) &&
1723 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1726 return skb->data += len;
1729 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1731 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1734 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1736 if (likely(len <= skb_headlen(skb)))
1738 if (unlikely(len > skb->len))
1740 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1744 * skb_headroom - bytes at buffer head
1745 * @skb: buffer to check
1747 * Return the number of bytes of free space at the head of an &sk_buff.
1749 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1751 return skb->data - skb->head;
1755 * skb_tailroom - bytes at buffer end
1756 * @skb: buffer to check
1758 * Return the number of bytes of free space at the tail of an sk_buff
1760 static inline int skb_tailroom(const struct sk_buff *skb)
1762 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1766 * skb_availroom - bytes at buffer end
1767 * @skb: buffer to check
1769 * Return the number of bytes of free space at the tail of an sk_buff
1770 * allocated by sk_stream_alloc()
1772 static inline int skb_availroom(const struct sk_buff *skb)
1774 if (skb_is_nonlinear(skb))
1777 return skb->end - skb->tail - skb->reserved_tailroom;
1781 * skb_reserve - adjust headroom
1782 * @skb: buffer to alter
1783 * @len: bytes to move
1785 * Increase the headroom of an empty &sk_buff by reducing the tail
1786 * room. This is only allowed for an empty buffer.
1788 static inline void skb_reserve(struct sk_buff *skb, int len)
1794 #define ENCAP_TYPE_ETHER 0
1795 #define ENCAP_TYPE_IPPROTO 1
1797 static inline void skb_set_inner_protocol(struct sk_buff *skb,
1800 skb->inner_protocol = protocol;
1801 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
1804 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
1807 skb->inner_ipproto = ipproto;
1808 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
1811 static inline void skb_reset_inner_headers(struct sk_buff *skb)
1813 skb->inner_mac_header = skb->mac_header;
1814 skb->inner_network_header = skb->network_header;
1815 skb->inner_transport_header = skb->transport_header;
1818 static inline void skb_reset_mac_len(struct sk_buff *skb)
1820 skb->mac_len = skb->network_header - skb->mac_header;
1823 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1826 return skb->head + skb->inner_transport_header;
1829 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1831 skb->inner_transport_header = skb->data - skb->head;
1834 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1837 skb_reset_inner_transport_header(skb);
1838 skb->inner_transport_header += offset;
1841 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1843 return skb->head + skb->inner_network_header;
1846 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1848 skb->inner_network_header = skb->data - skb->head;
1851 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1854 skb_reset_inner_network_header(skb);
1855 skb->inner_network_header += offset;
1858 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1860 return skb->head + skb->inner_mac_header;
1863 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1865 skb->inner_mac_header = skb->data - skb->head;
1868 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1871 skb_reset_inner_mac_header(skb);
1872 skb->inner_mac_header += offset;
1874 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1876 return skb->transport_header != (typeof(skb->transport_header))~0U;
1879 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1881 return skb->head + skb->transport_header;
1884 static inline void skb_reset_transport_header(struct sk_buff *skb)
1886 skb->transport_header = skb->data - skb->head;
1889 static inline void skb_set_transport_header(struct sk_buff *skb,
1892 skb_reset_transport_header(skb);
1893 skb->transport_header += offset;
1896 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1898 return skb->head + skb->network_header;
1901 static inline void skb_reset_network_header(struct sk_buff *skb)
1903 skb->network_header = skb->data - skb->head;
1906 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1908 skb_reset_network_header(skb);
1909 skb->network_header += offset;
1912 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1914 return skb->head + skb->mac_header;
1917 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1919 return skb->mac_header != (typeof(skb->mac_header))~0U;
1922 static inline void skb_reset_mac_header(struct sk_buff *skb)
1924 skb->mac_header = skb->data - skb->head;
1927 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1929 skb_reset_mac_header(skb);
1930 skb->mac_header += offset;
1933 static inline void skb_pop_mac_header(struct sk_buff *skb)
1935 skb->mac_header = skb->network_header;
1938 static inline void skb_probe_transport_header(struct sk_buff *skb,
1939 const int offset_hint)
1941 struct flow_keys keys;
1943 if (skb_transport_header_was_set(skb))
1945 else if (skb_flow_dissect(skb, &keys))
1946 skb_set_transport_header(skb, keys.thoff);
1948 skb_set_transport_header(skb, offset_hint);
1951 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1953 if (skb_mac_header_was_set(skb)) {
1954 const unsigned char *old_mac = skb_mac_header(skb);
1956 skb_set_mac_header(skb, -skb->mac_len);
1957 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1961 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1963 return skb->csum_start - skb_headroom(skb);
1966 static inline int skb_transport_offset(const struct sk_buff *skb)
1968 return skb_transport_header(skb) - skb->data;
1971 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1973 return skb->transport_header - skb->network_header;
1976 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
1978 return skb->inner_transport_header - skb->inner_network_header;
1981 static inline int skb_network_offset(const struct sk_buff *skb)
1983 return skb_network_header(skb) - skb->data;
1986 static inline int skb_inner_network_offset(const struct sk_buff *skb)
1988 return skb_inner_network_header(skb) - skb->data;
1991 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1993 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1997 * CPUs often take a performance hit when accessing unaligned memory
1998 * locations. The actual performance hit varies, it can be small if the
1999 * hardware handles it or large if we have to take an exception and fix it
2002 * Since an ethernet header is 14 bytes network drivers often end up with
2003 * the IP header at an unaligned offset. The IP header can be aligned by
2004 * shifting the start of the packet by 2 bytes. Drivers should do this
2007 * skb_reserve(skb, NET_IP_ALIGN);
2009 * The downside to this alignment of the IP header is that the DMA is now
2010 * unaligned. On some architectures the cost of an unaligned DMA is high
2011 * and this cost outweighs the gains made by aligning the IP header.
2013 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2016 #ifndef NET_IP_ALIGN
2017 #define NET_IP_ALIGN 2
2021 * The networking layer reserves some headroom in skb data (via
2022 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2023 * the header has to grow. In the default case, if the header has to grow
2024 * 32 bytes or less we avoid the reallocation.
2026 * Unfortunately this headroom changes the DMA alignment of the resulting
2027 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2028 * on some architectures. An architecture can override this value,
2029 * perhaps setting it to a cacheline in size (since that will maintain
2030 * cacheline alignment of the DMA). It must be a power of 2.
2032 * Various parts of the networking layer expect at least 32 bytes of
2033 * headroom, you should not reduce this.
2035 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2036 * to reduce average number of cache lines per packet.
2037 * get_rps_cpus() for example only access one 64 bytes aligned block :
2038 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2041 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2044 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
2046 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
2048 if (unlikely(skb_is_nonlinear(skb))) {
2053 skb_set_tail_pointer(skb, len);
2056 void skb_trim(struct sk_buff *skb, unsigned int len);
2058 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
2061 return ___pskb_trim(skb, len);
2062 __skb_trim(skb, len);
2066 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
2068 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
2072 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2073 * @skb: buffer to alter
2076 * This is identical to pskb_trim except that the caller knows that
2077 * the skb is not cloned so we should never get an error due to out-
2080 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
2082 int err = pskb_trim(skb, len);
2087 * skb_orphan - orphan a buffer
2088 * @skb: buffer to orphan
2090 * If a buffer currently has an owner then we call the owner's
2091 * destructor function and make the @skb unowned. The buffer continues
2092 * to exist but is no longer charged to its former owner.
2094 static inline void skb_orphan(struct sk_buff *skb)
2096 if (skb->destructor) {
2097 skb->destructor(skb);
2098 skb->destructor = NULL;
2106 * skb_orphan_frags - orphan the frags contained in a buffer
2107 * @skb: buffer to orphan frags from
2108 * @gfp_mask: allocation mask for replacement pages
2110 * For each frag in the SKB which needs a destructor (i.e. has an
2111 * owner) create a copy of that frag and release the original
2112 * page by calling the destructor.
2114 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2116 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
2118 return skb_copy_ubufs(skb, gfp_mask);
2122 * __skb_queue_purge - empty a list
2123 * @list: list to empty
2125 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2126 * the list and one reference dropped. This function does not take the
2127 * list lock and the caller must hold the relevant locks to use it.
2129 void skb_queue_purge(struct sk_buff_head *list);
2130 static inline void __skb_queue_purge(struct sk_buff_head *list)
2132 struct sk_buff *skb;
2133 while ((skb = __skb_dequeue(list)) != NULL)
2137 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2138 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2139 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2141 void *netdev_alloc_frag(unsigned int fragsz);
2143 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2147 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2148 * @dev: network device to receive on
2149 * @length: length to allocate
2151 * Allocate a new &sk_buff and assign it a usage count of one. The
2152 * buffer has unspecified headroom built in. Users should allocate
2153 * the headroom they think they need without accounting for the
2154 * built in space. The built in space is used for optimisations.
2156 * %NULL is returned if there is no free memory. Although this function
2157 * allocates memory it can be called from an interrupt.
2159 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2160 unsigned int length)
2162 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2165 /* legacy helper around __netdev_alloc_skb() */
2166 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2169 return __netdev_alloc_skb(NULL, length, gfp_mask);
2172 /* legacy helper around netdev_alloc_skb() */
2173 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2175 return netdev_alloc_skb(NULL, length);
2179 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2180 unsigned int length, gfp_t gfp)
2182 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2184 if (NET_IP_ALIGN && skb)
2185 skb_reserve(skb, NET_IP_ALIGN);
2189 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2190 unsigned int length)
2192 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2195 void *napi_alloc_frag(unsigned int fragsz);
2196 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
2197 unsigned int length, gfp_t gfp_mask);
2198 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
2199 unsigned int length)
2201 return __napi_alloc_skb(napi, length, GFP_ATOMIC);
2205 * __dev_alloc_pages - allocate page for network Rx
2206 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2207 * @order: size of the allocation
2209 * Allocate a new page.
2211 * %NULL is returned if there is no free memory.
2213 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
2216 /* This piece of code contains several assumptions.
2217 * 1. This is for device Rx, therefor a cold page is preferred.
2218 * 2. The expectation is the user wants a compound page.
2219 * 3. If requesting a order 0 page it will not be compound
2220 * due to the check to see if order has a value in prep_new_page
2221 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2222 * code in gfp_to_alloc_flags that should be enforcing this.
2224 gfp_mask |= __GFP_COLD | __GFP_COMP | __GFP_MEMALLOC;
2226 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2229 static inline struct page *dev_alloc_pages(unsigned int order)
2231 return __dev_alloc_pages(GFP_ATOMIC, order);
2235 * __dev_alloc_page - allocate a page for network Rx
2236 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2238 * Allocate a new page.
2240 * %NULL is returned if there is no free memory.
2242 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
2244 return __dev_alloc_pages(gfp_mask, 0);
2247 static inline struct page *dev_alloc_page(void)
2249 return __dev_alloc_page(GFP_ATOMIC);
2253 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2254 * @page: The page that was allocated from skb_alloc_page
2255 * @skb: The skb that may need pfmemalloc set
2257 static inline void skb_propagate_pfmemalloc(struct page *page,
2258 struct sk_buff *skb)
2260 if (page && page->pfmemalloc)
2261 skb->pfmemalloc = true;
2265 * skb_frag_page - retrieve the page referred to by a paged fragment
2266 * @frag: the paged fragment
2268 * Returns the &struct page associated with @frag.
2270 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2272 return frag->page.p;
2276 * __skb_frag_ref - take an addition reference on a paged fragment.
2277 * @frag: the paged fragment
2279 * Takes an additional reference on the paged fragment @frag.
2281 static inline void __skb_frag_ref(skb_frag_t *frag)
2283 get_page(skb_frag_page(frag));
2287 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2289 * @f: the fragment offset.
2291 * Takes an additional reference on the @f'th paged fragment of @skb.
2293 static inline void skb_frag_ref(struct sk_buff *skb, int f)
2295 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
2299 * __skb_frag_unref - release a reference on a paged fragment.
2300 * @frag: the paged fragment
2302 * Releases a reference on the paged fragment @frag.
2304 static inline void __skb_frag_unref(skb_frag_t *frag)
2306 put_page(skb_frag_page(frag));
2310 * skb_frag_unref - release a reference on a paged fragment of an skb.
2312 * @f: the fragment offset
2314 * Releases a reference on the @f'th paged fragment of @skb.
2316 static inline void skb_frag_unref(struct sk_buff *skb, int f)
2318 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
2322 * skb_frag_address - gets the address of the data contained in a paged fragment
2323 * @frag: the paged fragment buffer
2325 * Returns the address of the data within @frag. The page must already
2328 static inline void *skb_frag_address(const skb_frag_t *frag)
2330 return page_address(skb_frag_page(frag)) + frag->page_offset;
2334 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2335 * @frag: the paged fragment buffer
2337 * Returns the address of the data within @frag. Checks that the page
2338 * is mapped and returns %NULL otherwise.
2340 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
2342 void *ptr = page_address(skb_frag_page(frag));
2346 return ptr + frag->page_offset;
2350 * __skb_frag_set_page - sets the page contained in a paged fragment
2351 * @frag: the paged fragment
2352 * @page: the page to set
2354 * Sets the fragment @frag to contain @page.
2356 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
2358 frag->page.p = page;
2362 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2364 * @f: the fragment offset
2365 * @page: the page to set
2367 * Sets the @f'th fragment of @skb to contain @page.
2369 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
2372 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
2375 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
2378 * skb_frag_dma_map - maps a paged fragment via the DMA API
2379 * @dev: the device to map the fragment to
2380 * @frag: the paged fragment to map
2381 * @offset: the offset within the fragment (starting at the
2382 * fragment's own offset)
2383 * @size: the number of bytes to map
2384 * @dir: the direction of the mapping (%PCI_DMA_*)
2386 * Maps the page associated with @frag to @device.
2388 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
2389 const skb_frag_t *frag,
2390 size_t offset, size_t size,
2391 enum dma_data_direction dir)
2393 return dma_map_page(dev, skb_frag_page(frag),
2394 frag->page_offset + offset, size, dir);
2397 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
2400 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
2404 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
2407 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
2412 * skb_clone_writable - is the header of a clone writable
2413 * @skb: buffer to check
2414 * @len: length up to which to write
2416 * Returns true if modifying the header part of the cloned buffer
2417 * does not requires the data to be copied.
2419 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
2421 return !skb_header_cloned(skb) &&
2422 skb_headroom(skb) + len <= skb->hdr_len;
2425 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
2430 if (headroom > skb_headroom(skb))
2431 delta = headroom - skb_headroom(skb);
2433 if (delta || cloned)
2434 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2440 * skb_cow - copy header of skb when it is required
2441 * @skb: buffer to cow
2442 * @headroom: needed headroom
2444 * If the skb passed lacks sufficient headroom or its data part
2445 * is shared, data is reallocated. If reallocation fails, an error
2446 * is returned and original skb is not changed.
2448 * The result is skb with writable area skb->head...skb->tail
2449 * and at least @headroom of space at head.
2451 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2453 return __skb_cow(skb, headroom, skb_cloned(skb));
2457 * skb_cow_head - skb_cow but only making the head writable
2458 * @skb: buffer to cow
2459 * @headroom: needed headroom
2461 * This function is identical to skb_cow except that we replace the
2462 * skb_cloned check by skb_header_cloned. It should be used when
2463 * you only need to push on some header and do not need to modify
2466 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2468 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2472 * skb_padto - pad an skbuff up to a minimal size
2473 * @skb: buffer to pad
2474 * @len: minimal length
2476 * Pads up a buffer to ensure the trailing bytes exist and are
2477 * blanked. If the buffer already contains sufficient data it
2478 * is untouched. Otherwise it is extended. Returns zero on
2479 * success. The skb is freed on error.
2481 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2483 unsigned int size = skb->len;
2484 if (likely(size >= len))
2486 return skb_pad(skb, len - size);
2490 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2491 * @skb: buffer to pad
2492 * @len: minimal length
2494 * Pads up a buffer to ensure the trailing bytes exist and are
2495 * blanked. If the buffer already contains sufficient data it
2496 * is untouched. Otherwise it is extended. Returns zero on
2497 * success. The skb is freed on error.
2499 static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
2501 unsigned int size = skb->len;
2503 if (unlikely(size < len)) {
2505 if (skb_pad(skb, len))
2507 __skb_put(skb, len);
2512 static inline int skb_add_data(struct sk_buff *skb,
2513 struct iov_iter *from, int copy)
2515 const int off = skb->len;
2517 if (skb->ip_summed == CHECKSUM_NONE) {
2519 if (csum_and_copy_from_iter(skb_put(skb, copy), copy,
2520 &csum, from) == copy) {
2521 skb->csum = csum_block_add(skb->csum, csum, off);
2524 } else if (copy_from_iter(skb_put(skb, copy), copy, from) == copy)
2527 __skb_trim(skb, off);
2531 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2532 const struct page *page, int off)
2535 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2537 return page == skb_frag_page(frag) &&
2538 off == frag->page_offset + skb_frag_size(frag);
2543 static inline int __skb_linearize(struct sk_buff *skb)
2545 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2549 * skb_linearize - convert paged skb to linear one
2550 * @skb: buffer to linarize
2552 * If there is no free memory -ENOMEM is returned, otherwise zero
2553 * is returned and the old skb data released.
2555 static inline int skb_linearize(struct sk_buff *skb)
2557 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2561 * skb_has_shared_frag - can any frag be overwritten
2562 * @skb: buffer to test
2564 * Return true if the skb has at least one frag that might be modified
2565 * by an external entity (as in vmsplice()/sendfile())
2567 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
2569 return skb_is_nonlinear(skb) &&
2570 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
2574 * skb_linearize_cow - make sure skb is linear and writable
2575 * @skb: buffer to process
2577 * If there is no free memory -ENOMEM is returned, otherwise zero
2578 * is returned and the old skb data released.
2580 static inline int skb_linearize_cow(struct sk_buff *skb)
2582 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2583 __skb_linearize(skb) : 0;
2587 * skb_postpull_rcsum - update checksum for received skb after pull
2588 * @skb: buffer to update
2589 * @start: start of data before pull
2590 * @len: length of data pulled
2592 * After doing a pull on a received packet, you need to call this to
2593 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2594 * CHECKSUM_NONE so that it can be recomputed from scratch.
2597 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2598 const void *start, unsigned int len)
2600 if (skb->ip_summed == CHECKSUM_COMPLETE)
2601 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2604 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2607 * pskb_trim_rcsum - trim received skb and update checksum
2608 * @skb: buffer to trim
2611 * This is exactly the same as pskb_trim except that it ensures the
2612 * checksum of received packets are still valid after the operation.
2615 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2617 if (likely(len >= skb->len))
2619 if (skb->ip_summed == CHECKSUM_COMPLETE)
2620 skb->ip_summed = CHECKSUM_NONE;
2621 return __pskb_trim(skb, len);
2624 #define skb_queue_walk(queue, skb) \
2625 for (skb = (queue)->next; \
2626 skb != (struct sk_buff *)(queue); \
2629 #define skb_queue_walk_safe(queue, skb, tmp) \
2630 for (skb = (queue)->next, tmp = skb->next; \
2631 skb != (struct sk_buff *)(queue); \
2632 skb = tmp, tmp = skb->next)
2634 #define skb_queue_walk_from(queue, skb) \
2635 for (; skb != (struct sk_buff *)(queue); \
2638 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2639 for (tmp = skb->next; \
2640 skb != (struct sk_buff *)(queue); \
2641 skb = tmp, tmp = skb->next)
2643 #define skb_queue_reverse_walk(queue, skb) \
2644 for (skb = (queue)->prev; \
2645 skb != (struct sk_buff *)(queue); \
2648 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2649 for (skb = (queue)->prev, tmp = skb->prev; \
2650 skb != (struct sk_buff *)(queue); \
2651 skb = tmp, tmp = skb->prev)
2653 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2654 for (tmp = skb->prev; \
2655 skb != (struct sk_buff *)(queue); \
2656 skb = tmp, tmp = skb->prev)
2658 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2660 return skb_shinfo(skb)->frag_list != NULL;
2663 static inline void skb_frag_list_init(struct sk_buff *skb)
2665 skb_shinfo(skb)->frag_list = NULL;
2668 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2670 frag->next = skb_shinfo(skb)->frag_list;
2671 skb_shinfo(skb)->frag_list = frag;
2674 #define skb_walk_frags(skb, iter) \
2675 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2677 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2678 int *peeked, int *off, int *err);
2679 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
2681 unsigned int datagram_poll(struct file *file, struct socket *sock,
2682 struct poll_table_struct *wait);
2683 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
2684 struct iov_iter *to, int size);
2685 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
2686 struct msghdr *msg, int size)
2688 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
2690 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
2691 struct msghdr *msg);
2692 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
2693 struct iov_iter *from, int len);
2694 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
2695 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2696 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
2697 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
2698 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
2699 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
2700 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
2701 int len, __wsum csum);
2702 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
2703 struct pipe_inode_info *pipe, unsigned int len,
2704 unsigned int flags);
2705 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2706 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
2707 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
2709 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
2710 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
2711 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
2712 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
2713 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
2714 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
2715 int skb_ensure_writable(struct sk_buff *skb, int write_len);
2716 int skb_vlan_pop(struct sk_buff *skb);
2717 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
2719 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
2721 return copy_from_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
2724 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
2726 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
2729 struct skb_checksum_ops {
2730 __wsum (*update)(const void *mem, int len, __wsum wsum);
2731 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
2734 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
2735 __wsum csum, const struct skb_checksum_ops *ops);
2736 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
2739 static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
2740 int len, void *data, int hlen, void *buffer)
2742 if (hlen - offset >= len)
2743 return data + offset;
2746 skb_copy_bits(skb, offset, buffer, len) < 0)
2752 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2753 int len, void *buffer)
2755 return __skb_header_pointer(skb, offset, len, skb->data,
2756 skb_headlen(skb), buffer);
2760 * skb_needs_linearize - check if we need to linearize a given skb
2761 * depending on the given device features.
2762 * @skb: socket buffer to check
2763 * @features: net device features
2765 * Returns true if either:
2766 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2767 * 2. skb is fragmented and the device does not support SG.
2769 static inline bool skb_needs_linearize(struct sk_buff *skb,
2770 netdev_features_t features)
2772 return skb_is_nonlinear(skb) &&
2773 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
2774 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
2777 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2779 const unsigned int len)
2781 memcpy(to, skb->data, len);
2784 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2785 const int offset, void *to,
2786 const unsigned int len)
2788 memcpy(to, skb->data + offset, len);
2791 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2793 const unsigned int len)
2795 memcpy(skb->data, from, len);
2798 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2801 const unsigned int len)
2803 memcpy(skb->data + offset, from, len);
2806 void skb_init(void);
2808 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2814 * skb_get_timestamp - get timestamp from a skb
2815 * @skb: skb to get stamp from
2816 * @stamp: pointer to struct timeval to store stamp in
2818 * Timestamps are stored in the skb as offsets to a base timestamp.
2819 * This function converts the offset back to a struct timeval and stores
2822 static inline void skb_get_timestamp(const struct sk_buff *skb,
2823 struct timeval *stamp)
2825 *stamp = ktime_to_timeval(skb->tstamp);
2828 static inline void skb_get_timestampns(const struct sk_buff *skb,
2829 struct timespec *stamp)
2831 *stamp = ktime_to_timespec(skb->tstamp);
2834 static inline void __net_timestamp(struct sk_buff *skb)
2836 skb->tstamp = ktime_get_real();
2839 static inline ktime_t net_timedelta(ktime_t t)
2841 return ktime_sub(ktime_get_real(), t);
2844 static inline ktime_t net_invalid_timestamp(void)
2846 return ktime_set(0, 0);
2849 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
2851 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2853 void skb_clone_tx_timestamp(struct sk_buff *skb);
2854 bool skb_defer_rx_timestamp(struct sk_buff *skb);
2856 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2858 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2862 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2867 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2870 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2872 * PHY drivers may accept clones of transmitted packets for
2873 * timestamping via their phy_driver.txtstamp method. These drivers
2874 * must call this function to return the skb back to the stack, with
2875 * or without a timestamp.
2877 * @skb: clone of the the original outgoing packet
2878 * @hwtstamps: hardware time stamps, may be NULL if not available
2881 void skb_complete_tx_timestamp(struct sk_buff *skb,
2882 struct skb_shared_hwtstamps *hwtstamps);
2884 void __skb_tstamp_tx(struct sk_buff *orig_skb,
2885 struct skb_shared_hwtstamps *hwtstamps,
2886 struct sock *sk, int tstype);
2889 * skb_tstamp_tx - queue clone of skb with send time stamps
2890 * @orig_skb: the original outgoing packet
2891 * @hwtstamps: hardware time stamps, may be NULL if not available
2893 * If the skb has a socket associated, then this function clones the
2894 * skb (thus sharing the actual data and optional structures), stores
2895 * the optional hardware time stamping information (if non NULL) or
2896 * generates a software time stamp (otherwise), then queues the clone
2897 * to the error queue of the socket. Errors are silently ignored.
2899 void skb_tstamp_tx(struct sk_buff *orig_skb,
2900 struct skb_shared_hwtstamps *hwtstamps);
2902 static inline void sw_tx_timestamp(struct sk_buff *skb)
2904 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2905 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2906 skb_tstamp_tx(skb, NULL);
2910 * skb_tx_timestamp() - Driver hook for transmit timestamping
2912 * Ethernet MAC Drivers should call this function in their hard_xmit()
2913 * function immediately before giving the sk_buff to the MAC hardware.
2915 * Specifically, one should make absolutely sure that this function is
2916 * called before TX completion of this packet can trigger. Otherwise
2917 * the packet could potentially already be freed.
2919 * @skb: A socket buffer.
2921 static inline void skb_tx_timestamp(struct sk_buff *skb)
2923 skb_clone_tx_timestamp(skb);
2924 sw_tx_timestamp(skb);
2928 * skb_complete_wifi_ack - deliver skb with wifi status
2930 * @skb: the original outgoing packet
2931 * @acked: ack status
2934 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2936 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2937 __sum16 __skb_checksum_complete(struct sk_buff *skb);
2939 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2941 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
2943 (skb->ip_summed == CHECKSUM_PARTIAL &&
2944 skb_checksum_start_offset(skb) >= 0));
2948 * skb_checksum_complete - Calculate checksum of an entire packet
2949 * @skb: packet to process
2951 * This function calculates the checksum over the entire packet plus
2952 * the value of skb->csum. The latter can be used to supply the
2953 * checksum of a pseudo header as used by TCP/UDP. It returns the
2956 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2957 * this function can be used to verify that checksum on received
2958 * packets. In that case the function should return zero if the
2959 * checksum is correct. In particular, this function will return zero
2960 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2961 * hardware has already verified the correctness of the checksum.
2963 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2965 return skb_csum_unnecessary(skb) ?
2966 0 : __skb_checksum_complete(skb);
2969 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
2971 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2972 if (skb->csum_level == 0)
2973 skb->ip_summed = CHECKSUM_NONE;
2979 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
2981 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2982 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
2984 } else if (skb->ip_summed == CHECKSUM_NONE) {
2985 skb->ip_summed = CHECKSUM_UNNECESSARY;
2986 skb->csum_level = 0;
2990 static inline void __skb_mark_checksum_bad(struct sk_buff *skb)
2992 /* Mark current checksum as bad (typically called from GRO
2993 * path). In the case that ip_summed is CHECKSUM_NONE
2994 * this must be the first checksum encountered in the packet.
2995 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
2996 * checksum after the last one validated. For UDP, a zero
2997 * checksum can not be marked as bad.
3000 if (skb->ip_summed == CHECKSUM_NONE ||
3001 skb->ip_summed == CHECKSUM_UNNECESSARY)
3005 /* Check if we need to perform checksum complete validation.
3007 * Returns true if checksum complete is needed, false otherwise
3008 * (either checksum is unnecessary or zero checksum is allowed).
3010 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
3014 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
3015 skb->csum_valid = 1;
3016 __skb_decr_checksum_unnecessary(skb);
3023 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3026 #define CHECKSUM_BREAK 76
3028 /* Unset checksum-complete
3030 * Unset checksum complete can be done when packet is being modified
3031 * (uncompressed for instance) and checksum-complete value is
3034 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
3036 if (skb->ip_summed == CHECKSUM_COMPLETE)
3037 skb->ip_summed = CHECKSUM_NONE;
3040 /* Validate (init) checksum based on checksum complete.
3043 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3044 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3045 * checksum is stored in skb->csum for use in __skb_checksum_complete
3046 * non-zero: value of invalid checksum
3049 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
3053 if (skb->ip_summed == CHECKSUM_COMPLETE) {
3054 if (!csum_fold(csum_add(psum, skb->csum))) {
3055 skb->csum_valid = 1;
3058 } else if (skb->csum_bad) {
3059 /* ip_summed == CHECKSUM_NONE in this case */
3065 if (complete || skb->len <= CHECKSUM_BREAK) {
3068 csum = __skb_checksum_complete(skb);
3069 skb->csum_valid = !csum;
3076 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
3081 /* Perform checksum validate (init). Note that this is a macro since we only
3082 * want to calculate the pseudo header which is an input function if necessary.
3083 * First we try to validate without any computation (checksum unnecessary) and
3084 * then calculate based on checksum complete calling the function to compute
3088 * 0: checksum is validated or try to in skb_checksum_complete
3089 * non-zero: value of invalid checksum
3091 #define __skb_checksum_validate(skb, proto, complete, \
3092 zero_okay, check, compute_pseudo) \
3094 __sum16 __ret = 0; \
3095 skb->csum_valid = 0; \
3096 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3097 __ret = __skb_checksum_validate_complete(skb, \
3098 complete, compute_pseudo(skb, proto)); \
3102 #define skb_checksum_init(skb, proto, compute_pseudo) \
3103 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3105 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3106 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3108 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3109 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3111 #define skb_checksum_validate_zero_check(skb, proto, check, \
3113 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3115 #define skb_checksum_simple_validate(skb) \
3116 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3118 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
3120 return (skb->ip_summed == CHECKSUM_NONE &&
3121 skb->csum_valid && !skb->csum_bad);
3124 static inline void __skb_checksum_convert(struct sk_buff *skb,
3125 __sum16 check, __wsum pseudo)
3127 skb->csum = ~pseudo;
3128 skb->ip_summed = CHECKSUM_COMPLETE;
3131 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3133 if (__skb_checksum_convert_check(skb)) \
3134 __skb_checksum_convert(skb, check, \
3135 compute_pseudo(skb, proto)); \
3138 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
3139 u16 start, u16 offset)
3141 skb->ip_summed = CHECKSUM_PARTIAL;
3142 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
3143 skb->csum_offset = offset - start;
3146 /* Update skbuf and packet to reflect the remote checksum offload operation.
3147 * When called, ptr indicates the starting point for skb->csum when
3148 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3149 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3151 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
3152 int start, int offset, bool nopartial)
3157 skb_remcsum_adjust_partial(skb, ptr, start, offset);
3161 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
3162 __skb_checksum_complete(skb);
3163 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
3166 delta = remcsum_adjust(ptr, skb->csum, start, offset);
3168 /* Adjust skb->csum since we changed the packet */
3169 skb->csum = csum_add(skb->csum, delta);
3172 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3173 void nf_conntrack_destroy(struct nf_conntrack *nfct);
3174 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
3176 if (nfct && atomic_dec_and_test(&nfct->use))
3177 nf_conntrack_destroy(nfct);
3179 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
3182 atomic_inc(&nfct->use);
3185 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3186 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
3188 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
3191 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
3194 atomic_inc(&nf_bridge->use);
3196 #endif /* CONFIG_BRIDGE_NETFILTER */
3197 static inline void nf_reset(struct sk_buff *skb)
3199 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3200 nf_conntrack_put(skb->nfct);
3203 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3204 nf_bridge_put(skb->nf_bridge);
3205 skb->nf_bridge = NULL;
3209 static inline void nf_reset_trace(struct sk_buff *skb)
3211 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3216 /* Note: This doesn't put any conntrack and bridge info in dst. */
3217 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
3220 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3221 dst->nfct = src->nfct;
3222 nf_conntrack_get(src->nfct);
3224 dst->nfctinfo = src->nfctinfo;
3226 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3227 dst->nf_bridge = src->nf_bridge;
3228 nf_bridge_get(src->nf_bridge);
3230 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3232 dst->nf_trace = src->nf_trace;
3236 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
3238 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3239 nf_conntrack_put(dst->nfct);
3241 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3242 nf_bridge_put(dst->nf_bridge);
3244 __nf_copy(dst, src, true);
3247 #ifdef CONFIG_NETWORK_SECMARK
3248 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3250 to->secmark = from->secmark;
3253 static inline void skb_init_secmark(struct sk_buff *skb)
3258 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3261 static inline void skb_init_secmark(struct sk_buff *skb)
3265 static inline bool skb_irq_freeable(const struct sk_buff *skb)
3267 return !skb->destructor &&
3268 #if IS_ENABLED(CONFIG_XFRM)
3271 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3274 !skb->_skb_refdst &&
3275 !skb_has_frag_list(skb);
3278 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
3280 skb->queue_mapping = queue_mapping;
3283 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
3285 return skb->queue_mapping;
3288 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
3290 to->queue_mapping = from->queue_mapping;
3293 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
3295 skb->queue_mapping = rx_queue + 1;
3298 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
3300 return skb->queue_mapping - 1;
3303 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
3305 return skb->queue_mapping != 0;
3308 u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
3309 unsigned int num_tx_queues);
3311 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
3320 /* Keeps track of mac header offset relative to skb->head.
3321 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3322 * For non-tunnel skb it points to skb_mac_header() and for
3323 * tunnel skb it points to outer mac header.
3324 * Keeps track of level of encapsulation of network headers.
3331 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3333 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
3335 return (skb_mac_header(inner_skb) - inner_skb->head) -
3336 SKB_GSO_CB(inner_skb)->mac_offset;
3339 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
3341 int new_headroom, headroom;
3344 headroom = skb_headroom(skb);
3345 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
3349 new_headroom = skb_headroom(skb);
3350 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
3354 /* Compute the checksum for a gso segment. First compute the checksum value
3355 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3356 * then add in skb->csum (checksum from csum_start to end of packet).
3357 * skb->csum and csum_start are then updated to reflect the checksum of the
3358 * resultant packet starting from the transport header-- the resultant checksum
3359 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3362 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
3364 int plen = SKB_GSO_CB(skb)->csum_start - skb_headroom(skb) -
3365 skb_transport_offset(skb);
3368 csum = csum_fold(csum_partial(skb_transport_header(skb),
3371 SKB_GSO_CB(skb)->csum_start -= plen;
3376 static inline bool skb_is_gso(const struct sk_buff *skb)
3378 return skb_shinfo(skb)->gso_size;
3381 /* Note: Should be called only if skb_is_gso(skb) is true */
3382 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
3384 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
3387 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
3389 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
3391 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3392 * wanted then gso_type will be set. */
3393 const struct skb_shared_info *shinfo = skb_shinfo(skb);
3395 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
3396 unlikely(shinfo->gso_type == 0)) {
3397 __skb_warn_lro_forwarding(skb);
3403 static inline void skb_forward_csum(struct sk_buff *skb)
3405 /* Unfortunately we don't support this one. Any brave souls? */
3406 if (skb->ip_summed == CHECKSUM_COMPLETE)
3407 skb->ip_summed = CHECKSUM_NONE;
3411 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3412 * @skb: skb to check
3414 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3415 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3416 * use this helper, to document places where we make this assertion.
3418 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
3421 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
3425 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
3427 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
3429 u32 skb_get_poff(const struct sk_buff *skb);
3430 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
3431 const struct flow_keys *keys, int hlen);
3434 * skb_head_is_locked - Determine if the skb->head is locked down
3435 * @skb: skb to check
3437 * The head on skbs build around a head frag can be removed if they are
3438 * not cloned. This function returns true if the skb head is locked down
3439 * due to either being allocated via kmalloc, or by being a clone with
3440 * multiple references to the head.
3442 static inline bool skb_head_is_locked(const struct sk_buff *skb)
3444 return !skb->head_frag || skb_cloned(skb);
3448 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3452 * skb_gso_network_seglen is used to determine the real size of the
3453 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3455 * The MAC/L2 header is not accounted for.
3457 static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
3459 unsigned int hdr_len = skb_transport_header(skb) -
3460 skb_network_header(skb);
3461 return hdr_len + skb_gso_transport_seglen(skb);
3463 #endif /* __KERNEL__ */
3464 #endif /* _LINUX_SKBUFF_H */