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>
24 #include <linux/atomic.h>
25 #include <asm/types.h>
26 #include <linux/spinlock.h>
27 #include <linux/net.h>
28 #include <linux/textsearch.h>
29 #include <net/checksum.h>
30 #include <linux/rcupdate.h>
31 #include <linux/hrtimer.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/netdev_features.h>
34 #include <linux/sched.h>
35 #include <net/flow_keys.h>
37 /* A. Checksumming of received packets by device.
41 * Device failed to checksum this packet e.g. due to lack of capabilities.
42 * The packet contains full (though not verified) checksum in packet but
43 * not in skb->csum. Thus, skb->csum is undefined in this case.
45 * CHECKSUM_UNNECESSARY:
47 * The hardware you're dealing with doesn't calculate the full checksum
48 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
49 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
50 * if their checksums are okay. skb->csum is still undefined in this case
51 * though. It is a bad option, but, unfortunately, nowadays most vendors do
52 * this. Apparently with the secret goal to sell you new devices, when you
53 * will add new protocol to your host, f.e. IPv6 8)
55 * CHECKSUM_UNNECESSARY is applicable to following protocols:
57 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
58 * zero UDP checksum for either IPv4 or IPv6, the networking stack
59 * may perform further validation in this case.
60 * GRE: only if the checksum is present in the header.
61 * SCTP: indicates the CRC in SCTP header has been validated.
63 * skb->csum_level indicates the number of consecutive checksums found in
64 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
65 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
66 * and a device is able to verify the checksums for UDP (possibly zero),
67 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
68 * two. If the device were only able to verify the UDP checksum and not
69 * GRE, either because it doesn't support GRE checksum of because GRE
70 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
71 * not considered in this case).
75 * This is the most generic way. The device supplied checksum of the _whole_
76 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
77 * hardware doesn't need to parse L3/L4 headers to implement this.
79 * Note: Even if device supports only some protocols, but is able to produce
80 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
84 * This is identical to the case for output below. This may occur on a packet
85 * received directly from another Linux OS, e.g., a virtualized Linux kernel
86 * on the same host. The packet can be treated in the same way as
87 * CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the
88 * checksum must be filled in by the OS or the hardware.
90 * B. Checksumming on output.
94 * The skb was already checksummed by the protocol, or a checksum is not
99 * The device is required to checksum the packet as seen by hard_start_xmit()
100 * from skb->csum_start up to the end, and to record/write the checksum at
101 * offset skb->csum_start + skb->csum_offset.
103 * The device must show its capabilities in dev->features, set up at device
104 * setup time, e.g. netdev_features.h:
106 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
107 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
108 * IPv4. Sigh. Vendors like this way for an unknown reason.
109 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
110 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
111 * NETIF_F_... - Well, you get the picture.
113 * CHECKSUM_UNNECESSARY:
115 * Normally, the device will do per protocol specific checksumming. Protocol
116 * implementations that do not want the NIC to perform the checksum
117 * calculation should use this flag in their outgoing skbs.
119 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
120 * offload. Correspondingly, the FCoE protocol driver
121 * stack should use CHECKSUM_UNNECESSARY.
123 * Any questions? No questions, good. --ANK
126 /* Don't change this without changing skb_csum_unnecessary! */
127 #define CHECKSUM_NONE 0
128 #define CHECKSUM_UNNECESSARY 1
129 #define CHECKSUM_COMPLETE 2
130 #define CHECKSUM_PARTIAL 3
132 /* Maximum value in skb->csum_level */
133 #define SKB_MAX_CSUM_LEVEL 3
135 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
136 #define SKB_WITH_OVERHEAD(X) \
137 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
138 #define SKB_MAX_ORDER(X, ORDER) \
139 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
140 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
141 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
143 /* return minimum truesize of one skb containing X bytes of data */
144 #define SKB_TRUESIZE(X) ((X) + \
145 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
146 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
150 struct pipe_inode_info;
152 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
153 struct nf_conntrack {
158 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
159 struct nf_bridge_info {
162 struct net_device *physindev;
163 struct net_device *physoutdev;
164 unsigned long data[32 / sizeof(unsigned long)];
168 struct sk_buff_head {
169 /* These two members must be first. */
170 struct sk_buff *next;
171 struct sk_buff *prev;
179 /* To allow 64K frame to be packed as single skb without frag_list we
180 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
181 * buffers which do not start on a page boundary.
183 * Since GRO uses frags we allocate at least 16 regardless of page
186 #if (65536/PAGE_SIZE + 1) < 16
187 #define MAX_SKB_FRAGS 16UL
189 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
191 extern int sysctl_max_skb_frags;
193 typedef struct skb_frag_struct skb_frag_t;
195 struct skb_frag_struct {
199 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
208 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
213 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
218 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
223 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
228 #define HAVE_HW_TIME_STAMP
231 * struct skb_shared_hwtstamps - hardware time stamps
232 * @hwtstamp: hardware time stamp transformed into duration
233 * since arbitrary point in time
235 * Software time stamps generated by ktime_get_real() are stored in
238 * hwtstamps can only be compared against other hwtstamps from
241 * This structure is attached to packets as part of the
242 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
244 struct skb_shared_hwtstamps {
248 /* Definitions for tx_flags in struct skb_shared_info */
250 /* generate hardware time stamp */
251 SKBTX_HW_TSTAMP = 1 << 0,
253 /* generate software time stamp when queueing packet to NIC */
254 SKBTX_SW_TSTAMP = 1 << 1,
256 /* device driver is going to provide hardware time stamp */
257 SKBTX_IN_PROGRESS = 1 << 2,
259 /* device driver supports TX zero-copy buffers */
260 SKBTX_DEV_ZEROCOPY = 1 << 3,
262 /* generate wifi status information (where possible) */
263 SKBTX_WIFI_STATUS = 1 << 4,
265 /* This indicates at least one fragment might be overwritten
266 * (as in vmsplice(), sendfile() ...)
267 * If we need to compute a TX checksum, we'll need to copy
268 * all frags to avoid possible bad checksum
270 SKBTX_SHARED_FRAG = 1 << 5,
272 /* generate software time stamp when entering packet scheduling */
273 SKBTX_SCHED_TSTAMP = 1 << 6,
275 /* generate software timestamp on peer data acknowledgment */
276 SKBTX_ACK_TSTAMP = 1 << 7,
279 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
280 SKBTX_SCHED_TSTAMP | \
282 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
285 * The callback notifies userspace to release buffers when skb DMA is done in
286 * lower device, the skb last reference should be 0 when calling this.
287 * The zerocopy_success argument is true if zero copy transmit occurred,
288 * false on data copy or out of memory error caused by data copy attempt.
289 * The ctx field is used to track device context.
290 * The desc field is used to track userspace buffer index.
293 void (*callback)(struct ubuf_info *, bool zerocopy_success);
298 /* This data is invariant across clones and lives at
299 * the end of the header data, ie. at skb->end.
301 struct skb_shared_info {
302 unsigned char nr_frags;
304 unsigned short gso_size;
305 /* Warning: this field is not always filled in (UFO)! */
306 unsigned short gso_segs;
307 unsigned short gso_type;
308 struct sk_buff *frag_list;
309 struct skb_shared_hwtstamps hwtstamps;
314 * Warning : all fields before dataref are cleared in __alloc_skb()
318 /* Intermediate layers must ensure that destructor_arg
319 * remains valid until skb destructor */
320 void * destructor_arg;
322 /* must be last field, see pskb_expand_head() */
323 skb_frag_t frags[MAX_SKB_FRAGS];
326 /* We divide dataref into two halves. The higher 16 bits hold references
327 * to the payload part of skb->data. The lower 16 bits hold references to
328 * the entire skb->data. A clone of a headerless skb holds the length of
329 * the header in skb->hdr_len.
331 * All users must obey the rule that the skb->data reference count must be
332 * greater than or equal to the payload reference count.
334 * Holding a reference to the payload part means that the user does not
335 * care about modifications to the header part of skb->data.
337 #define SKB_DATAREF_SHIFT 16
338 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
342 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
343 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
344 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
345 SKB_FCLONE_FREE, /* this companion fclone skb is available */
349 SKB_GSO_TCPV4 = 1 << 0,
350 SKB_GSO_UDP = 1 << 1,
352 /* This indicates the skb is from an untrusted source. */
353 SKB_GSO_DODGY = 1 << 2,
355 /* This indicates the tcp segment has CWR set. */
356 SKB_GSO_TCP_ECN = 1 << 3,
358 SKB_GSO_TCPV6 = 1 << 4,
360 SKB_GSO_FCOE = 1 << 5,
362 SKB_GSO_GRE = 1 << 6,
364 SKB_GSO_GRE_CSUM = 1 << 7,
366 SKB_GSO_IPIP = 1 << 8,
368 SKB_GSO_SIT = 1 << 9,
370 SKB_GSO_UDP_TUNNEL = 1 << 10,
372 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
374 SKB_GSO_MPLS = 1 << 12,
378 #if BITS_PER_LONG > 32
379 #define NET_SKBUFF_DATA_USES_OFFSET 1
382 #ifdef NET_SKBUFF_DATA_USES_OFFSET
383 typedef unsigned int sk_buff_data_t;
385 typedef unsigned char *sk_buff_data_t;
389 * struct skb_mstamp - multi resolution time stamps
390 * @stamp_us: timestamp in us resolution
391 * @stamp_jiffies: timestamp in jiffies
404 * skb_mstamp_get - get current timestamp
405 * @cl: place to store timestamps
407 static inline void skb_mstamp_get(struct skb_mstamp *cl)
409 u64 val = local_clock();
411 do_div(val, NSEC_PER_USEC);
412 cl->stamp_us = (u32)val;
413 cl->stamp_jiffies = (u32)jiffies;
417 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
418 * @t1: pointer to newest sample
419 * @t0: pointer to oldest sample
421 static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1,
422 const struct skb_mstamp *t0)
424 s32 delta_us = t1->stamp_us - t0->stamp_us;
425 u32 delta_jiffies = t1->stamp_jiffies - t0->stamp_jiffies;
427 /* If delta_us is negative, this might be because interval is too big,
428 * or local_clock() drift is too big : fallback using jiffies.
431 delta_jiffies >= (INT_MAX / (USEC_PER_SEC / HZ)))
433 delta_us = jiffies_to_usecs(delta_jiffies);
440 * struct sk_buff - socket buffer
441 * @next: Next buffer in list
442 * @prev: Previous buffer in list
443 * @tstamp: Time we arrived/left
444 * @sk: Socket we are owned by
445 * @dev: Device we arrived on/are leaving by
446 * @cb: Control buffer. Free for use by every layer. Put private vars here
447 * @_skb_refdst: destination entry (with norefcount bit)
448 * @sp: the security path, used for xfrm
449 * @len: Length of actual data
450 * @data_len: Data length
451 * @mac_len: Length of link layer header
452 * @hdr_len: writable header length of cloned skb
453 * @csum: Checksum (must include start/offset pair)
454 * @csum_start: Offset from skb->head where checksumming should start
455 * @csum_offset: Offset from csum_start where checksum should be stored
456 * @priority: Packet queueing priority
457 * @ignore_df: allow local fragmentation
458 * @cloned: Head may be cloned (check refcnt to be sure)
459 * @ip_summed: Driver fed us an IP checksum
460 * @nohdr: Payload reference only, must not modify header
461 * @nfctinfo: Relationship of this skb to the connection
462 * @pkt_type: Packet class
463 * @fclone: skbuff clone status
464 * @ipvs_property: skbuff is owned by ipvs
465 * @peeked: this packet has been seen already, so stats have been
466 * done for it, don't do them again
467 * @nf_trace: netfilter packet trace flag
468 * @protocol: Packet protocol from driver
469 * @destructor: Destruct function
470 * @nfct: Associated connection, if any
471 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
472 * @skb_iif: ifindex of device we arrived on
473 * @tc_index: Traffic control index
474 * @tc_verd: traffic control verdict
475 * @hash: the packet hash
476 * @queue_mapping: Queue mapping for multiqueue devices
477 * @xmit_more: More SKBs are pending for this queue
478 * @ndisc_nodetype: router type (from link layer)
479 * @ooo_okay: allow the mapping of a socket to a queue to be changed
480 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
482 * @sw_hash: indicates hash was computed in software stack
483 * @wifi_acked_valid: wifi_acked was set
484 * @wifi_acked: whether frame was acked on wifi or not
485 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
486 * @napi_id: id of the NAPI struct this skb came from
487 * @secmark: security marking
488 * @mark: Generic packet mark
489 * @dropcount: total number of sk_receive_queue overflows
490 * @vlan_proto: vlan encapsulation protocol
491 * @vlan_tci: vlan tag control information
492 * @inner_protocol: Protocol (encapsulation)
493 * @inner_transport_header: Inner transport layer header (encapsulation)
494 * @inner_network_header: Network layer header (encapsulation)
495 * @inner_mac_header: Link layer header (encapsulation)
496 * @transport_header: Transport layer header
497 * @network_header: Network layer header
498 * @mac_header: Link layer header
499 * @tail: Tail pointer
501 * @head: Head of buffer
502 * @data: Data head pointer
503 * @truesize: Buffer size
504 * @users: User count - see {datagram,tcp}.c
508 /* These two members must be first. */
509 struct sk_buff *next;
510 struct sk_buff *prev;
514 struct skb_mstamp skb_mstamp;
518 struct net_device *dev;
521 * This is the control buffer. It is free to use for every
522 * layer. Please put your private variables there. If you
523 * want to keep them across layers you have to do a skb_clone()
524 * first. This is owned by whoever has the skb queued ATM.
526 char cb[48] __aligned(8);
528 unsigned long _skb_refdst;
529 void (*destructor)(struct sk_buff *skb);
533 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
534 struct nf_conntrack *nfct;
536 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
537 struct nf_bridge_info *nf_bridge;
544 /* Following fields are _not_ copied in __copy_skb_header()
545 * Note that queue_mapping is here mostly to fill a hole.
547 kmemcheck_bitfield_begin(flags1);
556 kmemcheck_bitfield_end(flags1);
558 /* fields enclosed in headers_start/headers_end are copied
559 * using a single memcpy() in __copy_skb_header()
562 __u32 headers_start[0];
565 /* if you move pkt_type around you also must adapt those constants */
566 #ifdef __BIG_ENDIAN_BITFIELD
567 #define PKT_TYPE_MAX (7 << 5)
569 #define PKT_TYPE_MAX 7
571 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
573 __u8 __pkt_type_offset[0];
584 __u8 wifi_acked_valid:1;
588 /* Indicates the inner headers are valid in the skbuff. */
589 __u8 encapsulation:1;
590 __u8 encap_hdr_csum:1;
592 __u8 csum_complete_sw:1;
596 #ifdef CONFIG_IPV6_NDISC_NODETYPE
597 __u8 ndisc_nodetype:2;
599 __u8 ipvs_property:1;
600 __u8 inner_protocol_type:1;
601 /* 4 or 6 bit hole */
603 #ifdef CONFIG_NET_SCHED
604 __u16 tc_index; /* traffic control index */
605 #ifdef CONFIG_NET_CLS_ACT
606 __u16 tc_verd; /* traffic control verdict */
622 #ifdef CONFIG_NET_RX_BUSY_POLL
623 unsigned int napi_id;
625 #ifdef CONFIG_NETWORK_SECMARK
631 __u32 reserved_tailroom;
635 __be16 inner_protocol;
639 __u16 inner_transport_header;
640 __u16 inner_network_header;
641 __u16 inner_mac_header;
644 __u16 transport_header;
645 __u16 network_header;
649 __u32 headers_end[0];
652 /* These elements must be at the end, see alloc_skb() for details. */
657 unsigned int truesize;
663 * Handling routines are only of interest to the kernel
665 #include <linux/slab.h>
668 #define SKB_ALLOC_FCLONE 0x01
669 #define SKB_ALLOC_RX 0x02
671 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
672 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
674 return unlikely(skb->pfmemalloc);
678 * skb might have a dst pointer attached, refcounted or not.
679 * _skb_refdst low order bit is set if refcount was _not_ taken
681 #define SKB_DST_NOREF 1UL
682 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
685 * skb_dst - returns skb dst_entry
688 * Returns skb dst_entry, regardless of reference taken or not.
690 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
692 /* If refdst was not refcounted, check we still are in a
693 * rcu_read_lock section
695 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
696 !rcu_read_lock_held() &&
697 !rcu_read_lock_bh_held());
698 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
702 * skb_dst_set - sets skb dst
706 * Sets skb dst, assuming a reference was taken on dst and should
707 * be released by skb_dst_drop()
709 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
711 skb->_skb_refdst = (unsigned long)dst;
714 void __skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst,
718 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
722 * Sets skb dst, assuming a reference was not taken on dst.
723 * If dst entry is cached, we do not take reference and dst_release
724 * will be avoided by refdst_drop. If dst entry is not cached, we take
725 * reference, so that last dst_release can destroy the dst immediately.
727 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
729 __skb_dst_set_noref(skb, dst, false);
733 * skb_dst_set_noref_force - sets skb dst, without taking reference
737 * Sets skb dst, assuming a reference was not taken on dst.
738 * No reference is taken and no dst_release will be called. While for
739 * cached dsts deferred reclaim is a basic feature, for entries that are
740 * not cached it is caller's job to guarantee that last dst_release for
741 * provided dst happens when nobody uses it, eg. after a RCU grace period.
743 static inline void skb_dst_set_noref_force(struct sk_buff *skb,
744 struct dst_entry *dst)
746 __skb_dst_set_noref(skb, dst, true);
750 * skb_dst_is_noref - Test if skb dst isn't refcounted
753 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
755 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
758 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
760 return (struct rtable *)skb_dst(skb);
763 void kfree_skb(struct sk_buff *skb);
764 void kfree_skb_list(struct sk_buff *segs);
765 void skb_tx_error(struct sk_buff *skb);
766 void consume_skb(struct sk_buff *skb);
767 void __kfree_skb(struct sk_buff *skb);
768 extern struct kmem_cache *skbuff_head_cache;
770 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
771 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
772 bool *fragstolen, int *delta_truesize);
774 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
776 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
777 struct sk_buff *build_skb(void *data, unsigned int frag_size);
778 static inline struct sk_buff *alloc_skb(unsigned int size,
781 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
784 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
785 unsigned long data_len,
790 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
791 struct sk_buff_fclones {
800 * skb_fclone_busy - check if fclone is busy
803 * Returns true is skb is a fast clone, and its clone is not freed.
804 * Some drivers call skb_orphan() in their ndo_start_xmit(),
805 * so we also check that this didnt happen.
807 static inline bool skb_fclone_busy(const struct sock *sk,
808 const struct sk_buff *skb)
810 const struct sk_buff_fclones *fclones;
812 fclones = container_of(skb, struct sk_buff_fclones, skb1);
814 return skb->fclone == SKB_FCLONE_ORIG &&
815 fclones->skb2.fclone == SKB_FCLONE_CLONE &&
816 fclones->skb2.sk == sk;
819 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
822 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
825 struct sk_buff *__alloc_skb_head(gfp_t priority, int node);
826 static inline struct sk_buff *alloc_skb_head(gfp_t priority)
828 return __alloc_skb_head(priority, -1);
831 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
832 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
833 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
834 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
835 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
836 gfp_t gfp_mask, bool fclone);
837 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
840 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
843 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
844 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
845 unsigned int headroom);
846 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
847 int newtailroom, gfp_t priority);
848 int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
849 int offset, int len);
850 int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
852 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
853 int skb_pad(struct sk_buff *skb, int pad);
854 #define dev_kfree_skb(a) consume_skb(a)
856 int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
857 int getfrag(void *from, char *to, int offset,
858 int len, int odd, struct sk_buff *skb),
859 void *from, int length);
861 struct skb_seq_state {
865 __u32 stepped_offset;
866 struct sk_buff *root_skb;
867 struct sk_buff *cur_skb;
871 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
872 unsigned int to, struct skb_seq_state *st);
873 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
874 struct skb_seq_state *st);
875 void skb_abort_seq_read(struct skb_seq_state *st);
877 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
878 unsigned int to, struct ts_config *config,
879 struct ts_state *state);
882 * Packet hash types specify the type of hash in skb_set_hash.
884 * Hash types refer to the protocol layer addresses which are used to
885 * construct a packet's hash. The hashes are used to differentiate or identify
886 * flows of the protocol layer for the hash type. Hash types are either
887 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
889 * Properties of hashes:
891 * 1) Two packets in different flows have different hash values
892 * 2) Two packets in the same flow should have the same hash value
894 * A hash at a higher layer is considered to be more specific. A driver should
895 * set the most specific hash possible.
897 * A driver cannot indicate a more specific hash than the layer at which a hash
898 * was computed. For instance an L3 hash cannot be set as an L4 hash.
900 * A driver may indicate a hash level which is less specific than the
901 * actual layer the hash was computed on. For instance, a hash computed
902 * at L4 may be considered an L3 hash. This should only be done if the
903 * driver can't unambiguously determine that the HW computed the hash at
904 * the higher layer. Note that the "should" in the second property above
907 enum pkt_hash_types {
908 PKT_HASH_TYPE_NONE, /* Undefined type */
909 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
910 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
911 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
915 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
917 skb->l4_hash = (type == PKT_HASH_TYPE_L4);
922 void __skb_get_hash(struct sk_buff *skb);
923 static inline __u32 skb_get_hash(struct sk_buff *skb)
925 if (!skb->l4_hash && !skb->sw_hash)
931 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
936 static inline void skb_clear_hash(struct sk_buff *skb)
943 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
949 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
951 to->hash = from->hash;
952 to->sw_hash = from->sw_hash;
953 to->l4_hash = from->l4_hash;
956 #ifdef NET_SKBUFF_DATA_USES_OFFSET
957 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
959 return skb->head + skb->end;
962 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
967 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
972 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
974 return skb->end - skb->head;
979 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
981 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
983 return &skb_shinfo(skb)->hwtstamps;
987 * skb_queue_empty - check if a queue is empty
990 * Returns true if the queue is empty, false otherwise.
992 static inline int skb_queue_empty(const struct sk_buff_head *list)
994 return list->next == (const struct sk_buff *) list;
998 * skb_queue_is_last - check if skb is the last entry in the queue
1002 * Returns true if @skb is the last buffer on the list.
1004 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1005 const struct sk_buff *skb)
1007 return skb->next == (const struct sk_buff *) list;
1011 * skb_queue_is_first - check if skb is the first entry in the queue
1015 * Returns true if @skb is the first buffer on the list.
1017 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1018 const struct sk_buff *skb)
1020 return skb->prev == (const struct sk_buff *) list;
1024 * skb_queue_next - return the next packet in the queue
1026 * @skb: current buffer
1028 * Return the next packet in @list after @skb. It is only valid to
1029 * call this if skb_queue_is_last() evaluates to false.
1031 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1032 const struct sk_buff *skb)
1034 /* This BUG_ON may seem severe, but if we just return then we
1035 * are going to dereference garbage.
1037 BUG_ON(skb_queue_is_last(list, skb));
1042 * skb_queue_prev - return the prev packet in the queue
1044 * @skb: current buffer
1046 * Return the prev packet in @list before @skb. It is only valid to
1047 * call this if skb_queue_is_first() evaluates to false.
1049 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1050 const struct sk_buff *skb)
1052 /* This BUG_ON may seem severe, but if we just return then we
1053 * are going to dereference garbage.
1055 BUG_ON(skb_queue_is_first(list, skb));
1060 * skb_get - reference buffer
1061 * @skb: buffer to reference
1063 * Makes another reference to a socket buffer and returns a pointer
1066 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1068 atomic_inc(&skb->users);
1073 * If users == 1, we are the only owner and are can avoid redundant
1078 * skb_cloned - is the buffer a clone
1079 * @skb: buffer to check
1081 * Returns true if the buffer was generated with skb_clone() and is
1082 * one of multiple shared copies of the buffer. Cloned buffers are
1083 * shared data so must not be written to under normal circumstances.
1085 static inline int skb_cloned(const struct sk_buff *skb)
1087 return skb->cloned &&
1088 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1091 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1093 might_sleep_if(pri & __GFP_WAIT);
1095 if (skb_cloned(skb))
1096 return pskb_expand_head(skb, 0, 0, pri);
1102 * skb_header_cloned - is the header a clone
1103 * @skb: buffer to check
1105 * Returns true if modifying the header part of the buffer requires
1106 * the data to be copied.
1108 static inline int skb_header_cloned(const struct sk_buff *skb)
1115 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1116 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1117 return dataref != 1;
1121 * skb_header_release - release reference to header
1122 * @skb: buffer to operate on
1124 * Drop a reference to the header part of the buffer. This is done
1125 * by acquiring a payload reference. You must not read from the header
1126 * part of skb->data after this.
1127 * Note : Check if you can use __skb_header_release() instead.
1129 static inline void skb_header_release(struct sk_buff *skb)
1133 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
1137 * __skb_header_release - release reference to header
1138 * @skb: buffer to operate on
1140 * Variant of skb_header_release() assuming skb is private to caller.
1141 * We can avoid one atomic operation.
1143 static inline void __skb_header_release(struct sk_buff *skb)
1146 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1151 * skb_shared - is the buffer shared
1152 * @skb: buffer to check
1154 * Returns true if more than one person has a reference to this
1157 static inline int skb_shared(const struct sk_buff *skb)
1159 return atomic_read(&skb->users) != 1;
1163 * skb_share_check - check if buffer is shared and if so clone it
1164 * @skb: buffer to check
1165 * @pri: priority for memory allocation
1167 * If the buffer is shared the buffer is cloned and the old copy
1168 * drops a reference. A new clone with a single reference is returned.
1169 * If the buffer is not shared the original buffer is returned. When
1170 * being called from interrupt status or with spinlocks held pri must
1173 * NULL is returned on a memory allocation failure.
1175 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1177 might_sleep_if(pri & __GFP_WAIT);
1178 if (skb_shared(skb)) {
1179 struct sk_buff *nskb = skb_clone(skb, pri);
1191 * Copy shared buffers into a new sk_buff. We effectively do COW on
1192 * packets to handle cases where we have a local reader and forward
1193 * and a couple of other messy ones. The normal one is tcpdumping
1194 * a packet thats being forwarded.
1198 * skb_unshare - make a copy of a shared buffer
1199 * @skb: buffer to check
1200 * @pri: priority for memory allocation
1202 * If the socket buffer is a clone then this function creates a new
1203 * copy of the data, drops a reference count on the old copy and returns
1204 * the new copy with the reference count at 1. If the buffer is not a clone
1205 * the original buffer is returned. When called with a spinlock held or
1206 * from interrupt state @pri must be %GFP_ATOMIC
1208 * %NULL is returned on a memory allocation failure.
1210 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1213 might_sleep_if(pri & __GFP_WAIT);
1214 if (skb_cloned(skb)) {
1215 struct sk_buff *nskb = skb_copy(skb, pri);
1217 /* Free our shared copy */
1228 * skb_peek - peek at the head of an &sk_buff_head
1229 * @list_: list to peek at
1231 * Peek an &sk_buff. Unlike most other operations you _MUST_
1232 * be careful with this one. A peek leaves the buffer on the
1233 * list and someone else may run off with it. You must hold
1234 * the appropriate locks or have a private queue to do this.
1236 * Returns %NULL for an empty list or a pointer to the head element.
1237 * The reference count is not incremented and the reference is therefore
1238 * volatile. Use with caution.
1240 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1242 struct sk_buff *skb = list_->next;
1244 if (skb == (struct sk_buff *)list_)
1250 * skb_peek_next - peek skb following the given one from a queue
1251 * @skb: skb to start from
1252 * @list_: list to peek at
1254 * Returns %NULL when the end of the list is met or a pointer to the
1255 * next element. The reference count is not incremented and the
1256 * reference is therefore volatile. Use with caution.
1258 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1259 const struct sk_buff_head *list_)
1261 struct sk_buff *next = skb->next;
1263 if (next == (struct sk_buff *)list_)
1269 * skb_peek_tail - peek at the tail of an &sk_buff_head
1270 * @list_: list to peek at
1272 * Peek an &sk_buff. Unlike most other operations you _MUST_
1273 * be careful with this one. A peek leaves the buffer on the
1274 * list and someone else may run off with it. You must hold
1275 * the appropriate locks or have a private queue to do this.
1277 * Returns %NULL for an empty list or a pointer to the tail element.
1278 * The reference count is not incremented and the reference is therefore
1279 * volatile. Use with caution.
1281 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1283 struct sk_buff *skb = list_->prev;
1285 if (skb == (struct sk_buff *)list_)
1292 * skb_queue_len - get queue length
1293 * @list_: list to measure
1295 * Return the length of an &sk_buff queue.
1297 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1303 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1304 * @list: queue to initialize
1306 * This initializes only the list and queue length aspects of
1307 * an sk_buff_head object. This allows to initialize the list
1308 * aspects of an sk_buff_head without reinitializing things like
1309 * the spinlock. It can also be used for on-stack sk_buff_head
1310 * objects where the spinlock is known to not be used.
1312 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1314 list->prev = list->next = (struct sk_buff *)list;
1319 * This function creates a split out lock class for each invocation;
1320 * this is needed for now since a whole lot of users of the skb-queue
1321 * infrastructure in drivers have different locking usage (in hardirq)
1322 * than the networking core (in softirq only). In the long run either the
1323 * network layer or drivers should need annotation to consolidate the
1324 * main types of usage into 3 classes.
1326 static inline void skb_queue_head_init(struct sk_buff_head *list)
1328 spin_lock_init(&list->lock);
1329 __skb_queue_head_init(list);
1332 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1333 struct lock_class_key *class)
1335 skb_queue_head_init(list);
1336 lockdep_set_class(&list->lock, class);
1340 * Insert an sk_buff on a list.
1342 * The "__skb_xxxx()" functions are the non-atomic ones that
1343 * can only be called with interrupts disabled.
1345 void skb_insert(struct sk_buff *old, struct sk_buff *newsk,
1346 struct sk_buff_head *list);
1347 static inline void __skb_insert(struct sk_buff *newsk,
1348 struct sk_buff *prev, struct sk_buff *next,
1349 struct sk_buff_head *list)
1353 next->prev = prev->next = newsk;
1357 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1358 struct sk_buff *prev,
1359 struct sk_buff *next)
1361 struct sk_buff *first = list->next;
1362 struct sk_buff *last = list->prev;
1372 * skb_queue_splice - join two skb lists, this is designed for stacks
1373 * @list: the new list to add
1374 * @head: the place to add it in the first list
1376 static inline void skb_queue_splice(const struct sk_buff_head *list,
1377 struct sk_buff_head *head)
1379 if (!skb_queue_empty(list)) {
1380 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1381 head->qlen += list->qlen;
1386 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1387 * @list: the new list to add
1388 * @head: the place to add it in the first list
1390 * The list at @list is reinitialised
1392 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1393 struct sk_buff_head *head)
1395 if (!skb_queue_empty(list)) {
1396 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1397 head->qlen += list->qlen;
1398 __skb_queue_head_init(list);
1403 * skb_queue_splice_tail - join two skb lists, each list being a queue
1404 * @list: the new list to add
1405 * @head: the place to add it in the first list
1407 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1408 struct sk_buff_head *head)
1410 if (!skb_queue_empty(list)) {
1411 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1412 head->qlen += list->qlen;
1417 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1418 * @list: the new list to add
1419 * @head: the place to add it in the first list
1421 * Each of the lists is a queue.
1422 * The list at @list is reinitialised
1424 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1425 struct sk_buff_head *head)
1427 if (!skb_queue_empty(list)) {
1428 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1429 head->qlen += list->qlen;
1430 __skb_queue_head_init(list);
1435 * __skb_queue_after - queue a buffer at the list head
1436 * @list: list to use
1437 * @prev: place after this buffer
1438 * @newsk: buffer to queue
1440 * Queue a buffer int the middle of a list. This function takes no locks
1441 * and you must therefore hold required locks before calling it.
1443 * A buffer cannot be placed on two lists at the same time.
1445 static inline void __skb_queue_after(struct sk_buff_head *list,
1446 struct sk_buff *prev,
1447 struct sk_buff *newsk)
1449 __skb_insert(newsk, prev, prev->next, list);
1452 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1453 struct sk_buff_head *list);
1455 static inline void __skb_queue_before(struct sk_buff_head *list,
1456 struct sk_buff *next,
1457 struct sk_buff *newsk)
1459 __skb_insert(newsk, next->prev, next, list);
1463 * __skb_queue_head - queue a buffer at the list head
1464 * @list: list to use
1465 * @newsk: buffer to queue
1467 * Queue a buffer at the start of a list. This function takes no locks
1468 * and you must therefore hold required locks before calling it.
1470 * A buffer cannot be placed on two lists at the same time.
1472 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1473 static inline void __skb_queue_head(struct sk_buff_head *list,
1474 struct sk_buff *newsk)
1476 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1480 * __skb_queue_tail - queue a buffer at the list tail
1481 * @list: list to use
1482 * @newsk: buffer to queue
1484 * Queue a buffer at the end of a list. This function takes no locks
1485 * and you must therefore hold required locks before calling it.
1487 * A buffer cannot be placed on two lists at the same time.
1489 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1490 static inline void __skb_queue_tail(struct sk_buff_head *list,
1491 struct sk_buff *newsk)
1493 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1497 * remove sk_buff from list. _Must_ be called atomically, and with
1500 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1501 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1503 struct sk_buff *next, *prev;
1508 skb->next = skb->prev = NULL;
1514 * __skb_dequeue - remove from the head of the queue
1515 * @list: list to dequeue from
1517 * Remove the head of the list. This function does not take any locks
1518 * so must be used with appropriate locks held only. The head item is
1519 * returned or %NULL if the list is empty.
1521 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1522 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1524 struct sk_buff *skb = skb_peek(list);
1526 __skb_unlink(skb, list);
1531 * __skb_dequeue_tail - remove from the tail of the queue
1532 * @list: list to dequeue from
1534 * Remove the tail of the list. This function does not take any locks
1535 * so must be used with appropriate locks held only. The tail item is
1536 * returned or %NULL if the list is empty.
1538 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1539 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1541 struct sk_buff *skb = skb_peek_tail(list);
1543 __skb_unlink(skb, list);
1548 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1550 return skb->data_len;
1553 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1555 return skb->len - skb->data_len;
1558 static inline int skb_pagelen(const struct sk_buff *skb)
1562 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1563 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1564 return len + skb_headlen(skb);
1568 * __skb_fill_page_desc - initialise a paged fragment in an skb
1569 * @skb: buffer containing fragment to be initialised
1570 * @i: paged fragment index to initialise
1571 * @page: the page to use for this fragment
1572 * @off: the offset to the data with @page
1573 * @size: the length of the data
1575 * Initialises the @i'th fragment of @skb to point to &size bytes at
1576 * offset @off within @page.
1578 * Does not take any additional reference on the fragment.
1580 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1581 struct page *page, int off, int size)
1583 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1586 * Propagate page->pfmemalloc to the skb if we can. The problem is
1587 * that not all callers have unique ownership of the page. If
1588 * pfmemalloc is set, we check the mapping as a mapping implies
1589 * page->index is set (index and pfmemalloc share space).
1590 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1591 * do not lose pfmemalloc information as the pages would not be
1592 * allocated using __GFP_MEMALLOC.
1594 frag->page.p = page;
1595 frag->page_offset = off;
1596 skb_frag_size_set(frag, size);
1598 page = compound_head(page);
1599 if (page->pfmemalloc && !page->mapping)
1600 skb->pfmemalloc = true;
1604 * skb_fill_page_desc - initialise a paged fragment in an skb
1605 * @skb: buffer containing fragment to be initialised
1606 * @i: paged fragment index to initialise
1607 * @page: the page to use for this fragment
1608 * @off: the offset to the data with @page
1609 * @size: the length of the data
1611 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1612 * @skb to point to @size bytes at offset @off within @page. In
1613 * addition updates @skb such that @i is the last fragment.
1615 * Does not take any additional reference on the fragment.
1617 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1618 struct page *page, int off, int size)
1620 __skb_fill_page_desc(skb, i, page, off, size);
1621 skb_shinfo(skb)->nr_frags = i + 1;
1624 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
1625 int size, unsigned int truesize);
1627 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
1628 unsigned int truesize);
1630 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1631 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1632 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1634 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1635 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1637 return skb->head + skb->tail;
1640 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1642 skb->tail = skb->data - skb->head;
1645 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1647 skb_reset_tail_pointer(skb);
1648 skb->tail += offset;
1651 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1652 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1657 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1659 skb->tail = skb->data;
1662 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1664 skb->tail = skb->data + offset;
1667 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1670 * Add data to an sk_buff
1672 unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
1673 unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1674 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1676 unsigned char *tmp = skb_tail_pointer(skb);
1677 SKB_LINEAR_ASSERT(skb);
1683 unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1684 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1691 unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1692 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1695 BUG_ON(skb->len < skb->data_len);
1696 return skb->data += len;
1699 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1701 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1704 unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1706 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1708 if (len > skb_headlen(skb) &&
1709 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1712 return skb->data += len;
1715 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1717 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1720 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1722 if (likely(len <= skb_headlen(skb)))
1724 if (unlikely(len > skb->len))
1726 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1730 * skb_headroom - bytes at buffer head
1731 * @skb: buffer to check
1733 * Return the number of bytes of free space at the head of an &sk_buff.
1735 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1737 return skb->data - skb->head;
1741 * skb_tailroom - bytes at buffer end
1742 * @skb: buffer to check
1744 * Return the number of bytes of free space at the tail of an sk_buff
1746 static inline int skb_tailroom(const struct sk_buff *skb)
1748 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1752 * skb_availroom - bytes at buffer end
1753 * @skb: buffer to check
1755 * Return the number of bytes of free space at the tail of an sk_buff
1756 * allocated by sk_stream_alloc()
1758 static inline int skb_availroom(const struct sk_buff *skb)
1760 if (skb_is_nonlinear(skb))
1763 return skb->end - skb->tail - skb->reserved_tailroom;
1767 * skb_reserve - adjust headroom
1768 * @skb: buffer to alter
1769 * @len: bytes to move
1771 * Increase the headroom of an empty &sk_buff by reducing the tail
1772 * room. This is only allowed for an empty buffer.
1774 static inline void skb_reserve(struct sk_buff *skb, int len)
1780 #define ENCAP_TYPE_ETHER 0
1781 #define ENCAP_TYPE_IPPROTO 1
1783 static inline void skb_set_inner_protocol(struct sk_buff *skb,
1786 skb->inner_protocol = protocol;
1787 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
1790 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
1793 skb->inner_ipproto = ipproto;
1794 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
1797 static inline void skb_reset_inner_headers(struct sk_buff *skb)
1799 skb->inner_mac_header = skb->mac_header;
1800 skb->inner_network_header = skb->network_header;
1801 skb->inner_transport_header = skb->transport_header;
1804 static inline void skb_reset_mac_len(struct sk_buff *skb)
1806 skb->mac_len = skb->network_header - skb->mac_header;
1809 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1812 return skb->head + skb->inner_transport_header;
1815 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1817 skb->inner_transport_header = skb->data - skb->head;
1820 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1823 skb_reset_inner_transport_header(skb);
1824 skb->inner_transport_header += offset;
1827 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1829 return skb->head + skb->inner_network_header;
1832 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1834 skb->inner_network_header = skb->data - skb->head;
1837 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1840 skb_reset_inner_network_header(skb);
1841 skb->inner_network_header += offset;
1844 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1846 return skb->head + skb->inner_mac_header;
1849 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1851 skb->inner_mac_header = skb->data - skb->head;
1854 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1857 skb_reset_inner_mac_header(skb);
1858 skb->inner_mac_header += offset;
1860 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1862 return skb->transport_header != (typeof(skb->transport_header))~0U;
1865 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1867 return skb->head + skb->transport_header;
1870 static inline void skb_reset_transport_header(struct sk_buff *skb)
1872 skb->transport_header = skb->data - skb->head;
1875 static inline void skb_set_transport_header(struct sk_buff *skb,
1878 skb_reset_transport_header(skb);
1879 skb->transport_header += offset;
1882 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1884 return skb->head + skb->network_header;
1887 static inline void skb_reset_network_header(struct sk_buff *skb)
1889 skb->network_header = skb->data - skb->head;
1892 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1894 skb_reset_network_header(skb);
1895 skb->network_header += offset;
1898 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1900 return skb->head + skb->mac_header;
1903 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1905 return skb->mac_header != (typeof(skb->mac_header))~0U;
1908 static inline void skb_reset_mac_header(struct sk_buff *skb)
1910 skb->mac_header = skb->data - skb->head;
1913 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1915 skb_reset_mac_header(skb);
1916 skb->mac_header += offset;
1919 static inline void skb_pop_mac_header(struct sk_buff *skb)
1921 skb->mac_header = skb->network_header;
1924 static inline void skb_probe_transport_header(struct sk_buff *skb,
1925 const int offset_hint)
1927 struct flow_keys keys;
1929 if (skb_transport_header_was_set(skb))
1931 else if (skb_flow_dissect(skb, &keys))
1932 skb_set_transport_header(skb, keys.thoff);
1934 skb_set_transport_header(skb, offset_hint);
1937 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1939 if (skb_mac_header_was_set(skb)) {
1940 const unsigned char *old_mac = skb_mac_header(skb);
1942 skb_set_mac_header(skb, -skb->mac_len);
1943 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1947 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1949 return skb->csum_start - skb_headroom(skb);
1952 static inline int skb_transport_offset(const struct sk_buff *skb)
1954 return skb_transport_header(skb) - skb->data;
1957 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1959 return skb->transport_header - skb->network_header;
1962 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
1964 return skb->inner_transport_header - skb->inner_network_header;
1967 static inline int skb_network_offset(const struct sk_buff *skb)
1969 return skb_network_header(skb) - skb->data;
1972 static inline int skb_inner_network_offset(const struct sk_buff *skb)
1974 return skb_inner_network_header(skb) - skb->data;
1977 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1979 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1983 * CPUs often take a performance hit when accessing unaligned memory
1984 * locations. The actual performance hit varies, it can be small if the
1985 * hardware handles it or large if we have to take an exception and fix it
1988 * Since an ethernet header is 14 bytes network drivers often end up with
1989 * the IP header at an unaligned offset. The IP header can be aligned by
1990 * shifting the start of the packet by 2 bytes. Drivers should do this
1993 * skb_reserve(skb, NET_IP_ALIGN);
1995 * The downside to this alignment of the IP header is that the DMA is now
1996 * unaligned. On some architectures the cost of an unaligned DMA is high
1997 * and this cost outweighs the gains made by aligning the IP header.
1999 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2002 #ifndef NET_IP_ALIGN
2003 #define NET_IP_ALIGN 2
2007 * The networking layer reserves some headroom in skb data (via
2008 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2009 * the header has to grow. In the default case, if the header has to grow
2010 * 32 bytes or less we avoid the reallocation.
2012 * Unfortunately this headroom changes the DMA alignment of the resulting
2013 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2014 * on some architectures. An architecture can override this value,
2015 * perhaps setting it to a cacheline in size (since that will maintain
2016 * cacheline alignment of the DMA). It must be a power of 2.
2018 * Various parts of the networking layer expect at least 32 bytes of
2019 * headroom, you should not reduce this.
2021 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2022 * to reduce average number of cache lines per packet.
2023 * get_rps_cpus() for example only access one 64 bytes aligned block :
2024 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2027 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2030 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
2032 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
2034 if (unlikely(skb_is_nonlinear(skb))) {
2039 skb_set_tail_pointer(skb, len);
2042 void skb_trim(struct sk_buff *skb, unsigned int len);
2044 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
2047 return ___pskb_trim(skb, len);
2048 __skb_trim(skb, len);
2052 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
2054 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
2058 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2059 * @skb: buffer to alter
2062 * This is identical to pskb_trim except that the caller knows that
2063 * the skb is not cloned so we should never get an error due to out-
2066 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
2068 int err = pskb_trim(skb, len);
2073 * skb_orphan - orphan a buffer
2074 * @skb: buffer to orphan
2076 * If a buffer currently has an owner then we call the owner's
2077 * destructor function and make the @skb unowned. The buffer continues
2078 * to exist but is no longer charged to its former owner.
2080 static inline void skb_orphan(struct sk_buff *skb)
2082 if (skb->destructor) {
2083 skb->destructor(skb);
2084 skb->destructor = NULL;
2092 * skb_orphan_frags - orphan the frags contained in a buffer
2093 * @skb: buffer to orphan frags from
2094 * @gfp_mask: allocation mask for replacement pages
2096 * For each frag in the SKB which needs a destructor (i.e. has an
2097 * owner) create a copy of that frag and release the original
2098 * page by calling the destructor.
2100 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2102 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
2104 return skb_copy_ubufs(skb, gfp_mask);
2108 * __skb_queue_purge - empty a list
2109 * @list: list to empty
2111 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2112 * the list and one reference dropped. This function does not take the
2113 * list lock and the caller must hold the relevant locks to use it.
2115 void skb_queue_purge(struct sk_buff_head *list);
2116 static inline void __skb_queue_purge(struct sk_buff_head *list)
2118 struct sk_buff *skb;
2119 while ((skb = __skb_dequeue(list)) != NULL)
2123 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2124 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2125 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2127 void *netdev_alloc_frag(unsigned int fragsz);
2129 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2133 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2134 * @dev: network device to receive on
2135 * @length: length to allocate
2137 * Allocate a new &sk_buff and assign it a usage count of one. The
2138 * buffer has unspecified headroom built in. Users should allocate
2139 * the headroom they think they need without accounting for the
2140 * built in space. The built in space is used for optimisations.
2142 * %NULL is returned if there is no free memory. Although this function
2143 * allocates memory it can be called from an interrupt.
2145 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2146 unsigned int length)
2148 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2151 /* legacy helper around __netdev_alloc_skb() */
2152 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2155 return __netdev_alloc_skb(NULL, length, gfp_mask);
2158 /* legacy helper around netdev_alloc_skb() */
2159 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2161 return netdev_alloc_skb(NULL, length);
2165 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2166 unsigned int length, gfp_t gfp)
2168 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2170 if (NET_IP_ALIGN && skb)
2171 skb_reserve(skb, NET_IP_ALIGN);
2175 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2176 unsigned int length)
2178 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2182 * __skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data
2183 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2184 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2185 * @order: size of the allocation
2187 * Allocate a new page.
2189 * %NULL is returned if there is no free memory.
2191 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
2192 struct sk_buff *skb,
2197 gfp_mask |= __GFP_COLD;
2199 if (!(gfp_mask & __GFP_NOMEMALLOC))
2200 gfp_mask |= __GFP_MEMALLOC;
2202 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2203 if (skb && page && page->pfmemalloc)
2204 skb->pfmemalloc = true;
2210 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
2211 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2212 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2214 * Allocate a new page.
2216 * %NULL is returned if there is no free memory.
2218 static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
2219 struct sk_buff *skb)
2221 return __skb_alloc_pages(gfp_mask, skb, 0);
2225 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2226 * @page: The page that was allocated from skb_alloc_page
2227 * @skb: The skb that may need pfmemalloc set
2229 static inline void skb_propagate_pfmemalloc(struct page *page,
2230 struct sk_buff *skb)
2232 if (page && page->pfmemalloc)
2233 skb->pfmemalloc = true;
2237 * skb_frag_page - retrieve the page referred to by a paged fragment
2238 * @frag: the paged fragment
2240 * Returns the &struct page associated with @frag.
2242 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2244 return frag->page.p;
2248 * __skb_frag_ref - take an addition reference on a paged fragment.
2249 * @frag: the paged fragment
2251 * Takes an additional reference on the paged fragment @frag.
2253 static inline void __skb_frag_ref(skb_frag_t *frag)
2255 get_page(skb_frag_page(frag));
2259 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2261 * @f: the fragment offset.
2263 * Takes an additional reference on the @f'th paged fragment of @skb.
2265 static inline void skb_frag_ref(struct sk_buff *skb, int f)
2267 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
2271 * __skb_frag_unref - release a reference on a paged fragment.
2272 * @frag: the paged fragment
2274 * Releases a reference on the paged fragment @frag.
2276 static inline void __skb_frag_unref(skb_frag_t *frag)
2278 put_page(skb_frag_page(frag));
2282 * skb_frag_unref - release a reference on a paged fragment of an skb.
2284 * @f: the fragment offset
2286 * Releases a reference on the @f'th paged fragment of @skb.
2288 static inline void skb_frag_unref(struct sk_buff *skb, int f)
2290 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
2294 * skb_frag_address - gets the address of the data contained in a paged fragment
2295 * @frag: the paged fragment buffer
2297 * Returns the address of the data within @frag. The page must already
2300 static inline void *skb_frag_address(const skb_frag_t *frag)
2302 return page_address(skb_frag_page(frag)) + frag->page_offset;
2306 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2307 * @frag: the paged fragment buffer
2309 * Returns the address of the data within @frag. Checks that the page
2310 * is mapped and returns %NULL otherwise.
2312 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
2314 void *ptr = page_address(skb_frag_page(frag));
2318 return ptr + frag->page_offset;
2322 * __skb_frag_set_page - sets the page contained in a paged fragment
2323 * @frag: the paged fragment
2324 * @page: the page to set
2326 * Sets the fragment @frag to contain @page.
2328 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
2330 frag->page.p = page;
2334 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2336 * @f: the fragment offset
2337 * @page: the page to set
2339 * Sets the @f'th fragment of @skb to contain @page.
2341 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
2344 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
2347 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
2350 * skb_frag_dma_map - maps a paged fragment via the DMA API
2351 * @dev: the device to map the fragment to
2352 * @frag: the paged fragment to map
2353 * @offset: the offset within the fragment (starting at the
2354 * fragment's own offset)
2355 * @size: the number of bytes to map
2356 * @dir: the direction of the mapping (%PCI_DMA_*)
2358 * Maps the page associated with @frag to @device.
2360 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
2361 const skb_frag_t *frag,
2362 size_t offset, size_t size,
2363 enum dma_data_direction dir)
2365 return dma_map_page(dev, skb_frag_page(frag),
2366 frag->page_offset + offset, size, dir);
2369 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
2372 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
2376 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
2379 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
2384 * skb_clone_writable - is the header of a clone writable
2385 * @skb: buffer to check
2386 * @len: length up to which to write
2388 * Returns true if modifying the header part of the cloned buffer
2389 * does not requires the data to be copied.
2391 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
2393 return !skb_header_cloned(skb) &&
2394 skb_headroom(skb) + len <= skb->hdr_len;
2397 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
2402 if (headroom > skb_headroom(skb))
2403 delta = headroom - skb_headroom(skb);
2405 if (delta || cloned)
2406 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2412 * skb_cow - copy header of skb when it is required
2413 * @skb: buffer to cow
2414 * @headroom: needed headroom
2416 * If the skb passed lacks sufficient headroom or its data part
2417 * is shared, data is reallocated. If reallocation fails, an error
2418 * is returned and original skb is not changed.
2420 * The result is skb with writable area skb->head...skb->tail
2421 * and at least @headroom of space at head.
2423 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2425 return __skb_cow(skb, headroom, skb_cloned(skb));
2429 * skb_cow_head - skb_cow but only making the head writable
2430 * @skb: buffer to cow
2431 * @headroom: needed headroom
2433 * This function is identical to skb_cow except that we replace the
2434 * skb_cloned check by skb_header_cloned. It should be used when
2435 * you only need to push on some header and do not need to modify
2438 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2440 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2444 * skb_padto - pad an skbuff up to a minimal size
2445 * @skb: buffer to pad
2446 * @len: minimal length
2448 * Pads up a buffer to ensure the trailing bytes exist and are
2449 * blanked. If the buffer already contains sufficient data it
2450 * is untouched. Otherwise it is extended. Returns zero on
2451 * success. The skb is freed on error.
2454 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2456 unsigned int size = skb->len;
2457 if (likely(size >= len))
2459 return skb_pad(skb, len - size);
2462 static inline int skb_add_data(struct sk_buff *skb,
2463 char __user *from, int copy)
2465 const int off = skb->len;
2467 if (skb->ip_summed == CHECKSUM_NONE) {
2469 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2472 skb->csum = csum_block_add(skb->csum, csum, off);
2475 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2478 __skb_trim(skb, off);
2482 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2483 const struct page *page, int off)
2486 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2488 return page == skb_frag_page(frag) &&
2489 off == frag->page_offset + skb_frag_size(frag);
2494 static inline int __skb_linearize(struct sk_buff *skb)
2496 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2500 * skb_linearize - convert paged skb to linear one
2501 * @skb: buffer to linarize
2503 * If there is no free memory -ENOMEM is returned, otherwise zero
2504 * is returned and the old skb data released.
2506 static inline int skb_linearize(struct sk_buff *skb)
2508 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2512 * skb_has_shared_frag - can any frag be overwritten
2513 * @skb: buffer to test
2515 * Return true if the skb has at least one frag that might be modified
2516 * by an external entity (as in vmsplice()/sendfile())
2518 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
2520 return skb_is_nonlinear(skb) &&
2521 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
2525 * skb_linearize_cow - make sure skb is linear and writable
2526 * @skb: buffer to process
2528 * If there is no free memory -ENOMEM is returned, otherwise zero
2529 * is returned and the old skb data released.
2531 static inline int skb_linearize_cow(struct sk_buff *skb)
2533 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2534 __skb_linearize(skb) : 0;
2538 * skb_postpull_rcsum - update checksum for received skb after pull
2539 * @skb: buffer to update
2540 * @start: start of data before pull
2541 * @len: length of data pulled
2543 * After doing a pull on a received packet, you need to call this to
2544 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2545 * CHECKSUM_NONE so that it can be recomputed from scratch.
2548 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2549 const void *start, unsigned int len)
2551 if (skb->ip_summed == CHECKSUM_COMPLETE)
2552 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2553 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
2554 skb_checksum_start_offset(skb) < 0)
2555 skb->ip_summed = CHECKSUM_NONE;
2558 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2561 * pskb_trim_rcsum - trim received skb and update checksum
2562 * @skb: buffer to trim
2565 * This is exactly the same as pskb_trim except that it ensures the
2566 * checksum of received packets are still valid after the operation.
2569 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2571 if (likely(len >= skb->len))
2573 if (skb->ip_summed == CHECKSUM_COMPLETE)
2574 skb->ip_summed = CHECKSUM_NONE;
2575 return __pskb_trim(skb, len);
2578 #define skb_queue_walk(queue, skb) \
2579 for (skb = (queue)->next; \
2580 skb != (struct sk_buff *)(queue); \
2583 #define skb_queue_walk_safe(queue, skb, tmp) \
2584 for (skb = (queue)->next, tmp = skb->next; \
2585 skb != (struct sk_buff *)(queue); \
2586 skb = tmp, tmp = skb->next)
2588 #define skb_queue_walk_from(queue, skb) \
2589 for (; skb != (struct sk_buff *)(queue); \
2592 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2593 for (tmp = skb->next; \
2594 skb != (struct sk_buff *)(queue); \
2595 skb = tmp, tmp = skb->next)
2597 #define skb_queue_reverse_walk(queue, skb) \
2598 for (skb = (queue)->prev; \
2599 skb != (struct sk_buff *)(queue); \
2602 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2603 for (skb = (queue)->prev, tmp = skb->prev; \
2604 skb != (struct sk_buff *)(queue); \
2605 skb = tmp, tmp = skb->prev)
2607 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2608 for (tmp = skb->prev; \
2609 skb != (struct sk_buff *)(queue); \
2610 skb = tmp, tmp = skb->prev)
2612 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2614 return skb_shinfo(skb)->frag_list != NULL;
2617 static inline void skb_frag_list_init(struct sk_buff *skb)
2619 skb_shinfo(skb)->frag_list = NULL;
2622 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2624 frag->next = skb_shinfo(skb)->frag_list;
2625 skb_shinfo(skb)->frag_list = frag;
2628 #define skb_walk_frags(skb, iter) \
2629 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2631 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2632 int *peeked, int *off, int *err);
2633 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
2635 unsigned int datagram_poll(struct file *file, struct socket *sock,
2636 struct poll_table_struct *wait);
2637 int skb_copy_datagram_iovec(const struct sk_buff *from, int offset,
2638 struct iovec *to, int size);
2639 int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen,
2641 int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
2642 const struct iovec *from, int from_offset,
2644 int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
2645 int offset, size_t count);
2646 int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset,
2647 const struct iovec *to, int to_offset,
2649 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2650 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
2651 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
2652 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
2653 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
2654 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
2655 int len, __wsum csum);
2656 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
2657 struct pipe_inode_info *pipe, unsigned int len,
2658 unsigned int flags);
2659 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2660 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
2661 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
2663 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
2664 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
2665 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
2666 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
2667 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
2668 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
2670 struct skb_checksum_ops {
2671 __wsum (*update)(const void *mem, int len, __wsum wsum);
2672 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
2675 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
2676 __wsum csum, const struct skb_checksum_ops *ops);
2677 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
2680 static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
2681 int len, void *data, int hlen, void *buffer)
2683 if (hlen - offset >= len)
2684 return data + offset;
2687 skb_copy_bits(skb, offset, buffer, len) < 0)
2693 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2694 int len, void *buffer)
2696 return __skb_header_pointer(skb, offset, len, skb->data,
2697 skb_headlen(skb), buffer);
2701 * skb_needs_linearize - check if we need to linearize a given skb
2702 * depending on the given device features.
2703 * @skb: socket buffer to check
2704 * @features: net device features
2706 * Returns true if either:
2707 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2708 * 2. skb is fragmented and the device does not support SG.
2710 static inline bool skb_needs_linearize(struct sk_buff *skb,
2711 netdev_features_t features)
2713 return skb_is_nonlinear(skb) &&
2714 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
2715 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
2718 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2720 const unsigned int len)
2722 memcpy(to, skb->data, len);
2725 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2726 const int offset, void *to,
2727 const unsigned int len)
2729 memcpy(to, skb->data + offset, len);
2732 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2734 const unsigned int len)
2736 memcpy(skb->data, from, len);
2739 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2742 const unsigned int len)
2744 memcpy(skb->data + offset, from, len);
2747 void skb_init(void);
2749 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2755 * skb_get_timestamp - get timestamp from a skb
2756 * @skb: skb to get stamp from
2757 * @stamp: pointer to struct timeval to store stamp in
2759 * Timestamps are stored in the skb as offsets to a base timestamp.
2760 * This function converts the offset back to a struct timeval and stores
2763 static inline void skb_get_timestamp(const struct sk_buff *skb,
2764 struct timeval *stamp)
2766 *stamp = ktime_to_timeval(skb->tstamp);
2769 static inline void skb_get_timestampns(const struct sk_buff *skb,
2770 struct timespec *stamp)
2772 *stamp = ktime_to_timespec(skb->tstamp);
2775 static inline void __net_timestamp(struct sk_buff *skb)
2777 skb->tstamp = ktime_get_real();
2780 static inline ktime_t net_timedelta(ktime_t t)
2782 return ktime_sub(ktime_get_real(), t);
2785 static inline ktime_t net_invalid_timestamp(void)
2787 return ktime_set(0, 0);
2790 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
2792 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2794 void skb_clone_tx_timestamp(struct sk_buff *skb);
2795 bool skb_defer_rx_timestamp(struct sk_buff *skb);
2797 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2799 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2803 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2808 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2811 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2813 * PHY drivers may accept clones of transmitted packets for
2814 * timestamping via their phy_driver.txtstamp method. These drivers
2815 * must call this function to return the skb back to the stack, with
2816 * or without a timestamp.
2818 * @skb: clone of the the original outgoing packet
2819 * @hwtstamps: hardware time stamps, may be NULL if not available
2822 void skb_complete_tx_timestamp(struct sk_buff *skb,
2823 struct skb_shared_hwtstamps *hwtstamps);
2825 void __skb_tstamp_tx(struct sk_buff *orig_skb,
2826 struct skb_shared_hwtstamps *hwtstamps,
2827 struct sock *sk, int tstype);
2830 * skb_tstamp_tx - queue clone of skb with send time stamps
2831 * @orig_skb: the original outgoing packet
2832 * @hwtstamps: hardware time stamps, may be NULL if not available
2834 * If the skb has a socket associated, then this function clones the
2835 * skb (thus sharing the actual data and optional structures), stores
2836 * the optional hardware time stamping information (if non NULL) or
2837 * generates a software time stamp (otherwise), then queues the clone
2838 * to the error queue of the socket. Errors are silently ignored.
2840 void skb_tstamp_tx(struct sk_buff *orig_skb,
2841 struct skb_shared_hwtstamps *hwtstamps);
2843 static inline void sw_tx_timestamp(struct sk_buff *skb)
2845 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2846 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2847 skb_tstamp_tx(skb, NULL);
2851 * skb_tx_timestamp() - Driver hook for transmit timestamping
2853 * Ethernet MAC Drivers should call this function in their hard_xmit()
2854 * function immediately before giving the sk_buff to the MAC hardware.
2856 * Specifically, one should make absolutely sure that this function is
2857 * called before TX completion of this packet can trigger. Otherwise
2858 * the packet could potentially already be freed.
2860 * @skb: A socket buffer.
2862 static inline void skb_tx_timestamp(struct sk_buff *skb)
2864 skb_clone_tx_timestamp(skb);
2865 sw_tx_timestamp(skb);
2869 * skb_complete_wifi_ack - deliver skb with wifi status
2871 * @skb: the original outgoing packet
2872 * @acked: ack status
2875 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2877 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2878 __sum16 __skb_checksum_complete(struct sk_buff *skb);
2880 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2882 return ((skb->ip_summed & CHECKSUM_UNNECESSARY) || skb->csum_valid);
2886 * skb_checksum_complete - Calculate checksum of an entire packet
2887 * @skb: packet to process
2889 * This function calculates the checksum over the entire packet plus
2890 * the value of skb->csum. The latter can be used to supply the
2891 * checksum of a pseudo header as used by TCP/UDP. It returns the
2894 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2895 * this function can be used to verify that checksum on received
2896 * packets. In that case the function should return zero if the
2897 * checksum is correct. In particular, this function will return zero
2898 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2899 * hardware has already verified the correctness of the checksum.
2901 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2903 return skb_csum_unnecessary(skb) ?
2904 0 : __skb_checksum_complete(skb);
2907 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
2909 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2910 if (skb->csum_level == 0)
2911 skb->ip_summed = CHECKSUM_NONE;
2917 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
2919 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2920 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
2922 } else if (skb->ip_summed == CHECKSUM_NONE) {
2923 skb->ip_summed = CHECKSUM_UNNECESSARY;
2924 skb->csum_level = 0;
2928 static inline void __skb_mark_checksum_bad(struct sk_buff *skb)
2930 /* Mark current checksum as bad (typically called from GRO
2931 * path). In the case that ip_summed is CHECKSUM_NONE
2932 * this must be the first checksum encountered in the packet.
2933 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
2934 * checksum after the last one validated. For UDP, a zero
2935 * checksum can not be marked as bad.
2938 if (skb->ip_summed == CHECKSUM_NONE ||
2939 skb->ip_summed == CHECKSUM_UNNECESSARY)
2943 /* Check if we need to perform checksum complete validation.
2945 * Returns true if checksum complete is needed, false otherwise
2946 * (either checksum is unnecessary or zero checksum is allowed).
2948 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
2952 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
2953 skb->csum_valid = 1;
2954 __skb_decr_checksum_unnecessary(skb);
2961 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
2964 #define CHECKSUM_BREAK 76
2966 /* Unset checksum-complete
2968 * Unset checksum complete can be done when packet is being modified
2969 * (uncompressed for instance) and checksum-complete value is
2972 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
2974 if (skb->ip_summed == CHECKSUM_COMPLETE)
2975 skb->ip_summed = CHECKSUM_NONE;
2978 /* Validate (init) checksum based on checksum complete.
2981 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
2982 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
2983 * checksum is stored in skb->csum for use in __skb_checksum_complete
2984 * non-zero: value of invalid checksum
2987 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
2991 if (skb->ip_summed == CHECKSUM_COMPLETE) {
2992 if (!csum_fold(csum_add(psum, skb->csum))) {
2993 skb->csum_valid = 1;
2996 } else if (skb->csum_bad) {
2997 /* ip_summed == CHECKSUM_NONE in this case */
3003 if (complete || skb->len <= CHECKSUM_BREAK) {
3006 csum = __skb_checksum_complete(skb);
3007 skb->csum_valid = !csum;
3014 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
3019 /* Perform checksum validate (init). Note that this is a macro since we only
3020 * want to calculate the pseudo header which is an input function if necessary.
3021 * First we try to validate without any computation (checksum unnecessary) and
3022 * then calculate based on checksum complete calling the function to compute
3026 * 0: checksum is validated or try to in skb_checksum_complete
3027 * non-zero: value of invalid checksum
3029 #define __skb_checksum_validate(skb, proto, complete, \
3030 zero_okay, check, compute_pseudo) \
3032 __sum16 __ret = 0; \
3033 skb->csum_valid = 0; \
3034 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3035 __ret = __skb_checksum_validate_complete(skb, \
3036 complete, compute_pseudo(skb, proto)); \
3040 #define skb_checksum_init(skb, proto, compute_pseudo) \
3041 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3043 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3044 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3046 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3047 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3049 #define skb_checksum_validate_zero_check(skb, proto, check, \
3051 __skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo)
3053 #define skb_checksum_simple_validate(skb) \
3054 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3056 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
3058 return (skb->ip_summed == CHECKSUM_NONE &&
3059 skb->csum_valid && !skb->csum_bad);
3062 static inline void __skb_checksum_convert(struct sk_buff *skb,
3063 __sum16 check, __wsum pseudo)
3065 skb->csum = ~pseudo;
3066 skb->ip_summed = CHECKSUM_COMPLETE;
3069 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3071 if (__skb_checksum_convert_check(skb)) \
3072 __skb_checksum_convert(skb, check, \
3073 compute_pseudo(skb, proto)); \
3076 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3077 void nf_conntrack_destroy(struct nf_conntrack *nfct);
3078 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
3080 if (nfct && atomic_dec_and_test(&nfct->use))
3081 nf_conntrack_destroy(nfct);
3083 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
3086 atomic_inc(&nfct->use);
3089 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3090 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
3092 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
3095 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
3098 atomic_inc(&nf_bridge->use);
3100 #endif /* CONFIG_BRIDGE_NETFILTER */
3101 static inline void nf_reset(struct sk_buff *skb)
3103 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3104 nf_conntrack_put(skb->nfct);
3107 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3108 nf_bridge_put(skb->nf_bridge);
3109 skb->nf_bridge = NULL;
3113 static inline void nf_reset_trace(struct sk_buff *skb)
3115 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3120 static inline void ipvs_reset(struct sk_buff *skb)
3122 #if IS_ENABLED(CONFIG_IP_VS)
3123 skb->ipvs_property = 0;
3127 /* Note: This doesn't put any conntrack and bridge info in dst. */
3128 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
3131 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3132 dst->nfct = src->nfct;
3133 nf_conntrack_get(src->nfct);
3135 dst->nfctinfo = src->nfctinfo;
3137 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3138 dst->nf_bridge = src->nf_bridge;
3139 nf_bridge_get(src->nf_bridge);
3141 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3143 dst->nf_trace = src->nf_trace;
3147 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
3149 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3150 nf_conntrack_put(dst->nfct);
3152 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3153 nf_bridge_put(dst->nf_bridge);
3155 __nf_copy(dst, src, true);
3158 #ifdef CONFIG_NETWORK_SECMARK
3159 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3161 to->secmark = from->secmark;
3164 static inline void skb_init_secmark(struct sk_buff *skb)
3169 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3172 static inline void skb_init_secmark(struct sk_buff *skb)
3176 static inline bool skb_irq_freeable(const struct sk_buff *skb)
3178 return !skb->destructor &&
3179 #if IS_ENABLED(CONFIG_XFRM)
3182 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3185 !skb->_skb_refdst &&
3186 !skb_has_frag_list(skb);
3189 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
3191 skb->queue_mapping = queue_mapping;
3194 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
3196 return skb->queue_mapping;
3199 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
3201 to->queue_mapping = from->queue_mapping;
3204 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
3206 skb->queue_mapping = rx_queue + 1;
3209 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
3211 return skb->queue_mapping - 1;
3214 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
3216 return skb->queue_mapping != 0;
3219 u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
3220 unsigned int num_tx_queues);
3222 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
3231 /* Keeps track of mac header offset relative to skb->head.
3232 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3233 * For non-tunnel skb it points to skb_mac_header() and for
3234 * tunnel skb it points to outer mac header.
3235 * Keeps track of level of encapsulation of network headers.
3242 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3244 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
3246 return (skb_mac_header(inner_skb) - inner_skb->head) -
3247 SKB_GSO_CB(inner_skb)->mac_offset;
3250 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
3252 int new_headroom, headroom;
3255 headroom = skb_headroom(skb);
3256 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
3260 new_headroom = skb_headroom(skb);
3261 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
3265 /* Compute the checksum for a gso segment. First compute the checksum value
3266 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3267 * then add in skb->csum (checksum from csum_start to end of packet).
3268 * skb->csum and csum_start are then updated to reflect the checksum of the
3269 * resultant packet starting from the transport header-- the resultant checksum
3270 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3273 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
3275 int plen = SKB_GSO_CB(skb)->csum_start - skb_headroom(skb) -
3276 skb_transport_offset(skb);
3279 csum = csum_fold(csum_partial(skb_transport_header(skb),
3282 SKB_GSO_CB(skb)->csum_start -= plen;
3287 static inline bool skb_is_gso(const struct sk_buff *skb)
3289 return skb_shinfo(skb)->gso_size;
3292 /* Note: Should be called only if skb_is_gso(skb) is true */
3293 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
3295 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
3298 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
3300 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
3302 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3303 * wanted then gso_type will be set. */
3304 const struct skb_shared_info *shinfo = skb_shinfo(skb);
3306 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
3307 unlikely(shinfo->gso_type == 0)) {
3308 __skb_warn_lro_forwarding(skb);
3314 static inline void skb_forward_csum(struct sk_buff *skb)
3316 /* Unfortunately we don't support this one. Any brave souls? */
3317 if (skb->ip_summed == CHECKSUM_COMPLETE)
3318 skb->ip_summed = CHECKSUM_NONE;
3322 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3323 * @skb: skb to check
3325 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3326 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3327 * use this helper, to document places where we make this assertion.
3329 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
3332 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
3336 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
3338 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
3340 u32 skb_get_poff(const struct sk_buff *skb);
3341 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
3342 const struct flow_keys *keys, int hlen);
3345 * skb_head_is_locked - Determine if the skb->head is locked down
3346 * @skb: skb to check
3348 * The head on skbs build around a head frag can be removed if they are
3349 * not cloned. This function returns true if the skb head is locked down
3350 * due to either being allocated via kmalloc, or by being a clone with
3351 * multiple references to the head.
3353 static inline bool skb_head_is_locked(const struct sk_buff *skb)
3355 return !skb->head_frag || skb_cloned(skb);
3359 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3363 * skb_gso_network_seglen is used to determine the real size of the
3364 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3366 * The MAC/L2 header is not accounted for.
3368 static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
3370 unsigned int hdr_len = skb_transport_header(skb) -
3371 skb_network_header(skb);
3372 return hdr_len + skb_gso_transport_seglen(skb);
3374 #endif /* __KERNEL__ */
3375 #endif /* _LINUX_SKBUFF_H */