2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
23 #include <linux/rbtree.h>
24 #include <linux/socket.h>
26 #include <linux/atomic.h>
27 #include <asm/types.h>
28 #include <linux/spinlock.h>
29 #include <linux/net.h>
30 #include <linux/textsearch.h>
31 #include <net/checksum.h>
32 #include <linux/rcupdate.h>
33 #include <linux/hrtimer.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/netdev_features.h>
36 #include <linux/sched.h>
37 #include <net/flow_keys.h>
39 /* A. Checksumming of received packets by device.
43 * Device failed to checksum this packet e.g. due to lack of capabilities.
44 * The packet contains full (though not verified) checksum in packet but
45 * not in skb->csum. Thus, skb->csum is undefined in this case.
47 * CHECKSUM_UNNECESSARY:
49 * The hardware you're dealing with doesn't calculate the full checksum
50 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
51 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
52 * if their checksums are okay. skb->csum is still undefined in this case
53 * though. It is a bad option, but, unfortunately, nowadays most vendors do
54 * this. Apparently with the secret goal to sell you new devices, when you
55 * will add new protocol to your host, f.e. IPv6 8)
57 * CHECKSUM_UNNECESSARY is applicable to following protocols:
59 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
60 * zero UDP checksum for either IPv4 or IPv6, the networking stack
61 * may perform further validation in this case.
62 * GRE: only if the checksum is present in the header.
63 * SCTP: indicates the CRC in SCTP header has been validated.
65 * skb->csum_level indicates the number of consecutive checksums found in
66 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
67 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
68 * and a device is able to verify the checksums for UDP (possibly zero),
69 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
70 * two. If the device were only able to verify the UDP checksum and not
71 * GRE, either because it doesn't support GRE checksum of because GRE
72 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
73 * not considered in this case).
77 * This is the most generic way. The device supplied checksum of the _whole_
78 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
79 * hardware doesn't need to parse L3/L4 headers to implement this.
81 * Note: Even if device supports only some protocols, but is able to produce
82 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
86 * A checksum is set up to be offloaded to a device as described in the
87 * output description for CHECKSUM_PARTIAL. This may occur on a packet
88 * received directly from another Linux OS, e.g., a virtualized Linux kernel
89 * on the same host, or it may be set in the input path in GRO or remote
90 * checksum offload. For the purposes of checksum verification, the checksum
91 * referred to by skb->csum_start + skb->csum_offset and any preceding
92 * checksums in the packet are considered verified. Any checksums in the
93 * packet that are after the checksum being offloaded are not considered to
96 * B. Checksumming on output.
100 * The skb was already checksummed by the protocol, or a checksum is not
105 * The device is required to checksum the packet as seen by hard_start_xmit()
106 * from skb->csum_start up to the end, and to record/write the checksum at
107 * offset skb->csum_start + skb->csum_offset.
109 * The device must show its capabilities in dev->features, set up at device
110 * setup time, e.g. netdev_features.h:
112 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
113 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
114 * IPv4. Sigh. Vendors like this way for an unknown reason.
115 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
116 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
117 * NETIF_F_... - Well, you get the picture.
119 * CHECKSUM_UNNECESSARY:
121 * Normally, the device will do per protocol specific checksumming. Protocol
122 * implementations that do not want the NIC to perform the checksum
123 * calculation should use this flag in their outgoing skbs.
125 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
126 * offload. Correspondingly, the FCoE protocol driver
127 * stack should use CHECKSUM_UNNECESSARY.
129 * Any questions? No questions, good. --ANK
132 /* Don't change this without changing skb_csum_unnecessary! */
133 #define CHECKSUM_NONE 0
134 #define CHECKSUM_UNNECESSARY 1
135 #define CHECKSUM_COMPLETE 2
136 #define CHECKSUM_PARTIAL 3
138 /* Maximum value in skb->csum_level */
139 #define SKB_MAX_CSUM_LEVEL 3
141 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
142 #define SKB_WITH_OVERHEAD(X) \
143 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
144 #define SKB_MAX_ORDER(X, ORDER) \
145 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
146 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
147 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
149 /* return minimum truesize of one skb containing X bytes of data */
150 #define SKB_TRUESIZE(X) ((X) + \
151 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
152 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
156 struct pipe_inode_info
;
160 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
161 struct nf_conntrack
{
166 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
167 struct nf_bridge_info
{
170 BRNF_PROTO_UNCHANGED
,
176 struct net_device
*physindev
;
177 struct net_device
*physoutdev
;
178 char neigh_header
[8];
182 struct sk_buff_head
{
183 /* These two members must be first. */
184 struct sk_buff
*next
;
185 struct sk_buff
*prev
;
193 /* To allow 64K frame to be packed as single skb without frag_list we
194 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
195 * buffers which do not start on a page boundary.
197 * Since GRO uses frags we allocate at least 16 regardless of page
200 #if (65536/PAGE_SIZE + 1) < 16
201 #define MAX_SKB_FRAGS 16UL
203 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
206 typedef struct skb_frag_struct skb_frag_t
;
208 struct skb_frag_struct
{
212 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
221 static inline unsigned int skb_frag_size(const skb_frag_t
*frag
)
226 static inline void skb_frag_size_set(skb_frag_t
*frag
, unsigned int size
)
231 static inline void skb_frag_size_add(skb_frag_t
*frag
, int delta
)
236 static inline void skb_frag_size_sub(skb_frag_t
*frag
, int delta
)
241 #define HAVE_HW_TIME_STAMP
244 * struct skb_shared_hwtstamps - hardware time stamps
245 * @hwtstamp: hardware time stamp transformed into duration
246 * since arbitrary point in time
248 * Software time stamps generated by ktime_get_real() are stored in
251 * hwtstamps can only be compared against other hwtstamps from
254 * This structure is attached to packets as part of the
255 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
257 struct skb_shared_hwtstamps
{
261 /* Definitions for tx_flags in struct skb_shared_info */
263 /* generate hardware time stamp */
264 SKBTX_HW_TSTAMP
= 1 << 0,
266 /* generate software time stamp when queueing packet to NIC */
267 SKBTX_SW_TSTAMP
= 1 << 1,
269 /* device driver is going to provide hardware time stamp */
270 SKBTX_IN_PROGRESS
= 1 << 2,
272 /* device driver supports TX zero-copy buffers */
273 SKBTX_DEV_ZEROCOPY
= 1 << 3,
275 /* generate wifi status information (where possible) */
276 SKBTX_WIFI_STATUS
= 1 << 4,
278 /* This indicates at least one fragment might be overwritten
279 * (as in vmsplice(), sendfile() ...)
280 * If we need to compute a TX checksum, we'll need to copy
281 * all frags to avoid possible bad checksum
283 SKBTX_SHARED_FRAG
= 1 << 5,
285 /* generate software time stamp when entering packet scheduling */
286 SKBTX_SCHED_TSTAMP
= 1 << 6,
288 /* generate software timestamp on peer data acknowledgment */
289 SKBTX_ACK_TSTAMP
= 1 << 7,
292 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
293 SKBTX_SCHED_TSTAMP | \
295 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
298 * The callback notifies userspace to release buffers when skb DMA is done in
299 * lower device, the skb last reference should be 0 when calling this.
300 * The zerocopy_success argument is true if zero copy transmit occurred,
301 * false on data copy or out of memory error caused by data copy attempt.
302 * The ctx field is used to track device context.
303 * The desc field is used to track userspace buffer index.
306 void (*callback
)(struct ubuf_info
*, bool zerocopy_success
);
311 /* This data is invariant across clones and lives at
312 * the end of the header data, ie. at skb->end.
314 struct skb_shared_info
{
315 unsigned char nr_frags
;
317 unsigned short gso_size
;
318 /* Warning: this field is not always filled in (UFO)! */
319 unsigned short gso_segs
;
320 unsigned short gso_type
;
321 struct sk_buff
*frag_list
;
322 struct skb_shared_hwtstamps hwtstamps
;
327 * Warning : all fields before dataref are cleared in __alloc_skb()
331 /* Intermediate layers must ensure that destructor_arg
332 * remains valid until skb destructor */
333 void * destructor_arg
;
335 /* must be last field, see pskb_expand_head() */
336 skb_frag_t frags
[MAX_SKB_FRAGS
];
339 /* We divide dataref into two halves. The higher 16 bits hold references
340 * to the payload part of skb->data. The lower 16 bits hold references to
341 * the entire skb->data. A clone of a headerless skb holds the length of
342 * the header in skb->hdr_len.
344 * All users must obey the rule that the skb->data reference count must be
345 * greater than or equal to the payload reference count.
347 * Holding a reference to the payload part means that the user does not
348 * care about modifications to the header part of skb->data.
350 #define SKB_DATAREF_SHIFT 16
351 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
355 SKB_FCLONE_UNAVAILABLE
, /* skb has no fclone (from head_cache) */
356 SKB_FCLONE_ORIG
, /* orig skb (from fclone_cache) */
357 SKB_FCLONE_CLONE
, /* companion fclone skb (from fclone_cache) */
361 SKB_GSO_TCPV4
= 1 << 0,
362 SKB_GSO_UDP
= 1 << 1,
364 /* This indicates the skb is from an untrusted source. */
365 SKB_GSO_DODGY
= 1 << 2,
367 /* This indicates the tcp segment has CWR set. */
368 SKB_GSO_TCP_ECN
= 1 << 3,
370 SKB_GSO_TCPV6
= 1 << 4,
372 SKB_GSO_FCOE
= 1 << 5,
374 SKB_GSO_GRE
= 1 << 6,
376 SKB_GSO_GRE_CSUM
= 1 << 7,
378 SKB_GSO_IPIP
= 1 << 8,
380 SKB_GSO_SIT
= 1 << 9,
382 SKB_GSO_UDP_TUNNEL
= 1 << 10,
384 SKB_GSO_UDP_TUNNEL_CSUM
= 1 << 11,
386 SKB_GSO_TUNNEL_REMCSUM
= 1 << 12,
389 #if BITS_PER_LONG > 32
390 #define NET_SKBUFF_DATA_USES_OFFSET 1
393 #ifdef NET_SKBUFF_DATA_USES_OFFSET
394 typedef unsigned int sk_buff_data_t
;
396 typedef unsigned char *sk_buff_data_t
;
400 * struct skb_mstamp - multi resolution time stamps
401 * @stamp_us: timestamp in us resolution
402 * @stamp_jiffies: timestamp in jiffies
415 * skb_mstamp_get - get current timestamp
416 * @cl: place to store timestamps
418 static inline void skb_mstamp_get(struct skb_mstamp
*cl
)
420 u64 val
= local_clock();
422 do_div(val
, NSEC_PER_USEC
);
423 cl
->stamp_us
= (u32
)val
;
424 cl
->stamp_jiffies
= (u32
)jiffies
;
428 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
429 * @t1: pointer to newest sample
430 * @t0: pointer to oldest sample
432 static inline u32
skb_mstamp_us_delta(const struct skb_mstamp
*t1
,
433 const struct skb_mstamp
*t0
)
435 s32 delta_us
= t1
->stamp_us
- t0
->stamp_us
;
436 u32 delta_jiffies
= t1
->stamp_jiffies
- t0
->stamp_jiffies
;
438 /* If delta_us is negative, this might be because interval is too big,
439 * or local_clock() drift is too big : fallback using jiffies.
442 delta_jiffies
>= (INT_MAX
/ (USEC_PER_SEC
/ HZ
)))
444 delta_us
= jiffies_to_usecs(delta_jiffies
);
451 * struct sk_buff - socket buffer
452 * @next: Next buffer in list
453 * @prev: Previous buffer in list
454 * @tstamp: Time we arrived/left
455 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
456 * @sk: Socket we are owned by
457 * @dev: Device we arrived on/are leaving by
458 * @cb: Control buffer. Free for use by every layer. Put private vars here
459 * @_skb_refdst: destination entry (with norefcount bit)
460 * @sp: the security path, used for xfrm
461 * @len: Length of actual data
462 * @data_len: Data length
463 * @mac_len: Length of link layer header
464 * @hdr_len: writable header length of cloned skb
465 * @csum: Checksum (must include start/offset pair)
466 * @csum_start: Offset from skb->head where checksumming should start
467 * @csum_offset: Offset from csum_start where checksum should be stored
468 * @priority: Packet queueing priority
469 * @ignore_df: allow local fragmentation
470 * @cloned: Head may be cloned (check refcnt to be sure)
471 * @ip_summed: Driver fed us an IP checksum
472 * @nohdr: Payload reference only, must not modify header
473 * @nfctinfo: Relationship of this skb to the connection
474 * @pkt_type: Packet class
475 * @fclone: skbuff clone status
476 * @ipvs_property: skbuff is owned by ipvs
477 * @peeked: this packet has been seen already, so stats have been
478 * done for it, don't do them again
479 * @nf_trace: netfilter packet trace flag
480 * @protocol: Packet protocol from driver
481 * @destructor: Destruct function
482 * @nfct: Associated connection, if any
483 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
484 * @skb_iif: ifindex of device we arrived on
485 * @tc_index: Traffic control index
486 * @tc_verd: traffic control verdict
487 * @hash: the packet hash
488 * @queue_mapping: Queue mapping for multiqueue devices
489 * @xmit_more: More SKBs are pending for this queue
490 * @ndisc_nodetype: router type (from link layer)
491 * @ooo_okay: allow the mapping of a socket to a queue to be changed
492 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
494 * @sw_hash: indicates hash was computed in software stack
495 * @wifi_acked_valid: wifi_acked was set
496 * @wifi_acked: whether frame was acked on wifi or not
497 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
498 * @napi_id: id of the NAPI struct this skb came from
499 * @secmark: security marking
500 * @mark: Generic packet mark
501 * @vlan_proto: vlan encapsulation protocol
502 * @vlan_tci: vlan tag control information
503 * @inner_protocol: Protocol (encapsulation)
504 * @inner_transport_header: Inner transport layer header (encapsulation)
505 * @inner_network_header: Network layer header (encapsulation)
506 * @inner_mac_header: Link layer header (encapsulation)
507 * @transport_header: Transport layer header
508 * @network_header: Network layer header
509 * @mac_header: Link layer header
510 * @tail: Tail pointer
512 * @head: Head of buffer
513 * @data: Data head pointer
514 * @truesize: Buffer size
515 * @users: User count - see {datagram,tcp}.c
521 /* These two members must be first. */
522 struct sk_buff
*next
;
523 struct sk_buff
*prev
;
527 struct skb_mstamp skb_mstamp
;
530 struct rb_node rbnode
; /* used in netem & tcp stack */
533 struct net_device
*dev
;
536 * This is the control buffer. It is free to use for every
537 * layer. Please put your private variables there. If you
538 * want to keep them across layers you have to do a skb_clone()
539 * first. This is owned by whoever has the skb queued ATM.
541 char cb
[48] __aligned(8);
543 unsigned long _skb_refdst
;
544 void (*destructor
)(struct sk_buff
*skb
);
548 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
549 struct nf_conntrack
*nfct
;
551 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
552 struct nf_bridge_info
*nf_bridge
;
559 /* Following fields are _not_ copied in __copy_skb_header()
560 * Note that queue_mapping is here mostly to fill a hole.
562 kmemcheck_bitfield_begin(flags1
);
571 kmemcheck_bitfield_end(flags1
);
573 /* fields enclosed in headers_start/headers_end are copied
574 * using a single memcpy() in __copy_skb_header()
577 __u32 headers_start
[0];
580 /* if you move pkt_type around you also must adapt those constants */
581 #ifdef __BIG_ENDIAN_BITFIELD
582 #define PKT_TYPE_MAX (7 << 5)
584 #define PKT_TYPE_MAX 7
586 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
588 __u8 __pkt_type_offset
[0];
599 __u8 wifi_acked_valid
:1;
603 /* Indicates the inner headers are valid in the skbuff. */
604 __u8 encapsulation
:1;
605 __u8 encap_hdr_csum
:1;
607 __u8 csum_complete_sw
:1;
611 #ifdef CONFIG_IPV6_NDISC_NODETYPE
612 __u8 ndisc_nodetype
:2;
614 __u8 ipvs_property
:1;
615 __u8 inner_protocol_type
:1;
616 __u8 remcsum_offload
:1;
617 /* 3 or 5 bit hole */
619 #ifdef CONFIG_NET_SCHED
620 __u16 tc_index
; /* traffic control index */
621 #ifdef CONFIG_NET_CLS_ACT
622 __u16 tc_verd
; /* traffic control verdict */
638 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
640 unsigned int napi_id
;
641 unsigned int sender_cpu
;
644 #ifdef CONFIG_NETWORK_SECMARK
649 __u32 reserved_tailroom
;
653 __be16 inner_protocol
;
657 __u16 inner_transport_header
;
658 __u16 inner_network_header
;
659 __u16 inner_mac_header
;
662 __u16 transport_header
;
663 __u16 network_header
;
667 __u32 headers_end
[0];
670 /* These elements must be at the end, see alloc_skb() for details. */
675 unsigned int truesize
;
681 * Handling routines are only of interest to the kernel
683 #include <linux/slab.h>
686 #define SKB_ALLOC_FCLONE 0x01
687 #define SKB_ALLOC_RX 0x02
688 #define SKB_ALLOC_NAPI 0x04
690 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
691 static inline bool skb_pfmemalloc(const struct sk_buff
*skb
)
693 return unlikely(skb
->pfmemalloc
);
697 * skb might have a dst pointer attached, refcounted or not.
698 * _skb_refdst low order bit is set if refcount was _not_ taken
700 #define SKB_DST_NOREF 1UL
701 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
704 * skb_dst - returns skb dst_entry
707 * Returns skb dst_entry, regardless of reference taken or not.
709 static inline struct dst_entry
*skb_dst(const struct sk_buff
*skb
)
711 /* If refdst was not refcounted, check we still are in a
712 * rcu_read_lock section
714 WARN_ON((skb
->_skb_refdst
& SKB_DST_NOREF
) &&
715 !rcu_read_lock_held() &&
716 !rcu_read_lock_bh_held());
717 return (struct dst_entry
*)(skb
->_skb_refdst
& SKB_DST_PTRMASK
);
721 * skb_dst_set - sets skb dst
725 * Sets skb dst, assuming a reference was taken on dst and should
726 * be released by skb_dst_drop()
728 static inline void skb_dst_set(struct sk_buff
*skb
, struct dst_entry
*dst
)
730 skb
->_skb_refdst
= (unsigned long)dst
;
734 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
738 * Sets skb dst, assuming a reference was not taken on dst.
739 * If dst entry is cached, we do not take reference and dst_release
740 * will be avoided by refdst_drop. If dst entry is not cached, we take
741 * reference, so that last dst_release can destroy the dst immediately.
743 static inline void skb_dst_set_noref(struct sk_buff
*skb
, struct dst_entry
*dst
)
745 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
746 skb
->_skb_refdst
= (unsigned long)dst
| SKB_DST_NOREF
;
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 atomic_read(&fclones
->fclone_ref
) > 1 &&
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
);
881 * Packet hash types specify the type of hash in skb_set_hash.
883 * Hash types refer to the protocol layer addresses which are used to
884 * construct a packet's hash. The hashes are used to differentiate or identify
885 * flows of the protocol layer for the hash type. Hash types are either
886 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
888 * Properties of hashes:
890 * 1) Two packets in different flows have different hash values
891 * 2) Two packets in the same flow should have the same hash value
893 * A hash at a higher layer is considered to be more specific. A driver should
894 * set the most specific hash possible.
896 * A driver cannot indicate a more specific hash than the layer at which a hash
897 * was computed. For instance an L3 hash cannot be set as an L4 hash.
899 * A driver may indicate a hash level which is less specific than the
900 * actual layer the hash was computed on. For instance, a hash computed
901 * at L4 may be considered an L3 hash. This should only be done if the
902 * driver can't unambiguously determine that the HW computed the hash at
903 * the higher layer. Note that the "should" in the second property above
906 enum pkt_hash_types
{
907 PKT_HASH_TYPE_NONE
, /* Undefined type */
908 PKT_HASH_TYPE_L2
, /* Input: src_MAC, dest_MAC */
909 PKT_HASH_TYPE_L3
, /* Input: src_IP, dst_IP */
910 PKT_HASH_TYPE_L4
, /* Input: src_IP, dst_IP, src_port, dst_port */
914 skb_set_hash(struct sk_buff
*skb
, __u32 hash
, enum pkt_hash_types type
)
916 skb
->l4_hash
= (type
== PKT_HASH_TYPE_L4
);
921 void __skb_get_hash(struct sk_buff
*skb
);
922 static inline __u32
skb_get_hash(struct sk_buff
*skb
)
924 if (!skb
->l4_hash
&& !skb
->sw_hash
)
930 static inline __u32
skb_get_hash_raw(const struct sk_buff
*skb
)
935 static inline void skb_clear_hash(struct sk_buff
*skb
)
942 static inline void skb_clear_hash_if_not_l4(struct sk_buff
*skb
)
948 static inline void skb_copy_hash(struct sk_buff
*to
, const struct sk_buff
*from
)
950 to
->hash
= from
->hash
;
951 to
->sw_hash
= from
->sw_hash
;
952 to
->l4_hash
= from
->l4_hash
;
955 static inline void skb_sender_cpu_clear(struct sk_buff
*skb
)
962 #ifdef NET_SKBUFF_DATA_USES_OFFSET
963 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
965 return skb
->head
+ skb
->end
;
968 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
973 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
978 static inline unsigned int skb_end_offset(const struct sk_buff
*skb
)
980 return skb
->end
- skb
->head
;
985 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
987 static inline struct skb_shared_hwtstamps
*skb_hwtstamps(struct sk_buff
*skb
)
989 return &skb_shinfo(skb
)->hwtstamps
;
993 * skb_queue_empty - check if a queue is empty
996 * Returns true if the queue is empty, false otherwise.
998 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
1000 return list
->next
== (const struct sk_buff
*) list
;
1004 * skb_queue_is_last - check if skb is the last entry in the queue
1008 * Returns true if @skb is the last buffer on the list.
1010 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
1011 const struct sk_buff
*skb
)
1013 return skb
->next
== (const struct sk_buff
*) list
;
1017 * skb_queue_is_first - check if skb is the first entry in the queue
1021 * Returns true if @skb is the first buffer on the list.
1023 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
1024 const struct sk_buff
*skb
)
1026 return skb
->prev
== (const struct sk_buff
*) list
;
1030 * skb_queue_next - return the next packet in the queue
1032 * @skb: current buffer
1034 * Return the next packet in @list after @skb. It is only valid to
1035 * call this if skb_queue_is_last() evaluates to false.
1037 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
1038 const struct sk_buff
*skb
)
1040 /* This BUG_ON may seem severe, but if we just return then we
1041 * are going to dereference garbage.
1043 BUG_ON(skb_queue_is_last(list
, skb
));
1048 * skb_queue_prev - return the prev packet in the queue
1050 * @skb: current buffer
1052 * Return the prev packet in @list before @skb. It is only valid to
1053 * call this if skb_queue_is_first() evaluates to false.
1055 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
1056 const struct sk_buff
*skb
)
1058 /* This BUG_ON may seem severe, but if we just return then we
1059 * are going to dereference garbage.
1061 BUG_ON(skb_queue_is_first(list
, skb
));
1066 * skb_get - reference buffer
1067 * @skb: buffer to reference
1069 * Makes another reference to a socket buffer and returns a pointer
1072 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
1074 atomic_inc(&skb
->users
);
1079 * If users == 1, we are the only owner and are can avoid redundant
1084 * skb_cloned - is the buffer a clone
1085 * @skb: buffer to check
1087 * Returns true if the buffer was generated with skb_clone() and is
1088 * one of multiple shared copies of the buffer. Cloned buffers are
1089 * shared data so must not be written to under normal circumstances.
1091 static inline int skb_cloned(const struct sk_buff
*skb
)
1093 return skb
->cloned
&&
1094 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
1097 static inline int skb_unclone(struct sk_buff
*skb
, gfp_t pri
)
1099 might_sleep_if(pri
& __GFP_WAIT
);
1101 if (skb_cloned(skb
))
1102 return pskb_expand_head(skb
, 0, 0, pri
);
1108 * skb_header_cloned - is the header a clone
1109 * @skb: buffer to check
1111 * Returns true if modifying the header part of the buffer requires
1112 * the data to be copied.
1114 static inline int skb_header_cloned(const struct sk_buff
*skb
)
1121 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
1122 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
1123 return dataref
!= 1;
1127 * skb_header_release - release reference to header
1128 * @skb: buffer to operate on
1130 * Drop a reference to the header part of the buffer. This is done
1131 * by acquiring a payload reference. You must not read from the header
1132 * part of skb->data after this.
1133 * Note : Check if you can use __skb_header_release() instead.
1135 static inline void skb_header_release(struct sk_buff
*skb
)
1139 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
1143 * __skb_header_release - release reference to header
1144 * @skb: buffer to operate on
1146 * Variant of skb_header_release() assuming skb is private to caller.
1147 * We can avoid one atomic operation.
1149 static inline void __skb_header_release(struct sk_buff
*skb
)
1152 atomic_set(&skb_shinfo(skb
)->dataref
, 1 + (1 << SKB_DATAREF_SHIFT
));
1157 * skb_shared - is the buffer shared
1158 * @skb: buffer to check
1160 * Returns true if more than one person has a reference to this
1163 static inline int skb_shared(const struct sk_buff
*skb
)
1165 return atomic_read(&skb
->users
) != 1;
1169 * skb_share_check - check if buffer is shared and if so clone it
1170 * @skb: buffer to check
1171 * @pri: priority for memory allocation
1173 * If the buffer is shared the buffer is cloned and the old copy
1174 * drops a reference. A new clone with a single reference is returned.
1175 * If the buffer is not shared the original buffer is returned. When
1176 * being called from interrupt status or with spinlocks held pri must
1179 * NULL is returned on a memory allocation failure.
1181 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
, gfp_t pri
)
1183 might_sleep_if(pri
& __GFP_WAIT
);
1184 if (skb_shared(skb
)) {
1185 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
1197 * Copy shared buffers into a new sk_buff. We effectively do COW on
1198 * packets to handle cases where we have a local reader and forward
1199 * and a couple of other messy ones. The normal one is tcpdumping
1200 * a packet thats being forwarded.
1204 * skb_unshare - make a copy of a shared buffer
1205 * @skb: buffer to check
1206 * @pri: priority for memory allocation
1208 * If the socket buffer is a clone then this function creates a new
1209 * copy of the data, drops a reference count on the old copy and returns
1210 * the new copy with the reference count at 1. If the buffer is not a clone
1211 * the original buffer is returned. When called with a spinlock held or
1212 * from interrupt state @pri must be %GFP_ATOMIC
1214 * %NULL is returned on a memory allocation failure.
1216 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
1219 might_sleep_if(pri
& __GFP_WAIT
);
1220 if (skb_cloned(skb
)) {
1221 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
1223 /* Free our shared copy */
1234 * skb_peek - peek at the head of an &sk_buff_head
1235 * @list_: list to peek at
1237 * Peek an &sk_buff. Unlike most other operations you _MUST_
1238 * be careful with this one. A peek leaves the buffer on the
1239 * list and someone else may run off with it. You must hold
1240 * the appropriate locks or have a private queue to do this.
1242 * Returns %NULL for an empty list or a pointer to the head element.
1243 * The reference count is not incremented and the reference is therefore
1244 * volatile. Use with caution.
1246 static inline struct sk_buff
*skb_peek(const struct sk_buff_head
*list_
)
1248 struct sk_buff
*skb
= list_
->next
;
1250 if (skb
== (struct sk_buff
*)list_
)
1256 * skb_peek_next - peek skb following the given one from a queue
1257 * @skb: skb to start from
1258 * @list_: list to peek at
1260 * Returns %NULL when the end of the list is met or a pointer to the
1261 * next element. The reference count is not incremented and the
1262 * reference is therefore volatile. Use with caution.
1264 static inline struct sk_buff
*skb_peek_next(struct sk_buff
*skb
,
1265 const struct sk_buff_head
*list_
)
1267 struct sk_buff
*next
= skb
->next
;
1269 if (next
== (struct sk_buff
*)list_
)
1275 * skb_peek_tail - peek at the tail of an &sk_buff_head
1276 * @list_: list to peek at
1278 * Peek an &sk_buff. Unlike most other operations you _MUST_
1279 * be careful with this one. A peek leaves the buffer on the
1280 * list and someone else may run off with it. You must hold
1281 * the appropriate locks or have a private queue to do this.
1283 * Returns %NULL for an empty list or a pointer to the tail element.
1284 * The reference count is not incremented and the reference is therefore
1285 * volatile. Use with caution.
1287 static inline struct sk_buff
*skb_peek_tail(const struct sk_buff_head
*list_
)
1289 struct sk_buff
*skb
= list_
->prev
;
1291 if (skb
== (struct sk_buff
*)list_
)
1298 * skb_queue_len - get queue length
1299 * @list_: list to measure
1301 * Return the length of an &sk_buff queue.
1303 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
1309 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1310 * @list: queue to initialize
1312 * This initializes only the list and queue length aspects of
1313 * an sk_buff_head object. This allows to initialize the list
1314 * aspects of an sk_buff_head without reinitializing things like
1315 * the spinlock. It can also be used for on-stack sk_buff_head
1316 * objects where the spinlock is known to not be used.
1318 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
1320 list
->prev
= list
->next
= (struct sk_buff
*)list
;
1325 * This function creates a split out lock class for each invocation;
1326 * this is needed for now since a whole lot of users of the skb-queue
1327 * infrastructure in drivers have different locking usage (in hardirq)
1328 * than the networking core (in softirq only). In the long run either the
1329 * network layer or drivers should need annotation to consolidate the
1330 * main types of usage into 3 classes.
1332 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
1334 spin_lock_init(&list
->lock
);
1335 __skb_queue_head_init(list
);
1338 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
1339 struct lock_class_key
*class)
1341 skb_queue_head_init(list
);
1342 lockdep_set_class(&list
->lock
, class);
1346 * Insert an sk_buff on a list.
1348 * The "__skb_xxxx()" functions are the non-atomic ones that
1349 * can only be called with interrupts disabled.
1351 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
,
1352 struct sk_buff_head
*list
);
1353 static inline void __skb_insert(struct sk_buff
*newsk
,
1354 struct sk_buff
*prev
, struct sk_buff
*next
,
1355 struct sk_buff_head
*list
)
1359 next
->prev
= prev
->next
= newsk
;
1363 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
1364 struct sk_buff
*prev
,
1365 struct sk_buff
*next
)
1367 struct sk_buff
*first
= list
->next
;
1368 struct sk_buff
*last
= list
->prev
;
1378 * skb_queue_splice - join two skb lists, this is designed for stacks
1379 * @list: the new list to add
1380 * @head: the place to add it in the first list
1382 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
1383 struct sk_buff_head
*head
)
1385 if (!skb_queue_empty(list
)) {
1386 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1387 head
->qlen
+= list
->qlen
;
1392 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1393 * @list: the new list to add
1394 * @head: the place to add it in the first list
1396 * The list at @list is reinitialised
1398 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
1399 struct sk_buff_head
*head
)
1401 if (!skb_queue_empty(list
)) {
1402 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
1403 head
->qlen
+= list
->qlen
;
1404 __skb_queue_head_init(list
);
1409 * skb_queue_splice_tail - join two skb lists, each list being a queue
1410 * @list: the new list to add
1411 * @head: the place to add it in the first list
1413 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
1414 struct sk_buff_head
*head
)
1416 if (!skb_queue_empty(list
)) {
1417 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1418 head
->qlen
+= list
->qlen
;
1423 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1424 * @list: the new list to add
1425 * @head: the place to add it in the first list
1427 * Each of the lists is a queue.
1428 * The list at @list is reinitialised
1430 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
1431 struct sk_buff_head
*head
)
1433 if (!skb_queue_empty(list
)) {
1434 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
1435 head
->qlen
+= list
->qlen
;
1436 __skb_queue_head_init(list
);
1441 * __skb_queue_after - queue a buffer at the list head
1442 * @list: list to use
1443 * @prev: place after this buffer
1444 * @newsk: buffer to queue
1446 * Queue a buffer int the middle of a list. This function takes no locks
1447 * and you must therefore hold required locks before calling it.
1449 * A buffer cannot be placed on two lists at the same time.
1451 static inline void __skb_queue_after(struct sk_buff_head
*list
,
1452 struct sk_buff
*prev
,
1453 struct sk_buff
*newsk
)
1455 __skb_insert(newsk
, prev
, prev
->next
, list
);
1458 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
1459 struct sk_buff_head
*list
);
1461 static inline void __skb_queue_before(struct sk_buff_head
*list
,
1462 struct sk_buff
*next
,
1463 struct sk_buff
*newsk
)
1465 __skb_insert(newsk
, next
->prev
, next
, list
);
1469 * __skb_queue_head - queue a buffer at the list head
1470 * @list: list to use
1471 * @newsk: buffer to queue
1473 * Queue a buffer at the start of a list. This function takes no locks
1474 * and you must therefore hold required locks before calling it.
1476 * A buffer cannot be placed on two lists at the same time.
1478 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1479 static inline void __skb_queue_head(struct sk_buff_head
*list
,
1480 struct sk_buff
*newsk
)
1482 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
1486 * __skb_queue_tail - queue a buffer at the list tail
1487 * @list: list to use
1488 * @newsk: buffer to queue
1490 * Queue a buffer at the end of a list. This function takes no locks
1491 * and you must therefore hold required locks before calling it.
1493 * A buffer cannot be placed on two lists at the same time.
1495 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
1496 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
1497 struct sk_buff
*newsk
)
1499 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
1503 * remove sk_buff from list. _Must_ be called atomically, and with
1506 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
1507 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1509 struct sk_buff
*next
, *prev
;
1514 skb
->next
= skb
->prev
= NULL
;
1520 * __skb_dequeue - remove from the head of the queue
1521 * @list: list to dequeue from
1523 * Remove the head of the list. This function does not take any locks
1524 * so must be used with appropriate locks held only. The head item is
1525 * returned or %NULL if the list is empty.
1527 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
1528 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
1530 struct sk_buff
*skb
= skb_peek(list
);
1532 __skb_unlink(skb
, list
);
1537 * __skb_dequeue_tail - remove from the tail of the queue
1538 * @list: list to dequeue from
1540 * Remove the tail of the list. This function does not take any locks
1541 * so must be used with appropriate locks held only. The tail item is
1542 * returned or %NULL if the list is empty.
1544 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
1545 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
1547 struct sk_buff
*skb
= skb_peek_tail(list
);
1549 __skb_unlink(skb
, list
);
1554 static inline bool skb_is_nonlinear(const struct sk_buff
*skb
)
1556 return skb
->data_len
;
1559 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
1561 return skb
->len
- skb
->data_len
;
1564 static inline int skb_pagelen(const struct sk_buff
*skb
)
1568 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
1569 len
+= skb_frag_size(&skb_shinfo(skb
)->frags
[i
]);
1570 return len
+ skb_headlen(skb
);
1574 * __skb_fill_page_desc - initialise a paged fragment in an skb
1575 * @skb: buffer containing fragment to be initialised
1576 * @i: paged fragment index to initialise
1577 * @page: the page to use for this fragment
1578 * @off: the offset to the data with @page
1579 * @size: the length of the data
1581 * Initialises the @i'th fragment of @skb to point to &size bytes at
1582 * offset @off within @page.
1584 * Does not take any additional reference on the fragment.
1586 static inline void __skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1587 struct page
*page
, int off
, int size
)
1589 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1592 * Propagate page->pfmemalloc to the skb if we can. The problem is
1593 * that not all callers have unique ownership of the page. If
1594 * pfmemalloc is set, we check the mapping as a mapping implies
1595 * page->index is set (index and pfmemalloc share space).
1596 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1597 * do not lose pfmemalloc information as the pages would not be
1598 * allocated using __GFP_MEMALLOC.
1600 frag
->page
.p
= page
;
1601 frag
->page_offset
= off
;
1602 skb_frag_size_set(frag
, size
);
1604 page
= compound_head(page
);
1605 if (page
->pfmemalloc
&& !page
->mapping
)
1606 skb
->pfmemalloc
= true;
1610 * skb_fill_page_desc - initialise a paged fragment in an skb
1611 * @skb: buffer containing fragment to be initialised
1612 * @i: paged fragment index to initialise
1613 * @page: the page to use for this fragment
1614 * @off: the offset to the data with @page
1615 * @size: the length of the data
1617 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1618 * @skb to point to @size bytes at offset @off within @page. In
1619 * addition updates @skb such that @i is the last fragment.
1621 * Does not take any additional reference on the fragment.
1623 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
1624 struct page
*page
, int off
, int size
)
1626 __skb_fill_page_desc(skb
, i
, page
, off
, size
);
1627 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1630 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
1631 int size
, unsigned int truesize
);
1633 void skb_coalesce_rx_frag(struct sk_buff
*skb
, int i
, int size
,
1634 unsigned int truesize
);
1636 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1637 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1638 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1640 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1641 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1643 return skb
->head
+ skb
->tail
;
1646 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1648 skb
->tail
= skb
->data
- skb
->head
;
1651 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1653 skb_reset_tail_pointer(skb
);
1654 skb
->tail
+= offset
;
1657 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1658 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1663 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1665 skb
->tail
= skb
->data
;
1668 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1670 skb
->tail
= skb
->data
+ offset
;
1673 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1676 * Add data to an sk_buff
1678 unsigned char *pskb_put(struct sk_buff
*skb
, struct sk_buff
*tail
, int len
);
1679 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1680 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1682 unsigned char *tmp
= skb_tail_pointer(skb
);
1683 SKB_LINEAR_ASSERT(skb
);
1689 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1690 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1697 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1698 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1701 BUG_ON(skb
->len
< skb
->data_len
);
1702 return skb
->data
+= len
;
1705 static inline unsigned char *skb_pull_inline(struct sk_buff
*skb
, unsigned int len
)
1707 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1710 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1712 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1714 if (len
> skb_headlen(skb
) &&
1715 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1718 return skb
->data
+= len
;
1721 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1723 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1726 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1728 if (likely(len
<= skb_headlen(skb
)))
1730 if (unlikely(len
> skb
->len
))
1732 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1736 * skb_headroom - bytes at buffer head
1737 * @skb: buffer to check
1739 * Return the number of bytes of free space at the head of an &sk_buff.
1741 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1743 return skb
->data
- skb
->head
;
1747 * skb_tailroom - bytes at buffer end
1748 * @skb: buffer to check
1750 * Return the number of bytes of free space at the tail of an sk_buff
1752 static inline int skb_tailroom(const struct sk_buff
*skb
)
1754 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1758 * skb_availroom - bytes at buffer end
1759 * @skb: buffer to check
1761 * Return the number of bytes of free space at the tail of an sk_buff
1762 * allocated by sk_stream_alloc()
1764 static inline int skb_availroom(const struct sk_buff
*skb
)
1766 if (skb_is_nonlinear(skb
))
1769 return skb
->end
- skb
->tail
- skb
->reserved_tailroom
;
1773 * skb_reserve - adjust headroom
1774 * @skb: buffer to alter
1775 * @len: bytes to move
1777 * Increase the headroom of an empty &sk_buff by reducing the tail
1778 * room. This is only allowed for an empty buffer.
1780 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1786 #define ENCAP_TYPE_ETHER 0
1787 #define ENCAP_TYPE_IPPROTO 1
1789 static inline void skb_set_inner_protocol(struct sk_buff
*skb
,
1792 skb
->inner_protocol
= protocol
;
1793 skb
->inner_protocol_type
= ENCAP_TYPE_ETHER
;
1796 static inline void skb_set_inner_ipproto(struct sk_buff
*skb
,
1799 skb
->inner_ipproto
= ipproto
;
1800 skb
->inner_protocol_type
= ENCAP_TYPE_IPPROTO
;
1803 static inline void skb_reset_inner_headers(struct sk_buff
*skb
)
1805 skb
->inner_mac_header
= skb
->mac_header
;
1806 skb
->inner_network_header
= skb
->network_header
;
1807 skb
->inner_transport_header
= skb
->transport_header
;
1810 static inline void skb_reset_mac_len(struct sk_buff
*skb
)
1812 skb
->mac_len
= skb
->network_header
- skb
->mac_header
;
1815 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1818 return skb
->head
+ skb
->inner_transport_header
;
1821 static inline void skb_reset_inner_transport_header(struct sk_buff
*skb
)
1823 skb
->inner_transport_header
= skb
->data
- skb
->head
;
1826 static inline void skb_set_inner_transport_header(struct sk_buff
*skb
,
1829 skb_reset_inner_transport_header(skb
);
1830 skb
->inner_transport_header
+= offset
;
1833 static inline unsigned char *skb_inner_network_header(const struct sk_buff
*skb
)
1835 return skb
->head
+ skb
->inner_network_header
;
1838 static inline void skb_reset_inner_network_header(struct sk_buff
*skb
)
1840 skb
->inner_network_header
= skb
->data
- skb
->head
;
1843 static inline void skb_set_inner_network_header(struct sk_buff
*skb
,
1846 skb_reset_inner_network_header(skb
);
1847 skb
->inner_network_header
+= offset
;
1850 static inline unsigned char *skb_inner_mac_header(const struct sk_buff
*skb
)
1852 return skb
->head
+ skb
->inner_mac_header
;
1855 static inline void skb_reset_inner_mac_header(struct sk_buff
*skb
)
1857 skb
->inner_mac_header
= skb
->data
- skb
->head
;
1860 static inline void skb_set_inner_mac_header(struct sk_buff
*skb
,
1863 skb_reset_inner_mac_header(skb
);
1864 skb
->inner_mac_header
+= offset
;
1866 static inline bool skb_transport_header_was_set(const struct sk_buff
*skb
)
1868 return skb
->transport_header
!= (typeof(skb
->transport_header
))~0U;
1871 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1873 return skb
->head
+ skb
->transport_header
;
1876 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1878 skb
->transport_header
= skb
->data
- skb
->head
;
1881 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1884 skb_reset_transport_header(skb
);
1885 skb
->transport_header
+= offset
;
1888 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1890 return skb
->head
+ skb
->network_header
;
1893 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1895 skb
->network_header
= skb
->data
- skb
->head
;
1898 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1900 skb_reset_network_header(skb
);
1901 skb
->network_header
+= offset
;
1904 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1906 return skb
->head
+ skb
->mac_header
;
1909 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1911 return skb
->mac_header
!= (typeof(skb
->mac_header
))~0U;
1914 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1916 skb
->mac_header
= skb
->data
- skb
->head
;
1919 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1921 skb_reset_mac_header(skb
);
1922 skb
->mac_header
+= offset
;
1925 static inline void skb_pop_mac_header(struct sk_buff
*skb
)
1927 skb
->mac_header
= skb
->network_header
;
1930 static inline void skb_probe_transport_header(struct sk_buff
*skb
,
1931 const int offset_hint
)
1933 struct flow_keys keys
;
1935 if (skb_transport_header_was_set(skb
))
1937 else if (skb_flow_dissect(skb
, &keys
))
1938 skb_set_transport_header(skb
, keys
.thoff
);
1940 skb_set_transport_header(skb
, offset_hint
);
1943 static inline void skb_mac_header_rebuild(struct sk_buff
*skb
)
1945 if (skb_mac_header_was_set(skb
)) {
1946 const unsigned char *old_mac
= skb_mac_header(skb
);
1948 skb_set_mac_header(skb
, -skb
->mac_len
);
1949 memmove(skb_mac_header(skb
), old_mac
, skb
->mac_len
);
1953 static inline int skb_checksum_start_offset(const struct sk_buff
*skb
)
1955 return skb
->csum_start
- skb_headroom(skb
);
1958 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1960 return skb_transport_header(skb
) - skb
->data
;
1963 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1965 return skb
->transport_header
- skb
->network_header
;
1968 static inline u32
skb_inner_network_header_len(const struct sk_buff
*skb
)
1970 return skb
->inner_transport_header
- skb
->inner_network_header
;
1973 static inline int skb_network_offset(const struct sk_buff
*skb
)
1975 return skb_network_header(skb
) - skb
->data
;
1978 static inline int skb_inner_network_offset(const struct sk_buff
*skb
)
1980 return skb_inner_network_header(skb
) - skb
->data
;
1983 static inline int pskb_network_may_pull(struct sk_buff
*skb
, unsigned int len
)
1985 return pskb_may_pull(skb
, skb_network_offset(skb
) + len
);
1989 * CPUs often take a performance hit when accessing unaligned memory
1990 * locations. The actual performance hit varies, it can be small if the
1991 * hardware handles it or large if we have to take an exception and fix it
1994 * Since an ethernet header is 14 bytes network drivers often end up with
1995 * the IP header at an unaligned offset. The IP header can be aligned by
1996 * shifting the start of the packet by 2 bytes. Drivers should do this
1999 * skb_reserve(skb, NET_IP_ALIGN);
2001 * The downside to this alignment of the IP header is that the DMA is now
2002 * unaligned. On some architectures the cost of an unaligned DMA is high
2003 * and this cost outweighs the gains made by aligning the IP header.
2005 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2008 #ifndef NET_IP_ALIGN
2009 #define NET_IP_ALIGN 2
2013 * The networking layer reserves some headroom in skb data (via
2014 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2015 * the header has to grow. In the default case, if the header has to grow
2016 * 32 bytes or less we avoid the reallocation.
2018 * Unfortunately this headroom changes the DMA alignment of the resulting
2019 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2020 * on some architectures. An architecture can override this value,
2021 * perhaps setting it to a cacheline in size (since that will maintain
2022 * cacheline alignment of the DMA). It must be a power of 2.
2024 * Various parts of the networking layer expect at least 32 bytes of
2025 * headroom, you should not reduce this.
2027 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2028 * to reduce average number of cache lines per packet.
2029 * get_rps_cpus() for example only access one 64 bytes aligned block :
2030 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2033 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2036 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
2038 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
2040 if (unlikely(skb_is_nonlinear(skb
))) {
2045 skb_set_tail_pointer(skb
, len
);
2048 void skb_trim(struct sk_buff
*skb
, unsigned int len
);
2050 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2053 return ___pskb_trim(skb
, len
);
2054 __skb_trim(skb
, len
);
2058 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
2060 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
2064 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2065 * @skb: buffer to alter
2068 * This is identical to pskb_trim except that the caller knows that
2069 * the skb is not cloned so we should never get an error due to out-
2072 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
2074 int err
= pskb_trim(skb
, len
);
2079 * skb_orphan - orphan a buffer
2080 * @skb: buffer to orphan
2082 * If a buffer currently has an owner then we call the owner's
2083 * destructor function and make the @skb unowned. The buffer continues
2084 * to exist but is no longer charged to its former owner.
2086 static inline void skb_orphan(struct sk_buff
*skb
)
2088 if (skb
->destructor
) {
2089 skb
->destructor(skb
);
2090 skb
->destructor
= NULL
;
2098 * skb_orphan_frags - orphan the frags contained in a buffer
2099 * @skb: buffer to orphan frags from
2100 * @gfp_mask: allocation mask for replacement pages
2102 * For each frag in the SKB which needs a destructor (i.e. has an
2103 * owner) create a copy of that frag and release the original
2104 * page by calling the destructor.
2106 static inline int skb_orphan_frags(struct sk_buff
*skb
, gfp_t gfp_mask
)
2108 if (likely(!(skb_shinfo(skb
)->tx_flags
& SKBTX_DEV_ZEROCOPY
)))
2110 return skb_copy_ubufs(skb
, gfp_mask
);
2114 * __skb_queue_purge - empty a list
2115 * @list: list to empty
2117 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2118 * the list and one reference dropped. This function does not take the
2119 * list lock and the caller must hold the relevant locks to use it.
2121 void skb_queue_purge(struct sk_buff_head
*list
);
2122 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
2124 struct sk_buff
*skb
;
2125 while ((skb
= __skb_dequeue(list
)) != NULL
)
2129 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2130 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2131 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2133 void *netdev_alloc_frag(unsigned int fragsz
);
2135 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
, unsigned int length
,
2139 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2140 * @dev: network device to receive on
2141 * @length: length to allocate
2143 * Allocate a new &sk_buff and assign it a usage count of one. The
2144 * buffer has unspecified headroom built in. Users should allocate
2145 * the headroom they think they need without accounting for the
2146 * built in space. The built in space is used for optimisations.
2148 * %NULL is returned if there is no free memory. Although this function
2149 * allocates memory it can be called from an interrupt.
2151 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
2152 unsigned int length
)
2154 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
2157 /* legacy helper around __netdev_alloc_skb() */
2158 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
2161 return __netdev_alloc_skb(NULL
, length
, gfp_mask
);
2164 /* legacy helper around netdev_alloc_skb() */
2165 static inline struct sk_buff
*dev_alloc_skb(unsigned int length
)
2167 return netdev_alloc_skb(NULL
, length
);
2171 static inline struct sk_buff
*__netdev_alloc_skb_ip_align(struct net_device
*dev
,
2172 unsigned int length
, gfp_t gfp
)
2174 struct sk_buff
*skb
= __netdev_alloc_skb(dev
, length
+ NET_IP_ALIGN
, gfp
);
2176 if (NET_IP_ALIGN
&& skb
)
2177 skb_reserve(skb
, NET_IP_ALIGN
);
2181 static inline struct sk_buff
*netdev_alloc_skb_ip_align(struct net_device
*dev
,
2182 unsigned int length
)
2184 return __netdev_alloc_skb_ip_align(dev
, length
, GFP_ATOMIC
);
2187 void *napi_alloc_frag(unsigned int fragsz
);
2188 struct sk_buff
*__napi_alloc_skb(struct napi_struct
*napi
,
2189 unsigned int length
, gfp_t gfp_mask
);
2190 static inline struct sk_buff
*napi_alloc_skb(struct napi_struct
*napi
,
2191 unsigned int length
)
2193 return __napi_alloc_skb(napi
, length
, GFP_ATOMIC
);
2197 * __dev_alloc_pages - allocate page for network Rx
2198 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2199 * @order: size of the allocation
2201 * Allocate a new page.
2203 * %NULL is returned if there is no free memory.
2205 static inline struct page
*__dev_alloc_pages(gfp_t gfp_mask
,
2208 /* This piece of code contains several assumptions.
2209 * 1. This is for device Rx, therefor a cold page is preferred.
2210 * 2. The expectation is the user wants a compound page.
2211 * 3. If requesting a order 0 page it will not be compound
2212 * due to the check to see if order has a value in prep_new_page
2213 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2214 * code in gfp_to_alloc_flags that should be enforcing this.
2216 gfp_mask
|= __GFP_COLD
| __GFP_COMP
| __GFP_MEMALLOC
;
2218 return alloc_pages_node(NUMA_NO_NODE
, gfp_mask
, order
);
2221 static inline struct page
*dev_alloc_pages(unsigned int order
)
2223 return __dev_alloc_pages(GFP_ATOMIC
, order
);
2227 * __dev_alloc_page - allocate a page for network Rx
2228 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2230 * Allocate a new page.
2232 * %NULL is returned if there is no free memory.
2234 static inline struct page
*__dev_alloc_page(gfp_t gfp_mask
)
2236 return __dev_alloc_pages(gfp_mask
, 0);
2239 static inline struct page
*dev_alloc_page(void)
2241 return __dev_alloc_page(GFP_ATOMIC
);
2245 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2246 * @page: The page that was allocated from skb_alloc_page
2247 * @skb: The skb that may need pfmemalloc set
2249 static inline void skb_propagate_pfmemalloc(struct page
*page
,
2250 struct sk_buff
*skb
)
2252 if (page
&& page
->pfmemalloc
)
2253 skb
->pfmemalloc
= true;
2257 * skb_frag_page - retrieve the page referred to by a paged fragment
2258 * @frag: the paged fragment
2260 * Returns the &struct page associated with @frag.
2262 static inline struct page
*skb_frag_page(const skb_frag_t
*frag
)
2264 return frag
->page
.p
;
2268 * __skb_frag_ref - take an addition reference on a paged fragment.
2269 * @frag: the paged fragment
2271 * Takes an additional reference on the paged fragment @frag.
2273 static inline void __skb_frag_ref(skb_frag_t
*frag
)
2275 get_page(skb_frag_page(frag
));
2279 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2281 * @f: the fragment offset.
2283 * Takes an additional reference on the @f'th paged fragment of @skb.
2285 static inline void skb_frag_ref(struct sk_buff
*skb
, int f
)
2287 __skb_frag_ref(&skb_shinfo(skb
)->frags
[f
]);
2291 * __skb_frag_unref - release a reference on a paged fragment.
2292 * @frag: the paged fragment
2294 * Releases a reference on the paged fragment @frag.
2296 static inline void __skb_frag_unref(skb_frag_t
*frag
)
2298 put_page(skb_frag_page(frag
));
2302 * skb_frag_unref - release a reference on a paged fragment of an skb.
2304 * @f: the fragment offset
2306 * Releases a reference on the @f'th paged fragment of @skb.
2308 static inline void skb_frag_unref(struct sk_buff
*skb
, int f
)
2310 __skb_frag_unref(&skb_shinfo(skb
)->frags
[f
]);
2314 * skb_frag_address - gets the address of the data contained in a paged fragment
2315 * @frag: the paged fragment buffer
2317 * Returns the address of the data within @frag. The page must already
2320 static inline void *skb_frag_address(const skb_frag_t
*frag
)
2322 return page_address(skb_frag_page(frag
)) + frag
->page_offset
;
2326 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2327 * @frag: the paged fragment buffer
2329 * Returns the address of the data within @frag. Checks that the page
2330 * is mapped and returns %NULL otherwise.
2332 static inline void *skb_frag_address_safe(const skb_frag_t
*frag
)
2334 void *ptr
= page_address(skb_frag_page(frag
));
2338 return ptr
+ frag
->page_offset
;
2342 * __skb_frag_set_page - sets the page contained in a paged fragment
2343 * @frag: the paged fragment
2344 * @page: the page to set
2346 * Sets the fragment @frag to contain @page.
2348 static inline void __skb_frag_set_page(skb_frag_t
*frag
, struct page
*page
)
2350 frag
->page
.p
= page
;
2354 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2356 * @f: the fragment offset
2357 * @page: the page to set
2359 * Sets the @f'th fragment of @skb to contain @page.
2361 static inline void skb_frag_set_page(struct sk_buff
*skb
, int f
,
2364 __skb_frag_set_page(&skb_shinfo(skb
)->frags
[f
], page
);
2367 bool skb_page_frag_refill(unsigned int sz
, struct page_frag
*pfrag
, gfp_t prio
);
2370 * skb_frag_dma_map - maps a paged fragment via the DMA API
2371 * @dev: the device to map the fragment to
2372 * @frag: the paged fragment to map
2373 * @offset: the offset within the fragment (starting at the
2374 * fragment's own offset)
2375 * @size: the number of bytes to map
2376 * @dir: the direction of the mapping (%PCI_DMA_*)
2378 * Maps the page associated with @frag to @device.
2380 static inline dma_addr_t
skb_frag_dma_map(struct device
*dev
,
2381 const skb_frag_t
*frag
,
2382 size_t offset
, size_t size
,
2383 enum dma_data_direction dir
)
2385 return dma_map_page(dev
, skb_frag_page(frag
),
2386 frag
->page_offset
+ offset
, size
, dir
);
2389 static inline struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
2392 return __pskb_copy(skb
, skb_headroom(skb
), gfp_mask
);
2396 static inline struct sk_buff
*pskb_copy_for_clone(struct sk_buff
*skb
,
2399 return __pskb_copy_fclone(skb
, skb_headroom(skb
), gfp_mask
, true);
2404 * skb_clone_writable - is the header of a clone writable
2405 * @skb: buffer to check
2406 * @len: length up to which to write
2408 * Returns true if modifying the header part of the cloned buffer
2409 * does not requires the data to be copied.
2411 static inline int skb_clone_writable(const struct sk_buff
*skb
, unsigned int len
)
2413 return !skb_header_cloned(skb
) &&
2414 skb_headroom(skb
) + len
<= skb
->hdr_len
;
2417 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
2422 if (headroom
> skb_headroom(skb
))
2423 delta
= headroom
- skb_headroom(skb
);
2425 if (delta
|| cloned
)
2426 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
2432 * skb_cow - copy header of skb when it is required
2433 * @skb: buffer to cow
2434 * @headroom: needed headroom
2436 * If the skb passed lacks sufficient headroom or its data part
2437 * is shared, data is reallocated. If reallocation fails, an error
2438 * is returned and original skb is not changed.
2440 * The result is skb with writable area skb->head...skb->tail
2441 * and at least @headroom of space at head.
2443 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
2445 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
2449 * skb_cow_head - skb_cow but only making the head writable
2450 * @skb: buffer to cow
2451 * @headroom: needed headroom
2453 * This function is identical to skb_cow except that we replace the
2454 * skb_cloned check by skb_header_cloned. It should be used when
2455 * you only need to push on some header and do not need to modify
2458 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
2460 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
2464 * skb_padto - pad an skbuff up to a minimal size
2465 * @skb: buffer to pad
2466 * @len: minimal length
2468 * Pads up a buffer to ensure the trailing bytes exist and are
2469 * blanked. If the buffer already contains sufficient data it
2470 * is untouched. Otherwise it is extended. Returns zero on
2471 * success. The skb is freed on error.
2473 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
2475 unsigned int size
= skb
->len
;
2476 if (likely(size
>= len
))
2478 return skb_pad(skb
, len
- size
);
2482 * skb_put_padto - increase size and pad an skbuff up to a minimal size
2483 * @skb: buffer to pad
2484 * @len: minimal length
2486 * Pads up a buffer to ensure the trailing bytes exist and are
2487 * blanked. If the buffer already contains sufficient data it
2488 * is untouched. Otherwise it is extended. Returns zero on
2489 * success. The skb is freed on error.
2491 static inline int skb_put_padto(struct sk_buff
*skb
, unsigned int len
)
2493 unsigned int size
= skb
->len
;
2495 if (unlikely(size
< len
)) {
2497 if (skb_pad(skb
, len
))
2499 __skb_put(skb
, len
);
2504 static inline int skb_add_data(struct sk_buff
*skb
,
2505 struct iov_iter
*from
, int copy
)
2507 const int off
= skb
->len
;
2509 if (skb
->ip_summed
== CHECKSUM_NONE
) {
2511 if (csum_and_copy_from_iter(skb_put(skb
, copy
), copy
,
2512 &csum
, from
) == copy
) {
2513 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
2516 } else if (copy_from_iter(skb_put(skb
, copy
), copy
, from
) == copy
)
2519 __skb_trim(skb
, off
);
2523 static inline bool skb_can_coalesce(struct sk_buff
*skb
, int i
,
2524 const struct page
*page
, int off
)
2527 const struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
2529 return page
== skb_frag_page(frag
) &&
2530 off
== frag
->page_offset
+ skb_frag_size(frag
);
2535 static inline int __skb_linearize(struct sk_buff
*skb
)
2537 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
2541 * skb_linearize - convert paged skb to linear one
2542 * @skb: buffer to linarize
2544 * If there is no free memory -ENOMEM is returned, otherwise zero
2545 * is returned and the old skb data released.
2547 static inline int skb_linearize(struct sk_buff
*skb
)
2549 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
2553 * skb_has_shared_frag - can any frag be overwritten
2554 * @skb: buffer to test
2556 * Return true if the skb has at least one frag that might be modified
2557 * by an external entity (as in vmsplice()/sendfile())
2559 static inline bool skb_has_shared_frag(const struct sk_buff
*skb
)
2561 return skb_is_nonlinear(skb
) &&
2562 skb_shinfo(skb
)->tx_flags
& SKBTX_SHARED_FRAG
;
2566 * skb_linearize_cow - make sure skb is linear and writable
2567 * @skb: buffer to process
2569 * If there is no free memory -ENOMEM is returned, otherwise zero
2570 * is returned and the old skb data released.
2572 static inline int skb_linearize_cow(struct sk_buff
*skb
)
2574 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
2575 __skb_linearize(skb
) : 0;
2579 * skb_postpull_rcsum - update checksum for received skb after pull
2580 * @skb: buffer to update
2581 * @start: start of data before pull
2582 * @len: length of data pulled
2584 * After doing a pull on a received packet, you need to call this to
2585 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2586 * CHECKSUM_NONE so that it can be recomputed from scratch.
2589 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
2590 const void *start
, unsigned int len
)
2592 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2593 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
2596 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
2599 * pskb_trim_rcsum - trim received skb and update checksum
2600 * @skb: buffer to trim
2603 * This is exactly the same as pskb_trim except that it ensures the
2604 * checksum of received packets are still valid after the operation.
2607 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
2609 if (likely(len
>= skb
->len
))
2611 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
2612 skb
->ip_summed
= CHECKSUM_NONE
;
2613 return __pskb_trim(skb
, len
);
2616 #define skb_queue_walk(queue, skb) \
2617 for (skb = (queue)->next; \
2618 skb != (struct sk_buff *)(queue); \
2621 #define skb_queue_walk_safe(queue, skb, tmp) \
2622 for (skb = (queue)->next, tmp = skb->next; \
2623 skb != (struct sk_buff *)(queue); \
2624 skb = tmp, tmp = skb->next)
2626 #define skb_queue_walk_from(queue, skb) \
2627 for (; skb != (struct sk_buff *)(queue); \
2630 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2631 for (tmp = skb->next; \
2632 skb != (struct sk_buff *)(queue); \
2633 skb = tmp, tmp = skb->next)
2635 #define skb_queue_reverse_walk(queue, skb) \
2636 for (skb = (queue)->prev; \
2637 skb != (struct sk_buff *)(queue); \
2640 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2641 for (skb = (queue)->prev, tmp = skb->prev; \
2642 skb != (struct sk_buff *)(queue); \
2643 skb = tmp, tmp = skb->prev)
2645 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2646 for (tmp = skb->prev; \
2647 skb != (struct sk_buff *)(queue); \
2648 skb = tmp, tmp = skb->prev)
2650 static inline bool skb_has_frag_list(const struct sk_buff
*skb
)
2652 return skb_shinfo(skb
)->frag_list
!= NULL
;
2655 static inline void skb_frag_list_init(struct sk_buff
*skb
)
2657 skb_shinfo(skb
)->frag_list
= NULL
;
2660 static inline void skb_frag_add_head(struct sk_buff
*skb
, struct sk_buff
*frag
)
2662 frag
->next
= skb_shinfo(skb
)->frag_list
;
2663 skb_shinfo(skb
)->frag_list
= frag
;
2666 #define skb_walk_frags(skb, iter) \
2667 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2669 struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
2670 int *peeked
, int *off
, int *err
);
2671 struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
, int noblock
,
2673 unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
2674 struct poll_table_struct
*wait
);
2675 int skb_copy_datagram_iter(const struct sk_buff
*from
, int offset
,
2676 struct iov_iter
*to
, int size
);
2677 static inline int skb_copy_datagram_msg(const struct sk_buff
*from
, int offset
,
2678 struct msghdr
*msg
, int size
)
2680 return skb_copy_datagram_iter(from
, offset
, &msg
->msg_iter
, size
);
2682 int skb_copy_and_csum_datagram_msg(struct sk_buff
*skb
, int hlen
,
2683 struct msghdr
*msg
);
2684 int skb_copy_datagram_from_iter(struct sk_buff
*skb
, int offset
,
2685 struct iov_iter
*from
, int len
);
2686 int zerocopy_sg_from_iter(struct sk_buff
*skb
, struct iov_iter
*frm
);
2687 void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
2688 void skb_free_datagram_locked(struct sock
*sk
, struct sk_buff
*skb
);
2689 int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
, unsigned int flags
);
2690 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
);
2691 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
);
2692 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
, u8
*to
,
2693 int len
, __wsum csum
);
2694 int skb_splice_bits(struct sk_buff
*skb
, unsigned int offset
,
2695 struct pipe_inode_info
*pipe
, unsigned int len
,
2696 unsigned int flags
);
2697 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
2698 unsigned int skb_zerocopy_headlen(const struct sk_buff
*from
);
2699 int skb_zerocopy(struct sk_buff
*to
, struct sk_buff
*from
,
2701 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
);
2702 int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
, int shiftlen
);
2703 void skb_scrub_packet(struct sk_buff
*skb
, bool xnet
);
2704 unsigned int skb_gso_transport_seglen(const struct sk_buff
*skb
);
2705 struct sk_buff
*skb_segment(struct sk_buff
*skb
, netdev_features_t features
);
2706 struct sk_buff
*skb_vlan_untag(struct sk_buff
*skb
);
2707 int skb_ensure_writable(struct sk_buff
*skb
, int write_len
);
2708 int skb_vlan_pop(struct sk_buff
*skb
);
2709 int skb_vlan_push(struct sk_buff
*skb
, __be16 vlan_proto
, u16 vlan_tci
);
2711 static inline int memcpy_from_msg(void *data
, struct msghdr
*msg
, int len
)
2713 return copy_from_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
2716 static inline int memcpy_to_msg(struct msghdr
*msg
, void *data
, int len
)
2718 return copy_to_iter(data
, len
, &msg
->msg_iter
) == len
? 0 : -EFAULT
;
2721 struct skb_checksum_ops
{
2722 __wsum (*update
)(const void *mem
, int len
, __wsum wsum
);
2723 __wsum (*combine
)(__wsum csum
, __wsum csum2
, int offset
, int len
);
2726 __wsum
__skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2727 __wsum csum
, const struct skb_checksum_ops
*ops
);
2728 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
, int len
,
2731 static inline void *__skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2732 int len
, void *data
, int hlen
, void *buffer
)
2734 if (hlen
- offset
>= len
)
2735 return data
+ offset
;
2738 skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
2744 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
2745 int len
, void *buffer
)
2747 return __skb_header_pointer(skb
, offset
, len
, skb
->data
,
2748 skb_headlen(skb
), buffer
);
2752 * skb_needs_linearize - check if we need to linearize a given skb
2753 * depending on the given device features.
2754 * @skb: socket buffer to check
2755 * @features: net device features
2757 * Returns true if either:
2758 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2759 * 2. skb is fragmented and the device does not support SG.
2761 static inline bool skb_needs_linearize(struct sk_buff
*skb
,
2762 netdev_features_t features
)
2764 return skb_is_nonlinear(skb
) &&
2765 ((skb_has_frag_list(skb
) && !(features
& NETIF_F_FRAGLIST
)) ||
2766 (skb_shinfo(skb
)->nr_frags
&& !(features
& NETIF_F_SG
)));
2769 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
2771 const unsigned int len
)
2773 memcpy(to
, skb
->data
, len
);
2776 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
2777 const int offset
, void *to
,
2778 const unsigned int len
)
2780 memcpy(to
, skb
->data
+ offset
, len
);
2783 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
2785 const unsigned int len
)
2787 memcpy(skb
->data
, from
, len
);
2790 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
2793 const unsigned int len
)
2795 memcpy(skb
->data
+ offset
, from
, len
);
2798 void skb_init(void);
2800 static inline ktime_t
skb_get_ktime(const struct sk_buff
*skb
)
2806 * skb_get_timestamp - get timestamp from a skb
2807 * @skb: skb to get stamp from
2808 * @stamp: pointer to struct timeval to store stamp in
2810 * Timestamps are stored in the skb as offsets to a base timestamp.
2811 * This function converts the offset back to a struct timeval and stores
2814 static inline void skb_get_timestamp(const struct sk_buff
*skb
,
2815 struct timeval
*stamp
)
2817 *stamp
= ktime_to_timeval(skb
->tstamp
);
2820 static inline void skb_get_timestampns(const struct sk_buff
*skb
,
2821 struct timespec
*stamp
)
2823 *stamp
= ktime_to_timespec(skb
->tstamp
);
2826 static inline void __net_timestamp(struct sk_buff
*skb
)
2828 skb
->tstamp
= ktime_get_real();
2831 static inline ktime_t
net_timedelta(ktime_t t
)
2833 return ktime_sub(ktime_get_real(), t
);
2836 static inline ktime_t
net_invalid_timestamp(void)
2838 return ktime_set(0, 0);
2841 struct sk_buff
*skb_clone_sk(struct sk_buff
*skb
);
2843 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2845 void skb_clone_tx_timestamp(struct sk_buff
*skb
);
2846 bool skb_defer_rx_timestamp(struct sk_buff
*skb
);
2848 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2850 static inline void skb_clone_tx_timestamp(struct sk_buff
*skb
)
2854 static inline bool skb_defer_rx_timestamp(struct sk_buff
*skb
)
2859 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2862 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2864 * PHY drivers may accept clones of transmitted packets for
2865 * timestamping via their phy_driver.txtstamp method. These drivers
2866 * must call this function to return the skb back to the stack, with
2867 * or without a timestamp.
2869 * @skb: clone of the the original outgoing packet
2870 * @hwtstamps: hardware time stamps, may be NULL if not available
2873 void skb_complete_tx_timestamp(struct sk_buff
*skb
,
2874 struct skb_shared_hwtstamps
*hwtstamps
);
2876 void __skb_tstamp_tx(struct sk_buff
*orig_skb
,
2877 struct skb_shared_hwtstamps
*hwtstamps
,
2878 struct sock
*sk
, int tstype
);
2881 * skb_tstamp_tx - queue clone of skb with send time stamps
2882 * @orig_skb: the original outgoing packet
2883 * @hwtstamps: hardware time stamps, may be NULL if not available
2885 * If the skb has a socket associated, then this function clones the
2886 * skb (thus sharing the actual data and optional structures), stores
2887 * the optional hardware time stamping information (if non NULL) or
2888 * generates a software time stamp (otherwise), then queues the clone
2889 * to the error queue of the socket. Errors are silently ignored.
2891 void skb_tstamp_tx(struct sk_buff
*orig_skb
,
2892 struct skb_shared_hwtstamps
*hwtstamps
);
2894 static inline void sw_tx_timestamp(struct sk_buff
*skb
)
2896 if (skb_shinfo(skb
)->tx_flags
& SKBTX_SW_TSTAMP
&&
2897 !(skb_shinfo(skb
)->tx_flags
& SKBTX_IN_PROGRESS
))
2898 skb_tstamp_tx(skb
, NULL
);
2902 * skb_tx_timestamp() - Driver hook for transmit timestamping
2904 * Ethernet MAC Drivers should call this function in their hard_xmit()
2905 * function immediately before giving the sk_buff to the MAC hardware.
2907 * Specifically, one should make absolutely sure that this function is
2908 * called before TX completion of this packet can trigger. Otherwise
2909 * the packet could potentially already be freed.
2911 * @skb: A socket buffer.
2913 static inline void skb_tx_timestamp(struct sk_buff
*skb
)
2915 skb_clone_tx_timestamp(skb
);
2916 sw_tx_timestamp(skb
);
2920 * skb_complete_wifi_ack - deliver skb with wifi status
2922 * @skb: the original outgoing packet
2923 * @acked: ack status
2926 void skb_complete_wifi_ack(struct sk_buff
*skb
, bool acked
);
2928 __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
2929 __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
2931 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
2933 return ((skb
->ip_summed
== CHECKSUM_UNNECESSARY
) ||
2935 (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
2936 skb_checksum_start_offset(skb
) >= 0));
2940 * skb_checksum_complete - Calculate checksum of an entire packet
2941 * @skb: packet to process
2943 * This function calculates the checksum over the entire packet plus
2944 * the value of skb->csum. The latter can be used to supply the
2945 * checksum of a pseudo header as used by TCP/UDP. It returns the
2948 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2949 * this function can be used to verify that checksum on received
2950 * packets. In that case the function should return zero if the
2951 * checksum is correct. In particular, this function will return zero
2952 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2953 * hardware has already verified the correctness of the checksum.
2955 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
2957 return skb_csum_unnecessary(skb
) ?
2958 0 : __skb_checksum_complete(skb
);
2961 static inline void __skb_decr_checksum_unnecessary(struct sk_buff
*skb
)
2963 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
2964 if (skb
->csum_level
== 0)
2965 skb
->ip_summed
= CHECKSUM_NONE
;
2971 static inline void __skb_incr_checksum_unnecessary(struct sk_buff
*skb
)
2973 if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
2974 if (skb
->csum_level
< SKB_MAX_CSUM_LEVEL
)
2976 } else if (skb
->ip_summed
== CHECKSUM_NONE
) {
2977 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
2978 skb
->csum_level
= 0;
2982 static inline void __skb_mark_checksum_bad(struct sk_buff
*skb
)
2984 /* Mark current checksum as bad (typically called from GRO
2985 * path). In the case that ip_summed is CHECKSUM_NONE
2986 * this must be the first checksum encountered in the packet.
2987 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
2988 * checksum after the last one validated. For UDP, a zero
2989 * checksum can not be marked as bad.
2992 if (skb
->ip_summed
== CHECKSUM_NONE
||
2993 skb
->ip_summed
== CHECKSUM_UNNECESSARY
)
2997 /* Check if we need to perform checksum complete validation.
2999 * Returns true if checksum complete is needed, false otherwise
3000 * (either checksum is unnecessary or zero checksum is allowed).
3002 static inline bool __skb_checksum_validate_needed(struct sk_buff
*skb
,
3006 if (skb_csum_unnecessary(skb
) || (zero_okay
&& !check
)) {
3007 skb
->csum_valid
= 1;
3008 __skb_decr_checksum_unnecessary(skb
);
3015 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
3018 #define CHECKSUM_BREAK 76
3020 /* Unset checksum-complete
3022 * Unset checksum complete can be done when packet is being modified
3023 * (uncompressed for instance) and checksum-complete value is
3026 static inline void skb_checksum_complete_unset(struct sk_buff
*skb
)
3028 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3029 skb
->ip_summed
= CHECKSUM_NONE
;
3032 /* Validate (init) checksum based on checksum complete.
3035 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3036 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3037 * checksum is stored in skb->csum for use in __skb_checksum_complete
3038 * non-zero: value of invalid checksum
3041 static inline __sum16
__skb_checksum_validate_complete(struct sk_buff
*skb
,
3045 if (skb
->ip_summed
== CHECKSUM_COMPLETE
) {
3046 if (!csum_fold(csum_add(psum
, skb
->csum
))) {
3047 skb
->csum_valid
= 1;
3050 } else if (skb
->csum_bad
) {
3051 /* ip_summed == CHECKSUM_NONE in this case */
3057 if (complete
|| skb
->len
<= CHECKSUM_BREAK
) {
3060 csum
= __skb_checksum_complete(skb
);
3061 skb
->csum_valid
= !csum
;
3068 static inline __wsum
null_compute_pseudo(struct sk_buff
*skb
, int proto
)
3073 /* Perform checksum validate (init). Note that this is a macro since we only
3074 * want to calculate the pseudo header which is an input function if necessary.
3075 * First we try to validate without any computation (checksum unnecessary) and
3076 * then calculate based on checksum complete calling the function to compute
3080 * 0: checksum is validated or try to in skb_checksum_complete
3081 * non-zero: value of invalid checksum
3083 #define __skb_checksum_validate(skb, proto, complete, \
3084 zero_okay, check, compute_pseudo) \
3086 __sum16 __ret = 0; \
3087 skb->csum_valid = 0; \
3088 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
3089 __ret = __skb_checksum_validate_complete(skb, \
3090 complete, compute_pseudo(skb, proto)); \
3094 #define skb_checksum_init(skb, proto, compute_pseudo) \
3095 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
3097 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
3098 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
3100 #define skb_checksum_validate(skb, proto, compute_pseudo) \
3101 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
3103 #define skb_checksum_validate_zero_check(skb, proto, check, \
3105 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
3107 #define skb_checksum_simple_validate(skb) \
3108 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
3110 static inline bool __skb_checksum_convert_check(struct sk_buff
*skb
)
3112 return (skb
->ip_summed
== CHECKSUM_NONE
&&
3113 skb
->csum_valid
&& !skb
->csum_bad
);
3116 static inline void __skb_checksum_convert(struct sk_buff
*skb
,
3117 __sum16 check
, __wsum pseudo
)
3119 skb
->csum
= ~pseudo
;
3120 skb
->ip_summed
= CHECKSUM_COMPLETE
;
3123 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
3125 if (__skb_checksum_convert_check(skb)) \
3126 __skb_checksum_convert(skb, check, \
3127 compute_pseudo(skb, proto)); \
3130 static inline void skb_remcsum_adjust_partial(struct sk_buff
*skb
, void *ptr
,
3131 u16 start
, u16 offset
)
3133 skb
->ip_summed
= CHECKSUM_PARTIAL
;
3134 skb
->csum_start
= ((unsigned char *)ptr
+ start
) - skb
->head
;
3135 skb
->csum_offset
= offset
- start
;
3138 /* Update skbuf and packet to reflect the remote checksum offload operation.
3139 * When called, ptr indicates the starting point for skb->csum when
3140 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
3141 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
3143 static inline void skb_remcsum_process(struct sk_buff
*skb
, void *ptr
,
3144 int start
, int offset
, bool nopartial
)
3149 skb_remcsum_adjust_partial(skb
, ptr
, start
, offset
);
3153 if (unlikely(skb
->ip_summed
!= CHECKSUM_COMPLETE
)) {
3154 __skb_checksum_complete(skb
);
3155 skb_postpull_rcsum(skb
, skb
->data
, ptr
- (void *)skb
->data
);
3158 delta
= remcsum_adjust(ptr
, skb
->csum
, start
, offset
);
3160 /* Adjust skb->csum since we changed the packet */
3161 skb
->csum
= csum_add(skb
->csum
, delta
);
3164 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3165 void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
3166 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
3168 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
3169 nf_conntrack_destroy(nfct
);
3171 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
3174 atomic_inc(&nfct
->use
);
3177 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3178 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
3180 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
3183 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
3186 atomic_inc(&nf_bridge
->use
);
3188 #endif /* CONFIG_BRIDGE_NETFILTER */
3189 static inline void nf_reset(struct sk_buff
*skb
)
3191 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3192 nf_conntrack_put(skb
->nfct
);
3195 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3196 nf_bridge_put(skb
->nf_bridge
);
3197 skb
->nf_bridge
= NULL
;
3201 static inline void nf_reset_trace(struct sk_buff
*skb
)
3203 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3208 /* Note: This doesn't put any conntrack and bridge info in dst. */
3209 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
,
3212 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3213 dst
->nfct
= src
->nfct
;
3214 nf_conntrack_get(src
->nfct
);
3216 dst
->nfctinfo
= src
->nfctinfo
;
3218 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3219 dst
->nf_bridge
= src
->nf_bridge
;
3220 nf_bridge_get(src
->nf_bridge
);
3222 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3224 dst
->nf_trace
= src
->nf_trace
;
3228 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
3230 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3231 nf_conntrack_put(dst
->nfct
);
3233 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
3234 nf_bridge_put(dst
->nf_bridge
);
3236 __nf_copy(dst
, src
, true);
3239 #ifdef CONFIG_NETWORK_SECMARK
3240 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3242 to
->secmark
= from
->secmark
;
3245 static inline void skb_init_secmark(struct sk_buff
*skb
)
3250 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
3253 static inline void skb_init_secmark(struct sk_buff
*skb
)
3257 static inline bool skb_irq_freeable(const struct sk_buff
*skb
)
3259 return !skb
->destructor
&&
3260 #if IS_ENABLED(CONFIG_XFRM)
3263 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3266 !skb
->_skb_refdst
&&
3267 !skb_has_frag_list(skb
);
3270 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
3272 skb
->queue_mapping
= queue_mapping
;
3275 static inline u16
skb_get_queue_mapping(const struct sk_buff
*skb
)
3277 return skb
->queue_mapping
;
3280 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
3282 to
->queue_mapping
= from
->queue_mapping
;
3285 static inline void skb_record_rx_queue(struct sk_buff
*skb
, u16 rx_queue
)
3287 skb
->queue_mapping
= rx_queue
+ 1;
3290 static inline u16
skb_get_rx_queue(const struct sk_buff
*skb
)
3292 return skb
->queue_mapping
- 1;
3295 static inline bool skb_rx_queue_recorded(const struct sk_buff
*skb
)
3297 return skb
->queue_mapping
!= 0;
3300 u16
__skb_tx_hash(const struct net_device
*dev
, struct sk_buff
*skb
,
3301 unsigned int num_tx_queues
);
3303 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
3312 /* Keeps track of mac header offset relative to skb->head.
3313 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3314 * For non-tunnel skb it points to skb_mac_header() and for
3315 * tunnel skb it points to outer mac header.
3316 * Keeps track of level of encapsulation of network headers.
3323 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3325 static inline int skb_tnl_header_len(const struct sk_buff
*inner_skb
)
3327 return (skb_mac_header(inner_skb
) - inner_skb
->head
) -
3328 SKB_GSO_CB(inner_skb
)->mac_offset
;
3331 static inline int gso_pskb_expand_head(struct sk_buff
*skb
, int extra
)
3333 int new_headroom
, headroom
;
3336 headroom
= skb_headroom(skb
);
3337 ret
= pskb_expand_head(skb
, extra
, 0, GFP_ATOMIC
);
3341 new_headroom
= skb_headroom(skb
);
3342 SKB_GSO_CB(skb
)->mac_offset
+= (new_headroom
- headroom
);
3346 /* Compute the checksum for a gso segment. First compute the checksum value
3347 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3348 * then add in skb->csum (checksum from csum_start to end of packet).
3349 * skb->csum and csum_start are then updated to reflect the checksum of the
3350 * resultant packet starting from the transport header-- the resultant checksum
3351 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3354 static inline __sum16
gso_make_checksum(struct sk_buff
*skb
, __wsum res
)
3356 int plen
= SKB_GSO_CB(skb
)->csum_start
- skb_headroom(skb
) -
3357 skb_transport_offset(skb
);
3360 csum
= csum_fold(csum_partial(skb_transport_header(skb
),
3363 SKB_GSO_CB(skb
)->csum_start
-= plen
;
3368 static inline bool skb_is_gso(const struct sk_buff
*skb
)
3370 return skb_shinfo(skb
)->gso_size
;
3373 /* Note: Should be called only if skb_is_gso(skb) is true */
3374 static inline bool skb_is_gso_v6(const struct sk_buff
*skb
)
3376 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
3379 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
3381 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
3383 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3384 * wanted then gso_type will be set. */
3385 const struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
3387 if (skb_is_nonlinear(skb
) && shinfo
->gso_size
!= 0 &&
3388 unlikely(shinfo
->gso_type
== 0)) {
3389 __skb_warn_lro_forwarding(skb
);
3395 static inline void skb_forward_csum(struct sk_buff
*skb
)
3397 /* Unfortunately we don't support this one. Any brave souls? */
3398 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
3399 skb
->ip_summed
= CHECKSUM_NONE
;
3403 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3404 * @skb: skb to check
3406 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3407 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3408 * use this helper, to document places where we make this assertion.
3410 static inline void skb_checksum_none_assert(const struct sk_buff
*skb
)
3413 BUG_ON(skb
->ip_summed
!= CHECKSUM_NONE
);
3417 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
3419 int skb_checksum_setup(struct sk_buff
*skb
, bool recalculate
);
3421 u32
skb_get_poff(const struct sk_buff
*skb
);
3422 u32
__skb_get_poff(const struct sk_buff
*skb
, void *data
,
3423 const struct flow_keys
*keys
, int hlen
);
3426 * skb_head_is_locked - Determine if the skb->head is locked down
3427 * @skb: skb to check
3429 * The head on skbs build around a head frag can be removed if they are
3430 * not cloned. This function returns true if the skb head is locked down
3431 * due to either being allocated via kmalloc, or by being a clone with
3432 * multiple references to the head.
3434 static inline bool skb_head_is_locked(const struct sk_buff
*skb
)
3436 return !skb
->head_frag
|| skb_cloned(skb
);
3440 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3444 * skb_gso_network_seglen is used to determine the real size of the
3445 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3447 * The MAC/L2 header is not accounted for.
3449 static inline unsigned int skb_gso_network_seglen(const struct sk_buff
*skb
)
3451 unsigned int hdr_len
= skb_transport_header(skb
) -
3452 skb_network_header(skb
);
3453 return hdr_len
+ skb_gso_transport_seglen(skb
);
3455 #endif /* __KERNEL__ */
3456 #endif /* _LINUX_SKBUFF_H */