1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * Definitions for the 'struct sk_buff' memory handlers.
6 * Alan Cox, <gw4pts@gw4pts.ampr.org>
7 * Florian La Roche, <rzsfl@rz.uni-sb.de>
10 #ifndef _LINUX_SKBUFF_H
11 #define _LINUX_SKBUFF_H
13 #include <linux/kernel.h>
14 #include <linux/compiler.h>
15 #include <linux/time.h>
16 #include <linux/bug.h>
17 #include <linux/bvec.h>
18 #include <linux/cache.h>
19 #include <linux/rbtree.h>
20 #include <linux/socket.h>
21 #include <linux/refcount.h>
23 #include <linux/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <net/checksum.h>
27 #include <linux/rcupdate.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/netdev_features.h>
30 #include <net/flow_dissector.h>
31 #include <linux/in6.h>
32 #include <linux/if_packet.h>
33 #include <linux/llist.h>
35 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
36 #include <linux/netfilter/nf_conntrack_common.h>
38 #include <net/net_debug.h>
39 #include <net/dropreason-core.h>
40 #include <net/netmem.h>
45 * The interface for checksum offload between the stack and networking drivers
48 * IP checksum related features
49 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
51 * Drivers advertise checksum offload capabilities in the features of a device.
52 * From the stack's point of view these are capabilities offered by the driver.
53 * A driver typically only advertises features that it is capable of offloading
56 * .. flat-table:: Checksum related device features
59 * * - %NETIF_F_HW_CSUM
60 * - The driver (or its device) is able to compute one
61 * IP (one's complement) checksum for any combination
62 * of protocols or protocol layering. The checksum is
63 * computed and set in a packet per the CHECKSUM_PARTIAL
64 * interface (see below).
66 * * - %NETIF_F_IP_CSUM
67 * - Driver (device) is only able to checksum plain
68 * TCP or UDP packets over IPv4. These are specifically
69 * unencapsulated packets of the form IPv4|TCP or
70 * IPv4|UDP where the Protocol field in the IPv4 header
71 * is TCP or UDP. The IPv4 header may contain IP options.
72 * This feature cannot be set in features for a device
73 * with NETIF_F_HW_CSUM also set. This feature is being
74 * DEPRECATED (see below).
76 * * - %NETIF_F_IPV6_CSUM
77 * - Driver (device) is only able to checksum plain
78 * TCP or UDP packets over IPv6. These are specifically
79 * unencapsulated packets of the form IPv6|TCP or
80 * IPv6|UDP where the Next Header field in the IPv6
81 * header is either TCP or UDP. IPv6 extension headers
82 * are not supported with this feature. This feature
83 * cannot be set in features for a device with
84 * NETIF_F_HW_CSUM also set. This feature is being
85 * DEPRECATED (see below).
88 * - Driver (device) performs receive checksum offload.
89 * This flag is only used to disable the RX checksum
90 * feature for a device. The stack will accept receive
91 * checksum indication in packets received on a device
92 * regardless of whether NETIF_F_RXCSUM is set.
94 * Checksumming of received packets by device
95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
97 * Indication of checksum verification is set in &sk_buff.ip_summed.
98 * Possible values are:
102 * Device did not checksum this packet e.g. due to lack of capabilities.
103 * The packet contains full (though not verified) checksum in packet but
104 * not in skb->csum. Thus, skb->csum is undefined in this case.
106 * - %CHECKSUM_UNNECESSARY
108 * The hardware you're dealing with doesn't calculate the full checksum
109 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
110 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
111 * if their checksums are okay. &sk_buff.csum is still undefined in this case
112 * though. A driver or device must never modify the checksum field in the
113 * packet even if checksum is verified.
115 * %CHECKSUM_UNNECESSARY is applicable to following protocols:
117 * - TCP: IPv6 and IPv4.
118 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
119 * zero UDP checksum for either IPv4 or IPv6, the networking stack
120 * may perform further validation in this case.
121 * - GRE: only if the checksum is present in the header.
122 * - SCTP: indicates the CRC in SCTP header has been validated.
123 * - FCOE: indicates the CRC in FC frame has been validated.
125 * &sk_buff.csum_level indicates the number of consecutive checksums found in
126 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
127 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
128 * and a device is able to verify the checksums for UDP (possibly zero),
129 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
130 * two. If the device were only able to verify the UDP checksum and not
131 * GRE, either because it doesn't support GRE checksum or because GRE
132 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
133 * not considered in this case).
135 * - %CHECKSUM_COMPLETE
137 * This is the most generic way. The device supplied checksum of the _whole_
138 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
139 * hardware doesn't need to parse L3/L4 headers to implement this.
143 * - Even if device supports only some protocols, but is able to produce
144 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
145 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
147 * - %CHECKSUM_PARTIAL
149 * A checksum is set up to be offloaded to a device as described in the
150 * output description for CHECKSUM_PARTIAL. This may occur on a packet
151 * received directly from another Linux OS, e.g., a virtualized Linux kernel
152 * on the same host, or it may be set in the input path in GRO or remote
153 * checksum offload. For the purposes of checksum verification, the checksum
154 * referred to by skb->csum_start + skb->csum_offset and any preceding
155 * checksums in the packet are considered verified. Any checksums in the
156 * packet that are after the checksum being offloaded are not considered to
159 * Checksumming on transmit for non-GSO
160 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
162 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
165 * - %CHECKSUM_PARTIAL
167 * The driver is required to checksum the packet as seen by hard_start_xmit()
168 * from &sk_buff.csum_start up to the end, and to record/write the checksum at
169 * offset &sk_buff.csum_start + &sk_buff.csum_offset.
170 * A driver may verify that the
171 * csum_start and csum_offset values are valid values given the length and
172 * offset of the packet, but it should not attempt to validate that the
173 * checksum refers to a legitimate transport layer checksum -- it is the
174 * purview of the stack to validate that csum_start and csum_offset are set
177 * When the stack requests checksum offload for a packet, the driver MUST
178 * ensure that the checksum is set correctly. A driver can either offload the
179 * checksum calculation to the device, or call skb_checksum_help (in the case
180 * that the device does not support offload for a particular checksum).
182 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
183 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
184 * checksum offload capability.
185 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
186 * on network device checksumming capabilities: if a packet does not match
187 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
188 * &sk_buff.csum_not_inet, see :ref:`crc`)
189 * is called to resolve the checksum.
193 * The skb was already checksummed by the protocol, or a checksum is not
196 * - %CHECKSUM_UNNECESSARY
198 * This has the same meaning as CHECKSUM_NONE for checksum offload on
201 * - %CHECKSUM_COMPLETE
203 * Not used in checksum output. If a driver observes a packet with this value
204 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
208 * Non-IP checksum (CRC) offloads
209 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
214 * * - %NETIF_F_SCTP_CRC
215 * - This feature indicates that a device is capable of
216 * offloading the SCTP CRC in a packet. To perform this offload the stack
217 * will set csum_start and csum_offset accordingly, set ip_summed to
218 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
219 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
220 * A driver that supports both IP checksum offload and SCTP CRC32c offload
221 * must verify which offload is configured for a packet by testing the
222 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
223 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
225 * * - %NETIF_F_FCOE_CRC
226 * - This feature indicates that a device is capable of offloading the FCOE
227 * CRC in a packet. To perform this offload the stack will set ip_summed
228 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset
229 * accordingly. Note that there is no indication in the skbuff that the
230 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
231 * both IP checksum offload and FCOE CRC offload must verify which offload
232 * is configured for a packet, presumably by inspecting packet headers.
234 * Checksumming on output with GSO
235 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
237 * In the case of a GSO packet (skb_is_gso() is true), checksum offload
238 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
239 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
240 * part of the GSO operation is implied. If a checksum is being offloaded
241 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
242 * csum_offset are set to refer to the outermost checksum being offloaded
243 * (two offloaded checksums are possible with UDP encapsulation).
246 /* Don't change this without changing skb_csum_unnecessary! */
247 #define CHECKSUM_NONE 0
248 #define CHECKSUM_UNNECESSARY 1
249 #define CHECKSUM_COMPLETE 2
250 #define CHECKSUM_PARTIAL 3
252 /* Maximum value in skb->csum_level */
253 #define SKB_MAX_CSUM_LEVEL 3
255 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
256 #define SKB_WITH_OVERHEAD(X) \
257 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
259 /* For X bytes available in skb->head, what is the minimal
260 * allocation needed, knowing struct skb_shared_info needs
263 #define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \
264 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
266 #define SKB_MAX_ORDER(X, ORDER) \
267 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
268 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
269 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
271 /* return minimum truesize of one skb containing X bytes of data */
272 #define SKB_TRUESIZE(X) ((X) + \
273 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
274 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
276 struct ahash_request;
279 struct pipe_inode_info;
287 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
288 struct nf_bridge_info {
290 BRNF_PROTO_UNCHANGED,
297 u8 sabotage_in_done:1;
301 /* always valid & non-NULL from FORWARD on, for physdev match */
302 struct net_device *physoutdev;
304 /* prerouting: detect dnat in orig/reply direction */
306 struct in6_addr ipv6_daddr;
308 /* after prerouting + nat detected: store original source
309 * mac since neigh resolution overwrites it, only used while
310 * skb is out in neigh layer.
312 char neigh_header[8];
317 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
318 /* Chain in tc_skb_ext will be used to share the tc chain with
319 * ovs recirc_id. It will be set to the current chain by tc
320 * and read by ovs to recirc_id.
332 u8 act_miss:1; /* Set if act_miss_cookie is used */
333 u8 l2_miss:1; /* Set by bridge upon FDB or MDB miss */
337 struct sk_buff_head {
338 /* These two members must be first to match sk_buff. */
339 struct_group_tagged(sk_buff_list, list,
340 struct sk_buff *next;
341 struct sk_buff *prev;
350 #ifndef CONFIG_MAX_SKB_FRAGS
351 # define CONFIG_MAX_SKB_FRAGS 17
354 #define MAX_SKB_FRAGS CONFIG_MAX_SKB_FRAGS
356 extern int sysctl_max_skb_frags;
358 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
359 * segment using its current segmentation instead.
361 #define GSO_BY_FRAGS 0xFFFF
363 typedef struct skb_frag {
370 * skb_frag_size() - Returns the size of a skb fragment
371 * @frag: skb fragment
373 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
379 * skb_frag_size_set() - Sets the size of a skb fragment
380 * @frag: skb fragment
381 * @size: size of fragment
383 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
389 * skb_frag_size_add() - Increments the size of a skb fragment by @delta
390 * @frag: skb fragment
391 * @delta: value to add
393 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
399 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
400 * @frag: skb fragment
401 * @delta: value to subtract
403 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
409 * skb_frag_must_loop - Test if %p is a high memory page
410 * @p: fragment's page
412 static inline bool skb_frag_must_loop(struct page *p)
414 #if defined(CONFIG_HIGHMEM)
415 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
422 * skb_frag_foreach_page - loop over pages in a fragment
424 * @f: skb frag to operate on
425 * @f_off: offset from start of f->netmem
426 * @f_len: length from f_off to loop over
427 * @p: (temp var) current page
428 * @p_off: (temp var) offset from start of current page,
429 * non-zero only on first page.
430 * @p_len: (temp var) length in current page,
431 * < PAGE_SIZE only on first and last page.
432 * @copied: (temp var) length so far, excluding current p_len.
434 * A fragment can hold a compound page, in which case per-page
435 * operations, notably kmap_atomic, must be called for each
438 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
439 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
440 p_off = (f_off) & (PAGE_SIZE - 1), \
441 p_len = skb_frag_must_loop(p) ? \
442 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
445 copied += p_len, p++, p_off = 0, \
446 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
449 * struct skb_shared_hwtstamps - hardware time stamps
450 * @hwtstamp: hardware time stamp transformed into duration
451 * since arbitrary point in time
452 * @netdev_data: address/cookie of network device driver used as
453 * reference to actual hardware time stamp
455 * Software time stamps generated by ktime_get_real() are stored in
458 * hwtstamps can only be compared against other hwtstamps from
461 * This structure is attached to packets as part of the
462 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
464 struct skb_shared_hwtstamps {
471 /* Definitions for tx_flags in struct skb_shared_info */
473 /* generate hardware time stamp */
474 SKBTX_HW_TSTAMP = 1 << 0,
476 /* generate software time stamp when queueing packet to NIC */
477 SKBTX_SW_TSTAMP = 1 << 1,
479 /* device driver is going to provide hardware time stamp */
480 SKBTX_IN_PROGRESS = 1 << 2,
482 /* generate hardware time stamp based on cycles if supported */
483 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3,
485 /* generate wifi status information (where possible) */
486 SKBTX_WIFI_STATUS = 1 << 4,
488 /* determine hardware time stamp based on time or cycles */
489 SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
491 /* generate software time stamp when entering packet scheduling */
492 SKBTX_SCHED_TSTAMP = 1 << 6,
495 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
497 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
498 SKBTX_HW_TSTAMP_USE_CYCLES | \
501 /* Definitions for flags in struct skb_shared_info */
503 /* use zcopy routines */
504 SKBFL_ZEROCOPY_ENABLE = BIT(0),
506 /* This indicates at least one fragment might be overwritten
507 * (as in vmsplice(), sendfile() ...)
508 * If we need to compute a TX checksum, we'll need to copy
509 * all frags to avoid possible bad checksum
511 SKBFL_SHARED_FRAG = BIT(1),
513 /* segment contains only zerocopy data and should not be
514 * charged to the kernel memory.
516 SKBFL_PURE_ZEROCOPY = BIT(2),
518 SKBFL_DONT_ORPHAN = BIT(3),
520 /* page references are managed by the ubuf_info, so it's safe to
521 * use frags only up until ubuf_info is released
523 SKBFL_MANAGED_FRAG_REFS = BIT(4),
526 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
527 #define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
528 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS)
531 * The callback notifies userspace to release buffers when skb DMA is done in
532 * lower device, the skb last reference should be 0 when calling this.
533 * The zerocopy_success argument is true if zero copy transmit occurred,
534 * false on data copy or out of memory error caused by data copy attempt.
535 * The ctx field is used to track device context.
536 * The desc field is used to track userspace buffer index.
539 void (*callback)(struct sk_buff *, struct ubuf_info *,
540 bool zerocopy_success);
545 struct ubuf_info_msgzc {
546 struct ubuf_info ubuf;
562 struct user_struct *user;
567 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
568 #define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \
571 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
572 void mm_unaccount_pinned_pages(struct mmpin *mmp);
574 /* Preserve some data across TX submission and completion.
576 * Note, this state is stored in the driver. Extending the layout
577 * might need some special care.
579 struct xsk_tx_metadata_compl {
583 /* This data is invariant across clones and lives at
584 * the end of the header data, ie. at skb->end.
586 struct skb_shared_info {
591 unsigned short gso_size;
592 /* Warning: this field is not always filled in (UFO)! */
593 unsigned short gso_segs;
594 struct sk_buff *frag_list;
596 struct skb_shared_hwtstamps hwtstamps;
597 struct xsk_tx_metadata_compl xsk_meta;
599 unsigned int gso_type;
603 * Warning : all fields before dataref are cleared in __alloc_skb()
606 unsigned int xdp_frags_size;
608 /* Intermediate layers must ensure that destructor_arg
609 * remains valid until skb destructor */
610 void * destructor_arg;
612 /* must be last field, see pskb_expand_head() */
613 skb_frag_t frags[MAX_SKB_FRAGS];
617 * DOC: dataref and headerless skbs
619 * Transport layers send out clones of payload skbs they hold for
620 * retransmissions. To allow lower layers of the stack to prepend their headers
621 * we split &skb_shared_info.dataref into two halves.
622 * The lower 16 bits count the overall number of references.
623 * The higher 16 bits indicate how many of the references are payload-only.
624 * skb_header_cloned() checks if skb is allowed to add / write the headers.
626 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
627 * (via __skb_header_release()). Any clone created from marked skb will get
628 * &sk_buff.hdr_len populated with the available headroom.
629 * If there's the only clone in existence it's able to modify the headroom
630 * at will. The sequence of calls inside the transport layer is::
634 * __skb_header_release()
636 * // send the clone down the stack
638 * This is not a very generic construct and it depends on the transport layers
639 * doing the right thing. In practice there's usually only one payload-only skb.
640 * Having multiple payload-only skbs with different lengths of hdr_len is not
641 * possible. The payload-only skbs should never leave their owner.
643 #define SKB_DATAREF_SHIFT 16
644 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
648 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
649 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
650 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
654 SKB_GSO_TCPV4 = 1 << 0,
656 /* This indicates the skb is from an untrusted source. */
657 SKB_GSO_DODGY = 1 << 1,
659 /* This indicates the tcp segment has CWR set. */
660 SKB_GSO_TCP_ECN = 1 << 2,
662 SKB_GSO_TCP_FIXEDID = 1 << 3,
664 SKB_GSO_TCPV6 = 1 << 4,
666 SKB_GSO_FCOE = 1 << 5,
668 SKB_GSO_GRE = 1 << 6,
670 SKB_GSO_GRE_CSUM = 1 << 7,
672 SKB_GSO_IPXIP4 = 1 << 8,
674 SKB_GSO_IPXIP6 = 1 << 9,
676 SKB_GSO_UDP_TUNNEL = 1 << 10,
678 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
680 SKB_GSO_PARTIAL = 1 << 12,
682 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
684 SKB_GSO_SCTP = 1 << 14,
686 SKB_GSO_ESP = 1 << 15,
688 SKB_GSO_UDP = 1 << 16,
690 SKB_GSO_UDP_L4 = 1 << 17,
692 SKB_GSO_FRAGLIST = 1 << 18,
695 #if BITS_PER_LONG > 32
696 #define NET_SKBUFF_DATA_USES_OFFSET 1
699 #ifdef NET_SKBUFF_DATA_USES_OFFSET
700 typedef unsigned int sk_buff_data_t;
702 typedef unsigned char *sk_buff_data_t;
706 * DOC: Basic sk_buff geometry
708 * struct sk_buff itself is a metadata structure and does not hold any packet
709 * data. All the data is held in associated buffers.
711 * &sk_buff.head points to the main "head" buffer. The head buffer is divided
714 * - data buffer, containing headers and sometimes payload;
715 * this is the part of the skb operated on by the common helpers
716 * such as skb_put() or skb_pull();
717 * - shared info (struct skb_shared_info) which holds an array of pointers
718 * to read-only data in the (page, offset, length) format.
720 * Optionally &skb_shared_info.frag_list may point to another skb.
722 * Basic diagram may look like this::
727 * ,--------------------------- + head
728 * / ,----------------- + data
729 * / / ,----------- + tail
733 * -----------------------------------------------
734 * | headroom | data | tailroom | skb_shared_info |
735 * -----------------------------------------------
739 * + [page frag] ---------
740 * + frag_list --> | sk_buff |
746 * struct sk_buff - socket buffer
747 * @next: Next buffer in list
748 * @prev: Previous buffer in list
749 * @tstamp: Time we arrived/left
750 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
751 * for retransmit timer
752 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
754 * @ll_node: anchor in an llist (eg socket defer_list)
755 * @sk: Socket we are owned by
756 * @dev: Device we arrived on/are leaving by
757 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
758 * @cb: Control buffer. Free for use by every layer. Put private vars here
759 * @_skb_refdst: destination entry (with norefcount bit)
760 * @len: Length of actual data
761 * @data_len: Data length
762 * @mac_len: Length of link layer header
763 * @hdr_len: writable header length of cloned skb
764 * @csum: Checksum (must include start/offset pair)
765 * @csum_start: Offset from skb->head where checksumming should start
766 * @csum_offset: Offset from csum_start where checksum should be stored
767 * @priority: Packet queueing priority
768 * @ignore_df: allow local fragmentation
769 * @cloned: Head may be cloned (check refcnt to be sure)
770 * @ip_summed: Driver fed us an IP checksum
771 * @nohdr: Payload reference only, must not modify header
772 * @pkt_type: Packet class
773 * @fclone: skbuff clone status
774 * @ipvs_property: skbuff is owned by ipvs
775 * @inner_protocol_type: whether the inner protocol is
776 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
777 * @remcsum_offload: remote checksum offload is enabled
778 * @offload_fwd_mark: Packet was L2-forwarded in hardware
779 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
780 * @tc_skip_classify: do not classify packet. set by IFB device
781 * @tc_at_ingress: used within tc_classify to distinguish in/egress
782 * @redirected: packet was redirected by packet classifier
783 * @from_ingress: packet was redirected from the ingress path
784 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
785 * @peeked: this packet has been seen already, so stats have been
786 * done for it, don't do them again
787 * @nf_trace: netfilter packet trace flag
788 * @protocol: Packet protocol from driver
789 * @destructor: Destruct function
790 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
791 * @_sk_redir: socket redirection information for skmsg
792 * @_nfct: Associated connection, if any (with nfctinfo bits)
793 * @skb_iif: ifindex of device we arrived on
794 * @tc_index: Traffic control index
795 * @hash: the packet hash
796 * @queue_mapping: Queue mapping for multiqueue devices
797 * @head_frag: skb was allocated from page fragments,
798 * not allocated by kmalloc() or vmalloc().
799 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
800 * @pp_recycle: mark the packet for recycling instead of freeing (implies
801 * page_pool support on driver)
802 * @active_extensions: active extensions (skb_ext_id types)
803 * @ndisc_nodetype: router type (from link layer)
804 * @ooo_okay: allow the mapping of a socket to a queue to be changed
805 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
807 * @sw_hash: indicates hash was computed in software stack
808 * @wifi_acked_valid: wifi_acked was set
809 * @wifi_acked: whether frame was acked on wifi or not
810 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
811 * @encapsulation: indicates the inner headers in the skbuff are valid
812 * @encap_hdr_csum: software checksum is needed
813 * @csum_valid: checksum is already valid
814 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
815 * @csum_complete_sw: checksum was completed by software
816 * @csum_level: indicates the number of consecutive checksums found in
817 * the packet minus one that have been verified as
818 * CHECKSUM_UNNECESSARY (max 3)
819 * @dst_pending_confirm: need to confirm neighbour
820 * @decrypted: Decrypted SKB
821 * @slow_gro: state present at GRO time, slower prepare step required
822 * @mono_delivery_time: When set, skb->tstamp has the
823 * delivery_time in mono clock base (i.e. EDT). Otherwise, the
824 * skb->tstamp has the (rcv) timestamp at ingress and
825 * delivery_time at egress.
826 * @napi_id: id of the NAPI struct this skb came from
827 * @sender_cpu: (aka @napi_id) source CPU in XPS
828 * @alloc_cpu: CPU which did the skb allocation.
829 * @secmark: security marking
830 * @mark: Generic packet mark
831 * @reserved_tailroom: (aka @mark) number of bytes of free space available
832 * at the tail of an sk_buff
833 * @vlan_all: vlan fields (proto & tci)
834 * @vlan_proto: vlan encapsulation protocol
835 * @vlan_tci: vlan tag control information
836 * @inner_protocol: Protocol (encapsulation)
837 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
838 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
839 * @inner_transport_header: Inner transport layer header (encapsulation)
840 * @inner_network_header: Network layer header (encapsulation)
841 * @inner_mac_header: Link layer header (encapsulation)
842 * @transport_header: Transport layer header
843 * @network_header: Network layer header
844 * @mac_header: Link layer header
845 * @kcov_handle: KCOV remote handle for remote coverage collection
846 * @tail: Tail pointer
848 * @head: Head of buffer
849 * @data: Data head pointer
850 * @truesize: Buffer size
851 * @users: User count - see {datagram,tcp}.c
852 * @extensions: allocated extensions, valid if active_extensions is nonzero
858 /* These two members must be first to match sk_buff_head. */
859 struct sk_buff *next;
860 struct sk_buff *prev;
863 struct net_device *dev;
864 /* Some protocols might use this space to store information,
865 * while device pointer would be NULL.
866 * UDP receive path is one user.
868 unsigned long dev_scratch;
871 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
872 struct list_head list;
873 struct llist_node ll_node;
880 u64 skb_mstamp_ns; /* earliest departure time */
883 * This is the control buffer. It is free to use for every
884 * layer. Please put your private variables there. If you
885 * want to keep them across layers you have to do a skb_clone()
886 * first. This is owned by whoever has the skb queued ATM.
888 char cb[48] __aligned(8);
892 unsigned long _skb_refdst;
893 void (*destructor)(struct sk_buff *skb);
895 struct list_head tcp_tsorted_anchor;
896 #ifdef CONFIG_NET_SOCK_MSG
897 unsigned long _sk_redir;
901 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
909 /* Following fields are _not_ copied in __copy_skb_header()
910 * Note that queue_mapping is here mostly to fill a hole.
914 /* if you move cloned around you also must adapt those constants */
915 #ifdef __BIG_ENDIAN_BITFIELD
916 #define CLONED_MASK (1 << 7)
918 #define CLONED_MASK 1
920 #define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset)
923 __u8 __cloned_offset[0];
931 pp_recycle:1; /* page_pool recycle indicator */
932 #ifdef CONFIG_SKB_EXTENSIONS
933 __u8 active_extensions;
936 /* Fields enclosed in headers group are copied
937 * using a single memcpy() in __copy_skb_header()
939 struct_group(headers,
942 __u8 __pkt_type_offset[0];
944 __u8 pkt_type:3; /* see PKT_TYPE_MAX */
946 __u8 dst_pending_confirm:1;
951 __u8 __mono_tc_offset[0];
953 __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */
954 #ifdef CONFIG_NET_XGRESS
955 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */
956 __u8 tc_skip_classify:1;
958 __u8 remcsum_offload:1;
959 __u8 csum_complete_sw:1;
961 __u8 inner_protocol_type:1;
965 #ifdef CONFIG_WIRELESS
966 __u8 wifi_acked_valid:1;
970 /* Indicates the inner headers are valid in the skbuff. */
971 __u8 encapsulation:1;
972 __u8 encap_hdr_csum:1;
974 #ifdef CONFIG_IPV6_NDISC_NODETYPE
975 __u8 ndisc_nodetype:2;
978 #if IS_ENABLED(CONFIG_IP_VS)
979 __u8 ipvs_property:1;
981 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
984 #ifdef CONFIG_NET_SWITCHDEV
985 __u8 offload_fwd_mark:1;
986 __u8 offload_l3_fwd_mark:1;
989 #ifdef CONFIG_NET_REDIRECT
992 #ifdef CONFIG_NETFILTER_SKIP_EGRESS
993 __u8 nf_skip_egress:1;
995 #ifdef CONFIG_TLS_DEVICE
999 #if IS_ENABLED(CONFIG_IP_SCTP)
1000 __u8 csum_not_inet:1;
1003 #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS)
1004 __u16 tc_index; /* traffic control index */
1026 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
1028 unsigned int napi_id;
1029 unsigned int sender_cpu;
1032 #ifdef CONFIG_NETWORK_SECMARK
1038 __u32 reserved_tailroom;
1042 __be16 inner_protocol;
1046 __u16 inner_transport_header;
1047 __u16 inner_network_header;
1048 __u16 inner_mac_header;
1051 __u16 transport_header;
1052 __u16 network_header;
1059 ); /* end headers group */
1061 /* These elements must be at the end, see alloc_skb() for details. */
1062 sk_buff_data_t tail;
1064 unsigned char *head,
1066 unsigned int truesize;
1069 #ifdef CONFIG_SKB_EXTENSIONS
1070 /* only usable after checking ->active_extensions != 0 */
1071 struct skb_ext *extensions;
1075 /* if you move pkt_type around you also must adapt those constants */
1076 #ifdef __BIG_ENDIAN_BITFIELD
1077 #define PKT_TYPE_MAX (7 << 5)
1079 #define PKT_TYPE_MAX 7
1081 #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
1083 /* if you move tc_at_ingress or mono_delivery_time
1084 * around, you also must adapt these constants.
1086 #ifdef __BIG_ENDIAN_BITFIELD
1087 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 7)
1088 #define TC_AT_INGRESS_MASK (1 << 6)
1090 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 0)
1091 #define TC_AT_INGRESS_MASK (1 << 1)
1093 #define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset)
1097 * Handling routines are only of interest to the kernel
1100 #define SKB_ALLOC_FCLONE 0x01
1101 #define SKB_ALLOC_RX 0x02
1102 #define SKB_ALLOC_NAPI 0x04
1105 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1108 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1110 return unlikely(skb->pfmemalloc);
1114 * skb might have a dst pointer attached, refcounted or not.
1115 * _skb_refdst low order bit is set if refcount was _not_ taken
1117 #define SKB_DST_NOREF 1UL
1118 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
1121 * skb_dst - returns skb dst_entry
1124 * Returns skb dst_entry, regardless of reference taken or not.
1126 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
1128 /* If refdst was not refcounted, check we still are in a
1129 * rcu_read_lock section
1131 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1132 !rcu_read_lock_held() &&
1133 !rcu_read_lock_bh_held());
1134 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1138 * skb_dst_set - sets skb dst
1142 * Sets skb dst, assuming a reference was taken on dst and should
1143 * be released by skb_dst_drop()
1145 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
1147 skb->slow_gro |= !!dst;
1148 skb->_skb_refdst = (unsigned long)dst;
1152 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1156 * Sets skb dst, assuming a reference was not taken on dst.
1157 * If dst entry is cached, we do not take reference and dst_release
1158 * will be avoided by refdst_drop. If dst entry is not cached, we take
1159 * reference, so that last dst_release can destroy the dst immediately.
1161 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1163 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1164 skb->slow_gro |= !!dst;
1165 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1169 * skb_dst_is_noref - Test if skb dst isn't refcounted
1172 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1174 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1178 * skb_rtable - Returns the skb &rtable
1181 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
1183 return (struct rtable *)skb_dst(skb);
1186 /* For mangling skb->pkt_type from user space side from applications
1187 * such as nft, tc, etc, we only allow a conservative subset of
1188 * possible pkt_types to be set.
1190 static inline bool skb_pkt_type_ok(u32 ptype)
1192 return ptype <= PACKET_OTHERHOST;
1196 * skb_napi_id - Returns the skb's NAPI id
1199 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1201 #ifdef CONFIG_NET_RX_BUSY_POLL
1202 return skb->napi_id;
1208 static inline bool skb_wifi_acked_valid(const struct sk_buff *skb)
1210 #ifdef CONFIG_WIRELESS
1211 return skb->wifi_acked_valid;
1218 * skb_unref - decrement the skb's reference count
1221 * Returns true if we can free the skb.
1223 static inline bool skb_unref(struct sk_buff *skb)
1227 if (likely(refcount_read(&skb->users) == 1))
1229 else if (likely(!refcount_dec_and_test(&skb->users)))
1235 static inline bool skb_data_unref(const struct sk_buff *skb,
1236 struct skb_shared_info *shinfo)
1243 bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1;
1245 if (atomic_read(&shinfo->dataref) == bias)
1247 else if (atomic_sub_return(bias, &shinfo->dataref))
1254 kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason);
1257 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1258 * @skb: buffer to free
1260 static inline void kfree_skb(struct sk_buff *skb)
1262 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
1265 void skb_release_head_state(struct sk_buff *skb);
1266 void kfree_skb_list_reason(struct sk_buff *segs,
1267 enum skb_drop_reason reason);
1268 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1269 void skb_tx_error(struct sk_buff *skb);
1271 static inline void kfree_skb_list(struct sk_buff *segs)
1273 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED);
1276 #ifdef CONFIG_TRACEPOINTS
1277 void consume_skb(struct sk_buff *skb);
1279 static inline void consume_skb(struct sk_buff *skb)
1281 return kfree_skb(skb);
1285 void __consume_stateless_skb(struct sk_buff *skb);
1286 void __kfree_skb(struct sk_buff *skb);
1288 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1289 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1290 bool *fragstolen, int *delta_truesize);
1292 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1294 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1295 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1296 struct sk_buff *build_skb_around(struct sk_buff *skb,
1297 void *data, unsigned int frag_size);
1298 void skb_attempt_defer_free(struct sk_buff *skb);
1300 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1301 struct sk_buff *slab_build_skb(void *data);
1304 * alloc_skb - allocate a network buffer
1305 * @size: size to allocate
1306 * @priority: allocation mask
1308 * This function is a convenient wrapper around __alloc_skb().
1310 static inline struct sk_buff *alloc_skb(unsigned int size,
1313 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1316 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1317 unsigned long data_len,
1321 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1323 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1324 struct sk_buff_fclones {
1325 struct sk_buff skb1;
1327 struct sk_buff skb2;
1329 refcount_t fclone_ref;
1333 * skb_fclone_busy - check if fclone is busy
1337 * Returns true if skb is a fast clone, and its clone is not freed.
1338 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1339 * so we also check that didn't happen.
1341 static inline bool skb_fclone_busy(const struct sock *sk,
1342 const struct sk_buff *skb)
1344 const struct sk_buff_fclones *fclones;
1346 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1348 return skb->fclone == SKB_FCLONE_ORIG &&
1349 refcount_read(&fclones->fclone_ref) > 1 &&
1350 READ_ONCE(fclones->skb2.sk) == sk;
1354 * alloc_skb_fclone - allocate a network buffer from fclone cache
1355 * @size: size to allocate
1356 * @priority: allocation mask
1358 * This function is a convenient wrapper around __alloc_skb().
1360 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1363 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1366 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1367 void skb_headers_offset_update(struct sk_buff *skb, int off);
1368 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1369 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1370 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1371 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1372 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1373 gfp_t gfp_mask, bool fclone);
1374 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1377 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1380 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1381 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1382 unsigned int headroom);
1383 struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom);
1384 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1385 int newtailroom, gfp_t priority);
1386 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1387 int offset, int len);
1388 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1389 int offset, int len);
1390 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1391 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1394 * skb_pad - zero pad the tail of an skb
1395 * @skb: buffer to pad
1396 * @pad: space to pad
1398 * Ensure that a buffer is followed by a padding area that is zero
1399 * filled. Used by network drivers which may DMA or transfer data
1400 * beyond the buffer end onto the wire.
1402 * May return error in out of memory cases. The skb is freed on error.
1404 static inline int skb_pad(struct sk_buff *skb, int pad)
1406 return __skb_pad(skb, pad, true);
1408 #define dev_kfree_skb(a) consume_skb(a)
1410 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1411 int offset, size_t size, size_t max_frags);
1413 struct skb_seq_state {
1417 __u32 stepped_offset;
1418 struct sk_buff *root_skb;
1419 struct sk_buff *cur_skb;
1424 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1425 unsigned int to, struct skb_seq_state *st);
1426 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1427 struct skb_seq_state *st);
1428 void skb_abort_seq_read(struct skb_seq_state *st);
1430 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1431 unsigned int to, struct ts_config *config);
1434 * Packet hash types specify the type of hash in skb_set_hash.
1436 * Hash types refer to the protocol layer addresses which are used to
1437 * construct a packet's hash. The hashes are used to differentiate or identify
1438 * flows of the protocol layer for the hash type. Hash types are either
1439 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1441 * Properties of hashes:
1443 * 1) Two packets in different flows have different hash values
1444 * 2) Two packets in the same flow should have the same hash value
1446 * A hash at a higher layer is considered to be more specific. A driver should
1447 * set the most specific hash possible.
1449 * A driver cannot indicate a more specific hash than the layer at which a hash
1450 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1452 * A driver may indicate a hash level which is less specific than the
1453 * actual layer the hash was computed on. For instance, a hash computed
1454 * at L4 may be considered an L3 hash. This should only be done if the
1455 * driver can't unambiguously determine that the HW computed the hash at
1456 * the higher layer. Note that the "should" in the second property above
1459 enum pkt_hash_types {
1460 PKT_HASH_TYPE_NONE, /* Undefined type */
1461 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1462 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1463 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1466 static inline void skb_clear_hash(struct sk_buff *skb)
1473 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1476 skb_clear_hash(skb);
1480 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1482 skb->l4_hash = is_l4;
1483 skb->sw_hash = is_sw;
1488 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1490 /* Used by drivers to set hash from HW */
1491 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1495 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1497 __skb_set_hash(skb, hash, true, is_l4);
1500 void __skb_get_hash(struct sk_buff *skb);
1501 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1502 u32 skb_get_poff(const struct sk_buff *skb);
1503 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1504 const struct flow_keys_basic *keys, int hlen);
1505 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1506 const void *data, int hlen_proto);
1508 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1509 int thoff, u8 ip_proto)
1511 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1514 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1515 const struct flow_dissector_key *key,
1516 unsigned int key_count);
1518 struct bpf_flow_dissector;
1519 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1520 __be16 proto, int nhoff, int hlen, unsigned int flags);
1522 bool __skb_flow_dissect(const struct net *net,
1523 const struct sk_buff *skb,
1524 struct flow_dissector *flow_dissector,
1525 void *target_container, const void *data,
1526 __be16 proto, int nhoff, int hlen, unsigned int flags);
1528 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1529 struct flow_dissector *flow_dissector,
1530 void *target_container, unsigned int flags)
1532 return __skb_flow_dissect(NULL, skb, flow_dissector,
1533 target_container, NULL, 0, 0, 0, flags);
1536 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1537 struct flow_keys *flow,
1540 memset(flow, 0, sizeof(*flow));
1541 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1542 flow, NULL, 0, 0, 0, flags);
1546 skb_flow_dissect_flow_keys_basic(const struct net *net,
1547 const struct sk_buff *skb,
1548 struct flow_keys_basic *flow,
1549 const void *data, __be16 proto,
1550 int nhoff, int hlen, unsigned int flags)
1552 memset(flow, 0, sizeof(*flow));
1553 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1554 data, proto, nhoff, hlen, flags);
1557 void skb_flow_dissect_meta(const struct sk_buff *skb,
1558 struct flow_dissector *flow_dissector,
1559 void *target_container);
1561 /* Gets a skb connection tracking info, ctinfo map should be a
1562 * map of mapsize to translate enum ip_conntrack_info states
1566 skb_flow_dissect_ct(const struct sk_buff *skb,
1567 struct flow_dissector *flow_dissector,
1568 void *target_container,
1569 u16 *ctinfo_map, size_t mapsize,
1570 bool post_ct, u16 zone);
1572 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1573 struct flow_dissector *flow_dissector,
1574 void *target_container);
1576 void skb_flow_dissect_hash(const struct sk_buff *skb,
1577 struct flow_dissector *flow_dissector,
1578 void *target_container);
1580 static inline __u32 skb_get_hash(struct sk_buff *skb)
1582 if (!skb->l4_hash && !skb->sw_hash)
1583 __skb_get_hash(skb);
1588 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1590 if (!skb->l4_hash && !skb->sw_hash) {
1591 struct flow_keys keys;
1592 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1594 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1600 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1601 const siphash_key_t *perturb);
1603 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1608 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1610 to->hash = from->hash;
1611 to->sw_hash = from->sw_hash;
1612 to->l4_hash = from->l4_hash;
1615 static inline int skb_cmp_decrypted(const struct sk_buff *skb1,
1616 const struct sk_buff *skb2)
1618 #ifdef CONFIG_TLS_DEVICE
1619 return skb2->decrypted - skb1->decrypted;
1625 static inline void skb_copy_decrypted(struct sk_buff *to,
1626 const struct sk_buff *from)
1628 #ifdef CONFIG_TLS_DEVICE
1629 to->decrypted = from->decrypted;
1633 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1634 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1636 return skb->head + skb->end;
1639 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1644 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1649 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1654 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1656 return skb->end - skb->head;
1659 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1661 skb->end = skb->head + offset;
1665 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
1666 struct ubuf_info *uarg);
1668 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1670 void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
1673 int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
1674 struct sk_buff *skb, struct iov_iter *from,
1677 static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1678 struct msghdr *msg, int len)
1680 return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len);
1683 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
1684 struct msghdr *msg, int len,
1685 struct ubuf_info *uarg);
1688 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1690 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1692 return &skb_shinfo(skb)->hwtstamps;
1695 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1697 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1699 return is_zcopy ? skb_uarg(skb) : NULL;
1702 static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1704 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1707 static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1709 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1712 static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1713 const struct sk_buff *skb2)
1715 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
1718 static inline void net_zcopy_get(struct ubuf_info *uarg)
1720 refcount_inc(&uarg->refcnt);
1723 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1725 skb_shinfo(skb)->destructor_arg = uarg;
1726 skb_shinfo(skb)->flags |= uarg->flags;
1729 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1732 if (skb && uarg && !skb_zcopy(skb)) {
1733 if (unlikely(have_ref && *have_ref))
1736 net_zcopy_get(uarg);
1737 skb_zcopy_init(skb, uarg);
1741 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1743 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1744 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1747 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1749 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1752 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1754 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1757 static inline void net_zcopy_put(struct ubuf_info *uarg)
1760 uarg->callback(NULL, uarg, true);
1763 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1766 if (uarg->callback == msg_zerocopy_callback)
1767 msg_zerocopy_put_abort(uarg, have_uref);
1769 net_zcopy_put(uarg);
1773 /* Release a reference on a zerocopy structure */
1774 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1776 struct ubuf_info *uarg = skb_zcopy(skb);
1779 if (!skb_zcopy_is_nouarg(skb))
1780 uarg->callback(skb, uarg, zerocopy_success);
1782 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1786 void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1788 static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1790 if (unlikely(skb_zcopy_managed(skb)))
1791 __skb_zcopy_downgrade_managed(skb);
1794 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1799 static inline void skb_poison_list(struct sk_buff *skb)
1801 #ifdef CONFIG_DEBUG_NET
1802 skb->next = SKB_LIST_POISON_NEXT;
1806 /* Iterate through singly-linked GSO fragments of an skb. */
1807 #define skb_list_walk_safe(first, skb, next_skb) \
1808 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1809 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1811 static inline void skb_list_del_init(struct sk_buff *skb)
1813 __list_del_entry(&skb->list);
1814 skb_mark_not_on_list(skb);
1818 * skb_queue_empty - check if a queue is empty
1821 * Returns true if the queue is empty, false otherwise.
1823 static inline int skb_queue_empty(const struct sk_buff_head *list)
1825 return list->next == (const struct sk_buff *) list;
1829 * skb_queue_empty_lockless - check if a queue is empty
1832 * Returns true if the queue is empty, false otherwise.
1833 * This variant can be used in lockless contexts.
1835 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1837 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1842 * skb_queue_is_last - check if skb is the last entry in the queue
1846 * Returns true if @skb is the last buffer on the list.
1848 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1849 const struct sk_buff *skb)
1851 return skb->next == (const struct sk_buff *) list;
1855 * skb_queue_is_first - check if skb is the first entry in the queue
1859 * Returns true if @skb is the first buffer on the list.
1861 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1862 const struct sk_buff *skb)
1864 return skb->prev == (const struct sk_buff *) list;
1868 * skb_queue_next - return the next packet in the queue
1870 * @skb: current buffer
1872 * Return the next packet in @list after @skb. It is only valid to
1873 * call this if skb_queue_is_last() evaluates to false.
1875 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1876 const struct sk_buff *skb)
1878 /* This BUG_ON may seem severe, but if we just return then we
1879 * are going to dereference garbage.
1881 BUG_ON(skb_queue_is_last(list, skb));
1886 * skb_queue_prev - return the prev packet in the queue
1888 * @skb: current buffer
1890 * Return the prev packet in @list before @skb. It is only valid to
1891 * call this if skb_queue_is_first() evaluates to false.
1893 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1894 const struct sk_buff *skb)
1896 /* This BUG_ON may seem severe, but if we just return then we
1897 * are going to dereference garbage.
1899 BUG_ON(skb_queue_is_first(list, skb));
1904 * skb_get - reference buffer
1905 * @skb: buffer to reference
1907 * Makes another reference to a socket buffer and returns a pointer
1910 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1912 refcount_inc(&skb->users);
1917 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1921 * skb_cloned - is the buffer a clone
1922 * @skb: buffer to check
1924 * Returns true if the buffer was generated with skb_clone() and is
1925 * one of multiple shared copies of the buffer. Cloned buffers are
1926 * shared data so must not be written to under normal circumstances.
1928 static inline int skb_cloned(const struct sk_buff *skb)
1930 return skb->cloned &&
1931 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1934 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1936 might_sleep_if(gfpflags_allow_blocking(pri));
1938 if (skb_cloned(skb))
1939 return pskb_expand_head(skb, 0, 0, pri);
1944 /* This variant of skb_unclone() makes sure skb->truesize
1945 * and skb_end_offset() are not changed, whenever a new skb->head is needed.
1947 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
1948 * when various debugging features are in place.
1950 int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
1951 static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
1953 might_sleep_if(gfpflags_allow_blocking(pri));
1955 if (skb_cloned(skb))
1956 return __skb_unclone_keeptruesize(skb, pri);
1961 * skb_header_cloned - is the header a clone
1962 * @skb: buffer to check
1964 * Returns true if modifying the header part of the buffer requires
1965 * the data to be copied.
1967 static inline int skb_header_cloned(const struct sk_buff *skb)
1974 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1975 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1976 return dataref != 1;
1979 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1981 might_sleep_if(gfpflags_allow_blocking(pri));
1983 if (skb_header_cloned(skb))
1984 return pskb_expand_head(skb, 0, 0, pri);
1990 * __skb_header_release() - allow clones to use the headroom
1991 * @skb: buffer to operate on
1993 * See "DOC: dataref and headerless skbs".
1995 static inline void __skb_header_release(struct sk_buff *skb)
1998 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
2003 * skb_shared - is the buffer shared
2004 * @skb: buffer to check
2006 * Returns true if more than one person has a reference to this
2009 static inline int skb_shared(const struct sk_buff *skb)
2011 return refcount_read(&skb->users) != 1;
2015 * skb_share_check - check if buffer is shared and if so clone it
2016 * @skb: buffer to check
2017 * @pri: priority for memory allocation
2019 * If the buffer is shared the buffer is cloned and the old copy
2020 * drops a reference. A new clone with a single reference is returned.
2021 * If the buffer is not shared the original buffer is returned. When
2022 * being called from interrupt status or with spinlocks held pri must
2025 * NULL is returned on a memory allocation failure.
2027 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
2029 might_sleep_if(gfpflags_allow_blocking(pri));
2030 if (skb_shared(skb)) {
2031 struct sk_buff *nskb = skb_clone(skb, pri);
2043 * Copy shared buffers into a new sk_buff. We effectively do COW on
2044 * packets to handle cases where we have a local reader and forward
2045 * and a couple of other messy ones. The normal one is tcpdumping
2046 * a packet that's being forwarded.
2050 * skb_unshare - make a copy of a shared buffer
2051 * @skb: buffer to check
2052 * @pri: priority for memory allocation
2054 * If the socket buffer is a clone then this function creates a new
2055 * copy of the data, drops a reference count on the old copy and returns
2056 * the new copy with the reference count at 1. If the buffer is not a clone
2057 * the original buffer is returned. When called with a spinlock held or
2058 * from interrupt state @pri must be %GFP_ATOMIC
2060 * %NULL is returned on a memory allocation failure.
2062 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
2065 might_sleep_if(gfpflags_allow_blocking(pri));
2066 if (skb_cloned(skb)) {
2067 struct sk_buff *nskb = skb_copy(skb, pri);
2069 /* Free our shared copy */
2080 * skb_peek - peek at the head of an &sk_buff_head
2081 * @list_: list to peek at
2083 * Peek an &sk_buff. Unlike most other operations you _MUST_
2084 * be careful with this one. A peek leaves the buffer on the
2085 * list and someone else may run off with it. You must hold
2086 * the appropriate locks or have a private queue to do this.
2088 * Returns %NULL for an empty list or a pointer to the head element.
2089 * The reference count is not incremented and the reference is therefore
2090 * volatile. Use with caution.
2092 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
2094 struct sk_buff *skb = list_->next;
2096 if (skb == (struct sk_buff *)list_)
2102 * __skb_peek - peek at the head of a non-empty &sk_buff_head
2103 * @list_: list to peek at
2105 * Like skb_peek(), but the caller knows that the list is not empty.
2107 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
2113 * skb_peek_next - peek skb following the given one from a queue
2114 * @skb: skb to start from
2115 * @list_: list to peek at
2117 * Returns %NULL when the end of the list is met or a pointer to the
2118 * next element. The reference count is not incremented and the
2119 * reference is therefore volatile. Use with caution.
2121 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
2122 const struct sk_buff_head *list_)
2124 struct sk_buff *next = skb->next;
2126 if (next == (struct sk_buff *)list_)
2132 * skb_peek_tail - peek at the tail of an &sk_buff_head
2133 * @list_: list to peek at
2135 * Peek an &sk_buff. Unlike most other operations you _MUST_
2136 * be careful with this one. A peek leaves the buffer on the
2137 * list and someone else may run off with it. You must hold
2138 * the appropriate locks or have a private queue to do this.
2140 * Returns %NULL for an empty list or a pointer to the tail element.
2141 * The reference count is not incremented and the reference is therefore
2142 * volatile. Use with caution.
2144 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
2146 struct sk_buff *skb = READ_ONCE(list_->prev);
2148 if (skb == (struct sk_buff *)list_)
2155 * skb_queue_len - get queue length
2156 * @list_: list to measure
2158 * Return the length of an &sk_buff queue.
2160 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2166 * skb_queue_len_lockless - get queue length
2167 * @list_: list to measure
2169 * Return the length of an &sk_buff queue.
2170 * This variant can be used in lockless contexts.
2172 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2174 return READ_ONCE(list_->qlen);
2178 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2179 * @list: queue to initialize
2181 * This initializes only the list and queue length aspects of
2182 * an sk_buff_head object. This allows to initialize the list
2183 * aspects of an sk_buff_head without reinitializing things like
2184 * the spinlock. It can also be used for on-stack sk_buff_head
2185 * objects where the spinlock is known to not be used.
2187 static inline void __skb_queue_head_init(struct sk_buff_head *list)
2189 list->prev = list->next = (struct sk_buff *)list;
2194 * This function creates a split out lock class for each invocation;
2195 * this is needed for now since a whole lot of users of the skb-queue
2196 * infrastructure in drivers have different locking usage (in hardirq)
2197 * than the networking core (in softirq only). In the long run either the
2198 * network layer or drivers should need annotation to consolidate the
2199 * main types of usage into 3 classes.
2201 static inline void skb_queue_head_init(struct sk_buff_head *list)
2203 spin_lock_init(&list->lock);
2204 __skb_queue_head_init(list);
2207 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2208 struct lock_class_key *class)
2210 skb_queue_head_init(list);
2211 lockdep_set_class(&list->lock, class);
2215 * Insert an sk_buff on a list.
2217 * The "__skb_xxxx()" functions are the non-atomic ones that
2218 * can only be called with interrupts disabled.
2220 static inline void __skb_insert(struct sk_buff *newsk,
2221 struct sk_buff *prev, struct sk_buff *next,
2222 struct sk_buff_head *list)
2224 /* See skb_queue_empty_lockless() and skb_peek_tail()
2225 * for the opposite READ_ONCE()
2227 WRITE_ONCE(newsk->next, next);
2228 WRITE_ONCE(newsk->prev, prev);
2229 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2230 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2231 WRITE_ONCE(list->qlen, list->qlen + 1);
2234 static inline void __skb_queue_splice(const struct sk_buff_head *list,
2235 struct sk_buff *prev,
2236 struct sk_buff *next)
2238 struct sk_buff *first = list->next;
2239 struct sk_buff *last = list->prev;
2241 WRITE_ONCE(first->prev, prev);
2242 WRITE_ONCE(prev->next, first);
2244 WRITE_ONCE(last->next, next);
2245 WRITE_ONCE(next->prev, last);
2249 * skb_queue_splice - join two skb lists, this is designed for stacks
2250 * @list: the new list to add
2251 * @head: the place to add it in the first list
2253 static inline void skb_queue_splice(const struct sk_buff_head *list,
2254 struct sk_buff_head *head)
2256 if (!skb_queue_empty(list)) {
2257 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2258 head->qlen += list->qlen;
2263 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2264 * @list: the new list to add
2265 * @head: the place to add it in the first list
2267 * The list at @list is reinitialised
2269 static inline void skb_queue_splice_init(struct sk_buff_head *list,
2270 struct sk_buff_head *head)
2272 if (!skb_queue_empty(list)) {
2273 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2274 head->qlen += list->qlen;
2275 __skb_queue_head_init(list);
2280 * skb_queue_splice_tail - join two skb lists, each list being a queue
2281 * @list: the new list to add
2282 * @head: the place to add it in the first list
2284 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2285 struct sk_buff_head *head)
2287 if (!skb_queue_empty(list)) {
2288 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2289 head->qlen += list->qlen;
2294 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2295 * @list: the new list to add
2296 * @head: the place to add it in the first list
2298 * Each of the lists is a queue.
2299 * The list at @list is reinitialised
2301 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2302 struct sk_buff_head *head)
2304 if (!skb_queue_empty(list)) {
2305 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2306 head->qlen += list->qlen;
2307 __skb_queue_head_init(list);
2312 * __skb_queue_after - queue a buffer at the list head
2313 * @list: list to use
2314 * @prev: place after this buffer
2315 * @newsk: buffer to queue
2317 * Queue a buffer int the middle of a list. This function takes no locks
2318 * and you must therefore hold required locks before calling it.
2320 * A buffer cannot be placed on two lists at the same time.
2322 static inline void __skb_queue_after(struct sk_buff_head *list,
2323 struct sk_buff *prev,
2324 struct sk_buff *newsk)
2326 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list);
2329 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2330 struct sk_buff_head *list);
2332 static inline void __skb_queue_before(struct sk_buff_head *list,
2333 struct sk_buff *next,
2334 struct sk_buff *newsk)
2336 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list);
2340 * __skb_queue_head - queue a buffer at the list head
2341 * @list: list to use
2342 * @newsk: buffer to queue
2344 * Queue a buffer at the start of a list. This function takes no locks
2345 * and you must therefore hold required locks before calling it.
2347 * A buffer cannot be placed on two lists at the same time.
2349 static inline void __skb_queue_head(struct sk_buff_head *list,
2350 struct sk_buff *newsk)
2352 __skb_queue_after(list, (struct sk_buff *)list, newsk);
2354 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2357 * __skb_queue_tail - queue a buffer at the list tail
2358 * @list: list to use
2359 * @newsk: buffer to queue
2361 * Queue a buffer at the end of a list. This function takes no locks
2362 * and you must therefore hold required locks before calling it.
2364 * A buffer cannot be placed on two lists at the same time.
2366 static inline void __skb_queue_tail(struct sk_buff_head *list,
2367 struct sk_buff *newsk)
2369 __skb_queue_before(list, (struct sk_buff *)list, newsk);
2371 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2374 * remove sk_buff from list. _Must_ be called atomically, and with
2377 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
2378 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2380 struct sk_buff *next, *prev;
2382 WRITE_ONCE(list->qlen, list->qlen - 1);
2385 skb->next = skb->prev = NULL;
2386 WRITE_ONCE(next->prev, prev);
2387 WRITE_ONCE(prev->next, next);
2391 * __skb_dequeue - remove from the head of the queue
2392 * @list: list to dequeue from
2394 * Remove the head of the list. This function does not take any locks
2395 * so must be used with appropriate locks held only. The head item is
2396 * returned or %NULL if the list is empty.
2398 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2400 struct sk_buff *skb = skb_peek(list);
2402 __skb_unlink(skb, list);
2405 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2408 * __skb_dequeue_tail - remove from the tail of the queue
2409 * @list: list to dequeue from
2411 * Remove the tail of the list. This function does not take any locks
2412 * so must be used with appropriate locks held only. The tail item is
2413 * returned or %NULL if the list is empty.
2415 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2417 struct sk_buff *skb = skb_peek_tail(list);
2419 __skb_unlink(skb, list);
2422 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2425 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2427 return skb->data_len;
2430 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2432 return skb->len - skb->data_len;
2435 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2437 unsigned int i, len = 0;
2439 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2440 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2444 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2446 return skb_headlen(skb) + __skb_pagelen(skb);
2449 static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag,
2450 netmem_ref netmem, int off,
2453 frag->netmem = netmem;
2455 skb_frag_size_set(frag, size);
2458 static inline void skb_frag_fill_page_desc(skb_frag_t *frag,
2462 skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size);
2465 static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo,
2466 int i, netmem_ref netmem,
2469 skb_frag_t *frag = &shinfo->frags[i];
2471 skb_frag_fill_netmem_desc(frag, netmem, off, size);
2474 static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2475 int i, struct page *page,
2478 __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off,
2483 * skb_len_add - adds a number to len fields of skb
2484 * @skb: buffer to add len to
2485 * @delta: number of bytes to add
2487 static inline void skb_len_add(struct sk_buff *skb, int delta)
2490 skb->data_len += delta;
2491 skb->truesize += delta;
2495 * __skb_fill_netmem_desc - initialise a fragment in an skb
2496 * @skb: buffer containing fragment to be initialised
2497 * @i: fragment index to initialise
2498 * @netmem: the netmem to use for this fragment
2499 * @off: the offset to the data with @page
2500 * @size: the length of the data
2502 * Initialises the @i'th fragment of @skb to point to &size bytes at
2503 * offset @off within @page.
2505 * Does not take any additional reference on the fragment.
2507 static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i,
2508 netmem_ref netmem, int off, int size)
2510 struct page *page = netmem_to_page(netmem);
2512 __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size);
2514 /* Propagate page pfmemalloc to the skb if we can. The problem is
2515 * that not all callers have unique ownership of the page but rely
2516 * on page_is_pfmemalloc doing the right thing(tm).
2518 page = compound_head(page);
2519 if (page_is_pfmemalloc(page))
2520 skb->pfmemalloc = true;
2523 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2524 struct page *page, int off, int size)
2526 __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2529 static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i,
2530 netmem_ref netmem, int off, int size)
2532 __skb_fill_netmem_desc(skb, i, netmem, off, size);
2533 skb_shinfo(skb)->nr_frags = i + 1;
2537 * skb_fill_page_desc - initialise a paged fragment in an skb
2538 * @skb: buffer containing fragment to be initialised
2539 * @i: paged fragment index to initialise
2540 * @page: the page to use for this fragment
2541 * @off: the offset to the data with @page
2542 * @size: the length of the data
2544 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2545 * @skb to point to @size bytes at offset @off within @page. In
2546 * addition updates @skb such that @i is the last fragment.
2548 * Does not take any additional reference on the fragment.
2550 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2551 struct page *page, int off, int size)
2553 skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2557 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb
2558 * @skb: buffer containing fragment to be initialised
2559 * @i: paged fragment index to initialise
2560 * @page: the page to use for this fragment
2561 * @off: the offset to the data with @page
2562 * @size: the length of the data
2564 * Variant of skb_fill_page_desc() which does not deal with
2565 * pfmemalloc, if page is not owned by us.
2567 static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i,
2568 struct page *page, int off,
2571 struct skb_shared_info *shinfo = skb_shinfo(skb);
2573 __skb_fill_page_desc_noacc(shinfo, i, page, off, size);
2574 shinfo->nr_frags = i + 1;
2577 void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem,
2578 int off, int size, unsigned int truesize);
2580 static inline void skb_add_rx_frag(struct sk_buff *skb, int i,
2581 struct page *page, int off, int size,
2582 unsigned int truesize)
2584 skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size,
2588 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2589 unsigned int truesize);
2591 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2593 #ifdef NET_SKBUFF_DATA_USES_OFFSET
2594 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2596 return skb->head + skb->tail;
2599 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2601 skb->tail = skb->data - skb->head;
2604 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2606 skb_reset_tail_pointer(skb);
2607 skb->tail += offset;
2610 #else /* NET_SKBUFF_DATA_USES_OFFSET */
2611 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2616 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2618 skb->tail = skb->data;
2621 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2623 skb->tail = skb->data + offset;
2626 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2628 static inline void skb_assert_len(struct sk_buff *skb)
2630 #ifdef CONFIG_DEBUG_NET
2631 if (WARN_ONCE(!skb->len, "%s\n", __func__))
2632 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2633 #endif /* CONFIG_DEBUG_NET */
2637 * Add data to an sk_buff
2639 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2640 void *skb_put(struct sk_buff *skb, unsigned int len);
2641 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2643 void *tmp = skb_tail_pointer(skb);
2644 SKB_LINEAR_ASSERT(skb);
2650 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2652 void *tmp = __skb_put(skb, len);
2654 memset(tmp, 0, len);
2658 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2661 void *tmp = __skb_put(skb, len);
2663 memcpy(tmp, data, len);
2667 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2669 *(u8 *)__skb_put(skb, 1) = val;
2672 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2674 void *tmp = skb_put(skb, len);
2676 memset(tmp, 0, len);
2681 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2684 void *tmp = skb_put(skb, len);
2686 memcpy(tmp, data, len);
2691 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2693 *(u8 *)skb_put(skb, 1) = val;
2696 void *skb_push(struct sk_buff *skb, unsigned int len);
2697 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2699 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2706 void *skb_pull(struct sk_buff *skb, unsigned int len);
2707 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2709 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2712 if (unlikely(skb->len < skb->data_len)) {
2713 #if defined(CONFIG_DEBUG_NET)
2715 pr_err("__skb_pull(len=%u)\n", len);
2716 skb_dump(KERN_ERR, skb, false);
2720 return skb->data += len;
2723 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2725 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2728 void *skb_pull_data(struct sk_buff *skb, size_t len);
2730 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2732 static inline enum skb_drop_reason
2733 pskb_may_pull_reason(struct sk_buff *skb, unsigned int len)
2735 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2737 if (likely(len <= skb_headlen(skb)))
2738 return SKB_NOT_DROPPED_YET;
2740 if (unlikely(len > skb->len))
2741 return SKB_DROP_REASON_PKT_TOO_SMALL;
2743 if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb))))
2744 return SKB_DROP_REASON_NOMEM;
2746 return SKB_NOT_DROPPED_YET;
2749 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2751 return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET;
2754 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2756 if (!pskb_may_pull(skb, len))
2760 return skb->data += len;
2763 void skb_condense(struct sk_buff *skb);
2766 * skb_headroom - bytes at buffer head
2767 * @skb: buffer to check
2769 * Return the number of bytes of free space at the head of an &sk_buff.
2771 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2773 return skb->data - skb->head;
2777 * skb_tailroom - bytes at buffer end
2778 * @skb: buffer to check
2780 * Return the number of bytes of free space at the tail of an sk_buff
2782 static inline int skb_tailroom(const struct sk_buff *skb)
2784 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2788 * skb_availroom - bytes at buffer end
2789 * @skb: buffer to check
2791 * Return the number of bytes of free space at the tail of an sk_buff
2792 * allocated by sk_stream_alloc()
2794 static inline int skb_availroom(const struct sk_buff *skb)
2796 if (skb_is_nonlinear(skb))
2799 return skb->end - skb->tail - skb->reserved_tailroom;
2803 * skb_reserve - adjust headroom
2804 * @skb: buffer to alter
2805 * @len: bytes to move
2807 * Increase the headroom of an empty &sk_buff by reducing the tail
2808 * room. This is only allowed for an empty buffer.
2810 static inline void skb_reserve(struct sk_buff *skb, int len)
2817 * skb_tailroom_reserve - adjust reserved_tailroom
2818 * @skb: buffer to alter
2819 * @mtu: maximum amount of headlen permitted
2820 * @needed_tailroom: minimum amount of reserved_tailroom
2822 * Set reserved_tailroom so that headlen can be as large as possible but
2823 * not larger than mtu and tailroom cannot be smaller than
2825 * The required headroom should already have been reserved before using
2828 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2829 unsigned int needed_tailroom)
2831 SKB_LINEAR_ASSERT(skb);
2832 if (mtu < skb_tailroom(skb) - needed_tailroom)
2833 /* use at most mtu */
2834 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2836 /* use up to all available space */
2837 skb->reserved_tailroom = needed_tailroom;
2840 #define ENCAP_TYPE_ETHER 0
2841 #define ENCAP_TYPE_IPPROTO 1
2843 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2846 skb->inner_protocol = protocol;
2847 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2850 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2853 skb->inner_ipproto = ipproto;
2854 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2857 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2859 skb->inner_mac_header = skb->mac_header;
2860 skb->inner_network_header = skb->network_header;
2861 skb->inner_transport_header = skb->transport_header;
2864 static inline void skb_reset_mac_len(struct sk_buff *skb)
2866 skb->mac_len = skb->network_header - skb->mac_header;
2869 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2872 return skb->head + skb->inner_transport_header;
2875 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2877 return skb_inner_transport_header(skb) - skb->data;
2880 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2882 skb->inner_transport_header = skb->data - skb->head;
2885 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2888 skb_reset_inner_transport_header(skb);
2889 skb->inner_transport_header += offset;
2892 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2894 return skb->head + skb->inner_network_header;
2897 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2899 skb->inner_network_header = skb->data - skb->head;
2902 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2905 skb_reset_inner_network_header(skb);
2906 skb->inner_network_header += offset;
2909 static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb)
2911 return skb->inner_network_header > 0;
2914 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2916 return skb->head + skb->inner_mac_header;
2919 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2921 skb->inner_mac_header = skb->data - skb->head;
2924 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2927 skb_reset_inner_mac_header(skb);
2928 skb->inner_mac_header += offset;
2930 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2932 return skb->transport_header != (typeof(skb->transport_header))~0U;
2935 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2937 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
2938 return skb->head + skb->transport_header;
2941 static inline void skb_reset_transport_header(struct sk_buff *skb)
2943 skb->transport_header = skb->data - skb->head;
2946 static inline void skb_set_transport_header(struct sk_buff *skb,
2949 skb_reset_transport_header(skb);
2950 skb->transport_header += offset;
2953 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2955 return skb->head + skb->network_header;
2958 static inline void skb_reset_network_header(struct sk_buff *skb)
2960 skb->network_header = skb->data - skb->head;
2963 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2965 skb_reset_network_header(skb);
2966 skb->network_header += offset;
2969 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2971 return skb->mac_header != (typeof(skb->mac_header))~0U;
2974 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2976 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2977 return skb->head + skb->mac_header;
2980 static inline int skb_mac_offset(const struct sk_buff *skb)
2982 return skb_mac_header(skb) - skb->data;
2985 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2987 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2988 return skb->network_header - skb->mac_header;
2991 static inline void skb_unset_mac_header(struct sk_buff *skb)
2993 skb->mac_header = (typeof(skb->mac_header))~0U;
2996 static inline void skb_reset_mac_header(struct sk_buff *skb)
2998 skb->mac_header = skb->data - skb->head;
3001 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
3003 skb_reset_mac_header(skb);
3004 skb->mac_header += offset;
3007 static inline void skb_pop_mac_header(struct sk_buff *skb)
3009 skb->mac_header = skb->network_header;
3012 static inline void skb_probe_transport_header(struct sk_buff *skb)
3014 struct flow_keys_basic keys;
3016 if (skb_transport_header_was_set(skb))
3019 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
3021 skb_set_transport_header(skb, keys.control.thoff);
3024 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
3026 if (skb_mac_header_was_set(skb)) {
3027 const unsigned char *old_mac = skb_mac_header(skb);
3029 skb_set_mac_header(skb, -skb->mac_len);
3030 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
3034 /* Move the full mac header up to current network_header.
3035 * Leaves skb->data pointing at offset skb->mac_len into the mac_header.
3036 * Must be provided the complete mac header length.
3038 static inline void skb_mac_header_rebuild_full(struct sk_buff *skb, u32 full_mac_len)
3040 if (skb_mac_header_was_set(skb)) {
3041 const unsigned char *old_mac = skb_mac_header(skb);
3043 skb_set_mac_header(skb, -full_mac_len);
3044 memmove(skb_mac_header(skb), old_mac, full_mac_len);
3045 __skb_push(skb, full_mac_len - skb->mac_len);
3049 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
3051 return skb->csum_start - skb_headroom(skb);
3054 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
3056 return skb->head + skb->csum_start;
3059 static inline int skb_transport_offset(const struct sk_buff *skb)
3061 return skb_transport_header(skb) - skb->data;
3064 static inline u32 skb_network_header_len(const struct sk_buff *skb)
3066 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
3067 return skb->transport_header - skb->network_header;
3070 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
3072 return skb->inner_transport_header - skb->inner_network_header;
3075 static inline int skb_network_offset(const struct sk_buff *skb)
3077 return skb_network_header(skb) - skb->data;
3080 static inline int skb_inner_network_offset(const struct sk_buff *skb)
3082 return skb_inner_network_header(skb) - skb->data;
3085 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
3087 return pskb_may_pull(skb, skb_network_offset(skb) + len);
3091 * CPUs often take a performance hit when accessing unaligned memory
3092 * locations. The actual performance hit varies, it can be small if the
3093 * hardware handles it or large if we have to take an exception and fix it
3096 * Since an ethernet header is 14 bytes network drivers often end up with
3097 * the IP header at an unaligned offset. The IP header can be aligned by
3098 * shifting the start of the packet by 2 bytes. Drivers should do this
3101 * skb_reserve(skb, NET_IP_ALIGN);
3103 * The downside to this alignment of the IP header is that the DMA is now
3104 * unaligned. On some architectures the cost of an unaligned DMA is high
3105 * and this cost outweighs the gains made by aligning the IP header.
3107 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
3110 #ifndef NET_IP_ALIGN
3111 #define NET_IP_ALIGN 2
3115 * The networking layer reserves some headroom in skb data (via
3116 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
3117 * the header has to grow. In the default case, if the header has to grow
3118 * 32 bytes or less we avoid the reallocation.
3120 * Unfortunately this headroom changes the DMA alignment of the resulting
3121 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
3122 * on some architectures. An architecture can override this value,
3123 * perhaps setting it to a cacheline in size (since that will maintain
3124 * cacheline alignment of the DMA). It must be a power of 2.
3126 * Various parts of the networking layer expect at least 32 bytes of
3127 * headroom, you should not reduce this.
3129 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
3130 * to reduce average number of cache lines per packet.
3131 * get_rps_cpu() for example only access one 64 bytes aligned block :
3132 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
3135 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
3138 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
3140 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
3142 if (WARN_ON(skb_is_nonlinear(skb)))
3145 skb_set_tail_pointer(skb, len);
3148 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
3150 __skb_set_length(skb, len);
3153 void skb_trim(struct sk_buff *skb, unsigned int len);
3155 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
3158 return ___pskb_trim(skb, len);
3159 __skb_trim(skb, len);
3163 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
3165 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
3169 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
3170 * @skb: buffer to alter
3173 * This is identical to pskb_trim except that the caller knows that
3174 * the skb is not cloned so we should never get an error due to out-
3177 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
3179 int err = pskb_trim(skb, len);
3183 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
3185 unsigned int diff = len - skb->len;
3187 if (skb_tailroom(skb) < diff) {
3188 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
3193 __skb_set_length(skb, len);
3198 * skb_orphan - orphan a buffer
3199 * @skb: buffer to orphan
3201 * If a buffer currently has an owner then we call the owner's
3202 * destructor function and make the @skb unowned. The buffer continues
3203 * to exist but is no longer charged to its former owner.
3205 static inline void skb_orphan(struct sk_buff *skb)
3207 if (skb->destructor) {
3208 skb->destructor(skb);
3209 skb->destructor = NULL;
3217 * skb_orphan_frags - orphan the frags contained in a buffer
3218 * @skb: buffer to orphan frags from
3219 * @gfp_mask: allocation mask for replacement pages
3221 * For each frag in the SKB which needs a destructor (i.e. has an
3222 * owner) create a copy of that frag and release the original
3223 * page by calling the destructor.
3225 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3227 if (likely(!skb_zcopy(skb)))
3229 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3231 return skb_copy_ubufs(skb, gfp_mask);
3234 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
3235 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3237 if (likely(!skb_zcopy(skb)))
3239 return skb_copy_ubufs(skb, gfp_mask);
3243 * __skb_queue_purge_reason - empty a list
3244 * @list: list to empty
3245 * @reason: drop reason
3247 * Delete all buffers on an &sk_buff list. Each buffer is removed from
3248 * the list and one reference dropped. This function does not take the
3249 * list lock and the caller must hold the relevant locks to use it.
3251 static inline void __skb_queue_purge_reason(struct sk_buff_head *list,
3252 enum skb_drop_reason reason)
3254 struct sk_buff *skb;
3256 while ((skb = __skb_dequeue(list)) != NULL)
3257 kfree_skb_reason(skb, reason);
3260 static inline void __skb_queue_purge(struct sk_buff_head *list)
3262 __skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3265 void skb_queue_purge_reason(struct sk_buff_head *list,
3266 enum skb_drop_reason reason);
3268 static inline void skb_queue_purge(struct sk_buff_head *list)
3270 skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3273 unsigned int skb_rbtree_purge(struct rb_root *root);
3274 void skb_errqueue_purge(struct sk_buff_head *list);
3276 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3279 * netdev_alloc_frag - allocate a page fragment
3280 * @fragsz: fragment size
3282 * Allocates a frag from a page for receive buffer.
3283 * Uses GFP_ATOMIC allocations.
3285 static inline void *netdev_alloc_frag(unsigned int fragsz)
3287 return __netdev_alloc_frag_align(fragsz, ~0u);
3290 static inline void *netdev_alloc_frag_align(unsigned int fragsz,
3293 WARN_ON_ONCE(!is_power_of_2(align));
3294 return __netdev_alloc_frag_align(fragsz, -align);
3297 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
3301 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
3302 * @dev: network device to receive on
3303 * @length: length to allocate
3305 * Allocate a new &sk_buff and assign it a usage count of one. The
3306 * buffer has unspecified headroom built in. Users should allocate
3307 * the headroom they think they need without accounting for the
3308 * built in space. The built in space is used for optimisations.
3310 * %NULL is returned if there is no free memory. Although this function
3311 * allocates memory it can be called from an interrupt.
3313 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
3314 unsigned int length)
3316 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3319 /* legacy helper around __netdev_alloc_skb() */
3320 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
3323 return __netdev_alloc_skb(NULL, length, gfp_mask);
3326 /* legacy helper around netdev_alloc_skb() */
3327 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
3329 return netdev_alloc_skb(NULL, length);
3333 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
3334 unsigned int length, gfp_t gfp)
3336 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
3338 if (NET_IP_ALIGN && skb)
3339 skb_reserve(skb, NET_IP_ALIGN);
3343 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
3344 unsigned int length)
3346 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3349 static inline void skb_free_frag(void *addr)
3351 page_frag_free(addr);
3354 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3356 static inline void *napi_alloc_frag(unsigned int fragsz)
3358 return __napi_alloc_frag_align(fragsz, ~0u);
3361 static inline void *napi_alloc_frag_align(unsigned int fragsz,
3364 WARN_ON_ONCE(!is_power_of_2(align));
3365 return __napi_alloc_frag_align(fragsz, -align);
3368 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
3369 unsigned int length, gfp_t gfp_mask);
3370 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
3371 unsigned int length)
3373 return __napi_alloc_skb(napi, length, GFP_ATOMIC);
3375 void napi_consume_skb(struct sk_buff *skb, int budget);
3377 void napi_skb_free_stolen_head(struct sk_buff *skb);
3378 void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason);
3381 * __dev_alloc_pages - allocate page for network Rx
3382 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3383 * @order: size of the allocation
3385 * Allocate a new page.
3387 * %NULL is returned if there is no free memory.
3389 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
3392 /* This piece of code contains several assumptions.
3393 * 1. This is for device Rx, therefore a cold page is preferred.
3394 * 2. The expectation is the user wants a compound page.
3395 * 3. If requesting a order 0 page it will not be compound
3396 * due to the check to see if order has a value in prep_new_page
3397 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3398 * code in gfp_to_alloc_flags that should be enforcing this.
3400 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
3402 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
3405 static inline struct page *dev_alloc_pages(unsigned int order)
3407 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order);
3411 * __dev_alloc_page - allocate a page for network Rx
3412 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3414 * Allocate a new page.
3416 * %NULL is returned if there is no free memory.
3418 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
3420 return __dev_alloc_pages(gfp_mask, 0);
3423 static inline struct page *dev_alloc_page(void)
3425 return dev_alloc_pages(0);
3429 * dev_page_is_reusable - check whether a page can be reused for network Rx
3430 * @page: the page to test
3432 * A page shouldn't be considered for reusing/recycling if it was allocated
3433 * under memory pressure or at a distant memory node.
3435 * Returns false if this page should be returned to page allocator, true
3438 static inline bool dev_page_is_reusable(const struct page *page)
3440 return likely(page_to_nid(page) == numa_mem_id() &&
3441 !page_is_pfmemalloc(page));
3445 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3446 * @page: The page that was allocated from skb_alloc_page
3447 * @skb: The skb that may need pfmemalloc set
3449 static inline void skb_propagate_pfmemalloc(const struct page *page,
3450 struct sk_buff *skb)
3452 if (page_is_pfmemalloc(page))
3453 skb->pfmemalloc = true;
3457 * skb_frag_off() - Returns the offset of a skb fragment
3458 * @frag: the paged fragment
3460 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3462 return frag->offset;
3466 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3467 * @frag: skb fragment
3468 * @delta: value to add
3470 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3472 frag->offset += delta;
3476 * skb_frag_off_set() - Sets the offset of a skb fragment
3477 * @frag: skb fragment
3478 * @offset: offset of fragment
3480 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3482 frag->offset = offset;
3486 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3487 * @fragto: skb fragment where offset is set
3488 * @fragfrom: skb fragment offset is copied from
3490 static inline void skb_frag_off_copy(skb_frag_t *fragto,
3491 const skb_frag_t *fragfrom)
3493 fragto->offset = fragfrom->offset;
3497 * skb_frag_page - retrieve the page referred to by a paged fragment
3498 * @frag: the paged fragment
3500 * Returns the &struct page associated with @frag.
3502 static inline struct page *skb_frag_page(const skb_frag_t *frag)
3504 return netmem_to_page(frag->netmem);
3508 * __skb_frag_ref - take an addition reference on a paged fragment.
3509 * @frag: the paged fragment
3511 * Takes an additional reference on the paged fragment @frag.
3513 static inline void __skb_frag_ref(skb_frag_t *frag)
3515 get_page(skb_frag_page(frag));
3519 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
3521 * @f: the fragment offset.
3523 * Takes an additional reference on the @f'th paged fragment of @skb.
3525 static inline void skb_frag_ref(struct sk_buff *skb, int f)
3527 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3530 int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
3531 unsigned int headroom);
3532 int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
3533 struct bpf_prog *prog);
3534 bool napi_pp_put_page(struct page *page, bool napi_safe);
3537 skb_page_unref(const struct sk_buff *skb, struct page *page, bool napi_safe)
3539 #ifdef CONFIG_PAGE_POOL
3540 if (skb->pp_recycle && napi_pp_put_page(page, napi_safe))
3547 napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
3549 struct page *page = skb_frag_page(frag);
3551 #ifdef CONFIG_PAGE_POOL
3552 if (recycle && napi_pp_put_page(page, napi_safe))
3559 * __skb_frag_unref - release a reference on a paged fragment.
3560 * @frag: the paged fragment
3561 * @recycle: recycle the page if allocated via page_pool
3563 * Releases a reference on the paged fragment @frag
3564 * or recycles the page via the page_pool API.
3566 static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
3568 napi_frag_unref(frag, recycle, false);
3572 * skb_frag_unref - release a reference on a paged fragment of an skb.
3574 * @f: the fragment offset
3576 * Releases a reference on the @f'th paged fragment of @skb.
3578 static inline void skb_frag_unref(struct sk_buff *skb, int f)
3580 struct skb_shared_info *shinfo = skb_shinfo(skb);
3582 if (!skb_zcopy_managed(skb))
3583 __skb_frag_unref(&shinfo->frags[f], skb->pp_recycle);
3587 * skb_frag_address - gets the address of the data contained in a paged fragment
3588 * @frag: the paged fragment buffer
3590 * Returns the address of the data within @frag. The page must already
3593 static inline void *skb_frag_address(const skb_frag_t *frag)
3595 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3599 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3600 * @frag: the paged fragment buffer
3602 * Returns the address of the data within @frag. Checks that the page
3603 * is mapped and returns %NULL otherwise.
3605 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3607 void *ptr = page_address(skb_frag_page(frag));
3611 return ptr + skb_frag_off(frag);
3615 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3616 * @fragto: skb fragment where page is set
3617 * @fragfrom: skb fragment page is copied from
3619 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3620 const skb_frag_t *fragfrom)
3622 fragto->netmem = fragfrom->netmem;
3625 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3628 * skb_frag_dma_map - maps a paged fragment via the DMA API
3629 * @dev: the device to map the fragment to
3630 * @frag: the paged fragment to map
3631 * @offset: the offset within the fragment (starting at the
3632 * fragment's own offset)
3633 * @size: the number of bytes to map
3634 * @dir: the direction of the mapping (``PCI_DMA_*``)
3636 * Maps the page associated with @frag to @device.
3638 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3639 const skb_frag_t *frag,
3640 size_t offset, size_t size,
3641 enum dma_data_direction dir)
3643 return dma_map_page(dev, skb_frag_page(frag),
3644 skb_frag_off(frag) + offset, size, dir);
3647 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3650 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3654 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3657 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3662 * skb_clone_writable - is the header of a clone writable
3663 * @skb: buffer to check
3664 * @len: length up to which to write
3666 * Returns true if modifying the header part of the cloned buffer
3667 * does not requires the data to be copied.
3669 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3671 return !skb_header_cloned(skb) &&
3672 skb_headroom(skb) + len <= skb->hdr_len;
3675 static inline int skb_try_make_writable(struct sk_buff *skb,
3676 unsigned int write_len)
3678 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3679 pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3682 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3687 if (headroom > skb_headroom(skb))
3688 delta = headroom - skb_headroom(skb);
3690 if (delta || cloned)
3691 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3697 * skb_cow - copy header of skb when it is required
3698 * @skb: buffer to cow
3699 * @headroom: needed headroom
3701 * If the skb passed lacks sufficient headroom or its data part
3702 * is shared, data is reallocated. If reallocation fails, an error
3703 * is returned and original skb is not changed.
3705 * The result is skb with writable area skb->head...skb->tail
3706 * and at least @headroom of space at head.
3708 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3710 return __skb_cow(skb, headroom, skb_cloned(skb));
3714 * skb_cow_head - skb_cow but only making the head writable
3715 * @skb: buffer to cow
3716 * @headroom: needed headroom
3718 * This function is identical to skb_cow except that we replace the
3719 * skb_cloned check by skb_header_cloned. It should be used when
3720 * you only need to push on some header and do not need to modify
3723 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3725 return __skb_cow(skb, headroom, skb_header_cloned(skb));
3729 * skb_padto - pad an skbuff up to a minimal size
3730 * @skb: buffer to pad
3731 * @len: minimal length
3733 * Pads up a buffer to ensure the trailing bytes exist and are
3734 * blanked. If the buffer already contains sufficient data it
3735 * is untouched. Otherwise it is extended. Returns zero on
3736 * success. The skb is freed on error.
3738 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3740 unsigned int size = skb->len;
3741 if (likely(size >= len))
3743 return skb_pad(skb, len - size);
3747 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3748 * @skb: buffer to pad
3749 * @len: minimal length
3750 * @free_on_error: free buffer on error
3752 * Pads up a buffer to ensure the trailing bytes exist and are
3753 * blanked. If the buffer already contains sufficient data it
3754 * is untouched. Otherwise it is extended. Returns zero on
3755 * success. The skb is freed on error if @free_on_error is true.
3757 static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3761 unsigned int size = skb->len;
3763 if (unlikely(size < len)) {
3765 if (__skb_pad(skb, len, free_on_error))
3767 __skb_put(skb, len);
3773 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3774 * @skb: buffer to pad
3775 * @len: minimal length
3777 * Pads up a buffer to ensure the trailing bytes exist and are
3778 * blanked. If the buffer already contains sufficient data it
3779 * is untouched. Otherwise it is extended. Returns zero on
3780 * success. The skb is freed on error.
3782 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3784 return __skb_put_padto(skb, len, true);
3787 bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i)
3790 static inline int skb_add_data(struct sk_buff *skb,
3791 struct iov_iter *from, int copy)
3793 const int off = skb->len;
3795 if (skb->ip_summed == CHECKSUM_NONE) {
3797 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3799 skb->csum = csum_block_add(skb->csum, csum, off);
3802 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3805 __skb_trim(skb, off);
3809 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3810 const struct page *page, int off)
3815 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3817 return page == skb_frag_page(frag) &&
3818 off == skb_frag_off(frag) + skb_frag_size(frag);
3823 static inline int __skb_linearize(struct sk_buff *skb)
3825 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3829 * skb_linearize - convert paged skb to linear one
3830 * @skb: buffer to linarize
3832 * If there is no free memory -ENOMEM is returned, otherwise zero
3833 * is returned and the old skb data released.
3835 static inline int skb_linearize(struct sk_buff *skb)
3837 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3841 * skb_has_shared_frag - can any frag be overwritten
3842 * @skb: buffer to test
3844 * Return true if the skb has at least one frag that might be modified
3845 * by an external entity (as in vmsplice()/sendfile())
3847 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3849 return skb_is_nonlinear(skb) &&
3850 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3854 * skb_linearize_cow - make sure skb is linear and writable
3855 * @skb: buffer to process
3857 * If there is no free memory -ENOMEM is returned, otherwise zero
3858 * is returned and the old skb data released.
3860 static inline int skb_linearize_cow(struct sk_buff *skb)
3862 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3863 __skb_linearize(skb) : 0;
3866 static __always_inline void
3867 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3870 if (skb->ip_summed == CHECKSUM_COMPLETE)
3871 skb->csum = csum_block_sub(skb->csum,
3872 csum_partial(start, len, 0), off);
3873 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3874 skb_checksum_start_offset(skb) < 0)
3875 skb->ip_summed = CHECKSUM_NONE;
3879 * skb_postpull_rcsum - update checksum for received skb after pull
3880 * @skb: buffer to update
3881 * @start: start of data before pull
3882 * @len: length of data pulled
3884 * After doing a pull on a received packet, you need to call this to
3885 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3886 * CHECKSUM_NONE so that it can be recomputed from scratch.
3888 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3889 const void *start, unsigned int len)
3891 if (skb->ip_summed == CHECKSUM_COMPLETE)
3892 skb->csum = wsum_negate(csum_partial(start, len,
3893 wsum_negate(skb->csum)));
3894 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3895 skb_checksum_start_offset(skb) < 0)
3896 skb->ip_summed = CHECKSUM_NONE;
3899 static __always_inline void
3900 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3903 if (skb->ip_summed == CHECKSUM_COMPLETE)
3904 skb->csum = csum_block_add(skb->csum,
3905 csum_partial(start, len, 0), off);
3909 * skb_postpush_rcsum - update checksum for received skb after push
3910 * @skb: buffer to update
3911 * @start: start of data after push
3912 * @len: length of data pushed
3914 * After doing a push on a received packet, you need to call this to
3915 * update the CHECKSUM_COMPLETE checksum.
3917 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3918 const void *start, unsigned int len)
3920 __skb_postpush_rcsum(skb, start, len, 0);
3923 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3926 * skb_push_rcsum - push skb and update receive checksum
3927 * @skb: buffer to update
3928 * @len: length of data pulled
3930 * This function performs an skb_push on the packet and updates
3931 * the CHECKSUM_COMPLETE checksum. It should be used on
3932 * receive path processing instead of skb_push unless you know
3933 * that the checksum difference is zero (e.g., a valid IP header)
3934 * or you are setting ip_summed to CHECKSUM_NONE.
3936 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3939 skb_postpush_rcsum(skb, skb->data, len);
3943 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3945 * pskb_trim_rcsum - trim received skb and update checksum
3946 * @skb: buffer to trim
3949 * This is exactly the same as pskb_trim except that it ensures the
3950 * checksum of received packets are still valid after the operation.
3951 * It can change skb pointers.
3954 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3956 if (likely(len >= skb->len))
3958 return pskb_trim_rcsum_slow(skb, len);
3961 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3963 if (skb->ip_summed == CHECKSUM_COMPLETE)
3964 skb->ip_summed = CHECKSUM_NONE;
3965 __skb_trim(skb, len);
3969 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3971 if (skb->ip_summed == CHECKSUM_COMPLETE)
3972 skb->ip_summed = CHECKSUM_NONE;
3973 return __skb_grow(skb, len);
3976 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3977 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3978 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3979 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3980 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3982 #define skb_queue_walk(queue, skb) \
3983 for (skb = (queue)->next; \
3984 skb != (struct sk_buff *)(queue); \
3987 #define skb_queue_walk_safe(queue, skb, tmp) \
3988 for (skb = (queue)->next, tmp = skb->next; \
3989 skb != (struct sk_buff *)(queue); \
3990 skb = tmp, tmp = skb->next)
3992 #define skb_queue_walk_from(queue, skb) \
3993 for (; skb != (struct sk_buff *)(queue); \
3996 #define skb_rbtree_walk(skb, root) \
3997 for (skb = skb_rb_first(root); skb != NULL; \
3998 skb = skb_rb_next(skb))
4000 #define skb_rbtree_walk_from(skb) \
4001 for (; skb != NULL; \
4002 skb = skb_rb_next(skb))
4004 #define skb_rbtree_walk_from_safe(skb, tmp) \
4005 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
4008 #define skb_queue_walk_from_safe(queue, skb, tmp) \
4009 for (tmp = skb->next; \
4010 skb != (struct sk_buff *)(queue); \
4011 skb = tmp, tmp = skb->next)
4013 #define skb_queue_reverse_walk(queue, skb) \
4014 for (skb = (queue)->prev; \
4015 skb != (struct sk_buff *)(queue); \
4018 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
4019 for (skb = (queue)->prev, tmp = skb->prev; \
4020 skb != (struct sk_buff *)(queue); \
4021 skb = tmp, tmp = skb->prev)
4023 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
4024 for (tmp = skb->prev; \
4025 skb != (struct sk_buff *)(queue); \
4026 skb = tmp, tmp = skb->prev)
4028 static inline bool skb_has_frag_list(const struct sk_buff *skb)
4030 return skb_shinfo(skb)->frag_list != NULL;
4033 static inline void skb_frag_list_init(struct sk_buff *skb)
4035 skb_shinfo(skb)->frag_list = NULL;
4038 #define skb_walk_frags(skb, iter) \
4039 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
4042 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
4043 int *err, long *timeo_p,
4044 const struct sk_buff *skb);
4045 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
4046 struct sk_buff_head *queue,
4049 struct sk_buff **last);
4050 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
4051 struct sk_buff_head *queue,
4052 unsigned int flags, int *off, int *err,
4053 struct sk_buff **last);
4054 struct sk_buff *__skb_recv_datagram(struct sock *sk,
4055 struct sk_buff_head *sk_queue,
4056 unsigned int flags, int *off, int *err);
4057 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
4058 __poll_t datagram_poll(struct file *file, struct socket *sock,
4059 struct poll_table_struct *wait);
4060 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
4061 struct iov_iter *to, int size);
4062 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
4063 struct msghdr *msg, int size)
4065 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
4067 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
4068 struct msghdr *msg);
4069 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
4070 struct iov_iter *to, int len,
4071 struct ahash_request *hash);
4072 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
4073 struct iov_iter *from, int len);
4074 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
4075 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
4076 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
4077 static inline void skb_free_datagram_locked(struct sock *sk,
4078 struct sk_buff *skb)
4080 __skb_free_datagram_locked(sk, skb, 0);
4082 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
4083 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
4084 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
4085 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
4087 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
4088 struct pipe_inode_info *pipe, unsigned int len,
4089 unsigned int flags);
4090 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
4092 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
4093 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
4094 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
4095 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
4097 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
4098 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
4099 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
4100 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
4101 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
4102 unsigned int offset);
4103 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
4104 int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
4105 int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev);
4106 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
4107 int skb_vlan_pop(struct sk_buff *skb);
4108 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
4109 int skb_eth_pop(struct sk_buff *skb);
4110 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
4111 const unsigned char *src);
4112 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
4113 int mac_len, bool ethernet);
4114 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
4116 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
4117 int skb_mpls_dec_ttl(struct sk_buff *skb);
4118 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
4121 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
4123 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
4126 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
4128 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
4131 struct skb_checksum_ops {
4132 __wsum (*update)(const void *mem, int len, __wsum wsum);
4133 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
4136 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
4138 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
4139 __wsum csum, const struct skb_checksum_ops *ops);
4140 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
4143 static inline void * __must_check
4144 __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
4145 const void *data, int hlen, void *buffer)
4147 if (likely(hlen - offset >= len))
4148 return (void *)data + offset;
4150 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
4156 static inline void * __must_check
4157 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
4159 return __skb_header_pointer(skb, offset, len, skb->data,
4160 skb_headlen(skb), buffer);
4163 static inline void * __must_check
4164 skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len)
4166 if (likely(skb_headlen(skb) - offset >= len))
4167 return skb->data + offset;
4172 * skb_needs_linearize - check if we need to linearize a given skb
4173 * depending on the given device features.
4174 * @skb: socket buffer to check
4175 * @features: net device features
4177 * Returns true if either:
4178 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
4179 * 2. skb is fragmented and the device does not support SG.
4181 static inline bool skb_needs_linearize(struct sk_buff *skb,
4182 netdev_features_t features)
4184 return skb_is_nonlinear(skb) &&
4185 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
4186 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
4189 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
4191 const unsigned int len)
4193 memcpy(to, skb->data, len);
4196 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4197 const int offset, void *to,
4198 const unsigned int len)
4200 memcpy(to, skb->data + offset, len);
4203 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4205 const unsigned int len)
4207 memcpy(skb->data, from, len);
4210 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4213 const unsigned int len)
4215 memcpy(skb->data + offset, from, len);
4218 void skb_init(void);
4220 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4226 * skb_get_timestamp - get timestamp from a skb
4227 * @skb: skb to get stamp from
4228 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
4230 * Timestamps are stored in the skb as offsets to a base timestamp.
4231 * This function converts the offset back to a struct timeval and stores
4234 static inline void skb_get_timestamp(const struct sk_buff *skb,
4235 struct __kernel_old_timeval *stamp)
4237 *stamp = ns_to_kernel_old_timeval(skb->tstamp);
4240 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4241 struct __kernel_sock_timeval *stamp)
4243 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4245 stamp->tv_sec = ts.tv_sec;
4246 stamp->tv_usec = ts.tv_nsec / 1000;
4249 static inline void skb_get_timestampns(const struct sk_buff *skb,
4250 struct __kernel_old_timespec *stamp)
4252 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4254 stamp->tv_sec = ts.tv_sec;
4255 stamp->tv_nsec = ts.tv_nsec;
4258 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4259 struct __kernel_timespec *stamp)
4261 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4263 stamp->tv_sec = ts.tv_sec;
4264 stamp->tv_nsec = ts.tv_nsec;
4267 static inline void __net_timestamp(struct sk_buff *skb)
4269 skb->tstamp = ktime_get_real();
4270 skb->mono_delivery_time = 0;
4273 static inline ktime_t net_timedelta(ktime_t t)
4275 return ktime_sub(ktime_get_real(), t);
4278 static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4282 skb->mono_delivery_time = kt && mono;
4285 DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4287 /* It is used in the ingress path to clear the delivery_time.
4288 * If needed, set the skb->tstamp to the (rcv) timestamp.
4290 static inline void skb_clear_delivery_time(struct sk_buff *skb)
4292 if (skb->mono_delivery_time) {
4293 skb->mono_delivery_time = 0;
4294 if (static_branch_unlikely(&netstamp_needed_key))
4295 skb->tstamp = ktime_get_real();
4301 static inline void skb_clear_tstamp(struct sk_buff *skb)
4303 if (skb->mono_delivery_time)
4309 static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4311 if (skb->mono_delivery_time)
4317 static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4319 if (!skb->mono_delivery_time && skb->tstamp)
4322 if (static_branch_unlikely(&netstamp_needed_key) || cond)
4323 return ktime_get_real();
4328 static inline u8 skb_metadata_len(const struct sk_buff *skb)
4330 return skb_shinfo(skb)->meta_len;
4333 static inline void *skb_metadata_end(const struct sk_buff *skb)
4335 return skb_mac_header(skb);
4338 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4339 const struct sk_buff *skb_b,
4342 const void *a = skb_metadata_end(skb_a);
4343 const void *b = skb_metadata_end(skb_b);
4346 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
4347 BITS_PER_LONG != 64)
4350 /* Using more efficient variant than plain call to memcmp(). */
4352 #define __it(x, op) (x -= sizeof(u##op))
4353 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
4354 case 32: diffs |= __it_diff(a, b, 64);
4356 case 24: diffs |= __it_diff(a, b, 64);
4358 case 16: diffs |= __it_diff(a, b, 64);
4360 case 8: diffs |= __it_diff(a, b, 64);
4362 case 28: diffs |= __it_diff(a, b, 64);
4364 case 20: diffs |= __it_diff(a, b, 64);
4366 case 12: diffs |= __it_diff(a, b, 64);
4368 case 4: diffs |= __it_diff(a, b, 32);
4372 return memcmp(a - meta_len, b - meta_len, meta_len);
4377 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4378 const struct sk_buff *skb_b)
4380 u8 len_a = skb_metadata_len(skb_a);
4381 u8 len_b = skb_metadata_len(skb_b);
4383 if (!(len_a | len_b))
4386 return len_a != len_b ?
4387 true : __skb_metadata_differs(skb_a, skb_b, len_a);
4390 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4392 skb_shinfo(skb)->meta_len = meta_len;
4395 static inline void skb_metadata_clear(struct sk_buff *skb)
4397 skb_metadata_set(skb, 0);
4400 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
4402 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4404 void skb_clone_tx_timestamp(struct sk_buff *skb);
4405 bool skb_defer_rx_timestamp(struct sk_buff *skb);
4407 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4409 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4413 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4418 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4421 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4423 * PHY drivers may accept clones of transmitted packets for
4424 * timestamping via their phy_driver.txtstamp method. These drivers
4425 * must call this function to return the skb back to the stack with a
4428 * @skb: clone of the original outgoing packet
4429 * @hwtstamps: hardware time stamps
4432 void skb_complete_tx_timestamp(struct sk_buff *skb,
4433 struct skb_shared_hwtstamps *hwtstamps);
4435 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
4436 struct skb_shared_hwtstamps *hwtstamps,
4437 struct sock *sk, int tstype);
4440 * skb_tstamp_tx - queue clone of skb with send time stamps
4441 * @orig_skb: the original outgoing packet
4442 * @hwtstamps: hardware time stamps, may be NULL if not available
4444 * If the skb has a socket associated, then this function clones the
4445 * skb (thus sharing the actual data and optional structures), stores
4446 * the optional hardware time stamping information (if non NULL) or
4447 * generates a software time stamp (otherwise), then queues the clone
4448 * to the error queue of the socket. Errors are silently ignored.
4450 void skb_tstamp_tx(struct sk_buff *orig_skb,
4451 struct skb_shared_hwtstamps *hwtstamps);
4454 * skb_tx_timestamp() - Driver hook for transmit timestamping
4456 * Ethernet MAC Drivers should call this function in their hard_xmit()
4457 * function immediately before giving the sk_buff to the MAC hardware.
4459 * Specifically, one should make absolutely sure that this function is
4460 * called before TX completion of this packet can trigger. Otherwise
4461 * the packet could potentially already be freed.
4463 * @skb: A socket buffer.
4465 static inline void skb_tx_timestamp(struct sk_buff *skb)
4467 skb_clone_tx_timestamp(skb);
4468 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
4469 skb_tstamp_tx(skb, NULL);
4473 * skb_complete_wifi_ack - deliver skb with wifi status
4475 * @skb: the original outgoing packet
4476 * @acked: ack status
4479 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4481 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
4482 __sum16 __skb_checksum_complete(struct sk_buff *skb);
4484 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4486 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
4488 (skb->ip_summed == CHECKSUM_PARTIAL &&
4489 skb_checksum_start_offset(skb) >= 0));
4493 * skb_checksum_complete - Calculate checksum of an entire packet
4494 * @skb: packet to process
4496 * This function calculates the checksum over the entire packet plus
4497 * the value of skb->csum. The latter can be used to supply the
4498 * checksum of a pseudo header as used by TCP/UDP. It returns the
4501 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
4502 * this function can be used to verify that checksum on received
4503 * packets. In that case the function should return zero if the
4504 * checksum is correct. In particular, this function will return zero
4505 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4506 * hardware has already verified the correctness of the checksum.
4508 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4510 return skb_csum_unnecessary(skb) ?
4511 0 : __skb_checksum_complete(skb);
4514 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4516 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4517 if (skb->csum_level == 0)
4518 skb->ip_summed = CHECKSUM_NONE;
4524 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4526 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4527 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4529 } else if (skb->ip_summed == CHECKSUM_NONE) {
4530 skb->ip_summed = CHECKSUM_UNNECESSARY;
4531 skb->csum_level = 0;
4535 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4537 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4538 skb->ip_summed = CHECKSUM_NONE;
4539 skb->csum_level = 0;
4543 /* Check if we need to perform checksum complete validation.
4545 * Returns true if checksum complete is needed, false otherwise
4546 * (either checksum is unnecessary or zero checksum is allowed).
4548 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4552 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4553 skb->csum_valid = 1;
4554 __skb_decr_checksum_unnecessary(skb);
4561 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4564 #define CHECKSUM_BREAK 76
4566 /* Unset checksum-complete
4568 * Unset checksum complete can be done when packet is being modified
4569 * (uncompressed for instance) and checksum-complete value is
4572 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4574 if (skb->ip_summed == CHECKSUM_COMPLETE)
4575 skb->ip_summed = CHECKSUM_NONE;
4578 /* Validate (init) checksum based on checksum complete.
4581 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
4582 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4583 * checksum is stored in skb->csum for use in __skb_checksum_complete
4584 * non-zero: value of invalid checksum
4587 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4591 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4592 if (!csum_fold(csum_add(psum, skb->csum))) {
4593 skb->csum_valid = 1;
4600 if (complete || skb->len <= CHECKSUM_BREAK) {
4603 csum = __skb_checksum_complete(skb);
4604 skb->csum_valid = !csum;
4611 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4616 /* Perform checksum validate (init). Note that this is a macro since we only
4617 * want to calculate the pseudo header which is an input function if necessary.
4618 * First we try to validate without any computation (checksum unnecessary) and
4619 * then calculate based on checksum complete calling the function to compute
4623 * 0: checksum is validated or try to in skb_checksum_complete
4624 * non-zero: value of invalid checksum
4626 #define __skb_checksum_validate(skb, proto, complete, \
4627 zero_okay, check, compute_pseudo) \
4629 __sum16 __ret = 0; \
4630 skb->csum_valid = 0; \
4631 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4632 __ret = __skb_checksum_validate_complete(skb, \
4633 complete, compute_pseudo(skb, proto)); \
4637 #define skb_checksum_init(skb, proto, compute_pseudo) \
4638 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4640 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4641 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4643 #define skb_checksum_validate(skb, proto, compute_pseudo) \
4644 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4646 #define skb_checksum_validate_zero_check(skb, proto, check, \
4648 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4650 #define skb_checksum_simple_validate(skb) \
4651 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4653 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4655 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4658 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4660 skb->csum = ~pseudo;
4661 skb->ip_summed = CHECKSUM_COMPLETE;
4664 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4666 if (__skb_checksum_convert_check(skb)) \
4667 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4670 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4671 u16 start, u16 offset)
4673 skb->ip_summed = CHECKSUM_PARTIAL;
4674 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4675 skb->csum_offset = offset - start;
4678 /* Update skbuf and packet to reflect the remote checksum offload operation.
4679 * When called, ptr indicates the starting point for skb->csum when
4680 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4681 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4683 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4684 int start, int offset, bool nopartial)
4689 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4693 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4694 __skb_checksum_complete(skb);
4695 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4698 delta = remcsum_adjust(ptr, skb->csum, start, offset);
4700 /* Adjust skb->csum since we changed the packet */
4701 skb->csum = csum_add(skb->csum, delta);
4704 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4706 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4707 return (void *)(skb->_nfct & NFCT_PTRMASK);
4713 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4715 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4722 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4724 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4725 skb->slow_gro |= !!nfct;
4730 #ifdef CONFIG_SKB_EXTENSIONS
4732 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4738 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4741 #if IS_ENABLED(CONFIG_MPTCP)
4744 #if IS_ENABLED(CONFIG_MCTP_FLOWS)
4747 SKB_EXT_NUM, /* must be last */
4751 * struct skb_ext - sk_buff extensions
4752 * @refcnt: 1 on allocation, deallocated on 0
4753 * @offset: offset to add to @data to obtain extension address
4754 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4755 * @data: start of extension data, variable sized
4757 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4758 * to use 'u8' types while allowing up to 2kb worth of extension data.
4762 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4763 u8 chunks; /* same */
4764 char data[] __aligned(8);
4767 struct skb_ext *__skb_ext_alloc(gfp_t flags);
4768 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4769 struct skb_ext *ext);
4770 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4771 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4772 void __skb_ext_put(struct skb_ext *ext);
4774 static inline void skb_ext_put(struct sk_buff *skb)
4776 if (skb->active_extensions)
4777 __skb_ext_put(skb->extensions);
4780 static inline void __skb_ext_copy(struct sk_buff *dst,
4781 const struct sk_buff *src)
4783 dst->active_extensions = src->active_extensions;
4785 if (src->active_extensions) {
4786 struct skb_ext *ext = src->extensions;
4788 refcount_inc(&ext->refcnt);
4789 dst->extensions = ext;
4793 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4796 __skb_ext_copy(dst, src);
4799 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4801 return !!ext->offset[i];
4804 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4806 return skb->active_extensions & (1 << id);
4809 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4811 if (skb_ext_exist(skb, id))
4812 __skb_ext_del(skb, id);
4815 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4817 if (skb_ext_exist(skb, id)) {
4818 struct skb_ext *ext = skb->extensions;
4820 return (void *)ext + (ext->offset[id] << 3);
4826 static inline void skb_ext_reset(struct sk_buff *skb)
4828 if (unlikely(skb->active_extensions)) {
4829 __skb_ext_put(skb->extensions);
4830 skb->active_extensions = 0;
4834 static inline bool skb_has_extensions(struct sk_buff *skb)
4836 return unlikely(skb->active_extensions);
4839 static inline void skb_ext_put(struct sk_buff *skb) {}
4840 static inline void skb_ext_reset(struct sk_buff *skb) {}
4841 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
4842 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
4843 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
4844 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4845 #endif /* CONFIG_SKB_EXTENSIONS */
4847 static inline void nf_reset_ct(struct sk_buff *skb)
4849 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4850 nf_conntrack_put(skb_nfct(skb));
4855 static inline void nf_reset_trace(struct sk_buff *skb)
4857 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4862 static inline void ipvs_reset(struct sk_buff *skb)
4864 #if IS_ENABLED(CONFIG_IP_VS)
4865 skb->ipvs_property = 0;
4869 /* Note: This doesn't put any conntrack info in dst. */
4870 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4873 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4874 dst->_nfct = src->_nfct;
4875 nf_conntrack_get(skb_nfct(src));
4877 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4879 dst->nf_trace = src->nf_trace;
4883 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4885 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4886 nf_conntrack_put(skb_nfct(dst));
4888 dst->slow_gro = src->slow_gro;
4889 __nf_copy(dst, src, true);
4892 #ifdef CONFIG_NETWORK_SECMARK
4893 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4895 to->secmark = from->secmark;
4898 static inline void skb_init_secmark(struct sk_buff *skb)
4903 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4906 static inline void skb_init_secmark(struct sk_buff *skb)
4910 static inline int secpath_exists(const struct sk_buff *skb)
4913 return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4919 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4921 return !skb->destructor &&
4922 !secpath_exists(skb) &&
4924 !skb->_skb_refdst &&
4925 !skb_has_frag_list(skb);
4928 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4930 skb->queue_mapping = queue_mapping;
4933 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4935 return skb->queue_mapping;
4938 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4940 to->queue_mapping = from->queue_mapping;
4943 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4945 skb->queue_mapping = rx_queue + 1;
4948 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4950 return skb->queue_mapping - 1;
4953 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4955 return skb->queue_mapping != 0;
4958 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4960 skb->dst_pending_confirm = val;
4963 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4965 return skb->dst_pending_confirm != 0;
4968 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4971 return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4977 static inline bool skb_is_gso(const struct sk_buff *skb)
4979 return skb_shinfo(skb)->gso_size;
4982 /* Note: Should be called only if skb_is_gso(skb) is true */
4983 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4985 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4988 /* Note: Should be called only if skb_is_gso(skb) is true */
4989 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4991 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4994 /* Note: Should be called only if skb_is_gso(skb) is true */
4995 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4997 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
5000 static inline void skb_gso_reset(struct sk_buff *skb)
5002 skb_shinfo(skb)->gso_size = 0;
5003 skb_shinfo(skb)->gso_segs = 0;
5004 skb_shinfo(skb)->gso_type = 0;
5007 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
5010 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5012 shinfo->gso_size += increment;
5015 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
5018 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5020 shinfo->gso_size -= decrement;
5023 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
5025 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
5027 /* LRO sets gso_size but not gso_type, whereas if GSO is really
5028 * wanted then gso_type will be set. */
5029 const struct skb_shared_info *shinfo = skb_shinfo(skb);
5031 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
5032 unlikely(shinfo->gso_type == 0)) {
5033 __skb_warn_lro_forwarding(skb);
5039 static inline void skb_forward_csum(struct sk_buff *skb)
5041 /* Unfortunately we don't support this one. Any brave souls? */
5042 if (skb->ip_summed == CHECKSUM_COMPLETE)
5043 skb->ip_summed = CHECKSUM_NONE;
5047 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
5048 * @skb: skb to check
5050 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
5051 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
5052 * use this helper, to document places where we make this assertion.
5054 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
5056 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
5059 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
5061 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
5062 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
5063 unsigned int transport_len,
5064 __sum16(*skb_chkf)(struct sk_buff *skb));
5067 * skb_head_is_locked - Determine if the skb->head is locked down
5068 * @skb: skb to check
5070 * The head on skbs build around a head frag can be removed if they are
5071 * not cloned. This function returns true if the skb head is locked down
5072 * due to either being allocated via kmalloc, or by being a clone with
5073 * multiple references to the head.
5075 static inline bool skb_head_is_locked(const struct sk_buff *skb)
5077 return !skb->head_frag || skb_cloned(skb);
5080 /* Local Checksum Offload.
5081 * Compute outer checksum based on the assumption that the
5082 * inner checksum will be offloaded later.
5083 * See Documentation/networking/checksum-offloads.rst for
5084 * explanation of how this works.
5085 * Fill in outer checksum adjustment (e.g. with sum of outer
5086 * pseudo-header) before calling.
5087 * Also ensure that inner checksum is in linear data area.
5089 static inline __wsum lco_csum(struct sk_buff *skb)
5091 unsigned char *csum_start = skb_checksum_start(skb);
5092 unsigned char *l4_hdr = skb_transport_header(skb);
5095 /* Start with complement of inner checksum adjustment */
5096 partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
5099 /* Add in checksum of our headers (incl. outer checksum
5100 * adjustment filled in by caller) and return result.
5102 return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
5105 static inline bool skb_is_redirected(const struct sk_buff *skb)
5107 return skb->redirected;
5110 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
5112 skb->redirected = 1;
5113 #ifdef CONFIG_NET_REDIRECT
5114 skb->from_ingress = from_ingress;
5115 if (skb->from_ingress)
5116 skb_clear_tstamp(skb);
5120 static inline void skb_reset_redirect(struct sk_buff *skb)
5122 skb->redirected = 0;
5125 static inline void skb_set_redirected_noclear(struct sk_buff *skb,
5128 skb->redirected = 1;
5129 #ifdef CONFIG_NET_REDIRECT
5130 skb->from_ingress = from_ingress;
5134 static inline bool skb_csum_is_sctp(struct sk_buff *skb)
5136 #if IS_ENABLED(CONFIG_IP_SCTP)
5137 return skb->csum_not_inet;
5143 static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
5145 skb->ip_summed = CHECKSUM_NONE;
5146 #if IS_ENABLED(CONFIG_IP_SCTP)
5147 skb->csum_not_inet = 0;
5151 static inline void skb_set_kcov_handle(struct sk_buff *skb,
5152 const u64 kcov_handle)
5155 skb->kcov_handle = kcov_handle;
5159 static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
5162 return skb->kcov_handle;
5168 static inline void skb_mark_for_recycle(struct sk_buff *skb)
5170 #ifdef CONFIG_PAGE_POOL
5171 skb->pp_recycle = 1;
5175 ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter,
5176 ssize_t maxsize, gfp_t gfp);
5178 #endif /* __KERNEL__ */
5179 #endif /* _LINUX_SKBUFF_H */