1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Definitions for the 'struct sk_buff' memory handlers.
4 *
5 * Authors:
6 * Alan Cox, <gw4pts@gw4pts.ampr.org>
7 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 */
9
10#ifndef _LINUX_SKBUFF_H
11#define _LINUX_SKBUFF_H
12
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>
22
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>
34#include <linux/page_frag_cache.h>
35#include <net/flow.h>
36#if IS_ENABLED(CONFIG_NF_CONNTRACK)
37#include <linux/netfilter/nf_conntrack_common.h>
38#endif
39#include <net/net_debug.h>
40#include <net/dropreason-core.h>
41#include <net/netmem.h>
42
43/**
44 * DOC: skb checksums
45 *
46 * The interface for checksum offload between the stack and networking drivers
47 * is as follows...
48 *
49 * IP checksum related features
50 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
51 *
52 * Drivers advertise checksum offload capabilities in the features of a device.
53 * From the stack's point of view these are capabilities offered by the driver.
54 * A driver typically only advertises features that it is capable of offloading
55 * to its device.
56 *
57 * .. flat-table:: Checksum related device features
58 * :widths: 1 10
59 *
60 * * - %NETIF_F_HW_CSUM
61 * - The driver (or its device) is able to compute one
62 * IP (one's complement) checksum for any combination
63 * of protocols or protocol layering. The checksum is
64 * computed and set in a packet per the CHECKSUM_PARTIAL
65 * interface (see below).
66 *
67 * * - %NETIF_F_IP_CSUM
68 * - Driver (device) is only able to checksum plain
69 * TCP or UDP packets over IPv4. These are specifically
70 * unencapsulated packets of the form IPv4|TCP or
71 * IPv4|UDP where the Protocol field in the IPv4 header
72 * is TCP or UDP. The IPv4 header may contain IP options.
73 * This feature cannot be set in features for a device
74 * with NETIF_F_HW_CSUM also set. This feature is being
75 * DEPRECATED (see below).
76 *
77 * * - %NETIF_F_IPV6_CSUM
78 * - Driver (device) is only able to checksum plain
79 * TCP or UDP packets over IPv6. These are specifically
80 * unencapsulated packets of the form IPv6|TCP or
81 * IPv6|UDP where the Next Header field in the IPv6
82 * header is either TCP or UDP. IPv6 extension headers
83 * are not supported with this feature. This feature
84 * cannot be set in features for a device with
85 * NETIF_F_HW_CSUM also set. This feature is being
86 * DEPRECATED (see below).
87 *
88 * * - %NETIF_F_RXCSUM
89 * - Driver (device) performs receive checksum offload.
90 * This flag is only used to disable the RX checksum
91 * feature for a device. The stack will accept receive
92 * checksum indication in packets received on a device
93 * regardless of whether NETIF_F_RXCSUM is set.
94 *
95 * Checksumming of received packets by device
96 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
97 *
98 * Indication of checksum verification is set in &sk_buff.ip_summed.
99 * Possible values are:
100 *
101 * - %CHECKSUM_NONE
102 *
103 * Device did not checksum this packet e.g. due to lack of capabilities.
104 * The packet contains full (though not verified) checksum in packet but
105 * not in skb->csum. Thus, skb->csum is undefined in this case.
106 *
107 * - %CHECKSUM_UNNECESSARY
108 *
109 * The hardware you're dealing with doesn't calculate the full checksum
110 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
111 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
112 * if their checksums are okay. &sk_buff.csum is still undefined in this case
113 * though. A driver or device must never modify the checksum field in the
114 * packet even if checksum is verified.
115 *
116 * %CHECKSUM_UNNECESSARY is applicable to following protocols:
117 *
118 * - TCP: IPv6 and IPv4.
119 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
120 * zero UDP checksum for either IPv4 or IPv6, the networking stack
121 * may perform further validation in this case.
122 * - GRE: only if the checksum is present in the header.
123 * - SCTP: indicates the CRC in SCTP header has been validated.
124 * - FCOE: indicates the CRC in FC frame has been validated.
125 *
126 * &sk_buff.csum_level indicates the number of consecutive checksums found in
127 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
128 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
129 * and a device is able to verify the checksums for UDP (possibly zero),
130 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
131 * two. If the device were only able to verify the UDP checksum and not
132 * GRE, either because it doesn't support GRE checksum or because GRE
133 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
134 * not considered in this case).
135 *
136 * - %CHECKSUM_COMPLETE
137 *
138 * This is the most generic way. The device supplied checksum of the _whole_
139 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
140 * hardware doesn't need to parse L3/L4 headers to implement this.
141 *
142 * Notes:
143 *
144 * - Even if device supports only some protocols, but is able to produce
145 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
146 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
147 *
148 * - %CHECKSUM_PARTIAL
149 *
150 * A checksum is set up to be offloaded to a device as described in the
151 * output description for CHECKSUM_PARTIAL. This may occur on a packet
152 * received directly from another Linux OS, e.g., a virtualized Linux kernel
153 * on the same host, or it may be set in the input path in GRO or remote
154 * checksum offload. For the purposes of checksum verification, the checksum
155 * referred to by skb->csum_start + skb->csum_offset and any preceding
156 * checksums in the packet are considered verified. Any checksums in the
157 * packet that are after the checksum being offloaded are not considered to
158 * be verified.
159 *
160 * Checksumming on transmit for non-GSO
161 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
162 *
163 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
164 * Values are:
165 *
166 * - %CHECKSUM_PARTIAL
167 *
168 * The driver is required to checksum the packet as seen by hard_start_xmit()
169 * from &sk_buff.csum_start up to the end, and to record/write the checksum at
170 * offset &sk_buff.csum_start + &sk_buff.csum_offset.
171 * A driver may verify that the
172 * csum_start and csum_offset values are valid values given the length and
173 * offset of the packet, but it should not attempt to validate that the
174 * checksum refers to a legitimate transport layer checksum -- it is the
175 * purview of the stack to validate that csum_start and csum_offset are set
176 * correctly.
177 *
178 * When the stack requests checksum offload for a packet, the driver MUST
179 * ensure that the checksum is set correctly. A driver can either offload the
180 * checksum calculation to the device, or call skb_checksum_help (in the case
181 * that the device does not support offload for a particular checksum).
182 *
183 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
184 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
185 * checksum offload capability.
186 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
187 * on network device checksumming capabilities: if a packet does not match
188 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
189 * &sk_buff.csum_not_inet, see :ref:`crc`)
190 * is called to resolve the checksum.
191 *
192 * - %CHECKSUM_NONE
193 *
194 * The skb was already checksummed by the protocol, or a checksum is not
195 * required.
196 *
197 * - %CHECKSUM_UNNECESSARY
198 *
199 * This has the same meaning as CHECKSUM_NONE for checksum offload on
200 * output.
201 *
202 * - %CHECKSUM_COMPLETE
203 *
204 * Not used in checksum output. If a driver observes a packet with this value
205 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
206 *
207 * .. _crc:
208 *
209 * Non-IP checksum (CRC) offloads
210 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
211 *
212 * .. flat-table::
213 * :widths: 1 10
214 *
215 * * - %NETIF_F_SCTP_CRC
216 * - This feature indicates that a device is capable of
217 * offloading the SCTP CRC in a packet. To perform this offload the stack
218 * will set csum_start and csum_offset accordingly, set ip_summed to
219 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
220 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
221 * A driver that supports both IP checksum offload and SCTP CRC32c offload
222 * must verify which offload is configured for a packet by testing the
223 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
224 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
225 *
226 * * - %NETIF_F_FCOE_CRC
227 * - This feature indicates that a device is capable of offloading the FCOE
228 * CRC in a packet. To perform this offload the stack will set ip_summed
229 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset
230 * accordingly. Note that there is no indication in the skbuff that the
231 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
232 * both IP checksum offload and FCOE CRC offload must verify which offload
233 * is configured for a packet, presumably by inspecting packet headers.
234 *
235 * Checksumming on output with GSO
236 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
237 *
238 * In the case of a GSO packet (skb_is_gso() is true), checksum offload
239 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
240 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
241 * part of the GSO operation is implied. If a checksum is being offloaded
242 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
243 * csum_offset are set to refer to the outermost checksum being offloaded
244 * (two offloaded checksums are possible with UDP encapsulation).
245 */
246
247/* Don't change this without changing skb_csum_unnecessary! */
248#define CHECKSUM_NONE 0
249#define CHECKSUM_UNNECESSARY 1
250#define CHECKSUM_COMPLETE 2
251#define CHECKSUM_PARTIAL 3
252
253/* Maximum value in skb->csum_level */
254#define SKB_MAX_CSUM_LEVEL 3
255
256#define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
257#define SKB_WITH_OVERHEAD(X) \
258 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
259
260/* For X bytes available in skb->head, what is the minimal
261 * allocation needed, knowing struct skb_shared_info needs
262 * to be aligned.
263 */
264#define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \
265 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
266
267#define SKB_MAX_ORDER(X, ORDER) \
268 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
269#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
270#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
271
272/* return minimum truesize of one skb containing X bytes of data */
273#define SKB_TRUESIZE(X) ((X) + \
274 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
275 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
276
277struct net_device;
278struct scatterlist;
279struct pipe_inode_info;
280struct iov_iter;
281struct napi_struct;
282struct bpf_prog;
283union bpf_attr;
284struct skb_ext;
285struct ts_config;
286
287#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
288struct nf_bridge_info {
289 enum {
290 BRNF_PROTO_UNCHANGED,
291 BRNF_PROTO_8021Q,
292 BRNF_PROTO_PPPOE
293 } orig_proto:8;
294 u8 pkt_otherhost:1;
295 u8 in_prerouting:1;
296 u8 bridged_dnat:1;
297 u8 sabotage_in_done:1;
298 __u16 frag_max_size;
299 int physinif;
300
301 /* always valid & non-NULL from FORWARD on, for physdev match */
302 struct net_device *physoutdev;
303 union {
304 /* prerouting: detect dnat in orig/reply direction */
305 __be32 ipv4_daddr;
306 struct in6_addr ipv6_daddr;
307
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.
311 */
312 char neigh_header[8];
313 };
314};
315#endif
316
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.
321 */
322struct tc_skb_ext {
323 union {
324 u64 act_miss_cookie;
325 __u32 chain;
326 };
327 __u16 mru;
328 __u16 zone;
329 u8 post_ct:1;
330 u8 post_ct_snat:1;
331 u8 post_ct_dnat:1;
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 */
334};
335#endif
336
337struct 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;
342 );
343
344 __u32 qlen;
345 spinlock_t lock;
346};
347
348struct sk_buff;
349
350#ifndef CONFIG_MAX_SKB_FRAGS
351# define CONFIG_MAX_SKB_FRAGS 17
352#endif
353
354#define MAX_SKB_FRAGS CONFIG_MAX_SKB_FRAGS
355
356/* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
357 * segment using its current segmentation instead.
358 */
359#define GSO_BY_FRAGS 0xFFFF
360
361typedef struct skb_frag {
362 netmem_ref netmem;
363 unsigned int len;
364 unsigned int offset;
365} skb_frag_t;
366
367/**
368 * skb_frag_size() - Returns the size of a skb fragment
369 * @frag: skb fragment
370 */
371static inline unsigned int skb_frag_size(const skb_frag_t *frag)
372{
373 return frag->len;
374}
375
376/**
377 * skb_frag_size_set() - Sets the size of a skb fragment
378 * @frag: skb fragment
379 * @size: size of fragment
380 */
381static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
382{
383 frag->len = size;
384}
385
386/**
387 * skb_frag_size_add() - Increments the size of a skb fragment by @delta
388 * @frag: skb fragment
389 * @delta: value to add
390 */
391static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
392{
393 frag->len += delta;
394}
395
396/**
397 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
398 * @frag: skb fragment
399 * @delta: value to subtract
400 */
401static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
402{
403 frag->len -= delta;
404}
405
406/**
407 * skb_frag_must_loop - Test if %p is a high memory page
408 * @p: fragment's page
409 */
410static inline bool skb_frag_must_loop(struct page *p)
411{
412#if defined(CONFIG_HIGHMEM)
413 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
414 return true;
415#endif
416 return false;
417}
418
419/**
420 * skb_frag_foreach_page - loop over pages in a fragment
421 *
422 * @f: skb frag to operate on
423 * @f_off: offset from start of f->netmem
424 * @f_len: length from f_off to loop over
425 * @p: (temp var) current page
426 * @p_off: (temp var) offset from start of current page,
427 * non-zero only on first page.
428 * @p_len: (temp var) length in current page,
429 * < PAGE_SIZE only on first and last page.
430 * @copied: (temp var) length so far, excluding current p_len.
431 *
432 * A fragment can hold a compound page, in which case per-page
433 * operations, notably kmap_atomic, must be called for each
434 * regular page.
435 */
436#define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
437 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
438 p_off = (f_off) & (PAGE_SIZE - 1), \
439 p_len = skb_frag_must_loop(p) ? \
440 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
441 copied = 0; \
442 copied < f_len; \
443 copied += p_len, p++, p_off = 0, \
444 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
445
446/**
447 * struct skb_shared_hwtstamps - hardware time stamps
448 * @hwtstamp: hardware time stamp transformed into duration
449 * since arbitrary point in time
450 * @netdev_data: address/cookie of network device driver used as
451 * reference to actual hardware time stamp
452 *
453 * Software time stamps generated by ktime_get_real() are stored in
454 * skb->tstamp.
455 *
456 * hwtstamps can only be compared against other hwtstamps from
457 * the same device.
458 *
459 * This structure is attached to packets as part of the
460 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
461 */
462struct skb_shared_hwtstamps {
463 union {
464 ktime_t hwtstamp;
465 void *netdev_data;
466 };
467};
468
469/* Definitions for tx_flags in struct skb_shared_info */
470enum {
471 /* generate hardware time stamp */
472 SKBTX_HW_TSTAMP_NOBPF = 1 << 0,
473
474 /* generate software time stamp when queueing packet to NIC */
475 SKBTX_SW_TSTAMP = 1 << 1,
476
477 /* device driver is going to provide hardware time stamp */
478 SKBTX_IN_PROGRESS = 1 << 2,
479
480 /* generate software time stamp on packet tx completion */
481 SKBTX_COMPLETION_TSTAMP = 1 << 3,
482
483 /* determine hardware time stamp based on time or cycles */
484 SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
485
486 /* generate software time stamp when entering packet scheduling */
487 SKBTX_SCHED_TSTAMP = 1 << 6,
488
489 /* used for bpf extension when a bpf program is loaded */
490 SKBTX_BPF = 1 << 7,
491};
492
493#define SKBTX_HW_TSTAMP (SKBTX_HW_TSTAMP_NOBPF | SKBTX_BPF)
494
495#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
496 SKBTX_SCHED_TSTAMP | \
497 SKBTX_BPF | \
498 SKBTX_COMPLETION_TSTAMP)
499#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
500 SKBTX_ANY_SW_TSTAMP)
501
502/* Definitions for flags in struct skb_shared_info */
503enum {
504 /* use zcopy routines */
505 SKBFL_ZEROCOPY_ENABLE = BIT(0),
506
507 /* This indicates at least one fragment might be overwritten
508 * (as in vmsplice(), sendfile() ...)
509 * If we need to compute a TX checksum, we'll need to copy
510 * all frags to avoid possible bad checksum
511 */
512 SKBFL_SHARED_FRAG = BIT(1),
513
514 /* segment contains only zerocopy data and should not be
515 * charged to the kernel memory.
516 */
517 SKBFL_PURE_ZEROCOPY = BIT(2),
518
519 SKBFL_DONT_ORPHAN = BIT(3),
520
521 /* page references are managed by the ubuf_info, so it's safe to
522 * use frags only up until ubuf_info is released
523 */
524 SKBFL_MANAGED_FRAG_REFS = BIT(4),
525};
526
527#define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
528#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
529 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS)
530
531struct ubuf_info_ops {
532 void (*complete)(struct sk_buff *, struct ubuf_info *,
533 bool zerocopy_success);
534 /* has to be compatible with skb_zcopy_set() */
535 int (*link_skb)(struct sk_buff *skb, struct ubuf_info *uarg);
536};
537
538/*
539 * The callback notifies userspace to release buffers when skb DMA is done in
540 * lower device, the skb last reference should be 0 when calling this.
541 * The zerocopy_success argument is true if zero copy transmit occurred,
542 * false on data copy or out of memory error caused by data copy attempt.
543 * The ctx field is used to track device context.
544 * The desc field is used to track userspace buffer index.
545 */
546struct ubuf_info {
547 const struct ubuf_info_ops *ops;
548 refcount_t refcnt;
549 u8 flags;
550};
551
552struct ubuf_info_msgzc {
553 struct ubuf_info ubuf;
554
555 union {
556 struct {
557 unsigned long desc;
558 void *ctx;
559 };
560 struct {
561 u32 id;
562 u16 len;
563 u16 zerocopy:1;
564 u32 bytelen;
565 };
566 };
567
568 struct mmpin {
569 struct user_struct *user;
570 unsigned int num_pg;
571 } mmp;
572};
573
574#define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
575#define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \
576 ubuf)
577
578int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
579void mm_unaccount_pinned_pages(struct mmpin *mmp);
580
581/* Preserve some data across TX submission and completion.
582 *
583 * Note, this state is stored in the driver. Extending the layout
584 * might need some special care.
585 */
586struct xsk_tx_metadata_compl {
587 __u64 *tx_timestamp;
588};
589
590/* This data is invariant across clones and lives at
591 * the end of the header data, ie. at skb->end.
592 */
593struct skb_shared_info {
594 __u8 flags;
595 __u8 meta_len;
596 __u8 nr_frags;
597 __u8 tx_flags;
598 unsigned short gso_size;
599 /* Warning: this field is not always filled in (UFO)! */
600 unsigned short gso_segs;
601 struct sk_buff *frag_list;
602 union {
603 struct skb_shared_hwtstamps hwtstamps;
604 struct xsk_tx_metadata_compl xsk_meta;
605 };
606 unsigned int gso_type;
607 u32 tskey;
608
609 /*
610 * Warning : all fields before dataref are cleared in __alloc_skb()
611 */
612 atomic_t dataref;
613
614 union {
615 struct {
616 u32 xdp_frags_size;
617 u32 xdp_frags_truesize;
618 };
619
620 /*
621 * Intermediate layers must ensure that destructor_arg
622 * remains valid until skb destructor.
623 */
624 void *destructor_arg;
625 };
626
627 /* must be last field, see pskb_expand_head() */
628 skb_frag_t frags[MAX_SKB_FRAGS];
629};
630
631/**
632 * DOC: dataref and headerless skbs
633 *
634 * Transport layers send out clones of payload skbs they hold for
635 * retransmissions. To allow lower layers of the stack to prepend their headers
636 * we split &skb_shared_info.dataref into two halves.
637 * The lower 16 bits count the overall number of references.
638 * The higher 16 bits indicate how many of the references are payload-only.
639 * skb_header_cloned() checks if skb is allowed to add / write the headers.
640 *
641 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
642 * (via __skb_header_release()). Any clone created from marked skb will get
643 * &sk_buff.hdr_len populated with the available headroom.
644 * If there's the only clone in existence it's able to modify the headroom
645 * at will. The sequence of calls inside the transport layer is::
646 *
647 * <alloc skb>
648 * skb_reserve()
649 * __skb_header_release()
650 * skb_clone()
651 * // send the clone down the stack
652 *
653 * This is not a very generic construct and it depends on the transport layers
654 * doing the right thing. In practice there's usually only one payload-only skb.
655 * Having multiple payload-only skbs with different lengths of hdr_len is not
656 * possible. The payload-only skbs should never leave their owner.
657 */
658#define SKB_DATAREF_SHIFT 16
659#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
660
661
662enum {
663 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
664 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
665 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
666};
667
668enum {
669 SKB_GSO_TCPV4 = 1 << 0,
670
671 /* This indicates the skb is from an untrusted source. */
672 SKB_GSO_DODGY = 1 << 1,
673
674 /* This indicates the tcp segment has CWR set. */
675 SKB_GSO_TCP_ECN = 1 << 2,
676
677 __SKB_GSO_TCP_FIXEDID = 1 << 3,
678
679 SKB_GSO_TCPV6 = 1 << 4,
680
681 SKB_GSO_FCOE = 1 << 5,
682
683 SKB_GSO_GRE = 1 << 6,
684
685 SKB_GSO_GRE_CSUM = 1 << 7,
686
687 SKB_GSO_IPXIP4 = 1 << 8,
688
689 SKB_GSO_IPXIP6 = 1 << 9,
690
691 SKB_GSO_UDP_TUNNEL = 1 << 10,
692
693 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
694
695 SKB_GSO_PARTIAL = 1 << 12,
696
697 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
698
699 SKB_GSO_SCTP = 1 << 14,
700
701 SKB_GSO_ESP = 1 << 15,
702
703 SKB_GSO_UDP = 1 << 16,
704
705 SKB_GSO_UDP_L4 = 1 << 17,
706
707 SKB_GSO_FRAGLIST = 1 << 18,
708
709 SKB_GSO_TCP_ACCECN = 1 << 19,
710
711 /* These indirectly map onto the same netdev feature.
712 * If NETIF_F_TSO_MANGLEID is set it may mangle both inner and outer IDs.
713 */
714 SKB_GSO_TCP_FIXEDID = 1 << 30,
715 SKB_GSO_TCP_FIXEDID_INNER = 1 << 31,
716};
717
718#if BITS_PER_LONG > 32
719#define NET_SKBUFF_DATA_USES_OFFSET 1
720#endif
721
722#ifdef NET_SKBUFF_DATA_USES_OFFSET
723typedef unsigned int sk_buff_data_t;
724#else
725typedef unsigned char *sk_buff_data_t;
726#endif
727
728enum skb_tstamp_type {
729 SKB_CLOCK_REALTIME,
730 SKB_CLOCK_MONOTONIC,
731 SKB_CLOCK_TAI,
732 __SKB_CLOCK_MAX = SKB_CLOCK_TAI,
733};
734
735/**
736 * DOC: Basic sk_buff geometry
737 *
738 * struct sk_buff itself is a metadata structure and does not hold any packet
739 * data. All the data is held in associated buffers.
740 *
741 * &sk_buff.head points to the main "head" buffer. The head buffer is divided
742 * into two parts:
743 *
744 * - data buffer, containing headers and sometimes payload;
745 * this is the part of the skb operated on by the common helpers
746 * such as skb_put() or skb_pull();
747 * - shared info (struct skb_shared_info) which holds an array of pointers
748 * to read-only data in the (page, offset, length) format.
749 *
750 * Optionally &skb_shared_info.frag_list may point to another skb.
751 *
752 * Basic diagram may look like this::
753 *
754 * ---------------
755 * | sk_buff |
756 * ---------------
757 * ,--------------------------- + head
758 * / ,----------------- + data
759 * / / ,----------- + tail
760 * | | | , + end
761 * | | | |
762 * v v v v
763 * -----------------------------------------------
764 * | headroom | data | tailroom | skb_shared_info |
765 * -----------------------------------------------
766 * + [page frag]
767 * + [page frag]
768 * + [page frag]
769 * + [page frag] ---------
770 * + frag_list --> | sk_buff |
771 * ---------
772 *
773 */
774
775/**
776 * struct sk_buff - socket buffer
777 * @next: Next buffer in list
778 * @prev: Previous buffer in list
779 * @tstamp: Time we arrived/left
780 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
781 * for retransmit timer
782 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
783 * @list: queue head
784 * @ll_node: anchor in an llist (eg socket defer_list)
785 * @sk: Socket we are owned by
786 * @dev: Device we arrived on/are leaving by
787 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
788 * @cb: Control buffer. Free for use by every layer. Put private vars here
789 * @_skb_refdst: destination entry (with norefcount bit)
790 * @len: Length of actual data
791 * @data_len: Data length
792 * @mac_len: Length of link layer header
793 * @hdr_len: writable header length of cloned skb
794 * @csum: Checksum (must include start/offset pair)
795 * @csum_start: Offset from skb->head where checksumming should start
796 * @csum_offset: Offset from csum_start where checksum should be stored
797 * @priority: Packet queueing priority
798 * @ignore_df: allow local fragmentation
799 * @cloned: Head may be cloned (check refcnt to be sure)
800 * @ip_summed: Driver fed us an IP checksum
801 * @nohdr: Payload reference only, must not modify header
802 * @pkt_type: Packet class
803 * @fclone: skbuff clone status
804 * @ipvs_property: skbuff is owned by ipvs
805 * @inner_protocol_type: whether the inner protocol is
806 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
807 * @remcsum_offload: remote checksum offload is enabled
808 * @offload_fwd_mark: Packet was L2-forwarded in hardware
809 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
810 * @tc_skip_classify: do not classify packet. set by IFB device
811 * @tc_at_ingress: used within tc_classify to distinguish in/egress
812 * @redirected: packet was redirected by packet classifier
813 * @from_ingress: packet was redirected from the ingress path
814 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
815 * @peeked: this packet has been seen already, so stats have been
816 * done for it, don't do them again
817 * @nf_trace: netfilter packet trace flag
818 * @protocol: Packet protocol from driver
819 * @destructor: Destruct function
820 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
821 * @_sk_redir: socket redirection information for skmsg
822 * @_nfct: Associated connection, if any (with nfctinfo bits)
823 * @skb_iif: ifindex of device we arrived on
824 * @tc_index: Traffic control index
825 * @hash: the packet hash
826 * @queue_mapping: Queue mapping for multiqueue devices
827 * @head_frag: skb was allocated from page fragments,
828 * not allocated by kmalloc() or vmalloc().
829 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
830 * @pp_recycle: mark the packet for recycling instead of freeing (implies
831 * page_pool support on driver)
832 * @active_extensions: active extensions (skb_ext_id types)
833 * @ndisc_nodetype: router type (from link layer)
834 * @ooo_okay: allow the mapping of a socket to a queue to be changed
835 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
836 * ports.
837 * @sw_hash: indicates hash was computed in software stack
838 * @wifi_acked_valid: wifi_acked was set
839 * @wifi_acked: whether frame was acked on wifi or not
840 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
841 * @encapsulation: indicates the inner headers in the skbuff are valid
842 * @encap_hdr_csum: software checksum is needed
843 * @csum_valid: checksum is already valid
844 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
845 * @csum_complete_sw: checksum was completed by software
846 * @csum_level: indicates the number of consecutive checksums found in
847 * the packet minus one that have been verified as
848 * CHECKSUM_UNNECESSARY (max 3)
849 * @unreadable: indicates that at least 1 of the fragments in this skb is
850 * unreadable.
851 * @dst_pending_confirm: need to confirm neighbour
852 * @decrypted: Decrypted SKB
853 * @slow_gro: state present at GRO time, slower prepare step required
854 * @tstamp_type: When set, skb->tstamp has the
855 * delivery_time clock base of skb->tstamp.
856 * @napi_id: id of the NAPI struct this skb came from
857 * @sender_cpu: (aka @napi_id) source CPU in XPS
858 * @alloc_cpu: CPU which did the skb allocation.
859 * @secmark: security marking
860 * @mark: Generic packet mark
861 * @reserved_tailroom: (aka @mark) number of bytes of free space available
862 * at the tail of an sk_buff
863 * @vlan_all: vlan fields (proto & tci)
864 * @vlan_proto: vlan encapsulation protocol
865 * @vlan_tci: vlan tag control information
866 * @inner_protocol: Protocol (encapsulation)
867 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
868 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
869 * @inner_transport_header: Inner transport layer header (encapsulation)
870 * @inner_network_header: Network layer header (encapsulation)
871 * @inner_mac_header: Link layer header (encapsulation)
872 * @transport_header: Transport layer header
873 * @network_header: Network layer header
874 * @mac_header: Link layer header
875 * @kcov_handle: KCOV remote handle for remote coverage collection
876 * @tail: Tail pointer
877 * @end: End pointer
878 * @head: Head of buffer
879 * @data: Data head pointer
880 * @truesize: Buffer size
881 * @users: User count - see {datagram,tcp}.c
882 * @extensions: allocated extensions, valid if active_extensions is nonzero
883 */
884
885struct sk_buff {
886 union {
887 struct {
888 /* These two members must be first to match sk_buff_head. */
889 struct sk_buff *next;
890 struct sk_buff *prev;
891
892 union {
893 struct net_device *dev;
894 /* Some protocols might use this space to store information,
895 * while device pointer would be NULL.
896 * UDP receive path is one user.
897 */
898 unsigned long dev_scratch;
899 };
900 };
901 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
902 struct list_head list;
903 struct llist_node ll_node;
904 };
905
906 struct sock *sk;
907
908 union {
909 ktime_t tstamp;
910 u64 skb_mstamp_ns; /* earliest departure time */
911 };
912 /*
913 * This is the control buffer. It is free to use for every
914 * layer. Please put your private variables there. If you
915 * want to keep them across layers you have to do a skb_clone()
916 * first. This is owned by whoever has the skb queued ATM.
917 */
918 char cb[48] __aligned(8);
919
920 union {
921 struct {
922 unsigned long _skb_refdst;
923 void (*destructor)(struct sk_buff *skb);
924 };
925 struct list_head tcp_tsorted_anchor;
926#ifdef CONFIG_NET_SOCK_MSG
927 unsigned long _sk_redir;
928#endif
929 };
930
931#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
932 unsigned long _nfct;
933#endif
934 unsigned int len,
935 data_len;
936 __u16 mac_len,
937 hdr_len;
938
939 /* Following fields are _not_ copied in __copy_skb_header()
940 * Note that queue_mapping is here mostly to fill a hole.
941 */
942 __u16 queue_mapping;
943
944/* if you move cloned around you also must adapt those constants */
945#ifdef __BIG_ENDIAN_BITFIELD
946#define CLONED_MASK (1 << 7)
947#else
948#define CLONED_MASK 1
949#endif
950#define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset)
951
952 /* private: */
953 __u8 __cloned_offset[0];
954 /* public: */
955 __u8 cloned:1,
956 nohdr:1,
957 fclone:2,
958 peeked:1,
959 head_frag:1,
960 pfmemalloc:1,
961 pp_recycle:1; /* page_pool recycle indicator */
962#ifdef CONFIG_SKB_EXTENSIONS
963 __u8 active_extensions;
964#endif
965
966 /* Fields enclosed in headers group are copied
967 * using a single memcpy() in __copy_skb_header()
968 */
969 struct_group(headers,
970
971 /* private: */
972 __u8 __pkt_type_offset[0];
973 /* public: */
974 __u8 pkt_type:3; /* see PKT_TYPE_MAX */
975 __u8 ignore_df:1;
976 __u8 dst_pending_confirm:1;
977 __u8 ip_summed:2;
978 __u8 ooo_okay:1;
979
980 /* private: */
981 __u8 __mono_tc_offset[0];
982 /* public: */
983 __u8 tstamp_type:2; /* See skb_tstamp_type */
984#ifdef CONFIG_NET_XGRESS
985 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */
986 __u8 tc_skip_classify:1;
987#endif
988 __u8 remcsum_offload:1;
989 __u8 csum_complete_sw:1;
990 __u8 csum_level:2;
991 __u8 inner_protocol_type:1;
992
993 __u8 l4_hash:1;
994 __u8 sw_hash:1;
995#ifdef CONFIG_WIRELESS
996 __u8 wifi_acked_valid:1;
997 __u8 wifi_acked:1;
998#endif
999 __u8 no_fcs:1;
1000 /* Indicates the inner headers are valid in the skbuff. */
1001 __u8 encapsulation:1;
1002 __u8 encap_hdr_csum:1;
1003 __u8 csum_valid:1;
1004#ifdef CONFIG_IPV6_NDISC_NODETYPE
1005 __u8 ndisc_nodetype:2;
1006#endif
1007
1008#if IS_ENABLED(CONFIG_IP_VS)
1009 __u8 ipvs_property:1;
1010#endif
1011#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
1012 __u8 nf_trace:1;
1013#endif
1014#ifdef CONFIG_NET_SWITCHDEV
1015 __u8 offload_fwd_mark:1;
1016 __u8 offload_l3_fwd_mark:1;
1017#endif
1018 __u8 redirected:1;
1019#ifdef CONFIG_NET_REDIRECT
1020 __u8 from_ingress:1;
1021#endif
1022#ifdef CONFIG_NETFILTER_SKIP_EGRESS
1023 __u8 nf_skip_egress:1;
1024#endif
1025#ifdef CONFIG_SKB_DECRYPTED
1026 __u8 decrypted:1;
1027#endif
1028 __u8 slow_gro:1;
1029#if IS_ENABLED(CONFIG_IP_SCTP)
1030 __u8 csum_not_inet:1;
1031#endif
1032 __u8 unreadable:1;
1033#if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS)
1034 __u16 tc_index; /* traffic control index */
1035#endif
1036
1037 u16 alloc_cpu;
1038
1039 union {
1040 __wsum csum;
1041 struct {
1042 __u16 csum_start;
1043 __u16 csum_offset;
1044 };
1045 };
1046 __u32 priority;
1047 int skb_iif;
1048 __u32 hash;
1049 union {
1050 u32 vlan_all;
1051 struct {
1052 __be16 vlan_proto;
1053 __u16 vlan_tci;
1054 };
1055 };
1056#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
1057 union {
1058 unsigned int napi_id;
1059 unsigned int sender_cpu;
1060 };
1061#endif
1062#ifdef CONFIG_NETWORK_SECMARK
1063 __u32 secmark;
1064#endif
1065
1066 union {
1067 __u32 mark;
1068 __u32 reserved_tailroom;
1069 };
1070
1071 union {
1072 __be16 inner_protocol;
1073 __u8 inner_ipproto;
1074 };
1075
1076 __u16 inner_transport_header;
1077 __u16 inner_network_header;
1078 __u16 inner_mac_header;
1079
1080 __be16 protocol;
1081 __u16 transport_header;
1082 __u16 network_header;
1083 __u16 mac_header;
1084
1085#ifdef CONFIG_KCOV
1086 u64 kcov_handle;
1087#endif
1088
1089 ); /* end headers group */
1090
1091 /* These elements must be at the end, see alloc_skb() for details. */
1092 sk_buff_data_t tail;
1093 sk_buff_data_t end;
1094 unsigned char *head,
1095 *data;
1096 unsigned int truesize;
1097 refcount_t users;
1098
1099#ifdef CONFIG_SKB_EXTENSIONS
1100 /* only usable after checking ->active_extensions != 0 */
1101 struct skb_ext *extensions;
1102#endif
1103};
1104
1105/* if you move pkt_type around you also must adapt those constants */
1106#ifdef __BIG_ENDIAN_BITFIELD
1107#define PKT_TYPE_MAX (7 << 5)
1108#else
1109#define PKT_TYPE_MAX 7
1110#endif
1111#define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
1112
1113/* if you move tc_at_ingress or tstamp_type
1114 * around, you also must adapt these constants.
1115 */
1116#ifdef __BIG_ENDIAN_BITFIELD
1117#define SKB_TSTAMP_TYPE_MASK (3 << 6)
1118#define SKB_TSTAMP_TYPE_RSHIFT (6)
1119#define TC_AT_INGRESS_MASK (1 << 5)
1120#else
1121#define SKB_TSTAMP_TYPE_MASK (3)
1122#define TC_AT_INGRESS_MASK (1 << 2)
1123#endif
1124#define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset)
1125
1126#ifdef __KERNEL__
1127/*
1128 * Handling routines are only of interest to the kernel
1129 */
1130
1131#define SKB_ALLOC_FCLONE 0x01
1132#define SKB_ALLOC_RX 0x02
1133#define SKB_ALLOC_NAPI 0x04
1134
1135/**
1136 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1137 * @skb: buffer
1138 */
1139static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1140{
1141 return unlikely(skb->pfmemalloc);
1142}
1143
1144/*
1145 * skb might have a dst pointer attached, refcounted or not.
1146 * _skb_refdst low order bit is set if refcount was _not_ taken
1147 */
1148#define SKB_DST_NOREF 1UL
1149#define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
1150
1151/**
1152 * skb_dst - returns skb dst_entry
1153 * @skb: buffer
1154 *
1155 * Returns: skb dst_entry, regardless of reference taken or not.
1156 */
1157static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
1158{
1159 /* If refdst was not refcounted, check we still are in a
1160 * rcu_read_lock section
1161 */
1162 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1163 !rcu_read_lock_held() &&
1164 !rcu_read_lock_bh_held());
1165 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1166}
1167
1168static inline void skb_dst_check_unset(struct sk_buff *skb)
1169{
1170 DEBUG_NET_WARN_ON_ONCE((skb->_skb_refdst & SKB_DST_PTRMASK) &&
1171 !(skb->_skb_refdst & SKB_DST_NOREF));
1172}
1173
1174/**
1175 * skb_dstref_steal() - return current dst_entry value and clear it
1176 * @skb: buffer
1177 *
1178 * Resets skb dst_entry without adjusting its reference count. Useful in
1179 * cases where dst_entry needs to be temporarily reset and restored.
1180 * Note that the returned value cannot be used directly because it
1181 * might contain SKB_DST_NOREF bit.
1182 *
1183 * When in doubt, prefer skb_dst_drop() over skb_dstref_steal() to correctly
1184 * handle dst_entry reference counting.
1185 *
1186 * Returns: original skb dst_entry.
1187 */
1188static inline unsigned long skb_dstref_steal(struct sk_buff *skb)
1189{
1190 unsigned long refdst = skb->_skb_refdst;
1191
1192 skb->_skb_refdst = 0;
1193 return refdst;
1194}
1195
1196/**
1197 * skb_dstref_restore() - restore skb dst_entry removed via skb_dstref_steal()
1198 * @skb: buffer
1199 * @refdst: dst entry from a call to skb_dstref_steal()
1200 */
1201static inline void skb_dstref_restore(struct sk_buff *skb, unsigned long refdst)
1202{
1203 skb_dst_check_unset(skb);
1204 skb->_skb_refdst = refdst;
1205}
1206
1207/**
1208 * skb_dst_set - sets skb dst
1209 * @skb: buffer
1210 * @dst: dst entry
1211 *
1212 * Sets skb dst, assuming a reference was taken on dst and should
1213 * be released by skb_dst_drop()
1214 */
1215static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
1216{
1217 skb_dst_check_unset(skb);
1218 skb->slow_gro |= !!dst;
1219 skb->_skb_refdst = (unsigned long)dst;
1220}
1221
1222/**
1223 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1224 * @skb: buffer
1225 * @dst: dst entry
1226 *
1227 * Sets skb dst, assuming a reference was not taken on dst.
1228 * If dst entry is cached, we do not take reference and dst_release
1229 * will be avoided by refdst_drop. If dst entry is not cached, we take
1230 * reference, so that last dst_release can destroy the dst immediately.
1231 */
1232static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1233{
1234 skb_dst_check_unset(skb);
1235 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1236 skb->slow_gro |= !!dst;
1237 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1238}
1239
1240/**
1241 * skb_dst_is_noref - Test if skb dst isn't refcounted
1242 * @skb: buffer
1243 */
1244static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1245{
1246 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1247}
1248
1249/* For mangling skb->pkt_type from user space side from applications
1250 * such as nft, tc, etc, we only allow a conservative subset of
1251 * possible pkt_types to be set.
1252*/
1253static inline bool skb_pkt_type_ok(u32 ptype)
1254{
1255 return ptype <= PACKET_OTHERHOST;
1256}
1257
1258/**
1259 * skb_napi_id - Returns the skb's NAPI id
1260 * @skb: buffer
1261 */
1262static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1263{
1264#ifdef CONFIG_NET_RX_BUSY_POLL
1265 return skb->napi_id;
1266#else
1267 return 0;
1268#endif
1269}
1270
1271static inline bool skb_wifi_acked_valid(const struct sk_buff *skb)
1272{
1273#ifdef CONFIG_WIRELESS
1274 return skb->wifi_acked_valid;
1275#else
1276 return 0;
1277#endif
1278}
1279
1280/**
1281 * skb_unref - decrement the skb's reference count
1282 * @skb: buffer
1283 *
1284 * Returns: true if we can free the skb.
1285 */
1286static inline bool skb_unref(struct sk_buff *skb)
1287{
1288 if (unlikely(!skb))
1289 return false;
1290 if (!IS_ENABLED(CONFIG_DEBUG_NET) && likely(refcount_read(&skb->users) == 1))
1291 smp_rmb();
1292 else if (likely(!refcount_dec_and_test(&skb->users)))
1293 return false;
1294
1295 return true;
1296}
1297
1298static inline bool skb_data_unref(const struct sk_buff *skb,
1299 struct skb_shared_info *shinfo)
1300{
1301 int bias;
1302
1303 if (!skb->cloned)
1304 return true;
1305
1306 bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1;
1307
1308 if (atomic_read(v: &shinfo->dataref) == bias)
1309 smp_rmb();
1310 else if (atomic_sub_return(i: bias, v: &shinfo->dataref))
1311 return false;
1312
1313 return true;
1314}
1315
1316void __fix_address sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb,
1317 enum skb_drop_reason reason);
1318
1319static inline void
1320kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason)
1321{
1322 sk_skb_reason_drop(NULL, skb, reason);
1323}
1324
1325/**
1326 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1327 * @skb: buffer to free
1328 */
1329static inline void kfree_skb(struct sk_buff *skb)
1330{
1331 kfree_skb_reason(skb, reason: SKB_DROP_REASON_NOT_SPECIFIED);
1332}
1333
1334void skb_release_head_state(struct sk_buff *skb);
1335void kfree_skb_list_reason(struct sk_buff *segs,
1336 enum skb_drop_reason reason);
1337void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1338void skb_tx_error(struct sk_buff *skb);
1339
1340static inline void kfree_skb_list(struct sk_buff *segs)
1341{
1342 kfree_skb_list_reason(segs, reason: SKB_DROP_REASON_NOT_SPECIFIED);
1343}
1344
1345#ifdef CONFIG_TRACEPOINTS
1346void consume_skb(struct sk_buff *skb);
1347#else
1348static inline void consume_skb(struct sk_buff *skb)
1349{
1350 return kfree_skb(skb);
1351}
1352#endif
1353
1354void __consume_stateless_skb(struct sk_buff *skb);
1355void __kfree_skb(struct sk_buff *skb);
1356
1357void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1358bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1359 bool *fragstolen, int *delta_truesize);
1360
1361struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1362 int node);
1363struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1364struct sk_buff *build_skb(void *data, unsigned int frag_size);
1365struct sk_buff *build_skb_around(struct sk_buff *skb,
1366 void *data, unsigned int frag_size);
1367void skb_attempt_defer_free(struct sk_buff *skb);
1368
1369u32 napi_skb_cache_get_bulk(void **skbs, u32 n);
1370struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1371struct sk_buff *slab_build_skb(void *data);
1372
1373/**
1374 * alloc_skb - allocate a network buffer
1375 * @size: size to allocate
1376 * @priority: allocation mask
1377 *
1378 * This function is a convenient wrapper around __alloc_skb().
1379 */
1380static inline struct sk_buff *alloc_skb(unsigned int size,
1381 gfp_t priority)
1382{
1383 return __alloc_skb(size, priority, flags: 0, NUMA_NO_NODE);
1384}
1385
1386struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1387 unsigned long data_len,
1388 int max_page_order,
1389 int *errcode,
1390 gfp_t gfp_mask);
1391struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1392
1393/* Layout of fast clones : [skb1][skb2][fclone_ref] */
1394struct sk_buff_fclones {
1395 struct sk_buff skb1;
1396
1397 struct sk_buff skb2;
1398
1399 refcount_t fclone_ref;
1400};
1401
1402/**
1403 * skb_fclone_busy - check if fclone is busy
1404 * @sk: socket
1405 * @skb: buffer
1406 *
1407 * Returns: true if skb is a fast clone, and its clone is not freed.
1408 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1409 * so we also check that didn't happen.
1410 */
1411static inline bool skb_fclone_busy(const struct sock *sk,
1412 const struct sk_buff *skb)
1413{
1414 const struct sk_buff_fclones *fclones;
1415
1416 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1417
1418 return skb->fclone == SKB_FCLONE_ORIG &&
1419 refcount_read(r: &fclones->fclone_ref) > 1 &&
1420 READ_ONCE(fclones->skb2.sk) == sk;
1421}
1422
1423/**
1424 * alloc_skb_fclone - allocate a network buffer from fclone cache
1425 * @size: size to allocate
1426 * @priority: allocation mask
1427 *
1428 * This function is a convenient wrapper around __alloc_skb().
1429 */
1430static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1431 gfp_t priority)
1432{
1433 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1434}
1435
1436struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1437void skb_headers_offset_update(struct sk_buff *skb, int off);
1438int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1439struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1440void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1441struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1442struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1443 gfp_t gfp_mask, bool fclone);
1444static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1445 gfp_t gfp_mask)
1446{
1447 return __pskb_copy_fclone(skb, headroom, gfp_mask, fclone: false);
1448}
1449
1450int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1451struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1452 unsigned int headroom);
1453struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom);
1454struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1455 int newtailroom, gfp_t priority);
1456int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1457 int offset, int len);
1458int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1459 int offset, int len);
1460int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1461int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1462
1463/**
1464 * skb_pad - zero pad the tail of an skb
1465 * @skb: buffer to pad
1466 * @pad: space to pad
1467 *
1468 * Ensure that a buffer is followed by a padding area that is zero
1469 * filled. Used by network drivers which may DMA or transfer data
1470 * beyond the buffer end onto the wire.
1471 *
1472 * May return error in out of memory cases. The skb is freed on error.
1473 */
1474static inline int skb_pad(struct sk_buff *skb, int pad)
1475{
1476 return __skb_pad(skb, pad, free_on_error: true);
1477}
1478#define dev_kfree_skb(a) consume_skb(a)
1479
1480int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1481 int offset, size_t size, size_t max_frags);
1482
1483struct skb_seq_state {
1484 __u32 lower_offset;
1485 __u32 upper_offset;
1486 __u32 frag_idx;
1487 __u32 stepped_offset;
1488 struct sk_buff *root_skb;
1489 struct sk_buff *cur_skb;
1490 __u8 *frag_data;
1491 __u32 frag_off;
1492};
1493
1494void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1495 unsigned int to, struct skb_seq_state *st);
1496unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1497 struct skb_seq_state *st);
1498void skb_abort_seq_read(struct skb_seq_state *st);
1499int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len);
1500
1501unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1502 unsigned int to, struct ts_config *config);
1503
1504/*
1505 * Packet hash types specify the type of hash in skb_set_hash.
1506 *
1507 * Hash types refer to the protocol layer addresses which are used to
1508 * construct a packet's hash. The hashes are used to differentiate or identify
1509 * flows of the protocol layer for the hash type. Hash types are either
1510 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1511 *
1512 * Properties of hashes:
1513 *
1514 * 1) Two packets in different flows have different hash values
1515 * 2) Two packets in the same flow should have the same hash value
1516 *
1517 * A hash at a higher layer is considered to be more specific. A driver should
1518 * set the most specific hash possible.
1519 *
1520 * A driver cannot indicate a more specific hash than the layer at which a hash
1521 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1522 *
1523 * A driver may indicate a hash level which is less specific than the
1524 * actual layer the hash was computed on. For instance, a hash computed
1525 * at L4 may be considered an L3 hash. This should only be done if the
1526 * driver can't unambiguously determine that the HW computed the hash at
1527 * the higher layer. Note that the "should" in the second property above
1528 * permits this.
1529 */
1530enum pkt_hash_types {
1531 PKT_HASH_TYPE_NONE, /* Undefined type */
1532 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1533 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1534 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1535};
1536
1537static inline void skb_clear_hash(struct sk_buff *skb)
1538{
1539 skb->hash = 0;
1540 skb->sw_hash = 0;
1541 skb->l4_hash = 0;
1542}
1543
1544static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1545{
1546 if (!skb->l4_hash)
1547 skb_clear_hash(skb);
1548}
1549
1550static inline void
1551__skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1552{
1553 skb->l4_hash = is_l4;
1554 skb->sw_hash = is_sw;
1555 skb->hash = hash;
1556}
1557
1558static inline void
1559skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1560{
1561 /* Used by drivers to set hash from HW */
1562 __skb_set_hash(skb, hash, is_sw: false, is_l4: type == PKT_HASH_TYPE_L4);
1563}
1564
1565static inline void
1566__skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1567{
1568 __skb_set_hash(skb, hash, is_sw: true, is_l4);
1569}
1570
1571u32 __skb_get_hash_symmetric_net(const struct net *net, const struct sk_buff *skb);
1572
1573static inline u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1574{
1575 return __skb_get_hash_symmetric_net(NULL, skb);
1576}
1577
1578void __skb_get_hash_net(const struct net *net, struct sk_buff *skb);
1579u32 skb_get_poff(const struct sk_buff *skb);
1580u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1581 const struct flow_keys_basic *keys, int hlen);
1582__be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1583 const void *data, int hlen_proto);
1584
1585void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1586 const struct flow_dissector_key *key,
1587 unsigned int key_count);
1588
1589struct bpf_flow_dissector;
1590u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1591 __be16 proto, int nhoff, int hlen, unsigned int flags);
1592
1593bool __skb_flow_dissect(const struct net *net,
1594 const struct sk_buff *skb,
1595 struct flow_dissector *flow_dissector,
1596 void *target_container, const void *data,
1597 __be16 proto, int nhoff, int hlen, unsigned int flags);
1598
1599static inline bool skb_flow_dissect(const struct sk_buff *skb,
1600 struct flow_dissector *flow_dissector,
1601 void *target_container, unsigned int flags)
1602{
1603 return __skb_flow_dissect(NULL, skb, flow_dissector,
1604 target_container, NULL, proto: 0, nhoff: 0, hlen: 0, flags);
1605}
1606
1607static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1608 struct flow_keys *flow,
1609 unsigned int flags)
1610{
1611 memset(s: flow, c: 0, n: sizeof(*flow));
1612 return __skb_flow_dissect(NULL, skb, flow_dissector: &flow_keys_dissector,
1613 target_container: flow, NULL, proto: 0, nhoff: 0, hlen: 0, flags);
1614}
1615
1616static inline bool
1617skb_flow_dissect_flow_keys_basic(const struct net *net,
1618 const struct sk_buff *skb,
1619 struct flow_keys_basic *flow,
1620 const void *data, __be16 proto,
1621 int nhoff, int hlen, unsigned int flags)
1622{
1623 memset(s: flow, c: 0, n: sizeof(*flow));
1624 return __skb_flow_dissect(net, skb, flow_dissector: &flow_keys_basic_dissector, target_container: flow,
1625 data, proto, nhoff, hlen, flags);
1626}
1627
1628void skb_flow_dissect_meta(const struct sk_buff *skb,
1629 struct flow_dissector *flow_dissector,
1630 void *target_container);
1631
1632/* Gets a skb connection tracking info, ctinfo map should be a
1633 * map of mapsize to translate enum ip_conntrack_info states
1634 * to user states.
1635 */
1636void
1637skb_flow_dissect_ct(const struct sk_buff *skb,
1638 struct flow_dissector *flow_dissector,
1639 void *target_container,
1640 u16 *ctinfo_map, size_t mapsize,
1641 bool post_ct, u16 zone);
1642void
1643skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1644 struct flow_dissector *flow_dissector,
1645 void *target_container);
1646
1647void skb_flow_dissect_hash(const struct sk_buff *skb,
1648 struct flow_dissector *flow_dissector,
1649 void *target_container);
1650
1651static inline __u32 skb_get_hash_net(const struct net *net, struct sk_buff *skb)
1652{
1653 if (!skb->l4_hash && !skb->sw_hash)
1654 __skb_get_hash_net(net, skb);
1655
1656 return skb->hash;
1657}
1658
1659static inline __u32 skb_get_hash(struct sk_buff *skb)
1660{
1661 if (!skb->l4_hash && !skb->sw_hash)
1662 __skb_get_hash_net(NULL, skb);
1663
1664 return skb->hash;
1665}
1666
1667static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1668{
1669 if (!skb->l4_hash && !skb->sw_hash) {
1670 struct flow_keys keys;
1671 __u32 hash = __get_hash_from_flowi6(fl6, keys: &keys);
1672
1673 __skb_set_sw_hash(skb, hash, is_l4: flow_keys_have_l4(keys: &keys));
1674 }
1675
1676 return skb->hash;
1677}
1678
1679__u32 skb_get_hash_perturb(const struct sk_buff *skb,
1680 const siphash_key_t *perturb);
1681
1682static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1683{
1684 return skb->hash;
1685}
1686
1687static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1688{
1689 to->hash = from->hash;
1690 to->sw_hash = from->sw_hash;
1691 to->l4_hash = from->l4_hash;
1692};
1693
1694static inline int skb_cmp_decrypted(const struct sk_buff *skb1,
1695 const struct sk_buff *skb2)
1696{
1697#ifdef CONFIG_SKB_DECRYPTED
1698 return skb2->decrypted - skb1->decrypted;
1699#else
1700 return 0;
1701#endif
1702}
1703
1704static inline bool skb_is_decrypted(const struct sk_buff *skb)
1705{
1706#ifdef CONFIG_SKB_DECRYPTED
1707 return skb->decrypted;
1708#else
1709 return false;
1710#endif
1711}
1712
1713static inline void skb_copy_decrypted(struct sk_buff *to,
1714 const struct sk_buff *from)
1715{
1716#ifdef CONFIG_SKB_DECRYPTED
1717 to->decrypted = from->decrypted;
1718#endif
1719}
1720
1721#ifdef NET_SKBUFF_DATA_USES_OFFSET
1722static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1723{
1724 return skb->head + skb->end;
1725}
1726
1727static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1728{
1729 return skb->end;
1730}
1731
1732static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1733{
1734 skb->end = offset;
1735}
1736#else
1737static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1738{
1739 return skb->end;
1740}
1741
1742static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1743{
1744 return skb->end - skb->head;
1745}
1746
1747static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1748{
1749 skb->end = skb->head + offset;
1750}
1751#endif
1752
1753extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops;
1754
1755struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
1756 struct ubuf_info *uarg, bool devmem);
1757
1758void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1759
1760struct net_devmem_dmabuf_binding;
1761
1762int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
1763 struct sk_buff *skb, struct iov_iter *from,
1764 size_t length,
1765 struct net_devmem_dmabuf_binding *binding);
1766
1767int zerocopy_fill_skb_from_iter(struct sk_buff *skb,
1768 struct iov_iter *from, size_t length);
1769
1770static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1771 struct msghdr *msg, int len)
1772{
1773 return __zerocopy_sg_from_iter(msg, sk: skb->sk, skb, from: &msg->msg_iter, length: len,
1774 NULL);
1775}
1776
1777int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
1778 struct msghdr *msg, int len,
1779 struct ubuf_info *uarg,
1780 struct net_devmem_dmabuf_binding *binding);
1781
1782/* Internal */
1783#define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1784
1785static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1786{
1787 return &skb_shinfo(skb)->hwtstamps;
1788}
1789
1790static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1791{
1792 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1793
1794 return is_zcopy ? skb_uarg(skb) : NULL;
1795}
1796
1797static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1798{
1799 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1800}
1801
1802static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1803{
1804 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1805}
1806
1807static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1808 const struct sk_buff *skb2)
1809{
1810 return skb_zcopy_pure(skb: skb1) == skb_zcopy_pure(skb: skb2);
1811}
1812
1813static inline void net_zcopy_get(struct ubuf_info *uarg)
1814{
1815 refcount_inc(r: &uarg->refcnt);
1816}
1817
1818static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1819{
1820 skb_shinfo(skb)->destructor_arg = uarg;
1821 skb_shinfo(skb)->flags |= uarg->flags;
1822}
1823
1824static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1825 bool *have_ref)
1826{
1827 if (skb && uarg && !skb_zcopy(skb)) {
1828 if (unlikely(have_ref && *have_ref))
1829 *have_ref = false;
1830 else
1831 net_zcopy_get(uarg);
1832 skb_zcopy_init(skb, uarg);
1833 }
1834}
1835
1836static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1837{
1838 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1839 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1840}
1841
1842static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1843{
1844 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1845}
1846
1847static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1848{
1849 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1850}
1851
1852static inline void net_zcopy_put(struct ubuf_info *uarg)
1853{
1854 if (uarg)
1855 uarg->ops->complete(NULL, uarg, true);
1856}
1857
1858static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1859{
1860 if (uarg) {
1861 if (uarg->ops == &msg_zerocopy_ubuf_ops)
1862 msg_zerocopy_put_abort(uarg, have_uref);
1863 else if (have_uref)
1864 net_zcopy_put(uarg);
1865 }
1866}
1867
1868/* Release a reference on a zerocopy structure */
1869static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1870{
1871 struct ubuf_info *uarg = skb_zcopy(skb);
1872
1873 if (uarg) {
1874 if (!skb_zcopy_is_nouarg(skb))
1875 uarg->ops->complete(skb, uarg, zerocopy_success);
1876
1877 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1878 }
1879}
1880
1881void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1882
1883static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1884{
1885 if (unlikely(skb_zcopy_managed(skb)))
1886 __skb_zcopy_downgrade_managed(skb);
1887}
1888
1889/* Return true if frags in this skb are readable by the host. */
1890static inline bool skb_frags_readable(const struct sk_buff *skb)
1891{
1892 return !skb->unreadable;
1893}
1894
1895static inline void skb_mark_not_on_list(struct sk_buff *skb)
1896{
1897 skb->next = NULL;
1898}
1899
1900static inline void skb_poison_list(struct sk_buff *skb)
1901{
1902#ifdef CONFIG_DEBUG_NET
1903 skb->next = SKB_LIST_POISON_NEXT;
1904#endif
1905}
1906
1907/* Iterate through singly-linked GSO fragments of an skb. */
1908#define skb_list_walk_safe(first, skb, next_skb) \
1909 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1910 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1911
1912static inline void skb_list_del_init(struct sk_buff *skb)
1913{
1914 __list_del_entry(entry: &skb->list);
1915 skb_mark_not_on_list(skb);
1916}
1917
1918/**
1919 * skb_queue_empty - check if a queue is empty
1920 * @list: queue head
1921 *
1922 * Returns true if the queue is empty, false otherwise.
1923 */
1924static inline int skb_queue_empty(const struct sk_buff_head *list)
1925{
1926 return list->next == (const struct sk_buff *) list;
1927}
1928
1929/**
1930 * skb_queue_empty_lockless - check if a queue is empty
1931 * @list: queue head
1932 *
1933 * Returns true if the queue is empty, false otherwise.
1934 * This variant can be used in lockless contexts.
1935 */
1936static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1937{
1938 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1939}
1940
1941
1942/**
1943 * skb_queue_is_last - check if skb is the last entry in the queue
1944 * @list: queue head
1945 * @skb: buffer
1946 *
1947 * Returns true if @skb is the last buffer on the list.
1948 */
1949static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1950 const struct sk_buff *skb)
1951{
1952 return skb->next == (const struct sk_buff *) list;
1953}
1954
1955/**
1956 * skb_queue_is_first - check if skb is the first entry in the queue
1957 * @list: queue head
1958 * @skb: buffer
1959 *
1960 * Returns true if @skb is the first buffer on the list.
1961 */
1962static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1963 const struct sk_buff *skb)
1964{
1965 return skb->prev == (const struct sk_buff *) list;
1966}
1967
1968/**
1969 * skb_queue_next - return the next packet in the queue
1970 * @list: queue head
1971 * @skb: current buffer
1972 *
1973 * Return the next packet in @list after @skb. It is only valid to
1974 * call this if skb_queue_is_last() evaluates to false.
1975 */
1976static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1977 const struct sk_buff *skb)
1978{
1979 /* This BUG_ON may seem severe, but if we just return then we
1980 * are going to dereference garbage.
1981 */
1982 BUG_ON(skb_queue_is_last(list, skb));
1983 return skb->next;
1984}
1985
1986/**
1987 * skb_queue_prev - return the prev packet in the queue
1988 * @list: queue head
1989 * @skb: current buffer
1990 *
1991 * Return the prev packet in @list before @skb. It is only valid to
1992 * call this if skb_queue_is_first() evaluates to false.
1993 */
1994static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1995 const struct sk_buff *skb)
1996{
1997 /* This BUG_ON may seem severe, but if we just return then we
1998 * are going to dereference garbage.
1999 */
2000 BUG_ON(skb_queue_is_first(list, skb));
2001 return skb->prev;
2002}
2003
2004/**
2005 * skb_get - reference buffer
2006 * @skb: buffer to reference
2007 *
2008 * Makes another reference to a socket buffer and returns a pointer
2009 * to the buffer.
2010 */
2011static inline struct sk_buff *skb_get(struct sk_buff *skb)
2012{
2013 refcount_inc(r: &skb->users);
2014 return skb;
2015}
2016
2017/*
2018 * If users == 1, we are the only owner and can avoid redundant atomic changes.
2019 */
2020
2021/**
2022 * skb_cloned - is the buffer a clone
2023 * @skb: buffer to check
2024 *
2025 * Returns true if the buffer was generated with skb_clone() and is
2026 * one of multiple shared copies of the buffer. Cloned buffers are
2027 * shared data so must not be written to under normal circumstances.
2028 */
2029static inline int skb_cloned(const struct sk_buff *skb)
2030{
2031 return skb->cloned &&
2032 (atomic_read(v: &skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
2033}
2034
2035static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
2036{
2037 might_sleep_if(gfpflags_allow_blocking(pri));
2038
2039 if (skb_cloned(skb))
2040 return pskb_expand_head(skb, nhead: 0, ntail: 0, gfp_mask: pri);
2041
2042 return 0;
2043}
2044
2045/* This variant of skb_unclone() makes sure skb->truesize
2046 * and skb_end_offset() are not changed, whenever a new skb->head is needed.
2047 *
2048 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
2049 * when various debugging features are in place.
2050 */
2051int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
2052static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
2053{
2054 might_sleep_if(gfpflags_allow_blocking(pri));
2055
2056 if (skb_cloned(skb))
2057 return __skb_unclone_keeptruesize(skb, pri);
2058 return 0;
2059}
2060
2061/**
2062 * skb_header_cloned - is the header a clone
2063 * @skb: buffer to check
2064 *
2065 * Returns true if modifying the header part of the buffer requires
2066 * the data to be copied.
2067 */
2068static inline int skb_header_cloned(const struct sk_buff *skb)
2069{
2070 int dataref;
2071
2072 if (!skb->cloned)
2073 return 0;
2074
2075 dataref = atomic_read(v: &skb_shinfo(skb)->dataref);
2076 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
2077 return dataref != 1;
2078}
2079
2080static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
2081{
2082 might_sleep_if(gfpflags_allow_blocking(pri));
2083
2084 if (skb_header_cloned(skb))
2085 return pskb_expand_head(skb, nhead: 0, ntail: 0, gfp_mask: pri);
2086
2087 return 0;
2088}
2089
2090/**
2091 * __skb_header_release() - allow clones to use the headroom
2092 * @skb: buffer to operate on
2093 *
2094 * See "DOC: dataref and headerless skbs".
2095 */
2096static inline void __skb_header_release(struct sk_buff *skb)
2097{
2098 skb->nohdr = 1;
2099 atomic_set(v: &skb_shinfo(skb)->dataref, i: 1 + (1 << SKB_DATAREF_SHIFT));
2100}
2101
2102
2103/**
2104 * skb_shared - is the buffer shared
2105 * @skb: buffer to check
2106 *
2107 * Returns true if more than one person has a reference to this
2108 * buffer.
2109 */
2110static inline int skb_shared(const struct sk_buff *skb)
2111{
2112 return refcount_read(r: &skb->users) != 1;
2113}
2114
2115/**
2116 * skb_share_check - check if buffer is shared and if so clone it
2117 * @skb: buffer to check
2118 * @pri: priority for memory allocation
2119 *
2120 * If the buffer is shared the buffer is cloned and the old copy
2121 * drops a reference. A new clone with a single reference is returned.
2122 * If the buffer is not shared the original buffer is returned. When
2123 * being called from interrupt status or with spinlocks held pri must
2124 * be GFP_ATOMIC.
2125 *
2126 * NULL is returned on a memory allocation failure.
2127 */
2128static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
2129{
2130 might_sleep_if(gfpflags_allow_blocking(pri));
2131 if (skb_shared(skb)) {
2132 struct sk_buff *nskb = skb_clone(skb, priority: pri);
2133
2134 if (likely(nskb))
2135 consume_skb(skb);
2136 else
2137 kfree_skb(skb);
2138 skb = nskb;
2139 }
2140 return skb;
2141}
2142
2143/*
2144 * Copy shared buffers into a new sk_buff. We effectively do COW on
2145 * packets to handle cases where we have a local reader and forward
2146 * and a couple of other messy ones. The normal one is tcpdumping
2147 * a packet that's being forwarded.
2148 */
2149
2150/**
2151 * skb_unshare - make a copy of a shared buffer
2152 * @skb: buffer to check
2153 * @pri: priority for memory allocation
2154 *
2155 * If the socket buffer is a clone then this function creates a new
2156 * copy of the data, drops a reference count on the old copy and returns
2157 * the new copy with the reference count at 1. If the buffer is not a clone
2158 * the original buffer is returned. When called with a spinlock held or
2159 * from interrupt state @pri must be %GFP_ATOMIC
2160 *
2161 * %NULL is returned on a memory allocation failure.
2162 */
2163static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
2164 gfp_t pri)
2165{
2166 might_sleep_if(gfpflags_allow_blocking(pri));
2167 if (skb_cloned(skb)) {
2168 struct sk_buff *nskb = skb_copy(skb, priority: pri);
2169
2170 /* Free our shared copy */
2171 if (likely(nskb))
2172 consume_skb(skb);
2173 else
2174 kfree_skb(skb);
2175 skb = nskb;
2176 }
2177 return skb;
2178}
2179
2180/**
2181 * skb_peek - peek at the head of an &sk_buff_head
2182 * @list_: list to peek at
2183 *
2184 * Peek an &sk_buff. Unlike most other operations you _MUST_
2185 * be careful with this one. A peek leaves the buffer on the
2186 * list and someone else may run off with it. You must hold
2187 * the appropriate locks or have a private queue to do this.
2188 *
2189 * Returns %NULL for an empty list or a pointer to the head element.
2190 * The reference count is not incremented and the reference is therefore
2191 * volatile. Use with caution.
2192 */
2193static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
2194{
2195 struct sk_buff *skb = list_->next;
2196
2197 if (skb == (struct sk_buff *)list_)
2198 skb = NULL;
2199 return skb;
2200}
2201
2202/**
2203 * __skb_peek - peek at the head of a non-empty &sk_buff_head
2204 * @list_: list to peek at
2205 *
2206 * Like skb_peek(), but the caller knows that the list is not empty.
2207 */
2208static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
2209{
2210 return list_->next;
2211}
2212
2213/**
2214 * skb_peek_next - peek skb following the given one from a queue
2215 * @skb: skb to start from
2216 * @list_: list to peek at
2217 *
2218 * Returns %NULL when the end of the list is met or a pointer to the
2219 * next element. The reference count is not incremented and the
2220 * reference is therefore volatile. Use with caution.
2221 */
2222static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
2223 const struct sk_buff_head *list_)
2224{
2225 struct sk_buff *next = skb->next;
2226
2227 if (next == (struct sk_buff *)list_)
2228 next = NULL;
2229 return next;
2230}
2231
2232/**
2233 * skb_peek_tail - peek at the tail of an &sk_buff_head
2234 * @list_: list to peek at
2235 *
2236 * Peek an &sk_buff. Unlike most other operations you _MUST_
2237 * be careful with this one. A peek leaves the buffer on the
2238 * list and someone else may run off with it. You must hold
2239 * the appropriate locks or have a private queue to do this.
2240 *
2241 * Returns %NULL for an empty list or a pointer to the tail element.
2242 * The reference count is not incremented and the reference is therefore
2243 * volatile. Use with caution.
2244 */
2245static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
2246{
2247 struct sk_buff *skb = READ_ONCE(list_->prev);
2248
2249 if (skb == (struct sk_buff *)list_)
2250 skb = NULL;
2251 return skb;
2252
2253}
2254
2255/**
2256 * skb_queue_len - get queue length
2257 * @list_: list to measure
2258 *
2259 * Return the length of an &sk_buff queue.
2260 */
2261static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2262{
2263 return list_->qlen;
2264}
2265
2266/**
2267 * skb_queue_len_lockless - get queue length
2268 * @list_: list to measure
2269 *
2270 * Return the length of an &sk_buff queue.
2271 * This variant can be used in lockless contexts.
2272 */
2273static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2274{
2275 return READ_ONCE(list_->qlen);
2276}
2277
2278/**
2279 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2280 * @list: queue to initialize
2281 *
2282 * This initializes only the list and queue length aspects of
2283 * an sk_buff_head object. This allows to initialize the list
2284 * aspects of an sk_buff_head without reinitializing things like
2285 * the spinlock. It can also be used for on-stack sk_buff_head
2286 * objects where the spinlock is known to not be used.
2287 */
2288static inline void __skb_queue_head_init(struct sk_buff_head *list)
2289{
2290 list->prev = list->next = (struct sk_buff *)list;
2291 list->qlen = 0;
2292}
2293
2294/*
2295 * This function creates a split out lock class for each invocation;
2296 * this is needed for now since a whole lot of users of the skb-queue
2297 * infrastructure in drivers have different locking usage (in hardirq)
2298 * than the networking core (in softirq only). In the long run either the
2299 * network layer or drivers should need annotation to consolidate the
2300 * main types of usage into 3 classes.
2301 */
2302static inline void skb_queue_head_init(struct sk_buff_head *list)
2303{
2304 spin_lock_init(&list->lock);
2305 __skb_queue_head_init(list);
2306}
2307
2308static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2309 struct lock_class_key *class)
2310{
2311 skb_queue_head_init(list);
2312 lockdep_set_class(&list->lock, class);
2313}
2314
2315/*
2316 * Insert an sk_buff on a list.
2317 *
2318 * The "__skb_xxxx()" functions are the non-atomic ones that
2319 * can only be called with interrupts disabled.
2320 */
2321static inline void __skb_insert(struct sk_buff *newsk,
2322 struct sk_buff *prev, struct sk_buff *next,
2323 struct sk_buff_head *list)
2324{
2325 /* See skb_queue_empty_lockless() and skb_peek_tail()
2326 * for the opposite READ_ONCE()
2327 */
2328 WRITE_ONCE(newsk->next, next);
2329 WRITE_ONCE(newsk->prev, prev);
2330 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2331 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2332 WRITE_ONCE(list->qlen, list->qlen + 1);
2333}
2334
2335static inline void __skb_queue_splice(const struct sk_buff_head *list,
2336 struct sk_buff *prev,
2337 struct sk_buff *next)
2338{
2339 struct sk_buff *first = list->next;
2340 struct sk_buff *last = list->prev;
2341
2342 WRITE_ONCE(first->prev, prev);
2343 WRITE_ONCE(prev->next, first);
2344
2345 WRITE_ONCE(last->next, next);
2346 WRITE_ONCE(next->prev, last);
2347}
2348
2349/**
2350 * skb_queue_splice - join two skb lists, this is designed for stacks
2351 * @list: the new list to add
2352 * @head: the place to add it in the first list
2353 */
2354static inline void skb_queue_splice(const struct sk_buff_head *list,
2355 struct sk_buff_head *head)
2356{
2357 if (!skb_queue_empty(list)) {
2358 __skb_queue_splice(list, prev: (struct sk_buff *) head, next: head->next);
2359 head->qlen += list->qlen;
2360 }
2361}
2362
2363/**
2364 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2365 * @list: the new list to add
2366 * @head: the place to add it in the first list
2367 *
2368 * The list at @list is reinitialised
2369 */
2370static inline void skb_queue_splice_init(struct sk_buff_head *list,
2371 struct sk_buff_head *head)
2372{
2373 if (!skb_queue_empty(list)) {
2374 __skb_queue_splice(list, prev: (struct sk_buff *) head, next: head->next);
2375 head->qlen += list->qlen;
2376 __skb_queue_head_init(list);
2377 }
2378}
2379
2380/**
2381 * skb_queue_splice_tail - join two skb lists, each list being a queue
2382 * @list: the new list to add
2383 * @head: the place to add it in the first list
2384 */
2385static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2386 struct sk_buff_head *head)
2387{
2388 if (!skb_queue_empty(list)) {
2389 __skb_queue_splice(list, prev: head->prev, next: (struct sk_buff *) head);
2390 head->qlen += list->qlen;
2391 }
2392}
2393
2394/**
2395 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2396 * @list: the new list to add
2397 * @head: the place to add it in the first list
2398 *
2399 * Each of the lists is a queue.
2400 * The list at @list is reinitialised
2401 */
2402static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2403 struct sk_buff_head *head)
2404{
2405 if (!skb_queue_empty(list)) {
2406 __skb_queue_splice(list, prev: head->prev, next: (struct sk_buff *) head);
2407 head->qlen += list->qlen;
2408 __skb_queue_head_init(list);
2409 }
2410}
2411
2412/**
2413 * __skb_queue_after - queue a buffer at the list head
2414 * @list: list to use
2415 * @prev: place after this buffer
2416 * @newsk: buffer to queue
2417 *
2418 * Queue a buffer int the middle of a list. This function takes no locks
2419 * and you must therefore hold required locks before calling it.
2420 *
2421 * A buffer cannot be placed on two lists at the same time.
2422 */
2423static inline void __skb_queue_after(struct sk_buff_head *list,
2424 struct sk_buff *prev,
2425 struct sk_buff *newsk)
2426{
2427 __skb_insert(newsk, prev, next: ((struct sk_buff_list *)prev)->next, list);
2428}
2429
2430void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2431 struct sk_buff_head *list);
2432
2433static inline void __skb_queue_before(struct sk_buff_head *list,
2434 struct sk_buff *next,
2435 struct sk_buff *newsk)
2436{
2437 __skb_insert(newsk, prev: ((struct sk_buff_list *)next)->prev, next, list);
2438}
2439
2440/**
2441 * __skb_queue_head - queue a buffer at the list head
2442 * @list: list to use
2443 * @newsk: buffer to queue
2444 *
2445 * Queue a buffer at the start of a list. This function takes no locks
2446 * and you must therefore hold required locks before calling it.
2447 *
2448 * A buffer cannot be placed on two lists at the same time.
2449 */
2450static inline void __skb_queue_head(struct sk_buff_head *list,
2451 struct sk_buff *newsk)
2452{
2453 __skb_queue_after(list, prev: (struct sk_buff *)list, newsk);
2454}
2455void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2456
2457/**
2458 * __skb_queue_tail - queue a buffer at the list tail
2459 * @list: list to use
2460 * @newsk: buffer to queue
2461 *
2462 * Queue a buffer at the end of a list. This function takes no locks
2463 * and you must therefore hold required locks before calling it.
2464 *
2465 * A buffer cannot be placed on two lists at the same time.
2466 */
2467static inline void __skb_queue_tail(struct sk_buff_head *list,
2468 struct sk_buff *newsk)
2469{
2470 __skb_queue_before(list, next: (struct sk_buff *)list, newsk);
2471}
2472void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2473
2474/*
2475 * remove sk_buff from list. _Must_ be called atomically, and with
2476 * the list known..
2477 */
2478void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
2479static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2480{
2481 struct sk_buff *next, *prev;
2482
2483 WRITE_ONCE(list->qlen, list->qlen - 1);
2484 next = skb->next;
2485 prev = skb->prev;
2486 skb->next = skb->prev = NULL;
2487 WRITE_ONCE(next->prev, prev);
2488 WRITE_ONCE(prev->next, next);
2489}
2490
2491/**
2492 * __skb_dequeue - remove from the head of the queue
2493 * @list: list to dequeue from
2494 *
2495 * Remove the head of the list. This function does not take any locks
2496 * so must be used with appropriate locks held only. The head item is
2497 * returned or %NULL if the list is empty.
2498 */
2499static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2500{
2501 struct sk_buff *skb = skb_peek(list_: list);
2502 if (skb)
2503 __skb_unlink(skb, list);
2504 return skb;
2505}
2506struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2507
2508/**
2509 * __skb_dequeue_tail - remove from the tail of the queue
2510 * @list: list to dequeue from
2511 *
2512 * Remove the tail of the list. This function does not take any locks
2513 * so must be used with appropriate locks held only. The tail item is
2514 * returned or %NULL if the list is empty.
2515 */
2516static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2517{
2518 struct sk_buff *skb = skb_peek_tail(list_: list);
2519 if (skb)
2520 __skb_unlink(skb, list);
2521 return skb;
2522}
2523struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2524
2525
2526static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2527{
2528 return skb->data_len;
2529}
2530
2531static inline unsigned int skb_headlen(const struct sk_buff *skb)
2532{
2533 return skb->len - skb->data_len;
2534}
2535
2536static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2537{
2538 unsigned int i, len = 0;
2539
2540 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2541 len += skb_frag_size(frag: &skb_shinfo(skb)->frags[i]);
2542 return len;
2543}
2544
2545static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2546{
2547 return skb_headlen(skb) + __skb_pagelen(skb);
2548}
2549
2550static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag,
2551 netmem_ref netmem, int off,
2552 int size)
2553{
2554 frag->netmem = netmem;
2555 frag->offset = off;
2556 skb_frag_size_set(frag, size);
2557}
2558
2559static inline void skb_frag_fill_page_desc(skb_frag_t *frag,
2560 struct page *page,
2561 int off, int size)
2562{
2563 skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size);
2564}
2565
2566static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo,
2567 int i, netmem_ref netmem,
2568 int off, int size)
2569{
2570 skb_frag_t *frag = &shinfo->frags[i];
2571
2572 skb_frag_fill_netmem_desc(frag, netmem, off, size);
2573}
2574
2575static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2576 int i, struct page *page,
2577 int off, int size)
2578{
2579 __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off,
2580 size);
2581}
2582
2583/**
2584 * skb_len_add - adds a number to len fields of skb
2585 * @skb: buffer to add len to
2586 * @delta: number of bytes to add
2587 */
2588static inline void skb_len_add(struct sk_buff *skb, int delta)
2589{
2590 skb->len += delta;
2591 skb->data_len += delta;
2592 skb->truesize += delta;
2593}
2594
2595/**
2596 * __skb_fill_netmem_desc - initialise a fragment in an skb
2597 * @skb: buffer containing fragment to be initialised
2598 * @i: fragment index to initialise
2599 * @netmem: the netmem to use for this fragment
2600 * @off: the offset to the data with @page
2601 * @size: the length of the data
2602 *
2603 * Initialises the @i'th fragment of @skb to point to &size bytes at
2604 * offset @off within @page.
2605 *
2606 * Does not take any additional reference on the fragment.
2607 */
2608static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i,
2609 netmem_ref netmem, int off, int size)
2610{
2611 struct page *page;
2612
2613 __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size);
2614
2615 if (netmem_is_net_iov(netmem)) {
2616 skb->unreadable = true;
2617 return;
2618 }
2619
2620 page = netmem_to_page(netmem);
2621
2622 /* Propagate page pfmemalloc to the skb if we can. The problem is
2623 * that not all callers have unique ownership of the page but rely
2624 * on page_is_pfmemalloc doing the right thing(tm).
2625 */
2626 page = compound_head(page);
2627 if (page_is_pfmemalloc(page))
2628 skb->pfmemalloc = true;
2629}
2630
2631static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2632 struct page *page, int off, int size)
2633{
2634 __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2635}
2636
2637static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i,
2638 netmem_ref netmem, int off, int size)
2639{
2640 __skb_fill_netmem_desc(skb, i, netmem, off, size);
2641 skb_shinfo(skb)->nr_frags = i + 1;
2642}
2643
2644/**
2645 * skb_fill_page_desc - initialise a paged fragment in an skb
2646 * @skb: buffer containing fragment to be initialised
2647 * @i: paged fragment index to initialise
2648 * @page: the page to use for this fragment
2649 * @off: the offset to the data with @page
2650 * @size: the length of the data
2651 *
2652 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2653 * @skb to point to @size bytes at offset @off within @page. In
2654 * addition updates @skb such that @i is the last fragment.
2655 *
2656 * Does not take any additional reference on the fragment.
2657 */
2658static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2659 struct page *page, int off, int size)
2660{
2661 skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2662}
2663
2664/**
2665 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb
2666 * @skb: buffer containing fragment to be initialised
2667 * @i: paged fragment index to initialise
2668 * @page: the page to use for this fragment
2669 * @off: the offset to the data with @page
2670 * @size: the length of the data
2671 *
2672 * Variant of skb_fill_page_desc() which does not deal with
2673 * pfmemalloc, if page is not owned by us.
2674 */
2675static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i,
2676 struct page *page, int off,
2677 int size)
2678{
2679 struct skb_shared_info *shinfo = skb_shinfo(skb);
2680
2681 __skb_fill_page_desc_noacc(shinfo, i, page, off, size);
2682 shinfo->nr_frags = i + 1;
2683}
2684
2685void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem,
2686 int off, int size, unsigned int truesize);
2687
2688static inline void skb_add_rx_frag(struct sk_buff *skb, int i,
2689 struct page *page, int off, int size,
2690 unsigned int truesize)
2691{
2692 skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size,
2693 truesize);
2694}
2695
2696void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2697 unsigned int truesize);
2698
2699#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2700
2701#ifdef NET_SKBUFF_DATA_USES_OFFSET
2702static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2703{
2704 return skb->head + skb->tail;
2705}
2706
2707static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2708{
2709 skb->tail = skb->data - skb->head;
2710}
2711
2712static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2713{
2714 skb_reset_tail_pointer(skb);
2715 skb->tail += offset;
2716}
2717
2718#else /* NET_SKBUFF_DATA_USES_OFFSET */
2719static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2720{
2721 return skb->tail;
2722}
2723
2724static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2725{
2726 skb->tail = skb->data;
2727}
2728
2729static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2730{
2731 skb->tail = skb->data + offset;
2732}
2733
2734#endif /* NET_SKBUFF_DATA_USES_OFFSET */
2735
2736static inline void skb_assert_len(struct sk_buff *skb)
2737{
2738#ifdef CONFIG_DEBUG_NET
2739 if (WARN_ONCE(!skb->len, "%s\n", __func__))
2740 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2741#endif /* CONFIG_DEBUG_NET */
2742}
2743
2744#if defined(CONFIG_FAIL_SKB_REALLOC)
2745void skb_might_realloc(struct sk_buff *skb);
2746#else
2747static inline void skb_might_realloc(struct sk_buff *skb) {}
2748#endif
2749
2750/*
2751 * Add data to an sk_buff
2752 */
2753void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2754void *skb_put(struct sk_buff *skb, unsigned int len);
2755static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2756{
2757 void *tmp = skb_tail_pointer(skb);
2758 SKB_LINEAR_ASSERT(skb);
2759 skb->tail += len;
2760 skb->len += len;
2761 return tmp;
2762}
2763
2764static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2765{
2766 void *tmp = __skb_put(skb, len);
2767
2768 memset(s: tmp, c: 0, n: len);
2769 return tmp;
2770}
2771
2772static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2773 unsigned int len)
2774{
2775 void *tmp = __skb_put(skb, len);
2776
2777 memcpy(to: tmp, from: data, len);
2778 return tmp;
2779}
2780
2781static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2782{
2783 *(u8 *)__skb_put(skb, len: 1) = val;
2784}
2785
2786static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2787{
2788 void *tmp = skb_put(skb, len);
2789
2790 memset(s: tmp, c: 0, n: len);
2791
2792 return tmp;
2793}
2794
2795static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2796 unsigned int len)
2797{
2798 void *tmp = skb_put(skb, len);
2799
2800 memcpy(to: tmp, from: data, len);
2801
2802 return tmp;
2803}
2804
2805static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2806{
2807 *(u8 *)skb_put(skb, len: 1) = val;
2808}
2809
2810void *skb_push(struct sk_buff *skb, unsigned int len);
2811static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2812{
2813 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2814
2815 skb->data -= len;
2816 skb->len += len;
2817 return skb->data;
2818}
2819
2820void *skb_pull(struct sk_buff *skb, unsigned int len);
2821static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2822{
2823 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2824
2825 skb->len -= len;
2826 if (unlikely(skb->len < skb->data_len)) {
2827#if defined(CONFIG_DEBUG_NET)
2828 skb->len += len;
2829 pr_err("__skb_pull(len=%u)\n", len);
2830 skb_dump(KERN_ERR, skb, false);
2831#endif
2832 BUG();
2833 }
2834 return skb->data += len;
2835}
2836
2837static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2838{
2839 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2840}
2841
2842void *skb_pull_data(struct sk_buff *skb, size_t len);
2843
2844void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2845
2846static inline enum skb_drop_reason
2847pskb_may_pull_reason(struct sk_buff *skb, unsigned int len)
2848{
2849 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2850 skb_might_realloc(skb);
2851
2852 if (likely(len <= skb_headlen(skb)))
2853 return SKB_NOT_DROPPED_YET;
2854
2855 if (unlikely(len > skb->len))
2856 return SKB_DROP_REASON_PKT_TOO_SMALL;
2857
2858 if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb))))
2859 return SKB_DROP_REASON_NOMEM;
2860
2861 return SKB_NOT_DROPPED_YET;
2862}
2863
2864static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2865{
2866 return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET;
2867}
2868
2869static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2870{
2871 if (!pskb_may_pull(skb, len))
2872 return NULL;
2873
2874 skb->len -= len;
2875 return skb->data += len;
2876}
2877
2878void skb_condense(struct sk_buff *skb);
2879
2880/**
2881 * skb_headroom - bytes at buffer head
2882 * @skb: buffer to check
2883 *
2884 * Return the number of bytes of free space at the head of an &sk_buff.
2885 */
2886static inline unsigned int skb_headroom(const struct sk_buff *skb)
2887{
2888 return skb->data - skb->head;
2889}
2890
2891/**
2892 * skb_tailroom - bytes at buffer end
2893 * @skb: buffer to check
2894 *
2895 * Return the number of bytes of free space at the tail of an sk_buff
2896 */
2897static inline int skb_tailroom(const struct sk_buff *skb)
2898{
2899 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2900}
2901
2902/**
2903 * skb_availroom - bytes at buffer end
2904 * @skb: buffer to check
2905 *
2906 * Return the number of bytes of free space at the tail of an sk_buff
2907 * allocated by sk_stream_alloc()
2908 */
2909static inline int skb_availroom(const struct sk_buff *skb)
2910{
2911 if (skb_is_nonlinear(skb))
2912 return 0;
2913
2914 return skb->end - skb->tail - skb->reserved_tailroom;
2915}
2916
2917/**
2918 * skb_reserve - adjust headroom
2919 * @skb: buffer to alter
2920 * @len: bytes to move
2921 *
2922 * Increase the headroom of an empty &sk_buff by reducing the tail
2923 * room. This is only allowed for an empty buffer.
2924 */
2925static inline void skb_reserve(struct sk_buff *skb, int len)
2926{
2927 skb->data += len;
2928 skb->tail += len;
2929}
2930
2931/**
2932 * skb_tailroom_reserve - adjust reserved_tailroom
2933 * @skb: buffer to alter
2934 * @mtu: maximum amount of headlen permitted
2935 * @needed_tailroom: minimum amount of reserved_tailroom
2936 *
2937 * Set reserved_tailroom so that headlen can be as large as possible but
2938 * not larger than mtu and tailroom cannot be smaller than
2939 * needed_tailroom.
2940 * The required headroom should already have been reserved before using
2941 * this function.
2942 */
2943static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2944 unsigned int needed_tailroom)
2945{
2946 SKB_LINEAR_ASSERT(skb);
2947 if (mtu < skb_tailroom(skb) - needed_tailroom)
2948 /* use at most mtu */
2949 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2950 else
2951 /* use up to all available space */
2952 skb->reserved_tailroom = needed_tailroom;
2953}
2954
2955#define ENCAP_TYPE_ETHER 0
2956#define ENCAP_TYPE_IPPROTO 1
2957
2958static inline void skb_set_inner_protocol(struct sk_buff *skb,
2959 __be16 protocol)
2960{
2961 skb->inner_protocol = protocol;
2962 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2963}
2964
2965static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2966 __u8 ipproto)
2967{
2968 skb->inner_ipproto = ipproto;
2969 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2970}
2971
2972static inline void skb_reset_inner_headers(struct sk_buff *skb)
2973{
2974 skb->inner_mac_header = skb->mac_header;
2975 skb->inner_network_header = skb->network_header;
2976 skb->inner_transport_header = skb->transport_header;
2977}
2978
2979static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2980{
2981 return skb->mac_header != (typeof(skb->mac_header))~0U;
2982}
2983
2984static inline void skb_reset_mac_len(struct sk_buff *skb)
2985{
2986 if (!skb_mac_header_was_set(skb)) {
2987 DEBUG_NET_WARN_ON_ONCE(1);
2988 skb->mac_len = 0;
2989 } else {
2990 skb->mac_len = skb->network_header - skb->mac_header;
2991 }
2992}
2993
2994static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2995 *skb)
2996{
2997 return skb->head + skb->inner_transport_header;
2998}
2999
3000static inline int skb_inner_transport_offset(const struct sk_buff *skb)
3001{
3002 return skb_inner_transport_header(skb) - skb->data;
3003}
3004
3005static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
3006{
3007 long offset = skb->data - skb->head;
3008
3009 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_transport_header))offset);
3010 skb->inner_transport_header = offset;
3011}
3012
3013static inline void skb_set_inner_transport_header(struct sk_buff *skb,
3014 const int offset)
3015{
3016 skb_reset_inner_transport_header(skb);
3017 skb->inner_transport_header += offset;
3018}
3019
3020static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
3021{
3022 return skb->head + skb->inner_network_header;
3023}
3024
3025static inline void skb_reset_inner_network_header(struct sk_buff *skb)
3026{
3027 long offset = skb->data - skb->head;
3028
3029 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_network_header))offset);
3030 skb->inner_network_header = offset;
3031}
3032
3033static inline void skb_set_inner_network_header(struct sk_buff *skb,
3034 const int offset)
3035{
3036 skb_reset_inner_network_header(skb);
3037 skb->inner_network_header += offset;
3038}
3039
3040static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb)
3041{
3042 return skb->inner_network_header > 0;
3043}
3044
3045static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
3046{
3047 return skb->head + skb->inner_mac_header;
3048}
3049
3050static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
3051{
3052 long offset = skb->data - skb->head;
3053
3054 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_mac_header))offset);
3055 skb->inner_mac_header = offset;
3056}
3057
3058static inline void skb_set_inner_mac_header(struct sk_buff *skb,
3059 const int offset)
3060{
3061 skb_reset_inner_mac_header(skb);
3062 skb->inner_mac_header += offset;
3063}
3064static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
3065{
3066 return skb->transport_header != (typeof(skb->transport_header))~0U;
3067}
3068
3069static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
3070{
3071 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
3072 return skb->head + skb->transport_header;
3073}
3074
3075static inline void skb_reset_transport_header(struct sk_buff *skb)
3076{
3077 long offset = skb->data - skb->head;
3078
3079 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->transport_header))offset);
3080 skb->transport_header = offset;
3081}
3082
3083/**
3084 * skb_reset_transport_header_careful - conditionally reset transport header
3085 * @skb: buffer to alter
3086 *
3087 * Hardened version of skb_reset_transport_header().
3088 *
3089 * Returns: true if the operation was a success.
3090 */
3091static inline bool __must_check
3092skb_reset_transport_header_careful(struct sk_buff *skb)
3093{
3094 long offset = skb->data - skb->head;
3095
3096 if (unlikely(offset != (typeof(skb->transport_header))offset))
3097 return false;
3098
3099 if (unlikely(offset == (typeof(skb->transport_header))~0U))
3100 return false;
3101
3102 skb->transport_header = offset;
3103 return true;
3104}
3105
3106static inline void skb_set_transport_header(struct sk_buff *skb,
3107 const int offset)
3108{
3109 skb_reset_transport_header(skb);
3110 skb->transport_header += offset;
3111}
3112
3113static inline unsigned char *skb_network_header(const struct sk_buff *skb)
3114{
3115 return skb->head + skb->network_header;
3116}
3117
3118static inline void skb_reset_network_header(struct sk_buff *skb)
3119{
3120 long offset = skb->data - skb->head;
3121
3122 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->network_header))offset);
3123 skb->network_header = offset;
3124}
3125
3126static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
3127{
3128 skb_reset_network_header(skb);
3129 skb->network_header += offset;
3130}
3131
3132static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
3133{
3134 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
3135 return skb->head + skb->mac_header;
3136}
3137
3138static inline int skb_mac_offset(const struct sk_buff *skb)
3139{
3140 return skb_mac_header(skb) - skb->data;
3141}
3142
3143static inline u32 skb_mac_header_len(const struct sk_buff *skb)
3144{
3145 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
3146 return skb->network_header - skb->mac_header;
3147}
3148
3149static inline void skb_unset_mac_header(struct sk_buff *skb)
3150{
3151 skb->mac_header = (typeof(skb->mac_header))~0U;
3152}
3153
3154static inline void skb_reset_mac_header(struct sk_buff *skb)
3155{
3156 long offset = skb->data - skb->head;
3157
3158 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->mac_header))offset);
3159 skb->mac_header = offset;
3160}
3161
3162static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
3163{
3164 skb_reset_mac_header(skb);
3165 skb->mac_header += offset;
3166}
3167
3168static inline void skb_pop_mac_header(struct sk_buff *skb)
3169{
3170 skb->mac_header = skb->network_header;
3171}
3172
3173static inline void skb_probe_transport_header(struct sk_buff *skb)
3174{
3175 struct flow_keys_basic keys;
3176
3177 if (skb_transport_header_was_set(skb))
3178 return;
3179
3180 if (skb_flow_dissect_flow_keys_basic(NULL, skb, flow: &keys,
3181 NULL, proto: 0, nhoff: 0, hlen: 0, flags: 0))
3182 skb_set_transport_header(skb, offset: keys.control.thoff);
3183}
3184
3185static inline void skb_mac_header_rebuild(struct sk_buff *skb)
3186{
3187 if (skb_mac_header_was_set(skb)) {
3188 const unsigned char *old_mac = skb_mac_header(skb);
3189
3190 skb_set_mac_header(skb, offset: -skb->mac_len);
3191 memmove(dest: skb_mac_header(skb), src: old_mac, count: skb->mac_len);
3192 }
3193}
3194
3195/* Move the full mac header up to current network_header.
3196 * Leaves skb->data pointing at offset skb->mac_len into the mac_header.
3197 * Must be provided the complete mac header length.
3198 */
3199static inline void skb_mac_header_rebuild_full(struct sk_buff *skb, u32 full_mac_len)
3200{
3201 if (skb_mac_header_was_set(skb)) {
3202 const unsigned char *old_mac = skb_mac_header(skb);
3203
3204 skb_set_mac_header(skb, offset: -full_mac_len);
3205 memmove(dest: skb_mac_header(skb), src: old_mac, count: full_mac_len);
3206 __skb_push(skb, len: full_mac_len - skb->mac_len);
3207 }
3208}
3209
3210static inline int skb_checksum_start_offset(const struct sk_buff *skb)
3211{
3212 return skb->csum_start - skb_headroom(skb);
3213}
3214
3215static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
3216{
3217 return skb->head + skb->csum_start;
3218}
3219
3220static inline int skb_transport_offset(const struct sk_buff *skb)
3221{
3222 return skb_transport_header(skb) - skb->data;
3223}
3224
3225static inline u32 skb_network_header_len(const struct sk_buff *skb)
3226{
3227 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
3228 return skb->transport_header - skb->network_header;
3229}
3230
3231static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
3232{
3233 return skb->inner_transport_header - skb->inner_network_header;
3234}
3235
3236static inline int skb_network_offset(const struct sk_buff *skb)
3237{
3238 return skb_network_header(skb) - skb->data;
3239}
3240
3241static inline int skb_inner_network_offset(const struct sk_buff *skb)
3242{
3243 return skb_inner_network_header(skb) - skb->data;
3244}
3245
3246static inline enum skb_drop_reason
3247pskb_network_may_pull_reason(struct sk_buff *skb, unsigned int len)
3248{
3249 return pskb_may_pull_reason(skb, len: skb_network_offset(skb) + len);
3250}
3251
3252static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
3253{
3254 return pskb_network_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET;
3255}
3256
3257/*
3258 * CPUs often take a performance hit when accessing unaligned memory
3259 * locations. The actual performance hit varies, it can be small if the
3260 * hardware handles it or large if we have to take an exception and fix it
3261 * in software.
3262 *
3263 * Since an ethernet header is 14 bytes network drivers often end up with
3264 * the IP header at an unaligned offset. The IP header can be aligned by
3265 * shifting the start of the packet by 2 bytes. Drivers should do this
3266 * with:
3267 *
3268 * skb_reserve(skb, NET_IP_ALIGN);
3269 *
3270 * The downside to this alignment of the IP header is that the DMA is now
3271 * unaligned. On some architectures the cost of an unaligned DMA is high
3272 * and this cost outweighs the gains made by aligning the IP header.
3273 *
3274 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
3275 * to be overridden.
3276 */
3277#ifndef NET_IP_ALIGN
3278#define NET_IP_ALIGN 2
3279#endif
3280
3281/*
3282 * The networking layer reserves some headroom in skb data (via
3283 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
3284 * the header has to grow. In the default case, if the header has to grow
3285 * 32 bytes or less we avoid the reallocation.
3286 *
3287 * Unfortunately this headroom changes the DMA alignment of the resulting
3288 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
3289 * on some architectures. An architecture can override this value,
3290 * perhaps setting it to a cacheline in size (since that will maintain
3291 * cacheline alignment of the DMA). It must be a power of 2.
3292 *
3293 * Various parts of the networking layer expect at least 32 bytes of
3294 * headroom, you should not reduce this.
3295 *
3296 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
3297 * to reduce average number of cache lines per packet.
3298 * get_rps_cpu() for example only access one 64 bytes aligned block :
3299 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
3300 */
3301#ifndef NET_SKB_PAD
3302#define NET_SKB_PAD max(32, L1_CACHE_BYTES)
3303#endif
3304
3305int ___pskb_trim(struct sk_buff *skb, unsigned int len);
3306
3307static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
3308{
3309 if (WARN_ON(skb_is_nonlinear(skb)))
3310 return;
3311 skb->len = len;
3312 skb_set_tail_pointer(skb, offset: len);
3313}
3314
3315static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
3316{
3317 __skb_set_length(skb, len);
3318}
3319
3320void skb_trim(struct sk_buff *skb, unsigned int len);
3321
3322static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
3323{
3324 if (skb->data_len)
3325 return ___pskb_trim(skb, len);
3326 __skb_trim(skb, len);
3327 return 0;
3328}
3329
3330static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
3331{
3332 skb_might_realloc(skb);
3333 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
3334}
3335
3336/**
3337 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
3338 * @skb: buffer to alter
3339 * @len: new length
3340 *
3341 * This is identical to pskb_trim except that the caller knows that
3342 * the skb is not cloned so we should never get an error due to out-
3343 * of-memory.
3344 */
3345static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
3346{
3347 int err = pskb_trim(skb, len);
3348 BUG_ON(err);
3349}
3350
3351static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
3352{
3353 unsigned int diff = len - skb->len;
3354
3355 if (skb_tailroom(skb) < diff) {
3356 int ret = pskb_expand_head(skb, nhead: 0, ntail: diff - skb_tailroom(skb),
3357 GFP_ATOMIC);
3358 if (ret)
3359 return ret;
3360 }
3361 __skb_set_length(skb, len);
3362 return 0;
3363}
3364
3365/**
3366 * skb_orphan - orphan a buffer
3367 * @skb: buffer to orphan
3368 *
3369 * If a buffer currently has an owner then we call the owner's
3370 * destructor function and make the @skb unowned. The buffer continues
3371 * to exist but is no longer charged to its former owner.
3372 */
3373static inline void skb_orphan(struct sk_buff *skb)
3374{
3375 if (skb->destructor) {
3376 skb->destructor(skb);
3377 skb->destructor = NULL;
3378 skb->sk = NULL;
3379 } else {
3380 BUG_ON(skb->sk);
3381 }
3382}
3383
3384/**
3385 * skb_orphan_frags - orphan the frags contained in a buffer
3386 * @skb: buffer to orphan frags from
3387 * @gfp_mask: allocation mask for replacement pages
3388 *
3389 * For each frag in the SKB which needs a destructor (i.e. has an
3390 * owner) create a copy of that frag and release the original
3391 * page by calling the destructor.
3392 */
3393static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3394{
3395 if (likely(!skb_zcopy(skb)))
3396 return 0;
3397 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3398 return 0;
3399 return skb_copy_ubufs(skb, gfp_mask);
3400}
3401
3402/* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
3403static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3404{
3405 if (likely(!skb_zcopy(skb)))
3406 return 0;
3407 return skb_copy_ubufs(skb, gfp_mask);
3408}
3409
3410/**
3411 * __skb_queue_purge_reason - empty a list
3412 * @list: list to empty
3413 * @reason: drop reason
3414 *
3415 * Delete all buffers on an &sk_buff list. Each buffer is removed from
3416 * the list and one reference dropped. This function does not take the
3417 * list lock and the caller must hold the relevant locks to use it.
3418 */
3419static inline void __skb_queue_purge_reason(struct sk_buff_head *list,
3420 enum skb_drop_reason reason)
3421{
3422 struct sk_buff *skb;
3423
3424 while ((skb = __skb_dequeue(list)) != NULL)
3425 kfree_skb_reason(skb, reason);
3426}
3427
3428static inline void __skb_queue_purge(struct sk_buff_head *list)
3429{
3430 __skb_queue_purge_reason(list, reason: SKB_DROP_REASON_QUEUE_PURGE);
3431}
3432
3433void skb_queue_purge_reason(struct sk_buff_head *list,
3434 enum skb_drop_reason reason);
3435
3436static inline void skb_queue_purge(struct sk_buff_head *list)
3437{
3438 skb_queue_purge_reason(list, reason: SKB_DROP_REASON_QUEUE_PURGE);
3439}
3440
3441unsigned int skb_rbtree_purge(struct rb_root *root);
3442void skb_errqueue_purge(struct sk_buff_head *list);
3443
3444void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3445
3446/**
3447 * netdev_alloc_frag - allocate a page fragment
3448 * @fragsz: fragment size
3449 *
3450 * Allocates a frag from a page for receive buffer.
3451 * Uses GFP_ATOMIC allocations.
3452 */
3453static inline void *netdev_alloc_frag(unsigned int fragsz)
3454{
3455 return __netdev_alloc_frag_align(fragsz, align_mask: ~0u);
3456}
3457
3458static inline void *netdev_alloc_frag_align(unsigned int fragsz,
3459 unsigned int align)
3460{
3461 WARN_ON_ONCE(!is_power_of_2(align));
3462 return __netdev_alloc_frag_align(fragsz, align_mask: -align);
3463}
3464
3465struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
3466 gfp_t gfp_mask);
3467
3468/**
3469 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
3470 * @dev: network device to receive on
3471 * @length: length to allocate
3472 *
3473 * Allocate a new &sk_buff and assign it a usage count of one. The
3474 * buffer has unspecified headroom built in. Users should allocate
3475 * the headroom they think they need without accounting for the
3476 * built in space. The built in space is used for optimisations.
3477 *
3478 * %NULL is returned if there is no free memory. Although this function
3479 * allocates memory it can be called from an interrupt.
3480 */
3481static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
3482 unsigned int length)
3483{
3484 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3485}
3486
3487/* legacy helper around __netdev_alloc_skb() */
3488static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
3489 gfp_t gfp_mask)
3490{
3491 return __netdev_alloc_skb(NULL, length, gfp_mask);
3492}
3493
3494/* legacy helper around netdev_alloc_skb() */
3495static inline struct sk_buff *dev_alloc_skb(unsigned int length)
3496{
3497 return netdev_alloc_skb(NULL, length);
3498}
3499
3500
3501static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
3502 unsigned int length, gfp_t gfp)
3503{
3504 struct sk_buff *skb = __netdev_alloc_skb(dev, length: length + NET_IP_ALIGN, gfp_mask: gfp);
3505
3506 if (NET_IP_ALIGN && skb)
3507 skb_reserve(skb, NET_IP_ALIGN);
3508 return skb;
3509}
3510
3511static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
3512 unsigned int length)
3513{
3514 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3515}
3516
3517static inline void skb_free_frag(void *addr)
3518{
3519 page_frag_free(addr);
3520}
3521
3522void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3523
3524static inline void *napi_alloc_frag(unsigned int fragsz)
3525{
3526 return __napi_alloc_frag_align(fragsz, align_mask: ~0u);
3527}
3528
3529static inline void *napi_alloc_frag_align(unsigned int fragsz,
3530 unsigned int align)
3531{
3532 WARN_ON_ONCE(!is_power_of_2(align));
3533 return __napi_alloc_frag_align(fragsz, align_mask: -align);
3534}
3535
3536struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int length);
3537void napi_consume_skb(struct sk_buff *skb, int budget);
3538
3539void napi_skb_free_stolen_head(struct sk_buff *skb);
3540void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason);
3541
3542/**
3543 * __dev_alloc_pages - allocate page for network Rx
3544 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3545 * @order: size of the allocation
3546 *
3547 * Allocate a new page.
3548 *
3549 * %NULL is returned if there is no free memory.
3550*/
3551static inline struct page *__dev_alloc_pages_noprof(gfp_t gfp_mask,
3552 unsigned int order)
3553{
3554 /* This piece of code contains several assumptions.
3555 * 1. This is for device Rx, therefore a cold page is preferred.
3556 * 2. The expectation is the user wants a compound page.
3557 * 3. If requesting a order 0 page it will not be compound
3558 * due to the check to see if order has a value in prep_new_page
3559 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3560 * code in gfp_to_alloc_flags that should be enforcing this.
3561 */
3562 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
3563
3564 return alloc_pages_node_noprof(NUMA_NO_NODE, gfp_mask, order);
3565}
3566#define __dev_alloc_pages(...) alloc_hooks(__dev_alloc_pages_noprof(__VA_ARGS__))
3567
3568/*
3569 * This specialized allocator has to be a macro for its allocations to be
3570 * accounted separately (to have a separate alloc_tag).
3571 */
3572#define dev_alloc_pages(_order) __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, _order)
3573
3574/**
3575 * __dev_alloc_page - allocate a page for network Rx
3576 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3577 *
3578 * Allocate a new page.
3579 *
3580 * %NULL is returned if there is no free memory.
3581 */
3582static inline struct page *__dev_alloc_page_noprof(gfp_t gfp_mask)
3583{
3584 return __dev_alloc_pages_noprof(gfp_mask, order: 0);
3585}
3586#define __dev_alloc_page(...) alloc_hooks(__dev_alloc_page_noprof(__VA_ARGS__))
3587
3588/*
3589 * This specialized allocator has to be a macro for its allocations to be
3590 * accounted separately (to have a separate alloc_tag).
3591 */
3592#define dev_alloc_page() dev_alloc_pages(0)
3593
3594/**
3595 * dev_page_is_reusable - check whether a page can be reused for network Rx
3596 * @page: the page to test
3597 *
3598 * A page shouldn't be considered for reusing/recycling if it was allocated
3599 * under memory pressure or at a distant memory node.
3600 *
3601 * Returns: false if this page should be returned to page allocator, true
3602 * otherwise.
3603 */
3604static inline bool dev_page_is_reusable(const struct page *page)
3605{
3606 return likely(page_to_nid(page) == numa_mem_id() &&
3607 !page_is_pfmemalloc(page));
3608}
3609
3610/**
3611 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3612 * @page: The page that was allocated from skb_alloc_page
3613 * @skb: The skb that may need pfmemalloc set
3614 */
3615static inline void skb_propagate_pfmemalloc(const struct page *page,
3616 struct sk_buff *skb)
3617{
3618 if (page_is_pfmemalloc(page))
3619 skb->pfmemalloc = true;
3620}
3621
3622/**
3623 * skb_frag_off() - Returns the offset of a skb fragment
3624 * @frag: the paged fragment
3625 */
3626static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3627{
3628 return frag->offset;
3629}
3630
3631/**
3632 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3633 * @frag: skb fragment
3634 * @delta: value to add
3635 */
3636static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3637{
3638 frag->offset += delta;
3639}
3640
3641/**
3642 * skb_frag_off_set() - Sets the offset of a skb fragment
3643 * @frag: skb fragment
3644 * @offset: offset of fragment
3645 */
3646static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3647{
3648 frag->offset = offset;
3649}
3650
3651/**
3652 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3653 * @fragto: skb fragment where offset is set
3654 * @fragfrom: skb fragment offset is copied from
3655 */
3656static inline void skb_frag_off_copy(skb_frag_t *fragto,
3657 const skb_frag_t *fragfrom)
3658{
3659 fragto->offset = fragfrom->offset;
3660}
3661
3662/* Return: true if the skb_frag contains a net_iov. */
3663static inline bool skb_frag_is_net_iov(const skb_frag_t *frag)
3664{
3665 return netmem_is_net_iov(netmem: frag->netmem);
3666}
3667
3668/**
3669 * skb_frag_net_iov - retrieve the net_iov referred to by fragment
3670 * @frag: the fragment
3671 *
3672 * Return: the &struct net_iov associated with @frag. Returns NULL if this
3673 * frag has no associated net_iov.
3674 */
3675static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag)
3676{
3677 if (!skb_frag_is_net_iov(frag))
3678 return NULL;
3679
3680 return netmem_to_net_iov(netmem: frag->netmem);
3681}
3682
3683/**
3684 * skb_frag_page - retrieve the page referred to by a paged fragment
3685 * @frag: the paged fragment
3686 *
3687 * Return: the &struct page associated with @frag. Returns NULL if this frag
3688 * has no associated page.
3689 */
3690static inline struct page *skb_frag_page(const skb_frag_t *frag)
3691{
3692 if (skb_frag_is_net_iov(frag))
3693 return NULL;
3694
3695 return netmem_to_page(netmem: frag->netmem);
3696}
3697
3698/**
3699 * skb_frag_netmem - retrieve the netmem referred to by a fragment
3700 * @frag: the fragment
3701 *
3702 * Return: the &netmem_ref associated with @frag.
3703 */
3704static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag)
3705{
3706 return frag->netmem;
3707}
3708
3709int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
3710 unsigned int headroom);
3711int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
3712 const struct bpf_prog *prog);
3713
3714/**
3715 * skb_frag_address - gets the address of the data contained in a paged fragment
3716 * @frag: the paged fragment buffer
3717 *
3718 * Returns: the address of the data within @frag. The page must already
3719 * be mapped.
3720 */
3721static inline void *skb_frag_address(const skb_frag_t *frag)
3722{
3723 if (!skb_frag_page(frag))
3724 return NULL;
3725
3726 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3727}
3728
3729/**
3730 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3731 * @frag: the paged fragment buffer
3732 *
3733 * Returns: the address of the data within @frag. Checks that the page
3734 * is mapped and returns %NULL otherwise.
3735 */
3736static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3737{
3738 struct page *page = skb_frag_page(frag);
3739 void *ptr;
3740
3741 if (!page)
3742 return NULL;
3743
3744 ptr = page_address(page);
3745 if (unlikely(!ptr))
3746 return NULL;
3747
3748 return ptr + skb_frag_off(frag);
3749}
3750
3751/**
3752 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3753 * @fragto: skb fragment where page is set
3754 * @fragfrom: skb fragment page is copied from
3755 */
3756static inline void skb_frag_page_copy(skb_frag_t *fragto,
3757 const skb_frag_t *fragfrom)
3758{
3759 fragto->netmem = fragfrom->netmem;
3760}
3761
3762bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3763
3764/**
3765 * __skb_frag_dma_map - maps a paged fragment via the DMA API
3766 * @dev: the device to map the fragment to
3767 * @frag: the paged fragment to map
3768 * @offset: the offset within the fragment (starting at the
3769 * fragment's own offset)
3770 * @size: the number of bytes to map
3771 * @dir: the direction of the mapping (``PCI_DMA_*``)
3772 *
3773 * Maps the page associated with @frag to @device.
3774 */
3775static inline dma_addr_t __skb_frag_dma_map(struct device *dev,
3776 const skb_frag_t *frag,
3777 size_t offset, size_t size,
3778 enum dma_data_direction dir)
3779{
3780 if (skb_frag_is_net_iov(frag)) {
3781 return netmem_to_net_iov(netmem: frag->netmem)->dma_addr + offset +
3782 frag->offset;
3783 }
3784 return dma_map_page(dev, skb_frag_page(frag),
3785 skb_frag_off(frag) + offset, size, dir);
3786}
3787
3788#define skb_frag_dma_map(dev, frag, ...) \
3789 CONCATENATE(_skb_frag_dma_map, \
3790 COUNT_ARGS(__VA_ARGS__))(dev, frag, ##__VA_ARGS__)
3791
3792#define __skb_frag_dma_map1(dev, frag, offset, uf, uo) ({ \
3793 const skb_frag_t *uf = (frag); \
3794 size_t uo = (offset); \
3795 \
3796 __skb_frag_dma_map(dev, uf, uo, skb_frag_size(uf) - uo, \
3797 DMA_TO_DEVICE); \
3798})
3799#define _skb_frag_dma_map1(dev, frag, offset) \
3800 __skb_frag_dma_map1(dev, frag, offset, __UNIQUE_ID(frag_), \
3801 __UNIQUE_ID(offset_))
3802#define _skb_frag_dma_map0(dev, frag) \
3803 _skb_frag_dma_map1(dev, frag, 0)
3804#define _skb_frag_dma_map2(dev, frag, offset, size) \
3805 __skb_frag_dma_map(dev, frag, offset, size, DMA_TO_DEVICE)
3806#define _skb_frag_dma_map3(dev, frag, offset, size, dir) \
3807 __skb_frag_dma_map(dev, frag, offset, size, dir)
3808
3809static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3810 gfp_t gfp_mask)
3811{
3812 return __pskb_copy(skb, headroom: skb_headroom(skb), gfp_mask);
3813}
3814
3815
3816static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3817 gfp_t gfp_mask)
3818{
3819 return __pskb_copy_fclone(skb, headroom: skb_headroom(skb), gfp_mask, fclone: true);
3820}
3821
3822
3823/**
3824 * skb_clone_writable - is the header of a clone writable
3825 * @skb: buffer to check
3826 * @len: length up to which to write
3827 *
3828 * Returns true if modifying the header part of the cloned buffer
3829 * does not requires the data to be copied.
3830 */
3831static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3832{
3833 return !skb_header_cloned(skb) &&
3834 skb_headroom(skb) + len <= skb->hdr_len;
3835}
3836
3837static inline int skb_try_make_writable(struct sk_buff *skb,
3838 unsigned int write_len)
3839{
3840 return skb_cloned(skb) && !skb_clone_writable(skb, len: write_len) &&
3841 pskb_expand_head(skb, nhead: 0, ntail: 0, GFP_ATOMIC);
3842}
3843
3844static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3845 int cloned)
3846{
3847 int delta = 0;
3848
3849 if (headroom > skb_headroom(skb))
3850 delta = headroom - skb_headroom(skb);
3851
3852 if (delta || cloned)
3853 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), ntail: 0,
3854 GFP_ATOMIC);
3855 return 0;
3856}
3857
3858/**
3859 * skb_cow - copy header of skb when it is required
3860 * @skb: buffer to cow
3861 * @headroom: needed headroom
3862 *
3863 * If the skb passed lacks sufficient headroom or its data part
3864 * is shared, data is reallocated. If reallocation fails, an error
3865 * is returned and original skb is not changed.
3866 *
3867 * The result is skb with writable area skb->head...skb->tail
3868 * and at least @headroom of space at head.
3869 */
3870static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3871{
3872 return __skb_cow(skb, headroom, cloned: skb_cloned(skb));
3873}
3874
3875/**
3876 * skb_cow_head - skb_cow but only making the head writable
3877 * @skb: buffer to cow
3878 * @headroom: needed headroom
3879 *
3880 * This function is identical to skb_cow except that we replace the
3881 * skb_cloned check by skb_header_cloned. It should be used when
3882 * you only need to push on some header and do not need to modify
3883 * the data.
3884 */
3885static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3886{
3887 return __skb_cow(skb, headroom, cloned: skb_header_cloned(skb));
3888}
3889
3890/**
3891 * skb_padto - pad an skbuff up to a minimal size
3892 * @skb: buffer to pad
3893 * @len: minimal length
3894 *
3895 * Pads up a buffer to ensure the trailing bytes exist and are
3896 * blanked. If the buffer already contains sufficient data it
3897 * is untouched. Otherwise it is extended. Returns zero on
3898 * success. The skb is freed on error.
3899 */
3900static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3901{
3902 unsigned int size = skb->len;
3903 if (likely(size >= len))
3904 return 0;
3905 return skb_pad(skb, pad: len - size);
3906}
3907
3908/**
3909 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3910 * @skb: buffer to pad
3911 * @len: minimal length
3912 * @free_on_error: free buffer on error
3913 *
3914 * Pads up a buffer to ensure the trailing bytes exist and are
3915 * blanked. If the buffer already contains sufficient data it
3916 * is untouched. Otherwise it is extended. Returns zero on
3917 * success. The skb is freed on error if @free_on_error is true.
3918 */
3919static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3920 unsigned int len,
3921 bool free_on_error)
3922{
3923 unsigned int size = skb->len;
3924
3925 if (unlikely(size < len)) {
3926 len -= size;
3927 if (__skb_pad(skb, pad: len, free_on_error))
3928 return -ENOMEM;
3929 __skb_put(skb, len);
3930 }
3931 return 0;
3932}
3933
3934/**
3935 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3936 * @skb: buffer to pad
3937 * @len: minimal length
3938 *
3939 * Pads up a buffer to ensure the trailing bytes exist and are
3940 * blanked. If the buffer already contains sufficient data it
3941 * is untouched. Otherwise it is extended. Returns zero on
3942 * success. The skb is freed on error.
3943 */
3944static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3945{
3946 return __skb_put_padto(skb, len, free_on_error: true);
3947}
3948
3949bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i)
3950 __must_check;
3951
3952static inline bool skb_can_coalesce_netmem(struct sk_buff *skb, int i,
3953 netmem_ref netmem, int off)
3954{
3955 if (skb_zcopy(skb))
3956 return false;
3957 if (i) {
3958 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3959
3960 return netmem == skb_frag_netmem(frag) &&
3961 off == skb_frag_off(frag) + skb_frag_size(frag);
3962 }
3963 return false;
3964}
3965
3966static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3967 const struct page *page, int off)
3968{
3969 return skb_can_coalesce_netmem(skb, i, page_to_netmem(page), off);
3970}
3971
3972static inline int __skb_linearize(struct sk_buff *skb)
3973{
3974 return __pskb_pull_tail(skb, delta: skb->data_len) ? 0 : -ENOMEM;
3975}
3976
3977/**
3978 * skb_linearize - convert paged skb to linear one
3979 * @skb: buffer to linarize
3980 *
3981 * If there is no free memory -ENOMEM is returned, otherwise zero
3982 * is returned and the old skb data released.
3983 */
3984static inline int skb_linearize(struct sk_buff *skb)
3985{
3986 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3987}
3988
3989/**
3990 * skb_has_shared_frag - can any frag be overwritten
3991 * @skb: buffer to test
3992 *
3993 * Return: true if the skb has at least one frag that might be modified
3994 * by an external entity (as in vmsplice()/sendfile())
3995 */
3996static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3997{
3998 return skb_is_nonlinear(skb) &&
3999 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
4000}
4001
4002/**
4003 * skb_linearize_cow - make sure skb is linear and writable
4004 * @skb: buffer to process
4005 *
4006 * If there is no free memory -ENOMEM is returned, otherwise zero
4007 * is returned and the old skb data released.
4008 */
4009static inline int skb_linearize_cow(struct sk_buff *skb)
4010{
4011 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
4012 __skb_linearize(skb) : 0;
4013}
4014
4015static __always_inline void
4016__skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
4017 unsigned int off)
4018{
4019 if (skb->ip_summed == CHECKSUM_COMPLETE)
4020 skb->csum = csum_block_sub(csum: skb->csum,
4021 csum2: csum_partial(buff: start, len, sum: 0), offset: off);
4022 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
4023 skb_checksum_start_offset(skb) < 0)
4024 skb->ip_summed = CHECKSUM_NONE;
4025}
4026
4027/**
4028 * skb_postpull_rcsum - update checksum for received skb after pull
4029 * @skb: buffer to update
4030 * @start: start of data before pull
4031 * @len: length of data pulled
4032 *
4033 * After doing a pull on a received packet, you need to call this to
4034 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
4035 * CHECKSUM_NONE so that it can be recomputed from scratch.
4036 */
4037static inline void skb_postpull_rcsum(struct sk_buff *skb,
4038 const void *start, unsigned int len)
4039{
4040 if (skb->ip_summed == CHECKSUM_COMPLETE)
4041 skb->csum = wsum_negate(val: csum_partial(buff: start, len,
4042 sum: wsum_negate(val: skb->csum)));
4043 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
4044 skb_checksum_start_offset(skb) < 0)
4045 skb->ip_summed = CHECKSUM_NONE;
4046}
4047
4048static __always_inline void
4049__skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
4050 unsigned int off)
4051{
4052 if (skb->ip_summed == CHECKSUM_COMPLETE)
4053 skb->csum = csum_block_add(csum: skb->csum,
4054 csum2: csum_partial(buff: start, len, sum: 0), offset: off);
4055}
4056
4057/**
4058 * skb_postpush_rcsum - update checksum for received skb after push
4059 * @skb: buffer to update
4060 * @start: start of data after push
4061 * @len: length of data pushed
4062 *
4063 * After doing a push on a received packet, you need to call this to
4064 * update the CHECKSUM_COMPLETE checksum.
4065 */
4066static inline void skb_postpush_rcsum(struct sk_buff *skb,
4067 const void *start, unsigned int len)
4068{
4069 __skb_postpush_rcsum(skb, start, len, off: 0);
4070}
4071
4072void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
4073
4074/**
4075 * skb_push_rcsum - push skb and update receive checksum
4076 * @skb: buffer to update
4077 * @len: length of data pulled
4078 *
4079 * This function performs an skb_push on the packet and updates
4080 * the CHECKSUM_COMPLETE checksum. It should be used on
4081 * receive path processing instead of skb_push unless you know
4082 * that the checksum difference is zero (e.g., a valid IP header)
4083 * or you are setting ip_summed to CHECKSUM_NONE.
4084 */
4085static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
4086{
4087 skb_push(skb, len);
4088 skb_postpush_rcsum(skb, start: skb->data, len);
4089 return skb->data;
4090}
4091
4092int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
4093/**
4094 * pskb_trim_rcsum - trim received skb and update checksum
4095 * @skb: buffer to trim
4096 * @len: new length
4097 *
4098 * This is exactly the same as pskb_trim except that it ensures the
4099 * checksum of received packets are still valid after the operation.
4100 * It can change skb pointers.
4101 */
4102
4103static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
4104{
4105 skb_might_realloc(skb);
4106 if (likely(len >= skb->len))
4107 return 0;
4108 return pskb_trim_rcsum_slow(skb, len);
4109}
4110
4111static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
4112{
4113 if (skb->ip_summed == CHECKSUM_COMPLETE)
4114 skb->ip_summed = CHECKSUM_NONE;
4115 __skb_trim(skb, len);
4116 return 0;
4117}
4118
4119static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
4120{
4121 if (skb->ip_summed == CHECKSUM_COMPLETE)
4122 skb->ip_summed = CHECKSUM_NONE;
4123 return __skb_grow(skb, len);
4124}
4125
4126#define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
4127#define skb_rb_first(root) rb_to_skb(rb_first(root))
4128#define skb_rb_last(root) rb_to_skb(rb_last(root))
4129#define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
4130#define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
4131
4132#define skb_queue_walk(queue, skb) \
4133 for (skb = (queue)->next; \
4134 skb != (struct sk_buff *)(queue); \
4135 skb = skb->next)
4136
4137#define skb_queue_walk_safe(queue, skb, tmp) \
4138 for (skb = (queue)->next, tmp = skb->next; \
4139 skb != (struct sk_buff *)(queue); \
4140 skb = tmp, tmp = skb->next)
4141
4142#define skb_queue_walk_from(queue, skb) \
4143 for (; skb != (struct sk_buff *)(queue); \
4144 skb = skb->next)
4145
4146#define skb_rbtree_walk(skb, root) \
4147 for (skb = skb_rb_first(root); skb != NULL; \
4148 skb = skb_rb_next(skb))
4149
4150#define skb_rbtree_walk_from(skb) \
4151 for (; skb != NULL; \
4152 skb = skb_rb_next(skb))
4153
4154#define skb_rbtree_walk_from_safe(skb, tmp) \
4155 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
4156 skb = tmp)
4157
4158#define skb_queue_walk_from_safe(queue, skb, tmp) \
4159 for (tmp = skb->next; \
4160 skb != (struct sk_buff *)(queue); \
4161 skb = tmp, tmp = skb->next)
4162
4163#define skb_queue_reverse_walk(queue, skb) \
4164 for (skb = (queue)->prev; \
4165 skb != (struct sk_buff *)(queue); \
4166 skb = skb->prev)
4167
4168#define skb_queue_reverse_walk_safe(queue, skb, tmp) \
4169 for (skb = (queue)->prev, tmp = skb->prev; \
4170 skb != (struct sk_buff *)(queue); \
4171 skb = tmp, tmp = skb->prev)
4172
4173#define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
4174 for (tmp = skb->prev; \
4175 skb != (struct sk_buff *)(queue); \
4176 skb = tmp, tmp = skb->prev)
4177
4178static inline bool skb_has_frag_list(const struct sk_buff *skb)
4179{
4180 return skb_shinfo(skb)->frag_list != NULL;
4181}
4182
4183static inline void skb_frag_list_init(struct sk_buff *skb)
4184{
4185 skb_shinfo(skb)->frag_list = NULL;
4186}
4187
4188#define skb_walk_frags(skb, iter) \
4189 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
4190
4191
4192int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
4193 int *err, long *timeo_p,
4194 const struct sk_buff *skb);
4195struct sk_buff *__skb_try_recv_from_queue(struct sk_buff_head *queue,
4196 unsigned int flags,
4197 int *off, int *err,
4198 struct sk_buff **last);
4199struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
4200 struct sk_buff_head *queue,
4201 unsigned int flags, int *off, int *err,
4202 struct sk_buff **last);
4203struct sk_buff *__skb_recv_datagram(struct sock *sk,
4204 struct sk_buff_head *sk_queue,
4205 unsigned int flags, int *off, int *err);
4206struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
4207__poll_t datagram_poll(struct file *file, struct socket *sock,
4208 struct poll_table_struct *wait);
4209int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
4210 struct iov_iter *to, int size);
4211static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
4212 struct msghdr *msg, int size)
4213{
4214 return skb_copy_datagram_iter(from, offset, to: &msg->msg_iter, size);
4215}
4216int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
4217 struct msghdr *msg);
4218int skb_copy_and_crc32c_datagram_iter(const struct sk_buff *skb, int offset,
4219 struct iov_iter *to, int len, u32 *crcp);
4220int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
4221 struct iov_iter *from, int len);
4222int skb_copy_datagram_from_iter_full(struct sk_buff *skb, int offset,
4223 struct iov_iter *from, int len);
4224int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
4225void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
4226int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
4227int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
4228int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
4229__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
4230 int len);
4231int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
4232 struct pipe_inode_info *pipe, unsigned int len,
4233 unsigned int flags);
4234int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
4235 int len);
4236int skb_send_sock_locked_with_flags(struct sock *sk, struct sk_buff *skb,
4237 int offset, int len, int flags);
4238int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
4239void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
4240unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
4241int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
4242 int len, int hlen);
4243void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
4244int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
4245void skb_scrub_packet(struct sk_buff *skb, bool xnet);
4246struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
4247struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
4248 unsigned int offset);
4249struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
4250int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
4251int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev);
4252int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
4253int skb_vlan_pop(struct sk_buff *skb);
4254int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
4255int skb_eth_pop(struct sk_buff *skb);
4256int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
4257 const unsigned char *src);
4258int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
4259 int mac_len, bool ethernet);
4260int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
4261 bool ethernet);
4262int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
4263int skb_mpls_dec_ttl(struct sk_buff *skb);
4264struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
4265 gfp_t gfp);
4266
4267static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
4268{
4269 return copy_from_iter_full(addr: data, bytes: len, i: &msg->msg_iter) ? 0 : -EFAULT;
4270}
4271
4272static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
4273{
4274 return copy_to_iter(addr: data, bytes: len, i: &msg->msg_iter) == len ? 0 : -EFAULT;
4275}
4276
4277__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
4278 __wsum csum);
4279u32 skb_crc32c(const struct sk_buff *skb, int offset, int len, u32 crc);
4280
4281static inline void * __must_check
4282__skb_header_pointer(const struct sk_buff *skb, int offset, int len,
4283 const void *data, int hlen, void *buffer)
4284{
4285 if (likely(hlen - offset >= len))
4286 return (void *)data + offset;
4287
4288 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
4289 return NULL;
4290
4291 return buffer;
4292}
4293
4294static inline void * __must_check
4295skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
4296{
4297 return __skb_header_pointer(skb, offset, len, data: skb->data,
4298 hlen: skb_headlen(skb), buffer);
4299}
4300
4301static inline void * __must_check
4302skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len)
4303{
4304 if (likely(skb_headlen(skb) - offset >= len))
4305 return skb->data + offset;
4306 return NULL;
4307}
4308
4309/**
4310 * skb_needs_linearize - check if we need to linearize a given skb
4311 * depending on the given device features.
4312 * @skb: socket buffer to check
4313 * @features: net device features
4314 *
4315 * Returns true if either:
4316 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
4317 * 2. skb is fragmented and the device does not support SG.
4318 */
4319static inline bool skb_needs_linearize(struct sk_buff *skb,
4320 netdev_features_t features)
4321{
4322 return skb_is_nonlinear(skb) &&
4323 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
4324 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
4325}
4326
4327static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
4328 void *to,
4329 const unsigned int len)
4330{
4331 memcpy(to, from: skb->data, len);
4332}
4333
4334static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4335 const int offset, void *to,
4336 const unsigned int len)
4337{
4338 memcpy(to, from: skb->data + offset, len);
4339}
4340
4341static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4342 const void *from,
4343 const unsigned int len)
4344{
4345 memcpy(to: skb->data, from, len);
4346}
4347
4348static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4349 const int offset,
4350 const void *from,
4351 const unsigned int len)
4352{
4353 memcpy(to: skb->data + offset, from, len);
4354}
4355
4356void skb_init(void);
4357
4358static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4359{
4360 return skb->tstamp;
4361}
4362
4363/**
4364 * skb_get_timestamp - get timestamp from a skb
4365 * @skb: skb to get stamp from
4366 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
4367 *
4368 * Timestamps are stored in the skb as offsets to a base timestamp.
4369 * This function converts the offset back to a struct timeval and stores
4370 * it in stamp.
4371 */
4372static inline void skb_get_timestamp(const struct sk_buff *skb,
4373 struct __kernel_old_timeval *stamp)
4374{
4375 *stamp = ns_to_kernel_old_timeval(nsec: skb->tstamp);
4376}
4377
4378static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4379 struct __kernel_sock_timeval *stamp)
4380{
4381 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4382
4383 stamp->tv_sec = ts.tv_sec;
4384 stamp->tv_usec = ts.tv_nsec / 1000;
4385}
4386
4387static inline void skb_get_timestampns(const struct sk_buff *skb,
4388 struct __kernel_old_timespec *stamp)
4389{
4390 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4391
4392 stamp->tv_sec = ts.tv_sec;
4393 stamp->tv_nsec = ts.tv_nsec;
4394}
4395
4396static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4397 struct __kernel_timespec *stamp)
4398{
4399 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4400
4401 stamp->tv_sec = ts.tv_sec;
4402 stamp->tv_nsec = ts.tv_nsec;
4403}
4404
4405static inline void __net_timestamp(struct sk_buff *skb)
4406{
4407 skb->tstamp = ktime_get_real();
4408 skb->tstamp_type = SKB_CLOCK_REALTIME;
4409}
4410
4411static inline ktime_t net_timedelta(ktime_t t)
4412{
4413 return ktime_sub(ktime_get_real(), t);
4414}
4415
4416static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4417 u8 tstamp_type)
4418{
4419 skb->tstamp = kt;
4420
4421 if (kt)
4422 skb->tstamp_type = tstamp_type;
4423 else
4424 skb->tstamp_type = SKB_CLOCK_REALTIME;
4425}
4426
4427static inline void skb_set_delivery_type_by_clockid(struct sk_buff *skb,
4428 ktime_t kt, clockid_t clockid)
4429{
4430 u8 tstamp_type = SKB_CLOCK_REALTIME;
4431
4432 switch (clockid) {
4433 case CLOCK_REALTIME:
4434 break;
4435 case CLOCK_MONOTONIC:
4436 tstamp_type = SKB_CLOCK_MONOTONIC;
4437 break;
4438 case CLOCK_TAI:
4439 tstamp_type = SKB_CLOCK_TAI;
4440 break;
4441 default:
4442 WARN_ON_ONCE(1);
4443 kt = 0;
4444 }
4445
4446 skb_set_delivery_time(skb, kt, tstamp_type);
4447}
4448
4449DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4450
4451/* It is used in the ingress path to clear the delivery_time.
4452 * If needed, set the skb->tstamp to the (rcv) timestamp.
4453 */
4454static inline void skb_clear_delivery_time(struct sk_buff *skb)
4455{
4456 if (skb->tstamp_type) {
4457 skb->tstamp_type = SKB_CLOCK_REALTIME;
4458 if (static_branch_unlikely(&netstamp_needed_key))
4459 skb->tstamp = ktime_get_real();
4460 else
4461 skb->tstamp = 0;
4462 }
4463}
4464
4465static inline void skb_clear_tstamp(struct sk_buff *skb)
4466{
4467 if (skb->tstamp_type)
4468 return;
4469
4470 skb->tstamp = 0;
4471}
4472
4473static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4474{
4475 if (skb->tstamp_type)
4476 return 0;
4477
4478 return skb->tstamp;
4479}
4480
4481static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4482{
4483 if (skb->tstamp_type != SKB_CLOCK_MONOTONIC && skb->tstamp)
4484 return skb->tstamp;
4485
4486 if (static_branch_unlikely(&netstamp_needed_key) || cond)
4487 return ktime_get_real();
4488
4489 return 0;
4490}
4491
4492static inline u8 skb_metadata_len(const struct sk_buff *skb)
4493{
4494 return skb_shinfo(skb)->meta_len;
4495}
4496
4497static inline void *skb_metadata_end(const struct sk_buff *skb)
4498{
4499 return skb_mac_header(skb);
4500}
4501
4502static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4503 const struct sk_buff *skb_b,
4504 u8 meta_len)
4505{
4506 const void *a = skb_metadata_end(skb: skb_a);
4507 const void *b = skb_metadata_end(skb: skb_b);
4508 u64 diffs = 0;
4509
4510 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
4511 BITS_PER_LONG != 64)
4512 goto slow;
4513
4514 /* Using more efficient variant than plain call to memcmp(). */
4515 switch (meta_len) {
4516#define __it(x, op) (x -= sizeof(u##op))
4517#define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
4518 case 32: diffs |= __it_diff(a, b, 64);
4519 fallthrough;
4520 case 24: diffs |= __it_diff(a, b, 64);
4521 fallthrough;
4522 case 16: diffs |= __it_diff(a, b, 64);
4523 fallthrough;
4524 case 8: diffs |= __it_diff(a, b, 64);
4525 break;
4526 case 28: diffs |= __it_diff(a, b, 64);
4527 fallthrough;
4528 case 20: diffs |= __it_diff(a, b, 64);
4529 fallthrough;
4530 case 12: diffs |= __it_diff(a, b, 64);
4531 fallthrough;
4532 case 4: diffs |= __it_diff(a, b, 32);
4533 break;
4534 default:
4535slow:
4536 return memcmp(a - meta_len, b - meta_len, meta_len);
4537 }
4538 return diffs;
4539}
4540
4541static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4542 const struct sk_buff *skb_b)
4543{
4544 u8 len_a = skb_metadata_len(skb: skb_a);
4545 u8 len_b = skb_metadata_len(skb: skb_b);
4546
4547 if (!(len_a | len_b))
4548 return false;
4549
4550 return len_a != len_b ?
4551 true : __skb_metadata_differs(skb_a, skb_b, meta_len: len_a);
4552}
4553
4554static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4555{
4556 skb_shinfo(skb)->meta_len = meta_len;
4557}
4558
4559static inline void skb_metadata_clear(struct sk_buff *skb)
4560{
4561 skb_metadata_set(skb, meta_len: 0);
4562}
4563
4564struct sk_buff *skb_clone_sk(struct sk_buff *skb);
4565
4566#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4567
4568void skb_clone_tx_timestamp(struct sk_buff *skb);
4569bool skb_defer_rx_timestamp(struct sk_buff *skb);
4570
4571#else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4572
4573static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4574{
4575}
4576
4577static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4578{
4579 return false;
4580}
4581
4582#endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4583
4584/**
4585 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4586 *
4587 * PHY drivers may accept clones of transmitted packets for
4588 * timestamping via their phy_driver.txtstamp method. These drivers
4589 * must call this function to return the skb back to the stack with a
4590 * timestamp.
4591 *
4592 * @skb: clone of the original outgoing packet
4593 * @hwtstamps: hardware time stamps
4594 *
4595 */
4596void skb_complete_tx_timestamp(struct sk_buff *skb,
4597 struct skb_shared_hwtstamps *hwtstamps);
4598
4599void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
4600 struct skb_shared_hwtstamps *hwtstamps,
4601 struct sock *sk, int tstype);
4602
4603/**
4604 * skb_tstamp_tx - queue clone of skb with send time stamps
4605 * @orig_skb: the original outgoing packet
4606 * @hwtstamps: hardware time stamps, may be NULL if not available
4607 *
4608 * If the skb has a socket associated, then this function clones the
4609 * skb (thus sharing the actual data and optional structures), stores
4610 * the optional hardware time stamping information (if non NULL) or
4611 * generates a software time stamp (otherwise), then queues the clone
4612 * to the error queue of the socket. Errors are silently ignored.
4613 */
4614void skb_tstamp_tx(struct sk_buff *orig_skb,
4615 struct skb_shared_hwtstamps *hwtstamps);
4616
4617/**
4618 * skb_tx_timestamp() - Driver hook for transmit timestamping
4619 *
4620 * Ethernet MAC Drivers should call this function in their hard_xmit()
4621 * function immediately before giving the sk_buff to the MAC hardware.
4622 *
4623 * Specifically, one should make absolutely sure that this function is
4624 * called before TX completion of this packet can trigger. Otherwise
4625 * the packet could potentially already be freed.
4626 *
4627 * @skb: A socket buffer.
4628 */
4629static inline void skb_tx_timestamp(struct sk_buff *skb)
4630{
4631 skb_clone_tx_timestamp(skb);
4632 if (skb_shinfo(skb)->tx_flags & (SKBTX_SW_TSTAMP | SKBTX_BPF))
4633 skb_tstamp_tx(orig_skb: skb, NULL);
4634}
4635
4636/**
4637 * skb_complete_wifi_ack - deliver skb with wifi status
4638 *
4639 * @skb: the original outgoing packet
4640 * @acked: ack status
4641 *
4642 */
4643void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4644
4645__sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
4646__sum16 __skb_checksum_complete(struct sk_buff *skb);
4647
4648static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4649{
4650 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
4651 skb->csum_valid ||
4652 (skb->ip_summed == CHECKSUM_PARTIAL &&
4653 skb_checksum_start_offset(skb) >= 0));
4654}
4655
4656/**
4657 * skb_checksum_complete - Calculate checksum of an entire packet
4658 * @skb: packet to process
4659 *
4660 * This function calculates the checksum over the entire packet plus
4661 * the value of skb->csum. The latter can be used to supply the
4662 * checksum of a pseudo header as used by TCP/UDP. It returns the
4663 * checksum.
4664 *
4665 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
4666 * this function can be used to verify that checksum on received
4667 * packets. In that case the function should return zero if the
4668 * checksum is correct. In particular, this function will return zero
4669 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4670 * hardware has already verified the correctness of the checksum.
4671 */
4672static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4673{
4674 return skb_csum_unnecessary(skb) ?
4675 0 : __skb_checksum_complete(skb);
4676}
4677
4678static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4679{
4680 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4681 if (skb->csum_level == 0)
4682 skb->ip_summed = CHECKSUM_NONE;
4683 else
4684 skb->csum_level--;
4685 }
4686}
4687
4688static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4689{
4690 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4691 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4692 skb->csum_level++;
4693 } else if (skb->ip_summed == CHECKSUM_NONE) {
4694 skb->ip_summed = CHECKSUM_UNNECESSARY;
4695 skb->csum_level = 0;
4696 }
4697}
4698
4699static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4700{
4701 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4702 skb->ip_summed = CHECKSUM_NONE;
4703 skb->csum_level = 0;
4704 }
4705}
4706
4707/* Check if we need to perform checksum complete validation.
4708 *
4709 * Returns: true if checksum complete is needed, false otherwise
4710 * (either checksum is unnecessary or zero checksum is allowed).
4711 */
4712static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4713 bool zero_okay,
4714 __sum16 check)
4715{
4716 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4717 skb->csum_valid = 1;
4718 __skb_decr_checksum_unnecessary(skb);
4719 return false;
4720 }
4721
4722 return true;
4723}
4724
4725/* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4726 * in checksum_init.
4727 */
4728#define CHECKSUM_BREAK 76
4729
4730/* Unset checksum-complete
4731 *
4732 * Unset checksum complete can be done when packet is being modified
4733 * (uncompressed for instance) and checksum-complete value is
4734 * invalidated.
4735 */
4736static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4737{
4738 if (skb->ip_summed == CHECKSUM_COMPLETE)
4739 skb->ip_summed = CHECKSUM_NONE;
4740}
4741
4742/* Validate (init) checksum based on checksum complete.
4743 *
4744 * Return values:
4745 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
4746 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4747 * checksum is stored in skb->csum for use in __skb_checksum_complete
4748 * non-zero: value of invalid checksum
4749 *
4750 */
4751static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4752 bool complete,
4753 __wsum psum)
4754{
4755 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4756 if (!csum_fold(sum: csum_add(csum: psum, addend: skb->csum))) {
4757 skb->csum_valid = 1;
4758 return 0;
4759 }
4760 }
4761
4762 skb->csum = psum;
4763
4764 if (complete || skb->len <= CHECKSUM_BREAK) {
4765 __sum16 csum;
4766
4767 csum = __skb_checksum_complete(skb);
4768 skb->csum_valid = !csum;
4769 return csum;
4770 }
4771
4772 return 0;
4773}
4774
4775static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4776{
4777 return 0;
4778}
4779
4780/* Perform checksum validate (init). Note that this is a macro since we only
4781 * want to calculate the pseudo header which is an input function if necessary.
4782 * First we try to validate without any computation (checksum unnecessary) and
4783 * then calculate based on checksum complete calling the function to compute
4784 * pseudo header.
4785 *
4786 * Return values:
4787 * 0: checksum is validated or try to in skb_checksum_complete
4788 * non-zero: value of invalid checksum
4789 */
4790#define __skb_checksum_validate(skb, proto, complete, \
4791 zero_okay, check, compute_pseudo) \
4792({ \
4793 __sum16 __ret = 0; \
4794 skb->csum_valid = 0; \
4795 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4796 __ret = __skb_checksum_validate_complete(skb, \
4797 complete, compute_pseudo(skb, proto)); \
4798 __ret; \
4799})
4800
4801#define skb_checksum_init(skb, proto, compute_pseudo) \
4802 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4803
4804#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4805 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4806
4807#define skb_checksum_validate(skb, proto, compute_pseudo) \
4808 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4809
4810#define skb_checksum_validate_zero_check(skb, proto, check, \
4811 compute_pseudo) \
4812 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4813
4814#define skb_checksum_simple_validate(skb) \
4815 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4816
4817static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4818{
4819 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4820}
4821
4822static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4823{
4824 skb->csum = ~pseudo;
4825 skb->ip_summed = CHECKSUM_COMPLETE;
4826}
4827
4828#define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4829do { \
4830 if (__skb_checksum_convert_check(skb)) \
4831 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4832} while (0)
4833
4834static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4835 u16 start, u16 offset)
4836{
4837 skb->ip_summed = CHECKSUM_PARTIAL;
4838 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4839 skb->csum_offset = offset - start;
4840}
4841
4842/* Update skbuf and packet to reflect the remote checksum offload operation.
4843 * When called, ptr indicates the starting point for skb->csum when
4844 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4845 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4846 */
4847static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4848 int start, int offset, bool nopartial)
4849{
4850 __wsum delta;
4851
4852 if (!nopartial) {
4853 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4854 return;
4855 }
4856
4857 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4858 __skb_checksum_complete(skb);
4859 skb_postpull_rcsum(skb, start: skb->data, len: ptr - (void *)skb->data);
4860 }
4861
4862 delta = remcsum_adjust(ptr, csum: skb->csum, start, offset);
4863
4864 /* Adjust skb->csum since we changed the packet */
4865 skb->csum = csum_add(csum: skb->csum, addend: delta);
4866}
4867
4868static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4869{
4870#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4871 return (void *)(skb->_nfct & NFCT_PTRMASK);
4872#else
4873 return NULL;
4874#endif
4875}
4876
4877static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4878{
4879#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4880 return skb->_nfct;
4881#else
4882 return 0UL;
4883#endif
4884}
4885
4886static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4887{
4888#if IS_ENABLED(CONFIG_NF_CONNTRACK)
4889 skb->slow_gro |= !!nfct;
4890 skb->_nfct = nfct;
4891#endif
4892}
4893
4894#ifdef CONFIG_SKB_EXTENSIONS
4895enum skb_ext_id {
4896#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4897 SKB_EXT_BRIDGE_NF,
4898#endif
4899#ifdef CONFIG_XFRM
4900 SKB_EXT_SEC_PATH,
4901#endif
4902#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4903 TC_SKB_EXT,
4904#endif
4905#if IS_ENABLED(CONFIG_MPTCP)
4906 SKB_EXT_MPTCP,
4907#endif
4908#if IS_ENABLED(CONFIG_MCTP_FLOWS)
4909 SKB_EXT_MCTP,
4910#endif
4911#if IS_ENABLED(CONFIG_INET_PSP)
4912 SKB_EXT_PSP,
4913#endif
4914 SKB_EXT_NUM, /* must be last */
4915};
4916
4917/**
4918 * struct skb_ext - sk_buff extensions
4919 * @refcnt: 1 on allocation, deallocated on 0
4920 * @offset: offset to add to @data to obtain extension address
4921 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4922 * @data: start of extension data, variable sized
4923 *
4924 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4925 * to use 'u8' types while allowing up to 2kb worth of extension data.
4926 */
4927struct skb_ext {
4928 refcount_t refcnt;
4929 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4930 u8 chunks; /* same */
4931 char data[] __aligned(8);
4932};
4933
4934struct skb_ext *__skb_ext_alloc(gfp_t flags);
4935void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4936 struct skb_ext *ext);
4937void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4938void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4939void __skb_ext_put(struct skb_ext *ext);
4940
4941static inline void skb_ext_put(struct sk_buff *skb)
4942{
4943 if (skb->active_extensions)
4944 __skb_ext_put(ext: skb->extensions);
4945}
4946
4947static inline void __skb_ext_copy(struct sk_buff *dst,
4948 const struct sk_buff *src)
4949{
4950 dst->active_extensions = src->active_extensions;
4951
4952 if (src->active_extensions) {
4953 struct skb_ext *ext = src->extensions;
4954
4955 refcount_inc(r: &ext->refcnt);
4956 dst->extensions = ext;
4957 }
4958}
4959
4960static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4961{
4962 skb_ext_put(skb: dst);
4963 __skb_ext_copy(dst, src);
4964}
4965
4966static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4967{
4968 return !!ext->offset[i];
4969}
4970
4971static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4972{
4973 return skb->active_extensions & (1 << id);
4974}
4975
4976static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4977{
4978 if (skb_ext_exist(skb, id))
4979 __skb_ext_del(skb, id);
4980}
4981
4982static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4983{
4984 if (skb_ext_exist(skb, id)) {
4985 struct skb_ext *ext = skb->extensions;
4986
4987 return (void *)ext + (ext->offset[id] << 3);
4988 }
4989
4990 return NULL;
4991}
4992
4993static inline void skb_ext_reset(struct sk_buff *skb)
4994{
4995 if (unlikely(skb->active_extensions)) {
4996 __skb_ext_put(ext: skb->extensions);
4997 skb->active_extensions = 0;
4998 }
4999}
5000
5001static inline bool skb_has_extensions(struct sk_buff *skb)
5002{
5003 return unlikely(skb->active_extensions);
5004}
5005#else
5006static inline void skb_ext_put(struct sk_buff *skb) {}
5007static inline void skb_ext_reset(struct sk_buff *skb) {}
5008static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
5009static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
5010static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
5011static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
5012#endif /* CONFIG_SKB_EXTENSIONS */
5013
5014static inline void nf_reset_ct(struct sk_buff *skb)
5015{
5016#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
5017 nf_conntrack_put(nfct: skb_nfct(skb));
5018 skb->_nfct = 0;
5019#endif
5020}
5021
5022static inline void nf_reset_trace(struct sk_buff *skb)
5023{
5024#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
5025 skb->nf_trace = 0;
5026#endif
5027}
5028
5029static inline void ipvs_reset(struct sk_buff *skb)
5030{
5031#if IS_ENABLED(CONFIG_IP_VS)
5032 skb->ipvs_property = 0;
5033#endif
5034}
5035
5036/* Note: This doesn't put any conntrack info in dst. */
5037static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
5038 bool copy)
5039{
5040#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
5041 dst->_nfct = src->_nfct;
5042 nf_conntrack_get(nfct: skb_nfct(skb: src));
5043#endif
5044#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
5045 if (copy)
5046 dst->nf_trace = src->nf_trace;
5047#endif
5048}
5049
5050static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
5051{
5052#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
5053 nf_conntrack_put(nfct: skb_nfct(skb: dst));
5054#endif
5055 dst->slow_gro = src->slow_gro;
5056 __nf_copy(dst, src, copy: true);
5057}
5058
5059#ifdef CONFIG_NETWORK_SECMARK
5060static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
5061{
5062 to->secmark = from->secmark;
5063}
5064
5065static inline void skb_init_secmark(struct sk_buff *skb)
5066{
5067 skb->secmark = 0;
5068}
5069#else
5070static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
5071{ }
5072
5073static inline void skb_init_secmark(struct sk_buff *skb)
5074{ }
5075#endif
5076
5077static inline int secpath_exists(const struct sk_buff *skb)
5078{
5079#ifdef CONFIG_XFRM
5080 return skb_ext_exist(skb, id: SKB_EXT_SEC_PATH);
5081#else
5082 return 0;
5083#endif
5084}
5085
5086static inline bool skb_irq_freeable(const struct sk_buff *skb)
5087{
5088 return !skb->destructor &&
5089 !secpath_exists(skb) &&
5090 !skb_nfct(skb) &&
5091 !skb->_skb_refdst &&
5092 !skb_has_frag_list(skb);
5093}
5094
5095static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
5096{
5097 skb->queue_mapping = queue_mapping;
5098}
5099
5100static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
5101{
5102 return skb->queue_mapping;
5103}
5104
5105static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
5106{
5107 to->queue_mapping = from->queue_mapping;
5108}
5109
5110static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
5111{
5112 skb->queue_mapping = rx_queue + 1;
5113}
5114
5115static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
5116{
5117 return skb->queue_mapping - 1;
5118}
5119
5120static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
5121{
5122 return skb->queue_mapping != 0;
5123}
5124
5125static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
5126{
5127 skb->dst_pending_confirm = val;
5128}
5129
5130static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
5131{
5132 return skb->dst_pending_confirm != 0;
5133}
5134
5135static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
5136{
5137#ifdef CONFIG_XFRM
5138 return skb_ext_find(skb, id: SKB_EXT_SEC_PATH);
5139#else
5140 return NULL;
5141#endif
5142}
5143
5144static inline bool skb_is_gso(const struct sk_buff *skb)
5145{
5146 return skb_shinfo(skb)->gso_size;
5147}
5148
5149/* Note: Should be called only if skb_is_gso(skb) is true */
5150static inline bool skb_is_gso_v6(const struct sk_buff *skb)
5151{
5152 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
5153}
5154
5155/* Note: Should be called only if skb_is_gso(skb) is true */
5156static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
5157{
5158 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
5159}
5160
5161/* Note: Should be called only if skb_is_gso(skb) is true */
5162static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
5163{
5164 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
5165}
5166
5167static inline void skb_gso_reset(struct sk_buff *skb)
5168{
5169 skb_shinfo(skb)->gso_size = 0;
5170 skb_shinfo(skb)->gso_segs = 0;
5171 skb_shinfo(skb)->gso_type = 0;
5172}
5173
5174static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
5175 u16 increment)
5176{
5177 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5178 return;
5179 shinfo->gso_size += increment;
5180}
5181
5182static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
5183 u16 decrement)
5184{
5185 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
5186 return;
5187 shinfo->gso_size -= decrement;
5188}
5189
5190void __skb_warn_lro_forwarding(const struct sk_buff *skb);
5191
5192static inline bool skb_warn_if_lro(const struct sk_buff *skb)
5193{
5194 /* LRO sets gso_size but not gso_type, whereas if GSO is really
5195 * wanted then gso_type will be set. */
5196 const struct skb_shared_info *shinfo = skb_shinfo(skb);
5197
5198 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
5199 unlikely(shinfo->gso_type == 0)) {
5200 __skb_warn_lro_forwarding(skb);
5201 return true;
5202 }
5203 return false;
5204}
5205
5206static inline void skb_forward_csum(struct sk_buff *skb)
5207{
5208 /* Unfortunately we don't support this one. Any brave souls? */
5209 if (skb->ip_summed == CHECKSUM_COMPLETE)
5210 skb->ip_summed = CHECKSUM_NONE;
5211}
5212
5213/**
5214 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
5215 * @skb: skb to check
5216 *
5217 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
5218 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
5219 * use this helper, to document places where we make this assertion.
5220 */
5221static inline void skb_checksum_none_assert(const struct sk_buff *skb)
5222{
5223 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
5224}
5225
5226bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
5227
5228int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
5229struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
5230 unsigned int transport_len,
5231 __sum16(*skb_chkf)(struct sk_buff *skb));
5232
5233/**
5234 * skb_head_is_locked - Determine if the skb->head is locked down
5235 * @skb: skb to check
5236 *
5237 * The head on skbs build around a head frag can be removed if they are
5238 * not cloned. This function returns true if the skb head is locked down
5239 * due to either being allocated via kmalloc, or by being a clone with
5240 * multiple references to the head.
5241 */
5242static inline bool skb_head_is_locked(const struct sk_buff *skb)
5243{
5244 return !skb->head_frag || skb_cloned(skb);
5245}
5246
5247/* Local Checksum Offload.
5248 * Compute outer checksum based on the assumption that the
5249 * inner checksum will be offloaded later.
5250 * See Documentation/networking/checksum-offloads.rst for
5251 * explanation of how this works.
5252 * Fill in outer checksum adjustment (e.g. with sum of outer
5253 * pseudo-header) before calling.
5254 * Also ensure that inner checksum is in linear data area.
5255 */
5256static inline __wsum lco_csum(struct sk_buff *skb)
5257{
5258 unsigned char *csum_start = skb_checksum_start(skb);
5259 unsigned char *l4_hdr = skb_transport_header(skb);
5260 __wsum partial;
5261
5262 /* Start with complement of inner checksum adjustment */
5263 partial = ~csum_unfold(n: *(__force __sum16 *)(csum_start +
5264 skb->csum_offset));
5265
5266 /* Add in checksum of our headers (incl. outer checksum
5267 * adjustment filled in by caller) and return result.
5268 */
5269 return csum_partial(buff: l4_hdr, len: csum_start - l4_hdr, sum: partial);
5270}
5271
5272static inline bool skb_is_redirected(const struct sk_buff *skb)
5273{
5274 return skb->redirected;
5275}
5276
5277static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
5278{
5279 skb->redirected = 1;
5280#ifdef CONFIG_NET_REDIRECT
5281 skb->from_ingress = from_ingress;
5282 if (skb->from_ingress)
5283 skb_clear_tstamp(skb);
5284#endif
5285}
5286
5287static inline void skb_reset_redirect(struct sk_buff *skb)
5288{
5289 skb->redirected = 0;
5290}
5291
5292static inline void skb_set_redirected_noclear(struct sk_buff *skb,
5293 bool from_ingress)
5294{
5295 skb->redirected = 1;
5296#ifdef CONFIG_NET_REDIRECT
5297 skb->from_ingress = from_ingress;
5298#endif
5299}
5300
5301static inline bool skb_csum_is_sctp(struct sk_buff *skb)
5302{
5303#if IS_ENABLED(CONFIG_IP_SCTP)
5304 return skb->csum_not_inet;
5305#else
5306 return 0;
5307#endif
5308}
5309
5310static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
5311{
5312 skb->ip_summed = CHECKSUM_NONE;
5313#if IS_ENABLED(CONFIG_IP_SCTP)
5314 skb->csum_not_inet = 0;
5315#endif
5316}
5317
5318static inline void skb_set_kcov_handle(struct sk_buff *skb,
5319 const u64 kcov_handle)
5320{
5321#ifdef CONFIG_KCOV
5322 skb->kcov_handle = kcov_handle;
5323#endif
5324}
5325
5326static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
5327{
5328#ifdef CONFIG_KCOV
5329 return skb->kcov_handle;
5330#else
5331 return 0;
5332#endif
5333}
5334
5335static inline void skb_mark_for_recycle(struct sk_buff *skb)
5336{
5337#ifdef CONFIG_PAGE_POOL
5338 skb->pp_recycle = 1;
5339#endif
5340}
5341
5342ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter,
5343 ssize_t maxsize);
5344
5345#endif /* __KERNEL__ */
5346#endif /* _LINUX_SKBUFF_H */
5347