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 <net/flow.h>
35 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
36 #include <linux/netfilter/nf_conntrack_common.h>
37 #endif
38 #include <net/net_debug.h>
39 #include <net/dropreason-core.h>
40 #include <net/netmem.h>
41
42 /**
43 * DOC: skb checksums
44 *
45 * The interface for checksum offload between the stack and networking drivers
46 * is as follows...
47 *
48 * IP checksum related features
49 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
50 *
51 * Drivers advertise checksum offload capabilities in the features of a device.
52 * From the stack's point of view these are capabilities offered by the driver.
53 * A driver typically only advertises features that it is capable of offloading
54 * to its device.
55 *
56 * .. flat-table:: Checksum related device features
57 * :widths: 1 10
58 *
59 * * - %NETIF_F_HW_CSUM
60 * - The driver (or its device) is able to compute one
61 * IP (one's complement) checksum for any combination
62 * of protocols or protocol layering. The checksum is
63 * computed and set in a packet per the CHECKSUM_PARTIAL
64 * interface (see below).
65 *
66 * * - %NETIF_F_IP_CSUM
67 * - Driver (device) is only able to checksum plain
68 * TCP or UDP packets over IPv4. These are specifically
69 * unencapsulated packets of the form IPv4|TCP or
70 * IPv4|UDP where the Protocol field in the IPv4 header
71 * is TCP or UDP. The IPv4 header may contain IP options.
72 * This feature cannot be set in features for a device
73 * with NETIF_F_HW_CSUM also set. This feature is being
74 * DEPRECATED (see below).
75 *
76 * * - %NETIF_F_IPV6_CSUM
77 * - Driver (device) is only able to checksum plain
78 * TCP or UDP packets over IPv6. These are specifically
79 * unencapsulated packets of the form IPv6|TCP or
80 * IPv6|UDP where the Next Header field in the IPv6
81 * header is either TCP or UDP. IPv6 extension headers
82 * are not supported with this feature. This feature
83 * cannot be set in features for a device with
84 * NETIF_F_HW_CSUM also set. This feature is being
85 * DEPRECATED (see below).
86 *
87 * * - %NETIF_F_RXCSUM
88 * - Driver (device) performs receive checksum offload.
89 * This flag is only used to disable the RX checksum
90 * feature for a device. The stack will accept receive
91 * checksum indication in packets received on a device
92 * regardless of whether NETIF_F_RXCSUM is set.
93 *
94 * Checksumming of received packets by device
95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
96 *
97 * Indication of checksum verification is set in &sk_buff.ip_summed.
98 * Possible values are:
99 *
100 * - %CHECKSUM_NONE
101 *
102 * Device did not checksum this packet e.g. due to lack of capabilities.
103 * The packet contains full (though not verified) checksum in packet but
104 * not in skb->csum. Thus, skb->csum is undefined in this case.
105 *
106 * - %CHECKSUM_UNNECESSARY
107 *
108 * The hardware you're dealing with doesn't calculate the full checksum
109 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
110 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
111 * if their checksums are okay. &sk_buff.csum is still undefined in this case
112 * though. A driver or device must never modify the checksum field in the
113 * packet even if checksum is verified.
114 *
115 * %CHECKSUM_UNNECESSARY is applicable to following protocols:
116 *
117 * - TCP: IPv6 and IPv4.
118 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
119 * zero UDP checksum for either IPv4 or IPv6, the networking stack
120 * may perform further validation in this case.
121 * - GRE: only if the checksum is present in the header.
122 * - SCTP: indicates the CRC in SCTP header has been validated.
123 * - FCOE: indicates the CRC in FC frame has been validated.
124 *
125 * &sk_buff.csum_level indicates the number of consecutive checksums found in
126 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
127 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
128 * and a device is able to verify the checksums for UDP (possibly zero),
129 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
130 * two. If the device were only able to verify the UDP checksum and not
131 * GRE, either because it doesn't support GRE checksum or because GRE
132 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
133 * not considered in this case).
134 *
135 * - %CHECKSUM_COMPLETE
136 *
137 * This is the most generic way. The device supplied checksum of the _whole_
138 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
139 * hardware doesn't need to parse L3/L4 headers to implement this.
140 *
141 * Notes:
142 *
143 * - Even if device supports only some protocols, but is able to produce
144 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
145 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
146 *
147 * - %CHECKSUM_PARTIAL
148 *
149 * A checksum is set up to be offloaded to a device as described in the
150 * output description for CHECKSUM_PARTIAL. This may occur on a packet
151 * received directly from another Linux OS, e.g., a virtualized Linux kernel
152 * on the same host, or it may be set in the input path in GRO or remote
153 * checksum offload. For the purposes of checksum verification, the checksum
154 * referred to by skb->csum_start + skb->csum_offset and any preceding
155 * checksums in the packet are considered verified. Any checksums in the
156 * packet that are after the checksum being offloaded are not considered to
157 * be verified.
158 *
159 * Checksumming on transmit for non-GSO
160 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
161 *
162 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
163 * Values are:
164 *
165 * - %CHECKSUM_PARTIAL
166 *
167 * The driver is required to checksum the packet as seen by hard_start_xmit()
168 * from &sk_buff.csum_start up to the end, and to record/write the checksum at
169 * offset &sk_buff.csum_start + &sk_buff.csum_offset.
170 * A driver may verify that the
171 * csum_start and csum_offset values are valid values given the length and
172 * offset of the packet, but it should not attempt to validate that the
173 * checksum refers to a legitimate transport layer checksum -- it is the
174 * purview of the stack to validate that csum_start and csum_offset are set
175 * correctly.
176 *
177 * When the stack requests checksum offload for a packet, the driver MUST
178 * ensure that the checksum is set correctly. A driver can either offload the
179 * checksum calculation to the device, or call skb_checksum_help (in the case
180 * that the device does not support offload for a particular checksum).
181 *
182 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
183 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
184 * checksum offload capability.
185 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
186 * on network device checksumming capabilities: if a packet does not match
187 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
188 * &sk_buff.csum_not_inet, see :ref:`crc`)
189 * is called to resolve the checksum.
190 *
191 * - %CHECKSUM_NONE
192 *
193 * The skb was already checksummed by the protocol, or a checksum is not
194 * required.
195 *
196 * - %CHECKSUM_UNNECESSARY
197 *
198 * This has the same meaning as CHECKSUM_NONE for checksum offload on
199 * output.
200 *
201 * - %CHECKSUM_COMPLETE
202 *
203 * Not used in checksum output. If a driver observes a packet with this value
204 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
205 *
206 * .. _crc:
207 *
208 * Non-IP checksum (CRC) offloads
209 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
210 *
211 * .. flat-table::
212 * :widths: 1 10
213 *
214 * * - %NETIF_F_SCTP_CRC
215 * - This feature indicates that a device is capable of
216 * offloading the SCTP CRC in a packet. To perform this offload the stack
217 * will set csum_start and csum_offset accordingly, set ip_summed to
218 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
219 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
220 * A driver that supports both IP checksum offload and SCTP CRC32c offload
221 * must verify which offload is configured for a packet by testing the
222 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
223 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
224 *
225 * * - %NETIF_F_FCOE_CRC
226 * - This feature indicates that a device is capable of offloading the FCOE
227 * CRC in a packet. To perform this offload the stack will set ip_summed
228 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset
229 * accordingly. Note that there is no indication in the skbuff that the
230 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
231 * both IP checksum offload and FCOE CRC offload must verify which offload
232 * is configured for a packet, presumably by inspecting packet headers.
233 *
234 * Checksumming on output with GSO
235 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
236 *
237 * In the case of a GSO packet (skb_is_gso() is true), checksum offload
238 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
239 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
240 * part of the GSO operation is implied. If a checksum is being offloaded
241 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
242 * csum_offset are set to refer to the outermost checksum being offloaded
243 * (two offloaded checksums are possible with UDP encapsulation).
244 */
245
246 /* Don't change this without changing skb_csum_unnecessary! */
247 #define CHECKSUM_NONE 0
248 #define CHECKSUM_UNNECESSARY 1
249 #define CHECKSUM_COMPLETE 2
250 #define CHECKSUM_PARTIAL 3
251
252 /* Maximum value in skb->csum_level */
253 #define SKB_MAX_CSUM_LEVEL 3
254
255 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
256 #define SKB_WITH_OVERHEAD(X) \
257 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
258
259 /* For X bytes available in skb->head, what is the minimal
260 * allocation needed, knowing struct skb_shared_info needs
261 * to be aligned.
262 */
263 #define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \
264 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
265
266 #define SKB_MAX_ORDER(X, ORDER) \
267 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
268 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
269 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
270
271 /* return minimum truesize of one skb containing X bytes of data */
272 #define SKB_TRUESIZE(X) ((X) + \
273 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
274 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
275
276 struct ahash_request;
277 struct net_device;
278 struct scatterlist;
279 struct pipe_inode_info;
280 struct iov_iter;
281 struct napi_struct;
282 struct bpf_prog;
283 union bpf_attr;
284 struct skb_ext;
285 struct ts_config;
286
287 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
288 struct 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 */
322 struct 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
337 struct sk_buff_head {
338 /* These two members must be first to match sk_buff. */
339 struct_group_tagged(sk_buff_list, list,
340 struct sk_buff *next;
341 struct sk_buff *prev;
342 );
343
344 __u32 qlen;
345 spinlock_t lock;
346 };
347
348 struct 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
361 typedef 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 */
skb_frag_size(const skb_frag_t * frag)371 static 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 */
skb_frag_size_set(skb_frag_t * frag,unsigned int size)381 static 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 */
skb_frag_size_add(skb_frag_t * frag,int delta)391 static 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 */
skb_frag_size_sub(skb_frag_t * frag,int delta)401 static 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 */
skb_frag_must_loop(struct page * p)410 static 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 */
462 struct 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 */
470 enum {
471 /* generate hardware time stamp */
472 SKBTX_HW_TSTAMP = 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 hardware time stamp based on cycles if supported */
481 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3,
482
483 /* generate wifi status information (where possible) */
484 SKBTX_WIFI_STATUS = 1 << 4,
485
486 /* determine hardware time stamp based on time or cycles */
487 SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
488
489 /* generate software time stamp when entering packet scheduling */
490 SKBTX_SCHED_TSTAMP = 1 << 6,
491 };
492
493 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
494 SKBTX_SCHED_TSTAMP)
495 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
496 SKBTX_HW_TSTAMP_USE_CYCLES | \
497 SKBTX_ANY_SW_TSTAMP)
498
499 /* Definitions for flags in struct skb_shared_info */
500 enum {
501 /* use zcopy routines */
502 SKBFL_ZEROCOPY_ENABLE = BIT(0),
503
504 /* This indicates at least one fragment might be overwritten
505 * (as in vmsplice(), sendfile() ...)
506 * If we need to compute a TX checksum, we'll need to copy
507 * all frags to avoid possible bad checksum
508 */
509 SKBFL_SHARED_FRAG = BIT(1),
510
511 /* segment contains only zerocopy data and should not be
512 * charged to the kernel memory.
513 */
514 SKBFL_PURE_ZEROCOPY = BIT(2),
515
516 SKBFL_DONT_ORPHAN = BIT(3),
517
518 /* page references are managed by the ubuf_info, so it's safe to
519 * use frags only up until ubuf_info is released
520 */
521 SKBFL_MANAGED_FRAG_REFS = BIT(4),
522 };
523
524 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
525 #define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
526 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS)
527
528 struct ubuf_info_ops {
529 void (*complete)(struct sk_buff *, struct ubuf_info *,
530 bool zerocopy_success);
531 /* has to be compatible with skb_zcopy_set() */
532 int (*link_skb)(struct sk_buff *skb, struct ubuf_info *uarg);
533 };
534
535 /*
536 * The callback notifies userspace to release buffers when skb DMA is done in
537 * lower device, the skb last reference should be 0 when calling this.
538 * The zerocopy_success argument is true if zero copy transmit occurred,
539 * false on data copy or out of memory error caused by data copy attempt.
540 * The ctx field is used to track device context.
541 * The desc field is used to track userspace buffer index.
542 */
543 struct ubuf_info {
544 const struct ubuf_info_ops *ops;
545 refcount_t refcnt;
546 u8 flags;
547 };
548
549 struct ubuf_info_msgzc {
550 struct ubuf_info ubuf;
551
552 union {
553 struct {
554 unsigned long desc;
555 void *ctx;
556 };
557 struct {
558 u32 id;
559 u16 len;
560 u16 zerocopy:1;
561 u32 bytelen;
562 };
563 };
564
565 struct mmpin {
566 struct user_struct *user;
567 unsigned int num_pg;
568 } mmp;
569 };
570
571 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
572 #define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \
573 ubuf)
574
575 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
576 void mm_unaccount_pinned_pages(struct mmpin *mmp);
577
578 /* Preserve some data across TX submission and completion.
579 *
580 * Note, this state is stored in the driver. Extending the layout
581 * might need some special care.
582 */
583 struct xsk_tx_metadata_compl {
584 __u64 *tx_timestamp;
585 };
586
587 /* This data is invariant across clones and lives at
588 * the end of the header data, ie. at skb->end.
589 */
590 struct skb_shared_info {
591 __u8 flags;
592 __u8 meta_len;
593 __u8 nr_frags;
594 __u8 tx_flags;
595 unsigned short gso_size;
596 /* Warning: this field is not always filled in (UFO)! */
597 unsigned short gso_segs;
598 struct sk_buff *frag_list;
599 union {
600 struct skb_shared_hwtstamps hwtstamps;
601 struct xsk_tx_metadata_compl xsk_meta;
602 };
603 unsigned int gso_type;
604 u32 tskey;
605
606 /*
607 * Warning : all fields before dataref are cleared in __alloc_skb()
608 */
609 atomic_t dataref;
610 unsigned int xdp_frags_size;
611
612 /* Intermediate layers must ensure that destructor_arg
613 * remains valid until skb destructor */
614 void * destructor_arg;
615
616 /* must be last field, see pskb_expand_head() */
617 skb_frag_t frags[MAX_SKB_FRAGS];
618 };
619
620 /**
621 * DOC: dataref and headerless skbs
622 *
623 * Transport layers send out clones of payload skbs they hold for
624 * retransmissions. To allow lower layers of the stack to prepend their headers
625 * we split &skb_shared_info.dataref into two halves.
626 * The lower 16 bits count the overall number of references.
627 * The higher 16 bits indicate how many of the references are payload-only.
628 * skb_header_cloned() checks if skb is allowed to add / write the headers.
629 *
630 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
631 * (via __skb_header_release()). Any clone created from marked skb will get
632 * &sk_buff.hdr_len populated with the available headroom.
633 * If there's the only clone in existence it's able to modify the headroom
634 * at will. The sequence of calls inside the transport layer is::
635 *
636 * <alloc skb>
637 * skb_reserve()
638 * __skb_header_release()
639 * skb_clone()
640 * // send the clone down the stack
641 *
642 * This is not a very generic construct and it depends on the transport layers
643 * doing the right thing. In practice there's usually only one payload-only skb.
644 * Having multiple payload-only skbs with different lengths of hdr_len is not
645 * possible. The payload-only skbs should never leave their owner.
646 */
647 #define SKB_DATAREF_SHIFT 16
648 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
649
650
651 enum {
652 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
653 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
654 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
655 };
656
657 enum {
658 SKB_GSO_TCPV4 = 1 << 0,
659
660 /* This indicates the skb is from an untrusted source. */
661 SKB_GSO_DODGY = 1 << 1,
662
663 /* This indicates the tcp segment has CWR set. */
664 SKB_GSO_TCP_ECN = 1 << 2,
665
666 SKB_GSO_TCP_FIXEDID = 1 << 3,
667
668 SKB_GSO_TCPV6 = 1 << 4,
669
670 SKB_GSO_FCOE = 1 << 5,
671
672 SKB_GSO_GRE = 1 << 6,
673
674 SKB_GSO_GRE_CSUM = 1 << 7,
675
676 SKB_GSO_IPXIP4 = 1 << 8,
677
678 SKB_GSO_IPXIP6 = 1 << 9,
679
680 SKB_GSO_UDP_TUNNEL = 1 << 10,
681
682 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
683
684 SKB_GSO_PARTIAL = 1 << 12,
685
686 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
687
688 SKB_GSO_SCTP = 1 << 14,
689
690 SKB_GSO_ESP = 1 << 15,
691
692 SKB_GSO_UDP = 1 << 16,
693
694 SKB_GSO_UDP_L4 = 1 << 17,
695
696 SKB_GSO_FRAGLIST = 1 << 18,
697 };
698
699 #if BITS_PER_LONG > 32
700 #define NET_SKBUFF_DATA_USES_OFFSET 1
701 #endif
702
703 #ifdef NET_SKBUFF_DATA_USES_OFFSET
704 typedef unsigned int sk_buff_data_t;
705 #else
706 typedef unsigned char *sk_buff_data_t;
707 #endif
708
709 /**
710 * DOC: Basic sk_buff geometry
711 *
712 * struct sk_buff itself is a metadata structure and does not hold any packet
713 * data. All the data is held in associated buffers.
714 *
715 * &sk_buff.head points to the main "head" buffer. The head buffer is divided
716 * into two parts:
717 *
718 * - data buffer, containing headers and sometimes payload;
719 * this is the part of the skb operated on by the common helpers
720 * such as skb_put() or skb_pull();
721 * - shared info (struct skb_shared_info) which holds an array of pointers
722 * to read-only data in the (page, offset, length) format.
723 *
724 * Optionally &skb_shared_info.frag_list may point to another skb.
725 *
726 * Basic diagram may look like this::
727 *
728 * ---------------
729 * | sk_buff |
730 * ---------------
731 * ,--------------------------- + head
732 * / ,----------------- + data
733 * / / ,----------- + tail
734 * | | | , + end
735 * | | | |
736 * v v v v
737 * -----------------------------------------------
738 * | headroom | data | tailroom | skb_shared_info |
739 * -----------------------------------------------
740 * + [page frag]
741 * + [page frag]
742 * + [page frag]
743 * + [page frag] ---------
744 * + frag_list --> | sk_buff |
745 * ---------
746 *
747 */
748
749 /**
750 * struct sk_buff - socket buffer
751 * @next: Next buffer in list
752 * @prev: Previous buffer in list
753 * @tstamp: Time we arrived/left
754 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
755 * for retransmit timer
756 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
757 * @list: queue head
758 * @ll_node: anchor in an llist (eg socket defer_list)
759 * @sk: Socket we are owned by
760 * @dev: Device we arrived on/are leaving by
761 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
762 * @cb: Control buffer. Free for use by every layer. Put private vars here
763 * @_skb_refdst: destination entry (with norefcount bit)
764 * @len: Length of actual data
765 * @data_len: Data length
766 * @mac_len: Length of link layer header
767 * @hdr_len: writable header length of cloned skb
768 * @csum: Checksum (must include start/offset pair)
769 * @csum_start: Offset from skb->head where checksumming should start
770 * @csum_offset: Offset from csum_start where checksum should be stored
771 * @priority: Packet queueing priority
772 * @ignore_df: allow local fragmentation
773 * @cloned: Head may be cloned (check refcnt to be sure)
774 * @ip_summed: Driver fed us an IP checksum
775 * @nohdr: Payload reference only, must not modify header
776 * @pkt_type: Packet class
777 * @fclone: skbuff clone status
778 * @ipvs_property: skbuff is owned by ipvs
779 * @inner_protocol_type: whether the inner protocol is
780 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
781 * @remcsum_offload: remote checksum offload is enabled
782 * @offload_fwd_mark: Packet was L2-forwarded in hardware
783 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
784 * @tc_skip_classify: do not classify packet. set by IFB device
785 * @tc_at_ingress: used within tc_classify to distinguish in/egress
786 * @redirected: packet was redirected by packet classifier
787 * @from_ingress: packet was redirected from the ingress path
788 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
789 * @peeked: this packet has been seen already, so stats have been
790 * done for it, don't do them again
791 * @nf_trace: netfilter packet trace flag
792 * @protocol: Packet protocol from driver
793 * @destructor: Destruct function
794 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
795 * @_sk_redir: socket redirection information for skmsg
796 * @_nfct: Associated connection, if any (with nfctinfo bits)
797 * @skb_iif: ifindex of device we arrived on
798 * @tc_index: Traffic control index
799 * @hash: the packet hash
800 * @queue_mapping: Queue mapping for multiqueue devices
801 * @head_frag: skb was allocated from page fragments,
802 * not allocated by kmalloc() or vmalloc().
803 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
804 * @pp_recycle: mark the packet for recycling instead of freeing (implies
805 * page_pool support on driver)
806 * @active_extensions: active extensions (skb_ext_id types)
807 * @ndisc_nodetype: router type (from link layer)
808 * @ooo_okay: allow the mapping of a socket to a queue to be changed
809 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
810 * ports.
811 * @sw_hash: indicates hash was computed in software stack
812 * @wifi_acked_valid: wifi_acked was set
813 * @wifi_acked: whether frame was acked on wifi or not
814 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
815 * @encapsulation: indicates the inner headers in the skbuff are valid
816 * @encap_hdr_csum: software checksum is needed
817 * @csum_valid: checksum is already valid
818 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
819 * @csum_complete_sw: checksum was completed by software
820 * @csum_level: indicates the number of consecutive checksums found in
821 * the packet minus one that have been verified as
822 * CHECKSUM_UNNECESSARY (max 3)
823 * @dst_pending_confirm: need to confirm neighbour
824 * @decrypted: Decrypted SKB
825 * @slow_gro: state present at GRO time, slower prepare step required
826 * @mono_delivery_time: When set, skb->tstamp has the
827 * delivery_time in mono clock base (i.e. EDT). Otherwise, the
828 * skb->tstamp has the (rcv) timestamp at ingress and
829 * delivery_time at egress.
830 * @napi_id: id of the NAPI struct this skb came from
831 * @sender_cpu: (aka @napi_id) source CPU in XPS
832 * @alloc_cpu: CPU which did the skb allocation.
833 * @secmark: security marking
834 * @mark: Generic packet mark
835 * @reserved_tailroom: (aka @mark) number of bytes of free space available
836 * at the tail of an sk_buff
837 * @vlan_all: vlan fields (proto & tci)
838 * @vlan_proto: vlan encapsulation protocol
839 * @vlan_tci: vlan tag control information
840 * @inner_protocol: Protocol (encapsulation)
841 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
842 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
843 * @inner_transport_header: Inner transport layer header (encapsulation)
844 * @inner_network_header: Network layer header (encapsulation)
845 * @inner_mac_header: Link layer header (encapsulation)
846 * @transport_header: Transport layer header
847 * @network_header: Network layer header
848 * @mac_header: Link layer header
849 * @kcov_handle: KCOV remote handle for remote coverage collection
850 * @tail: Tail pointer
851 * @end: End pointer
852 * @head: Head of buffer
853 * @data: Data head pointer
854 * @truesize: Buffer size
855 * @users: User count - see {datagram,tcp}.c
856 * @extensions: allocated extensions, valid if active_extensions is nonzero
857 */
858
859 struct sk_buff {
860 union {
861 struct {
862 /* These two members must be first to match sk_buff_head. */
863 struct sk_buff *next;
864 struct sk_buff *prev;
865
866 union {
867 struct net_device *dev;
868 /* Some protocols might use this space to store information,
869 * while device pointer would be NULL.
870 * UDP receive path is one user.
871 */
872 unsigned long dev_scratch;
873 };
874 };
875 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
876 struct list_head list;
877 struct llist_node ll_node;
878 };
879
880 struct sock *sk;
881
882 union {
883 ktime_t tstamp;
884 u64 skb_mstamp_ns; /* earliest departure time */
885 };
886 /*
887 * This is the control buffer. It is free to use for every
888 * layer. Please put your private variables there. If you
889 * want to keep them across layers you have to do a skb_clone()
890 * first. This is owned by whoever has the skb queued ATM.
891 */
892 char cb[48] __aligned(8);
893
894 union {
895 struct {
896 unsigned long _skb_refdst;
897 void (*destructor)(struct sk_buff *skb);
898 };
899 struct list_head tcp_tsorted_anchor;
900 #ifdef CONFIG_NET_SOCK_MSG
901 unsigned long _sk_redir;
902 #endif
903 };
904
905 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
906 unsigned long _nfct;
907 #endif
908 unsigned int len,
909 data_len;
910 __u16 mac_len,
911 hdr_len;
912
913 /* Following fields are _not_ copied in __copy_skb_header()
914 * Note that queue_mapping is here mostly to fill a hole.
915 */
916 __u16 queue_mapping;
917
918 /* if you move cloned around you also must adapt those constants */
919 #ifdef __BIG_ENDIAN_BITFIELD
920 #define CLONED_MASK (1 << 7)
921 #else
922 #define CLONED_MASK 1
923 #endif
924 #define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset)
925
926 /* private: */
927 __u8 __cloned_offset[0];
928 /* public: */
929 __u8 cloned:1,
930 nohdr:1,
931 fclone:2,
932 peeked:1,
933 head_frag:1,
934 pfmemalloc:1,
935 pp_recycle:1; /* page_pool recycle indicator */
936 #ifdef CONFIG_SKB_EXTENSIONS
937 __u8 active_extensions;
938 #endif
939
940 /* Fields enclosed in headers group are copied
941 * using a single memcpy() in __copy_skb_header()
942 */
943 struct_group(headers,
944
945 /* private: */
946 __u8 __pkt_type_offset[0];
947 /* public: */
948 __u8 pkt_type:3; /* see PKT_TYPE_MAX */
949 __u8 ignore_df:1;
950 __u8 dst_pending_confirm:1;
951 __u8 ip_summed:2;
952 __u8 ooo_okay:1;
953
954 /* private: */
955 __u8 __mono_tc_offset[0];
956 /* public: */
957 __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */
958 #ifdef CONFIG_NET_XGRESS
959 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */
960 __u8 tc_skip_classify:1;
961 #endif
962 __u8 remcsum_offload:1;
963 __u8 csum_complete_sw:1;
964 __u8 csum_level:2;
965 __u8 inner_protocol_type:1;
966
967 __u8 l4_hash:1;
968 __u8 sw_hash:1;
969 #ifdef CONFIG_WIRELESS
970 __u8 wifi_acked_valid:1;
971 __u8 wifi_acked:1;
972 #endif
973 __u8 no_fcs:1;
974 /* Indicates the inner headers are valid in the skbuff. */
975 __u8 encapsulation:1;
976 __u8 encap_hdr_csum:1;
977 __u8 csum_valid:1;
978 #ifdef CONFIG_IPV6_NDISC_NODETYPE
979 __u8 ndisc_nodetype:2;
980 #endif
981
982 #if IS_ENABLED(CONFIG_IP_VS)
983 __u8 ipvs_property:1;
984 #endif
985 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
986 __u8 nf_trace:1;
987 #endif
988 #ifdef CONFIG_NET_SWITCHDEV
989 __u8 offload_fwd_mark:1;
990 __u8 offload_l3_fwd_mark:1;
991 #endif
992 __u8 redirected:1;
993 #ifdef CONFIG_NET_REDIRECT
994 __u8 from_ingress:1;
995 #endif
996 #ifdef CONFIG_NETFILTER_SKIP_EGRESS
997 __u8 nf_skip_egress:1;
998 #endif
999 #ifdef CONFIG_SKB_DECRYPTED
1000 __u8 decrypted:1;
1001 #endif
1002 __u8 slow_gro:1;
1003 #if IS_ENABLED(CONFIG_IP_SCTP)
1004 __u8 csum_not_inet:1;
1005 #endif
1006
1007 #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS)
1008 __u16 tc_index; /* traffic control index */
1009 #endif
1010
1011 u16 alloc_cpu;
1012
1013 union {
1014 __wsum csum;
1015 struct {
1016 __u16 csum_start;
1017 __u16 csum_offset;
1018 };
1019 };
1020 __u32 priority;
1021 int skb_iif;
1022 __u32 hash;
1023 union {
1024 u32 vlan_all;
1025 struct {
1026 __be16 vlan_proto;
1027 __u16 vlan_tci;
1028 };
1029 };
1030 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
1031 union {
1032 unsigned int napi_id;
1033 unsigned int sender_cpu;
1034 };
1035 #endif
1036 #ifdef CONFIG_NETWORK_SECMARK
1037 __u32 secmark;
1038 #endif
1039
1040 union {
1041 __u32 mark;
1042 __u32 reserved_tailroom;
1043 };
1044
1045 union {
1046 __be16 inner_protocol;
1047 __u8 inner_ipproto;
1048 };
1049
1050 __u16 inner_transport_header;
1051 __u16 inner_network_header;
1052 __u16 inner_mac_header;
1053
1054 __be16 protocol;
1055 __u16 transport_header;
1056 __u16 network_header;
1057 __u16 mac_header;
1058
1059 #ifdef CONFIG_KCOV
1060 u64 kcov_handle;
1061 #endif
1062
1063 ); /* end headers group */
1064
1065 /* These elements must be at the end, see alloc_skb() for details. */
1066 sk_buff_data_t tail;
1067 sk_buff_data_t end;
1068 unsigned char *head,
1069 *data;
1070 unsigned int truesize;
1071 refcount_t users;
1072
1073 #ifdef CONFIG_SKB_EXTENSIONS
1074 /* only usable after checking ->active_extensions != 0 */
1075 struct skb_ext *extensions;
1076 #endif
1077 };
1078
1079 /* if you move pkt_type around you also must adapt those constants */
1080 #ifdef __BIG_ENDIAN_BITFIELD
1081 #define PKT_TYPE_MAX (7 << 5)
1082 #else
1083 #define PKT_TYPE_MAX 7
1084 #endif
1085 #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
1086
1087 /* if you move tc_at_ingress or mono_delivery_time
1088 * around, you also must adapt these constants.
1089 */
1090 #ifdef __BIG_ENDIAN_BITFIELD
1091 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 7)
1092 #define TC_AT_INGRESS_MASK (1 << 6)
1093 #else
1094 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 0)
1095 #define TC_AT_INGRESS_MASK (1 << 1)
1096 #endif
1097 #define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset)
1098
1099 #ifdef __KERNEL__
1100 /*
1101 * Handling routines are only of interest to the kernel
1102 */
1103
1104 #define SKB_ALLOC_FCLONE 0x01
1105 #define SKB_ALLOC_RX 0x02
1106 #define SKB_ALLOC_NAPI 0x04
1107
1108 /**
1109 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1110 * @skb: buffer
1111 */
skb_pfmemalloc(const struct sk_buff * skb)1112 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1113 {
1114 return unlikely(skb->pfmemalloc);
1115 }
1116
1117 /*
1118 * skb might have a dst pointer attached, refcounted or not.
1119 * _skb_refdst low order bit is set if refcount was _not_ taken
1120 */
1121 #define SKB_DST_NOREF 1UL
1122 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
1123
1124 /**
1125 * skb_dst - returns skb dst_entry
1126 * @skb: buffer
1127 *
1128 * Returns skb dst_entry, regardless of reference taken or not.
1129 */
skb_dst(const struct sk_buff * skb)1130 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
1131 {
1132 /* If refdst was not refcounted, check we still are in a
1133 * rcu_read_lock section
1134 */
1135 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1136 !rcu_read_lock_held() &&
1137 !rcu_read_lock_bh_held());
1138 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1139 }
1140
1141 /**
1142 * skb_dst_set - sets skb dst
1143 * @skb: buffer
1144 * @dst: dst entry
1145 *
1146 * Sets skb dst, assuming a reference was taken on dst and should
1147 * be released by skb_dst_drop()
1148 */
skb_dst_set(struct sk_buff * skb,struct dst_entry * dst)1149 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
1150 {
1151 skb->slow_gro |= !!dst;
1152 skb->_skb_refdst = (unsigned long)dst;
1153 }
1154
1155 /**
1156 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1157 * @skb: buffer
1158 * @dst: dst entry
1159 *
1160 * Sets skb dst, assuming a reference was not taken on dst.
1161 * If dst entry is cached, we do not take reference and dst_release
1162 * will be avoided by refdst_drop. If dst entry is not cached, we take
1163 * reference, so that last dst_release can destroy the dst immediately.
1164 */
skb_dst_set_noref(struct sk_buff * skb,struct dst_entry * dst)1165 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1166 {
1167 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1168 skb->slow_gro |= !!dst;
1169 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1170 }
1171
1172 /**
1173 * skb_dst_is_noref - Test if skb dst isn't refcounted
1174 * @skb: buffer
1175 */
skb_dst_is_noref(const struct sk_buff * skb)1176 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1177 {
1178 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1179 }
1180
1181 /* For mangling skb->pkt_type from user space side from applications
1182 * such as nft, tc, etc, we only allow a conservative subset of
1183 * possible pkt_types to be set.
1184 */
skb_pkt_type_ok(u32 ptype)1185 static inline bool skb_pkt_type_ok(u32 ptype)
1186 {
1187 return ptype <= PACKET_OTHERHOST;
1188 }
1189
1190 /**
1191 * skb_napi_id - Returns the skb's NAPI id
1192 * @skb: buffer
1193 */
skb_napi_id(const struct sk_buff * skb)1194 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1195 {
1196 #ifdef CONFIG_NET_RX_BUSY_POLL
1197 return skb->napi_id;
1198 #else
1199 return 0;
1200 #endif
1201 }
1202
skb_wifi_acked_valid(const struct sk_buff * skb)1203 static inline bool skb_wifi_acked_valid(const struct sk_buff *skb)
1204 {
1205 #ifdef CONFIG_WIRELESS
1206 return skb->wifi_acked_valid;
1207 #else
1208 return 0;
1209 #endif
1210 }
1211
1212 /**
1213 * skb_unref - decrement the skb's reference count
1214 * @skb: buffer
1215 *
1216 * Returns true if we can free the skb.
1217 */
skb_unref(struct sk_buff * skb)1218 static inline bool skb_unref(struct sk_buff *skb)
1219 {
1220 if (unlikely(!skb))
1221 return false;
1222 if (likely(refcount_read(&skb->users) == 1))
1223 smp_rmb();
1224 else if (likely(!refcount_dec_and_test(&skb->users)))
1225 return false;
1226
1227 return true;
1228 }
1229
skb_data_unref(const struct sk_buff * skb,struct skb_shared_info * shinfo)1230 static inline bool skb_data_unref(const struct sk_buff *skb,
1231 struct skb_shared_info *shinfo)
1232 {
1233 int bias;
1234
1235 if (!skb->cloned)
1236 return true;
1237
1238 bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1;
1239
1240 if (atomic_read(&shinfo->dataref) == bias)
1241 smp_rmb();
1242 else if (atomic_sub_return(bias, &shinfo->dataref))
1243 return false;
1244
1245 return true;
1246 }
1247
1248 void __fix_address
1249 kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason);
1250
1251 /**
1252 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1253 * @skb: buffer to free
1254 */
kfree_skb(struct sk_buff * skb)1255 static inline void kfree_skb(struct sk_buff *skb)
1256 {
1257 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
1258 }
1259
1260 void skb_release_head_state(struct sk_buff *skb);
1261 void kfree_skb_list_reason(struct sk_buff *segs,
1262 enum skb_drop_reason reason);
1263 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1264 void skb_tx_error(struct sk_buff *skb);
1265
kfree_skb_list(struct sk_buff * segs)1266 static inline void kfree_skb_list(struct sk_buff *segs)
1267 {
1268 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED);
1269 }
1270
1271 #ifdef CONFIG_TRACEPOINTS
1272 void consume_skb(struct sk_buff *skb);
1273 #else
consume_skb(struct sk_buff * skb)1274 static inline void consume_skb(struct sk_buff *skb)
1275 {
1276 return kfree_skb(skb);
1277 }
1278 #endif
1279
1280 void __consume_stateless_skb(struct sk_buff *skb);
1281 void __kfree_skb(struct sk_buff *skb);
1282
1283 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1284 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1285 bool *fragstolen, int *delta_truesize);
1286
1287 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1288 int node);
1289 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1290 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1291 struct sk_buff *build_skb_around(struct sk_buff *skb,
1292 void *data, unsigned int frag_size);
1293 void skb_attempt_defer_free(struct sk_buff *skb);
1294
1295 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1296 struct sk_buff *slab_build_skb(void *data);
1297
1298 /**
1299 * alloc_skb - allocate a network buffer
1300 * @size: size to allocate
1301 * @priority: allocation mask
1302 *
1303 * This function is a convenient wrapper around __alloc_skb().
1304 */
alloc_skb(unsigned int size,gfp_t priority)1305 static inline struct sk_buff *alloc_skb(unsigned int size,
1306 gfp_t priority)
1307 {
1308 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1309 }
1310
1311 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1312 unsigned long data_len,
1313 int max_page_order,
1314 int *errcode,
1315 gfp_t gfp_mask);
1316 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1317
1318 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1319 struct sk_buff_fclones {
1320 struct sk_buff skb1;
1321
1322 struct sk_buff skb2;
1323
1324 refcount_t fclone_ref;
1325 };
1326
1327 /**
1328 * skb_fclone_busy - check if fclone is busy
1329 * @sk: socket
1330 * @skb: buffer
1331 *
1332 * Returns true if skb is a fast clone, and its clone is not freed.
1333 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1334 * so we also check that didn't happen.
1335 */
skb_fclone_busy(const struct sock * sk,const struct sk_buff * skb)1336 static inline bool skb_fclone_busy(const struct sock *sk,
1337 const struct sk_buff *skb)
1338 {
1339 const struct sk_buff_fclones *fclones;
1340
1341 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1342
1343 return skb->fclone == SKB_FCLONE_ORIG &&
1344 refcount_read(&fclones->fclone_ref) > 1 &&
1345 READ_ONCE(fclones->skb2.sk) == sk;
1346 }
1347
1348 /**
1349 * alloc_skb_fclone - allocate a network buffer from fclone cache
1350 * @size: size to allocate
1351 * @priority: allocation mask
1352 *
1353 * This function is a convenient wrapper around __alloc_skb().
1354 */
alloc_skb_fclone(unsigned int size,gfp_t priority)1355 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1356 gfp_t priority)
1357 {
1358 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1359 }
1360
1361 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1362 void skb_headers_offset_update(struct sk_buff *skb, int off);
1363 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1364 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1365 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1366 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1367 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1368 gfp_t gfp_mask, bool fclone);
__pskb_copy(struct sk_buff * skb,int headroom,gfp_t gfp_mask)1369 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1370 gfp_t gfp_mask)
1371 {
1372 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1373 }
1374
1375 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1376 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1377 unsigned int headroom);
1378 struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom);
1379 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1380 int newtailroom, gfp_t priority);
1381 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1382 int offset, int len);
1383 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1384 int offset, int len);
1385 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1386 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1387
1388 /**
1389 * skb_pad - zero pad the tail of an skb
1390 * @skb: buffer to pad
1391 * @pad: space to pad
1392 *
1393 * Ensure that a buffer is followed by a padding area that is zero
1394 * filled. Used by network drivers which may DMA or transfer data
1395 * beyond the buffer end onto the wire.
1396 *
1397 * May return error in out of memory cases. The skb is freed on error.
1398 */
skb_pad(struct sk_buff * skb,int pad)1399 static inline int skb_pad(struct sk_buff *skb, int pad)
1400 {
1401 return __skb_pad(skb, pad, true);
1402 }
1403 #define dev_kfree_skb(a) consume_skb(a)
1404
1405 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1406 int offset, size_t size, size_t max_frags);
1407
1408 struct skb_seq_state {
1409 __u32 lower_offset;
1410 __u32 upper_offset;
1411 __u32 frag_idx;
1412 __u32 stepped_offset;
1413 struct sk_buff *root_skb;
1414 struct sk_buff *cur_skb;
1415 __u8 *frag_data;
1416 __u32 frag_off;
1417 };
1418
1419 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1420 unsigned int to, struct skb_seq_state *st);
1421 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1422 struct skb_seq_state *st);
1423 void skb_abort_seq_read(struct skb_seq_state *st);
1424
1425 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1426 unsigned int to, struct ts_config *config);
1427
1428 /*
1429 * Packet hash types specify the type of hash in skb_set_hash.
1430 *
1431 * Hash types refer to the protocol layer addresses which are used to
1432 * construct a packet's hash. The hashes are used to differentiate or identify
1433 * flows of the protocol layer for the hash type. Hash types are either
1434 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1435 *
1436 * Properties of hashes:
1437 *
1438 * 1) Two packets in different flows have different hash values
1439 * 2) Two packets in the same flow should have the same hash value
1440 *
1441 * A hash at a higher layer is considered to be more specific. A driver should
1442 * set the most specific hash possible.
1443 *
1444 * A driver cannot indicate a more specific hash than the layer at which a hash
1445 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1446 *
1447 * A driver may indicate a hash level which is less specific than the
1448 * actual layer the hash was computed on. For instance, a hash computed
1449 * at L4 may be considered an L3 hash. This should only be done if the
1450 * driver can't unambiguously determine that the HW computed the hash at
1451 * the higher layer. Note that the "should" in the second property above
1452 * permits this.
1453 */
1454 enum pkt_hash_types {
1455 PKT_HASH_TYPE_NONE, /* Undefined type */
1456 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1457 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1458 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1459 };
1460
skb_clear_hash(struct sk_buff * skb)1461 static inline void skb_clear_hash(struct sk_buff *skb)
1462 {
1463 skb->hash = 0;
1464 skb->sw_hash = 0;
1465 skb->l4_hash = 0;
1466 }
1467
skb_clear_hash_if_not_l4(struct sk_buff * skb)1468 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1469 {
1470 if (!skb->l4_hash)
1471 skb_clear_hash(skb);
1472 }
1473
1474 static inline void
__skb_set_hash(struct sk_buff * skb,__u32 hash,bool is_sw,bool is_l4)1475 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1476 {
1477 skb->l4_hash = is_l4;
1478 skb->sw_hash = is_sw;
1479 skb->hash = hash;
1480 }
1481
1482 static inline void
skb_set_hash(struct sk_buff * skb,__u32 hash,enum pkt_hash_types type)1483 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1484 {
1485 /* Used by drivers to set hash from HW */
1486 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1487 }
1488
1489 static inline void
__skb_set_sw_hash(struct sk_buff * skb,__u32 hash,bool is_l4)1490 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1491 {
1492 __skb_set_hash(skb, hash, true, is_l4);
1493 }
1494
1495 void __skb_get_hash(struct sk_buff *skb);
1496 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1497 u32 skb_get_poff(const struct sk_buff *skb);
1498 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1499 const struct flow_keys_basic *keys, int hlen);
1500 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1501 const void *data, int hlen_proto);
1502
skb_flow_get_ports(const struct sk_buff * skb,int thoff,u8 ip_proto)1503 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1504 int thoff, u8 ip_proto)
1505 {
1506 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1507 }
1508
1509 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1510 const struct flow_dissector_key *key,
1511 unsigned int key_count);
1512
1513 struct bpf_flow_dissector;
1514 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1515 __be16 proto, int nhoff, int hlen, unsigned int flags);
1516
1517 bool __skb_flow_dissect(const struct net *net,
1518 const struct sk_buff *skb,
1519 struct flow_dissector *flow_dissector,
1520 void *target_container, const void *data,
1521 __be16 proto, int nhoff, int hlen, unsigned int flags);
1522
skb_flow_dissect(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,unsigned int flags)1523 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1524 struct flow_dissector *flow_dissector,
1525 void *target_container, unsigned int flags)
1526 {
1527 return __skb_flow_dissect(NULL, skb, flow_dissector,
1528 target_container, NULL, 0, 0, 0, flags);
1529 }
1530
skb_flow_dissect_flow_keys(const struct sk_buff * skb,struct flow_keys * flow,unsigned int flags)1531 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1532 struct flow_keys *flow,
1533 unsigned int flags)
1534 {
1535 memset(flow, 0, sizeof(*flow));
1536 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1537 flow, NULL, 0, 0, 0, flags);
1538 }
1539
1540 static inline bool
skb_flow_dissect_flow_keys_basic(const struct net * net,const struct sk_buff * skb,struct flow_keys_basic * flow,const void * data,__be16 proto,int nhoff,int hlen,unsigned int flags)1541 skb_flow_dissect_flow_keys_basic(const struct net *net,
1542 const struct sk_buff *skb,
1543 struct flow_keys_basic *flow,
1544 const void *data, __be16 proto,
1545 int nhoff, int hlen, unsigned int flags)
1546 {
1547 memset(flow, 0, sizeof(*flow));
1548 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1549 data, proto, nhoff, hlen, flags);
1550 }
1551
1552 void skb_flow_dissect_meta(const struct sk_buff *skb,
1553 struct flow_dissector *flow_dissector,
1554 void *target_container);
1555
1556 /* Gets a skb connection tracking info, ctinfo map should be a
1557 * map of mapsize to translate enum ip_conntrack_info states
1558 * to user states.
1559 */
1560 void
1561 skb_flow_dissect_ct(const struct sk_buff *skb,
1562 struct flow_dissector *flow_dissector,
1563 void *target_container,
1564 u16 *ctinfo_map, size_t mapsize,
1565 bool post_ct, u16 zone);
1566 void
1567 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1568 struct flow_dissector *flow_dissector,
1569 void *target_container);
1570
1571 void skb_flow_dissect_hash(const struct sk_buff *skb,
1572 struct flow_dissector *flow_dissector,
1573 void *target_container);
1574
skb_get_hash(struct sk_buff * skb)1575 static inline __u32 skb_get_hash(struct sk_buff *skb)
1576 {
1577 if (!skb->l4_hash && !skb->sw_hash)
1578 __skb_get_hash(skb);
1579
1580 return skb->hash;
1581 }
1582
skb_get_hash_flowi6(struct sk_buff * skb,const struct flowi6 * fl6)1583 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1584 {
1585 if (!skb->l4_hash && !skb->sw_hash) {
1586 struct flow_keys keys;
1587 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1588
1589 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1590 }
1591
1592 return skb->hash;
1593 }
1594
1595 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1596 const siphash_key_t *perturb);
1597
skb_get_hash_raw(const struct sk_buff * skb)1598 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1599 {
1600 return skb->hash;
1601 }
1602
skb_copy_hash(struct sk_buff * to,const struct sk_buff * from)1603 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1604 {
1605 to->hash = from->hash;
1606 to->sw_hash = from->sw_hash;
1607 to->l4_hash = from->l4_hash;
1608 };
1609
skb_cmp_decrypted(const struct sk_buff * skb1,const struct sk_buff * skb2)1610 static inline int skb_cmp_decrypted(const struct sk_buff *skb1,
1611 const struct sk_buff *skb2)
1612 {
1613 #ifdef CONFIG_SKB_DECRYPTED
1614 return skb2->decrypted - skb1->decrypted;
1615 #else
1616 return 0;
1617 #endif
1618 }
1619
skb_is_decrypted(const struct sk_buff * skb)1620 static inline bool skb_is_decrypted(const struct sk_buff *skb)
1621 {
1622 #ifdef CONFIG_SKB_DECRYPTED
1623 return skb->decrypted;
1624 #else
1625 return false;
1626 #endif
1627 }
1628
skb_copy_decrypted(struct sk_buff * to,const struct sk_buff * from)1629 static inline void skb_copy_decrypted(struct sk_buff *to,
1630 const struct sk_buff *from)
1631 {
1632 #ifdef CONFIG_SKB_DECRYPTED
1633 to->decrypted = from->decrypted;
1634 #endif
1635 }
1636
1637 #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_end_pointer(const struct sk_buff * skb)1638 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1639 {
1640 return skb->head + skb->end;
1641 }
1642
skb_end_offset(const struct sk_buff * skb)1643 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1644 {
1645 return skb->end;
1646 }
1647
skb_set_end_offset(struct sk_buff * skb,unsigned int offset)1648 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1649 {
1650 skb->end = offset;
1651 }
1652 #else
skb_end_pointer(const struct sk_buff * skb)1653 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1654 {
1655 return skb->end;
1656 }
1657
skb_end_offset(const struct sk_buff * skb)1658 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1659 {
1660 return skb->end - skb->head;
1661 }
1662
skb_set_end_offset(struct sk_buff * skb,unsigned int offset)1663 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1664 {
1665 skb->end = skb->head + offset;
1666 }
1667 #endif
1668
1669 extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops;
1670
1671 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
1672 struct ubuf_info *uarg);
1673
1674 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1675
1676 int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
1677 struct sk_buff *skb, struct iov_iter *from,
1678 size_t length);
1679
skb_zerocopy_iter_dgram(struct sk_buff * skb,struct msghdr * msg,int len)1680 static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1681 struct msghdr *msg, int len)
1682 {
1683 return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len);
1684 }
1685
1686 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
1687 struct msghdr *msg, int len,
1688 struct ubuf_info *uarg);
1689
1690 /* Internal */
1691 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1692
skb_hwtstamps(struct sk_buff * skb)1693 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1694 {
1695 return &skb_shinfo(skb)->hwtstamps;
1696 }
1697
skb_zcopy(struct sk_buff * skb)1698 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1699 {
1700 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1701
1702 return is_zcopy ? skb_uarg(skb) : NULL;
1703 }
1704
skb_zcopy_pure(const struct sk_buff * skb)1705 static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1706 {
1707 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1708 }
1709
skb_zcopy_managed(const struct sk_buff * skb)1710 static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1711 {
1712 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1713 }
1714
skb_pure_zcopy_same(const struct sk_buff * skb1,const struct sk_buff * skb2)1715 static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1716 const struct sk_buff *skb2)
1717 {
1718 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
1719 }
1720
net_zcopy_get(struct ubuf_info * uarg)1721 static inline void net_zcopy_get(struct ubuf_info *uarg)
1722 {
1723 refcount_inc(&uarg->refcnt);
1724 }
1725
skb_zcopy_init(struct sk_buff * skb,struct ubuf_info * uarg)1726 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1727 {
1728 skb_shinfo(skb)->destructor_arg = uarg;
1729 skb_shinfo(skb)->flags |= uarg->flags;
1730 }
1731
skb_zcopy_set(struct sk_buff * skb,struct ubuf_info * uarg,bool * have_ref)1732 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1733 bool *have_ref)
1734 {
1735 if (skb && uarg && !skb_zcopy(skb)) {
1736 if (unlikely(have_ref && *have_ref))
1737 *have_ref = false;
1738 else
1739 net_zcopy_get(uarg);
1740 skb_zcopy_init(skb, uarg);
1741 }
1742 }
1743
skb_zcopy_set_nouarg(struct sk_buff * skb,void * val)1744 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1745 {
1746 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1747 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1748 }
1749
skb_zcopy_is_nouarg(struct sk_buff * skb)1750 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1751 {
1752 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1753 }
1754
skb_zcopy_get_nouarg(struct sk_buff * skb)1755 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1756 {
1757 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1758 }
1759
net_zcopy_put(struct ubuf_info * uarg)1760 static inline void net_zcopy_put(struct ubuf_info *uarg)
1761 {
1762 if (uarg)
1763 uarg->ops->complete(NULL, uarg, true);
1764 }
1765
net_zcopy_put_abort(struct ubuf_info * uarg,bool have_uref)1766 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1767 {
1768 if (uarg) {
1769 if (uarg->ops == &msg_zerocopy_ubuf_ops)
1770 msg_zerocopy_put_abort(uarg, have_uref);
1771 else if (have_uref)
1772 net_zcopy_put(uarg);
1773 }
1774 }
1775
1776 /* Release a reference on a zerocopy structure */
skb_zcopy_clear(struct sk_buff * skb,bool zerocopy_success)1777 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1778 {
1779 struct ubuf_info *uarg = skb_zcopy(skb);
1780
1781 if (uarg) {
1782 if (!skb_zcopy_is_nouarg(skb))
1783 uarg->ops->complete(skb, uarg, zerocopy_success);
1784
1785 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1786 }
1787 }
1788
1789 void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1790
skb_zcopy_downgrade_managed(struct sk_buff * skb)1791 static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1792 {
1793 if (unlikely(skb_zcopy_managed(skb)))
1794 __skb_zcopy_downgrade_managed(skb);
1795 }
1796
skb_mark_not_on_list(struct sk_buff * skb)1797 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1798 {
1799 skb->next = NULL;
1800 }
1801
skb_poison_list(struct sk_buff * skb)1802 static inline void skb_poison_list(struct sk_buff *skb)
1803 {
1804 #ifdef CONFIG_DEBUG_NET
1805 skb->next = SKB_LIST_POISON_NEXT;
1806 #endif
1807 }
1808
1809 /* Iterate through singly-linked GSO fragments of an skb. */
1810 #define skb_list_walk_safe(first, skb, next_skb) \
1811 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1812 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1813
skb_list_del_init(struct sk_buff * skb)1814 static inline void skb_list_del_init(struct sk_buff *skb)
1815 {
1816 __list_del_entry(&skb->list);
1817 skb_mark_not_on_list(skb);
1818 }
1819
1820 /**
1821 * skb_queue_empty - check if a queue is empty
1822 * @list: queue head
1823 *
1824 * Returns true if the queue is empty, false otherwise.
1825 */
skb_queue_empty(const struct sk_buff_head * list)1826 static inline int skb_queue_empty(const struct sk_buff_head *list)
1827 {
1828 return list->next == (const struct sk_buff *) list;
1829 }
1830
1831 /**
1832 * skb_queue_empty_lockless - check if a queue is empty
1833 * @list: queue head
1834 *
1835 * Returns true if the queue is empty, false otherwise.
1836 * This variant can be used in lockless contexts.
1837 */
skb_queue_empty_lockless(const struct sk_buff_head * list)1838 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1839 {
1840 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1841 }
1842
1843
1844 /**
1845 * skb_queue_is_last - check if skb is the last entry in the queue
1846 * @list: queue head
1847 * @skb: buffer
1848 *
1849 * Returns true if @skb is the last buffer on the list.
1850 */
skb_queue_is_last(const struct sk_buff_head * list,const struct sk_buff * skb)1851 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1852 const struct sk_buff *skb)
1853 {
1854 return skb->next == (const struct sk_buff *) list;
1855 }
1856
1857 /**
1858 * skb_queue_is_first - check if skb is the first entry in the queue
1859 * @list: queue head
1860 * @skb: buffer
1861 *
1862 * Returns true if @skb is the first buffer on the list.
1863 */
skb_queue_is_first(const struct sk_buff_head * list,const struct sk_buff * skb)1864 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1865 const struct sk_buff *skb)
1866 {
1867 return skb->prev == (const struct sk_buff *) list;
1868 }
1869
1870 /**
1871 * skb_queue_next - return the next packet in the queue
1872 * @list: queue head
1873 * @skb: current buffer
1874 *
1875 * Return the next packet in @list after @skb. It is only valid to
1876 * call this if skb_queue_is_last() evaluates to false.
1877 */
skb_queue_next(const struct sk_buff_head * list,const struct sk_buff * skb)1878 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1879 const struct sk_buff *skb)
1880 {
1881 /* This BUG_ON may seem severe, but if we just return then we
1882 * are going to dereference garbage.
1883 */
1884 BUG_ON(skb_queue_is_last(list, skb));
1885 return skb->next;
1886 }
1887
1888 /**
1889 * skb_queue_prev - return the prev packet in the queue
1890 * @list: queue head
1891 * @skb: current buffer
1892 *
1893 * Return the prev packet in @list before @skb. It is only valid to
1894 * call this if skb_queue_is_first() evaluates to false.
1895 */
skb_queue_prev(const struct sk_buff_head * list,const struct sk_buff * skb)1896 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1897 const struct sk_buff *skb)
1898 {
1899 /* This BUG_ON may seem severe, but if we just return then we
1900 * are going to dereference garbage.
1901 */
1902 BUG_ON(skb_queue_is_first(list, skb));
1903 return skb->prev;
1904 }
1905
1906 /**
1907 * skb_get - reference buffer
1908 * @skb: buffer to reference
1909 *
1910 * Makes another reference to a socket buffer and returns a pointer
1911 * to the buffer.
1912 */
skb_get(struct sk_buff * skb)1913 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1914 {
1915 refcount_inc(&skb->users);
1916 return skb;
1917 }
1918
1919 /*
1920 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1921 */
1922
1923 /**
1924 * skb_cloned - is the buffer a clone
1925 * @skb: buffer to check
1926 *
1927 * Returns true if the buffer was generated with skb_clone() and is
1928 * one of multiple shared copies of the buffer. Cloned buffers are
1929 * shared data so must not be written to under normal circumstances.
1930 */
skb_cloned(const struct sk_buff * skb)1931 static inline int skb_cloned(const struct sk_buff *skb)
1932 {
1933 return skb->cloned &&
1934 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1935 }
1936
skb_unclone(struct sk_buff * skb,gfp_t pri)1937 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1938 {
1939 might_sleep_if(gfpflags_allow_blocking(pri));
1940
1941 if (skb_cloned(skb))
1942 return pskb_expand_head(skb, 0, 0, pri);
1943
1944 return 0;
1945 }
1946
1947 /* This variant of skb_unclone() makes sure skb->truesize
1948 * and skb_end_offset() are not changed, whenever a new skb->head is needed.
1949 *
1950 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
1951 * when various debugging features are in place.
1952 */
1953 int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
skb_unclone_keeptruesize(struct sk_buff * skb,gfp_t pri)1954 static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
1955 {
1956 might_sleep_if(gfpflags_allow_blocking(pri));
1957
1958 if (skb_cloned(skb))
1959 return __skb_unclone_keeptruesize(skb, pri);
1960 return 0;
1961 }
1962
1963 /**
1964 * skb_header_cloned - is the header a clone
1965 * @skb: buffer to check
1966 *
1967 * Returns true if modifying the header part of the buffer requires
1968 * the data to be copied.
1969 */
skb_header_cloned(const struct sk_buff * skb)1970 static inline int skb_header_cloned(const struct sk_buff *skb)
1971 {
1972 int dataref;
1973
1974 if (!skb->cloned)
1975 return 0;
1976
1977 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1978 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1979 return dataref != 1;
1980 }
1981
skb_header_unclone(struct sk_buff * skb,gfp_t pri)1982 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1983 {
1984 might_sleep_if(gfpflags_allow_blocking(pri));
1985
1986 if (skb_header_cloned(skb))
1987 return pskb_expand_head(skb, 0, 0, pri);
1988
1989 return 0;
1990 }
1991
1992 /**
1993 * __skb_header_release() - allow clones to use the headroom
1994 * @skb: buffer to operate on
1995 *
1996 * See "DOC: dataref and headerless skbs".
1997 */
__skb_header_release(struct sk_buff * skb)1998 static inline void __skb_header_release(struct sk_buff *skb)
1999 {
2000 skb->nohdr = 1;
2001 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
2002 }
2003
2004
2005 /**
2006 * skb_shared - is the buffer shared
2007 * @skb: buffer to check
2008 *
2009 * Returns true if more than one person has a reference to this
2010 * buffer.
2011 */
skb_shared(const struct sk_buff * skb)2012 static inline int skb_shared(const struct sk_buff *skb)
2013 {
2014 return refcount_read(&skb->users) != 1;
2015 }
2016
2017 /**
2018 * skb_share_check - check if buffer is shared and if so clone it
2019 * @skb: buffer to check
2020 * @pri: priority for memory allocation
2021 *
2022 * If the buffer is shared the buffer is cloned and the old copy
2023 * drops a reference. A new clone with a single reference is returned.
2024 * If the buffer is not shared the original buffer is returned. When
2025 * being called from interrupt status or with spinlocks held pri must
2026 * be GFP_ATOMIC.
2027 *
2028 * NULL is returned on a memory allocation failure.
2029 */
skb_share_check(struct sk_buff * skb,gfp_t pri)2030 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
2031 {
2032 might_sleep_if(gfpflags_allow_blocking(pri));
2033 if (skb_shared(skb)) {
2034 struct sk_buff *nskb = skb_clone(skb, pri);
2035
2036 if (likely(nskb))
2037 consume_skb(skb);
2038 else
2039 kfree_skb(skb);
2040 skb = nskb;
2041 }
2042 return skb;
2043 }
2044
2045 /*
2046 * Copy shared buffers into a new sk_buff. We effectively do COW on
2047 * packets to handle cases where we have a local reader and forward
2048 * and a couple of other messy ones. The normal one is tcpdumping
2049 * a packet that's being forwarded.
2050 */
2051
2052 /**
2053 * skb_unshare - make a copy of a shared buffer
2054 * @skb: buffer to check
2055 * @pri: priority for memory allocation
2056 *
2057 * If the socket buffer is a clone then this function creates a new
2058 * copy of the data, drops a reference count on the old copy and returns
2059 * the new copy with the reference count at 1. If the buffer is not a clone
2060 * the original buffer is returned. When called with a spinlock held or
2061 * from interrupt state @pri must be %GFP_ATOMIC
2062 *
2063 * %NULL is returned on a memory allocation failure.
2064 */
skb_unshare(struct sk_buff * skb,gfp_t pri)2065 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
2066 gfp_t pri)
2067 {
2068 might_sleep_if(gfpflags_allow_blocking(pri));
2069 if (skb_cloned(skb)) {
2070 struct sk_buff *nskb = skb_copy(skb, pri);
2071
2072 /* Free our shared copy */
2073 if (likely(nskb))
2074 consume_skb(skb);
2075 else
2076 kfree_skb(skb);
2077 skb = nskb;
2078 }
2079 return skb;
2080 }
2081
2082 /**
2083 * skb_peek - peek at the head of an &sk_buff_head
2084 * @list_: list to peek at
2085 *
2086 * Peek an &sk_buff. Unlike most other operations you _MUST_
2087 * be careful with this one. A peek leaves the buffer on the
2088 * list and someone else may run off with it. You must hold
2089 * the appropriate locks or have a private queue to do this.
2090 *
2091 * Returns %NULL for an empty list or a pointer to the head element.
2092 * The reference count is not incremented and the reference is therefore
2093 * volatile. Use with caution.
2094 */
skb_peek(const struct sk_buff_head * list_)2095 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
2096 {
2097 struct sk_buff *skb = list_->next;
2098
2099 if (skb == (struct sk_buff *)list_)
2100 skb = NULL;
2101 return skb;
2102 }
2103
2104 /**
2105 * __skb_peek - peek at the head of a non-empty &sk_buff_head
2106 * @list_: list to peek at
2107 *
2108 * Like skb_peek(), but the caller knows that the list is not empty.
2109 */
__skb_peek(const struct sk_buff_head * list_)2110 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
2111 {
2112 return list_->next;
2113 }
2114
2115 /**
2116 * skb_peek_next - peek skb following the given one from a queue
2117 * @skb: skb to start from
2118 * @list_: list to peek at
2119 *
2120 * Returns %NULL when the end of the list is met or a pointer to the
2121 * next element. The reference count is not incremented and the
2122 * reference is therefore volatile. Use with caution.
2123 */
skb_peek_next(struct sk_buff * skb,const struct sk_buff_head * list_)2124 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
2125 const struct sk_buff_head *list_)
2126 {
2127 struct sk_buff *next = skb->next;
2128
2129 if (next == (struct sk_buff *)list_)
2130 next = NULL;
2131 return next;
2132 }
2133
2134 /**
2135 * skb_peek_tail - peek at the tail of an &sk_buff_head
2136 * @list_: list to peek at
2137 *
2138 * Peek an &sk_buff. Unlike most other operations you _MUST_
2139 * be careful with this one. A peek leaves the buffer on the
2140 * list and someone else may run off with it. You must hold
2141 * the appropriate locks or have a private queue to do this.
2142 *
2143 * Returns %NULL for an empty list or a pointer to the tail element.
2144 * The reference count is not incremented and the reference is therefore
2145 * volatile. Use with caution.
2146 */
skb_peek_tail(const struct sk_buff_head * list_)2147 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
2148 {
2149 struct sk_buff *skb = READ_ONCE(list_->prev);
2150
2151 if (skb == (struct sk_buff *)list_)
2152 skb = NULL;
2153 return skb;
2154
2155 }
2156
2157 /**
2158 * skb_queue_len - get queue length
2159 * @list_: list to measure
2160 *
2161 * Return the length of an &sk_buff queue.
2162 */
skb_queue_len(const struct sk_buff_head * list_)2163 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2164 {
2165 return list_->qlen;
2166 }
2167
2168 /**
2169 * skb_queue_len_lockless - get queue length
2170 * @list_: list to measure
2171 *
2172 * Return the length of an &sk_buff queue.
2173 * This variant can be used in lockless contexts.
2174 */
skb_queue_len_lockless(const struct sk_buff_head * list_)2175 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2176 {
2177 return READ_ONCE(list_->qlen);
2178 }
2179
2180 /**
2181 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2182 * @list: queue to initialize
2183 *
2184 * This initializes only the list and queue length aspects of
2185 * an sk_buff_head object. This allows to initialize the list
2186 * aspects of an sk_buff_head without reinitializing things like
2187 * the spinlock. It can also be used for on-stack sk_buff_head
2188 * objects where the spinlock is known to not be used.
2189 */
__skb_queue_head_init(struct sk_buff_head * list)2190 static inline void __skb_queue_head_init(struct sk_buff_head *list)
2191 {
2192 list->prev = list->next = (struct sk_buff *)list;
2193 list->qlen = 0;
2194 }
2195
2196 /*
2197 * This function creates a split out lock class for each invocation;
2198 * this is needed for now since a whole lot of users of the skb-queue
2199 * infrastructure in drivers have different locking usage (in hardirq)
2200 * than the networking core (in softirq only). In the long run either the
2201 * network layer or drivers should need annotation to consolidate the
2202 * main types of usage into 3 classes.
2203 */
skb_queue_head_init(struct sk_buff_head * list)2204 static inline void skb_queue_head_init(struct sk_buff_head *list)
2205 {
2206 spin_lock_init(&list->lock);
2207 __skb_queue_head_init(list);
2208 }
2209
skb_queue_head_init_class(struct sk_buff_head * list,struct lock_class_key * class)2210 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2211 struct lock_class_key *class)
2212 {
2213 skb_queue_head_init(list);
2214 lockdep_set_class(&list->lock, class);
2215 }
2216
2217 /*
2218 * Insert an sk_buff on a list.
2219 *
2220 * The "__skb_xxxx()" functions are the non-atomic ones that
2221 * can only be called with interrupts disabled.
2222 */
__skb_insert(struct sk_buff * newsk,struct sk_buff * prev,struct sk_buff * next,struct sk_buff_head * list)2223 static inline void __skb_insert(struct sk_buff *newsk,
2224 struct sk_buff *prev, struct sk_buff *next,
2225 struct sk_buff_head *list)
2226 {
2227 /* See skb_queue_empty_lockless() and skb_peek_tail()
2228 * for the opposite READ_ONCE()
2229 */
2230 WRITE_ONCE(newsk->next, next);
2231 WRITE_ONCE(newsk->prev, prev);
2232 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2233 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2234 WRITE_ONCE(list->qlen, list->qlen + 1);
2235 }
2236
__skb_queue_splice(const struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * next)2237 static inline void __skb_queue_splice(const struct sk_buff_head *list,
2238 struct sk_buff *prev,
2239 struct sk_buff *next)
2240 {
2241 struct sk_buff *first = list->next;
2242 struct sk_buff *last = list->prev;
2243
2244 WRITE_ONCE(first->prev, prev);
2245 WRITE_ONCE(prev->next, first);
2246
2247 WRITE_ONCE(last->next, next);
2248 WRITE_ONCE(next->prev, last);
2249 }
2250
2251 /**
2252 * skb_queue_splice - join two skb lists, this is designed for stacks
2253 * @list: the new list to add
2254 * @head: the place to add it in the first list
2255 */
skb_queue_splice(const struct sk_buff_head * list,struct sk_buff_head * head)2256 static inline void skb_queue_splice(const struct sk_buff_head *list,
2257 struct sk_buff_head *head)
2258 {
2259 if (!skb_queue_empty(list)) {
2260 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2261 head->qlen += list->qlen;
2262 }
2263 }
2264
2265 /**
2266 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2267 * @list: the new list to add
2268 * @head: the place to add it in the first list
2269 *
2270 * The list at @list is reinitialised
2271 */
skb_queue_splice_init(struct sk_buff_head * list,struct sk_buff_head * head)2272 static inline void skb_queue_splice_init(struct sk_buff_head *list,
2273 struct sk_buff_head *head)
2274 {
2275 if (!skb_queue_empty(list)) {
2276 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2277 head->qlen += list->qlen;
2278 __skb_queue_head_init(list);
2279 }
2280 }
2281
2282 /**
2283 * skb_queue_splice_tail - join two skb lists, each list being a queue
2284 * @list: the new list to add
2285 * @head: the place to add it in the first list
2286 */
skb_queue_splice_tail(const struct sk_buff_head * list,struct sk_buff_head * head)2287 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2288 struct sk_buff_head *head)
2289 {
2290 if (!skb_queue_empty(list)) {
2291 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2292 head->qlen += list->qlen;
2293 }
2294 }
2295
2296 /**
2297 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2298 * @list: the new list to add
2299 * @head: the place to add it in the first list
2300 *
2301 * Each of the lists is a queue.
2302 * The list at @list is reinitialised
2303 */
skb_queue_splice_tail_init(struct sk_buff_head * list,struct sk_buff_head * head)2304 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2305 struct sk_buff_head *head)
2306 {
2307 if (!skb_queue_empty(list)) {
2308 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2309 head->qlen += list->qlen;
2310 __skb_queue_head_init(list);
2311 }
2312 }
2313
2314 /**
2315 * __skb_queue_after - queue a buffer at the list head
2316 * @list: list to use
2317 * @prev: place after this buffer
2318 * @newsk: buffer to queue
2319 *
2320 * Queue a buffer int the middle of a list. This function takes no locks
2321 * and you must therefore hold required locks before calling it.
2322 *
2323 * A buffer cannot be placed on two lists at the same time.
2324 */
__skb_queue_after(struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * newsk)2325 static inline void __skb_queue_after(struct sk_buff_head *list,
2326 struct sk_buff *prev,
2327 struct sk_buff *newsk)
2328 {
2329 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list);
2330 }
2331
2332 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2333 struct sk_buff_head *list);
2334
__skb_queue_before(struct sk_buff_head * list,struct sk_buff * next,struct sk_buff * newsk)2335 static inline void __skb_queue_before(struct sk_buff_head *list,
2336 struct sk_buff *next,
2337 struct sk_buff *newsk)
2338 {
2339 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list);
2340 }
2341
2342 /**
2343 * __skb_queue_head - queue a buffer at the list head
2344 * @list: list to use
2345 * @newsk: buffer to queue
2346 *
2347 * Queue a buffer at the start of a list. This function takes no locks
2348 * and you must therefore hold required locks before calling it.
2349 *
2350 * A buffer cannot be placed on two lists at the same time.
2351 */
__skb_queue_head(struct sk_buff_head * list,struct sk_buff * newsk)2352 static inline void __skb_queue_head(struct sk_buff_head *list,
2353 struct sk_buff *newsk)
2354 {
2355 __skb_queue_after(list, (struct sk_buff *)list, newsk);
2356 }
2357 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2358
2359 /**
2360 * __skb_queue_tail - queue a buffer at the list tail
2361 * @list: list to use
2362 * @newsk: buffer to queue
2363 *
2364 * Queue a buffer at the end of a list. This function takes no locks
2365 * and you must therefore hold required locks before calling it.
2366 *
2367 * A buffer cannot be placed on two lists at the same time.
2368 */
__skb_queue_tail(struct sk_buff_head * list,struct sk_buff * newsk)2369 static inline void __skb_queue_tail(struct sk_buff_head *list,
2370 struct sk_buff *newsk)
2371 {
2372 __skb_queue_before(list, (struct sk_buff *)list, newsk);
2373 }
2374 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2375
2376 /*
2377 * remove sk_buff from list. _Must_ be called atomically, and with
2378 * the list known..
2379 */
2380 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
__skb_unlink(struct sk_buff * skb,struct sk_buff_head * list)2381 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2382 {
2383 struct sk_buff *next, *prev;
2384
2385 WRITE_ONCE(list->qlen, list->qlen - 1);
2386 next = skb->next;
2387 prev = skb->prev;
2388 skb->next = skb->prev = NULL;
2389 WRITE_ONCE(next->prev, prev);
2390 WRITE_ONCE(prev->next, next);
2391 }
2392
2393 /**
2394 * __skb_dequeue - remove from the head of the queue
2395 * @list: list to dequeue from
2396 *
2397 * Remove the head of the list. This function does not take any locks
2398 * so must be used with appropriate locks held only. The head item is
2399 * returned or %NULL if the list is empty.
2400 */
__skb_dequeue(struct sk_buff_head * list)2401 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2402 {
2403 struct sk_buff *skb = skb_peek(list);
2404 if (skb)
2405 __skb_unlink(skb, list);
2406 return skb;
2407 }
2408 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2409
2410 /**
2411 * __skb_dequeue_tail - remove from the tail of the queue
2412 * @list: list to dequeue from
2413 *
2414 * Remove the tail of the list. This function does not take any locks
2415 * so must be used with appropriate locks held only. The tail item is
2416 * returned or %NULL if the list is empty.
2417 */
__skb_dequeue_tail(struct sk_buff_head * list)2418 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2419 {
2420 struct sk_buff *skb = skb_peek_tail(list);
2421 if (skb)
2422 __skb_unlink(skb, list);
2423 return skb;
2424 }
2425 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2426
2427
skb_is_nonlinear(const struct sk_buff * skb)2428 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2429 {
2430 return skb->data_len;
2431 }
2432
skb_headlen(const struct sk_buff * skb)2433 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2434 {
2435 return skb->len - skb->data_len;
2436 }
2437
__skb_pagelen(const struct sk_buff * skb)2438 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2439 {
2440 unsigned int i, len = 0;
2441
2442 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2443 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2444 return len;
2445 }
2446
skb_pagelen(const struct sk_buff * skb)2447 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2448 {
2449 return skb_headlen(skb) + __skb_pagelen(skb);
2450 }
2451
skb_frag_fill_netmem_desc(skb_frag_t * frag,netmem_ref netmem,int off,int size)2452 static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag,
2453 netmem_ref netmem, int off,
2454 int size)
2455 {
2456 frag->netmem = netmem;
2457 frag->offset = off;
2458 skb_frag_size_set(frag, size);
2459 }
2460
skb_frag_fill_page_desc(skb_frag_t * frag,struct page * page,int off,int size)2461 static inline void skb_frag_fill_page_desc(skb_frag_t *frag,
2462 struct page *page,
2463 int off, int size)
2464 {
2465 skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size);
2466 }
2467
__skb_fill_netmem_desc_noacc(struct skb_shared_info * shinfo,int i,netmem_ref netmem,int off,int size)2468 static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo,
2469 int i, netmem_ref netmem,
2470 int off, int size)
2471 {
2472 skb_frag_t *frag = &shinfo->frags[i];
2473
2474 skb_frag_fill_netmem_desc(frag, netmem, off, size);
2475 }
2476
__skb_fill_page_desc_noacc(struct skb_shared_info * shinfo,int i,struct page * page,int off,int size)2477 static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2478 int i, struct page *page,
2479 int off, int size)
2480 {
2481 __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off,
2482 size);
2483 }
2484
2485 /**
2486 * skb_len_add - adds a number to len fields of skb
2487 * @skb: buffer to add len to
2488 * @delta: number of bytes to add
2489 */
skb_len_add(struct sk_buff * skb,int delta)2490 static inline void skb_len_add(struct sk_buff *skb, int delta)
2491 {
2492 skb->len += delta;
2493 skb->data_len += delta;
2494 skb->truesize += delta;
2495 }
2496
2497 /**
2498 * __skb_fill_netmem_desc - initialise a fragment in an skb
2499 * @skb: buffer containing fragment to be initialised
2500 * @i: fragment index to initialise
2501 * @netmem: the netmem to use for this fragment
2502 * @off: the offset to the data with @page
2503 * @size: the length of the data
2504 *
2505 * Initialises the @i'th fragment of @skb to point to &size bytes at
2506 * offset @off within @page.
2507 *
2508 * Does not take any additional reference on the fragment.
2509 */
__skb_fill_netmem_desc(struct sk_buff * skb,int i,netmem_ref netmem,int off,int size)2510 static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i,
2511 netmem_ref netmem, int off, int size)
2512 {
2513 struct page *page = netmem_to_page(netmem);
2514
2515 __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size);
2516
2517 /* Propagate page pfmemalloc to the skb if we can. The problem is
2518 * that not all callers have unique ownership of the page but rely
2519 * on page_is_pfmemalloc doing the right thing(tm).
2520 */
2521 page = compound_head(page);
2522 if (page_is_pfmemalloc(page))
2523 skb->pfmemalloc = true;
2524 }
2525
__skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2526 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2527 struct page *page, int off, int size)
2528 {
2529 __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2530 }
2531
skb_fill_netmem_desc(struct sk_buff * skb,int i,netmem_ref netmem,int off,int size)2532 static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i,
2533 netmem_ref netmem, int off, int size)
2534 {
2535 __skb_fill_netmem_desc(skb, i, netmem, off, size);
2536 skb_shinfo(skb)->nr_frags = i + 1;
2537 }
2538
2539 /**
2540 * skb_fill_page_desc - initialise a paged fragment in an skb
2541 * @skb: buffer containing fragment to be initialised
2542 * @i: paged fragment index to initialise
2543 * @page: the page to use for this fragment
2544 * @off: the offset to the data with @page
2545 * @size: the length of the data
2546 *
2547 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2548 * @skb to point to @size bytes at offset @off within @page. In
2549 * addition updates @skb such that @i is the last fragment.
2550 *
2551 * Does not take any additional reference on the fragment.
2552 */
skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2553 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2554 struct page *page, int off, int size)
2555 {
2556 skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size);
2557 }
2558
2559 /**
2560 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb
2561 * @skb: buffer containing fragment to be initialised
2562 * @i: paged fragment index to initialise
2563 * @page: the page to use for this fragment
2564 * @off: the offset to the data with @page
2565 * @size: the length of the data
2566 *
2567 * Variant of skb_fill_page_desc() which does not deal with
2568 * pfmemalloc, if page is not owned by us.
2569 */
skb_fill_page_desc_noacc(struct sk_buff * skb,int i,struct page * page,int off,int size)2570 static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i,
2571 struct page *page, int off,
2572 int size)
2573 {
2574 struct skb_shared_info *shinfo = skb_shinfo(skb);
2575
2576 __skb_fill_page_desc_noacc(shinfo, i, page, off, size);
2577 shinfo->nr_frags = i + 1;
2578 }
2579
2580 void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem,
2581 int off, int size, unsigned int truesize);
2582
skb_add_rx_frag(struct sk_buff * skb,int i,struct page * page,int off,int size,unsigned int truesize)2583 static inline void skb_add_rx_frag(struct sk_buff *skb, int i,
2584 struct page *page, int off, int size,
2585 unsigned int truesize)
2586 {
2587 skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size,
2588 truesize);
2589 }
2590
2591 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2592 unsigned int truesize);
2593
2594 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2595
2596 #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_tail_pointer(const struct sk_buff * skb)2597 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2598 {
2599 return skb->head + skb->tail;
2600 }
2601
skb_reset_tail_pointer(struct sk_buff * skb)2602 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2603 {
2604 skb->tail = skb->data - skb->head;
2605 }
2606
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2607 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2608 {
2609 skb_reset_tail_pointer(skb);
2610 skb->tail += offset;
2611 }
2612
2613 #else /* NET_SKBUFF_DATA_USES_OFFSET */
skb_tail_pointer(const struct sk_buff * skb)2614 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2615 {
2616 return skb->tail;
2617 }
2618
skb_reset_tail_pointer(struct sk_buff * skb)2619 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2620 {
2621 skb->tail = skb->data;
2622 }
2623
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2624 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2625 {
2626 skb->tail = skb->data + offset;
2627 }
2628
2629 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2630
skb_assert_len(struct sk_buff * skb)2631 static inline void skb_assert_len(struct sk_buff *skb)
2632 {
2633 #ifdef CONFIG_DEBUG_NET
2634 if (WARN_ONCE(!skb->len, "%s\n", __func__))
2635 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2636 #endif /* CONFIG_DEBUG_NET */
2637 }
2638
2639 /*
2640 * Add data to an sk_buff
2641 */
2642 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2643 void *skb_put(struct sk_buff *skb, unsigned int len);
__skb_put(struct sk_buff * skb,unsigned int len)2644 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2645 {
2646 void *tmp = skb_tail_pointer(skb);
2647 SKB_LINEAR_ASSERT(skb);
2648 skb->tail += len;
2649 skb->len += len;
2650 return tmp;
2651 }
2652
__skb_put_zero(struct sk_buff * skb,unsigned int len)2653 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2654 {
2655 void *tmp = __skb_put(skb, len);
2656
2657 memset(tmp, 0, len);
2658 return tmp;
2659 }
2660
__skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2661 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2662 unsigned int len)
2663 {
2664 void *tmp = __skb_put(skb, len);
2665
2666 memcpy(tmp, data, len);
2667 return tmp;
2668 }
2669
__skb_put_u8(struct sk_buff * skb,u8 val)2670 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2671 {
2672 *(u8 *)__skb_put(skb, 1) = val;
2673 }
2674
skb_put_zero(struct sk_buff * skb,unsigned int len)2675 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2676 {
2677 void *tmp = skb_put(skb, len);
2678
2679 memset(tmp, 0, len);
2680
2681 return tmp;
2682 }
2683
skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2684 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2685 unsigned int len)
2686 {
2687 void *tmp = skb_put(skb, len);
2688
2689 memcpy(tmp, data, len);
2690
2691 return tmp;
2692 }
2693
skb_put_u8(struct sk_buff * skb,u8 val)2694 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2695 {
2696 *(u8 *)skb_put(skb, 1) = val;
2697 }
2698
2699 void *skb_push(struct sk_buff *skb, unsigned int len);
__skb_push(struct sk_buff * skb,unsigned int len)2700 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2701 {
2702 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2703
2704 skb->data -= len;
2705 skb->len += len;
2706 return skb->data;
2707 }
2708
2709 void *skb_pull(struct sk_buff *skb, unsigned int len);
__skb_pull(struct sk_buff * skb,unsigned int len)2710 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2711 {
2712 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2713
2714 skb->len -= len;
2715 if (unlikely(skb->len < skb->data_len)) {
2716 #if defined(CONFIG_DEBUG_NET)
2717 skb->len += len;
2718 pr_err("__skb_pull(len=%u)\n", len);
2719 skb_dump(KERN_ERR, skb, false);
2720 #endif
2721 BUG();
2722 }
2723 return skb->data += len;
2724 }
2725
skb_pull_inline(struct sk_buff * skb,unsigned int len)2726 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2727 {
2728 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2729 }
2730
2731 void *skb_pull_data(struct sk_buff *skb, size_t len);
2732
2733 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2734
2735 static inline enum skb_drop_reason
pskb_may_pull_reason(struct sk_buff * skb,unsigned int len)2736 pskb_may_pull_reason(struct sk_buff *skb, unsigned int len)
2737 {
2738 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX);
2739
2740 if (likely(len <= skb_headlen(skb)))
2741 return SKB_NOT_DROPPED_YET;
2742
2743 if (unlikely(len > skb->len))
2744 return SKB_DROP_REASON_PKT_TOO_SMALL;
2745
2746 if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb))))
2747 return SKB_DROP_REASON_NOMEM;
2748
2749 return SKB_NOT_DROPPED_YET;
2750 }
2751
pskb_may_pull(struct sk_buff * skb,unsigned int len)2752 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2753 {
2754 return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET;
2755 }
2756
pskb_pull(struct sk_buff * skb,unsigned int len)2757 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2758 {
2759 if (!pskb_may_pull(skb, len))
2760 return NULL;
2761
2762 skb->len -= len;
2763 return skb->data += len;
2764 }
2765
2766 void skb_condense(struct sk_buff *skb);
2767
2768 /**
2769 * skb_headroom - bytes at buffer head
2770 * @skb: buffer to check
2771 *
2772 * Return the number of bytes of free space at the head of an &sk_buff.
2773 */
skb_headroom(const struct sk_buff * skb)2774 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2775 {
2776 return skb->data - skb->head;
2777 }
2778
2779 /**
2780 * skb_tailroom - bytes at buffer end
2781 * @skb: buffer to check
2782 *
2783 * Return the number of bytes of free space at the tail of an sk_buff
2784 */
skb_tailroom(const struct sk_buff * skb)2785 static inline int skb_tailroom(const struct sk_buff *skb)
2786 {
2787 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2788 }
2789
2790 /**
2791 * skb_availroom - bytes at buffer end
2792 * @skb: buffer to check
2793 *
2794 * Return the number of bytes of free space at the tail of an sk_buff
2795 * allocated by sk_stream_alloc()
2796 */
skb_availroom(const struct sk_buff * skb)2797 static inline int skb_availroom(const struct sk_buff *skb)
2798 {
2799 if (skb_is_nonlinear(skb))
2800 return 0;
2801
2802 return skb->end - skb->tail - skb->reserved_tailroom;
2803 }
2804
2805 /**
2806 * skb_reserve - adjust headroom
2807 * @skb: buffer to alter
2808 * @len: bytes to move
2809 *
2810 * Increase the headroom of an empty &sk_buff by reducing the tail
2811 * room. This is only allowed for an empty buffer.
2812 */
skb_reserve(struct sk_buff * skb,int len)2813 static inline void skb_reserve(struct sk_buff *skb, int len)
2814 {
2815 skb->data += len;
2816 skb->tail += len;
2817 }
2818
2819 /**
2820 * skb_tailroom_reserve - adjust reserved_tailroom
2821 * @skb: buffer to alter
2822 * @mtu: maximum amount of headlen permitted
2823 * @needed_tailroom: minimum amount of reserved_tailroom
2824 *
2825 * Set reserved_tailroom so that headlen can be as large as possible but
2826 * not larger than mtu and tailroom cannot be smaller than
2827 * needed_tailroom.
2828 * The required headroom should already have been reserved before using
2829 * this function.
2830 */
skb_tailroom_reserve(struct sk_buff * skb,unsigned int mtu,unsigned int needed_tailroom)2831 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2832 unsigned int needed_tailroom)
2833 {
2834 SKB_LINEAR_ASSERT(skb);
2835 if (mtu < skb_tailroom(skb) - needed_tailroom)
2836 /* use at most mtu */
2837 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2838 else
2839 /* use up to all available space */
2840 skb->reserved_tailroom = needed_tailroom;
2841 }
2842
2843 #define ENCAP_TYPE_ETHER 0
2844 #define ENCAP_TYPE_IPPROTO 1
2845
skb_set_inner_protocol(struct sk_buff * skb,__be16 protocol)2846 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2847 __be16 protocol)
2848 {
2849 skb->inner_protocol = protocol;
2850 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2851 }
2852
skb_set_inner_ipproto(struct sk_buff * skb,__u8 ipproto)2853 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2854 __u8 ipproto)
2855 {
2856 skb->inner_ipproto = ipproto;
2857 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2858 }
2859
skb_reset_inner_headers(struct sk_buff * skb)2860 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2861 {
2862 skb->inner_mac_header = skb->mac_header;
2863 skb->inner_network_header = skb->network_header;
2864 skb->inner_transport_header = skb->transport_header;
2865 }
2866
skb_reset_mac_len(struct sk_buff * skb)2867 static inline void skb_reset_mac_len(struct sk_buff *skb)
2868 {
2869 skb->mac_len = skb->network_header - skb->mac_header;
2870 }
2871
skb_inner_transport_header(const struct sk_buff * skb)2872 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2873 *skb)
2874 {
2875 return skb->head + skb->inner_transport_header;
2876 }
2877
skb_inner_transport_offset(const struct sk_buff * skb)2878 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2879 {
2880 return skb_inner_transport_header(skb) - skb->data;
2881 }
2882
skb_reset_inner_transport_header(struct sk_buff * skb)2883 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2884 {
2885 skb->inner_transport_header = skb->data - skb->head;
2886 }
2887
skb_set_inner_transport_header(struct sk_buff * skb,const int offset)2888 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2889 const int offset)
2890 {
2891 skb_reset_inner_transport_header(skb);
2892 skb->inner_transport_header += offset;
2893 }
2894
skb_inner_network_header(const struct sk_buff * skb)2895 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2896 {
2897 return skb->head + skb->inner_network_header;
2898 }
2899
skb_reset_inner_network_header(struct sk_buff * skb)2900 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2901 {
2902 skb->inner_network_header = skb->data - skb->head;
2903 }
2904
skb_set_inner_network_header(struct sk_buff * skb,const int offset)2905 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2906 const int offset)
2907 {
2908 skb_reset_inner_network_header(skb);
2909 skb->inner_network_header += offset;
2910 }
2911
skb_inner_network_header_was_set(const struct sk_buff * skb)2912 static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb)
2913 {
2914 return skb->inner_network_header > 0;
2915 }
2916
skb_inner_mac_header(const struct sk_buff * skb)2917 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2918 {
2919 return skb->head + skb->inner_mac_header;
2920 }
2921
skb_reset_inner_mac_header(struct sk_buff * skb)2922 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2923 {
2924 skb->inner_mac_header = skb->data - skb->head;
2925 }
2926
skb_set_inner_mac_header(struct sk_buff * skb,const int offset)2927 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2928 const int offset)
2929 {
2930 skb_reset_inner_mac_header(skb);
2931 skb->inner_mac_header += offset;
2932 }
skb_transport_header_was_set(const struct sk_buff * skb)2933 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2934 {
2935 return skb->transport_header != (typeof(skb->transport_header))~0U;
2936 }
2937
skb_transport_header(const struct sk_buff * skb)2938 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2939 {
2940 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
2941 return skb->head + skb->transport_header;
2942 }
2943
skb_reset_transport_header(struct sk_buff * skb)2944 static inline void skb_reset_transport_header(struct sk_buff *skb)
2945 {
2946 skb->transport_header = skb->data - skb->head;
2947 }
2948
skb_set_transport_header(struct sk_buff * skb,const int offset)2949 static inline void skb_set_transport_header(struct sk_buff *skb,
2950 const int offset)
2951 {
2952 skb_reset_transport_header(skb);
2953 skb->transport_header += offset;
2954 }
2955
skb_network_header(const struct sk_buff * skb)2956 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2957 {
2958 return skb->head + skb->network_header;
2959 }
2960
skb_reset_network_header(struct sk_buff * skb)2961 static inline void skb_reset_network_header(struct sk_buff *skb)
2962 {
2963 skb->network_header = skb->data - skb->head;
2964 }
2965
skb_set_network_header(struct sk_buff * skb,const int offset)2966 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2967 {
2968 skb_reset_network_header(skb);
2969 skb->network_header += offset;
2970 }
2971
skb_mac_header_was_set(const struct sk_buff * skb)2972 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2973 {
2974 return skb->mac_header != (typeof(skb->mac_header))~0U;
2975 }
2976
skb_mac_header(const struct sk_buff * skb)2977 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2978 {
2979 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2980 return skb->head + skb->mac_header;
2981 }
2982
skb_mac_offset(const struct sk_buff * skb)2983 static inline int skb_mac_offset(const struct sk_buff *skb)
2984 {
2985 return skb_mac_header(skb) - skb->data;
2986 }
2987
skb_mac_header_len(const struct sk_buff * skb)2988 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2989 {
2990 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2991 return skb->network_header - skb->mac_header;
2992 }
2993
skb_unset_mac_header(struct sk_buff * skb)2994 static inline void skb_unset_mac_header(struct sk_buff *skb)
2995 {
2996 skb->mac_header = (typeof(skb->mac_header))~0U;
2997 }
2998
skb_reset_mac_header(struct sk_buff * skb)2999 static inline void skb_reset_mac_header(struct sk_buff *skb)
3000 {
3001 skb->mac_header = skb->data - skb->head;
3002 }
3003
skb_set_mac_header(struct sk_buff * skb,const int offset)3004 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
3005 {
3006 skb_reset_mac_header(skb);
3007 skb->mac_header += offset;
3008 }
3009
skb_pop_mac_header(struct sk_buff * skb)3010 static inline void skb_pop_mac_header(struct sk_buff *skb)
3011 {
3012 skb->mac_header = skb->network_header;
3013 }
3014
skb_probe_transport_header(struct sk_buff * skb)3015 static inline void skb_probe_transport_header(struct sk_buff *skb)
3016 {
3017 struct flow_keys_basic keys;
3018
3019 if (skb_transport_header_was_set(skb))
3020 return;
3021
3022 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
3023 NULL, 0, 0, 0, 0))
3024 skb_set_transport_header(skb, keys.control.thoff);
3025 }
3026
skb_mac_header_rebuild(struct sk_buff * skb)3027 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
3028 {
3029 if (skb_mac_header_was_set(skb)) {
3030 const unsigned char *old_mac = skb_mac_header(skb);
3031
3032 skb_set_mac_header(skb, -skb->mac_len);
3033 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
3034 }
3035 }
3036
3037 /* Move the full mac header up to current network_header.
3038 * Leaves skb->data pointing at offset skb->mac_len into the mac_header.
3039 * Must be provided the complete mac header length.
3040 */
skb_mac_header_rebuild_full(struct sk_buff * skb,u32 full_mac_len)3041 static inline void skb_mac_header_rebuild_full(struct sk_buff *skb, u32 full_mac_len)
3042 {
3043 if (skb_mac_header_was_set(skb)) {
3044 const unsigned char *old_mac = skb_mac_header(skb);
3045
3046 skb_set_mac_header(skb, -full_mac_len);
3047 memmove(skb_mac_header(skb), old_mac, full_mac_len);
3048 __skb_push(skb, full_mac_len - skb->mac_len);
3049 }
3050 }
3051
skb_checksum_start_offset(const struct sk_buff * skb)3052 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
3053 {
3054 return skb->csum_start - skb_headroom(skb);
3055 }
3056
skb_checksum_start(const struct sk_buff * skb)3057 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
3058 {
3059 return skb->head + skb->csum_start;
3060 }
3061
skb_transport_offset(const struct sk_buff * skb)3062 static inline int skb_transport_offset(const struct sk_buff *skb)
3063 {
3064 return skb_transport_header(skb) - skb->data;
3065 }
3066
skb_network_header_len(const struct sk_buff * skb)3067 static inline u32 skb_network_header_len(const struct sk_buff *skb)
3068 {
3069 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
3070 return skb->transport_header - skb->network_header;
3071 }
3072
skb_inner_network_header_len(const struct sk_buff * skb)3073 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
3074 {
3075 return skb->inner_transport_header - skb->inner_network_header;
3076 }
3077
skb_network_offset(const struct sk_buff * skb)3078 static inline int skb_network_offset(const struct sk_buff *skb)
3079 {
3080 return skb_network_header(skb) - skb->data;
3081 }
3082
skb_inner_network_offset(const struct sk_buff * skb)3083 static inline int skb_inner_network_offset(const struct sk_buff *skb)
3084 {
3085 return skb_inner_network_header(skb) - skb->data;
3086 }
3087
pskb_network_may_pull(struct sk_buff * skb,unsigned int len)3088 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
3089 {
3090 return pskb_may_pull(skb, skb_network_offset(skb) + len);
3091 }
3092
3093 /*
3094 * CPUs often take a performance hit when accessing unaligned memory
3095 * locations. The actual performance hit varies, it can be small if the
3096 * hardware handles it or large if we have to take an exception and fix it
3097 * in software.
3098 *
3099 * Since an ethernet header is 14 bytes network drivers often end up with
3100 * the IP header at an unaligned offset. The IP header can be aligned by
3101 * shifting the start of the packet by 2 bytes. Drivers should do this
3102 * with:
3103 *
3104 * skb_reserve(skb, NET_IP_ALIGN);
3105 *
3106 * The downside to this alignment of the IP header is that the DMA is now
3107 * unaligned. On some architectures the cost of an unaligned DMA is high
3108 * and this cost outweighs the gains made by aligning the IP header.
3109 *
3110 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
3111 * to be overridden.
3112 */
3113 #ifndef NET_IP_ALIGN
3114 #define NET_IP_ALIGN 2
3115 #endif
3116
3117 /*
3118 * The networking layer reserves some headroom in skb data (via
3119 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
3120 * the header has to grow. In the default case, if the header has to grow
3121 * 32 bytes or less we avoid the reallocation.
3122 *
3123 * Unfortunately this headroom changes the DMA alignment of the resulting
3124 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
3125 * on some architectures. An architecture can override this value,
3126 * perhaps setting it to a cacheline in size (since that will maintain
3127 * cacheline alignment of the DMA). It must be a power of 2.
3128 *
3129 * Various parts of the networking layer expect at least 32 bytes of
3130 * headroom, you should not reduce this.
3131 *
3132 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
3133 * to reduce average number of cache lines per packet.
3134 * get_rps_cpu() for example only access one 64 bytes aligned block :
3135 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
3136 */
3137 #ifndef NET_SKB_PAD
3138 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
3139 #endif
3140
3141 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
3142
__skb_set_length(struct sk_buff * skb,unsigned int len)3143 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
3144 {
3145 if (WARN_ON(skb_is_nonlinear(skb)))
3146 return;
3147 skb->len = len;
3148 skb_set_tail_pointer(skb, len);
3149 }
3150
__skb_trim(struct sk_buff * skb,unsigned int len)3151 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
3152 {
3153 __skb_set_length(skb, len);
3154 }
3155
3156 void skb_trim(struct sk_buff *skb, unsigned int len);
3157
__pskb_trim(struct sk_buff * skb,unsigned int len)3158 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
3159 {
3160 if (skb->data_len)
3161 return ___pskb_trim(skb, len);
3162 __skb_trim(skb, len);
3163 return 0;
3164 }
3165
pskb_trim(struct sk_buff * skb,unsigned int len)3166 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
3167 {
3168 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
3169 }
3170
3171 /**
3172 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
3173 * @skb: buffer to alter
3174 * @len: new length
3175 *
3176 * This is identical to pskb_trim except that the caller knows that
3177 * the skb is not cloned so we should never get an error due to out-
3178 * of-memory.
3179 */
pskb_trim_unique(struct sk_buff * skb,unsigned int len)3180 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
3181 {
3182 int err = pskb_trim(skb, len);
3183 BUG_ON(err);
3184 }
3185
__skb_grow(struct sk_buff * skb,unsigned int len)3186 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
3187 {
3188 unsigned int diff = len - skb->len;
3189
3190 if (skb_tailroom(skb) < diff) {
3191 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
3192 GFP_ATOMIC);
3193 if (ret)
3194 return ret;
3195 }
3196 __skb_set_length(skb, len);
3197 return 0;
3198 }
3199
3200 /**
3201 * skb_orphan - orphan a buffer
3202 * @skb: buffer to orphan
3203 *
3204 * If a buffer currently has an owner then we call the owner's
3205 * destructor function and make the @skb unowned. The buffer continues
3206 * to exist but is no longer charged to its former owner.
3207 */
skb_orphan(struct sk_buff * skb)3208 static inline void skb_orphan(struct sk_buff *skb)
3209 {
3210 if (skb->destructor) {
3211 skb->destructor(skb);
3212 skb->destructor = NULL;
3213 skb->sk = NULL;
3214 } else {
3215 BUG_ON(skb->sk);
3216 }
3217 }
3218
3219 /**
3220 * skb_orphan_frags - orphan the frags contained in a buffer
3221 * @skb: buffer to orphan frags from
3222 * @gfp_mask: allocation mask for replacement pages
3223 *
3224 * For each frag in the SKB which needs a destructor (i.e. has an
3225 * owner) create a copy of that frag and release the original
3226 * page by calling the destructor.
3227 */
skb_orphan_frags(struct sk_buff * skb,gfp_t gfp_mask)3228 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3229 {
3230 if (likely(!skb_zcopy(skb)))
3231 return 0;
3232 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3233 return 0;
3234 return skb_copy_ubufs(skb, gfp_mask);
3235 }
3236
3237 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
skb_orphan_frags_rx(struct sk_buff * skb,gfp_t gfp_mask)3238 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3239 {
3240 if (likely(!skb_zcopy(skb)))
3241 return 0;
3242 return skb_copy_ubufs(skb, gfp_mask);
3243 }
3244
3245 /**
3246 * __skb_queue_purge_reason - empty a list
3247 * @list: list to empty
3248 * @reason: drop reason
3249 *
3250 * Delete all buffers on an &sk_buff list. Each buffer is removed from
3251 * the list and one reference dropped. This function does not take the
3252 * list lock and the caller must hold the relevant locks to use it.
3253 */
__skb_queue_purge_reason(struct sk_buff_head * list,enum skb_drop_reason reason)3254 static inline void __skb_queue_purge_reason(struct sk_buff_head *list,
3255 enum skb_drop_reason reason)
3256 {
3257 struct sk_buff *skb;
3258
3259 while ((skb = __skb_dequeue(list)) != NULL)
3260 kfree_skb_reason(skb, reason);
3261 }
3262
__skb_queue_purge(struct sk_buff_head * list)3263 static inline void __skb_queue_purge(struct sk_buff_head *list)
3264 {
3265 __skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3266 }
3267
3268 void skb_queue_purge_reason(struct sk_buff_head *list,
3269 enum skb_drop_reason reason);
3270
skb_queue_purge(struct sk_buff_head * list)3271 static inline void skb_queue_purge(struct sk_buff_head *list)
3272 {
3273 skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE);
3274 }
3275
3276 unsigned int skb_rbtree_purge(struct rb_root *root);
3277 void skb_errqueue_purge(struct sk_buff_head *list);
3278
3279 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3280
3281 /**
3282 * netdev_alloc_frag - allocate a page fragment
3283 * @fragsz: fragment size
3284 *
3285 * Allocates a frag from a page for receive buffer.
3286 * Uses GFP_ATOMIC allocations.
3287 */
netdev_alloc_frag(unsigned int fragsz)3288 static inline void *netdev_alloc_frag(unsigned int fragsz)
3289 {
3290 return __netdev_alloc_frag_align(fragsz, ~0u);
3291 }
3292
netdev_alloc_frag_align(unsigned int fragsz,unsigned int align)3293 static inline void *netdev_alloc_frag_align(unsigned int fragsz,
3294 unsigned int align)
3295 {
3296 WARN_ON_ONCE(!is_power_of_2(align));
3297 return __netdev_alloc_frag_align(fragsz, -align);
3298 }
3299
3300 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
3301 gfp_t gfp_mask);
3302
3303 /**
3304 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
3305 * @dev: network device to receive on
3306 * @length: length to allocate
3307 *
3308 * Allocate a new &sk_buff and assign it a usage count of one. The
3309 * buffer has unspecified headroom built in. Users should allocate
3310 * the headroom they think they need without accounting for the
3311 * built in space. The built in space is used for optimisations.
3312 *
3313 * %NULL is returned if there is no free memory. Although this function
3314 * allocates memory it can be called from an interrupt.
3315 */
netdev_alloc_skb(struct net_device * dev,unsigned int length)3316 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
3317 unsigned int length)
3318 {
3319 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3320 }
3321
3322 /* legacy helper around __netdev_alloc_skb() */
__dev_alloc_skb(unsigned int length,gfp_t gfp_mask)3323 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
3324 gfp_t gfp_mask)
3325 {
3326 return __netdev_alloc_skb(NULL, length, gfp_mask);
3327 }
3328
3329 /* legacy helper around netdev_alloc_skb() */
dev_alloc_skb(unsigned int length)3330 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
3331 {
3332 return netdev_alloc_skb(NULL, length);
3333 }
3334
3335
__netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length,gfp_t gfp)3336 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
3337 unsigned int length, gfp_t gfp)
3338 {
3339 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
3340
3341 if (NET_IP_ALIGN && skb)
3342 skb_reserve(skb, NET_IP_ALIGN);
3343 return skb;
3344 }
3345
netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length)3346 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
3347 unsigned int length)
3348 {
3349 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3350 }
3351
skb_free_frag(void * addr)3352 static inline void skb_free_frag(void *addr)
3353 {
3354 page_frag_free(addr);
3355 }
3356
3357 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3358
napi_alloc_frag(unsigned int fragsz)3359 static inline void *napi_alloc_frag(unsigned int fragsz)
3360 {
3361 return __napi_alloc_frag_align(fragsz, ~0u);
3362 }
3363
napi_alloc_frag_align(unsigned int fragsz,unsigned int align)3364 static inline void *napi_alloc_frag_align(unsigned int fragsz,
3365 unsigned int align)
3366 {
3367 WARN_ON_ONCE(!is_power_of_2(align));
3368 return __napi_alloc_frag_align(fragsz, -align);
3369 }
3370
3371 struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int length);
3372 void napi_consume_skb(struct sk_buff *skb, int budget);
3373
3374 void napi_skb_free_stolen_head(struct sk_buff *skb);
3375 void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason);
3376
3377 /**
3378 * __dev_alloc_pages - allocate page for network Rx
3379 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3380 * @order: size of the allocation
3381 *
3382 * Allocate a new page.
3383 *
3384 * %NULL is returned if there is no free memory.
3385 */
__dev_alloc_pages_noprof(gfp_t gfp_mask,unsigned int order)3386 static inline struct page *__dev_alloc_pages_noprof(gfp_t gfp_mask,
3387 unsigned int order)
3388 {
3389 /* This piece of code contains several assumptions.
3390 * 1. This is for device Rx, therefore a cold page is preferred.
3391 * 2. The expectation is the user wants a compound page.
3392 * 3. If requesting a order 0 page it will not be compound
3393 * due to the check to see if order has a value in prep_new_page
3394 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3395 * code in gfp_to_alloc_flags that should be enforcing this.
3396 */
3397 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
3398
3399 return alloc_pages_node_noprof(NUMA_NO_NODE, gfp_mask, order);
3400 }
3401 #define __dev_alloc_pages(...) alloc_hooks(__dev_alloc_pages_noprof(__VA_ARGS__))
3402
3403 #define dev_alloc_pages(_order) __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, _order)
3404
3405 /**
3406 * __dev_alloc_page - allocate a page for network Rx
3407 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3408 *
3409 * Allocate a new page.
3410 *
3411 * %NULL is returned if there is no free memory.
3412 */
__dev_alloc_page_noprof(gfp_t gfp_mask)3413 static inline struct page *__dev_alloc_page_noprof(gfp_t gfp_mask)
3414 {
3415 return __dev_alloc_pages_noprof(gfp_mask, 0);
3416 }
3417 #define __dev_alloc_page(...) alloc_hooks(__dev_alloc_page_noprof(__VA_ARGS__))
3418
3419 #define dev_alloc_page() dev_alloc_pages(0)
3420
3421 /**
3422 * dev_page_is_reusable - check whether a page can be reused for network Rx
3423 * @page: the page to test
3424 *
3425 * A page shouldn't be considered for reusing/recycling if it was allocated
3426 * under memory pressure or at a distant memory node.
3427 *
3428 * Returns false if this page should be returned to page allocator, true
3429 * otherwise.
3430 */
dev_page_is_reusable(const struct page * page)3431 static inline bool dev_page_is_reusable(const struct page *page)
3432 {
3433 return likely(page_to_nid(page) == numa_mem_id() &&
3434 !page_is_pfmemalloc(page));
3435 }
3436
3437 /**
3438 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3439 * @page: The page that was allocated from skb_alloc_page
3440 * @skb: The skb that may need pfmemalloc set
3441 */
skb_propagate_pfmemalloc(const struct page * page,struct sk_buff * skb)3442 static inline void skb_propagate_pfmemalloc(const struct page *page,
3443 struct sk_buff *skb)
3444 {
3445 if (page_is_pfmemalloc(page))
3446 skb->pfmemalloc = true;
3447 }
3448
3449 /**
3450 * skb_frag_off() - Returns the offset of a skb fragment
3451 * @frag: the paged fragment
3452 */
skb_frag_off(const skb_frag_t * frag)3453 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3454 {
3455 return frag->offset;
3456 }
3457
3458 /**
3459 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3460 * @frag: skb fragment
3461 * @delta: value to add
3462 */
skb_frag_off_add(skb_frag_t * frag,int delta)3463 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3464 {
3465 frag->offset += delta;
3466 }
3467
3468 /**
3469 * skb_frag_off_set() - Sets the offset of a skb fragment
3470 * @frag: skb fragment
3471 * @offset: offset of fragment
3472 */
skb_frag_off_set(skb_frag_t * frag,unsigned int offset)3473 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3474 {
3475 frag->offset = offset;
3476 }
3477
3478 /**
3479 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3480 * @fragto: skb fragment where offset is set
3481 * @fragfrom: skb fragment offset is copied from
3482 */
skb_frag_off_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3483 static inline void skb_frag_off_copy(skb_frag_t *fragto,
3484 const skb_frag_t *fragfrom)
3485 {
3486 fragto->offset = fragfrom->offset;
3487 }
3488
3489 /**
3490 * skb_frag_page - retrieve the page referred to by a paged fragment
3491 * @frag: the paged fragment
3492 *
3493 * Returns the &struct page associated with @frag.
3494 */
skb_frag_page(const skb_frag_t * frag)3495 static inline struct page *skb_frag_page(const skb_frag_t *frag)
3496 {
3497 return netmem_to_page(frag->netmem);
3498 }
3499
3500 int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
3501 unsigned int headroom);
3502 int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
3503 struct bpf_prog *prog);
3504 /**
3505 * skb_frag_address - gets the address of the data contained in a paged fragment
3506 * @frag: the paged fragment buffer
3507 *
3508 * Returns the address of the data within @frag. The page must already
3509 * be mapped.
3510 */
skb_frag_address(const skb_frag_t * frag)3511 static inline void *skb_frag_address(const skb_frag_t *frag)
3512 {
3513 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3514 }
3515
3516 /**
3517 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3518 * @frag: the paged fragment buffer
3519 *
3520 * Returns the address of the data within @frag. Checks that the page
3521 * is mapped and returns %NULL otherwise.
3522 */
skb_frag_address_safe(const skb_frag_t * frag)3523 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3524 {
3525 void *ptr = page_address(skb_frag_page(frag));
3526 if (unlikely(!ptr))
3527 return NULL;
3528
3529 return ptr + skb_frag_off(frag);
3530 }
3531
3532 /**
3533 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3534 * @fragto: skb fragment where page is set
3535 * @fragfrom: skb fragment page is copied from
3536 */
skb_frag_page_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3537 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3538 const skb_frag_t *fragfrom)
3539 {
3540 fragto->netmem = fragfrom->netmem;
3541 }
3542
3543 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3544
3545 /**
3546 * skb_frag_dma_map - maps a paged fragment via the DMA API
3547 * @dev: the device to map the fragment to
3548 * @frag: the paged fragment to map
3549 * @offset: the offset within the fragment (starting at the
3550 * fragment's own offset)
3551 * @size: the number of bytes to map
3552 * @dir: the direction of the mapping (``PCI_DMA_*``)
3553 *
3554 * Maps the page associated with @frag to @device.
3555 */
skb_frag_dma_map(struct device * dev,const skb_frag_t * frag,size_t offset,size_t size,enum dma_data_direction dir)3556 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3557 const skb_frag_t *frag,
3558 size_t offset, size_t size,
3559 enum dma_data_direction dir)
3560 {
3561 return dma_map_page(dev, skb_frag_page(frag),
3562 skb_frag_off(frag) + offset, size, dir);
3563 }
3564
pskb_copy(struct sk_buff * skb,gfp_t gfp_mask)3565 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3566 gfp_t gfp_mask)
3567 {
3568 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3569 }
3570
3571
pskb_copy_for_clone(struct sk_buff * skb,gfp_t gfp_mask)3572 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3573 gfp_t gfp_mask)
3574 {
3575 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3576 }
3577
3578
3579 /**
3580 * skb_clone_writable - is the header of a clone writable
3581 * @skb: buffer to check
3582 * @len: length up to which to write
3583 *
3584 * Returns true if modifying the header part of the cloned buffer
3585 * does not requires the data to be copied.
3586 */
skb_clone_writable(const struct sk_buff * skb,unsigned int len)3587 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3588 {
3589 return !skb_header_cloned(skb) &&
3590 skb_headroom(skb) + len <= skb->hdr_len;
3591 }
3592
skb_try_make_writable(struct sk_buff * skb,unsigned int write_len)3593 static inline int skb_try_make_writable(struct sk_buff *skb,
3594 unsigned int write_len)
3595 {
3596 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3597 pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3598 }
3599
__skb_cow(struct sk_buff * skb,unsigned int headroom,int cloned)3600 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3601 int cloned)
3602 {
3603 int delta = 0;
3604
3605 if (headroom > skb_headroom(skb))
3606 delta = headroom - skb_headroom(skb);
3607
3608 if (delta || cloned)
3609 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3610 GFP_ATOMIC);
3611 return 0;
3612 }
3613
3614 /**
3615 * skb_cow - copy header of skb when it is required
3616 * @skb: buffer to cow
3617 * @headroom: needed headroom
3618 *
3619 * If the skb passed lacks sufficient headroom or its data part
3620 * is shared, data is reallocated. If reallocation fails, an error
3621 * is returned and original skb is not changed.
3622 *
3623 * The result is skb with writable area skb->head...skb->tail
3624 * and at least @headroom of space at head.
3625 */
skb_cow(struct sk_buff * skb,unsigned int headroom)3626 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3627 {
3628 return __skb_cow(skb, headroom, skb_cloned(skb));
3629 }
3630
3631 /**
3632 * skb_cow_head - skb_cow but only making the head writable
3633 * @skb: buffer to cow
3634 * @headroom: needed headroom
3635 *
3636 * This function is identical to skb_cow except that we replace the
3637 * skb_cloned check by skb_header_cloned. It should be used when
3638 * you only need to push on some header and do not need to modify
3639 * the data.
3640 */
skb_cow_head(struct sk_buff * skb,unsigned int headroom)3641 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3642 {
3643 return __skb_cow(skb, headroom, skb_header_cloned(skb));
3644 }
3645
3646 /**
3647 * skb_padto - pad an skbuff up to a minimal size
3648 * @skb: buffer to pad
3649 * @len: minimal length
3650 *
3651 * Pads up a buffer to ensure the trailing bytes exist and are
3652 * blanked. If the buffer already contains sufficient data it
3653 * is untouched. Otherwise it is extended. Returns zero on
3654 * success. The skb is freed on error.
3655 */
skb_padto(struct sk_buff * skb,unsigned int len)3656 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3657 {
3658 unsigned int size = skb->len;
3659 if (likely(size >= len))
3660 return 0;
3661 return skb_pad(skb, len - size);
3662 }
3663
3664 /**
3665 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3666 * @skb: buffer to pad
3667 * @len: minimal length
3668 * @free_on_error: free buffer on error
3669 *
3670 * Pads up a buffer to ensure the trailing bytes exist and are
3671 * blanked. If the buffer already contains sufficient data it
3672 * is untouched. Otherwise it is extended. Returns zero on
3673 * success. The skb is freed on error if @free_on_error is true.
3674 */
__skb_put_padto(struct sk_buff * skb,unsigned int len,bool free_on_error)3675 static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3676 unsigned int len,
3677 bool free_on_error)
3678 {
3679 unsigned int size = skb->len;
3680
3681 if (unlikely(size < len)) {
3682 len -= size;
3683 if (__skb_pad(skb, len, free_on_error))
3684 return -ENOMEM;
3685 __skb_put(skb, len);
3686 }
3687 return 0;
3688 }
3689
3690 /**
3691 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3692 * @skb: buffer to pad
3693 * @len: minimal length
3694 *
3695 * Pads up a buffer to ensure the trailing bytes exist and are
3696 * blanked. If the buffer already contains sufficient data it
3697 * is untouched. Otherwise it is extended. Returns zero on
3698 * success. The skb is freed on error.
3699 */
skb_put_padto(struct sk_buff * skb,unsigned int len)3700 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3701 {
3702 return __skb_put_padto(skb, len, true);
3703 }
3704
3705 bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i)
3706 __must_check;
3707
skb_add_data(struct sk_buff * skb,struct iov_iter * from,int copy)3708 static inline int skb_add_data(struct sk_buff *skb,
3709 struct iov_iter *from, int copy)
3710 {
3711 const int off = skb->len;
3712
3713 if (skb->ip_summed == CHECKSUM_NONE) {
3714 __wsum csum = 0;
3715 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3716 &csum, from)) {
3717 skb->csum = csum_block_add(skb->csum, csum, off);
3718 return 0;
3719 }
3720 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3721 return 0;
3722
3723 __skb_trim(skb, off);
3724 return -EFAULT;
3725 }
3726
skb_can_coalesce(struct sk_buff * skb,int i,const struct page * page,int off)3727 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3728 const struct page *page, int off)
3729 {
3730 if (skb_zcopy(skb))
3731 return false;
3732 if (i) {
3733 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3734
3735 return page == skb_frag_page(frag) &&
3736 off == skb_frag_off(frag) + skb_frag_size(frag);
3737 }
3738 return false;
3739 }
3740
__skb_linearize(struct sk_buff * skb)3741 static inline int __skb_linearize(struct sk_buff *skb)
3742 {
3743 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3744 }
3745
3746 /**
3747 * skb_linearize - convert paged skb to linear one
3748 * @skb: buffer to linarize
3749 *
3750 * If there is no free memory -ENOMEM is returned, otherwise zero
3751 * is returned and the old skb data released.
3752 */
skb_linearize(struct sk_buff * skb)3753 static inline int skb_linearize(struct sk_buff *skb)
3754 {
3755 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3756 }
3757
3758 /**
3759 * skb_has_shared_frag - can any frag be overwritten
3760 * @skb: buffer to test
3761 *
3762 * Return true if the skb has at least one frag that might be modified
3763 * by an external entity (as in vmsplice()/sendfile())
3764 */
skb_has_shared_frag(const struct sk_buff * skb)3765 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3766 {
3767 return skb_is_nonlinear(skb) &&
3768 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3769 }
3770
3771 /**
3772 * skb_linearize_cow - make sure skb is linear and writable
3773 * @skb: buffer to process
3774 *
3775 * If there is no free memory -ENOMEM is returned, otherwise zero
3776 * is returned and the old skb data released.
3777 */
skb_linearize_cow(struct sk_buff * skb)3778 static inline int skb_linearize_cow(struct sk_buff *skb)
3779 {
3780 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3781 __skb_linearize(skb) : 0;
3782 }
3783
3784 static __always_inline void
__skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3785 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3786 unsigned int off)
3787 {
3788 if (skb->ip_summed == CHECKSUM_COMPLETE)
3789 skb->csum = csum_block_sub(skb->csum,
3790 csum_partial(start, len, 0), off);
3791 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3792 skb_checksum_start_offset(skb) < 0)
3793 skb->ip_summed = CHECKSUM_NONE;
3794 }
3795
3796 /**
3797 * skb_postpull_rcsum - update checksum for received skb after pull
3798 * @skb: buffer to update
3799 * @start: start of data before pull
3800 * @len: length of data pulled
3801 *
3802 * After doing a pull on a received packet, you need to call this to
3803 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3804 * CHECKSUM_NONE so that it can be recomputed from scratch.
3805 */
skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3806 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3807 const void *start, unsigned int len)
3808 {
3809 if (skb->ip_summed == CHECKSUM_COMPLETE)
3810 skb->csum = wsum_negate(csum_partial(start, len,
3811 wsum_negate(skb->csum)));
3812 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3813 skb_checksum_start_offset(skb) < 0)
3814 skb->ip_summed = CHECKSUM_NONE;
3815 }
3816
3817 static __always_inline void
__skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3818 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3819 unsigned int off)
3820 {
3821 if (skb->ip_summed == CHECKSUM_COMPLETE)
3822 skb->csum = csum_block_add(skb->csum,
3823 csum_partial(start, len, 0), off);
3824 }
3825
3826 /**
3827 * skb_postpush_rcsum - update checksum for received skb after push
3828 * @skb: buffer to update
3829 * @start: start of data after push
3830 * @len: length of data pushed
3831 *
3832 * After doing a push on a received packet, you need to call this to
3833 * update the CHECKSUM_COMPLETE checksum.
3834 */
skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3835 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3836 const void *start, unsigned int len)
3837 {
3838 __skb_postpush_rcsum(skb, start, len, 0);
3839 }
3840
3841 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3842
3843 /**
3844 * skb_push_rcsum - push skb and update receive checksum
3845 * @skb: buffer to update
3846 * @len: length of data pulled
3847 *
3848 * This function performs an skb_push on the packet and updates
3849 * the CHECKSUM_COMPLETE checksum. It should be used on
3850 * receive path processing instead of skb_push unless you know
3851 * that the checksum difference is zero (e.g., a valid IP header)
3852 * or you are setting ip_summed to CHECKSUM_NONE.
3853 */
skb_push_rcsum(struct sk_buff * skb,unsigned int len)3854 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3855 {
3856 skb_push(skb, len);
3857 skb_postpush_rcsum(skb, skb->data, len);
3858 return skb->data;
3859 }
3860
3861 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3862 /**
3863 * pskb_trim_rcsum - trim received skb and update checksum
3864 * @skb: buffer to trim
3865 * @len: new length
3866 *
3867 * This is exactly the same as pskb_trim except that it ensures the
3868 * checksum of received packets are still valid after the operation.
3869 * It can change skb pointers.
3870 */
3871
pskb_trim_rcsum(struct sk_buff * skb,unsigned int len)3872 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3873 {
3874 if (likely(len >= skb->len))
3875 return 0;
3876 return pskb_trim_rcsum_slow(skb, len);
3877 }
3878
__skb_trim_rcsum(struct sk_buff * skb,unsigned int len)3879 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3880 {
3881 if (skb->ip_summed == CHECKSUM_COMPLETE)
3882 skb->ip_summed = CHECKSUM_NONE;
3883 __skb_trim(skb, len);
3884 return 0;
3885 }
3886
__skb_grow_rcsum(struct sk_buff * skb,unsigned int len)3887 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3888 {
3889 if (skb->ip_summed == CHECKSUM_COMPLETE)
3890 skb->ip_summed = CHECKSUM_NONE;
3891 return __skb_grow(skb, len);
3892 }
3893
3894 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3895 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3896 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3897 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3898 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3899
3900 #define skb_queue_walk(queue, skb) \
3901 for (skb = (queue)->next; \
3902 skb != (struct sk_buff *)(queue); \
3903 skb = skb->next)
3904
3905 #define skb_queue_walk_safe(queue, skb, tmp) \
3906 for (skb = (queue)->next, tmp = skb->next; \
3907 skb != (struct sk_buff *)(queue); \
3908 skb = tmp, tmp = skb->next)
3909
3910 #define skb_queue_walk_from(queue, skb) \
3911 for (; skb != (struct sk_buff *)(queue); \
3912 skb = skb->next)
3913
3914 #define skb_rbtree_walk(skb, root) \
3915 for (skb = skb_rb_first(root); skb != NULL; \
3916 skb = skb_rb_next(skb))
3917
3918 #define skb_rbtree_walk_from(skb) \
3919 for (; skb != NULL; \
3920 skb = skb_rb_next(skb))
3921
3922 #define skb_rbtree_walk_from_safe(skb, tmp) \
3923 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3924 skb = tmp)
3925
3926 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3927 for (tmp = skb->next; \
3928 skb != (struct sk_buff *)(queue); \
3929 skb = tmp, tmp = skb->next)
3930
3931 #define skb_queue_reverse_walk(queue, skb) \
3932 for (skb = (queue)->prev; \
3933 skb != (struct sk_buff *)(queue); \
3934 skb = skb->prev)
3935
3936 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3937 for (skb = (queue)->prev, tmp = skb->prev; \
3938 skb != (struct sk_buff *)(queue); \
3939 skb = tmp, tmp = skb->prev)
3940
3941 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3942 for (tmp = skb->prev; \
3943 skb != (struct sk_buff *)(queue); \
3944 skb = tmp, tmp = skb->prev)
3945
skb_has_frag_list(const struct sk_buff * skb)3946 static inline bool skb_has_frag_list(const struct sk_buff *skb)
3947 {
3948 return skb_shinfo(skb)->frag_list != NULL;
3949 }
3950
skb_frag_list_init(struct sk_buff * skb)3951 static inline void skb_frag_list_init(struct sk_buff *skb)
3952 {
3953 skb_shinfo(skb)->frag_list = NULL;
3954 }
3955
3956 #define skb_walk_frags(skb, iter) \
3957 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3958
3959
3960 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
3961 int *err, long *timeo_p,
3962 const struct sk_buff *skb);
3963 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
3964 struct sk_buff_head *queue,
3965 unsigned int flags,
3966 int *off, int *err,
3967 struct sk_buff **last);
3968 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
3969 struct sk_buff_head *queue,
3970 unsigned int flags, int *off, int *err,
3971 struct sk_buff **last);
3972 struct sk_buff *__skb_recv_datagram(struct sock *sk,
3973 struct sk_buff_head *sk_queue,
3974 unsigned int flags, int *off, int *err);
3975 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
3976 __poll_t datagram_poll(struct file *file, struct socket *sock,
3977 struct poll_table_struct *wait);
3978 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
3979 struct iov_iter *to, int size);
skb_copy_datagram_msg(const struct sk_buff * from,int offset,struct msghdr * msg,int size)3980 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
3981 struct msghdr *msg, int size)
3982 {
3983 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3984 }
3985 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
3986 struct msghdr *msg);
3987 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
3988 struct iov_iter *to, int len,
3989 struct ahash_request *hash);
3990 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
3991 struct iov_iter *from, int len);
3992 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
3993 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
3994 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
3995 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
3996 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
3997 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
3998 int len);
3999 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
4000 struct pipe_inode_info *pipe, unsigned int len,
4001 unsigned int flags);
4002 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
4003 int len);
4004 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
4005 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
4006 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
4007 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
4008 int len, int hlen);
4009 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
4010 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
4011 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
4012 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
4013 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
4014 unsigned int offset);
4015 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
4016 int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
4017 int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev);
4018 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
4019 int skb_vlan_pop(struct sk_buff *skb);
4020 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
4021 int skb_eth_pop(struct sk_buff *skb);
4022 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
4023 const unsigned char *src);
4024 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
4025 int mac_len, bool ethernet);
4026 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
4027 bool ethernet);
4028 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
4029 int skb_mpls_dec_ttl(struct sk_buff *skb);
4030 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
4031 gfp_t gfp);
4032
memcpy_from_msg(void * data,struct msghdr * msg,int len)4033 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
4034 {
4035 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
4036 }
4037
memcpy_to_msg(struct msghdr * msg,void * data,int len)4038 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
4039 {
4040 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
4041 }
4042
4043 struct skb_checksum_ops {
4044 __wsum (*update)(const void *mem, int len, __wsum wsum);
4045 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
4046 };
4047
4048 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
4049
4050 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
4051 __wsum csum, const struct skb_checksum_ops *ops);
4052 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
4053 __wsum csum);
4054
4055 static inline void * __must_check
__skb_header_pointer(const struct sk_buff * skb,int offset,int len,const void * data,int hlen,void * buffer)4056 __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
4057 const void *data, int hlen, void *buffer)
4058 {
4059 if (likely(hlen - offset >= len))
4060 return (void *)data + offset;
4061
4062 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
4063 return NULL;
4064
4065 return buffer;
4066 }
4067
4068 static inline void * __must_check
skb_header_pointer(const struct sk_buff * skb,int offset,int len,void * buffer)4069 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
4070 {
4071 return __skb_header_pointer(skb, offset, len, skb->data,
4072 skb_headlen(skb), buffer);
4073 }
4074
4075 static inline void * __must_check
skb_pointer_if_linear(const struct sk_buff * skb,int offset,int len)4076 skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len)
4077 {
4078 if (likely(skb_headlen(skb) - offset >= len))
4079 return skb->data + offset;
4080 return NULL;
4081 }
4082
4083 /**
4084 * skb_needs_linearize - check if we need to linearize a given skb
4085 * depending on the given device features.
4086 * @skb: socket buffer to check
4087 * @features: net device features
4088 *
4089 * Returns true if either:
4090 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
4091 * 2. skb is fragmented and the device does not support SG.
4092 */
skb_needs_linearize(struct sk_buff * skb,netdev_features_t features)4093 static inline bool skb_needs_linearize(struct sk_buff *skb,
4094 netdev_features_t features)
4095 {
4096 return skb_is_nonlinear(skb) &&
4097 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
4098 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
4099 }
4100
skb_copy_from_linear_data(const struct sk_buff * skb,void * to,const unsigned int len)4101 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
4102 void *to,
4103 const unsigned int len)
4104 {
4105 memcpy(to, skb->data, len);
4106 }
4107
skb_copy_from_linear_data_offset(const struct sk_buff * skb,const int offset,void * to,const unsigned int len)4108 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4109 const int offset, void *to,
4110 const unsigned int len)
4111 {
4112 memcpy(to, skb->data + offset, len);
4113 }
4114
skb_copy_to_linear_data(struct sk_buff * skb,const void * from,const unsigned int len)4115 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4116 const void *from,
4117 const unsigned int len)
4118 {
4119 memcpy(skb->data, from, len);
4120 }
4121
skb_copy_to_linear_data_offset(struct sk_buff * skb,const int offset,const void * from,const unsigned int len)4122 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4123 const int offset,
4124 const void *from,
4125 const unsigned int len)
4126 {
4127 memcpy(skb->data + offset, from, len);
4128 }
4129
4130 void skb_init(void);
4131
skb_get_ktime(const struct sk_buff * skb)4132 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4133 {
4134 return skb->tstamp;
4135 }
4136
4137 /**
4138 * skb_get_timestamp - get timestamp from a skb
4139 * @skb: skb to get stamp from
4140 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
4141 *
4142 * Timestamps are stored in the skb as offsets to a base timestamp.
4143 * This function converts the offset back to a struct timeval and stores
4144 * it in stamp.
4145 */
skb_get_timestamp(const struct sk_buff * skb,struct __kernel_old_timeval * stamp)4146 static inline void skb_get_timestamp(const struct sk_buff *skb,
4147 struct __kernel_old_timeval *stamp)
4148 {
4149 *stamp = ns_to_kernel_old_timeval(skb->tstamp);
4150 }
4151
skb_get_new_timestamp(const struct sk_buff * skb,struct __kernel_sock_timeval * stamp)4152 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4153 struct __kernel_sock_timeval *stamp)
4154 {
4155 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4156
4157 stamp->tv_sec = ts.tv_sec;
4158 stamp->tv_usec = ts.tv_nsec / 1000;
4159 }
4160
skb_get_timestampns(const struct sk_buff * skb,struct __kernel_old_timespec * stamp)4161 static inline void skb_get_timestampns(const struct sk_buff *skb,
4162 struct __kernel_old_timespec *stamp)
4163 {
4164 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4165
4166 stamp->tv_sec = ts.tv_sec;
4167 stamp->tv_nsec = ts.tv_nsec;
4168 }
4169
skb_get_new_timestampns(const struct sk_buff * skb,struct __kernel_timespec * stamp)4170 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4171 struct __kernel_timespec *stamp)
4172 {
4173 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4174
4175 stamp->tv_sec = ts.tv_sec;
4176 stamp->tv_nsec = ts.tv_nsec;
4177 }
4178
__net_timestamp(struct sk_buff * skb)4179 static inline void __net_timestamp(struct sk_buff *skb)
4180 {
4181 skb->tstamp = ktime_get_real();
4182 skb->mono_delivery_time = 0;
4183 }
4184
net_timedelta(ktime_t t)4185 static inline ktime_t net_timedelta(ktime_t t)
4186 {
4187 return ktime_sub(ktime_get_real(), t);
4188 }
4189
skb_set_delivery_time(struct sk_buff * skb,ktime_t kt,bool mono)4190 static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4191 bool mono)
4192 {
4193 skb->tstamp = kt;
4194 skb->mono_delivery_time = kt && mono;
4195 }
4196
4197 DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4198
4199 /* It is used in the ingress path to clear the delivery_time.
4200 * If needed, set the skb->tstamp to the (rcv) timestamp.
4201 */
skb_clear_delivery_time(struct sk_buff * skb)4202 static inline void skb_clear_delivery_time(struct sk_buff *skb)
4203 {
4204 if (skb->mono_delivery_time) {
4205 skb->mono_delivery_time = 0;
4206 if (static_branch_unlikely(&netstamp_needed_key))
4207 skb->tstamp = ktime_get_real();
4208 else
4209 skb->tstamp = 0;
4210 }
4211 }
4212
skb_clear_tstamp(struct sk_buff * skb)4213 static inline void skb_clear_tstamp(struct sk_buff *skb)
4214 {
4215 if (skb->mono_delivery_time)
4216 return;
4217
4218 skb->tstamp = 0;
4219 }
4220
skb_tstamp(const struct sk_buff * skb)4221 static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4222 {
4223 if (skb->mono_delivery_time)
4224 return 0;
4225
4226 return skb->tstamp;
4227 }
4228
skb_tstamp_cond(const struct sk_buff * skb,bool cond)4229 static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4230 {
4231 if (!skb->mono_delivery_time && skb->tstamp)
4232 return skb->tstamp;
4233
4234 if (static_branch_unlikely(&netstamp_needed_key) || cond)
4235 return ktime_get_real();
4236
4237 return 0;
4238 }
4239
skb_metadata_len(const struct sk_buff * skb)4240 static inline u8 skb_metadata_len(const struct sk_buff *skb)
4241 {
4242 return skb_shinfo(skb)->meta_len;
4243 }
4244
skb_metadata_end(const struct sk_buff * skb)4245 static inline void *skb_metadata_end(const struct sk_buff *skb)
4246 {
4247 return skb_mac_header(skb);
4248 }
4249
__skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b,u8 meta_len)4250 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4251 const struct sk_buff *skb_b,
4252 u8 meta_len)
4253 {
4254 const void *a = skb_metadata_end(skb_a);
4255 const void *b = skb_metadata_end(skb_b);
4256 u64 diffs = 0;
4257
4258 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
4259 BITS_PER_LONG != 64)
4260 goto slow;
4261
4262 /* Using more efficient variant than plain call to memcmp(). */
4263 switch (meta_len) {
4264 #define __it(x, op) (x -= sizeof(u##op))
4265 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
4266 case 32: diffs |= __it_diff(a, b, 64);
4267 fallthrough;
4268 case 24: diffs |= __it_diff(a, b, 64);
4269 fallthrough;
4270 case 16: diffs |= __it_diff(a, b, 64);
4271 fallthrough;
4272 case 8: diffs |= __it_diff(a, b, 64);
4273 break;
4274 case 28: diffs |= __it_diff(a, b, 64);
4275 fallthrough;
4276 case 20: diffs |= __it_diff(a, b, 64);
4277 fallthrough;
4278 case 12: diffs |= __it_diff(a, b, 64);
4279 fallthrough;
4280 case 4: diffs |= __it_diff(a, b, 32);
4281 break;
4282 default:
4283 slow:
4284 return memcmp(a - meta_len, b - meta_len, meta_len);
4285 }
4286 return diffs;
4287 }
4288
skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b)4289 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4290 const struct sk_buff *skb_b)
4291 {
4292 u8 len_a = skb_metadata_len(skb_a);
4293 u8 len_b = skb_metadata_len(skb_b);
4294
4295 if (!(len_a | len_b))
4296 return false;
4297
4298 return len_a != len_b ?
4299 true : __skb_metadata_differs(skb_a, skb_b, len_a);
4300 }
4301
skb_metadata_set(struct sk_buff * skb,u8 meta_len)4302 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4303 {
4304 skb_shinfo(skb)->meta_len = meta_len;
4305 }
4306
skb_metadata_clear(struct sk_buff * skb)4307 static inline void skb_metadata_clear(struct sk_buff *skb)
4308 {
4309 skb_metadata_set(skb, 0);
4310 }
4311
4312 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
4313
4314 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4315
4316 void skb_clone_tx_timestamp(struct sk_buff *skb);
4317 bool skb_defer_rx_timestamp(struct sk_buff *skb);
4318
4319 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4320
skb_clone_tx_timestamp(struct sk_buff * skb)4321 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4322 {
4323 }
4324
skb_defer_rx_timestamp(struct sk_buff * skb)4325 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4326 {
4327 return false;
4328 }
4329
4330 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4331
4332 /**
4333 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4334 *
4335 * PHY drivers may accept clones of transmitted packets for
4336 * timestamping via their phy_driver.txtstamp method. These drivers
4337 * must call this function to return the skb back to the stack with a
4338 * timestamp.
4339 *
4340 * @skb: clone of the original outgoing packet
4341 * @hwtstamps: hardware time stamps
4342 *
4343 */
4344 void skb_complete_tx_timestamp(struct sk_buff *skb,
4345 struct skb_shared_hwtstamps *hwtstamps);
4346
4347 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
4348 struct skb_shared_hwtstamps *hwtstamps,
4349 struct sock *sk, int tstype);
4350
4351 /**
4352 * skb_tstamp_tx - queue clone of skb with send time stamps
4353 * @orig_skb: the original outgoing packet
4354 * @hwtstamps: hardware time stamps, may be NULL if not available
4355 *
4356 * If the skb has a socket associated, then this function clones the
4357 * skb (thus sharing the actual data and optional structures), stores
4358 * the optional hardware time stamping information (if non NULL) or
4359 * generates a software time stamp (otherwise), then queues the clone
4360 * to the error queue of the socket. Errors are silently ignored.
4361 */
4362 void skb_tstamp_tx(struct sk_buff *orig_skb,
4363 struct skb_shared_hwtstamps *hwtstamps);
4364
4365 /**
4366 * skb_tx_timestamp() - Driver hook for transmit timestamping
4367 *
4368 * Ethernet MAC Drivers should call this function in their hard_xmit()
4369 * function immediately before giving the sk_buff to the MAC hardware.
4370 *
4371 * Specifically, one should make absolutely sure that this function is
4372 * called before TX completion of this packet can trigger. Otherwise
4373 * the packet could potentially already be freed.
4374 *
4375 * @skb: A socket buffer.
4376 */
skb_tx_timestamp(struct sk_buff * skb)4377 static inline void skb_tx_timestamp(struct sk_buff *skb)
4378 {
4379 skb_clone_tx_timestamp(skb);
4380 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
4381 skb_tstamp_tx(skb, NULL);
4382 }
4383
4384 /**
4385 * skb_complete_wifi_ack - deliver skb with wifi status
4386 *
4387 * @skb: the original outgoing packet
4388 * @acked: ack status
4389 *
4390 */
4391 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4392
4393 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
4394 __sum16 __skb_checksum_complete(struct sk_buff *skb);
4395
skb_csum_unnecessary(const struct sk_buff * skb)4396 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4397 {
4398 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
4399 skb->csum_valid ||
4400 (skb->ip_summed == CHECKSUM_PARTIAL &&
4401 skb_checksum_start_offset(skb) >= 0));
4402 }
4403
4404 /**
4405 * skb_checksum_complete - Calculate checksum of an entire packet
4406 * @skb: packet to process
4407 *
4408 * This function calculates the checksum over the entire packet plus
4409 * the value of skb->csum. The latter can be used to supply the
4410 * checksum of a pseudo header as used by TCP/UDP. It returns the
4411 * checksum.
4412 *
4413 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
4414 * this function can be used to verify that checksum on received
4415 * packets. In that case the function should return zero if the
4416 * checksum is correct. In particular, this function will return zero
4417 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4418 * hardware has already verified the correctness of the checksum.
4419 */
skb_checksum_complete(struct sk_buff * skb)4420 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4421 {
4422 return skb_csum_unnecessary(skb) ?
4423 0 : __skb_checksum_complete(skb);
4424 }
4425
__skb_decr_checksum_unnecessary(struct sk_buff * skb)4426 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4427 {
4428 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4429 if (skb->csum_level == 0)
4430 skb->ip_summed = CHECKSUM_NONE;
4431 else
4432 skb->csum_level--;
4433 }
4434 }
4435
__skb_incr_checksum_unnecessary(struct sk_buff * skb)4436 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4437 {
4438 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4439 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4440 skb->csum_level++;
4441 } else if (skb->ip_summed == CHECKSUM_NONE) {
4442 skb->ip_summed = CHECKSUM_UNNECESSARY;
4443 skb->csum_level = 0;
4444 }
4445 }
4446
__skb_reset_checksum_unnecessary(struct sk_buff * skb)4447 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4448 {
4449 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4450 skb->ip_summed = CHECKSUM_NONE;
4451 skb->csum_level = 0;
4452 }
4453 }
4454
4455 /* Check if we need to perform checksum complete validation.
4456 *
4457 * Returns true if checksum complete is needed, false otherwise
4458 * (either checksum is unnecessary or zero checksum is allowed).
4459 */
__skb_checksum_validate_needed(struct sk_buff * skb,bool zero_okay,__sum16 check)4460 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4461 bool zero_okay,
4462 __sum16 check)
4463 {
4464 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4465 skb->csum_valid = 1;
4466 __skb_decr_checksum_unnecessary(skb);
4467 return false;
4468 }
4469
4470 return true;
4471 }
4472
4473 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4474 * in checksum_init.
4475 */
4476 #define CHECKSUM_BREAK 76
4477
4478 /* Unset checksum-complete
4479 *
4480 * Unset checksum complete can be done when packet is being modified
4481 * (uncompressed for instance) and checksum-complete value is
4482 * invalidated.
4483 */
skb_checksum_complete_unset(struct sk_buff * skb)4484 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4485 {
4486 if (skb->ip_summed == CHECKSUM_COMPLETE)
4487 skb->ip_summed = CHECKSUM_NONE;
4488 }
4489
4490 /* Validate (init) checksum based on checksum complete.
4491 *
4492 * Return values:
4493 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
4494 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4495 * checksum is stored in skb->csum for use in __skb_checksum_complete
4496 * non-zero: value of invalid checksum
4497 *
4498 */
__skb_checksum_validate_complete(struct sk_buff * skb,bool complete,__wsum psum)4499 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4500 bool complete,
4501 __wsum psum)
4502 {
4503 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4504 if (!csum_fold(csum_add(psum, skb->csum))) {
4505 skb->csum_valid = 1;
4506 return 0;
4507 }
4508 }
4509
4510 skb->csum = psum;
4511
4512 if (complete || skb->len <= CHECKSUM_BREAK) {
4513 __sum16 csum;
4514
4515 csum = __skb_checksum_complete(skb);
4516 skb->csum_valid = !csum;
4517 return csum;
4518 }
4519
4520 return 0;
4521 }
4522
null_compute_pseudo(struct sk_buff * skb,int proto)4523 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4524 {
4525 return 0;
4526 }
4527
4528 /* Perform checksum validate (init). Note that this is a macro since we only
4529 * want to calculate the pseudo header which is an input function if necessary.
4530 * First we try to validate without any computation (checksum unnecessary) and
4531 * then calculate based on checksum complete calling the function to compute
4532 * pseudo header.
4533 *
4534 * Return values:
4535 * 0: checksum is validated or try to in skb_checksum_complete
4536 * non-zero: value of invalid checksum
4537 */
4538 #define __skb_checksum_validate(skb, proto, complete, \
4539 zero_okay, check, compute_pseudo) \
4540 ({ \
4541 __sum16 __ret = 0; \
4542 skb->csum_valid = 0; \
4543 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4544 __ret = __skb_checksum_validate_complete(skb, \
4545 complete, compute_pseudo(skb, proto)); \
4546 __ret; \
4547 })
4548
4549 #define skb_checksum_init(skb, proto, compute_pseudo) \
4550 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4551
4552 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4553 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4554
4555 #define skb_checksum_validate(skb, proto, compute_pseudo) \
4556 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4557
4558 #define skb_checksum_validate_zero_check(skb, proto, check, \
4559 compute_pseudo) \
4560 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4561
4562 #define skb_checksum_simple_validate(skb) \
4563 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4564
__skb_checksum_convert_check(struct sk_buff * skb)4565 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4566 {
4567 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4568 }
4569
__skb_checksum_convert(struct sk_buff * skb,__wsum pseudo)4570 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4571 {
4572 skb->csum = ~pseudo;
4573 skb->ip_summed = CHECKSUM_COMPLETE;
4574 }
4575
4576 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4577 do { \
4578 if (__skb_checksum_convert_check(skb)) \
4579 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4580 } while (0)
4581
skb_remcsum_adjust_partial(struct sk_buff * skb,void * ptr,u16 start,u16 offset)4582 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4583 u16 start, u16 offset)
4584 {
4585 skb->ip_summed = CHECKSUM_PARTIAL;
4586 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4587 skb->csum_offset = offset - start;
4588 }
4589
4590 /* Update skbuf and packet to reflect the remote checksum offload operation.
4591 * When called, ptr indicates the starting point for skb->csum when
4592 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4593 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4594 */
skb_remcsum_process(struct sk_buff * skb,void * ptr,int start,int offset,bool nopartial)4595 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4596 int start, int offset, bool nopartial)
4597 {
4598 __wsum delta;
4599
4600 if (!nopartial) {
4601 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4602 return;
4603 }
4604
4605 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4606 __skb_checksum_complete(skb);
4607 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4608 }
4609
4610 delta = remcsum_adjust(ptr, skb->csum, start, offset);
4611
4612 /* Adjust skb->csum since we changed the packet */
4613 skb->csum = csum_add(skb->csum, delta);
4614 }
4615
skb_nfct(const struct sk_buff * skb)4616 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4617 {
4618 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4619 return (void *)(skb->_nfct & NFCT_PTRMASK);
4620 #else
4621 return NULL;
4622 #endif
4623 }
4624
skb_get_nfct(const struct sk_buff * skb)4625 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4626 {
4627 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4628 return skb->_nfct;
4629 #else
4630 return 0UL;
4631 #endif
4632 }
4633
skb_set_nfct(struct sk_buff * skb,unsigned long nfct)4634 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4635 {
4636 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4637 skb->slow_gro |= !!nfct;
4638 skb->_nfct = nfct;
4639 #endif
4640 }
4641
4642 #ifdef CONFIG_SKB_EXTENSIONS
4643 enum skb_ext_id {
4644 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4645 SKB_EXT_BRIDGE_NF,
4646 #endif
4647 #ifdef CONFIG_XFRM
4648 SKB_EXT_SEC_PATH,
4649 #endif
4650 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4651 TC_SKB_EXT,
4652 #endif
4653 #if IS_ENABLED(CONFIG_MPTCP)
4654 SKB_EXT_MPTCP,
4655 #endif
4656 #if IS_ENABLED(CONFIG_MCTP_FLOWS)
4657 SKB_EXT_MCTP,
4658 #endif
4659 SKB_EXT_NUM, /* must be last */
4660 };
4661
4662 /**
4663 * struct skb_ext - sk_buff extensions
4664 * @refcnt: 1 on allocation, deallocated on 0
4665 * @offset: offset to add to @data to obtain extension address
4666 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4667 * @data: start of extension data, variable sized
4668 *
4669 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4670 * to use 'u8' types while allowing up to 2kb worth of extension data.
4671 */
4672 struct skb_ext {
4673 refcount_t refcnt;
4674 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4675 u8 chunks; /* same */
4676 char data[] __aligned(8);
4677 };
4678
4679 struct skb_ext *__skb_ext_alloc(gfp_t flags);
4680 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4681 struct skb_ext *ext);
4682 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4683 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4684 void __skb_ext_put(struct skb_ext *ext);
4685
skb_ext_put(struct sk_buff * skb)4686 static inline void skb_ext_put(struct sk_buff *skb)
4687 {
4688 if (skb->active_extensions)
4689 __skb_ext_put(skb->extensions);
4690 }
4691
__skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4692 static inline void __skb_ext_copy(struct sk_buff *dst,
4693 const struct sk_buff *src)
4694 {
4695 dst->active_extensions = src->active_extensions;
4696
4697 if (src->active_extensions) {
4698 struct skb_ext *ext = src->extensions;
4699
4700 refcount_inc(&ext->refcnt);
4701 dst->extensions = ext;
4702 }
4703 }
4704
skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4705 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4706 {
4707 skb_ext_put(dst);
4708 __skb_ext_copy(dst, src);
4709 }
4710
__skb_ext_exist(const struct skb_ext * ext,enum skb_ext_id i)4711 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4712 {
4713 return !!ext->offset[i];
4714 }
4715
skb_ext_exist(const struct sk_buff * skb,enum skb_ext_id id)4716 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4717 {
4718 return skb->active_extensions & (1 << id);
4719 }
4720
skb_ext_del(struct sk_buff * skb,enum skb_ext_id id)4721 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4722 {
4723 if (skb_ext_exist(skb, id))
4724 __skb_ext_del(skb, id);
4725 }
4726
skb_ext_find(const struct sk_buff * skb,enum skb_ext_id id)4727 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4728 {
4729 if (skb_ext_exist(skb, id)) {
4730 struct skb_ext *ext = skb->extensions;
4731
4732 return (void *)ext + (ext->offset[id] << 3);
4733 }
4734
4735 return NULL;
4736 }
4737
skb_ext_reset(struct sk_buff * skb)4738 static inline void skb_ext_reset(struct sk_buff *skb)
4739 {
4740 if (unlikely(skb->active_extensions)) {
4741 __skb_ext_put(skb->extensions);
4742 skb->active_extensions = 0;
4743 }
4744 }
4745
skb_has_extensions(struct sk_buff * skb)4746 static inline bool skb_has_extensions(struct sk_buff *skb)
4747 {
4748 return unlikely(skb->active_extensions);
4749 }
4750 #else
skb_ext_put(struct sk_buff * skb)4751 static inline void skb_ext_put(struct sk_buff *skb) {}
skb_ext_reset(struct sk_buff * skb)4752 static inline void skb_ext_reset(struct sk_buff *skb) {}
skb_ext_del(struct sk_buff * skb,int unused)4753 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
__skb_ext_copy(struct sk_buff * d,const struct sk_buff * s)4754 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
skb_ext_copy(struct sk_buff * dst,const struct sk_buff * s)4755 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
skb_has_extensions(struct sk_buff * skb)4756 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4757 #endif /* CONFIG_SKB_EXTENSIONS */
4758
nf_reset_ct(struct sk_buff * skb)4759 static inline void nf_reset_ct(struct sk_buff *skb)
4760 {
4761 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4762 nf_conntrack_put(skb_nfct(skb));
4763 skb->_nfct = 0;
4764 #endif
4765 }
4766
nf_reset_trace(struct sk_buff * skb)4767 static inline void nf_reset_trace(struct sk_buff *skb)
4768 {
4769 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4770 skb->nf_trace = 0;
4771 #endif
4772 }
4773
ipvs_reset(struct sk_buff * skb)4774 static inline void ipvs_reset(struct sk_buff *skb)
4775 {
4776 #if IS_ENABLED(CONFIG_IP_VS)
4777 skb->ipvs_property = 0;
4778 #endif
4779 }
4780
4781 /* Note: This doesn't put any conntrack info in dst. */
__nf_copy(struct sk_buff * dst,const struct sk_buff * src,bool copy)4782 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4783 bool copy)
4784 {
4785 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4786 dst->_nfct = src->_nfct;
4787 nf_conntrack_get(skb_nfct(src));
4788 #endif
4789 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES)
4790 if (copy)
4791 dst->nf_trace = src->nf_trace;
4792 #endif
4793 }
4794
nf_copy(struct sk_buff * dst,const struct sk_buff * src)4795 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4796 {
4797 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4798 nf_conntrack_put(skb_nfct(dst));
4799 #endif
4800 dst->slow_gro = src->slow_gro;
4801 __nf_copy(dst, src, true);
4802 }
4803
4804 #ifdef CONFIG_NETWORK_SECMARK
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4805 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4806 {
4807 to->secmark = from->secmark;
4808 }
4809
skb_init_secmark(struct sk_buff * skb)4810 static inline void skb_init_secmark(struct sk_buff *skb)
4811 {
4812 skb->secmark = 0;
4813 }
4814 #else
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4815 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4816 { }
4817
skb_init_secmark(struct sk_buff * skb)4818 static inline void skb_init_secmark(struct sk_buff *skb)
4819 { }
4820 #endif
4821
secpath_exists(const struct sk_buff * skb)4822 static inline int secpath_exists(const struct sk_buff *skb)
4823 {
4824 #ifdef CONFIG_XFRM
4825 return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4826 #else
4827 return 0;
4828 #endif
4829 }
4830
skb_irq_freeable(const struct sk_buff * skb)4831 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4832 {
4833 return !skb->destructor &&
4834 !secpath_exists(skb) &&
4835 !skb_nfct(skb) &&
4836 !skb->_skb_refdst &&
4837 !skb_has_frag_list(skb);
4838 }
4839
skb_set_queue_mapping(struct sk_buff * skb,u16 queue_mapping)4840 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4841 {
4842 skb->queue_mapping = queue_mapping;
4843 }
4844
skb_get_queue_mapping(const struct sk_buff * skb)4845 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4846 {
4847 return skb->queue_mapping;
4848 }
4849
skb_copy_queue_mapping(struct sk_buff * to,const struct sk_buff * from)4850 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4851 {
4852 to->queue_mapping = from->queue_mapping;
4853 }
4854
skb_record_rx_queue(struct sk_buff * skb,u16 rx_queue)4855 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4856 {
4857 skb->queue_mapping = rx_queue + 1;
4858 }
4859
skb_get_rx_queue(const struct sk_buff * skb)4860 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4861 {
4862 return skb->queue_mapping - 1;
4863 }
4864
skb_rx_queue_recorded(const struct sk_buff * skb)4865 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4866 {
4867 return skb->queue_mapping != 0;
4868 }
4869
skb_set_dst_pending_confirm(struct sk_buff * skb,u32 val)4870 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4871 {
4872 skb->dst_pending_confirm = val;
4873 }
4874
skb_get_dst_pending_confirm(const struct sk_buff * skb)4875 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4876 {
4877 return skb->dst_pending_confirm != 0;
4878 }
4879
skb_sec_path(const struct sk_buff * skb)4880 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4881 {
4882 #ifdef CONFIG_XFRM
4883 return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4884 #else
4885 return NULL;
4886 #endif
4887 }
4888
skb_is_gso(const struct sk_buff * skb)4889 static inline bool skb_is_gso(const struct sk_buff *skb)
4890 {
4891 return skb_shinfo(skb)->gso_size;
4892 }
4893
4894 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_v6(const struct sk_buff * skb)4895 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4896 {
4897 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4898 }
4899
4900 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_sctp(const struct sk_buff * skb)4901 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4902 {
4903 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4904 }
4905
4906 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_tcp(const struct sk_buff * skb)4907 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4908 {
4909 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
4910 }
4911
skb_gso_reset(struct sk_buff * skb)4912 static inline void skb_gso_reset(struct sk_buff *skb)
4913 {
4914 skb_shinfo(skb)->gso_size = 0;
4915 skb_shinfo(skb)->gso_segs = 0;
4916 skb_shinfo(skb)->gso_type = 0;
4917 }
4918
skb_increase_gso_size(struct skb_shared_info * shinfo,u16 increment)4919 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
4920 u16 increment)
4921 {
4922 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4923 return;
4924 shinfo->gso_size += increment;
4925 }
4926
skb_decrease_gso_size(struct skb_shared_info * shinfo,u16 decrement)4927 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
4928 u16 decrement)
4929 {
4930 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4931 return;
4932 shinfo->gso_size -= decrement;
4933 }
4934
4935 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
4936
skb_warn_if_lro(const struct sk_buff * skb)4937 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
4938 {
4939 /* LRO sets gso_size but not gso_type, whereas if GSO is really
4940 * wanted then gso_type will be set. */
4941 const struct skb_shared_info *shinfo = skb_shinfo(skb);
4942
4943 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
4944 unlikely(shinfo->gso_type == 0)) {
4945 __skb_warn_lro_forwarding(skb);
4946 return true;
4947 }
4948 return false;
4949 }
4950
skb_forward_csum(struct sk_buff * skb)4951 static inline void skb_forward_csum(struct sk_buff *skb)
4952 {
4953 /* Unfortunately we don't support this one. Any brave souls? */
4954 if (skb->ip_summed == CHECKSUM_COMPLETE)
4955 skb->ip_summed = CHECKSUM_NONE;
4956 }
4957
4958 /**
4959 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4960 * @skb: skb to check
4961 *
4962 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4963 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4964 * use this helper, to document places where we make this assertion.
4965 */
skb_checksum_none_assert(const struct sk_buff * skb)4966 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
4967 {
4968 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
4969 }
4970
4971 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
4972
4973 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
4974 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
4975 unsigned int transport_len,
4976 __sum16(*skb_chkf)(struct sk_buff *skb));
4977
4978 /**
4979 * skb_head_is_locked - Determine if the skb->head is locked down
4980 * @skb: skb to check
4981 *
4982 * The head on skbs build around a head frag can be removed if they are
4983 * not cloned. This function returns true if the skb head is locked down
4984 * due to either being allocated via kmalloc, or by being a clone with
4985 * multiple references to the head.
4986 */
skb_head_is_locked(const struct sk_buff * skb)4987 static inline bool skb_head_is_locked(const struct sk_buff *skb)
4988 {
4989 return !skb->head_frag || skb_cloned(skb);
4990 }
4991
4992 /* Local Checksum Offload.
4993 * Compute outer checksum based on the assumption that the
4994 * inner checksum will be offloaded later.
4995 * See Documentation/networking/checksum-offloads.rst for
4996 * explanation of how this works.
4997 * Fill in outer checksum adjustment (e.g. with sum of outer
4998 * pseudo-header) before calling.
4999 * Also ensure that inner checksum is in linear data area.
5000 */
lco_csum(struct sk_buff * skb)5001 static inline __wsum lco_csum(struct sk_buff *skb)
5002 {
5003 unsigned char *csum_start = skb_checksum_start(skb);
5004 unsigned char *l4_hdr = skb_transport_header(skb);
5005 __wsum partial;
5006
5007 /* Start with complement of inner checksum adjustment */
5008 partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
5009 skb->csum_offset));
5010
5011 /* Add in checksum of our headers (incl. outer checksum
5012 * adjustment filled in by caller) and return result.
5013 */
5014 return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
5015 }
5016
skb_is_redirected(const struct sk_buff * skb)5017 static inline bool skb_is_redirected(const struct sk_buff *skb)
5018 {
5019 return skb->redirected;
5020 }
5021
skb_set_redirected(struct sk_buff * skb,bool from_ingress)5022 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
5023 {
5024 skb->redirected = 1;
5025 #ifdef CONFIG_NET_REDIRECT
5026 skb->from_ingress = from_ingress;
5027 if (skb->from_ingress)
5028 skb_clear_tstamp(skb);
5029 #endif
5030 }
5031
skb_reset_redirect(struct sk_buff * skb)5032 static inline void skb_reset_redirect(struct sk_buff *skb)
5033 {
5034 skb->redirected = 0;
5035 }
5036
skb_set_redirected_noclear(struct sk_buff * skb,bool from_ingress)5037 static inline void skb_set_redirected_noclear(struct sk_buff *skb,
5038 bool from_ingress)
5039 {
5040 skb->redirected = 1;
5041 #ifdef CONFIG_NET_REDIRECT
5042 skb->from_ingress = from_ingress;
5043 #endif
5044 }
5045
skb_csum_is_sctp(struct sk_buff * skb)5046 static inline bool skb_csum_is_sctp(struct sk_buff *skb)
5047 {
5048 #if IS_ENABLED(CONFIG_IP_SCTP)
5049 return skb->csum_not_inet;
5050 #else
5051 return 0;
5052 #endif
5053 }
5054
skb_reset_csum_not_inet(struct sk_buff * skb)5055 static inline void skb_reset_csum_not_inet(struct sk_buff *skb)
5056 {
5057 skb->ip_summed = CHECKSUM_NONE;
5058 #if IS_ENABLED(CONFIG_IP_SCTP)
5059 skb->csum_not_inet = 0;
5060 #endif
5061 }
5062
skb_set_kcov_handle(struct sk_buff * skb,const u64 kcov_handle)5063 static inline void skb_set_kcov_handle(struct sk_buff *skb,
5064 const u64 kcov_handle)
5065 {
5066 #ifdef CONFIG_KCOV
5067 skb->kcov_handle = kcov_handle;
5068 #endif
5069 }
5070
skb_get_kcov_handle(struct sk_buff * skb)5071 static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
5072 {
5073 #ifdef CONFIG_KCOV
5074 return skb->kcov_handle;
5075 #else
5076 return 0;
5077 #endif
5078 }
5079
skb_mark_for_recycle(struct sk_buff * skb)5080 static inline void skb_mark_for_recycle(struct sk_buff *skb)
5081 {
5082 #ifdef CONFIG_PAGE_POOL
5083 skb->pp_recycle = 1;
5084 #endif
5085 }
5086
5087 ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter,
5088 ssize_t maxsize, gfp_t gfp);
5089
5090 #endif /* __KERNEL__ */
5091 #endif /* _LINUX_SKBUFF_H */
5092