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 <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/hrtimer.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/netdev_features.h>
33 #include <linux/sched.h>
34 #include <linux/sched/clock.h>
35 #include <net/flow_dissector.h>
36 #include <linux/splice.h>
37 #include <linux/in6.h>
38 #include <linux/if_packet.h>
39 #include <net/flow.h>
40 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
41 #include <linux/netfilter/nf_conntrack_common.h>
42 #endif
43
44 /* The interface for checksum offload between the stack and networking drivers
45 * is as follows...
46 *
47 * A. IP checksum related features
48 *
49 * Drivers advertise checksum offload capabilities in the features of a device.
50 * From the stack's point of view these are capabilities offered by the driver.
51 * A driver typically only advertises features that it is capable of offloading
52 * to its device.
53 *
54 * The checksum related features are:
55 *
56 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
57 * IP (one's complement) checksum for any combination
58 * of protocols or protocol layering. The checksum is
59 * computed and set in a packet per the CHECKSUM_PARTIAL
60 * interface (see below).
61 *
62 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
63 * TCP or UDP packets over IPv4. These are specifically
64 * unencapsulated packets of the form IPv4|TCP or
65 * IPv4|UDP where the Protocol field in the IPv4 header
66 * is TCP or UDP. The IPv4 header may contain IP options.
67 * This feature cannot be set in features for a device
68 * with NETIF_F_HW_CSUM also set. This feature is being
69 * DEPRECATED (see below).
70 *
71 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
72 * TCP or UDP packets over IPv6. These are specifically
73 * unencapsulated packets of the form IPv6|TCP or
74 * IPv6|UDP where the Next Header field in the IPv6
75 * header is either TCP or UDP. IPv6 extension headers
76 * are not supported with this feature. This feature
77 * cannot be set in features for a device with
78 * NETIF_F_HW_CSUM also set. This feature is being
79 * DEPRECATED (see below).
80 *
81 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
82 * This flag is only used to disable the RX checksum
83 * feature for a device. The stack will accept receive
84 * checksum indication in packets received on a device
85 * regardless of whether NETIF_F_RXCSUM is set.
86 *
87 * B. Checksumming of received packets by device. Indication of checksum
88 * verification is set in skb->ip_summed. Possible values are:
89 *
90 * CHECKSUM_NONE:
91 *
92 * Device did not checksum this packet e.g. due to lack of capabilities.
93 * The packet contains full (though not verified) checksum in packet but
94 * not in skb->csum. Thus, skb->csum is undefined in this case.
95 *
96 * CHECKSUM_UNNECESSARY:
97 *
98 * The hardware you're dealing with doesn't calculate the full checksum
99 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
100 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
101 * if their checksums are okay. skb->csum is still undefined in this case
102 * though. A driver or device must never modify the checksum field in the
103 * packet even if checksum is verified.
104 *
105 * CHECKSUM_UNNECESSARY is applicable to following protocols:
106 * TCP: IPv6 and IPv4.
107 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
108 * zero UDP checksum for either IPv4 or IPv6, the networking stack
109 * may perform further validation in this case.
110 * GRE: only if the checksum is present in the header.
111 * SCTP: indicates the CRC in SCTP header has been validated.
112 * FCOE: indicates the CRC in FC frame has been validated.
113 *
114 * skb->csum_level indicates the number of consecutive checksums found in
115 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
116 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
117 * and a device is able to verify the checksums for UDP (possibly zero),
118 * GRE (checksum flag is set) and TCP, skb->csum_level would be set to
119 * two. If the device were only able to verify the UDP checksum and not
120 * GRE, either because it doesn't support GRE checksum or because GRE
121 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
122 * not considered in this case).
123 *
124 * CHECKSUM_COMPLETE:
125 *
126 * This is the most generic way. The device supplied checksum of the _whole_
127 * packet as seen by netif_rx() and fills in skb->csum. This means the
128 * hardware doesn't need to parse L3/L4 headers to implement this.
129 *
130 * Notes:
131 * - Even if device supports only some protocols, but is able to produce
132 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
133 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
134 *
135 * CHECKSUM_PARTIAL:
136 *
137 * A checksum is set up to be offloaded to a device as described in the
138 * output description for CHECKSUM_PARTIAL. This may occur on a packet
139 * received directly from another Linux OS, e.g., a virtualized Linux kernel
140 * on the same host, or it may be set in the input path in GRO or remote
141 * checksum offload. For the purposes of checksum verification, the checksum
142 * referred to by skb->csum_start + skb->csum_offset and any preceding
143 * checksums in the packet are considered verified. Any checksums in the
144 * packet that are after the checksum being offloaded are not considered to
145 * be verified.
146 *
147 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
148 * in the skb->ip_summed for a packet. Values are:
149 *
150 * CHECKSUM_PARTIAL:
151 *
152 * The driver is required to checksum the packet as seen by hard_start_xmit()
153 * from skb->csum_start up to the end, and to record/write the checksum at
154 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
155 * csum_start and csum_offset values are valid values given the length and
156 * offset of the packet, but it should not attempt to validate that the
157 * checksum refers to a legitimate transport layer checksum -- it is the
158 * purview of the stack to validate that csum_start and csum_offset are set
159 * correctly.
160 *
161 * When the stack requests checksum offload for a packet, the driver MUST
162 * ensure that the checksum is set correctly. A driver can either offload the
163 * checksum calculation to the device, or call skb_checksum_help (in the case
164 * that the device does not support offload for a particular checksum).
165 *
166 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
167 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
168 * checksum offload capability.
169 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
170 * on network device checksumming capabilities: if a packet does not match
171 * them, skb_checksum_help or skb_crc32c_help (depending on the value of
172 * csum_not_inet, see item D.) is called to resolve the checksum.
173 *
174 * CHECKSUM_NONE:
175 *
176 * The skb was already checksummed by the protocol, or a checksum is not
177 * required.
178 *
179 * CHECKSUM_UNNECESSARY:
180 *
181 * This has the same meaning as CHECKSUM_NONE for checksum offload on
182 * output.
183 *
184 * CHECKSUM_COMPLETE:
185 * Not used in checksum output. If a driver observes a packet with this value
186 * set in skbuff, it should treat the packet as if CHECKSUM_NONE were set.
187 *
188 * D. Non-IP checksum (CRC) offloads
189 *
190 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
191 * offloading the SCTP CRC in a packet. To perform this offload the stack
192 * will set csum_start and csum_offset accordingly, set ip_summed to
193 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
194 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
195 * A driver that supports both IP checksum offload and SCTP CRC32c offload
196 * must verify which offload is configured for a packet by testing the
197 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
198 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
199 *
200 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
201 * offloading the FCOE CRC in a packet. To perform this offload the stack
202 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
203 * accordingly. Note that there is no indication in the skbuff that the
204 * CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
205 * both IP checksum offload and FCOE CRC offload must verify which offload
206 * is configured for a packet, presumably by inspecting packet headers.
207 *
208 * E. Checksumming on output with GSO.
209 *
210 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
211 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
212 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
213 * part of the GSO operation is implied. If a checksum is being offloaded
214 * with GSO then ip_summed is CHECKSUM_PARTIAL, and both csum_start and
215 * csum_offset are set to refer to the outermost checksum being offloaded
216 * (two offloaded checksums are possible with UDP encapsulation).
217 */
218
219 /* Don't change this without changing skb_csum_unnecessary! */
220 #define CHECKSUM_NONE 0
221 #define CHECKSUM_UNNECESSARY 1
222 #define CHECKSUM_COMPLETE 2
223 #define CHECKSUM_PARTIAL 3
224
225 /* Maximum value in skb->csum_level */
226 #define SKB_MAX_CSUM_LEVEL 3
227
228 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
229 #define SKB_WITH_OVERHEAD(X) \
230 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
231 #define SKB_MAX_ORDER(X, ORDER) \
232 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
233 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
234 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
235
236 /* return minimum truesize of one skb containing X bytes of data */
237 #define SKB_TRUESIZE(X) ((X) + \
238 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
239 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
240
241 struct ahash_request;
242 struct net_device;
243 struct scatterlist;
244 struct pipe_inode_info;
245 struct iov_iter;
246 struct napi_struct;
247 struct bpf_prog;
248 union bpf_attr;
249 struct skb_ext;
250
251 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
252 struct nf_bridge_info {
253 enum {
254 BRNF_PROTO_UNCHANGED,
255 BRNF_PROTO_8021Q,
256 BRNF_PROTO_PPPOE
257 } orig_proto:8;
258 u8 pkt_otherhost:1;
259 u8 in_prerouting:1;
260 u8 bridged_dnat:1;
261 __u16 frag_max_size;
262 struct net_device *physindev;
263
264 /* always valid & non-NULL from FORWARD on, for physdev match */
265 struct net_device *physoutdev;
266 union {
267 /* prerouting: detect dnat in orig/reply direction */
268 __be32 ipv4_daddr;
269 struct in6_addr ipv6_daddr;
270
271 /* after prerouting + nat detected: store original source
272 * mac since neigh resolution overwrites it, only used while
273 * skb is out in neigh layer.
274 */
275 char neigh_header[8];
276 };
277 };
278 #endif
279
280 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
281 /* Chain in tc_skb_ext will be used to share the tc chain with
282 * ovs recirc_id. It will be set to the current chain by tc
283 * and read by ovs to recirc_id.
284 */
285 struct tc_skb_ext {
286 __u32 chain;
287 __u16 mru;
288 bool post_ct;
289 };
290 #endif
291
292 struct sk_buff_head {
293 /* These two members must be first. */
294 struct sk_buff *next;
295 struct sk_buff *prev;
296
297 __u32 qlen;
298 spinlock_t lock;
299 };
300
301 struct sk_buff;
302
303 /* To allow 64K frame to be packed as single skb without frag_list we
304 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
305 * buffers which do not start on a page boundary.
306 *
307 * Since GRO uses frags we allocate at least 16 regardless of page
308 * size.
309 */
310 #if (65536/PAGE_SIZE + 1) < 16
311 #define MAX_SKB_FRAGS 16UL
312 #else
313 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
314 #endif
315 extern int sysctl_max_skb_frags;
316
317 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
318 * segment using its current segmentation instead.
319 */
320 #define GSO_BY_FRAGS 0xFFFF
321
322 typedef struct bio_vec skb_frag_t;
323
324 /**
325 * skb_frag_size() - Returns the size of a skb fragment
326 * @frag: skb fragment
327 */
skb_frag_size(const skb_frag_t * frag)328 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
329 {
330 return frag->bv_len;
331 }
332
333 /**
334 * skb_frag_size_set() - Sets the size of a skb fragment
335 * @frag: skb fragment
336 * @size: size of fragment
337 */
skb_frag_size_set(skb_frag_t * frag,unsigned int size)338 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
339 {
340 frag->bv_len = size;
341 }
342
343 /**
344 * skb_frag_size_add() - Increments the size of a skb fragment by @delta
345 * @frag: skb fragment
346 * @delta: value to add
347 */
skb_frag_size_add(skb_frag_t * frag,int delta)348 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
349 {
350 frag->bv_len += delta;
351 }
352
353 /**
354 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
355 * @frag: skb fragment
356 * @delta: value to subtract
357 */
skb_frag_size_sub(skb_frag_t * frag,int delta)358 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
359 {
360 frag->bv_len -= delta;
361 }
362
363 /**
364 * skb_frag_must_loop - Test if %p is a high memory page
365 * @p: fragment's page
366 */
skb_frag_must_loop(struct page * p)367 static inline bool skb_frag_must_loop(struct page *p)
368 {
369 #if defined(CONFIG_HIGHMEM)
370 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
371 return true;
372 #endif
373 return false;
374 }
375
376 /**
377 * skb_frag_foreach_page - loop over pages in a fragment
378 *
379 * @f: skb frag to operate on
380 * @f_off: offset from start of f->bv_page
381 * @f_len: length from f_off to loop over
382 * @p: (temp var) current page
383 * @p_off: (temp var) offset from start of current page,
384 * non-zero only on first page.
385 * @p_len: (temp var) length in current page,
386 * < PAGE_SIZE only on first and last page.
387 * @copied: (temp var) length so far, excluding current p_len.
388 *
389 * A fragment can hold a compound page, in which case per-page
390 * operations, notably kmap_atomic, must be called for each
391 * regular page.
392 */
393 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
394 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
395 p_off = (f_off) & (PAGE_SIZE - 1), \
396 p_len = skb_frag_must_loop(p) ? \
397 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
398 copied = 0; \
399 copied < f_len; \
400 copied += p_len, p++, p_off = 0, \
401 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
402
403 #define HAVE_HW_TIME_STAMP
404
405 /**
406 * struct skb_shared_hwtstamps - hardware time stamps
407 * @hwtstamp: hardware time stamp transformed into duration
408 * since arbitrary point in time
409 *
410 * Software time stamps generated by ktime_get_real() are stored in
411 * skb->tstamp.
412 *
413 * hwtstamps can only be compared against other hwtstamps from
414 * the same device.
415 *
416 * This structure is attached to packets as part of the
417 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
418 */
419 struct skb_shared_hwtstamps {
420 ktime_t hwtstamp;
421 };
422
423 /* Definitions for tx_flags in struct skb_shared_info */
424 enum {
425 /* generate hardware time stamp */
426 SKBTX_HW_TSTAMP = 1 << 0,
427
428 /* generate software time stamp when queueing packet to NIC */
429 SKBTX_SW_TSTAMP = 1 << 1,
430
431 /* device driver is going to provide hardware time stamp */
432 SKBTX_IN_PROGRESS = 1 << 2,
433
434 /* generate wifi status information (where possible) */
435 SKBTX_WIFI_STATUS = 1 << 4,
436
437 /* generate software time stamp when entering packet scheduling */
438 SKBTX_SCHED_TSTAMP = 1 << 6,
439 };
440
441 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
442 SKBTX_SCHED_TSTAMP)
443 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
444
445 /* Definitions for flags in struct skb_shared_info */
446 enum {
447 /* use zcopy routines */
448 SKBFL_ZEROCOPY_ENABLE = BIT(0),
449
450 /* This indicates at least one fragment might be overwritten
451 * (as in vmsplice(), sendfile() ...)
452 * If we need to compute a TX checksum, we'll need to copy
453 * all frags to avoid possible bad checksum
454 */
455 SKBFL_SHARED_FRAG = BIT(1),
456 };
457
458 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
459
460 /*
461 * The callback notifies userspace to release buffers when skb DMA is done in
462 * lower device, the skb last reference should be 0 when calling this.
463 * The zerocopy_success argument is true if zero copy transmit occurred,
464 * false on data copy or out of memory error caused by data copy attempt.
465 * The ctx field is used to track device context.
466 * The desc field is used to track userspace buffer index.
467 */
468 struct ubuf_info {
469 void (*callback)(struct sk_buff *, struct ubuf_info *,
470 bool zerocopy_success);
471 union {
472 struct {
473 unsigned long desc;
474 void *ctx;
475 };
476 struct {
477 u32 id;
478 u16 len;
479 u16 zerocopy:1;
480 u32 bytelen;
481 };
482 };
483 refcount_t refcnt;
484 u8 flags;
485
486 struct mmpin {
487 struct user_struct *user;
488 unsigned int num_pg;
489 } mmp;
490 };
491
492 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
493
494 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
495 void mm_unaccount_pinned_pages(struct mmpin *mmp);
496
497 struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size);
498 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
499 struct ubuf_info *uarg);
500
501 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
502
503 void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
504 bool success);
505
506 int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len);
507 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
508 struct msghdr *msg, int len,
509 struct ubuf_info *uarg);
510
511 /* This data is invariant across clones and lives at
512 * the end of the header data, ie. at skb->end.
513 */
514 struct skb_shared_info {
515 __u8 flags;
516 __u8 meta_len;
517 __u8 nr_frags;
518 __u8 tx_flags;
519 unsigned short gso_size;
520 /* Warning: this field is not always filled in (UFO)! */
521 unsigned short gso_segs;
522 struct sk_buff *frag_list;
523 struct skb_shared_hwtstamps hwtstamps;
524 unsigned int gso_type;
525 u32 tskey;
526
527 /*
528 * Warning : all fields before dataref are cleared in __alloc_skb()
529 */
530 atomic_t dataref;
531
532 /* Intermediate layers must ensure that destructor_arg
533 * remains valid until skb destructor */
534 void * destructor_arg;
535
536 /* must be last field, see pskb_expand_head() */
537 skb_frag_t frags[MAX_SKB_FRAGS];
538 };
539
540 /* We divide dataref into two halves. The higher 16 bits hold references
541 * to the payload part of skb->data. The lower 16 bits hold references to
542 * the entire skb->data. A clone of a headerless skb holds the length of
543 * the header in skb->hdr_len.
544 *
545 * All users must obey the rule that the skb->data reference count must be
546 * greater than or equal to the payload reference count.
547 *
548 * Holding a reference to the payload part means that the user does not
549 * care about modifications to the header part of skb->data.
550 */
551 #define SKB_DATAREF_SHIFT 16
552 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
553
554
555 enum {
556 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
557 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
558 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
559 };
560
561 enum {
562 SKB_GSO_TCPV4 = 1 << 0,
563
564 /* This indicates the skb is from an untrusted source. */
565 SKB_GSO_DODGY = 1 << 1,
566
567 /* This indicates the tcp segment has CWR set. */
568 SKB_GSO_TCP_ECN = 1 << 2,
569
570 SKB_GSO_TCP_FIXEDID = 1 << 3,
571
572 SKB_GSO_TCPV6 = 1 << 4,
573
574 SKB_GSO_FCOE = 1 << 5,
575
576 SKB_GSO_GRE = 1 << 6,
577
578 SKB_GSO_GRE_CSUM = 1 << 7,
579
580 SKB_GSO_IPXIP4 = 1 << 8,
581
582 SKB_GSO_IPXIP6 = 1 << 9,
583
584 SKB_GSO_UDP_TUNNEL = 1 << 10,
585
586 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
587
588 SKB_GSO_PARTIAL = 1 << 12,
589
590 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
591
592 SKB_GSO_SCTP = 1 << 14,
593
594 SKB_GSO_ESP = 1 << 15,
595
596 SKB_GSO_UDP = 1 << 16,
597
598 SKB_GSO_UDP_L4 = 1 << 17,
599
600 SKB_GSO_FRAGLIST = 1 << 18,
601 };
602
603 #if BITS_PER_LONG > 32
604 #define NET_SKBUFF_DATA_USES_OFFSET 1
605 #endif
606
607 #ifdef NET_SKBUFF_DATA_USES_OFFSET
608 typedef unsigned int sk_buff_data_t;
609 #else
610 typedef unsigned char *sk_buff_data_t;
611 #endif
612
613 /**
614 * struct sk_buff - socket buffer
615 * @next: Next buffer in list
616 * @prev: Previous buffer in list
617 * @tstamp: Time we arrived/left
618 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
619 * for retransmit timer
620 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
621 * @list: queue head
622 * @sk: Socket we are owned by
623 * @ip_defrag_offset: (aka @sk) alternate use of @sk, used in
624 * fragmentation management
625 * @dev: Device we arrived on/are leaving by
626 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
627 * @cb: Control buffer. Free for use by every layer. Put private vars here
628 * @_skb_refdst: destination entry (with norefcount bit)
629 * @sp: the security path, used for xfrm
630 * @len: Length of actual data
631 * @data_len: Data length
632 * @mac_len: Length of link layer header
633 * @hdr_len: writable header length of cloned skb
634 * @csum: Checksum (must include start/offset pair)
635 * @csum_start: Offset from skb->head where checksumming should start
636 * @csum_offset: Offset from csum_start where checksum should be stored
637 * @priority: Packet queueing priority
638 * @ignore_df: allow local fragmentation
639 * @cloned: Head may be cloned (check refcnt to be sure)
640 * @ip_summed: Driver fed us an IP checksum
641 * @nohdr: Payload reference only, must not modify header
642 * @pkt_type: Packet class
643 * @fclone: skbuff clone status
644 * @ipvs_property: skbuff is owned by ipvs
645 * @inner_protocol_type: whether the inner protocol is
646 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
647 * @remcsum_offload: remote checksum offload is enabled
648 * @offload_fwd_mark: Packet was L2-forwarded in hardware
649 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
650 * @tc_skip_classify: do not classify packet. set by IFB device
651 * @tc_at_ingress: used within tc_classify to distinguish in/egress
652 * @redirected: packet was redirected by packet classifier
653 * @from_ingress: packet was redirected from the ingress path
654 * @peeked: this packet has been seen already, so stats have been
655 * done for it, don't do them again
656 * @nf_trace: netfilter packet trace flag
657 * @protocol: Packet protocol from driver
658 * @destructor: Destruct function
659 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
660 * @_sk_redir: socket redirection information for skmsg
661 * @_nfct: Associated connection, if any (with nfctinfo bits)
662 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
663 * @skb_iif: ifindex of device we arrived on
664 * @tc_index: Traffic control index
665 * @hash: the packet hash
666 * @queue_mapping: Queue mapping for multiqueue devices
667 * @head_frag: skb was allocated from page fragments,
668 * not allocated by kmalloc() or vmalloc().
669 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
670 * @active_extensions: active extensions (skb_ext_id types)
671 * @ndisc_nodetype: router type (from link layer)
672 * @ooo_okay: allow the mapping of a socket to a queue to be changed
673 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
674 * ports.
675 * @sw_hash: indicates hash was computed in software stack
676 * @wifi_acked_valid: wifi_acked was set
677 * @wifi_acked: whether frame was acked on wifi or not
678 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
679 * @encapsulation: indicates the inner headers in the skbuff are valid
680 * @encap_hdr_csum: software checksum is needed
681 * @csum_valid: checksum is already valid
682 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
683 * @csum_complete_sw: checksum was completed by software
684 * @csum_level: indicates the number of consecutive checksums found in
685 * the packet minus one that have been verified as
686 * CHECKSUM_UNNECESSARY (max 3)
687 * @dst_pending_confirm: need to confirm neighbour
688 * @decrypted: Decrypted SKB
689 * @napi_id: id of the NAPI struct this skb came from
690 * @sender_cpu: (aka @napi_id) source CPU in XPS
691 * @secmark: security marking
692 * @mark: Generic packet mark
693 * @reserved_tailroom: (aka @mark) number of bytes of free space available
694 * at the tail of an sk_buff
695 * @vlan_present: VLAN tag is present
696 * @vlan_proto: vlan encapsulation protocol
697 * @vlan_tci: vlan tag control information
698 * @inner_protocol: Protocol (encapsulation)
699 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
700 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
701 * @inner_transport_header: Inner transport layer header (encapsulation)
702 * @inner_network_header: Network layer header (encapsulation)
703 * @inner_mac_header: Link layer header (encapsulation)
704 * @transport_header: Transport layer header
705 * @network_header: Network layer header
706 * @mac_header: Link layer header
707 * @kcov_handle: KCOV remote handle for remote coverage collection
708 * @tail: Tail pointer
709 * @end: End pointer
710 * @head: Head of buffer
711 * @data: Data head pointer
712 * @truesize: Buffer size
713 * @users: User count - see {datagram,tcp}.c
714 * @extensions: allocated extensions, valid if active_extensions is nonzero
715 */
716
717 struct sk_buff {
718 union {
719 struct {
720 /* These two members must be first. */
721 struct sk_buff *next;
722 struct sk_buff *prev;
723
724 union {
725 struct net_device *dev;
726 /* Some protocols might use this space to store information,
727 * while device pointer would be NULL.
728 * UDP receive path is one user.
729 */
730 unsigned long dev_scratch;
731 };
732 };
733 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
734 struct list_head list;
735 };
736
737 union {
738 struct sock *sk;
739 int ip_defrag_offset;
740 };
741
742 union {
743 ktime_t tstamp;
744 u64 skb_mstamp_ns; /* earliest departure time */
745 };
746 /*
747 * This is the control buffer. It is free to use for every
748 * layer. Please put your private variables there. If you
749 * want to keep them across layers you have to do a skb_clone()
750 * first. This is owned by whoever has the skb queued ATM.
751 */
752 char cb[48] __aligned(8);
753
754 union {
755 struct {
756 unsigned long _skb_refdst;
757 void (*destructor)(struct sk_buff *skb);
758 };
759 struct list_head tcp_tsorted_anchor;
760 #ifdef CONFIG_NET_SOCK_MSG
761 unsigned long _sk_redir;
762 #endif
763 };
764
765 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
766 unsigned long _nfct;
767 #endif
768 unsigned int len,
769 data_len;
770 __u16 mac_len,
771 hdr_len;
772
773 /* Following fields are _not_ copied in __copy_skb_header()
774 * Note that queue_mapping is here mostly to fill a hole.
775 */
776 __u16 queue_mapping;
777
778 /* if you move cloned around you also must adapt those constants */
779 #ifdef __BIG_ENDIAN_BITFIELD
780 #define CLONED_MASK (1 << 7)
781 #else
782 #define CLONED_MASK 1
783 #endif
784 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
785
786 /* private: */
787 __u8 __cloned_offset[0];
788 /* public: */
789 __u8 cloned:1,
790 nohdr:1,
791 fclone:2,
792 peeked:1,
793 head_frag:1,
794 pfmemalloc:1;
795 #ifdef CONFIG_SKB_EXTENSIONS
796 __u8 active_extensions;
797 #endif
798 /* fields enclosed in headers_start/headers_end are copied
799 * using a single memcpy() in __copy_skb_header()
800 */
801 /* private: */
802 __u32 headers_start[0];
803 /* public: */
804
805 /* if you move pkt_type around you also must adapt those constants */
806 #ifdef __BIG_ENDIAN_BITFIELD
807 #define PKT_TYPE_MAX (7 << 5)
808 #else
809 #define PKT_TYPE_MAX 7
810 #endif
811 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
812
813 /* private: */
814 __u8 __pkt_type_offset[0];
815 /* public: */
816 __u8 pkt_type:3;
817 __u8 ignore_df:1;
818 __u8 nf_trace:1;
819 __u8 ip_summed:2;
820 __u8 ooo_okay:1;
821
822 __u8 l4_hash:1;
823 __u8 sw_hash:1;
824 __u8 wifi_acked_valid:1;
825 __u8 wifi_acked:1;
826 __u8 no_fcs:1;
827 /* Indicates the inner headers are valid in the skbuff. */
828 __u8 encapsulation:1;
829 __u8 encap_hdr_csum:1;
830 __u8 csum_valid:1;
831
832 #ifdef __BIG_ENDIAN_BITFIELD
833 #define PKT_VLAN_PRESENT_BIT 7
834 #else
835 #define PKT_VLAN_PRESENT_BIT 0
836 #endif
837 #define PKT_VLAN_PRESENT_OFFSET() offsetof(struct sk_buff, __pkt_vlan_present_offset)
838 /* private: */
839 __u8 __pkt_vlan_present_offset[0];
840 /* public: */
841 __u8 vlan_present:1;
842 __u8 csum_complete_sw:1;
843 __u8 csum_level:2;
844 __u8 csum_not_inet:1;
845 __u8 dst_pending_confirm:1;
846 #ifdef CONFIG_IPV6_NDISC_NODETYPE
847 __u8 ndisc_nodetype:2;
848 #endif
849
850 __u8 ipvs_property:1;
851 __u8 inner_protocol_type:1;
852 __u8 remcsum_offload:1;
853 #ifdef CONFIG_NET_SWITCHDEV
854 __u8 offload_fwd_mark:1;
855 __u8 offload_l3_fwd_mark:1;
856 #endif
857 #ifdef CONFIG_NET_CLS_ACT
858 __u8 tc_skip_classify:1;
859 __u8 tc_at_ingress:1;
860 #endif
861 #ifdef CONFIG_NET_REDIRECT
862 __u8 redirected:1;
863 __u8 from_ingress:1;
864 #endif
865 #ifdef CONFIG_TLS_DEVICE
866 __u8 decrypted:1;
867 #endif
868
869 #ifdef CONFIG_NET_SCHED
870 __u16 tc_index; /* traffic control index */
871 #endif
872
873 union {
874 __wsum csum;
875 struct {
876 __u16 csum_start;
877 __u16 csum_offset;
878 };
879 };
880 __u32 priority;
881 int skb_iif;
882 __u32 hash;
883 __be16 vlan_proto;
884 __u16 vlan_tci;
885 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
886 union {
887 unsigned int napi_id;
888 unsigned int sender_cpu;
889 };
890 #endif
891 #ifdef CONFIG_NETWORK_SECMARK
892 __u32 secmark;
893 #endif
894
895 union {
896 __u32 mark;
897 __u32 reserved_tailroom;
898 };
899
900 union {
901 __be16 inner_protocol;
902 __u8 inner_ipproto;
903 };
904
905 __u16 inner_transport_header;
906 __u16 inner_network_header;
907 __u16 inner_mac_header;
908
909 __be16 protocol;
910 __u16 transport_header;
911 __u16 network_header;
912 __u16 mac_header;
913
914 #ifdef CONFIG_KCOV
915 u64 kcov_handle;
916 #endif
917
918 /* private: */
919 __u32 headers_end[0];
920 /* public: */
921
922 /* These elements must be at the end, see alloc_skb() for details. */
923 sk_buff_data_t tail;
924 sk_buff_data_t end;
925 unsigned char *head,
926 *data;
927 unsigned int truesize;
928 refcount_t users;
929
930 #ifdef CONFIG_SKB_EXTENSIONS
931 /* only useable after checking ->active_extensions != 0 */
932 struct skb_ext *extensions;
933 #endif
934 };
935
936 #ifdef __KERNEL__
937 /*
938 * Handling routines are only of interest to the kernel
939 */
940
941 #define SKB_ALLOC_FCLONE 0x01
942 #define SKB_ALLOC_RX 0x02
943 #define SKB_ALLOC_NAPI 0x04
944
945 /**
946 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
947 * @skb: buffer
948 */
skb_pfmemalloc(const struct sk_buff * skb)949 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
950 {
951 return unlikely(skb->pfmemalloc);
952 }
953
954 /*
955 * skb might have a dst pointer attached, refcounted or not.
956 * _skb_refdst low order bit is set if refcount was _not_ taken
957 */
958 #define SKB_DST_NOREF 1UL
959 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
960
961 /**
962 * skb_dst - returns skb dst_entry
963 * @skb: buffer
964 *
965 * Returns skb dst_entry, regardless of reference taken or not.
966 */
skb_dst(const struct sk_buff * skb)967 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
968 {
969 /* If refdst was not refcounted, check we still are in a
970 * rcu_read_lock section
971 */
972 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
973 !rcu_read_lock_held() &&
974 !rcu_read_lock_bh_held());
975 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
976 }
977
978 /**
979 * skb_dst_set - sets skb dst
980 * @skb: buffer
981 * @dst: dst entry
982 *
983 * Sets skb dst, assuming a reference was taken on dst and should
984 * be released by skb_dst_drop()
985 */
skb_dst_set(struct sk_buff * skb,struct dst_entry * dst)986 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
987 {
988 skb->_skb_refdst = (unsigned long)dst;
989 }
990
991 /**
992 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
993 * @skb: buffer
994 * @dst: dst entry
995 *
996 * Sets skb dst, assuming a reference was not taken on dst.
997 * If dst entry is cached, we do not take reference and dst_release
998 * will be avoided by refdst_drop. If dst entry is not cached, we take
999 * reference, so that last dst_release can destroy the dst immediately.
1000 */
skb_dst_set_noref(struct sk_buff * skb,struct dst_entry * dst)1001 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1002 {
1003 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1004 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1005 }
1006
1007 /**
1008 * skb_dst_is_noref - Test if skb dst isn't refcounted
1009 * @skb: buffer
1010 */
skb_dst_is_noref(const struct sk_buff * skb)1011 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1012 {
1013 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1014 }
1015
1016 /**
1017 * skb_rtable - Returns the skb &rtable
1018 * @skb: buffer
1019 */
skb_rtable(const struct sk_buff * skb)1020 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
1021 {
1022 return (struct rtable *)skb_dst(skb);
1023 }
1024
1025 /* For mangling skb->pkt_type from user space side from applications
1026 * such as nft, tc, etc, we only allow a conservative subset of
1027 * possible pkt_types to be set.
1028 */
skb_pkt_type_ok(u32 ptype)1029 static inline bool skb_pkt_type_ok(u32 ptype)
1030 {
1031 return ptype <= PACKET_OTHERHOST;
1032 }
1033
1034 /**
1035 * skb_napi_id - Returns the skb's NAPI id
1036 * @skb: buffer
1037 */
skb_napi_id(const struct sk_buff * skb)1038 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1039 {
1040 #ifdef CONFIG_NET_RX_BUSY_POLL
1041 return skb->napi_id;
1042 #else
1043 return 0;
1044 #endif
1045 }
1046
1047 /**
1048 * skb_unref - decrement the skb's reference count
1049 * @skb: buffer
1050 *
1051 * Returns true if we can free the skb.
1052 */
skb_unref(struct sk_buff * skb)1053 static inline bool skb_unref(struct sk_buff *skb)
1054 {
1055 if (unlikely(!skb))
1056 return false;
1057 if (likely(refcount_read(&skb->users) == 1))
1058 smp_rmb();
1059 else if (likely(!refcount_dec_and_test(&skb->users)))
1060 return false;
1061
1062 return true;
1063 }
1064
1065 void skb_release_head_state(struct sk_buff *skb);
1066 void kfree_skb(struct sk_buff *skb);
1067 void kfree_skb_list(struct sk_buff *segs);
1068 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1069 void skb_tx_error(struct sk_buff *skb);
1070
1071 #ifdef CONFIG_TRACEPOINTS
1072 void consume_skb(struct sk_buff *skb);
1073 #else
consume_skb(struct sk_buff * skb)1074 static inline void consume_skb(struct sk_buff *skb)
1075 {
1076 return kfree_skb(skb);
1077 }
1078 #endif
1079
1080 void __consume_stateless_skb(struct sk_buff *skb);
1081 void __kfree_skb(struct sk_buff *skb);
1082 extern struct kmem_cache *skbuff_head_cache;
1083
1084 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1085 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1086 bool *fragstolen, int *delta_truesize);
1087
1088 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1089 int node);
1090 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1091 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1092 struct sk_buff *build_skb_around(struct sk_buff *skb,
1093 void *data, unsigned int frag_size);
1094
1095 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1096
1097 /**
1098 * alloc_skb - allocate a network buffer
1099 * @size: size to allocate
1100 * @priority: allocation mask
1101 *
1102 * This function is a convenient wrapper around __alloc_skb().
1103 */
alloc_skb(unsigned int size,gfp_t priority)1104 static inline struct sk_buff *alloc_skb(unsigned int size,
1105 gfp_t priority)
1106 {
1107 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1108 }
1109
1110 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1111 unsigned long data_len,
1112 int max_page_order,
1113 int *errcode,
1114 gfp_t gfp_mask);
1115 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1116
1117 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1118 struct sk_buff_fclones {
1119 struct sk_buff skb1;
1120
1121 struct sk_buff skb2;
1122
1123 refcount_t fclone_ref;
1124 };
1125
1126 /**
1127 * skb_fclone_busy - check if fclone is busy
1128 * @sk: socket
1129 * @skb: buffer
1130 *
1131 * Returns true if skb is a fast clone, and its clone is not freed.
1132 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1133 * so we also check that this didnt happen.
1134 */
skb_fclone_busy(const struct sock * sk,const struct sk_buff * skb)1135 static inline bool skb_fclone_busy(const struct sock *sk,
1136 const struct sk_buff *skb)
1137 {
1138 const struct sk_buff_fclones *fclones;
1139
1140 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1141
1142 return skb->fclone == SKB_FCLONE_ORIG &&
1143 refcount_read(&fclones->fclone_ref) > 1 &&
1144 READ_ONCE(fclones->skb2.sk) == sk;
1145 }
1146
1147 /**
1148 * alloc_skb_fclone - allocate a network buffer from fclone cache
1149 * @size: size to allocate
1150 * @priority: allocation mask
1151 *
1152 * This function is a convenient wrapper around __alloc_skb().
1153 */
alloc_skb_fclone(unsigned int size,gfp_t priority)1154 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1155 gfp_t priority)
1156 {
1157 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1158 }
1159
1160 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1161 void skb_headers_offset_update(struct sk_buff *skb, int off);
1162 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1163 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1164 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1165 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1166 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1167 gfp_t gfp_mask, bool fclone);
__pskb_copy(struct sk_buff * skb,int headroom,gfp_t gfp_mask)1168 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1169 gfp_t gfp_mask)
1170 {
1171 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1172 }
1173
1174 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1175 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1176 unsigned int headroom);
1177 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1178 int newtailroom, gfp_t priority);
1179 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1180 int offset, int len);
1181 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1182 int offset, int len);
1183 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1184 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1185
1186 /**
1187 * skb_pad - zero pad the tail of an skb
1188 * @skb: buffer to pad
1189 * @pad: space to pad
1190 *
1191 * Ensure that a buffer is followed by a padding area that is zero
1192 * filled. Used by network drivers which may DMA or transfer data
1193 * beyond the buffer end onto the wire.
1194 *
1195 * May return error in out of memory cases. The skb is freed on error.
1196 */
skb_pad(struct sk_buff * skb,int pad)1197 static inline int skb_pad(struct sk_buff *skb, int pad)
1198 {
1199 return __skb_pad(skb, pad, true);
1200 }
1201 #define dev_kfree_skb(a) consume_skb(a)
1202
1203 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1204 int offset, size_t size);
1205
1206 struct skb_seq_state {
1207 __u32 lower_offset;
1208 __u32 upper_offset;
1209 __u32 frag_idx;
1210 __u32 stepped_offset;
1211 struct sk_buff *root_skb;
1212 struct sk_buff *cur_skb;
1213 __u8 *frag_data;
1214 __u32 frag_off;
1215 };
1216
1217 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1218 unsigned int to, struct skb_seq_state *st);
1219 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1220 struct skb_seq_state *st);
1221 void skb_abort_seq_read(struct skb_seq_state *st);
1222
1223 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1224 unsigned int to, struct ts_config *config);
1225
1226 /*
1227 * Packet hash types specify the type of hash in skb_set_hash.
1228 *
1229 * Hash types refer to the protocol layer addresses which are used to
1230 * construct a packet's hash. The hashes are used to differentiate or identify
1231 * flows of the protocol layer for the hash type. Hash types are either
1232 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1233 *
1234 * Properties of hashes:
1235 *
1236 * 1) Two packets in different flows have different hash values
1237 * 2) Two packets in the same flow should have the same hash value
1238 *
1239 * A hash at a higher layer is considered to be more specific. A driver should
1240 * set the most specific hash possible.
1241 *
1242 * A driver cannot indicate a more specific hash than the layer at which a hash
1243 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1244 *
1245 * A driver may indicate a hash level which is less specific than the
1246 * actual layer the hash was computed on. For instance, a hash computed
1247 * at L4 may be considered an L3 hash. This should only be done if the
1248 * driver can't unambiguously determine that the HW computed the hash at
1249 * the higher layer. Note that the "should" in the second property above
1250 * permits this.
1251 */
1252 enum pkt_hash_types {
1253 PKT_HASH_TYPE_NONE, /* Undefined type */
1254 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1255 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1256 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1257 };
1258
skb_clear_hash(struct sk_buff * skb)1259 static inline void skb_clear_hash(struct sk_buff *skb)
1260 {
1261 skb->hash = 0;
1262 skb->sw_hash = 0;
1263 skb->l4_hash = 0;
1264 }
1265
skb_clear_hash_if_not_l4(struct sk_buff * skb)1266 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1267 {
1268 if (!skb->l4_hash)
1269 skb_clear_hash(skb);
1270 }
1271
1272 static inline void
__skb_set_hash(struct sk_buff * skb,__u32 hash,bool is_sw,bool is_l4)1273 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1274 {
1275 skb->l4_hash = is_l4;
1276 skb->sw_hash = is_sw;
1277 skb->hash = hash;
1278 }
1279
1280 static inline void
skb_set_hash(struct sk_buff * skb,__u32 hash,enum pkt_hash_types type)1281 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1282 {
1283 /* Used by drivers to set hash from HW */
1284 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1285 }
1286
1287 static inline void
__skb_set_sw_hash(struct sk_buff * skb,__u32 hash,bool is_l4)1288 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1289 {
1290 __skb_set_hash(skb, hash, true, is_l4);
1291 }
1292
1293 void __skb_get_hash(struct sk_buff *skb);
1294 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1295 u32 skb_get_poff(const struct sk_buff *skb);
1296 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1297 const struct flow_keys_basic *keys, int hlen);
1298 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1299 const void *data, int hlen_proto);
1300
skb_flow_get_ports(const struct sk_buff * skb,int thoff,u8 ip_proto)1301 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1302 int thoff, u8 ip_proto)
1303 {
1304 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1305 }
1306
1307 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1308 const struct flow_dissector_key *key,
1309 unsigned int key_count);
1310
1311 struct bpf_flow_dissector;
1312 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1313 __be16 proto, int nhoff, int hlen, unsigned int flags);
1314
1315 bool __skb_flow_dissect(const struct net *net,
1316 const struct sk_buff *skb,
1317 struct flow_dissector *flow_dissector,
1318 void *target_container, const void *data,
1319 __be16 proto, int nhoff, int hlen, unsigned int flags);
1320
skb_flow_dissect(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,unsigned int flags)1321 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1322 struct flow_dissector *flow_dissector,
1323 void *target_container, unsigned int flags)
1324 {
1325 return __skb_flow_dissect(NULL, skb, flow_dissector,
1326 target_container, NULL, 0, 0, 0, flags);
1327 }
1328
skb_flow_dissect_flow_keys(const struct sk_buff * skb,struct flow_keys * flow,unsigned int flags)1329 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1330 struct flow_keys *flow,
1331 unsigned int flags)
1332 {
1333 memset(flow, 0, sizeof(*flow));
1334 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1335 flow, NULL, 0, 0, 0, flags);
1336 }
1337
1338 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)1339 skb_flow_dissect_flow_keys_basic(const struct net *net,
1340 const struct sk_buff *skb,
1341 struct flow_keys_basic *flow,
1342 const void *data, __be16 proto,
1343 int nhoff, int hlen, unsigned int flags)
1344 {
1345 memset(flow, 0, sizeof(*flow));
1346 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1347 data, proto, nhoff, hlen, flags);
1348 }
1349
1350 void skb_flow_dissect_meta(const struct sk_buff *skb,
1351 struct flow_dissector *flow_dissector,
1352 void *target_container);
1353
1354 /* Gets a skb connection tracking info, ctinfo map should be a
1355 * map of mapsize to translate enum ip_conntrack_info states
1356 * to user states.
1357 */
1358 void
1359 skb_flow_dissect_ct(const struct sk_buff *skb,
1360 struct flow_dissector *flow_dissector,
1361 void *target_container,
1362 u16 *ctinfo_map, size_t mapsize,
1363 bool post_ct);
1364 void
1365 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1366 struct flow_dissector *flow_dissector,
1367 void *target_container);
1368
1369 void skb_flow_dissect_hash(const struct sk_buff *skb,
1370 struct flow_dissector *flow_dissector,
1371 void *target_container);
1372
skb_get_hash(struct sk_buff * skb)1373 static inline __u32 skb_get_hash(struct sk_buff *skb)
1374 {
1375 if (!skb->l4_hash && !skb->sw_hash)
1376 __skb_get_hash(skb);
1377
1378 return skb->hash;
1379 }
1380
skb_get_hash_flowi6(struct sk_buff * skb,const struct flowi6 * fl6)1381 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1382 {
1383 if (!skb->l4_hash && !skb->sw_hash) {
1384 struct flow_keys keys;
1385 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1386
1387 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1388 }
1389
1390 return skb->hash;
1391 }
1392
1393 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1394 const siphash_key_t *perturb);
1395
skb_get_hash_raw(const struct sk_buff * skb)1396 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1397 {
1398 return skb->hash;
1399 }
1400
skb_copy_hash(struct sk_buff * to,const struct sk_buff * from)1401 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1402 {
1403 to->hash = from->hash;
1404 to->sw_hash = from->sw_hash;
1405 to->l4_hash = from->l4_hash;
1406 };
1407
skb_copy_decrypted(struct sk_buff * to,const struct sk_buff * from)1408 static inline void skb_copy_decrypted(struct sk_buff *to,
1409 const struct sk_buff *from)
1410 {
1411 #ifdef CONFIG_TLS_DEVICE
1412 to->decrypted = from->decrypted;
1413 #endif
1414 }
1415
1416 #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_end_pointer(const struct sk_buff * skb)1417 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1418 {
1419 return skb->head + skb->end;
1420 }
1421
skb_end_offset(const struct sk_buff * skb)1422 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1423 {
1424 return skb->end;
1425 }
1426 #else
skb_end_pointer(const struct sk_buff * skb)1427 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1428 {
1429 return skb->end;
1430 }
1431
skb_end_offset(const struct sk_buff * skb)1432 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1433 {
1434 return skb->end - skb->head;
1435 }
1436 #endif
1437
1438 /* Internal */
1439 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1440
skb_hwtstamps(struct sk_buff * skb)1441 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1442 {
1443 return &skb_shinfo(skb)->hwtstamps;
1444 }
1445
skb_zcopy(struct sk_buff * skb)1446 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1447 {
1448 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1449
1450 return is_zcopy ? skb_uarg(skb) : NULL;
1451 }
1452
net_zcopy_get(struct ubuf_info * uarg)1453 static inline void net_zcopy_get(struct ubuf_info *uarg)
1454 {
1455 refcount_inc(&uarg->refcnt);
1456 }
1457
skb_zcopy_init(struct sk_buff * skb,struct ubuf_info * uarg)1458 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1459 {
1460 skb_shinfo(skb)->destructor_arg = uarg;
1461 skb_shinfo(skb)->flags |= uarg->flags;
1462 }
1463
skb_zcopy_set(struct sk_buff * skb,struct ubuf_info * uarg,bool * have_ref)1464 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1465 bool *have_ref)
1466 {
1467 if (skb && uarg && !skb_zcopy(skb)) {
1468 if (unlikely(have_ref && *have_ref))
1469 *have_ref = false;
1470 else
1471 net_zcopy_get(uarg);
1472 skb_zcopy_init(skb, uarg);
1473 }
1474 }
1475
skb_zcopy_set_nouarg(struct sk_buff * skb,void * val)1476 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1477 {
1478 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1479 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1480 }
1481
skb_zcopy_is_nouarg(struct sk_buff * skb)1482 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1483 {
1484 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1485 }
1486
skb_zcopy_get_nouarg(struct sk_buff * skb)1487 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1488 {
1489 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1490 }
1491
net_zcopy_put(struct ubuf_info * uarg)1492 static inline void net_zcopy_put(struct ubuf_info *uarg)
1493 {
1494 if (uarg)
1495 uarg->callback(NULL, uarg, true);
1496 }
1497
net_zcopy_put_abort(struct ubuf_info * uarg,bool have_uref)1498 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1499 {
1500 if (uarg) {
1501 if (uarg->callback == msg_zerocopy_callback)
1502 msg_zerocopy_put_abort(uarg, have_uref);
1503 else if (have_uref)
1504 net_zcopy_put(uarg);
1505 }
1506 }
1507
1508 /* Release a reference on a zerocopy structure */
skb_zcopy_clear(struct sk_buff * skb,bool zerocopy_success)1509 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1510 {
1511 struct ubuf_info *uarg = skb_zcopy(skb);
1512
1513 if (uarg) {
1514 if (!skb_zcopy_is_nouarg(skb))
1515 uarg->callback(skb, uarg, zerocopy_success);
1516
1517 skb_shinfo(skb)->flags &= ~SKBFL_ZEROCOPY_FRAG;
1518 }
1519 }
1520
skb_mark_not_on_list(struct sk_buff * skb)1521 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1522 {
1523 skb->next = NULL;
1524 }
1525
1526 /* Iterate through singly-linked GSO fragments of an skb. */
1527 #define skb_list_walk_safe(first, skb, next_skb) \
1528 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1529 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1530
skb_list_del_init(struct sk_buff * skb)1531 static inline void skb_list_del_init(struct sk_buff *skb)
1532 {
1533 __list_del_entry(&skb->list);
1534 skb_mark_not_on_list(skb);
1535 }
1536
1537 /**
1538 * skb_queue_empty - check if a queue is empty
1539 * @list: queue head
1540 *
1541 * Returns true if the queue is empty, false otherwise.
1542 */
skb_queue_empty(const struct sk_buff_head * list)1543 static inline int skb_queue_empty(const struct sk_buff_head *list)
1544 {
1545 return list->next == (const struct sk_buff *) list;
1546 }
1547
1548 /**
1549 * skb_queue_empty_lockless - check if a queue is empty
1550 * @list: queue head
1551 *
1552 * Returns true if the queue is empty, false otherwise.
1553 * This variant can be used in lockless contexts.
1554 */
skb_queue_empty_lockless(const struct sk_buff_head * list)1555 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1556 {
1557 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1558 }
1559
1560
1561 /**
1562 * skb_queue_is_last - check if skb is the last entry in the queue
1563 * @list: queue head
1564 * @skb: buffer
1565 *
1566 * Returns true if @skb is the last buffer on the list.
1567 */
skb_queue_is_last(const struct sk_buff_head * list,const struct sk_buff * skb)1568 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1569 const struct sk_buff *skb)
1570 {
1571 return skb->next == (const struct sk_buff *) list;
1572 }
1573
1574 /**
1575 * skb_queue_is_first - check if skb is the first entry in the queue
1576 * @list: queue head
1577 * @skb: buffer
1578 *
1579 * Returns true if @skb is the first buffer on the list.
1580 */
skb_queue_is_first(const struct sk_buff_head * list,const struct sk_buff * skb)1581 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1582 const struct sk_buff *skb)
1583 {
1584 return skb->prev == (const struct sk_buff *) list;
1585 }
1586
1587 /**
1588 * skb_queue_next - return the next packet in the queue
1589 * @list: queue head
1590 * @skb: current buffer
1591 *
1592 * Return the next packet in @list after @skb. It is only valid to
1593 * call this if skb_queue_is_last() evaluates to false.
1594 */
skb_queue_next(const struct sk_buff_head * list,const struct sk_buff * skb)1595 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1596 const struct sk_buff *skb)
1597 {
1598 /* This BUG_ON may seem severe, but if we just return then we
1599 * are going to dereference garbage.
1600 */
1601 BUG_ON(skb_queue_is_last(list, skb));
1602 return skb->next;
1603 }
1604
1605 /**
1606 * skb_queue_prev - return the prev packet in the queue
1607 * @list: queue head
1608 * @skb: current buffer
1609 *
1610 * Return the prev packet in @list before @skb. It is only valid to
1611 * call this if skb_queue_is_first() evaluates to false.
1612 */
skb_queue_prev(const struct sk_buff_head * list,const struct sk_buff * skb)1613 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1614 const struct sk_buff *skb)
1615 {
1616 /* This BUG_ON may seem severe, but if we just return then we
1617 * are going to dereference garbage.
1618 */
1619 BUG_ON(skb_queue_is_first(list, skb));
1620 return skb->prev;
1621 }
1622
1623 /**
1624 * skb_get - reference buffer
1625 * @skb: buffer to reference
1626 *
1627 * Makes another reference to a socket buffer and returns a pointer
1628 * to the buffer.
1629 */
skb_get(struct sk_buff * skb)1630 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1631 {
1632 refcount_inc(&skb->users);
1633 return skb;
1634 }
1635
1636 /*
1637 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1638 */
1639
1640 /**
1641 * skb_cloned - is the buffer a clone
1642 * @skb: buffer to check
1643 *
1644 * Returns true if the buffer was generated with skb_clone() and is
1645 * one of multiple shared copies of the buffer. Cloned buffers are
1646 * shared data so must not be written to under normal circumstances.
1647 */
skb_cloned(const struct sk_buff * skb)1648 static inline int skb_cloned(const struct sk_buff *skb)
1649 {
1650 return skb->cloned &&
1651 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1652 }
1653
skb_unclone(struct sk_buff * skb,gfp_t pri)1654 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1655 {
1656 might_sleep_if(gfpflags_allow_blocking(pri));
1657
1658 if (skb_cloned(skb))
1659 return pskb_expand_head(skb, 0, 0, pri);
1660
1661 return 0;
1662 }
1663
1664 /**
1665 * skb_header_cloned - is the header a clone
1666 * @skb: buffer to check
1667 *
1668 * Returns true if modifying the header part of the buffer requires
1669 * the data to be copied.
1670 */
skb_header_cloned(const struct sk_buff * skb)1671 static inline int skb_header_cloned(const struct sk_buff *skb)
1672 {
1673 int dataref;
1674
1675 if (!skb->cloned)
1676 return 0;
1677
1678 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1679 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1680 return dataref != 1;
1681 }
1682
skb_header_unclone(struct sk_buff * skb,gfp_t pri)1683 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1684 {
1685 might_sleep_if(gfpflags_allow_blocking(pri));
1686
1687 if (skb_header_cloned(skb))
1688 return pskb_expand_head(skb, 0, 0, pri);
1689
1690 return 0;
1691 }
1692
1693 /**
1694 * __skb_header_release - release reference to header
1695 * @skb: buffer to operate on
1696 */
__skb_header_release(struct sk_buff * skb)1697 static inline void __skb_header_release(struct sk_buff *skb)
1698 {
1699 skb->nohdr = 1;
1700 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1701 }
1702
1703
1704 /**
1705 * skb_shared - is the buffer shared
1706 * @skb: buffer to check
1707 *
1708 * Returns true if more than one person has a reference to this
1709 * buffer.
1710 */
skb_shared(const struct sk_buff * skb)1711 static inline int skb_shared(const struct sk_buff *skb)
1712 {
1713 return refcount_read(&skb->users) != 1;
1714 }
1715
1716 /**
1717 * skb_share_check - check if buffer is shared and if so clone it
1718 * @skb: buffer to check
1719 * @pri: priority for memory allocation
1720 *
1721 * If the buffer is shared the buffer is cloned and the old copy
1722 * drops a reference. A new clone with a single reference is returned.
1723 * If the buffer is not shared the original buffer is returned. When
1724 * being called from interrupt status or with spinlocks held pri must
1725 * be GFP_ATOMIC.
1726 *
1727 * NULL is returned on a memory allocation failure.
1728 */
skb_share_check(struct sk_buff * skb,gfp_t pri)1729 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1730 {
1731 might_sleep_if(gfpflags_allow_blocking(pri));
1732 if (skb_shared(skb)) {
1733 struct sk_buff *nskb = skb_clone(skb, pri);
1734
1735 if (likely(nskb))
1736 consume_skb(skb);
1737 else
1738 kfree_skb(skb);
1739 skb = nskb;
1740 }
1741 return skb;
1742 }
1743
1744 /*
1745 * Copy shared buffers into a new sk_buff. We effectively do COW on
1746 * packets to handle cases where we have a local reader and forward
1747 * and a couple of other messy ones. The normal one is tcpdumping
1748 * a packet thats being forwarded.
1749 */
1750
1751 /**
1752 * skb_unshare - make a copy of a shared buffer
1753 * @skb: buffer to check
1754 * @pri: priority for memory allocation
1755 *
1756 * If the socket buffer is a clone then this function creates a new
1757 * copy of the data, drops a reference count on the old copy and returns
1758 * the new copy with the reference count at 1. If the buffer is not a clone
1759 * the original buffer is returned. When called with a spinlock held or
1760 * from interrupt state @pri must be %GFP_ATOMIC
1761 *
1762 * %NULL is returned on a memory allocation failure.
1763 */
skb_unshare(struct sk_buff * skb,gfp_t pri)1764 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1765 gfp_t pri)
1766 {
1767 might_sleep_if(gfpflags_allow_blocking(pri));
1768 if (skb_cloned(skb)) {
1769 struct sk_buff *nskb = skb_copy(skb, pri);
1770
1771 /* Free our shared copy */
1772 if (likely(nskb))
1773 consume_skb(skb);
1774 else
1775 kfree_skb(skb);
1776 skb = nskb;
1777 }
1778 return skb;
1779 }
1780
1781 /**
1782 * skb_peek - peek at the head of an &sk_buff_head
1783 * @list_: list to peek at
1784 *
1785 * Peek an &sk_buff. Unlike most other operations you _MUST_
1786 * be careful with this one. A peek leaves the buffer on the
1787 * list and someone else may run off with it. You must hold
1788 * the appropriate locks or have a private queue to do this.
1789 *
1790 * Returns %NULL for an empty list or a pointer to the head element.
1791 * The reference count is not incremented and the reference is therefore
1792 * volatile. Use with caution.
1793 */
skb_peek(const struct sk_buff_head * list_)1794 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1795 {
1796 struct sk_buff *skb = list_->next;
1797
1798 if (skb == (struct sk_buff *)list_)
1799 skb = NULL;
1800 return skb;
1801 }
1802
1803 /**
1804 * __skb_peek - peek at the head of a non-empty &sk_buff_head
1805 * @list_: list to peek at
1806 *
1807 * Like skb_peek(), but the caller knows that the list is not empty.
1808 */
__skb_peek(const struct sk_buff_head * list_)1809 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
1810 {
1811 return list_->next;
1812 }
1813
1814 /**
1815 * skb_peek_next - peek skb following the given one from a queue
1816 * @skb: skb to start from
1817 * @list_: list to peek at
1818 *
1819 * Returns %NULL when the end of the list is met or a pointer to the
1820 * next element. The reference count is not incremented and the
1821 * reference is therefore volatile. Use with caution.
1822 */
skb_peek_next(struct sk_buff * skb,const struct sk_buff_head * list_)1823 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1824 const struct sk_buff_head *list_)
1825 {
1826 struct sk_buff *next = skb->next;
1827
1828 if (next == (struct sk_buff *)list_)
1829 next = NULL;
1830 return next;
1831 }
1832
1833 /**
1834 * skb_peek_tail - peek at the tail of an &sk_buff_head
1835 * @list_: list to peek at
1836 *
1837 * Peek an &sk_buff. Unlike most other operations you _MUST_
1838 * be careful with this one. A peek leaves the buffer on the
1839 * list and someone else may run off with it. You must hold
1840 * the appropriate locks or have a private queue to do this.
1841 *
1842 * Returns %NULL for an empty list or a pointer to the tail element.
1843 * The reference count is not incremented and the reference is therefore
1844 * volatile. Use with caution.
1845 */
skb_peek_tail(const struct sk_buff_head * list_)1846 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1847 {
1848 struct sk_buff *skb = READ_ONCE(list_->prev);
1849
1850 if (skb == (struct sk_buff *)list_)
1851 skb = NULL;
1852 return skb;
1853
1854 }
1855
1856 /**
1857 * skb_queue_len - get queue length
1858 * @list_: list to measure
1859 *
1860 * Return the length of an &sk_buff queue.
1861 */
skb_queue_len(const struct sk_buff_head * list_)1862 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1863 {
1864 return list_->qlen;
1865 }
1866
1867 /**
1868 * skb_queue_len_lockless - get queue length
1869 * @list_: list to measure
1870 *
1871 * Return the length of an &sk_buff queue.
1872 * This variant can be used in lockless contexts.
1873 */
skb_queue_len_lockless(const struct sk_buff_head * list_)1874 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
1875 {
1876 return READ_ONCE(list_->qlen);
1877 }
1878
1879 /**
1880 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1881 * @list: queue to initialize
1882 *
1883 * This initializes only the list and queue length aspects of
1884 * an sk_buff_head object. This allows to initialize the list
1885 * aspects of an sk_buff_head without reinitializing things like
1886 * the spinlock. It can also be used for on-stack sk_buff_head
1887 * objects where the spinlock is known to not be used.
1888 */
__skb_queue_head_init(struct sk_buff_head * list)1889 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1890 {
1891 list->prev = list->next = (struct sk_buff *)list;
1892 list->qlen = 0;
1893 }
1894
1895 /*
1896 * This function creates a split out lock class for each invocation;
1897 * this is needed for now since a whole lot of users of the skb-queue
1898 * infrastructure in drivers have different locking usage (in hardirq)
1899 * than the networking core (in softirq only). In the long run either the
1900 * network layer or drivers should need annotation to consolidate the
1901 * main types of usage into 3 classes.
1902 */
skb_queue_head_init(struct sk_buff_head * list)1903 static inline void skb_queue_head_init(struct sk_buff_head *list)
1904 {
1905 spin_lock_init(&list->lock);
1906 __skb_queue_head_init(list);
1907 }
1908
skb_queue_head_init_class(struct sk_buff_head * list,struct lock_class_key * class)1909 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1910 struct lock_class_key *class)
1911 {
1912 skb_queue_head_init(list);
1913 lockdep_set_class(&list->lock, class);
1914 }
1915
1916 /*
1917 * Insert an sk_buff on a list.
1918 *
1919 * The "__skb_xxxx()" functions are the non-atomic ones that
1920 * can only be called with interrupts disabled.
1921 */
__skb_insert(struct sk_buff * newsk,struct sk_buff * prev,struct sk_buff * next,struct sk_buff_head * list)1922 static inline void __skb_insert(struct sk_buff *newsk,
1923 struct sk_buff *prev, struct sk_buff *next,
1924 struct sk_buff_head *list)
1925 {
1926 /* See skb_queue_empty_lockless() and skb_peek_tail()
1927 * for the opposite READ_ONCE()
1928 */
1929 WRITE_ONCE(newsk->next, next);
1930 WRITE_ONCE(newsk->prev, prev);
1931 WRITE_ONCE(next->prev, newsk);
1932 WRITE_ONCE(prev->next, newsk);
1933 list->qlen++;
1934 }
1935
__skb_queue_splice(const struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * next)1936 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1937 struct sk_buff *prev,
1938 struct sk_buff *next)
1939 {
1940 struct sk_buff *first = list->next;
1941 struct sk_buff *last = list->prev;
1942
1943 WRITE_ONCE(first->prev, prev);
1944 WRITE_ONCE(prev->next, first);
1945
1946 WRITE_ONCE(last->next, next);
1947 WRITE_ONCE(next->prev, last);
1948 }
1949
1950 /**
1951 * skb_queue_splice - join two skb lists, this is designed for stacks
1952 * @list: the new list to add
1953 * @head: the place to add it in the first list
1954 */
skb_queue_splice(const struct sk_buff_head * list,struct sk_buff_head * head)1955 static inline void skb_queue_splice(const struct sk_buff_head *list,
1956 struct sk_buff_head *head)
1957 {
1958 if (!skb_queue_empty(list)) {
1959 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1960 head->qlen += list->qlen;
1961 }
1962 }
1963
1964 /**
1965 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1966 * @list: the new list to add
1967 * @head: the place to add it in the first list
1968 *
1969 * The list at @list is reinitialised
1970 */
skb_queue_splice_init(struct sk_buff_head * list,struct sk_buff_head * head)1971 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1972 struct sk_buff_head *head)
1973 {
1974 if (!skb_queue_empty(list)) {
1975 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1976 head->qlen += list->qlen;
1977 __skb_queue_head_init(list);
1978 }
1979 }
1980
1981 /**
1982 * skb_queue_splice_tail - join two skb lists, each list being a queue
1983 * @list: the new list to add
1984 * @head: the place to add it in the first list
1985 */
skb_queue_splice_tail(const struct sk_buff_head * list,struct sk_buff_head * head)1986 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1987 struct sk_buff_head *head)
1988 {
1989 if (!skb_queue_empty(list)) {
1990 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1991 head->qlen += list->qlen;
1992 }
1993 }
1994
1995 /**
1996 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1997 * @list: the new list to add
1998 * @head: the place to add it in the first list
1999 *
2000 * Each of the lists is a queue.
2001 * The list at @list is reinitialised
2002 */
skb_queue_splice_tail_init(struct sk_buff_head * list,struct sk_buff_head * head)2003 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2004 struct sk_buff_head *head)
2005 {
2006 if (!skb_queue_empty(list)) {
2007 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2008 head->qlen += list->qlen;
2009 __skb_queue_head_init(list);
2010 }
2011 }
2012
2013 /**
2014 * __skb_queue_after - queue a buffer at the list head
2015 * @list: list to use
2016 * @prev: place after this buffer
2017 * @newsk: buffer to queue
2018 *
2019 * Queue a buffer int the middle of a list. This function takes no locks
2020 * and you must therefore hold required locks before calling it.
2021 *
2022 * A buffer cannot be placed on two lists at the same time.
2023 */
__skb_queue_after(struct sk_buff_head * list,struct sk_buff * prev,struct sk_buff * newsk)2024 static inline void __skb_queue_after(struct sk_buff_head *list,
2025 struct sk_buff *prev,
2026 struct sk_buff *newsk)
2027 {
2028 __skb_insert(newsk, prev, prev->next, list);
2029 }
2030
2031 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2032 struct sk_buff_head *list);
2033
__skb_queue_before(struct sk_buff_head * list,struct sk_buff * next,struct sk_buff * newsk)2034 static inline void __skb_queue_before(struct sk_buff_head *list,
2035 struct sk_buff *next,
2036 struct sk_buff *newsk)
2037 {
2038 __skb_insert(newsk, next->prev, next, list);
2039 }
2040
2041 /**
2042 * __skb_queue_head - queue a buffer at the list head
2043 * @list: list to use
2044 * @newsk: buffer to queue
2045 *
2046 * Queue a buffer at the start of a list. This function takes no locks
2047 * and you must therefore hold required locks before calling it.
2048 *
2049 * A buffer cannot be placed on two lists at the same time.
2050 */
__skb_queue_head(struct sk_buff_head * list,struct sk_buff * newsk)2051 static inline void __skb_queue_head(struct sk_buff_head *list,
2052 struct sk_buff *newsk)
2053 {
2054 __skb_queue_after(list, (struct sk_buff *)list, newsk);
2055 }
2056 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2057
2058 /**
2059 * __skb_queue_tail - queue a buffer at the list tail
2060 * @list: list to use
2061 * @newsk: buffer to queue
2062 *
2063 * Queue a buffer at the end of a list. This function takes no locks
2064 * and you must therefore hold required locks before calling it.
2065 *
2066 * A buffer cannot be placed on two lists at the same time.
2067 */
__skb_queue_tail(struct sk_buff_head * list,struct sk_buff * newsk)2068 static inline void __skb_queue_tail(struct sk_buff_head *list,
2069 struct sk_buff *newsk)
2070 {
2071 __skb_queue_before(list, (struct sk_buff *)list, newsk);
2072 }
2073 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2074
2075 /*
2076 * remove sk_buff from list. _Must_ be called atomically, and with
2077 * the list known..
2078 */
2079 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
__skb_unlink(struct sk_buff * skb,struct sk_buff_head * list)2080 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2081 {
2082 struct sk_buff *next, *prev;
2083
2084 WRITE_ONCE(list->qlen, list->qlen - 1);
2085 next = skb->next;
2086 prev = skb->prev;
2087 skb->next = skb->prev = NULL;
2088 WRITE_ONCE(next->prev, prev);
2089 WRITE_ONCE(prev->next, next);
2090 }
2091
2092 /**
2093 * __skb_dequeue - remove from the head of the queue
2094 * @list: list to dequeue from
2095 *
2096 * Remove the head of the list. This function does not take any locks
2097 * so must be used with appropriate locks held only. The head item is
2098 * returned or %NULL if the list is empty.
2099 */
__skb_dequeue(struct sk_buff_head * list)2100 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2101 {
2102 struct sk_buff *skb = skb_peek(list);
2103 if (skb)
2104 __skb_unlink(skb, list);
2105 return skb;
2106 }
2107 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2108
2109 /**
2110 * __skb_dequeue_tail - remove from the tail of the queue
2111 * @list: list to dequeue from
2112 *
2113 * Remove the tail of the list. This function does not take any locks
2114 * so must be used with appropriate locks held only. The tail item is
2115 * returned or %NULL if the list is empty.
2116 */
__skb_dequeue_tail(struct sk_buff_head * list)2117 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2118 {
2119 struct sk_buff *skb = skb_peek_tail(list);
2120 if (skb)
2121 __skb_unlink(skb, list);
2122 return skb;
2123 }
2124 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2125
2126
skb_is_nonlinear(const struct sk_buff * skb)2127 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2128 {
2129 return skb->data_len;
2130 }
2131
skb_headlen(const struct sk_buff * skb)2132 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2133 {
2134 return skb->len - skb->data_len;
2135 }
2136
__skb_pagelen(const struct sk_buff * skb)2137 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2138 {
2139 unsigned int i, len = 0;
2140
2141 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2142 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2143 return len;
2144 }
2145
skb_pagelen(const struct sk_buff * skb)2146 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2147 {
2148 return skb_headlen(skb) + __skb_pagelen(skb);
2149 }
2150
2151 /**
2152 * __skb_fill_page_desc - initialise a paged fragment in an skb
2153 * @skb: buffer containing fragment to be initialised
2154 * @i: paged fragment index to initialise
2155 * @page: the page to use for this fragment
2156 * @off: the offset to the data with @page
2157 * @size: the length of the data
2158 *
2159 * Initialises the @i'th fragment of @skb to point to &size bytes at
2160 * offset @off within @page.
2161 *
2162 * Does not take any additional reference on the fragment.
2163 */
__skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2164 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2165 struct page *page, int off, int size)
2166 {
2167 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2168
2169 /*
2170 * Propagate page pfmemalloc to the skb if we can. The problem is
2171 * that not all callers have unique ownership of the page but rely
2172 * on page_is_pfmemalloc doing the right thing(tm).
2173 */
2174 frag->bv_page = page;
2175 frag->bv_offset = off;
2176 skb_frag_size_set(frag, size);
2177
2178 page = compound_head(page);
2179 if (page_is_pfmemalloc(page))
2180 skb->pfmemalloc = true;
2181 }
2182
2183 /**
2184 * skb_fill_page_desc - initialise a paged fragment in an skb
2185 * @skb: buffer containing fragment to be initialised
2186 * @i: paged fragment index to initialise
2187 * @page: the page to use for this fragment
2188 * @off: the offset to the data with @page
2189 * @size: the length of the data
2190 *
2191 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2192 * @skb to point to @size bytes at offset @off within @page. In
2193 * addition updates @skb such that @i is the last fragment.
2194 *
2195 * Does not take any additional reference on the fragment.
2196 */
skb_fill_page_desc(struct sk_buff * skb,int i,struct page * page,int off,int size)2197 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2198 struct page *page, int off, int size)
2199 {
2200 __skb_fill_page_desc(skb, i, page, off, size);
2201 skb_shinfo(skb)->nr_frags = i + 1;
2202 }
2203
2204 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
2205 int size, unsigned int truesize);
2206
2207 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2208 unsigned int truesize);
2209
2210 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2211
2212 #ifdef NET_SKBUFF_DATA_USES_OFFSET
skb_tail_pointer(const struct sk_buff * skb)2213 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2214 {
2215 return skb->head + skb->tail;
2216 }
2217
skb_reset_tail_pointer(struct sk_buff * skb)2218 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2219 {
2220 skb->tail = skb->data - skb->head;
2221 }
2222
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2223 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2224 {
2225 skb_reset_tail_pointer(skb);
2226 skb->tail += offset;
2227 }
2228
2229 #else /* NET_SKBUFF_DATA_USES_OFFSET */
skb_tail_pointer(const struct sk_buff * skb)2230 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2231 {
2232 return skb->tail;
2233 }
2234
skb_reset_tail_pointer(struct sk_buff * skb)2235 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2236 {
2237 skb->tail = skb->data;
2238 }
2239
skb_set_tail_pointer(struct sk_buff * skb,const int offset)2240 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2241 {
2242 skb->tail = skb->data + offset;
2243 }
2244
2245 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2246
2247 /*
2248 * Add data to an sk_buff
2249 */
2250 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2251 void *skb_put(struct sk_buff *skb, unsigned int len);
__skb_put(struct sk_buff * skb,unsigned int len)2252 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2253 {
2254 void *tmp = skb_tail_pointer(skb);
2255 SKB_LINEAR_ASSERT(skb);
2256 skb->tail += len;
2257 skb->len += len;
2258 return tmp;
2259 }
2260
__skb_put_zero(struct sk_buff * skb,unsigned int len)2261 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2262 {
2263 void *tmp = __skb_put(skb, len);
2264
2265 memset(tmp, 0, len);
2266 return tmp;
2267 }
2268
__skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2269 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2270 unsigned int len)
2271 {
2272 void *tmp = __skb_put(skb, len);
2273
2274 memcpy(tmp, data, len);
2275 return tmp;
2276 }
2277
__skb_put_u8(struct sk_buff * skb,u8 val)2278 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2279 {
2280 *(u8 *)__skb_put(skb, 1) = val;
2281 }
2282
skb_put_zero(struct sk_buff * skb,unsigned int len)2283 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2284 {
2285 void *tmp = skb_put(skb, len);
2286
2287 memset(tmp, 0, len);
2288
2289 return tmp;
2290 }
2291
skb_put_data(struct sk_buff * skb,const void * data,unsigned int len)2292 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2293 unsigned int len)
2294 {
2295 void *tmp = skb_put(skb, len);
2296
2297 memcpy(tmp, data, len);
2298
2299 return tmp;
2300 }
2301
skb_put_u8(struct sk_buff * skb,u8 val)2302 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2303 {
2304 *(u8 *)skb_put(skb, 1) = val;
2305 }
2306
2307 void *skb_push(struct sk_buff *skb, unsigned int len);
__skb_push(struct sk_buff * skb,unsigned int len)2308 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2309 {
2310 skb->data -= len;
2311 skb->len += len;
2312 return skb->data;
2313 }
2314
2315 void *skb_pull(struct sk_buff *skb, unsigned int len);
__skb_pull(struct sk_buff * skb,unsigned int len)2316 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2317 {
2318 skb->len -= len;
2319 BUG_ON(skb->len < skb->data_len);
2320 return skb->data += len;
2321 }
2322
skb_pull_inline(struct sk_buff * skb,unsigned int len)2323 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2324 {
2325 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2326 }
2327
2328 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2329
__pskb_pull(struct sk_buff * skb,unsigned int len)2330 static inline void *__pskb_pull(struct sk_buff *skb, unsigned int len)
2331 {
2332 if (len > skb_headlen(skb) &&
2333 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
2334 return NULL;
2335 skb->len -= len;
2336 return skb->data += len;
2337 }
2338
pskb_pull(struct sk_buff * skb,unsigned int len)2339 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2340 {
2341 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
2342 }
2343
pskb_may_pull(struct sk_buff * skb,unsigned int len)2344 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2345 {
2346 if (likely(len <= skb_headlen(skb)))
2347 return true;
2348 if (unlikely(len > skb->len))
2349 return false;
2350 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
2351 }
2352
2353 void skb_condense(struct sk_buff *skb);
2354
2355 /**
2356 * skb_headroom - bytes at buffer head
2357 * @skb: buffer to check
2358 *
2359 * Return the number of bytes of free space at the head of an &sk_buff.
2360 */
skb_headroom(const struct sk_buff * skb)2361 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2362 {
2363 return skb->data - skb->head;
2364 }
2365
2366 /**
2367 * skb_tailroom - bytes at buffer end
2368 * @skb: buffer to check
2369 *
2370 * Return the number of bytes of free space at the tail of an sk_buff
2371 */
skb_tailroom(const struct sk_buff * skb)2372 static inline int skb_tailroom(const struct sk_buff *skb)
2373 {
2374 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2375 }
2376
2377 /**
2378 * skb_availroom - bytes at buffer end
2379 * @skb: buffer to check
2380 *
2381 * Return the number of bytes of free space at the tail of an sk_buff
2382 * allocated by sk_stream_alloc()
2383 */
skb_availroom(const struct sk_buff * skb)2384 static inline int skb_availroom(const struct sk_buff *skb)
2385 {
2386 if (skb_is_nonlinear(skb))
2387 return 0;
2388
2389 return skb->end - skb->tail - skb->reserved_tailroom;
2390 }
2391
2392 /**
2393 * skb_reserve - adjust headroom
2394 * @skb: buffer to alter
2395 * @len: bytes to move
2396 *
2397 * Increase the headroom of an empty &sk_buff by reducing the tail
2398 * room. This is only allowed for an empty buffer.
2399 */
skb_reserve(struct sk_buff * skb,int len)2400 static inline void skb_reserve(struct sk_buff *skb, int len)
2401 {
2402 skb->data += len;
2403 skb->tail += len;
2404 }
2405
2406 /**
2407 * skb_tailroom_reserve - adjust reserved_tailroom
2408 * @skb: buffer to alter
2409 * @mtu: maximum amount of headlen permitted
2410 * @needed_tailroom: minimum amount of reserved_tailroom
2411 *
2412 * Set reserved_tailroom so that headlen can be as large as possible but
2413 * not larger than mtu and tailroom cannot be smaller than
2414 * needed_tailroom.
2415 * The required headroom should already have been reserved before using
2416 * this function.
2417 */
skb_tailroom_reserve(struct sk_buff * skb,unsigned int mtu,unsigned int needed_tailroom)2418 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2419 unsigned int needed_tailroom)
2420 {
2421 SKB_LINEAR_ASSERT(skb);
2422 if (mtu < skb_tailroom(skb) - needed_tailroom)
2423 /* use at most mtu */
2424 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2425 else
2426 /* use up to all available space */
2427 skb->reserved_tailroom = needed_tailroom;
2428 }
2429
2430 #define ENCAP_TYPE_ETHER 0
2431 #define ENCAP_TYPE_IPPROTO 1
2432
skb_set_inner_protocol(struct sk_buff * skb,__be16 protocol)2433 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2434 __be16 protocol)
2435 {
2436 skb->inner_protocol = protocol;
2437 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2438 }
2439
skb_set_inner_ipproto(struct sk_buff * skb,__u8 ipproto)2440 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2441 __u8 ipproto)
2442 {
2443 skb->inner_ipproto = ipproto;
2444 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2445 }
2446
skb_reset_inner_headers(struct sk_buff * skb)2447 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2448 {
2449 skb->inner_mac_header = skb->mac_header;
2450 skb->inner_network_header = skb->network_header;
2451 skb->inner_transport_header = skb->transport_header;
2452 }
2453
skb_reset_mac_len(struct sk_buff * skb)2454 static inline void skb_reset_mac_len(struct sk_buff *skb)
2455 {
2456 skb->mac_len = skb->network_header - skb->mac_header;
2457 }
2458
skb_inner_transport_header(const struct sk_buff * skb)2459 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2460 *skb)
2461 {
2462 return skb->head + skb->inner_transport_header;
2463 }
2464
skb_inner_transport_offset(const struct sk_buff * skb)2465 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2466 {
2467 return skb_inner_transport_header(skb) - skb->data;
2468 }
2469
skb_reset_inner_transport_header(struct sk_buff * skb)2470 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2471 {
2472 skb->inner_transport_header = skb->data - skb->head;
2473 }
2474
skb_set_inner_transport_header(struct sk_buff * skb,const int offset)2475 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2476 const int offset)
2477 {
2478 skb_reset_inner_transport_header(skb);
2479 skb->inner_transport_header += offset;
2480 }
2481
skb_inner_network_header(const struct sk_buff * skb)2482 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2483 {
2484 return skb->head + skb->inner_network_header;
2485 }
2486
skb_reset_inner_network_header(struct sk_buff * skb)2487 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2488 {
2489 skb->inner_network_header = skb->data - skb->head;
2490 }
2491
skb_set_inner_network_header(struct sk_buff * skb,const int offset)2492 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2493 const int offset)
2494 {
2495 skb_reset_inner_network_header(skb);
2496 skb->inner_network_header += offset;
2497 }
2498
skb_inner_mac_header(const struct sk_buff * skb)2499 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2500 {
2501 return skb->head + skb->inner_mac_header;
2502 }
2503
skb_reset_inner_mac_header(struct sk_buff * skb)2504 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2505 {
2506 skb->inner_mac_header = skb->data - skb->head;
2507 }
2508
skb_set_inner_mac_header(struct sk_buff * skb,const int offset)2509 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2510 const int offset)
2511 {
2512 skb_reset_inner_mac_header(skb);
2513 skb->inner_mac_header += offset;
2514 }
skb_transport_header_was_set(const struct sk_buff * skb)2515 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2516 {
2517 return skb->transport_header != (typeof(skb->transport_header))~0U;
2518 }
2519
skb_transport_header(const struct sk_buff * skb)2520 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2521 {
2522 return skb->head + skb->transport_header;
2523 }
2524
skb_reset_transport_header(struct sk_buff * skb)2525 static inline void skb_reset_transport_header(struct sk_buff *skb)
2526 {
2527 skb->transport_header = skb->data - skb->head;
2528 }
2529
skb_set_transport_header(struct sk_buff * skb,const int offset)2530 static inline void skb_set_transport_header(struct sk_buff *skb,
2531 const int offset)
2532 {
2533 skb_reset_transport_header(skb);
2534 skb->transport_header += offset;
2535 }
2536
skb_network_header(const struct sk_buff * skb)2537 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2538 {
2539 return skb->head + skb->network_header;
2540 }
2541
skb_reset_network_header(struct sk_buff * skb)2542 static inline void skb_reset_network_header(struct sk_buff *skb)
2543 {
2544 skb->network_header = skb->data - skb->head;
2545 }
2546
skb_set_network_header(struct sk_buff * skb,const int offset)2547 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2548 {
2549 skb_reset_network_header(skb);
2550 skb->network_header += offset;
2551 }
2552
skb_mac_header(const struct sk_buff * skb)2553 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2554 {
2555 return skb->head + skb->mac_header;
2556 }
2557
skb_mac_offset(const struct sk_buff * skb)2558 static inline int skb_mac_offset(const struct sk_buff *skb)
2559 {
2560 return skb_mac_header(skb) - skb->data;
2561 }
2562
skb_mac_header_len(const struct sk_buff * skb)2563 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2564 {
2565 return skb->network_header - skb->mac_header;
2566 }
2567
skb_mac_header_was_set(const struct sk_buff * skb)2568 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2569 {
2570 return skb->mac_header != (typeof(skb->mac_header))~0U;
2571 }
2572
skb_unset_mac_header(struct sk_buff * skb)2573 static inline void skb_unset_mac_header(struct sk_buff *skb)
2574 {
2575 skb->mac_header = (typeof(skb->mac_header))~0U;
2576 }
2577
skb_reset_mac_header(struct sk_buff * skb)2578 static inline void skb_reset_mac_header(struct sk_buff *skb)
2579 {
2580 skb->mac_header = skb->data - skb->head;
2581 }
2582
skb_set_mac_header(struct sk_buff * skb,const int offset)2583 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
2584 {
2585 skb_reset_mac_header(skb);
2586 skb->mac_header += offset;
2587 }
2588
skb_pop_mac_header(struct sk_buff * skb)2589 static inline void skb_pop_mac_header(struct sk_buff *skb)
2590 {
2591 skb->mac_header = skb->network_header;
2592 }
2593
skb_probe_transport_header(struct sk_buff * skb)2594 static inline void skb_probe_transport_header(struct sk_buff *skb)
2595 {
2596 struct flow_keys_basic keys;
2597
2598 if (skb_transport_header_was_set(skb))
2599 return;
2600
2601 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
2602 NULL, 0, 0, 0, 0))
2603 skb_set_transport_header(skb, keys.control.thoff);
2604 }
2605
skb_mac_header_rebuild(struct sk_buff * skb)2606 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
2607 {
2608 if (skb_mac_header_was_set(skb)) {
2609 const unsigned char *old_mac = skb_mac_header(skb);
2610
2611 skb_set_mac_header(skb, -skb->mac_len);
2612 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
2613 }
2614 }
2615
skb_checksum_start_offset(const struct sk_buff * skb)2616 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
2617 {
2618 return skb->csum_start - skb_headroom(skb);
2619 }
2620
skb_checksum_start(const struct sk_buff * skb)2621 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
2622 {
2623 return skb->head + skb->csum_start;
2624 }
2625
skb_transport_offset(const struct sk_buff * skb)2626 static inline int skb_transport_offset(const struct sk_buff *skb)
2627 {
2628 return skb_transport_header(skb) - skb->data;
2629 }
2630
skb_network_header_len(const struct sk_buff * skb)2631 static inline u32 skb_network_header_len(const struct sk_buff *skb)
2632 {
2633 return skb->transport_header - skb->network_header;
2634 }
2635
skb_inner_network_header_len(const struct sk_buff * skb)2636 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
2637 {
2638 return skb->inner_transport_header - skb->inner_network_header;
2639 }
2640
skb_network_offset(const struct sk_buff * skb)2641 static inline int skb_network_offset(const struct sk_buff *skb)
2642 {
2643 return skb_network_header(skb) - skb->data;
2644 }
2645
skb_inner_network_offset(const struct sk_buff * skb)2646 static inline int skb_inner_network_offset(const struct sk_buff *skb)
2647 {
2648 return skb_inner_network_header(skb) - skb->data;
2649 }
2650
pskb_network_may_pull(struct sk_buff * skb,unsigned int len)2651 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
2652 {
2653 return pskb_may_pull(skb, skb_network_offset(skb) + len);
2654 }
2655
2656 /*
2657 * CPUs often take a performance hit when accessing unaligned memory
2658 * locations. The actual performance hit varies, it can be small if the
2659 * hardware handles it or large if we have to take an exception and fix it
2660 * in software.
2661 *
2662 * Since an ethernet header is 14 bytes network drivers often end up with
2663 * the IP header at an unaligned offset. The IP header can be aligned by
2664 * shifting the start of the packet by 2 bytes. Drivers should do this
2665 * with:
2666 *
2667 * skb_reserve(skb, NET_IP_ALIGN);
2668 *
2669 * The downside to this alignment of the IP header is that the DMA is now
2670 * unaligned. On some architectures the cost of an unaligned DMA is high
2671 * and this cost outweighs the gains made by aligning the IP header.
2672 *
2673 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2674 * to be overridden.
2675 */
2676 #ifndef NET_IP_ALIGN
2677 #define NET_IP_ALIGN 2
2678 #endif
2679
2680 /*
2681 * The networking layer reserves some headroom in skb data (via
2682 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2683 * the header has to grow. In the default case, if the header has to grow
2684 * 32 bytes or less we avoid the reallocation.
2685 *
2686 * Unfortunately this headroom changes the DMA alignment of the resulting
2687 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2688 * on some architectures. An architecture can override this value,
2689 * perhaps setting it to a cacheline in size (since that will maintain
2690 * cacheline alignment of the DMA). It must be a power of 2.
2691 *
2692 * Various parts of the networking layer expect at least 32 bytes of
2693 * headroom, you should not reduce this.
2694 *
2695 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2696 * to reduce average number of cache lines per packet.
2697 * get_rps_cpu() for example only access one 64 bytes aligned block :
2698 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2699 */
2700 #ifndef NET_SKB_PAD
2701 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2702 #endif
2703
2704 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
2705
__skb_set_length(struct sk_buff * skb,unsigned int len)2706 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
2707 {
2708 if (WARN_ON(skb_is_nonlinear(skb)))
2709 return;
2710 skb->len = len;
2711 skb_set_tail_pointer(skb, len);
2712 }
2713
__skb_trim(struct sk_buff * skb,unsigned int len)2714 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
2715 {
2716 __skb_set_length(skb, len);
2717 }
2718
2719 void skb_trim(struct sk_buff *skb, unsigned int len);
2720
__pskb_trim(struct sk_buff * skb,unsigned int len)2721 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
2722 {
2723 if (skb->data_len)
2724 return ___pskb_trim(skb, len);
2725 __skb_trim(skb, len);
2726 return 0;
2727 }
2728
pskb_trim(struct sk_buff * skb,unsigned int len)2729 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
2730 {
2731 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
2732 }
2733
2734 /**
2735 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2736 * @skb: buffer to alter
2737 * @len: new length
2738 *
2739 * This is identical to pskb_trim except that the caller knows that
2740 * the skb is not cloned so we should never get an error due to out-
2741 * of-memory.
2742 */
pskb_trim_unique(struct sk_buff * skb,unsigned int len)2743 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
2744 {
2745 int err = pskb_trim(skb, len);
2746 BUG_ON(err);
2747 }
2748
__skb_grow(struct sk_buff * skb,unsigned int len)2749 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
2750 {
2751 unsigned int diff = len - skb->len;
2752
2753 if (skb_tailroom(skb) < diff) {
2754 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
2755 GFP_ATOMIC);
2756 if (ret)
2757 return ret;
2758 }
2759 __skb_set_length(skb, len);
2760 return 0;
2761 }
2762
2763 /**
2764 * skb_orphan - orphan a buffer
2765 * @skb: buffer to orphan
2766 *
2767 * If a buffer currently has an owner then we call the owner's
2768 * destructor function and make the @skb unowned. The buffer continues
2769 * to exist but is no longer charged to its former owner.
2770 */
skb_orphan(struct sk_buff * skb)2771 static inline void skb_orphan(struct sk_buff *skb)
2772 {
2773 if (skb->destructor) {
2774 skb->destructor(skb);
2775 skb->destructor = NULL;
2776 skb->sk = NULL;
2777 } else {
2778 BUG_ON(skb->sk);
2779 }
2780 }
2781
2782 /**
2783 * skb_orphan_frags - orphan the frags contained in a buffer
2784 * @skb: buffer to orphan frags from
2785 * @gfp_mask: allocation mask for replacement pages
2786 *
2787 * For each frag in the SKB which needs a destructor (i.e. has an
2788 * owner) create a copy of that frag and release the original
2789 * page by calling the destructor.
2790 */
skb_orphan_frags(struct sk_buff * skb,gfp_t gfp_mask)2791 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2792 {
2793 if (likely(!skb_zcopy(skb)))
2794 return 0;
2795 if (!skb_zcopy_is_nouarg(skb) &&
2796 skb_uarg(skb)->callback == msg_zerocopy_callback)
2797 return 0;
2798 return skb_copy_ubufs(skb, gfp_mask);
2799 }
2800
2801 /* 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)2802 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
2803 {
2804 if (likely(!skb_zcopy(skb)))
2805 return 0;
2806 return skb_copy_ubufs(skb, gfp_mask);
2807 }
2808
2809 /**
2810 * __skb_queue_purge - empty a list
2811 * @list: list to empty
2812 *
2813 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2814 * the list and one reference dropped. This function does not take the
2815 * list lock and the caller must hold the relevant locks to use it.
2816 */
__skb_queue_purge(struct sk_buff_head * list)2817 static inline void __skb_queue_purge(struct sk_buff_head *list)
2818 {
2819 struct sk_buff *skb;
2820 while ((skb = __skb_dequeue(list)) != NULL)
2821 kfree_skb(skb);
2822 }
2823 void skb_queue_purge(struct sk_buff_head *list);
2824
2825 unsigned int skb_rbtree_purge(struct rb_root *root);
2826
2827 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
2828
2829 /**
2830 * netdev_alloc_frag - allocate a page fragment
2831 * @fragsz: fragment size
2832 *
2833 * Allocates a frag from a page for receive buffer.
2834 * Uses GFP_ATOMIC allocations.
2835 */
netdev_alloc_frag(unsigned int fragsz)2836 static inline void *netdev_alloc_frag(unsigned int fragsz)
2837 {
2838 return __netdev_alloc_frag_align(fragsz, ~0u);
2839 }
2840
netdev_alloc_frag_align(unsigned int fragsz,unsigned int align)2841 static inline void *netdev_alloc_frag_align(unsigned int fragsz,
2842 unsigned int align)
2843 {
2844 WARN_ON_ONCE(!is_power_of_2(align));
2845 return __netdev_alloc_frag_align(fragsz, -align);
2846 }
2847
2848 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2849 gfp_t gfp_mask);
2850
2851 /**
2852 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2853 * @dev: network device to receive on
2854 * @length: length to allocate
2855 *
2856 * Allocate a new &sk_buff and assign it a usage count of one. The
2857 * buffer has unspecified headroom built in. Users should allocate
2858 * the headroom they think they need without accounting for the
2859 * built in space. The built in space is used for optimisations.
2860 *
2861 * %NULL is returned if there is no free memory. Although this function
2862 * allocates memory it can be called from an interrupt.
2863 */
netdev_alloc_skb(struct net_device * dev,unsigned int length)2864 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2865 unsigned int length)
2866 {
2867 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2868 }
2869
2870 /* legacy helper around __netdev_alloc_skb() */
__dev_alloc_skb(unsigned int length,gfp_t gfp_mask)2871 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2872 gfp_t gfp_mask)
2873 {
2874 return __netdev_alloc_skb(NULL, length, gfp_mask);
2875 }
2876
2877 /* legacy helper around netdev_alloc_skb() */
dev_alloc_skb(unsigned int length)2878 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2879 {
2880 return netdev_alloc_skb(NULL, length);
2881 }
2882
2883
__netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length,gfp_t gfp)2884 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2885 unsigned int length, gfp_t gfp)
2886 {
2887 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2888
2889 if (NET_IP_ALIGN && skb)
2890 skb_reserve(skb, NET_IP_ALIGN);
2891 return skb;
2892 }
2893
netdev_alloc_skb_ip_align(struct net_device * dev,unsigned int length)2894 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2895 unsigned int length)
2896 {
2897 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2898 }
2899
skb_free_frag(void * addr)2900 static inline void skb_free_frag(void *addr)
2901 {
2902 page_frag_free(addr);
2903 }
2904
2905 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
2906
napi_alloc_frag(unsigned int fragsz)2907 static inline void *napi_alloc_frag(unsigned int fragsz)
2908 {
2909 return __napi_alloc_frag_align(fragsz, ~0u);
2910 }
2911
napi_alloc_frag_align(unsigned int fragsz,unsigned int align)2912 static inline void *napi_alloc_frag_align(unsigned int fragsz,
2913 unsigned int align)
2914 {
2915 WARN_ON_ONCE(!is_power_of_2(align));
2916 return __napi_alloc_frag_align(fragsz, -align);
2917 }
2918
2919 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
2920 unsigned int length, gfp_t gfp_mask);
napi_alloc_skb(struct napi_struct * napi,unsigned int length)2921 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
2922 unsigned int length)
2923 {
2924 return __napi_alloc_skb(napi, length, GFP_ATOMIC);
2925 }
2926 void napi_consume_skb(struct sk_buff *skb, int budget);
2927
2928 void napi_skb_free_stolen_head(struct sk_buff *skb);
2929 void __kfree_skb_defer(struct sk_buff *skb);
2930
2931 /**
2932 * __dev_alloc_pages - allocate page for network Rx
2933 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2934 * @order: size of the allocation
2935 *
2936 * Allocate a new page.
2937 *
2938 * %NULL is returned if there is no free memory.
2939 */
__dev_alloc_pages(gfp_t gfp_mask,unsigned int order)2940 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
2941 unsigned int order)
2942 {
2943 /* This piece of code contains several assumptions.
2944 * 1. This is for device Rx, therefor a cold page is preferred.
2945 * 2. The expectation is the user wants a compound page.
2946 * 3. If requesting a order 0 page it will not be compound
2947 * due to the check to see if order has a value in prep_new_page
2948 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2949 * code in gfp_to_alloc_flags that should be enforcing this.
2950 */
2951 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
2952
2953 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2954 }
2955
dev_alloc_pages(unsigned int order)2956 static inline struct page *dev_alloc_pages(unsigned int order)
2957 {
2958 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order);
2959 }
2960
2961 /**
2962 * __dev_alloc_page - allocate a page for network Rx
2963 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2964 *
2965 * Allocate a new page.
2966 *
2967 * %NULL is returned if there is no free memory.
2968 */
__dev_alloc_page(gfp_t gfp_mask)2969 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
2970 {
2971 return __dev_alloc_pages(gfp_mask, 0);
2972 }
2973
dev_alloc_page(void)2974 static inline struct page *dev_alloc_page(void)
2975 {
2976 return dev_alloc_pages(0);
2977 }
2978
2979 /**
2980 * dev_page_is_reusable - check whether a page can be reused for network Rx
2981 * @page: the page to test
2982 *
2983 * A page shouldn't be considered for reusing/recycling if it was allocated
2984 * under memory pressure or at a distant memory node.
2985 *
2986 * Returns false if this page should be returned to page allocator, true
2987 * otherwise.
2988 */
dev_page_is_reusable(const struct page * page)2989 static inline bool dev_page_is_reusable(const struct page *page)
2990 {
2991 return likely(page_to_nid(page) == numa_mem_id() &&
2992 !page_is_pfmemalloc(page));
2993 }
2994
2995 /**
2996 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2997 * @page: The page that was allocated from skb_alloc_page
2998 * @skb: The skb that may need pfmemalloc set
2999 */
skb_propagate_pfmemalloc(const struct page * page,struct sk_buff * skb)3000 static inline void skb_propagate_pfmemalloc(const struct page *page,
3001 struct sk_buff *skb)
3002 {
3003 if (page_is_pfmemalloc(page))
3004 skb->pfmemalloc = true;
3005 }
3006
3007 /**
3008 * skb_frag_off() - Returns the offset of a skb fragment
3009 * @frag: the paged fragment
3010 */
skb_frag_off(const skb_frag_t * frag)3011 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3012 {
3013 return frag->bv_offset;
3014 }
3015
3016 /**
3017 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3018 * @frag: skb fragment
3019 * @delta: value to add
3020 */
skb_frag_off_add(skb_frag_t * frag,int delta)3021 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3022 {
3023 frag->bv_offset += delta;
3024 }
3025
3026 /**
3027 * skb_frag_off_set() - Sets the offset of a skb fragment
3028 * @frag: skb fragment
3029 * @offset: offset of fragment
3030 */
skb_frag_off_set(skb_frag_t * frag,unsigned int offset)3031 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3032 {
3033 frag->bv_offset = offset;
3034 }
3035
3036 /**
3037 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3038 * @fragto: skb fragment where offset is set
3039 * @fragfrom: skb fragment offset is copied from
3040 */
skb_frag_off_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3041 static inline void skb_frag_off_copy(skb_frag_t *fragto,
3042 const skb_frag_t *fragfrom)
3043 {
3044 fragto->bv_offset = fragfrom->bv_offset;
3045 }
3046
3047 /**
3048 * skb_frag_page - retrieve the page referred to by a paged fragment
3049 * @frag: the paged fragment
3050 *
3051 * Returns the &struct page associated with @frag.
3052 */
skb_frag_page(const skb_frag_t * frag)3053 static inline struct page *skb_frag_page(const skb_frag_t *frag)
3054 {
3055 return frag->bv_page;
3056 }
3057
3058 /**
3059 * __skb_frag_ref - take an addition reference on a paged fragment.
3060 * @frag: the paged fragment
3061 *
3062 * Takes an additional reference on the paged fragment @frag.
3063 */
__skb_frag_ref(skb_frag_t * frag)3064 static inline void __skb_frag_ref(skb_frag_t *frag)
3065 {
3066 get_page(skb_frag_page(frag));
3067 }
3068
3069 /**
3070 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
3071 * @skb: the buffer
3072 * @f: the fragment offset.
3073 *
3074 * Takes an additional reference on the @f'th paged fragment of @skb.
3075 */
skb_frag_ref(struct sk_buff * skb,int f)3076 static inline void skb_frag_ref(struct sk_buff *skb, int f)
3077 {
3078 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3079 }
3080
3081 /**
3082 * __skb_frag_unref - release a reference on a paged fragment.
3083 * @frag: the paged fragment
3084 *
3085 * Releases a reference on the paged fragment @frag.
3086 */
__skb_frag_unref(skb_frag_t * frag)3087 static inline void __skb_frag_unref(skb_frag_t *frag)
3088 {
3089 put_page(skb_frag_page(frag));
3090 }
3091
3092 /**
3093 * skb_frag_unref - release a reference on a paged fragment of an skb.
3094 * @skb: the buffer
3095 * @f: the fragment offset
3096 *
3097 * Releases a reference on the @f'th paged fragment of @skb.
3098 */
skb_frag_unref(struct sk_buff * skb,int f)3099 static inline void skb_frag_unref(struct sk_buff *skb, int f)
3100 {
3101 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
3102 }
3103
3104 /**
3105 * skb_frag_address - gets the address of the data contained in a paged fragment
3106 * @frag: the paged fragment buffer
3107 *
3108 * Returns the address of the data within @frag. The page must already
3109 * be mapped.
3110 */
skb_frag_address(const skb_frag_t * frag)3111 static inline void *skb_frag_address(const skb_frag_t *frag)
3112 {
3113 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3114 }
3115
3116 /**
3117 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3118 * @frag: the paged fragment buffer
3119 *
3120 * Returns the address of the data within @frag. Checks that the page
3121 * is mapped and returns %NULL otherwise.
3122 */
skb_frag_address_safe(const skb_frag_t * frag)3123 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3124 {
3125 void *ptr = page_address(skb_frag_page(frag));
3126 if (unlikely(!ptr))
3127 return NULL;
3128
3129 return ptr + skb_frag_off(frag);
3130 }
3131
3132 /**
3133 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3134 * @fragto: skb fragment where page is set
3135 * @fragfrom: skb fragment page is copied from
3136 */
skb_frag_page_copy(skb_frag_t * fragto,const skb_frag_t * fragfrom)3137 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3138 const skb_frag_t *fragfrom)
3139 {
3140 fragto->bv_page = fragfrom->bv_page;
3141 }
3142
3143 /**
3144 * __skb_frag_set_page - sets the page contained in a paged fragment
3145 * @frag: the paged fragment
3146 * @page: the page to set
3147 *
3148 * Sets the fragment @frag to contain @page.
3149 */
__skb_frag_set_page(skb_frag_t * frag,struct page * page)3150 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
3151 {
3152 frag->bv_page = page;
3153 }
3154
3155 /**
3156 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
3157 * @skb: the buffer
3158 * @f: the fragment offset
3159 * @page: the page to set
3160 *
3161 * Sets the @f'th fragment of @skb to contain @page.
3162 */
skb_frag_set_page(struct sk_buff * skb,int f,struct page * page)3163 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
3164 struct page *page)
3165 {
3166 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
3167 }
3168
3169 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3170
3171 /**
3172 * skb_frag_dma_map - maps a paged fragment via the DMA API
3173 * @dev: the device to map the fragment to
3174 * @frag: the paged fragment to map
3175 * @offset: the offset within the fragment (starting at the
3176 * fragment's own offset)
3177 * @size: the number of bytes to map
3178 * @dir: the direction of the mapping (``PCI_DMA_*``)
3179 *
3180 * Maps the page associated with @frag to @device.
3181 */
skb_frag_dma_map(struct device * dev,const skb_frag_t * frag,size_t offset,size_t size,enum dma_data_direction dir)3182 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3183 const skb_frag_t *frag,
3184 size_t offset, size_t size,
3185 enum dma_data_direction dir)
3186 {
3187 return dma_map_page(dev, skb_frag_page(frag),
3188 skb_frag_off(frag) + offset, size, dir);
3189 }
3190
pskb_copy(struct sk_buff * skb,gfp_t gfp_mask)3191 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3192 gfp_t gfp_mask)
3193 {
3194 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3195 }
3196
3197
pskb_copy_for_clone(struct sk_buff * skb,gfp_t gfp_mask)3198 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3199 gfp_t gfp_mask)
3200 {
3201 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3202 }
3203
3204
3205 /**
3206 * skb_clone_writable - is the header of a clone writable
3207 * @skb: buffer to check
3208 * @len: length up to which to write
3209 *
3210 * Returns true if modifying the header part of the cloned buffer
3211 * does not requires the data to be copied.
3212 */
skb_clone_writable(const struct sk_buff * skb,unsigned int len)3213 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3214 {
3215 return !skb_header_cloned(skb) &&
3216 skb_headroom(skb) + len <= skb->hdr_len;
3217 }
3218
skb_try_make_writable(struct sk_buff * skb,unsigned int write_len)3219 static inline int skb_try_make_writable(struct sk_buff *skb,
3220 unsigned int write_len)
3221 {
3222 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3223 pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3224 }
3225
__skb_cow(struct sk_buff * skb,unsigned int headroom,int cloned)3226 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3227 int cloned)
3228 {
3229 int delta = 0;
3230
3231 if (headroom > skb_headroom(skb))
3232 delta = headroom - skb_headroom(skb);
3233
3234 if (delta || cloned)
3235 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3236 GFP_ATOMIC);
3237 return 0;
3238 }
3239
3240 /**
3241 * skb_cow - copy header of skb when it is required
3242 * @skb: buffer to cow
3243 * @headroom: needed headroom
3244 *
3245 * If the skb passed lacks sufficient headroom or its data part
3246 * is shared, data is reallocated. If reallocation fails, an error
3247 * is returned and original skb is not changed.
3248 *
3249 * The result is skb with writable area skb->head...skb->tail
3250 * and at least @headroom of space at head.
3251 */
skb_cow(struct sk_buff * skb,unsigned int headroom)3252 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3253 {
3254 return __skb_cow(skb, headroom, skb_cloned(skb));
3255 }
3256
3257 /**
3258 * skb_cow_head - skb_cow but only making the head writable
3259 * @skb: buffer to cow
3260 * @headroom: needed headroom
3261 *
3262 * This function is identical to skb_cow except that we replace the
3263 * skb_cloned check by skb_header_cloned. It should be used when
3264 * you only need to push on some header and do not need to modify
3265 * the data.
3266 */
skb_cow_head(struct sk_buff * skb,unsigned int headroom)3267 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3268 {
3269 return __skb_cow(skb, headroom, skb_header_cloned(skb));
3270 }
3271
3272 /**
3273 * skb_padto - pad an skbuff up to a minimal size
3274 * @skb: buffer to pad
3275 * @len: minimal length
3276 *
3277 * Pads up a buffer to ensure the trailing bytes exist and are
3278 * blanked. If the buffer already contains sufficient data it
3279 * is untouched. Otherwise it is extended. Returns zero on
3280 * success. The skb is freed on error.
3281 */
skb_padto(struct sk_buff * skb,unsigned int len)3282 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3283 {
3284 unsigned int size = skb->len;
3285 if (likely(size >= len))
3286 return 0;
3287 return skb_pad(skb, len - size);
3288 }
3289
3290 /**
3291 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3292 * @skb: buffer to pad
3293 * @len: minimal length
3294 * @free_on_error: free buffer on error
3295 *
3296 * Pads up a buffer to ensure the trailing bytes exist and are
3297 * blanked. If the buffer already contains sufficient data it
3298 * is untouched. Otherwise it is extended. Returns zero on
3299 * success. The skb is freed on error if @free_on_error is true.
3300 */
__skb_put_padto(struct sk_buff * skb,unsigned int len,bool free_on_error)3301 static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3302 unsigned int len,
3303 bool free_on_error)
3304 {
3305 unsigned int size = skb->len;
3306
3307 if (unlikely(size < len)) {
3308 len -= size;
3309 if (__skb_pad(skb, len, free_on_error))
3310 return -ENOMEM;
3311 __skb_put(skb, len);
3312 }
3313 return 0;
3314 }
3315
3316 /**
3317 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3318 * @skb: buffer to pad
3319 * @len: minimal length
3320 *
3321 * Pads up a buffer to ensure the trailing bytes exist and are
3322 * blanked. If the buffer already contains sufficient data it
3323 * is untouched. Otherwise it is extended. Returns zero on
3324 * success. The skb is freed on error.
3325 */
skb_put_padto(struct sk_buff * skb,unsigned int len)3326 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3327 {
3328 return __skb_put_padto(skb, len, true);
3329 }
3330
skb_add_data(struct sk_buff * skb,struct iov_iter * from,int copy)3331 static inline int skb_add_data(struct sk_buff *skb,
3332 struct iov_iter *from, int copy)
3333 {
3334 const int off = skb->len;
3335
3336 if (skb->ip_summed == CHECKSUM_NONE) {
3337 __wsum csum = 0;
3338 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3339 &csum, from)) {
3340 skb->csum = csum_block_add(skb->csum, csum, off);
3341 return 0;
3342 }
3343 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3344 return 0;
3345
3346 __skb_trim(skb, off);
3347 return -EFAULT;
3348 }
3349
skb_can_coalesce(struct sk_buff * skb,int i,const struct page * page,int off)3350 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3351 const struct page *page, int off)
3352 {
3353 if (skb_zcopy(skb))
3354 return false;
3355 if (i) {
3356 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3357
3358 return page == skb_frag_page(frag) &&
3359 off == skb_frag_off(frag) + skb_frag_size(frag);
3360 }
3361 return false;
3362 }
3363
__skb_linearize(struct sk_buff * skb)3364 static inline int __skb_linearize(struct sk_buff *skb)
3365 {
3366 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3367 }
3368
3369 /**
3370 * skb_linearize - convert paged skb to linear one
3371 * @skb: buffer to linarize
3372 *
3373 * If there is no free memory -ENOMEM is returned, otherwise zero
3374 * is returned and the old skb data released.
3375 */
skb_linearize(struct sk_buff * skb)3376 static inline int skb_linearize(struct sk_buff *skb)
3377 {
3378 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3379 }
3380
3381 /**
3382 * skb_has_shared_frag - can any frag be overwritten
3383 * @skb: buffer to test
3384 *
3385 * Return true if the skb has at least one frag that might be modified
3386 * by an external entity (as in vmsplice()/sendfile())
3387 */
skb_has_shared_frag(const struct sk_buff * skb)3388 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3389 {
3390 return skb_is_nonlinear(skb) &&
3391 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3392 }
3393
3394 /**
3395 * skb_linearize_cow - make sure skb is linear and writable
3396 * @skb: buffer to process
3397 *
3398 * If there is no free memory -ENOMEM is returned, otherwise zero
3399 * is returned and the old skb data released.
3400 */
skb_linearize_cow(struct sk_buff * skb)3401 static inline int skb_linearize_cow(struct sk_buff *skb)
3402 {
3403 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3404 __skb_linearize(skb) : 0;
3405 }
3406
3407 static __always_inline void
__skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3408 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3409 unsigned int off)
3410 {
3411 if (skb->ip_summed == CHECKSUM_COMPLETE)
3412 skb->csum = csum_block_sub(skb->csum,
3413 csum_partial(start, len, 0), off);
3414 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3415 skb_checksum_start_offset(skb) < 0)
3416 skb->ip_summed = CHECKSUM_NONE;
3417 }
3418
3419 /**
3420 * skb_postpull_rcsum - update checksum for received skb after pull
3421 * @skb: buffer to update
3422 * @start: start of data before pull
3423 * @len: length of data pulled
3424 *
3425 * After doing a pull on a received packet, you need to call this to
3426 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3427 * CHECKSUM_NONE so that it can be recomputed from scratch.
3428 */
skb_postpull_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3429 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3430 const void *start, unsigned int len)
3431 {
3432 __skb_postpull_rcsum(skb, start, len, 0);
3433 }
3434
3435 static __always_inline void
__skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len,unsigned int off)3436 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3437 unsigned int off)
3438 {
3439 if (skb->ip_summed == CHECKSUM_COMPLETE)
3440 skb->csum = csum_block_add(skb->csum,
3441 csum_partial(start, len, 0), off);
3442 }
3443
3444 /**
3445 * skb_postpush_rcsum - update checksum for received skb after push
3446 * @skb: buffer to update
3447 * @start: start of data after push
3448 * @len: length of data pushed
3449 *
3450 * After doing a push on a received packet, you need to call this to
3451 * update the CHECKSUM_COMPLETE checksum.
3452 */
skb_postpush_rcsum(struct sk_buff * skb,const void * start,unsigned int len)3453 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3454 const void *start, unsigned int len)
3455 {
3456 __skb_postpush_rcsum(skb, start, len, 0);
3457 }
3458
3459 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3460
3461 /**
3462 * skb_push_rcsum - push skb and update receive checksum
3463 * @skb: buffer to update
3464 * @len: length of data pulled
3465 *
3466 * This function performs an skb_push on the packet and updates
3467 * the CHECKSUM_COMPLETE checksum. It should be used on
3468 * receive path processing instead of skb_push unless you know
3469 * that the checksum difference is zero (e.g., a valid IP header)
3470 * or you are setting ip_summed to CHECKSUM_NONE.
3471 */
skb_push_rcsum(struct sk_buff * skb,unsigned int len)3472 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3473 {
3474 skb_push(skb, len);
3475 skb_postpush_rcsum(skb, skb->data, len);
3476 return skb->data;
3477 }
3478
3479 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3480 /**
3481 * pskb_trim_rcsum - trim received skb and update checksum
3482 * @skb: buffer to trim
3483 * @len: new length
3484 *
3485 * This is exactly the same as pskb_trim except that it ensures the
3486 * checksum of received packets are still valid after the operation.
3487 * It can change skb pointers.
3488 */
3489
pskb_trim_rcsum(struct sk_buff * skb,unsigned int len)3490 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3491 {
3492 if (likely(len >= skb->len))
3493 return 0;
3494 return pskb_trim_rcsum_slow(skb, len);
3495 }
3496
__skb_trim_rcsum(struct sk_buff * skb,unsigned int len)3497 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3498 {
3499 if (skb->ip_summed == CHECKSUM_COMPLETE)
3500 skb->ip_summed = CHECKSUM_NONE;
3501 __skb_trim(skb, len);
3502 return 0;
3503 }
3504
__skb_grow_rcsum(struct sk_buff * skb,unsigned int len)3505 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3506 {
3507 if (skb->ip_summed == CHECKSUM_COMPLETE)
3508 skb->ip_summed = CHECKSUM_NONE;
3509 return __skb_grow(skb, len);
3510 }
3511
3512 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3513 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3514 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3515 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3516 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3517
3518 #define skb_queue_walk(queue, skb) \
3519 for (skb = (queue)->next; \
3520 skb != (struct sk_buff *)(queue); \
3521 skb = skb->next)
3522
3523 #define skb_queue_walk_safe(queue, skb, tmp) \
3524 for (skb = (queue)->next, tmp = skb->next; \
3525 skb != (struct sk_buff *)(queue); \
3526 skb = tmp, tmp = skb->next)
3527
3528 #define skb_queue_walk_from(queue, skb) \
3529 for (; skb != (struct sk_buff *)(queue); \
3530 skb = skb->next)
3531
3532 #define skb_rbtree_walk(skb, root) \
3533 for (skb = skb_rb_first(root); skb != NULL; \
3534 skb = skb_rb_next(skb))
3535
3536 #define skb_rbtree_walk_from(skb) \
3537 for (; skb != NULL; \
3538 skb = skb_rb_next(skb))
3539
3540 #define skb_rbtree_walk_from_safe(skb, tmp) \
3541 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3542 skb = tmp)
3543
3544 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3545 for (tmp = skb->next; \
3546 skb != (struct sk_buff *)(queue); \
3547 skb = tmp, tmp = skb->next)
3548
3549 #define skb_queue_reverse_walk(queue, skb) \
3550 for (skb = (queue)->prev; \
3551 skb != (struct sk_buff *)(queue); \
3552 skb = skb->prev)
3553
3554 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3555 for (skb = (queue)->prev, tmp = skb->prev; \
3556 skb != (struct sk_buff *)(queue); \
3557 skb = tmp, tmp = skb->prev)
3558
3559 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3560 for (tmp = skb->prev; \
3561 skb != (struct sk_buff *)(queue); \
3562 skb = tmp, tmp = skb->prev)
3563
skb_has_frag_list(const struct sk_buff * skb)3564 static inline bool skb_has_frag_list(const struct sk_buff *skb)
3565 {
3566 return skb_shinfo(skb)->frag_list != NULL;
3567 }
3568
skb_frag_list_init(struct sk_buff * skb)3569 static inline void skb_frag_list_init(struct sk_buff *skb)
3570 {
3571 skb_shinfo(skb)->frag_list = NULL;
3572 }
3573
3574 #define skb_walk_frags(skb, iter) \
3575 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3576
3577
3578 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
3579 int *err, long *timeo_p,
3580 const struct sk_buff *skb);
3581 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
3582 struct sk_buff_head *queue,
3583 unsigned int flags,
3584 int *off, int *err,
3585 struct sk_buff **last);
3586 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
3587 struct sk_buff_head *queue,
3588 unsigned int flags, int *off, int *err,
3589 struct sk_buff **last);
3590 struct sk_buff *__skb_recv_datagram(struct sock *sk,
3591 struct sk_buff_head *sk_queue,
3592 unsigned int flags, int *off, int *err);
3593 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
3594 int *err);
3595 __poll_t datagram_poll(struct file *file, struct socket *sock,
3596 struct poll_table_struct *wait);
3597 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
3598 struct iov_iter *to, int size);
skb_copy_datagram_msg(const struct sk_buff * from,int offset,struct msghdr * msg,int size)3599 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
3600 struct msghdr *msg, int size)
3601 {
3602 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3603 }
3604 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
3605 struct msghdr *msg);
3606 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
3607 struct iov_iter *to, int len,
3608 struct ahash_request *hash);
3609 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
3610 struct iov_iter *from, int len);
3611 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
3612 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
3613 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
skb_free_datagram_locked(struct sock * sk,struct sk_buff * skb)3614 static inline void skb_free_datagram_locked(struct sock *sk,
3615 struct sk_buff *skb)
3616 {
3617 __skb_free_datagram_locked(sk, skb, 0);
3618 }
3619 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
3620 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
3621 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
3622 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
3623 int len);
3624 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
3625 struct pipe_inode_info *pipe, unsigned int len,
3626 unsigned int flags);
3627 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
3628 int len);
3629 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
3630 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
3631 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
3632 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
3633 int len, int hlen);
3634 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
3635 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
3636 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
3637 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
3638 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
3639 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
3640 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
3641 unsigned int offset);
3642 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
3643 int skb_ensure_writable(struct sk_buff *skb, int write_len);
3644 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
3645 int skb_vlan_pop(struct sk_buff *skb);
3646 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
3647 int skb_eth_pop(struct sk_buff *skb);
3648 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
3649 const unsigned char *src);
3650 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
3651 int mac_len, bool ethernet);
3652 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
3653 bool ethernet);
3654 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
3655 int skb_mpls_dec_ttl(struct sk_buff *skb);
3656 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
3657 gfp_t gfp);
3658
memcpy_from_msg(void * data,struct msghdr * msg,int len)3659 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
3660 {
3661 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
3662 }
3663
memcpy_to_msg(struct msghdr * msg,void * data,int len)3664 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
3665 {
3666 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
3667 }
3668
3669 struct skb_checksum_ops {
3670 __wsum (*update)(const void *mem, int len, __wsum wsum);
3671 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
3672 };
3673
3674 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
3675
3676 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
3677 __wsum csum, const struct skb_checksum_ops *ops);
3678 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
3679 __wsum csum);
3680
3681 static inline void * __must_check
__skb_header_pointer(const struct sk_buff * skb,int offset,int len,const void * data,int hlen,void * buffer)3682 __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
3683 const void *data, int hlen, void *buffer)
3684 {
3685 if (likely(hlen - offset >= len))
3686 return (void *)data + offset;
3687
3688 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
3689 return NULL;
3690
3691 return buffer;
3692 }
3693
3694 static inline void * __must_check
skb_header_pointer(const struct sk_buff * skb,int offset,int len,void * buffer)3695 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
3696 {
3697 return __skb_header_pointer(skb, offset, len, skb->data,
3698 skb_headlen(skb), buffer);
3699 }
3700
3701 /**
3702 * skb_needs_linearize - check if we need to linearize a given skb
3703 * depending on the given device features.
3704 * @skb: socket buffer to check
3705 * @features: net device features
3706 *
3707 * Returns true if either:
3708 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3709 * 2. skb is fragmented and the device does not support SG.
3710 */
skb_needs_linearize(struct sk_buff * skb,netdev_features_t features)3711 static inline bool skb_needs_linearize(struct sk_buff *skb,
3712 netdev_features_t features)
3713 {
3714 return skb_is_nonlinear(skb) &&
3715 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
3716 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
3717 }
3718
skb_copy_from_linear_data(const struct sk_buff * skb,void * to,const unsigned int len)3719 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
3720 void *to,
3721 const unsigned int len)
3722 {
3723 memcpy(to, skb->data, len);
3724 }
3725
skb_copy_from_linear_data_offset(const struct sk_buff * skb,const int offset,void * to,const unsigned int len)3726 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
3727 const int offset, void *to,
3728 const unsigned int len)
3729 {
3730 memcpy(to, skb->data + offset, len);
3731 }
3732
skb_copy_to_linear_data(struct sk_buff * skb,const void * from,const unsigned int len)3733 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
3734 const void *from,
3735 const unsigned int len)
3736 {
3737 memcpy(skb->data, from, len);
3738 }
3739
skb_copy_to_linear_data_offset(struct sk_buff * skb,const int offset,const void * from,const unsigned int len)3740 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
3741 const int offset,
3742 const void *from,
3743 const unsigned int len)
3744 {
3745 memcpy(skb->data + offset, from, len);
3746 }
3747
3748 void skb_init(void);
3749
skb_get_ktime(const struct sk_buff * skb)3750 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
3751 {
3752 return skb->tstamp;
3753 }
3754
3755 /**
3756 * skb_get_timestamp - get timestamp from a skb
3757 * @skb: skb to get stamp from
3758 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
3759 *
3760 * Timestamps are stored in the skb as offsets to a base timestamp.
3761 * This function converts the offset back to a struct timeval and stores
3762 * it in stamp.
3763 */
skb_get_timestamp(const struct sk_buff * skb,struct __kernel_old_timeval * stamp)3764 static inline void skb_get_timestamp(const struct sk_buff *skb,
3765 struct __kernel_old_timeval *stamp)
3766 {
3767 *stamp = ns_to_kernel_old_timeval(skb->tstamp);
3768 }
3769
skb_get_new_timestamp(const struct sk_buff * skb,struct __kernel_sock_timeval * stamp)3770 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
3771 struct __kernel_sock_timeval *stamp)
3772 {
3773 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3774
3775 stamp->tv_sec = ts.tv_sec;
3776 stamp->tv_usec = ts.tv_nsec / 1000;
3777 }
3778
skb_get_timestampns(const struct sk_buff * skb,struct __kernel_old_timespec * stamp)3779 static inline void skb_get_timestampns(const struct sk_buff *skb,
3780 struct __kernel_old_timespec *stamp)
3781 {
3782 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3783
3784 stamp->tv_sec = ts.tv_sec;
3785 stamp->tv_nsec = ts.tv_nsec;
3786 }
3787
skb_get_new_timestampns(const struct sk_buff * skb,struct __kernel_timespec * stamp)3788 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
3789 struct __kernel_timespec *stamp)
3790 {
3791 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3792
3793 stamp->tv_sec = ts.tv_sec;
3794 stamp->tv_nsec = ts.tv_nsec;
3795 }
3796
__net_timestamp(struct sk_buff * skb)3797 static inline void __net_timestamp(struct sk_buff *skb)
3798 {
3799 skb->tstamp = ktime_get_real();
3800 }
3801
net_timedelta(ktime_t t)3802 static inline ktime_t net_timedelta(ktime_t t)
3803 {
3804 return ktime_sub(ktime_get_real(), t);
3805 }
3806
net_invalid_timestamp(void)3807 static inline ktime_t net_invalid_timestamp(void)
3808 {
3809 return 0;
3810 }
3811
skb_metadata_len(const struct sk_buff * skb)3812 static inline u8 skb_metadata_len(const struct sk_buff *skb)
3813 {
3814 return skb_shinfo(skb)->meta_len;
3815 }
3816
skb_metadata_end(const struct sk_buff * skb)3817 static inline void *skb_metadata_end(const struct sk_buff *skb)
3818 {
3819 return skb_mac_header(skb);
3820 }
3821
__skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b,u8 meta_len)3822 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
3823 const struct sk_buff *skb_b,
3824 u8 meta_len)
3825 {
3826 const void *a = skb_metadata_end(skb_a);
3827 const void *b = skb_metadata_end(skb_b);
3828 /* Using more efficient varaiant than plain call to memcmp(). */
3829 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
3830 u64 diffs = 0;
3831
3832 switch (meta_len) {
3833 #define __it(x, op) (x -= sizeof(u##op))
3834 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
3835 case 32: diffs |= __it_diff(a, b, 64);
3836 fallthrough;
3837 case 24: diffs |= __it_diff(a, b, 64);
3838 fallthrough;
3839 case 16: diffs |= __it_diff(a, b, 64);
3840 fallthrough;
3841 case 8: diffs |= __it_diff(a, b, 64);
3842 break;
3843 case 28: diffs |= __it_diff(a, b, 64);
3844 fallthrough;
3845 case 20: diffs |= __it_diff(a, b, 64);
3846 fallthrough;
3847 case 12: diffs |= __it_diff(a, b, 64);
3848 fallthrough;
3849 case 4: diffs |= __it_diff(a, b, 32);
3850 break;
3851 }
3852 return diffs;
3853 #else
3854 return memcmp(a - meta_len, b - meta_len, meta_len);
3855 #endif
3856 }
3857
skb_metadata_differs(const struct sk_buff * skb_a,const struct sk_buff * skb_b)3858 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
3859 const struct sk_buff *skb_b)
3860 {
3861 u8 len_a = skb_metadata_len(skb_a);
3862 u8 len_b = skb_metadata_len(skb_b);
3863
3864 if (!(len_a | len_b))
3865 return false;
3866
3867 return len_a != len_b ?
3868 true : __skb_metadata_differs(skb_a, skb_b, len_a);
3869 }
3870
skb_metadata_set(struct sk_buff * skb,u8 meta_len)3871 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
3872 {
3873 skb_shinfo(skb)->meta_len = meta_len;
3874 }
3875
skb_metadata_clear(struct sk_buff * skb)3876 static inline void skb_metadata_clear(struct sk_buff *skb)
3877 {
3878 skb_metadata_set(skb, 0);
3879 }
3880
3881 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
3882
3883 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3884
3885 void skb_clone_tx_timestamp(struct sk_buff *skb);
3886 bool skb_defer_rx_timestamp(struct sk_buff *skb);
3887
3888 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3889
skb_clone_tx_timestamp(struct sk_buff * skb)3890 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
3891 {
3892 }
3893
skb_defer_rx_timestamp(struct sk_buff * skb)3894 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
3895 {
3896 return false;
3897 }
3898
3899 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3900
3901 /**
3902 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3903 *
3904 * PHY drivers may accept clones of transmitted packets for
3905 * timestamping via their phy_driver.txtstamp method. These drivers
3906 * must call this function to return the skb back to the stack with a
3907 * timestamp.
3908 *
3909 * @skb: clone of the original outgoing packet
3910 * @hwtstamps: hardware time stamps
3911 *
3912 */
3913 void skb_complete_tx_timestamp(struct sk_buff *skb,
3914 struct skb_shared_hwtstamps *hwtstamps);
3915
3916 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
3917 struct skb_shared_hwtstamps *hwtstamps,
3918 struct sock *sk, int tstype);
3919
3920 /**
3921 * skb_tstamp_tx - queue clone of skb with send time stamps
3922 * @orig_skb: the original outgoing packet
3923 * @hwtstamps: hardware time stamps, may be NULL if not available
3924 *
3925 * If the skb has a socket associated, then this function clones the
3926 * skb (thus sharing the actual data and optional structures), stores
3927 * the optional hardware time stamping information (if non NULL) or
3928 * generates a software time stamp (otherwise), then queues the clone
3929 * to the error queue of the socket. Errors are silently ignored.
3930 */
3931 void skb_tstamp_tx(struct sk_buff *orig_skb,
3932 struct skb_shared_hwtstamps *hwtstamps);
3933
3934 /**
3935 * skb_tx_timestamp() - Driver hook for transmit timestamping
3936 *
3937 * Ethernet MAC Drivers should call this function in their hard_xmit()
3938 * function immediately before giving the sk_buff to the MAC hardware.
3939 *
3940 * Specifically, one should make absolutely sure that this function is
3941 * called before TX completion of this packet can trigger. Otherwise
3942 * the packet could potentially already be freed.
3943 *
3944 * @skb: A socket buffer.
3945 */
skb_tx_timestamp(struct sk_buff * skb)3946 static inline void skb_tx_timestamp(struct sk_buff *skb)
3947 {
3948 skb_clone_tx_timestamp(skb);
3949 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
3950 skb_tstamp_tx(skb, NULL);
3951 }
3952
3953 /**
3954 * skb_complete_wifi_ack - deliver skb with wifi status
3955 *
3956 * @skb: the original outgoing packet
3957 * @acked: ack status
3958 *
3959 */
3960 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
3961
3962 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
3963 __sum16 __skb_checksum_complete(struct sk_buff *skb);
3964
skb_csum_unnecessary(const struct sk_buff * skb)3965 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
3966 {
3967 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
3968 skb->csum_valid ||
3969 (skb->ip_summed == CHECKSUM_PARTIAL &&
3970 skb_checksum_start_offset(skb) >= 0));
3971 }
3972
3973 /**
3974 * skb_checksum_complete - Calculate checksum of an entire packet
3975 * @skb: packet to process
3976 *
3977 * This function calculates the checksum over the entire packet plus
3978 * the value of skb->csum. The latter can be used to supply the
3979 * checksum of a pseudo header as used by TCP/UDP. It returns the
3980 * checksum.
3981 *
3982 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3983 * this function can be used to verify that checksum on received
3984 * packets. In that case the function should return zero if the
3985 * checksum is correct. In particular, this function will return zero
3986 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3987 * hardware has already verified the correctness of the checksum.
3988 */
skb_checksum_complete(struct sk_buff * skb)3989 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
3990 {
3991 return skb_csum_unnecessary(skb) ?
3992 0 : __skb_checksum_complete(skb);
3993 }
3994
__skb_decr_checksum_unnecessary(struct sk_buff * skb)3995 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
3996 {
3997 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3998 if (skb->csum_level == 0)
3999 skb->ip_summed = CHECKSUM_NONE;
4000 else
4001 skb->csum_level--;
4002 }
4003 }
4004
__skb_incr_checksum_unnecessary(struct sk_buff * skb)4005 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4006 {
4007 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4008 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4009 skb->csum_level++;
4010 } else if (skb->ip_summed == CHECKSUM_NONE) {
4011 skb->ip_summed = CHECKSUM_UNNECESSARY;
4012 skb->csum_level = 0;
4013 }
4014 }
4015
__skb_reset_checksum_unnecessary(struct sk_buff * skb)4016 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4017 {
4018 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4019 skb->ip_summed = CHECKSUM_NONE;
4020 skb->csum_level = 0;
4021 }
4022 }
4023
4024 /* Check if we need to perform checksum complete validation.
4025 *
4026 * Returns true if checksum complete is needed, false otherwise
4027 * (either checksum is unnecessary or zero checksum is allowed).
4028 */
__skb_checksum_validate_needed(struct sk_buff * skb,bool zero_okay,__sum16 check)4029 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4030 bool zero_okay,
4031 __sum16 check)
4032 {
4033 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4034 skb->csum_valid = 1;
4035 __skb_decr_checksum_unnecessary(skb);
4036 return false;
4037 }
4038
4039 return true;
4040 }
4041
4042 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4043 * in checksum_init.
4044 */
4045 #define CHECKSUM_BREAK 76
4046
4047 /* Unset checksum-complete
4048 *
4049 * Unset checksum complete can be done when packet is being modified
4050 * (uncompressed for instance) and checksum-complete value is
4051 * invalidated.
4052 */
skb_checksum_complete_unset(struct sk_buff * skb)4053 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4054 {
4055 if (skb->ip_summed == CHECKSUM_COMPLETE)
4056 skb->ip_summed = CHECKSUM_NONE;
4057 }
4058
4059 /* Validate (init) checksum based on checksum complete.
4060 *
4061 * Return values:
4062 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
4063 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4064 * checksum is stored in skb->csum for use in __skb_checksum_complete
4065 * non-zero: value of invalid checksum
4066 *
4067 */
__skb_checksum_validate_complete(struct sk_buff * skb,bool complete,__wsum psum)4068 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4069 bool complete,
4070 __wsum psum)
4071 {
4072 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4073 if (!csum_fold(csum_add(psum, skb->csum))) {
4074 skb->csum_valid = 1;
4075 return 0;
4076 }
4077 }
4078
4079 skb->csum = psum;
4080
4081 if (complete || skb->len <= CHECKSUM_BREAK) {
4082 __sum16 csum;
4083
4084 csum = __skb_checksum_complete(skb);
4085 skb->csum_valid = !csum;
4086 return csum;
4087 }
4088
4089 return 0;
4090 }
4091
null_compute_pseudo(struct sk_buff * skb,int proto)4092 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4093 {
4094 return 0;
4095 }
4096
4097 /* Perform checksum validate (init). Note that this is a macro since we only
4098 * want to calculate the pseudo header which is an input function if necessary.
4099 * First we try to validate without any computation (checksum unnecessary) and
4100 * then calculate based on checksum complete calling the function to compute
4101 * pseudo header.
4102 *
4103 * Return values:
4104 * 0: checksum is validated or try to in skb_checksum_complete
4105 * non-zero: value of invalid checksum
4106 */
4107 #define __skb_checksum_validate(skb, proto, complete, \
4108 zero_okay, check, compute_pseudo) \
4109 ({ \
4110 __sum16 __ret = 0; \
4111 skb->csum_valid = 0; \
4112 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4113 __ret = __skb_checksum_validate_complete(skb, \
4114 complete, compute_pseudo(skb, proto)); \
4115 __ret; \
4116 })
4117
4118 #define skb_checksum_init(skb, proto, compute_pseudo) \
4119 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4120
4121 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4122 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4123
4124 #define skb_checksum_validate(skb, proto, compute_pseudo) \
4125 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4126
4127 #define skb_checksum_validate_zero_check(skb, proto, check, \
4128 compute_pseudo) \
4129 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4130
4131 #define skb_checksum_simple_validate(skb) \
4132 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4133
__skb_checksum_convert_check(struct sk_buff * skb)4134 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4135 {
4136 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4137 }
4138
__skb_checksum_convert(struct sk_buff * skb,__wsum pseudo)4139 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4140 {
4141 skb->csum = ~pseudo;
4142 skb->ip_summed = CHECKSUM_COMPLETE;
4143 }
4144
4145 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4146 do { \
4147 if (__skb_checksum_convert_check(skb)) \
4148 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4149 } while (0)
4150
skb_remcsum_adjust_partial(struct sk_buff * skb,void * ptr,u16 start,u16 offset)4151 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4152 u16 start, u16 offset)
4153 {
4154 skb->ip_summed = CHECKSUM_PARTIAL;
4155 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4156 skb->csum_offset = offset - start;
4157 }
4158
4159 /* Update skbuf and packet to reflect the remote checksum offload operation.
4160 * When called, ptr indicates the starting point for skb->csum when
4161 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4162 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4163 */
skb_remcsum_process(struct sk_buff * skb,void * ptr,int start,int offset,bool nopartial)4164 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4165 int start, int offset, bool nopartial)
4166 {
4167 __wsum delta;
4168
4169 if (!nopartial) {
4170 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4171 return;
4172 }
4173
4174 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4175 __skb_checksum_complete(skb);
4176 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4177 }
4178
4179 delta = remcsum_adjust(ptr, skb->csum, start, offset);
4180
4181 /* Adjust skb->csum since we changed the packet */
4182 skb->csum = csum_add(skb->csum, delta);
4183 }
4184
skb_nfct(const struct sk_buff * skb)4185 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4186 {
4187 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4188 return (void *)(skb->_nfct & NFCT_PTRMASK);
4189 #else
4190 return NULL;
4191 #endif
4192 }
4193
skb_get_nfct(const struct sk_buff * skb)4194 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4195 {
4196 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4197 return skb->_nfct;
4198 #else
4199 return 0UL;
4200 #endif
4201 }
4202
skb_set_nfct(struct sk_buff * skb,unsigned long nfct)4203 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4204 {
4205 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4206 skb->_nfct = nfct;
4207 #endif
4208 }
4209
4210 #ifdef CONFIG_SKB_EXTENSIONS
4211 enum skb_ext_id {
4212 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4213 SKB_EXT_BRIDGE_NF,
4214 #endif
4215 #ifdef CONFIG_XFRM
4216 SKB_EXT_SEC_PATH,
4217 #endif
4218 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4219 TC_SKB_EXT,
4220 #endif
4221 #if IS_ENABLED(CONFIG_MPTCP)
4222 SKB_EXT_MPTCP,
4223 #endif
4224 SKB_EXT_NUM, /* must be last */
4225 };
4226
4227 /**
4228 * struct skb_ext - sk_buff extensions
4229 * @refcnt: 1 on allocation, deallocated on 0
4230 * @offset: offset to add to @data to obtain extension address
4231 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4232 * @data: start of extension data, variable sized
4233 *
4234 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4235 * to use 'u8' types while allowing up to 2kb worth of extension data.
4236 */
4237 struct skb_ext {
4238 refcount_t refcnt;
4239 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4240 u8 chunks; /* same */
4241 char data[] __aligned(8);
4242 };
4243
4244 struct skb_ext *__skb_ext_alloc(gfp_t flags);
4245 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4246 struct skb_ext *ext);
4247 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4248 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4249 void __skb_ext_put(struct skb_ext *ext);
4250
skb_ext_put(struct sk_buff * skb)4251 static inline void skb_ext_put(struct sk_buff *skb)
4252 {
4253 if (skb->active_extensions)
4254 __skb_ext_put(skb->extensions);
4255 }
4256
__skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4257 static inline void __skb_ext_copy(struct sk_buff *dst,
4258 const struct sk_buff *src)
4259 {
4260 dst->active_extensions = src->active_extensions;
4261
4262 if (src->active_extensions) {
4263 struct skb_ext *ext = src->extensions;
4264
4265 refcount_inc(&ext->refcnt);
4266 dst->extensions = ext;
4267 }
4268 }
4269
skb_ext_copy(struct sk_buff * dst,const struct sk_buff * src)4270 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4271 {
4272 skb_ext_put(dst);
4273 __skb_ext_copy(dst, src);
4274 }
4275
__skb_ext_exist(const struct skb_ext * ext,enum skb_ext_id i)4276 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4277 {
4278 return !!ext->offset[i];
4279 }
4280
skb_ext_exist(const struct sk_buff * skb,enum skb_ext_id id)4281 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4282 {
4283 return skb->active_extensions & (1 << id);
4284 }
4285
skb_ext_del(struct sk_buff * skb,enum skb_ext_id id)4286 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4287 {
4288 if (skb_ext_exist(skb, id))
4289 __skb_ext_del(skb, id);
4290 }
4291
skb_ext_find(const struct sk_buff * skb,enum skb_ext_id id)4292 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4293 {
4294 if (skb_ext_exist(skb, id)) {
4295 struct skb_ext *ext = skb->extensions;
4296
4297 return (void *)ext + (ext->offset[id] << 3);
4298 }
4299
4300 return NULL;
4301 }
4302
skb_ext_reset(struct sk_buff * skb)4303 static inline void skb_ext_reset(struct sk_buff *skb)
4304 {
4305 if (unlikely(skb->active_extensions)) {
4306 __skb_ext_put(skb->extensions);
4307 skb->active_extensions = 0;
4308 }
4309 }
4310
skb_has_extensions(struct sk_buff * skb)4311 static inline bool skb_has_extensions(struct sk_buff *skb)
4312 {
4313 return unlikely(skb->active_extensions);
4314 }
4315 #else
skb_ext_put(struct sk_buff * skb)4316 static inline void skb_ext_put(struct sk_buff *skb) {}
skb_ext_reset(struct sk_buff * skb)4317 static inline void skb_ext_reset(struct sk_buff *skb) {}
skb_ext_del(struct sk_buff * skb,int unused)4318 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
__skb_ext_copy(struct sk_buff * d,const struct sk_buff * s)4319 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)4320 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
skb_has_extensions(struct sk_buff * skb)4321 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4322 #endif /* CONFIG_SKB_EXTENSIONS */
4323
nf_reset_ct(struct sk_buff * skb)4324 static inline void nf_reset_ct(struct sk_buff *skb)
4325 {
4326 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4327 nf_conntrack_put(skb_nfct(skb));
4328 skb->_nfct = 0;
4329 #endif
4330 }
4331
nf_reset_trace(struct sk_buff * skb)4332 static inline void nf_reset_trace(struct sk_buff *skb)
4333 {
4334 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4335 skb->nf_trace = 0;
4336 #endif
4337 }
4338
ipvs_reset(struct sk_buff * skb)4339 static inline void ipvs_reset(struct sk_buff *skb)
4340 {
4341 #if IS_ENABLED(CONFIG_IP_VS)
4342 skb->ipvs_property = 0;
4343 #endif
4344 }
4345
4346 /* Note: This doesn't put any conntrack info in dst. */
__nf_copy(struct sk_buff * dst,const struct sk_buff * src,bool copy)4347 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4348 bool copy)
4349 {
4350 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4351 dst->_nfct = src->_nfct;
4352 nf_conntrack_get(skb_nfct(src));
4353 #endif
4354 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4355 if (copy)
4356 dst->nf_trace = src->nf_trace;
4357 #endif
4358 }
4359
nf_copy(struct sk_buff * dst,const struct sk_buff * src)4360 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4361 {
4362 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4363 nf_conntrack_put(skb_nfct(dst));
4364 #endif
4365 __nf_copy(dst, src, true);
4366 }
4367
4368 #ifdef CONFIG_NETWORK_SECMARK
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4369 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4370 {
4371 to->secmark = from->secmark;
4372 }
4373
skb_init_secmark(struct sk_buff * skb)4374 static inline void skb_init_secmark(struct sk_buff *skb)
4375 {
4376 skb->secmark = 0;
4377 }
4378 #else
skb_copy_secmark(struct sk_buff * to,const struct sk_buff * from)4379 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4380 { }
4381
skb_init_secmark(struct sk_buff * skb)4382 static inline void skb_init_secmark(struct sk_buff *skb)
4383 { }
4384 #endif
4385
secpath_exists(const struct sk_buff * skb)4386 static inline int secpath_exists(const struct sk_buff *skb)
4387 {
4388 #ifdef CONFIG_XFRM
4389 return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4390 #else
4391 return 0;
4392 #endif
4393 }
4394
skb_irq_freeable(const struct sk_buff * skb)4395 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4396 {
4397 return !skb->destructor &&
4398 !secpath_exists(skb) &&
4399 !skb_nfct(skb) &&
4400 !skb->_skb_refdst &&
4401 !skb_has_frag_list(skb);
4402 }
4403
skb_set_queue_mapping(struct sk_buff * skb,u16 queue_mapping)4404 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4405 {
4406 skb->queue_mapping = queue_mapping;
4407 }
4408
skb_get_queue_mapping(const struct sk_buff * skb)4409 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4410 {
4411 return skb->queue_mapping;
4412 }
4413
skb_copy_queue_mapping(struct sk_buff * to,const struct sk_buff * from)4414 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4415 {
4416 to->queue_mapping = from->queue_mapping;
4417 }
4418
skb_record_rx_queue(struct sk_buff * skb,u16 rx_queue)4419 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4420 {
4421 skb->queue_mapping = rx_queue + 1;
4422 }
4423
skb_get_rx_queue(const struct sk_buff * skb)4424 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4425 {
4426 return skb->queue_mapping - 1;
4427 }
4428
skb_rx_queue_recorded(const struct sk_buff * skb)4429 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4430 {
4431 return skb->queue_mapping != 0;
4432 }
4433
skb_set_dst_pending_confirm(struct sk_buff * skb,u32 val)4434 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4435 {
4436 skb->dst_pending_confirm = val;
4437 }
4438
skb_get_dst_pending_confirm(const struct sk_buff * skb)4439 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4440 {
4441 return skb->dst_pending_confirm != 0;
4442 }
4443
skb_sec_path(const struct sk_buff * skb)4444 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4445 {
4446 #ifdef CONFIG_XFRM
4447 return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4448 #else
4449 return NULL;
4450 #endif
4451 }
4452
4453 /* Keeps track of mac header offset relative to skb->head.
4454 * It is useful for TSO of Tunneling protocol. e.g. GRE.
4455 * For non-tunnel skb it points to skb_mac_header() and for
4456 * tunnel skb it points to outer mac header.
4457 * Keeps track of level of encapsulation of network headers.
4458 */
4459 struct skb_gso_cb {
4460 union {
4461 int mac_offset;
4462 int data_offset;
4463 };
4464 int encap_level;
4465 __wsum csum;
4466 __u16 csum_start;
4467 };
4468 #define SKB_GSO_CB_OFFSET 32
4469 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET))
4470
skb_tnl_header_len(const struct sk_buff * inner_skb)4471 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
4472 {
4473 return (skb_mac_header(inner_skb) - inner_skb->head) -
4474 SKB_GSO_CB(inner_skb)->mac_offset;
4475 }
4476
gso_pskb_expand_head(struct sk_buff * skb,int extra)4477 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
4478 {
4479 int new_headroom, headroom;
4480 int ret;
4481
4482 headroom = skb_headroom(skb);
4483 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
4484 if (ret)
4485 return ret;
4486
4487 new_headroom = skb_headroom(skb);
4488 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
4489 return 0;
4490 }
4491
gso_reset_checksum(struct sk_buff * skb,__wsum res)4492 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
4493 {
4494 /* Do not update partial checksums if remote checksum is enabled. */
4495 if (skb->remcsum_offload)
4496 return;
4497
4498 SKB_GSO_CB(skb)->csum = res;
4499 SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head;
4500 }
4501
4502 /* Compute the checksum for a gso segment. First compute the checksum value
4503 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
4504 * then add in skb->csum (checksum from csum_start to end of packet).
4505 * skb->csum and csum_start are then updated to reflect the checksum of the
4506 * resultant packet starting from the transport header-- the resultant checksum
4507 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
4508 * header.
4509 */
gso_make_checksum(struct sk_buff * skb,__wsum res)4510 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
4511 {
4512 unsigned char *csum_start = skb_transport_header(skb);
4513 int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start;
4514 __wsum partial = SKB_GSO_CB(skb)->csum;
4515
4516 SKB_GSO_CB(skb)->csum = res;
4517 SKB_GSO_CB(skb)->csum_start = csum_start - skb->head;
4518
4519 return csum_fold(csum_partial(csum_start, plen, partial));
4520 }
4521
skb_is_gso(const struct sk_buff * skb)4522 static inline bool skb_is_gso(const struct sk_buff *skb)
4523 {
4524 return skb_shinfo(skb)->gso_size;
4525 }
4526
4527 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_v6(const struct sk_buff * skb)4528 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4529 {
4530 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4531 }
4532
4533 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_sctp(const struct sk_buff * skb)4534 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4535 {
4536 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4537 }
4538
4539 /* Note: Should be called only if skb_is_gso(skb) is true */
skb_is_gso_tcp(const struct sk_buff * skb)4540 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4541 {
4542 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
4543 }
4544
skb_gso_reset(struct sk_buff * skb)4545 static inline void skb_gso_reset(struct sk_buff *skb)
4546 {
4547 skb_shinfo(skb)->gso_size = 0;
4548 skb_shinfo(skb)->gso_segs = 0;
4549 skb_shinfo(skb)->gso_type = 0;
4550 }
4551
skb_increase_gso_size(struct skb_shared_info * shinfo,u16 increment)4552 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
4553 u16 increment)
4554 {
4555 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4556 return;
4557 shinfo->gso_size += increment;
4558 }
4559
skb_decrease_gso_size(struct skb_shared_info * shinfo,u16 decrement)4560 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
4561 u16 decrement)
4562 {
4563 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4564 return;
4565 shinfo->gso_size -= decrement;
4566 }
4567
4568 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
4569
skb_warn_if_lro(const struct sk_buff * skb)4570 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
4571 {
4572 /* LRO sets gso_size but not gso_type, whereas if GSO is really
4573 * wanted then gso_type will be set. */
4574 const struct skb_shared_info *shinfo = skb_shinfo(skb);
4575
4576 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
4577 unlikely(shinfo->gso_type == 0)) {
4578 __skb_warn_lro_forwarding(skb);
4579 return true;
4580 }
4581 return false;
4582 }
4583
skb_forward_csum(struct sk_buff * skb)4584 static inline void skb_forward_csum(struct sk_buff *skb)
4585 {
4586 /* Unfortunately we don't support this one. Any brave souls? */
4587 if (skb->ip_summed == CHECKSUM_COMPLETE)
4588 skb->ip_summed = CHECKSUM_NONE;
4589 }
4590
4591 /**
4592 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4593 * @skb: skb to check
4594 *
4595 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4596 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4597 * use this helper, to document places where we make this assertion.
4598 */
skb_checksum_none_assert(const struct sk_buff * skb)4599 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
4600 {
4601 #ifdef DEBUG
4602 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
4603 #endif
4604 }
4605
4606 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
4607
4608 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
4609 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
4610 unsigned int transport_len,
4611 __sum16(*skb_chkf)(struct sk_buff *skb));
4612
4613 /**
4614 * skb_head_is_locked - Determine if the skb->head is locked down
4615 * @skb: skb to check
4616 *
4617 * The head on skbs build around a head frag can be removed if they are
4618 * not cloned. This function returns true if the skb head is locked down
4619 * due to either being allocated via kmalloc, or by being a clone with
4620 * multiple references to the head.
4621 */
skb_head_is_locked(const struct sk_buff * skb)4622 static inline bool skb_head_is_locked(const struct sk_buff *skb)
4623 {
4624 return !skb->head_frag || skb_cloned(skb);
4625 }
4626
4627 /* Local Checksum Offload.
4628 * Compute outer checksum based on the assumption that the
4629 * inner checksum will be offloaded later.
4630 * See Documentation/networking/checksum-offloads.rst for
4631 * explanation of how this works.
4632 * Fill in outer checksum adjustment (e.g. with sum of outer
4633 * pseudo-header) before calling.
4634 * Also ensure that inner checksum is in linear data area.
4635 */
lco_csum(struct sk_buff * skb)4636 static inline __wsum lco_csum(struct sk_buff *skb)
4637 {
4638 unsigned char *csum_start = skb_checksum_start(skb);
4639 unsigned char *l4_hdr = skb_transport_header(skb);
4640 __wsum partial;
4641
4642 /* Start with complement of inner checksum adjustment */
4643 partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
4644 skb->csum_offset));
4645
4646 /* Add in checksum of our headers (incl. outer checksum
4647 * adjustment filled in by caller) and return result.
4648 */
4649 return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
4650 }
4651
skb_is_redirected(const struct sk_buff * skb)4652 static inline bool skb_is_redirected(const struct sk_buff *skb)
4653 {
4654 #ifdef CONFIG_NET_REDIRECT
4655 return skb->redirected;
4656 #else
4657 return false;
4658 #endif
4659 }
4660
skb_set_redirected(struct sk_buff * skb,bool from_ingress)4661 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
4662 {
4663 #ifdef CONFIG_NET_REDIRECT
4664 skb->redirected = 1;
4665 skb->from_ingress = from_ingress;
4666 if (skb->from_ingress)
4667 skb->tstamp = 0;
4668 #endif
4669 }
4670
skb_reset_redirect(struct sk_buff * skb)4671 static inline void skb_reset_redirect(struct sk_buff *skb)
4672 {
4673 #ifdef CONFIG_NET_REDIRECT
4674 skb->redirected = 0;
4675 #endif
4676 }
4677
skb_csum_is_sctp(struct sk_buff * skb)4678 static inline bool skb_csum_is_sctp(struct sk_buff *skb)
4679 {
4680 return skb->csum_not_inet;
4681 }
4682
skb_set_kcov_handle(struct sk_buff * skb,const u64 kcov_handle)4683 static inline void skb_set_kcov_handle(struct sk_buff *skb,
4684 const u64 kcov_handle)
4685 {
4686 #ifdef CONFIG_KCOV
4687 skb->kcov_handle = kcov_handle;
4688 #endif
4689 }
4690
skb_get_kcov_handle(struct sk_buff * skb)4691 static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
4692 {
4693 #ifdef CONFIG_KCOV
4694 return skb->kcov_handle;
4695 #else
4696 return 0;
4697 #endif
4698 }
4699
4700 #endif /* __KERNEL__ */
4701 #endif /* _LINUX_SKBUFF_H */
4702