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