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/cache.h> 18 #include <linux/rbtree.h> 19 #include <linux/socket.h> 20 #include <linux/refcount.h> 21 22 #include <linux/atomic.h> 23 #include <asm/types.h> 24 #include <linux/spinlock.h> 25 #include <linux/net.h> 26 #include <linux/textsearch.h> 27 #include <net/checksum.h> 28 #include <linux/rcupdate.h> 29 #include <linux/hrtimer.h> 30 #include <linux/dma-mapping.h> 31 #include <linux/netdev_features.h> 32 #include <linux/sched.h> 33 #include <linux/sched/clock.h> 34 #include <net/flow_dissector.h> 35 #include <linux/splice.h> 36 #include <linux/in6.h> 37 #include <linux/if_packet.h> 38 #include <net/flow.h> 39 40 /* The interface for checksum offload between the stack and networking drivers 41 * is as follows... 42 * 43 * A. IP checksum related features 44 * 45 * Drivers advertise checksum offload capabilities in the features of a device. 46 * From the stack's point of view these are capabilities offered by the driver, 47 * a driver typically only advertises features that it is capable of offloading 48 * to its device. 49 * 50 * The checksum related features are: 51 * 52 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one 53 * IP (one's complement) checksum for any combination 54 * of protocols or protocol layering. The checksum is 55 * computed and set in a packet per the CHECKSUM_PARTIAL 56 * interface (see below). 57 * 58 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain 59 * TCP or UDP packets over IPv4. These are specifically 60 * unencapsulated packets of the form IPv4|TCP or 61 * IPv4|UDP where the Protocol field in the IPv4 header 62 * is TCP or UDP. The IPv4 header may contain IP options 63 * This feature cannot be set in features for a device 64 * with NETIF_F_HW_CSUM also set. This feature is being 65 * DEPRECATED (see below). 66 * 67 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain 68 * TCP or UDP packets over IPv6. These are specifically 69 * unencapsulated packets of the form IPv6|TCP or 70 * IPv4|UDP where the Next Header field in the IPv6 71 * header is either TCP or UDP. IPv6 extension headers 72 * are not supported with this feature. This feature 73 * cannot be set in features for a device with 74 * NETIF_F_HW_CSUM also set. This feature is being 75 * DEPRECATED (see below). 76 * 77 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload. 78 * This flag is used only used to disable the RX checksum 79 * feature for a device. The stack will accept receive 80 * checksum indication in packets received on a device 81 * regardless of whether NETIF_F_RXCSUM is set. 82 * 83 * B. Checksumming of received packets by device. Indication of checksum 84 * verification is in set skb->ip_summed. Possible values are: 85 * 86 * CHECKSUM_NONE: 87 * 88 * Device did not checksum this packet e.g. due to lack of capabilities. 89 * The packet contains full (though not verified) checksum in packet but 90 * not in skb->csum. Thus, skb->csum is undefined in this case. 91 * 92 * CHECKSUM_UNNECESSARY: 93 * 94 * The hardware you're dealing with doesn't calculate the full checksum 95 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums 96 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY 97 * if their checksums are okay. skb->csum is still undefined in this case 98 * though. A driver or device must never modify the checksum field in the 99 * packet even if checksum is verified. 100 * 101 * CHECKSUM_UNNECESSARY is applicable to following protocols: 102 * TCP: IPv6 and IPv4. 103 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a 104 * zero UDP checksum for either IPv4 or IPv6, the networking stack 105 * may perform further validation in this case. 106 * GRE: only if the checksum is present in the header. 107 * SCTP: indicates the CRC in SCTP header has been validated. 108 * FCOE: indicates the CRC in FC frame has been validated. 109 * 110 * skb->csum_level indicates the number of consecutive checksums found in 111 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY. 112 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet 113 * and a device is able to verify the checksums for UDP (possibly zero), 114 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to 115 * two. If the device were only able to verify the UDP checksum and not 116 * GRE, either because it doesn't support GRE checksum of because GRE 117 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is 118 * not considered in this case). 119 * 120 * CHECKSUM_COMPLETE: 121 * 122 * This is the most generic way. The device supplied checksum of the _whole_ 123 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the 124 * hardware doesn't need to parse L3/L4 headers to implement this. 125 * 126 * Notes: 127 * - Even if device supports only some protocols, but is able to produce 128 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 129 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols. 130 * 131 * CHECKSUM_PARTIAL: 132 * 133 * A checksum is set up to be offloaded to a device as described in the 134 * output description for CHECKSUM_PARTIAL. This may occur on a packet 135 * received directly from another Linux OS, e.g., a virtualized Linux kernel 136 * on the same host, or it may be set in the input path in GRO or remote 137 * checksum offload. For the purposes of checksum verification, the checksum 138 * referred to by skb->csum_start + skb->csum_offset and any preceding 139 * checksums in the packet are considered verified. Any checksums in the 140 * packet that are after the checksum being offloaded are not considered to 141 * be verified. 142 * 143 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload 144 * in the skb->ip_summed for a packet. Values are: 145 * 146 * CHECKSUM_PARTIAL: 147 * 148 * The driver is required to checksum the packet as seen by hard_start_xmit() 149 * from skb->csum_start up to the end, and to record/write the checksum at 150 * offset skb->csum_start + skb->csum_offset. A driver may verify that the 151 * csum_start and csum_offset values are valid values given the length and 152 * offset of the packet, however they should not attempt to validate that the 153 * checksum refers to a legitimate transport layer checksum-- it is the 154 * purview of the stack to validate that csum_start and csum_offset are set 155 * correctly. 156 * 157 * When the stack requests checksum offload for a packet, the driver MUST 158 * ensure that the checksum is set correctly. A driver can either offload the 159 * checksum calculation to the device, or call skb_checksum_help (in the case 160 * that the device does not support offload for a particular checksum). 161 * 162 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of 163 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate 164 * checksum offload capability. 165 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based 166 * on network device checksumming capabilities: if a packet does not match 167 * them, skb_checksum_help or skb_crc32c_help (depending on the value of 168 * csum_not_inet, see item D.) is called to resolve the checksum. 169 * 170 * CHECKSUM_NONE: 171 * 172 * The skb was already checksummed by the protocol, or a checksum is not 173 * required. 174 * 175 * CHECKSUM_UNNECESSARY: 176 * 177 * This has the same meaning on as CHECKSUM_NONE for checksum offload on 178 * output. 179 * 180 * CHECKSUM_COMPLETE: 181 * Not used in checksum output. If a driver observes a packet with this value 182 * set in skbuff, if should treat as CHECKSUM_NONE being set. 183 * 184 * D. Non-IP checksum (CRC) offloads 185 * 186 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of 187 * offloading the SCTP CRC in a packet. To perform this offload the stack 188 * will set set csum_start and csum_offset accordingly, set ip_summed to 189 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in 190 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c. 191 * A driver that supports both IP checksum offload and SCTP CRC32c offload 192 * must verify which offload is configured for a packet by testing the 193 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve 194 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1. 195 * 196 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of 197 * offloading the FCOE CRC in a packet. To perform this offload the stack 198 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset 199 * accordingly. Note the there is no indication in the skbuff that the 200 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports 201 * both IP checksum offload and FCOE CRC offload must verify which offload 202 * is configured for a packet presumably by inspecting packet headers. 203 * 204 * E. Checksumming on output with GSO. 205 * 206 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload 207 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the 208 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as 209 * part of the GSO operation is implied. If a checksum is being offloaded 210 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset 211 * are set to refer to the outermost checksum being offload (two offloaded 212 * checksums are possible with UDP encapsulation). 213 */ 214 215 /* Don't change this without changing skb_csum_unnecessary! */ 216 #define CHECKSUM_NONE 0 217 #define CHECKSUM_UNNECESSARY 1 218 #define CHECKSUM_COMPLETE 2 219 #define CHECKSUM_PARTIAL 3 220 221 /* Maximum value in skb->csum_level */ 222 #define SKB_MAX_CSUM_LEVEL 3 223 224 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) 225 #define SKB_WITH_OVERHEAD(X) \ 226 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 227 #define SKB_MAX_ORDER(X, ORDER) \ 228 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 229 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 230 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 231 232 /* return minimum truesize of one skb containing X bytes of data */ 233 #define SKB_TRUESIZE(X) ((X) + \ 234 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 235 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 236 237 struct net_device; 238 struct scatterlist; 239 struct pipe_inode_info; 240 struct iov_iter; 241 struct napi_struct; 242 struct bpf_prog; 243 union bpf_attr; 244 struct skb_ext; 245 246 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 247 struct nf_conntrack { 248 atomic_t use; 249 }; 250 #endif 251 252 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 253 struct nf_bridge_info { 254 enum { 255 BRNF_PROTO_UNCHANGED, 256 BRNF_PROTO_8021Q, 257 BRNF_PROTO_PPPOE 258 } orig_proto:8; 259 u8 pkt_otherhost:1; 260 u8 in_prerouting:1; 261 u8 bridged_dnat:1; 262 __u16 frag_max_size; 263 struct net_device *physindev; 264 265 /* always valid & non-NULL from FORWARD on, for physdev match */ 266 struct net_device *physoutdev; 267 union { 268 /* prerouting: detect dnat in orig/reply direction */ 269 __be32 ipv4_daddr; 270 struct in6_addr ipv6_daddr; 271 272 /* after prerouting + nat detected: store original source 273 * mac since neigh resolution overwrites it, only used while 274 * skb is out in neigh layer. 275 */ 276 char neigh_header[8]; 277 }; 278 }; 279 #endif 280 281 struct sk_buff_head { 282 /* These two members must be first. */ 283 struct sk_buff *next; 284 struct sk_buff *prev; 285 286 __u32 qlen; 287 spinlock_t lock; 288 }; 289 290 struct sk_buff; 291 292 /* To allow 64K frame to be packed as single skb without frag_list we 293 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for 294 * buffers which do not start on a page boundary. 295 * 296 * Since GRO uses frags we allocate at least 16 regardless of page 297 * size. 298 */ 299 #if (65536/PAGE_SIZE + 1) < 16 300 #define MAX_SKB_FRAGS 16UL 301 #else 302 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) 303 #endif 304 extern int sysctl_max_skb_frags; 305 306 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to 307 * segment using its current segmentation instead. 308 */ 309 #define GSO_BY_FRAGS 0xFFFF 310 311 typedef struct skb_frag_struct skb_frag_t; 312 313 struct skb_frag_struct { 314 struct { 315 struct page *p; 316 } page; 317 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 318 __u32 page_offset; 319 __u32 size; 320 #else 321 __u16 page_offset; 322 __u16 size; 323 #endif 324 }; 325 326 /** 327 * skb_frag_size - Returns the size of a skb fragment 328 * @frag: skb fragment 329 */ 330 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 331 { 332 return frag->size; 333 } 334 335 /** 336 * skb_frag_size_set - Sets the size of a skb fragment 337 * @frag: skb fragment 338 * @size: size of fragment 339 */ 340 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 341 { 342 frag->size = size; 343 } 344 345 /** 346 * skb_frag_size_add - Incrementes the size of a skb fragment by %delta 347 * @frag: skb fragment 348 * @delta: value to add 349 */ 350 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 351 { 352 frag->size += delta; 353 } 354 355 /** 356 * skb_frag_size_sub - Decrements the size of a skb fragment by %delta 357 * @frag: skb fragment 358 * @delta: value to subtract 359 */ 360 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 361 { 362 frag->size -= delta; 363 } 364 365 /** 366 * skb_frag_must_loop - Test if %p is a high memory page 367 * @p: fragment's page 368 */ 369 static inline bool skb_frag_must_loop(struct page *p) 370 { 371 #if defined(CONFIG_HIGHMEM) 372 if (PageHighMem(p)) 373 return true; 374 #endif 375 return false; 376 } 377 378 /** 379 * skb_frag_foreach_page - loop over pages in a fragment 380 * 381 * @f: skb frag to operate on 382 * @f_off: offset from start of f->page.p 383 * @f_len: length from f_off to loop over 384 * @p: (temp var) current page 385 * @p_off: (temp var) offset from start of current page, 386 * non-zero only on first page. 387 * @p_len: (temp var) length in current page, 388 * < PAGE_SIZE only on first and last page. 389 * @copied: (temp var) length so far, excluding current p_len. 390 * 391 * A fragment can hold a compound page, in which case per-page 392 * operations, notably kmap_atomic, must be called for each 393 * regular page. 394 */ 395 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \ 396 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \ 397 p_off = (f_off) & (PAGE_SIZE - 1), \ 398 p_len = skb_frag_must_loop(p) ? \ 399 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \ 400 copied = 0; \ 401 copied < f_len; \ 402 copied += p_len, p++, p_off = 0, \ 403 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \ 404 405 #define HAVE_HW_TIME_STAMP 406 407 /** 408 * struct skb_shared_hwtstamps - hardware time stamps 409 * @hwtstamp: hardware time stamp transformed into duration 410 * since arbitrary point in time 411 * 412 * Software time stamps generated by ktime_get_real() are stored in 413 * skb->tstamp. 414 * 415 * hwtstamps can only be compared against other hwtstamps from 416 * the same device. 417 * 418 * This structure is attached to packets as part of the 419 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 420 */ 421 struct skb_shared_hwtstamps { 422 ktime_t hwtstamp; 423 }; 424 425 /* Definitions for tx_flags in struct skb_shared_info */ 426 enum { 427 /* generate hardware time stamp */ 428 SKBTX_HW_TSTAMP = 1 << 0, 429 430 /* generate software time stamp when queueing packet to NIC */ 431 SKBTX_SW_TSTAMP = 1 << 1, 432 433 /* device driver is going to provide hardware time stamp */ 434 SKBTX_IN_PROGRESS = 1 << 2, 435 436 /* device driver supports TX zero-copy buffers */ 437 SKBTX_DEV_ZEROCOPY = 1 << 3, 438 439 /* generate wifi status information (where possible) */ 440 SKBTX_WIFI_STATUS = 1 << 4, 441 442 /* This indicates at least one fragment might be overwritten 443 * (as in vmsplice(), sendfile() ...) 444 * If we need to compute a TX checksum, we'll need to copy 445 * all frags to avoid possible bad checksum 446 */ 447 SKBTX_SHARED_FRAG = 1 << 5, 448 449 /* generate software time stamp when entering packet scheduling */ 450 SKBTX_SCHED_TSTAMP = 1 << 6, 451 }; 452 453 #define SKBTX_ZEROCOPY_FRAG (SKBTX_DEV_ZEROCOPY | SKBTX_SHARED_FRAG) 454 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ 455 SKBTX_SCHED_TSTAMP) 456 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) 457 458 /* 459 * The callback notifies userspace to release buffers when skb DMA is done in 460 * lower device, the skb last reference should be 0 when calling this. 461 * The zerocopy_success argument is true if zero copy transmit occurred, 462 * false on data copy or out of memory error caused by data copy attempt. 463 * The ctx field is used to track device context. 464 * The desc field is used to track userspace buffer index. 465 */ 466 struct ubuf_info { 467 void (*callback)(struct ubuf_info *, bool zerocopy_success); 468 union { 469 struct { 470 unsigned long desc; 471 void *ctx; 472 }; 473 struct { 474 u32 id; 475 u16 len; 476 u16 zerocopy:1; 477 u32 bytelen; 478 }; 479 }; 480 refcount_t refcnt; 481 482 struct mmpin { 483 struct user_struct *user; 484 unsigned int num_pg; 485 } mmp; 486 }; 487 488 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg)) 489 490 int mm_account_pinned_pages(struct mmpin *mmp, size_t size); 491 void mm_unaccount_pinned_pages(struct mmpin *mmp); 492 493 struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size); 494 struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size, 495 struct ubuf_info *uarg); 496 497 static inline void sock_zerocopy_get(struct ubuf_info *uarg) 498 { 499 refcount_inc(&uarg->refcnt); 500 } 501 502 void sock_zerocopy_put(struct ubuf_info *uarg); 503 void sock_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); 504 505 void sock_zerocopy_callback(struct ubuf_info *uarg, bool success); 506 507 int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len); 508 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, 509 struct msghdr *msg, int len, 510 struct ubuf_info *uarg); 511 512 /* This data is invariant across clones and lives at 513 * the end of the header data, ie. at skb->end. 514 */ 515 struct skb_shared_info { 516 __u8 __unused; 517 __u8 meta_len; 518 __u8 nr_frags; 519 __u8 tx_flags; 520 unsigned short gso_size; 521 /* Warning: this field is not always filled in (UFO)! */ 522 unsigned short gso_segs; 523 struct sk_buff *frag_list; 524 struct skb_shared_hwtstamps hwtstamps; 525 unsigned int gso_type; 526 u32 tskey; 527 528 /* 529 * Warning : all fields before dataref are cleared in __alloc_skb() 530 */ 531 atomic_t dataref; 532 533 /* Intermediate layers must ensure that destructor_arg 534 * remains valid until skb destructor */ 535 void * destructor_arg; 536 537 /* must be last field, see pskb_expand_head() */ 538 skb_frag_t frags[MAX_SKB_FRAGS]; 539 }; 540 541 /* We divide dataref into two halves. The higher 16 bits hold references 542 * to the payload part of skb->data. The lower 16 bits hold references to 543 * the entire skb->data. A clone of a headerless skb holds the length of 544 * the header in skb->hdr_len. 545 * 546 * All users must obey the rule that the skb->data reference count must be 547 * greater than or equal to the payload reference count. 548 * 549 * Holding a reference to the payload part means that the user does not 550 * care about modifications to the header part of skb->data. 551 */ 552 #define SKB_DATAREF_SHIFT 16 553 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 554 555 556 enum { 557 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ 558 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ 559 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ 560 }; 561 562 enum { 563 SKB_GSO_TCPV4 = 1 << 0, 564 565 /* This indicates the skb is from an untrusted source. */ 566 SKB_GSO_DODGY = 1 << 1, 567 568 /* This indicates the tcp segment has CWR set. */ 569 SKB_GSO_TCP_ECN = 1 << 2, 570 571 SKB_GSO_TCP_FIXEDID = 1 << 3, 572 573 SKB_GSO_TCPV6 = 1 << 4, 574 575 SKB_GSO_FCOE = 1 << 5, 576 577 SKB_GSO_GRE = 1 << 6, 578 579 SKB_GSO_GRE_CSUM = 1 << 7, 580 581 SKB_GSO_IPXIP4 = 1 << 8, 582 583 SKB_GSO_IPXIP6 = 1 << 9, 584 585 SKB_GSO_UDP_TUNNEL = 1 << 10, 586 587 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, 588 589 SKB_GSO_PARTIAL = 1 << 12, 590 591 SKB_GSO_TUNNEL_REMCSUM = 1 << 13, 592 593 SKB_GSO_SCTP = 1 << 14, 594 595 SKB_GSO_ESP = 1 << 15, 596 597 SKB_GSO_UDP = 1 << 16, 598 599 SKB_GSO_UDP_L4 = 1 << 17, 600 }; 601 602 #if BITS_PER_LONG > 32 603 #define NET_SKBUFF_DATA_USES_OFFSET 1 604 #endif 605 606 #ifdef NET_SKBUFF_DATA_USES_OFFSET 607 typedef unsigned int sk_buff_data_t; 608 #else 609 typedef unsigned char *sk_buff_data_t; 610 #endif 611 612 /** 613 * struct sk_buff - socket buffer 614 * @next: Next buffer in list 615 * @prev: Previous buffer in list 616 * @tstamp: Time we arrived/left 617 * @rbnode: RB tree node, alternative to next/prev for netem/tcp 618 * @sk: Socket we are owned by 619 * @dev: Device we arrived on/are leaving by 620 * @cb: Control buffer. Free for use by every layer. Put private vars here 621 * @_skb_refdst: destination entry (with norefcount bit) 622 * @sp: the security path, used for xfrm 623 * @len: Length of actual data 624 * @data_len: Data length 625 * @mac_len: Length of link layer header 626 * @hdr_len: writable header length of cloned skb 627 * @csum: Checksum (must include start/offset pair) 628 * @csum_start: Offset from skb->head where checksumming should start 629 * @csum_offset: Offset from csum_start where checksum should be stored 630 * @priority: Packet queueing priority 631 * @ignore_df: allow local fragmentation 632 * @cloned: Head may be cloned (check refcnt to be sure) 633 * @ip_summed: Driver fed us an IP checksum 634 * @nohdr: Payload reference only, must not modify header 635 * @pkt_type: Packet class 636 * @fclone: skbuff clone status 637 * @ipvs_property: skbuff is owned by ipvs 638 * @offload_fwd_mark: Packet was L2-forwarded in hardware 639 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware 640 * @tc_skip_classify: do not classify packet. set by IFB device 641 * @tc_at_ingress: used within tc_classify to distinguish in/egress 642 * @tc_redirected: packet was redirected by a tc action 643 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect 644 * @peeked: this packet has been seen already, so stats have been 645 * done for it, don't do them again 646 * @nf_trace: netfilter packet trace flag 647 * @protocol: Packet protocol from driver 648 * @destructor: Destruct function 649 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue) 650 * @_nfct: Associated connection, if any (with nfctinfo bits) 651 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 652 * @skb_iif: ifindex of device we arrived on 653 * @tc_index: Traffic control index 654 * @hash: the packet hash 655 * @queue_mapping: Queue mapping for multiqueue devices 656 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves 657 * @active_extensions: active extensions (skb_ext_id types) 658 * @ndisc_nodetype: router type (from link layer) 659 * @ooo_okay: allow the mapping of a socket to a queue to be changed 660 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport 661 * ports. 662 * @sw_hash: indicates hash was computed in software stack 663 * @wifi_acked_valid: wifi_acked was set 664 * @wifi_acked: whether frame was acked on wifi or not 665 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 666 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL 667 * @dst_pending_confirm: need to confirm neighbour 668 * @decrypted: Decrypted SKB 669 * @napi_id: id of the NAPI struct this skb came from 670 * @secmark: security marking 671 * @mark: Generic packet mark 672 * @vlan_proto: vlan encapsulation protocol 673 * @vlan_tci: vlan tag control information 674 * @inner_protocol: Protocol (encapsulation) 675 * @inner_transport_header: Inner transport layer header (encapsulation) 676 * @inner_network_header: Network layer header (encapsulation) 677 * @inner_mac_header: Link layer header (encapsulation) 678 * @transport_header: Transport layer header 679 * @network_header: Network layer header 680 * @mac_header: Link layer header 681 * @tail: Tail pointer 682 * @end: End pointer 683 * @head: Head of buffer 684 * @data: Data head pointer 685 * @truesize: Buffer size 686 * @users: User count - see {datagram,tcp}.c 687 * @extensions: allocated extensions, valid if active_extensions is nonzero 688 */ 689 690 struct sk_buff { 691 union { 692 struct { 693 /* These two members must be first. */ 694 struct sk_buff *next; 695 struct sk_buff *prev; 696 697 union { 698 struct net_device *dev; 699 /* Some protocols might use this space to store information, 700 * while device pointer would be NULL. 701 * UDP receive path is one user. 702 */ 703 unsigned long dev_scratch; 704 }; 705 }; 706 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */ 707 struct list_head list; 708 }; 709 710 union { 711 struct sock *sk; 712 int ip_defrag_offset; 713 }; 714 715 union { 716 ktime_t tstamp; 717 u64 skb_mstamp_ns; /* earliest departure time */ 718 }; 719 /* 720 * This is the control buffer. It is free to use for every 721 * layer. Please put your private variables there. If you 722 * want to keep them across layers you have to do a skb_clone() 723 * first. This is owned by whoever has the skb queued ATM. 724 */ 725 char cb[48] __aligned(8); 726 727 union { 728 struct { 729 unsigned long _skb_refdst; 730 void (*destructor)(struct sk_buff *skb); 731 }; 732 struct list_head tcp_tsorted_anchor; 733 }; 734 735 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 736 unsigned long _nfct; 737 #endif 738 unsigned int len, 739 data_len; 740 __u16 mac_len, 741 hdr_len; 742 743 /* Following fields are _not_ copied in __copy_skb_header() 744 * Note that queue_mapping is here mostly to fill a hole. 745 */ 746 __u16 queue_mapping; 747 748 /* if you move cloned around you also must adapt those constants */ 749 #ifdef __BIG_ENDIAN_BITFIELD 750 #define CLONED_MASK (1 << 7) 751 #else 752 #define CLONED_MASK 1 753 #endif 754 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset) 755 756 __u8 __cloned_offset[0]; 757 __u8 cloned:1, 758 nohdr:1, 759 fclone:2, 760 peeked:1, 761 head_frag:1, 762 pfmemalloc:1; 763 #ifdef CONFIG_SKB_EXTENSIONS 764 __u8 active_extensions; 765 #endif 766 /* fields enclosed in headers_start/headers_end are copied 767 * using a single memcpy() in __copy_skb_header() 768 */ 769 /* private: */ 770 __u32 headers_start[0]; 771 /* public: */ 772 773 /* if you move pkt_type around you also must adapt those constants */ 774 #ifdef __BIG_ENDIAN_BITFIELD 775 #define PKT_TYPE_MAX (7 << 5) 776 #else 777 #define PKT_TYPE_MAX 7 778 #endif 779 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset) 780 781 __u8 __pkt_type_offset[0]; 782 __u8 pkt_type:3; 783 __u8 ignore_df:1; 784 __u8 nf_trace:1; 785 __u8 ip_summed:2; 786 __u8 ooo_okay:1; 787 788 __u8 l4_hash:1; 789 __u8 sw_hash:1; 790 __u8 wifi_acked_valid:1; 791 __u8 wifi_acked:1; 792 __u8 no_fcs:1; 793 /* Indicates the inner headers are valid in the skbuff. */ 794 __u8 encapsulation:1; 795 __u8 encap_hdr_csum:1; 796 __u8 csum_valid:1; 797 798 #ifdef __BIG_ENDIAN_BITFIELD 799 #define PKT_VLAN_PRESENT_BIT 7 800 #else 801 #define PKT_VLAN_PRESENT_BIT 0 802 #endif 803 #define PKT_VLAN_PRESENT_OFFSET() offsetof(struct sk_buff, __pkt_vlan_present_offset) 804 __u8 __pkt_vlan_present_offset[0]; 805 __u8 vlan_present:1; 806 __u8 csum_complete_sw:1; 807 __u8 csum_level:2; 808 __u8 csum_not_inet:1; 809 __u8 dst_pending_confirm:1; 810 #ifdef CONFIG_IPV6_NDISC_NODETYPE 811 __u8 ndisc_nodetype:2; 812 #endif 813 814 __u8 ipvs_property:1; 815 __u8 inner_protocol_type:1; 816 __u8 remcsum_offload:1; 817 #ifdef CONFIG_NET_SWITCHDEV 818 __u8 offload_fwd_mark:1; 819 __u8 offload_l3_fwd_mark:1; 820 #endif 821 #ifdef CONFIG_NET_CLS_ACT 822 __u8 tc_skip_classify:1; 823 __u8 tc_at_ingress:1; 824 __u8 tc_redirected:1; 825 __u8 tc_from_ingress:1; 826 #endif 827 #ifdef CONFIG_TLS_DEVICE 828 __u8 decrypted:1; 829 #endif 830 831 #ifdef CONFIG_NET_SCHED 832 __u16 tc_index; /* traffic control index */ 833 #endif 834 835 union { 836 __wsum csum; 837 struct { 838 __u16 csum_start; 839 __u16 csum_offset; 840 }; 841 }; 842 __u32 priority; 843 int skb_iif; 844 __u32 hash; 845 __be16 vlan_proto; 846 __u16 vlan_tci; 847 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS) 848 union { 849 unsigned int napi_id; 850 unsigned int sender_cpu; 851 }; 852 #endif 853 #ifdef CONFIG_NETWORK_SECMARK 854 __u32 secmark; 855 #endif 856 857 union { 858 __u32 mark; 859 __u32 reserved_tailroom; 860 }; 861 862 union { 863 __be16 inner_protocol; 864 __u8 inner_ipproto; 865 }; 866 867 __u16 inner_transport_header; 868 __u16 inner_network_header; 869 __u16 inner_mac_header; 870 871 __be16 protocol; 872 __u16 transport_header; 873 __u16 network_header; 874 __u16 mac_header; 875 876 /* private: */ 877 __u32 headers_end[0]; 878 /* public: */ 879 880 /* These elements must be at the end, see alloc_skb() for details. */ 881 sk_buff_data_t tail; 882 sk_buff_data_t end; 883 unsigned char *head, 884 *data; 885 unsigned int truesize; 886 refcount_t users; 887 888 #ifdef CONFIG_SKB_EXTENSIONS 889 /* only useable after checking ->active_extensions != 0 */ 890 struct skb_ext *extensions; 891 #endif 892 }; 893 894 #ifdef __KERNEL__ 895 /* 896 * Handling routines are only of interest to the kernel 897 */ 898 899 #define SKB_ALLOC_FCLONE 0x01 900 #define SKB_ALLOC_RX 0x02 901 #define SKB_ALLOC_NAPI 0x04 902 903 /** 904 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves 905 * @skb: buffer 906 */ 907 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 908 { 909 return unlikely(skb->pfmemalloc); 910 } 911 912 /* 913 * skb might have a dst pointer attached, refcounted or not. 914 * _skb_refdst low order bit is set if refcount was _not_ taken 915 */ 916 #define SKB_DST_NOREF 1UL 917 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 918 919 #define SKB_NFCT_PTRMASK ~(7UL) 920 /** 921 * skb_dst - returns skb dst_entry 922 * @skb: buffer 923 * 924 * Returns skb dst_entry, regardless of reference taken or not. 925 */ 926 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 927 { 928 /* If refdst was not refcounted, check we still are in a 929 * rcu_read_lock section 930 */ 931 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 932 !rcu_read_lock_held() && 933 !rcu_read_lock_bh_held()); 934 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 935 } 936 937 /** 938 * skb_dst_set - sets skb dst 939 * @skb: buffer 940 * @dst: dst entry 941 * 942 * Sets skb dst, assuming a reference was taken on dst and should 943 * be released by skb_dst_drop() 944 */ 945 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 946 { 947 skb->_skb_refdst = (unsigned long)dst; 948 } 949 950 /** 951 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 952 * @skb: buffer 953 * @dst: dst entry 954 * 955 * Sets skb dst, assuming a reference was not taken on dst. 956 * If dst entry is cached, we do not take reference and dst_release 957 * will be avoided by refdst_drop. If dst entry is not cached, we take 958 * reference, so that last dst_release can destroy the dst immediately. 959 */ 960 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 961 { 962 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 963 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 964 } 965 966 /** 967 * skb_dst_is_noref - Test if skb dst isn't refcounted 968 * @skb: buffer 969 */ 970 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 971 { 972 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 973 } 974 975 /** 976 * skb_rtable - Returns the skb &rtable 977 * @skb: buffer 978 */ 979 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 980 { 981 return (struct rtable *)skb_dst(skb); 982 } 983 984 /* For mangling skb->pkt_type from user space side from applications 985 * such as nft, tc, etc, we only allow a conservative subset of 986 * possible pkt_types to be set. 987 */ 988 static inline bool skb_pkt_type_ok(u32 ptype) 989 { 990 return ptype <= PACKET_OTHERHOST; 991 } 992 993 /** 994 * skb_napi_id - Returns the skb's NAPI id 995 * @skb: buffer 996 */ 997 static inline unsigned int skb_napi_id(const struct sk_buff *skb) 998 { 999 #ifdef CONFIG_NET_RX_BUSY_POLL 1000 return skb->napi_id; 1001 #else 1002 return 0; 1003 #endif 1004 } 1005 1006 /** 1007 * skb_unref - decrement the skb's reference count 1008 * @skb: buffer 1009 * 1010 * Returns true if we can free the skb. 1011 */ 1012 static inline bool skb_unref(struct sk_buff *skb) 1013 { 1014 if (unlikely(!skb)) 1015 return false; 1016 if (likely(refcount_read(&skb->users) == 1)) 1017 smp_rmb(); 1018 else if (likely(!refcount_dec_and_test(&skb->users))) 1019 return false; 1020 1021 return true; 1022 } 1023 1024 void skb_release_head_state(struct sk_buff *skb); 1025 void kfree_skb(struct sk_buff *skb); 1026 void kfree_skb_list(struct sk_buff *segs); 1027 void skb_tx_error(struct sk_buff *skb); 1028 void consume_skb(struct sk_buff *skb); 1029 void __consume_stateless_skb(struct sk_buff *skb); 1030 void __kfree_skb(struct sk_buff *skb); 1031 extern struct kmem_cache *skbuff_head_cache; 1032 1033 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 1034 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 1035 bool *fragstolen, int *delta_truesize); 1036 1037 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 1038 int node); 1039 struct sk_buff *__build_skb(void *data, unsigned int frag_size); 1040 struct sk_buff *build_skb(void *data, unsigned int frag_size); 1041 struct sk_buff *build_skb_around(struct sk_buff *skb, 1042 void *data, unsigned int frag_size); 1043 1044 /** 1045 * alloc_skb - allocate a network buffer 1046 * @size: size to allocate 1047 * @priority: allocation mask 1048 * 1049 * This function is a convenient wrapper around __alloc_skb(). 1050 */ 1051 static inline struct sk_buff *alloc_skb(unsigned int size, 1052 gfp_t priority) 1053 { 1054 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 1055 } 1056 1057 struct sk_buff *alloc_skb_with_frags(unsigned long header_len, 1058 unsigned long data_len, 1059 int max_page_order, 1060 int *errcode, 1061 gfp_t gfp_mask); 1062 1063 /* Layout of fast clones : [skb1][skb2][fclone_ref] */ 1064 struct sk_buff_fclones { 1065 struct sk_buff skb1; 1066 1067 struct sk_buff skb2; 1068 1069 refcount_t fclone_ref; 1070 }; 1071 1072 /** 1073 * skb_fclone_busy - check if fclone is busy 1074 * @sk: socket 1075 * @skb: buffer 1076 * 1077 * Returns true if skb is a fast clone, and its clone is not freed. 1078 * Some drivers call skb_orphan() in their ndo_start_xmit(), 1079 * so we also check that this didnt happen. 1080 */ 1081 static inline bool skb_fclone_busy(const struct sock *sk, 1082 const struct sk_buff *skb) 1083 { 1084 const struct sk_buff_fclones *fclones; 1085 1086 fclones = container_of(skb, struct sk_buff_fclones, skb1); 1087 1088 return skb->fclone == SKB_FCLONE_ORIG && 1089 refcount_read(&fclones->fclone_ref) > 1 && 1090 fclones->skb2.sk == sk; 1091 } 1092 1093 /** 1094 * alloc_skb_fclone - allocate a network buffer from fclone cache 1095 * @size: size to allocate 1096 * @priority: allocation mask 1097 * 1098 * This function is a convenient wrapper around __alloc_skb(). 1099 */ 1100 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 1101 gfp_t priority) 1102 { 1103 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 1104 } 1105 1106 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 1107 void skb_headers_offset_update(struct sk_buff *skb, int off); 1108 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 1109 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 1110 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old); 1111 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 1112 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, 1113 gfp_t gfp_mask, bool fclone); 1114 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, 1115 gfp_t gfp_mask) 1116 { 1117 return __pskb_copy_fclone(skb, headroom, gfp_mask, false); 1118 } 1119 1120 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 1121 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 1122 unsigned int headroom); 1123 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 1124 int newtailroom, gfp_t priority); 1125 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, 1126 int offset, int len); 1127 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, 1128 int offset, int len); 1129 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 1130 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error); 1131 1132 /** 1133 * skb_pad - zero pad the tail of an skb 1134 * @skb: buffer to pad 1135 * @pad: space to pad 1136 * 1137 * Ensure that a buffer is followed by a padding area that is zero 1138 * filled. Used by network drivers which may DMA or transfer data 1139 * beyond the buffer end onto the wire. 1140 * 1141 * May return error in out of memory cases. The skb is freed on error. 1142 */ 1143 static inline int skb_pad(struct sk_buff *skb, int pad) 1144 { 1145 return __skb_pad(skb, pad, true); 1146 } 1147 #define dev_kfree_skb(a) consume_skb(a) 1148 1149 int skb_append_pagefrags(struct sk_buff *skb, struct page *page, 1150 int offset, size_t size); 1151 1152 struct skb_seq_state { 1153 __u32 lower_offset; 1154 __u32 upper_offset; 1155 __u32 frag_idx; 1156 __u32 stepped_offset; 1157 struct sk_buff *root_skb; 1158 struct sk_buff *cur_skb; 1159 __u8 *frag_data; 1160 }; 1161 1162 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 1163 unsigned int to, struct skb_seq_state *st); 1164 unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 1165 struct skb_seq_state *st); 1166 void skb_abort_seq_read(struct skb_seq_state *st); 1167 1168 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 1169 unsigned int to, struct ts_config *config); 1170 1171 /* 1172 * Packet hash types specify the type of hash in skb_set_hash. 1173 * 1174 * Hash types refer to the protocol layer addresses which are used to 1175 * construct a packet's hash. The hashes are used to differentiate or identify 1176 * flows of the protocol layer for the hash type. Hash types are either 1177 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 1178 * 1179 * Properties of hashes: 1180 * 1181 * 1) Two packets in different flows have different hash values 1182 * 2) Two packets in the same flow should have the same hash value 1183 * 1184 * A hash at a higher layer is considered to be more specific. A driver should 1185 * set the most specific hash possible. 1186 * 1187 * A driver cannot indicate a more specific hash than the layer at which a hash 1188 * was computed. For instance an L3 hash cannot be set as an L4 hash. 1189 * 1190 * A driver may indicate a hash level which is less specific than the 1191 * actual layer the hash was computed on. For instance, a hash computed 1192 * at L4 may be considered an L3 hash. This should only be done if the 1193 * driver can't unambiguously determine that the HW computed the hash at 1194 * the higher layer. Note that the "should" in the second property above 1195 * permits this. 1196 */ 1197 enum pkt_hash_types { 1198 PKT_HASH_TYPE_NONE, /* Undefined type */ 1199 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 1200 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 1201 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 1202 }; 1203 1204 static inline void skb_clear_hash(struct sk_buff *skb) 1205 { 1206 skb->hash = 0; 1207 skb->sw_hash = 0; 1208 skb->l4_hash = 0; 1209 } 1210 1211 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 1212 { 1213 if (!skb->l4_hash) 1214 skb_clear_hash(skb); 1215 } 1216 1217 static inline void 1218 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4) 1219 { 1220 skb->l4_hash = is_l4; 1221 skb->sw_hash = is_sw; 1222 skb->hash = hash; 1223 } 1224 1225 static inline void 1226 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 1227 { 1228 /* Used by drivers to set hash from HW */ 1229 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4); 1230 } 1231 1232 static inline void 1233 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4) 1234 { 1235 __skb_set_hash(skb, hash, true, is_l4); 1236 } 1237 1238 void __skb_get_hash(struct sk_buff *skb); 1239 u32 __skb_get_hash_symmetric(const struct sk_buff *skb); 1240 u32 skb_get_poff(const struct sk_buff *skb); 1241 u32 __skb_get_poff(const struct sk_buff *skb, void *data, 1242 const struct flow_keys_basic *keys, int hlen); 1243 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 1244 void *data, int hlen_proto); 1245 1246 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, 1247 int thoff, u8 ip_proto) 1248 { 1249 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0); 1250 } 1251 1252 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 1253 const struct flow_dissector_key *key, 1254 unsigned int key_count); 1255 1256 #ifdef CONFIG_NET 1257 int skb_flow_dissector_prog_query(const union bpf_attr *attr, 1258 union bpf_attr __user *uattr); 1259 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, 1260 struct bpf_prog *prog); 1261 1262 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr); 1263 #else 1264 static inline int skb_flow_dissector_prog_query(const union bpf_attr *attr, 1265 union bpf_attr __user *uattr) 1266 { 1267 return -EOPNOTSUPP; 1268 } 1269 1270 static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, 1271 struct bpf_prog *prog) 1272 { 1273 return -EOPNOTSUPP; 1274 } 1275 1276 static inline int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr) 1277 { 1278 return -EOPNOTSUPP; 1279 } 1280 #endif 1281 1282 struct bpf_flow_dissector; 1283 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 1284 __be16 proto, int nhoff, int hlen); 1285 1286 bool __skb_flow_dissect(const struct net *net, 1287 const struct sk_buff *skb, 1288 struct flow_dissector *flow_dissector, 1289 void *target_container, 1290 void *data, __be16 proto, int nhoff, int hlen, 1291 unsigned int flags); 1292 1293 static inline bool skb_flow_dissect(const struct sk_buff *skb, 1294 struct flow_dissector *flow_dissector, 1295 void *target_container, unsigned int flags) 1296 { 1297 return __skb_flow_dissect(NULL, skb, flow_dissector, 1298 target_container, NULL, 0, 0, 0, flags); 1299 } 1300 1301 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb, 1302 struct flow_keys *flow, 1303 unsigned int flags) 1304 { 1305 memset(flow, 0, sizeof(*flow)); 1306 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector, 1307 flow, NULL, 0, 0, 0, flags); 1308 } 1309 1310 static inline bool 1311 skb_flow_dissect_flow_keys_basic(const struct net *net, 1312 const struct sk_buff *skb, 1313 struct flow_keys_basic *flow, void *data, 1314 __be16 proto, int nhoff, int hlen, 1315 unsigned int flags) 1316 { 1317 memset(flow, 0, sizeof(*flow)); 1318 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow, 1319 data, proto, nhoff, hlen, flags); 1320 } 1321 1322 void 1323 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 1324 struct flow_dissector *flow_dissector, 1325 void *target_container); 1326 1327 static inline __u32 skb_get_hash(struct sk_buff *skb) 1328 { 1329 if (!skb->l4_hash && !skb->sw_hash) 1330 __skb_get_hash(skb); 1331 1332 return skb->hash; 1333 } 1334 1335 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 1336 { 1337 if (!skb->l4_hash && !skb->sw_hash) { 1338 struct flow_keys keys; 1339 __u32 hash = __get_hash_from_flowi6(fl6, &keys); 1340 1341 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1342 } 1343 1344 return skb->hash; 1345 } 1346 1347 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb); 1348 1349 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 1350 { 1351 return skb->hash; 1352 } 1353 1354 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 1355 { 1356 to->hash = from->hash; 1357 to->sw_hash = from->sw_hash; 1358 to->l4_hash = from->l4_hash; 1359 }; 1360 1361 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1362 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1363 { 1364 return skb->head + skb->end; 1365 } 1366 1367 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1368 { 1369 return skb->end; 1370 } 1371 #else 1372 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1373 { 1374 return skb->end; 1375 } 1376 1377 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1378 { 1379 return skb->end - skb->head; 1380 } 1381 #endif 1382 1383 /* Internal */ 1384 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 1385 1386 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 1387 { 1388 return &skb_shinfo(skb)->hwtstamps; 1389 } 1390 1391 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb) 1392 { 1393 bool is_zcopy = skb && skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY; 1394 1395 return is_zcopy ? skb_uarg(skb) : NULL; 1396 } 1397 1398 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, 1399 bool *have_ref) 1400 { 1401 if (skb && uarg && !skb_zcopy(skb)) { 1402 if (unlikely(have_ref && *have_ref)) 1403 *have_ref = false; 1404 else 1405 sock_zerocopy_get(uarg); 1406 skb_shinfo(skb)->destructor_arg = uarg; 1407 skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG; 1408 } 1409 } 1410 1411 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val) 1412 { 1413 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL); 1414 skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG; 1415 } 1416 1417 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb) 1418 { 1419 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL; 1420 } 1421 1422 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb) 1423 { 1424 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL); 1425 } 1426 1427 /* Release a reference on a zerocopy structure */ 1428 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy) 1429 { 1430 struct ubuf_info *uarg = skb_zcopy(skb); 1431 1432 if (uarg) { 1433 if (skb_zcopy_is_nouarg(skb)) { 1434 /* no notification callback */ 1435 } else if (uarg->callback == sock_zerocopy_callback) { 1436 uarg->zerocopy = uarg->zerocopy && zerocopy; 1437 sock_zerocopy_put(uarg); 1438 } else { 1439 uarg->callback(uarg, zerocopy); 1440 } 1441 1442 skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG; 1443 } 1444 } 1445 1446 /* Abort a zerocopy operation and revert zckey on error in send syscall */ 1447 static inline void skb_zcopy_abort(struct sk_buff *skb) 1448 { 1449 struct ubuf_info *uarg = skb_zcopy(skb); 1450 1451 if (uarg) { 1452 sock_zerocopy_put_abort(uarg, false); 1453 skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG; 1454 } 1455 } 1456 1457 static inline void skb_mark_not_on_list(struct sk_buff *skb) 1458 { 1459 skb->next = NULL; 1460 } 1461 1462 static inline void skb_list_del_init(struct sk_buff *skb) 1463 { 1464 __list_del_entry(&skb->list); 1465 skb_mark_not_on_list(skb); 1466 } 1467 1468 /** 1469 * skb_queue_empty - check if a queue is empty 1470 * @list: queue head 1471 * 1472 * Returns true if the queue is empty, false otherwise. 1473 */ 1474 static inline int skb_queue_empty(const struct sk_buff_head *list) 1475 { 1476 return list->next == (const struct sk_buff *) list; 1477 } 1478 1479 /** 1480 * skb_queue_is_last - check if skb is the last entry in the queue 1481 * @list: queue head 1482 * @skb: buffer 1483 * 1484 * Returns true if @skb is the last buffer on the list. 1485 */ 1486 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 1487 const struct sk_buff *skb) 1488 { 1489 return skb->next == (const struct sk_buff *) list; 1490 } 1491 1492 /** 1493 * skb_queue_is_first - check if skb is the first entry in the queue 1494 * @list: queue head 1495 * @skb: buffer 1496 * 1497 * Returns true if @skb is the first buffer on the list. 1498 */ 1499 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 1500 const struct sk_buff *skb) 1501 { 1502 return skb->prev == (const struct sk_buff *) list; 1503 } 1504 1505 /** 1506 * skb_queue_next - return the next packet in the queue 1507 * @list: queue head 1508 * @skb: current buffer 1509 * 1510 * Return the next packet in @list after @skb. It is only valid to 1511 * call this if skb_queue_is_last() evaluates to false. 1512 */ 1513 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 1514 const struct sk_buff *skb) 1515 { 1516 /* This BUG_ON may seem severe, but if we just return then we 1517 * are going to dereference garbage. 1518 */ 1519 BUG_ON(skb_queue_is_last(list, skb)); 1520 return skb->next; 1521 } 1522 1523 /** 1524 * skb_queue_prev - return the prev packet in the queue 1525 * @list: queue head 1526 * @skb: current buffer 1527 * 1528 * Return the prev packet in @list before @skb. It is only valid to 1529 * call this if skb_queue_is_first() evaluates to false. 1530 */ 1531 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 1532 const struct sk_buff *skb) 1533 { 1534 /* This BUG_ON may seem severe, but if we just return then we 1535 * are going to dereference garbage. 1536 */ 1537 BUG_ON(skb_queue_is_first(list, skb)); 1538 return skb->prev; 1539 } 1540 1541 /** 1542 * skb_get - reference buffer 1543 * @skb: buffer to reference 1544 * 1545 * Makes another reference to a socket buffer and returns a pointer 1546 * to the buffer. 1547 */ 1548 static inline struct sk_buff *skb_get(struct sk_buff *skb) 1549 { 1550 refcount_inc(&skb->users); 1551 return skb; 1552 } 1553 1554 /* 1555 * If users == 1, we are the only owner and can avoid redundant atomic changes. 1556 */ 1557 1558 /** 1559 * skb_cloned - is the buffer a clone 1560 * @skb: buffer to check 1561 * 1562 * Returns true if the buffer was generated with skb_clone() and is 1563 * one of multiple shared copies of the buffer. Cloned buffers are 1564 * shared data so must not be written to under normal circumstances. 1565 */ 1566 static inline int skb_cloned(const struct sk_buff *skb) 1567 { 1568 return skb->cloned && 1569 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 1570 } 1571 1572 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 1573 { 1574 might_sleep_if(gfpflags_allow_blocking(pri)); 1575 1576 if (skb_cloned(skb)) 1577 return pskb_expand_head(skb, 0, 0, pri); 1578 1579 return 0; 1580 } 1581 1582 /** 1583 * skb_header_cloned - is the header a clone 1584 * @skb: buffer to check 1585 * 1586 * Returns true if modifying the header part of the buffer requires 1587 * the data to be copied. 1588 */ 1589 static inline int skb_header_cloned(const struct sk_buff *skb) 1590 { 1591 int dataref; 1592 1593 if (!skb->cloned) 1594 return 0; 1595 1596 dataref = atomic_read(&skb_shinfo(skb)->dataref); 1597 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 1598 return dataref != 1; 1599 } 1600 1601 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri) 1602 { 1603 might_sleep_if(gfpflags_allow_blocking(pri)); 1604 1605 if (skb_header_cloned(skb)) 1606 return pskb_expand_head(skb, 0, 0, pri); 1607 1608 return 0; 1609 } 1610 1611 /** 1612 * __skb_header_release - release reference to header 1613 * @skb: buffer to operate on 1614 */ 1615 static inline void __skb_header_release(struct sk_buff *skb) 1616 { 1617 skb->nohdr = 1; 1618 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT)); 1619 } 1620 1621 1622 /** 1623 * skb_shared - is the buffer shared 1624 * @skb: buffer to check 1625 * 1626 * Returns true if more than one person has a reference to this 1627 * buffer. 1628 */ 1629 static inline int skb_shared(const struct sk_buff *skb) 1630 { 1631 return refcount_read(&skb->users) != 1; 1632 } 1633 1634 /** 1635 * skb_share_check - check if buffer is shared and if so clone it 1636 * @skb: buffer to check 1637 * @pri: priority for memory allocation 1638 * 1639 * If the buffer is shared the buffer is cloned and the old copy 1640 * drops a reference. A new clone with a single reference is returned. 1641 * If the buffer is not shared the original buffer is returned. When 1642 * being called from interrupt status or with spinlocks held pri must 1643 * be GFP_ATOMIC. 1644 * 1645 * NULL is returned on a memory allocation failure. 1646 */ 1647 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 1648 { 1649 might_sleep_if(gfpflags_allow_blocking(pri)); 1650 if (skb_shared(skb)) { 1651 struct sk_buff *nskb = skb_clone(skb, pri); 1652 1653 if (likely(nskb)) 1654 consume_skb(skb); 1655 else 1656 kfree_skb(skb); 1657 skb = nskb; 1658 } 1659 return skb; 1660 } 1661 1662 /* 1663 * Copy shared buffers into a new sk_buff. We effectively do COW on 1664 * packets to handle cases where we have a local reader and forward 1665 * and a couple of other messy ones. The normal one is tcpdumping 1666 * a packet thats being forwarded. 1667 */ 1668 1669 /** 1670 * skb_unshare - make a copy of a shared buffer 1671 * @skb: buffer to check 1672 * @pri: priority for memory allocation 1673 * 1674 * If the socket buffer is a clone then this function creates a new 1675 * copy of the data, drops a reference count on the old copy and returns 1676 * the new copy with the reference count at 1. If the buffer is not a clone 1677 * the original buffer is returned. When called with a spinlock held or 1678 * from interrupt state @pri must be %GFP_ATOMIC 1679 * 1680 * %NULL is returned on a memory allocation failure. 1681 */ 1682 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 1683 gfp_t pri) 1684 { 1685 might_sleep_if(gfpflags_allow_blocking(pri)); 1686 if (skb_cloned(skb)) { 1687 struct sk_buff *nskb = skb_copy(skb, pri); 1688 1689 /* Free our shared copy */ 1690 if (likely(nskb)) 1691 consume_skb(skb); 1692 else 1693 kfree_skb(skb); 1694 skb = nskb; 1695 } 1696 return skb; 1697 } 1698 1699 /** 1700 * skb_peek - peek at the head of an &sk_buff_head 1701 * @list_: list to peek at 1702 * 1703 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1704 * be careful with this one. A peek leaves the buffer on the 1705 * list and someone else may run off with it. You must hold 1706 * the appropriate locks or have a private queue to do this. 1707 * 1708 * Returns %NULL for an empty list or a pointer to the head element. 1709 * The reference count is not incremented and the reference is therefore 1710 * volatile. Use with caution. 1711 */ 1712 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 1713 { 1714 struct sk_buff *skb = list_->next; 1715 1716 if (skb == (struct sk_buff *)list_) 1717 skb = NULL; 1718 return skb; 1719 } 1720 1721 /** 1722 * __skb_peek - peek at the head of a non-empty &sk_buff_head 1723 * @list_: list to peek at 1724 * 1725 * Like skb_peek(), but the caller knows that the list is not empty. 1726 */ 1727 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_) 1728 { 1729 return list_->next; 1730 } 1731 1732 /** 1733 * skb_peek_next - peek skb following the given one from a queue 1734 * @skb: skb to start from 1735 * @list_: list to peek at 1736 * 1737 * Returns %NULL when the end of the list is met or a pointer to the 1738 * next element. The reference count is not incremented and the 1739 * reference is therefore volatile. Use with caution. 1740 */ 1741 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 1742 const struct sk_buff_head *list_) 1743 { 1744 struct sk_buff *next = skb->next; 1745 1746 if (next == (struct sk_buff *)list_) 1747 next = NULL; 1748 return next; 1749 } 1750 1751 /** 1752 * skb_peek_tail - peek at the tail of an &sk_buff_head 1753 * @list_: list to peek at 1754 * 1755 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1756 * be careful with this one. A peek leaves the buffer on the 1757 * list and someone else may run off with it. You must hold 1758 * the appropriate locks or have a private queue to do this. 1759 * 1760 * Returns %NULL for an empty list or a pointer to the tail element. 1761 * The reference count is not incremented and the reference is therefore 1762 * volatile. Use with caution. 1763 */ 1764 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 1765 { 1766 struct sk_buff *skb = list_->prev; 1767 1768 if (skb == (struct sk_buff *)list_) 1769 skb = NULL; 1770 return skb; 1771 1772 } 1773 1774 /** 1775 * skb_queue_len - get queue length 1776 * @list_: list to measure 1777 * 1778 * Return the length of an &sk_buff queue. 1779 */ 1780 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 1781 { 1782 return list_->qlen; 1783 } 1784 1785 /** 1786 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 1787 * @list: queue to initialize 1788 * 1789 * This initializes only the list and queue length aspects of 1790 * an sk_buff_head object. This allows to initialize the list 1791 * aspects of an sk_buff_head without reinitializing things like 1792 * the spinlock. It can also be used for on-stack sk_buff_head 1793 * objects where the spinlock is known to not be used. 1794 */ 1795 static inline void __skb_queue_head_init(struct sk_buff_head *list) 1796 { 1797 list->prev = list->next = (struct sk_buff *)list; 1798 list->qlen = 0; 1799 } 1800 1801 /* 1802 * This function creates a split out lock class for each invocation; 1803 * this is needed for now since a whole lot of users of the skb-queue 1804 * infrastructure in drivers have different locking usage (in hardirq) 1805 * than the networking core (in softirq only). In the long run either the 1806 * network layer or drivers should need annotation to consolidate the 1807 * main types of usage into 3 classes. 1808 */ 1809 static inline void skb_queue_head_init(struct sk_buff_head *list) 1810 { 1811 spin_lock_init(&list->lock); 1812 __skb_queue_head_init(list); 1813 } 1814 1815 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 1816 struct lock_class_key *class) 1817 { 1818 skb_queue_head_init(list); 1819 lockdep_set_class(&list->lock, class); 1820 } 1821 1822 /* 1823 * Insert an sk_buff on a list. 1824 * 1825 * The "__skb_xxxx()" functions are the non-atomic ones that 1826 * can only be called with interrupts disabled. 1827 */ 1828 static inline void __skb_insert(struct sk_buff *newsk, 1829 struct sk_buff *prev, struct sk_buff *next, 1830 struct sk_buff_head *list) 1831 { 1832 newsk->next = next; 1833 newsk->prev = prev; 1834 next->prev = prev->next = newsk; 1835 list->qlen++; 1836 } 1837 1838 static inline void __skb_queue_splice(const struct sk_buff_head *list, 1839 struct sk_buff *prev, 1840 struct sk_buff *next) 1841 { 1842 struct sk_buff *first = list->next; 1843 struct sk_buff *last = list->prev; 1844 1845 first->prev = prev; 1846 prev->next = first; 1847 1848 last->next = next; 1849 next->prev = last; 1850 } 1851 1852 /** 1853 * skb_queue_splice - join two skb lists, this is designed for stacks 1854 * @list: the new list to add 1855 * @head: the place to add it in the first list 1856 */ 1857 static inline void skb_queue_splice(const struct sk_buff_head *list, 1858 struct sk_buff_head *head) 1859 { 1860 if (!skb_queue_empty(list)) { 1861 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1862 head->qlen += list->qlen; 1863 } 1864 } 1865 1866 /** 1867 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 1868 * @list: the new list to add 1869 * @head: the place to add it in the first list 1870 * 1871 * The list at @list is reinitialised 1872 */ 1873 static inline void skb_queue_splice_init(struct sk_buff_head *list, 1874 struct sk_buff_head *head) 1875 { 1876 if (!skb_queue_empty(list)) { 1877 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1878 head->qlen += list->qlen; 1879 __skb_queue_head_init(list); 1880 } 1881 } 1882 1883 /** 1884 * skb_queue_splice_tail - join two skb lists, each list being a queue 1885 * @list: the new list to add 1886 * @head: the place to add it in the first list 1887 */ 1888 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 1889 struct sk_buff_head *head) 1890 { 1891 if (!skb_queue_empty(list)) { 1892 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1893 head->qlen += list->qlen; 1894 } 1895 } 1896 1897 /** 1898 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 1899 * @list: the new list to add 1900 * @head: the place to add it in the first list 1901 * 1902 * Each of the lists is a queue. 1903 * The list at @list is reinitialised 1904 */ 1905 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 1906 struct sk_buff_head *head) 1907 { 1908 if (!skb_queue_empty(list)) { 1909 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1910 head->qlen += list->qlen; 1911 __skb_queue_head_init(list); 1912 } 1913 } 1914 1915 /** 1916 * __skb_queue_after - queue a buffer at the list head 1917 * @list: list to use 1918 * @prev: place after this buffer 1919 * @newsk: buffer to queue 1920 * 1921 * Queue a buffer int the middle of a list. This function takes no locks 1922 * and you must therefore hold required locks before calling it. 1923 * 1924 * A buffer cannot be placed on two lists at the same time. 1925 */ 1926 static inline void __skb_queue_after(struct sk_buff_head *list, 1927 struct sk_buff *prev, 1928 struct sk_buff *newsk) 1929 { 1930 __skb_insert(newsk, prev, prev->next, list); 1931 } 1932 1933 void skb_append(struct sk_buff *old, struct sk_buff *newsk, 1934 struct sk_buff_head *list); 1935 1936 static inline void __skb_queue_before(struct sk_buff_head *list, 1937 struct sk_buff *next, 1938 struct sk_buff *newsk) 1939 { 1940 __skb_insert(newsk, next->prev, next, list); 1941 } 1942 1943 /** 1944 * __skb_queue_head - queue a buffer at the list head 1945 * @list: list to use 1946 * @newsk: buffer to queue 1947 * 1948 * Queue a buffer at the start of a list. This function takes no locks 1949 * and you must therefore hold required locks before calling it. 1950 * 1951 * A buffer cannot be placed on two lists at the same time. 1952 */ 1953 static inline void __skb_queue_head(struct sk_buff_head *list, 1954 struct sk_buff *newsk) 1955 { 1956 __skb_queue_after(list, (struct sk_buff *)list, newsk); 1957 } 1958 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 1959 1960 /** 1961 * __skb_queue_tail - queue a buffer at the list tail 1962 * @list: list to use 1963 * @newsk: buffer to queue 1964 * 1965 * Queue a buffer at the end of a list. This function takes no locks 1966 * and you must therefore hold required locks before calling it. 1967 * 1968 * A buffer cannot be placed on two lists at the same time. 1969 */ 1970 static inline void __skb_queue_tail(struct sk_buff_head *list, 1971 struct sk_buff *newsk) 1972 { 1973 __skb_queue_before(list, (struct sk_buff *)list, newsk); 1974 } 1975 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 1976 1977 /* 1978 * remove sk_buff from list. _Must_ be called atomically, and with 1979 * the list known.. 1980 */ 1981 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 1982 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 1983 { 1984 struct sk_buff *next, *prev; 1985 1986 list->qlen--; 1987 next = skb->next; 1988 prev = skb->prev; 1989 skb->next = skb->prev = NULL; 1990 next->prev = prev; 1991 prev->next = next; 1992 } 1993 1994 /** 1995 * __skb_dequeue - remove from the head of the queue 1996 * @list: list to dequeue from 1997 * 1998 * Remove the head of the list. This function does not take any locks 1999 * so must be used with appropriate locks held only. The head item is 2000 * returned or %NULL if the list is empty. 2001 */ 2002 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 2003 { 2004 struct sk_buff *skb = skb_peek(list); 2005 if (skb) 2006 __skb_unlink(skb, list); 2007 return skb; 2008 } 2009 struct sk_buff *skb_dequeue(struct sk_buff_head *list); 2010 2011 /** 2012 * __skb_dequeue_tail - remove from the tail of the queue 2013 * @list: list to dequeue from 2014 * 2015 * Remove the tail of the list. This function does not take any locks 2016 * so must be used with appropriate locks held only. The tail item is 2017 * returned or %NULL if the list is empty. 2018 */ 2019 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 2020 { 2021 struct sk_buff *skb = skb_peek_tail(list); 2022 if (skb) 2023 __skb_unlink(skb, list); 2024 return skb; 2025 } 2026 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 2027 2028 2029 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 2030 { 2031 return skb->data_len; 2032 } 2033 2034 static inline unsigned int skb_headlen(const struct sk_buff *skb) 2035 { 2036 return skb->len - skb->data_len; 2037 } 2038 2039 static inline unsigned int __skb_pagelen(const struct sk_buff *skb) 2040 { 2041 unsigned int i, len = 0; 2042 2043 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--) 2044 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 2045 return len; 2046 } 2047 2048 static inline unsigned int skb_pagelen(const struct sk_buff *skb) 2049 { 2050 return skb_headlen(skb) + __skb_pagelen(skb); 2051 } 2052 2053 /** 2054 * __skb_fill_page_desc - initialise a paged fragment in an skb 2055 * @skb: buffer containing fragment to be initialised 2056 * @i: paged fragment index to initialise 2057 * @page: the page to use for this fragment 2058 * @off: the offset to the data with @page 2059 * @size: the length of the data 2060 * 2061 * Initialises the @i'th fragment of @skb to point to &size bytes at 2062 * offset @off within @page. 2063 * 2064 * Does not take any additional reference on the fragment. 2065 */ 2066 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 2067 struct page *page, int off, int size) 2068 { 2069 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 2070 2071 /* 2072 * Propagate page pfmemalloc to the skb if we can. The problem is 2073 * that not all callers have unique ownership of the page but rely 2074 * on page_is_pfmemalloc doing the right thing(tm). 2075 */ 2076 frag->page.p = page; 2077 frag->page_offset = off; 2078 skb_frag_size_set(frag, size); 2079 2080 page = compound_head(page); 2081 if (page_is_pfmemalloc(page)) 2082 skb->pfmemalloc = true; 2083 } 2084 2085 /** 2086 * skb_fill_page_desc - initialise a paged fragment in an skb 2087 * @skb: buffer containing fragment to be initialised 2088 * @i: paged fragment index to initialise 2089 * @page: the page to use for this fragment 2090 * @off: the offset to the data with @page 2091 * @size: the length of the data 2092 * 2093 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 2094 * @skb to point to @size bytes at offset @off within @page. In 2095 * addition updates @skb such that @i is the last fragment. 2096 * 2097 * Does not take any additional reference on the fragment. 2098 */ 2099 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 2100 struct page *page, int off, int size) 2101 { 2102 __skb_fill_page_desc(skb, i, page, off, size); 2103 skb_shinfo(skb)->nr_frags = i + 1; 2104 } 2105 2106 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, 2107 int size, unsigned int truesize); 2108 2109 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 2110 unsigned int truesize); 2111 2112 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 2113 2114 #ifdef NET_SKBUFF_DATA_USES_OFFSET 2115 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2116 { 2117 return skb->head + skb->tail; 2118 } 2119 2120 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2121 { 2122 skb->tail = skb->data - skb->head; 2123 } 2124 2125 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2126 { 2127 skb_reset_tail_pointer(skb); 2128 skb->tail += offset; 2129 } 2130 2131 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 2132 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2133 { 2134 return skb->tail; 2135 } 2136 2137 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2138 { 2139 skb->tail = skb->data; 2140 } 2141 2142 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2143 { 2144 skb->tail = skb->data + offset; 2145 } 2146 2147 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 2148 2149 /* 2150 * Add data to an sk_buff 2151 */ 2152 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 2153 void *skb_put(struct sk_buff *skb, unsigned int len); 2154 static inline void *__skb_put(struct sk_buff *skb, unsigned int len) 2155 { 2156 void *tmp = skb_tail_pointer(skb); 2157 SKB_LINEAR_ASSERT(skb); 2158 skb->tail += len; 2159 skb->len += len; 2160 return tmp; 2161 } 2162 2163 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len) 2164 { 2165 void *tmp = __skb_put(skb, len); 2166 2167 memset(tmp, 0, len); 2168 return tmp; 2169 } 2170 2171 static inline void *__skb_put_data(struct sk_buff *skb, const void *data, 2172 unsigned int len) 2173 { 2174 void *tmp = __skb_put(skb, len); 2175 2176 memcpy(tmp, data, len); 2177 return tmp; 2178 } 2179 2180 static inline void __skb_put_u8(struct sk_buff *skb, u8 val) 2181 { 2182 *(u8 *)__skb_put(skb, 1) = val; 2183 } 2184 2185 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len) 2186 { 2187 void *tmp = skb_put(skb, len); 2188 2189 memset(tmp, 0, len); 2190 2191 return tmp; 2192 } 2193 2194 static inline void *skb_put_data(struct sk_buff *skb, const void *data, 2195 unsigned int len) 2196 { 2197 void *tmp = skb_put(skb, len); 2198 2199 memcpy(tmp, data, len); 2200 2201 return tmp; 2202 } 2203 2204 static inline void skb_put_u8(struct sk_buff *skb, u8 val) 2205 { 2206 *(u8 *)skb_put(skb, 1) = val; 2207 } 2208 2209 void *skb_push(struct sk_buff *skb, unsigned int len); 2210 static inline void *__skb_push(struct sk_buff *skb, unsigned int len) 2211 { 2212 skb->data -= len; 2213 skb->len += len; 2214 return skb->data; 2215 } 2216 2217 void *skb_pull(struct sk_buff *skb, unsigned int len); 2218 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) 2219 { 2220 skb->len -= len; 2221 BUG_ON(skb->len < skb->data_len); 2222 return skb->data += len; 2223 } 2224 2225 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len) 2226 { 2227 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 2228 } 2229 2230 void *__pskb_pull_tail(struct sk_buff *skb, int delta); 2231 2232 static inline void *__pskb_pull(struct sk_buff *skb, unsigned int len) 2233 { 2234 if (len > skb_headlen(skb) && 2235 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 2236 return NULL; 2237 skb->len -= len; 2238 return skb->data += len; 2239 } 2240 2241 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len) 2242 { 2243 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 2244 } 2245 2246 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) 2247 { 2248 if (likely(len <= skb_headlen(skb))) 2249 return 1; 2250 if (unlikely(len > skb->len)) 2251 return 0; 2252 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 2253 } 2254 2255 void skb_condense(struct sk_buff *skb); 2256 2257 /** 2258 * skb_headroom - bytes at buffer head 2259 * @skb: buffer to check 2260 * 2261 * Return the number of bytes of free space at the head of an &sk_buff. 2262 */ 2263 static inline unsigned int skb_headroom(const struct sk_buff *skb) 2264 { 2265 return skb->data - skb->head; 2266 } 2267 2268 /** 2269 * skb_tailroom - bytes at buffer end 2270 * @skb: buffer to check 2271 * 2272 * Return the number of bytes of free space at the tail of an sk_buff 2273 */ 2274 static inline int skb_tailroom(const struct sk_buff *skb) 2275 { 2276 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 2277 } 2278 2279 /** 2280 * skb_availroom - bytes at buffer end 2281 * @skb: buffer to check 2282 * 2283 * Return the number of bytes of free space at the tail of an sk_buff 2284 * allocated by sk_stream_alloc() 2285 */ 2286 static inline int skb_availroom(const struct sk_buff *skb) 2287 { 2288 if (skb_is_nonlinear(skb)) 2289 return 0; 2290 2291 return skb->end - skb->tail - skb->reserved_tailroom; 2292 } 2293 2294 /** 2295 * skb_reserve - adjust headroom 2296 * @skb: buffer to alter 2297 * @len: bytes to move 2298 * 2299 * Increase the headroom of an empty &sk_buff by reducing the tail 2300 * room. This is only allowed for an empty buffer. 2301 */ 2302 static inline void skb_reserve(struct sk_buff *skb, int len) 2303 { 2304 skb->data += len; 2305 skb->tail += len; 2306 } 2307 2308 /** 2309 * skb_tailroom_reserve - adjust reserved_tailroom 2310 * @skb: buffer to alter 2311 * @mtu: maximum amount of headlen permitted 2312 * @needed_tailroom: minimum amount of reserved_tailroom 2313 * 2314 * Set reserved_tailroom so that headlen can be as large as possible but 2315 * not larger than mtu and tailroom cannot be smaller than 2316 * needed_tailroom. 2317 * The required headroom should already have been reserved before using 2318 * this function. 2319 */ 2320 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu, 2321 unsigned int needed_tailroom) 2322 { 2323 SKB_LINEAR_ASSERT(skb); 2324 if (mtu < skb_tailroom(skb) - needed_tailroom) 2325 /* use at most mtu */ 2326 skb->reserved_tailroom = skb_tailroom(skb) - mtu; 2327 else 2328 /* use up to all available space */ 2329 skb->reserved_tailroom = needed_tailroom; 2330 } 2331 2332 #define ENCAP_TYPE_ETHER 0 2333 #define ENCAP_TYPE_IPPROTO 1 2334 2335 static inline void skb_set_inner_protocol(struct sk_buff *skb, 2336 __be16 protocol) 2337 { 2338 skb->inner_protocol = protocol; 2339 skb->inner_protocol_type = ENCAP_TYPE_ETHER; 2340 } 2341 2342 static inline void skb_set_inner_ipproto(struct sk_buff *skb, 2343 __u8 ipproto) 2344 { 2345 skb->inner_ipproto = ipproto; 2346 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; 2347 } 2348 2349 static inline void skb_reset_inner_headers(struct sk_buff *skb) 2350 { 2351 skb->inner_mac_header = skb->mac_header; 2352 skb->inner_network_header = skb->network_header; 2353 skb->inner_transport_header = skb->transport_header; 2354 } 2355 2356 static inline void skb_reset_mac_len(struct sk_buff *skb) 2357 { 2358 skb->mac_len = skb->network_header - skb->mac_header; 2359 } 2360 2361 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 2362 *skb) 2363 { 2364 return skb->head + skb->inner_transport_header; 2365 } 2366 2367 static inline int skb_inner_transport_offset(const struct sk_buff *skb) 2368 { 2369 return skb_inner_transport_header(skb) - skb->data; 2370 } 2371 2372 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 2373 { 2374 skb->inner_transport_header = skb->data - skb->head; 2375 } 2376 2377 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 2378 const int offset) 2379 { 2380 skb_reset_inner_transport_header(skb); 2381 skb->inner_transport_header += offset; 2382 } 2383 2384 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 2385 { 2386 return skb->head + skb->inner_network_header; 2387 } 2388 2389 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 2390 { 2391 skb->inner_network_header = skb->data - skb->head; 2392 } 2393 2394 static inline void skb_set_inner_network_header(struct sk_buff *skb, 2395 const int offset) 2396 { 2397 skb_reset_inner_network_header(skb); 2398 skb->inner_network_header += offset; 2399 } 2400 2401 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 2402 { 2403 return skb->head + skb->inner_mac_header; 2404 } 2405 2406 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 2407 { 2408 skb->inner_mac_header = skb->data - skb->head; 2409 } 2410 2411 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 2412 const int offset) 2413 { 2414 skb_reset_inner_mac_header(skb); 2415 skb->inner_mac_header += offset; 2416 } 2417 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 2418 { 2419 return skb->transport_header != (typeof(skb->transport_header))~0U; 2420 } 2421 2422 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 2423 { 2424 return skb->head + skb->transport_header; 2425 } 2426 2427 static inline void skb_reset_transport_header(struct sk_buff *skb) 2428 { 2429 skb->transport_header = skb->data - skb->head; 2430 } 2431 2432 static inline void skb_set_transport_header(struct sk_buff *skb, 2433 const int offset) 2434 { 2435 skb_reset_transport_header(skb); 2436 skb->transport_header += offset; 2437 } 2438 2439 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 2440 { 2441 return skb->head + skb->network_header; 2442 } 2443 2444 static inline void skb_reset_network_header(struct sk_buff *skb) 2445 { 2446 skb->network_header = skb->data - skb->head; 2447 } 2448 2449 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 2450 { 2451 skb_reset_network_header(skb); 2452 skb->network_header += offset; 2453 } 2454 2455 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 2456 { 2457 return skb->head + skb->mac_header; 2458 } 2459 2460 static inline int skb_mac_offset(const struct sk_buff *skb) 2461 { 2462 return skb_mac_header(skb) - skb->data; 2463 } 2464 2465 static inline u32 skb_mac_header_len(const struct sk_buff *skb) 2466 { 2467 return skb->network_header - skb->mac_header; 2468 } 2469 2470 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 2471 { 2472 return skb->mac_header != (typeof(skb->mac_header))~0U; 2473 } 2474 2475 static inline void skb_reset_mac_header(struct sk_buff *skb) 2476 { 2477 skb->mac_header = skb->data - skb->head; 2478 } 2479 2480 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 2481 { 2482 skb_reset_mac_header(skb); 2483 skb->mac_header += offset; 2484 } 2485 2486 static inline void skb_pop_mac_header(struct sk_buff *skb) 2487 { 2488 skb->mac_header = skb->network_header; 2489 } 2490 2491 static inline void skb_probe_transport_header(struct sk_buff *skb) 2492 { 2493 struct flow_keys_basic keys; 2494 2495 if (skb_transport_header_was_set(skb)) 2496 return; 2497 2498 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 2499 NULL, 0, 0, 0, 0)) 2500 skb_set_transport_header(skb, keys.control.thoff); 2501 } 2502 2503 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 2504 { 2505 if (skb_mac_header_was_set(skb)) { 2506 const unsigned char *old_mac = skb_mac_header(skb); 2507 2508 skb_set_mac_header(skb, -skb->mac_len); 2509 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 2510 } 2511 } 2512 2513 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 2514 { 2515 return skb->csum_start - skb_headroom(skb); 2516 } 2517 2518 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb) 2519 { 2520 return skb->head + skb->csum_start; 2521 } 2522 2523 static inline int skb_transport_offset(const struct sk_buff *skb) 2524 { 2525 return skb_transport_header(skb) - skb->data; 2526 } 2527 2528 static inline u32 skb_network_header_len(const struct sk_buff *skb) 2529 { 2530 return skb->transport_header - skb->network_header; 2531 } 2532 2533 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 2534 { 2535 return skb->inner_transport_header - skb->inner_network_header; 2536 } 2537 2538 static inline int skb_network_offset(const struct sk_buff *skb) 2539 { 2540 return skb_network_header(skb) - skb->data; 2541 } 2542 2543 static inline int skb_inner_network_offset(const struct sk_buff *skb) 2544 { 2545 return skb_inner_network_header(skb) - skb->data; 2546 } 2547 2548 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 2549 { 2550 return pskb_may_pull(skb, skb_network_offset(skb) + len); 2551 } 2552 2553 /* 2554 * CPUs often take a performance hit when accessing unaligned memory 2555 * locations. The actual performance hit varies, it can be small if the 2556 * hardware handles it or large if we have to take an exception and fix it 2557 * in software. 2558 * 2559 * Since an ethernet header is 14 bytes network drivers often end up with 2560 * the IP header at an unaligned offset. The IP header can be aligned by 2561 * shifting the start of the packet by 2 bytes. Drivers should do this 2562 * with: 2563 * 2564 * skb_reserve(skb, NET_IP_ALIGN); 2565 * 2566 * The downside to this alignment of the IP header is that the DMA is now 2567 * unaligned. On some architectures the cost of an unaligned DMA is high 2568 * and this cost outweighs the gains made by aligning the IP header. 2569 * 2570 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 2571 * to be overridden. 2572 */ 2573 #ifndef NET_IP_ALIGN 2574 #define NET_IP_ALIGN 2 2575 #endif 2576 2577 /* 2578 * The networking layer reserves some headroom in skb data (via 2579 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 2580 * the header has to grow. In the default case, if the header has to grow 2581 * 32 bytes or less we avoid the reallocation. 2582 * 2583 * Unfortunately this headroom changes the DMA alignment of the resulting 2584 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 2585 * on some architectures. An architecture can override this value, 2586 * perhaps setting it to a cacheline in size (since that will maintain 2587 * cacheline alignment of the DMA). It must be a power of 2. 2588 * 2589 * Various parts of the networking layer expect at least 32 bytes of 2590 * headroom, you should not reduce this. 2591 * 2592 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 2593 * to reduce average number of cache lines per packet. 2594 * get_rps_cpus() for example only access one 64 bytes aligned block : 2595 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 2596 */ 2597 #ifndef NET_SKB_PAD 2598 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 2599 #endif 2600 2601 int ___pskb_trim(struct sk_buff *skb, unsigned int len); 2602 2603 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len) 2604 { 2605 if (WARN_ON(skb_is_nonlinear(skb))) 2606 return; 2607 skb->len = len; 2608 skb_set_tail_pointer(skb, len); 2609 } 2610 2611 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 2612 { 2613 __skb_set_length(skb, len); 2614 } 2615 2616 void skb_trim(struct sk_buff *skb, unsigned int len); 2617 2618 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 2619 { 2620 if (skb->data_len) 2621 return ___pskb_trim(skb, len); 2622 __skb_trim(skb, len); 2623 return 0; 2624 } 2625 2626 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 2627 { 2628 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 2629 } 2630 2631 /** 2632 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 2633 * @skb: buffer to alter 2634 * @len: new length 2635 * 2636 * This is identical to pskb_trim except that the caller knows that 2637 * the skb is not cloned so we should never get an error due to out- 2638 * of-memory. 2639 */ 2640 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 2641 { 2642 int err = pskb_trim(skb, len); 2643 BUG_ON(err); 2644 } 2645 2646 static inline int __skb_grow(struct sk_buff *skb, unsigned int len) 2647 { 2648 unsigned int diff = len - skb->len; 2649 2650 if (skb_tailroom(skb) < diff) { 2651 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb), 2652 GFP_ATOMIC); 2653 if (ret) 2654 return ret; 2655 } 2656 __skb_set_length(skb, len); 2657 return 0; 2658 } 2659 2660 /** 2661 * skb_orphan - orphan a buffer 2662 * @skb: buffer to orphan 2663 * 2664 * If a buffer currently has an owner then we call the owner's 2665 * destructor function and make the @skb unowned. The buffer continues 2666 * to exist but is no longer charged to its former owner. 2667 */ 2668 static inline void skb_orphan(struct sk_buff *skb) 2669 { 2670 if (skb->destructor) { 2671 skb->destructor(skb); 2672 skb->destructor = NULL; 2673 skb->sk = NULL; 2674 } else { 2675 BUG_ON(skb->sk); 2676 } 2677 } 2678 2679 /** 2680 * skb_orphan_frags - orphan the frags contained in a buffer 2681 * @skb: buffer to orphan frags from 2682 * @gfp_mask: allocation mask for replacement pages 2683 * 2684 * For each frag in the SKB which needs a destructor (i.e. has an 2685 * owner) create a copy of that frag and release the original 2686 * page by calling the destructor. 2687 */ 2688 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 2689 { 2690 if (likely(!skb_zcopy(skb))) 2691 return 0; 2692 if (!skb_zcopy_is_nouarg(skb) && 2693 skb_uarg(skb)->callback == sock_zerocopy_callback) 2694 return 0; 2695 return skb_copy_ubufs(skb, gfp_mask); 2696 } 2697 2698 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */ 2699 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask) 2700 { 2701 if (likely(!skb_zcopy(skb))) 2702 return 0; 2703 return skb_copy_ubufs(skb, gfp_mask); 2704 } 2705 2706 /** 2707 * __skb_queue_purge - empty a list 2708 * @list: list to empty 2709 * 2710 * Delete all buffers on an &sk_buff list. Each buffer is removed from 2711 * the list and one reference dropped. This function does not take the 2712 * list lock and the caller must hold the relevant locks to use it. 2713 */ 2714 static inline void __skb_queue_purge(struct sk_buff_head *list) 2715 { 2716 struct sk_buff *skb; 2717 while ((skb = __skb_dequeue(list)) != NULL) 2718 kfree_skb(skb); 2719 } 2720 void skb_queue_purge(struct sk_buff_head *list); 2721 2722 unsigned int skb_rbtree_purge(struct rb_root *root); 2723 2724 void *netdev_alloc_frag(unsigned int fragsz); 2725 2726 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 2727 gfp_t gfp_mask); 2728 2729 /** 2730 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 2731 * @dev: network device to receive on 2732 * @length: length to allocate 2733 * 2734 * Allocate a new &sk_buff and assign it a usage count of one. The 2735 * buffer has unspecified headroom built in. Users should allocate 2736 * the headroom they think they need without accounting for the 2737 * built in space. The built in space is used for optimisations. 2738 * 2739 * %NULL is returned if there is no free memory. Although this function 2740 * allocates memory it can be called from an interrupt. 2741 */ 2742 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 2743 unsigned int length) 2744 { 2745 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 2746 } 2747 2748 /* legacy helper around __netdev_alloc_skb() */ 2749 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 2750 gfp_t gfp_mask) 2751 { 2752 return __netdev_alloc_skb(NULL, length, gfp_mask); 2753 } 2754 2755 /* legacy helper around netdev_alloc_skb() */ 2756 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 2757 { 2758 return netdev_alloc_skb(NULL, length); 2759 } 2760 2761 2762 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 2763 unsigned int length, gfp_t gfp) 2764 { 2765 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 2766 2767 if (NET_IP_ALIGN && skb) 2768 skb_reserve(skb, NET_IP_ALIGN); 2769 return skb; 2770 } 2771 2772 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 2773 unsigned int length) 2774 { 2775 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 2776 } 2777 2778 static inline void skb_free_frag(void *addr) 2779 { 2780 page_frag_free(addr); 2781 } 2782 2783 void *napi_alloc_frag(unsigned int fragsz); 2784 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, 2785 unsigned int length, gfp_t gfp_mask); 2786 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, 2787 unsigned int length) 2788 { 2789 return __napi_alloc_skb(napi, length, GFP_ATOMIC); 2790 } 2791 void napi_consume_skb(struct sk_buff *skb, int budget); 2792 2793 void __kfree_skb_flush(void); 2794 void __kfree_skb_defer(struct sk_buff *skb); 2795 2796 /** 2797 * __dev_alloc_pages - allocate page for network Rx 2798 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 2799 * @order: size of the allocation 2800 * 2801 * Allocate a new page. 2802 * 2803 * %NULL is returned if there is no free memory. 2804 */ 2805 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask, 2806 unsigned int order) 2807 { 2808 /* This piece of code contains several assumptions. 2809 * 1. This is for device Rx, therefor a cold page is preferred. 2810 * 2. The expectation is the user wants a compound page. 2811 * 3. If requesting a order 0 page it will not be compound 2812 * due to the check to see if order has a value in prep_new_page 2813 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to 2814 * code in gfp_to_alloc_flags that should be enforcing this. 2815 */ 2816 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC; 2817 2818 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 2819 } 2820 2821 static inline struct page *dev_alloc_pages(unsigned int order) 2822 { 2823 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order); 2824 } 2825 2826 /** 2827 * __dev_alloc_page - allocate a page for network Rx 2828 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 2829 * 2830 * Allocate a new page. 2831 * 2832 * %NULL is returned if there is no free memory. 2833 */ 2834 static inline struct page *__dev_alloc_page(gfp_t gfp_mask) 2835 { 2836 return __dev_alloc_pages(gfp_mask, 0); 2837 } 2838 2839 static inline struct page *dev_alloc_page(void) 2840 { 2841 return dev_alloc_pages(0); 2842 } 2843 2844 /** 2845 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 2846 * @page: The page that was allocated from skb_alloc_page 2847 * @skb: The skb that may need pfmemalloc set 2848 */ 2849 static inline void skb_propagate_pfmemalloc(struct page *page, 2850 struct sk_buff *skb) 2851 { 2852 if (page_is_pfmemalloc(page)) 2853 skb->pfmemalloc = true; 2854 } 2855 2856 /** 2857 * skb_frag_page - retrieve the page referred to by a paged fragment 2858 * @frag: the paged fragment 2859 * 2860 * Returns the &struct page associated with @frag. 2861 */ 2862 static inline struct page *skb_frag_page(const skb_frag_t *frag) 2863 { 2864 return frag->page.p; 2865 } 2866 2867 /** 2868 * __skb_frag_ref - take an addition reference on a paged fragment. 2869 * @frag: the paged fragment 2870 * 2871 * Takes an additional reference on the paged fragment @frag. 2872 */ 2873 static inline void __skb_frag_ref(skb_frag_t *frag) 2874 { 2875 get_page(skb_frag_page(frag)); 2876 } 2877 2878 /** 2879 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 2880 * @skb: the buffer 2881 * @f: the fragment offset. 2882 * 2883 * Takes an additional reference on the @f'th paged fragment of @skb. 2884 */ 2885 static inline void skb_frag_ref(struct sk_buff *skb, int f) 2886 { 2887 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 2888 } 2889 2890 /** 2891 * __skb_frag_unref - release a reference on a paged fragment. 2892 * @frag: the paged fragment 2893 * 2894 * Releases a reference on the paged fragment @frag. 2895 */ 2896 static inline void __skb_frag_unref(skb_frag_t *frag) 2897 { 2898 put_page(skb_frag_page(frag)); 2899 } 2900 2901 /** 2902 * skb_frag_unref - release a reference on a paged fragment of an skb. 2903 * @skb: the buffer 2904 * @f: the fragment offset 2905 * 2906 * Releases a reference on the @f'th paged fragment of @skb. 2907 */ 2908 static inline void skb_frag_unref(struct sk_buff *skb, int f) 2909 { 2910 __skb_frag_unref(&skb_shinfo(skb)->frags[f]); 2911 } 2912 2913 /** 2914 * skb_frag_address - gets the address of the data contained in a paged fragment 2915 * @frag: the paged fragment buffer 2916 * 2917 * Returns the address of the data within @frag. The page must already 2918 * be mapped. 2919 */ 2920 static inline void *skb_frag_address(const skb_frag_t *frag) 2921 { 2922 return page_address(skb_frag_page(frag)) + frag->page_offset; 2923 } 2924 2925 /** 2926 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 2927 * @frag: the paged fragment buffer 2928 * 2929 * Returns the address of the data within @frag. Checks that the page 2930 * is mapped and returns %NULL otherwise. 2931 */ 2932 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 2933 { 2934 void *ptr = page_address(skb_frag_page(frag)); 2935 if (unlikely(!ptr)) 2936 return NULL; 2937 2938 return ptr + frag->page_offset; 2939 } 2940 2941 /** 2942 * __skb_frag_set_page - sets the page contained in a paged fragment 2943 * @frag: the paged fragment 2944 * @page: the page to set 2945 * 2946 * Sets the fragment @frag to contain @page. 2947 */ 2948 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page) 2949 { 2950 frag->page.p = page; 2951 } 2952 2953 /** 2954 * skb_frag_set_page - sets the page contained in a paged fragment of an skb 2955 * @skb: the buffer 2956 * @f: the fragment offset 2957 * @page: the page to set 2958 * 2959 * Sets the @f'th fragment of @skb to contain @page. 2960 */ 2961 static inline void skb_frag_set_page(struct sk_buff *skb, int f, 2962 struct page *page) 2963 { 2964 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page); 2965 } 2966 2967 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 2968 2969 /** 2970 * skb_frag_dma_map - maps a paged fragment via the DMA API 2971 * @dev: the device to map the fragment to 2972 * @frag: the paged fragment to map 2973 * @offset: the offset within the fragment (starting at the 2974 * fragment's own offset) 2975 * @size: the number of bytes to map 2976 * @dir: the direction of the mapping (``PCI_DMA_*``) 2977 * 2978 * Maps the page associated with @frag to @device. 2979 */ 2980 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 2981 const skb_frag_t *frag, 2982 size_t offset, size_t size, 2983 enum dma_data_direction dir) 2984 { 2985 return dma_map_page(dev, skb_frag_page(frag), 2986 frag->page_offset + offset, size, dir); 2987 } 2988 2989 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 2990 gfp_t gfp_mask) 2991 { 2992 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 2993 } 2994 2995 2996 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb, 2997 gfp_t gfp_mask) 2998 { 2999 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true); 3000 } 3001 3002 3003 /** 3004 * skb_clone_writable - is the header of a clone writable 3005 * @skb: buffer to check 3006 * @len: length up to which to write 3007 * 3008 * Returns true if modifying the header part of the cloned buffer 3009 * does not requires the data to be copied. 3010 */ 3011 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 3012 { 3013 return !skb_header_cloned(skb) && 3014 skb_headroom(skb) + len <= skb->hdr_len; 3015 } 3016 3017 static inline int skb_try_make_writable(struct sk_buff *skb, 3018 unsigned int write_len) 3019 { 3020 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) && 3021 pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 3022 } 3023 3024 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 3025 int cloned) 3026 { 3027 int delta = 0; 3028 3029 if (headroom > skb_headroom(skb)) 3030 delta = headroom - skb_headroom(skb); 3031 3032 if (delta || cloned) 3033 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 3034 GFP_ATOMIC); 3035 return 0; 3036 } 3037 3038 /** 3039 * skb_cow - copy header of skb when it is required 3040 * @skb: buffer to cow 3041 * @headroom: needed headroom 3042 * 3043 * If the skb passed lacks sufficient headroom or its data part 3044 * is shared, data is reallocated. If reallocation fails, an error 3045 * is returned and original skb is not changed. 3046 * 3047 * The result is skb with writable area skb->head...skb->tail 3048 * and at least @headroom of space at head. 3049 */ 3050 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 3051 { 3052 return __skb_cow(skb, headroom, skb_cloned(skb)); 3053 } 3054 3055 /** 3056 * skb_cow_head - skb_cow but only making the head writable 3057 * @skb: buffer to cow 3058 * @headroom: needed headroom 3059 * 3060 * This function is identical to skb_cow except that we replace the 3061 * skb_cloned check by skb_header_cloned. It should be used when 3062 * you only need to push on some header and do not need to modify 3063 * the data. 3064 */ 3065 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 3066 { 3067 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 3068 } 3069 3070 /** 3071 * skb_padto - pad an skbuff up to a minimal size 3072 * @skb: buffer to pad 3073 * @len: minimal length 3074 * 3075 * Pads up a buffer to ensure the trailing bytes exist and are 3076 * blanked. If the buffer already contains sufficient data it 3077 * is untouched. Otherwise it is extended. Returns zero on 3078 * success. The skb is freed on error. 3079 */ 3080 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 3081 { 3082 unsigned int size = skb->len; 3083 if (likely(size >= len)) 3084 return 0; 3085 return skb_pad(skb, len - size); 3086 } 3087 3088 /** 3089 * __skb_put_padto - increase size and pad an skbuff up to a minimal size 3090 * @skb: buffer to pad 3091 * @len: minimal length 3092 * @free_on_error: free buffer on error 3093 * 3094 * Pads up a buffer to ensure the trailing bytes exist and are 3095 * blanked. If the buffer already contains sufficient data it 3096 * is untouched. Otherwise it is extended. Returns zero on 3097 * success. The skb is freed on error if @free_on_error is true. 3098 */ 3099 static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len, 3100 bool free_on_error) 3101 { 3102 unsigned int size = skb->len; 3103 3104 if (unlikely(size < len)) { 3105 len -= size; 3106 if (__skb_pad(skb, len, free_on_error)) 3107 return -ENOMEM; 3108 __skb_put(skb, len); 3109 } 3110 return 0; 3111 } 3112 3113 /** 3114 * skb_put_padto - increase size and pad an skbuff up to a minimal size 3115 * @skb: buffer to pad 3116 * @len: minimal length 3117 * 3118 * Pads up a buffer to ensure the trailing bytes exist and are 3119 * blanked. If the buffer already contains sufficient data it 3120 * is untouched. Otherwise it is extended. Returns zero on 3121 * success. The skb is freed on error. 3122 */ 3123 static inline int skb_put_padto(struct sk_buff *skb, unsigned int len) 3124 { 3125 return __skb_put_padto(skb, len, true); 3126 } 3127 3128 static inline int skb_add_data(struct sk_buff *skb, 3129 struct iov_iter *from, int copy) 3130 { 3131 const int off = skb->len; 3132 3133 if (skb->ip_summed == CHECKSUM_NONE) { 3134 __wsum csum = 0; 3135 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy, 3136 &csum, from)) { 3137 skb->csum = csum_block_add(skb->csum, csum, off); 3138 return 0; 3139 } 3140 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from)) 3141 return 0; 3142 3143 __skb_trim(skb, off); 3144 return -EFAULT; 3145 } 3146 3147 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 3148 const struct page *page, int off) 3149 { 3150 if (skb_zcopy(skb)) 3151 return false; 3152 if (i) { 3153 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; 3154 3155 return page == skb_frag_page(frag) && 3156 off == frag->page_offset + skb_frag_size(frag); 3157 } 3158 return false; 3159 } 3160 3161 static inline int __skb_linearize(struct sk_buff *skb) 3162 { 3163 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 3164 } 3165 3166 /** 3167 * skb_linearize - convert paged skb to linear one 3168 * @skb: buffer to linarize 3169 * 3170 * If there is no free memory -ENOMEM is returned, otherwise zero 3171 * is returned and the old skb data released. 3172 */ 3173 static inline int skb_linearize(struct sk_buff *skb) 3174 { 3175 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 3176 } 3177 3178 /** 3179 * skb_has_shared_frag - can any frag be overwritten 3180 * @skb: buffer to test 3181 * 3182 * Return true if the skb has at least one frag that might be modified 3183 * by an external entity (as in vmsplice()/sendfile()) 3184 */ 3185 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 3186 { 3187 return skb_is_nonlinear(skb) && 3188 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; 3189 } 3190 3191 /** 3192 * skb_linearize_cow - make sure skb is linear and writable 3193 * @skb: buffer to process 3194 * 3195 * If there is no free memory -ENOMEM is returned, otherwise zero 3196 * is returned and the old skb data released. 3197 */ 3198 static inline int skb_linearize_cow(struct sk_buff *skb) 3199 { 3200 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 3201 __skb_linearize(skb) : 0; 3202 } 3203 3204 static __always_inline void 3205 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3206 unsigned int off) 3207 { 3208 if (skb->ip_summed == CHECKSUM_COMPLETE) 3209 skb->csum = csum_block_sub(skb->csum, 3210 csum_partial(start, len, 0), off); 3211 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3212 skb_checksum_start_offset(skb) < 0) 3213 skb->ip_summed = CHECKSUM_NONE; 3214 } 3215 3216 /** 3217 * skb_postpull_rcsum - update checksum for received skb after pull 3218 * @skb: buffer to update 3219 * @start: start of data before pull 3220 * @len: length of data pulled 3221 * 3222 * After doing a pull on a received packet, you need to call this to 3223 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 3224 * CHECKSUM_NONE so that it can be recomputed from scratch. 3225 */ 3226 static inline void skb_postpull_rcsum(struct sk_buff *skb, 3227 const void *start, unsigned int len) 3228 { 3229 __skb_postpull_rcsum(skb, start, len, 0); 3230 } 3231 3232 static __always_inline void 3233 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3234 unsigned int off) 3235 { 3236 if (skb->ip_summed == CHECKSUM_COMPLETE) 3237 skb->csum = csum_block_add(skb->csum, 3238 csum_partial(start, len, 0), off); 3239 } 3240 3241 /** 3242 * skb_postpush_rcsum - update checksum for received skb after push 3243 * @skb: buffer to update 3244 * @start: start of data after push 3245 * @len: length of data pushed 3246 * 3247 * After doing a push on a received packet, you need to call this to 3248 * update the CHECKSUM_COMPLETE checksum. 3249 */ 3250 static inline void skb_postpush_rcsum(struct sk_buff *skb, 3251 const void *start, unsigned int len) 3252 { 3253 __skb_postpush_rcsum(skb, start, len, 0); 3254 } 3255 3256 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 3257 3258 /** 3259 * skb_push_rcsum - push skb and update receive checksum 3260 * @skb: buffer to update 3261 * @len: length of data pulled 3262 * 3263 * This function performs an skb_push on the packet and updates 3264 * the CHECKSUM_COMPLETE checksum. It should be used on 3265 * receive path processing instead of skb_push unless you know 3266 * that the checksum difference is zero (e.g., a valid IP header) 3267 * or you are setting ip_summed to CHECKSUM_NONE. 3268 */ 3269 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len) 3270 { 3271 skb_push(skb, len); 3272 skb_postpush_rcsum(skb, skb->data, len); 3273 return skb->data; 3274 } 3275 3276 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len); 3277 /** 3278 * pskb_trim_rcsum - trim received skb and update checksum 3279 * @skb: buffer to trim 3280 * @len: new length 3281 * 3282 * This is exactly the same as pskb_trim except that it ensures the 3283 * checksum of received packets are still valid after the operation. 3284 * It can change skb pointers. 3285 */ 3286 3287 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3288 { 3289 if (likely(len >= skb->len)) 3290 return 0; 3291 return pskb_trim_rcsum_slow(skb, len); 3292 } 3293 3294 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3295 { 3296 if (skb->ip_summed == CHECKSUM_COMPLETE) 3297 skb->ip_summed = CHECKSUM_NONE; 3298 __skb_trim(skb, len); 3299 return 0; 3300 } 3301 3302 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len) 3303 { 3304 if (skb->ip_summed == CHECKSUM_COMPLETE) 3305 skb->ip_summed = CHECKSUM_NONE; 3306 return __skb_grow(skb, len); 3307 } 3308 3309 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode) 3310 #define skb_rb_first(root) rb_to_skb(rb_first(root)) 3311 #define skb_rb_last(root) rb_to_skb(rb_last(root)) 3312 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode)) 3313 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode)) 3314 3315 #define skb_queue_walk(queue, skb) \ 3316 for (skb = (queue)->next; \ 3317 skb != (struct sk_buff *)(queue); \ 3318 skb = skb->next) 3319 3320 #define skb_queue_walk_safe(queue, skb, tmp) \ 3321 for (skb = (queue)->next, tmp = skb->next; \ 3322 skb != (struct sk_buff *)(queue); \ 3323 skb = tmp, tmp = skb->next) 3324 3325 #define skb_queue_walk_from(queue, skb) \ 3326 for (; skb != (struct sk_buff *)(queue); \ 3327 skb = skb->next) 3328 3329 #define skb_rbtree_walk(skb, root) \ 3330 for (skb = skb_rb_first(root); skb != NULL; \ 3331 skb = skb_rb_next(skb)) 3332 3333 #define skb_rbtree_walk_from(skb) \ 3334 for (; skb != NULL; \ 3335 skb = skb_rb_next(skb)) 3336 3337 #define skb_rbtree_walk_from_safe(skb, tmp) \ 3338 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \ 3339 skb = tmp) 3340 3341 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 3342 for (tmp = skb->next; \ 3343 skb != (struct sk_buff *)(queue); \ 3344 skb = tmp, tmp = skb->next) 3345 3346 #define skb_queue_reverse_walk(queue, skb) \ 3347 for (skb = (queue)->prev; \ 3348 skb != (struct sk_buff *)(queue); \ 3349 skb = skb->prev) 3350 3351 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 3352 for (skb = (queue)->prev, tmp = skb->prev; \ 3353 skb != (struct sk_buff *)(queue); \ 3354 skb = tmp, tmp = skb->prev) 3355 3356 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 3357 for (tmp = skb->prev; \ 3358 skb != (struct sk_buff *)(queue); \ 3359 skb = tmp, tmp = skb->prev) 3360 3361 static inline bool skb_has_frag_list(const struct sk_buff *skb) 3362 { 3363 return skb_shinfo(skb)->frag_list != NULL; 3364 } 3365 3366 static inline void skb_frag_list_init(struct sk_buff *skb) 3367 { 3368 skb_shinfo(skb)->frag_list = NULL; 3369 } 3370 3371 #define skb_walk_frags(skb, iter) \ 3372 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 3373 3374 3375 int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p, 3376 const struct sk_buff *skb); 3377 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 3378 struct sk_buff_head *queue, 3379 unsigned int flags, 3380 void (*destructor)(struct sock *sk, 3381 struct sk_buff *skb), 3382 int *off, int *err, 3383 struct sk_buff **last); 3384 struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned flags, 3385 void (*destructor)(struct sock *sk, 3386 struct sk_buff *skb), 3387 int *off, int *err, 3388 struct sk_buff **last); 3389 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, 3390 void (*destructor)(struct sock *sk, 3391 struct sk_buff *skb), 3392 int *off, int *err); 3393 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, 3394 int *err); 3395 __poll_t datagram_poll(struct file *file, struct socket *sock, 3396 struct poll_table_struct *wait); 3397 int skb_copy_datagram_iter(const struct sk_buff *from, int offset, 3398 struct iov_iter *to, int size); 3399 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 3400 struct msghdr *msg, int size) 3401 { 3402 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size); 3403 } 3404 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 3405 struct msghdr *msg); 3406 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, 3407 struct iov_iter *to, int len, 3408 struct ahash_request *hash); 3409 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, 3410 struct iov_iter *from, int len); 3411 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 3412 void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 3413 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len); 3414 static inline void skb_free_datagram_locked(struct sock *sk, 3415 struct sk_buff *skb) 3416 { 3417 __skb_free_datagram_locked(sk, skb, 0); 3418 } 3419 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 3420 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 3421 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 3422 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 3423 int len, __wsum csum); 3424 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, 3425 struct pipe_inode_info *pipe, unsigned int len, 3426 unsigned int flags); 3427 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, 3428 int len); 3429 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 3430 unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 3431 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, 3432 int len, int hlen); 3433 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 3434 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 3435 void skb_scrub_packet(struct sk_buff *skb, bool xnet); 3436 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu); 3437 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); 3438 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 3439 struct sk_buff *skb_vlan_untag(struct sk_buff *skb); 3440 int skb_ensure_writable(struct sk_buff *skb, int write_len); 3441 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); 3442 int skb_vlan_pop(struct sk_buff *skb); 3443 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); 3444 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy, 3445 gfp_t gfp); 3446 3447 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len) 3448 { 3449 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT; 3450 } 3451 3452 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len) 3453 { 3454 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 3455 } 3456 3457 struct skb_checksum_ops { 3458 __wsum (*update)(const void *mem, int len, __wsum wsum); 3459 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 3460 }; 3461 3462 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly; 3463 3464 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 3465 __wsum csum, const struct skb_checksum_ops *ops); 3466 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 3467 __wsum csum); 3468 3469 static inline void * __must_check 3470 __skb_header_pointer(const struct sk_buff *skb, int offset, 3471 int len, void *data, int hlen, void *buffer) 3472 { 3473 if (hlen - offset >= len) 3474 return data + offset; 3475 3476 if (!skb || 3477 skb_copy_bits(skb, offset, buffer, len) < 0) 3478 return NULL; 3479 3480 return buffer; 3481 } 3482 3483 static inline void * __must_check 3484 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) 3485 { 3486 return __skb_header_pointer(skb, offset, len, skb->data, 3487 skb_headlen(skb), buffer); 3488 } 3489 3490 /** 3491 * skb_needs_linearize - check if we need to linearize a given skb 3492 * depending on the given device features. 3493 * @skb: socket buffer to check 3494 * @features: net device features 3495 * 3496 * Returns true if either: 3497 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 3498 * 2. skb is fragmented and the device does not support SG. 3499 */ 3500 static inline bool skb_needs_linearize(struct sk_buff *skb, 3501 netdev_features_t features) 3502 { 3503 return skb_is_nonlinear(skb) && 3504 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 3505 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 3506 } 3507 3508 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 3509 void *to, 3510 const unsigned int len) 3511 { 3512 memcpy(to, skb->data, len); 3513 } 3514 3515 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 3516 const int offset, void *to, 3517 const unsigned int len) 3518 { 3519 memcpy(to, skb->data + offset, len); 3520 } 3521 3522 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 3523 const void *from, 3524 const unsigned int len) 3525 { 3526 memcpy(skb->data, from, len); 3527 } 3528 3529 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 3530 const int offset, 3531 const void *from, 3532 const unsigned int len) 3533 { 3534 memcpy(skb->data + offset, from, len); 3535 } 3536 3537 void skb_init(void); 3538 3539 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 3540 { 3541 return skb->tstamp; 3542 } 3543 3544 /** 3545 * skb_get_timestamp - get timestamp from a skb 3546 * @skb: skb to get stamp from 3547 * @stamp: pointer to struct __kernel_old_timeval to store stamp in 3548 * 3549 * Timestamps are stored in the skb as offsets to a base timestamp. 3550 * This function converts the offset back to a struct timeval and stores 3551 * it in stamp. 3552 */ 3553 static inline void skb_get_timestamp(const struct sk_buff *skb, 3554 struct __kernel_old_timeval *stamp) 3555 { 3556 *stamp = ns_to_kernel_old_timeval(skb->tstamp); 3557 } 3558 3559 static inline void skb_get_new_timestamp(const struct sk_buff *skb, 3560 struct __kernel_sock_timeval *stamp) 3561 { 3562 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 3563 3564 stamp->tv_sec = ts.tv_sec; 3565 stamp->tv_usec = ts.tv_nsec / 1000; 3566 } 3567 3568 static inline void skb_get_timestampns(const struct sk_buff *skb, 3569 struct timespec *stamp) 3570 { 3571 *stamp = ktime_to_timespec(skb->tstamp); 3572 } 3573 3574 static inline void skb_get_new_timestampns(const struct sk_buff *skb, 3575 struct __kernel_timespec *stamp) 3576 { 3577 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 3578 3579 stamp->tv_sec = ts.tv_sec; 3580 stamp->tv_nsec = ts.tv_nsec; 3581 } 3582 3583 static inline void __net_timestamp(struct sk_buff *skb) 3584 { 3585 skb->tstamp = ktime_get_real(); 3586 } 3587 3588 static inline ktime_t net_timedelta(ktime_t t) 3589 { 3590 return ktime_sub(ktime_get_real(), t); 3591 } 3592 3593 static inline ktime_t net_invalid_timestamp(void) 3594 { 3595 return 0; 3596 } 3597 3598 static inline u8 skb_metadata_len(const struct sk_buff *skb) 3599 { 3600 return skb_shinfo(skb)->meta_len; 3601 } 3602 3603 static inline void *skb_metadata_end(const struct sk_buff *skb) 3604 { 3605 return skb_mac_header(skb); 3606 } 3607 3608 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, 3609 const struct sk_buff *skb_b, 3610 u8 meta_len) 3611 { 3612 const void *a = skb_metadata_end(skb_a); 3613 const void *b = skb_metadata_end(skb_b); 3614 /* Using more efficient varaiant than plain call to memcmp(). */ 3615 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 3616 u64 diffs = 0; 3617 3618 switch (meta_len) { 3619 #define __it(x, op) (x -= sizeof(u##op)) 3620 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op)) 3621 case 32: diffs |= __it_diff(a, b, 64); 3622 /* fall through */ 3623 case 24: diffs |= __it_diff(a, b, 64); 3624 /* fall through */ 3625 case 16: diffs |= __it_diff(a, b, 64); 3626 /* fall through */ 3627 case 8: diffs |= __it_diff(a, b, 64); 3628 break; 3629 case 28: diffs |= __it_diff(a, b, 64); 3630 /* fall through */ 3631 case 20: diffs |= __it_diff(a, b, 64); 3632 /* fall through */ 3633 case 12: diffs |= __it_diff(a, b, 64); 3634 /* fall through */ 3635 case 4: diffs |= __it_diff(a, b, 32); 3636 break; 3637 } 3638 return diffs; 3639 #else 3640 return memcmp(a - meta_len, b - meta_len, meta_len); 3641 #endif 3642 } 3643 3644 static inline bool skb_metadata_differs(const struct sk_buff *skb_a, 3645 const struct sk_buff *skb_b) 3646 { 3647 u8 len_a = skb_metadata_len(skb_a); 3648 u8 len_b = skb_metadata_len(skb_b); 3649 3650 if (!(len_a | len_b)) 3651 return false; 3652 3653 return len_a != len_b ? 3654 true : __skb_metadata_differs(skb_a, skb_b, len_a); 3655 } 3656 3657 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len) 3658 { 3659 skb_shinfo(skb)->meta_len = meta_len; 3660 } 3661 3662 static inline void skb_metadata_clear(struct sk_buff *skb) 3663 { 3664 skb_metadata_set(skb, 0); 3665 } 3666 3667 struct sk_buff *skb_clone_sk(struct sk_buff *skb); 3668 3669 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 3670 3671 void skb_clone_tx_timestamp(struct sk_buff *skb); 3672 bool skb_defer_rx_timestamp(struct sk_buff *skb); 3673 3674 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 3675 3676 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 3677 { 3678 } 3679 3680 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 3681 { 3682 return false; 3683 } 3684 3685 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 3686 3687 /** 3688 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 3689 * 3690 * PHY drivers may accept clones of transmitted packets for 3691 * timestamping via their phy_driver.txtstamp method. These drivers 3692 * must call this function to return the skb back to the stack with a 3693 * timestamp. 3694 * 3695 * @skb: clone of the the original outgoing packet 3696 * @hwtstamps: hardware time stamps 3697 * 3698 */ 3699 void skb_complete_tx_timestamp(struct sk_buff *skb, 3700 struct skb_shared_hwtstamps *hwtstamps); 3701 3702 void __skb_tstamp_tx(struct sk_buff *orig_skb, 3703 struct skb_shared_hwtstamps *hwtstamps, 3704 struct sock *sk, int tstype); 3705 3706 /** 3707 * skb_tstamp_tx - queue clone of skb with send time stamps 3708 * @orig_skb: the original outgoing packet 3709 * @hwtstamps: hardware time stamps, may be NULL if not available 3710 * 3711 * If the skb has a socket associated, then this function clones the 3712 * skb (thus sharing the actual data and optional structures), stores 3713 * the optional hardware time stamping information (if non NULL) or 3714 * generates a software time stamp (otherwise), then queues the clone 3715 * to the error queue of the socket. Errors are silently ignored. 3716 */ 3717 void skb_tstamp_tx(struct sk_buff *orig_skb, 3718 struct skb_shared_hwtstamps *hwtstamps); 3719 3720 /** 3721 * skb_tx_timestamp() - Driver hook for transmit timestamping 3722 * 3723 * Ethernet MAC Drivers should call this function in their hard_xmit() 3724 * function immediately before giving the sk_buff to the MAC hardware. 3725 * 3726 * Specifically, one should make absolutely sure that this function is 3727 * called before TX completion of this packet can trigger. Otherwise 3728 * the packet could potentially already be freed. 3729 * 3730 * @skb: A socket buffer. 3731 */ 3732 static inline void skb_tx_timestamp(struct sk_buff *skb) 3733 { 3734 skb_clone_tx_timestamp(skb); 3735 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) 3736 skb_tstamp_tx(skb, NULL); 3737 } 3738 3739 /** 3740 * skb_complete_wifi_ack - deliver skb with wifi status 3741 * 3742 * @skb: the original outgoing packet 3743 * @acked: ack status 3744 * 3745 */ 3746 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 3747 3748 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 3749 __sum16 __skb_checksum_complete(struct sk_buff *skb); 3750 3751 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 3752 { 3753 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) || 3754 skb->csum_valid || 3755 (skb->ip_summed == CHECKSUM_PARTIAL && 3756 skb_checksum_start_offset(skb) >= 0)); 3757 } 3758 3759 /** 3760 * skb_checksum_complete - Calculate checksum of an entire packet 3761 * @skb: packet to process 3762 * 3763 * This function calculates the checksum over the entire packet plus 3764 * the value of skb->csum. The latter can be used to supply the 3765 * checksum of a pseudo header as used by TCP/UDP. It returns the 3766 * checksum. 3767 * 3768 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 3769 * this function can be used to verify that checksum on received 3770 * packets. In that case the function should return zero if the 3771 * checksum is correct. In particular, this function will return zero 3772 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 3773 * hardware has already verified the correctness of the checksum. 3774 */ 3775 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 3776 { 3777 return skb_csum_unnecessary(skb) ? 3778 0 : __skb_checksum_complete(skb); 3779 } 3780 3781 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb) 3782 { 3783 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3784 if (skb->csum_level == 0) 3785 skb->ip_summed = CHECKSUM_NONE; 3786 else 3787 skb->csum_level--; 3788 } 3789 } 3790 3791 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) 3792 { 3793 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3794 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 3795 skb->csum_level++; 3796 } else if (skb->ip_summed == CHECKSUM_NONE) { 3797 skb->ip_summed = CHECKSUM_UNNECESSARY; 3798 skb->csum_level = 0; 3799 } 3800 } 3801 3802 /* Check if we need to perform checksum complete validation. 3803 * 3804 * Returns true if checksum complete is needed, false otherwise 3805 * (either checksum is unnecessary or zero checksum is allowed). 3806 */ 3807 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, 3808 bool zero_okay, 3809 __sum16 check) 3810 { 3811 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) { 3812 skb->csum_valid = 1; 3813 __skb_decr_checksum_unnecessary(skb); 3814 return false; 3815 } 3816 3817 return true; 3818 } 3819 3820 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly 3821 * in checksum_init. 3822 */ 3823 #define CHECKSUM_BREAK 76 3824 3825 /* Unset checksum-complete 3826 * 3827 * Unset checksum complete can be done when packet is being modified 3828 * (uncompressed for instance) and checksum-complete value is 3829 * invalidated. 3830 */ 3831 static inline void skb_checksum_complete_unset(struct sk_buff *skb) 3832 { 3833 if (skb->ip_summed == CHECKSUM_COMPLETE) 3834 skb->ip_summed = CHECKSUM_NONE; 3835 } 3836 3837 /* Validate (init) checksum based on checksum complete. 3838 * 3839 * Return values: 3840 * 0: checksum is validated or try to in skb_checksum_complete. In the latter 3841 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo 3842 * checksum is stored in skb->csum for use in __skb_checksum_complete 3843 * non-zero: value of invalid checksum 3844 * 3845 */ 3846 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, 3847 bool complete, 3848 __wsum psum) 3849 { 3850 if (skb->ip_summed == CHECKSUM_COMPLETE) { 3851 if (!csum_fold(csum_add(psum, skb->csum))) { 3852 skb->csum_valid = 1; 3853 return 0; 3854 } 3855 } 3856 3857 skb->csum = psum; 3858 3859 if (complete || skb->len <= CHECKSUM_BREAK) { 3860 __sum16 csum; 3861 3862 csum = __skb_checksum_complete(skb); 3863 skb->csum_valid = !csum; 3864 return csum; 3865 } 3866 3867 return 0; 3868 } 3869 3870 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) 3871 { 3872 return 0; 3873 } 3874 3875 /* Perform checksum validate (init). Note that this is a macro since we only 3876 * want to calculate the pseudo header which is an input function if necessary. 3877 * First we try to validate without any computation (checksum unnecessary) and 3878 * then calculate based on checksum complete calling the function to compute 3879 * pseudo header. 3880 * 3881 * Return values: 3882 * 0: checksum is validated or try to in skb_checksum_complete 3883 * non-zero: value of invalid checksum 3884 */ 3885 #define __skb_checksum_validate(skb, proto, complete, \ 3886 zero_okay, check, compute_pseudo) \ 3887 ({ \ 3888 __sum16 __ret = 0; \ 3889 skb->csum_valid = 0; \ 3890 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ 3891 __ret = __skb_checksum_validate_complete(skb, \ 3892 complete, compute_pseudo(skb, proto)); \ 3893 __ret; \ 3894 }) 3895 3896 #define skb_checksum_init(skb, proto, compute_pseudo) \ 3897 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) 3898 3899 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ 3900 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) 3901 3902 #define skb_checksum_validate(skb, proto, compute_pseudo) \ 3903 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) 3904 3905 #define skb_checksum_validate_zero_check(skb, proto, check, \ 3906 compute_pseudo) \ 3907 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo) 3908 3909 #define skb_checksum_simple_validate(skb) \ 3910 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) 3911 3912 static inline bool __skb_checksum_convert_check(struct sk_buff *skb) 3913 { 3914 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid); 3915 } 3916 3917 static inline void __skb_checksum_convert(struct sk_buff *skb, 3918 __sum16 check, __wsum pseudo) 3919 { 3920 skb->csum = ~pseudo; 3921 skb->ip_summed = CHECKSUM_COMPLETE; 3922 } 3923 3924 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \ 3925 do { \ 3926 if (__skb_checksum_convert_check(skb)) \ 3927 __skb_checksum_convert(skb, check, \ 3928 compute_pseudo(skb, proto)); \ 3929 } while (0) 3930 3931 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr, 3932 u16 start, u16 offset) 3933 { 3934 skb->ip_summed = CHECKSUM_PARTIAL; 3935 skb->csum_start = ((unsigned char *)ptr + start) - skb->head; 3936 skb->csum_offset = offset - start; 3937 } 3938 3939 /* Update skbuf and packet to reflect the remote checksum offload operation. 3940 * When called, ptr indicates the starting point for skb->csum when 3941 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete 3942 * here, skb_postpull_rcsum is done so skb->csum start is ptr. 3943 */ 3944 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr, 3945 int start, int offset, bool nopartial) 3946 { 3947 __wsum delta; 3948 3949 if (!nopartial) { 3950 skb_remcsum_adjust_partial(skb, ptr, start, offset); 3951 return; 3952 } 3953 3954 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) { 3955 __skb_checksum_complete(skb); 3956 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data); 3957 } 3958 3959 delta = remcsum_adjust(ptr, skb->csum, start, offset); 3960 3961 /* Adjust skb->csum since we changed the packet */ 3962 skb->csum = csum_add(skb->csum, delta); 3963 } 3964 3965 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb) 3966 { 3967 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 3968 return (void *)(skb->_nfct & SKB_NFCT_PTRMASK); 3969 #else 3970 return NULL; 3971 #endif 3972 } 3973 3974 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 3975 void nf_conntrack_destroy(struct nf_conntrack *nfct); 3976 static inline void nf_conntrack_put(struct nf_conntrack *nfct) 3977 { 3978 if (nfct && atomic_dec_and_test(&nfct->use)) 3979 nf_conntrack_destroy(nfct); 3980 } 3981 static inline void nf_conntrack_get(struct nf_conntrack *nfct) 3982 { 3983 if (nfct) 3984 atomic_inc(&nfct->use); 3985 } 3986 #endif 3987 3988 #ifdef CONFIG_SKB_EXTENSIONS 3989 enum skb_ext_id { 3990 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 3991 SKB_EXT_BRIDGE_NF, 3992 #endif 3993 #ifdef CONFIG_XFRM 3994 SKB_EXT_SEC_PATH, 3995 #endif 3996 SKB_EXT_NUM, /* must be last */ 3997 }; 3998 3999 /** 4000 * struct skb_ext - sk_buff extensions 4001 * @refcnt: 1 on allocation, deallocated on 0 4002 * @offset: offset to add to @data to obtain extension address 4003 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units 4004 * @data: start of extension data, variable sized 4005 * 4006 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows 4007 * to use 'u8' types while allowing up to 2kb worth of extension data. 4008 */ 4009 struct skb_ext { 4010 refcount_t refcnt; 4011 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */ 4012 u8 chunks; /* same */ 4013 char data[0] __aligned(8); 4014 }; 4015 4016 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); 4017 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); 4018 void __skb_ext_put(struct skb_ext *ext); 4019 4020 static inline void skb_ext_put(struct sk_buff *skb) 4021 { 4022 if (skb->active_extensions) 4023 __skb_ext_put(skb->extensions); 4024 } 4025 4026 static inline void __skb_ext_copy(struct sk_buff *dst, 4027 const struct sk_buff *src) 4028 { 4029 dst->active_extensions = src->active_extensions; 4030 4031 if (src->active_extensions) { 4032 struct skb_ext *ext = src->extensions; 4033 4034 refcount_inc(&ext->refcnt); 4035 dst->extensions = ext; 4036 } 4037 } 4038 4039 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src) 4040 { 4041 skb_ext_put(dst); 4042 __skb_ext_copy(dst, src); 4043 } 4044 4045 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i) 4046 { 4047 return !!ext->offset[i]; 4048 } 4049 4050 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id) 4051 { 4052 return skb->active_extensions & (1 << id); 4053 } 4054 4055 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) 4056 { 4057 if (skb_ext_exist(skb, id)) 4058 __skb_ext_del(skb, id); 4059 } 4060 4061 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id) 4062 { 4063 if (skb_ext_exist(skb, id)) { 4064 struct skb_ext *ext = skb->extensions; 4065 4066 return (void *)ext + (ext->offset[id] << 3); 4067 } 4068 4069 return NULL; 4070 } 4071 #else 4072 static inline void skb_ext_put(struct sk_buff *skb) {} 4073 static inline void skb_ext_del(struct sk_buff *skb, int unused) {} 4074 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {} 4075 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {} 4076 #endif /* CONFIG_SKB_EXTENSIONS */ 4077 4078 static inline void nf_reset(struct sk_buff *skb) 4079 { 4080 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4081 nf_conntrack_put(skb_nfct(skb)); 4082 skb->_nfct = 0; 4083 #endif 4084 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 4085 skb_ext_del(skb, SKB_EXT_BRIDGE_NF); 4086 #endif 4087 } 4088 4089 static inline void nf_reset_trace(struct sk_buff *skb) 4090 { 4091 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 4092 skb->nf_trace = 0; 4093 #endif 4094 } 4095 4096 static inline void ipvs_reset(struct sk_buff *skb) 4097 { 4098 #if IS_ENABLED(CONFIG_IP_VS) 4099 skb->ipvs_property = 0; 4100 #endif 4101 } 4102 4103 /* Note: This doesn't put any conntrack info in dst. */ 4104 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src, 4105 bool copy) 4106 { 4107 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4108 dst->_nfct = src->_nfct; 4109 nf_conntrack_get(skb_nfct(src)); 4110 #endif 4111 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 4112 if (copy) 4113 dst->nf_trace = src->nf_trace; 4114 #endif 4115 } 4116 4117 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 4118 { 4119 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4120 nf_conntrack_put(skb_nfct(dst)); 4121 #endif 4122 __nf_copy(dst, src, true); 4123 } 4124 4125 #ifdef CONFIG_NETWORK_SECMARK 4126 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4127 { 4128 to->secmark = from->secmark; 4129 } 4130 4131 static inline void skb_init_secmark(struct sk_buff *skb) 4132 { 4133 skb->secmark = 0; 4134 } 4135 #else 4136 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4137 { } 4138 4139 static inline void skb_init_secmark(struct sk_buff *skb) 4140 { } 4141 #endif 4142 4143 static inline int secpath_exists(const struct sk_buff *skb) 4144 { 4145 #ifdef CONFIG_XFRM 4146 return skb_ext_exist(skb, SKB_EXT_SEC_PATH); 4147 #else 4148 return 0; 4149 #endif 4150 } 4151 4152 static inline bool skb_irq_freeable(const struct sk_buff *skb) 4153 { 4154 return !skb->destructor && 4155 !secpath_exists(skb) && 4156 !skb_nfct(skb) && 4157 !skb->_skb_refdst && 4158 !skb_has_frag_list(skb); 4159 } 4160 4161 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 4162 { 4163 skb->queue_mapping = queue_mapping; 4164 } 4165 4166 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 4167 { 4168 return skb->queue_mapping; 4169 } 4170 4171 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 4172 { 4173 to->queue_mapping = from->queue_mapping; 4174 } 4175 4176 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 4177 { 4178 skb->queue_mapping = rx_queue + 1; 4179 } 4180 4181 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 4182 { 4183 return skb->queue_mapping - 1; 4184 } 4185 4186 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 4187 { 4188 return skb->queue_mapping != 0; 4189 } 4190 4191 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val) 4192 { 4193 skb->dst_pending_confirm = val; 4194 } 4195 4196 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb) 4197 { 4198 return skb->dst_pending_confirm != 0; 4199 } 4200 4201 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb) 4202 { 4203 #ifdef CONFIG_XFRM 4204 return skb_ext_find(skb, SKB_EXT_SEC_PATH); 4205 #else 4206 return NULL; 4207 #endif 4208 } 4209 4210 /* Keeps track of mac header offset relative to skb->head. 4211 * It is useful for TSO of Tunneling protocol. e.g. GRE. 4212 * For non-tunnel skb it points to skb_mac_header() and for 4213 * tunnel skb it points to outer mac header. 4214 * Keeps track of level of encapsulation of network headers. 4215 */ 4216 struct skb_gso_cb { 4217 union { 4218 int mac_offset; 4219 int data_offset; 4220 }; 4221 int encap_level; 4222 __wsum csum; 4223 __u16 csum_start; 4224 }; 4225 #define SKB_SGO_CB_OFFSET 32 4226 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET)) 4227 4228 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) 4229 { 4230 return (skb_mac_header(inner_skb) - inner_skb->head) - 4231 SKB_GSO_CB(inner_skb)->mac_offset; 4232 } 4233 4234 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) 4235 { 4236 int new_headroom, headroom; 4237 int ret; 4238 4239 headroom = skb_headroom(skb); 4240 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); 4241 if (ret) 4242 return ret; 4243 4244 new_headroom = skb_headroom(skb); 4245 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); 4246 return 0; 4247 } 4248 4249 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res) 4250 { 4251 /* Do not update partial checksums if remote checksum is enabled. */ 4252 if (skb->remcsum_offload) 4253 return; 4254 4255 SKB_GSO_CB(skb)->csum = res; 4256 SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head; 4257 } 4258 4259 /* Compute the checksum for a gso segment. First compute the checksum value 4260 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and 4261 * then add in skb->csum (checksum from csum_start to end of packet). 4262 * skb->csum and csum_start are then updated to reflect the checksum of the 4263 * resultant packet starting from the transport header-- the resultant checksum 4264 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo 4265 * header. 4266 */ 4267 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) 4268 { 4269 unsigned char *csum_start = skb_transport_header(skb); 4270 int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start; 4271 __wsum partial = SKB_GSO_CB(skb)->csum; 4272 4273 SKB_GSO_CB(skb)->csum = res; 4274 SKB_GSO_CB(skb)->csum_start = csum_start - skb->head; 4275 4276 return csum_fold(csum_partial(csum_start, plen, partial)); 4277 } 4278 4279 static inline bool skb_is_gso(const struct sk_buff *skb) 4280 { 4281 return skb_shinfo(skb)->gso_size; 4282 } 4283 4284 /* Note: Should be called only if skb_is_gso(skb) is true */ 4285 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 4286 { 4287 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 4288 } 4289 4290 /* Note: Should be called only if skb_is_gso(skb) is true */ 4291 static inline bool skb_is_gso_sctp(const struct sk_buff *skb) 4292 { 4293 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP; 4294 } 4295 4296 /* Note: Should be called only if skb_is_gso(skb) is true */ 4297 static inline bool skb_is_gso_tcp(const struct sk_buff *skb) 4298 { 4299 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6); 4300 } 4301 4302 static inline void skb_gso_reset(struct sk_buff *skb) 4303 { 4304 skb_shinfo(skb)->gso_size = 0; 4305 skb_shinfo(skb)->gso_segs = 0; 4306 skb_shinfo(skb)->gso_type = 0; 4307 } 4308 4309 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo, 4310 u16 increment) 4311 { 4312 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 4313 return; 4314 shinfo->gso_size += increment; 4315 } 4316 4317 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo, 4318 u16 decrement) 4319 { 4320 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 4321 return; 4322 shinfo->gso_size -= decrement; 4323 } 4324 4325 void __skb_warn_lro_forwarding(const struct sk_buff *skb); 4326 4327 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 4328 { 4329 /* LRO sets gso_size but not gso_type, whereas if GSO is really 4330 * wanted then gso_type will be set. */ 4331 const struct skb_shared_info *shinfo = skb_shinfo(skb); 4332 4333 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 4334 unlikely(shinfo->gso_type == 0)) { 4335 __skb_warn_lro_forwarding(skb); 4336 return true; 4337 } 4338 return false; 4339 } 4340 4341 static inline void skb_forward_csum(struct sk_buff *skb) 4342 { 4343 /* Unfortunately we don't support this one. Any brave souls? */ 4344 if (skb->ip_summed == CHECKSUM_COMPLETE) 4345 skb->ip_summed = CHECKSUM_NONE; 4346 } 4347 4348 /** 4349 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 4350 * @skb: skb to check 4351 * 4352 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 4353 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 4354 * use this helper, to document places where we make this assertion. 4355 */ 4356 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 4357 { 4358 #ifdef DEBUG 4359 BUG_ON(skb->ip_summed != CHECKSUM_NONE); 4360 #endif 4361 } 4362 4363 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 4364 4365 int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 4366 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, 4367 unsigned int transport_len, 4368 __sum16(*skb_chkf)(struct sk_buff *skb)); 4369 4370 /** 4371 * skb_head_is_locked - Determine if the skb->head is locked down 4372 * @skb: skb to check 4373 * 4374 * The head on skbs build around a head frag can be removed if they are 4375 * not cloned. This function returns true if the skb head is locked down 4376 * due to either being allocated via kmalloc, or by being a clone with 4377 * multiple references to the head. 4378 */ 4379 static inline bool skb_head_is_locked(const struct sk_buff *skb) 4380 { 4381 return !skb->head_frag || skb_cloned(skb); 4382 } 4383 4384 /* Local Checksum Offload. 4385 * Compute outer checksum based on the assumption that the 4386 * inner checksum will be offloaded later. 4387 * See Documentation/networking/checksum-offloads.rst for 4388 * explanation of how this works. 4389 * Fill in outer checksum adjustment (e.g. with sum of outer 4390 * pseudo-header) before calling. 4391 * Also ensure that inner checksum is in linear data area. 4392 */ 4393 static inline __wsum lco_csum(struct sk_buff *skb) 4394 { 4395 unsigned char *csum_start = skb_checksum_start(skb); 4396 unsigned char *l4_hdr = skb_transport_header(skb); 4397 __wsum partial; 4398 4399 /* Start with complement of inner checksum adjustment */ 4400 partial = ~csum_unfold(*(__force __sum16 *)(csum_start + 4401 skb->csum_offset)); 4402 4403 /* Add in checksum of our headers (incl. outer checksum 4404 * adjustment filled in by caller) and return result. 4405 */ 4406 return csum_partial(l4_hdr, csum_start - l4_hdr, partial); 4407 } 4408 4409 #endif /* __KERNEL__ */ 4410 #endif /* _LINUX_SKBUFF_H */ 4411