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, <[email protected]> 7 * Florian La Roche, <[email protected]> 8 */ 9 10 #ifndef _LINUX_SKBUFF_H 11 #define _LINUX_SKBUFF_H 12 13 #include <linux/kernel.h> 14 #include <linux/compiler.h> 15 #include <linux/time.h> 16 #include <linux/bug.h> 17 #include <linux/bvec.h> 18 #include <linux/cache.h> 19 #include <linux/rbtree.h> 20 #include <linux/socket.h> 21 #include <linux/refcount.h> 22 23 #include <linux/atomic.h> 24 #include <asm/types.h> 25 #include <linux/spinlock.h> 26 #include <net/checksum.h> 27 #include <linux/rcupdate.h> 28 #include <linux/dma-mapping.h> 29 #include <linux/netdev_features.h> 30 #include <net/flow_dissector.h> 31 #include <linux/in6.h> 32 #include <linux/if_packet.h> 33 #include <linux/llist.h> 34 #include <net/flow.h> 35 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 36 #include <linux/netfilter/nf_conntrack_common.h> 37 #endif 38 #include <net/net_debug.h> 39 #include <net/dropreason-core.h> 40 #include <net/netmem.h> 41 42 /** 43 * DOC: skb checksums 44 * 45 * The interface for checksum offload between the stack and networking drivers 46 * is as follows... 47 * 48 * IP checksum related features 49 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 50 * 51 * Drivers advertise checksum offload capabilities in the features of a device. 52 * From the stack's point of view these are capabilities offered by the driver. 53 * A driver typically only advertises features that it is capable of offloading 54 * to its device. 55 * 56 * .. flat-table:: Checksum related device features 57 * :widths: 1 10 58 * 59 * * - %NETIF_F_HW_CSUM 60 * - The driver (or its device) is able to compute one 61 * IP (one's complement) checksum for any combination 62 * of protocols or protocol layering. The checksum is 63 * computed and set in a packet per the CHECKSUM_PARTIAL 64 * interface (see below). 65 * 66 * * - %NETIF_F_IP_CSUM 67 * - Driver (device) is only able to checksum plain 68 * TCP or UDP packets over IPv4. These are specifically 69 * unencapsulated packets of the form IPv4|TCP or 70 * IPv4|UDP where the Protocol field in the IPv4 header 71 * is TCP or UDP. The IPv4 header may contain IP options. 72 * This feature cannot be set in features for a device 73 * with NETIF_F_HW_CSUM also set. This feature is being 74 * DEPRECATED (see below). 75 * 76 * * - %NETIF_F_IPV6_CSUM 77 * - Driver (device) is only able to checksum plain 78 * TCP or UDP packets over IPv6. These are specifically 79 * unencapsulated packets of the form IPv6|TCP or 80 * IPv6|UDP where the Next Header field in the IPv6 81 * header is either TCP or UDP. IPv6 extension headers 82 * are not supported with this feature. This feature 83 * cannot be set in features for a device with 84 * NETIF_F_HW_CSUM also set. This feature is being 85 * DEPRECATED (see below). 86 * 87 * * - %NETIF_F_RXCSUM 88 * - Driver (device) performs receive checksum offload. 89 * This flag is only used to disable the RX checksum 90 * feature for a device. The stack will accept receive 91 * checksum indication in packets received on a device 92 * regardless of whether NETIF_F_RXCSUM is set. 93 * 94 * Checksumming of received packets by device 95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 * 97 * Indication of checksum verification is set in &sk_buff.ip_summed. 98 * Possible values are: 99 * 100 * - %CHECKSUM_NONE 101 * 102 * Device did not checksum this packet e.g. due to lack of capabilities. 103 * The packet contains full (though not verified) checksum in packet but 104 * not in skb->csum. Thus, skb->csum is undefined in this case. 105 * 106 * - %CHECKSUM_UNNECESSARY 107 * 108 * The hardware you're dealing with doesn't calculate the full checksum 109 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums 110 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY 111 * if their checksums are okay. &sk_buff.csum is still undefined in this case 112 * though. A driver or device must never modify the checksum field in the 113 * packet even if checksum is verified. 114 * 115 * %CHECKSUM_UNNECESSARY is applicable to following protocols: 116 * 117 * - TCP: IPv6 and IPv4. 118 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a 119 * zero UDP checksum for either IPv4 or IPv6, the networking stack 120 * may perform further validation in this case. 121 * - GRE: only if the checksum is present in the header. 122 * - SCTP: indicates the CRC in SCTP header has been validated. 123 * - FCOE: indicates the CRC in FC frame has been validated. 124 * 125 * &sk_buff.csum_level indicates the number of consecutive checksums found in 126 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY. 127 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet 128 * and a device is able to verify the checksums for UDP (possibly zero), 129 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to 130 * two. If the device were only able to verify the UDP checksum and not 131 * GRE, either because it doesn't support GRE checksum or because GRE 132 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is 133 * not considered in this case). 134 * 135 * - %CHECKSUM_COMPLETE 136 * 137 * This is the most generic way. The device supplied checksum of the _whole_ 138 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the 139 * hardware doesn't need to parse L3/L4 headers to implement this. 140 * 141 * Notes: 142 * 143 * - Even if device supports only some protocols, but is able to produce 144 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 145 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols. 146 * 147 * - %CHECKSUM_PARTIAL 148 * 149 * A checksum is set up to be offloaded to a device as described in the 150 * output description for CHECKSUM_PARTIAL. This may occur on a packet 151 * received directly from another Linux OS, e.g., a virtualized Linux kernel 152 * on the same host, or it may be set in the input path in GRO or remote 153 * checksum offload. For the purposes of checksum verification, the checksum 154 * referred to by skb->csum_start + skb->csum_offset and any preceding 155 * checksums in the packet are considered verified. Any checksums in the 156 * packet that are after the checksum being offloaded are not considered to 157 * be verified. 158 * 159 * Checksumming on transmit for non-GSO 160 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 161 * 162 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet. 163 * Values are: 164 * 165 * - %CHECKSUM_PARTIAL 166 * 167 * The driver is required to checksum the packet as seen by hard_start_xmit() 168 * from &sk_buff.csum_start up to the end, and to record/write the checksum at 169 * offset &sk_buff.csum_start + &sk_buff.csum_offset. 170 * A driver may verify that the 171 * csum_start and csum_offset values are valid values given the length and 172 * offset of the packet, but it should not attempt to validate that the 173 * checksum refers to a legitimate transport layer checksum -- it is the 174 * purview of the stack to validate that csum_start and csum_offset are set 175 * correctly. 176 * 177 * When the stack requests checksum offload for a packet, the driver MUST 178 * ensure that the checksum is set correctly. A driver can either offload the 179 * checksum calculation to the device, or call skb_checksum_help (in the case 180 * that the device does not support offload for a particular checksum). 181 * 182 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of 183 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate 184 * checksum offload capability. 185 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based 186 * on network device checksumming capabilities: if a packet does not match 187 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of 188 * &sk_buff.csum_not_inet, see :ref:`crc`) 189 * is called to resolve the checksum. 190 * 191 * - %CHECKSUM_NONE 192 * 193 * The skb was already checksummed by the protocol, or a checksum is not 194 * required. 195 * 196 * - %CHECKSUM_UNNECESSARY 197 * 198 * This has the same meaning as CHECKSUM_NONE for checksum offload on 199 * output. 200 * 201 * - %CHECKSUM_COMPLETE 202 * 203 * Not used in checksum output. If a driver observes a packet with this value 204 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set. 205 * 206 * .. _crc: 207 * 208 * Non-IP checksum (CRC) offloads 209 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 210 * 211 * .. flat-table:: 212 * :widths: 1 10 213 * 214 * * - %NETIF_F_SCTP_CRC 215 * - This feature indicates that a device is capable of 216 * offloading the SCTP CRC in a packet. To perform this offload the stack 217 * will set csum_start and csum_offset accordingly, set ip_summed to 218 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication 219 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c. 220 * A driver that supports both IP checksum offload and SCTP CRC32c offload 221 * must verify which offload is configured for a packet by testing the 222 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to 223 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1. 224 * 225 * * - %NETIF_F_FCOE_CRC 226 * - This feature indicates that a device is capable of offloading the FCOE 227 * CRC in a packet. To perform this offload the stack will set ip_summed 228 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset 229 * accordingly. Note that there is no indication in the skbuff that the 230 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports 231 * both IP checksum offload and FCOE CRC offload must verify which offload 232 * is configured for a packet, presumably by inspecting packet headers. 233 * 234 * Checksumming on output with GSO 235 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 236 * 237 * In the case of a GSO packet (skb_is_gso() is true), checksum offload 238 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the 239 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as 240 * part of the GSO operation is implied. If a checksum is being offloaded 241 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and 242 * csum_offset are set to refer to the outermost checksum being offloaded 243 * (two offloaded checksums are possible with UDP encapsulation). 244 */ 245 246 /* Don't change this without changing skb_csum_unnecessary! */ 247 #define CHECKSUM_NONE 0 248 #define CHECKSUM_UNNECESSARY 1 249 #define CHECKSUM_COMPLETE 2 250 #define CHECKSUM_PARTIAL 3 251 252 /* Maximum value in skb->csum_level */ 253 #define SKB_MAX_CSUM_LEVEL 3 254 255 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) 256 #define SKB_WITH_OVERHEAD(X) \ 257 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 258 259 /* For X bytes available in skb->head, what is the minimal 260 * allocation needed, knowing struct skb_shared_info needs 261 * to be aligned. 262 */ 263 #define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \ 264 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 265 266 #define SKB_MAX_ORDER(X, ORDER) \ 267 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 268 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 269 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 270 271 /* return minimum truesize of one skb containing X bytes of data */ 272 #define SKB_TRUESIZE(X) ((X) + \ 273 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 274 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 275 276 struct ahash_request; 277 struct net_device; 278 struct scatterlist; 279 struct pipe_inode_info; 280 struct iov_iter; 281 struct napi_struct; 282 struct bpf_prog; 283 union bpf_attr; 284 struct skb_ext; 285 struct ts_config; 286 287 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 288 struct nf_bridge_info { 289 enum { 290 BRNF_PROTO_UNCHANGED, 291 BRNF_PROTO_8021Q, 292 BRNF_PROTO_PPPOE 293 } orig_proto:8; 294 u8 pkt_otherhost:1; 295 u8 in_prerouting:1; 296 u8 bridged_dnat:1; 297 u8 sabotage_in_done:1; 298 __u16 frag_max_size; 299 int physinif; 300 301 /* always valid & non-NULL from FORWARD on, for physdev match */ 302 struct net_device *physoutdev; 303 union { 304 /* prerouting: detect dnat in orig/reply direction */ 305 __be32 ipv4_daddr; 306 struct in6_addr ipv6_daddr; 307 308 /* after prerouting + nat detected: store original source 309 * mac since neigh resolution overwrites it, only used while 310 * skb is out in neigh layer. 311 */ 312 char neigh_header[8]; 313 }; 314 }; 315 #endif 316 317 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 318 /* Chain in tc_skb_ext will be used to share the tc chain with 319 * ovs recirc_id. It will be set to the current chain by tc 320 * and read by ovs to recirc_id. 321 */ 322 struct tc_skb_ext { 323 union { 324 u64 act_miss_cookie; 325 __u32 chain; 326 }; 327 __u16 mru; 328 __u16 zone; 329 u8 post_ct:1; 330 u8 post_ct_snat:1; 331 u8 post_ct_dnat:1; 332 u8 act_miss:1; /* Set if act_miss_cookie is used */ 333 u8 l2_miss:1; /* Set by bridge upon FDB or MDB miss */ 334 }; 335 #endif 336 337 struct sk_buff_head { 338 /* These two members must be first to match sk_buff. */ 339 struct_group_tagged(sk_buff_list, list, 340 struct sk_buff *next; 341 struct sk_buff *prev; 342 ); 343 344 __u32 qlen; 345 spinlock_t lock; 346 }; 347 348 struct sk_buff; 349 350 #ifndef CONFIG_MAX_SKB_FRAGS 351 # define CONFIG_MAX_SKB_FRAGS 17 352 #endif 353 354 #define MAX_SKB_FRAGS CONFIG_MAX_SKB_FRAGS 355 356 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to 357 * segment using its current segmentation instead. 358 */ 359 #define GSO_BY_FRAGS 0xFFFF 360 361 typedef struct skb_frag { 362 netmem_ref netmem; 363 unsigned int len; 364 unsigned int offset; 365 } skb_frag_t; 366 367 /** 368 * skb_frag_size() - Returns the size of a skb fragment 369 * @frag: skb fragment 370 */ 371 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 372 { 373 return frag->len; 374 } 375 376 /** 377 * skb_frag_size_set() - Sets the size of a skb fragment 378 * @frag: skb fragment 379 * @size: size of fragment 380 */ 381 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 382 { 383 frag->len = size; 384 } 385 386 /** 387 * skb_frag_size_add() - Increments the size of a skb fragment by @delta 388 * @frag: skb fragment 389 * @delta: value to add 390 */ 391 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 392 { 393 frag->len += delta; 394 } 395 396 /** 397 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta 398 * @frag: skb fragment 399 * @delta: value to subtract 400 */ 401 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 402 { 403 frag->len -= delta; 404 } 405 406 /** 407 * skb_frag_must_loop - Test if %p is a high memory page 408 * @p: fragment's page 409 */ 410 static inline bool skb_frag_must_loop(struct page *p) 411 { 412 #if defined(CONFIG_HIGHMEM) 413 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p)) 414 return true; 415 #endif 416 return false; 417 } 418 419 /** 420 * skb_frag_foreach_page - loop over pages in a fragment 421 * 422 * @f: skb frag to operate on 423 * @f_off: offset from start of f->netmem 424 * @f_len: length from f_off to loop over 425 * @p: (temp var) current page 426 * @p_off: (temp var) offset from start of current page, 427 * non-zero only on first page. 428 * @p_len: (temp var) length in current page, 429 * < PAGE_SIZE only on first and last page. 430 * @copied: (temp var) length so far, excluding current p_len. 431 * 432 * A fragment can hold a compound page, in which case per-page 433 * operations, notably kmap_atomic, must be called for each 434 * regular page. 435 */ 436 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \ 437 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \ 438 p_off = (f_off) & (PAGE_SIZE - 1), \ 439 p_len = skb_frag_must_loop(p) ? \ 440 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \ 441 copied = 0; \ 442 copied < f_len; \ 443 copied += p_len, p++, p_off = 0, \ 444 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \ 445 446 /** 447 * struct skb_shared_hwtstamps - hardware time stamps 448 * @hwtstamp: hardware time stamp transformed into duration 449 * since arbitrary point in time 450 * @netdev_data: address/cookie of network device driver used as 451 * reference to actual hardware time stamp 452 * 453 * Software time stamps generated by ktime_get_real() are stored in 454 * skb->tstamp. 455 * 456 * hwtstamps can only be compared against other hwtstamps from 457 * the same device. 458 * 459 * This structure is attached to packets as part of the 460 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 461 */ 462 struct skb_shared_hwtstamps { 463 union { 464 ktime_t hwtstamp; 465 void *netdev_data; 466 }; 467 }; 468 469 /* Definitions for tx_flags in struct skb_shared_info */ 470 enum { 471 /* generate hardware time stamp */ 472 SKBTX_HW_TSTAMP = 1 << 0, 473 474 /* generate software time stamp when queueing packet to NIC */ 475 SKBTX_SW_TSTAMP = 1 << 1, 476 477 /* device driver is going to provide hardware time stamp */ 478 SKBTX_IN_PROGRESS = 1 << 2, 479 480 /* generate hardware time stamp based on cycles if supported */ 481 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, 482 483 /* generate wifi status information (where possible) */ 484 SKBTX_WIFI_STATUS = 1 << 4, 485 486 /* determine hardware time stamp based on time or cycles */ 487 SKBTX_HW_TSTAMP_NETDEV = 1 << 5, 488 489 /* generate software time stamp when entering packet scheduling */ 490 SKBTX_SCHED_TSTAMP = 1 << 6, 491 }; 492 493 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ 494 SKBTX_SCHED_TSTAMP) 495 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ 496 SKBTX_HW_TSTAMP_USE_CYCLES | \ 497 SKBTX_ANY_SW_TSTAMP) 498 499 /* Definitions for flags in struct skb_shared_info */ 500 enum { 501 /* use zcopy routines */ 502 SKBFL_ZEROCOPY_ENABLE = BIT(0), 503 504 /* This indicates at least one fragment might be overwritten 505 * (as in vmsplice(), sendfile() ...) 506 * If we need to compute a TX checksum, we'll need to copy 507 * all frags to avoid possible bad checksum 508 */ 509 SKBFL_SHARED_FRAG = BIT(1), 510 511 /* segment contains only zerocopy data and should not be 512 * charged to the kernel memory. 513 */ 514 SKBFL_PURE_ZEROCOPY = BIT(2), 515 516 SKBFL_DONT_ORPHAN = BIT(3), 517 518 /* page references are managed by the ubuf_info, so it's safe to 519 * use frags only up until ubuf_info is released 520 */ 521 SKBFL_MANAGED_FRAG_REFS = BIT(4), 522 }; 523 524 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG) 525 #define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \ 526 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS) 527 528 struct ubuf_info_ops { 529 void (*complete)(struct sk_buff *, struct ubuf_info *, 530 bool zerocopy_success); 531 /* has to be compatible with skb_zcopy_set() */ 532 int (*link_skb)(struct sk_buff *skb, struct ubuf_info *uarg); 533 }; 534 535 /* 536 * The callback notifies userspace to release buffers when skb DMA is done in 537 * lower device, the skb last reference should be 0 when calling this. 538 * The zerocopy_success argument is true if zero copy transmit occurred, 539 * false on data copy or out of memory error caused by data copy attempt. 540 * The ctx field is used to track device context. 541 * The desc field is used to track userspace buffer index. 542 */ 543 struct ubuf_info { 544 const struct ubuf_info_ops *ops; 545 refcount_t refcnt; 546 u8 flags; 547 }; 548 549 struct ubuf_info_msgzc { 550 struct ubuf_info ubuf; 551 552 union { 553 struct { 554 unsigned long desc; 555 void *ctx; 556 }; 557 struct { 558 u32 id; 559 u16 len; 560 u16 zerocopy:1; 561 u32 bytelen; 562 }; 563 }; 564 565 struct mmpin { 566 struct user_struct *user; 567 unsigned int num_pg; 568 } mmp; 569 }; 570 571 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg)) 572 #define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \ 573 ubuf) 574 575 int mm_account_pinned_pages(struct mmpin *mmp, size_t size); 576 void mm_unaccount_pinned_pages(struct mmpin *mmp); 577 578 /* Preserve some data across TX submission and completion. 579 * 580 * Note, this state is stored in the driver. Extending the layout 581 * might need some special care. 582 */ 583 struct xsk_tx_metadata_compl { 584 __u64 *tx_timestamp; 585 }; 586 587 /* This data is invariant across clones and lives at 588 * the end of the header data, ie. at skb->end. 589 */ 590 struct skb_shared_info { 591 __u8 flags; 592 __u8 meta_len; 593 __u8 nr_frags; 594 __u8 tx_flags; 595 unsigned short gso_size; 596 /* Warning: this field is not always filled in (UFO)! */ 597 unsigned short gso_segs; 598 struct sk_buff *frag_list; 599 union { 600 struct skb_shared_hwtstamps hwtstamps; 601 struct xsk_tx_metadata_compl xsk_meta; 602 }; 603 unsigned int gso_type; 604 u32 tskey; 605 606 /* 607 * Warning : all fields before dataref are cleared in __alloc_skb() 608 */ 609 atomic_t dataref; 610 unsigned int xdp_frags_size; 611 612 /* Intermediate layers must ensure that destructor_arg 613 * remains valid until skb destructor */ 614 void * destructor_arg; 615 616 /* must be last field, see pskb_expand_head() */ 617 skb_frag_t frags[MAX_SKB_FRAGS]; 618 }; 619 620 /** 621 * DOC: dataref and headerless skbs 622 * 623 * Transport layers send out clones of payload skbs they hold for 624 * retransmissions. To allow lower layers of the stack to prepend their headers 625 * we split &skb_shared_info.dataref into two halves. 626 * The lower 16 bits count the overall number of references. 627 * The higher 16 bits indicate how many of the references are payload-only. 628 * skb_header_cloned() checks if skb is allowed to add / write the headers. 629 * 630 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr 631 * (via __skb_header_release()). Any clone created from marked skb will get 632 * &sk_buff.hdr_len populated with the available headroom. 633 * If there's the only clone in existence it's able to modify the headroom 634 * at will. The sequence of calls inside the transport layer is:: 635 * 636 * <alloc skb> 637 * skb_reserve() 638 * __skb_header_release() 639 * skb_clone() 640 * // send the clone down the stack 641 * 642 * This is not a very generic construct and it depends on the transport layers 643 * doing the right thing. In practice there's usually only one payload-only skb. 644 * Having multiple payload-only skbs with different lengths of hdr_len is not 645 * possible. The payload-only skbs should never leave their owner. 646 */ 647 #define SKB_DATAREF_SHIFT 16 648 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 649 650 651 enum { 652 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ 653 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ 654 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ 655 }; 656 657 enum { 658 SKB_GSO_TCPV4 = 1 << 0, 659 660 /* This indicates the skb is from an untrusted source. */ 661 SKB_GSO_DODGY = 1 << 1, 662 663 /* This indicates the tcp segment has CWR set. */ 664 SKB_GSO_TCP_ECN = 1 << 2, 665 666 SKB_GSO_TCP_FIXEDID = 1 << 3, 667 668 SKB_GSO_TCPV6 = 1 << 4, 669 670 SKB_GSO_FCOE = 1 << 5, 671 672 SKB_GSO_GRE = 1 << 6, 673 674 SKB_GSO_GRE_CSUM = 1 << 7, 675 676 SKB_GSO_IPXIP4 = 1 << 8, 677 678 SKB_GSO_IPXIP6 = 1 << 9, 679 680 SKB_GSO_UDP_TUNNEL = 1 << 10, 681 682 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, 683 684 SKB_GSO_PARTIAL = 1 << 12, 685 686 SKB_GSO_TUNNEL_REMCSUM = 1 << 13, 687 688 SKB_GSO_SCTP = 1 << 14, 689 690 SKB_GSO_ESP = 1 << 15, 691 692 SKB_GSO_UDP = 1 << 16, 693 694 SKB_GSO_UDP_L4 = 1 << 17, 695 696 SKB_GSO_FRAGLIST = 1 << 18, 697 }; 698 699 #if BITS_PER_LONG > 32 700 #define NET_SKBUFF_DATA_USES_OFFSET 1 701 #endif 702 703 #ifdef NET_SKBUFF_DATA_USES_OFFSET 704 typedef unsigned int sk_buff_data_t; 705 #else 706 typedef unsigned char *sk_buff_data_t; 707 #endif 708 709 enum skb_tstamp_type { 710 SKB_CLOCK_REALTIME, 711 SKB_CLOCK_MONOTONIC, 712 SKB_CLOCK_TAI, 713 __SKB_CLOCK_MAX = SKB_CLOCK_TAI, 714 }; 715 716 /** 717 * DOC: Basic sk_buff geometry 718 * 719 * struct sk_buff itself is a metadata structure and does not hold any packet 720 * data. All the data is held in associated buffers. 721 * 722 * &sk_buff.head points to the main "head" buffer. The head buffer is divided 723 * into two parts: 724 * 725 * - data buffer, containing headers and sometimes payload; 726 * this is the part of the skb operated on by the common helpers 727 * such as skb_put() or skb_pull(); 728 * - shared info (struct skb_shared_info) which holds an array of pointers 729 * to read-only data in the (page, offset, length) format. 730 * 731 * Optionally &skb_shared_info.frag_list may point to another skb. 732 * 733 * Basic diagram may look like this:: 734 * 735 * --------------- 736 * | sk_buff | 737 * --------------- 738 * ,--------------------------- + head 739 * / ,----------------- + data 740 * / / ,----------- + tail 741 * | | | , + end 742 * | | | | 743 * v v v v 744 * ----------------------------------------------- 745 * | headroom | data | tailroom | skb_shared_info | 746 * ----------------------------------------------- 747 * + [page frag] 748 * + [page frag] 749 * + [page frag] 750 * + [page frag] --------- 751 * + frag_list --> | sk_buff | 752 * --------- 753 * 754 */ 755 756 /** 757 * struct sk_buff - socket buffer 758 * @next: Next buffer in list 759 * @prev: Previous buffer in list 760 * @tstamp: Time we arrived/left 761 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point 762 * for retransmit timer 763 * @rbnode: RB tree node, alternative to next/prev for netem/tcp 764 * @list: queue head 765 * @ll_node: anchor in an llist (eg socket defer_list) 766 * @sk: Socket we are owned by 767 * @dev: Device we arrived on/are leaving by 768 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL 769 * @cb: Control buffer. Free for use by every layer. Put private vars here 770 * @_skb_refdst: destination entry (with norefcount bit) 771 * @len: Length of actual data 772 * @data_len: Data length 773 * @mac_len: Length of link layer header 774 * @hdr_len: writable header length of cloned skb 775 * @csum: Checksum (must include start/offset pair) 776 * @csum_start: Offset from skb->head where checksumming should start 777 * @csum_offset: Offset from csum_start where checksum should be stored 778 * @priority: Packet queueing priority 779 * @ignore_df: allow local fragmentation 780 * @cloned: Head may be cloned (check refcnt to be sure) 781 * @ip_summed: Driver fed us an IP checksum 782 * @nohdr: Payload reference only, must not modify header 783 * @pkt_type: Packet class 784 * @fclone: skbuff clone status 785 * @ipvs_property: skbuff is owned by ipvs 786 * @inner_protocol_type: whether the inner protocol is 787 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO 788 * @remcsum_offload: remote checksum offload is enabled 789 * @offload_fwd_mark: Packet was L2-forwarded in hardware 790 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware 791 * @tc_skip_classify: do not classify packet. set by IFB device 792 * @tc_at_ingress: used within tc_classify to distinguish in/egress 793 * @redirected: packet was redirected by packet classifier 794 * @from_ingress: packet was redirected from the ingress path 795 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h 796 * @peeked: this packet has been seen already, so stats have been 797 * done for it, don't do them again 798 * @nf_trace: netfilter packet trace flag 799 * @protocol: Packet protocol from driver 800 * @destructor: Destruct function 801 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue) 802 * @_sk_redir: socket redirection information for skmsg 803 * @_nfct: Associated connection, if any (with nfctinfo bits) 804 * @skb_iif: ifindex of device we arrived on 805 * @tc_index: Traffic control index 806 * @hash: the packet hash 807 * @queue_mapping: Queue mapping for multiqueue devices 808 * @head_frag: skb was allocated from page fragments, 809 * not allocated by kmalloc() or vmalloc(). 810 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves 811 * @pp_recycle: mark the packet for recycling instead of freeing (implies 812 * page_pool support on driver) 813 * @active_extensions: active extensions (skb_ext_id types) 814 * @ndisc_nodetype: router type (from link layer) 815 * @ooo_okay: allow the mapping of a socket to a queue to be changed 816 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport 817 * ports. 818 * @sw_hash: indicates hash was computed in software stack 819 * @wifi_acked_valid: wifi_acked was set 820 * @wifi_acked: whether frame was acked on wifi or not 821 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 822 * @encapsulation: indicates the inner headers in the skbuff are valid 823 * @encap_hdr_csum: software checksum is needed 824 * @csum_valid: checksum is already valid 825 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL 826 * @csum_complete_sw: checksum was completed by software 827 * @csum_level: indicates the number of consecutive checksums found in 828 * the packet minus one that have been verified as 829 * CHECKSUM_UNNECESSARY (max 3) 830 * @unreadable: indicates that at least 1 of the fragments in this skb is 831 * unreadable. 832 * @dst_pending_confirm: need to confirm neighbour 833 * @decrypted: Decrypted SKB 834 * @slow_gro: state present at GRO time, slower prepare step required 835 * @tstamp_type: When set, skb->tstamp has the 836 * delivery_time clock base of skb->tstamp. 837 * @napi_id: id of the NAPI struct this skb came from 838 * @sender_cpu: (aka @napi_id) source CPU in XPS 839 * @alloc_cpu: CPU which did the skb allocation. 840 * @secmark: security marking 841 * @mark: Generic packet mark 842 * @reserved_tailroom: (aka @mark) number of bytes of free space available 843 * at the tail of an sk_buff 844 * @vlan_all: vlan fields (proto & tci) 845 * @vlan_proto: vlan encapsulation protocol 846 * @vlan_tci: vlan tag control information 847 * @inner_protocol: Protocol (encapsulation) 848 * @inner_ipproto: (aka @inner_protocol) stores ipproto when 849 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO; 850 * @inner_transport_header: Inner transport layer header (encapsulation) 851 * @inner_network_header: Network layer header (encapsulation) 852 * @inner_mac_header: Link layer header (encapsulation) 853 * @transport_header: Transport layer header 854 * @network_header: Network layer header 855 * @mac_header: Link layer header 856 * @kcov_handle: KCOV remote handle for remote coverage collection 857 * @tail: Tail pointer 858 * @end: End pointer 859 * @head: Head of buffer 860 * @data: Data head pointer 861 * @truesize: Buffer size 862 * @users: User count - see {datagram,tcp}.c 863 * @extensions: allocated extensions, valid if active_extensions is nonzero 864 */ 865 866 struct sk_buff { 867 union { 868 struct { 869 /* These two members must be first to match sk_buff_head. */ 870 struct sk_buff *next; 871 struct sk_buff *prev; 872 873 union { 874 struct net_device *dev; 875 /* Some protocols might use this space to store information, 876 * while device pointer would be NULL. 877 * UDP receive path is one user. 878 */ 879 unsigned long dev_scratch; 880 }; 881 }; 882 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */ 883 struct list_head list; 884 struct llist_node ll_node; 885 }; 886 887 struct sock *sk; 888 889 union { 890 ktime_t tstamp; 891 u64 skb_mstamp_ns; /* earliest departure time */ 892 }; 893 /* 894 * This is the control buffer. It is free to use for every 895 * layer. Please put your private variables there. If you 896 * want to keep them across layers you have to do a skb_clone() 897 * first. This is owned by whoever has the skb queued ATM. 898 */ 899 char cb[48] __aligned(8); 900 901 union { 902 struct { 903 unsigned long _skb_refdst; 904 void (*destructor)(struct sk_buff *skb); 905 }; 906 struct list_head tcp_tsorted_anchor; 907 #ifdef CONFIG_NET_SOCK_MSG 908 unsigned long _sk_redir; 909 #endif 910 }; 911 912 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 913 unsigned long _nfct; 914 #endif 915 unsigned int len, 916 data_len; 917 __u16 mac_len, 918 hdr_len; 919 920 /* Following fields are _not_ copied in __copy_skb_header() 921 * Note that queue_mapping is here mostly to fill a hole. 922 */ 923 __u16 queue_mapping; 924 925 /* if you move cloned around you also must adapt those constants */ 926 #ifdef __BIG_ENDIAN_BITFIELD 927 #define CLONED_MASK (1 << 7) 928 #else 929 #define CLONED_MASK 1 930 #endif 931 #define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset) 932 933 /* private: */ 934 __u8 __cloned_offset[0]; 935 /* public: */ 936 __u8 cloned:1, 937 nohdr:1, 938 fclone:2, 939 peeked:1, 940 head_frag:1, 941 pfmemalloc:1, 942 pp_recycle:1; /* page_pool recycle indicator */ 943 #ifdef CONFIG_SKB_EXTENSIONS 944 __u8 active_extensions; 945 #endif 946 947 /* Fields enclosed in headers group are copied 948 * using a single memcpy() in __copy_skb_header() 949 */ 950 struct_group(headers, 951 952 /* private: */ 953 __u8 __pkt_type_offset[0]; 954 /* public: */ 955 __u8 pkt_type:3; /* see PKT_TYPE_MAX */ 956 __u8 ignore_df:1; 957 __u8 dst_pending_confirm:1; 958 __u8 ip_summed:2; 959 __u8 ooo_okay:1; 960 961 /* private: */ 962 __u8 __mono_tc_offset[0]; 963 /* public: */ 964 __u8 tstamp_type:2; /* See skb_tstamp_type */ 965 #ifdef CONFIG_NET_XGRESS 966 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */ 967 __u8 tc_skip_classify:1; 968 #endif 969 __u8 remcsum_offload:1; 970 __u8 csum_complete_sw:1; 971 __u8 csum_level:2; 972 __u8 inner_protocol_type:1; 973 974 __u8 l4_hash:1; 975 __u8 sw_hash:1; 976 #ifdef CONFIG_WIRELESS 977 __u8 wifi_acked_valid:1; 978 __u8 wifi_acked:1; 979 #endif 980 __u8 no_fcs:1; 981 /* Indicates the inner headers are valid in the skbuff. */ 982 __u8 encapsulation:1; 983 __u8 encap_hdr_csum:1; 984 __u8 csum_valid:1; 985 #ifdef CONFIG_IPV6_NDISC_NODETYPE 986 __u8 ndisc_nodetype:2; 987 #endif 988 989 #if IS_ENABLED(CONFIG_IP_VS) 990 __u8 ipvs_property:1; 991 #endif 992 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 993 __u8 nf_trace:1; 994 #endif 995 #ifdef CONFIG_NET_SWITCHDEV 996 __u8 offload_fwd_mark:1; 997 __u8 offload_l3_fwd_mark:1; 998 #endif 999 __u8 redirected:1; 1000 #ifdef CONFIG_NET_REDIRECT 1001 __u8 from_ingress:1; 1002 #endif 1003 #ifdef CONFIG_NETFILTER_SKIP_EGRESS 1004 __u8 nf_skip_egress:1; 1005 #endif 1006 #ifdef CONFIG_SKB_DECRYPTED 1007 __u8 decrypted:1; 1008 #endif 1009 __u8 slow_gro:1; 1010 #if IS_ENABLED(CONFIG_IP_SCTP) 1011 __u8 csum_not_inet:1; 1012 #endif 1013 __u8 unreadable:1; 1014 #if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS) 1015 __u16 tc_index; /* traffic control index */ 1016 #endif 1017 1018 u16 alloc_cpu; 1019 1020 union { 1021 __wsum csum; 1022 struct { 1023 __u16 csum_start; 1024 __u16 csum_offset; 1025 }; 1026 }; 1027 __u32 priority; 1028 int skb_iif; 1029 __u32 hash; 1030 union { 1031 u32 vlan_all; 1032 struct { 1033 __be16 vlan_proto; 1034 __u16 vlan_tci; 1035 }; 1036 }; 1037 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS) 1038 union { 1039 unsigned int napi_id; 1040 unsigned int sender_cpu; 1041 }; 1042 #endif 1043 #ifdef CONFIG_NETWORK_SECMARK 1044 __u32 secmark; 1045 #endif 1046 1047 union { 1048 __u32 mark; 1049 __u32 reserved_tailroom; 1050 }; 1051 1052 union { 1053 __be16 inner_protocol; 1054 __u8 inner_ipproto; 1055 }; 1056 1057 __u16 inner_transport_header; 1058 __u16 inner_network_header; 1059 __u16 inner_mac_header; 1060 1061 __be16 protocol; 1062 __u16 transport_header; 1063 __u16 network_header; 1064 __u16 mac_header; 1065 1066 #ifdef CONFIG_KCOV 1067 u64 kcov_handle; 1068 #endif 1069 1070 ); /* end headers group */ 1071 1072 /* These elements must be at the end, see alloc_skb() for details. */ 1073 sk_buff_data_t tail; 1074 sk_buff_data_t end; 1075 unsigned char *head, 1076 *data; 1077 unsigned int truesize; 1078 refcount_t users; 1079 1080 #ifdef CONFIG_SKB_EXTENSIONS 1081 /* only usable after checking ->active_extensions != 0 */ 1082 struct skb_ext *extensions; 1083 #endif 1084 }; 1085 1086 /* if you move pkt_type around you also must adapt those constants */ 1087 #ifdef __BIG_ENDIAN_BITFIELD 1088 #define PKT_TYPE_MAX (7 << 5) 1089 #else 1090 #define PKT_TYPE_MAX 7 1091 #endif 1092 #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset) 1093 1094 /* if you move tc_at_ingress or tstamp_type 1095 * around, you also must adapt these constants. 1096 */ 1097 #ifdef __BIG_ENDIAN_BITFIELD 1098 #define SKB_TSTAMP_TYPE_MASK (3 << 6) 1099 #define SKB_TSTAMP_TYPE_RSHIFT (6) 1100 #define TC_AT_INGRESS_MASK (1 << 5) 1101 #else 1102 #define SKB_TSTAMP_TYPE_MASK (3) 1103 #define TC_AT_INGRESS_MASK (1 << 2) 1104 #endif 1105 #define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset) 1106 1107 #ifdef __KERNEL__ 1108 /* 1109 * Handling routines are only of interest to the kernel 1110 */ 1111 1112 #define SKB_ALLOC_FCLONE 0x01 1113 #define SKB_ALLOC_RX 0x02 1114 #define SKB_ALLOC_NAPI 0x04 1115 1116 /** 1117 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves 1118 * @skb: buffer 1119 */ 1120 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 1121 { 1122 return unlikely(skb->pfmemalloc); 1123 } 1124 1125 /* 1126 * skb might have a dst pointer attached, refcounted or not. 1127 * _skb_refdst low order bit is set if refcount was _not_ taken 1128 */ 1129 #define SKB_DST_NOREF 1UL 1130 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 1131 1132 /** 1133 * skb_dst - returns skb dst_entry 1134 * @skb: buffer 1135 * 1136 * Returns skb dst_entry, regardless of reference taken or not. 1137 */ 1138 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 1139 { 1140 /* If refdst was not refcounted, check we still are in a 1141 * rcu_read_lock section 1142 */ 1143 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 1144 !rcu_read_lock_held() && 1145 !rcu_read_lock_bh_held()); 1146 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 1147 } 1148 1149 /** 1150 * skb_dst_set - sets skb dst 1151 * @skb: buffer 1152 * @dst: dst entry 1153 * 1154 * Sets skb dst, assuming a reference was taken on dst and should 1155 * be released by skb_dst_drop() 1156 */ 1157 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 1158 { 1159 skb->slow_gro |= !!dst; 1160 skb->_skb_refdst = (unsigned long)dst; 1161 } 1162 1163 /** 1164 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 1165 * @skb: buffer 1166 * @dst: dst entry 1167 * 1168 * Sets skb dst, assuming a reference was not taken on dst. 1169 * If dst entry is cached, we do not take reference and dst_release 1170 * will be avoided by refdst_drop. If dst entry is not cached, we take 1171 * reference, so that last dst_release can destroy the dst immediately. 1172 */ 1173 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 1174 { 1175 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 1176 skb->slow_gro |= !!dst; 1177 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 1178 } 1179 1180 /** 1181 * skb_dst_is_noref - Test if skb dst isn't refcounted 1182 * @skb: buffer 1183 */ 1184 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 1185 { 1186 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 1187 } 1188 1189 /* For mangling skb->pkt_type from user space side from applications 1190 * such as nft, tc, etc, we only allow a conservative subset of 1191 * possible pkt_types to be set. 1192 */ 1193 static inline bool skb_pkt_type_ok(u32 ptype) 1194 { 1195 return ptype <= PACKET_OTHERHOST; 1196 } 1197 1198 /** 1199 * skb_napi_id - Returns the skb's NAPI id 1200 * @skb: buffer 1201 */ 1202 static inline unsigned int skb_napi_id(const struct sk_buff *skb) 1203 { 1204 #ifdef CONFIG_NET_RX_BUSY_POLL 1205 return skb->napi_id; 1206 #else 1207 return 0; 1208 #endif 1209 } 1210 1211 static inline bool skb_wifi_acked_valid(const struct sk_buff *skb) 1212 { 1213 #ifdef CONFIG_WIRELESS 1214 return skb->wifi_acked_valid; 1215 #else 1216 return 0; 1217 #endif 1218 } 1219 1220 /** 1221 * skb_unref - decrement the skb's reference count 1222 * @skb: buffer 1223 * 1224 * Returns true if we can free the skb. 1225 */ 1226 static inline bool skb_unref(struct sk_buff *skb) 1227 { 1228 if (unlikely(!skb)) 1229 return false; 1230 if (!IS_ENABLED(CONFIG_DEBUG_NET) && likely(refcount_read(&skb->users) == 1)) 1231 smp_rmb(); 1232 else if (likely(!refcount_dec_and_test(&skb->users))) 1233 return false; 1234 1235 return true; 1236 } 1237 1238 static inline bool skb_data_unref(const struct sk_buff *skb, 1239 struct skb_shared_info *shinfo) 1240 { 1241 int bias; 1242 1243 if (!skb->cloned) 1244 return true; 1245 1246 bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1; 1247 1248 if (atomic_read(&shinfo->dataref) == bias) 1249 smp_rmb(); 1250 else if (atomic_sub_return(bias, &shinfo->dataref)) 1251 return false; 1252 1253 return true; 1254 } 1255 1256 void __fix_address sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb, 1257 enum skb_drop_reason reason); 1258 1259 static inline void 1260 kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) 1261 { 1262 sk_skb_reason_drop(NULL, skb, reason); 1263 } 1264 1265 /** 1266 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason 1267 * @skb: buffer to free 1268 */ 1269 static inline void kfree_skb(struct sk_buff *skb) 1270 { 1271 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED); 1272 } 1273 1274 void skb_release_head_state(struct sk_buff *skb); 1275 void kfree_skb_list_reason(struct sk_buff *segs, 1276 enum skb_drop_reason reason); 1277 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt); 1278 void skb_tx_error(struct sk_buff *skb); 1279 1280 static inline void kfree_skb_list(struct sk_buff *segs) 1281 { 1282 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED); 1283 } 1284 1285 #ifdef CONFIG_TRACEPOINTS 1286 void consume_skb(struct sk_buff *skb); 1287 #else 1288 static inline void consume_skb(struct sk_buff *skb) 1289 { 1290 return kfree_skb(skb); 1291 } 1292 #endif 1293 1294 void __consume_stateless_skb(struct sk_buff *skb); 1295 void __kfree_skb(struct sk_buff *skb); 1296 1297 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 1298 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 1299 bool *fragstolen, int *delta_truesize); 1300 1301 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 1302 int node); 1303 struct sk_buff *__build_skb(void *data, unsigned int frag_size); 1304 struct sk_buff *build_skb(void *data, unsigned int frag_size); 1305 struct sk_buff *build_skb_around(struct sk_buff *skb, 1306 void *data, unsigned int frag_size); 1307 void skb_attempt_defer_free(struct sk_buff *skb); 1308 1309 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size); 1310 struct sk_buff *slab_build_skb(void *data); 1311 1312 /** 1313 * alloc_skb - allocate a network buffer 1314 * @size: size to allocate 1315 * @priority: allocation mask 1316 * 1317 * This function is a convenient wrapper around __alloc_skb(). 1318 */ 1319 static inline struct sk_buff *alloc_skb(unsigned int size, 1320 gfp_t priority) 1321 { 1322 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 1323 } 1324 1325 struct sk_buff *alloc_skb_with_frags(unsigned long header_len, 1326 unsigned long data_len, 1327 int max_page_order, 1328 int *errcode, 1329 gfp_t gfp_mask); 1330 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first); 1331 1332 /* Layout of fast clones : [skb1][skb2][fclone_ref] */ 1333 struct sk_buff_fclones { 1334 struct sk_buff skb1; 1335 1336 struct sk_buff skb2; 1337 1338 refcount_t fclone_ref; 1339 }; 1340 1341 /** 1342 * skb_fclone_busy - check if fclone is busy 1343 * @sk: socket 1344 * @skb: buffer 1345 * 1346 * Returns true if skb is a fast clone, and its clone is not freed. 1347 * Some drivers call skb_orphan() in their ndo_start_xmit(), 1348 * so we also check that didn't happen. 1349 */ 1350 static inline bool skb_fclone_busy(const struct sock *sk, 1351 const struct sk_buff *skb) 1352 { 1353 const struct sk_buff_fclones *fclones; 1354 1355 fclones = container_of(skb, struct sk_buff_fclones, skb1); 1356 1357 return skb->fclone == SKB_FCLONE_ORIG && 1358 refcount_read(&fclones->fclone_ref) > 1 && 1359 READ_ONCE(fclones->skb2.sk) == sk; 1360 } 1361 1362 /** 1363 * alloc_skb_fclone - allocate a network buffer from fclone cache 1364 * @size: size to allocate 1365 * @priority: allocation mask 1366 * 1367 * This function is a convenient wrapper around __alloc_skb(). 1368 */ 1369 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 1370 gfp_t priority) 1371 { 1372 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 1373 } 1374 1375 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 1376 void skb_headers_offset_update(struct sk_buff *skb, int off); 1377 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 1378 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 1379 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old); 1380 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 1381 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, 1382 gfp_t gfp_mask, bool fclone); 1383 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, 1384 gfp_t gfp_mask) 1385 { 1386 return __pskb_copy_fclone(skb, headroom, gfp_mask, false); 1387 } 1388 1389 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 1390 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 1391 unsigned int headroom); 1392 struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom); 1393 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 1394 int newtailroom, gfp_t priority); 1395 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, 1396 int offset, int len); 1397 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, 1398 int offset, int len); 1399 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 1400 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error); 1401 1402 /** 1403 * skb_pad - zero pad the tail of an skb 1404 * @skb: buffer to pad 1405 * @pad: space to pad 1406 * 1407 * Ensure that a buffer is followed by a padding area that is zero 1408 * filled. Used by network drivers which may DMA or transfer data 1409 * beyond the buffer end onto the wire. 1410 * 1411 * May return error in out of memory cases. The skb is freed on error. 1412 */ 1413 static inline int skb_pad(struct sk_buff *skb, int pad) 1414 { 1415 return __skb_pad(skb, pad, true); 1416 } 1417 #define dev_kfree_skb(a) consume_skb(a) 1418 1419 int skb_append_pagefrags(struct sk_buff *skb, struct page *page, 1420 int offset, size_t size, size_t max_frags); 1421 1422 struct skb_seq_state { 1423 __u32 lower_offset; 1424 __u32 upper_offset; 1425 __u32 frag_idx; 1426 __u32 stepped_offset; 1427 struct sk_buff *root_skb; 1428 struct sk_buff *cur_skb; 1429 __u8 *frag_data; 1430 __u32 frag_off; 1431 }; 1432 1433 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 1434 unsigned int to, struct skb_seq_state *st); 1435 unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 1436 struct skb_seq_state *st); 1437 void skb_abort_seq_read(struct skb_seq_state *st); 1438 int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len); 1439 1440 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 1441 unsigned int to, struct ts_config *config); 1442 1443 /* 1444 * Packet hash types specify the type of hash in skb_set_hash. 1445 * 1446 * Hash types refer to the protocol layer addresses which are used to 1447 * construct a packet's hash. The hashes are used to differentiate or identify 1448 * flows of the protocol layer for the hash type. Hash types are either 1449 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 1450 * 1451 * Properties of hashes: 1452 * 1453 * 1) Two packets in different flows have different hash values 1454 * 2) Two packets in the same flow should have the same hash value 1455 * 1456 * A hash at a higher layer is considered to be more specific. A driver should 1457 * set the most specific hash possible. 1458 * 1459 * A driver cannot indicate a more specific hash than the layer at which a hash 1460 * was computed. For instance an L3 hash cannot be set as an L4 hash. 1461 * 1462 * A driver may indicate a hash level which is less specific than the 1463 * actual layer the hash was computed on. For instance, a hash computed 1464 * at L4 may be considered an L3 hash. This should only be done if the 1465 * driver can't unambiguously determine that the HW computed the hash at 1466 * the higher layer. Note that the "should" in the second property above 1467 * permits this. 1468 */ 1469 enum pkt_hash_types { 1470 PKT_HASH_TYPE_NONE, /* Undefined type */ 1471 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 1472 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 1473 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 1474 }; 1475 1476 static inline void skb_clear_hash(struct sk_buff *skb) 1477 { 1478 skb->hash = 0; 1479 skb->sw_hash = 0; 1480 skb->l4_hash = 0; 1481 } 1482 1483 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 1484 { 1485 if (!skb->l4_hash) 1486 skb_clear_hash(skb); 1487 } 1488 1489 static inline void 1490 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4) 1491 { 1492 skb->l4_hash = is_l4; 1493 skb->sw_hash = is_sw; 1494 skb->hash = hash; 1495 } 1496 1497 static inline void 1498 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 1499 { 1500 /* Used by drivers to set hash from HW */ 1501 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4); 1502 } 1503 1504 static inline void 1505 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4) 1506 { 1507 __skb_set_hash(skb, hash, true, is_l4); 1508 } 1509 1510 u32 __skb_get_hash_symmetric_net(const struct net *net, const struct sk_buff *skb); 1511 1512 static inline u32 __skb_get_hash_symmetric(const struct sk_buff *skb) 1513 { 1514 return __skb_get_hash_symmetric_net(NULL, skb); 1515 } 1516 1517 void __skb_get_hash_net(const struct net *net, struct sk_buff *skb); 1518 u32 skb_get_poff(const struct sk_buff *skb); 1519 u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1520 const struct flow_keys_basic *keys, int hlen); 1521 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 1522 const void *data, int hlen_proto); 1523 1524 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, 1525 int thoff, u8 ip_proto) 1526 { 1527 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0); 1528 } 1529 1530 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 1531 const struct flow_dissector_key *key, 1532 unsigned int key_count); 1533 1534 struct bpf_flow_dissector; 1535 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 1536 __be16 proto, int nhoff, int hlen, unsigned int flags); 1537 1538 bool __skb_flow_dissect(const struct net *net, 1539 const struct sk_buff *skb, 1540 struct flow_dissector *flow_dissector, 1541 void *target_container, const void *data, 1542 __be16 proto, int nhoff, int hlen, unsigned int flags); 1543 1544 static inline bool skb_flow_dissect(const struct sk_buff *skb, 1545 struct flow_dissector *flow_dissector, 1546 void *target_container, unsigned int flags) 1547 { 1548 return __skb_flow_dissect(NULL, skb, flow_dissector, 1549 target_container, NULL, 0, 0, 0, flags); 1550 } 1551 1552 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb, 1553 struct flow_keys *flow, 1554 unsigned int flags) 1555 { 1556 memset(flow, 0, sizeof(*flow)); 1557 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector, 1558 flow, NULL, 0, 0, 0, flags); 1559 } 1560 1561 static inline bool 1562 skb_flow_dissect_flow_keys_basic(const struct net *net, 1563 const struct sk_buff *skb, 1564 struct flow_keys_basic *flow, 1565 const void *data, __be16 proto, 1566 int nhoff, int hlen, unsigned int flags) 1567 { 1568 memset(flow, 0, sizeof(*flow)); 1569 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow, 1570 data, proto, nhoff, hlen, flags); 1571 } 1572 1573 void skb_flow_dissect_meta(const struct sk_buff *skb, 1574 struct flow_dissector *flow_dissector, 1575 void *target_container); 1576 1577 /* Gets a skb connection tracking info, ctinfo map should be a 1578 * map of mapsize to translate enum ip_conntrack_info states 1579 * to user states. 1580 */ 1581 void 1582 skb_flow_dissect_ct(const struct sk_buff *skb, 1583 struct flow_dissector *flow_dissector, 1584 void *target_container, 1585 u16 *ctinfo_map, size_t mapsize, 1586 bool post_ct, u16 zone); 1587 void 1588 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 1589 struct flow_dissector *flow_dissector, 1590 void *target_container); 1591 1592 void skb_flow_dissect_hash(const struct sk_buff *skb, 1593 struct flow_dissector *flow_dissector, 1594 void *target_container); 1595 1596 static inline __u32 skb_get_hash_net(const struct net *net, struct sk_buff *skb) 1597 { 1598 if (!skb->l4_hash && !skb->sw_hash) 1599 __skb_get_hash_net(net, skb); 1600 1601 return skb->hash; 1602 } 1603 1604 static inline __u32 skb_get_hash(struct sk_buff *skb) 1605 { 1606 if (!skb->l4_hash && !skb->sw_hash) 1607 __skb_get_hash_net(NULL, skb); 1608 1609 return skb->hash; 1610 } 1611 1612 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 1613 { 1614 if (!skb->l4_hash && !skb->sw_hash) { 1615 struct flow_keys keys; 1616 __u32 hash = __get_hash_from_flowi6(fl6, &keys); 1617 1618 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1619 } 1620 1621 return skb->hash; 1622 } 1623 1624 __u32 skb_get_hash_perturb(const struct sk_buff *skb, 1625 const siphash_key_t *perturb); 1626 1627 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 1628 { 1629 return skb->hash; 1630 } 1631 1632 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 1633 { 1634 to->hash = from->hash; 1635 to->sw_hash = from->sw_hash; 1636 to->l4_hash = from->l4_hash; 1637 }; 1638 1639 static inline int skb_cmp_decrypted(const struct sk_buff *skb1, 1640 const struct sk_buff *skb2) 1641 { 1642 #ifdef CONFIG_SKB_DECRYPTED 1643 return skb2->decrypted - skb1->decrypted; 1644 #else 1645 return 0; 1646 #endif 1647 } 1648 1649 static inline bool skb_is_decrypted(const struct sk_buff *skb) 1650 { 1651 #ifdef CONFIG_SKB_DECRYPTED 1652 return skb->decrypted; 1653 #else 1654 return false; 1655 #endif 1656 } 1657 1658 static inline void skb_copy_decrypted(struct sk_buff *to, 1659 const struct sk_buff *from) 1660 { 1661 #ifdef CONFIG_SKB_DECRYPTED 1662 to->decrypted = from->decrypted; 1663 #endif 1664 } 1665 1666 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1667 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1668 { 1669 return skb->head + skb->end; 1670 } 1671 1672 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1673 { 1674 return skb->end; 1675 } 1676 1677 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1678 { 1679 skb->end = offset; 1680 } 1681 #else 1682 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1683 { 1684 return skb->end; 1685 } 1686 1687 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1688 { 1689 return skb->end - skb->head; 1690 } 1691 1692 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1693 { 1694 skb->end = skb->head + offset; 1695 } 1696 #endif 1697 1698 extern const struct ubuf_info_ops msg_zerocopy_ubuf_ops; 1699 1700 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, 1701 struct ubuf_info *uarg); 1702 1703 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); 1704 1705 int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, 1706 struct sk_buff *skb, struct iov_iter *from, 1707 size_t length); 1708 1709 int zerocopy_fill_skb_from_iter(struct sk_buff *skb, 1710 struct iov_iter *from, size_t length); 1711 1712 static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, 1713 struct msghdr *msg, int len) 1714 { 1715 return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len); 1716 } 1717 1718 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, 1719 struct msghdr *msg, int len, 1720 struct ubuf_info *uarg); 1721 1722 /* Internal */ 1723 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 1724 1725 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 1726 { 1727 return &skb_shinfo(skb)->hwtstamps; 1728 } 1729 1730 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb) 1731 { 1732 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE; 1733 1734 return is_zcopy ? skb_uarg(skb) : NULL; 1735 } 1736 1737 static inline bool skb_zcopy_pure(const struct sk_buff *skb) 1738 { 1739 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY; 1740 } 1741 1742 static inline bool skb_zcopy_managed(const struct sk_buff *skb) 1743 { 1744 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS; 1745 } 1746 1747 static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1, 1748 const struct sk_buff *skb2) 1749 { 1750 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2); 1751 } 1752 1753 static inline void net_zcopy_get(struct ubuf_info *uarg) 1754 { 1755 refcount_inc(&uarg->refcnt); 1756 } 1757 1758 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg) 1759 { 1760 skb_shinfo(skb)->destructor_arg = uarg; 1761 skb_shinfo(skb)->flags |= uarg->flags; 1762 } 1763 1764 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, 1765 bool *have_ref) 1766 { 1767 if (skb && uarg && !skb_zcopy(skb)) { 1768 if (unlikely(have_ref && *have_ref)) 1769 *have_ref = false; 1770 else 1771 net_zcopy_get(uarg); 1772 skb_zcopy_init(skb, uarg); 1773 } 1774 } 1775 1776 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val) 1777 { 1778 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL); 1779 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG; 1780 } 1781 1782 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb) 1783 { 1784 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL; 1785 } 1786 1787 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb) 1788 { 1789 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL); 1790 } 1791 1792 static inline void net_zcopy_put(struct ubuf_info *uarg) 1793 { 1794 if (uarg) 1795 uarg->ops->complete(NULL, uarg, true); 1796 } 1797 1798 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref) 1799 { 1800 if (uarg) { 1801 if (uarg->ops == &msg_zerocopy_ubuf_ops) 1802 msg_zerocopy_put_abort(uarg, have_uref); 1803 else if (have_uref) 1804 net_zcopy_put(uarg); 1805 } 1806 } 1807 1808 /* Release a reference on a zerocopy structure */ 1809 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success) 1810 { 1811 struct ubuf_info *uarg = skb_zcopy(skb); 1812 1813 if (uarg) { 1814 if (!skb_zcopy_is_nouarg(skb)) 1815 uarg->ops->complete(skb, uarg, zerocopy_success); 1816 1817 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY; 1818 } 1819 } 1820 1821 void __skb_zcopy_downgrade_managed(struct sk_buff *skb); 1822 1823 static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) 1824 { 1825 if (unlikely(skb_zcopy_managed(skb))) 1826 __skb_zcopy_downgrade_managed(skb); 1827 } 1828 1829 /* Return true if frags in this skb are readable by the host. */ 1830 static inline bool skb_frags_readable(const struct sk_buff *skb) 1831 { 1832 return !skb->unreadable; 1833 } 1834 1835 static inline void skb_mark_not_on_list(struct sk_buff *skb) 1836 { 1837 skb->next = NULL; 1838 } 1839 1840 static inline void skb_poison_list(struct sk_buff *skb) 1841 { 1842 #ifdef CONFIG_DEBUG_NET 1843 skb->next = SKB_LIST_POISON_NEXT; 1844 #endif 1845 } 1846 1847 /* Iterate through singly-linked GSO fragments of an skb. */ 1848 #define skb_list_walk_safe(first, skb, next_skb) \ 1849 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \ 1850 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL) 1851 1852 static inline void skb_list_del_init(struct sk_buff *skb) 1853 { 1854 __list_del_entry(&skb->list); 1855 skb_mark_not_on_list(skb); 1856 } 1857 1858 /** 1859 * skb_queue_empty - check if a queue is empty 1860 * @list: queue head 1861 * 1862 * Returns true if the queue is empty, false otherwise. 1863 */ 1864 static inline int skb_queue_empty(const struct sk_buff_head *list) 1865 { 1866 return list->next == (const struct sk_buff *) list; 1867 } 1868 1869 /** 1870 * skb_queue_empty_lockless - check if a queue is empty 1871 * @list: queue head 1872 * 1873 * Returns true if the queue is empty, false otherwise. 1874 * This variant can be used in lockless contexts. 1875 */ 1876 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list) 1877 { 1878 return READ_ONCE(list->next) == (const struct sk_buff *) list; 1879 } 1880 1881 1882 /** 1883 * skb_queue_is_last - check if skb is the last entry in the queue 1884 * @list: queue head 1885 * @skb: buffer 1886 * 1887 * Returns true if @skb is the last buffer on the list. 1888 */ 1889 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 1890 const struct sk_buff *skb) 1891 { 1892 return skb->next == (const struct sk_buff *) list; 1893 } 1894 1895 /** 1896 * skb_queue_is_first - check if skb is the first entry in the queue 1897 * @list: queue head 1898 * @skb: buffer 1899 * 1900 * Returns true if @skb is the first buffer on the list. 1901 */ 1902 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 1903 const struct sk_buff *skb) 1904 { 1905 return skb->prev == (const struct sk_buff *) list; 1906 } 1907 1908 /** 1909 * skb_queue_next - return the next packet in the queue 1910 * @list: queue head 1911 * @skb: current buffer 1912 * 1913 * Return the next packet in @list after @skb. It is only valid to 1914 * call this if skb_queue_is_last() evaluates to false. 1915 */ 1916 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 1917 const struct sk_buff *skb) 1918 { 1919 /* This BUG_ON may seem severe, but if we just return then we 1920 * are going to dereference garbage. 1921 */ 1922 BUG_ON(skb_queue_is_last(list, skb)); 1923 return skb->next; 1924 } 1925 1926 /** 1927 * skb_queue_prev - return the prev packet in the queue 1928 * @list: queue head 1929 * @skb: current buffer 1930 * 1931 * Return the prev packet in @list before @skb. It is only valid to 1932 * call this if skb_queue_is_first() evaluates to false. 1933 */ 1934 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 1935 const struct sk_buff *skb) 1936 { 1937 /* This BUG_ON may seem severe, but if we just return then we 1938 * are going to dereference garbage. 1939 */ 1940 BUG_ON(skb_queue_is_first(list, skb)); 1941 return skb->prev; 1942 } 1943 1944 /** 1945 * skb_get - reference buffer 1946 * @skb: buffer to reference 1947 * 1948 * Makes another reference to a socket buffer and returns a pointer 1949 * to the buffer. 1950 */ 1951 static inline struct sk_buff *skb_get(struct sk_buff *skb) 1952 { 1953 refcount_inc(&skb->users); 1954 return skb; 1955 } 1956 1957 /* 1958 * If users == 1, we are the only owner and can avoid redundant atomic changes. 1959 */ 1960 1961 /** 1962 * skb_cloned - is the buffer a clone 1963 * @skb: buffer to check 1964 * 1965 * Returns true if the buffer was generated with skb_clone() and is 1966 * one of multiple shared copies of the buffer. Cloned buffers are 1967 * shared data so must not be written to under normal circumstances. 1968 */ 1969 static inline int skb_cloned(const struct sk_buff *skb) 1970 { 1971 return skb->cloned && 1972 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 1973 } 1974 1975 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 1976 { 1977 might_sleep_if(gfpflags_allow_blocking(pri)); 1978 1979 if (skb_cloned(skb)) 1980 return pskb_expand_head(skb, 0, 0, pri); 1981 1982 return 0; 1983 } 1984 1985 /* This variant of skb_unclone() makes sure skb->truesize 1986 * and skb_end_offset() are not changed, whenever a new skb->head is needed. 1987 * 1988 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X)) 1989 * when various debugging features are in place. 1990 */ 1991 int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri); 1992 static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri) 1993 { 1994 might_sleep_if(gfpflags_allow_blocking(pri)); 1995 1996 if (skb_cloned(skb)) 1997 return __skb_unclone_keeptruesize(skb, pri); 1998 return 0; 1999 } 2000 2001 /** 2002 * skb_header_cloned - is the header a clone 2003 * @skb: buffer to check 2004 * 2005 * Returns true if modifying the header part of the buffer requires 2006 * the data to be copied. 2007 */ 2008 static inline int skb_header_cloned(const struct sk_buff *skb) 2009 { 2010 int dataref; 2011 2012 if (!skb->cloned) 2013 return 0; 2014 2015 dataref = atomic_read(&skb_shinfo(skb)->dataref); 2016 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 2017 return dataref != 1; 2018 } 2019 2020 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri) 2021 { 2022 might_sleep_if(gfpflags_allow_blocking(pri)); 2023 2024 if (skb_header_cloned(skb)) 2025 return pskb_expand_head(skb, 0, 0, pri); 2026 2027 return 0; 2028 } 2029 2030 /** 2031 * __skb_header_release() - allow clones to use the headroom 2032 * @skb: buffer to operate on 2033 * 2034 * See "DOC: dataref and headerless skbs". 2035 */ 2036 static inline void __skb_header_release(struct sk_buff *skb) 2037 { 2038 skb->nohdr = 1; 2039 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT)); 2040 } 2041 2042 2043 /** 2044 * skb_shared - is the buffer shared 2045 * @skb: buffer to check 2046 * 2047 * Returns true if more than one person has a reference to this 2048 * buffer. 2049 */ 2050 static inline int skb_shared(const struct sk_buff *skb) 2051 { 2052 return refcount_read(&skb->users) != 1; 2053 } 2054 2055 /** 2056 * skb_share_check - check if buffer is shared and if so clone it 2057 * @skb: buffer to check 2058 * @pri: priority for memory allocation 2059 * 2060 * If the buffer is shared the buffer is cloned and the old copy 2061 * drops a reference. A new clone with a single reference is returned. 2062 * If the buffer is not shared the original buffer is returned. When 2063 * being called from interrupt status or with spinlocks held pri must 2064 * be GFP_ATOMIC. 2065 * 2066 * NULL is returned on a memory allocation failure. 2067 */ 2068 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 2069 { 2070 might_sleep_if(gfpflags_allow_blocking(pri)); 2071 if (skb_shared(skb)) { 2072 struct sk_buff *nskb = skb_clone(skb, pri); 2073 2074 if (likely(nskb)) 2075 consume_skb(skb); 2076 else 2077 kfree_skb(skb); 2078 skb = nskb; 2079 } 2080 return skb; 2081 } 2082 2083 /* 2084 * Copy shared buffers into a new sk_buff. We effectively do COW on 2085 * packets to handle cases where we have a local reader and forward 2086 * and a couple of other messy ones. The normal one is tcpdumping 2087 * a packet that's being forwarded. 2088 */ 2089 2090 /** 2091 * skb_unshare - make a copy of a shared buffer 2092 * @skb: buffer to check 2093 * @pri: priority for memory allocation 2094 * 2095 * If the socket buffer is a clone then this function creates a new 2096 * copy of the data, drops a reference count on the old copy and returns 2097 * the new copy with the reference count at 1. If the buffer is not a clone 2098 * the original buffer is returned. When called with a spinlock held or 2099 * from interrupt state @pri must be %GFP_ATOMIC 2100 * 2101 * %NULL is returned on a memory allocation failure. 2102 */ 2103 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 2104 gfp_t pri) 2105 { 2106 might_sleep_if(gfpflags_allow_blocking(pri)); 2107 if (skb_cloned(skb)) { 2108 struct sk_buff *nskb = skb_copy(skb, pri); 2109 2110 /* Free our shared copy */ 2111 if (likely(nskb)) 2112 consume_skb(skb); 2113 else 2114 kfree_skb(skb); 2115 skb = nskb; 2116 } 2117 return skb; 2118 } 2119 2120 /** 2121 * skb_peek - peek at the head of an &sk_buff_head 2122 * @list_: list to peek at 2123 * 2124 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2125 * be careful with this one. A peek leaves the buffer on the 2126 * list and someone else may run off with it. You must hold 2127 * the appropriate locks or have a private queue to do this. 2128 * 2129 * Returns %NULL for an empty list or a pointer to the head element. 2130 * The reference count is not incremented and the reference is therefore 2131 * volatile. Use with caution. 2132 */ 2133 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 2134 { 2135 struct sk_buff *skb = list_->next; 2136 2137 if (skb == (struct sk_buff *)list_) 2138 skb = NULL; 2139 return skb; 2140 } 2141 2142 /** 2143 * __skb_peek - peek at the head of a non-empty &sk_buff_head 2144 * @list_: list to peek at 2145 * 2146 * Like skb_peek(), but the caller knows that the list is not empty. 2147 */ 2148 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_) 2149 { 2150 return list_->next; 2151 } 2152 2153 /** 2154 * skb_peek_next - peek skb following the given one from a queue 2155 * @skb: skb to start from 2156 * @list_: list to peek at 2157 * 2158 * Returns %NULL when the end of the list is met or a pointer to the 2159 * next element. The reference count is not incremented and the 2160 * reference is therefore volatile. Use with caution. 2161 */ 2162 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 2163 const struct sk_buff_head *list_) 2164 { 2165 struct sk_buff *next = skb->next; 2166 2167 if (next == (struct sk_buff *)list_) 2168 next = NULL; 2169 return next; 2170 } 2171 2172 /** 2173 * skb_peek_tail - peek at the tail of an &sk_buff_head 2174 * @list_: list to peek at 2175 * 2176 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2177 * be careful with this one. A peek leaves the buffer on the 2178 * list and someone else may run off with it. You must hold 2179 * the appropriate locks or have a private queue to do this. 2180 * 2181 * Returns %NULL for an empty list or a pointer to the tail element. 2182 * The reference count is not incremented and the reference is therefore 2183 * volatile. Use with caution. 2184 */ 2185 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 2186 { 2187 struct sk_buff *skb = READ_ONCE(list_->prev); 2188 2189 if (skb == (struct sk_buff *)list_) 2190 skb = NULL; 2191 return skb; 2192 2193 } 2194 2195 /** 2196 * skb_queue_len - get queue length 2197 * @list_: list to measure 2198 * 2199 * Return the length of an &sk_buff queue. 2200 */ 2201 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 2202 { 2203 return list_->qlen; 2204 } 2205 2206 /** 2207 * skb_queue_len_lockless - get queue length 2208 * @list_: list to measure 2209 * 2210 * Return the length of an &sk_buff queue. 2211 * This variant can be used in lockless contexts. 2212 */ 2213 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_) 2214 { 2215 return READ_ONCE(list_->qlen); 2216 } 2217 2218 /** 2219 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 2220 * @list: queue to initialize 2221 * 2222 * This initializes only the list and queue length aspects of 2223 * an sk_buff_head object. This allows to initialize the list 2224 * aspects of an sk_buff_head without reinitializing things like 2225 * the spinlock. It can also be used for on-stack sk_buff_head 2226 * objects where the spinlock is known to not be used. 2227 */ 2228 static inline void __skb_queue_head_init(struct sk_buff_head *list) 2229 { 2230 list->prev = list->next = (struct sk_buff *)list; 2231 list->qlen = 0; 2232 } 2233 2234 /* 2235 * This function creates a split out lock class for each invocation; 2236 * this is needed for now since a whole lot of users of the skb-queue 2237 * infrastructure in drivers have different locking usage (in hardirq) 2238 * than the networking core (in softirq only). In the long run either the 2239 * network layer or drivers should need annotation to consolidate the 2240 * main types of usage into 3 classes. 2241 */ 2242 static inline void skb_queue_head_init(struct sk_buff_head *list) 2243 { 2244 spin_lock_init(&list->lock); 2245 __skb_queue_head_init(list); 2246 } 2247 2248 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 2249 struct lock_class_key *class) 2250 { 2251 skb_queue_head_init(list); 2252 lockdep_set_class(&list->lock, class); 2253 } 2254 2255 /* 2256 * Insert an sk_buff on a list. 2257 * 2258 * The "__skb_xxxx()" functions are the non-atomic ones that 2259 * can only be called with interrupts disabled. 2260 */ 2261 static inline void __skb_insert(struct sk_buff *newsk, 2262 struct sk_buff *prev, struct sk_buff *next, 2263 struct sk_buff_head *list) 2264 { 2265 /* See skb_queue_empty_lockless() and skb_peek_tail() 2266 * for the opposite READ_ONCE() 2267 */ 2268 WRITE_ONCE(newsk->next, next); 2269 WRITE_ONCE(newsk->prev, prev); 2270 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk); 2271 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk); 2272 WRITE_ONCE(list->qlen, list->qlen + 1); 2273 } 2274 2275 static inline void __skb_queue_splice(const struct sk_buff_head *list, 2276 struct sk_buff *prev, 2277 struct sk_buff *next) 2278 { 2279 struct sk_buff *first = list->next; 2280 struct sk_buff *last = list->prev; 2281 2282 WRITE_ONCE(first->prev, prev); 2283 WRITE_ONCE(prev->next, first); 2284 2285 WRITE_ONCE(last->next, next); 2286 WRITE_ONCE(next->prev, last); 2287 } 2288 2289 /** 2290 * skb_queue_splice - join two skb lists, this is designed for stacks 2291 * @list: the new list to add 2292 * @head: the place to add it in the first list 2293 */ 2294 static inline void skb_queue_splice(const struct sk_buff_head *list, 2295 struct sk_buff_head *head) 2296 { 2297 if (!skb_queue_empty(list)) { 2298 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2299 head->qlen += list->qlen; 2300 } 2301 } 2302 2303 /** 2304 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 2305 * @list: the new list to add 2306 * @head: the place to add it in the first list 2307 * 2308 * The list at @list is reinitialised 2309 */ 2310 static inline void skb_queue_splice_init(struct sk_buff_head *list, 2311 struct sk_buff_head *head) 2312 { 2313 if (!skb_queue_empty(list)) { 2314 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2315 head->qlen += list->qlen; 2316 __skb_queue_head_init(list); 2317 } 2318 } 2319 2320 /** 2321 * skb_queue_splice_tail - join two skb lists, each list being a queue 2322 * @list: the new list to add 2323 * @head: the place to add it in the first list 2324 */ 2325 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 2326 struct sk_buff_head *head) 2327 { 2328 if (!skb_queue_empty(list)) { 2329 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2330 head->qlen += list->qlen; 2331 } 2332 } 2333 2334 /** 2335 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 2336 * @list: the new list to add 2337 * @head: the place to add it in the first list 2338 * 2339 * Each of the lists is a queue. 2340 * The list at @list is reinitialised 2341 */ 2342 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 2343 struct sk_buff_head *head) 2344 { 2345 if (!skb_queue_empty(list)) { 2346 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2347 head->qlen += list->qlen; 2348 __skb_queue_head_init(list); 2349 } 2350 } 2351 2352 /** 2353 * __skb_queue_after - queue a buffer at the list head 2354 * @list: list to use 2355 * @prev: place after this buffer 2356 * @newsk: buffer to queue 2357 * 2358 * Queue a buffer int the middle of a list. This function takes no locks 2359 * and you must therefore hold required locks before calling it. 2360 * 2361 * A buffer cannot be placed on two lists at the same time. 2362 */ 2363 static inline void __skb_queue_after(struct sk_buff_head *list, 2364 struct sk_buff *prev, 2365 struct sk_buff *newsk) 2366 { 2367 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list); 2368 } 2369 2370 void skb_append(struct sk_buff *old, struct sk_buff *newsk, 2371 struct sk_buff_head *list); 2372 2373 static inline void __skb_queue_before(struct sk_buff_head *list, 2374 struct sk_buff *next, 2375 struct sk_buff *newsk) 2376 { 2377 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list); 2378 } 2379 2380 /** 2381 * __skb_queue_head - queue a buffer at the list head 2382 * @list: list to use 2383 * @newsk: buffer to queue 2384 * 2385 * Queue a buffer at the start of a list. This function takes no locks 2386 * and you must therefore hold required locks before calling it. 2387 * 2388 * A buffer cannot be placed on two lists at the same time. 2389 */ 2390 static inline void __skb_queue_head(struct sk_buff_head *list, 2391 struct sk_buff *newsk) 2392 { 2393 __skb_queue_after(list, (struct sk_buff *)list, newsk); 2394 } 2395 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 2396 2397 /** 2398 * __skb_queue_tail - queue a buffer at the list tail 2399 * @list: list to use 2400 * @newsk: buffer to queue 2401 * 2402 * Queue a buffer at the end of a list. This function takes no locks 2403 * and you must therefore hold required locks before calling it. 2404 * 2405 * A buffer cannot be placed on two lists at the same time. 2406 */ 2407 static inline void __skb_queue_tail(struct sk_buff_head *list, 2408 struct sk_buff *newsk) 2409 { 2410 __skb_queue_before(list, (struct sk_buff *)list, newsk); 2411 } 2412 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 2413 2414 /* 2415 * remove sk_buff from list. _Must_ be called atomically, and with 2416 * the list known.. 2417 */ 2418 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 2419 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 2420 { 2421 struct sk_buff *next, *prev; 2422 2423 WRITE_ONCE(list->qlen, list->qlen - 1); 2424 next = skb->next; 2425 prev = skb->prev; 2426 skb->next = skb->prev = NULL; 2427 WRITE_ONCE(next->prev, prev); 2428 WRITE_ONCE(prev->next, next); 2429 } 2430 2431 /** 2432 * __skb_dequeue - remove from the head of the queue 2433 * @list: list to dequeue from 2434 * 2435 * Remove the head of the list. This function does not take any locks 2436 * so must be used with appropriate locks held only. The head item is 2437 * returned or %NULL if the list is empty. 2438 */ 2439 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 2440 { 2441 struct sk_buff *skb = skb_peek(list); 2442 if (skb) 2443 __skb_unlink(skb, list); 2444 return skb; 2445 } 2446 struct sk_buff *skb_dequeue(struct sk_buff_head *list); 2447 2448 /** 2449 * __skb_dequeue_tail - remove from the tail of the queue 2450 * @list: list to dequeue from 2451 * 2452 * Remove the tail of the list. This function does not take any locks 2453 * so must be used with appropriate locks held only. The tail item is 2454 * returned or %NULL if the list is empty. 2455 */ 2456 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 2457 { 2458 struct sk_buff *skb = skb_peek_tail(list); 2459 if (skb) 2460 __skb_unlink(skb, list); 2461 return skb; 2462 } 2463 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 2464 2465 2466 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 2467 { 2468 return skb->data_len; 2469 } 2470 2471 static inline unsigned int skb_headlen(const struct sk_buff *skb) 2472 { 2473 return skb->len - skb->data_len; 2474 } 2475 2476 static inline unsigned int __skb_pagelen(const struct sk_buff *skb) 2477 { 2478 unsigned int i, len = 0; 2479 2480 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--) 2481 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 2482 return len; 2483 } 2484 2485 static inline unsigned int skb_pagelen(const struct sk_buff *skb) 2486 { 2487 return skb_headlen(skb) + __skb_pagelen(skb); 2488 } 2489 2490 static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag, 2491 netmem_ref netmem, int off, 2492 int size) 2493 { 2494 frag->netmem = netmem; 2495 frag->offset = off; 2496 skb_frag_size_set(frag, size); 2497 } 2498 2499 static inline void skb_frag_fill_page_desc(skb_frag_t *frag, 2500 struct page *page, 2501 int off, int size) 2502 { 2503 skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size); 2504 } 2505 2506 static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo, 2507 int i, netmem_ref netmem, 2508 int off, int size) 2509 { 2510 skb_frag_t *frag = &shinfo->frags[i]; 2511 2512 skb_frag_fill_netmem_desc(frag, netmem, off, size); 2513 } 2514 2515 static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo, 2516 int i, struct page *page, 2517 int off, int size) 2518 { 2519 __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off, 2520 size); 2521 } 2522 2523 /** 2524 * skb_len_add - adds a number to len fields of skb 2525 * @skb: buffer to add len to 2526 * @delta: number of bytes to add 2527 */ 2528 static inline void skb_len_add(struct sk_buff *skb, int delta) 2529 { 2530 skb->len += delta; 2531 skb->data_len += delta; 2532 skb->truesize += delta; 2533 } 2534 2535 /** 2536 * __skb_fill_netmem_desc - initialise a fragment in an skb 2537 * @skb: buffer containing fragment to be initialised 2538 * @i: fragment index to initialise 2539 * @netmem: the netmem to use for this fragment 2540 * @off: the offset to the data with @page 2541 * @size: the length of the data 2542 * 2543 * Initialises the @i'th fragment of @skb to point to &size bytes at 2544 * offset @off within @page. 2545 * 2546 * Does not take any additional reference on the fragment. 2547 */ 2548 static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i, 2549 netmem_ref netmem, int off, int size) 2550 { 2551 struct page *page; 2552 2553 __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size); 2554 2555 if (netmem_is_net_iov(netmem)) { 2556 skb->unreadable = true; 2557 return; 2558 } 2559 2560 page = netmem_to_page(netmem); 2561 2562 /* Propagate page pfmemalloc to the skb if we can. The problem is 2563 * that not all callers have unique ownership of the page but rely 2564 * on page_is_pfmemalloc doing the right thing(tm). 2565 */ 2566 page = compound_head(page); 2567 if (page_is_pfmemalloc(page)) 2568 skb->pfmemalloc = true; 2569 } 2570 2571 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 2572 struct page *page, int off, int size) 2573 { 2574 __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); 2575 } 2576 2577 static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i, 2578 netmem_ref netmem, int off, int size) 2579 { 2580 __skb_fill_netmem_desc(skb, i, netmem, off, size); 2581 skb_shinfo(skb)->nr_frags = i + 1; 2582 } 2583 2584 /** 2585 * skb_fill_page_desc - initialise a paged fragment in an skb 2586 * @skb: buffer containing fragment to be initialised 2587 * @i: paged fragment index to initialise 2588 * @page: the page to use for this fragment 2589 * @off: the offset to the data with @page 2590 * @size: the length of the data 2591 * 2592 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 2593 * @skb to point to @size bytes at offset @off within @page. In 2594 * addition updates @skb such that @i is the last fragment. 2595 * 2596 * Does not take any additional reference on the fragment. 2597 */ 2598 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 2599 struct page *page, int off, int size) 2600 { 2601 skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); 2602 } 2603 2604 /** 2605 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb 2606 * @skb: buffer containing fragment to be initialised 2607 * @i: paged fragment index to initialise 2608 * @page: the page to use for this fragment 2609 * @off: the offset to the data with @page 2610 * @size: the length of the data 2611 * 2612 * Variant of skb_fill_page_desc() which does not deal with 2613 * pfmemalloc, if page is not owned by us. 2614 */ 2615 static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i, 2616 struct page *page, int off, 2617 int size) 2618 { 2619 struct skb_shared_info *shinfo = skb_shinfo(skb); 2620 2621 __skb_fill_page_desc_noacc(shinfo, i, page, off, size); 2622 shinfo->nr_frags = i + 1; 2623 } 2624 2625 void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem, 2626 int off, int size, unsigned int truesize); 2627 2628 static inline void skb_add_rx_frag(struct sk_buff *skb, int i, 2629 struct page *page, int off, int size, 2630 unsigned int truesize) 2631 { 2632 skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size, 2633 truesize); 2634 } 2635 2636 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 2637 unsigned int truesize); 2638 2639 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 2640 2641 #ifdef NET_SKBUFF_DATA_USES_OFFSET 2642 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2643 { 2644 return skb->head + skb->tail; 2645 } 2646 2647 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2648 { 2649 skb->tail = skb->data - skb->head; 2650 } 2651 2652 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2653 { 2654 skb_reset_tail_pointer(skb); 2655 skb->tail += offset; 2656 } 2657 2658 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 2659 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2660 { 2661 return skb->tail; 2662 } 2663 2664 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2665 { 2666 skb->tail = skb->data; 2667 } 2668 2669 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2670 { 2671 skb->tail = skb->data + offset; 2672 } 2673 2674 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 2675 2676 static inline void skb_assert_len(struct sk_buff *skb) 2677 { 2678 #ifdef CONFIG_DEBUG_NET 2679 if (WARN_ONCE(!skb->len, "%s\n", __func__)) 2680 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); 2681 #endif /* CONFIG_DEBUG_NET */ 2682 } 2683 2684 /* 2685 * Add data to an sk_buff 2686 */ 2687 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 2688 void *skb_put(struct sk_buff *skb, unsigned int len); 2689 static inline void *__skb_put(struct sk_buff *skb, unsigned int len) 2690 { 2691 void *tmp = skb_tail_pointer(skb); 2692 SKB_LINEAR_ASSERT(skb); 2693 skb->tail += len; 2694 skb->len += len; 2695 return tmp; 2696 } 2697 2698 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len) 2699 { 2700 void *tmp = __skb_put(skb, len); 2701 2702 memset(tmp, 0, len); 2703 return tmp; 2704 } 2705 2706 static inline void *__skb_put_data(struct sk_buff *skb, const void *data, 2707 unsigned int len) 2708 { 2709 void *tmp = __skb_put(skb, len); 2710 2711 memcpy(tmp, data, len); 2712 return tmp; 2713 } 2714 2715 static inline void __skb_put_u8(struct sk_buff *skb, u8 val) 2716 { 2717 *(u8 *)__skb_put(skb, 1) = val; 2718 } 2719 2720 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len) 2721 { 2722 void *tmp = skb_put(skb, len); 2723 2724 memset(tmp, 0, len); 2725 2726 return tmp; 2727 } 2728 2729 static inline void *skb_put_data(struct sk_buff *skb, const void *data, 2730 unsigned int len) 2731 { 2732 void *tmp = skb_put(skb, len); 2733 2734 memcpy(tmp, data, len); 2735 2736 return tmp; 2737 } 2738 2739 static inline void skb_put_u8(struct sk_buff *skb, u8 val) 2740 { 2741 *(u8 *)skb_put(skb, 1) = val; 2742 } 2743 2744 void *skb_push(struct sk_buff *skb, unsigned int len); 2745 static inline void *__skb_push(struct sk_buff *skb, unsigned int len) 2746 { 2747 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2748 2749 skb->data -= len; 2750 skb->len += len; 2751 return skb->data; 2752 } 2753 2754 void *skb_pull(struct sk_buff *skb, unsigned int len); 2755 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) 2756 { 2757 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2758 2759 skb->len -= len; 2760 if (unlikely(skb->len < skb->data_len)) { 2761 #if defined(CONFIG_DEBUG_NET) 2762 skb->len += len; 2763 pr_err("__skb_pull(len=%u)\n", len); 2764 skb_dump(KERN_ERR, skb, false); 2765 #endif 2766 BUG(); 2767 } 2768 return skb->data += len; 2769 } 2770 2771 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len) 2772 { 2773 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 2774 } 2775 2776 void *skb_pull_data(struct sk_buff *skb, size_t len); 2777 2778 void *__pskb_pull_tail(struct sk_buff *skb, int delta); 2779 2780 static inline enum skb_drop_reason 2781 pskb_may_pull_reason(struct sk_buff *skb, unsigned int len) 2782 { 2783 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2784 2785 if (likely(len <= skb_headlen(skb))) 2786 return SKB_NOT_DROPPED_YET; 2787 2788 if (unlikely(len > skb->len)) 2789 return SKB_DROP_REASON_PKT_TOO_SMALL; 2790 2791 if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb)))) 2792 return SKB_DROP_REASON_NOMEM; 2793 2794 return SKB_NOT_DROPPED_YET; 2795 } 2796 2797 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len) 2798 { 2799 return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET; 2800 } 2801 2802 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len) 2803 { 2804 if (!pskb_may_pull(skb, len)) 2805 return NULL; 2806 2807 skb->len -= len; 2808 return skb->data += len; 2809 } 2810 2811 void skb_condense(struct sk_buff *skb); 2812 2813 /** 2814 * skb_headroom - bytes at buffer head 2815 * @skb: buffer to check 2816 * 2817 * Return the number of bytes of free space at the head of an &sk_buff. 2818 */ 2819 static inline unsigned int skb_headroom(const struct sk_buff *skb) 2820 { 2821 return skb->data - skb->head; 2822 } 2823 2824 /** 2825 * skb_tailroom - bytes at buffer end 2826 * @skb: buffer to check 2827 * 2828 * Return the number of bytes of free space at the tail of an sk_buff 2829 */ 2830 static inline int skb_tailroom(const struct sk_buff *skb) 2831 { 2832 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 2833 } 2834 2835 /** 2836 * skb_availroom - bytes at buffer end 2837 * @skb: buffer to check 2838 * 2839 * Return the number of bytes of free space at the tail of an sk_buff 2840 * allocated by sk_stream_alloc() 2841 */ 2842 static inline int skb_availroom(const struct sk_buff *skb) 2843 { 2844 if (skb_is_nonlinear(skb)) 2845 return 0; 2846 2847 return skb->end - skb->tail - skb->reserved_tailroom; 2848 } 2849 2850 /** 2851 * skb_reserve - adjust headroom 2852 * @skb: buffer to alter 2853 * @len: bytes to move 2854 * 2855 * Increase the headroom of an empty &sk_buff by reducing the tail 2856 * room. This is only allowed for an empty buffer. 2857 */ 2858 static inline void skb_reserve(struct sk_buff *skb, int len) 2859 { 2860 skb->data += len; 2861 skb->tail += len; 2862 } 2863 2864 /** 2865 * skb_tailroom_reserve - adjust reserved_tailroom 2866 * @skb: buffer to alter 2867 * @mtu: maximum amount of headlen permitted 2868 * @needed_tailroom: minimum amount of reserved_tailroom 2869 * 2870 * Set reserved_tailroom so that headlen can be as large as possible but 2871 * not larger than mtu and tailroom cannot be smaller than 2872 * needed_tailroom. 2873 * The required headroom should already have been reserved before using 2874 * this function. 2875 */ 2876 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu, 2877 unsigned int needed_tailroom) 2878 { 2879 SKB_LINEAR_ASSERT(skb); 2880 if (mtu < skb_tailroom(skb) - needed_tailroom) 2881 /* use at most mtu */ 2882 skb->reserved_tailroom = skb_tailroom(skb) - mtu; 2883 else 2884 /* use up to all available space */ 2885 skb->reserved_tailroom = needed_tailroom; 2886 } 2887 2888 #define ENCAP_TYPE_ETHER 0 2889 #define ENCAP_TYPE_IPPROTO 1 2890 2891 static inline void skb_set_inner_protocol(struct sk_buff *skb, 2892 __be16 protocol) 2893 { 2894 skb->inner_protocol = protocol; 2895 skb->inner_protocol_type = ENCAP_TYPE_ETHER; 2896 } 2897 2898 static inline void skb_set_inner_ipproto(struct sk_buff *skb, 2899 __u8 ipproto) 2900 { 2901 skb->inner_ipproto = ipproto; 2902 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; 2903 } 2904 2905 static inline void skb_reset_inner_headers(struct sk_buff *skb) 2906 { 2907 skb->inner_mac_header = skb->mac_header; 2908 skb->inner_network_header = skb->network_header; 2909 skb->inner_transport_header = skb->transport_header; 2910 } 2911 2912 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 2913 { 2914 return skb->mac_header != (typeof(skb->mac_header))~0U; 2915 } 2916 2917 static inline void skb_reset_mac_len(struct sk_buff *skb) 2918 { 2919 if (!skb_mac_header_was_set(skb)) { 2920 DEBUG_NET_WARN_ON_ONCE(1); 2921 skb->mac_len = 0; 2922 } else { 2923 skb->mac_len = skb->network_header - skb->mac_header; 2924 } 2925 } 2926 2927 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 2928 *skb) 2929 { 2930 return skb->head + skb->inner_transport_header; 2931 } 2932 2933 static inline int skb_inner_transport_offset(const struct sk_buff *skb) 2934 { 2935 return skb_inner_transport_header(skb) - skb->data; 2936 } 2937 2938 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 2939 { 2940 long offset = skb->data - skb->head; 2941 2942 DEBUG_NET_WARN_ON_ONCE(offset != (typeof(skb->inner_transport_header))offset); 2943 skb->inner_transport_header = offset; 2944 } 2945 2946 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 2947 const int offset) 2948 { 2949 skb_reset_inner_transport_header(skb); 2950 skb->inner_transport_header += offset; 2951 } 2952 2953 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 2954 { 2955 return skb->head + skb->inner_network_header; 2956 } 2957 2958 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 2959 { 2960 skb->inner_network_header = skb->data - skb->head; 2961 } 2962 2963 static inline void skb_set_inner_network_header(struct sk_buff *skb, 2964 const int offset) 2965 { 2966 skb_reset_inner_network_header(skb); 2967 skb->inner_network_header += offset; 2968 } 2969 2970 static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb) 2971 { 2972 return skb->inner_network_header > 0; 2973 } 2974 2975 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 2976 { 2977 return skb->head + skb->inner_mac_header; 2978 } 2979 2980 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 2981 { 2982 skb->inner_mac_header = skb->data - skb->head; 2983 } 2984 2985 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 2986 const int offset) 2987 { 2988 skb_reset_inner_mac_header(skb); 2989 skb->inner_mac_header += offset; 2990 } 2991 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 2992 { 2993 return skb->transport_header != (typeof(skb->transport_header))~0U; 2994 } 2995 2996 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 2997 { 2998 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); 2999 return skb->head + skb->transport_header; 3000 } 3001 3002 static inline void skb_reset_transport_header(struct sk_buff *skb) 3003 { 3004 skb->transport_header = skb->data - skb->head; 3005 } 3006 3007 static inline void skb_set_transport_header(struct sk_buff *skb, 3008 const int offset) 3009 { 3010 skb_reset_transport_header(skb); 3011 skb->transport_header += offset; 3012 } 3013 3014 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 3015 { 3016 return skb->head + skb->network_header; 3017 } 3018 3019 static inline void skb_reset_network_header(struct sk_buff *skb) 3020 { 3021 skb->network_header = skb->data - skb->head; 3022 } 3023 3024 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 3025 { 3026 skb_reset_network_header(skb); 3027 skb->network_header += offset; 3028 } 3029 3030 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 3031 { 3032 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 3033 return skb->head + skb->mac_header; 3034 } 3035 3036 static inline int skb_mac_offset(const struct sk_buff *skb) 3037 { 3038 return skb_mac_header(skb) - skb->data; 3039 } 3040 3041 static inline u32 skb_mac_header_len(const struct sk_buff *skb) 3042 { 3043 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 3044 return skb->network_header - skb->mac_header; 3045 } 3046 3047 static inline void skb_unset_mac_header(struct sk_buff *skb) 3048 { 3049 skb->mac_header = (typeof(skb->mac_header))~0U; 3050 } 3051 3052 static inline void skb_reset_mac_header(struct sk_buff *skb) 3053 { 3054 skb->mac_header = skb->data - skb->head; 3055 } 3056 3057 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 3058 { 3059 skb_reset_mac_header(skb); 3060 skb->mac_header += offset; 3061 } 3062 3063 static inline void skb_pop_mac_header(struct sk_buff *skb) 3064 { 3065 skb->mac_header = skb->network_header; 3066 } 3067 3068 static inline void skb_probe_transport_header(struct sk_buff *skb) 3069 { 3070 struct flow_keys_basic keys; 3071 3072 if (skb_transport_header_was_set(skb)) 3073 return; 3074 3075 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 3076 NULL, 0, 0, 0, 0)) 3077 skb_set_transport_header(skb, keys.control.thoff); 3078 } 3079 3080 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 3081 { 3082 if (skb_mac_header_was_set(skb)) { 3083 const unsigned char *old_mac = skb_mac_header(skb); 3084 3085 skb_set_mac_header(skb, -skb->mac_len); 3086 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 3087 } 3088 } 3089 3090 /* Move the full mac header up to current network_header. 3091 * Leaves skb->data pointing at offset skb->mac_len into the mac_header. 3092 * Must be provided the complete mac header length. 3093 */ 3094 static inline void skb_mac_header_rebuild_full(struct sk_buff *skb, u32 full_mac_len) 3095 { 3096 if (skb_mac_header_was_set(skb)) { 3097 const unsigned char *old_mac = skb_mac_header(skb); 3098 3099 skb_set_mac_header(skb, -full_mac_len); 3100 memmove(skb_mac_header(skb), old_mac, full_mac_len); 3101 __skb_push(skb, full_mac_len - skb->mac_len); 3102 } 3103 } 3104 3105 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 3106 { 3107 return skb->csum_start - skb_headroom(skb); 3108 } 3109 3110 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb) 3111 { 3112 return skb->head + skb->csum_start; 3113 } 3114 3115 static inline int skb_transport_offset(const struct sk_buff *skb) 3116 { 3117 return skb_transport_header(skb) - skb->data; 3118 } 3119 3120 static inline u32 skb_network_header_len(const struct sk_buff *skb) 3121 { 3122 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); 3123 return skb->transport_header - skb->network_header; 3124 } 3125 3126 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 3127 { 3128 return skb->inner_transport_header - skb->inner_network_header; 3129 } 3130 3131 static inline int skb_network_offset(const struct sk_buff *skb) 3132 { 3133 return skb_network_header(skb) - skb->data; 3134 } 3135 3136 static inline int skb_inner_network_offset(const struct sk_buff *skb) 3137 { 3138 return skb_inner_network_header(skb) - skb->data; 3139 } 3140 3141 static inline enum skb_drop_reason 3142 pskb_network_may_pull_reason(struct sk_buff *skb, unsigned int len) 3143 { 3144 return pskb_may_pull_reason(skb, skb_network_offset(skb) + len); 3145 } 3146 3147 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 3148 { 3149 return pskb_network_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET; 3150 } 3151 3152 /* 3153 * CPUs often take a performance hit when accessing unaligned memory 3154 * locations. The actual performance hit varies, it can be small if the 3155 * hardware handles it or large if we have to take an exception and fix it 3156 * in software. 3157 * 3158 * Since an ethernet header is 14 bytes network drivers often end up with 3159 * the IP header at an unaligned offset. The IP header can be aligned by 3160 * shifting the start of the packet by 2 bytes. Drivers should do this 3161 * with: 3162 * 3163 * skb_reserve(skb, NET_IP_ALIGN); 3164 * 3165 * The downside to this alignment of the IP header is that the DMA is now 3166 * unaligned. On some architectures the cost of an unaligned DMA is high 3167 * and this cost outweighs the gains made by aligning the IP header. 3168 * 3169 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 3170 * to be overridden. 3171 */ 3172 #ifndef NET_IP_ALIGN 3173 #define NET_IP_ALIGN 2 3174 #endif 3175 3176 /* 3177 * The networking layer reserves some headroom in skb data (via 3178 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 3179 * the header has to grow. In the default case, if the header has to grow 3180 * 32 bytes or less we avoid the reallocation. 3181 * 3182 * Unfortunately this headroom changes the DMA alignment of the resulting 3183 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 3184 * on some architectures. An architecture can override this value, 3185 * perhaps setting it to a cacheline in size (since that will maintain 3186 * cacheline alignment of the DMA). It must be a power of 2. 3187 * 3188 * Various parts of the networking layer expect at least 32 bytes of 3189 * headroom, you should not reduce this. 3190 * 3191 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 3192 * to reduce average number of cache lines per packet. 3193 * get_rps_cpu() for example only access one 64 bytes aligned block : 3194 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 3195 */ 3196 #ifndef NET_SKB_PAD 3197 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 3198 #endif 3199 3200 int ___pskb_trim(struct sk_buff *skb, unsigned int len); 3201 3202 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len) 3203 { 3204 if (WARN_ON(skb_is_nonlinear(skb))) 3205 return; 3206 skb->len = len; 3207 skb_set_tail_pointer(skb, len); 3208 } 3209 3210 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 3211 { 3212 __skb_set_length(skb, len); 3213 } 3214 3215 void skb_trim(struct sk_buff *skb, unsigned int len); 3216 3217 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 3218 { 3219 if (skb->data_len) 3220 return ___pskb_trim(skb, len); 3221 __skb_trim(skb, len); 3222 return 0; 3223 } 3224 3225 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 3226 { 3227 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 3228 } 3229 3230 /** 3231 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 3232 * @skb: buffer to alter 3233 * @len: new length 3234 * 3235 * This is identical to pskb_trim except that the caller knows that 3236 * the skb is not cloned so we should never get an error due to out- 3237 * of-memory. 3238 */ 3239 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 3240 { 3241 int err = pskb_trim(skb, len); 3242 BUG_ON(err); 3243 } 3244 3245 static inline int __skb_grow(struct sk_buff *skb, unsigned int len) 3246 { 3247 unsigned int diff = len - skb->len; 3248 3249 if (skb_tailroom(skb) < diff) { 3250 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb), 3251 GFP_ATOMIC); 3252 if (ret) 3253 return ret; 3254 } 3255 __skb_set_length(skb, len); 3256 return 0; 3257 } 3258 3259 /** 3260 * skb_orphan - orphan a buffer 3261 * @skb: buffer to orphan 3262 * 3263 * If a buffer currently has an owner then we call the owner's 3264 * destructor function and make the @skb unowned. The buffer continues 3265 * to exist but is no longer charged to its former owner. 3266 */ 3267 static inline void skb_orphan(struct sk_buff *skb) 3268 { 3269 if (skb->destructor) { 3270 skb->destructor(skb); 3271 skb->destructor = NULL; 3272 skb->sk = NULL; 3273 } else { 3274 BUG_ON(skb->sk); 3275 } 3276 } 3277 3278 /** 3279 * skb_orphan_frags - orphan the frags contained in a buffer 3280 * @skb: buffer to orphan frags from 3281 * @gfp_mask: allocation mask for replacement pages 3282 * 3283 * For each frag in the SKB which needs a destructor (i.e. has an 3284 * owner) create a copy of that frag and release the original 3285 * page by calling the destructor. 3286 */ 3287 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 3288 { 3289 if (likely(!skb_zcopy(skb))) 3290 return 0; 3291 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN) 3292 return 0; 3293 return skb_copy_ubufs(skb, gfp_mask); 3294 } 3295 3296 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */ 3297 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask) 3298 { 3299 if (likely(!skb_zcopy(skb))) 3300 return 0; 3301 return skb_copy_ubufs(skb, gfp_mask); 3302 } 3303 3304 /** 3305 * __skb_queue_purge_reason - empty a list 3306 * @list: list to empty 3307 * @reason: drop reason 3308 * 3309 * Delete all buffers on an &sk_buff list. Each buffer is removed from 3310 * the list and one reference dropped. This function does not take the 3311 * list lock and the caller must hold the relevant locks to use it. 3312 */ 3313 static inline void __skb_queue_purge_reason(struct sk_buff_head *list, 3314 enum skb_drop_reason reason) 3315 { 3316 struct sk_buff *skb; 3317 3318 while ((skb = __skb_dequeue(list)) != NULL) 3319 kfree_skb_reason(skb, reason); 3320 } 3321 3322 static inline void __skb_queue_purge(struct sk_buff_head *list) 3323 { 3324 __skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE); 3325 } 3326 3327 void skb_queue_purge_reason(struct sk_buff_head *list, 3328 enum skb_drop_reason reason); 3329 3330 static inline void skb_queue_purge(struct sk_buff_head *list) 3331 { 3332 skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE); 3333 } 3334 3335 unsigned int skb_rbtree_purge(struct rb_root *root); 3336 void skb_errqueue_purge(struct sk_buff_head *list); 3337 3338 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3339 3340 /** 3341 * netdev_alloc_frag - allocate a page fragment 3342 * @fragsz: fragment size 3343 * 3344 * Allocates a frag from a page for receive buffer. 3345 * Uses GFP_ATOMIC allocations. 3346 */ 3347 static inline void *netdev_alloc_frag(unsigned int fragsz) 3348 { 3349 return __netdev_alloc_frag_align(fragsz, ~0u); 3350 } 3351 3352 static inline void *netdev_alloc_frag_align(unsigned int fragsz, 3353 unsigned int align) 3354 { 3355 WARN_ON_ONCE(!is_power_of_2(align)); 3356 return __netdev_alloc_frag_align(fragsz, -align); 3357 } 3358 3359 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 3360 gfp_t gfp_mask); 3361 3362 /** 3363 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 3364 * @dev: network device to receive on 3365 * @length: length to allocate 3366 * 3367 * Allocate a new &sk_buff and assign it a usage count of one. The 3368 * buffer has unspecified headroom built in. Users should allocate 3369 * the headroom they think they need without accounting for the 3370 * built in space. The built in space is used for optimisations. 3371 * 3372 * %NULL is returned if there is no free memory. Although this function 3373 * allocates memory it can be called from an interrupt. 3374 */ 3375 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 3376 unsigned int length) 3377 { 3378 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 3379 } 3380 3381 /* legacy helper around __netdev_alloc_skb() */ 3382 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 3383 gfp_t gfp_mask) 3384 { 3385 return __netdev_alloc_skb(NULL, length, gfp_mask); 3386 } 3387 3388 /* legacy helper around netdev_alloc_skb() */ 3389 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 3390 { 3391 return netdev_alloc_skb(NULL, length); 3392 } 3393 3394 3395 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 3396 unsigned int length, gfp_t gfp) 3397 { 3398 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 3399 3400 if (NET_IP_ALIGN && skb) 3401 skb_reserve(skb, NET_IP_ALIGN); 3402 return skb; 3403 } 3404 3405 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 3406 unsigned int length) 3407 { 3408 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 3409 } 3410 3411 static inline void skb_free_frag(void *addr) 3412 { 3413 page_frag_free(addr); 3414 } 3415 3416 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3417 3418 static inline void *napi_alloc_frag(unsigned int fragsz) 3419 { 3420 return __napi_alloc_frag_align(fragsz, ~0u); 3421 } 3422 3423 static inline void *napi_alloc_frag_align(unsigned int fragsz, 3424 unsigned int align) 3425 { 3426 WARN_ON_ONCE(!is_power_of_2(align)); 3427 return __napi_alloc_frag_align(fragsz, -align); 3428 } 3429 3430 struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int length); 3431 void napi_consume_skb(struct sk_buff *skb, int budget); 3432 3433 void napi_skb_free_stolen_head(struct sk_buff *skb); 3434 void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason); 3435 3436 /** 3437 * __dev_alloc_pages - allocate page for network Rx 3438 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3439 * @order: size of the allocation 3440 * 3441 * Allocate a new page. 3442 * 3443 * %NULL is returned if there is no free memory. 3444 */ 3445 static inline struct page *__dev_alloc_pages_noprof(gfp_t gfp_mask, 3446 unsigned int order) 3447 { 3448 /* This piece of code contains several assumptions. 3449 * 1. This is for device Rx, therefore a cold page is preferred. 3450 * 2. The expectation is the user wants a compound page. 3451 * 3. If requesting a order 0 page it will not be compound 3452 * due to the check to see if order has a value in prep_new_page 3453 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to 3454 * code in gfp_to_alloc_flags that should be enforcing this. 3455 */ 3456 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC; 3457 3458 return alloc_pages_node_noprof(NUMA_NO_NODE, gfp_mask, order); 3459 } 3460 #define __dev_alloc_pages(...) alloc_hooks(__dev_alloc_pages_noprof(__VA_ARGS__)) 3461 3462 /* 3463 * This specialized allocator has to be a macro for its allocations to be 3464 * accounted separately (to have a separate alloc_tag). 3465 */ 3466 #define dev_alloc_pages(_order) __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, _order) 3467 3468 /** 3469 * __dev_alloc_page - allocate a page for network Rx 3470 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3471 * 3472 * Allocate a new page. 3473 * 3474 * %NULL is returned if there is no free memory. 3475 */ 3476 static inline struct page *__dev_alloc_page_noprof(gfp_t gfp_mask) 3477 { 3478 return __dev_alloc_pages_noprof(gfp_mask, 0); 3479 } 3480 #define __dev_alloc_page(...) alloc_hooks(__dev_alloc_page_noprof(__VA_ARGS__)) 3481 3482 /* 3483 * This specialized allocator has to be a macro for its allocations to be 3484 * accounted separately (to have a separate alloc_tag). 3485 */ 3486 #define dev_alloc_page() dev_alloc_pages(0) 3487 3488 /** 3489 * dev_page_is_reusable - check whether a page can be reused for network Rx 3490 * @page: the page to test 3491 * 3492 * A page shouldn't be considered for reusing/recycling if it was allocated 3493 * under memory pressure or at a distant memory node. 3494 * 3495 * Returns false if this page should be returned to page allocator, true 3496 * otherwise. 3497 */ 3498 static inline bool dev_page_is_reusable(const struct page *page) 3499 { 3500 return likely(page_to_nid(page) == numa_mem_id() && 3501 !page_is_pfmemalloc(page)); 3502 } 3503 3504 /** 3505 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 3506 * @page: The page that was allocated from skb_alloc_page 3507 * @skb: The skb that may need pfmemalloc set 3508 */ 3509 static inline void skb_propagate_pfmemalloc(const struct page *page, 3510 struct sk_buff *skb) 3511 { 3512 if (page_is_pfmemalloc(page)) 3513 skb->pfmemalloc = true; 3514 } 3515 3516 /** 3517 * skb_frag_off() - Returns the offset of a skb fragment 3518 * @frag: the paged fragment 3519 */ 3520 static inline unsigned int skb_frag_off(const skb_frag_t *frag) 3521 { 3522 return frag->offset; 3523 } 3524 3525 /** 3526 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta 3527 * @frag: skb fragment 3528 * @delta: value to add 3529 */ 3530 static inline void skb_frag_off_add(skb_frag_t *frag, int delta) 3531 { 3532 frag->offset += delta; 3533 } 3534 3535 /** 3536 * skb_frag_off_set() - Sets the offset of a skb fragment 3537 * @frag: skb fragment 3538 * @offset: offset of fragment 3539 */ 3540 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset) 3541 { 3542 frag->offset = offset; 3543 } 3544 3545 /** 3546 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment 3547 * @fragto: skb fragment where offset is set 3548 * @fragfrom: skb fragment offset is copied from 3549 */ 3550 static inline void skb_frag_off_copy(skb_frag_t *fragto, 3551 const skb_frag_t *fragfrom) 3552 { 3553 fragto->offset = fragfrom->offset; 3554 } 3555 3556 /* Return: true if the skb_frag contains a net_iov. */ 3557 static inline bool skb_frag_is_net_iov(const skb_frag_t *frag) 3558 { 3559 return netmem_is_net_iov(frag->netmem); 3560 } 3561 3562 /** 3563 * skb_frag_net_iov - retrieve the net_iov referred to by fragment 3564 * @frag: the fragment 3565 * 3566 * Return: the &struct net_iov associated with @frag. Returns NULL if this 3567 * frag has no associated net_iov. 3568 */ 3569 static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag) 3570 { 3571 if (!skb_frag_is_net_iov(frag)) 3572 return NULL; 3573 3574 return netmem_to_net_iov(frag->netmem); 3575 } 3576 3577 /** 3578 * skb_frag_page - retrieve the page referred to by a paged fragment 3579 * @frag: the paged fragment 3580 * 3581 * Return: the &struct page associated with @frag. Returns NULL if this frag 3582 * has no associated page. 3583 */ 3584 static inline struct page *skb_frag_page(const skb_frag_t *frag) 3585 { 3586 if (skb_frag_is_net_iov(frag)) 3587 return NULL; 3588 3589 return netmem_to_page(frag->netmem); 3590 } 3591 3592 /** 3593 * skb_frag_netmem - retrieve the netmem referred to by a fragment 3594 * @frag: the fragment 3595 * 3596 * Return: the &netmem_ref associated with @frag. 3597 */ 3598 static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag) 3599 { 3600 return frag->netmem; 3601 } 3602 3603 int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, 3604 unsigned int headroom); 3605 int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, 3606 struct bpf_prog *prog); 3607 3608 /** 3609 * skb_frag_address - gets the address of the data contained in a paged fragment 3610 * @frag: the paged fragment buffer 3611 * 3612 * Returns the address of the data within @frag. The page must already 3613 * be mapped. 3614 */ 3615 static inline void *skb_frag_address(const skb_frag_t *frag) 3616 { 3617 if (!skb_frag_page(frag)) 3618 return NULL; 3619 3620 return page_address(skb_frag_page(frag)) + skb_frag_off(frag); 3621 } 3622 3623 /** 3624 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 3625 * @frag: the paged fragment buffer 3626 * 3627 * Returns the address of the data within @frag. Checks that the page 3628 * is mapped and returns %NULL otherwise. 3629 */ 3630 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 3631 { 3632 void *ptr = page_address(skb_frag_page(frag)); 3633 if (unlikely(!ptr)) 3634 return NULL; 3635 3636 return ptr + skb_frag_off(frag); 3637 } 3638 3639 /** 3640 * skb_frag_page_copy() - sets the page in a fragment from another fragment 3641 * @fragto: skb fragment where page is set 3642 * @fragfrom: skb fragment page is copied from 3643 */ 3644 static inline void skb_frag_page_copy(skb_frag_t *fragto, 3645 const skb_frag_t *fragfrom) 3646 { 3647 fragto->netmem = fragfrom->netmem; 3648 } 3649 3650 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 3651 3652 /** 3653 * skb_frag_dma_map - maps a paged fragment via the DMA API 3654 * @dev: the device to map the fragment to 3655 * @frag: the paged fragment to map 3656 * @offset: the offset within the fragment (starting at the 3657 * fragment's own offset) 3658 * @size: the number of bytes to map 3659 * @dir: the direction of the mapping (``PCI_DMA_*``) 3660 * 3661 * Maps the page associated with @frag to @device. 3662 */ 3663 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 3664 const skb_frag_t *frag, 3665 size_t offset, size_t size, 3666 enum dma_data_direction dir) 3667 { 3668 return dma_map_page(dev, skb_frag_page(frag), 3669 skb_frag_off(frag) + offset, size, dir); 3670 } 3671 3672 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 3673 gfp_t gfp_mask) 3674 { 3675 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 3676 } 3677 3678 3679 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb, 3680 gfp_t gfp_mask) 3681 { 3682 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true); 3683 } 3684 3685 3686 /** 3687 * skb_clone_writable - is the header of a clone writable 3688 * @skb: buffer to check 3689 * @len: length up to which to write 3690 * 3691 * Returns true if modifying the header part of the cloned buffer 3692 * does not requires the data to be copied. 3693 */ 3694 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 3695 { 3696 return !skb_header_cloned(skb) && 3697 skb_headroom(skb) + len <= skb->hdr_len; 3698 } 3699 3700 static inline int skb_try_make_writable(struct sk_buff *skb, 3701 unsigned int write_len) 3702 { 3703 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) && 3704 pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 3705 } 3706 3707 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 3708 int cloned) 3709 { 3710 int delta = 0; 3711 3712 if (headroom > skb_headroom(skb)) 3713 delta = headroom - skb_headroom(skb); 3714 3715 if (delta || cloned) 3716 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 3717 GFP_ATOMIC); 3718 return 0; 3719 } 3720 3721 /** 3722 * skb_cow - copy header of skb when it is required 3723 * @skb: buffer to cow 3724 * @headroom: needed headroom 3725 * 3726 * If the skb passed lacks sufficient headroom or its data part 3727 * is shared, data is reallocated. If reallocation fails, an error 3728 * is returned and original skb is not changed. 3729 * 3730 * The result is skb with writable area skb->head...skb->tail 3731 * and at least @headroom of space at head. 3732 */ 3733 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 3734 { 3735 return __skb_cow(skb, headroom, skb_cloned(skb)); 3736 } 3737 3738 /** 3739 * skb_cow_head - skb_cow but only making the head writable 3740 * @skb: buffer to cow 3741 * @headroom: needed headroom 3742 * 3743 * This function is identical to skb_cow except that we replace the 3744 * skb_cloned check by skb_header_cloned. It should be used when 3745 * you only need to push on some header and do not need to modify 3746 * the data. 3747 */ 3748 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 3749 { 3750 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 3751 } 3752 3753 /** 3754 * skb_padto - pad an skbuff up to a minimal size 3755 * @skb: buffer to pad 3756 * @len: minimal length 3757 * 3758 * Pads up a buffer to ensure the trailing bytes exist and are 3759 * blanked. If the buffer already contains sufficient data it 3760 * is untouched. Otherwise it is extended. Returns zero on 3761 * success. The skb is freed on error. 3762 */ 3763 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 3764 { 3765 unsigned int size = skb->len; 3766 if (likely(size >= len)) 3767 return 0; 3768 return skb_pad(skb, len - size); 3769 } 3770 3771 /** 3772 * __skb_put_padto - increase size and pad an skbuff up to a minimal size 3773 * @skb: buffer to pad 3774 * @len: minimal length 3775 * @free_on_error: free buffer on error 3776 * 3777 * Pads up a buffer to ensure the trailing bytes exist and are 3778 * blanked. If the buffer already contains sufficient data it 3779 * is untouched. Otherwise it is extended. Returns zero on 3780 * success. The skb is freed on error if @free_on_error is true. 3781 */ 3782 static inline int __must_check __skb_put_padto(struct sk_buff *skb, 3783 unsigned int len, 3784 bool free_on_error) 3785 { 3786 unsigned int size = skb->len; 3787 3788 if (unlikely(size < len)) { 3789 len -= size; 3790 if (__skb_pad(skb, len, free_on_error)) 3791 return -ENOMEM; 3792 __skb_put(skb, len); 3793 } 3794 return 0; 3795 } 3796 3797 /** 3798 * skb_put_padto - increase size and pad an skbuff up to a minimal size 3799 * @skb: buffer to pad 3800 * @len: minimal length 3801 * 3802 * Pads up a buffer to ensure the trailing bytes exist and are 3803 * blanked. If the buffer already contains sufficient data it 3804 * is untouched. Otherwise it is extended. Returns zero on 3805 * success. The skb is freed on error. 3806 */ 3807 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len) 3808 { 3809 return __skb_put_padto(skb, len, true); 3810 } 3811 3812 bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i) 3813 __must_check; 3814 3815 static inline int skb_add_data(struct sk_buff *skb, 3816 struct iov_iter *from, int copy) 3817 { 3818 const int off = skb->len; 3819 3820 if (skb->ip_summed == CHECKSUM_NONE) { 3821 __wsum csum = 0; 3822 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy, 3823 &csum, from)) { 3824 skb->csum = csum_block_add(skb->csum, csum, off); 3825 return 0; 3826 } 3827 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from)) 3828 return 0; 3829 3830 __skb_trim(skb, off); 3831 return -EFAULT; 3832 } 3833 3834 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 3835 const struct page *page, int off) 3836 { 3837 if (skb_zcopy(skb)) 3838 return false; 3839 if (i) { 3840 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1]; 3841 3842 return page == skb_frag_page(frag) && 3843 off == skb_frag_off(frag) + skb_frag_size(frag); 3844 } 3845 return false; 3846 } 3847 3848 static inline int __skb_linearize(struct sk_buff *skb) 3849 { 3850 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 3851 } 3852 3853 /** 3854 * skb_linearize - convert paged skb to linear one 3855 * @skb: buffer to linarize 3856 * 3857 * If there is no free memory -ENOMEM is returned, otherwise zero 3858 * is returned and the old skb data released. 3859 */ 3860 static inline int skb_linearize(struct sk_buff *skb) 3861 { 3862 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 3863 } 3864 3865 /** 3866 * skb_has_shared_frag - can any frag be overwritten 3867 * @skb: buffer to test 3868 * 3869 * Return true if the skb has at least one frag that might be modified 3870 * by an external entity (as in vmsplice()/sendfile()) 3871 */ 3872 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 3873 { 3874 return skb_is_nonlinear(skb) && 3875 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; 3876 } 3877 3878 /** 3879 * skb_linearize_cow - make sure skb is linear and writable 3880 * @skb: buffer to process 3881 * 3882 * If there is no free memory -ENOMEM is returned, otherwise zero 3883 * is returned and the old skb data released. 3884 */ 3885 static inline int skb_linearize_cow(struct sk_buff *skb) 3886 { 3887 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 3888 __skb_linearize(skb) : 0; 3889 } 3890 3891 static __always_inline void 3892 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3893 unsigned int off) 3894 { 3895 if (skb->ip_summed == CHECKSUM_COMPLETE) 3896 skb->csum = csum_block_sub(skb->csum, 3897 csum_partial(start, len, 0), off); 3898 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3899 skb_checksum_start_offset(skb) < 0) 3900 skb->ip_summed = CHECKSUM_NONE; 3901 } 3902 3903 /** 3904 * skb_postpull_rcsum - update checksum for received skb after pull 3905 * @skb: buffer to update 3906 * @start: start of data before pull 3907 * @len: length of data pulled 3908 * 3909 * After doing a pull on a received packet, you need to call this to 3910 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 3911 * CHECKSUM_NONE so that it can be recomputed from scratch. 3912 */ 3913 static inline void skb_postpull_rcsum(struct sk_buff *skb, 3914 const void *start, unsigned int len) 3915 { 3916 if (skb->ip_summed == CHECKSUM_COMPLETE) 3917 skb->csum = wsum_negate(csum_partial(start, len, 3918 wsum_negate(skb->csum))); 3919 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3920 skb_checksum_start_offset(skb) < 0) 3921 skb->ip_summed = CHECKSUM_NONE; 3922 } 3923 3924 static __always_inline void 3925 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3926 unsigned int off) 3927 { 3928 if (skb->ip_summed == CHECKSUM_COMPLETE) 3929 skb->csum = csum_block_add(skb->csum, 3930 csum_partial(start, len, 0), off); 3931 } 3932 3933 /** 3934 * skb_postpush_rcsum - update checksum for received skb after push 3935 * @skb: buffer to update 3936 * @start: start of data after push 3937 * @len: length of data pushed 3938 * 3939 * After doing a push on a received packet, you need to call this to 3940 * update the CHECKSUM_COMPLETE checksum. 3941 */ 3942 static inline void skb_postpush_rcsum(struct sk_buff *skb, 3943 const void *start, unsigned int len) 3944 { 3945 __skb_postpush_rcsum(skb, start, len, 0); 3946 } 3947 3948 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 3949 3950 /** 3951 * skb_push_rcsum - push skb and update receive checksum 3952 * @skb: buffer to update 3953 * @len: length of data pulled 3954 * 3955 * This function performs an skb_push on the packet and updates 3956 * the CHECKSUM_COMPLETE checksum. It should be used on 3957 * receive path processing instead of skb_push unless you know 3958 * that the checksum difference is zero (e.g., a valid IP header) 3959 * or you are setting ip_summed to CHECKSUM_NONE. 3960 */ 3961 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len) 3962 { 3963 skb_push(skb, len); 3964 skb_postpush_rcsum(skb, skb->data, len); 3965 return skb->data; 3966 } 3967 3968 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len); 3969 /** 3970 * pskb_trim_rcsum - trim received skb and update checksum 3971 * @skb: buffer to trim 3972 * @len: new length 3973 * 3974 * This is exactly the same as pskb_trim except that it ensures the 3975 * checksum of received packets are still valid after the operation. 3976 * It can change skb pointers. 3977 */ 3978 3979 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3980 { 3981 if (likely(len >= skb->len)) 3982 return 0; 3983 return pskb_trim_rcsum_slow(skb, len); 3984 } 3985 3986 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3987 { 3988 if (skb->ip_summed == CHECKSUM_COMPLETE) 3989 skb->ip_summed = CHECKSUM_NONE; 3990 __skb_trim(skb, len); 3991 return 0; 3992 } 3993 3994 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len) 3995 { 3996 if (skb->ip_summed == CHECKSUM_COMPLETE) 3997 skb->ip_summed = CHECKSUM_NONE; 3998 return __skb_grow(skb, len); 3999 } 4000 4001 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode) 4002 #define skb_rb_first(root) rb_to_skb(rb_first(root)) 4003 #define skb_rb_last(root) rb_to_skb(rb_last(root)) 4004 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode)) 4005 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode)) 4006 4007 #define skb_queue_walk(queue, skb) \ 4008 for (skb = (queue)->next; \ 4009 skb != (struct sk_buff *)(queue); \ 4010 skb = skb->next) 4011 4012 #define skb_queue_walk_safe(queue, skb, tmp) \ 4013 for (skb = (queue)->next, tmp = skb->next; \ 4014 skb != (struct sk_buff *)(queue); \ 4015 skb = tmp, tmp = skb->next) 4016 4017 #define skb_queue_walk_from(queue, skb) \ 4018 for (; skb != (struct sk_buff *)(queue); \ 4019 skb = skb->next) 4020 4021 #define skb_rbtree_walk(skb, root) \ 4022 for (skb = skb_rb_first(root); skb != NULL; \ 4023 skb = skb_rb_next(skb)) 4024 4025 #define skb_rbtree_walk_from(skb) \ 4026 for (; skb != NULL; \ 4027 skb = skb_rb_next(skb)) 4028 4029 #define skb_rbtree_walk_from_safe(skb, tmp) \ 4030 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \ 4031 skb = tmp) 4032 4033 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 4034 for (tmp = skb->next; \ 4035 skb != (struct sk_buff *)(queue); \ 4036 skb = tmp, tmp = skb->next) 4037 4038 #define skb_queue_reverse_walk(queue, skb) \ 4039 for (skb = (queue)->prev; \ 4040 skb != (struct sk_buff *)(queue); \ 4041 skb = skb->prev) 4042 4043 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 4044 for (skb = (queue)->prev, tmp = skb->prev; \ 4045 skb != (struct sk_buff *)(queue); \ 4046 skb = tmp, tmp = skb->prev) 4047 4048 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 4049 for (tmp = skb->prev; \ 4050 skb != (struct sk_buff *)(queue); \ 4051 skb = tmp, tmp = skb->prev) 4052 4053 static inline bool skb_has_frag_list(const struct sk_buff *skb) 4054 { 4055 return skb_shinfo(skb)->frag_list != NULL; 4056 } 4057 4058 static inline void skb_frag_list_init(struct sk_buff *skb) 4059 { 4060 skb_shinfo(skb)->frag_list = NULL; 4061 } 4062 4063 #define skb_walk_frags(skb, iter) \ 4064 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 4065 4066 4067 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue, 4068 int *err, long *timeo_p, 4069 const struct sk_buff *skb); 4070 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 4071 struct sk_buff_head *queue, 4072 unsigned int flags, 4073 int *off, int *err, 4074 struct sk_buff **last); 4075 struct sk_buff *__skb_try_recv_datagram(struct sock *sk, 4076 struct sk_buff_head *queue, 4077 unsigned int flags, int *off, int *err, 4078 struct sk_buff **last); 4079 struct sk_buff *__skb_recv_datagram(struct sock *sk, 4080 struct sk_buff_head *sk_queue, 4081 unsigned int flags, int *off, int *err); 4082 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err); 4083 __poll_t datagram_poll(struct file *file, struct socket *sock, 4084 struct poll_table_struct *wait); 4085 int skb_copy_datagram_iter(const struct sk_buff *from, int offset, 4086 struct iov_iter *to, int size); 4087 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 4088 struct msghdr *msg, int size) 4089 { 4090 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size); 4091 } 4092 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 4093 struct msghdr *msg); 4094 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, 4095 struct iov_iter *to, int len, 4096 struct ahash_request *hash); 4097 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, 4098 struct iov_iter *from, int len); 4099 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 4100 void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 4101 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 4102 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 4103 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 4104 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 4105 int len); 4106 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, 4107 struct pipe_inode_info *pipe, unsigned int len, 4108 unsigned int flags); 4109 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, 4110 int len); 4111 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len); 4112 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 4113 unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 4114 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, 4115 int len, int hlen); 4116 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 4117 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 4118 void skb_scrub_packet(struct sk_buff *skb, bool xnet); 4119 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 4120 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features, 4121 unsigned int offset); 4122 struct sk_buff *skb_vlan_untag(struct sk_buff *skb); 4123 int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len); 4124 int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev); 4125 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); 4126 int skb_vlan_pop(struct sk_buff *skb); 4127 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); 4128 int skb_eth_pop(struct sk_buff *skb); 4129 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst, 4130 const unsigned char *src); 4131 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, 4132 int mac_len, bool ethernet); 4133 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, 4134 bool ethernet); 4135 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse); 4136 int skb_mpls_dec_ttl(struct sk_buff *skb); 4137 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy, 4138 gfp_t gfp); 4139 4140 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len) 4141 { 4142 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT; 4143 } 4144 4145 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len) 4146 { 4147 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 4148 } 4149 4150 struct skb_checksum_ops { 4151 __wsum (*update)(const void *mem, int len, __wsum wsum); 4152 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 4153 }; 4154 4155 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly; 4156 4157 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 4158 __wsum csum, const struct skb_checksum_ops *ops); 4159 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 4160 __wsum csum); 4161 4162 static inline void * __must_check 4163 __skb_header_pointer(const struct sk_buff *skb, int offset, int len, 4164 const void *data, int hlen, void *buffer) 4165 { 4166 if (likely(hlen - offset >= len)) 4167 return (void *)data + offset; 4168 4169 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0)) 4170 return NULL; 4171 4172 return buffer; 4173 } 4174 4175 static inline void * __must_check 4176 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) 4177 { 4178 return __skb_header_pointer(skb, offset, len, skb->data, 4179 skb_headlen(skb), buffer); 4180 } 4181 4182 static inline void * __must_check 4183 skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len) 4184 { 4185 if (likely(skb_headlen(skb) - offset >= len)) 4186 return skb->data + offset; 4187 return NULL; 4188 } 4189 4190 /** 4191 * skb_needs_linearize - check if we need to linearize a given skb 4192 * depending on the given device features. 4193 * @skb: socket buffer to check 4194 * @features: net device features 4195 * 4196 * Returns true if either: 4197 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 4198 * 2. skb is fragmented and the device does not support SG. 4199 */ 4200 static inline bool skb_needs_linearize(struct sk_buff *skb, 4201 netdev_features_t features) 4202 { 4203 return skb_is_nonlinear(skb) && 4204 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 4205 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 4206 } 4207 4208 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 4209 void *to, 4210 const unsigned int len) 4211 { 4212 memcpy(to, skb->data, len); 4213 } 4214 4215 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 4216 const int offset, void *to, 4217 const unsigned int len) 4218 { 4219 memcpy(to, skb->data + offset, len); 4220 } 4221 4222 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 4223 const void *from, 4224 const unsigned int len) 4225 { 4226 memcpy(skb->data, from, len); 4227 } 4228 4229 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 4230 const int offset, 4231 const void *from, 4232 const unsigned int len) 4233 { 4234 memcpy(skb->data + offset, from, len); 4235 } 4236 4237 void skb_init(void); 4238 4239 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 4240 { 4241 return skb->tstamp; 4242 } 4243 4244 /** 4245 * skb_get_timestamp - get timestamp from a skb 4246 * @skb: skb to get stamp from 4247 * @stamp: pointer to struct __kernel_old_timeval to store stamp in 4248 * 4249 * Timestamps are stored in the skb as offsets to a base timestamp. 4250 * This function converts the offset back to a struct timeval and stores 4251 * it in stamp. 4252 */ 4253 static inline void skb_get_timestamp(const struct sk_buff *skb, 4254 struct __kernel_old_timeval *stamp) 4255 { 4256 *stamp = ns_to_kernel_old_timeval(skb->tstamp); 4257 } 4258 4259 static inline void skb_get_new_timestamp(const struct sk_buff *skb, 4260 struct __kernel_sock_timeval *stamp) 4261 { 4262 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4263 4264 stamp->tv_sec = ts.tv_sec; 4265 stamp->tv_usec = ts.tv_nsec / 1000; 4266 } 4267 4268 static inline void skb_get_timestampns(const struct sk_buff *skb, 4269 struct __kernel_old_timespec *stamp) 4270 { 4271 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4272 4273 stamp->tv_sec = ts.tv_sec; 4274 stamp->tv_nsec = ts.tv_nsec; 4275 } 4276 4277 static inline void skb_get_new_timestampns(const struct sk_buff *skb, 4278 struct __kernel_timespec *stamp) 4279 { 4280 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4281 4282 stamp->tv_sec = ts.tv_sec; 4283 stamp->tv_nsec = ts.tv_nsec; 4284 } 4285 4286 static inline void __net_timestamp(struct sk_buff *skb) 4287 { 4288 skb->tstamp = ktime_get_real(); 4289 skb->tstamp_type = SKB_CLOCK_REALTIME; 4290 } 4291 4292 static inline ktime_t net_timedelta(ktime_t t) 4293 { 4294 return ktime_sub(ktime_get_real(), t); 4295 } 4296 4297 static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt, 4298 u8 tstamp_type) 4299 { 4300 skb->tstamp = kt; 4301 4302 if (kt) 4303 skb->tstamp_type = tstamp_type; 4304 else 4305 skb->tstamp_type = SKB_CLOCK_REALTIME; 4306 } 4307 4308 static inline void skb_set_delivery_type_by_clockid(struct sk_buff *skb, 4309 ktime_t kt, clockid_t clockid) 4310 { 4311 u8 tstamp_type = SKB_CLOCK_REALTIME; 4312 4313 switch (clockid) { 4314 case CLOCK_REALTIME: 4315 break; 4316 case CLOCK_MONOTONIC: 4317 tstamp_type = SKB_CLOCK_MONOTONIC; 4318 break; 4319 case CLOCK_TAI: 4320 tstamp_type = SKB_CLOCK_TAI; 4321 break; 4322 default: 4323 WARN_ON_ONCE(1); 4324 kt = 0; 4325 } 4326 4327 skb_set_delivery_time(skb, kt, tstamp_type); 4328 } 4329 4330 DECLARE_STATIC_KEY_FALSE(netstamp_needed_key); 4331 4332 /* It is used in the ingress path to clear the delivery_time. 4333 * If needed, set the skb->tstamp to the (rcv) timestamp. 4334 */ 4335 static inline void skb_clear_delivery_time(struct sk_buff *skb) 4336 { 4337 if (skb->tstamp_type) { 4338 skb->tstamp_type = SKB_CLOCK_REALTIME; 4339 if (static_branch_unlikely(&netstamp_needed_key)) 4340 skb->tstamp = ktime_get_real(); 4341 else 4342 skb->tstamp = 0; 4343 } 4344 } 4345 4346 static inline void skb_clear_tstamp(struct sk_buff *skb) 4347 { 4348 if (skb->tstamp_type) 4349 return; 4350 4351 skb->tstamp = 0; 4352 } 4353 4354 static inline ktime_t skb_tstamp(const struct sk_buff *skb) 4355 { 4356 if (skb->tstamp_type) 4357 return 0; 4358 4359 return skb->tstamp; 4360 } 4361 4362 static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond) 4363 { 4364 if (skb->tstamp_type != SKB_CLOCK_MONOTONIC && skb->tstamp) 4365 return skb->tstamp; 4366 4367 if (static_branch_unlikely(&netstamp_needed_key) || cond) 4368 return ktime_get_real(); 4369 4370 return 0; 4371 } 4372 4373 static inline u8 skb_metadata_len(const struct sk_buff *skb) 4374 { 4375 return skb_shinfo(skb)->meta_len; 4376 } 4377 4378 static inline void *skb_metadata_end(const struct sk_buff *skb) 4379 { 4380 return skb_mac_header(skb); 4381 } 4382 4383 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, 4384 const struct sk_buff *skb_b, 4385 u8 meta_len) 4386 { 4387 const void *a = skb_metadata_end(skb_a); 4388 const void *b = skb_metadata_end(skb_b); 4389 u64 diffs = 0; 4390 4391 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || 4392 BITS_PER_LONG != 64) 4393 goto slow; 4394 4395 /* Using more efficient variant than plain call to memcmp(). */ 4396 switch (meta_len) { 4397 #define __it(x, op) (x -= sizeof(u##op)) 4398 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op)) 4399 case 32: diffs |= __it_diff(a, b, 64); 4400 fallthrough; 4401 case 24: diffs |= __it_diff(a, b, 64); 4402 fallthrough; 4403 case 16: diffs |= __it_diff(a, b, 64); 4404 fallthrough; 4405 case 8: diffs |= __it_diff(a, b, 64); 4406 break; 4407 case 28: diffs |= __it_diff(a, b, 64); 4408 fallthrough; 4409 case 20: diffs |= __it_diff(a, b, 64); 4410 fallthrough; 4411 case 12: diffs |= __it_diff(a, b, 64); 4412 fallthrough; 4413 case 4: diffs |= __it_diff(a, b, 32); 4414 break; 4415 default: 4416 slow: 4417 return memcmp(a - meta_len, b - meta_len, meta_len); 4418 } 4419 return diffs; 4420 } 4421 4422 static inline bool skb_metadata_differs(const struct sk_buff *skb_a, 4423 const struct sk_buff *skb_b) 4424 { 4425 u8 len_a = skb_metadata_len(skb_a); 4426 u8 len_b = skb_metadata_len(skb_b); 4427 4428 if (!(len_a | len_b)) 4429 return false; 4430 4431 return len_a != len_b ? 4432 true : __skb_metadata_differs(skb_a, skb_b, len_a); 4433 } 4434 4435 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len) 4436 { 4437 skb_shinfo(skb)->meta_len = meta_len; 4438 } 4439 4440 static inline void skb_metadata_clear(struct sk_buff *skb) 4441 { 4442 skb_metadata_set(skb, 0); 4443 } 4444 4445 struct sk_buff *skb_clone_sk(struct sk_buff *skb); 4446 4447 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 4448 4449 void skb_clone_tx_timestamp(struct sk_buff *skb); 4450 bool skb_defer_rx_timestamp(struct sk_buff *skb); 4451 4452 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 4453 4454 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 4455 { 4456 } 4457 4458 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 4459 { 4460 return false; 4461 } 4462 4463 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 4464 4465 /** 4466 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 4467 * 4468 * PHY drivers may accept clones of transmitted packets for 4469 * timestamping via their phy_driver.txtstamp method. These drivers 4470 * must call this function to return the skb back to the stack with a 4471 * timestamp. 4472 * 4473 * @skb: clone of the original outgoing packet 4474 * @hwtstamps: hardware time stamps 4475 * 4476 */ 4477 void skb_complete_tx_timestamp(struct sk_buff *skb, 4478 struct skb_shared_hwtstamps *hwtstamps); 4479 4480 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, 4481 struct skb_shared_hwtstamps *hwtstamps, 4482 struct sock *sk, int tstype); 4483 4484 /** 4485 * skb_tstamp_tx - queue clone of skb with send time stamps 4486 * @orig_skb: the original outgoing packet 4487 * @hwtstamps: hardware time stamps, may be NULL if not available 4488 * 4489 * If the skb has a socket associated, then this function clones the 4490 * skb (thus sharing the actual data and optional structures), stores 4491 * the optional hardware time stamping information (if non NULL) or 4492 * generates a software time stamp (otherwise), then queues the clone 4493 * to the error queue of the socket. Errors are silently ignored. 4494 */ 4495 void skb_tstamp_tx(struct sk_buff *orig_skb, 4496 struct skb_shared_hwtstamps *hwtstamps); 4497 4498 /** 4499 * skb_tx_timestamp() - Driver hook for transmit timestamping 4500 * 4501 * Ethernet MAC Drivers should call this function in their hard_xmit() 4502 * function immediately before giving the sk_buff to the MAC hardware. 4503 * 4504 * Specifically, one should make absolutely sure that this function is 4505 * called before TX completion of this packet can trigger. Otherwise 4506 * the packet could potentially already be freed. 4507 * 4508 * @skb: A socket buffer. 4509 */ 4510 static inline void skb_tx_timestamp(struct sk_buff *skb) 4511 { 4512 skb_clone_tx_timestamp(skb); 4513 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) 4514 skb_tstamp_tx(skb, NULL); 4515 } 4516 4517 /** 4518 * skb_complete_wifi_ack - deliver skb with wifi status 4519 * 4520 * @skb: the original outgoing packet 4521 * @acked: ack status 4522 * 4523 */ 4524 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 4525 4526 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 4527 __sum16 __skb_checksum_complete(struct sk_buff *skb); 4528 4529 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 4530 { 4531 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) || 4532 skb->csum_valid || 4533 (skb->ip_summed == CHECKSUM_PARTIAL && 4534 skb_checksum_start_offset(skb) >= 0)); 4535 } 4536 4537 /** 4538 * skb_checksum_complete - Calculate checksum of an entire packet 4539 * @skb: packet to process 4540 * 4541 * This function calculates the checksum over the entire packet plus 4542 * the value of skb->csum. The latter can be used to supply the 4543 * checksum of a pseudo header as used by TCP/UDP. It returns the 4544 * checksum. 4545 * 4546 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 4547 * this function can be used to verify that checksum on received 4548 * packets. In that case the function should return zero if the 4549 * checksum is correct. In particular, this function will return zero 4550 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 4551 * hardware has already verified the correctness of the checksum. 4552 */ 4553 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 4554 { 4555 return skb_csum_unnecessary(skb) ? 4556 0 : __skb_checksum_complete(skb); 4557 } 4558 4559 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb) 4560 { 4561 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4562 if (skb->csum_level == 0) 4563 skb->ip_summed = CHECKSUM_NONE; 4564 else 4565 skb->csum_level--; 4566 } 4567 } 4568 4569 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) 4570 { 4571 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4572 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 4573 skb->csum_level++; 4574 } else if (skb->ip_summed == CHECKSUM_NONE) { 4575 skb->ip_summed = CHECKSUM_UNNECESSARY; 4576 skb->csum_level = 0; 4577 } 4578 } 4579 4580 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb) 4581 { 4582 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4583 skb->ip_summed = CHECKSUM_NONE; 4584 skb->csum_level = 0; 4585 } 4586 } 4587 4588 /* Check if we need to perform checksum complete validation. 4589 * 4590 * Returns true if checksum complete is needed, false otherwise 4591 * (either checksum is unnecessary or zero checksum is allowed). 4592 */ 4593 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, 4594 bool zero_okay, 4595 __sum16 check) 4596 { 4597 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) { 4598 skb->csum_valid = 1; 4599 __skb_decr_checksum_unnecessary(skb); 4600 return false; 4601 } 4602 4603 return true; 4604 } 4605 4606 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly 4607 * in checksum_init. 4608 */ 4609 #define CHECKSUM_BREAK 76 4610 4611 /* Unset checksum-complete 4612 * 4613 * Unset checksum complete can be done when packet is being modified 4614 * (uncompressed for instance) and checksum-complete value is 4615 * invalidated. 4616 */ 4617 static inline void skb_checksum_complete_unset(struct sk_buff *skb) 4618 { 4619 if (skb->ip_summed == CHECKSUM_COMPLETE) 4620 skb->ip_summed = CHECKSUM_NONE; 4621 } 4622 4623 /* Validate (init) checksum based on checksum complete. 4624 * 4625 * Return values: 4626 * 0: checksum is validated or try to in skb_checksum_complete. In the latter 4627 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo 4628 * checksum is stored in skb->csum for use in __skb_checksum_complete 4629 * non-zero: value of invalid checksum 4630 * 4631 */ 4632 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, 4633 bool complete, 4634 __wsum psum) 4635 { 4636 if (skb->ip_summed == CHECKSUM_COMPLETE) { 4637 if (!csum_fold(csum_add(psum, skb->csum))) { 4638 skb->csum_valid = 1; 4639 return 0; 4640 } 4641 } 4642 4643 skb->csum = psum; 4644 4645 if (complete || skb->len <= CHECKSUM_BREAK) { 4646 __sum16 csum; 4647 4648 csum = __skb_checksum_complete(skb); 4649 skb->csum_valid = !csum; 4650 return csum; 4651 } 4652 4653 return 0; 4654 } 4655 4656 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) 4657 { 4658 return 0; 4659 } 4660 4661 /* Perform checksum validate (init). Note that this is a macro since we only 4662 * want to calculate the pseudo header which is an input function if necessary. 4663 * First we try to validate without any computation (checksum unnecessary) and 4664 * then calculate based on checksum complete calling the function to compute 4665 * pseudo header. 4666 * 4667 * Return values: 4668 * 0: checksum is validated or try to in skb_checksum_complete 4669 * non-zero: value of invalid checksum 4670 */ 4671 #define __skb_checksum_validate(skb, proto, complete, \ 4672 zero_okay, check, compute_pseudo) \ 4673 ({ \ 4674 __sum16 __ret = 0; \ 4675 skb->csum_valid = 0; \ 4676 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ 4677 __ret = __skb_checksum_validate_complete(skb, \ 4678 complete, compute_pseudo(skb, proto)); \ 4679 __ret; \ 4680 }) 4681 4682 #define skb_checksum_init(skb, proto, compute_pseudo) \ 4683 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) 4684 4685 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ 4686 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) 4687 4688 #define skb_checksum_validate(skb, proto, compute_pseudo) \ 4689 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) 4690 4691 #define skb_checksum_validate_zero_check(skb, proto, check, \ 4692 compute_pseudo) \ 4693 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo) 4694 4695 #define skb_checksum_simple_validate(skb) \ 4696 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) 4697 4698 static inline bool __skb_checksum_convert_check(struct sk_buff *skb) 4699 { 4700 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid); 4701 } 4702 4703 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo) 4704 { 4705 skb->csum = ~pseudo; 4706 skb->ip_summed = CHECKSUM_COMPLETE; 4707 } 4708 4709 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \ 4710 do { \ 4711 if (__skb_checksum_convert_check(skb)) \ 4712 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \ 4713 } while (0) 4714 4715 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr, 4716 u16 start, u16 offset) 4717 { 4718 skb->ip_summed = CHECKSUM_PARTIAL; 4719 skb->csum_start = ((unsigned char *)ptr + start) - skb->head; 4720 skb->csum_offset = offset - start; 4721 } 4722 4723 /* Update skbuf and packet to reflect the remote checksum offload operation. 4724 * When called, ptr indicates the starting point for skb->csum when 4725 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete 4726 * here, skb_postpull_rcsum is done so skb->csum start is ptr. 4727 */ 4728 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr, 4729 int start, int offset, bool nopartial) 4730 { 4731 __wsum delta; 4732 4733 if (!nopartial) { 4734 skb_remcsum_adjust_partial(skb, ptr, start, offset); 4735 return; 4736 } 4737 4738 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) { 4739 __skb_checksum_complete(skb); 4740 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data); 4741 } 4742 4743 delta = remcsum_adjust(ptr, skb->csum, start, offset); 4744 4745 /* Adjust skb->csum since we changed the packet */ 4746 skb->csum = csum_add(skb->csum, delta); 4747 } 4748 4749 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb) 4750 { 4751 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4752 return (void *)(skb->_nfct & NFCT_PTRMASK); 4753 #else 4754 return NULL; 4755 #endif 4756 } 4757 4758 static inline unsigned long skb_get_nfct(const struct sk_buff *skb) 4759 { 4760 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4761 return skb->_nfct; 4762 #else 4763 return 0UL; 4764 #endif 4765 } 4766 4767 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct) 4768 { 4769 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4770 skb->slow_gro |= !!nfct; 4771 skb->_nfct = nfct; 4772 #endif 4773 } 4774 4775 #ifdef CONFIG_SKB_EXTENSIONS 4776 enum skb_ext_id { 4777 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 4778 SKB_EXT_BRIDGE_NF, 4779 #endif 4780 #ifdef CONFIG_XFRM 4781 SKB_EXT_SEC_PATH, 4782 #endif 4783 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 4784 TC_SKB_EXT, 4785 #endif 4786 #if IS_ENABLED(CONFIG_MPTCP) 4787 SKB_EXT_MPTCP, 4788 #endif 4789 #if IS_ENABLED(CONFIG_MCTP_FLOWS) 4790 SKB_EXT_MCTP, 4791 #endif 4792 SKB_EXT_NUM, /* must be last */ 4793 }; 4794 4795 /** 4796 * struct skb_ext - sk_buff extensions 4797 * @refcnt: 1 on allocation, deallocated on 0 4798 * @offset: offset to add to @data to obtain extension address 4799 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units 4800 * @data: start of extension data, variable sized 4801 * 4802 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows 4803 * to use 'u8' types while allowing up to 2kb worth of extension data. 4804 */ 4805 struct skb_ext { 4806 refcount_t refcnt; 4807 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */ 4808 u8 chunks; /* same */ 4809 char data[] __aligned(8); 4810 }; 4811 4812 struct skb_ext *__skb_ext_alloc(gfp_t flags); 4813 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, 4814 struct skb_ext *ext); 4815 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); 4816 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); 4817 void __skb_ext_put(struct skb_ext *ext); 4818 4819 static inline void skb_ext_put(struct sk_buff *skb) 4820 { 4821 if (skb->active_extensions) 4822 __skb_ext_put(skb->extensions); 4823 } 4824 4825 static inline void __skb_ext_copy(struct sk_buff *dst, 4826 const struct sk_buff *src) 4827 { 4828 dst->active_extensions = src->active_extensions; 4829 4830 if (src->active_extensions) { 4831 struct skb_ext *ext = src->extensions; 4832 4833 refcount_inc(&ext->refcnt); 4834 dst->extensions = ext; 4835 } 4836 } 4837 4838 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src) 4839 { 4840 skb_ext_put(dst); 4841 __skb_ext_copy(dst, src); 4842 } 4843 4844 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i) 4845 { 4846 return !!ext->offset[i]; 4847 } 4848 4849 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id) 4850 { 4851 return skb->active_extensions & (1 << id); 4852 } 4853 4854 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) 4855 { 4856 if (skb_ext_exist(skb, id)) 4857 __skb_ext_del(skb, id); 4858 } 4859 4860 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id) 4861 { 4862 if (skb_ext_exist(skb, id)) { 4863 struct skb_ext *ext = skb->extensions; 4864 4865 return (void *)ext + (ext->offset[id] << 3); 4866 } 4867 4868 return NULL; 4869 } 4870 4871 static inline void skb_ext_reset(struct sk_buff *skb) 4872 { 4873 if (unlikely(skb->active_extensions)) { 4874 __skb_ext_put(skb->extensions); 4875 skb->active_extensions = 0; 4876 } 4877 } 4878 4879 static inline bool skb_has_extensions(struct sk_buff *skb) 4880 { 4881 return unlikely(skb->active_extensions); 4882 } 4883 #else 4884 static inline void skb_ext_put(struct sk_buff *skb) {} 4885 static inline void skb_ext_reset(struct sk_buff *skb) {} 4886 static inline void skb_ext_del(struct sk_buff *skb, int unused) {} 4887 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {} 4888 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {} 4889 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; } 4890 #endif /* CONFIG_SKB_EXTENSIONS */ 4891 4892 static inline void nf_reset_ct(struct sk_buff *skb) 4893 { 4894 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4895 nf_conntrack_put(skb_nfct(skb)); 4896 skb->_nfct = 0; 4897 #endif 4898 } 4899 4900 static inline void nf_reset_trace(struct sk_buff *skb) 4901 { 4902 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 4903 skb->nf_trace = 0; 4904 #endif 4905 } 4906 4907 static inline void ipvs_reset(struct sk_buff *skb) 4908 { 4909 #if IS_ENABLED(CONFIG_IP_VS) 4910 skb->ipvs_property = 0; 4911 #endif 4912 } 4913 4914 /* Note: This doesn't put any conntrack info in dst. */ 4915 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src, 4916 bool copy) 4917 { 4918 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4919 dst->_nfct = src->_nfct; 4920 nf_conntrack_get(skb_nfct(src)); 4921 #endif 4922 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 4923 if (copy) 4924 dst->nf_trace = src->nf_trace; 4925 #endif 4926 } 4927 4928 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 4929 { 4930 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4931 nf_conntrack_put(skb_nfct(dst)); 4932 #endif 4933 dst->slow_gro = src->slow_gro; 4934 __nf_copy(dst, src, true); 4935 } 4936 4937 #ifdef CONFIG_NETWORK_SECMARK 4938 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4939 { 4940 to->secmark = from->secmark; 4941 } 4942 4943 static inline void skb_init_secmark(struct sk_buff *skb) 4944 { 4945 skb->secmark = 0; 4946 } 4947 #else 4948 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4949 { } 4950 4951 static inline void skb_init_secmark(struct sk_buff *skb) 4952 { } 4953 #endif 4954 4955 static inline int secpath_exists(const struct sk_buff *skb) 4956 { 4957 #ifdef CONFIG_XFRM 4958 return skb_ext_exist(skb, SKB_EXT_SEC_PATH); 4959 #else 4960 return 0; 4961 #endif 4962 } 4963 4964 static inline bool skb_irq_freeable(const struct sk_buff *skb) 4965 { 4966 return !skb->destructor && 4967 !secpath_exists(skb) && 4968 !skb_nfct(skb) && 4969 !skb->_skb_refdst && 4970 !skb_has_frag_list(skb); 4971 } 4972 4973 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 4974 { 4975 skb->queue_mapping = queue_mapping; 4976 } 4977 4978 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 4979 { 4980 return skb->queue_mapping; 4981 } 4982 4983 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 4984 { 4985 to->queue_mapping = from->queue_mapping; 4986 } 4987 4988 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 4989 { 4990 skb->queue_mapping = rx_queue + 1; 4991 } 4992 4993 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 4994 { 4995 return skb->queue_mapping - 1; 4996 } 4997 4998 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 4999 { 5000 return skb->queue_mapping != 0; 5001 } 5002 5003 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val) 5004 { 5005 skb->dst_pending_confirm = val; 5006 } 5007 5008 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb) 5009 { 5010 return skb->dst_pending_confirm != 0; 5011 } 5012 5013 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb) 5014 { 5015 #ifdef CONFIG_XFRM 5016 return skb_ext_find(skb, SKB_EXT_SEC_PATH); 5017 #else 5018 return NULL; 5019 #endif 5020 } 5021 5022 static inline bool skb_is_gso(const struct sk_buff *skb) 5023 { 5024 return skb_shinfo(skb)->gso_size; 5025 } 5026 5027 /* Note: Should be called only if skb_is_gso(skb) is true */ 5028 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 5029 { 5030 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 5031 } 5032 5033 /* Note: Should be called only if skb_is_gso(skb) is true */ 5034 static inline bool skb_is_gso_sctp(const struct sk_buff *skb) 5035 { 5036 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP; 5037 } 5038 5039 /* Note: Should be called only if skb_is_gso(skb) is true */ 5040 static inline bool skb_is_gso_tcp(const struct sk_buff *skb) 5041 { 5042 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6); 5043 } 5044 5045 static inline void skb_gso_reset(struct sk_buff *skb) 5046 { 5047 skb_shinfo(skb)->gso_size = 0; 5048 skb_shinfo(skb)->gso_segs = 0; 5049 skb_shinfo(skb)->gso_type = 0; 5050 } 5051 5052 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo, 5053 u16 increment) 5054 { 5055 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 5056 return; 5057 shinfo->gso_size += increment; 5058 } 5059 5060 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo, 5061 u16 decrement) 5062 { 5063 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 5064 return; 5065 shinfo->gso_size -= decrement; 5066 } 5067 5068 void __skb_warn_lro_forwarding(const struct sk_buff *skb); 5069 5070 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 5071 { 5072 /* LRO sets gso_size but not gso_type, whereas if GSO is really 5073 * wanted then gso_type will be set. */ 5074 const struct skb_shared_info *shinfo = skb_shinfo(skb); 5075 5076 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 5077 unlikely(shinfo->gso_type == 0)) { 5078 __skb_warn_lro_forwarding(skb); 5079 return true; 5080 } 5081 return false; 5082 } 5083 5084 static inline void skb_forward_csum(struct sk_buff *skb) 5085 { 5086 /* Unfortunately we don't support this one. Any brave souls? */ 5087 if (skb->ip_summed == CHECKSUM_COMPLETE) 5088 skb->ip_summed = CHECKSUM_NONE; 5089 } 5090 5091 /** 5092 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 5093 * @skb: skb to check 5094 * 5095 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 5096 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 5097 * use this helper, to document places where we make this assertion. 5098 */ 5099 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 5100 { 5101 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE); 5102 } 5103 5104 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 5105 5106 int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 5107 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, 5108 unsigned int transport_len, 5109 __sum16(*skb_chkf)(struct sk_buff *skb)); 5110 5111 /** 5112 * skb_head_is_locked - Determine if the skb->head is locked down 5113 * @skb: skb to check 5114 * 5115 * The head on skbs build around a head frag can be removed if they are 5116 * not cloned. This function returns true if the skb head is locked down 5117 * due to either being allocated via kmalloc, or by being a clone with 5118 * multiple references to the head. 5119 */ 5120 static inline bool skb_head_is_locked(const struct sk_buff *skb) 5121 { 5122 return !skb->head_frag || skb_cloned(skb); 5123 } 5124 5125 /* Local Checksum Offload. 5126 * Compute outer checksum based on the assumption that the 5127 * inner checksum will be offloaded later. 5128 * See Documentation/networking/checksum-offloads.rst for 5129 * explanation of how this works. 5130 * Fill in outer checksum adjustment (e.g. with sum of outer 5131 * pseudo-header) before calling. 5132 * Also ensure that inner checksum is in linear data area. 5133 */ 5134 static inline __wsum lco_csum(struct sk_buff *skb) 5135 { 5136 unsigned char *csum_start = skb_checksum_start(skb); 5137 unsigned char *l4_hdr = skb_transport_header(skb); 5138 __wsum partial; 5139 5140 /* Start with complement of inner checksum adjustment */ 5141 partial = ~csum_unfold(*(__force __sum16 *)(csum_start + 5142 skb->csum_offset)); 5143 5144 /* Add in checksum of our headers (incl. outer checksum 5145 * adjustment filled in by caller) and return result. 5146 */ 5147 return csum_partial(l4_hdr, csum_start - l4_hdr, partial); 5148 } 5149 5150 static inline bool skb_is_redirected(const struct sk_buff *skb) 5151 { 5152 return skb->redirected; 5153 } 5154 5155 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress) 5156 { 5157 skb->redirected = 1; 5158 #ifdef CONFIG_NET_REDIRECT 5159 skb->from_ingress = from_ingress; 5160 if (skb->from_ingress) 5161 skb_clear_tstamp(skb); 5162 #endif 5163 } 5164 5165 static inline void skb_reset_redirect(struct sk_buff *skb) 5166 { 5167 skb->redirected = 0; 5168 } 5169 5170 static inline void skb_set_redirected_noclear(struct sk_buff *skb, 5171 bool from_ingress) 5172 { 5173 skb->redirected = 1; 5174 #ifdef CONFIG_NET_REDIRECT 5175 skb->from_ingress = from_ingress; 5176 #endif 5177 } 5178 5179 static inline bool skb_csum_is_sctp(struct sk_buff *skb) 5180 { 5181 #if IS_ENABLED(CONFIG_IP_SCTP) 5182 return skb->csum_not_inet; 5183 #else 5184 return 0; 5185 #endif 5186 } 5187 5188 static inline void skb_reset_csum_not_inet(struct sk_buff *skb) 5189 { 5190 skb->ip_summed = CHECKSUM_NONE; 5191 #if IS_ENABLED(CONFIG_IP_SCTP) 5192 skb->csum_not_inet = 0; 5193 #endif 5194 } 5195 5196 static inline void skb_set_kcov_handle(struct sk_buff *skb, 5197 const u64 kcov_handle) 5198 { 5199 #ifdef CONFIG_KCOV 5200 skb->kcov_handle = kcov_handle; 5201 #endif 5202 } 5203 5204 static inline u64 skb_get_kcov_handle(struct sk_buff *skb) 5205 { 5206 #ifdef CONFIG_KCOV 5207 return skb->kcov_handle; 5208 #else 5209 return 0; 5210 #endif 5211 } 5212 5213 static inline void skb_mark_for_recycle(struct sk_buff *skb) 5214 { 5215 #ifdef CONFIG_PAGE_POOL 5216 skb->pp_recycle = 1; 5217 #endif 5218 } 5219 5220 ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter, 5221 ssize_t maxsize, gfp_t gfp); 5222 5223 #endif /* __KERNEL__ */ 5224 #endif /* _LINUX_SKBUFF_H */ 5225