1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Definitions for the 'struct sk_buff' memory handlers. 4 * 5 * Authors: 6 * Alan Cox, <gw4pts@gw4pts.ampr.org> 7 * Florian La Roche, <rzsfl@rz.uni-sb.de> 8 */ 9 10#ifndef _LINUX_SKBUFF_H 11#define _LINUX_SKBUFF_H 12 13#include <linux/kernel.h> 14#include <linux/compiler.h> 15#include <linux/time.h> 16#include <linux/bug.h> 17#include <linux/bvec.h> 18#include <linux/cache.h> 19#include <linux/rbtree.h> 20#include <linux/socket.h> 21#include <linux/refcount.h> 22 23#include <linux/atomic.h> 24#include <asm/types.h> 25#include <linux/spinlock.h> 26#include <net/checksum.h> 27#include <linux/rcupdate.h> 28#include <linux/dma-mapping.h> 29#include <linux/netdev_features.h> 30#include <net/flow_dissector.h> 31#include <linux/in6.h> 32#include <linux/if_packet.h> 33#include <linux/llist.h> 34#include <net/flow.h> 35#if IS_ENABLED(CONFIG_NF_CONNTRACK) 36#include <linux/netfilter/nf_conntrack_common.h> 37#endif 38#include <net/net_debug.h> 39#include <net/dropreason-core.h> 40#include <net/netmem.h> 41 42/** 43 * DOC: skb checksums 44 * 45 * The interface for checksum offload between the stack and networking drivers 46 * is as follows... 47 * 48 * IP checksum related features 49 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 50 * 51 * Drivers advertise checksum offload capabilities in the features of a device. 52 * From the stack's point of view these are capabilities offered by the driver. 53 * A driver typically only advertises features that it is capable of offloading 54 * to its device. 55 * 56 * .. flat-table:: Checksum related device features 57 * :widths: 1 10 58 * 59 * * - %NETIF_F_HW_CSUM 60 * - The driver (or its device) is able to compute one 61 * IP (one's complement) checksum for any combination 62 * of protocols or protocol layering. The checksum is 63 * computed and set in a packet per the CHECKSUM_PARTIAL 64 * interface (see below). 65 * 66 * * - %NETIF_F_IP_CSUM 67 * - Driver (device) is only able to checksum plain 68 * TCP or UDP packets over IPv4. These are specifically 69 * unencapsulated packets of the form IPv4|TCP or 70 * IPv4|UDP where the Protocol field in the IPv4 header 71 * is TCP or UDP. The IPv4 header may contain IP options. 72 * This feature cannot be set in features for a device 73 * with NETIF_F_HW_CSUM also set. This feature is being 74 * DEPRECATED (see below). 75 * 76 * * - %NETIF_F_IPV6_CSUM 77 * - Driver (device) is only able to checksum plain 78 * TCP or UDP packets over IPv6. These are specifically 79 * unencapsulated packets of the form IPv6|TCP or 80 * IPv6|UDP where the Next Header field in the IPv6 81 * header is either TCP or UDP. IPv6 extension headers 82 * are not supported with this feature. This feature 83 * cannot be set in features for a device with 84 * NETIF_F_HW_CSUM also set. This feature is being 85 * DEPRECATED (see below). 86 * 87 * * - %NETIF_F_RXCSUM 88 * - Driver (device) performs receive checksum offload. 89 * This flag is only used to disable the RX checksum 90 * feature for a device. The stack will accept receive 91 * checksum indication in packets received on a device 92 * regardless of whether NETIF_F_RXCSUM is set. 93 * 94 * Checksumming of received packets by device 95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 * 97 * Indication of checksum verification is set in &sk_buff.ip_summed. 98 * Possible values are: 99 * 100 * - %CHECKSUM_NONE 101 * 102 * Device did not checksum this packet e.g. due to lack of capabilities. 103 * The packet contains full (though not verified) checksum in packet but 104 * not in skb->csum. Thus, skb->csum is undefined in this case. 105 * 106 * - %CHECKSUM_UNNECESSARY 107 * 108 * The hardware you're dealing with doesn't calculate the full checksum 109 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums 110 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY 111 * if their checksums are okay. &sk_buff.csum is still undefined in this case 112 * though. A driver or device must never modify the checksum field in the 113 * packet even if checksum is verified. 114 * 115 * %CHECKSUM_UNNECESSARY is applicable to following protocols: 116 * 117 * - TCP: IPv6 and IPv4. 118 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a 119 * zero UDP checksum for either IPv4 or IPv6, the networking stack 120 * may perform further validation in this case. 121 * - GRE: only if the checksum is present in the header. 122 * - SCTP: indicates the CRC in SCTP header has been validated. 123 * - FCOE: indicates the CRC in FC frame has been validated. 124 * 125 * &sk_buff.csum_level indicates the number of consecutive checksums found in 126 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY. 127 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet 128 * and a device is able to verify the checksums for UDP (possibly zero), 129 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to 130 * two. If the device were only able to verify the UDP checksum and not 131 * GRE, either because it doesn't support GRE checksum or because GRE 132 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is 133 * not considered in this case). 134 * 135 * - %CHECKSUM_COMPLETE 136 * 137 * This is the most generic way. The device supplied checksum of the _whole_ 138 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the 139 * hardware doesn't need to parse L3/L4 headers to implement this. 140 * 141 * Notes: 142 * 143 * - Even if device supports only some protocols, but is able to produce 144 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 145 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols. 146 * 147 * - %CHECKSUM_PARTIAL 148 * 149 * A checksum is set up to be offloaded to a device as described in the 150 * output description for CHECKSUM_PARTIAL. This may occur on a packet 151 * received directly from another Linux OS, e.g., a virtualized Linux kernel 152 * on the same host, or it may be set in the input path in GRO or remote 153 * checksum offload. For the purposes of checksum verification, the checksum 154 * referred to by skb->csum_start + skb->csum_offset and any preceding 155 * checksums in the packet are considered verified. Any checksums in the 156 * packet that are after the checksum being offloaded are not considered to 157 * be verified. 158 * 159 * Checksumming on transmit for non-GSO 160 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 161 * 162 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet. 163 * Values are: 164 * 165 * - %CHECKSUM_PARTIAL 166 * 167 * The driver is required to checksum the packet as seen by hard_start_xmit() 168 * from &sk_buff.csum_start up to the end, and to record/write the checksum at 169 * offset &sk_buff.csum_start + &sk_buff.csum_offset. 170 * A driver may verify that the 171 * csum_start and csum_offset values are valid values given the length and 172 * offset of the packet, but it should not attempt to validate that the 173 * checksum refers to a legitimate transport layer checksum -- it is the 174 * purview of the stack to validate that csum_start and csum_offset are set 175 * correctly. 176 * 177 * When the stack requests checksum offload for a packet, the driver MUST 178 * ensure that the checksum is set correctly. A driver can either offload the 179 * checksum calculation to the device, or call skb_checksum_help (in the case 180 * that the device does not support offload for a particular checksum). 181 * 182 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of 183 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate 184 * checksum offload capability. 185 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based 186 * on network device checksumming capabilities: if a packet does not match 187 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of 188 * &sk_buff.csum_not_inet, see :ref:`crc`) 189 * is called to resolve the checksum. 190 * 191 * - %CHECKSUM_NONE 192 * 193 * The skb was already checksummed by the protocol, or a checksum is not 194 * required. 195 * 196 * - %CHECKSUM_UNNECESSARY 197 * 198 * This has the same meaning as CHECKSUM_NONE for checksum offload on 199 * output. 200 * 201 * - %CHECKSUM_COMPLETE 202 * 203 * Not used in checksum output. If a driver observes a packet with this value 204 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set. 205 * 206 * .. _crc: 207 * 208 * Non-IP checksum (CRC) offloads 209 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 210 * 211 * .. flat-table:: 212 * :widths: 1 10 213 * 214 * * - %NETIF_F_SCTP_CRC 215 * - This feature indicates that a device is capable of 216 * offloading the SCTP CRC in a packet. To perform this offload the stack 217 * will set csum_start and csum_offset accordingly, set ip_summed to 218 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication 219 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c. 220 * A driver that supports both IP checksum offload and SCTP CRC32c offload 221 * must verify which offload is configured for a packet by testing the 222 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to 223 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1. 224 * 225 * * - %NETIF_F_FCOE_CRC 226 * - This feature indicates that a device is capable of offloading the FCOE 227 * CRC in a packet. To perform this offload the stack will set ip_summed 228 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset 229 * accordingly. Note that there is no indication in the skbuff that the 230 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports 231 * both IP checksum offload and FCOE CRC offload must verify which offload 232 * is configured for a packet, presumably by inspecting packet headers. 233 * 234 * Checksumming on output with GSO 235 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 236 * 237 * In the case of a GSO packet (skb_is_gso() is true), checksum offload 238 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the 239 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as 240 * part of the GSO operation is implied. If a checksum is being offloaded 241 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and 242 * csum_offset are set to refer to the outermost checksum being offloaded 243 * (two offloaded checksums are possible with UDP encapsulation). 244 */ 245 246/* Don't change this without changing skb_csum_unnecessary! */ 247#define CHECKSUM_NONE 0 248#define CHECKSUM_UNNECESSARY 1 249#define CHECKSUM_COMPLETE 2 250#define CHECKSUM_PARTIAL 3 251 252/* Maximum value in skb->csum_level */ 253#define SKB_MAX_CSUM_LEVEL 3 254 255#define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) 256#define SKB_WITH_OVERHEAD(X) \ 257 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 258 259/* For X bytes available in skb->head, what is the minimal 260 * allocation needed, knowing struct skb_shared_info needs 261 * to be aligned. 262 */ 263#define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \ 264 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 265 266#define SKB_MAX_ORDER(X, ORDER) \ 267 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 268#define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 269#define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 270 271/* return minimum truesize of one skb containing X bytes of data */ 272#define SKB_TRUESIZE(X) ((X) + \ 273 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 274 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 275 276struct ahash_request; 277struct net_device; 278struct scatterlist; 279struct pipe_inode_info; 280struct iov_iter; 281struct napi_struct; 282struct bpf_prog; 283union bpf_attr; 284struct skb_ext; 285struct ts_config; 286 287#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 288struct 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 */ 322struct 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 337struct 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 348struct 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 356extern int sysctl_max_skb_frags; 357 358/* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to 359 * segment using its current segmentation instead. 360 */ 361#define GSO_BY_FRAGS 0xFFFF 362 363typedef struct skb_frag { 364 netmem_ref netmem; 365 unsigned int len; 366 unsigned int offset; 367} skb_frag_t; 368 369/** 370 * skb_frag_size() - Returns the size of a skb fragment 371 * @frag: skb fragment 372 */ 373static inline unsigned int skb_frag_size(const skb_frag_t *frag) 374{ 375 return frag->len; 376} 377 378/** 379 * skb_frag_size_set() - Sets the size of a skb fragment 380 * @frag: skb fragment 381 * @size: size of fragment 382 */ 383static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 384{ 385 frag->len = size; 386} 387 388/** 389 * skb_frag_size_add() - Increments the size of a skb fragment by @delta 390 * @frag: skb fragment 391 * @delta: value to add 392 */ 393static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 394{ 395 frag->len += delta; 396} 397 398/** 399 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta 400 * @frag: skb fragment 401 * @delta: value to subtract 402 */ 403static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 404{ 405 frag->len -= delta; 406} 407 408/** 409 * skb_frag_must_loop - Test if %p is a high memory page 410 * @p: fragment's page 411 */ 412static inline bool skb_frag_must_loop(struct page *p) 413{ 414#if defined(CONFIG_HIGHMEM) 415 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p)) 416 return true; 417#endif 418 return false; 419} 420 421/** 422 * skb_frag_foreach_page - loop over pages in a fragment 423 * 424 * @f: skb frag to operate on 425 * @f_off: offset from start of f->netmem 426 * @f_len: length from f_off to loop over 427 * @p: (temp var) current page 428 * @p_off: (temp var) offset from start of current page, 429 * non-zero only on first page. 430 * @p_len: (temp var) length in current page, 431 * < PAGE_SIZE only on first and last page. 432 * @copied: (temp var) length so far, excluding current p_len. 433 * 434 * A fragment can hold a compound page, in which case per-page 435 * operations, notably kmap_atomic, must be called for each 436 * regular page. 437 */ 438#define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \ 439 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \ 440 p_off = (f_off) & (PAGE_SIZE - 1), \ 441 p_len = skb_frag_must_loop(p) ? \ 442 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \ 443 copied = 0; \ 444 copied < f_len; \ 445 copied += p_len, p++, p_off = 0, \ 446 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \ 447 448/** 449 * struct skb_shared_hwtstamps - hardware time stamps 450 * @hwtstamp: hardware time stamp transformed into duration 451 * since arbitrary point in time 452 * @netdev_data: address/cookie of network device driver used as 453 * reference to actual hardware time stamp 454 * 455 * Software time stamps generated by ktime_get_real() are stored in 456 * skb->tstamp. 457 * 458 * hwtstamps can only be compared against other hwtstamps from 459 * the same device. 460 * 461 * This structure is attached to packets as part of the 462 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 463 */ 464struct skb_shared_hwtstamps { 465 union { 466 ktime_t hwtstamp; 467 void *netdev_data; 468 }; 469}; 470 471/* Definitions for tx_flags in struct skb_shared_info */ 472enum { 473 /* generate hardware time stamp */ 474 SKBTX_HW_TSTAMP = 1 << 0, 475 476 /* generate software time stamp when queueing packet to NIC */ 477 SKBTX_SW_TSTAMP = 1 << 1, 478 479 /* device driver is going to provide hardware time stamp */ 480 SKBTX_IN_PROGRESS = 1 << 2, 481 482 /* generate hardware time stamp based on cycles if supported */ 483 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, 484 485 /* generate wifi status information (where possible) */ 486 SKBTX_WIFI_STATUS = 1 << 4, 487 488 /* determine hardware time stamp based on time or cycles */ 489 SKBTX_HW_TSTAMP_NETDEV = 1 << 5, 490 491 /* generate software time stamp when entering packet scheduling */ 492 SKBTX_SCHED_TSTAMP = 1 << 6, 493}; 494 495#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ 496 SKBTX_SCHED_TSTAMP) 497#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ 498 SKBTX_HW_TSTAMP_USE_CYCLES | \ 499 SKBTX_ANY_SW_TSTAMP) 500 501/* Definitions for flags in struct skb_shared_info */ 502enum { 503 /* use zcopy routines */ 504 SKBFL_ZEROCOPY_ENABLE = BIT(0), 505 506 /* This indicates at least one fragment might be overwritten 507 * (as in vmsplice(), sendfile() ...) 508 * If we need to compute a TX checksum, we'll need to copy 509 * all frags to avoid possible bad checksum 510 */ 511 SKBFL_SHARED_FRAG = BIT(1), 512 513 /* segment contains only zerocopy data and should not be 514 * charged to the kernel memory. 515 */ 516 SKBFL_PURE_ZEROCOPY = BIT(2), 517 518 SKBFL_DONT_ORPHAN = BIT(3), 519 520 /* page references are managed by the ubuf_info, so it's safe to 521 * use frags only up until ubuf_info is released 522 */ 523 SKBFL_MANAGED_FRAG_REFS = BIT(4), 524}; 525 526#define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG) 527#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \ 528 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS) 529 530/* 531 * The callback notifies userspace to release buffers when skb DMA is done in 532 * lower device, the skb last reference should be 0 when calling this. 533 * The zerocopy_success argument is true if zero copy transmit occurred, 534 * false on data copy or out of memory error caused by data copy attempt. 535 * The ctx field is used to track device context. 536 * The desc field is used to track userspace buffer index. 537 */ 538struct ubuf_info { 539 void (*callback)(struct sk_buff *, struct ubuf_info *, 540 bool zerocopy_success); 541 refcount_t refcnt; 542 u8 flags; 543}; 544 545struct ubuf_info_msgzc { 546 struct ubuf_info ubuf; 547 548 union { 549 struct { 550 unsigned long desc; 551 void *ctx; 552 }; 553 struct { 554 u32 id; 555 u16 len; 556 u16 zerocopy:1; 557 u32 bytelen; 558 }; 559 }; 560 561 struct mmpin { 562 struct user_struct *user; 563 unsigned int num_pg; 564 } mmp; 565}; 566 567#define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg)) 568#define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \ 569 ubuf) 570 571int mm_account_pinned_pages(struct mmpin *mmp, size_t size); 572void mm_unaccount_pinned_pages(struct mmpin *mmp); 573 574/* Preserve some data across TX submission and completion. 575 * 576 * Note, this state is stored in the driver. Extending the layout 577 * might need some special care. 578 */ 579struct xsk_tx_metadata_compl { 580 __u64 *tx_timestamp; 581}; 582 583/* This data is invariant across clones and lives at 584 * the end of the header data, ie. at skb->end. 585 */ 586struct skb_shared_info { 587 __u8 flags; 588 __u8 meta_len; 589 __u8 nr_frags; 590 __u8 tx_flags; 591 unsigned short gso_size; 592 /* Warning: this field is not always filled in (UFO)! */ 593 unsigned short gso_segs; 594 struct sk_buff *frag_list; 595 union { 596 struct skb_shared_hwtstamps hwtstamps; 597 struct xsk_tx_metadata_compl xsk_meta; 598 }; 599 unsigned int gso_type; 600 u32 tskey; 601 602 /* 603 * Warning : all fields before dataref are cleared in __alloc_skb() 604 */ 605 atomic_t dataref; 606 unsigned int xdp_frags_size; 607 608 /* Intermediate layers must ensure that destructor_arg 609 * remains valid until skb destructor */ 610 void * destructor_arg; 611 612 /* must be last field, see pskb_expand_head() */ 613 skb_frag_t frags[MAX_SKB_FRAGS]; 614}; 615 616/** 617 * DOC: dataref and headerless skbs 618 * 619 * Transport layers send out clones of payload skbs they hold for 620 * retransmissions. To allow lower layers of the stack to prepend their headers 621 * we split &skb_shared_info.dataref into two halves. 622 * The lower 16 bits count the overall number of references. 623 * The higher 16 bits indicate how many of the references are payload-only. 624 * skb_header_cloned() checks if skb is allowed to add / write the headers. 625 * 626 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr 627 * (via __skb_header_release()). Any clone created from marked skb will get 628 * &sk_buff.hdr_len populated with the available headroom. 629 * If there's the only clone in existence it's able to modify the headroom 630 * at will. The sequence of calls inside the transport layer is:: 631 * 632 * <alloc skb> 633 * skb_reserve() 634 * __skb_header_release() 635 * skb_clone() 636 * // send the clone down the stack 637 * 638 * This is not a very generic construct and it depends on the transport layers 639 * doing the right thing. In practice there's usually only one payload-only skb. 640 * Having multiple payload-only skbs with different lengths of hdr_len is not 641 * possible. The payload-only skbs should never leave their owner. 642 */ 643#define SKB_DATAREF_SHIFT 16 644#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 645 646 647enum { 648 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ 649 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ 650 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ 651}; 652 653enum { 654 SKB_GSO_TCPV4 = 1 << 0, 655 656 /* This indicates the skb is from an untrusted source. */ 657 SKB_GSO_DODGY = 1 << 1, 658 659 /* This indicates the tcp segment has CWR set. */ 660 SKB_GSO_TCP_ECN = 1 << 2, 661 662 SKB_GSO_TCP_FIXEDID = 1 << 3, 663 664 SKB_GSO_TCPV6 = 1 << 4, 665 666 SKB_GSO_FCOE = 1 << 5, 667 668 SKB_GSO_GRE = 1 << 6, 669 670 SKB_GSO_GRE_CSUM = 1 << 7, 671 672 SKB_GSO_IPXIP4 = 1 << 8, 673 674 SKB_GSO_IPXIP6 = 1 << 9, 675 676 SKB_GSO_UDP_TUNNEL = 1 << 10, 677 678 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, 679 680 SKB_GSO_PARTIAL = 1 << 12, 681 682 SKB_GSO_TUNNEL_REMCSUM = 1 << 13, 683 684 SKB_GSO_SCTP = 1 << 14, 685 686 SKB_GSO_ESP = 1 << 15, 687 688 SKB_GSO_UDP = 1 << 16, 689 690 SKB_GSO_UDP_L4 = 1 << 17, 691 692 SKB_GSO_FRAGLIST = 1 << 18, 693}; 694 695#if BITS_PER_LONG > 32 696#define NET_SKBUFF_DATA_USES_OFFSET 1 697#endif 698 699#ifdef NET_SKBUFF_DATA_USES_OFFSET 700typedef unsigned int sk_buff_data_t; 701#else 702typedef unsigned char *sk_buff_data_t; 703#endif 704 705/** 706 * DOC: Basic sk_buff geometry 707 * 708 * struct sk_buff itself is a metadata structure and does not hold any packet 709 * data. All the data is held in associated buffers. 710 * 711 * &sk_buff.head points to the main "head" buffer. The head buffer is divided 712 * into two parts: 713 * 714 * - data buffer, containing headers and sometimes payload; 715 * this is the part of the skb operated on by the common helpers 716 * such as skb_put() or skb_pull(); 717 * - shared info (struct skb_shared_info) which holds an array of pointers 718 * to read-only data in the (page, offset, length) format. 719 * 720 * Optionally &skb_shared_info.frag_list may point to another skb. 721 * 722 * Basic diagram may look like this:: 723 * 724 * --------------- 725 * | sk_buff | 726 * --------------- 727 * ,--------------------------- + head 728 * / ,----------------- + data 729 * / / ,----------- + tail 730 * | | | , + end 731 * | | | | 732 * v v v v 733 * ----------------------------------------------- 734 * | headroom | data | tailroom | skb_shared_info | 735 * ----------------------------------------------- 736 * + [page frag] 737 * + [page frag] 738 * + [page frag] 739 * + [page frag] --------- 740 * + frag_list --> | sk_buff | 741 * --------- 742 * 743 */ 744 745/** 746 * struct sk_buff - socket buffer 747 * @next: Next buffer in list 748 * @prev: Previous buffer in list 749 * @tstamp: Time we arrived/left 750 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point 751 * for retransmit timer 752 * @rbnode: RB tree node, alternative to next/prev for netem/tcp 753 * @list: queue head 754 * @ll_node: anchor in an llist (eg socket defer_list) 755 * @sk: Socket we are owned by 756 * @dev: Device we arrived on/are leaving by 757 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL 758 * @cb: Control buffer. Free for use by every layer. Put private vars here 759 * @_skb_refdst: destination entry (with norefcount bit) 760 * @len: Length of actual data 761 * @data_len: Data length 762 * @mac_len: Length of link layer header 763 * @hdr_len: writable header length of cloned skb 764 * @csum: Checksum (must include start/offset pair) 765 * @csum_start: Offset from skb->head where checksumming should start 766 * @csum_offset: Offset from csum_start where checksum should be stored 767 * @priority: Packet queueing priority 768 * @ignore_df: allow local fragmentation 769 * @cloned: Head may be cloned (check refcnt to be sure) 770 * @ip_summed: Driver fed us an IP checksum 771 * @nohdr: Payload reference only, must not modify header 772 * @pkt_type: Packet class 773 * @fclone: skbuff clone status 774 * @ipvs_property: skbuff is owned by ipvs 775 * @inner_protocol_type: whether the inner protocol is 776 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO 777 * @remcsum_offload: remote checksum offload is enabled 778 * @offload_fwd_mark: Packet was L2-forwarded in hardware 779 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware 780 * @tc_skip_classify: do not classify packet. set by IFB device 781 * @tc_at_ingress: used within tc_classify to distinguish in/egress 782 * @redirected: packet was redirected by packet classifier 783 * @from_ingress: packet was redirected from the ingress path 784 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h 785 * @peeked: this packet has been seen already, so stats have been 786 * done for it, don't do them again 787 * @nf_trace: netfilter packet trace flag 788 * @protocol: Packet protocol from driver 789 * @destructor: Destruct function 790 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue) 791 * @_sk_redir: socket redirection information for skmsg 792 * @_nfct: Associated connection, if any (with nfctinfo bits) 793 * @skb_iif: ifindex of device we arrived on 794 * @tc_index: Traffic control index 795 * @hash: the packet hash 796 * @queue_mapping: Queue mapping for multiqueue devices 797 * @head_frag: skb was allocated from page fragments, 798 * not allocated by kmalloc() or vmalloc(). 799 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves 800 * @pp_recycle: mark the packet for recycling instead of freeing (implies 801 * page_pool support on driver) 802 * @active_extensions: active extensions (skb_ext_id types) 803 * @ndisc_nodetype: router type (from link layer) 804 * @ooo_okay: allow the mapping of a socket to a queue to be changed 805 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport 806 * ports. 807 * @sw_hash: indicates hash was computed in software stack 808 * @wifi_acked_valid: wifi_acked was set 809 * @wifi_acked: whether frame was acked on wifi or not 810 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 811 * @encapsulation: indicates the inner headers in the skbuff are valid 812 * @encap_hdr_csum: software checksum is needed 813 * @csum_valid: checksum is already valid 814 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL 815 * @csum_complete_sw: checksum was completed by software 816 * @csum_level: indicates the number of consecutive checksums found in 817 * the packet minus one that have been verified as 818 * CHECKSUM_UNNECESSARY (max 3) 819 * @dst_pending_confirm: need to confirm neighbour 820 * @decrypted: Decrypted SKB 821 * @slow_gro: state present at GRO time, slower prepare step required 822 * @mono_delivery_time: When set, skb->tstamp has the 823 * delivery_time in mono clock base (i.e. EDT). Otherwise, the 824 * skb->tstamp has the (rcv) timestamp at ingress and 825 * delivery_time at egress. 826 * @napi_id: id of the NAPI struct this skb came from 827 * @sender_cpu: (aka @napi_id) source CPU in XPS 828 * @alloc_cpu: CPU which did the skb allocation. 829 * @secmark: security marking 830 * @mark: Generic packet mark 831 * @reserved_tailroom: (aka @mark) number of bytes of free space available 832 * at the tail of an sk_buff 833 * @vlan_all: vlan fields (proto & tci) 834 * @vlan_proto: vlan encapsulation protocol 835 * @vlan_tci: vlan tag control information 836 * @inner_protocol: Protocol (encapsulation) 837 * @inner_ipproto: (aka @inner_protocol) stores ipproto when 838 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO; 839 * @inner_transport_header: Inner transport layer header (encapsulation) 840 * @inner_network_header: Network layer header (encapsulation) 841 * @inner_mac_header: Link layer header (encapsulation) 842 * @transport_header: Transport layer header 843 * @network_header: Network layer header 844 * @mac_header: Link layer header 845 * @kcov_handle: KCOV remote handle for remote coverage collection 846 * @tail: Tail pointer 847 * @end: End pointer 848 * @head: Head of buffer 849 * @data: Data head pointer 850 * @truesize: Buffer size 851 * @users: User count - see {datagram,tcp}.c 852 * @extensions: allocated extensions, valid if active_extensions is nonzero 853 */ 854 855struct sk_buff { 856 union { 857 struct { 858 /* These two members must be first to match sk_buff_head. */ 859 struct sk_buff *next; 860 struct sk_buff *prev; 861 862 union { 863 struct net_device *dev; 864 /* Some protocols might use this space to store information, 865 * while device pointer would be NULL. 866 * UDP receive path is one user. 867 */ 868 unsigned long dev_scratch; 869 }; 870 }; 871 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */ 872 struct list_head list; 873 struct llist_node ll_node; 874 }; 875 876 struct sock *sk; 877 878 union { 879 ktime_t tstamp; 880 u64 skb_mstamp_ns; /* earliest departure time */ 881 }; 882 /* 883 * This is the control buffer. It is free to use for every 884 * layer. Please put your private variables there. If you 885 * want to keep them across layers you have to do a skb_clone() 886 * first. This is owned by whoever has the skb queued ATM. 887 */ 888 char cb[48] __aligned(8); 889 890 union { 891 struct { 892 unsigned long _skb_refdst; 893 void (*destructor)(struct sk_buff *skb); 894 }; 895 struct list_head tcp_tsorted_anchor; 896#ifdef CONFIG_NET_SOCK_MSG 897 unsigned long _sk_redir; 898#endif 899 }; 900 901#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 902 unsigned long _nfct; 903#endif 904 unsigned int len, 905 data_len; 906 __u16 mac_len, 907 hdr_len; 908 909 /* Following fields are _not_ copied in __copy_skb_header() 910 * Note that queue_mapping is here mostly to fill a hole. 911 */ 912 __u16 queue_mapping; 913 914/* if you move cloned around you also must adapt those constants */ 915#ifdef __BIG_ENDIAN_BITFIELD 916#define CLONED_MASK (1 << 7) 917#else 918#define CLONED_MASK 1 919#endif 920#define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset) 921 922 /* private: */ 923 __u8 __cloned_offset[0]; 924 /* public: */ 925 __u8 cloned:1, 926 nohdr:1, 927 fclone:2, 928 peeked:1, 929 head_frag:1, 930 pfmemalloc:1, 931 pp_recycle:1; /* page_pool recycle indicator */ 932#ifdef CONFIG_SKB_EXTENSIONS 933 __u8 active_extensions; 934#endif 935 936 /* Fields enclosed in headers group are copied 937 * using a single memcpy() in __copy_skb_header() 938 */ 939 struct_group(headers, 940 941 /* private: */ 942 __u8 __pkt_type_offset[0]; 943 /* public: */ 944 __u8 pkt_type:3; /* see PKT_TYPE_MAX */ 945 __u8 ignore_df:1; 946 __u8 dst_pending_confirm:1; 947 __u8 ip_summed:2; 948 __u8 ooo_okay:1; 949 950 /* private: */ 951 __u8 __mono_tc_offset[0]; 952 /* public: */ 953 __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */ 954#ifdef CONFIG_NET_XGRESS 955 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */ 956 __u8 tc_skip_classify:1; 957#endif 958 __u8 remcsum_offload:1; 959 __u8 csum_complete_sw:1; 960 __u8 csum_level:2; 961 __u8 inner_protocol_type:1; 962 963 __u8 l4_hash:1; 964 __u8 sw_hash:1; 965#ifdef CONFIG_WIRELESS 966 __u8 wifi_acked_valid:1; 967 __u8 wifi_acked:1; 968#endif 969 __u8 no_fcs:1; 970 /* Indicates the inner headers are valid in the skbuff. */ 971 __u8 encapsulation:1; 972 __u8 encap_hdr_csum:1; 973 __u8 csum_valid:1; 974#ifdef CONFIG_IPV6_NDISC_NODETYPE 975 __u8 ndisc_nodetype:2; 976#endif 977 978#if IS_ENABLED(CONFIG_IP_VS) 979 __u8 ipvs_property:1; 980#endif 981#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 982 __u8 nf_trace:1; 983#endif 984#ifdef CONFIG_NET_SWITCHDEV 985 __u8 offload_fwd_mark:1; 986 __u8 offload_l3_fwd_mark:1; 987#endif 988 __u8 redirected:1; 989#ifdef CONFIG_NET_REDIRECT 990 __u8 from_ingress:1; 991#endif 992#ifdef CONFIG_NETFILTER_SKIP_EGRESS 993 __u8 nf_skip_egress:1; 994#endif 995#ifdef CONFIG_TLS_DEVICE 996 __u8 decrypted:1; 997#endif 998 __u8 slow_gro:1; 999#if IS_ENABLED(CONFIG_IP_SCTP) 1000 __u8 csum_not_inet:1; 1001#endif 1002 1003#if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS) 1004 __u16 tc_index; /* traffic control index */ 1005#endif 1006 1007 u16 alloc_cpu; 1008 1009 union { 1010 __wsum csum; 1011 struct { 1012 __u16 csum_start; 1013 __u16 csum_offset; 1014 }; 1015 }; 1016 __u32 priority; 1017 int skb_iif; 1018 __u32 hash; 1019 union { 1020 u32 vlan_all; 1021 struct { 1022 __be16 vlan_proto; 1023 __u16 vlan_tci; 1024 }; 1025 }; 1026#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS) 1027 union { 1028 unsigned int napi_id; 1029 unsigned int sender_cpu; 1030 }; 1031#endif 1032#ifdef CONFIG_NETWORK_SECMARK 1033 __u32 secmark; 1034#endif 1035 1036 union { 1037 __u32 mark; 1038 __u32 reserved_tailroom; 1039 }; 1040 1041 union { 1042 __be16 inner_protocol; 1043 __u8 inner_ipproto; 1044 }; 1045 1046 __u16 inner_transport_header; 1047 __u16 inner_network_header; 1048 __u16 inner_mac_header; 1049 1050 __be16 protocol; 1051 __u16 transport_header; 1052 __u16 network_header; 1053 __u16 mac_header; 1054 1055#ifdef CONFIG_KCOV 1056 u64 kcov_handle; 1057#endif 1058 1059 ); /* end headers group */ 1060 1061 /* These elements must be at the end, see alloc_skb() for details. */ 1062 sk_buff_data_t tail; 1063 sk_buff_data_t end; 1064 unsigned char *head, 1065 *data; 1066 unsigned int truesize; 1067 refcount_t users; 1068 1069#ifdef CONFIG_SKB_EXTENSIONS 1070 /* only usable after checking ->active_extensions != 0 */ 1071 struct skb_ext *extensions; 1072#endif 1073}; 1074 1075/* if you move pkt_type around you also must adapt those constants */ 1076#ifdef __BIG_ENDIAN_BITFIELD 1077#define PKT_TYPE_MAX (7 << 5) 1078#else 1079#define PKT_TYPE_MAX 7 1080#endif 1081#define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset) 1082 1083/* if you move tc_at_ingress or mono_delivery_time 1084 * around, you also must adapt these constants. 1085 */ 1086#ifdef __BIG_ENDIAN_BITFIELD 1087#define SKB_MONO_DELIVERY_TIME_MASK (1 << 7) 1088#define TC_AT_INGRESS_MASK (1 << 6) 1089#else 1090#define SKB_MONO_DELIVERY_TIME_MASK (1 << 0) 1091#define TC_AT_INGRESS_MASK (1 << 1) 1092#endif 1093#define SKB_BF_MONO_TC_OFFSET offsetof(struct sk_buff, __mono_tc_offset) 1094 1095#ifdef __KERNEL__ 1096/* 1097 * Handling routines are only of interest to the kernel 1098 */ 1099 1100#define SKB_ALLOC_FCLONE 0x01 1101#define SKB_ALLOC_RX 0x02 1102#define SKB_ALLOC_NAPI 0x04 1103 1104/** 1105 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves 1106 * @skb: buffer 1107 */ 1108static inline bool skb_pfmemalloc(const struct sk_buff *skb) 1109{ 1110 return unlikely(skb->pfmemalloc); 1111} 1112 1113/* 1114 * skb might have a dst pointer attached, refcounted or not. 1115 * _skb_refdst low order bit is set if refcount was _not_ taken 1116 */ 1117#define SKB_DST_NOREF 1UL 1118#define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 1119 1120/** 1121 * skb_dst - returns skb dst_entry 1122 * @skb: buffer 1123 * 1124 * Returns skb dst_entry, regardless of reference taken or not. 1125 */ 1126static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 1127{ 1128 /* If refdst was not refcounted, check we still are in a 1129 * rcu_read_lock section 1130 */ 1131 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 1132 !rcu_read_lock_held() && 1133 !rcu_read_lock_bh_held()); 1134 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 1135} 1136 1137/** 1138 * skb_dst_set - sets skb dst 1139 * @skb: buffer 1140 * @dst: dst entry 1141 * 1142 * Sets skb dst, assuming a reference was taken on dst and should 1143 * be released by skb_dst_drop() 1144 */ 1145static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 1146{ 1147 skb->slow_gro |= !!dst; 1148 skb->_skb_refdst = (unsigned long)dst; 1149} 1150 1151/** 1152 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 1153 * @skb: buffer 1154 * @dst: dst entry 1155 * 1156 * Sets skb dst, assuming a reference was not taken on dst. 1157 * If dst entry is cached, we do not take reference and dst_release 1158 * will be avoided by refdst_drop. If dst entry is not cached, we take 1159 * reference, so that last dst_release can destroy the dst immediately. 1160 */ 1161static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 1162{ 1163 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 1164 skb->slow_gro |= !!dst; 1165 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 1166} 1167 1168/** 1169 * skb_dst_is_noref - Test if skb dst isn't refcounted 1170 * @skb: buffer 1171 */ 1172static inline bool skb_dst_is_noref(const struct sk_buff *skb) 1173{ 1174 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 1175} 1176 1177/** 1178 * skb_rtable - Returns the skb &rtable 1179 * @skb: buffer 1180 */ 1181static inline struct rtable *skb_rtable(const struct sk_buff *skb) 1182{ 1183 return (struct rtable *)skb_dst(skb); 1184} 1185 1186/* For mangling skb->pkt_type from user space side from applications 1187 * such as nft, tc, etc, we only allow a conservative subset of 1188 * possible pkt_types to be set. 1189*/ 1190static inline bool skb_pkt_type_ok(u32 ptype) 1191{ 1192 return ptype <= PACKET_OTHERHOST; 1193} 1194 1195/** 1196 * skb_napi_id - Returns the skb's NAPI id 1197 * @skb: buffer 1198 */ 1199static inline unsigned int skb_napi_id(const struct sk_buff *skb) 1200{ 1201#ifdef CONFIG_NET_RX_BUSY_POLL 1202 return skb->napi_id; 1203#else 1204 return 0; 1205#endif 1206} 1207 1208static inline bool skb_wifi_acked_valid(const struct sk_buff *skb) 1209{ 1210#ifdef CONFIG_WIRELESS 1211 return skb->wifi_acked_valid; 1212#else 1213 return 0; 1214#endif 1215} 1216 1217/** 1218 * skb_unref - decrement the skb's reference count 1219 * @skb: buffer 1220 * 1221 * Returns true if we can free the skb. 1222 */ 1223static inline bool skb_unref(struct sk_buff *skb) 1224{ 1225 if (unlikely(!skb)) 1226 return false; 1227 if (likely(refcount_read(&skb->users) == 1)) 1228 smp_rmb(); 1229 else if (likely(!refcount_dec_and_test(&skb->users))) 1230 return false; 1231 1232 return true; 1233} 1234 1235static inline bool skb_data_unref(const struct sk_buff *skb, 1236 struct skb_shared_info *shinfo) 1237{ 1238 int bias; 1239 1240 if (!skb->cloned) 1241 return true; 1242 1243 bias = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1; 1244 1245 if (atomic_read(&shinfo->dataref) == bias) 1246 smp_rmb(); 1247 else if (atomic_sub_return(bias, &shinfo->dataref)) 1248 return false; 1249 1250 return true; 1251} 1252 1253void __fix_address 1254kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason); 1255 1256/** 1257 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason 1258 * @skb: buffer to free 1259 */ 1260static inline void kfree_skb(struct sk_buff *skb) 1261{ 1262 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED); 1263} 1264 1265void skb_release_head_state(struct sk_buff *skb); 1266void kfree_skb_list_reason(struct sk_buff *segs, 1267 enum skb_drop_reason reason); 1268void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt); 1269void skb_tx_error(struct sk_buff *skb); 1270 1271static inline void kfree_skb_list(struct sk_buff *segs) 1272{ 1273 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED); 1274} 1275 1276#ifdef CONFIG_TRACEPOINTS 1277void consume_skb(struct sk_buff *skb); 1278#else 1279static inline void consume_skb(struct sk_buff *skb) 1280{ 1281 return kfree_skb(skb); 1282} 1283#endif 1284 1285void __consume_stateless_skb(struct sk_buff *skb); 1286void __kfree_skb(struct sk_buff *skb); 1287 1288void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 1289bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 1290 bool *fragstolen, int *delta_truesize); 1291 1292struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 1293 int node); 1294struct sk_buff *__build_skb(void *data, unsigned int frag_size); 1295struct sk_buff *build_skb(void *data, unsigned int frag_size); 1296struct sk_buff *build_skb_around(struct sk_buff *skb, 1297 void *data, unsigned int frag_size); 1298void skb_attempt_defer_free(struct sk_buff *skb); 1299 1300struct sk_buff *napi_build_skb(void *data, unsigned int frag_size); 1301struct sk_buff *slab_build_skb(void *data); 1302 1303/** 1304 * alloc_skb - allocate a network buffer 1305 * @size: size to allocate 1306 * @priority: allocation mask 1307 * 1308 * This function is a convenient wrapper around __alloc_skb(). 1309 */ 1310static inline struct sk_buff *alloc_skb(unsigned int size, 1311 gfp_t priority) 1312{ 1313 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 1314} 1315 1316struct sk_buff *alloc_skb_with_frags(unsigned long header_len, 1317 unsigned long data_len, 1318 int max_page_order, 1319 int *errcode, 1320 gfp_t gfp_mask); 1321struct sk_buff *alloc_skb_for_msg(struct sk_buff *first); 1322 1323/* Layout of fast clones : [skb1][skb2][fclone_ref] */ 1324struct sk_buff_fclones { 1325 struct sk_buff skb1; 1326 1327 struct sk_buff skb2; 1328 1329 refcount_t fclone_ref; 1330}; 1331 1332/** 1333 * skb_fclone_busy - check if fclone is busy 1334 * @sk: socket 1335 * @skb: buffer 1336 * 1337 * Returns true if skb is a fast clone, and its clone is not freed. 1338 * Some drivers call skb_orphan() in their ndo_start_xmit(), 1339 * so we also check that didn't happen. 1340 */ 1341static inline bool skb_fclone_busy(const struct sock *sk, 1342 const struct sk_buff *skb) 1343{ 1344 const struct sk_buff_fclones *fclones; 1345 1346 fclones = container_of(skb, struct sk_buff_fclones, skb1); 1347 1348 return skb->fclone == SKB_FCLONE_ORIG && 1349 refcount_read(&fclones->fclone_ref) > 1 && 1350 READ_ONCE(fclones->skb2.sk) == sk; 1351} 1352 1353/** 1354 * alloc_skb_fclone - allocate a network buffer from fclone cache 1355 * @size: size to allocate 1356 * @priority: allocation mask 1357 * 1358 * This function is a convenient wrapper around __alloc_skb(). 1359 */ 1360static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 1361 gfp_t priority) 1362{ 1363 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 1364} 1365 1366struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 1367void skb_headers_offset_update(struct sk_buff *skb, int off); 1368int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 1369struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 1370void skb_copy_header(struct sk_buff *new, const struct sk_buff *old); 1371struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 1372struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, 1373 gfp_t gfp_mask, bool fclone); 1374static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, 1375 gfp_t gfp_mask) 1376{ 1377 return __pskb_copy_fclone(skb, headroom, gfp_mask, false); 1378} 1379 1380int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 1381struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 1382 unsigned int headroom); 1383struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom); 1384struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 1385 int newtailroom, gfp_t priority); 1386int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, 1387 int offset, int len); 1388int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, 1389 int offset, int len); 1390int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 1391int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error); 1392 1393/** 1394 * skb_pad - zero pad the tail of an skb 1395 * @skb: buffer to pad 1396 * @pad: space to pad 1397 * 1398 * Ensure that a buffer is followed by a padding area that is zero 1399 * filled. Used by network drivers which may DMA or transfer data 1400 * beyond the buffer end onto the wire. 1401 * 1402 * May return error in out of memory cases. The skb is freed on error. 1403 */ 1404static inline int skb_pad(struct sk_buff *skb, int pad) 1405{ 1406 return __skb_pad(skb, pad, true); 1407} 1408#define dev_kfree_skb(a) consume_skb(a) 1409 1410int skb_append_pagefrags(struct sk_buff *skb, struct page *page, 1411 int offset, size_t size, size_t max_frags); 1412 1413struct skb_seq_state { 1414 __u32 lower_offset; 1415 __u32 upper_offset; 1416 __u32 frag_idx; 1417 __u32 stepped_offset; 1418 struct sk_buff *root_skb; 1419 struct sk_buff *cur_skb; 1420 __u8 *frag_data; 1421 __u32 frag_off; 1422}; 1423 1424void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 1425 unsigned int to, struct skb_seq_state *st); 1426unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 1427 struct skb_seq_state *st); 1428void skb_abort_seq_read(struct skb_seq_state *st); 1429 1430unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 1431 unsigned int to, struct ts_config *config); 1432 1433/* 1434 * Packet hash types specify the type of hash in skb_set_hash. 1435 * 1436 * Hash types refer to the protocol layer addresses which are used to 1437 * construct a packet's hash. The hashes are used to differentiate or identify 1438 * flows of the protocol layer for the hash type. Hash types are either 1439 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 1440 * 1441 * Properties of hashes: 1442 * 1443 * 1) Two packets in different flows have different hash values 1444 * 2) Two packets in the same flow should have the same hash value 1445 * 1446 * A hash at a higher layer is considered to be more specific. A driver should 1447 * set the most specific hash possible. 1448 * 1449 * A driver cannot indicate a more specific hash than the layer at which a hash 1450 * was computed. For instance an L3 hash cannot be set as an L4 hash. 1451 * 1452 * A driver may indicate a hash level which is less specific than the 1453 * actual layer the hash was computed on. For instance, a hash computed 1454 * at L4 may be considered an L3 hash. This should only be done if the 1455 * driver can't unambiguously determine that the HW computed the hash at 1456 * the higher layer. Note that the "should" in the second property above 1457 * permits this. 1458 */ 1459enum pkt_hash_types { 1460 PKT_HASH_TYPE_NONE, /* Undefined type */ 1461 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 1462 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 1463 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 1464}; 1465 1466static inline void skb_clear_hash(struct sk_buff *skb) 1467{ 1468 skb->hash = 0; 1469 skb->sw_hash = 0; 1470 skb->l4_hash = 0; 1471} 1472 1473static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 1474{ 1475 if (!skb->l4_hash) 1476 skb_clear_hash(skb); 1477} 1478 1479static inline void 1480__skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4) 1481{ 1482 skb->l4_hash = is_l4; 1483 skb->sw_hash = is_sw; 1484 skb->hash = hash; 1485} 1486 1487static inline void 1488skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 1489{ 1490 /* Used by drivers to set hash from HW */ 1491 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4); 1492} 1493 1494static inline void 1495__skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4) 1496{ 1497 __skb_set_hash(skb, hash, true, is_l4); 1498} 1499 1500void __skb_get_hash(struct sk_buff *skb); 1501u32 __skb_get_hash_symmetric(const struct sk_buff *skb); 1502u32 skb_get_poff(const struct sk_buff *skb); 1503u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1504 const struct flow_keys_basic *keys, int hlen); 1505__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 1506 const void *data, int hlen_proto); 1507 1508static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, 1509 int thoff, u8 ip_proto) 1510{ 1511 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0); 1512} 1513 1514void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 1515 const struct flow_dissector_key *key, 1516 unsigned int key_count); 1517 1518struct bpf_flow_dissector; 1519u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 1520 __be16 proto, int nhoff, int hlen, unsigned int flags); 1521 1522bool __skb_flow_dissect(const struct net *net, 1523 const struct sk_buff *skb, 1524 struct flow_dissector *flow_dissector, 1525 void *target_container, const void *data, 1526 __be16 proto, int nhoff, int hlen, unsigned int flags); 1527 1528static inline bool skb_flow_dissect(const struct sk_buff *skb, 1529 struct flow_dissector *flow_dissector, 1530 void *target_container, unsigned int flags) 1531{ 1532 return __skb_flow_dissect(NULL, skb, flow_dissector, 1533 target_container, NULL, 0, 0, 0, flags); 1534} 1535 1536static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb, 1537 struct flow_keys *flow, 1538 unsigned int flags) 1539{ 1540 memset(flow, 0, sizeof(*flow)); 1541 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector, 1542 flow, NULL, 0, 0, 0, flags); 1543} 1544 1545static inline bool 1546skb_flow_dissect_flow_keys_basic(const struct net *net, 1547 const struct sk_buff *skb, 1548 struct flow_keys_basic *flow, 1549 const void *data, __be16 proto, 1550 int nhoff, int hlen, unsigned int flags) 1551{ 1552 memset(flow, 0, sizeof(*flow)); 1553 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow, 1554 data, proto, nhoff, hlen, flags); 1555} 1556 1557void skb_flow_dissect_meta(const struct sk_buff *skb, 1558 struct flow_dissector *flow_dissector, 1559 void *target_container); 1560 1561/* Gets a skb connection tracking info, ctinfo map should be a 1562 * map of mapsize to translate enum ip_conntrack_info states 1563 * to user states. 1564 */ 1565void 1566skb_flow_dissect_ct(const struct sk_buff *skb, 1567 struct flow_dissector *flow_dissector, 1568 void *target_container, 1569 u16 *ctinfo_map, size_t mapsize, 1570 bool post_ct, u16 zone); 1571void 1572skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 1573 struct flow_dissector *flow_dissector, 1574 void *target_container); 1575 1576void skb_flow_dissect_hash(const struct sk_buff *skb, 1577 struct flow_dissector *flow_dissector, 1578 void *target_container); 1579 1580static inline __u32 skb_get_hash(struct sk_buff *skb) 1581{ 1582 if (!skb->l4_hash && !skb->sw_hash) 1583 __skb_get_hash(skb); 1584 1585 return skb->hash; 1586} 1587 1588static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 1589{ 1590 if (!skb->l4_hash && !skb->sw_hash) { 1591 struct flow_keys keys; 1592 __u32 hash = __get_hash_from_flowi6(fl6, &keys); 1593 1594 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1595 } 1596 1597 return skb->hash; 1598} 1599 1600__u32 skb_get_hash_perturb(const struct sk_buff *skb, 1601 const siphash_key_t *perturb); 1602 1603static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 1604{ 1605 return skb->hash; 1606} 1607 1608static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 1609{ 1610 to->hash = from->hash; 1611 to->sw_hash = from->sw_hash; 1612 to->l4_hash = from->l4_hash; 1613}; 1614 1615static inline int skb_cmp_decrypted(const struct sk_buff *skb1, 1616 const struct sk_buff *skb2) 1617{ 1618#ifdef CONFIG_TLS_DEVICE 1619 return skb2->decrypted - skb1->decrypted; 1620#else 1621 return 0; 1622#endif 1623} 1624 1625static inline void skb_copy_decrypted(struct sk_buff *to, 1626 const struct sk_buff *from) 1627{ 1628#ifdef CONFIG_TLS_DEVICE 1629 to->decrypted = from->decrypted; 1630#endif 1631} 1632 1633#ifdef NET_SKBUFF_DATA_USES_OFFSET 1634static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1635{ 1636 return skb->head + skb->end; 1637} 1638 1639static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1640{ 1641 return skb->end; 1642} 1643 1644static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1645{ 1646 skb->end = offset; 1647} 1648#else 1649static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1650{ 1651 return skb->end; 1652} 1653 1654static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1655{ 1656 return skb->end - skb->head; 1657} 1658 1659static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1660{ 1661 skb->end = skb->head + offset; 1662} 1663#endif 1664 1665struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, 1666 struct ubuf_info *uarg); 1667 1668void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); 1669 1670void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg, 1671 bool success); 1672 1673int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk, 1674 struct sk_buff *skb, struct iov_iter *from, 1675 size_t length); 1676 1677static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, 1678 struct msghdr *msg, int len) 1679{ 1680 return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len); 1681} 1682 1683int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, 1684 struct msghdr *msg, int len, 1685 struct ubuf_info *uarg); 1686 1687/* Internal */ 1688#define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 1689 1690static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 1691{ 1692 return &skb_shinfo(skb)->hwtstamps; 1693} 1694 1695static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb) 1696{ 1697 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE; 1698 1699 return is_zcopy ? skb_uarg(skb) : NULL; 1700} 1701 1702static inline bool skb_zcopy_pure(const struct sk_buff *skb) 1703{ 1704 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY; 1705} 1706 1707static inline bool skb_zcopy_managed(const struct sk_buff *skb) 1708{ 1709 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS; 1710} 1711 1712static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1, 1713 const struct sk_buff *skb2) 1714{ 1715 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2); 1716} 1717 1718static inline void net_zcopy_get(struct ubuf_info *uarg) 1719{ 1720 refcount_inc(&uarg->refcnt); 1721} 1722 1723static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg) 1724{ 1725 skb_shinfo(skb)->destructor_arg = uarg; 1726 skb_shinfo(skb)->flags |= uarg->flags; 1727} 1728 1729static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, 1730 bool *have_ref) 1731{ 1732 if (skb && uarg && !skb_zcopy(skb)) { 1733 if (unlikely(have_ref && *have_ref)) 1734 *have_ref = false; 1735 else 1736 net_zcopy_get(uarg); 1737 skb_zcopy_init(skb, uarg); 1738 } 1739} 1740 1741static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val) 1742{ 1743 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL); 1744 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG; 1745} 1746 1747static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb) 1748{ 1749 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL; 1750} 1751 1752static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb) 1753{ 1754 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL); 1755} 1756 1757static inline void net_zcopy_put(struct ubuf_info *uarg) 1758{ 1759 if (uarg) 1760 uarg->callback(NULL, uarg, true); 1761} 1762 1763static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref) 1764{ 1765 if (uarg) { 1766 if (uarg->callback == msg_zerocopy_callback) 1767 msg_zerocopy_put_abort(uarg, have_uref); 1768 else if (have_uref) 1769 net_zcopy_put(uarg); 1770 } 1771} 1772 1773/* Release a reference on a zerocopy structure */ 1774static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success) 1775{ 1776 struct ubuf_info *uarg = skb_zcopy(skb); 1777 1778 if (uarg) { 1779 if (!skb_zcopy_is_nouarg(skb)) 1780 uarg->callback(skb, uarg, zerocopy_success); 1781 1782 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY; 1783 } 1784} 1785 1786void __skb_zcopy_downgrade_managed(struct sk_buff *skb); 1787 1788static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb) 1789{ 1790 if (unlikely(skb_zcopy_managed(skb))) 1791 __skb_zcopy_downgrade_managed(skb); 1792} 1793 1794static inline void skb_mark_not_on_list(struct sk_buff *skb) 1795{ 1796 skb->next = NULL; 1797} 1798 1799static inline void skb_poison_list(struct sk_buff *skb) 1800{ 1801#ifdef CONFIG_DEBUG_NET 1802 skb->next = SKB_LIST_POISON_NEXT; 1803#endif 1804} 1805 1806/* Iterate through singly-linked GSO fragments of an skb. */ 1807#define skb_list_walk_safe(first, skb, next_skb) \ 1808 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \ 1809 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL) 1810 1811static inline void skb_list_del_init(struct sk_buff *skb) 1812{ 1813 __list_del_entry(&skb->list); 1814 skb_mark_not_on_list(skb); 1815} 1816 1817/** 1818 * skb_queue_empty - check if a queue is empty 1819 * @list: queue head 1820 * 1821 * Returns true if the queue is empty, false otherwise. 1822 */ 1823static inline int skb_queue_empty(const struct sk_buff_head *list) 1824{ 1825 return list->next == (const struct sk_buff *) list; 1826} 1827 1828/** 1829 * skb_queue_empty_lockless - check if a queue is empty 1830 * @list: queue head 1831 * 1832 * Returns true if the queue is empty, false otherwise. 1833 * This variant can be used in lockless contexts. 1834 */ 1835static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list) 1836{ 1837 return READ_ONCE(list->next) == (const struct sk_buff *) list; 1838} 1839 1840 1841/** 1842 * skb_queue_is_last - check if skb is the last entry in the queue 1843 * @list: queue head 1844 * @skb: buffer 1845 * 1846 * Returns true if @skb is the last buffer on the list. 1847 */ 1848static inline bool skb_queue_is_last(const struct sk_buff_head *list, 1849 const struct sk_buff *skb) 1850{ 1851 return skb->next == (const struct sk_buff *) list; 1852} 1853 1854/** 1855 * skb_queue_is_first - check if skb is the first entry in the queue 1856 * @list: queue head 1857 * @skb: buffer 1858 * 1859 * Returns true if @skb is the first buffer on the list. 1860 */ 1861static inline bool skb_queue_is_first(const struct sk_buff_head *list, 1862 const struct sk_buff *skb) 1863{ 1864 return skb->prev == (const struct sk_buff *) list; 1865} 1866 1867/** 1868 * skb_queue_next - return the next packet in the queue 1869 * @list: queue head 1870 * @skb: current buffer 1871 * 1872 * Return the next packet in @list after @skb. It is only valid to 1873 * call this if skb_queue_is_last() evaluates to false. 1874 */ 1875static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 1876 const struct sk_buff *skb) 1877{ 1878 /* This BUG_ON may seem severe, but if we just return then we 1879 * are going to dereference garbage. 1880 */ 1881 BUG_ON(skb_queue_is_last(list, skb)); 1882 return skb->next; 1883} 1884 1885/** 1886 * skb_queue_prev - return the prev packet in the queue 1887 * @list: queue head 1888 * @skb: current buffer 1889 * 1890 * Return the prev packet in @list before @skb. It is only valid to 1891 * call this if skb_queue_is_first() evaluates to false. 1892 */ 1893static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 1894 const struct sk_buff *skb) 1895{ 1896 /* This BUG_ON may seem severe, but if we just return then we 1897 * are going to dereference garbage. 1898 */ 1899 BUG_ON(skb_queue_is_first(list, skb)); 1900 return skb->prev; 1901} 1902 1903/** 1904 * skb_get - reference buffer 1905 * @skb: buffer to reference 1906 * 1907 * Makes another reference to a socket buffer and returns a pointer 1908 * to the buffer. 1909 */ 1910static inline struct sk_buff *skb_get(struct sk_buff *skb) 1911{ 1912 refcount_inc(&skb->users); 1913 return skb; 1914} 1915 1916/* 1917 * If users == 1, we are the only owner and can avoid redundant atomic changes. 1918 */ 1919 1920/** 1921 * skb_cloned - is the buffer a clone 1922 * @skb: buffer to check 1923 * 1924 * Returns true if the buffer was generated with skb_clone() and is 1925 * one of multiple shared copies of the buffer. Cloned buffers are 1926 * shared data so must not be written to under normal circumstances. 1927 */ 1928static inline int skb_cloned(const struct sk_buff *skb) 1929{ 1930 return skb->cloned && 1931 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 1932} 1933 1934static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 1935{ 1936 might_sleep_if(gfpflags_allow_blocking(pri)); 1937 1938 if (skb_cloned(skb)) 1939 return pskb_expand_head(skb, 0, 0, pri); 1940 1941 return 0; 1942} 1943 1944/* This variant of skb_unclone() makes sure skb->truesize 1945 * and skb_end_offset() are not changed, whenever a new skb->head is needed. 1946 * 1947 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X)) 1948 * when various debugging features are in place. 1949 */ 1950int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri); 1951static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri) 1952{ 1953 might_sleep_if(gfpflags_allow_blocking(pri)); 1954 1955 if (skb_cloned(skb)) 1956 return __skb_unclone_keeptruesize(skb, pri); 1957 return 0; 1958} 1959 1960/** 1961 * skb_header_cloned - is the header a clone 1962 * @skb: buffer to check 1963 * 1964 * Returns true if modifying the header part of the buffer requires 1965 * the data to be copied. 1966 */ 1967static inline int skb_header_cloned(const struct sk_buff *skb) 1968{ 1969 int dataref; 1970 1971 if (!skb->cloned) 1972 return 0; 1973 1974 dataref = atomic_read(&skb_shinfo(skb)->dataref); 1975 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 1976 return dataref != 1; 1977} 1978 1979static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri) 1980{ 1981 might_sleep_if(gfpflags_allow_blocking(pri)); 1982 1983 if (skb_header_cloned(skb)) 1984 return pskb_expand_head(skb, 0, 0, pri); 1985 1986 return 0; 1987} 1988 1989/** 1990 * __skb_header_release() - allow clones to use the headroom 1991 * @skb: buffer to operate on 1992 * 1993 * See "DOC: dataref and headerless skbs". 1994 */ 1995static inline void __skb_header_release(struct sk_buff *skb) 1996{ 1997 skb->nohdr = 1; 1998 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT)); 1999} 2000 2001 2002/** 2003 * skb_shared - is the buffer shared 2004 * @skb: buffer to check 2005 * 2006 * Returns true if more than one person has a reference to this 2007 * buffer. 2008 */ 2009static inline int skb_shared(const struct sk_buff *skb) 2010{ 2011 return refcount_read(&skb->users) != 1; 2012} 2013 2014/** 2015 * skb_share_check - check if buffer is shared and if so clone it 2016 * @skb: buffer to check 2017 * @pri: priority for memory allocation 2018 * 2019 * If the buffer is shared the buffer is cloned and the old copy 2020 * drops a reference. A new clone with a single reference is returned. 2021 * If the buffer is not shared the original buffer is returned. When 2022 * being called from interrupt status or with spinlocks held pri must 2023 * be GFP_ATOMIC. 2024 * 2025 * NULL is returned on a memory allocation failure. 2026 */ 2027static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 2028{ 2029 might_sleep_if(gfpflags_allow_blocking(pri)); 2030 if (skb_shared(skb)) { 2031 struct sk_buff *nskb = skb_clone(skb, pri); 2032 2033 if (likely(nskb)) 2034 consume_skb(skb); 2035 else 2036 kfree_skb(skb); 2037 skb = nskb; 2038 } 2039 return skb; 2040} 2041 2042/* 2043 * Copy shared buffers into a new sk_buff. We effectively do COW on 2044 * packets to handle cases where we have a local reader and forward 2045 * and a couple of other messy ones. The normal one is tcpdumping 2046 * a packet that's being forwarded. 2047 */ 2048 2049/** 2050 * skb_unshare - make a copy of a shared buffer 2051 * @skb: buffer to check 2052 * @pri: priority for memory allocation 2053 * 2054 * If the socket buffer is a clone then this function creates a new 2055 * copy of the data, drops a reference count on the old copy and returns 2056 * the new copy with the reference count at 1. If the buffer is not a clone 2057 * the original buffer is returned. When called with a spinlock held or 2058 * from interrupt state @pri must be %GFP_ATOMIC 2059 * 2060 * %NULL is returned on a memory allocation failure. 2061 */ 2062static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 2063 gfp_t pri) 2064{ 2065 might_sleep_if(gfpflags_allow_blocking(pri)); 2066 if (skb_cloned(skb)) { 2067 struct sk_buff *nskb = skb_copy(skb, pri); 2068 2069 /* Free our shared copy */ 2070 if (likely(nskb)) 2071 consume_skb(skb); 2072 else 2073 kfree_skb(skb); 2074 skb = nskb; 2075 } 2076 return skb; 2077} 2078 2079/** 2080 * skb_peek - peek at the head of an &sk_buff_head 2081 * @list_: list to peek at 2082 * 2083 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2084 * be careful with this one. A peek leaves the buffer on the 2085 * list and someone else may run off with it. You must hold 2086 * the appropriate locks or have a private queue to do this. 2087 * 2088 * Returns %NULL for an empty list or a pointer to the head element. 2089 * The reference count is not incremented and the reference is therefore 2090 * volatile. Use with caution. 2091 */ 2092static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 2093{ 2094 struct sk_buff *skb = list_->next; 2095 2096 if (skb == (struct sk_buff *)list_) 2097 skb = NULL; 2098 return skb; 2099} 2100 2101/** 2102 * __skb_peek - peek at the head of a non-empty &sk_buff_head 2103 * @list_: list to peek at 2104 * 2105 * Like skb_peek(), but the caller knows that the list is not empty. 2106 */ 2107static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_) 2108{ 2109 return list_->next; 2110} 2111 2112/** 2113 * skb_peek_next - peek skb following the given one from a queue 2114 * @skb: skb to start from 2115 * @list_: list to peek at 2116 * 2117 * Returns %NULL when the end of the list is met or a pointer to the 2118 * next element. The reference count is not incremented and the 2119 * reference is therefore volatile. Use with caution. 2120 */ 2121static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 2122 const struct sk_buff_head *list_) 2123{ 2124 struct sk_buff *next = skb->next; 2125 2126 if (next == (struct sk_buff *)list_) 2127 next = NULL; 2128 return next; 2129} 2130 2131/** 2132 * skb_peek_tail - peek at the tail of an &sk_buff_head 2133 * @list_: list to peek at 2134 * 2135 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2136 * be careful with this one. A peek leaves the buffer on the 2137 * list and someone else may run off with it. You must hold 2138 * the appropriate locks or have a private queue to do this. 2139 * 2140 * Returns %NULL for an empty list or a pointer to the tail element. 2141 * The reference count is not incremented and the reference is therefore 2142 * volatile. Use with caution. 2143 */ 2144static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 2145{ 2146 struct sk_buff *skb = READ_ONCE(list_->prev); 2147 2148 if (skb == (struct sk_buff *)list_) 2149 skb = NULL; 2150 return skb; 2151 2152} 2153 2154/** 2155 * skb_queue_len - get queue length 2156 * @list_: list to measure 2157 * 2158 * Return the length of an &sk_buff queue. 2159 */ 2160static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 2161{ 2162 return list_->qlen; 2163} 2164 2165/** 2166 * skb_queue_len_lockless - get queue length 2167 * @list_: list to measure 2168 * 2169 * Return the length of an &sk_buff queue. 2170 * This variant can be used in lockless contexts. 2171 */ 2172static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_) 2173{ 2174 return READ_ONCE(list_->qlen); 2175} 2176 2177/** 2178 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 2179 * @list: queue to initialize 2180 * 2181 * This initializes only the list and queue length aspects of 2182 * an sk_buff_head object. This allows to initialize the list 2183 * aspects of an sk_buff_head without reinitializing things like 2184 * the spinlock. It can also be used for on-stack sk_buff_head 2185 * objects where the spinlock is known to not be used. 2186 */ 2187static inline void __skb_queue_head_init(struct sk_buff_head *list) 2188{ 2189 list->prev = list->next = (struct sk_buff *)list; 2190 list->qlen = 0; 2191} 2192 2193/* 2194 * This function creates a split out lock class for each invocation; 2195 * this is needed for now since a whole lot of users of the skb-queue 2196 * infrastructure in drivers have different locking usage (in hardirq) 2197 * than the networking core (in softirq only). In the long run either the 2198 * network layer or drivers should need annotation to consolidate the 2199 * main types of usage into 3 classes. 2200 */ 2201static inline void skb_queue_head_init(struct sk_buff_head *list) 2202{ 2203 spin_lock_init(&list->lock); 2204 __skb_queue_head_init(list); 2205} 2206 2207static inline void skb_queue_head_init_class(struct sk_buff_head *list, 2208 struct lock_class_key *class) 2209{ 2210 skb_queue_head_init(list); 2211 lockdep_set_class(&list->lock, class); 2212} 2213 2214/* 2215 * Insert an sk_buff on a list. 2216 * 2217 * The "__skb_xxxx()" functions are the non-atomic ones that 2218 * can only be called with interrupts disabled. 2219 */ 2220static inline void __skb_insert(struct sk_buff *newsk, 2221 struct sk_buff *prev, struct sk_buff *next, 2222 struct sk_buff_head *list) 2223{ 2224 /* See skb_queue_empty_lockless() and skb_peek_tail() 2225 * for the opposite READ_ONCE() 2226 */ 2227 WRITE_ONCE(newsk->next, next); 2228 WRITE_ONCE(newsk->prev, prev); 2229 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk); 2230 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk); 2231 WRITE_ONCE(list->qlen, list->qlen + 1); 2232} 2233 2234static inline void __skb_queue_splice(const struct sk_buff_head *list, 2235 struct sk_buff *prev, 2236 struct sk_buff *next) 2237{ 2238 struct sk_buff *first = list->next; 2239 struct sk_buff *last = list->prev; 2240 2241 WRITE_ONCE(first->prev, prev); 2242 WRITE_ONCE(prev->next, first); 2243 2244 WRITE_ONCE(last->next, next); 2245 WRITE_ONCE(next->prev, last); 2246} 2247 2248/** 2249 * skb_queue_splice - join two skb lists, this is designed for stacks 2250 * @list: the new list to add 2251 * @head: the place to add it in the first list 2252 */ 2253static inline void skb_queue_splice(const struct sk_buff_head *list, 2254 struct sk_buff_head *head) 2255{ 2256 if (!skb_queue_empty(list)) { 2257 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2258 head->qlen += list->qlen; 2259 } 2260} 2261 2262/** 2263 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 2264 * @list: the new list to add 2265 * @head: the place to add it in the first list 2266 * 2267 * The list at @list is reinitialised 2268 */ 2269static inline void skb_queue_splice_init(struct sk_buff_head *list, 2270 struct sk_buff_head *head) 2271{ 2272 if (!skb_queue_empty(list)) { 2273 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2274 head->qlen += list->qlen; 2275 __skb_queue_head_init(list); 2276 } 2277} 2278 2279/** 2280 * skb_queue_splice_tail - join two skb lists, each list being a queue 2281 * @list: the new list to add 2282 * @head: the place to add it in the first list 2283 */ 2284static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 2285 struct sk_buff_head *head) 2286{ 2287 if (!skb_queue_empty(list)) { 2288 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2289 head->qlen += list->qlen; 2290 } 2291} 2292 2293/** 2294 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 2295 * @list: the new list to add 2296 * @head: the place to add it in the first list 2297 * 2298 * Each of the lists is a queue. 2299 * The list at @list is reinitialised 2300 */ 2301static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 2302 struct sk_buff_head *head) 2303{ 2304 if (!skb_queue_empty(list)) { 2305 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2306 head->qlen += list->qlen; 2307 __skb_queue_head_init(list); 2308 } 2309} 2310 2311/** 2312 * __skb_queue_after - queue a buffer at the list head 2313 * @list: list to use 2314 * @prev: place after this buffer 2315 * @newsk: buffer to queue 2316 * 2317 * Queue a buffer int the middle of a list. This function takes no locks 2318 * and you must therefore hold required locks before calling it. 2319 * 2320 * A buffer cannot be placed on two lists at the same time. 2321 */ 2322static inline void __skb_queue_after(struct sk_buff_head *list, 2323 struct sk_buff *prev, 2324 struct sk_buff *newsk) 2325{ 2326 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list); 2327} 2328 2329void skb_append(struct sk_buff *old, struct sk_buff *newsk, 2330 struct sk_buff_head *list); 2331 2332static inline void __skb_queue_before(struct sk_buff_head *list, 2333 struct sk_buff *next, 2334 struct sk_buff *newsk) 2335{ 2336 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list); 2337} 2338 2339/** 2340 * __skb_queue_head - queue a buffer at the list head 2341 * @list: list to use 2342 * @newsk: buffer to queue 2343 * 2344 * Queue a buffer at the start of a list. This function takes no locks 2345 * and you must therefore hold required locks before calling it. 2346 * 2347 * A buffer cannot be placed on two lists at the same time. 2348 */ 2349static inline void __skb_queue_head(struct sk_buff_head *list, 2350 struct sk_buff *newsk) 2351{ 2352 __skb_queue_after(list, (struct sk_buff *)list, newsk); 2353} 2354void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 2355 2356/** 2357 * __skb_queue_tail - queue a buffer at the list tail 2358 * @list: list to use 2359 * @newsk: buffer to queue 2360 * 2361 * Queue a buffer at the end of a list. This function takes no locks 2362 * and you must therefore hold required locks before calling it. 2363 * 2364 * A buffer cannot be placed on two lists at the same time. 2365 */ 2366static inline void __skb_queue_tail(struct sk_buff_head *list, 2367 struct sk_buff *newsk) 2368{ 2369 __skb_queue_before(list, (struct sk_buff *)list, newsk); 2370} 2371void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 2372 2373/* 2374 * remove sk_buff from list. _Must_ be called atomically, and with 2375 * the list known.. 2376 */ 2377void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 2378static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 2379{ 2380 struct sk_buff *next, *prev; 2381 2382 WRITE_ONCE(list->qlen, list->qlen - 1); 2383 next = skb->next; 2384 prev = skb->prev; 2385 skb->next = skb->prev = NULL; 2386 WRITE_ONCE(next->prev, prev); 2387 WRITE_ONCE(prev->next, next); 2388} 2389 2390/** 2391 * __skb_dequeue - remove from the head of the queue 2392 * @list: list to dequeue from 2393 * 2394 * Remove the head of the list. This function does not take any locks 2395 * so must be used with appropriate locks held only. The head item is 2396 * returned or %NULL if the list is empty. 2397 */ 2398static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 2399{ 2400 struct sk_buff *skb = skb_peek(list); 2401 if (skb) 2402 __skb_unlink(skb, list); 2403 return skb; 2404} 2405struct sk_buff *skb_dequeue(struct sk_buff_head *list); 2406 2407/** 2408 * __skb_dequeue_tail - remove from the tail of the queue 2409 * @list: list to dequeue from 2410 * 2411 * Remove the tail of the list. This function does not take any locks 2412 * so must be used with appropriate locks held only. The tail item is 2413 * returned or %NULL if the list is empty. 2414 */ 2415static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 2416{ 2417 struct sk_buff *skb = skb_peek_tail(list); 2418 if (skb) 2419 __skb_unlink(skb, list); 2420 return skb; 2421} 2422struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 2423 2424 2425static inline bool skb_is_nonlinear(const struct sk_buff *skb) 2426{ 2427 return skb->data_len; 2428} 2429 2430static inline unsigned int skb_headlen(const struct sk_buff *skb) 2431{ 2432 return skb->len - skb->data_len; 2433} 2434 2435static inline unsigned int __skb_pagelen(const struct sk_buff *skb) 2436{ 2437 unsigned int i, len = 0; 2438 2439 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--) 2440 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 2441 return len; 2442} 2443 2444static inline unsigned int skb_pagelen(const struct sk_buff *skb) 2445{ 2446 return skb_headlen(skb) + __skb_pagelen(skb); 2447} 2448 2449static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag, 2450 netmem_ref netmem, int off, 2451 int size) 2452{ 2453 frag->netmem = netmem; 2454 frag->offset = off; 2455 skb_frag_size_set(frag, size); 2456} 2457 2458static inline void skb_frag_fill_page_desc(skb_frag_t *frag, 2459 struct page *page, 2460 int off, int size) 2461{ 2462 skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size); 2463} 2464 2465static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo, 2466 int i, netmem_ref netmem, 2467 int off, int size) 2468{ 2469 skb_frag_t *frag = &shinfo->frags[i]; 2470 2471 skb_frag_fill_netmem_desc(frag, netmem, off, size); 2472} 2473 2474static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo, 2475 int i, struct page *page, 2476 int off, int size) 2477{ 2478 __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off, 2479 size); 2480} 2481 2482/** 2483 * skb_len_add - adds a number to len fields of skb 2484 * @skb: buffer to add len to 2485 * @delta: number of bytes to add 2486 */ 2487static inline void skb_len_add(struct sk_buff *skb, int delta) 2488{ 2489 skb->len += delta; 2490 skb->data_len += delta; 2491 skb->truesize += delta; 2492} 2493 2494/** 2495 * __skb_fill_netmem_desc - initialise a fragment in an skb 2496 * @skb: buffer containing fragment to be initialised 2497 * @i: fragment index to initialise 2498 * @netmem: the netmem to use for this fragment 2499 * @off: the offset to the data with @page 2500 * @size: the length of the data 2501 * 2502 * Initialises the @i'th fragment of @skb to point to &size bytes at 2503 * offset @off within @page. 2504 * 2505 * Does not take any additional reference on the fragment. 2506 */ 2507static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i, 2508 netmem_ref netmem, int off, int size) 2509{ 2510 struct page *page = netmem_to_page(netmem); 2511 2512 __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size); 2513 2514 /* Propagate page pfmemalloc to the skb if we can. The problem is 2515 * that not all callers have unique ownership of the page but rely 2516 * on page_is_pfmemalloc doing the right thing(tm). 2517 */ 2518 page = compound_head(page); 2519 if (page_is_pfmemalloc(page)) 2520 skb->pfmemalloc = true; 2521} 2522 2523static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 2524 struct page *page, int off, int size) 2525{ 2526 __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); 2527} 2528 2529static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i, 2530 netmem_ref netmem, int off, int size) 2531{ 2532 __skb_fill_netmem_desc(skb, i, netmem, off, size); 2533 skb_shinfo(skb)->nr_frags = i + 1; 2534} 2535 2536/** 2537 * skb_fill_page_desc - initialise a paged fragment in an skb 2538 * @skb: buffer containing fragment to be initialised 2539 * @i: paged fragment index to initialise 2540 * @page: the page to use for this fragment 2541 * @off: the offset to the data with @page 2542 * @size: the length of the data 2543 * 2544 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 2545 * @skb to point to @size bytes at offset @off within @page. In 2546 * addition updates @skb such that @i is the last fragment. 2547 * 2548 * Does not take any additional reference on the fragment. 2549 */ 2550static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 2551 struct page *page, int off, int size) 2552{ 2553 skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); 2554} 2555 2556/** 2557 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb 2558 * @skb: buffer containing fragment to be initialised 2559 * @i: paged fragment index to initialise 2560 * @page: the page to use for this fragment 2561 * @off: the offset to the data with @page 2562 * @size: the length of the data 2563 * 2564 * Variant of skb_fill_page_desc() which does not deal with 2565 * pfmemalloc, if page is not owned by us. 2566 */ 2567static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i, 2568 struct page *page, int off, 2569 int size) 2570{ 2571 struct skb_shared_info *shinfo = skb_shinfo(skb); 2572 2573 __skb_fill_page_desc_noacc(shinfo, i, page, off, size); 2574 shinfo->nr_frags = i + 1; 2575} 2576 2577void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, netmem_ref netmem, 2578 int off, int size, unsigned int truesize); 2579 2580static inline void skb_add_rx_frag(struct sk_buff *skb, int i, 2581 struct page *page, int off, int size, 2582 unsigned int truesize) 2583{ 2584 skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size, 2585 truesize); 2586} 2587 2588void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 2589 unsigned int truesize); 2590 2591#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 2592 2593#ifdef NET_SKBUFF_DATA_USES_OFFSET 2594static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2595{ 2596 return skb->head + skb->tail; 2597} 2598 2599static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2600{ 2601 skb->tail = skb->data - skb->head; 2602} 2603 2604static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2605{ 2606 skb_reset_tail_pointer(skb); 2607 skb->tail += offset; 2608} 2609 2610#else /* NET_SKBUFF_DATA_USES_OFFSET */ 2611static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2612{ 2613 return skb->tail; 2614} 2615 2616static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2617{ 2618 skb->tail = skb->data; 2619} 2620 2621static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2622{ 2623 skb->tail = skb->data + offset; 2624} 2625 2626#endif /* NET_SKBUFF_DATA_USES_OFFSET */ 2627 2628static inline void skb_assert_len(struct sk_buff *skb) 2629{ 2630#ifdef CONFIG_DEBUG_NET 2631 if (WARN_ONCE(!skb->len, "%s\n", __func__)) 2632 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); 2633#endif /* CONFIG_DEBUG_NET */ 2634} 2635 2636/* 2637 * Add data to an sk_buff 2638 */ 2639void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 2640void *skb_put(struct sk_buff *skb, unsigned int len); 2641static inline void *__skb_put(struct sk_buff *skb, unsigned int len) 2642{ 2643 void *tmp = skb_tail_pointer(skb); 2644 SKB_LINEAR_ASSERT(skb); 2645 skb->tail += len; 2646 skb->len += len; 2647 return tmp; 2648} 2649 2650static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len) 2651{ 2652 void *tmp = __skb_put(skb, len); 2653 2654 memset(tmp, 0, len); 2655 return tmp; 2656} 2657 2658static inline void *__skb_put_data(struct sk_buff *skb, const void *data, 2659 unsigned int len) 2660{ 2661 void *tmp = __skb_put(skb, len); 2662 2663 memcpy(tmp, data, len); 2664 return tmp; 2665} 2666 2667static inline void __skb_put_u8(struct sk_buff *skb, u8 val) 2668{ 2669 *(u8 *)__skb_put(skb, 1) = val; 2670} 2671 2672static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len) 2673{ 2674 void *tmp = skb_put(skb, len); 2675 2676 memset(tmp, 0, len); 2677 2678 return tmp; 2679} 2680 2681static inline void *skb_put_data(struct sk_buff *skb, const void *data, 2682 unsigned int len) 2683{ 2684 void *tmp = skb_put(skb, len); 2685 2686 memcpy(tmp, data, len); 2687 2688 return tmp; 2689} 2690 2691static inline void skb_put_u8(struct sk_buff *skb, u8 val) 2692{ 2693 *(u8 *)skb_put(skb, 1) = val; 2694} 2695 2696void *skb_push(struct sk_buff *skb, unsigned int len); 2697static inline void *__skb_push(struct sk_buff *skb, unsigned int len) 2698{ 2699 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2700 2701 skb->data -= len; 2702 skb->len += len; 2703 return skb->data; 2704} 2705 2706void *skb_pull(struct sk_buff *skb, unsigned int len); 2707static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) 2708{ 2709 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2710 2711 skb->len -= len; 2712 if (unlikely(skb->len < skb->data_len)) { 2713#if defined(CONFIG_DEBUG_NET) 2714 skb->len += len; 2715 pr_err("__skb_pull(len=%u)\n", len); 2716 skb_dump(KERN_ERR, skb, false); 2717#endif 2718 BUG(); 2719 } 2720 return skb->data += len; 2721} 2722 2723static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len) 2724{ 2725 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 2726} 2727 2728void *skb_pull_data(struct sk_buff *skb, size_t len); 2729 2730void *__pskb_pull_tail(struct sk_buff *skb, int delta); 2731 2732static inline enum skb_drop_reason 2733pskb_may_pull_reason(struct sk_buff *skb, unsigned int len) 2734{ 2735 DEBUG_NET_WARN_ON_ONCE(len > INT_MAX); 2736 2737 if (likely(len <= skb_headlen(skb))) 2738 return SKB_NOT_DROPPED_YET; 2739 2740 if (unlikely(len > skb->len)) 2741 return SKB_DROP_REASON_PKT_TOO_SMALL; 2742 2743 if (unlikely(!__pskb_pull_tail(skb, len - skb_headlen(skb)))) 2744 return SKB_DROP_REASON_NOMEM; 2745 2746 return SKB_NOT_DROPPED_YET; 2747} 2748 2749static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len) 2750{ 2751 return pskb_may_pull_reason(skb, len) == SKB_NOT_DROPPED_YET; 2752} 2753 2754static inline void *pskb_pull(struct sk_buff *skb, unsigned int len) 2755{ 2756 if (!pskb_may_pull(skb, len)) 2757 return NULL; 2758 2759 skb->len -= len; 2760 return skb->data += len; 2761} 2762 2763void skb_condense(struct sk_buff *skb); 2764 2765/** 2766 * skb_headroom - bytes at buffer head 2767 * @skb: buffer to check 2768 * 2769 * Return the number of bytes of free space at the head of an &sk_buff. 2770 */ 2771static inline unsigned int skb_headroom(const struct sk_buff *skb) 2772{ 2773 return skb->data - skb->head; 2774} 2775 2776/** 2777 * skb_tailroom - bytes at buffer end 2778 * @skb: buffer to check 2779 * 2780 * Return the number of bytes of free space at the tail of an sk_buff 2781 */ 2782static inline int skb_tailroom(const struct sk_buff *skb) 2783{ 2784 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 2785} 2786 2787/** 2788 * skb_availroom - bytes at buffer end 2789 * @skb: buffer to check 2790 * 2791 * Return the number of bytes of free space at the tail of an sk_buff 2792 * allocated by sk_stream_alloc() 2793 */ 2794static inline int skb_availroom(const struct sk_buff *skb) 2795{ 2796 if (skb_is_nonlinear(skb)) 2797 return 0; 2798 2799 return skb->end - skb->tail - skb->reserved_tailroom; 2800} 2801 2802/** 2803 * skb_reserve - adjust headroom 2804 * @skb: buffer to alter 2805 * @len: bytes to move 2806 * 2807 * Increase the headroom of an empty &sk_buff by reducing the tail 2808 * room. This is only allowed for an empty buffer. 2809 */ 2810static inline void skb_reserve(struct sk_buff *skb, int len) 2811{ 2812 skb->data += len; 2813 skb->tail += len; 2814} 2815 2816/** 2817 * skb_tailroom_reserve - adjust reserved_tailroom 2818 * @skb: buffer to alter 2819 * @mtu: maximum amount of headlen permitted 2820 * @needed_tailroom: minimum amount of reserved_tailroom 2821 * 2822 * Set reserved_tailroom so that headlen can be as large as possible but 2823 * not larger than mtu and tailroom cannot be smaller than 2824 * needed_tailroom. 2825 * The required headroom should already have been reserved before using 2826 * this function. 2827 */ 2828static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu, 2829 unsigned int needed_tailroom) 2830{ 2831 SKB_LINEAR_ASSERT(skb); 2832 if (mtu < skb_tailroom(skb) - needed_tailroom) 2833 /* use at most mtu */ 2834 skb->reserved_tailroom = skb_tailroom(skb) - mtu; 2835 else 2836 /* use up to all available space */ 2837 skb->reserved_tailroom = needed_tailroom; 2838} 2839 2840#define ENCAP_TYPE_ETHER 0 2841#define ENCAP_TYPE_IPPROTO 1 2842 2843static inline void skb_set_inner_protocol(struct sk_buff *skb, 2844 __be16 protocol) 2845{ 2846 skb->inner_protocol = protocol; 2847 skb->inner_protocol_type = ENCAP_TYPE_ETHER; 2848} 2849 2850static inline void skb_set_inner_ipproto(struct sk_buff *skb, 2851 __u8 ipproto) 2852{ 2853 skb->inner_ipproto = ipproto; 2854 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; 2855} 2856 2857static inline void skb_reset_inner_headers(struct sk_buff *skb) 2858{ 2859 skb->inner_mac_header = skb->mac_header; 2860 skb->inner_network_header = skb->network_header; 2861 skb->inner_transport_header = skb->transport_header; 2862} 2863 2864static inline void skb_reset_mac_len(struct sk_buff *skb) 2865{ 2866 skb->mac_len = skb->network_header - skb->mac_header; 2867} 2868 2869static inline unsigned char *skb_inner_transport_header(const struct sk_buff 2870 *skb) 2871{ 2872 return skb->head + skb->inner_transport_header; 2873} 2874 2875static inline int skb_inner_transport_offset(const struct sk_buff *skb) 2876{ 2877 return skb_inner_transport_header(skb) - skb->data; 2878} 2879 2880static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 2881{ 2882 skb->inner_transport_header = skb->data - skb->head; 2883} 2884 2885static inline void skb_set_inner_transport_header(struct sk_buff *skb, 2886 const int offset) 2887{ 2888 skb_reset_inner_transport_header(skb); 2889 skb->inner_transport_header += offset; 2890} 2891 2892static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 2893{ 2894 return skb->head + skb->inner_network_header; 2895} 2896 2897static inline void skb_reset_inner_network_header(struct sk_buff *skb) 2898{ 2899 skb->inner_network_header = skb->data - skb->head; 2900} 2901 2902static inline void skb_set_inner_network_header(struct sk_buff *skb, 2903 const int offset) 2904{ 2905 skb_reset_inner_network_header(skb); 2906 skb->inner_network_header += offset; 2907} 2908 2909static inline bool skb_inner_network_header_was_set(const struct sk_buff *skb) 2910{ 2911 return skb->inner_network_header > 0; 2912} 2913 2914static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 2915{ 2916 return skb->head + skb->inner_mac_header; 2917} 2918 2919static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 2920{ 2921 skb->inner_mac_header = skb->data - skb->head; 2922} 2923 2924static inline void skb_set_inner_mac_header(struct sk_buff *skb, 2925 const int offset) 2926{ 2927 skb_reset_inner_mac_header(skb); 2928 skb->inner_mac_header += offset; 2929} 2930static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 2931{ 2932 return skb->transport_header != (typeof(skb->transport_header))~0U; 2933} 2934 2935static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 2936{ 2937 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); 2938 return skb->head + skb->transport_header; 2939} 2940 2941static inline void skb_reset_transport_header(struct sk_buff *skb) 2942{ 2943 skb->transport_header = skb->data - skb->head; 2944} 2945 2946static inline void skb_set_transport_header(struct sk_buff *skb, 2947 const int offset) 2948{ 2949 skb_reset_transport_header(skb); 2950 skb->transport_header += offset; 2951} 2952 2953static inline unsigned char *skb_network_header(const struct sk_buff *skb) 2954{ 2955 return skb->head + skb->network_header; 2956} 2957 2958static inline void skb_reset_network_header(struct sk_buff *skb) 2959{ 2960 skb->network_header = skb->data - skb->head; 2961} 2962 2963static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 2964{ 2965 skb_reset_network_header(skb); 2966 skb->network_header += offset; 2967} 2968 2969static inline int skb_mac_header_was_set(const struct sk_buff *skb) 2970{ 2971 return skb->mac_header != (typeof(skb->mac_header))~0U; 2972} 2973 2974static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 2975{ 2976 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 2977 return skb->head + skb->mac_header; 2978} 2979 2980static inline int skb_mac_offset(const struct sk_buff *skb) 2981{ 2982 return skb_mac_header(skb) - skb->data; 2983} 2984 2985static inline u32 skb_mac_header_len(const struct sk_buff *skb) 2986{ 2987 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 2988 return skb->network_header - skb->mac_header; 2989} 2990 2991static inline void skb_unset_mac_header(struct sk_buff *skb) 2992{ 2993 skb->mac_header = (typeof(skb->mac_header))~0U; 2994} 2995 2996static inline void skb_reset_mac_header(struct sk_buff *skb) 2997{ 2998 skb->mac_header = skb->data - skb->head; 2999} 3000 3001static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 3002{ 3003 skb_reset_mac_header(skb); 3004 skb->mac_header += offset; 3005} 3006 3007static inline void skb_pop_mac_header(struct sk_buff *skb) 3008{ 3009 skb->mac_header = skb->network_header; 3010} 3011 3012static inline void skb_probe_transport_header(struct sk_buff *skb) 3013{ 3014 struct flow_keys_basic keys; 3015 3016 if (skb_transport_header_was_set(skb)) 3017 return; 3018 3019 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 3020 NULL, 0, 0, 0, 0)) 3021 skb_set_transport_header(skb, keys.control.thoff); 3022} 3023 3024static inline void skb_mac_header_rebuild(struct sk_buff *skb) 3025{ 3026 if (skb_mac_header_was_set(skb)) { 3027 const unsigned char *old_mac = skb_mac_header(skb); 3028 3029 skb_set_mac_header(skb, -skb->mac_len); 3030 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 3031 } 3032} 3033 3034static inline int skb_checksum_start_offset(const struct sk_buff *skb) 3035{ 3036 return skb->csum_start - skb_headroom(skb); 3037} 3038 3039static inline unsigned char *skb_checksum_start(const struct sk_buff *skb) 3040{ 3041 return skb->head + skb->csum_start; 3042} 3043 3044static inline int skb_transport_offset(const struct sk_buff *skb) 3045{ 3046 return skb_transport_header(skb) - skb->data; 3047} 3048 3049static inline u32 skb_network_header_len(const struct sk_buff *skb) 3050{ 3051 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); 3052 return skb->transport_header - skb->network_header; 3053} 3054 3055static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 3056{ 3057 return skb->inner_transport_header - skb->inner_network_header; 3058} 3059 3060static inline int skb_network_offset(const struct sk_buff *skb) 3061{ 3062 return skb_network_header(skb) - skb->data; 3063} 3064 3065static inline int skb_inner_network_offset(const struct sk_buff *skb) 3066{ 3067 return skb_inner_network_header(skb) - skb->data; 3068} 3069 3070static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 3071{ 3072 return pskb_may_pull(skb, skb_network_offset(skb) + len); 3073} 3074 3075/* 3076 * CPUs often take a performance hit when accessing unaligned memory 3077 * locations. The actual performance hit varies, it can be small if the 3078 * hardware handles it or large if we have to take an exception and fix it 3079 * in software. 3080 * 3081 * Since an ethernet header is 14 bytes network drivers often end up with 3082 * the IP header at an unaligned offset. The IP header can be aligned by 3083 * shifting the start of the packet by 2 bytes. Drivers should do this 3084 * with: 3085 * 3086 * skb_reserve(skb, NET_IP_ALIGN); 3087 * 3088 * The downside to this alignment of the IP header is that the DMA is now 3089 * unaligned. On some architectures the cost of an unaligned DMA is high 3090 * and this cost outweighs the gains made by aligning the IP header. 3091 * 3092 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 3093 * to be overridden. 3094 */ 3095#ifndef NET_IP_ALIGN 3096#define NET_IP_ALIGN 2 3097#endif 3098 3099/* 3100 * The networking layer reserves some headroom in skb data (via 3101 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 3102 * the header has to grow. In the default case, if the header has to grow 3103 * 32 bytes or less we avoid the reallocation. 3104 * 3105 * Unfortunately this headroom changes the DMA alignment of the resulting 3106 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 3107 * on some architectures. An architecture can override this value, 3108 * perhaps setting it to a cacheline in size (since that will maintain 3109 * cacheline alignment of the DMA). It must be a power of 2. 3110 * 3111 * Various parts of the networking layer expect at least 32 bytes of 3112 * headroom, you should not reduce this. 3113 * 3114 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 3115 * to reduce average number of cache lines per packet. 3116 * get_rps_cpu() for example only access one 64 bytes aligned block : 3117 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 3118 */ 3119#ifndef NET_SKB_PAD 3120#define NET_SKB_PAD max(32, L1_CACHE_BYTES) 3121#endif 3122 3123int ___pskb_trim(struct sk_buff *skb, unsigned int len); 3124 3125static inline void __skb_set_length(struct sk_buff *skb, unsigned int len) 3126{ 3127 if (WARN_ON(skb_is_nonlinear(skb))) 3128 return; 3129 skb->len = len; 3130 skb_set_tail_pointer(skb, len); 3131} 3132 3133static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 3134{ 3135 __skb_set_length(skb, len); 3136} 3137 3138void skb_trim(struct sk_buff *skb, unsigned int len); 3139 3140static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 3141{ 3142 if (skb->data_len) 3143 return ___pskb_trim(skb, len); 3144 __skb_trim(skb, len); 3145 return 0; 3146} 3147 3148static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 3149{ 3150 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 3151} 3152 3153/** 3154 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 3155 * @skb: buffer to alter 3156 * @len: new length 3157 * 3158 * This is identical to pskb_trim except that the caller knows that 3159 * the skb is not cloned so we should never get an error due to out- 3160 * of-memory. 3161 */ 3162static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 3163{ 3164 int err = pskb_trim(skb, len); 3165 BUG_ON(err); 3166} 3167 3168static inline int __skb_grow(struct sk_buff *skb, unsigned int len) 3169{ 3170 unsigned int diff = len - skb->len; 3171 3172 if (skb_tailroom(skb) < diff) { 3173 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb), 3174 GFP_ATOMIC); 3175 if (ret) 3176 return ret; 3177 } 3178 __skb_set_length(skb, len); 3179 return 0; 3180} 3181 3182/** 3183 * skb_orphan - orphan a buffer 3184 * @skb: buffer to orphan 3185 * 3186 * If a buffer currently has an owner then we call the owner's 3187 * destructor function and make the @skb unowned. The buffer continues 3188 * to exist but is no longer charged to its former owner. 3189 */ 3190static inline void skb_orphan(struct sk_buff *skb) 3191{ 3192 if (skb->destructor) { 3193 skb->destructor(skb); 3194 skb->destructor = NULL; 3195 skb->sk = NULL; 3196 } else { 3197 BUG_ON(skb->sk); 3198 } 3199} 3200 3201/** 3202 * skb_orphan_frags - orphan the frags contained in a buffer 3203 * @skb: buffer to orphan frags from 3204 * @gfp_mask: allocation mask for replacement pages 3205 * 3206 * For each frag in the SKB which needs a destructor (i.e. has an 3207 * owner) create a copy of that frag and release the original 3208 * page by calling the destructor. 3209 */ 3210static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 3211{ 3212 if (likely(!skb_zcopy(skb))) 3213 return 0; 3214 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN) 3215 return 0; 3216 return skb_copy_ubufs(skb, gfp_mask); 3217} 3218 3219/* Frags must be orphaned, even if refcounted, if skb might loop to rx path */ 3220static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask) 3221{ 3222 if (likely(!skb_zcopy(skb))) 3223 return 0; 3224 return skb_copy_ubufs(skb, gfp_mask); 3225} 3226 3227/** 3228 * __skb_queue_purge_reason - empty a list 3229 * @list: list to empty 3230 * @reason: drop reason 3231 * 3232 * Delete all buffers on an &sk_buff list. Each buffer is removed from 3233 * the list and one reference dropped. This function does not take the 3234 * list lock and the caller must hold the relevant locks to use it. 3235 */ 3236static inline void __skb_queue_purge_reason(struct sk_buff_head *list, 3237 enum skb_drop_reason reason) 3238{ 3239 struct sk_buff *skb; 3240 3241 while ((skb = __skb_dequeue(list)) != NULL) 3242 kfree_skb_reason(skb, reason); 3243} 3244 3245static inline void __skb_queue_purge(struct sk_buff_head *list) 3246{ 3247 __skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE); 3248} 3249 3250void skb_queue_purge_reason(struct sk_buff_head *list, 3251 enum skb_drop_reason reason); 3252 3253static inline void skb_queue_purge(struct sk_buff_head *list) 3254{ 3255 skb_queue_purge_reason(list, SKB_DROP_REASON_QUEUE_PURGE); 3256} 3257 3258unsigned int skb_rbtree_purge(struct rb_root *root); 3259void skb_errqueue_purge(struct sk_buff_head *list); 3260 3261void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3262 3263/** 3264 * netdev_alloc_frag - allocate a page fragment 3265 * @fragsz: fragment size 3266 * 3267 * Allocates a frag from a page for receive buffer. 3268 * Uses GFP_ATOMIC allocations. 3269 */ 3270static inline void *netdev_alloc_frag(unsigned int fragsz) 3271{ 3272 return __netdev_alloc_frag_align(fragsz, ~0u); 3273} 3274 3275static inline void *netdev_alloc_frag_align(unsigned int fragsz, 3276 unsigned int align) 3277{ 3278 WARN_ON_ONCE(!is_power_of_2(align)); 3279 return __netdev_alloc_frag_align(fragsz, -align); 3280} 3281 3282struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 3283 gfp_t gfp_mask); 3284 3285/** 3286 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 3287 * @dev: network device to receive on 3288 * @length: length to allocate 3289 * 3290 * Allocate a new &sk_buff and assign it a usage count of one. The 3291 * buffer has unspecified headroom built in. Users should allocate 3292 * the headroom they think they need without accounting for the 3293 * built in space. The built in space is used for optimisations. 3294 * 3295 * %NULL is returned if there is no free memory. Although this function 3296 * allocates memory it can be called from an interrupt. 3297 */ 3298static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 3299 unsigned int length) 3300{ 3301 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 3302} 3303 3304/* legacy helper around __netdev_alloc_skb() */ 3305static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 3306 gfp_t gfp_mask) 3307{ 3308 return __netdev_alloc_skb(NULL, length, gfp_mask); 3309} 3310 3311/* legacy helper around netdev_alloc_skb() */ 3312static inline struct sk_buff *dev_alloc_skb(unsigned int length) 3313{ 3314 return netdev_alloc_skb(NULL, length); 3315} 3316 3317 3318static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 3319 unsigned int length, gfp_t gfp) 3320{ 3321 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 3322 3323 if (NET_IP_ALIGN && skb) 3324 skb_reserve(skb, NET_IP_ALIGN); 3325 return skb; 3326} 3327 3328static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 3329 unsigned int length) 3330{ 3331 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 3332} 3333 3334static inline void skb_free_frag(void *addr) 3335{ 3336 page_frag_free(addr); 3337} 3338 3339void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3340 3341static inline void *napi_alloc_frag(unsigned int fragsz) 3342{ 3343 return __napi_alloc_frag_align(fragsz, ~0u); 3344} 3345 3346static inline void *napi_alloc_frag_align(unsigned int fragsz, 3347 unsigned int align) 3348{ 3349 WARN_ON_ONCE(!is_power_of_2(align)); 3350 return __napi_alloc_frag_align(fragsz, -align); 3351} 3352 3353struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, 3354 unsigned int length, gfp_t gfp_mask); 3355static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, 3356 unsigned int length) 3357{ 3358 return __napi_alloc_skb(napi, length, GFP_ATOMIC); 3359} 3360void napi_consume_skb(struct sk_buff *skb, int budget); 3361 3362void napi_skb_free_stolen_head(struct sk_buff *skb); 3363void __napi_kfree_skb(struct sk_buff *skb, enum skb_drop_reason reason); 3364 3365/** 3366 * __dev_alloc_pages - allocate page for network Rx 3367 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3368 * @order: size of the allocation 3369 * 3370 * Allocate a new page. 3371 * 3372 * %NULL is returned if there is no free memory. 3373*/ 3374static inline struct page *__dev_alloc_pages(gfp_t gfp_mask, 3375 unsigned int order) 3376{ 3377 /* This piece of code contains several assumptions. 3378 * 1. This is for device Rx, therefore a cold page is preferred. 3379 * 2. The expectation is the user wants a compound page. 3380 * 3. If requesting a order 0 page it will not be compound 3381 * due to the check to see if order has a value in prep_new_page 3382 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to 3383 * code in gfp_to_alloc_flags that should be enforcing this. 3384 */ 3385 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC; 3386 3387 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 3388} 3389 3390static inline struct page *dev_alloc_pages(unsigned int order) 3391{ 3392 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order); 3393} 3394 3395/** 3396 * __dev_alloc_page - allocate a page for network Rx 3397 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3398 * 3399 * Allocate a new page. 3400 * 3401 * %NULL is returned if there is no free memory. 3402 */ 3403static inline struct page *__dev_alloc_page(gfp_t gfp_mask) 3404{ 3405 return __dev_alloc_pages(gfp_mask, 0); 3406} 3407 3408static inline struct page *dev_alloc_page(void) 3409{ 3410 return dev_alloc_pages(0); 3411} 3412 3413/** 3414 * dev_page_is_reusable - check whether a page can be reused for network Rx 3415 * @page: the page to test 3416 * 3417 * A page shouldn't be considered for reusing/recycling if it was allocated 3418 * under memory pressure or at a distant memory node. 3419 * 3420 * Returns false if this page should be returned to page allocator, true 3421 * otherwise. 3422 */ 3423static inline bool dev_page_is_reusable(const struct page *page) 3424{ 3425 return likely(page_to_nid(page) == numa_mem_id() && 3426 !page_is_pfmemalloc(page)); 3427} 3428 3429/** 3430 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 3431 * @page: The page that was allocated from skb_alloc_page 3432 * @skb: The skb that may need pfmemalloc set 3433 */ 3434static inline void skb_propagate_pfmemalloc(const struct page *page, 3435 struct sk_buff *skb) 3436{ 3437 if (page_is_pfmemalloc(page)) 3438 skb->pfmemalloc = true; 3439} 3440 3441/** 3442 * skb_frag_off() - Returns the offset of a skb fragment 3443 * @frag: the paged fragment 3444 */ 3445static inline unsigned int skb_frag_off(const skb_frag_t *frag) 3446{ 3447 return frag->offset; 3448} 3449 3450/** 3451 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta 3452 * @frag: skb fragment 3453 * @delta: value to add 3454 */ 3455static inline void skb_frag_off_add(skb_frag_t *frag, int delta) 3456{ 3457 frag->offset += delta; 3458} 3459 3460/** 3461 * skb_frag_off_set() - Sets the offset of a skb fragment 3462 * @frag: skb fragment 3463 * @offset: offset of fragment 3464 */ 3465static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset) 3466{ 3467 frag->offset = offset; 3468} 3469 3470/** 3471 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment 3472 * @fragto: skb fragment where offset is set 3473 * @fragfrom: skb fragment offset is copied from 3474 */ 3475static inline void skb_frag_off_copy(skb_frag_t *fragto, 3476 const skb_frag_t *fragfrom) 3477{ 3478 fragto->offset = fragfrom->offset; 3479} 3480 3481/** 3482 * skb_frag_page - retrieve the page referred to by a paged fragment 3483 * @frag: the paged fragment 3484 * 3485 * Returns the &struct page associated with @frag. 3486 */ 3487static inline struct page *skb_frag_page(const skb_frag_t *frag) 3488{ 3489 return netmem_to_page(frag->netmem); 3490} 3491 3492/** 3493 * __skb_frag_ref - take an addition reference on a paged fragment. 3494 * @frag: the paged fragment 3495 * 3496 * Takes an additional reference on the paged fragment @frag. 3497 */ 3498static inline void __skb_frag_ref(skb_frag_t *frag) 3499{ 3500 get_page(skb_frag_page(frag)); 3501} 3502 3503/** 3504 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 3505 * @skb: the buffer 3506 * @f: the fragment offset. 3507 * 3508 * Takes an additional reference on the @f'th paged fragment of @skb. 3509 */ 3510static inline void skb_frag_ref(struct sk_buff *skb, int f) 3511{ 3512 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 3513} 3514 3515int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, 3516 unsigned int headroom); 3517int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, 3518 struct bpf_prog *prog); 3519bool napi_pp_put_page(struct page *page, bool napi_safe); 3520 3521static inline void 3522skb_page_unref(const struct sk_buff *skb, struct page *page, bool napi_safe) 3523{ 3524#ifdef CONFIG_PAGE_POOL 3525 if (skb->pp_recycle && napi_pp_put_page(page, napi_safe)) 3526 return; 3527#endif 3528 put_page(page); 3529} 3530 3531static inline void 3532napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe) 3533{ 3534 struct page *page = skb_frag_page(frag); 3535 3536#ifdef CONFIG_PAGE_POOL 3537 if (recycle && napi_pp_put_page(page, napi_safe)) 3538 return; 3539#endif 3540 put_page(page); 3541} 3542 3543/** 3544 * __skb_frag_unref - release a reference on a paged fragment. 3545 * @frag: the paged fragment 3546 * @recycle: recycle the page if allocated via page_pool 3547 * 3548 * Releases a reference on the paged fragment @frag 3549 * or recycles the page via the page_pool API. 3550 */ 3551static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle) 3552{ 3553 napi_frag_unref(frag, recycle, false); 3554} 3555 3556/** 3557 * skb_frag_unref - release a reference on a paged fragment of an skb. 3558 * @skb: the buffer 3559 * @f: the fragment offset 3560 * 3561 * Releases a reference on the @f'th paged fragment of @skb. 3562 */ 3563static inline void skb_frag_unref(struct sk_buff *skb, int f) 3564{ 3565 struct skb_shared_info *shinfo = skb_shinfo(skb); 3566 3567 if (!skb_zcopy_managed(skb)) 3568 __skb_frag_unref(&shinfo->frags[f], skb->pp_recycle); 3569} 3570 3571/** 3572 * skb_frag_address - gets the address of the data contained in a paged fragment 3573 * @frag: the paged fragment buffer 3574 * 3575 * Returns the address of the data within @frag. The page must already 3576 * be mapped. 3577 */ 3578static inline void *skb_frag_address(const skb_frag_t *frag) 3579{ 3580 return page_address(skb_frag_page(frag)) + skb_frag_off(frag); 3581} 3582 3583/** 3584 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 3585 * @frag: the paged fragment buffer 3586 * 3587 * Returns the address of the data within @frag. Checks that the page 3588 * is mapped and returns %NULL otherwise. 3589 */ 3590static inline void *skb_frag_address_safe(const skb_frag_t *frag) 3591{ 3592 void *ptr = page_address(skb_frag_page(frag)); 3593 if (unlikely(!ptr)) 3594 return NULL; 3595 3596 return ptr + skb_frag_off(frag); 3597} 3598 3599/** 3600 * skb_frag_page_copy() - sets the page in a fragment from another fragment 3601 * @fragto: skb fragment where page is set 3602 * @fragfrom: skb fragment page is copied from 3603 */ 3604static inline void skb_frag_page_copy(skb_frag_t *fragto, 3605 const skb_frag_t *fragfrom) 3606{ 3607 fragto->netmem = fragfrom->netmem; 3608} 3609 3610bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 3611 3612/** 3613 * skb_frag_dma_map - maps a paged fragment via the DMA API 3614 * @dev: the device to map the fragment to 3615 * @frag: the paged fragment to map 3616 * @offset: the offset within the fragment (starting at the 3617 * fragment's own offset) 3618 * @size: the number of bytes to map 3619 * @dir: the direction of the mapping (``PCI_DMA_*``) 3620 * 3621 * Maps the page associated with @frag to @device. 3622 */ 3623static inline dma_addr_t skb_frag_dma_map(struct device *dev, 3624 const skb_frag_t *frag, 3625 size_t offset, size_t size, 3626 enum dma_data_direction dir) 3627{ 3628 return dma_map_page(dev, skb_frag_page(frag), 3629 skb_frag_off(frag) + offset, size, dir); 3630} 3631 3632static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 3633 gfp_t gfp_mask) 3634{ 3635 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 3636} 3637 3638 3639static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb, 3640 gfp_t gfp_mask) 3641{ 3642 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true); 3643} 3644 3645 3646/** 3647 * skb_clone_writable - is the header of a clone writable 3648 * @skb: buffer to check 3649 * @len: length up to which to write 3650 * 3651 * Returns true if modifying the header part of the cloned buffer 3652 * does not requires the data to be copied. 3653 */ 3654static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 3655{ 3656 return !skb_header_cloned(skb) && 3657 skb_headroom(skb) + len <= skb->hdr_len; 3658} 3659 3660static inline int skb_try_make_writable(struct sk_buff *skb, 3661 unsigned int write_len) 3662{ 3663 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) && 3664 pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 3665} 3666 3667static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 3668 int cloned) 3669{ 3670 int delta = 0; 3671 3672 if (headroom > skb_headroom(skb)) 3673 delta = headroom - skb_headroom(skb); 3674 3675 if (delta || cloned) 3676 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 3677 GFP_ATOMIC); 3678 return 0; 3679} 3680 3681/** 3682 * skb_cow - copy header of skb when it is required 3683 * @skb: buffer to cow 3684 * @headroom: needed headroom 3685 * 3686 * If the skb passed lacks sufficient headroom or its data part 3687 * is shared, data is reallocated. If reallocation fails, an error 3688 * is returned and original skb is not changed. 3689 * 3690 * The result is skb with writable area skb->head...skb->tail 3691 * and at least @headroom of space at head. 3692 */ 3693static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 3694{ 3695 return __skb_cow(skb, headroom, skb_cloned(skb)); 3696} 3697 3698/** 3699 * skb_cow_head - skb_cow but only making the head writable 3700 * @skb: buffer to cow 3701 * @headroom: needed headroom 3702 * 3703 * This function is identical to skb_cow except that we replace the 3704 * skb_cloned check by skb_header_cloned. It should be used when 3705 * you only need to push on some header and do not need to modify 3706 * the data. 3707 */ 3708static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 3709{ 3710 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 3711} 3712 3713/** 3714 * skb_padto - pad an skbuff up to a minimal size 3715 * @skb: buffer to pad 3716 * @len: minimal length 3717 * 3718 * Pads up a buffer to ensure the trailing bytes exist and are 3719 * blanked. If the buffer already contains sufficient data it 3720 * is untouched. Otherwise it is extended. Returns zero on 3721 * success. The skb is freed on error. 3722 */ 3723static inline int skb_padto(struct sk_buff *skb, unsigned int len) 3724{ 3725 unsigned int size = skb->len; 3726 if (likely(size >= len)) 3727 return 0; 3728 return skb_pad(skb, len - size); 3729} 3730 3731/** 3732 * __skb_put_padto - increase size and pad an skbuff up to a minimal size 3733 * @skb: buffer to pad 3734 * @len: minimal length 3735 * @free_on_error: free buffer on error 3736 * 3737 * Pads up a buffer to ensure the trailing bytes exist and are 3738 * blanked. If the buffer already contains sufficient data it 3739 * is untouched. Otherwise it is extended. Returns zero on 3740 * success. The skb is freed on error if @free_on_error is true. 3741 */ 3742static inline int __must_check __skb_put_padto(struct sk_buff *skb, 3743 unsigned int len, 3744 bool free_on_error) 3745{ 3746 unsigned int size = skb->len; 3747 3748 if (unlikely(size < len)) { 3749 len -= size; 3750 if (__skb_pad(skb, len, free_on_error)) 3751 return -ENOMEM; 3752 __skb_put(skb, len); 3753 } 3754 return 0; 3755} 3756 3757/** 3758 * skb_put_padto - increase size and pad an skbuff up to a minimal size 3759 * @skb: buffer to pad 3760 * @len: minimal length 3761 * 3762 * Pads up a buffer to ensure the trailing bytes exist and are 3763 * blanked. If the buffer already contains sufficient data it 3764 * is untouched. Otherwise it is extended. Returns zero on 3765 * success. The skb is freed on error. 3766 */ 3767static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len) 3768{ 3769 return __skb_put_padto(skb, len, true); 3770} 3771 3772bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i) 3773 __must_check; 3774 3775static inline int skb_add_data(struct sk_buff *skb, 3776 struct iov_iter *from, int copy) 3777{ 3778 const int off = skb->len; 3779 3780 if (skb->ip_summed == CHECKSUM_NONE) { 3781 __wsum csum = 0; 3782 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy, 3783 &csum, from)) { 3784 skb->csum = csum_block_add(skb->csum, csum, off); 3785 return 0; 3786 } 3787 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from)) 3788 return 0; 3789 3790 __skb_trim(skb, off); 3791 return -EFAULT; 3792} 3793 3794static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 3795 const struct page *page, int off) 3796{ 3797 if (skb_zcopy(skb)) 3798 return false; 3799 if (i) { 3800 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1]; 3801 3802 return page == skb_frag_page(frag) && 3803 off == skb_frag_off(frag) + skb_frag_size(frag); 3804 } 3805 return false; 3806} 3807 3808static inline int __skb_linearize(struct sk_buff *skb) 3809{ 3810 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 3811} 3812 3813/** 3814 * skb_linearize - convert paged skb to linear one 3815 * @skb: buffer to linarize 3816 * 3817 * If there is no free memory -ENOMEM is returned, otherwise zero 3818 * is returned and the old skb data released. 3819 */ 3820static inline int skb_linearize(struct sk_buff *skb) 3821{ 3822 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 3823} 3824 3825/** 3826 * skb_has_shared_frag - can any frag be overwritten 3827 * @skb: buffer to test 3828 * 3829 * Return true if the skb has at least one frag that might be modified 3830 * by an external entity (as in vmsplice()/sendfile()) 3831 */ 3832static inline bool skb_has_shared_frag(const struct sk_buff *skb) 3833{ 3834 return skb_is_nonlinear(skb) && 3835 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; 3836} 3837 3838/** 3839 * skb_linearize_cow - make sure skb is linear and writable 3840 * @skb: buffer to process 3841 * 3842 * If there is no free memory -ENOMEM is returned, otherwise zero 3843 * is returned and the old skb data released. 3844 */ 3845static inline int skb_linearize_cow(struct sk_buff *skb) 3846{ 3847 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 3848 __skb_linearize(skb) : 0; 3849} 3850 3851static __always_inline void 3852__skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3853 unsigned int off) 3854{ 3855 if (skb->ip_summed == CHECKSUM_COMPLETE) 3856 skb->csum = csum_block_sub(skb->csum, 3857 csum_partial(start, len, 0), off); 3858 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3859 skb_checksum_start_offset(skb) < 0) 3860 skb->ip_summed = CHECKSUM_NONE; 3861} 3862 3863/** 3864 * skb_postpull_rcsum - update checksum for received skb after pull 3865 * @skb: buffer to update 3866 * @start: start of data before pull 3867 * @len: length of data pulled 3868 * 3869 * After doing a pull on a received packet, you need to call this to 3870 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 3871 * CHECKSUM_NONE so that it can be recomputed from scratch. 3872 */ 3873static inline void skb_postpull_rcsum(struct sk_buff *skb, 3874 const void *start, unsigned int len) 3875{ 3876 if (skb->ip_summed == CHECKSUM_COMPLETE) 3877 skb->csum = wsum_negate(csum_partial(start, len, 3878 wsum_negate(skb->csum))); 3879 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3880 skb_checksum_start_offset(skb) < 0) 3881 skb->ip_summed = CHECKSUM_NONE; 3882} 3883 3884static __always_inline void 3885__skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3886 unsigned int off) 3887{ 3888 if (skb->ip_summed == CHECKSUM_COMPLETE) 3889 skb->csum = csum_block_add(skb->csum, 3890 csum_partial(start, len, 0), off); 3891} 3892 3893/** 3894 * skb_postpush_rcsum - update checksum for received skb after push 3895 * @skb: buffer to update 3896 * @start: start of data after push 3897 * @len: length of data pushed 3898 * 3899 * After doing a push on a received packet, you need to call this to 3900 * update the CHECKSUM_COMPLETE checksum. 3901 */ 3902static inline void skb_postpush_rcsum(struct sk_buff *skb, 3903 const void *start, unsigned int len) 3904{ 3905 __skb_postpush_rcsum(skb, start, len, 0); 3906} 3907 3908void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 3909 3910/** 3911 * skb_push_rcsum - push skb and update receive checksum 3912 * @skb: buffer to update 3913 * @len: length of data pulled 3914 * 3915 * This function performs an skb_push on the packet and updates 3916 * the CHECKSUM_COMPLETE checksum. It should be used on 3917 * receive path processing instead of skb_push unless you know 3918 * that the checksum difference is zero (e.g., a valid IP header) 3919 * or you are setting ip_summed to CHECKSUM_NONE. 3920 */ 3921static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len) 3922{ 3923 skb_push(skb, len); 3924 skb_postpush_rcsum(skb, skb->data, len); 3925 return skb->data; 3926} 3927 3928int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len); 3929/** 3930 * pskb_trim_rcsum - trim received skb and update checksum 3931 * @skb: buffer to trim 3932 * @len: new length 3933 * 3934 * This is exactly the same as pskb_trim except that it ensures the 3935 * checksum of received packets are still valid after the operation. 3936 * It can change skb pointers. 3937 */ 3938 3939static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3940{ 3941 if (likely(len >= skb->len)) 3942 return 0; 3943 return pskb_trim_rcsum_slow(skb, len); 3944} 3945 3946static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3947{ 3948 if (skb->ip_summed == CHECKSUM_COMPLETE) 3949 skb->ip_summed = CHECKSUM_NONE; 3950 __skb_trim(skb, len); 3951 return 0; 3952} 3953 3954static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len) 3955{ 3956 if (skb->ip_summed == CHECKSUM_COMPLETE) 3957 skb->ip_summed = CHECKSUM_NONE; 3958 return __skb_grow(skb, len); 3959} 3960 3961#define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode) 3962#define skb_rb_first(root) rb_to_skb(rb_first(root)) 3963#define skb_rb_last(root) rb_to_skb(rb_last(root)) 3964#define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode)) 3965#define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode)) 3966 3967#define skb_queue_walk(queue, skb) \ 3968 for (skb = (queue)->next; \ 3969 skb != (struct sk_buff *)(queue); \ 3970 skb = skb->next) 3971 3972#define skb_queue_walk_safe(queue, skb, tmp) \ 3973 for (skb = (queue)->next, tmp = skb->next; \ 3974 skb != (struct sk_buff *)(queue); \ 3975 skb = tmp, tmp = skb->next) 3976 3977#define skb_queue_walk_from(queue, skb) \ 3978 for (; skb != (struct sk_buff *)(queue); \ 3979 skb = skb->next) 3980 3981#define skb_rbtree_walk(skb, root) \ 3982 for (skb = skb_rb_first(root); skb != NULL; \ 3983 skb = skb_rb_next(skb)) 3984 3985#define skb_rbtree_walk_from(skb) \ 3986 for (; skb != NULL; \ 3987 skb = skb_rb_next(skb)) 3988 3989#define skb_rbtree_walk_from_safe(skb, tmp) \ 3990 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \ 3991 skb = tmp) 3992 3993#define skb_queue_walk_from_safe(queue, skb, tmp) \ 3994 for (tmp = skb->next; \ 3995 skb != (struct sk_buff *)(queue); \ 3996 skb = tmp, tmp = skb->next) 3997 3998#define skb_queue_reverse_walk(queue, skb) \ 3999 for (skb = (queue)->prev; \ 4000 skb != (struct sk_buff *)(queue); \ 4001 skb = skb->prev) 4002 4003#define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 4004 for (skb = (queue)->prev, tmp = skb->prev; \ 4005 skb != (struct sk_buff *)(queue); \ 4006 skb = tmp, tmp = skb->prev) 4007 4008#define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 4009 for (tmp = skb->prev; \ 4010 skb != (struct sk_buff *)(queue); \ 4011 skb = tmp, tmp = skb->prev) 4012 4013static inline bool skb_has_frag_list(const struct sk_buff *skb) 4014{ 4015 return skb_shinfo(skb)->frag_list != NULL; 4016} 4017 4018static inline void skb_frag_list_init(struct sk_buff *skb) 4019{ 4020 skb_shinfo(skb)->frag_list = NULL; 4021} 4022 4023#define skb_walk_frags(skb, iter) \ 4024 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 4025 4026 4027int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue, 4028 int *err, long *timeo_p, 4029 const struct sk_buff *skb); 4030struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 4031 struct sk_buff_head *queue, 4032 unsigned int flags, 4033 int *off, int *err, 4034 struct sk_buff **last); 4035struct sk_buff *__skb_try_recv_datagram(struct sock *sk, 4036 struct sk_buff_head *queue, 4037 unsigned int flags, int *off, int *err, 4038 struct sk_buff **last); 4039struct sk_buff *__skb_recv_datagram(struct sock *sk, 4040 struct sk_buff_head *sk_queue, 4041 unsigned int flags, int *off, int *err); 4042struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err); 4043__poll_t datagram_poll(struct file *file, struct socket *sock, 4044 struct poll_table_struct *wait); 4045int skb_copy_datagram_iter(const struct sk_buff *from, int offset, 4046 struct iov_iter *to, int size); 4047static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 4048 struct msghdr *msg, int size) 4049{ 4050 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size); 4051} 4052int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 4053 struct msghdr *msg); 4054int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, 4055 struct iov_iter *to, int len, 4056 struct ahash_request *hash); 4057int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, 4058 struct iov_iter *from, int len); 4059int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 4060void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 4061void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len); 4062static inline void skb_free_datagram_locked(struct sock *sk, 4063 struct sk_buff *skb) 4064{ 4065 __skb_free_datagram_locked(sk, skb, 0); 4066} 4067int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 4068int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 4069int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 4070__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 4071 int len); 4072int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, 4073 struct pipe_inode_info *pipe, unsigned int len, 4074 unsigned int flags); 4075int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, 4076 int len); 4077int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len); 4078void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 4079unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 4080int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, 4081 int len, int hlen); 4082void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 4083int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 4084void skb_scrub_packet(struct sk_buff *skb, bool xnet); 4085struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 4086struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features, 4087 unsigned int offset); 4088struct sk_buff *skb_vlan_untag(struct sk_buff *skb); 4089int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len); 4090int skb_ensure_writable_head_tail(struct sk_buff *skb, struct net_device *dev); 4091int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); 4092int skb_vlan_pop(struct sk_buff *skb); 4093int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); 4094int skb_eth_pop(struct sk_buff *skb); 4095int skb_eth_push(struct sk_buff *skb, const unsigned char *dst, 4096 const unsigned char *src); 4097int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, 4098 int mac_len, bool ethernet); 4099int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, 4100 bool ethernet); 4101int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse); 4102int skb_mpls_dec_ttl(struct sk_buff *skb); 4103struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy, 4104 gfp_t gfp); 4105 4106static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len) 4107{ 4108 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT; 4109} 4110 4111static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len) 4112{ 4113 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 4114} 4115 4116struct skb_checksum_ops { 4117 __wsum (*update)(const void *mem, int len, __wsum wsum); 4118 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 4119}; 4120 4121extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly; 4122 4123__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 4124 __wsum csum, const struct skb_checksum_ops *ops); 4125__wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 4126 __wsum csum); 4127 4128static inline void * __must_check 4129__skb_header_pointer(const struct sk_buff *skb, int offset, int len, 4130 const void *data, int hlen, void *buffer) 4131{ 4132 if (likely(hlen - offset >= len)) 4133 return (void *)data + offset; 4134 4135 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0)) 4136 return NULL; 4137 4138 return buffer; 4139} 4140 4141static inline void * __must_check 4142skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) 4143{ 4144 return __skb_header_pointer(skb, offset, len, skb->data, 4145 skb_headlen(skb), buffer); 4146} 4147 4148static inline void * __must_check 4149skb_pointer_if_linear(const struct sk_buff *skb, int offset, int len) 4150{ 4151 if (likely(skb_headlen(skb) - offset >= len)) 4152 return skb->data + offset; 4153 return NULL; 4154} 4155 4156/** 4157 * skb_needs_linearize - check if we need to linearize a given skb 4158 * depending on the given device features. 4159 * @skb: socket buffer to check 4160 * @features: net device features 4161 * 4162 * Returns true if either: 4163 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 4164 * 2. skb is fragmented and the device does not support SG. 4165 */ 4166static inline bool skb_needs_linearize(struct sk_buff *skb, 4167 netdev_features_t features) 4168{ 4169 return skb_is_nonlinear(skb) && 4170 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 4171 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 4172} 4173 4174static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 4175 void *to, 4176 const unsigned int len) 4177{ 4178 memcpy(to, skb->data, len); 4179} 4180 4181static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 4182 const int offset, void *to, 4183 const unsigned int len) 4184{ 4185 memcpy(to, skb->data + offset, len); 4186} 4187 4188static inline void skb_copy_to_linear_data(struct sk_buff *skb, 4189 const void *from, 4190 const unsigned int len) 4191{ 4192 memcpy(skb->data, from, len); 4193} 4194 4195static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 4196 const int offset, 4197 const void *from, 4198 const unsigned int len) 4199{ 4200 memcpy(skb->data + offset, from, len); 4201} 4202 4203void skb_init(void); 4204 4205static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 4206{ 4207 return skb->tstamp; 4208} 4209 4210/** 4211 * skb_get_timestamp - get timestamp from a skb 4212 * @skb: skb to get stamp from 4213 * @stamp: pointer to struct __kernel_old_timeval to store stamp in 4214 * 4215 * Timestamps are stored in the skb as offsets to a base timestamp. 4216 * This function converts the offset back to a struct timeval and stores 4217 * it in stamp. 4218 */ 4219static inline void skb_get_timestamp(const struct sk_buff *skb, 4220 struct __kernel_old_timeval *stamp) 4221{ 4222 *stamp = ns_to_kernel_old_timeval(skb->tstamp); 4223} 4224 4225static inline void skb_get_new_timestamp(const struct sk_buff *skb, 4226 struct __kernel_sock_timeval *stamp) 4227{ 4228 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4229 4230 stamp->tv_sec = ts.tv_sec; 4231 stamp->tv_usec = ts.tv_nsec / 1000; 4232} 4233 4234static inline void skb_get_timestampns(const struct sk_buff *skb, 4235 struct __kernel_old_timespec *stamp) 4236{ 4237 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4238 4239 stamp->tv_sec = ts.tv_sec; 4240 stamp->tv_nsec = ts.tv_nsec; 4241} 4242 4243static inline void skb_get_new_timestampns(const struct sk_buff *skb, 4244 struct __kernel_timespec *stamp) 4245{ 4246 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4247 4248 stamp->tv_sec = ts.tv_sec; 4249 stamp->tv_nsec = ts.tv_nsec; 4250} 4251 4252static inline void __net_timestamp(struct sk_buff *skb) 4253{ 4254 skb->tstamp = ktime_get_real(); 4255 skb->mono_delivery_time = 0; 4256} 4257 4258static inline ktime_t net_timedelta(ktime_t t) 4259{ 4260 return ktime_sub(ktime_get_real(), t); 4261} 4262 4263static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt, 4264 bool mono) 4265{ 4266 skb->tstamp = kt; 4267 skb->mono_delivery_time = kt && mono; 4268} 4269 4270DECLARE_STATIC_KEY_FALSE(netstamp_needed_key); 4271 4272/* It is used in the ingress path to clear the delivery_time. 4273 * If needed, set the skb->tstamp to the (rcv) timestamp. 4274 */ 4275static inline void skb_clear_delivery_time(struct sk_buff *skb) 4276{ 4277 if (skb->mono_delivery_time) { 4278 skb->mono_delivery_time = 0; 4279 if (static_branch_unlikely(&netstamp_needed_key)) 4280 skb->tstamp = ktime_get_real(); 4281 else 4282 skb->tstamp = 0; 4283 } 4284} 4285 4286static inline void skb_clear_tstamp(struct sk_buff *skb) 4287{ 4288 if (skb->mono_delivery_time) 4289 return; 4290 4291 skb->tstamp = 0; 4292} 4293 4294static inline ktime_t skb_tstamp(const struct sk_buff *skb) 4295{ 4296 if (skb->mono_delivery_time) 4297 return 0; 4298 4299 return skb->tstamp; 4300} 4301 4302static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond) 4303{ 4304 if (!skb->mono_delivery_time && skb->tstamp) 4305 return skb->tstamp; 4306 4307 if (static_branch_unlikely(&netstamp_needed_key) || cond) 4308 return ktime_get_real(); 4309 4310 return 0; 4311} 4312 4313static inline u8 skb_metadata_len(const struct sk_buff *skb) 4314{ 4315 return skb_shinfo(skb)->meta_len; 4316} 4317 4318static inline void *skb_metadata_end(const struct sk_buff *skb) 4319{ 4320 return skb_mac_header(skb); 4321} 4322 4323static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, 4324 const struct sk_buff *skb_b, 4325 u8 meta_len) 4326{ 4327 const void *a = skb_metadata_end(skb_a); 4328 const void *b = skb_metadata_end(skb_b); 4329 u64 diffs = 0; 4330 4331 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || 4332 BITS_PER_LONG != 64) 4333 goto slow; 4334 4335 /* Using more efficient variant than plain call to memcmp(). */ 4336 switch (meta_len) { 4337#define __it(x, op) (x -= sizeof(u##op)) 4338#define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op)) 4339 case 32: diffs |= __it_diff(a, b, 64); 4340 fallthrough; 4341 case 24: diffs |= __it_diff(a, b, 64); 4342 fallthrough; 4343 case 16: diffs |= __it_diff(a, b, 64); 4344 fallthrough; 4345 case 8: diffs |= __it_diff(a, b, 64); 4346 break; 4347 case 28: diffs |= __it_diff(a, b, 64); 4348 fallthrough; 4349 case 20: diffs |= __it_diff(a, b, 64); 4350 fallthrough; 4351 case 12: diffs |= __it_diff(a, b, 64); 4352 fallthrough; 4353 case 4: diffs |= __it_diff(a, b, 32); 4354 break; 4355 default: 4356slow: 4357 return memcmp(a - meta_len, b - meta_len, meta_len); 4358 } 4359 return diffs; 4360} 4361 4362static inline bool skb_metadata_differs(const struct sk_buff *skb_a, 4363 const struct sk_buff *skb_b) 4364{ 4365 u8 len_a = skb_metadata_len(skb_a); 4366 u8 len_b = skb_metadata_len(skb_b); 4367 4368 if (!(len_a | len_b)) 4369 return false; 4370 4371 return len_a != len_b ? 4372 true : __skb_metadata_differs(skb_a, skb_b, len_a); 4373} 4374 4375static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len) 4376{ 4377 skb_shinfo(skb)->meta_len = meta_len; 4378} 4379 4380static inline void skb_metadata_clear(struct sk_buff *skb) 4381{ 4382 skb_metadata_set(skb, 0); 4383} 4384 4385struct sk_buff *skb_clone_sk(struct sk_buff *skb); 4386 4387#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 4388 4389void skb_clone_tx_timestamp(struct sk_buff *skb); 4390bool skb_defer_rx_timestamp(struct sk_buff *skb); 4391 4392#else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 4393 4394static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 4395{ 4396} 4397 4398static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 4399{ 4400 return false; 4401} 4402 4403#endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 4404 4405/** 4406 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 4407 * 4408 * PHY drivers may accept clones of transmitted packets for 4409 * timestamping via their phy_driver.txtstamp method. These drivers 4410 * must call this function to return the skb back to the stack with a 4411 * timestamp. 4412 * 4413 * @skb: clone of the original outgoing packet 4414 * @hwtstamps: hardware time stamps 4415 * 4416 */ 4417void skb_complete_tx_timestamp(struct sk_buff *skb, 4418 struct skb_shared_hwtstamps *hwtstamps); 4419 4420void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, 4421 struct skb_shared_hwtstamps *hwtstamps, 4422 struct sock *sk, int tstype); 4423 4424/** 4425 * skb_tstamp_tx - queue clone of skb with send time stamps 4426 * @orig_skb: the original outgoing packet 4427 * @hwtstamps: hardware time stamps, may be NULL if not available 4428 * 4429 * If the skb has a socket associated, then this function clones the 4430 * skb (thus sharing the actual data and optional structures), stores 4431 * the optional hardware time stamping information (if non NULL) or 4432 * generates a software time stamp (otherwise), then queues the clone 4433 * to the error queue of the socket. Errors are silently ignored. 4434 */ 4435void skb_tstamp_tx(struct sk_buff *orig_skb, 4436 struct skb_shared_hwtstamps *hwtstamps); 4437 4438/** 4439 * skb_tx_timestamp() - Driver hook for transmit timestamping 4440 * 4441 * Ethernet MAC Drivers should call this function in their hard_xmit() 4442 * function immediately before giving the sk_buff to the MAC hardware. 4443 * 4444 * Specifically, one should make absolutely sure that this function is 4445 * called before TX completion of this packet can trigger. Otherwise 4446 * the packet could potentially already be freed. 4447 * 4448 * @skb: A socket buffer. 4449 */ 4450static inline void skb_tx_timestamp(struct sk_buff *skb) 4451{ 4452 skb_clone_tx_timestamp(skb); 4453 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) 4454 skb_tstamp_tx(skb, NULL); 4455} 4456 4457/** 4458 * skb_complete_wifi_ack - deliver skb with wifi status 4459 * 4460 * @skb: the original outgoing packet 4461 * @acked: ack status 4462 * 4463 */ 4464void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 4465 4466__sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 4467__sum16 __skb_checksum_complete(struct sk_buff *skb); 4468 4469static inline int skb_csum_unnecessary(const struct sk_buff *skb) 4470{ 4471 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) || 4472 skb->csum_valid || 4473 (skb->ip_summed == CHECKSUM_PARTIAL && 4474 skb_checksum_start_offset(skb) >= 0)); 4475} 4476 4477/** 4478 * skb_checksum_complete - Calculate checksum of an entire packet 4479 * @skb: packet to process 4480 * 4481 * This function calculates the checksum over the entire packet plus 4482 * the value of skb->csum. The latter can be used to supply the 4483 * checksum of a pseudo header as used by TCP/UDP. It returns the 4484 * checksum. 4485 * 4486 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 4487 * this function can be used to verify that checksum on received 4488 * packets. In that case the function should return zero if the 4489 * checksum is correct. In particular, this function will return zero 4490 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 4491 * hardware has already verified the correctness of the checksum. 4492 */ 4493static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 4494{ 4495 return skb_csum_unnecessary(skb) ? 4496 0 : __skb_checksum_complete(skb); 4497} 4498 4499static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb) 4500{ 4501 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4502 if (skb->csum_level == 0) 4503 skb->ip_summed = CHECKSUM_NONE; 4504 else 4505 skb->csum_level--; 4506 } 4507} 4508 4509static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) 4510{ 4511 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4512 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 4513 skb->csum_level++; 4514 } else if (skb->ip_summed == CHECKSUM_NONE) { 4515 skb->ip_summed = CHECKSUM_UNNECESSARY; 4516 skb->csum_level = 0; 4517 } 4518} 4519 4520static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb) 4521{ 4522 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4523 skb->ip_summed = CHECKSUM_NONE; 4524 skb->csum_level = 0; 4525 } 4526} 4527 4528/* Check if we need to perform checksum complete validation. 4529 * 4530 * Returns true if checksum complete is needed, false otherwise 4531 * (either checksum is unnecessary or zero checksum is allowed). 4532 */ 4533static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, 4534 bool zero_okay, 4535 __sum16 check) 4536{ 4537 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) { 4538 skb->csum_valid = 1; 4539 __skb_decr_checksum_unnecessary(skb); 4540 return false; 4541 } 4542 4543 return true; 4544} 4545 4546/* For small packets <= CHECKSUM_BREAK perform checksum complete directly 4547 * in checksum_init. 4548 */ 4549#define CHECKSUM_BREAK 76 4550 4551/* Unset checksum-complete 4552 * 4553 * Unset checksum complete can be done when packet is being modified 4554 * (uncompressed for instance) and checksum-complete value is 4555 * invalidated. 4556 */ 4557static inline void skb_checksum_complete_unset(struct sk_buff *skb) 4558{ 4559 if (skb->ip_summed == CHECKSUM_COMPLETE) 4560 skb->ip_summed = CHECKSUM_NONE; 4561} 4562 4563/* Validate (init) checksum based on checksum complete. 4564 * 4565 * Return values: 4566 * 0: checksum is validated or try to in skb_checksum_complete. In the latter 4567 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo 4568 * checksum is stored in skb->csum for use in __skb_checksum_complete 4569 * non-zero: value of invalid checksum 4570 * 4571 */ 4572static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, 4573 bool complete, 4574 __wsum psum) 4575{ 4576 if (skb->ip_summed == CHECKSUM_COMPLETE) { 4577 if (!csum_fold(csum_add(psum, skb->csum))) { 4578 skb->csum_valid = 1; 4579 return 0; 4580 } 4581 } 4582 4583 skb->csum = psum; 4584 4585 if (complete || skb->len <= CHECKSUM_BREAK) { 4586 __sum16 csum; 4587 4588 csum = __skb_checksum_complete(skb); 4589 skb->csum_valid = !csum; 4590 return csum; 4591 } 4592 4593 return 0; 4594} 4595 4596static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) 4597{ 4598 return 0; 4599} 4600 4601/* Perform checksum validate (init). Note that this is a macro since we only 4602 * want to calculate the pseudo header which is an input function if necessary. 4603 * First we try to validate without any computation (checksum unnecessary) and 4604 * then calculate based on checksum complete calling the function to compute 4605 * pseudo header. 4606 * 4607 * Return values: 4608 * 0: checksum is validated or try to in skb_checksum_complete 4609 * non-zero: value of invalid checksum 4610 */ 4611#define __skb_checksum_validate(skb, proto, complete, \ 4612 zero_okay, check, compute_pseudo) \ 4613({ \ 4614 __sum16 __ret = 0; \ 4615 skb->csum_valid = 0; \ 4616 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ 4617 __ret = __skb_checksum_validate_complete(skb, \ 4618 complete, compute_pseudo(skb, proto)); \ 4619 __ret; \ 4620}) 4621 4622#define skb_checksum_init(skb, proto, compute_pseudo) \ 4623 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) 4624 4625#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ 4626 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) 4627 4628#define skb_checksum_validate(skb, proto, compute_pseudo) \ 4629 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) 4630 4631#define skb_checksum_validate_zero_check(skb, proto, check, \ 4632 compute_pseudo) \ 4633 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo) 4634 4635#define skb_checksum_simple_validate(skb) \ 4636 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) 4637 4638static inline bool __skb_checksum_convert_check(struct sk_buff *skb) 4639{ 4640 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid); 4641} 4642 4643static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo) 4644{ 4645 skb->csum = ~pseudo; 4646 skb->ip_summed = CHECKSUM_COMPLETE; 4647} 4648 4649#define skb_checksum_try_convert(skb, proto, compute_pseudo) \ 4650do { \ 4651 if (__skb_checksum_convert_check(skb)) \ 4652 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \ 4653} while (0) 4654 4655static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr, 4656 u16 start, u16 offset) 4657{ 4658 skb->ip_summed = CHECKSUM_PARTIAL; 4659 skb->csum_start = ((unsigned char *)ptr + start) - skb->head; 4660 skb->csum_offset = offset - start; 4661} 4662 4663/* Update skbuf and packet to reflect the remote checksum offload operation. 4664 * When called, ptr indicates the starting point for skb->csum when 4665 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete 4666 * here, skb_postpull_rcsum is done so skb->csum start is ptr. 4667 */ 4668static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr, 4669 int start, int offset, bool nopartial) 4670{ 4671 __wsum delta; 4672 4673 if (!nopartial) { 4674 skb_remcsum_adjust_partial(skb, ptr, start, offset); 4675 return; 4676 } 4677 4678 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) { 4679 __skb_checksum_complete(skb); 4680 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data); 4681 } 4682 4683 delta = remcsum_adjust(ptr, skb->csum, start, offset); 4684 4685 /* Adjust skb->csum since we changed the packet */ 4686 skb->csum = csum_add(skb->csum, delta); 4687} 4688 4689static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb) 4690{ 4691#if IS_ENABLED(CONFIG_NF_CONNTRACK) 4692 return (void *)(skb->_nfct & NFCT_PTRMASK); 4693#else 4694 return NULL; 4695#endif 4696} 4697 4698static inline unsigned long skb_get_nfct(const struct sk_buff *skb) 4699{ 4700#if IS_ENABLED(CONFIG_NF_CONNTRACK) 4701 return skb->_nfct; 4702#else 4703 return 0UL; 4704#endif 4705} 4706 4707static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct) 4708{ 4709#if IS_ENABLED(CONFIG_NF_CONNTRACK) 4710 skb->slow_gro |= !!nfct; 4711 skb->_nfct = nfct; 4712#endif 4713} 4714 4715#ifdef CONFIG_SKB_EXTENSIONS 4716enum skb_ext_id { 4717#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 4718 SKB_EXT_BRIDGE_NF, 4719#endif 4720#ifdef CONFIG_XFRM 4721 SKB_EXT_SEC_PATH, 4722#endif 4723#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 4724 TC_SKB_EXT, 4725#endif 4726#if IS_ENABLED(CONFIG_MPTCP) 4727 SKB_EXT_MPTCP, 4728#endif 4729#if IS_ENABLED(CONFIG_MCTP_FLOWS) 4730 SKB_EXT_MCTP, 4731#endif 4732 SKB_EXT_NUM, /* must be last */ 4733}; 4734 4735/** 4736 * struct skb_ext - sk_buff extensions 4737 * @refcnt: 1 on allocation, deallocated on 0 4738 * @offset: offset to add to @data to obtain extension address 4739 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units 4740 * @data: start of extension data, variable sized 4741 * 4742 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows 4743 * to use 'u8' types while allowing up to 2kb worth of extension data. 4744 */ 4745struct skb_ext { 4746 refcount_t refcnt; 4747 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */ 4748 u8 chunks; /* same */ 4749 char data[] __aligned(8); 4750}; 4751 4752struct skb_ext *__skb_ext_alloc(gfp_t flags); 4753void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, 4754 struct skb_ext *ext); 4755void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); 4756void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); 4757void __skb_ext_put(struct skb_ext *ext); 4758 4759static inline void skb_ext_put(struct sk_buff *skb) 4760{ 4761 if (skb->active_extensions) 4762 __skb_ext_put(skb->extensions); 4763} 4764 4765static inline void __skb_ext_copy(struct sk_buff *dst, 4766 const struct sk_buff *src) 4767{ 4768 dst->active_extensions = src->active_extensions; 4769 4770 if (src->active_extensions) { 4771 struct skb_ext *ext = src->extensions; 4772 4773 refcount_inc(&ext->refcnt); 4774 dst->extensions = ext; 4775 } 4776} 4777 4778static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src) 4779{ 4780 skb_ext_put(dst); 4781 __skb_ext_copy(dst, src); 4782} 4783 4784static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i) 4785{ 4786 return !!ext->offset[i]; 4787} 4788 4789static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id) 4790{ 4791 return skb->active_extensions & (1 << id); 4792} 4793 4794static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) 4795{ 4796 if (skb_ext_exist(skb, id)) 4797 __skb_ext_del(skb, id); 4798} 4799 4800static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id) 4801{ 4802 if (skb_ext_exist(skb, id)) { 4803 struct skb_ext *ext = skb->extensions; 4804 4805 return (void *)ext + (ext->offset[id] << 3); 4806 } 4807 4808 return NULL; 4809} 4810 4811static inline void skb_ext_reset(struct sk_buff *skb) 4812{ 4813 if (unlikely(skb->active_extensions)) { 4814 __skb_ext_put(skb->extensions); 4815 skb->active_extensions = 0; 4816 } 4817} 4818 4819static inline bool skb_has_extensions(struct sk_buff *skb) 4820{ 4821 return unlikely(skb->active_extensions); 4822} 4823#else 4824static inline void skb_ext_put(struct sk_buff *skb) {} 4825static inline void skb_ext_reset(struct sk_buff *skb) {} 4826static inline void skb_ext_del(struct sk_buff *skb, int unused) {} 4827static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {} 4828static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {} 4829static inline bool skb_has_extensions(struct sk_buff *skb) { return false; } 4830#endif /* CONFIG_SKB_EXTENSIONS */ 4831 4832static inline void nf_reset_ct(struct sk_buff *skb) 4833{ 4834#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4835 nf_conntrack_put(skb_nfct(skb)); 4836 skb->_nfct = 0; 4837#endif 4838} 4839 4840static inline void nf_reset_trace(struct sk_buff *skb) 4841{ 4842#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 4843 skb->nf_trace = 0; 4844#endif 4845} 4846 4847static inline void ipvs_reset(struct sk_buff *skb) 4848{ 4849#if IS_ENABLED(CONFIG_IP_VS) 4850 skb->ipvs_property = 0; 4851#endif 4852} 4853 4854/* Note: This doesn't put any conntrack info in dst. */ 4855static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src, 4856 bool copy) 4857{ 4858#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4859 dst->_nfct = src->_nfct; 4860 nf_conntrack_get(skb_nfct(src)); 4861#endif 4862#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || IS_ENABLED(CONFIG_NF_TABLES) 4863 if (copy) 4864 dst->nf_trace = src->nf_trace; 4865#endif 4866} 4867 4868static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 4869{ 4870#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4871 nf_conntrack_put(skb_nfct(dst)); 4872#endif 4873 dst->slow_gro = src->slow_gro; 4874 __nf_copy(dst, src, true); 4875} 4876 4877#ifdef CONFIG_NETWORK_SECMARK 4878static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4879{ 4880 to->secmark = from->secmark; 4881} 4882 4883static inline void skb_init_secmark(struct sk_buff *skb) 4884{ 4885 skb->secmark = 0; 4886} 4887#else 4888static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4889{ } 4890 4891static inline void skb_init_secmark(struct sk_buff *skb) 4892{ } 4893#endif 4894 4895static inline int secpath_exists(const struct sk_buff *skb) 4896{ 4897#ifdef CONFIG_XFRM 4898 return skb_ext_exist(skb, SKB_EXT_SEC_PATH); 4899#else 4900 return 0; 4901#endif 4902} 4903 4904static inline bool skb_irq_freeable(const struct sk_buff *skb) 4905{ 4906 return !skb->destructor && 4907 !secpath_exists(skb) && 4908 !skb_nfct(skb) && 4909 !skb->_skb_refdst && 4910 !skb_has_frag_list(skb); 4911} 4912 4913static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 4914{ 4915 skb->queue_mapping = queue_mapping; 4916} 4917 4918static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 4919{ 4920 return skb->queue_mapping; 4921} 4922 4923static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 4924{ 4925 to->queue_mapping = from->queue_mapping; 4926} 4927 4928static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 4929{ 4930 skb->queue_mapping = rx_queue + 1; 4931} 4932 4933static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 4934{ 4935 return skb->queue_mapping - 1; 4936} 4937 4938static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 4939{ 4940 return skb->queue_mapping != 0; 4941} 4942 4943static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val) 4944{ 4945 skb->dst_pending_confirm = val; 4946} 4947 4948static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb) 4949{ 4950 return skb->dst_pending_confirm != 0; 4951} 4952 4953static inline struct sec_path *skb_sec_path(const struct sk_buff *skb) 4954{ 4955#ifdef CONFIG_XFRM 4956 return skb_ext_find(skb, SKB_EXT_SEC_PATH); 4957#else 4958 return NULL; 4959#endif 4960} 4961 4962static inline bool skb_is_gso(const struct sk_buff *skb) 4963{ 4964 return skb_shinfo(skb)->gso_size; 4965} 4966 4967/* Note: Should be called only if skb_is_gso(skb) is true */ 4968static inline bool skb_is_gso_v6(const struct sk_buff *skb) 4969{ 4970 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 4971} 4972 4973/* Note: Should be called only if skb_is_gso(skb) is true */ 4974static inline bool skb_is_gso_sctp(const struct sk_buff *skb) 4975{ 4976 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP; 4977} 4978 4979/* Note: Should be called only if skb_is_gso(skb) is true */ 4980static inline bool skb_is_gso_tcp(const struct sk_buff *skb) 4981{ 4982 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6); 4983} 4984 4985static inline void skb_gso_reset(struct sk_buff *skb) 4986{ 4987 skb_shinfo(skb)->gso_size = 0; 4988 skb_shinfo(skb)->gso_segs = 0; 4989 skb_shinfo(skb)->gso_type = 0; 4990} 4991 4992static inline void skb_increase_gso_size(struct skb_shared_info *shinfo, 4993 u16 increment) 4994{ 4995 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 4996 return; 4997 shinfo->gso_size += increment; 4998} 4999 5000static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo, 5001 u16 decrement) 5002{ 5003 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 5004 return; 5005 shinfo->gso_size -= decrement; 5006} 5007 5008void __skb_warn_lro_forwarding(const struct sk_buff *skb); 5009 5010static inline bool skb_warn_if_lro(const struct sk_buff *skb) 5011{ 5012 /* LRO sets gso_size but not gso_type, whereas if GSO is really 5013 * wanted then gso_type will be set. */ 5014 const struct skb_shared_info *shinfo = skb_shinfo(skb); 5015 5016 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 5017 unlikely(shinfo->gso_type == 0)) { 5018 __skb_warn_lro_forwarding(skb); 5019 return true; 5020 } 5021 return false; 5022} 5023 5024static inline void skb_forward_csum(struct sk_buff *skb) 5025{ 5026 /* Unfortunately we don't support this one. Any brave souls? */ 5027 if (skb->ip_summed == CHECKSUM_COMPLETE) 5028 skb->ip_summed = CHECKSUM_NONE; 5029} 5030 5031/** 5032 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 5033 * @skb: skb to check 5034 * 5035 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 5036 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 5037 * use this helper, to document places where we make this assertion. 5038 */ 5039static inline void skb_checksum_none_assert(const struct sk_buff *skb) 5040{ 5041 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE); 5042} 5043 5044bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 5045 5046int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 5047struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, 5048 unsigned int transport_len, 5049 __sum16(*skb_chkf)(struct sk_buff *skb)); 5050 5051/** 5052 * skb_head_is_locked - Determine if the skb->head is locked down 5053 * @skb: skb to check 5054 * 5055 * The head on skbs build around a head frag can be removed if they are 5056 * not cloned. This function returns true if the skb head is locked down 5057 * due to either being allocated via kmalloc, or by being a clone with 5058 * multiple references to the head. 5059 */ 5060static inline bool skb_head_is_locked(const struct sk_buff *skb) 5061{ 5062 return !skb->head_frag || skb_cloned(skb); 5063} 5064 5065/* Local Checksum Offload. 5066 * Compute outer checksum based on the assumption that the 5067 * inner checksum will be offloaded later. 5068 * See Documentation/networking/checksum-offloads.rst for 5069 * explanation of how this works. 5070 * Fill in outer checksum adjustment (e.g. with sum of outer 5071 * pseudo-header) before calling. 5072 * Also ensure that inner checksum is in linear data area. 5073 */ 5074static inline __wsum lco_csum(struct sk_buff *skb) 5075{ 5076 unsigned char *csum_start = skb_checksum_start(skb); 5077 unsigned char *l4_hdr = skb_transport_header(skb); 5078 __wsum partial; 5079 5080 /* Start with complement of inner checksum adjustment */ 5081 partial = ~csum_unfold(*(__force __sum16 *)(csum_start + 5082 skb->csum_offset)); 5083 5084 /* Add in checksum of our headers (incl. outer checksum 5085 * adjustment filled in by caller) and return result. 5086 */ 5087 return csum_partial(l4_hdr, csum_start - l4_hdr, partial); 5088} 5089 5090static inline bool skb_is_redirected(const struct sk_buff *skb) 5091{ 5092 return skb->redirected; 5093} 5094 5095static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress) 5096{ 5097 skb->redirected = 1; 5098#ifdef CONFIG_NET_REDIRECT 5099 skb->from_ingress = from_ingress; 5100 if (skb->from_ingress) 5101 skb_clear_tstamp(skb); 5102#endif 5103} 5104 5105static inline void skb_reset_redirect(struct sk_buff *skb) 5106{ 5107 skb->redirected = 0; 5108} 5109 5110static inline void skb_set_redirected_noclear(struct sk_buff *skb, 5111 bool from_ingress) 5112{ 5113 skb->redirected = 1; 5114#ifdef CONFIG_NET_REDIRECT 5115 skb->from_ingress = from_ingress; 5116#endif 5117} 5118 5119static inline bool skb_csum_is_sctp(struct sk_buff *skb) 5120{ 5121#if IS_ENABLED(CONFIG_IP_SCTP) 5122 return skb->csum_not_inet; 5123#else 5124 return 0; 5125#endif 5126} 5127 5128static inline void skb_reset_csum_not_inet(struct sk_buff *skb) 5129{ 5130 skb->ip_summed = CHECKSUM_NONE; 5131#if IS_ENABLED(CONFIG_IP_SCTP) 5132 skb->csum_not_inet = 0; 5133#endif 5134} 5135 5136static inline void skb_set_kcov_handle(struct sk_buff *skb, 5137 const u64 kcov_handle) 5138{ 5139#ifdef CONFIG_KCOV 5140 skb->kcov_handle = kcov_handle; 5141#endif 5142} 5143 5144static inline u64 skb_get_kcov_handle(struct sk_buff *skb) 5145{ 5146#ifdef CONFIG_KCOV 5147 return skb->kcov_handle; 5148#else 5149 return 0; 5150#endif 5151} 5152 5153static inline void skb_mark_for_recycle(struct sk_buff *skb) 5154{ 5155#ifdef CONFIG_PAGE_POOL 5156 skb->pp_recycle = 1; 5157#endif 5158} 5159 5160ssize_t skb_splice_from_iter(struct sk_buff *skb, struct iov_iter *iter, 5161 ssize_t maxsize, gfp_t gfp); 5162 5163#endif /* __KERNEL__ */ 5164#endif /* _LINUX_SKBUFF_H */ 5165