1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Definitions for the 'struct sk_buff' memory handlers. 4 * 5 * Authors: 6 * Alan Cox, <[email protected]> 7 * Florian La Roche, <[email protected]> 8 */ 9 10 #ifndef _LINUX_SKBUFF_H 11 #define _LINUX_SKBUFF_H 12 13 #include <linux/kernel.h> 14 #include <linux/compiler.h> 15 #include <linux/time.h> 16 #include <linux/bug.h> 17 #include <linux/bvec.h> 18 #include <linux/cache.h> 19 #include <linux/rbtree.h> 20 #include <linux/socket.h> 21 #include <linux/refcount.h> 22 23 #include <linux/atomic.h> 24 #include <asm/types.h> 25 #include <linux/spinlock.h> 26 #include <linux/net.h> 27 #include <linux/textsearch.h> 28 #include <net/checksum.h> 29 #include <linux/rcupdate.h> 30 #include <linux/hrtimer.h> 31 #include <linux/dma-mapping.h> 32 #include <linux/netdev_features.h> 33 #include <linux/sched.h> 34 #include <linux/sched/clock.h> 35 #include <net/flow_dissector.h> 36 #include <linux/splice.h> 37 #include <linux/in6.h> 38 #include <linux/if_packet.h> 39 #include <linux/llist.h> 40 #include <net/flow.h> 41 #include <net/page_pool.h> 42 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 43 #include <linux/netfilter/nf_conntrack_common.h> 44 #endif 45 #include <net/net_debug.h> 46 47 /** 48 * DOC: skb checksums 49 * 50 * The interface for checksum offload between the stack and networking drivers 51 * is as follows... 52 * 53 * IP checksum related features 54 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 55 * 56 * Drivers advertise checksum offload capabilities in the features of a device. 57 * From the stack's point of view these are capabilities offered by the driver. 58 * A driver typically only advertises features that it is capable of offloading 59 * to its device. 60 * 61 * .. flat-table:: Checksum related device features 62 * :widths: 1 10 63 * 64 * * - %NETIF_F_HW_CSUM 65 * - The driver (or its device) is able to compute one 66 * IP (one's complement) checksum for any combination 67 * of protocols or protocol layering. The checksum is 68 * computed and set in a packet per the CHECKSUM_PARTIAL 69 * interface (see below). 70 * 71 * * - %NETIF_F_IP_CSUM 72 * - Driver (device) is only able to checksum plain 73 * TCP or UDP packets over IPv4. These are specifically 74 * unencapsulated packets of the form IPv4|TCP or 75 * IPv4|UDP where the Protocol field in the IPv4 header 76 * is TCP or UDP. The IPv4 header may contain IP options. 77 * This feature cannot be set in features for a device 78 * with NETIF_F_HW_CSUM also set. This feature is being 79 * DEPRECATED (see below). 80 * 81 * * - %NETIF_F_IPV6_CSUM 82 * - Driver (device) is only able to checksum plain 83 * TCP or UDP packets over IPv6. These are specifically 84 * unencapsulated packets of the form IPv6|TCP or 85 * IPv6|UDP where the Next Header field in the IPv6 86 * header is either TCP or UDP. IPv6 extension headers 87 * are not supported with this feature. This feature 88 * cannot be set in features for a device with 89 * NETIF_F_HW_CSUM also set. This feature is being 90 * DEPRECATED (see below). 91 * 92 * * - %NETIF_F_RXCSUM 93 * - Driver (device) performs receive checksum offload. 94 * This flag is only used to disable the RX checksum 95 * feature for a device. The stack will accept receive 96 * checksum indication in packets received on a device 97 * regardless of whether NETIF_F_RXCSUM is set. 98 * 99 * Checksumming of received packets by device 100 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 101 * 102 * Indication of checksum verification is set in &sk_buff.ip_summed. 103 * Possible values are: 104 * 105 * - %CHECKSUM_NONE 106 * 107 * Device did not checksum this packet e.g. due to lack of capabilities. 108 * The packet contains full (though not verified) checksum in packet but 109 * not in skb->csum. Thus, skb->csum is undefined in this case. 110 * 111 * - %CHECKSUM_UNNECESSARY 112 * 113 * The hardware you're dealing with doesn't calculate the full checksum 114 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums 115 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY 116 * if their checksums are okay. &sk_buff.csum is still undefined in this case 117 * though. A driver or device must never modify the checksum field in the 118 * packet even if checksum is verified. 119 * 120 * %CHECKSUM_UNNECESSARY is applicable to following protocols: 121 * 122 * - TCP: IPv6 and IPv4. 123 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a 124 * zero UDP checksum for either IPv4 or IPv6, the networking stack 125 * may perform further validation in this case. 126 * - GRE: only if the checksum is present in the header. 127 * - SCTP: indicates the CRC in SCTP header has been validated. 128 * - FCOE: indicates the CRC in FC frame has been validated. 129 * 130 * &sk_buff.csum_level indicates the number of consecutive checksums found in 131 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY. 132 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet 133 * and a device is able to verify the checksums for UDP (possibly zero), 134 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to 135 * two. If the device were only able to verify the UDP checksum and not 136 * GRE, either because it doesn't support GRE checksum or because GRE 137 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is 138 * not considered in this case). 139 * 140 * - %CHECKSUM_COMPLETE 141 * 142 * This is the most generic way. The device supplied checksum of the _whole_ 143 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the 144 * hardware doesn't need to parse L3/L4 headers to implement this. 145 * 146 * Notes: 147 * 148 * - Even if device supports only some protocols, but is able to produce 149 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 150 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols. 151 * 152 * - %CHECKSUM_PARTIAL 153 * 154 * A checksum is set up to be offloaded to a device as described in the 155 * output description for CHECKSUM_PARTIAL. This may occur on a packet 156 * received directly from another Linux OS, e.g., a virtualized Linux kernel 157 * on the same host, or it may be set in the input path in GRO or remote 158 * checksum offload. For the purposes of checksum verification, the checksum 159 * referred to by skb->csum_start + skb->csum_offset and any preceding 160 * checksums in the packet are considered verified. Any checksums in the 161 * packet that are after the checksum being offloaded are not considered to 162 * be verified. 163 * 164 * Checksumming on transmit for non-GSO 165 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 166 * 167 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet. 168 * Values are: 169 * 170 * - %CHECKSUM_PARTIAL 171 * 172 * The driver is required to checksum the packet as seen by hard_start_xmit() 173 * from &sk_buff.csum_start up to the end, and to record/write the checksum at 174 * offset &sk_buff.csum_start + &sk_buff.csum_offset. 175 * A driver may verify that the 176 * csum_start and csum_offset values are valid values given the length and 177 * offset of the packet, but it should not attempt to validate that the 178 * checksum refers to a legitimate transport layer checksum -- it is the 179 * purview of the stack to validate that csum_start and csum_offset are set 180 * correctly. 181 * 182 * When the stack requests checksum offload for a packet, the driver MUST 183 * ensure that the checksum is set correctly. A driver can either offload the 184 * checksum calculation to the device, or call skb_checksum_help (in the case 185 * that the device does not support offload for a particular checksum). 186 * 187 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of 188 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate 189 * checksum offload capability. 190 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based 191 * on network device checksumming capabilities: if a packet does not match 192 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of 193 * &sk_buff.csum_not_inet, see :ref:`crc`) 194 * is called to resolve the checksum. 195 * 196 * - %CHECKSUM_NONE 197 * 198 * The skb was already checksummed by the protocol, or a checksum is not 199 * required. 200 * 201 * - %CHECKSUM_UNNECESSARY 202 * 203 * This has the same meaning as CHECKSUM_NONE for checksum offload on 204 * output. 205 * 206 * - %CHECKSUM_COMPLETE 207 * 208 * Not used in checksum output. If a driver observes a packet with this value 209 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set. 210 * 211 * .. _crc: 212 * 213 * Non-IP checksum (CRC) offloads 214 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 215 * 216 * .. flat-table:: 217 * :widths: 1 10 218 * 219 * * - %NETIF_F_SCTP_CRC 220 * - This feature indicates that a device is capable of 221 * offloading the SCTP CRC in a packet. To perform this offload the stack 222 * will set csum_start and csum_offset accordingly, set ip_summed to 223 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication 224 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c. 225 * A driver that supports both IP checksum offload and SCTP CRC32c offload 226 * must verify which offload is configured for a packet by testing the 227 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to 228 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1. 229 * 230 * * - %NETIF_F_FCOE_CRC 231 * - This feature indicates that a device is capable of offloading the FCOE 232 * CRC in a packet. To perform this offload the stack will set ip_summed 233 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset 234 * accordingly. Note that there is no indication in the skbuff that the 235 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports 236 * both IP checksum offload and FCOE CRC offload must verify which offload 237 * is configured for a packet, presumably by inspecting packet headers. 238 * 239 * Checksumming on output with GSO 240 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 241 * 242 * In the case of a GSO packet (skb_is_gso() is true), checksum offload 243 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the 244 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as 245 * part of the GSO operation is implied. If a checksum is being offloaded 246 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and 247 * csum_offset are set to refer to the outermost checksum being offloaded 248 * (two offloaded checksums are possible with UDP encapsulation). 249 */ 250 251 /* Don't change this without changing skb_csum_unnecessary! */ 252 #define CHECKSUM_NONE 0 253 #define CHECKSUM_UNNECESSARY 1 254 #define CHECKSUM_COMPLETE 2 255 #define CHECKSUM_PARTIAL 3 256 257 /* Maximum value in skb->csum_level */ 258 #define SKB_MAX_CSUM_LEVEL 3 259 260 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) 261 #define SKB_WITH_OVERHEAD(X) \ 262 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 263 #define SKB_MAX_ORDER(X, ORDER) \ 264 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 265 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 266 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 267 268 /* return minimum truesize of one skb containing X bytes of data */ 269 #define SKB_TRUESIZE(X) ((X) + \ 270 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 271 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 272 273 struct ahash_request; 274 struct net_device; 275 struct scatterlist; 276 struct pipe_inode_info; 277 struct iov_iter; 278 struct napi_struct; 279 struct bpf_prog; 280 union bpf_attr; 281 struct skb_ext; 282 283 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 284 struct nf_bridge_info { 285 enum { 286 BRNF_PROTO_UNCHANGED, 287 BRNF_PROTO_8021Q, 288 BRNF_PROTO_PPPOE 289 } orig_proto:8; 290 u8 pkt_otherhost:1; 291 u8 in_prerouting:1; 292 u8 bridged_dnat:1; 293 __u16 frag_max_size; 294 struct net_device *physindev; 295 296 /* always valid & non-NULL from FORWARD on, for physdev match */ 297 struct net_device *physoutdev; 298 union { 299 /* prerouting: detect dnat in orig/reply direction */ 300 __be32 ipv4_daddr; 301 struct in6_addr ipv6_daddr; 302 303 /* after prerouting + nat detected: store original source 304 * mac since neigh resolution overwrites it, only used while 305 * skb is out in neigh layer. 306 */ 307 char neigh_header[8]; 308 }; 309 }; 310 #endif 311 312 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 313 /* Chain in tc_skb_ext will be used to share the tc chain with 314 * ovs recirc_id. It will be set to the current chain by tc 315 * and read by ovs to recirc_id. 316 */ 317 struct tc_skb_ext { 318 __u32 chain; 319 __u16 mru; 320 __u16 zone; 321 u8 post_ct:1; 322 u8 post_ct_snat:1; 323 u8 post_ct_dnat:1; 324 }; 325 #endif 326 327 struct sk_buff_head { 328 /* These two members must be first to match sk_buff. */ 329 struct_group_tagged(sk_buff_list, list, 330 struct sk_buff *next; 331 struct sk_buff *prev; 332 ); 333 334 __u32 qlen; 335 spinlock_t lock; 336 }; 337 338 struct sk_buff; 339 340 /* The reason of skb drop, which is used in kfree_skb_reason(). 341 * en...maybe they should be splited by group? 342 * 343 * Each item here should also be in 'TRACE_SKB_DROP_REASON', which is 344 * used to translate the reason to string. 345 */ 346 enum skb_drop_reason { 347 SKB_NOT_DROPPED_YET = 0, 348 SKB_DROP_REASON_NOT_SPECIFIED, /* drop reason is not specified */ 349 SKB_DROP_REASON_NO_SOCKET, /* socket not found */ 350 SKB_DROP_REASON_PKT_TOO_SMALL, /* packet size is too small */ 351 SKB_DROP_REASON_TCP_CSUM, /* TCP checksum error */ 352 SKB_DROP_REASON_SOCKET_FILTER, /* dropped by socket filter */ 353 SKB_DROP_REASON_UDP_CSUM, /* UDP checksum error */ 354 SKB_DROP_REASON_NETFILTER_DROP, /* dropped by netfilter */ 355 SKB_DROP_REASON_OTHERHOST, /* packet don't belong to current 356 * host (interface is in promisc 357 * mode) 358 */ 359 SKB_DROP_REASON_IP_CSUM, /* IP checksum error */ 360 SKB_DROP_REASON_IP_INHDR, /* there is something wrong with 361 * IP header (see 362 * IPSTATS_MIB_INHDRERRORS) 363 */ 364 SKB_DROP_REASON_IP_RPFILTER, /* IP rpfilter validate failed. 365 * see the document for rp_filter 366 * in ip-sysctl.rst for more 367 * information 368 */ 369 SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST, /* destination address of L2 370 * is multicast, but L3 is 371 * unicast. 372 */ 373 SKB_DROP_REASON_XFRM_POLICY, /* xfrm policy check failed */ 374 SKB_DROP_REASON_IP_NOPROTO, /* no support for IP protocol */ 375 SKB_DROP_REASON_SOCKET_RCVBUFF, /* socket receive buff is full */ 376 SKB_DROP_REASON_PROTO_MEM, /* proto memory limition, such as 377 * udp packet drop out of 378 * udp_memory_allocated. 379 */ 380 SKB_DROP_REASON_TCP_MD5NOTFOUND, /* no MD5 hash and one 381 * expected, corresponding 382 * to LINUX_MIB_TCPMD5NOTFOUND 383 */ 384 SKB_DROP_REASON_TCP_MD5UNEXPECTED, /* MD5 hash and we're not 385 * expecting one, corresponding 386 * to LINUX_MIB_TCPMD5UNEXPECTED 387 */ 388 SKB_DROP_REASON_TCP_MD5FAILURE, /* MD5 hash and its wrong, 389 * corresponding to 390 * LINUX_MIB_TCPMD5FAILURE 391 */ 392 SKB_DROP_REASON_SOCKET_BACKLOG, /* failed to add skb to socket 393 * backlog (see 394 * LINUX_MIB_TCPBACKLOGDROP) 395 */ 396 SKB_DROP_REASON_TCP_FLAGS, /* TCP flags invalid */ 397 SKB_DROP_REASON_TCP_ZEROWINDOW, /* TCP receive window size is zero, 398 * see LINUX_MIB_TCPZEROWINDOWDROP 399 */ 400 SKB_DROP_REASON_TCP_OLD_DATA, /* the TCP data reveived is already 401 * received before (spurious retrans 402 * may happened), see 403 * LINUX_MIB_DELAYEDACKLOST 404 */ 405 SKB_DROP_REASON_TCP_OVERWINDOW, /* the TCP data is out of window, 406 * the seq of the first byte exceed 407 * the right edges of receive 408 * window 409 */ 410 SKB_DROP_REASON_TCP_OFOMERGE, /* the data of skb is already in 411 * the ofo queue, corresponding to 412 * LINUX_MIB_TCPOFOMERGE 413 */ 414 SKB_DROP_REASON_TCP_RFC7323_PAWS, /* PAWS check, corresponding to 415 * LINUX_MIB_PAWSESTABREJECTED 416 */ 417 SKB_DROP_REASON_TCP_INVALID_SEQUENCE, /* Not acceptable SEQ field */ 418 SKB_DROP_REASON_TCP_RESET, /* Invalid RST packet */ 419 SKB_DROP_REASON_TCP_INVALID_SYN, /* Incoming packet has unexpected SYN flag */ 420 SKB_DROP_REASON_TCP_CLOSE, /* TCP socket in CLOSE state */ 421 SKB_DROP_REASON_TCP_FASTOPEN, /* dropped by FASTOPEN request socket */ 422 SKB_DROP_REASON_TCP_OLD_ACK, /* TCP ACK is old, but in window */ 423 SKB_DROP_REASON_TCP_TOO_OLD_ACK, /* TCP ACK is too old */ 424 SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, /* TCP ACK for data we haven't sent yet */ 425 SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE, /* pruned from TCP OFO queue */ 426 SKB_DROP_REASON_TCP_OFO_DROP, /* data already in receive queue */ 427 SKB_DROP_REASON_IP_OUTNOROUTES, /* route lookup failed */ 428 SKB_DROP_REASON_BPF_CGROUP_EGRESS, /* dropped by 429 * BPF_PROG_TYPE_CGROUP_SKB 430 * eBPF program 431 */ 432 SKB_DROP_REASON_IPV6DISABLED, /* IPv6 is disabled on the device */ 433 SKB_DROP_REASON_NEIGH_CREATEFAIL, /* failed to create neigh 434 * entry 435 */ 436 SKB_DROP_REASON_NEIGH_FAILED, /* neigh entry in failed state */ 437 SKB_DROP_REASON_NEIGH_QUEUEFULL, /* arp_queue for neigh 438 * entry is full 439 */ 440 SKB_DROP_REASON_NEIGH_DEAD, /* neigh entry is dead */ 441 SKB_DROP_REASON_TC_EGRESS, /* dropped in TC egress HOOK */ 442 SKB_DROP_REASON_QDISC_DROP, /* dropped by qdisc when packet 443 * outputting (failed to enqueue to 444 * current qdisc) 445 */ 446 SKB_DROP_REASON_CPU_BACKLOG, /* failed to enqueue the skb to 447 * the per CPU backlog queue. This 448 * can be caused by backlog queue 449 * full (see netdev_max_backlog in 450 * net.rst) or RPS flow limit 451 */ 452 SKB_DROP_REASON_XDP, /* dropped by XDP in input path */ 453 SKB_DROP_REASON_TC_INGRESS, /* dropped in TC ingress HOOK */ 454 SKB_DROP_REASON_UNHANDLED_PROTO, /* protocol not implemented 455 * or not supported 456 */ 457 SKB_DROP_REASON_SKB_CSUM, /* sk_buff checksum computation 458 * error 459 */ 460 SKB_DROP_REASON_SKB_GSO_SEG, /* gso segmentation error */ 461 SKB_DROP_REASON_SKB_UCOPY_FAULT, /* failed to copy data from 462 * user space, e.g., via 463 * zerocopy_sg_from_iter() 464 * or skb_orphan_frags_rx() 465 */ 466 SKB_DROP_REASON_DEV_HDR, /* device driver specific 467 * header/metadata is invalid 468 */ 469 /* the device is not ready to xmit/recv due to any of its data 470 * structure that is not up/ready/initialized, e.g., the IFF_UP is 471 * not set, or driver specific tun->tfiles[txq] is not initialized 472 */ 473 SKB_DROP_REASON_DEV_READY, 474 SKB_DROP_REASON_FULL_RING, /* ring buffer is full */ 475 SKB_DROP_REASON_NOMEM, /* error due to OOM */ 476 SKB_DROP_REASON_HDR_TRUNC, /* failed to trunc/extract the header 477 * from networking data, e.g., failed 478 * to pull the protocol header from 479 * frags via pskb_may_pull() 480 */ 481 SKB_DROP_REASON_TAP_FILTER, /* dropped by (ebpf) filter directly 482 * attached to tun/tap, e.g., via 483 * TUNSETFILTEREBPF 484 */ 485 SKB_DROP_REASON_TAP_TXFILTER, /* dropped by tx filter implemented 486 * at tun/tap, e.g., check_filter() 487 */ 488 SKB_DROP_REASON_ICMP_CSUM, /* ICMP checksum error */ 489 SKB_DROP_REASON_INVALID_PROTO, /* the packet doesn't follow RFC 490 * 2211, such as a broadcasts 491 * ICMP_TIMESTAMP 492 */ 493 SKB_DROP_REASON_IP_INADDRERRORS, /* host unreachable, corresponding 494 * to IPSTATS_MIB_INADDRERRORS 495 */ 496 SKB_DROP_REASON_IP_INNOROUTES, /* network unreachable, corresponding 497 * to IPSTATS_MIB_INADDRERRORS 498 */ 499 SKB_DROP_REASON_PKT_TOO_BIG, /* packet size is too big (maybe exceed 500 * the MTU) 501 */ 502 SKB_DROP_REASON_MAX, 503 }; 504 505 #define SKB_DR_INIT(name, reason) \ 506 enum skb_drop_reason name = SKB_DROP_REASON_##reason 507 #define SKB_DR(name) \ 508 SKB_DR_INIT(name, NOT_SPECIFIED) 509 #define SKB_DR_SET(name, reason) \ 510 (name = SKB_DROP_REASON_##reason) 511 #define SKB_DR_OR(name, reason) \ 512 do { \ 513 if (name == SKB_DROP_REASON_NOT_SPECIFIED || \ 514 name == SKB_NOT_DROPPED_YET) \ 515 SKB_DR_SET(name, reason); \ 516 } while (0) 517 518 /* To allow 64K frame to be packed as single skb without frag_list we 519 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for 520 * buffers which do not start on a page boundary. 521 * 522 * Since GRO uses frags we allocate at least 16 regardless of page 523 * size. 524 */ 525 #if (65536/PAGE_SIZE + 1) < 16 526 #define MAX_SKB_FRAGS 16UL 527 #else 528 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) 529 #endif 530 extern int sysctl_max_skb_frags; 531 532 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to 533 * segment using its current segmentation instead. 534 */ 535 #define GSO_BY_FRAGS 0xFFFF 536 537 typedef struct bio_vec skb_frag_t; 538 539 /** 540 * skb_frag_size() - Returns the size of a skb fragment 541 * @frag: skb fragment 542 */ 543 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 544 { 545 return frag->bv_len; 546 } 547 548 /** 549 * skb_frag_size_set() - Sets the size of a skb fragment 550 * @frag: skb fragment 551 * @size: size of fragment 552 */ 553 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 554 { 555 frag->bv_len = size; 556 } 557 558 /** 559 * skb_frag_size_add() - Increments the size of a skb fragment by @delta 560 * @frag: skb fragment 561 * @delta: value to add 562 */ 563 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 564 { 565 frag->bv_len += delta; 566 } 567 568 /** 569 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta 570 * @frag: skb fragment 571 * @delta: value to subtract 572 */ 573 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 574 { 575 frag->bv_len -= delta; 576 } 577 578 /** 579 * skb_frag_must_loop - Test if %p is a high memory page 580 * @p: fragment's page 581 */ 582 static inline bool skb_frag_must_loop(struct page *p) 583 { 584 #if defined(CONFIG_HIGHMEM) 585 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p)) 586 return true; 587 #endif 588 return false; 589 } 590 591 /** 592 * skb_frag_foreach_page - loop over pages in a fragment 593 * 594 * @f: skb frag to operate on 595 * @f_off: offset from start of f->bv_page 596 * @f_len: length from f_off to loop over 597 * @p: (temp var) current page 598 * @p_off: (temp var) offset from start of current page, 599 * non-zero only on first page. 600 * @p_len: (temp var) length in current page, 601 * < PAGE_SIZE only on first and last page. 602 * @copied: (temp var) length so far, excluding current p_len. 603 * 604 * A fragment can hold a compound page, in which case per-page 605 * operations, notably kmap_atomic, must be called for each 606 * regular page. 607 */ 608 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \ 609 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \ 610 p_off = (f_off) & (PAGE_SIZE - 1), \ 611 p_len = skb_frag_must_loop(p) ? \ 612 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \ 613 copied = 0; \ 614 copied < f_len; \ 615 copied += p_len, p++, p_off = 0, \ 616 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \ 617 618 #define HAVE_HW_TIME_STAMP 619 620 /** 621 * struct skb_shared_hwtstamps - hardware time stamps 622 * @hwtstamp: hardware time stamp transformed into duration 623 * since arbitrary point in time 624 * @netdev_data: address/cookie of network device driver used as 625 * reference to actual hardware time stamp 626 * 627 * Software time stamps generated by ktime_get_real() are stored in 628 * skb->tstamp. 629 * 630 * hwtstamps can only be compared against other hwtstamps from 631 * the same device. 632 * 633 * This structure is attached to packets as part of the 634 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 635 */ 636 struct skb_shared_hwtstamps { 637 union { 638 ktime_t hwtstamp; 639 void *netdev_data; 640 }; 641 }; 642 643 /* Definitions for tx_flags in struct skb_shared_info */ 644 enum { 645 /* generate hardware time stamp */ 646 SKBTX_HW_TSTAMP = 1 << 0, 647 648 /* generate software time stamp when queueing packet to NIC */ 649 SKBTX_SW_TSTAMP = 1 << 1, 650 651 /* device driver is going to provide hardware time stamp */ 652 SKBTX_IN_PROGRESS = 1 << 2, 653 654 /* generate hardware time stamp based on cycles if supported */ 655 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, 656 657 /* generate wifi status information (where possible) */ 658 SKBTX_WIFI_STATUS = 1 << 4, 659 660 /* determine hardware time stamp based on time or cycles */ 661 SKBTX_HW_TSTAMP_NETDEV = 1 << 5, 662 663 /* generate software time stamp when entering packet scheduling */ 664 SKBTX_SCHED_TSTAMP = 1 << 6, 665 }; 666 667 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ 668 SKBTX_SCHED_TSTAMP) 669 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ 670 SKBTX_HW_TSTAMP_USE_CYCLES | \ 671 SKBTX_ANY_SW_TSTAMP) 672 673 /* Definitions for flags in struct skb_shared_info */ 674 enum { 675 /* use zcopy routines */ 676 SKBFL_ZEROCOPY_ENABLE = BIT(0), 677 678 /* This indicates at least one fragment might be overwritten 679 * (as in vmsplice(), sendfile() ...) 680 * If we need to compute a TX checksum, we'll need to copy 681 * all frags to avoid possible bad checksum 682 */ 683 SKBFL_SHARED_FRAG = BIT(1), 684 685 /* segment contains only zerocopy data and should not be 686 * charged to the kernel memory. 687 */ 688 SKBFL_PURE_ZEROCOPY = BIT(2), 689 }; 690 691 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG) 692 #define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY) 693 694 /* 695 * The callback notifies userspace to release buffers when skb DMA is done in 696 * lower device, the skb last reference should be 0 when calling this. 697 * The zerocopy_success argument is true if zero copy transmit occurred, 698 * false on data copy or out of memory error caused by data copy attempt. 699 * The ctx field is used to track device context. 700 * The desc field is used to track userspace buffer index. 701 */ 702 struct ubuf_info { 703 void (*callback)(struct sk_buff *, struct ubuf_info *, 704 bool zerocopy_success); 705 union { 706 struct { 707 unsigned long desc; 708 void *ctx; 709 }; 710 struct { 711 u32 id; 712 u16 len; 713 u16 zerocopy:1; 714 u32 bytelen; 715 }; 716 }; 717 refcount_t refcnt; 718 u8 flags; 719 720 struct mmpin { 721 struct user_struct *user; 722 unsigned int num_pg; 723 } mmp; 724 }; 725 726 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg)) 727 728 int mm_account_pinned_pages(struct mmpin *mmp, size_t size); 729 void mm_unaccount_pinned_pages(struct mmpin *mmp); 730 731 /* This data is invariant across clones and lives at 732 * the end of the header data, ie. at skb->end. 733 */ 734 struct skb_shared_info { 735 __u8 flags; 736 __u8 meta_len; 737 __u8 nr_frags; 738 __u8 tx_flags; 739 unsigned short gso_size; 740 /* Warning: this field is not always filled in (UFO)! */ 741 unsigned short gso_segs; 742 struct sk_buff *frag_list; 743 struct skb_shared_hwtstamps hwtstamps; 744 unsigned int gso_type; 745 u32 tskey; 746 747 /* 748 * Warning : all fields before dataref are cleared in __alloc_skb() 749 */ 750 atomic_t dataref; 751 unsigned int xdp_frags_size; 752 753 /* Intermediate layers must ensure that destructor_arg 754 * remains valid until skb destructor */ 755 void * destructor_arg; 756 757 /* must be last field, see pskb_expand_head() */ 758 skb_frag_t frags[MAX_SKB_FRAGS]; 759 }; 760 761 /** 762 * DOC: dataref and headerless skbs 763 * 764 * Transport layers send out clones of payload skbs they hold for 765 * retransmissions. To allow lower layers of the stack to prepend their headers 766 * we split &skb_shared_info.dataref into two halves. 767 * The lower 16 bits count the overall number of references. 768 * The higher 16 bits indicate how many of the references are payload-only. 769 * skb_header_cloned() checks if skb is allowed to add / write the headers. 770 * 771 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr 772 * (via __skb_header_release()). Any clone created from marked skb will get 773 * &sk_buff.hdr_len populated with the available headroom. 774 * If there's the only clone in existence it's able to modify the headroom 775 * at will. The sequence of calls inside the transport layer is:: 776 * 777 * <alloc skb> 778 * skb_reserve() 779 * __skb_header_release() 780 * skb_clone() 781 * // send the clone down the stack 782 * 783 * This is not a very generic construct and it depends on the transport layers 784 * doing the right thing. In practice there's usually only one payload-only skb. 785 * Having multiple payload-only skbs with different lengths of hdr_len is not 786 * possible. The payload-only skbs should never leave their owner. 787 */ 788 #define SKB_DATAREF_SHIFT 16 789 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 790 791 792 enum { 793 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ 794 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ 795 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ 796 }; 797 798 enum { 799 SKB_GSO_TCPV4 = 1 << 0, 800 801 /* This indicates the skb is from an untrusted source. */ 802 SKB_GSO_DODGY = 1 << 1, 803 804 /* This indicates the tcp segment has CWR set. */ 805 SKB_GSO_TCP_ECN = 1 << 2, 806 807 SKB_GSO_TCP_FIXEDID = 1 << 3, 808 809 SKB_GSO_TCPV6 = 1 << 4, 810 811 SKB_GSO_FCOE = 1 << 5, 812 813 SKB_GSO_GRE = 1 << 6, 814 815 SKB_GSO_GRE_CSUM = 1 << 7, 816 817 SKB_GSO_IPXIP4 = 1 << 8, 818 819 SKB_GSO_IPXIP6 = 1 << 9, 820 821 SKB_GSO_UDP_TUNNEL = 1 << 10, 822 823 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, 824 825 SKB_GSO_PARTIAL = 1 << 12, 826 827 SKB_GSO_TUNNEL_REMCSUM = 1 << 13, 828 829 SKB_GSO_SCTP = 1 << 14, 830 831 SKB_GSO_ESP = 1 << 15, 832 833 SKB_GSO_UDP = 1 << 16, 834 835 SKB_GSO_UDP_L4 = 1 << 17, 836 837 SKB_GSO_FRAGLIST = 1 << 18, 838 }; 839 840 #if BITS_PER_LONG > 32 841 #define NET_SKBUFF_DATA_USES_OFFSET 1 842 #endif 843 844 #ifdef NET_SKBUFF_DATA_USES_OFFSET 845 typedef unsigned int sk_buff_data_t; 846 #else 847 typedef unsigned char *sk_buff_data_t; 848 #endif 849 850 /** 851 * DOC: Basic sk_buff geometry 852 * 853 * struct sk_buff itself is a metadata structure and does not hold any packet 854 * data. All the data is held in associated buffers. 855 * 856 * &sk_buff.head points to the main "head" buffer. The head buffer is divided 857 * into two parts: 858 * 859 * - data buffer, containing headers and sometimes payload; 860 * this is the part of the skb operated on by the common helpers 861 * such as skb_put() or skb_pull(); 862 * - shared info (struct skb_shared_info) which holds an array of pointers 863 * to read-only data in the (page, offset, length) format. 864 * 865 * Optionally &skb_shared_info.frag_list may point to another skb. 866 * 867 * Basic diagram may look like this:: 868 * 869 * --------------- 870 * | sk_buff | 871 * --------------- 872 * ,--------------------------- + head 873 * / ,----------------- + data 874 * / / ,----------- + tail 875 * | | | , + end 876 * | | | | 877 * v v v v 878 * ----------------------------------------------- 879 * | headroom | data | tailroom | skb_shared_info | 880 * ----------------------------------------------- 881 * + [page frag] 882 * + [page frag] 883 * + [page frag] 884 * + [page frag] --------- 885 * + frag_list --> | sk_buff | 886 * --------- 887 * 888 */ 889 890 /** 891 * struct sk_buff - socket buffer 892 * @next: Next buffer in list 893 * @prev: Previous buffer in list 894 * @tstamp: Time we arrived/left 895 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point 896 * for retransmit timer 897 * @rbnode: RB tree node, alternative to next/prev for netem/tcp 898 * @list: queue head 899 * @ll_node: anchor in an llist (eg socket defer_list) 900 * @sk: Socket we are owned by 901 * @ip_defrag_offset: (aka @sk) alternate use of @sk, used in 902 * fragmentation management 903 * @dev: Device we arrived on/are leaving by 904 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL 905 * @cb: Control buffer. Free for use by every layer. Put private vars here 906 * @_skb_refdst: destination entry (with norefcount bit) 907 * @sp: the security path, used for xfrm 908 * @len: Length of actual data 909 * @data_len: Data length 910 * @mac_len: Length of link layer header 911 * @hdr_len: writable header length of cloned skb 912 * @csum: Checksum (must include start/offset pair) 913 * @csum_start: Offset from skb->head where checksumming should start 914 * @csum_offset: Offset from csum_start where checksum should be stored 915 * @priority: Packet queueing priority 916 * @ignore_df: allow local fragmentation 917 * @cloned: Head may be cloned (check refcnt to be sure) 918 * @ip_summed: Driver fed us an IP checksum 919 * @nohdr: Payload reference only, must not modify header 920 * @pkt_type: Packet class 921 * @fclone: skbuff clone status 922 * @ipvs_property: skbuff is owned by ipvs 923 * @inner_protocol_type: whether the inner protocol is 924 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO 925 * @remcsum_offload: remote checksum offload is enabled 926 * @offload_fwd_mark: Packet was L2-forwarded in hardware 927 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware 928 * @tc_skip_classify: do not classify packet. set by IFB device 929 * @tc_at_ingress: used within tc_classify to distinguish in/egress 930 * @redirected: packet was redirected by packet classifier 931 * @from_ingress: packet was redirected from the ingress path 932 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h 933 * @peeked: this packet has been seen already, so stats have been 934 * done for it, don't do them again 935 * @nf_trace: netfilter packet trace flag 936 * @protocol: Packet protocol from driver 937 * @destructor: Destruct function 938 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue) 939 * @_sk_redir: socket redirection information for skmsg 940 * @_nfct: Associated connection, if any (with nfctinfo bits) 941 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 942 * @skb_iif: ifindex of device we arrived on 943 * @tc_index: Traffic control index 944 * @hash: the packet hash 945 * @queue_mapping: Queue mapping for multiqueue devices 946 * @head_frag: skb was allocated from page fragments, 947 * not allocated by kmalloc() or vmalloc(). 948 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves 949 * @pp_recycle: mark the packet for recycling instead of freeing (implies 950 * page_pool support on driver) 951 * @active_extensions: active extensions (skb_ext_id types) 952 * @ndisc_nodetype: router type (from link layer) 953 * @ooo_okay: allow the mapping of a socket to a queue to be changed 954 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport 955 * ports. 956 * @sw_hash: indicates hash was computed in software stack 957 * @wifi_acked_valid: wifi_acked was set 958 * @wifi_acked: whether frame was acked on wifi or not 959 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 960 * @encapsulation: indicates the inner headers in the skbuff are valid 961 * @encap_hdr_csum: software checksum is needed 962 * @csum_valid: checksum is already valid 963 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL 964 * @csum_complete_sw: checksum was completed by software 965 * @csum_level: indicates the number of consecutive checksums found in 966 * the packet minus one that have been verified as 967 * CHECKSUM_UNNECESSARY (max 3) 968 * @dst_pending_confirm: need to confirm neighbour 969 * @decrypted: Decrypted SKB 970 * @slow_gro: state present at GRO time, slower prepare step required 971 * @mono_delivery_time: When set, skb->tstamp has the 972 * delivery_time in mono clock base (i.e. EDT). Otherwise, the 973 * skb->tstamp has the (rcv) timestamp at ingress and 974 * delivery_time at egress. 975 * @napi_id: id of the NAPI struct this skb came from 976 * @sender_cpu: (aka @napi_id) source CPU in XPS 977 * @alloc_cpu: CPU which did the skb allocation. 978 * @secmark: security marking 979 * @mark: Generic packet mark 980 * @reserved_tailroom: (aka @mark) number of bytes of free space available 981 * at the tail of an sk_buff 982 * @vlan_present: VLAN tag is present 983 * @vlan_proto: vlan encapsulation protocol 984 * @vlan_tci: vlan tag control information 985 * @inner_protocol: Protocol (encapsulation) 986 * @inner_ipproto: (aka @inner_protocol) stores ipproto when 987 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO; 988 * @inner_transport_header: Inner transport layer header (encapsulation) 989 * @inner_network_header: Network layer header (encapsulation) 990 * @inner_mac_header: Link layer header (encapsulation) 991 * @transport_header: Transport layer header 992 * @network_header: Network layer header 993 * @mac_header: Link layer header 994 * @kcov_handle: KCOV remote handle for remote coverage collection 995 * @tail: Tail pointer 996 * @end: End pointer 997 * @head: Head of buffer 998 * @data: Data head pointer 999 * @truesize: Buffer size 1000 * @users: User count - see {datagram,tcp}.c 1001 * @extensions: allocated extensions, valid if active_extensions is nonzero 1002 */ 1003 1004 struct sk_buff { 1005 union { 1006 struct { 1007 /* These two members must be first to match sk_buff_head. */ 1008 struct sk_buff *next; 1009 struct sk_buff *prev; 1010 1011 union { 1012 struct net_device *dev; 1013 /* Some protocols might use this space to store information, 1014 * while device pointer would be NULL. 1015 * UDP receive path is one user. 1016 */ 1017 unsigned long dev_scratch; 1018 }; 1019 }; 1020 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */ 1021 struct list_head list; 1022 struct llist_node ll_node; 1023 }; 1024 1025 union { 1026 struct sock *sk; 1027 int ip_defrag_offset; 1028 }; 1029 1030 union { 1031 ktime_t tstamp; 1032 u64 skb_mstamp_ns; /* earliest departure time */ 1033 }; 1034 /* 1035 * This is the control buffer. It is free to use for every 1036 * layer. Please put your private variables there. If you 1037 * want to keep them across layers you have to do a skb_clone() 1038 * first. This is owned by whoever has the skb queued ATM. 1039 */ 1040 char cb[48] __aligned(8); 1041 1042 union { 1043 struct { 1044 unsigned long _skb_refdst; 1045 void (*destructor)(struct sk_buff *skb); 1046 }; 1047 struct list_head tcp_tsorted_anchor; 1048 #ifdef CONFIG_NET_SOCK_MSG 1049 unsigned long _sk_redir; 1050 #endif 1051 }; 1052 1053 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 1054 unsigned long _nfct; 1055 #endif 1056 unsigned int len, 1057 data_len; 1058 __u16 mac_len, 1059 hdr_len; 1060 1061 /* Following fields are _not_ copied in __copy_skb_header() 1062 * Note that queue_mapping is here mostly to fill a hole. 1063 */ 1064 __u16 queue_mapping; 1065 1066 /* if you move cloned around you also must adapt those constants */ 1067 #ifdef __BIG_ENDIAN_BITFIELD 1068 #define CLONED_MASK (1 << 7) 1069 #else 1070 #define CLONED_MASK 1 1071 #endif 1072 #define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset) 1073 1074 /* private: */ 1075 __u8 __cloned_offset[0]; 1076 /* public: */ 1077 __u8 cloned:1, 1078 nohdr:1, 1079 fclone:2, 1080 peeked:1, 1081 head_frag:1, 1082 pfmemalloc:1, 1083 pp_recycle:1; /* page_pool recycle indicator */ 1084 #ifdef CONFIG_SKB_EXTENSIONS 1085 __u8 active_extensions; 1086 #endif 1087 1088 /* Fields enclosed in headers group are copied 1089 * using a single memcpy() in __copy_skb_header() 1090 */ 1091 struct_group(headers, 1092 1093 /* private: */ 1094 __u8 __pkt_type_offset[0]; 1095 /* public: */ 1096 __u8 pkt_type:3; /* see PKT_TYPE_MAX */ 1097 __u8 ignore_df:1; 1098 __u8 nf_trace:1; 1099 __u8 ip_summed:2; 1100 __u8 ooo_okay:1; 1101 1102 __u8 l4_hash:1; 1103 __u8 sw_hash:1; 1104 __u8 wifi_acked_valid:1; 1105 __u8 wifi_acked:1; 1106 __u8 no_fcs:1; 1107 /* Indicates the inner headers are valid in the skbuff. */ 1108 __u8 encapsulation:1; 1109 __u8 encap_hdr_csum:1; 1110 __u8 csum_valid:1; 1111 1112 /* private: */ 1113 __u8 __pkt_vlan_present_offset[0]; 1114 /* public: */ 1115 __u8 vlan_present:1; /* See PKT_VLAN_PRESENT_BIT */ 1116 __u8 csum_complete_sw:1; 1117 __u8 csum_level:2; 1118 __u8 dst_pending_confirm:1; 1119 __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */ 1120 #ifdef CONFIG_NET_CLS_ACT 1121 __u8 tc_skip_classify:1; 1122 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */ 1123 #endif 1124 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1125 __u8 ndisc_nodetype:2; 1126 #endif 1127 1128 __u8 ipvs_property:1; 1129 __u8 inner_protocol_type:1; 1130 __u8 remcsum_offload:1; 1131 #ifdef CONFIG_NET_SWITCHDEV 1132 __u8 offload_fwd_mark:1; 1133 __u8 offload_l3_fwd_mark:1; 1134 #endif 1135 __u8 redirected:1; 1136 #ifdef CONFIG_NET_REDIRECT 1137 __u8 from_ingress:1; 1138 #endif 1139 #ifdef CONFIG_NETFILTER_SKIP_EGRESS 1140 __u8 nf_skip_egress:1; 1141 #endif 1142 #ifdef CONFIG_TLS_DEVICE 1143 __u8 decrypted:1; 1144 #endif 1145 __u8 slow_gro:1; 1146 __u8 csum_not_inet:1; 1147 1148 #ifdef CONFIG_NET_SCHED 1149 __u16 tc_index; /* traffic control index */ 1150 #endif 1151 1152 union { 1153 __wsum csum; 1154 struct { 1155 __u16 csum_start; 1156 __u16 csum_offset; 1157 }; 1158 }; 1159 __u32 priority; 1160 int skb_iif; 1161 __u32 hash; 1162 __be16 vlan_proto; 1163 __u16 vlan_tci; 1164 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS) 1165 union { 1166 unsigned int napi_id; 1167 unsigned int sender_cpu; 1168 }; 1169 #endif 1170 u16 alloc_cpu; 1171 #ifdef CONFIG_NETWORK_SECMARK 1172 __u32 secmark; 1173 #endif 1174 1175 union { 1176 __u32 mark; 1177 __u32 reserved_tailroom; 1178 }; 1179 1180 union { 1181 __be16 inner_protocol; 1182 __u8 inner_ipproto; 1183 }; 1184 1185 __u16 inner_transport_header; 1186 __u16 inner_network_header; 1187 __u16 inner_mac_header; 1188 1189 __be16 protocol; 1190 __u16 transport_header; 1191 __u16 network_header; 1192 __u16 mac_header; 1193 1194 #ifdef CONFIG_KCOV 1195 u64 kcov_handle; 1196 #endif 1197 1198 ); /* end headers group */ 1199 1200 /* These elements must be at the end, see alloc_skb() for details. */ 1201 sk_buff_data_t tail; 1202 sk_buff_data_t end; 1203 unsigned char *head, 1204 *data; 1205 unsigned int truesize; 1206 refcount_t users; 1207 1208 #ifdef CONFIG_SKB_EXTENSIONS 1209 /* only useable after checking ->active_extensions != 0 */ 1210 struct skb_ext *extensions; 1211 #endif 1212 }; 1213 1214 /* if you move pkt_type around you also must adapt those constants */ 1215 #ifdef __BIG_ENDIAN_BITFIELD 1216 #define PKT_TYPE_MAX (7 << 5) 1217 #else 1218 #define PKT_TYPE_MAX 7 1219 #endif 1220 #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset) 1221 1222 /* if you move pkt_vlan_present, tc_at_ingress, or mono_delivery_time 1223 * around, you also must adapt these constants. 1224 */ 1225 #ifdef __BIG_ENDIAN_BITFIELD 1226 #define PKT_VLAN_PRESENT_BIT 7 1227 #define TC_AT_INGRESS_MASK (1 << 0) 1228 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 2) 1229 #else 1230 #define PKT_VLAN_PRESENT_BIT 0 1231 #define TC_AT_INGRESS_MASK (1 << 7) 1232 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 5) 1233 #endif 1234 #define PKT_VLAN_PRESENT_OFFSET offsetof(struct sk_buff, __pkt_vlan_present_offset) 1235 1236 #ifdef __KERNEL__ 1237 /* 1238 * Handling routines are only of interest to the kernel 1239 */ 1240 1241 #define SKB_ALLOC_FCLONE 0x01 1242 #define SKB_ALLOC_RX 0x02 1243 #define SKB_ALLOC_NAPI 0x04 1244 1245 /** 1246 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves 1247 * @skb: buffer 1248 */ 1249 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 1250 { 1251 return unlikely(skb->pfmemalloc); 1252 } 1253 1254 /* 1255 * skb might have a dst pointer attached, refcounted or not. 1256 * _skb_refdst low order bit is set if refcount was _not_ taken 1257 */ 1258 #define SKB_DST_NOREF 1UL 1259 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 1260 1261 /** 1262 * skb_dst - returns skb dst_entry 1263 * @skb: buffer 1264 * 1265 * Returns skb dst_entry, regardless of reference taken or not. 1266 */ 1267 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 1268 { 1269 /* If refdst was not refcounted, check we still are in a 1270 * rcu_read_lock section 1271 */ 1272 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 1273 !rcu_read_lock_held() && 1274 !rcu_read_lock_bh_held()); 1275 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 1276 } 1277 1278 /** 1279 * skb_dst_set - sets skb dst 1280 * @skb: buffer 1281 * @dst: dst entry 1282 * 1283 * Sets skb dst, assuming a reference was taken on dst and should 1284 * be released by skb_dst_drop() 1285 */ 1286 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 1287 { 1288 skb->slow_gro |= !!dst; 1289 skb->_skb_refdst = (unsigned long)dst; 1290 } 1291 1292 /** 1293 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 1294 * @skb: buffer 1295 * @dst: dst entry 1296 * 1297 * Sets skb dst, assuming a reference was not taken on dst. 1298 * If dst entry is cached, we do not take reference and dst_release 1299 * will be avoided by refdst_drop. If dst entry is not cached, we take 1300 * reference, so that last dst_release can destroy the dst immediately. 1301 */ 1302 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 1303 { 1304 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 1305 skb->slow_gro |= !!dst; 1306 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 1307 } 1308 1309 /** 1310 * skb_dst_is_noref - Test if skb dst isn't refcounted 1311 * @skb: buffer 1312 */ 1313 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 1314 { 1315 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 1316 } 1317 1318 /** 1319 * skb_rtable - Returns the skb &rtable 1320 * @skb: buffer 1321 */ 1322 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 1323 { 1324 return (struct rtable *)skb_dst(skb); 1325 } 1326 1327 /* For mangling skb->pkt_type from user space side from applications 1328 * such as nft, tc, etc, we only allow a conservative subset of 1329 * possible pkt_types to be set. 1330 */ 1331 static inline bool skb_pkt_type_ok(u32 ptype) 1332 { 1333 return ptype <= PACKET_OTHERHOST; 1334 } 1335 1336 /** 1337 * skb_napi_id - Returns the skb's NAPI id 1338 * @skb: buffer 1339 */ 1340 static inline unsigned int skb_napi_id(const struct sk_buff *skb) 1341 { 1342 #ifdef CONFIG_NET_RX_BUSY_POLL 1343 return skb->napi_id; 1344 #else 1345 return 0; 1346 #endif 1347 } 1348 1349 /** 1350 * skb_unref - decrement the skb's reference count 1351 * @skb: buffer 1352 * 1353 * Returns true if we can free the skb. 1354 */ 1355 static inline bool skb_unref(struct sk_buff *skb) 1356 { 1357 if (unlikely(!skb)) 1358 return false; 1359 if (likely(refcount_read(&skb->users) == 1)) 1360 smp_rmb(); 1361 else if (likely(!refcount_dec_and_test(&skb->users))) 1362 return false; 1363 1364 return true; 1365 } 1366 1367 void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason); 1368 1369 /** 1370 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason 1371 * @skb: buffer to free 1372 */ 1373 static inline void kfree_skb(struct sk_buff *skb) 1374 { 1375 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED); 1376 } 1377 1378 void skb_release_head_state(struct sk_buff *skb); 1379 void kfree_skb_list_reason(struct sk_buff *segs, 1380 enum skb_drop_reason reason); 1381 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt); 1382 void skb_tx_error(struct sk_buff *skb); 1383 1384 static inline void kfree_skb_list(struct sk_buff *segs) 1385 { 1386 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED); 1387 } 1388 1389 #ifdef CONFIG_TRACEPOINTS 1390 void consume_skb(struct sk_buff *skb); 1391 #else 1392 static inline void consume_skb(struct sk_buff *skb) 1393 { 1394 return kfree_skb(skb); 1395 } 1396 #endif 1397 1398 void __consume_stateless_skb(struct sk_buff *skb); 1399 void __kfree_skb(struct sk_buff *skb); 1400 extern struct kmem_cache *skbuff_head_cache; 1401 1402 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 1403 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 1404 bool *fragstolen, int *delta_truesize); 1405 1406 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 1407 int node); 1408 struct sk_buff *__build_skb(void *data, unsigned int frag_size); 1409 struct sk_buff *build_skb(void *data, unsigned int frag_size); 1410 struct sk_buff *build_skb_around(struct sk_buff *skb, 1411 void *data, unsigned int frag_size); 1412 void skb_attempt_defer_free(struct sk_buff *skb); 1413 1414 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size); 1415 1416 /** 1417 * alloc_skb - allocate a network buffer 1418 * @size: size to allocate 1419 * @priority: allocation mask 1420 * 1421 * This function is a convenient wrapper around __alloc_skb(). 1422 */ 1423 static inline struct sk_buff *alloc_skb(unsigned int size, 1424 gfp_t priority) 1425 { 1426 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 1427 } 1428 1429 struct sk_buff *alloc_skb_with_frags(unsigned long header_len, 1430 unsigned long data_len, 1431 int max_page_order, 1432 int *errcode, 1433 gfp_t gfp_mask); 1434 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first); 1435 1436 /* Layout of fast clones : [skb1][skb2][fclone_ref] */ 1437 struct sk_buff_fclones { 1438 struct sk_buff skb1; 1439 1440 struct sk_buff skb2; 1441 1442 refcount_t fclone_ref; 1443 }; 1444 1445 /** 1446 * skb_fclone_busy - check if fclone is busy 1447 * @sk: socket 1448 * @skb: buffer 1449 * 1450 * Returns true if skb is a fast clone, and its clone is not freed. 1451 * Some drivers call skb_orphan() in their ndo_start_xmit(), 1452 * so we also check that this didnt happen. 1453 */ 1454 static inline bool skb_fclone_busy(const struct sock *sk, 1455 const struct sk_buff *skb) 1456 { 1457 const struct sk_buff_fclones *fclones; 1458 1459 fclones = container_of(skb, struct sk_buff_fclones, skb1); 1460 1461 return skb->fclone == SKB_FCLONE_ORIG && 1462 refcount_read(&fclones->fclone_ref) > 1 && 1463 READ_ONCE(fclones->skb2.sk) == sk; 1464 } 1465 1466 /** 1467 * alloc_skb_fclone - allocate a network buffer from fclone cache 1468 * @size: size to allocate 1469 * @priority: allocation mask 1470 * 1471 * This function is a convenient wrapper around __alloc_skb(). 1472 */ 1473 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 1474 gfp_t priority) 1475 { 1476 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 1477 } 1478 1479 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 1480 void skb_headers_offset_update(struct sk_buff *skb, int off); 1481 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 1482 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 1483 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old); 1484 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 1485 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, 1486 gfp_t gfp_mask, bool fclone); 1487 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, 1488 gfp_t gfp_mask) 1489 { 1490 return __pskb_copy_fclone(skb, headroom, gfp_mask, false); 1491 } 1492 1493 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 1494 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 1495 unsigned int headroom); 1496 struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom); 1497 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 1498 int newtailroom, gfp_t priority); 1499 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, 1500 int offset, int len); 1501 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, 1502 int offset, int len); 1503 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 1504 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error); 1505 1506 /** 1507 * skb_pad - zero pad the tail of an skb 1508 * @skb: buffer to pad 1509 * @pad: space to pad 1510 * 1511 * Ensure that a buffer is followed by a padding area that is zero 1512 * filled. Used by network drivers which may DMA or transfer data 1513 * beyond the buffer end onto the wire. 1514 * 1515 * May return error in out of memory cases. The skb is freed on error. 1516 */ 1517 static inline int skb_pad(struct sk_buff *skb, int pad) 1518 { 1519 return __skb_pad(skb, pad, true); 1520 } 1521 #define dev_kfree_skb(a) consume_skb(a) 1522 1523 int skb_append_pagefrags(struct sk_buff *skb, struct page *page, 1524 int offset, size_t size); 1525 1526 struct skb_seq_state { 1527 __u32 lower_offset; 1528 __u32 upper_offset; 1529 __u32 frag_idx; 1530 __u32 stepped_offset; 1531 struct sk_buff *root_skb; 1532 struct sk_buff *cur_skb; 1533 __u8 *frag_data; 1534 __u32 frag_off; 1535 }; 1536 1537 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 1538 unsigned int to, struct skb_seq_state *st); 1539 unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 1540 struct skb_seq_state *st); 1541 void skb_abort_seq_read(struct skb_seq_state *st); 1542 1543 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 1544 unsigned int to, struct ts_config *config); 1545 1546 /* 1547 * Packet hash types specify the type of hash in skb_set_hash. 1548 * 1549 * Hash types refer to the protocol layer addresses which are used to 1550 * construct a packet's hash. The hashes are used to differentiate or identify 1551 * flows of the protocol layer for the hash type. Hash types are either 1552 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 1553 * 1554 * Properties of hashes: 1555 * 1556 * 1) Two packets in different flows have different hash values 1557 * 2) Two packets in the same flow should have the same hash value 1558 * 1559 * A hash at a higher layer is considered to be more specific. A driver should 1560 * set the most specific hash possible. 1561 * 1562 * A driver cannot indicate a more specific hash than the layer at which a hash 1563 * was computed. For instance an L3 hash cannot be set as an L4 hash. 1564 * 1565 * A driver may indicate a hash level which is less specific than the 1566 * actual layer the hash was computed on. For instance, a hash computed 1567 * at L4 may be considered an L3 hash. This should only be done if the 1568 * driver can't unambiguously determine that the HW computed the hash at 1569 * the higher layer. Note that the "should" in the second property above 1570 * permits this. 1571 */ 1572 enum pkt_hash_types { 1573 PKT_HASH_TYPE_NONE, /* Undefined type */ 1574 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 1575 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 1576 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 1577 }; 1578 1579 static inline void skb_clear_hash(struct sk_buff *skb) 1580 { 1581 skb->hash = 0; 1582 skb->sw_hash = 0; 1583 skb->l4_hash = 0; 1584 } 1585 1586 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 1587 { 1588 if (!skb->l4_hash) 1589 skb_clear_hash(skb); 1590 } 1591 1592 static inline void 1593 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4) 1594 { 1595 skb->l4_hash = is_l4; 1596 skb->sw_hash = is_sw; 1597 skb->hash = hash; 1598 } 1599 1600 static inline void 1601 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 1602 { 1603 /* Used by drivers to set hash from HW */ 1604 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4); 1605 } 1606 1607 static inline void 1608 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4) 1609 { 1610 __skb_set_hash(skb, hash, true, is_l4); 1611 } 1612 1613 void __skb_get_hash(struct sk_buff *skb); 1614 u32 __skb_get_hash_symmetric(const struct sk_buff *skb); 1615 u32 skb_get_poff(const struct sk_buff *skb); 1616 u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1617 const struct flow_keys_basic *keys, int hlen); 1618 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 1619 const void *data, int hlen_proto); 1620 1621 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, 1622 int thoff, u8 ip_proto) 1623 { 1624 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0); 1625 } 1626 1627 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 1628 const struct flow_dissector_key *key, 1629 unsigned int key_count); 1630 1631 struct bpf_flow_dissector; 1632 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 1633 __be16 proto, int nhoff, int hlen, unsigned int flags); 1634 1635 bool __skb_flow_dissect(const struct net *net, 1636 const struct sk_buff *skb, 1637 struct flow_dissector *flow_dissector, 1638 void *target_container, const void *data, 1639 __be16 proto, int nhoff, int hlen, unsigned int flags); 1640 1641 static inline bool skb_flow_dissect(const struct sk_buff *skb, 1642 struct flow_dissector *flow_dissector, 1643 void *target_container, unsigned int flags) 1644 { 1645 return __skb_flow_dissect(NULL, skb, flow_dissector, 1646 target_container, NULL, 0, 0, 0, flags); 1647 } 1648 1649 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb, 1650 struct flow_keys *flow, 1651 unsigned int flags) 1652 { 1653 memset(flow, 0, sizeof(*flow)); 1654 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector, 1655 flow, NULL, 0, 0, 0, flags); 1656 } 1657 1658 static inline bool 1659 skb_flow_dissect_flow_keys_basic(const struct net *net, 1660 const struct sk_buff *skb, 1661 struct flow_keys_basic *flow, 1662 const void *data, __be16 proto, 1663 int nhoff, int hlen, unsigned int flags) 1664 { 1665 memset(flow, 0, sizeof(*flow)); 1666 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow, 1667 data, proto, nhoff, hlen, flags); 1668 } 1669 1670 void skb_flow_dissect_meta(const struct sk_buff *skb, 1671 struct flow_dissector *flow_dissector, 1672 void *target_container); 1673 1674 /* Gets a skb connection tracking info, ctinfo map should be a 1675 * map of mapsize to translate enum ip_conntrack_info states 1676 * to user states. 1677 */ 1678 void 1679 skb_flow_dissect_ct(const struct sk_buff *skb, 1680 struct flow_dissector *flow_dissector, 1681 void *target_container, 1682 u16 *ctinfo_map, size_t mapsize, 1683 bool post_ct, u16 zone); 1684 void 1685 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 1686 struct flow_dissector *flow_dissector, 1687 void *target_container); 1688 1689 void skb_flow_dissect_hash(const struct sk_buff *skb, 1690 struct flow_dissector *flow_dissector, 1691 void *target_container); 1692 1693 static inline __u32 skb_get_hash(struct sk_buff *skb) 1694 { 1695 if (!skb->l4_hash && !skb->sw_hash) 1696 __skb_get_hash(skb); 1697 1698 return skb->hash; 1699 } 1700 1701 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 1702 { 1703 if (!skb->l4_hash && !skb->sw_hash) { 1704 struct flow_keys keys; 1705 __u32 hash = __get_hash_from_flowi6(fl6, &keys); 1706 1707 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1708 } 1709 1710 return skb->hash; 1711 } 1712 1713 __u32 skb_get_hash_perturb(const struct sk_buff *skb, 1714 const siphash_key_t *perturb); 1715 1716 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 1717 { 1718 return skb->hash; 1719 } 1720 1721 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 1722 { 1723 to->hash = from->hash; 1724 to->sw_hash = from->sw_hash; 1725 to->l4_hash = from->l4_hash; 1726 }; 1727 1728 static inline void skb_copy_decrypted(struct sk_buff *to, 1729 const struct sk_buff *from) 1730 { 1731 #ifdef CONFIG_TLS_DEVICE 1732 to->decrypted = from->decrypted; 1733 #endif 1734 } 1735 1736 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1737 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1738 { 1739 return skb->head + skb->end; 1740 } 1741 1742 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1743 { 1744 return skb->end; 1745 } 1746 1747 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1748 { 1749 skb->end = offset; 1750 } 1751 #else 1752 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1753 { 1754 return skb->end; 1755 } 1756 1757 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1758 { 1759 return skb->end - skb->head; 1760 } 1761 1762 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset) 1763 { 1764 skb->end = skb->head + offset; 1765 } 1766 #endif 1767 1768 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, 1769 struct ubuf_info *uarg); 1770 1771 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref); 1772 1773 void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg, 1774 bool success); 1775 1776 int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, 1777 struct iov_iter *from, size_t length); 1778 1779 static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb, 1780 struct msghdr *msg, int len) 1781 { 1782 return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len); 1783 } 1784 1785 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, 1786 struct msghdr *msg, int len, 1787 struct ubuf_info *uarg); 1788 1789 /* Internal */ 1790 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 1791 1792 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 1793 { 1794 return &skb_shinfo(skb)->hwtstamps; 1795 } 1796 1797 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb) 1798 { 1799 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE; 1800 1801 return is_zcopy ? skb_uarg(skb) : NULL; 1802 } 1803 1804 static inline bool skb_zcopy_pure(const struct sk_buff *skb) 1805 { 1806 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY; 1807 } 1808 1809 static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1, 1810 const struct sk_buff *skb2) 1811 { 1812 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2); 1813 } 1814 1815 static inline void net_zcopy_get(struct ubuf_info *uarg) 1816 { 1817 refcount_inc(&uarg->refcnt); 1818 } 1819 1820 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg) 1821 { 1822 skb_shinfo(skb)->destructor_arg = uarg; 1823 skb_shinfo(skb)->flags |= uarg->flags; 1824 } 1825 1826 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg, 1827 bool *have_ref) 1828 { 1829 if (skb && uarg && !skb_zcopy(skb)) { 1830 if (unlikely(have_ref && *have_ref)) 1831 *have_ref = false; 1832 else 1833 net_zcopy_get(uarg); 1834 skb_zcopy_init(skb, uarg); 1835 } 1836 } 1837 1838 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val) 1839 { 1840 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL); 1841 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG; 1842 } 1843 1844 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb) 1845 { 1846 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL; 1847 } 1848 1849 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb) 1850 { 1851 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL); 1852 } 1853 1854 static inline void net_zcopy_put(struct ubuf_info *uarg) 1855 { 1856 if (uarg) 1857 uarg->callback(NULL, uarg, true); 1858 } 1859 1860 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref) 1861 { 1862 if (uarg) { 1863 if (uarg->callback == msg_zerocopy_callback) 1864 msg_zerocopy_put_abort(uarg, have_uref); 1865 else if (have_uref) 1866 net_zcopy_put(uarg); 1867 } 1868 } 1869 1870 /* Release a reference on a zerocopy structure */ 1871 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success) 1872 { 1873 struct ubuf_info *uarg = skb_zcopy(skb); 1874 1875 if (uarg) { 1876 if (!skb_zcopy_is_nouarg(skb)) 1877 uarg->callback(skb, uarg, zerocopy_success); 1878 1879 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY; 1880 } 1881 } 1882 1883 static inline void skb_mark_not_on_list(struct sk_buff *skb) 1884 { 1885 skb->next = NULL; 1886 } 1887 1888 /* Iterate through singly-linked GSO fragments of an skb. */ 1889 #define skb_list_walk_safe(first, skb, next_skb) \ 1890 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \ 1891 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL) 1892 1893 static inline void skb_list_del_init(struct sk_buff *skb) 1894 { 1895 __list_del_entry(&skb->list); 1896 skb_mark_not_on_list(skb); 1897 } 1898 1899 /** 1900 * skb_queue_empty - check if a queue is empty 1901 * @list: queue head 1902 * 1903 * Returns true if the queue is empty, false otherwise. 1904 */ 1905 static inline int skb_queue_empty(const struct sk_buff_head *list) 1906 { 1907 return list->next == (const struct sk_buff *) list; 1908 } 1909 1910 /** 1911 * skb_queue_empty_lockless - check if a queue is empty 1912 * @list: queue head 1913 * 1914 * Returns true if the queue is empty, false otherwise. 1915 * This variant can be used in lockless contexts. 1916 */ 1917 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list) 1918 { 1919 return READ_ONCE(list->next) == (const struct sk_buff *) list; 1920 } 1921 1922 1923 /** 1924 * skb_queue_is_last - check if skb is the last entry in the queue 1925 * @list: queue head 1926 * @skb: buffer 1927 * 1928 * Returns true if @skb is the last buffer on the list. 1929 */ 1930 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 1931 const struct sk_buff *skb) 1932 { 1933 return skb->next == (const struct sk_buff *) list; 1934 } 1935 1936 /** 1937 * skb_queue_is_first - check if skb is the first entry in the queue 1938 * @list: queue head 1939 * @skb: buffer 1940 * 1941 * Returns true if @skb is the first buffer on the list. 1942 */ 1943 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 1944 const struct sk_buff *skb) 1945 { 1946 return skb->prev == (const struct sk_buff *) list; 1947 } 1948 1949 /** 1950 * skb_queue_next - return the next packet in the queue 1951 * @list: queue head 1952 * @skb: current buffer 1953 * 1954 * Return the next packet in @list after @skb. It is only valid to 1955 * call this if skb_queue_is_last() evaluates to false. 1956 */ 1957 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 1958 const struct sk_buff *skb) 1959 { 1960 /* This BUG_ON may seem severe, but if we just return then we 1961 * are going to dereference garbage. 1962 */ 1963 BUG_ON(skb_queue_is_last(list, skb)); 1964 return skb->next; 1965 } 1966 1967 /** 1968 * skb_queue_prev - return the prev packet in the queue 1969 * @list: queue head 1970 * @skb: current buffer 1971 * 1972 * Return the prev packet in @list before @skb. It is only valid to 1973 * call this if skb_queue_is_first() evaluates to false. 1974 */ 1975 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 1976 const struct sk_buff *skb) 1977 { 1978 /* This BUG_ON may seem severe, but if we just return then we 1979 * are going to dereference garbage. 1980 */ 1981 BUG_ON(skb_queue_is_first(list, skb)); 1982 return skb->prev; 1983 } 1984 1985 /** 1986 * skb_get - reference buffer 1987 * @skb: buffer to reference 1988 * 1989 * Makes another reference to a socket buffer and returns a pointer 1990 * to the buffer. 1991 */ 1992 static inline struct sk_buff *skb_get(struct sk_buff *skb) 1993 { 1994 refcount_inc(&skb->users); 1995 return skb; 1996 } 1997 1998 /* 1999 * If users == 1, we are the only owner and can avoid redundant atomic changes. 2000 */ 2001 2002 /** 2003 * skb_cloned - is the buffer a clone 2004 * @skb: buffer to check 2005 * 2006 * Returns true if the buffer was generated with skb_clone() and is 2007 * one of multiple shared copies of the buffer. Cloned buffers are 2008 * shared data so must not be written to under normal circumstances. 2009 */ 2010 static inline int skb_cloned(const struct sk_buff *skb) 2011 { 2012 return skb->cloned && 2013 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 2014 } 2015 2016 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 2017 { 2018 might_sleep_if(gfpflags_allow_blocking(pri)); 2019 2020 if (skb_cloned(skb)) 2021 return pskb_expand_head(skb, 0, 0, pri); 2022 2023 return 0; 2024 } 2025 2026 /* This variant of skb_unclone() makes sure skb->truesize 2027 * and skb_end_offset() are not changed, whenever a new skb->head is needed. 2028 * 2029 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X)) 2030 * when various debugging features are in place. 2031 */ 2032 int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri); 2033 static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri) 2034 { 2035 might_sleep_if(gfpflags_allow_blocking(pri)); 2036 2037 if (skb_cloned(skb)) 2038 return __skb_unclone_keeptruesize(skb, pri); 2039 return 0; 2040 } 2041 2042 /** 2043 * skb_header_cloned - is the header a clone 2044 * @skb: buffer to check 2045 * 2046 * Returns true if modifying the header part of the buffer requires 2047 * the data to be copied. 2048 */ 2049 static inline int skb_header_cloned(const struct sk_buff *skb) 2050 { 2051 int dataref; 2052 2053 if (!skb->cloned) 2054 return 0; 2055 2056 dataref = atomic_read(&skb_shinfo(skb)->dataref); 2057 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 2058 return dataref != 1; 2059 } 2060 2061 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri) 2062 { 2063 might_sleep_if(gfpflags_allow_blocking(pri)); 2064 2065 if (skb_header_cloned(skb)) 2066 return pskb_expand_head(skb, 0, 0, pri); 2067 2068 return 0; 2069 } 2070 2071 /** 2072 * __skb_header_release() - allow clones to use the headroom 2073 * @skb: buffer to operate on 2074 * 2075 * See "DOC: dataref and headerless skbs". 2076 */ 2077 static inline void __skb_header_release(struct sk_buff *skb) 2078 { 2079 skb->nohdr = 1; 2080 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT)); 2081 } 2082 2083 2084 /** 2085 * skb_shared - is the buffer shared 2086 * @skb: buffer to check 2087 * 2088 * Returns true if more than one person has a reference to this 2089 * buffer. 2090 */ 2091 static inline int skb_shared(const struct sk_buff *skb) 2092 { 2093 return refcount_read(&skb->users) != 1; 2094 } 2095 2096 /** 2097 * skb_share_check - check if buffer is shared and if so clone it 2098 * @skb: buffer to check 2099 * @pri: priority for memory allocation 2100 * 2101 * If the buffer is shared the buffer is cloned and the old copy 2102 * drops a reference. A new clone with a single reference is returned. 2103 * If the buffer is not shared the original buffer is returned. When 2104 * being called from interrupt status or with spinlocks held pri must 2105 * be GFP_ATOMIC. 2106 * 2107 * NULL is returned on a memory allocation failure. 2108 */ 2109 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 2110 { 2111 might_sleep_if(gfpflags_allow_blocking(pri)); 2112 if (skb_shared(skb)) { 2113 struct sk_buff *nskb = skb_clone(skb, pri); 2114 2115 if (likely(nskb)) 2116 consume_skb(skb); 2117 else 2118 kfree_skb(skb); 2119 skb = nskb; 2120 } 2121 return skb; 2122 } 2123 2124 /* 2125 * Copy shared buffers into a new sk_buff. We effectively do COW on 2126 * packets to handle cases where we have a local reader and forward 2127 * and a couple of other messy ones. The normal one is tcpdumping 2128 * a packet thats being forwarded. 2129 */ 2130 2131 /** 2132 * skb_unshare - make a copy of a shared buffer 2133 * @skb: buffer to check 2134 * @pri: priority for memory allocation 2135 * 2136 * If the socket buffer is a clone then this function creates a new 2137 * copy of the data, drops a reference count on the old copy and returns 2138 * the new copy with the reference count at 1. If the buffer is not a clone 2139 * the original buffer is returned. When called with a spinlock held or 2140 * from interrupt state @pri must be %GFP_ATOMIC 2141 * 2142 * %NULL is returned on a memory allocation failure. 2143 */ 2144 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 2145 gfp_t pri) 2146 { 2147 might_sleep_if(gfpflags_allow_blocking(pri)); 2148 if (skb_cloned(skb)) { 2149 struct sk_buff *nskb = skb_copy(skb, pri); 2150 2151 /* Free our shared copy */ 2152 if (likely(nskb)) 2153 consume_skb(skb); 2154 else 2155 kfree_skb(skb); 2156 skb = nskb; 2157 } 2158 return skb; 2159 } 2160 2161 /** 2162 * skb_peek - peek at the head of an &sk_buff_head 2163 * @list_: list to peek at 2164 * 2165 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2166 * be careful with this one. A peek leaves the buffer on the 2167 * list and someone else may run off with it. You must hold 2168 * the appropriate locks or have a private queue to do this. 2169 * 2170 * Returns %NULL for an empty list or a pointer to the head element. 2171 * The reference count is not incremented and the reference is therefore 2172 * volatile. Use with caution. 2173 */ 2174 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 2175 { 2176 struct sk_buff *skb = list_->next; 2177 2178 if (skb == (struct sk_buff *)list_) 2179 skb = NULL; 2180 return skb; 2181 } 2182 2183 /** 2184 * __skb_peek - peek at the head of a non-empty &sk_buff_head 2185 * @list_: list to peek at 2186 * 2187 * Like skb_peek(), but the caller knows that the list is not empty. 2188 */ 2189 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_) 2190 { 2191 return list_->next; 2192 } 2193 2194 /** 2195 * skb_peek_next - peek skb following the given one from a queue 2196 * @skb: skb to start from 2197 * @list_: list to peek at 2198 * 2199 * Returns %NULL when the end of the list is met or a pointer to the 2200 * next element. The reference count is not incremented and the 2201 * reference is therefore volatile. Use with caution. 2202 */ 2203 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 2204 const struct sk_buff_head *list_) 2205 { 2206 struct sk_buff *next = skb->next; 2207 2208 if (next == (struct sk_buff *)list_) 2209 next = NULL; 2210 return next; 2211 } 2212 2213 /** 2214 * skb_peek_tail - peek at the tail of an &sk_buff_head 2215 * @list_: list to peek at 2216 * 2217 * Peek an &sk_buff. Unlike most other operations you _MUST_ 2218 * be careful with this one. A peek leaves the buffer on the 2219 * list and someone else may run off with it. You must hold 2220 * the appropriate locks or have a private queue to do this. 2221 * 2222 * Returns %NULL for an empty list or a pointer to the tail element. 2223 * The reference count is not incremented and the reference is therefore 2224 * volatile. Use with caution. 2225 */ 2226 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 2227 { 2228 struct sk_buff *skb = READ_ONCE(list_->prev); 2229 2230 if (skb == (struct sk_buff *)list_) 2231 skb = NULL; 2232 return skb; 2233 2234 } 2235 2236 /** 2237 * skb_queue_len - get queue length 2238 * @list_: list to measure 2239 * 2240 * Return the length of an &sk_buff queue. 2241 */ 2242 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 2243 { 2244 return list_->qlen; 2245 } 2246 2247 /** 2248 * skb_queue_len_lockless - get queue length 2249 * @list_: list to measure 2250 * 2251 * Return the length of an &sk_buff queue. 2252 * This variant can be used in lockless contexts. 2253 */ 2254 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_) 2255 { 2256 return READ_ONCE(list_->qlen); 2257 } 2258 2259 /** 2260 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 2261 * @list: queue to initialize 2262 * 2263 * This initializes only the list and queue length aspects of 2264 * an sk_buff_head object. This allows to initialize the list 2265 * aspects of an sk_buff_head without reinitializing things like 2266 * the spinlock. It can also be used for on-stack sk_buff_head 2267 * objects where the spinlock is known to not be used. 2268 */ 2269 static inline void __skb_queue_head_init(struct sk_buff_head *list) 2270 { 2271 list->prev = list->next = (struct sk_buff *)list; 2272 list->qlen = 0; 2273 } 2274 2275 /* 2276 * This function creates a split out lock class for each invocation; 2277 * this is needed for now since a whole lot of users of the skb-queue 2278 * infrastructure in drivers have different locking usage (in hardirq) 2279 * than the networking core (in softirq only). In the long run either the 2280 * network layer or drivers should need annotation to consolidate the 2281 * main types of usage into 3 classes. 2282 */ 2283 static inline void skb_queue_head_init(struct sk_buff_head *list) 2284 { 2285 spin_lock_init(&list->lock); 2286 __skb_queue_head_init(list); 2287 } 2288 2289 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 2290 struct lock_class_key *class) 2291 { 2292 skb_queue_head_init(list); 2293 lockdep_set_class(&list->lock, class); 2294 } 2295 2296 /* 2297 * Insert an sk_buff on a list. 2298 * 2299 * The "__skb_xxxx()" functions are the non-atomic ones that 2300 * can only be called with interrupts disabled. 2301 */ 2302 static inline void __skb_insert(struct sk_buff *newsk, 2303 struct sk_buff *prev, struct sk_buff *next, 2304 struct sk_buff_head *list) 2305 { 2306 /* See skb_queue_empty_lockless() and skb_peek_tail() 2307 * for the opposite READ_ONCE() 2308 */ 2309 WRITE_ONCE(newsk->next, next); 2310 WRITE_ONCE(newsk->prev, prev); 2311 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk); 2312 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk); 2313 WRITE_ONCE(list->qlen, list->qlen + 1); 2314 } 2315 2316 static inline void __skb_queue_splice(const struct sk_buff_head *list, 2317 struct sk_buff *prev, 2318 struct sk_buff *next) 2319 { 2320 struct sk_buff *first = list->next; 2321 struct sk_buff *last = list->prev; 2322 2323 WRITE_ONCE(first->prev, prev); 2324 WRITE_ONCE(prev->next, first); 2325 2326 WRITE_ONCE(last->next, next); 2327 WRITE_ONCE(next->prev, last); 2328 } 2329 2330 /** 2331 * skb_queue_splice - join two skb lists, this is designed for stacks 2332 * @list: the new list to add 2333 * @head: the place to add it in the first list 2334 */ 2335 static inline void skb_queue_splice(const struct sk_buff_head *list, 2336 struct sk_buff_head *head) 2337 { 2338 if (!skb_queue_empty(list)) { 2339 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2340 head->qlen += list->qlen; 2341 } 2342 } 2343 2344 /** 2345 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 2346 * @list: the new list to add 2347 * @head: the place to add it in the first list 2348 * 2349 * The list at @list is reinitialised 2350 */ 2351 static inline void skb_queue_splice_init(struct sk_buff_head *list, 2352 struct sk_buff_head *head) 2353 { 2354 if (!skb_queue_empty(list)) { 2355 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 2356 head->qlen += list->qlen; 2357 __skb_queue_head_init(list); 2358 } 2359 } 2360 2361 /** 2362 * skb_queue_splice_tail - join two skb lists, each list being a queue 2363 * @list: the new list to add 2364 * @head: the place to add it in the first list 2365 */ 2366 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 2367 struct sk_buff_head *head) 2368 { 2369 if (!skb_queue_empty(list)) { 2370 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2371 head->qlen += list->qlen; 2372 } 2373 } 2374 2375 /** 2376 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 2377 * @list: the new list to add 2378 * @head: the place to add it in the first list 2379 * 2380 * Each of the lists is a queue. 2381 * The list at @list is reinitialised 2382 */ 2383 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 2384 struct sk_buff_head *head) 2385 { 2386 if (!skb_queue_empty(list)) { 2387 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 2388 head->qlen += list->qlen; 2389 __skb_queue_head_init(list); 2390 } 2391 } 2392 2393 /** 2394 * __skb_queue_after - queue a buffer at the list head 2395 * @list: list to use 2396 * @prev: place after this buffer 2397 * @newsk: buffer to queue 2398 * 2399 * Queue a buffer int the middle of a list. This function takes no locks 2400 * and you must therefore hold required locks before calling it. 2401 * 2402 * A buffer cannot be placed on two lists at the same time. 2403 */ 2404 static inline void __skb_queue_after(struct sk_buff_head *list, 2405 struct sk_buff *prev, 2406 struct sk_buff *newsk) 2407 { 2408 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list); 2409 } 2410 2411 void skb_append(struct sk_buff *old, struct sk_buff *newsk, 2412 struct sk_buff_head *list); 2413 2414 static inline void __skb_queue_before(struct sk_buff_head *list, 2415 struct sk_buff *next, 2416 struct sk_buff *newsk) 2417 { 2418 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list); 2419 } 2420 2421 /** 2422 * __skb_queue_head - queue a buffer at the list head 2423 * @list: list to use 2424 * @newsk: buffer to queue 2425 * 2426 * Queue a buffer at the start of a list. This function takes no locks 2427 * and you must therefore hold required locks before calling it. 2428 * 2429 * A buffer cannot be placed on two lists at the same time. 2430 */ 2431 static inline void __skb_queue_head(struct sk_buff_head *list, 2432 struct sk_buff *newsk) 2433 { 2434 __skb_queue_after(list, (struct sk_buff *)list, newsk); 2435 } 2436 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 2437 2438 /** 2439 * __skb_queue_tail - queue a buffer at the list tail 2440 * @list: list to use 2441 * @newsk: buffer to queue 2442 * 2443 * Queue a buffer at the end of a list. This function takes no locks 2444 * and you must therefore hold required locks before calling it. 2445 * 2446 * A buffer cannot be placed on two lists at the same time. 2447 */ 2448 static inline void __skb_queue_tail(struct sk_buff_head *list, 2449 struct sk_buff *newsk) 2450 { 2451 __skb_queue_before(list, (struct sk_buff *)list, newsk); 2452 } 2453 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 2454 2455 /* 2456 * remove sk_buff from list. _Must_ be called atomically, and with 2457 * the list known.. 2458 */ 2459 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 2460 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 2461 { 2462 struct sk_buff *next, *prev; 2463 2464 WRITE_ONCE(list->qlen, list->qlen - 1); 2465 next = skb->next; 2466 prev = skb->prev; 2467 skb->next = skb->prev = NULL; 2468 WRITE_ONCE(next->prev, prev); 2469 WRITE_ONCE(prev->next, next); 2470 } 2471 2472 /** 2473 * __skb_dequeue - remove from the head of the queue 2474 * @list: list to dequeue from 2475 * 2476 * Remove the head of the list. This function does not take any locks 2477 * so must be used with appropriate locks held only. The head item is 2478 * returned or %NULL if the list is empty. 2479 */ 2480 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 2481 { 2482 struct sk_buff *skb = skb_peek(list); 2483 if (skb) 2484 __skb_unlink(skb, list); 2485 return skb; 2486 } 2487 struct sk_buff *skb_dequeue(struct sk_buff_head *list); 2488 2489 /** 2490 * __skb_dequeue_tail - remove from the tail of the queue 2491 * @list: list to dequeue from 2492 * 2493 * Remove the tail of the list. This function does not take any locks 2494 * so must be used with appropriate locks held only. The tail item is 2495 * returned or %NULL if the list is empty. 2496 */ 2497 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 2498 { 2499 struct sk_buff *skb = skb_peek_tail(list); 2500 if (skb) 2501 __skb_unlink(skb, list); 2502 return skb; 2503 } 2504 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 2505 2506 2507 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 2508 { 2509 return skb->data_len; 2510 } 2511 2512 static inline unsigned int skb_headlen(const struct sk_buff *skb) 2513 { 2514 return skb->len - skb->data_len; 2515 } 2516 2517 static inline unsigned int __skb_pagelen(const struct sk_buff *skb) 2518 { 2519 unsigned int i, len = 0; 2520 2521 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--) 2522 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 2523 return len; 2524 } 2525 2526 static inline unsigned int skb_pagelen(const struct sk_buff *skb) 2527 { 2528 return skb_headlen(skb) + __skb_pagelen(skb); 2529 } 2530 2531 /** 2532 * __skb_fill_page_desc - initialise a paged fragment in an skb 2533 * @skb: buffer containing fragment to be initialised 2534 * @i: paged fragment index to initialise 2535 * @page: the page to use for this fragment 2536 * @off: the offset to the data with @page 2537 * @size: the length of the data 2538 * 2539 * Initialises the @i'th fragment of @skb to point to &size bytes at 2540 * offset @off within @page. 2541 * 2542 * Does not take any additional reference on the fragment. 2543 */ 2544 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 2545 struct page *page, int off, int size) 2546 { 2547 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 2548 2549 /* 2550 * Propagate page pfmemalloc to the skb if we can. The problem is 2551 * that not all callers have unique ownership of the page but rely 2552 * on page_is_pfmemalloc doing the right thing(tm). 2553 */ 2554 frag->bv_page = page; 2555 frag->bv_offset = off; 2556 skb_frag_size_set(frag, size); 2557 2558 page = compound_head(page); 2559 if (page_is_pfmemalloc(page)) 2560 skb->pfmemalloc = true; 2561 } 2562 2563 /** 2564 * skb_fill_page_desc - initialise a paged fragment in an skb 2565 * @skb: buffer containing fragment to be initialised 2566 * @i: paged fragment index to initialise 2567 * @page: the page to use for this fragment 2568 * @off: the offset to the data with @page 2569 * @size: the length of the data 2570 * 2571 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 2572 * @skb to point to @size bytes at offset @off within @page. In 2573 * addition updates @skb such that @i is the last fragment. 2574 * 2575 * Does not take any additional reference on the fragment. 2576 */ 2577 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 2578 struct page *page, int off, int size) 2579 { 2580 __skb_fill_page_desc(skb, i, page, off, size); 2581 skb_shinfo(skb)->nr_frags = i + 1; 2582 } 2583 2584 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, 2585 int size, unsigned int truesize); 2586 2587 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 2588 unsigned int truesize); 2589 2590 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 2591 2592 #ifdef NET_SKBUFF_DATA_USES_OFFSET 2593 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2594 { 2595 return skb->head + skb->tail; 2596 } 2597 2598 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2599 { 2600 skb->tail = skb->data - skb->head; 2601 } 2602 2603 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2604 { 2605 skb_reset_tail_pointer(skb); 2606 skb->tail += offset; 2607 } 2608 2609 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 2610 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 2611 { 2612 return skb->tail; 2613 } 2614 2615 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 2616 { 2617 skb->tail = skb->data; 2618 } 2619 2620 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 2621 { 2622 skb->tail = skb->data + offset; 2623 } 2624 2625 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 2626 2627 /* 2628 * Add data to an sk_buff 2629 */ 2630 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 2631 void *skb_put(struct sk_buff *skb, unsigned int len); 2632 static inline void *__skb_put(struct sk_buff *skb, unsigned int len) 2633 { 2634 void *tmp = skb_tail_pointer(skb); 2635 SKB_LINEAR_ASSERT(skb); 2636 skb->tail += len; 2637 skb->len += len; 2638 return tmp; 2639 } 2640 2641 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len) 2642 { 2643 void *tmp = __skb_put(skb, len); 2644 2645 memset(tmp, 0, len); 2646 return tmp; 2647 } 2648 2649 static inline void *__skb_put_data(struct sk_buff *skb, const void *data, 2650 unsigned int len) 2651 { 2652 void *tmp = __skb_put(skb, len); 2653 2654 memcpy(tmp, data, len); 2655 return tmp; 2656 } 2657 2658 static inline void __skb_put_u8(struct sk_buff *skb, u8 val) 2659 { 2660 *(u8 *)__skb_put(skb, 1) = val; 2661 } 2662 2663 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len) 2664 { 2665 void *tmp = skb_put(skb, len); 2666 2667 memset(tmp, 0, len); 2668 2669 return tmp; 2670 } 2671 2672 static inline void *skb_put_data(struct sk_buff *skb, const void *data, 2673 unsigned int len) 2674 { 2675 void *tmp = skb_put(skb, len); 2676 2677 memcpy(tmp, data, len); 2678 2679 return tmp; 2680 } 2681 2682 static inline void skb_put_u8(struct sk_buff *skb, u8 val) 2683 { 2684 *(u8 *)skb_put(skb, 1) = val; 2685 } 2686 2687 void *skb_push(struct sk_buff *skb, unsigned int len); 2688 static inline void *__skb_push(struct sk_buff *skb, unsigned int len) 2689 { 2690 skb->data -= len; 2691 skb->len += len; 2692 return skb->data; 2693 } 2694 2695 void *skb_pull(struct sk_buff *skb, unsigned int len); 2696 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len) 2697 { 2698 skb->len -= len; 2699 BUG_ON(skb->len < skb->data_len); 2700 return skb->data += len; 2701 } 2702 2703 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len) 2704 { 2705 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 2706 } 2707 2708 void *skb_pull_data(struct sk_buff *skb, size_t len); 2709 2710 void *__pskb_pull_tail(struct sk_buff *skb, int delta); 2711 2712 static inline void *__pskb_pull(struct sk_buff *skb, unsigned int len) 2713 { 2714 if (len > skb_headlen(skb) && 2715 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 2716 return NULL; 2717 skb->len -= len; 2718 return skb->data += len; 2719 } 2720 2721 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len) 2722 { 2723 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 2724 } 2725 2726 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len) 2727 { 2728 if (likely(len <= skb_headlen(skb))) 2729 return true; 2730 if (unlikely(len > skb->len)) 2731 return false; 2732 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 2733 } 2734 2735 void skb_condense(struct sk_buff *skb); 2736 2737 /** 2738 * skb_headroom - bytes at buffer head 2739 * @skb: buffer to check 2740 * 2741 * Return the number of bytes of free space at the head of an &sk_buff. 2742 */ 2743 static inline unsigned int skb_headroom(const struct sk_buff *skb) 2744 { 2745 return skb->data - skb->head; 2746 } 2747 2748 /** 2749 * skb_tailroom - bytes at buffer end 2750 * @skb: buffer to check 2751 * 2752 * Return the number of bytes of free space at the tail of an sk_buff 2753 */ 2754 static inline int skb_tailroom(const struct sk_buff *skb) 2755 { 2756 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 2757 } 2758 2759 /** 2760 * skb_availroom - bytes at buffer end 2761 * @skb: buffer to check 2762 * 2763 * Return the number of bytes of free space at the tail of an sk_buff 2764 * allocated by sk_stream_alloc() 2765 */ 2766 static inline int skb_availroom(const struct sk_buff *skb) 2767 { 2768 if (skb_is_nonlinear(skb)) 2769 return 0; 2770 2771 return skb->end - skb->tail - skb->reserved_tailroom; 2772 } 2773 2774 /** 2775 * skb_reserve - adjust headroom 2776 * @skb: buffer to alter 2777 * @len: bytes to move 2778 * 2779 * Increase the headroom of an empty &sk_buff by reducing the tail 2780 * room. This is only allowed for an empty buffer. 2781 */ 2782 static inline void skb_reserve(struct sk_buff *skb, int len) 2783 { 2784 skb->data += len; 2785 skb->tail += len; 2786 } 2787 2788 /** 2789 * skb_tailroom_reserve - adjust reserved_tailroom 2790 * @skb: buffer to alter 2791 * @mtu: maximum amount of headlen permitted 2792 * @needed_tailroom: minimum amount of reserved_tailroom 2793 * 2794 * Set reserved_tailroom so that headlen can be as large as possible but 2795 * not larger than mtu and tailroom cannot be smaller than 2796 * needed_tailroom. 2797 * The required headroom should already have been reserved before using 2798 * this function. 2799 */ 2800 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu, 2801 unsigned int needed_tailroom) 2802 { 2803 SKB_LINEAR_ASSERT(skb); 2804 if (mtu < skb_tailroom(skb) - needed_tailroom) 2805 /* use at most mtu */ 2806 skb->reserved_tailroom = skb_tailroom(skb) - mtu; 2807 else 2808 /* use up to all available space */ 2809 skb->reserved_tailroom = needed_tailroom; 2810 } 2811 2812 #define ENCAP_TYPE_ETHER 0 2813 #define ENCAP_TYPE_IPPROTO 1 2814 2815 static inline void skb_set_inner_protocol(struct sk_buff *skb, 2816 __be16 protocol) 2817 { 2818 skb->inner_protocol = protocol; 2819 skb->inner_protocol_type = ENCAP_TYPE_ETHER; 2820 } 2821 2822 static inline void skb_set_inner_ipproto(struct sk_buff *skb, 2823 __u8 ipproto) 2824 { 2825 skb->inner_ipproto = ipproto; 2826 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; 2827 } 2828 2829 static inline void skb_reset_inner_headers(struct sk_buff *skb) 2830 { 2831 skb->inner_mac_header = skb->mac_header; 2832 skb->inner_network_header = skb->network_header; 2833 skb->inner_transport_header = skb->transport_header; 2834 } 2835 2836 static inline void skb_reset_mac_len(struct sk_buff *skb) 2837 { 2838 skb->mac_len = skb->network_header - skb->mac_header; 2839 } 2840 2841 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 2842 *skb) 2843 { 2844 return skb->head + skb->inner_transport_header; 2845 } 2846 2847 static inline int skb_inner_transport_offset(const struct sk_buff *skb) 2848 { 2849 return skb_inner_transport_header(skb) - skb->data; 2850 } 2851 2852 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 2853 { 2854 skb->inner_transport_header = skb->data - skb->head; 2855 } 2856 2857 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 2858 const int offset) 2859 { 2860 skb_reset_inner_transport_header(skb); 2861 skb->inner_transport_header += offset; 2862 } 2863 2864 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 2865 { 2866 return skb->head + skb->inner_network_header; 2867 } 2868 2869 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 2870 { 2871 skb->inner_network_header = skb->data - skb->head; 2872 } 2873 2874 static inline void skb_set_inner_network_header(struct sk_buff *skb, 2875 const int offset) 2876 { 2877 skb_reset_inner_network_header(skb); 2878 skb->inner_network_header += offset; 2879 } 2880 2881 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 2882 { 2883 return skb->head + skb->inner_mac_header; 2884 } 2885 2886 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 2887 { 2888 skb->inner_mac_header = skb->data - skb->head; 2889 } 2890 2891 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 2892 const int offset) 2893 { 2894 skb_reset_inner_mac_header(skb); 2895 skb->inner_mac_header += offset; 2896 } 2897 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 2898 { 2899 return skb->transport_header != (typeof(skb->transport_header))~0U; 2900 } 2901 2902 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 2903 { 2904 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)); 2905 return skb->head + skb->transport_header; 2906 } 2907 2908 static inline void skb_reset_transport_header(struct sk_buff *skb) 2909 { 2910 skb->transport_header = skb->data - skb->head; 2911 } 2912 2913 static inline void skb_set_transport_header(struct sk_buff *skb, 2914 const int offset) 2915 { 2916 skb_reset_transport_header(skb); 2917 skb->transport_header += offset; 2918 } 2919 2920 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 2921 { 2922 return skb->head + skb->network_header; 2923 } 2924 2925 static inline void skb_reset_network_header(struct sk_buff *skb) 2926 { 2927 skb->network_header = skb->data - skb->head; 2928 } 2929 2930 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 2931 { 2932 skb_reset_network_header(skb); 2933 skb->network_header += offset; 2934 } 2935 2936 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 2937 { 2938 return skb->head + skb->mac_header; 2939 } 2940 2941 static inline int skb_mac_offset(const struct sk_buff *skb) 2942 { 2943 return skb_mac_header(skb) - skb->data; 2944 } 2945 2946 static inline u32 skb_mac_header_len(const struct sk_buff *skb) 2947 { 2948 return skb->network_header - skb->mac_header; 2949 } 2950 2951 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 2952 { 2953 return skb->mac_header != (typeof(skb->mac_header))~0U; 2954 } 2955 2956 static inline void skb_unset_mac_header(struct sk_buff *skb) 2957 { 2958 skb->mac_header = (typeof(skb->mac_header))~0U; 2959 } 2960 2961 static inline void skb_reset_mac_header(struct sk_buff *skb) 2962 { 2963 skb->mac_header = skb->data - skb->head; 2964 } 2965 2966 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 2967 { 2968 skb_reset_mac_header(skb); 2969 skb->mac_header += offset; 2970 } 2971 2972 static inline void skb_pop_mac_header(struct sk_buff *skb) 2973 { 2974 skb->mac_header = skb->network_header; 2975 } 2976 2977 static inline void skb_probe_transport_header(struct sk_buff *skb) 2978 { 2979 struct flow_keys_basic keys; 2980 2981 if (skb_transport_header_was_set(skb)) 2982 return; 2983 2984 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 2985 NULL, 0, 0, 0, 0)) 2986 skb_set_transport_header(skb, keys.control.thoff); 2987 } 2988 2989 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 2990 { 2991 if (skb_mac_header_was_set(skb)) { 2992 const unsigned char *old_mac = skb_mac_header(skb); 2993 2994 skb_set_mac_header(skb, -skb->mac_len); 2995 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 2996 } 2997 } 2998 2999 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 3000 { 3001 return skb->csum_start - skb_headroom(skb); 3002 } 3003 3004 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb) 3005 { 3006 return skb->head + skb->csum_start; 3007 } 3008 3009 static inline int skb_transport_offset(const struct sk_buff *skb) 3010 { 3011 return skb_transport_header(skb) - skb->data; 3012 } 3013 3014 static inline u32 skb_network_header_len(const struct sk_buff *skb) 3015 { 3016 return skb->transport_header - skb->network_header; 3017 } 3018 3019 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 3020 { 3021 return skb->inner_transport_header - skb->inner_network_header; 3022 } 3023 3024 static inline int skb_network_offset(const struct sk_buff *skb) 3025 { 3026 return skb_network_header(skb) - skb->data; 3027 } 3028 3029 static inline int skb_inner_network_offset(const struct sk_buff *skb) 3030 { 3031 return skb_inner_network_header(skb) - skb->data; 3032 } 3033 3034 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 3035 { 3036 return pskb_may_pull(skb, skb_network_offset(skb) + len); 3037 } 3038 3039 /* 3040 * CPUs often take a performance hit when accessing unaligned memory 3041 * locations. The actual performance hit varies, it can be small if the 3042 * hardware handles it or large if we have to take an exception and fix it 3043 * in software. 3044 * 3045 * Since an ethernet header is 14 bytes network drivers often end up with 3046 * the IP header at an unaligned offset. The IP header can be aligned by 3047 * shifting the start of the packet by 2 bytes. Drivers should do this 3048 * with: 3049 * 3050 * skb_reserve(skb, NET_IP_ALIGN); 3051 * 3052 * The downside to this alignment of the IP header is that the DMA is now 3053 * unaligned. On some architectures the cost of an unaligned DMA is high 3054 * and this cost outweighs the gains made by aligning the IP header. 3055 * 3056 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 3057 * to be overridden. 3058 */ 3059 #ifndef NET_IP_ALIGN 3060 #define NET_IP_ALIGN 2 3061 #endif 3062 3063 /* 3064 * The networking layer reserves some headroom in skb data (via 3065 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 3066 * the header has to grow. In the default case, if the header has to grow 3067 * 32 bytes or less we avoid the reallocation. 3068 * 3069 * Unfortunately this headroom changes the DMA alignment of the resulting 3070 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 3071 * on some architectures. An architecture can override this value, 3072 * perhaps setting it to a cacheline in size (since that will maintain 3073 * cacheline alignment of the DMA). It must be a power of 2. 3074 * 3075 * Various parts of the networking layer expect at least 32 bytes of 3076 * headroom, you should not reduce this. 3077 * 3078 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 3079 * to reduce average number of cache lines per packet. 3080 * get_rps_cpu() for example only access one 64 bytes aligned block : 3081 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 3082 */ 3083 #ifndef NET_SKB_PAD 3084 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 3085 #endif 3086 3087 int ___pskb_trim(struct sk_buff *skb, unsigned int len); 3088 3089 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len) 3090 { 3091 if (WARN_ON(skb_is_nonlinear(skb))) 3092 return; 3093 skb->len = len; 3094 skb_set_tail_pointer(skb, len); 3095 } 3096 3097 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 3098 { 3099 __skb_set_length(skb, len); 3100 } 3101 3102 void skb_trim(struct sk_buff *skb, unsigned int len); 3103 3104 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 3105 { 3106 if (skb->data_len) 3107 return ___pskb_trim(skb, len); 3108 __skb_trim(skb, len); 3109 return 0; 3110 } 3111 3112 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 3113 { 3114 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 3115 } 3116 3117 /** 3118 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 3119 * @skb: buffer to alter 3120 * @len: new length 3121 * 3122 * This is identical to pskb_trim except that the caller knows that 3123 * the skb is not cloned so we should never get an error due to out- 3124 * of-memory. 3125 */ 3126 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 3127 { 3128 int err = pskb_trim(skb, len); 3129 BUG_ON(err); 3130 } 3131 3132 static inline int __skb_grow(struct sk_buff *skb, unsigned int len) 3133 { 3134 unsigned int diff = len - skb->len; 3135 3136 if (skb_tailroom(skb) < diff) { 3137 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb), 3138 GFP_ATOMIC); 3139 if (ret) 3140 return ret; 3141 } 3142 __skb_set_length(skb, len); 3143 return 0; 3144 } 3145 3146 /** 3147 * skb_orphan - orphan a buffer 3148 * @skb: buffer to orphan 3149 * 3150 * If a buffer currently has an owner then we call the owner's 3151 * destructor function and make the @skb unowned. The buffer continues 3152 * to exist but is no longer charged to its former owner. 3153 */ 3154 static inline void skb_orphan(struct sk_buff *skb) 3155 { 3156 if (skb->destructor) { 3157 skb->destructor(skb); 3158 skb->destructor = NULL; 3159 skb->sk = NULL; 3160 } else { 3161 BUG_ON(skb->sk); 3162 } 3163 } 3164 3165 /** 3166 * skb_orphan_frags - orphan the frags contained in a buffer 3167 * @skb: buffer to orphan frags from 3168 * @gfp_mask: allocation mask for replacement pages 3169 * 3170 * For each frag in the SKB which needs a destructor (i.e. has an 3171 * owner) create a copy of that frag and release the original 3172 * page by calling the destructor. 3173 */ 3174 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 3175 { 3176 if (likely(!skb_zcopy(skb))) 3177 return 0; 3178 if (!skb_zcopy_is_nouarg(skb) && 3179 skb_uarg(skb)->callback == msg_zerocopy_callback) 3180 return 0; 3181 return skb_copy_ubufs(skb, gfp_mask); 3182 } 3183 3184 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */ 3185 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask) 3186 { 3187 if (likely(!skb_zcopy(skb))) 3188 return 0; 3189 return skb_copy_ubufs(skb, gfp_mask); 3190 } 3191 3192 /** 3193 * __skb_queue_purge - empty a list 3194 * @list: list to empty 3195 * 3196 * Delete all buffers on an &sk_buff list. Each buffer is removed from 3197 * the list and one reference dropped. This function does not take the 3198 * list lock and the caller must hold the relevant locks to use it. 3199 */ 3200 static inline void __skb_queue_purge(struct sk_buff_head *list) 3201 { 3202 struct sk_buff *skb; 3203 while ((skb = __skb_dequeue(list)) != NULL) 3204 kfree_skb(skb); 3205 } 3206 void skb_queue_purge(struct sk_buff_head *list); 3207 3208 unsigned int skb_rbtree_purge(struct rb_root *root); 3209 3210 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3211 3212 /** 3213 * netdev_alloc_frag - allocate a page fragment 3214 * @fragsz: fragment size 3215 * 3216 * Allocates a frag from a page for receive buffer. 3217 * Uses GFP_ATOMIC allocations. 3218 */ 3219 static inline void *netdev_alloc_frag(unsigned int fragsz) 3220 { 3221 return __netdev_alloc_frag_align(fragsz, ~0u); 3222 } 3223 3224 static inline void *netdev_alloc_frag_align(unsigned int fragsz, 3225 unsigned int align) 3226 { 3227 WARN_ON_ONCE(!is_power_of_2(align)); 3228 return __netdev_alloc_frag_align(fragsz, -align); 3229 } 3230 3231 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 3232 gfp_t gfp_mask); 3233 3234 /** 3235 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 3236 * @dev: network device to receive on 3237 * @length: length to allocate 3238 * 3239 * Allocate a new &sk_buff and assign it a usage count of one. The 3240 * buffer has unspecified headroom built in. Users should allocate 3241 * the headroom they think they need without accounting for the 3242 * built in space. The built in space is used for optimisations. 3243 * 3244 * %NULL is returned if there is no free memory. Although this function 3245 * allocates memory it can be called from an interrupt. 3246 */ 3247 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 3248 unsigned int length) 3249 { 3250 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 3251 } 3252 3253 /* legacy helper around __netdev_alloc_skb() */ 3254 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 3255 gfp_t gfp_mask) 3256 { 3257 return __netdev_alloc_skb(NULL, length, gfp_mask); 3258 } 3259 3260 /* legacy helper around netdev_alloc_skb() */ 3261 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 3262 { 3263 return netdev_alloc_skb(NULL, length); 3264 } 3265 3266 3267 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 3268 unsigned int length, gfp_t gfp) 3269 { 3270 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 3271 3272 if (NET_IP_ALIGN && skb) 3273 skb_reserve(skb, NET_IP_ALIGN); 3274 return skb; 3275 } 3276 3277 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 3278 unsigned int length) 3279 { 3280 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 3281 } 3282 3283 static inline void skb_free_frag(void *addr) 3284 { 3285 page_frag_free(addr); 3286 } 3287 3288 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask); 3289 3290 static inline void *napi_alloc_frag(unsigned int fragsz) 3291 { 3292 return __napi_alloc_frag_align(fragsz, ~0u); 3293 } 3294 3295 static inline void *napi_alloc_frag_align(unsigned int fragsz, 3296 unsigned int align) 3297 { 3298 WARN_ON_ONCE(!is_power_of_2(align)); 3299 return __napi_alloc_frag_align(fragsz, -align); 3300 } 3301 3302 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, 3303 unsigned int length, gfp_t gfp_mask); 3304 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, 3305 unsigned int length) 3306 { 3307 return __napi_alloc_skb(napi, length, GFP_ATOMIC); 3308 } 3309 void napi_consume_skb(struct sk_buff *skb, int budget); 3310 3311 void napi_skb_free_stolen_head(struct sk_buff *skb); 3312 void __kfree_skb_defer(struct sk_buff *skb); 3313 3314 /** 3315 * __dev_alloc_pages - allocate page for network Rx 3316 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3317 * @order: size of the allocation 3318 * 3319 * Allocate a new page. 3320 * 3321 * %NULL is returned if there is no free memory. 3322 */ 3323 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask, 3324 unsigned int order) 3325 { 3326 /* This piece of code contains several assumptions. 3327 * 1. This is for device Rx, therefor a cold page is preferred. 3328 * 2. The expectation is the user wants a compound page. 3329 * 3. If requesting a order 0 page it will not be compound 3330 * due to the check to see if order has a value in prep_new_page 3331 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to 3332 * code in gfp_to_alloc_flags that should be enforcing this. 3333 */ 3334 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC; 3335 3336 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 3337 } 3338 3339 static inline struct page *dev_alloc_pages(unsigned int order) 3340 { 3341 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order); 3342 } 3343 3344 /** 3345 * __dev_alloc_page - allocate a page for network Rx 3346 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 3347 * 3348 * Allocate a new page. 3349 * 3350 * %NULL is returned if there is no free memory. 3351 */ 3352 static inline struct page *__dev_alloc_page(gfp_t gfp_mask) 3353 { 3354 return __dev_alloc_pages(gfp_mask, 0); 3355 } 3356 3357 static inline struct page *dev_alloc_page(void) 3358 { 3359 return dev_alloc_pages(0); 3360 } 3361 3362 /** 3363 * dev_page_is_reusable - check whether a page can be reused for network Rx 3364 * @page: the page to test 3365 * 3366 * A page shouldn't be considered for reusing/recycling if it was allocated 3367 * under memory pressure or at a distant memory node. 3368 * 3369 * Returns false if this page should be returned to page allocator, true 3370 * otherwise. 3371 */ 3372 static inline bool dev_page_is_reusable(const struct page *page) 3373 { 3374 return likely(page_to_nid(page) == numa_mem_id() && 3375 !page_is_pfmemalloc(page)); 3376 } 3377 3378 /** 3379 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 3380 * @page: The page that was allocated from skb_alloc_page 3381 * @skb: The skb that may need pfmemalloc set 3382 */ 3383 static inline void skb_propagate_pfmemalloc(const struct page *page, 3384 struct sk_buff *skb) 3385 { 3386 if (page_is_pfmemalloc(page)) 3387 skb->pfmemalloc = true; 3388 } 3389 3390 /** 3391 * skb_frag_off() - Returns the offset of a skb fragment 3392 * @frag: the paged fragment 3393 */ 3394 static inline unsigned int skb_frag_off(const skb_frag_t *frag) 3395 { 3396 return frag->bv_offset; 3397 } 3398 3399 /** 3400 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta 3401 * @frag: skb fragment 3402 * @delta: value to add 3403 */ 3404 static inline void skb_frag_off_add(skb_frag_t *frag, int delta) 3405 { 3406 frag->bv_offset += delta; 3407 } 3408 3409 /** 3410 * skb_frag_off_set() - Sets the offset of a skb fragment 3411 * @frag: skb fragment 3412 * @offset: offset of fragment 3413 */ 3414 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset) 3415 { 3416 frag->bv_offset = offset; 3417 } 3418 3419 /** 3420 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment 3421 * @fragto: skb fragment where offset is set 3422 * @fragfrom: skb fragment offset is copied from 3423 */ 3424 static inline void skb_frag_off_copy(skb_frag_t *fragto, 3425 const skb_frag_t *fragfrom) 3426 { 3427 fragto->bv_offset = fragfrom->bv_offset; 3428 } 3429 3430 /** 3431 * skb_frag_page - retrieve the page referred to by a paged fragment 3432 * @frag: the paged fragment 3433 * 3434 * Returns the &struct page associated with @frag. 3435 */ 3436 static inline struct page *skb_frag_page(const skb_frag_t *frag) 3437 { 3438 return frag->bv_page; 3439 } 3440 3441 /** 3442 * __skb_frag_ref - take an addition reference on a paged fragment. 3443 * @frag: the paged fragment 3444 * 3445 * Takes an additional reference on the paged fragment @frag. 3446 */ 3447 static inline void __skb_frag_ref(skb_frag_t *frag) 3448 { 3449 get_page(skb_frag_page(frag)); 3450 } 3451 3452 /** 3453 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 3454 * @skb: the buffer 3455 * @f: the fragment offset. 3456 * 3457 * Takes an additional reference on the @f'th paged fragment of @skb. 3458 */ 3459 static inline void skb_frag_ref(struct sk_buff *skb, int f) 3460 { 3461 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 3462 } 3463 3464 /** 3465 * __skb_frag_unref - release a reference on a paged fragment. 3466 * @frag: the paged fragment 3467 * @recycle: recycle the page if allocated via page_pool 3468 * 3469 * Releases a reference on the paged fragment @frag 3470 * or recycles the page via the page_pool API. 3471 */ 3472 static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle) 3473 { 3474 struct page *page = skb_frag_page(frag); 3475 3476 #ifdef CONFIG_PAGE_POOL 3477 if (recycle && page_pool_return_skb_page(page)) 3478 return; 3479 #endif 3480 put_page(page); 3481 } 3482 3483 /** 3484 * skb_frag_unref - release a reference on a paged fragment of an skb. 3485 * @skb: the buffer 3486 * @f: the fragment offset 3487 * 3488 * Releases a reference on the @f'th paged fragment of @skb. 3489 */ 3490 static inline void skb_frag_unref(struct sk_buff *skb, int f) 3491 { 3492 __skb_frag_unref(&skb_shinfo(skb)->frags[f], skb->pp_recycle); 3493 } 3494 3495 /** 3496 * skb_frag_address - gets the address of the data contained in a paged fragment 3497 * @frag: the paged fragment buffer 3498 * 3499 * Returns the address of the data within @frag. The page must already 3500 * be mapped. 3501 */ 3502 static inline void *skb_frag_address(const skb_frag_t *frag) 3503 { 3504 return page_address(skb_frag_page(frag)) + skb_frag_off(frag); 3505 } 3506 3507 /** 3508 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 3509 * @frag: the paged fragment buffer 3510 * 3511 * Returns the address of the data within @frag. Checks that the page 3512 * is mapped and returns %NULL otherwise. 3513 */ 3514 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 3515 { 3516 void *ptr = page_address(skb_frag_page(frag)); 3517 if (unlikely(!ptr)) 3518 return NULL; 3519 3520 return ptr + skb_frag_off(frag); 3521 } 3522 3523 /** 3524 * skb_frag_page_copy() - sets the page in a fragment from another fragment 3525 * @fragto: skb fragment where page is set 3526 * @fragfrom: skb fragment page is copied from 3527 */ 3528 static inline void skb_frag_page_copy(skb_frag_t *fragto, 3529 const skb_frag_t *fragfrom) 3530 { 3531 fragto->bv_page = fragfrom->bv_page; 3532 } 3533 3534 /** 3535 * __skb_frag_set_page - sets the page contained in a paged fragment 3536 * @frag: the paged fragment 3537 * @page: the page to set 3538 * 3539 * Sets the fragment @frag to contain @page. 3540 */ 3541 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page) 3542 { 3543 frag->bv_page = page; 3544 } 3545 3546 /** 3547 * skb_frag_set_page - sets the page contained in a paged fragment of an skb 3548 * @skb: the buffer 3549 * @f: the fragment offset 3550 * @page: the page to set 3551 * 3552 * Sets the @f'th fragment of @skb to contain @page. 3553 */ 3554 static inline void skb_frag_set_page(struct sk_buff *skb, int f, 3555 struct page *page) 3556 { 3557 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page); 3558 } 3559 3560 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 3561 3562 /** 3563 * skb_frag_dma_map - maps a paged fragment via the DMA API 3564 * @dev: the device to map the fragment to 3565 * @frag: the paged fragment to map 3566 * @offset: the offset within the fragment (starting at the 3567 * fragment's own offset) 3568 * @size: the number of bytes to map 3569 * @dir: the direction of the mapping (``PCI_DMA_*``) 3570 * 3571 * Maps the page associated with @frag to @device. 3572 */ 3573 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 3574 const skb_frag_t *frag, 3575 size_t offset, size_t size, 3576 enum dma_data_direction dir) 3577 { 3578 return dma_map_page(dev, skb_frag_page(frag), 3579 skb_frag_off(frag) + offset, size, dir); 3580 } 3581 3582 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 3583 gfp_t gfp_mask) 3584 { 3585 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 3586 } 3587 3588 3589 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb, 3590 gfp_t gfp_mask) 3591 { 3592 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true); 3593 } 3594 3595 3596 /** 3597 * skb_clone_writable - is the header of a clone writable 3598 * @skb: buffer to check 3599 * @len: length up to which to write 3600 * 3601 * Returns true if modifying the header part of the cloned buffer 3602 * does not requires the data to be copied. 3603 */ 3604 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 3605 { 3606 return !skb_header_cloned(skb) && 3607 skb_headroom(skb) + len <= skb->hdr_len; 3608 } 3609 3610 static inline int skb_try_make_writable(struct sk_buff *skb, 3611 unsigned int write_len) 3612 { 3613 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) && 3614 pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 3615 } 3616 3617 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 3618 int cloned) 3619 { 3620 int delta = 0; 3621 3622 if (headroom > skb_headroom(skb)) 3623 delta = headroom - skb_headroom(skb); 3624 3625 if (delta || cloned) 3626 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 3627 GFP_ATOMIC); 3628 return 0; 3629 } 3630 3631 /** 3632 * skb_cow - copy header of skb when it is required 3633 * @skb: buffer to cow 3634 * @headroom: needed headroom 3635 * 3636 * If the skb passed lacks sufficient headroom or its data part 3637 * is shared, data is reallocated. If reallocation fails, an error 3638 * is returned and original skb is not changed. 3639 * 3640 * The result is skb with writable area skb->head...skb->tail 3641 * and at least @headroom of space at head. 3642 */ 3643 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 3644 { 3645 return __skb_cow(skb, headroom, skb_cloned(skb)); 3646 } 3647 3648 /** 3649 * skb_cow_head - skb_cow but only making the head writable 3650 * @skb: buffer to cow 3651 * @headroom: needed headroom 3652 * 3653 * This function is identical to skb_cow except that we replace the 3654 * skb_cloned check by skb_header_cloned. It should be used when 3655 * you only need to push on some header and do not need to modify 3656 * the data. 3657 */ 3658 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 3659 { 3660 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 3661 } 3662 3663 /** 3664 * skb_padto - pad an skbuff up to a minimal size 3665 * @skb: buffer to pad 3666 * @len: minimal length 3667 * 3668 * Pads up a buffer to ensure the trailing bytes exist and are 3669 * blanked. If the buffer already contains sufficient data it 3670 * is untouched. Otherwise it is extended. Returns zero on 3671 * success. The skb is freed on error. 3672 */ 3673 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 3674 { 3675 unsigned int size = skb->len; 3676 if (likely(size >= len)) 3677 return 0; 3678 return skb_pad(skb, len - size); 3679 } 3680 3681 /** 3682 * __skb_put_padto - increase size and pad an skbuff up to a minimal size 3683 * @skb: buffer to pad 3684 * @len: minimal length 3685 * @free_on_error: free buffer on error 3686 * 3687 * Pads up a buffer to ensure the trailing bytes exist and are 3688 * blanked. If the buffer already contains sufficient data it 3689 * is untouched. Otherwise it is extended. Returns zero on 3690 * success. The skb is freed on error if @free_on_error is true. 3691 */ 3692 static inline int __must_check __skb_put_padto(struct sk_buff *skb, 3693 unsigned int len, 3694 bool free_on_error) 3695 { 3696 unsigned int size = skb->len; 3697 3698 if (unlikely(size < len)) { 3699 len -= size; 3700 if (__skb_pad(skb, len, free_on_error)) 3701 return -ENOMEM; 3702 __skb_put(skb, len); 3703 } 3704 return 0; 3705 } 3706 3707 /** 3708 * skb_put_padto - increase size and pad an skbuff up to a minimal size 3709 * @skb: buffer to pad 3710 * @len: minimal length 3711 * 3712 * Pads up a buffer to ensure the trailing bytes exist and are 3713 * blanked. If the buffer already contains sufficient data it 3714 * is untouched. Otherwise it is extended. Returns zero on 3715 * success. The skb is freed on error. 3716 */ 3717 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len) 3718 { 3719 return __skb_put_padto(skb, len, true); 3720 } 3721 3722 static inline int skb_add_data(struct sk_buff *skb, 3723 struct iov_iter *from, int copy) 3724 { 3725 const int off = skb->len; 3726 3727 if (skb->ip_summed == CHECKSUM_NONE) { 3728 __wsum csum = 0; 3729 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy, 3730 &csum, from)) { 3731 skb->csum = csum_block_add(skb->csum, csum, off); 3732 return 0; 3733 } 3734 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from)) 3735 return 0; 3736 3737 __skb_trim(skb, off); 3738 return -EFAULT; 3739 } 3740 3741 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 3742 const struct page *page, int off) 3743 { 3744 if (skb_zcopy(skb)) 3745 return false; 3746 if (i) { 3747 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1]; 3748 3749 return page == skb_frag_page(frag) && 3750 off == skb_frag_off(frag) + skb_frag_size(frag); 3751 } 3752 return false; 3753 } 3754 3755 static inline int __skb_linearize(struct sk_buff *skb) 3756 { 3757 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 3758 } 3759 3760 /** 3761 * skb_linearize - convert paged skb to linear one 3762 * @skb: buffer to linarize 3763 * 3764 * If there is no free memory -ENOMEM is returned, otherwise zero 3765 * is returned and the old skb data released. 3766 */ 3767 static inline int skb_linearize(struct sk_buff *skb) 3768 { 3769 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 3770 } 3771 3772 /** 3773 * skb_has_shared_frag - can any frag be overwritten 3774 * @skb: buffer to test 3775 * 3776 * Return true if the skb has at least one frag that might be modified 3777 * by an external entity (as in vmsplice()/sendfile()) 3778 */ 3779 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 3780 { 3781 return skb_is_nonlinear(skb) && 3782 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG; 3783 } 3784 3785 /** 3786 * skb_linearize_cow - make sure skb is linear and writable 3787 * @skb: buffer to process 3788 * 3789 * If there is no free memory -ENOMEM is returned, otherwise zero 3790 * is returned and the old skb data released. 3791 */ 3792 static inline int skb_linearize_cow(struct sk_buff *skb) 3793 { 3794 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 3795 __skb_linearize(skb) : 0; 3796 } 3797 3798 static __always_inline void 3799 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3800 unsigned int off) 3801 { 3802 if (skb->ip_summed == CHECKSUM_COMPLETE) 3803 skb->csum = csum_block_sub(skb->csum, 3804 csum_partial(start, len, 0), off); 3805 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3806 skb_checksum_start_offset(skb) < 0) 3807 skb->ip_summed = CHECKSUM_NONE; 3808 } 3809 3810 /** 3811 * skb_postpull_rcsum - update checksum for received skb after pull 3812 * @skb: buffer to update 3813 * @start: start of data before pull 3814 * @len: length of data pulled 3815 * 3816 * After doing a pull on a received packet, you need to call this to 3817 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 3818 * CHECKSUM_NONE so that it can be recomputed from scratch. 3819 */ 3820 static inline void skb_postpull_rcsum(struct sk_buff *skb, 3821 const void *start, unsigned int len) 3822 { 3823 if (skb->ip_summed == CHECKSUM_COMPLETE) 3824 skb->csum = wsum_negate(csum_partial(start, len, 3825 wsum_negate(skb->csum))); 3826 else if (skb->ip_summed == CHECKSUM_PARTIAL && 3827 skb_checksum_start_offset(skb) < 0) 3828 skb->ip_summed = CHECKSUM_NONE; 3829 } 3830 3831 static __always_inline void 3832 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len, 3833 unsigned int off) 3834 { 3835 if (skb->ip_summed == CHECKSUM_COMPLETE) 3836 skb->csum = csum_block_add(skb->csum, 3837 csum_partial(start, len, 0), off); 3838 } 3839 3840 /** 3841 * skb_postpush_rcsum - update checksum for received skb after push 3842 * @skb: buffer to update 3843 * @start: start of data after push 3844 * @len: length of data pushed 3845 * 3846 * After doing a push on a received packet, you need to call this to 3847 * update the CHECKSUM_COMPLETE checksum. 3848 */ 3849 static inline void skb_postpush_rcsum(struct sk_buff *skb, 3850 const void *start, unsigned int len) 3851 { 3852 __skb_postpush_rcsum(skb, start, len, 0); 3853 } 3854 3855 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 3856 3857 /** 3858 * skb_push_rcsum - push skb and update receive checksum 3859 * @skb: buffer to update 3860 * @len: length of data pulled 3861 * 3862 * This function performs an skb_push on the packet and updates 3863 * the CHECKSUM_COMPLETE checksum. It should be used on 3864 * receive path processing instead of skb_push unless you know 3865 * that the checksum difference is zero (e.g., a valid IP header) 3866 * or you are setting ip_summed to CHECKSUM_NONE. 3867 */ 3868 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len) 3869 { 3870 skb_push(skb, len); 3871 skb_postpush_rcsum(skb, skb->data, len); 3872 return skb->data; 3873 } 3874 3875 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len); 3876 /** 3877 * pskb_trim_rcsum - trim received skb and update checksum 3878 * @skb: buffer to trim 3879 * @len: new length 3880 * 3881 * This is exactly the same as pskb_trim except that it ensures the 3882 * checksum of received packets are still valid after the operation. 3883 * It can change skb pointers. 3884 */ 3885 3886 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3887 { 3888 if (likely(len >= skb->len)) 3889 return 0; 3890 return pskb_trim_rcsum_slow(skb, len); 3891 } 3892 3893 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len) 3894 { 3895 if (skb->ip_summed == CHECKSUM_COMPLETE) 3896 skb->ip_summed = CHECKSUM_NONE; 3897 __skb_trim(skb, len); 3898 return 0; 3899 } 3900 3901 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len) 3902 { 3903 if (skb->ip_summed == CHECKSUM_COMPLETE) 3904 skb->ip_summed = CHECKSUM_NONE; 3905 return __skb_grow(skb, len); 3906 } 3907 3908 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode) 3909 #define skb_rb_first(root) rb_to_skb(rb_first(root)) 3910 #define skb_rb_last(root) rb_to_skb(rb_last(root)) 3911 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode)) 3912 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode)) 3913 3914 #define skb_queue_walk(queue, skb) \ 3915 for (skb = (queue)->next; \ 3916 skb != (struct sk_buff *)(queue); \ 3917 skb = skb->next) 3918 3919 #define skb_queue_walk_safe(queue, skb, tmp) \ 3920 for (skb = (queue)->next, tmp = skb->next; \ 3921 skb != (struct sk_buff *)(queue); \ 3922 skb = tmp, tmp = skb->next) 3923 3924 #define skb_queue_walk_from(queue, skb) \ 3925 for (; skb != (struct sk_buff *)(queue); \ 3926 skb = skb->next) 3927 3928 #define skb_rbtree_walk(skb, root) \ 3929 for (skb = skb_rb_first(root); skb != NULL; \ 3930 skb = skb_rb_next(skb)) 3931 3932 #define skb_rbtree_walk_from(skb) \ 3933 for (; skb != NULL; \ 3934 skb = skb_rb_next(skb)) 3935 3936 #define skb_rbtree_walk_from_safe(skb, tmp) \ 3937 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \ 3938 skb = tmp) 3939 3940 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 3941 for (tmp = skb->next; \ 3942 skb != (struct sk_buff *)(queue); \ 3943 skb = tmp, tmp = skb->next) 3944 3945 #define skb_queue_reverse_walk(queue, skb) \ 3946 for (skb = (queue)->prev; \ 3947 skb != (struct sk_buff *)(queue); \ 3948 skb = skb->prev) 3949 3950 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 3951 for (skb = (queue)->prev, tmp = skb->prev; \ 3952 skb != (struct sk_buff *)(queue); \ 3953 skb = tmp, tmp = skb->prev) 3954 3955 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 3956 for (tmp = skb->prev; \ 3957 skb != (struct sk_buff *)(queue); \ 3958 skb = tmp, tmp = skb->prev) 3959 3960 static inline bool skb_has_frag_list(const struct sk_buff *skb) 3961 { 3962 return skb_shinfo(skb)->frag_list != NULL; 3963 } 3964 3965 static inline void skb_frag_list_init(struct sk_buff *skb) 3966 { 3967 skb_shinfo(skb)->frag_list = NULL; 3968 } 3969 3970 #define skb_walk_frags(skb, iter) \ 3971 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 3972 3973 3974 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue, 3975 int *err, long *timeo_p, 3976 const struct sk_buff *skb); 3977 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 3978 struct sk_buff_head *queue, 3979 unsigned int flags, 3980 int *off, int *err, 3981 struct sk_buff **last); 3982 struct sk_buff *__skb_try_recv_datagram(struct sock *sk, 3983 struct sk_buff_head *queue, 3984 unsigned int flags, int *off, int *err, 3985 struct sk_buff **last); 3986 struct sk_buff *__skb_recv_datagram(struct sock *sk, 3987 struct sk_buff_head *sk_queue, 3988 unsigned int flags, int *off, int *err); 3989 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err); 3990 __poll_t datagram_poll(struct file *file, struct socket *sock, 3991 struct poll_table_struct *wait); 3992 int skb_copy_datagram_iter(const struct sk_buff *from, int offset, 3993 struct iov_iter *to, int size); 3994 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 3995 struct msghdr *msg, int size) 3996 { 3997 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size); 3998 } 3999 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 4000 struct msghdr *msg); 4001 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, 4002 struct iov_iter *to, int len, 4003 struct ahash_request *hash); 4004 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, 4005 struct iov_iter *from, int len); 4006 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 4007 void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 4008 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len); 4009 static inline void skb_free_datagram_locked(struct sock *sk, 4010 struct sk_buff *skb) 4011 { 4012 __skb_free_datagram_locked(sk, skb, 0); 4013 } 4014 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 4015 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 4016 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 4017 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 4018 int len); 4019 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, 4020 struct pipe_inode_info *pipe, unsigned int len, 4021 unsigned int flags); 4022 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, 4023 int len); 4024 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len); 4025 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 4026 unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 4027 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, 4028 int len, int hlen); 4029 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 4030 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 4031 void skb_scrub_packet(struct sk_buff *skb, bool xnet); 4032 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu); 4033 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); 4034 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 4035 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features, 4036 unsigned int offset); 4037 struct sk_buff *skb_vlan_untag(struct sk_buff *skb); 4038 int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len); 4039 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); 4040 int skb_vlan_pop(struct sk_buff *skb); 4041 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); 4042 int skb_eth_pop(struct sk_buff *skb); 4043 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst, 4044 const unsigned char *src); 4045 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, 4046 int mac_len, bool ethernet); 4047 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, 4048 bool ethernet); 4049 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse); 4050 int skb_mpls_dec_ttl(struct sk_buff *skb); 4051 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy, 4052 gfp_t gfp); 4053 4054 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len) 4055 { 4056 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT; 4057 } 4058 4059 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len) 4060 { 4061 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 4062 } 4063 4064 struct skb_checksum_ops { 4065 __wsum (*update)(const void *mem, int len, __wsum wsum); 4066 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 4067 }; 4068 4069 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly; 4070 4071 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 4072 __wsum csum, const struct skb_checksum_ops *ops); 4073 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 4074 __wsum csum); 4075 4076 static inline void * __must_check 4077 __skb_header_pointer(const struct sk_buff *skb, int offset, int len, 4078 const void *data, int hlen, void *buffer) 4079 { 4080 if (likely(hlen - offset >= len)) 4081 return (void *)data + offset; 4082 4083 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0)) 4084 return NULL; 4085 4086 return buffer; 4087 } 4088 4089 static inline void * __must_check 4090 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) 4091 { 4092 return __skb_header_pointer(skb, offset, len, skb->data, 4093 skb_headlen(skb), buffer); 4094 } 4095 4096 /** 4097 * skb_needs_linearize - check if we need to linearize a given skb 4098 * depending on the given device features. 4099 * @skb: socket buffer to check 4100 * @features: net device features 4101 * 4102 * Returns true if either: 4103 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 4104 * 2. skb is fragmented and the device does not support SG. 4105 */ 4106 static inline bool skb_needs_linearize(struct sk_buff *skb, 4107 netdev_features_t features) 4108 { 4109 return skb_is_nonlinear(skb) && 4110 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 4111 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 4112 } 4113 4114 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 4115 void *to, 4116 const unsigned int len) 4117 { 4118 memcpy(to, skb->data, len); 4119 } 4120 4121 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 4122 const int offset, void *to, 4123 const unsigned int len) 4124 { 4125 memcpy(to, skb->data + offset, len); 4126 } 4127 4128 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 4129 const void *from, 4130 const unsigned int len) 4131 { 4132 memcpy(skb->data, from, len); 4133 } 4134 4135 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 4136 const int offset, 4137 const void *from, 4138 const unsigned int len) 4139 { 4140 memcpy(skb->data + offset, from, len); 4141 } 4142 4143 void skb_init(void); 4144 4145 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 4146 { 4147 return skb->tstamp; 4148 } 4149 4150 /** 4151 * skb_get_timestamp - get timestamp from a skb 4152 * @skb: skb to get stamp from 4153 * @stamp: pointer to struct __kernel_old_timeval to store stamp in 4154 * 4155 * Timestamps are stored in the skb as offsets to a base timestamp. 4156 * This function converts the offset back to a struct timeval and stores 4157 * it in stamp. 4158 */ 4159 static inline void skb_get_timestamp(const struct sk_buff *skb, 4160 struct __kernel_old_timeval *stamp) 4161 { 4162 *stamp = ns_to_kernel_old_timeval(skb->tstamp); 4163 } 4164 4165 static inline void skb_get_new_timestamp(const struct sk_buff *skb, 4166 struct __kernel_sock_timeval *stamp) 4167 { 4168 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4169 4170 stamp->tv_sec = ts.tv_sec; 4171 stamp->tv_usec = ts.tv_nsec / 1000; 4172 } 4173 4174 static inline void skb_get_timestampns(const struct sk_buff *skb, 4175 struct __kernel_old_timespec *stamp) 4176 { 4177 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4178 4179 stamp->tv_sec = ts.tv_sec; 4180 stamp->tv_nsec = ts.tv_nsec; 4181 } 4182 4183 static inline void skb_get_new_timestampns(const struct sk_buff *skb, 4184 struct __kernel_timespec *stamp) 4185 { 4186 struct timespec64 ts = ktime_to_timespec64(skb->tstamp); 4187 4188 stamp->tv_sec = ts.tv_sec; 4189 stamp->tv_nsec = ts.tv_nsec; 4190 } 4191 4192 static inline void __net_timestamp(struct sk_buff *skb) 4193 { 4194 skb->tstamp = ktime_get_real(); 4195 skb->mono_delivery_time = 0; 4196 } 4197 4198 static inline ktime_t net_timedelta(ktime_t t) 4199 { 4200 return ktime_sub(ktime_get_real(), t); 4201 } 4202 4203 static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt, 4204 bool mono) 4205 { 4206 skb->tstamp = kt; 4207 skb->mono_delivery_time = kt && mono; 4208 } 4209 4210 DECLARE_STATIC_KEY_FALSE(netstamp_needed_key); 4211 4212 /* It is used in the ingress path to clear the delivery_time. 4213 * If needed, set the skb->tstamp to the (rcv) timestamp. 4214 */ 4215 static inline void skb_clear_delivery_time(struct sk_buff *skb) 4216 { 4217 if (skb->mono_delivery_time) { 4218 skb->mono_delivery_time = 0; 4219 if (static_branch_unlikely(&netstamp_needed_key)) 4220 skb->tstamp = ktime_get_real(); 4221 else 4222 skb->tstamp = 0; 4223 } 4224 } 4225 4226 static inline void skb_clear_tstamp(struct sk_buff *skb) 4227 { 4228 if (skb->mono_delivery_time) 4229 return; 4230 4231 skb->tstamp = 0; 4232 } 4233 4234 static inline ktime_t skb_tstamp(const struct sk_buff *skb) 4235 { 4236 if (skb->mono_delivery_time) 4237 return 0; 4238 4239 return skb->tstamp; 4240 } 4241 4242 static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond) 4243 { 4244 if (!skb->mono_delivery_time && skb->tstamp) 4245 return skb->tstamp; 4246 4247 if (static_branch_unlikely(&netstamp_needed_key) || cond) 4248 return ktime_get_real(); 4249 4250 return 0; 4251 } 4252 4253 static inline u8 skb_metadata_len(const struct sk_buff *skb) 4254 { 4255 return skb_shinfo(skb)->meta_len; 4256 } 4257 4258 static inline void *skb_metadata_end(const struct sk_buff *skb) 4259 { 4260 return skb_mac_header(skb); 4261 } 4262 4263 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a, 4264 const struct sk_buff *skb_b, 4265 u8 meta_len) 4266 { 4267 const void *a = skb_metadata_end(skb_a); 4268 const void *b = skb_metadata_end(skb_b); 4269 /* Using more efficient varaiant than plain call to memcmp(). */ 4270 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 4271 u64 diffs = 0; 4272 4273 switch (meta_len) { 4274 #define __it(x, op) (x -= sizeof(u##op)) 4275 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op)) 4276 case 32: diffs |= __it_diff(a, b, 64); 4277 fallthrough; 4278 case 24: diffs |= __it_diff(a, b, 64); 4279 fallthrough; 4280 case 16: diffs |= __it_diff(a, b, 64); 4281 fallthrough; 4282 case 8: diffs |= __it_diff(a, b, 64); 4283 break; 4284 case 28: diffs |= __it_diff(a, b, 64); 4285 fallthrough; 4286 case 20: diffs |= __it_diff(a, b, 64); 4287 fallthrough; 4288 case 12: diffs |= __it_diff(a, b, 64); 4289 fallthrough; 4290 case 4: diffs |= __it_diff(a, b, 32); 4291 break; 4292 } 4293 return diffs; 4294 #else 4295 return memcmp(a - meta_len, b - meta_len, meta_len); 4296 #endif 4297 } 4298 4299 static inline bool skb_metadata_differs(const struct sk_buff *skb_a, 4300 const struct sk_buff *skb_b) 4301 { 4302 u8 len_a = skb_metadata_len(skb_a); 4303 u8 len_b = skb_metadata_len(skb_b); 4304 4305 if (!(len_a | len_b)) 4306 return false; 4307 4308 return len_a != len_b ? 4309 true : __skb_metadata_differs(skb_a, skb_b, len_a); 4310 } 4311 4312 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len) 4313 { 4314 skb_shinfo(skb)->meta_len = meta_len; 4315 } 4316 4317 static inline void skb_metadata_clear(struct sk_buff *skb) 4318 { 4319 skb_metadata_set(skb, 0); 4320 } 4321 4322 struct sk_buff *skb_clone_sk(struct sk_buff *skb); 4323 4324 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 4325 4326 void skb_clone_tx_timestamp(struct sk_buff *skb); 4327 bool skb_defer_rx_timestamp(struct sk_buff *skb); 4328 4329 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 4330 4331 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 4332 { 4333 } 4334 4335 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 4336 { 4337 return false; 4338 } 4339 4340 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 4341 4342 /** 4343 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 4344 * 4345 * PHY drivers may accept clones of transmitted packets for 4346 * timestamping via their phy_driver.txtstamp method. These drivers 4347 * must call this function to return the skb back to the stack with a 4348 * timestamp. 4349 * 4350 * @skb: clone of the original outgoing packet 4351 * @hwtstamps: hardware time stamps 4352 * 4353 */ 4354 void skb_complete_tx_timestamp(struct sk_buff *skb, 4355 struct skb_shared_hwtstamps *hwtstamps); 4356 4357 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb, 4358 struct skb_shared_hwtstamps *hwtstamps, 4359 struct sock *sk, int tstype); 4360 4361 /** 4362 * skb_tstamp_tx - queue clone of skb with send time stamps 4363 * @orig_skb: the original outgoing packet 4364 * @hwtstamps: hardware time stamps, may be NULL if not available 4365 * 4366 * If the skb has a socket associated, then this function clones the 4367 * skb (thus sharing the actual data and optional structures), stores 4368 * the optional hardware time stamping information (if non NULL) or 4369 * generates a software time stamp (otherwise), then queues the clone 4370 * to the error queue of the socket. Errors are silently ignored. 4371 */ 4372 void skb_tstamp_tx(struct sk_buff *orig_skb, 4373 struct skb_shared_hwtstamps *hwtstamps); 4374 4375 /** 4376 * skb_tx_timestamp() - Driver hook for transmit timestamping 4377 * 4378 * Ethernet MAC Drivers should call this function in their hard_xmit() 4379 * function immediately before giving the sk_buff to the MAC hardware. 4380 * 4381 * Specifically, one should make absolutely sure that this function is 4382 * called before TX completion of this packet can trigger. Otherwise 4383 * the packet could potentially already be freed. 4384 * 4385 * @skb: A socket buffer. 4386 */ 4387 static inline void skb_tx_timestamp(struct sk_buff *skb) 4388 { 4389 skb_clone_tx_timestamp(skb); 4390 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP) 4391 skb_tstamp_tx(skb, NULL); 4392 } 4393 4394 /** 4395 * skb_complete_wifi_ack - deliver skb with wifi status 4396 * 4397 * @skb: the original outgoing packet 4398 * @acked: ack status 4399 * 4400 */ 4401 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 4402 4403 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 4404 __sum16 __skb_checksum_complete(struct sk_buff *skb); 4405 4406 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 4407 { 4408 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) || 4409 skb->csum_valid || 4410 (skb->ip_summed == CHECKSUM_PARTIAL && 4411 skb_checksum_start_offset(skb) >= 0)); 4412 } 4413 4414 /** 4415 * skb_checksum_complete - Calculate checksum of an entire packet 4416 * @skb: packet to process 4417 * 4418 * This function calculates the checksum over the entire packet plus 4419 * the value of skb->csum. The latter can be used to supply the 4420 * checksum of a pseudo header as used by TCP/UDP. It returns the 4421 * checksum. 4422 * 4423 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 4424 * this function can be used to verify that checksum on received 4425 * packets. In that case the function should return zero if the 4426 * checksum is correct. In particular, this function will return zero 4427 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 4428 * hardware has already verified the correctness of the checksum. 4429 */ 4430 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 4431 { 4432 return skb_csum_unnecessary(skb) ? 4433 0 : __skb_checksum_complete(skb); 4434 } 4435 4436 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb) 4437 { 4438 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4439 if (skb->csum_level == 0) 4440 skb->ip_summed = CHECKSUM_NONE; 4441 else 4442 skb->csum_level--; 4443 } 4444 } 4445 4446 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) 4447 { 4448 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4449 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 4450 skb->csum_level++; 4451 } else if (skb->ip_summed == CHECKSUM_NONE) { 4452 skb->ip_summed = CHECKSUM_UNNECESSARY; 4453 skb->csum_level = 0; 4454 } 4455 } 4456 4457 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb) 4458 { 4459 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 4460 skb->ip_summed = CHECKSUM_NONE; 4461 skb->csum_level = 0; 4462 } 4463 } 4464 4465 /* Check if we need to perform checksum complete validation. 4466 * 4467 * Returns true if checksum complete is needed, false otherwise 4468 * (either checksum is unnecessary or zero checksum is allowed). 4469 */ 4470 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, 4471 bool zero_okay, 4472 __sum16 check) 4473 { 4474 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) { 4475 skb->csum_valid = 1; 4476 __skb_decr_checksum_unnecessary(skb); 4477 return false; 4478 } 4479 4480 return true; 4481 } 4482 4483 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly 4484 * in checksum_init. 4485 */ 4486 #define CHECKSUM_BREAK 76 4487 4488 /* Unset checksum-complete 4489 * 4490 * Unset checksum complete can be done when packet is being modified 4491 * (uncompressed for instance) and checksum-complete value is 4492 * invalidated. 4493 */ 4494 static inline void skb_checksum_complete_unset(struct sk_buff *skb) 4495 { 4496 if (skb->ip_summed == CHECKSUM_COMPLETE) 4497 skb->ip_summed = CHECKSUM_NONE; 4498 } 4499 4500 /* Validate (init) checksum based on checksum complete. 4501 * 4502 * Return values: 4503 * 0: checksum is validated or try to in skb_checksum_complete. In the latter 4504 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo 4505 * checksum is stored in skb->csum for use in __skb_checksum_complete 4506 * non-zero: value of invalid checksum 4507 * 4508 */ 4509 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, 4510 bool complete, 4511 __wsum psum) 4512 { 4513 if (skb->ip_summed == CHECKSUM_COMPLETE) { 4514 if (!csum_fold(csum_add(psum, skb->csum))) { 4515 skb->csum_valid = 1; 4516 return 0; 4517 } 4518 } 4519 4520 skb->csum = psum; 4521 4522 if (complete || skb->len <= CHECKSUM_BREAK) { 4523 __sum16 csum; 4524 4525 csum = __skb_checksum_complete(skb); 4526 skb->csum_valid = !csum; 4527 return csum; 4528 } 4529 4530 return 0; 4531 } 4532 4533 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) 4534 { 4535 return 0; 4536 } 4537 4538 /* Perform checksum validate (init). Note that this is a macro since we only 4539 * want to calculate the pseudo header which is an input function if necessary. 4540 * First we try to validate without any computation (checksum unnecessary) and 4541 * then calculate based on checksum complete calling the function to compute 4542 * pseudo header. 4543 * 4544 * Return values: 4545 * 0: checksum is validated or try to in skb_checksum_complete 4546 * non-zero: value of invalid checksum 4547 */ 4548 #define __skb_checksum_validate(skb, proto, complete, \ 4549 zero_okay, check, compute_pseudo) \ 4550 ({ \ 4551 __sum16 __ret = 0; \ 4552 skb->csum_valid = 0; \ 4553 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ 4554 __ret = __skb_checksum_validate_complete(skb, \ 4555 complete, compute_pseudo(skb, proto)); \ 4556 __ret; \ 4557 }) 4558 4559 #define skb_checksum_init(skb, proto, compute_pseudo) \ 4560 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) 4561 4562 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ 4563 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) 4564 4565 #define skb_checksum_validate(skb, proto, compute_pseudo) \ 4566 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) 4567 4568 #define skb_checksum_validate_zero_check(skb, proto, check, \ 4569 compute_pseudo) \ 4570 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo) 4571 4572 #define skb_checksum_simple_validate(skb) \ 4573 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) 4574 4575 static inline bool __skb_checksum_convert_check(struct sk_buff *skb) 4576 { 4577 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid); 4578 } 4579 4580 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo) 4581 { 4582 skb->csum = ~pseudo; 4583 skb->ip_summed = CHECKSUM_COMPLETE; 4584 } 4585 4586 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \ 4587 do { \ 4588 if (__skb_checksum_convert_check(skb)) \ 4589 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \ 4590 } while (0) 4591 4592 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr, 4593 u16 start, u16 offset) 4594 { 4595 skb->ip_summed = CHECKSUM_PARTIAL; 4596 skb->csum_start = ((unsigned char *)ptr + start) - skb->head; 4597 skb->csum_offset = offset - start; 4598 } 4599 4600 /* Update skbuf and packet to reflect the remote checksum offload operation. 4601 * When called, ptr indicates the starting point for skb->csum when 4602 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete 4603 * here, skb_postpull_rcsum is done so skb->csum start is ptr. 4604 */ 4605 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr, 4606 int start, int offset, bool nopartial) 4607 { 4608 __wsum delta; 4609 4610 if (!nopartial) { 4611 skb_remcsum_adjust_partial(skb, ptr, start, offset); 4612 return; 4613 } 4614 4615 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) { 4616 __skb_checksum_complete(skb); 4617 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data); 4618 } 4619 4620 delta = remcsum_adjust(ptr, skb->csum, start, offset); 4621 4622 /* Adjust skb->csum since we changed the packet */ 4623 skb->csum = csum_add(skb->csum, delta); 4624 } 4625 4626 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb) 4627 { 4628 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4629 return (void *)(skb->_nfct & NFCT_PTRMASK); 4630 #else 4631 return NULL; 4632 #endif 4633 } 4634 4635 static inline unsigned long skb_get_nfct(const struct sk_buff *skb) 4636 { 4637 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4638 return skb->_nfct; 4639 #else 4640 return 0UL; 4641 #endif 4642 } 4643 4644 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct) 4645 { 4646 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 4647 skb->slow_gro |= !!nfct; 4648 skb->_nfct = nfct; 4649 #endif 4650 } 4651 4652 #ifdef CONFIG_SKB_EXTENSIONS 4653 enum skb_ext_id { 4654 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 4655 SKB_EXT_BRIDGE_NF, 4656 #endif 4657 #ifdef CONFIG_XFRM 4658 SKB_EXT_SEC_PATH, 4659 #endif 4660 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 4661 TC_SKB_EXT, 4662 #endif 4663 #if IS_ENABLED(CONFIG_MPTCP) 4664 SKB_EXT_MPTCP, 4665 #endif 4666 #if IS_ENABLED(CONFIG_MCTP_FLOWS) 4667 SKB_EXT_MCTP, 4668 #endif 4669 SKB_EXT_NUM, /* must be last */ 4670 }; 4671 4672 /** 4673 * struct skb_ext - sk_buff extensions 4674 * @refcnt: 1 on allocation, deallocated on 0 4675 * @offset: offset to add to @data to obtain extension address 4676 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units 4677 * @data: start of extension data, variable sized 4678 * 4679 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows 4680 * to use 'u8' types while allowing up to 2kb worth of extension data. 4681 */ 4682 struct skb_ext { 4683 refcount_t refcnt; 4684 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */ 4685 u8 chunks; /* same */ 4686 char data[] __aligned(8); 4687 }; 4688 4689 struct skb_ext *__skb_ext_alloc(gfp_t flags); 4690 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, 4691 struct skb_ext *ext); 4692 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); 4693 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); 4694 void __skb_ext_put(struct skb_ext *ext); 4695 4696 static inline void skb_ext_put(struct sk_buff *skb) 4697 { 4698 if (skb->active_extensions) 4699 __skb_ext_put(skb->extensions); 4700 } 4701 4702 static inline void __skb_ext_copy(struct sk_buff *dst, 4703 const struct sk_buff *src) 4704 { 4705 dst->active_extensions = src->active_extensions; 4706 4707 if (src->active_extensions) { 4708 struct skb_ext *ext = src->extensions; 4709 4710 refcount_inc(&ext->refcnt); 4711 dst->extensions = ext; 4712 } 4713 } 4714 4715 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src) 4716 { 4717 skb_ext_put(dst); 4718 __skb_ext_copy(dst, src); 4719 } 4720 4721 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i) 4722 { 4723 return !!ext->offset[i]; 4724 } 4725 4726 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id) 4727 { 4728 return skb->active_extensions & (1 << id); 4729 } 4730 4731 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) 4732 { 4733 if (skb_ext_exist(skb, id)) 4734 __skb_ext_del(skb, id); 4735 } 4736 4737 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id) 4738 { 4739 if (skb_ext_exist(skb, id)) { 4740 struct skb_ext *ext = skb->extensions; 4741 4742 return (void *)ext + (ext->offset[id] << 3); 4743 } 4744 4745 return NULL; 4746 } 4747 4748 static inline void skb_ext_reset(struct sk_buff *skb) 4749 { 4750 if (unlikely(skb->active_extensions)) { 4751 __skb_ext_put(skb->extensions); 4752 skb->active_extensions = 0; 4753 } 4754 } 4755 4756 static inline bool skb_has_extensions(struct sk_buff *skb) 4757 { 4758 return unlikely(skb->active_extensions); 4759 } 4760 #else 4761 static inline void skb_ext_put(struct sk_buff *skb) {} 4762 static inline void skb_ext_reset(struct sk_buff *skb) {} 4763 static inline void skb_ext_del(struct sk_buff *skb, int unused) {} 4764 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {} 4765 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {} 4766 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; } 4767 #endif /* CONFIG_SKB_EXTENSIONS */ 4768 4769 static inline void nf_reset_ct(struct sk_buff *skb) 4770 { 4771 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4772 nf_conntrack_put(skb_nfct(skb)); 4773 skb->_nfct = 0; 4774 #endif 4775 } 4776 4777 static inline void nf_reset_trace(struct sk_buff *skb) 4778 { 4779 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 4780 skb->nf_trace = 0; 4781 #endif 4782 } 4783 4784 static inline void ipvs_reset(struct sk_buff *skb) 4785 { 4786 #if IS_ENABLED(CONFIG_IP_VS) 4787 skb->ipvs_property = 0; 4788 #endif 4789 } 4790 4791 /* Note: This doesn't put any conntrack info in dst. */ 4792 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src, 4793 bool copy) 4794 { 4795 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4796 dst->_nfct = src->_nfct; 4797 nf_conntrack_get(skb_nfct(src)); 4798 #endif 4799 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 4800 if (copy) 4801 dst->nf_trace = src->nf_trace; 4802 #endif 4803 } 4804 4805 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 4806 { 4807 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 4808 nf_conntrack_put(skb_nfct(dst)); 4809 #endif 4810 dst->slow_gro = src->slow_gro; 4811 __nf_copy(dst, src, true); 4812 } 4813 4814 #ifdef CONFIG_NETWORK_SECMARK 4815 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4816 { 4817 to->secmark = from->secmark; 4818 } 4819 4820 static inline void skb_init_secmark(struct sk_buff *skb) 4821 { 4822 skb->secmark = 0; 4823 } 4824 #else 4825 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 4826 { } 4827 4828 static inline void skb_init_secmark(struct sk_buff *skb) 4829 { } 4830 #endif 4831 4832 static inline int secpath_exists(const struct sk_buff *skb) 4833 { 4834 #ifdef CONFIG_XFRM 4835 return skb_ext_exist(skb, SKB_EXT_SEC_PATH); 4836 #else 4837 return 0; 4838 #endif 4839 } 4840 4841 static inline bool skb_irq_freeable(const struct sk_buff *skb) 4842 { 4843 return !skb->destructor && 4844 !secpath_exists(skb) && 4845 !skb_nfct(skb) && 4846 !skb->_skb_refdst && 4847 !skb_has_frag_list(skb); 4848 } 4849 4850 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 4851 { 4852 skb->queue_mapping = queue_mapping; 4853 } 4854 4855 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 4856 { 4857 return skb->queue_mapping; 4858 } 4859 4860 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 4861 { 4862 to->queue_mapping = from->queue_mapping; 4863 } 4864 4865 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 4866 { 4867 skb->queue_mapping = rx_queue + 1; 4868 } 4869 4870 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 4871 { 4872 return skb->queue_mapping - 1; 4873 } 4874 4875 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 4876 { 4877 return skb->queue_mapping != 0; 4878 } 4879 4880 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val) 4881 { 4882 skb->dst_pending_confirm = val; 4883 } 4884 4885 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb) 4886 { 4887 return skb->dst_pending_confirm != 0; 4888 } 4889 4890 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb) 4891 { 4892 #ifdef CONFIG_XFRM 4893 return skb_ext_find(skb, SKB_EXT_SEC_PATH); 4894 #else 4895 return NULL; 4896 #endif 4897 } 4898 4899 /* Keeps track of mac header offset relative to skb->head. 4900 * It is useful for TSO of Tunneling protocol. e.g. GRE. 4901 * For non-tunnel skb it points to skb_mac_header() and for 4902 * tunnel skb it points to outer mac header. 4903 * Keeps track of level of encapsulation of network headers. 4904 */ 4905 struct skb_gso_cb { 4906 union { 4907 int mac_offset; 4908 int data_offset; 4909 }; 4910 int encap_level; 4911 __wsum csum; 4912 __u16 csum_start; 4913 }; 4914 #define SKB_GSO_CB_OFFSET 32 4915 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET)) 4916 4917 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) 4918 { 4919 return (skb_mac_header(inner_skb) - inner_skb->head) - 4920 SKB_GSO_CB(inner_skb)->mac_offset; 4921 } 4922 4923 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) 4924 { 4925 int new_headroom, headroom; 4926 int ret; 4927 4928 headroom = skb_headroom(skb); 4929 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); 4930 if (ret) 4931 return ret; 4932 4933 new_headroom = skb_headroom(skb); 4934 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); 4935 return 0; 4936 } 4937 4938 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res) 4939 { 4940 /* Do not update partial checksums if remote checksum is enabled. */ 4941 if (skb->remcsum_offload) 4942 return; 4943 4944 SKB_GSO_CB(skb)->csum = res; 4945 SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head; 4946 } 4947 4948 /* Compute the checksum for a gso segment. First compute the checksum value 4949 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and 4950 * then add in skb->csum (checksum from csum_start to end of packet). 4951 * skb->csum and csum_start are then updated to reflect the checksum of the 4952 * resultant packet starting from the transport header-- the resultant checksum 4953 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo 4954 * header. 4955 */ 4956 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) 4957 { 4958 unsigned char *csum_start = skb_transport_header(skb); 4959 int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start; 4960 __wsum partial = SKB_GSO_CB(skb)->csum; 4961 4962 SKB_GSO_CB(skb)->csum = res; 4963 SKB_GSO_CB(skb)->csum_start = csum_start - skb->head; 4964 4965 return csum_fold(csum_partial(csum_start, plen, partial)); 4966 } 4967 4968 static inline bool skb_is_gso(const struct sk_buff *skb) 4969 { 4970 return skb_shinfo(skb)->gso_size; 4971 } 4972 4973 /* Note: Should be called only if skb_is_gso(skb) is true */ 4974 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 4975 { 4976 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 4977 } 4978 4979 /* Note: Should be called only if skb_is_gso(skb) is true */ 4980 static inline bool skb_is_gso_sctp(const struct sk_buff *skb) 4981 { 4982 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP; 4983 } 4984 4985 /* Note: Should be called only if skb_is_gso(skb) is true */ 4986 static inline bool skb_is_gso_tcp(const struct sk_buff *skb) 4987 { 4988 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6); 4989 } 4990 4991 static inline void skb_gso_reset(struct sk_buff *skb) 4992 { 4993 skb_shinfo(skb)->gso_size = 0; 4994 skb_shinfo(skb)->gso_segs = 0; 4995 skb_shinfo(skb)->gso_type = 0; 4996 } 4997 4998 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo, 4999 u16 increment) 5000 { 5001 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 5002 return; 5003 shinfo->gso_size += increment; 5004 } 5005 5006 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo, 5007 u16 decrement) 5008 { 5009 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS)) 5010 return; 5011 shinfo->gso_size -= decrement; 5012 } 5013 5014 void __skb_warn_lro_forwarding(const struct sk_buff *skb); 5015 5016 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 5017 { 5018 /* LRO sets gso_size but not gso_type, whereas if GSO is really 5019 * wanted then gso_type will be set. */ 5020 const struct skb_shared_info *shinfo = skb_shinfo(skb); 5021 5022 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 5023 unlikely(shinfo->gso_type == 0)) { 5024 __skb_warn_lro_forwarding(skb); 5025 return true; 5026 } 5027 return false; 5028 } 5029 5030 static inline void skb_forward_csum(struct sk_buff *skb) 5031 { 5032 /* Unfortunately we don't support this one. Any brave souls? */ 5033 if (skb->ip_summed == CHECKSUM_COMPLETE) 5034 skb->ip_summed = CHECKSUM_NONE; 5035 } 5036 5037 /** 5038 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 5039 * @skb: skb to check 5040 * 5041 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 5042 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 5043 * use this helper, to document places where we make this assertion. 5044 */ 5045 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 5046 { 5047 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE); 5048 } 5049 5050 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 5051 5052 int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 5053 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, 5054 unsigned int transport_len, 5055 __sum16(*skb_chkf)(struct sk_buff *skb)); 5056 5057 /** 5058 * skb_head_is_locked - Determine if the skb->head is locked down 5059 * @skb: skb to check 5060 * 5061 * The head on skbs build around a head frag can be removed if they are 5062 * not cloned. This function returns true if the skb head is locked down 5063 * due to either being allocated via kmalloc, or by being a clone with 5064 * multiple references to the head. 5065 */ 5066 static inline bool skb_head_is_locked(const struct sk_buff *skb) 5067 { 5068 return !skb->head_frag || skb_cloned(skb); 5069 } 5070 5071 /* Local Checksum Offload. 5072 * Compute outer checksum based on the assumption that the 5073 * inner checksum will be offloaded later. 5074 * See Documentation/networking/checksum-offloads.rst for 5075 * explanation of how this works. 5076 * Fill in outer checksum adjustment (e.g. with sum of outer 5077 * pseudo-header) before calling. 5078 * Also ensure that inner checksum is in linear data area. 5079 */ 5080 static inline __wsum lco_csum(struct sk_buff *skb) 5081 { 5082 unsigned char *csum_start = skb_checksum_start(skb); 5083 unsigned char *l4_hdr = skb_transport_header(skb); 5084 __wsum partial; 5085 5086 /* Start with complement of inner checksum adjustment */ 5087 partial = ~csum_unfold(*(__force __sum16 *)(csum_start + 5088 skb->csum_offset)); 5089 5090 /* Add in checksum of our headers (incl. outer checksum 5091 * adjustment filled in by caller) and return result. 5092 */ 5093 return csum_partial(l4_hdr, csum_start - l4_hdr, partial); 5094 } 5095 5096 static inline bool skb_is_redirected(const struct sk_buff *skb) 5097 { 5098 return skb->redirected; 5099 } 5100 5101 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress) 5102 { 5103 skb->redirected = 1; 5104 #ifdef CONFIG_NET_REDIRECT 5105 skb->from_ingress = from_ingress; 5106 if (skb->from_ingress) 5107 skb_clear_tstamp(skb); 5108 #endif 5109 } 5110 5111 static inline void skb_reset_redirect(struct sk_buff *skb) 5112 { 5113 skb->redirected = 0; 5114 } 5115 5116 static inline bool skb_csum_is_sctp(struct sk_buff *skb) 5117 { 5118 return skb->csum_not_inet; 5119 } 5120 5121 static inline void skb_set_kcov_handle(struct sk_buff *skb, 5122 const u64 kcov_handle) 5123 { 5124 #ifdef CONFIG_KCOV 5125 skb->kcov_handle = kcov_handle; 5126 #endif 5127 } 5128 5129 static inline u64 skb_get_kcov_handle(struct sk_buff *skb) 5130 { 5131 #ifdef CONFIG_KCOV 5132 return skb->kcov_handle; 5133 #else 5134 return 0; 5135 #endif 5136 } 5137 5138 #ifdef CONFIG_PAGE_POOL 5139 static inline void skb_mark_for_recycle(struct sk_buff *skb) 5140 { 5141 skb->pp_recycle = 1; 5142 } 5143 #endif 5144 5145 static inline bool skb_pp_recycle(struct sk_buff *skb, void *data) 5146 { 5147 if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle) 5148 return false; 5149 return page_pool_return_skb_page(virt_to_page(data)); 5150 } 5151 5152 #endif /* __KERNEL__ */ 5153 #endif /* _LINUX_SKBUFF_H */ 5154