1 /* 2 * Definitions for the 'struct sk_buff' memory handlers. 3 * 4 * Authors: 5 * Alan Cox, <gw4pts@gw4pts.ampr.org> 6 * Florian La Roche, <rzsfl@rz.uni-sb.de> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #ifndef _LINUX_SKBUFF_H 15 #define _LINUX_SKBUFF_H 16 17 #include <linux/kernel.h> 18 #include <linux/kmemcheck.h> 19 #include <linux/compiler.h> 20 #include <linux/time.h> 21 #include <linux/bug.h> 22 #include <linux/cache.h> 23 #include <linux/rbtree.h> 24 #include <linux/socket.h> 25 26 #include <linux/atomic.h> 27 #include <asm/types.h> 28 #include <linux/spinlock.h> 29 #include <linux/net.h> 30 #include <linux/textsearch.h> 31 #include <net/checksum.h> 32 #include <linux/rcupdate.h> 33 #include <linux/hrtimer.h> 34 #include <linux/dma-mapping.h> 35 #include <linux/netdev_features.h> 36 #include <linux/sched.h> 37 #include <net/flow_dissector.h> 38 #include <linux/splice.h> 39 #include <linux/in6.h> 40 #include <net/flow.h> 41 42 /* A. Checksumming of received packets by device. 43 * 44 * CHECKSUM_NONE: 45 * 46 * Device failed to checksum this packet e.g. due to lack of capabilities. 47 * The packet contains full (though not verified) checksum in packet but 48 * not in skb->csum. Thus, skb->csum is undefined in this case. 49 * 50 * CHECKSUM_UNNECESSARY: 51 * 52 * The hardware you're dealing with doesn't calculate the full checksum 53 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums 54 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY 55 * if their checksums are okay. skb->csum is still undefined in this case 56 * though. It is a bad option, but, unfortunately, nowadays most vendors do 57 * this. Apparently with the secret goal to sell you new devices, when you 58 * will add new protocol to your host, f.e. IPv6 8) 59 * 60 * CHECKSUM_UNNECESSARY is applicable to following protocols: 61 * TCP: IPv6 and IPv4. 62 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a 63 * zero UDP checksum for either IPv4 or IPv6, the networking stack 64 * may perform further validation in this case. 65 * GRE: only if the checksum is present in the header. 66 * SCTP: indicates the CRC in SCTP header has been validated. 67 * 68 * skb->csum_level indicates the number of consecutive checksums found in 69 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY. 70 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet 71 * and a device is able to verify the checksums for UDP (possibly zero), 72 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to 73 * two. If the device were only able to verify the UDP checksum and not 74 * GRE, either because it doesn't support GRE checksum of because GRE 75 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is 76 * not considered in this case). 77 * 78 * CHECKSUM_COMPLETE: 79 * 80 * This is the most generic way. The device supplied checksum of the _whole_ 81 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the 82 * hardware doesn't need to parse L3/L4 headers to implement this. 83 * 84 * Note: Even if device supports only some protocols, but is able to produce 85 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 86 * 87 * CHECKSUM_PARTIAL: 88 * 89 * A checksum is set up to be offloaded to a device as described in the 90 * output description for CHECKSUM_PARTIAL. This may occur on a packet 91 * received directly from another Linux OS, e.g., a virtualized Linux kernel 92 * on the same host, or it may be set in the input path in GRO or remote 93 * checksum offload. For the purposes of checksum verification, the checksum 94 * referred to by skb->csum_start + skb->csum_offset and any preceding 95 * checksums in the packet are considered verified. Any checksums in the 96 * packet that are after the checksum being offloaded are not considered to 97 * be verified. 98 * 99 * B. Checksumming on output. 100 * 101 * CHECKSUM_NONE: 102 * 103 * The skb was already checksummed by the protocol, or a checksum is not 104 * required. 105 * 106 * CHECKSUM_PARTIAL: 107 * 108 * The device is required to checksum the packet as seen by hard_start_xmit() 109 * from skb->csum_start up to the end, and to record/write the checksum at 110 * offset skb->csum_start + skb->csum_offset. 111 * 112 * The device must show its capabilities in dev->features, set up at device 113 * setup time, e.g. netdev_features.h: 114 * 115 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything. 116 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over 117 * IPv4. Sigh. Vendors like this way for an unknown reason. 118 * Though, see comment above about CHECKSUM_UNNECESSARY. 8) 119 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead. 120 * NETIF_F_... - Well, you get the picture. 121 * 122 * CHECKSUM_UNNECESSARY: 123 * 124 * Normally, the device will do per protocol specific checksumming. Protocol 125 * implementations that do not want the NIC to perform the checksum 126 * calculation should use this flag in their outgoing skbs. 127 * 128 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC 129 * offload. Correspondingly, the FCoE protocol driver 130 * stack should use CHECKSUM_UNNECESSARY. 131 * 132 * Any questions? No questions, good. --ANK 133 */ 134 135 /* Don't change this without changing skb_csum_unnecessary! */ 136 #define CHECKSUM_NONE 0 137 #define CHECKSUM_UNNECESSARY 1 138 #define CHECKSUM_COMPLETE 2 139 #define CHECKSUM_PARTIAL 3 140 141 /* Maximum value in skb->csum_level */ 142 #define SKB_MAX_CSUM_LEVEL 3 143 144 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) 145 #define SKB_WITH_OVERHEAD(X) \ 146 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 147 #define SKB_MAX_ORDER(X, ORDER) \ 148 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 149 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 150 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 151 152 /* return minimum truesize of one skb containing X bytes of data */ 153 #define SKB_TRUESIZE(X) ((X) + \ 154 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 155 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 156 157 struct net_device; 158 struct scatterlist; 159 struct pipe_inode_info; 160 struct iov_iter; 161 struct napi_struct; 162 163 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 164 struct nf_conntrack { 165 atomic_t use; 166 }; 167 #endif 168 169 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 170 struct nf_bridge_info { 171 atomic_t use; 172 enum { 173 BRNF_PROTO_UNCHANGED, 174 BRNF_PROTO_8021Q, 175 BRNF_PROTO_PPPOE 176 } orig_proto:8; 177 u8 pkt_otherhost:1; 178 u8 in_prerouting:1; 179 u8 bridged_dnat:1; 180 __u16 frag_max_size; 181 struct net_device *physindev; 182 183 /* always valid & non-NULL from FORWARD on, for physdev match */ 184 struct net_device *physoutdev; 185 union { 186 /* prerouting: detect dnat in orig/reply direction */ 187 __be32 ipv4_daddr; 188 struct in6_addr ipv6_daddr; 189 190 /* after prerouting + nat detected: store original source 191 * mac since neigh resolution overwrites it, only used while 192 * skb is out in neigh layer. 193 */ 194 char neigh_header[8]; 195 }; 196 }; 197 #endif 198 199 struct sk_buff_head { 200 /* These two members must be first. */ 201 struct sk_buff *next; 202 struct sk_buff *prev; 203 204 __u32 qlen; 205 spinlock_t lock; 206 }; 207 208 struct sk_buff; 209 210 /* To allow 64K frame to be packed as single skb without frag_list we 211 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for 212 * buffers which do not start on a page boundary. 213 * 214 * Since GRO uses frags we allocate at least 16 regardless of page 215 * size. 216 */ 217 #if (65536/PAGE_SIZE + 1) < 16 218 #define MAX_SKB_FRAGS 16UL 219 #else 220 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) 221 #endif 222 223 typedef struct skb_frag_struct skb_frag_t; 224 225 struct skb_frag_struct { 226 struct { 227 struct page *p; 228 } page; 229 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 230 __u32 page_offset; 231 __u32 size; 232 #else 233 __u16 page_offset; 234 __u16 size; 235 #endif 236 }; 237 238 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 239 { 240 return frag->size; 241 } 242 243 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 244 { 245 frag->size = size; 246 } 247 248 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 249 { 250 frag->size += delta; 251 } 252 253 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 254 { 255 frag->size -= delta; 256 } 257 258 #define HAVE_HW_TIME_STAMP 259 260 /** 261 * struct skb_shared_hwtstamps - hardware time stamps 262 * @hwtstamp: hardware time stamp transformed into duration 263 * since arbitrary point in time 264 * 265 * Software time stamps generated by ktime_get_real() are stored in 266 * skb->tstamp. 267 * 268 * hwtstamps can only be compared against other hwtstamps from 269 * the same device. 270 * 271 * This structure is attached to packets as part of the 272 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 273 */ 274 struct skb_shared_hwtstamps { 275 ktime_t hwtstamp; 276 }; 277 278 /* Definitions for tx_flags in struct skb_shared_info */ 279 enum { 280 /* generate hardware time stamp */ 281 SKBTX_HW_TSTAMP = 1 << 0, 282 283 /* generate software time stamp when queueing packet to NIC */ 284 SKBTX_SW_TSTAMP = 1 << 1, 285 286 /* device driver is going to provide hardware time stamp */ 287 SKBTX_IN_PROGRESS = 1 << 2, 288 289 /* device driver supports TX zero-copy buffers */ 290 SKBTX_DEV_ZEROCOPY = 1 << 3, 291 292 /* generate wifi status information (where possible) */ 293 SKBTX_WIFI_STATUS = 1 << 4, 294 295 /* This indicates at least one fragment might be overwritten 296 * (as in vmsplice(), sendfile() ...) 297 * If we need to compute a TX checksum, we'll need to copy 298 * all frags to avoid possible bad checksum 299 */ 300 SKBTX_SHARED_FRAG = 1 << 5, 301 302 /* generate software time stamp when entering packet scheduling */ 303 SKBTX_SCHED_TSTAMP = 1 << 6, 304 305 /* generate software timestamp on peer data acknowledgment */ 306 SKBTX_ACK_TSTAMP = 1 << 7, 307 }; 308 309 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ 310 SKBTX_SCHED_TSTAMP | \ 311 SKBTX_ACK_TSTAMP) 312 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) 313 314 /* 315 * The callback notifies userspace to release buffers when skb DMA is done in 316 * lower device, the skb last reference should be 0 when calling this. 317 * The zerocopy_success argument is true if zero copy transmit occurred, 318 * false on data copy or out of memory error caused by data copy attempt. 319 * The ctx field is used to track device context. 320 * The desc field is used to track userspace buffer index. 321 */ 322 struct ubuf_info { 323 void (*callback)(struct ubuf_info *, bool zerocopy_success); 324 void *ctx; 325 unsigned long desc; 326 }; 327 328 /* This data is invariant across clones and lives at 329 * the end of the header data, ie. at skb->end. 330 */ 331 struct skb_shared_info { 332 unsigned char nr_frags; 333 __u8 tx_flags; 334 unsigned short gso_size; 335 /* Warning: this field is not always filled in (UFO)! */ 336 unsigned short gso_segs; 337 unsigned short gso_type; 338 struct sk_buff *frag_list; 339 struct skb_shared_hwtstamps hwtstamps; 340 u32 tskey; 341 __be32 ip6_frag_id; 342 343 /* 344 * Warning : all fields before dataref are cleared in __alloc_skb() 345 */ 346 atomic_t dataref; 347 348 /* Intermediate layers must ensure that destructor_arg 349 * remains valid until skb destructor */ 350 void * destructor_arg; 351 352 /* must be last field, see pskb_expand_head() */ 353 skb_frag_t frags[MAX_SKB_FRAGS]; 354 }; 355 356 /* We divide dataref into two halves. The higher 16 bits hold references 357 * to the payload part of skb->data. The lower 16 bits hold references to 358 * the entire skb->data. A clone of a headerless skb holds the length of 359 * the header in skb->hdr_len. 360 * 361 * All users must obey the rule that the skb->data reference count must be 362 * greater than or equal to the payload reference count. 363 * 364 * Holding a reference to the payload part means that the user does not 365 * care about modifications to the header part of skb->data. 366 */ 367 #define SKB_DATAREF_SHIFT 16 368 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 369 370 371 enum { 372 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ 373 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ 374 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ 375 }; 376 377 enum { 378 SKB_GSO_TCPV4 = 1 << 0, 379 SKB_GSO_UDP = 1 << 1, 380 381 /* This indicates the skb is from an untrusted source. */ 382 SKB_GSO_DODGY = 1 << 2, 383 384 /* This indicates the tcp segment has CWR set. */ 385 SKB_GSO_TCP_ECN = 1 << 3, 386 387 SKB_GSO_TCPV6 = 1 << 4, 388 389 SKB_GSO_FCOE = 1 << 5, 390 391 SKB_GSO_GRE = 1 << 6, 392 393 SKB_GSO_GRE_CSUM = 1 << 7, 394 395 SKB_GSO_IPIP = 1 << 8, 396 397 SKB_GSO_SIT = 1 << 9, 398 399 SKB_GSO_UDP_TUNNEL = 1 << 10, 400 401 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, 402 403 SKB_GSO_TUNNEL_REMCSUM = 1 << 12, 404 }; 405 406 #if BITS_PER_LONG > 32 407 #define NET_SKBUFF_DATA_USES_OFFSET 1 408 #endif 409 410 #ifdef NET_SKBUFF_DATA_USES_OFFSET 411 typedef unsigned int sk_buff_data_t; 412 #else 413 typedef unsigned char *sk_buff_data_t; 414 #endif 415 416 /** 417 * struct skb_mstamp - multi resolution time stamps 418 * @stamp_us: timestamp in us resolution 419 * @stamp_jiffies: timestamp in jiffies 420 */ 421 struct skb_mstamp { 422 union { 423 u64 v64; 424 struct { 425 u32 stamp_us; 426 u32 stamp_jiffies; 427 }; 428 }; 429 }; 430 431 /** 432 * skb_mstamp_get - get current timestamp 433 * @cl: place to store timestamps 434 */ 435 static inline void skb_mstamp_get(struct skb_mstamp *cl) 436 { 437 u64 val = local_clock(); 438 439 do_div(val, NSEC_PER_USEC); 440 cl->stamp_us = (u32)val; 441 cl->stamp_jiffies = (u32)jiffies; 442 } 443 444 /** 445 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp 446 * @t1: pointer to newest sample 447 * @t0: pointer to oldest sample 448 */ 449 static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1, 450 const struct skb_mstamp *t0) 451 { 452 s32 delta_us = t1->stamp_us - t0->stamp_us; 453 u32 delta_jiffies = t1->stamp_jiffies - t0->stamp_jiffies; 454 455 /* If delta_us is negative, this might be because interval is too big, 456 * or local_clock() drift is too big : fallback using jiffies. 457 */ 458 if (delta_us <= 0 || 459 delta_jiffies >= (INT_MAX / (USEC_PER_SEC / HZ))) 460 461 delta_us = jiffies_to_usecs(delta_jiffies); 462 463 return delta_us; 464 } 465 466 static inline bool skb_mstamp_after(const struct skb_mstamp *t1, 467 const struct skb_mstamp *t0) 468 { 469 s32 diff = t1->stamp_jiffies - t0->stamp_jiffies; 470 471 if (!diff) 472 diff = t1->stamp_us - t0->stamp_us; 473 return diff > 0; 474 } 475 476 /** 477 * struct sk_buff - socket buffer 478 * @next: Next buffer in list 479 * @prev: Previous buffer in list 480 * @tstamp: Time we arrived/left 481 * @rbnode: RB tree node, alternative to next/prev for netem/tcp 482 * @sk: Socket we are owned by 483 * @dev: Device we arrived on/are leaving by 484 * @cb: Control buffer. Free for use by every layer. Put private vars here 485 * @_skb_refdst: destination entry (with norefcount bit) 486 * @sp: the security path, used for xfrm 487 * @len: Length of actual data 488 * @data_len: Data length 489 * @mac_len: Length of link layer header 490 * @hdr_len: writable header length of cloned skb 491 * @csum: Checksum (must include start/offset pair) 492 * @csum_start: Offset from skb->head where checksumming should start 493 * @csum_offset: Offset from csum_start where checksum should be stored 494 * @priority: Packet queueing priority 495 * @ignore_df: allow local fragmentation 496 * @cloned: Head may be cloned (check refcnt to be sure) 497 * @ip_summed: Driver fed us an IP checksum 498 * @nohdr: Payload reference only, must not modify header 499 * @nfctinfo: Relationship of this skb to the connection 500 * @pkt_type: Packet class 501 * @fclone: skbuff clone status 502 * @ipvs_property: skbuff is owned by ipvs 503 * @peeked: this packet has been seen already, so stats have been 504 * done for it, don't do them again 505 * @nf_trace: netfilter packet trace flag 506 * @protocol: Packet protocol from driver 507 * @destructor: Destruct function 508 * @nfct: Associated connection, if any 509 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 510 * @skb_iif: ifindex of device we arrived on 511 * @tc_index: Traffic control index 512 * @tc_verd: traffic control verdict 513 * @hash: the packet hash 514 * @queue_mapping: Queue mapping for multiqueue devices 515 * @xmit_more: More SKBs are pending for this queue 516 * @ndisc_nodetype: router type (from link layer) 517 * @ooo_okay: allow the mapping of a socket to a queue to be changed 518 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport 519 * ports. 520 * @sw_hash: indicates hash was computed in software stack 521 * @wifi_acked_valid: wifi_acked was set 522 * @wifi_acked: whether frame was acked on wifi or not 523 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 524 * @napi_id: id of the NAPI struct this skb came from 525 * @secmark: security marking 526 * @offload_fwd_mark: fwding offload mark 527 * @mark: Generic packet mark 528 * @vlan_proto: vlan encapsulation protocol 529 * @vlan_tci: vlan tag control information 530 * @inner_protocol: Protocol (encapsulation) 531 * @inner_transport_header: Inner transport layer header (encapsulation) 532 * @inner_network_header: Network layer header (encapsulation) 533 * @inner_mac_header: Link layer header (encapsulation) 534 * @transport_header: Transport layer header 535 * @network_header: Network layer header 536 * @mac_header: Link layer header 537 * @tail: Tail pointer 538 * @end: End pointer 539 * @head: Head of buffer 540 * @data: Data head pointer 541 * @truesize: Buffer size 542 * @users: User count - see {datagram,tcp}.c 543 */ 544 545 struct sk_buff { 546 union { 547 struct { 548 /* These two members must be first. */ 549 struct sk_buff *next; 550 struct sk_buff *prev; 551 552 union { 553 ktime_t tstamp; 554 struct skb_mstamp skb_mstamp; 555 }; 556 }; 557 struct rb_node rbnode; /* used in netem & tcp stack */ 558 }; 559 struct sock *sk; 560 struct net_device *dev; 561 562 /* 563 * This is the control buffer. It is free to use for every 564 * layer. Please put your private variables there. If you 565 * want to keep them across layers you have to do a skb_clone() 566 * first. This is owned by whoever has the skb queued ATM. 567 */ 568 char cb[48] __aligned(8); 569 570 unsigned long _skb_refdst; 571 void (*destructor)(struct sk_buff *skb); 572 #ifdef CONFIG_XFRM 573 struct sec_path *sp; 574 #endif 575 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 576 struct nf_conntrack *nfct; 577 #endif 578 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 579 struct nf_bridge_info *nf_bridge; 580 #endif 581 unsigned int len, 582 data_len; 583 __u16 mac_len, 584 hdr_len; 585 586 /* Following fields are _not_ copied in __copy_skb_header() 587 * Note that queue_mapping is here mostly to fill a hole. 588 */ 589 kmemcheck_bitfield_begin(flags1); 590 __u16 queue_mapping; 591 __u8 cloned:1, 592 nohdr:1, 593 fclone:2, 594 peeked:1, 595 head_frag:1, 596 xmit_more:1; 597 /* one bit hole */ 598 kmemcheck_bitfield_end(flags1); 599 600 /* fields enclosed in headers_start/headers_end are copied 601 * using a single memcpy() in __copy_skb_header() 602 */ 603 /* private: */ 604 __u32 headers_start[0]; 605 /* public: */ 606 607 /* if you move pkt_type around you also must adapt those constants */ 608 #ifdef __BIG_ENDIAN_BITFIELD 609 #define PKT_TYPE_MAX (7 << 5) 610 #else 611 #define PKT_TYPE_MAX 7 612 #endif 613 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset) 614 615 __u8 __pkt_type_offset[0]; 616 __u8 pkt_type:3; 617 __u8 pfmemalloc:1; 618 __u8 ignore_df:1; 619 __u8 nfctinfo:3; 620 621 __u8 nf_trace:1; 622 __u8 ip_summed:2; 623 __u8 ooo_okay:1; 624 __u8 l4_hash:1; 625 __u8 sw_hash:1; 626 __u8 wifi_acked_valid:1; 627 __u8 wifi_acked:1; 628 629 __u8 no_fcs:1; 630 /* Indicates the inner headers are valid in the skbuff. */ 631 __u8 encapsulation:1; 632 __u8 encap_hdr_csum:1; 633 __u8 csum_valid:1; 634 __u8 csum_complete_sw:1; 635 __u8 csum_level:2; 636 __u8 csum_bad:1; 637 638 #ifdef CONFIG_IPV6_NDISC_NODETYPE 639 __u8 ndisc_nodetype:2; 640 #endif 641 __u8 ipvs_property:1; 642 __u8 inner_protocol_type:1; 643 __u8 remcsum_offload:1; 644 /* 3 or 5 bit hole */ 645 646 #ifdef CONFIG_NET_SCHED 647 __u16 tc_index; /* traffic control index */ 648 #ifdef CONFIG_NET_CLS_ACT 649 __u16 tc_verd; /* traffic control verdict */ 650 #endif 651 #endif 652 653 union { 654 __wsum csum; 655 struct { 656 __u16 csum_start; 657 __u16 csum_offset; 658 }; 659 }; 660 __u32 priority; 661 int skb_iif; 662 __u32 hash; 663 __be16 vlan_proto; 664 __u16 vlan_tci; 665 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS) 666 union { 667 unsigned int napi_id; 668 unsigned int sender_cpu; 669 }; 670 #endif 671 union { 672 #ifdef CONFIG_NETWORK_SECMARK 673 __u32 secmark; 674 #endif 675 #ifdef CONFIG_NET_SWITCHDEV 676 __u32 offload_fwd_mark; 677 #endif 678 }; 679 680 union { 681 __u32 mark; 682 __u32 reserved_tailroom; 683 }; 684 685 union { 686 __be16 inner_protocol; 687 __u8 inner_ipproto; 688 }; 689 690 __u16 inner_transport_header; 691 __u16 inner_network_header; 692 __u16 inner_mac_header; 693 694 __be16 protocol; 695 __u16 transport_header; 696 __u16 network_header; 697 __u16 mac_header; 698 699 /* private: */ 700 __u32 headers_end[0]; 701 /* public: */ 702 703 /* These elements must be at the end, see alloc_skb() for details. */ 704 sk_buff_data_t tail; 705 sk_buff_data_t end; 706 unsigned char *head, 707 *data; 708 unsigned int truesize; 709 atomic_t users; 710 }; 711 712 #ifdef __KERNEL__ 713 /* 714 * Handling routines are only of interest to the kernel 715 */ 716 #include <linux/slab.h> 717 718 719 #define SKB_ALLOC_FCLONE 0x01 720 #define SKB_ALLOC_RX 0x02 721 #define SKB_ALLOC_NAPI 0x04 722 723 /* Returns true if the skb was allocated from PFMEMALLOC reserves */ 724 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 725 { 726 return unlikely(skb->pfmemalloc); 727 } 728 729 /* 730 * skb might have a dst pointer attached, refcounted or not. 731 * _skb_refdst low order bit is set if refcount was _not_ taken 732 */ 733 #define SKB_DST_NOREF 1UL 734 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 735 736 /** 737 * skb_dst - returns skb dst_entry 738 * @skb: buffer 739 * 740 * Returns skb dst_entry, regardless of reference taken or not. 741 */ 742 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 743 { 744 /* If refdst was not refcounted, check we still are in a 745 * rcu_read_lock section 746 */ 747 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 748 !rcu_read_lock_held() && 749 !rcu_read_lock_bh_held()); 750 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 751 } 752 753 /** 754 * skb_dst_set - sets skb dst 755 * @skb: buffer 756 * @dst: dst entry 757 * 758 * Sets skb dst, assuming a reference was taken on dst and should 759 * be released by skb_dst_drop() 760 */ 761 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 762 { 763 skb->_skb_refdst = (unsigned long)dst; 764 } 765 766 /** 767 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 768 * @skb: buffer 769 * @dst: dst entry 770 * 771 * Sets skb dst, assuming a reference was not taken on dst. 772 * If dst entry is cached, we do not take reference and dst_release 773 * will be avoided by refdst_drop. If dst entry is not cached, we take 774 * reference, so that last dst_release can destroy the dst immediately. 775 */ 776 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 777 { 778 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 779 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 780 } 781 782 /** 783 * skb_dst_is_noref - Test if skb dst isn't refcounted 784 * @skb: buffer 785 */ 786 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 787 { 788 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 789 } 790 791 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 792 { 793 return (struct rtable *)skb_dst(skb); 794 } 795 796 void kfree_skb(struct sk_buff *skb); 797 void kfree_skb_list(struct sk_buff *segs); 798 void skb_tx_error(struct sk_buff *skb); 799 void consume_skb(struct sk_buff *skb); 800 void __kfree_skb(struct sk_buff *skb); 801 extern struct kmem_cache *skbuff_head_cache; 802 803 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 804 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 805 bool *fragstolen, int *delta_truesize); 806 807 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 808 int node); 809 struct sk_buff *__build_skb(void *data, unsigned int frag_size); 810 struct sk_buff *build_skb(void *data, unsigned int frag_size); 811 static inline struct sk_buff *alloc_skb(unsigned int size, 812 gfp_t priority) 813 { 814 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 815 } 816 817 struct sk_buff *alloc_skb_with_frags(unsigned long header_len, 818 unsigned long data_len, 819 int max_page_order, 820 int *errcode, 821 gfp_t gfp_mask); 822 823 /* Layout of fast clones : [skb1][skb2][fclone_ref] */ 824 struct sk_buff_fclones { 825 struct sk_buff skb1; 826 827 struct sk_buff skb2; 828 829 atomic_t fclone_ref; 830 }; 831 832 /** 833 * skb_fclone_busy - check if fclone is busy 834 * @skb: buffer 835 * 836 * Returns true is skb is a fast clone, and its clone is not freed. 837 * Some drivers call skb_orphan() in their ndo_start_xmit(), 838 * so we also check that this didnt happen. 839 */ 840 static inline bool skb_fclone_busy(const struct sock *sk, 841 const struct sk_buff *skb) 842 { 843 const struct sk_buff_fclones *fclones; 844 845 fclones = container_of(skb, struct sk_buff_fclones, skb1); 846 847 return skb->fclone == SKB_FCLONE_ORIG && 848 atomic_read(&fclones->fclone_ref) > 1 && 849 fclones->skb2.sk == sk; 850 } 851 852 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 853 gfp_t priority) 854 { 855 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 856 } 857 858 struct sk_buff *__alloc_skb_head(gfp_t priority, int node); 859 static inline struct sk_buff *alloc_skb_head(gfp_t priority) 860 { 861 return __alloc_skb_head(priority, -1); 862 } 863 864 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 865 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 866 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 867 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 868 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, 869 gfp_t gfp_mask, bool fclone); 870 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, 871 gfp_t gfp_mask) 872 { 873 return __pskb_copy_fclone(skb, headroom, gfp_mask, false); 874 } 875 876 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 877 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 878 unsigned int headroom); 879 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 880 int newtailroom, gfp_t priority); 881 int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, 882 int offset, int len); 883 int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, 884 int len); 885 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 886 int skb_pad(struct sk_buff *skb, int pad); 887 #define dev_kfree_skb(a) consume_skb(a) 888 889 int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 890 int getfrag(void *from, char *to, int offset, 891 int len, int odd, struct sk_buff *skb), 892 void *from, int length); 893 894 int skb_append_pagefrags(struct sk_buff *skb, struct page *page, 895 int offset, size_t size); 896 897 struct skb_seq_state { 898 __u32 lower_offset; 899 __u32 upper_offset; 900 __u32 frag_idx; 901 __u32 stepped_offset; 902 struct sk_buff *root_skb; 903 struct sk_buff *cur_skb; 904 __u8 *frag_data; 905 }; 906 907 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 908 unsigned int to, struct skb_seq_state *st); 909 unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 910 struct skb_seq_state *st); 911 void skb_abort_seq_read(struct skb_seq_state *st); 912 913 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 914 unsigned int to, struct ts_config *config); 915 916 /* 917 * Packet hash types specify the type of hash in skb_set_hash. 918 * 919 * Hash types refer to the protocol layer addresses which are used to 920 * construct a packet's hash. The hashes are used to differentiate or identify 921 * flows of the protocol layer for the hash type. Hash types are either 922 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 923 * 924 * Properties of hashes: 925 * 926 * 1) Two packets in different flows have different hash values 927 * 2) Two packets in the same flow should have the same hash value 928 * 929 * A hash at a higher layer is considered to be more specific. A driver should 930 * set the most specific hash possible. 931 * 932 * A driver cannot indicate a more specific hash than the layer at which a hash 933 * was computed. For instance an L3 hash cannot be set as an L4 hash. 934 * 935 * A driver may indicate a hash level which is less specific than the 936 * actual layer the hash was computed on. For instance, a hash computed 937 * at L4 may be considered an L3 hash. This should only be done if the 938 * driver can't unambiguously determine that the HW computed the hash at 939 * the higher layer. Note that the "should" in the second property above 940 * permits this. 941 */ 942 enum pkt_hash_types { 943 PKT_HASH_TYPE_NONE, /* Undefined type */ 944 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 945 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 946 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 947 }; 948 949 static inline void skb_clear_hash(struct sk_buff *skb) 950 { 951 skb->hash = 0; 952 skb->sw_hash = 0; 953 skb->l4_hash = 0; 954 } 955 956 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 957 { 958 if (!skb->l4_hash) 959 skb_clear_hash(skb); 960 } 961 962 static inline void 963 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4) 964 { 965 skb->l4_hash = is_l4; 966 skb->sw_hash = is_sw; 967 skb->hash = hash; 968 } 969 970 static inline void 971 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 972 { 973 /* Used by drivers to set hash from HW */ 974 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4); 975 } 976 977 static inline void 978 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4) 979 { 980 __skb_set_hash(skb, hash, true, is_l4); 981 } 982 983 void __skb_get_hash(struct sk_buff *skb); 984 u32 skb_get_poff(const struct sk_buff *skb); 985 u32 __skb_get_poff(const struct sk_buff *skb, void *data, 986 const struct flow_keys *keys, int hlen); 987 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 988 void *data, int hlen_proto); 989 990 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, 991 int thoff, u8 ip_proto) 992 { 993 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0); 994 } 995 996 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 997 const struct flow_dissector_key *key, 998 unsigned int key_count); 999 1000 bool __skb_flow_dissect(const struct sk_buff *skb, 1001 struct flow_dissector *flow_dissector, 1002 void *target_container, 1003 void *data, __be16 proto, int nhoff, int hlen, 1004 unsigned int flags); 1005 1006 static inline bool skb_flow_dissect(const struct sk_buff *skb, 1007 struct flow_dissector *flow_dissector, 1008 void *target_container, unsigned int flags) 1009 { 1010 return __skb_flow_dissect(skb, flow_dissector, target_container, 1011 NULL, 0, 0, 0, flags); 1012 } 1013 1014 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb, 1015 struct flow_keys *flow, 1016 unsigned int flags) 1017 { 1018 memset(flow, 0, sizeof(*flow)); 1019 return __skb_flow_dissect(skb, &flow_keys_dissector, flow, 1020 NULL, 0, 0, 0, flags); 1021 } 1022 1023 static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys *flow, 1024 void *data, __be16 proto, 1025 int nhoff, int hlen, 1026 unsigned int flags) 1027 { 1028 memset(flow, 0, sizeof(*flow)); 1029 return __skb_flow_dissect(NULL, &flow_keys_buf_dissector, flow, 1030 data, proto, nhoff, hlen, flags); 1031 } 1032 1033 static inline __u32 skb_get_hash(struct sk_buff *skb) 1034 { 1035 if (!skb->l4_hash && !skb->sw_hash) 1036 __skb_get_hash(skb); 1037 1038 return skb->hash; 1039 } 1040 1041 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6); 1042 1043 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 1044 { 1045 if (!skb->l4_hash && !skb->sw_hash) { 1046 struct flow_keys keys; 1047 __u32 hash = __get_hash_from_flowi6(fl6, &keys); 1048 1049 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1050 } 1051 1052 return skb->hash; 1053 } 1054 1055 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl); 1056 1057 static inline __u32 skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4) 1058 { 1059 if (!skb->l4_hash && !skb->sw_hash) { 1060 struct flow_keys keys; 1061 __u32 hash = __get_hash_from_flowi4(fl4, &keys); 1062 1063 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1064 } 1065 1066 return skb->hash; 1067 } 1068 1069 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb); 1070 1071 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 1072 { 1073 return skb->hash; 1074 } 1075 1076 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 1077 { 1078 to->hash = from->hash; 1079 to->sw_hash = from->sw_hash; 1080 to->l4_hash = from->l4_hash; 1081 }; 1082 1083 static inline void skb_sender_cpu_clear(struct sk_buff *skb) 1084 { 1085 #ifdef CONFIG_XPS 1086 skb->sender_cpu = 0; 1087 #endif 1088 } 1089 1090 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1091 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1092 { 1093 return skb->head + skb->end; 1094 } 1095 1096 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1097 { 1098 return skb->end; 1099 } 1100 #else 1101 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 1102 { 1103 return skb->end; 1104 } 1105 1106 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 1107 { 1108 return skb->end - skb->head; 1109 } 1110 #endif 1111 1112 /* Internal */ 1113 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 1114 1115 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 1116 { 1117 return &skb_shinfo(skb)->hwtstamps; 1118 } 1119 1120 /** 1121 * skb_queue_empty - check if a queue is empty 1122 * @list: queue head 1123 * 1124 * Returns true if the queue is empty, false otherwise. 1125 */ 1126 static inline int skb_queue_empty(const struct sk_buff_head *list) 1127 { 1128 return list->next == (const struct sk_buff *) list; 1129 } 1130 1131 /** 1132 * skb_queue_is_last - check if skb is the last entry in the queue 1133 * @list: queue head 1134 * @skb: buffer 1135 * 1136 * Returns true if @skb is the last buffer on the list. 1137 */ 1138 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 1139 const struct sk_buff *skb) 1140 { 1141 return skb->next == (const struct sk_buff *) list; 1142 } 1143 1144 /** 1145 * skb_queue_is_first - check if skb is the first entry in the queue 1146 * @list: queue head 1147 * @skb: buffer 1148 * 1149 * Returns true if @skb is the first buffer on the list. 1150 */ 1151 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 1152 const struct sk_buff *skb) 1153 { 1154 return skb->prev == (const struct sk_buff *) list; 1155 } 1156 1157 /** 1158 * skb_queue_next - return the next packet in the queue 1159 * @list: queue head 1160 * @skb: current buffer 1161 * 1162 * Return the next packet in @list after @skb. It is only valid to 1163 * call this if skb_queue_is_last() evaluates to false. 1164 */ 1165 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 1166 const struct sk_buff *skb) 1167 { 1168 /* This BUG_ON may seem severe, but if we just return then we 1169 * are going to dereference garbage. 1170 */ 1171 BUG_ON(skb_queue_is_last(list, skb)); 1172 return skb->next; 1173 } 1174 1175 /** 1176 * skb_queue_prev - return the prev packet in the queue 1177 * @list: queue head 1178 * @skb: current buffer 1179 * 1180 * Return the prev packet in @list before @skb. It is only valid to 1181 * call this if skb_queue_is_first() evaluates to false. 1182 */ 1183 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 1184 const struct sk_buff *skb) 1185 { 1186 /* This BUG_ON may seem severe, but if we just return then we 1187 * are going to dereference garbage. 1188 */ 1189 BUG_ON(skb_queue_is_first(list, skb)); 1190 return skb->prev; 1191 } 1192 1193 /** 1194 * skb_get - reference buffer 1195 * @skb: buffer to reference 1196 * 1197 * Makes another reference to a socket buffer and returns a pointer 1198 * to the buffer. 1199 */ 1200 static inline struct sk_buff *skb_get(struct sk_buff *skb) 1201 { 1202 atomic_inc(&skb->users); 1203 return skb; 1204 } 1205 1206 /* 1207 * If users == 1, we are the only owner and are can avoid redundant 1208 * atomic change. 1209 */ 1210 1211 /** 1212 * skb_cloned - is the buffer a clone 1213 * @skb: buffer to check 1214 * 1215 * Returns true if the buffer was generated with skb_clone() and is 1216 * one of multiple shared copies of the buffer. Cloned buffers are 1217 * shared data so must not be written to under normal circumstances. 1218 */ 1219 static inline int skb_cloned(const struct sk_buff *skb) 1220 { 1221 return skb->cloned && 1222 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 1223 } 1224 1225 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 1226 { 1227 might_sleep_if(gfpflags_allow_blocking(pri)); 1228 1229 if (skb_cloned(skb)) 1230 return pskb_expand_head(skb, 0, 0, pri); 1231 1232 return 0; 1233 } 1234 1235 /** 1236 * skb_header_cloned - is the header a clone 1237 * @skb: buffer to check 1238 * 1239 * Returns true if modifying the header part of the buffer requires 1240 * the data to be copied. 1241 */ 1242 static inline int skb_header_cloned(const struct sk_buff *skb) 1243 { 1244 int dataref; 1245 1246 if (!skb->cloned) 1247 return 0; 1248 1249 dataref = atomic_read(&skb_shinfo(skb)->dataref); 1250 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 1251 return dataref != 1; 1252 } 1253 1254 /** 1255 * skb_header_release - release reference to header 1256 * @skb: buffer to operate on 1257 * 1258 * Drop a reference to the header part of the buffer. This is done 1259 * by acquiring a payload reference. You must not read from the header 1260 * part of skb->data after this. 1261 * Note : Check if you can use __skb_header_release() instead. 1262 */ 1263 static inline void skb_header_release(struct sk_buff *skb) 1264 { 1265 BUG_ON(skb->nohdr); 1266 skb->nohdr = 1; 1267 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); 1268 } 1269 1270 /** 1271 * __skb_header_release - release reference to header 1272 * @skb: buffer to operate on 1273 * 1274 * Variant of skb_header_release() assuming skb is private to caller. 1275 * We can avoid one atomic operation. 1276 */ 1277 static inline void __skb_header_release(struct sk_buff *skb) 1278 { 1279 skb->nohdr = 1; 1280 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT)); 1281 } 1282 1283 1284 /** 1285 * skb_shared - is the buffer shared 1286 * @skb: buffer to check 1287 * 1288 * Returns true if more than one person has a reference to this 1289 * buffer. 1290 */ 1291 static inline int skb_shared(const struct sk_buff *skb) 1292 { 1293 return atomic_read(&skb->users) != 1; 1294 } 1295 1296 /** 1297 * skb_share_check - check if buffer is shared and if so clone it 1298 * @skb: buffer to check 1299 * @pri: priority for memory allocation 1300 * 1301 * If the buffer is shared the buffer is cloned and the old copy 1302 * drops a reference. A new clone with a single reference is returned. 1303 * If the buffer is not shared the original buffer is returned. When 1304 * being called from interrupt status or with spinlocks held pri must 1305 * be GFP_ATOMIC. 1306 * 1307 * NULL is returned on a memory allocation failure. 1308 */ 1309 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 1310 { 1311 might_sleep_if(gfpflags_allow_blocking(pri)); 1312 if (skb_shared(skb)) { 1313 struct sk_buff *nskb = skb_clone(skb, pri); 1314 1315 if (likely(nskb)) 1316 consume_skb(skb); 1317 else 1318 kfree_skb(skb); 1319 skb = nskb; 1320 } 1321 return skb; 1322 } 1323 1324 /* 1325 * Copy shared buffers into a new sk_buff. We effectively do COW on 1326 * packets to handle cases where we have a local reader and forward 1327 * and a couple of other messy ones. The normal one is tcpdumping 1328 * a packet thats being forwarded. 1329 */ 1330 1331 /** 1332 * skb_unshare - make a copy of a shared buffer 1333 * @skb: buffer to check 1334 * @pri: priority for memory allocation 1335 * 1336 * If the socket buffer is a clone then this function creates a new 1337 * copy of the data, drops a reference count on the old copy and returns 1338 * the new copy with the reference count at 1. If the buffer is not a clone 1339 * the original buffer is returned. When called with a spinlock held or 1340 * from interrupt state @pri must be %GFP_ATOMIC 1341 * 1342 * %NULL is returned on a memory allocation failure. 1343 */ 1344 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 1345 gfp_t pri) 1346 { 1347 might_sleep_if(gfpflags_allow_blocking(pri)); 1348 if (skb_cloned(skb)) { 1349 struct sk_buff *nskb = skb_copy(skb, pri); 1350 1351 /* Free our shared copy */ 1352 if (likely(nskb)) 1353 consume_skb(skb); 1354 else 1355 kfree_skb(skb); 1356 skb = nskb; 1357 } 1358 return skb; 1359 } 1360 1361 /** 1362 * skb_peek - peek at the head of an &sk_buff_head 1363 * @list_: list to peek at 1364 * 1365 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1366 * be careful with this one. A peek leaves the buffer on the 1367 * list and someone else may run off with it. You must hold 1368 * the appropriate locks or have a private queue to do this. 1369 * 1370 * Returns %NULL for an empty list or a pointer to the head element. 1371 * The reference count is not incremented and the reference is therefore 1372 * volatile. Use with caution. 1373 */ 1374 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 1375 { 1376 struct sk_buff *skb = list_->next; 1377 1378 if (skb == (struct sk_buff *)list_) 1379 skb = NULL; 1380 return skb; 1381 } 1382 1383 /** 1384 * skb_peek_next - peek skb following the given one from a queue 1385 * @skb: skb to start from 1386 * @list_: list to peek at 1387 * 1388 * Returns %NULL when the end of the list is met or a pointer to the 1389 * next element. The reference count is not incremented and the 1390 * reference is therefore volatile. Use with caution. 1391 */ 1392 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 1393 const struct sk_buff_head *list_) 1394 { 1395 struct sk_buff *next = skb->next; 1396 1397 if (next == (struct sk_buff *)list_) 1398 next = NULL; 1399 return next; 1400 } 1401 1402 /** 1403 * skb_peek_tail - peek at the tail of an &sk_buff_head 1404 * @list_: list to peek at 1405 * 1406 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1407 * be careful with this one. A peek leaves the buffer on the 1408 * list and someone else may run off with it. You must hold 1409 * the appropriate locks or have a private queue to do this. 1410 * 1411 * Returns %NULL for an empty list or a pointer to the tail element. 1412 * The reference count is not incremented and the reference is therefore 1413 * volatile. Use with caution. 1414 */ 1415 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 1416 { 1417 struct sk_buff *skb = list_->prev; 1418 1419 if (skb == (struct sk_buff *)list_) 1420 skb = NULL; 1421 return skb; 1422 1423 } 1424 1425 /** 1426 * skb_queue_len - get queue length 1427 * @list_: list to measure 1428 * 1429 * Return the length of an &sk_buff queue. 1430 */ 1431 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 1432 { 1433 return list_->qlen; 1434 } 1435 1436 /** 1437 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 1438 * @list: queue to initialize 1439 * 1440 * This initializes only the list and queue length aspects of 1441 * an sk_buff_head object. This allows to initialize the list 1442 * aspects of an sk_buff_head without reinitializing things like 1443 * the spinlock. It can also be used for on-stack sk_buff_head 1444 * objects where the spinlock is known to not be used. 1445 */ 1446 static inline void __skb_queue_head_init(struct sk_buff_head *list) 1447 { 1448 list->prev = list->next = (struct sk_buff *)list; 1449 list->qlen = 0; 1450 } 1451 1452 /* 1453 * This function creates a split out lock class for each invocation; 1454 * this is needed for now since a whole lot of users of the skb-queue 1455 * infrastructure in drivers have different locking usage (in hardirq) 1456 * than the networking core (in softirq only). In the long run either the 1457 * network layer or drivers should need annotation to consolidate the 1458 * main types of usage into 3 classes. 1459 */ 1460 static inline void skb_queue_head_init(struct sk_buff_head *list) 1461 { 1462 spin_lock_init(&list->lock); 1463 __skb_queue_head_init(list); 1464 } 1465 1466 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 1467 struct lock_class_key *class) 1468 { 1469 skb_queue_head_init(list); 1470 lockdep_set_class(&list->lock, class); 1471 } 1472 1473 /* 1474 * Insert an sk_buff on a list. 1475 * 1476 * The "__skb_xxxx()" functions are the non-atomic ones that 1477 * can only be called with interrupts disabled. 1478 */ 1479 void skb_insert(struct sk_buff *old, struct sk_buff *newsk, 1480 struct sk_buff_head *list); 1481 static inline void __skb_insert(struct sk_buff *newsk, 1482 struct sk_buff *prev, struct sk_buff *next, 1483 struct sk_buff_head *list) 1484 { 1485 newsk->next = next; 1486 newsk->prev = prev; 1487 next->prev = prev->next = newsk; 1488 list->qlen++; 1489 } 1490 1491 static inline void __skb_queue_splice(const struct sk_buff_head *list, 1492 struct sk_buff *prev, 1493 struct sk_buff *next) 1494 { 1495 struct sk_buff *first = list->next; 1496 struct sk_buff *last = list->prev; 1497 1498 first->prev = prev; 1499 prev->next = first; 1500 1501 last->next = next; 1502 next->prev = last; 1503 } 1504 1505 /** 1506 * skb_queue_splice - join two skb lists, this is designed for stacks 1507 * @list: the new list to add 1508 * @head: the place to add it in the first list 1509 */ 1510 static inline void skb_queue_splice(const struct sk_buff_head *list, 1511 struct sk_buff_head *head) 1512 { 1513 if (!skb_queue_empty(list)) { 1514 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1515 head->qlen += list->qlen; 1516 } 1517 } 1518 1519 /** 1520 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 1521 * @list: the new list to add 1522 * @head: the place to add it in the first list 1523 * 1524 * The list at @list is reinitialised 1525 */ 1526 static inline void skb_queue_splice_init(struct sk_buff_head *list, 1527 struct sk_buff_head *head) 1528 { 1529 if (!skb_queue_empty(list)) { 1530 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1531 head->qlen += list->qlen; 1532 __skb_queue_head_init(list); 1533 } 1534 } 1535 1536 /** 1537 * skb_queue_splice_tail - join two skb lists, each list being a queue 1538 * @list: the new list to add 1539 * @head: the place to add it in the first list 1540 */ 1541 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 1542 struct sk_buff_head *head) 1543 { 1544 if (!skb_queue_empty(list)) { 1545 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1546 head->qlen += list->qlen; 1547 } 1548 } 1549 1550 /** 1551 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 1552 * @list: the new list to add 1553 * @head: the place to add it in the first list 1554 * 1555 * Each of the lists is a queue. 1556 * The list at @list is reinitialised 1557 */ 1558 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 1559 struct sk_buff_head *head) 1560 { 1561 if (!skb_queue_empty(list)) { 1562 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1563 head->qlen += list->qlen; 1564 __skb_queue_head_init(list); 1565 } 1566 } 1567 1568 /** 1569 * __skb_queue_after - queue a buffer at the list head 1570 * @list: list to use 1571 * @prev: place after this buffer 1572 * @newsk: buffer to queue 1573 * 1574 * Queue a buffer int the middle of a list. This function takes no locks 1575 * and you must therefore hold required locks before calling it. 1576 * 1577 * A buffer cannot be placed on two lists at the same time. 1578 */ 1579 static inline void __skb_queue_after(struct sk_buff_head *list, 1580 struct sk_buff *prev, 1581 struct sk_buff *newsk) 1582 { 1583 __skb_insert(newsk, prev, prev->next, list); 1584 } 1585 1586 void skb_append(struct sk_buff *old, struct sk_buff *newsk, 1587 struct sk_buff_head *list); 1588 1589 static inline void __skb_queue_before(struct sk_buff_head *list, 1590 struct sk_buff *next, 1591 struct sk_buff *newsk) 1592 { 1593 __skb_insert(newsk, next->prev, next, list); 1594 } 1595 1596 /** 1597 * __skb_queue_head - queue a buffer at the list head 1598 * @list: list to use 1599 * @newsk: buffer to queue 1600 * 1601 * Queue a buffer at the start of a list. This function takes no locks 1602 * and you must therefore hold required locks before calling it. 1603 * 1604 * A buffer cannot be placed on two lists at the same time. 1605 */ 1606 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 1607 static inline void __skb_queue_head(struct sk_buff_head *list, 1608 struct sk_buff *newsk) 1609 { 1610 __skb_queue_after(list, (struct sk_buff *)list, newsk); 1611 } 1612 1613 /** 1614 * __skb_queue_tail - queue a buffer at the list tail 1615 * @list: list to use 1616 * @newsk: buffer to queue 1617 * 1618 * Queue a buffer at the end of a list. This function takes no locks 1619 * and you must therefore hold required locks before calling it. 1620 * 1621 * A buffer cannot be placed on two lists at the same time. 1622 */ 1623 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 1624 static inline void __skb_queue_tail(struct sk_buff_head *list, 1625 struct sk_buff *newsk) 1626 { 1627 __skb_queue_before(list, (struct sk_buff *)list, newsk); 1628 } 1629 1630 /* 1631 * remove sk_buff from list. _Must_ be called atomically, and with 1632 * the list known.. 1633 */ 1634 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 1635 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 1636 { 1637 struct sk_buff *next, *prev; 1638 1639 list->qlen--; 1640 next = skb->next; 1641 prev = skb->prev; 1642 skb->next = skb->prev = NULL; 1643 next->prev = prev; 1644 prev->next = next; 1645 } 1646 1647 /** 1648 * __skb_dequeue - remove from the head of the queue 1649 * @list: list to dequeue from 1650 * 1651 * Remove the head of the list. This function does not take any locks 1652 * so must be used with appropriate locks held only. The head item is 1653 * returned or %NULL if the list is empty. 1654 */ 1655 struct sk_buff *skb_dequeue(struct sk_buff_head *list); 1656 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 1657 { 1658 struct sk_buff *skb = skb_peek(list); 1659 if (skb) 1660 __skb_unlink(skb, list); 1661 return skb; 1662 } 1663 1664 /** 1665 * __skb_dequeue_tail - remove from the tail of the queue 1666 * @list: list to dequeue from 1667 * 1668 * Remove the tail of the list. This function does not take any locks 1669 * so must be used with appropriate locks held only. The tail item is 1670 * returned or %NULL if the list is empty. 1671 */ 1672 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 1673 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 1674 { 1675 struct sk_buff *skb = skb_peek_tail(list); 1676 if (skb) 1677 __skb_unlink(skb, list); 1678 return skb; 1679 } 1680 1681 1682 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 1683 { 1684 return skb->data_len; 1685 } 1686 1687 static inline unsigned int skb_headlen(const struct sk_buff *skb) 1688 { 1689 return skb->len - skb->data_len; 1690 } 1691 1692 static inline int skb_pagelen(const struct sk_buff *skb) 1693 { 1694 int i, len = 0; 1695 1696 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) 1697 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 1698 return len + skb_headlen(skb); 1699 } 1700 1701 /** 1702 * __skb_fill_page_desc - initialise a paged fragment in an skb 1703 * @skb: buffer containing fragment to be initialised 1704 * @i: paged fragment index to initialise 1705 * @page: the page to use for this fragment 1706 * @off: the offset to the data with @page 1707 * @size: the length of the data 1708 * 1709 * Initialises the @i'th fragment of @skb to point to &size bytes at 1710 * offset @off within @page. 1711 * 1712 * Does not take any additional reference on the fragment. 1713 */ 1714 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 1715 struct page *page, int off, int size) 1716 { 1717 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 1718 1719 /* 1720 * Propagate page pfmemalloc to the skb if we can. The problem is 1721 * that not all callers have unique ownership of the page but rely 1722 * on page_is_pfmemalloc doing the right thing(tm). 1723 */ 1724 frag->page.p = page; 1725 frag->page_offset = off; 1726 skb_frag_size_set(frag, size); 1727 1728 page = compound_head(page); 1729 if (page_is_pfmemalloc(page)) 1730 skb->pfmemalloc = true; 1731 } 1732 1733 /** 1734 * skb_fill_page_desc - initialise a paged fragment in an skb 1735 * @skb: buffer containing fragment to be initialised 1736 * @i: paged fragment index to initialise 1737 * @page: the page to use for this fragment 1738 * @off: the offset to the data with @page 1739 * @size: the length of the data 1740 * 1741 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 1742 * @skb to point to @size bytes at offset @off within @page. In 1743 * addition updates @skb such that @i is the last fragment. 1744 * 1745 * Does not take any additional reference on the fragment. 1746 */ 1747 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 1748 struct page *page, int off, int size) 1749 { 1750 __skb_fill_page_desc(skb, i, page, off, size); 1751 skb_shinfo(skb)->nr_frags = i + 1; 1752 } 1753 1754 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, 1755 int size, unsigned int truesize); 1756 1757 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 1758 unsigned int truesize); 1759 1760 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) 1761 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) 1762 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 1763 1764 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1765 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1766 { 1767 return skb->head + skb->tail; 1768 } 1769 1770 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1771 { 1772 skb->tail = skb->data - skb->head; 1773 } 1774 1775 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1776 { 1777 skb_reset_tail_pointer(skb); 1778 skb->tail += offset; 1779 } 1780 1781 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1782 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1783 { 1784 return skb->tail; 1785 } 1786 1787 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1788 { 1789 skb->tail = skb->data; 1790 } 1791 1792 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1793 { 1794 skb->tail = skb->data + offset; 1795 } 1796 1797 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1798 1799 /* 1800 * Add data to an sk_buff 1801 */ 1802 unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 1803 unsigned char *skb_put(struct sk_buff *skb, unsigned int len); 1804 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) 1805 { 1806 unsigned char *tmp = skb_tail_pointer(skb); 1807 SKB_LINEAR_ASSERT(skb); 1808 skb->tail += len; 1809 skb->len += len; 1810 return tmp; 1811 } 1812 1813 unsigned char *skb_push(struct sk_buff *skb, unsigned int len); 1814 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) 1815 { 1816 skb->data -= len; 1817 skb->len += len; 1818 return skb->data; 1819 } 1820 1821 unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); 1822 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) 1823 { 1824 skb->len -= len; 1825 BUG_ON(skb->len < skb->data_len); 1826 return skb->data += len; 1827 } 1828 1829 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) 1830 { 1831 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 1832 } 1833 1834 unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); 1835 1836 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) 1837 { 1838 if (len > skb_headlen(skb) && 1839 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 1840 return NULL; 1841 skb->len -= len; 1842 return skb->data += len; 1843 } 1844 1845 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) 1846 { 1847 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 1848 } 1849 1850 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) 1851 { 1852 if (likely(len <= skb_headlen(skb))) 1853 return 1; 1854 if (unlikely(len > skb->len)) 1855 return 0; 1856 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 1857 } 1858 1859 /** 1860 * skb_headroom - bytes at buffer head 1861 * @skb: buffer to check 1862 * 1863 * Return the number of bytes of free space at the head of an &sk_buff. 1864 */ 1865 static inline unsigned int skb_headroom(const struct sk_buff *skb) 1866 { 1867 return skb->data - skb->head; 1868 } 1869 1870 /** 1871 * skb_tailroom - bytes at buffer end 1872 * @skb: buffer to check 1873 * 1874 * Return the number of bytes of free space at the tail of an sk_buff 1875 */ 1876 static inline int skb_tailroom(const struct sk_buff *skb) 1877 { 1878 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 1879 } 1880 1881 /** 1882 * skb_availroom - bytes at buffer end 1883 * @skb: buffer to check 1884 * 1885 * Return the number of bytes of free space at the tail of an sk_buff 1886 * allocated by sk_stream_alloc() 1887 */ 1888 static inline int skb_availroom(const struct sk_buff *skb) 1889 { 1890 if (skb_is_nonlinear(skb)) 1891 return 0; 1892 1893 return skb->end - skb->tail - skb->reserved_tailroom; 1894 } 1895 1896 /** 1897 * skb_reserve - adjust headroom 1898 * @skb: buffer to alter 1899 * @len: bytes to move 1900 * 1901 * Increase the headroom of an empty &sk_buff by reducing the tail 1902 * room. This is only allowed for an empty buffer. 1903 */ 1904 static inline void skb_reserve(struct sk_buff *skb, int len) 1905 { 1906 skb->data += len; 1907 skb->tail += len; 1908 } 1909 1910 #define ENCAP_TYPE_ETHER 0 1911 #define ENCAP_TYPE_IPPROTO 1 1912 1913 static inline void skb_set_inner_protocol(struct sk_buff *skb, 1914 __be16 protocol) 1915 { 1916 skb->inner_protocol = protocol; 1917 skb->inner_protocol_type = ENCAP_TYPE_ETHER; 1918 } 1919 1920 static inline void skb_set_inner_ipproto(struct sk_buff *skb, 1921 __u8 ipproto) 1922 { 1923 skb->inner_ipproto = ipproto; 1924 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO; 1925 } 1926 1927 static inline void skb_reset_inner_headers(struct sk_buff *skb) 1928 { 1929 skb->inner_mac_header = skb->mac_header; 1930 skb->inner_network_header = skb->network_header; 1931 skb->inner_transport_header = skb->transport_header; 1932 } 1933 1934 static inline void skb_reset_mac_len(struct sk_buff *skb) 1935 { 1936 skb->mac_len = skb->network_header - skb->mac_header; 1937 } 1938 1939 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 1940 *skb) 1941 { 1942 return skb->head + skb->inner_transport_header; 1943 } 1944 1945 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 1946 { 1947 skb->inner_transport_header = skb->data - skb->head; 1948 } 1949 1950 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 1951 const int offset) 1952 { 1953 skb_reset_inner_transport_header(skb); 1954 skb->inner_transport_header += offset; 1955 } 1956 1957 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 1958 { 1959 return skb->head + skb->inner_network_header; 1960 } 1961 1962 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 1963 { 1964 skb->inner_network_header = skb->data - skb->head; 1965 } 1966 1967 static inline void skb_set_inner_network_header(struct sk_buff *skb, 1968 const int offset) 1969 { 1970 skb_reset_inner_network_header(skb); 1971 skb->inner_network_header += offset; 1972 } 1973 1974 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 1975 { 1976 return skb->head + skb->inner_mac_header; 1977 } 1978 1979 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 1980 { 1981 skb->inner_mac_header = skb->data - skb->head; 1982 } 1983 1984 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 1985 const int offset) 1986 { 1987 skb_reset_inner_mac_header(skb); 1988 skb->inner_mac_header += offset; 1989 } 1990 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 1991 { 1992 return skb->transport_header != (typeof(skb->transport_header))~0U; 1993 } 1994 1995 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1996 { 1997 return skb->head + skb->transport_header; 1998 } 1999 2000 static inline void skb_reset_transport_header(struct sk_buff *skb) 2001 { 2002 skb->transport_header = skb->data - skb->head; 2003 } 2004 2005 static inline void skb_set_transport_header(struct sk_buff *skb, 2006 const int offset) 2007 { 2008 skb_reset_transport_header(skb); 2009 skb->transport_header += offset; 2010 } 2011 2012 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 2013 { 2014 return skb->head + skb->network_header; 2015 } 2016 2017 static inline void skb_reset_network_header(struct sk_buff *skb) 2018 { 2019 skb->network_header = skb->data - skb->head; 2020 } 2021 2022 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 2023 { 2024 skb_reset_network_header(skb); 2025 skb->network_header += offset; 2026 } 2027 2028 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 2029 { 2030 return skb->head + skb->mac_header; 2031 } 2032 2033 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 2034 { 2035 return skb->mac_header != (typeof(skb->mac_header))~0U; 2036 } 2037 2038 static inline void skb_reset_mac_header(struct sk_buff *skb) 2039 { 2040 skb->mac_header = skb->data - skb->head; 2041 } 2042 2043 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 2044 { 2045 skb_reset_mac_header(skb); 2046 skb->mac_header += offset; 2047 } 2048 2049 static inline void skb_pop_mac_header(struct sk_buff *skb) 2050 { 2051 skb->mac_header = skb->network_header; 2052 } 2053 2054 static inline void skb_probe_transport_header(struct sk_buff *skb, 2055 const int offset_hint) 2056 { 2057 struct flow_keys keys; 2058 2059 if (skb_transport_header_was_set(skb)) 2060 return; 2061 else if (skb_flow_dissect_flow_keys(skb, &keys, 0)) 2062 skb_set_transport_header(skb, keys.control.thoff); 2063 else 2064 skb_set_transport_header(skb, offset_hint); 2065 } 2066 2067 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 2068 { 2069 if (skb_mac_header_was_set(skb)) { 2070 const unsigned char *old_mac = skb_mac_header(skb); 2071 2072 skb_set_mac_header(skb, -skb->mac_len); 2073 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 2074 } 2075 } 2076 2077 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 2078 { 2079 return skb->csum_start - skb_headroom(skb); 2080 } 2081 2082 static inline int skb_transport_offset(const struct sk_buff *skb) 2083 { 2084 return skb_transport_header(skb) - skb->data; 2085 } 2086 2087 static inline u32 skb_network_header_len(const struct sk_buff *skb) 2088 { 2089 return skb->transport_header - skb->network_header; 2090 } 2091 2092 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 2093 { 2094 return skb->inner_transport_header - skb->inner_network_header; 2095 } 2096 2097 static inline int skb_network_offset(const struct sk_buff *skb) 2098 { 2099 return skb_network_header(skb) - skb->data; 2100 } 2101 2102 static inline int skb_inner_network_offset(const struct sk_buff *skb) 2103 { 2104 return skb_inner_network_header(skb) - skb->data; 2105 } 2106 2107 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 2108 { 2109 return pskb_may_pull(skb, skb_network_offset(skb) + len); 2110 } 2111 2112 /* 2113 * CPUs often take a performance hit when accessing unaligned memory 2114 * locations. The actual performance hit varies, it can be small if the 2115 * hardware handles it or large if we have to take an exception and fix it 2116 * in software. 2117 * 2118 * Since an ethernet header is 14 bytes network drivers often end up with 2119 * the IP header at an unaligned offset. The IP header can be aligned by 2120 * shifting the start of the packet by 2 bytes. Drivers should do this 2121 * with: 2122 * 2123 * skb_reserve(skb, NET_IP_ALIGN); 2124 * 2125 * The downside to this alignment of the IP header is that the DMA is now 2126 * unaligned. On some architectures the cost of an unaligned DMA is high 2127 * and this cost outweighs the gains made by aligning the IP header. 2128 * 2129 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 2130 * to be overridden. 2131 */ 2132 #ifndef NET_IP_ALIGN 2133 #define NET_IP_ALIGN 2 2134 #endif 2135 2136 /* 2137 * The networking layer reserves some headroom in skb data (via 2138 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 2139 * the header has to grow. In the default case, if the header has to grow 2140 * 32 bytes or less we avoid the reallocation. 2141 * 2142 * Unfortunately this headroom changes the DMA alignment of the resulting 2143 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 2144 * on some architectures. An architecture can override this value, 2145 * perhaps setting it to a cacheline in size (since that will maintain 2146 * cacheline alignment of the DMA). It must be a power of 2. 2147 * 2148 * Various parts of the networking layer expect at least 32 bytes of 2149 * headroom, you should not reduce this. 2150 * 2151 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 2152 * to reduce average number of cache lines per packet. 2153 * get_rps_cpus() for example only access one 64 bytes aligned block : 2154 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 2155 */ 2156 #ifndef NET_SKB_PAD 2157 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 2158 #endif 2159 2160 int ___pskb_trim(struct sk_buff *skb, unsigned int len); 2161 2162 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 2163 { 2164 if (unlikely(skb_is_nonlinear(skb))) { 2165 WARN_ON(1); 2166 return; 2167 } 2168 skb->len = len; 2169 skb_set_tail_pointer(skb, len); 2170 } 2171 2172 void skb_trim(struct sk_buff *skb, unsigned int len); 2173 2174 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 2175 { 2176 if (skb->data_len) 2177 return ___pskb_trim(skb, len); 2178 __skb_trim(skb, len); 2179 return 0; 2180 } 2181 2182 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 2183 { 2184 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 2185 } 2186 2187 /** 2188 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 2189 * @skb: buffer to alter 2190 * @len: new length 2191 * 2192 * This is identical to pskb_trim except that the caller knows that 2193 * the skb is not cloned so we should never get an error due to out- 2194 * of-memory. 2195 */ 2196 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 2197 { 2198 int err = pskb_trim(skb, len); 2199 BUG_ON(err); 2200 } 2201 2202 /** 2203 * skb_orphan - orphan a buffer 2204 * @skb: buffer to orphan 2205 * 2206 * If a buffer currently has an owner then we call the owner's 2207 * destructor function and make the @skb unowned. The buffer continues 2208 * to exist but is no longer charged to its former owner. 2209 */ 2210 static inline void skb_orphan(struct sk_buff *skb) 2211 { 2212 if (skb->destructor) { 2213 skb->destructor(skb); 2214 skb->destructor = NULL; 2215 skb->sk = NULL; 2216 } else { 2217 BUG_ON(skb->sk); 2218 } 2219 } 2220 2221 /** 2222 * skb_orphan_frags - orphan the frags contained in a buffer 2223 * @skb: buffer to orphan frags from 2224 * @gfp_mask: allocation mask for replacement pages 2225 * 2226 * For each frag in the SKB which needs a destructor (i.e. has an 2227 * owner) create a copy of that frag and release the original 2228 * page by calling the destructor. 2229 */ 2230 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 2231 { 2232 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))) 2233 return 0; 2234 return skb_copy_ubufs(skb, gfp_mask); 2235 } 2236 2237 /** 2238 * __skb_queue_purge - empty a list 2239 * @list: list to empty 2240 * 2241 * Delete all buffers on an &sk_buff list. Each buffer is removed from 2242 * the list and one reference dropped. This function does not take the 2243 * list lock and the caller must hold the relevant locks to use it. 2244 */ 2245 void skb_queue_purge(struct sk_buff_head *list); 2246 static inline void __skb_queue_purge(struct sk_buff_head *list) 2247 { 2248 struct sk_buff *skb; 2249 while ((skb = __skb_dequeue(list)) != NULL) 2250 kfree_skb(skb); 2251 } 2252 2253 void *netdev_alloc_frag(unsigned int fragsz); 2254 2255 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 2256 gfp_t gfp_mask); 2257 2258 /** 2259 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 2260 * @dev: network device to receive on 2261 * @length: length to allocate 2262 * 2263 * Allocate a new &sk_buff and assign it a usage count of one. The 2264 * buffer has unspecified headroom built in. Users should allocate 2265 * the headroom they think they need without accounting for the 2266 * built in space. The built in space is used for optimisations. 2267 * 2268 * %NULL is returned if there is no free memory. Although this function 2269 * allocates memory it can be called from an interrupt. 2270 */ 2271 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 2272 unsigned int length) 2273 { 2274 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 2275 } 2276 2277 /* legacy helper around __netdev_alloc_skb() */ 2278 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 2279 gfp_t gfp_mask) 2280 { 2281 return __netdev_alloc_skb(NULL, length, gfp_mask); 2282 } 2283 2284 /* legacy helper around netdev_alloc_skb() */ 2285 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 2286 { 2287 return netdev_alloc_skb(NULL, length); 2288 } 2289 2290 2291 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 2292 unsigned int length, gfp_t gfp) 2293 { 2294 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 2295 2296 if (NET_IP_ALIGN && skb) 2297 skb_reserve(skb, NET_IP_ALIGN); 2298 return skb; 2299 } 2300 2301 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 2302 unsigned int length) 2303 { 2304 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 2305 } 2306 2307 static inline void skb_free_frag(void *addr) 2308 { 2309 __free_page_frag(addr); 2310 } 2311 2312 void *napi_alloc_frag(unsigned int fragsz); 2313 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, 2314 unsigned int length, gfp_t gfp_mask); 2315 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, 2316 unsigned int length) 2317 { 2318 return __napi_alloc_skb(napi, length, GFP_ATOMIC); 2319 } 2320 2321 /** 2322 * __dev_alloc_pages - allocate page for network Rx 2323 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 2324 * @order: size of the allocation 2325 * 2326 * Allocate a new page. 2327 * 2328 * %NULL is returned if there is no free memory. 2329 */ 2330 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask, 2331 unsigned int order) 2332 { 2333 /* This piece of code contains several assumptions. 2334 * 1. This is for device Rx, therefor a cold page is preferred. 2335 * 2. The expectation is the user wants a compound page. 2336 * 3. If requesting a order 0 page it will not be compound 2337 * due to the check to see if order has a value in prep_new_page 2338 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to 2339 * code in gfp_to_alloc_flags that should be enforcing this. 2340 */ 2341 gfp_mask |= __GFP_COLD | __GFP_COMP | __GFP_MEMALLOC; 2342 2343 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 2344 } 2345 2346 static inline struct page *dev_alloc_pages(unsigned int order) 2347 { 2348 return __dev_alloc_pages(GFP_ATOMIC, order); 2349 } 2350 2351 /** 2352 * __dev_alloc_page - allocate a page for network Rx 2353 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx 2354 * 2355 * Allocate a new page. 2356 * 2357 * %NULL is returned if there is no free memory. 2358 */ 2359 static inline struct page *__dev_alloc_page(gfp_t gfp_mask) 2360 { 2361 return __dev_alloc_pages(gfp_mask, 0); 2362 } 2363 2364 static inline struct page *dev_alloc_page(void) 2365 { 2366 return __dev_alloc_page(GFP_ATOMIC); 2367 } 2368 2369 /** 2370 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 2371 * @page: The page that was allocated from skb_alloc_page 2372 * @skb: The skb that may need pfmemalloc set 2373 */ 2374 static inline void skb_propagate_pfmemalloc(struct page *page, 2375 struct sk_buff *skb) 2376 { 2377 if (page_is_pfmemalloc(page)) 2378 skb->pfmemalloc = true; 2379 } 2380 2381 /** 2382 * skb_frag_page - retrieve the page referred to by a paged fragment 2383 * @frag: the paged fragment 2384 * 2385 * Returns the &struct page associated with @frag. 2386 */ 2387 static inline struct page *skb_frag_page(const skb_frag_t *frag) 2388 { 2389 return frag->page.p; 2390 } 2391 2392 /** 2393 * __skb_frag_ref - take an addition reference on a paged fragment. 2394 * @frag: the paged fragment 2395 * 2396 * Takes an additional reference on the paged fragment @frag. 2397 */ 2398 static inline void __skb_frag_ref(skb_frag_t *frag) 2399 { 2400 get_page(skb_frag_page(frag)); 2401 } 2402 2403 /** 2404 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 2405 * @skb: the buffer 2406 * @f: the fragment offset. 2407 * 2408 * Takes an additional reference on the @f'th paged fragment of @skb. 2409 */ 2410 static inline void skb_frag_ref(struct sk_buff *skb, int f) 2411 { 2412 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 2413 } 2414 2415 /** 2416 * __skb_frag_unref - release a reference on a paged fragment. 2417 * @frag: the paged fragment 2418 * 2419 * Releases a reference on the paged fragment @frag. 2420 */ 2421 static inline void __skb_frag_unref(skb_frag_t *frag) 2422 { 2423 put_page(skb_frag_page(frag)); 2424 } 2425 2426 /** 2427 * skb_frag_unref - release a reference on a paged fragment of an skb. 2428 * @skb: the buffer 2429 * @f: the fragment offset 2430 * 2431 * Releases a reference on the @f'th paged fragment of @skb. 2432 */ 2433 static inline void skb_frag_unref(struct sk_buff *skb, int f) 2434 { 2435 __skb_frag_unref(&skb_shinfo(skb)->frags[f]); 2436 } 2437 2438 /** 2439 * skb_frag_address - gets the address of the data contained in a paged fragment 2440 * @frag: the paged fragment buffer 2441 * 2442 * Returns the address of the data within @frag. The page must already 2443 * be mapped. 2444 */ 2445 static inline void *skb_frag_address(const skb_frag_t *frag) 2446 { 2447 return page_address(skb_frag_page(frag)) + frag->page_offset; 2448 } 2449 2450 /** 2451 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 2452 * @frag: the paged fragment buffer 2453 * 2454 * Returns the address of the data within @frag. Checks that the page 2455 * is mapped and returns %NULL otherwise. 2456 */ 2457 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 2458 { 2459 void *ptr = page_address(skb_frag_page(frag)); 2460 if (unlikely(!ptr)) 2461 return NULL; 2462 2463 return ptr + frag->page_offset; 2464 } 2465 2466 /** 2467 * __skb_frag_set_page - sets the page contained in a paged fragment 2468 * @frag: the paged fragment 2469 * @page: the page to set 2470 * 2471 * Sets the fragment @frag to contain @page. 2472 */ 2473 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page) 2474 { 2475 frag->page.p = page; 2476 } 2477 2478 /** 2479 * skb_frag_set_page - sets the page contained in a paged fragment of an skb 2480 * @skb: the buffer 2481 * @f: the fragment offset 2482 * @page: the page to set 2483 * 2484 * Sets the @f'th fragment of @skb to contain @page. 2485 */ 2486 static inline void skb_frag_set_page(struct sk_buff *skb, int f, 2487 struct page *page) 2488 { 2489 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page); 2490 } 2491 2492 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 2493 2494 /** 2495 * skb_frag_dma_map - maps a paged fragment via the DMA API 2496 * @dev: the device to map the fragment to 2497 * @frag: the paged fragment to map 2498 * @offset: the offset within the fragment (starting at the 2499 * fragment's own offset) 2500 * @size: the number of bytes to map 2501 * @dir: the direction of the mapping (%PCI_DMA_*) 2502 * 2503 * Maps the page associated with @frag to @device. 2504 */ 2505 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 2506 const skb_frag_t *frag, 2507 size_t offset, size_t size, 2508 enum dma_data_direction dir) 2509 { 2510 return dma_map_page(dev, skb_frag_page(frag), 2511 frag->page_offset + offset, size, dir); 2512 } 2513 2514 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 2515 gfp_t gfp_mask) 2516 { 2517 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 2518 } 2519 2520 2521 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb, 2522 gfp_t gfp_mask) 2523 { 2524 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true); 2525 } 2526 2527 2528 /** 2529 * skb_clone_writable - is the header of a clone writable 2530 * @skb: buffer to check 2531 * @len: length up to which to write 2532 * 2533 * Returns true if modifying the header part of the cloned buffer 2534 * does not requires the data to be copied. 2535 */ 2536 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 2537 { 2538 return !skb_header_cloned(skb) && 2539 skb_headroom(skb) + len <= skb->hdr_len; 2540 } 2541 2542 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 2543 int cloned) 2544 { 2545 int delta = 0; 2546 2547 if (headroom > skb_headroom(skb)) 2548 delta = headroom - skb_headroom(skb); 2549 2550 if (delta || cloned) 2551 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 2552 GFP_ATOMIC); 2553 return 0; 2554 } 2555 2556 /** 2557 * skb_cow - copy header of skb when it is required 2558 * @skb: buffer to cow 2559 * @headroom: needed headroom 2560 * 2561 * If the skb passed lacks sufficient headroom or its data part 2562 * is shared, data is reallocated. If reallocation fails, an error 2563 * is returned and original skb is not changed. 2564 * 2565 * The result is skb with writable area skb->head...skb->tail 2566 * and at least @headroom of space at head. 2567 */ 2568 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 2569 { 2570 return __skb_cow(skb, headroom, skb_cloned(skb)); 2571 } 2572 2573 /** 2574 * skb_cow_head - skb_cow but only making the head writable 2575 * @skb: buffer to cow 2576 * @headroom: needed headroom 2577 * 2578 * This function is identical to skb_cow except that we replace the 2579 * skb_cloned check by skb_header_cloned. It should be used when 2580 * you only need to push on some header and do not need to modify 2581 * the data. 2582 */ 2583 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 2584 { 2585 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 2586 } 2587 2588 /** 2589 * skb_padto - pad an skbuff up to a minimal size 2590 * @skb: buffer to pad 2591 * @len: minimal length 2592 * 2593 * Pads up a buffer to ensure the trailing bytes exist and are 2594 * blanked. If the buffer already contains sufficient data it 2595 * is untouched. Otherwise it is extended. Returns zero on 2596 * success. The skb is freed on error. 2597 */ 2598 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 2599 { 2600 unsigned int size = skb->len; 2601 if (likely(size >= len)) 2602 return 0; 2603 return skb_pad(skb, len - size); 2604 } 2605 2606 /** 2607 * skb_put_padto - increase size and pad an skbuff up to a minimal size 2608 * @skb: buffer to pad 2609 * @len: minimal length 2610 * 2611 * Pads up a buffer to ensure the trailing bytes exist and are 2612 * blanked. If the buffer already contains sufficient data it 2613 * is untouched. Otherwise it is extended. Returns zero on 2614 * success. The skb is freed on error. 2615 */ 2616 static inline int skb_put_padto(struct sk_buff *skb, unsigned int len) 2617 { 2618 unsigned int size = skb->len; 2619 2620 if (unlikely(size < len)) { 2621 len -= size; 2622 if (skb_pad(skb, len)) 2623 return -ENOMEM; 2624 __skb_put(skb, len); 2625 } 2626 return 0; 2627 } 2628 2629 static inline int skb_add_data(struct sk_buff *skb, 2630 struct iov_iter *from, int copy) 2631 { 2632 const int off = skb->len; 2633 2634 if (skb->ip_summed == CHECKSUM_NONE) { 2635 __wsum csum = 0; 2636 if (csum_and_copy_from_iter(skb_put(skb, copy), copy, 2637 &csum, from) == copy) { 2638 skb->csum = csum_block_add(skb->csum, csum, off); 2639 return 0; 2640 } 2641 } else if (copy_from_iter(skb_put(skb, copy), copy, from) == copy) 2642 return 0; 2643 2644 __skb_trim(skb, off); 2645 return -EFAULT; 2646 } 2647 2648 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 2649 const struct page *page, int off) 2650 { 2651 if (i) { 2652 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; 2653 2654 return page == skb_frag_page(frag) && 2655 off == frag->page_offset + skb_frag_size(frag); 2656 } 2657 return false; 2658 } 2659 2660 static inline int __skb_linearize(struct sk_buff *skb) 2661 { 2662 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 2663 } 2664 2665 /** 2666 * skb_linearize - convert paged skb to linear one 2667 * @skb: buffer to linarize 2668 * 2669 * If there is no free memory -ENOMEM is returned, otherwise zero 2670 * is returned and the old skb data released. 2671 */ 2672 static inline int skb_linearize(struct sk_buff *skb) 2673 { 2674 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 2675 } 2676 2677 /** 2678 * skb_has_shared_frag - can any frag be overwritten 2679 * @skb: buffer to test 2680 * 2681 * Return true if the skb has at least one frag that might be modified 2682 * by an external entity (as in vmsplice()/sendfile()) 2683 */ 2684 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 2685 { 2686 return skb_is_nonlinear(skb) && 2687 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; 2688 } 2689 2690 /** 2691 * skb_linearize_cow - make sure skb is linear and writable 2692 * @skb: buffer to process 2693 * 2694 * If there is no free memory -ENOMEM is returned, otherwise zero 2695 * is returned and the old skb data released. 2696 */ 2697 static inline int skb_linearize_cow(struct sk_buff *skb) 2698 { 2699 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 2700 __skb_linearize(skb) : 0; 2701 } 2702 2703 /** 2704 * skb_postpull_rcsum - update checksum for received skb after pull 2705 * @skb: buffer to update 2706 * @start: start of data before pull 2707 * @len: length of data pulled 2708 * 2709 * After doing a pull on a received packet, you need to call this to 2710 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 2711 * CHECKSUM_NONE so that it can be recomputed from scratch. 2712 */ 2713 2714 static inline void skb_postpull_rcsum(struct sk_buff *skb, 2715 const void *start, unsigned int len) 2716 { 2717 if (skb->ip_summed == CHECKSUM_COMPLETE) 2718 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); 2719 else if (skb->ip_summed == CHECKSUM_PARTIAL && 2720 skb_checksum_start_offset(skb) < 0) 2721 skb->ip_summed = CHECKSUM_NONE; 2722 } 2723 2724 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 2725 2726 /** 2727 * pskb_trim_rcsum - trim received skb and update checksum 2728 * @skb: buffer to trim 2729 * @len: new length 2730 * 2731 * This is exactly the same as pskb_trim except that it ensures the 2732 * checksum of received packets are still valid after the operation. 2733 */ 2734 2735 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 2736 { 2737 if (likely(len >= skb->len)) 2738 return 0; 2739 if (skb->ip_summed == CHECKSUM_COMPLETE) 2740 skb->ip_summed = CHECKSUM_NONE; 2741 return __pskb_trim(skb, len); 2742 } 2743 2744 #define skb_queue_walk(queue, skb) \ 2745 for (skb = (queue)->next; \ 2746 skb != (struct sk_buff *)(queue); \ 2747 skb = skb->next) 2748 2749 #define skb_queue_walk_safe(queue, skb, tmp) \ 2750 for (skb = (queue)->next, tmp = skb->next; \ 2751 skb != (struct sk_buff *)(queue); \ 2752 skb = tmp, tmp = skb->next) 2753 2754 #define skb_queue_walk_from(queue, skb) \ 2755 for (; skb != (struct sk_buff *)(queue); \ 2756 skb = skb->next) 2757 2758 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 2759 for (tmp = skb->next; \ 2760 skb != (struct sk_buff *)(queue); \ 2761 skb = tmp, tmp = skb->next) 2762 2763 #define skb_queue_reverse_walk(queue, skb) \ 2764 for (skb = (queue)->prev; \ 2765 skb != (struct sk_buff *)(queue); \ 2766 skb = skb->prev) 2767 2768 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 2769 for (skb = (queue)->prev, tmp = skb->prev; \ 2770 skb != (struct sk_buff *)(queue); \ 2771 skb = tmp, tmp = skb->prev) 2772 2773 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 2774 for (tmp = skb->prev; \ 2775 skb != (struct sk_buff *)(queue); \ 2776 skb = tmp, tmp = skb->prev) 2777 2778 static inline bool skb_has_frag_list(const struct sk_buff *skb) 2779 { 2780 return skb_shinfo(skb)->frag_list != NULL; 2781 } 2782 2783 static inline void skb_frag_list_init(struct sk_buff *skb) 2784 { 2785 skb_shinfo(skb)->frag_list = NULL; 2786 } 2787 2788 #define skb_walk_frags(skb, iter) \ 2789 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 2790 2791 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, 2792 int *peeked, int *off, int *err); 2793 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, 2794 int *err); 2795 unsigned int datagram_poll(struct file *file, struct socket *sock, 2796 struct poll_table_struct *wait); 2797 int skb_copy_datagram_iter(const struct sk_buff *from, int offset, 2798 struct iov_iter *to, int size); 2799 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, 2800 struct msghdr *msg, int size) 2801 { 2802 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size); 2803 } 2804 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, 2805 struct msghdr *msg); 2806 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, 2807 struct iov_iter *from, int len); 2808 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); 2809 void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 2810 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb); 2811 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 2812 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 2813 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 2814 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 2815 int len, __wsum csum); 2816 ssize_t skb_socket_splice(struct sock *sk, 2817 struct pipe_inode_info *pipe, 2818 struct splice_pipe_desc *spd); 2819 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, 2820 struct pipe_inode_info *pipe, unsigned int len, 2821 unsigned int flags, 2822 ssize_t (*splice_cb)(struct sock *, 2823 struct pipe_inode_info *, 2824 struct splice_pipe_desc *)); 2825 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 2826 unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 2827 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from, 2828 int len, int hlen); 2829 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 2830 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 2831 void skb_scrub_packet(struct sk_buff *skb, bool xnet); 2832 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb); 2833 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 2834 struct sk_buff *skb_vlan_untag(struct sk_buff *skb); 2835 int skb_ensure_writable(struct sk_buff *skb, int write_len); 2836 int skb_vlan_pop(struct sk_buff *skb); 2837 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); 2838 2839 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len) 2840 { 2841 return copy_from_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 2842 } 2843 2844 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len) 2845 { 2846 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT; 2847 } 2848 2849 struct skb_checksum_ops { 2850 __wsum (*update)(const void *mem, int len, __wsum wsum); 2851 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 2852 }; 2853 2854 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 2855 __wsum csum, const struct skb_checksum_ops *ops); 2856 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 2857 __wsum csum); 2858 2859 static inline void * __must_check 2860 __skb_header_pointer(const struct sk_buff *skb, int offset, 2861 int len, void *data, int hlen, void *buffer) 2862 { 2863 if (hlen - offset >= len) 2864 return data + offset; 2865 2866 if (!skb || 2867 skb_copy_bits(skb, offset, buffer, len) < 0) 2868 return NULL; 2869 2870 return buffer; 2871 } 2872 2873 static inline void * __must_check 2874 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer) 2875 { 2876 return __skb_header_pointer(skb, offset, len, skb->data, 2877 skb_headlen(skb), buffer); 2878 } 2879 2880 /** 2881 * skb_needs_linearize - check if we need to linearize a given skb 2882 * depending on the given device features. 2883 * @skb: socket buffer to check 2884 * @features: net device features 2885 * 2886 * Returns true if either: 2887 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 2888 * 2. skb is fragmented and the device does not support SG. 2889 */ 2890 static inline bool skb_needs_linearize(struct sk_buff *skb, 2891 netdev_features_t features) 2892 { 2893 return skb_is_nonlinear(skb) && 2894 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 2895 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 2896 } 2897 2898 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 2899 void *to, 2900 const unsigned int len) 2901 { 2902 memcpy(to, skb->data, len); 2903 } 2904 2905 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 2906 const int offset, void *to, 2907 const unsigned int len) 2908 { 2909 memcpy(to, skb->data + offset, len); 2910 } 2911 2912 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 2913 const void *from, 2914 const unsigned int len) 2915 { 2916 memcpy(skb->data, from, len); 2917 } 2918 2919 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 2920 const int offset, 2921 const void *from, 2922 const unsigned int len) 2923 { 2924 memcpy(skb->data + offset, from, len); 2925 } 2926 2927 void skb_init(void); 2928 2929 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 2930 { 2931 return skb->tstamp; 2932 } 2933 2934 /** 2935 * skb_get_timestamp - get timestamp from a skb 2936 * @skb: skb to get stamp from 2937 * @stamp: pointer to struct timeval to store stamp in 2938 * 2939 * Timestamps are stored in the skb as offsets to a base timestamp. 2940 * This function converts the offset back to a struct timeval and stores 2941 * it in stamp. 2942 */ 2943 static inline void skb_get_timestamp(const struct sk_buff *skb, 2944 struct timeval *stamp) 2945 { 2946 *stamp = ktime_to_timeval(skb->tstamp); 2947 } 2948 2949 static inline void skb_get_timestampns(const struct sk_buff *skb, 2950 struct timespec *stamp) 2951 { 2952 *stamp = ktime_to_timespec(skb->tstamp); 2953 } 2954 2955 static inline void __net_timestamp(struct sk_buff *skb) 2956 { 2957 skb->tstamp = ktime_get_real(); 2958 } 2959 2960 static inline ktime_t net_timedelta(ktime_t t) 2961 { 2962 return ktime_sub(ktime_get_real(), t); 2963 } 2964 2965 static inline ktime_t net_invalid_timestamp(void) 2966 { 2967 return ktime_set(0, 0); 2968 } 2969 2970 struct sk_buff *skb_clone_sk(struct sk_buff *skb); 2971 2972 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 2973 2974 void skb_clone_tx_timestamp(struct sk_buff *skb); 2975 bool skb_defer_rx_timestamp(struct sk_buff *skb); 2976 2977 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 2978 2979 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 2980 { 2981 } 2982 2983 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 2984 { 2985 return false; 2986 } 2987 2988 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 2989 2990 /** 2991 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 2992 * 2993 * PHY drivers may accept clones of transmitted packets for 2994 * timestamping via their phy_driver.txtstamp method. These drivers 2995 * must call this function to return the skb back to the stack with a 2996 * timestamp. 2997 * 2998 * @skb: clone of the the original outgoing packet 2999 * @hwtstamps: hardware time stamps 3000 * 3001 */ 3002 void skb_complete_tx_timestamp(struct sk_buff *skb, 3003 struct skb_shared_hwtstamps *hwtstamps); 3004 3005 void __skb_tstamp_tx(struct sk_buff *orig_skb, 3006 struct skb_shared_hwtstamps *hwtstamps, 3007 struct sock *sk, int tstype); 3008 3009 /** 3010 * skb_tstamp_tx - queue clone of skb with send time stamps 3011 * @orig_skb: the original outgoing packet 3012 * @hwtstamps: hardware time stamps, may be NULL if not available 3013 * 3014 * If the skb has a socket associated, then this function clones the 3015 * skb (thus sharing the actual data and optional structures), stores 3016 * the optional hardware time stamping information (if non NULL) or 3017 * generates a software time stamp (otherwise), then queues the clone 3018 * to the error queue of the socket. Errors are silently ignored. 3019 */ 3020 void skb_tstamp_tx(struct sk_buff *orig_skb, 3021 struct skb_shared_hwtstamps *hwtstamps); 3022 3023 static inline void sw_tx_timestamp(struct sk_buff *skb) 3024 { 3025 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && 3026 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 3027 skb_tstamp_tx(skb, NULL); 3028 } 3029 3030 /** 3031 * skb_tx_timestamp() - Driver hook for transmit timestamping 3032 * 3033 * Ethernet MAC Drivers should call this function in their hard_xmit() 3034 * function immediately before giving the sk_buff to the MAC hardware. 3035 * 3036 * Specifically, one should make absolutely sure that this function is 3037 * called before TX completion of this packet can trigger. Otherwise 3038 * the packet could potentially already be freed. 3039 * 3040 * @skb: A socket buffer. 3041 */ 3042 static inline void skb_tx_timestamp(struct sk_buff *skb) 3043 { 3044 skb_clone_tx_timestamp(skb); 3045 sw_tx_timestamp(skb); 3046 } 3047 3048 /** 3049 * skb_complete_wifi_ack - deliver skb with wifi status 3050 * 3051 * @skb: the original outgoing packet 3052 * @acked: ack status 3053 * 3054 */ 3055 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 3056 3057 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 3058 __sum16 __skb_checksum_complete(struct sk_buff *skb); 3059 3060 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 3061 { 3062 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) || 3063 skb->csum_valid || 3064 (skb->ip_summed == CHECKSUM_PARTIAL && 3065 skb_checksum_start_offset(skb) >= 0)); 3066 } 3067 3068 /** 3069 * skb_checksum_complete - Calculate checksum of an entire packet 3070 * @skb: packet to process 3071 * 3072 * This function calculates the checksum over the entire packet plus 3073 * the value of skb->csum. The latter can be used to supply the 3074 * checksum of a pseudo header as used by TCP/UDP. It returns the 3075 * checksum. 3076 * 3077 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 3078 * this function can be used to verify that checksum on received 3079 * packets. In that case the function should return zero if the 3080 * checksum is correct. In particular, this function will return zero 3081 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 3082 * hardware has already verified the correctness of the checksum. 3083 */ 3084 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 3085 { 3086 return skb_csum_unnecessary(skb) ? 3087 0 : __skb_checksum_complete(skb); 3088 } 3089 3090 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb) 3091 { 3092 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3093 if (skb->csum_level == 0) 3094 skb->ip_summed = CHECKSUM_NONE; 3095 else 3096 skb->csum_level--; 3097 } 3098 } 3099 3100 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb) 3101 { 3102 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { 3103 if (skb->csum_level < SKB_MAX_CSUM_LEVEL) 3104 skb->csum_level++; 3105 } else if (skb->ip_summed == CHECKSUM_NONE) { 3106 skb->ip_summed = CHECKSUM_UNNECESSARY; 3107 skb->csum_level = 0; 3108 } 3109 } 3110 3111 static inline void __skb_mark_checksum_bad(struct sk_buff *skb) 3112 { 3113 /* Mark current checksum as bad (typically called from GRO 3114 * path). In the case that ip_summed is CHECKSUM_NONE 3115 * this must be the first checksum encountered in the packet. 3116 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first 3117 * checksum after the last one validated. For UDP, a zero 3118 * checksum can not be marked as bad. 3119 */ 3120 3121 if (skb->ip_summed == CHECKSUM_NONE || 3122 skb->ip_summed == CHECKSUM_UNNECESSARY) 3123 skb->csum_bad = 1; 3124 } 3125 3126 /* Check if we need to perform checksum complete validation. 3127 * 3128 * Returns true if checksum complete is needed, false otherwise 3129 * (either checksum is unnecessary or zero checksum is allowed). 3130 */ 3131 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb, 3132 bool zero_okay, 3133 __sum16 check) 3134 { 3135 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) { 3136 skb->csum_valid = 1; 3137 __skb_decr_checksum_unnecessary(skb); 3138 return false; 3139 } 3140 3141 return true; 3142 } 3143 3144 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly 3145 * in checksum_init. 3146 */ 3147 #define CHECKSUM_BREAK 76 3148 3149 /* Unset checksum-complete 3150 * 3151 * Unset checksum complete can be done when packet is being modified 3152 * (uncompressed for instance) and checksum-complete value is 3153 * invalidated. 3154 */ 3155 static inline void skb_checksum_complete_unset(struct sk_buff *skb) 3156 { 3157 if (skb->ip_summed == CHECKSUM_COMPLETE) 3158 skb->ip_summed = CHECKSUM_NONE; 3159 } 3160 3161 /* Validate (init) checksum based on checksum complete. 3162 * 3163 * Return values: 3164 * 0: checksum is validated or try to in skb_checksum_complete. In the latter 3165 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo 3166 * checksum is stored in skb->csum for use in __skb_checksum_complete 3167 * non-zero: value of invalid checksum 3168 * 3169 */ 3170 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb, 3171 bool complete, 3172 __wsum psum) 3173 { 3174 if (skb->ip_summed == CHECKSUM_COMPLETE) { 3175 if (!csum_fold(csum_add(psum, skb->csum))) { 3176 skb->csum_valid = 1; 3177 return 0; 3178 } 3179 } else if (skb->csum_bad) { 3180 /* ip_summed == CHECKSUM_NONE in this case */ 3181 return (__force __sum16)1; 3182 } 3183 3184 skb->csum = psum; 3185 3186 if (complete || skb->len <= CHECKSUM_BREAK) { 3187 __sum16 csum; 3188 3189 csum = __skb_checksum_complete(skb); 3190 skb->csum_valid = !csum; 3191 return csum; 3192 } 3193 3194 return 0; 3195 } 3196 3197 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto) 3198 { 3199 return 0; 3200 } 3201 3202 /* Perform checksum validate (init). Note that this is a macro since we only 3203 * want to calculate the pseudo header which is an input function if necessary. 3204 * First we try to validate without any computation (checksum unnecessary) and 3205 * then calculate based on checksum complete calling the function to compute 3206 * pseudo header. 3207 * 3208 * Return values: 3209 * 0: checksum is validated or try to in skb_checksum_complete 3210 * non-zero: value of invalid checksum 3211 */ 3212 #define __skb_checksum_validate(skb, proto, complete, \ 3213 zero_okay, check, compute_pseudo) \ 3214 ({ \ 3215 __sum16 __ret = 0; \ 3216 skb->csum_valid = 0; \ 3217 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \ 3218 __ret = __skb_checksum_validate_complete(skb, \ 3219 complete, compute_pseudo(skb, proto)); \ 3220 __ret; \ 3221 }) 3222 3223 #define skb_checksum_init(skb, proto, compute_pseudo) \ 3224 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo) 3225 3226 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \ 3227 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo) 3228 3229 #define skb_checksum_validate(skb, proto, compute_pseudo) \ 3230 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo) 3231 3232 #define skb_checksum_validate_zero_check(skb, proto, check, \ 3233 compute_pseudo) \ 3234 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo) 3235 3236 #define skb_checksum_simple_validate(skb) \ 3237 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo) 3238 3239 static inline bool __skb_checksum_convert_check(struct sk_buff *skb) 3240 { 3241 return (skb->ip_summed == CHECKSUM_NONE && 3242 skb->csum_valid && !skb->csum_bad); 3243 } 3244 3245 static inline void __skb_checksum_convert(struct sk_buff *skb, 3246 __sum16 check, __wsum pseudo) 3247 { 3248 skb->csum = ~pseudo; 3249 skb->ip_summed = CHECKSUM_COMPLETE; 3250 } 3251 3252 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \ 3253 do { \ 3254 if (__skb_checksum_convert_check(skb)) \ 3255 __skb_checksum_convert(skb, check, \ 3256 compute_pseudo(skb, proto)); \ 3257 } while (0) 3258 3259 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr, 3260 u16 start, u16 offset) 3261 { 3262 skb->ip_summed = CHECKSUM_PARTIAL; 3263 skb->csum_start = ((unsigned char *)ptr + start) - skb->head; 3264 skb->csum_offset = offset - start; 3265 } 3266 3267 /* Update skbuf and packet to reflect the remote checksum offload operation. 3268 * When called, ptr indicates the starting point for skb->csum when 3269 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete 3270 * here, skb_postpull_rcsum is done so skb->csum start is ptr. 3271 */ 3272 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr, 3273 int start, int offset, bool nopartial) 3274 { 3275 __wsum delta; 3276 3277 if (!nopartial) { 3278 skb_remcsum_adjust_partial(skb, ptr, start, offset); 3279 return; 3280 } 3281 3282 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) { 3283 __skb_checksum_complete(skb); 3284 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data); 3285 } 3286 3287 delta = remcsum_adjust(ptr, skb->csum, start, offset); 3288 3289 /* Adjust skb->csum since we changed the packet */ 3290 skb->csum = csum_add(skb->csum, delta); 3291 } 3292 3293 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 3294 void nf_conntrack_destroy(struct nf_conntrack *nfct); 3295 static inline void nf_conntrack_put(struct nf_conntrack *nfct) 3296 { 3297 if (nfct && atomic_dec_and_test(&nfct->use)) 3298 nf_conntrack_destroy(nfct); 3299 } 3300 static inline void nf_conntrack_get(struct nf_conntrack *nfct) 3301 { 3302 if (nfct) 3303 atomic_inc(&nfct->use); 3304 } 3305 #endif 3306 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 3307 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) 3308 { 3309 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) 3310 kfree(nf_bridge); 3311 } 3312 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) 3313 { 3314 if (nf_bridge) 3315 atomic_inc(&nf_bridge->use); 3316 } 3317 #endif /* CONFIG_BRIDGE_NETFILTER */ 3318 static inline void nf_reset(struct sk_buff *skb) 3319 { 3320 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 3321 nf_conntrack_put(skb->nfct); 3322 skb->nfct = NULL; 3323 #endif 3324 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 3325 nf_bridge_put(skb->nf_bridge); 3326 skb->nf_bridge = NULL; 3327 #endif 3328 } 3329 3330 static inline void nf_reset_trace(struct sk_buff *skb) 3331 { 3332 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 3333 skb->nf_trace = 0; 3334 #endif 3335 } 3336 3337 /* Note: This doesn't put any conntrack and bridge info in dst. */ 3338 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src, 3339 bool copy) 3340 { 3341 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 3342 dst->nfct = src->nfct; 3343 nf_conntrack_get(src->nfct); 3344 if (copy) 3345 dst->nfctinfo = src->nfctinfo; 3346 #endif 3347 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 3348 dst->nf_bridge = src->nf_bridge; 3349 nf_bridge_get(src->nf_bridge); 3350 #endif 3351 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES) 3352 if (copy) 3353 dst->nf_trace = src->nf_trace; 3354 #endif 3355 } 3356 3357 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 3358 { 3359 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 3360 nf_conntrack_put(dst->nfct); 3361 #endif 3362 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 3363 nf_bridge_put(dst->nf_bridge); 3364 #endif 3365 __nf_copy(dst, src, true); 3366 } 3367 3368 #ifdef CONFIG_NETWORK_SECMARK 3369 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 3370 { 3371 to->secmark = from->secmark; 3372 } 3373 3374 static inline void skb_init_secmark(struct sk_buff *skb) 3375 { 3376 skb->secmark = 0; 3377 } 3378 #else 3379 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 3380 { } 3381 3382 static inline void skb_init_secmark(struct sk_buff *skb) 3383 { } 3384 #endif 3385 3386 static inline bool skb_irq_freeable(const struct sk_buff *skb) 3387 { 3388 return !skb->destructor && 3389 #if IS_ENABLED(CONFIG_XFRM) 3390 !skb->sp && 3391 #endif 3392 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 3393 !skb->nfct && 3394 #endif 3395 !skb->_skb_refdst && 3396 !skb_has_frag_list(skb); 3397 } 3398 3399 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 3400 { 3401 skb->queue_mapping = queue_mapping; 3402 } 3403 3404 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 3405 { 3406 return skb->queue_mapping; 3407 } 3408 3409 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 3410 { 3411 to->queue_mapping = from->queue_mapping; 3412 } 3413 3414 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 3415 { 3416 skb->queue_mapping = rx_queue + 1; 3417 } 3418 3419 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 3420 { 3421 return skb->queue_mapping - 1; 3422 } 3423 3424 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 3425 { 3426 return skb->queue_mapping != 0; 3427 } 3428 3429 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 3430 { 3431 #ifdef CONFIG_XFRM 3432 return skb->sp; 3433 #else 3434 return NULL; 3435 #endif 3436 } 3437 3438 /* Keeps track of mac header offset relative to skb->head. 3439 * It is useful for TSO of Tunneling protocol. e.g. GRE. 3440 * For non-tunnel skb it points to skb_mac_header() and for 3441 * tunnel skb it points to outer mac header. 3442 * Keeps track of level of encapsulation of network headers. 3443 */ 3444 struct skb_gso_cb { 3445 int mac_offset; 3446 int encap_level; 3447 __u16 csum_start; 3448 }; 3449 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb) 3450 3451 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) 3452 { 3453 return (skb_mac_header(inner_skb) - inner_skb->head) - 3454 SKB_GSO_CB(inner_skb)->mac_offset; 3455 } 3456 3457 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) 3458 { 3459 int new_headroom, headroom; 3460 int ret; 3461 3462 headroom = skb_headroom(skb); 3463 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); 3464 if (ret) 3465 return ret; 3466 3467 new_headroom = skb_headroom(skb); 3468 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); 3469 return 0; 3470 } 3471 3472 /* Compute the checksum for a gso segment. First compute the checksum value 3473 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and 3474 * then add in skb->csum (checksum from csum_start to end of packet). 3475 * skb->csum and csum_start are then updated to reflect the checksum of the 3476 * resultant packet starting from the transport header-- the resultant checksum 3477 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo 3478 * header. 3479 */ 3480 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) 3481 { 3482 int plen = SKB_GSO_CB(skb)->csum_start - skb_headroom(skb) - 3483 skb_transport_offset(skb); 3484 __wsum partial; 3485 3486 partial = csum_partial(skb_transport_header(skb), plen, skb->csum); 3487 skb->csum = res; 3488 SKB_GSO_CB(skb)->csum_start -= plen; 3489 3490 return csum_fold(partial); 3491 } 3492 3493 static inline bool skb_is_gso(const struct sk_buff *skb) 3494 { 3495 return skb_shinfo(skb)->gso_size; 3496 } 3497 3498 /* Note: Should be called only if skb_is_gso(skb) is true */ 3499 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 3500 { 3501 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 3502 } 3503 3504 void __skb_warn_lro_forwarding(const struct sk_buff *skb); 3505 3506 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 3507 { 3508 /* LRO sets gso_size but not gso_type, whereas if GSO is really 3509 * wanted then gso_type will be set. */ 3510 const struct skb_shared_info *shinfo = skb_shinfo(skb); 3511 3512 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 3513 unlikely(shinfo->gso_type == 0)) { 3514 __skb_warn_lro_forwarding(skb); 3515 return true; 3516 } 3517 return false; 3518 } 3519 3520 static inline void skb_forward_csum(struct sk_buff *skb) 3521 { 3522 /* Unfortunately we don't support this one. Any brave souls? */ 3523 if (skb->ip_summed == CHECKSUM_COMPLETE) 3524 skb->ip_summed = CHECKSUM_NONE; 3525 } 3526 3527 /** 3528 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 3529 * @skb: skb to check 3530 * 3531 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 3532 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 3533 * use this helper, to document places where we make this assertion. 3534 */ 3535 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 3536 { 3537 #ifdef DEBUG 3538 BUG_ON(skb->ip_summed != CHECKSUM_NONE); 3539 #endif 3540 } 3541 3542 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 3543 3544 int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 3545 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, 3546 unsigned int transport_len, 3547 __sum16(*skb_chkf)(struct sk_buff *skb)); 3548 3549 /** 3550 * skb_head_is_locked - Determine if the skb->head is locked down 3551 * @skb: skb to check 3552 * 3553 * The head on skbs build around a head frag can be removed if they are 3554 * not cloned. This function returns true if the skb head is locked down 3555 * due to either being allocated via kmalloc, or by being a clone with 3556 * multiple references to the head. 3557 */ 3558 static inline bool skb_head_is_locked(const struct sk_buff *skb) 3559 { 3560 return !skb->head_frag || skb_cloned(skb); 3561 } 3562 3563 /** 3564 * skb_gso_network_seglen - Return length of individual segments of a gso packet 3565 * 3566 * @skb: GSO skb 3567 * 3568 * skb_gso_network_seglen is used to determine the real size of the 3569 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP). 3570 * 3571 * The MAC/L2 header is not accounted for. 3572 */ 3573 static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb) 3574 { 3575 unsigned int hdr_len = skb_transport_header(skb) - 3576 skb_network_header(skb); 3577 return hdr_len + skb_gso_transport_seglen(skb); 3578 } 3579 3580 #endif /* __KERNEL__ */ 3581 #endif /* _LINUX_SKBUFF_H */ 3582