1 /* 2 * Definitions for the 'struct sk_buff' memory handlers. 3 * 4 * Authors: 5 * Alan Cox, <[email protected]> 6 * Florian La Roche, <[email protected]> 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 24 #include <linux/atomic.h> 25 #include <asm/types.h> 26 #include <linux/spinlock.h> 27 #include <linux/net.h> 28 #include <linux/textsearch.h> 29 #include <net/checksum.h> 30 #include <linux/rcupdate.h> 31 #include <linux/dmaengine.h> 32 #include <linux/hrtimer.h> 33 #include <linux/dma-mapping.h> 34 #include <linux/netdev_features.h> 35 #include <net/flow_keys.h> 36 37 /* A. Checksumming of received packets by device. 38 * 39 * CHECKSUM_NONE: 40 * 41 * Device failed to checksum this packet e.g. due to lack of capabilities. 42 * The packet contains full (though not verified) checksum in packet but 43 * not in skb->csum. Thus, skb->csum is undefined in this case. 44 * 45 * CHECKSUM_UNNECESSARY: 46 * 47 * The hardware you're dealing with doesn't calculate the full checksum 48 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums 49 * for specific protocols e.g. TCP/UDP/SCTP, then, for such packets it will 50 * set CHECKSUM_UNNECESSARY if their checksums are okay. skb->csum is still 51 * undefined in this case though. It is a bad option, but, unfortunately, 52 * nowadays most vendors do this. Apparently with the secret goal to sell 53 * you new devices, when you will add new protocol to your host, f.e. IPv6 8) 54 * 55 * CHECKSUM_COMPLETE: 56 * 57 * This is the most generic way. The device supplied checksum of the _whole_ 58 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the 59 * hardware doesn't need to parse L3/L4 headers to implement this. 60 * 61 * Note: Even if device supports only some protocols, but is able to produce 62 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY. 63 * 64 * CHECKSUM_PARTIAL: 65 * 66 * This is identical to the case for output below. This may occur on a packet 67 * received directly from another Linux OS, e.g., a virtualized Linux kernel 68 * on the same host. The packet can be treated in the same way as 69 * CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the 70 * checksum must be filled in by the OS or the hardware. 71 * 72 * B. Checksumming on output. 73 * 74 * CHECKSUM_NONE: 75 * 76 * The skb was already checksummed by the protocol, or a checksum is not 77 * required. 78 * 79 * CHECKSUM_PARTIAL: 80 * 81 * The device is required to checksum the packet as seen by hard_start_xmit() 82 * from skb->csum_start up to the end, and to record/write the checksum at 83 * offset skb->csum_start + skb->csum_offset. 84 * 85 * The device must show its capabilities in dev->features, set up at device 86 * setup time, e.g. netdev_features.h: 87 * 88 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything. 89 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over 90 * IPv4. Sigh. Vendors like this way for an unknown reason. 91 * Though, see comment above about CHECKSUM_UNNECESSARY. 8) 92 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead. 93 * NETIF_F_... - Well, you get the picture. 94 * 95 * CHECKSUM_UNNECESSARY: 96 * 97 * Normally, the device will do per protocol specific checksumming. Protocol 98 * implementations that do not want the NIC to perform the checksum 99 * calculation should use this flag in their outgoing skbs. 100 * 101 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC 102 * offload. Correspondingly, the FCoE protocol driver 103 * stack should use CHECKSUM_UNNECESSARY. 104 * 105 * Any questions? No questions, good. --ANK 106 */ 107 108 /* Don't change this without changing skb_csum_unnecessary! */ 109 #define CHECKSUM_NONE 0 110 #define CHECKSUM_UNNECESSARY 1 111 #define CHECKSUM_COMPLETE 2 112 #define CHECKSUM_PARTIAL 3 113 114 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ 115 ~(SMP_CACHE_BYTES - 1)) 116 #define SKB_WITH_OVERHEAD(X) \ 117 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 118 #define SKB_MAX_ORDER(X, ORDER) \ 119 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 120 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 121 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 122 123 /* return minimum truesize of one skb containing X bytes of data */ 124 #define SKB_TRUESIZE(X) ((X) + \ 125 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 126 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 127 128 struct net_device; 129 struct scatterlist; 130 struct pipe_inode_info; 131 132 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 133 struct nf_conntrack { 134 atomic_t use; 135 }; 136 #endif 137 138 #ifdef CONFIG_BRIDGE_NETFILTER 139 struct nf_bridge_info { 140 atomic_t use; 141 unsigned int mask; 142 struct net_device *physindev; 143 struct net_device *physoutdev; 144 unsigned long data[32 / sizeof(unsigned long)]; 145 }; 146 #endif 147 148 struct sk_buff_head { 149 /* These two members must be first. */ 150 struct sk_buff *next; 151 struct sk_buff *prev; 152 153 __u32 qlen; 154 spinlock_t lock; 155 }; 156 157 struct sk_buff; 158 159 /* To allow 64K frame to be packed as single skb without frag_list we 160 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for 161 * buffers which do not start on a page boundary. 162 * 163 * Since GRO uses frags we allocate at least 16 regardless of page 164 * size. 165 */ 166 #if (65536/PAGE_SIZE + 1) < 16 167 #define MAX_SKB_FRAGS 16UL 168 #else 169 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) 170 #endif 171 172 typedef struct skb_frag_struct skb_frag_t; 173 174 struct skb_frag_struct { 175 struct { 176 struct page *p; 177 } page; 178 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 179 __u32 page_offset; 180 __u32 size; 181 #else 182 __u16 page_offset; 183 __u16 size; 184 #endif 185 }; 186 187 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 188 { 189 return frag->size; 190 } 191 192 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 193 { 194 frag->size = size; 195 } 196 197 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 198 { 199 frag->size += delta; 200 } 201 202 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 203 { 204 frag->size -= delta; 205 } 206 207 #define HAVE_HW_TIME_STAMP 208 209 /** 210 * struct skb_shared_hwtstamps - hardware time stamps 211 * @hwtstamp: hardware time stamp transformed into duration 212 * since arbitrary point in time 213 * @syststamp: hwtstamp transformed to system time base 214 * 215 * Software time stamps generated by ktime_get_real() are stored in 216 * skb->tstamp. The relation between the different kinds of time 217 * stamps is as follows: 218 * 219 * syststamp and tstamp can be compared against each other in 220 * arbitrary combinations. The accuracy of a 221 * syststamp/tstamp/"syststamp from other device" comparison is 222 * limited by the accuracy of the transformation into system time 223 * base. This depends on the device driver and its underlying 224 * hardware. 225 * 226 * hwtstamps can only be compared against other hwtstamps from 227 * the same device. 228 * 229 * This structure is attached to packets as part of the 230 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 231 */ 232 struct skb_shared_hwtstamps { 233 ktime_t hwtstamp; 234 ktime_t syststamp; 235 }; 236 237 /* Definitions for tx_flags in struct skb_shared_info */ 238 enum { 239 /* generate hardware time stamp */ 240 SKBTX_HW_TSTAMP = 1 << 0, 241 242 /* generate software time stamp */ 243 SKBTX_SW_TSTAMP = 1 << 1, 244 245 /* device driver is going to provide hardware time stamp */ 246 SKBTX_IN_PROGRESS = 1 << 2, 247 248 /* device driver supports TX zero-copy buffers */ 249 SKBTX_DEV_ZEROCOPY = 1 << 3, 250 251 /* generate wifi status information (where possible) */ 252 SKBTX_WIFI_STATUS = 1 << 4, 253 254 /* This indicates at least one fragment might be overwritten 255 * (as in vmsplice(), sendfile() ...) 256 * If we need to compute a TX checksum, we'll need to copy 257 * all frags to avoid possible bad checksum 258 */ 259 SKBTX_SHARED_FRAG = 1 << 5, 260 }; 261 262 /* 263 * The callback notifies userspace to release buffers when skb DMA is done in 264 * lower device, the skb last reference should be 0 when calling this. 265 * The zerocopy_success argument is true if zero copy transmit occurred, 266 * false on data copy or out of memory error caused by data copy attempt. 267 * The ctx field is used to track device context. 268 * The desc field is used to track userspace buffer index. 269 */ 270 struct ubuf_info { 271 void (*callback)(struct ubuf_info *, bool zerocopy_success); 272 void *ctx; 273 unsigned long desc; 274 }; 275 276 /* This data is invariant across clones and lives at 277 * the end of the header data, ie. at skb->end. 278 */ 279 struct skb_shared_info { 280 unsigned char nr_frags; 281 __u8 tx_flags; 282 unsigned short gso_size; 283 /* Warning: this field is not always filled in (UFO)! */ 284 unsigned short gso_segs; 285 unsigned short gso_type; 286 struct sk_buff *frag_list; 287 struct skb_shared_hwtstamps hwtstamps; 288 __be32 ip6_frag_id; 289 290 /* 291 * Warning : all fields before dataref are cleared in __alloc_skb() 292 */ 293 atomic_t dataref; 294 295 /* Intermediate layers must ensure that destructor_arg 296 * remains valid until skb destructor */ 297 void * destructor_arg; 298 299 /* must be last field, see pskb_expand_head() */ 300 skb_frag_t frags[MAX_SKB_FRAGS]; 301 }; 302 303 /* We divide dataref into two halves. The higher 16 bits hold references 304 * to the payload part of skb->data. The lower 16 bits hold references to 305 * the entire skb->data. A clone of a headerless skb holds the length of 306 * the header in skb->hdr_len. 307 * 308 * All users must obey the rule that the skb->data reference count must be 309 * greater than or equal to the payload reference count. 310 * 311 * Holding a reference to the payload part means that the user does not 312 * care about modifications to the header part of skb->data. 313 */ 314 #define SKB_DATAREF_SHIFT 16 315 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 316 317 318 enum { 319 SKB_FCLONE_UNAVAILABLE, 320 SKB_FCLONE_ORIG, 321 SKB_FCLONE_CLONE, 322 }; 323 324 enum { 325 SKB_GSO_TCPV4 = 1 << 0, 326 SKB_GSO_UDP = 1 << 1, 327 328 /* This indicates the skb is from an untrusted source. */ 329 SKB_GSO_DODGY = 1 << 2, 330 331 /* This indicates the tcp segment has CWR set. */ 332 SKB_GSO_TCP_ECN = 1 << 3, 333 334 SKB_GSO_TCPV6 = 1 << 4, 335 336 SKB_GSO_FCOE = 1 << 5, 337 338 SKB_GSO_GRE = 1 << 6, 339 340 SKB_GSO_IPIP = 1 << 7, 341 342 SKB_GSO_SIT = 1 << 8, 343 344 SKB_GSO_UDP_TUNNEL = 1 << 9, 345 346 SKB_GSO_MPLS = 1 << 10, 347 }; 348 349 #if BITS_PER_LONG > 32 350 #define NET_SKBUFF_DATA_USES_OFFSET 1 351 #endif 352 353 #ifdef NET_SKBUFF_DATA_USES_OFFSET 354 typedef unsigned int sk_buff_data_t; 355 #else 356 typedef unsigned char *sk_buff_data_t; 357 #endif 358 359 /** 360 * struct sk_buff - socket buffer 361 * @next: Next buffer in list 362 * @prev: Previous buffer in list 363 * @tstamp: Time we arrived 364 * @sk: Socket we are owned by 365 * @dev: Device we arrived on/are leaving by 366 * @cb: Control buffer. Free for use by every layer. Put private vars here 367 * @_skb_refdst: destination entry (with norefcount bit) 368 * @sp: the security path, used for xfrm 369 * @len: Length of actual data 370 * @data_len: Data length 371 * @mac_len: Length of link layer header 372 * @hdr_len: writable header length of cloned skb 373 * @csum: Checksum (must include start/offset pair) 374 * @csum_start: Offset from skb->head where checksumming should start 375 * @csum_offset: Offset from csum_start where checksum should be stored 376 * @priority: Packet queueing priority 377 * @local_df: allow local fragmentation 378 * @cloned: Head may be cloned (check refcnt to be sure) 379 * @ip_summed: Driver fed us an IP checksum 380 * @nohdr: Payload reference only, must not modify header 381 * @nfctinfo: Relationship of this skb to the connection 382 * @pkt_type: Packet class 383 * @fclone: skbuff clone status 384 * @ipvs_property: skbuff is owned by ipvs 385 * @peeked: this packet has been seen already, so stats have been 386 * done for it, don't do them again 387 * @nf_trace: netfilter packet trace flag 388 * @protocol: Packet protocol from driver 389 * @destructor: Destruct function 390 * @nfct: Associated connection, if any 391 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 392 * @skb_iif: ifindex of device we arrived on 393 * @tc_index: Traffic control index 394 * @tc_verd: traffic control verdict 395 * @rxhash: the packet hash computed on receive 396 * @queue_mapping: Queue mapping for multiqueue devices 397 * @ndisc_nodetype: router type (from link layer) 398 * @ooo_okay: allow the mapping of a socket to a queue to be changed 399 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport 400 * ports. 401 * @wifi_acked_valid: wifi_acked was set 402 * @wifi_acked: whether frame was acked on wifi or not 403 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 404 * @dma_cookie: a cookie to one of several possible DMA operations 405 * done by skb DMA functions 406 * @napi_id: id of the NAPI struct this skb came from 407 * @secmark: security marking 408 * @mark: Generic packet mark 409 * @dropcount: total number of sk_receive_queue overflows 410 * @vlan_proto: vlan encapsulation protocol 411 * @vlan_tci: vlan tag control information 412 * @inner_protocol: Protocol (encapsulation) 413 * @inner_transport_header: Inner transport layer header (encapsulation) 414 * @inner_network_header: Network layer header (encapsulation) 415 * @inner_mac_header: Link layer header (encapsulation) 416 * @transport_header: Transport layer header 417 * @network_header: Network layer header 418 * @mac_header: Link layer header 419 * @tail: Tail pointer 420 * @end: End pointer 421 * @head: Head of buffer 422 * @data: Data head pointer 423 * @truesize: Buffer size 424 * @users: User count - see {datagram,tcp}.c 425 */ 426 427 struct sk_buff { 428 /* These two members must be first. */ 429 struct sk_buff *next; 430 struct sk_buff *prev; 431 432 ktime_t tstamp; 433 434 struct sock *sk; 435 struct net_device *dev; 436 437 /* 438 * This is the control buffer. It is free to use for every 439 * layer. Please put your private variables there. If you 440 * want to keep them across layers you have to do a skb_clone() 441 * first. This is owned by whoever has the skb queued ATM. 442 */ 443 char cb[48] __aligned(8); 444 445 unsigned long _skb_refdst; 446 #ifdef CONFIG_XFRM 447 struct sec_path *sp; 448 #endif 449 unsigned int len, 450 data_len; 451 __u16 mac_len, 452 hdr_len; 453 union { 454 __wsum csum; 455 struct { 456 __u16 csum_start; 457 __u16 csum_offset; 458 }; 459 }; 460 __u32 priority; 461 kmemcheck_bitfield_begin(flags1); 462 __u8 local_df:1, 463 cloned:1, 464 ip_summed:2, 465 nohdr:1, 466 nfctinfo:3; 467 __u8 pkt_type:3, 468 fclone:2, 469 ipvs_property:1, 470 peeked:1, 471 nf_trace:1; 472 kmemcheck_bitfield_end(flags1); 473 __be16 protocol; 474 475 void (*destructor)(struct sk_buff *skb); 476 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 477 struct nf_conntrack *nfct; 478 #endif 479 #ifdef CONFIG_BRIDGE_NETFILTER 480 struct nf_bridge_info *nf_bridge; 481 #endif 482 483 int skb_iif; 484 485 __u32 rxhash; 486 487 __be16 vlan_proto; 488 __u16 vlan_tci; 489 490 #ifdef CONFIG_NET_SCHED 491 __u16 tc_index; /* traffic control index */ 492 #ifdef CONFIG_NET_CLS_ACT 493 __u16 tc_verd; /* traffic control verdict */ 494 #endif 495 #endif 496 497 __u16 queue_mapping; 498 kmemcheck_bitfield_begin(flags2); 499 #ifdef CONFIG_IPV6_NDISC_NODETYPE 500 __u8 ndisc_nodetype:2; 501 #endif 502 __u8 pfmemalloc:1; 503 __u8 ooo_okay:1; 504 __u8 l4_rxhash:1; 505 __u8 wifi_acked_valid:1; 506 __u8 wifi_acked:1; 507 __u8 no_fcs:1; 508 __u8 head_frag:1; 509 /* Encapsulation protocol and NIC drivers should use 510 * this flag to indicate to each other if the skb contains 511 * encapsulated packet or not and maybe use the inner packet 512 * headers if needed 513 */ 514 __u8 encapsulation:1; 515 /* 6/8 bit hole (depending on ndisc_nodetype presence) */ 516 kmemcheck_bitfield_end(flags2); 517 518 #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL 519 union { 520 unsigned int napi_id; 521 dma_cookie_t dma_cookie; 522 }; 523 #endif 524 #ifdef CONFIG_NETWORK_SECMARK 525 __u32 secmark; 526 #endif 527 union { 528 __u32 mark; 529 __u32 dropcount; 530 __u32 reserved_tailroom; 531 }; 532 533 __be16 inner_protocol; 534 __u16 inner_transport_header; 535 __u16 inner_network_header; 536 __u16 inner_mac_header; 537 __u16 transport_header; 538 __u16 network_header; 539 __u16 mac_header; 540 /* These elements must be at the end, see alloc_skb() for details. */ 541 sk_buff_data_t tail; 542 sk_buff_data_t end; 543 unsigned char *head, 544 *data; 545 unsigned int truesize; 546 atomic_t users; 547 }; 548 549 #ifdef __KERNEL__ 550 /* 551 * Handling routines are only of interest to the kernel 552 */ 553 #include <linux/slab.h> 554 555 556 #define SKB_ALLOC_FCLONE 0x01 557 #define SKB_ALLOC_RX 0x02 558 559 /* Returns true if the skb was allocated from PFMEMALLOC reserves */ 560 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 561 { 562 return unlikely(skb->pfmemalloc); 563 } 564 565 /* 566 * skb might have a dst pointer attached, refcounted or not. 567 * _skb_refdst low order bit is set if refcount was _not_ taken 568 */ 569 #define SKB_DST_NOREF 1UL 570 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 571 572 /** 573 * skb_dst - returns skb dst_entry 574 * @skb: buffer 575 * 576 * Returns skb dst_entry, regardless of reference taken or not. 577 */ 578 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 579 { 580 /* If refdst was not refcounted, check we still are in a 581 * rcu_read_lock section 582 */ 583 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 584 !rcu_read_lock_held() && 585 !rcu_read_lock_bh_held()); 586 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 587 } 588 589 /** 590 * skb_dst_set - sets skb dst 591 * @skb: buffer 592 * @dst: dst entry 593 * 594 * Sets skb dst, assuming a reference was taken on dst and should 595 * be released by skb_dst_drop() 596 */ 597 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 598 { 599 skb->_skb_refdst = (unsigned long)dst; 600 } 601 602 void __skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst, 603 bool force); 604 605 /** 606 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference 607 * @skb: buffer 608 * @dst: dst entry 609 * 610 * Sets skb dst, assuming a reference was not taken on dst. 611 * If dst entry is cached, we do not take reference and dst_release 612 * will be avoided by refdst_drop. If dst entry is not cached, we take 613 * reference, so that last dst_release can destroy the dst immediately. 614 */ 615 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 616 { 617 __skb_dst_set_noref(skb, dst, false); 618 } 619 620 /** 621 * skb_dst_set_noref_force - sets skb dst, without taking reference 622 * @skb: buffer 623 * @dst: dst entry 624 * 625 * Sets skb dst, assuming a reference was not taken on dst. 626 * No reference is taken and no dst_release will be called. While for 627 * cached dsts deferred reclaim is a basic feature, for entries that are 628 * not cached it is caller's job to guarantee that last dst_release for 629 * provided dst happens when nobody uses it, eg. after a RCU grace period. 630 */ 631 static inline void skb_dst_set_noref_force(struct sk_buff *skb, 632 struct dst_entry *dst) 633 { 634 __skb_dst_set_noref(skb, dst, true); 635 } 636 637 /** 638 * skb_dst_is_noref - Test if skb dst isn't refcounted 639 * @skb: buffer 640 */ 641 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 642 { 643 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 644 } 645 646 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 647 { 648 return (struct rtable *)skb_dst(skb); 649 } 650 651 void kfree_skb(struct sk_buff *skb); 652 void kfree_skb_list(struct sk_buff *segs); 653 void skb_tx_error(struct sk_buff *skb); 654 void consume_skb(struct sk_buff *skb); 655 void __kfree_skb(struct sk_buff *skb); 656 extern struct kmem_cache *skbuff_head_cache; 657 658 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 659 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 660 bool *fragstolen, int *delta_truesize); 661 662 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, 663 int node); 664 struct sk_buff *build_skb(void *data, unsigned int frag_size); 665 static inline struct sk_buff *alloc_skb(unsigned int size, 666 gfp_t priority) 667 { 668 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 669 } 670 671 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 672 gfp_t priority) 673 { 674 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 675 } 676 677 struct sk_buff *__alloc_skb_head(gfp_t priority, int node); 678 static inline struct sk_buff *alloc_skb_head(gfp_t priority) 679 { 680 return __alloc_skb_head(priority, -1); 681 } 682 683 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 684 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 685 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority); 686 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority); 687 struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask); 688 689 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask); 690 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 691 unsigned int headroom); 692 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, 693 int newtailroom, gfp_t priority); 694 int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, 695 int len); 696 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); 697 int skb_pad(struct sk_buff *skb, int pad); 698 #define dev_kfree_skb(a) consume_skb(a) 699 700 int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 701 int getfrag(void *from, char *to, int offset, 702 int len, int odd, struct sk_buff *skb), 703 void *from, int length); 704 705 struct skb_seq_state { 706 __u32 lower_offset; 707 __u32 upper_offset; 708 __u32 frag_idx; 709 __u32 stepped_offset; 710 struct sk_buff *root_skb; 711 struct sk_buff *cur_skb; 712 __u8 *frag_data; 713 }; 714 715 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 716 unsigned int to, struct skb_seq_state *st); 717 unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 718 struct skb_seq_state *st); 719 void skb_abort_seq_read(struct skb_seq_state *st); 720 721 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 722 unsigned int to, struct ts_config *config, 723 struct ts_state *state); 724 725 /* 726 * Packet hash types specify the type of hash in skb_set_hash. 727 * 728 * Hash types refer to the protocol layer addresses which are used to 729 * construct a packet's hash. The hashes are used to differentiate or identify 730 * flows of the protocol layer for the hash type. Hash types are either 731 * layer-2 (L2), layer-3 (L3), or layer-4 (L4). 732 * 733 * Properties of hashes: 734 * 735 * 1) Two packets in different flows have different hash values 736 * 2) Two packets in the same flow should have the same hash value 737 * 738 * A hash at a higher layer is considered to be more specific. A driver should 739 * set the most specific hash possible. 740 * 741 * A driver cannot indicate a more specific hash than the layer at which a hash 742 * was computed. For instance an L3 hash cannot be set as an L4 hash. 743 * 744 * A driver may indicate a hash level which is less specific than the 745 * actual layer the hash was computed on. For instance, a hash computed 746 * at L4 may be considered an L3 hash. This should only be done if the 747 * driver can't unambiguously determine that the HW computed the hash at 748 * the higher layer. Note that the "should" in the second property above 749 * permits this. 750 */ 751 enum pkt_hash_types { 752 PKT_HASH_TYPE_NONE, /* Undefined type */ 753 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */ 754 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */ 755 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */ 756 }; 757 758 static inline void 759 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) 760 { 761 skb->l4_rxhash = (type == PKT_HASH_TYPE_L4); 762 skb->rxhash = hash; 763 } 764 765 void __skb_get_hash(struct sk_buff *skb); 766 static inline __u32 skb_get_hash(struct sk_buff *skb) 767 { 768 if (!skb->l4_rxhash) 769 __skb_get_hash(skb); 770 771 return skb->rxhash; 772 } 773 774 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) 775 { 776 return skb->rxhash; 777 } 778 779 static inline void skb_clear_hash(struct sk_buff *skb) 780 { 781 skb->rxhash = 0; 782 skb->l4_rxhash = 0; 783 } 784 785 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) 786 { 787 if (!skb->l4_rxhash) 788 skb_clear_hash(skb); 789 } 790 791 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) 792 { 793 to->rxhash = from->rxhash; 794 to->l4_rxhash = from->l4_rxhash; 795 }; 796 797 #ifdef NET_SKBUFF_DATA_USES_OFFSET 798 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 799 { 800 return skb->head + skb->end; 801 } 802 803 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 804 { 805 return skb->end; 806 } 807 #else 808 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 809 { 810 return skb->end; 811 } 812 813 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 814 { 815 return skb->end - skb->head; 816 } 817 #endif 818 819 /* Internal */ 820 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 821 822 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 823 { 824 return &skb_shinfo(skb)->hwtstamps; 825 } 826 827 /** 828 * skb_queue_empty - check if a queue is empty 829 * @list: queue head 830 * 831 * Returns true if the queue is empty, false otherwise. 832 */ 833 static inline int skb_queue_empty(const struct sk_buff_head *list) 834 { 835 return list->next == (const struct sk_buff *) list; 836 } 837 838 /** 839 * skb_queue_is_last - check if skb is the last entry in the queue 840 * @list: queue head 841 * @skb: buffer 842 * 843 * Returns true if @skb is the last buffer on the list. 844 */ 845 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 846 const struct sk_buff *skb) 847 { 848 return skb->next == (const struct sk_buff *) list; 849 } 850 851 /** 852 * skb_queue_is_first - check if skb is the first entry in the queue 853 * @list: queue head 854 * @skb: buffer 855 * 856 * Returns true if @skb is the first buffer on the list. 857 */ 858 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 859 const struct sk_buff *skb) 860 { 861 return skb->prev == (const struct sk_buff *) list; 862 } 863 864 /** 865 * skb_queue_next - return the next packet in the queue 866 * @list: queue head 867 * @skb: current buffer 868 * 869 * Return the next packet in @list after @skb. It is only valid to 870 * call this if skb_queue_is_last() evaluates to false. 871 */ 872 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 873 const struct sk_buff *skb) 874 { 875 /* This BUG_ON may seem severe, but if we just return then we 876 * are going to dereference garbage. 877 */ 878 BUG_ON(skb_queue_is_last(list, skb)); 879 return skb->next; 880 } 881 882 /** 883 * skb_queue_prev - return the prev packet in the queue 884 * @list: queue head 885 * @skb: current buffer 886 * 887 * Return the prev packet in @list before @skb. It is only valid to 888 * call this if skb_queue_is_first() evaluates to false. 889 */ 890 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 891 const struct sk_buff *skb) 892 { 893 /* This BUG_ON may seem severe, but if we just return then we 894 * are going to dereference garbage. 895 */ 896 BUG_ON(skb_queue_is_first(list, skb)); 897 return skb->prev; 898 } 899 900 /** 901 * skb_get - reference buffer 902 * @skb: buffer to reference 903 * 904 * Makes another reference to a socket buffer and returns a pointer 905 * to the buffer. 906 */ 907 static inline struct sk_buff *skb_get(struct sk_buff *skb) 908 { 909 atomic_inc(&skb->users); 910 return skb; 911 } 912 913 /* 914 * If users == 1, we are the only owner and are can avoid redundant 915 * atomic change. 916 */ 917 918 /** 919 * skb_cloned - is the buffer a clone 920 * @skb: buffer to check 921 * 922 * Returns true if the buffer was generated with skb_clone() and is 923 * one of multiple shared copies of the buffer. Cloned buffers are 924 * shared data so must not be written to under normal circumstances. 925 */ 926 static inline int skb_cloned(const struct sk_buff *skb) 927 { 928 return skb->cloned && 929 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 930 } 931 932 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 933 { 934 might_sleep_if(pri & __GFP_WAIT); 935 936 if (skb_cloned(skb)) 937 return pskb_expand_head(skb, 0, 0, pri); 938 939 return 0; 940 } 941 942 /** 943 * skb_header_cloned - is the header a clone 944 * @skb: buffer to check 945 * 946 * Returns true if modifying the header part of the buffer requires 947 * the data to be copied. 948 */ 949 static inline int skb_header_cloned(const struct sk_buff *skb) 950 { 951 int dataref; 952 953 if (!skb->cloned) 954 return 0; 955 956 dataref = atomic_read(&skb_shinfo(skb)->dataref); 957 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 958 return dataref != 1; 959 } 960 961 /** 962 * skb_header_release - release reference to header 963 * @skb: buffer to operate on 964 * 965 * Drop a reference to the header part of the buffer. This is done 966 * by acquiring a payload reference. You must not read from the header 967 * part of skb->data after this. 968 */ 969 static inline void skb_header_release(struct sk_buff *skb) 970 { 971 BUG_ON(skb->nohdr); 972 skb->nohdr = 1; 973 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); 974 } 975 976 /** 977 * skb_shared - is the buffer shared 978 * @skb: buffer to check 979 * 980 * Returns true if more than one person has a reference to this 981 * buffer. 982 */ 983 static inline int skb_shared(const struct sk_buff *skb) 984 { 985 return atomic_read(&skb->users) != 1; 986 } 987 988 /** 989 * skb_share_check - check if buffer is shared and if so clone it 990 * @skb: buffer to check 991 * @pri: priority for memory allocation 992 * 993 * If the buffer is shared the buffer is cloned and the old copy 994 * drops a reference. A new clone with a single reference is returned. 995 * If the buffer is not shared the original buffer is returned. When 996 * being called from interrupt status or with spinlocks held pri must 997 * be GFP_ATOMIC. 998 * 999 * NULL is returned on a memory allocation failure. 1000 */ 1001 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 1002 { 1003 might_sleep_if(pri & __GFP_WAIT); 1004 if (skb_shared(skb)) { 1005 struct sk_buff *nskb = skb_clone(skb, pri); 1006 1007 if (likely(nskb)) 1008 consume_skb(skb); 1009 else 1010 kfree_skb(skb); 1011 skb = nskb; 1012 } 1013 return skb; 1014 } 1015 1016 /* 1017 * Copy shared buffers into a new sk_buff. We effectively do COW on 1018 * packets to handle cases where we have a local reader and forward 1019 * and a couple of other messy ones. The normal one is tcpdumping 1020 * a packet thats being forwarded. 1021 */ 1022 1023 /** 1024 * skb_unshare - make a copy of a shared buffer 1025 * @skb: buffer to check 1026 * @pri: priority for memory allocation 1027 * 1028 * If the socket buffer is a clone then this function creates a new 1029 * copy of the data, drops a reference count on the old copy and returns 1030 * the new copy with the reference count at 1. If the buffer is not a clone 1031 * the original buffer is returned. When called with a spinlock held or 1032 * from interrupt state @pri must be %GFP_ATOMIC 1033 * 1034 * %NULL is returned on a memory allocation failure. 1035 */ 1036 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 1037 gfp_t pri) 1038 { 1039 might_sleep_if(pri & __GFP_WAIT); 1040 if (skb_cloned(skb)) { 1041 struct sk_buff *nskb = skb_copy(skb, pri); 1042 kfree_skb(skb); /* Free our shared copy */ 1043 skb = nskb; 1044 } 1045 return skb; 1046 } 1047 1048 /** 1049 * skb_peek - peek at the head of an &sk_buff_head 1050 * @list_: list to peek at 1051 * 1052 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1053 * be careful with this one. A peek leaves the buffer on the 1054 * list and someone else may run off with it. You must hold 1055 * the appropriate locks or have a private queue to do this. 1056 * 1057 * Returns %NULL for an empty list or a pointer to the head element. 1058 * The reference count is not incremented and the reference is therefore 1059 * volatile. Use with caution. 1060 */ 1061 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 1062 { 1063 struct sk_buff *skb = list_->next; 1064 1065 if (skb == (struct sk_buff *)list_) 1066 skb = NULL; 1067 return skb; 1068 } 1069 1070 /** 1071 * skb_peek_next - peek skb following the given one from a queue 1072 * @skb: skb to start from 1073 * @list_: list to peek at 1074 * 1075 * Returns %NULL when the end of the list is met or a pointer to the 1076 * next element. The reference count is not incremented and the 1077 * reference is therefore volatile. Use with caution. 1078 */ 1079 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 1080 const struct sk_buff_head *list_) 1081 { 1082 struct sk_buff *next = skb->next; 1083 1084 if (next == (struct sk_buff *)list_) 1085 next = NULL; 1086 return next; 1087 } 1088 1089 /** 1090 * skb_peek_tail - peek at the tail of an &sk_buff_head 1091 * @list_: list to peek at 1092 * 1093 * Peek an &sk_buff. Unlike most other operations you _MUST_ 1094 * be careful with this one. A peek leaves the buffer on the 1095 * list and someone else may run off with it. You must hold 1096 * the appropriate locks or have a private queue to do this. 1097 * 1098 * Returns %NULL for an empty list or a pointer to the tail element. 1099 * The reference count is not incremented and the reference is therefore 1100 * volatile. Use with caution. 1101 */ 1102 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 1103 { 1104 struct sk_buff *skb = list_->prev; 1105 1106 if (skb == (struct sk_buff *)list_) 1107 skb = NULL; 1108 return skb; 1109 1110 } 1111 1112 /** 1113 * skb_queue_len - get queue length 1114 * @list_: list to measure 1115 * 1116 * Return the length of an &sk_buff queue. 1117 */ 1118 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 1119 { 1120 return list_->qlen; 1121 } 1122 1123 /** 1124 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 1125 * @list: queue to initialize 1126 * 1127 * This initializes only the list and queue length aspects of 1128 * an sk_buff_head object. This allows to initialize the list 1129 * aspects of an sk_buff_head without reinitializing things like 1130 * the spinlock. It can also be used for on-stack sk_buff_head 1131 * objects where the spinlock is known to not be used. 1132 */ 1133 static inline void __skb_queue_head_init(struct sk_buff_head *list) 1134 { 1135 list->prev = list->next = (struct sk_buff *)list; 1136 list->qlen = 0; 1137 } 1138 1139 /* 1140 * This function creates a split out lock class for each invocation; 1141 * this is needed for now since a whole lot of users of the skb-queue 1142 * infrastructure in drivers have different locking usage (in hardirq) 1143 * than the networking core (in softirq only). In the long run either the 1144 * network layer or drivers should need annotation to consolidate the 1145 * main types of usage into 3 classes. 1146 */ 1147 static inline void skb_queue_head_init(struct sk_buff_head *list) 1148 { 1149 spin_lock_init(&list->lock); 1150 __skb_queue_head_init(list); 1151 } 1152 1153 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 1154 struct lock_class_key *class) 1155 { 1156 skb_queue_head_init(list); 1157 lockdep_set_class(&list->lock, class); 1158 } 1159 1160 /* 1161 * Insert an sk_buff on a list. 1162 * 1163 * The "__skb_xxxx()" functions are the non-atomic ones that 1164 * can only be called with interrupts disabled. 1165 */ 1166 void skb_insert(struct sk_buff *old, struct sk_buff *newsk, 1167 struct sk_buff_head *list); 1168 static inline void __skb_insert(struct sk_buff *newsk, 1169 struct sk_buff *prev, struct sk_buff *next, 1170 struct sk_buff_head *list) 1171 { 1172 newsk->next = next; 1173 newsk->prev = prev; 1174 next->prev = prev->next = newsk; 1175 list->qlen++; 1176 } 1177 1178 static inline void __skb_queue_splice(const struct sk_buff_head *list, 1179 struct sk_buff *prev, 1180 struct sk_buff *next) 1181 { 1182 struct sk_buff *first = list->next; 1183 struct sk_buff *last = list->prev; 1184 1185 first->prev = prev; 1186 prev->next = first; 1187 1188 last->next = next; 1189 next->prev = last; 1190 } 1191 1192 /** 1193 * skb_queue_splice - join two skb lists, this is designed for stacks 1194 * @list: the new list to add 1195 * @head: the place to add it in the first list 1196 */ 1197 static inline void skb_queue_splice(const struct sk_buff_head *list, 1198 struct sk_buff_head *head) 1199 { 1200 if (!skb_queue_empty(list)) { 1201 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1202 head->qlen += list->qlen; 1203 } 1204 } 1205 1206 /** 1207 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 1208 * @list: the new list to add 1209 * @head: the place to add it in the first list 1210 * 1211 * The list at @list is reinitialised 1212 */ 1213 static inline void skb_queue_splice_init(struct sk_buff_head *list, 1214 struct sk_buff_head *head) 1215 { 1216 if (!skb_queue_empty(list)) { 1217 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1218 head->qlen += list->qlen; 1219 __skb_queue_head_init(list); 1220 } 1221 } 1222 1223 /** 1224 * skb_queue_splice_tail - join two skb lists, each list being a queue 1225 * @list: the new list to add 1226 * @head: the place to add it in the first list 1227 */ 1228 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 1229 struct sk_buff_head *head) 1230 { 1231 if (!skb_queue_empty(list)) { 1232 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1233 head->qlen += list->qlen; 1234 } 1235 } 1236 1237 /** 1238 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 1239 * @list: the new list to add 1240 * @head: the place to add it in the first list 1241 * 1242 * Each of the lists is a queue. 1243 * The list at @list is reinitialised 1244 */ 1245 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 1246 struct sk_buff_head *head) 1247 { 1248 if (!skb_queue_empty(list)) { 1249 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1250 head->qlen += list->qlen; 1251 __skb_queue_head_init(list); 1252 } 1253 } 1254 1255 /** 1256 * __skb_queue_after - queue a buffer at the list head 1257 * @list: list to use 1258 * @prev: place after this buffer 1259 * @newsk: buffer to queue 1260 * 1261 * Queue a buffer int the middle of a list. This function takes no locks 1262 * and you must therefore hold required locks before calling it. 1263 * 1264 * A buffer cannot be placed on two lists at the same time. 1265 */ 1266 static inline void __skb_queue_after(struct sk_buff_head *list, 1267 struct sk_buff *prev, 1268 struct sk_buff *newsk) 1269 { 1270 __skb_insert(newsk, prev, prev->next, list); 1271 } 1272 1273 void skb_append(struct sk_buff *old, struct sk_buff *newsk, 1274 struct sk_buff_head *list); 1275 1276 static inline void __skb_queue_before(struct sk_buff_head *list, 1277 struct sk_buff *next, 1278 struct sk_buff *newsk) 1279 { 1280 __skb_insert(newsk, next->prev, next, list); 1281 } 1282 1283 /** 1284 * __skb_queue_head - queue a buffer at the list head 1285 * @list: list to use 1286 * @newsk: buffer to queue 1287 * 1288 * Queue a buffer at the start of a list. This function takes no locks 1289 * and you must therefore hold required locks before calling it. 1290 * 1291 * A buffer cannot be placed on two lists at the same time. 1292 */ 1293 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 1294 static inline void __skb_queue_head(struct sk_buff_head *list, 1295 struct sk_buff *newsk) 1296 { 1297 __skb_queue_after(list, (struct sk_buff *)list, newsk); 1298 } 1299 1300 /** 1301 * __skb_queue_tail - queue a buffer at the list tail 1302 * @list: list to use 1303 * @newsk: buffer to queue 1304 * 1305 * Queue a buffer at the end of a list. This function takes no locks 1306 * and you must therefore hold required locks before calling it. 1307 * 1308 * A buffer cannot be placed on two lists at the same time. 1309 */ 1310 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 1311 static inline void __skb_queue_tail(struct sk_buff_head *list, 1312 struct sk_buff *newsk) 1313 { 1314 __skb_queue_before(list, (struct sk_buff *)list, newsk); 1315 } 1316 1317 /* 1318 * remove sk_buff from list. _Must_ be called atomically, and with 1319 * the list known.. 1320 */ 1321 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 1322 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 1323 { 1324 struct sk_buff *next, *prev; 1325 1326 list->qlen--; 1327 next = skb->next; 1328 prev = skb->prev; 1329 skb->next = skb->prev = NULL; 1330 next->prev = prev; 1331 prev->next = next; 1332 } 1333 1334 /** 1335 * __skb_dequeue - remove from the head of the queue 1336 * @list: list to dequeue from 1337 * 1338 * Remove the head of the list. This function does not take any locks 1339 * so must be used with appropriate locks held only. The head item is 1340 * returned or %NULL if the list is empty. 1341 */ 1342 struct sk_buff *skb_dequeue(struct sk_buff_head *list); 1343 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 1344 { 1345 struct sk_buff *skb = skb_peek(list); 1346 if (skb) 1347 __skb_unlink(skb, list); 1348 return skb; 1349 } 1350 1351 /** 1352 * __skb_dequeue_tail - remove from the tail of the queue 1353 * @list: list to dequeue from 1354 * 1355 * Remove the tail of the list. This function does not take any locks 1356 * so must be used with appropriate locks held only. The tail item is 1357 * returned or %NULL if the list is empty. 1358 */ 1359 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 1360 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 1361 { 1362 struct sk_buff *skb = skb_peek_tail(list); 1363 if (skb) 1364 __skb_unlink(skb, list); 1365 return skb; 1366 } 1367 1368 1369 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 1370 { 1371 return skb->data_len; 1372 } 1373 1374 static inline unsigned int skb_headlen(const struct sk_buff *skb) 1375 { 1376 return skb->len - skb->data_len; 1377 } 1378 1379 static inline int skb_pagelen(const struct sk_buff *skb) 1380 { 1381 int i, len = 0; 1382 1383 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) 1384 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 1385 return len + skb_headlen(skb); 1386 } 1387 1388 /** 1389 * __skb_fill_page_desc - initialise a paged fragment in an skb 1390 * @skb: buffer containing fragment to be initialised 1391 * @i: paged fragment index to initialise 1392 * @page: the page to use for this fragment 1393 * @off: the offset to the data with @page 1394 * @size: the length of the data 1395 * 1396 * Initialises the @i'th fragment of @skb to point to &size bytes at 1397 * offset @off within @page. 1398 * 1399 * Does not take any additional reference on the fragment. 1400 */ 1401 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 1402 struct page *page, int off, int size) 1403 { 1404 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 1405 1406 /* 1407 * Propagate page->pfmemalloc to the skb if we can. The problem is 1408 * that not all callers have unique ownership of the page. If 1409 * pfmemalloc is set, we check the mapping as a mapping implies 1410 * page->index is set (index and pfmemalloc share space). 1411 * If it's a valid mapping, we cannot use page->pfmemalloc but we 1412 * do not lose pfmemalloc information as the pages would not be 1413 * allocated using __GFP_MEMALLOC. 1414 */ 1415 frag->page.p = page; 1416 frag->page_offset = off; 1417 skb_frag_size_set(frag, size); 1418 1419 page = compound_head(page); 1420 if (page->pfmemalloc && !page->mapping) 1421 skb->pfmemalloc = true; 1422 } 1423 1424 /** 1425 * skb_fill_page_desc - initialise a paged fragment in an skb 1426 * @skb: buffer containing fragment to be initialised 1427 * @i: paged fragment index to initialise 1428 * @page: the page to use for this fragment 1429 * @off: the offset to the data with @page 1430 * @size: the length of the data 1431 * 1432 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 1433 * @skb to point to @size bytes at offset @off within @page. In 1434 * addition updates @skb such that @i is the last fragment. 1435 * 1436 * Does not take any additional reference on the fragment. 1437 */ 1438 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 1439 struct page *page, int off, int size) 1440 { 1441 __skb_fill_page_desc(skb, i, page, off, size); 1442 skb_shinfo(skb)->nr_frags = i + 1; 1443 } 1444 1445 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, 1446 int size, unsigned int truesize); 1447 1448 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, 1449 unsigned int truesize); 1450 1451 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) 1452 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) 1453 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 1454 1455 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1456 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1457 { 1458 return skb->head + skb->tail; 1459 } 1460 1461 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1462 { 1463 skb->tail = skb->data - skb->head; 1464 } 1465 1466 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1467 { 1468 skb_reset_tail_pointer(skb); 1469 skb->tail += offset; 1470 } 1471 1472 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1473 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1474 { 1475 return skb->tail; 1476 } 1477 1478 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1479 { 1480 skb->tail = skb->data; 1481 } 1482 1483 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1484 { 1485 skb->tail = skb->data + offset; 1486 } 1487 1488 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1489 1490 /* 1491 * Add data to an sk_buff 1492 */ 1493 unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len); 1494 unsigned char *skb_put(struct sk_buff *skb, unsigned int len); 1495 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) 1496 { 1497 unsigned char *tmp = skb_tail_pointer(skb); 1498 SKB_LINEAR_ASSERT(skb); 1499 skb->tail += len; 1500 skb->len += len; 1501 return tmp; 1502 } 1503 1504 unsigned char *skb_push(struct sk_buff *skb, unsigned int len); 1505 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) 1506 { 1507 skb->data -= len; 1508 skb->len += len; 1509 return skb->data; 1510 } 1511 1512 unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); 1513 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) 1514 { 1515 skb->len -= len; 1516 BUG_ON(skb->len < skb->data_len); 1517 return skb->data += len; 1518 } 1519 1520 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) 1521 { 1522 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 1523 } 1524 1525 unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); 1526 1527 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) 1528 { 1529 if (len > skb_headlen(skb) && 1530 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 1531 return NULL; 1532 skb->len -= len; 1533 return skb->data += len; 1534 } 1535 1536 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) 1537 { 1538 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 1539 } 1540 1541 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) 1542 { 1543 if (likely(len <= skb_headlen(skb))) 1544 return 1; 1545 if (unlikely(len > skb->len)) 1546 return 0; 1547 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 1548 } 1549 1550 /** 1551 * skb_headroom - bytes at buffer head 1552 * @skb: buffer to check 1553 * 1554 * Return the number of bytes of free space at the head of an &sk_buff. 1555 */ 1556 static inline unsigned int skb_headroom(const struct sk_buff *skb) 1557 { 1558 return skb->data - skb->head; 1559 } 1560 1561 /** 1562 * skb_tailroom - bytes at buffer end 1563 * @skb: buffer to check 1564 * 1565 * Return the number of bytes of free space at the tail of an sk_buff 1566 */ 1567 static inline int skb_tailroom(const struct sk_buff *skb) 1568 { 1569 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 1570 } 1571 1572 /** 1573 * skb_availroom - bytes at buffer end 1574 * @skb: buffer to check 1575 * 1576 * Return the number of bytes of free space at the tail of an sk_buff 1577 * allocated by sk_stream_alloc() 1578 */ 1579 static inline int skb_availroom(const struct sk_buff *skb) 1580 { 1581 if (skb_is_nonlinear(skb)) 1582 return 0; 1583 1584 return skb->end - skb->tail - skb->reserved_tailroom; 1585 } 1586 1587 /** 1588 * skb_reserve - adjust headroom 1589 * @skb: buffer to alter 1590 * @len: bytes to move 1591 * 1592 * Increase the headroom of an empty &sk_buff by reducing the tail 1593 * room. This is only allowed for an empty buffer. 1594 */ 1595 static inline void skb_reserve(struct sk_buff *skb, int len) 1596 { 1597 skb->data += len; 1598 skb->tail += len; 1599 } 1600 1601 static inline void skb_reset_inner_headers(struct sk_buff *skb) 1602 { 1603 skb->inner_mac_header = skb->mac_header; 1604 skb->inner_network_header = skb->network_header; 1605 skb->inner_transport_header = skb->transport_header; 1606 } 1607 1608 static inline void skb_reset_mac_len(struct sk_buff *skb) 1609 { 1610 skb->mac_len = skb->network_header - skb->mac_header; 1611 } 1612 1613 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 1614 *skb) 1615 { 1616 return skb->head + skb->inner_transport_header; 1617 } 1618 1619 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 1620 { 1621 skb->inner_transport_header = skb->data - skb->head; 1622 } 1623 1624 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 1625 const int offset) 1626 { 1627 skb_reset_inner_transport_header(skb); 1628 skb->inner_transport_header += offset; 1629 } 1630 1631 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 1632 { 1633 return skb->head + skb->inner_network_header; 1634 } 1635 1636 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 1637 { 1638 skb->inner_network_header = skb->data - skb->head; 1639 } 1640 1641 static inline void skb_set_inner_network_header(struct sk_buff *skb, 1642 const int offset) 1643 { 1644 skb_reset_inner_network_header(skb); 1645 skb->inner_network_header += offset; 1646 } 1647 1648 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 1649 { 1650 return skb->head + skb->inner_mac_header; 1651 } 1652 1653 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 1654 { 1655 skb->inner_mac_header = skb->data - skb->head; 1656 } 1657 1658 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 1659 const int offset) 1660 { 1661 skb_reset_inner_mac_header(skb); 1662 skb->inner_mac_header += offset; 1663 } 1664 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 1665 { 1666 return skb->transport_header != (typeof(skb->transport_header))~0U; 1667 } 1668 1669 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1670 { 1671 return skb->head + skb->transport_header; 1672 } 1673 1674 static inline void skb_reset_transport_header(struct sk_buff *skb) 1675 { 1676 skb->transport_header = skb->data - skb->head; 1677 } 1678 1679 static inline void skb_set_transport_header(struct sk_buff *skb, 1680 const int offset) 1681 { 1682 skb_reset_transport_header(skb); 1683 skb->transport_header += offset; 1684 } 1685 1686 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 1687 { 1688 return skb->head + skb->network_header; 1689 } 1690 1691 static inline void skb_reset_network_header(struct sk_buff *skb) 1692 { 1693 skb->network_header = skb->data - skb->head; 1694 } 1695 1696 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 1697 { 1698 skb_reset_network_header(skb); 1699 skb->network_header += offset; 1700 } 1701 1702 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 1703 { 1704 return skb->head + skb->mac_header; 1705 } 1706 1707 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 1708 { 1709 return skb->mac_header != (typeof(skb->mac_header))~0U; 1710 } 1711 1712 static inline void skb_reset_mac_header(struct sk_buff *skb) 1713 { 1714 skb->mac_header = skb->data - skb->head; 1715 } 1716 1717 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 1718 { 1719 skb_reset_mac_header(skb); 1720 skb->mac_header += offset; 1721 } 1722 1723 static inline void skb_pop_mac_header(struct sk_buff *skb) 1724 { 1725 skb->mac_header = skb->network_header; 1726 } 1727 1728 static inline void skb_probe_transport_header(struct sk_buff *skb, 1729 const int offset_hint) 1730 { 1731 struct flow_keys keys; 1732 1733 if (skb_transport_header_was_set(skb)) 1734 return; 1735 else if (skb_flow_dissect(skb, &keys)) 1736 skb_set_transport_header(skb, keys.thoff); 1737 else 1738 skb_set_transport_header(skb, offset_hint); 1739 } 1740 1741 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 1742 { 1743 if (skb_mac_header_was_set(skb)) { 1744 const unsigned char *old_mac = skb_mac_header(skb); 1745 1746 skb_set_mac_header(skb, -skb->mac_len); 1747 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 1748 } 1749 } 1750 1751 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 1752 { 1753 return skb->csum_start - skb_headroom(skb); 1754 } 1755 1756 static inline int skb_transport_offset(const struct sk_buff *skb) 1757 { 1758 return skb_transport_header(skb) - skb->data; 1759 } 1760 1761 static inline u32 skb_network_header_len(const struct sk_buff *skb) 1762 { 1763 return skb->transport_header - skb->network_header; 1764 } 1765 1766 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 1767 { 1768 return skb->inner_transport_header - skb->inner_network_header; 1769 } 1770 1771 static inline int skb_network_offset(const struct sk_buff *skb) 1772 { 1773 return skb_network_header(skb) - skb->data; 1774 } 1775 1776 static inline int skb_inner_network_offset(const struct sk_buff *skb) 1777 { 1778 return skb_inner_network_header(skb) - skb->data; 1779 } 1780 1781 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 1782 { 1783 return pskb_may_pull(skb, skb_network_offset(skb) + len); 1784 } 1785 1786 /* 1787 * CPUs often take a performance hit when accessing unaligned memory 1788 * locations. The actual performance hit varies, it can be small if the 1789 * hardware handles it or large if we have to take an exception and fix it 1790 * in software. 1791 * 1792 * Since an ethernet header is 14 bytes network drivers often end up with 1793 * the IP header at an unaligned offset. The IP header can be aligned by 1794 * shifting the start of the packet by 2 bytes. Drivers should do this 1795 * with: 1796 * 1797 * skb_reserve(skb, NET_IP_ALIGN); 1798 * 1799 * The downside to this alignment of the IP header is that the DMA is now 1800 * unaligned. On some architectures the cost of an unaligned DMA is high 1801 * and this cost outweighs the gains made by aligning the IP header. 1802 * 1803 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 1804 * to be overridden. 1805 */ 1806 #ifndef NET_IP_ALIGN 1807 #define NET_IP_ALIGN 2 1808 #endif 1809 1810 /* 1811 * The networking layer reserves some headroom in skb data (via 1812 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 1813 * the header has to grow. In the default case, if the header has to grow 1814 * 32 bytes or less we avoid the reallocation. 1815 * 1816 * Unfortunately this headroom changes the DMA alignment of the resulting 1817 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 1818 * on some architectures. An architecture can override this value, 1819 * perhaps setting it to a cacheline in size (since that will maintain 1820 * cacheline alignment of the DMA). It must be a power of 2. 1821 * 1822 * Various parts of the networking layer expect at least 32 bytes of 1823 * headroom, you should not reduce this. 1824 * 1825 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 1826 * to reduce average number of cache lines per packet. 1827 * get_rps_cpus() for example only access one 64 bytes aligned block : 1828 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 1829 */ 1830 #ifndef NET_SKB_PAD 1831 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 1832 #endif 1833 1834 int ___pskb_trim(struct sk_buff *skb, unsigned int len); 1835 1836 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 1837 { 1838 if (unlikely(skb_is_nonlinear(skb))) { 1839 WARN_ON(1); 1840 return; 1841 } 1842 skb->len = len; 1843 skb_set_tail_pointer(skb, len); 1844 } 1845 1846 void skb_trim(struct sk_buff *skb, unsigned int len); 1847 1848 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 1849 { 1850 if (skb->data_len) 1851 return ___pskb_trim(skb, len); 1852 __skb_trim(skb, len); 1853 return 0; 1854 } 1855 1856 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 1857 { 1858 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 1859 } 1860 1861 /** 1862 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 1863 * @skb: buffer to alter 1864 * @len: new length 1865 * 1866 * This is identical to pskb_trim except that the caller knows that 1867 * the skb is not cloned so we should never get an error due to out- 1868 * of-memory. 1869 */ 1870 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 1871 { 1872 int err = pskb_trim(skb, len); 1873 BUG_ON(err); 1874 } 1875 1876 /** 1877 * skb_orphan - orphan a buffer 1878 * @skb: buffer to orphan 1879 * 1880 * If a buffer currently has an owner then we call the owner's 1881 * destructor function and make the @skb unowned. The buffer continues 1882 * to exist but is no longer charged to its former owner. 1883 */ 1884 static inline void skb_orphan(struct sk_buff *skb) 1885 { 1886 if (skb->destructor) { 1887 skb->destructor(skb); 1888 skb->destructor = NULL; 1889 skb->sk = NULL; 1890 } else { 1891 BUG_ON(skb->sk); 1892 } 1893 } 1894 1895 /** 1896 * skb_orphan_frags - orphan the frags contained in a buffer 1897 * @skb: buffer to orphan frags from 1898 * @gfp_mask: allocation mask for replacement pages 1899 * 1900 * For each frag in the SKB which needs a destructor (i.e. has an 1901 * owner) create a copy of that frag and release the original 1902 * page by calling the destructor. 1903 */ 1904 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 1905 { 1906 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))) 1907 return 0; 1908 return skb_copy_ubufs(skb, gfp_mask); 1909 } 1910 1911 /** 1912 * __skb_queue_purge - empty a list 1913 * @list: list to empty 1914 * 1915 * Delete all buffers on an &sk_buff list. Each buffer is removed from 1916 * the list and one reference dropped. This function does not take the 1917 * list lock and the caller must hold the relevant locks to use it. 1918 */ 1919 void skb_queue_purge(struct sk_buff_head *list); 1920 static inline void __skb_queue_purge(struct sk_buff_head *list) 1921 { 1922 struct sk_buff *skb; 1923 while ((skb = __skb_dequeue(list)) != NULL) 1924 kfree_skb(skb); 1925 } 1926 1927 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768) 1928 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER) 1929 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE 1930 1931 void *netdev_alloc_frag(unsigned int fragsz); 1932 1933 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, 1934 gfp_t gfp_mask); 1935 1936 /** 1937 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 1938 * @dev: network device to receive on 1939 * @length: length to allocate 1940 * 1941 * Allocate a new &sk_buff and assign it a usage count of one. The 1942 * buffer has unspecified headroom built in. Users should allocate 1943 * the headroom they think they need without accounting for the 1944 * built in space. The built in space is used for optimisations. 1945 * 1946 * %NULL is returned if there is no free memory. Although this function 1947 * allocates memory it can be called from an interrupt. 1948 */ 1949 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 1950 unsigned int length) 1951 { 1952 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 1953 } 1954 1955 /* legacy helper around __netdev_alloc_skb() */ 1956 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 1957 gfp_t gfp_mask) 1958 { 1959 return __netdev_alloc_skb(NULL, length, gfp_mask); 1960 } 1961 1962 /* legacy helper around netdev_alloc_skb() */ 1963 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 1964 { 1965 return netdev_alloc_skb(NULL, length); 1966 } 1967 1968 1969 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 1970 unsigned int length, gfp_t gfp) 1971 { 1972 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 1973 1974 if (NET_IP_ALIGN && skb) 1975 skb_reserve(skb, NET_IP_ALIGN); 1976 return skb; 1977 } 1978 1979 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 1980 unsigned int length) 1981 { 1982 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 1983 } 1984 1985 /** 1986 * __skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data 1987 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX 1988 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used 1989 * @order: size of the allocation 1990 * 1991 * Allocate a new page. 1992 * 1993 * %NULL is returned if there is no free memory. 1994 */ 1995 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask, 1996 struct sk_buff *skb, 1997 unsigned int order) 1998 { 1999 struct page *page; 2000 2001 gfp_mask |= __GFP_COLD; 2002 2003 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2004 gfp_mask |= __GFP_MEMALLOC; 2005 2006 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 2007 if (skb && page && page->pfmemalloc) 2008 skb->pfmemalloc = true; 2009 2010 return page; 2011 } 2012 2013 /** 2014 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data 2015 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX 2016 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used 2017 * 2018 * Allocate a new page. 2019 * 2020 * %NULL is returned if there is no free memory. 2021 */ 2022 static inline struct page *__skb_alloc_page(gfp_t gfp_mask, 2023 struct sk_buff *skb) 2024 { 2025 return __skb_alloc_pages(gfp_mask, skb, 0); 2026 } 2027 2028 /** 2029 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 2030 * @page: The page that was allocated from skb_alloc_page 2031 * @skb: The skb that may need pfmemalloc set 2032 */ 2033 static inline void skb_propagate_pfmemalloc(struct page *page, 2034 struct sk_buff *skb) 2035 { 2036 if (page && page->pfmemalloc) 2037 skb->pfmemalloc = true; 2038 } 2039 2040 /** 2041 * skb_frag_page - retrieve the page refered to by a paged fragment 2042 * @frag: the paged fragment 2043 * 2044 * Returns the &struct page associated with @frag. 2045 */ 2046 static inline struct page *skb_frag_page(const skb_frag_t *frag) 2047 { 2048 return frag->page.p; 2049 } 2050 2051 /** 2052 * __skb_frag_ref - take an addition reference on a paged fragment. 2053 * @frag: the paged fragment 2054 * 2055 * Takes an additional reference on the paged fragment @frag. 2056 */ 2057 static inline void __skb_frag_ref(skb_frag_t *frag) 2058 { 2059 get_page(skb_frag_page(frag)); 2060 } 2061 2062 /** 2063 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 2064 * @skb: the buffer 2065 * @f: the fragment offset. 2066 * 2067 * Takes an additional reference on the @f'th paged fragment of @skb. 2068 */ 2069 static inline void skb_frag_ref(struct sk_buff *skb, int f) 2070 { 2071 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 2072 } 2073 2074 /** 2075 * __skb_frag_unref - release a reference on a paged fragment. 2076 * @frag: the paged fragment 2077 * 2078 * Releases a reference on the paged fragment @frag. 2079 */ 2080 static inline void __skb_frag_unref(skb_frag_t *frag) 2081 { 2082 put_page(skb_frag_page(frag)); 2083 } 2084 2085 /** 2086 * skb_frag_unref - release a reference on a paged fragment of an skb. 2087 * @skb: the buffer 2088 * @f: the fragment offset 2089 * 2090 * Releases a reference on the @f'th paged fragment of @skb. 2091 */ 2092 static inline void skb_frag_unref(struct sk_buff *skb, int f) 2093 { 2094 __skb_frag_unref(&skb_shinfo(skb)->frags[f]); 2095 } 2096 2097 /** 2098 * skb_frag_address - gets the address of the data contained in a paged fragment 2099 * @frag: the paged fragment buffer 2100 * 2101 * Returns the address of the data within @frag. The page must already 2102 * be mapped. 2103 */ 2104 static inline void *skb_frag_address(const skb_frag_t *frag) 2105 { 2106 return page_address(skb_frag_page(frag)) + frag->page_offset; 2107 } 2108 2109 /** 2110 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 2111 * @frag: the paged fragment buffer 2112 * 2113 * Returns the address of the data within @frag. Checks that the page 2114 * is mapped and returns %NULL otherwise. 2115 */ 2116 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 2117 { 2118 void *ptr = page_address(skb_frag_page(frag)); 2119 if (unlikely(!ptr)) 2120 return NULL; 2121 2122 return ptr + frag->page_offset; 2123 } 2124 2125 /** 2126 * __skb_frag_set_page - sets the page contained in a paged fragment 2127 * @frag: the paged fragment 2128 * @page: the page to set 2129 * 2130 * Sets the fragment @frag to contain @page. 2131 */ 2132 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page) 2133 { 2134 frag->page.p = page; 2135 } 2136 2137 /** 2138 * skb_frag_set_page - sets the page contained in a paged fragment of an skb 2139 * @skb: the buffer 2140 * @f: the fragment offset 2141 * @page: the page to set 2142 * 2143 * Sets the @f'th fragment of @skb to contain @page. 2144 */ 2145 static inline void skb_frag_set_page(struct sk_buff *skb, int f, 2146 struct page *page) 2147 { 2148 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page); 2149 } 2150 2151 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 2152 2153 /** 2154 * skb_frag_dma_map - maps a paged fragment via the DMA API 2155 * @dev: the device to map the fragment to 2156 * @frag: the paged fragment to map 2157 * @offset: the offset within the fragment (starting at the 2158 * fragment's own offset) 2159 * @size: the number of bytes to map 2160 * @dir: the direction of the mapping (%PCI_DMA_*) 2161 * 2162 * Maps the page associated with @frag to @device. 2163 */ 2164 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 2165 const skb_frag_t *frag, 2166 size_t offset, size_t size, 2167 enum dma_data_direction dir) 2168 { 2169 return dma_map_page(dev, skb_frag_page(frag), 2170 frag->page_offset + offset, size, dir); 2171 } 2172 2173 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 2174 gfp_t gfp_mask) 2175 { 2176 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 2177 } 2178 2179 /** 2180 * skb_clone_writable - is the header of a clone writable 2181 * @skb: buffer to check 2182 * @len: length up to which to write 2183 * 2184 * Returns true if modifying the header part of the cloned buffer 2185 * does not requires the data to be copied. 2186 */ 2187 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 2188 { 2189 return !skb_header_cloned(skb) && 2190 skb_headroom(skb) + len <= skb->hdr_len; 2191 } 2192 2193 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 2194 int cloned) 2195 { 2196 int delta = 0; 2197 2198 if (headroom > skb_headroom(skb)) 2199 delta = headroom - skb_headroom(skb); 2200 2201 if (delta || cloned) 2202 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 2203 GFP_ATOMIC); 2204 return 0; 2205 } 2206 2207 /** 2208 * skb_cow - copy header of skb when it is required 2209 * @skb: buffer to cow 2210 * @headroom: needed headroom 2211 * 2212 * If the skb passed lacks sufficient headroom or its data part 2213 * is shared, data is reallocated. If reallocation fails, an error 2214 * is returned and original skb is not changed. 2215 * 2216 * The result is skb with writable area skb->head...skb->tail 2217 * and at least @headroom of space at head. 2218 */ 2219 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 2220 { 2221 return __skb_cow(skb, headroom, skb_cloned(skb)); 2222 } 2223 2224 /** 2225 * skb_cow_head - skb_cow but only making the head writable 2226 * @skb: buffer to cow 2227 * @headroom: needed headroom 2228 * 2229 * This function is identical to skb_cow except that we replace the 2230 * skb_cloned check by skb_header_cloned. It should be used when 2231 * you only need to push on some header and do not need to modify 2232 * the data. 2233 */ 2234 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 2235 { 2236 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 2237 } 2238 2239 /** 2240 * skb_padto - pad an skbuff up to a minimal size 2241 * @skb: buffer to pad 2242 * @len: minimal length 2243 * 2244 * Pads up a buffer to ensure the trailing bytes exist and are 2245 * blanked. If the buffer already contains sufficient data it 2246 * is untouched. Otherwise it is extended. Returns zero on 2247 * success. The skb is freed on error. 2248 */ 2249 2250 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 2251 { 2252 unsigned int size = skb->len; 2253 if (likely(size >= len)) 2254 return 0; 2255 return skb_pad(skb, len - size); 2256 } 2257 2258 static inline int skb_add_data(struct sk_buff *skb, 2259 char __user *from, int copy) 2260 { 2261 const int off = skb->len; 2262 2263 if (skb->ip_summed == CHECKSUM_NONE) { 2264 int err = 0; 2265 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), 2266 copy, 0, &err); 2267 if (!err) { 2268 skb->csum = csum_block_add(skb->csum, csum, off); 2269 return 0; 2270 } 2271 } else if (!copy_from_user(skb_put(skb, copy), from, copy)) 2272 return 0; 2273 2274 __skb_trim(skb, off); 2275 return -EFAULT; 2276 } 2277 2278 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 2279 const struct page *page, int off) 2280 { 2281 if (i) { 2282 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; 2283 2284 return page == skb_frag_page(frag) && 2285 off == frag->page_offset + skb_frag_size(frag); 2286 } 2287 return false; 2288 } 2289 2290 static inline int __skb_linearize(struct sk_buff *skb) 2291 { 2292 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 2293 } 2294 2295 /** 2296 * skb_linearize - convert paged skb to linear one 2297 * @skb: buffer to linarize 2298 * 2299 * If there is no free memory -ENOMEM is returned, otherwise zero 2300 * is returned and the old skb data released. 2301 */ 2302 static inline int skb_linearize(struct sk_buff *skb) 2303 { 2304 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 2305 } 2306 2307 /** 2308 * skb_has_shared_frag - can any frag be overwritten 2309 * @skb: buffer to test 2310 * 2311 * Return true if the skb has at least one frag that might be modified 2312 * by an external entity (as in vmsplice()/sendfile()) 2313 */ 2314 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 2315 { 2316 return skb_is_nonlinear(skb) && 2317 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; 2318 } 2319 2320 /** 2321 * skb_linearize_cow - make sure skb is linear and writable 2322 * @skb: buffer to process 2323 * 2324 * If there is no free memory -ENOMEM is returned, otherwise zero 2325 * is returned and the old skb data released. 2326 */ 2327 static inline int skb_linearize_cow(struct sk_buff *skb) 2328 { 2329 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 2330 __skb_linearize(skb) : 0; 2331 } 2332 2333 /** 2334 * skb_postpull_rcsum - update checksum for received skb after pull 2335 * @skb: buffer to update 2336 * @start: start of data before pull 2337 * @len: length of data pulled 2338 * 2339 * After doing a pull on a received packet, you need to call this to 2340 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 2341 * CHECKSUM_NONE so that it can be recomputed from scratch. 2342 */ 2343 2344 static inline void skb_postpull_rcsum(struct sk_buff *skb, 2345 const void *start, unsigned int len) 2346 { 2347 if (skb->ip_summed == CHECKSUM_COMPLETE) 2348 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); 2349 } 2350 2351 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 2352 2353 /** 2354 * pskb_trim_rcsum - trim received skb and update checksum 2355 * @skb: buffer to trim 2356 * @len: new length 2357 * 2358 * This is exactly the same as pskb_trim except that it ensures the 2359 * checksum of received packets are still valid after the operation. 2360 */ 2361 2362 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 2363 { 2364 if (likely(len >= skb->len)) 2365 return 0; 2366 if (skb->ip_summed == CHECKSUM_COMPLETE) 2367 skb->ip_summed = CHECKSUM_NONE; 2368 return __pskb_trim(skb, len); 2369 } 2370 2371 #define skb_queue_walk(queue, skb) \ 2372 for (skb = (queue)->next; \ 2373 skb != (struct sk_buff *)(queue); \ 2374 skb = skb->next) 2375 2376 #define skb_queue_walk_safe(queue, skb, tmp) \ 2377 for (skb = (queue)->next, tmp = skb->next; \ 2378 skb != (struct sk_buff *)(queue); \ 2379 skb = tmp, tmp = skb->next) 2380 2381 #define skb_queue_walk_from(queue, skb) \ 2382 for (; skb != (struct sk_buff *)(queue); \ 2383 skb = skb->next) 2384 2385 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 2386 for (tmp = skb->next; \ 2387 skb != (struct sk_buff *)(queue); \ 2388 skb = tmp, tmp = skb->next) 2389 2390 #define skb_queue_reverse_walk(queue, skb) \ 2391 for (skb = (queue)->prev; \ 2392 skb != (struct sk_buff *)(queue); \ 2393 skb = skb->prev) 2394 2395 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 2396 for (skb = (queue)->prev, tmp = skb->prev; \ 2397 skb != (struct sk_buff *)(queue); \ 2398 skb = tmp, tmp = skb->prev) 2399 2400 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 2401 for (tmp = skb->prev; \ 2402 skb != (struct sk_buff *)(queue); \ 2403 skb = tmp, tmp = skb->prev) 2404 2405 static inline bool skb_has_frag_list(const struct sk_buff *skb) 2406 { 2407 return skb_shinfo(skb)->frag_list != NULL; 2408 } 2409 2410 static inline void skb_frag_list_init(struct sk_buff *skb) 2411 { 2412 skb_shinfo(skb)->frag_list = NULL; 2413 } 2414 2415 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) 2416 { 2417 frag->next = skb_shinfo(skb)->frag_list; 2418 skb_shinfo(skb)->frag_list = frag; 2419 } 2420 2421 #define skb_walk_frags(skb, iter) \ 2422 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 2423 2424 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, 2425 int *peeked, int *off, int *err); 2426 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, 2427 int *err); 2428 unsigned int datagram_poll(struct file *file, struct socket *sock, 2429 struct poll_table_struct *wait); 2430 int skb_copy_datagram_iovec(const struct sk_buff *from, int offset, 2431 struct iovec *to, int size); 2432 int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen, 2433 struct iovec *iov); 2434 int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, 2435 const struct iovec *from, int from_offset, 2436 int len); 2437 int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm, 2438 int offset, size_t count); 2439 int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset, 2440 const struct iovec *to, int to_offset, 2441 int size); 2442 void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 2443 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb); 2444 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); 2445 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); 2446 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len); 2447 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to, 2448 int len, __wsum csum); 2449 int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 2450 struct pipe_inode_info *pipe, unsigned int len, 2451 unsigned int flags); 2452 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 2453 unsigned int skb_zerocopy_headlen(const struct sk_buff *from); 2454 void skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, 2455 int len, int hlen); 2456 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); 2457 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); 2458 void skb_scrub_packet(struct sk_buff *skb, bool xnet); 2459 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb); 2460 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); 2461 2462 struct skb_checksum_ops { 2463 __wsum (*update)(const void *mem, int len, __wsum wsum); 2464 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len); 2465 }; 2466 2467 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, 2468 __wsum csum, const struct skb_checksum_ops *ops); 2469 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len, 2470 __wsum csum); 2471 2472 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, 2473 int len, void *buffer) 2474 { 2475 int hlen = skb_headlen(skb); 2476 2477 if (hlen - offset >= len) 2478 return skb->data + offset; 2479 2480 if (skb_copy_bits(skb, offset, buffer, len) < 0) 2481 return NULL; 2482 2483 return buffer; 2484 } 2485 2486 /** 2487 * skb_needs_linearize - check if we need to linearize a given skb 2488 * depending on the given device features. 2489 * @skb: socket buffer to check 2490 * @features: net device features 2491 * 2492 * Returns true if either: 2493 * 1. skb has frag_list and the device doesn't support FRAGLIST, or 2494 * 2. skb is fragmented and the device does not support SG. 2495 */ 2496 static inline bool skb_needs_linearize(struct sk_buff *skb, 2497 netdev_features_t features) 2498 { 2499 return skb_is_nonlinear(skb) && 2500 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) || 2501 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG))); 2502 } 2503 2504 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 2505 void *to, 2506 const unsigned int len) 2507 { 2508 memcpy(to, skb->data, len); 2509 } 2510 2511 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 2512 const int offset, void *to, 2513 const unsigned int len) 2514 { 2515 memcpy(to, skb->data + offset, len); 2516 } 2517 2518 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 2519 const void *from, 2520 const unsigned int len) 2521 { 2522 memcpy(skb->data, from, len); 2523 } 2524 2525 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 2526 const int offset, 2527 const void *from, 2528 const unsigned int len) 2529 { 2530 memcpy(skb->data + offset, from, len); 2531 } 2532 2533 void skb_init(void); 2534 2535 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 2536 { 2537 return skb->tstamp; 2538 } 2539 2540 /** 2541 * skb_get_timestamp - get timestamp from a skb 2542 * @skb: skb to get stamp from 2543 * @stamp: pointer to struct timeval to store stamp in 2544 * 2545 * Timestamps are stored in the skb as offsets to a base timestamp. 2546 * This function converts the offset back to a struct timeval and stores 2547 * it in stamp. 2548 */ 2549 static inline void skb_get_timestamp(const struct sk_buff *skb, 2550 struct timeval *stamp) 2551 { 2552 *stamp = ktime_to_timeval(skb->tstamp); 2553 } 2554 2555 static inline void skb_get_timestampns(const struct sk_buff *skb, 2556 struct timespec *stamp) 2557 { 2558 *stamp = ktime_to_timespec(skb->tstamp); 2559 } 2560 2561 static inline void __net_timestamp(struct sk_buff *skb) 2562 { 2563 skb->tstamp = ktime_get_real(); 2564 } 2565 2566 static inline ktime_t net_timedelta(ktime_t t) 2567 { 2568 return ktime_sub(ktime_get_real(), t); 2569 } 2570 2571 static inline ktime_t net_invalid_timestamp(void) 2572 { 2573 return ktime_set(0, 0); 2574 } 2575 2576 void skb_timestamping_init(void); 2577 2578 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 2579 2580 void skb_clone_tx_timestamp(struct sk_buff *skb); 2581 bool skb_defer_rx_timestamp(struct sk_buff *skb); 2582 2583 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 2584 2585 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 2586 { 2587 } 2588 2589 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 2590 { 2591 return false; 2592 } 2593 2594 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 2595 2596 /** 2597 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 2598 * 2599 * PHY drivers may accept clones of transmitted packets for 2600 * timestamping via their phy_driver.txtstamp method. These drivers 2601 * must call this function to return the skb back to the stack, with 2602 * or without a timestamp. 2603 * 2604 * @skb: clone of the the original outgoing packet 2605 * @hwtstamps: hardware time stamps, may be NULL if not available 2606 * 2607 */ 2608 void skb_complete_tx_timestamp(struct sk_buff *skb, 2609 struct skb_shared_hwtstamps *hwtstamps); 2610 2611 /** 2612 * skb_tstamp_tx - queue clone of skb with send time stamps 2613 * @orig_skb: the original outgoing packet 2614 * @hwtstamps: hardware time stamps, may be NULL if not available 2615 * 2616 * If the skb has a socket associated, then this function clones the 2617 * skb (thus sharing the actual data and optional structures), stores 2618 * the optional hardware time stamping information (if non NULL) or 2619 * generates a software time stamp (otherwise), then queues the clone 2620 * to the error queue of the socket. Errors are silently ignored. 2621 */ 2622 void skb_tstamp_tx(struct sk_buff *orig_skb, 2623 struct skb_shared_hwtstamps *hwtstamps); 2624 2625 static inline void sw_tx_timestamp(struct sk_buff *skb) 2626 { 2627 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && 2628 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 2629 skb_tstamp_tx(skb, NULL); 2630 } 2631 2632 /** 2633 * skb_tx_timestamp() - Driver hook for transmit timestamping 2634 * 2635 * Ethernet MAC Drivers should call this function in their hard_xmit() 2636 * function immediately before giving the sk_buff to the MAC hardware. 2637 * 2638 * Specifically, one should make absolutely sure that this function is 2639 * called before TX completion of this packet can trigger. Otherwise 2640 * the packet could potentially already be freed. 2641 * 2642 * @skb: A socket buffer. 2643 */ 2644 static inline void skb_tx_timestamp(struct sk_buff *skb) 2645 { 2646 skb_clone_tx_timestamp(skb); 2647 sw_tx_timestamp(skb); 2648 } 2649 2650 /** 2651 * skb_complete_wifi_ack - deliver skb with wifi status 2652 * 2653 * @skb: the original outgoing packet 2654 * @acked: ack status 2655 * 2656 */ 2657 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 2658 2659 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 2660 __sum16 __skb_checksum_complete(struct sk_buff *skb); 2661 2662 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 2663 { 2664 return skb->ip_summed & CHECKSUM_UNNECESSARY; 2665 } 2666 2667 /** 2668 * skb_checksum_complete - Calculate checksum of an entire packet 2669 * @skb: packet to process 2670 * 2671 * This function calculates the checksum over the entire packet plus 2672 * the value of skb->csum. The latter can be used to supply the 2673 * checksum of a pseudo header as used by TCP/UDP. It returns the 2674 * checksum. 2675 * 2676 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 2677 * this function can be used to verify that checksum on received 2678 * packets. In that case the function should return zero if the 2679 * checksum is correct. In particular, this function will return zero 2680 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 2681 * hardware has already verified the correctness of the checksum. 2682 */ 2683 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 2684 { 2685 return skb_csum_unnecessary(skb) ? 2686 0 : __skb_checksum_complete(skb); 2687 } 2688 2689 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2690 void nf_conntrack_destroy(struct nf_conntrack *nfct); 2691 static inline void nf_conntrack_put(struct nf_conntrack *nfct) 2692 { 2693 if (nfct && atomic_dec_and_test(&nfct->use)) 2694 nf_conntrack_destroy(nfct); 2695 } 2696 static inline void nf_conntrack_get(struct nf_conntrack *nfct) 2697 { 2698 if (nfct) 2699 atomic_inc(&nfct->use); 2700 } 2701 #endif 2702 #ifdef CONFIG_BRIDGE_NETFILTER 2703 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) 2704 { 2705 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) 2706 kfree(nf_bridge); 2707 } 2708 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) 2709 { 2710 if (nf_bridge) 2711 atomic_inc(&nf_bridge->use); 2712 } 2713 #endif /* CONFIG_BRIDGE_NETFILTER */ 2714 static inline void nf_reset(struct sk_buff *skb) 2715 { 2716 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2717 nf_conntrack_put(skb->nfct); 2718 skb->nfct = NULL; 2719 #endif 2720 #ifdef CONFIG_BRIDGE_NETFILTER 2721 nf_bridge_put(skb->nf_bridge); 2722 skb->nf_bridge = NULL; 2723 #endif 2724 } 2725 2726 static inline void nf_reset_trace(struct sk_buff *skb) 2727 { 2728 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 2729 skb->nf_trace = 0; 2730 #endif 2731 } 2732 2733 /* Note: This doesn't put any conntrack and bridge info in dst. */ 2734 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2735 { 2736 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2737 dst->nfct = src->nfct; 2738 nf_conntrack_get(src->nfct); 2739 dst->nfctinfo = src->nfctinfo; 2740 #endif 2741 #ifdef CONFIG_BRIDGE_NETFILTER 2742 dst->nf_bridge = src->nf_bridge; 2743 nf_bridge_get(src->nf_bridge); 2744 #endif 2745 } 2746 2747 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2748 { 2749 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2750 nf_conntrack_put(dst->nfct); 2751 #endif 2752 #ifdef CONFIG_BRIDGE_NETFILTER 2753 nf_bridge_put(dst->nf_bridge); 2754 #endif 2755 __nf_copy(dst, src); 2756 } 2757 2758 #ifdef CONFIG_NETWORK_SECMARK 2759 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2760 { 2761 to->secmark = from->secmark; 2762 } 2763 2764 static inline void skb_init_secmark(struct sk_buff *skb) 2765 { 2766 skb->secmark = 0; 2767 } 2768 #else 2769 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2770 { } 2771 2772 static inline void skb_init_secmark(struct sk_buff *skb) 2773 { } 2774 #endif 2775 2776 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 2777 { 2778 skb->queue_mapping = queue_mapping; 2779 } 2780 2781 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 2782 { 2783 return skb->queue_mapping; 2784 } 2785 2786 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 2787 { 2788 to->queue_mapping = from->queue_mapping; 2789 } 2790 2791 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 2792 { 2793 skb->queue_mapping = rx_queue + 1; 2794 } 2795 2796 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 2797 { 2798 return skb->queue_mapping - 1; 2799 } 2800 2801 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 2802 { 2803 return skb->queue_mapping != 0; 2804 } 2805 2806 u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb, 2807 unsigned int num_tx_queues); 2808 2809 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 2810 { 2811 #ifdef CONFIG_XFRM 2812 return skb->sp; 2813 #else 2814 return NULL; 2815 #endif 2816 } 2817 2818 /* Keeps track of mac header offset relative to skb->head. 2819 * It is useful for TSO of Tunneling protocol. e.g. GRE. 2820 * For non-tunnel skb it points to skb_mac_header() and for 2821 * tunnel skb it points to outer mac header. 2822 * Keeps track of level of encapsulation of network headers. 2823 */ 2824 struct skb_gso_cb { 2825 int mac_offset; 2826 int encap_level; 2827 }; 2828 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb) 2829 2830 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) 2831 { 2832 return (skb_mac_header(inner_skb) - inner_skb->head) - 2833 SKB_GSO_CB(inner_skb)->mac_offset; 2834 } 2835 2836 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra) 2837 { 2838 int new_headroom, headroom; 2839 int ret; 2840 2841 headroom = skb_headroom(skb); 2842 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC); 2843 if (ret) 2844 return ret; 2845 2846 new_headroom = skb_headroom(skb); 2847 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom); 2848 return 0; 2849 } 2850 2851 static inline bool skb_is_gso(const struct sk_buff *skb) 2852 { 2853 return skb_shinfo(skb)->gso_size; 2854 } 2855 2856 /* Note: Should be called only if skb_is_gso(skb) is true */ 2857 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 2858 { 2859 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 2860 } 2861 2862 void __skb_warn_lro_forwarding(const struct sk_buff *skb); 2863 2864 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 2865 { 2866 /* LRO sets gso_size but not gso_type, whereas if GSO is really 2867 * wanted then gso_type will be set. */ 2868 const struct skb_shared_info *shinfo = skb_shinfo(skb); 2869 2870 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 2871 unlikely(shinfo->gso_type == 0)) { 2872 __skb_warn_lro_forwarding(skb); 2873 return true; 2874 } 2875 return false; 2876 } 2877 2878 static inline void skb_forward_csum(struct sk_buff *skb) 2879 { 2880 /* Unfortunately we don't support this one. Any brave souls? */ 2881 if (skb->ip_summed == CHECKSUM_COMPLETE) 2882 skb->ip_summed = CHECKSUM_NONE; 2883 } 2884 2885 /** 2886 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 2887 * @skb: skb to check 2888 * 2889 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 2890 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 2891 * use this helper, to document places where we make this assertion. 2892 */ 2893 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 2894 { 2895 #ifdef DEBUG 2896 BUG_ON(skb->ip_summed != CHECKSUM_NONE); 2897 #endif 2898 } 2899 2900 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 2901 2902 int skb_checksum_setup(struct sk_buff *skb, bool recalculate); 2903 2904 u32 __skb_get_poff(const struct sk_buff *skb); 2905 2906 /** 2907 * skb_head_is_locked - Determine if the skb->head is locked down 2908 * @skb: skb to check 2909 * 2910 * The head on skbs build around a head frag can be removed if they are 2911 * not cloned. This function returns true if the skb head is locked down 2912 * due to either being allocated via kmalloc, or by being a clone with 2913 * multiple references to the head. 2914 */ 2915 static inline bool skb_head_is_locked(const struct sk_buff *skb) 2916 { 2917 return !skb->head_frag || skb_cloned(skb); 2918 } 2919 #endif /* __KERNEL__ */ 2920 #endif /* _LINUX_SKBUFF_H */ 2921