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 36 /* Don't change this without changing skb_csum_unnecessary! */ 37 #define CHECKSUM_NONE 0 38 #define CHECKSUM_UNNECESSARY 1 39 #define CHECKSUM_COMPLETE 2 40 #define CHECKSUM_PARTIAL 3 41 42 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ 43 ~(SMP_CACHE_BYTES - 1)) 44 #define SKB_WITH_OVERHEAD(X) \ 45 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 46 #define SKB_MAX_ORDER(X, ORDER) \ 47 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 48 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 49 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 50 51 /* return minimum truesize of one skb containing X bytes of data */ 52 #define SKB_TRUESIZE(X) ((X) + \ 53 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \ 54 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 55 56 /* A. Checksumming of received packets by device. 57 * 58 * NONE: device failed to checksum this packet. 59 * skb->csum is undefined. 60 * 61 * UNNECESSARY: device parsed packet and wouldbe verified checksum. 62 * skb->csum is undefined. 63 * It is bad option, but, unfortunately, many of vendors do this. 64 * Apparently with secret goal to sell you new device, when you 65 * will add new protocol to your host. F.e. IPv6. 8) 66 * 67 * COMPLETE: the most generic way. Device supplied checksum of _all_ 68 * the packet as seen by netif_rx in skb->csum. 69 * NOTE: Even if device supports only some protocols, but 70 * is able to produce some skb->csum, it MUST use COMPLETE, 71 * not UNNECESSARY. 72 * 73 * PARTIAL: identical to the case for output below. This may occur 74 * on a packet received directly from another Linux OS, e.g., 75 * a virtualised Linux kernel on the same host. The packet can 76 * be treated in the same way as UNNECESSARY except that on 77 * output (i.e., forwarding) the checksum must be filled in 78 * by the OS or the hardware. 79 * 80 * B. Checksumming on output. 81 * 82 * NONE: skb is checksummed by protocol or csum is not required. 83 * 84 * PARTIAL: device is required to csum packet as seen by hard_start_xmit 85 * from skb->csum_start to the end and to record the checksum 86 * at skb->csum_start + skb->csum_offset. 87 * 88 * Device must show its capabilities in dev->features, set 89 * at device setup time. 90 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum 91 * everything. 92 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only 93 * TCP/UDP over IPv4. Sigh. Vendors like this 94 * way by an unknown reason. Though, see comment above 95 * about CHECKSUM_UNNECESSARY. 8) 96 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. 97 * 98 * UNNECESSARY: device will do per protocol specific csum. Protocol drivers 99 * that do not want net to perform the checksum calculation should use 100 * this flag in their outgoing skbs. 101 * NETIF_F_FCOE_CRC this indicates 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 struct net_device; 109 struct scatterlist; 110 struct pipe_inode_info; 111 112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 113 struct nf_conntrack { 114 atomic_t use; 115 }; 116 #endif 117 118 #ifdef CONFIG_BRIDGE_NETFILTER 119 struct nf_bridge_info { 120 atomic_t use; 121 unsigned int mask; 122 struct net_device *physindev; 123 struct net_device *physoutdev; 124 unsigned long data[32 / sizeof(unsigned long)]; 125 }; 126 #endif 127 128 struct sk_buff_head { 129 /* These two members must be first. */ 130 struct sk_buff *next; 131 struct sk_buff *prev; 132 133 __u32 qlen; 134 spinlock_t lock; 135 }; 136 137 struct sk_buff; 138 139 /* To allow 64K frame to be packed as single skb without frag_list we 140 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for 141 * buffers which do not start on a page boundary. 142 * 143 * Since GRO uses frags we allocate at least 16 regardless of page 144 * size. 145 */ 146 #if (65536/PAGE_SIZE + 1) < 16 147 #define MAX_SKB_FRAGS 16UL 148 #else 149 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) 150 #endif 151 152 typedef struct skb_frag_struct skb_frag_t; 153 154 struct skb_frag_struct { 155 struct { 156 struct page *p; 157 } page; 158 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 159 __u32 page_offset; 160 __u32 size; 161 #else 162 __u16 page_offset; 163 __u16 size; 164 #endif 165 }; 166 167 static inline unsigned int skb_frag_size(const skb_frag_t *frag) 168 { 169 return frag->size; 170 } 171 172 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) 173 { 174 frag->size = size; 175 } 176 177 static inline void skb_frag_size_add(skb_frag_t *frag, int delta) 178 { 179 frag->size += delta; 180 } 181 182 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) 183 { 184 frag->size -= delta; 185 } 186 187 #define HAVE_HW_TIME_STAMP 188 189 /** 190 * struct skb_shared_hwtstamps - hardware time stamps 191 * @hwtstamp: hardware time stamp transformed into duration 192 * since arbitrary point in time 193 * @syststamp: hwtstamp transformed to system time base 194 * 195 * Software time stamps generated by ktime_get_real() are stored in 196 * skb->tstamp. The relation between the different kinds of time 197 * stamps is as follows: 198 * 199 * syststamp and tstamp can be compared against each other in 200 * arbitrary combinations. The accuracy of a 201 * syststamp/tstamp/"syststamp from other device" comparison is 202 * limited by the accuracy of the transformation into system time 203 * base. This depends on the device driver and its underlying 204 * hardware. 205 * 206 * hwtstamps can only be compared against other hwtstamps from 207 * the same device. 208 * 209 * This structure is attached to packets as part of the 210 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 211 */ 212 struct skb_shared_hwtstamps { 213 ktime_t hwtstamp; 214 ktime_t syststamp; 215 }; 216 217 /* Definitions for tx_flags in struct skb_shared_info */ 218 enum { 219 /* generate hardware time stamp */ 220 SKBTX_HW_TSTAMP = 1 << 0, 221 222 /* generate software time stamp */ 223 SKBTX_SW_TSTAMP = 1 << 1, 224 225 /* device driver is going to provide hardware time stamp */ 226 SKBTX_IN_PROGRESS = 1 << 2, 227 228 /* device driver supports TX zero-copy buffers */ 229 SKBTX_DEV_ZEROCOPY = 1 << 3, 230 231 /* generate wifi status information (where possible) */ 232 SKBTX_WIFI_STATUS = 1 << 4, 233 234 /* This indicates at least one fragment might be overwritten 235 * (as in vmsplice(), sendfile() ...) 236 * If we need to compute a TX checksum, we'll need to copy 237 * all frags to avoid possible bad checksum 238 */ 239 SKBTX_SHARED_FRAG = 1 << 5, 240 }; 241 242 /* 243 * The callback notifies userspace to release buffers when skb DMA is done in 244 * lower device, the skb last reference should be 0 when calling this. 245 * The zerocopy_success argument is true if zero copy transmit occurred, 246 * false on data copy or out of memory error caused by data copy attempt. 247 * The ctx field is used to track device context. 248 * The desc field is used to track userspace buffer index. 249 */ 250 struct ubuf_info { 251 void (*callback)(struct ubuf_info *, bool zerocopy_success); 252 void *ctx; 253 unsigned long desc; 254 }; 255 256 /* This data is invariant across clones and lives at 257 * the end of the header data, ie. at skb->end. 258 */ 259 struct skb_shared_info { 260 unsigned char nr_frags; 261 __u8 tx_flags; 262 unsigned short gso_size; 263 /* Warning: this field is not always filled in (UFO)! */ 264 unsigned short gso_segs; 265 unsigned short gso_type; 266 struct sk_buff *frag_list; 267 struct skb_shared_hwtstamps hwtstamps; 268 __be32 ip6_frag_id; 269 270 /* 271 * Warning : all fields before dataref are cleared in __alloc_skb() 272 */ 273 atomic_t dataref; 274 275 /* Intermediate layers must ensure that destructor_arg 276 * remains valid until skb destructor */ 277 void * destructor_arg; 278 279 /* must be last field, see pskb_expand_head() */ 280 skb_frag_t frags[MAX_SKB_FRAGS]; 281 }; 282 283 /* We divide dataref into two halves. The higher 16 bits hold references 284 * to the payload part of skb->data. The lower 16 bits hold references to 285 * the entire skb->data. A clone of a headerless skb holds the length of 286 * the header in skb->hdr_len. 287 * 288 * All users must obey the rule that the skb->data reference count must be 289 * greater than or equal to the payload reference count. 290 * 291 * Holding a reference to the payload part means that the user does not 292 * care about modifications to the header part of skb->data. 293 */ 294 #define SKB_DATAREF_SHIFT 16 295 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 296 297 298 enum { 299 SKB_FCLONE_UNAVAILABLE, 300 SKB_FCLONE_ORIG, 301 SKB_FCLONE_CLONE, 302 }; 303 304 enum { 305 SKB_GSO_TCPV4 = 1 << 0, 306 SKB_GSO_UDP = 1 << 1, 307 308 /* This indicates the skb is from an untrusted source. */ 309 SKB_GSO_DODGY = 1 << 2, 310 311 /* This indicates the tcp segment has CWR set. */ 312 SKB_GSO_TCP_ECN = 1 << 3, 313 314 SKB_GSO_TCPV6 = 1 << 4, 315 316 SKB_GSO_FCOE = 1 << 5, 317 318 SKB_GSO_GRE = 1 << 6, 319 320 SKB_GSO_UDP_TUNNEL = 1 << 7, 321 }; 322 323 #if BITS_PER_LONG > 32 324 #define NET_SKBUFF_DATA_USES_OFFSET 1 325 #endif 326 327 #ifdef NET_SKBUFF_DATA_USES_OFFSET 328 typedef unsigned int sk_buff_data_t; 329 #else 330 typedef unsigned char *sk_buff_data_t; 331 #endif 332 333 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \ 334 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE) 335 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1 336 #endif 337 338 /** 339 * struct sk_buff - socket buffer 340 * @next: Next buffer in list 341 * @prev: Previous buffer in list 342 * @tstamp: Time we arrived 343 * @sk: Socket we are owned by 344 * @dev: Device we arrived on/are leaving by 345 * @cb: Control buffer. Free for use by every layer. Put private vars here 346 * @_skb_refdst: destination entry (with norefcount bit) 347 * @sp: the security path, used for xfrm 348 * @len: Length of actual data 349 * @data_len: Data length 350 * @mac_len: Length of link layer header 351 * @hdr_len: writable header length of cloned skb 352 * @csum: Checksum (must include start/offset pair) 353 * @csum_start: Offset from skb->head where checksumming should start 354 * @csum_offset: Offset from csum_start where checksum should be stored 355 * @priority: Packet queueing priority 356 * @local_df: allow local fragmentation 357 * @cloned: Head may be cloned (check refcnt to be sure) 358 * @ip_summed: Driver fed us an IP checksum 359 * @nohdr: Payload reference only, must not modify header 360 * @nfctinfo: Relationship of this skb to the connection 361 * @pkt_type: Packet class 362 * @fclone: skbuff clone status 363 * @ipvs_property: skbuff is owned by ipvs 364 * @peeked: this packet has been seen already, so stats have been 365 * done for it, don't do them again 366 * @nf_trace: netfilter packet trace flag 367 * @protocol: Packet protocol from driver 368 * @destructor: Destruct function 369 * @nfct: Associated connection, if any 370 * @nfct_reasm: netfilter conntrack re-assembly pointer 371 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 372 * @skb_iif: ifindex of device we arrived on 373 * @tc_index: Traffic control index 374 * @tc_verd: traffic control verdict 375 * @rxhash: the packet hash computed on receive 376 * @queue_mapping: Queue mapping for multiqueue devices 377 * @ndisc_nodetype: router type (from link layer) 378 * @ooo_okay: allow the mapping of a socket to a queue to be changed 379 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport 380 * ports. 381 * @wifi_acked_valid: wifi_acked was set 382 * @wifi_acked: whether frame was acked on wifi or not 383 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS 384 * @dma_cookie: a cookie to one of several possible DMA operations 385 * done by skb DMA functions 386 * @secmark: security marking 387 * @mark: Generic packet mark 388 * @dropcount: total number of sk_receive_queue overflows 389 * @vlan_tci: vlan tag control information 390 * @inner_transport_header: Inner transport layer header (encapsulation) 391 * @inner_network_header: Network layer header (encapsulation) 392 * @inner_mac_header: Link layer header (encapsulation) 393 * @transport_header: Transport layer header 394 * @network_header: Network layer header 395 * @mac_header: Link layer header 396 * @tail: Tail pointer 397 * @end: End pointer 398 * @head: Head of buffer 399 * @data: Data head pointer 400 * @truesize: Buffer size 401 * @users: User count - see {datagram,tcp}.c 402 */ 403 404 struct sk_buff { 405 /* These two members must be first. */ 406 struct sk_buff *next; 407 struct sk_buff *prev; 408 409 ktime_t tstamp; 410 411 struct sock *sk; 412 struct net_device *dev; 413 414 /* 415 * This is the control buffer. It is free to use for every 416 * layer. Please put your private variables there. If you 417 * want to keep them across layers you have to do a skb_clone() 418 * first. This is owned by whoever has the skb queued ATM. 419 */ 420 char cb[48] __aligned(8); 421 422 unsigned long _skb_refdst; 423 #ifdef CONFIG_XFRM 424 struct sec_path *sp; 425 #endif 426 unsigned int len, 427 data_len; 428 __u16 mac_len, 429 hdr_len; 430 union { 431 __wsum csum; 432 struct { 433 __u16 csum_start; 434 __u16 csum_offset; 435 }; 436 }; 437 __u32 priority; 438 kmemcheck_bitfield_begin(flags1); 439 __u8 local_df:1, 440 cloned:1, 441 ip_summed:2, 442 nohdr:1, 443 nfctinfo:3; 444 __u8 pkt_type:3, 445 fclone:2, 446 ipvs_property:1, 447 peeked:1, 448 nf_trace:1; 449 kmemcheck_bitfield_end(flags1); 450 __be16 protocol; 451 452 void (*destructor)(struct sk_buff *skb); 453 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 454 struct nf_conntrack *nfct; 455 #endif 456 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 457 struct sk_buff *nfct_reasm; 458 #endif 459 #ifdef CONFIG_BRIDGE_NETFILTER 460 struct nf_bridge_info *nf_bridge; 461 #endif 462 463 int skb_iif; 464 465 __u32 rxhash; 466 467 __u16 vlan_tci; 468 469 #ifdef CONFIG_NET_SCHED 470 __u16 tc_index; /* traffic control index */ 471 #ifdef CONFIG_NET_CLS_ACT 472 __u16 tc_verd; /* traffic control verdict */ 473 #endif 474 #endif 475 476 __u16 queue_mapping; 477 kmemcheck_bitfield_begin(flags2); 478 #ifdef CONFIG_IPV6_NDISC_NODETYPE 479 __u8 ndisc_nodetype:2; 480 #endif 481 __u8 pfmemalloc:1; 482 __u8 ooo_okay:1; 483 __u8 l4_rxhash:1; 484 __u8 wifi_acked_valid:1; 485 __u8 wifi_acked:1; 486 __u8 no_fcs:1; 487 __u8 head_frag:1; 488 /* Encapsulation protocol and NIC drivers should use 489 * this flag to indicate to each other if the skb contains 490 * encapsulated packet or not and maybe use the inner packet 491 * headers if needed 492 */ 493 __u8 encapsulation:1; 494 /* 7/9 bit hole (depending on ndisc_nodetype presence) */ 495 kmemcheck_bitfield_end(flags2); 496 497 #ifdef CONFIG_NET_DMA 498 dma_cookie_t dma_cookie; 499 #endif 500 #ifdef CONFIG_NETWORK_SECMARK 501 __u32 secmark; 502 #endif 503 union { 504 __u32 mark; 505 __u32 dropcount; 506 __u32 avail_size; 507 }; 508 509 sk_buff_data_t inner_transport_header; 510 sk_buff_data_t inner_network_header; 511 sk_buff_data_t inner_mac_header; 512 sk_buff_data_t transport_header; 513 sk_buff_data_t network_header; 514 sk_buff_data_t mac_header; 515 /* These elements must be at the end, see alloc_skb() for details. */ 516 sk_buff_data_t tail; 517 sk_buff_data_t end; 518 unsigned char *head, 519 *data; 520 unsigned int truesize; 521 atomic_t users; 522 }; 523 524 #ifdef __KERNEL__ 525 /* 526 * Handling routines are only of interest to the kernel 527 */ 528 #include <linux/slab.h> 529 530 531 #define SKB_ALLOC_FCLONE 0x01 532 #define SKB_ALLOC_RX 0x02 533 534 /* Returns true if the skb was allocated from PFMEMALLOC reserves */ 535 static inline bool skb_pfmemalloc(const struct sk_buff *skb) 536 { 537 return unlikely(skb->pfmemalloc); 538 } 539 540 /* 541 * skb might have a dst pointer attached, refcounted or not. 542 * _skb_refdst low order bit is set if refcount was _not_ taken 543 */ 544 #define SKB_DST_NOREF 1UL 545 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 546 547 /** 548 * skb_dst - returns skb dst_entry 549 * @skb: buffer 550 * 551 * Returns skb dst_entry, regardless of reference taken or not. 552 */ 553 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 554 { 555 /* If refdst was not refcounted, check we still are in a 556 * rcu_read_lock section 557 */ 558 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 559 !rcu_read_lock_held() && 560 !rcu_read_lock_bh_held()); 561 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 562 } 563 564 /** 565 * skb_dst_set - sets skb dst 566 * @skb: buffer 567 * @dst: dst entry 568 * 569 * Sets skb dst, assuming a reference was taken on dst and should 570 * be released by skb_dst_drop() 571 */ 572 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 573 { 574 skb->_skb_refdst = (unsigned long)dst; 575 } 576 577 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst); 578 579 /** 580 * skb_dst_is_noref - Test if skb dst isn't refcounted 581 * @skb: buffer 582 */ 583 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 584 { 585 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 586 } 587 588 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 589 { 590 return (struct rtable *)skb_dst(skb); 591 } 592 593 extern void kfree_skb(struct sk_buff *skb); 594 extern void skb_tx_error(struct sk_buff *skb); 595 extern void consume_skb(struct sk_buff *skb); 596 extern void __kfree_skb(struct sk_buff *skb); 597 extern struct kmem_cache *skbuff_head_cache; 598 599 extern void kfree_skb_partial(struct sk_buff *skb, bool head_stolen); 600 extern bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 601 bool *fragstolen, int *delta_truesize); 602 603 extern struct sk_buff *__alloc_skb(unsigned int size, 604 gfp_t priority, int flags, int node); 605 extern struct sk_buff *build_skb(void *data, unsigned int frag_size); 606 static inline struct sk_buff *alloc_skb(unsigned int size, 607 gfp_t priority) 608 { 609 return __alloc_skb(size, priority, 0, NUMA_NO_NODE); 610 } 611 612 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 613 gfp_t priority) 614 { 615 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE); 616 } 617 618 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 619 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask); 620 extern struct sk_buff *skb_clone(struct sk_buff *skb, 621 gfp_t priority); 622 extern struct sk_buff *skb_copy(const struct sk_buff *skb, 623 gfp_t priority); 624 extern struct sk_buff *__pskb_copy(struct sk_buff *skb, 625 int headroom, gfp_t gfp_mask); 626 627 extern int pskb_expand_head(struct sk_buff *skb, 628 int nhead, int ntail, 629 gfp_t gfp_mask); 630 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 631 unsigned int headroom); 632 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 633 int newheadroom, int newtailroom, 634 gfp_t priority); 635 extern int skb_to_sgvec(struct sk_buff *skb, 636 struct scatterlist *sg, int offset, 637 int len); 638 extern int skb_cow_data(struct sk_buff *skb, int tailbits, 639 struct sk_buff **trailer); 640 extern int skb_pad(struct sk_buff *skb, int pad); 641 #define dev_kfree_skb(a) consume_skb(a) 642 643 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 644 int getfrag(void *from, char *to, int offset, 645 int len,int odd, struct sk_buff *skb), 646 void *from, int length); 647 648 struct skb_seq_state { 649 __u32 lower_offset; 650 __u32 upper_offset; 651 __u32 frag_idx; 652 __u32 stepped_offset; 653 struct sk_buff *root_skb; 654 struct sk_buff *cur_skb; 655 __u8 *frag_data; 656 }; 657 658 extern void skb_prepare_seq_read(struct sk_buff *skb, 659 unsigned int from, unsigned int to, 660 struct skb_seq_state *st); 661 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 662 struct skb_seq_state *st); 663 extern void skb_abort_seq_read(struct skb_seq_state *st); 664 665 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 666 unsigned int to, struct ts_config *config, 667 struct ts_state *state); 668 669 extern void __skb_get_rxhash(struct sk_buff *skb); 670 static inline __u32 skb_get_rxhash(struct sk_buff *skb) 671 { 672 if (!skb->l4_rxhash) 673 __skb_get_rxhash(skb); 674 675 return skb->rxhash; 676 } 677 678 #ifdef NET_SKBUFF_DATA_USES_OFFSET 679 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 680 { 681 return skb->head + skb->end; 682 } 683 684 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 685 { 686 return skb->end; 687 } 688 #else 689 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 690 { 691 return skb->end; 692 } 693 694 static inline unsigned int skb_end_offset(const struct sk_buff *skb) 695 { 696 return skb->end - skb->head; 697 } 698 #endif 699 700 /* Internal */ 701 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 702 703 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 704 { 705 return &skb_shinfo(skb)->hwtstamps; 706 } 707 708 /** 709 * skb_queue_empty - check if a queue is empty 710 * @list: queue head 711 * 712 * Returns true if the queue is empty, false otherwise. 713 */ 714 static inline int skb_queue_empty(const struct sk_buff_head *list) 715 { 716 return list->next == (struct sk_buff *)list; 717 } 718 719 /** 720 * skb_queue_is_last - check if skb is the last entry in the queue 721 * @list: queue head 722 * @skb: buffer 723 * 724 * Returns true if @skb is the last buffer on the list. 725 */ 726 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 727 const struct sk_buff *skb) 728 { 729 return skb->next == (struct sk_buff *)list; 730 } 731 732 /** 733 * skb_queue_is_first - check if skb is the first entry in the queue 734 * @list: queue head 735 * @skb: buffer 736 * 737 * Returns true if @skb is the first buffer on the list. 738 */ 739 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 740 const struct sk_buff *skb) 741 { 742 return skb->prev == (struct sk_buff *)list; 743 } 744 745 /** 746 * skb_queue_next - return the next packet in the queue 747 * @list: queue head 748 * @skb: current buffer 749 * 750 * Return the next packet in @list after @skb. It is only valid to 751 * call this if skb_queue_is_last() evaluates to false. 752 */ 753 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 754 const struct sk_buff *skb) 755 { 756 /* This BUG_ON may seem severe, but if we just return then we 757 * are going to dereference garbage. 758 */ 759 BUG_ON(skb_queue_is_last(list, skb)); 760 return skb->next; 761 } 762 763 /** 764 * skb_queue_prev - return the prev packet in the queue 765 * @list: queue head 766 * @skb: current buffer 767 * 768 * Return the prev packet in @list before @skb. It is only valid to 769 * call this if skb_queue_is_first() evaluates to false. 770 */ 771 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 772 const struct sk_buff *skb) 773 { 774 /* This BUG_ON may seem severe, but if we just return then we 775 * are going to dereference garbage. 776 */ 777 BUG_ON(skb_queue_is_first(list, skb)); 778 return skb->prev; 779 } 780 781 /** 782 * skb_get - reference buffer 783 * @skb: buffer to reference 784 * 785 * Makes another reference to a socket buffer and returns a pointer 786 * to the buffer. 787 */ 788 static inline struct sk_buff *skb_get(struct sk_buff *skb) 789 { 790 atomic_inc(&skb->users); 791 return skb; 792 } 793 794 /* 795 * If users == 1, we are the only owner and are can avoid redundant 796 * atomic change. 797 */ 798 799 /** 800 * skb_cloned - is the buffer a clone 801 * @skb: buffer to check 802 * 803 * Returns true if the buffer was generated with skb_clone() and is 804 * one of multiple shared copies of the buffer. Cloned buffers are 805 * shared data so must not be written to under normal circumstances. 806 */ 807 static inline int skb_cloned(const struct sk_buff *skb) 808 { 809 return skb->cloned && 810 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 811 } 812 813 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) 814 { 815 might_sleep_if(pri & __GFP_WAIT); 816 817 if (skb_cloned(skb)) 818 return pskb_expand_head(skb, 0, 0, pri); 819 820 return 0; 821 } 822 823 /** 824 * skb_header_cloned - is the header a clone 825 * @skb: buffer to check 826 * 827 * Returns true if modifying the header part of the buffer requires 828 * the data to be copied. 829 */ 830 static inline int skb_header_cloned(const struct sk_buff *skb) 831 { 832 int dataref; 833 834 if (!skb->cloned) 835 return 0; 836 837 dataref = atomic_read(&skb_shinfo(skb)->dataref); 838 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 839 return dataref != 1; 840 } 841 842 /** 843 * skb_header_release - release reference to header 844 * @skb: buffer to operate on 845 * 846 * Drop a reference to the header part of the buffer. This is done 847 * by acquiring a payload reference. You must not read from the header 848 * part of skb->data after this. 849 */ 850 static inline void skb_header_release(struct sk_buff *skb) 851 { 852 BUG_ON(skb->nohdr); 853 skb->nohdr = 1; 854 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); 855 } 856 857 /** 858 * skb_shared - is the buffer shared 859 * @skb: buffer to check 860 * 861 * Returns true if more than one person has a reference to this 862 * buffer. 863 */ 864 static inline int skb_shared(const struct sk_buff *skb) 865 { 866 return atomic_read(&skb->users) != 1; 867 } 868 869 /** 870 * skb_share_check - check if buffer is shared and if so clone it 871 * @skb: buffer to check 872 * @pri: priority for memory allocation 873 * 874 * If the buffer is shared the buffer is cloned and the old copy 875 * drops a reference. A new clone with a single reference is returned. 876 * If the buffer is not shared the original buffer is returned. When 877 * being called from interrupt status or with spinlocks held pri must 878 * be GFP_ATOMIC. 879 * 880 * NULL is returned on a memory allocation failure. 881 */ 882 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri) 883 { 884 might_sleep_if(pri & __GFP_WAIT); 885 if (skb_shared(skb)) { 886 struct sk_buff *nskb = skb_clone(skb, pri); 887 888 if (likely(nskb)) 889 consume_skb(skb); 890 else 891 kfree_skb(skb); 892 skb = nskb; 893 } 894 return skb; 895 } 896 897 /* 898 * Copy shared buffers into a new sk_buff. We effectively do COW on 899 * packets to handle cases where we have a local reader and forward 900 * and a couple of other messy ones. The normal one is tcpdumping 901 * a packet thats being forwarded. 902 */ 903 904 /** 905 * skb_unshare - make a copy of a shared buffer 906 * @skb: buffer to check 907 * @pri: priority for memory allocation 908 * 909 * If the socket buffer is a clone then this function creates a new 910 * copy of the data, drops a reference count on the old copy and returns 911 * the new copy with the reference count at 1. If the buffer is not a clone 912 * the original buffer is returned. When called with a spinlock held or 913 * from interrupt state @pri must be %GFP_ATOMIC 914 * 915 * %NULL is returned on a memory allocation failure. 916 */ 917 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 918 gfp_t pri) 919 { 920 might_sleep_if(pri & __GFP_WAIT); 921 if (skb_cloned(skb)) { 922 struct sk_buff *nskb = skb_copy(skb, pri); 923 kfree_skb(skb); /* Free our shared copy */ 924 skb = nskb; 925 } 926 return skb; 927 } 928 929 /** 930 * skb_peek - peek at the head of an &sk_buff_head 931 * @list_: list to peek at 932 * 933 * Peek an &sk_buff. Unlike most other operations you _MUST_ 934 * be careful with this one. A peek leaves the buffer on the 935 * list and someone else may run off with it. You must hold 936 * the appropriate locks or have a private queue to do this. 937 * 938 * Returns %NULL for an empty list or a pointer to the head element. 939 * The reference count is not incremented and the reference is therefore 940 * volatile. Use with caution. 941 */ 942 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_) 943 { 944 struct sk_buff *skb = list_->next; 945 946 if (skb == (struct sk_buff *)list_) 947 skb = NULL; 948 return skb; 949 } 950 951 /** 952 * skb_peek_next - peek skb following the given one from a queue 953 * @skb: skb to start from 954 * @list_: list to peek at 955 * 956 * Returns %NULL when the end of the list is met or a pointer to the 957 * next element. The reference count is not incremented and the 958 * reference is therefore volatile. Use with caution. 959 */ 960 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb, 961 const struct sk_buff_head *list_) 962 { 963 struct sk_buff *next = skb->next; 964 965 if (next == (struct sk_buff *)list_) 966 next = NULL; 967 return next; 968 } 969 970 /** 971 * skb_peek_tail - peek at the tail of an &sk_buff_head 972 * @list_: list to peek at 973 * 974 * Peek an &sk_buff. Unlike most other operations you _MUST_ 975 * be careful with this one. A peek leaves the buffer on the 976 * list and someone else may run off with it. You must hold 977 * the appropriate locks or have a private queue to do this. 978 * 979 * Returns %NULL for an empty list or a pointer to the tail element. 980 * The reference count is not incremented and the reference is therefore 981 * volatile. Use with caution. 982 */ 983 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_) 984 { 985 struct sk_buff *skb = list_->prev; 986 987 if (skb == (struct sk_buff *)list_) 988 skb = NULL; 989 return skb; 990 991 } 992 993 /** 994 * skb_queue_len - get queue length 995 * @list_: list to measure 996 * 997 * Return the length of an &sk_buff queue. 998 */ 999 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 1000 { 1001 return list_->qlen; 1002 } 1003 1004 /** 1005 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 1006 * @list: queue to initialize 1007 * 1008 * This initializes only the list and queue length aspects of 1009 * an sk_buff_head object. This allows to initialize the list 1010 * aspects of an sk_buff_head without reinitializing things like 1011 * the spinlock. It can also be used for on-stack sk_buff_head 1012 * objects where the spinlock is known to not be used. 1013 */ 1014 static inline void __skb_queue_head_init(struct sk_buff_head *list) 1015 { 1016 list->prev = list->next = (struct sk_buff *)list; 1017 list->qlen = 0; 1018 } 1019 1020 /* 1021 * This function creates a split out lock class for each invocation; 1022 * this is needed for now since a whole lot of users of the skb-queue 1023 * infrastructure in drivers have different locking usage (in hardirq) 1024 * than the networking core (in softirq only). In the long run either the 1025 * network layer or drivers should need annotation to consolidate the 1026 * main types of usage into 3 classes. 1027 */ 1028 static inline void skb_queue_head_init(struct sk_buff_head *list) 1029 { 1030 spin_lock_init(&list->lock); 1031 __skb_queue_head_init(list); 1032 } 1033 1034 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 1035 struct lock_class_key *class) 1036 { 1037 skb_queue_head_init(list); 1038 lockdep_set_class(&list->lock, class); 1039 } 1040 1041 /* 1042 * Insert an sk_buff on a list. 1043 * 1044 * The "__skb_xxxx()" functions are the non-atomic ones that 1045 * can only be called with interrupts disabled. 1046 */ 1047 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); 1048 static inline void __skb_insert(struct sk_buff *newsk, 1049 struct sk_buff *prev, struct sk_buff *next, 1050 struct sk_buff_head *list) 1051 { 1052 newsk->next = next; 1053 newsk->prev = prev; 1054 next->prev = prev->next = newsk; 1055 list->qlen++; 1056 } 1057 1058 static inline void __skb_queue_splice(const struct sk_buff_head *list, 1059 struct sk_buff *prev, 1060 struct sk_buff *next) 1061 { 1062 struct sk_buff *first = list->next; 1063 struct sk_buff *last = list->prev; 1064 1065 first->prev = prev; 1066 prev->next = first; 1067 1068 last->next = next; 1069 next->prev = last; 1070 } 1071 1072 /** 1073 * skb_queue_splice - join two skb lists, this is designed for stacks 1074 * @list: the new list to add 1075 * @head: the place to add it in the first list 1076 */ 1077 static inline void skb_queue_splice(const struct sk_buff_head *list, 1078 struct sk_buff_head *head) 1079 { 1080 if (!skb_queue_empty(list)) { 1081 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1082 head->qlen += list->qlen; 1083 } 1084 } 1085 1086 /** 1087 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list 1088 * @list: the new list to add 1089 * @head: the place to add it in the first list 1090 * 1091 * The list at @list is reinitialised 1092 */ 1093 static inline void skb_queue_splice_init(struct sk_buff_head *list, 1094 struct sk_buff_head *head) 1095 { 1096 if (!skb_queue_empty(list)) { 1097 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 1098 head->qlen += list->qlen; 1099 __skb_queue_head_init(list); 1100 } 1101 } 1102 1103 /** 1104 * skb_queue_splice_tail - join two skb lists, each list being a queue 1105 * @list: the new list to add 1106 * @head: the place to add it in the first list 1107 */ 1108 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 1109 struct sk_buff_head *head) 1110 { 1111 if (!skb_queue_empty(list)) { 1112 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1113 head->qlen += list->qlen; 1114 } 1115 } 1116 1117 /** 1118 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list 1119 * @list: the new list to add 1120 * @head: the place to add it in the first list 1121 * 1122 * Each of the lists is a queue. 1123 * The list at @list is reinitialised 1124 */ 1125 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 1126 struct sk_buff_head *head) 1127 { 1128 if (!skb_queue_empty(list)) { 1129 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 1130 head->qlen += list->qlen; 1131 __skb_queue_head_init(list); 1132 } 1133 } 1134 1135 /** 1136 * __skb_queue_after - queue a buffer at the list head 1137 * @list: list to use 1138 * @prev: place after this buffer 1139 * @newsk: buffer to queue 1140 * 1141 * Queue a buffer int the middle of a list. This function takes no locks 1142 * and you must therefore hold required locks before calling it. 1143 * 1144 * A buffer cannot be placed on two lists at the same time. 1145 */ 1146 static inline void __skb_queue_after(struct sk_buff_head *list, 1147 struct sk_buff *prev, 1148 struct sk_buff *newsk) 1149 { 1150 __skb_insert(newsk, prev, prev->next, list); 1151 } 1152 1153 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk, 1154 struct sk_buff_head *list); 1155 1156 static inline void __skb_queue_before(struct sk_buff_head *list, 1157 struct sk_buff *next, 1158 struct sk_buff *newsk) 1159 { 1160 __skb_insert(newsk, next->prev, next, list); 1161 } 1162 1163 /** 1164 * __skb_queue_head - queue a buffer at the list head 1165 * @list: list to use 1166 * @newsk: buffer to queue 1167 * 1168 * Queue a buffer at the start of a list. This function takes no locks 1169 * and you must therefore hold required locks before calling it. 1170 * 1171 * A buffer cannot be placed on two lists at the same time. 1172 */ 1173 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 1174 static inline void __skb_queue_head(struct sk_buff_head *list, 1175 struct sk_buff *newsk) 1176 { 1177 __skb_queue_after(list, (struct sk_buff *)list, newsk); 1178 } 1179 1180 /** 1181 * __skb_queue_tail - queue a buffer at the list tail 1182 * @list: list to use 1183 * @newsk: buffer to queue 1184 * 1185 * Queue a buffer at the end of a list. This function takes no locks 1186 * and you must therefore hold required locks before calling it. 1187 * 1188 * A buffer cannot be placed on two lists at the same time. 1189 */ 1190 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 1191 static inline void __skb_queue_tail(struct sk_buff_head *list, 1192 struct sk_buff *newsk) 1193 { 1194 __skb_queue_before(list, (struct sk_buff *)list, newsk); 1195 } 1196 1197 /* 1198 * remove sk_buff from list. _Must_ be called atomically, and with 1199 * the list known.. 1200 */ 1201 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 1202 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 1203 { 1204 struct sk_buff *next, *prev; 1205 1206 list->qlen--; 1207 next = skb->next; 1208 prev = skb->prev; 1209 skb->next = skb->prev = NULL; 1210 next->prev = prev; 1211 prev->next = next; 1212 } 1213 1214 /** 1215 * __skb_dequeue - remove from the head of the queue 1216 * @list: list to dequeue from 1217 * 1218 * Remove the head of the list. This function does not take any locks 1219 * so must be used with appropriate locks held only. The head item is 1220 * returned or %NULL if the list is empty. 1221 */ 1222 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); 1223 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 1224 { 1225 struct sk_buff *skb = skb_peek(list); 1226 if (skb) 1227 __skb_unlink(skb, list); 1228 return skb; 1229 } 1230 1231 /** 1232 * __skb_dequeue_tail - remove from the tail of the queue 1233 * @list: list to dequeue from 1234 * 1235 * Remove the tail of the list. This function does not take any locks 1236 * so must be used with appropriate locks held only. The tail item is 1237 * returned or %NULL if the list is empty. 1238 */ 1239 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 1240 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 1241 { 1242 struct sk_buff *skb = skb_peek_tail(list); 1243 if (skb) 1244 __skb_unlink(skb, list); 1245 return skb; 1246 } 1247 1248 1249 static inline bool skb_is_nonlinear(const struct sk_buff *skb) 1250 { 1251 return skb->data_len; 1252 } 1253 1254 static inline unsigned int skb_headlen(const struct sk_buff *skb) 1255 { 1256 return skb->len - skb->data_len; 1257 } 1258 1259 static inline int skb_pagelen(const struct sk_buff *skb) 1260 { 1261 int i, len = 0; 1262 1263 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) 1264 len += skb_frag_size(&skb_shinfo(skb)->frags[i]); 1265 return len + skb_headlen(skb); 1266 } 1267 1268 /** 1269 * __skb_fill_page_desc - initialise a paged fragment in an skb 1270 * @skb: buffer containing fragment to be initialised 1271 * @i: paged fragment index to initialise 1272 * @page: the page to use for this fragment 1273 * @off: the offset to the data with @page 1274 * @size: the length of the data 1275 * 1276 * Initialises the @i'th fragment of @skb to point to &size bytes at 1277 * offset @off within @page. 1278 * 1279 * Does not take any additional reference on the fragment. 1280 */ 1281 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, 1282 struct page *page, int off, int size) 1283 { 1284 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 1285 1286 /* 1287 * Propagate page->pfmemalloc to the skb if we can. The problem is 1288 * that not all callers have unique ownership of the page. If 1289 * pfmemalloc is set, we check the mapping as a mapping implies 1290 * page->index is set (index and pfmemalloc share space). 1291 * If it's a valid mapping, we cannot use page->pfmemalloc but we 1292 * do not lose pfmemalloc information as the pages would not be 1293 * allocated using __GFP_MEMALLOC. 1294 */ 1295 if (page->pfmemalloc && !page->mapping) 1296 skb->pfmemalloc = true; 1297 frag->page.p = page; 1298 frag->page_offset = off; 1299 skb_frag_size_set(frag, size); 1300 } 1301 1302 /** 1303 * skb_fill_page_desc - initialise a paged fragment in an skb 1304 * @skb: buffer containing fragment to be initialised 1305 * @i: paged fragment index to initialise 1306 * @page: the page to use for this fragment 1307 * @off: the offset to the data with @page 1308 * @size: the length of the data 1309 * 1310 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of 1311 * @skb to point to &size bytes at offset @off within @page. In 1312 * addition updates @skb such that @i is the last fragment. 1313 * 1314 * Does not take any additional reference on the fragment. 1315 */ 1316 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 1317 struct page *page, int off, int size) 1318 { 1319 __skb_fill_page_desc(skb, i, page, off, size); 1320 skb_shinfo(skb)->nr_frags = i + 1; 1321 } 1322 1323 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, 1324 int off, int size, unsigned int truesize); 1325 1326 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) 1327 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) 1328 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 1329 1330 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1331 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1332 { 1333 return skb->head + skb->tail; 1334 } 1335 1336 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1337 { 1338 skb->tail = skb->data - skb->head; 1339 } 1340 1341 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1342 { 1343 skb_reset_tail_pointer(skb); 1344 skb->tail += offset; 1345 } 1346 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1347 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1348 { 1349 return skb->tail; 1350 } 1351 1352 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1353 { 1354 skb->tail = skb->data; 1355 } 1356 1357 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1358 { 1359 skb->tail = skb->data + offset; 1360 } 1361 1362 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1363 1364 /* 1365 * Add data to an sk_buff 1366 */ 1367 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len); 1368 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) 1369 { 1370 unsigned char *tmp = skb_tail_pointer(skb); 1371 SKB_LINEAR_ASSERT(skb); 1372 skb->tail += len; 1373 skb->len += len; 1374 return tmp; 1375 } 1376 1377 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len); 1378 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) 1379 { 1380 skb->data -= len; 1381 skb->len += len; 1382 return skb->data; 1383 } 1384 1385 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); 1386 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) 1387 { 1388 skb->len -= len; 1389 BUG_ON(skb->len < skb->data_len); 1390 return skb->data += len; 1391 } 1392 1393 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) 1394 { 1395 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 1396 } 1397 1398 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); 1399 1400 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) 1401 { 1402 if (len > skb_headlen(skb) && 1403 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 1404 return NULL; 1405 skb->len -= len; 1406 return skb->data += len; 1407 } 1408 1409 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) 1410 { 1411 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 1412 } 1413 1414 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) 1415 { 1416 if (likely(len <= skb_headlen(skb))) 1417 return 1; 1418 if (unlikely(len > skb->len)) 1419 return 0; 1420 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 1421 } 1422 1423 /** 1424 * skb_headroom - bytes at buffer head 1425 * @skb: buffer to check 1426 * 1427 * Return the number of bytes of free space at the head of an &sk_buff. 1428 */ 1429 static inline unsigned int skb_headroom(const struct sk_buff *skb) 1430 { 1431 return skb->data - skb->head; 1432 } 1433 1434 /** 1435 * skb_tailroom - bytes at buffer end 1436 * @skb: buffer to check 1437 * 1438 * Return the number of bytes of free space at the tail of an sk_buff 1439 */ 1440 static inline int skb_tailroom(const struct sk_buff *skb) 1441 { 1442 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 1443 } 1444 1445 /** 1446 * skb_availroom - bytes at buffer end 1447 * @skb: buffer to check 1448 * 1449 * Return the number of bytes of free space at the tail of an sk_buff 1450 * allocated by sk_stream_alloc() 1451 */ 1452 static inline int skb_availroom(const struct sk_buff *skb) 1453 { 1454 return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len; 1455 } 1456 1457 /** 1458 * skb_reserve - adjust headroom 1459 * @skb: buffer to alter 1460 * @len: bytes to move 1461 * 1462 * Increase the headroom of an empty &sk_buff by reducing the tail 1463 * room. This is only allowed for an empty buffer. 1464 */ 1465 static inline void skb_reserve(struct sk_buff *skb, int len) 1466 { 1467 skb->data += len; 1468 skb->tail += len; 1469 } 1470 1471 static inline void skb_reset_inner_headers(struct sk_buff *skb) 1472 { 1473 skb->inner_mac_header = skb->mac_header; 1474 skb->inner_network_header = skb->network_header; 1475 skb->inner_transport_header = skb->transport_header; 1476 } 1477 1478 static inline void skb_reset_mac_len(struct sk_buff *skb) 1479 { 1480 skb->mac_len = skb->network_header - skb->mac_header; 1481 } 1482 1483 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1484 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 1485 *skb) 1486 { 1487 return skb->head + skb->inner_transport_header; 1488 } 1489 1490 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 1491 { 1492 skb->inner_transport_header = skb->data - skb->head; 1493 } 1494 1495 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 1496 const int offset) 1497 { 1498 skb_reset_inner_transport_header(skb); 1499 skb->inner_transport_header += offset; 1500 } 1501 1502 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 1503 { 1504 return skb->head + skb->inner_network_header; 1505 } 1506 1507 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 1508 { 1509 skb->inner_network_header = skb->data - skb->head; 1510 } 1511 1512 static inline void skb_set_inner_network_header(struct sk_buff *skb, 1513 const int offset) 1514 { 1515 skb_reset_inner_network_header(skb); 1516 skb->inner_network_header += offset; 1517 } 1518 1519 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 1520 { 1521 return skb->head + skb->inner_mac_header; 1522 } 1523 1524 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 1525 { 1526 skb->inner_mac_header = skb->data - skb->head; 1527 } 1528 1529 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 1530 const int offset) 1531 { 1532 skb_reset_inner_mac_header(skb); 1533 skb->inner_mac_header += offset; 1534 } 1535 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 1536 { 1537 return skb->transport_header != ~0U; 1538 } 1539 1540 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1541 { 1542 return skb->head + skb->transport_header; 1543 } 1544 1545 static inline void skb_reset_transport_header(struct sk_buff *skb) 1546 { 1547 skb->transport_header = skb->data - skb->head; 1548 } 1549 1550 static inline void skb_set_transport_header(struct sk_buff *skb, 1551 const int offset) 1552 { 1553 skb_reset_transport_header(skb); 1554 skb->transport_header += offset; 1555 } 1556 1557 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 1558 { 1559 return skb->head + skb->network_header; 1560 } 1561 1562 static inline void skb_reset_network_header(struct sk_buff *skb) 1563 { 1564 skb->network_header = skb->data - skb->head; 1565 } 1566 1567 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 1568 { 1569 skb_reset_network_header(skb); 1570 skb->network_header += offset; 1571 } 1572 1573 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 1574 { 1575 return skb->head + skb->mac_header; 1576 } 1577 1578 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 1579 { 1580 return skb->mac_header != ~0U; 1581 } 1582 1583 static inline void skb_reset_mac_header(struct sk_buff *skb) 1584 { 1585 skb->mac_header = skb->data - skb->head; 1586 } 1587 1588 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 1589 { 1590 skb_reset_mac_header(skb); 1591 skb->mac_header += offset; 1592 } 1593 1594 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1595 static inline unsigned char *skb_inner_transport_header(const struct sk_buff 1596 *skb) 1597 { 1598 return skb->inner_transport_header; 1599 } 1600 1601 static inline void skb_reset_inner_transport_header(struct sk_buff *skb) 1602 { 1603 skb->inner_transport_header = skb->data; 1604 } 1605 1606 static inline void skb_set_inner_transport_header(struct sk_buff *skb, 1607 const int offset) 1608 { 1609 skb->inner_transport_header = skb->data + offset; 1610 } 1611 1612 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb) 1613 { 1614 return skb->inner_network_header; 1615 } 1616 1617 static inline void skb_reset_inner_network_header(struct sk_buff *skb) 1618 { 1619 skb->inner_network_header = skb->data; 1620 } 1621 1622 static inline void skb_set_inner_network_header(struct sk_buff *skb, 1623 const int offset) 1624 { 1625 skb->inner_network_header = skb->data + offset; 1626 } 1627 1628 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb) 1629 { 1630 return skb->inner_mac_header; 1631 } 1632 1633 static inline void skb_reset_inner_mac_header(struct sk_buff *skb) 1634 { 1635 skb->inner_mac_header = skb->data; 1636 } 1637 1638 static inline void skb_set_inner_mac_header(struct sk_buff *skb, 1639 const int offset) 1640 { 1641 skb->inner_mac_header = skb->data + offset; 1642 } 1643 static inline bool skb_transport_header_was_set(const struct sk_buff *skb) 1644 { 1645 return skb->transport_header != NULL; 1646 } 1647 1648 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1649 { 1650 return skb->transport_header; 1651 } 1652 1653 static inline void skb_reset_transport_header(struct sk_buff *skb) 1654 { 1655 skb->transport_header = skb->data; 1656 } 1657 1658 static inline void skb_set_transport_header(struct sk_buff *skb, 1659 const int offset) 1660 { 1661 skb->transport_header = skb->data + offset; 1662 } 1663 1664 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 1665 { 1666 return skb->network_header; 1667 } 1668 1669 static inline void skb_reset_network_header(struct sk_buff *skb) 1670 { 1671 skb->network_header = skb->data; 1672 } 1673 1674 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 1675 { 1676 skb->network_header = skb->data + offset; 1677 } 1678 1679 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 1680 { 1681 return skb->mac_header; 1682 } 1683 1684 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 1685 { 1686 return skb->mac_header != NULL; 1687 } 1688 1689 static inline void skb_reset_mac_header(struct sk_buff *skb) 1690 { 1691 skb->mac_header = skb->data; 1692 } 1693 1694 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 1695 { 1696 skb->mac_header = skb->data + offset; 1697 } 1698 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1699 1700 static inline void skb_mac_header_rebuild(struct sk_buff *skb) 1701 { 1702 if (skb_mac_header_was_set(skb)) { 1703 const unsigned char *old_mac = skb_mac_header(skb); 1704 1705 skb_set_mac_header(skb, -skb->mac_len); 1706 memmove(skb_mac_header(skb), old_mac, skb->mac_len); 1707 } 1708 } 1709 1710 static inline int skb_checksum_start_offset(const struct sk_buff *skb) 1711 { 1712 return skb->csum_start - skb_headroom(skb); 1713 } 1714 1715 static inline int skb_transport_offset(const struct sk_buff *skb) 1716 { 1717 return skb_transport_header(skb) - skb->data; 1718 } 1719 1720 static inline u32 skb_network_header_len(const struct sk_buff *skb) 1721 { 1722 return skb->transport_header - skb->network_header; 1723 } 1724 1725 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb) 1726 { 1727 return skb->inner_transport_header - skb->inner_network_header; 1728 } 1729 1730 static inline int skb_network_offset(const struct sk_buff *skb) 1731 { 1732 return skb_network_header(skb) - skb->data; 1733 } 1734 1735 static inline int skb_inner_network_offset(const struct sk_buff *skb) 1736 { 1737 return skb_inner_network_header(skb) - skb->data; 1738 } 1739 1740 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 1741 { 1742 return pskb_may_pull(skb, skb_network_offset(skb) + len); 1743 } 1744 1745 /* 1746 * CPUs often take a performance hit when accessing unaligned memory 1747 * locations. The actual performance hit varies, it can be small if the 1748 * hardware handles it or large if we have to take an exception and fix it 1749 * in software. 1750 * 1751 * Since an ethernet header is 14 bytes network drivers often end up with 1752 * the IP header at an unaligned offset. The IP header can be aligned by 1753 * shifting the start of the packet by 2 bytes. Drivers should do this 1754 * with: 1755 * 1756 * skb_reserve(skb, NET_IP_ALIGN); 1757 * 1758 * The downside to this alignment of the IP header is that the DMA is now 1759 * unaligned. On some architectures the cost of an unaligned DMA is high 1760 * and this cost outweighs the gains made by aligning the IP header. 1761 * 1762 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 1763 * to be overridden. 1764 */ 1765 #ifndef NET_IP_ALIGN 1766 #define NET_IP_ALIGN 2 1767 #endif 1768 1769 /* 1770 * The networking layer reserves some headroom in skb data (via 1771 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 1772 * the header has to grow. In the default case, if the header has to grow 1773 * 32 bytes or less we avoid the reallocation. 1774 * 1775 * Unfortunately this headroom changes the DMA alignment of the resulting 1776 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 1777 * on some architectures. An architecture can override this value, 1778 * perhaps setting it to a cacheline in size (since that will maintain 1779 * cacheline alignment of the DMA). It must be a power of 2. 1780 * 1781 * Various parts of the networking layer expect at least 32 bytes of 1782 * headroom, you should not reduce this. 1783 * 1784 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 1785 * to reduce average number of cache lines per packet. 1786 * get_rps_cpus() for example only access one 64 bytes aligned block : 1787 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 1788 */ 1789 #ifndef NET_SKB_PAD 1790 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 1791 #endif 1792 1793 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); 1794 1795 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 1796 { 1797 if (unlikely(skb_is_nonlinear(skb))) { 1798 WARN_ON(1); 1799 return; 1800 } 1801 skb->len = len; 1802 skb_set_tail_pointer(skb, len); 1803 } 1804 1805 extern void skb_trim(struct sk_buff *skb, unsigned int len); 1806 1807 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 1808 { 1809 if (skb->data_len) 1810 return ___pskb_trim(skb, len); 1811 __skb_trim(skb, len); 1812 return 0; 1813 } 1814 1815 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 1816 { 1817 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 1818 } 1819 1820 /** 1821 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 1822 * @skb: buffer to alter 1823 * @len: new length 1824 * 1825 * This is identical to pskb_trim except that the caller knows that 1826 * the skb is not cloned so we should never get an error due to out- 1827 * of-memory. 1828 */ 1829 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 1830 { 1831 int err = pskb_trim(skb, len); 1832 BUG_ON(err); 1833 } 1834 1835 /** 1836 * skb_orphan - orphan a buffer 1837 * @skb: buffer to orphan 1838 * 1839 * If a buffer currently has an owner then we call the owner's 1840 * destructor function and make the @skb unowned. The buffer continues 1841 * to exist but is no longer charged to its former owner. 1842 */ 1843 static inline void skb_orphan(struct sk_buff *skb) 1844 { 1845 if (skb->destructor) 1846 skb->destructor(skb); 1847 skb->destructor = NULL; 1848 skb->sk = NULL; 1849 } 1850 1851 /** 1852 * skb_orphan_frags - orphan the frags contained in a buffer 1853 * @skb: buffer to orphan frags from 1854 * @gfp_mask: allocation mask for replacement pages 1855 * 1856 * For each frag in the SKB which needs a destructor (i.e. has an 1857 * owner) create a copy of that frag and release the original 1858 * page by calling the destructor. 1859 */ 1860 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask) 1861 { 1862 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))) 1863 return 0; 1864 return skb_copy_ubufs(skb, gfp_mask); 1865 } 1866 1867 /** 1868 * __skb_queue_purge - empty a list 1869 * @list: list to empty 1870 * 1871 * Delete all buffers on an &sk_buff list. Each buffer is removed from 1872 * the list and one reference dropped. This function does not take the 1873 * list lock and the caller must hold the relevant locks to use it. 1874 */ 1875 extern void skb_queue_purge(struct sk_buff_head *list); 1876 static inline void __skb_queue_purge(struct sk_buff_head *list) 1877 { 1878 struct sk_buff *skb; 1879 while ((skb = __skb_dequeue(list)) != NULL) 1880 kfree_skb(skb); 1881 } 1882 1883 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768) 1884 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER) 1885 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE 1886 1887 extern void *netdev_alloc_frag(unsigned int fragsz); 1888 1889 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, 1890 unsigned int length, 1891 gfp_t gfp_mask); 1892 1893 /** 1894 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 1895 * @dev: network device to receive on 1896 * @length: length to allocate 1897 * 1898 * Allocate a new &sk_buff and assign it a usage count of one. The 1899 * buffer has unspecified headroom built in. Users should allocate 1900 * the headroom they think they need without accounting for the 1901 * built in space. The built in space is used for optimisations. 1902 * 1903 * %NULL is returned if there is no free memory. Although this function 1904 * allocates memory it can be called from an interrupt. 1905 */ 1906 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 1907 unsigned int length) 1908 { 1909 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 1910 } 1911 1912 /* legacy helper around __netdev_alloc_skb() */ 1913 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 1914 gfp_t gfp_mask) 1915 { 1916 return __netdev_alloc_skb(NULL, length, gfp_mask); 1917 } 1918 1919 /* legacy helper around netdev_alloc_skb() */ 1920 static inline struct sk_buff *dev_alloc_skb(unsigned int length) 1921 { 1922 return netdev_alloc_skb(NULL, length); 1923 } 1924 1925 1926 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev, 1927 unsigned int length, gfp_t gfp) 1928 { 1929 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp); 1930 1931 if (NET_IP_ALIGN && skb) 1932 skb_reserve(skb, NET_IP_ALIGN); 1933 return skb; 1934 } 1935 1936 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 1937 unsigned int length) 1938 { 1939 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC); 1940 } 1941 1942 /* 1943 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data 1944 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX 1945 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used 1946 * @order: size of the allocation 1947 * 1948 * Allocate a new page. 1949 * 1950 * %NULL is returned if there is no free memory. 1951 */ 1952 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask, 1953 struct sk_buff *skb, 1954 unsigned int order) 1955 { 1956 struct page *page; 1957 1958 gfp_mask |= __GFP_COLD; 1959 1960 if (!(gfp_mask & __GFP_NOMEMALLOC)) 1961 gfp_mask |= __GFP_MEMALLOC; 1962 1963 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order); 1964 if (skb && page && page->pfmemalloc) 1965 skb->pfmemalloc = true; 1966 1967 return page; 1968 } 1969 1970 /** 1971 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data 1972 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX 1973 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used 1974 * 1975 * Allocate a new page. 1976 * 1977 * %NULL is returned if there is no free memory. 1978 */ 1979 static inline struct page *__skb_alloc_page(gfp_t gfp_mask, 1980 struct sk_buff *skb) 1981 { 1982 return __skb_alloc_pages(gfp_mask, skb, 0); 1983 } 1984 1985 /** 1986 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page 1987 * @page: The page that was allocated from skb_alloc_page 1988 * @skb: The skb that may need pfmemalloc set 1989 */ 1990 static inline void skb_propagate_pfmemalloc(struct page *page, 1991 struct sk_buff *skb) 1992 { 1993 if (page && page->pfmemalloc) 1994 skb->pfmemalloc = true; 1995 } 1996 1997 /** 1998 * skb_frag_page - retrieve the page refered to by a paged fragment 1999 * @frag: the paged fragment 2000 * 2001 * Returns the &struct page associated with @frag. 2002 */ 2003 static inline struct page *skb_frag_page(const skb_frag_t *frag) 2004 { 2005 return frag->page.p; 2006 } 2007 2008 /** 2009 * __skb_frag_ref - take an addition reference on a paged fragment. 2010 * @frag: the paged fragment 2011 * 2012 * Takes an additional reference on the paged fragment @frag. 2013 */ 2014 static inline void __skb_frag_ref(skb_frag_t *frag) 2015 { 2016 get_page(skb_frag_page(frag)); 2017 } 2018 2019 /** 2020 * skb_frag_ref - take an addition reference on a paged fragment of an skb. 2021 * @skb: the buffer 2022 * @f: the fragment offset. 2023 * 2024 * Takes an additional reference on the @f'th paged fragment of @skb. 2025 */ 2026 static inline void skb_frag_ref(struct sk_buff *skb, int f) 2027 { 2028 __skb_frag_ref(&skb_shinfo(skb)->frags[f]); 2029 } 2030 2031 /** 2032 * __skb_frag_unref - release a reference on a paged fragment. 2033 * @frag: the paged fragment 2034 * 2035 * Releases a reference on the paged fragment @frag. 2036 */ 2037 static inline void __skb_frag_unref(skb_frag_t *frag) 2038 { 2039 put_page(skb_frag_page(frag)); 2040 } 2041 2042 /** 2043 * skb_frag_unref - release a reference on a paged fragment of an skb. 2044 * @skb: the buffer 2045 * @f: the fragment offset 2046 * 2047 * Releases a reference on the @f'th paged fragment of @skb. 2048 */ 2049 static inline void skb_frag_unref(struct sk_buff *skb, int f) 2050 { 2051 __skb_frag_unref(&skb_shinfo(skb)->frags[f]); 2052 } 2053 2054 /** 2055 * skb_frag_address - gets the address of the data contained in a paged fragment 2056 * @frag: the paged fragment buffer 2057 * 2058 * Returns the address of the data within @frag. The page must already 2059 * be mapped. 2060 */ 2061 static inline void *skb_frag_address(const skb_frag_t *frag) 2062 { 2063 return page_address(skb_frag_page(frag)) + frag->page_offset; 2064 } 2065 2066 /** 2067 * skb_frag_address_safe - gets the address of the data contained in a paged fragment 2068 * @frag: the paged fragment buffer 2069 * 2070 * Returns the address of the data within @frag. Checks that the page 2071 * is mapped and returns %NULL otherwise. 2072 */ 2073 static inline void *skb_frag_address_safe(const skb_frag_t *frag) 2074 { 2075 void *ptr = page_address(skb_frag_page(frag)); 2076 if (unlikely(!ptr)) 2077 return NULL; 2078 2079 return ptr + frag->page_offset; 2080 } 2081 2082 /** 2083 * __skb_frag_set_page - sets the page contained in a paged fragment 2084 * @frag: the paged fragment 2085 * @page: the page to set 2086 * 2087 * Sets the fragment @frag to contain @page. 2088 */ 2089 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page) 2090 { 2091 frag->page.p = page; 2092 } 2093 2094 /** 2095 * skb_frag_set_page - sets the page contained in a paged fragment of an skb 2096 * @skb: the buffer 2097 * @f: the fragment offset 2098 * @page: the page to set 2099 * 2100 * Sets the @f'th fragment of @skb to contain @page. 2101 */ 2102 static inline void skb_frag_set_page(struct sk_buff *skb, int f, 2103 struct page *page) 2104 { 2105 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page); 2106 } 2107 2108 /** 2109 * skb_frag_dma_map - maps a paged fragment via the DMA API 2110 * @dev: the device to map the fragment to 2111 * @frag: the paged fragment to map 2112 * @offset: the offset within the fragment (starting at the 2113 * fragment's own offset) 2114 * @size: the number of bytes to map 2115 * @dir: the direction of the mapping (%PCI_DMA_*) 2116 * 2117 * Maps the page associated with @frag to @device. 2118 */ 2119 static inline dma_addr_t skb_frag_dma_map(struct device *dev, 2120 const skb_frag_t *frag, 2121 size_t offset, size_t size, 2122 enum dma_data_direction dir) 2123 { 2124 return dma_map_page(dev, skb_frag_page(frag), 2125 frag->page_offset + offset, size, dir); 2126 } 2127 2128 static inline struct sk_buff *pskb_copy(struct sk_buff *skb, 2129 gfp_t gfp_mask) 2130 { 2131 return __pskb_copy(skb, skb_headroom(skb), gfp_mask); 2132 } 2133 2134 /** 2135 * skb_clone_writable - is the header of a clone writable 2136 * @skb: buffer to check 2137 * @len: length up to which to write 2138 * 2139 * Returns true if modifying the header part of the cloned buffer 2140 * does not requires the data to be copied. 2141 */ 2142 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len) 2143 { 2144 return !skb_header_cloned(skb) && 2145 skb_headroom(skb) + len <= skb->hdr_len; 2146 } 2147 2148 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 2149 int cloned) 2150 { 2151 int delta = 0; 2152 2153 if (headroom > skb_headroom(skb)) 2154 delta = headroom - skb_headroom(skb); 2155 2156 if (delta || cloned) 2157 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 2158 GFP_ATOMIC); 2159 return 0; 2160 } 2161 2162 /** 2163 * skb_cow - copy header of skb when it is required 2164 * @skb: buffer to cow 2165 * @headroom: needed headroom 2166 * 2167 * If the skb passed lacks sufficient headroom or its data part 2168 * is shared, data is reallocated. If reallocation fails, an error 2169 * is returned and original skb is not changed. 2170 * 2171 * The result is skb with writable area skb->head...skb->tail 2172 * and at least @headroom of space at head. 2173 */ 2174 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 2175 { 2176 return __skb_cow(skb, headroom, skb_cloned(skb)); 2177 } 2178 2179 /** 2180 * skb_cow_head - skb_cow but only making the head writable 2181 * @skb: buffer to cow 2182 * @headroom: needed headroom 2183 * 2184 * This function is identical to skb_cow except that we replace the 2185 * skb_cloned check by skb_header_cloned. It should be used when 2186 * you only need to push on some header and do not need to modify 2187 * the data. 2188 */ 2189 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 2190 { 2191 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 2192 } 2193 2194 /** 2195 * skb_padto - pad an skbuff up to a minimal size 2196 * @skb: buffer to pad 2197 * @len: minimal length 2198 * 2199 * Pads up a buffer to ensure the trailing bytes exist and are 2200 * blanked. If the buffer already contains sufficient data it 2201 * is untouched. Otherwise it is extended. Returns zero on 2202 * success. The skb is freed on error. 2203 */ 2204 2205 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 2206 { 2207 unsigned int size = skb->len; 2208 if (likely(size >= len)) 2209 return 0; 2210 return skb_pad(skb, len - size); 2211 } 2212 2213 static inline int skb_add_data(struct sk_buff *skb, 2214 char __user *from, int copy) 2215 { 2216 const int off = skb->len; 2217 2218 if (skb->ip_summed == CHECKSUM_NONE) { 2219 int err = 0; 2220 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), 2221 copy, 0, &err); 2222 if (!err) { 2223 skb->csum = csum_block_add(skb->csum, csum, off); 2224 return 0; 2225 } 2226 } else if (!copy_from_user(skb_put(skb, copy), from, copy)) 2227 return 0; 2228 2229 __skb_trim(skb, off); 2230 return -EFAULT; 2231 } 2232 2233 static inline bool skb_can_coalesce(struct sk_buff *skb, int i, 2234 const struct page *page, int off) 2235 { 2236 if (i) { 2237 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; 2238 2239 return page == skb_frag_page(frag) && 2240 off == frag->page_offset + skb_frag_size(frag); 2241 } 2242 return false; 2243 } 2244 2245 static inline int __skb_linearize(struct sk_buff *skb) 2246 { 2247 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 2248 } 2249 2250 /** 2251 * skb_linearize - convert paged skb to linear one 2252 * @skb: buffer to linarize 2253 * 2254 * If there is no free memory -ENOMEM is returned, otherwise zero 2255 * is returned and the old skb data released. 2256 */ 2257 static inline int skb_linearize(struct sk_buff *skb) 2258 { 2259 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 2260 } 2261 2262 /** 2263 * skb_has_shared_frag - can any frag be overwritten 2264 * @skb: buffer to test 2265 * 2266 * Return true if the skb has at least one frag that might be modified 2267 * by an external entity (as in vmsplice()/sendfile()) 2268 */ 2269 static inline bool skb_has_shared_frag(const struct sk_buff *skb) 2270 { 2271 return skb_is_nonlinear(skb) && 2272 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; 2273 } 2274 2275 /** 2276 * skb_linearize_cow - make sure skb is linear and writable 2277 * @skb: buffer to process 2278 * 2279 * If there is no free memory -ENOMEM is returned, otherwise zero 2280 * is returned and the old skb data released. 2281 */ 2282 static inline int skb_linearize_cow(struct sk_buff *skb) 2283 { 2284 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 2285 __skb_linearize(skb) : 0; 2286 } 2287 2288 /** 2289 * skb_postpull_rcsum - update checksum for received skb after pull 2290 * @skb: buffer to update 2291 * @start: start of data before pull 2292 * @len: length of data pulled 2293 * 2294 * After doing a pull on a received packet, you need to call this to 2295 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 2296 * CHECKSUM_NONE so that it can be recomputed from scratch. 2297 */ 2298 2299 static inline void skb_postpull_rcsum(struct sk_buff *skb, 2300 const void *start, unsigned int len) 2301 { 2302 if (skb->ip_summed == CHECKSUM_COMPLETE) 2303 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); 2304 } 2305 2306 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 2307 2308 /** 2309 * pskb_trim_rcsum - trim received skb and update checksum 2310 * @skb: buffer to trim 2311 * @len: new length 2312 * 2313 * This is exactly the same as pskb_trim except that it ensures the 2314 * checksum of received packets are still valid after the operation. 2315 */ 2316 2317 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 2318 { 2319 if (likely(len >= skb->len)) 2320 return 0; 2321 if (skb->ip_summed == CHECKSUM_COMPLETE) 2322 skb->ip_summed = CHECKSUM_NONE; 2323 return __pskb_trim(skb, len); 2324 } 2325 2326 #define skb_queue_walk(queue, skb) \ 2327 for (skb = (queue)->next; \ 2328 skb != (struct sk_buff *)(queue); \ 2329 skb = skb->next) 2330 2331 #define skb_queue_walk_safe(queue, skb, tmp) \ 2332 for (skb = (queue)->next, tmp = skb->next; \ 2333 skb != (struct sk_buff *)(queue); \ 2334 skb = tmp, tmp = skb->next) 2335 2336 #define skb_queue_walk_from(queue, skb) \ 2337 for (; skb != (struct sk_buff *)(queue); \ 2338 skb = skb->next) 2339 2340 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 2341 for (tmp = skb->next; \ 2342 skb != (struct sk_buff *)(queue); \ 2343 skb = tmp, tmp = skb->next) 2344 2345 #define skb_queue_reverse_walk(queue, skb) \ 2346 for (skb = (queue)->prev; \ 2347 skb != (struct sk_buff *)(queue); \ 2348 skb = skb->prev) 2349 2350 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \ 2351 for (skb = (queue)->prev, tmp = skb->prev; \ 2352 skb != (struct sk_buff *)(queue); \ 2353 skb = tmp, tmp = skb->prev) 2354 2355 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \ 2356 for (tmp = skb->prev; \ 2357 skb != (struct sk_buff *)(queue); \ 2358 skb = tmp, tmp = skb->prev) 2359 2360 static inline bool skb_has_frag_list(const struct sk_buff *skb) 2361 { 2362 return skb_shinfo(skb)->frag_list != NULL; 2363 } 2364 2365 static inline void skb_frag_list_init(struct sk_buff *skb) 2366 { 2367 skb_shinfo(skb)->frag_list = NULL; 2368 } 2369 2370 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) 2371 { 2372 frag->next = skb_shinfo(skb)->frag_list; 2373 skb_shinfo(skb)->frag_list = frag; 2374 } 2375 2376 #define skb_walk_frags(skb, iter) \ 2377 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 2378 2379 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, 2380 int *peeked, int *off, int *err); 2381 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, 2382 int noblock, int *err); 2383 extern unsigned int datagram_poll(struct file *file, struct socket *sock, 2384 struct poll_table_struct *wait); 2385 extern int skb_copy_datagram_iovec(const struct sk_buff *from, 2386 int offset, struct iovec *to, 2387 int size); 2388 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, 2389 int hlen, 2390 struct iovec *iov); 2391 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, 2392 int offset, 2393 const struct iovec *from, 2394 int from_offset, 2395 int len); 2396 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, 2397 int offset, 2398 const struct iovec *to, 2399 int to_offset, 2400 int size); 2401 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 2402 extern void skb_free_datagram_locked(struct sock *sk, 2403 struct sk_buff *skb); 2404 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, 2405 unsigned int flags); 2406 extern __wsum skb_checksum(const struct sk_buff *skb, int offset, 2407 int len, __wsum csum); 2408 extern int skb_copy_bits(const struct sk_buff *skb, int offset, 2409 void *to, int len); 2410 extern int skb_store_bits(struct sk_buff *skb, int offset, 2411 const void *from, int len); 2412 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, 2413 int offset, u8 *to, int len, 2414 __wsum csum); 2415 extern int skb_splice_bits(struct sk_buff *skb, 2416 unsigned int offset, 2417 struct pipe_inode_info *pipe, 2418 unsigned int len, 2419 unsigned int flags); 2420 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 2421 extern void skb_split(struct sk_buff *skb, 2422 struct sk_buff *skb1, const u32 len); 2423 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, 2424 int shiftlen); 2425 2426 extern struct sk_buff *skb_segment(struct sk_buff *skb, 2427 netdev_features_t features); 2428 2429 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, 2430 int len, void *buffer) 2431 { 2432 int hlen = skb_headlen(skb); 2433 2434 if (hlen - offset >= len) 2435 return skb->data + offset; 2436 2437 if (skb_copy_bits(skb, offset, buffer, len) < 0) 2438 return NULL; 2439 2440 return buffer; 2441 } 2442 2443 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 2444 void *to, 2445 const unsigned int len) 2446 { 2447 memcpy(to, skb->data, len); 2448 } 2449 2450 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 2451 const int offset, void *to, 2452 const unsigned int len) 2453 { 2454 memcpy(to, skb->data + offset, len); 2455 } 2456 2457 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 2458 const void *from, 2459 const unsigned int len) 2460 { 2461 memcpy(skb->data, from, len); 2462 } 2463 2464 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 2465 const int offset, 2466 const void *from, 2467 const unsigned int len) 2468 { 2469 memcpy(skb->data + offset, from, len); 2470 } 2471 2472 extern void skb_init(void); 2473 2474 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 2475 { 2476 return skb->tstamp; 2477 } 2478 2479 /** 2480 * skb_get_timestamp - get timestamp from a skb 2481 * @skb: skb to get stamp from 2482 * @stamp: pointer to struct timeval to store stamp in 2483 * 2484 * Timestamps are stored in the skb as offsets to a base timestamp. 2485 * This function converts the offset back to a struct timeval and stores 2486 * it in stamp. 2487 */ 2488 static inline void skb_get_timestamp(const struct sk_buff *skb, 2489 struct timeval *stamp) 2490 { 2491 *stamp = ktime_to_timeval(skb->tstamp); 2492 } 2493 2494 static inline void skb_get_timestampns(const struct sk_buff *skb, 2495 struct timespec *stamp) 2496 { 2497 *stamp = ktime_to_timespec(skb->tstamp); 2498 } 2499 2500 static inline void __net_timestamp(struct sk_buff *skb) 2501 { 2502 skb->tstamp = ktime_get_real(); 2503 } 2504 2505 static inline ktime_t net_timedelta(ktime_t t) 2506 { 2507 return ktime_sub(ktime_get_real(), t); 2508 } 2509 2510 static inline ktime_t net_invalid_timestamp(void) 2511 { 2512 return ktime_set(0, 0); 2513 } 2514 2515 extern void skb_timestamping_init(void); 2516 2517 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 2518 2519 extern void skb_clone_tx_timestamp(struct sk_buff *skb); 2520 extern bool skb_defer_rx_timestamp(struct sk_buff *skb); 2521 2522 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 2523 2524 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 2525 { 2526 } 2527 2528 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 2529 { 2530 return false; 2531 } 2532 2533 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 2534 2535 /** 2536 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 2537 * 2538 * PHY drivers may accept clones of transmitted packets for 2539 * timestamping via their phy_driver.txtstamp method. These drivers 2540 * must call this function to return the skb back to the stack, with 2541 * or without a timestamp. 2542 * 2543 * @skb: clone of the the original outgoing packet 2544 * @hwtstamps: hardware time stamps, may be NULL if not available 2545 * 2546 */ 2547 void skb_complete_tx_timestamp(struct sk_buff *skb, 2548 struct skb_shared_hwtstamps *hwtstamps); 2549 2550 /** 2551 * skb_tstamp_tx - queue clone of skb with send time stamps 2552 * @orig_skb: the original outgoing packet 2553 * @hwtstamps: hardware time stamps, may be NULL if not available 2554 * 2555 * If the skb has a socket associated, then this function clones the 2556 * skb (thus sharing the actual data and optional structures), stores 2557 * the optional hardware time stamping information (if non NULL) or 2558 * generates a software time stamp (otherwise), then queues the clone 2559 * to the error queue of the socket. Errors are silently ignored. 2560 */ 2561 extern void skb_tstamp_tx(struct sk_buff *orig_skb, 2562 struct skb_shared_hwtstamps *hwtstamps); 2563 2564 static inline void sw_tx_timestamp(struct sk_buff *skb) 2565 { 2566 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && 2567 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 2568 skb_tstamp_tx(skb, NULL); 2569 } 2570 2571 /** 2572 * skb_tx_timestamp() - Driver hook for transmit timestamping 2573 * 2574 * Ethernet MAC Drivers should call this function in their hard_xmit() 2575 * function immediately before giving the sk_buff to the MAC hardware. 2576 * 2577 * @skb: A socket buffer. 2578 */ 2579 static inline void skb_tx_timestamp(struct sk_buff *skb) 2580 { 2581 skb_clone_tx_timestamp(skb); 2582 sw_tx_timestamp(skb); 2583 } 2584 2585 /** 2586 * skb_complete_wifi_ack - deliver skb with wifi status 2587 * 2588 * @skb: the original outgoing packet 2589 * @acked: ack status 2590 * 2591 */ 2592 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked); 2593 2594 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 2595 extern __sum16 __skb_checksum_complete(struct sk_buff *skb); 2596 2597 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 2598 { 2599 return skb->ip_summed & CHECKSUM_UNNECESSARY; 2600 } 2601 2602 /** 2603 * skb_checksum_complete - Calculate checksum of an entire packet 2604 * @skb: packet to process 2605 * 2606 * This function calculates the checksum over the entire packet plus 2607 * the value of skb->csum. The latter can be used to supply the 2608 * checksum of a pseudo header as used by TCP/UDP. It returns the 2609 * checksum. 2610 * 2611 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 2612 * this function can be used to verify that checksum on received 2613 * packets. In that case the function should return zero if the 2614 * checksum is correct. In particular, this function will return zero 2615 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 2616 * hardware has already verified the correctness of the checksum. 2617 */ 2618 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 2619 { 2620 return skb_csum_unnecessary(skb) ? 2621 0 : __skb_checksum_complete(skb); 2622 } 2623 2624 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2625 extern void nf_conntrack_destroy(struct nf_conntrack *nfct); 2626 static inline void nf_conntrack_put(struct nf_conntrack *nfct) 2627 { 2628 if (nfct && atomic_dec_and_test(&nfct->use)) 2629 nf_conntrack_destroy(nfct); 2630 } 2631 static inline void nf_conntrack_get(struct nf_conntrack *nfct) 2632 { 2633 if (nfct) 2634 atomic_inc(&nfct->use); 2635 } 2636 #endif 2637 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 2638 static inline void nf_conntrack_get_reasm(struct sk_buff *skb) 2639 { 2640 if (skb) 2641 atomic_inc(&skb->users); 2642 } 2643 static inline void nf_conntrack_put_reasm(struct sk_buff *skb) 2644 { 2645 if (skb) 2646 kfree_skb(skb); 2647 } 2648 #endif 2649 #ifdef CONFIG_BRIDGE_NETFILTER 2650 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) 2651 { 2652 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) 2653 kfree(nf_bridge); 2654 } 2655 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) 2656 { 2657 if (nf_bridge) 2658 atomic_inc(&nf_bridge->use); 2659 } 2660 #endif /* CONFIG_BRIDGE_NETFILTER */ 2661 static inline void nf_reset(struct sk_buff *skb) 2662 { 2663 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2664 nf_conntrack_put(skb->nfct); 2665 skb->nfct = NULL; 2666 #endif 2667 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 2668 nf_conntrack_put_reasm(skb->nfct_reasm); 2669 skb->nfct_reasm = NULL; 2670 #endif 2671 #ifdef CONFIG_BRIDGE_NETFILTER 2672 nf_bridge_put(skb->nf_bridge); 2673 skb->nf_bridge = NULL; 2674 #endif 2675 } 2676 2677 /* Note: This doesn't put any conntrack and bridge info in dst. */ 2678 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2679 { 2680 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2681 dst->nfct = src->nfct; 2682 nf_conntrack_get(src->nfct); 2683 dst->nfctinfo = src->nfctinfo; 2684 #endif 2685 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 2686 dst->nfct_reasm = src->nfct_reasm; 2687 nf_conntrack_get_reasm(src->nfct_reasm); 2688 #endif 2689 #ifdef CONFIG_BRIDGE_NETFILTER 2690 dst->nf_bridge = src->nf_bridge; 2691 nf_bridge_get(src->nf_bridge); 2692 #endif 2693 } 2694 2695 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2696 { 2697 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2698 nf_conntrack_put(dst->nfct); 2699 #endif 2700 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 2701 nf_conntrack_put_reasm(dst->nfct_reasm); 2702 #endif 2703 #ifdef CONFIG_BRIDGE_NETFILTER 2704 nf_bridge_put(dst->nf_bridge); 2705 #endif 2706 __nf_copy(dst, src); 2707 } 2708 2709 #ifdef CONFIG_NETWORK_SECMARK 2710 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2711 { 2712 to->secmark = from->secmark; 2713 } 2714 2715 static inline void skb_init_secmark(struct sk_buff *skb) 2716 { 2717 skb->secmark = 0; 2718 } 2719 #else 2720 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2721 { } 2722 2723 static inline void skb_init_secmark(struct sk_buff *skb) 2724 { } 2725 #endif 2726 2727 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 2728 { 2729 skb->queue_mapping = queue_mapping; 2730 } 2731 2732 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 2733 { 2734 return skb->queue_mapping; 2735 } 2736 2737 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 2738 { 2739 to->queue_mapping = from->queue_mapping; 2740 } 2741 2742 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 2743 { 2744 skb->queue_mapping = rx_queue + 1; 2745 } 2746 2747 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 2748 { 2749 return skb->queue_mapping - 1; 2750 } 2751 2752 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 2753 { 2754 return skb->queue_mapping != 0; 2755 } 2756 2757 extern u16 __skb_tx_hash(const struct net_device *dev, 2758 const struct sk_buff *skb, 2759 unsigned int num_tx_queues); 2760 2761 #ifdef CONFIG_XFRM 2762 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 2763 { 2764 return skb->sp; 2765 } 2766 #else 2767 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 2768 { 2769 return NULL; 2770 } 2771 #endif 2772 2773 /* Keeps track of mac header offset relative to skb->head. 2774 * It is useful for TSO of Tunneling protocol. e.g. GRE. 2775 * For non-tunnel skb it points to skb_mac_header() and for 2776 * tunnel skb it points to outer mac header. */ 2777 struct skb_gso_cb { 2778 int mac_offset; 2779 }; 2780 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb) 2781 2782 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb) 2783 { 2784 return (skb_mac_header(inner_skb) - inner_skb->head) - 2785 SKB_GSO_CB(inner_skb)->mac_offset; 2786 } 2787 2788 static inline bool skb_is_gso(const struct sk_buff *skb) 2789 { 2790 return skb_shinfo(skb)->gso_size; 2791 } 2792 2793 static inline bool skb_is_gso_v6(const struct sk_buff *skb) 2794 { 2795 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 2796 } 2797 2798 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); 2799 2800 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 2801 { 2802 /* LRO sets gso_size but not gso_type, whereas if GSO is really 2803 * wanted then gso_type will be set. */ 2804 const struct skb_shared_info *shinfo = skb_shinfo(skb); 2805 2806 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 2807 unlikely(shinfo->gso_type == 0)) { 2808 __skb_warn_lro_forwarding(skb); 2809 return true; 2810 } 2811 return false; 2812 } 2813 2814 static inline void skb_forward_csum(struct sk_buff *skb) 2815 { 2816 /* Unfortunately we don't support this one. Any brave souls? */ 2817 if (skb->ip_summed == CHECKSUM_COMPLETE) 2818 skb->ip_summed = CHECKSUM_NONE; 2819 } 2820 2821 /** 2822 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 2823 * @skb: skb to check 2824 * 2825 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 2826 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 2827 * use this helper, to document places where we make this assertion. 2828 */ 2829 static inline void skb_checksum_none_assert(const struct sk_buff *skb) 2830 { 2831 #ifdef DEBUG 2832 BUG_ON(skb->ip_summed != CHECKSUM_NONE); 2833 #endif 2834 } 2835 2836 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 2837 2838 /** 2839 * skb_head_is_locked - Determine if the skb->head is locked down 2840 * @skb: skb to check 2841 * 2842 * The head on skbs build around a head frag can be removed if they are 2843 * not cloned. This function returns true if the skb head is locked down 2844 * due to either being allocated via kmalloc, or by being a clone with 2845 * multiple references to the head. 2846 */ 2847 static inline bool skb_head_is_locked(const struct sk_buff *skb) 2848 { 2849 return !skb->head_frag || skb_cloned(skb); 2850 } 2851 #endif /* __KERNEL__ */ 2852 #endif /* _LINUX_SKBUFF_H */ 2853