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/cache.h> 22 23 #include <asm/atomic.h> 24 #include <asm/types.h> 25 #include <linux/spinlock.h> 26 #include <linux/net.h> 27 #include <linux/textsearch.h> 28 #include <net/checksum.h> 29 #include <linux/rcupdate.h> 30 #include <linux/dmaengine.h> 31 #include <linux/hrtimer.h> 32 33 /* Don't change this without changing skb_csum_unnecessary! */ 34 #define CHECKSUM_NONE 0 35 #define CHECKSUM_UNNECESSARY 1 36 #define CHECKSUM_COMPLETE 2 37 #define CHECKSUM_PARTIAL 3 38 39 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ 40 ~(SMP_CACHE_BYTES - 1)) 41 #define SKB_WITH_OVERHEAD(X) \ 42 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) 43 #define SKB_MAX_ORDER(X, ORDER) \ 44 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) 45 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) 46 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) 47 48 /* A. Checksumming of received packets by device. 49 * 50 * NONE: device failed to checksum this packet. 51 * skb->csum is undefined. 52 * 53 * UNNECESSARY: device parsed packet and wouldbe verified checksum. 54 * skb->csum is undefined. 55 * It is bad option, but, unfortunately, many of vendors do this. 56 * Apparently with secret goal to sell you new device, when you 57 * will add new protocol to your host. F.e. IPv6. 8) 58 * 59 * COMPLETE: the most generic way. Device supplied checksum of _all_ 60 * the packet as seen by netif_rx in skb->csum. 61 * NOTE: Even if device supports only some protocols, but 62 * is able to produce some skb->csum, it MUST use COMPLETE, 63 * not UNNECESSARY. 64 * 65 * PARTIAL: identical to the case for output below. This may occur 66 * on a packet received directly from another Linux OS, e.g., 67 * a virtualised Linux kernel on the same host. The packet can 68 * be treated in the same way as UNNECESSARY except that on 69 * output (i.e., forwarding) the checksum must be filled in 70 * by the OS or the hardware. 71 * 72 * B. Checksumming on output. 73 * 74 * NONE: skb is checksummed by protocol or csum is not required. 75 * 76 * PARTIAL: device is required to csum packet as seen by hard_start_xmit 77 * from skb->csum_start to the end and to record the checksum 78 * at skb->csum_start + skb->csum_offset. 79 * 80 * Device must show its capabilities in dev->features, set 81 * at device setup time. 82 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum 83 * everything. 84 * NETIF_F_NO_CSUM - loopback or reliable single hop media. 85 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only 86 * TCP/UDP over IPv4. Sigh. Vendors like this 87 * way by an unknown reason. Though, see comment above 88 * about CHECKSUM_UNNECESSARY. 8) 89 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. 90 * 91 * Any questions? No questions, good. --ANK 92 */ 93 94 struct net_device; 95 struct scatterlist; 96 struct pipe_inode_info; 97 98 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 99 struct nf_conntrack { 100 atomic_t use; 101 }; 102 #endif 103 104 #ifdef CONFIG_BRIDGE_NETFILTER 105 struct nf_bridge_info { 106 atomic_t use; 107 struct net_device *physindev; 108 struct net_device *physoutdev; 109 unsigned int mask; 110 unsigned long data[32 / sizeof(unsigned long)]; 111 }; 112 #endif 113 114 struct sk_buff_head { 115 /* These two members must be first. */ 116 struct sk_buff *next; 117 struct sk_buff *prev; 118 119 __u32 qlen; 120 spinlock_t lock; 121 }; 122 123 struct sk_buff; 124 125 /* To allow 64K frame to be packed as single skb without frag_list */ 126 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) 127 128 typedef struct skb_frag_struct skb_frag_t; 129 130 struct skb_frag_struct { 131 struct page *page; 132 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 133 __u32 page_offset; 134 __u32 size; 135 #else 136 __u16 page_offset; 137 __u16 size; 138 #endif 139 }; 140 141 #define HAVE_HW_TIME_STAMP 142 143 /** 144 * struct skb_shared_hwtstamps - hardware time stamps 145 * @hwtstamp: hardware time stamp transformed into duration 146 * since arbitrary point in time 147 * @syststamp: hwtstamp transformed to system time base 148 * 149 * Software time stamps generated by ktime_get_real() are stored in 150 * skb->tstamp. The relation between the different kinds of time 151 * stamps is as follows: 152 * 153 * syststamp and tstamp can be compared against each other in 154 * arbitrary combinations. The accuracy of a 155 * syststamp/tstamp/"syststamp from other device" comparison is 156 * limited by the accuracy of the transformation into system time 157 * base. This depends on the device driver and its underlying 158 * hardware. 159 * 160 * hwtstamps can only be compared against other hwtstamps from 161 * the same device. 162 * 163 * This structure is attached to packets as part of the 164 * &skb_shared_info. Use skb_hwtstamps() to get a pointer. 165 */ 166 struct skb_shared_hwtstamps { 167 ktime_t hwtstamp; 168 ktime_t syststamp; 169 }; 170 171 /* Definitions for tx_flags in struct skb_shared_info */ 172 enum { 173 /* generate hardware time stamp */ 174 SKBTX_HW_TSTAMP = 1 << 0, 175 176 /* generate software time stamp */ 177 SKBTX_SW_TSTAMP = 1 << 1, 178 179 /* device driver is going to provide hardware time stamp */ 180 SKBTX_IN_PROGRESS = 1 << 2, 181 182 /* ensure the originating sk reference is available on driver level */ 183 SKBTX_DRV_NEEDS_SK_REF = 1 << 3, 184 }; 185 186 /* This data is invariant across clones and lives at 187 * the end of the header data, ie. at skb->end. 188 */ 189 struct skb_shared_info { 190 unsigned short nr_frags; 191 unsigned short gso_size; 192 /* Warning: this field is not always filled in (UFO)! */ 193 unsigned short gso_segs; 194 unsigned short gso_type; 195 __be32 ip6_frag_id; 196 __u8 tx_flags; 197 struct sk_buff *frag_list; 198 struct skb_shared_hwtstamps hwtstamps; 199 200 /* 201 * Warning : all fields before dataref are cleared in __alloc_skb() 202 */ 203 atomic_t dataref; 204 205 /* Intermediate layers must ensure that destructor_arg 206 * remains valid until skb destructor */ 207 void * destructor_arg; 208 /* must be last field, see pskb_expand_head() */ 209 skb_frag_t frags[MAX_SKB_FRAGS]; 210 }; 211 212 /* We divide dataref into two halves. The higher 16 bits hold references 213 * to the payload part of skb->data. The lower 16 bits hold references to 214 * the entire skb->data. A clone of a headerless skb holds the length of 215 * the header in skb->hdr_len. 216 * 217 * All users must obey the rule that the skb->data reference count must be 218 * greater than or equal to the payload reference count. 219 * 220 * Holding a reference to the payload part means that the user does not 221 * care about modifications to the header part of skb->data. 222 */ 223 #define SKB_DATAREF_SHIFT 16 224 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) 225 226 227 enum { 228 SKB_FCLONE_UNAVAILABLE, 229 SKB_FCLONE_ORIG, 230 SKB_FCLONE_CLONE, 231 }; 232 233 enum { 234 SKB_GSO_TCPV4 = 1 << 0, 235 SKB_GSO_UDP = 1 << 1, 236 237 /* This indicates the skb is from an untrusted source. */ 238 SKB_GSO_DODGY = 1 << 2, 239 240 /* This indicates the tcp segment has CWR set. */ 241 SKB_GSO_TCP_ECN = 1 << 3, 242 243 SKB_GSO_TCPV6 = 1 << 4, 244 245 SKB_GSO_FCOE = 1 << 5, 246 }; 247 248 #if BITS_PER_LONG > 32 249 #define NET_SKBUFF_DATA_USES_OFFSET 1 250 #endif 251 252 #ifdef NET_SKBUFF_DATA_USES_OFFSET 253 typedef unsigned int sk_buff_data_t; 254 #else 255 typedef unsigned char *sk_buff_data_t; 256 #endif 257 258 /** 259 * struct sk_buff - socket buffer 260 * @next: Next buffer in list 261 * @prev: Previous buffer in list 262 * @sk: Socket we are owned by 263 * @tstamp: Time we arrived 264 * @dev: Device we arrived on/are leaving by 265 * @transport_header: Transport layer header 266 * @network_header: Network layer header 267 * @mac_header: Link layer header 268 * @_skb_refdst: destination entry (with norefcount bit) 269 * @sp: the security path, used for xfrm 270 * @cb: Control buffer. Free for use by every layer. Put private vars here 271 * @len: Length of actual data 272 * @data_len: Data length 273 * @mac_len: Length of link layer header 274 * @hdr_len: writable header length of cloned skb 275 * @csum: Checksum (must include start/offset pair) 276 * @csum_start: Offset from skb->head where checksumming should start 277 * @csum_offset: Offset from csum_start where checksum should be stored 278 * @local_df: allow local fragmentation 279 * @cloned: Head may be cloned (check refcnt to be sure) 280 * @nohdr: Payload reference only, must not modify header 281 * @pkt_type: Packet class 282 * @fclone: skbuff clone status 283 * @ip_summed: Driver fed us an IP checksum 284 * @priority: Packet queueing priority 285 * @users: User count - see {datagram,tcp}.c 286 * @protocol: Packet protocol from driver 287 * @truesize: Buffer size 288 * @head: Head of buffer 289 * @data: Data head pointer 290 * @tail: Tail pointer 291 * @end: End pointer 292 * @destructor: Destruct function 293 * @mark: Generic packet mark 294 * @nfct: Associated connection, if any 295 * @ipvs_property: skbuff is owned by ipvs 296 * @peeked: this packet has been seen already, so stats have been 297 * done for it, don't do them again 298 * @nf_trace: netfilter packet trace flag 299 * @nfctinfo: Relationship of this skb to the connection 300 * @nfct_reasm: netfilter conntrack re-assembly pointer 301 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c 302 * @skb_iif: ifindex of device we arrived on 303 * @rxhash: the packet hash computed on receive 304 * @queue_mapping: Queue mapping for multiqueue devices 305 * @tc_index: Traffic control index 306 * @tc_verd: traffic control verdict 307 * @ndisc_nodetype: router type (from link layer) 308 * @dma_cookie: a cookie to one of several possible DMA operations 309 * done by skb DMA functions 310 * @secmark: security marking 311 * @vlan_tci: vlan tag control information 312 */ 313 314 struct sk_buff { 315 /* These two members must be first. */ 316 struct sk_buff *next; 317 struct sk_buff *prev; 318 319 ktime_t tstamp; 320 321 struct sock *sk; 322 struct net_device *dev; 323 324 /* 325 * This is the control buffer. It is free to use for every 326 * layer. Please put your private variables there. If you 327 * want to keep them across layers you have to do a skb_clone() 328 * first. This is owned by whoever has the skb queued ATM. 329 */ 330 char cb[48] __aligned(8); 331 332 unsigned long _skb_refdst; 333 #ifdef CONFIG_XFRM 334 struct sec_path *sp; 335 #endif 336 unsigned int len, 337 data_len; 338 __u16 mac_len, 339 hdr_len; 340 union { 341 __wsum csum; 342 struct { 343 __u16 csum_start; 344 __u16 csum_offset; 345 }; 346 }; 347 __u32 priority; 348 kmemcheck_bitfield_begin(flags1); 349 __u8 local_df:1, 350 cloned:1, 351 ip_summed:2, 352 nohdr:1, 353 nfctinfo:3; 354 __u8 pkt_type:3, 355 fclone:2, 356 ipvs_property:1, 357 peeked:1, 358 nf_trace:1; 359 kmemcheck_bitfield_end(flags1); 360 __be16 protocol; 361 362 void (*destructor)(struct sk_buff *skb); 363 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 364 struct nf_conntrack *nfct; 365 struct sk_buff *nfct_reasm; 366 #endif 367 #ifdef CONFIG_BRIDGE_NETFILTER 368 struct nf_bridge_info *nf_bridge; 369 #endif 370 371 int skb_iif; 372 #ifdef CONFIG_NET_SCHED 373 __u16 tc_index; /* traffic control index */ 374 #ifdef CONFIG_NET_CLS_ACT 375 __u16 tc_verd; /* traffic control verdict */ 376 #endif 377 #endif 378 379 __u32 rxhash; 380 381 kmemcheck_bitfield_begin(flags2); 382 __u16 queue_mapping:16; 383 #ifdef CONFIG_IPV6_NDISC_NODETYPE 384 __u8 ndisc_nodetype:2, 385 deliver_no_wcard:1; 386 #else 387 __u8 deliver_no_wcard:1; 388 #endif 389 kmemcheck_bitfield_end(flags2); 390 391 /* 0/14 bit hole */ 392 393 #ifdef CONFIG_NET_DMA 394 dma_cookie_t dma_cookie; 395 #endif 396 #ifdef CONFIG_NETWORK_SECMARK 397 __u32 secmark; 398 #endif 399 union { 400 __u32 mark; 401 __u32 dropcount; 402 }; 403 404 __u16 vlan_tci; 405 406 sk_buff_data_t transport_header; 407 sk_buff_data_t network_header; 408 sk_buff_data_t mac_header; 409 /* These elements must be at the end, see alloc_skb() for details. */ 410 sk_buff_data_t tail; 411 sk_buff_data_t end; 412 unsigned char *head, 413 *data; 414 unsigned int truesize; 415 atomic_t users; 416 }; 417 418 #ifdef __KERNEL__ 419 /* 420 * Handling routines are only of interest to the kernel 421 */ 422 #include <linux/slab.h> 423 424 #include <asm/system.h> 425 426 /* 427 * skb might have a dst pointer attached, refcounted or not. 428 * _skb_refdst low order bit is set if refcount was _not_ taken 429 */ 430 #define SKB_DST_NOREF 1UL 431 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) 432 433 /** 434 * skb_dst - returns skb dst_entry 435 * @skb: buffer 436 * 437 * Returns skb dst_entry, regardless of reference taken or not. 438 */ 439 static inline struct dst_entry *skb_dst(const struct sk_buff *skb) 440 { 441 /* If refdst was not refcounted, check we still are in a 442 * rcu_read_lock section 443 */ 444 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && 445 !rcu_read_lock_held() && 446 !rcu_read_lock_bh_held()); 447 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); 448 } 449 450 /** 451 * skb_dst_set - sets skb dst 452 * @skb: buffer 453 * @dst: dst entry 454 * 455 * Sets skb dst, assuming a reference was taken on dst and should 456 * be released by skb_dst_drop() 457 */ 458 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) 459 { 460 skb->_skb_refdst = (unsigned long)dst; 461 } 462 463 /** 464 * skb_dst_set_noref - sets skb dst, without a reference 465 * @skb: buffer 466 * @dst: dst entry 467 * 468 * Sets skb dst, assuming a reference was not taken on dst 469 * skb_dst_drop() should not dst_release() this dst 470 */ 471 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) 472 { 473 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); 474 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; 475 } 476 477 /** 478 * skb_dst_is_noref - Test if skb dst isnt refcounted 479 * @skb: buffer 480 */ 481 static inline bool skb_dst_is_noref(const struct sk_buff *skb) 482 { 483 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); 484 } 485 486 static inline struct rtable *skb_rtable(const struct sk_buff *skb) 487 { 488 return (struct rtable *)skb_dst(skb); 489 } 490 491 extern void kfree_skb(struct sk_buff *skb); 492 extern void consume_skb(struct sk_buff *skb); 493 extern void __kfree_skb(struct sk_buff *skb); 494 extern struct sk_buff *__alloc_skb(unsigned int size, 495 gfp_t priority, int fclone, int node); 496 static inline struct sk_buff *alloc_skb(unsigned int size, 497 gfp_t priority) 498 { 499 return __alloc_skb(size, priority, 0, -1); 500 } 501 502 static inline struct sk_buff *alloc_skb_fclone(unsigned int size, 503 gfp_t priority) 504 { 505 return __alloc_skb(size, priority, 1, -1); 506 } 507 508 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size); 509 510 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); 511 extern struct sk_buff *skb_clone(struct sk_buff *skb, 512 gfp_t priority); 513 extern struct sk_buff *skb_copy(const struct sk_buff *skb, 514 gfp_t priority); 515 extern struct sk_buff *pskb_copy(struct sk_buff *skb, 516 gfp_t gfp_mask); 517 extern int pskb_expand_head(struct sk_buff *skb, 518 int nhead, int ntail, 519 gfp_t gfp_mask); 520 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, 521 unsigned int headroom); 522 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 523 int newheadroom, int newtailroom, 524 gfp_t priority); 525 extern int skb_to_sgvec(struct sk_buff *skb, 526 struct scatterlist *sg, int offset, 527 int len); 528 extern int skb_cow_data(struct sk_buff *skb, int tailbits, 529 struct sk_buff **trailer); 530 extern int skb_pad(struct sk_buff *skb, int pad); 531 #define dev_kfree_skb(a) consume_skb(a) 532 533 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 534 int getfrag(void *from, char *to, int offset, 535 int len,int odd, struct sk_buff *skb), 536 void *from, int length); 537 538 struct skb_seq_state { 539 __u32 lower_offset; 540 __u32 upper_offset; 541 __u32 frag_idx; 542 __u32 stepped_offset; 543 struct sk_buff *root_skb; 544 struct sk_buff *cur_skb; 545 __u8 *frag_data; 546 }; 547 548 extern void skb_prepare_seq_read(struct sk_buff *skb, 549 unsigned int from, unsigned int to, 550 struct skb_seq_state *st); 551 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 552 struct skb_seq_state *st); 553 extern void skb_abort_seq_read(struct skb_seq_state *st); 554 555 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 556 unsigned int to, struct ts_config *config, 557 struct ts_state *state); 558 559 extern __u32 __skb_get_rxhash(struct sk_buff *skb); 560 static inline __u32 skb_get_rxhash(struct sk_buff *skb) 561 { 562 if (!skb->rxhash) 563 skb->rxhash = __skb_get_rxhash(skb); 564 565 return skb->rxhash; 566 } 567 568 #ifdef NET_SKBUFF_DATA_USES_OFFSET 569 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 570 { 571 return skb->head + skb->end; 572 } 573 #else 574 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) 575 { 576 return skb->end; 577 } 578 #endif 579 580 /* Internal */ 581 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) 582 583 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) 584 { 585 return &skb_shinfo(skb)->hwtstamps; 586 } 587 588 /** 589 * skb_queue_empty - check if a queue is empty 590 * @list: queue head 591 * 592 * Returns true if the queue is empty, false otherwise. 593 */ 594 static inline int skb_queue_empty(const struct sk_buff_head *list) 595 { 596 return list->next == (struct sk_buff *)list; 597 } 598 599 /** 600 * skb_queue_is_last - check if skb is the last entry in the queue 601 * @list: queue head 602 * @skb: buffer 603 * 604 * Returns true if @skb is the last buffer on the list. 605 */ 606 static inline bool skb_queue_is_last(const struct sk_buff_head *list, 607 const struct sk_buff *skb) 608 { 609 return skb->next == (struct sk_buff *)list; 610 } 611 612 /** 613 * skb_queue_is_first - check if skb is the first entry in the queue 614 * @list: queue head 615 * @skb: buffer 616 * 617 * Returns true if @skb is the first buffer on the list. 618 */ 619 static inline bool skb_queue_is_first(const struct sk_buff_head *list, 620 const struct sk_buff *skb) 621 { 622 return skb->prev == (struct sk_buff *)list; 623 } 624 625 /** 626 * skb_queue_next - return the next packet in the queue 627 * @list: queue head 628 * @skb: current buffer 629 * 630 * Return the next packet in @list after @skb. It is only valid to 631 * call this if skb_queue_is_last() evaluates to false. 632 */ 633 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, 634 const struct sk_buff *skb) 635 { 636 /* This BUG_ON may seem severe, but if we just return then we 637 * are going to dereference garbage. 638 */ 639 BUG_ON(skb_queue_is_last(list, skb)); 640 return skb->next; 641 } 642 643 /** 644 * skb_queue_prev - return the prev packet in the queue 645 * @list: queue head 646 * @skb: current buffer 647 * 648 * Return the prev packet in @list before @skb. It is only valid to 649 * call this if skb_queue_is_first() evaluates to false. 650 */ 651 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, 652 const struct sk_buff *skb) 653 { 654 /* This BUG_ON may seem severe, but if we just return then we 655 * are going to dereference garbage. 656 */ 657 BUG_ON(skb_queue_is_first(list, skb)); 658 return skb->prev; 659 } 660 661 /** 662 * skb_get - reference buffer 663 * @skb: buffer to reference 664 * 665 * Makes another reference to a socket buffer and returns a pointer 666 * to the buffer. 667 */ 668 static inline struct sk_buff *skb_get(struct sk_buff *skb) 669 { 670 atomic_inc(&skb->users); 671 return skb; 672 } 673 674 /* 675 * If users == 1, we are the only owner and are can avoid redundant 676 * atomic change. 677 */ 678 679 /** 680 * skb_cloned - is the buffer a clone 681 * @skb: buffer to check 682 * 683 * Returns true if the buffer was generated with skb_clone() and is 684 * one of multiple shared copies of the buffer. Cloned buffers are 685 * shared data so must not be written to under normal circumstances. 686 */ 687 static inline int skb_cloned(const struct sk_buff *skb) 688 { 689 return skb->cloned && 690 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; 691 } 692 693 /** 694 * skb_header_cloned - is the header a clone 695 * @skb: buffer to check 696 * 697 * Returns true if modifying the header part of the buffer requires 698 * the data to be copied. 699 */ 700 static inline int skb_header_cloned(const struct sk_buff *skb) 701 { 702 int dataref; 703 704 if (!skb->cloned) 705 return 0; 706 707 dataref = atomic_read(&skb_shinfo(skb)->dataref); 708 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); 709 return dataref != 1; 710 } 711 712 /** 713 * skb_header_release - release reference to header 714 * @skb: buffer to operate on 715 * 716 * Drop a reference to the header part of the buffer. This is done 717 * by acquiring a payload reference. You must not read from the header 718 * part of skb->data after this. 719 */ 720 static inline void skb_header_release(struct sk_buff *skb) 721 { 722 BUG_ON(skb->nohdr); 723 skb->nohdr = 1; 724 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); 725 } 726 727 /** 728 * skb_shared - is the buffer shared 729 * @skb: buffer to check 730 * 731 * Returns true if more than one person has a reference to this 732 * buffer. 733 */ 734 static inline int skb_shared(const struct sk_buff *skb) 735 { 736 return atomic_read(&skb->users) != 1; 737 } 738 739 /** 740 * skb_share_check - check if buffer is shared and if so clone it 741 * @skb: buffer to check 742 * @pri: priority for memory allocation 743 * 744 * If the buffer is shared the buffer is cloned and the old copy 745 * drops a reference. A new clone with a single reference is returned. 746 * If the buffer is not shared the original buffer is returned. When 747 * being called from interrupt status or with spinlocks held pri must 748 * be GFP_ATOMIC. 749 * 750 * NULL is returned on a memory allocation failure. 751 */ 752 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, 753 gfp_t pri) 754 { 755 might_sleep_if(pri & __GFP_WAIT); 756 if (skb_shared(skb)) { 757 struct sk_buff *nskb = skb_clone(skb, pri); 758 kfree_skb(skb); 759 skb = nskb; 760 } 761 return skb; 762 } 763 764 /* 765 * Copy shared buffers into a new sk_buff. We effectively do COW on 766 * packets to handle cases where we have a local reader and forward 767 * and a couple of other messy ones. The normal one is tcpdumping 768 * a packet thats being forwarded. 769 */ 770 771 /** 772 * skb_unshare - make a copy of a shared buffer 773 * @skb: buffer to check 774 * @pri: priority for memory allocation 775 * 776 * If the socket buffer is a clone then this function creates a new 777 * copy of the data, drops a reference count on the old copy and returns 778 * the new copy with the reference count at 1. If the buffer is not a clone 779 * the original buffer is returned. When called with a spinlock held or 780 * from interrupt state @pri must be %GFP_ATOMIC 781 * 782 * %NULL is returned on a memory allocation failure. 783 */ 784 static inline struct sk_buff *skb_unshare(struct sk_buff *skb, 785 gfp_t pri) 786 { 787 might_sleep_if(pri & __GFP_WAIT); 788 if (skb_cloned(skb)) { 789 struct sk_buff *nskb = skb_copy(skb, pri); 790 kfree_skb(skb); /* Free our shared copy */ 791 skb = nskb; 792 } 793 return skb; 794 } 795 796 /** 797 * skb_peek - peek at the head of an &sk_buff_head 798 * @list_: list to peek at 799 * 800 * Peek an &sk_buff. Unlike most other operations you _MUST_ 801 * be careful with this one. A peek leaves the buffer on the 802 * list and someone else may run off with it. You must hold 803 * the appropriate locks or have a private queue to do this. 804 * 805 * Returns %NULL for an empty list or a pointer to the head element. 806 * The reference count is not incremented and the reference is therefore 807 * volatile. Use with caution. 808 */ 809 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) 810 { 811 struct sk_buff *list = ((struct sk_buff *)list_)->next; 812 if (list == (struct sk_buff *)list_) 813 list = NULL; 814 return list; 815 } 816 817 /** 818 * skb_peek_tail - peek at the tail of an &sk_buff_head 819 * @list_: list to peek at 820 * 821 * Peek an &sk_buff. Unlike most other operations you _MUST_ 822 * be careful with this one. A peek leaves the buffer on the 823 * list and someone else may run off with it. You must hold 824 * the appropriate locks or have a private queue to do this. 825 * 826 * Returns %NULL for an empty list or a pointer to the tail element. 827 * The reference count is not incremented and the reference is therefore 828 * volatile. Use with caution. 829 */ 830 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) 831 { 832 struct sk_buff *list = ((struct sk_buff *)list_)->prev; 833 if (list == (struct sk_buff *)list_) 834 list = NULL; 835 return list; 836 } 837 838 /** 839 * skb_queue_len - get queue length 840 * @list_: list to measure 841 * 842 * Return the length of an &sk_buff queue. 843 */ 844 static inline __u32 skb_queue_len(const struct sk_buff_head *list_) 845 { 846 return list_->qlen; 847 } 848 849 /** 850 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head 851 * @list: queue to initialize 852 * 853 * This initializes only the list and queue length aspects of 854 * an sk_buff_head object. This allows to initialize the list 855 * aspects of an sk_buff_head without reinitializing things like 856 * the spinlock. It can also be used for on-stack sk_buff_head 857 * objects where the spinlock is known to not be used. 858 */ 859 static inline void __skb_queue_head_init(struct sk_buff_head *list) 860 { 861 list->prev = list->next = (struct sk_buff *)list; 862 list->qlen = 0; 863 } 864 865 /* 866 * This function creates a split out lock class for each invocation; 867 * this is needed for now since a whole lot of users of the skb-queue 868 * infrastructure in drivers have different locking usage (in hardirq) 869 * than the networking core (in softirq only). In the long run either the 870 * network layer or drivers should need annotation to consolidate the 871 * main types of usage into 3 classes. 872 */ 873 static inline void skb_queue_head_init(struct sk_buff_head *list) 874 { 875 spin_lock_init(&list->lock); 876 __skb_queue_head_init(list); 877 } 878 879 static inline void skb_queue_head_init_class(struct sk_buff_head *list, 880 struct lock_class_key *class) 881 { 882 skb_queue_head_init(list); 883 lockdep_set_class(&list->lock, class); 884 } 885 886 /* 887 * Insert an sk_buff on a list. 888 * 889 * The "__skb_xxxx()" functions are the non-atomic ones that 890 * can only be called with interrupts disabled. 891 */ 892 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); 893 static inline void __skb_insert(struct sk_buff *newsk, 894 struct sk_buff *prev, struct sk_buff *next, 895 struct sk_buff_head *list) 896 { 897 newsk->next = next; 898 newsk->prev = prev; 899 next->prev = prev->next = newsk; 900 list->qlen++; 901 } 902 903 static inline void __skb_queue_splice(const struct sk_buff_head *list, 904 struct sk_buff *prev, 905 struct sk_buff *next) 906 { 907 struct sk_buff *first = list->next; 908 struct sk_buff *last = list->prev; 909 910 first->prev = prev; 911 prev->next = first; 912 913 last->next = next; 914 next->prev = last; 915 } 916 917 /** 918 * skb_queue_splice - join two skb lists, this is designed for stacks 919 * @list: the new list to add 920 * @head: the place to add it in the first list 921 */ 922 static inline void skb_queue_splice(const struct sk_buff_head *list, 923 struct sk_buff_head *head) 924 { 925 if (!skb_queue_empty(list)) { 926 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 927 head->qlen += list->qlen; 928 } 929 } 930 931 /** 932 * skb_queue_splice - join two skb lists and reinitialise the emptied list 933 * @list: the new list to add 934 * @head: the place to add it in the first list 935 * 936 * The list at @list is reinitialised 937 */ 938 static inline void skb_queue_splice_init(struct sk_buff_head *list, 939 struct sk_buff_head *head) 940 { 941 if (!skb_queue_empty(list)) { 942 __skb_queue_splice(list, (struct sk_buff *) head, head->next); 943 head->qlen += list->qlen; 944 __skb_queue_head_init(list); 945 } 946 } 947 948 /** 949 * skb_queue_splice_tail - join two skb lists, each list being a queue 950 * @list: the new list to add 951 * @head: the place to add it in the first list 952 */ 953 static inline void skb_queue_splice_tail(const struct sk_buff_head *list, 954 struct sk_buff_head *head) 955 { 956 if (!skb_queue_empty(list)) { 957 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 958 head->qlen += list->qlen; 959 } 960 } 961 962 /** 963 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list 964 * @list: the new list to add 965 * @head: the place to add it in the first list 966 * 967 * Each of the lists is a queue. 968 * The list at @list is reinitialised 969 */ 970 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, 971 struct sk_buff_head *head) 972 { 973 if (!skb_queue_empty(list)) { 974 __skb_queue_splice(list, head->prev, (struct sk_buff *) head); 975 head->qlen += list->qlen; 976 __skb_queue_head_init(list); 977 } 978 } 979 980 /** 981 * __skb_queue_after - queue a buffer at the list head 982 * @list: list to use 983 * @prev: place after this buffer 984 * @newsk: buffer to queue 985 * 986 * Queue a buffer int the middle of a list. This function takes no locks 987 * and you must therefore hold required locks before calling it. 988 * 989 * A buffer cannot be placed on two lists at the same time. 990 */ 991 static inline void __skb_queue_after(struct sk_buff_head *list, 992 struct sk_buff *prev, 993 struct sk_buff *newsk) 994 { 995 __skb_insert(newsk, prev, prev->next, list); 996 } 997 998 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk, 999 struct sk_buff_head *list); 1000 1001 static inline void __skb_queue_before(struct sk_buff_head *list, 1002 struct sk_buff *next, 1003 struct sk_buff *newsk) 1004 { 1005 __skb_insert(newsk, next->prev, next, list); 1006 } 1007 1008 /** 1009 * __skb_queue_head - queue a buffer at the list head 1010 * @list: list to use 1011 * @newsk: buffer to queue 1012 * 1013 * Queue a buffer at the start of a list. This function takes no locks 1014 * and you must therefore hold required locks before calling it. 1015 * 1016 * A buffer cannot be placed on two lists at the same time. 1017 */ 1018 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); 1019 static inline void __skb_queue_head(struct sk_buff_head *list, 1020 struct sk_buff *newsk) 1021 { 1022 __skb_queue_after(list, (struct sk_buff *)list, newsk); 1023 } 1024 1025 /** 1026 * __skb_queue_tail - queue a buffer at the list tail 1027 * @list: list to use 1028 * @newsk: buffer to queue 1029 * 1030 * Queue a buffer at the end of a list. This function takes no locks 1031 * and you must therefore hold required locks before calling it. 1032 * 1033 * A buffer cannot be placed on two lists at the same time. 1034 */ 1035 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); 1036 static inline void __skb_queue_tail(struct sk_buff_head *list, 1037 struct sk_buff *newsk) 1038 { 1039 __skb_queue_before(list, (struct sk_buff *)list, newsk); 1040 } 1041 1042 /* 1043 * remove sk_buff from list. _Must_ be called atomically, and with 1044 * the list known.. 1045 */ 1046 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); 1047 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 1048 { 1049 struct sk_buff *next, *prev; 1050 1051 list->qlen--; 1052 next = skb->next; 1053 prev = skb->prev; 1054 skb->next = skb->prev = NULL; 1055 next->prev = prev; 1056 prev->next = next; 1057 } 1058 1059 /** 1060 * __skb_dequeue - remove from the head of the queue 1061 * @list: list to dequeue from 1062 * 1063 * Remove the head of the list. This function does not take any locks 1064 * so must be used with appropriate locks held only. The head item is 1065 * returned or %NULL if the list is empty. 1066 */ 1067 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); 1068 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) 1069 { 1070 struct sk_buff *skb = skb_peek(list); 1071 if (skb) 1072 __skb_unlink(skb, list); 1073 return skb; 1074 } 1075 1076 /** 1077 * __skb_dequeue_tail - remove from the tail of the queue 1078 * @list: list to dequeue from 1079 * 1080 * Remove the tail of the list. This function does not take any locks 1081 * so must be used with appropriate locks held only. The tail item is 1082 * returned or %NULL if the list is empty. 1083 */ 1084 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); 1085 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) 1086 { 1087 struct sk_buff *skb = skb_peek_tail(list); 1088 if (skb) 1089 __skb_unlink(skb, list); 1090 return skb; 1091 } 1092 1093 1094 static inline int skb_is_nonlinear(const struct sk_buff *skb) 1095 { 1096 return skb->data_len; 1097 } 1098 1099 static inline unsigned int skb_headlen(const struct sk_buff *skb) 1100 { 1101 return skb->len - skb->data_len; 1102 } 1103 1104 static inline int skb_pagelen(const struct sk_buff *skb) 1105 { 1106 int i, len = 0; 1107 1108 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) 1109 len += skb_shinfo(skb)->frags[i].size; 1110 return len + skb_headlen(skb); 1111 } 1112 1113 static inline void skb_fill_page_desc(struct sk_buff *skb, int i, 1114 struct page *page, int off, int size) 1115 { 1116 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 1117 1118 frag->page = page; 1119 frag->page_offset = off; 1120 frag->size = size; 1121 skb_shinfo(skb)->nr_frags = i + 1; 1122 } 1123 1124 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, 1125 int off, int size); 1126 1127 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) 1128 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) 1129 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) 1130 1131 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1132 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1133 { 1134 return skb->head + skb->tail; 1135 } 1136 1137 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1138 { 1139 skb->tail = skb->data - skb->head; 1140 } 1141 1142 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1143 { 1144 skb_reset_tail_pointer(skb); 1145 skb->tail += offset; 1146 } 1147 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1148 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) 1149 { 1150 return skb->tail; 1151 } 1152 1153 static inline void skb_reset_tail_pointer(struct sk_buff *skb) 1154 { 1155 skb->tail = skb->data; 1156 } 1157 1158 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) 1159 { 1160 skb->tail = skb->data + offset; 1161 } 1162 1163 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1164 1165 /* 1166 * Add data to an sk_buff 1167 */ 1168 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len); 1169 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) 1170 { 1171 unsigned char *tmp = skb_tail_pointer(skb); 1172 SKB_LINEAR_ASSERT(skb); 1173 skb->tail += len; 1174 skb->len += len; 1175 return tmp; 1176 } 1177 1178 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len); 1179 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) 1180 { 1181 skb->data -= len; 1182 skb->len += len; 1183 return skb->data; 1184 } 1185 1186 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); 1187 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) 1188 { 1189 skb->len -= len; 1190 BUG_ON(skb->len < skb->data_len); 1191 return skb->data += len; 1192 } 1193 1194 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) 1195 { 1196 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); 1197 } 1198 1199 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); 1200 1201 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) 1202 { 1203 if (len > skb_headlen(skb) && 1204 !__pskb_pull_tail(skb, len - skb_headlen(skb))) 1205 return NULL; 1206 skb->len -= len; 1207 return skb->data += len; 1208 } 1209 1210 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) 1211 { 1212 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); 1213 } 1214 1215 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) 1216 { 1217 if (likely(len <= skb_headlen(skb))) 1218 return 1; 1219 if (unlikely(len > skb->len)) 1220 return 0; 1221 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; 1222 } 1223 1224 /** 1225 * skb_headroom - bytes at buffer head 1226 * @skb: buffer to check 1227 * 1228 * Return the number of bytes of free space at the head of an &sk_buff. 1229 */ 1230 static inline unsigned int skb_headroom(const struct sk_buff *skb) 1231 { 1232 return skb->data - skb->head; 1233 } 1234 1235 /** 1236 * skb_tailroom - bytes at buffer end 1237 * @skb: buffer to check 1238 * 1239 * Return the number of bytes of free space at the tail of an sk_buff 1240 */ 1241 static inline int skb_tailroom(const struct sk_buff *skb) 1242 { 1243 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; 1244 } 1245 1246 /** 1247 * skb_reserve - adjust headroom 1248 * @skb: buffer to alter 1249 * @len: bytes to move 1250 * 1251 * Increase the headroom of an empty &sk_buff by reducing the tail 1252 * room. This is only allowed for an empty buffer. 1253 */ 1254 static inline void skb_reserve(struct sk_buff *skb, int len) 1255 { 1256 skb->data += len; 1257 skb->tail += len; 1258 } 1259 1260 #ifdef NET_SKBUFF_DATA_USES_OFFSET 1261 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1262 { 1263 return skb->head + skb->transport_header; 1264 } 1265 1266 static inline void skb_reset_transport_header(struct sk_buff *skb) 1267 { 1268 skb->transport_header = skb->data - skb->head; 1269 } 1270 1271 static inline void skb_set_transport_header(struct sk_buff *skb, 1272 const int offset) 1273 { 1274 skb_reset_transport_header(skb); 1275 skb->transport_header += offset; 1276 } 1277 1278 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 1279 { 1280 return skb->head + skb->network_header; 1281 } 1282 1283 static inline void skb_reset_network_header(struct sk_buff *skb) 1284 { 1285 skb->network_header = skb->data - skb->head; 1286 } 1287 1288 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 1289 { 1290 skb_reset_network_header(skb); 1291 skb->network_header += offset; 1292 } 1293 1294 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 1295 { 1296 return skb->head + skb->mac_header; 1297 } 1298 1299 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 1300 { 1301 return skb->mac_header != ~0U; 1302 } 1303 1304 static inline void skb_reset_mac_header(struct sk_buff *skb) 1305 { 1306 skb->mac_header = skb->data - skb->head; 1307 } 1308 1309 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 1310 { 1311 skb_reset_mac_header(skb); 1312 skb->mac_header += offset; 1313 } 1314 1315 #else /* NET_SKBUFF_DATA_USES_OFFSET */ 1316 1317 static inline unsigned char *skb_transport_header(const struct sk_buff *skb) 1318 { 1319 return skb->transport_header; 1320 } 1321 1322 static inline void skb_reset_transport_header(struct sk_buff *skb) 1323 { 1324 skb->transport_header = skb->data; 1325 } 1326 1327 static inline void skb_set_transport_header(struct sk_buff *skb, 1328 const int offset) 1329 { 1330 skb->transport_header = skb->data + offset; 1331 } 1332 1333 static inline unsigned char *skb_network_header(const struct sk_buff *skb) 1334 { 1335 return skb->network_header; 1336 } 1337 1338 static inline void skb_reset_network_header(struct sk_buff *skb) 1339 { 1340 skb->network_header = skb->data; 1341 } 1342 1343 static inline void skb_set_network_header(struct sk_buff *skb, const int offset) 1344 { 1345 skb->network_header = skb->data + offset; 1346 } 1347 1348 static inline unsigned char *skb_mac_header(const struct sk_buff *skb) 1349 { 1350 return skb->mac_header; 1351 } 1352 1353 static inline int skb_mac_header_was_set(const struct sk_buff *skb) 1354 { 1355 return skb->mac_header != NULL; 1356 } 1357 1358 static inline void skb_reset_mac_header(struct sk_buff *skb) 1359 { 1360 skb->mac_header = skb->data; 1361 } 1362 1363 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) 1364 { 1365 skb->mac_header = skb->data + offset; 1366 } 1367 #endif /* NET_SKBUFF_DATA_USES_OFFSET */ 1368 1369 static inline int skb_transport_offset(const struct sk_buff *skb) 1370 { 1371 return skb_transport_header(skb) - skb->data; 1372 } 1373 1374 static inline u32 skb_network_header_len(const struct sk_buff *skb) 1375 { 1376 return skb->transport_header - skb->network_header; 1377 } 1378 1379 static inline int skb_network_offset(const struct sk_buff *skb) 1380 { 1381 return skb_network_header(skb) - skb->data; 1382 } 1383 1384 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) 1385 { 1386 return pskb_may_pull(skb, skb_network_offset(skb) + len); 1387 } 1388 1389 /* 1390 * CPUs often take a performance hit when accessing unaligned memory 1391 * locations. The actual performance hit varies, it can be small if the 1392 * hardware handles it or large if we have to take an exception and fix it 1393 * in software. 1394 * 1395 * Since an ethernet header is 14 bytes network drivers often end up with 1396 * the IP header at an unaligned offset. The IP header can be aligned by 1397 * shifting the start of the packet by 2 bytes. Drivers should do this 1398 * with: 1399 * 1400 * skb_reserve(skb, NET_IP_ALIGN); 1401 * 1402 * The downside to this alignment of the IP header is that the DMA is now 1403 * unaligned. On some architectures the cost of an unaligned DMA is high 1404 * and this cost outweighs the gains made by aligning the IP header. 1405 * 1406 * Since this trade off varies between architectures, we allow NET_IP_ALIGN 1407 * to be overridden. 1408 */ 1409 #ifndef NET_IP_ALIGN 1410 #define NET_IP_ALIGN 2 1411 #endif 1412 1413 /* 1414 * The networking layer reserves some headroom in skb data (via 1415 * dev_alloc_skb). This is used to avoid having to reallocate skb data when 1416 * the header has to grow. In the default case, if the header has to grow 1417 * 32 bytes or less we avoid the reallocation. 1418 * 1419 * Unfortunately this headroom changes the DMA alignment of the resulting 1420 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive 1421 * on some architectures. An architecture can override this value, 1422 * perhaps setting it to a cacheline in size (since that will maintain 1423 * cacheline alignment of the DMA). It must be a power of 2. 1424 * 1425 * Various parts of the networking layer expect at least 32 bytes of 1426 * headroom, you should not reduce this. 1427 * 1428 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) 1429 * to reduce average number of cache lines per packet. 1430 * get_rps_cpus() for example only access one 64 bytes aligned block : 1431 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) 1432 */ 1433 #ifndef NET_SKB_PAD 1434 #define NET_SKB_PAD max(32, L1_CACHE_BYTES) 1435 #endif 1436 1437 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); 1438 1439 static inline void __skb_trim(struct sk_buff *skb, unsigned int len) 1440 { 1441 if (unlikely(skb->data_len)) { 1442 WARN_ON(1); 1443 return; 1444 } 1445 skb->len = len; 1446 skb_set_tail_pointer(skb, len); 1447 } 1448 1449 extern void skb_trim(struct sk_buff *skb, unsigned int len); 1450 1451 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) 1452 { 1453 if (skb->data_len) 1454 return ___pskb_trim(skb, len); 1455 __skb_trim(skb, len); 1456 return 0; 1457 } 1458 1459 static inline int pskb_trim(struct sk_buff *skb, unsigned int len) 1460 { 1461 return (len < skb->len) ? __pskb_trim(skb, len) : 0; 1462 } 1463 1464 /** 1465 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer 1466 * @skb: buffer to alter 1467 * @len: new length 1468 * 1469 * This is identical to pskb_trim except that the caller knows that 1470 * the skb is not cloned so we should never get an error due to out- 1471 * of-memory. 1472 */ 1473 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) 1474 { 1475 int err = pskb_trim(skb, len); 1476 BUG_ON(err); 1477 } 1478 1479 /** 1480 * skb_orphan - orphan a buffer 1481 * @skb: buffer to orphan 1482 * 1483 * If a buffer currently has an owner then we call the owner's 1484 * destructor function and make the @skb unowned. The buffer continues 1485 * to exist but is no longer charged to its former owner. 1486 */ 1487 static inline void skb_orphan(struct sk_buff *skb) 1488 { 1489 if (skb->destructor) 1490 skb->destructor(skb); 1491 skb->destructor = NULL; 1492 skb->sk = NULL; 1493 } 1494 1495 /** 1496 * __skb_queue_purge - empty a list 1497 * @list: list to empty 1498 * 1499 * Delete all buffers on an &sk_buff list. Each buffer is removed from 1500 * the list and one reference dropped. This function does not take the 1501 * list lock and the caller must hold the relevant locks to use it. 1502 */ 1503 extern void skb_queue_purge(struct sk_buff_head *list); 1504 static inline void __skb_queue_purge(struct sk_buff_head *list) 1505 { 1506 struct sk_buff *skb; 1507 while ((skb = __skb_dequeue(list)) != NULL) 1508 kfree_skb(skb); 1509 } 1510 1511 /** 1512 * __dev_alloc_skb - allocate an skbuff for receiving 1513 * @length: length to allocate 1514 * @gfp_mask: get_free_pages mask, passed to alloc_skb 1515 * 1516 * Allocate a new &sk_buff and assign it a usage count of one. The 1517 * buffer has unspecified headroom built in. Users should allocate 1518 * the headroom they think they need without accounting for the 1519 * built in space. The built in space is used for optimisations. 1520 * 1521 * %NULL is returned if there is no free memory. 1522 */ 1523 static inline struct sk_buff *__dev_alloc_skb(unsigned int length, 1524 gfp_t gfp_mask) 1525 { 1526 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); 1527 if (likely(skb)) 1528 skb_reserve(skb, NET_SKB_PAD); 1529 return skb; 1530 } 1531 1532 extern struct sk_buff *dev_alloc_skb(unsigned int length); 1533 1534 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, 1535 unsigned int length, gfp_t gfp_mask); 1536 1537 /** 1538 * netdev_alloc_skb - allocate an skbuff for rx on a specific device 1539 * @dev: network device to receive on 1540 * @length: length to allocate 1541 * 1542 * Allocate a new &sk_buff and assign it a usage count of one. The 1543 * buffer has unspecified headroom built in. Users should allocate 1544 * the headroom they think they need without accounting for the 1545 * built in space. The built in space is used for optimisations. 1546 * 1547 * %NULL is returned if there is no free memory. Although this function 1548 * allocates memory it can be called from an interrupt. 1549 */ 1550 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, 1551 unsigned int length) 1552 { 1553 return __netdev_alloc_skb(dev, length, GFP_ATOMIC); 1554 } 1555 1556 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, 1557 unsigned int length) 1558 { 1559 struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN); 1560 1561 if (NET_IP_ALIGN && skb) 1562 skb_reserve(skb, NET_IP_ALIGN); 1563 return skb; 1564 } 1565 1566 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask); 1567 1568 /** 1569 * netdev_alloc_page - allocate a page for ps-rx on a specific device 1570 * @dev: network device to receive on 1571 * 1572 * Allocate a new page node local to the specified device. 1573 * 1574 * %NULL is returned if there is no free memory. 1575 */ 1576 static inline struct page *netdev_alloc_page(struct net_device *dev) 1577 { 1578 return __netdev_alloc_page(dev, GFP_ATOMIC); 1579 } 1580 1581 static inline void netdev_free_page(struct net_device *dev, struct page *page) 1582 { 1583 __free_page(page); 1584 } 1585 1586 /** 1587 * skb_clone_writable - is the header of a clone writable 1588 * @skb: buffer to check 1589 * @len: length up to which to write 1590 * 1591 * Returns true if modifying the header part of the cloned buffer 1592 * does not requires the data to be copied. 1593 */ 1594 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len) 1595 { 1596 return !skb_header_cloned(skb) && 1597 skb_headroom(skb) + len <= skb->hdr_len; 1598 } 1599 1600 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, 1601 int cloned) 1602 { 1603 int delta = 0; 1604 1605 if (headroom < NET_SKB_PAD) 1606 headroom = NET_SKB_PAD; 1607 if (headroom > skb_headroom(skb)) 1608 delta = headroom - skb_headroom(skb); 1609 1610 if (delta || cloned) 1611 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, 1612 GFP_ATOMIC); 1613 return 0; 1614 } 1615 1616 /** 1617 * skb_cow - copy header of skb when it is required 1618 * @skb: buffer to cow 1619 * @headroom: needed headroom 1620 * 1621 * If the skb passed lacks sufficient headroom or its data part 1622 * is shared, data is reallocated. If reallocation fails, an error 1623 * is returned and original skb is not changed. 1624 * 1625 * The result is skb with writable area skb->head...skb->tail 1626 * and at least @headroom of space at head. 1627 */ 1628 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) 1629 { 1630 return __skb_cow(skb, headroom, skb_cloned(skb)); 1631 } 1632 1633 /** 1634 * skb_cow_head - skb_cow but only making the head writable 1635 * @skb: buffer to cow 1636 * @headroom: needed headroom 1637 * 1638 * This function is identical to skb_cow except that we replace the 1639 * skb_cloned check by skb_header_cloned. It should be used when 1640 * you only need to push on some header and do not need to modify 1641 * the data. 1642 */ 1643 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) 1644 { 1645 return __skb_cow(skb, headroom, skb_header_cloned(skb)); 1646 } 1647 1648 /** 1649 * skb_padto - pad an skbuff up to a minimal size 1650 * @skb: buffer to pad 1651 * @len: minimal length 1652 * 1653 * Pads up a buffer to ensure the trailing bytes exist and are 1654 * blanked. If the buffer already contains sufficient data it 1655 * is untouched. Otherwise it is extended. Returns zero on 1656 * success. The skb is freed on error. 1657 */ 1658 1659 static inline int skb_padto(struct sk_buff *skb, unsigned int len) 1660 { 1661 unsigned int size = skb->len; 1662 if (likely(size >= len)) 1663 return 0; 1664 return skb_pad(skb, len - size); 1665 } 1666 1667 static inline int skb_add_data(struct sk_buff *skb, 1668 char __user *from, int copy) 1669 { 1670 const int off = skb->len; 1671 1672 if (skb->ip_summed == CHECKSUM_NONE) { 1673 int err = 0; 1674 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), 1675 copy, 0, &err); 1676 if (!err) { 1677 skb->csum = csum_block_add(skb->csum, csum, off); 1678 return 0; 1679 } 1680 } else if (!copy_from_user(skb_put(skb, copy), from, copy)) 1681 return 0; 1682 1683 __skb_trim(skb, off); 1684 return -EFAULT; 1685 } 1686 1687 static inline int skb_can_coalesce(struct sk_buff *skb, int i, 1688 struct page *page, int off) 1689 { 1690 if (i) { 1691 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; 1692 1693 return page == frag->page && 1694 off == frag->page_offset + frag->size; 1695 } 1696 return 0; 1697 } 1698 1699 static inline int __skb_linearize(struct sk_buff *skb) 1700 { 1701 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; 1702 } 1703 1704 /** 1705 * skb_linearize - convert paged skb to linear one 1706 * @skb: buffer to linarize 1707 * 1708 * If there is no free memory -ENOMEM is returned, otherwise zero 1709 * is returned and the old skb data released. 1710 */ 1711 static inline int skb_linearize(struct sk_buff *skb) 1712 { 1713 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; 1714 } 1715 1716 /** 1717 * skb_linearize_cow - make sure skb is linear and writable 1718 * @skb: buffer to process 1719 * 1720 * If there is no free memory -ENOMEM is returned, otherwise zero 1721 * is returned and the old skb data released. 1722 */ 1723 static inline int skb_linearize_cow(struct sk_buff *skb) 1724 { 1725 return skb_is_nonlinear(skb) || skb_cloned(skb) ? 1726 __skb_linearize(skb) : 0; 1727 } 1728 1729 /** 1730 * skb_postpull_rcsum - update checksum for received skb after pull 1731 * @skb: buffer to update 1732 * @start: start of data before pull 1733 * @len: length of data pulled 1734 * 1735 * After doing a pull on a received packet, you need to call this to 1736 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to 1737 * CHECKSUM_NONE so that it can be recomputed from scratch. 1738 */ 1739 1740 static inline void skb_postpull_rcsum(struct sk_buff *skb, 1741 const void *start, unsigned int len) 1742 { 1743 if (skb->ip_summed == CHECKSUM_COMPLETE) 1744 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); 1745 } 1746 1747 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); 1748 1749 /** 1750 * pskb_trim_rcsum - trim received skb and update checksum 1751 * @skb: buffer to trim 1752 * @len: new length 1753 * 1754 * This is exactly the same as pskb_trim except that it ensures the 1755 * checksum of received packets are still valid after the operation. 1756 */ 1757 1758 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) 1759 { 1760 if (likely(len >= skb->len)) 1761 return 0; 1762 if (skb->ip_summed == CHECKSUM_COMPLETE) 1763 skb->ip_summed = CHECKSUM_NONE; 1764 return __pskb_trim(skb, len); 1765 } 1766 1767 #define skb_queue_walk(queue, skb) \ 1768 for (skb = (queue)->next; \ 1769 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ 1770 skb = skb->next) 1771 1772 #define skb_queue_walk_safe(queue, skb, tmp) \ 1773 for (skb = (queue)->next, tmp = skb->next; \ 1774 skb != (struct sk_buff *)(queue); \ 1775 skb = tmp, tmp = skb->next) 1776 1777 #define skb_queue_walk_from(queue, skb) \ 1778 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ 1779 skb = skb->next) 1780 1781 #define skb_queue_walk_from_safe(queue, skb, tmp) \ 1782 for (tmp = skb->next; \ 1783 skb != (struct sk_buff *)(queue); \ 1784 skb = tmp, tmp = skb->next) 1785 1786 #define skb_queue_reverse_walk(queue, skb) \ 1787 for (skb = (queue)->prev; \ 1788 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \ 1789 skb = skb->prev) 1790 1791 1792 static inline bool skb_has_frag_list(const struct sk_buff *skb) 1793 { 1794 return skb_shinfo(skb)->frag_list != NULL; 1795 } 1796 1797 static inline void skb_frag_list_init(struct sk_buff *skb) 1798 { 1799 skb_shinfo(skb)->frag_list = NULL; 1800 } 1801 1802 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) 1803 { 1804 frag->next = skb_shinfo(skb)->frag_list; 1805 skb_shinfo(skb)->frag_list = frag; 1806 } 1807 1808 #define skb_walk_frags(skb, iter) \ 1809 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) 1810 1811 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, 1812 int *peeked, int *err); 1813 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, 1814 int noblock, int *err); 1815 extern unsigned int datagram_poll(struct file *file, struct socket *sock, 1816 struct poll_table_struct *wait); 1817 extern int skb_copy_datagram_iovec(const struct sk_buff *from, 1818 int offset, struct iovec *to, 1819 int size); 1820 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, 1821 int hlen, 1822 struct iovec *iov); 1823 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, 1824 int offset, 1825 const struct iovec *from, 1826 int from_offset, 1827 int len); 1828 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, 1829 int offset, 1830 const struct iovec *to, 1831 int to_offset, 1832 int size); 1833 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); 1834 extern void skb_free_datagram_locked(struct sock *sk, 1835 struct sk_buff *skb); 1836 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, 1837 unsigned int flags); 1838 extern __wsum skb_checksum(const struct sk_buff *skb, int offset, 1839 int len, __wsum csum); 1840 extern int skb_copy_bits(const struct sk_buff *skb, int offset, 1841 void *to, int len); 1842 extern int skb_store_bits(struct sk_buff *skb, int offset, 1843 const void *from, int len); 1844 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, 1845 int offset, u8 *to, int len, 1846 __wsum csum); 1847 extern int skb_splice_bits(struct sk_buff *skb, 1848 unsigned int offset, 1849 struct pipe_inode_info *pipe, 1850 unsigned int len, 1851 unsigned int flags); 1852 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); 1853 extern void skb_split(struct sk_buff *skb, 1854 struct sk_buff *skb1, const u32 len); 1855 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, 1856 int shiftlen); 1857 1858 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features); 1859 1860 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, 1861 int len, void *buffer) 1862 { 1863 int hlen = skb_headlen(skb); 1864 1865 if (hlen - offset >= len) 1866 return skb->data + offset; 1867 1868 if (skb_copy_bits(skb, offset, buffer, len) < 0) 1869 return NULL; 1870 1871 return buffer; 1872 } 1873 1874 static inline void skb_copy_from_linear_data(const struct sk_buff *skb, 1875 void *to, 1876 const unsigned int len) 1877 { 1878 memcpy(to, skb->data, len); 1879 } 1880 1881 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, 1882 const int offset, void *to, 1883 const unsigned int len) 1884 { 1885 memcpy(to, skb->data + offset, len); 1886 } 1887 1888 static inline void skb_copy_to_linear_data(struct sk_buff *skb, 1889 const void *from, 1890 const unsigned int len) 1891 { 1892 memcpy(skb->data, from, len); 1893 } 1894 1895 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, 1896 const int offset, 1897 const void *from, 1898 const unsigned int len) 1899 { 1900 memcpy(skb->data + offset, from, len); 1901 } 1902 1903 extern void skb_init(void); 1904 1905 static inline ktime_t skb_get_ktime(const struct sk_buff *skb) 1906 { 1907 return skb->tstamp; 1908 } 1909 1910 /** 1911 * skb_get_timestamp - get timestamp from a skb 1912 * @skb: skb to get stamp from 1913 * @stamp: pointer to struct timeval to store stamp in 1914 * 1915 * Timestamps are stored in the skb as offsets to a base timestamp. 1916 * This function converts the offset back to a struct timeval and stores 1917 * it in stamp. 1918 */ 1919 static inline void skb_get_timestamp(const struct sk_buff *skb, 1920 struct timeval *stamp) 1921 { 1922 *stamp = ktime_to_timeval(skb->tstamp); 1923 } 1924 1925 static inline void skb_get_timestampns(const struct sk_buff *skb, 1926 struct timespec *stamp) 1927 { 1928 *stamp = ktime_to_timespec(skb->tstamp); 1929 } 1930 1931 static inline void __net_timestamp(struct sk_buff *skb) 1932 { 1933 skb->tstamp = ktime_get_real(); 1934 } 1935 1936 static inline ktime_t net_timedelta(ktime_t t) 1937 { 1938 return ktime_sub(ktime_get_real(), t); 1939 } 1940 1941 static inline ktime_t net_invalid_timestamp(void) 1942 { 1943 return ktime_set(0, 0); 1944 } 1945 1946 extern void skb_timestamping_init(void); 1947 1948 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING 1949 1950 extern void skb_clone_tx_timestamp(struct sk_buff *skb); 1951 extern bool skb_defer_rx_timestamp(struct sk_buff *skb); 1952 1953 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ 1954 1955 static inline void skb_clone_tx_timestamp(struct sk_buff *skb) 1956 { 1957 } 1958 1959 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) 1960 { 1961 return false; 1962 } 1963 1964 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ 1965 1966 /** 1967 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps 1968 * 1969 * @skb: clone of the the original outgoing packet 1970 * @hwtstamps: hardware time stamps 1971 * 1972 */ 1973 void skb_complete_tx_timestamp(struct sk_buff *skb, 1974 struct skb_shared_hwtstamps *hwtstamps); 1975 1976 /** 1977 * skb_tstamp_tx - queue clone of skb with send time stamps 1978 * @orig_skb: the original outgoing packet 1979 * @hwtstamps: hardware time stamps, may be NULL if not available 1980 * 1981 * If the skb has a socket associated, then this function clones the 1982 * skb (thus sharing the actual data and optional structures), stores 1983 * the optional hardware time stamping information (if non NULL) or 1984 * generates a software time stamp (otherwise), then queues the clone 1985 * to the error queue of the socket. Errors are silently ignored. 1986 */ 1987 extern void skb_tstamp_tx(struct sk_buff *orig_skb, 1988 struct skb_shared_hwtstamps *hwtstamps); 1989 1990 static inline void sw_tx_timestamp(struct sk_buff *skb) 1991 { 1992 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && 1993 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 1994 skb_tstamp_tx(skb, NULL); 1995 } 1996 1997 /** 1998 * skb_tx_timestamp() - Driver hook for transmit timestamping 1999 * 2000 * Ethernet MAC Drivers should call this function in their hard_xmit() 2001 * function as soon as possible after giving the sk_buff to the MAC 2002 * hardware, but before freeing the sk_buff. 2003 * 2004 * @skb: A socket buffer. 2005 */ 2006 static inline void skb_tx_timestamp(struct sk_buff *skb) 2007 { 2008 skb_clone_tx_timestamp(skb); 2009 sw_tx_timestamp(skb); 2010 } 2011 2012 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); 2013 extern __sum16 __skb_checksum_complete(struct sk_buff *skb); 2014 2015 static inline int skb_csum_unnecessary(const struct sk_buff *skb) 2016 { 2017 return skb->ip_summed & CHECKSUM_UNNECESSARY; 2018 } 2019 2020 /** 2021 * skb_checksum_complete - Calculate checksum of an entire packet 2022 * @skb: packet to process 2023 * 2024 * This function calculates the checksum over the entire packet plus 2025 * the value of skb->csum. The latter can be used to supply the 2026 * checksum of a pseudo header as used by TCP/UDP. It returns the 2027 * checksum. 2028 * 2029 * For protocols that contain complete checksums such as ICMP/TCP/UDP, 2030 * this function can be used to verify that checksum on received 2031 * packets. In that case the function should return zero if the 2032 * checksum is correct. In particular, this function will return zero 2033 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the 2034 * hardware has already verified the correctness of the checksum. 2035 */ 2036 static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 2037 { 2038 return skb_csum_unnecessary(skb) ? 2039 0 : __skb_checksum_complete(skb); 2040 } 2041 2042 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2043 extern void nf_conntrack_destroy(struct nf_conntrack *nfct); 2044 static inline void nf_conntrack_put(struct nf_conntrack *nfct) 2045 { 2046 if (nfct && atomic_dec_and_test(&nfct->use)) 2047 nf_conntrack_destroy(nfct); 2048 } 2049 static inline void nf_conntrack_get(struct nf_conntrack *nfct) 2050 { 2051 if (nfct) 2052 atomic_inc(&nfct->use); 2053 } 2054 static inline void nf_conntrack_get_reasm(struct sk_buff *skb) 2055 { 2056 if (skb) 2057 atomic_inc(&skb->users); 2058 } 2059 static inline void nf_conntrack_put_reasm(struct sk_buff *skb) 2060 { 2061 if (skb) 2062 kfree_skb(skb); 2063 } 2064 #endif 2065 #ifdef CONFIG_BRIDGE_NETFILTER 2066 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) 2067 { 2068 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) 2069 kfree(nf_bridge); 2070 } 2071 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) 2072 { 2073 if (nf_bridge) 2074 atomic_inc(&nf_bridge->use); 2075 } 2076 #endif /* CONFIG_BRIDGE_NETFILTER */ 2077 static inline void nf_reset(struct sk_buff *skb) 2078 { 2079 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2080 nf_conntrack_put(skb->nfct); 2081 skb->nfct = NULL; 2082 nf_conntrack_put_reasm(skb->nfct_reasm); 2083 skb->nfct_reasm = NULL; 2084 #endif 2085 #ifdef CONFIG_BRIDGE_NETFILTER 2086 nf_bridge_put(skb->nf_bridge); 2087 skb->nf_bridge = NULL; 2088 #endif 2089 } 2090 2091 /* Note: This doesn't put any conntrack and bridge info in dst. */ 2092 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2093 { 2094 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2095 dst->nfct = src->nfct; 2096 nf_conntrack_get(src->nfct); 2097 dst->nfctinfo = src->nfctinfo; 2098 dst->nfct_reasm = src->nfct_reasm; 2099 nf_conntrack_get_reasm(src->nfct_reasm); 2100 #endif 2101 #ifdef CONFIG_BRIDGE_NETFILTER 2102 dst->nf_bridge = src->nf_bridge; 2103 nf_bridge_get(src->nf_bridge); 2104 #endif 2105 } 2106 2107 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) 2108 { 2109 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 2110 nf_conntrack_put(dst->nfct); 2111 nf_conntrack_put_reasm(dst->nfct_reasm); 2112 #endif 2113 #ifdef CONFIG_BRIDGE_NETFILTER 2114 nf_bridge_put(dst->nf_bridge); 2115 #endif 2116 __nf_copy(dst, src); 2117 } 2118 2119 #ifdef CONFIG_NETWORK_SECMARK 2120 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2121 { 2122 to->secmark = from->secmark; 2123 } 2124 2125 static inline void skb_init_secmark(struct sk_buff *skb) 2126 { 2127 skb->secmark = 0; 2128 } 2129 #else 2130 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) 2131 { } 2132 2133 static inline void skb_init_secmark(struct sk_buff *skb) 2134 { } 2135 #endif 2136 2137 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) 2138 { 2139 skb->queue_mapping = queue_mapping; 2140 } 2141 2142 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) 2143 { 2144 return skb->queue_mapping; 2145 } 2146 2147 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) 2148 { 2149 to->queue_mapping = from->queue_mapping; 2150 } 2151 2152 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) 2153 { 2154 skb->queue_mapping = rx_queue + 1; 2155 } 2156 2157 static inline u16 skb_get_rx_queue(const struct sk_buff *skb) 2158 { 2159 return skb->queue_mapping - 1; 2160 } 2161 2162 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) 2163 { 2164 return skb->queue_mapping != 0; 2165 } 2166 2167 extern u16 skb_tx_hash(const struct net_device *dev, 2168 const struct sk_buff *skb); 2169 2170 #ifdef CONFIG_XFRM 2171 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 2172 { 2173 return skb->sp; 2174 } 2175 #else 2176 static inline struct sec_path *skb_sec_path(struct sk_buff *skb) 2177 { 2178 return NULL; 2179 } 2180 #endif 2181 2182 static inline int skb_is_gso(const struct sk_buff *skb) 2183 { 2184 return skb_shinfo(skb)->gso_size; 2185 } 2186 2187 static inline int skb_is_gso_v6(const struct sk_buff *skb) 2188 { 2189 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; 2190 } 2191 2192 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); 2193 2194 static inline bool skb_warn_if_lro(const struct sk_buff *skb) 2195 { 2196 /* LRO sets gso_size but not gso_type, whereas if GSO is really 2197 * wanted then gso_type will be set. */ 2198 struct skb_shared_info *shinfo = skb_shinfo(skb); 2199 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && 2200 unlikely(shinfo->gso_type == 0)) { 2201 __skb_warn_lro_forwarding(skb); 2202 return true; 2203 } 2204 return false; 2205 } 2206 2207 static inline void skb_forward_csum(struct sk_buff *skb) 2208 { 2209 /* Unfortunately we don't support this one. Any brave souls? */ 2210 if (skb->ip_summed == CHECKSUM_COMPLETE) 2211 skb->ip_summed = CHECKSUM_NONE; 2212 } 2213 2214 /** 2215 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE 2216 * @skb: skb to check 2217 * 2218 * fresh skbs have their ip_summed set to CHECKSUM_NONE. 2219 * Instead of forcing ip_summed to CHECKSUM_NONE, we can 2220 * use this helper, to document places where we make this assertion. 2221 */ 2222 static inline void skb_checksum_none_assert(struct sk_buff *skb) 2223 { 2224 #ifdef DEBUG 2225 BUG_ON(skb->ip_summed != CHECKSUM_NONE); 2226 #endif 2227 } 2228 2229 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); 2230 #endif /* __KERNEL__ */ 2231 #endif /* _LINUX_SKBUFF_H */ 2232