1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the AF_INET socket handler. 7 * 8 * Version: @(#)sock.h 1.0.4 05/13/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Corey Minyard <wf-rch!minyard@relay.EU.net> 13 * Florian La Roche <flla@stud.uni-sb.de> 14 * 15 * Fixes: 16 * Alan Cox : Volatiles in skbuff pointers. See 17 * skbuff comments. May be overdone, 18 * better to prove they can be removed 19 * than the reverse. 20 * Alan Cox : Added a zapped field for tcp to note 21 * a socket is reset and must stay shut up 22 * Alan Cox : New fields for options 23 * Pauline Middelink : identd support 24 * Alan Cox : Eliminate low level recv/recvfrom 25 * David S. Miller : New socket lookup architecture. 26 * Steve Whitehouse: Default routines for sock_ops 27 * Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made 28 * protinfo be just a void pointer, as the 29 * protocol specific parts were moved to 30 * respective headers and ipv4/v6, etc now 31 * use private slabcaches for its socks 32 * Pedro Hortas : New flags field for socket options 33 * 34 * 35 * This program is free software; you can redistribute it and/or 36 * modify it under the terms of the GNU General Public License 37 * as published by the Free Software Foundation; either version 38 * 2 of the License, or (at your option) any later version. 39 */ 40 #ifndef _SOCK_H 41 #define _SOCK_H 42 43 #include <linux/kernel.h> 44 #include <linux/list.h> 45 #include <linux/list_nulls.h> 46 #include <linux/timer.h> 47 #include <linux/cache.h> 48 #include <linux/module.h> 49 #include <linux/lockdep.h> 50 #include <linux/netdevice.h> 51 #include <linux/skbuff.h> /* struct sk_buff */ 52 #include <linux/mm.h> 53 #include <linux/security.h> 54 #include <linux/slab.h> 55 56 #include <linux/filter.h> 57 #include <linux/rculist_nulls.h> 58 #include <linux/poll.h> 59 60 #include <asm/atomic.h> 61 #include <net/dst.h> 62 #include <net/checksum.h> 63 64 /* 65 * This structure really needs to be cleaned up. 66 * Most of it is for TCP, and not used by any of 67 * the other protocols. 68 */ 69 70 /* Define this to get the SOCK_DBG debugging facility. */ 71 #define SOCK_DEBUGGING 72 #ifdef SOCK_DEBUGGING 73 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 74 printk(KERN_DEBUG msg); } while (0) 75 #else 76 /* Validate arguments and do nothing */ 77 static inline void __attribute__ ((format (printf, 2, 3))) 78 SOCK_DEBUG(struct sock *sk, const char *msg, ...) 79 { 80 } 81 #endif 82 83 /* This is the per-socket lock. The spinlock provides a synchronization 84 * between user contexts and software interrupt processing, whereas the 85 * mini-semaphore synchronizes multiple users amongst themselves. 86 */ 87 typedef struct { 88 spinlock_t slock; 89 int owned; 90 wait_queue_head_t wq; 91 /* 92 * We express the mutex-alike socket_lock semantics 93 * to the lock validator by explicitly managing 94 * the slock as a lock variant (in addition to 95 * the slock itself): 96 */ 97 #ifdef CONFIG_DEBUG_LOCK_ALLOC 98 struct lockdep_map dep_map; 99 #endif 100 } socket_lock_t; 101 102 struct sock; 103 struct proto; 104 struct net; 105 106 /** 107 * struct sock_common - minimal network layer representation of sockets 108 * @skc_node: main hash linkage for various protocol lookup tables 109 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 110 * @skc_refcnt: reference count 111 * @skc_tx_queue_mapping: tx queue number for this connection 112 * @skc_hash: hash value used with various protocol lookup tables 113 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 114 * @skc_family: network address family 115 * @skc_state: Connection state 116 * @skc_reuse: %SO_REUSEADDR setting 117 * @skc_bound_dev_if: bound device index if != 0 118 * @skc_bind_node: bind hash linkage for various protocol lookup tables 119 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 120 * @skc_prot: protocol handlers inside a network family 121 * @skc_net: reference to the network namespace of this socket 122 * 123 * This is the minimal network layer representation of sockets, the header 124 * for struct sock and struct inet_timewait_sock. 125 */ 126 struct sock_common { 127 /* 128 * first fields are not copied in sock_copy() 129 */ 130 union { 131 struct hlist_node skc_node; 132 struct hlist_nulls_node skc_nulls_node; 133 }; 134 atomic_t skc_refcnt; 135 int skc_tx_queue_mapping; 136 137 union { 138 unsigned int skc_hash; 139 __u16 skc_u16hashes[2]; 140 }; 141 unsigned short skc_family; 142 volatile unsigned char skc_state; 143 unsigned char skc_reuse; 144 int skc_bound_dev_if; 145 union { 146 struct hlist_node skc_bind_node; 147 struct hlist_nulls_node skc_portaddr_node; 148 }; 149 struct proto *skc_prot; 150 #ifdef CONFIG_NET_NS 151 struct net *skc_net; 152 #endif 153 }; 154 155 /** 156 * struct sock - network layer representation of sockets 157 * @__sk_common: shared layout with inet_timewait_sock 158 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 159 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 160 * @sk_lock: synchronizer 161 * @sk_rcvbuf: size of receive buffer in bytes 162 * @sk_wq: sock wait queue and async head 163 * @sk_dst_cache: destination cache 164 * @sk_dst_lock: destination cache lock 165 * @sk_policy: flow policy 166 * @sk_rmem_alloc: receive queue bytes committed 167 * @sk_receive_queue: incoming packets 168 * @sk_wmem_alloc: transmit queue bytes committed 169 * @sk_write_queue: Packet sending queue 170 * @sk_async_wait_queue: DMA copied packets 171 * @sk_omem_alloc: "o" is "option" or "other" 172 * @sk_wmem_queued: persistent queue size 173 * @sk_forward_alloc: space allocated forward 174 * @sk_allocation: allocation mode 175 * @sk_sndbuf: size of send buffer in bytes 176 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 177 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 178 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets 179 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 180 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 181 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 182 * @sk_gso_max_size: Maximum GSO segment size to build 183 * @sk_lingertime: %SO_LINGER l_linger setting 184 * @sk_backlog: always used with the per-socket spinlock held 185 * @sk_callback_lock: used with the callbacks in the end of this struct 186 * @sk_error_queue: rarely used 187 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 188 * IPV6_ADDRFORM for instance) 189 * @sk_err: last error 190 * @sk_err_soft: errors that don't cause failure but are the cause of a 191 * persistent failure not just 'timed out' 192 * @sk_drops: raw/udp drops counter 193 * @sk_ack_backlog: current listen backlog 194 * @sk_max_ack_backlog: listen backlog set in listen() 195 * @sk_priority: %SO_PRIORITY setting 196 * @sk_type: socket type (%SOCK_STREAM, etc) 197 * @sk_protocol: which protocol this socket belongs in this network family 198 * @sk_peer_pid: &struct pid for this socket's peer 199 * @sk_peer_cred: %SO_PEERCRED setting 200 * @sk_rcvlowat: %SO_RCVLOWAT setting 201 * @sk_rcvtimeo: %SO_RCVTIMEO setting 202 * @sk_sndtimeo: %SO_SNDTIMEO setting 203 * @sk_rxhash: flow hash received from netif layer 204 * @sk_filter: socket filtering instructions 205 * @sk_protinfo: private area, net family specific, when not using slab 206 * @sk_timer: sock cleanup timer 207 * @sk_stamp: time stamp of last packet received 208 * @sk_socket: Identd and reporting IO signals 209 * @sk_user_data: RPC layer private data 210 * @sk_sndmsg_page: cached page for sendmsg 211 * @sk_sndmsg_off: cached offset for sendmsg 212 * @sk_send_head: front of stuff to transmit 213 * @sk_security: used by security modules 214 * @sk_mark: generic packet mark 215 * @sk_classid: this socket's cgroup classid 216 * @sk_write_pending: a write to stream socket waits to start 217 * @sk_state_change: callback to indicate change in the state of the sock 218 * @sk_data_ready: callback to indicate there is data to be processed 219 * @sk_write_space: callback to indicate there is bf sending space available 220 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 221 * @sk_backlog_rcv: callback to process the backlog 222 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 223 */ 224 struct sock { 225 /* 226 * Now struct inet_timewait_sock also uses sock_common, so please just 227 * don't add nothing before this first member (__sk_common) --acme 228 */ 229 struct sock_common __sk_common; 230 #define sk_node __sk_common.skc_node 231 #define sk_nulls_node __sk_common.skc_nulls_node 232 #define sk_refcnt __sk_common.skc_refcnt 233 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 234 235 #define sk_copy_start __sk_common.skc_hash 236 #define sk_hash __sk_common.skc_hash 237 #define sk_family __sk_common.skc_family 238 #define sk_state __sk_common.skc_state 239 #define sk_reuse __sk_common.skc_reuse 240 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 241 #define sk_bind_node __sk_common.skc_bind_node 242 #define sk_prot __sk_common.skc_prot 243 #define sk_net __sk_common.skc_net 244 kmemcheck_bitfield_begin(flags); 245 unsigned int sk_shutdown : 2, 246 sk_no_check : 2, 247 sk_userlocks : 4, 248 sk_protocol : 8, 249 sk_type : 16; 250 kmemcheck_bitfield_end(flags); 251 int sk_rcvbuf; 252 socket_lock_t sk_lock; 253 /* 254 * The backlog queue is special, it is always used with 255 * the per-socket spinlock held and requires low latency 256 * access. Therefore we special case it's implementation. 257 */ 258 struct { 259 struct sk_buff *head; 260 struct sk_buff *tail; 261 int len; 262 } sk_backlog; 263 struct socket_wq *sk_wq; 264 struct dst_entry *sk_dst_cache; 265 #ifdef CONFIG_XFRM 266 struct xfrm_policy *sk_policy[2]; 267 #endif 268 spinlock_t sk_dst_lock; 269 atomic_t sk_rmem_alloc; 270 atomic_t sk_wmem_alloc; 271 atomic_t sk_omem_alloc; 272 int sk_sndbuf; 273 struct sk_buff_head sk_receive_queue; 274 struct sk_buff_head sk_write_queue; 275 #ifdef CONFIG_NET_DMA 276 struct sk_buff_head sk_async_wait_queue; 277 #endif 278 int sk_wmem_queued; 279 int sk_forward_alloc; 280 gfp_t sk_allocation; 281 int sk_route_caps; 282 int sk_route_nocaps; 283 int sk_gso_type; 284 unsigned int sk_gso_max_size; 285 int sk_rcvlowat; 286 #ifdef CONFIG_RPS 287 __u32 sk_rxhash; 288 #endif 289 unsigned long sk_flags; 290 unsigned long sk_lingertime; 291 struct sk_buff_head sk_error_queue; 292 struct proto *sk_prot_creator; 293 rwlock_t sk_callback_lock; 294 int sk_err, 295 sk_err_soft; 296 atomic_t sk_drops; 297 unsigned short sk_ack_backlog; 298 unsigned short sk_max_ack_backlog; 299 __u32 sk_priority; 300 struct pid *sk_peer_pid; 301 const struct cred *sk_peer_cred; 302 long sk_rcvtimeo; 303 long sk_sndtimeo; 304 struct sk_filter *sk_filter; 305 void *sk_protinfo; 306 struct timer_list sk_timer; 307 ktime_t sk_stamp; 308 struct socket *sk_socket; 309 void *sk_user_data; 310 struct page *sk_sndmsg_page; 311 struct sk_buff *sk_send_head; 312 __u32 sk_sndmsg_off; 313 int sk_write_pending; 314 #ifdef CONFIG_SECURITY 315 void *sk_security; 316 #endif 317 __u32 sk_mark; 318 u32 sk_classid; 319 void (*sk_state_change)(struct sock *sk); 320 void (*sk_data_ready)(struct sock *sk, int bytes); 321 void (*sk_write_space)(struct sock *sk); 322 void (*sk_error_report)(struct sock *sk); 323 int (*sk_backlog_rcv)(struct sock *sk, 324 struct sk_buff *skb); 325 void (*sk_destruct)(struct sock *sk); 326 }; 327 328 /* 329 * Hashed lists helper routines 330 */ 331 static inline struct sock *sk_entry(const struct hlist_node *node) 332 { 333 return hlist_entry(node, struct sock, sk_node); 334 } 335 336 static inline struct sock *__sk_head(const struct hlist_head *head) 337 { 338 return hlist_entry(head->first, struct sock, sk_node); 339 } 340 341 static inline struct sock *sk_head(const struct hlist_head *head) 342 { 343 return hlist_empty(head) ? NULL : __sk_head(head); 344 } 345 346 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 347 { 348 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 349 } 350 351 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 352 { 353 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 354 } 355 356 static inline struct sock *sk_next(const struct sock *sk) 357 { 358 return sk->sk_node.next ? 359 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 360 } 361 362 static inline struct sock *sk_nulls_next(const struct sock *sk) 363 { 364 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 365 hlist_nulls_entry(sk->sk_nulls_node.next, 366 struct sock, sk_nulls_node) : 367 NULL; 368 } 369 370 static inline int sk_unhashed(const struct sock *sk) 371 { 372 return hlist_unhashed(&sk->sk_node); 373 } 374 375 static inline int sk_hashed(const struct sock *sk) 376 { 377 return !sk_unhashed(sk); 378 } 379 380 static __inline__ void sk_node_init(struct hlist_node *node) 381 { 382 node->pprev = NULL; 383 } 384 385 static __inline__ void sk_nulls_node_init(struct hlist_nulls_node *node) 386 { 387 node->pprev = NULL; 388 } 389 390 static __inline__ void __sk_del_node(struct sock *sk) 391 { 392 __hlist_del(&sk->sk_node); 393 } 394 395 /* NB: equivalent to hlist_del_init_rcu */ 396 static __inline__ int __sk_del_node_init(struct sock *sk) 397 { 398 if (sk_hashed(sk)) { 399 __sk_del_node(sk); 400 sk_node_init(&sk->sk_node); 401 return 1; 402 } 403 return 0; 404 } 405 406 /* Grab socket reference count. This operation is valid only 407 when sk is ALREADY grabbed f.e. it is found in hash table 408 or a list and the lookup is made under lock preventing hash table 409 modifications. 410 */ 411 412 static inline void sock_hold(struct sock *sk) 413 { 414 atomic_inc(&sk->sk_refcnt); 415 } 416 417 /* Ungrab socket in the context, which assumes that socket refcnt 418 cannot hit zero, f.e. it is true in context of any socketcall. 419 */ 420 static inline void __sock_put(struct sock *sk) 421 { 422 atomic_dec(&sk->sk_refcnt); 423 } 424 425 static __inline__ int sk_del_node_init(struct sock *sk) 426 { 427 int rc = __sk_del_node_init(sk); 428 429 if (rc) { 430 /* paranoid for a while -acme */ 431 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 432 __sock_put(sk); 433 } 434 return rc; 435 } 436 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 437 438 static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk) 439 { 440 if (sk_hashed(sk)) { 441 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 442 return 1; 443 } 444 return 0; 445 } 446 447 static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk) 448 { 449 int rc = __sk_nulls_del_node_init_rcu(sk); 450 451 if (rc) { 452 /* paranoid for a while -acme */ 453 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 454 __sock_put(sk); 455 } 456 return rc; 457 } 458 459 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list) 460 { 461 hlist_add_head(&sk->sk_node, list); 462 } 463 464 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list) 465 { 466 sock_hold(sk); 467 __sk_add_node(sk, list); 468 } 469 470 static __inline__ void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 471 { 472 sock_hold(sk); 473 hlist_add_head_rcu(&sk->sk_node, list); 474 } 475 476 static __inline__ void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 477 { 478 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 479 } 480 481 static __inline__ void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 482 { 483 sock_hold(sk); 484 __sk_nulls_add_node_rcu(sk, list); 485 } 486 487 static __inline__ void __sk_del_bind_node(struct sock *sk) 488 { 489 __hlist_del(&sk->sk_bind_node); 490 } 491 492 static __inline__ void sk_add_bind_node(struct sock *sk, 493 struct hlist_head *list) 494 { 495 hlist_add_head(&sk->sk_bind_node, list); 496 } 497 498 #define sk_for_each(__sk, node, list) \ 499 hlist_for_each_entry(__sk, node, list, sk_node) 500 #define sk_for_each_rcu(__sk, node, list) \ 501 hlist_for_each_entry_rcu(__sk, node, list, sk_node) 502 #define sk_nulls_for_each(__sk, node, list) \ 503 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 504 #define sk_nulls_for_each_rcu(__sk, node, list) \ 505 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 506 #define sk_for_each_from(__sk, node) \ 507 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ 508 hlist_for_each_entry_from(__sk, node, sk_node) 509 #define sk_nulls_for_each_from(__sk, node) \ 510 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 511 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 512 #define sk_for_each_continue(__sk, node) \ 513 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ 514 hlist_for_each_entry_continue(__sk, node, sk_node) 515 #define sk_for_each_safe(__sk, node, tmp, list) \ 516 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node) 517 #define sk_for_each_bound(__sk, node, list) \ 518 hlist_for_each_entry(__sk, node, list, sk_bind_node) 519 520 /* Sock flags */ 521 enum sock_flags { 522 SOCK_DEAD, 523 SOCK_DONE, 524 SOCK_URGINLINE, 525 SOCK_KEEPOPEN, 526 SOCK_LINGER, 527 SOCK_DESTROY, 528 SOCK_BROADCAST, 529 SOCK_TIMESTAMP, 530 SOCK_ZAPPED, 531 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 532 SOCK_DBG, /* %SO_DEBUG setting */ 533 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 534 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 535 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 536 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 537 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */ 538 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */ 539 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */ 540 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 541 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */ 542 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */ 543 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */ 544 SOCK_FASYNC, /* fasync() active */ 545 SOCK_RXQ_OVFL, 546 }; 547 548 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 549 { 550 nsk->sk_flags = osk->sk_flags; 551 } 552 553 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 554 { 555 __set_bit(flag, &sk->sk_flags); 556 } 557 558 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 559 { 560 __clear_bit(flag, &sk->sk_flags); 561 } 562 563 static inline int sock_flag(struct sock *sk, enum sock_flags flag) 564 { 565 return test_bit(flag, &sk->sk_flags); 566 } 567 568 static inline void sk_acceptq_removed(struct sock *sk) 569 { 570 sk->sk_ack_backlog--; 571 } 572 573 static inline void sk_acceptq_added(struct sock *sk) 574 { 575 sk->sk_ack_backlog++; 576 } 577 578 static inline int sk_acceptq_is_full(struct sock *sk) 579 { 580 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 581 } 582 583 /* 584 * Compute minimal free write space needed to queue new packets. 585 */ 586 static inline int sk_stream_min_wspace(struct sock *sk) 587 { 588 return sk->sk_wmem_queued >> 1; 589 } 590 591 static inline int sk_stream_wspace(struct sock *sk) 592 { 593 return sk->sk_sndbuf - sk->sk_wmem_queued; 594 } 595 596 extern void sk_stream_write_space(struct sock *sk); 597 598 static inline int sk_stream_memory_free(struct sock *sk) 599 { 600 return sk->sk_wmem_queued < sk->sk_sndbuf; 601 } 602 603 /* OOB backlog add */ 604 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 605 { 606 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 607 skb_dst_force(skb); 608 609 if (!sk->sk_backlog.tail) 610 sk->sk_backlog.head = skb; 611 else 612 sk->sk_backlog.tail->next = skb; 613 614 sk->sk_backlog.tail = skb; 615 skb->next = NULL; 616 } 617 618 /* 619 * Take into account size of receive queue and backlog queue 620 */ 621 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb) 622 { 623 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 624 625 return qsize + skb->truesize > sk->sk_rcvbuf; 626 } 627 628 /* The per-socket spinlock must be held here. */ 629 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb) 630 { 631 if (sk_rcvqueues_full(sk, skb)) 632 return -ENOBUFS; 633 634 __sk_add_backlog(sk, skb); 635 sk->sk_backlog.len += skb->truesize; 636 return 0; 637 } 638 639 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 640 { 641 return sk->sk_backlog_rcv(sk, skb); 642 } 643 644 static inline void sock_rps_record_flow(const struct sock *sk) 645 { 646 #ifdef CONFIG_RPS 647 struct rps_sock_flow_table *sock_flow_table; 648 649 rcu_read_lock(); 650 sock_flow_table = rcu_dereference(rps_sock_flow_table); 651 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash); 652 rcu_read_unlock(); 653 #endif 654 } 655 656 static inline void sock_rps_reset_flow(const struct sock *sk) 657 { 658 #ifdef CONFIG_RPS 659 struct rps_sock_flow_table *sock_flow_table; 660 661 rcu_read_lock(); 662 sock_flow_table = rcu_dereference(rps_sock_flow_table); 663 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash); 664 rcu_read_unlock(); 665 #endif 666 } 667 668 static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash) 669 { 670 #ifdef CONFIG_RPS 671 if (unlikely(sk->sk_rxhash != rxhash)) { 672 sock_rps_reset_flow(sk); 673 sk->sk_rxhash = rxhash; 674 } 675 #endif 676 } 677 678 #define sk_wait_event(__sk, __timeo, __condition) \ 679 ({ int __rc; \ 680 release_sock(__sk); \ 681 __rc = __condition; \ 682 if (!__rc) { \ 683 *(__timeo) = schedule_timeout(*(__timeo)); \ 684 } \ 685 lock_sock(__sk); \ 686 __rc = __condition; \ 687 __rc; \ 688 }) 689 690 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 691 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 692 extern void sk_stream_wait_close(struct sock *sk, long timeo_p); 693 extern int sk_stream_error(struct sock *sk, int flags, int err); 694 extern void sk_stream_kill_queues(struct sock *sk); 695 696 extern int sk_wait_data(struct sock *sk, long *timeo); 697 698 struct request_sock_ops; 699 struct timewait_sock_ops; 700 struct inet_hashinfo; 701 struct raw_hashinfo; 702 703 /* Networking protocol blocks we attach to sockets. 704 * socket layer -> transport layer interface 705 * transport -> network interface is defined by struct inet_proto 706 */ 707 struct proto { 708 void (*close)(struct sock *sk, 709 long timeout); 710 int (*connect)(struct sock *sk, 711 struct sockaddr *uaddr, 712 int addr_len); 713 int (*disconnect)(struct sock *sk, int flags); 714 715 struct sock * (*accept) (struct sock *sk, int flags, int *err); 716 717 int (*ioctl)(struct sock *sk, int cmd, 718 unsigned long arg); 719 int (*init)(struct sock *sk); 720 void (*destroy)(struct sock *sk); 721 void (*shutdown)(struct sock *sk, int how); 722 int (*setsockopt)(struct sock *sk, int level, 723 int optname, char __user *optval, 724 unsigned int optlen); 725 int (*getsockopt)(struct sock *sk, int level, 726 int optname, char __user *optval, 727 int __user *option); 728 #ifdef CONFIG_COMPAT 729 int (*compat_setsockopt)(struct sock *sk, 730 int level, 731 int optname, char __user *optval, 732 unsigned int optlen); 733 int (*compat_getsockopt)(struct sock *sk, 734 int level, 735 int optname, char __user *optval, 736 int __user *option); 737 #endif 738 int (*sendmsg)(struct kiocb *iocb, struct sock *sk, 739 struct msghdr *msg, size_t len); 740 int (*recvmsg)(struct kiocb *iocb, struct sock *sk, 741 struct msghdr *msg, 742 size_t len, int noblock, int flags, 743 int *addr_len); 744 int (*sendpage)(struct sock *sk, struct page *page, 745 int offset, size_t size, int flags); 746 int (*bind)(struct sock *sk, 747 struct sockaddr *uaddr, int addr_len); 748 749 int (*backlog_rcv) (struct sock *sk, 750 struct sk_buff *skb); 751 752 /* Keeping track of sk's, looking them up, and port selection methods. */ 753 void (*hash)(struct sock *sk); 754 void (*unhash)(struct sock *sk); 755 int (*get_port)(struct sock *sk, unsigned short snum); 756 757 /* Keeping track of sockets in use */ 758 #ifdef CONFIG_PROC_FS 759 unsigned int inuse_idx; 760 #endif 761 762 /* Memory pressure */ 763 void (*enter_memory_pressure)(struct sock *sk); 764 atomic_t *memory_allocated; /* Current allocated memory. */ 765 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 766 /* 767 * Pressure flag: try to collapse. 768 * Technical note: it is used by multiple contexts non atomically. 769 * All the __sk_mem_schedule() is of this nature: accounting 770 * is strict, actions are advisory and have some latency. 771 */ 772 int *memory_pressure; 773 int *sysctl_mem; 774 int *sysctl_wmem; 775 int *sysctl_rmem; 776 int max_header; 777 bool no_autobind; 778 779 struct kmem_cache *slab; 780 unsigned int obj_size; 781 int slab_flags; 782 783 struct percpu_counter *orphan_count; 784 785 struct request_sock_ops *rsk_prot; 786 struct timewait_sock_ops *twsk_prot; 787 788 union { 789 struct inet_hashinfo *hashinfo; 790 struct udp_table *udp_table; 791 struct raw_hashinfo *raw_hash; 792 } h; 793 794 struct module *owner; 795 796 char name[32]; 797 798 struct list_head node; 799 #ifdef SOCK_REFCNT_DEBUG 800 atomic_t socks; 801 #endif 802 }; 803 804 extern int proto_register(struct proto *prot, int alloc_slab); 805 extern void proto_unregister(struct proto *prot); 806 807 #ifdef SOCK_REFCNT_DEBUG 808 static inline void sk_refcnt_debug_inc(struct sock *sk) 809 { 810 atomic_inc(&sk->sk_prot->socks); 811 } 812 813 static inline void sk_refcnt_debug_dec(struct sock *sk) 814 { 815 atomic_dec(&sk->sk_prot->socks); 816 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 817 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 818 } 819 820 static inline void sk_refcnt_debug_release(const struct sock *sk) 821 { 822 if (atomic_read(&sk->sk_refcnt) != 1) 823 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 824 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 825 } 826 #else /* SOCK_REFCNT_DEBUG */ 827 #define sk_refcnt_debug_inc(sk) do { } while (0) 828 #define sk_refcnt_debug_dec(sk) do { } while (0) 829 #define sk_refcnt_debug_release(sk) do { } while (0) 830 #endif /* SOCK_REFCNT_DEBUG */ 831 832 833 #ifdef CONFIG_PROC_FS 834 /* Called with local bh disabled */ 835 extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 836 extern int sock_prot_inuse_get(struct net *net, struct proto *proto); 837 #else 838 static void inline sock_prot_inuse_add(struct net *net, struct proto *prot, 839 int inc) 840 { 841 } 842 #endif 843 844 845 /* With per-bucket locks this operation is not-atomic, so that 846 * this version is not worse. 847 */ 848 static inline void __sk_prot_rehash(struct sock *sk) 849 { 850 sk->sk_prot->unhash(sk); 851 sk->sk_prot->hash(sk); 852 } 853 854 /* About 10 seconds */ 855 #define SOCK_DESTROY_TIME (10*HZ) 856 857 /* Sockets 0-1023 can't be bound to unless you are superuser */ 858 #define PROT_SOCK 1024 859 860 #define SHUTDOWN_MASK 3 861 #define RCV_SHUTDOWN 1 862 #define SEND_SHUTDOWN 2 863 864 #define SOCK_SNDBUF_LOCK 1 865 #define SOCK_RCVBUF_LOCK 2 866 #define SOCK_BINDADDR_LOCK 4 867 #define SOCK_BINDPORT_LOCK 8 868 869 /* sock_iocb: used to kick off async processing of socket ios */ 870 struct sock_iocb { 871 struct list_head list; 872 873 int flags; 874 int size; 875 struct socket *sock; 876 struct sock *sk; 877 struct scm_cookie *scm; 878 struct msghdr *msg, async_msg; 879 struct kiocb *kiocb; 880 }; 881 882 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb) 883 { 884 return (struct sock_iocb *)iocb->private; 885 } 886 887 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si) 888 { 889 return si->kiocb; 890 } 891 892 struct socket_alloc { 893 struct socket socket; 894 struct inode vfs_inode; 895 }; 896 897 static inline struct socket *SOCKET_I(struct inode *inode) 898 { 899 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 900 } 901 902 static inline struct inode *SOCK_INODE(struct socket *socket) 903 { 904 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 905 } 906 907 /* 908 * Functions for memory accounting 909 */ 910 extern int __sk_mem_schedule(struct sock *sk, int size, int kind); 911 extern void __sk_mem_reclaim(struct sock *sk); 912 913 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 914 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 915 #define SK_MEM_SEND 0 916 #define SK_MEM_RECV 1 917 918 static inline int sk_mem_pages(int amt) 919 { 920 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 921 } 922 923 static inline int sk_has_account(struct sock *sk) 924 { 925 /* return true if protocol supports memory accounting */ 926 return !!sk->sk_prot->memory_allocated; 927 } 928 929 static inline int sk_wmem_schedule(struct sock *sk, int size) 930 { 931 if (!sk_has_account(sk)) 932 return 1; 933 return size <= sk->sk_forward_alloc || 934 __sk_mem_schedule(sk, size, SK_MEM_SEND); 935 } 936 937 static inline int sk_rmem_schedule(struct sock *sk, int size) 938 { 939 if (!sk_has_account(sk)) 940 return 1; 941 return size <= sk->sk_forward_alloc || 942 __sk_mem_schedule(sk, size, SK_MEM_RECV); 943 } 944 945 static inline void sk_mem_reclaim(struct sock *sk) 946 { 947 if (!sk_has_account(sk)) 948 return; 949 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 950 __sk_mem_reclaim(sk); 951 } 952 953 static inline void sk_mem_reclaim_partial(struct sock *sk) 954 { 955 if (!sk_has_account(sk)) 956 return; 957 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 958 __sk_mem_reclaim(sk); 959 } 960 961 static inline void sk_mem_charge(struct sock *sk, int size) 962 { 963 if (!sk_has_account(sk)) 964 return; 965 sk->sk_forward_alloc -= size; 966 } 967 968 static inline void sk_mem_uncharge(struct sock *sk, int size) 969 { 970 if (!sk_has_account(sk)) 971 return; 972 sk->sk_forward_alloc += size; 973 } 974 975 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 976 { 977 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 978 sk->sk_wmem_queued -= skb->truesize; 979 sk_mem_uncharge(sk, skb->truesize); 980 __kfree_skb(skb); 981 } 982 983 /* Used by processes to "lock" a socket state, so that 984 * interrupts and bottom half handlers won't change it 985 * from under us. It essentially blocks any incoming 986 * packets, so that we won't get any new data or any 987 * packets that change the state of the socket. 988 * 989 * While locked, BH processing will add new packets to 990 * the backlog queue. This queue is processed by the 991 * owner of the socket lock right before it is released. 992 * 993 * Since ~2.3.5 it is also exclusive sleep lock serializing 994 * accesses from user process context. 995 */ 996 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned) 997 998 /* 999 * Macro so as to not evaluate some arguments when 1000 * lockdep is not enabled. 1001 * 1002 * Mark both the sk_lock and the sk_lock.slock as a 1003 * per-address-family lock class. 1004 */ 1005 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1006 do { \ 1007 sk->sk_lock.owned = 0; \ 1008 init_waitqueue_head(&sk->sk_lock.wq); \ 1009 spin_lock_init(&(sk)->sk_lock.slock); \ 1010 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1011 sizeof((sk)->sk_lock)); \ 1012 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1013 (skey), (sname)); \ 1014 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1015 } while (0) 1016 1017 extern void lock_sock_nested(struct sock *sk, int subclass); 1018 1019 static inline void lock_sock(struct sock *sk) 1020 { 1021 lock_sock_nested(sk, 0); 1022 } 1023 1024 extern void release_sock(struct sock *sk); 1025 1026 /* BH context may only use the following locking interface. */ 1027 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1028 #define bh_lock_sock_nested(__sk) \ 1029 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1030 SINGLE_DEPTH_NESTING) 1031 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1032 1033 extern bool lock_sock_fast(struct sock *sk); 1034 /** 1035 * unlock_sock_fast - complement of lock_sock_fast 1036 * @sk: socket 1037 * @slow: slow mode 1038 * 1039 * fast unlock socket for user context. 1040 * If slow mode is on, we call regular release_sock() 1041 */ 1042 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1043 { 1044 if (slow) 1045 release_sock(sk); 1046 else 1047 spin_unlock_bh(&sk->sk_lock.slock); 1048 } 1049 1050 1051 extern struct sock *sk_alloc(struct net *net, int family, 1052 gfp_t priority, 1053 struct proto *prot); 1054 extern void sk_free(struct sock *sk); 1055 extern void sk_release_kernel(struct sock *sk); 1056 extern struct sock *sk_clone(const struct sock *sk, 1057 const gfp_t priority); 1058 1059 extern struct sk_buff *sock_wmalloc(struct sock *sk, 1060 unsigned long size, int force, 1061 gfp_t priority); 1062 extern struct sk_buff *sock_rmalloc(struct sock *sk, 1063 unsigned long size, int force, 1064 gfp_t priority); 1065 extern void sock_wfree(struct sk_buff *skb); 1066 extern void sock_rfree(struct sk_buff *skb); 1067 1068 extern int sock_setsockopt(struct socket *sock, int level, 1069 int op, char __user *optval, 1070 unsigned int optlen); 1071 1072 extern int sock_getsockopt(struct socket *sock, int level, 1073 int op, char __user *optval, 1074 int __user *optlen); 1075 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk, 1076 unsigned long size, 1077 int noblock, 1078 int *errcode); 1079 extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk, 1080 unsigned long header_len, 1081 unsigned long data_len, 1082 int noblock, 1083 int *errcode); 1084 extern void *sock_kmalloc(struct sock *sk, int size, 1085 gfp_t priority); 1086 extern void sock_kfree_s(struct sock *sk, void *mem, int size); 1087 extern void sk_send_sigurg(struct sock *sk); 1088 1089 #ifdef CONFIG_CGROUPS 1090 extern void sock_update_classid(struct sock *sk); 1091 #else 1092 static inline void sock_update_classid(struct sock *sk) 1093 { 1094 } 1095 #endif 1096 1097 /* 1098 * Functions to fill in entries in struct proto_ops when a protocol 1099 * does not implement a particular function. 1100 */ 1101 extern int sock_no_bind(struct socket *, 1102 struct sockaddr *, int); 1103 extern int sock_no_connect(struct socket *, 1104 struct sockaddr *, int, int); 1105 extern int sock_no_socketpair(struct socket *, 1106 struct socket *); 1107 extern int sock_no_accept(struct socket *, 1108 struct socket *, int); 1109 extern int sock_no_getname(struct socket *, 1110 struct sockaddr *, int *, int); 1111 extern unsigned int sock_no_poll(struct file *, struct socket *, 1112 struct poll_table_struct *); 1113 extern int sock_no_ioctl(struct socket *, unsigned int, 1114 unsigned long); 1115 extern int sock_no_listen(struct socket *, int); 1116 extern int sock_no_shutdown(struct socket *, int); 1117 extern int sock_no_getsockopt(struct socket *, int , int, 1118 char __user *, int __user *); 1119 extern int sock_no_setsockopt(struct socket *, int, int, 1120 char __user *, unsigned int); 1121 extern int sock_no_sendmsg(struct kiocb *, struct socket *, 1122 struct msghdr *, size_t); 1123 extern int sock_no_recvmsg(struct kiocb *, struct socket *, 1124 struct msghdr *, size_t, int); 1125 extern int sock_no_mmap(struct file *file, 1126 struct socket *sock, 1127 struct vm_area_struct *vma); 1128 extern ssize_t sock_no_sendpage(struct socket *sock, 1129 struct page *page, 1130 int offset, size_t size, 1131 int flags); 1132 1133 /* 1134 * Functions to fill in entries in struct proto_ops when a protocol 1135 * uses the inet style. 1136 */ 1137 extern int sock_common_getsockopt(struct socket *sock, int level, int optname, 1138 char __user *optval, int __user *optlen); 1139 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock, 1140 struct msghdr *msg, size_t size, int flags); 1141 extern int sock_common_setsockopt(struct socket *sock, int level, int optname, 1142 char __user *optval, unsigned int optlen); 1143 extern int compat_sock_common_getsockopt(struct socket *sock, int level, 1144 int optname, char __user *optval, int __user *optlen); 1145 extern int compat_sock_common_setsockopt(struct socket *sock, int level, 1146 int optname, char __user *optval, unsigned int optlen); 1147 1148 extern void sk_common_release(struct sock *sk); 1149 1150 /* 1151 * Default socket callbacks and setup code 1152 */ 1153 1154 /* Initialise core socket variables */ 1155 extern void sock_init_data(struct socket *sock, struct sock *sk); 1156 1157 /** 1158 * sk_filter_release - release a socket filter 1159 * @fp: filter to remove 1160 * 1161 * Remove a filter from a socket and release its resources. 1162 */ 1163 1164 static inline void sk_filter_release(struct sk_filter *fp) 1165 { 1166 if (atomic_dec_and_test(&fp->refcnt)) 1167 kfree(fp); 1168 } 1169 1170 static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) 1171 { 1172 unsigned int size = sk_filter_len(fp); 1173 1174 atomic_sub(size, &sk->sk_omem_alloc); 1175 sk_filter_release(fp); 1176 } 1177 1178 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp) 1179 { 1180 atomic_inc(&fp->refcnt); 1181 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc); 1182 } 1183 1184 /* 1185 * Socket reference counting postulates. 1186 * 1187 * * Each user of socket SHOULD hold a reference count. 1188 * * Each access point to socket (an hash table bucket, reference from a list, 1189 * running timer, skb in flight MUST hold a reference count. 1190 * * When reference count hits 0, it means it will never increase back. 1191 * * When reference count hits 0, it means that no references from 1192 * outside exist to this socket and current process on current CPU 1193 * is last user and may/should destroy this socket. 1194 * * sk_free is called from any context: process, BH, IRQ. When 1195 * it is called, socket has no references from outside -> sk_free 1196 * may release descendant resources allocated by the socket, but 1197 * to the time when it is called, socket is NOT referenced by any 1198 * hash tables, lists etc. 1199 * * Packets, delivered from outside (from network or from another process) 1200 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1201 * when they sit in queue. Otherwise, packets will leak to hole, when 1202 * socket is looked up by one cpu and unhasing is made by another CPU. 1203 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1204 * (leak to backlog). Packet socket does all the processing inside 1205 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1206 * use separate SMP lock, so that they are prone too. 1207 */ 1208 1209 /* Ungrab socket and destroy it, if it was the last reference. */ 1210 static inline void sock_put(struct sock *sk) 1211 { 1212 if (atomic_dec_and_test(&sk->sk_refcnt)) 1213 sk_free(sk); 1214 } 1215 1216 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1217 const int nested); 1218 1219 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1220 { 1221 sk->sk_tx_queue_mapping = tx_queue; 1222 } 1223 1224 static inline void sk_tx_queue_clear(struct sock *sk) 1225 { 1226 sk->sk_tx_queue_mapping = -1; 1227 } 1228 1229 static inline int sk_tx_queue_get(const struct sock *sk) 1230 { 1231 return sk ? sk->sk_tx_queue_mapping : -1; 1232 } 1233 1234 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1235 { 1236 sk_tx_queue_clear(sk); 1237 sk->sk_socket = sock; 1238 } 1239 1240 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1241 { 1242 return &sk->sk_wq->wait; 1243 } 1244 /* Detach socket from process context. 1245 * Announce socket dead, detach it from wait queue and inode. 1246 * Note that parent inode held reference count on this struct sock, 1247 * we do not release it in this function, because protocol 1248 * probably wants some additional cleanups or even continuing 1249 * to work with this socket (TCP). 1250 */ 1251 static inline void sock_orphan(struct sock *sk) 1252 { 1253 write_lock_bh(&sk->sk_callback_lock); 1254 sock_set_flag(sk, SOCK_DEAD); 1255 sk_set_socket(sk, NULL); 1256 sk->sk_wq = NULL; 1257 write_unlock_bh(&sk->sk_callback_lock); 1258 } 1259 1260 static inline void sock_graft(struct sock *sk, struct socket *parent) 1261 { 1262 write_lock_bh(&sk->sk_callback_lock); 1263 rcu_assign_pointer(sk->sk_wq, parent->wq); 1264 parent->sk = sk; 1265 sk_set_socket(sk, parent); 1266 security_sock_graft(sk, parent); 1267 write_unlock_bh(&sk->sk_callback_lock); 1268 } 1269 1270 extern int sock_i_uid(struct sock *sk); 1271 extern unsigned long sock_i_ino(struct sock *sk); 1272 1273 static inline struct dst_entry * 1274 __sk_dst_get(struct sock *sk) 1275 { 1276 return rcu_dereference_check(sk->sk_dst_cache, rcu_read_lock_held() || 1277 sock_owned_by_user(sk) || 1278 lockdep_is_held(&sk->sk_lock.slock)); 1279 } 1280 1281 static inline struct dst_entry * 1282 sk_dst_get(struct sock *sk) 1283 { 1284 struct dst_entry *dst; 1285 1286 rcu_read_lock(); 1287 dst = rcu_dereference(sk->sk_dst_cache); 1288 if (dst) 1289 dst_hold(dst); 1290 rcu_read_unlock(); 1291 return dst; 1292 } 1293 1294 extern void sk_reset_txq(struct sock *sk); 1295 1296 static inline void dst_negative_advice(struct sock *sk) 1297 { 1298 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1299 1300 if (dst && dst->ops->negative_advice) { 1301 ndst = dst->ops->negative_advice(dst); 1302 1303 if (ndst != dst) { 1304 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1305 sk_reset_txq(sk); 1306 } 1307 } 1308 } 1309 1310 static inline void 1311 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1312 { 1313 struct dst_entry *old_dst; 1314 1315 sk_tx_queue_clear(sk); 1316 /* 1317 * This can be called while sk is owned by the caller only, 1318 * with no state that can be checked in a rcu_dereference_check() cond 1319 */ 1320 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1321 rcu_assign_pointer(sk->sk_dst_cache, dst); 1322 dst_release(old_dst); 1323 } 1324 1325 static inline void 1326 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1327 { 1328 spin_lock(&sk->sk_dst_lock); 1329 __sk_dst_set(sk, dst); 1330 spin_unlock(&sk->sk_dst_lock); 1331 } 1332 1333 static inline void 1334 __sk_dst_reset(struct sock *sk) 1335 { 1336 __sk_dst_set(sk, NULL); 1337 } 1338 1339 static inline void 1340 sk_dst_reset(struct sock *sk) 1341 { 1342 spin_lock(&sk->sk_dst_lock); 1343 __sk_dst_reset(sk); 1344 spin_unlock(&sk->sk_dst_lock); 1345 } 1346 1347 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1348 1349 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1350 1351 static inline int sk_can_gso(const struct sock *sk) 1352 { 1353 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1354 } 1355 1356 extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1357 1358 static inline void sk_nocaps_add(struct sock *sk, int flags) 1359 { 1360 sk->sk_route_nocaps |= flags; 1361 sk->sk_route_caps &= ~flags; 1362 } 1363 1364 static inline int skb_copy_to_page(struct sock *sk, char __user *from, 1365 struct sk_buff *skb, struct page *page, 1366 int off, int copy) 1367 { 1368 if (skb->ip_summed == CHECKSUM_NONE) { 1369 int err = 0; 1370 __wsum csum = csum_and_copy_from_user(from, 1371 page_address(page) + off, 1372 copy, 0, &err); 1373 if (err) 1374 return err; 1375 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1376 } else if (copy_from_user(page_address(page) + off, from, copy)) 1377 return -EFAULT; 1378 1379 skb->len += copy; 1380 skb->data_len += copy; 1381 skb->truesize += copy; 1382 sk->sk_wmem_queued += copy; 1383 sk_mem_charge(sk, copy); 1384 return 0; 1385 } 1386 1387 /** 1388 * sk_wmem_alloc_get - returns write allocations 1389 * @sk: socket 1390 * 1391 * Returns sk_wmem_alloc minus initial offset of one 1392 */ 1393 static inline int sk_wmem_alloc_get(const struct sock *sk) 1394 { 1395 return atomic_read(&sk->sk_wmem_alloc) - 1; 1396 } 1397 1398 /** 1399 * sk_rmem_alloc_get - returns read allocations 1400 * @sk: socket 1401 * 1402 * Returns sk_rmem_alloc 1403 */ 1404 static inline int sk_rmem_alloc_get(const struct sock *sk) 1405 { 1406 return atomic_read(&sk->sk_rmem_alloc); 1407 } 1408 1409 /** 1410 * sk_has_allocations - check if allocations are outstanding 1411 * @sk: socket 1412 * 1413 * Returns true if socket has write or read allocations 1414 */ 1415 static inline int sk_has_allocations(const struct sock *sk) 1416 { 1417 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1418 } 1419 1420 /** 1421 * wq_has_sleeper - check if there are any waiting processes 1422 * @wq: struct socket_wq 1423 * 1424 * Returns true if socket_wq has waiting processes 1425 * 1426 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory 1427 * barrier call. They were added due to the race found within the tcp code. 1428 * 1429 * Consider following tcp code paths: 1430 * 1431 * CPU1 CPU2 1432 * 1433 * sys_select receive packet 1434 * ... ... 1435 * __add_wait_queue update tp->rcv_nxt 1436 * ... ... 1437 * tp->rcv_nxt check sock_def_readable 1438 * ... { 1439 * schedule rcu_read_lock(); 1440 * wq = rcu_dereference(sk->sk_wq); 1441 * if (wq && waitqueue_active(&wq->wait)) 1442 * wake_up_interruptible(&wq->wait) 1443 * ... 1444 * } 1445 * 1446 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1447 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1448 * could then endup calling schedule and sleep forever if there are no more 1449 * data on the socket. 1450 * 1451 */ 1452 static inline bool wq_has_sleeper(struct socket_wq *wq) 1453 { 1454 1455 /* 1456 * We need to be sure we are in sync with the 1457 * add_wait_queue modifications to the wait queue. 1458 * 1459 * This memory barrier is paired in the sock_poll_wait. 1460 */ 1461 smp_mb(); 1462 return wq && waitqueue_active(&wq->wait); 1463 } 1464 1465 /** 1466 * sock_poll_wait - place memory barrier behind the poll_wait call. 1467 * @filp: file 1468 * @wait_address: socket wait queue 1469 * @p: poll_table 1470 * 1471 * See the comments in the wq_has_sleeper function. 1472 */ 1473 static inline void sock_poll_wait(struct file *filp, 1474 wait_queue_head_t *wait_address, poll_table *p) 1475 { 1476 if (p && wait_address) { 1477 poll_wait(filp, wait_address, p); 1478 /* 1479 * We need to be sure we are in sync with the 1480 * socket flags modification. 1481 * 1482 * This memory barrier is paired in the wq_has_sleeper. 1483 */ 1484 smp_mb(); 1485 } 1486 } 1487 1488 /* 1489 * Queue a received datagram if it will fit. Stream and sequenced 1490 * protocols can't normally use this as they need to fit buffers in 1491 * and play with them. 1492 * 1493 * Inlined as it's very short and called for pretty much every 1494 * packet ever received. 1495 */ 1496 1497 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1498 { 1499 skb_orphan(skb); 1500 skb->sk = sk; 1501 skb->destructor = sock_wfree; 1502 /* 1503 * We used to take a refcount on sk, but following operation 1504 * is enough to guarantee sk_free() wont free this sock until 1505 * all in-flight packets are completed 1506 */ 1507 atomic_add(skb->truesize, &sk->sk_wmem_alloc); 1508 } 1509 1510 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1511 { 1512 skb_orphan(skb); 1513 skb->sk = sk; 1514 skb->destructor = sock_rfree; 1515 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1516 sk_mem_charge(sk, skb->truesize); 1517 } 1518 1519 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer, 1520 unsigned long expires); 1521 1522 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer); 1523 1524 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1525 1526 extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 1527 1528 /* 1529 * Recover an error report and clear atomically 1530 */ 1531 1532 static inline int sock_error(struct sock *sk) 1533 { 1534 int err; 1535 if (likely(!sk->sk_err)) 1536 return 0; 1537 err = xchg(&sk->sk_err, 0); 1538 return -err; 1539 } 1540 1541 static inline unsigned long sock_wspace(struct sock *sk) 1542 { 1543 int amt = 0; 1544 1545 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 1546 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 1547 if (amt < 0) 1548 amt = 0; 1549 } 1550 return amt; 1551 } 1552 1553 static inline void sk_wake_async(struct sock *sk, int how, int band) 1554 { 1555 if (sock_flag(sk, SOCK_FASYNC)) 1556 sock_wake_async(sk->sk_socket, how, band); 1557 } 1558 1559 #define SOCK_MIN_SNDBUF 2048 1560 #define SOCK_MIN_RCVBUF 256 1561 1562 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 1563 { 1564 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 1565 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 1566 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF); 1567 } 1568 } 1569 1570 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp); 1571 1572 static inline struct page *sk_stream_alloc_page(struct sock *sk) 1573 { 1574 struct page *page = NULL; 1575 1576 page = alloc_pages(sk->sk_allocation, 0); 1577 if (!page) { 1578 sk->sk_prot->enter_memory_pressure(sk); 1579 sk_stream_moderate_sndbuf(sk); 1580 } 1581 return page; 1582 } 1583 1584 /* 1585 * Default write policy as shown to user space via poll/select/SIGIO 1586 */ 1587 static inline int sock_writeable(const struct sock *sk) 1588 { 1589 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 1590 } 1591 1592 static inline gfp_t gfp_any(void) 1593 { 1594 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 1595 } 1596 1597 static inline long sock_rcvtimeo(const struct sock *sk, int noblock) 1598 { 1599 return noblock ? 0 : sk->sk_rcvtimeo; 1600 } 1601 1602 static inline long sock_sndtimeo(const struct sock *sk, int noblock) 1603 { 1604 return noblock ? 0 : sk->sk_sndtimeo; 1605 } 1606 1607 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 1608 { 1609 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 1610 } 1611 1612 /* Alas, with timeout socket operations are not restartable. 1613 * Compare this to poll(). 1614 */ 1615 static inline int sock_intr_errno(long timeo) 1616 { 1617 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 1618 } 1619 1620 extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 1621 struct sk_buff *skb); 1622 1623 static __inline__ void 1624 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 1625 { 1626 ktime_t kt = skb->tstamp; 1627 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 1628 1629 /* 1630 * generate control messages if 1631 * - receive time stamping in software requested (SOCK_RCVTSTAMP 1632 * or SOCK_TIMESTAMPING_RX_SOFTWARE) 1633 * - software time stamp available and wanted 1634 * (SOCK_TIMESTAMPING_SOFTWARE) 1635 * - hardware time stamps available and wanted 1636 * (SOCK_TIMESTAMPING_SYS_HARDWARE or 1637 * SOCK_TIMESTAMPING_RAW_HARDWARE) 1638 */ 1639 if (sock_flag(sk, SOCK_RCVTSTAMP) || 1640 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) || 1641 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) || 1642 (hwtstamps->hwtstamp.tv64 && 1643 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) || 1644 (hwtstamps->syststamp.tv64 && 1645 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))) 1646 __sock_recv_timestamp(msg, sk, skb); 1647 else 1648 sk->sk_stamp = kt; 1649 } 1650 1651 extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 1652 struct sk_buff *skb); 1653 1654 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 1655 struct sk_buff *skb) 1656 { 1657 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 1658 (1UL << SOCK_RCVTSTAMP) | \ 1659 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \ 1660 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \ 1661 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \ 1662 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE)) 1663 1664 if (sk->sk_flags & FLAGS_TS_OR_DROPS) 1665 __sock_recv_ts_and_drops(msg, sk, skb); 1666 else 1667 sk->sk_stamp = skb->tstamp; 1668 } 1669 1670 /** 1671 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 1672 * @msg: outgoing packet 1673 * @sk: socket sending this packet 1674 * @shtx: filled with instructions for time stamping 1675 * 1676 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if 1677 * parameters are invalid. 1678 */ 1679 extern int sock_tx_timestamp(struct msghdr *msg, 1680 struct sock *sk, 1681 union skb_shared_tx *shtx); 1682 1683 1684 /** 1685 * sk_eat_skb - Release a skb if it is no longer needed 1686 * @sk: socket to eat this skb from 1687 * @skb: socket buffer to eat 1688 * @copied_early: flag indicating whether DMA operations copied this data early 1689 * 1690 * This routine must be called with interrupts disabled or with the socket 1691 * locked so that the sk_buff queue operation is ok. 1692 */ 1693 #ifdef CONFIG_NET_DMA 1694 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) 1695 { 1696 __skb_unlink(skb, &sk->sk_receive_queue); 1697 if (!copied_early) 1698 __kfree_skb(skb); 1699 else 1700 __skb_queue_tail(&sk->sk_async_wait_queue, skb); 1701 } 1702 #else 1703 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) 1704 { 1705 __skb_unlink(skb, &sk->sk_receive_queue); 1706 __kfree_skb(skb); 1707 } 1708 #endif 1709 1710 static inline 1711 struct net *sock_net(const struct sock *sk) 1712 { 1713 return read_pnet(&sk->sk_net); 1714 } 1715 1716 static inline 1717 void sock_net_set(struct sock *sk, struct net *net) 1718 { 1719 write_pnet(&sk->sk_net, net); 1720 } 1721 1722 /* 1723 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace. 1724 * They should not hold a referrence to a namespace in order to allow 1725 * to stop it. 1726 * Sockets after sk_change_net should be released using sk_release_kernel 1727 */ 1728 static inline void sk_change_net(struct sock *sk, struct net *net) 1729 { 1730 put_net(sock_net(sk)); 1731 sock_net_set(sk, hold_net(net)); 1732 } 1733 1734 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 1735 { 1736 if (unlikely(skb->sk)) { 1737 struct sock *sk = skb->sk; 1738 1739 skb->destructor = NULL; 1740 skb->sk = NULL; 1741 return sk; 1742 } 1743 return NULL; 1744 } 1745 1746 extern void sock_enable_timestamp(struct sock *sk, int flag); 1747 extern int sock_get_timestamp(struct sock *, struct timeval __user *); 1748 extern int sock_get_timestampns(struct sock *, struct timespec __user *); 1749 1750 /* 1751 * Enable debug/info messages 1752 */ 1753 extern int net_msg_warn; 1754 #define NETDEBUG(fmt, args...) \ 1755 do { if (net_msg_warn) printk(fmt,##args); } while (0) 1756 1757 #define LIMIT_NETDEBUG(fmt, args...) \ 1758 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0) 1759 1760 extern __u32 sysctl_wmem_max; 1761 extern __u32 sysctl_rmem_max; 1762 1763 extern void sk_init(void); 1764 1765 extern int sysctl_optmem_max; 1766 1767 extern __u32 sysctl_wmem_default; 1768 extern __u32 sysctl_rmem_default; 1769 1770 #endif /* _SOCK_H */ 1771