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