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