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, <bir7@leland.Stanford.Edu> 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/config.h> 44 #include <linux/list.h> 45 #include <linux/timer.h> 46 #include <linux/cache.h> 47 #include <linux/module.h> 48 #include <linux/netdevice.h> 49 #include <linux/skbuff.h> /* struct sk_buff */ 50 #include <linux/security.h> 51 52 #include <linux/filter.h> 53 54 #include <asm/atomic.h> 55 #include <net/dst.h> 56 #include <net/checksum.h> 57 58 /* 59 * This structure really needs to be cleaned up. 60 * Most of it is for TCP, and not used by any of 61 * the other protocols. 62 */ 63 64 /* Define this to get the SOCK_DBG debugging facility. */ 65 #define SOCK_DEBUGGING 66 #ifdef SOCK_DEBUGGING 67 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 68 printk(KERN_DEBUG msg); } while (0) 69 #else 70 #define SOCK_DEBUG(sk, msg...) do { } while (0) 71 #endif 72 73 /* This is the per-socket lock. The spinlock provides a synchronization 74 * between user contexts and software interrupt processing, whereas the 75 * mini-semaphore synchronizes multiple users amongst themselves. 76 */ 77 struct sock_iocb; 78 typedef struct { 79 spinlock_t slock; 80 struct sock_iocb *owner; 81 wait_queue_head_t wq; 82 } socket_lock_t; 83 84 #define sock_lock_init(__sk) \ 85 do { spin_lock_init(&((__sk)->sk_lock.slock)); \ 86 (__sk)->sk_lock.owner = NULL; \ 87 init_waitqueue_head(&((__sk)->sk_lock.wq)); \ 88 } while(0) 89 90 struct sock; 91 92 /** 93 * struct sock_common - minimal network layer representation of sockets 94 * @skc_family: network address family 95 * @skc_state: Connection state 96 * @skc_reuse: %SO_REUSEADDR setting 97 * @skc_bound_dev_if: bound device index if != 0 98 * @skc_node: main hash linkage for various protocol lookup tables 99 * @skc_bind_node: bind hash linkage for various protocol lookup tables 100 * @skc_refcnt: reference count 101 * 102 * This is the minimal network layer representation of sockets, the header 103 * for struct sock and struct tcp_tw_bucket. 104 */ 105 struct sock_common { 106 unsigned short skc_family; 107 volatile unsigned char skc_state; 108 unsigned char skc_reuse; 109 int skc_bound_dev_if; 110 struct hlist_node skc_node; 111 struct hlist_node skc_bind_node; 112 atomic_t skc_refcnt; 113 }; 114 115 /** 116 * struct sock - network layer representation of sockets 117 * @__sk_common: shared layout with tcp_tw_bucket 118 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 119 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 120 * @sk_lock: synchronizer 121 * @sk_rcvbuf: size of receive buffer in bytes 122 * @sk_sleep: sock wait queue 123 * @sk_dst_cache: destination cache 124 * @sk_dst_lock: destination cache lock 125 * @sk_policy: flow policy 126 * @sk_rmem_alloc: receive queue bytes committed 127 * @sk_receive_queue: incoming packets 128 * @sk_wmem_alloc: transmit queue bytes committed 129 * @sk_write_queue: Packet sending queue 130 * @sk_omem_alloc: "o" is "option" or "other" 131 * @sk_wmem_queued: persistent queue size 132 * @sk_forward_alloc: space allocated forward 133 * @sk_allocation: allocation mode 134 * @sk_sndbuf: size of send buffer in bytes 135 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings 136 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets 137 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 138 * @sk_lingertime: %SO_LINGER l_linger setting 139 * @sk_hashent: hash entry in several tables (e.g. tcp_ehash) 140 * @sk_backlog: always used with the per-socket spinlock held 141 * @sk_callback_lock: used with the callbacks in the end of this struct 142 * @sk_error_queue: rarely used 143 * @sk_prot: protocol handlers inside a network family 144 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance) 145 * @sk_err: last error 146 * @sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out' 147 * @sk_ack_backlog: current listen backlog 148 * @sk_max_ack_backlog: listen backlog set in listen() 149 * @sk_priority: %SO_PRIORITY setting 150 * @sk_type: socket type (%SOCK_STREAM, etc) 151 * @sk_protocol: which protocol this socket belongs in this network family 152 * @sk_peercred: %SO_PEERCRED setting 153 * @sk_rcvlowat: %SO_RCVLOWAT setting 154 * @sk_rcvtimeo: %SO_RCVTIMEO setting 155 * @sk_sndtimeo: %SO_SNDTIMEO setting 156 * @sk_filter: socket filtering instructions 157 * @sk_protinfo: private area, net family specific, when not using slab 158 * @sk_timer: sock cleanup timer 159 * @sk_stamp: time stamp of last packet received 160 * @sk_socket: Identd and reporting IO signals 161 * @sk_user_data: RPC layer private data 162 * @sk_sndmsg_page: cached page for sendmsg 163 * @sk_sndmsg_off: cached offset for sendmsg 164 * @sk_send_head: front of stuff to transmit 165 * @sk_security: used by security modules 166 * @sk_write_pending: a write to stream socket waits to start 167 * @sk_state_change: callback to indicate change in the state of the sock 168 * @sk_data_ready: callback to indicate there is data to be processed 169 * @sk_write_space: callback to indicate there is bf sending space available 170 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 171 * @sk_backlog_rcv: callback to process the backlog 172 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 173 */ 174 struct sock { 175 /* 176 * Now struct tcp_tw_bucket also uses sock_common, so please just 177 * don't add nothing before this first member (__sk_common) --acme 178 */ 179 struct sock_common __sk_common; 180 #define sk_family __sk_common.skc_family 181 #define sk_state __sk_common.skc_state 182 #define sk_reuse __sk_common.skc_reuse 183 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 184 #define sk_node __sk_common.skc_node 185 #define sk_bind_node __sk_common.skc_bind_node 186 #define sk_refcnt __sk_common.skc_refcnt 187 unsigned char sk_shutdown : 2, 188 sk_no_check : 2, 189 sk_userlocks : 4; 190 unsigned char sk_protocol; 191 unsigned short sk_type; 192 int sk_rcvbuf; 193 socket_lock_t sk_lock; 194 wait_queue_head_t *sk_sleep; 195 struct dst_entry *sk_dst_cache; 196 struct xfrm_policy *sk_policy[2]; 197 rwlock_t sk_dst_lock; 198 atomic_t sk_rmem_alloc; 199 atomic_t sk_wmem_alloc; 200 atomic_t sk_omem_alloc; 201 struct sk_buff_head sk_receive_queue; 202 struct sk_buff_head sk_write_queue; 203 int sk_wmem_queued; 204 int sk_forward_alloc; 205 unsigned int sk_allocation; 206 int sk_sndbuf; 207 int sk_route_caps; 208 int sk_hashent; 209 unsigned long sk_flags; 210 unsigned long sk_lingertime; 211 /* 212 * The backlog queue is special, it is always used with 213 * the per-socket spinlock held and requires low latency 214 * access. Therefore we special case it's implementation. 215 */ 216 struct { 217 struct sk_buff *head; 218 struct sk_buff *tail; 219 } sk_backlog; 220 struct sk_buff_head sk_error_queue; 221 struct proto *sk_prot; 222 struct proto *sk_prot_creator; 223 rwlock_t sk_callback_lock; 224 int sk_err, 225 sk_err_soft; 226 unsigned short sk_ack_backlog; 227 unsigned short sk_max_ack_backlog; 228 __u32 sk_priority; 229 struct ucred sk_peercred; 230 int sk_rcvlowat; 231 long sk_rcvtimeo; 232 long sk_sndtimeo; 233 struct sk_filter *sk_filter; 234 void *sk_protinfo; 235 struct timer_list sk_timer; 236 struct timeval sk_stamp; 237 struct socket *sk_socket; 238 void *sk_user_data; 239 struct page *sk_sndmsg_page; 240 struct sk_buff *sk_send_head; 241 __u32 sk_sndmsg_off; 242 int sk_write_pending; 243 void *sk_security; 244 void (*sk_state_change)(struct sock *sk); 245 void (*sk_data_ready)(struct sock *sk, int bytes); 246 void (*sk_write_space)(struct sock *sk); 247 void (*sk_error_report)(struct sock *sk); 248 int (*sk_backlog_rcv)(struct sock *sk, 249 struct sk_buff *skb); 250 void (*sk_destruct)(struct sock *sk); 251 }; 252 253 /* 254 * Hashed lists helper routines 255 */ 256 static inline struct sock *__sk_head(struct hlist_head *head) 257 { 258 return hlist_entry(head->first, struct sock, sk_node); 259 } 260 261 static inline struct sock *sk_head(struct hlist_head *head) 262 { 263 return hlist_empty(head) ? NULL : __sk_head(head); 264 } 265 266 static inline struct sock *sk_next(struct sock *sk) 267 { 268 return sk->sk_node.next ? 269 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 270 } 271 272 static inline int sk_unhashed(struct sock *sk) 273 { 274 return hlist_unhashed(&sk->sk_node); 275 } 276 277 static inline int sk_hashed(struct sock *sk) 278 { 279 return sk->sk_node.pprev != NULL; 280 } 281 282 static __inline__ void sk_node_init(struct hlist_node *node) 283 { 284 node->pprev = NULL; 285 } 286 287 static __inline__ void __sk_del_node(struct sock *sk) 288 { 289 __hlist_del(&sk->sk_node); 290 } 291 292 static __inline__ int __sk_del_node_init(struct sock *sk) 293 { 294 if (sk_hashed(sk)) { 295 __sk_del_node(sk); 296 sk_node_init(&sk->sk_node); 297 return 1; 298 } 299 return 0; 300 } 301 302 /* Grab socket reference count. This operation is valid only 303 when sk is ALREADY grabbed f.e. it is found in hash table 304 or a list and the lookup is made under lock preventing hash table 305 modifications. 306 */ 307 308 static inline void sock_hold(struct sock *sk) 309 { 310 atomic_inc(&sk->sk_refcnt); 311 } 312 313 /* Ungrab socket in the context, which assumes that socket refcnt 314 cannot hit zero, f.e. it is true in context of any socketcall. 315 */ 316 static inline void __sock_put(struct sock *sk) 317 { 318 atomic_dec(&sk->sk_refcnt); 319 } 320 321 static __inline__ int sk_del_node_init(struct sock *sk) 322 { 323 int rc = __sk_del_node_init(sk); 324 325 if (rc) { 326 /* paranoid for a while -acme */ 327 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 328 __sock_put(sk); 329 } 330 return rc; 331 } 332 333 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list) 334 { 335 hlist_add_head(&sk->sk_node, list); 336 } 337 338 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list) 339 { 340 sock_hold(sk); 341 __sk_add_node(sk, list); 342 } 343 344 static __inline__ void __sk_del_bind_node(struct sock *sk) 345 { 346 __hlist_del(&sk->sk_bind_node); 347 } 348 349 static __inline__ void sk_add_bind_node(struct sock *sk, 350 struct hlist_head *list) 351 { 352 hlist_add_head(&sk->sk_bind_node, list); 353 } 354 355 #define sk_for_each(__sk, node, list) \ 356 hlist_for_each_entry(__sk, node, list, sk_node) 357 #define sk_for_each_from(__sk, node) \ 358 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ 359 hlist_for_each_entry_from(__sk, node, sk_node) 360 #define sk_for_each_continue(__sk, node) \ 361 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ 362 hlist_for_each_entry_continue(__sk, node, sk_node) 363 #define sk_for_each_safe(__sk, node, tmp, list) \ 364 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node) 365 #define sk_for_each_bound(__sk, node, list) \ 366 hlist_for_each_entry(__sk, node, list, sk_bind_node) 367 368 /* Sock flags */ 369 enum sock_flags { 370 SOCK_DEAD, 371 SOCK_DONE, 372 SOCK_URGINLINE, 373 SOCK_KEEPOPEN, 374 SOCK_LINGER, 375 SOCK_DESTROY, 376 SOCK_BROADCAST, 377 SOCK_TIMESTAMP, 378 SOCK_ZAPPED, 379 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 380 SOCK_DBG, /* %SO_DEBUG setting */ 381 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 382 SOCK_NO_LARGESEND, /* whether to sent large segments or not */ 383 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 384 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 385 }; 386 387 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 388 { 389 __set_bit(flag, &sk->sk_flags); 390 } 391 392 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 393 { 394 __clear_bit(flag, &sk->sk_flags); 395 } 396 397 static inline int sock_flag(struct sock *sk, enum sock_flags flag) 398 { 399 return test_bit(flag, &sk->sk_flags); 400 } 401 402 static inline void sk_acceptq_removed(struct sock *sk) 403 { 404 sk->sk_ack_backlog--; 405 } 406 407 static inline void sk_acceptq_added(struct sock *sk) 408 { 409 sk->sk_ack_backlog++; 410 } 411 412 static inline int sk_acceptq_is_full(struct sock *sk) 413 { 414 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 415 } 416 417 /* 418 * Compute minimal free write space needed to queue new packets. 419 */ 420 static inline int sk_stream_min_wspace(struct sock *sk) 421 { 422 return sk->sk_wmem_queued / 2; 423 } 424 425 static inline int sk_stream_wspace(struct sock *sk) 426 { 427 return sk->sk_sndbuf - sk->sk_wmem_queued; 428 } 429 430 extern void sk_stream_write_space(struct sock *sk); 431 432 static inline int sk_stream_memory_free(struct sock *sk) 433 { 434 return sk->sk_wmem_queued < sk->sk_sndbuf; 435 } 436 437 extern void sk_stream_rfree(struct sk_buff *skb); 438 439 static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk) 440 { 441 skb->sk = sk; 442 skb->destructor = sk_stream_rfree; 443 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 444 sk->sk_forward_alloc -= skb->truesize; 445 } 446 447 static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb) 448 { 449 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 450 sk->sk_wmem_queued -= skb->truesize; 451 sk->sk_forward_alloc += skb->truesize; 452 __kfree_skb(skb); 453 } 454 455 /* The per-socket spinlock must be held here. */ 456 #define sk_add_backlog(__sk, __skb) \ 457 do { if (!(__sk)->sk_backlog.tail) { \ 458 (__sk)->sk_backlog.head = \ 459 (__sk)->sk_backlog.tail = (__skb); \ 460 } else { \ 461 ((__sk)->sk_backlog.tail)->next = (__skb); \ 462 (__sk)->sk_backlog.tail = (__skb); \ 463 } \ 464 (__skb)->next = NULL; \ 465 } while(0) 466 467 #define sk_wait_event(__sk, __timeo, __condition) \ 468 ({ int rc; \ 469 release_sock(__sk); \ 470 rc = __condition; \ 471 if (!rc) { \ 472 *(__timeo) = schedule_timeout(*(__timeo)); \ 473 rc = __condition; \ 474 } \ 475 lock_sock(__sk); \ 476 rc; \ 477 }) 478 479 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 480 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 481 extern void sk_stream_wait_close(struct sock *sk, long timeo_p); 482 extern int sk_stream_error(struct sock *sk, int flags, int err); 483 extern void sk_stream_kill_queues(struct sock *sk); 484 485 extern int sk_wait_data(struct sock *sk, long *timeo); 486 487 /* Networking protocol blocks we attach to sockets. 488 * socket layer -> transport layer interface 489 * transport -> network interface is defined by struct inet_proto 490 */ 491 struct proto { 492 void (*close)(struct sock *sk, 493 long timeout); 494 int (*connect)(struct sock *sk, 495 struct sockaddr *uaddr, 496 int addr_len); 497 int (*disconnect)(struct sock *sk, int flags); 498 499 struct sock * (*accept) (struct sock *sk, int flags, int *err); 500 501 int (*ioctl)(struct sock *sk, int cmd, 502 unsigned long arg); 503 int (*init)(struct sock *sk); 504 int (*destroy)(struct sock *sk); 505 void (*shutdown)(struct sock *sk, int how); 506 int (*setsockopt)(struct sock *sk, int level, 507 int optname, char __user *optval, 508 int optlen); 509 int (*getsockopt)(struct sock *sk, int level, 510 int optname, char __user *optval, 511 int __user *option); 512 int (*sendmsg)(struct kiocb *iocb, struct sock *sk, 513 struct msghdr *msg, size_t len); 514 int (*recvmsg)(struct kiocb *iocb, struct sock *sk, 515 struct msghdr *msg, 516 size_t len, int noblock, int flags, 517 int *addr_len); 518 int (*sendpage)(struct sock *sk, struct page *page, 519 int offset, size_t size, int flags); 520 int (*bind)(struct sock *sk, 521 struct sockaddr *uaddr, int addr_len); 522 523 int (*backlog_rcv) (struct sock *sk, 524 struct sk_buff *skb); 525 526 /* Keeping track of sk's, looking them up, and port selection methods. */ 527 void (*hash)(struct sock *sk); 528 void (*unhash)(struct sock *sk); 529 int (*get_port)(struct sock *sk, unsigned short snum); 530 531 /* Memory pressure */ 532 void (*enter_memory_pressure)(void); 533 atomic_t *memory_allocated; /* Current allocated memory. */ 534 atomic_t *sockets_allocated; /* Current number of sockets. */ 535 /* 536 * Pressure flag: try to collapse. 537 * Technical note: it is used by multiple contexts non atomically. 538 * All the sk_stream_mem_schedule() is of this nature: accounting 539 * is strict, actions are advisory and have some latency. 540 */ 541 int *memory_pressure; 542 int *sysctl_mem; 543 int *sysctl_wmem; 544 int *sysctl_rmem; 545 int max_header; 546 547 kmem_cache_t *slab; 548 unsigned int obj_size; 549 550 struct module *owner; 551 552 char name[32]; 553 554 struct list_head node; 555 556 struct { 557 int inuse; 558 u8 __pad[SMP_CACHE_BYTES - sizeof(int)]; 559 } stats[NR_CPUS]; 560 }; 561 562 extern int proto_register(struct proto *prot, int alloc_slab); 563 extern void proto_unregister(struct proto *prot); 564 565 /* Called with local bh disabled */ 566 static __inline__ void sock_prot_inc_use(struct proto *prot) 567 { 568 prot->stats[smp_processor_id()].inuse++; 569 } 570 571 static __inline__ void sock_prot_dec_use(struct proto *prot) 572 { 573 prot->stats[smp_processor_id()].inuse--; 574 } 575 576 /* About 10 seconds */ 577 #define SOCK_DESTROY_TIME (10*HZ) 578 579 /* Sockets 0-1023 can't be bound to unless you are superuser */ 580 #define PROT_SOCK 1024 581 582 #define SHUTDOWN_MASK 3 583 #define RCV_SHUTDOWN 1 584 #define SEND_SHUTDOWN 2 585 586 #define SOCK_SNDBUF_LOCK 1 587 #define SOCK_RCVBUF_LOCK 2 588 #define SOCK_BINDADDR_LOCK 4 589 #define SOCK_BINDPORT_LOCK 8 590 591 /* sock_iocb: used to kick off async processing of socket ios */ 592 struct sock_iocb { 593 struct list_head list; 594 595 int flags; 596 int size; 597 struct socket *sock; 598 struct sock *sk; 599 struct scm_cookie *scm; 600 struct msghdr *msg, async_msg; 601 struct iovec async_iov; 602 struct kiocb *kiocb; 603 }; 604 605 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb) 606 { 607 return (struct sock_iocb *)iocb->private; 608 } 609 610 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si) 611 { 612 return si->kiocb; 613 } 614 615 struct socket_alloc { 616 struct socket socket; 617 struct inode vfs_inode; 618 }; 619 620 static inline struct socket *SOCKET_I(struct inode *inode) 621 { 622 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 623 } 624 625 static inline struct inode *SOCK_INODE(struct socket *socket) 626 { 627 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 628 } 629 630 extern void __sk_stream_mem_reclaim(struct sock *sk); 631 extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind); 632 633 #define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE) 634 635 static inline int sk_stream_pages(int amt) 636 { 637 return (amt + SK_STREAM_MEM_QUANTUM - 1) / SK_STREAM_MEM_QUANTUM; 638 } 639 640 static inline void sk_stream_mem_reclaim(struct sock *sk) 641 { 642 if (sk->sk_forward_alloc >= SK_STREAM_MEM_QUANTUM) 643 __sk_stream_mem_reclaim(sk); 644 } 645 646 static inline void sk_stream_writequeue_purge(struct sock *sk) 647 { 648 struct sk_buff *skb; 649 650 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) 651 sk_stream_free_skb(sk, skb); 652 sk_stream_mem_reclaim(sk); 653 } 654 655 static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb) 656 { 657 return (int)skb->truesize <= sk->sk_forward_alloc || 658 sk_stream_mem_schedule(sk, skb->truesize, 1); 659 } 660 661 /* Used by processes to "lock" a socket state, so that 662 * interrupts and bottom half handlers won't change it 663 * from under us. It essentially blocks any incoming 664 * packets, so that we won't get any new data or any 665 * packets that change the state of the socket. 666 * 667 * While locked, BH processing will add new packets to 668 * the backlog queue. This queue is processed by the 669 * owner of the socket lock right before it is released. 670 * 671 * Since ~2.3.5 it is also exclusive sleep lock serializing 672 * accesses from user process context. 673 */ 674 #define sock_owned_by_user(sk) ((sk)->sk_lock.owner) 675 676 extern void FASTCALL(lock_sock(struct sock *sk)); 677 extern void FASTCALL(release_sock(struct sock *sk)); 678 679 /* BH context may only use the following locking interface. */ 680 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 681 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 682 683 extern struct sock *sk_alloc(int family, int priority, 684 struct proto *prot, int zero_it); 685 extern void sk_free(struct sock *sk); 686 687 extern struct sk_buff *sock_wmalloc(struct sock *sk, 688 unsigned long size, int force, 689 int priority); 690 extern struct sk_buff *sock_rmalloc(struct sock *sk, 691 unsigned long size, int force, 692 int priority); 693 extern void sock_wfree(struct sk_buff *skb); 694 extern void sock_rfree(struct sk_buff *skb); 695 696 extern int sock_setsockopt(struct socket *sock, int level, 697 int op, char __user *optval, 698 int optlen); 699 700 extern int sock_getsockopt(struct socket *sock, int level, 701 int op, char __user *optval, 702 int __user *optlen); 703 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk, 704 unsigned long size, 705 int noblock, 706 int *errcode); 707 extern void *sock_kmalloc(struct sock *sk, int size, int priority); 708 extern void sock_kfree_s(struct sock *sk, void *mem, int size); 709 extern void sk_send_sigurg(struct sock *sk); 710 711 /* 712 * Functions to fill in entries in struct proto_ops when a protocol 713 * does not implement a particular function. 714 */ 715 extern int sock_no_bind(struct socket *, 716 struct sockaddr *, int); 717 extern int sock_no_connect(struct socket *, 718 struct sockaddr *, int, int); 719 extern int sock_no_socketpair(struct socket *, 720 struct socket *); 721 extern int sock_no_accept(struct socket *, 722 struct socket *, int); 723 extern int sock_no_getname(struct socket *, 724 struct sockaddr *, int *, int); 725 extern unsigned int sock_no_poll(struct file *, struct socket *, 726 struct poll_table_struct *); 727 extern int sock_no_ioctl(struct socket *, unsigned int, 728 unsigned long); 729 extern int sock_no_listen(struct socket *, int); 730 extern int sock_no_shutdown(struct socket *, int); 731 extern int sock_no_getsockopt(struct socket *, int , int, 732 char __user *, int __user *); 733 extern int sock_no_setsockopt(struct socket *, int, int, 734 char __user *, int); 735 extern int sock_no_sendmsg(struct kiocb *, struct socket *, 736 struct msghdr *, size_t); 737 extern int sock_no_recvmsg(struct kiocb *, struct socket *, 738 struct msghdr *, size_t, int); 739 extern int sock_no_mmap(struct file *file, 740 struct socket *sock, 741 struct vm_area_struct *vma); 742 extern ssize_t sock_no_sendpage(struct socket *sock, 743 struct page *page, 744 int offset, size_t size, 745 int flags); 746 747 /* 748 * Functions to fill in entries in struct proto_ops when a protocol 749 * uses the inet style. 750 */ 751 extern int sock_common_getsockopt(struct socket *sock, int level, int optname, 752 char __user *optval, int __user *optlen); 753 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock, 754 struct msghdr *msg, size_t size, int flags); 755 extern int sock_common_setsockopt(struct socket *sock, int level, int optname, 756 char __user *optval, int optlen); 757 758 extern void sk_common_release(struct sock *sk); 759 760 /* 761 * Default socket callbacks and setup code 762 */ 763 764 /* Initialise core socket variables */ 765 extern void sock_init_data(struct socket *sock, struct sock *sk); 766 767 /** 768 * sk_filter - run a packet through a socket filter 769 * @sk: sock associated with &sk_buff 770 * @skb: buffer to filter 771 * @needlock: set to 1 if the sock is not locked by caller. 772 * 773 * Run the filter code and then cut skb->data to correct size returned by 774 * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller 775 * than pkt_len we keep whole skb->data. This is the socket level 776 * wrapper to sk_run_filter. It returns 0 if the packet should 777 * be accepted or -EPERM if the packet should be tossed. 778 * 779 */ 780 781 static inline int sk_filter(struct sock *sk, struct sk_buff *skb, int needlock) 782 { 783 int err; 784 785 err = security_sock_rcv_skb(sk, skb); 786 if (err) 787 return err; 788 789 if (sk->sk_filter) { 790 struct sk_filter *filter; 791 792 if (needlock) 793 bh_lock_sock(sk); 794 795 filter = sk->sk_filter; 796 if (filter) { 797 int pkt_len = sk_run_filter(skb, filter->insns, 798 filter->len); 799 if (!pkt_len) 800 err = -EPERM; 801 else 802 skb_trim(skb, pkt_len); 803 } 804 805 if (needlock) 806 bh_unlock_sock(sk); 807 } 808 return err; 809 } 810 811 /** 812 * sk_filter_release: Release a socket filter 813 * @sk: socket 814 * @fp: filter to remove 815 * 816 * Remove a filter from a socket and release its resources. 817 */ 818 819 static inline void sk_filter_release(struct sock *sk, struct sk_filter *fp) 820 { 821 unsigned int size = sk_filter_len(fp); 822 823 atomic_sub(size, &sk->sk_omem_alloc); 824 825 if (atomic_dec_and_test(&fp->refcnt)) 826 kfree(fp); 827 } 828 829 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp) 830 { 831 atomic_inc(&fp->refcnt); 832 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc); 833 } 834 835 /* 836 * Socket reference counting postulates. 837 * 838 * * Each user of socket SHOULD hold a reference count. 839 * * Each access point to socket (an hash table bucket, reference from a list, 840 * running timer, skb in flight MUST hold a reference count. 841 * * When reference count hits 0, it means it will never increase back. 842 * * When reference count hits 0, it means that no references from 843 * outside exist to this socket and current process on current CPU 844 * is last user and may/should destroy this socket. 845 * * sk_free is called from any context: process, BH, IRQ. When 846 * it is called, socket has no references from outside -> sk_free 847 * may release descendant resources allocated by the socket, but 848 * to the time when it is called, socket is NOT referenced by any 849 * hash tables, lists etc. 850 * * Packets, delivered from outside (from network or from another process) 851 * and enqueued on receive/error queues SHOULD NOT grab reference count, 852 * when they sit in queue. Otherwise, packets will leak to hole, when 853 * socket is looked up by one cpu and unhasing is made by another CPU. 854 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 855 * (leak to backlog). Packet socket does all the processing inside 856 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 857 * use separate SMP lock, so that they are prone too. 858 */ 859 860 /* Ungrab socket and destroy it, if it was the last reference. */ 861 static inline void sock_put(struct sock *sk) 862 { 863 if (atomic_dec_and_test(&sk->sk_refcnt)) 864 sk_free(sk); 865 } 866 867 /* Detach socket from process context. 868 * Announce socket dead, detach it from wait queue and inode. 869 * Note that parent inode held reference count on this struct sock, 870 * we do not release it in this function, because protocol 871 * probably wants some additional cleanups or even continuing 872 * to work with this socket (TCP). 873 */ 874 static inline void sock_orphan(struct sock *sk) 875 { 876 write_lock_bh(&sk->sk_callback_lock); 877 sock_set_flag(sk, SOCK_DEAD); 878 sk->sk_socket = NULL; 879 sk->sk_sleep = NULL; 880 write_unlock_bh(&sk->sk_callback_lock); 881 } 882 883 static inline void sock_graft(struct sock *sk, struct socket *parent) 884 { 885 write_lock_bh(&sk->sk_callback_lock); 886 sk->sk_sleep = &parent->wait; 887 parent->sk = sk; 888 sk->sk_socket = parent; 889 write_unlock_bh(&sk->sk_callback_lock); 890 } 891 892 extern int sock_i_uid(struct sock *sk); 893 extern unsigned long sock_i_ino(struct sock *sk); 894 895 static inline struct dst_entry * 896 __sk_dst_get(struct sock *sk) 897 { 898 return sk->sk_dst_cache; 899 } 900 901 static inline struct dst_entry * 902 sk_dst_get(struct sock *sk) 903 { 904 struct dst_entry *dst; 905 906 read_lock(&sk->sk_dst_lock); 907 dst = sk->sk_dst_cache; 908 if (dst) 909 dst_hold(dst); 910 read_unlock(&sk->sk_dst_lock); 911 return dst; 912 } 913 914 static inline void 915 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 916 { 917 struct dst_entry *old_dst; 918 919 old_dst = sk->sk_dst_cache; 920 sk->sk_dst_cache = dst; 921 dst_release(old_dst); 922 } 923 924 static inline void 925 sk_dst_set(struct sock *sk, struct dst_entry *dst) 926 { 927 write_lock(&sk->sk_dst_lock); 928 __sk_dst_set(sk, dst); 929 write_unlock(&sk->sk_dst_lock); 930 } 931 932 static inline void 933 __sk_dst_reset(struct sock *sk) 934 { 935 struct dst_entry *old_dst; 936 937 old_dst = sk->sk_dst_cache; 938 sk->sk_dst_cache = NULL; 939 dst_release(old_dst); 940 } 941 942 static inline void 943 sk_dst_reset(struct sock *sk) 944 { 945 write_lock(&sk->sk_dst_lock); 946 __sk_dst_reset(sk); 947 write_unlock(&sk->sk_dst_lock); 948 } 949 950 static inline struct dst_entry * 951 __sk_dst_check(struct sock *sk, u32 cookie) 952 { 953 struct dst_entry *dst = sk->sk_dst_cache; 954 955 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) { 956 sk->sk_dst_cache = NULL; 957 dst_release(dst); 958 return NULL; 959 } 960 961 return dst; 962 } 963 964 static inline struct dst_entry * 965 sk_dst_check(struct sock *sk, u32 cookie) 966 { 967 struct dst_entry *dst = sk_dst_get(sk); 968 969 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) { 970 sk_dst_reset(sk); 971 dst_release(dst); 972 return NULL; 973 } 974 975 return dst; 976 } 977 978 static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb) 979 { 980 sk->sk_wmem_queued += skb->truesize; 981 sk->sk_forward_alloc -= skb->truesize; 982 } 983 984 static inline int skb_copy_to_page(struct sock *sk, char __user *from, 985 struct sk_buff *skb, struct page *page, 986 int off, int copy) 987 { 988 if (skb->ip_summed == CHECKSUM_NONE) { 989 int err = 0; 990 unsigned int csum = csum_and_copy_from_user(from, 991 page_address(page) + off, 992 copy, 0, &err); 993 if (err) 994 return err; 995 skb->csum = csum_block_add(skb->csum, csum, skb->len); 996 } else if (copy_from_user(page_address(page) + off, from, copy)) 997 return -EFAULT; 998 999 skb->len += copy; 1000 skb->data_len += copy; 1001 skb->truesize += copy; 1002 sk->sk_wmem_queued += copy; 1003 sk->sk_forward_alloc -= copy; 1004 return 0; 1005 } 1006 1007 /* 1008 * Queue a received datagram if it will fit. Stream and sequenced 1009 * protocols can't normally use this as they need to fit buffers in 1010 * and play with them. 1011 * 1012 * Inlined as it's very short and called for pretty much every 1013 * packet ever received. 1014 */ 1015 1016 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1017 { 1018 sock_hold(sk); 1019 skb->sk = sk; 1020 skb->destructor = sock_wfree; 1021 atomic_add(skb->truesize, &sk->sk_wmem_alloc); 1022 } 1023 1024 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1025 { 1026 skb->sk = sk; 1027 skb->destructor = sock_rfree; 1028 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1029 } 1030 1031 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer, 1032 unsigned long expires); 1033 1034 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer); 1035 1036 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1037 { 1038 int err = 0; 1039 int skb_len; 1040 1041 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces 1042 number of warnings when compiling with -W --ANK 1043 */ 1044 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 1045 (unsigned)sk->sk_rcvbuf) { 1046 err = -ENOMEM; 1047 goto out; 1048 } 1049 1050 /* It would be deadlock, if sock_queue_rcv_skb is used 1051 with socket lock! We assume that users of this 1052 function are lock free. 1053 */ 1054 err = sk_filter(sk, skb, 1); 1055 if (err) 1056 goto out; 1057 1058 skb->dev = NULL; 1059 skb_set_owner_r(skb, sk); 1060 1061 /* Cache the SKB length before we tack it onto the receive 1062 * queue. Once it is added it no longer belongs to us and 1063 * may be freed by other threads of control pulling packets 1064 * from the queue. 1065 */ 1066 skb_len = skb->len; 1067 1068 skb_queue_tail(&sk->sk_receive_queue, skb); 1069 1070 if (!sock_flag(sk, SOCK_DEAD)) 1071 sk->sk_data_ready(sk, skb_len); 1072 out: 1073 return err; 1074 } 1075 1076 static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) 1077 { 1078 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces 1079 number of warnings when compiling with -W --ANK 1080 */ 1081 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 1082 (unsigned)sk->sk_rcvbuf) 1083 return -ENOMEM; 1084 skb_set_owner_r(skb, sk); 1085 skb_queue_tail(&sk->sk_error_queue, skb); 1086 if (!sock_flag(sk, SOCK_DEAD)) 1087 sk->sk_data_ready(sk, skb->len); 1088 return 0; 1089 } 1090 1091 /* 1092 * Recover an error report and clear atomically 1093 */ 1094 1095 static inline int sock_error(struct sock *sk) 1096 { 1097 int err = xchg(&sk->sk_err, 0); 1098 return -err; 1099 } 1100 1101 static inline unsigned long sock_wspace(struct sock *sk) 1102 { 1103 int amt = 0; 1104 1105 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 1106 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 1107 if (amt < 0) 1108 amt = 0; 1109 } 1110 return amt; 1111 } 1112 1113 static inline void sk_wake_async(struct sock *sk, int how, int band) 1114 { 1115 if (sk->sk_socket && sk->sk_socket->fasync_list) 1116 sock_wake_async(sk->sk_socket, how, band); 1117 } 1118 1119 #define SOCK_MIN_SNDBUF 2048 1120 #define SOCK_MIN_RCVBUF 256 1121 1122 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 1123 { 1124 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 1125 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued / 2); 1126 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF); 1127 } 1128 } 1129 1130 static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk, 1131 int size, int mem, int gfp) 1132 { 1133 struct sk_buff *skb = alloc_skb(size + sk->sk_prot->max_header, gfp); 1134 1135 if (skb) { 1136 skb->truesize += mem; 1137 if (sk->sk_forward_alloc >= (int)skb->truesize || 1138 sk_stream_mem_schedule(sk, skb->truesize, 0)) { 1139 skb_reserve(skb, sk->sk_prot->max_header); 1140 return skb; 1141 } 1142 __kfree_skb(skb); 1143 } else { 1144 sk->sk_prot->enter_memory_pressure(); 1145 sk_stream_moderate_sndbuf(sk); 1146 } 1147 return NULL; 1148 } 1149 1150 static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk, 1151 int size, int gfp) 1152 { 1153 return sk_stream_alloc_pskb(sk, size, 0, gfp); 1154 } 1155 1156 static inline struct page *sk_stream_alloc_page(struct sock *sk) 1157 { 1158 struct page *page = NULL; 1159 1160 if (sk->sk_forward_alloc >= (int)PAGE_SIZE || 1161 sk_stream_mem_schedule(sk, PAGE_SIZE, 0)) 1162 page = alloc_pages(sk->sk_allocation, 0); 1163 else { 1164 sk->sk_prot->enter_memory_pressure(); 1165 sk_stream_moderate_sndbuf(sk); 1166 } 1167 return page; 1168 } 1169 1170 #define sk_stream_for_retrans_queue(skb, sk) \ 1171 for (skb = (sk)->sk_write_queue.next; \ 1172 (skb != (sk)->sk_send_head) && \ 1173 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \ 1174 skb = skb->next) 1175 1176 /* 1177 * Default write policy as shown to user space via poll/select/SIGIO 1178 */ 1179 static inline int sock_writeable(const struct sock *sk) 1180 { 1181 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf / 2); 1182 } 1183 1184 static inline int gfp_any(void) 1185 { 1186 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 1187 } 1188 1189 static inline long sock_rcvtimeo(const struct sock *sk, int noblock) 1190 { 1191 return noblock ? 0 : sk->sk_rcvtimeo; 1192 } 1193 1194 static inline long sock_sndtimeo(const struct sock *sk, int noblock) 1195 { 1196 return noblock ? 0 : sk->sk_sndtimeo; 1197 } 1198 1199 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 1200 { 1201 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 1202 } 1203 1204 /* Alas, with timeout socket operations are not restartable. 1205 * Compare this to poll(). 1206 */ 1207 static inline int sock_intr_errno(long timeo) 1208 { 1209 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 1210 } 1211 1212 static __inline__ void 1213 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 1214 { 1215 struct timeval *stamp = &skb->stamp; 1216 if (sock_flag(sk, SOCK_RCVTSTAMP)) { 1217 /* Race occurred between timestamp enabling and packet 1218 receiving. Fill in the current time for now. */ 1219 if (stamp->tv_sec == 0) 1220 do_gettimeofday(stamp); 1221 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval), 1222 stamp); 1223 } else 1224 sk->sk_stamp = *stamp; 1225 } 1226 1227 /** 1228 * sk_eat_skb - Release a skb if it is no longer needed 1229 * @sk: socket to eat this skb from 1230 * @skb: socket buffer to eat 1231 * 1232 * This routine must be called with interrupts disabled or with the socket 1233 * locked so that the sk_buff queue operation is ok. 1234 */ 1235 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 1236 { 1237 __skb_unlink(skb, &sk->sk_receive_queue); 1238 __kfree_skb(skb); 1239 } 1240 1241 extern void sock_enable_timestamp(struct sock *sk); 1242 extern int sock_get_timestamp(struct sock *, struct timeval __user *); 1243 1244 /* 1245 * Enable debug/info messages 1246 */ 1247 1248 #if 0 1249 #define NETDEBUG(x) do { } while (0) 1250 #define LIMIT_NETDEBUG(x) do {} while(0) 1251 #else 1252 #define NETDEBUG(x) do { x; } while (0) 1253 #define LIMIT_NETDEBUG(x) do { if (net_ratelimit()) { x; } } while(0) 1254 #endif 1255 1256 /* 1257 * Macros for sleeping on a socket. Use them like this: 1258 * 1259 * SOCK_SLEEP_PRE(sk) 1260 * if (condition) 1261 * schedule(); 1262 * SOCK_SLEEP_POST(sk) 1263 * 1264 * N.B. These are now obsolete and were, afaik, only ever used in DECnet 1265 * and when the last use of them in DECnet has gone, I'm intending to 1266 * remove them. 1267 */ 1268 1269 #define SOCK_SLEEP_PRE(sk) { struct task_struct *tsk = current; \ 1270 DECLARE_WAITQUEUE(wait, tsk); \ 1271 tsk->state = TASK_INTERRUPTIBLE; \ 1272 add_wait_queue((sk)->sk_sleep, &wait); \ 1273 release_sock(sk); 1274 1275 #define SOCK_SLEEP_POST(sk) tsk->state = TASK_RUNNING; \ 1276 remove_wait_queue((sk)->sk_sleep, &wait); \ 1277 lock_sock(sk); \ 1278 } 1279 1280 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool) 1281 { 1282 if (valbool) 1283 sock_set_flag(sk, bit); 1284 else 1285 sock_reset_flag(sk, bit); 1286 } 1287 1288 extern __u32 sysctl_wmem_max; 1289 extern __u32 sysctl_rmem_max; 1290 1291 #ifdef CONFIG_NET 1292 int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg); 1293 #else 1294 static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) 1295 { 1296 return -ENODEV; 1297 } 1298 #endif 1299 1300 #endif /* _SOCK_H */ 1301