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/hardirq.h> 44 #include <linux/kernel.h> 45 #include <linux/list.h> 46 #include <linux/list_nulls.h> 47 #include <linux/timer.h> 48 #include <linux/cache.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 #include <linux/uaccess.h> 56 57 #include <linux/filter.h> 58 #include <linux/rculist_nulls.h> 59 #include <linux/poll.h> 60 61 #include <linux/atomic.h> 62 #include <net/dst.h> 63 #include <net/checksum.h> 64 65 /* 66 * This structure really needs to be cleaned up. 67 * Most of it is for TCP, and not used by any of 68 * the other protocols. 69 */ 70 71 /* Define this to get the SOCK_DBG debugging facility. */ 72 #define SOCK_DEBUGGING 73 #ifdef SOCK_DEBUGGING 74 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 75 printk(KERN_DEBUG msg); } while (0) 76 #else 77 /* Validate arguments and do nothing */ 78 static inline __printf(2, 3) 79 void SOCK_DEBUG(struct sock *sk, const char *msg, ...) 80 { 81 } 82 #endif 83 84 /* This is the per-socket lock. The spinlock provides a synchronization 85 * between user contexts and software interrupt processing, whereas the 86 * mini-semaphore synchronizes multiple users amongst themselves. 87 */ 88 typedef struct { 89 spinlock_t slock; 90 int owned; 91 wait_queue_head_t wq; 92 /* 93 * We express the mutex-alike socket_lock semantics 94 * to the lock validator by explicitly managing 95 * the slock as a lock variant (in addition to 96 * the slock itself): 97 */ 98 #ifdef CONFIG_DEBUG_LOCK_ALLOC 99 struct lockdep_map dep_map; 100 #endif 101 } socket_lock_t; 102 103 struct sock; 104 struct proto; 105 struct net; 106 107 /** 108 * struct sock_common - minimal network layer representation of sockets 109 * @skc_daddr: Foreign IPv4 addr 110 * @skc_rcv_saddr: Bound local IPv4 addr 111 * @skc_hash: hash value used with various protocol lookup tables 112 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 113 * @skc_family: network address family 114 * @skc_state: Connection state 115 * @skc_reuse: %SO_REUSEADDR setting 116 * @skc_bound_dev_if: bound device index if != 0 117 * @skc_bind_node: bind hash linkage for various protocol lookup tables 118 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 119 * @skc_prot: protocol handlers inside a network family 120 * @skc_net: reference to the network namespace of this socket 121 * @skc_node: main hash linkage for various protocol lookup tables 122 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 123 * @skc_tx_queue_mapping: tx queue number for this connection 124 * @skc_refcnt: reference count 125 * 126 * This is the minimal network layer representation of sockets, the header 127 * for struct sock and struct inet_timewait_sock. 128 */ 129 struct sock_common { 130 /* skc_daddr and skc_rcv_saddr must be grouped : 131 * cf INET_MATCH() and INET_TW_MATCH() 132 */ 133 __be32 skc_daddr; 134 __be32 skc_rcv_saddr; 135 136 union { 137 unsigned int skc_hash; 138 __u16 skc_u16hashes[2]; 139 }; 140 unsigned short skc_family; 141 volatile unsigned char skc_state; 142 unsigned char skc_reuse; 143 int skc_bound_dev_if; 144 union { 145 struct hlist_node skc_bind_node; 146 struct hlist_nulls_node skc_portaddr_node; 147 }; 148 struct proto *skc_prot; 149 #ifdef CONFIG_NET_NS 150 struct net *skc_net; 151 #endif 152 /* 153 * fields between dontcopy_begin/dontcopy_end 154 * are not copied in sock_copy() 155 */ 156 /* private: */ 157 int skc_dontcopy_begin[0]; 158 /* public: */ 159 union { 160 struct hlist_node skc_node; 161 struct hlist_nulls_node skc_nulls_node; 162 }; 163 int skc_tx_queue_mapping; 164 atomic_t skc_refcnt; 165 /* private: */ 166 int skc_dontcopy_end[0]; 167 /* public: */ 168 }; 169 170 /** 171 * struct sock - network layer representation of sockets 172 * @__sk_common: shared layout with inet_timewait_sock 173 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 174 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 175 * @sk_lock: synchronizer 176 * @sk_rcvbuf: size of receive buffer in bytes 177 * @sk_wq: sock wait queue and async head 178 * @sk_dst_cache: destination cache 179 * @sk_dst_lock: destination cache lock 180 * @sk_policy: flow policy 181 * @sk_receive_queue: incoming packets 182 * @sk_wmem_alloc: transmit queue bytes committed 183 * @sk_write_queue: Packet sending queue 184 * @sk_async_wait_queue: DMA copied packets 185 * @sk_omem_alloc: "o" is "option" or "other" 186 * @sk_wmem_queued: persistent queue size 187 * @sk_forward_alloc: space allocated forward 188 * @sk_allocation: allocation mode 189 * @sk_sndbuf: size of send buffer in bytes 190 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 191 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 192 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets 193 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 194 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 195 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 196 * @sk_gso_max_size: Maximum GSO segment size to build 197 * @sk_lingertime: %SO_LINGER l_linger setting 198 * @sk_backlog: always used with the per-socket spinlock held 199 * @sk_callback_lock: used with the callbacks in the end of this struct 200 * @sk_error_queue: rarely used 201 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 202 * IPV6_ADDRFORM for instance) 203 * @sk_err: last error 204 * @sk_err_soft: errors that don't cause failure but are the cause of a 205 * persistent failure not just 'timed out' 206 * @sk_drops: raw/udp drops counter 207 * @sk_ack_backlog: current listen backlog 208 * @sk_max_ack_backlog: listen backlog set in listen() 209 * @sk_priority: %SO_PRIORITY setting 210 * @sk_type: socket type (%SOCK_STREAM, etc) 211 * @sk_protocol: which protocol this socket belongs in this network family 212 * @sk_peer_pid: &struct pid for this socket's peer 213 * @sk_peer_cred: %SO_PEERCRED setting 214 * @sk_rcvlowat: %SO_RCVLOWAT setting 215 * @sk_rcvtimeo: %SO_RCVTIMEO setting 216 * @sk_sndtimeo: %SO_SNDTIMEO setting 217 * @sk_rxhash: flow hash received from netif layer 218 * @sk_filter: socket filtering instructions 219 * @sk_protinfo: private area, net family specific, when not using slab 220 * @sk_timer: sock cleanup timer 221 * @sk_stamp: time stamp of last packet received 222 * @sk_socket: Identd and reporting IO signals 223 * @sk_user_data: RPC layer private data 224 * @sk_sndmsg_page: cached page for sendmsg 225 * @sk_sndmsg_off: cached offset for sendmsg 226 * @sk_send_head: front of stuff to transmit 227 * @sk_security: used by security modules 228 * @sk_mark: generic packet mark 229 * @sk_classid: this socket's cgroup classid 230 * @sk_write_pending: a write to stream socket waits to start 231 * @sk_state_change: callback to indicate change in the state of the sock 232 * @sk_data_ready: callback to indicate there is data to be processed 233 * @sk_write_space: callback to indicate there is bf sending space available 234 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 235 * @sk_backlog_rcv: callback to process the backlog 236 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 237 */ 238 struct sock { 239 /* 240 * Now struct inet_timewait_sock also uses sock_common, so please just 241 * don't add nothing before this first member (__sk_common) --acme 242 */ 243 struct sock_common __sk_common; 244 #define sk_node __sk_common.skc_node 245 #define sk_nulls_node __sk_common.skc_nulls_node 246 #define sk_refcnt __sk_common.skc_refcnt 247 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 248 249 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 250 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 251 #define sk_hash __sk_common.skc_hash 252 #define sk_family __sk_common.skc_family 253 #define sk_state __sk_common.skc_state 254 #define sk_reuse __sk_common.skc_reuse 255 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 256 #define sk_bind_node __sk_common.skc_bind_node 257 #define sk_prot __sk_common.skc_prot 258 #define sk_net __sk_common.skc_net 259 socket_lock_t sk_lock; 260 struct sk_buff_head sk_receive_queue; 261 /* 262 * The backlog queue is special, it is always used with 263 * the per-socket spinlock held and requires low latency 264 * access. Therefore we special case it's implementation. 265 * Note : rmem_alloc is in this structure to fill a hole 266 * on 64bit arches, not because its logically part of 267 * backlog. 268 */ 269 struct { 270 atomic_t rmem_alloc; 271 int len; 272 struct sk_buff *head; 273 struct sk_buff *tail; 274 } sk_backlog; 275 #define sk_rmem_alloc sk_backlog.rmem_alloc 276 int sk_forward_alloc; 277 #ifdef CONFIG_RPS 278 __u32 sk_rxhash; 279 #endif 280 atomic_t sk_drops; 281 int sk_rcvbuf; 282 283 struct sk_filter __rcu *sk_filter; 284 struct socket_wq __rcu *sk_wq; 285 286 #ifdef CONFIG_NET_DMA 287 struct sk_buff_head sk_async_wait_queue; 288 #endif 289 290 #ifdef CONFIG_XFRM 291 struct xfrm_policy *sk_policy[2]; 292 #endif 293 unsigned long sk_flags; 294 struct dst_entry *sk_dst_cache; 295 spinlock_t sk_dst_lock; 296 atomic_t sk_wmem_alloc; 297 atomic_t sk_omem_alloc; 298 int sk_sndbuf; 299 struct sk_buff_head sk_write_queue; 300 kmemcheck_bitfield_begin(flags); 301 unsigned int sk_shutdown : 2, 302 sk_no_check : 2, 303 sk_userlocks : 4, 304 sk_protocol : 8, 305 sk_type : 16; 306 kmemcheck_bitfield_end(flags); 307 int sk_wmem_queued; 308 gfp_t sk_allocation; 309 int sk_route_caps; 310 int sk_route_nocaps; 311 int sk_gso_type; 312 unsigned int sk_gso_max_size; 313 int sk_rcvlowat; 314 unsigned long sk_lingertime; 315 struct sk_buff_head sk_error_queue; 316 struct proto *sk_prot_creator; 317 rwlock_t sk_callback_lock; 318 int sk_err, 319 sk_err_soft; 320 unsigned short sk_ack_backlog; 321 unsigned short sk_max_ack_backlog; 322 __u32 sk_priority; 323 struct pid *sk_peer_pid; 324 const struct cred *sk_peer_cred; 325 long sk_rcvtimeo; 326 long sk_sndtimeo; 327 void *sk_protinfo; 328 struct timer_list sk_timer; 329 ktime_t sk_stamp; 330 struct socket *sk_socket; 331 void *sk_user_data; 332 struct page *sk_sndmsg_page; 333 struct sk_buff *sk_send_head; 334 __u32 sk_sndmsg_off; 335 int sk_write_pending; 336 #ifdef CONFIG_SECURITY 337 void *sk_security; 338 #endif 339 __u32 sk_mark; 340 u32 sk_classid; 341 void (*sk_state_change)(struct sock *sk); 342 void (*sk_data_ready)(struct sock *sk, int bytes); 343 void (*sk_write_space)(struct sock *sk); 344 void (*sk_error_report)(struct sock *sk); 345 int (*sk_backlog_rcv)(struct sock *sk, 346 struct sk_buff *skb); 347 void (*sk_destruct)(struct sock *sk); 348 }; 349 350 /* 351 * Hashed lists helper routines 352 */ 353 static inline struct sock *sk_entry(const struct hlist_node *node) 354 { 355 return hlist_entry(node, struct sock, sk_node); 356 } 357 358 static inline struct sock *__sk_head(const struct hlist_head *head) 359 { 360 return hlist_entry(head->first, struct sock, sk_node); 361 } 362 363 static inline struct sock *sk_head(const struct hlist_head *head) 364 { 365 return hlist_empty(head) ? NULL : __sk_head(head); 366 } 367 368 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 369 { 370 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 371 } 372 373 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 374 { 375 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 376 } 377 378 static inline struct sock *sk_next(const struct sock *sk) 379 { 380 return sk->sk_node.next ? 381 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 382 } 383 384 static inline struct sock *sk_nulls_next(const struct sock *sk) 385 { 386 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 387 hlist_nulls_entry(sk->sk_nulls_node.next, 388 struct sock, sk_nulls_node) : 389 NULL; 390 } 391 392 static inline int sk_unhashed(const struct sock *sk) 393 { 394 return hlist_unhashed(&sk->sk_node); 395 } 396 397 static inline int sk_hashed(const struct sock *sk) 398 { 399 return !sk_unhashed(sk); 400 } 401 402 static __inline__ void sk_node_init(struct hlist_node *node) 403 { 404 node->pprev = NULL; 405 } 406 407 static __inline__ void sk_nulls_node_init(struct hlist_nulls_node *node) 408 { 409 node->pprev = NULL; 410 } 411 412 static __inline__ void __sk_del_node(struct sock *sk) 413 { 414 __hlist_del(&sk->sk_node); 415 } 416 417 /* NB: equivalent to hlist_del_init_rcu */ 418 static __inline__ int __sk_del_node_init(struct sock *sk) 419 { 420 if (sk_hashed(sk)) { 421 __sk_del_node(sk); 422 sk_node_init(&sk->sk_node); 423 return 1; 424 } 425 return 0; 426 } 427 428 /* Grab socket reference count. This operation is valid only 429 when sk is ALREADY grabbed f.e. it is found in hash table 430 or a list and the lookup is made under lock preventing hash table 431 modifications. 432 */ 433 434 static inline void sock_hold(struct sock *sk) 435 { 436 atomic_inc(&sk->sk_refcnt); 437 } 438 439 /* Ungrab socket in the context, which assumes that socket refcnt 440 cannot hit zero, f.e. it is true in context of any socketcall. 441 */ 442 static inline void __sock_put(struct sock *sk) 443 { 444 atomic_dec(&sk->sk_refcnt); 445 } 446 447 static __inline__ int sk_del_node_init(struct sock *sk) 448 { 449 int rc = __sk_del_node_init(sk); 450 451 if (rc) { 452 /* paranoid for a while -acme */ 453 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 454 __sock_put(sk); 455 } 456 return rc; 457 } 458 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 459 460 static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk) 461 { 462 if (sk_hashed(sk)) { 463 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 464 return 1; 465 } 466 return 0; 467 } 468 469 static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk) 470 { 471 int rc = __sk_nulls_del_node_init_rcu(sk); 472 473 if (rc) { 474 /* paranoid for a while -acme */ 475 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 476 __sock_put(sk); 477 } 478 return rc; 479 } 480 481 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list) 482 { 483 hlist_add_head(&sk->sk_node, list); 484 } 485 486 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list) 487 { 488 sock_hold(sk); 489 __sk_add_node(sk, list); 490 } 491 492 static __inline__ void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 493 { 494 sock_hold(sk); 495 hlist_add_head_rcu(&sk->sk_node, list); 496 } 497 498 static __inline__ void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 499 { 500 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 501 } 502 503 static __inline__ void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 504 { 505 sock_hold(sk); 506 __sk_nulls_add_node_rcu(sk, list); 507 } 508 509 static __inline__ void __sk_del_bind_node(struct sock *sk) 510 { 511 __hlist_del(&sk->sk_bind_node); 512 } 513 514 static __inline__ void sk_add_bind_node(struct sock *sk, 515 struct hlist_head *list) 516 { 517 hlist_add_head(&sk->sk_bind_node, list); 518 } 519 520 #define sk_for_each(__sk, node, list) \ 521 hlist_for_each_entry(__sk, node, list, sk_node) 522 #define sk_for_each_rcu(__sk, node, list) \ 523 hlist_for_each_entry_rcu(__sk, node, list, sk_node) 524 #define sk_nulls_for_each(__sk, node, list) \ 525 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 526 #define sk_nulls_for_each_rcu(__sk, node, list) \ 527 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 528 #define sk_for_each_from(__sk, node) \ 529 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ 530 hlist_for_each_entry_from(__sk, node, sk_node) 531 #define sk_nulls_for_each_from(__sk, node) \ 532 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 533 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 534 #define sk_for_each_safe(__sk, node, tmp, list) \ 535 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node) 536 #define sk_for_each_bound(__sk, node, list) \ 537 hlist_for_each_entry(__sk, node, list, sk_bind_node) 538 539 /* Sock flags */ 540 enum sock_flags { 541 SOCK_DEAD, 542 SOCK_DONE, 543 SOCK_URGINLINE, 544 SOCK_KEEPOPEN, 545 SOCK_LINGER, 546 SOCK_DESTROY, 547 SOCK_BROADCAST, 548 SOCK_TIMESTAMP, 549 SOCK_ZAPPED, 550 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 551 SOCK_DBG, /* %SO_DEBUG setting */ 552 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 553 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 554 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 555 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 556 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */ 557 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */ 558 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */ 559 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 560 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */ 561 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */ 562 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */ 563 SOCK_FASYNC, /* fasync() active */ 564 SOCK_RXQ_OVFL, 565 SOCK_ZEROCOPY, /* buffers from userspace */ 566 }; 567 568 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 569 { 570 nsk->sk_flags = osk->sk_flags; 571 } 572 573 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 574 { 575 __set_bit(flag, &sk->sk_flags); 576 } 577 578 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 579 { 580 __clear_bit(flag, &sk->sk_flags); 581 } 582 583 static inline int sock_flag(struct sock *sk, enum sock_flags flag) 584 { 585 return test_bit(flag, &sk->sk_flags); 586 } 587 588 static inline void sk_acceptq_removed(struct sock *sk) 589 { 590 sk->sk_ack_backlog--; 591 } 592 593 static inline void sk_acceptq_added(struct sock *sk) 594 { 595 sk->sk_ack_backlog++; 596 } 597 598 static inline int sk_acceptq_is_full(struct sock *sk) 599 { 600 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 601 } 602 603 /* 604 * Compute minimal free write space needed to queue new packets. 605 */ 606 static inline int sk_stream_min_wspace(struct sock *sk) 607 { 608 return sk->sk_wmem_queued >> 1; 609 } 610 611 static inline int sk_stream_wspace(struct sock *sk) 612 { 613 return sk->sk_sndbuf - sk->sk_wmem_queued; 614 } 615 616 extern void sk_stream_write_space(struct sock *sk); 617 618 static inline int sk_stream_memory_free(struct sock *sk) 619 { 620 return sk->sk_wmem_queued < sk->sk_sndbuf; 621 } 622 623 /* OOB backlog add */ 624 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 625 { 626 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 627 skb_dst_force(skb); 628 629 if (!sk->sk_backlog.tail) 630 sk->sk_backlog.head = skb; 631 else 632 sk->sk_backlog.tail->next = skb; 633 634 sk->sk_backlog.tail = skb; 635 skb->next = NULL; 636 } 637 638 /* 639 * Take into account size of receive queue and backlog queue 640 */ 641 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb) 642 { 643 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 644 645 return qsize + skb->truesize > sk->sk_rcvbuf; 646 } 647 648 /* The per-socket spinlock must be held here. */ 649 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb) 650 { 651 if (sk_rcvqueues_full(sk, skb)) 652 return -ENOBUFS; 653 654 __sk_add_backlog(sk, skb); 655 sk->sk_backlog.len += skb->truesize; 656 return 0; 657 } 658 659 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 660 { 661 return sk->sk_backlog_rcv(sk, skb); 662 } 663 664 static inline void sock_rps_record_flow(const struct sock *sk) 665 { 666 #ifdef CONFIG_RPS 667 struct rps_sock_flow_table *sock_flow_table; 668 669 rcu_read_lock(); 670 sock_flow_table = rcu_dereference(rps_sock_flow_table); 671 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash); 672 rcu_read_unlock(); 673 #endif 674 } 675 676 static inline void sock_rps_reset_flow(const struct sock *sk) 677 { 678 #ifdef CONFIG_RPS 679 struct rps_sock_flow_table *sock_flow_table; 680 681 rcu_read_lock(); 682 sock_flow_table = rcu_dereference(rps_sock_flow_table); 683 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash); 684 rcu_read_unlock(); 685 #endif 686 } 687 688 static inline void sock_rps_save_rxhash(struct sock *sk, 689 const struct sk_buff *skb) 690 { 691 #ifdef CONFIG_RPS 692 if (unlikely(sk->sk_rxhash != skb->rxhash)) { 693 sock_rps_reset_flow(sk); 694 sk->sk_rxhash = skb->rxhash; 695 } 696 #endif 697 } 698 699 static inline void sock_rps_reset_rxhash(struct sock *sk) 700 { 701 #ifdef CONFIG_RPS 702 sock_rps_reset_flow(sk); 703 sk->sk_rxhash = 0; 704 #endif 705 } 706 707 #define sk_wait_event(__sk, __timeo, __condition) \ 708 ({ int __rc; \ 709 release_sock(__sk); \ 710 __rc = __condition; \ 711 if (!__rc) { \ 712 *(__timeo) = schedule_timeout(*(__timeo)); \ 713 } \ 714 lock_sock(__sk); \ 715 __rc = __condition; \ 716 __rc; \ 717 }) 718 719 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 720 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 721 extern void sk_stream_wait_close(struct sock *sk, long timeo_p); 722 extern int sk_stream_error(struct sock *sk, int flags, int err); 723 extern void sk_stream_kill_queues(struct sock *sk); 724 725 extern int sk_wait_data(struct sock *sk, long *timeo); 726 727 struct request_sock_ops; 728 struct timewait_sock_ops; 729 struct inet_hashinfo; 730 struct raw_hashinfo; 731 struct module; 732 733 /* Networking protocol blocks we attach to sockets. 734 * socket layer -> transport layer interface 735 * transport -> network interface is defined by struct inet_proto 736 */ 737 struct proto { 738 void (*close)(struct sock *sk, 739 long timeout); 740 int (*connect)(struct sock *sk, 741 struct sockaddr *uaddr, 742 int addr_len); 743 int (*disconnect)(struct sock *sk, int flags); 744 745 struct sock * (*accept) (struct sock *sk, int flags, int *err); 746 747 int (*ioctl)(struct sock *sk, int cmd, 748 unsigned long arg); 749 int (*init)(struct sock *sk); 750 void (*destroy)(struct sock *sk); 751 void (*shutdown)(struct sock *sk, int how); 752 int (*setsockopt)(struct sock *sk, int level, 753 int optname, char __user *optval, 754 unsigned int optlen); 755 int (*getsockopt)(struct sock *sk, int level, 756 int optname, char __user *optval, 757 int __user *option); 758 #ifdef CONFIG_COMPAT 759 int (*compat_setsockopt)(struct sock *sk, 760 int level, 761 int optname, char __user *optval, 762 unsigned int optlen); 763 int (*compat_getsockopt)(struct sock *sk, 764 int level, 765 int optname, char __user *optval, 766 int __user *option); 767 int (*compat_ioctl)(struct sock *sk, 768 unsigned int cmd, unsigned long arg); 769 #endif 770 int (*sendmsg)(struct kiocb *iocb, struct sock *sk, 771 struct msghdr *msg, size_t len); 772 int (*recvmsg)(struct kiocb *iocb, struct sock *sk, 773 struct msghdr *msg, 774 size_t len, int noblock, int flags, 775 int *addr_len); 776 int (*sendpage)(struct sock *sk, struct page *page, 777 int offset, size_t size, int flags); 778 int (*bind)(struct sock *sk, 779 struct sockaddr *uaddr, int addr_len); 780 781 int (*backlog_rcv) (struct sock *sk, 782 struct sk_buff *skb); 783 784 /* Keeping track of sk's, looking them up, and port selection methods. */ 785 void (*hash)(struct sock *sk); 786 void (*unhash)(struct sock *sk); 787 void (*rehash)(struct sock *sk); 788 int (*get_port)(struct sock *sk, unsigned short snum); 789 void (*clear_sk)(struct sock *sk, int size); 790 791 /* Keeping track of sockets in use */ 792 #ifdef CONFIG_PROC_FS 793 unsigned int inuse_idx; 794 #endif 795 796 /* Memory pressure */ 797 void (*enter_memory_pressure)(struct sock *sk); 798 atomic_long_t *memory_allocated; /* Current allocated memory. */ 799 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 800 /* 801 * Pressure flag: try to collapse. 802 * Technical note: it is used by multiple contexts non atomically. 803 * All the __sk_mem_schedule() is of this nature: accounting 804 * is strict, actions are advisory and have some latency. 805 */ 806 int *memory_pressure; 807 long *sysctl_mem; 808 int *sysctl_wmem; 809 int *sysctl_rmem; 810 int max_header; 811 bool no_autobind; 812 813 struct kmem_cache *slab; 814 unsigned int obj_size; 815 int slab_flags; 816 817 struct percpu_counter *orphan_count; 818 819 struct request_sock_ops *rsk_prot; 820 struct timewait_sock_ops *twsk_prot; 821 822 union { 823 struct inet_hashinfo *hashinfo; 824 struct udp_table *udp_table; 825 struct raw_hashinfo *raw_hash; 826 } h; 827 828 struct module *owner; 829 830 char name[32]; 831 832 struct list_head node; 833 #ifdef SOCK_REFCNT_DEBUG 834 atomic_t socks; 835 #endif 836 }; 837 838 extern int proto_register(struct proto *prot, int alloc_slab); 839 extern void proto_unregister(struct proto *prot); 840 841 #ifdef SOCK_REFCNT_DEBUG 842 static inline void sk_refcnt_debug_inc(struct sock *sk) 843 { 844 atomic_inc(&sk->sk_prot->socks); 845 } 846 847 static inline void sk_refcnt_debug_dec(struct sock *sk) 848 { 849 atomic_dec(&sk->sk_prot->socks); 850 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 851 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 852 } 853 854 static inline void sk_refcnt_debug_release(const struct sock *sk) 855 { 856 if (atomic_read(&sk->sk_refcnt) != 1) 857 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 858 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 859 } 860 #else /* SOCK_REFCNT_DEBUG */ 861 #define sk_refcnt_debug_inc(sk) do { } while (0) 862 #define sk_refcnt_debug_dec(sk) do { } while (0) 863 #define sk_refcnt_debug_release(sk) do { } while (0) 864 #endif /* SOCK_REFCNT_DEBUG */ 865 866 867 #ifdef CONFIG_PROC_FS 868 /* Called with local bh disabled */ 869 extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 870 extern int sock_prot_inuse_get(struct net *net, struct proto *proto); 871 #else 872 static void inline sock_prot_inuse_add(struct net *net, struct proto *prot, 873 int inc) 874 { 875 } 876 #endif 877 878 879 /* With per-bucket locks this operation is not-atomic, so that 880 * this version is not worse. 881 */ 882 static inline void __sk_prot_rehash(struct sock *sk) 883 { 884 sk->sk_prot->unhash(sk); 885 sk->sk_prot->hash(sk); 886 } 887 888 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 889 890 /* About 10 seconds */ 891 #define SOCK_DESTROY_TIME (10*HZ) 892 893 /* Sockets 0-1023 can't be bound to unless you are superuser */ 894 #define PROT_SOCK 1024 895 896 #define SHUTDOWN_MASK 3 897 #define RCV_SHUTDOWN 1 898 #define SEND_SHUTDOWN 2 899 900 #define SOCK_SNDBUF_LOCK 1 901 #define SOCK_RCVBUF_LOCK 2 902 #define SOCK_BINDADDR_LOCK 4 903 #define SOCK_BINDPORT_LOCK 8 904 905 /* sock_iocb: used to kick off async processing of socket ios */ 906 struct sock_iocb { 907 struct list_head list; 908 909 int flags; 910 int size; 911 struct socket *sock; 912 struct sock *sk; 913 struct scm_cookie *scm; 914 struct msghdr *msg, async_msg; 915 struct kiocb *kiocb; 916 }; 917 918 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb) 919 { 920 return (struct sock_iocb *)iocb->private; 921 } 922 923 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si) 924 { 925 return si->kiocb; 926 } 927 928 struct socket_alloc { 929 struct socket socket; 930 struct inode vfs_inode; 931 }; 932 933 static inline struct socket *SOCKET_I(struct inode *inode) 934 { 935 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 936 } 937 938 static inline struct inode *SOCK_INODE(struct socket *socket) 939 { 940 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 941 } 942 943 /* 944 * Functions for memory accounting 945 */ 946 extern int __sk_mem_schedule(struct sock *sk, int size, int kind); 947 extern void __sk_mem_reclaim(struct sock *sk); 948 949 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 950 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 951 #define SK_MEM_SEND 0 952 #define SK_MEM_RECV 1 953 954 static inline int sk_mem_pages(int amt) 955 { 956 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 957 } 958 959 static inline int sk_has_account(struct sock *sk) 960 { 961 /* return true if protocol supports memory accounting */ 962 return !!sk->sk_prot->memory_allocated; 963 } 964 965 static inline int sk_wmem_schedule(struct sock *sk, int size) 966 { 967 if (!sk_has_account(sk)) 968 return 1; 969 return size <= sk->sk_forward_alloc || 970 __sk_mem_schedule(sk, size, SK_MEM_SEND); 971 } 972 973 static inline int sk_rmem_schedule(struct sock *sk, int size) 974 { 975 if (!sk_has_account(sk)) 976 return 1; 977 return size <= sk->sk_forward_alloc || 978 __sk_mem_schedule(sk, size, SK_MEM_RECV); 979 } 980 981 static inline void sk_mem_reclaim(struct sock *sk) 982 { 983 if (!sk_has_account(sk)) 984 return; 985 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 986 __sk_mem_reclaim(sk); 987 } 988 989 static inline void sk_mem_reclaim_partial(struct sock *sk) 990 { 991 if (!sk_has_account(sk)) 992 return; 993 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 994 __sk_mem_reclaim(sk); 995 } 996 997 static inline void sk_mem_charge(struct sock *sk, int size) 998 { 999 if (!sk_has_account(sk)) 1000 return; 1001 sk->sk_forward_alloc -= size; 1002 } 1003 1004 static inline void sk_mem_uncharge(struct sock *sk, int size) 1005 { 1006 if (!sk_has_account(sk)) 1007 return; 1008 sk->sk_forward_alloc += size; 1009 } 1010 1011 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1012 { 1013 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1014 sk->sk_wmem_queued -= skb->truesize; 1015 sk_mem_uncharge(sk, skb->truesize); 1016 __kfree_skb(skb); 1017 } 1018 1019 /* Used by processes to "lock" a socket state, so that 1020 * interrupts and bottom half handlers won't change it 1021 * from under us. It essentially blocks any incoming 1022 * packets, so that we won't get any new data or any 1023 * packets that change the state of the socket. 1024 * 1025 * While locked, BH processing will add new packets to 1026 * the backlog queue. This queue is processed by the 1027 * owner of the socket lock right before it is released. 1028 * 1029 * Since ~2.3.5 it is also exclusive sleep lock serializing 1030 * accesses from user process context. 1031 */ 1032 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned) 1033 1034 /* 1035 * Macro so as to not evaluate some arguments when 1036 * lockdep is not enabled. 1037 * 1038 * Mark both the sk_lock and the sk_lock.slock as a 1039 * per-address-family lock class. 1040 */ 1041 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1042 do { \ 1043 sk->sk_lock.owned = 0; \ 1044 init_waitqueue_head(&sk->sk_lock.wq); \ 1045 spin_lock_init(&(sk)->sk_lock.slock); \ 1046 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1047 sizeof((sk)->sk_lock)); \ 1048 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1049 (skey), (sname)); \ 1050 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1051 } while (0) 1052 1053 extern void lock_sock_nested(struct sock *sk, int subclass); 1054 1055 static inline void lock_sock(struct sock *sk) 1056 { 1057 lock_sock_nested(sk, 0); 1058 } 1059 1060 extern void release_sock(struct sock *sk); 1061 1062 /* BH context may only use the following locking interface. */ 1063 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1064 #define bh_lock_sock_nested(__sk) \ 1065 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1066 SINGLE_DEPTH_NESTING) 1067 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1068 1069 extern bool lock_sock_fast(struct sock *sk); 1070 /** 1071 * unlock_sock_fast - complement of lock_sock_fast 1072 * @sk: socket 1073 * @slow: slow mode 1074 * 1075 * fast unlock socket for user context. 1076 * If slow mode is on, we call regular release_sock() 1077 */ 1078 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1079 { 1080 if (slow) 1081 release_sock(sk); 1082 else 1083 spin_unlock_bh(&sk->sk_lock.slock); 1084 } 1085 1086 1087 extern struct sock *sk_alloc(struct net *net, int family, 1088 gfp_t priority, 1089 struct proto *prot); 1090 extern void sk_free(struct sock *sk); 1091 extern void sk_release_kernel(struct sock *sk); 1092 extern struct sock *sk_clone(const struct sock *sk, 1093 const gfp_t priority); 1094 1095 extern struct sk_buff *sock_wmalloc(struct sock *sk, 1096 unsigned long size, int force, 1097 gfp_t priority); 1098 extern struct sk_buff *sock_rmalloc(struct sock *sk, 1099 unsigned long size, int force, 1100 gfp_t priority); 1101 extern void sock_wfree(struct sk_buff *skb); 1102 extern void sock_rfree(struct sk_buff *skb); 1103 1104 extern int sock_setsockopt(struct socket *sock, int level, 1105 int op, char __user *optval, 1106 unsigned int optlen); 1107 1108 extern int sock_getsockopt(struct socket *sock, int level, 1109 int op, char __user *optval, 1110 int __user *optlen); 1111 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk, 1112 unsigned long size, 1113 int noblock, 1114 int *errcode); 1115 extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk, 1116 unsigned long header_len, 1117 unsigned long data_len, 1118 int noblock, 1119 int *errcode); 1120 extern void *sock_kmalloc(struct sock *sk, int size, 1121 gfp_t priority); 1122 extern void sock_kfree_s(struct sock *sk, void *mem, int size); 1123 extern void sk_send_sigurg(struct sock *sk); 1124 1125 #ifdef CONFIG_CGROUPS 1126 extern void sock_update_classid(struct sock *sk); 1127 #else 1128 static inline void sock_update_classid(struct sock *sk) 1129 { 1130 } 1131 #endif 1132 1133 /* 1134 * Functions to fill in entries in struct proto_ops when a protocol 1135 * does not implement a particular function. 1136 */ 1137 extern int sock_no_bind(struct socket *, 1138 struct sockaddr *, int); 1139 extern int sock_no_connect(struct socket *, 1140 struct sockaddr *, int, int); 1141 extern int sock_no_socketpair(struct socket *, 1142 struct socket *); 1143 extern int sock_no_accept(struct socket *, 1144 struct socket *, int); 1145 extern int sock_no_getname(struct socket *, 1146 struct sockaddr *, int *, int); 1147 extern unsigned int sock_no_poll(struct file *, struct socket *, 1148 struct poll_table_struct *); 1149 extern int sock_no_ioctl(struct socket *, unsigned int, 1150 unsigned long); 1151 extern int sock_no_listen(struct socket *, int); 1152 extern int sock_no_shutdown(struct socket *, int); 1153 extern int sock_no_getsockopt(struct socket *, int , int, 1154 char __user *, int __user *); 1155 extern int sock_no_setsockopt(struct socket *, int, int, 1156 char __user *, unsigned int); 1157 extern int sock_no_sendmsg(struct kiocb *, struct socket *, 1158 struct msghdr *, size_t); 1159 extern int sock_no_recvmsg(struct kiocb *, struct socket *, 1160 struct msghdr *, size_t, int); 1161 extern int sock_no_mmap(struct file *file, 1162 struct socket *sock, 1163 struct vm_area_struct *vma); 1164 extern ssize_t sock_no_sendpage(struct socket *sock, 1165 struct page *page, 1166 int offset, size_t size, 1167 int flags); 1168 1169 /* 1170 * Functions to fill in entries in struct proto_ops when a protocol 1171 * uses the inet style. 1172 */ 1173 extern int sock_common_getsockopt(struct socket *sock, int level, int optname, 1174 char __user *optval, int __user *optlen); 1175 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock, 1176 struct msghdr *msg, size_t size, int flags); 1177 extern int sock_common_setsockopt(struct socket *sock, int level, int optname, 1178 char __user *optval, unsigned int optlen); 1179 extern int compat_sock_common_getsockopt(struct socket *sock, int level, 1180 int optname, char __user *optval, int __user *optlen); 1181 extern int compat_sock_common_setsockopt(struct socket *sock, int level, 1182 int optname, char __user *optval, unsigned int optlen); 1183 1184 extern void sk_common_release(struct sock *sk); 1185 1186 /* 1187 * Default socket callbacks and setup code 1188 */ 1189 1190 /* Initialise core socket variables */ 1191 extern void sock_init_data(struct socket *sock, struct sock *sk); 1192 1193 extern void sk_filter_release_rcu(struct rcu_head *rcu); 1194 1195 /** 1196 * sk_filter_release - release a socket filter 1197 * @fp: filter to remove 1198 * 1199 * Remove a filter from a socket and release its resources. 1200 */ 1201 1202 static inline void sk_filter_release(struct sk_filter *fp) 1203 { 1204 if (atomic_dec_and_test(&fp->refcnt)) 1205 call_rcu(&fp->rcu, sk_filter_release_rcu); 1206 } 1207 1208 static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) 1209 { 1210 unsigned int size = sk_filter_len(fp); 1211 1212 atomic_sub(size, &sk->sk_omem_alloc); 1213 sk_filter_release(fp); 1214 } 1215 1216 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp) 1217 { 1218 atomic_inc(&fp->refcnt); 1219 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc); 1220 } 1221 1222 /* 1223 * Socket reference counting postulates. 1224 * 1225 * * Each user of socket SHOULD hold a reference count. 1226 * * Each access point to socket (an hash table bucket, reference from a list, 1227 * running timer, skb in flight MUST hold a reference count. 1228 * * When reference count hits 0, it means it will never increase back. 1229 * * When reference count hits 0, it means that no references from 1230 * outside exist to this socket and current process on current CPU 1231 * is last user and may/should destroy this socket. 1232 * * sk_free is called from any context: process, BH, IRQ. When 1233 * it is called, socket has no references from outside -> sk_free 1234 * may release descendant resources allocated by the socket, but 1235 * to the time when it is called, socket is NOT referenced by any 1236 * hash tables, lists etc. 1237 * * Packets, delivered from outside (from network or from another process) 1238 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1239 * when they sit in queue. Otherwise, packets will leak to hole, when 1240 * socket is looked up by one cpu and unhasing is made by another CPU. 1241 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1242 * (leak to backlog). Packet socket does all the processing inside 1243 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1244 * use separate SMP lock, so that they are prone too. 1245 */ 1246 1247 /* Ungrab socket and destroy it, if it was the last reference. */ 1248 static inline void sock_put(struct sock *sk) 1249 { 1250 if (atomic_dec_and_test(&sk->sk_refcnt)) 1251 sk_free(sk); 1252 } 1253 1254 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1255 const int nested); 1256 1257 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1258 { 1259 sk->sk_tx_queue_mapping = tx_queue; 1260 } 1261 1262 static inline void sk_tx_queue_clear(struct sock *sk) 1263 { 1264 sk->sk_tx_queue_mapping = -1; 1265 } 1266 1267 static inline int sk_tx_queue_get(const struct sock *sk) 1268 { 1269 return sk ? sk->sk_tx_queue_mapping : -1; 1270 } 1271 1272 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1273 { 1274 sk_tx_queue_clear(sk); 1275 sk->sk_socket = sock; 1276 } 1277 1278 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1279 { 1280 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1281 return &rcu_dereference_raw(sk->sk_wq)->wait; 1282 } 1283 /* Detach socket from process context. 1284 * Announce socket dead, detach it from wait queue and inode. 1285 * Note that parent inode held reference count on this struct sock, 1286 * we do not release it in this function, because protocol 1287 * probably wants some additional cleanups or even continuing 1288 * to work with this socket (TCP). 1289 */ 1290 static inline void sock_orphan(struct sock *sk) 1291 { 1292 write_lock_bh(&sk->sk_callback_lock); 1293 sock_set_flag(sk, SOCK_DEAD); 1294 sk_set_socket(sk, NULL); 1295 sk->sk_wq = NULL; 1296 write_unlock_bh(&sk->sk_callback_lock); 1297 } 1298 1299 static inline void sock_graft(struct sock *sk, struct socket *parent) 1300 { 1301 write_lock_bh(&sk->sk_callback_lock); 1302 sk->sk_wq = parent->wq; 1303 parent->sk = sk; 1304 sk_set_socket(sk, parent); 1305 security_sock_graft(sk, parent); 1306 write_unlock_bh(&sk->sk_callback_lock); 1307 } 1308 1309 extern int sock_i_uid(struct sock *sk); 1310 extern unsigned long sock_i_ino(struct sock *sk); 1311 1312 static inline struct dst_entry * 1313 __sk_dst_get(struct sock *sk) 1314 { 1315 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) || 1316 lockdep_is_held(&sk->sk_lock.slock)); 1317 } 1318 1319 static inline struct dst_entry * 1320 sk_dst_get(struct sock *sk) 1321 { 1322 struct dst_entry *dst; 1323 1324 rcu_read_lock(); 1325 dst = rcu_dereference(sk->sk_dst_cache); 1326 if (dst) 1327 dst_hold(dst); 1328 rcu_read_unlock(); 1329 return dst; 1330 } 1331 1332 extern void sk_reset_txq(struct sock *sk); 1333 1334 static inline void dst_negative_advice(struct sock *sk) 1335 { 1336 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1337 1338 if (dst && dst->ops->negative_advice) { 1339 ndst = dst->ops->negative_advice(dst); 1340 1341 if (ndst != dst) { 1342 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1343 sk_reset_txq(sk); 1344 } 1345 } 1346 } 1347 1348 static inline void 1349 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1350 { 1351 struct dst_entry *old_dst; 1352 1353 sk_tx_queue_clear(sk); 1354 /* 1355 * This can be called while sk is owned by the caller only, 1356 * with no state that can be checked in a rcu_dereference_check() cond 1357 */ 1358 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1359 rcu_assign_pointer(sk->sk_dst_cache, dst); 1360 dst_release(old_dst); 1361 } 1362 1363 static inline void 1364 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1365 { 1366 spin_lock(&sk->sk_dst_lock); 1367 __sk_dst_set(sk, dst); 1368 spin_unlock(&sk->sk_dst_lock); 1369 } 1370 1371 static inline void 1372 __sk_dst_reset(struct sock *sk) 1373 { 1374 __sk_dst_set(sk, NULL); 1375 } 1376 1377 static inline void 1378 sk_dst_reset(struct sock *sk) 1379 { 1380 spin_lock(&sk->sk_dst_lock); 1381 __sk_dst_reset(sk); 1382 spin_unlock(&sk->sk_dst_lock); 1383 } 1384 1385 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1386 1387 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1388 1389 static inline int sk_can_gso(const struct sock *sk) 1390 { 1391 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1392 } 1393 1394 extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1395 1396 static inline void sk_nocaps_add(struct sock *sk, int flags) 1397 { 1398 sk->sk_route_nocaps |= flags; 1399 sk->sk_route_caps &= ~flags; 1400 } 1401 1402 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1403 char __user *from, char *to, 1404 int copy, int offset) 1405 { 1406 if (skb->ip_summed == CHECKSUM_NONE) { 1407 int err = 0; 1408 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err); 1409 if (err) 1410 return err; 1411 skb->csum = csum_block_add(skb->csum, csum, offset); 1412 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1413 if (!access_ok(VERIFY_READ, from, copy) || 1414 __copy_from_user_nocache(to, from, copy)) 1415 return -EFAULT; 1416 } else if (copy_from_user(to, from, copy)) 1417 return -EFAULT; 1418 1419 return 0; 1420 } 1421 1422 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1423 char __user *from, int copy) 1424 { 1425 int err, offset = skb->len; 1426 1427 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1428 copy, offset); 1429 if (err) 1430 __skb_trim(skb, offset); 1431 1432 return err; 1433 } 1434 1435 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from, 1436 struct sk_buff *skb, 1437 struct page *page, 1438 int off, int copy) 1439 { 1440 int err; 1441 1442 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1443 copy, skb->len); 1444 if (err) 1445 return err; 1446 1447 skb->len += copy; 1448 skb->data_len += copy; 1449 skb->truesize += copy; 1450 sk->sk_wmem_queued += copy; 1451 sk_mem_charge(sk, copy); 1452 return 0; 1453 } 1454 1455 static inline int skb_copy_to_page(struct sock *sk, char __user *from, 1456 struct sk_buff *skb, struct page *page, 1457 int off, int copy) 1458 { 1459 if (skb->ip_summed == CHECKSUM_NONE) { 1460 int err = 0; 1461 __wsum csum = csum_and_copy_from_user(from, 1462 page_address(page) + off, 1463 copy, 0, &err); 1464 if (err) 1465 return err; 1466 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1467 } else if (copy_from_user(page_address(page) + off, from, copy)) 1468 return -EFAULT; 1469 1470 skb->len += copy; 1471 skb->data_len += copy; 1472 skb->truesize += copy; 1473 sk->sk_wmem_queued += copy; 1474 sk_mem_charge(sk, copy); 1475 return 0; 1476 } 1477 1478 /** 1479 * sk_wmem_alloc_get - returns write allocations 1480 * @sk: socket 1481 * 1482 * Returns sk_wmem_alloc minus initial offset of one 1483 */ 1484 static inline int sk_wmem_alloc_get(const struct sock *sk) 1485 { 1486 return atomic_read(&sk->sk_wmem_alloc) - 1; 1487 } 1488 1489 /** 1490 * sk_rmem_alloc_get - returns read allocations 1491 * @sk: socket 1492 * 1493 * Returns sk_rmem_alloc 1494 */ 1495 static inline int sk_rmem_alloc_get(const struct sock *sk) 1496 { 1497 return atomic_read(&sk->sk_rmem_alloc); 1498 } 1499 1500 /** 1501 * sk_has_allocations - check if allocations are outstanding 1502 * @sk: socket 1503 * 1504 * Returns true if socket has write or read allocations 1505 */ 1506 static inline int sk_has_allocations(const struct sock *sk) 1507 { 1508 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1509 } 1510 1511 /** 1512 * wq_has_sleeper - check if there are any waiting processes 1513 * @wq: struct socket_wq 1514 * 1515 * Returns true if socket_wq has waiting processes 1516 * 1517 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory 1518 * barrier call. They were added due to the race found within the tcp code. 1519 * 1520 * Consider following tcp code paths: 1521 * 1522 * CPU1 CPU2 1523 * 1524 * sys_select receive packet 1525 * ... ... 1526 * __add_wait_queue update tp->rcv_nxt 1527 * ... ... 1528 * tp->rcv_nxt check sock_def_readable 1529 * ... { 1530 * schedule rcu_read_lock(); 1531 * wq = rcu_dereference(sk->sk_wq); 1532 * if (wq && waitqueue_active(&wq->wait)) 1533 * wake_up_interruptible(&wq->wait) 1534 * ... 1535 * } 1536 * 1537 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1538 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1539 * could then endup calling schedule and sleep forever if there are no more 1540 * data on the socket. 1541 * 1542 */ 1543 static inline bool wq_has_sleeper(struct socket_wq *wq) 1544 { 1545 1546 /* 1547 * We need to be sure we are in sync with the 1548 * add_wait_queue modifications to the wait queue. 1549 * 1550 * This memory barrier is paired in the sock_poll_wait. 1551 */ 1552 smp_mb(); 1553 return wq && waitqueue_active(&wq->wait); 1554 } 1555 1556 /** 1557 * sock_poll_wait - place memory barrier behind the poll_wait call. 1558 * @filp: file 1559 * @wait_address: socket wait queue 1560 * @p: poll_table 1561 * 1562 * See the comments in the wq_has_sleeper function. 1563 */ 1564 static inline void sock_poll_wait(struct file *filp, 1565 wait_queue_head_t *wait_address, poll_table *p) 1566 { 1567 if (p && wait_address) { 1568 poll_wait(filp, wait_address, p); 1569 /* 1570 * We need to be sure we are in sync with the 1571 * socket flags modification. 1572 * 1573 * This memory barrier is paired in the wq_has_sleeper. 1574 */ 1575 smp_mb(); 1576 } 1577 } 1578 1579 /* 1580 * Queue a received datagram if it will fit. Stream and sequenced 1581 * protocols can't normally use this as they need to fit buffers in 1582 * and play with them. 1583 * 1584 * Inlined as it's very short and called for pretty much every 1585 * packet ever received. 1586 */ 1587 1588 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1589 { 1590 skb_orphan(skb); 1591 skb->sk = sk; 1592 skb->destructor = sock_wfree; 1593 /* 1594 * We used to take a refcount on sk, but following operation 1595 * is enough to guarantee sk_free() wont free this sock until 1596 * all in-flight packets are completed 1597 */ 1598 atomic_add(skb->truesize, &sk->sk_wmem_alloc); 1599 } 1600 1601 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1602 { 1603 skb_orphan(skb); 1604 skb->sk = sk; 1605 skb->destructor = sock_rfree; 1606 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1607 sk_mem_charge(sk, skb->truesize); 1608 } 1609 1610 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer, 1611 unsigned long expires); 1612 1613 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer); 1614 1615 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1616 1617 extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 1618 1619 /* 1620 * Recover an error report and clear atomically 1621 */ 1622 1623 static inline int sock_error(struct sock *sk) 1624 { 1625 int err; 1626 if (likely(!sk->sk_err)) 1627 return 0; 1628 err = xchg(&sk->sk_err, 0); 1629 return -err; 1630 } 1631 1632 static inline unsigned long sock_wspace(struct sock *sk) 1633 { 1634 int amt = 0; 1635 1636 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 1637 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 1638 if (amt < 0) 1639 amt = 0; 1640 } 1641 return amt; 1642 } 1643 1644 static inline void sk_wake_async(struct sock *sk, int how, int band) 1645 { 1646 if (sock_flag(sk, SOCK_FASYNC)) 1647 sock_wake_async(sk->sk_socket, how, band); 1648 } 1649 1650 #define SOCK_MIN_SNDBUF 2048 1651 /* 1652 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need 1653 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak 1654 */ 1655 #define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff)) 1656 1657 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 1658 { 1659 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 1660 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 1661 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF); 1662 } 1663 } 1664 1665 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp); 1666 1667 static inline struct page *sk_stream_alloc_page(struct sock *sk) 1668 { 1669 struct page *page = NULL; 1670 1671 page = alloc_pages(sk->sk_allocation, 0); 1672 if (!page) { 1673 sk->sk_prot->enter_memory_pressure(sk); 1674 sk_stream_moderate_sndbuf(sk); 1675 } 1676 return page; 1677 } 1678 1679 /* 1680 * Default write policy as shown to user space via poll/select/SIGIO 1681 */ 1682 static inline int sock_writeable(const struct sock *sk) 1683 { 1684 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 1685 } 1686 1687 static inline gfp_t gfp_any(void) 1688 { 1689 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 1690 } 1691 1692 static inline long sock_rcvtimeo(const struct sock *sk, int noblock) 1693 { 1694 return noblock ? 0 : sk->sk_rcvtimeo; 1695 } 1696 1697 static inline long sock_sndtimeo(const struct sock *sk, int noblock) 1698 { 1699 return noblock ? 0 : sk->sk_sndtimeo; 1700 } 1701 1702 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 1703 { 1704 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 1705 } 1706 1707 /* Alas, with timeout socket operations are not restartable. 1708 * Compare this to poll(). 1709 */ 1710 static inline int sock_intr_errno(long timeo) 1711 { 1712 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 1713 } 1714 1715 extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 1716 struct sk_buff *skb); 1717 1718 static __inline__ void 1719 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 1720 { 1721 ktime_t kt = skb->tstamp; 1722 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 1723 1724 /* 1725 * generate control messages if 1726 * - receive time stamping in software requested (SOCK_RCVTSTAMP 1727 * or SOCK_TIMESTAMPING_RX_SOFTWARE) 1728 * - software time stamp available and wanted 1729 * (SOCK_TIMESTAMPING_SOFTWARE) 1730 * - hardware time stamps available and wanted 1731 * (SOCK_TIMESTAMPING_SYS_HARDWARE or 1732 * SOCK_TIMESTAMPING_RAW_HARDWARE) 1733 */ 1734 if (sock_flag(sk, SOCK_RCVTSTAMP) || 1735 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) || 1736 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) || 1737 (hwtstamps->hwtstamp.tv64 && 1738 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) || 1739 (hwtstamps->syststamp.tv64 && 1740 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))) 1741 __sock_recv_timestamp(msg, sk, skb); 1742 else 1743 sk->sk_stamp = kt; 1744 } 1745 1746 extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 1747 struct sk_buff *skb); 1748 1749 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 1750 struct sk_buff *skb) 1751 { 1752 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 1753 (1UL << SOCK_RCVTSTAMP) | \ 1754 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \ 1755 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \ 1756 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \ 1757 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE)) 1758 1759 if (sk->sk_flags & FLAGS_TS_OR_DROPS) 1760 __sock_recv_ts_and_drops(msg, sk, skb); 1761 else 1762 sk->sk_stamp = skb->tstamp; 1763 } 1764 1765 /** 1766 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 1767 * @sk: socket sending this packet 1768 * @tx_flags: filled with instructions for time stamping 1769 * 1770 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if 1771 * parameters are invalid. 1772 */ 1773 extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags); 1774 1775 /** 1776 * sk_eat_skb - Release a skb if it is no longer needed 1777 * @sk: socket to eat this skb from 1778 * @skb: socket buffer to eat 1779 * @copied_early: flag indicating whether DMA operations copied this data early 1780 * 1781 * This routine must be called with interrupts disabled or with the socket 1782 * locked so that the sk_buff queue operation is ok. 1783 */ 1784 #ifdef CONFIG_NET_DMA 1785 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) 1786 { 1787 __skb_unlink(skb, &sk->sk_receive_queue); 1788 if (!copied_early) 1789 __kfree_skb(skb); 1790 else 1791 __skb_queue_tail(&sk->sk_async_wait_queue, skb); 1792 } 1793 #else 1794 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) 1795 { 1796 __skb_unlink(skb, &sk->sk_receive_queue); 1797 __kfree_skb(skb); 1798 } 1799 #endif 1800 1801 static inline 1802 struct net *sock_net(const struct sock *sk) 1803 { 1804 return read_pnet(&sk->sk_net); 1805 } 1806 1807 static inline 1808 void sock_net_set(struct sock *sk, struct net *net) 1809 { 1810 write_pnet(&sk->sk_net, net); 1811 } 1812 1813 /* 1814 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace. 1815 * They should not hold a reference to a namespace in order to allow 1816 * to stop it. 1817 * Sockets after sk_change_net should be released using sk_release_kernel 1818 */ 1819 static inline void sk_change_net(struct sock *sk, struct net *net) 1820 { 1821 put_net(sock_net(sk)); 1822 sock_net_set(sk, hold_net(net)); 1823 } 1824 1825 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 1826 { 1827 if (unlikely(skb->sk)) { 1828 struct sock *sk = skb->sk; 1829 1830 skb->destructor = NULL; 1831 skb->sk = NULL; 1832 return sk; 1833 } 1834 return NULL; 1835 } 1836 1837 extern void sock_enable_timestamp(struct sock *sk, int flag); 1838 extern int sock_get_timestamp(struct sock *, struct timeval __user *); 1839 extern int sock_get_timestampns(struct sock *, struct timespec __user *); 1840 1841 /* 1842 * Enable debug/info messages 1843 */ 1844 extern int net_msg_warn; 1845 #define NETDEBUG(fmt, args...) \ 1846 do { if (net_msg_warn) printk(fmt,##args); } while (0) 1847 1848 #define LIMIT_NETDEBUG(fmt, args...) \ 1849 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0) 1850 1851 extern __u32 sysctl_wmem_max; 1852 extern __u32 sysctl_rmem_max; 1853 1854 extern void sk_init(void); 1855 1856 extern int sysctl_optmem_max; 1857 1858 extern __u32 sysctl_wmem_default; 1859 extern __u32 sysctl_rmem_default; 1860 1861 #endif /* _SOCK_H */ 1862