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/bitops.h> 50 #include <linux/lockdep.h> 51 #include <linux/netdevice.h> 52 #include <linux/skbuff.h> /* struct sk_buff */ 53 #include <linux/mm.h> 54 #include <linux/security.h> 55 #include <linux/slab.h> 56 #include <linux/uaccess.h> 57 #include <linux/memcontrol.h> 58 #include <linux/res_counter.h> 59 #include <linux/static_key.h> 60 #include <linux/aio.h> 61 #include <linux/sched.h> 62 63 #include <linux/filter.h> 64 #include <linux/rculist_nulls.h> 65 #include <linux/poll.h> 66 67 #include <linux/atomic.h> 68 #include <net/dst.h> 69 #include <net/checksum.h> 70 71 struct cgroup; 72 struct cgroup_subsys; 73 #ifdef CONFIG_NET 74 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss); 75 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg); 76 #else 77 static inline 78 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss) 79 { 80 return 0; 81 } 82 static inline 83 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg) 84 { 85 } 86 #endif 87 /* 88 * This structure really needs to be cleaned up. 89 * Most of it is for TCP, and not used by any of 90 * the other protocols. 91 */ 92 93 /* Define this to get the SOCK_DBG debugging facility. */ 94 #define SOCK_DEBUGGING 95 #ifdef SOCK_DEBUGGING 96 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 97 printk(KERN_DEBUG msg); } while (0) 98 #else 99 /* Validate arguments and do nothing */ 100 static inline __printf(2, 3) 101 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 102 { 103 } 104 #endif 105 106 /* This is the per-socket lock. The spinlock provides a synchronization 107 * between user contexts and software interrupt processing, whereas the 108 * mini-semaphore synchronizes multiple users amongst themselves. 109 */ 110 typedef struct { 111 spinlock_t slock; 112 int owned; 113 wait_queue_head_t wq; 114 /* 115 * We express the mutex-alike socket_lock semantics 116 * to the lock validator by explicitly managing 117 * the slock as a lock variant (in addition to 118 * the slock itself): 119 */ 120 #ifdef CONFIG_DEBUG_LOCK_ALLOC 121 struct lockdep_map dep_map; 122 #endif 123 } socket_lock_t; 124 125 struct sock; 126 struct proto; 127 struct net; 128 129 typedef __u32 __bitwise __portpair; 130 typedef __u64 __bitwise __addrpair; 131 132 /** 133 * struct sock_common - minimal network layer representation of sockets 134 * @skc_daddr: Foreign IPv4 addr 135 * @skc_rcv_saddr: Bound local IPv4 addr 136 * @skc_hash: hash value used with various protocol lookup tables 137 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 138 * @skc_dport: placeholder for inet_dport/tw_dport 139 * @skc_num: placeholder for inet_num/tw_num 140 * @skc_family: network address family 141 * @skc_state: Connection state 142 * @skc_reuse: %SO_REUSEADDR setting 143 * @skc_reuseport: %SO_REUSEPORT setting 144 * @skc_bound_dev_if: bound device index if != 0 145 * @skc_bind_node: bind hash linkage for various protocol lookup tables 146 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 147 * @skc_prot: protocol handlers inside a network family 148 * @skc_net: reference to the network namespace of this socket 149 * @skc_node: main hash linkage for various protocol lookup tables 150 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 151 * @skc_tx_queue_mapping: tx queue number for this connection 152 * @skc_refcnt: reference count 153 * 154 * This is the minimal network layer representation of sockets, the header 155 * for struct sock and struct inet_timewait_sock. 156 */ 157 struct sock_common { 158 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 159 * address on 64bit arches : cf INET_MATCH() and INET_TW_MATCH() 160 */ 161 union { 162 __addrpair skc_addrpair; 163 struct { 164 __be32 skc_daddr; 165 __be32 skc_rcv_saddr; 166 }; 167 }; 168 union { 169 unsigned int skc_hash; 170 __u16 skc_u16hashes[2]; 171 }; 172 /* skc_dport && skc_num must be grouped as well */ 173 union { 174 __portpair skc_portpair; 175 struct { 176 __be16 skc_dport; 177 __u16 skc_num; 178 }; 179 }; 180 181 unsigned short skc_family; 182 volatile unsigned char skc_state; 183 unsigned char skc_reuse:4; 184 unsigned char skc_reuseport:4; 185 int skc_bound_dev_if; 186 union { 187 struct hlist_node skc_bind_node; 188 struct hlist_nulls_node skc_portaddr_node; 189 }; 190 struct proto *skc_prot; 191 #ifdef CONFIG_NET_NS 192 struct net *skc_net; 193 #endif 194 /* 195 * fields between dontcopy_begin/dontcopy_end 196 * are not copied in sock_copy() 197 */ 198 /* private: */ 199 int skc_dontcopy_begin[0]; 200 /* public: */ 201 union { 202 struct hlist_node skc_node; 203 struct hlist_nulls_node skc_nulls_node; 204 }; 205 int skc_tx_queue_mapping; 206 atomic_t skc_refcnt; 207 /* private: */ 208 int skc_dontcopy_end[0]; 209 /* public: */ 210 }; 211 212 struct cg_proto; 213 /** 214 * struct sock - network layer representation of sockets 215 * @__sk_common: shared layout with inet_timewait_sock 216 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 217 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 218 * @sk_lock: synchronizer 219 * @sk_rcvbuf: size of receive buffer in bytes 220 * @sk_wq: sock wait queue and async head 221 * @sk_rx_dst: receive input route used by early tcp demux 222 * @sk_dst_cache: destination cache 223 * @sk_dst_lock: destination cache lock 224 * @sk_policy: flow policy 225 * @sk_receive_queue: incoming packets 226 * @sk_wmem_alloc: transmit queue bytes committed 227 * @sk_write_queue: Packet sending queue 228 * @sk_async_wait_queue: DMA copied packets 229 * @sk_omem_alloc: "o" is "option" or "other" 230 * @sk_wmem_queued: persistent queue size 231 * @sk_forward_alloc: space allocated forward 232 * @sk_allocation: allocation mode 233 * @sk_sndbuf: size of send buffer in bytes 234 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 235 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 236 * @sk_no_check: %SO_NO_CHECK setting, whether or not checkup packets 237 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 238 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 239 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 240 * @sk_gso_max_size: Maximum GSO segment size to build 241 * @sk_gso_max_segs: Maximum number of GSO segments 242 * @sk_lingertime: %SO_LINGER l_linger setting 243 * @sk_backlog: always used with the per-socket spinlock held 244 * @sk_callback_lock: used with the callbacks in the end of this struct 245 * @sk_error_queue: rarely used 246 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 247 * IPV6_ADDRFORM for instance) 248 * @sk_err: last error 249 * @sk_err_soft: errors that don't cause failure but are the cause of a 250 * persistent failure not just 'timed out' 251 * @sk_drops: raw/udp drops counter 252 * @sk_ack_backlog: current listen backlog 253 * @sk_max_ack_backlog: listen backlog set in listen() 254 * @sk_priority: %SO_PRIORITY setting 255 * @sk_cgrp_prioidx: socket group's priority map index 256 * @sk_type: socket type (%SOCK_STREAM, etc) 257 * @sk_protocol: which protocol this socket belongs in this network family 258 * @sk_peer_pid: &struct pid for this socket's peer 259 * @sk_peer_cred: %SO_PEERCRED setting 260 * @sk_rcvlowat: %SO_RCVLOWAT setting 261 * @sk_rcvtimeo: %SO_RCVTIMEO setting 262 * @sk_sndtimeo: %SO_SNDTIMEO setting 263 * @sk_rxhash: flow hash received from netif layer 264 * @sk_filter: socket filtering instructions 265 * @sk_protinfo: private area, net family specific, when not using slab 266 * @sk_timer: sock cleanup timer 267 * @sk_stamp: time stamp of last packet received 268 * @sk_socket: Identd and reporting IO signals 269 * @sk_user_data: RPC layer private data 270 * @sk_frag: cached page frag 271 * @sk_peek_off: current peek_offset value 272 * @sk_send_head: front of stuff to transmit 273 * @sk_security: used by security modules 274 * @sk_mark: generic packet mark 275 * @sk_classid: this socket's cgroup classid 276 * @sk_cgrp: this socket's cgroup-specific proto data 277 * @sk_write_pending: a write to stream socket waits to start 278 * @sk_state_change: callback to indicate change in the state of the sock 279 * @sk_data_ready: callback to indicate there is data to be processed 280 * @sk_write_space: callback to indicate there is bf sending space available 281 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 282 * @sk_backlog_rcv: callback to process the backlog 283 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 284 */ 285 struct sock { 286 /* 287 * Now struct inet_timewait_sock also uses sock_common, so please just 288 * don't add nothing before this first member (__sk_common) --acme 289 */ 290 struct sock_common __sk_common; 291 #define sk_node __sk_common.skc_node 292 #define sk_nulls_node __sk_common.skc_nulls_node 293 #define sk_refcnt __sk_common.skc_refcnt 294 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 295 296 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 297 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 298 #define sk_hash __sk_common.skc_hash 299 #define sk_family __sk_common.skc_family 300 #define sk_state __sk_common.skc_state 301 #define sk_reuse __sk_common.skc_reuse 302 #define sk_reuseport __sk_common.skc_reuseport 303 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 304 #define sk_bind_node __sk_common.skc_bind_node 305 #define sk_prot __sk_common.skc_prot 306 #define sk_net __sk_common.skc_net 307 socket_lock_t sk_lock; 308 struct sk_buff_head sk_receive_queue; 309 /* 310 * The backlog queue is special, it is always used with 311 * the per-socket spinlock held and requires low latency 312 * access. Therefore we special case it's implementation. 313 * Note : rmem_alloc is in this structure to fill a hole 314 * on 64bit arches, not because its logically part of 315 * backlog. 316 */ 317 struct { 318 atomic_t rmem_alloc; 319 int len; 320 struct sk_buff *head; 321 struct sk_buff *tail; 322 } sk_backlog; 323 #define sk_rmem_alloc sk_backlog.rmem_alloc 324 int sk_forward_alloc; 325 #ifdef CONFIG_RPS 326 __u32 sk_rxhash; 327 #endif 328 atomic_t sk_drops; 329 int sk_rcvbuf; 330 331 struct sk_filter __rcu *sk_filter; 332 struct socket_wq __rcu *sk_wq; 333 334 #ifdef CONFIG_NET_DMA 335 struct sk_buff_head sk_async_wait_queue; 336 #endif 337 338 #ifdef CONFIG_XFRM 339 struct xfrm_policy *sk_policy[2]; 340 #endif 341 unsigned long sk_flags; 342 struct dst_entry *sk_rx_dst; 343 struct dst_entry __rcu *sk_dst_cache; 344 spinlock_t sk_dst_lock; 345 atomic_t sk_wmem_alloc; 346 atomic_t sk_omem_alloc; 347 int sk_sndbuf; 348 struct sk_buff_head sk_write_queue; 349 kmemcheck_bitfield_begin(flags); 350 unsigned int sk_shutdown : 2, 351 sk_no_check : 2, 352 sk_userlocks : 4, 353 sk_protocol : 8, 354 sk_type : 16; 355 kmemcheck_bitfield_end(flags); 356 int sk_wmem_queued; 357 gfp_t sk_allocation; 358 netdev_features_t sk_route_caps; 359 netdev_features_t sk_route_nocaps; 360 int sk_gso_type; 361 unsigned int sk_gso_max_size; 362 u16 sk_gso_max_segs; 363 int sk_rcvlowat; 364 unsigned long sk_lingertime; 365 struct sk_buff_head sk_error_queue; 366 struct proto *sk_prot_creator; 367 rwlock_t sk_callback_lock; 368 int sk_err, 369 sk_err_soft; 370 unsigned short sk_ack_backlog; 371 unsigned short sk_max_ack_backlog; 372 __u32 sk_priority; 373 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP) 374 __u32 sk_cgrp_prioidx; 375 #endif 376 struct pid *sk_peer_pid; 377 const struct cred *sk_peer_cred; 378 long sk_rcvtimeo; 379 long sk_sndtimeo; 380 void *sk_protinfo; 381 struct timer_list sk_timer; 382 ktime_t sk_stamp; 383 struct socket *sk_socket; 384 void *sk_user_data; 385 struct page_frag sk_frag; 386 struct sk_buff *sk_send_head; 387 __s32 sk_peek_off; 388 int sk_write_pending; 389 #ifdef CONFIG_SECURITY 390 void *sk_security; 391 #endif 392 __u32 sk_mark; 393 u32 sk_classid; 394 struct cg_proto *sk_cgrp; 395 void (*sk_state_change)(struct sock *sk); 396 void (*sk_data_ready)(struct sock *sk, int bytes); 397 void (*sk_write_space)(struct sock *sk); 398 void (*sk_error_report)(struct sock *sk); 399 int (*sk_backlog_rcv)(struct sock *sk, 400 struct sk_buff *skb); 401 void (*sk_destruct)(struct sock *sk); 402 }; 403 404 /* 405 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 406 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 407 * on a socket means that the socket will reuse everybody else's port 408 * without looking at the other's sk_reuse value. 409 */ 410 411 #define SK_NO_REUSE 0 412 #define SK_CAN_REUSE 1 413 #define SK_FORCE_REUSE 2 414 415 static inline int sk_peek_offset(struct sock *sk, int flags) 416 { 417 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0)) 418 return sk->sk_peek_off; 419 else 420 return 0; 421 } 422 423 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 424 { 425 if (sk->sk_peek_off >= 0) { 426 if (sk->sk_peek_off >= val) 427 sk->sk_peek_off -= val; 428 else 429 sk->sk_peek_off = 0; 430 } 431 } 432 433 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 434 { 435 if (sk->sk_peek_off >= 0) 436 sk->sk_peek_off += val; 437 } 438 439 /* 440 * Hashed lists helper routines 441 */ 442 static inline struct sock *sk_entry(const struct hlist_node *node) 443 { 444 return hlist_entry(node, struct sock, sk_node); 445 } 446 447 static inline struct sock *__sk_head(const struct hlist_head *head) 448 { 449 return hlist_entry(head->first, struct sock, sk_node); 450 } 451 452 static inline struct sock *sk_head(const struct hlist_head *head) 453 { 454 return hlist_empty(head) ? NULL : __sk_head(head); 455 } 456 457 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 458 { 459 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 460 } 461 462 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 463 { 464 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 465 } 466 467 static inline struct sock *sk_next(const struct sock *sk) 468 { 469 return sk->sk_node.next ? 470 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 471 } 472 473 static inline struct sock *sk_nulls_next(const struct sock *sk) 474 { 475 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 476 hlist_nulls_entry(sk->sk_nulls_node.next, 477 struct sock, sk_nulls_node) : 478 NULL; 479 } 480 481 static inline bool sk_unhashed(const struct sock *sk) 482 { 483 return hlist_unhashed(&sk->sk_node); 484 } 485 486 static inline bool sk_hashed(const struct sock *sk) 487 { 488 return !sk_unhashed(sk); 489 } 490 491 static inline void sk_node_init(struct hlist_node *node) 492 { 493 node->pprev = NULL; 494 } 495 496 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 497 { 498 node->pprev = NULL; 499 } 500 501 static inline void __sk_del_node(struct sock *sk) 502 { 503 __hlist_del(&sk->sk_node); 504 } 505 506 /* NB: equivalent to hlist_del_init_rcu */ 507 static inline bool __sk_del_node_init(struct sock *sk) 508 { 509 if (sk_hashed(sk)) { 510 __sk_del_node(sk); 511 sk_node_init(&sk->sk_node); 512 return true; 513 } 514 return false; 515 } 516 517 /* Grab socket reference count. This operation is valid only 518 when sk is ALREADY grabbed f.e. it is found in hash table 519 or a list and the lookup is made under lock preventing hash table 520 modifications. 521 */ 522 523 static inline void sock_hold(struct sock *sk) 524 { 525 atomic_inc(&sk->sk_refcnt); 526 } 527 528 /* Ungrab socket in the context, which assumes that socket refcnt 529 cannot hit zero, f.e. it is true in context of any socketcall. 530 */ 531 static inline void __sock_put(struct sock *sk) 532 { 533 atomic_dec(&sk->sk_refcnt); 534 } 535 536 static inline bool sk_del_node_init(struct sock *sk) 537 { 538 bool rc = __sk_del_node_init(sk); 539 540 if (rc) { 541 /* paranoid for a while -acme */ 542 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 543 __sock_put(sk); 544 } 545 return rc; 546 } 547 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 548 549 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 550 { 551 if (sk_hashed(sk)) { 552 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 553 return true; 554 } 555 return false; 556 } 557 558 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 559 { 560 bool rc = __sk_nulls_del_node_init_rcu(sk); 561 562 if (rc) { 563 /* paranoid for a while -acme */ 564 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 565 __sock_put(sk); 566 } 567 return rc; 568 } 569 570 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 571 { 572 hlist_add_head(&sk->sk_node, list); 573 } 574 575 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 576 { 577 sock_hold(sk); 578 __sk_add_node(sk, list); 579 } 580 581 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 582 { 583 sock_hold(sk); 584 hlist_add_head_rcu(&sk->sk_node, list); 585 } 586 587 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 588 { 589 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 590 } 591 592 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 593 { 594 sock_hold(sk); 595 __sk_nulls_add_node_rcu(sk, list); 596 } 597 598 static inline void __sk_del_bind_node(struct sock *sk) 599 { 600 __hlist_del(&sk->sk_bind_node); 601 } 602 603 static inline void sk_add_bind_node(struct sock *sk, 604 struct hlist_head *list) 605 { 606 hlist_add_head(&sk->sk_bind_node, list); 607 } 608 609 #define sk_for_each(__sk, list) \ 610 hlist_for_each_entry(__sk, list, sk_node) 611 #define sk_for_each_rcu(__sk, list) \ 612 hlist_for_each_entry_rcu(__sk, list, sk_node) 613 #define sk_nulls_for_each(__sk, node, list) \ 614 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 615 #define sk_nulls_for_each_rcu(__sk, node, list) \ 616 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 617 #define sk_for_each_from(__sk) \ 618 hlist_for_each_entry_from(__sk, sk_node) 619 #define sk_nulls_for_each_from(__sk, node) \ 620 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 621 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 622 #define sk_for_each_safe(__sk, tmp, list) \ 623 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 624 #define sk_for_each_bound(__sk, list) \ 625 hlist_for_each_entry(__sk, list, sk_bind_node) 626 627 static inline struct user_namespace *sk_user_ns(struct sock *sk) 628 { 629 /* Careful only use this in a context where these parameters 630 * can not change and must all be valid, such as recvmsg from 631 * userspace. 632 */ 633 return sk->sk_socket->file->f_cred->user_ns; 634 } 635 636 /* Sock flags */ 637 enum sock_flags { 638 SOCK_DEAD, 639 SOCK_DONE, 640 SOCK_URGINLINE, 641 SOCK_KEEPOPEN, 642 SOCK_LINGER, 643 SOCK_DESTROY, 644 SOCK_BROADCAST, 645 SOCK_TIMESTAMP, 646 SOCK_ZAPPED, 647 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 648 SOCK_DBG, /* %SO_DEBUG setting */ 649 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 650 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 651 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 652 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 653 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 654 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */ 655 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */ 656 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */ 657 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 658 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */ 659 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */ 660 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */ 661 SOCK_FASYNC, /* fasync() active */ 662 SOCK_RXQ_OVFL, 663 SOCK_ZEROCOPY, /* buffers from userspace */ 664 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 665 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 666 * Will use last 4 bytes of packet sent from 667 * user-space instead. 668 */ 669 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 670 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 671 }; 672 673 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 674 { 675 nsk->sk_flags = osk->sk_flags; 676 } 677 678 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 679 { 680 __set_bit(flag, &sk->sk_flags); 681 } 682 683 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 684 { 685 __clear_bit(flag, &sk->sk_flags); 686 } 687 688 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 689 { 690 return test_bit(flag, &sk->sk_flags); 691 } 692 693 #ifdef CONFIG_NET 694 extern struct static_key memalloc_socks; 695 static inline int sk_memalloc_socks(void) 696 { 697 return static_key_false(&memalloc_socks); 698 } 699 #else 700 701 static inline int sk_memalloc_socks(void) 702 { 703 return 0; 704 } 705 706 #endif 707 708 static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask) 709 { 710 return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC); 711 } 712 713 static inline void sk_acceptq_removed(struct sock *sk) 714 { 715 sk->sk_ack_backlog--; 716 } 717 718 static inline void sk_acceptq_added(struct sock *sk) 719 { 720 sk->sk_ack_backlog++; 721 } 722 723 static inline bool sk_acceptq_is_full(const struct sock *sk) 724 { 725 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 726 } 727 728 /* 729 * Compute minimal free write space needed to queue new packets. 730 */ 731 static inline int sk_stream_min_wspace(const struct sock *sk) 732 { 733 return sk->sk_wmem_queued >> 1; 734 } 735 736 static inline int sk_stream_wspace(const struct sock *sk) 737 { 738 return sk->sk_sndbuf - sk->sk_wmem_queued; 739 } 740 741 extern void sk_stream_write_space(struct sock *sk); 742 743 static inline bool sk_stream_memory_free(const struct sock *sk) 744 { 745 return sk->sk_wmem_queued < sk->sk_sndbuf; 746 } 747 748 /* OOB backlog add */ 749 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 750 { 751 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 752 skb_dst_force(skb); 753 754 if (!sk->sk_backlog.tail) 755 sk->sk_backlog.head = skb; 756 else 757 sk->sk_backlog.tail->next = skb; 758 759 sk->sk_backlog.tail = skb; 760 skb->next = NULL; 761 } 762 763 /* 764 * Take into account size of receive queue and backlog queue 765 * Do not take into account this skb truesize, 766 * to allow even a single big packet to come. 767 */ 768 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb, 769 unsigned int limit) 770 { 771 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 772 773 return qsize > limit; 774 } 775 776 /* The per-socket spinlock must be held here. */ 777 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 778 unsigned int limit) 779 { 780 if (sk_rcvqueues_full(sk, skb, limit)) 781 return -ENOBUFS; 782 783 __sk_add_backlog(sk, skb); 784 sk->sk_backlog.len += skb->truesize; 785 return 0; 786 } 787 788 extern int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 789 790 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 791 { 792 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 793 return __sk_backlog_rcv(sk, skb); 794 795 return sk->sk_backlog_rcv(sk, skb); 796 } 797 798 static inline void sock_rps_record_flow(const struct sock *sk) 799 { 800 #ifdef CONFIG_RPS 801 struct rps_sock_flow_table *sock_flow_table; 802 803 rcu_read_lock(); 804 sock_flow_table = rcu_dereference(rps_sock_flow_table); 805 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash); 806 rcu_read_unlock(); 807 #endif 808 } 809 810 static inline void sock_rps_reset_flow(const struct sock *sk) 811 { 812 #ifdef CONFIG_RPS 813 struct rps_sock_flow_table *sock_flow_table; 814 815 rcu_read_lock(); 816 sock_flow_table = rcu_dereference(rps_sock_flow_table); 817 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash); 818 rcu_read_unlock(); 819 #endif 820 } 821 822 static inline void sock_rps_save_rxhash(struct sock *sk, 823 const struct sk_buff *skb) 824 { 825 #ifdef CONFIG_RPS 826 if (unlikely(sk->sk_rxhash != skb->rxhash)) { 827 sock_rps_reset_flow(sk); 828 sk->sk_rxhash = skb->rxhash; 829 } 830 #endif 831 } 832 833 static inline void sock_rps_reset_rxhash(struct sock *sk) 834 { 835 #ifdef CONFIG_RPS 836 sock_rps_reset_flow(sk); 837 sk->sk_rxhash = 0; 838 #endif 839 } 840 841 #define sk_wait_event(__sk, __timeo, __condition) \ 842 ({ int __rc; \ 843 release_sock(__sk); \ 844 __rc = __condition; \ 845 if (!__rc) { \ 846 *(__timeo) = schedule_timeout(*(__timeo)); \ 847 } \ 848 lock_sock(__sk); \ 849 __rc = __condition; \ 850 __rc; \ 851 }) 852 853 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 854 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 855 extern void sk_stream_wait_close(struct sock *sk, long timeo_p); 856 extern int sk_stream_error(struct sock *sk, int flags, int err); 857 extern void sk_stream_kill_queues(struct sock *sk); 858 extern void sk_set_memalloc(struct sock *sk); 859 extern void sk_clear_memalloc(struct sock *sk); 860 861 extern int sk_wait_data(struct sock *sk, long *timeo); 862 863 struct request_sock_ops; 864 struct timewait_sock_ops; 865 struct inet_hashinfo; 866 struct raw_hashinfo; 867 struct module; 868 869 /* 870 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes 871 * un-modified. Special care is taken when initializing object to zero. 872 */ 873 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 874 { 875 if (offsetof(struct sock, sk_node.next) != 0) 876 memset(sk, 0, offsetof(struct sock, sk_node.next)); 877 memset(&sk->sk_node.pprev, 0, 878 size - offsetof(struct sock, sk_node.pprev)); 879 } 880 881 /* Networking protocol blocks we attach to sockets. 882 * socket layer -> transport layer interface 883 * transport -> network interface is defined by struct inet_proto 884 */ 885 struct proto { 886 void (*close)(struct sock *sk, 887 long timeout); 888 int (*connect)(struct sock *sk, 889 struct sockaddr *uaddr, 890 int addr_len); 891 int (*disconnect)(struct sock *sk, int flags); 892 893 struct sock * (*accept)(struct sock *sk, int flags, int *err); 894 895 int (*ioctl)(struct sock *sk, int cmd, 896 unsigned long arg); 897 int (*init)(struct sock *sk); 898 void (*destroy)(struct sock *sk); 899 void (*shutdown)(struct sock *sk, int how); 900 int (*setsockopt)(struct sock *sk, int level, 901 int optname, char __user *optval, 902 unsigned int optlen); 903 int (*getsockopt)(struct sock *sk, int level, 904 int optname, char __user *optval, 905 int __user *option); 906 #ifdef CONFIG_COMPAT 907 int (*compat_setsockopt)(struct sock *sk, 908 int level, 909 int optname, char __user *optval, 910 unsigned int optlen); 911 int (*compat_getsockopt)(struct sock *sk, 912 int level, 913 int optname, char __user *optval, 914 int __user *option); 915 int (*compat_ioctl)(struct sock *sk, 916 unsigned int cmd, unsigned long arg); 917 #endif 918 int (*sendmsg)(struct kiocb *iocb, struct sock *sk, 919 struct msghdr *msg, size_t len); 920 int (*recvmsg)(struct kiocb *iocb, struct sock *sk, 921 struct msghdr *msg, 922 size_t len, int noblock, int flags, 923 int *addr_len); 924 int (*sendpage)(struct sock *sk, struct page *page, 925 int offset, size_t size, int flags); 926 int (*bind)(struct sock *sk, 927 struct sockaddr *uaddr, int addr_len); 928 929 int (*backlog_rcv) (struct sock *sk, 930 struct sk_buff *skb); 931 932 void (*release_cb)(struct sock *sk); 933 void (*mtu_reduced)(struct sock *sk); 934 935 /* Keeping track of sk's, looking them up, and port selection methods. */ 936 void (*hash)(struct sock *sk); 937 void (*unhash)(struct sock *sk); 938 void (*rehash)(struct sock *sk); 939 int (*get_port)(struct sock *sk, unsigned short snum); 940 void (*clear_sk)(struct sock *sk, int size); 941 942 /* Keeping track of sockets in use */ 943 #ifdef CONFIG_PROC_FS 944 unsigned int inuse_idx; 945 #endif 946 947 /* Memory pressure */ 948 void (*enter_memory_pressure)(struct sock *sk); 949 atomic_long_t *memory_allocated; /* Current allocated memory. */ 950 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 951 /* 952 * Pressure flag: try to collapse. 953 * Technical note: it is used by multiple contexts non atomically. 954 * All the __sk_mem_schedule() is of this nature: accounting 955 * is strict, actions are advisory and have some latency. 956 */ 957 int *memory_pressure; 958 long *sysctl_mem; 959 int *sysctl_wmem; 960 int *sysctl_rmem; 961 int max_header; 962 bool no_autobind; 963 964 struct kmem_cache *slab; 965 unsigned int obj_size; 966 int slab_flags; 967 968 struct percpu_counter *orphan_count; 969 970 struct request_sock_ops *rsk_prot; 971 struct timewait_sock_ops *twsk_prot; 972 973 union { 974 struct inet_hashinfo *hashinfo; 975 struct udp_table *udp_table; 976 struct raw_hashinfo *raw_hash; 977 } h; 978 979 struct module *owner; 980 981 char name[32]; 982 983 struct list_head node; 984 #ifdef SOCK_REFCNT_DEBUG 985 atomic_t socks; 986 #endif 987 #ifdef CONFIG_MEMCG_KMEM 988 /* 989 * cgroup specific init/deinit functions. Called once for all 990 * protocols that implement it, from cgroups populate function. 991 * This function has to setup any files the protocol want to 992 * appear in the kmem cgroup filesystem. 993 */ 994 int (*init_cgroup)(struct mem_cgroup *memcg, 995 struct cgroup_subsys *ss); 996 void (*destroy_cgroup)(struct mem_cgroup *memcg); 997 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg); 998 #endif 999 }; 1000 1001 /* 1002 * Bits in struct cg_proto.flags 1003 */ 1004 enum cg_proto_flags { 1005 /* Currently active and new sockets should be assigned to cgroups */ 1006 MEMCG_SOCK_ACTIVE, 1007 /* It was ever activated; we must disarm static keys on destruction */ 1008 MEMCG_SOCK_ACTIVATED, 1009 }; 1010 1011 struct cg_proto { 1012 void (*enter_memory_pressure)(struct sock *sk); 1013 struct res_counter *memory_allocated; /* Current allocated memory. */ 1014 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1015 int *memory_pressure; 1016 long *sysctl_mem; 1017 unsigned long flags; 1018 /* 1019 * memcg field is used to find which memcg we belong directly 1020 * Each memcg struct can hold more than one cg_proto, so container_of 1021 * won't really cut. 1022 * 1023 * The elegant solution would be having an inverse function to 1024 * proto_cgroup in struct proto, but that means polluting the structure 1025 * for everybody, instead of just for memcg users. 1026 */ 1027 struct mem_cgroup *memcg; 1028 }; 1029 1030 extern int proto_register(struct proto *prot, int alloc_slab); 1031 extern void proto_unregister(struct proto *prot); 1032 1033 static inline bool memcg_proto_active(struct cg_proto *cg_proto) 1034 { 1035 return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags); 1036 } 1037 1038 static inline bool memcg_proto_activated(struct cg_proto *cg_proto) 1039 { 1040 return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags); 1041 } 1042 1043 #ifdef SOCK_REFCNT_DEBUG 1044 static inline void sk_refcnt_debug_inc(struct sock *sk) 1045 { 1046 atomic_inc(&sk->sk_prot->socks); 1047 } 1048 1049 static inline void sk_refcnt_debug_dec(struct sock *sk) 1050 { 1051 atomic_dec(&sk->sk_prot->socks); 1052 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1053 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1054 } 1055 1056 static inline void sk_refcnt_debug_release(const struct sock *sk) 1057 { 1058 if (atomic_read(&sk->sk_refcnt) != 1) 1059 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1060 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 1061 } 1062 #else /* SOCK_REFCNT_DEBUG */ 1063 #define sk_refcnt_debug_inc(sk) do { } while (0) 1064 #define sk_refcnt_debug_dec(sk) do { } while (0) 1065 #define sk_refcnt_debug_release(sk) do { } while (0) 1066 #endif /* SOCK_REFCNT_DEBUG */ 1067 1068 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET) 1069 extern struct static_key memcg_socket_limit_enabled; 1070 static inline struct cg_proto *parent_cg_proto(struct proto *proto, 1071 struct cg_proto *cg_proto) 1072 { 1073 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg)); 1074 } 1075 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled) 1076 #else 1077 #define mem_cgroup_sockets_enabled 0 1078 static inline struct cg_proto *parent_cg_proto(struct proto *proto, 1079 struct cg_proto *cg_proto) 1080 { 1081 return NULL; 1082 } 1083 #endif 1084 1085 1086 static inline bool sk_has_memory_pressure(const struct sock *sk) 1087 { 1088 return sk->sk_prot->memory_pressure != NULL; 1089 } 1090 1091 static inline bool sk_under_memory_pressure(const struct sock *sk) 1092 { 1093 if (!sk->sk_prot->memory_pressure) 1094 return false; 1095 1096 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1097 return !!*sk->sk_cgrp->memory_pressure; 1098 1099 return !!*sk->sk_prot->memory_pressure; 1100 } 1101 1102 static inline void sk_leave_memory_pressure(struct sock *sk) 1103 { 1104 int *memory_pressure = sk->sk_prot->memory_pressure; 1105 1106 if (!memory_pressure) 1107 return; 1108 1109 if (*memory_pressure) 1110 *memory_pressure = 0; 1111 1112 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1113 struct cg_proto *cg_proto = sk->sk_cgrp; 1114 struct proto *prot = sk->sk_prot; 1115 1116 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1117 if (*cg_proto->memory_pressure) 1118 *cg_proto->memory_pressure = 0; 1119 } 1120 1121 } 1122 1123 static inline void sk_enter_memory_pressure(struct sock *sk) 1124 { 1125 if (!sk->sk_prot->enter_memory_pressure) 1126 return; 1127 1128 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1129 struct cg_proto *cg_proto = sk->sk_cgrp; 1130 struct proto *prot = sk->sk_prot; 1131 1132 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1133 cg_proto->enter_memory_pressure(sk); 1134 } 1135 1136 sk->sk_prot->enter_memory_pressure(sk); 1137 } 1138 1139 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1140 { 1141 long *prot = sk->sk_prot->sysctl_mem; 1142 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1143 prot = sk->sk_cgrp->sysctl_mem; 1144 return prot[index]; 1145 } 1146 1147 static inline void memcg_memory_allocated_add(struct cg_proto *prot, 1148 unsigned long amt, 1149 int *parent_status) 1150 { 1151 struct res_counter *fail; 1152 int ret; 1153 1154 ret = res_counter_charge_nofail(prot->memory_allocated, 1155 amt << PAGE_SHIFT, &fail); 1156 if (ret < 0) 1157 *parent_status = OVER_LIMIT; 1158 } 1159 1160 static inline void memcg_memory_allocated_sub(struct cg_proto *prot, 1161 unsigned long amt) 1162 { 1163 res_counter_uncharge(prot->memory_allocated, amt << PAGE_SHIFT); 1164 } 1165 1166 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot) 1167 { 1168 u64 ret; 1169 ret = res_counter_read_u64(prot->memory_allocated, RES_USAGE); 1170 return ret >> PAGE_SHIFT; 1171 } 1172 1173 static inline long 1174 sk_memory_allocated(const struct sock *sk) 1175 { 1176 struct proto *prot = sk->sk_prot; 1177 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1178 return memcg_memory_allocated_read(sk->sk_cgrp); 1179 1180 return atomic_long_read(prot->memory_allocated); 1181 } 1182 1183 static inline long 1184 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status) 1185 { 1186 struct proto *prot = sk->sk_prot; 1187 1188 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1189 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status); 1190 /* update the root cgroup regardless */ 1191 atomic_long_add_return(amt, prot->memory_allocated); 1192 return memcg_memory_allocated_read(sk->sk_cgrp); 1193 } 1194 1195 return atomic_long_add_return(amt, prot->memory_allocated); 1196 } 1197 1198 static inline void 1199 sk_memory_allocated_sub(struct sock *sk, int amt) 1200 { 1201 struct proto *prot = sk->sk_prot; 1202 1203 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1204 memcg_memory_allocated_sub(sk->sk_cgrp, amt); 1205 1206 atomic_long_sub(amt, prot->memory_allocated); 1207 } 1208 1209 static inline void sk_sockets_allocated_dec(struct sock *sk) 1210 { 1211 struct proto *prot = sk->sk_prot; 1212 1213 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1214 struct cg_proto *cg_proto = sk->sk_cgrp; 1215 1216 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1217 percpu_counter_dec(cg_proto->sockets_allocated); 1218 } 1219 1220 percpu_counter_dec(prot->sockets_allocated); 1221 } 1222 1223 static inline void sk_sockets_allocated_inc(struct sock *sk) 1224 { 1225 struct proto *prot = sk->sk_prot; 1226 1227 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1228 struct cg_proto *cg_proto = sk->sk_cgrp; 1229 1230 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1231 percpu_counter_inc(cg_proto->sockets_allocated); 1232 } 1233 1234 percpu_counter_inc(prot->sockets_allocated); 1235 } 1236 1237 static inline int 1238 sk_sockets_allocated_read_positive(struct sock *sk) 1239 { 1240 struct proto *prot = sk->sk_prot; 1241 1242 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1243 return percpu_counter_read_positive(sk->sk_cgrp->sockets_allocated); 1244 1245 return percpu_counter_read_positive(prot->sockets_allocated); 1246 } 1247 1248 static inline int 1249 proto_sockets_allocated_sum_positive(struct proto *prot) 1250 { 1251 return percpu_counter_sum_positive(prot->sockets_allocated); 1252 } 1253 1254 static inline long 1255 proto_memory_allocated(struct proto *prot) 1256 { 1257 return atomic_long_read(prot->memory_allocated); 1258 } 1259 1260 static inline bool 1261 proto_memory_pressure(struct proto *prot) 1262 { 1263 if (!prot->memory_pressure) 1264 return false; 1265 return !!*prot->memory_pressure; 1266 } 1267 1268 1269 #ifdef CONFIG_PROC_FS 1270 /* Called with local bh disabled */ 1271 extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1272 extern int sock_prot_inuse_get(struct net *net, struct proto *proto); 1273 #else 1274 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1275 int inc) 1276 { 1277 } 1278 #endif 1279 1280 1281 /* With per-bucket locks this operation is not-atomic, so that 1282 * this version is not worse. 1283 */ 1284 static inline void __sk_prot_rehash(struct sock *sk) 1285 { 1286 sk->sk_prot->unhash(sk); 1287 sk->sk_prot->hash(sk); 1288 } 1289 1290 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 1291 1292 /* About 10 seconds */ 1293 #define SOCK_DESTROY_TIME (10*HZ) 1294 1295 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1296 #define PROT_SOCK 1024 1297 1298 #define SHUTDOWN_MASK 3 1299 #define RCV_SHUTDOWN 1 1300 #define SEND_SHUTDOWN 2 1301 1302 #define SOCK_SNDBUF_LOCK 1 1303 #define SOCK_RCVBUF_LOCK 2 1304 #define SOCK_BINDADDR_LOCK 4 1305 #define SOCK_BINDPORT_LOCK 8 1306 1307 /* sock_iocb: used to kick off async processing of socket ios */ 1308 struct sock_iocb { 1309 struct list_head list; 1310 1311 int flags; 1312 int size; 1313 struct socket *sock; 1314 struct sock *sk; 1315 struct scm_cookie *scm; 1316 struct msghdr *msg, async_msg; 1317 struct kiocb *kiocb; 1318 }; 1319 1320 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb) 1321 { 1322 return (struct sock_iocb *)iocb->private; 1323 } 1324 1325 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si) 1326 { 1327 return si->kiocb; 1328 } 1329 1330 struct socket_alloc { 1331 struct socket socket; 1332 struct inode vfs_inode; 1333 }; 1334 1335 static inline struct socket *SOCKET_I(struct inode *inode) 1336 { 1337 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1338 } 1339 1340 static inline struct inode *SOCK_INODE(struct socket *socket) 1341 { 1342 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1343 } 1344 1345 /* 1346 * Functions for memory accounting 1347 */ 1348 extern int __sk_mem_schedule(struct sock *sk, int size, int kind); 1349 extern void __sk_mem_reclaim(struct sock *sk); 1350 1351 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 1352 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1353 #define SK_MEM_SEND 0 1354 #define SK_MEM_RECV 1 1355 1356 static inline int sk_mem_pages(int amt) 1357 { 1358 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1359 } 1360 1361 static inline bool sk_has_account(struct sock *sk) 1362 { 1363 /* return true if protocol supports memory accounting */ 1364 return !!sk->sk_prot->memory_allocated; 1365 } 1366 1367 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1368 { 1369 if (!sk_has_account(sk)) 1370 return true; 1371 return size <= sk->sk_forward_alloc || 1372 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1373 } 1374 1375 static inline bool 1376 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1377 { 1378 if (!sk_has_account(sk)) 1379 return true; 1380 return size<= sk->sk_forward_alloc || 1381 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1382 skb_pfmemalloc(skb); 1383 } 1384 1385 static inline void sk_mem_reclaim(struct sock *sk) 1386 { 1387 if (!sk_has_account(sk)) 1388 return; 1389 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1390 __sk_mem_reclaim(sk); 1391 } 1392 1393 static inline void sk_mem_reclaim_partial(struct sock *sk) 1394 { 1395 if (!sk_has_account(sk)) 1396 return; 1397 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1398 __sk_mem_reclaim(sk); 1399 } 1400 1401 static inline void sk_mem_charge(struct sock *sk, int size) 1402 { 1403 if (!sk_has_account(sk)) 1404 return; 1405 sk->sk_forward_alloc -= size; 1406 } 1407 1408 static inline void sk_mem_uncharge(struct sock *sk, int size) 1409 { 1410 if (!sk_has_account(sk)) 1411 return; 1412 sk->sk_forward_alloc += size; 1413 } 1414 1415 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1416 { 1417 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1418 sk->sk_wmem_queued -= skb->truesize; 1419 sk_mem_uncharge(sk, skb->truesize); 1420 __kfree_skb(skb); 1421 } 1422 1423 /* Used by processes to "lock" a socket state, so that 1424 * interrupts and bottom half handlers won't change it 1425 * from under us. It essentially blocks any incoming 1426 * packets, so that we won't get any new data or any 1427 * packets that change the state of the socket. 1428 * 1429 * While locked, BH processing will add new packets to 1430 * the backlog queue. This queue is processed by the 1431 * owner of the socket lock right before it is released. 1432 * 1433 * Since ~2.3.5 it is also exclusive sleep lock serializing 1434 * accesses from user process context. 1435 */ 1436 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned) 1437 1438 /* 1439 * Macro so as to not evaluate some arguments when 1440 * lockdep is not enabled. 1441 * 1442 * Mark both the sk_lock and the sk_lock.slock as a 1443 * per-address-family lock class. 1444 */ 1445 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1446 do { \ 1447 sk->sk_lock.owned = 0; \ 1448 init_waitqueue_head(&sk->sk_lock.wq); \ 1449 spin_lock_init(&(sk)->sk_lock.slock); \ 1450 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1451 sizeof((sk)->sk_lock)); \ 1452 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1453 (skey), (sname)); \ 1454 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1455 } while (0) 1456 1457 extern void lock_sock_nested(struct sock *sk, int subclass); 1458 1459 static inline void lock_sock(struct sock *sk) 1460 { 1461 lock_sock_nested(sk, 0); 1462 } 1463 1464 extern void release_sock(struct sock *sk); 1465 1466 /* BH context may only use the following locking interface. */ 1467 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1468 #define bh_lock_sock_nested(__sk) \ 1469 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1470 SINGLE_DEPTH_NESTING) 1471 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1472 1473 extern bool lock_sock_fast(struct sock *sk); 1474 /** 1475 * unlock_sock_fast - complement of lock_sock_fast 1476 * @sk: socket 1477 * @slow: slow mode 1478 * 1479 * fast unlock socket for user context. 1480 * If slow mode is on, we call regular release_sock() 1481 */ 1482 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1483 { 1484 if (slow) 1485 release_sock(sk); 1486 else 1487 spin_unlock_bh(&sk->sk_lock.slock); 1488 } 1489 1490 1491 extern struct sock *sk_alloc(struct net *net, int family, 1492 gfp_t priority, 1493 struct proto *prot); 1494 extern void sk_free(struct sock *sk); 1495 extern void sk_release_kernel(struct sock *sk); 1496 extern struct sock *sk_clone_lock(const struct sock *sk, 1497 const gfp_t priority); 1498 1499 extern struct sk_buff *sock_wmalloc(struct sock *sk, 1500 unsigned long size, int force, 1501 gfp_t priority); 1502 extern struct sk_buff *sock_rmalloc(struct sock *sk, 1503 unsigned long size, int force, 1504 gfp_t priority); 1505 extern void sock_wfree(struct sk_buff *skb); 1506 extern void sock_rfree(struct sk_buff *skb); 1507 extern void sock_edemux(struct sk_buff *skb); 1508 1509 extern int sock_setsockopt(struct socket *sock, int level, 1510 int op, char __user *optval, 1511 unsigned int optlen); 1512 1513 extern int sock_getsockopt(struct socket *sock, int level, 1514 int op, char __user *optval, 1515 int __user *optlen); 1516 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk, 1517 unsigned long size, 1518 int noblock, 1519 int *errcode); 1520 extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk, 1521 unsigned long header_len, 1522 unsigned long data_len, 1523 int noblock, 1524 int *errcode); 1525 extern void *sock_kmalloc(struct sock *sk, int size, 1526 gfp_t priority); 1527 extern void sock_kfree_s(struct sock *sk, void *mem, int size); 1528 extern void sk_send_sigurg(struct sock *sk); 1529 1530 /* 1531 * Functions to fill in entries in struct proto_ops when a protocol 1532 * does not implement a particular function. 1533 */ 1534 extern int sock_no_bind(struct socket *, 1535 struct sockaddr *, int); 1536 extern int sock_no_connect(struct socket *, 1537 struct sockaddr *, int, int); 1538 extern int sock_no_socketpair(struct socket *, 1539 struct socket *); 1540 extern int sock_no_accept(struct socket *, 1541 struct socket *, int); 1542 extern int sock_no_getname(struct socket *, 1543 struct sockaddr *, int *, int); 1544 extern unsigned int sock_no_poll(struct file *, struct socket *, 1545 struct poll_table_struct *); 1546 extern int sock_no_ioctl(struct socket *, unsigned int, 1547 unsigned long); 1548 extern int sock_no_listen(struct socket *, int); 1549 extern int sock_no_shutdown(struct socket *, int); 1550 extern int sock_no_getsockopt(struct socket *, int , int, 1551 char __user *, int __user *); 1552 extern int sock_no_setsockopt(struct socket *, int, int, 1553 char __user *, unsigned int); 1554 extern int sock_no_sendmsg(struct kiocb *, struct socket *, 1555 struct msghdr *, size_t); 1556 extern int sock_no_recvmsg(struct kiocb *, struct socket *, 1557 struct msghdr *, size_t, int); 1558 extern int sock_no_mmap(struct file *file, 1559 struct socket *sock, 1560 struct vm_area_struct *vma); 1561 extern ssize_t sock_no_sendpage(struct socket *sock, 1562 struct page *page, 1563 int offset, size_t size, 1564 int flags); 1565 1566 /* 1567 * Functions to fill in entries in struct proto_ops when a protocol 1568 * uses the inet style. 1569 */ 1570 extern int sock_common_getsockopt(struct socket *sock, int level, int optname, 1571 char __user *optval, int __user *optlen); 1572 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock, 1573 struct msghdr *msg, size_t size, int flags); 1574 extern int sock_common_setsockopt(struct socket *sock, int level, int optname, 1575 char __user *optval, unsigned int optlen); 1576 extern int compat_sock_common_getsockopt(struct socket *sock, int level, 1577 int optname, char __user *optval, int __user *optlen); 1578 extern int compat_sock_common_setsockopt(struct socket *sock, int level, 1579 int optname, char __user *optval, unsigned int optlen); 1580 1581 extern void sk_common_release(struct sock *sk); 1582 1583 /* 1584 * Default socket callbacks and setup code 1585 */ 1586 1587 /* Initialise core socket variables */ 1588 extern void sock_init_data(struct socket *sock, struct sock *sk); 1589 1590 extern void sk_filter_release_rcu(struct rcu_head *rcu); 1591 1592 /** 1593 * sk_filter_release - release a socket filter 1594 * @fp: filter to remove 1595 * 1596 * Remove a filter from a socket and release its resources. 1597 */ 1598 1599 static inline void sk_filter_release(struct sk_filter *fp) 1600 { 1601 if (atomic_dec_and_test(&fp->refcnt)) 1602 call_rcu(&fp->rcu, sk_filter_release_rcu); 1603 } 1604 1605 static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) 1606 { 1607 unsigned int size = sk_filter_len(fp); 1608 1609 atomic_sub(size, &sk->sk_omem_alloc); 1610 sk_filter_release(fp); 1611 } 1612 1613 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp) 1614 { 1615 atomic_inc(&fp->refcnt); 1616 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc); 1617 } 1618 1619 /* 1620 * Socket reference counting postulates. 1621 * 1622 * * Each user of socket SHOULD hold a reference count. 1623 * * Each access point to socket (an hash table bucket, reference from a list, 1624 * running timer, skb in flight MUST hold a reference count. 1625 * * When reference count hits 0, it means it will never increase back. 1626 * * When reference count hits 0, it means that no references from 1627 * outside exist to this socket and current process on current CPU 1628 * is last user and may/should destroy this socket. 1629 * * sk_free is called from any context: process, BH, IRQ. When 1630 * it is called, socket has no references from outside -> sk_free 1631 * may release descendant resources allocated by the socket, but 1632 * to the time when it is called, socket is NOT referenced by any 1633 * hash tables, lists etc. 1634 * * Packets, delivered from outside (from network or from another process) 1635 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1636 * when they sit in queue. Otherwise, packets will leak to hole, when 1637 * socket is looked up by one cpu and unhasing is made by another CPU. 1638 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1639 * (leak to backlog). Packet socket does all the processing inside 1640 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1641 * use separate SMP lock, so that they are prone too. 1642 */ 1643 1644 /* Ungrab socket and destroy it, if it was the last reference. */ 1645 static inline void sock_put(struct sock *sk) 1646 { 1647 if (atomic_dec_and_test(&sk->sk_refcnt)) 1648 sk_free(sk); 1649 } 1650 1651 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1652 const int nested); 1653 1654 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1655 { 1656 sk->sk_tx_queue_mapping = tx_queue; 1657 } 1658 1659 static inline void sk_tx_queue_clear(struct sock *sk) 1660 { 1661 sk->sk_tx_queue_mapping = -1; 1662 } 1663 1664 static inline int sk_tx_queue_get(const struct sock *sk) 1665 { 1666 return sk ? sk->sk_tx_queue_mapping : -1; 1667 } 1668 1669 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1670 { 1671 sk_tx_queue_clear(sk); 1672 sk->sk_socket = sock; 1673 } 1674 1675 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1676 { 1677 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1678 return &rcu_dereference_raw(sk->sk_wq)->wait; 1679 } 1680 /* Detach socket from process context. 1681 * Announce socket dead, detach it from wait queue and inode. 1682 * Note that parent inode held reference count on this struct sock, 1683 * we do not release it in this function, because protocol 1684 * probably wants some additional cleanups or even continuing 1685 * to work with this socket (TCP). 1686 */ 1687 static inline void sock_orphan(struct sock *sk) 1688 { 1689 write_lock_bh(&sk->sk_callback_lock); 1690 sock_set_flag(sk, SOCK_DEAD); 1691 sk_set_socket(sk, NULL); 1692 sk->sk_wq = NULL; 1693 write_unlock_bh(&sk->sk_callback_lock); 1694 } 1695 1696 static inline void sock_graft(struct sock *sk, struct socket *parent) 1697 { 1698 write_lock_bh(&sk->sk_callback_lock); 1699 sk->sk_wq = parent->wq; 1700 parent->sk = sk; 1701 sk_set_socket(sk, parent); 1702 security_sock_graft(sk, parent); 1703 write_unlock_bh(&sk->sk_callback_lock); 1704 } 1705 1706 extern kuid_t sock_i_uid(struct sock *sk); 1707 extern unsigned long sock_i_ino(struct sock *sk); 1708 1709 static inline struct dst_entry * 1710 __sk_dst_get(struct sock *sk) 1711 { 1712 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) || 1713 lockdep_is_held(&sk->sk_lock.slock)); 1714 } 1715 1716 static inline struct dst_entry * 1717 sk_dst_get(struct sock *sk) 1718 { 1719 struct dst_entry *dst; 1720 1721 rcu_read_lock(); 1722 dst = rcu_dereference(sk->sk_dst_cache); 1723 if (dst) 1724 dst_hold(dst); 1725 rcu_read_unlock(); 1726 return dst; 1727 } 1728 1729 extern void sk_reset_txq(struct sock *sk); 1730 1731 static inline void dst_negative_advice(struct sock *sk) 1732 { 1733 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1734 1735 if (dst && dst->ops->negative_advice) { 1736 ndst = dst->ops->negative_advice(dst); 1737 1738 if (ndst != dst) { 1739 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1740 sk_reset_txq(sk); 1741 } 1742 } 1743 } 1744 1745 static inline void 1746 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1747 { 1748 struct dst_entry *old_dst; 1749 1750 sk_tx_queue_clear(sk); 1751 /* 1752 * This can be called while sk is owned by the caller only, 1753 * with no state that can be checked in a rcu_dereference_check() cond 1754 */ 1755 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1756 rcu_assign_pointer(sk->sk_dst_cache, dst); 1757 dst_release(old_dst); 1758 } 1759 1760 static inline void 1761 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1762 { 1763 spin_lock(&sk->sk_dst_lock); 1764 __sk_dst_set(sk, dst); 1765 spin_unlock(&sk->sk_dst_lock); 1766 } 1767 1768 static inline void 1769 __sk_dst_reset(struct sock *sk) 1770 { 1771 __sk_dst_set(sk, NULL); 1772 } 1773 1774 static inline void 1775 sk_dst_reset(struct sock *sk) 1776 { 1777 spin_lock(&sk->sk_dst_lock); 1778 __sk_dst_reset(sk); 1779 spin_unlock(&sk->sk_dst_lock); 1780 } 1781 1782 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1783 1784 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1785 1786 static inline bool sk_can_gso(const struct sock *sk) 1787 { 1788 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1789 } 1790 1791 extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1792 1793 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1794 { 1795 sk->sk_route_nocaps |= flags; 1796 sk->sk_route_caps &= ~flags; 1797 } 1798 1799 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1800 char __user *from, char *to, 1801 int copy, int offset) 1802 { 1803 if (skb->ip_summed == CHECKSUM_NONE) { 1804 int err = 0; 1805 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err); 1806 if (err) 1807 return err; 1808 skb->csum = csum_block_add(skb->csum, csum, offset); 1809 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1810 if (!access_ok(VERIFY_READ, from, copy) || 1811 __copy_from_user_nocache(to, from, copy)) 1812 return -EFAULT; 1813 } else if (copy_from_user(to, from, copy)) 1814 return -EFAULT; 1815 1816 return 0; 1817 } 1818 1819 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1820 char __user *from, int copy) 1821 { 1822 int err, offset = skb->len; 1823 1824 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1825 copy, offset); 1826 if (err) 1827 __skb_trim(skb, offset); 1828 1829 return err; 1830 } 1831 1832 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from, 1833 struct sk_buff *skb, 1834 struct page *page, 1835 int off, int copy) 1836 { 1837 int err; 1838 1839 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1840 copy, skb->len); 1841 if (err) 1842 return err; 1843 1844 skb->len += copy; 1845 skb->data_len += copy; 1846 skb->truesize += copy; 1847 sk->sk_wmem_queued += copy; 1848 sk_mem_charge(sk, copy); 1849 return 0; 1850 } 1851 1852 static inline int skb_copy_to_page(struct sock *sk, char __user *from, 1853 struct sk_buff *skb, struct page *page, 1854 int off, int copy) 1855 { 1856 if (skb->ip_summed == CHECKSUM_NONE) { 1857 int err = 0; 1858 __wsum csum = csum_and_copy_from_user(from, 1859 page_address(page) + off, 1860 copy, 0, &err); 1861 if (err) 1862 return err; 1863 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1864 } else if (copy_from_user(page_address(page) + off, from, copy)) 1865 return -EFAULT; 1866 1867 skb->len += copy; 1868 skb->data_len += copy; 1869 skb->truesize += copy; 1870 sk->sk_wmem_queued += copy; 1871 sk_mem_charge(sk, copy); 1872 return 0; 1873 } 1874 1875 /** 1876 * sk_wmem_alloc_get - returns write allocations 1877 * @sk: socket 1878 * 1879 * Returns sk_wmem_alloc minus initial offset of one 1880 */ 1881 static inline int sk_wmem_alloc_get(const struct sock *sk) 1882 { 1883 return atomic_read(&sk->sk_wmem_alloc) - 1; 1884 } 1885 1886 /** 1887 * sk_rmem_alloc_get - returns read allocations 1888 * @sk: socket 1889 * 1890 * Returns sk_rmem_alloc 1891 */ 1892 static inline int sk_rmem_alloc_get(const struct sock *sk) 1893 { 1894 return atomic_read(&sk->sk_rmem_alloc); 1895 } 1896 1897 /** 1898 * sk_has_allocations - check if allocations are outstanding 1899 * @sk: socket 1900 * 1901 * Returns true if socket has write or read allocations 1902 */ 1903 static inline bool sk_has_allocations(const struct sock *sk) 1904 { 1905 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1906 } 1907 1908 /** 1909 * wq_has_sleeper - check if there are any waiting processes 1910 * @wq: struct socket_wq 1911 * 1912 * Returns true if socket_wq has waiting processes 1913 * 1914 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory 1915 * barrier call. They were added due to the race found within the tcp code. 1916 * 1917 * Consider following tcp code paths: 1918 * 1919 * CPU1 CPU2 1920 * 1921 * sys_select receive packet 1922 * ... ... 1923 * __add_wait_queue update tp->rcv_nxt 1924 * ... ... 1925 * tp->rcv_nxt check sock_def_readable 1926 * ... { 1927 * schedule rcu_read_lock(); 1928 * wq = rcu_dereference(sk->sk_wq); 1929 * if (wq && waitqueue_active(&wq->wait)) 1930 * wake_up_interruptible(&wq->wait) 1931 * ... 1932 * } 1933 * 1934 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1935 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1936 * could then endup calling schedule and sleep forever if there are no more 1937 * data on the socket. 1938 * 1939 */ 1940 static inline bool wq_has_sleeper(struct socket_wq *wq) 1941 { 1942 /* We need to be sure we are in sync with the 1943 * add_wait_queue modifications to the wait queue. 1944 * 1945 * This memory barrier is paired in the sock_poll_wait. 1946 */ 1947 smp_mb(); 1948 return wq && waitqueue_active(&wq->wait); 1949 } 1950 1951 /** 1952 * sock_poll_wait - place memory barrier behind the poll_wait call. 1953 * @filp: file 1954 * @wait_address: socket wait queue 1955 * @p: poll_table 1956 * 1957 * See the comments in the wq_has_sleeper function. 1958 */ 1959 static inline void sock_poll_wait(struct file *filp, 1960 wait_queue_head_t *wait_address, poll_table *p) 1961 { 1962 if (!poll_does_not_wait(p) && wait_address) { 1963 poll_wait(filp, wait_address, p); 1964 /* We need to be sure we are in sync with the 1965 * socket flags modification. 1966 * 1967 * This memory barrier is paired in the wq_has_sleeper. 1968 */ 1969 smp_mb(); 1970 } 1971 } 1972 1973 /* 1974 * Queue a received datagram if it will fit. Stream and sequenced 1975 * protocols can't normally use this as they need to fit buffers in 1976 * and play with them. 1977 * 1978 * Inlined as it's very short and called for pretty much every 1979 * packet ever received. 1980 */ 1981 1982 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk) 1983 { 1984 skb_orphan(skb); 1985 skb->sk = sk; 1986 skb->destructor = sock_wfree; 1987 /* 1988 * We used to take a refcount on sk, but following operation 1989 * is enough to guarantee sk_free() wont free this sock until 1990 * all in-flight packets are completed 1991 */ 1992 atomic_add(skb->truesize, &sk->sk_wmem_alloc); 1993 } 1994 1995 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1996 { 1997 skb_orphan(skb); 1998 skb->sk = sk; 1999 skb->destructor = sock_rfree; 2000 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 2001 sk_mem_charge(sk, skb->truesize); 2002 } 2003 2004 extern void sk_reset_timer(struct sock *sk, struct timer_list *timer, 2005 unsigned long expires); 2006 2007 extern void sk_stop_timer(struct sock *sk, struct timer_list *timer); 2008 2009 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2010 2011 extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 2012 2013 /* 2014 * Recover an error report and clear atomically 2015 */ 2016 2017 static inline int sock_error(struct sock *sk) 2018 { 2019 int err; 2020 if (likely(!sk->sk_err)) 2021 return 0; 2022 err = xchg(&sk->sk_err, 0); 2023 return -err; 2024 } 2025 2026 static inline unsigned long sock_wspace(struct sock *sk) 2027 { 2028 int amt = 0; 2029 2030 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 2031 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 2032 if (amt < 0) 2033 amt = 0; 2034 } 2035 return amt; 2036 } 2037 2038 static inline void sk_wake_async(struct sock *sk, int how, int band) 2039 { 2040 if (sock_flag(sk, SOCK_FASYNC)) 2041 sock_wake_async(sk->sk_socket, how, band); 2042 } 2043 2044 #define SOCK_MIN_SNDBUF 2048 2045 /* 2046 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need 2047 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak 2048 */ 2049 #define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff)) 2050 2051 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 2052 { 2053 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 2054 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 2055 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF); 2056 } 2057 } 2058 2059 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp); 2060 2061 /** 2062 * sk_page_frag - return an appropriate page_frag 2063 * @sk: socket 2064 * 2065 * If socket allocation mode allows current thread to sleep, it means its 2066 * safe to use the per task page_frag instead of the per socket one. 2067 */ 2068 static inline struct page_frag *sk_page_frag(struct sock *sk) 2069 { 2070 if (sk->sk_allocation & __GFP_WAIT) 2071 return ¤t->task_frag; 2072 2073 return &sk->sk_frag; 2074 } 2075 2076 extern bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2077 2078 /* 2079 * Default write policy as shown to user space via poll/select/SIGIO 2080 */ 2081 static inline bool sock_writeable(const struct sock *sk) 2082 { 2083 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 2084 } 2085 2086 static inline gfp_t gfp_any(void) 2087 { 2088 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2089 } 2090 2091 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2092 { 2093 return noblock ? 0 : sk->sk_rcvtimeo; 2094 } 2095 2096 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2097 { 2098 return noblock ? 0 : sk->sk_sndtimeo; 2099 } 2100 2101 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2102 { 2103 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 2104 } 2105 2106 /* Alas, with timeout socket operations are not restartable. 2107 * Compare this to poll(). 2108 */ 2109 static inline int sock_intr_errno(long timeo) 2110 { 2111 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2112 } 2113 2114 extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2115 struct sk_buff *skb); 2116 extern void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2117 struct sk_buff *skb); 2118 2119 static inline void 2120 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2121 { 2122 ktime_t kt = skb->tstamp; 2123 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2124 2125 /* 2126 * generate control messages if 2127 * - receive time stamping in software requested (SOCK_RCVTSTAMP 2128 * or SOCK_TIMESTAMPING_RX_SOFTWARE) 2129 * - software time stamp available and wanted 2130 * (SOCK_TIMESTAMPING_SOFTWARE) 2131 * - hardware time stamps available and wanted 2132 * (SOCK_TIMESTAMPING_SYS_HARDWARE or 2133 * SOCK_TIMESTAMPING_RAW_HARDWARE) 2134 */ 2135 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2136 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) || 2137 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) || 2138 (hwtstamps->hwtstamp.tv64 && 2139 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) || 2140 (hwtstamps->syststamp.tv64 && 2141 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))) 2142 __sock_recv_timestamp(msg, sk, skb); 2143 else 2144 sk->sk_stamp = kt; 2145 2146 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2147 __sock_recv_wifi_status(msg, sk, skb); 2148 } 2149 2150 extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2151 struct sk_buff *skb); 2152 2153 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2154 struct sk_buff *skb) 2155 { 2156 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2157 (1UL << SOCK_RCVTSTAMP) | \ 2158 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \ 2159 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \ 2160 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \ 2161 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE)) 2162 2163 if (sk->sk_flags & FLAGS_TS_OR_DROPS) 2164 __sock_recv_ts_and_drops(msg, sk, skb); 2165 else 2166 sk->sk_stamp = skb->tstamp; 2167 } 2168 2169 /** 2170 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2171 * @sk: socket sending this packet 2172 * @tx_flags: filled with instructions for time stamping 2173 * 2174 * Currently only depends on SOCK_TIMESTAMPING* flags. 2175 */ 2176 extern void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags); 2177 2178 /** 2179 * sk_eat_skb - Release a skb if it is no longer needed 2180 * @sk: socket to eat this skb from 2181 * @skb: socket buffer to eat 2182 * @copied_early: flag indicating whether DMA operations copied this data early 2183 * 2184 * This routine must be called with interrupts disabled or with the socket 2185 * locked so that the sk_buff queue operation is ok. 2186 */ 2187 #ifdef CONFIG_NET_DMA 2188 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early) 2189 { 2190 __skb_unlink(skb, &sk->sk_receive_queue); 2191 if (!copied_early) 2192 __kfree_skb(skb); 2193 else 2194 __skb_queue_tail(&sk->sk_async_wait_queue, skb); 2195 } 2196 #else 2197 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early) 2198 { 2199 __skb_unlink(skb, &sk->sk_receive_queue); 2200 __kfree_skb(skb); 2201 } 2202 #endif 2203 2204 static inline 2205 struct net *sock_net(const struct sock *sk) 2206 { 2207 return read_pnet(&sk->sk_net); 2208 } 2209 2210 static inline 2211 void sock_net_set(struct sock *sk, struct net *net) 2212 { 2213 write_pnet(&sk->sk_net, net); 2214 } 2215 2216 /* 2217 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace. 2218 * They should not hold a reference to a namespace in order to allow 2219 * to stop it. 2220 * Sockets after sk_change_net should be released using sk_release_kernel 2221 */ 2222 static inline void sk_change_net(struct sock *sk, struct net *net) 2223 { 2224 put_net(sock_net(sk)); 2225 sock_net_set(sk, hold_net(net)); 2226 } 2227 2228 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2229 { 2230 if (skb->sk) { 2231 struct sock *sk = skb->sk; 2232 2233 skb->destructor = NULL; 2234 skb->sk = NULL; 2235 return sk; 2236 } 2237 return NULL; 2238 } 2239 2240 extern void sock_enable_timestamp(struct sock *sk, int flag); 2241 extern int sock_get_timestamp(struct sock *, struct timeval __user *); 2242 extern int sock_get_timestampns(struct sock *, struct timespec __user *); 2243 2244 /* 2245 * Enable debug/info messages 2246 */ 2247 extern int net_msg_warn; 2248 #define NETDEBUG(fmt, args...) \ 2249 do { if (net_msg_warn) printk(fmt,##args); } while (0) 2250 2251 #define LIMIT_NETDEBUG(fmt, args...) \ 2252 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0) 2253 2254 extern __u32 sysctl_wmem_max; 2255 extern __u32 sysctl_rmem_max; 2256 2257 extern int sysctl_optmem_max; 2258 2259 extern __u32 sysctl_wmem_default; 2260 extern __u32 sysctl_rmem_default; 2261 2262 #endif /* _SOCK_H */ 2263