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/page_counter.h> 58 #include <linux/memcontrol.h> 59 #include <linux/static_key.h> 60 #include <linux/sched.h> 61 62 #include <linux/filter.h> 63 #include <linux/rculist_nulls.h> 64 #include <linux/poll.h> 65 66 #include <linux/atomic.h> 67 #include <net/dst.h> 68 #include <net/checksum.h> 69 #include <net/tcp_states.h> 70 #include <linux/net_tstamp.h> 71 72 struct cgroup; 73 struct cgroup_subsys; 74 #ifdef CONFIG_NET 75 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss); 76 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg); 77 #else 78 static inline 79 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss) 80 { 81 return 0; 82 } 83 static inline 84 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg) 85 { 86 } 87 #endif 88 /* 89 * This structure really needs to be cleaned up. 90 * Most of it is for TCP, and not used by any of 91 * the other protocols. 92 */ 93 94 /* Define this to get the SOCK_DBG debugging facility. */ 95 #define SOCK_DEBUGGING 96 #ifdef SOCK_DEBUGGING 97 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 98 printk(KERN_DEBUG msg); } while (0) 99 #else 100 /* Validate arguments and do nothing */ 101 static inline __printf(2, 3) 102 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 103 { 104 } 105 #endif 106 107 /* This is the per-socket lock. The spinlock provides a synchronization 108 * between user contexts and software interrupt processing, whereas the 109 * mini-semaphore synchronizes multiple users amongst themselves. 110 */ 111 typedef struct { 112 spinlock_t slock; 113 int owned; 114 wait_queue_head_t wq; 115 /* 116 * We express the mutex-alike socket_lock semantics 117 * to the lock validator by explicitly managing 118 * the slock as a lock variant (in addition to 119 * the slock itself): 120 */ 121 #ifdef CONFIG_DEBUG_LOCK_ALLOC 122 struct lockdep_map dep_map; 123 #endif 124 } socket_lock_t; 125 126 struct sock; 127 struct proto; 128 struct net; 129 130 typedef __u32 __bitwise __portpair; 131 typedef __u64 __bitwise __addrpair; 132 133 /** 134 * struct sock_common - minimal network layer representation of sockets 135 * @skc_daddr: Foreign IPv4 addr 136 * @skc_rcv_saddr: Bound local IPv4 addr 137 * @skc_hash: hash value used with various protocol lookup tables 138 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 139 * @skc_dport: placeholder for inet_dport/tw_dport 140 * @skc_num: placeholder for inet_num/tw_num 141 * @skc_family: network address family 142 * @skc_state: Connection state 143 * @skc_reuse: %SO_REUSEADDR setting 144 * @skc_reuseport: %SO_REUSEPORT setting 145 * @skc_bound_dev_if: bound device index if != 0 146 * @skc_bind_node: bind hash linkage for various protocol lookup tables 147 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 148 * @skc_prot: protocol handlers inside a network family 149 * @skc_net: reference to the network namespace of this socket 150 * @skc_node: main hash linkage for various protocol lookup tables 151 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 152 * @skc_tx_queue_mapping: tx queue number for this connection 153 * @skc_flags: place holder for sk_flags 154 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 155 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 156 * @skc_incoming_cpu: record/match cpu processing incoming packets 157 * @skc_refcnt: reference count 158 * 159 * This is the minimal network layer representation of sockets, the header 160 * for struct sock and struct inet_timewait_sock. 161 */ 162 struct sock_common { 163 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 164 * address on 64bit arches : cf INET_MATCH() 165 */ 166 union { 167 __addrpair skc_addrpair; 168 struct { 169 __be32 skc_daddr; 170 __be32 skc_rcv_saddr; 171 }; 172 }; 173 union { 174 unsigned int skc_hash; 175 __u16 skc_u16hashes[2]; 176 }; 177 /* skc_dport && skc_num must be grouped as well */ 178 union { 179 __portpair skc_portpair; 180 struct { 181 __be16 skc_dport; 182 __u16 skc_num; 183 }; 184 }; 185 186 unsigned short skc_family; 187 volatile unsigned char skc_state; 188 unsigned char skc_reuse:4; 189 unsigned char skc_reuseport:1; 190 unsigned char skc_ipv6only:1; 191 unsigned char skc_net_refcnt:1; 192 int skc_bound_dev_if; 193 union { 194 struct hlist_node skc_bind_node; 195 struct hlist_nulls_node skc_portaddr_node; 196 }; 197 struct proto *skc_prot; 198 possible_net_t skc_net; 199 200 #if IS_ENABLED(CONFIG_IPV6) 201 struct in6_addr skc_v6_daddr; 202 struct in6_addr skc_v6_rcv_saddr; 203 #endif 204 205 atomic64_t skc_cookie; 206 207 /* following fields are padding to force 208 * offset(struct sock, sk_refcnt) == 128 on 64bit arches 209 * assuming IPV6 is enabled. We use this padding differently 210 * for different kind of 'sockets' 211 */ 212 union { 213 unsigned long skc_flags; 214 struct sock *skc_listener; /* request_sock */ 215 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */ 216 }; 217 /* 218 * fields between dontcopy_begin/dontcopy_end 219 * are not copied in sock_copy() 220 */ 221 /* private: */ 222 int skc_dontcopy_begin[0]; 223 /* public: */ 224 union { 225 struct hlist_node skc_node; 226 struct hlist_nulls_node skc_nulls_node; 227 }; 228 int skc_tx_queue_mapping; 229 union { 230 int skc_incoming_cpu; 231 u32 skc_rcv_wnd; 232 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */ 233 }; 234 235 atomic_t skc_refcnt; 236 /* private: */ 237 int skc_dontcopy_end[0]; 238 union { 239 u32 skc_rxhash; 240 u32 skc_window_clamp; 241 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ 242 }; 243 /* public: */ 244 }; 245 246 struct cg_proto; 247 /** 248 * struct sock - network layer representation of sockets 249 * @__sk_common: shared layout with inet_timewait_sock 250 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 251 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 252 * @sk_lock: synchronizer 253 * @sk_rcvbuf: size of receive buffer in bytes 254 * @sk_wq: sock wait queue and async head 255 * @sk_rx_dst: receive input route used by early demux 256 * @sk_dst_cache: destination cache 257 * @sk_policy: flow policy 258 * @sk_receive_queue: incoming packets 259 * @sk_wmem_alloc: transmit queue bytes committed 260 * @sk_write_queue: Packet sending queue 261 * @sk_omem_alloc: "o" is "option" or "other" 262 * @sk_wmem_queued: persistent queue size 263 * @sk_forward_alloc: space allocated forward 264 * @sk_napi_id: id of the last napi context to receive data for sk 265 * @sk_ll_usec: usecs to busypoll when there is no data 266 * @sk_allocation: allocation mode 267 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler) 268 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE) 269 * @sk_sndbuf: size of send buffer in bytes 270 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets 271 * @sk_no_check_rx: allow zero checksum in RX packets 272 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 273 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 274 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 275 * @sk_gso_max_size: Maximum GSO segment size to build 276 * @sk_gso_max_segs: Maximum number of GSO segments 277 * @sk_lingertime: %SO_LINGER l_linger setting 278 * @sk_backlog: always used with the per-socket spinlock held 279 * @sk_callback_lock: used with the callbacks in the end of this struct 280 * @sk_error_queue: rarely used 281 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 282 * IPV6_ADDRFORM for instance) 283 * @sk_err: last error 284 * @sk_err_soft: errors that don't cause failure but are the cause of a 285 * persistent failure not just 'timed out' 286 * @sk_drops: raw/udp drops counter 287 * @sk_ack_backlog: current listen backlog 288 * @sk_max_ack_backlog: listen backlog set in listen() 289 * @sk_priority: %SO_PRIORITY setting 290 * @sk_cgrp_prioidx: socket group's priority map index 291 * @sk_type: socket type (%SOCK_STREAM, etc) 292 * @sk_protocol: which protocol this socket belongs in this network family 293 * @sk_peer_pid: &struct pid for this socket's peer 294 * @sk_peer_cred: %SO_PEERCRED setting 295 * @sk_rcvlowat: %SO_RCVLOWAT setting 296 * @sk_rcvtimeo: %SO_RCVTIMEO setting 297 * @sk_sndtimeo: %SO_SNDTIMEO setting 298 * @sk_txhash: computed flow hash for use on transmit 299 * @sk_filter: socket filtering instructions 300 * @sk_timer: sock cleanup timer 301 * @sk_stamp: time stamp of last packet received 302 * @sk_tsflags: SO_TIMESTAMPING socket options 303 * @sk_tskey: counter to disambiguate concurrent tstamp requests 304 * @sk_socket: Identd and reporting IO signals 305 * @sk_user_data: RPC layer private data 306 * @sk_frag: cached page frag 307 * @sk_peek_off: current peek_offset value 308 * @sk_send_head: front of stuff to transmit 309 * @sk_security: used by security modules 310 * @sk_mark: generic packet mark 311 * @sk_classid: this socket's cgroup classid 312 * @sk_cgrp: this socket's cgroup-specific proto data 313 * @sk_write_pending: a write to stream socket waits to start 314 * @sk_state_change: callback to indicate change in the state of the sock 315 * @sk_data_ready: callback to indicate there is data to be processed 316 * @sk_write_space: callback to indicate there is bf sending space available 317 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 318 * @sk_backlog_rcv: callback to process the backlog 319 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 320 */ 321 struct sock { 322 /* 323 * Now struct inet_timewait_sock also uses sock_common, so please just 324 * don't add nothing before this first member (__sk_common) --acme 325 */ 326 struct sock_common __sk_common; 327 #define sk_node __sk_common.skc_node 328 #define sk_nulls_node __sk_common.skc_nulls_node 329 #define sk_refcnt __sk_common.skc_refcnt 330 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 331 332 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 333 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 334 #define sk_hash __sk_common.skc_hash 335 #define sk_portpair __sk_common.skc_portpair 336 #define sk_num __sk_common.skc_num 337 #define sk_dport __sk_common.skc_dport 338 #define sk_addrpair __sk_common.skc_addrpair 339 #define sk_daddr __sk_common.skc_daddr 340 #define sk_rcv_saddr __sk_common.skc_rcv_saddr 341 #define sk_family __sk_common.skc_family 342 #define sk_state __sk_common.skc_state 343 #define sk_reuse __sk_common.skc_reuse 344 #define sk_reuseport __sk_common.skc_reuseport 345 #define sk_ipv6only __sk_common.skc_ipv6only 346 #define sk_net_refcnt __sk_common.skc_net_refcnt 347 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 348 #define sk_bind_node __sk_common.skc_bind_node 349 #define sk_prot __sk_common.skc_prot 350 #define sk_net __sk_common.skc_net 351 #define sk_v6_daddr __sk_common.skc_v6_daddr 352 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr 353 #define sk_cookie __sk_common.skc_cookie 354 #define sk_incoming_cpu __sk_common.skc_incoming_cpu 355 #define sk_flags __sk_common.skc_flags 356 #define sk_rxhash __sk_common.skc_rxhash 357 358 socket_lock_t sk_lock; 359 struct sk_buff_head sk_receive_queue; 360 /* 361 * The backlog queue is special, it is always used with 362 * the per-socket spinlock held and requires low latency 363 * access. Therefore we special case it's implementation. 364 * Note : rmem_alloc is in this structure to fill a hole 365 * on 64bit arches, not because its logically part of 366 * backlog. 367 */ 368 struct { 369 atomic_t rmem_alloc; 370 int len; 371 struct sk_buff *head; 372 struct sk_buff *tail; 373 } sk_backlog; 374 #define sk_rmem_alloc sk_backlog.rmem_alloc 375 int sk_forward_alloc; 376 377 __u32 sk_txhash; 378 #ifdef CONFIG_NET_RX_BUSY_POLL 379 unsigned int sk_napi_id; 380 unsigned int sk_ll_usec; 381 #endif 382 atomic_t sk_drops; 383 int sk_rcvbuf; 384 385 struct sk_filter __rcu *sk_filter; 386 union { 387 struct socket_wq __rcu *sk_wq; 388 struct socket_wq *sk_wq_raw; 389 }; 390 #ifdef CONFIG_XFRM 391 struct xfrm_policy *sk_policy[2]; 392 #endif 393 struct dst_entry *sk_rx_dst; 394 struct dst_entry __rcu *sk_dst_cache; 395 /* Note: 32bit hole on 64bit arches */ 396 atomic_t sk_wmem_alloc; 397 atomic_t sk_omem_alloc; 398 int sk_sndbuf; 399 struct sk_buff_head sk_write_queue; 400 kmemcheck_bitfield_begin(flags); 401 unsigned int sk_shutdown : 2, 402 sk_no_check_tx : 1, 403 sk_no_check_rx : 1, 404 sk_userlocks : 4, 405 sk_protocol : 8, 406 sk_type : 16; 407 kmemcheck_bitfield_end(flags); 408 int sk_wmem_queued; 409 gfp_t sk_allocation; 410 u32 sk_pacing_rate; /* bytes per second */ 411 u32 sk_max_pacing_rate; 412 netdev_features_t sk_route_caps; 413 netdev_features_t sk_route_nocaps; 414 int sk_gso_type; 415 unsigned int sk_gso_max_size; 416 u16 sk_gso_max_segs; 417 int sk_rcvlowat; 418 unsigned long sk_lingertime; 419 struct sk_buff_head sk_error_queue; 420 struct proto *sk_prot_creator; 421 rwlock_t sk_callback_lock; 422 int sk_err, 423 sk_err_soft; 424 u32 sk_ack_backlog; 425 u32 sk_max_ack_backlog; 426 __u32 sk_priority; 427 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO) 428 __u32 sk_cgrp_prioidx; 429 #endif 430 struct pid *sk_peer_pid; 431 const struct cred *sk_peer_cred; 432 long sk_rcvtimeo; 433 long sk_sndtimeo; 434 struct timer_list sk_timer; 435 ktime_t sk_stamp; 436 u16 sk_tsflags; 437 u32 sk_tskey; 438 struct socket *sk_socket; 439 void *sk_user_data; 440 struct page_frag sk_frag; 441 struct sk_buff *sk_send_head; 442 __s32 sk_peek_off; 443 int sk_write_pending; 444 #ifdef CONFIG_SECURITY 445 void *sk_security; 446 #endif 447 __u32 sk_mark; 448 #ifdef CONFIG_CGROUP_NET_CLASSID 449 u32 sk_classid; 450 #endif 451 struct cg_proto *sk_cgrp; 452 void (*sk_state_change)(struct sock *sk); 453 void (*sk_data_ready)(struct sock *sk); 454 void (*sk_write_space)(struct sock *sk); 455 void (*sk_error_report)(struct sock *sk); 456 int (*sk_backlog_rcv)(struct sock *sk, 457 struct sk_buff *skb); 458 void (*sk_destruct)(struct sock *sk); 459 }; 460 461 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) 462 463 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) 464 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) 465 466 /* 467 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 468 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 469 * on a socket means that the socket will reuse everybody else's port 470 * without looking at the other's sk_reuse value. 471 */ 472 473 #define SK_NO_REUSE 0 474 #define SK_CAN_REUSE 1 475 #define SK_FORCE_REUSE 2 476 477 static inline int sk_peek_offset(struct sock *sk, int flags) 478 { 479 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0)) 480 return sk->sk_peek_off; 481 else 482 return 0; 483 } 484 485 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 486 { 487 if (sk->sk_peek_off >= 0) { 488 if (sk->sk_peek_off >= val) 489 sk->sk_peek_off -= val; 490 else 491 sk->sk_peek_off = 0; 492 } 493 } 494 495 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 496 { 497 if (sk->sk_peek_off >= 0) 498 sk->sk_peek_off += val; 499 } 500 501 /* 502 * Hashed lists helper routines 503 */ 504 static inline struct sock *sk_entry(const struct hlist_node *node) 505 { 506 return hlist_entry(node, struct sock, sk_node); 507 } 508 509 static inline struct sock *__sk_head(const struct hlist_head *head) 510 { 511 return hlist_entry(head->first, struct sock, sk_node); 512 } 513 514 static inline struct sock *sk_head(const struct hlist_head *head) 515 { 516 return hlist_empty(head) ? NULL : __sk_head(head); 517 } 518 519 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 520 { 521 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 522 } 523 524 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 525 { 526 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 527 } 528 529 static inline struct sock *sk_next(const struct sock *sk) 530 { 531 return sk->sk_node.next ? 532 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 533 } 534 535 static inline struct sock *sk_nulls_next(const struct sock *sk) 536 { 537 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 538 hlist_nulls_entry(sk->sk_nulls_node.next, 539 struct sock, sk_nulls_node) : 540 NULL; 541 } 542 543 static inline bool sk_unhashed(const struct sock *sk) 544 { 545 return hlist_unhashed(&sk->sk_node); 546 } 547 548 static inline bool sk_hashed(const struct sock *sk) 549 { 550 return !sk_unhashed(sk); 551 } 552 553 static inline void sk_node_init(struct hlist_node *node) 554 { 555 node->pprev = NULL; 556 } 557 558 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 559 { 560 node->pprev = NULL; 561 } 562 563 static inline void __sk_del_node(struct sock *sk) 564 { 565 __hlist_del(&sk->sk_node); 566 } 567 568 /* NB: equivalent to hlist_del_init_rcu */ 569 static inline bool __sk_del_node_init(struct sock *sk) 570 { 571 if (sk_hashed(sk)) { 572 __sk_del_node(sk); 573 sk_node_init(&sk->sk_node); 574 return true; 575 } 576 return false; 577 } 578 579 /* Grab socket reference count. This operation is valid only 580 when sk is ALREADY grabbed f.e. it is found in hash table 581 or a list and the lookup is made under lock preventing hash table 582 modifications. 583 */ 584 585 static inline void sock_hold(struct sock *sk) 586 { 587 atomic_inc(&sk->sk_refcnt); 588 } 589 590 /* Ungrab socket in the context, which assumes that socket refcnt 591 cannot hit zero, f.e. it is true in context of any socketcall. 592 */ 593 static inline void __sock_put(struct sock *sk) 594 { 595 atomic_dec(&sk->sk_refcnt); 596 } 597 598 static inline bool sk_del_node_init(struct sock *sk) 599 { 600 bool rc = __sk_del_node_init(sk); 601 602 if (rc) { 603 /* paranoid for a while -acme */ 604 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 605 __sock_put(sk); 606 } 607 return rc; 608 } 609 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 610 611 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 612 { 613 if (sk_hashed(sk)) { 614 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 615 return true; 616 } 617 return false; 618 } 619 620 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 621 { 622 bool rc = __sk_nulls_del_node_init_rcu(sk); 623 624 if (rc) { 625 /* paranoid for a while -acme */ 626 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 627 __sock_put(sk); 628 } 629 return rc; 630 } 631 632 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 633 { 634 hlist_add_head(&sk->sk_node, list); 635 } 636 637 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 638 { 639 sock_hold(sk); 640 __sk_add_node(sk, list); 641 } 642 643 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 644 { 645 sock_hold(sk); 646 hlist_add_head_rcu(&sk->sk_node, list); 647 } 648 649 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 650 { 651 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 652 } 653 654 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 655 { 656 sock_hold(sk); 657 __sk_nulls_add_node_rcu(sk, list); 658 } 659 660 static inline void __sk_del_bind_node(struct sock *sk) 661 { 662 __hlist_del(&sk->sk_bind_node); 663 } 664 665 static inline void sk_add_bind_node(struct sock *sk, 666 struct hlist_head *list) 667 { 668 hlist_add_head(&sk->sk_bind_node, list); 669 } 670 671 #define sk_for_each(__sk, list) \ 672 hlist_for_each_entry(__sk, list, sk_node) 673 #define sk_for_each_rcu(__sk, list) \ 674 hlist_for_each_entry_rcu(__sk, list, sk_node) 675 #define sk_nulls_for_each(__sk, node, list) \ 676 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 677 #define sk_nulls_for_each_rcu(__sk, node, list) \ 678 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 679 #define sk_for_each_from(__sk) \ 680 hlist_for_each_entry_from(__sk, sk_node) 681 #define sk_nulls_for_each_from(__sk, node) \ 682 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 683 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 684 #define sk_for_each_safe(__sk, tmp, list) \ 685 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 686 #define sk_for_each_bound(__sk, list) \ 687 hlist_for_each_entry(__sk, list, sk_bind_node) 688 689 /** 690 * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset 691 * @tpos: the type * to use as a loop cursor. 692 * @pos: the &struct hlist_node to use as a loop cursor. 693 * @head: the head for your list. 694 * @offset: offset of hlist_node within the struct. 695 * 696 */ 697 #define sk_nulls_for_each_entry_offset(tpos, pos, head, offset) \ 698 for (pos = (head)->first; \ 699 (!is_a_nulls(pos)) && \ 700 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 701 pos = pos->next) 702 703 static inline struct user_namespace *sk_user_ns(struct sock *sk) 704 { 705 /* Careful only use this in a context where these parameters 706 * can not change and must all be valid, such as recvmsg from 707 * userspace. 708 */ 709 return sk->sk_socket->file->f_cred->user_ns; 710 } 711 712 /* Sock flags */ 713 enum sock_flags { 714 SOCK_DEAD, 715 SOCK_DONE, 716 SOCK_URGINLINE, 717 SOCK_KEEPOPEN, 718 SOCK_LINGER, 719 SOCK_DESTROY, 720 SOCK_BROADCAST, 721 SOCK_TIMESTAMP, 722 SOCK_ZAPPED, 723 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 724 SOCK_DBG, /* %SO_DEBUG setting */ 725 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 726 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 727 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 728 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 729 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 730 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 731 SOCK_FASYNC, /* fasync() active */ 732 SOCK_RXQ_OVFL, 733 SOCK_ZEROCOPY, /* buffers from userspace */ 734 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 735 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 736 * Will use last 4 bytes of packet sent from 737 * user-space instead. 738 */ 739 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 740 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 741 }; 742 743 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 744 { 745 nsk->sk_flags = osk->sk_flags; 746 } 747 748 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 749 { 750 __set_bit(flag, &sk->sk_flags); 751 } 752 753 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 754 { 755 __clear_bit(flag, &sk->sk_flags); 756 } 757 758 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 759 { 760 return test_bit(flag, &sk->sk_flags); 761 } 762 763 #ifdef CONFIG_NET 764 extern struct static_key memalloc_socks; 765 static inline int sk_memalloc_socks(void) 766 { 767 return static_key_false(&memalloc_socks); 768 } 769 #else 770 771 static inline int sk_memalloc_socks(void) 772 { 773 return 0; 774 } 775 776 #endif 777 778 static inline gfp_t sk_gfp_atomic(const struct sock *sk, gfp_t gfp_mask) 779 { 780 return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC); 781 } 782 783 static inline void sk_acceptq_removed(struct sock *sk) 784 { 785 sk->sk_ack_backlog--; 786 } 787 788 static inline void sk_acceptq_added(struct sock *sk) 789 { 790 sk->sk_ack_backlog++; 791 } 792 793 static inline bool sk_acceptq_is_full(const struct sock *sk) 794 { 795 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 796 } 797 798 /* 799 * Compute minimal free write space needed to queue new packets. 800 */ 801 static inline int sk_stream_min_wspace(const struct sock *sk) 802 { 803 return sk->sk_wmem_queued >> 1; 804 } 805 806 static inline int sk_stream_wspace(const struct sock *sk) 807 { 808 return sk->sk_sndbuf - sk->sk_wmem_queued; 809 } 810 811 void sk_stream_write_space(struct sock *sk); 812 813 /* OOB backlog add */ 814 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 815 { 816 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 817 skb_dst_force(skb); 818 819 if (!sk->sk_backlog.tail) 820 sk->sk_backlog.head = skb; 821 else 822 sk->sk_backlog.tail->next = skb; 823 824 sk->sk_backlog.tail = skb; 825 skb->next = NULL; 826 } 827 828 /* 829 * Take into account size of receive queue and backlog queue 830 * Do not take into account this skb truesize, 831 * to allow even a single big packet to come. 832 */ 833 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 834 { 835 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 836 837 return qsize > limit; 838 } 839 840 /* The per-socket spinlock must be held here. */ 841 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 842 unsigned int limit) 843 { 844 if (sk_rcvqueues_full(sk, limit)) 845 return -ENOBUFS; 846 847 /* 848 * If the skb was allocated from pfmemalloc reserves, only 849 * allow SOCK_MEMALLOC sockets to use it as this socket is 850 * helping free memory 851 */ 852 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 853 return -ENOMEM; 854 855 __sk_add_backlog(sk, skb); 856 sk->sk_backlog.len += skb->truesize; 857 return 0; 858 } 859 860 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 861 862 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 863 { 864 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 865 return __sk_backlog_rcv(sk, skb); 866 867 return sk->sk_backlog_rcv(sk, skb); 868 } 869 870 static inline void sk_incoming_cpu_update(struct sock *sk) 871 { 872 sk->sk_incoming_cpu = raw_smp_processor_id(); 873 } 874 875 static inline void sock_rps_record_flow_hash(__u32 hash) 876 { 877 #ifdef CONFIG_RPS 878 struct rps_sock_flow_table *sock_flow_table; 879 880 rcu_read_lock(); 881 sock_flow_table = rcu_dereference(rps_sock_flow_table); 882 rps_record_sock_flow(sock_flow_table, hash); 883 rcu_read_unlock(); 884 #endif 885 } 886 887 static inline void sock_rps_record_flow(const struct sock *sk) 888 { 889 #ifdef CONFIG_RPS 890 sock_rps_record_flow_hash(sk->sk_rxhash); 891 #endif 892 } 893 894 static inline void sock_rps_save_rxhash(struct sock *sk, 895 const struct sk_buff *skb) 896 { 897 #ifdef CONFIG_RPS 898 if (unlikely(sk->sk_rxhash != skb->hash)) 899 sk->sk_rxhash = skb->hash; 900 #endif 901 } 902 903 static inline void sock_rps_reset_rxhash(struct sock *sk) 904 { 905 #ifdef CONFIG_RPS 906 sk->sk_rxhash = 0; 907 #endif 908 } 909 910 #define sk_wait_event(__sk, __timeo, __condition) \ 911 ({ int __rc; \ 912 release_sock(__sk); \ 913 __rc = __condition; \ 914 if (!__rc) { \ 915 *(__timeo) = schedule_timeout(*(__timeo)); \ 916 } \ 917 sched_annotate_sleep(); \ 918 lock_sock(__sk); \ 919 __rc = __condition; \ 920 __rc; \ 921 }) 922 923 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 924 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 925 void sk_stream_wait_close(struct sock *sk, long timeo_p); 926 int sk_stream_error(struct sock *sk, int flags, int err); 927 void sk_stream_kill_queues(struct sock *sk); 928 void sk_set_memalloc(struct sock *sk); 929 void sk_clear_memalloc(struct sock *sk); 930 931 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 932 933 struct request_sock_ops; 934 struct timewait_sock_ops; 935 struct inet_hashinfo; 936 struct raw_hashinfo; 937 struct module; 938 939 /* 940 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes 941 * un-modified. Special care is taken when initializing object to zero. 942 */ 943 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 944 { 945 if (offsetof(struct sock, sk_node.next) != 0) 946 memset(sk, 0, offsetof(struct sock, sk_node.next)); 947 memset(&sk->sk_node.pprev, 0, 948 size - offsetof(struct sock, sk_node.pprev)); 949 } 950 951 /* Networking protocol blocks we attach to sockets. 952 * socket layer -> transport layer interface 953 */ 954 struct proto { 955 void (*close)(struct sock *sk, 956 long timeout); 957 int (*connect)(struct sock *sk, 958 struct sockaddr *uaddr, 959 int addr_len); 960 int (*disconnect)(struct sock *sk, int flags); 961 962 struct sock * (*accept)(struct sock *sk, int flags, int *err); 963 964 int (*ioctl)(struct sock *sk, int cmd, 965 unsigned long arg); 966 int (*init)(struct sock *sk); 967 void (*destroy)(struct sock *sk); 968 void (*shutdown)(struct sock *sk, int how); 969 int (*setsockopt)(struct sock *sk, int level, 970 int optname, char __user *optval, 971 unsigned int optlen); 972 int (*getsockopt)(struct sock *sk, int level, 973 int optname, char __user *optval, 974 int __user *option); 975 #ifdef CONFIG_COMPAT 976 int (*compat_setsockopt)(struct sock *sk, 977 int level, 978 int optname, char __user *optval, 979 unsigned int optlen); 980 int (*compat_getsockopt)(struct sock *sk, 981 int level, 982 int optname, char __user *optval, 983 int __user *option); 984 int (*compat_ioctl)(struct sock *sk, 985 unsigned int cmd, unsigned long arg); 986 #endif 987 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 988 size_t len); 989 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 990 size_t len, int noblock, int flags, 991 int *addr_len); 992 int (*sendpage)(struct sock *sk, struct page *page, 993 int offset, size_t size, int flags); 994 int (*bind)(struct sock *sk, 995 struct sockaddr *uaddr, int addr_len); 996 997 int (*backlog_rcv) (struct sock *sk, 998 struct sk_buff *skb); 999 1000 void (*release_cb)(struct sock *sk); 1001 1002 /* Keeping track of sk's, looking them up, and port selection methods. */ 1003 void (*hash)(struct sock *sk); 1004 void (*unhash)(struct sock *sk); 1005 void (*rehash)(struct sock *sk); 1006 int (*get_port)(struct sock *sk, unsigned short snum); 1007 void (*clear_sk)(struct sock *sk, int size); 1008 1009 /* Keeping track of sockets in use */ 1010 #ifdef CONFIG_PROC_FS 1011 unsigned int inuse_idx; 1012 #endif 1013 1014 bool (*stream_memory_free)(const struct sock *sk); 1015 /* Memory pressure */ 1016 void (*enter_memory_pressure)(struct sock *sk); 1017 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1018 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1019 /* 1020 * Pressure flag: try to collapse. 1021 * Technical note: it is used by multiple contexts non atomically. 1022 * All the __sk_mem_schedule() is of this nature: accounting 1023 * is strict, actions are advisory and have some latency. 1024 */ 1025 int *memory_pressure; 1026 long *sysctl_mem; 1027 int *sysctl_wmem; 1028 int *sysctl_rmem; 1029 int max_header; 1030 bool no_autobind; 1031 1032 struct kmem_cache *slab; 1033 unsigned int obj_size; 1034 int slab_flags; 1035 1036 struct percpu_counter *orphan_count; 1037 1038 struct request_sock_ops *rsk_prot; 1039 struct timewait_sock_ops *twsk_prot; 1040 1041 union { 1042 struct inet_hashinfo *hashinfo; 1043 struct udp_table *udp_table; 1044 struct raw_hashinfo *raw_hash; 1045 } h; 1046 1047 struct module *owner; 1048 1049 char name[32]; 1050 1051 struct list_head node; 1052 #ifdef SOCK_REFCNT_DEBUG 1053 atomic_t socks; 1054 #endif 1055 #ifdef CONFIG_MEMCG_KMEM 1056 /* 1057 * cgroup specific init/deinit functions. Called once for all 1058 * protocols that implement it, from cgroups populate function. 1059 * This function has to setup any files the protocol want to 1060 * appear in the kmem cgroup filesystem. 1061 */ 1062 int (*init_cgroup)(struct mem_cgroup *memcg, 1063 struct cgroup_subsys *ss); 1064 void (*destroy_cgroup)(struct mem_cgroup *memcg); 1065 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg); 1066 #endif 1067 }; 1068 1069 int proto_register(struct proto *prot, int alloc_slab); 1070 void proto_unregister(struct proto *prot); 1071 1072 #ifdef SOCK_REFCNT_DEBUG 1073 static inline void sk_refcnt_debug_inc(struct sock *sk) 1074 { 1075 atomic_inc(&sk->sk_prot->socks); 1076 } 1077 1078 static inline void sk_refcnt_debug_dec(struct sock *sk) 1079 { 1080 atomic_dec(&sk->sk_prot->socks); 1081 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1082 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1083 } 1084 1085 static inline void sk_refcnt_debug_release(const struct sock *sk) 1086 { 1087 if (atomic_read(&sk->sk_refcnt) != 1) 1088 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1089 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 1090 } 1091 #else /* SOCK_REFCNT_DEBUG */ 1092 #define sk_refcnt_debug_inc(sk) do { } while (0) 1093 #define sk_refcnt_debug_dec(sk) do { } while (0) 1094 #define sk_refcnt_debug_release(sk) do { } while (0) 1095 #endif /* SOCK_REFCNT_DEBUG */ 1096 1097 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET) 1098 extern struct static_key memcg_socket_limit_enabled; 1099 static inline struct cg_proto *parent_cg_proto(struct proto *proto, 1100 struct cg_proto *cg_proto) 1101 { 1102 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg)); 1103 } 1104 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled) 1105 #else 1106 #define mem_cgroup_sockets_enabled 0 1107 static inline struct cg_proto *parent_cg_proto(struct proto *proto, 1108 struct cg_proto *cg_proto) 1109 { 1110 return NULL; 1111 } 1112 #endif 1113 1114 static inline bool sk_stream_memory_free(const struct sock *sk) 1115 { 1116 if (sk->sk_wmem_queued >= sk->sk_sndbuf) 1117 return false; 1118 1119 return sk->sk_prot->stream_memory_free ? 1120 sk->sk_prot->stream_memory_free(sk) : true; 1121 } 1122 1123 static inline bool sk_stream_is_writeable(const struct sock *sk) 1124 { 1125 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1126 sk_stream_memory_free(sk); 1127 } 1128 1129 1130 static inline bool sk_has_memory_pressure(const struct sock *sk) 1131 { 1132 return sk->sk_prot->memory_pressure != NULL; 1133 } 1134 1135 static inline bool sk_under_memory_pressure(const struct sock *sk) 1136 { 1137 if (!sk->sk_prot->memory_pressure) 1138 return false; 1139 1140 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1141 return !!sk->sk_cgrp->memory_pressure; 1142 1143 return !!*sk->sk_prot->memory_pressure; 1144 } 1145 1146 static inline void sk_leave_memory_pressure(struct sock *sk) 1147 { 1148 int *memory_pressure = sk->sk_prot->memory_pressure; 1149 1150 if (!memory_pressure) 1151 return; 1152 1153 if (*memory_pressure) 1154 *memory_pressure = 0; 1155 1156 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1157 struct cg_proto *cg_proto = sk->sk_cgrp; 1158 struct proto *prot = sk->sk_prot; 1159 1160 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1161 cg_proto->memory_pressure = 0; 1162 } 1163 1164 } 1165 1166 static inline void sk_enter_memory_pressure(struct sock *sk) 1167 { 1168 if (!sk->sk_prot->enter_memory_pressure) 1169 return; 1170 1171 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1172 struct cg_proto *cg_proto = sk->sk_cgrp; 1173 struct proto *prot = sk->sk_prot; 1174 1175 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1176 cg_proto->memory_pressure = 1; 1177 } 1178 1179 sk->sk_prot->enter_memory_pressure(sk); 1180 } 1181 1182 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1183 { 1184 long *prot = sk->sk_prot->sysctl_mem; 1185 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1186 prot = sk->sk_cgrp->sysctl_mem; 1187 return prot[index]; 1188 } 1189 1190 static inline void memcg_memory_allocated_add(struct cg_proto *prot, 1191 unsigned long amt, 1192 int *parent_status) 1193 { 1194 page_counter_charge(&prot->memory_allocated, amt); 1195 1196 if (page_counter_read(&prot->memory_allocated) > 1197 prot->memory_allocated.limit) 1198 *parent_status = OVER_LIMIT; 1199 } 1200 1201 static inline void memcg_memory_allocated_sub(struct cg_proto *prot, 1202 unsigned long amt) 1203 { 1204 page_counter_uncharge(&prot->memory_allocated, amt); 1205 } 1206 1207 static inline long 1208 sk_memory_allocated(const struct sock *sk) 1209 { 1210 struct proto *prot = sk->sk_prot; 1211 1212 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1213 return page_counter_read(&sk->sk_cgrp->memory_allocated); 1214 1215 return atomic_long_read(prot->memory_allocated); 1216 } 1217 1218 static inline long 1219 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status) 1220 { 1221 struct proto *prot = sk->sk_prot; 1222 1223 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1224 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status); 1225 /* update the root cgroup regardless */ 1226 atomic_long_add_return(amt, prot->memory_allocated); 1227 return page_counter_read(&sk->sk_cgrp->memory_allocated); 1228 } 1229 1230 return atomic_long_add_return(amt, prot->memory_allocated); 1231 } 1232 1233 static inline void 1234 sk_memory_allocated_sub(struct sock *sk, int amt) 1235 { 1236 struct proto *prot = sk->sk_prot; 1237 1238 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1239 memcg_memory_allocated_sub(sk->sk_cgrp, amt); 1240 1241 atomic_long_sub(amt, prot->memory_allocated); 1242 } 1243 1244 static inline void sk_sockets_allocated_dec(struct sock *sk) 1245 { 1246 struct proto *prot = sk->sk_prot; 1247 1248 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1249 struct cg_proto *cg_proto = sk->sk_cgrp; 1250 1251 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1252 percpu_counter_dec(&cg_proto->sockets_allocated); 1253 } 1254 1255 percpu_counter_dec(prot->sockets_allocated); 1256 } 1257 1258 static inline void sk_sockets_allocated_inc(struct sock *sk) 1259 { 1260 struct proto *prot = sk->sk_prot; 1261 1262 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { 1263 struct cg_proto *cg_proto = sk->sk_cgrp; 1264 1265 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) 1266 percpu_counter_inc(&cg_proto->sockets_allocated); 1267 } 1268 1269 percpu_counter_inc(prot->sockets_allocated); 1270 } 1271 1272 static inline int 1273 sk_sockets_allocated_read_positive(struct sock *sk) 1274 { 1275 struct proto *prot = sk->sk_prot; 1276 1277 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) 1278 return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated); 1279 1280 return percpu_counter_read_positive(prot->sockets_allocated); 1281 } 1282 1283 static inline int 1284 proto_sockets_allocated_sum_positive(struct proto *prot) 1285 { 1286 return percpu_counter_sum_positive(prot->sockets_allocated); 1287 } 1288 1289 static inline long 1290 proto_memory_allocated(struct proto *prot) 1291 { 1292 return atomic_long_read(prot->memory_allocated); 1293 } 1294 1295 static inline bool 1296 proto_memory_pressure(struct proto *prot) 1297 { 1298 if (!prot->memory_pressure) 1299 return false; 1300 return !!*prot->memory_pressure; 1301 } 1302 1303 1304 #ifdef CONFIG_PROC_FS 1305 /* Called with local bh disabled */ 1306 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1307 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1308 #else 1309 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1310 int inc) 1311 { 1312 } 1313 #endif 1314 1315 1316 /* With per-bucket locks this operation is not-atomic, so that 1317 * this version is not worse. 1318 */ 1319 static inline void __sk_prot_rehash(struct sock *sk) 1320 { 1321 sk->sk_prot->unhash(sk); 1322 sk->sk_prot->hash(sk); 1323 } 1324 1325 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 1326 1327 /* About 10 seconds */ 1328 #define SOCK_DESTROY_TIME (10*HZ) 1329 1330 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1331 #define PROT_SOCK 1024 1332 1333 #define SHUTDOWN_MASK 3 1334 #define RCV_SHUTDOWN 1 1335 #define SEND_SHUTDOWN 2 1336 1337 #define SOCK_SNDBUF_LOCK 1 1338 #define SOCK_RCVBUF_LOCK 2 1339 #define SOCK_BINDADDR_LOCK 4 1340 #define SOCK_BINDPORT_LOCK 8 1341 1342 struct socket_alloc { 1343 struct socket socket; 1344 struct inode vfs_inode; 1345 }; 1346 1347 static inline struct socket *SOCKET_I(struct inode *inode) 1348 { 1349 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1350 } 1351 1352 static inline struct inode *SOCK_INODE(struct socket *socket) 1353 { 1354 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1355 } 1356 1357 /* 1358 * Functions for memory accounting 1359 */ 1360 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1361 void __sk_mem_reclaim(struct sock *sk, int amount); 1362 1363 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 1364 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1365 #define SK_MEM_SEND 0 1366 #define SK_MEM_RECV 1 1367 1368 static inline int sk_mem_pages(int amt) 1369 { 1370 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1371 } 1372 1373 static inline bool sk_has_account(struct sock *sk) 1374 { 1375 /* return true if protocol supports memory accounting */ 1376 return !!sk->sk_prot->memory_allocated; 1377 } 1378 1379 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1380 { 1381 if (!sk_has_account(sk)) 1382 return true; 1383 return size <= sk->sk_forward_alloc || 1384 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1385 } 1386 1387 static inline bool 1388 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1389 { 1390 if (!sk_has_account(sk)) 1391 return true; 1392 return size<= sk->sk_forward_alloc || 1393 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1394 skb_pfmemalloc(skb); 1395 } 1396 1397 static inline void sk_mem_reclaim(struct sock *sk) 1398 { 1399 if (!sk_has_account(sk)) 1400 return; 1401 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1402 __sk_mem_reclaim(sk, sk->sk_forward_alloc); 1403 } 1404 1405 static inline void sk_mem_reclaim_partial(struct sock *sk) 1406 { 1407 if (!sk_has_account(sk)) 1408 return; 1409 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1410 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); 1411 } 1412 1413 static inline void sk_mem_charge(struct sock *sk, int size) 1414 { 1415 if (!sk_has_account(sk)) 1416 return; 1417 sk->sk_forward_alloc -= size; 1418 } 1419 1420 static inline void sk_mem_uncharge(struct sock *sk, int size) 1421 { 1422 if (!sk_has_account(sk)) 1423 return; 1424 sk->sk_forward_alloc += size; 1425 } 1426 1427 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1428 { 1429 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1430 sk->sk_wmem_queued -= skb->truesize; 1431 sk_mem_uncharge(sk, skb->truesize); 1432 __kfree_skb(skb); 1433 } 1434 1435 /* Used by processes to "lock" a socket state, so that 1436 * interrupts and bottom half handlers won't change it 1437 * from under us. It essentially blocks any incoming 1438 * packets, so that we won't get any new data or any 1439 * packets that change the state of the socket. 1440 * 1441 * While locked, BH processing will add new packets to 1442 * the backlog queue. This queue is processed by the 1443 * owner of the socket lock right before it is released. 1444 * 1445 * Since ~2.3.5 it is also exclusive sleep lock serializing 1446 * accesses from user process context. 1447 */ 1448 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned) 1449 1450 static inline void sock_release_ownership(struct sock *sk) 1451 { 1452 sk->sk_lock.owned = 0; 1453 } 1454 1455 /* 1456 * Macro so as to not evaluate some arguments when 1457 * lockdep is not enabled. 1458 * 1459 * Mark both the sk_lock and the sk_lock.slock as a 1460 * per-address-family lock class. 1461 */ 1462 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1463 do { \ 1464 sk->sk_lock.owned = 0; \ 1465 init_waitqueue_head(&sk->sk_lock.wq); \ 1466 spin_lock_init(&(sk)->sk_lock.slock); \ 1467 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1468 sizeof((sk)->sk_lock)); \ 1469 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1470 (skey), (sname)); \ 1471 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1472 } while (0) 1473 1474 void lock_sock_nested(struct sock *sk, int subclass); 1475 1476 static inline void lock_sock(struct sock *sk) 1477 { 1478 lock_sock_nested(sk, 0); 1479 } 1480 1481 void release_sock(struct sock *sk); 1482 1483 /* BH context may only use the following locking interface. */ 1484 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1485 #define bh_lock_sock_nested(__sk) \ 1486 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1487 SINGLE_DEPTH_NESTING) 1488 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1489 1490 bool lock_sock_fast(struct sock *sk); 1491 /** 1492 * unlock_sock_fast - complement of lock_sock_fast 1493 * @sk: socket 1494 * @slow: slow mode 1495 * 1496 * fast unlock socket for user context. 1497 * If slow mode is on, we call regular release_sock() 1498 */ 1499 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1500 { 1501 if (slow) 1502 release_sock(sk); 1503 else 1504 spin_unlock_bh(&sk->sk_lock.slock); 1505 } 1506 1507 1508 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1509 struct proto *prot, int kern); 1510 void sk_free(struct sock *sk); 1511 void sk_destruct(struct sock *sk); 1512 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1513 1514 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1515 gfp_t priority); 1516 void sock_wfree(struct sk_buff *skb); 1517 void skb_orphan_partial(struct sk_buff *skb); 1518 void sock_rfree(struct sk_buff *skb); 1519 void sock_efree(struct sk_buff *skb); 1520 #ifdef CONFIG_INET 1521 void sock_edemux(struct sk_buff *skb); 1522 #else 1523 #define sock_edemux(skb) sock_efree(skb) 1524 #endif 1525 1526 int sock_setsockopt(struct socket *sock, int level, int op, 1527 char __user *optval, unsigned int optlen); 1528 1529 int sock_getsockopt(struct socket *sock, int level, int op, 1530 char __user *optval, int __user *optlen); 1531 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1532 int noblock, int *errcode); 1533 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1534 unsigned long data_len, int noblock, 1535 int *errcode, int max_page_order); 1536 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1537 void sock_kfree_s(struct sock *sk, void *mem, int size); 1538 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1539 void sk_send_sigurg(struct sock *sk); 1540 1541 struct sockcm_cookie { 1542 u32 mark; 1543 }; 1544 1545 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1546 struct sockcm_cookie *sockc); 1547 1548 /* 1549 * Functions to fill in entries in struct proto_ops when a protocol 1550 * does not implement a particular function. 1551 */ 1552 int sock_no_bind(struct socket *, struct sockaddr *, int); 1553 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1554 int sock_no_socketpair(struct socket *, struct socket *); 1555 int sock_no_accept(struct socket *, struct socket *, int); 1556 int sock_no_getname(struct socket *, struct sockaddr *, int *, int); 1557 unsigned int sock_no_poll(struct file *, struct socket *, 1558 struct poll_table_struct *); 1559 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1560 int sock_no_listen(struct socket *, int); 1561 int sock_no_shutdown(struct socket *, int); 1562 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *); 1563 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int); 1564 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1565 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1566 int sock_no_mmap(struct file *file, struct socket *sock, 1567 struct vm_area_struct *vma); 1568 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1569 size_t size, int flags); 1570 1571 /* 1572 * Functions to fill in entries in struct proto_ops when a protocol 1573 * uses the inet style. 1574 */ 1575 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1576 char __user *optval, int __user *optlen); 1577 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1578 int flags); 1579 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1580 char __user *optval, unsigned int optlen); 1581 int compat_sock_common_getsockopt(struct socket *sock, int level, 1582 int optname, char __user *optval, int __user *optlen); 1583 int compat_sock_common_setsockopt(struct socket *sock, int level, 1584 int optname, char __user *optval, unsigned int optlen); 1585 1586 void sk_common_release(struct sock *sk); 1587 1588 /* 1589 * Default socket callbacks and setup code 1590 */ 1591 1592 /* Initialise core socket variables */ 1593 void sock_init_data(struct socket *sock, struct sock *sk); 1594 1595 /* 1596 * Socket reference counting postulates. 1597 * 1598 * * Each user of socket SHOULD hold a reference count. 1599 * * Each access point to socket (an hash table bucket, reference from a list, 1600 * running timer, skb in flight MUST hold a reference count. 1601 * * When reference count hits 0, it means it will never increase back. 1602 * * When reference count hits 0, it means that no references from 1603 * outside exist to this socket and current process on current CPU 1604 * is last user and may/should destroy this socket. 1605 * * sk_free is called from any context: process, BH, IRQ. When 1606 * it is called, socket has no references from outside -> sk_free 1607 * may release descendant resources allocated by the socket, but 1608 * to the time when it is called, socket is NOT referenced by any 1609 * hash tables, lists etc. 1610 * * Packets, delivered from outside (from network or from another process) 1611 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1612 * when they sit in queue. Otherwise, packets will leak to hole, when 1613 * socket is looked up by one cpu and unhasing is made by another CPU. 1614 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1615 * (leak to backlog). Packet socket does all the processing inside 1616 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1617 * use separate SMP lock, so that they are prone too. 1618 */ 1619 1620 /* Ungrab socket and destroy it, if it was the last reference. */ 1621 static inline void sock_put(struct sock *sk) 1622 { 1623 if (atomic_dec_and_test(&sk->sk_refcnt)) 1624 sk_free(sk); 1625 } 1626 /* Generic version of sock_put(), dealing with all sockets 1627 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1628 */ 1629 void sock_gen_put(struct sock *sk); 1630 1631 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested); 1632 1633 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1634 { 1635 sk->sk_tx_queue_mapping = tx_queue; 1636 } 1637 1638 static inline void sk_tx_queue_clear(struct sock *sk) 1639 { 1640 sk->sk_tx_queue_mapping = -1; 1641 } 1642 1643 static inline int sk_tx_queue_get(const struct sock *sk) 1644 { 1645 return sk ? sk->sk_tx_queue_mapping : -1; 1646 } 1647 1648 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1649 { 1650 sk_tx_queue_clear(sk); 1651 sk->sk_socket = sock; 1652 } 1653 1654 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1655 { 1656 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1657 return &rcu_dereference_raw(sk->sk_wq)->wait; 1658 } 1659 /* Detach socket from process context. 1660 * Announce socket dead, detach it from wait queue and inode. 1661 * Note that parent inode held reference count on this struct sock, 1662 * we do not release it in this function, because protocol 1663 * probably wants some additional cleanups or even continuing 1664 * to work with this socket (TCP). 1665 */ 1666 static inline void sock_orphan(struct sock *sk) 1667 { 1668 write_lock_bh(&sk->sk_callback_lock); 1669 sock_set_flag(sk, SOCK_DEAD); 1670 sk_set_socket(sk, NULL); 1671 sk->sk_wq = NULL; 1672 write_unlock_bh(&sk->sk_callback_lock); 1673 } 1674 1675 static inline void sock_graft(struct sock *sk, struct socket *parent) 1676 { 1677 write_lock_bh(&sk->sk_callback_lock); 1678 sk->sk_wq = parent->wq; 1679 parent->sk = sk; 1680 sk_set_socket(sk, parent); 1681 security_sock_graft(sk, parent); 1682 write_unlock_bh(&sk->sk_callback_lock); 1683 } 1684 1685 kuid_t sock_i_uid(struct sock *sk); 1686 unsigned long sock_i_ino(struct sock *sk); 1687 1688 static inline u32 net_tx_rndhash(void) 1689 { 1690 u32 v = prandom_u32(); 1691 1692 return v ?: 1; 1693 } 1694 1695 static inline void sk_set_txhash(struct sock *sk) 1696 { 1697 sk->sk_txhash = net_tx_rndhash(); 1698 } 1699 1700 static inline void sk_rethink_txhash(struct sock *sk) 1701 { 1702 if (sk->sk_txhash) 1703 sk_set_txhash(sk); 1704 } 1705 1706 static inline struct dst_entry * 1707 __sk_dst_get(struct sock *sk) 1708 { 1709 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) || 1710 lockdep_is_held(&sk->sk_lock.slock)); 1711 } 1712 1713 static inline struct dst_entry * 1714 sk_dst_get(struct sock *sk) 1715 { 1716 struct dst_entry *dst; 1717 1718 rcu_read_lock(); 1719 dst = rcu_dereference(sk->sk_dst_cache); 1720 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 1721 dst = NULL; 1722 rcu_read_unlock(); 1723 return dst; 1724 } 1725 1726 static inline void dst_negative_advice(struct sock *sk) 1727 { 1728 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1729 1730 sk_rethink_txhash(sk); 1731 1732 if (dst && dst->ops->negative_advice) { 1733 ndst = dst->ops->negative_advice(dst); 1734 1735 if (ndst != dst) { 1736 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1737 sk_tx_queue_clear(sk); 1738 } 1739 } 1740 } 1741 1742 static inline void 1743 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1744 { 1745 struct dst_entry *old_dst; 1746 1747 sk_tx_queue_clear(sk); 1748 /* 1749 * This can be called while sk is owned by the caller only, 1750 * with no state that can be checked in a rcu_dereference_check() cond 1751 */ 1752 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1753 rcu_assign_pointer(sk->sk_dst_cache, dst); 1754 dst_release(old_dst); 1755 } 1756 1757 static inline void 1758 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1759 { 1760 struct dst_entry *old_dst; 1761 1762 sk_tx_queue_clear(sk); 1763 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 1764 dst_release(old_dst); 1765 } 1766 1767 static inline void 1768 __sk_dst_reset(struct sock *sk) 1769 { 1770 __sk_dst_set(sk, NULL); 1771 } 1772 1773 static inline void 1774 sk_dst_reset(struct sock *sk) 1775 { 1776 sk_dst_set(sk, NULL); 1777 } 1778 1779 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1780 1781 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1782 1783 bool sk_mc_loop(struct sock *sk); 1784 1785 static inline bool sk_can_gso(const struct sock *sk) 1786 { 1787 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1788 } 1789 1790 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1791 1792 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1793 { 1794 sk->sk_route_nocaps |= flags; 1795 sk->sk_route_caps &= ~flags; 1796 } 1797 1798 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1799 struct iov_iter *from, char *to, 1800 int copy, int offset) 1801 { 1802 if (skb->ip_summed == CHECKSUM_NONE) { 1803 __wsum csum = 0; 1804 if (csum_and_copy_from_iter(to, copy, &csum, from) != copy) 1805 return -EFAULT; 1806 skb->csum = csum_block_add(skb->csum, csum, offset); 1807 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1808 if (copy_from_iter_nocache(to, copy, from) != copy) 1809 return -EFAULT; 1810 } else if (copy_from_iter(to, copy, from) != copy) 1811 return -EFAULT; 1812 1813 return 0; 1814 } 1815 1816 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1817 struct iov_iter *from, int copy) 1818 { 1819 int err, offset = skb->len; 1820 1821 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1822 copy, offset); 1823 if (err) 1824 __skb_trim(skb, offset); 1825 1826 return err; 1827 } 1828 1829 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 1830 struct sk_buff *skb, 1831 struct page *page, 1832 int off, int copy) 1833 { 1834 int err; 1835 1836 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1837 copy, skb->len); 1838 if (err) 1839 return err; 1840 1841 skb->len += copy; 1842 skb->data_len += copy; 1843 skb->truesize += copy; 1844 sk->sk_wmem_queued += copy; 1845 sk_mem_charge(sk, copy); 1846 return 0; 1847 } 1848 1849 /** 1850 * sk_wmem_alloc_get - returns write allocations 1851 * @sk: socket 1852 * 1853 * Returns sk_wmem_alloc minus initial offset of one 1854 */ 1855 static inline int sk_wmem_alloc_get(const struct sock *sk) 1856 { 1857 return atomic_read(&sk->sk_wmem_alloc) - 1; 1858 } 1859 1860 /** 1861 * sk_rmem_alloc_get - returns read allocations 1862 * @sk: socket 1863 * 1864 * Returns sk_rmem_alloc 1865 */ 1866 static inline int sk_rmem_alloc_get(const struct sock *sk) 1867 { 1868 return atomic_read(&sk->sk_rmem_alloc); 1869 } 1870 1871 /** 1872 * sk_has_allocations - check if allocations are outstanding 1873 * @sk: socket 1874 * 1875 * Returns true if socket has write or read allocations 1876 */ 1877 static inline bool sk_has_allocations(const struct sock *sk) 1878 { 1879 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1880 } 1881 1882 /** 1883 * wq_has_sleeper - check if there are any waiting processes 1884 * @wq: struct socket_wq 1885 * 1886 * Returns true if socket_wq has waiting processes 1887 * 1888 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory 1889 * barrier call. They were added due to the race found within the tcp code. 1890 * 1891 * Consider following tcp code paths: 1892 * 1893 * CPU1 CPU2 1894 * 1895 * sys_select receive packet 1896 * ... ... 1897 * __add_wait_queue update tp->rcv_nxt 1898 * ... ... 1899 * tp->rcv_nxt check sock_def_readable 1900 * ... { 1901 * schedule rcu_read_lock(); 1902 * wq = rcu_dereference(sk->sk_wq); 1903 * if (wq && waitqueue_active(&wq->wait)) 1904 * wake_up_interruptible(&wq->wait) 1905 * ... 1906 * } 1907 * 1908 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1909 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1910 * could then endup calling schedule and sleep forever if there are no more 1911 * data on the socket. 1912 * 1913 */ 1914 static inline bool wq_has_sleeper(struct socket_wq *wq) 1915 { 1916 /* We need to be sure we are in sync with the 1917 * add_wait_queue modifications to the wait queue. 1918 * 1919 * This memory barrier is paired in the sock_poll_wait. 1920 */ 1921 smp_mb(); 1922 return wq && waitqueue_active(&wq->wait); 1923 } 1924 1925 /** 1926 * sock_poll_wait - place memory barrier behind the poll_wait call. 1927 * @filp: file 1928 * @wait_address: socket wait queue 1929 * @p: poll_table 1930 * 1931 * See the comments in the wq_has_sleeper function. 1932 */ 1933 static inline void sock_poll_wait(struct file *filp, 1934 wait_queue_head_t *wait_address, poll_table *p) 1935 { 1936 if (!poll_does_not_wait(p) && wait_address) { 1937 poll_wait(filp, wait_address, p); 1938 /* We need to be sure we are in sync with the 1939 * socket flags modification. 1940 * 1941 * This memory barrier is paired in the wq_has_sleeper. 1942 */ 1943 smp_mb(); 1944 } 1945 } 1946 1947 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 1948 { 1949 if (sk->sk_txhash) { 1950 skb->l4_hash = 1; 1951 skb->hash = sk->sk_txhash; 1952 } 1953 } 1954 1955 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 1956 1957 /* 1958 * Queue a received datagram if it will fit. Stream and sequenced 1959 * protocols can't normally use this as they need to fit buffers in 1960 * and play with them. 1961 * 1962 * Inlined as it's very short and called for pretty much every 1963 * packet ever received. 1964 */ 1965 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1966 { 1967 skb_orphan(skb); 1968 skb->sk = sk; 1969 skb->destructor = sock_rfree; 1970 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1971 sk_mem_charge(sk, skb->truesize); 1972 } 1973 1974 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 1975 unsigned long expires); 1976 1977 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 1978 1979 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1980 1981 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 1982 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 1983 1984 /* 1985 * Recover an error report and clear atomically 1986 */ 1987 1988 static inline int sock_error(struct sock *sk) 1989 { 1990 int err; 1991 if (likely(!sk->sk_err)) 1992 return 0; 1993 err = xchg(&sk->sk_err, 0); 1994 return -err; 1995 } 1996 1997 static inline unsigned long sock_wspace(struct sock *sk) 1998 { 1999 int amt = 0; 2000 2001 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 2002 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 2003 if (amt < 0) 2004 amt = 0; 2005 } 2006 return amt; 2007 } 2008 2009 /* Note: 2010 * We use sk->sk_wq_raw, from contexts knowing this 2011 * pointer is not NULL and cannot disappear/change. 2012 */ 2013 static inline void sk_set_bit(int nr, struct sock *sk) 2014 { 2015 set_bit(nr, &sk->sk_wq_raw->flags); 2016 } 2017 2018 static inline void sk_clear_bit(int nr, struct sock *sk) 2019 { 2020 clear_bit(nr, &sk->sk_wq_raw->flags); 2021 } 2022 2023 static inline void sk_wake_async(const struct sock *sk, int how, int band) 2024 { 2025 if (sock_flag(sk, SOCK_FASYNC)) { 2026 rcu_read_lock(); 2027 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 2028 rcu_read_unlock(); 2029 } 2030 } 2031 2032 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 2033 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 2034 * Note: for send buffers, TCP works better if we can build two skbs at 2035 * minimum. 2036 */ 2037 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 2038 2039 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 2040 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 2041 2042 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 2043 { 2044 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 2045 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 2046 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); 2047 } 2048 } 2049 2050 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 2051 bool force_schedule); 2052 2053 /** 2054 * sk_page_frag - return an appropriate page_frag 2055 * @sk: socket 2056 * 2057 * If socket allocation mode allows current thread to sleep, it means its 2058 * safe to use the per task page_frag instead of the per socket one. 2059 */ 2060 static inline struct page_frag *sk_page_frag(struct sock *sk) 2061 { 2062 if (gfpflags_allow_blocking(sk->sk_allocation)) 2063 return ¤t->task_frag; 2064 2065 return &sk->sk_frag; 2066 } 2067 2068 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2069 2070 /* 2071 * Default write policy as shown to user space via poll/select/SIGIO 2072 */ 2073 static inline bool sock_writeable(const struct sock *sk) 2074 { 2075 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 2076 } 2077 2078 static inline gfp_t gfp_any(void) 2079 { 2080 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2081 } 2082 2083 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2084 { 2085 return noblock ? 0 : sk->sk_rcvtimeo; 2086 } 2087 2088 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2089 { 2090 return noblock ? 0 : sk->sk_sndtimeo; 2091 } 2092 2093 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2094 { 2095 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 2096 } 2097 2098 /* Alas, with timeout socket operations are not restartable. 2099 * Compare this to poll(). 2100 */ 2101 static inline int sock_intr_errno(long timeo) 2102 { 2103 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2104 } 2105 2106 struct sock_skb_cb { 2107 u32 dropcount; 2108 }; 2109 2110 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2111 * using skb->cb[] would keep using it directly and utilize its 2112 * alignement guarantee. 2113 */ 2114 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \ 2115 sizeof(struct sock_skb_cb))) 2116 2117 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2118 SOCK_SKB_CB_OFFSET)) 2119 2120 #define sock_skb_cb_check_size(size) \ 2121 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2122 2123 static inline void 2124 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2125 { 2126 SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops); 2127 } 2128 2129 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2130 struct sk_buff *skb); 2131 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2132 struct sk_buff *skb); 2133 2134 static inline void 2135 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2136 { 2137 ktime_t kt = skb->tstamp; 2138 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2139 2140 /* 2141 * generate control messages if 2142 * - receive time stamping in software requested 2143 * - software time stamp available and wanted 2144 * - hardware time stamps available and wanted 2145 */ 2146 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2147 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2148 (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2149 (hwtstamps->hwtstamp.tv64 && 2150 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2151 __sock_recv_timestamp(msg, sk, skb); 2152 else 2153 sk->sk_stamp = kt; 2154 2155 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2156 __sock_recv_wifi_status(msg, sk, skb); 2157 } 2158 2159 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2160 struct sk_buff *skb); 2161 2162 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2163 struct sk_buff *skb) 2164 { 2165 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2166 (1UL << SOCK_RCVTSTAMP)) 2167 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2168 SOF_TIMESTAMPING_RAW_HARDWARE) 2169 2170 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2171 __sock_recv_ts_and_drops(msg, sk, skb); 2172 else 2173 sk->sk_stamp = skb->tstamp; 2174 } 2175 2176 void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags); 2177 2178 /** 2179 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2180 * @sk: socket sending this packet 2181 * @tx_flags: completed with instructions for time stamping 2182 * 2183 * Note : callers should take care of initial *tx_flags value (usually 0) 2184 */ 2185 static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags) 2186 { 2187 if (unlikely(sk->sk_tsflags)) 2188 __sock_tx_timestamp(sk, tx_flags); 2189 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2190 *tx_flags |= SKBTX_WIFI_STATUS; 2191 } 2192 2193 /** 2194 * sk_eat_skb - Release a skb if it is no longer needed 2195 * @sk: socket to eat this skb from 2196 * @skb: socket buffer to eat 2197 * 2198 * This routine must be called with interrupts disabled or with the socket 2199 * locked so that the sk_buff queue operation is ok. 2200 */ 2201 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2202 { 2203 __skb_unlink(skb, &sk->sk_receive_queue); 2204 __kfree_skb(skb); 2205 } 2206 2207 static inline 2208 struct net *sock_net(const struct sock *sk) 2209 { 2210 return read_pnet(&sk->sk_net); 2211 } 2212 2213 static inline 2214 void sock_net_set(struct sock *sk, struct net *net) 2215 { 2216 write_pnet(&sk->sk_net, net); 2217 } 2218 2219 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2220 { 2221 if (skb->sk) { 2222 struct sock *sk = skb->sk; 2223 2224 skb->destructor = NULL; 2225 skb->sk = NULL; 2226 return sk; 2227 } 2228 return NULL; 2229 } 2230 2231 /* This helper checks if a socket is a full socket, 2232 * ie _not_ a timewait or request socket. 2233 */ 2234 static inline bool sk_fullsock(const struct sock *sk) 2235 { 2236 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2237 } 2238 2239 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2240 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2241 */ 2242 static inline bool sk_listener(const struct sock *sk) 2243 { 2244 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2245 } 2246 2247 /** 2248 * sk_state_load - read sk->sk_state for lockless contexts 2249 * @sk: socket pointer 2250 * 2251 * Paired with sk_state_store(). Used in places we do not hold socket lock : 2252 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... 2253 */ 2254 static inline int sk_state_load(const struct sock *sk) 2255 { 2256 return smp_load_acquire(&sk->sk_state); 2257 } 2258 2259 /** 2260 * sk_state_store - update sk->sk_state 2261 * @sk: socket pointer 2262 * @newstate: new state 2263 * 2264 * Paired with sk_state_load(). Should be used in contexts where 2265 * state change might impact lockless readers. 2266 */ 2267 static inline void sk_state_store(struct sock *sk, int newstate) 2268 { 2269 smp_store_release(&sk->sk_state, newstate); 2270 } 2271 2272 void sock_enable_timestamp(struct sock *sk, int flag); 2273 int sock_get_timestamp(struct sock *, struct timeval __user *); 2274 int sock_get_timestampns(struct sock *, struct timespec __user *); 2275 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2276 int type); 2277 2278 bool sk_ns_capable(const struct sock *sk, 2279 struct user_namespace *user_ns, int cap); 2280 bool sk_capable(const struct sock *sk, int cap); 2281 bool sk_net_capable(const struct sock *sk, int cap); 2282 2283 extern __u32 sysctl_wmem_max; 2284 extern __u32 sysctl_rmem_max; 2285 2286 extern int sysctl_tstamp_allow_data; 2287 extern int sysctl_optmem_max; 2288 2289 extern __u32 sysctl_wmem_default; 2290 extern __u32 sysctl_rmem_default; 2291 2292 #endif /* _SOCK_H */ 2293