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 #include <linux/wait.h> 62 #include <linux/cgroup-defs.h> 63 64 #include <linux/filter.h> 65 #include <linux/rculist_nulls.h> 66 #include <linux/poll.h> 67 68 #include <linux/atomic.h> 69 #include <net/dst.h> 70 #include <net/checksum.h> 71 #include <net/tcp_states.h> 72 #include <linux/net_tstamp.h> 73 74 /* 75 * This structure really needs to be cleaned up. 76 * Most of it is for TCP, and not used by any of 77 * the other protocols. 78 */ 79 80 /* Define this to get the SOCK_DBG debugging facility. */ 81 #define SOCK_DEBUGGING 82 #ifdef SOCK_DEBUGGING 83 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 84 printk(KERN_DEBUG msg); } while (0) 85 #else 86 /* Validate arguments and do nothing */ 87 static inline __printf(2, 3) 88 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 89 { 90 } 91 #endif 92 93 /* This is the per-socket lock. The spinlock provides a synchronization 94 * between user contexts and software interrupt processing, whereas the 95 * mini-semaphore synchronizes multiple users amongst themselves. 96 */ 97 typedef struct { 98 spinlock_t slock; 99 int owned; 100 wait_queue_head_t wq; 101 /* 102 * We express the mutex-alike socket_lock semantics 103 * to the lock validator by explicitly managing 104 * the slock as a lock variant (in addition to 105 * the slock itself): 106 */ 107 #ifdef CONFIG_DEBUG_LOCK_ALLOC 108 struct lockdep_map dep_map; 109 #endif 110 } socket_lock_t; 111 112 struct sock; 113 struct proto; 114 struct net; 115 116 typedef __u32 __bitwise __portpair; 117 typedef __u64 __bitwise __addrpair; 118 119 /** 120 * struct sock_common - minimal network layer representation of sockets 121 * @skc_daddr: Foreign IPv4 addr 122 * @skc_rcv_saddr: Bound local IPv4 addr 123 * @skc_hash: hash value used with various protocol lookup tables 124 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 125 * @skc_dport: placeholder for inet_dport/tw_dport 126 * @skc_num: placeholder for inet_num/tw_num 127 * @skc_family: network address family 128 * @skc_state: Connection state 129 * @skc_reuse: %SO_REUSEADDR setting 130 * @skc_reuseport: %SO_REUSEPORT setting 131 * @skc_bound_dev_if: bound device index if != 0 132 * @skc_bind_node: bind hash linkage for various protocol lookup tables 133 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 134 * @skc_prot: protocol handlers inside a network family 135 * @skc_net: reference to the network namespace of this socket 136 * @skc_node: main hash linkage for various protocol lookup tables 137 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 138 * @skc_tx_queue_mapping: tx queue number for this connection 139 * @skc_flags: place holder for sk_flags 140 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 141 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 142 * @skc_incoming_cpu: record/match cpu processing incoming packets 143 * @skc_refcnt: reference count 144 * 145 * This is the minimal network layer representation of sockets, the header 146 * for struct sock and struct inet_timewait_sock. 147 */ 148 struct sock_common { 149 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 150 * address on 64bit arches : cf INET_MATCH() 151 */ 152 union { 153 __addrpair skc_addrpair; 154 struct { 155 __be32 skc_daddr; 156 __be32 skc_rcv_saddr; 157 }; 158 }; 159 union { 160 unsigned int skc_hash; 161 __u16 skc_u16hashes[2]; 162 }; 163 /* skc_dport && skc_num must be grouped as well */ 164 union { 165 __portpair skc_portpair; 166 struct { 167 __be16 skc_dport; 168 __u16 skc_num; 169 }; 170 }; 171 172 unsigned short skc_family; 173 volatile unsigned char skc_state; 174 unsigned char skc_reuse:4; 175 unsigned char skc_reuseport:1; 176 unsigned char skc_ipv6only:1; 177 unsigned char skc_net_refcnt:1; 178 int skc_bound_dev_if; 179 union { 180 struct hlist_node skc_bind_node; 181 struct hlist_node skc_portaddr_node; 182 }; 183 struct proto *skc_prot; 184 possible_net_t skc_net; 185 186 #if IS_ENABLED(CONFIG_IPV6) 187 struct in6_addr skc_v6_daddr; 188 struct in6_addr skc_v6_rcv_saddr; 189 #endif 190 191 atomic64_t skc_cookie; 192 193 /* following fields are padding to force 194 * offset(struct sock, sk_refcnt) == 128 on 64bit arches 195 * assuming IPV6 is enabled. We use this padding differently 196 * for different kind of 'sockets' 197 */ 198 union { 199 unsigned long skc_flags; 200 struct sock *skc_listener; /* request_sock */ 201 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */ 202 }; 203 /* 204 * fields between dontcopy_begin/dontcopy_end 205 * are not copied in sock_copy() 206 */ 207 /* private: */ 208 int skc_dontcopy_begin[0]; 209 /* public: */ 210 union { 211 struct hlist_node skc_node; 212 struct hlist_nulls_node skc_nulls_node; 213 }; 214 int skc_tx_queue_mapping; 215 union { 216 int skc_incoming_cpu; 217 u32 skc_rcv_wnd; 218 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */ 219 }; 220 221 atomic_t skc_refcnt; 222 /* private: */ 223 int skc_dontcopy_end[0]; 224 union { 225 u32 skc_rxhash; 226 u32 skc_window_clamp; 227 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ 228 }; 229 /* public: */ 230 }; 231 232 /** 233 * struct sock - network layer representation of sockets 234 * @__sk_common: shared layout with inet_timewait_sock 235 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 236 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 237 * @sk_lock: synchronizer 238 * @sk_rcvbuf: size of receive buffer in bytes 239 * @sk_wq: sock wait queue and async head 240 * @sk_rx_dst: receive input route used by early demux 241 * @sk_dst_cache: destination cache 242 * @sk_policy: flow policy 243 * @sk_receive_queue: incoming packets 244 * @sk_wmem_alloc: transmit queue bytes committed 245 * @sk_write_queue: Packet sending queue 246 * @sk_omem_alloc: "o" is "option" or "other" 247 * @sk_wmem_queued: persistent queue size 248 * @sk_forward_alloc: space allocated forward 249 * @sk_napi_id: id of the last napi context to receive data for sk 250 * @sk_ll_usec: usecs to busypoll when there is no data 251 * @sk_allocation: allocation mode 252 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler) 253 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE) 254 * @sk_sndbuf: size of send buffer in bytes 255 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets 256 * @sk_no_check_rx: allow zero checksum in RX packets 257 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 258 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 259 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 260 * @sk_gso_max_size: Maximum GSO segment size to build 261 * @sk_gso_max_segs: Maximum number of GSO segments 262 * @sk_lingertime: %SO_LINGER l_linger setting 263 * @sk_backlog: always used with the per-socket spinlock held 264 * @sk_callback_lock: used with the callbacks in the end of this struct 265 * @sk_error_queue: rarely used 266 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 267 * IPV6_ADDRFORM for instance) 268 * @sk_err: last error 269 * @sk_err_soft: errors that don't cause failure but are the cause of a 270 * persistent failure not just 'timed out' 271 * @sk_drops: raw/udp drops counter 272 * @sk_ack_backlog: current listen backlog 273 * @sk_max_ack_backlog: listen backlog set in listen() 274 * @sk_priority: %SO_PRIORITY setting 275 * @sk_type: socket type (%SOCK_STREAM, etc) 276 * @sk_protocol: which protocol this socket belongs in this network family 277 * @sk_peer_pid: &struct pid for this socket's peer 278 * @sk_peer_cred: %SO_PEERCRED setting 279 * @sk_rcvlowat: %SO_RCVLOWAT setting 280 * @sk_rcvtimeo: %SO_RCVTIMEO setting 281 * @sk_sndtimeo: %SO_SNDTIMEO setting 282 * @sk_txhash: computed flow hash for use on transmit 283 * @sk_filter: socket filtering instructions 284 * @sk_timer: sock cleanup timer 285 * @sk_stamp: time stamp of last packet received 286 * @sk_tsflags: SO_TIMESTAMPING socket options 287 * @sk_tskey: counter to disambiguate concurrent tstamp requests 288 * @sk_socket: Identd and reporting IO signals 289 * @sk_user_data: RPC layer private data 290 * @sk_frag: cached page frag 291 * @sk_peek_off: current peek_offset value 292 * @sk_send_head: front of stuff to transmit 293 * @sk_security: used by security modules 294 * @sk_mark: generic packet mark 295 * @sk_cgrp_data: cgroup data for this cgroup 296 * @sk_memcg: this socket's memory cgroup association 297 * @sk_write_pending: a write to stream socket waits to start 298 * @sk_state_change: callback to indicate change in the state of the sock 299 * @sk_data_ready: callback to indicate there is data to be processed 300 * @sk_write_space: callback to indicate there is bf sending space available 301 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 302 * @sk_backlog_rcv: callback to process the backlog 303 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 304 * @sk_reuseport_cb: reuseport group container 305 */ 306 struct sock { 307 /* 308 * Now struct inet_timewait_sock also uses sock_common, so please just 309 * don't add nothing before this first member (__sk_common) --acme 310 */ 311 struct sock_common __sk_common; 312 #define sk_node __sk_common.skc_node 313 #define sk_nulls_node __sk_common.skc_nulls_node 314 #define sk_refcnt __sk_common.skc_refcnt 315 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 316 317 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 318 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 319 #define sk_hash __sk_common.skc_hash 320 #define sk_portpair __sk_common.skc_portpair 321 #define sk_num __sk_common.skc_num 322 #define sk_dport __sk_common.skc_dport 323 #define sk_addrpair __sk_common.skc_addrpair 324 #define sk_daddr __sk_common.skc_daddr 325 #define sk_rcv_saddr __sk_common.skc_rcv_saddr 326 #define sk_family __sk_common.skc_family 327 #define sk_state __sk_common.skc_state 328 #define sk_reuse __sk_common.skc_reuse 329 #define sk_reuseport __sk_common.skc_reuseport 330 #define sk_ipv6only __sk_common.skc_ipv6only 331 #define sk_net_refcnt __sk_common.skc_net_refcnt 332 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 333 #define sk_bind_node __sk_common.skc_bind_node 334 #define sk_prot __sk_common.skc_prot 335 #define sk_net __sk_common.skc_net 336 #define sk_v6_daddr __sk_common.skc_v6_daddr 337 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr 338 #define sk_cookie __sk_common.skc_cookie 339 #define sk_incoming_cpu __sk_common.skc_incoming_cpu 340 #define sk_flags __sk_common.skc_flags 341 #define sk_rxhash __sk_common.skc_rxhash 342 343 socket_lock_t sk_lock; 344 struct sk_buff_head sk_receive_queue; 345 /* 346 * The backlog queue is special, it is always used with 347 * the per-socket spinlock held and requires low latency 348 * access. Therefore we special case it's implementation. 349 * Note : rmem_alloc is in this structure to fill a hole 350 * on 64bit arches, not because its logically part of 351 * backlog. 352 */ 353 struct { 354 atomic_t rmem_alloc; 355 int len; 356 struct sk_buff *head; 357 struct sk_buff *tail; 358 } sk_backlog; 359 #define sk_rmem_alloc sk_backlog.rmem_alloc 360 int sk_forward_alloc; 361 362 __u32 sk_txhash; 363 #ifdef CONFIG_NET_RX_BUSY_POLL 364 unsigned int sk_napi_id; 365 unsigned int sk_ll_usec; 366 #endif 367 atomic_t sk_drops; 368 int sk_rcvbuf; 369 370 struct sk_filter __rcu *sk_filter; 371 union { 372 struct socket_wq __rcu *sk_wq; 373 struct socket_wq *sk_wq_raw; 374 }; 375 #ifdef CONFIG_XFRM 376 struct xfrm_policy __rcu *sk_policy[2]; 377 #endif 378 struct dst_entry *sk_rx_dst; 379 struct dst_entry __rcu *sk_dst_cache; 380 /* Note: 32bit hole on 64bit arches */ 381 atomic_t sk_wmem_alloc; 382 atomic_t sk_omem_alloc; 383 int sk_sndbuf; 384 struct sk_buff_head sk_write_queue; 385 kmemcheck_bitfield_begin(flags); 386 unsigned int sk_shutdown : 2, 387 sk_no_check_tx : 1, 388 sk_no_check_rx : 1, 389 sk_userlocks : 4, 390 sk_protocol : 8, 391 sk_type : 16; 392 #define SK_PROTOCOL_MAX U8_MAX 393 kmemcheck_bitfield_end(flags); 394 int sk_wmem_queued; 395 gfp_t sk_allocation; 396 u32 sk_pacing_rate; /* bytes per second */ 397 u32 sk_max_pacing_rate; 398 netdev_features_t sk_route_caps; 399 netdev_features_t sk_route_nocaps; 400 int sk_gso_type; 401 unsigned int sk_gso_max_size; 402 u16 sk_gso_max_segs; 403 int sk_rcvlowat; 404 unsigned long sk_lingertime; 405 struct sk_buff_head sk_error_queue; 406 struct proto *sk_prot_creator; 407 rwlock_t sk_callback_lock; 408 int sk_err, 409 sk_err_soft; 410 u32 sk_ack_backlog; 411 u32 sk_max_ack_backlog; 412 __u32 sk_priority; 413 __u32 sk_mark; 414 struct pid *sk_peer_pid; 415 const struct cred *sk_peer_cred; 416 long sk_rcvtimeo; 417 long sk_sndtimeo; 418 struct timer_list sk_timer; 419 ktime_t sk_stamp; 420 u16 sk_tsflags; 421 u32 sk_tskey; 422 struct socket *sk_socket; 423 void *sk_user_data; 424 struct page_frag sk_frag; 425 struct sk_buff *sk_send_head; 426 __s32 sk_peek_off; 427 int sk_write_pending; 428 #ifdef CONFIG_SECURITY 429 void *sk_security; 430 #endif 431 struct sock_cgroup_data sk_cgrp_data; 432 struct mem_cgroup *sk_memcg; 433 void (*sk_state_change)(struct sock *sk); 434 void (*sk_data_ready)(struct sock *sk); 435 void (*sk_write_space)(struct sock *sk); 436 void (*sk_error_report)(struct sock *sk); 437 int (*sk_backlog_rcv)(struct sock *sk, 438 struct sk_buff *skb); 439 void (*sk_destruct)(struct sock *sk); 440 struct sock_reuseport __rcu *sk_reuseport_cb; 441 struct rcu_head sk_rcu; 442 }; 443 444 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) 445 446 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) 447 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) 448 449 /* 450 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 451 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 452 * on a socket means that the socket will reuse everybody else's port 453 * without looking at the other's sk_reuse value. 454 */ 455 456 #define SK_NO_REUSE 0 457 #define SK_CAN_REUSE 1 458 #define SK_FORCE_REUSE 2 459 460 int sk_set_peek_off(struct sock *sk, int val); 461 462 static inline int sk_peek_offset(struct sock *sk, int flags) 463 { 464 if (unlikely(flags & MSG_PEEK)) { 465 s32 off = READ_ONCE(sk->sk_peek_off); 466 if (off >= 0) 467 return off; 468 } 469 470 return 0; 471 } 472 473 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 474 { 475 s32 off = READ_ONCE(sk->sk_peek_off); 476 477 if (unlikely(off >= 0)) { 478 off = max_t(s32, off - val, 0); 479 WRITE_ONCE(sk->sk_peek_off, off); 480 } 481 } 482 483 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 484 { 485 sk_peek_offset_bwd(sk, -val); 486 } 487 488 /* 489 * Hashed lists helper routines 490 */ 491 static inline struct sock *sk_entry(const struct hlist_node *node) 492 { 493 return hlist_entry(node, struct sock, sk_node); 494 } 495 496 static inline struct sock *__sk_head(const struct hlist_head *head) 497 { 498 return hlist_entry(head->first, struct sock, sk_node); 499 } 500 501 static inline struct sock *sk_head(const struct hlist_head *head) 502 { 503 return hlist_empty(head) ? NULL : __sk_head(head); 504 } 505 506 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 507 { 508 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 509 } 510 511 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 512 { 513 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 514 } 515 516 static inline struct sock *sk_next(const struct sock *sk) 517 { 518 return sk->sk_node.next ? 519 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 520 } 521 522 static inline struct sock *sk_nulls_next(const struct sock *sk) 523 { 524 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 525 hlist_nulls_entry(sk->sk_nulls_node.next, 526 struct sock, sk_nulls_node) : 527 NULL; 528 } 529 530 static inline bool sk_unhashed(const struct sock *sk) 531 { 532 return hlist_unhashed(&sk->sk_node); 533 } 534 535 static inline bool sk_hashed(const struct sock *sk) 536 { 537 return !sk_unhashed(sk); 538 } 539 540 static inline void sk_node_init(struct hlist_node *node) 541 { 542 node->pprev = NULL; 543 } 544 545 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 546 { 547 node->pprev = NULL; 548 } 549 550 static inline void __sk_del_node(struct sock *sk) 551 { 552 __hlist_del(&sk->sk_node); 553 } 554 555 /* NB: equivalent to hlist_del_init_rcu */ 556 static inline bool __sk_del_node_init(struct sock *sk) 557 { 558 if (sk_hashed(sk)) { 559 __sk_del_node(sk); 560 sk_node_init(&sk->sk_node); 561 return true; 562 } 563 return false; 564 } 565 566 /* Grab socket reference count. This operation is valid only 567 when sk is ALREADY grabbed f.e. it is found in hash table 568 or a list and the lookup is made under lock preventing hash table 569 modifications. 570 */ 571 572 static __always_inline void sock_hold(struct sock *sk) 573 { 574 atomic_inc(&sk->sk_refcnt); 575 } 576 577 /* Ungrab socket in the context, which assumes that socket refcnt 578 cannot hit zero, f.e. it is true in context of any socketcall. 579 */ 580 static __always_inline void __sock_put(struct sock *sk) 581 { 582 atomic_dec(&sk->sk_refcnt); 583 } 584 585 static inline bool sk_del_node_init(struct sock *sk) 586 { 587 bool rc = __sk_del_node_init(sk); 588 589 if (rc) { 590 /* paranoid for a while -acme */ 591 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 592 __sock_put(sk); 593 } 594 return rc; 595 } 596 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 597 598 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 599 { 600 if (sk_hashed(sk)) { 601 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 602 return true; 603 } 604 return false; 605 } 606 607 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 608 { 609 bool rc = __sk_nulls_del_node_init_rcu(sk); 610 611 if (rc) { 612 /* paranoid for a while -acme */ 613 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 614 __sock_put(sk); 615 } 616 return rc; 617 } 618 619 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 620 { 621 hlist_add_head(&sk->sk_node, list); 622 } 623 624 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 625 { 626 sock_hold(sk); 627 __sk_add_node(sk, list); 628 } 629 630 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 631 { 632 sock_hold(sk); 633 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 634 sk->sk_family == AF_INET6) 635 hlist_add_tail_rcu(&sk->sk_node, list); 636 else 637 hlist_add_head_rcu(&sk->sk_node, list); 638 } 639 640 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 641 { 642 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 643 sk->sk_family == AF_INET6) 644 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list); 645 else 646 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 647 } 648 649 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 650 { 651 sock_hold(sk); 652 __sk_nulls_add_node_rcu(sk, list); 653 } 654 655 static inline void __sk_del_bind_node(struct sock *sk) 656 { 657 __hlist_del(&sk->sk_bind_node); 658 } 659 660 static inline void sk_add_bind_node(struct sock *sk, 661 struct hlist_head *list) 662 { 663 hlist_add_head(&sk->sk_bind_node, list); 664 } 665 666 #define sk_for_each(__sk, list) \ 667 hlist_for_each_entry(__sk, list, sk_node) 668 #define sk_for_each_rcu(__sk, list) \ 669 hlist_for_each_entry_rcu(__sk, list, sk_node) 670 #define sk_nulls_for_each(__sk, node, list) \ 671 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 672 #define sk_nulls_for_each_rcu(__sk, node, list) \ 673 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 674 #define sk_for_each_from(__sk) \ 675 hlist_for_each_entry_from(__sk, sk_node) 676 #define sk_nulls_for_each_from(__sk, node) \ 677 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 678 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 679 #define sk_for_each_safe(__sk, tmp, list) \ 680 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 681 #define sk_for_each_bound(__sk, list) \ 682 hlist_for_each_entry(__sk, list, sk_bind_node) 683 684 /** 685 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset 686 * @tpos: the type * to use as a loop cursor. 687 * @pos: the &struct hlist_node to use as a loop cursor. 688 * @head: the head for your list. 689 * @offset: offset of hlist_node within the struct. 690 * 691 */ 692 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \ 693 for (pos = rcu_dereference((head)->first); \ 694 pos != NULL && \ 695 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 696 pos = rcu_dereference(pos->next)) 697 698 static inline struct user_namespace *sk_user_ns(struct sock *sk) 699 { 700 /* Careful only use this in a context where these parameters 701 * can not change and must all be valid, such as recvmsg from 702 * userspace. 703 */ 704 return sk->sk_socket->file->f_cred->user_ns; 705 } 706 707 /* Sock flags */ 708 enum sock_flags { 709 SOCK_DEAD, 710 SOCK_DONE, 711 SOCK_URGINLINE, 712 SOCK_KEEPOPEN, 713 SOCK_LINGER, 714 SOCK_DESTROY, 715 SOCK_BROADCAST, 716 SOCK_TIMESTAMP, 717 SOCK_ZAPPED, 718 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 719 SOCK_DBG, /* %SO_DEBUG setting */ 720 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 721 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 722 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 723 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 724 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 725 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 726 SOCK_FASYNC, /* fasync() active */ 727 SOCK_RXQ_OVFL, 728 SOCK_ZEROCOPY, /* buffers from userspace */ 729 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 730 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 731 * Will use last 4 bytes of packet sent from 732 * user-space instead. 733 */ 734 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 735 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 736 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */ 737 }; 738 739 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) 740 741 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 742 { 743 nsk->sk_flags = osk->sk_flags; 744 } 745 746 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 747 { 748 __set_bit(flag, &sk->sk_flags); 749 } 750 751 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 752 { 753 __clear_bit(flag, &sk->sk_flags); 754 } 755 756 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 757 { 758 return test_bit(flag, &sk->sk_flags); 759 } 760 761 #ifdef CONFIG_NET 762 extern struct static_key memalloc_socks; 763 static inline int sk_memalloc_socks(void) 764 { 765 return static_key_false(&memalloc_socks); 766 } 767 #else 768 769 static inline int sk_memalloc_socks(void) 770 { 771 return 0; 772 } 773 774 #endif 775 776 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 777 { 778 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC); 779 } 780 781 static inline void sk_acceptq_removed(struct sock *sk) 782 { 783 sk->sk_ack_backlog--; 784 } 785 786 static inline void sk_acceptq_added(struct sock *sk) 787 { 788 sk->sk_ack_backlog++; 789 } 790 791 static inline bool sk_acceptq_is_full(const struct sock *sk) 792 { 793 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 794 } 795 796 /* 797 * Compute minimal free write space needed to queue new packets. 798 */ 799 static inline int sk_stream_min_wspace(const struct sock *sk) 800 { 801 return sk->sk_wmem_queued >> 1; 802 } 803 804 static inline int sk_stream_wspace(const struct sock *sk) 805 { 806 return sk->sk_sndbuf - sk->sk_wmem_queued; 807 } 808 809 void sk_stream_write_space(struct sock *sk); 810 811 /* OOB backlog add */ 812 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 813 { 814 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 815 skb_dst_force_safe(skb); 816 817 if (!sk->sk_backlog.tail) 818 sk->sk_backlog.head = skb; 819 else 820 sk->sk_backlog.tail->next = skb; 821 822 sk->sk_backlog.tail = skb; 823 skb->next = NULL; 824 } 825 826 /* 827 * Take into account size of receive queue and backlog queue 828 * Do not take into account this skb truesize, 829 * to allow even a single big packet to come. 830 */ 831 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 832 { 833 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 834 835 return qsize > limit; 836 } 837 838 /* The per-socket spinlock must be held here. */ 839 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 840 unsigned int limit) 841 { 842 if (sk_rcvqueues_full(sk, limit)) 843 return -ENOBUFS; 844 845 /* 846 * If the skb was allocated from pfmemalloc reserves, only 847 * allow SOCK_MEMALLOC sockets to use it as this socket is 848 * helping free memory 849 */ 850 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 851 return -ENOMEM; 852 853 __sk_add_backlog(sk, skb); 854 sk->sk_backlog.len += skb->truesize; 855 return 0; 856 } 857 858 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 859 860 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 861 { 862 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 863 return __sk_backlog_rcv(sk, skb); 864 865 return sk->sk_backlog_rcv(sk, skb); 866 } 867 868 static inline void sk_incoming_cpu_update(struct sock *sk) 869 { 870 sk->sk_incoming_cpu = raw_smp_processor_id(); 871 } 872 873 static inline void sock_rps_record_flow_hash(__u32 hash) 874 { 875 #ifdef CONFIG_RPS 876 struct rps_sock_flow_table *sock_flow_table; 877 878 rcu_read_lock(); 879 sock_flow_table = rcu_dereference(rps_sock_flow_table); 880 rps_record_sock_flow(sock_flow_table, hash); 881 rcu_read_unlock(); 882 #endif 883 } 884 885 static inline void sock_rps_record_flow(const struct sock *sk) 886 { 887 #ifdef CONFIG_RPS 888 sock_rps_record_flow_hash(sk->sk_rxhash); 889 #endif 890 } 891 892 static inline void sock_rps_save_rxhash(struct sock *sk, 893 const struct sk_buff *skb) 894 { 895 #ifdef CONFIG_RPS 896 if (unlikely(sk->sk_rxhash != skb->hash)) 897 sk->sk_rxhash = skb->hash; 898 #endif 899 } 900 901 static inline void sock_rps_reset_rxhash(struct sock *sk) 902 { 903 #ifdef CONFIG_RPS 904 sk->sk_rxhash = 0; 905 #endif 906 } 907 908 #define sk_wait_event(__sk, __timeo, __condition) \ 909 ({ int __rc; \ 910 release_sock(__sk); \ 911 __rc = __condition; \ 912 if (!__rc) { \ 913 *(__timeo) = schedule_timeout(*(__timeo)); \ 914 } \ 915 sched_annotate_sleep(); \ 916 lock_sock(__sk); \ 917 __rc = __condition; \ 918 __rc; \ 919 }) 920 921 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 922 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 923 void sk_stream_wait_close(struct sock *sk, long timeo_p); 924 int sk_stream_error(struct sock *sk, int flags, int err); 925 void sk_stream_kill_queues(struct sock *sk); 926 void sk_set_memalloc(struct sock *sk); 927 void sk_clear_memalloc(struct sock *sk); 928 929 void __sk_flush_backlog(struct sock *sk); 930 931 static inline bool sk_flush_backlog(struct sock *sk) 932 { 933 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) { 934 __sk_flush_backlog(sk); 935 return true; 936 } 937 return false; 938 } 939 940 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 941 942 struct request_sock_ops; 943 struct timewait_sock_ops; 944 struct inet_hashinfo; 945 struct raw_hashinfo; 946 struct module; 947 948 /* 949 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes 950 * un-modified. Special care is taken when initializing object to zero. 951 */ 952 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 953 { 954 if (offsetof(struct sock, sk_node.next) != 0) 955 memset(sk, 0, offsetof(struct sock, sk_node.next)); 956 memset(&sk->sk_node.pprev, 0, 957 size - offsetof(struct sock, sk_node.pprev)); 958 } 959 960 /* Networking protocol blocks we attach to sockets. 961 * socket layer -> transport layer interface 962 */ 963 struct proto { 964 void (*close)(struct sock *sk, 965 long timeout); 966 int (*connect)(struct sock *sk, 967 struct sockaddr *uaddr, 968 int addr_len); 969 int (*disconnect)(struct sock *sk, int flags); 970 971 struct sock * (*accept)(struct sock *sk, int flags, int *err); 972 973 int (*ioctl)(struct sock *sk, int cmd, 974 unsigned long arg); 975 int (*init)(struct sock *sk); 976 void (*destroy)(struct sock *sk); 977 void (*shutdown)(struct sock *sk, int how); 978 int (*setsockopt)(struct sock *sk, int level, 979 int optname, char __user *optval, 980 unsigned int optlen); 981 int (*getsockopt)(struct sock *sk, int level, 982 int optname, char __user *optval, 983 int __user *option); 984 #ifdef CONFIG_COMPAT 985 int (*compat_setsockopt)(struct sock *sk, 986 int level, 987 int optname, char __user *optval, 988 unsigned int optlen); 989 int (*compat_getsockopt)(struct sock *sk, 990 int level, 991 int optname, char __user *optval, 992 int __user *option); 993 int (*compat_ioctl)(struct sock *sk, 994 unsigned int cmd, unsigned long arg); 995 #endif 996 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 997 size_t len); 998 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 999 size_t len, int noblock, int flags, 1000 int *addr_len); 1001 int (*sendpage)(struct sock *sk, struct page *page, 1002 int offset, size_t size, int flags); 1003 int (*bind)(struct sock *sk, 1004 struct sockaddr *uaddr, int addr_len); 1005 1006 int (*backlog_rcv) (struct sock *sk, 1007 struct sk_buff *skb); 1008 1009 void (*release_cb)(struct sock *sk); 1010 1011 /* Keeping track of sk's, looking them up, and port selection methods. */ 1012 int (*hash)(struct sock *sk); 1013 void (*unhash)(struct sock *sk); 1014 void (*rehash)(struct sock *sk); 1015 int (*get_port)(struct sock *sk, unsigned short snum); 1016 void (*clear_sk)(struct sock *sk, int size); 1017 1018 /* Keeping track of sockets in use */ 1019 #ifdef CONFIG_PROC_FS 1020 unsigned int inuse_idx; 1021 #endif 1022 1023 bool (*stream_memory_free)(const struct sock *sk); 1024 /* Memory pressure */ 1025 void (*enter_memory_pressure)(struct sock *sk); 1026 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1027 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1028 /* 1029 * Pressure flag: try to collapse. 1030 * Technical note: it is used by multiple contexts non atomically. 1031 * All the __sk_mem_schedule() is of this nature: accounting 1032 * is strict, actions are advisory and have some latency. 1033 */ 1034 int *memory_pressure; 1035 long *sysctl_mem; 1036 int *sysctl_wmem; 1037 int *sysctl_rmem; 1038 int max_header; 1039 bool no_autobind; 1040 1041 struct kmem_cache *slab; 1042 unsigned int obj_size; 1043 int slab_flags; 1044 1045 struct percpu_counter *orphan_count; 1046 1047 struct request_sock_ops *rsk_prot; 1048 struct timewait_sock_ops *twsk_prot; 1049 1050 union { 1051 struct inet_hashinfo *hashinfo; 1052 struct udp_table *udp_table; 1053 struct raw_hashinfo *raw_hash; 1054 } h; 1055 1056 struct module *owner; 1057 1058 char name[32]; 1059 1060 struct list_head node; 1061 #ifdef SOCK_REFCNT_DEBUG 1062 atomic_t socks; 1063 #endif 1064 int (*diag_destroy)(struct sock *sk, int err); 1065 }; 1066 1067 int proto_register(struct proto *prot, int alloc_slab); 1068 void proto_unregister(struct proto *prot); 1069 1070 #ifdef SOCK_REFCNT_DEBUG 1071 static inline void sk_refcnt_debug_inc(struct sock *sk) 1072 { 1073 atomic_inc(&sk->sk_prot->socks); 1074 } 1075 1076 static inline void sk_refcnt_debug_dec(struct sock *sk) 1077 { 1078 atomic_dec(&sk->sk_prot->socks); 1079 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1080 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1081 } 1082 1083 static inline void sk_refcnt_debug_release(const struct sock *sk) 1084 { 1085 if (atomic_read(&sk->sk_refcnt) != 1) 1086 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1087 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 1088 } 1089 #else /* SOCK_REFCNT_DEBUG */ 1090 #define sk_refcnt_debug_inc(sk) do { } while (0) 1091 #define sk_refcnt_debug_dec(sk) do { } while (0) 1092 #define sk_refcnt_debug_release(sk) do { } while (0) 1093 #endif /* SOCK_REFCNT_DEBUG */ 1094 1095 static inline bool sk_stream_memory_free(const struct sock *sk) 1096 { 1097 if (sk->sk_wmem_queued >= sk->sk_sndbuf) 1098 return false; 1099 1100 return sk->sk_prot->stream_memory_free ? 1101 sk->sk_prot->stream_memory_free(sk) : true; 1102 } 1103 1104 static inline bool sk_stream_is_writeable(const struct sock *sk) 1105 { 1106 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1107 sk_stream_memory_free(sk); 1108 } 1109 1110 1111 static inline bool sk_has_memory_pressure(const struct sock *sk) 1112 { 1113 return sk->sk_prot->memory_pressure != NULL; 1114 } 1115 1116 static inline bool sk_under_memory_pressure(const struct sock *sk) 1117 { 1118 if (!sk->sk_prot->memory_pressure) 1119 return false; 1120 1121 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 1122 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 1123 return true; 1124 1125 return !!*sk->sk_prot->memory_pressure; 1126 } 1127 1128 static inline void sk_leave_memory_pressure(struct sock *sk) 1129 { 1130 int *memory_pressure = sk->sk_prot->memory_pressure; 1131 1132 if (!memory_pressure) 1133 return; 1134 1135 if (*memory_pressure) 1136 *memory_pressure = 0; 1137 } 1138 1139 static inline void sk_enter_memory_pressure(struct sock *sk) 1140 { 1141 if (!sk->sk_prot->enter_memory_pressure) 1142 return; 1143 1144 sk->sk_prot->enter_memory_pressure(sk); 1145 } 1146 1147 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1148 { 1149 return sk->sk_prot->sysctl_mem[index]; 1150 } 1151 1152 static inline long 1153 sk_memory_allocated(const struct sock *sk) 1154 { 1155 return atomic_long_read(sk->sk_prot->memory_allocated); 1156 } 1157 1158 static inline long 1159 sk_memory_allocated_add(struct sock *sk, int amt) 1160 { 1161 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated); 1162 } 1163 1164 static inline void 1165 sk_memory_allocated_sub(struct sock *sk, int amt) 1166 { 1167 atomic_long_sub(amt, sk->sk_prot->memory_allocated); 1168 } 1169 1170 static inline void sk_sockets_allocated_dec(struct sock *sk) 1171 { 1172 percpu_counter_dec(sk->sk_prot->sockets_allocated); 1173 } 1174 1175 static inline void sk_sockets_allocated_inc(struct sock *sk) 1176 { 1177 percpu_counter_inc(sk->sk_prot->sockets_allocated); 1178 } 1179 1180 static inline int 1181 sk_sockets_allocated_read_positive(struct sock *sk) 1182 { 1183 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated); 1184 } 1185 1186 static inline int 1187 proto_sockets_allocated_sum_positive(struct proto *prot) 1188 { 1189 return percpu_counter_sum_positive(prot->sockets_allocated); 1190 } 1191 1192 static inline long 1193 proto_memory_allocated(struct proto *prot) 1194 { 1195 return atomic_long_read(prot->memory_allocated); 1196 } 1197 1198 static inline bool 1199 proto_memory_pressure(struct proto *prot) 1200 { 1201 if (!prot->memory_pressure) 1202 return false; 1203 return !!*prot->memory_pressure; 1204 } 1205 1206 1207 #ifdef CONFIG_PROC_FS 1208 /* Called with local bh disabled */ 1209 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1210 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1211 #else 1212 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1213 int inc) 1214 { 1215 } 1216 #endif 1217 1218 1219 /* With per-bucket locks this operation is not-atomic, so that 1220 * this version is not worse. 1221 */ 1222 static inline int __sk_prot_rehash(struct sock *sk) 1223 { 1224 sk->sk_prot->unhash(sk); 1225 return sk->sk_prot->hash(sk); 1226 } 1227 1228 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 1229 1230 /* About 10 seconds */ 1231 #define SOCK_DESTROY_TIME (10*HZ) 1232 1233 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1234 #define PROT_SOCK 1024 1235 1236 #define SHUTDOWN_MASK 3 1237 #define RCV_SHUTDOWN 1 1238 #define SEND_SHUTDOWN 2 1239 1240 #define SOCK_SNDBUF_LOCK 1 1241 #define SOCK_RCVBUF_LOCK 2 1242 #define SOCK_BINDADDR_LOCK 4 1243 #define SOCK_BINDPORT_LOCK 8 1244 1245 struct socket_alloc { 1246 struct socket socket; 1247 struct inode vfs_inode; 1248 }; 1249 1250 static inline struct socket *SOCKET_I(struct inode *inode) 1251 { 1252 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1253 } 1254 1255 static inline struct inode *SOCK_INODE(struct socket *socket) 1256 { 1257 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1258 } 1259 1260 /* 1261 * Functions for memory accounting 1262 */ 1263 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1264 void __sk_mem_reclaim(struct sock *sk, int amount); 1265 1266 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 1267 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1268 #define SK_MEM_SEND 0 1269 #define SK_MEM_RECV 1 1270 1271 static inline int sk_mem_pages(int amt) 1272 { 1273 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1274 } 1275 1276 static inline bool sk_has_account(struct sock *sk) 1277 { 1278 /* return true if protocol supports memory accounting */ 1279 return !!sk->sk_prot->memory_allocated; 1280 } 1281 1282 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1283 { 1284 if (!sk_has_account(sk)) 1285 return true; 1286 return size <= sk->sk_forward_alloc || 1287 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1288 } 1289 1290 static inline bool 1291 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1292 { 1293 if (!sk_has_account(sk)) 1294 return true; 1295 return size<= sk->sk_forward_alloc || 1296 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1297 skb_pfmemalloc(skb); 1298 } 1299 1300 static inline void sk_mem_reclaim(struct sock *sk) 1301 { 1302 if (!sk_has_account(sk)) 1303 return; 1304 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1305 __sk_mem_reclaim(sk, sk->sk_forward_alloc); 1306 } 1307 1308 static inline void sk_mem_reclaim_partial(struct sock *sk) 1309 { 1310 if (!sk_has_account(sk)) 1311 return; 1312 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1313 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); 1314 } 1315 1316 static inline void sk_mem_charge(struct sock *sk, int size) 1317 { 1318 if (!sk_has_account(sk)) 1319 return; 1320 sk->sk_forward_alloc -= size; 1321 } 1322 1323 static inline void sk_mem_uncharge(struct sock *sk, int size) 1324 { 1325 if (!sk_has_account(sk)) 1326 return; 1327 sk->sk_forward_alloc += size; 1328 } 1329 1330 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1331 { 1332 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1333 sk->sk_wmem_queued -= skb->truesize; 1334 sk_mem_uncharge(sk, skb->truesize); 1335 __kfree_skb(skb); 1336 } 1337 1338 static inline void sock_release_ownership(struct sock *sk) 1339 { 1340 if (sk->sk_lock.owned) { 1341 sk->sk_lock.owned = 0; 1342 1343 /* The sk_lock has mutex_unlock() semantics: */ 1344 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_); 1345 } 1346 } 1347 1348 /* 1349 * Macro so as to not evaluate some arguments when 1350 * lockdep is not enabled. 1351 * 1352 * Mark both the sk_lock and the sk_lock.slock as a 1353 * per-address-family lock class. 1354 */ 1355 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1356 do { \ 1357 sk->sk_lock.owned = 0; \ 1358 init_waitqueue_head(&sk->sk_lock.wq); \ 1359 spin_lock_init(&(sk)->sk_lock.slock); \ 1360 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1361 sizeof((sk)->sk_lock)); \ 1362 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1363 (skey), (sname)); \ 1364 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1365 } while (0) 1366 1367 #ifdef CONFIG_LOCKDEP 1368 static inline bool lockdep_sock_is_held(const struct sock *csk) 1369 { 1370 struct sock *sk = (struct sock *)csk; 1371 1372 return lockdep_is_held(&sk->sk_lock) || 1373 lockdep_is_held(&sk->sk_lock.slock); 1374 } 1375 #endif 1376 1377 void lock_sock_nested(struct sock *sk, int subclass); 1378 1379 static inline void lock_sock(struct sock *sk) 1380 { 1381 lock_sock_nested(sk, 0); 1382 } 1383 1384 void release_sock(struct sock *sk); 1385 1386 /* BH context may only use the following locking interface. */ 1387 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1388 #define bh_lock_sock_nested(__sk) \ 1389 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1390 SINGLE_DEPTH_NESTING) 1391 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1392 1393 bool lock_sock_fast(struct sock *sk); 1394 /** 1395 * unlock_sock_fast - complement of lock_sock_fast 1396 * @sk: socket 1397 * @slow: slow mode 1398 * 1399 * fast unlock socket for user context. 1400 * If slow mode is on, we call regular release_sock() 1401 */ 1402 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1403 { 1404 if (slow) 1405 release_sock(sk); 1406 else 1407 spin_unlock_bh(&sk->sk_lock.slock); 1408 } 1409 1410 /* Used by processes to "lock" a socket state, so that 1411 * interrupts and bottom half handlers won't change it 1412 * from under us. It essentially blocks any incoming 1413 * packets, so that we won't get any new data or any 1414 * packets that change the state of the socket. 1415 * 1416 * While locked, BH processing will add new packets to 1417 * the backlog queue. This queue is processed by the 1418 * owner of the socket lock right before it is released. 1419 * 1420 * Since ~2.3.5 it is also exclusive sleep lock serializing 1421 * accesses from user process context. 1422 */ 1423 1424 static inline void sock_owned_by_me(const struct sock *sk) 1425 { 1426 #ifdef CONFIG_LOCKDEP 1427 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks); 1428 #endif 1429 } 1430 1431 static inline bool sock_owned_by_user(const struct sock *sk) 1432 { 1433 sock_owned_by_me(sk); 1434 return sk->sk_lock.owned; 1435 } 1436 1437 /* no reclassification while locks are held */ 1438 static inline bool sock_allow_reclassification(const struct sock *csk) 1439 { 1440 struct sock *sk = (struct sock *)csk; 1441 1442 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock); 1443 } 1444 1445 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1446 struct proto *prot, int kern); 1447 void sk_free(struct sock *sk); 1448 void sk_destruct(struct sock *sk); 1449 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1450 1451 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1452 gfp_t priority); 1453 void __sock_wfree(struct sk_buff *skb); 1454 void sock_wfree(struct sk_buff *skb); 1455 void skb_orphan_partial(struct sk_buff *skb); 1456 void sock_rfree(struct sk_buff *skb); 1457 void sock_efree(struct sk_buff *skb); 1458 #ifdef CONFIG_INET 1459 void sock_edemux(struct sk_buff *skb); 1460 #else 1461 #define sock_edemux(skb) sock_efree(skb) 1462 #endif 1463 1464 int sock_setsockopt(struct socket *sock, int level, int op, 1465 char __user *optval, unsigned int optlen); 1466 1467 int sock_getsockopt(struct socket *sock, int level, int op, 1468 char __user *optval, int __user *optlen); 1469 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1470 int noblock, int *errcode); 1471 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1472 unsigned long data_len, int noblock, 1473 int *errcode, int max_page_order); 1474 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1475 void sock_kfree_s(struct sock *sk, void *mem, int size); 1476 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1477 void sk_send_sigurg(struct sock *sk); 1478 1479 struct sockcm_cookie { 1480 u32 mark; 1481 u16 tsflags; 1482 }; 1483 1484 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg, 1485 struct sockcm_cookie *sockc); 1486 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1487 struct sockcm_cookie *sockc); 1488 1489 /* 1490 * Functions to fill in entries in struct proto_ops when a protocol 1491 * does not implement a particular function. 1492 */ 1493 int sock_no_bind(struct socket *, struct sockaddr *, int); 1494 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1495 int sock_no_socketpair(struct socket *, struct socket *); 1496 int sock_no_accept(struct socket *, struct socket *, int); 1497 int sock_no_getname(struct socket *, struct sockaddr *, int *, int); 1498 unsigned int sock_no_poll(struct file *, struct socket *, 1499 struct poll_table_struct *); 1500 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1501 int sock_no_listen(struct socket *, int); 1502 int sock_no_shutdown(struct socket *, int); 1503 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *); 1504 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int); 1505 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1506 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1507 int sock_no_mmap(struct file *file, struct socket *sock, 1508 struct vm_area_struct *vma); 1509 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1510 size_t size, int flags); 1511 1512 /* 1513 * Functions to fill in entries in struct proto_ops when a protocol 1514 * uses the inet style. 1515 */ 1516 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1517 char __user *optval, int __user *optlen); 1518 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1519 int flags); 1520 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1521 char __user *optval, unsigned int optlen); 1522 int compat_sock_common_getsockopt(struct socket *sock, int level, 1523 int optname, char __user *optval, int __user *optlen); 1524 int compat_sock_common_setsockopt(struct socket *sock, int level, 1525 int optname, char __user *optval, unsigned int optlen); 1526 1527 void sk_common_release(struct sock *sk); 1528 1529 /* 1530 * Default socket callbacks and setup code 1531 */ 1532 1533 /* Initialise core socket variables */ 1534 void sock_init_data(struct socket *sock, struct sock *sk); 1535 1536 /* 1537 * Socket reference counting postulates. 1538 * 1539 * * Each user of socket SHOULD hold a reference count. 1540 * * Each access point to socket (an hash table bucket, reference from a list, 1541 * running timer, skb in flight MUST hold a reference count. 1542 * * When reference count hits 0, it means it will never increase back. 1543 * * When reference count hits 0, it means that no references from 1544 * outside exist to this socket and current process on current CPU 1545 * is last user and may/should destroy this socket. 1546 * * sk_free is called from any context: process, BH, IRQ. When 1547 * it is called, socket has no references from outside -> sk_free 1548 * may release descendant resources allocated by the socket, but 1549 * to the time when it is called, socket is NOT referenced by any 1550 * hash tables, lists etc. 1551 * * Packets, delivered from outside (from network or from another process) 1552 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1553 * when they sit in queue. Otherwise, packets will leak to hole, when 1554 * socket is looked up by one cpu and unhasing is made by another CPU. 1555 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1556 * (leak to backlog). Packet socket does all the processing inside 1557 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1558 * use separate SMP lock, so that they are prone too. 1559 */ 1560 1561 /* Ungrab socket and destroy it, if it was the last reference. */ 1562 static inline void sock_put(struct sock *sk) 1563 { 1564 if (atomic_dec_and_test(&sk->sk_refcnt)) 1565 sk_free(sk); 1566 } 1567 /* Generic version of sock_put(), dealing with all sockets 1568 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1569 */ 1570 void sock_gen_put(struct sock *sk); 1571 1572 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested); 1573 1574 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1575 { 1576 sk->sk_tx_queue_mapping = tx_queue; 1577 } 1578 1579 static inline void sk_tx_queue_clear(struct sock *sk) 1580 { 1581 sk->sk_tx_queue_mapping = -1; 1582 } 1583 1584 static inline int sk_tx_queue_get(const struct sock *sk) 1585 { 1586 return sk ? sk->sk_tx_queue_mapping : -1; 1587 } 1588 1589 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1590 { 1591 sk_tx_queue_clear(sk); 1592 sk->sk_socket = sock; 1593 } 1594 1595 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1596 { 1597 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1598 return &rcu_dereference_raw(sk->sk_wq)->wait; 1599 } 1600 /* Detach socket from process context. 1601 * Announce socket dead, detach it from wait queue and inode. 1602 * Note that parent inode held reference count on this struct sock, 1603 * we do not release it in this function, because protocol 1604 * probably wants some additional cleanups or even continuing 1605 * to work with this socket (TCP). 1606 */ 1607 static inline void sock_orphan(struct sock *sk) 1608 { 1609 write_lock_bh(&sk->sk_callback_lock); 1610 sock_set_flag(sk, SOCK_DEAD); 1611 sk_set_socket(sk, NULL); 1612 sk->sk_wq = NULL; 1613 write_unlock_bh(&sk->sk_callback_lock); 1614 } 1615 1616 static inline void sock_graft(struct sock *sk, struct socket *parent) 1617 { 1618 write_lock_bh(&sk->sk_callback_lock); 1619 sk->sk_wq = parent->wq; 1620 parent->sk = sk; 1621 sk_set_socket(sk, parent); 1622 security_sock_graft(sk, parent); 1623 write_unlock_bh(&sk->sk_callback_lock); 1624 } 1625 1626 kuid_t sock_i_uid(struct sock *sk); 1627 unsigned long sock_i_ino(struct sock *sk); 1628 1629 static inline u32 net_tx_rndhash(void) 1630 { 1631 u32 v = prandom_u32(); 1632 1633 return v ?: 1; 1634 } 1635 1636 static inline void sk_set_txhash(struct sock *sk) 1637 { 1638 sk->sk_txhash = net_tx_rndhash(); 1639 } 1640 1641 static inline void sk_rethink_txhash(struct sock *sk) 1642 { 1643 if (sk->sk_txhash) 1644 sk_set_txhash(sk); 1645 } 1646 1647 static inline struct dst_entry * 1648 __sk_dst_get(struct sock *sk) 1649 { 1650 return rcu_dereference_check(sk->sk_dst_cache, 1651 lockdep_sock_is_held(sk)); 1652 } 1653 1654 static inline struct dst_entry * 1655 sk_dst_get(struct sock *sk) 1656 { 1657 struct dst_entry *dst; 1658 1659 rcu_read_lock(); 1660 dst = rcu_dereference(sk->sk_dst_cache); 1661 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 1662 dst = NULL; 1663 rcu_read_unlock(); 1664 return dst; 1665 } 1666 1667 static inline void dst_negative_advice(struct sock *sk) 1668 { 1669 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1670 1671 sk_rethink_txhash(sk); 1672 1673 if (dst && dst->ops->negative_advice) { 1674 ndst = dst->ops->negative_advice(dst); 1675 1676 if (ndst != dst) { 1677 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1678 sk_tx_queue_clear(sk); 1679 } 1680 } 1681 } 1682 1683 static inline void 1684 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1685 { 1686 struct dst_entry *old_dst; 1687 1688 sk_tx_queue_clear(sk); 1689 /* 1690 * This can be called while sk is owned by the caller only, 1691 * with no state that can be checked in a rcu_dereference_check() cond 1692 */ 1693 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1694 rcu_assign_pointer(sk->sk_dst_cache, dst); 1695 dst_release(old_dst); 1696 } 1697 1698 static inline void 1699 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1700 { 1701 struct dst_entry *old_dst; 1702 1703 sk_tx_queue_clear(sk); 1704 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 1705 dst_release(old_dst); 1706 } 1707 1708 static inline void 1709 __sk_dst_reset(struct sock *sk) 1710 { 1711 __sk_dst_set(sk, NULL); 1712 } 1713 1714 static inline void 1715 sk_dst_reset(struct sock *sk) 1716 { 1717 sk_dst_set(sk, NULL); 1718 } 1719 1720 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1721 1722 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1723 1724 bool sk_mc_loop(struct sock *sk); 1725 1726 static inline bool sk_can_gso(const struct sock *sk) 1727 { 1728 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1729 } 1730 1731 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1732 1733 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1734 { 1735 sk->sk_route_nocaps |= flags; 1736 sk->sk_route_caps &= ~flags; 1737 } 1738 1739 static inline bool sk_check_csum_caps(struct sock *sk) 1740 { 1741 return (sk->sk_route_caps & NETIF_F_HW_CSUM) || 1742 (sk->sk_family == PF_INET && 1743 (sk->sk_route_caps & NETIF_F_IP_CSUM)) || 1744 (sk->sk_family == PF_INET6 && 1745 (sk->sk_route_caps & NETIF_F_IPV6_CSUM)); 1746 } 1747 1748 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1749 struct iov_iter *from, char *to, 1750 int copy, int offset) 1751 { 1752 if (skb->ip_summed == CHECKSUM_NONE) { 1753 __wsum csum = 0; 1754 if (csum_and_copy_from_iter(to, copy, &csum, from) != copy) 1755 return -EFAULT; 1756 skb->csum = csum_block_add(skb->csum, csum, offset); 1757 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1758 if (copy_from_iter_nocache(to, copy, from) != copy) 1759 return -EFAULT; 1760 } else if (copy_from_iter(to, copy, from) != copy) 1761 return -EFAULT; 1762 1763 return 0; 1764 } 1765 1766 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1767 struct iov_iter *from, int copy) 1768 { 1769 int err, offset = skb->len; 1770 1771 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1772 copy, offset); 1773 if (err) 1774 __skb_trim(skb, offset); 1775 1776 return err; 1777 } 1778 1779 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 1780 struct sk_buff *skb, 1781 struct page *page, 1782 int off, int copy) 1783 { 1784 int err; 1785 1786 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1787 copy, skb->len); 1788 if (err) 1789 return err; 1790 1791 skb->len += copy; 1792 skb->data_len += copy; 1793 skb->truesize += copy; 1794 sk->sk_wmem_queued += copy; 1795 sk_mem_charge(sk, copy); 1796 return 0; 1797 } 1798 1799 /** 1800 * sk_wmem_alloc_get - returns write allocations 1801 * @sk: socket 1802 * 1803 * Returns sk_wmem_alloc minus initial offset of one 1804 */ 1805 static inline int sk_wmem_alloc_get(const struct sock *sk) 1806 { 1807 return atomic_read(&sk->sk_wmem_alloc) - 1; 1808 } 1809 1810 /** 1811 * sk_rmem_alloc_get - returns read allocations 1812 * @sk: socket 1813 * 1814 * Returns sk_rmem_alloc 1815 */ 1816 static inline int sk_rmem_alloc_get(const struct sock *sk) 1817 { 1818 return atomic_read(&sk->sk_rmem_alloc); 1819 } 1820 1821 /** 1822 * sk_has_allocations - check if allocations are outstanding 1823 * @sk: socket 1824 * 1825 * Returns true if socket has write or read allocations 1826 */ 1827 static inline bool sk_has_allocations(const struct sock *sk) 1828 { 1829 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1830 } 1831 1832 /** 1833 * skwq_has_sleeper - check if there are any waiting processes 1834 * @wq: struct socket_wq 1835 * 1836 * Returns true if socket_wq has waiting processes 1837 * 1838 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory 1839 * barrier call. They were added due to the race found within the tcp code. 1840 * 1841 * Consider following tcp code paths: 1842 * 1843 * CPU1 CPU2 1844 * 1845 * sys_select receive packet 1846 * ... ... 1847 * __add_wait_queue update tp->rcv_nxt 1848 * ... ... 1849 * tp->rcv_nxt check sock_def_readable 1850 * ... { 1851 * schedule rcu_read_lock(); 1852 * wq = rcu_dereference(sk->sk_wq); 1853 * if (wq && waitqueue_active(&wq->wait)) 1854 * wake_up_interruptible(&wq->wait) 1855 * ... 1856 * } 1857 * 1858 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1859 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1860 * could then endup calling schedule and sleep forever if there are no more 1861 * data on the socket. 1862 * 1863 */ 1864 static inline bool skwq_has_sleeper(struct socket_wq *wq) 1865 { 1866 return wq && wq_has_sleeper(&wq->wait); 1867 } 1868 1869 /** 1870 * sock_poll_wait - place memory barrier behind the poll_wait call. 1871 * @filp: file 1872 * @wait_address: socket wait queue 1873 * @p: poll_table 1874 * 1875 * See the comments in the wq_has_sleeper function. 1876 */ 1877 static inline void sock_poll_wait(struct file *filp, 1878 wait_queue_head_t *wait_address, poll_table *p) 1879 { 1880 if (!poll_does_not_wait(p) && wait_address) { 1881 poll_wait(filp, wait_address, p); 1882 /* We need to be sure we are in sync with the 1883 * socket flags modification. 1884 * 1885 * This memory barrier is paired in the wq_has_sleeper. 1886 */ 1887 smp_mb(); 1888 } 1889 } 1890 1891 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 1892 { 1893 if (sk->sk_txhash) { 1894 skb->l4_hash = 1; 1895 skb->hash = sk->sk_txhash; 1896 } 1897 } 1898 1899 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 1900 1901 /* 1902 * Queue a received datagram if it will fit. Stream and sequenced 1903 * protocols can't normally use this as they need to fit buffers in 1904 * and play with them. 1905 * 1906 * Inlined as it's very short and called for pretty much every 1907 * packet ever received. 1908 */ 1909 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1910 { 1911 skb_orphan(skb); 1912 skb->sk = sk; 1913 skb->destructor = sock_rfree; 1914 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1915 sk_mem_charge(sk, skb->truesize); 1916 } 1917 1918 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 1919 unsigned long expires); 1920 1921 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 1922 1923 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1924 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1925 1926 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 1927 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 1928 1929 /* 1930 * Recover an error report and clear atomically 1931 */ 1932 1933 static inline int sock_error(struct sock *sk) 1934 { 1935 int err; 1936 if (likely(!sk->sk_err)) 1937 return 0; 1938 err = xchg(&sk->sk_err, 0); 1939 return -err; 1940 } 1941 1942 static inline unsigned long sock_wspace(struct sock *sk) 1943 { 1944 int amt = 0; 1945 1946 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 1947 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 1948 if (amt < 0) 1949 amt = 0; 1950 } 1951 return amt; 1952 } 1953 1954 /* Note: 1955 * We use sk->sk_wq_raw, from contexts knowing this 1956 * pointer is not NULL and cannot disappear/change. 1957 */ 1958 static inline void sk_set_bit(int nr, struct sock *sk) 1959 { 1960 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 1961 !sock_flag(sk, SOCK_FASYNC)) 1962 return; 1963 1964 set_bit(nr, &sk->sk_wq_raw->flags); 1965 } 1966 1967 static inline void sk_clear_bit(int nr, struct sock *sk) 1968 { 1969 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 1970 !sock_flag(sk, SOCK_FASYNC)) 1971 return; 1972 1973 clear_bit(nr, &sk->sk_wq_raw->flags); 1974 } 1975 1976 static inline void sk_wake_async(const struct sock *sk, int how, int band) 1977 { 1978 if (sock_flag(sk, SOCK_FASYNC)) { 1979 rcu_read_lock(); 1980 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 1981 rcu_read_unlock(); 1982 } 1983 } 1984 1985 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 1986 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 1987 * Note: for send buffers, TCP works better if we can build two skbs at 1988 * minimum. 1989 */ 1990 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 1991 1992 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 1993 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 1994 1995 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 1996 { 1997 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 1998 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 1999 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); 2000 } 2001 } 2002 2003 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 2004 bool force_schedule); 2005 2006 /** 2007 * sk_page_frag - return an appropriate page_frag 2008 * @sk: socket 2009 * 2010 * If socket allocation mode allows current thread to sleep, it means its 2011 * safe to use the per task page_frag instead of the per socket one. 2012 */ 2013 static inline struct page_frag *sk_page_frag(struct sock *sk) 2014 { 2015 if (gfpflags_allow_blocking(sk->sk_allocation)) 2016 return ¤t->task_frag; 2017 2018 return &sk->sk_frag; 2019 } 2020 2021 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2022 2023 /* 2024 * Default write policy as shown to user space via poll/select/SIGIO 2025 */ 2026 static inline bool sock_writeable(const struct sock *sk) 2027 { 2028 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 2029 } 2030 2031 static inline gfp_t gfp_any(void) 2032 { 2033 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2034 } 2035 2036 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2037 { 2038 return noblock ? 0 : sk->sk_rcvtimeo; 2039 } 2040 2041 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2042 { 2043 return noblock ? 0 : sk->sk_sndtimeo; 2044 } 2045 2046 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2047 { 2048 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 2049 } 2050 2051 /* Alas, with timeout socket operations are not restartable. 2052 * Compare this to poll(). 2053 */ 2054 static inline int sock_intr_errno(long timeo) 2055 { 2056 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2057 } 2058 2059 struct sock_skb_cb { 2060 u32 dropcount; 2061 }; 2062 2063 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2064 * using skb->cb[] would keep using it directly and utilize its 2065 * alignement guarantee. 2066 */ 2067 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \ 2068 sizeof(struct sock_skb_cb))) 2069 2070 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2071 SOCK_SKB_CB_OFFSET)) 2072 2073 #define sock_skb_cb_check_size(size) \ 2074 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2075 2076 static inline void 2077 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2078 { 2079 SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops); 2080 } 2081 2082 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) 2083 { 2084 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2085 2086 atomic_add(segs, &sk->sk_drops); 2087 } 2088 2089 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2090 struct sk_buff *skb); 2091 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2092 struct sk_buff *skb); 2093 2094 static inline void 2095 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2096 { 2097 ktime_t kt = skb->tstamp; 2098 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2099 2100 /* 2101 * generate control messages if 2102 * - receive time stamping in software requested 2103 * - software time stamp available and wanted 2104 * - hardware time stamps available and wanted 2105 */ 2106 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2107 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2108 (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2109 (hwtstamps->hwtstamp.tv64 && 2110 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2111 __sock_recv_timestamp(msg, sk, skb); 2112 else 2113 sk->sk_stamp = kt; 2114 2115 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2116 __sock_recv_wifi_status(msg, sk, skb); 2117 } 2118 2119 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2120 struct sk_buff *skb); 2121 2122 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2123 struct sk_buff *skb) 2124 { 2125 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2126 (1UL << SOCK_RCVTSTAMP)) 2127 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2128 SOF_TIMESTAMPING_RAW_HARDWARE) 2129 2130 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2131 __sock_recv_ts_and_drops(msg, sk, skb); 2132 else 2133 sk->sk_stamp = skb->tstamp; 2134 } 2135 2136 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); 2137 2138 /** 2139 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2140 * @sk: socket sending this packet 2141 * @tsflags: timestamping flags to use 2142 * @tx_flags: completed with instructions for time stamping 2143 * 2144 * Note : callers should take care of initial *tx_flags value (usually 0) 2145 */ 2146 static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags, 2147 __u8 *tx_flags) 2148 { 2149 if (unlikely(tsflags)) 2150 __sock_tx_timestamp(tsflags, tx_flags); 2151 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2152 *tx_flags |= SKBTX_WIFI_STATUS; 2153 } 2154 2155 /** 2156 * sk_eat_skb - Release a skb if it is no longer needed 2157 * @sk: socket to eat this skb from 2158 * @skb: socket buffer to eat 2159 * 2160 * This routine must be called with interrupts disabled or with the socket 2161 * locked so that the sk_buff queue operation is ok. 2162 */ 2163 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2164 { 2165 __skb_unlink(skb, &sk->sk_receive_queue); 2166 __kfree_skb(skb); 2167 } 2168 2169 static inline 2170 struct net *sock_net(const struct sock *sk) 2171 { 2172 return read_pnet(&sk->sk_net); 2173 } 2174 2175 static inline 2176 void sock_net_set(struct sock *sk, struct net *net) 2177 { 2178 write_pnet(&sk->sk_net, net); 2179 } 2180 2181 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2182 { 2183 if (skb->sk) { 2184 struct sock *sk = skb->sk; 2185 2186 skb->destructor = NULL; 2187 skb->sk = NULL; 2188 return sk; 2189 } 2190 return NULL; 2191 } 2192 2193 /* This helper checks if a socket is a full socket, 2194 * ie _not_ a timewait or request socket. 2195 */ 2196 static inline bool sk_fullsock(const struct sock *sk) 2197 { 2198 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2199 } 2200 2201 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2202 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2203 */ 2204 static inline bool sk_listener(const struct sock *sk) 2205 { 2206 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2207 } 2208 2209 /** 2210 * sk_state_load - read sk->sk_state for lockless contexts 2211 * @sk: socket pointer 2212 * 2213 * Paired with sk_state_store(). Used in places we do not hold socket lock : 2214 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... 2215 */ 2216 static inline int sk_state_load(const struct sock *sk) 2217 { 2218 return smp_load_acquire(&sk->sk_state); 2219 } 2220 2221 /** 2222 * sk_state_store - update sk->sk_state 2223 * @sk: socket pointer 2224 * @newstate: new state 2225 * 2226 * Paired with sk_state_load(). Should be used in contexts where 2227 * state change might impact lockless readers. 2228 */ 2229 static inline void sk_state_store(struct sock *sk, int newstate) 2230 { 2231 smp_store_release(&sk->sk_state, newstate); 2232 } 2233 2234 void sock_enable_timestamp(struct sock *sk, int flag); 2235 int sock_get_timestamp(struct sock *, struct timeval __user *); 2236 int sock_get_timestampns(struct sock *, struct timespec __user *); 2237 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2238 int type); 2239 2240 bool sk_ns_capable(const struct sock *sk, 2241 struct user_namespace *user_ns, int cap); 2242 bool sk_capable(const struct sock *sk, int cap); 2243 bool sk_net_capable(const struct sock *sk, int cap); 2244 2245 extern __u32 sysctl_wmem_max; 2246 extern __u32 sysctl_rmem_max; 2247 2248 extern int sysctl_tstamp_allow_data; 2249 extern int sysctl_optmem_max; 2250 2251 extern __u32 sysctl_wmem_default; 2252 extern __u32 sysctl_rmem_default; 2253 2254 #endif /* _SOCK_H */ 2255