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