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_nulls_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 }; 442 443 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) 444 445 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) 446 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) 447 448 /* 449 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 450 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 451 * on a socket means that the socket will reuse everybody else's port 452 * without looking at the other's sk_reuse value. 453 */ 454 455 #define SK_NO_REUSE 0 456 #define SK_CAN_REUSE 1 457 #define SK_FORCE_REUSE 2 458 459 static inline int sk_peek_offset(struct sock *sk, int flags) 460 { 461 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0)) 462 return sk->sk_peek_off; 463 else 464 return 0; 465 } 466 467 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 468 { 469 if (sk->sk_peek_off >= 0) { 470 if (sk->sk_peek_off >= val) 471 sk->sk_peek_off -= val; 472 else 473 sk->sk_peek_off = 0; 474 } 475 } 476 477 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 478 { 479 if (sk->sk_peek_off >= 0) 480 sk->sk_peek_off += val; 481 } 482 483 /* 484 * Hashed lists helper routines 485 */ 486 static inline struct sock *sk_entry(const struct hlist_node *node) 487 { 488 return hlist_entry(node, struct sock, sk_node); 489 } 490 491 static inline struct sock *__sk_head(const struct hlist_head *head) 492 { 493 return hlist_entry(head->first, struct sock, sk_node); 494 } 495 496 static inline struct sock *sk_head(const struct hlist_head *head) 497 { 498 return hlist_empty(head) ? NULL : __sk_head(head); 499 } 500 501 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 502 { 503 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 504 } 505 506 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 507 { 508 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 509 } 510 511 static inline struct sock *sk_next(const struct sock *sk) 512 { 513 return sk->sk_node.next ? 514 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; 515 } 516 517 static inline struct sock *sk_nulls_next(const struct sock *sk) 518 { 519 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 520 hlist_nulls_entry(sk->sk_nulls_node.next, 521 struct sock, sk_nulls_node) : 522 NULL; 523 } 524 525 static inline bool sk_unhashed(const struct sock *sk) 526 { 527 return hlist_unhashed(&sk->sk_node); 528 } 529 530 static inline bool sk_hashed(const struct sock *sk) 531 { 532 return !sk_unhashed(sk); 533 } 534 535 static inline void sk_node_init(struct hlist_node *node) 536 { 537 node->pprev = NULL; 538 } 539 540 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 541 { 542 node->pprev = NULL; 543 } 544 545 static inline void __sk_del_node(struct sock *sk) 546 { 547 __hlist_del(&sk->sk_node); 548 } 549 550 /* NB: equivalent to hlist_del_init_rcu */ 551 static inline bool __sk_del_node_init(struct sock *sk) 552 { 553 if (sk_hashed(sk)) { 554 __sk_del_node(sk); 555 sk_node_init(&sk->sk_node); 556 return true; 557 } 558 return false; 559 } 560 561 /* Grab socket reference count. This operation is valid only 562 when sk is ALREADY grabbed f.e. it is found in hash table 563 or a list and the lookup is made under lock preventing hash table 564 modifications. 565 */ 566 567 static inline void sock_hold(struct sock *sk) 568 { 569 atomic_inc(&sk->sk_refcnt); 570 } 571 572 /* Ungrab socket in the context, which assumes that socket refcnt 573 cannot hit zero, f.e. it is true in context of any socketcall. 574 */ 575 static inline void __sock_put(struct sock *sk) 576 { 577 atomic_dec(&sk->sk_refcnt); 578 } 579 580 static inline bool sk_del_node_init(struct sock *sk) 581 { 582 bool rc = __sk_del_node_init(sk); 583 584 if (rc) { 585 /* paranoid for a while -acme */ 586 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 587 __sock_put(sk); 588 } 589 return rc; 590 } 591 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 592 593 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 594 { 595 if (sk_hashed(sk)) { 596 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 597 return true; 598 } 599 return false; 600 } 601 602 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 603 { 604 bool rc = __sk_nulls_del_node_init_rcu(sk); 605 606 if (rc) { 607 /* paranoid for a while -acme */ 608 WARN_ON(atomic_read(&sk->sk_refcnt) == 1); 609 __sock_put(sk); 610 } 611 return rc; 612 } 613 614 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 615 { 616 hlist_add_head(&sk->sk_node, list); 617 } 618 619 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 620 { 621 sock_hold(sk); 622 __sk_add_node(sk, list); 623 } 624 625 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 626 { 627 sock_hold(sk); 628 hlist_add_head_rcu(&sk->sk_node, list); 629 } 630 631 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 632 { 633 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 634 } 635 636 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 637 { 638 sock_hold(sk); 639 __sk_nulls_add_node_rcu(sk, list); 640 } 641 642 static inline void __sk_del_bind_node(struct sock *sk) 643 { 644 __hlist_del(&sk->sk_bind_node); 645 } 646 647 static inline void sk_add_bind_node(struct sock *sk, 648 struct hlist_head *list) 649 { 650 hlist_add_head(&sk->sk_bind_node, list); 651 } 652 653 #define sk_for_each(__sk, list) \ 654 hlist_for_each_entry(__sk, list, sk_node) 655 #define sk_for_each_rcu(__sk, list) \ 656 hlist_for_each_entry_rcu(__sk, list, sk_node) 657 #define sk_nulls_for_each(__sk, node, list) \ 658 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 659 #define sk_nulls_for_each_rcu(__sk, node, list) \ 660 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 661 #define sk_for_each_from(__sk) \ 662 hlist_for_each_entry_from(__sk, sk_node) 663 #define sk_nulls_for_each_from(__sk, node) \ 664 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 665 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 666 #define sk_for_each_safe(__sk, tmp, list) \ 667 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 668 #define sk_for_each_bound(__sk, list) \ 669 hlist_for_each_entry(__sk, list, sk_bind_node) 670 671 /** 672 * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset 673 * @tpos: the type * to use as a loop cursor. 674 * @pos: the &struct hlist_node to use as a loop cursor. 675 * @head: the head for your list. 676 * @offset: offset of hlist_node within the struct. 677 * 678 */ 679 #define sk_nulls_for_each_entry_offset(tpos, pos, head, offset) \ 680 for (pos = (head)->first; \ 681 (!is_a_nulls(pos)) && \ 682 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 683 pos = pos->next) 684 685 static inline struct user_namespace *sk_user_ns(struct sock *sk) 686 { 687 /* Careful only use this in a context where these parameters 688 * can not change and must all be valid, such as recvmsg from 689 * userspace. 690 */ 691 return sk->sk_socket->file->f_cred->user_ns; 692 } 693 694 /* Sock flags */ 695 enum sock_flags { 696 SOCK_DEAD, 697 SOCK_DONE, 698 SOCK_URGINLINE, 699 SOCK_KEEPOPEN, 700 SOCK_LINGER, 701 SOCK_DESTROY, 702 SOCK_BROADCAST, 703 SOCK_TIMESTAMP, 704 SOCK_ZAPPED, 705 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 706 SOCK_DBG, /* %SO_DEBUG setting */ 707 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 708 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 709 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 710 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 711 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 712 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 713 SOCK_FASYNC, /* fasync() active */ 714 SOCK_RXQ_OVFL, 715 SOCK_ZEROCOPY, /* buffers from userspace */ 716 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 717 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 718 * Will use last 4 bytes of packet sent from 719 * user-space instead. 720 */ 721 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 722 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 723 }; 724 725 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) 726 727 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 728 { 729 nsk->sk_flags = osk->sk_flags; 730 } 731 732 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 733 { 734 __set_bit(flag, &sk->sk_flags); 735 } 736 737 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 738 { 739 __clear_bit(flag, &sk->sk_flags); 740 } 741 742 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 743 { 744 return test_bit(flag, &sk->sk_flags); 745 } 746 747 #ifdef CONFIG_NET 748 extern struct static_key memalloc_socks; 749 static inline int sk_memalloc_socks(void) 750 { 751 return static_key_false(&memalloc_socks); 752 } 753 #else 754 755 static inline int sk_memalloc_socks(void) 756 { 757 return 0; 758 } 759 760 #endif 761 762 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 763 { 764 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC); 765 } 766 767 static inline void sk_acceptq_removed(struct sock *sk) 768 { 769 sk->sk_ack_backlog--; 770 } 771 772 static inline void sk_acceptq_added(struct sock *sk) 773 { 774 sk->sk_ack_backlog++; 775 } 776 777 static inline bool sk_acceptq_is_full(const struct sock *sk) 778 { 779 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 780 } 781 782 /* 783 * Compute minimal free write space needed to queue new packets. 784 */ 785 static inline int sk_stream_min_wspace(const struct sock *sk) 786 { 787 return sk->sk_wmem_queued >> 1; 788 } 789 790 static inline int sk_stream_wspace(const struct sock *sk) 791 { 792 return sk->sk_sndbuf - sk->sk_wmem_queued; 793 } 794 795 void sk_stream_write_space(struct sock *sk); 796 797 /* OOB backlog add */ 798 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 799 { 800 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 801 skb_dst_force_safe(skb); 802 803 if (!sk->sk_backlog.tail) 804 sk->sk_backlog.head = skb; 805 else 806 sk->sk_backlog.tail->next = skb; 807 808 sk->sk_backlog.tail = skb; 809 skb->next = NULL; 810 } 811 812 /* 813 * Take into account size of receive queue and backlog queue 814 * Do not take into account this skb truesize, 815 * to allow even a single big packet to come. 816 */ 817 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 818 { 819 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 820 821 return qsize > limit; 822 } 823 824 /* The per-socket spinlock must be held here. */ 825 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 826 unsigned int limit) 827 { 828 if (sk_rcvqueues_full(sk, limit)) 829 return -ENOBUFS; 830 831 /* 832 * If the skb was allocated from pfmemalloc reserves, only 833 * allow SOCK_MEMALLOC sockets to use it as this socket is 834 * helping free memory 835 */ 836 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 837 return -ENOMEM; 838 839 __sk_add_backlog(sk, skb); 840 sk->sk_backlog.len += skb->truesize; 841 return 0; 842 } 843 844 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 845 846 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 847 { 848 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 849 return __sk_backlog_rcv(sk, skb); 850 851 return sk->sk_backlog_rcv(sk, skb); 852 } 853 854 static inline void sk_incoming_cpu_update(struct sock *sk) 855 { 856 sk->sk_incoming_cpu = raw_smp_processor_id(); 857 } 858 859 static inline void sock_rps_record_flow_hash(__u32 hash) 860 { 861 #ifdef CONFIG_RPS 862 struct rps_sock_flow_table *sock_flow_table; 863 864 rcu_read_lock(); 865 sock_flow_table = rcu_dereference(rps_sock_flow_table); 866 rps_record_sock_flow(sock_flow_table, hash); 867 rcu_read_unlock(); 868 #endif 869 } 870 871 static inline void sock_rps_record_flow(const struct sock *sk) 872 { 873 #ifdef CONFIG_RPS 874 sock_rps_record_flow_hash(sk->sk_rxhash); 875 #endif 876 } 877 878 static inline void sock_rps_save_rxhash(struct sock *sk, 879 const struct sk_buff *skb) 880 { 881 #ifdef CONFIG_RPS 882 if (unlikely(sk->sk_rxhash != skb->hash)) 883 sk->sk_rxhash = skb->hash; 884 #endif 885 } 886 887 static inline void sock_rps_reset_rxhash(struct sock *sk) 888 { 889 #ifdef CONFIG_RPS 890 sk->sk_rxhash = 0; 891 #endif 892 } 893 894 #define sk_wait_event(__sk, __timeo, __condition) \ 895 ({ int __rc; \ 896 release_sock(__sk); \ 897 __rc = __condition; \ 898 if (!__rc) { \ 899 *(__timeo) = schedule_timeout(*(__timeo)); \ 900 } \ 901 sched_annotate_sleep(); \ 902 lock_sock(__sk); \ 903 __rc = __condition; \ 904 __rc; \ 905 }) 906 907 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 908 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 909 void sk_stream_wait_close(struct sock *sk, long timeo_p); 910 int sk_stream_error(struct sock *sk, int flags, int err); 911 void sk_stream_kill_queues(struct sock *sk); 912 void sk_set_memalloc(struct sock *sk); 913 void sk_clear_memalloc(struct sock *sk); 914 915 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 916 917 struct request_sock_ops; 918 struct timewait_sock_ops; 919 struct inet_hashinfo; 920 struct raw_hashinfo; 921 struct module; 922 923 /* 924 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes 925 * un-modified. Special care is taken when initializing object to zero. 926 */ 927 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 928 { 929 if (offsetof(struct sock, sk_node.next) != 0) 930 memset(sk, 0, offsetof(struct sock, sk_node.next)); 931 memset(&sk->sk_node.pprev, 0, 932 size - offsetof(struct sock, sk_node.pprev)); 933 } 934 935 /* Networking protocol blocks we attach to sockets. 936 * socket layer -> transport layer interface 937 */ 938 struct proto { 939 void (*close)(struct sock *sk, 940 long timeout); 941 int (*connect)(struct sock *sk, 942 struct sockaddr *uaddr, 943 int addr_len); 944 int (*disconnect)(struct sock *sk, int flags); 945 946 struct sock * (*accept)(struct sock *sk, int flags, int *err); 947 948 int (*ioctl)(struct sock *sk, int cmd, 949 unsigned long arg); 950 int (*init)(struct sock *sk); 951 void (*destroy)(struct sock *sk); 952 void (*shutdown)(struct sock *sk, int how); 953 int (*setsockopt)(struct sock *sk, int level, 954 int optname, char __user *optval, 955 unsigned int optlen); 956 int (*getsockopt)(struct sock *sk, int level, 957 int optname, char __user *optval, 958 int __user *option); 959 #ifdef CONFIG_COMPAT 960 int (*compat_setsockopt)(struct sock *sk, 961 int level, 962 int optname, char __user *optval, 963 unsigned int optlen); 964 int (*compat_getsockopt)(struct sock *sk, 965 int level, 966 int optname, char __user *optval, 967 int __user *option); 968 int (*compat_ioctl)(struct sock *sk, 969 unsigned int cmd, unsigned long arg); 970 #endif 971 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 972 size_t len); 973 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 974 size_t len, int noblock, int flags, 975 int *addr_len); 976 int (*sendpage)(struct sock *sk, struct page *page, 977 int offset, size_t size, int flags); 978 int (*bind)(struct sock *sk, 979 struct sockaddr *uaddr, int addr_len); 980 981 int (*backlog_rcv) (struct sock *sk, 982 struct sk_buff *skb); 983 984 void (*release_cb)(struct sock *sk); 985 986 /* Keeping track of sk's, looking them up, and port selection methods. */ 987 void (*hash)(struct sock *sk); 988 void (*unhash)(struct sock *sk); 989 void (*rehash)(struct sock *sk); 990 int (*get_port)(struct sock *sk, unsigned short snum); 991 void (*clear_sk)(struct sock *sk, int size); 992 993 /* Keeping track of sockets in use */ 994 #ifdef CONFIG_PROC_FS 995 unsigned int inuse_idx; 996 #endif 997 998 bool (*stream_memory_free)(const struct sock *sk); 999 /* Memory pressure */ 1000 void (*enter_memory_pressure)(struct sock *sk); 1001 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1002 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1003 /* 1004 * Pressure flag: try to collapse. 1005 * Technical note: it is used by multiple contexts non atomically. 1006 * All the __sk_mem_schedule() is of this nature: accounting 1007 * is strict, actions are advisory and have some latency. 1008 */ 1009 int *memory_pressure; 1010 long *sysctl_mem; 1011 int *sysctl_wmem; 1012 int *sysctl_rmem; 1013 int max_header; 1014 bool no_autobind; 1015 1016 struct kmem_cache *slab; 1017 unsigned int obj_size; 1018 int slab_flags; 1019 1020 struct percpu_counter *orphan_count; 1021 1022 struct request_sock_ops *rsk_prot; 1023 struct timewait_sock_ops *twsk_prot; 1024 1025 union { 1026 struct inet_hashinfo *hashinfo; 1027 struct udp_table *udp_table; 1028 struct raw_hashinfo *raw_hash; 1029 } h; 1030 1031 struct module *owner; 1032 1033 char name[32]; 1034 1035 struct list_head node; 1036 #ifdef SOCK_REFCNT_DEBUG 1037 atomic_t socks; 1038 #endif 1039 #ifdef CONFIG_MEMCG_KMEM 1040 /* 1041 * cgroup specific init/deinit functions. Called once for all 1042 * protocols that implement it, from cgroups populate function. 1043 * This function has to setup any files the protocol want to 1044 * appear in the kmem cgroup filesystem. 1045 */ 1046 int (*init_cgroup)(struct mem_cgroup *memcg, 1047 struct cgroup_subsys *ss); 1048 void (*destroy_cgroup)(struct mem_cgroup *memcg); 1049 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg); 1050 #endif 1051 int (*diag_destroy)(struct sock *sk, int err); 1052 }; 1053 1054 int proto_register(struct proto *prot, int alloc_slab); 1055 void proto_unregister(struct proto *prot); 1056 1057 #ifdef SOCK_REFCNT_DEBUG 1058 static inline void sk_refcnt_debug_inc(struct sock *sk) 1059 { 1060 atomic_inc(&sk->sk_prot->socks); 1061 } 1062 1063 static inline void sk_refcnt_debug_dec(struct sock *sk) 1064 { 1065 atomic_dec(&sk->sk_prot->socks); 1066 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1067 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1068 } 1069 1070 static inline void sk_refcnt_debug_release(const struct sock *sk) 1071 { 1072 if (atomic_read(&sk->sk_refcnt) != 1) 1073 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1074 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt)); 1075 } 1076 #else /* SOCK_REFCNT_DEBUG */ 1077 #define sk_refcnt_debug_inc(sk) do { } while (0) 1078 #define sk_refcnt_debug_dec(sk) do { } while (0) 1079 #define sk_refcnt_debug_release(sk) do { } while (0) 1080 #endif /* SOCK_REFCNT_DEBUG */ 1081 1082 static inline bool sk_stream_memory_free(const struct sock *sk) 1083 { 1084 if (sk->sk_wmem_queued >= sk->sk_sndbuf) 1085 return false; 1086 1087 return sk->sk_prot->stream_memory_free ? 1088 sk->sk_prot->stream_memory_free(sk) : true; 1089 } 1090 1091 static inline bool sk_stream_is_writeable(const struct sock *sk) 1092 { 1093 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1094 sk_stream_memory_free(sk); 1095 } 1096 1097 1098 static inline bool sk_has_memory_pressure(const struct sock *sk) 1099 { 1100 return sk->sk_prot->memory_pressure != NULL; 1101 } 1102 1103 static inline bool sk_under_memory_pressure(const struct sock *sk) 1104 { 1105 if (!sk->sk_prot->memory_pressure) 1106 return false; 1107 1108 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 1109 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 1110 return true; 1111 1112 return !!*sk->sk_prot->memory_pressure; 1113 } 1114 1115 static inline void sk_leave_memory_pressure(struct sock *sk) 1116 { 1117 int *memory_pressure = sk->sk_prot->memory_pressure; 1118 1119 if (!memory_pressure) 1120 return; 1121 1122 if (*memory_pressure) 1123 *memory_pressure = 0; 1124 } 1125 1126 static inline void sk_enter_memory_pressure(struct sock *sk) 1127 { 1128 if (!sk->sk_prot->enter_memory_pressure) 1129 return; 1130 1131 sk->sk_prot->enter_memory_pressure(sk); 1132 } 1133 1134 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1135 { 1136 return sk->sk_prot->sysctl_mem[index]; 1137 } 1138 1139 static inline long 1140 sk_memory_allocated(const struct sock *sk) 1141 { 1142 return atomic_long_read(sk->sk_prot->memory_allocated); 1143 } 1144 1145 static inline long 1146 sk_memory_allocated_add(struct sock *sk, int amt) 1147 { 1148 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated); 1149 } 1150 1151 static inline void 1152 sk_memory_allocated_sub(struct sock *sk, int amt) 1153 { 1154 atomic_long_sub(amt, sk->sk_prot->memory_allocated); 1155 } 1156 1157 static inline void sk_sockets_allocated_dec(struct sock *sk) 1158 { 1159 percpu_counter_dec(sk->sk_prot->sockets_allocated); 1160 } 1161 1162 static inline void sk_sockets_allocated_inc(struct sock *sk) 1163 { 1164 percpu_counter_inc(sk->sk_prot->sockets_allocated); 1165 } 1166 1167 static inline int 1168 sk_sockets_allocated_read_positive(struct sock *sk) 1169 { 1170 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated); 1171 } 1172 1173 static inline int 1174 proto_sockets_allocated_sum_positive(struct proto *prot) 1175 { 1176 return percpu_counter_sum_positive(prot->sockets_allocated); 1177 } 1178 1179 static inline long 1180 proto_memory_allocated(struct proto *prot) 1181 { 1182 return atomic_long_read(prot->memory_allocated); 1183 } 1184 1185 static inline bool 1186 proto_memory_pressure(struct proto *prot) 1187 { 1188 if (!prot->memory_pressure) 1189 return false; 1190 return !!*prot->memory_pressure; 1191 } 1192 1193 1194 #ifdef CONFIG_PROC_FS 1195 /* Called with local bh disabled */ 1196 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1197 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1198 #else 1199 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1200 int inc) 1201 { 1202 } 1203 #endif 1204 1205 1206 /* With per-bucket locks this operation is not-atomic, so that 1207 * this version is not worse. 1208 */ 1209 static inline void __sk_prot_rehash(struct sock *sk) 1210 { 1211 sk->sk_prot->unhash(sk); 1212 sk->sk_prot->hash(sk); 1213 } 1214 1215 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 1216 1217 /* About 10 seconds */ 1218 #define SOCK_DESTROY_TIME (10*HZ) 1219 1220 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1221 #define PROT_SOCK 1024 1222 1223 #define SHUTDOWN_MASK 3 1224 #define RCV_SHUTDOWN 1 1225 #define SEND_SHUTDOWN 2 1226 1227 #define SOCK_SNDBUF_LOCK 1 1228 #define SOCK_RCVBUF_LOCK 2 1229 #define SOCK_BINDADDR_LOCK 4 1230 #define SOCK_BINDPORT_LOCK 8 1231 1232 struct socket_alloc { 1233 struct socket socket; 1234 struct inode vfs_inode; 1235 }; 1236 1237 static inline struct socket *SOCKET_I(struct inode *inode) 1238 { 1239 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1240 } 1241 1242 static inline struct inode *SOCK_INODE(struct socket *socket) 1243 { 1244 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1245 } 1246 1247 /* 1248 * Functions for memory accounting 1249 */ 1250 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1251 void __sk_mem_reclaim(struct sock *sk, int amount); 1252 1253 #define SK_MEM_QUANTUM ((int)PAGE_SIZE) 1254 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1255 #define SK_MEM_SEND 0 1256 #define SK_MEM_RECV 1 1257 1258 static inline int sk_mem_pages(int amt) 1259 { 1260 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1261 } 1262 1263 static inline bool sk_has_account(struct sock *sk) 1264 { 1265 /* return true if protocol supports memory accounting */ 1266 return !!sk->sk_prot->memory_allocated; 1267 } 1268 1269 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1270 { 1271 if (!sk_has_account(sk)) 1272 return true; 1273 return size <= sk->sk_forward_alloc || 1274 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1275 } 1276 1277 static inline bool 1278 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1279 { 1280 if (!sk_has_account(sk)) 1281 return true; 1282 return size<= sk->sk_forward_alloc || 1283 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1284 skb_pfmemalloc(skb); 1285 } 1286 1287 static inline void sk_mem_reclaim(struct sock *sk) 1288 { 1289 if (!sk_has_account(sk)) 1290 return; 1291 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1292 __sk_mem_reclaim(sk, sk->sk_forward_alloc); 1293 } 1294 1295 static inline void sk_mem_reclaim_partial(struct sock *sk) 1296 { 1297 if (!sk_has_account(sk)) 1298 return; 1299 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1300 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); 1301 } 1302 1303 static inline void sk_mem_charge(struct sock *sk, int size) 1304 { 1305 if (!sk_has_account(sk)) 1306 return; 1307 sk->sk_forward_alloc -= size; 1308 } 1309 1310 static inline void sk_mem_uncharge(struct sock *sk, int size) 1311 { 1312 if (!sk_has_account(sk)) 1313 return; 1314 sk->sk_forward_alloc += size; 1315 } 1316 1317 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1318 { 1319 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1320 sk->sk_wmem_queued -= skb->truesize; 1321 sk_mem_uncharge(sk, skb->truesize); 1322 __kfree_skb(skb); 1323 } 1324 1325 /* Used by processes to "lock" a socket state, so that 1326 * interrupts and bottom half handlers won't change it 1327 * from under us. It essentially blocks any incoming 1328 * packets, so that we won't get any new data or any 1329 * packets that change the state of the socket. 1330 * 1331 * While locked, BH processing will add new packets to 1332 * the backlog queue. This queue is processed by the 1333 * owner of the socket lock right before it is released. 1334 * 1335 * Since ~2.3.5 it is also exclusive sleep lock serializing 1336 * accesses from user process context. 1337 */ 1338 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned) 1339 1340 static inline void sock_release_ownership(struct sock *sk) 1341 { 1342 sk->sk_lock.owned = 0; 1343 } 1344 1345 /* 1346 * Macro so as to not evaluate some arguments when 1347 * lockdep is not enabled. 1348 * 1349 * Mark both the sk_lock and the sk_lock.slock as a 1350 * per-address-family lock class. 1351 */ 1352 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1353 do { \ 1354 sk->sk_lock.owned = 0; \ 1355 init_waitqueue_head(&sk->sk_lock.wq); \ 1356 spin_lock_init(&(sk)->sk_lock.slock); \ 1357 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1358 sizeof((sk)->sk_lock)); \ 1359 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1360 (skey), (sname)); \ 1361 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1362 } while (0) 1363 1364 void lock_sock_nested(struct sock *sk, int subclass); 1365 1366 static inline void lock_sock(struct sock *sk) 1367 { 1368 lock_sock_nested(sk, 0); 1369 } 1370 1371 void release_sock(struct sock *sk); 1372 1373 /* BH context may only use the following locking interface. */ 1374 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1375 #define bh_lock_sock_nested(__sk) \ 1376 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1377 SINGLE_DEPTH_NESTING) 1378 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1379 1380 bool lock_sock_fast(struct sock *sk); 1381 /** 1382 * unlock_sock_fast - complement of lock_sock_fast 1383 * @sk: socket 1384 * @slow: slow mode 1385 * 1386 * fast unlock socket for user context. 1387 * If slow mode is on, we call regular release_sock() 1388 */ 1389 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1390 { 1391 if (slow) 1392 release_sock(sk); 1393 else 1394 spin_unlock_bh(&sk->sk_lock.slock); 1395 } 1396 1397 1398 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1399 struct proto *prot, int kern); 1400 void sk_free(struct sock *sk); 1401 void sk_destruct(struct sock *sk); 1402 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1403 1404 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1405 gfp_t priority); 1406 void sock_wfree(struct sk_buff *skb); 1407 void skb_orphan_partial(struct sk_buff *skb); 1408 void sock_rfree(struct sk_buff *skb); 1409 void sock_efree(struct sk_buff *skb); 1410 #ifdef CONFIG_INET 1411 void sock_edemux(struct sk_buff *skb); 1412 #else 1413 #define sock_edemux(skb) sock_efree(skb) 1414 #endif 1415 1416 int sock_setsockopt(struct socket *sock, int level, int op, 1417 char __user *optval, unsigned int optlen); 1418 1419 int sock_getsockopt(struct socket *sock, int level, int op, 1420 char __user *optval, int __user *optlen); 1421 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1422 int noblock, int *errcode); 1423 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1424 unsigned long data_len, int noblock, 1425 int *errcode, int max_page_order); 1426 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1427 void sock_kfree_s(struct sock *sk, void *mem, int size); 1428 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1429 void sk_send_sigurg(struct sock *sk); 1430 1431 struct sockcm_cookie { 1432 u32 mark; 1433 }; 1434 1435 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1436 struct sockcm_cookie *sockc); 1437 1438 /* 1439 * Functions to fill in entries in struct proto_ops when a protocol 1440 * does not implement a particular function. 1441 */ 1442 int sock_no_bind(struct socket *, struct sockaddr *, int); 1443 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1444 int sock_no_socketpair(struct socket *, struct socket *); 1445 int sock_no_accept(struct socket *, struct socket *, int); 1446 int sock_no_getname(struct socket *, struct sockaddr *, int *, int); 1447 unsigned int sock_no_poll(struct file *, struct socket *, 1448 struct poll_table_struct *); 1449 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1450 int sock_no_listen(struct socket *, int); 1451 int sock_no_shutdown(struct socket *, int); 1452 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *); 1453 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int); 1454 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1455 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1456 int sock_no_mmap(struct file *file, struct socket *sock, 1457 struct vm_area_struct *vma); 1458 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1459 size_t size, int flags); 1460 1461 /* 1462 * Functions to fill in entries in struct proto_ops when a protocol 1463 * uses the inet style. 1464 */ 1465 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1466 char __user *optval, int __user *optlen); 1467 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1468 int flags); 1469 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1470 char __user *optval, unsigned int optlen); 1471 int compat_sock_common_getsockopt(struct socket *sock, int level, 1472 int optname, char __user *optval, int __user *optlen); 1473 int compat_sock_common_setsockopt(struct socket *sock, int level, 1474 int optname, char __user *optval, unsigned int optlen); 1475 1476 void sk_common_release(struct sock *sk); 1477 1478 /* 1479 * Default socket callbacks and setup code 1480 */ 1481 1482 /* Initialise core socket variables */ 1483 void sock_init_data(struct socket *sock, struct sock *sk); 1484 1485 /* 1486 * Socket reference counting postulates. 1487 * 1488 * * Each user of socket SHOULD hold a reference count. 1489 * * Each access point to socket (an hash table bucket, reference from a list, 1490 * running timer, skb in flight MUST hold a reference count. 1491 * * When reference count hits 0, it means it will never increase back. 1492 * * When reference count hits 0, it means that no references from 1493 * outside exist to this socket and current process on current CPU 1494 * is last user and may/should destroy this socket. 1495 * * sk_free is called from any context: process, BH, IRQ. When 1496 * it is called, socket has no references from outside -> sk_free 1497 * may release descendant resources allocated by the socket, but 1498 * to the time when it is called, socket is NOT referenced by any 1499 * hash tables, lists etc. 1500 * * Packets, delivered from outside (from network or from another process) 1501 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1502 * when they sit in queue. Otherwise, packets will leak to hole, when 1503 * socket is looked up by one cpu and unhasing is made by another CPU. 1504 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1505 * (leak to backlog). Packet socket does all the processing inside 1506 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1507 * use separate SMP lock, so that they are prone too. 1508 */ 1509 1510 /* Ungrab socket and destroy it, if it was the last reference. */ 1511 static inline void sock_put(struct sock *sk) 1512 { 1513 if (atomic_dec_and_test(&sk->sk_refcnt)) 1514 sk_free(sk); 1515 } 1516 /* Generic version of sock_put(), dealing with all sockets 1517 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1518 */ 1519 void sock_gen_put(struct sock *sk); 1520 1521 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested); 1522 1523 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1524 { 1525 sk->sk_tx_queue_mapping = tx_queue; 1526 } 1527 1528 static inline void sk_tx_queue_clear(struct sock *sk) 1529 { 1530 sk->sk_tx_queue_mapping = -1; 1531 } 1532 1533 static inline int sk_tx_queue_get(const struct sock *sk) 1534 { 1535 return sk ? sk->sk_tx_queue_mapping : -1; 1536 } 1537 1538 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1539 { 1540 sk_tx_queue_clear(sk); 1541 sk->sk_socket = sock; 1542 } 1543 1544 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1545 { 1546 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1547 return &rcu_dereference_raw(sk->sk_wq)->wait; 1548 } 1549 /* Detach socket from process context. 1550 * Announce socket dead, detach it from wait queue and inode. 1551 * Note that parent inode held reference count on this struct sock, 1552 * we do not release it in this function, because protocol 1553 * probably wants some additional cleanups or even continuing 1554 * to work with this socket (TCP). 1555 */ 1556 static inline void sock_orphan(struct sock *sk) 1557 { 1558 write_lock_bh(&sk->sk_callback_lock); 1559 sock_set_flag(sk, SOCK_DEAD); 1560 sk_set_socket(sk, NULL); 1561 sk->sk_wq = NULL; 1562 write_unlock_bh(&sk->sk_callback_lock); 1563 } 1564 1565 static inline void sock_graft(struct sock *sk, struct socket *parent) 1566 { 1567 write_lock_bh(&sk->sk_callback_lock); 1568 sk->sk_wq = parent->wq; 1569 parent->sk = sk; 1570 sk_set_socket(sk, parent); 1571 security_sock_graft(sk, parent); 1572 write_unlock_bh(&sk->sk_callback_lock); 1573 } 1574 1575 kuid_t sock_i_uid(struct sock *sk); 1576 unsigned long sock_i_ino(struct sock *sk); 1577 1578 static inline u32 net_tx_rndhash(void) 1579 { 1580 u32 v = prandom_u32(); 1581 1582 return v ?: 1; 1583 } 1584 1585 static inline void sk_set_txhash(struct sock *sk) 1586 { 1587 sk->sk_txhash = net_tx_rndhash(); 1588 } 1589 1590 static inline void sk_rethink_txhash(struct sock *sk) 1591 { 1592 if (sk->sk_txhash) 1593 sk_set_txhash(sk); 1594 } 1595 1596 static inline struct dst_entry * 1597 __sk_dst_get(struct sock *sk) 1598 { 1599 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) || 1600 lockdep_is_held(&sk->sk_lock.slock)); 1601 } 1602 1603 static inline struct dst_entry * 1604 sk_dst_get(struct sock *sk) 1605 { 1606 struct dst_entry *dst; 1607 1608 rcu_read_lock(); 1609 dst = rcu_dereference(sk->sk_dst_cache); 1610 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 1611 dst = NULL; 1612 rcu_read_unlock(); 1613 return dst; 1614 } 1615 1616 static inline void dst_negative_advice(struct sock *sk) 1617 { 1618 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1619 1620 sk_rethink_txhash(sk); 1621 1622 if (dst && dst->ops->negative_advice) { 1623 ndst = dst->ops->negative_advice(dst); 1624 1625 if (ndst != dst) { 1626 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1627 sk_tx_queue_clear(sk); 1628 } 1629 } 1630 } 1631 1632 static inline void 1633 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1634 { 1635 struct dst_entry *old_dst; 1636 1637 sk_tx_queue_clear(sk); 1638 /* 1639 * This can be called while sk is owned by the caller only, 1640 * with no state that can be checked in a rcu_dereference_check() cond 1641 */ 1642 old_dst = rcu_dereference_raw(sk->sk_dst_cache); 1643 rcu_assign_pointer(sk->sk_dst_cache, dst); 1644 dst_release(old_dst); 1645 } 1646 1647 static inline void 1648 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1649 { 1650 struct dst_entry *old_dst; 1651 1652 sk_tx_queue_clear(sk); 1653 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 1654 dst_release(old_dst); 1655 } 1656 1657 static inline void 1658 __sk_dst_reset(struct sock *sk) 1659 { 1660 __sk_dst_set(sk, NULL); 1661 } 1662 1663 static inline void 1664 sk_dst_reset(struct sock *sk) 1665 { 1666 sk_dst_set(sk, NULL); 1667 } 1668 1669 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1670 1671 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1672 1673 bool sk_mc_loop(struct sock *sk); 1674 1675 static inline bool sk_can_gso(const struct sock *sk) 1676 { 1677 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1678 } 1679 1680 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1681 1682 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1683 { 1684 sk->sk_route_nocaps |= flags; 1685 sk->sk_route_caps &= ~flags; 1686 } 1687 1688 static inline bool sk_check_csum_caps(struct sock *sk) 1689 { 1690 return (sk->sk_route_caps & NETIF_F_HW_CSUM) || 1691 (sk->sk_family == PF_INET && 1692 (sk->sk_route_caps & NETIF_F_IP_CSUM)) || 1693 (sk->sk_family == PF_INET6 && 1694 (sk->sk_route_caps & NETIF_F_IPV6_CSUM)); 1695 } 1696 1697 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1698 struct iov_iter *from, char *to, 1699 int copy, int offset) 1700 { 1701 if (skb->ip_summed == CHECKSUM_NONE) { 1702 __wsum csum = 0; 1703 if (csum_and_copy_from_iter(to, copy, &csum, from) != copy) 1704 return -EFAULT; 1705 skb->csum = csum_block_add(skb->csum, csum, offset); 1706 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1707 if (copy_from_iter_nocache(to, copy, from) != copy) 1708 return -EFAULT; 1709 } else if (copy_from_iter(to, copy, from) != copy) 1710 return -EFAULT; 1711 1712 return 0; 1713 } 1714 1715 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1716 struct iov_iter *from, int copy) 1717 { 1718 int err, offset = skb->len; 1719 1720 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1721 copy, offset); 1722 if (err) 1723 __skb_trim(skb, offset); 1724 1725 return err; 1726 } 1727 1728 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 1729 struct sk_buff *skb, 1730 struct page *page, 1731 int off, int copy) 1732 { 1733 int err; 1734 1735 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1736 copy, skb->len); 1737 if (err) 1738 return err; 1739 1740 skb->len += copy; 1741 skb->data_len += copy; 1742 skb->truesize += copy; 1743 sk->sk_wmem_queued += copy; 1744 sk_mem_charge(sk, copy); 1745 return 0; 1746 } 1747 1748 /** 1749 * sk_wmem_alloc_get - returns write allocations 1750 * @sk: socket 1751 * 1752 * Returns sk_wmem_alloc minus initial offset of one 1753 */ 1754 static inline int sk_wmem_alloc_get(const struct sock *sk) 1755 { 1756 return atomic_read(&sk->sk_wmem_alloc) - 1; 1757 } 1758 1759 /** 1760 * sk_rmem_alloc_get - returns read allocations 1761 * @sk: socket 1762 * 1763 * Returns sk_rmem_alloc 1764 */ 1765 static inline int sk_rmem_alloc_get(const struct sock *sk) 1766 { 1767 return atomic_read(&sk->sk_rmem_alloc); 1768 } 1769 1770 /** 1771 * sk_has_allocations - check if allocations are outstanding 1772 * @sk: socket 1773 * 1774 * Returns true if socket has write or read allocations 1775 */ 1776 static inline bool sk_has_allocations(const struct sock *sk) 1777 { 1778 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1779 } 1780 1781 /** 1782 * skwq_has_sleeper - check if there are any waiting processes 1783 * @wq: struct socket_wq 1784 * 1785 * Returns true if socket_wq has waiting processes 1786 * 1787 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory 1788 * barrier call. They were added due to the race found within the tcp code. 1789 * 1790 * Consider following tcp code paths: 1791 * 1792 * CPU1 CPU2 1793 * 1794 * sys_select receive packet 1795 * ... ... 1796 * __add_wait_queue update tp->rcv_nxt 1797 * ... ... 1798 * tp->rcv_nxt check sock_def_readable 1799 * ... { 1800 * schedule rcu_read_lock(); 1801 * wq = rcu_dereference(sk->sk_wq); 1802 * if (wq && waitqueue_active(&wq->wait)) 1803 * wake_up_interruptible(&wq->wait) 1804 * ... 1805 * } 1806 * 1807 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1808 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1809 * could then endup calling schedule and sleep forever if there are no more 1810 * data on the socket. 1811 * 1812 */ 1813 static inline bool skwq_has_sleeper(struct socket_wq *wq) 1814 { 1815 return wq && wq_has_sleeper(&wq->wait); 1816 } 1817 1818 /** 1819 * sock_poll_wait - place memory barrier behind the poll_wait call. 1820 * @filp: file 1821 * @wait_address: socket wait queue 1822 * @p: poll_table 1823 * 1824 * See the comments in the wq_has_sleeper function. 1825 */ 1826 static inline void sock_poll_wait(struct file *filp, 1827 wait_queue_head_t *wait_address, poll_table *p) 1828 { 1829 if (!poll_does_not_wait(p) && wait_address) { 1830 poll_wait(filp, wait_address, p); 1831 /* We need to be sure we are in sync with the 1832 * socket flags modification. 1833 * 1834 * This memory barrier is paired in the wq_has_sleeper. 1835 */ 1836 smp_mb(); 1837 } 1838 } 1839 1840 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 1841 { 1842 if (sk->sk_txhash) { 1843 skb->l4_hash = 1; 1844 skb->hash = sk->sk_txhash; 1845 } 1846 } 1847 1848 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 1849 1850 /* 1851 * Queue a received datagram if it will fit. Stream and sequenced 1852 * protocols can't normally use this as they need to fit buffers in 1853 * and play with them. 1854 * 1855 * Inlined as it's very short and called for pretty much every 1856 * packet ever received. 1857 */ 1858 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 1859 { 1860 skb_orphan(skb); 1861 skb->sk = sk; 1862 skb->destructor = sock_rfree; 1863 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 1864 sk_mem_charge(sk, skb->truesize); 1865 } 1866 1867 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 1868 unsigned long expires); 1869 1870 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 1871 1872 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 1873 1874 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 1875 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 1876 1877 /* 1878 * Recover an error report and clear atomically 1879 */ 1880 1881 static inline int sock_error(struct sock *sk) 1882 { 1883 int err; 1884 if (likely(!sk->sk_err)) 1885 return 0; 1886 err = xchg(&sk->sk_err, 0); 1887 return -err; 1888 } 1889 1890 static inline unsigned long sock_wspace(struct sock *sk) 1891 { 1892 int amt = 0; 1893 1894 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 1895 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc); 1896 if (amt < 0) 1897 amt = 0; 1898 } 1899 return amt; 1900 } 1901 1902 /* Note: 1903 * We use sk->sk_wq_raw, from contexts knowing this 1904 * pointer is not NULL and cannot disappear/change. 1905 */ 1906 static inline void sk_set_bit(int nr, struct sock *sk) 1907 { 1908 set_bit(nr, &sk->sk_wq_raw->flags); 1909 } 1910 1911 static inline void sk_clear_bit(int nr, struct sock *sk) 1912 { 1913 clear_bit(nr, &sk->sk_wq_raw->flags); 1914 } 1915 1916 static inline void sk_wake_async(const struct sock *sk, int how, int band) 1917 { 1918 if (sock_flag(sk, SOCK_FASYNC)) { 1919 rcu_read_lock(); 1920 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 1921 rcu_read_unlock(); 1922 } 1923 } 1924 1925 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 1926 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 1927 * Note: for send buffers, TCP works better if we can build two skbs at 1928 * minimum. 1929 */ 1930 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 1931 1932 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 1933 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 1934 1935 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 1936 { 1937 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 1938 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 1939 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); 1940 } 1941 } 1942 1943 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 1944 bool force_schedule); 1945 1946 /** 1947 * sk_page_frag - return an appropriate page_frag 1948 * @sk: socket 1949 * 1950 * If socket allocation mode allows current thread to sleep, it means its 1951 * safe to use the per task page_frag instead of the per socket one. 1952 */ 1953 static inline struct page_frag *sk_page_frag(struct sock *sk) 1954 { 1955 if (gfpflags_allow_blocking(sk->sk_allocation)) 1956 return ¤t->task_frag; 1957 1958 return &sk->sk_frag; 1959 } 1960 1961 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 1962 1963 /* 1964 * Default write policy as shown to user space via poll/select/SIGIO 1965 */ 1966 static inline bool sock_writeable(const struct sock *sk) 1967 { 1968 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 1969 } 1970 1971 static inline gfp_t gfp_any(void) 1972 { 1973 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 1974 } 1975 1976 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 1977 { 1978 return noblock ? 0 : sk->sk_rcvtimeo; 1979 } 1980 1981 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 1982 { 1983 return noblock ? 0 : sk->sk_sndtimeo; 1984 } 1985 1986 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 1987 { 1988 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 1989 } 1990 1991 /* Alas, with timeout socket operations are not restartable. 1992 * Compare this to poll(). 1993 */ 1994 static inline int sock_intr_errno(long timeo) 1995 { 1996 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 1997 } 1998 1999 struct sock_skb_cb { 2000 u32 dropcount; 2001 }; 2002 2003 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2004 * using skb->cb[] would keep using it directly and utilize its 2005 * alignement guarantee. 2006 */ 2007 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \ 2008 sizeof(struct sock_skb_cb))) 2009 2010 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2011 SOCK_SKB_CB_OFFSET)) 2012 2013 #define sock_skb_cb_check_size(size) \ 2014 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2015 2016 static inline void 2017 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2018 { 2019 SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops); 2020 } 2021 2022 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2023 struct sk_buff *skb); 2024 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2025 struct sk_buff *skb); 2026 2027 static inline void 2028 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2029 { 2030 ktime_t kt = skb->tstamp; 2031 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2032 2033 /* 2034 * generate control messages if 2035 * - receive time stamping in software requested 2036 * - software time stamp available and wanted 2037 * - hardware time stamps available and wanted 2038 */ 2039 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2040 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2041 (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2042 (hwtstamps->hwtstamp.tv64 && 2043 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2044 __sock_recv_timestamp(msg, sk, skb); 2045 else 2046 sk->sk_stamp = kt; 2047 2048 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2049 __sock_recv_wifi_status(msg, sk, skb); 2050 } 2051 2052 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2053 struct sk_buff *skb); 2054 2055 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2056 struct sk_buff *skb) 2057 { 2058 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2059 (1UL << SOCK_RCVTSTAMP)) 2060 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2061 SOF_TIMESTAMPING_RAW_HARDWARE) 2062 2063 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2064 __sock_recv_ts_and_drops(msg, sk, skb); 2065 else 2066 sk->sk_stamp = skb->tstamp; 2067 } 2068 2069 void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags); 2070 2071 /** 2072 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2073 * @sk: socket sending this packet 2074 * @tx_flags: completed with instructions for time stamping 2075 * 2076 * Note : callers should take care of initial *tx_flags value (usually 0) 2077 */ 2078 static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags) 2079 { 2080 if (unlikely(sk->sk_tsflags)) 2081 __sock_tx_timestamp(sk, tx_flags); 2082 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2083 *tx_flags |= SKBTX_WIFI_STATUS; 2084 } 2085 2086 /** 2087 * sk_eat_skb - Release a skb if it is no longer needed 2088 * @sk: socket to eat this skb from 2089 * @skb: socket buffer to eat 2090 * 2091 * This routine must be called with interrupts disabled or with the socket 2092 * locked so that the sk_buff queue operation is ok. 2093 */ 2094 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2095 { 2096 __skb_unlink(skb, &sk->sk_receive_queue); 2097 __kfree_skb(skb); 2098 } 2099 2100 static inline 2101 struct net *sock_net(const struct sock *sk) 2102 { 2103 return read_pnet(&sk->sk_net); 2104 } 2105 2106 static inline 2107 void sock_net_set(struct sock *sk, struct net *net) 2108 { 2109 write_pnet(&sk->sk_net, net); 2110 } 2111 2112 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2113 { 2114 if (skb->sk) { 2115 struct sock *sk = skb->sk; 2116 2117 skb->destructor = NULL; 2118 skb->sk = NULL; 2119 return sk; 2120 } 2121 return NULL; 2122 } 2123 2124 /* This helper checks if a socket is a full socket, 2125 * ie _not_ a timewait or request socket. 2126 */ 2127 static inline bool sk_fullsock(const struct sock *sk) 2128 { 2129 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2130 } 2131 2132 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2133 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2134 */ 2135 static inline bool sk_listener(const struct sock *sk) 2136 { 2137 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2138 } 2139 2140 /** 2141 * sk_state_load - read sk->sk_state for lockless contexts 2142 * @sk: socket pointer 2143 * 2144 * Paired with sk_state_store(). Used in places we do not hold socket lock : 2145 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... 2146 */ 2147 static inline int sk_state_load(const struct sock *sk) 2148 { 2149 return smp_load_acquire(&sk->sk_state); 2150 } 2151 2152 /** 2153 * sk_state_store - update sk->sk_state 2154 * @sk: socket pointer 2155 * @newstate: new state 2156 * 2157 * Paired with sk_state_load(). Should be used in contexts where 2158 * state change might impact lockless readers. 2159 */ 2160 static inline void sk_state_store(struct sock *sk, int newstate) 2161 { 2162 smp_store_release(&sk->sk_state, newstate); 2163 } 2164 2165 void sock_enable_timestamp(struct sock *sk, int flag); 2166 int sock_get_timestamp(struct sock *, struct timeval __user *); 2167 int sock_get_timestampns(struct sock *, struct timespec __user *); 2168 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2169 int type); 2170 2171 bool sk_ns_capable(const struct sock *sk, 2172 struct user_namespace *user_ns, int cap); 2173 bool sk_capable(const struct sock *sk, int cap); 2174 bool sk_net_capable(const struct sock *sk, int cap); 2175 2176 extern __u32 sysctl_wmem_max; 2177 extern __u32 sysctl_rmem_max; 2178 2179 extern int sysctl_tstamp_allow_data; 2180 extern int sysctl_optmem_max; 2181 2182 extern __u32 sysctl_wmem_default; 2183 extern __u32 sysctl_rmem_default; 2184 2185 #endif /* _SOCK_H */ 2186