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 #include <linux/rbtree.h> 64 #include <linux/filter.h> 65 #include <linux/rculist_nulls.h> 66 #include <linux/poll.h> 67 68 #include <linux/atomic.h> 69 #include <linux/refcount.h> 70 #include <net/dst.h> 71 #include <net/checksum.h> 72 #include <net/tcp_states.h> 73 #include <linux/net_tstamp.h> 74 #include <net/smc.h> 75 76 /* 77 * This structure really needs to be cleaned up. 78 * Most of it is for TCP, and not used by any of 79 * the other protocols. 80 */ 81 82 /* Define this to get the SOCK_DBG debugging facility. */ 83 #define SOCK_DEBUGGING 84 #ifdef SOCK_DEBUGGING 85 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 86 printk(KERN_DEBUG msg); } while (0) 87 #else 88 /* Validate arguments and do nothing */ 89 static inline __printf(2, 3) 90 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 91 { 92 } 93 #endif 94 95 /* This is the per-socket lock. The spinlock provides a synchronization 96 * between user contexts and software interrupt processing, whereas the 97 * mini-semaphore synchronizes multiple users amongst themselves. 98 */ 99 typedef struct { 100 spinlock_t slock; 101 int owned; 102 wait_queue_head_t wq; 103 /* 104 * We express the mutex-alike socket_lock semantics 105 * to the lock validator by explicitly managing 106 * the slock as a lock variant (in addition to 107 * the slock itself): 108 */ 109 #ifdef CONFIG_DEBUG_LOCK_ALLOC 110 struct lockdep_map dep_map; 111 #endif 112 } socket_lock_t; 113 114 struct sock; 115 struct proto; 116 struct net; 117 118 typedef __u32 __bitwise __portpair; 119 typedef __u64 __bitwise __addrpair; 120 121 /** 122 * struct sock_common - minimal network layer representation of sockets 123 * @skc_daddr: Foreign IPv4 addr 124 * @skc_rcv_saddr: Bound local IPv4 addr 125 * @skc_hash: hash value used with various protocol lookup tables 126 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 127 * @skc_dport: placeholder for inet_dport/tw_dport 128 * @skc_num: placeholder for inet_num/tw_num 129 * @skc_family: network address family 130 * @skc_state: Connection state 131 * @skc_reuse: %SO_REUSEADDR setting 132 * @skc_reuseport: %SO_REUSEPORT setting 133 * @skc_bound_dev_if: bound device index if != 0 134 * @skc_bind_node: bind hash linkage for various protocol lookup tables 135 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 136 * @skc_prot: protocol handlers inside a network family 137 * @skc_net: reference to the network namespace of this socket 138 * @skc_node: main hash linkage for various protocol lookup tables 139 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 140 * @skc_tx_queue_mapping: tx queue number for this connection 141 * @skc_flags: place holder for sk_flags 142 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 143 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 144 * @skc_incoming_cpu: record/match cpu processing incoming packets 145 * @skc_refcnt: reference count 146 * 147 * This is the minimal network layer representation of sockets, the header 148 * for struct sock and struct inet_timewait_sock. 149 */ 150 struct sock_common { 151 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 152 * address on 64bit arches : cf INET_MATCH() 153 */ 154 union { 155 __addrpair skc_addrpair; 156 struct { 157 __be32 skc_daddr; 158 __be32 skc_rcv_saddr; 159 }; 160 }; 161 union { 162 unsigned int skc_hash; 163 __u16 skc_u16hashes[2]; 164 }; 165 /* skc_dport && skc_num must be grouped as well */ 166 union { 167 __portpair skc_portpair; 168 struct { 169 __be16 skc_dport; 170 __u16 skc_num; 171 }; 172 }; 173 174 unsigned short skc_family; 175 volatile unsigned char skc_state; 176 unsigned char skc_reuse:4; 177 unsigned char skc_reuseport:1; 178 unsigned char skc_ipv6only:1; 179 unsigned char skc_net_refcnt:1; 180 int skc_bound_dev_if; 181 union { 182 struct hlist_node skc_bind_node; 183 struct hlist_node skc_portaddr_node; 184 }; 185 struct proto *skc_prot; 186 possible_net_t skc_net; 187 188 #if IS_ENABLED(CONFIG_IPV6) 189 struct in6_addr skc_v6_daddr; 190 struct in6_addr skc_v6_rcv_saddr; 191 #endif 192 193 atomic64_t skc_cookie; 194 195 /* following fields are padding to force 196 * offset(struct sock, sk_refcnt) == 128 on 64bit arches 197 * assuming IPV6 is enabled. We use this padding differently 198 * for different kind of 'sockets' 199 */ 200 union { 201 unsigned long skc_flags; 202 struct sock *skc_listener; /* request_sock */ 203 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */ 204 }; 205 /* 206 * fields between dontcopy_begin/dontcopy_end 207 * are not copied in sock_copy() 208 */ 209 /* private: */ 210 int skc_dontcopy_begin[0]; 211 /* public: */ 212 union { 213 struct hlist_node skc_node; 214 struct hlist_nulls_node skc_nulls_node; 215 }; 216 int skc_tx_queue_mapping; 217 union { 218 int skc_incoming_cpu; 219 u32 skc_rcv_wnd; 220 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */ 221 }; 222 223 refcount_t skc_refcnt; 224 /* private: */ 225 int skc_dontcopy_end[0]; 226 union { 227 u32 skc_rxhash; 228 u32 skc_window_clamp; 229 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ 230 }; 231 /* public: */ 232 }; 233 234 /** 235 * struct sock - network layer representation of sockets 236 * @__sk_common: shared layout with inet_timewait_sock 237 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 238 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 239 * @sk_lock: synchronizer 240 * @sk_kern_sock: True if sock is using kernel lock classes 241 * @sk_rcvbuf: size of receive buffer in bytes 242 * @sk_wq: sock wait queue and async head 243 * @sk_rx_dst: receive input route used by early demux 244 * @sk_dst_cache: destination cache 245 * @sk_dst_pending_confirm: need to confirm neighbour 246 * @sk_policy: flow policy 247 * @sk_receive_queue: incoming packets 248 * @sk_wmem_alloc: transmit queue bytes committed 249 * @sk_tsq_flags: TCP Small Queues flags 250 * @sk_write_queue: Packet sending queue 251 * @sk_omem_alloc: "o" is "option" or "other" 252 * @sk_wmem_queued: persistent queue size 253 * @sk_forward_alloc: space allocated forward 254 * @sk_napi_id: id of the last napi context to receive data for sk 255 * @sk_ll_usec: usecs to busypoll when there is no data 256 * @sk_allocation: allocation mode 257 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler) 258 * @sk_pacing_status: Pacing status (requested, handled by sch_fq) 259 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE) 260 * @sk_sndbuf: size of send buffer in bytes 261 * @__sk_flags_offset: empty field used to determine location of bitfield 262 * @sk_padding: unused element for alignment 263 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets 264 * @sk_no_check_rx: allow zero checksum in RX packets 265 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 266 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 267 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 268 * @sk_gso_max_size: Maximum GSO segment size to build 269 * @sk_gso_max_segs: Maximum number of GSO segments 270 * @sk_lingertime: %SO_LINGER l_linger setting 271 * @sk_backlog: always used with the per-socket spinlock held 272 * @sk_callback_lock: used with the callbacks in the end of this struct 273 * @sk_error_queue: rarely used 274 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 275 * IPV6_ADDRFORM for instance) 276 * @sk_err: last error 277 * @sk_err_soft: errors that don't cause failure but are the cause of a 278 * persistent failure not just 'timed out' 279 * @sk_drops: raw/udp drops counter 280 * @sk_ack_backlog: current listen backlog 281 * @sk_max_ack_backlog: listen backlog set in listen() 282 * @sk_uid: user id of owner 283 * @sk_priority: %SO_PRIORITY setting 284 * @sk_type: socket type (%SOCK_STREAM, etc) 285 * @sk_protocol: which protocol this socket belongs in this network family 286 * @sk_peer_pid: &struct pid for this socket's peer 287 * @sk_peer_cred: %SO_PEERCRED setting 288 * @sk_rcvlowat: %SO_RCVLOWAT setting 289 * @sk_rcvtimeo: %SO_RCVTIMEO setting 290 * @sk_sndtimeo: %SO_SNDTIMEO setting 291 * @sk_txhash: computed flow hash for use on transmit 292 * @sk_filter: socket filtering instructions 293 * @sk_timer: sock cleanup timer 294 * @sk_stamp: time stamp of last packet received 295 * @sk_tsflags: SO_TIMESTAMPING socket options 296 * @sk_tskey: counter to disambiguate concurrent tstamp requests 297 * @sk_zckey: counter to order MSG_ZEROCOPY notifications 298 * @sk_socket: Identd and reporting IO signals 299 * @sk_user_data: RPC layer private data 300 * @sk_frag: cached page frag 301 * @sk_peek_off: current peek_offset value 302 * @sk_send_head: front of stuff to transmit 303 * @sk_security: used by security modules 304 * @sk_mark: generic packet mark 305 * @sk_cgrp_data: cgroup data for this cgroup 306 * @sk_memcg: this socket's memory cgroup association 307 * @sk_write_pending: a write to stream socket waits to start 308 * @sk_state_change: callback to indicate change in the state of the sock 309 * @sk_data_ready: callback to indicate there is data to be processed 310 * @sk_write_space: callback to indicate there is bf sending space available 311 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 312 * @sk_backlog_rcv: callback to process the backlog 313 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 314 * @sk_reuseport_cb: reuseport group container 315 * @sk_rcu: used during RCU grace period 316 */ 317 struct sock { 318 /* 319 * Now struct inet_timewait_sock also uses sock_common, so please just 320 * don't add nothing before this first member (__sk_common) --acme 321 */ 322 struct sock_common __sk_common; 323 #define sk_node __sk_common.skc_node 324 #define sk_nulls_node __sk_common.skc_nulls_node 325 #define sk_refcnt __sk_common.skc_refcnt 326 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 327 328 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 329 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 330 #define sk_hash __sk_common.skc_hash 331 #define sk_portpair __sk_common.skc_portpair 332 #define sk_num __sk_common.skc_num 333 #define sk_dport __sk_common.skc_dport 334 #define sk_addrpair __sk_common.skc_addrpair 335 #define sk_daddr __sk_common.skc_daddr 336 #define sk_rcv_saddr __sk_common.skc_rcv_saddr 337 #define sk_family __sk_common.skc_family 338 #define sk_state __sk_common.skc_state 339 #define sk_reuse __sk_common.skc_reuse 340 #define sk_reuseport __sk_common.skc_reuseport 341 #define sk_ipv6only __sk_common.skc_ipv6only 342 #define sk_net_refcnt __sk_common.skc_net_refcnt 343 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 344 #define sk_bind_node __sk_common.skc_bind_node 345 #define sk_prot __sk_common.skc_prot 346 #define sk_net __sk_common.skc_net 347 #define sk_v6_daddr __sk_common.skc_v6_daddr 348 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr 349 #define sk_cookie __sk_common.skc_cookie 350 #define sk_incoming_cpu __sk_common.skc_incoming_cpu 351 #define sk_flags __sk_common.skc_flags 352 #define sk_rxhash __sk_common.skc_rxhash 353 354 socket_lock_t sk_lock; 355 atomic_t sk_drops; 356 int sk_rcvlowat; 357 struct sk_buff_head sk_error_queue; 358 struct sk_buff_head sk_receive_queue; 359 /* 360 * The backlog queue is special, it is always used with 361 * the per-socket spinlock held and requires low latency 362 * access. Therefore we special case it's implementation. 363 * Note : rmem_alloc is in this structure to fill a hole 364 * on 64bit arches, not because its logically part of 365 * backlog. 366 */ 367 struct { 368 atomic_t rmem_alloc; 369 int len; 370 struct sk_buff *head; 371 struct sk_buff *tail; 372 } sk_backlog; 373 #define sk_rmem_alloc sk_backlog.rmem_alloc 374 375 int sk_forward_alloc; 376 #ifdef CONFIG_NET_RX_BUSY_POLL 377 unsigned int sk_ll_usec; 378 /* ===== mostly read cache line ===== */ 379 unsigned int sk_napi_id; 380 #endif 381 int sk_rcvbuf; 382 383 struct sk_filter __rcu *sk_filter; 384 union { 385 struct socket_wq __rcu *sk_wq; 386 struct socket_wq *sk_wq_raw; 387 }; 388 #ifdef CONFIG_XFRM 389 struct xfrm_policy __rcu *sk_policy[2]; 390 #endif 391 struct dst_entry *sk_rx_dst; 392 struct dst_entry __rcu *sk_dst_cache; 393 atomic_t sk_omem_alloc; 394 int sk_sndbuf; 395 396 /* ===== cache line for TX ===== */ 397 int sk_wmem_queued; 398 refcount_t sk_wmem_alloc; 399 unsigned long sk_tsq_flags; 400 union { 401 struct sk_buff *sk_send_head; 402 struct rb_root tcp_rtx_queue; 403 }; 404 struct sk_buff_head sk_write_queue; 405 __s32 sk_peek_off; 406 int sk_write_pending; 407 __u32 sk_dst_pending_confirm; 408 u32 sk_pacing_status; /* see enum sk_pacing */ 409 long sk_sndtimeo; 410 struct timer_list sk_timer; 411 __u32 sk_priority; 412 __u32 sk_mark; 413 u32 sk_pacing_rate; /* bytes per second */ 414 u32 sk_max_pacing_rate; 415 struct page_frag sk_frag; 416 netdev_features_t sk_route_caps; 417 netdev_features_t sk_route_nocaps; 418 int sk_gso_type; 419 unsigned int sk_gso_max_size; 420 gfp_t sk_allocation; 421 __u32 sk_txhash; 422 423 /* 424 * Because of non atomicity rules, all 425 * changes are protected by socket lock. 426 */ 427 unsigned int __sk_flags_offset[0]; 428 #ifdef __BIG_ENDIAN_BITFIELD 429 #define SK_FL_PROTO_SHIFT 16 430 #define SK_FL_PROTO_MASK 0x00ff0000 431 432 #define SK_FL_TYPE_SHIFT 0 433 #define SK_FL_TYPE_MASK 0x0000ffff 434 #else 435 #define SK_FL_PROTO_SHIFT 8 436 #define SK_FL_PROTO_MASK 0x0000ff00 437 438 #define SK_FL_TYPE_SHIFT 16 439 #define SK_FL_TYPE_MASK 0xffff0000 440 #endif 441 442 kmemcheck_bitfield_begin(flags); 443 unsigned int sk_padding : 1, 444 sk_kern_sock : 1, 445 sk_no_check_tx : 1, 446 sk_no_check_rx : 1, 447 sk_userlocks : 4, 448 sk_protocol : 8, 449 sk_type : 16; 450 #define SK_PROTOCOL_MAX U8_MAX 451 kmemcheck_bitfield_end(flags); 452 453 u16 sk_gso_max_segs; 454 unsigned long sk_lingertime; 455 struct proto *sk_prot_creator; 456 rwlock_t sk_callback_lock; 457 int sk_err, 458 sk_err_soft; 459 u32 sk_ack_backlog; 460 u32 sk_max_ack_backlog; 461 kuid_t sk_uid; 462 struct pid *sk_peer_pid; 463 const struct cred *sk_peer_cred; 464 long sk_rcvtimeo; 465 ktime_t sk_stamp; 466 u16 sk_tsflags; 467 u8 sk_shutdown; 468 u32 sk_tskey; 469 atomic_t sk_zckey; 470 struct socket *sk_socket; 471 void *sk_user_data; 472 #ifdef CONFIG_SECURITY 473 void *sk_security; 474 #endif 475 struct sock_cgroup_data sk_cgrp_data; 476 struct mem_cgroup *sk_memcg; 477 void (*sk_state_change)(struct sock *sk); 478 void (*sk_data_ready)(struct sock *sk); 479 void (*sk_write_space)(struct sock *sk); 480 void (*sk_error_report)(struct sock *sk); 481 int (*sk_backlog_rcv)(struct sock *sk, 482 struct sk_buff *skb); 483 void (*sk_destruct)(struct sock *sk); 484 struct sock_reuseport __rcu *sk_reuseport_cb; 485 struct rcu_head sk_rcu; 486 }; 487 488 enum sk_pacing { 489 SK_PACING_NONE = 0, 490 SK_PACING_NEEDED = 1, 491 SK_PACING_FQ = 2, 492 }; 493 494 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) 495 496 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) 497 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) 498 499 /* 500 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 501 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 502 * on a socket means that the socket will reuse everybody else's port 503 * without looking at the other's sk_reuse value. 504 */ 505 506 #define SK_NO_REUSE 0 507 #define SK_CAN_REUSE 1 508 #define SK_FORCE_REUSE 2 509 510 int sk_set_peek_off(struct sock *sk, int val); 511 512 static inline int sk_peek_offset(struct sock *sk, int flags) 513 { 514 if (unlikely(flags & MSG_PEEK)) { 515 return READ_ONCE(sk->sk_peek_off); 516 } 517 518 return 0; 519 } 520 521 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 522 { 523 s32 off = READ_ONCE(sk->sk_peek_off); 524 525 if (unlikely(off >= 0)) { 526 off = max_t(s32, off - val, 0); 527 WRITE_ONCE(sk->sk_peek_off, off); 528 } 529 } 530 531 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 532 { 533 sk_peek_offset_bwd(sk, -val); 534 } 535 536 /* 537 * Hashed lists helper routines 538 */ 539 static inline struct sock *sk_entry(const struct hlist_node *node) 540 { 541 return hlist_entry(node, struct sock, sk_node); 542 } 543 544 static inline struct sock *__sk_head(const struct hlist_head *head) 545 { 546 return hlist_entry(head->first, struct sock, sk_node); 547 } 548 549 static inline struct sock *sk_head(const struct hlist_head *head) 550 { 551 return hlist_empty(head) ? NULL : __sk_head(head); 552 } 553 554 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 555 { 556 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 557 } 558 559 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 560 { 561 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 562 } 563 564 static inline struct sock *sk_next(const struct sock *sk) 565 { 566 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node); 567 } 568 569 static inline struct sock *sk_nulls_next(const struct sock *sk) 570 { 571 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 572 hlist_nulls_entry(sk->sk_nulls_node.next, 573 struct sock, sk_nulls_node) : 574 NULL; 575 } 576 577 static inline bool sk_unhashed(const struct sock *sk) 578 { 579 return hlist_unhashed(&sk->sk_node); 580 } 581 582 static inline bool sk_hashed(const struct sock *sk) 583 { 584 return !sk_unhashed(sk); 585 } 586 587 static inline void sk_node_init(struct hlist_node *node) 588 { 589 node->pprev = NULL; 590 } 591 592 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 593 { 594 node->pprev = NULL; 595 } 596 597 static inline void __sk_del_node(struct sock *sk) 598 { 599 __hlist_del(&sk->sk_node); 600 } 601 602 /* NB: equivalent to hlist_del_init_rcu */ 603 static inline bool __sk_del_node_init(struct sock *sk) 604 { 605 if (sk_hashed(sk)) { 606 __sk_del_node(sk); 607 sk_node_init(&sk->sk_node); 608 return true; 609 } 610 return false; 611 } 612 613 /* Grab socket reference count. This operation is valid only 614 when sk is ALREADY grabbed f.e. it is found in hash table 615 or a list and the lookup is made under lock preventing hash table 616 modifications. 617 */ 618 619 static __always_inline void sock_hold(struct sock *sk) 620 { 621 refcount_inc(&sk->sk_refcnt); 622 } 623 624 /* Ungrab socket in the context, which assumes that socket refcnt 625 cannot hit zero, f.e. it is true in context of any socketcall. 626 */ 627 static __always_inline void __sock_put(struct sock *sk) 628 { 629 refcount_dec(&sk->sk_refcnt); 630 } 631 632 static inline bool sk_del_node_init(struct sock *sk) 633 { 634 bool rc = __sk_del_node_init(sk); 635 636 if (rc) { 637 /* paranoid for a while -acme */ 638 WARN_ON(refcount_read(&sk->sk_refcnt) == 1); 639 __sock_put(sk); 640 } 641 return rc; 642 } 643 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 644 645 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 646 { 647 if (sk_hashed(sk)) { 648 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 649 return true; 650 } 651 return false; 652 } 653 654 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 655 { 656 bool rc = __sk_nulls_del_node_init_rcu(sk); 657 658 if (rc) { 659 /* paranoid for a while -acme */ 660 WARN_ON(refcount_read(&sk->sk_refcnt) == 1); 661 __sock_put(sk); 662 } 663 return rc; 664 } 665 666 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 667 { 668 hlist_add_head(&sk->sk_node, list); 669 } 670 671 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 672 { 673 sock_hold(sk); 674 __sk_add_node(sk, list); 675 } 676 677 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 678 { 679 sock_hold(sk); 680 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 681 sk->sk_family == AF_INET6) 682 hlist_add_tail_rcu(&sk->sk_node, list); 683 else 684 hlist_add_head_rcu(&sk->sk_node, list); 685 } 686 687 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 688 { 689 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 690 sk->sk_family == AF_INET6) 691 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list); 692 else 693 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 694 } 695 696 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 697 { 698 sock_hold(sk); 699 __sk_nulls_add_node_rcu(sk, list); 700 } 701 702 static inline void __sk_del_bind_node(struct sock *sk) 703 { 704 __hlist_del(&sk->sk_bind_node); 705 } 706 707 static inline void sk_add_bind_node(struct sock *sk, 708 struct hlist_head *list) 709 { 710 hlist_add_head(&sk->sk_bind_node, list); 711 } 712 713 #define sk_for_each(__sk, list) \ 714 hlist_for_each_entry(__sk, list, sk_node) 715 #define sk_for_each_rcu(__sk, list) \ 716 hlist_for_each_entry_rcu(__sk, list, sk_node) 717 #define sk_nulls_for_each(__sk, node, list) \ 718 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 719 #define sk_nulls_for_each_rcu(__sk, node, list) \ 720 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 721 #define sk_for_each_from(__sk) \ 722 hlist_for_each_entry_from(__sk, sk_node) 723 #define sk_nulls_for_each_from(__sk, node) \ 724 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 725 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 726 #define sk_for_each_safe(__sk, tmp, list) \ 727 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 728 #define sk_for_each_bound(__sk, list) \ 729 hlist_for_each_entry(__sk, list, sk_bind_node) 730 731 /** 732 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset 733 * @tpos: the type * to use as a loop cursor. 734 * @pos: the &struct hlist_node to use as a loop cursor. 735 * @head: the head for your list. 736 * @offset: offset of hlist_node within the struct. 737 * 738 */ 739 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \ 740 for (pos = rcu_dereference(hlist_first_rcu(head)); \ 741 pos != NULL && \ 742 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 743 pos = rcu_dereference(hlist_next_rcu(pos))) 744 745 static inline struct user_namespace *sk_user_ns(struct sock *sk) 746 { 747 /* Careful only use this in a context where these parameters 748 * can not change and must all be valid, such as recvmsg from 749 * userspace. 750 */ 751 return sk->sk_socket->file->f_cred->user_ns; 752 } 753 754 /* Sock flags */ 755 enum sock_flags { 756 SOCK_DEAD, 757 SOCK_DONE, 758 SOCK_URGINLINE, 759 SOCK_KEEPOPEN, 760 SOCK_LINGER, 761 SOCK_DESTROY, 762 SOCK_BROADCAST, 763 SOCK_TIMESTAMP, 764 SOCK_ZAPPED, 765 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 766 SOCK_DBG, /* %SO_DEBUG setting */ 767 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 768 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 769 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 770 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 771 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 772 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 773 SOCK_FASYNC, /* fasync() active */ 774 SOCK_RXQ_OVFL, 775 SOCK_ZEROCOPY, /* buffers from userspace */ 776 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 777 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 778 * Will use last 4 bytes of packet sent from 779 * user-space instead. 780 */ 781 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 782 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 783 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */ 784 }; 785 786 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) 787 788 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 789 { 790 nsk->sk_flags = osk->sk_flags; 791 } 792 793 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 794 { 795 __set_bit(flag, &sk->sk_flags); 796 } 797 798 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 799 { 800 __clear_bit(flag, &sk->sk_flags); 801 } 802 803 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 804 { 805 return test_bit(flag, &sk->sk_flags); 806 } 807 808 #ifdef CONFIG_NET 809 extern struct static_key memalloc_socks; 810 static inline int sk_memalloc_socks(void) 811 { 812 return static_key_false(&memalloc_socks); 813 } 814 #else 815 816 static inline int sk_memalloc_socks(void) 817 { 818 return 0; 819 } 820 821 #endif 822 823 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 824 { 825 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC); 826 } 827 828 static inline void sk_acceptq_removed(struct sock *sk) 829 { 830 sk->sk_ack_backlog--; 831 } 832 833 static inline void sk_acceptq_added(struct sock *sk) 834 { 835 sk->sk_ack_backlog++; 836 } 837 838 static inline bool sk_acceptq_is_full(const struct sock *sk) 839 { 840 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 841 } 842 843 /* 844 * Compute minimal free write space needed to queue new packets. 845 */ 846 static inline int sk_stream_min_wspace(const struct sock *sk) 847 { 848 return sk->sk_wmem_queued >> 1; 849 } 850 851 static inline int sk_stream_wspace(const struct sock *sk) 852 { 853 return sk->sk_sndbuf - sk->sk_wmem_queued; 854 } 855 856 void sk_stream_write_space(struct sock *sk); 857 858 /* OOB backlog add */ 859 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 860 { 861 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 862 skb_dst_force(skb); 863 864 if (!sk->sk_backlog.tail) 865 sk->sk_backlog.head = skb; 866 else 867 sk->sk_backlog.tail->next = skb; 868 869 sk->sk_backlog.tail = skb; 870 skb->next = NULL; 871 } 872 873 /* 874 * Take into account size of receive queue and backlog queue 875 * Do not take into account this skb truesize, 876 * to allow even a single big packet to come. 877 */ 878 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 879 { 880 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 881 882 return qsize > limit; 883 } 884 885 /* The per-socket spinlock must be held here. */ 886 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 887 unsigned int limit) 888 { 889 if (sk_rcvqueues_full(sk, limit)) 890 return -ENOBUFS; 891 892 /* 893 * If the skb was allocated from pfmemalloc reserves, only 894 * allow SOCK_MEMALLOC sockets to use it as this socket is 895 * helping free memory 896 */ 897 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 898 return -ENOMEM; 899 900 __sk_add_backlog(sk, skb); 901 sk->sk_backlog.len += skb->truesize; 902 return 0; 903 } 904 905 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 906 907 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 908 { 909 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 910 return __sk_backlog_rcv(sk, skb); 911 912 return sk->sk_backlog_rcv(sk, skb); 913 } 914 915 static inline void sk_incoming_cpu_update(struct sock *sk) 916 { 917 int cpu = raw_smp_processor_id(); 918 919 if (unlikely(sk->sk_incoming_cpu != cpu)) 920 sk->sk_incoming_cpu = cpu; 921 } 922 923 static inline void sock_rps_record_flow_hash(__u32 hash) 924 { 925 #ifdef CONFIG_RPS 926 struct rps_sock_flow_table *sock_flow_table; 927 928 rcu_read_lock(); 929 sock_flow_table = rcu_dereference(rps_sock_flow_table); 930 rps_record_sock_flow(sock_flow_table, hash); 931 rcu_read_unlock(); 932 #endif 933 } 934 935 static inline void sock_rps_record_flow(const struct sock *sk) 936 { 937 #ifdef CONFIG_RPS 938 if (static_key_false(&rfs_needed)) { 939 /* Reading sk->sk_rxhash might incur an expensive cache line 940 * miss. 941 * 942 * TCP_ESTABLISHED does cover almost all states where RFS 943 * might be useful, and is cheaper [1] than testing : 944 * IPv4: inet_sk(sk)->inet_daddr 945 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr) 946 * OR an additional socket flag 947 * [1] : sk_state and sk_prot are in the same cache line. 948 */ 949 if (sk->sk_state == TCP_ESTABLISHED) 950 sock_rps_record_flow_hash(sk->sk_rxhash); 951 } 952 #endif 953 } 954 955 static inline void sock_rps_save_rxhash(struct sock *sk, 956 const struct sk_buff *skb) 957 { 958 #ifdef CONFIG_RPS 959 if (unlikely(sk->sk_rxhash != skb->hash)) 960 sk->sk_rxhash = skb->hash; 961 #endif 962 } 963 964 static inline void sock_rps_reset_rxhash(struct sock *sk) 965 { 966 #ifdef CONFIG_RPS 967 sk->sk_rxhash = 0; 968 #endif 969 } 970 971 #define sk_wait_event(__sk, __timeo, __condition, __wait) \ 972 ({ int __rc; \ 973 release_sock(__sk); \ 974 __rc = __condition; \ 975 if (!__rc) { \ 976 *(__timeo) = wait_woken(__wait, \ 977 TASK_INTERRUPTIBLE, \ 978 *(__timeo)); \ 979 } \ 980 sched_annotate_sleep(); \ 981 lock_sock(__sk); \ 982 __rc = __condition; \ 983 __rc; \ 984 }) 985 986 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 987 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 988 void sk_stream_wait_close(struct sock *sk, long timeo_p); 989 int sk_stream_error(struct sock *sk, int flags, int err); 990 void sk_stream_kill_queues(struct sock *sk); 991 void sk_set_memalloc(struct sock *sk); 992 void sk_clear_memalloc(struct sock *sk); 993 994 void __sk_flush_backlog(struct sock *sk); 995 996 static inline bool sk_flush_backlog(struct sock *sk) 997 { 998 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) { 999 __sk_flush_backlog(sk); 1000 return true; 1001 } 1002 return false; 1003 } 1004 1005 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 1006 1007 struct request_sock_ops; 1008 struct timewait_sock_ops; 1009 struct inet_hashinfo; 1010 struct raw_hashinfo; 1011 struct smc_hashinfo; 1012 struct module; 1013 1014 /* 1015 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes 1016 * un-modified. Special care is taken when initializing object to zero. 1017 */ 1018 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 1019 { 1020 if (offsetof(struct sock, sk_node.next) != 0) 1021 memset(sk, 0, offsetof(struct sock, sk_node.next)); 1022 memset(&sk->sk_node.pprev, 0, 1023 size - offsetof(struct sock, sk_node.pprev)); 1024 } 1025 1026 /* Networking protocol blocks we attach to sockets. 1027 * socket layer -> transport layer interface 1028 */ 1029 struct proto { 1030 void (*close)(struct sock *sk, 1031 long timeout); 1032 int (*connect)(struct sock *sk, 1033 struct sockaddr *uaddr, 1034 int addr_len); 1035 int (*disconnect)(struct sock *sk, int flags); 1036 1037 struct sock * (*accept)(struct sock *sk, int flags, int *err, 1038 bool kern); 1039 1040 int (*ioctl)(struct sock *sk, int cmd, 1041 unsigned long arg); 1042 int (*init)(struct sock *sk); 1043 void (*destroy)(struct sock *sk); 1044 void (*shutdown)(struct sock *sk, int how); 1045 int (*setsockopt)(struct sock *sk, int level, 1046 int optname, char __user *optval, 1047 unsigned int optlen); 1048 int (*getsockopt)(struct sock *sk, int level, 1049 int optname, char __user *optval, 1050 int __user *option); 1051 void (*keepalive)(struct sock *sk, int valbool); 1052 #ifdef CONFIG_COMPAT 1053 int (*compat_setsockopt)(struct sock *sk, 1054 int level, 1055 int optname, char __user *optval, 1056 unsigned int optlen); 1057 int (*compat_getsockopt)(struct sock *sk, 1058 int level, 1059 int optname, char __user *optval, 1060 int __user *option); 1061 int (*compat_ioctl)(struct sock *sk, 1062 unsigned int cmd, unsigned long arg); 1063 #endif 1064 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 1065 size_t len); 1066 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 1067 size_t len, int noblock, int flags, 1068 int *addr_len); 1069 int (*sendpage)(struct sock *sk, struct page *page, 1070 int offset, size_t size, int flags); 1071 int (*bind)(struct sock *sk, 1072 struct sockaddr *uaddr, int addr_len); 1073 1074 int (*backlog_rcv) (struct sock *sk, 1075 struct sk_buff *skb); 1076 1077 void (*release_cb)(struct sock *sk); 1078 1079 /* Keeping track of sk's, looking them up, and port selection methods. */ 1080 int (*hash)(struct sock *sk); 1081 void (*unhash)(struct sock *sk); 1082 void (*rehash)(struct sock *sk); 1083 int (*get_port)(struct sock *sk, unsigned short snum); 1084 1085 /* Keeping track of sockets in use */ 1086 #ifdef CONFIG_PROC_FS 1087 unsigned int inuse_idx; 1088 #endif 1089 1090 bool (*stream_memory_free)(const struct sock *sk); 1091 /* Memory pressure */ 1092 void (*enter_memory_pressure)(struct sock *sk); 1093 void (*leave_memory_pressure)(struct sock *sk); 1094 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1095 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1096 /* 1097 * Pressure flag: try to collapse. 1098 * Technical note: it is used by multiple contexts non atomically. 1099 * All the __sk_mem_schedule() is of this nature: accounting 1100 * is strict, actions are advisory and have some latency. 1101 */ 1102 unsigned long *memory_pressure; 1103 long *sysctl_mem; 1104 int *sysctl_wmem; 1105 int *sysctl_rmem; 1106 int max_header; 1107 bool no_autobind; 1108 1109 struct kmem_cache *slab; 1110 unsigned int obj_size; 1111 int slab_flags; 1112 1113 struct percpu_counter *orphan_count; 1114 1115 struct request_sock_ops *rsk_prot; 1116 struct timewait_sock_ops *twsk_prot; 1117 1118 union { 1119 struct inet_hashinfo *hashinfo; 1120 struct udp_table *udp_table; 1121 struct raw_hashinfo *raw_hash; 1122 struct smc_hashinfo *smc_hash; 1123 } h; 1124 1125 struct module *owner; 1126 1127 char name[32]; 1128 1129 struct list_head node; 1130 #ifdef SOCK_REFCNT_DEBUG 1131 atomic_t socks; 1132 #endif 1133 int (*diag_destroy)(struct sock *sk, int err); 1134 } __randomize_layout; 1135 1136 int proto_register(struct proto *prot, int alloc_slab); 1137 void proto_unregister(struct proto *prot); 1138 1139 #ifdef SOCK_REFCNT_DEBUG 1140 static inline void sk_refcnt_debug_inc(struct sock *sk) 1141 { 1142 atomic_inc(&sk->sk_prot->socks); 1143 } 1144 1145 static inline void sk_refcnt_debug_dec(struct sock *sk) 1146 { 1147 atomic_dec(&sk->sk_prot->socks); 1148 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1149 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1150 } 1151 1152 static inline void sk_refcnt_debug_release(const struct sock *sk) 1153 { 1154 if (refcount_read(&sk->sk_refcnt) != 1) 1155 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1156 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt)); 1157 } 1158 #else /* SOCK_REFCNT_DEBUG */ 1159 #define sk_refcnt_debug_inc(sk) do { } while (0) 1160 #define sk_refcnt_debug_dec(sk) do { } while (0) 1161 #define sk_refcnt_debug_release(sk) do { } while (0) 1162 #endif /* SOCK_REFCNT_DEBUG */ 1163 1164 static inline bool sk_stream_memory_free(const struct sock *sk) 1165 { 1166 if (sk->sk_wmem_queued >= sk->sk_sndbuf) 1167 return false; 1168 1169 return sk->sk_prot->stream_memory_free ? 1170 sk->sk_prot->stream_memory_free(sk) : true; 1171 } 1172 1173 static inline bool sk_stream_is_writeable(const struct sock *sk) 1174 { 1175 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1176 sk_stream_memory_free(sk); 1177 } 1178 1179 static inline int sk_under_cgroup_hierarchy(struct sock *sk, 1180 struct cgroup *ancestor) 1181 { 1182 #ifdef CONFIG_SOCK_CGROUP_DATA 1183 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), 1184 ancestor); 1185 #else 1186 return -ENOTSUPP; 1187 #endif 1188 } 1189 1190 static inline bool sk_has_memory_pressure(const struct sock *sk) 1191 { 1192 return sk->sk_prot->memory_pressure != NULL; 1193 } 1194 1195 static inline bool sk_under_memory_pressure(const struct sock *sk) 1196 { 1197 if (!sk->sk_prot->memory_pressure) 1198 return false; 1199 1200 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 1201 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 1202 return true; 1203 1204 return !!*sk->sk_prot->memory_pressure; 1205 } 1206 1207 static inline long 1208 sk_memory_allocated(const struct sock *sk) 1209 { 1210 return atomic_long_read(sk->sk_prot->memory_allocated); 1211 } 1212 1213 static inline long 1214 sk_memory_allocated_add(struct sock *sk, int amt) 1215 { 1216 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated); 1217 } 1218 1219 static inline void 1220 sk_memory_allocated_sub(struct sock *sk, int amt) 1221 { 1222 atomic_long_sub(amt, sk->sk_prot->memory_allocated); 1223 } 1224 1225 static inline void sk_sockets_allocated_dec(struct sock *sk) 1226 { 1227 percpu_counter_dec(sk->sk_prot->sockets_allocated); 1228 } 1229 1230 static inline void sk_sockets_allocated_inc(struct sock *sk) 1231 { 1232 percpu_counter_inc(sk->sk_prot->sockets_allocated); 1233 } 1234 1235 static inline int 1236 sk_sockets_allocated_read_positive(struct sock *sk) 1237 { 1238 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated); 1239 } 1240 1241 static inline int 1242 proto_sockets_allocated_sum_positive(struct proto *prot) 1243 { 1244 return percpu_counter_sum_positive(prot->sockets_allocated); 1245 } 1246 1247 static inline long 1248 proto_memory_allocated(struct proto *prot) 1249 { 1250 return atomic_long_read(prot->memory_allocated); 1251 } 1252 1253 static inline bool 1254 proto_memory_pressure(struct proto *prot) 1255 { 1256 if (!prot->memory_pressure) 1257 return false; 1258 return !!*prot->memory_pressure; 1259 } 1260 1261 1262 #ifdef CONFIG_PROC_FS 1263 /* Called with local bh disabled */ 1264 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1265 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1266 #else 1267 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1268 int inc) 1269 { 1270 } 1271 #endif 1272 1273 1274 /* With per-bucket locks this operation is not-atomic, so that 1275 * this version is not worse. 1276 */ 1277 static inline int __sk_prot_rehash(struct sock *sk) 1278 { 1279 sk->sk_prot->unhash(sk); 1280 return sk->sk_prot->hash(sk); 1281 } 1282 1283 /* About 10 seconds */ 1284 #define SOCK_DESTROY_TIME (10*HZ) 1285 1286 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1287 #define PROT_SOCK 1024 1288 1289 #define SHUTDOWN_MASK 3 1290 #define RCV_SHUTDOWN 1 1291 #define SEND_SHUTDOWN 2 1292 1293 #define SOCK_SNDBUF_LOCK 1 1294 #define SOCK_RCVBUF_LOCK 2 1295 #define SOCK_BINDADDR_LOCK 4 1296 #define SOCK_BINDPORT_LOCK 8 1297 1298 struct socket_alloc { 1299 struct socket socket; 1300 struct inode vfs_inode; 1301 }; 1302 1303 static inline struct socket *SOCKET_I(struct inode *inode) 1304 { 1305 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1306 } 1307 1308 static inline struct inode *SOCK_INODE(struct socket *socket) 1309 { 1310 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1311 } 1312 1313 /* 1314 * Functions for memory accounting 1315 */ 1316 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind); 1317 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1318 void __sk_mem_reduce_allocated(struct sock *sk, int amount); 1319 void __sk_mem_reclaim(struct sock *sk, int amount); 1320 1321 /* We used to have PAGE_SIZE here, but systems with 64KB pages 1322 * do not necessarily have 16x time more memory than 4KB ones. 1323 */ 1324 #define SK_MEM_QUANTUM 4096 1325 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1326 #define SK_MEM_SEND 0 1327 #define SK_MEM_RECV 1 1328 1329 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */ 1330 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1331 { 1332 long val = sk->sk_prot->sysctl_mem[index]; 1333 1334 #if PAGE_SIZE > SK_MEM_QUANTUM 1335 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT; 1336 #elif PAGE_SIZE < SK_MEM_QUANTUM 1337 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT; 1338 #endif 1339 return val; 1340 } 1341 1342 static inline int sk_mem_pages(int amt) 1343 { 1344 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1345 } 1346 1347 static inline bool sk_has_account(struct sock *sk) 1348 { 1349 /* return true if protocol supports memory accounting */ 1350 return !!sk->sk_prot->memory_allocated; 1351 } 1352 1353 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1354 { 1355 if (!sk_has_account(sk)) 1356 return true; 1357 return size <= sk->sk_forward_alloc || 1358 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1359 } 1360 1361 static inline bool 1362 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1363 { 1364 if (!sk_has_account(sk)) 1365 return true; 1366 return size<= sk->sk_forward_alloc || 1367 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1368 skb_pfmemalloc(skb); 1369 } 1370 1371 static inline void sk_mem_reclaim(struct sock *sk) 1372 { 1373 if (!sk_has_account(sk)) 1374 return; 1375 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1376 __sk_mem_reclaim(sk, sk->sk_forward_alloc); 1377 } 1378 1379 static inline void sk_mem_reclaim_partial(struct sock *sk) 1380 { 1381 if (!sk_has_account(sk)) 1382 return; 1383 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1384 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); 1385 } 1386 1387 static inline void sk_mem_charge(struct sock *sk, int size) 1388 { 1389 if (!sk_has_account(sk)) 1390 return; 1391 sk->sk_forward_alloc -= size; 1392 } 1393 1394 static inline void sk_mem_uncharge(struct sock *sk, int size) 1395 { 1396 if (!sk_has_account(sk)) 1397 return; 1398 sk->sk_forward_alloc += size; 1399 1400 /* Avoid a possible overflow. 1401 * TCP send queues can make this happen, if sk_mem_reclaim() 1402 * is not called and more than 2 GBytes are released at once. 1403 * 1404 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is 1405 * no need to hold that much forward allocation anyway. 1406 */ 1407 if (unlikely(sk->sk_forward_alloc >= 1 << 21)) 1408 __sk_mem_reclaim(sk, 1 << 20); 1409 } 1410 1411 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1412 { 1413 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1414 sk->sk_wmem_queued -= skb->truesize; 1415 sk_mem_uncharge(sk, skb->truesize); 1416 __kfree_skb(skb); 1417 } 1418 1419 static inline void sock_release_ownership(struct sock *sk) 1420 { 1421 if (sk->sk_lock.owned) { 1422 sk->sk_lock.owned = 0; 1423 1424 /* The sk_lock has mutex_unlock() semantics: */ 1425 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_); 1426 } 1427 } 1428 1429 /* 1430 * Macro so as to not evaluate some arguments when 1431 * lockdep is not enabled. 1432 * 1433 * Mark both the sk_lock and the sk_lock.slock as a 1434 * per-address-family lock class. 1435 */ 1436 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1437 do { \ 1438 sk->sk_lock.owned = 0; \ 1439 init_waitqueue_head(&sk->sk_lock.wq); \ 1440 spin_lock_init(&(sk)->sk_lock.slock); \ 1441 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1442 sizeof((sk)->sk_lock)); \ 1443 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1444 (skey), (sname)); \ 1445 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1446 } while (0) 1447 1448 #ifdef CONFIG_LOCKDEP 1449 static inline bool lockdep_sock_is_held(const struct sock *csk) 1450 { 1451 struct sock *sk = (struct sock *)csk; 1452 1453 return lockdep_is_held(&sk->sk_lock) || 1454 lockdep_is_held(&sk->sk_lock.slock); 1455 } 1456 #endif 1457 1458 void lock_sock_nested(struct sock *sk, int subclass); 1459 1460 static inline void lock_sock(struct sock *sk) 1461 { 1462 lock_sock_nested(sk, 0); 1463 } 1464 1465 void release_sock(struct sock *sk); 1466 1467 /* BH context may only use the following locking interface. */ 1468 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1469 #define bh_lock_sock_nested(__sk) \ 1470 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1471 SINGLE_DEPTH_NESTING) 1472 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1473 1474 bool lock_sock_fast(struct sock *sk); 1475 /** 1476 * unlock_sock_fast - complement of lock_sock_fast 1477 * @sk: socket 1478 * @slow: slow mode 1479 * 1480 * fast unlock socket for user context. 1481 * If slow mode is on, we call regular release_sock() 1482 */ 1483 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1484 { 1485 if (slow) 1486 release_sock(sk); 1487 else 1488 spin_unlock_bh(&sk->sk_lock.slock); 1489 } 1490 1491 /* Used by processes to "lock" a socket state, so that 1492 * interrupts and bottom half handlers won't change it 1493 * from under us. It essentially blocks any incoming 1494 * packets, so that we won't get any new data or any 1495 * packets that change the state of the socket. 1496 * 1497 * While locked, BH processing will add new packets to 1498 * the backlog queue. This queue is processed by the 1499 * owner of the socket lock right before it is released. 1500 * 1501 * Since ~2.3.5 it is also exclusive sleep lock serializing 1502 * accesses from user process context. 1503 */ 1504 1505 static inline void sock_owned_by_me(const struct sock *sk) 1506 { 1507 #ifdef CONFIG_LOCKDEP 1508 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks); 1509 #endif 1510 } 1511 1512 static inline bool sock_owned_by_user(const struct sock *sk) 1513 { 1514 sock_owned_by_me(sk); 1515 return sk->sk_lock.owned; 1516 } 1517 1518 /* no reclassification while locks are held */ 1519 static inline bool sock_allow_reclassification(const struct sock *csk) 1520 { 1521 struct sock *sk = (struct sock *)csk; 1522 1523 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock); 1524 } 1525 1526 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1527 struct proto *prot, int kern); 1528 void sk_free(struct sock *sk); 1529 void sk_destruct(struct sock *sk); 1530 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1531 void sk_free_unlock_clone(struct sock *sk); 1532 1533 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1534 gfp_t priority); 1535 void __sock_wfree(struct sk_buff *skb); 1536 void sock_wfree(struct sk_buff *skb); 1537 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size, 1538 gfp_t priority); 1539 void skb_orphan_partial(struct sk_buff *skb); 1540 void sock_rfree(struct sk_buff *skb); 1541 void sock_efree(struct sk_buff *skb); 1542 #ifdef CONFIG_INET 1543 void sock_edemux(struct sk_buff *skb); 1544 #else 1545 #define sock_edemux sock_efree 1546 #endif 1547 1548 int sock_setsockopt(struct socket *sock, int level, int op, 1549 char __user *optval, unsigned int optlen); 1550 1551 int sock_getsockopt(struct socket *sock, int level, int op, 1552 char __user *optval, int __user *optlen); 1553 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1554 int noblock, int *errcode); 1555 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1556 unsigned long data_len, int noblock, 1557 int *errcode, int max_page_order); 1558 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1559 void sock_kfree_s(struct sock *sk, void *mem, int size); 1560 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1561 void sk_send_sigurg(struct sock *sk); 1562 1563 struct sockcm_cookie { 1564 u32 mark; 1565 u16 tsflags; 1566 }; 1567 1568 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg, 1569 struct sockcm_cookie *sockc); 1570 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1571 struct sockcm_cookie *sockc); 1572 1573 /* 1574 * Functions to fill in entries in struct proto_ops when a protocol 1575 * does not implement a particular function. 1576 */ 1577 int sock_no_bind(struct socket *, struct sockaddr *, int); 1578 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1579 int sock_no_socketpair(struct socket *, struct socket *); 1580 int sock_no_accept(struct socket *, struct socket *, int, bool); 1581 int sock_no_getname(struct socket *, struct sockaddr *, int *, int); 1582 unsigned int sock_no_poll(struct file *, struct socket *, 1583 struct poll_table_struct *); 1584 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1585 int sock_no_listen(struct socket *, int); 1586 int sock_no_shutdown(struct socket *, int); 1587 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *); 1588 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int); 1589 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1590 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len); 1591 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1592 int sock_no_mmap(struct file *file, struct socket *sock, 1593 struct vm_area_struct *vma); 1594 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1595 size_t size, int flags); 1596 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page, 1597 int offset, size_t size, int flags); 1598 1599 /* 1600 * Functions to fill in entries in struct proto_ops when a protocol 1601 * uses the inet style. 1602 */ 1603 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1604 char __user *optval, int __user *optlen); 1605 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1606 int flags); 1607 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1608 char __user *optval, unsigned int optlen); 1609 int compat_sock_common_getsockopt(struct socket *sock, int level, 1610 int optname, char __user *optval, int __user *optlen); 1611 int compat_sock_common_setsockopt(struct socket *sock, int level, 1612 int optname, char __user *optval, unsigned int optlen); 1613 1614 void sk_common_release(struct sock *sk); 1615 1616 /* 1617 * Default socket callbacks and setup code 1618 */ 1619 1620 /* Initialise core socket variables */ 1621 void sock_init_data(struct socket *sock, struct sock *sk); 1622 1623 /* 1624 * Socket reference counting postulates. 1625 * 1626 * * Each user of socket SHOULD hold a reference count. 1627 * * Each access point to socket (an hash table bucket, reference from a list, 1628 * running timer, skb in flight MUST hold a reference count. 1629 * * When reference count hits 0, it means it will never increase back. 1630 * * When reference count hits 0, it means that no references from 1631 * outside exist to this socket and current process on current CPU 1632 * is last user and may/should destroy this socket. 1633 * * sk_free is called from any context: process, BH, IRQ. When 1634 * it is called, socket has no references from outside -> sk_free 1635 * may release descendant resources allocated by the socket, but 1636 * to the time when it is called, socket is NOT referenced by any 1637 * hash tables, lists etc. 1638 * * Packets, delivered from outside (from network or from another process) 1639 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1640 * when they sit in queue. Otherwise, packets will leak to hole, when 1641 * socket is looked up by one cpu and unhasing is made by another CPU. 1642 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1643 * (leak to backlog). Packet socket does all the processing inside 1644 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1645 * use separate SMP lock, so that they are prone too. 1646 */ 1647 1648 /* Ungrab socket and destroy it, if it was the last reference. */ 1649 static inline void sock_put(struct sock *sk) 1650 { 1651 if (refcount_dec_and_test(&sk->sk_refcnt)) 1652 sk_free(sk); 1653 } 1654 /* Generic version of sock_put(), dealing with all sockets 1655 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1656 */ 1657 void sock_gen_put(struct sock *sk); 1658 1659 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested, 1660 unsigned int trim_cap, bool refcounted); 1661 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1662 const int nested) 1663 { 1664 return __sk_receive_skb(sk, skb, nested, 1, true); 1665 } 1666 1667 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1668 { 1669 sk->sk_tx_queue_mapping = tx_queue; 1670 } 1671 1672 static inline void sk_tx_queue_clear(struct sock *sk) 1673 { 1674 sk->sk_tx_queue_mapping = -1; 1675 } 1676 1677 static inline int sk_tx_queue_get(const struct sock *sk) 1678 { 1679 return sk ? sk->sk_tx_queue_mapping : -1; 1680 } 1681 1682 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1683 { 1684 sk_tx_queue_clear(sk); 1685 sk->sk_socket = sock; 1686 } 1687 1688 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1689 { 1690 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1691 return &rcu_dereference_raw(sk->sk_wq)->wait; 1692 } 1693 /* Detach socket from process context. 1694 * Announce socket dead, detach it from wait queue and inode. 1695 * Note that parent inode held reference count on this struct sock, 1696 * we do not release it in this function, because protocol 1697 * probably wants some additional cleanups or even continuing 1698 * to work with this socket (TCP). 1699 */ 1700 static inline void sock_orphan(struct sock *sk) 1701 { 1702 write_lock_bh(&sk->sk_callback_lock); 1703 sock_set_flag(sk, SOCK_DEAD); 1704 sk_set_socket(sk, NULL); 1705 sk->sk_wq = NULL; 1706 write_unlock_bh(&sk->sk_callback_lock); 1707 } 1708 1709 static inline void sock_graft(struct sock *sk, struct socket *parent) 1710 { 1711 WARN_ON(parent->sk); 1712 write_lock_bh(&sk->sk_callback_lock); 1713 sk->sk_wq = parent->wq; 1714 parent->sk = sk; 1715 sk_set_socket(sk, parent); 1716 sk->sk_uid = SOCK_INODE(parent)->i_uid; 1717 security_sock_graft(sk, parent); 1718 write_unlock_bh(&sk->sk_callback_lock); 1719 } 1720 1721 kuid_t sock_i_uid(struct sock *sk); 1722 unsigned long sock_i_ino(struct sock *sk); 1723 1724 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk) 1725 { 1726 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0); 1727 } 1728 1729 static inline u32 net_tx_rndhash(void) 1730 { 1731 u32 v = prandom_u32(); 1732 1733 return v ?: 1; 1734 } 1735 1736 static inline void sk_set_txhash(struct sock *sk) 1737 { 1738 sk->sk_txhash = net_tx_rndhash(); 1739 } 1740 1741 static inline void sk_rethink_txhash(struct sock *sk) 1742 { 1743 if (sk->sk_txhash) 1744 sk_set_txhash(sk); 1745 } 1746 1747 static inline struct dst_entry * 1748 __sk_dst_get(struct sock *sk) 1749 { 1750 return rcu_dereference_check(sk->sk_dst_cache, 1751 lockdep_sock_is_held(sk)); 1752 } 1753 1754 static inline struct dst_entry * 1755 sk_dst_get(struct sock *sk) 1756 { 1757 struct dst_entry *dst; 1758 1759 rcu_read_lock(); 1760 dst = rcu_dereference(sk->sk_dst_cache); 1761 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 1762 dst = NULL; 1763 rcu_read_unlock(); 1764 return dst; 1765 } 1766 1767 static inline void dst_negative_advice(struct sock *sk) 1768 { 1769 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1770 1771 sk_rethink_txhash(sk); 1772 1773 if (dst && dst->ops->negative_advice) { 1774 ndst = dst->ops->negative_advice(dst); 1775 1776 if (ndst != dst) { 1777 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1778 sk_tx_queue_clear(sk); 1779 sk->sk_dst_pending_confirm = 0; 1780 } 1781 } 1782 } 1783 1784 static inline void 1785 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1786 { 1787 struct dst_entry *old_dst; 1788 1789 sk_tx_queue_clear(sk); 1790 sk->sk_dst_pending_confirm = 0; 1791 old_dst = rcu_dereference_protected(sk->sk_dst_cache, 1792 lockdep_sock_is_held(sk)); 1793 rcu_assign_pointer(sk->sk_dst_cache, dst); 1794 dst_release(old_dst); 1795 } 1796 1797 static inline void 1798 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1799 { 1800 struct dst_entry *old_dst; 1801 1802 sk_tx_queue_clear(sk); 1803 sk->sk_dst_pending_confirm = 0; 1804 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 1805 dst_release(old_dst); 1806 } 1807 1808 static inline void 1809 __sk_dst_reset(struct sock *sk) 1810 { 1811 __sk_dst_set(sk, NULL); 1812 } 1813 1814 static inline void 1815 sk_dst_reset(struct sock *sk) 1816 { 1817 sk_dst_set(sk, NULL); 1818 } 1819 1820 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1821 1822 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1823 1824 static inline void sk_dst_confirm(struct sock *sk) 1825 { 1826 if (!sk->sk_dst_pending_confirm) 1827 sk->sk_dst_pending_confirm = 1; 1828 } 1829 1830 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n) 1831 { 1832 if (skb_get_dst_pending_confirm(skb)) { 1833 struct sock *sk = skb->sk; 1834 unsigned long now = jiffies; 1835 1836 /* avoid dirtying neighbour */ 1837 if (n->confirmed != now) 1838 n->confirmed = now; 1839 if (sk && sk->sk_dst_pending_confirm) 1840 sk->sk_dst_pending_confirm = 0; 1841 } 1842 } 1843 1844 bool sk_mc_loop(struct sock *sk); 1845 1846 static inline bool sk_can_gso(const struct sock *sk) 1847 { 1848 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1849 } 1850 1851 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1852 1853 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1854 { 1855 sk->sk_route_nocaps |= flags; 1856 sk->sk_route_caps &= ~flags; 1857 } 1858 1859 static inline bool sk_check_csum_caps(struct sock *sk) 1860 { 1861 return (sk->sk_route_caps & NETIF_F_HW_CSUM) || 1862 (sk->sk_family == PF_INET && 1863 (sk->sk_route_caps & NETIF_F_IP_CSUM)) || 1864 (sk->sk_family == PF_INET6 && 1865 (sk->sk_route_caps & NETIF_F_IPV6_CSUM)); 1866 } 1867 1868 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1869 struct iov_iter *from, char *to, 1870 int copy, int offset) 1871 { 1872 if (skb->ip_summed == CHECKSUM_NONE) { 1873 __wsum csum = 0; 1874 if (!csum_and_copy_from_iter_full(to, copy, &csum, from)) 1875 return -EFAULT; 1876 skb->csum = csum_block_add(skb->csum, csum, offset); 1877 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1878 if (!copy_from_iter_full_nocache(to, copy, from)) 1879 return -EFAULT; 1880 } else if (!copy_from_iter_full(to, copy, from)) 1881 return -EFAULT; 1882 1883 return 0; 1884 } 1885 1886 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1887 struct iov_iter *from, int copy) 1888 { 1889 int err, offset = skb->len; 1890 1891 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1892 copy, offset); 1893 if (err) 1894 __skb_trim(skb, offset); 1895 1896 return err; 1897 } 1898 1899 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 1900 struct sk_buff *skb, 1901 struct page *page, 1902 int off, int copy) 1903 { 1904 int err; 1905 1906 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1907 copy, skb->len); 1908 if (err) 1909 return err; 1910 1911 skb->len += copy; 1912 skb->data_len += copy; 1913 skb->truesize += copy; 1914 sk->sk_wmem_queued += copy; 1915 sk_mem_charge(sk, copy); 1916 return 0; 1917 } 1918 1919 /** 1920 * sk_wmem_alloc_get - returns write allocations 1921 * @sk: socket 1922 * 1923 * Returns sk_wmem_alloc minus initial offset of one 1924 */ 1925 static inline int sk_wmem_alloc_get(const struct sock *sk) 1926 { 1927 return refcount_read(&sk->sk_wmem_alloc) - 1; 1928 } 1929 1930 /** 1931 * sk_rmem_alloc_get - returns read allocations 1932 * @sk: socket 1933 * 1934 * Returns sk_rmem_alloc 1935 */ 1936 static inline int sk_rmem_alloc_get(const struct sock *sk) 1937 { 1938 return atomic_read(&sk->sk_rmem_alloc); 1939 } 1940 1941 /** 1942 * sk_has_allocations - check if allocations are outstanding 1943 * @sk: socket 1944 * 1945 * Returns true if socket has write or read allocations 1946 */ 1947 static inline bool sk_has_allocations(const struct sock *sk) 1948 { 1949 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1950 } 1951 1952 /** 1953 * skwq_has_sleeper - check if there are any waiting processes 1954 * @wq: struct socket_wq 1955 * 1956 * Returns true if socket_wq has waiting processes 1957 * 1958 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory 1959 * barrier call. They were added due to the race found within the tcp code. 1960 * 1961 * Consider following tcp code paths:: 1962 * 1963 * CPU1 CPU2 1964 * sys_select receive packet 1965 * ... ... 1966 * __add_wait_queue update tp->rcv_nxt 1967 * ... ... 1968 * tp->rcv_nxt check sock_def_readable 1969 * ... { 1970 * schedule rcu_read_lock(); 1971 * wq = rcu_dereference(sk->sk_wq); 1972 * if (wq && waitqueue_active(&wq->wait)) 1973 * wake_up_interruptible(&wq->wait) 1974 * ... 1975 * } 1976 * 1977 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1978 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1979 * could then endup calling schedule and sleep forever if there are no more 1980 * data on the socket. 1981 * 1982 */ 1983 static inline bool skwq_has_sleeper(struct socket_wq *wq) 1984 { 1985 return wq && wq_has_sleeper(&wq->wait); 1986 } 1987 1988 /** 1989 * sock_poll_wait - place memory barrier behind the poll_wait call. 1990 * @filp: file 1991 * @wait_address: socket wait queue 1992 * @p: poll_table 1993 * 1994 * See the comments in the wq_has_sleeper function. 1995 */ 1996 static inline void sock_poll_wait(struct file *filp, 1997 wait_queue_head_t *wait_address, poll_table *p) 1998 { 1999 if (!poll_does_not_wait(p) && wait_address) { 2000 poll_wait(filp, wait_address, p); 2001 /* We need to be sure we are in sync with the 2002 * socket flags modification. 2003 * 2004 * This memory barrier is paired in the wq_has_sleeper. 2005 */ 2006 smp_mb(); 2007 } 2008 } 2009 2010 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 2011 { 2012 if (sk->sk_txhash) { 2013 skb->l4_hash = 1; 2014 skb->hash = sk->sk_txhash; 2015 } 2016 } 2017 2018 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 2019 2020 /* 2021 * Queue a received datagram if it will fit. Stream and sequenced 2022 * protocols can't normally use this as they need to fit buffers in 2023 * and play with them. 2024 * 2025 * Inlined as it's very short and called for pretty much every 2026 * packet ever received. 2027 */ 2028 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 2029 { 2030 skb_orphan(skb); 2031 skb->sk = sk; 2032 skb->destructor = sock_rfree; 2033 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 2034 sk_mem_charge(sk, skb->truesize); 2035 } 2036 2037 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 2038 unsigned long expires); 2039 2040 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 2041 2042 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue, 2043 struct sk_buff *skb, unsigned int flags, 2044 void (*destructor)(struct sock *sk, 2045 struct sk_buff *skb)); 2046 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2047 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2048 2049 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 2050 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 2051 2052 /* 2053 * Recover an error report and clear atomically 2054 */ 2055 2056 static inline int sock_error(struct sock *sk) 2057 { 2058 int err; 2059 if (likely(!sk->sk_err)) 2060 return 0; 2061 err = xchg(&sk->sk_err, 0); 2062 return -err; 2063 } 2064 2065 static inline unsigned long sock_wspace(struct sock *sk) 2066 { 2067 int amt = 0; 2068 2069 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 2070 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc); 2071 if (amt < 0) 2072 amt = 0; 2073 } 2074 return amt; 2075 } 2076 2077 /* Note: 2078 * We use sk->sk_wq_raw, from contexts knowing this 2079 * pointer is not NULL and cannot disappear/change. 2080 */ 2081 static inline void sk_set_bit(int nr, struct sock *sk) 2082 { 2083 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2084 !sock_flag(sk, SOCK_FASYNC)) 2085 return; 2086 2087 set_bit(nr, &sk->sk_wq_raw->flags); 2088 } 2089 2090 static inline void sk_clear_bit(int nr, struct sock *sk) 2091 { 2092 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2093 !sock_flag(sk, SOCK_FASYNC)) 2094 return; 2095 2096 clear_bit(nr, &sk->sk_wq_raw->flags); 2097 } 2098 2099 static inline void sk_wake_async(const struct sock *sk, int how, int band) 2100 { 2101 if (sock_flag(sk, SOCK_FASYNC)) { 2102 rcu_read_lock(); 2103 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 2104 rcu_read_unlock(); 2105 } 2106 } 2107 2108 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 2109 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 2110 * Note: for send buffers, TCP works better if we can build two skbs at 2111 * minimum. 2112 */ 2113 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 2114 2115 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 2116 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 2117 2118 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 2119 { 2120 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 2121 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 2122 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); 2123 } 2124 } 2125 2126 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 2127 bool force_schedule); 2128 2129 /** 2130 * sk_page_frag - return an appropriate page_frag 2131 * @sk: socket 2132 * 2133 * If socket allocation mode allows current thread to sleep, it means its 2134 * safe to use the per task page_frag instead of the per socket one. 2135 */ 2136 static inline struct page_frag *sk_page_frag(struct sock *sk) 2137 { 2138 if (gfpflags_allow_blocking(sk->sk_allocation)) 2139 return ¤t->task_frag; 2140 2141 return &sk->sk_frag; 2142 } 2143 2144 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2145 2146 /* 2147 * Default write policy as shown to user space via poll/select/SIGIO 2148 */ 2149 static inline bool sock_writeable(const struct sock *sk) 2150 { 2151 return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 2152 } 2153 2154 static inline gfp_t gfp_any(void) 2155 { 2156 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2157 } 2158 2159 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2160 { 2161 return noblock ? 0 : sk->sk_rcvtimeo; 2162 } 2163 2164 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2165 { 2166 return noblock ? 0 : sk->sk_sndtimeo; 2167 } 2168 2169 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2170 { 2171 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 2172 } 2173 2174 /* Alas, with timeout socket operations are not restartable. 2175 * Compare this to poll(). 2176 */ 2177 static inline int sock_intr_errno(long timeo) 2178 { 2179 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2180 } 2181 2182 struct sock_skb_cb { 2183 u32 dropcount; 2184 }; 2185 2186 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2187 * using skb->cb[] would keep using it directly and utilize its 2188 * alignement guarantee. 2189 */ 2190 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \ 2191 sizeof(struct sock_skb_cb))) 2192 2193 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2194 SOCK_SKB_CB_OFFSET)) 2195 2196 #define sock_skb_cb_check_size(size) \ 2197 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2198 2199 static inline void 2200 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2201 { 2202 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ? 2203 atomic_read(&sk->sk_drops) : 0; 2204 } 2205 2206 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) 2207 { 2208 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2209 2210 atomic_add(segs, &sk->sk_drops); 2211 } 2212 2213 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2214 struct sk_buff *skb); 2215 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2216 struct sk_buff *skb); 2217 2218 static inline void 2219 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2220 { 2221 ktime_t kt = skb->tstamp; 2222 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2223 2224 /* 2225 * generate control messages if 2226 * - receive time stamping in software requested 2227 * - software time stamp available and wanted 2228 * - hardware time stamps available and wanted 2229 */ 2230 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2231 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2232 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2233 (hwtstamps->hwtstamp && 2234 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2235 __sock_recv_timestamp(msg, sk, skb); 2236 else 2237 sk->sk_stamp = kt; 2238 2239 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2240 __sock_recv_wifi_status(msg, sk, skb); 2241 } 2242 2243 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2244 struct sk_buff *skb); 2245 2246 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC) 2247 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2248 struct sk_buff *skb) 2249 { 2250 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2251 (1UL << SOCK_RCVTSTAMP)) 2252 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2253 SOF_TIMESTAMPING_RAW_HARDWARE) 2254 2255 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2256 __sock_recv_ts_and_drops(msg, sk, skb); 2257 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) 2258 sk->sk_stamp = skb->tstamp; 2259 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) 2260 sk->sk_stamp = 0; 2261 } 2262 2263 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); 2264 2265 /** 2266 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2267 * @sk: socket sending this packet 2268 * @tsflags: timestamping flags to use 2269 * @tx_flags: completed with instructions for time stamping 2270 * 2271 * Note: callers should take care of initial ``*tx_flags`` value (usually 0) 2272 */ 2273 static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags, 2274 __u8 *tx_flags) 2275 { 2276 if (unlikely(tsflags)) 2277 __sock_tx_timestamp(tsflags, tx_flags); 2278 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2279 *tx_flags |= SKBTX_WIFI_STATUS; 2280 } 2281 2282 /** 2283 * sk_eat_skb - Release a skb if it is no longer needed 2284 * @sk: socket to eat this skb from 2285 * @skb: socket buffer to eat 2286 * 2287 * This routine must be called with interrupts disabled or with the socket 2288 * locked so that the sk_buff queue operation is ok. 2289 */ 2290 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2291 { 2292 __skb_unlink(skb, &sk->sk_receive_queue); 2293 __kfree_skb(skb); 2294 } 2295 2296 static inline 2297 struct net *sock_net(const struct sock *sk) 2298 { 2299 return read_pnet(&sk->sk_net); 2300 } 2301 2302 static inline 2303 void sock_net_set(struct sock *sk, struct net *net) 2304 { 2305 write_pnet(&sk->sk_net, net); 2306 } 2307 2308 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2309 { 2310 if (skb->sk) { 2311 struct sock *sk = skb->sk; 2312 2313 skb->destructor = NULL; 2314 skb->sk = NULL; 2315 return sk; 2316 } 2317 return NULL; 2318 } 2319 2320 /* This helper checks if a socket is a full socket, 2321 * ie _not_ a timewait or request socket. 2322 */ 2323 static inline bool sk_fullsock(const struct sock *sk) 2324 { 2325 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2326 } 2327 2328 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2329 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2330 */ 2331 static inline bool sk_listener(const struct sock *sk) 2332 { 2333 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2334 } 2335 2336 /** 2337 * sk_state_load - read sk->sk_state for lockless contexts 2338 * @sk: socket pointer 2339 * 2340 * Paired with sk_state_store(). Used in places we do not hold socket lock : 2341 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... 2342 */ 2343 static inline int sk_state_load(const struct sock *sk) 2344 { 2345 return smp_load_acquire(&sk->sk_state); 2346 } 2347 2348 /** 2349 * sk_state_store - update sk->sk_state 2350 * @sk: socket pointer 2351 * @newstate: new state 2352 * 2353 * Paired with sk_state_load(). Should be used in contexts where 2354 * state change might impact lockless readers. 2355 */ 2356 static inline void sk_state_store(struct sock *sk, int newstate) 2357 { 2358 smp_store_release(&sk->sk_state, newstate); 2359 } 2360 2361 void sock_enable_timestamp(struct sock *sk, int flag); 2362 int sock_get_timestamp(struct sock *, struct timeval __user *); 2363 int sock_get_timestampns(struct sock *, struct timespec __user *); 2364 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2365 int type); 2366 2367 bool sk_ns_capable(const struct sock *sk, 2368 struct user_namespace *user_ns, int cap); 2369 bool sk_capable(const struct sock *sk, int cap); 2370 bool sk_net_capable(const struct sock *sk, int cap); 2371 2372 void sk_get_meminfo(const struct sock *sk, u32 *meminfo); 2373 2374 /* Take into consideration the size of the struct sk_buff overhead in the 2375 * determination of these values, since that is non-constant across 2376 * platforms. This makes socket queueing behavior and performance 2377 * not depend upon such differences. 2378 */ 2379 #define _SK_MEM_PACKETS 256 2380 #define _SK_MEM_OVERHEAD SKB_TRUESIZE(256) 2381 #define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2382 #define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2383 2384 extern __u32 sysctl_wmem_max; 2385 extern __u32 sysctl_rmem_max; 2386 2387 extern int sysctl_tstamp_allow_data; 2388 extern int sysctl_optmem_max; 2389 2390 extern __u32 sysctl_wmem_default; 2391 extern __u32 sysctl_rmem_default; 2392 2393 #endif /* _SOCK_H */ 2394