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 #include <net/l3mdev.h> 76 77 /* 78 * This structure really needs to be cleaned up. 79 * Most of it is for TCP, and not used by any of 80 * the other protocols. 81 */ 82 83 /* Define this to get the SOCK_DBG debugging facility. */ 84 #define SOCK_DEBUGGING 85 #ifdef SOCK_DEBUGGING 86 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 87 printk(KERN_DEBUG msg); } while (0) 88 #else 89 /* Validate arguments and do nothing */ 90 static inline __printf(2, 3) 91 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 92 { 93 } 94 #endif 95 96 /* This is the per-socket lock. The spinlock provides a synchronization 97 * between user contexts and software interrupt processing, whereas the 98 * mini-semaphore synchronizes multiple users amongst themselves. 99 */ 100 typedef struct { 101 spinlock_t slock; 102 int owned; 103 wait_queue_head_t wq; 104 /* 105 * We express the mutex-alike socket_lock semantics 106 * to the lock validator by explicitly managing 107 * the slock as a lock variant (in addition to 108 * the slock itself): 109 */ 110 #ifdef CONFIG_DEBUG_LOCK_ALLOC 111 struct lockdep_map dep_map; 112 #endif 113 } socket_lock_t; 114 115 struct sock; 116 struct proto; 117 struct net; 118 119 typedef __u32 __bitwise __portpair; 120 typedef __u64 __bitwise __addrpair; 121 122 /** 123 * struct sock_common - minimal network layer representation of sockets 124 * @skc_daddr: Foreign IPv4 addr 125 * @skc_rcv_saddr: Bound local IPv4 addr 126 * @skc_hash: hash value used with various protocol lookup tables 127 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 128 * @skc_dport: placeholder for inet_dport/tw_dport 129 * @skc_num: placeholder for inet_num/tw_num 130 * @skc_family: network address family 131 * @skc_state: Connection state 132 * @skc_reuse: %SO_REUSEADDR setting 133 * @skc_reuseport: %SO_REUSEPORT setting 134 * @skc_bound_dev_if: bound device index if != 0 135 * @skc_bind_node: bind hash linkage for various protocol lookup tables 136 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol 137 * @skc_prot: protocol handlers inside a network family 138 * @skc_net: reference to the network namespace of this socket 139 * @skc_node: main hash linkage for various protocol lookup tables 140 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 141 * @skc_tx_queue_mapping: tx queue number for this connection 142 * @skc_flags: place holder for sk_flags 143 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 144 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 145 * @skc_incoming_cpu: record/match cpu processing incoming packets 146 * @skc_refcnt: reference count 147 * 148 * This is the minimal network layer representation of sockets, the header 149 * for struct sock and struct inet_timewait_sock. 150 */ 151 struct sock_common { 152 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 153 * address on 64bit arches : cf INET_MATCH() 154 */ 155 union { 156 __addrpair skc_addrpair; 157 struct { 158 __be32 skc_daddr; 159 __be32 skc_rcv_saddr; 160 }; 161 }; 162 union { 163 unsigned int skc_hash; 164 __u16 skc_u16hashes[2]; 165 }; 166 /* skc_dport && skc_num must be grouped as well */ 167 union { 168 __portpair skc_portpair; 169 struct { 170 __be16 skc_dport; 171 __u16 skc_num; 172 }; 173 }; 174 175 unsigned short skc_family; 176 volatile unsigned char skc_state; 177 unsigned char skc_reuse:4; 178 unsigned char skc_reuseport:1; 179 unsigned char skc_ipv6only:1; 180 unsigned char skc_net_refcnt:1; 181 int skc_bound_dev_if; 182 union { 183 struct hlist_node skc_bind_node; 184 struct hlist_node skc_portaddr_node; 185 }; 186 struct proto *skc_prot; 187 possible_net_t skc_net; 188 189 #if IS_ENABLED(CONFIG_IPV6) 190 struct in6_addr skc_v6_daddr; 191 struct in6_addr skc_v6_rcv_saddr; 192 #endif 193 194 atomic64_t skc_cookie; 195 196 /* following fields are padding to force 197 * offset(struct sock, sk_refcnt) == 128 on 64bit arches 198 * assuming IPV6 is enabled. We use this padding differently 199 * for different kind of 'sockets' 200 */ 201 union { 202 unsigned long skc_flags; 203 struct sock *skc_listener; /* request_sock */ 204 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */ 205 }; 206 /* 207 * fields between dontcopy_begin/dontcopy_end 208 * are not copied in sock_copy() 209 */ 210 /* private: */ 211 int skc_dontcopy_begin[0]; 212 /* public: */ 213 union { 214 struct hlist_node skc_node; 215 struct hlist_nulls_node skc_nulls_node; 216 }; 217 int skc_tx_queue_mapping; 218 union { 219 int skc_incoming_cpu; 220 u32 skc_rcv_wnd; 221 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */ 222 }; 223 224 refcount_t skc_refcnt; 225 /* private: */ 226 int skc_dontcopy_end[0]; 227 union { 228 u32 skc_rxhash; 229 u32 skc_window_clamp; 230 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ 231 }; 232 /* public: */ 233 }; 234 235 /** 236 * struct sock - network layer representation of sockets 237 * @__sk_common: shared layout with inet_timewait_sock 238 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 239 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 240 * @sk_lock: synchronizer 241 * @sk_kern_sock: True if sock is using kernel lock classes 242 * @sk_rcvbuf: size of receive buffer in bytes 243 * @sk_wq: sock wait queue and async head 244 * @sk_rx_dst: receive input route used by early demux 245 * @sk_dst_cache: destination cache 246 * @sk_dst_pending_confirm: need to confirm neighbour 247 * @sk_policy: flow policy 248 * @sk_receive_queue: incoming packets 249 * @sk_wmem_alloc: transmit queue bytes committed 250 * @sk_tsq_flags: TCP Small Queues flags 251 * @sk_write_queue: Packet sending queue 252 * @sk_omem_alloc: "o" is "option" or "other" 253 * @sk_wmem_queued: persistent queue size 254 * @sk_forward_alloc: space allocated forward 255 * @sk_napi_id: id of the last napi context to receive data for sk 256 * @sk_ll_usec: usecs to busypoll when there is no data 257 * @sk_allocation: allocation mode 258 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler) 259 * @sk_pacing_status: Pacing status (requested, handled by sch_fq) 260 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE) 261 * @sk_sndbuf: size of send buffer in bytes 262 * @__sk_flags_offset: empty field used to determine location of bitfield 263 * @sk_padding: unused element for alignment 264 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets 265 * @sk_no_check_rx: allow zero checksum in RX packets 266 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 267 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK) 268 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 269 * @sk_gso_max_size: Maximum GSO segment size to build 270 * @sk_gso_max_segs: Maximum number of GSO segments 271 * @sk_pacing_shift: scaling factor for TCP Small Queues 272 * @sk_lingertime: %SO_LINGER l_linger setting 273 * @sk_backlog: always used with the per-socket spinlock held 274 * @sk_callback_lock: used with the callbacks in the end of this struct 275 * @sk_error_queue: rarely used 276 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 277 * IPV6_ADDRFORM for instance) 278 * @sk_err: last error 279 * @sk_err_soft: errors that don't cause failure but are the cause of a 280 * persistent failure not just 'timed out' 281 * @sk_drops: raw/udp drops counter 282 * @sk_ack_backlog: current listen backlog 283 * @sk_max_ack_backlog: listen backlog set in listen() 284 * @sk_uid: user id of owner 285 * @sk_priority: %SO_PRIORITY setting 286 * @sk_type: socket type (%SOCK_STREAM, etc) 287 * @sk_protocol: which protocol this socket belongs in this network family 288 * @sk_peer_pid: &struct pid for this socket's peer 289 * @sk_peer_cred: %SO_PEERCRED setting 290 * @sk_rcvlowat: %SO_RCVLOWAT setting 291 * @sk_rcvtimeo: %SO_RCVTIMEO setting 292 * @sk_sndtimeo: %SO_SNDTIMEO setting 293 * @sk_txhash: computed flow hash for use on transmit 294 * @sk_filter: socket filtering instructions 295 * @sk_timer: sock cleanup timer 296 * @sk_stamp: time stamp of last packet received 297 * @sk_tsflags: SO_TIMESTAMPING socket options 298 * @sk_tskey: counter to disambiguate concurrent tstamp requests 299 * @sk_zckey: counter to order MSG_ZEROCOPY notifications 300 * @sk_socket: Identd and reporting IO signals 301 * @sk_user_data: RPC layer private data 302 * @sk_frag: cached page frag 303 * @sk_peek_off: current peek_offset value 304 * @sk_send_head: front of stuff to transmit 305 * @sk_security: used by security modules 306 * @sk_mark: generic packet mark 307 * @sk_cgrp_data: cgroup data for this cgroup 308 * @sk_memcg: this socket's memory cgroup association 309 * @sk_write_pending: a write to stream socket waits to start 310 * @sk_state_change: callback to indicate change in the state of the sock 311 * @sk_data_ready: callback to indicate there is data to be processed 312 * @sk_write_space: callback to indicate there is bf sending space available 313 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 314 * @sk_backlog_rcv: callback to process the backlog 315 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 316 * @sk_reuseport_cb: reuseport group container 317 * @sk_rcu: used during RCU grace period 318 */ 319 struct sock { 320 /* 321 * Now struct inet_timewait_sock also uses sock_common, so please just 322 * don't add nothing before this first member (__sk_common) --acme 323 */ 324 struct sock_common __sk_common; 325 #define sk_node __sk_common.skc_node 326 #define sk_nulls_node __sk_common.skc_nulls_node 327 #define sk_refcnt __sk_common.skc_refcnt 328 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 329 330 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 331 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 332 #define sk_hash __sk_common.skc_hash 333 #define sk_portpair __sk_common.skc_portpair 334 #define sk_num __sk_common.skc_num 335 #define sk_dport __sk_common.skc_dport 336 #define sk_addrpair __sk_common.skc_addrpair 337 #define sk_daddr __sk_common.skc_daddr 338 #define sk_rcv_saddr __sk_common.skc_rcv_saddr 339 #define sk_family __sk_common.skc_family 340 #define sk_state __sk_common.skc_state 341 #define sk_reuse __sk_common.skc_reuse 342 #define sk_reuseport __sk_common.skc_reuseport 343 #define sk_ipv6only __sk_common.skc_ipv6only 344 #define sk_net_refcnt __sk_common.skc_net_refcnt 345 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 346 #define sk_bind_node __sk_common.skc_bind_node 347 #define sk_prot __sk_common.skc_prot 348 #define sk_net __sk_common.skc_net 349 #define sk_v6_daddr __sk_common.skc_v6_daddr 350 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr 351 #define sk_cookie __sk_common.skc_cookie 352 #define sk_incoming_cpu __sk_common.skc_incoming_cpu 353 #define sk_flags __sk_common.skc_flags 354 #define sk_rxhash __sk_common.skc_rxhash 355 356 socket_lock_t sk_lock; 357 atomic_t sk_drops; 358 int sk_rcvlowat; 359 struct sk_buff_head sk_error_queue; 360 struct sk_buff_head sk_receive_queue; 361 /* 362 * The backlog queue is special, it is always used with 363 * the per-socket spinlock held and requires low latency 364 * access. Therefore we special case it's implementation. 365 * Note : rmem_alloc is in this structure to fill a hole 366 * on 64bit arches, not because its logically part of 367 * backlog. 368 */ 369 struct { 370 atomic_t rmem_alloc; 371 int len; 372 struct sk_buff *head; 373 struct sk_buff *tail; 374 } sk_backlog; 375 #define sk_rmem_alloc sk_backlog.rmem_alloc 376 377 int sk_forward_alloc; 378 #ifdef CONFIG_NET_RX_BUSY_POLL 379 unsigned int sk_ll_usec; 380 /* ===== mostly read cache line ===== */ 381 unsigned int sk_napi_id; 382 #endif 383 int sk_rcvbuf; 384 385 struct sk_filter __rcu *sk_filter; 386 union { 387 struct socket_wq __rcu *sk_wq; 388 struct socket_wq *sk_wq_raw; 389 }; 390 #ifdef CONFIG_XFRM 391 struct xfrm_policy __rcu *sk_policy[2]; 392 #endif 393 struct dst_entry *sk_rx_dst; 394 struct dst_entry __rcu *sk_dst_cache; 395 atomic_t sk_omem_alloc; 396 int sk_sndbuf; 397 398 /* ===== cache line for TX ===== */ 399 int sk_wmem_queued; 400 refcount_t sk_wmem_alloc; 401 unsigned long sk_tsq_flags; 402 union { 403 struct sk_buff *sk_send_head; 404 struct rb_root tcp_rtx_queue; 405 }; 406 struct sk_buff_head sk_write_queue; 407 __s32 sk_peek_off; 408 int sk_write_pending; 409 __u32 sk_dst_pending_confirm; 410 u32 sk_pacing_status; /* see enum sk_pacing */ 411 long sk_sndtimeo; 412 struct timer_list sk_timer; 413 __u32 sk_priority; 414 __u32 sk_mark; 415 u32 sk_pacing_rate; /* bytes per second */ 416 u32 sk_max_pacing_rate; 417 struct page_frag sk_frag; 418 netdev_features_t sk_route_caps; 419 netdev_features_t sk_route_nocaps; 420 int sk_gso_type; 421 unsigned int sk_gso_max_size; 422 gfp_t sk_allocation; 423 __u32 sk_txhash; 424 425 /* 426 * Because of non atomicity rules, all 427 * changes are protected by socket lock. 428 */ 429 unsigned int __sk_flags_offset[0]; 430 #ifdef __BIG_ENDIAN_BITFIELD 431 #define SK_FL_PROTO_SHIFT 16 432 #define SK_FL_PROTO_MASK 0x00ff0000 433 434 #define SK_FL_TYPE_SHIFT 0 435 #define SK_FL_TYPE_MASK 0x0000ffff 436 #else 437 #define SK_FL_PROTO_SHIFT 8 438 #define SK_FL_PROTO_MASK 0x0000ff00 439 440 #define SK_FL_TYPE_SHIFT 16 441 #define SK_FL_TYPE_MASK 0xffff0000 442 #endif 443 444 unsigned int sk_padding : 1, 445 sk_kern_sock : 1, 446 sk_no_check_tx : 1, 447 sk_no_check_rx : 1, 448 sk_userlocks : 4, 449 sk_protocol : 8, 450 sk_type : 16; 451 #define SK_PROTOCOL_MAX U8_MAX 452 u16 sk_gso_max_segs; 453 u8 sk_pacing_shift; 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 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 690 } 691 692 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 693 { 694 sock_hold(sk); 695 __sk_nulls_add_node_rcu(sk, list); 696 } 697 698 static inline void __sk_del_bind_node(struct sock *sk) 699 { 700 __hlist_del(&sk->sk_bind_node); 701 } 702 703 static inline void sk_add_bind_node(struct sock *sk, 704 struct hlist_head *list) 705 { 706 hlist_add_head(&sk->sk_bind_node, list); 707 } 708 709 #define sk_for_each(__sk, list) \ 710 hlist_for_each_entry(__sk, list, sk_node) 711 #define sk_for_each_rcu(__sk, list) \ 712 hlist_for_each_entry_rcu(__sk, list, sk_node) 713 #define sk_nulls_for_each(__sk, node, list) \ 714 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 715 #define sk_nulls_for_each_rcu(__sk, node, list) \ 716 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 717 #define sk_for_each_from(__sk) \ 718 hlist_for_each_entry_from(__sk, sk_node) 719 #define sk_nulls_for_each_from(__sk, node) \ 720 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 721 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 722 #define sk_for_each_safe(__sk, tmp, list) \ 723 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 724 #define sk_for_each_bound(__sk, list) \ 725 hlist_for_each_entry(__sk, list, sk_bind_node) 726 727 /** 728 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset 729 * @tpos: the type * to use as a loop cursor. 730 * @pos: the &struct hlist_node to use as a loop cursor. 731 * @head: the head for your list. 732 * @offset: offset of hlist_node within the struct. 733 * 734 */ 735 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \ 736 for (pos = rcu_dereference(hlist_first_rcu(head)); \ 737 pos != NULL && \ 738 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 739 pos = rcu_dereference(hlist_next_rcu(pos))) 740 741 static inline struct user_namespace *sk_user_ns(struct sock *sk) 742 { 743 /* Careful only use this in a context where these parameters 744 * can not change and must all be valid, such as recvmsg from 745 * userspace. 746 */ 747 return sk->sk_socket->file->f_cred->user_ns; 748 } 749 750 /* Sock flags */ 751 enum sock_flags { 752 SOCK_DEAD, 753 SOCK_DONE, 754 SOCK_URGINLINE, 755 SOCK_KEEPOPEN, 756 SOCK_LINGER, 757 SOCK_DESTROY, 758 SOCK_BROADCAST, 759 SOCK_TIMESTAMP, 760 SOCK_ZAPPED, 761 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 762 SOCK_DBG, /* %SO_DEBUG setting */ 763 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 764 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 765 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 766 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ 767 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 768 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 769 SOCK_FASYNC, /* fasync() active */ 770 SOCK_RXQ_OVFL, 771 SOCK_ZEROCOPY, /* buffers from userspace */ 772 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 773 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 774 * Will use last 4 bytes of packet sent from 775 * user-space instead. 776 */ 777 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 778 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 779 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */ 780 }; 781 782 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) 783 784 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 785 { 786 nsk->sk_flags = osk->sk_flags; 787 } 788 789 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 790 { 791 __set_bit(flag, &sk->sk_flags); 792 } 793 794 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 795 { 796 __clear_bit(flag, &sk->sk_flags); 797 } 798 799 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 800 { 801 return test_bit(flag, &sk->sk_flags); 802 } 803 804 #ifdef CONFIG_NET 805 extern struct static_key memalloc_socks; 806 static inline int sk_memalloc_socks(void) 807 { 808 return static_key_false(&memalloc_socks); 809 } 810 #else 811 812 static inline int sk_memalloc_socks(void) 813 { 814 return 0; 815 } 816 817 #endif 818 819 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 820 { 821 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC); 822 } 823 824 static inline void sk_acceptq_removed(struct sock *sk) 825 { 826 sk->sk_ack_backlog--; 827 } 828 829 static inline void sk_acceptq_added(struct sock *sk) 830 { 831 sk->sk_ack_backlog++; 832 } 833 834 static inline bool sk_acceptq_is_full(const struct sock *sk) 835 { 836 return sk->sk_ack_backlog > sk->sk_max_ack_backlog; 837 } 838 839 /* 840 * Compute minimal free write space needed to queue new packets. 841 */ 842 static inline int sk_stream_min_wspace(const struct sock *sk) 843 { 844 return sk->sk_wmem_queued >> 1; 845 } 846 847 static inline int sk_stream_wspace(const struct sock *sk) 848 { 849 return sk->sk_sndbuf - sk->sk_wmem_queued; 850 } 851 852 void sk_stream_write_space(struct sock *sk); 853 854 /* OOB backlog add */ 855 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 856 { 857 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 858 skb_dst_force(skb); 859 860 if (!sk->sk_backlog.tail) 861 sk->sk_backlog.head = skb; 862 else 863 sk->sk_backlog.tail->next = skb; 864 865 sk->sk_backlog.tail = skb; 866 skb->next = NULL; 867 } 868 869 /* 870 * Take into account size of receive queue and backlog queue 871 * Do not take into account this skb truesize, 872 * to allow even a single big packet to come. 873 */ 874 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 875 { 876 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 877 878 return qsize > limit; 879 } 880 881 /* The per-socket spinlock must be held here. */ 882 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 883 unsigned int limit) 884 { 885 if (sk_rcvqueues_full(sk, limit)) 886 return -ENOBUFS; 887 888 /* 889 * If the skb was allocated from pfmemalloc reserves, only 890 * allow SOCK_MEMALLOC sockets to use it as this socket is 891 * helping free memory 892 */ 893 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 894 return -ENOMEM; 895 896 __sk_add_backlog(sk, skb); 897 sk->sk_backlog.len += skb->truesize; 898 return 0; 899 } 900 901 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 902 903 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 904 { 905 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 906 return __sk_backlog_rcv(sk, skb); 907 908 return sk->sk_backlog_rcv(sk, skb); 909 } 910 911 static inline void sk_incoming_cpu_update(struct sock *sk) 912 { 913 int cpu = raw_smp_processor_id(); 914 915 if (unlikely(sk->sk_incoming_cpu != cpu)) 916 sk->sk_incoming_cpu = cpu; 917 } 918 919 static inline void sock_rps_record_flow_hash(__u32 hash) 920 { 921 #ifdef CONFIG_RPS 922 struct rps_sock_flow_table *sock_flow_table; 923 924 rcu_read_lock(); 925 sock_flow_table = rcu_dereference(rps_sock_flow_table); 926 rps_record_sock_flow(sock_flow_table, hash); 927 rcu_read_unlock(); 928 #endif 929 } 930 931 static inline void sock_rps_record_flow(const struct sock *sk) 932 { 933 #ifdef CONFIG_RPS 934 if (static_key_false(&rfs_needed)) { 935 /* Reading sk->sk_rxhash might incur an expensive cache line 936 * miss. 937 * 938 * TCP_ESTABLISHED does cover almost all states where RFS 939 * might be useful, and is cheaper [1] than testing : 940 * IPv4: inet_sk(sk)->inet_daddr 941 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr) 942 * OR an additional socket flag 943 * [1] : sk_state and sk_prot are in the same cache line. 944 */ 945 if (sk->sk_state == TCP_ESTABLISHED) 946 sock_rps_record_flow_hash(sk->sk_rxhash); 947 } 948 #endif 949 } 950 951 static inline void sock_rps_save_rxhash(struct sock *sk, 952 const struct sk_buff *skb) 953 { 954 #ifdef CONFIG_RPS 955 if (unlikely(sk->sk_rxhash != skb->hash)) 956 sk->sk_rxhash = skb->hash; 957 #endif 958 } 959 960 static inline void sock_rps_reset_rxhash(struct sock *sk) 961 { 962 #ifdef CONFIG_RPS 963 sk->sk_rxhash = 0; 964 #endif 965 } 966 967 #define sk_wait_event(__sk, __timeo, __condition, __wait) \ 968 ({ int __rc; \ 969 release_sock(__sk); \ 970 __rc = __condition; \ 971 if (!__rc) { \ 972 *(__timeo) = wait_woken(__wait, \ 973 TASK_INTERRUPTIBLE, \ 974 *(__timeo)); \ 975 } \ 976 sched_annotate_sleep(); \ 977 lock_sock(__sk); \ 978 __rc = __condition; \ 979 __rc; \ 980 }) 981 982 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 983 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 984 void sk_stream_wait_close(struct sock *sk, long timeo_p); 985 int sk_stream_error(struct sock *sk, int flags, int err); 986 void sk_stream_kill_queues(struct sock *sk); 987 void sk_set_memalloc(struct sock *sk); 988 void sk_clear_memalloc(struct sock *sk); 989 990 void __sk_flush_backlog(struct sock *sk); 991 992 static inline bool sk_flush_backlog(struct sock *sk) 993 { 994 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) { 995 __sk_flush_backlog(sk); 996 return true; 997 } 998 return false; 999 } 1000 1001 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 1002 1003 struct request_sock_ops; 1004 struct timewait_sock_ops; 1005 struct inet_hashinfo; 1006 struct raw_hashinfo; 1007 struct smc_hashinfo; 1008 struct module; 1009 1010 /* 1011 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes 1012 * un-modified. Special care is taken when initializing object to zero. 1013 */ 1014 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 1015 { 1016 if (offsetof(struct sock, sk_node.next) != 0) 1017 memset(sk, 0, offsetof(struct sock, sk_node.next)); 1018 memset(&sk->sk_node.pprev, 0, 1019 size - offsetof(struct sock, sk_node.pprev)); 1020 } 1021 1022 /* Networking protocol blocks we attach to sockets. 1023 * socket layer -> transport layer interface 1024 */ 1025 struct proto { 1026 void (*close)(struct sock *sk, 1027 long timeout); 1028 int (*connect)(struct sock *sk, 1029 struct sockaddr *uaddr, 1030 int addr_len); 1031 int (*disconnect)(struct sock *sk, int flags); 1032 1033 struct sock * (*accept)(struct sock *sk, int flags, int *err, 1034 bool kern); 1035 1036 int (*ioctl)(struct sock *sk, int cmd, 1037 unsigned long arg); 1038 int (*init)(struct sock *sk); 1039 void (*destroy)(struct sock *sk); 1040 void (*shutdown)(struct sock *sk, int how); 1041 int (*setsockopt)(struct sock *sk, int level, 1042 int optname, char __user *optval, 1043 unsigned int optlen); 1044 int (*getsockopt)(struct sock *sk, int level, 1045 int optname, char __user *optval, 1046 int __user *option); 1047 void (*keepalive)(struct sock *sk, int valbool); 1048 #ifdef CONFIG_COMPAT 1049 int (*compat_setsockopt)(struct sock *sk, 1050 int level, 1051 int optname, char __user *optval, 1052 unsigned int optlen); 1053 int (*compat_getsockopt)(struct sock *sk, 1054 int level, 1055 int optname, char __user *optval, 1056 int __user *option); 1057 int (*compat_ioctl)(struct sock *sk, 1058 unsigned int cmd, unsigned long arg); 1059 #endif 1060 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 1061 size_t len); 1062 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 1063 size_t len, int noblock, int flags, 1064 int *addr_len); 1065 int (*sendpage)(struct sock *sk, struct page *page, 1066 int offset, size_t size, int flags); 1067 int (*bind)(struct sock *sk, 1068 struct sockaddr *uaddr, int addr_len); 1069 1070 int (*backlog_rcv) (struct sock *sk, 1071 struct sk_buff *skb); 1072 1073 void (*release_cb)(struct sock *sk); 1074 1075 /* Keeping track of sk's, looking them up, and port selection methods. */ 1076 int (*hash)(struct sock *sk); 1077 void (*unhash)(struct sock *sk); 1078 void (*rehash)(struct sock *sk); 1079 int (*get_port)(struct sock *sk, unsigned short snum); 1080 1081 /* Keeping track of sockets in use */ 1082 #ifdef CONFIG_PROC_FS 1083 unsigned int inuse_idx; 1084 #endif 1085 1086 bool (*stream_memory_free)(const struct sock *sk); 1087 /* Memory pressure */ 1088 void (*enter_memory_pressure)(struct sock *sk); 1089 void (*leave_memory_pressure)(struct sock *sk); 1090 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1091 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1092 /* 1093 * Pressure flag: try to collapse. 1094 * Technical note: it is used by multiple contexts non atomically. 1095 * All the __sk_mem_schedule() is of this nature: accounting 1096 * is strict, actions are advisory and have some latency. 1097 */ 1098 unsigned long *memory_pressure; 1099 long *sysctl_mem; 1100 1101 int *sysctl_wmem; 1102 int *sysctl_rmem; 1103 u32 sysctl_wmem_offset; 1104 u32 sysctl_rmem_offset; 1105 1106 int max_header; 1107 bool no_autobind; 1108 1109 struct kmem_cache *slab; 1110 unsigned int obj_size; 1111 slab_flags_t slab_flags; 1112 size_t useroffset; /* Usercopy region offset */ 1113 size_t usersize; /* Usercopy region size */ 1114 1115 struct percpu_counter *orphan_count; 1116 1117 struct request_sock_ops *rsk_prot; 1118 struct timewait_sock_ops *twsk_prot; 1119 1120 union { 1121 struct inet_hashinfo *hashinfo; 1122 struct udp_table *udp_table; 1123 struct raw_hashinfo *raw_hash; 1124 struct smc_hashinfo *smc_hash; 1125 } h; 1126 1127 struct module *owner; 1128 1129 char name[32]; 1130 1131 struct list_head node; 1132 #ifdef SOCK_REFCNT_DEBUG 1133 atomic_t socks; 1134 #endif 1135 int (*diag_destroy)(struct sock *sk, int err); 1136 } __randomize_layout; 1137 1138 int proto_register(struct proto *prot, int alloc_slab); 1139 void proto_unregister(struct proto *prot); 1140 int sock_load_diag_module(int family, int protocol); 1141 1142 #ifdef SOCK_REFCNT_DEBUG 1143 static inline void sk_refcnt_debug_inc(struct sock *sk) 1144 { 1145 atomic_inc(&sk->sk_prot->socks); 1146 } 1147 1148 static inline void sk_refcnt_debug_dec(struct sock *sk) 1149 { 1150 atomic_dec(&sk->sk_prot->socks); 1151 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1152 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1153 } 1154 1155 static inline void sk_refcnt_debug_release(const struct sock *sk) 1156 { 1157 if (refcount_read(&sk->sk_refcnt) != 1) 1158 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1159 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt)); 1160 } 1161 #else /* SOCK_REFCNT_DEBUG */ 1162 #define sk_refcnt_debug_inc(sk) do { } while (0) 1163 #define sk_refcnt_debug_dec(sk) do { } while (0) 1164 #define sk_refcnt_debug_release(sk) do { } while (0) 1165 #endif /* SOCK_REFCNT_DEBUG */ 1166 1167 static inline bool sk_stream_memory_free(const struct sock *sk) 1168 { 1169 if (sk->sk_wmem_queued >= sk->sk_sndbuf) 1170 return false; 1171 1172 return sk->sk_prot->stream_memory_free ? 1173 sk->sk_prot->stream_memory_free(sk) : true; 1174 } 1175 1176 static inline bool sk_stream_is_writeable(const struct sock *sk) 1177 { 1178 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1179 sk_stream_memory_free(sk); 1180 } 1181 1182 static inline int sk_under_cgroup_hierarchy(struct sock *sk, 1183 struct cgroup *ancestor) 1184 { 1185 #ifdef CONFIG_SOCK_CGROUP_DATA 1186 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), 1187 ancestor); 1188 #else 1189 return -ENOTSUPP; 1190 #endif 1191 } 1192 1193 static inline bool sk_has_memory_pressure(const struct sock *sk) 1194 { 1195 return sk->sk_prot->memory_pressure != NULL; 1196 } 1197 1198 static inline bool sk_under_memory_pressure(const struct sock *sk) 1199 { 1200 if (!sk->sk_prot->memory_pressure) 1201 return false; 1202 1203 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 1204 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 1205 return true; 1206 1207 return !!*sk->sk_prot->memory_pressure; 1208 } 1209 1210 static inline long 1211 sk_memory_allocated(const struct sock *sk) 1212 { 1213 return atomic_long_read(sk->sk_prot->memory_allocated); 1214 } 1215 1216 static inline long 1217 sk_memory_allocated_add(struct sock *sk, int amt) 1218 { 1219 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated); 1220 } 1221 1222 static inline void 1223 sk_memory_allocated_sub(struct sock *sk, int amt) 1224 { 1225 atomic_long_sub(amt, sk->sk_prot->memory_allocated); 1226 } 1227 1228 static inline void sk_sockets_allocated_dec(struct sock *sk) 1229 { 1230 percpu_counter_dec(sk->sk_prot->sockets_allocated); 1231 } 1232 1233 static inline void sk_sockets_allocated_inc(struct sock *sk) 1234 { 1235 percpu_counter_inc(sk->sk_prot->sockets_allocated); 1236 } 1237 1238 static inline int 1239 sk_sockets_allocated_read_positive(struct sock *sk) 1240 { 1241 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated); 1242 } 1243 1244 static inline int 1245 proto_sockets_allocated_sum_positive(struct proto *prot) 1246 { 1247 return percpu_counter_sum_positive(prot->sockets_allocated); 1248 } 1249 1250 static inline long 1251 proto_memory_allocated(struct proto *prot) 1252 { 1253 return atomic_long_read(prot->memory_allocated); 1254 } 1255 1256 static inline bool 1257 proto_memory_pressure(struct proto *prot) 1258 { 1259 if (!prot->memory_pressure) 1260 return false; 1261 return !!*prot->memory_pressure; 1262 } 1263 1264 1265 #ifdef CONFIG_PROC_FS 1266 /* Called with local bh disabled */ 1267 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); 1268 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1269 int sock_inuse_get(struct net *net); 1270 #else 1271 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot, 1272 int inc) 1273 { 1274 } 1275 #endif 1276 1277 1278 /* With per-bucket locks this operation is not-atomic, so that 1279 * this version is not worse. 1280 */ 1281 static inline int __sk_prot_rehash(struct sock *sk) 1282 { 1283 sk->sk_prot->unhash(sk); 1284 return sk->sk_prot->hash(sk); 1285 } 1286 1287 /* About 10 seconds */ 1288 #define SOCK_DESTROY_TIME (10*HZ) 1289 1290 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1291 #define PROT_SOCK 1024 1292 1293 #define SHUTDOWN_MASK 3 1294 #define RCV_SHUTDOWN 1 1295 #define SEND_SHUTDOWN 2 1296 1297 #define SOCK_SNDBUF_LOCK 1 1298 #define SOCK_RCVBUF_LOCK 2 1299 #define SOCK_BINDADDR_LOCK 4 1300 #define SOCK_BINDPORT_LOCK 8 1301 1302 struct socket_alloc { 1303 struct socket socket; 1304 struct inode vfs_inode; 1305 }; 1306 1307 static inline struct socket *SOCKET_I(struct inode *inode) 1308 { 1309 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1310 } 1311 1312 static inline struct inode *SOCK_INODE(struct socket *socket) 1313 { 1314 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1315 } 1316 1317 /* 1318 * Functions for memory accounting 1319 */ 1320 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind); 1321 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1322 void __sk_mem_reduce_allocated(struct sock *sk, int amount); 1323 void __sk_mem_reclaim(struct sock *sk, int amount); 1324 1325 /* We used to have PAGE_SIZE here, but systems with 64KB pages 1326 * do not necessarily have 16x time more memory than 4KB ones. 1327 */ 1328 #define SK_MEM_QUANTUM 4096 1329 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1330 #define SK_MEM_SEND 0 1331 #define SK_MEM_RECV 1 1332 1333 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */ 1334 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1335 { 1336 long val = sk->sk_prot->sysctl_mem[index]; 1337 1338 #if PAGE_SIZE > SK_MEM_QUANTUM 1339 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT; 1340 #elif PAGE_SIZE < SK_MEM_QUANTUM 1341 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT; 1342 #endif 1343 return val; 1344 } 1345 1346 static inline int sk_mem_pages(int amt) 1347 { 1348 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1349 } 1350 1351 static inline bool sk_has_account(struct sock *sk) 1352 { 1353 /* return true if protocol supports memory accounting */ 1354 return !!sk->sk_prot->memory_allocated; 1355 } 1356 1357 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1358 { 1359 if (!sk_has_account(sk)) 1360 return true; 1361 return size <= sk->sk_forward_alloc || 1362 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1363 } 1364 1365 static inline bool 1366 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1367 { 1368 if (!sk_has_account(sk)) 1369 return true; 1370 return size<= sk->sk_forward_alloc || 1371 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1372 skb_pfmemalloc(skb); 1373 } 1374 1375 static inline void sk_mem_reclaim(struct sock *sk) 1376 { 1377 if (!sk_has_account(sk)) 1378 return; 1379 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM) 1380 __sk_mem_reclaim(sk, sk->sk_forward_alloc); 1381 } 1382 1383 static inline void sk_mem_reclaim_partial(struct sock *sk) 1384 { 1385 if (!sk_has_account(sk)) 1386 return; 1387 if (sk->sk_forward_alloc > SK_MEM_QUANTUM) 1388 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1); 1389 } 1390 1391 static inline void sk_mem_charge(struct sock *sk, int size) 1392 { 1393 if (!sk_has_account(sk)) 1394 return; 1395 sk->sk_forward_alloc -= size; 1396 } 1397 1398 static inline void sk_mem_uncharge(struct sock *sk, int size) 1399 { 1400 if (!sk_has_account(sk)) 1401 return; 1402 sk->sk_forward_alloc += size; 1403 1404 /* Avoid a possible overflow. 1405 * TCP send queues can make this happen, if sk_mem_reclaim() 1406 * is not called and more than 2 GBytes are released at once. 1407 * 1408 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is 1409 * no need to hold that much forward allocation anyway. 1410 */ 1411 if (unlikely(sk->sk_forward_alloc >= 1 << 21)) 1412 __sk_mem_reclaim(sk, 1 << 20); 1413 } 1414 1415 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 1416 { 1417 sock_set_flag(sk, SOCK_QUEUE_SHRUNK); 1418 sk->sk_wmem_queued -= skb->truesize; 1419 sk_mem_uncharge(sk, skb->truesize); 1420 __kfree_skb(skb); 1421 } 1422 1423 static inline void sock_release_ownership(struct sock *sk) 1424 { 1425 if (sk->sk_lock.owned) { 1426 sk->sk_lock.owned = 0; 1427 1428 /* The sk_lock has mutex_unlock() semantics: */ 1429 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_); 1430 } 1431 } 1432 1433 /* 1434 * Macro so as to not evaluate some arguments when 1435 * lockdep is not enabled. 1436 * 1437 * Mark both the sk_lock and the sk_lock.slock as a 1438 * per-address-family lock class. 1439 */ 1440 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1441 do { \ 1442 sk->sk_lock.owned = 0; \ 1443 init_waitqueue_head(&sk->sk_lock.wq); \ 1444 spin_lock_init(&(sk)->sk_lock.slock); \ 1445 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1446 sizeof((sk)->sk_lock)); \ 1447 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1448 (skey), (sname)); \ 1449 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1450 } while (0) 1451 1452 #ifdef CONFIG_LOCKDEP 1453 static inline bool lockdep_sock_is_held(const struct sock *sk) 1454 { 1455 return lockdep_is_held(&sk->sk_lock) || 1456 lockdep_is_held(&sk->sk_lock.slock); 1457 } 1458 #endif 1459 1460 void lock_sock_nested(struct sock *sk, int subclass); 1461 1462 static inline void lock_sock(struct sock *sk) 1463 { 1464 lock_sock_nested(sk, 0); 1465 } 1466 1467 void release_sock(struct sock *sk); 1468 1469 /* BH context may only use the following locking interface. */ 1470 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1471 #define bh_lock_sock_nested(__sk) \ 1472 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1473 SINGLE_DEPTH_NESTING) 1474 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1475 1476 bool lock_sock_fast(struct sock *sk); 1477 /** 1478 * unlock_sock_fast - complement of lock_sock_fast 1479 * @sk: socket 1480 * @slow: slow mode 1481 * 1482 * fast unlock socket for user context. 1483 * If slow mode is on, we call regular release_sock() 1484 */ 1485 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1486 { 1487 if (slow) 1488 release_sock(sk); 1489 else 1490 spin_unlock_bh(&sk->sk_lock.slock); 1491 } 1492 1493 /* Used by processes to "lock" a socket state, so that 1494 * interrupts and bottom half handlers won't change it 1495 * from under us. It essentially blocks any incoming 1496 * packets, so that we won't get any new data or any 1497 * packets that change the state of the socket. 1498 * 1499 * While locked, BH processing will add new packets to 1500 * the backlog queue. This queue is processed by the 1501 * owner of the socket lock right before it is released. 1502 * 1503 * Since ~2.3.5 it is also exclusive sleep lock serializing 1504 * accesses from user process context. 1505 */ 1506 1507 static inline void sock_owned_by_me(const struct sock *sk) 1508 { 1509 #ifdef CONFIG_LOCKDEP 1510 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks); 1511 #endif 1512 } 1513 1514 static inline bool sock_owned_by_user(const struct sock *sk) 1515 { 1516 sock_owned_by_me(sk); 1517 return sk->sk_lock.owned; 1518 } 1519 1520 static inline bool sock_owned_by_user_nocheck(const struct sock *sk) 1521 { 1522 return sk->sk_lock.owned; 1523 } 1524 1525 /* no reclassification while locks are held */ 1526 static inline bool sock_allow_reclassification(const struct sock *csk) 1527 { 1528 struct sock *sk = (struct sock *)csk; 1529 1530 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock); 1531 } 1532 1533 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1534 struct proto *prot, int kern); 1535 void sk_free(struct sock *sk); 1536 void sk_destruct(struct sock *sk); 1537 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1538 void sk_free_unlock_clone(struct sock *sk); 1539 1540 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1541 gfp_t priority); 1542 void __sock_wfree(struct sk_buff *skb); 1543 void sock_wfree(struct sk_buff *skb); 1544 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size, 1545 gfp_t priority); 1546 void skb_orphan_partial(struct sk_buff *skb); 1547 void sock_rfree(struct sk_buff *skb); 1548 void sock_efree(struct sk_buff *skb); 1549 #ifdef CONFIG_INET 1550 void sock_edemux(struct sk_buff *skb); 1551 #else 1552 #define sock_edemux sock_efree 1553 #endif 1554 1555 int sock_setsockopt(struct socket *sock, int level, int op, 1556 char __user *optval, unsigned int optlen); 1557 1558 int sock_getsockopt(struct socket *sock, int level, int op, 1559 char __user *optval, int __user *optlen); 1560 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1561 int noblock, int *errcode); 1562 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1563 unsigned long data_len, int noblock, 1564 int *errcode, int max_page_order); 1565 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1566 void sock_kfree_s(struct sock *sk, void *mem, int size); 1567 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1568 void sk_send_sigurg(struct sock *sk); 1569 1570 struct sockcm_cookie { 1571 u32 mark; 1572 u16 tsflags; 1573 }; 1574 1575 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg, 1576 struct sockcm_cookie *sockc); 1577 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1578 struct sockcm_cookie *sockc); 1579 1580 /* 1581 * Functions to fill in entries in struct proto_ops when a protocol 1582 * does not implement a particular function. 1583 */ 1584 int sock_no_bind(struct socket *, struct sockaddr *, int); 1585 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1586 int sock_no_socketpair(struct socket *, struct socket *); 1587 int sock_no_accept(struct socket *, struct socket *, int, bool); 1588 int sock_no_getname(struct socket *, struct sockaddr *, int *, int); 1589 __poll_t sock_no_poll(struct file *, struct socket *, 1590 struct poll_table_struct *); 1591 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1592 int sock_no_listen(struct socket *, int); 1593 int sock_no_shutdown(struct socket *, int); 1594 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *); 1595 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int); 1596 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1597 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len); 1598 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1599 int sock_no_mmap(struct file *file, struct socket *sock, 1600 struct vm_area_struct *vma); 1601 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1602 size_t size, int flags); 1603 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page, 1604 int offset, size_t size, int flags); 1605 1606 /* 1607 * Functions to fill in entries in struct proto_ops when a protocol 1608 * uses the inet style. 1609 */ 1610 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1611 char __user *optval, int __user *optlen); 1612 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1613 int flags); 1614 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1615 char __user *optval, unsigned int optlen); 1616 int compat_sock_common_getsockopt(struct socket *sock, int level, 1617 int optname, char __user *optval, int __user *optlen); 1618 int compat_sock_common_setsockopt(struct socket *sock, int level, 1619 int optname, char __user *optval, unsigned int optlen); 1620 1621 void sk_common_release(struct sock *sk); 1622 1623 /* 1624 * Default socket callbacks and setup code 1625 */ 1626 1627 /* Initialise core socket variables */ 1628 void sock_init_data(struct socket *sock, struct sock *sk); 1629 1630 /* 1631 * Socket reference counting postulates. 1632 * 1633 * * Each user of socket SHOULD hold a reference count. 1634 * * Each access point to socket (an hash table bucket, reference from a list, 1635 * running timer, skb in flight MUST hold a reference count. 1636 * * When reference count hits 0, it means it will never increase back. 1637 * * When reference count hits 0, it means that no references from 1638 * outside exist to this socket and current process on current CPU 1639 * is last user and may/should destroy this socket. 1640 * * sk_free is called from any context: process, BH, IRQ. When 1641 * it is called, socket has no references from outside -> sk_free 1642 * may release descendant resources allocated by the socket, but 1643 * to the time when it is called, socket is NOT referenced by any 1644 * hash tables, lists etc. 1645 * * Packets, delivered from outside (from network or from another process) 1646 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1647 * when they sit in queue. Otherwise, packets will leak to hole, when 1648 * socket is looked up by one cpu and unhasing is made by another CPU. 1649 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1650 * (leak to backlog). Packet socket does all the processing inside 1651 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1652 * use separate SMP lock, so that they are prone too. 1653 */ 1654 1655 /* Ungrab socket and destroy it, if it was the last reference. */ 1656 static inline void sock_put(struct sock *sk) 1657 { 1658 if (refcount_dec_and_test(&sk->sk_refcnt)) 1659 sk_free(sk); 1660 } 1661 /* Generic version of sock_put(), dealing with all sockets 1662 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1663 */ 1664 void sock_gen_put(struct sock *sk); 1665 1666 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested, 1667 unsigned int trim_cap, bool refcounted); 1668 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1669 const int nested) 1670 { 1671 return __sk_receive_skb(sk, skb, nested, 1, true); 1672 } 1673 1674 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1675 { 1676 sk->sk_tx_queue_mapping = tx_queue; 1677 } 1678 1679 static inline void sk_tx_queue_clear(struct sock *sk) 1680 { 1681 sk->sk_tx_queue_mapping = -1; 1682 } 1683 1684 static inline int sk_tx_queue_get(const struct sock *sk) 1685 { 1686 return sk ? sk->sk_tx_queue_mapping : -1; 1687 } 1688 1689 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 1690 { 1691 sk_tx_queue_clear(sk); 1692 sk->sk_socket = sock; 1693 } 1694 1695 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 1696 { 1697 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 1698 return &rcu_dereference_raw(sk->sk_wq)->wait; 1699 } 1700 /* Detach socket from process context. 1701 * Announce socket dead, detach it from wait queue and inode. 1702 * Note that parent inode held reference count on this struct sock, 1703 * we do not release it in this function, because protocol 1704 * probably wants some additional cleanups or even continuing 1705 * to work with this socket (TCP). 1706 */ 1707 static inline void sock_orphan(struct sock *sk) 1708 { 1709 write_lock_bh(&sk->sk_callback_lock); 1710 sock_set_flag(sk, SOCK_DEAD); 1711 sk_set_socket(sk, NULL); 1712 sk->sk_wq = NULL; 1713 write_unlock_bh(&sk->sk_callback_lock); 1714 } 1715 1716 static inline void sock_graft(struct sock *sk, struct socket *parent) 1717 { 1718 WARN_ON(parent->sk); 1719 write_lock_bh(&sk->sk_callback_lock); 1720 sk->sk_wq = parent->wq; 1721 parent->sk = sk; 1722 sk_set_socket(sk, parent); 1723 sk->sk_uid = SOCK_INODE(parent)->i_uid; 1724 security_sock_graft(sk, parent); 1725 write_unlock_bh(&sk->sk_callback_lock); 1726 } 1727 1728 kuid_t sock_i_uid(struct sock *sk); 1729 unsigned long sock_i_ino(struct sock *sk); 1730 1731 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk) 1732 { 1733 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0); 1734 } 1735 1736 static inline u32 net_tx_rndhash(void) 1737 { 1738 u32 v = prandom_u32(); 1739 1740 return v ?: 1; 1741 } 1742 1743 static inline void sk_set_txhash(struct sock *sk) 1744 { 1745 sk->sk_txhash = net_tx_rndhash(); 1746 } 1747 1748 static inline void sk_rethink_txhash(struct sock *sk) 1749 { 1750 if (sk->sk_txhash) 1751 sk_set_txhash(sk); 1752 } 1753 1754 static inline struct dst_entry * 1755 __sk_dst_get(struct sock *sk) 1756 { 1757 return rcu_dereference_check(sk->sk_dst_cache, 1758 lockdep_sock_is_held(sk)); 1759 } 1760 1761 static inline struct dst_entry * 1762 sk_dst_get(struct sock *sk) 1763 { 1764 struct dst_entry *dst; 1765 1766 rcu_read_lock(); 1767 dst = rcu_dereference(sk->sk_dst_cache); 1768 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 1769 dst = NULL; 1770 rcu_read_unlock(); 1771 return dst; 1772 } 1773 1774 static inline void dst_negative_advice(struct sock *sk) 1775 { 1776 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 1777 1778 sk_rethink_txhash(sk); 1779 1780 if (dst && dst->ops->negative_advice) { 1781 ndst = dst->ops->negative_advice(dst); 1782 1783 if (ndst != dst) { 1784 rcu_assign_pointer(sk->sk_dst_cache, ndst); 1785 sk_tx_queue_clear(sk); 1786 sk->sk_dst_pending_confirm = 0; 1787 } 1788 } 1789 } 1790 1791 static inline void 1792 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 1793 { 1794 struct dst_entry *old_dst; 1795 1796 sk_tx_queue_clear(sk); 1797 sk->sk_dst_pending_confirm = 0; 1798 old_dst = rcu_dereference_protected(sk->sk_dst_cache, 1799 lockdep_sock_is_held(sk)); 1800 rcu_assign_pointer(sk->sk_dst_cache, dst); 1801 dst_release(old_dst); 1802 } 1803 1804 static inline void 1805 sk_dst_set(struct sock *sk, struct dst_entry *dst) 1806 { 1807 struct dst_entry *old_dst; 1808 1809 sk_tx_queue_clear(sk); 1810 sk->sk_dst_pending_confirm = 0; 1811 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 1812 dst_release(old_dst); 1813 } 1814 1815 static inline void 1816 __sk_dst_reset(struct sock *sk) 1817 { 1818 __sk_dst_set(sk, NULL); 1819 } 1820 1821 static inline void 1822 sk_dst_reset(struct sock *sk) 1823 { 1824 sk_dst_set(sk, NULL); 1825 } 1826 1827 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 1828 1829 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 1830 1831 static inline void sk_dst_confirm(struct sock *sk) 1832 { 1833 if (!sk->sk_dst_pending_confirm) 1834 sk->sk_dst_pending_confirm = 1; 1835 } 1836 1837 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n) 1838 { 1839 if (skb_get_dst_pending_confirm(skb)) { 1840 struct sock *sk = skb->sk; 1841 unsigned long now = jiffies; 1842 1843 /* avoid dirtying neighbour */ 1844 if (n->confirmed != now) 1845 n->confirmed = now; 1846 if (sk && sk->sk_dst_pending_confirm) 1847 sk->sk_dst_pending_confirm = 0; 1848 } 1849 } 1850 1851 bool sk_mc_loop(struct sock *sk); 1852 1853 static inline bool sk_can_gso(const struct sock *sk) 1854 { 1855 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 1856 } 1857 1858 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 1859 1860 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags) 1861 { 1862 sk->sk_route_nocaps |= flags; 1863 sk->sk_route_caps &= ~flags; 1864 } 1865 1866 static inline bool sk_check_csum_caps(struct sock *sk) 1867 { 1868 return (sk->sk_route_caps & NETIF_F_HW_CSUM) || 1869 (sk->sk_family == PF_INET && 1870 (sk->sk_route_caps & NETIF_F_IP_CSUM)) || 1871 (sk->sk_family == PF_INET6 && 1872 (sk->sk_route_caps & NETIF_F_IPV6_CSUM)); 1873 } 1874 1875 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 1876 struct iov_iter *from, char *to, 1877 int copy, int offset) 1878 { 1879 if (skb->ip_summed == CHECKSUM_NONE) { 1880 __wsum csum = 0; 1881 if (!csum_and_copy_from_iter_full(to, copy, &csum, from)) 1882 return -EFAULT; 1883 skb->csum = csum_block_add(skb->csum, csum, offset); 1884 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 1885 if (!copy_from_iter_full_nocache(to, copy, from)) 1886 return -EFAULT; 1887 } else if (!copy_from_iter_full(to, copy, from)) 1888 return -EFAULT; 1889 1890 return 0; 1891 } 1892 1893 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 1894 struct iov_iter *from, int copy) 1895 { 1896 int err, offset = skb->len; 1897 1898 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 1899 copy, offset); 1900 if (err) 1901 __skb_trim(skb, offset); 1902 1903 return err; 1904 } 1905 1906 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 1907 struct sk_buff *skb, 1908 struct page *page, 1909 int off, int copy) 1910 { 1911 int err; 1912 1913 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 1914 copy, skb->len); 1915 if (err) 1916 return err; 1917 1918 skb->len += copy; 1919 skb->data_len += copy; 1920 skb->truesize += copy; 1921 sk->sk_wmem_queued += copy; 1922 sk_mem_charge(sk, copy); 1923 return 0; 1924 } 1925 1926 /** 1927 * sk_wmem_alloc_get - returns write allocations 1928 * @sk: socket 1929 * 1930 * Returns sk_wmem_alloc minus initial offset of one 1931 */ 1932 static inline int sk_wmem_alloc_get(const struct sock *sk) 1933 { 1934 return refcount_read(&sk->sk_wmem_alloc) - 1; 1935 } 1936 1937 /** 1938 * sk_rmem_alloc_get - returns read allocations 1939 * @sk: socket 1940 * 1941 * Returns sk_rmem_alloc 1942 */ 1943 static inline int sk_rmem_alloc_get(const struct sock *sk) 1944 { 1945 return atomic_read(&sk->sk_rmem_alloc); 1946 } 1947 1948 /** 1949 * sk_has_allocations - check if allocations are outstanding 1950 * @sk: socket 1951 * 1952 * Returns true if socket has write or read allocations 1953 */ 1954 static inline bool sk_has_allocations(const struct sock *sk) 1955 { 1956 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 1957 } 1958 1959 /** 1960 * skwq_has_sleeper - check if there are any waiting processes 1961 * @wq: struct socket_wq 1962 * 1963 * Returns true if socket_wq has waiting processes 1964 * 1965 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory 1966 * barrier call. They were added due to the race found within the tcp code. 1967 * 1968 * Consider following tcp code paths:: 1969 * 1970 * CPU1 CPU2 1971 * sys_select receive packet 1972 * ... ... 1973 * __add_wait_queue update tp->rcv_nxt 1974 * ... ... 1975 * tp->rcv_nxt check sock_def_readable 1976 * ... { 1977 * schedule rcu_read_lock(); 1978 * wq = rcu_dereference(sk->sk_wq); 1979 * if (wq && waitqueue_active(&wq->wait)) 1980 * wake_up_interruptible(&wq->wait) 1981 * ... 1982 * } 1983 * 1984 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 1985 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 1986 * could then endup calling schedule and sleep forever if there are no more 1987 * data on the socket. 1988 * 1989 */ 1990 static inline bool skwq_has_sleeper(struct socket_wq *wq) 1991 { 1992 return wq && wq_has_sleeper(&wq->wait); 1993 } 1994 1995 /** 1996 * sock_poll_wait - place memory barrier behind the poll_wait call. 1997 * @filp: file 1998 * @wait_address: socket wait queue 1999 * @p: poll_table 2000 * 2001 * See the comments in the wq_has_sleeper function. 2002 */ 2003 static inline void sock_poll_wait(struct file *filp, 2004 wait_queue_head_t *wait_address, poll_table *p) 2005 { 2006 if (!poll_does_not_wait(p) && wait_address) { 2007 poll_wait(filp, wait_address, p); 2008 /* We need to be sure we are in sync with the 2009 * socket flags modification. 2010 * 2011 * This memory barrier is paired in the wq_has_sleeper. 2012 */ 2013 smp_mb(); 2014 } 2015 } 2016 2017 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 2018 { 2019 if (sk->sk_txhash) { 2020 skb->l4_hash = 1; 2021 skb->hash = sk->sk_txhash; 2022 } 2023 } 2024 2025 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 2026 2027 /* 2028 * Queue a received datagram if it will fit. Stream and sequenced 2029 * protocols can't normally use this as they need to fit buffers in 2030 * and play with them. 2031 * 2032 * Inlined as it's very short and called for pretty much every 2033 * packet ever received. 2034 */ 2035 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 2036 { 2037 skb_orphan(skb); 2038 skb->sk = sk; 2039 skb->destructor = sock_rfree; 2040 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 2041 sk_mem_charge(sk, skb->truesize); 2042 } 2043 2044 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 2045 unsigned long expires); 2046 2047 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 2048 2049 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue, 2050 struct sk_buff *skb, unsigned int flags, 2051 void (*destructor)(struct sock *sk, 2052 struct sk_buff *skb)); 2053 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2054 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2055 2056 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 2057 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 2058 2059 /* 2060 * Recover an error report and clear atomically 2061 */ 2062 2063 static inline int sock_error(struct sock *sk) 2064 { 2065 int err; 2066 if (likely(!sk->sk_err)) 2067 return 0; 2068 err = xchg(&sk->sk_err, 0); 2069 return -err; 2070 } 2071 2072 static inline unsigned long sock_wspace(struct sock *sk) 2073 { 2074 int amt = 0; 2075 2076 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 2077 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc); 2078 if (amt < 0) 2079 amt = 0; 2080 } 2081 return amt; 2082 } 2083 2084 /* Note: 2085 * We use sk->sk_wq_raw, from contexts knowing this 2086 * pointer is not NULL and cannot disappear/change. 2087 */ 2088 static inline void sk_set_bit(int nr, struct sock *sk) 2089 { 2090 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2091 !sock_flag(sk, SOCK_FASYNC)) 2092 return; 2093 2094 set_bit(nr, &sk->sk_wq_raw->flags); 2095 } 2096 2097 static inline void sk_clear_bit(int nr, struct sock *sk) 2098 { 2099 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2100 !sock_flag(sk, SOCK_FASYNC)) 2101 return; 2102 2103 clear_bit(nr, &sk->sk_wq_raw->flags); 2104 } 2105 2106 static inline void sk_wake_async(const struct sock *sk, int how, int band) 2107 { 2108 if (sock_flag(sk, SOCK_FASYNC)) { 2109 rcu_read_lock(); 2110 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 2111 rcu_read_unlock(); 2112 } 2113 } 2114 2115 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 2116 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 2117 * Note: for send buffers, TCP works better if we can build two skbs at 2118 * minimum. 2119 */ 2120 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 2121 2122 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 2123 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 2124 2125 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 2126 { 2127 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) { 2128 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 2129 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF); 2130 } 2131 } 2132 2133 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp, 2134 bool force_schedule); 2135 2136 /** 2137 * sk_page_frag - return an appropriate page_frag 2138 * @sk: socket 2139 * 2140 * If socket allocation mode allows current thread to sleep, it means its 2141 * safe to use the per task page_frag instead of the per socket one. 2142 */ 2143 static inline struct page_frag *sk_page_frag(struct sock *sk) 2144 { 2145 if (gfpflags_allow_blocking(sk->sk_allocation)) 2146 return ¤t->task_frag; 2147 2148 return &sk->sk_frag; 2149 } 2150 2151 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2152 2153 /* 2154 * Default write policy as shown to user space via poll/select/SIGIO 2155 */ 2156 static inline bool sock_writeable(const struct sock *sk) 2157 { 2158 return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1); 2159 } 2160 2161 static inline gfp_t gfp_any(void) 2162 { 2163 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2164 } 2165 2166 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2167 { 2168 return noblock ? 0 : sk->sk_rcvtimeo; 2169 } 2170 2171 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2172 { 2173 return noblock ? 0 : sk->sk_sndtimeo; 2174 } 2175 2176 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2177 { 2178 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1; 2179 } 2180 2181 /* Alas, with timeout socket operations are not restartable. 2182 * Compare this to poll(). 2183 */ 2184 static inline int sock_intr_errno(long timeo) 2185 { 2186 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2187 } 2188 2189 struct sock_skb_cb { 2190 u32 dropcount; 2191 }; 2192 2193 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2194 * using skb->cb[] would keep using it directly and utilize its 2195 * alignement guarantee. 2196 */ 2197 #define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \ 2198 sizeof(struct sock_skb_cb))) 2199 2200 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2201 SOCK_SKB_CB_OFFSET)) 2202 2203 #define sock_skb_cb_check_size(size) \ 2204 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2205 2206 static inline void 2207 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2208 { 2209 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ? 2210 atomic_read(&sk->sk_drops) : 0; 2211 } 2212 2213 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) 2214 { 2215 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2216 2217 atomic_add(segs, &sk->sk_drops); 2218 } 2219 2220 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2221 struct sk_buff *skb); 2222 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2223 struct sk_buff *skb); 2224 2225 static inline void 2226 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2227 { 2228 ktime_t kt = skb->tstamp; 2229 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2230 2231 /* 2232 * generate control messages if 2233 * - receive time stamping in software requested 2234 * - software time stamp available and wanted 2235 * - hardware time stamps available and wanted 2236 */ 2237 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2238 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2239 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2240 (hwtstamps->hwtstamp && 2241 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2242 __sock_recv_timestamp(msg, sk, skb); 2243 else 2244 sk->sk_stamp = kt; 2245 2246 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2247 __sock_recv_wifi_status(msg, sk, skb); 2248 } 2249 2250 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2251 struct sk_buff *skb); 2252 2253 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC) 2254 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2255 struct sk_buff *skb) 2256 { 2257 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2258 (1UL << SOCK_RCVTSTAMP)) 2259 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2260 SOF_TIMESTAMPING_RAW_HARDWARE) 2261 2262 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2263 __sock_recv_ts_and_drops(msg, sk, skb); 2264 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) 2265 sk->sk_stamp = skb->tstamp; 2266 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) 2267 sk->sk_stamp = 0; 2268 } 2269 2270 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); 2271 2272 /** 2273 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2274 * @sk: socket sending this packet 2275 * @tsflags: timestamping flags to use 2276 * @tx_flags: completed with instructions for time stamping 2277 * 2278 * Note: callers should take care of initial ``*tx_flags`` value (usually 0) 2279 */ 2280 static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags, 2281 __u8 *tx_flags) 2282 { 2283 if (unlikely(tsflags)) 2284 __sock_tx_timestamp(tsflags, tx_flags); 2285 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2286 *tx_flags |= SKBTX_WIFI_STATUS; 2287 } 2288 2289 /** 2290 * sk_eat_skb - Release a skb if it is no longer needed 2291 * @sk: socket to eat this skb from 2292 * @skb: socket buffer to eat 2293 * 2294 * This routine must be called with interrupts disabled or with the socket 2295 * locked so that the sk_buff queue operation is ok. 2296 */ 2297 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2298 { 2299 __skb_unlink(skb, &sk->sk_receive_queue); 2300 __kfree_skb(skb); 2301 } 2302 2303 static inline 2304 struct net *sock_net(const struct sock *sk) 2305 { 2306 return read_pnet(&sk->sk_net); 2307 } 2308 2309 static inline 2310 void sock_net_set(struct sock *sk, struct net *net) 2311 { 2312 write_pnet(&sk->sk_net, net); 2313 } 2314 2315 static inline struct sock *skb_steal_sock(struct sk_buff *skb) 2316 { 2317 if (skb->sk) { 2318 struct sock *sk = skb->sk; 2319 2320 skb->destructor = NULL; 2321 skb->sk = NULL; 2322 return sk; 2323 } 2324 return NULL; 2325 } 2326 2327 /* This helper checks if a socket is a full socket, 2328 * ie _not_ a timewait or request socket. 2329 */ 2330 static inline bool sk_fullsock(const struct sock *sk) 2331 { 2332 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2333 } 2334 2335 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2336 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2337 */ 2338 static inline bool sk_listener(const struct sock *sk) 2339 { 2340 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2341 } 2342 2343 void sock_enable_timestamp(struct sock *sk, int flag); 2344 int sock_get_timestamp(struct sock *, struct timeval __user *); 2345 int sock_get_timestampns(struct sock *, struct timespec __user *); 2346 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2347 int type); 2348 2349 bool sk_ns_capable(const struct sock *sk, 2350 struct user_namespace *user_ns, int cap); 2351 bool sk_capable(const struct sock *sk, int cap); 2352 bool sk_net_capable(const struct sock *sk, int cap); 2353 2354 void sk_get_meminfo(const struct sock *sk, u32 *meminfo); 2355 2356 /* Take into consideration the size of the struct sk_buff overhead in the 2357 * determination of these values, since that is non-constant across 2358 * platforms. This makes socket queueing behavior and performance 2359 * not depend upon such differences. 2360 */ 2361 #define _SK_MEM_PACKETS 256 2362 #define _SK_MEM_OVERHEAD SKB_TRUESIZE(256) 2363 #define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2364 #define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2365 2366 extern __u32 sysctl_wmem_max; 2367 extern __u32 sysctl_rmem_max; 2368 2369 extern int sysctl_tstamp_allow_data; 2370 extern int sysctl_optmem_max; 2371 2372 extern __u32 sysctl_wmem_default; 2373 extern __u32 sysctl_rmem_default; 2374 2375 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto) 2376 { 2377 /* Does this proto have per netns sysctl_wmem ? */ 2378 if (proto->sysctl_wmem_offset) 2379 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset); 2380 2381 return *proto->sysctl_wmem; 2382 } 2383 2384 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto) 2385 { 2386 /* Does this proto have per netns sysctl_rmem ? */ 2387 if (proto->sysctl_rmem_offset) 2388 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset); 2389 2390 return *proto->sysctl_rmem; 2391 } 2392 2393 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10) 2394 * Some wifi drivers need to tweak it to get more chunks. 2395 * They can use this helper from their ndo_start_xmit() 2396 */ 2397 static inline void sk_pacing_shift_update(struct sock *sk, int val) 2398 { 2399 if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val) 2400 return; 2401 sk->sk_pacing_shift = val; 2402 } 2403 2404 /* if a socket is bound to a device, check that the given device 2405 * index is either the same or that the socket is bound to an L3 2406 * master device and the given device index is also enslaved to 2407 * that L3 master 2408 */ 2409 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif) 2410 { 2411 int mdif; 2412 2413 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif) 2414 return true; 2415 2416 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif); 2417 if (mdif && mdif == sk->sk_bound_dev_if) 2418 return true; 2419 2420 return false; 2421 } 2422 2423 #endif /* _SOCK_H */ 2424