1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the AF_INET socket handler. 8 * 9 * Version: @(#)sock.h 1.0.4 05/13/93 10 * 11 * Authors: Ross Biro 12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 13 * Corey Minyard <wf-rch!minyard@relay.EU.net> 14 * Florian La Roche <flla@stud.uni-sb.de> 15 * 16 * Fixes: 17 * Alan Cox : Volatiles in skbuff pointers. See 18 * skbuff comments. May be overdone, 19 * better to prove they can be removed 20 * than the reverse. 21 * Alan Cox : Added a zapped field for tcp to note 22 * a socket is reset and must stay shut up 23 * Alan Cox : New fields for options 24 * Pauline Middelink : identd support 25 * Alan Cox : Eliminate low level recv/recvfrom 26 * David S. Miller : New socket lookup architecture. 27 * Steve Whitehouse: Default routines for sock_ops 28 * Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made 29 * protinfo be just a void pointer, as the 30 * protocol specific parts were moved to 31 * respective headers and ipv4/v6, etc now 32 * use private slabcaches for its socks 33 * Pedro Hortas : New flags field for socket options 34 */ 35 #ifndef _SOCK_H 36 #define _SOCK_H 37 38 #include <linux/hardirq.h> 39 #include <linux/kernel.h> 40 #include <linux/list.h> 41 #include <linux/list_nulls.h> 42 #include <linux/timer.h> 43 #include <linux/cache.h> 44 #include <linux/bitops.h> 45 #include <linux/lockdep.h> 46 #include <linux/netdevice.h> 47 #include <linux/skbuff.h> /* struct sk_buff */ 48 #include <linux/mm.h> 49 #include <linux/security.h> 50 #include <linux/slab.h> 51 #include <linux/uaccess.h> 52 #include <linux/page_counter.h> 53 #include <linux/memcontrol.h> 54 #include <linux/static_key.h> 55 #include <linux/sched.h> 56 #include <linux/wait.h> 57 #include <linux/cgroup-defs.h> 58 #include <linux/rbtree.h> 59 #include <linux/rculist_nulls.h> 60 #include <linux/poll.h> 61 #include <linux/sockptr.h> 62 #include <linux/indirect_call_wrapper.h> 63 #include <linux/atomic.h> 64 #include <linux/refcount.h> 65 #include <linux/llist.h> 66 #include <net/dst.h> 67 #include <net/checksum.h> 68 #include <net/tcp_states.h> 69 #include <linux/net_tstamp.h> 70 #include <net/l3mdev.h> 71 #include <uapi/linux/socket.h> 72 73 /* 74 * This structure really needs to be cleaned up. 75 * Most of it is for TCP, and not used by any of 76 * the other protocols. 77 */ 78 79 /* Define this to get the SOCK_DBG debugging facility. */ 80 #define SOCK_DEBUGGING 81 #ifdef SOCK_DEBUGGING 82 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \ 83 printk(KERN_DEBUG msg); } while (0) 84 #else 85 /* Validate arguments and do nothing */ 86 static inline __printf(2, 3) 87 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...) 88 { 89 } 90 #endif 91 92 /* This is the per-socket lock. The spinlock provides a synchronization 93 * between user contexts and software interrupt processing, whereas the 94 * mini-semaphore synchronizes multiple users amongst themselves. 95 */ 96 typedef struct { 97 spinlock_t slock; 98 int owned; 99 wait_queue_head_t wq; 100 /* 101 * We express the mutex-alike socket_lock semantics 102 * to the lock validator by explicitly managing 103 * the slock as a lock variant (in addition to 104 * the slock itself): 105 */ 106 #ifdef CONFIG_DEBUG_LOCK_ALLOC 107 struct lockdep_map dep_map; 108 #endif 109 } socket_lock_t; 110 111 struct sock; 112 struct proto; 113 struct net; 114 115 typedef __u32 __bitwise __portpair; 116 typedef __u64 __bitwise __addrpair; 117 118 /** 119 * struct sock_common - minimal network layer representation of sockets 120 * @skc_daddr: Foreign IPv4 addr 121 * @skc_rcv_saddr: Bound local IPv4 addr 122 * @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr 123 * @skc_hash: hash value used with various protocol lookup tables 124 * @skc_u16hashes: two u16 hash values used by UDP lookup tables 125 * @skc_dport: placeholder for inet_dport/tw_dport 126 * @skc_num: placeholder for inet_num/tw_num 127 * @skc_portpair: __u32 union of @skc_dport & @skc_num 128 * @skc_family: network address family 129 * @skc_state: Connection state 130 * @skc_reuse: %SO_REUSEADDR setting 131 * @skc_reuseport: %SO_REUSEPORT setting 132 * @skc_ipv6only: socket is IPV6 only 133 * @skc_net_refcnt: socket is using net ref counting 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_v6_daddr: IPV6 destination address 140 * @skc_v6_rcv_saddr: IPV6 source address 141 * @skc_cookie: socket's cookie value 142 * @skc_node: main hash linkage for various protocol lookup tables 143 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol 144 * @skc_tx_queue_mapping: tx queue number for this connection 145 * @skc_rx_queue_mapping: rx queue number for this connection 146 * @skc_flags: place holder for sk_flags 147 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, 148 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings 149 * @skc_listener: connection request listener socket (aka rsk_listener) 150 * [union with @skc_flags] 151 * @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row 152 * [union with @skc_flags] 153 * @skc_incoming_cpu: record/match cpu processing incoming packets 154 * @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled) 155 * [union with @skc_incoming_cpu] 156 * @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number 157 * [union with @skc_incoming_cpu] 158 * @skc_refcnt: reference count 159 * 160 * This is the minimal network layer representation of sockets, the header 161 * for struct sock and struct inet_timewait_sock. 162 */ 163 struct sock_common { 164 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned 165 * address on 64bit arches : cf INET_MATCH() 166 */ 167 union { 168 __addrpair skc_addrpair; 169 struct { 170 __be32 skc_daddr; 171 __be32 skc_rcv_saddr; 172 }; 173 }; 174 union { 175 unsigned int skc_hash; 176 __u16 skc_u16hashes[2]; 177 }; 178 /* skc_dport && skc_num must be grouped as well */ 179 union { 180 __portpair skc_portpair; 181 struct { 182 __be16 skc_dport; 183 __u16 skc_num; 184 }; 185 }; 186 187 unsigned short skc_family; 188 volatile unsigned char skc_state; 189 unsigned char skc_reuse:4; 190 unsigned char skc_reuseport:1; 191 unsigned char skc_ipv6only:1; 192 unsigned char skc_net_refcnt:1; 193 int skc_bound_dev_if; 194 union { 195 struct hlist_node skc_bind_node; 196 struct hlist_node skc_portaddr_node; 197 }; 198 struct proto *skc_prot; 199 possible_net_t skc_net; 200 201 #if IS_ENABLED(CONFIG_IPV6) 202 struct in6_addr skc_v6_daddr; 203 struct in6_addr skc_v6_rcv_saddr; 204 #endif 205 206 atomic64_t skc_cookie; 207 208 /* following fields are padding to force 209 * offset(struct sock, sk_refcnt) == 128 on 64bit arches 210 * assuming IPV6 is enabled. We use this padding differently 211 * for different kind of 'sockets' 212 */ 213 union { 214 unsigned long skc_flags; 215 struct sock *skc_listener; /* request_sock */ 216 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */ 217 }; 218 /* 219 * fields between dontcopy_begin/dontcopy_end 220 * are not copied in sock_copy() 221 */ 222 /* private: */ 223 int skc_dontcopy_begin[0]; 224 /* public: */ 225 union { 226 struct hlist_node skc_node; 227 struct hlist_nulls_node skc_nulls_node; 228 }; 229 unsigned short skc_tx_queue_mapping; 230 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 231 unsigned short skc_rx_queue_mapping; 232 #endif 233 union { 234 int skc_incoming_cpu; 235 u32 skc_rcv_wnd; 236 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */ 237 }; 238 239 refcount_t skc_refcnt; 240 /* private: */ 241 int skc_dontcopy_end[0]; 242 union { 243 u32 skc_rxhash; 244 u32 skc_window_clamp; 245 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ 246 }; 247 /* public: */ 248 }; 249 250 struct bpf_local_storage; 251 struct sk_filter; 252 253 /** 254 * struct sock - network layer representation of sockets 255 * @__sk_common: shared layout with inet_timewait_sock 256 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN 257 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings 258 * @sk_lock: synchronizer 259 * @sk_kern_sock: True if sock is using kernel lock classes 260 * @sk_rcvbuf: size of receive buffer in bytes 261 * @sk_wq: sock wait queue and async head 262 * @sk_rx_dst: receive input route used by early demux 263 * @sk_rx_dst_ifindex: ifindex for @sk_rx_dst 264 * @sk_rx_dst_cookie: cookie for @sk_rx_dst 265 * @sk_dst_cache: destination cache 266 * @sk_dst_pending_confirm: need to confirm neighbour 267 * @sk_policy: flow policy 268 * @sk_receive_queue: incoming packets 269 * @sk_wmem_alloc: transmit queue bytes committed 270 * @sk_tsq_flags: TCP Small Queues flags 271 * @sk_write_queue: Packet sending queue 272 * @sk_omem_alloc: "o" is "option" or "other" 273 * @sk_wmem_queued: persistent queue size 274 * @sk_forward_alloc: space allocated forward 275 * @sk_reserved_mem: space reserved and non-reclaimable for the socket 276 * @sk_napi_id: id of the last napi context to receive data for sk 277 * @sk_ll_usec: usecs to busypoll when there is no data 278 * @sk_allocation: allocation mode 279 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler) 280 * @sk_pacing_status: Pacing status (requested, handled by sch_fq) 281 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE) 282 * @sk_sndbuf: size of send buffer in bytes 283 * @__sk_flags_offset: empty field used to determine location of bitfield 284 * @sk_padding: unused element for alignment 285 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets 286 * @sk_no_check_rx: allow zero checksum in RX packets 287 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) 288 * @sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden. 289 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) 290 * @sk_gso_max_size: Maximum GSO segment size to build 291 * @sk_gso_max_segs: Maximum number of GSO segments 292 * @sk_pacing_shift: scaling factor for TCP Small Queues 293 * @sk_lingertime: %SO_LINGER l_linger setting 294 * @sk_backlog: always used with the per-socket spinlock held 295 * @defer_list: head of llist storing skbs to be freed 296 * @sk_callback_lock: used with the callbacks in the end of this struct 297 * @sk_error_queue: rarely used 298 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, 299 * IPV6_ADDRFORM for instance) 300 * @sk_err: last error 301 * @sk_err_soft: errors that don't cause failure but are the cause of a 302 * persistent failure not just 'timed out' 303 * @sk_drops: raw/udp drops counter 304 * @sk_ack_backlog: current listen backlog 305 * @sk_max_ack_backlog: listen backlog set in listen() 306 * @sk_uid: user id of owner 307 * @sk_prefer_busy_poll: prefer busypolling over softirq processing 308 * @sk_busy_poll_budget: napi processing budget when busypolling 309 * @sk_priority: %SO_PRIORITY setting 310 * @sk_type: socket type (%SOCK_STREAM, etc) 311 * @sk_protocol: which protocol this socket belongs in this network family 312 * @sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred 313 * @sk_peer_pid: &struct pid for this socket's peer 314 * @sk_peer_cred: %SO_PEERCRED setting 315 * @sk_rcvlowat: %SO_RCVLOWAT setting 316 * @sk_rcvtimeo: %SO_RCVTIMEO setting 317 * @sk_sndtimeo: %SO_SNDTIMEO setting 318 * @sk_txhash: computed flow hash for use on transmit 319 * @sk_txrehash: enable TX hash rethink 320 * @sk_filter: socket filtering instructions 321 * @sk_timer: sock cleanup timer 322 * @sk_stamp: time stamp of last packet received 323 * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only 324 * @sk_tsflags: SO_TIMESTAMPING flags 325 * @sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock 326 * for timestamping 327 * @sk_tskey: counter to disambiguate concurrent tstamp requests 328 * @sk_zckey: counter to order MSG_ZEROCOPY notifications 329 * @sk_socket: Identd and reporting IO signals 330 * @sk_user_data: RPC layer private data 331 * @sk_frag: cached page frag 332 * @sk_peek_off: current peek_offset value 333 * @sk_send_head: front of stuff to transmit 334 * @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head] 335 * @sk_security: used by security modules 336 * @sk_mark: generic packet mark 337 * @sk_cgrp_data: cgroup data for this cgroup 338 * @sk_memcg: this socket's memory cgroup association 339 * @sk_write_pending: a write to stream socket waits to start 340 * @sk_state_change: callback to indicate change in the state of the sock 341 * @sk_data_ready: callback to indicate there is data to be processed 342 * @sk_write_space: callback to indicate there is bf sending space available 343 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE) 344 * @sk_backlog_rcv: callback to process the backlog 345 * @sk_validate_xmit_skb: ptr to an optional validate function 346 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0 347 * @sk_reuseport_cb: reuseport group container 348 * @sk_bpf_storage: ptr to cache and control for bpf_sk_storage 349 * @sk_rcu: used during RCU grace period 350 * @sk_clockid: clockid used by time-based scheduling (SO_TXTIME) 351 * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME 352 * @sk_txtime_report_errors: set report errors mode for SO_TXTIME 353 * @sk_txtime_unused: unused txtime flags 354 * @ns_tracker: tracker for netns reference 355 */ 356 struct sock { 357 /* 358 * Now struct inet_timewait_sock also uses sock_common, so please just 359 * don't add nothing before this first member (__sk_common) --acme 360 */ 361 struct sock_common __sk_common; 362 #define sk_node __sk_common.skc_node 363 #define sk_nulls_node __sk_common.skc_nulls_node 364 #define sk_refcnt __sk_common.skc_refcnt 365 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping 366 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 367 #define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping 368 #endif 369 370 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin 371 #define sk_dontcopy_end __sk_common.skc_dontcopy_end 372 #define sk_hash __sk_common.skc_hash 373 #define sk_portpair __sk_common.skc_portpair 374 #define sk_num __sk_common.skc_num 375 #define sk_dport __sk_common.skc_dport 376 #define sk_addrpair __sk_common.skc_addrpair 377 #define sk_daddr __sk_common.skc_daddr 378 #define sk_rcv_saddr __sk_common.skc_rcv_saddr 379 #define sk_family __sk_common.skc_family 380 #define sk_state __sk_common.skc_state 381 #define sk_reuse __sk_common.skc_reuse 382 #define sk_reuseport __sk_common.skc_reuseport 383 #define sk_ipv6only __sk_common.skc_ipv6only 384 #define sk_net_refcnt __sk_common.skc_net_refcnt 385 #define sk_bound_dev_if __sk_common.skc_bound_dev_if 386 #define sk_bind_node __sk_common.skc_bind_node 387 #define sk_prot __sk_common.skc_prot 388 #define sk_net __sk_common.skc_net 389 #define sk_v6_daddr __sk_common.skc_v6_daddr 390 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr 391 #define sk_cookie __sk_common.skc_cookie 392 #define sk_incoming_cpu __sk_common.skc_incoming_cpu 393 #define sk_flags __sk_common.skc_flags 394 #define sk_rxhash __sk_common.skc_rxhash 395 396 /* early demux fields */ 397 struct dst_entry __rcu *sk_rx_dst; 398 int sk_rx_dst_ifindex; 399 u32 sk_rx_dst_cookie; 400 401 socket_lock_t sk_lock; 402 atomic_t sk_drops; 403 int sk_rcvlowat; 404 struct sk_buff_head sk_error_queue; 405 struct sk_buff_head sk_receive_queue; 406 /* 407 * The backlog queue is special, it is always used with 408 * the per-socket spinlock held and requires low latency 409 * access. Therefore we special case it's implementation. 410 * Note : rmem_alloc is in this structure to fill a hole 411 * on 64bit arches, not because its logically part of 412 * backlog. 413 */ 414 struct { 415 atomic_t rmem_alloc; 416 int len; 417 struct sk_buff *head; 418 struct sk_buff *tail; 419 } sk_backlog; 420 struct llist_head defer_list; 421 422 #define sk_rmem_alloc sk_backlog.rmem_alloc 423 424 int sk_forward_alloc; 425 u32 sk_reserved_mem; 426 #ifdef CONFIG_NET_RX_BUSY_POLL 427 unsigned int sk_ll_usec; 428 /* ===== mostly read cache line ===== */ 429 unsigned int sk_napi_id; 430 #endif 431 int sk_rcvbuf; 432 433 struct sk_filter __rcu *sk_filter; 434 union { 435 struct socket_wq __rcu *sk_wq; 436 /* private: */ 437 struct socket_wq *sk_wq_raw; 438 /* public: */ 439 }; 440 #ifdef CONFIG_XFRM 441 struct xfrm_policy __rcu *sk_policy[2]; 442 #endif 443 444 struct dst_entry __rcu *sk_dst_cache; 445 atomic_t sk_omem_alloc; 446 int sk_sndbuf; 447 448 /* ===== cache line for TX ===== */ 449 int sk_wmem_queued; 450 refcount_t sk_wmem_alloc; 451 unsigned long sk_tsq_flags; 452 union { 453 struct sk_buff *sk_send_head; 454 struct rb_root tcp_rtx_queue; 455 }; 456 struct sk_buff_head sk_write_queue; 457 __s32 sk_peek_off; 458 int sk_write_pending; 459 __u32 sk_dst_pending_confirm; 460 u32 sk_pacing_status; /* see enum sk_pacing */ 461 long sk_sndtimeo; 462 struct timer_list sk_timer; 463 __u32 sk_priority; 464 __u32 sk_mark; 465 unsigned long sk_pacing_rate; /* bytes per second */ 466 unsigned long sk_max_pacing_rate; 467 struct page_frag sk_frag; 468 netdev_features_t sk_route_caps; 469 int sk_gso_type; 470 unsigned int sk_gso_max_size; 471 gfp_t sk_allocation; 472 __u32 sk_txhash; 473 474 /* 475 * Because of non atomicity rules, all 476 * changes are protected by socket lock. 477 */ 478 u8 sk_gso_disabled : 1, 479 sk_kern_sock : 1, 480 sk_no_check_tx : 1, 481 sk_no_check_rx : 1, 482 sk_userlocks : 4; 483 u8 sk_pacing_shift; 484 u16 sk_type; 485 u16 sk_protocol; 486 u16 sk_gso_max_segs; 487 unsigned long sk_lingertime; 488 struct proto *sk_prot_creator; 489 rwlock_t sk_callback_lock; 490 int sk_err, 491 sk_err_soft; 492 u32 sk_ack_backlog; 493 u32 sk_max_ack_backlog; 494 kuid_t sk_uid; 495 u8 sk_txrehash; 496 #ifdef CONFIG_NET_RX_BUSY_POLL 497 u8 sk_prefer_busy_poll; 498 u16 sk_busy_poll_budget; 499 #endif 500 spinlock_t sk_peer_lock; 501 int sk_bind_phc; 502 struct pid *sk_peer_pid; 503 const struct cred *sk_peer_cred; 504 505 long sk_rcvtimeo; 506 ktime_t sk_stamp; 507 #if BITS_PER_LONG==32 508 seqlock_t sk_stamp_seq; 509 #endif 510 u16 sk_tsflags; 511 u8 sk_shutdown; 512 atomic_t sk_tskey; 513 atomic_t sk_zckey; 514 515 u8 sk_clockid; 516 u8 sk_txtime_deadline_mode : 1, 517 sk_txtime_report_errors : 1, 518 sk_txtime_unused : 6; 519 520 struct socket *sk_socket; 521 void *sk_user_data; 522 #ifdef CONFIG_SECURITY 523 void *sk_security; 524 #endif 525 struct sock_cgroup_data sk_cgrp_data; 526 struct mem_cgroup *sk_memcg; 527 void (*sk_state_change)(struct sock *sk); 528 void (*sk_data_ready)(struct sock *sk); 529 void (*sk_write_space)(struct sock *sk); 530 void (*sk_error_report)(struct sock *sk); 531 int (*sk_backlog_rcv)(struct sock *sk, 532 struct sk_buff *skb); 533 #ifdef CONFIG_SOCK_VALIDATE_XMIT 534 struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk, 535 struct net_device *dev, 536 struct sk_buff *skb); 537 #endif 538 void (*sk_destruct)(struct sock *sk); 539 struct sock_reuseport __rcu *sk_reuseport_cb; 540 #ifdef CONFIG_BPF_SYSCALL 541 struct bpf_local_storage __rcu *sk_bpf_storage; 542 #endif 543 struct rcu_head sk_rcu; 544 netns_tracker ns_tracker; 545 }; 546 547 enum sk_pacing { 548 SK_PACING_NONE = 0, 549 SK_PACING_NEEDED = 1, 550 SK_PACING_FQ = 2, 551 }; 552 553 /* Pointer stored in sk_user_data might not be suitable for copying 554 * when cloning the socket. For instance, it can point to a reference 555 * counted object. sk_user_data bottom bit is set if pointer must not 556 * be copied. 557 */ 558 #define SK_USER_DATA_NOCOPY 1UL 559 #define SK_USER_DATA_BPF 2UL /* Managed by BPF */ 560 #define SK_USER_DATA_PTRMASK ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF) 561 562 /** 563 * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied 564 * @sk: socket 565 */ 566 static inline bool sk_user_data_is_nocopy(const struct sock *sk) 567 { 568 return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY); 569 } 570 571 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) 572 573 #define rcu_dereference_sk_user_data(sk) \ 574 ({ \ 575 void *__tmp = rcu_dereference(__sk_user_data((sk))); \ 576 (void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK); \ 577 }) 578 #define rcu_assign_sk_user_data(sk, ptr) \ 579 ({ \ 580 uintptr_t __tmp = (uintptr_t)(ptr); \ 581 WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \ 582 rcu_assign_pointer(__sk_user_data((sk)), __tmp); \ 583 }) 584 #define rcu_assign_sk_user_data_nocopy(sk, ptr) \ 585 ({ \ 586 uintptr_t __tmp = (uintptr_t)(ptr); \ 587 WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \ 588 rcu_assign_pointer(__sk_user_data((sk)), \ 589 __tmp | SK_USER_DATA_NOCOPY); \ 590 }) 591 592 static inline 593 struct net *sock_net(const struct sock *sk) 594 { 595 return read_pnet(&sk->sk_net); 596 } 597 598 static inline 599 void sock_net_set(struct sock *sk, struct net *net) 600 { 601 write_pnet(&sk->sk_net, net); 602 } 603 604 /* 605 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK 606 * or not whether his port will be reused by someone else. SK_FORCE_REUSE 607 * on a socket means that the socket will reuse everybody else's port 608 * without looking at the other's sk_reuse value. 609 */ 610 611 #define SK_NO_REUSE 0 612 #define SK_CAN_REUSE 1 613 #define SK_FORCE_REUSE 2 614 615 int sk_set_peek_off(struct sock *sk, int val); 616 617 static inline int sk_peek_offset(struct sock *sk, int flags) 618 { 619 if (unlikely(flags & MSG_PEEK)) { 620 return READ_ONCE(sk->sk_peek_off); 621 } 622 623 return 0; 624 } 625 626 static inline void sk_peek_offset_bwd(struct sock *sk, int val) 627 { 628 s32 off = READ_ONCE(sk->sk_peek_off); 629 630 if (unlikely(off >= 0)) { 631 off = max_t(s32, off - val, 0); 632 WRITE_ONCE(sk->sk_peek_off, off); 633 } 634 } 635 636 static inline void sk_peek_offset_fwd(struct sock *sk, int val) 637 { 638 sk_peek_offset_bwd(sk, -val); 639 } 640 641 /* 642 * Hashed lists helper routines 643 */ 644 static inline struct sock *sk_entry(const struct hlist_node *node) 645 { 646 return hlist_entry(node, struct sock, sk_node); 647 } 648 649 static inline struct sock *__sk_head(const struct hlist_head *head) 650 { 651 return hlist_entry(head->first, struct sock, sk_node); 652 } 653 654 static inline struct sock *sk_head(const struct hlist_head *head) 655 { 656 return hlist_empty(head) ? NULL : __sk_head(head); 657 } 658 659 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head) 660 { 661 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node); 662 } 663 664 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head) 665 { 666 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head); 667 } 668 669 static inline struct sock *sk_next(const struct sock *sk) 670 { 671 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node); 672 } 673 674 static inline struct sock *sk_nulls_next(const struct sock *sk) 675 { 676 return (!is_a_nulls(sk->sk_nulls_node.next)) ? 677 hlist_nulls_entry(sk->sk_nulls_node.next, 678 struct sock, sk_nulls_node) : 679 NULL; 680 } 681 682 static inline bool sk_unhashed(const struct sock *sk) 683 { 684 return hlist_unhashed(&sk->sk_node); 685 } 686 687 static inline bool sk_hashed(const struct sock *sk) 688 { 689 return !sk_unhashed(sk); 690 } 691 692 static inline void sk_node_init(struct hlist_node *node) 693 { 694 node->pprev = NULL; 695 } 696 697 static inline void sk_nulls_node_init(struct hlist_nulls_node *node) 698 { 699 node->pprev = NULL; 700 } 701 702 static inline void __sk_del_node(struct sock *sk) 703 { 704 __hlist_del(&sk->sk_node); 705 } 706 707 /* NB: equivalent to hlist_del_init_rcu */ 708 static inline bool __sk_del_node_init(struct sock *sk) 709 { 710 if (sk_hashed(sk)) { 711 __sk_del_node(sk); 712 sk_node_init(&sk->sk_node); 713 return true; 714 } 715 return false; 716 } 717 718 /* Grab socket reference count. This operation is valid only 719 when sk is ALREADY grabbed f.e. it is found in hash table 720 or a list and the lookup is made under lock preventing hash table 721 modifications. 722 */ 723 724 static __always_inline void sock_hold(struct sock *sk) 725 { 726 refcount_inc(&sk->sk_refcnt); 727 } 728 729 /* Ungrab socket in the context, which assumes that socket refcnt 730 cannot hit zero, f.e. it is true in context of any socketcall. 731 */ 732 static __always_inline void __sock_put(struct sock *sk) 733 { 734 refcount_dec(&sk->sk_refcnt); 735 } 736 737 static inline bool sk_del_node_init(struct sock *sk) 738 { 739 bool rc = __sk_del_node_init(sk); 740 741 if (rc) { 742 /* paranoid for a while -acme */ 743 WARN_ON(refcount_read(&sk->sk_refcnt) == 1); 744 __sock_put(sk); 745 } 746 return rc; 747 } 748 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk) 749 750 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk) 751 { 752 if (sk_hashed(sk)) { 753 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 754 return true; 755 } 756 return false; 757 } 758 759 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk) 760 { 761 bool rc = __sk_nulls_del_node_init_rcu(sk); 762 763 if (rc) { 764 /* paranoid for a while -acme */ 765 WARN_ON(refcount_read(&sk->sk_refcnt) == 1); 766 __sock_put(sk); 767 } 768 return rc; 769 } 770 771 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list) 772 { 773 hlist_add_head(&sk->sk_node, list); 774 } 775 776 static inline void sk_add_node(struct sock *sk, struct hlist_head *list) 777 { 778 sock_hold(sk); 779 __sk_add_node(sk, list); 780 } 781 782 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 783 { 784 sock_hold(sk); 785 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 786 sk->sk_family == AF_INET6) 787 hlist_add_tail_rcu(&sk->sk_node, list); 788 else 789 hlist_add_head_rcu(&sk->sk_node, list); 790 } 791 792 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list) 793 { 794 sock_hold(sk); 795 hlist_add_tail_rcu(&sk->sk_node, list); 796 } 797 798 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 799 { 800 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); 801 } 802 803 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list) 804 { 805 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list); 806 } 807 808 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) 809 { 810 sock_hold(sk); 811 __sk_nulls_add_node_rcu(sk, list); 812 } 813 814 static inline void __sk_del_bind_node(struct sock *sk) 815 { 816 __hlist_del(&sk->sk_bind_node); 817 } 818 819 static inline void sk_add_bind_node(struct sock *sk, 820 struct hlist_head *list) 821 { 822 hlist_add_head(&sk->sk_bind_node, list); 823 } 824 825 #define sk_for_each(__sk, list) \ 826 hlist_for_each_entry(__sk, list, sk_node) 827 #define sk_for_each_rcu(__sk, list) \ 828 hlist_for_each_entry_rcu(__sk, list, sk_node) 829 #define sk_nulls_for_each(__sk, node, list) \ 830 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 831 #define sk_nulls_for_each_rcu(__sk, node, list) \ 832 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 833 #define sk_for_each_from(__sk) \ 834 hlist_for_each_entry_from(__sk, sk_node) 835 #define sk_nulls_for_each_from(__sk, node) \ 836 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \ 837 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node) 838 #define sk_for_each_safe(__sk, tmp, list) \ 839 hlist_for_each_entry_safe(__sk, tmp, list, sk_node) 840 #define sk_for_each_bound(__sk, list) \ 841 hlist_for_each_entry(__sk, list, sk_bind_node) 842 843 /** 844 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset 845 * @tpos: the type * to use as a loop cursor. 846 * @pos: the &struct hlist_node to use as a loop cursor. 847 * @head: the head for your list. 848 * @offset: offset of hlist_node within the struct. 849 * 850 */ 851 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \ 852 for (pos = rcu_dereference(hlist_first_rcu(head)); \ 853 pos != NULL && \ 854 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ 855 pos = rcu_dereference(hlist_next_rcu(pos))) 856 857 static inline struct user_namespace *sk_user_ns(struct sock *sk) 858 { 859 /* Careful only use this in a context where these parameters 860 * can not change and must all be valid, such as recvmsg from 861 * userspace. 862 */ 863 return sk->sk_socket->file->f_cred->user_ns; 864 } 865 866 /* Sock flags */ 867 enum sock_flags { 868 SOCK_DEAD, 869 SOCK_DONE, 870 SOCK_URGINLINE, 871 SOCK_KEEPOPEN, 872 SOCK_LINGER, 873 SOCK_DESTROY, 874 SOCK_BROADCAST, 875 SOCK_TIMESTAMP, 876 SOCK_ZAPPED, 877 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ 878 SOCK_DBG, /* %SO_DEBUG setting */ 879 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ 880 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */ 881 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ 882 SOCK_MEMALLOC, /* VM depends on this socket for swapping */ 883 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ 884 SOCK_FASYNC, /* fasync() active */ 885 SOCK_RXQ_OVFL, 886 SOCK_ZEROCOPY, /* buffers from userspace */ 887 SOCK_WIFI_STATUS, /* push wifi status to userspace */ 888 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS. 889 * Will use last 4 bytes of packet sent from 890 * user-space instead. 891 */ 892 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ 893 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ 894 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */ 895 SOCK_TXTIME, 896 SOCK_XDP, /* XDP is attached */ 897 SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */ 898 }; 899 900 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) 901 902 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk) 903 { 904 nsk->sk_flags = osk->sk_flags; 905 } 906 907 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag) 908 { 909 __set_bit(flag, &sk->sk_flags); 910 } 911 912 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag) 913 { 914 __clear_bit(flag, &sk->sk_flags); 915 } 916 917 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit, 918 int valbool) 919 { 920 if (valbool) 921 sock_set_flag(sk, bit); 922 else 923 sock_reset_flag(sk, bit); 924 } 925 926 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag) 927 { 928 return test_bit(flag, &sk->sk_flags); 929 } 930 931 #ifdef CONFIG_NET 932 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key); 933 static inline int sk_memalloc_socks(void) 934 { 935 return static_branch_unlikely(&memalloc_socks_key); 936 } 937 938 void __receive_sock(struct file *file); 939 #else 940 941 static inline int sk_memalloc_socks(void) 942 { 943 return 0; 944 } 945 946 static inline void __receive_sock(struct file *file) 947 { } 948 #endif 949 950 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) 951 { 952 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC); 953 } 954 955 static inline void sk_acceptq_removed(struct sock *sk) 956 { 957 WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1); 958 } 959 960 static inline void sk_acceptq_added(struct sock *sk) 961 { 962 WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1); 963 } 964 965 /* Note: If you think the test should be: 966 * return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog); 967 * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.") 968 */ 969 static inline bool sk_acceptq_is_full(const struct sock *sk) 970 { 971 return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog); 972 } 973 974 /* 975 * Compute minimal free write space needed to queue new packets. 976 */ 977 static inline int sk_stream_min_wspace(const struct sock *sk) 978 { 979 return READ_ONCE(sk->sk_wmem_queued) >> 1; 980 } 981 982 static inline int sk_stream_wspace(const struct sock *sk) 983 { 984 return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued); 985 } 986 987 static inline void sk_wmem_queued_add(struct sock *sk, int val) 988 { 989 WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val); 990 } 991 992 void sk_stream_write_space(struct sock *sk); 993 994 /* OOB backlog add */ 995 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 996 { 997 /* dont let skb dst not refcounted, we are going to leave rcu lock */ 998 skb_dst_force(skb); 999 1000 if (!sk->sk_backlog.tail) 1001 WRITE_ONCE(sk->sk_backlog.head, skb); 1002 else 1003 sk->sk_backlog.tail->next = skb; 1004 1005 WRITE_ONCE(sk->sk_backlog.tail, skb); 1006 skb->next = NULL; 1007 } 1008 1009 /* 1010 * Take into account size of receive queue and backlog queue 1011 * Do not take into account this skb truesize, 1012 * to allow even a single big packet to come. 1013 */ 1014 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit) 1015 { 1016 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); 1017 1018 return qsize > limit; 1019 } 1020 1021 /* The per-socket spinlock must be held here. */ 1022 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb, 1023 unsigned int limit) 1024 { 1025 if (sk_rcvqueues_full(sk, limit)) 1026 return -ENOBUFS; 1027 1028 /* 1029 * If the skb was allocated from pfmemalloc reserves, only 1030 * allow SOCK_MEMALLOC sockets to use it as this socket is 1031 * helping free memory 1032 */ 1033 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC)) 1034 return -ENOMEM; 1035 1036 __sk_add_backlog(sk, skb); 1037 sk->sk_backlog.len += skb->truesize; 1038 return 0; 1039 } 1040 1041 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb); 1042 1043 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)); 1044 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)); 1045 1046 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) 1047 { 1048 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) 1049 return __sk_backlog_rcv(sk, skb); 1050 1051 return INDIRECT_CALL_INET(sk->sk_backlog_rcv, 1052 tcp_v6_do_rcv, 1053 tcp_v4_do_rcv, 1054 sk, skb); 1055 } 1056 1057 static inline void sk_incoming_cpu_update(struct sock *sk) 1058 { 1059 int cpu = raw_smp_processor_id(); 1060 1061 if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu)) 1062 WRITE_ONCE(sk->sk_incoming_cpu, cpu); 1063 } 1064 1065 static inline void sock_rps_record_flow_hash(__u32 hash) 1066 { 1067 #ifdef CONFIG_RPS 1068 struct rps_sock_flow_table *sock_flow_table; 1069 1070 rcu_read_lock(); 1071 sock_flow_table = rcu_dereference(rps_sock_flow_table); 1072 rps_record_sock_flow(sock_flow_table, hash); 1073 rcu_read_unlock(); 1074 #endif 1075 } 1076 1077 static inline void sock_rps_record_flow(const struct sock *sk) 1078 { 1079 #ifdef CONFIG_RPS 1080 if (static_branch_unlikely(&rfs_needed)) { 1081 /* Reading sk->sk_rxhash might incur an expensive cache line 1082 * miss. 1083 * 1084 * TCP_ESTABLISHED does cover almost all states where RFS 1085 * might be useful, and is cheaper [1] than testing : 1086 * IPv4: inet_sk(sk)->inet_daddr 1087 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr) 1088 * OR an additional socket flag 1089 * [1] : sk_state and sk_prot are in the same cache line. 1090 */ 1091 if (sk->sk_state == TCP_ESTABLISHED) 1092 sock_rps_record_flow_hash(sk->sk_rxhash); 1093 } 1094 #endif 1095 } 1096 1097 static inline void sock_rps_save_rxhash(struct sock *sk, 1098 const struct sk_buff *skb) 1099 { 1100 #ifdef CONFIG_RPS 1101 if (unlikely(sk->sk_rxhash != skb->hash)) 1102 sk->sk_rxhash = skb->hash; 1103 #endif 1104 } 1105 1106 static inline void sock_rps_reset_rxhash(struct sock *sk) 1107 { 1108 #ifdef CONFIG_RPS 1109 sk->sk_rxhash = 0; 1110 #endif 1111 } 1112 1113 #define sk_wait_event(__sk, __timeo, __condition, __wait) \ 1114 ({ int __rc; \ 1115 release_sock(__sk); \ 1116 __rc = __condition; \ 1117 if (!__rc) { \ 1118 *(__timeo) = wait_woken(__wait, \ 1119 TASK_INTERRUPTIBLE, \ 1120 *(__timeo)); \ 1121 } \ 1122 sched_annotate_sleep(); \ 1123 lock_sock(__sk); \ 1124 __rc = __condition; \ 1125 __rc; \ 1126 }) 1127 1128 int sk_stream_wait_connect(struct sock *sk, long *timeo_p); 1129 int sk_stream_wait_memory(struct sock *sk, long *timeo_p); 1130 void sk_stream_wait_close(struct sock *sk, long timeo_p); 1131 int sk_stream_error(struct sock *sk, int flags, int err); 1132 void sk_stream_kill_queues(struct sock *sk); 1133 void sk_set_memalloc(struct sock *sk); 1134 void sk_clear_memalloc(struct sock *sk); 1135 1136 void __sk_flush_backlog(struct sock *sk); 1137 1138 static inline bool sk_flush_backlog(struct sock *sk) 1139 { 1140 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) { 1141 __sk_flush_backlog(sk); 1142 return true; 1143 } 1144 return false; 1145 } 1146 1147 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); 1148 1149 struct request_sock_ops; 1150 struct timewait_sock_ops; 1151 struct inet_hashinfo; 1152 struct raw_hashinfo; 1153 struct smc_hashinfo; 1154 struct module; 1155 struct sk_psock; 1156 1157 /* 1158 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes 1159 * un-modified. Special care is taken when initializing object to zero. 1160 */ 1161 static inline void sk_prot_clear_nulls(struct sock *sk, int size) 1162 { 1163 if (offsetof(struct sock, sk_node.next) != 0) 1164 memset(sk, 0, offsetof(struct sock, sk_node.next)); 1165 memset(&sk->sk_node.pprev, 0, 1166 size - offsetof(struct sock, sk_node.pprev)); 1167 } 1168 1169 /* Networking protocol blocks we attach to sockets. 1170 * socket layer -> transport layer interface 1171 */ 1172 struct proto { 1173 void (*close)(struct sock *sk, 1174 long timeout); 1175 int (*pre_connect)(struct sock *sk, 1176 struct sockaddr *uaddr, 1177 int addr_len); 1178 int (*connect)(struct sock *sk, 1179 struct sockaddr *uaddr, 1180 int addr_len); 1181 int (*disconnect)(struct sock *sk, int flags); 1182 1183 struct sock * (*accept)(struct sock *sk, int flags, int *err, 1184 bool kern); 1185 1186 int (*ioctl)(struct sock *sk, int cmd, 1187 unsigned long arg); 1188 int (*init)(struct sock *sk); 1189 void (*destroy)(struct sock *sk); 1190 void (*shutdown)(struct sock *sk, int how); 1191 int (*setsockopt)(struct sock *sk, int level, 1192 int optname, sockptr_t optval, 1193 unsigned int optlen); 1194 int (*getsockopt)(struct sock *sk, int level, 1195 int optname, char __user *optval, 1196 int __user *option); 1197 void (*keepalive)(struct sock *sk, int valbool); 1198 #ifdef CONFIG_COMPAT 1199 int (*compat_ioctl)(struct sock *sk, 1200 unsigned int cmd, unsigned long arg); 1201 #endif 1202 int (*sendmsg)(struct sock *sk, struct msghdr *msg, 1203 size_t len); 1204 int (*recvmsg)(struct sock *sk, struct msghdr *msg, 1205 size_t len, int noblock, int flags, 1206 int *addr_len); 1207 int (*sendpage)(struct sock *sk, struct page *page, 1208 int offset, size_t size, int flags); 1209 int (*bind)(struct sock *sk, 1210 struct sockaddr *addr, int addr_len); 1211 int (*bind_add)(struct sock *sk, 1212 struct sockaddr *addr, int addr_len); 1213 1214 int (*backlog_rcv) (struct sock *sk, 1215 struct sk_buff *skb); 1216 bool (*bpf_bypass_getsockopt)(int level, 1217 int optname); 1218 1219 void (*release_cb)(struct sock *sk); 1220 1221 /* Keeping track of sk's, looking them up, and port selection methods. */ 1222 int (*hash)(struct sock *sk); 1223 void (*unhash)(struct sock *sk); 1224 void (*rehash)(struct sock *sk); 1225 int (*get_port)(struct sock *sk, unsigned short snum); 1226 void (*put_port)(struct sock *sk); 1227 #ifdef CONFIG_BPF_SYSCALL 1228 int (*psock_update_sk_prot)(struct sock *sk, 1229 struct sk_psock *psock, 1230 bool restore); 1231 #endif 1232 1233 /* Keeping track of sockets in use */ 1234 #ifdef CONFIG_PROC_FS 1235 unsigned int inuse_idx; 1236 #endif 1237 1238 #if IS_ENABLED(CONFIG_MPTCP) 1239 int (*forward_alloc_get)(const struct sock *sk); 1240 #endif 1241 1242 bool (*stream_memory_free)(const struct sock *sk, int wake); 1243 bool (*sock_is_readable)(struct sock *sk); 1244 /* Memory pressure */ 1245 void (*enter_memory_pressure)(struct sock *sk); 1246 void (*leave_memory_pressure)(struct sock *sk); 1247 atomic_long_t *memory_allocated; /* Current allocated memory. */ 1248 struct percpu_counter *sockets_allocated; /* Current number of sockets. */ 1249 1250 /* 1251 * Pressure flag: try to collapse. 1252 * Technical note: it is used by multiple contexts non atomically. 1253 * All the __sk_mem_schedule() is of this nature: accounting 1254 * is strict, actions are advisory and have some latency. 1255 */ 1256 unsigned long *memory_pressure; 1257 long *sysctl_mem; 1258 1259 int *sysctl_wmem; 1260 int *sysctl_rmem; 1261 u32 sysctl_wmem_offset; 1262 u32 sysctl_rmem_offset; 1263 1264 int max_header; 1265 bool no_autobind; 1266 1267 struct kmem_cache *slab; 1268 unsigned int obj_size; 1269 slab_flags_t slab_flags; 1270 unsigned int useroffset; /* Usercopy region offset */ 1271 unsigned int usersize; /* Usercopy region size */ 1272 1273 unsigned int __percpu *orphan_count; 1274 1275 struct request_sock_ops *rsk_prot; 1276 struct timewait_sock_ops *twsk_prot; 1277 1278 union { 1279 struct inet_hashinfo *hashinfo; 1280 struct udp_table *udp_table; 1281 struct raw_hashinfo *raw_hash; 1282 struct smc_hashinfo *smc_hash; 1283 } h; 1284 1285 struct module *owner; 1286 1287 char name[32]; 1288 1289 struct list_head node; 1290 #ifdef SOCK_REFCNT_DEBUG 1291 atomic_t socks; 1292 #endif 1293 int (*diag_destroy)(struct sock *sk, int err); 1294 } __randomize_layout; 1295 1296 int proto_register(struct proto *prot, int alloc_slab); 1297 void proto_unregister(struct proto *prot); 1298 int sock_load_diag_module(int family, int protocol); 1299 1300 #ifdef SOCK_REFCNT_DEBUG 1301 static inline void sk_refcnt_debug_inc(struct sock *sk) 1302 { 1303 atomic_inc(&sk->sk_prot->socks); 1304 } 1305 1306 static inline void sk_refcnt_debug_dec(struct sock *sk) 1307 { 1308 atomic_dec(&sk->sk_prot->socks); 1309 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n", 1310 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks)); 1311 } 1312 1313 static inline void sk_refcnt_debug_release(const struct sock *sk) 1314 { 1315 if (refcount_read(&sk->sk_refcnt) != 1) 1316 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", 1317 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt)); 1318 } 1319 #else /* SOCK_REFCNT_DEBUG */ 1320 #define sk_refcnt_debug_inc(sk) do { } while (0) 1321 #define sk_refcnt_debug_dec(sk) do { } while (0) 1322 #define sk_refcnt_debug_release(sk) do { } while (0) 1323 #endif /* SOCK_REFCNT_DEBUG */ 1324 1325 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake)); 1326 1327 static inline int sk_forward_alloc_get(const struct sock *sk) 1328 { 1329 #if IS_ENABLED(CONFIG_MPTCP) 1330 if (sk->sk_prot->forward_alloc_get) 1331 return sk->sk_prot->forward_alloc_get(sk); 1332 #endif 1333 return sk->sk_forward_alloc; 1334 } 1335 1336 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake) 1337 { 1338 if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf)) 1339 return false; 1340 1341 return sk->sk_prot->stream_memory_free ? 1342 INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free, 1343 tcp_stream_memory_free, sk, wake) : true; 1344 } 1345 1346 static inline bool sk_stream_memory_free(const struct sock *sk) 1347 { 1348 return __sk_stream_memory_free(sk, 0); 1349 } 1350 1351 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake) 1352 { 1353 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && 1354 __sk_stream_memory_free(sk, wake); 1355 } 1356 1357 static inline bool sk_stream_is_writeable(const struct sock *sk) 1358 { 1359 return __sk_stream_is_writeable(sk, 0); 1360 } 1361 1362 static inline int sk_under_cgroup_hierarchy(struct sock *sk, 1363 struct cgroup *ancestor) 1364 { 1365 #ifdef CONFIG_SOCK_CGROUP_DATA 1366 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), 1367 ancestor); 1368 #else 1369 return -ENOTSUPP; 1370 #endif 1371 } 1372 1373 static inline bool sk_has_memory_pressure(const struct sock *sk) 1374 { 1375 return sk->sk_prot->memory_pressure != NULL; 1376 } 1377 1378 static inline bool sk_under_memory_pressure(const struct sock *sk) 1379 { 1380 if (!sk->sk_prot->memory_pressure) 1381 return false; 1382 1383 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 1384 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 1385 return true; 1386 1387 return !!*sk->sk_prot->memory_pressure; 1388 } 1389 1390 static inline long 1391 sk_memory_allocated(const struct sock *sk) 1392 { 1393 return atomic_long_read(sk->sk_prot->memory_allocated); 1394 } 1395 1396 static inline long 1397 sk_memory_allocated_add(struct sock *sk, int amt) 1398 { 1399 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated); 1400 } 1401 1402 static inline void 1403 sk_memory_allocated_sub(struct sock *sk, int amt) 1404 { 1405 atomic_long_sub(amt, sk->sk_prot->memory_allocated); 1406 } 1407 1408 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16 1409 1410 static inline void sk_sockets_allocated_dec(struct sock *sk) 1411 { 1412 percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1, 1413 SK_ALLOC_PERCPU_COUNTER_BATCH); 1414 } 1415 1416 static inline void sk_sockets_allocated_inc(struct sock *sk) 1417 { 1418 percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1, 1419 SK_ALLOC_PERCPU_COUNTER_BATCH); 1420 } 1421 1422 static inline u64 1423 sk_sockets_allocated_read_positive(struct sock *sk) 1424 { 1425 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated); 1426 } 1427 1428 static inline int 1429 proto_sockets_allocated_sum_positive(struct proto *prot) 1430 { 1431 return percpu_counter_sum_positive(prot->sockets_allocated); 1432 } 1433 1434 static inline long 1435 proto_memory_allocated(struct proto *prot) 1436 { 1437 return atomic_long_read(prot->memory_allocated); 1438 } 1439 1440 static inline bool 1441 proto_memory_pressure(struct proto *prot) 1442 { 1443 if (!prot->memory_pressure) 1444 return false; 1445 return !!*prot->memory_pressure; 1446 } 1447 1448 1449 #ifdef CONFIG_PROC_FS 1450 #define PROTO_INUSE_NR 64 /* should be enough for the first time */ 1451 struct prot_inuse { 1452 int all; 1453 int val[PROTO_INUSE_NR]; 1454 }; 1455 1456 static inline void sock_prot_inuse_add(const struct net *net, 1457 const struct proto *prot, int val) 1458 { 1459 this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val); 1460 } 1461 1462 static inline void sock_inuse_add(const struct net *net, int val) 1463 { 1464 this_cpu_add(net->core.prot_inuse->all, val); 1465 } 1466 1467 int sock_prot_inuse_get(struct net *net, struct proto *proto); 1468 int sock_inuse_get(struct net *net); 1469 #else 1470 static inline void sock_prot_inuse_add(const struct net *net, 1471 const struct proto *prot, int val) 1472 { 1473 } 1474 1475 static inline void sock_inuse_add(const struct net *net, int val) 1476 { 1477 } 1478 #endif 1479 1480 1481 /* With per-bucket locks this operation is not-atomic, so that 1482 * this version is not worse. 1483 */ 1484 static inline int __sk_prot_rehash(struct sock *sk) 1485 { 1486 sk->sk_prot->unhash(sk); 1487 return sk->sk_prot->hash(sk); 1488 } 1489 1490 /* About 10 seconds */ 1491 #define SOCK_DESTROY_TIME (10*HZ) 1492 1493 /* Sockets 0-1023 can't be bound to unless you are superuser */ 1494 #define PROT_SOCK 1024 1495 1496 #define SHUTDOWN_MASK 3 1497 #define RCV_SHUTDOWN 1 1498 #define SEND_SHUTDOWN 2 1499 1500 #define SOCK_BINDADDR_LOCK 4 1501 #define SOCK_BINDPORT_LOCK 8 1502 1503 struct socket_alloc { 1504 struct socket socket; 1505 struct inode vfs_inode; 1506 }; 1507 1508 static inline struct socket *SOCKET_I(struct inode *inode) 1509 { 1510 return &container_of(inode, struct socket_alloc, vfs_inode)->socket; 1511 } 1512 1513 static inline struct inode *SOCK_INODE(struct socket *socket) 1514 { 1515 return &container_of(socket, struct socket_alloc, socket)->vfs_inode; 1516 } 1517 1518 /* 1519 * Functions for memory accounting 1520 */ 1521 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind); 1522 int __sk_mem_schedule(struct sock *sk, int size, int kind); 1523 void __sk_mem_reduce_allocated(struct sock *sk, int amount); 1524 void __sk_mem_reclaim(struct sock *sk, int amount); 1525 1526 /* We used to have PAGE_SIZE here, but systems with 64KB pages 1527 * do not necessarily have 16x time more memory than 4KB ones. 1528 */ 1529 #define SK_MEM_QUANTUM 4096 1530 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) 1531 #define SK_MEM_SEND 0 1532 #define SK_MEM_RECV 1 1533 1534 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */ 1535 static inline long sk_prot_mem_limits(const struct sock *sk, int index) 1536 { 1537 long val = sk->sk_prot->sysctl_mem[index]; 1538 1539 #if PAGE_SIZE > SK_MEM_QUANTUM 1540 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT; 1541 #elif PAGE_SIZE < SK_MEM_QUANTUM 1542 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT; 1543 #endif 1544 return val; 1545 } 1546 1547 static inline int sk_mem_pages(int amt) 1548 { 1549 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; 1550 } 1551 1552 static inline bool sk_has_account(struct sock *sk) 1553 { 1554 /* return true if protocol supports memory accounting */ 1555 return !!sk->sk_prot->memory_allocated; 1556 } 1557 1558 static inline bool sk_wmem_schedule(struct sock *sk, int size) 1559 { 1560 if (!sk_has_account(sk)) 1561 return true; 1562 return size <= sk->sk_forward_alloc || 1563 __sk_mem_schedule(sk, size, SK_MEM_SEND); 1564 } 1565 1566 static inline bool 1567 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 1568 { 1569 if (!sk_has_account(sk)) 1570 return true; 1571 return size <= sk->sk_forward_alloc || 1572 __sk_mem_schedule(sk, size, SK_MEM_RECV) || 1573 skb_pfmemalloc(skb); 1574 } 1575 1576 static inline int sk_unused_reserved_mem(const struct sock *sk) 1577 { 1578 int unused_mem; 1579 1580 if (likely(!sk->sk_reserved_mem)) 1581 return 0; 1582 1583 unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued - 1584 atomic_read(&sk->sk_rmem_alloc); 1585 1586 return unused_mem > 0 ? unused_mem : 0; 1587 } 1588 1589 static inline void sk_mem_reclaim(struct sock *sk) 1590 { 1591 int reclaimable; 1592 1593 if (!sk_has_account(sk)) 1594 return; 1595 1596 reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk); 1597 1598 if (reclaimable >= SK_MEM_QUANTUM) 1599 __sk_mem_reclaim(sk, reclaimable); 1600 } 1601 1602 static inline void sk_mem_reclaim_final(struct sock *sk) 1603 { 1604 sk->sk_reserved_mem = 0; 1605 sk_mem_reclaim(sk); 1606 } 1607 1608 static inline void sk_mem_reclaim_partial(struct sock *sk) 1609 { 1610 int reclaimable; 1611 1612 if (!sk_has_account(sk)) 1613 return; 1614 1615 reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk); 1616 1617 if (reclaimable > SK_MEM_QUANTUM) 1618 __sk_mem_reclaim(sk, reclaimable - 1); 1619 } 1620 1621 static inline void sk_mem_charge(struct sock *sk, int size) 1622 { 1623 if (!sk_has_account(sk)) 1624 return; 1625 sk->sk_forward_alloc -= size; 1626 } 1627 1628 /* the following macros control memory reclaiming in sk_mem_uncharge() 1629 */ 1630 #define SK_RECLAIM_THRESHOLD (1 << 21) 1631 #define SK_RECLAIM_CHUNK (1 << 20) 1632 1633 static inline void sk_mem_uncharge(struct sock *sk, int size) 1634 { 1635 int reclaimable; 1636 1637 if (!sk_has_account(sk)) 1638 return; 1639 sk->sk_forward_alloc += size; 1640 reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk); 1641 1642 /* Avoid a possible overflow. 1643 * TCP send queues can make this happen, if sk_mem_reclaim() 1644 * is not called and more than 2 GBytes are released at once. 1645 * 1646 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is 1647 * no need to hold that much forward allocation anyway. 1648 */ 1649 if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD)) 1650 __sk_mem_reclaim(sk, SK_RECLAIM_CHUNK); 1651 } 1652 1653 /* 1654 * Macro so as to not evaluate some arguments when 1655 * lockdep is not enabled. 1656 * 1657 * Mark both the sk_lock and the sk_lock.slock as a 1658 * per-address-family lock class. 1659 */ 1660 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \ 1661 do { \ 1662 sk->sk_lock.owned = 0; \ 1663 init_waitqueue_head(&sk->sk_lock.wq); \ 1664 spin_lock_init(&(sk)->sk_lock.slock); \ 1665 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \ 1666 sizeof((sk)->sk_lock)); \ 1667 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \ 1668 (skey), (sname)); \ 1669 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \ 1670 } while (0) 1671 1672 static inline bool lockdep_sock_is_held(const struct sock *sk) 1673 { 1674 return lockdep_is_held(&sk->sk_lock) || 1675 lockdep_is_held(&sk->sk_lock.slock); 1676 } 1677 1678 void lock_sock_nested(struct sock *sk, int subclass); 1679 1680 static inline void lock_sock(struct sock *sk) 1681 { 1682 lock_sock_nested(sk, 0); 1683 } 1684 1685 void __lock_sock(struct sock *sk); 1686 void __release_sock(struct sock *sk); 1687 void release_sock(struct sock *sk); 1688 1689 /* BH context may only use the following locking interface. */ 1690 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock)) 1691 #define bh_lock_sock_nested(__sk) \ 1692 spin_lock_nested(&((__sk)->sk_lock.slock), \ 1693 SINGLE_DEPTH_NESTING) 1694 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock)) 1695 1696 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock); 1697 1698 /** 1699 * lock_sock_fast - fast version of lock_sock 1700 * @sk: socket 1701 * 1702 * This version should be used for very small section, where process wont block 1703 * return false if fast path is taken: 1704 * 1705 * sk_lock.slock locked, owned = 0, BH disabled 1706 * 1707 * return true if slow path is taken: 1708 * 1709 * sk_lock.slock unlocked, owned = 1, BH enabled 1710 */ 1711 static inline bool lock_sock_fast(struct sock *sk) 1712 { 1713 /* The sk_lock has mutex_lock() semantics here. */ 1714 mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_); 1715 1716 return __lock_sock_fast(sk); 1717 } 1718 1719 /* fast socket lock variant for caller already holding a [different] socket lock */ 1720 static inline bool lock_sock_fast_nested(struct sock *sk) 1721 { 1722 mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_); 1723 1724 return __lock_sock_fast(sk); 1725 } 1726 1727 /** 1728 * unlock_sock_fast - complement of lock_sock_fast 1729 * @sk: socket 1730 * @slow: slow mode 1731 * 1732 * fast unlock socket for user context. 1733 * If slow mode is on, we call regular release_sock() 1734 */ 1735 static inline void unlock_sock_fast(struct sock *sk, bool slow) 1736 __releases(&sk->sk_lock.slock) 1737 { 1738 if (slow) { 1739 release_sock(sk); 1740 __release(&sk->sk_lock.slock); 1741 } else { 1742 mutex_release(&sk->sk_lock.dep_map, _RET_IP_); 1743 spin_unlock_bh(&sk->sk_lock.slock); 1744 } 1745 } 1746 1747 /* Used by processes to "lock" a socket state, so that 1748 * interrupts and bottom half handlers won't change it 1749 * from under us. It essentially blocks any incoming 1750 * packets, so that we won't get any new data or any 1751 * packets that change the state of the socket. 1752 * 1753 * While locked, BH processing will add new packets to 1754 * the backlog queue. This queue is processed by the 1755 * owner of the socket lock right before it is released. 1756 * 1757 * Since ~2.3.5 it is also exclusive sleep lock serializing 1758 * accesses from user process context. 1759 */ 1760 1761 static inline void sock_owned_by_me(const struct sock *sk) 1762 { 1763 #ifdef CONFIG_LOCKDEP 1764 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks); 1765 #endif 1766 } 1767 1768 static inline bool sock_owned_by_user(const struct sock *sk) 1769 { 1770 sock_owned_by_me(sk); 1771 return sk->sk_lock.owned; 1772 } 1773 1774 static inline bool sock_owned_by_user_nocheck(const struct sock *sk) 1775 { 1776 return sk->sk_lock.owned; 1777 } 1778 1779 static inline void sock_release_ownership(struct sock *sk) 1780 { 1781 if (sock_owned_by_user_nocheck(sk)) { 1782 sk->sk_lock.owned = 0; 1783 1784 /* The sk_lock has mutex_unlock() semantics: */ 1785 mutex_release(&sk->sk_lock.dep_map, _RET_IP_); 1786 } 1787 } 1788 1789 /* no reclassification while locks are held */ 1790 static inline bool sock_allow_reclassification(const struct sock *csk) 1791 { 1792 struct sock *sk = (struct sock *)csk; 1793 1794 return !sock_owned_by_user_nocheck(sk) && 1795 !spin_is_locked(&sk->sk_lock.slock); 1796 } 1797 1798 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, 1799 struct proto *prot, int kern); 1800 void sk_free(struct sock *sk); 1801 void sk_destruct(struct sock *sk); 1802 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); 1803 void sk_free_unlock_clone(struct sock *sk); 1804 1805 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, 1806 gfp_t priority); 1807 void __sock_wfree(struct sk_buff *skb); 1808 void sock_wfree(struct sk_buff *skb); 1809 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size, 1810 gfp_t priority); 1811 void skb_orphan_partial(struct sk_buff *skb); 1812 void sock_rfree(struct sk_buff *skb); 1813 void sock_efree(struct sk_buff *skb); 1814 #ifdef CONFIG_INET 1815 void sock_edemux(struct sk_buff *skb); 1816 void sock_pfree(struct sk_buff *skb); 1817 #else 1818 #define sock_edemux sock_efree 1819 #endif 1820 1821 int sock_setsockopt(struct socket *sock, int level, int op, 1822 sockptr_t optval, unsigned int optlen); 1823 1824 int sock_getsockopt(struct socket *sock, int level, int op, 1825 char __user *optval, int __user *optlen); 1826 int sock_gettstamp(struct socket *sock, void __user *userstamp, 1827 bool timeval, bool time32); 1828 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, 1829 int noblock, int *errcode); 1830 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, 1831 unsigned long data_len, int noblock, 1832 int *errcode, int max_page_order); 1833 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); 1834 void sock_kfree_s(struct sock *sk, void *mem, int size); 1835 void sock_kzfree_s(struct sock *sk, void *mem, int size); 1836 void sk_send_sigurg(struct sock *sk); 1837 1838 struct sockcm_cookie { 1839 u64 transmit_time; 1840 u32 mark; 1841 u16 tsflags; 1842 }; 1843 1844 static inline void sockcm_init(struct sockcm_cookie *sockc, 1845 const struct sock *sk) 1846 { 1847 *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags }; 1848 } 1849 1850 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg, 1851 struct sockcm_cookie *sockc); 1852 int sock_cmsg_send(struct sock *sk, struct msghdr *msg, 1853 struct sockcm_cookie *sockc); 1854 1855 /* 1856 * Functions to fill in entries in struct proto_ops when a protocol 1857 * does not implement a particular function. 1858 */ 1859 int sock_no_bind(struct socket *, struct sockaddr *, int); 1860 int sock_no_connect(struct socket *, struct sockaddr *, int, int); 1861 int sock_no_socketpair(struct socket *, struct socket *); 1862 int sock_no_accept(struct socket *, struct socket *, int, bool); 1863 int sock_no_getname(struct socket *, struct sockaddr *, int); 1864 int sock_no_ioctl(struct socket *, unsigned int, unsigned long); 1865 int sock_no_listen(struct socket *, int); 1866 int sock_no_shutdown(struct socket *, int); 1867 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t); 1868 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len); 1869 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int); 1870 int sock_no_mmap(struct file *file, struct socket *sock, 1871 struct vm_area_struct *vma); 1872 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, 1873 size_t size, int flags); 1874 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page, 1875 int offset, size_t size, int flags); 1876 1877 /* 1878 * Functions to fill in entries in struct proto_ops when a protocol 1879 * uses the inet style. 1880 */ 1881 int sock_common_getsockopt(struct socket *sock, int level, int optname, 1882 char __user *optval, int __user *optlen); 1883 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, 1884 int flags); 1885 int sock_common_setsockopt(struct socket *sock, int level, int optname, 1886 sockptr_t optval, unsigned int optlen); 1887 1888 void sk_common_release(struct sock *sk); 1889 1890 /* 1891 * Default socket callbacks and setup code 1892 */ 1893 1894 /* Initialise core socket variables */ 1895 void sock_init_data(struct socket *sock, struct sock *sk); 1896 1897 /* 1898 * Socket reference counting postulates. 1899 * 1900 * * Each user of socket SHOULD hold a reference count. 1901 * * Each access point to socket (an hash table bucket, reference from a list, 1902 * running timer, skb in flight MUST hold a reference count. 1903 * * When reference count hits 0, it means it will never increase back. 1904 * * When reference count hits 0, it means that no references from 1905 * outside exist to this socket and current process on current CPU 1906 * is last user and may/should destroy this socket. 1907 * * sk_free is called from any context: process, BH, IRQ. When 1908 * it is called, socket has no references from outside -> sk_free 1909 * may release descendant resources allocated by the socket, but 1910 * to the time when it is called, socket is NOT referenced by any 1911 * hash tables, lists etc. 1912 * * Packets, delivered from outside (from network or from another process) 1913 * and enqueued on receive/error queues SHOULD NOT grab reference count, 1914 * when they sit in queue. Otherwise, packets will leak to hole, when 1915 * socket is looked up by one cpu and unhasing is made by another CPU. 1916 * It is true for udp/raw, netlink (leak to receive and error queues), tcp 1917 * (leak to backlog). Packet socket does all the processing inside 1918 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets 1919 * use separate SMP lock, so that they are prone too. 1920 */ 1921 1922 /* Ungrab socket and destroy it, if it was the last reference. */ 1923 static inline void sock_put(struct sock *sk) 1924 { 1925 if (refcount_dec_and_test(&sk->sk_refcnt)) 1926 sk_free(sk); 1927 } 1928 /* Generic version of sock_put(), dealing with all sockets 1929 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...) 1930 */ 1931 void sock_gen_put(struct sock *sk); 1932 1933 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested, 1934 unsigned int trim_cap, bool refcounted); 1935 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb, 1936 const int nested) 1937 { 1938 return __sk_receive_skb(sk, skb, nested, 1, true); 1939 } 1940 1941 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) 1942 { 1943 /* sk_tx_queue_mapping accept only upto a 16-bit value */ 1944 if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX)) 1945 return; 1946 sk->sk_tx_queue_mapping = tx_queue; 1947 } 1948 1949 #define NO_QUEUE_MAPPING USHRT_MAX 1950 1951 static inline void sk_tx_queue_clear(struct sock *sk) 1952 { 1953 sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING; 1954 } 1955 1956 static inline int sk_tx_queue_get(const struct sock *sk) 1957 { 1958 if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING) 1959 return sk->sk_tx_queue_mapping; 1960 1961 return -1; 1962 } 1963 1964 static inline void __sk_rx_queue_set(struct sock *sk, 1965 const struct sk_buff *skb, 1966 bool force_set) 1967 { 1968 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 1969 if (skb_rx_queue_recorded(skb)) { 1970 u16 rx_queue = skb_get_rx_queue(skb); 1971 1972 if (force_set || 1973 unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue)) 1974 WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue); 1975 } 1976 #endif 1977 } 1978 1979 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb) 1980 { 1981 __sk_rx_queue_set(sk, skb, true); 1982 } 1983 1984 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb) 1985 { 1986 __sk_rx_queue_set(sk, skb, false); 1987 } 1988 1989 static inline void sk_rx_queue_clear(struct sock *sk) 1990 { 1991 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 1992 WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING); 1993 #endif 1994 } 1995 1996 static inline int sk_rx_queue_get(const struct sock *sk) 1997 { 1998 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 1999 if (sk) { 2000 int res = READ_ONCE(sk->sk_rx_queue_mapping); 2001 2002 if (res != NO_QUEUE_MAPPING) 2003 return res; 2004 } 2005 #endif 2006 2007 return -1; 2008 } 2009 2010 static inline void sk_set_socket(struct sock *sk, struct socket *sock) 2011 { 2012 sk->sk_socket = sock; 2013 } 2014 2015 static inline wait_queue_head_t *sk_sleep(struct sock *sk) 2016 { 2017 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0); 2018 return &rcu_dereference_raw(sk->sk_wq)->wait; 2019 } 2020 /* Detach socket from process context. 2021 * Announce socket dead, detach it from wait queue and inode. 2022 * Note that parent inode held reference count on this struct sock, 2023 * we do not release it in this function, because protocol 2024 * probably wants some additional cleanups or even continuing 2025 * to work with this socket (TCP). 2026 */ 2027 static inline void sock_orphan(struct sock *sk) 2028 { 2029 write_lock_bh(&sk->sk_callback_lock); 2030 sock_set_flag(sk, SOCK_DEAD); 2031 sk_set_socket(sk, NULL); 2032 sk->sk_wq = NULL; 2033 write_unlock_bh(&sk->sk_callback_lock); 2034 } 2035 2036 static inline void sock_graft(struct sock *sk, struct socket *parent) 2037 { 2038 WARN_ON(parent->sk); 2039 write_lock_bh(&sk->sk_callback_lock); 2040 rcu_assign_pointer(sk->sk_wq, &parent->wq); 2041 parent->sk = sk; 2042 sk_set_socket(sk, parent); 2043 sk->sk_uid = SOCK_INODE(parent)->i_uid; 2044 security_sock_graft(sk, parent); 2045 write_unlock_bh(&sk->sk_callback_lock); 2046 } 2047 2048 kuid_t sock_i_uid(struct sock *sk); 2049 unsigned long sock_i_ino(struct sock *sk); 2050 2051 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk) 2052 { 2053 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0); 2054 } 2055 2056 static inline u32 net_tx_rndhash(void) 2057 { 2058 u32 v = prandom_u32(); 2059 2060 return v ?: 1; 2061 } 2062 2063 static inline void sk_set_txhash(struct sock *sk) 2064 { 2065 /* This pairs with READ_ONCE() in skb_set_hash_from_sk() */ 2066 WRITE_ONCE(sk->sk_txhash, net_tx_rndhash()); 2067 } 2068 2069 static inline bool sk_rethink_txhash(struct sock *sk) 2070 { 2071 if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) { 2072 sk_set_txhash(sk); 2073 return true; 2074 } 2075 return false; 2076 } 2077 2078 static inline struct dst_entry * 2079 __sk_dst_get(struct sock *sk) 2080 { 2081 return rcu_dereference_check(sk->sk_dst_cache, 2082 lockdep_sock_is_held(sk)); 2083 } 2084 2085 static inline struct dst_entry * 2086 sk_dst_get(struct sock *sk) 2087 { 2088 struct dst_entry *dst; 2089 2090 rcu_read_lock(); 2091 dst = rcu_dereference(sk->sk_dst_cache); 2092 if (dst && !atomic_inc_not_zero(&dst->__refcnt)) 2093 dst = NULL; 2094 rcu_read_unlock(); 2095 return dst; 2096 } 2097 2098 static inline void __dst_negative_advice(struct sock *sk) 2099 { 2100 struct dst_entry *ndst, *dst = __sk_dst_get(sk); 2101 2102 if (dst && dst->ops->negative_advice) { 2103 ndst = dst->ops->negative_advice(dst); 2104 2105 if (ndst != dst) { 2106 rcu_assign_pointer(sk->sk_dst_cache, ndst); 2107 sk_tx_queue_clear(sk); 2108 sk->sk_dst_pending_confirm = 0; 2109 } 2110 } 2111 } 2112 2113 static inline void dst_negative_advice(struct sock *sk) 2114 { 2115 sk_rethink_txhash(sk); 2116 __dst_negative_advice(sk); 2117 } 2118 2119 static inline void 2120 __sk_dst_set(struct sock *sk, struct dst_entry *dst) 2121 { 2122 struct dst_entry *old_dst; 2123 2124 sk_tx_queue_clear(sk); 2125 sk->sk_dst_pending_confirm = 0; 2126 old_dst = rcu_dereference_protected(sk->sk_dst_cache, 2127 lockdep_sock_is_held(sk)); 2128 rcu_assign_pointer(sk->sk_dst_cache, dst); 2129 dst_release(old_dst); 2130 } 2131 2132 static inline void 2133 sk_dst_set(struct sock *sk, struct dst_entry *dst) 2134 { 2135 struct dst_entry *old_dst; 2136 2137 sk_tx_queue_clear(sk); 2138 sk->sk_dst_pending_confirm = 0; 2139 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); 2140 dst_release(old_dst); 2141 } 2142 2143 static inline void 2144 __sk_dst_reset(struct sock *sk) 2145 { 2146 __sk_dst_set(sk, NULL); 2147 } 2148 2149 static inline void 2150 sk_dst_reset(struct sock *sk) 2151 { 2152 sk_dst_set(sk, NULL); 2153 } 2154 2155 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); 2156 2157 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); 2158 2159 static inline void sk_dst_confirm(struct sock *sk) 2160 { 2161 if (!READ_ONCE(sk->sk_dst_pending_confirm)) 2162 WRITE_ONCE(sk->sk_dst_pending_confirm, 1); 2163 } 2164 2165 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n) 2166 { 2167 if (skb_get_dst_pending_confirm(skb)) { 2168 struct sock *sk = skb->sk; 2169 2170 if (sk && READ_ONCE(sk->sk_dst_pending_confirm)) 2171 WRITE_ONCE(sk->sk_dst_pending_confirm, 0); 2172 neigh_confirm(n); 2173 } 2174 } 2175 2176 bool sk_mc_loop(struct sock *sk); 2177 2178 static inline bool sk_can_gso(const struct sock *sk) 2179 { 2180 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); 2181 } 2182 2183 void sk_setup_caps(struct sock *sk, struct dst_entry *dst); 2184 2185 static inline void sk_gso_disable(struct sock *sk) 2186 { 2187 sk->sk_gso_disabled = 1; 2188 sk->sk_route_caps &= ~NETIF_F_GSO_MASK; 2189 } 2190 2191 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb, 2192 struct iov_iter *from, char *to, 2193 int copy, int offset) 2194 { 2195 if (skb->ip_summed == CHECKSUM_NONE) { 2196 __wsum csum = 0; 2197 if (!csum_and_copy_from_iter_full(to, copy, &csum, from)) 2198 return -EFAULT; 2199 skb->csum = csum_block_add(skb->csum, csum, offset); 2200 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { 2201 if (!copy_from_iter_full_nocache(to, copy, from)) 2202 return -EFAULT; 2203 } else if (!copy_from_iter_full(to, copy, from)) 2204 return -EFAULT; 2205 2206 return 0; 2207 } 2208 2209 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, 2210 struct iov_iter *from, int copy) 2211 { 2212 int err, offset = skb->len; 2213 2214 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), 2215 copy, offset); 2216 if (err) 2217 __skb_trim(skb, offset); 2218 2219 return err; 2220 } 2221 2222 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from, 2223 struct sk_buff *skb, 2224 struct page *page, 2225 int off, int copy) 2226 { 2227 int err; 2228 2229 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off, 2230 copy, skb->len); 2231 if (err) 2232 return err; 2233 2234 skb->len += copy; 2235 skb->data_len += copy; 2236 skb->truesize += copy; 2237 sk_wmem_queued_add(sk, copy); 2238 sk_mem_charge(sk, copy); 2239 return 0; 2240 } 2241 2242 /** 2243 * sk_wmem_alloc_get - returns write allocations 2244 * @sk: socket 2245 * 2246 * Return: sk_wmem_alloc minus initial offset of one 2247 */ 2248 static inline int sk_wmem_alloc_get(const struct sock *sk) 2249 { 2250 return refcount_read(&sk->sk_wmem_alloc) - 1; 2251 } 2252 2253 /** 2254 * sk_rmem_alloc_get - returns read allocations 2255 * @sk: socket 2256 * 2257 * Return: sk_rmem_alloc 2258 */ 2259 static inline int sk_rmem_alloc_get(const struct sock *sk) 2260 { 2261 return atomic_read(&sk->sk_rmem_alloc); 2262 } 2263 2264 /** 2265 * sk_has_allocations - check if allocations are outstanding 2266 * @sk: socket 2267 * 2268 * Return: true if socket has write or read allocations 2269 */ 2270 static inline bool sk_has_allocations(const struct sock *sk) 2271 { 2272 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); 2273 } 2274 2275 /** 2276 * skwq_has_sleeper - check if there are any waiting processes 2277 * @wq: struct socket_wq 2278 * 2279 * Return: true if socket_wq has waiting processes 2280 * 2281 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory 2282 * barrier call. They were added due to the race found within the tcp code. 2283 * 2284 * Consider following tcp code paths:: 2285 * 2286 * CPU1 CPU2 2287 * sys_select receive packet 2288 * ... ... 2289 * __add_wait_queue update tp->rcv_nxt 2290 * ... ... 2291 * tp->rcv_nxt check sock_def_readable 2292 * ... { 2293 * schedule rcu_read_lock(); 2294 * wq = rcu_dereference(sk->sk_wq); 2295 * if (wq && waitqueue_active(&wq->wait)) 2296 * wake_up_interruptible(&wq->wait) 2297 * ... 2298 * } 2299 * 2300 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay 2301 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 2302 * could then endup calling schedule and sleep forever if there are no more 2303 * data on the socket. 2304 * 2305 */ 2306 static inline bool skwq_has_sleeper(struct socket_wq *wq) 2307 { 2308 return wq && wq_has_sleeper(&wq->wait); 2309 } 2310 2311 /** 2312 * sock_poll_wait - place memory barrier behind the poll_wait call. 2313 * @filp: file 2314 * @sock: socket to wait on 2315 * @p: poll_table 2316 * 2317 * See the comments in the wq_has_sleeper function. 2318 */ 2319 static inline void sock_poll_wait(struct file *filp, struct socket *sock, 2320 poll_table *p) 2321 { 2322 if (!poll_does_not_wait(p)) { 2323 poll_wait(filp, &sock->wq.wait, p); 2324 /* We need to be sure we are in sync with the 2325 * socket flags modification. 2326 * 2327 * This memory barrier is paired in the wq_has_sleeper. 2328 */ 2329 smp_mb(); 2330 } 2331 } 2332 2333 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk) 2334 { 2335 /* This pairs with WRITE_ONCE() in sk_set_txhash() */ 2336 u32 txhash = READ_ONCE(sk->sk_txhash); 2337 2338 if (txhash) { 2339 skb->l4_hash = 1; 2340 skb->hash = txhash; 2341 } 2342 } 2343 2344 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk); 2345 2346 /* 2347 * Queue a received datagram if it will fit. Stream and sequenced 2348 * protocols can't normally use this as they need to fit buffers in 2349 * and play with them. 2350 * 2351 * Inlined as it's very short and called for pretty much every 2352 * packet ever received. 2353 */ 2354 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 2355 { 2356 skb_orphan(skb); 2357 skb->sk = sk; 2358 skb->destructor = sock_rfree; 2359 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 2360 sk_mem_charge(sk, skb->truesize); 2361 } 2362 2363 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk) 2364 { 2365 if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) { 2366 skb_orphan(skb); 2367 skb->destructor = sock_efree; 2368 skb->sk = sk; 2369 return true; 2370 } 2371 return false; 2372 } 2373 2374 static inline void skb_prepare_for_gro(struct sk_buff *skb) 2375 { 2376 if (skb->destructor != sock_wfree) { 2377 skb_orphan(skb); 2378 return; 2379 } 2380 skb->slow_gro = 1; 2381 } 2382 2383 void sk_reset_timer(struct sock *sk, struct timer_list *timer, 2384 unsigned long expires); 2385 2386 void sk_stop_timer(struct sock *sk, struct timer_list *timer); 2387 2388 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer); 2389 2390 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue, 2391 struct sk_buff *skb, unsigned int flags, 2392 void (*destructor)(struct sock *sk, 2393 struct sk_buff *skb)); 2394 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2395 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 2396 2397 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); 2398 struct sk_buff *sock_dequeue_err_skb(struct sock *sk); 2399 2400 /* 2401 * Recover an error report and clear atomically 2402 */ 2403 2404 static inline int sock_error(struct sock *sk) 2405 { 2406 int err; 2407 2408 /* Avoid an atomic operation for the common case. 2409 * This is racy since another cpu/thread can change sk_err under us. 2410 */ 2411 if (likely(data_race(!sk->sk_err))) 2412 return 0; 2413 2414 err = xchg(&sk->sk_err, 0); 2415 return -err; 2416 } 2417 2418 void sk_error_report(struct sock *sk); 2419 2420 static inline unsigned long sock_wspace(struct sock *sk) 2421 { 2422 int amt = 0; 2423 2424 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 2425 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc); 2426 if (amt < 0) 2427 amt = 0; 2428 } 2429 return amt; 2430 } 2431 2432 /* Note: 2433 * We use sk->sk_wq_raw, from contexts knowing this 2434 * pointer is not NULL and cannot disappear/change. 2435 */ 2436 static inline void sk_set_bit(int nr, struct sock *sk) 2437 { 2438 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2439 !sock_flag(sk, SOCK_FASYNC)) 2440 return; 2441 2442 set_bit(nr, &sk->sk_wq_raw->flags); 2443 } 2444 2445 static inline void sk_clear_bit(int nr, struct sock *sk) 2446 { 2447 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) && 2448 !sock_flag(sk, SOCK_FASYNC)) 2449 return; 2450 2451 clear_bit(nr, &sk->sk_wq_raw->flags); 2452 } 2453 2454 static inline void sk_wake_async(const struct sock *sk, int how, int band) 2455 { 2456 if (sock_flag(sk, SOCK_FASYNC)) { 2457 rcu_read_lock(); 2458 sock_wake_async(rcu_dereference(sk->sk_wq), how, band); 2459 rcu_read_unlock(); 2460 } 2461 } 2462 2463 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might 2464 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak. 2465 * Note: for send buffers, TCP works better if we can build two skbs at 2466 * minimum. 2467 */ 2468 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff))) 2469 2470 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2) 2471 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE 2472 2473 static inline void sk_stream_moderate_sndbuf(struct sock *sk) 2474 { 2475 u32 val; 2476 2477 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) 2478 return; 2479 2480 val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); 2481 val = max_t(u32, val, sk_unused_reserved_mem(sk)); 2482 2483 WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF)); 2484 } 2485 2486 /** 2487 * sk_page_frag - return an appropriate page_frag 2488 * @sk: socket 2489 * 2490 * Use the per task page_frag instead of the per socket one for 2491 * optimization when we know that we're in process context and own 2492 * everything that's associated with %current. 2493 * 2494 * Both direct reclaim and page faults can nest inside other 2495 * socket operations and end up recursing into sk_page_frag() 2496 * while it's already in use: explicitly avoid task page_frag 2497 * usage if the caller is potentially doing any of them. 2498 * This assumes that page fault handlers use the GFP_NOFS flags. 2499 * 2500 * Return: a per task page_frag if context allows that, 2501 * otherwise a per socket one. 2502 */ 2503 static inline struct page_frag *sk_page_frag(struct sock *sk) 2504 { 2505 if ((sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC | __GFP_FS)) == 2506 (__GFP_DIRECT_RECLAIM | __GFP_FS)) 2507 return ¤t->task_frag; 2508 2509 return &sk->sk_frag; 2510 } 2511 2512 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag); 2513 2514 /* 2515 * Default write policy as shown to user space via poll/select/SIGIO 2516 */ 2517 static inline bool sock_writeable(const struct sock *sk) 2518 { 2519 return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1); 2520 } 2521 2522 static inline gfp_t gfp_any(void) 2523 { 2524 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; 2525 } 2526 2527 static inline gfp_t gfp_memcg_charge(void) 2528 { 2529 return in_softirq() ? GFP_NOWAIT : GFP_KERNEL; 2530 } 2531 2532 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock) 2533 { 2534 return noblock ? 0 : sk->sk_rcvtimeo; 2535 } 2536 2537 static inline long sock_sndtimeo(const struct sock *sk, bool noblock) 2538 { 2539 return noblock ? 0 : sk->sk_sndtimeo; 2540 } 2541 2542 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len) 2543 { 2544 int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len); 2545 2546 return v ?: 1; 2547 } 2548 2549 /* Alas, with timeout socket operations are not restartable. 2550 * Compare this to poll(). 2551 */ 2552 static inline int sock_intr_errno(long timeo) 2553 { 2554 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR; 2555 } 2556 2557 struct sock_skb_cb { 2558 u32 dropcount; 2559 }; 2560 2561 /* Store sock_skb_cb at the end of skb->cb[] so protocol families 2562 * using skb->cb[] would keep using it directly and utilize its 2563 * alignement guarantee. 2564 */ 2565 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \ 2566 sizeof(struct sock_skb_cb))) 2567 2568 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \ 2569 SOCK_SKB_CB_OFFSET)) 2570 2571 #define sock_skb_cb_check_size(size) \ 2572 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET) 2573 2574 static inline void 2575 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) 2576 { 2577 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ? 2578 atomic_read(&sk->sk_drops) : 0; 2579 } 2580 2581 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) 2582 { 2583 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2584 2585 atomic_add(segs, &sk->sk_drops); 2586 } 2587 2588 static inline ktime_t sock_read_timestamp(struct sock *sk) 2589 { 2590 #if BITS_PER_LONG==32 2591 unsigned int seq; 2592 ktime_t kt; 2593 2594 do { 2595 seq = read_seqbegin(&sk->sk_stamp_seq); 2596 kt = sk->sk_stamp; 2597 } while (read_seqretry(&sk->sk_stamp_seq, seq)); 2598 2599 return kt; 2600 #else 2601 return READ_ONCE(sk->sk_stamp); 2602 #endif 2603 } 2604 2605 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt) 2606 { 2607 #if BITS_PER_LONG==32 2608 write_seqlock(&sk->sk_stamp_seq); 2609 sk->sk_stamp = kt; 2610 write_sequnlock(&sk->sk_stamp_seq); 2611 #else 2612 WRITE_ONCE(sk->sk_stamp, kt); 2613 #endif 2614 } 2615 2616 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 2617 struct sk_buff *skb); 2618 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 2619 struct sk_buff *skb); 2620 2621 static inline void 2622 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) 2623 { 2624 ktime_t kt = skb->tstamp; 2625 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb); 2626 2627 /* 2628 * generate control messages if 2629 * - receive time stamping in software requested 2630 * - software time stamp available and wanted 2631 * - hardware time stamps available and wanted 2632 */ 2633 if (sock_flag(sk, SOCK_RCVTSTAMP) || 2634 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) || 2635 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) || 2636 (hwtstamps->hwtstamp && 2637 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE))) 2638 __sock_recv_timestamp(msg, sk, skb); 2639 else 2640 sock_write_timestamp(sk, kt); 2641 2642 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid) 2643 __sock_recv_wifi_status(msg, sk, skb); 2644 } 2645 2646 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2647 struct sk_buff *skb); 2648 2649 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC) 2650 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 2651 struct sk_buff *skb) 2652 { 2653 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \ 2654 (1UL << SOCK_RCVTSTAMP)) 2655 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \ 2656 SOF_TIMESTAMPING_RAW_HARDWARE) 2657 2658 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) 2659 __sock_recv_ts_and_drops(msg, sk, skb); 2660 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP))) 2661 sock_write_timestamp(sk, skb->tstamp); 2662 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) 2663 sock_write_timestamp(sk, 0); 2664 } 2665 2666 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); 2667 2668 /** 2669 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped 2670 * @sk: socket sending this packet 2671 * @tsflags: timestamping flags to use 2672 * @tx_flags: completed with instructions for time stamping 2673 * @tskey: filled in with next sk_tskey (not for TCP, which uses seqno) 2674 * 2675 * Note: callers should take care of initial ``*tx_flags`` value (usually 0) 2676 */ 2677 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags, 2678 __u8 *tx_flags, __u32 *tskey) 2679 { 2680 if (unlikely(tsflags)) { 2681 __sock_tx_timestamp(tsflags, tx_flags); 2682 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey && 2683 tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) 2684 *tskey = atomic_inc_return(&sk->sk_tskey) - 1; 2685 } 2686 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) 2687 *tx_flags |= SKBTX_WIFI_STATUS; 2688 } 2689 2690 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags, 2691 __u8 *tx_flags) 2692 { 2693 _sock_tx_timestamp(sk, tsflags, tx_flags, NULL); 2694 } 2695 2696 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags) 2697 { 2698 _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags, 2699 &skb_shinfo(skb)->tskey); 2700 } 2701 2702 static inline bool sk_is_tcp(const struct sock *sk) 2703 { 2704 return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP; 2705 } 2706 2707 /** 2708 * sk_eat_skb - Release a skb if it is no longer needed 2709 * @sk: socket to eat this skb from 2710 * @skb: socket buffer to eat 2711 * 2712 * This routine must be called with interrupts disabled or with the socket 2713 * locked so that the sk_buff queue operation is ok. 2714 */ 2715 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) 2716 { 2717 __skb_unlink(skb, &sk->sk_receive_queue); 2718 __kfree_skb(skb); 2719 } 2720 2721 static inline bool 2722 skb_sk_is_prefetched(struct sk_buff *skb) 2723 { 2724 #ifdef CONFIG_INET 2725 return skb->destructor == sock_pfree; 2726 #else 2727 return false; 2728 #endif /* CONFIG_INET */ 2729 } 2730 2731 /* This helper checks if a socket is a full socket, 2732 * ie _not_ a timewait or request socket. 2733 */ 2734 static inline bool sk_fullsock(const struct sock *sk) 2735 { 2736 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV); 2737 } 2738 2739 static inline bool 2740 sk_is_refcounted(struct sock *sk) 2741 { 2742 /* Only full sockets have sk->sk_flags. */ 2743 return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE); 2744 } 2745 2746 /** 2747 * skb_steal_sock - steal a socket from an sk_buff 2748 * @skb: sk_buff to steal the socket from 2749 * @refcounted: is set to true if the socket is reference-counted 2750 */ 2751 static inline struct sock * 2752 skb_steal_sock(struct sk_buff *skb, bool *refcounted) 2753 { 2754 if (skb->sk) { 2755 struct sock *sk = skb->sk; 2756 2757 *refcounted = true; 2758 if (skb_sk_is_prefetched(skb)) 2759 *refcounted = sk_is_refcounted(sk); 2760 skb->destructor = NULL; 2761 skb->sk = NULL; 2762 return sk; 2763 } 2764 *refcounted = false; 2765 return NULL; 2766 } 2767 2768 /* Checks if this SKB belongs to an HW offloaded socket 2769 * and whether any SW fallbacks are required based on dev. 2770 * Check decrypted mark in case skb_orphan() cleared socket. 2771 */ 2772 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb, 2773 struct net_device *dev) 2774 { 2775 #ifdef CONFIG_SOCK_VALIDATE_XMIT 2776 struct sock *sk = skb->sk; 2777 2778 if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) { 2779 skb = sk->sk_validate_xmit_skb(sk, dev, skb); 2780 #ifdef CONFIG_TLS_DEVICE 2781 } else if (unlikely(skb->decrypted)) { 2782 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n"); 2783 kfree_skb(skb); 2784 skb = NULL; 2785 #endif 2786 } 2787 #endif 2788 2789 return skb; 2790 } 2791 2792 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV 2793 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE) 2794 */ 2795 static inline bool sk_listener(const struct sock *sk) 2796 { 2797 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV); 2798 } 2799 2800 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag); 2801 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, 2802 int type); 2803 2804 bool sk_ns_capable(const struct sock *sk, 2805 struct user_namespace *user_ns, int cap); 2806 bool sk_capable(const struct sock *sk, int cap); 2807 bool sk_net_capable(const struct sock *sk, int cap); 2808 2809 void sk_get_meminfo(const struct sock *sk, u32 *meminfo); 2810 2811 /* Take into consideration the size of the struct sk_buff overhead in the 2812 * determination of these values, since that is non-constant across 2813 * platforms. This makes socket queueing behavior and performance 2814 * not depend upon such differences. 2815 */ 2816 #define _SK_MEM_PACKETS 256 2817 #define _SK_MEM_OVERHEAD SKB_TRUESIZE(256) 2818 #define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2819 #define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS) 2820 2821 extern __u32 sysctl_wmem_max; 2822 extern __u32 sysctl_rmem_max; 2823 2824 extern int sysctl_tstamp_allow_data; 2825 extern int sysctl_optmem_max; 2826 2827 extern __u32 sysctl_wmem_default; 2828 extern __u32 sysctl_rmem_default; 2829 2830 #define SKB_FRAG_PAGE_ORDER get_order(32768) 2831 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key); 2832 2833 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto) 2834 { 2835 /* Does this proto have per netns sysctl_wmem ? */ 2836 if (proto->sysctl_wmem_offset) 2837 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset); 2838 2839 return *proto->sysctl_wmem; 2840 } 2841 2842 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto) 2843 { 2844 /* Does this proto have per netns sysctl_rmem ? */ 2845 if (proto->sysctl_rmem_offset) 2846 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset); 2847 2848 return *proto->sysctl_rmem; 2849 } 2850 2851 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10) 2852 * Some wifi drivers need to tweak it to get more chunks. 2853 * They can use this helper from their ndo_start_xmit() 2854 */ 2855 static inline void sk_pacing_shift_update(struct sock *sk, int val) 2856 { 2857 if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val) 2858 return; 2859 WRITE_ONCE(sk->sk_pacing_shift, val); 2860 } 2861 2862 /* if a socket is bound to a device, check that the given device 2863 * index is either the same or that the socket is bound to an L3 2864 * master device and the given device index is also enslaved to 2865 * that L3 master 2866 */ 2867 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif) 2868 { 2869 int mdif; 2870 2871 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif) 2872 return true; 2873 2874 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif); 2875 if (mdif && mdif == sk->sk_bound_dev_if) 2876 return true; 2877 2878 return false; 2879 } 2880 2881 void sock_def_readable(struct sock *sk); 2882 2883 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk); 2884 void sock_set_timestamp(struct sock *sk, int optname, bool valbool); 2885 int sock_set_timestamping(struct sock *sk, int optname, 2886 struct so_timestamping timestamping); 2887 2888 void sock_enable_timestamps(struct sock *sk); 2889 void sock_no_linger(struct sock *sk); 2890 void sock_set_keepalive(struct sock *sk); 2891 void sock_set_priority(struct sock *sk, u32 priority); 2892 void sock_set_rcvbuf(struct sock *sk, int val); 2893 void sock_set_mark(struct sock *sk, u32 val); 2894 void sock_set_reuseaddr(struct sock *sk); 2895 void sock_set_reuseport(struct sock *sk); 2896 void sock_set_sndtimeo(struct sock *sk, s64 secs); 2897 2898 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len); 2899 2900 int sock_get_timeout(long timeo, void *optval, bool old_timeval); 2901 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv, 2902 sockptr_t optval, int optlen, bool old_timeval); 2903 2904 static inline bool sk_is_readable(struct sock *sk) 2905 { 2906 if (sk->sk_prot->sock_is_readable) 2907 return sk->sk_prot->sock_is_readable(sk); 2908 return false; 2909 } 2910 #endif /* _SOCK_H */ 2911