1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * NET Generic infrastructure for INET connection oriented protocols. 4 * 5 * Definitions for inet_connection_sock 6 * 7 * Authors: Many people, see the TCP sources 8 * 9 * From code originally in TCP 10 */ 11 #ifndef _INET_CONNECTION_SOCK_H 12 #define _INET_CONNECTION_SOCK_H 13 14 #include <linux/compiler.h> 15 #include <linux/string.h> 16 #include <linux/timer.h> 17 #include <linux/poll.h> 18 #include <linux/kernel.h> 19 #include <linux/sockptr.h> 20 21 #include <net/inet_sock.h> 22 #include <net/request_sock.h> 23 24 /* Cancel timers, when they are not required. */ 25 #undef INET_CSK_CLEAR_TIMERS 26 27 struct inet_bind_bucket; 28 struct inet_bind2_bucket; 29 struct tcp_congestion_ops; 30 31 /* 32 * Pointers to address related TCP functions 33 * (i.e. things that depend on the address family) 34 */ 35 struct inet_connection_sock_af_ops { 36 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 37 void (*send_check)(struct sock *sk, struct sk_buff *skb); 38 int (*rebuild_header)(struct sock *sk); 39 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 40 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 41 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb, 42 struct request_sock *req, 43 struct dst_entry *dst, 44 struct request_sock *req_unhash, 45 bool *own_req); 46 u16 net_header_len; 47 int (*setsockopt)(struct sock *sk, int level, int optname, 48 sockptr_t optval, unsigned int optlen); 49 int (*getsockopt)(struct sock *sk, int level, int optname, 50 char __user *optval, int __user *optlen); 51 void (*mtu_reduced)(struct sock *sk); 52 }; 53 54 /** inet_connection_sock - INET connection oriented sock 55 * 56 * @icsk_accept_queue: FIFO of established children 57 * @icsk_bind_hash: Bind node 58 * @icsk_bind2_hash: Bind node in the bhash2 table 59 * @icsk_retransmit_timer: Resend (no ack) 60 * @icsk_rto: Retransmit timeout 61 * @icsk_pmtu_cookie Last pmtu seen by socket 62 * @icsk_ca_ops Pluggable congestion control hook 63 * @icsk_af_ops Operations which are AF_INET{4,6} specific 64 * @icsk_ulp_ops Pluggable ULP control hook 65 * @icsk_ulp_data ULP private data 66 * @icsk_ca_state: Congestion control state 67 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 68 * @icsk_pending: Scheduled timer event 69 * @icsk_backoff: Backoff 70 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 71 * @icsk_probes_out: unanswered 0 window probes 72 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 73 * @icsk_ack: Delayed ACK control data 74 * @icsk_mtup; MTU probing control data 75 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 76 * @icsk_user_timeout: TCP_USER_TIMEOUT value 77 */ 78 struct inet_connection_sock { 79 /* inet_sock has to be the first member! */ 80 struct inet_sock icsk_inet; 81 struct request_sock_queue icsk_accept_queue; 82 struct inet_bind_bucket *icsk_bind_hash; 83 struct inet_bind2_bucket *icsk_bind2_hash; 84 struct timer_list icsk_retransmit_timer; 85 struct timer_list icsk_delack_timer; 86 __u32 icsk_rto; 87 __u32 icsk_rto_min; 88 u32 icsk_rto_max; 89 __u32 icsk_delack_max; 90 __u32 icsk_pmtu_cookie; 91 const struct tcp_congestion_ops *icsk_ca_ops; 92 const struct inet_connection_sock_af_ops *icsk_af_ops; 93 const struct tcp_ulp_ops *icsk_ulp_ops; 94 void __rcu *icsk_ulp_data; 95 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 96 __u8 icsk_ca_state:5, 97 icsk_ca_initialized:1, 98 icsk_ca_setsockopt:1, 99 icsk_ca_dst_locked:1; 100 __u8 icsk_retransmits; 101 __u8 icsk_pending; 102 __u8 icsk_backoff; 103 __u8 icsk_syn_retries; 104 __u8 icsk_probes_out; 105 __u16 icsk_ext_hdr_len; 106 struct { 107 __u8 pending; /* ACK is pending */ 108 __u8 quick; /* Scheduled number of quick acks */ 109 __u8 pingpong; /* The session is interactive */ 110 __u8 retry; /* Number of attempts */ 111 #define ATO_BITS 8 112 __u32 ato:ATO_BITS, /* Predicted tick of soft clock */ 113 lrcv_flowlabel:20, /* last received ipv6 flowlabel */ 114 dst_quick_ack:1, /* cache dst RTAX_QUICKACK */ 115 unused:3; 116 __u32 lrcvtime; /* timestamp of last received data packet */ 117 __u16 last_seg_size; /* Size of last incoming segment */ 118 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 119 } icsk_ack; 120 struct { 121 /* Range of MTUs to search */ 122 int search_high; 123 int search_low; 124 125 /* Information on the current probe. */ 126 u32 probe_size:31, 127 /* Is the MTUP feature enabled for this connection? */ 128 enabled:1; 129 130 u32 probe_timestamp; 131 } icsk_mtup; 132 u32 icsk_probes_tstamp; 133 u32 icsk_user_timeout; 134 135 u64 icsk_ca_priv[104 / sizeof(u64)]; 136 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) 137 }; 138 139 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 140 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 141 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 142 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 143 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 144 145 #define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.sk) 146 147 static inline void *inet_csk_ca(const struct sock *sk) 148 { 149 return (void *)inet_csk(sk)->icsk_ca_priv; 150 } 151 152 struct sock *inet_csk_clone_lock(const struct sock *sk, 153 const struct request_sock *req, 154 const gfp_t priority); 155 156 enum inet_csk_ack_state_t { 157 ICSK_ACK_SCHED = 1, 158 ICSK_ACK_TIMER = 2, 159 ICSK_ACK_PUSHED = 4, 160 ICSK_ACK_PUSHED2 = 8, 161 ICSK_ACK_NOW = 16, /* Send the next ACK immediately (once) */ 162 ICSK_ACK_NOMEM = 32, 163 }; 164 165 void inet_csk_init_xmit_timers(struct sock *sk, 166 void (*retransmit_handler)(struct timer_list *), 167 void (*delack_handler)(struct timer_list *), 168 void (*keepalive_handler)(struct timer_list *)); 169 void inet_csk_clear_xmit_timers(struct sock *sk); 170 void inet_csk_clear_xmit_timers_sync(struct sock *sk); 171 172 static inline void inet_csk_schedule_ack(struct sock *sk) 173 { 174 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 175 } 176 177 static inline int inet_csk_ack_scheduled(const struct sock *sk) 178 { 179 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 180 } 181 182 static inline void inet_csk_delack_init(struct sock *sk) 183 { 184 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 185 } 186 187 static inline unsigned long 188 icsk_timeout(const struct inet_connection_sock *icsk) 189 { 190 return READ_ONCE(icsk->icsk_retransmit_timer.expires); 191 } 192 193 static inline unsigned long 194 icsk_delack_timeout(const struct inet_connection_sock *icsk) 195 { 196 return READ_ONCE(icsk->icsk_delack_timer.expires); 197 } 198 199 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 200 { 201 struct inet_connection_sock *icsk = inet_csk(sk); 202 203 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 204 smp_store_release(&icsk->icsk_pending, 0); 205 #ifdef INET_CSK_CLEAR_TIMERS 206 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 207 #endif 208 } else if (what == ICSK_TIME_DACK) { 209 smp_store_release(&icsk->icsk_ack.pending, 0); 210 icsk->icsk_ack.retry = 0; 211 #ifdef INET_CSK_CLEAR_TIMERS 212 sk_stop_timer(sk, &icsk->icsk_delack_timer); 213 #endif 214 } else { 215 pr_debug("inet_csk BUG: unknown timer value\n"); 216 } 217 } 218 219 /* 220 * Reset the retransmission timer 221 */ 222 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 223 unsigned long when, 224 const unsigned long max_when) 225 { 226 struct inet_connection_sock *icsk = inet_csk(sk); 227 228 if (when > max_when) { 229 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 230 sk, what, when, (void *)_THIS_IP_); 231 when = max_when; 232 } 233 234 when += jiffies; 235 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 236 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 237 smp_store_release(&icsk->icsk_pending, what); 238 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, when); 239 } else if (what == ICSK_TIME_DACK) { 240 smp_store_release(&icsk->icsk_ack.pending, 241 icsk->icsk_ack.pending | ICSK_ACK_TIMER); 242 sk_reset_timer(sk, &icsk->icsk_delack_timer, when); 243 } else { 244 pr_debug("inet_csk BUG: unknown timer value\n"); 245 } 246 } 247 248 static inline unsigned long 249 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 250 unsigned long max_when) 251 { 252 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 253 254 return (unsigned long)min_t(u64, when, max_when); 255 } 256 257 struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg); 258 259 int inet_csk_get_port(struct sock *sk, unsigned short snum); 260 261 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 262 const struct request_sock *req); 263 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 264 struct sock *newsk, 265 const struct request_sock *req); 266 267 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 268 struct request_sock *req, 269 struct sock *child); 270 bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 271 unsigned long timeout); 272 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 273 struct request_sock *req, 274 bool own_req); 275 276 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 277 { 278 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 279 } 280 281 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 282 { 283 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 284 } 285 286 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 287 { 288 return inet_csk_reqsk_queue_len(sk) > READ_ONCE(sk->sk_max_ack_backlog); 289 } 290 291 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 292 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 293 294 static inline unsigned long 295 reqsk_timeout(struct request_sock *req, unsigned long max_timeout) 296 { 297 u64 timeout = (u64)req->timeout << req->num_timeout; 298 299 return (unsigned long)min_t(u64, timeout, max_timeout); 300 } 301 302 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 303 { 304 /* The below has to be done to allow calling inet_csk_destroy_sock */ 305 sock_set_flag(sk, SOCK_DEAD); 306 this_cpu_inc(*sk->sk_prot->orphan_count); 307 } 308 309 void inet_csk_destroy_sock(struct sock *sk); 310 void inet_csk_prepare_forced_close(struct sock *sk); 311 312 /* 313 * LISTEN is a special case for poll.. 314 */ 315 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 316 { 317 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 318 (EPOLLIN | EPOLLRDNORM) : 0; 319 } 320 321 int inet_csk_listen_start(struct sock *sk); 322 void inet_csk_listen_stop(struct sock *sk); 323 324 /* update the fast reuse flag when adding a socket */ 325 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 326 struct sock *sk); 327 328 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 329 330 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 331 { 332 inet_csk(sk)->icsk_ack.pingpong = 333 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 334 } 335 336 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 337 { 338 inet_csk(sk)->icsk_ack.pingpong = 0; 339 } 340 341 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 342 { 343 return inet_csk(sk)->icsk_ack.pingpong >= 344 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 345 } 346 347 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 348 { 349 struct inet_connection_sock *icsk = inet_csk(sk); 350 351 if (icsk->icsk_ack.pingpong < U8_MAX) 352 icsk->icsk_ack.pingpong++; 353 } 354 355 static inline bool inet_csk_has_ulp(const struct sock *sk) 356 { 357 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops; 358 } 359 360 static inline void inet_init_csk_locks(struct sock *sk) 361 { 362 struct inet_connection_sock *icsk = inet_csk(sk); 363 364 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock); 365 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock); 366 } 367 368 #endif /* _INET_CONNECTION_SOCK_H */ 369