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 u16 net_header_len; 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 int (*setsockopt)(struct sock *sk, int level, int optname, 47 sockptr_t optval, unsigned int optlen); 48 int (*getsockopt)(struct sock *sk, int level, int optname, 49 char __user *optval, int __user *optlen); 50 void (*mtu_reduced)(struct sock *sk); 51 }; 52 53 /** inet_connection_sock - INET connection oriented sock 54 * 55 * @icsk_accept_queue: FIFO of established children 56 * @icsk_bind_hash: Bind node 57 * @icsk_bind2_hash: Bind node in the bhash2 table 58 * @icsk_delack_timer: Delayed ACK timer 59 * @icsk_keepalive_timer: Keepalive timer 60 * @mptcp_tout_timer: mptcp timer 61 * @icsk_rto: Retransmit timeout 62 * @icsk_pmtu_cookie Last pmtu seen by socket 63 * @icsk_ca_ops Pluggable congestion control hook 64 * @icsk_af_ops Operations which are AF_INET{4,6} specific 65 * @icsk_ulp_ops Pluggable ULP control hook 66 * @icsk_ulp_data ULP private data 67 * @icsk_ca_state: Congestion control state 68 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 69 * @icsk_pending: Scheduled timer event 70 * @icsk_backoff: Backoff 71 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 72 * @icsk_probes_out: unanswered 0 window probes 73 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 74 * @icsk_ack: Delayed ACK control data 75 * @icsk_mtup; MTU probing control data 76 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 77 * @icsk_user_timeout: TCP_USER_TIMEOUT value 78 */ 79 struct inet_connection_sock { 80 /* inet_sock has to be the first member! */ 81 struct inet_sock icsk_inet; 82 struct request_sock_queue icsk_accept_queue; 83 struct inet_bind_bucket *icsk_bind_hash; 84 struct inet_bind2_bucket *icsk_bind2_hash; 85 struct timer_list icsk_delack_timer; 86 union { 87 struct timer_list icsk_keepalive_timer; 88 struct timer_list mptcp_tout_timer; 89 }; 90 __u32 icsk_rto; 91 __u32 icsk_rto_min; 92 u32 icsk_rto_max; 93 __u32 icsk_delack_max; 94 __u32 icsk_pmtu_cookie; 95 const struct tcp_congestion_ops *icsk_ca_ops; 96 const struct inet_connection_sock_af_ops *icsk_af_ops; 97 const struct tcp_ulp_ops *icsk_ulp_ops; 98 void __rcu *icsk_ulp_data; 99 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 100 __u8 icsk_ca_state:5, 101 icsk_ca_initialized:1, 102 icsk_ca_setsockopt:1, 103 icsk_ca_dst_locked:1; 104 __u8 icsk_retransmits; 105 __u8 icsk_pending; 106 __u8 icsk_backoff; 107 __u8 icsk_syn_retries; 108 __u8 icsk_probes_out; 109 __u16 icsk_ext_hdr_len; 110 struct { 111 __u8 pending; /* ACK is pending */ 112 __u8 quick; /* Scheduled number of quick acks */ 113 __u8 pingpong; /* The session is interactive */ 114 __u8 retry; /* Number of attempts */ 115 #define ATO_BITS 8 116 __u32 ato:ATO_BITS, /* Predicted tick of soft clock */ 117 lrcv_flowlabel:20, /* last received ipv6 flowlabel */ 118 dst_quick_ack:1, /* cache dst RTAX_QUICKACK */ 119 unused:3; 120 __u32 lrcvtime; /* timestamp of last received data packet */ 121 __u16 last_seg_size; /* Size of last incoming segment */ 122 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 123 } icsk_ack; 124 struct { 125 /* Range of MTUs to search */ 126 int search_high; 127 int search_low; 128 129 /* Information on the current probe. */ 130 u32 probe_size:31, 131 /* Is the MTUP feature enabled for this connection? */ 132 enabled:1; 133 134 u32 probe_timestamp; 135 } icsk_mtup; 136 u32 icsk_probes_tstamp; 137 u32 icsk_user_timeout; 138 139 u64 icsk_ca_priv[104 / sizeof(u64)]; 140 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) 141 }; 142 143 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 144 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 145 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 146 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 147 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 148 149 #define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.sk) 150 151 static inline void *inet_csk_ca(const struct sock *sk) 152 { 153 return (void *)inet_csk(sk)->icsk_ca_priv; 154 } 155 156 struct sock *inet_csk_clone_lock(const struct sock *sk, 157 const struct request_sock *req, 158 const gfp_t priority); 159 160 enum inet_csk_ack_state_t { 161 ICSK_ACK_SCHED = 1, 162 ICSK_ACK_TIMER = 2, 163 ICSK_ACK_PUSHED = 4, 164 ICSK_ACK_PUSHED2 = 8, 165 ICSK_ACK_NOW = 16, /* Send the next ACK immediately (once) */ 166 ICSK_ACK_NOMEM = 32, 167 }; 168 169 void inet_csk_init_xmit_timers(struct sock *sk, 170 void (*retransmit_handler)(struct timer_list *), 171 void (*delack_handler)(struct timer_list *), 172 void (*keepalive_handler)(struct timer_list *)); 173 void inet_csk_clear_xmit_timers(struct sock *sk); 174 void inet_csk_clear_xmit_timers_sync(struct sock *sk); 175 176 static inline void inet_csk_schedule_ack(struct sock *sk) 177 { 178 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 179 } 180 181 static inline int inet_csk_ack_scheduled(const struct sock *sk) 182 { 183 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 184 } 185 186 static inline void inet_csk_delack_init(struct sock *sk) 187 { 188 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 189 } 190 191 static inline unsigned long tcp_timeout_expires(const struct sock *sk) 192 { 193 return READ_ONCE(sk->tcp_retransmit_timer.expires); 194 } 195 196 static inline unsigned long 197 icsk_delack_timeout(const struct inet_connection_sock *icsk) 198 { 199 return READ_ONCE(icsk->icsk_delack_timer.expires); 200 } 201 202 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 203 { 204 struct inet_connection_sock *icsk = inet_csk(sk); 205 206 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 207 smp_store_release(&icsk->icsk_pending, 0); 208 #ifdef INET_CSK_CLEAR_TIMERS 209 sk_stop_timer(sk, &sk->tcp_retransmit_timer); 210 #endif 211 } else if (what == ICSK_TIME_DACK) { 212 smp_store_release(&icsk->icsk_ack.pending, 0); 213 icsk->icsk_ack.retry = 0; 214 #ifdef INET_CSK_CLEAR_TIMERS 215 sk_stop_timer(sk, &icsk->icsk_delack_timer); 216 #endif 217 } else { 218 pr_debug("inet_csk BUG: unknown timer value\n"); 219 } 220 } 221 222 /* 223 * Reset the retransmission timer 224 */ 225 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 226 unsigned long when, 227 const unsigned long max_when) 228 { 229 struct inet_connection_sock *icsk = inet_csk(sk); 230 231 if (when > max_when) { 232 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 233 sk, what, when, (void *)_THIS_IP_); 234 when = max_when; 235 } 236 237 when += jiffies; 238 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 239 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 240 smp_store_release(&icsk->icsk_pending, what); 241 sk_reset_timer(sk, &sk->tcp_retransmit_timer, when); 242 } else if (what == ICSK_TIME_DACK) { 243 smp_store_release(&icsk->icsk_ack.pending, 244 icsk->icsk_ack.pending | ICSK_ACK_TIMER); 245 sk_reset_timer(sk, &icsk->icsk_delack_timer, when); 246 } else { 247 pr_debug("inet_csk BUG: unknown timer value\n"); 248 } 249 } 250 251 static inline unsigned long 252 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 253 unsigned long max_when) 254 { 255 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 256 257 return (unsigned long)min_t(u64, when, max_when); 258 } 259 260 struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg); 261 262 int inet_csk_get_port(struct sock *sk, unsigned short snum); 263 264 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 265 const struct request_sock *req); 266 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 267 struct sock *newsk, 268 const struct request_sock *req); 269 270 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 271 struct request_sock *req, 272 struct sock *child); 273 bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req); 274 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 275 struct request_sock *req, 276 bool own_req); 277 278 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 279 { 280 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 281 } 282 283 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 284 { 285 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 286 } 287 288 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 289 { 290 return inet_csk_reqsk_queue_len(sk) > READ_ONCE(sk->sk_max_ack_backlog); 291 } 292 293 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 294 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 295 296 void inet_csk_destroy_sock(struct sock *sk); 297 void inet_csk_prepare_for_destroy_sock(struct sock *sk); 298 void inet_csk_prepare_forced_close(struct sock *sk); 299 300 /* 301 * LISTEN is a special case for poll.. 302 */ 303 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 304 { 305 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 306 (EPOLLIN | EPOLLRDNORM) : 0; 307 } 308 309 int inet_csk_listen_start(struct sock *sk); 310 void inet_csk_listen_stop(struct sock *sk); 311 312 /* update the fast reuse flag when adding a socket */ 313 void inet_csk_update_fastreuse(const struct sock *sk, 314 struct inet_bind_bucket *tb, 315 struct inet_bind2_bucket *tb2); 316 317 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 318 319 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 320 { 321 inet_csk(sk)->icsk_ack.pingpong = 322 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 323 } 324 325 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 326 { 327 inet_csk(sk)->icsk_ack.pingpong = 0; 328 } 329 330 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 331 { 332 return 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_inc_pingpong_cnt(struct sock *sk) 337 { 338 struct inet_connection_sock *icsk = inet_csk(sk); 339 340 if (icsk->icsk_ack.pingpong < U8_MAX) 341 icsk->icsk_ack.pingpong++; 342 } 343 344 static inline bool inet_csk_has_ulp(const struct sock *sk) 345 { 346 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops; 347 } 348 349 static inline void inet_init_csk_locks(struct sock *sk) 350 { 351 struct inet_connection_sock *icsk = inet_csk(sk); 352 353 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock); 354 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock); 355 } 356 357 #endif /* _INET_CONNECTION_SOCK_H */ 358