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 void (*opt_child_init)(struct sock *newsk, 47 const struct sock *sk)); 48 u16 net_header_len; 49 int (*setsockopt)(struct sock *sk, int level, int optname, 50 sockptr_t optval, unsigned int optlen); 51 int (*getsockopt)(struct sock *sk, int level, int optname, 52 char __user *optval, int __user *optlen); 53 void (*mtu_reduced)(struct sock *sk); 54 }; 55 56 /** inet_connection_sock - INET connection oriented sock 57 * 58 * @icsk_accept_queue: FIFO of established children 59 * @icsk_bind_hash: Bind node 60 * @icsk_bind2_hash: Bind node in the bhash2 table 61 * @icsk_delack_timer: Delayed ACK timer 62 * @icsk_keepalive_timer: Keepalive timer 63 * @mptcp_tout_timer: mptcp timer 64 * @icsk_rto: Retransmit timeout 65 * @icsk_pmtu_cookie Last pmtu seen by socket 66 * @icsk_ca_ops Pluggable congestion control hook 67 * @icsk_af_ops Operations which are AF_INET{4,6} specific 68 * @icsk_ulp_ops Pluggable ULP control hook 69 * @icsk_ulp_data ULP private data 70 * @icsk_ca_state: Congestion control state 71 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 72 * @icsk_pending: Scheduled timer event 73 * @icsk_backoff: Backoff 74 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 75 * @icsk_probes_out: unanswered 0 window probes 76 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 77 * @icsk_ack: Delayed ACK control data 78 * @icsk_mtup; MTU probing control data 79 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 80 * @icsk_user_timeout: TCP_USER_TIMEOUT value 81 */ 82 struct inet_connection_sock { 83 /* inet_sock has to be the first member! */ 84 struct inet_sock icsk_inet; 85 struct request_sock_queue icsk_accept_queue; 86 struct inet_bind_bucket *icsk_bind_hash; 87 struct inet_bind2_bucket *icsk_bind2_hash; 88 struct timer_list icsk_delack_timer; 89 union { 90 struct timer_list icsk_keepalive_timer; 91 struct timer_list mptcp_tout_timer; 92 }; 93 __u32 icsk_rto; 94 __u32 icsk_rto_min; 95 u32 icsk_rto_max; 96 __u32 icsk_delack_max; 97 __u32 icsk_pmtu_cookie; 98 const struct tcp_congestion_ops *icsk_ca_ops; 99 const struct inet_connection_sock_af_ops *icsk_af_ops; 100 const struct tcp_ulp_ops *icsk_ulp_ops; 101 void __rcu *icsk_ulp_data; 102 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 103 __u8 icsk_ca_state:5, 104 icsk_ca_initialized:1, 105 icsk_ca_setsockopt:1, 106 icsk_ca_dst_locked:1; 107 __u8 icsk_retransmits; 108 __u8 icsk_pending; 109 __u8 icsk_backoff; 110 __u8 icsk_syn_retries; 111 __u8 icsk_probes_out; 112 __u16 icsk_ext_hdr_len; 113 struct { 114 __u8 pending; /* ACK is pending */ 115 __u8 quick; /* Scheduled number of quick acks */ 116 __u8 pingpong; /* The session is interactive */ 117 __u8 retry; /* Number of attempts */ 118 #define ATO_BITS 8 119 __u32 ato:ATO_BITS, /* Predicted tick of soft clock */ 120 lrcv_flowlabel:20, /* last received ipv6 flowlabel */ 121 dst_quick_ack:1, /* cache dst RTAX_QUICKACK */ 122 unused:3; 123 __u32 lrcvtime; /* timestamp of last received data packet */ 124 __u16 last_seg_size; /* Size of last incoming segment */ 125 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 126 } icsk_ack; 127 struct { 128 /* Range of MTUs to search */ 129 int search_high; 130 int search_low; 131 132 /* Information on the current probe. */ 133 u32 probe_size:31, 134 /* Is the MTUP feature enabled for this connection? */ 135 enabled:1; 136 137 u32 probe_timestamp; 138 } icsk_mtup; 139 u32 icsk_probes_tstamp; 140 u32 icsk_user_timeout; 141 142 u64 icsk_ca_priv[104 / sizeof(u64)]; 143 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) 144 }; 145 146 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 147 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 148 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 149 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 150 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 151 152 #define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.sk) 153 154 static inline void *inet_csk_ca(const struct sock *sk) 155 { 156 return (void *)inet_csk(sk)->icsk_ca_priv; 157 } 158 159 struct sock *inet_csk_clone_lock(const struct sock *sk, 160 const struct request_sock *req, 161 const gfp_t priority); 162 163 enum inet_csk_ack_state_t { 164 ICSK_ACK_SCHED = 1, 165 ICSK_ACK_TIMER = 2, 166 ICSK_ACK_PUSHED = 4, 167 ICSK_ACK_PUSHED2 = 8, 168 ICSK_ACK_NOW = 16, /* Send the next ACK immediately (once) */ 169 ICSK_ACK_NOMEM = 32, 170 }; 171 172 void inet_csk_init_xmit_timers(struct sock *sk, 173 void (*retransmit_handler)(struct timer_list *), 174 void (*delack_handler)(struct timer_list *), 175 void (*keepalive_handler)(struct timer_list *)); 176 void inet_csk_clear_xmit_timers(struct sock *sk); 177 void inet_csk_clear_xmit_timers_sync(struct sock *sk); 178 179 static inline void inet_csk_schedule_ack(struct sock *sk) 180 { 181 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 182 } 183 184 static inline int inet_csk_ack_scheduled(const struct sock *sk) 185 { 186 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 187 } 188 189 static inline void inet_csk_delack_init(struct sock *sk) 190 { 191 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 192 } 193 194 static inline unsigned long tcp_timeout_expires(const struct sock *sk) 195 { 196 return READ_ONCE(sk->tcp_retransmit_timer.expires); 197 } 198 199 static inline unsigned long 200 icsk_delack_timeout(const struct inet_connection_sock *icsk) 201 { 202 return READ_ONCE(icsk->icsk_delack_timer.expires); 203 } 204 205 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 206 { 207 struct inet_connection_sock *icsk = inet_csk(sk); 208 209 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 210 smp_store_release(&icsk->icsk_pending, 0); 211 #ifdef INET_CSK_CLEAR_TIMERS 212 sk_stop_timer(sk, &sk->tcp_retransmit_timer); 213 #endif 214 } else if (what == ICSK_TIME_DACK) { 215 smp_store_release(&icsk->icsk_ack.pending, 0); 216 icsk->icsk_ack.retry = 0; 217 #ifdef INET_CSK_CLEAR_TIMERS 218 sk_stop_timer(sk, &icsk->icsk_delack_timer); 219 #endif 220 } else { 221 pr_debug("inet_csk BUG: unknown timer value\n"); 222 } 223 } 224 225 /* 226 * Reset the retransmission timer 227 */ 228 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 229 unsigned long when, 230 const unsigned long max_when) 231 { 232 struct inet_connection_sock *icsk = inet_csk(sk); 233 234 if (when > max_when) { 235 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 236 sk, what, when, (void *)_THIS_IP_); 237 when = max_when; 238 } 239 240 when += jiffies; 241 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 242 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 243 smp_store_release(&icsk->icsk_pending, what); 244 sk_reset_timer(sk, &sk->tcp_retransmit_timer, when); 245 } else if (what == ICSK_TIME_DACK) { 246 smp_store_release(&icsk->icsk_ack.pending, 247 icsk->icsk_ack.pending | ICSK_ACK_TIMER); 248 sk_reset_timer(sk, &icsk->icsk_delack_timer, when); 249 } else { 250 pr_debug("inet_csk BUG: unknown timer value\n"); 251 } 252 } 253 254 static inline unsigned long 255 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 256 unsigned long max_when) 257 { 258 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 259 260 return (unsigned long)min_t(u64, when, max_when); 261 } 262 263 struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg); 264 265 int inet_csk_get_port(struct sock *sk, unsigned short snum); 266 267 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 268 const struct request_sock *req); 269 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 270 struct sock *newsk, 271 const struct request_sock *req); 272 273 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 274 struct request_sock *req, 275 struct sock *child); 276 bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req); 277 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 278 struct request_sock *req, 279 bool own_req); 280 281 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 282 { 283 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 284 } 285 286 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 287 { 288 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 289 } 290 291 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 292 { 293 return inet_csk_reqsk_queue_len(sk) > READ_ONCE(sk->sk_max_ack_backlog); 294 } 295 296 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 297 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 298 299 void inet_csk_destroy_sock(struct sock *sk); 300 void inet_csk_prepare_for_destroy_sock(struct sock *sk); 301 void inet_csk_prepare_forced_close(struct sock *sk); 302 303 /* 304 * LISTEN is a special case for poll.. 305 */ 306 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 307 { 308 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 309 (EPOLLIN | EPOLLRDNORM) : 0; 310 } 311 312 int inet_csk_listen_start(struct sock *sk); 313 void inet_csk_listen_stop(struct sock *sk); 314 315 /* update the fast reuse flag when adding a socket */ 316 void inet_csk_update_fastreuse(const struct sock *sk, 317 struct inet_bind_bucket *tb, 318 struct inet_bind2_bucket *tb2); 319 320 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 321 322 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 323 { 324 inet_csk(sk)->icsk_ack.pingpong = 325 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 326 } 327 328 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 329 { 330 inet_csk(sk)->icsk_ack.pingpong = 0; 331 } 332 333 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 334 { 335 return inet_csk(sk)->icsk_ack.pingpong >= 336 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 337 } 338 339 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 340 { 341 struct inet_connection_sock *icsk = inet_csk(sk); 342 343 if (icsk->icsk_ack.pingpong < U8_MAX) 344 icsk->icsk_ack.pingpong++; 345 } 346 347 static inline bool inet_csk_has_ulp(const struct sock *sk) 348 { 349 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops; 350 } 351 352 static inline void inet_init_csk_locks(struct sock *sk) 353 { 354 struct inet_connection_sock *icsk = inet_csk(sk); 355 356 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock); 357 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock); 358 } 359 360 #endif /* _INET_CONNECTION_SOCK_H */ 361