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 u16 sockaddr_len; 48 int (*setsockopt)(struct sock *sk, int level, int optname, 49 sockptr_t optval, unsigned int optlen); 50 int (*getsockopt)(struct sock *sk, int level, int optname, 51 char __user *optval, int __user *optlen); 52 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 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_timeout: Timeout 62 * @icsk_retransmit_timer: Resend (no ack) 63 * @icsk_rto: Retransmit timeout 64 * @icsk_pmtu_cookie Last pmtu seen by socket 65 * @icsk_ca_ops Pluggable congestion control hook 66 * @icsk_af_ops Operations which are AF_INET{4,6} specific 67 * @icsk_ulp_ops Pluggable ULP control hook 68 * @icsk_ulp_data ULP private data 69 * @icsk_clean_acked Clean acked data hook 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 unsigned long icsk_timeout; 89 struct timer_list icsk_retransmit_timer; 90 struct timer_list icsk_delack_timer; 91 __u32 icsk_rto; 92 __u32 icsk_rto_min; 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 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 100 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 101 __u8 icsk_ca_state:5, 102 icsk_ca_initialized:1, 103 icsk_ca_setsockopt:1, 104 icsk_ca_dst_locked:1; 105 __u8 icsk_retransmits; 106 __u8 icsk_pending; 107 __u8 icsk_backoff; 108 __u8 icsk_syn_retries; 109 __u8 icsk_probes_out; 110 __u16 icsk_ext_hdr_len; 111 struct { 112 __u8 pending; /* ACK is pending */ 113 __u8 quick; /* Scheduled number of quick acks */ 114 __u8 pingpong; /* The session is interactive */ 115 __u8 retry; /* Number of attempts */ 116 #define ATO_BITS 8 117 __u32 ato:ATO_BITS, /* Predicted tick of soft clock */ 118 lrcv_flowlabel:20, /* last received ipv6 flowlabel */ 119 unused:4; 120 unsigned long timeout; /* Currently scheduled timeout */ 121 __u32 lrcvtime; /* timestamp of last received data packet */ 122 __u16 last_seg_size; /* Size of last incoming segment */ 123 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 124 } icsk_ack; 125 struct { 126 /* Range of MTUs to search */ 127 int search_high; 128 int search_low; 129 130 /* Information on the current probe. */ 131 u32 probe_size:31, 132 /* Is the MTUP feature enabled for this connection? */ 133 enabled:1; 134 135 u32 probe_timestamp; 136 } icsk_mtup; 137 u32 icsk_probes_tstamp; 138 u32 icsk_user_timeout; 139 140 u64 icsk_ca_priv[104 / sizeof(u64)]; 141 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) 142 }; 143 144 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 145 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 146 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 147 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 148 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 149 150 #define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.sk) 151 152 static inline void *inet_csk_ca(const struct sock *sk) 153 { 154 return (void *)inet_csk(sk)->icsk_ca_priv; 155 } 156 157 struct sock *inet_csk_clone_lock(const struct sock *sk, 158 const struct request_sock *req, 159 const gfp_t priority); 160 161 enum inet_csk_ack_state_t { 162 ICSK_ACK_SCHED = 1, 163 ICSK_ACK_TIMER = 2, 164 ICSK_ACK_PUSHED = 4, 165 ICSK_ACK_PUSHED2 = 8, 166 ICSK_ACK_NOW = 16, /* Send the next ACK immediately (once) */ 167 ICSK_ACK_NOMEM = 32, 168 }; 169 170 void inet_csk_init_xmit_timers(struct sock *sk, 171 void (*retransmit_handler)(struct timer_list *), 172 void (*delack_handler)(struct timer_list *), 173 void (*keepalive_handler)(struct timer_list *)); 174 void inet_csk_clear_xmit_timers(struct sock *sk); 175 void inet_csk_clear_xmit_timers_sync(struct sock *sk); 176 177 static inline void inet_csk_schedule_ack(struct sock *sk) 178 { 179 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 180 } 181 182 static inline int inet_csk_ack_scheduled(const struct sock *sk) 183 { 184 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 185 } 186 187 static inline void inet_csk_delack_init(struct sock *sk) 188 { 189 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 190 } 191 192 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 193 { 194 struct inet_connection_sock *icsk = inet_csk(sk); 195 196 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 197 smp_store_release(&icsk->icsk_pending, 0); 198 #ifdef INET_CSK_CLEAR_TIMERS 199 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 200 #endif 201 } else if (what == ICSK_TIME_DACK) { 202 smp_store_release(&icsk->icsk_ack.pending, 0); 203 icsk->icsk_ack.retry = 0; 204 #ifdef INET_CSK_CLEAR_TIMERS 205 sk_stop_timer(sk, &icsk->icsk_delack_timer); 206 #endif 207 } else { 208 pr_debug("inet_csk BUG: unknown timer value\n"); 209 } 210 } 211 212 /* 213 * Reset the retransmission timer 214 */ 215 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 216 unsigned long when, 217 const unsigned long max_when) 218 { 219 struct inet_connection_sock *icsk = inet_csk(sk); 220 221 if (when > max_when) { 222 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 223 sk, what, when, (void *)_THIS_IP_); 224 when = max_when; 225 } 226 227 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 228 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 229 smp_store_release(&icsk->icsk_pending, what); 230 icsk->icsk_timeout = jiffies + when; 231 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 232 } else if (what == ICSK_TIME_DACK) { 233 smp_store_release(&icsk->icsk_ack.pending, 234 icsk->icsk_ack.pending | ICSK_ACK_TIMER); 235 icsk->icsk_ack.timeout = jiffies + when; 236 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 237 } else { 238 pr_debug("inet_csk BUG: unknown timer value\n"); 239 } 240 } 241 242 static inline unsigned long 243 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 244 unsigned long max_when) 245 { 246 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 247 248 return (unsigned long)min_t(u64, when, max_when); 249 } 250 251 struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg); 252 253 int inet_csk_get_port(struct sock *sk, unsigned short snum); 254 255 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 256 const struct request_sock *req); 257 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 258 struct sock *newsk, 259 const struct request_sock *req); 260 261 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 262 struct request_sock *req, 263 struct sock *child); 264 bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 265 unsigned long timeout); 266 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 267 struct request_sock *req, 268 bool own_req); 269 270 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 271 { 272 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 273 } 274 275 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 276 { 277 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 278 } 279 280 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 281 { 282 return inet_csk_reqsk_queue_len(sk) > READ_ONCE(sk->sk_max_ack_backlog); 283 } 284 285 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 286 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 287 288 static inline unsigned long 289 reqsk_timeout(struct request_sock *req, unsigned long max_timeout) 290 { 291 u64 timeout = (u64)req->timeout << req->num_timeout; 292 293 return (unsigned long)min_t(u64, timeout, max_timeout); 294 } 295 296 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 297 { 298 /* The below has to be done to allow calling inet_csk_destroy_sock */ 299 sock_set_flag(sk, SOCK_DEAD); 300 this_cpu_inc(*sk->sk_prot->orphan_count); 301 } 302 303 void inet_csk_destroy_sock(struct sock *sk); 304 void inet_csk_prepare_forced_close(struct sock *sk); 305 306 /* 307 * LISTEN is a special case for poll.. 308 */ 309 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 310 { 311 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 312 (EPOLLIN | EPOLLRDNORM) : 0; 313 } 314 315 int inet_csk_listen_start(struct sock *sk); 316 void inet_csk_listen_stop(struct sock *sk); 317 318 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 319 320 /* update the fast reuse flag when adding a socket */ 321 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 322 struct sock *sk); 323 324 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 325 326 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 327 { 328 inet_csk(sk)->icsk_ack.pingpong = 329 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 330 } 331 332 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 333 { 334 inet_csk(sk)->icsk_ack.pingpong = 0; 335 } 336 337 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 338 { 339 return inet_csk(sk)->icsk_ack.pingpong >= 340 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); 341 } 342 343 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 344 { 345 struct inet_connection_sock *icsk = inet_csk(sk); 346 347 if (icsk->icsk_ack.pingpong < U8_MAX) 348 icsk->icsk_ack.pingpong++; 349 } 350 351 static inline bool inet_csk_has_ulp(const struct sock *sk) 352 { 353 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops; 354 } 355 356 static inline void inet_init_csk_locks(struct sock *sk) 357 { 358 struct inet_connection_sock *icsk = inet_csk(sk); 359 360 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock); 361 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock); 362 } 363 364 #endif /* _INET_CONNECTION_SOCK_H */ 365