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 tcp_congestion_ops; 29 30 /* 31 * Pointers to address related TCP functions 32 * (i.e. things that depend on the address family) 33 */ 34 struct inet_connection_sock_af_ops { 35 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 36 void (*send_check)(struct sock *sk, struct sk_buff *skb); 37 int (*rebuild_header)(struct sock *sk); 38 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 39 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 40 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb, 41 struct request_sock *req, 42 struct dst_entry *dst, 43 struct request_sock *req_unhash, 44 bool *own_req); 45 u16 net_header_len; 46 u16 net_frag_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_timeout: Timeout 61 * @icsk_retransmit_timer: Resend (no ack) 62 * @icsk_rto: Retransmit timeout 63 * @icsk_pmtu_cookie Last pmtu seen by socket 64 * @icsk_ca_ops Pluggable congestion control hook 65 * @icsk_af_ops Operations which are AF_INET{4,6} specific 66 * @icsk_ulp_ops Pluggable ULP control hook 67 * @icsk_ulp_data ULP private data 68 * @icsk_clean_acked Clean acked data hook 69 * @icsk_ca_state: Congestion control state 70 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 71 * @icsk_pending: Scheduled timer event 72 * @icsk_backoff: Backoff 73 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 74 * @icsk_probes_out: unanswered 0 window probes 75 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 76 * @icsk_ack: Delayed ACK control data 77 * @icsk_mtup; MTU probing control data 78 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 79 * @icsk_user_timeout: TCP_USER_TIMEOUT value 80 */ 81 struct inet_connection_sock { 82 /* inet_sock has to be the first member! */ 83 struct inet_sock icsk_inet; 84 struct request_sock_queue icsk_accept_queue; 85 struct inet_bind_bucket *icsk_bind_hash; 86 unsigned long icsk_timeout; 87 struct timer_list icsk_retransmit_timer; 88 struct timer_list icsk_delack_timer; 89 __u32 icsk_rto; 90 __u32 icsk_rto_min; 91 __u32 icsk_delack_max; 92 __u32 icsk_pmtu_cookie; 93 const struct tcp_congestion_ops *icsk_ca_ops; 94 const struct inet_connection_sock_af_ops *icsk_af_ops; 95 const struct tcp_ulp_ops *icsk_ulp_ops; 96 void __rcu *icsk_ulp_data; 97 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 98 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 99 __u8 icsk_ca_state:5, 100 icsk_ca_initialized:1, 101 icsk_ca_setsockopt:1, 102 icsk_ca_dst_locked:1; 103 __u8 icsk_retransmits; 104 __u8 icsk_pending; 105 __u8 icsk_backoff; 106 __u8 icsk_syn_retries; 107 __u8 icsk_probes_out; 108 __u16 icsk_ext_hdr_len; 109 struct { 110 __u8 pending; /* ACK is pending */ 111 __u8 quick; /* Scheduled number of quick acks */ 112 __u8 pingpong; /* The session is interactive */ 113 __u8 retry; /* Number of attempts */ 114 __u32 ato; /* Predicted tick of soft clock */ 115 unsigned long timeout; /* Currently scheduled timeout */ 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 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 146 { 147 return (struct inet_connection_sock *)sk; 148 } 149 150 static inline void *inet_csk_ca(const struct sock *sk) 151 { 152 return (void *)inet_csk(sk)->icsk_ca_priv; 153 } 154 155 struct sock *inet_csk_clone_lock(const struct sock *sk, 156 const struct request_sock *req, 157 const gfp_t priority); 158 159 enum inet_csk_ack_state_t { 160 ICSK_ACK_SCHED = 1, 161 ICSK_ACK_TIMER = 2, 162 ICSK_ACK_PUSHED = 4, 163 ICSK_ACK_PUSHED2 = 8, 164 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 165 }; 166 167 void inet_csk_init_xmit_timers(struct sock *sk, 168 void (*retransmit_handler)(struct timer_list *), 169 void (*delack_handler)(struct timer_list *), 170 void (*keepalive_handler)(struct timer_list *)); 171 void inet_csk_clear_xmit_timers(struct sock *sk); 172 173 static inline void inet_csk_schedule_ack(struct sock *sk) 174 { 175 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 176 } 177 178 static inline int inet_csk_ack_scheduled(const struct sock *sk) 179 { 180 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 181 } 182 183 static inline void inet_csk_delack_init(struct sock *sk) 184 { 185 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 186 } 187 188 void inet_csk_delete_keepalive_timer(struct sock *sk); 189 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 190 191 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 192 { 193 struct inet_connection_sock *icsk = inet_csk(sk); 194 195 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 196 icsk->icsk_pending = 0; 197 #ifdef INET_CSK_CLEAR_TIMERS 198 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 199 #endif 200 } else if (what == ICSK_TIME_DACK) { 201 icsk->icsk_ack.pending = 0; 202 icsk->icsk_ack.retry = 0; 203 #ifdef INET_CSK_CLEAR_TIMERS 204 sk_stop_timer(sk, &icsk->icsk_delack_timer); 205 #endif 206 } else { 207 pr_debug("inet_csk BUG: unknown timer value\n"); 208 } 209 } 210 211 /* 212 * Reset the retransmission timer 213 */ 214 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 215 unsigned long when, 216 const unsigned long max_when) 217 { 218 struct inet_connection_sock *icsk = inet_csk(sk); 219 220 if (when > max_when) { 221 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 222 sk, what, when, (void *)_THIS_IP_); 223 when = max_when; 224 } 225 226 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 227 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 228 icsk->icsk_pending = what; 229 icsk->icsk_timeout = jiffies + when; 230 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 231 } else if (what == ICSK_TIME_DACK) { 232 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 233 icsk->icsk_ack.timeout = jiffies + when; 234 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 235 } else { 236 pr_debug("inet_csk BUG: unknown timer value\n"); 237 } 238 } 239 240 static inline unsigned long 241 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 242 unsigned long max_when) 243 { 244 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 245 246 return (unsigned long)min_t(u64, when, max_when); 247 } 248 249 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 250 251 int inet_csk_get_port(struct sock *sk, unsigned short snum); 252 253 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 254 const struct request_sock *req); 255 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 256 struct sock *newsk, 257 const struct request_sock *req); 258 259 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 260 struct request_sock *req, 261 struct sock *child); 262 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 263 unsigned long timeout); 264 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 265 struct request_sock *req, 266 bool own_req); 267 268 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 269 { 270 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 271 } 272 273 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 274 { 275 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 276 } 277 278 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 279 { 280 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 281 } 282 283 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 284 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 285 286 static inline unsigned long 287 reqsk_timeout(struct request_sock *req, unsigned long max_timeout) 288 { 289 u64 timeout = (u64)req->timeout << req->num_timeout; 290 291 return (unsigned long)min_t(u64, timeout, max_timeout); 292 } 293 294 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 295 { 296 /* The below has to be done to allow calling inet_csk_destroy_sock */ 297 sock_set_flag(sk, SOCK_DEAD); 298 this_cpu_inc(*sk->sk_prot->orphan_count); 299 } 300 301 void inet_csk_destroy_sock(struct sock *sk); 302 void inet_csk_prepare_forced_close(struct sock *sk); 303 304 /* 305 * LISTEN is a special case for poll.. 306 */ 307 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 308 { 309 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 310 (EPOLLIN | EPOLLRDNORM) : 0; 311 } 312 313 int inet_csk_listen_start(struct sock *sk); 314 void inet_csk_listen_stop(struct sock *sk); 315 316 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 317 318 /* update the fast reuse flag when adding a socket */ 319 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 320 struct sock *sk); 321 322 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 323 324 #define TCP_PINGPONG_THRESH 3 325 326 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 327 { 328 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; 329 } 330 331 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 332 { 333 inet_csk(sk)->icsk_ack.pingpong = 0; 334 } 335 336 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 337 { 338 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 339 } 340 341 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 342 { 343 struct inet_connection_sock *icsk = inet_csk(sk); 344 345 if (icsk->icsk_ack.pingpong < U8_MAX) 346 icsk->icsk_ack.pingpong++; 347 } 348 349 static inline bool inet_csk_has_ulp(struct sock *sk) 350 { 351 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops; 352 } 353 354 #endif /* _INET_CONNECTION_SOCK_H */ 355