1 /* 2 * NET Generic infrastructure for INET connection oriented protocols. 3 * 4 * Definitions for inet_connection_sock 5 * 6 * Authors: Many people, see the TCP sources 7 * 8 * From code originally in TCP 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 #ifndef _INET_CONNECTION_SOCK_H 16 #define _INET_CONNECTION_SOCK_H 17 18 #include <linux/compiler.h> 19 #include <linux/string.h> 20 #include <linux/timer.h> 21 #include <linux/poll.h> 22 23 #include <net/inet_sock.h> 24 #include <net/request_sock.h> 25 26 #define INET_CSK_DEBUG 1 27 28 /* Cancel timers, when they are not required. */ 29 #undef INET_CSK_CLEAR_TIMERS 30 31 struct inet_bind_bucket; 32 struct tcp_congestion_ops; 33 34 /* 35 * Pointers to address related TCP functions 36 * (i.e. things that depend on the address family) 37 */ 38 struct inet_connection_sock_af_ops { 39 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 40 void (*send_check)(struct sock *sk, struct sk_buff *skb); 41 int (*rebuild_header)(struct sock *sk); 42 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 43 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 44 struct sock *(*syn_recv_sock)(struct sock *sk, struct sk_buff *skb, 45 struct request_sock *req, 46 struct dst_entry *dst); 47 u16 net_header_len; 48 u16 net_frag_header_len; 49 u16 sockaddr_len; 50 int (*setsockopt)(struct sock *sk, int level, int optname, 51 char __user *optval, unsigned int optlen); 52 int (*getsockopt)(struct sock *sk, int level, int optname, 53 char __user *optval, int __user *optlen); 54 #ifdef CONFIG_COMPAT 55 int (*compat_setsockopt)(struct sock *sk, 56 int level, int optname, 57 char __user *optval, unsigned int optlen); 58 int (*compat_getsockopt)(struct sock *sk, 59 int level, int optname, 60 char __user *optval, int __user *optlen); 61 #endif 62 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 63 int (*bind_conflict)(const struct sock *sk, 64 const struct inet_bind_bucket *tb, bool relax); 65 void (*mtu_reduced)(struct sock *sk); 66 }; 67 68 /** inet_connection_sock - INET connection oriented sock 69 * 70 * @icsk_accept_queue: FIFO of established children 71 * @icsk_bind_hash: Bind node 72 * @icsk_timeout: Timeout 73 * @icsk_retransmit_timer: Resend (no ack) 74 * @icsk_rto: Retransmit timeout 75 * @icsk_pmtu_cookie Last pmtu seen by socket 76 * @icsk_ca_ops Pluggable congestion control hook 77 * @icsk_af_ops Operations which are AF_INET{4,6} specific 78 * @icsk_ca_state: Congestion control state 79 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 80 * @icsk_pending: Scheduled timer event 81 * @icsk_backoff: Backoff 82 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 83 * @icsk_probes_out: unanswered 0 window probes 84 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 85 * @icsk_ack: Delayed ACK control data 86 * @icsk_mtup; MTU probing control data 87 */ 88 struct inet_connection_sock { 89 /* inet_sock has to be the first member! */ 90 struct inet_sock icsk_inet; 91 struct request_sock_queue icsk_accept_queue; 92 struct inet_bind_bucket *icsk_bind_hash; 93 unsigned long icsk_timeout; 94 struct timer_list icsk_retransmit_timer; 95 struct timer_list icsk_delack_timer; 96 __u32 icsk_rto; 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 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 101 __u8 icsk_ca_state:7, 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 blocked; /* Delayed ACK was blocked by socket lock */ 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 int enabled; 122 123 /* Range of MTUs to search */ 124 int search_high; 125 int search_low; 126 127 /* Information on the current probe. */ 128 int probe_size; 129 } icsk_mtup; 130 u32 icsk_ca_priv[16]; 131 u32 icsk_user_timeout; 132 #define ICSK_CA_PRIV_SIZE (16 * sizeof(u32)) 133 }; 134 135 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 136 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 137 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 138 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 139 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 140 141 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 142 { 143 return (struct inet_connection_sock *)sk; 144 } 145 146 static inline void *inet_csk_ca(const struct sock *sk) 147 { 148 return (void *)inet_csk(sk)->icsk_ca_priv; 149 } 150 151 struct sock *inet_csk_clone_lock(const struct sock *sk, 152 const struct request_sock *req, 153 const gfp_t priority); 154 155 enum inet_csk_ack_state_t { 156 ICSK_ACK_SCHED = 1, 157 ICSK_ACK_TIMER = 2, 158 ICSK_ACK_PUSHED = 4, 159 ICSK_ACK_PUSHED2 = 8 160 }; 161 162 void inet_csk_init_xmit_timers(struct sock *sk, 163 void (*retransmit_handler)(unsigned long), 164 void (*delack_handler)(unsigned long), 165 void (*keepalive_handler)(unsigned long)); 166 void inet_csk_clear_xmit_timers(struct sock *sk); 167 168 static inline void inet_csk_schedule_ack(struct sock *sk) 169 { 170 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 171 } 172 173 static inline int inet_csk_ack_scheduled(const struct sock *sk) 174 { 175 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 176 } 177 178 static inline void inet_csk_delack_init(struct sock *sk) 179 { 180 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 181 } 182 183 void inet_csk_delete_keepalive_timer(struct sock *sk); 184 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 185 186 #ifdef INET_CSK_DEBUG 187 extern const char inet_csk_timer_bug_msg[]; 188 #endif 189 190 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 191 { 192 struct inet_connection_sock *icsk = inet_csk(sk); 193 194 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 195 icsk->icsk_pending = 0; 196 #ifdef INET_CSK_CLEAR_TIMERS 197 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 198 #endif 199 } else if (what == ICSK_TIME_DACK) { 200 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 201 #ifdef INET_CSK_CLEAR_TIMERS 202 sk_stop_timer(sk, &icsk->icsk_delack_timer); 203 #endif 204 } 205 #ifdef INET_CSK_DEBUG 206 else { 207 pr_debug("%s", inet_csk_timer_bug_msg); 208 } 209 #endif 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 #ifdef INET_CSK_DEBUG 223 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 224 sk, what, when, current_text_addr()); 225 #endif 226 when = max_when; 227 } 228 229 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 230 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE) { 231 icsk->icsk_pending = what; 232 icsk->icsk_timeout = jiffies + when; 233 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 234 } else if (what == ICSK_TIME_DACK) { 235 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 236 icsk->icsk_ack.timeout = jiffies + when; 237 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 238 } 239 #ifdef INET_CSK_DEBUG 240 else { 241 pr_debug("%s", inet_csk_timer_bug_msg); 242 } 243 #endif 244 } 245 246 static inline unsigned long 247 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 248 unsigned long max_when) 249 { 250 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 251 252 return (unsigned long)min_t(u64, when, max_when); 253 } 254 255 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err); 256 257 struct request_sock *inet_csk_search_req(const struct sock *sk, 258 struct request_sock ***prevp, 259 const __be16 rport, 260 const __be32 raddr, 261 const __be32 laddr); 262 int inet_csk_bind_conflict(const struct sock *sk, 263 const struct inet_bind_bucket *tb, bool relax); 264 int inet_csk_get_port(struct sock *sk, unsigned short snum); 265 266 struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4, 267 const struct request_sock *req); 268 struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk, 269 const struct request_sock *req); 270 271 static inline void inet_csk_reqsk_queue_add(struct sock *sk, 272 struct request_sock *req, 273 struct sock *child) 274 { 275 reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child); 276 } 277 278 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 279 unsigned long timeout); 280 281 static inline void inet_csk_reqsk_queue_removed(struct sock *sk, 282 struct request_sock *req) 283 { 284 if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0) 285 inet_csk_delete_keepalive_timer(sk); 286 } 287 288 static inline void inet_csk_reqsk_queue_added(struct sock *sk, 289 const unsigned long timeout) 290 { 291 if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0) 292 inet_csk_reset_keepalive_timer(sk, timeout); 293 } 294 295 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 296 { 297 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 298 } 299 300 static inline int inet_csk_reqsk_queue_young(const struct sock *sk) 301 { 302 return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue); 303 } 304 305 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 306 { 307 return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue); 308 } 309 310 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk, 311 struct request_sock *req, 312 struct request_sock **prev) 313 { 314 reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev); 315 } 316 317 static inline void inet_csk_reqsk_queue_drop(struct sock *sk, 318 struct request_sock *req, 319 struct request_sock **prev) 320 { 321 inet_csk_reqsk_queue_unlink(sk, req, prev); 322 inet_csk_reqsk_queue_removed(sk, req); 323 reqsk_free(req); 324 } 325 326 void inet_csk_reqsk_queue_prune(struct sock *parent, 327 const unsigned long interval, 328 const unsigned long timeout, 329 const unsigned long max_rto); 330 331 void inet_csk_destroy_sock(struct sock *sk); 332 void inet_csk_prepare_forced_close(struct sock *sk); 333 334 /* 335 * LISTEN is a special case for poll.. 336 */ 337 static inline unsigned int inet_csk_listen_poll(const struct sock *sk) 338 { 339 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 340 (POLLIN | POLLRDNORM) : 0; 341 } 342 343 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries); 344 void inet_csk_listen_stop(struct sock *sk); 345 346 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 347 348 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 349 char __user *optval, int __user *optlen); 350 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 351 char __user *optval, unsigned int optlen); 352 353 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 354 #endif /* _INET_CONNECTION_SOCK_H */ 355