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; 102 __u8 icsk_retransmits; 103 __u8 icsk_pending; 104 __u8 icsk_backoff; 105 __u8 icsk_syn_retries; 106 __u8 icsk_probes_out; 107 __u16 icsk_ext_hdr_len; 108 struct { 109 __u8 pending; /* ACK is pending */ 110 __u8 quick; /* Scheduled number of quick acks */ 111 __u8 pingpong; /* The session is interactive */ 112 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 113 __u32 ato; /* Predicted tick of soft clock */ 114 unsigned long timeout; /* Currently scheduled timeout */ 115 __u32 lrcvtime; /* timestamp of last received data packet */ 116 __u16 last_seg_size; /* Size of last incoming segment */ 117 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 118 } icsk_ack; 119 struct { 120 int enabled; 121 122 /* Range of MTUs to search */ 123 int search_high; 124 int search_low; 125 126 /* Information on the current probe. */ 127 int probe_size; 128 } icsk_mtup; 129 u32 icsk_ca_priv[16]; 130 u32 icsk_user_timeout; 131 #define ICSK_CA_PRIV_SIZE (16 * sizeof(u32)) 132 }; 133 134 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 135 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 136 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 137 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 138 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 139 140 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 141 { 142 return (struct inet_connection_sock *)sk; 143 } 144 145 static inline void *inet_csk_ca(const struct sock *sk) 146 { 147 return (void *)inet_csk(sk)->icsk_ca_priv; 148 } 149 150 struct sock *inet_csk_clone_lock(const struct sock *sk, 151 const struct request_sock *req, 152 const gfp_t priority); 153 154 enum inet_csk_ack_state_t { 155 ICSK_ACK_SCHED = 1, 156 ICSK_ACK_TIMER = 2, 157 ICSK_ACK_PUSHED = 4, 158 ICSK_ACK_PUSHED2 = 8 159 }; 160 161 void inet_csk_init_xmit_timers(struct sock *sk, 162 void (*retransmit_handler)(unsigned long), 163 void (*delack_handler)(unsigned long), 164 void (*keepalive_handler)(unsigned long)); 165 void inet_csk_clear_xmit_timers(struct sock *sk); 166 167 static inline void inet_csk_schedule_ack(struct sock *sk) 168 { 169 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 170 } 171 172 static inline int inet_csk_ack_scheduled(const struct sock *sk) 173 { 174 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 175 } 176 177 static inline void inet_csk_delack_init(struct sock *sk) 178 { 179 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 180 } 181 182 void inet_csk_delete_keepalive_timer(struct sock *sk); 183 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 184 185 #ifdef INET_CSK_DEBUG 186 extern const char inet_csk_timer_bug_msg[]; 187 #endif 188 189 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 190 { 191 struct inet_connection_sock *icsk = inet_csk(sk); 192 193 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 194 icsk->icsk_pending = 0; 195 #ifdef INET_CSK_CLEAR_TIMERS 196 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 197 #endif 198 } else if (what == ICSK_TIME_DACK) { 199 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 200 #ifdef INET_CSK_CLEAR_TIMERS 201 sk_stop_timer(sk, &icsk->icsk_delack_timer); 202 #endif 203 } 204 #ifdef INET_CSK_DEBUG 205 else { 206 pr_debug("%s", inet_csk_timer_bug_msg); 207 } 208 #endif 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 #ifdef INET_CSK_DEBUG 222 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 223 sk, what, when, current_text_addr()); 224 #endif 225 when = max_when; 226 } 227 228 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 229 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE) { 230 icsk->icsk_pending = what; 231 icsk->icsk_timeout = jiffies + when; 232 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 233 } else if (what == ICSK_TIME_DACK) { 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 } 238 #ifdef INET_CSK_DEBUG 239 else { 240 pr_debug("%s", inet_csk_timer_bug_msg); 241 } 242 #endif 243 } 244 245 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err); 246 247 struct request_sock *inet_csk_search_req(const struct sock *sk, 248 struct request_sock ***prevp, 249 const __be16 rport, 250 const __be32 raddr, 251 const __be32 laddr); 252 int inet_csk_bind_conflict(const struct sock *sk, 253 const struct inet_bind_bucket *tb, bool relax); 254 int inet_csk_get_port(struct sock *sk, unsigned short snum); 255 256 struct dst_entry *inet_csk_route_req(struct sock *sk, struct flowi4 *fl4, 257 const struct request_sock *req); 258 struct dst_entry *inet_csk_route_child_sock(struct sock *sk, struct sock *newsk, 259 const struct request_sock *req); 260 261 static inline void inet_csk_reqsk_queue_add(struct sock *sk, 262 struct request_sock *req, 263 struct sock *child) 264 { 265 reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child); 266 } 267 268 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 269 unsigned long timeout); 270 271 static inline void inet_csk_reqsk_queue_removed(struct sock *sk, 272 struct request_sock *req) 273 { 274 if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0) 275 inet_csk_delete_keepalive_timer(sk); 276 } 277 278 static inline void inet_csk_reqsk_queue_added(struct sock *sk, 279 const unsigned long timeout) 280 { 281 if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0) 282 inet_csk_reset_keepalive_timer(sk, timeout); 283 } 284 285 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 286 { 287 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 288 } 289 290 static inline int inet_csk_reqsk_queue_young(const struct sock *sk) 291 { 292 return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue); 293 } 294 295 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 296 { 297 return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue); 298 } 299 300 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk, 301 struct request_sock *req, 302 struct request_sock **prev) 303 { 304 reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev); 305 } 306 307 static inline void inet_csk_reqsk_queue_drop(struct sock *sk, 308 struct request_sock *req, 309 struct request_sock **prev) 310 { 311 inet_csk_reqsk_queue_unlink(sk, req, prev); 312 inet_csk_reqsk_queue_removed(sk, req); 313 reqsk_free(req); 314 } 315 316 void inet_csk_reqsk_queue_prune(struct sock *parent, 317 const unsigned long interval, 318 const unsigned long timeout, 319 const unsigned long max_rto); 320 321 void inet_csk_destroy_sock(struct sock *sk); 322 void inet_csk_prepare_forced_close(struct sock *sk); 323 324 /* 325 * LISTEN is a special case for poll.. 326 */ 327 static inline unsigned int inet_csk_listen_poll(const struct sock *sk) 328 { 329 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 330 (POLLIN | POLLRDNORM) : 0; 331 } 332 333 int inet_csk_listen_start(struct sock *sk, const int nr_table_entries); 334 void inet_csk_listen_stop(struct sock *sk); 335 336 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 337 338 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 339 char __user *optval, int __user *optlen); 340 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 341 char __user *optval, unsigned int optlen); 342 343 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 344 #endif /* _INET_CONNECTION_SOCK_H */ 345