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/ip.h> 19 #include <linux/string.h> 20 #include <linux/timer.h> 21 #include <net/request_sock.h> 22 23 #define INET_CSK_DEBUG 1 24 25 /* Cancel timers, when they are not required. */ 26 #undef INET_CSK_CLEAR_TIMERS 27 28 struct inet_bind_bucket; 29 struct inet_hashinfo; 30 struct tcp_congestion_ops; 31 32 /** inet_connection_sock - INET connection oriented sock 33 * 34 * @icsk_accept_queue: FIFO of established children 35 * @icsk_bind_hash: Bind node 36 * @icsk_timeout: Timeout 37 * @icsk_retransmit_timer: Resend (no ack) 38 * @icsk_rto: Retransmit timeout 39 * @icsk_ca_ops Pluggable congestion control hook 40 * @icsk_ca_state: Congestion control state 41 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 42 * @icsk_pending: Scheduled timer event 43 * @icsk_backoff: Backoff 44 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 45 * @icsk_probes_out: unanswered 0 window probes 46 * @icsk_ack: Delayed ACK control data 47 */ 48 struct inet_connection_sock { 49 /* inet_sock has to be the first member! */ 50 struct inet_sock icsk_inet; 51 struct request_sock_queue icsk_accept_queue; 52 struct inet_bind_bucket *icsk_bind_hash; 53 unsigned long icsk_timeout; 54 struct timer_list icsk_retransmit_timer; 55 struct timer_list icsk_delack_timer; 56 __u32 icsk_rto; 57 struct tcp_congestion_ops *icsk_ca_ops; 58 __u8 icsk_ca_state; 59 __u8 icsk_retransmits; 60 __u8 icsk_pending; 61 __u8 icsk_backoff; 62 __u8 icsk_syn_retries; 63 __u8 icsk_probes_out; 64 /* 2 BYTES HOLE, TRY TO PACK! */ 65 struct { 66 __u8 pending; /* ACK is pending */ 67 __u8 quick; /* Scheduled number of quick acks */ 68 __u8 pingpong; /* The session is interactive */ 69 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 70 __u32 ato; /* Predicted tick of soft clock */ 71 unsigned long timeout; /* Currently scheduled timeout */ 72 __u32 lrcvtime; /* timestamp of last received data packet */ 73 __u16 last_seg_size; /* Size of last incoming segment */ 74 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 75 } icsk_ack; 76 u32 icsk_ca_priv[16]; 77 #define ICSK_CA_PRIV_SIZE (16 * sizeof(u32)) 78 }; 79 80 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 81 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 82 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 83 #define ICSK_TIME_KEEPOPEN 4 /* Keepalive timer */ 84 85 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 86 { 87 return (struct inet_connection_sock *)sk; 88 } 89 90 static inline void *inet_csk_ca(const struct sock *sk) 91 { 92 return (void *)inet_csk(sk)->icsk_ca_priv; 93 } 94 95 extern struct sock *inet_csk_clone(struct sock *sk, 96 const struct request_sock *req, 97 const gfp_t priority); 98 99 enum inet_csk_ack_state_t { 100 ICSK_ACK_SCHED = 1, 101 ICSK_ACK_TIMER = 2, 102 ICSK_ACK_PUSHED = 4 103 }; 104 105 extern void inet_csk_init_xmit_timers(struct sock *sk, 106 void (*retransmit_handler)(unsigned long), 107 void (*delack_handler)(unsigned long), 108 void (*keepalive_handler)(unsigned long)); 109 extern void inet_csk_clear_xmit_timers(struct sock *sk); 110 111 static inline void inet_csk_schedule_ack(struct sock *sk) 112 { 113 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 114 } 115 116 static inline int inet_csk_ack_scheduled(const struct sock *sk) 117 { 118 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 119 } 120 121 static inline void inet_csk_delack_init(struct sock *sk) 122 { 123 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 124 } 125 126 extern void inet_csk_delete_keepalive_timer(struct sock *sk); 127 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 128 129 #ifdef INET_CSK_DEBUG 130 extern const char inet_csk_timer_bug_msg[]; 131 #endif 132 133 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 134 { 135 struct inet_connection_sock *icsk = inet_csk(sk); 136 137 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 138 icsk->icsk_pending = 0; 139 #ifdef INET_CSK_CLEAR_TIMERS 140 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 141 #endif 142 } else if (what == ICSK_TIME_DACK) { 143 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 144 #ifdef INET_CSK_CLEAR_TIMERS 145 sk_stop_timer(sk, &icsk->icsk_delack_timer); 146 #endif 147 } 148 #ifdef INET_CSK_DEBUG 149 else { 150 pr_debug("%s", inet_csk_timer_bug_msg); 151 } 152 #endif 153 } 154 155 /* 156 * Reset the retransmission timer 157 */ 158 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 159 unsigned long when, 160 const unsigned long max_when) 161 { 162 struct inet_connection_sock *icsk = inet_csk(sk); 163 164 if (when > max_when) { 165 #ifdef INET_CSK_DEBUG 166 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 167 sk, what, when, current_text_addr()); 168 #endif 169 when = max_when; 170 } 171 172 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 173 icsk->icsk_pending = what; 174 icsk->icsk_timeout = jiffies + when; 175 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 176 } else if (what == ICSK_TIME_DACK) { 177 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 178 icsk->icsk_ack.timeout = jiffies + when; 179 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 180 } 181 #ifdef INET_CSK_DEBUG 182 else { 183 pr_debug("%s", inet_csk_timer_bug_msg); 184 } 185 #endif 186 } 187 188 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err); 189 190 extern struct request_sock *inet_csk_search_req(const struct sock *sk, 191 struct request_sock ***prevp, 192 const __u16 rport, 193 const __u32 raddr, 194 const __u32 laddr); 195 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo, 196 struct sock *sk, unsigned short snum); 197 198 extern struct dst_entry* inet_csk_route_req(struct sock *sk, 199 const struct request_sock *req); 200 201 static inline void inet_csk_reqsk_queue_add(struct sock *sk, 202 struct request_sock *req, 203 struct sock *child) 204 { 205 reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child); 206 } 207 208 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk, 209 struct request_sock *req, 210 const unsigned timeout); 211 212 static inline void inet_csk_reqsk_queue_removed(struct sock *sk, 213 struct request_sock *req) 214 { 215 if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0) 216 inet_csk_delete_keepalive_timer(sk); 217 } 218 219 static inline void inet_csk_reqsk_queue_added(struct sock *sk, 220 const unsigned long timeout) 221 { 222 if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0) 223 inet_csk_reset_keepalive_timer(sk, timeout); 224 } 225 226 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 227 { 228 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 229 } 230 231 static inline int inet_csk_reqsk_queue_young(const struct sock *sk) 232 { 233 return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue); 234 } 235 236 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 237 { 238 return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue); 239 } 240 241 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk, 242 struct request_sock *req, 243 struct request_sock **prev) 244 { 245 reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev); 246 } 247 248 static inline void inet_csk_reqsk_queue_drop(struct sock *sk, 249 struct request_sock *req, 250 struct request_sock **prev) 251 { 252 inet_csk_reqsk_queue_unlink(sk, req, prev); 253 inet_csk_reqsk_queue_removed(sk, req); 254 reqsk_free(req); 255 } 256 257 extern void inet_csk_reqsk_queue_prune(struct sock *parent, 258 const unsigned long interval, 259 const unsigned long timeout, 260 const unsigned long max_rto); 261 262 extern void inet_csk_destroy_sock(struct sock *sk); 263 264 /* 265 * LISTEN is a special case for poll.. 266 */ 267 static inline unsigned int inet_csk_listen_poll(const struct sock *sk) 268 { 269 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 270 (POLLIN | POLLRDNORM) : 0; 271 } 272 273 extern int inet_csk_listen_start(struct sock *sk, const int nr_table_entries); 274 extern void inet_csk_listen_stop(struct sock *sk); 275 276 #endif /* _INET_CONNECTION_SOCK_H */ 277