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 22 #include <net/inet_sock.h> 23 #include <net/request_sock.h> 24 25 #define INET_CSK_DEBUG 1 26 27 /* Cancel timers, when they are not required. */ 28 #undef INET_CSK_CLEAR_TIMERS 29 30 struct inet_bind_bucket; 31 struct inet_hashinfo; 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 sk_buff *skb, int ipfragok); 40 void (*send_check)(struct sock *sk, int len, 41 struct sk_buff *skb); 42 int (*rebuild_header)(struct sock *sk); 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 int (*remember_stamp)(struct sock *sk); 48 __u16 net_header_len; 49 int (*setsockopt)(struct sock *sk, int level, int optname, 50 char __user *optval, int optlen); 51 int (*getsockopt)(struct sock *sk, int level, int optname, 52 char __user *optval, int __user *optlen); 53 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 54 int sockaddr_len; 55 }; 56 57 /** inet_connection_sock - INET connection oriented sock 58 * 59 * @icsk_accept_queue: FIFO of established children 60 * @icsk_bind_hash: Bind node 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_ca_state: Congestion control state 68 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 69 * @icsk_pending: Scheduled timer event 70 * @icsk_backoff: Backoff 71 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 72 * @icsk_probes_out: unanswered 0 window probes 73 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 74 * @icsk_ack: Delayed ACK control data 75 */ 76 struct inet_connection_sock { 77 /* inet_sock has to be the first member! */ 78 struct inet_sock icsk_inet; 79 struct request_sock_queue icsk_accept_queue; 80 struct inet_bind_bucket *icsk_bind_hash; 81 unsigned long icsk_timeout; 82 struct timer_list icsk_retransmit_timer; 83 struct timer_list icsk_delack_timer; 84 __u32 icsk_rto; 85 __u32 icsk_pmtu_cookie; 86 struct tcp_congestion_ops *icsk_ca_ops; 87 struct inet_connection_sock_af_ops *icsk_af_ops; 88 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 89 __u8 icsk_ca_state; 90 __u8 icsk_retransmits; 91 __u8 icsk_pending; 92 __u8 icsk_backoff; 93 __u8 icsk_syn_retries; 94 __u8 icsk_probes_out; 95 __u16 icsk_ext_hdr_len; 96 struct { 97 __u8 pending; /* ACK is pending */ 98 __u8 quick; /* Scheduled number of quick acks */ 99 __u8 pingpong; /* The session is interactive */ 100 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 101 __u32 ato; /* Predicted tick of soft clock */ 102 unsigned long timeout; /* Currently scheduled timeout */ 103 __u32 lrcvtime; /* timestamp of last received data packet */ 104 __u16 last_seg_size; /* Size of last incoming segment */ 105 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 106 } icsk_ack; 107 u32 icsk_ca_priv[16]; 108 #define ICSK_CA_PRIV_SIZE (16 * sizeof(u32)) 109 }; 110 111 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 112 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 113 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 114 #define ICSK_TIME_KEEPOPEN 4 /* Keepalive timer */ 115 116 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 117 { 118 return (struct inet_connection_sock *)sk; 119 } 120 121 static inline void *inet_csk_ca(const struct sock *sk) 122 { 123 return (void *)inet_csk(sk)->icsk_ca_priv; 124 } 125 126 extern struct sock *inet_csk_clone(struct sock *sk, 127 const struct request_sock *req, 128 const gfp_t priority); 129 130 enum inet_csk_ack_state_t { 131 ICSK_ACK_SCHED = 1, 132 ICSK_ACK_TIMER = 2, 133 ICSK_ACK_PUSHED = 4 134 }; 135 136 extern void inet_csk_init_xmit_timers(struct sock *sk, 137 void (*retransmit_handler)(unsigned long), 138 void (*delack_handler)(unsigned long), 139 void (*keepalive_handler)(unsigned long)); 140 extern void inet_csk_clear_xmit_timers(struct sock *sk); 141 142 static inline void inet_csk_schedule_ack(struct sock *sk) 143 { 144 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 145 } 146 147 static inline int inet_csk_ack_scheduled(const struct sock *sk) 148 { 149 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 150 } 151 152 static inline void inet_csk_delack_init(struct sock *sk) 153 { 154 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 155 } 156 157 extern void inet_csk_delete_keepalive_timer(struct sock *sk); 158 extern void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 159 160 #ifdef INET_CSK_DEBUG 161 extern const char inet_csk_timer_bug_msg[]; 162 #endif 163 164 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 165 { 166 struct inet_connection_sock *icsk = inet_csk(sk); 167 168 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 169 icsk->icsk_pending = 0; 170 #ifdef INET_CSK_CLEAR_TIMERS 171 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 172 #endif 173 } else if (what == ICSK_TIME_DACK) { 174 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 175 #ifdef INET_CSK_CLEAR_TIMERS 176 sk_stop_timer(sk, &icsk->icsk_delack_timer); 177 #endif 178 } 179 #ifdef INET_CSK_DEBUG 180 else { 181 pr_debug("%s", inet_csk_timer_bug_msg); 182 } 183 #endif 184 } 185 186 /* 187 * Reset the retransmission timer 188 */ 189 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 190 unsigned long when, 191 const unsigned long max_when) 192 { 193 struct inet_connection_sock *icsk = inet_csk(sk); 194 195 if (when > max_when) { 196 #ifdef INET_CSK_DEBUG 197 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 198 sk, what, when, current_text_addr()); 199 #endif 200 when = max_when; 201 } 202 203 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 204 icsk->icsk_pending = what; 205 icsk->icsk_timeout = jiffies + when; 206 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 207 } else if (what == ICSK_TIME_DACK) { 208 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 209 icsk->icsk_ack.timeout = jiffies + when; 210 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 211 } 212 #ifdef INET_CSK_DEBUG 213 else { 214 pr_debug("%s", inet_csk_timer_bug_msg); 215 } 216 #endif 217 } 218 219 extern struct sock *inet_csk_accept(struct sock *sk, int flags, int *err); 220 221 extern struct request_sock *inet_csk_search_req(const struct sock *sk, 222 struct request_sock ***prevp, 223 const __u16 rport, 224 const __u32 raddr, 225 const __u32 laddr); 226 extern int inet_csk_bind_conflict(const struct sock *sk, 227 const struct inet_bind_bucket *tb); 228 extern int inet_csk_get_port(struct inet_hashinfo *hashinfo, 229 struct sock *sk, unsigned short snum, 230 int (*bind_conflict)(const struct sock *sk, 231 const struct inet_bind_bucket *tb)); 232 233 extern struct dst_entry* inet_csk_route_req(struct sock *sk, 234 const struct request_sock *req); 235 236 static inline void inet_csk_reqsk_queue_add(struct sock *sk, 237 struct request_sock *req, 238 struct sock *child) 239 { 240 reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child); 241 } 242 243 extern void inet_csk_reqsk_queue_hash_add(struct sock *sk, 244 struct request_sock *req, 245 unsigned long timeout); 246 247 static inline void inet_csk_reqsk_queue_removed(struct sock *sk, 248 struct request_sock *req) 249 { 250 if (reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req) == 0) 251 inet_csk_delete_keepalive_timer(sk); 252 } 253 254 static inline void inet_csk_reqsk_queue_added(struct sock *sk, 255 const unsigned long timeout) 256 { 257 if (reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue) == 0) 258 inet_csk_reset_keepalive_timer(sk, timeout); 259 } 260 261 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 262 { 263 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 264 } 265 266 static inline int inet_csk_reqsk_queue_young(const struct sock *sk) 267 { 268 return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue); 269 } 270 271 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 272 { 273 return reqsk_queue_is_full(&inet_csk(sk)->icsk_accept_queue); 274 } 275 276 static inline void inet_csk_reqsk_queue_unlink(struct sock *sk, 277 struct request_sock *req, 278 struct request_sock **prev) 279 { 280 reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req, prev); 281 } 282 283 static inline void inet_csk_reqsk_queue_drop(struct sock *sk, 284 struct request_sock *req, 285 struct request_sock **prev) 286 { 287 inet_csk_reqsk_queue_unlink(sk, req, prev); 288 inet_csk_reqsk_queue_removed(sk, req); 289 reqsk_free(req); 290 } 291 292 extern void inet_csk_reqsk_queue_prune(struct sock *parent, 293 const unsigned long interval, 294 const unsigned long timeout, 295 const unsigned long max_rto); 296 297 extern void inet_csk_destroy_sock(struct sock *sk); 298 299 /* 300 * LISTEN is a special case for poll.. 301 */ 302 static inline unsigned int inet_csk_listen_poll(const struct sock *sk) 303 { 304 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 305 (POLLIN | POLLRDNORM) : 0; 306 } 307 308 extern int inet_csk_listen_start(struct sock *sk, const int nr_table_entries); 309 extern void inet_csk_listen_stop(struct sock *sk); 310 311 extern void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 312 313 #endif /* _INET_CONNECTION_SOCK_H */ 314