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)(const struct sock *sk, struct sk_buff *skb, 45 struct request_sock *req, 46 struct dst_entry *dst, 47 struct request_sock *req_unhash, 48 bool *own_req); 49 u16 net_header_len; 50 u16 net_frag_header_len; 51 u16 sockaddr_len; 52 int (*setsockopt)(struct sock *sk, int level, int optname, 53 char __user *optval, unsigned int optlen); 54 int (*getsockopt)(struct sock *sk, int level, int optname, 55 char __user *optval, int __user *optlen); 56 #ifdef CONFIG_COMPAT 57 int (*compat_setsockopt)(struct sock *sk, 58 int level, int optname, 59 char __user *optval, unsigned int optlen); 60 int (*compat_getsockopt)(struct sock *sk, 61 int level, int optname, 62 char __user *optval, int __user *optlen); 63 #endif 64 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 65 int (*bind_conflict)(const struct sock *sk, 66 const struct inet_bind_bucket *tb, bool relax); 67 void (*mtu_reduced)(struct sock *sk); 68 }; 69 70 /** inet_connection_sock - INET connection oriented sock 71 * 72 * @icsk_accept_queue: FIFO of established children 73 * @icsk_bind_hash: Bind node 74 * @icsk_timeout: Timeout 75 * @icsk_retransmit_timer: Resend (no ack) 76 * @icsk_rto: Retransmit timeout 77 * @icsk_pmtu_cookie Last pmtu seen by socket 78 * @icsk_ca_ops Pluggable congestion control hook 79 * @icsk_af_ops Operations which are AF_INET{4,6} specific 80 * @icsk_ca_state: Congestion control state 81 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 82 * @icsk_pending: Scheduled timer event 83 * @icsk_backoff: Backoff 84 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 85 * @icsk_probes_out: unanswered 0 window probes 86 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 87 * @icsk_ack: Delayed ACK control data 88 * @icsk_mtup; MTU probing control data 89 */ 90 struct inet_connection_sock { 91 /* inet_sock has to be the first member! */ 92 struct inet_sock icsk_inet; 93 struct request_sock_queue icsk_accept_queue; 94 struct inet_bind_bucket *icsk_bind_hash; 95 unsigned long icsk_timeout; 96 struct timer_list icsk_retransmit_timer; 97 struct timer_list icsk_delack_timer; 98 __u32 icsk_rto; 99 __u32 icsk_pmtu_cookie; 100 const struct tcp_congestion_ops *icsk_ca_ops; 101 const struct inet_connection_sock_af_ops *icsk_af_ops; 102 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 103 __u8 icsk_ca_state:6, 104 icsk_ca_setsockopt:1, 105 icsk_ca_dst_locked:1; 106 __u8 icsk_retransmits; 107 __u8 icsk_pending; 108 __u8 icsk_backoff; 109 __u8 icsk_syn_retries; 110 __u8 icsk_probes_out; 111 __u16 icsk_ext_hdr_len; 112 struct { 113 __u8 pending; /* ACK is pending */ 114 __u8 quick; /* Scheduled number of quick acks */ 115 __u8 pingpong; /* The session is interactive */ 116 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 117 __u32 ato; /* Predicted tick of soft clock */ 118 unsigned long timeout; /* Currently scheduled timeout */ 119 __u32 lrcvtime; /* timestamp of last received data packet */ 120 __u16 last_seg_size; /* Size of last incoming segment */ 121 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 122 } icsk_ack; 123 struct { 124 int enabled; 125 126 /* Range of MTUs to search */ 127 int search_high; 128 int search_low; 129 130 /* Information on the current probe. */ 131 int probe_size; 132 133 u32 probe_timestamp; 134 } icsk_mtup; 135 u32 icsk_user_timeout; 136 137 u64 icsk_ca_priv[64 / sizeof(u64)]; 138 #define ICSK_CA_PRIV_SIZE (8 * sizeof(u64)) 139 }; 140 141 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 142 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 143 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 144 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 145 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 146 147 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 148 { 149 return (struct inet_connection_sock *)sk; 150 } 151 152 static inline void *inet_csk_ca(const struct sock *sk) 153 { 154 return (void *)inet_csk(sk)->icsk_ca_priv; 155 } 156 157 struct sock *inet_csk_clone_lock(const struct sock *sk, 158 const struct request_sock *req, 159 const gfp_t priority); 160 161 enum inet_csk_ack_state_t { 162 ICSK_ACK_SCHED = 1, 163 ICSK_ACK_TIMER = 2, 164 ICSK_ACK_PUSHED = 4, 165 ICSK_ACK_PUSHED2 = 8 166 }; 167 168 void inet_csk_init_xmit_timers(struct sock *sk, 169 void (*retransmit_handler)(unsigned long), 170 void (*delack_handler)(unsigned long), 171 void (*keepalive_handler)(unsigned long)); 172 void inet_csk_clear_xmit_timers(struct sock *sk); 173 174 static inline void inet_csk_schedule_ack(struct sock *sk) 175 { 176 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 177 } 178 179 static inline int inet_csk_ack_scheduled(const struct sock *sk) 180 { 181 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 182 } 183 184 static inline void inet_csk_delack_init(struct sock *sk) 185 { 186 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 187 } 188 189 void inet_csk_delete_keepalive_timer(struct sock *sk); 190 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 191 192 #ifdef INET_CSK_DEBUG 193 extern const char inet_csk_timer_bug_msg[]; 194 #endif 195 196 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 197 { 198 struct inet_connection_sock *icsk = inet_csk(sk); 199 200 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 201 icsk->icsk_pending = 0; 202 #ifdef INET_CSK_CLEAR_TIMERS 203 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 204 #endif 205 } else if (what == ICSK_TIME_DACK) { 206 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 207 #ifdef INET_CSK_CLEAR_TIMERS 208 sk_stop_timer(sk, &icsk->icsk_delack_timer); 209 #endif 210 } 211 #ifdef INET_CSK_DEBUG 212 else { 213 pr_debug("%s", inet_csk_timer_bug_msg); 214 } 215 #endif 216 } 217 218 /* 219 * Reset the retransmission timer 220 */ 221 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 222 unsigned long when, 223 const unsigned long max_when) 224 { 225 struct inet_connection_sock *icsk = inet_csk(sk); 226 227 if (when > max_when) { 228 #ifdef INET_CSK_DEBUG 229 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 230 sk, what, when, current_text_addr()); 231 #endif 232 when = max_when; 233 } 234 235 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 236 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE) { 237 icsk->icsk_pending = what; 238 icsk->icsk_timeout = jiffies + when; 239 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 240 } else if (what == ICSK_TIME_DACK) { 241 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 242 icsk->icsk_ack.timeout = jiffies + when; 243 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 244 } 245 #ifdef INET_CSK_DEBUG 246 else { 247 pr_debug("%s", inet_csk_timer_bug_msg); 248 } 249 #endif 250 } 251 252 static inline unsigned long 253 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 254 unsigned long max_when) 255 { 256 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 257 258 return (unsigned long)min_t(u64, when, max_when); 259 } 260 261 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err); 262 263 int inet_csk_bind_conflict(const struct sock *sk, 264 const struct inet_bind_bucket *tb, bool relax); 265 int inet_csk_get_port(struct sock *sk, unsigned short snum); 266 267 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 268 const struct request_sock *req); 269 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 270 struct sock *newsk, 271 const struct request_sock *req); 272 273 void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req, 274 struct sock *child); 275 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 276 unsigned long timeout); 277 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 278 struct request_sock *req, 279 bool own_req); 280 281 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 282 { 283 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 284 } 285 286 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 287 { 288 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 289 } 290 291 static inline int inet_csk_reqsk_queue_young(const struct sock *sk) 292 { 293 return reqsk_queue_len_young(&inet_csk(sk)->icsk_accept_queue); 294 } 295 296 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 297 { 298 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 299 } 300 301 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 302 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 303 304 void inet_csk_destroy_sock(struct sock *sk); 305 void inet_csk_prepare_forced_close(struct sock *sk); 306 307 /* 308 * LISTEN is a special case for poll.. 309 */ 310 static inline unsigned int inet_csk_listen_poll(const struct sock *sk) 311 { 312 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 313 (POLLIN | POLLRDNORM) : 0; 314 } 315 316 int inet_csk_listen_start(struct sock *sk, int backlog); 317 void inet_csk_listen_stop(struct sock *sk); 318 319 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 320 321 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 322 char __user *optval, int __user *optlen); 323 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 324 char __user *optval, unsigned int optlen); 325 326 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 327 #endif /* _INET_CONNECTION_SOCK_H */ 328