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 #include <linux/kernel.h> 23 24 #include <net/inet_sock.h> 25 #include <net/request_sock.h> 26 27 /* Cancel timers, when they are not required. */ 28 #undef INET_CSK_CLEAR_TIMERS 29 30 struct inet_bind_bucket; 31 struct tcp_congestion_ops; 32 33 /* 34 * Pointers to address related TCP functions 35 * (i.e. things that depend on the address family) 36 */ 37 struct inet_connection_sock_af_ops { 38 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 39 void (*send_check)(struct sock *sk, struct sk_buff *skb); 40 int (*rebuild_header)(struct sock *sk); 41 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 42 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 43 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb, 44 struct request_sock *req, 45 struct dst_entry *dst, 46 struct request_sock *req_unhash, 47 bool *own_req); 48 u16 net_header_len; 49 u16 net_frag_header_len; 50 u16 sockaddr_len; 51 int (*setsockopt)(struct sock *sk, int level, int optname, 52 char __user *optval, unsigned int optlen); 53 int (*getsockopt)(struct sock *sk, int level, int optname, 54 char __user *optval, int __user *optlen); 55 #ifdef CONFIG_COMPAT 56 int (*compat_setsockopt)(struct sock *sk, 57 int level, int optname, 58 char __user *optval, unsigned int optlen); 59 int (*compat_getsockopt)(struct sock *sk, 60 int level, int optname, 61 char __user *optval, int __user *optlen); 62 #endif 63 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 64 void (*mtu_reduced)(struct sock *sk); 65 }; 66 67 /** inet_connection_sock - INET connection oriented sock 68 * 69 * @icsk_accept_queue: FIFO of established children 70 * @icsk_bind_hash: Bind node 71 * @icsk_timeout: Timeout 72 * @icsk_retransmit_timer: Resend (no ack) 73 * @icsk_rto: Retransmit timeout 74 * @icsk_pmtu_cookie Last pmtu seen by socket 75 * @icsk_ca_ops Pluggable congestion control hook 76 * @icsk_af_ops Operations which are AF_INET{4,6} specific 77 * @icsk_ulp_ops Pluggable ULP control hook 78 * @icsk_ulp_data ULP private data 79 * @icsk_clean_acked Clean acked data hook 80 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable 81 * @icsk_ca_state: Congestion control state 82 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 83 * @icsk_pending: Scheduled timer event 84 * @icsk_backoff: Backoff 85 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 86 * @icsk_probes_out: unanswered 0 window probes 87 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 88 * @icsk_ack: Delayed ACK control data 89 * @icsk_mtup; MTU probing control data 90 */ 91 struct inet_connection_sock { 92 /* inet_sock has to be the first member! */ 93 struct inet_sock icsk_inet; 94 struct request_sock_queue icsk_accept_queue; 95 struct inet_bind_bucket *icsk_bind_hash; 96 unsigned long icsk_timeout; 97 struct timer_list icsk_retransmit_timer; 98 struct timer_list icsk_delack_timer; 99 __u32 icsk_rto; 100 __u32 icsk_pmtu_cookie; 101 const struct tcp_congestion_ops *icsk_ca_ops; 102 const struct inet_connection_sock_af_ops *icsk_af_ops; 103 const struct tcp_ulp_ops *icsk_ulp_ops; 104 void *icsk_ulp_data; 105 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 106 struct hlist_node icsk_listen_portaddr_node; 107 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 108 __u8 icsk_ca_state:6, 109 icsk_ca_setsockopt:1, 110 icsk_ca_dst_locked:1; 111 __u8 icsk_retransmits; 112 __u8 icsk_pending; 113 __u8 icsk_backoff; 114 __u8 icsk_syn_retries; 115 __u8 icsk_probes_out; 116 __u16 icsk_ext_hdr_len; 117 struct { 118 __u8 pending; /* ACK is pending */ 119 __u8 quick; /* Scheduled number of quick acks */ 120 __u8 pingpong; /* The session is interactive */ 121 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 122 __u32 ato; /* Predicted tick of soft clock */ 123 unsigned long timeout; /* Currently scheduled timeout */ 124 __u32 lrcvtime; /* timestamp of last received data packet */ 125 __u16 last_seg_size; /* Size of last incoming segment */ 126 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 127 } icsk_ack; 128 struct { 129 int enabled; 130 131 /* Range of MTUs to search */ 132 int search_high; 133 int search_low; 134 135 /* Information on the current probe. */ 136 int probe_size; 137 138 u32 probe_timestamp; 139 } icsk_mtup; 140 u32 icsk_user_timeout; 141 142 u64 icsk_ca_priv[104 / sizeof(u64)]; 143 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64)) 144 }; 145 146 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 147 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 148 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 149 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 150 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 151 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 152 153 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 154 { 155 return (struct inet_connection_sock *)sk; 156 } 157 158 static inline void *inet_csk_ca(const struct sock *sk) 159 { 160 return (void *)inet_csk(sk)->icsk_ca_priv; 161 } 162 163 struct sock *inet_csk_clone_lock(const struct sock *sk, 164 const struct request_sock *req, 165 const gfp_t priority); 166 167 enum inet_csk_ack_state_t { 168 ICSK_ACK_SCHED = 1, 169 ICSK_ACK_TIMER = 2, 170 ICSK_ACK_PUSHED = 4, 171 ICSK_ACK_PUSHED2 = 8, 172 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 173 }; 174 175 void inet_csk_init_xmit_timers(struct sock *sk, 176 void (*retransmit_handler)(struct timer_list *), 177 void (*delack_handler)(struct timer_list *), 178 void (*keepalive_handler)(struct timer_list *)); 179 void inet_csk_clear_xmit_timers(struct sock *sk); 180 181 static inline void inet_csk_schedule_ack(struct sock *sk) 182 { 183 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 184 } 185 186 static inline int inet_csk_ack_scheduled(const struct sock *sk) 187 { 188 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 189 } 190 191 static inline void inet_csk_delack_init(struct sock *sk) 192 { 193 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 194 } 195 196 void inet_csk_delete_keepalive_timer(struct sock *sk); 197 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 198 199 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 200 { 201 struct inet_connection_sock *icsk = inet_csk(sk); 202 203 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 204 icsk->icsk_pending = 0; 205 #ifdef INET_CSK_CLEAR_TIMERS 206 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 207 #endif 208 } else if (what == ICSK_TIME_DACK) { 209 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 210 #ifdef INET_CSK_CLEAR_TIMERS 211 sk_stop_timer(sk, &icsk->icsk_delack_timer); 212 #endif 213 } else { 214 pr_debug("inet_csk BUG: unknown timer value\n"); 215 } 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 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 229 sk, what, when, (void *)_THIS_IP_); 230 when = max_when; 231 } 232 233 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 234 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE || 235 what == ICSK_TIME_REO_TIMEOUT) { 236 icsk->icsk_pending = what; 237 icsk->icsk_timeout = jiffies + when; 238 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 239 } else if (what == ICSK_TIME_DACK) { 240 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 241 icsk->icsk_ack.timeout = jiffies + when; 242 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 243 } else { 244 pr_debug("inet_csk BUG: unknown timer value\n"); 245 } 246 } 247 248 static inline unsigned long 249 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 250 unsigned long max_when) 251 { 252 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 253 254 return (unsigned long)min_t(u64, when, max_when); 255 } 256 257 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 258 259 int inet_csk_get_port(struct sock *sk, unsigned short snum); 260 261 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 262 const struct request_sock *req); 263 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 264 struct sock *newsk, 265 const struct request_sock *req); 266 267 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 268 struct request_sock *req, 269 struct sock *child); 270 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 271 unsigned long timeout); 272 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 273 struct request_sock *req, 274 bool own_req); 275 276 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 277 { 278 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 279 } 280 281 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 282 { 283 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 284 } 285 286 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 287 { 288 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 289 } 290 291 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 292 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 293 294 void inet_csk_destroy_sock(struct sock *sk); 295 void inet_csk_prepare_forced_close(struct sock *sk); 296 297 /* 298 * LISTEN is a special case for poll.. 299 */ 300 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 301 { 302 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 303 (EPOLLIN | EPOLLRDNORM) : 0; 304 } 305 306 int inet_csk_listen_start(struct sock *sk, int backlog); 307 void inet_csk_listen_stop(struct sock *sk); 308 309 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 310 311 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 312 char __user *optval, int __user *optlen); 313 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 314 char __user *optval, unsigned int optlen); 315 316 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 317 318 #define TCP_PINGPONG_THRESH 3 319 320 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 321 { 322 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; 323 } 324 325 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 326 { 327 inet_csk(sk)->icsk_ack.pingpong = 0; 328 } 329 330 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 331 { 332 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 333 } 334 335 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 336 { 337 struct inet_connection_sock *icsk = inet_csk(sk); 338 339 if (icsk->icsk_ack.pingpong < U8_MAX) 340 icsk->icsk_ack.pingpong++; 341 } 342 #endif /* _INET_CONNECTION_SOCK_H */ 343