1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * NET Generic infrastructure for INET connection oriented protocols. 4 * 5 * Definitions for inet_connection_sock 6 * 7 * Authors: Many people, see the TCP sources 8 * 9 * From code originally in TCP 10 */ 11 #ifndef _INET_CONNECTION_SOCK_H 12 #define _INET_CONNECTION_SOCK_H 13 14 #include <linux/compiler.h> 15 #include <linux/string.h> 16 #include <linux/timer.h> 17 #include <linux/poll.h> 18 #include <linux/kernel.h> 19 20 #include <net/inet_sock.h> 21 #include <net/request_sock.h> 22 23 /* Cancel timers, when they are not required. */ 24 #undef INET_CSK_CLEAR_TIMERS 25 26 struct inet_bind_bucket; 27 struct tcp_congestion_ops; 28 29 /* 30 * Pointers to address related TCP functions 31 * (i.e. things that depend on the address family) 32 */ 33 struct inet_connection_sock_af_ops { 34 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 35 void (*send_check)(struct sock *sk, struct sk_buff *skb); 36 int (*rebuild_header)(struct sock *sk); 37 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 38 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 39 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb, 40 struct request_sock *req, 41 struct dst_entry *dst, 42 struct request_sock *req_unhash, 43 bool *own_req); 44 u16 net_header_len; 45 u16 net_frag_header_len; 46 u16 sockaddr_len; 47 int (*setsockopt)(struct sock *sk, int level, int optname, 48 char __user *optval, unsigned int optlen); 49 int (*getsockopt)(struct sock *sk, int level, int optname, 50 char __user *optval, int __user *optlen); 51 #ifdef CONFIG_COMPAT 52 int (*compat_setsockopt)(struct sock *sk, 53 int level, int optname, 54 char __user *optval, unsigned int optlen); 55 int (*compat_getsockopt)(struct sock *sk, 56 int level, int optname, 57 char __user *optval, int __user *optlen); 58 #endif 59 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 60 void (*mtu_reduced)(struct sock *sk); 61 }; 62 63 /** inet_connection_sock - INET connection oriented sock 64 * 65 * @icsk_accept_queue: FIFO of established children 66 * @icsk_bind_hash: Bind node 67 * @icsk_timeout: Timeout 68 * @icsk_retransmit_timer: Resend (no ack) 69 * @icsk_rto: Retransmit timeout 70 * @icsk_pmtu_cookie Last pmtu seen by socket 71 * @icsk_ca_ops Pluggable congestion control hook 72 * @icsk_af_ops Operations which are AF_INET{4,6} specific 73 * @icsk_ulp_ops Pluggable ULP control hook 74 * @icsk_ulp_data ULP private data 75 * @icsk_clean_acked Clean acked data hook 76 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable 77 * @icsk_ca_state: Congestion control state 78 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 79 * @icsk_pending: Scheduled timer event 80 * @icsk_backoff: Backoff 81 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 82 * @icsk_probes_out: unanswered 0 window probes 83 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 84 * @icsk_ack: Delayed ACK control data 85 * @icsk_mtup; MTU probing control data 86 */ 87 struct inet_connection_sock { 88 /* inet_sock has to be the first member! */ 89 struct inet_sock icsk_inet; 90 struct request_sock_queue icsk_accept_queue; 91 struct inet_bind_bucket *icsk_bind_hash; 92 unsigned long icsk_timeout; 93 struct timer_list icsk_retransmit_timer; 94 struct timer_list icsk_delack_timer; 95 __u32 icsk_rto; 96 __u32 icsk_pmtu_cookie; 97 const struct tcp_congestion_ops *icsk_ca_ops; 98 const struct inet_connection_sock_af_ops *icsk_af_ops; 99 const struct tcp_ulp_ops *icsk_ulp_ops; 100 void *icsk_ulp_data; 101 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 102 struct hlist_node icsk_listen_portaddr_node; 103 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 104 __u8 icsk_ca_state:6, 105 icsk_ca_setsockopt:1, 106 icsk_ca_dst_locked:1; 107 __u8 icsk_retransmits; 108 __u8 icsk_pending; 109 __u8 icsk_backoff; 110 __u8 icsk_syn_retries; 111 __u8 icsk_probes_out; 112 __u16 icsk_ext_hdr_len; 113 struct { 114 __u8 pending; /* ACK is pending */ 115 __u8 quick; /* Scheduled number of quick acks */ 116 __u8 pingpong; /* The session is interactive */ 117 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 118 __u32 ato; /* Predicted tick of soft clock */ 119 unsigned long timeout; /* Currently scheduled timeout */ 120 __u32 lrcvtime; /* timestamp of last received data packet */ 121 __u16 last_seg_size; /* Size of last incoming segment */ 122 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 123 } icsk_ack; 124 struct { 125 int enabled; 126 127 /* Range of MTUs to search */ 128 int search_high; 129 int search_low; 130 131 /* Information on the current probe. */ 132 int probe_size; 133 134 u32 probe_timestamp; 135 } icsk_mtup; 136 u32 icsk_user_timeout; 137 138 u64 icsk_ca_priv[104 / sizeof(u64)]; 139 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64)) 140 }; 141 142 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 143 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 144 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 145 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 146 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 147 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 148 149 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 150 { 151 return (struct inet_connection_sock *)sk; 152 } 153 154 static inline void *inet_csk_ca(const struct sock *sk) 155 { 156 return (void *)inet_csk(sk)->icsk_ca_priv; 157 } 158 159 struct sock *inet_csk_clone_lock(const struct sock *sk, 160 const struct request_sock *req, 161 const gfp_t priority); 162 163 enum inet_csk_ack_state_t { 164 ICSK_ACK_SCHED = 1, 165 ICSK_ACK_TIMER = 2, 166 ICSK_ACK_PUSHED = 4, 167 ICSK_ACK_PUSHED2 = 8, 168 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 169 }; 170 171 void inet_csk_init_xmit_timers(struct sock *sk, 172 void (*retransmit_handler)(struct timer_list *), 173 void (*delack_handler)(struct timer_list *), 174 void (*keepalive_handler)(struct timer_list *)); 175 void inet_csk_clear_xmit_timers(struct sock *sk); 176 177 static inline void inet_csk_schedule_ack(struct sock *sk) 178 { 179 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 180 } 181 182 static inline int inet_csk_ack_scheduled(const struct sock *sk) 183 { 184 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 185 } 186 187 static inline void inet_csk_delack_init(struct sock *sk) 188 { 189 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 190 } 191 192 void inet_csk_delete_keepalive_timer(struct sock *sk); 193 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 194 195 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 196 { 197 struct inet_connection_sock *icsk = inet_csk(sk); 198 199 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 200 icsk->icsk_pending = 0; 201 #ifdef INET_CSK_CLEAR_TIMERS 202 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 203 #endif 204 } else if (what == ICSK_TIME_DACK) { 205 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 206 #ifdef INET_CSK_CLEAR_TIMERS 207 sk_stop_timer(sk, &icsk->icsk_delack_timer); 208 #endif 209 } else { 210 pr_debug("inet_csk BUG: unknown timer value\n"); 211 } 212 } 213 214 /* 215 * Reset the retransmission timer 216 */ 217 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 218 unsigned long when, 219 const unsigned long max_when) 220 { 221 struct inet_connection_sock *icsk = inet_csk(sk); 222 223 if (when > max_when) { 224 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 225 sk, what, when, (void *)_THIS_IP_); 226 when = max_when; 227 } 228 229 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 230 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE || 231 what == ICSK_TIME_REO_TIMEOUT) { 232 icsk->icsk_pending = what; 233 icsk->icsk_timeout = jiffies + when; 234 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 235 } else if (what == ICSK_TIME_DACK) { 236 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 237 icsk->icsk_ack.timeout = jiffies + when; 238 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 239 } else { 240 pr_debug("inet_csk BUG: unknown timer value\n"); 241 } 242 } 243 244 static inline unsigned long 245 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 246 unsigned long max_when) 247 { 248 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 249 250 return (unsigned long)min_t(u64, when, max_when); 251 } 252 253 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 254 255 int inet_csk_get_port(struct sock *sk, unsigned short snum); 256 257 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 258 const struct request_sock *req); 259 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 260 struct sock *newsk, 261 const struct request_sock *req); 262 263 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 264 struct request_sock *req, 265 struct sock *child); 266 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 267 unsigned long timeout); 268 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 269 struct request_sock *req, 270 bool own_req); 271 272 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 273 { 274 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 275 } 276 277 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 278 { 279 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 280 } 281 282 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 283 { 284 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 285 } 286 287 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 288 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 289 290 void inet_csk_destroy_sock(struct sock *sk); 291 void inet_csk_prepare_forced_close(struct sock *sk); 292 293 /* 294 * LISTEN is a special case for poll.. 295 */ 296 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 297 { 298 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 299 (EPOLLIN | EPOLLRDNORM) : 0; 300 } 301 302 int inet_csk_listen_start(struct sock *sk, int backlog); 303 void inet_csk_listen_stop(struct sock *sk); 304 305 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 306 307 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname, 308 char __user *optval, int __user *optlen); 309 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname, 310 char __user *optval, unsigned int optlen); 311 312 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 313 314 #define TCP_PINGPONG_THRESH 3 315 316 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 317 { 318 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; 319 } 320 321 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 322 { 323 inet_csk(sk)->icsk_ack.pingpong = 0; 324 } 325 326 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 327 { 328 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 329 } 330 331 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 332 { 333 struct inet_connection_sock *icsk = inet_csk(sk); 334 335 if (icsk->icsk_ack.pingpong < U8_MAX) 336 icsk->icsk_ack.pingpong++; 337 } 338 #endif /* _INET_CONNECTION_SOCK_H */ 339