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 #include <linux/sockptr.h> 20 21 #include <net/inet_sock.h> 22 #include <net/request_sock.h> 23 24 /* Cancel timers, when they are not required. */ 25 #undef INET_CSK_CLEAR_TIMERS 26 27 struct inet_bind_bucket; 28 struct tcp_congestion_ops; 29 30 /* 31 * Pointers to address related TCP functions 32 * (i.e. things that depend on the address family) 33 */ 34 struct inet_connection_sock_af_ops { 35 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 36 void (*send_check)(struct sock *sk, struct sk_buff *skb); 37 int (*rebuild_header)(struct sock *sk); 38 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb); 39 int (*conn_request)(struct sock *sk, struct sk_buff *skb); 40 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb, 41 struct request_sock *req, 42 struct dst_entry *dst, 43 struct request_sock *req_unhash, 44 bool *own_req); 45 u16 net_header_len; 46 u16 net_frag_header_len; 47 u16 sockaddr_len; 48 int (*setsockopt)(struct sock *sk, int level, int optname, 49 sockptr_t optval, unsigned int optlen); 50 int (*getsockopt)(struct sock *sk, int level, int optname, 51 char __user *optval, int __user *optlen); 52 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 53 void (*mtu_reduced)(struct sock *sk); 54 }; 55 56 /** inet_connection_sock - INET connection oriented sock 57 * 58 * @icsk_accept_queue: FIFO of established children 59 * @icsk_bind_hash: Bind node 60 * @icsk_timeout: Timeout 61 * @icsk_retransmit_timer: Resend (no ack) 62 * @icsk_rto: Retransmit timeout 63 * @icsk_pmtu_cookie Last pmtu seen by socket 64 * @icsk_ca_ops Pluggable congestion control hook 65 * @icsk_af_ops Operations which are AF_INET{4,6} specific 66 * @icsk_ulp_ops Pluggable ULP control hook 67 * @icsk_ulp_data ULP private data 68 * @icsk_clean_acked Clean acked data hook 69 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable 70 * @icsk_ca_state: Congestion control state 71 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 72 * @icsk_pending: Scheduled timer event 73 * @icsk_backoff: Backoff 74 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 75 * @icsk_probes_out: unanswered 0 window probes 76 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 77 * @icsk_ack: Delayed ACK control data 78 * @icsk_mtup; MTU probing control data 79 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 80 * @icsk_user_timeout: TCP_USER_TIMEOUT value 81 */ 82 struct inet_connection_sock { 83 /* inet_sock has to be the first member! */ 84 struct inet_sock icsk_inet; 85 struct request_sock_queue icsk_accept_queue; 86 struct inet_bind_bucket *icsk_bind_hash; 87 unsigned long icsk_timeout; 88 struct timer_list icsk_retransmit_timer; 89 struct timer_list icsk_delack_timer; 90 __u32 icsk_rto; 91 __u32 icsk_rto_min; 92 __u32 icsk_delack_max; 93 __u32 icsk_pmtu_cookie; 94 const struct tcp_congestion_ops *icsk_ca_ops; 95 const struct inet_connection_sock_af_ops *icsk_af_ops; 96 const struct tcp_ulp_ops *icsk_ulp_ops; 97 void __rcu *icsk_ulp_data; 98 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 99 struct hlist_node icsk_listen_portaddr_node; 100 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 101 __u8 icsk_ca_state:5, 102 icsk_ca_initialized:1, 103 icsk_ca_setsockopt:1, 104 icsk_ca_dst_locked:1; 105 __u8 icsk_retransmits; 106 __u8 icsk_pending; 107 __u8 icsk_backoff; 108 __u8 icsk_syn_retries; 109 __u8 icsk_probes_out; 110 __u16 icsk_ext_hdr_len; 111 struct { 112 __u8 pending; /* ACK is pending */ 113 __u8 quick; /* Scheduled number of quick acks */ 114 __u8 pingpong; /* The session is interactive */ 115 __u8 retry; /* Number of attempts */ 116 __u32 ato; /* Predicted tick of soft clock */ 117 unsigned long timeout; /* Currently scheduled timeout */ 118 __u32 lrcvtime; /* timestamp of last received data packet */ 119 __u16 last_seg_size; /* Size of last incoming segment */ 120 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 121 } icsk_ack; 122 struct { 123 /* Range of MTUs to search */ 124 int search_high; 125 int search_low; 126 127 /* Information on the current probe. */ 128 u32 probe_size:31, 129 /* Is the MTUP feature enabled for this connection? */ 130 enabled:1; 131 132 u32 probe_timestamp; 133 } icsk_mtup; 134 u32 icsk_probes_tstamp; 135 u32 icsk_user_timeout; 136 137 u64 icsk_ca_priv[104 / sizeof(u64)]; 138 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) 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_LOSS_PROBE 5 /* Tail loss probe timer */ 145 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering 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 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 167 }; 168 169 void inet_csk_init_xmit_timers(struct sock *sk, 170 void (*retransmit_handler)(struct timer_list *), 171 void (*delack_handler)(struct timer_list *), 172 void (*keepalive_handler)(struct timer_list *)); 173 void inet_csk_clear_xmit_timers(struct sock *sk); 174 175 static inline void inet_csk_schedule_ack(struct sock *sk) 176 { 177 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 178 } 179 180 static inline int inet_csk_ack_scheduled(const struct sock *sk) 181 { 182 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 183 } 184 185 static inline void inet_csk_delack_init(struct sock *sk) 186 { 187 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 188 } 189 190 void inet_csk_delete_keepalive_timer(struct sock *sk); 191 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 192 193 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 194 { 195 struct inet_connection_sock *icsk = inet_csk(sk); 196 197 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 198 icsk->icsk_pending = 0; 199 #ifdef INET_CSK_CLEAR_TIMERS 200 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 201 #endif 202 } else if (what == ICSK_TIME_DACK) { 203 icsk->icsk_ack.pending = 0; 204 icsk->icsk_ack.retry = 0; 205 #ifdef INET_CSK_CLEAR_TIMERS 206 sk_stop_timer(sk, &icsk->icsk_delack_timer); 207 #endif 208 } else { 209 pr_debug("inet_csk BUG: unknown timer value\n"); 210 } 211 } 212 213 /* 214 * Reset the retransmission timer 215 */ 216 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 217 unsigned long when, 218 const unsigned long max_when) 219 { 220 struct inet_connection_sock *icsk = inet_csk(sk); 221 222 if (when > max_when) { 223 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 224 sk, what, when, (void *)_THIS_IP_); 225 when = max_when; 226 } 227 228 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 229 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { 230 icsk->icsk_pending = what; 231 icsk->icsk_timeout = jiffies + when; 232 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 233 } else if (what == ICSK_TIME_DACK) { 234 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 235 icsk->icsk_ack.timeout = jiffies + when; 236 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 237 } else { 238 pr_debug("inet_csk BUG: unknown timer value\n"); 239 } 240 } 241 242 static inline unsigned long 243 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 244 unsigned long max_when) 245 { 246 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 247 248 return (unsigned long)min_t(u64, when, max_when); 249 } 250 251 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 252 253 int inet_csk_get_port(struct sock *sk, unsigned short snum); 254 255 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 256 const struct request_sock *req); 257 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 258 struct sock *newsk, 259 const struct request_sock *req); 260 261 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 262 struct request_sock *req, 263 struct sock *child); 264 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 265 unsigned long timeout); 266 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 267 struct request_sock *req, 268 bool own_req); 269 270 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 271 { 272 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 273 } 274 275 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 276 { 277 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 278 } 279 280 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 281 { 282 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 283 } 284 285 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 286 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 287 288 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 289 { 290 /* The below has to be done to allow calling inet_csk_destroy_sock */ 291 sock_set_flag(sk, SOCK_DEAD); 292 percpu_counter_inc(sk->sk_prot->orphan_count); 293 } 294 295 void inet_csk_destroy_sock(struct sock *sk); 296 void inet_csk_prepare_forced_close(struct sock *sk); 297 298 /* 299 * LISTEN is a special case for poll.. 300 */ 301 static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 302 { 303 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 304 (EPOLLIN | EPOLLRDNORM) : 0; 305 } 306 307 int inet_csk_listen_start(struct sock *sk, int backlog); 308 void inet_csk_listen_stop(struct sock *sk); 309 310 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 311 312 /* update the fast reuse flag when adding a socket */ 313 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 314 struct sock *sk); 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 } 342 343 static inline bool inet_csk_has_ulp(struct sock *sk) 344 { 345 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops; 346 } 347 348 #endif /* _INET_CONNECTION_SOCK_H */ 349