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 */ 80 struct inet_connection_sock { 81 /* inet_sock has to be the first member! */ 82 struct inet_sock icsk_inet; 83 struct request_sock_queue icsk_accept_queue; 84 struct inet_bind_bucket *icsk_bind_hash; 85 unsigned long icsk_timeout; 86 struct timer_list icsk_retransmit_timer; 87 struct timer_list icsk_delack_timer; 88 __u32 icsk_rto; 89 __u32 icsk_pmtu_cookie; 90 const struct tcp_congestion_ops *icsk_ca_ops; 91 const struct inet_connection_sock_af_ops *icsk_af_ops; 92 const struct tcp_ulp_ops *icsk_ulp_ops; 93 void __rcu *icsk_ulp_data; 94 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 95 struct hlist_node icsk_listen_portaddr_node; 96 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 97 __u8 icsk_ca_state:6, 98 icsk_ca_setsockopt:1, 99 icsk_ca_dst_locked:1; 100 __u8 icsk_retransmits; 101 __u8 icsk_pending; 102 __u8 icsk_backoff; 103 __u8 icsk_syn_retries; 104 __u8 icsk_probes_out; 105 __u16 icsk_ext_hdr_len; 106 struct { 107 __u8 pending; /* ACK is pending */ 108 __u8 quick; /* Scheduled number of quick acks */ 109 __u8 pingpong; /* The session is interactive */ 110 __u8 blocked; /* Delayed ACK was blocked by socket lock */ 111 __u32 ato; /* Predicted tick of soft clock */ 112 unsigned long timeout; /* Currently scheduled timeout */ 113 __u32 lrcvtime; /* timestamp of last received data packet */ 114 __u16 last_seg_size; /* Size of last incoming segment */ 115 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 116 } icsk_ack; 117 struct { 118 int enabled; 119 120 /* Range of MTUs to search */ 121 int search_high; 122 int search_low; 123 124 /* Information on the current probe. */ 125 int probe_size; 126 127 u32 probe_timestamp; 128 } icsk_mtup; 129 u32 icsk_user_timeout; 130 131 u64 icsk_ca_priv[104 / sizeof(u64)]; 132 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64)) 133 }; 134 135 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 136 #define ICSK_TIME_DACK 2 /* Delayed ack timer */ 137 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 138 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 139 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 140 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 141 142 static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 143 { 144 return (struct inet_connection_sock *)sk; 145 } 146 147 static inline void *inet_csk_ca(const struct sock *sk) 148 { 149 return (void *)inet_csk(sk)->icsk_ca_priv; 150 } 151 152 struct sock *inet_csk_clone_lock(const struct sock *sk, 153 const struct request_sock *req, 154 const gfp_t priority); 155 156 enum inet_csk_ack_state_t { 157 ICSK_ACK_SCHED = 1, 158 ICSK_ACK_TIMER = 2, 159 ICSK_ACK_PUSHED = 4, 160 ICSK_ACK_PUSHED2 = 8, 161 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 162 }; 163 164 void inet_csk_init_xmit_timers(struct sock *sk, 165 void (*retransmit_handler)(struct timer_list *), 166 void (*delack_handler)(struct timer_list *), 167 void (*keepalive_handler)(struct timer_list *)); 168 void inet_csk_clear_xmit_timers(struct sock *sk); 169 170 static inline void inet_csk_schedule_ack(struct sock *sk) 171 { 172 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 173 } 174 175 static inline int inet_csk_ack_scheduled(const struct sock *sk) 176 { 177 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 178 } 179 180 static inline void inet_csk_delack_init(struct sock *sk) 181 { 182 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 183 } 184 185 void inet_csk_delete_keepalive_timer(struct sock *sk); 186 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 187 188 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 189 { 190 struct inet_connection_sock *icsk = inet_csk(sk); 191 192 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 193 icsk->icsk_pending = 0; 194 #ifdef INET_CSK_CLEAR_TIMERS 195 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 196 #endif 197 } else if (what == ICSK_TIME_DACK) { 198 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0; 199 #ifdef INET_CSK_CLEAR_TIMERS 200 sk_stop_timer(sk, &icsk->icsk_delack_timer); 201 #endif 202 } else { 203 pr_debug("inet_csk BUG: unknown timer value\n"); 204 } 205 } 206 207 /* 208 * Reset the retransmission timer 209 */ 210 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 211 unsigned long when, 212 const unsigned long max_when) 213 { 214 struct inet_connection_sock *icsk = inet_csk(sk); 215 216 if (when > max_when) { 217 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 218 sk, what, when, (void *)_THIS_IP_); 219 when = max_when; 220 } 221 222 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 223 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE || 224 what == ICSK_TIME_REO_TIMEOUT) { 225 icsk->icsk_pending = what; 226 icsk->icsk_timeout = jiffies + when; 227 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 228 } else if (what == ICSK_TIME_DACK) { 229 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 230 icsk->icsk_ack.timeout = jiffies + when; 231 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 232 } else { 233 pr_debug("inet_csk BUG: unknown timer value\n"); 234 } 235 } 236 237 static inline unsigned long 238 inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 239 unsigned long max_when) 240 { 241 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 242 243 return (unsigned long)min_t(u64, when, max_when); 244 } 245 246 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 247 248 int inet_csk_get_port(struct sock *sk, unsigned short snum); 249 250 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 251 const struct request_sock *req); 252 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 253 struct sock *newsk, 254 const struct request_sock *req); 255 256 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 257 struct request_sock *req, 258 struct sock *child); 259 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 260 unsigned long timeout); 261 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 262 struct request_sock *req, 263 bool own_req); 264 265 static inline void inet_csk_reqsk_queue_added(struct sock *sk) 266 { 267 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 268 } 269 270 static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 271 { 272 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 273 } 274 275 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 276 { 277 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 278 } 279 280 void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 281 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 282 283 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 284 { 285 /* The below has to be done to allow calling inet_csk_destroy_sock */ 286 sock_set_flag(sk, SOCK_DEAD); 287 percpu_counter_inc(sk->sk_prot->orphan_count); 288 } 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 /* update the fast reuse flag when adding a socket */ 308 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 309 struct sock *sk); 310 311 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 312 313 #define TCP_PINGPONG_THRESH 3 314 315 static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 316 { 317 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; 318 } 319 320 static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 321 { 322 inet_csk(sk)->icsk_ack.pingpong = 0; 323 } 324 325 static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 326 { 327 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 328 } 329 330 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) 331 { 332 struct inet_connection_sock *icsk = inet_csk(sk); 333 334 if (icsk->icsk_ack.pingpong < U8_MAX) 335 icsk->icsk_ack.pingpong++; 336 } 337 338 static inline bool inet_csk_has_ulp(struct sock *sk) 339 { 340 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops; 341 } 342 343 #endif /* _INET_CONNECTION_SOCK_H */ 344