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#if defined(CONFIG_TCP_NATA_URC) || defined(CONFIG_TCP_NATA_STL) 24#include <net/nata.h> 25#include <net/inet_connection_nata.h> 26#endif 27 28/* Cancel timers, when they are not required. */ 29#undef INET_CSK_CLEAR_TIMERS 30 31struct inet_bind_bucket; 32struct tcp_congestion_ops; 33 34/* 35 * Pointers to address related TCP functions 36 * (i.e. things that depend on the address family) 37 */ 38struct 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 sockptr_t optval, unsigned int optlen); 54 int (*getsockopt)(struct sock *sk, int level, int optname, 55 char __user *optval, int __user *optlen); 56 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *); 57 void (*mtu_reduced)(struct sock *sk); 58}; 59 60/** inet_connection_sock - INET connection oriented sock 61 * 62 * @icsk_accept_queue: FIFO of established children 63 * @icsk_bind_hash: Bind node 64 * @icsk_timeout: Timeout 65 * @icsk_retransmit_timer: Resend (no ack) 66 * @icsk_rto: Retransmit timeout 67 * @icsk_pmtu_cookie Last pmtu seen by socket 68 * @icsk_ca_ops Pluggable congestion control hook 69 * @icsk_af_ops Operations which are AF_INET{4,6} specific 70 * @icsk_ulp_ops Pluggable ULP control hook 71 * @icsk_ulp_data ULP private data 72 * @icsk_clean_acked Clean acked data hook 73 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable 74 * @icsk_ca_state: Congestion control state 75 * @icsk_retransmits: Number of unrecovered [RTO] timeouts 76 * @icsk_pending: Scheduled timer event 77 * @icsk_backoff: Backoff 78 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries 79 * @icsk_probes_out: unanswered 0 window probes 80 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) 81 * @icsk_ack: Delayed ACK control data 82 * @icsk_mtup; MTU probing control data 83 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) 84 * @icsk_user_timeout: TCP_USER_TIMEOUT value 85 */ 86struct inet_connection_sock { 87 /* inet_sock has to be the first member! */ 88 struct inet_sock icsk_inet; 89 struct request_sock_queue icsk_accept_queue; 90 struct inet_bind_bucket *icsk_bind_hash; 91 unsigned long icsk_timeout; 92 struct timer_list icsk_retransmit_timer; 93 struct timer_list icsk_delack_timer; 94 __u32 icsk_rto; 95 __u32 icsk_rto_min; 96 __u32 icsk_delack_max; 97 __u32 icsk_pmtu_cookie; 98 const struct tcp_congestion_ops *icsk_ca_ops; 99 const struct inet_connection_sock_af_ops *icsk_af_ops; 100 const struct tcp_ulp_ops *icsk_ulp_ops; 101 void __rcu *icsk_ulp_data; 102 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); 103 struct hlist_node icsk_listen_portaddr_node; 104 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); 105 __u8 icsk_ca_state:5, 106 icsk_ca_initialized:1, 107 icsk_ca_setsockopt:1, 108 icsk_ca_dst_locked:1; 109 __u8 icsk_retransmits; 110 __u8 icsk_pending; 111 __u8 icsk_backoff; 112 __u8 icsk_syn_retries; 113 __u8 icsk_probes_out; 114 __u16 icsk_ext_hdr_len; 115#if defined(CONFIG_TCP_NATA_URC) || defined(CONFIG_TCP_NATA_STL) 116 __u8 nata_retries_enabled:1, 117 nata_reserved:7; 118 __u8 nata_data_retries; 119 __u8 nata_retries_type; 120 __u32 nata_syn_rto; 121 __u32 nata_data_rto; 122#endif 123 struct { 124 __u8 pending; /* ACK is pending */ 125 __u8 quick; /* Scheduled number of quick acks */ 126 __u8 pingpong; /* The session is interactive */ 127 __u8 retry; /* Number of attempts */ 128 __u32 ato; /* Predicted tick of soft clock */ 129 unsigned long timeout; /* Currently scheduled timeout */ 130 __u32 lrcvtime; /* timestamp of last received data packet */ 131 __u16 last_seg_size; /* Size of last incoming segment */ 132 __u16 rcv_mss; /* MSS used for delayed ACK decisions */ 133 } icsk_ack; 134 struct { 135 int enabled; 136 137 /* Range of MTUs to search */ 138 int search_high; 139 int search_low; 140 141 /* Information on the current probe. */ 142 int probe_size; 143 144 u32 probe_timestamp; 145 } icsk_mtup; 146 u32 icsk_probes_tstamp; 147 u32 icsk_user_timeout; 148 149 u64 icsk_ca_priv[104 / sizeof(u64)]; 150#define ICSK_CA_PRIV_SIZE (13 * sizeof(u64)) 151}; 152 153#define ICSK_TIME_RETRANS 1 /* Retransmit timer */ 154#define ICSK_TIME_DACK 2 /* Delayed ack timer */ 155#define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ 156#define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */ 157#define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ 158#define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ 159 160static inline struct inet_connection_sock *inet_csk(const struct sock *sk) 161{ 162 return (struct inet_connection_sock *)sk; 163} 164 165static inline void *inet_csk_ca(const struct sock *sk) 166{ 167 return (void *)inet_csk(sk)->icsk_ca_priv; 168} 169 170struct sock *inet_csk_clone_lock(const struct sock *sk, 171 const struct request_sock *req, 172 const gfp_t priority); 173 174enum inet_csk_ack_state_t { 175 ICSK_ACK_SCHED = 1, 176 ICSK_ACK_TIMER = 2, 177 ICSK_ACK_PUSHED = 4, 178 ICSK_ACK_PUSHED2 = 8, 179 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ 180}; 181 182void inet_csk_init_xmit_timers(struct sock *sk, 183 void (*retransmit_handler)(struct timer_list *), 184 void (*delack_handler)(struct timer_list *), 185 void (*keepalive_handler)(struct timer_list *)); 186void inet_csk_clear_xmit_timers(struct sock *sk); 187void inet_csk_clear_xmit_timers_sync(struct sock *sk); 188 189static inline void inet_csk_schedule_ack(struct sock *sk) 190{ 191 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; 192} 193 194static inline int inet_csk_ack_scheduled(const struct sock *sk) 195{ 196 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; 197} 198 199static inline void inet_csk_delack_init(struct sock *sk) 200{ 201 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); 202} 203 204void inet_csk_delete_keepalive_timer(struct sock *sk); 205void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 206 207static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) 208{ 209 struct inet_connection_sock *icsk = inet_csk(sk); 210 211 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { 212 icsk->icsk_pending = 0; 213#ifdef INET_CSK_CLEAR_TIMERS 214 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 215#endif 216 } else if (what == ICSK_TIME_DACK) { 217 icsk->icsk_ack.pending = 0; 218 icsk->icsk_ack.retry = 0; 219#ifdef INET_CSK_CLEAR_TIMERS 220 sk_stop_timer(sk, &icsk->icsk_delack_timer); 221#endif 222 } else { 223 pr_debug("inet_csk BUG: unknown timer value\n"); 224 } 225} 226 227#if defined(CONFIG_TCP_NATA_URC) || defined(CONFIG_TCP_NATA_STL) 228static inline unsigned long get_nata_rto(struct sock *sk, 229 struct inet_connection_sock *icsk, 230 unsigned long when, const int what) 231{ 232 unsigned long when_nata; 233 unsigned long shift; 234 235 if (!icsk->nata_retries_enabled) 236 return when; 237 238 switch (what) { 239 case ICSK_TIME_RETRANS: 240 case ICSK_TIME_EARLY_RETRANS: 241 case ICSK_TIME_LOSS_PROBE: 242 case ICSK_TIME_REO_TIMEOUT: 243 break; 244 default: 245 return when; 246 } 247 248 if (icsk->nata_retries_type == NATA_STL) 249 return sk->sk_state == TCP_SYN_SENT ? 250 icsk->nata_syn_rto : icsk->nata_data_rto; 251 252 if (!nata_thin_stream_check(sk)) 253 return when; 254 255 when_nata = icsk->nata_data_rto; 256 if (icsk->icsk_retransmits > icsk->nata_data_retries) { 257 shift = icsk->icsk_retransmits - icsk->nata_data_retries; 258 if (shift > MAX_SHIFT) { 259 when_nata = NATA_RTO_MAX; 260 } else { 261 when_nata <<= shift; 262 } 263 } 264 return min(when, when_nata); 265} 266#endif 267 268/* 269 * Reset the retransmission timer 270 */ 271static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, 272 unsigned long when, 273 const unsigned long max_when) 274{ 275 struct inet_connection_sock *icsk = inet_csk(sk); 276 277#if defined(CONFIG_TCP_NATA_URC) || defined(CONFIG_TCP_NATA_STL) 278 when = get_nata_rto(sk, icsk, when, what); 279#endif 280 281 if (when > max_when) { 282 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n", 283 sk, what, when, (void *)_THIS_IP_); 284 when = max_when; 285 } 286 287 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || 288 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE || 289 what == ICSK_TIME_REO_TIMEOUT) { 290 icsk->icsk_pending = what; 291 icsk->icsk_timeout = jiffies + when; 292 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); 293 } else if (what == ICSK_TIME_DACK) { 294 icsk->icsk_ack.pending |= ICSK_ACK_TIMER; 295 icsk->icsk_ack.timeout = jiffies + when; 296 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); 297 } else { 298 pr_debug("inet_csk BUG: unknown timer value\n"); 299 } 300} 301 302static inline unsigned long 303inet_csk_rto_backoff(const struct inet_connection_sock *icsk, 304 unsigned long max_when) 305{ 306 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; 307 308 return (unsigned long)min_t(u64, when, max_when); 309} 310 311struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); 312 313int inet_csk_get_port(struct sock *sk, unsigned short snum); 314 315struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, 316 const struct request_sock *req); 317struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 318 struct sock *newsk, 319 const struct request_sock *req); 320 321struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 322 struct request_sock *req, 323 struct sock *child); 324void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 325 unsigned long timeout); 326struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 327 struct request_sock *req, 328 bool own_req); 329 330static inline void inet_csk_reqsk_queue_added(struct sock *sk) 331{ 332 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); 333} 334 335static inline int inet_csk_reqsk_queue_len(const struct sock *sk) 336{ 337 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); 338} 339 340static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 341{ 342 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; 343} 344 345bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); 346void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); 347 348static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) 349{ 350 /* The below has to be done to allow calling inet_csk_destroy_sock */ 351 sock_set_flag(sk, SOCK_DEAD); 352 this_cpu_inc(*sk->sk_prot->orphan_count); 353} 354 355void inet_csk_destroy_sock(struct sock *sk); 356void inet_csk_prepare_forced_close(struct sock *sk); 357 358/* 359 * LISTEN is a special case for poll.. 360 */ 361static inline __poll_t inet_csk_listen_poll(const struct sock *sk) 362{ 363 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? 364 (EPOLLIN | EPOLLRDNORM) : 0; 365} 366 367int inet_csk_listen_start(struct sock *sk, int backlog); 368void inet_csk_listen_stop(struct sock *sk); 369 370void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); 371 372/* update the fast reuse flag when adding a socket */ 373void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 374 struct sock *sk); 375 376struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); 377 378#define TCP_PINGPONG_THRESH 1 379 380static inline void inet_csk_enter_pingpong_mode(struct sock *sk) 381{ 382 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; 383} 384 385static inline void inet_csk_exit_pingpong_mode(struct sock *sk) 386{ 387 inet_csk(sk)->icsk_ack.pingpong = 0; 388} 389 390static inline bool inet_csk_in_pingpong_mode(struct sock *sk) 391{ 392 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 393} 394 395static inline bool inet_csk_has_ulp(struct sock *sk) 396{ 397 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops; 398} 399 400static inline void inet_init_csk_locks(struct sock *sk) 401{ 402 struct inet_connection_sock *icsk = inet_csk(sk); 403 404 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock); 405 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock); 406} 407 408#endif /* _INET_CONNECTION_SOCK_H */ 409