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
31 struct inet_bind_bucket;
32 struct tcp_congestion_ops;
33
34 /*
35 * Pointers to address related TCP functions
36 * (i.e. things that depend on the address family)
37 */
38 struct 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 */
86 struct 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
inet_csk(const struct sock *sk)160 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
161 {
162 return (struct inet_connection_sock *)sk;
163 }
164
inet_csk_ca(const struct sock *sk)165 static inline void *inet_csk_ca(const struct sock *sk)
166 {
167 return (void *)inet_csk(sk)->icsk_ca_priv;
168 }
169
170 struct sock *inet_csk_clone_lock(const struct sock *sk,
171 const struct request_sock *req,
172 const gfp_t priority);
173
174 enum 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
182 void 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 *));
186 void inet_csk_clear_xmit_timers(struct sock *sk);
187 void inet_csk_clear_xmit_timers_sync(struct sock *sk);
188
inet_csk_schedule_ack(struct sock *sk)189 static inline void inet_csk_schedule_ack(struct sock *sk)
190 {
191 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
192 }
193
inet_csk_ack_scheduled(const struct sock *sk)194 static inline int inet_csk_ack_scheduled(const struct sock *sk)
195 {
196 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
197 }
198
inet_csk_delack_init(struct sock *sk)199 static 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
204 void inet_csk_delete_keepalive_timer(struct sock *sk);
205 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
206
inet_csk_clear_xmit_timer(struct sock *sk, const int what)207 static 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)
get_nata_rto(struct sock *sk, struct inet_connection_sock *icsk, unsigned long when, const int what)228 static 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 */
inet_csk_reset_xmit_timer(struct sock *sk, const int what, unsigned long when, const unsigned long max_when)271 static 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
302 static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock *icsk, unsigned long max_when)303 inet_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
311 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
312
313 int inet_csk_get_port(struct sock *sk, unsigned short snum);
314
315 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
316 const struct request_sock *req);
317 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
318 struct sock *newsk,
319 const struct request_sock *req);
320
321 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
322 struct request_sock *req,
323 struct sock *child);
324 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
325 unsigned long timeout);
326 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
327 struct request_sock *req,
328 bool own_req);
329
inet_csk_reqsk_queue_added(struct sock *sk)330 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
331 {
332 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
333 }
334
inet_csk_reqsk_queue_len(const struct sock *sk)335 static 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
inet_csk_reqsk_queue_is_full(const struct sock *sk)340 static 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
345 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
346 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
347
inet_csk_prepare_for_destroy_sock(struct sock *sk)348 static 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
355 void inet_csk_destroy_sock(struct sock *sk);
356 void inet_csk_prepare_forced_close(struct sock *sk);
357
358 /*
359 * LISTEN is a special case for poll..
360 */
inet_csk_listen_poll(const struct sock *sk)361 static 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
367 int inet_csk_listen_start(struct sock *sk, int backlog);
368 void inet_csk_listen_stop(struct sock *sk);
369
370 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
371
372 /* update the fast reuse flag when adding a socket */
373 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
374 struct sock *sk);
375
376 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
377
378 #define TCP_PINGPONG_THRESH 1
379
inet_csk_enter_pingpong_mode(struct sock *sk)380 static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
381 {
382 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
383 }
384
inet_csk_exit_pingpong_mode(struct sock *sk)385 static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
386 {
387 inet_csk(sk)->icsk_ack.pingpong = 0;
388 }
389
inet_csk_in_pingpong_mode(struct sock *sk)390 static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
391 {
392 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
393 }
394
inet_csk_has_ulp(struct sock *sk)395 static 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
inet_init_csk_locks(struct sock *sk)400 static 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