1/*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24
25/*! \defgroup timeout Connection timeouts
26
27 APIs related to setting connection timeouts
28*/
29//@{
30
31/*
32 * NOTE: These public enums are part of the abi. If you want to add one,
33 * add it at where specified so existing users are unaffected.
34 */
35enum pending_timeout {
36 NO_PENDING_TIMEOUT = 0,
37 PENDING_TIMEOUT_AWAITING_PROXY_RESPONSE = 1,
38 PENDING_TIMEOUT_AWAITING_CONNECT_RESPONSE = 2,
39 PENDING_TIMEOUT_ESTABLISH_WITH_SERVER = 3,
40 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE = 4,
41 PENDING_TIMEOUT_AWAITING_PING = 5,
42 PENDING_TIMEOUT_CLOSE_ACK = 6,
43 PENDING_TIMEOUT_UNUSED1 = 7,
44 PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE = 8,
45 PENDING_TIMEOUT_SSL_ACCEPT = 9,
46 PENDING_TIMEOUT_HTTP_CONTENT = 10,
47 PENDING_TIMEOUT_AWAITING_CLIENT_HS_SEND = 11,
48 PENDING_FLUSH_STORED_SEND_BEFORE_CLOSE = 12,
49 PENDING_TIMEOUT_SHUTDOWN_FLUSH = 13,
50 PENDING_TIMEOUT_CGI = 14,
51 PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE = 15,
52 PENDING_TIMEOUT_WS_PONG_CHECK_SEND_PING = 16,
53 PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG = 17,
54 PENDING_TIMEOUT_CLIENT_ISSUE_PAYLOAD = 18,
55 PENDING_TIMEOUT_AWAITING_SOCKS_GREETING_REPLY = 19,
56 PENDING_TIMEOUT_AWAITING_SOCKS_CONNECT_REPLY = 20,
57 PENDING_TIMEOUT_AWAITING_SOCKS_AUTH_REPLY = 21,
58 PENDING_TIMEOUT_KILLED_BY_SSL_INFO = 22,
59 PENDING_TIMEOUT_KILLED_BY_PARENT = 23,
60 PENDING_TIMEOUT_CLOSE_SEND = 24,
61 PENDING_TIMEOUT_HOLDING_AH = 25,
62 PENDING_TIMEOUT_UDP_IDLE = 26,
63 PENDING_TIMEOUT_CLIENT_CONN_IDLE = 27,
64 PENDING_TIMEOUT_LAGGING = 28,
65 PENDING_TIMEOUT_THREADPOOL = 29,
66 PENDING_TIMEOUT_THREADPOOL_TASK = 30,
67 PENDING_TIMEOUT_KILLED_BY_PROXY_CLIENT_CLOSE = 31,
68 PENDING_TIMEOUT_USER_OK = 32,
69
70 /****** add new things just above ---^ ******/
71
72 PENDING_TIMEOUT_USER_REASON_BASE = 1000
73};
74
75#define lws_time_in_microseconds lws_now_usecs
76
77#define LWS_TO_KILL_ASYNC -1
78/**< If LWS_TO_KILL_ASYNC is given as the timeout sec in a lws_set_timeout()
79 * call, then the connection is marked to be killed at the next timeout
80 * check. This is how you should force-close the wsi being serviced if
81 * you are doing it outside the callback (where you should close by nonzero
82 * return).
83 */
84#define LWS_TO_KILL_SYNC -2
85/**< If LWS_TO_KILL_SYNC is given as the timeout sec in a lws_set_timeout()
86 * call, then the connection is closed before returning (which may delete
87 * the wsi). This should only be used where the wsi being closed is not the
88 * wsi currently being serviced.
89 */
90/**
91 * lws_set_timeout() - marks the wsi as subject to a timeout some seconds hence
92 *
93 * \param wsi: Websocket connection instance
94 * \param reason: timeout reason
95 * \param secs: how many seconds. You may set to LWS_TO_KILL_ASYNC to
96 * force the connection to timeout at the next opportunity, or
97 * LWS_TO_KILL_SYNC to close it synchronously if you know the
98 * wsi is not the one currently being serviced.
99 */
100LWS_VISIBLE LWS_EXTERN void
101lws_set_timeout(struct lws *wsi, enum pending_timeout reason, int secs);
102
103/**
104 * lws_set_timeout_us() - marks the wsi as subject to a timeout some us hence
105 *
106 * \param wsi: Websocket connection instance
107 * \param reason: timeout reason
108 * \param us: 0 removes the timeout, otherwise number of us to wait
109 *
110 * Higher-resolution version of lws_set_timeout(). Actual resolution depends
111 * on platform and load, usually ms.
112 */
113void
114lws_set_timeout_us(struct lws *wsi, enum pending_timeout reason, lws_usec_t us);
115
116/* helper for clearer LWS_TO_KILL_ASYNC / LWS_TO_KILL_SYNC usage */
117#define lws_wsi_close(w, to_kill) lws_set_timeout(w, 1, to_kill)
118
119
120#define LWS_SET_TIMER_USEC_CANCEL ((lws_usec_t)-1ll)
121#define LWS_USEC_PER_SEC ((lws_usec_t)1000000)
122
123/**
124 * lws_set_timer_usecs() - schedules a callback on the wsi in the future
125 *
126 * \param wsi: Websocket connection instance
127 * \param usecs: LWS_SET_TIMER_USEC_CANCEL removes any existing scheduled
128 * callback, otherwise number of microseconds in the future
129 * the callback will occur at.
130 *
131 * NOTE: event loop support for this:
132 *
133 * default poll() loop: yes
134 * libuv event loop: yes
135 * libev: not implemented (patch welcome)
136 * libevent: not implemented (patch welcome)
137 *
138 * After the deadline expires, the wsi will get a callback of type
139 * LWS_CALLBACK_TIMER and the timer is exhausted. The deadline may be
140 * continuously deferred by further calls to lws_set_timer_usecs() with a later
141 * deadline, or cancelled by lws_set_timer_usecs(wsi, -1).
142 *
143 * If the timer should repeat, lws_set_timer_usecs() must be called again from
144 * LWS_CALLBACK_TIMER.
145 *
146 * Accuracy depends on the platform and the load on the event loop or system...
147 * all that's guaranteed is the callback will come after the requested wait
148 * period.
149 */
150LWS_VISIBLE LWS_EXTERN void
151lws_set_timer_usecs(struct lws *wsi, lws_usec_t usecs);
152
153struct lws_sorted_usec_list;
154
155typedef void (*sul_cb_t)(struct lws_sorted_usec_list *sul);
156
157typedef struct lws_sorted_usec_list {
158 struct lws_dll2 list; /* simplify the code by keeping this at start */
159 lws_usec_t us;
160 sul_cb_t cb;
161 uint32_t latency_us; /* us it may safely be delayed */
162} lws_sorted_usec_list_t;
163
164/*
165 * There are multiple sul owners to allow accounting for, a) events that must
166 * wake from suspend, and b) events that can be missued due to suspend
167 */
168#define LWS_COUNT_PT_SUL_OWNERS 2
169
170#define LWSSULLI_MISS_IF_SUSPENDED 0
171#define LWSSULLI_WAKE_IF_SUSPENDED 1
172
173/*
174 * lws_sul2_schedule() - schedule a callback
175 *
176 * \param context: the lws_context
177 * \param tsi: the thread service index (usually 0)
178 * \param flags: LWSSULLI_...
179 * \param sul: pointer to the sul element
180 *
181 * Generic callback-at-a-later time function. The callback happens on the
182 * event loop thread context.
183 *
184 * Although the api has us resultion, the actual resolution depends on the
185 * platform and may be, eg, 1ms.
186 *
187 * This doesn't allocate and doesn't fail.
188 *
189 * If flags contains LWSSULLI_WAKE_IF_SUSPENDED, the scheduled event is placed
190 * on a sul owner list that, if the system has entered low power suspend mode,
191 * tries to arrange that the system should wake from platform suspend just
192 * before the event is due. Scheduled events without this flag will be missed
193 * in the case the system is in suspend and nothing else happens to have woken
194 * it.
195 *
196 * You can call it again with another us value to change the delay or move the
197 * event to a different owner (ie, wake or miss on suspend).
198 */
199LWS_VISIBLE LWS_EXTERN void
200lws_sul2_schedule(struct lws_context *context, int tsi, int flags,
201 lws_sorted_usec_list_t *sul);
202
203/*
204 * lws_sul_cancel() - cancel scheduled callback
205 *
206 * \param sul: pointer to the sul element
207 *
208 * If it's scheduled, remove the sul from its owning sorted list.
209 * If not scheduled, it's a NOP.
210 */
211LWS_VISIBLE LWS_EXTERN void
212lws_sul_cancel(lws_sorted_usec_list_t *sul);
213
214/*
215 * lws_sul_earliest_wakeable_event() - get earliest wake-from-suspend event
216 *
217 * \param ctx: the lws context
218 * \param pearliest: pointer to lws_usec_t to take the result
219 *
220 * Either returns 1 if no pending event, or 0 and sets *pearliest to the
221 * MONOTONIC time of the current earliest next expected event.
222 */
223LWS_VISIBLE LWS_EXTERN int
224lws_sul_earliest_wakeable_event(struct lws_context *ctx, lws_usec_t *pearliest);
225
226/*
227 * For backwards compatibility
228 *
229 * If us is LWS_SET_TIMER_USEC_CANCEL, the sul is removed from the scheduler.
230 * New code can use lws_sul_cancel()
231 */
232
233LWS_VISIBLE LWS_EXTERN void
234lws_sul_schedule(struct lws_context *ctx, int tsi, lws_sorted_usec_list_t *sul,
235 sul_cb_t _cb, lws_usec_t _us);
236LWS_VISIBLE LWS_EXTERN void
237lws_sul_schedule_wakesuspend(struct lws_context *ctx, int tsi,
238 lws_sorted_usec_list_t *sul, sul_cb_t _cb,
239 lws_usec_t _us);
240
241#if defined(LWS_WITH_SUL_DEBUGGING)
242/**
243 * lws_sul_debug_zombies() - assert there are no scheduled sul in a given object
244 *
245 * \param ctx: lws_context
246 * \param po: pointer to the object that is about to be destroyed
247 * \param len: length of the object that is about to be destroyed
248 * \param destroy_description: string clue what any failure is related to
249 *
250 * This is an optional debugging helper that walks the sul scheduler lists
251 * confirming that there are no suls scheduled that live inside the object
252 * footprint described by po and len. When internal objects are about to be
253 * destroyed, like wsi / user_data or secure stream handles, if
254 * LWS_WITH_SUL_DEBUGGING is enabled the scheduler is checked for anything
255 * in the object being destroyed. If something found, an error is printed and
256 * an assert fired.
257 *
258 * Internal sul like timeouts should always be cleaned up correctly, but user
259 * suls in, eg, wsi user_data area, or in secure stream user allocation, may be
260 * the cause of difficult to find bugs if valgrind not available and the user
261 * code left a sul in the scheduler after destroying the object the sul was
262 * living in.
263 */
264LWS_VISIBLE LWS_EXTERN void
265lws_sul_debug_zombies(struct lws_context *ctx, void *po, size_t len,
266 const char *destroy_description);
267#else
268#define lws_sul_debug_zombies(_a, _b, _c, _d)
269#endif
270
271/*
272 * lws_validity_confirmed() - reset the validity timer for a network connection
273 *
274 * \param wsi: the connection that saw traffic proving the connection valid
275 *
276 * Network connections are subject to intervals defined by the context, the
277 * vhost if server connections, or the client connect info if a client
278 * connection. If the connection goes longer than the specified time since
279 * last observing traffic that can only happen if traffic is passing in both
280 * directions, then lws will try to create a PING transaction on the network
281 * connection.
282 *
283 * If the connection reaches the specified `.secs_since_valid_hangup` time
284 * still without any proof of validity, the connection will be closed.
285 *
286 * If the PONG comes, or user code observes traffic that satisfies the proof
287 * that both directions are passing traffic to the peer and calls this api,
288 * the connection validity timer is reset and the scheme repeats.
289 */
290LWS_VISIBLE LWS_EXTERN void
291lws_validity_confirmed(struct lws *wsi);
292
293/*
294 * These are not normally needed, they're exported for the case there's code
295 * using lws_sul for which lws is an optional link dependency.
296 */
297
298LWS_VISIBLE LWS_EXTERN int
299__lws_sul_insert(lws_dll2_owner_t *own, lws_sorted_usec_list_t *sul);
300
301LWS_VISIBLE LWS_EXTERN lws_usec_t
302__lws_sul_service_ripe(lws_dll2_owner_t *own, int own_len, lws_usec_t usnow);
303
304///@}
305