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 */ 35 enum 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 */ 100 LWS_VISIBLE LWS_EXTERN void 101 lws_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 */ 113 void 114 lws_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 */ 150 LWS_VISIBLE LWS_EXTERN void 151 lws_set_timer_usecs(struct lws *wsi, lws_usec_t usecs); 152 153 struct lws_sorted_usec_list; 154 155 typedef void (*sul_cb_t)(struct lws_sorted_usec_list *sul); 156 157 typedef 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 */ 199 LWS_VISIBLE LWS_EXTERN void 200 lws_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 */ 211 LWS_VISIBLE LWS_EXTERN void 212 lws_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 */ 223 LWS_VISIBLE LWS_EXTERN int 224 lws_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 */ 232 233 LWS_VISIBLE LWS_EXTERN void 234 lws_sul_schedule(struct lws_context *ctx, int tsi, lws_sorted_usec_list_t *sul, 235 sul_cb_t _cb, lws_usec_t _us); 236 LWS_VISIBLE LWS_EXTERN void 237 lws_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 */ 264 LWS_VISIBLE LWS_EXTERN void 265 lws_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 */ 290 LWS_VISIBLE LWS_EXTERN void 291 lws_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 */ 297 298 LWS_VISIBLE LWS_EXTERN int 299 __lws_sul_insert(lws_dll2_owner_t *own, lws_sorted_usec_list_t *sul); 300 301 LWS_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