1 #ifndef __CURL_MULTI_H 2 #define __CURL_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel (at) haxx.se>, et al. 11 * 12 * This software is licensed as described in the file COPYING, which 13 * you should have received as part of this distribution. The terms 14 * are also available at https://curl.haxx.se/docs/copyright.html. 15 * 16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 17 * copies of the Software, and permit persons to whom the Software is 18 * furnished to do so, under the terms of the COPYING file. 19 * 20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 21 * KIND, either express or implied. 22 * 23 ***************************************************************************/ 24 /* 25 This is an "external" header file. Don't give away any internals here! 26 27 GOALS 28 29 o Enable a "pull" interface. The application that uses libcurl decides where 30 and when to ask libcurl to get/send data. 31 32 o Enable multiple simultaneous transfers in the same thread without making it 33 complicated for the application. 34 35 o Enable the application to select() on its own file descriptors and curl's 36 file descriptors simultaneous easily. 37 38 */ 39 40 /* 41 * This header file should not really need to include "curl.h" since curl.h 42 * itself includes this file and we expect user applications to do #include 43 * <curl/curl.h> without the need for especially including multi.h. 44 * 45 * For some reason we added this include here at one point, and rather than to 46 * break existing (wrongly written) libcurl applications, we leave it as-is 47 * but with this warning attached. 48 */ 49 #include "curl.h" 50 51 #ifdef __cplusplus 52 extern "C" { 53 #endif 54 55 #if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER) 56 typedef struct Curl_multi CURLM; 57 #else 58 typedef void CURLM; 59 #endif 60 61 typedef enum { 62 CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or 63 curl_multi_socket*() soon */ 64 CURLM_OK, 65 CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ 66 CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ 67 CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ 68 CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ 69 CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ 70 CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ 71 CURLM_ADDED_ALREADY, /* an easy handle already added to a multi handle was 72 attempted to get added - again */ 73 CURLM_LAST 74 } CURLMcode; 75 76 /* just to make code nicer when using curl_multi_socket() you can now check 77 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 78 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 79 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 80 81 /* bitmask bits for CURLMOPT_PIPELINING */ 82 #define CURLPIPE_NOTHING 0L 83 #define CURLPIPE_HTTP1 1L 84 #define CURLPIPE_MULTIPLEX 2L 85 86 typedef enum { 87 CURLMSG_NONE, /* first, not used */ 88 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 89 the CURLcode of the transfer */ 90 CURLMSG_LAST /* last, not used */ 91 } CURLMSG; 92 93 struct CURLMsg { 94 CURLMSG msg; /* what this message means */ 95 CURL *easy_handle; /* the handle it concerns */ 96 union { 97 void *whatever; /* message-specific data */ 98 CURLcode result; /* return code for transfer */ 99 } data; 100 }; 101 typedef struct CURLMsg CURLMsg; 102 103 /* Based on poll(2) structure and values. 104 * We don't use pollfd and POLL* constants explicitly 105 * to cover platforms without poll(). */ 106 #define CURL_WAIT_POLLIN 0x0001 107 #define CURL_WAIT_POLLPRI 0x0002 108 #define CURL_WAIT_POLLOUT 0x0004 109 110 struct curl_waitfd { 111 curl_socket_t fd; 112 short events; 113 short revents; /* not supported yet */ 114 }; 115 116 /* 117 * Name: curl_multi_init() 118 * 119 * Desc: inititalize multi-style curl usage 120 * 121 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 122 */ 123 CURL_EXTERN CURLM *curl_multi_init(void); 124 125 /* 126 * Name: curl_multi_add_handle() 127 * 128 * Desc: add a standard curl handle to the multi stack 129 * 130 * Returns: CURLMcode type, general multi error code. 131 */ 132 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 133 CURL *curl_handle); 134 135 /* 136 * Name: curl_multi_remove_handle() 137 * 138 * Desc: removes a curl handle from the multi stack again 139 * 140 * Returns: CURLMcode type, general multi error code. 141 */ 142 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 143 CURL *curl_handle); 144 145 /* 146 * Name: curl_multi_fdset() 147 * 148 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 149 * poll() on. We want curl_multi_perform() called as soon as one of 150 * them are ready. 151 * 152 * Returns: CURLMcode type, general multi error code. 153 */ 154 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 155 fd_set *read_fd_set, 156 fd_set *write_fd_set, 157 fd_set *exc_fd_set, 158 int *max_fd); 159 160 /* 161 * Name: curl_multi_wait() 162 * 163 * Desc: Poll on all fds within a CURLM set as well as any 164 * additional fds passed to the function. 165 * 166 * Returns: CURLMcode type, general multi error code. 167 */ 168 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 169 struct curl_waitfd extra_fds[], 170 unsigned int extra_nfds, 171 int timeout_ms, 172 int *ret); 173 174 /* 175 * Name: curl_multi_perform() 176 * 177 * Desc: When the app thinks there's data available for curl it calls this 178 * function to read/write whatever there is right now. This returns 179 * as soon as the reads and writes are done. This function does not 180 * require that there actually is data available for reading or that 181 * data can be written, it can be called just in case. It returns 182 * the number of handles that still transfer data in the second 183 * argument's integer-pointer. 184 * 185 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 186 * returns errors etc regarding the whole multi stack. There might 187 * still have occurred problems on invidual transfers even when this 188 * returns OK. 189 */ 190 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 191 int *running_handles); 192 193 /* 194 * Name: curl_multi_cleanup() 195 * 196 * Desc: Cleans up and removes a whole multi stack. It does not free or 197 * touch any individual easy handles in any way. We need to define 198 * in what state those handles will be if this function is called 199 * in the middle of a transfer. 200 * 201 * Returns: CURLMcode type, general multi error code. 202 */ 203 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 204 205 /* 206 * Name: curl_multi_info_read() 207 * 208 * Desc: Ask the multi handle if there's any messages/informationals from 209 * the individual transfers. Messages include informationals such as 210 * error code from the transfer or just the fact that a transfer is 211 * completed. More details on these should be written down as well. 212 * 213 * Repeated calls to this function will return a new struct each 214 * time, until a special "end of msgs" struct is returned as a signal 215 * that there is no more to get at this point. 216 * 217 * The data the returned pointer points to will not survive calling 218 * curl_multi_cleanup(). 219 * 220 * The 'CURLMsg' struct is meant to be very simple and only contain 221 * very basic information. If more involved information is wanted, 222 * we will provide the particular "transfer handle" in that struct 223 * and that should/could/would be used in subsequent 224 * curl_easy_getinfo() calls (or similar). The point being that we 225 * must never expose complex structs to applications, as then we'll 226 * undoubtably get backwards compatibility problems in the future. 227 * 228 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 229 * of structs. It also writes the number of messages left in the 230 * queue (after this read) in the integer the second argument points 231 * to. 232 */ 233 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 234 int *msgs_in_queue); 235 236 /* 237 * Name: curl_multi_strerror() 238 * 239 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 240 * value into the equivalent human readable error string. This is 241 * useful for printing meaningful error messages. 242 * 243 * Returns: A pointer to a zero-terminated error message. 244 */ 245 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 246 247 /* 248 * Name: curl_multi_socket() and 249 * curl_multi_socket_all() 250 * 251 * Desc: An alternative version of curl_multi_perform() that allows the 252 * application to pass in one of the file descriptors that have been 253 * detected to have "action" on them and let libcurl perform. 254 * See man page for details. 255 */ 256 #define CURL_POLL_NONE 0 257 #define CURL_POLL_IN 1 258 #define CURL_POLL_OUT 2 259 #define CURL_POLL_INOUT 3 260 #define CURL_POLL_REMOVE 4 261 262 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 263 264 #define CURL_CSELECT_IN 0x01 265 #define CURL_CSELECT_OUT 0x02 266 #define CURL_CSELECT_ERR 0x04 267 268 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 269 curl_socket_t s, /* socket */ 270 int what, /* see above */ 271 void *userp, /* private callback 272 pointer */ 273 void *socketp); /* private socket 274 pointer */ 275 /* 276 * Name: curl_multi_timer_callback 277 * 278 * Desc: Called by libcurl whenever the library detects a change in the 279 * maximum number of milliseconds the app is allowed to wait before 280 * curl_multi_socket() or curl_multi_perform() must be called 281 * (to allow libcurl's timed events to take place). 282 * 283 * Returns: The callback should return zero. 284 */ 285 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 286 long timeout_ms, /* see above */ 287 void *userp); /* private callback 288 pointer */ 289 290 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 291 int *running_handles); 292 293 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 294 curl_socket_t s, 295 int ev_bitmask, 296 int *running_handles); 297 298 CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 299 int *running_handles); 300 301 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 302 /* This macro below was added in 7.16.3 to push users who recompile to use 303 the new curl_multi_socket_action() instead of the old curl_multi_socket() 304 */ 305 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 306 #endif 307 308 /* 309 * Name: curl_multi_timeout() 310 * 311 * Desc: Returns the maximum number of milliseconds the app is allowed to 312 * wait before curl_multi_socket() or curl_multi_perform() must be 313 * called (to allow libcurl's timed events to take place). 314 * 315 * Returns: CURLM error code. 316 */ 317 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 318 long *milliseconds); 319 320 #undef CINIT /* re-using the same name as in curl.h */ 321 322 #ifdef CURL_ISOCPP 323 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 324 #else 325 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 326 #define LONG CURLOPTTYPE_LONG 327 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 328 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 329 #define OFF_T CURLOPTTYPE_OFF_T 330 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number 331 #endif 332 333 typedef enum { 334 /* This is the socket callback function pointer */ 335 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 336 337 /* This is the argument passed to the socket callback */ 338 CINIT(SOCKETDATA, OBJECTPOINT, 2), 339 340 /* set to 1 to enable pipelining for this multi handle */ 341 CINIT(PIPELINING, LONG, 3), 342 343 /* This is the timer callback function pointer */ 344 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 345 346 /* This is the argument passed to the timer callback */ 347 CINIT(TIMERDATA, OBJECTPOINT, 5), 348 349 /* maximum number of entries in the connection cache */ 350 CINIT(MAXCONNECTS, LONG, 6), 351 352 /* maximum number of (pipelining) connections to one host */ 353 CINIT(MAX_HOST_CONNECTIONS, LONG, 7), 354 355 /* maximum number of requests in a pipeline */ 356 CINIT(MAX_PIPELINE_LENGTH, LONG, 8), 357 358 /* a connection with a content-length longer than this 359 will not be considered for pipelining */ 360 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9), 361 362 /* a connection with a chunk length longer than this 363 will not be considered for pipelining */ 364 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10), 365 366 /* a list of site names(+port) that are blacklisted from 367 pipelining */ 368 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11), 369 370 /* a list of server types that are blacklisted from 371 pipelining */ 372 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12), 373 374 /* maximum number of open connections in total */ 375 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13), 376 377 /* This is the server push callback function pointer */ 378 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14), 379 380 /* This is the argument passed to the server push callback */ 381 CINIT(PUSHDATA, OBJECTPOINT, 15), 382 383 CURLMOPT_LASTENTRY /* the last unused */ 384 } CURLMoption; 385 386 387 /* 388 * Name: curl_multi_setopt() 389 * 390 * Desc: Sets options for the multi handle. 391 * 392 * Returns: CURLM error code. 393 */ 394 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 395 CURLMoption option, ...); 396 397 398 /* 399 * Name: curl_multi_assign() 400 * 401 * Desc: This function sets an association in the multi handle between the 402 * given socket and a private pointer of the application. This is 403 * (only) useful for curl_multi_socket uses. 404 * 405 * Returns: CURLM error code. 406 */ 407 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 408 curl_socket_t sockfd, void *sockp); 409 410 411 /* 412 * Name: curl_push_callback 413 * 414 * Desc: This callback gets called when a new stream is being pushed by the 415 * server. It approves or denies the new stream. 416 * 417 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY. 418 */ 419 #define CURL_PUSH_OK 0 420 #define CURL_PUSH_DENY 1 421 422 struct curl_pushheaders; /* forward declaration only */ 423 424 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, 425 size_t num); 426 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, 427 const char *name); 428 429 typedef int (*curl_push_callback)(CURL *parent, 430 CURL *easy, 431 size_t num_headers, 432 struct curl_pushheaders *headers, 433 void *userp); 434 435 #ifdef __cplusplus 436 } /* end of extern "C" */ 437 #endif 438 439 #endif 440
