1 #ifndef CURLINC_MULTI_H 2 #define CURLINC_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) Daniel Stenberg, <daniel@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.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 * SPDX-License-Identifier: curl 24 * 25 ***************************************************************************/ 26 /* 27 This is an "external" header file. Don't give away any internals here! 28 29 GOALS 30 31 o Enable a "pull" interface. The application that uses libcurl decides where 32 and when to ask libcurl to get/send data. 33 34 o Enable multiple simultaneous transfers in the same thread without making it 35 complicated for the application. 36 37 o Enable the application to select() on its own file descriptors and curl's 38 file descriptors simultaneous easily. 39 40 */ 41 42 /* 43 * This header file should not really need to include "curl.h" since curl.h 44 * itself includes this file and we expect user applications to do #include 45 * <curl/curl.h> without the need for especially including multi.h. 46 * 47 * For some reason we added this include here at one point, and rather than to 48 * break existing (wrongly written) libcurl applications, we leave it as-is 49 * but with this warning attached. 50 */ 51 #include "curl.h" 52 53 #ifdef __cplusplus 54 extern "C" { 55 #endif 56 57 #if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER) 58 typedef struct Curl_multi CURLM; 59 #else 60 typedef void CURLM; 61 #endif 62 63 typedef enum { 64 CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or 65 curl_multi_socket*() soon */ 66 CURLM_OK, 67 CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ 68 CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ 69 CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ 70 CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ 71 CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ 72 CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ 73 CURLM_ADDED_ALREADY, /* an easy handle already added to a multi handle was 74 attempted to get added - again */ 75 CURLM_RECURSIVE_API_CALL, /* an api function was called from inside a 76 callback */ 77 CURLM_WAKEUP_FAILURE, /* wakeup is unavailable or failed */ 78 CURLM_BAD_FUNCTION_ARGUMENT, /* function called with a bad parameter */ 79 CURLM_ABORTED_BY_CALLBACK, 80 CURLM_UNRECOVERABLE_POLL, 81 CURLM_LAST 82 } CURLMcode; 83 84 /* just to make code nicer when using curl_multi_socket() you can now check 85 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 86 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 87 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 88 89 /* bitmask bits for CURLMOPT_PIPELINING */ 90 #define CURLPIPE_NOTHING 0L 91 #define CURLPIPE_HTTP1 1L 92 #define CURLPIPE_MULTIPLEX 2L 93 94 typedef enum { 95 CURLMSG_NONE, /* first, not used */ 96 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 97 the CURLcode of the transfer */ 98 CURLMSG_LAST /* last, not used */ 99 } CURLMSG; 100 101 struct CURLMsg { 102 CURLMSG msg; /* what this message means */ 103 CURL *easy_handle; /* the handle it concerns */ 104 union { 105 void *whatever; /* message-specific data */ 106 CURLcode result; /* return code for transfer */ 107 } data; 108 }; 109 typedef struct CURLMsg CURLMsg; 110 111 /* Based on poll(2) structure and values. 112 * We don't use pollfd and POLL* constants explicitly 113 * to cover platforms without poll(). */ 114 #define CURL_WAIT_POLLIN 0x0001 115 #define CURL_WAIT_POLLPRI 0x0002 116 #define CURL_WAIT_POLLOUT 0x0004 117 118 struct curl_waitfd { 119 curl_socket_t fd; 120 short events; 121 short revents; 122 }; 123 124 /* 125 * Name: curl_multi_init() 126 * 127 * Desc: initialize multi-style curl usage 128 * 129 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 130 */ 131 CURL_EXTERN CURLM *curl_multi_init(void); 132 133 /* 134 * Name: curl_multi_add_handle() 135 * 136 * Desc: add a standard curl handle to the multi stack 137 * 138 * Returns: CURLMcode type, general multi error code. 139 */ 140 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 141 CURL *curl_handle); 142 143 /* 144 * Name: curl_multi_remove_handle() 145 * 146 * Desc: removes a curl handle from the multi stack again 147 * 148 * Returns: CURLMcode type, general multi error code. 149 */ 150 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 151 CURL *curl_handle); 152 153 /* 154 * Name: curl_multi_fdset() 155 * 156 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 157 * poll() on. We want curl_multi_perform() called as soon as one of 158 * them are ready. 159 * 160 * Returns: CURLMcode type, general multi error code. 161 */ 162 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 163 fd_set *read_fd_set, 164 fd_set *write_fd_set, 165 fd_set *exc_fd_set, 166 int *max_fd); 167 168 /* 169 * Name: curl_multi_wait() 170 * 171 * Desc: Poll on all fds within a CURLM set as well as any 172 * additional fds passed to the function. 173 * 174 * Returns: CURLMcode type, general multi error code. 175 */ 176 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 177 struct curl_waitfd extra_fds[], 178 unsigned int extra_nfds, 179 int timeout_ms, 180 int *ret); 181 182 /* 183 * Name: curl_multi_poll() 184 * 185 * Desc: Poll on all fds within a CURLM set as well as any 186 * additional fds passed to the function. 187 * 188 * Returns: CURLMcode type, general multi error code. 189 */ 190 CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle, 191 struct curl_waitfd extra_fds[], 192 unsigned int extra_nfds, 193 int timeout_ms, 194 int *ret); 195 196 /* 197 * Name: curl_multi_wakeup() 198 * 199 * Desc: wakes up a sleeping curl_multi_poll call. 200 * 201 * Returns: CURLMcode type, general multi error code. 202 */ 203 CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle); 204 205 /* 206 * Name: curl_multi_perform() 207 * 208 * Desc: When the app thinks there's data available for curl it calls this 209 * function to read/write whatever there is right now. This returns 210 * as soon as the reads and writes are done. This function does not 211 * require that there actually is data available for reading or that 212 * data can be written, it can be called just in case. It returns 213 * the number of handles that still transfer data in the second 214 * argument's integer-pointer. 215 * 216 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 217 * returns errors etc regarding the whole multi stack. There might 218 * still have occurred problems on individual transfers even when 219 * this returns OK. 220 */ 221 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 222 int *running_handles); 223 224 /* 225 * Name: curl_multi_cleanup() 226 * 227 * Desc: Cleans up and removes a whole multi stack. It does not free or 228 * touch any individual easy handles in any way. We need to define 229 * in what state those handles will be if this function is called 230 * in the middle of a transfer. 231 * 232 * Returns: CURLMcode type, general multi error code. 233 */ 234 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 235 236 /* 237 * Name: curl_multi_info_read() 238 * 239 * Desc: Ask the multi handle if there's any messages/informationals from 240 * the individual transfers. Messages include informationals such as 241 * error code from the transfer or just the fact that a transfer is 242 * completed. More details on these should be written down as well. 243 * 244 * Repeated calls to this function will return a new struct each 245 * time, until a special "end of msgs" struct is returned as a signal 246 * that there is no more to get at this point. 247 * 248 * The data the returned pointer points to will not survive calling 249 * curl_multi_cleanup(). 250 * 251 * The 'CURLMsg' struct is meant to be very simple and only contain 252 * very basic information. If more involved information is wanted, 253 * we will provide the particular "transfer handle" in that struct 254 * and that should/could/would be used in subsequent 255 * curl_easy_getinfo() calls (or similar). The point being that we 256 * must never expose complex structs to applications, as then we'll 257 * undoubtably get backwards compatibility problems in the future. 258 * 259 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 260 * of structs. It also writes the number of messages left in the 261 * queue (after this read) in the integer the second argument points 262 * to. 263 */ 264 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 265 int *msgs_in_queue); 266 267 /* 268 * Name: curl_multi_strerror() 269 * 270 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 271 * value into the equivalent human readable error string. This is 272 * useful for printing meaningful error messages. 273 * 274 * Returns: A pointer to a null-terminated error message. 275 */ 276 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 277 278 /* 279 * Name: curl_multi_socket() and 280 * curl_multi_socket_all() 281 * 282 * Desc: An alternative version of curl_multi_perform() that allows the 283 * application to pass in one of the file descriptors that have been 284 * detected to have "action" on them and let libcurl perform. 285 * See man page for details. 286 */ 287 #define CURL_POLL_NONE 0 288 #define CURL_POLL_IN 1 289 #define CURL_POLL_OUT 2 290 #define CURL_POLL_INOUT 3 291 #define CURL_POLL_REMOVE 4 292 293 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 294 295 #define CURL_CSELECT_IN 0x01 296 #define CURL_CSELECT_OUT 0x02 297 #define CURL_CSELECT_ERR 0x04 298 299 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 300 curl_socket_t s, /* socket */ 301 int what, /* see above */ 302 void *userp, /* private callback 303 pointer */ 304 void *socketp); /* private socket 305 pointer */ 306 /* 307 * Name: curl_multi_timer_callback 308 * 309 * Desc: Called by libcurl whenever the library detects a change in the 310 * maximum number of milliseconds the app is allowed to wait before 311 * curl_multi_socket() or curl_multi_perform() must be called 312 * (to allow libcurl's timed events to take place). 313 * 314 * Returns: The callback should return zero. 315 */ 316 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 317 long timeout_ms, /* see above */ 318 void *userp); /* private callback 319 pointer */ 320 321 CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()") 322 curl_multi_socket(CURLM *multi_handle, curl_socket_t s, int *running_handles); 323 324 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 325 curl_socket_t s, 326 int ev_bitmask, 327 int *running_handles); 328 329 CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()") 330 curl_multi_socket_all(CURLM *multi_handle, int *running_handles); 331 332 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 333 /* This macro below was added in 7.16.3 to push users who recompile to use 334 the new curl_multi_socket_action() instead of the old curl_multi_socket() 335 */ 336 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 337 #endif 338 339 /* 340 * Name: curl_multi_timeout() 341 * 342 * Desc: Returns the maximum number of milliseconds the app is allowed to 343 * wait before curl_multi_socket() or curl_multi_perform() must be 344 * called (to allow libcurl's timed events to take place). 345 * 346 * Returns: CURLM error code. 347 */ 348 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 349 long *milliseconds); 350 351 typedef enum { 352 /* This is the socket callback function pointer */ 353 CURLOPT(CURLMOPT_SOCKETFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 1), 354 355 /* This is the argument passed to the socket callback */ 356 CURLOPT(CURLMOPT_SOCKETDATA, CURLOPTTYPE_OBJECTPOINT, 2), 357 358 /* set to 1 to enable pipelining for this multi handle */ 359 CURLOPT(CURLMOPT_PIPELINING, CURLOPTTYPE_LONG, 3), 360 361 /* This is the timer callback function pointer */ 362 CURLOPT(CURLMOPT_TIMERFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 4), 363 364 /* This is the argument passed to the timer callback */ 365 CURLOPT(CURLMOPT_TIMERDATA, CURLOPTTYPE_OBJECTPOINT, 5), 366 367 /* maximum number of entries in the connection cache */ 368 CURLOPT(CURLMOPT_MAXCONNECTS, CURLOPTTYPE_LONG, 6), 369 370 /* maximum number of (pipelining) connections to one host */ 371 CURLOPT(CURLMOPT_MAX_HOST_CONNECTIONS, CURLOPTTYPE_LONG, 7), 372 373 /* maximum number of requests in a pipeline */ 374 CURLOPT(CURLMOPT_MAX_PIPELINE_LENGTH, CURLOPTTYPE_LONG, 8), 375 376 /* a connection with a content-length longer than this 377 will not be considered for pipelining */ 378 CURLOPT(CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 9), 379 380 /* a connection with a chunk length longer than this 381 will not be considered for pipelining */ 382 CURLOPT(CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 10), 383 384 /* a list of site names(+port) that are blocked from pipelining */ 385 CURLOPT(CURLMOPT_PIPELINING_SITE_BL, CURLOPTTYPE_OBJECTPOINT, 11), 386 387 /* a list of server types that are blocked from pipelining */ 388 CURLOPT(CURLMOPT_PIPELINING_SERVER_BL, CURLOPTTYPE_OBJECTPOINT, 12), 389 390 /* maximum number of open connections in total */ 391 CURLOPT(CURLMOPT_MAX_TOTAL_CONNECTIONS, CURLOPTTYPE_LONG, 13), 392 393 /* This is the server push callback function pointer */ 394 CURLOPT(CURLMOPT_PUSHFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 14), 395 396 /* This is the argument passed to the server push callback */ 397 CURLOPT(CURLMOPT_PUSHDATA, CURLOPTTYPE_OBJECTPOINT, 15), 398 399 /* maximum number of concurrent streams to support on a connection */ 400 CURLOPT(CURLMOPT_MAX_CONCURRENT_STREAMS, CURLOPTTYPE_LONG, 16), 401 402 CURLMOPT_LASTENTRY /* the last unused */ 403 } CURLMoption; 404 405 406 /* 407 * Name: curl_multi_setopt() 408 * 409 * Desc: Sets options for the multi handle. 410 * 411 * Returns: CURLM error code. 412 */ 413 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 414 CURLMoption option, ...); 415 416 417 /* 418 * Name: curl_multi_assign() 419 * 420 * Desc: This function sets an association in the multi handle between the 421 * given socket and a private pointer of the application. This is 422 * (only) useful for curl_multi_socket uses. 423 * 424 * Returns: CURLM error code. 425 */ 426 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 427 curl_socket_t sockfd, void *sockp); 428 429 /* 430 * Name: curl_multi_get_handles() 431 * 432 * Desc: Returns an allocated array holding all handles currently added to 433 * the multi handle. Marks the final entry with a NULL pointer. If 434 * there is no easy handle added to the multi handle, this function 435 * returns an array with the first entry as a NULL pointer. 436 * 437 * Returns: NULL on failure, otherwise a CURL **array pointer 438 */ 439 CURL_EXTERN CURL **curl_multi_get_handles(CURLM *multi_handle); 440 441 /* 442 * Name: curl_push_callback 443 * 444 * Desc: This callback gets called when a new stream is being pushed by the 445 * server. It approves or denies the new stream. It can also decide 446 * to completely fail the connection. 447 * 448 * Returns: CURL_PUSH_OK, CURL_PUSH_DENY or CURL_PUSH_ERROROUT 449 */ 450 #define CURL_PUSH_OK 0 451 #define CURL_PUSH_DENY 1 452 #define CURL_PUSH_ERROROUT 2 /* added in 7.72.0 */ 453 454 struct curl_pushheaders; /* forward declaration only */ 455 456 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, 457 size_t num); 458 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, 459 const char *name); 460 461 typedef int (*curl_push_callback)(CURL *parent, 462 CURL *easy, 463 size_t num_headers, 464 struct curl_pushheaders *headers, 465 void *userp); 466 467 /* 468 * Name: curl_multi_waitfds() 469 * 470 * Desc: Ask curl for fds for polling. The app can use these to poll on. 471 * We want curl_multi_perform() called as soon as one of them are 472 * ready. Passing zero size allows to get just a number of fds. 473 * 474 * Returns: CURLMcode type, general multi error code. 475 */ 476 CURL_EXTERN CURLMcode curl_multi_waitfds(CURLM *multi, 477 struct curl_waitfd *ufds, 478 unsigned int size, 479 unsigned int *fd_count); 480 481 #ifdef __cplusplus 482 } /* end of extern "C" */ 483 #endif 484 485 #endif 486
