1 #ifndef CURLINC_MULTI_H 2 #define CURLINC_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2019, 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.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_RECURSIVE_API_CALL, /* an api function was called from inside a 74 callback */ 75 CURLM_LAST 76 } CURLMcode; 77 78 /* just to make code nicer when using curl_multi_socket() you can now check 79 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 80 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 81 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 82 83 /* bitmask bits for CURLMOPT_PIPELINING */ 84 #define CURLPIPE_NOTHING 0L 85 #define CURLPIPE_HTTP1 1L 86 #define CURLPIPE_MULTIPLEX 2L 87 88 typedef enum { 89 CURLMSG_NONE, /* first, not used */ 90 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 91 the CURLcode of the transfer */ 92 CURLMSG_LAST /* last, not used */ 93 } CURLMSG; 94 95 struct CURLMsg { 96 CURLMSG msg; /* what this message means */ 97 CURL *easy_handle; /* the handle it concerns */ 98 union { 99 void *whatever; /* message-specific data */ 100 CURLcode result; /* return code for transfer */ 101 } data; 102 }; 103 typedef struct CURLMsg CURLMsg; 104 105 /* Based on poll(2) structure and values. 106 * We don't use pollfd and POLL* constants explicitly 107 * to cover platforms without poll(). */ 108 #define CURL_WAIT_POLLIN 0x0001 109 #define CURL_WAIT_POLLPRI 0x0002 110 #define CURL_WAIT_POLLOUT 0x0004 111 112 struct curl_waitfd { 113 curl_socket_t fd; 114 short events; 115 short revents; /* not supported yet */ 116 }; 117 118 /* 119 * Name: curl_multi_init() 120 * 121 * Desc: inititalize multi-style curl usage 122 * 123 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 124 */ 125 CURL_EXTERN CURLM *curl_multi_init(void); 126 127 /* 128 * Name: curl_multi_add_handle() 129 * 130 * Desc: add a standard curl handle to the multi stack 131 * 132 * Returns: CURLMcode type, general multi error code. 133 */ 134 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 135 CURL *curl_handle); 136 137 /* 138 * Name: curl_multi_remove_handle() 139 * 140 * Desc: removes a curl handle from the multi stack again 141 * 142 * Returns: CURLMcode type, general multi error code. 143 */ 144 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 145 CURL *curl_handle); 146 147 /* 148 * Name: curl_multi_fdset() 149 * 150 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 151 * poll() on. We want curl_multi_perform() called as soon as one of 152 * them are ready. 153 * 154 * Returns: CURLMcode type, general multi error code. 155 */ 156 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 157 fd_set *read_fd_set, 158 fd_set *write_fd_set, 159 fd_set *exc_fd_set, 160 int *max_fd); 161 162 /* 163 * Name: curl_multi_wait() 164 * 165 * Desc: Poll on all fds within a CURLM set as well as any 166 * additional fds passed to the function. 167 * 168 * Returns: CURLMcode type, general multi error code. 169 */ 170 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 171 struct curl_waitfd extra_fds[], 172 unsigned int extra_nfds, 173 int timeout_ms, 174 int *ret); 175 176 /* 177 * Name: curl_multi_poll() 178 * 179 * Desc: Poll on all fds within a CURLM set as well as any 180 * additional fds passed to the function. 181 * 182 * Returns: CURLMcode type, general multi error code. 183 */ 184 CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle, 185 struct curl_waitfd extra_fds[], 186 unsigned int extra_nfds, 187 int timeout_ms, 188 int *ret); 189 190 /* 191 * Name: curl_multi_perform() 192 * 193 * Desc: When the app thinks there's data available for curl it calls this 194 * function to read/write whatever there is right now. This returns 195 * as soon as the reads and writes are done. This function does not 196 * require that there actually is data available for reading or that 197 * data can be written, it can be called just in case. It returns 198 * the number of handles that still transfer data in the second 199 * argument's integer-pointer. 200 * 201 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 202 * returns errors etc regarding the whole multi stack. There might 203 * still have occurred problems on individual transfers even when 204 * this returns OK. 205 */ 206 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 207 int *running_handles); 208 209 /* 210 * Name: curl_multi_cleanup() 211 * 212 * Desc: Cleans up and removes a whole multi stack. It does not free or 213 * touch any individual easy handles in any way. We need to define 214 * in what state those handles will be if this function is called 215 * in the middle of a transfer. 216 * 217 * Returns: CURLMcode type, general multi error code. 218 */ 219 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 220 221 /* 222 * Name: curl_multi_info_read() 223 * 224 * Desc: Ask the multi handle if there's any messages/informationals from 225 * the individual transfers. Messages include informationals such as 226 * error code from the transfer or just the fact that a transfer is 227 * completed. More details on these should be written down as well. 228 * 229 * Repeated calls to this function will return a new struct each 230 * time, until a special "end of msgs" struct is returned as a signal 231 * that there is no more to get at this point. 232 * 233 * The data the returned pointer points to will not survive calling 234 * curl_multi_cleanup(). 235 * 236 * The 'CURLMsg' struct is meant to be very simple and only contain 237 * very basic information. If more involved information is wanted, 238 * we will provide the particular "transfer handle" in that struct 239 * and that should/could/would be used in subsequent 240 * curl_easy_getinfo() calls (or similar). The point being that we 241 * must never expose complex structs to applications, as then we'll 242 * undoubtably get backwards compatibility problems in the future. 243 * 244 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 245 * of structs. It also writes the number of messages left in the 246 * queue (after this read) in the integer the second argument points 247 * to. 248 */ 249 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 250 int *msgs_in_queue); 251 252 /* 253 * Name: curl_multi_strerror() 254 * 255 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 256 * value into the equivalent human readable error string. This is 257 * useful for printing meaningful error messages. 258 * 259 * Returns: A pointer to a zero-terminated error message. 260 */ 261 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 262 263 /* 264 * Name: curl_multi_socket() and 265 * curl_multi_socket_all() 266 * 267 * Desc: An alternative version of curl_multi_perform() that allows the 268 * application to pass in one of the file descriptors that have been 269 * detected to have "action" on them and let libcurl perform. 270 * See man page for details. 271 */ 272 #define CURL_POLL_NONE 0 273 #define CURL_POLL_IN 1 274 #define CURL_POLL_OUT 2 275 #define CURL_POLL_INOUT 3 276 #define CURL_POLL_REMOVE 4 277 278 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 279 280 #define CURL_CSELECT_IN 0x01 281 #define CURL_CSELECT_OUT 0x02 282 #define CURL_CSELECT_ERR 0x04 283 284 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 285 curl_socket_t s, /* socket */ 286 int what, /* see above */ 287 void *userp, /* private callback 288 pointer */ 289 void *socketp); /* private socket 290 pointer */ 291 /* 292 * Name: curl_multi_timer_callback 293 * 294 * Desc: Called by libcurl whenever the library detects a change in the 295 * maximum number of milliseconds the app is allowed to wait before 296 * curl_multi_socket() or curl_multi_perform() must be called 297 * (to allow libcurl's timed events to take place). 298 * 299 * Returns: The callback should return zero. 300 */ 301 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 302 long timeout_ms, /* see above */ 303 void *userp); /* private callback 304 pointer */ 305 306 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 307 int *running_handles); 308 309 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 310 curl_socket_t s, 311 int ev_bitmask, 312 int *running_handles); 313 314 CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 315 int *running_handles); 316 317 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 318 /* This macro below was added in 7.16.3 to push users who recompile to use 319 the new curl_multi_socket_action() instead of the old curl_multi_socket() 320 */ 321 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 322 #endif 323 324 /* 325 * Name: curl_multi_timeout() 326 * 327 * Desc: Returns the maximum number of milliseconds the app is allowed to 328 * wait before curl_multi_socket() or curl_multi_perform() must be 329 * called (to allow libcurl's timed events to take place). 330 * 331 * Returns: CURLM error code. 332 */ 333 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 334 long *milliseconds); 335 336 #undef CINIT /* re-using the same name as in curl.h */ 337 338 #ifdef CURL_ISOCPP 339 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 340 #else 341 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 342 #define LONG CURLOPTTYPE_LONG 343 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 344 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 345 #define OFF_T CURLOPTTYPE_OFF_T 346 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number 347 #endif 348 349 typedef enum { 350 /* This is the socket callback function pointer */ 351 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 352 353 /* This is the argument passed to the socket callback */ 354 CINIT(SOCKETDATA, OBJECTPOINT, 2), 355 356 /* set to 1 to enable pipelining for this multi handle */ 357 CINIT(PIPELINING, LONG, 3), 358 359 /* This is the timer callback function pointer */ 360 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 361 362 /* This is the argument passed to the timer callback */ 363 CINIT(TIMERDATA, OBJECTPOINT, 5), 364 365 /* maximum number of entries in the connection cache */ 366 CINIT(MAXCONNECTS, LONG, 6), 367 368 /* maximum number of (pipelining) connections to one host */ 369 CINIT(MAX_HOST_CONNECTIONS, LONG, 7), 370 371 /* maximum number of requests in a pipeline */ 372 CINIT(MAX_PIPELINE_LENGTH, LONG, 8), 373 374 /* a connection with a content-length longer than this 375 will not be considered for pipelining */ 376 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9), 377 378 /* a connection with a chunk length longer than this 379 will not be considered for pipelining */ 380 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10), 381 382 /* a list of site names(+port) that are blacklisted from 383 pipelining */ 384 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11), 385 386 /* a list of server types that are blacklisted from 387 pipelining */ 388 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12), 389 390 /* maximum number of open connections in total */ 391 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13), 392 393 /* This is the server push callback function pointer */ 394 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14), 395 396 /* This is the argument passed to the server push callback */ 397 CINIT(PUSHDATA, OBJECTPOINT, 15), 398 399 CURLMOPT_LASTENTRY /* the last unused */ 400 } CURLMoption; 401 402 403 /* 404 * Name: curl_multi_setopt() 405 * 406 * Desc: Sets options for the multi handle. 407 * 408 * Returns: CURLM error code. 409 */ 410 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 411 CURLMoption option, ...); 412 413 414 /* 415 * Name: curl_multi_assign() 416 * 417 * Desc: This function sets an association in the multi handle between the 418 * given socket and a private pointer of the application. This is 419 * (only) useful for curl_multi_socket uses. 420 * 421 * Returns: CURLM error code. 422 */ 423 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 424 curl_socket_t sockfd, void *sockp); 425 426 427 /* 428 * Name: curl_push_callback 429 * 430 * Desc: This callback gets called when a new stream is being pushed by the 431 * server. It approves or denies the new stream. 432 * 433 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY. 434 */ 435 #define CURL_PUSH_OK 0 436 #define CURL_PUSH_DENY 1 437 438 struct curl_pushheaders; /* forward declaration only */ 439 440 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, 441 size_t num); 442 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, 443 const char *name); 444 445 typedef int (*curl_push_callback)(CURL *parent, 446 CURL *easy, 447 size_t num_headers, 448 struct curl_pushheaders *headers, 449 void *userp); 450 451 #ifdef __cplusplus 452 } /* end of extern "C" */ 453 #endif 454 455 #endif 456