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
54extern "C" {
55#endif
56
57#if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER)
58typedef struct Curl_multi CURLM;
59#else
60typedef void CURLM;
61#endif
62
63typedef 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
94typedef 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
101struct 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};
109typedef 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
118struct 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 */
131CURL_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 */
140CURL_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 */
150CURL_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 */
162CURL_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 */
176CURL_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 */
190CURL_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 */
203CURL_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 */
221CURL_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 */
234CURL_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 */
264CURL_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 */
276CURL_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
299typedef 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 */
316typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
317 long timeout_ms, /* see above */
318 void *userp); /* private callback
319 pointer */
320
321CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()")
322curl_multi_socket(CURLM *multi_handle, curl_socket_t s, int *running_handles);
323
324CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
325 curl_socket_t s,
326 int ev_bitmask,
327 int *running_handles);
328
329CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()")
330curl_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 */
348CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
349 long *milliseconds);
350
351typedef 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 */
413CURL_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 */
426CURL_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 */
439CURL_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
454struct curl_pushheaders; /* forward declaration only */
455
456CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
457 size_t num);
458CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
459 const char *name);
460
461typedef int (*curl_push_callback)(CURL *parent,
462 CURL *easy,
463 size_t num_headers,
464 struct curl_pushheaders *headers,
465 void *userp);
466
467#ifdef __cplusplus
468} /* end of extern "C" */
469#endif
470
471#endif
472