1#ifndef CURLINC_MULTI_H
2#define CURLINC_MULTI_H
3/***************************************************************************
4 * _ _ ____ _
5 * Project ___| | | | _ \| |
6 * / __| | | | |_) | |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2021, 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 ***************************************************************************/
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
52extern "C" {
53#endif
54
55#if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER)
56typedef struct Curl_multi CURLM;
57#else
58typedef void CURLM;
59#endif
60
61typedef 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_WAKEUP_FAILURE, /* wakeup is unavailable or failed */
76 CURLM_BAD_FUNCTION_ARGUMENT, /* function called with a bad parameter */
77 CURLM_ABORTED_BY_CALLBACK,
78 CURLM_LAST
79} CURLMcode;
80
81/* just to make code nicer when using curl_multi_socket() you can now check
82 for CURLM_CALL_MULTI_SOCKET too in the same style it works for
83 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
84#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
85
86/* bitmask bits for CURLMOPT_PIPELINING */
87#define CURLPIPE_NOTHING 0L
88#define CURLPIPE_HTTP1 1L
89#define CURLPIPE_MULTIPLEX 2L
90
91typedef enum {
92 CURLMSG_NONE, /* first, not used */
93 CURLMSG_DONE, /* This easy handle has completed. 'result' contains
94 the CURLcode of the transfer */
95 CURLMSG_LAST /* last, not used */
96} CURLMSG;
97
98struct CURLMsg {
99 CURLMSG msg; /* what this message means */
100 CURL *easy_handle; /* the handle it concerns */
101 union {
102 void *whatever; /* message-specific data */
103 CURLcode result; /* return code for transfer */
104 } data;
105};
106typedef struct CURLMsg CURLMsg;
107
108/* Based on poll(2) structure and values.
109 * We don't use pollfd and POLL* constants explicitly
110 * to cover platforms without poll(). */
111#define CURL_WAIT_POLLIN 0x0001
112#define CURL_WAIT_POLLPRI 0x0002
113#define CURL_WAIT_POLLOUT 0x0004
114
115struct curl_waitfd {
116 curl_socket_t fd;
117 short events;
118 short revents; /* not supported yet */
119};
120
121/*
122 * Name: curl_multi_init()
123 *
124 * Desc: inititalize multi-style curl usage
125 *
126 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
127 */
128CURL_EXTERN CURLM *curl_multi_init(void);
129
130/*
131 * Name: curl_multi_add_handle()
132 *
133 * Desc: add a standard curl handle to the multi stack
134 *
135 * Returns: CURLMcode type, general multi error code.
136 */
137CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,
138 CURL *curl_handle);
139
140 /*
141 * Name: curl_multi_remove_handle()
142 *
143 * Desc: removes a curl handle from the multi stack again
144 *
145 * Returns: CURLMcode type, general multi error code.
146 */
147CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
148 CURL *curl_handle);
149
150 /*
151 * Name: curl_multi_fdset()
152 *
153 * Desc: Ask curl for its fd_set sets. The app can use these to select() or
154 * poll() on. We want curl_multi_perform() called as soon as one of
155 * them are ready.
156 *
157 * Returns: CURLMcode type, general multi error code.
158 */
159CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,
160 fd_set *read_fd_set,
161 fd_set *write_fd_set,
162 fd_set *exc_fd_set,
163 int *max_fd);
164
165/*
166 * Name: curl_multi_wait()
167 *
168 * Desc: Poll on all fds within a CURLM set as well as any
169 * additional fds passed to the function.
170 *
171 * Returns: CURLMcode type, general multi error code.
172 */
173CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
174 struct curl_waitfd extra_fds[],
175 unsigned int extra_nfds,
176 int timeout_ms,
177 int *ret);
178
179/*
180 * Name: curl_multi_poll()
181 *
182 * Desc: Poll on all fds within a CURLM set as well as any
183 * additional fds passed to the function.
184 *
185 * Returns: CURLMcode type, general multi error code.
186 */
187CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle,
188 struct curl_waitfd extra_fds[],
189 unsigned int extra_nfds,
190 int timeout_ms,
191 int *ret);
192
193/*
194 * Name: curl_multi_wakeup()
195 *
196 * Desc: wakes up a sleeping curl_multi_poll call.
197 *
198 * Returns: CURLMcode type, general multi error code.
199 */
200CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle);
201
202 /*
203 * Name: curl_multi_perform()
204 *
205 * Desc: When the app thinks there's data available for curl it calls this
206 * function to read/write whatever there is right now. This returns
207 * as soon as the reads and writes are done. This function does not
208 * require that there actually is data available for reading or that
209 * data can be written, it can be called just in case. It returns
210 * the number of handles that still transfer data in the second
211 * argument's integer-pointer.
212 *
213 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
214 * returns errors etc regarding the whole multi stack. There might
215 * still have occurred problems on individual transfers even when
216 * this returns OK.
217 */
218CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
219 int *running_handles);
220
221 /*
222 * Name: curl_multi_cleanup()
223 *
224 * Desc: Cleans up and removes a whole multi stack. It does not free or
225 * touch any individual easy handles in any way. We need to define
226 * in what state those handles will be if this function is called
227 * in the middle of a transfer.
228 *
229 * Returns: CURLMcode type, general multi error code.
230 */
231CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
232
233/*
234 * Name: curl_multi_info_read()
235 *
236 * Desc: Ask the multi handle if there's any messages/informationals from
237 * the individual transfers. Messages include informationals such as
238 * error code from the transfer or just the fact that a transfer is
239 * completed. More details on these should be written down as well.
240 *
241 * Repeated calls to this function will return a new struct each
242 * time, until a special "end of msgs" struct is returned as a signal
243 * that there is no more to get at this point.
244 *
245 * The data the returned pointer points to will not survive calling
246 * curl_multi_cleanup().
247 *
248 * The 'CURLMsg' struct is meant to be very simple and only contain
249 * very basic information. If more involved information is wanted,
250 * we will provide the particular "transfer handle" in that struct
251 * and that should/could/would be used in subsequent
252 * curl_easy_getinfo() calls (or similar). The point being that we
253 * must never expose complex structs to applications, as then we'll
254 * undoubtably get backwards compatibility problems in the future.
255 *
256 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
257 * of structs. It also writes the number of messages left in the
258 * queue (after this read) in the integer the second argument points
259 * to.
260 */
261CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
262 int *msgs_in_queue);
263
264/*
265 * Name: curl_multi_strerror()
266 *
267 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
268 * value into the equivalent human readable error string. This is
269 * useful for printing meaningful error messages.
270 *
271 * Returns: A pointer to a null-terminated error message.
272 */
273CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
274
275/*
276 * Name: curl_multi_socket() and
277 * curl_multi_socket_all()
278 *
279 * Desc: An alternative version of curl_multi_perform() that allows the
280 * application to pass in one of the file descriptors that have been
281 * detected to have "action" on them and let libcurl perform.
282 * See man page for details.
283 */
284#define CURL_POLL_NONE 0
285#define CURL_POLL_IN 1
286#define CURL_POLL_OUT 2
287#define CURL_POLL_INOUT 3
288#define CURL_POLL_REMOVE 4
289
290#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
291
292#define CURL_CSELECT_IN 0x01
293#define CURL_CSELECT_OUT 0x02
294#define CURL_CSELECT_ERR 0x04
295
296typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */
297 curl_socket_t s, /* socket */
298 int what, /* see above */
299 void *userp, /* private callback
300 pointer */
301 void *socketp); /* private socket
302 pointer */
303/*
304 * Name: curl_multi_timer_callback
305 *
306 * Desc: Called by libcurl whenever the library detects a change in the
307 * maximum number of milliseconds the app is allowed to wait before
308 * curl_multi_socket() or curl_multi_perform() must be called
309 * (to allow libcurl's timed events to take place).
310 *
311 * Returns: The callback should return zero.
312 */
313typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
314 long timeout_ms, /* see above */
315 void *userp); /* private callback
316 pointer */
317
318CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
319 int *running_handles);
320
321CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
322 curl_socket_t s,
323 int ev_bitmask,
324 int *running_handles);
325
326CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
327 int *running_handles);
328
329#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
330/* This macro below was added in 7.16.3 to push users who recompile to use
331 the new curl_multi_socket_action() instead of the old curl_multi_socket()
332*/
333#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
334#endif
335
336/*
337 * Name: curl_multi_timeout()
338 *
339 * Desc: Returns the maximum number of milliseconds the app is allowed to
340 * wait before curl_multi_socket() or curl_multi_perform() must be
341 * called (to allow libcurl's timed events to take place).
342 *
343 * Returns: CURLM error code.
344 */
345CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
346 long *milliseconds);
347
348typedef enum {
349 /* This is the socket callback function pointer */
350 CURLOPT(CURLMOPT_SOCKETFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 1),
351
352 /* This is the argument passed to the socket callback */
353 CURLOPT(CURLMOPT_SOCKETDATA, CURLOPTTYPE_OBJECTPOINT, 2),
354
355 /* set to 1 to enable pipelining for this multi handle */
356 CURLOPT(CURLMOPT_PIPELINING, CURLOPTTYPE_LONG, 3),
357
358 /* This is the timer callback function pointer */
359 CURLOPT(CURLMOPT_TIMERFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 4),
360
361 /* This is the argument passed to the timer callback */
362 CURLOPT(CURLMOPT_TIMERDATA, CURLOPTTYPE_OBJECTPOINT, 5),
363
364 /* maximum number of entries in the connection cache */
365 CURLOPT(CURLMOPT_MAXCONNECTS, CURLOPTTYPE_LONG, 6),
366
367 /* maximum number of (pipelining) connections to one host */
368 CURLOPT(CURLMOPT_MAX_HOST_CONNECTIONS, CURLOPTTYPE_LONG, 7),
369
370 /* maximum number of requests in a pipeline */
371 CURLOPT(CURLMOPT_MAX_PIPELINE_LENGTH, CURLOPTTYPE_LONG, 8),
372
373 /* a connection with a content-length longer than this
374 will not be considered for pipelining */
375 CURLOPT(CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 9),
376
377 /* a connection with a chunk length longer than this
378 will not be considered for pipelining */
379 CURLOPT(CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 10),
380
381 /* a list of site names(+port) that are blocked from pipelining */
382 CURLOPT(CURLMOPT_PIPELINING_SITE_BL, CURLOPTTYPE_OBJECTPOINT, 11),
383
384 /* a list of server types that are blocked from pipelining */
385 CURLOPT(CURLMOPT_PIPELINING_SERVER_BL, CURLOPTTYPE_OBJECTPOINT, 12),
386
387 /* maximum number of open connections in total */
388 CURLOPT(CURLMOPT_MAX_TOTAL_CONNECTIONS, CURLOPTTYPE_LONG, 13),
389
390 /* This is the server push callback function pointer */
391 CURLOPT(CURLMOPT_PUSHFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 14),
392
393 /* This is the argument passed to the server push callback */
394 CURLOPT(CURLMOPT_PUSHDATA, CURLOPTTYPE_OBJECTPOINT, 15),
395
396 /* maximum number of concurrent streams to support on a connection */
397 CURLOPT(CURLMOPT_MAX_CONCURRENT_STREAMS, CURLOPTTYPE_LONG, 16),
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 */
410CURL_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 */
423CURL_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. It can also decide
432 * to completely fail the connection.
433 *
434 * Returns: CURL_PUSH_OK, CURL_PUSH_DENY or CURL_PUSH_ERROROUT
435 */
436#define CURL_PUSH_OK 0
437#define CURL_PUSH_DENY 1
438#define CURL_PUSH_ERROROUT 2 /* added in 7.72.0 */
439
440struct curl_pushheaders; /* forward declaration only */
441
442CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
443 size_t num);
444CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
445 const char *name);
446
447typedef int (*curl_push_callback)(CURL *parent,
448 CURL *easy,
449 size_t num_headers,
450 struct curl_pushheaders *headers,
451 void *userp);
452
453#ifdef __cplusplus
454} /* end of extern "C" */
455#endif
456
457#endif
458

source code of include/x86_64-linux-gnu/curl/multi.h