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
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_LAST
77} CURLMcode;
78
79/* just to make code nicer when using curl_multi_socket() you can now check
80 for CURLM_CALL_MULTI_SOCKET too in the same style it works for
81 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
82#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
83
84/* bitmask bits for CURLMOPT_PIPELINING */
85#define CURLPIPE_NOTHING 0L
86#define CURLPIPE_HTTP1 1L
87#define CURLPIPE_MULTIPLEX 2L
88
89typedef enum {
90 CURLMSG_NONE, /* first, not used */
91 CURLMSG_DONE, /* This easy handle has completed. 'result' contains
92 the CURLcode of the transfer */
93 CURLMSG_LAST /* last, not used */
94} CURLMSG;
95
96struct CURLMsg {
97 CURLMSG msg; /* what this message means */
98 CURL *easy_handle; /* the handle it concerns */
99 union {
100 void *whatever; /* message-specific data */
101 CURLcode result; /* return code for transfer */
102 } data;
103};
104typedef struct CURLMsg CURLMsg;
105
106/* Based on poll(2) structure and values.
107 * We don't use pollfd and POLL* constants explicitly
108 * to cover platforms without poll(). */
109#define CURL_WAIT_POLLIN 0x0001
110#define CURL_WAIT_POLLPRI 0x0002
111#define CURL_WAIT_POLLOUT 0x0004
112
113struct curl_waitfd {
114 curl_socket_t fd;
115 short events;
116 short revents; /* not supported yet */
117};
118
119/*
120 * Name: curl_multi_init()
121 *
122 * Desc: inititalize multi-style curl usage
123 *
124 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
125 */
126CURL_EXTERN CURLM *curl_multi_init(void);
127
128/*
129 * Name: curl_multi_add_handle()
130 *
131 * Desc: add a standard curl handle to the multi stack
132 *
133 * Returns: CURLMcode type, general multi error code.
134 */
135CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,
136 CURL *curl_handle);
137
138 /*
139 * Name: curl_multi_remove_handle()
140 *
141 * Desc: removes a curl handle from the multi stack again
142 *
143 * Returns: CURLMcode type, general multi error code.
144 */
145CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
146 CURL *curl_handle);
147
148 /*
149 * Name: curl_multi_fdset()
150 *
151 * Desc: Ask curl for its fd_set sets. The app can use these to select() or
152 * poll() on. We want curl_multi_perform() called as soon as one of
153 * them are ready.
154 *
155 * Returns: CURLMcode type, general multi error code.
156 */
157CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,
158 fd_set *read_fd_set,
159 fd_set *write_fd_set,
160 fd_set *exc_fd_set,
161 int *max_fd);
162
163/*
164 * Name: curl_multi_wait()
165 *
166 * Desc: Poll on all fds within a CURLM set as well as any
167 * additional fds passed to the function.
168 *
169 * Returns: CURLMcode type, general multi error code.
170 */
171CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
172 struct curl_waitfd extra_fds[],
173 unsigned int extra_nfds,
174 int timeout_ms,
175 int *ret);
176
177/*
178 * Name: curl_multi_poll()
179 *
180 * Desc: Poll on all fds within a CURLM set as well as any
181 * additional fds passed to the function.
182 *
183 * Returns: CURLMcode type, general multi error code.
184 */
185CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle,
186 struct curl_waitfd extra_fds[],
187 unsigned int extra_nfds,
188 int timeout_ms,
189 int *ret);
190
191/*
192 * Name: curl_multi_wakeup()
193 *
194 * Desc: wakes up a sleeping curl_multi_poll call.
195 *
196 * Returns: CURLMcode type, general multi error code.
197 */
198CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle);
199
200 /*
201 * Name: curl_multi_perform()
202 *
203 * Desc: When the app thinks there's data available for curl it calls this
204 * function to read/write whatever there is right now. This returns
205 * as soon as the reads and writes are done. This function does not
206 * require that there actually is data available for reading or that
207 * data can be written, it can be called just in case. It returns
208 * the number of handles that still transfer data in the second
209 * argument's integer-pointer.
210 *
211 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
212 * returns errors etc regarding the whole multi stack. There might
213 * still have occurred problems on individual transfers even when
214 * this returns OK.
215 */
216CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
217 int *running_handles);
218
219 /*
220 * Name: curl_multi_cleanup()
221 *
222 * Desc: Cleans up and removes a whole multi stack. It does not free or
223 * touch any individual easy handles in any way. We need to define
224 * in what state those handles will be if this function is called
225 * in the middle of a transfer.
226 *
227 * Returns: CURLMcode type, general multi error code.
228 */
229CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
230
231/*
232 * Name: curl_multi_info_read()
233 *
234 * Desc: Ask the multi handle if there's any messages/informationals from
235 * the individual transfers. Messages include informationals such as
236 * error code from the transfer or just the fact that a transfer is
237 * completed. More details on these should be written down as well.
238 *
239 * Repeated calls to this function will return a new struct each
240 * time, until a special "end of msgs" struct is returned as a signal
241 * that there is no more to get at this point.
242 *
243 * The data the returned pointer points to will not survive calling
244 * curl_multi_cleanup().
245 *
246 * The 'CURLMsg' struct is meant to be very simple and only contain
247 * very basic information. If more involved information is wanted,
248 * we will provide the particular "transfer handle" in that struct
249 * and that should/could/would be used in subsequent
250 * curl_easy_getinfo() calls (or similar). The point being that we
251 * must never expose complex structs to applications, as then we'll
252 * undoubtably get backwards compatibility problems in the future.
253 *
254 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
255 * of structs. It also writes the number of messages left in the
256 * queue (after this read) in the integer the second argument points
257 * to.
258 */
259CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
260 int *msgs_in_queue);
261
262/*
263 * Name: curl_multi_strerror()
264 *
265 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
266 * value into the equivalent human readable error string. This is
267 * useful for printing meaningful error messages.
268 *
269 * Returns: A pointer to a zero-terminated error message.
270 */
271CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
272
273/*
274 * Name: curl_multi_socket() and
275 * curl_multi_socket_all()
276 *
277 * Desc: An alternative version of curl_multi_perform() that allows the
278 * application to pass in one of the file descriptors that have been
279 * detected to have "action" on them and let libcurl perform.
280 * See man page for details.
281 */
282#define CURL_POLL_NONE 0
283#define CURL_POLL_IN 1
284#define CURL_POLL_OUT 2
285#define CURL_POLL_INOUT 3
286#define CURL_POLL_REMOVE 4
287
288#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
289
290#define CURL_CSELECT_IN 0x01
291#define CURL_CSELECT_OUT 0x02
292#define CURL_CSELECT_ERR 0x04
293
294typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */
295 curl_socket_t s, /* socket */
296 int what, /* see above */
297 void *userp, /* private callback
298 pointer */
299 void *socketp); /* private socket
300 pointer */
301/*
302 * Name: curl_multi_timer_callback
303 *
304 * Desc: Called by libcurl whenever the library detects a change in the
305 * maximum number of milliseconds the app is allowed to wait before
306 * curl_multi_socket() or curl_multi_perform() must be called
307 * (to allow libcurl's timed events to take place).
308 *
309 * Returns: The callback should return zero.
310 */
311typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
312 long timeout_ms, /* see above */
313 void *userp); /* private callback
314 pointer */
315
316CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
317 int *running_handles);
318
319CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
320 curl_socket_t s,
321 int ev_bitmask,
322 int *running_handles);
323
324CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
325 int *running_handles);
326
327#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
328/* This macro below was added in 7.16.3 to push users who recompile to use
329 the new curl_multi_socket_action() instead of the old curl_multi_socket()
330*/
331#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
332#endif
333
334/*
335 * Name: curl_multi_timeout()
336 *
337 * Desc: Returns the maximum number of milliseconds the app is allowed to
338 * wait before curl_multi_socket() or curl_multi_perform() must be
339 * called (to allow libcurl's timed events to take place).
340 *
341 * Returns: CURLM error code.
342 */
343CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
344 long *milliseconds);
345
346#undef CINIT /* re-using the same name as in curl.h */
347
348#ifdef CURL_ISOCPP
349#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
350#else
351/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
352#define LONG CURLOPTTYPE_LONG
353#define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT
354#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
355#define OFF_T CURLOPTTYPE_OFF_T
356#define CINIT(name,type,number) CURLMOPT_/**/name = type + number
357#endif
358
359typedef enum {
360 /* This is the socket callback function pointer */
361 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1),
362
363 /* This is the argument passed to the socket callback */
364 CINIT(SOCKETDATA, OBJECTPOINT, 2),
365
366 /* set to 1 to enable pipelining for this multi handle */
367 CINIT(PIPELINING, LONG, 3),
368
369 /* This is the timer callback function pointer */
370 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4),
371
372 /* This is the argument passed to the timer callback */
373 CINIT(TIMERDATA, OBJECTPOINT, 5),
374
375 /* maximum number of entries in the connection cache */
376 CINIT(MAXCONNECTS, LONG, 6),
377
378 /* maximum number of (pipelining) connections to one host */
379 CINIT(MAX_HOST_CONNECTIONS, LONG, 7),
380
381 /* maximum number of requests in a pipeline */
382 CINIT(MAX_PIPELINE_LENGTH, LONG, 8),
383
384 /* a connection with a content-length longer than this
385 will not be considered for pipelining */
386 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9),
387
388 /* a connection with a chunk length longer than this
389 will not be considered for pipelining */
390 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10),
391
392 /* a list of site names(+port) that are blacklisted from
393 pipelining */
394 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11),
395
396 /* a list of server types that are blacklisted from
397 pipelining */
398 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12),
399
400 /* maximum number of open connections in total */
401 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13),
402
403 /* This is the server push callback function pointer */
404 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14),
405
406 /* This is the argument passed to the server push callback */
407 CINIT(PUSHDATA, OBJECTPOINT, 15),
408
409 /* maximum number of concurrent streams to support on a connection */
410 CINIT(MAX_CONCURRENT_STREAMS, LONG, 16),
411
412 CURLMOPT_LASTENTRY /* the last unused */
413} CURLMoption;
414
415
416/*
417 * Name: curl_multi_setopt()
418 *
419 * Desc: Sets options for the multi handle.
420 *
421 * Returns: CURLM error code.
422 */
423CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
424 CURLMoption option, ...);
425
426
427/*
428 * Name: curl_multi_assign()
429 *
430 * Desc: This function sets an association in the multi handle between the
431 * given socket and a private pointer of the application. This is
432 * (only) useful for curl_multi_socket uses.
433 *
434 * Returns: CURLM error code.
435 */
436CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
437 curl_socket_t sockfd, void *sockp);
438
439
440/*
441 * Name: curl_push_callback
442 *
443 * Desc: This callback gets called when a new stream is being pushed by the
444 * server. It approves or denies the new stream.
445 *
446 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY.
447 */
448#define CURL_PUSH_OK 0
449#define CURL_PUSH_DENY 1
450
451struct curl_pushheaders; /* forward declaration only */
452
453CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
454 size_t num);
455CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
456 const char *name);
457
458typedef int (*curl_push_callback)(CURL *parent,
459 CURL *easy,
460 size_t num_headers,
461 struct curl_pushheaders *headers,
462 void *userp);
463
464/* value for MAXIMUM CONCURRENT STREAMS upper limit */
465#define INITIAL_MAX_CONCURRENT_STREAMS ((1U << 31) - 1)
466
467#ifdef __cplusplus
468} /* end of extern "C" */
469#endif
470
471#endif
472