1#ifndef CURLINC_MULTI_H
2#define CURLINC_MULTI_H
3/***************************************************************************
4 * _ _ ____ _
5 * Project ___| | | | _ \| |
6 * / __| | | | |_) | |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2020, 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_LAST
78} CURLMcode;
79
80/* just to make code nicer when using curl_multi_socket() you can now check
81 for CURLM_CALL_MULTI_SOCKET too in the same style it works for
82 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
83#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
84
85/* bitmask bits for CURLMOPT_PIPELINING */
86#define CURLPIPE_NOTHING 0L
87#define CURLPIPE_HTTP1 1L
88#define CURLPIPE_MULTIPLEX 2L
89
90typedef enum {
91 CURLMSG_NONE, /* first, not used */
92 CURLMSG_DONE, /* This easy handle has completed. 'result' contains
93 the CURLcode of the transfer */
94 CURLMSG_LAST /* last, not used */
95} CURLMSG;
96
97struct CURLMsg {
98 CURLMSG msg; /* what this message means */
99 CURL *easy_handle; /* the handle it concerns */
100 union {
101 void *whatever; /* message-specific data */
102 CURLcode result; /* return code for transfer */
103 } data;
104};
105typedef struct CURLMsg CURLMsg;
106
107/* Based on poll(2) structure and values.
108 * We don't use pollfd and POLL* constants explicitly
109 * to cover platforms without poll(). */
110#define CURL_WAIT_POLLIN 0x0001
111#define CURL_WAIT_POLLPRI 0x0002
112#define CURL_WAIT_POLLOUT 0x0004
113
114struct curl_waitfd {
115 curl_socket_t fd;
116 short events;
117 short revents; /* not supported yet */
118};
119
120/*
121 * Name: curl_multi_init()
122 *
123 * Desc: inititalize multi-style curl usage
124 *
125 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
126 */
127CURL_EXTERN CURLM *curl_multi_init(void);
128
129/*
130 * Name: curl_multi_add_handle()
131 *
132 * Desc: add a standard curl handle to the multi stack
133 *
134 * Returns: CURLMcode type, general multi error code.
135 */
136CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,
137 CURL *curl_handle);
138
139 /*
140 * Name: curl_multi_remove_handle()
141 *
142 * Desc: removes a curl handle from the multi stack again
143 *
144 * Returns: CURLMcode type, general multi error code.
145 */
146CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
147 CURL *curl_handle);
148
149 /*
150 * Name: curl_multi_fdset()
151 *
152 * Desc: Ask curl for its fd_set sets. The app can use these to select() or
153 * poll() on. We want curl_multi_perform() called as soon as one of
154 * them are ready.
155 *
156 * Returns: CURLMcode type, general multi error code.
157 */
158CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,
159 fd_set *read_fd_set,
160 fd_set *write_fd_set,
161 fd_set *exc_fd_set,
162 int *max_fd);
163
164/*
165 * Name: curl_multi_wait()
166 *
167 * Desc: Poll on all fds within a CURLM set as well as any
168 * additional fds passed to the function.
169 *
170 * Returns: CURLMcode type, general multi error code.
171 */
172CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
173 struct curl_waitfd extra_fds[],
174 unsigned int extra_nfds,
175 int timeout_ms,
176 int *ret);
177
178/*
179 * Name: curl_multi_poll()
180 *
181 * Desc: Poll on all fds within a CURLM set as well as any
182 * additional fds passed to the function.
183 *
184 * Returns: CURLMcode type, general multi error code.
185 */
186CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle,
187 struct curl_waitfd extra_fds[],
188 unsigned int extra_nfds,
189 int timeout_ms,
190 int *ret);
191
192/*
193 * Name: curl_multi_wakeup()
194 *
195 * Desc: wakes up a sleeping curl_multi_poll call.
196 *
197 * Returns: CURLMcode type, general multi error code.
198 */
199CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle);
200
201 /*
202 * Name: curl_multi_perform()
203 *
204 * Desc: When the app thinks there's data available for curl it calls this
205 * function to read/write whatever there is right now. This returns
206 * as soon as the reads and writes are done. This function does not
207 * require that there actually is data available for reading or that
208 * data can be written, it can be called just in case. It returns
209 * the number of handles that still transfer data in the second
210 * argument's integer-pointer.
211 *
212 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
213 * returns errors etc regarding the whole multi stack. There might
214 * still have occurred problems on individual transfers even when
215 * this returns OK.
216 */
217CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
218 int *running_handles);
219
220 /*
221 * Name: curl_multi_cleanup()
222 *
223 * Desc: Cleans up and removes a whole multi stack. It does not free or
224 * touch any individual easy handles in any way. We need to define
225 * in what state those handles will be if this function is called
226 * in the middle of a transfer.
227 *
228 * Returns: CURLMcode type, general multi error code.
229 */
230CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
231
232/*
233 * Name: curl_multi_info_read()
234 *
235 * Desc: Ask the multi handle if there's any messages/informationals from
236 * the individual transfers. Messages include informationals such as
237 * error code from the transfer or just the fact that a transfer is
238 * completed. More details on these should be written down as well.
239 *
240 * Repeated calls to this function will return a new struct each
241 * time, until a special "end of msgs" struct is returned as a signal
242 * that there is no more to get at this point.
243 *
244 * The data the returned pointer points to will not survive calling
245 * curl_multi_cleanup().
246 *
247 * The 'CURLMsg' struct is meant to be very simple and only contain
248 * very basic information. If more involved information is wanted,
249 * we will provide the particular "transfer handle" in that struct
250 * and that should/could/would be used in subsequent
251 * curl_easy_getinfo() calls (or similar). The point being that we
252 * must never expose complex structs to applications, as then we'll
253 * undoubtably get backwards compatibility problems in the future.
254 *
255 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
256 * of structs. It also writes the number of messages left in the
257 * queue (after this read) in the integer the second argument points
258 * to.
259 */
260CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
261 int *msgs_in_queue);
262
263/*
264 * Name: curl_multi_strerror()
265 *
266 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
267 * value into the equivalent human readable error string. This is
268 * useful for printing meaningful error messages.
269 *
270 * Returns: A pointer to a null-terminated error message.
271 */
272CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
273
274/*
275 * Name: curl_multi_socket() and
276 * curl_multi_socket_all()
277 *
278 * Desc: An alternative version of curl_multi_perform() that allows the
279 * application to pass in one of the file descriptors that have been
280 * detected to have "action" on them and let libcurl perform.
281 * See man page for details.
282 */
283#define CURL_POLL_NONE 0
284#define CURL_POLL_IN 1
285#define CURL_POLL_OUT 2
286#define CURL_POLL_INOUT 3
287#define CURL_POLL_REMOVE 4
288
289#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
290
291#define CURL_CSELECT_IN 0x01
292#define CURL_CSELECT_OUT 0x02
293#define CURL_CSELECT_ERR 0x04
294
295typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */
296 curl_socket_t s, /* socket */
297 int what, /* see above */
298 void *userp, /* private callback
299 pointer */
300 void *socketp); /* private socket
301 pointer */
302/*
303 * Name: curl_multi_timer_callback
304 *
305 * Desc: Called by libcurl whenever the library detects a change in the
306 * maximum number of milliseconds the app is allowed to wait before
307 * curl_multi_socket() or curl_multi_perform() must be called
308 * (to allow libcurl's timed events to take place).
309 *
310 * Returns: The callback should return zero.
311 */
312typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
313 long timeout_ms, /* see above */
314 void *userp); /* private callback
315 pointer */
316
317CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
318 int *running_handles);
319
320CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
321 curl_socket_t s,
322 int ev_bitmask,
323 int *running_handles);
324
325CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
326 int *running_handles);
327
328#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
329/* This macro below was added in 7.16.3 to push users who recompile to use
330 the new curl_multi_socket_action() instead of the old curl_multi_socket()
331*/
332#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
333#endif
334
335/*
336 * Name: curl_multi_timeout()
337 *
338 * Desc: Returns the maximum number of milliseconds the app is allowed to
339 * wait before curl_multi_socket() or curl_multi_perform() must be
340 * called (to allow libcurl's timed events to take place).
341 *
342 * Returns: CURLM error code.
343 */
344CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
345 long *milliseconds);
346
347typedef enum {
348 /* This is the socket callback function pointer */
349 CURLOPT(CURLMOPT_SOCKETFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 1),
350
351 /* This is the argument passed to the socket callback */
352 CURLOPT(CURLMOPT_SOCKETDATA, CURLOPTTYPE_OBJECTPOINT, 2),
353
354 /* set to 1 to enable pipelining for this multi handle */
355 CURLOPT(CURLMOPT_PIPELINING, CURLOPTTYPE_LONG, 3),
356
357 /* This is the timer callback function pointer */
358 CURLOPT(CURLMOPT_TIMERFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 4),
359
360 /* This is the argument passed to the timer callback */
361 CURLOPT(CURLMOPT_TIMERDATA, CURLOPTTYPE_OBJECTPOINT, 5),
362
363 /* maximum number of entries in the connection cache */
364 CURLOPT(CURLMOPT_MAXCONNECTS, CURLOPTTYPE_LONG, 6),
365
366 /* maximum number of (pipelining) connections to one host */
367 CURLOPT(CURLMOPT_MAX_HOST_CONNECTIONS, CURLOPTTYPE_LONG, 7),
368
369 /* maximum number of requests in a pipeline */
370 CURLOPT(CURLMOPT_MAX_PIPELINE_LENGTH, CURLOPTTYPE_LONG, 8),
371
372 /* a connection with a content-length longer than this
373 will not be considered for pipelining */
374 CURLOPT(CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 9),
375
376 /* a connection with a chunk length longer than this
377 will not be considered for pipelining */
378 CURLOPT(CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 10),
379
380 /* a list of site names(+port) that are blocked from pipelining */
381 CURLOPT(CURLMOPT_PIPELINING_SITE_BL, CURLOPTTYPE_OBJECTPOINT, 11),
382
383 /* a list of server types that are blocked from pipelining */
384 CURLOPT(CURLMOPT_PIPELINING_SERVER_BL, CURLOPTTYPE_OBJECTPOINT, 12),
385
386 /* maximum number of open connections in total */
387 CURLOPT(CURLMOPT_MAX_TOTAL_CONNECTIONS, CURLOPTTYPE_LONG, 13),
388
389 /* This is the server push callback function pointer */
390 CURLOPT(CURLMOPT_PUSHFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 14),
391
392 /* This is the argument passed to the server push callback */
393 CURLOPT(CURLMOPT_PUSHDATA, CURLOPTTYPE_OBJECTPOINT, 15),
394
395 /* maximum number of concurrent streams to support on a connection */
396 CURLOPT(CURLMOPT_MAX_CONCURRENT_STREAMS, CURLOPTTYPE_LONG, 16),
397
398 CURLMOPT_LASTENTRY /* the last unused */
399} CURLMoption;
400
401
402/*
403 * Name: curl_multi_setopt()
404 *
405 * Desc: Sets options for the multi handle.
406 *
407 * Returns: CURLM error code.
408 */
409CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
410 CURLMoption option, ...);
411
412
413/*
414 * Name: curl_multi_assign()
415 *
416 * Desc: This function sets an association in the multi handle between the
417 * given socket and a private pointer of the application. This is
418 * (only) useful for curl_multi_socket uses.
419 *
420 * Returns: CURLM error code.
421 */
422CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
423 curl_socket_t sockfd, void *sockp);
424
425
426/*
427 * Name: curl_push_callback
428 *
429 * Desc: This callback gets called when a new stream is being pushed by the
430 * server. It approves or denies the new stream. It can also decide
431 * to completely fail the connection.
432 *
433 * Returns: CURL_PUSH_OK, CURL_PUSH_DENY or CURL_PUSH_ERROROUT
434 */
435#define CURL_PUSH_OK 0
436#define CURL_PUSH_DENY 1
437#define CURL_PUSH_ERROROUT 2 /* added in 7.72.0 */
438
439struct curl_pushheaders; /* forward declaration only */
440
441CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
442 size_t num);
443CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
444 const char *name);
445
446typedef int (*curl_push_callback)(CURL *parent,
447 CURL *easy,
448 size_t num_headers,
449 struct curl_pushheaders *headers,
450 void *userp);
451
452#ifdef __cplusplus
453} /* end of extern "C" */
454#endif
455
456#endif
457