1#ifndef __CURL_MULTI_H
2#define __CURL_MULTI_H
3/***************************************************************************
4 * _ _ ____ _
5 * Project ___| | | | _ \| |
6 * / __| | | | |_) | |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2017, 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_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
88typedef 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
95struct 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};
103typedef 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
112struct 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 */
125CURL_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 */
134CURL_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 */
144CURL_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 */
156CURL_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 */
170CURL_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_perform()
178 *
179 * Desc: When the app thinks there's data available for curl it calls this
180 * function to read/write whatever there is right now. This returns
181 * as soon as the reads and writes are done. This function does not
182 * require that there actually is data available for reading or that
183 * data can be written, it can be called just in case. It returns
184 * the number of handles that still transfer data in the second
185 * argument's integer-pointer.
186 *
187 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
188 * returns errors etc regarding the whole multi stack. There might
189 * still have occurred problems on individual transfers even when
190 * this returns OK.
191 */
192CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
193 int *running_handles);
194
195 /*
196 * Name: curl_multi_cleanup()
197 *
198 * Desc: Cleans up and removes a whole multi stack. It does not free or
199 * touch any individual easy handles in any way. We need to define
200 * in what state those handles will be if this function is called
201 * in the middle of a transfer.
202 *
203 * Returns: CURLMcode type, general multi error code.
204 */
205CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
206
207/*
208 * Name: curl_multi_info_read()
209 *
210 * Desc: Ask the multi handle if there's any messages/informationals from
211 * the individual transfers. Messages include informationals such as
212 * error code from the transfer or just the fact that a transfer is
213 * completed. More details on these should be written down as well.
214 *
215 * Repeated calls to this function will return a new struct each
216 * time, until a special "end of msgs" struct is returned as a signal
217 * that there is no more to get at this point.
218 *
219 * The data the returned pointer points to will not survive calling
220 * curl_multi_cleanup().
221 *
222 * The 'CURLMsg' struct is meant to be very simple and only contain
223 * very basic information. If more involved information is wanted,
224 * we will provide the particular "transfer handle" in that struct
225 * and that should/could/would be used in subsequent
226 * curl_easy_getinfo() calls (or similar). The point being that we
227 * must never expose complex structs to applications, as then we'll
228 * undoubtably get backwards compatibility problems in the future.
229 *
230 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
231 * of structs. It also writes the number of messages left in the
232 * queue (after this read) in the integer the second argument points
233 * to.
234 */
235CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
236 int *msgs_in_queue);
237
238/*
239 * Name: curl_multi_strerror()
240 *
241 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
242 * value into the equivalent human readable error string. This is
243 * useful for printing meaningful error messages.
244 *
245 * Returns: A pointer to a zero-terminated error message.
246 */
247CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
248
249/*
250 * Name: curl_multi_socket() and
251 * curl_multi_socket_all()
252 *
253 * Desc: An alternative version of curl_multi_perform() that allows the
254 * application to pass in one of the file descriptors that have been
255 * detected to have "action" on them and let libcurl perform.
256 * See man page for details.
257 */
258#define CURL_POLL_NONE 0
259#define CURL_POLL_IN 1
260#define CURL_POLL_OUT 2
261#define CURL_POLL_INOUT 3
262#define CURL_POLL_REMOVE 4
263
264#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
265
266#define CURL_CSELECT_IN 0x01
267#define CURL_CSELECT_OUT 0x02
268#define CURL_CSELECT_ERR 0x04
269
270typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */
271 curl_socket_t s, /* socket */
272 int what, /* see above */
273 void *userp, /* private callback
274 pointer */
275 void *socketp); /* private socket
276 pointer */
277/*
278 * Name: curl_multi_timer_callback
279 *
280 * Desc: Called by libcurl whenever the library detects a change in the
281 * maximum number of milliseconds the app is allowed to wait before
282 * curl_multi_socket() or curl_multi_perform() must be called
283 * (to allow libcurl's timed events to take place).
284 *
285 * Returns: The callback should return zero.
286 */
287typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
288 long timeout_ms, /* see above */
289 void *userp); /* private callback
290 pointer */
291
292CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
293 int *running_handles);
294
295CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
296 curl_socket_t s,
297 int ev_bitmask,
298 int *running_handles);
299
300CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
301 int *running_handles);
302
303#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
304/* This macro below was added in 7.16.3 to push users who recompile to use
305 the new curl_multi_socket_action() instead of the old curl_multi_socket()
306*/
307#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
308#endif
309
310/*
311 * Name: curl_multi_timeout()
312 *
313 * Desc: Returns the maximum number of milliseconds the app is allowed to
314 * wait before curl_multi_socket() or curl_multi_perform() must be
315 * called (to allow libcurl's timed events to take place).
316 *
317 * Returns: CURLM error code.
318 */
319CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
320 long *milliseconds);
321
322#undef CINIT /* re-using the same name as in curl.h */
323
324#ifdef CURL_ISOCPP
325#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
326#else
327/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
328#define LONG CURLOPTTYPE_LONG
329#define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT
330#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
331#define OFF_T CURLOPTTYPE_OFF_T
332#define CINIT(name,type,number) CURLMOPT_/**/name = type + number
333#endif
334
335typedef enum {
336 /* This is the socket callback function pointer */
337 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1),
338
339 /* This is the argument passed to the socket callback */
340 CINIT(SOCKETDATA, OBJECTPOINT, 2),
341
342 /* set to 1 to enable pipelining for this multi handle */
343 CINIT(PIPELINING, LONG, 3),
344
345 /* This is the timer callback function pointer */
346 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4),
347
348 /* This is the argument passed to the timer callback */
349 CINIT(TIMERDATA, OBJECTPOINT, 5),
350
351 /* maximum number of entries in the connection cache */
352 CINIT(MAXCONNECTS, LONG, 6),
353
354 /* maximum number of (pipelining) connections to one host */
355 CINIT(MAX_HOST_CONNECTIONS, LONG, 7),
356
357 /* maximum number of requests in a pipeline */
358 CINIT(MAX_PIPELINE_LENGTH, LONG, 8),
359
360 /* a connection with a content-length longer than this
361 will not be considered for pipelining */
362 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9),
363
364 /* a connection with a chunk length longer than this
365 will not be considered for pipelining */
366 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10),
367
368 /* a list of site names(+port) that are blacklisted from
369 pipelining */
370 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11),
371
372 /* a list of server types that are blacklisted from
373 pipelining */
374 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12),
375
376 /* maximum number of open connections in total */
377 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13),
378
379 /* This is the server push callback function pointer */
380 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14),
381
382 /* This is the argument passed to the server push callback */
383 CINIT(PUSHDATA, OBJECTPOINT, 15),
384
385 CURLMOPT_LASTENTRY /* the last unused */
386} CURLMoption;
387
388
389/*
390 * Name: curl_multi_setopt()
391 *
392 * Desc: Sets options for the multi handle.
393 *
394 * Returns: CURLM error code.
395 */
396CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
397 CURLMoption option, ...);
398
399
400/*
401 * Name: curl_multi_assign()
402 *
403 * Desc: This function sets an association in the multi handle between the
404 * given socket and a private pointer of the application. This is
405 * (only) useful for curl_multi_socket uses.
406 *
407 * Returns: CURLM error code.
408 */
409CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
410 curl_socket_t sockfd, void *sockp);
411
412
413/*
414 * Name: curl_push_callback
415 *
416 * Desc: This callback gets called when a new stream is being pushed by the
417 * server. It approves or denies the new stream.
418 *
419 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY.
420 */
421#define CURL_PUSH_OK 0
422#define CURL_PUSH_DENY 1
423
424struct curl_pushheaders; /* forward declaration only */
425
426CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
427 size_t num);
428CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
429 const char *name);
430
431typedef int (*curl_push_callback)(CURL *parent,
432 CURL *easy,
433 size_t num_headers,
434 struct curl_pushheaders *headers,
435 void *userp);
436
437#ifdef __cplusplus
438} /* end of extern "C" */
439#endif
440
441#endif
442