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_LAST
74} CURLMcode;
75
76/* just to make code nicer when using curl_multi_socket() you can now check
77 for CURLM_CALL_MULTI_SOCKET too in the same style it works for
78 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
79#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
80
81/* bitmask bits for CURLMOPT_PIPELINING */
82#define CURLPIPE_NOTHING 0L
83#define CURLPIPE_HTTP1 1L
84#define CURLPIPE_MULTIPLEX 2L
85
86typedef enum {
87 CURLMSG_NONE, /* first, not used */
88 CURLMSG_DONE, /* This easy handle has completed. 'result' contains
89 the CURLcode of the transfer */
90 CURLMSG_LAST /* last, not used */
91} CURLMSG;
92
93struct CURLMsg {
94 CURLMSG msg; /* what this message means */
95 CURL *easy_handle; /* the handle it concerns */
96 union {
97 void *whatever; /* message-specific data */
98 CURLcode result; /* return code for transfer */
99 } data;
100};
101typedef struct CURLMsg CURLMsg;
102
103/* Based on poll(2) structure and values.
104 * We don't use pollfd and POLL* constants explicitly
105 * to cover platforms without poll(). */
106#define CURL_WAIT_POLLIN 0x0001
107#define CURL_WAIT_POLLPRI 0x0002
108#define CURL_WAIT_POLLOUT 0x0004
109
110struct curl_waitfd {
111 curl_socket_t fd;
112 short events;
113 short revents; /* not supported yet */
114};
115
116/*
117 * Name: curl_multi_init()
118 *
119 * Desc: inititalize multi-style curl usage
120 *
121 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
122 */
123CURL_EXTERN CURLM *curl_multi_init(void);
124
125/*
126 * Name: curl_multi_add_handle()
127 *
128 * Desc: add a standard curl handle to the multi stack
129 *
130 * Returns: CURLMcode type, general multi error code.
131 */
132CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,
133 CURL *curl_handle);
134
135 /*
136 * Name: curl_multi_remove_handle()
137 *
138 * Desc: removes a curl handle from the multi stack again
139 *
140 * Returns: CURLMcode type, general multi error code.
141 */
142CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
143 CURL *curl_handle);
144
145 /*
146 * Name: curl_multi_fdset()
147 *
148 * Desc: Ask curl for its fd_set sets. The app can use these to select() or
149 * poll() on. We want curl_multi_perform() called as soon as one of
150 * them are ready.
151 *
152 * Returns: CURLMcode type, general multi error code.
153 */
154CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,
155 fd_set *read_fd_set,
156 fd_set *write_fd_set,
157 fd_set *exc_fd_set,
158 int *max_fd);
159
160/*
161 * Name: curl_multi_wait()
162 *
163 * Desc: Poll on all fds within a CURLM set as well as any
164 * additional fds passed to the function.
165 *
166 * Returns: CURLMcode type, general multi error code.
167 */
168CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
169 struct curl_waitfd extra_fds[],
170 unsigned int extra_nfds,
171 int timeout_ms,
172 int *ret);
173
174 /*
175 * Name: curl_multi_perform()
176 *
177 * Desc: When the app thinks there's data available for curl it calls this
178 * function to read/write whatever there is right now. This returns
179 * as soon as the reads and writes are done. This function does not
180 * require that there actually is data available for reading or that
181 * data can be written, it can be called just in case. It returns
182 * the number of handles that still transfer data in the second
183 * argument's integer-pointer.
184 *
185 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
186 * returns errors etc regarding the whole multi stack. There might
187 * still have occurred problems on invidual transfers even when this
188 * returns OK.
189 */
190CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
191 int *running_handles);
192
193 /*
194 * Name: curl_multi_cleanup()
195 *
196 * Desc: Cleans up and removes a whole multi stack. It does not free or
197 * touch any individual easy handles in any way. We need to define
198 * in what state those handles will be if this function is called
199 * in the middle of a transfer.
200 *
201 * Returns: CURLMcode type, general multi error code.
202 */
203CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
204
205/*
206 * Name: curl_multi_info_read()
207 *
208 * Desc: Ask the multi handle if there's any messages/informationals from
209 * the individual transfers. Messages include informationals such as
210 * error code from the transfer or just the fact that a transfer is
211 * completed. More details on these should be written down as well.
212 *
213 * Repeated calls to this function will return a new struct each
214 * time, until a special "end of msgs" struct is returned as a signal
215 * that there is no more to get at this point.
216 *
217 * The data the returned pointer points to will not survive calling
218 * curl_multi_cleanup().
219 *
220 * The 'CURLMsg' struct is meant to be very simple and only contain
221 * very basic information. If more involved information is wanted,
222 * we will provide the particular "transfer handle" in that struct
223 * and that should/could/would be used in subsequent
224 * curl_easy_getinfo() calls (or similar). The point being that we
225 * must never expose complex structs to applications, as then we'll
226 * undoubtably get backwards compatibility problems in the future.
227 *
228 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
229 * of structs. It also writes the number of messages left in the
230 * queue (after this read) in the integer the second argument points
231 * to.
232 */
233CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
234 int *msgs_in_queue);
235
236/*
237 * Name: curl_multi_strerror()
238 *
239 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
240 * value into the equivalent human readable error string. This is
241 * useful for printing meaningful error messages.
242 *
243 * Returns: A pointer to a zero-terminated error message.
244 */
245CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
246
247/*
248 * Name: curl_multi_socket() and
249 * curl_multi_socket_all()
250 *
251 * Desc: An alternative version of curl_multi_perform() that allows the
252 * application to pass in one of the file descriptors that have been
253 * detected to have "action" on them and let libcurl perform.
254 * See man page for details.
255 */
256#define CURL_POLL_NONE 0
257#define CURL_POLL_IN 1
258#define CURL_POLL_OUT 2
259#define CURL_POLL_INOUT 3
260#define CURL_POLL_REMOVE 4
261
262#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
263
264#define CURL_CSELECT_IN 0x01
265#define CURL_CSELECT_OUT 0x02
266#define CURL_CSELECT_ERR 0x04
267
268typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */
269 curl_socket_t s, /* socket */
270 int what, /* see above */
271 void *userp, /* private callback
272 pointer */
273 void *socketp); /* private socket
274 pointer */
275/*
276 * Name: curl_multi_timer_callback
277 *
278 * Desc: Called by libcurl whenever the library detects a change in the
279 * maximum number of milliseconds the app is allowed to wait before
280 * curl_multi_socket() or curl_multi_perform() must be called
281 * (to allow libcurl's timed events to take place).
282 *
283 * Returns: The callback should return zero.
284 */
285typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */
286 long timeout_ms, /* see above */
287 void *userp); /* private callback
288 pointer */
289
290CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
291 int *running_handles);
292
293CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
294 curl_socket_t s,
295 int ev_bitmask,
296 int *running_handles);
297
298CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
299 int *running_handles);
300
301#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
302/* This macro below was added in 7.16.3 to push users who recompile to use
303 the new curl_multi_socket_action() instead of the old curl_multi_socket()
304*/
305#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
306#endif
307
308/*
309 * Name: curl_multi_timeout()
310 *
311 * Desc: Returns the maximum number of milliseconds the app is allowed to
312 * wait before curl_multi_socket() or curl_multi_perform() must be
313 * called (to allow libcurl's timed events to take place).
314 *
315 * Returns: CURLM error code.
316 */
317CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
318 long *milliseconds);
319
320#undef CINIT /* re-using the same name as in curl.h */
321
322#ifdef CURL_ISOCPP
323#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
324#else
325/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
326#define LONG CURLOPTTYPE_LONG
327#define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT
328#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
329#define OFF_T CURLOPTTYPE_OFF_T
330#define CINIT(name,type,number) CURLMOPT_/**/name = type + number
331#endif
332
333typedef enum {
334 /* This is the socket callback function pointer */
335 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1),
336
337 /* This is the argument passed to the socket callback */
338 CINIT(SOCKETDATA, OBJECTPOINT, 2),
339
340 /* set to 1 to enable pipelining for this multi handle */
341 CINIT(PIPELINING, LONG, 3),
342
343 /* This is the timer callback function pointer */
344 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4),
345
346 /* This is the argument passed to the timer callback */
347 CINIT(TIMERDATA, OBJECTPOINT, 5),
348
349 /* maximum number of entries in the connection cache */
350 CINIT(MAXCONNECTS, LONG, 6),
351
352 /* maximum number of (pipelining) connections to one host */
353 CINIT(MAX_HOST_CONNECTIONS, LONG, 7),
354
355 /* maximum number of requests in a pipeline */
356 CINIT(MAX_PIPELINE_LENGTH, LONG, 8),
357
358 /* a connection with a content-length longer than this
359 will not be considered for pipelining */
360 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9),
361
362 /* a connection with a chunk length longer than this
363 will not be considered for pipelining */
364 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10),
365
366 /* a list of site names(+port) that are blacklisted from
367 pipelining */
368 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11),
369
370 /* a list of server types that are blacklisted from
371 pipelining */
372 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12),
373
374 /* maximum number of open connections in total */
375 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13),
376
377 /* This is the server push callback function pointer */
378 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14),
379
380 /* This is the argument passed to the server push callback */
381 CINIT(PUSHDATA, OBJECTPOINT, 15),
382
383 CURLMOPT_LASTENTRY /* the last unused */
384} CURLMoption;
385
386
387/*
388 * Name: curl_multi_setopt()
389 *
390 * Desc: Sets options for the multi handle.
391 *
392 * Returns: CURLM error code.
393 */
394CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
395 CURLMoption option, ...);
396
397
398/*
399 * Name: curl_multi_assign()
400 *
401 * Desc: This function sets an association in the multi handle between the
402 * given socket and a private pointer of the application. This is
403 * (only) useful for curl_multi_socket uses.
404 *
405 * Returns: CURLM error code.
406 */
407CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
408 curl_socket_t sockfd, void *sockp);
409
410
411/*
412 * Name: curl_push_callback
413 *
414 * Desc: This callback gets called when a new stream is being pushed by the
415 * server. It approves or denies the new stream.
416 *
417 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY.
418 */
419#define CURL_PUSH_OK 0
420#define CURL_PUSH_DENY 1
421
422struct curl_pushheaders; /* forward declaration only */
423
424CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
425 size_t num);
426CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
427 const char *name);
428
429typedef int (*curl_push_callback)(CURL *parent,
430 CURL *easy,
431 size_t num_headers,
432 struct curl_pushheaders *headers,
433 void *userp);
434
435#ifdef __cplusplus
436} /* end of extern "C" */
437#endif
438
439#endif
440