• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 #ifndef __CURL_MULTI_H
2 #define __CURL_MULTI_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2016, 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
52 extern "C" {
53 #endif
54 
55 #if defined(BUILDING_LIBCURL) || defined(CURL_STRICTER)
56 typedef struct Curl_multi CURLM;
57 #else
58 typedef void CURLM;
59 #endif
60 
61 typedef 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 
86 typedef 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 
93 struct 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 };
101 typedef 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 
110 struct 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  */
123 CURL_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  */
132 CURL_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   */
142 CURL_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   */
154 CURL_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  */
168 CURL_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   */
190 CURL_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   */
203 CURL_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 informations. 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  */
233 CURL_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  */
245 CURL_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 
268 typedef 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  */
285 typedef int (*curl_multi_timer_callback)(CURLM *multi,    /* multi handle */
286                                          long timeout_ms, /* see above */
287                                          void *userp);    /* private callback
288                                                              pointer */
289 
290 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
291                                         int *running_handles);
292 
293 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
294                                                curl_socket_t s,
295                                                int ev_bitmask,
296                                                int *running_handles);
297 
298 CURL_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  */
317 CURL_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 
333 typedef 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  */
394 CURL_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  */
407 CURL_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 
422 struct curl_pushheaders;  /* forward declaration only */
423 
424 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h,
425                                         size_t num);
426 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h,
427                                          const char *name);
428 
429 typedef 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