1 #ifndef HEADER_CURL_ASYN_H
2 #define HEADER_CURL_ASYN_H
3 /***************************************************************************
5 * Project ___| | | | _ \| |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
10 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
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.
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.
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
23 ***************************************************************************/
25 #include "curl_setup.h"
26 #include "curl_addrinfo.h"
32 struct Curl_dns_entry;
35 * This header defines all functions in the internal asynch resolver interface.
36 * All asynch resolvers need to provide these functions.
37 * asyn-ares.c and asyn-thread.c are the current implementations of asynch
42 * Curl_resolver_global_init()
44 * Called from curl_global_init() to initialize global resolver environment.
45 * Returning anything else than CURLE_OK fails curl_global_init().
47 int Curl_resolver_global_init(void);
50 * Curl_resolver_global_cleanup()
51 * Called from curl_global_cleanup() to destroy global resolver environment.
53 void Curl_resolver_global_cleanup(void);
56 * Curl_resolver_init()
57 * Called from curl_easy_init() -> Curl_open() to initialize resolver
58 * URL-state specific environment ('resolver' member of the UrlState
59 * structure). Should fill the passed pointer by the initialized handler.
60 * Returning anything else than CURLE_OK fails curl_easy_init() with the
63 CURLcode Curl_resolver_init(void **resolver);
66 * Curl_resolver_cleanup()
67 * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver
68 * URL-state specific environment ('resolver' member of the UrlState
69 * structure). Should destroy the handler and free all resources connected to
72 void Curl_resolver_cleanup(void *resolver);
75 * Curl_resolver_duphandle()
76 * Called from curl_easy_duphandle() to duplicate resolver URL-state specific
77 * environment ('resolver' member of the UrlState structure). Should
78 * duplicate the 'from' handle and pass the resulting handle to the 'to'
79 * pointer. Returning anything else than CURLE_OK causes failed
80 * curl_easy_duphandle() call.
82 int Curl_resolver_duphandle(void **to, void *from);
85 * Curl_resolver_cancel().
87 * It is called from inside other functions to cancel currently performing
88 * resolver request. Should also free any temporary resources allocated to
91 void Curl_resolver_cancel(struct connectdata *conn);
93 /* Curl_resolver_getsock()
95 * This function is called from the multi_getsock() function. 'sock' is a
96 * pointer to an array to hold the file descriptors, with 'numsock' being the
97 * size of that array (in number of entries). This function is supposed to
98 * return bitmask indicating what file descriptors (referring to array indexes
99 * in the 'sock' array) to wait for, read/write.
101 int Curl_resolver_getsock(struct connectdata *conn, curl_socket_t *sock,
105 * Curl_resolver_is_resolved()
107 * Called repeatedly to check if a previous name resolve request has
108 * completed. It should also make sure to time-out if the operation seems to
111 * Returns normal CURLcode errors.
113 CURLcode Curl_resolver_is_resolved(struct connectdata *conn,
114 struct Curl_dns_entry **dns);
117 * Curl_resolver_wait_resolv()
119 * waits for a resolve to finish. This function should be avoided since using
120 * this risk getting the multi interface to "hang".
122 * If 'entry' is non-NULL, make it point to the resolved dns entry
124 * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved, and
125 * CURLE_OPERATION_TIMEDOUT if a time-out occurred.
128 CURLcode Curl_resolver_wait_resolv(struct connectdata *conn,
129 struct Curl_dns_entry **dnsentry);
132 * Curl_resolver_getaddrinfo() - when using this resolver
134 * Returns name information about the given hostname and port number. If
135 * successful, the 'hostent' is returned and the forth argument will point to
136 * memory we need to free after use. That memory *MUST* be freed with
137 * Curl_freeaddrinfo(), nothing else.
139 * Each resolver backend must of course make sure to return data in the
140 * correct format to comply with this.
142 Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
143 const char *hostname,
147 #ifndef CURLRES_ASYNCH
148 /* convert these functions if an asynch resolver isn't used */
149 #define Curl_resolver_cancel(x) Curl_nop_stmt
150 #define Curl_resolver_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST
151 #define Curl_resolver_wait_resolv(x,y) CURLE_COULDNT_RESOLVE_HOST
152 #define Curl_resolver_getsock(x,y,z) 0
153 #define Curl_resolver_duphandle(x,y) CURLE_OK
154 #define Curl_resolver_init(x) CURLE_OK
155 #define Curl_resolver_global_init() CURLE_OK
156 #define Curl_resolver_global_cleanup() Curl_nop_stmt
157 #define Curl_resolver_cleanup(x) Curl_nop_stmt
160 #ifdef CURLRES_ASYNCH
161 #define Curl_resolver_asynch() 1
163 #define Curl_resolver_asynch() 0
167 /********** end of generic resolver interface functions *****************/
168 #endif /* HEADER_CURL_ASYN_H */