1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
#ifndef HEADER_CURL_ASYN_H
#define HEADER_CURL_ASYN_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#include "curl_addrinfo.h"
struct addrinfo;
struct hostent;
struct Curl_easy;
struct connectdata;
struct Curl_dns_entry;
/*
* This header defines all functions in the internal asynch resolver interface.
* All asynch resolvers need to provide these functions.
* asyn-ares.c and asyn-thread.c are the current implementations of asynch
* resolver backends.
*/
/*
* Curl_resolver_global_init()
*
* Called from curl_global_init() to initialize global resolver environment.
* Returning anything else than CURLE_OK fails curl_global_init().
*/
int Curl_resolver_global_init(void);
/*
* Curl_resolver_global_cleanup()
* Called from curl_global_cleanup() to destroy global resolver environment.
*/
void Curl_resolver_global_cleanup(void);
/*
* Curl_resolver_init()
* Called from curl_easy_init() -> Curl_open() to initialize resolver
* URL-state specific environment ('resolver' member of the UrlState
* structure). Should fill the passed pointer by the initialized handler.
* Returning anything else than CURLE_OK fails curl_easy_init() with the
* correspondent code.
*/
CURLcode Curl_resolver_init(struct Curl_easy *easy, void **resolver);
/*
* Curl_resolver_cleanup()
* Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver
* URL-state specific environment ('resolver' member of the UrlState
* structure). Should destroy the handler and free all resources connected to
* it.
*/
void Curl_resolver_cleanup(void *resolver);
/*
* Curl_resolver_duphandle()
* Called from curl_easy_duphandle() to duplicate resolver URL-state specific
* environment ('resolver' member of the UrlState structure). Should
* duplicate the 'from' handle and pass the resulting handle to the 'to'
* pointer. Returning anything else than CURLE_OK causes failed
* curl_easy_duphandle() call.
*/
CURLcode Curl_resolver_duphandle(struct Curl_easy *easy, void **to,
void *from);
/*
* Curl_resolver_cancel().
*
* It is called from inside other functions to cancel currently performing
* resolver request. Should also free any temporary resources allocated to
* perform a request. This never waits for resolver threads to complete.
*
* It is safe to call this when conn is in any state.
*/
void Curl_resolver_cancel(struct connectdata *conn);
/*
* Curl_resolver_kill().
*
* This acts like Curl_resolver_cancel() except it will block until any threads
* associated with the resolver are complete. This never blocks for resolvers
* that do not use threads. This is intended to be the "last chance" function
* that cleans up an in-progress resolver completely (before its owner is about
* to die).
*
* It is safe to call this when conn is in any state.
*/
void Curl_resolver_kill(struct connectdata *conn);
/* Curl_resolver_getsock()
*
* This function is called from the multi_getsock() function. 'sock' is a
* pointer to an array to hold the file descriptors, with 'numsock' being the
* size of that array (in number of entries). This function is supposed to
* return bitmask indicating what file descriptors (referring to array indexes
* in the 'sock' array) to wait for, read/write.
*/
int Curl_resolver_getsock(struct connectdata *conn, curl_socket_t *sock);
/*
* Curl_resolver_is_resolved()
*
* Called repeatedly to check if a previous name resolve request has
* completed. It should also make sure to time-out if the operation seems to
* take too long.
*
* Returns normal CURLcode errors.
*/
CURLcode Curl_resolver_is_resolved(struct connectdata *conn,
struct Curl_dns_entry **dns);
/*
* Curl_resolver_wait_resolv()
*
* Waits for a resolve to finish. This function should be avoided since using
* this risk getting the multi interface to "hang".
*
* If 'entry' is non-NULL, make it point to the resolved dns entry
*
* Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved,
* CURLE_OPERATION_TIMEDOUT if a time-out occurred, or other errors.
*/
CURLcode Curl_resolver_wait_resolv(struct connectdata *conn,
struct Curl_dns_entry **dnsentry);
/*
* Curl_resolver_getaddrinfo() - when using this resolver
*
* Returns name information about the given hostname and port number. If
* successful, the 'hostent' is returned and the forth argument will point to
* memory we need to free after use. That memory *MUST* be freed with
* Curl_freeaddrinfo(), nothing else.
*
* Each resolver backend must of course make sure to return data in the
* correct format to comply with this.
*/
struct Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
const char *hostname,
int port,
int *waitp);
#ifndef CURLRES_ASYNCH
/* convert these functions if an asynch resolver isn't used */
#define Curl_resolver_cancel(x) Curl_nop_stmt
#define Curl_resolver_kill(x) Curl_nop_stmt
#define Curl_resolver_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST
#define Curl_resolver_wait_resolv(x,y) CURLE_COULDNT_RESOLVE_HOST
#define Curl_resolver_duphandle(x,y,z) CURLE_OK
#define Curl_resolver_init(x,y) CURLE_OK
#define Curl_resolver_global_init() CURLE_OK
#define Curl_resolver_global_cleanup() Curl_nop_stmt
#define Curl_resolver_cleanup(x) Curl_nop_stmt
#endif
#ifdef CURLRES_ASYNCH
#define Curl_resolver_asynch() 1
#else
#define Curl_resolver_asynch() 0
#endif
/********** end of generic resolver interface functions *****************/
#endif /* HEADER_CURL_ASYN_H */
|
