1
2 /* Copyright 1998 by the Massachusetts Institute of Technology.
3 * Copyright (C) 2004-2009 by Daniel Stenberg
4 *
5 * Permission to use, copy, modify, and distribute this
6 * software and its documentation for any purpose and without
7 * fee is hereby granted, provided that the above copyright
8 * notice appear in all copies and that both that copyright
9 * notice and this permission notice appear in supporting
10 * documentation, and that the name of M.I.T. not be used in
11 * advertising or publicity pertaining to distribution of the
12 * software without specific, written prior permission.
13 * M.I.T. makes no representations about the suitability of
14 * this software for any purpose. It is provided "as is"
15 * without express or implied warranty.
16 */
17
18 #include "ares_setup.h"
19
20 #include "ares.h"
21 #include "ares_library_init.h"
22 #include "ares_private.h"
23
24 /* library-private global and unique instance vars */
25
26 #ifdef USE_WINSOCK
27 fpGetNetworkParams_t ares_fpGetNetworkParams = ZERO_NULL;
28 fpSystemFunction036_t ares_fpSystemFunction036 = ZERO_NULL;
29 fpGetAdaptersAddresses_t ares_fpGetAdaptersAddresses = ZERO_NULL;
30 #endif
31
32 /* library-private global vars with source visibility restricted to this file */
33
34 static unsigned int ares_initialized;
35 static int ares_init_flags;
36
37 #ifdef USE_WINSOCK
38 static HMODULE hnd_iphlpapi;
39 static HMODULE hnd_advapi32;
40 #endif
41
42
ares_win32_init(void)43 static int ares_win32_init(void)
44 {
45 #ifdef USE_WINSOCK
46
47 hnd_iphlpapi = 0;
48 hnd_iphlpapi = LoadLibrary("iphlpapi.dll");
49 if (!hnd_iphlpapi)
50 return ARES_ELOADIPHLPAPI;
51
52 ares_fpGetNetworkParams = (fpGetNetworkParams_t)
53 GetProcAddress(hnd_iphlpapi, "GetNetworkParams");
54 if (!ares_fpGetNetworkParams)
55 {
56 FreeLibrary(hnd_iphlpapi);
57 return ARES_EADDRGETNETWORKPARAMS;
58 }
59
60 ares_fpGetAdaptersAddresses = (fpGetAdaptersAddresses_t)
61 GetProcAddress(hnd_iphlpapi, "GetAdaptersAddresses");
62 if (!ares_fpGetAdaptersAddresses)
63 {
64 /* This can happen on clients before WinXP, I don't
65 think it should be an error, unless we don't want to
66 support Windows 2000 anymore */
67 }
68
69 /*
70 * When advapi32.dll is unavailable or advapi32.dll has no SystemFunction036,
71 * also known as RtlGenRandom, which is the case for Windows versions prior
72 * to WinXP then c-ares uses portable rand() function. Then don't error here.
73 */
74
75 hnd_advapi32 = 0;
76 hnd_advapi32 = LoadLibrary("advapi32.dll");
77 if (hnd_advapi32)
78 {
79 ares_fpSystemFunction036 = (fpSystemFunction036_t)
80 GetProcAddress(hnd_advapi32, "SystemFunction036");
81 }
82
83 #endif
84 return ARES_SUCCESS;
85 }
86
87
ares_win32_cleanup(void)88 static void ares_win32_cleanup(void)
89 {
90 #ifdef USE_WINSOCK
91 if (hnd_advapi32)
92 FreeLibrary(hnd_advapi32);
93 if (hnd_iphlpapi)
94 FreeLibrary(hnd_iphlpapi);
95 #endif
96 }
97
98
ares_library_init(int flags)99 int ares_library_init(int flags)
100 {
101 int res;
102
103 if (ares_initialized)
104 return ARES_SUCCESS;
105 ares_initialized++;
106
107 if (flags & ARES_LIB_INIT_WIN32)
108 {
109 res = ares_win32_init();
110 if (res != ARES_SUCCESS)
111 return res;
112 }
113
114 ares_init_flags = flags;
115
116 return ARES_SUCCESS;
117 }
118
119
ares_library_cleanup(void)120 void ares_library_cleanup(void)
121 {
122 if (!ares_initialized)
123 return;
124 ares_initialized--;
125
126 if (ares_init_flags & ARES_LIB_INIT_WIN32)
127 ares_win32_cleanup();
128
129 ares_init_flags = ARES_LIB_INIT_NONE;
130 }
131
132
ares_library_initialized(void)133 int ares_library_initialized(void)
134 {
135 #ifdef USE_WINSOCK
136 if (!ares_initialized)
137 return ARES_ENOTINITIALIZED;
138 #endif
139 return ARES_SUCCESS;
140 }
141
142
143