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 fpGetBestRoute2_t ares_fpGetBestRoute2 = ZERO_NULL;
31 #endif
32
33 #if defined(ANDROID) || defined(__ANDROID__)
34 #include "ares_android.h"
35 #endif
36
37 /* library-private global vars with source visibility restricted to this file */
38
39 static unsigned int ares_initialized;
40 static int ares_init_flags;
41
42 /* library-private global vars with visibility across the whole library */
43 #if defined(WIN32)
44 /* We need indirections to handle Windows DLL rules. */
default_malloc(size_t size)45 static void *default_malloc(size_t size) { return malloc(size); }
default_realloc(void * p,size_t size)46 static void *default_realloc(void *p, size_t size) { return realloc(p, size); }
default_free(void * p)47 static void default_free(void *p) { free(p); }
48 #else
49 # define default_malloc malloc
50 # define default_realloc realloc
51 # define default_free free
52 #endif
53 void *(*ares_malloc)(size_t size) = default_malloc;
54 void *(*ares_realloc)(void *ptr, size_t size) = default_realloc;
55 void (*ares_free)(void *ptr) = default_free;
56
57 #ifdef USE_WINSOCK
58 static HMODULE hnd_iphlpapi;
59 static HMODULE hnd_advapi32;
60 #endif
61
62
ares_win32_init(void)63 static int ares_win32_init(void)
64 {
65 #ifdef USE_WINSOCK
66
67 hnd_iphlpapi = 0;
68 hnd_iphlpapi = LoadLibraryW(L"iphlpapi.dll");
69 if (!hnd_iphlpapi)
70 return ARES_ELOADIPHLPAPI;
71
72 ares_fpGetNetworkParams = (fpGetNetworkParams_t)
73 GetProcAddress(hnd_iphlpapi, "GetNetworkParams");
74 if (!ares_fpGetNetworkParams)
75 {
76 FreeLibrary(hnd_iphlpapi);
77 return ARES_EADDRGETNETWORKPARAMS;
78 }
79
80 ares_fpGetAdaptersAddresses = (fpGetAdaptersAddresses_t)
81 GetProcAddress(hnd_iphlpapi, "GetAdaptersAddresses");
82 if (!ares_fpGetAdaptersAddresses)
83 {
84 /* This can happen on clients before WinXP, I don't
85 think it should be an error, unless we don't want to
86 support Windows 2000 anymore */
87 }
88
89 ares_fpGetBestRoute2 = (fpGetBestRoute2_t)
90 GetProcAddress(hnd_iphlpapi, "GetBestRoute2");
91 if (!ares_fpGetBestRoute2)
92 {
93 /* This can happen on clients before Vista, I don't
94 think it should be an error, unless we don't want to
95 support Windows XP anymore */
96 }
97
98 /*
99 * When advapi32.dll is unavailable or advapi32.dll has no SystemFunction036,
100 * also known as RtlGenRandom, which is the case for Windows versions prior
101 * to WinXP then c-ares uses portable rand() function. Then don't error here.
102 */
103
104 hnd_advapi32 = 0;
105 hnd_advapi32 = LoadLibraryW(L"advapi32.dll");
106 if (hnd_advapi32)
107 {
108 ares_fpSystemFunction036 = (fpSystemFunction036_t)
109 GetProcAddress(hnd_advapi32, "SystemFunction036");
110 }
111
112 #endif
113 return ARES_SUCCESS;
114 }
115
116
ares_win32_cleanup(void)117 static void ares_win32_cleanup(void)
118 {
119 #ifdef USE_WINSOCK
120 if (hnd_advapi32)
121 FreeLibrary(hnd_advapi32);
122 if (hnd_iphlpapi)
123 FreeLibrary(hnd_iphlpapi);
124 #endif
125 }
126
127
ares_library_init(int flags)128 int ares_library_init(int flags)
129 {
130 int res;
131
132 if (ares_initialized)
133 {
134 ares_initialized++;
135 return ARES_SUCCESS;
136 }
137 ares_initialized++;
138
139 if (flags & ARES_LIB_INIT_WIN32)
140 {
141 res = ares_win32_init();
142 if (res != ARES_SUCCESS)
143 return res; /* LCOV_EXCL_LINE: can't test Win32 init failure */
144 }
145
146 ares_init_flags = flags;
147
148 return ARES_SUCCESS;
149 }
150
ares_library_init_mem(int flags,void * (* amalloc)(size_t size),void (* afree)(void * ptr),void * (* arealloc)(void * ptr,size_t size))151 int ares_library_init_mem(int flags,
152 void *(*amalloc)(size_t size),
153 void (*afree)(void *ptr),
154 void *(*arealloc)(void *ptr, size_t size))
155 {
156 if (amalloc)
157 ares_malloc = amalloc;
158 if (arealloc)
159 ares_realloc = arealloc;
160 if (afree)
161 ares_free = afree;
162 return ares_library_init(flags);
163 }
164
165
ares_library_cleanup(void)166 void ares_library_cleanup(void)
167 {
168 if (!ares_initialized)
169 return;
170 ares_initialized--;
171 if (ares_initialized)
172 return;
173
174 if (ares_init_flags & ARES_LIB_INIT_WIN32)
175 ares_win32_cleanup();
176
177 #if defined(ANDROID) || defined(__ANDROID__)
178 ares_library_cleanup_android();
179 #endif
180
181 ares_init_flags = ARES_LIB_INIT_NONE;
182 ares_malloc = malloc;
183 ares_realloc = realloc;
184 ares_free = free;
185 }
186
187
ares_library_initialized(void)188 int ares_library_initialized(void)
189 {
190 #ifdef USE_WINSOCK
191 if (!ares_initialized)
192 return ARES_ENOTINITIALIZED;
193 #endif
194 return ARES_SUCCESS;
195 }
196