curl/ares/ares_library_init.c
Yang Tse f96204dbe0 Remove run-time requirement for advapi32.dll since
c-ares can work even with no advapi32.dll at all.
2009-05-18 15:49:32 +00:00

107 lines
2.0 KiB
C

/* $Id$ */
#include "setup.h"
#include "ares.h"
#include "ares_library_init.h"
#include "ares_private.h"
/* library-private global and unique instance vars */
#ifdef WIN32
fpGetNetworkParams_t fpGetNetworkParams = ZERO_NULL;
fpSystemFunction036_t fpSystemFunction036 = ZERO_NULL;
#endif
/* library-private global vars with source visibility restricted to this file */
static unsigned int ares_initialized;
static int ares_init_flags;
#ifdef WIN32
static HMODULE hnd_iphlpapi;
static HMODULE hnd_advapi32;
#endif
static int ares_win32_init(void)
{
#ifdef WIN32
hnd_iphlpapi = 0;
hnd_iphlpapi = LoadLibrary("iphlpapi.dll");
if (!hnd_iphlpapi)
return ARES_ELOADIPHLPAPI;
fpGetNetworkParams = (fpGetNetworkParams_t)
GetProcAddress(hnd_iphlpapi, "GetNetworkParams");
if (!fpGetNetworkParams)
{
FreeLibrary(hnd_iphlpapi);
return ARES_EADDRGetNetworkParams;
}
/*
* When advapi32.dll is unavailable or advapi32.dll has no SystemFunction036,
* also known as RtlGenRandom, which is the case for Windows versions prior
* to WinXP then c-ares uses portable rand() function. Then don't error here.
*/
hnd_advapi32 = 0;
hnd_advapi32 = LoadLibrary("advapi32.dll");
if (hnd_advapi32)
{
fpSystemFunction036 = (fpSystemFunction036_t)
GetProcAddress(hnd_advapi32, "SystemFunction036");
}
#endif
return ARES_SUCCESS;
}
static void ares_win32_cleanup(void)
{
#ifdef WIN32
if (hnd_advapi32)
FreeLibrary(hnd_advapi32);
if (hnd_iphlpapi)
FreeLibrary(hnd_iphlpapi);
#endif
}
int ares_library_init(int flags)
{
int res;
if (ares_initialized)
return ARES_SUCCESS;
ares_initialized++;
if (flags & ARES_LIB_INIT_WIN32)
{
res = ares_win32_init();
if (res != ARES_SUCCESS)
return res;
}
ares_init_flags = flags;
return ARES_SUCCESS;
}
void ares_library_cleanup(void)
{
if (!ares_initialized)
return;
ares_initialized--;
if (ares_init_flags & ARES_LIB_INIT_WIN32)
ares_win32_cleanup();
ares_init_flags = ARES_LIB_INIT_NONE;
}