/* Copyright 1998 by the Massachusetts Institute of Technology.

 * Copyright (C) 2004-2009 by Daniel Stenberg

 *

 * Permission to use, copy, modify, and distribute this

 * software and its documentation for any purpose and without

 * fee is hereby granted, provided that the above copyright

 * notice appear in all copies and that both that copyright

 * notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in

 * advertising or publicity pertaining to distribution of the

 * software without specific, written prior permission.

 * M.I.T. makes no representations about the suitability of

 * this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include "ares_setup.h"

#include "ares.h"

#include "ares_library_init.h"

#include "ares_private.h"

/* library-private global and unique instance vars */

#ifdef USE_WINSOCK

fpGetNetworkParams_t ares_fpGetNetworkParams = ZERO_NULL;

fpSystemFunction036_t ares_fpSystemFunction036 = ZERO_NULL;

fpGetAdaptersAddresses_t ares_fpGetAdaptersAddresses = ZERO_NULL;

fpGetBestRoute2_t ares_fpGetBestRoute2 = ZERO_NULL;

#endif

/* library-private global vars with source visibility restricted to this file */

static unsigned int ares_initialized;

static int          ares_init_flags;

/* library-private global vars with visibility across the whole library */

void *(*ares_malloc)(size_t size) = malloc;

void *(*ares_realloc)(void *ptr, size_t size) = realloc;

void (*ares_free)(void *ptr) = free;

#ifdef USE_WINSOCK

static HMODULE hnd_iphlpapi;

static HMODULE hnd_advapi32;

#endif

static int ares_win32_init(void)

{

#ifdef USE_WINSOCK

  hnd_iphlpapi = 0;

  hnd_iphlpapi = LoadLibraryW(L"iphlpapi.dll");

  if (!hnd_iphlpapi)

    return ARES_ELOADIPHLPAPI;

  ares_fpGetNetworkParams = (fpGetNetworkParams_t)

    GetProcAddress(hnd_iphlpapi, "GetNetworkParams");

  if (!ares_fpGetNetworkParams)

    {

      FreeLibrary(hnd_iphlpapi);

      return ARES_EADDRGETNETWORKPARAMS;

    }

  ares_fpGetAdaptersAddresses = (fpGetAdaptersAddresses_t)

    GetProcAddress(hnd_iphlpapi, "GetAdaptersAddresses");

  if (!ares_fpGetAdaptersAddresses)

    {

      /* This can happen on clients before WinXP, I don't

         think it should be an error, unless we don't want to

         support Windows 2000 anymore */

    }

  ares_fpGetBestRoute2 = (fpGetBestRoute2_t)

    GetProcAddress(hnd_iphlpapi, "GetBestRoute2");

  if (!ares_fpGetBestRoute2)

    {

      /* This can happen on clients before Vista, I don't

         think it should be an error, unless we don't want to

         support Windows XP anymore */

    }

  /*

   * 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 = LoadLibraryW(L"advapi32.dll");

  if (hnd_advapi32)

    {

      ares_fpSystemFunction036 = (fpSystemFunction036_t)

        GetProcAddress(hnd_advapi32, "SystemFunction036");

    }

#endif

  return ARES_SUCCESS;

}

static void ares_win32_cleanup(void)

{

#ifdef USE_WINSOCK

  if (hnd_advapi32)

    FreeLibrary(hnd_advapi32);

  if (hnd_iphlpapi)

    FreeLibrary(hnd_iphlpapi);

#endif

}

int ares_library_init(int flags)

{

  int res;

  if (ares_initialized)

    {

      ares_initialized++;

      return ARES_SUCCESS;

    }

  ares_initialized++;

  if (flags & ARES_LIB_INIT_WIN32)

    {

      res = ares_win32_init();

      if (res != ARES_SUCCESS)

        return res;  /* LCOV_EXCL_LINE: can't test Win32 init failure */

    }

  ares_init_flags = flags;

  return ARES_SUCCESS;

}

int ares_library_init_mem(int flags,

                          void *(*amalloc)(size_t size),

                          void (*afree)(void *ptr),

                          void *(*arealloc)(void *ptr, size_t size))

{

  if (amalloc)

    ares_malloc = amalloc;

  if (arealloc)

    ares_realloc = arealloc;

  if (afree)

    ares_free = afree;

  return ares_library_init(flags);

}

void ares_library_cleanup(void)

{

  if (!ares_initialized)

    return;

  ares_initialized--;

  if (ares_initialized)

    return;

  if (ares_init_flags & ARES_LIB_INIT_WIN32)

    ares_win32_cleanup();

  ares_init_flags = ARES_LIB_INIT_NONE;

  ares_malloc = malloc;

  ares_realloc = realloc;

  ares_free = free;

}

int ares_library_initialized(void)

{

#ifdef USE_WINSOCK

  if (!ares_initialized)

    return ARES_ENOTINITIALIZED;

#endif

  return ARES_SUCCESS;

}