base/nethelpers.cc

/*
 * libjingle
 * Copyright 2008, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "talk/base/nethelpers.h"

#if defined(WIN32)
#include <ws2spi.h>
#include <ws2tcpip.h>
#include "talk/base/win32.h"
#endif

#include "talk/base/byteorder.h"
#include "talk/base/signalthread.h"

namespace talk_base {

int ResolveHostname(const std::string& hostname, int family,
                    std::vector<IPAddress>* addresses) {
  if (!addresses) {
    return -1;
  }
  addresses->clear();
  struct addrinfo* result = NULL;
  struct addrinfo hints = {0};
  // TODO(djw): For now this is IPv4 only so existing users remain unaffected.
  hints.ai_family = AF_INET;
  hints.ai_flags = AI_ADDRCONFIG;
  int ret = getaddrinfo(hostname.c_str(), NULL, &hints, &result);
  if (ret != 0) {
    return ret;
  }
  struct addrinfo* cursor = result;
  for (; cursor; cursor = cursor->ai_next) {
    if (family == AF_UNSPEC || cursor->ai_family == family) {
      IPAddress ip;
      if (IPFromAddrInfo(cursor, &ip)) {
        addresses->push_back(ip);
      }
    }
  }
  freeaddrinfo(result);
  return 0;
}

// AsyncResolver
AsyncResolver::AsyncResolver() : error_(0) {
}

void AsyncResolver::DoWork() {
  error_ = ResolveHostname(addr_.hostname().c_str(), addr_.family(),
                           &addresses_);
}

void AsyncResolver::OnWorkDone() {
  if (addresses_.size() > 0) {
    addr_.SetIP(addresses_[0]);
  }
}

const char* inet_ntop(int af, const void *src, char* dst, socklen_t size) {
#ifdef WIN32
  return win32_inet_ntop(af, src, dst, size);
#else
  return ::inet_ntop(af, src, dst, size);
#endif
}

int inet_pton(int af, const char* src, void *dst) {
#ifdef WIN32
  return win32_inet_pton(af, src, dst);
#else
  return ::inet_pton(af, src, dst);
#endif
}

bool HasIPv6Enabled() {
#ifndef WIN32
  // We only need to check this for Windows XP (so far).
  return true;
#else
  if (IsWindowsVistaOrLater()) {
    return true;
  }
  if (!IsWindowsXpOrLater()) {
    return false;
  }
  DWORD protbuff_size = 4096;
  scoped_ptr<char[]> protocols;
  LPWSAPROTOCOL_INFOW protocol_infos = NULL;
  int requested_protocols[2] = {AF_INET6, 0};

  int err = 0;
  int ret = 0;
  // Check for protocols in a do-while loop until we provide a buffer large
  // enough. (WSCEnumProtocols sets protbuff_size to its desired value).
  // It is extremely unlikely that this will loop more than once.
  do {
    protocols.reset(new char[protbuff_size]);
    protocol_infos = reinterpret_cast<LPWSAPROTOCOL_INFOW>(protocols.get());
    ret = WSCEnumProtocols(requested_protocols, protocol_infos,
                           &protbuff_size, &err);
  } while (ret == SOCKET_ERROR && err == WSAENOBUFS);

  if (ret == SOCKET_ERROR) {
    return false;
  }

  // Even if ret is positive, check specifically for IPv6.
  // Non-IPv6 enabled WinXP will still return a RAW protocol.
  for (int i = 0; i < ret; ++i) {
    if (protocol_infos[i].iAddressFamily == AF_INET6) {
      return true;
    }
  }
  return false;
#endif
}
}  // namespace talk_base