Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk


git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/base/nethelpers.cc b/talk/base/nethelpers.cc
new file mode 100644
index 0000000..eebc6cf
--- /dev/null
+++ b/talk/base/nethelpers.cc
@@ -0,0 +1,142 @@
+/*
+ * 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_array<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