public static GetHostByName ( string hostName ) : |
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hostName | string | |
return |
private static IPHostEntry InternalGetHostByName(string hostName, bool includeIPv6) { if (NetEventSource.Log.IsEnabled()) { NetEventSource.Enter(NetEventSource.ComponentType.Socket, "DNS", "GetHostByName", hostName); } IPHostEntry ipHostEntry = null; if (GlobalLog.IsEnabled) { GlobalLog.Print("Dns.GetHostByName: " + hostName); } if (hostName.Length > MaxHostName || // If 255 chars, the last one must be a dot. hostName.Length == MaxHostName && hostName[MaxHostName - 1] != '.') { throw new ArgumentOutOfRangeException(nameof(hostName), SR.Format(SR.net_toolong, nameof(hostName), MaxHostName.ToString(NumberFormatInfo.CurrentInfo))); } // // IPv6 Changes: IPv6 requires the use of getaddrinfo() rather // than the traditional IPv4 gethostbyaddr() / gethostbyname(). // getaddrinfo() is also protocol independent in that it will also // resolve IPv4 names / addresses. As a result, it is the preferred // resolution mechanism on platforms that support it (Windows 5.1+). // If getaddrinfo() is unsupported, IPv6 resolution does not work. // // Consider : If IPv6 is disabled, we could detect IPv6 addresses // and throw an unsupported platform exception. // // Note : Whilst getaddrinfo is available on WinXP+, we only // use it if IPv6 is enabled (platform is part of that // decision). This is done to minimize the number of // possible tests that are needed. // if (includeIPv6 || SocketProtocolSupportPal.OSSupportsIPv6) { // // IPv6 enabled: use getaddrinfo() to obtain DNS information. // int nativeErrorCode; SocketError errorCode = NameResolutionPal.TryGetAddrInfo(hostName, out ipHostEntry, out nativeErrorCode); if (errorCode != SocketError.Success) { throw SocketExceptionFactory.CreateSocketException(errorCode, nativeErrorCode); } } else { ipHostEntry = NameResolutionPal.GetHostByName(hostName); } if (NetEventSource.Log.IsEnabled()) { NetEventSource.Exit(NetEventSource.ComponentType.Socket, "DNS", "GetHostByName", ipHostEntry); } return(ipHostEntry); } // GetHostByName
private static IPHostEntry InternalGetHostByName(string hostName, bool includeIPv6) { if (NetEventSource.IsEnabled) { NetEventSource.Enter(null, hostName); } IPHostEntry ipHostEntry = null; ValidateHostName(hostName); // // IPv6 Changes: IPv6 requires the use of getaddrinfo() rather // than the traditional IPv4 gethostbyaddr() / gethostbyname(). // getaddrinfo() is also protocol independent in that it will also // resolve IPv4 names / addresses. As a result, it is the preferred // resolution mechanism on platforms that support it (Windows 5.1+). // If getaddrinfo() is unsupported, IPv6 resolution does not work. // // Consider : If IPv6 is disabled, we could detect IPv6 addresses // and throw an unsupported platform exception. // // Note : Whilst getaddrinfo is available on WinXP+, we only // use it if IPv6 is enabled (platform is part of that // decision). This is done to minimize the number of // possible tests that are needed. // if (includeIPv6 || SocketProtocolSupportPal.OSSupportsIPv6) { // // IPv6 enabled: use getaddrinfo() to obtain DNS information. // int nativeErrorCode; SocketError errorCode = NameResolutionPal.TryGetAddrInfo(hostName, out ipHostEntry, out nativeErrorCode); if (errorCode != SocketError.Success) { throw SocketExceptionFactory.CreateSocketException(errorCode, nativeErrorCode); } } else { ipHostEntry = NameResolutionPal.GetHostByName(hostName); } if (NetEventSource.IsEnabled) { NetEventSource.Exit(null, ipHostEntry); } return(ipHostEntry); } // GetHostByName