| #region Apache License |
| // |
| // Licensed to the Apache Software Foundation (ASF) under one or more |
| // contributor license agreements. See the NOTICE file distributed with |
| // this work for additional information regarding copyright ownership. |
| // The ASF licenses this file to you under the Apache License, Version 2.0 |
| // (the "License"); you may not use this file except in compliance with |
| // the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| #endregion |
| |
| using System; |
| using System.Net; |
| |
| namespace log4net.Util.TypeConverters |
| { |
| /// <summary> |
| /// Supports conversion from string to <see cref="IPAddress"/> type. |
| /// </summary> |
| /// <remarks> |
| /// <para> |
| /// Supports conversion from string to <see cref="IPAddress"/> type. |
| /// </para> |
| /// </remarks> |
| /// <seealso cref="ConverterRegistry"/> |
| /// <seealso cref="IConvertFrom"/> |
| /// <author>Nicko Cadell</author> |
| internal class IPAddressConverter : IConvertFrom |
| { |
| #region Implementation of IConvertFrom |
| |
| /// <summary> |
| /// Can the source type be converted to the type supported by this object |
| /// </summary> |
| /// <param name="sourceType">the type to convert</param> |
| /// <returns>true if the conversion is possible</returns> |
| /// <remarks> |
| /// <para> |
| /// Returns <c>true</c> if the <paramref name="sourceType"/> is |
| /// the <see cref="String"/> type. |
| /// </para> |
| /// </remarks> |
| public bool CanConvertFrom(Type sourceType) |
| { |
| return (sourceType == typeof(string)); |
| } |
| |
| /// <summary> |
| /// Overrides the ConvertFrom method of IConvertFrom. |
| /// </summary> |
| /// <param name="source">the object to convert to an IPAddress</param> |
| /// <returns>the IPAddress</returns> |
| /// <remarks> |
| /// <para> |
| /// Uses the <see cref="IPAddress.Parse"/> method to convert the |
| /// <see cref="String"/> argument to an <see cref="IPAddress"/>. |
| /// If that fails then the string is resolved as a DNS hostname. |
| /// </para> |
| /// </remarks> |
| /// <exception cref="ConversionNotSupportedException"> |
| /// The <paramref name="source"/> object cannot be converted to the |
| /// target type. To check for this condition use the <see cref="CanConvertFrom"/> |
| /// method. |
| /// </exception> |
| public object ConvertFrom(object source) |
| { |
| string str = source as string; |
| if (str != null && str.Length > 0) |
| { |
| try |
| { |
| #if NET_2_0 || NETCF_2_0 |
| |
| #if !NETCF_2_0 |
| // Try an explicit parse of string representation of an IPAddress (v4 or v6) |
| IPAddress result; |
| if (IPAddress.TryParse(str, out result)) |
| { |
| return result; |
| } |
| #endif |
| |
| // Try to resolve via DNS. This is a blocking call. |
| // GetHostEntry works with either an IPAddress string or a host name |
| IPHostEntry host = Dns.GetHostEntry(str); |
| if (host != null && |
| host.AddressList != null && |
| host.AddressList.Length > 0 && |
| host.AddressList[0] != null) |
| { |
| return host.AddressList[0]; |
| } |
| #else |
| // Before .NET 2 we need to try to parse the IPAddress from the string first |
| |
| // Check if the string only contains IP address valid chars |
| if (str.Trim(validIpAddressChars).Length == 0) |
| { |
| try |
| { |
| // try to parse the string as an IP address |
| return IPAddress.Parse(str); |
| } |
| catch(FormatException) |
| { |
| // Ignore a FormatException, try to resolve via DNS |
| } |
| } |
| |
| // Try to resolve via DNS. This is a blocking call. |
| #if NETSTANDARD1_3 |
| IPHostEntry host = Dns.GetHostEntryAsync(str).GetAwaiter().GetResult(); |
| #else |
| IPHostEntry host = Dns.GetHostByName(str); |
| #endif |
| if (host != null && |
| host.AddressList != null && |
| host.AddressList.Length > 0 && |
| host.AddressList[0] != null) |
| { |
| return host.AddressList[0]; |
| } |
| #endif |
| } |
| catch(Exception ex) |
| { |
| throw ConversionNotSupportedException.Create(typeof(IPAddress), source, ex); |
| } |
| } |
| throw ConversionNotSupportedException.Create(typeof(IPAddress), source); |
| } |
| |
| #endregion |
| |
| /// <summary> |
| /// Valid characters in an IPv4 or IPv6 address string. (Does not support subnets) |
| /// </summary> |
| private static readonly char[] validIpAddressChars = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','A','B','C','D','E','F','x','X','.',':','%'}; |
| } |
| } |