mcs/class/System/System.Net/IPv6Address.cs

   1 //\r
   2 // System.Net.IPv6AddressFormatter.cs\r
   3 //\r
   4 // Author:\r
   5 //   Lawrence Pit (loz@cable.a2000.nl)\r
   6 //\r
   7 // Permission is hereby granted, free of charge, to any person obtaining\r
   8 // a copy of this software and associated documentation files (the\r
   9 // "Software"), to deal in the Software without restriction, including\r
  10 // without limitation the rights to use, copy, modify, merge, publish,\r
  11 // distribute, sublicense, and/or sell copies of the Software, and to\r
  12 // permit persons to whom the Software is furnished to do so, subject to\r
  13 // the following conditions:\r
  14 // \r
  15 // The above copyright notice and this permission notice shall be\r
  16 // included in all copies or substantial portions of the Software.\r
  17 // \r
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
  19 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
  20 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
  21 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
  22 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
  23 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
  24 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  25 //\r
  26 \r
  27 using System.Globalization;\r
  28 using System.Text;\r
  29 \r
  30 namespace System.Net {\r
  31 \r
  32         struct IPv6AddressFormatter\r
  33         {\r
  34                 ushort [] address;\r
  35                 long scopeId;\r
  36 \r
  37                 public IPv6AddressFormatter (ushort[] addr, long scopeId)\r
  38                 {\r
  39                         this.address = addr;\r
  40                         this.scopeId = scopeId;\r
  41                 }\r
  42 \r
  43                 static ushort SwapUShort (ushort number)\r
  44                 {\r
  45                         return (ushort) ( ((number >> 8) & 0xFF) + ((number << 8) & 0xFF00) );\r
  46                 }\r
  47 \r
  48                 // Convert the address into a format expected by the IPAddress (long) ctor\r
  49                 // This needs to be unsigned to satisfy the '> 1' test in IsIPv4Compatible()\r
  50                 uint AsIPv4Int ()\r
  51                 {\r
  52                         return (uint)(SwapUShort (address [7]) << 16) + SwapUShort (address [6]);\r
  53                 }                       \r
  54 \r
  55                 bool IsIPv4Compatible ()\r
  56                 {\r
  57                         for (int i = 0; i < 6; i++) \r
  58                                 if (address [i] != 0)\r
  59                                         return false;\r
  60                         /* MS .net only seems to format the last 4\r
  61                          * bytes as an IPv4 address if address[6] is\r
  62                          * non-zero\r
  63                          */\r
  64                         if (address[6] == 0)\r
  65                                 return false;\r
  66                         return (AsIPv4Int () > 1);\r
  67                 }\r
  68                 \r
  69                 bool IsIPv4Mapped ()\r
  70                 {\r
  71                         for (int i = 0; i < 5; i++) \r
  72                                 if (address [i] != 0)\r
  73                                         return false;\r
  74                         /* MS .net only seems to format the last 4\r
  75                          * bytes as an IPv4 address if address[6] is\r
  76                          * non-zero\r
  77                          */\r
  78                         if (address[6] == 0)\r
  79                                 return false;\r
  80                         \r
  81                         return address [5] == 0xffff;\r
  82                 }\r
  83                 \r
  84                 public override string ToString ()\r
  85                 {\r
  86                         StringBuilder s = new StringBuilder ();\r
  87 \r
  88 \r
  89                         if(IsIPv4Compatible() || IsIPv4Mapped())\r
  90                         {\r
  91                                 s.Append("::");\r
  92 \r
  93                                 if(IsIPv4Mapped())\r
  94                                         s.Append("ffff:");\r
  95 \r
  96                                 s.Append(new IPAddress( AsIPv4Int ()).ToString ());\r
  97 \r
  98                                 return s.ToString ();\r
  99                         }\r
 100                         \r
 101                         int bestChStart = -1; // Best chain start\r
 102                         int bestChLen = 0; // Best chain length\r
 103                         int currChLen = 0; // Current chain length\r
 104 \r
 105                         // Looks for the longest zero chain\r
 106                         for (int i=0; i<8; i++)\r
 107                         {\r
 108                                 if (address[i] != 0)\r
 109                                 {\r
 110                                         if ((currChLen > bestChLen) \r
 111                                                 && (currChLen > 1))\r
 112                                         {\r
 113                                                 bestChLen = currChLen;\r
 114                                                 bestChStart = i - currChLen;\r
 115                                         }\r
 116                                         currChLen = 0;\r
 117                                 }\r
 118                                 else\r
 119                                         currChLen++;\r
 120                         }\r
 121                         if ((currChLen > bestChLen) \r
 122                                 && (currChLen > 1))\r
 123                         {\r
 124                                 bestChLen = currChLen;\r
 125                                 bestChStart = 8 - currChLen;\r
 126                         }\r
 127 \r
 128                         // makes the string\r
 129                         if (bestChStart == 0)\r
 130                                 s.Append(":");\r
 131                         for (int i=0; i<8; i++)\r
 132                         {\r
 133                                 if (i == bestChStart)\r
 134                                 {\r
 135                                         s.Append (":");\r
 136                                         i += (bestChLen - 1);\r
 137                                         continue;\r
 138                                 }\r
 139                                 s.AppendFormat("{0:x}", address [i]);\r
 140                                 if (i < 7) s.Append (':');\r
 141                         }\r
 142                         \r
 143                         if (scopeId != 0)\r
 144                                 s.Append ('%').Append (scopeId);\r
 145                         return s.ToString ();\r
 146                 }\r
 147         }\r
 148 }\r