mcs/class/System/System.Net/EndpointPermission.cs

   1 //
   2 // System.Net.EndpointPermission.cs
   3 //
   4 // Author:
   5 //   Lawrence Pit (loz@cable.a2000.nl)
   6 //
   7
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Collections;
  31 using System.Security;
  32 using System.Security.Permissions;
  33
  34 namespace System.Net
  35 {
  36         [Serializable]
  37         public class EndpointPermission // too bad about the lowercase p, not consistent with IPEndPoint ;)
  38         {
  39                 private static char [] dot_char = new char [] { '.' };
  40
  41                 // Fields
  42                 private string hostname;
  43                 private int port;
  44                 private TransportType transport;
  45
  46                 private bool resolved;
  47                 private bool hasWildcard;
  48                 private IPAddress [] addresses;
  49
  50                 // Constructors
  51                 internal EndpointPermission (string hostname,
  52                                              int port,
  53                                              TransportType transport) : base ()
  54                 {
  55                         if (hostname == null)
  56                                 throw new ArgumentNullException ("hostname");
  57                         this.hostname = hostname;
  58                         this.port = port;
  59                         this.transport = transport;
  60                         this.resolved = false;
  61                         this.hasWildcard = false;
  62                         this.addresses = null;
  63                 }
  64
  65                 // Properties
  66
  67                 public string Hostname {
  68                         get { return hostname; }
  69                 }
  70
  71                 public int Port {
  72                         get { return port; }
  73                 }
  74
  75                 public TransportType Transport {
  76                         get { return transport; }
  77                 }
  78
  79                 // Methods
  80
  81                 public override bool Equals (object obj)
  82                 {
  83                         EndpointPermission epp = obj as EndpointPermission;
  84                         return ((epp != null) &&
  85                                 (this.port == epp.port) &&
  86                                 (this.transport == epp.transport) &&
  87                                 (String.Compare (this.hostname, epp.hostname, true) == 0));
  88                 }
  89
  90                 public override int GetHashCode ()
  91                 {
  92                         return ToString ().GetHashCode ();
  93                 }
  94
  95                 public override string ToString ()
  96                 {
  97                         return hostname + "#" + port + "#" + (int) transport;
  98                 }
  99
 100                 // Internal & Private Methods
 101
 102                 internal bool IsSubsetOf (EndpointPermission perm)
 103                 {
 104                         if (perm == null)
 105                                 return false;
 106
 107                         if (perm.port != SocketPermission.AllPorts &&
 108                             this.port != perm.port)
 109                                 return false;
 110
 111                         if (perm.transport != TransportType.All &&
 112                             this.transport != perm.transport)
 113                                 return false;
 114
 115                         this.Resolve ();
 116                         perm.Resolve ();
 117
 118                         if (this.hasWildcard) {
 119                                 if (perm.hasWildcard)
 120                                         return IsSubsetOf (this.hostname, perm.hostname);
 121                                 else
 122                                         return false;
 123                         }
 124
 125                         if (this.addresses == null)
 126                                 return false;
 127
 128                         if (perm.hasWildcard)
 129                                 // a bit dubious... should they all be a subset or is one
 130                                 // enough in this case?
 131                                 foreach (IPAddress addr in this.addresses)
 132                                         if (IsSubsetOf (addr.ToString (), perm.hostname))
 133                                                 return true;
 134
 135                         if (perm.addresses == null)
 136                                 return false;
 137
 138                         // a bit dubious... should they all be a subset or is one
 139                         // enough in this case?
 140                         foreach (IPAddress addr in perm.addresses)
 141                                 if (IsSubsetOf (this.hostname, addr.ToString ()))
 142                                         return true;
 143
 144                         return false;
 145                 }
 146
 147                 private bool IsSubsetOf (string addr1, string addr2)
 148                 {
 149                         string [] h1 = addr1.Split (dot_char);
 150                         string [] h2 = addr2.Split (dot_char);
 151
 152                         for (int i = 0; i < 4; i++) {
 153                                 int part1 = ToNumber (h1 [i]);
 154                                 if (part1 == -1)
 155                                         return false;
 156
 157                                 int part2 = ToNumber (h2 [i]);
 158                                 if (part2 == -1)
 159                                         return false;
 160                                 if (part1 != part2 && part2 != 256)
 161                                         return false;
 162                         }
 163                         return true;
 164                 }
 165
 166                 internal EndpointPermission Intersect (EndpointPermission perm)
 167                 {
 168                         if (perm == null)
 169                                 return null;
 170
 171                         int _port;
 172                         if (this.port == perm.port)
 173                                 _port = this.port;
 174                         else if (this.port == SocketPermission.AllPorts)
 175                                 _port = perm.port;
 176                         else if (perm.port == SocketPermission.AllPorts)
 177                                 _port = this.port;
 178                         else
 179                                 return null;
 180
 181                         TransportType _transport;
 182                         if (this.transport == perm.transport)
 183                                 _transport = this.transport;
 184                         else if (this.transport == TransportType.All)
 185                                 _transport = perm.transport;
 186                         else if (perm.transport == TransportType.All)
 187                                 _transport = this.transport;
 188                         else
 189                                 return null;
 190
 191                         string _hostname = IntersectHostname (perm);
 192
 193                         if (_hostname == null)
 194                                 return null;
 195
 196                         if (!this.hasWildcard)
 197                                 return this;
 198
 199                         if (!perm.hasWildcard)
 200                                 return perm;
 201
 202                         EndpointPermission newperm = new EndpointPermission (_hostname, _port, _transport);
 203                         newperm.hasWildcard = true;
 204                         newperm.resolved = true;
 205                         return newperm;
 206                 }
 207
 208                 private string IntersectHostname (EndpointPermission perm)
 209                 {
 210                         if (this.hostname == perm.hostname)
 211                                 return this.hostname;
 212
 213                         this.Resolve ();
 214                         perm.Resolve ();
 215
 216                         string _hostname = null;
 217
 218                         if (this.hasWildcard) {
 219                                 if (perm.hasWildcard) {
 220                                         _hostname = Intersect (this.hostname, perm.hostname);
 221                                 } else if (perm.addresses != null) {
 222                                         for (int j = 0; j < perm.addresses.Length; j++) {
 223                                                 _hostname = Intersect (this.hostname, perm.addresses [j].ToString ());
 224                                                 if (_hostname != null)
 225                                                         break;
 226                                         }
 227                                 }
 228                         } else if (this.addresses != null) {
 229                                 for (int i = 0; i < this.addresses.Length; i++) {
 230                                         string thisaddr = this.addresses [i].ToString ();
 231                                         if (perm.hasWildcard) {
 232                                                 _hostname = Intersect (thisaddr, perm.hostname);
 233                                         } else if (perm.addresses != null) {
 234                                                 for (int j = 0; j < perm.addresses.Length; j++) {
 235                                                         _hostname = Intersect (thisaddr, perm.addresses [j].ToString ());
 236                                                         if (_hostname != null)
 237                                                                 break;
 238                                                 }
 239                                         }
 240                                 }
 241                         }
 242
 243                         return _hostname;
 244                 }
 245
 246                 // alas, currently we'll only support IPv4 as that's MS.Net behaviour
 247                 // returns null when both host strings do not intersect
 248                 private string Intersect (string addr1, string addr2)
 249                 {
 250                         string [] h1 = addr1.Split (dot_char);
 251                         string [] h2 = addr2.Split (dot_char);
 252
 253                         string [] s = new string [7];
 254                         for (int i = 0; i < 4; i++) {
 255                                 int part1 = ToNumber (h1 [i]);
 256                                 if (part1 == -1)
 257                                         return null;
 258
 259                                 int part2 = ToNumber (h2 [i]);
 260                                 if (part2 == -1)
 261                                         return null;
 262
 263                                 if (part1 == 256)
 264                                         s [i << 1] = (part2 == 256) ? "*" : String.Empty + part2;
 265                                 else if (part2 == 256)
 266                                         s [i << 1] = (part1 == 256) ? "*" : String.Empty + part1;
 267                                 else if (part1 == part2)
 268                                         s [i << 1] = String.Empty + part1;
 269                                 else
 270                                         return null;
 271                         }
 272
 273                         s [1] = s [3] = s [5] = ".";
 274                         return String.Concat (s);
 275                 }
 276
 277                 // returns 256 if value is a '*' character
 278                 // returns -1 if value isn't a number between 0 and 255
 279                 private int ToNumber (string value)
 280                 {
 281                         if (value == "*")
 282                                 return 256;
 283
 284                         int len = value.Length;
 285                         if (len < 1 || len > 3)
 286                                 return -1;
 287
 288                         int val = 0;
 289                         for (int i = 0; i < len; i++) {
 290                                 char c = value [i];
 291                                 if ('0' <= c && c <= '9')
 292                                         val = checked (val * 10 + (c - '0'));
 293                                 else
 294                                         return -1;
 295                         }
 296
 297                         return val <= 255 ? val : -1;
 298                 }
 299
 300                 internal void Resolve ()
 301                 {
 302                         if (resolved)
 303                                 return;
 304
 305                         bool isHostname = false;
 306                         bool hasWildcard = false;
 307                         this.addresses = null;
 308
 309                         string [] s = hostname.Split (dot_char);
 310
 311                         if (s.Length != 4) {
 312                                 isHostname = true;
 313                         } else {
 314                                 for (int i = 0; i < 4; i++) {
 315                                         int quad = ToNumber (s [i]);
 316                                         if (quad == -1) {
 317                                                 isHostname = true;
 318                                                 break;
 319                                         }
 320                                         if (quad == 256)
 321                                                 hasWildcard = true;
 322                                 }
 323                         }
 324
 325                         if (isHostname) {
 326                                 this.hasWildcard = false;
 327                                 try {
 328                                         this.addresses = Dns.GetHostByName (hostname).AddressList;
 329                                 } catch (System.Net.Sockets.SocketException) {
 330                                 }
 331                         } else {
 332                                 this.hasWildcard = hasWildcard;
 333                                 if (!hasWildcard) {
 334                                         addresses = new IPAddress [1];
 335                                         addresses [0] = IPAddress.Parse (hostname);
 336                                 }
 337                         }
 338
 339                         this.resolved = true;
 340                 }
 341
 342                 internal void UndoResolve ()
 343                 {
 344                         resolved = false;
 345                 }
 346         }
 347 }