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 == 256)
 161                                         continue;
 162                                 if (part1 != part2 && part2 != 256)
 163                                         return false;
 164                         }
 165                         return true;
 166                 }
 167
 168                 internal EndpointPermission Intersect (EndpointPermission perm)
 169                 {
 170                         if (perm == null)
 171                                 return null;
 172
 173                         int _port;
 174                         if (this.port == perm.port)
 175                                 _port = this.port;
 176                         else if (this.port == SocketPermission.AllPorts)
 177                                 _port = perm.port;
 178                         else if (perm.port == SocketPermission.AllPorts)
 179                                 _port = this.port;
 180                         else
 181                                 return null;
 182
 183                         TransportType _transport;
 184                         if (this.transport == perm.transport)
 185                                 _transport = this.transport;
 186                         else if (this.transport == TransportType.All)
 187                                 _transport = perm.transport;
 188                         else if (perm.transport == TransportType.All)
 189                                 _transport = this.transport;
 190                         else
 191                                 return null;
 192
 193                         string _hostname = IntersectHostname (perm);
 194
 195                         if (_hostname == null)
 196                                 return null;
 197
 198                         if (!this.hasWildcard)
 199                                 return this;
 200
 201                         if (!perm.hasWildcard)
 202                                 return perm;
 203
 204                         EndpointPermission newperm = new EndpointPermission (_hostname, _port, _transport);
 205                         newperm.hasWildcard = true;
 206                         newperm.resolved = true;
 207                         return newperm;
 208                 }
 209
 210                 private string IntersectHostname (EndpointPermission perm)
 211                 {
 212                         if (this.hostname == perm.hostname)
 213                                 return this.hostname;
 214
 215                         this.Resolve ();
 216                         perm.Resolve ();
 217
 218                         string _hostname = null;
 219
 220                         if (this.hasWildcard) {
 221                                 if (perm.hasWildcard) {
 222                                         _hostname = Intersect (this.hostname, perm.hostname);
 223                                 } else if (perm.addresses != null) {
 224                                         for (int j = 0; j < perm.addresses.Length; j++) {
 225                                                 _hostname = Intersect (this.hostname, perm.addresses [j].ToString ());
 226                                                 if (_hostname != null)
 227                                                         break;
 228                                         }
 229                                 }
 230                         } else if (this.addresses != null) {
 231                                 for (int i = 0; i < this.addresses.Length; i++) {
 232                                         string thisaddr = this.addresses [i].ToString ();
 233                                         if (perm.hasWildcard) {
 234                                                 _hostname = Intersect (thisaddr, perm.hostname);
 235                                         } else if (perm.addresses != null) {
 236                                                 for (int j = 0; j < perm.addresses.Length; j++) {
 237                                                         _hostname = Intersect (thisaddr, perm.addresses [j].ToString ());
 238                                                         if (_hostname != null)
 239                                                                 break;
 240                                                 }
 241                                         }
 242                                 }
 243                         }
 244
 245                         return _hostname;
 246                 }
 247
 248                 // alas, currently we'll only support IPv4 as that's MS.Net behaviour
 249                 // returns null when both host strings do not intersect
 250                 private string Intersect (string addr1, string addr2)
 251                 {
 252                         string [] h1 = addr1.Split (dot_char);
 253                         string [] h2 = addr2.Split (dot_char);
 254
 255                         string [] s = new string [7];
 256                         for (int i = 0; i < 4; i++) {
 257                                 int part1 = ToNumber (h1 [i]);
 258                                 if (part1 == -1)
 259                                         return null;
 260
 261                                 int part2 = ToNumber (h2 [i]);
 262                                 if (part2 == -1)
 263                                         return null;
 264
 265                                 if (part1 == 256)
 266                                         s [i << 1] = (part2 == 256) ? "*" : String.Empty + part2;
 267                                 else if (part2 == 256)
 268                                         s [i << 1] = (part1 == 256) ? "*" : String.Empty + part1;
 269                                 else if (part1 == part2)
 270                                         s [i << 1] = String.Empty + part1;
 271                                 else
 272                                         return null;
 273                         }
 274
 275                         s [1] = s [3] = s [5] = ".";
 276                         return String.Concat (s);
 277                 }
 278
 279                 // returns 256 if value is a '*' character
 280                 // returns -1 if value isn't a number between 0 and 255
 281                 private int ToNumber (string value)
 282                 {
 283                         if (value == "*")
 284                                 return 256;
 285
 286                         int len = value.Length;
 287                         if (len < 1 || len > 3)
 288                                 return -1;
 289
 290                         int val = 0;
 291                         for (int i = 0; i < len; i++) {
 292                                 char c = value [i];
 293                                 if ('0' <= c && c <= '9')
 294                                         val = checked (val * 10 + (c - '0'));
 295                                 else
 296                                         return -1;
 297                         }
 298
 299                         return val <= 255 ? val : -1;
 300                 }
 301
 302                 internal void Resolve ()
 303                 {
 304                         if (resolved)
 305                                 return;
 306
 307                         bool isHostname = false;
 308                         bool hasWildcard = false;
 309                         this.addresses = null;
 310
 311                         string [] s = hostname.Split (dot_char);
 312
 313                         if (s.Length != 4) {
 314                                 isHostname = true;
 315                         } else {
 316                                 for (int i = 0; i < 4; i++) {
 317                                         int quad = ToNumber (s [i]);
 318                                         if (quad == -1) {
 319                                                 isHostname = true;
 320                                                 break;
 321                                         }
 322                                         if (quad == 256)
 323                                                 hasWildcard = true;
 324                                 }
 325                         }
 326
 327                         if (isHostname) {
 328                                 this.hasWildcard = false;
 329                                 try {
 330                                         this.addresses = Dns.GetHostAddresses (hostname);
 331                                 } catch (System.Net.Sockets.SocketException) {
 332                                 }
 333                         } else {
 334                                 this.hasWildcard = hasWildcard;
 335                                 if (!hasWildcard) {
 336                                         addresses = new IPAddress [1];
 337                                         addresses [0] = IPAddress.Parse (hostname);
 338                                 }
 339                         }
 340
 341                         this.resolved = true;
 342                 }
 343
 344                 internal void UndoResolve ()
 345                 {
 346                         resolved = false;
 347                 }
 348         }
 349 }