netwerk/base/IPv6Utils.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef NETWORK_IPV6_UTILS_H_
   6 #define NETWORK_IPV6_UTILS_H_
   7
   8 namespace mozilla {
   9 namespace net {
  10 namespace utils {
  11
  12 // IPv6 address scopes.
  13 #define IPV6_SCOPE_GLOBAL 0       // Global scope.
  14 #define IPV6_SCOPE_LINKLOCAL 1    // Link-local scope.
  15 #define IPV6_SCOPE_SITELOCAL 2    // Site-local scope (deprecated).
  16 #define IPV6_SCOPE_UNIQUELOCAL 3  // Unique local
  17 #define IPV6_SCOPE_NODELOCAL 4    // Loopback
  18
  19 // Return the scope of the given address.
  20 static int ipv6_scope(const unsigned char addr[16]) {
  21   const unsigned char* b = addr;
  22   unsigned short w = (unsigned short)((b[0] << 8) | b[1]);
  23
  24   if ((b[0] & 0xFE) == 0xFC) {
  25     return IPV6_SCOPE_UNIQUELOCAL;
  26   }
  27   switch (w & 0xFFC0) {
  28     case 0xFE80:
  29       return IPV6_SCOPE_LINKLOCAL;
  30     case 0xFEC0:
  31       return IPV6_SCOPE_SITELOCAL;
  32     case 0x0000:
  33       w = b[1] | b[2] | b[3] | b[4] | b[5] | b[6] | b[7] | b[8] | b[9] | b[10] |
  34           b[11] | b[12] | b[13] | b[14];
  35       if (w || b[15] != 0x01) {
  36         break;
  37       }
  38       return IPV6_SCOPE_NODELOCAL;
  39     default:
  40       break;
  41   }
  42
  43   return IPV6_SCOPE_GLOBAL;
  44 }
  45
  46 }  // namespace utils
  47 }  // namespace net
  48 }  // namespace mozilla
  49
  50 #endif  // NETWORK_IPV6_UTILS_H_