static IDhcpOption ParseDhcpOption(
byte optionCode,
byte length,
byte[] srcBuffer,
int offset)
{
byte type = optionCode;
switch (optionCode)
{
case DhcpSubnetMask.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpTimeOffset.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpRouter.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpTimeServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpNameServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpDomainNameServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpLogServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpCookieServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpLprServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpImpressServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpResourceLocationServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpHostName.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpBootFileSize.OptionCode:
return(DhcpWordOption.Parse(type, length, srcBuffer, offset));
case DhcpMeritDumpFile.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpDomainName.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpSwapServer.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpRootPath.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpExtensionsPath.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpIPForwarding.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpForwardRemoteSourceRoute.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpPolicyFilter.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpMaximumDatagramReassembly.OptionCode:
return(DhcpWordOption.Parse(type, length, srcBuffer, offset));
case DhcpDefaultTtl.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpPathMtuAgingTimeout.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpPathMtuPlateauTable.OptionCode:
return(DhcpMultiWordOption.Parse(type, length, srcBuffer, offset));
case DhcpInterfaceMtu.OptionCode:
return(DhcpWordOption.Parse(type, length, srcBuffer, offset));
case DhcpAllSubnetsLocal.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpBroadcastAddress.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpMaskDiscovery.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpMaskSupplier.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpRouterDiscovery.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpRouterSolicitationAddress.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpStaticRoutes.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpTrailerEncapsulate.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpArpCacheTimeout.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpEthernetEncapsulation.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpTcpDefaultTtl.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpTcpKeepalive.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpTcpKeepaliveGarbage.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpNisDomain.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpNisServers.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpNtpServers.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpVendorSpecific.OptionCode:
return(DhcpMultiByteOption.Parse(type, length, srcBuffer, offset));
case DhcpNetBiosNameServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpNetBiosDistributionServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpNetBiosType.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpNetBiosScope.OptionCode:
return(DhcpMultiDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpXWindowsFontServer.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpXWindowsDisplayManager.OptionCode:
return(DhcpMultiIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpRequestedIPAddress.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpIPAddressLeaseTime.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpOverloadIndicator.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpMessageType.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
case DhcpServerID.OptionCode:
return(DhcpIPv4Option.Parse(type, length, srcBuffer, offset));
case DhcpParameterRequest.OptionCode:
return(DhcpMultiByteOption.Parse(type, length, srcBuffer, offset));
case DhcpMessage.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpMaximumMessageSize.OptionCode:
return(DhcpWordOption.Parse(type, length, srcBuffer, offset));
case DhcpRenewalTime.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpRebindingTime.OptionCode:
return(DhcpDWordOption.Parse(type, length, srcBuffer, offset));
case DhcpClassID.OptionCode:
return(DhcpStringOption.Parse(type, length, srcBuffer, offset));
case DhcpClientID.OptionCode:
return(DhcpMultiByteOption.Parse(type, length, srcBuffer, offset));
case DhcpAutoConfigure.OptionCode:
return(DhcpByteOption.Parse(type, length, srcBuffer, offset));
default: return(null);
}
}
public static SortedList Parse(byte[] data, int offset, int length)
{
const byte PadByte = 0;
const byte EndByte = 255;
SortedList dhcpOptions = new SortedList();
while (offset != length)
{
// skip padding
while (data[offset] == PadByte)
{
offset++;
if (offset == length)
{
goto finished_options;
}
}
if (data[offset] == EndByte)
{
break;
}
byte @opt = data[offset++];
byte optlen = data[offset++];
if (optlen == 0)
{
// Unknown, ignore
continue;
}
if (optlen + offset > length)
{
break;
}
// Remove any outstanding option with the same option number
// before adding option to list of those already parsed to
// prevent SortedList::Add from throwing ArgumentException
dhcpOptions.Remove(opt);
try {
object name = ParserName(opt);
if (name != null)
{
dhcpOptions.Add(
opt, ParseDhcpOption(@opt, optlen, data, offset)
);
}
else
{
// For unknowns fall back to multi-byte parser
dhcpOptions.Add(
@opt, DhcpMultiByteOption.Parse(@opt, optlen,
data, offset)
);
}
}
catch (InvalidDhcpOptionLength) {
}
offset += optlen;
}
finished_options:
return(dhcpOptions);
}