/// <summary>
/// Parses the <see cref="NetworkProtocol"/>.
/// </summary>
/// <param name="text">Unparsed text.</param>
/// <returns>The parsed <see cref="NetworkProtocol"/>.</returns>
private static NetworkProtocol ParseNetworkProtocol(string text)
{
string trimmed = text.Trim();
if ("Any" == trimmed)
{
return(new NetworkProtocol
{
Any = true
});
}
int protocolNumber;
if (!NetworkProtocol.TryGetProtocolNumber(trimmed, out protocolNumber))
{
protocolNumber = int.Parse(trimmed);
}
return(new NetworkProtocol
{
Any = false,
ProtocolNumber = protocolNumber
});
}
/// <summary>
/// Creates a boolean expression expressing the conditions under which the given packet
/// variables match this specific packet.
/// </summary>
/// <param name="ctx">The Z3 context.</param>
/// <param name="packet">The packet variables over which to form an expression.</param>
/// <returns>A boolean expression.</returns>
public BoolExpr Matches(Context ctx, WindowsFirewallPacketVariables packet)
{
var conjuncts = new List <BoolExpr>();
if (this.SourceAddress != null)
{
conjuncts.Add(ctx.MkEq(packet.SourceAddress, AddressRange.AddressToBitVecExpr(ctx, this.SourceAddress)));
}
if (this.SourcePort != null)
{
conjuncts.Add(ctx.MkEq(packet.SourcePort, PortRange.PortToBitVecExpr(ctx, (int)this.SourcePort)));
}
if (this.DestinationPort != null)
{
conjuncts.Add(ctx.MkEq(packet.DestinationPort, PortRange.PortToBitVecExpr(ctx, (int)this.DestinationPort)));
}
if (this.Protocol != null)
{
conjuncts.Add(ctx.MkEq(packet.Protocol, NetworkProtocol.ProtocolToBitVecExpr(ctx, (int)this.Protocol)));
}
return(ctx.MkAnd(conjuncts.ToArray()));
}
/// <summary>
/// Builds a boolean expression over the port variable which is true only if
/// the protocol variable value, once bound, matches this protocol.
/// </summary>
/// <param name="ctx">The Z3 context.</param>
/// <param name="protocol">The protocol variable to check for match.</param>
/// <returns>A Z3 boolean expression.</returns>
public BoolExpr Matches(Context ctx, BitVecExpr protocol)
{
if (this.Any)
{
return(ctx.MkTrue());
}
return(ctx.MkEq(protocol, NetworkProtocol.ProtocolToBitVecExpr(ctx, this.ProtocolNumber)));
}
