/// <summary>
/// Create a new ARP packet.
/// </summary>
/// <param name="data">
/// The data representing the ARP packet.
/// </param>
public ArpPacket(byte[] data)
{
int position = 0;
m_hardware = (MediaType)IPAddress.NetworkToHostOrder (BitConverter.ToInt16 (data, position));
position += 2;
m_protocol = (NetworkLayerProtocol)BitConverter.ToInt16 (data, position);
position += 2;
int macLength = data[position];
position ++;
int ipLength = data[position];
position++;
m_type = (ArpOpcode)IPAddress.NetworkToHostOrder (BitConverter.ToInt16 (data, position));
position += 2;
// copy out source MAC
byte[] sourceMac = new byte[macLength];
Array.Copy (data, position, sourceMac, 0, macLength);
m_sourceMac = new MACAddress (sourceMac);
position += macLength;
// copy out source IP
byte[] sourceIP = new byte[ipLength];
Array.Copy (data, position, sourceIP, 0, ipLength);
string sIP = string.Empty;
for (int i = 0; i < ipLength; i++)
{
sIP = string.Concat(sIP, sourceIP[i], ".");
}
m_sourceIP = IPAddress.Parse(sIP.Substring (0, sIP.Length - 1));
position += ipLength;
// copy out destination MAC
byte[] destMac = new byte[macLength];
Array.Copy (data, position, destMac, 0, macLength);
m_destMac = new MACAddress (destMac);
position += macLength;
// copy out destination IP
byte[] destIP = new byte[ipLength];
Array.Copy (data, position, destIP, 0, ipLength);
sIP = string.Empty;
for (int i = 0; i < ipLength; i++)
{
sIP = string.Concat(sIP, destIP[i], ".");
}
m_destIP = IPAddress.Parse(sIP.Substring (0, sIP.Length - 1));
position += ipLength;
}
/// <summary>
/// Resolve a physical address to an IP address.
/// </summary>
/// <param name="address">
/// The physical address to resolve.
/// </param>
/// <returns>
/// Returns the IP address belonging to the physical address.
/// </returns>
/// <exception cref="ObjectDisposedException">
/// If the object has already been disposed then an ObjectDisposedException
/// will be thrown
/// </exception>
/// <exception cref="Exception">
/// If the driver failed to start or was not bound, an exception will be thrown.
/// </exception>
public IPAddress ResolveMACAddress(MACAddress address)
{
if (m_disposed)
{
throw new ObjectDisposedException (this.ToString());
}
if (!m_driver.DriverStarted)
{
throw new Exception ("The driver has not been started.");
}
if (!m_driver.DriverBound)
{
throw new Exception ("The driver has not yet been bound to a device.");
}
Ethernet802_3 ethernet = new Ethernet802_3 ();
// construct the ethernet header
ethernet.SourceMACAddress = m_driver.BoundAdapter.MediaAccessControlAddress;
ethernet.DestinationMACAddress = MACAddress.BroadcastAddress;
ethernet.NetworkProtocol = NetworkLayerProtocol.ARP;
ArpPacket arp = new ArpPacket ();
// construct the ARP header
arp.Type = ArpOpcode.ReverseRequest;
arp.Protocol = NetworkLayerProtocol.IP;
arp.MediaType = MediaType.Ethernet;
arp.SourceMACAddress = ethernet.SourceMACAddress;
arp.SourceIPAddress = m_driver.BoundAdapter.Interfaces[0].Address;
arp.DestinationMACAddress = address;
// serialize and send the packet
ethernet.Data = arp.Serialize ();
m_driver.SendPacket (ethernet.Serialize ());
m_querying = true;
// wait for the reply
while (m_querying)
{
byte[] packet = m_driver.RecievePacket ();
Ethernet802_3 ethReply = new Ethernet802_3 (packet);
// if this is an ARP packet
if (ethReply.NetworkProtocol == NetworkLayerProtocol.ARP)
{
ArpPacket arpReply = new ArpPacket (ethReply.Data);
// if this is an ARP reply
if (arpReply.Type == ArpOpcode.Reply)
{
// if the address matches the one we requested
if (arpReply.DestinationIPAddress.Equals (address))
{
// return the IP address
return arpReply.DestinationIPAddress;
}
}
}
}
return IPAddress.Any;
}
/// <summary>
/// Returns the vendor given a MAC address.
/// </summary>
/// <param name="reader">
/// The XML text reader to use to read the file.
/// Use the oui.xml file included in the Data folder of the library or a
/// file with the same format. If the format is not correct then the
/// behaviour of this method is undefined. In other words, don't blame me
/// if it freezes or raises an exception, if you pass an incorrectly
/// formatted file.
/// </param>
/// <param name="address">
/// The MAC address whose vendor to find.
/// </param>
/// <returns>
/// The vendor name.
/// </returns>
public static string GetVender(XmlTextReader reader, MACAddress address)
{
// find the prefix
string macPrefix = address.ToString().Substring (0, 8).Replace (":", "-").ToLower();
// return value
string retVal = string.Empty;
// keep reading nodes
while (reader.Read ())
{
// if this is a MAC
if (reader.NodeType == XmlNodeType.Element && reader.Name == "MAC")
{
// read the next part
reader.Read ();
// if this is the MAC prefix
if (reader.NodeType == XmlNodeType.Text && reader.Value.ToLower() == macPrefix)
{
// keep reading until we find the vendor
while (reader.NodeType != XmlNodeType.Element || reader.Name != "Vendor")
{
reader.Read ();
}
reader.Read ();
retVal = reader.Value;
break;
}
else
{
reader.Skip ();
}
}
}
reader.Close ();
return retVal;
}
