/// <summary> Convert captured packet data into an object.</summary>
public static Packet dataToPacket(LinkLayers linkType, byte[] bytes, Timeval tv)
{
EthernetPacketType ethProtocol;
// retrieve the length of the headers associated with this link layer type.
// this length is the offset to the header embedded in the packet.
int byteOffsetToEthernetPayload = LinkLayer.LinkLayerLength(linkType);
// extract the protocol code for the type of header embedded in the
// link-layer of the packet
int offset = LinkLayer.ProtocolOffset(linkType);
if (offset == -1)
{
// if there is no embedded protocol, assume IpV4
ethProtocol = EthernetPacketType.IPv4;
}
else
{
ethProtocol = (EthernetPacketType)ArrayHelper.extractInteger(bytes, offset, EthernetFields_Fields.ETH_CODE_LEN);
}
string errorString;
Packet parsedPacket = null;
try
{
// try to recognize the ethernet type..
switch (ethProtocol)
{
// arp
case EthernetPacketType.ARP:
parsedPacket = new ARPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case EthernetPacketType.IPv6:
case EthernetPacketType.IPv4:
try
{
// ethernet level code is recognized as IP, figure out what kind..
int ipProtocol = IPProtocol.extractProtocol(byteOffsetToEthernetPayload, bytes);
switch (ipProtocol)
{
case (int)IPProtocol.IPProtocolType.ICMP:
parsedPacket = new ICMPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.IGMP:
parsedPacket = new IGMPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.TCP:
parsedPacket = new TCPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.UDP:
parsedPacket = new UDPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
// unidentified ip..
default:
parsedPacket = new IPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
}
// check that the parsed packet is valid
if (!parsedPacket.IsValid(out errorString))
{
throw new PcapException(errorString);
}
else
{
return parsedPacket;
}
}
catch
{
// error parsing the specific ip packet type, parse as a generic IPPacket
parsedPacket = new IPPacket(byteOffsetToEthernetPayload, bytes, tv);
// check that the parsed packet is valid
if (!parsedPacket.IsValid(out errorString))
{
throw new PcapException(errorString);
}
else
{
return parsedPacket;
}
}
// ethernet level code not recognized, default to anonymous packet..
default:
parsedPacket = new EthernetPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
}
return parsedPacket;
}
catch
{
// we know we have at least an ethernet packet, so return that
return new EthernetPacket(byteOffsetToEthernetPayload, bytes, tv);
}
}
internal static void UpdateArpNode(TreeView treeView, ARPPacket arpPacket)
{
TreeNode arpNode = treeView.Nodes["ARP"];
if (arpNode == null)
{
arpNode = AddArpNode(treeView);
}
arpNode.Text = String.Format("Address Resolution Protocol ({0})", DataStructures.GetARPOpDescription(arpPacket.ARPOperation));
arpNode.Nodes["HwType"].Text = String.Format("Hardware type: {0} (0x{1:X4})", DataStructures.GetARPHwTypeDescription(arpPacket.ARPHwType), arpPacket.ARPHwType);
arpNode.Nodes["ProtocolType"].Text = String.Format("Protocol type: {0} (0x{1:X4})", DataStructures.GetEtherTypeDescription((EthernetPacketType)arpPacket.ARPProtocolType), arpPacket.ARPProtocolType);
arpNode.Nodes["HwSize"].Text = String.Format("Hardware size: {0}", arpPacket.ARPHwLength);
arpNode.Nodes["ProtocolSize"].Text = String.Format("Protocol size: {0}", arpPacket.ARPProtocolLength);
arpNode.Nodes["Opcode"].Text = String.Format("Operation: {0} (0x{1:X4})", DataStructures.GetARPOpDescription(arpPacket.ARPOperation), arpPacket.ARPOperation);
arpNode.Nodes["SenderHwAddress"].Text = String.Format("Sender MAC address: {0}", GetHyphenatedHwAddress(arpPacket.ARPSenderHwAddress));
arpNode.Nodes["SenderIPAddress"].Text = String.Format("Sender IP address: {0}", arpPacket.ARPSenderProtoAddress);
arpNode.Nodes["TargetHwAddress"].Text = String.Format("Target MAC address: {0}", GetHyphenatedHwAddress(arpPacket.ARPTargetHwAddress));
arpNode.Nodes["TargetIPAddress"].Text = String.Format("Target IP address: {0}", arpPacket.ARPTargetProtoAddress);
}
private ARPPacket BuildARP(PhysicalAddress localMAC, System.Net.IPAddress localIP)
{
ARPPacket arp = new ARPPacket(14, new byte[60]);
// arp fields
arp.ARPHwLength = 6;
arp.ARPHwType = ARPFields_Fields.ARP_ETH_ADDR_CODE;
arp.ARPProtocolLength = 4;
arp.ARPProtocolType = ARPFields_Fields.ARP_IP_ADDR_CODE;
arp.ARPSenderHwAddress = localMAC;
arp.ARPSenderProtoAddress = localIP;
// ether fields
arp.SourceHwAddress = localMAC;
arp.EthernetProtocol = EthernetPacket.EtherType.ARP;
return arp;
}
/// <summary> Convert captured packet data into an object.</summary>
public static Packet dataToPacket(LinkLayers linkType, byte[] bytes, Timeval tv)
{
EthernetPacketType ethProtocol;
// retrieve the length of the headers associated with this link layer type.
// this length is the offset to the header embedded in the packet.
int byteOffsetToEthernetPayload = LinkLayer.LinkLayerLength(linkType);
// extract the protocol code for the type of header embedded in the
// link-layer of the packet
int offset = LinkLayer.ProtocolOffset(linkType);
if (offset == -1)
{
// if there is no embedded protocol, assume IpV4
ethProtocol = EthernetPacketType.IPv4;
}
else
{
ethProtocol = (EthernetPacketType)ArrayHelper.extractInteger(bytes, offset, EthernetFields_Fields.ETH_CODE_LEN);
}
string errorString;
Packet parsedPacket = null;
try
{
// try to recognize the ethernet type..
switch (ethProtocol)
{
// arp
case EthernetPacketType.ARP:
parsedPacket = new ARPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case EthernetPacketType.IPv6:
case EthernetPacketType.IPv4:
try
{
// ethernet level code is recognized as IP, figure out what kind..
int ipProtocol = IPProtocol.extractProtocol(byteOffsetToEthernetPayload, bytes);
switch (ipProtocol)
{
case (int)IPProtocol.IPProtocolType.ICMP:
parsedPacket = new ICMPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.IGMP:
parsedPacket = new IGMPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.TCP:
parsedPacket = new TCPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
case (int)IPProtocol.IPProtocolType.UDP:
parsedPacket = new UDPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
// unidentified ip..
default:
parsedPacket = new IPPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
}
// check that the parsed packet is valid
if (!parsedPacket.IsValid(out errorString))
{
throw new PcapException(errorString);
}
else
{
return(parsedPacket);
}
}
catch
{
// error parsing the specific ip packet type, parse as a generic IPPacket
parsedPacket = new IPPacket(byteOffsetToEthernetPayload, bytes, tv);
// check that the parsed packet is valid
if (!parsedPacket.IsValid(out errorString))
{
throw new PcapException(errorString);
}
else
{
return(parsedPacket);
}
}
// ethernet level code not recognized, default to anonymous packet..
default:
parsedPacket = new EthernetPacket(byteOffsetToEthernetPayload, bytes, tv);
break;
}
return(parsedPacket);
}
catch
{
// we know we have at least an ethernet packet, so return that
return(new EthernetPacket(byteOffsetToEthernetPayload, bytes, tv));
}
}
