void Send_DHCPRequest(DHCPPacket packet, byte[] dhcpserver, int type)
{
/*
* type = 1: selecting
* type = 2: renew, bound, rebind
* type = 3: reboot
*/
// send dhcp request
DHCPPacket n_packet = new DHCPPacket();
n_packet.Init();
n_packet.op = 1;
n_packet.htype = 1;
n_packet.hlen = 6;
n_packet.hops = 0;
for (int i = 0; i < packet.xid.Length; i++)
{
n_packet.xid[i] = packet.xid[i];
}
xid.Add(ByteArrayToString(packet.xid));
if (type == 2)
{
n_packet.ciaddr = ip.GetAddressBytes();
}
for (int i = 0; i < MacAddr.Length; i++)
{
n_packet.chaddr[i] = MacAddr[i];
}
option op_field = new option();
op_field.add(new byte[] { 99, 139, 83, 99 }); // add dhcp magic option
op_field.add(new byte[] { 53, 1, 3 }); // add messeage type dhcp request
if (type == 1 || type == 3)
{
op_field.add(new byte[] { 50, 4 }); // add request ip address
op_field.add(packet.yiaddr); // ip address
}
if (type == 1)
{
op_field.add(new byte[] { 54, 4 }); // add dhcp server identify
op_field.add(dhcpserver); // add dhcp server identify
}
op_field.add(new byte[] { 55, 3, 1, 3, 6 }); // add parament request list
op_field.add(new byte[] { 255 }); // add end
n_packet.options = new byte[op_field.size];
for (int i = 0; i < op_field.size; i++)
{
n_packet.options[i] = op_field.data[i];
}
//
SendPacket(n_packet);
}
void Send_DHCPAck(DHCPPacket packet, IPAddress IP) // take dhcp discover and allocated ip and send offer packet
{
// send dhcp offer
DHCPPacket n_packet = new DHCPPacket();
n_packet.Init();
n_packet.op = 2;
n_packet.htype = 1;
n_packet.hlen = 6;
n_packet.hops = 0;
for (int i = 0; i < packet.xid.Length; i++)
{
n_packet.xid[i] = packet.xid[i];
}
n_packet.yiaddr = IP.GetAddressBytes();
for (int i = 0; i < packet.flags.Length; i++)
{
n_packet.flags[i] = packet.flags[i];
}
for (int i = 0; i < packet.giaddr.Length; i++)
{
n_packet.giaddr[i] = packet.giaddr[i];
}
for (int i = 0; i < packet.chaddr.Length; i++)
{
n_packet.chaddr[i] = packet.chaddr[i];
}
option op_field = new option();
op_field.add(new byte[] { 99, 139, 83, 99 }); // add dhcp magic option
op_field.add(new byte[] { 53, 1, 5 }); // add messeage type dhcp ack
op_field.add(new byte[] { 54, 4 }); // add dhcp server identify
op_field.add(network_config.dhcpserver.GetAddressBytes());
op_field.add(new byte[] { 51, 4, (byte)(network_config.leasetime), (byte)(network_config.leasetime >> 8), (byte)(network_config.leasetime >> 16), (byte)(network_config.leasetime >> 24) }); // add ip lease time (120 s)
op_field.add(new byte[] { 1, 4 }); // add subnetmask
op_field.add(network_config.subnetmask.GetAddressBytes());
op_field.add(new byte[] { 3, 4 }); // add defualt gateway
op_field.add(network_config.defaultgateway.GetAddressBytes());
op_field.add(new byte[] { 6, 4 }); // add dns server
op_field.add(network_config.dns.GetAddressBytes());
op_field.add(new byte[] { 255 }); // add end
n_packet.options = new byte[op_field.size];
for (int i = 0; i < op_field.size; i++)
{
n_packet.options[i] = op_field.data[i];
}
//
SendPacket(n_packet);
}
void Send_DHCPRelease()
{
// send dhcp release
DHCPPacket packet = new DHCPPacket();
packet.Init();
packet.op = 1;
packet.htype = 1;
packet.hlen = 6;
packet.hops = 0;
Random _random = new Random();
packet.xid[0] = (byte)_random.Next(0, 255);
packet.xid[1] = (byte)_random.Next(0, 255);
packet.xid[2] = (byte)_random.Next(0, 255);
packet.xid[3] = (byte)_random.Next(0, 255);
packet.ciaddr = ip.GetAddressBytes();
for (int i = 0; i < MacAddr.Length; i++)
{
packet.chaddr[i] = MacAddr[i];
}
option op_field = new option();
op_field.add(new byte[] { 99, 139, 83, 99 }); // add dhcp magic option
op_field.add(new byte[] { 53, 1, 7 }); // add messeage type dhcp request
op_field.add(new byte[] { 54, 4 }); // add dhcp server identify
op_field.add(DHCPServer_IP);
op_field.add(new byte[] { 255 });
packet.options = new byte[op_field.size];
for (int i = 0; i < op_field.size; i++)
{
packet.options[i] = op_field.data[i];
}
//
SendPacket(packet);
haveip = false;
ip = IPAddress.Parse("0.0.0.0");
defaultgateway = IPAddress.Parse("0.0.0.0");
subnetmask = IPAddress.Parse("255.255.255.255");
dns = IPAddress.Parse("0.0.0.0");
time = 0;
DHCPServer_IP = new byte[] { 0, 0, 0, 0 };
}
void Send_DHCPNak(DHCPPacket packet) // take dhcp discover and allocated ip and send offer packet
{
// send dhcp NACK
DHCPPacket n_packet = new DHCPPacket();
n_packet.Init();
n_packet.op = 2;
n_packet.htype = 1;
n_packet.hlen = 6;
n_packet.hops = 0;
for (int i = 0; i < packet.xid.Length; i++)
{
n_packet.xid[i] = packet.xid[i];
}
for (int i = 0; i < packet.flags.Length; i++)
{
n_packet.flags[i] = packet.flags[i];
}
for (int i = 0; i < packet.giaddr.Length; i++)
{
n_packet.giaddr[i] = packet.giaddr[i];
}
for (int i = 0; i < packet.chaddr.Length; i++)
{
n_packet.chaddr[i] = packet.chaddr[i];
}
option op_field = new option();
op_field.add(new byte[] { 99, 139, 83, 99 }); // add dhcp magic option
op_field.add(new byte[] { 53, 1, 6 }); // add messeage type dhcp nack
op_field.add(new byte[] { 54, 4 }); // add dhcp server identify
op_field.add(network_config.dhcpserver.GetAddressBytes());
op_field.add(new byte[] { 255 }); // add end
n_packet.options = new byte[op_field.size];
for (int i = 0; i < op_field.size; i++)
{
n_packet.options[i] = op_field.data[i];
}
//
SendPacket(n_packet);
}
} // Chuyen tu byte array sang string
void Send_DHCPDiscover()
{
// send dhcp discover
DHCPPacket packet = new DHCPPacket();
packet.Init();
packet.op = 1;
packet.htype = 1;
packet.hlen = 6;
packet.hops = 0;
Random _random = new Random();
packet.xid[0] = (byte)_random.Next(0, 255);
packet.xid[1] = (byte)_random.Next(0, 255);
packet.xid[2] = (byte)_random.Next(0, 255);
packet.xid[3] = (byte)_random.Next(0, 255);
xid.Add(ByteArrayToString(packet.xid));
for (int i = 0; i < MacAddr.Length; i++)
{
packet.chaddr[i] = MacAddr[i];
}
option op_field = new option();
op_field.add(new byte[] { 99, 139, 83, 99 }); // add dhcp magic option
op_field.add(new byte[] { 53, 1, 1 }); // add messeage type dhcp discover
op_field.add(new byte[] { 55, 3, 1, 3, 6 }); // add parament request list
op_field.add(new byte[] { 255 }); // add end
packet.options = new byte[op_field.size];
for (int i = 0; i < op_field.size; i++)
{
packet.options[i] = op_field.data[i];
}
//
SendPacket(packet);
}