pydhcp - a dhcp command line tool
pydhcp --input <TYPE;OPTIONS;NAME> --output <TYPE;OPTIONS;NAME>
pydhcp is a command line tool to read or write dhcp packet on network, and
translate from raw data to human readable informations (and vice-et-versa).
pydhcp is a part of the pydhcplib python library.
pydhcp takes an input and an output argument. Input and output are described in
the same way. For example :
pydhcp --input 'device;binary|up;eth0:68' --output 'file;readable;myfile.txt' -c
There is 5 types for the <TYPE> field. Only one type at once can be used :
device, address, file, stdin and stdout. device tells pydhcp to write or
listen directly on the network interface and port. address is to write or
listen on a specific Internet Address and port (like 192.168.1.1:67 ). file
read or write data from or to a file. stdin read data from stdin, stdout write
data on stdout.
You can use multiple options in the option field by separate them with a pipe |.
There is 4 options for this field : readable, binary, up and noup. readable id
to read or write data in a human readable language : a packet definition
language. This language is described later. Binary form stand for reading or
writing packets in the same binary form they are on the network : an UDP
packet. readable and binary are mutually exclusive. Option up tells pydhcp to
set the network interface up if not. noup tells not to set up the interface.
up and noup are only useful in combination with the device type. Default is
Describe the name of the device (eth0:67,wlan0:client) , the address
(192.168.1.1), or the filename (foo.txt). You can use a port number or the
keywords client and server for standard dhcp port.
Option -c : Number of packet to read or write. 0 for unlimited number of packet.
Default is 0.
- Only one dhcp packet per file, then count is set to 1 for file I/O - No
readable transfert on network (address or device). Binary only.
- Number of packets to process.
Read a client packet on any address and write it on a human readable file :
pydhcp -i "address;binary;0.0.0.0:67" -o
Read a binary dhcp packet from a file and print it on stdout in a human readable
pydhcp -i "file;binary;myfile.bin" -o "stdout;readable;"
Mathieu Ignacio (mignacio[AT]april.org)