knockd

A simple port knocking daemon written in C++

Building

export CPP=your-compiler-of-choice FILE_INCLUDES='-I/path/to/libpcap/include' LINK_INCLUDES='-L/path/to/libpcap/lib'

make

Running

Listen on eth0 for udp packets. Read from stdin

./knockd -i eth0 -p udp -s < ports

Specifying a file to read port sequence from

./knockd -i eth0 -p udp -f ports

# the above is equivalent to
./knockd -i eth0 -p udp -s < ports

Listen on eth0 for tcp packets. Randomly generate sequence and write to file named generated

./knockd -i eth0 -p tcp -g generated

• The file generated can be re-used now. The following two commands are equivalent:

./knockd -i eth0 -p tcp -s < generated

# or
./knockd -i eth0 -p tcp -f generated

Format of generated port sequences

If you use -g file, a port sequence will be written to file. 64 ports will be written. One port per line. The file will have linux newlines (\n).

Future as a library

Core functionality has been moved to lib/knockd.hpp. It is possible to use this file as a header-only import in your projects. The example code is in main.cpp. At some point, I'll get around to creating doxygen documentation for the library interface.

Version

v2.0.0