PNDPD - NDP Responder + Proxy

Features

• Efficiently process incoming packets using bpf (which runs in the kernel)
• Respond to all NDP solicitations on an interface
• Respond to NDP solicitations for whitelisted addresses on an interface
• Proxy NDP between interfaces with an optional whitelist
• Optionally determine whitelist automatically based on the IPs assigned to the interfaces
• Permissions required: root or CAP_NET_RAW
• Easily expandable with modules

Installing & Updating

1. Download the latest release from the releases page and move the binary to the /usr/local/bin/ directory under the filename pndpd.
2. Allow executing the file by running chmod +x /usr/local/bin/pndpd
3. For systemd users: Install the service unit file

wget https://raw.githubusercontent.com/Kioubit/pndpd/master/pndpd.service -P /etc/systemd/system/
systemctl enable pndpd.service

4. Download and install the config file

mkdir -p /etc/pndpd
wget https://raw.githubusercontent.com/Kioubit/pndpd/master/pndpd.conf -P /etc/pndpd/

5. Edit the config at /etc/pndpd/pndpd.conf and then start the service using service pndpd start

Manual Usage

pndpd config <path to file>
pndpd responder <interface> <optional whitelist of CIDRs separated by a semicolon>
pndpd proxy <interface1> <interface2> <optional whitelist of CIDRs separated by a semicolon applied to interface2>

More options and additional documentation in the example config file (pndpd.conf).

Developing

Building

For building, the version of go needs to be installed that is specified in the go.mod file. A makefile is available. Optionally adjust the MODULES variable to include or exclude modules from the modules directory.

make clean
make release-all

Find the binaries in the bin/ directory

Adding Modules

It is easy to add functionality to PNDPD. For additions outside the core functionality you only need to keep the following methods in mind:

package main
import "pndpd/pndp"

pndp.ParseFilter(f string) []*net.IPNet

responderInstance := pndp.NewResponder(iface string, filter []*net.IPNet, autosenseInterface string)
responderInstance.Start()
responderInstance.Stop()

proxyInstance := pndp.NewProxy(iface1 string, iface2 string, filter []*net.IPNet, autosenseInterface string)
proxyInstance.Start()
proxyInstance.Stop()

New functionality should be implemented as a module. You will find an example module under modules/example/.

Pull requests are welcome for any functionality you add.