Network Mates

Network discovery tool for local devices, combining multiple discovery methods.

Available as command-line and a simple gtk-based interface for Linux only.

Discovery Methods

Several discovery methods are used:

• OS known devices: sourced from routing, arp and rtnetlink neighbour tables. Resolves MAC addresses against OUI database (if installed)
• Port scanning: for commonly known ports across the ipv4 subnet will attempt a TCP connect, which is not meant to be invasive or an advanced scan.
• Broadcast listening: listens on commonly known ports (and quietly skips already bound or low port numbers unavailable for listening)
• SSDP: sends out a service discovery message and listens for ongoing notifications (if port 1900 is available)
• MDNS: sends out a service discovery requesting unicast responses, but also listening for multicast responses (if port 5353 is available)
• LSD: listening for notification of BitTorrent info hash
• Other common devices

For ipv6 neighbour discovery, there is no explicit solicitation of responses through ping or RA to avoid requiring a privileged NET_RAW operation. And also avoid calling an external application like ping. Instead, users can solicit all nodes through a basic ping to the all-node multicast address:

    $ ping ff02::1

Hosts who reply will then show up in netmates or through ip neighbour

Installing

Use one of the packages in the Releases section. Packaging typically produces .deb, .rpm and .tgz files

Building

If you prefer not to install the packaged release files, you can easily build on most common distributions

Dependencies:

These packages are required to build and run. They should be available on most distributions without additional installation. Specifically here are the corresponding Debian packages.

• libc
• glib-2 (usual package libglib2.0.0 and source libglib2.0-dev)
• gtk-3 (optional to compile GUI target, package libgtk-3 and source libgtk-3-dev)

Additionally, in order to resolve MAC address to their vendor names:

• ieee-data (provides oui.csv, or run sudo update-ieee-data if it's outdated. On distributions that don't have it, like Fedora, you can download the file directly to your .config directory with something like wget https://standards.ieee.org/develop/regauth/oui/oui.csv -O ~/.config/ieee-oui.csv)

Compiling

If the gtk-3 headers are detected through pkgconfig, the gui will be built too.

    cmake -B build
    cmake --build build

    sudo cmake --install build

Alternatively, add --prefix /usr or run it directly from build/ directory

Documentation

After installing, man netmates. Or from source you can read it with man doc/netmates.1

Issues

Open to details on more common services and devices, see the scan.c file for definition of which ports scanned and listened for.

To do

Potential future improvements

• Additional information
  • mdns: parse device-info TXT record for device model
  • process connect responses: nat-pmp public address, parse nbs scan for hostname
• Scan only required ports and report on actual ports to be scanned (filter defined ports)
  • Filter probes by method or service
• Classify hosts based on several services together at the end
  • Classify hosts by connect_ports open and SSDP/mDNS replies
  • Port combinations: 6667 broadcast and 6668/tcp open -> tuya
  • narrow down Alexa/iPhone
  • HW vendor to set host_type?
• avoid mixing C types and switch to standard?