MindYourNeighbors

Launching scripts depending on you direct neighbors

How ?

MindYourNeighbors basically parse the ip-neighbor and, if results are found that are not excluded by the configuration, a configured command will be launched once.

Why ?

The original use case :

A linux box used as a router as well as a home server. On this box runs several pieces of software which can be very bandwith consuming (ie: transmission). I wanted to shut down this software when other users were using the network.

Features

MindYourNeighbors behavior's can be controlled through configuration file placed either in ~/.config/mind_your_neighbords.cfg or in /etc/mind_your_neighbords.cfg.

The configuration file is organized in sections. The DEFAULT section holds the default options which will be inherited by all the other sections (except for the logging level and the cache file path). All the other section will be read one by one ; each time the condition defined in filter_on_regex or filter_on_machine is matched and isn't excluded by those defined in neither exclude, filter_out_regex or filter_out_machine the cache will be filled with either a marker neighbor or a marker no neighbor.

Cache length can't exceed the threshold, as only the REACHABLE lines in the result of the ip neigh command are taken in account and as those lines vary quite a bit, the threshold parameter allows you to configure how quickly a change of state can occure.

When the cache is filled the only neighbor or no neighbor markers, the corresponding command is executed once.

Known Machines

You can fill a section with known_machine as title in which you'll write the name and mac address of machine you're aware of. You'll then be able to filter them out or in through filter_out_machine and filter_on_machine.

Please refer to the configuration example file for practical use cases.

Options list

Default section options

• loglevel: allows you to choose the verbosity level in the syslog between DEBUG, INFO, WARN, ERROR and FATAL.
• cache_file: the path to the file where MindYourNeighbors will store its cache.

By sections, overridable options

• threshold: the number of consecutive matches (or un matches) it takes for MindYourNeighbors to execute the "match" or "no match" command.
• filter_on_regex: a regex to filters lines from the ip neigh command, lines will have to match to be counted
• filter_out_regex: a regex to filters lines from the ip neigh command, matching line will be excluded
• exclude: a comma separated list of string. If one of those string should be found in a ip neigh line, it should be excluded.
• filter_on_machine: a comma separated list of machine names to filter in (they must be registered in known_machine)
• filter_out_machine: a comma separated list of machine names to filter out (they must be registered in known_machine)
• command_match: A command to execute when the cache has been filed with neighbor marker.
• command_no_match: A command to execute when the cache has been filed with no neighbor marker.
• device: if none provide the ip neigh command will be parsed else ip neigh show dev <device>.
• enable: a boolean (true or false), enabling or disabling a section.
• error_on_stderr: a boolean (true or false); if true and the command print something on stderr, the command will be ignored and executed again.
• cron: a cron styled time description in which the section will be activated