My take on a network manager

📆: 23 Feb 2018
🏷: Openbsd, Netmanager

There’s one thing that I am really missing under OpenBSD, a network manager which seemlessly handles running around with my laptop. So my main itches to scratch are doing magic things at boot and resume so I don’t have to bother with fiddling with hostname.if(5) ever.

My first take on tackling that problem actually was working ok’ish but depended on sqlite3 and after sqlite3 left base the solution started to annoy me everytime I moved to a current snapshot and sqlite3 stoppped working or was unavailable from within bsd.rd.

So I started to look around what other people did to get rid of those problems which led me to netctl. I like that netctl is nothing but a shell script. I dislike that it didn’t work at boot time.

As my first take already worked at boot time, reducing my hostname.if(5) to being only 2 lines:

up
!/etc/netmanager \$if

I decided to rewrite the script, reusing chunks of netstart(8) in order to keep the fileformat in a well-known format. /etc/netmanager basically searches below /etc/hostname.d for a file matching the given – or autodetected – network ID to connect to. So without further ado here it is:

#!/bin/sh -

# parse_hn_line() and ifstart() are taken from /etc/netstart revision 1.195 with
# some small additions (basically addition of $_nwid and the removal of unneeded routines)

set +o sh

usage() {
	cat <<EOF >&2
usage: /etc/netmanager [<nwid>] <if>
	<nwid>	network to connect to
	<if>	interface to connect

netmanager searches for <nwid>.nwid in /etc/hostname.d, parses the file and
feeds ifconfig(8) accordingly. <nwid>.nwid has the same format as hostname.if(5).

If no <nwid> has been given netmanager issues a scan for access points and
searches for a matching <nwid>.nwid file.
EOF
	exit 2
}

# Parse and "unpack" a hostname.if(5) line given as positional parameters.
# Fill the _cmds array with the resulting interface configuration commands. …

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