Comment 3 for bug 1862157

Hi Thomas,
as you already described yourself if you set in /etc/dnsmasq.conf
 tftp-root=/
then all paths you provide in per subnet config would work if each of them were added as absolute path.
This works as-is without any change to the package.

`tftp-root` is defined as:
--tftp-root=<directory>[,<interface>]
Look for files to transfer using TFTP relative to the given directory. When this is set, TFTP paths which include ".." are rejected, to stop clients getting outside the specified root. Absolute paths (starting with /) are allowed, but they must be within the tftp-root. If the optional interface argument is given, the directory is only used for TFTP requests via that interface.

Your example violates the "paths starting with / ... must be within the tftp-root" which is why it won't work. You could also just "not at all" set `tftp-root` as it is mostly a security feature to not serve something you'd never want to be served.

You can even do "per IP paths" in between with tftp-root + --tftp-unique-root - see the manpage for more details.

If all those config options aren't enough this is more a feature request to dnsmasq than a bug in Ubuntu. Go to [1] for that if you like to do so.

[1]: http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss