letmein

Changes:

• Move compilation of seccomp program to build.rs.

Fixes:

• Remove sigaction from allowed syscalls.

• The daemon has been split into a privileged part for the firewall and a public network facing part with reduced privileges. Please see README.md for instructions about how to install the required user.
• Optional Linux seccomp support for the network daemon has been added. See the example letmeind.conf file for how to enable it.

• It is now possible to restrict ports to a subset of users, so that only certain users can knock certain ports open. See the example config files. By default all ports can be knocked by all users.
• A sanity check for the passed systemd socket has been added.
• Parts of the code have been simplified and cleaned up.

• An optional limit for the maximum number of connections has been added. Default = 8.
• The configparser crate dependency has been removed. No functional change.