My main reason for adding this is the ability to turn off helpers
altogether. If you are not using any of the special protocols, keeping
them turned off is safest, and in case you do want to use them, it's
best to configure them through the new CT target for your network
topology. Perhaps some sane defaults for nixos can be examined in the
future.
This change has no impact if you don't touch the added options, so no
need to adapt.
This is meant to replace /proc/sys/net/ipv4/conf/*/rp_filter, which
only works for ipv4. Furthermore, it's nicer to handle this kind of
filtering in the firewall.
There are some more subtle differences, please see:
https://home.regit.org/netfilter-en/secure-use-of-helpers/
I chose to enable this by default (when the firewall is enabled) as
it's a good idea in general. Only people with advanced routing needs
might not want this, but I guess they don't use the nixos firewall
anyway and use a custom solution. Furthermore, the option only becomes
available in kernel 3.3+, so conservative nixos users that just stick
to the default kernel will not need to act now just yet.
The special handling for cronjobs should probably move to the cron
module (logcheckIgnore = bool option) in the future, as it's more
natural to just declare a cronjob, and mark it as "log-ignored",
instead of adding cronjobs through logcheck.
But as systemCronjobs is not an attrset yet (just simple strings),
this would require adding an attrset for cronjobs or parsing strings
in the nix language to get hold of the cron-user and command.
So for now, I keep the interface within logcheck's module.
This is broken because it requires restarting applications to see new
NSS modules. The proper way to handle NSS modules is through nscd.
See commit 554ae9908b.
When spamd isn't running as 'root', it cannot access the usual ~/.spamassassin
path where user-specific files normally reside. Instead, we use the path
/var/lib/spamassassin-<user> to store those home directories.
* Add group 'networkmanager' and implement polkit configuration
that allows users in this group to make persistent, system-wide
changes to NetworkManager settings.
* Add support for ModemManager. 3G modems should work out of the
box now (it does for me...). This introduces a dependency on
pkgs.modemmanager.
* Write NetworkManger config file to Nix store, and let the
daemon use it from there.
It specifies what mingetty will be stopped, if a bad filesystem
triggers an emergency shell.
That should be ttyS0 on headless systems, and in that case,
nixos should stop the ttyS0 mingetty from getting in.
I had some problems with LDAP user lookups not working properly
at boot. I found that invalidating passwd and group on the
ip-up event (when nscd-invalidate starts) helped a bit.
kernel 3.4+ needs cifs-utils to mount CIFS filesystems.
the kernel itself (and busybox's cifs mount code) are no longer able
to do this in some/most cases and will error out saying:
"CIFS VFS: connecting to DFS root not implemented yet"
Nixos' qemu-vm target is hurt by this, as it wants to mount /nix/store
via cifs very early in the boot process.
This commit makes sure the initrd for affected kernels is built with
cifs-utils if needed.
proxy_arp (and proxy_ndp for ipv6) can be turned on on a few
interfaces (at least 2).
This is mainly useful for creating pseudo-bridges between a real
interface and a virtual network such as VPN or a virtual machine for
interfaces that don't support real bridging (most wlan interfaces).
As ARP proxying acts slightly above the link-layer, below-ip traffic
isn't bridged, so things like DHCP won't work. The advantage above
using NAT lies in the fact that no IP addresses are shared, so all
hosts are reachable/routeable.
