We were previously using the netlink API to see if there are chains/rules that
already exist. This works fine in environments where there is either full
nftable support or no support at all. However, we have identified certain
environments which have partial nftable support and the only feasible way of
detecting such an environment is to try to create some of the chains that we
need.
This adds a check to create a dummy postrouting chain which is immediately
deleted. The goal of the check is to ensure we are able to use nftables and
that it won't error out later. This check is only done in the path where we
detected that the system has no preexisting nftable rules.
Updates #5621
Updates #8555
Updates #8762
Signed-off-by: Maisem Ali <maisem@tailscale.com>
These tests were broken at HEAD. CI currently does not run these
as root, will figure out how to do that in a followup.
Updates #5621
Updates #8555
Updates #8762
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Just a refactor to consolidate the firewall detection logic in a single
package so that it can be reused in a later commit by containerboot.
Updates #9310
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Add an explicit accept rule for input to the tun interface, as a mirror
to the explicit rule to accept output from the tun interface.
The rule matches any packet in to our tun interface and accepts it, and
the rule is positioned and prioritized such that it should be evaluated
prior to conventional ufw/iptables/nft rules.
Updates #391Fixes#7332
Updates #9084
Signed-off-by: James Tucker <james@tailscale.com>
This commit tries to mimic the way iptables-nft work with the filewall rules. We
follow the convention of using tables like filter, nat and the conventional
chains, to make our nftables implementation work with ufw.
Updates: #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
This commit adds nftable rule injection for tailscaled. If tailscaled is
started with envknob TS_DEBUG_USE_NETLINK_NFTABLES = true, the router
will use nftables to manage firewall rules.
Updates: #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
