There are container environments such as GitHub codespaces that have
partial IPv6 support - routing support is enabled at the kernel level,
but lacking IPv6 filter support in the iptables module.
In the specific example of the codespaces environment, this also has
pre-existing legacy iptables rules in the IPv4 tables, as such the
nascent firewall mode detection will always pick iptables.
We would previously fault trying to install rules to the filter table,
this catches that condition earlier, and disables IPv6 support under
these conditions.
Updates #5621
Updates #11344
Updates #11354
Signed-off-by: James Tucker <james@tailscale.com>
Ensure that the latest DNATNonTailscaleTraffic rule
gets inserted on top of any pre-existing rules.
Updates tailscale/tailscale#11281
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Ensure that if getOrCreateChain creates a new chain, it actually returns the created chain
Updates tailscale/tailscale#10399
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
* util/linuxfw, wgengine: allow ingress to magicsock UDP port on Linux
Updates #9084.
Currently, we have to tell users to manually open UDP ports on Linux when
certain firewalls (like ufw) are enabled. This change automates the process of
adding and updating those firewall rules as magicsock changes what port it
listens on.
Signed-off-by: Naman Sood <mail@nsood.in>
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>
This migrates containerboot to reuse the NetfilterRunner used
by tailscaled instead of manipulating iptables rule itself.
This has the added advantage of now working with nftables and
we can potentially drop the `iptables` command from the container
image in the future.
Updates #9310
Co-authored-by: Irbe Krumina <irbe@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This allows using the fake runner in different packages
that need to manage filter rules.
Updates #cleanup
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>
Appears to be a missing nil handling case. I looked back over other
usage of findRule and the others all have nil guards. findRule returns
nil when no rules are found matching the arguments.
Fixes#9553
Signed-off-by: James Tucker <james@tailscale.com>
Replace %w verb with %v verb when logging errors.
Use %w only for wrapping errors with fmt.Errorf()
Fixes: #9213
Signed-off-by: Craig Rodrigues <rodrigc@crodrigues.org>
And flesh it out and use idiomatic doc style ("whether" for bools)
and end in a period while there anyway.
Updates #cleanup
Change-Id: Ieb82f13969656e2340c3510e7b102dc8e6932611
Signed-off-by: Brad Fitzpatrick <bradfitz@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>
Go style is for error variables to start with "err" (or "Err")
and for error types to end in "Error".
Updates #cleanup
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit replaces the TS_DEBUG_USE_NETLINK_NFTABLES envknob with
a TS_DEBUG_FIREWALL_MODE that should be set to either 'iptables' or
'nftables' to select firewall mode manually, other wise tailscaled
will automatically choose between iptables and nftables depending on
environment and system availability.
updates: #319
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
The util/linuxfw/iptables.go had a bunch of code that wasn't yet used
(in prep for future work) but because of its imports, ended up
initializing code deep within gvisor that panicked on init on arm64
systems not using 4KB pages.
This deletes the unused code to delete the imports and remove the
panic. We can then cherry-pick this back to the branch and restore it
later in a different way.
A new test makes sure we don't regress in the future by depending on
the panicking package in question.
Fixes#8658
Signed-off-by: Brad Fitzpatrick <bradfitz@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>
Exclide GOARCHs including: mips, mips64, mips64le, mipsle, riscv64.
These archs are not supported by gvisor.dev/gvisor/pkg/hostarch.
Fixes: #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
This change is introducing new netfilterRunner interface and moving iptables manipulation to a lower leveled iptables runner.
For #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
This isn't currently supported due to missing support in upstream
dependencies, and also we don't use this package anywhere right now.
Just conditionally skip this for now.
Fixes#7268
Change-Id: Ie7389c2c0816b39b410c02a7276051a4c18b6450
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This package is an initial implementation of something that can read
netfilter and iptables rules from the Linux kernel without needing to
shell out to an external utility; it speaks directly to the kernel using
syscalls and parses the data returned.
Currently this is read-only since it only knows how to parse a subset of
the available data.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Change-Id: Iccadf5dcc081b73268d8ccf8884c24eb6a6f1ff5
