* util/linuxfw: fix IPv6 NAT availability check for nftables
When running firewall in nftables mode,
there is no need for a separate NAT availability check
(unlike with iptables, there are no hosts that support nftables, but not IPv6 NAT - see tailscale/tailscale#11353).
This change fixes a firewall NAT availability check that was using the no-longer set ipv6NATAvailable field
by removing the field and using a method that, for nftables, just checks that IPv6 is available.
Updates tailscale/tailscale#12008
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
* cmd/containerboot,util/linuxfw: support proxy backends specified by DNS name
Adds support for optionally configuring containerboot to proxy
traffic to backends configured by passing TS_EXPERIMENTAL_DEST_DNS_NAME env var
to containerboot.
Containerboot will periodically (every 10 minutes) attempt to resolve
the DNS name and ensure that all traffic sent to the node's
tailnet IP gets forwarded to the resolved backend IP addresses.
Currently:
- if the firewall mode is iptables, traffic will be load balanced
accross the backend IP addresses using round robin. There are
no health checks for whether the IPs are reachable.
- if the firewall mode is nftables traffic will only be forwarded
to the first IP address in the list. This is to be improved.
* cmd/k8s-operator: support ExternalName Services
Adds support for exposing endpoints, accessible from within
a cluster to the tailnet via DNS names using ExternalName Services.
This can be done by annotating the ExternalName Service with
tailscale.com/expose: "true" annotation.
The operator will deploy a proxy configured to route tailnet
traffic to the backend IPs that service.spec.externalName
resolves to. The backend IPs must be reachable from the operator's
namespace.
Updates tailscale/tailscale#10606
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
MSS clamping for nftables was mostly not ran due to to an earlier rule in the FORWARD chain issuing accept verdict.
This commit places the clamping rule into a chain of its own to ensure that it gets ran.
Updates tailscale/tailscale#11002
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
We have hosts that support IPv6, but not IPv6 firewall configuration
in iptables mode.
We also have hosts that have some support for IPv6 firewall
configuration in iptables mode, but do not have iptables filter table.
We should:
- configure ip rules for all hosts that support IPv6
- only configure firewall rules in iptables mode if the host
has iptables filter table.
Updates tailscale/tailscale#11540
Signed-off-by: Irbe Krumina <irbe@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>
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>
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>
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>
