Commit Graph

28 Commits (23880eb5b05368d30023f91c314c9cc2e19f4a90)

Author SHA1 Message Date
Irbe Krumina 9bd158cc09
cmd/containerboot,util/linuxfw: create a SNAT rule for dst/src only once, clean up if needed (#13658)
The AddSNATRuleForDst rule was adding a new rule each time it was called including:
- if a rule already existed
- if a rule matching the destination, but with different desired source already existed

This was causing issues especially for the in-progress egress HA proxies work,
where the rules are now refreshed more frequently, so more redundant rules
were being created.

This change:
- only creates the rule if it doesn't already exist
- if a rule for the same dst, but different source is found, delete it
- also ensures that egress proxies refresh firewall rules
if the node's tailnet IP changes

Updates tailscale/tailscale#13406

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2 months ago
Irbe Krumina 096b090caf
cmd/containerboot,kube,util/linuxfw: configure kube egress proxies to route to 1+ tailnet targets (#13531)
* cmd/containerboot,kube,util/linuxfw: configure kube egress proxies to route to 1+ tailnet targets

This commit is first part of the work to allow running multiple
replicas of the Kubernetes operator egress proxies per tailnet service +
to allow exposing multiple tailnet services via each proxy replica.

This expands the existing iptables/nftables-based proxy configuration
mechanism.

A proxy can now be configured to route to one or more tailnet targets
via a (mounted) config file that, for each tailnet target, specifies:
- the target's tailnet IP or FQDN
- mappings of container ports to which cluster workloads will send traffic to
tailnet target ports where the traffic should be forwarded.

Example configfile contents:
{
  "some-svc": {"tailnetTarget":{"fqdn":"foo.tailnetxyz.ts.net","ports"{"tcp:4006:80":{"protocol":"tcp","matchPort":4006,"targetPort":80},"tcp:4007:443":{"protocol":"tcp","matchPort":4007,"targetPort":443}}}}
}

A proxy that is configured with this config file will configure firewall rules
to route cluster traffic to the tailnet targets. It will then watch the config file
for updates as well as monitor relevant netmap updates and reconfigure firewall
as needed.

This adds a bunch of new iptables/nftables functionality to make it easier to dynamically update
the firewall rules without needing to restart the proxy Pod as well as to make
it easier to debug/understand the rules:

- for iptables, each portmapping is a DNAT rule with a comment pointing
at the 'service',i.e:

-A PREROUTING ! -i tailscale0 -p tcp -m tcp --dport 4006 -m comment --comment "some-svc:tcp:4006 -> tcp:80" -j DNAT --to-destination 100.64.1.18:80
Additionally there is a SNAT rule for each tailnet target, to mask the source address.

- for nftables, a separate prerouting chain is created for each tailnet target
and all the portmapping rules are placed in that chain. This makes it easier
to look up rules and delete services when no longer needed.
(nftables allows hooking a custom chain to a prerouting hook, so no extra work
is needed to ensure that the rules in the service chains are evaluated).

The next steps will be to get the Kubernetes Operator to generate
the configfile and ensure it is mounted to the relevant proxy nodes.

Updates tailscale/tailscale#13406

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2 months ago
Maisem Ali a917718353 util/linuxfw: return nil interface not concrete type
It was returning a nil `*iptablesRunner` instead of a
nil `NetfilterRunner` interface which would then fail
checks later.

Fixes #13012

Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 months ago
Irbe Krumina 24a40f54d9
util/linuxfw: verify that IPv6 if available if (#12598)
nftable runner for an IPv6 address gets requested.

Updates tailscale/tailscale#12215

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
5 months ago
Irbe Krumina 7ef2f72135
util/linuxfw: fix IPv6 availability check for nftables (#12009)
* 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>
7 months ago
Andrew Dunham 25e32cc3ae util/linuxfw: fix table name in DelStatefulRule
Updates #12061
Follow-up to #12072

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I2ba8c4bff14d93816760ff5eaa1a16f17bad13c1
7 months ago
Anton Tolchanov ac638f32c0 util/linuxfw: fix stateful packet filtering in nftables mode
To match iptables:
b5dbf155b1/util/linuxfw/iptables_runner.go (L536)

Updates #12066

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
7 months ago
Andrew Lytvynov c28f5767bf
various: implement stateful firewalling on Linux (#12025)
Updates https://github.com/tailscale/corp/issues/19623


Change-Id: I7980e1fb736e234e66fa000d488066466c96ec85

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
7 months ago
Irbe Krumina 3af0f526b8
cmd{containerboot,k8s-operator},util/linuxfw: support ExternalName Services (#11802)
* 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>
7 months ago
Irbe Krumina 1fbaf26106
util/linuxfw: fix chain comparison (#11639)
Don't compare pointer fields by pointer value, but by the actual value

Updates#cleanup

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
8 months ago
Irbe Krumina 92ca770b8d
util/linuxfw: fix MSS clamping in nftables mode (#11588)
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>
8 months ago
Irbe Krumina 5fb721d4ad
util/linuxfw,wgengine/router: skip IPv6 firewall configuration in partial iptables mode (#11546)
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>
8 months ago
James Tucker 3f7313dbdb util/linuxfw,wgengine/router: enable IPv6 configuration when netfilter is disabled
Updates #11434

Signed-off-by: James Tucker <james@tailscale.com>
8 months ago
Irbe Krumina 90c4067010
util/linuxfw: add container-friendly IPv6 NAT check (#11353)
Remove IPv6 NAT check when routing is being set up
using nftables.
This is unnecessary as support for nftables was
added after support for IPv6.
https://tldp.org/HOWTO/Linux+IPv6-HOWTO/ch18s04.html
https://wiki.nftables.org/wiki-nftables/index.php/Building_and_installing_nftables_from_sources

Additionally, run an extra check for IPv6 NAT support
when the routing is set up with iptables.
This is because the earlier checks rely on
being able to use modprobe and on /proc/net/ip6_tables_names
being populated on start - these conditions are usually not
true in container environments.

Updates tailscale/tailscale#11344

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
9 months ago
Irbe Krumina 097c5ed927
util/linuxfw: insert rather than append nftables DNAT rule (#11303)
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>
9 months ago
James Tucker 0b16620b80 .github/workflows: add privileged tests workflow
We had missed regressions from privileged tests not running, now they
can run.

Updates #cleanup
Signed-off-by: James Tucker <james@tailscale.com>
10 months ago
Irbe Krumina 0cdc8e20d6
util/linuxfw: return created chain (#10563)
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>
12 months ago
Naman Sood d46a4eced5
util/linuxfw, wgengine: allow ingress to magicsock UDP port on Linux (#10370)
* 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>
12 months ago
Naman Sood 0a59754eda linuxfw,wgengine/route,ipn: add c2n and nodeattrs to control linux netfilter
Updates tailscale/corp#14029.

Signed-off-by: Naman Sood <mail@nsood.in>
12 months ago
Maisem Ali c3a8e63100 util/linuxfw: add additional nftable detection logic
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>
1 year ago
Maisem Ali fbfee6a8c0 cmd/containerboot: use linuxfw.NetfilterRunner
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>
1 year ago
Maisem Ali 05a1f5bf71 util/linuxfw: move detection logic
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>
1 year ago
James Tucker ba6ec42f6d util/linuxfw: add missing input rule to the tailscale tun
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 #391
Fixes #7332
Updates #9084

Signed-off-by: James Tucker <james@tailscale.com>
1 year ago
James Tucker 2066f9fbb2 util/linuxfw: fix crash in DelSNATRule when no rules are found
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>
1 year ago
Craig Rodrigues 8683ce78c2 client/web, clientupdate, util/linuxfw, wgengine/magicsock: Use %v verb for errors
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>
1 year ago
Brad Fitzpatrick 1b223566dd util/linuxfw: fix typo in unexported doc comment
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>
1 year ago
KevinLiang10 b040094b90 util/linuxfw: reorganize nftables rules to allow it to work with ufw
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>
1 year ago
KevinLiang10 a3c7b21cd1 util/linuxfw: add nftables support
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>
1 year ago