Commit Graph

50 Commits (d837e0252f0ce9bd0a153c0911688e7e13a08a32)

Author SHA1 Message Date
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
Brad Fitzpatrick cec779e771 util/slicesx: add FirstElementEqual and LastElementEqual
And update a few callers as examples of motivation. (there are a
couple others, but these are the ones where it's prettier)

Updates #cleanup

Change-Id: Ic8c5cb7af0a59c6e790a599136b591ebe16d38eb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Maisem Ali 4d6a8224d5 util/linuxfw: fall back to nftables when iptables not found
When the desired netfilter mode was unset, we would always try
to use the `iptables` binary. In such cases if iptables was not found,
tailscaled would just crash as seen in #13440. To work around this, in those
cases check if the `iptables` binary even exists and if it doesn't fall back
to the nftables implementation.

Verified that it works on stock Ubuntu 24.04.

Updates #5621
Updates #8555
Updates #8762
Fixes #13440

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 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
Brad Fitzpatrick c6af5bbfe8 all: add test for package comments, fix, add comments as needed
Updates #cleanup

Change-Id: Ic4304e909d2131a95a38b26911f49e7b1729aaef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Tom Proctor 01a7726cf7
cmd/containerboot,cmd/k8s-operator: enable IPv6 for fqdn egress proxies (#12577)
cmd/containerboot,cmd/k8s-operator: enable IPv6 for fqdn egress proxies

Don't skip installing egress forwarding rules for IPv6 (as long as the host
supports IPv6), and set headless services `ipFamilyPolicy` to
`PreferDualStack` to optionally enable both IP families when possible. Note
that even with `PreferDualStack` set, testing a dual-stack GKE cluster with
the default DNS setup of kube-dns did not correctly set both A and
AAAA records for the headless service, and instead only did so when
switching the cluster DNS to Cloud DNS. For both IPv4 and IPv6 to work
simultaneously in a dual-stack cluster, we require headless services to
return both A and AAAA records.

If the host doesn't support IPv6 but the FQDN specified only has IPv6
addresses available, containerboot will exit with error code 1 and an
error message because there is no viable egress route.

Fixes #12215

Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>
5 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
Brad Fitzpatrick 909a292a8d util/linuxfw: don't try cleaning iptables on gokrazy
It just generates log spam.

Updates #12277

Change-Id: I5f65c0859e86de0a5349f9d26c9805e7c26b9371
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 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 add62af7c6
util/linuxfw,go.{mod,sum}: don't log errors when deleting non-existant chains and rules (#11852)
This PR bumps iptables to a newer version that has a function to detect
'NotExists' errors and uses that function to determine whether errors
received on iptables rule and chain clean up are because the rule/chain
does not exist- if so don't log the error.

Updates corp#19336

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
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
James Tucker db760d0bac cmd/tailscaled: move cleanup to an implicit action during startup
This removes a potentially increased boot delay for certain boot
topologies where they block on ExecStartPre that may have socket
activation dependencies on other system services (such as
systemd-resolved and NetworkManager).

Also rename cleanup to clean up in affected/immediately nearby places
per code review commentary.

Fixes #11599

Signed-off-by: James Tucker <james@tailscale.com>
8 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
James Tucker 055117ad45
util/linuxfw: fix support for containers without IPv6 iptables filters (#11381)
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>
9 months ago
James Tucker 43fba6e04d
util/linuxfw: correct logical error in NAT table check (#11380)
Updates #11344
Updates #11354

Signed-off-by: James Tucker <james@tailscale.com>
9 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
Brad Fitzpatrick 2bd3c1474b util/cmpx: delete now that we're using Go 1.22
Updates #11058

Change-Id: I09dea8e86f03ec148b715efca339eab8b1f0f644
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
10 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
Andrew Lytvynov 2716250ee8
all: cleanup unused code, part 2 (#10670)
And enable U1000 check in staticcheck.

Updates #cleanup

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
11 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 62d580f0e8 util/linuxfw: add missing error checks in tests
This would surface as panics when run on Fly. Still fail, but at least don't panic.

Updates #10003

Signed-off-by: Maisem Ali <maisem@tailscale.com>
1 year 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 b47cf04624 util/linuxfw: fix broken tests
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>
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 aad3584319 util/linuxfw: move fake runner into pkg
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>
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 8452d273e3 util/linuxfw: Fix comment which lists supported linux arches
Only arm64 and amd64 are supported

Signed-off-by: Craig Rodrigues <rodrigc@crodrigues.org>
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
Brad Fitzpatrick 7a5263e6d0 util/linuxfw: rename ErrorFWModeNotSupported
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>
1 year ago
KevinLiang10 ae63c51ff1 wgengine/router: add auto selection heuristic for iptables/nftables
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>
1 year ago
Brad Fitzpatrick 88cc0ad9f7 util/linuxfw: remove yet-unused code to fix linux/arm64 crash
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>
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
KevinLiang10 6ebd87c669 util/linuxfw: add new arch build constraints
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>
1 year ago
KevinLiang10 243ce6ccc1 util/linuxfw: decoupling IPTables logic from linux router
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>
1 year ago
Brad Fitzpatrick eefee6f149 all: use cmpx.Or where it made sense
I left a few out where writing it explicitly was better
for various reasons.

Updates #8296

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
1 year ago
Andrew Dunham 6927a844b1 util/linuxfw: add build constraints excluding GOARCH=arm
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>
2 years ago
Andrew Dunham ba48ec5e39 util/linuxfw: initial implementation of package
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
2 years ago