Commit Graph

97 Commits (280255acae604796a1113861f5a84e6fa2dc6121)

Author SHA1 Message Date
David Anderson 267531e4f8 wgengine/router: probe better for v6 policy routing support.
Previously we disabled v6 support if the disable_policy knob was
missing in /proc, but some kernels support policy routing without
exposing the toggle. So instead, treat disable_policy absence as a
"maybe", and make the direct `ip -6 rule` probing a bit more
elaborate to compensate.

Fixes #1241.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick c7fc4a06da wgengine/router: don't configure IPv6 on Linux when IPv6 is unavailable
Fixes #1214

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 0d94fe5f69
wgengine/router: disable IPv6 on Linux if ip rule -6 fails (#1074)
Updates #562
Fixes #973

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson a664aac877 wgengine/router: disable IPv6 if v6 policy routing is unavailable.
Fixes #895.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson ff0cf6340a wgengine/router: fix configuration of loopback netfilter rules for v6.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c493e5804f wgengine/router: make v6-ness configurable in test, for consistent results.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick bbb56f2303 wgengine/router: fix tests on Debian Buster as regular user on machine with IPv6 4 years ago
David Anderson fddbcb0c7b wgengine/router: support various degrees of broken IPv6.
Gracefully skips touching the v6 NAT table on systems that don't have
it, and doesn't configure IPv6 at all if IPv6 is globally disabled.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 0d80904fc2 wgengine/router: set up basic IPv6 routing/firewalling.
Part of #19.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Christina Wen f0e9dcdc0a
wgengine/router: restore /etc/resolv.conf after tailscale down is called
This change is to restore /etc/resolv.conf after tailscale down is called. This is done by setting the dns.Manager before errors occur. Error collection is also added.

Fixes #723
4 years ago
Christina Wen e862f90e34
wgengine/router/router_linux.go: fixed " route del failed" error (#756)
* wgengine/router/router_linux.go: Switched `cidrDiff("addr")` and `cidrDiff("route")` order

Signed-off-by: Christina Wen <christina@tailscale.com>

Co-authored-by: Christina Wen <christina@tailscale.com>
4 years ago
Brad Fitzpatrick a084c44afc wgengine, wgengine/router, cmd/tailscale: force netfilter mode off on Synology
For now. Get it working again so it's not stuck on 0.98.

Subnet relay can come later.

Updates #451

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Dmytro Shynkevych 28e52a0492
all: dns refactor, add Proxied and PerDomain flags from control (#615)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
David Anderson 189d86cce5 wgengine/router: don't use 88 or 8888 as table/rule numbers.
We originally picked those numbers somewhat at random, but with the idea
that 8 is a traditionally lucky number in Chinese culture. Unfortunately,
"88" is also neo-nazi shorthand language.

Use 52 instead, because those are the digits above the letters
"TS" (tailscale) on a qwerty keyboard, so we're unlikely to collide with
other users. 5, 2 and 52 are also pleasantly culturally meaningless.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d60917c0f1 wgengine/router: switch packet marks to avoid conflict with Weave Net.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Dmytro Shynkevych 30bbbe9467
wgengine/router: dns: unify on *BSD, multimode on Linux, Magic DNS (#536)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 742b8b44a8 net/tsaddr: new package to hold Tailscale-specific IPs/ranges
And update existing callers with (near) duplicated cases.
4 years ago
David Anderson 5a32f8e181 wgengine/router: also accept exit code 254 from `ip rule del`.
iproute2 3.16.0-2 from Debian Jessie (oldoldstable) doesn't return
exit code 2 when deleting a non-existent IP rule.

Fixes #434

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 08a38f21c9 wgengine/router: don't filter subnet routing in netfilter.
We have a filter in tailscaled itself now, which is more robust
against weird network topologies (such as the one Docker creates).

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
Avery Pennarun e7ae6a2e06 net/netns, wgengine/router: support Linux machines that don't have 'ip rule'.
We'll use SO_BINDTODEVICE instead of fancy policy routing. This has
some limitations: for example, we will route all traffic through the
interface that has the main "default" (0.0.0.0/0) route, so machines
that have multiple physical interfaces might have to go through DERP to
get to some peers. But machines with multiple physical interfaces are
very likely to have policy routing (ip rule) support anyway.

So far, the only OS I know of that needs this feature is ChromeOS
(crostini). Fixes #245.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
David Anderson 5114df415e net/netns: set the bypass socket mark on linux.
This allows tailscaled's own traffic to bypass Tailscale-managed routes,
so that things like tailscale-provided default routes don't break
tailscaled itself.

Progress on #144.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
Avery Pennarun f69003fd46 router_linux: work around terrible bugs in old iptables-compat versions.
Specifically, this sequence:
	iptables -N ts-forward
	iptables -A ts-forward -m mark --mark 0x10000 -j ACCEPT
	iptables -A FORWARD -j ts-forward
doesn't work on Debian-9-using-nftables, but this sequence:
	iptables -N ts-forward
	iptables -A FORWARD -j ts-forward
	iptables -A ts-forward -m mark --mark 0x10000 -j ACCEPT
does work.

I'm sure the reason why is totally fascinating, but it's an old version
of iptables and the bug doesn't seem to exist on modern nftables, so
let's refactor our code to add rules in the always-safe order and
pretend this never happened.

Fixes #401.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Avery Pennarun 9ff51909a3 router_linux: fix behaviour when switching --netfilter-mode.
On startup, and when switching into =off and =nodivert, we were
deleting netfilter rules even if we weren't the ones that added them.

In order to avoid interfering with rules added by the sysadmin, we have
to be sure to delete rules only in the case that we added them in the
first place.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Avery Pennarun a496cdc943 router_linux: remove need for iptables.ListChains().
Instead of retrieving the list of chains, or the list of rules in a
chain, just try deleting the ones we don't want and then adding the
ones we do want. An error in flushing/deleting still means the rule
doesn't exist anymore, so there was no need to check for it first.

This avoids the need to parse iptables output, which avoids the need to
ever call iptables -S, which fixes #403, among other things. It's also
much more future proof in case the iptables command line changes.

Unfortunately the iptables go module doesn't properly pass the iptables
command exit code back up when doing .Delete(), so we can't correctly
check the exit code there. (exit code 1 really means the rule didn't
exist, rather than some other weird problem).

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Avery Pennarun 8a6bd21baf router_linux: extract process runner routines into runner.go.
These will probably be useful across platforms. They're not really
Linux-specific at all.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Avery Pennarun 34c30eaea0 router_linux: use only baseline 'ip rule' features that exist in old kernels.
This removes the use of suppress_ifgroup and fwmark "x/y" notation,
which are, among other things, not available in busybox and centos6.

We also use the return codes from the 'ip' program instead of trying to
parse its output.

I also had to remove the previous hack that routed all of 100.64.0.0/10
by default, because that would add the /10 route into the 'main' route
table instead of the new table 88, which is no good. It was a terrible
hack anyway; if we wanted to capture that route, we should have
captured it explicitly as a subnet route, not as part of the addr. Note
however that this change affects all platforms, so hopefully there
won't be any surprises elsewhere.

Fixes #405
Updates #320, #144

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
David Anderson 7fb33123d3 wgengine/router: warn about another variation of busybox's `ip`.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 9c914dc7dd wgengine/router: stop using -m comment.
The comment module is compiled out on several embedded systems (and
also gentoo, because netfilter can't go brrrr with comments holding it
back). Attempting to use comments results in a confusing error, and a
non-functional firewall.

Additionally, make the legacy rule cleanup non-fatal, because we *do*
have to probe for the existence of these -m comment rules, and doing
so will error out on these systems.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 3e27b3c33c wgengine/router: more comments.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 0fe262f093 ipn: plumb NetfilterMode all the way out to the CLI.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson c67c8913c3 wgengine/router: add a test for linux router state transitions.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 292606a975 wgengine/router: support multiple levels of netfilter involvement.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 9ccbcda612 wgengine/router: rename config.Settings to config.Config, make pointer.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson cd01bcc395 wgengine/router: allow loopback traffic from our own IP(s).
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson bfdc8175b1 wgengine/router: add a setting to disable SNAT for subnet routes.
Part of #320.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 21ac65d3da wgengine/router: explicitly detect and complain about busybox's `ip`.
Defensive programming against #368 in environments other than Docker,
e.g. if you try using Tailscale in Alpine Linux directly, sans
container.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 381b94d4d1 wgengine/router: include command output if `ip rule list` fails.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson efc1feedc9 wgengine/router: include more information when iptables ops fail.
The iptables package we use doesn't include command output, so we're
left with guessing what went wrong most of the time. This will at
least narrow things down to which operation failed.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson b01db109f5 wgengine/router: use inet.af/netaddr, not wgcfg.CIDR.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson b8f01eed34 wgengine/router: remove wireguard-go config from settings.
Instead, pass in only exactly the relevant configuration pieces
that the OS network stack cares about.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 8861bb5a19 wgengine/router: alter API to support multiple addrs, and use on linux.
FreeBSD and OpenBSD will error out with a complaint if we pass >1 address
right now, but we don't yet so that's okay.
5 years ago
David Anderson 6802481bf5 wgengine/router: don't use gateway routes on linux. 5 years ago
David Anderson 78b1ed39ea wgengine/router: add more documentation. 5 years ago
David Anderson c9de43cd59 wgengine/router: fix typo.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 89198b1691 wgengine/router: rewrite netfilter and routing logic.
New logic installs precise filters for subnet routes,
plays nice with other users of netfilter, and lays the
groundwork for fixing routing loops via policy routing.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 7618d7e677 wgengine/router: simplify some cmd invocations.
Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
David Anderson 1ac570def7 wgengine/router: split out from wgengine.
The router implementations are logically separate, with their own API.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago