Commit Graph

162 Commits

Author SHA1 Message Date
Brad Fitzpatrick
2d96215d97 wgengine/router: make Linux delRoute idempotent, cidrDiff fail late as possible
This makes cidrDiff do as much as possible before failing, and makes a
delete of an already-deleted rule be a no-op. We should never do this
ourselves, but other things on the system can, and this should help us
recover a bit.

Also adds the start of root-requiring tests.

TODO: hook into wgengine/monitor and notice when routes are changed
behind our back, and invalidate our routes map and re-read from
kernel (via the ip command) at least on the next reconfig call.

Updates tailscale/corp#1338

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-18 10:36:00 -08:00
Brad Fitzpatrick
96a488e37e wgengine/router: simplify func normalizeCIDR using netaddr method 2021-02-17 21:35:33 -08:00
Brad Fitzpatrick
88ab0173a7 wgengine/router: fix BSD router to support multiple local addrs, IPv6
Fixes #1201
2021-02-11 19:13:03 -08:00
Brad Fitzpatrick
1ec64bc94d wgengine/router: add another Windows firewall rule to allow incoming UDP
Based on @sailorfrag's research.

Fixes #1312

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-10 13:12:17 -08:00
Brad Fitzpatrick
d76334d2f0 ipn: split LocalBackend off into new ipn/ipnlocal package
And move a couple other types down into leafier packages.

Now cmd/tailscale doesn't bring in netlink, magicsock, wgengine, etc.

Fixes #1181

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-04 14:04:23 -08:00
Brad Fitzpatrick
a2aa6cd2ed wgengine/router: clarify disabled IPv6 message on Linux 2021-02-02 14:51:44 -08:00
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>
2021-02-01 16:12:17 -08:00
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>
2021-01-28 13:35:11 -08:00
Brad Fitzpatrick
4fea604979 wgengine/router: stop setPrivateNetwork goroutine on configureInterface failure
On Windows, configureInterface starts a goroutine reconfiguring the
Windows firewall.

But if configureInterface fails later, that goroutine kept running and
likely failing forever, spamming logs. Make it stop quietly if its
launching goroutine filed.
2021-01-25 13:22:51 -08:00
Alex Brainman
6e4231c03c wgengine/router/dns: remove unused code
Commit 68ddf1 removed code that reads
`SOFTWARE\Tailscale IPN\SearchList` registry value. But the commit
left code that writes that value.

So now this package writes and never reads the value.

Remove the code to stop pointless work.

Updates #853

Signed-off-by: Alex Brainman <alex.brainman@gmail.com>
2021-01-14 14:04:35 -08:00
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>
2020-12-29 08:26:17 -08:00
Josh Bleecher Snyder
2fe770ed72 all: replace wgcfg.IP and wgcfg.CIDR with netaddr types
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-28 13:00:42 -08:00
David Crawshaw
2b2a16d9a2 wgengine/router/dns: reduce windows registry key open timeout
The windows key timeout is longer than the wgengine watchdog timeout,
which means we never reach the timeout, instead the process exits.
Reduce the timeout so if we do hit it, at least the process continues.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2020-12-21 17:24:58 -05:00
David Crawshaw
b4f70d8232 wgengine/router/dns: use the correct interface GUID
On Win10, there's a hardcoded GUID and this works.
On Win7, this GUID changes and we need to ask the tun for its
LUID and convert that from the GUID.

This commit uses the computed GUID that is placed in InterfaceName.

Diagnosed by Jason Donnenfeld. (Thanks!)
2020-12-21 16:43:24 -05:00
Brad Fitzpatrick
15c064f76f wgengine/router/dns: remove unsafe endianness detection on Linux 2020-12-21 13:11:09 -08:00
Brad Fitzpatrick
f9659323df wgengine/router/dns: fix typo in comment 2020-12-21 13:07:30 -08:00
Brad Fitzpatrick
053a1d1340 all: annotate log verbosity levels on most egregiously spammy log prints
Fixes #924
Fixes #282

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-12-21 12:59:33 -08:00
Josh Bleecher Snyder
6db9c4a173 wgenginer/router/dns: use constant from golang.org/x/sys/windows
Made available in https://golang.org/cl/277153
2020-12-10 17:23:01 -08:00
Aleksandar Pesic
0dc295a640 Isolate WireGuard code into a separate file with appropriate copyright info in header.
Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
2020-12-11 01:08:41 +01:00
Aleksandar Pesic
d854fe95d2 Trivial change in function description.
Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
2020-12-11 00:55:37 +01:00
Aleksandar Pesic
338fd44657 Replace registry-access code, update wireguard-go and x/sys/windows.
Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
2020-12-11 00:37:24 +01:00
Aleksandar Pesic
274d32d0aa Prepare for the new wireguard-go API.
Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
2020-12-11 00:08:28 +01:00
Brad Fitzpatrick
fc8bc76e58 wgengine/router: lock goroutine to OS thread before using OLE [windows]
See https://github.com/tailscale/tailscale/issues/921#issuecomment-727526807

Not yet sure whether this is our problem, but it can't hurt at least,
and seems like what we're supposed to do.

Updates #921
2020-11-16 09:55:44 -08:00
David Anderson
a664aac877 wgengine/router: disable IPv6 if v6 policy routing is unavailable.
Fixes #895.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-11-11 15:31:15 -08:00
David Anderson
ebd96bf4a9 wgengine/router/dns: use OpenKeyWait to set DNS configuration.
Fixes tailscale/corp#839.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-11-09 14:08:39 -08:00
Brad Fitzpatrick
119101962c wgengine/router: don't double-prefix dns log messages [Windows] 2020-11-06 11:42:46 -08:00
Brad Fitzpatrick
28f6552646 wgengine/router/dns: run ipconfig /registerdns async, log timing
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-11-03 14:27:37 -08:00
Brad Fitzpatrick
01ee638cca Change some os.IsNotExist to errors.Is(err, os.ErrNotExist) for non-os errors.
os.IsNotExist doesn't unwrap errors. errors.Is does.

The ioutil.ReadFile ones happened to be fine but I changed them so
we're consistent with the rule: if the error comes from os, you can
use os.IsNotExist, but from any other package, use errors.Is.
(errors.Is always would also work, but not worth updating all the code)

The motivation here was that we were logging about failure to migrate
legacy relay node prefs file on startup, even though the code tried
to avoid that.

See golang/go#41122
2020-11-02 08:33:34 -08:00
David Anderson
68ddf134d7 wgengine/router/dns: issue ipconfig /registerdns when applying DNS settings.
Amazingly, there doesn't seem to be a documented way of updating network
configuration programmatically in a way that Windows takes notice of.
The naturopathic remedy for this is to invoke ipconfig /registerdns, which
does a variety of harmless things and also invokes the private API that
tells windows to notice new adapter settings. This makes our DNS config
changes stick within a few seconds of us setting them.

If we're invoking a shell command anyway, why futz with the registry at
all? Because netsh has no command for changing the DNS suffix list, and
its commands for setting resolvers requires parsing its output and
keeping track of which server is in what index. Amazingly, twiddling
the registry directly is the less painful option.

Fixes #853.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-10-29 20:05:38 -07:00
Brad Fitzpatrick
508f5c3ae0 wgengine/router: fix bug where getInterfaceRoutes always returned an empty list
Regression from f2ce64f0c6 (r43710860)

Fixes #870
2020-10-29 14:38:59 -07:00
Brad Fitzpatrick
38bde61b3d wgengine/router: make Windows firewall configuration async
Updating the Windows firewall is usually reasonably fast, but
sometimes blocks for 20 seconds, 4 minutes, etc. Not sure why.

Until we understand that's happening, configure it in the background
without blocking the normal control flow.

Updates #785

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-10-29 13:40:20 -07:00
David Anderson
ff0cf6340a wgengine/router: fix configuration of loopback netfilter rules for v6.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-10-15 15:15:24 -07:00
Alex Brainman
f2ce64f0c6 wgengine/router: unfork winipcfg-go package, use upstream
Use golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
instead of github.com/tailscale/winipcfg-go package.

Updates #760

Signed-off-by: Alex Brainman <alex.brainman@gmail.com>
2020-10-13 09:21:22 -07:00
David Anderson
c493e5804f wgengine/router: make v6-ness configurable in test, for consistent results.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-09-28 23:47:05 +00:00
Brad Fitzpatrick
c86761cfd1 Remove tuntap references. We only use TUN. 2020-09-25 13:13:13 -07:00
Brad Fitzpatrick
bbb56f2303 wgengine/router: fix tests on Debian Buster as regular user on machine with IPv6 2020-09-25 11:27:57 -07:00
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>
2020-09-24 18:37:00 -07:00
David Anderson
0d80904fc2 wgengine/router: set up basic IPv6 routing/firewalling.
Part of #19.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-09-24 18:37:00 -07:00
Brad Fitzpatrick
2d0ed99672 wgengine, wgengine/router: add a bunch of (temporary?) engine creation logging
Trying to debug what's slow on a user's machine.

Updates #785
2020-09-23 15:27:30 -07:00
Brad Fitzpatrick
7c11f71ac5 wgengine/router: ignore errors deleting 169.254.255.255/32 route on Windows
Updates #785
2020-09-23 14:01:00 -07:00
Brad Fitzpatrick
3528d28ed1 wgengine/router: move Tailscale's winipcfg additions into wgengine/router
Part of unforking our winipcfg-go and using upstream (#760), move our
additions into our repo. (We might upstream them later if upstream has
interest)

Originally these were:

@apenwarr: "Add ifc.SyncAddresses() and SyncRoutes()."
609dcf2df5

@bradfitz: "winipcfg: make Interface.AddRoutes do as much as possible, return combined error"
e9f93d53f3

@bradfitz: "prevent unnecessary Interface.SyncAddresses work; normalize IPNets in deltaNets"
decb9ee8e1
2020-09-22 09:24:10 -07:00
Brad Fitzpatrick
fd77268770 wgengine/router: enumerate all interfaces when finding Tailscale adapter by GUID
Might fix it. I've spent too much time failing to reproduce the issue. This doesn't
seem to make it worse, though (it still runs for me), so I'll include this and
see if it helps others while I still work on a reliable way to reproduce it.

Updates tailscale/corp#474
2020-09-21 14:52:52 -07:00
Brad Fitzpatrick
5bcac4eaac net/tshttpproxy: add GetProxyForURL negative cache
Otherwise when PAC server is down, we log, and each log entry is a new
HTTP request (from logtail) and a new GetProxyForURL call, which again
logs, non-stop. This is also nicer to the WinHTTP service.

Then also hook up link change notifications to the cache to reset it
if there's a chance the network might work sooner.
2020-09-21 14:05:28 -07:00
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
2020-09-17 16:40:22 -04:00
Brad Fitzpatrick
acafe9811f wgengine/router: run netsh advfirewall less, rename, document setFirewall 2020-09-16 14:42:37 -07:00
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>
2020-09-15 14:14:33 -04:00
Brad Fitzpatrick
7e9d1f7808 wgengine/router: tighten isMissingIPv6Err
So it doesn't false positive if misused.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-09-15 08:21:56 -07:00
David Anderson
8f5b52e571 net/netns: add windows support.
Also remove rebinding logic from the windows router. Magicsock will
instead rebind based on link change signals.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-09-14 16:28:49 -07:00
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>
2020-09-11 13:12:40 -07:00
Brad Fitzpatrick
31c13013ae wgengine/router: tolerate disabled IPv6 on Windows
Fixes #412
Updates #524 (maybe fixes?)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-09-11 12:50:35 -07:00
Josh Bleecher Snyder
37b40b035b wgengine/router/dns: appease staticcheck (again) 2020-09-11 11:02:57 -07:00
Josh Bleecher Snyder
a877dd575c wgengine/router/dns: remove unnecessary lint ignore line
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-09-09 12:27:52 -07:00
Brad Fitzpatrick
913c1bd04f wgengine/router: on Windows, add a firewall rule to allow Tailscale
Updates tailscale/tailscale#454
2020-09-08 13:24:02 -07:00
Brad Fitzpatrick
6d14678009 wgengine/router: remove unnecessary newlines in log.Printf formats 2020-09-01 13:27:42 -07:00
Brad Fitzpatrick
09d56f54a7
wgengine/router: fix Windows route sorting that caused de-dup to not work (#727)
Updates #725

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-09-01 13:24:58 -07:00
Dmytro Shynkevych
a903d6c2ed
tailcfg, tsdns: derive root domains from list of nodes (#708)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-08-24 17:27:21 -04:00
Brad Fitzpatrick
461db356b9 wgengine/router/dns: fix staticcheck error on Mac 2020-08-19 15:12:30 -07:00
Dmytro Shynkevych
a583e498b0
router/dns: set all domains on Windows (#672)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-08-19 14:16:57 -04:00
Mike Kramlich
6fa7a9a055 wgengine/router/router_userspace_bsd: on Mac the route program syntax expects delete not del -- this had caused router reconfig to fail in some cases. Fixes #673
Signed-off-by: Mike Kramlich <groglogic@gmail.com>
2020-08-12 13:22:19 -07:00
Dmytro Shynkevych
95a18f815c
router/dns: detect host endianness for NetworkManager.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-08-12 16:13:05 -04:00
Brad Fitzpatrick
c64a43a734 wgengine/router: set MTU on Windows to min(configured,possible)
Fixes tailscale/corp#542

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-08-07 12:16:12 -07:00
Josh Bleecher Snyder
2622e8e082 wgenginer/router: fix build
Rebasing github.com/tailscale/wireguard-go to upstream
wireguard-go changed the API.

This commit is analogous to
https://git.zx2c4.com/wireguard-windows/commit/?id=6823cc10ffe193c0cb1d61a5d1828d563d3d0e5f
2020-08-06 17:37:05 -07:00
Dmytro Shynkevych
28e52a0492
all: dns refactor, add Proxied and PerDomain flags from control (#615)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-31 16:27:09 -04:00
Dmytro Shynkevych
8c850947db
router: split off sandboxed path from router_darwin (#624)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-31 01:10:14 -04:00
Dmytro Shynkevych
2ce2b63239
router: stop iOS subprocess sandbox violations (#617)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-29 21:09:18 -04:00
Dmytro Shynkevych
154d1cde05
router: reload systemd-resolved after changing /etc/resolv.conf (#619)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-29 20:57:25 -04:00
Dmytro Shynkevych
c53ab3111d wgengine/router: support legacy resolvconf
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-23 15:01:46 -04:00
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>
2020-07-22 11:59:54 -07:00
David Anderson
972a42cb33 wgengine/router: fix router_test to match the new marks.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-22 01:31:49 +00:00
David Anderson
d60917c0f1 wgengine/router: switch packet marks to avoid conflict with Weave Net.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-22 01:24:46 +00:00
Dmytro Shynkevych
a3e7252ce6 wgengine/router: use better NetworkManager API
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-18 04:03:45 -04:00
Eduardo Kienetz
5df6be9d38 Use LittleEndian for correct byte order on DNS IPs
Nameserver IP 10.11.12.13 would otherwise get written to resolv.conf as 13.12.11.10, as was happening on my client.

Signed-off-by: Eduardo Kienetz <eduardo@kienetz.com>
2020-07-17 23:34:28 -07:00
Wendi Yu
c3736250a4
wgengine: fix macos staticcheck errors (#557)
Signed-off-by: Wendi <wendi.yu@yahoo.ca>
2020-07-14 17:28:02 -06:00
Dmytro Shynkevych
30bbbe9467
wgengine/router: dns: unify on *BSD, multimode on Linux, Magic DNS (#536)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-14 09:12:00 -04:00
Dmytro Shynkevych
61abab999e
cmd/tailscaled: graceful shutdown (#534)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-13 06:17:58 -04:00
Brad Fitzpatrick
742b8b44a8 net/tsaddr: new package to hold Tailscale-specific IPs/ranges
And update existing callers with (near) duplicated cases.
2020-07-06 22:33:29 -07:00
David Crawshaw
9258d64261 wgengine/router: do not call ifconfig up if SetRoutesFunc is set
The NetworkExtension brings up the interface itself and does not have
access to `ifconfig`, which the underlying BSD userspace router attempts
to use when Up is called.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2020-06-26 09:45:28 -07:00
Reinaldo de Souza
a8635784bc wgengine: add BSD userspace router to darwin
Darwin and FreeBSD are compatible enough to share the userspace router.

The OSX router delegates to the BSD userspace router unless `SetRoutesFunc` is set.
That preserves the mechanism that allows `ipn-go-bridge` to specify its own routing behavior.

Fixes #177

Signed-off-by: Reinaldo de Souza <github@rei.nal.do>
2020-06-24 09:42:20 -07:00
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>
2020-06-03 13:46:31 -07:00
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>
2020-06-02 20:52:06 -07:00
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>
2020-05-31 04:31:01 -04:00
Avery Pennarun
f0b6ba78e8 wgengine: don't pass nil router.Config objects.
These are hard for swift to decode in the iOS app.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2020-05-31 02:37:22 -04:00
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>
2020-05-29 15:16:58 -07:00
David Anderson
fff062b461 wgengine/router: make runner.go linux-only for now.
Otherwise, staticcheck complains that these functions are unused
and unexported on macOS.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-28 12:19:01 -07:00
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>
2020-05-28 07:15:06 -04:00
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>
2020-05-28 07:15:05 -04:00
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>
2020-05-28 07:15:05 -04:00
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>
2020-05-28 07:15:05 -04:00
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>
2020-05-28 07:07:39 -04:00
David Anderson
7fb33123d3 wgengine/router: warn about another variation of busybox's ip.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-15 20:48:25 +00:00
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>
2020-05-15 07:09:33 +00:00
David Anderson
3e27b3c33c wgengine/router: more comments.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-14 23:51:44 -07:00
David Anderson
0fe262f093 ipn: plumb NetfilterMode all the way out to the CLI.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-14 23:51:44 -07:00
David Anderson
c67c8913c3 wgengine/router: add a test for linux router state transitions.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-14 23:51:44 -07:00
David Anderson
292606a975 wgengine/router: support multiple levels of netfilter involvement.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-14 23:51:44 -07:00
Avery Pennarun
d53e8fc0da router_darwin_support: we can build this on every platform.
Our new build scripts try to build ipn-go-bridge on more than just
linux and darwin, so let's enable this file so it can be successful on
every platform.
2020-05-14 04:42:36 -04:00
David Anderson
9ccbcda612 wgengine/router: rename config.Settings to config.Config, make pointer.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-12 15:58:33 -07:00
David Anderson
cd01bcc395 wgengine/router: allow loopback traffic from our own IP(s).
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-11 16:57:35 -07:00
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>
2020-05-11 20:17:13 +00:00
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>
2020-05-10 17:12:17 -07:00