Attempt to load the xt_mark kernel module when it is not present. If the
load fails, log error information.
It may be tempting to promote this failure to an error once it has been
in use for some time, so as to avoid reaching an error with the iptables
invocation, however, there are conditions under which the two stages may
disagree - this change adds more useful breadcrumbs.
Example new output from tailscaled running under my WSL2:
```
router: ensure module xt_mark: "/usr/sbin/modprobe xt_mark" failed: exit status 1; modprobe: FATAL: Module xt_mark not found in directory /lib/modules/5.10.43.3-microsoft-standard-WSL2
```
Background:
There are two places to lookup modules, one is `/proc/modules` "old",
the other is `/sys/module/` "new".
There was query_modules(2) in linux <2.6, alas, it is gone.
In a docker container in the default configuration, you would get
/proc/modules and /sys/module/ both populated. lsmod may work file,
modprobe will fail with EPERM at `finit_module()` for an unpriviliged
container.
In a priviliged container the load may *succeed*, if some conditions are
met. This condition should be avoided, but the code landing in this
change does not attempt to avoid this scenario as it is both difficult
to detect, and has a very uncertain impact.
In an nspawn container `/proc/modules` is populated, but `/sys/module`
does not exist. Modern `lsmod` versions will fail to gather most module
information, without sysfs being populated with module information.
In WSL2 modules are likely missing, as the in-use kernel typically is
not provided by the distribution filesystem, and WSL does not mount in a
module filesystem of its own. Notably the WSL2 kernel supports iptables
marks without listing the xt_mark module in /sys/module, and
/proc/modules is empty.
On a recent kernel, we can ask the capabilities system about SYS_MODULE,
that will help to disambiguate between the non-privileged container case
and just being root. On older kernels these calls may fail.
Update #4329
Signed-off-by: James Tucker <james@tailscale.com>
For tests.
Now that we can always listen (whereas we used to fail prior to
a2c330c496), some goroutine leak
checks were failing in tests in another repo after that change.
Change-Id: Id95a4b71167eca61962a48616d79741b9991e0bc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The primary distribution for LinuxMint is based on Ubuntu,
but there is an alternate Debian-based distribution called
LMDE. Both variations identify themselves as "linuxmint"
We added UBUNTU_VERSION to the Ubuntu handling for linuxmint,
the only distribution so far found to do this. Instead, split
linuxmint out into its own case and use either UBUNTU_VERSION
or DEBIAN_VERSION, whichever is present.
Tested on an LMDE 5 (elsie) VM.
Updates https://github.com/tailscale/tailscale/issues/2915
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
$ tailscale debug via 0xb 10.2.0.0/16
fd7a:115c:a1e0:b1a:0🅱️a02:0/112
$ tailscale debug via fd7a:115c:a1e0:b1a:0🅱️a02:0/112
site 11 (0xb), 10.2.0.0/16
Previously: 3ae701f0eb
This adds a little debug tool to do CIDR math to make converting between
those ranges easier for now.
Updates #3616
Change-Id: I98302e95d17765bfaced3ecbb71cbd43e84bff46
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The previous commit (1b89662eff) this for Android, but we can also use
this on any platform if we we would otherwise fail.
Change-Id: I4cd78b40e9e77fca5cc8e717dd48ac173101bed4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It unfortuantely gets truncated because it's too long, split it into 3
different log lines to circumvent truncation.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Currently we ignore these interfaces in the darwin osMon but then would consider it
interesting when checking if anything had changed.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
We intercept the peerapi port in netstack anyway, so there's no reason
the linux kernel on Android needs to know about it. It's only getting
in the way and causing problems for reasons we don't fully understand.
But we don't even need to understand it because it's not relevant
anymore.
Instead, provide a dummy net.Listener that just sits and blocks to
pacify the rest of the code that assumes it can be stuck in a
Listener.Accept call and call Listener.Close and Listener.Addr.
We'll likely do this for all platforms in the future, if/when we also
link in netstack on iOS.
Updates #4449
Updates #4293
Updates #3986
Change-Id: Ic2d3fe2f3cee60fc527356a3368830f17aeb75ae
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit changes proxy-to-grafana to report errors while polling for
tailscaled status instead of terminating at the first sign of an error.
This allows tailscale some time to come up before the proxy decides to
give up.
Signed-off-by: Blake Mizerany <blake.mizerany@gmail.com>
In cases where tailscale is operating behind a MITM proxy, we need to consider
that a lot more of the internals of our HTTP requests are visible and may be
used as part of authorization checks. As such, we need to 'behave' as closely
as possible to ideal.
- Some proxies do authorization or consistency checks based the on Host header
or HTTP URI, instead of just the IP/hostname/SNI. As such, we need to
construct a `*http.Request` with a valid URI everytime HTTP is going to be
used on the wire, even if its over TLS.
Aside from the singular instance in net/netcheck, I couldn't find anywhere
else a http.Request was constructed incorrectly.
- Some proxies may deny requests, typically by returning a 403 status code. We
should not consider these requests as a valid latency check, so netcheck
semantics have been updated to consider >299 status codes as a failed probe.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Two changes in one:
* make DoH upgrades an explicitly scheduled send earlier, when we come
up with the resolvers-and-delay send plan. Previously we were
getting e.g. four Google DNS IPs and then spreading them out in
time (for back when we only did UDP) but then later we added DoH
upgrading at the UDP packet layer, which resulted in sometimes
multiple DoH queries to the same provider running (each doing happy
eyeballs dialing to 4x IPs themselves) for each of the 4 source IPs.
Instead, take those 4 Google/Cloudflare IPs and schedule 5 things:
first the DoH query (which can use all 4 IPs), and then each of the
4 IPs as UDP later.
* clean up the dnstype.Resolver.Addr confusion; half the code was
using it as an IP string (as documented) as half was using it as
an IP:port (from some prior type we used), primarily for tests.
Instead, document it was being primarily an IP string but also
accepting an IP:port for tests, then add an accessor method on it
to get the IPPort and use that consistently everywhere.
Change-Id: Ifdd72b9e45433a5b9c029194d50db2b9f9217b53
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If all N queries failed, we waited until context timeout (in 5
seconds) to return.
This makes (*forwarder).forward fail fast when the network's
unavailable.
Change-Id: Ibbb3efea7ed34acd3f3b29b5fee00ba8c7492569
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Currently if the policy changes and the session is logged in with local
user "u1" and the new policy says they can only login with "u2" now, the
user doesn't get kicked out because they had requested
`rando@<ssh-host>` and the defaulting had made that go to `u1`.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
From the machines tab its hard to differenciate desktop Linux installs from
server Linux installs. Transmitting this information should make this
determination a lot easier.
Due to the reality that tailscaled is likely a system process, the standard
checks based on XDG_SESSION_TYPE or DISPLAY environment variables are not
possible (those variables won't be set). Instead, we look for listening
unix sockets that are typical of desktop installs.
Signed-off-by: Tom DNetto <tom@tailscale.com>
For people running self-hosted control planes who want a global
opt-out knob instead of running their own logcatcher.
Change-Id: I7f996c09f45850ff77b58bfd5a535e197971725a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Simplify the ability to reason about the DoH dialing code by reusing the
dnscache's dialer we already have.
Also, reduce the scope of the "ip" variable we don't want to close over.
This necessarily adds a new field to dnscache.Resolver:
SingleHostStaticResult, for when the caller already knows the IPs to be
returned.
Change-Id: I9f2aef7926f649137a5a3e63eebad6a3fffa48c0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The default is still users can debug their own nodes. But like
cd916b728b did, this adds support for admins to grant additional
capabilities with the new tailcfg.CapabilityDebugPeer cap.
Updates #4217
Change-Id: Ifce3d9a1f8e8845797970a4f97b393194663d35f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fail on unsupported platforms (must be Linux or macOS tailscaled with
WIP env) or when disabled by admin (with TS_DISABLE_SSH_SERVER=1)
Updates #3802
Change-Id: I5ba191ed0d8ba4ddabe9b8fc1c6a0ead8754b286
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In `(*Mon).Start` we don't run a timer to update `(*Mon).lastWall` on iOS and
Android as their sleep patterns are bespoke. However, in the debounce
goroutine we would notice that the the wall clock hadn't been updated
since the last event would assume that a time jump had occurred. This would
result in non-events being considered as major-change events.
This commit makes it so that `(*Mon).timeJumped` is never set to `true`
on iOS and Android.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
And rename to updateFilterLocked to prevent future mistakes.
Fixes#4427
Change-Id: I4d37b90027d5ff872a339ce8180f5723704848dc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Controlled by server-sent capability policy.
To be initially used for SSH servers to record sessions to other
nodes. Not yet productized into something user-accessible. (Notably,
the list of Taildrop targets from the sender side isn't augmented
yet.) This purely permits expanding the set of expands a node will
accept a drop from.
Updates #3802
Updates #4217
Change-Id: Id7a5bccd686490f8ef2cdc7dae7c07c440dc0085
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
tailcfg.PingResponse formalizes the TSMP & disco response message, and
controlclient is wired to send POST responses containing
tailcfg.PingResponse for TSMP and disco PingRequests.
Updates tailscale/corp#754
Signed-off-by: James Tucker <james@tailscale.com>
We only use the termios subpackage, so we're unaffected by
CVE-2020-7665, but the bump will let dependabot return to slumber.
Fixes https://github.com/tailscale/tailscale/security/dependabot/2
Signed-off-by: James Tucker <james@tailscale.com>
Remove the weird netstack -> tailssh dependency and instead have tailssh
register itself with ipnlocal when linked.
This makes tailssh.server a singleton, so we can have a global map of
all sessions.
Updates #3802
Change-Id: Iad5caec3a26a33011796878ab66b8e7b49339f29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
