Commit Graph

4147 Commits (aa37aece9c007de64042ba2f882b4f0c703b2c1b)
 

Author SHA1 Message Date
David Anderson a364bf2b62 ssh/tailssh: various typo fixes, clarifications.
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Brad Fitzpatrick c994eba763 ssh/tailssh: simplify matchRule with Reject rules
Updates #3802

Change-Id: I59fe111eef5ac8abbcbcec922e293712a65a4830
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 31094d557b ssh/tailssh: chmod the auth socket to be only user accessible
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 337c77964b ssh/tailssh: set groups and gid in the incubated process
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 8ac4d52b59 ssh/tailssh: filter accepted environment variables
Noted by @danderson

Updates #3802

Change-Id: Iac70717ed57f11726209ac1ea93ddc6696605f94
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 89832c1a95 tailcfg: fix typo in SessionDuration field name
Noted by @danderson.

Updates #3802

Change-Id: Ide15f3f28e30f6abb5c94d7dcd218bd9482752a0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 695f8a1d7e ssh/tailssh: add support for sftp
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 53588f632d Revert "wgengine/router,util/kmod: load & log xt_mark"
This reverts commit 8d6793fd70.

Reason: breaks Android build (cgo/pthreads addition)

We can try again next cycle.

Change-Id: I5e7e1730a8bf399a8acfce546a6d22e11fb835d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom DNetto df26c63793 net/dns/resolver, net/tsaddr: fix reverse lookups in 4to6 IP range
Fixes #4439

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
James Tucker 8d6793fd70 wgengine/router,util/kmod: load & log xt_mark
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>
3 years ago
Brad Fitzpatrick f7cb6630e7 tailcfg: document SSHPrincipal.PubKeys URL expansions
From f74ee80abe which lacked docs.

Updates #3802

Change-Id: Ia7df05a486ae383cc6d9aca9dfe487b04e243ad5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 5b4154342e ssh/tailssh: fix double SSH-2.0- prefix in greeting banner
gliderlabs/ssh was already adding the "SSH-2.0-" prefix.

Updates #3802

Change-Id: I19a1cd9308371a2898e7883cf26e94c9b54bab29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 7a097ccc83 ipn/ipnlocal: close peerapi listeners on LocalBackend.Shutdown
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>
3 years ago
Maisem Ali 2b8b887d55 ssh/tailssh: send banner messages during auth, move more to conn
(VSCode Live Share between Brad & Maisem!)

Updates #3802

Change-Id: Id8edca4481b0811debfdf56d4ccb1a46f71dd6d3
Co-Authored-By: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Denton Gentry 13f75b9667 scripts/install: add Alma Linux.
Tested using an Alma Linux 8.5 VM.
Updates https://github.com/tailscale/tailscale/issues/2915

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Denton Gentry c2b907c965 scripts/installer: support LinuxMint Debian.
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>
3 years ago
Denton Gentry 61868f281e scripts/installer: call emerge with --ask=n
Fixes https://github.com/tailscale/tailscale/issues/4354

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Denton Gentry db7da6622a scripts/installer: add ParrotOS support
Support ParrotSec https://parrotsec.org/
Tested using a Parrot 5.0 VM.

Updates https://github.com/tailscale/tailscale/issues/2915

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Brad Fitzpatrick d413850bd7 cmd/tailscale: add "debug via" subcommand to do CIDR math for via ranges
$ 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>
3 years ago
Brad Fitzpatrick f74ee80abe ssh/tailssh: support expansions in public key fetch URL too
Updates #3802

Change-Id: I5aa98bdab14fd1c1c00ba63b93f8d7e670f72437
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 14d077fc3a ssh/tailssh: terminate ssh auth early if no policy can match
Also bump github.com/tailscale/golang-x-crypto/ssh

Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick a2c330c496 ipn/ipnlocal: use the fake peerapi listener as fallback if netstack available
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>
3 years ago
Maisem Ali 136f30fc92 wgengine/monitor: split the unexpected stringification log line
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>
3 years ago
Maisem Ali 8e40bfc6ea wgengine/monitor: ignore OS-specific uninteresting interfaces
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>
3 years ago
Brad Fitzpatrick 1b89662eff ipn/ipnlocal: make peerapi listener on Android avoid the kernel
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>
3 years ago
Brad Fitzpatrick cf9b9a7fec tstest/iosdeps: add test for forbidden iOS dependencies
Fixes #4463

Change-Id: I8305710e8a075263ae9a88a29624b19032d5beeb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8b81254992 ipn/ipnlocal: reject tailscale up --ssh if disabled on tailnet
Updates #3802

Change-Id: I3f1e839391fe9b28270f506f4bb8d8e3d36716f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 0ce67ccda6 wgengine/router: make supportsV6NAT check catch more cases
Updates #4459

Change-Id: Ic27621569d2739298e652769d10e38608c6012be
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Xe Iaso fc2f628d4c
cmd/nginx-auth: maintainer scripts and tailnet checking (#4460)
* cmd/nginx-auth: add maintainer scripts

Signed-off-by: Xe <xe@tailscale.com>

* cmd/nginx-auth: add Expected-Tailnet header and documentation

Signed-off-by: Xe <xe@tailscale.com>
3 years ago
Blake Mizerany 33fa43252e cmd/proxy-to-grafana: prevent premature termination
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>
3 years ago
Tom DNetto c8f4dfc8c0 derp/derphttp,net/netcheck: improve netcheck behavior under MITM proxies
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>
3 years ago
Brad Fitzpatrick cc575fe4d6 net/dns: schedule DoH upgrade explicitly, fix Resolver.Addr confusion
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>
3 years ago
Brad Fitzpatrick e3a4952527 net/dns/resolver: count errors when racing DNS queries, fail earlier
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>
3 years ago
Brad Fitzpatrick d9efbd97cb net/dns: remove an unused function
Change-Id: I7c920c76223ffac37954ef2a18754afc52177598
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c13be0c509 tailcfg: clarify how SSHPolicy.Rules are evaluated between auth phases
Updates #3802

Change-Id: I321183a8a2b065a40dca8dd95ca90cd822a17ff8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 91a187bf87 ssh/tailssh: make checkStillValid also consider username changes
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>
3 years ago
Maisem Ali a04eebf59f ipn/ipnlocal: also use SSHPolicies when updating filterHash
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Joe Tsai d201d217df
go.toolchain.rev: update to go1.18.1 (#4438)
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
3 years ago
Tom DNetto 24cd26534f hostinfo, tailcfg: add desktop detection on Linux to hostinfo
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>
3 years ago
Brad Fitzpatrick 9f1dd716e8 tailcfg, logtail: provide Debug bit to disable logtail
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>
3 years ago
Brad Fitzpatrick ecea6cb994 net/dns/resolver: make DoH dialer use existing dnscache happy eyeball dialer
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>
3 years ago
Brad Fitzpatrick e96dd00652 ipn/ipnlocal: add capability for debugging peers over peerapi
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>
3 years ago
Maisem Ali 945879fa38 cmd/tailscale: [ssh] enable StrictHostKeyChecking mode
Updates #3802

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 8f5e5bff1e cmd/tailscale, etc: make "tailscale up --ssh" fail fast when unavailable
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>
3 years ago
Brad Fitzpatrick f0e2272e04 cmd/tailscale: unhide 'up --ssh' behind WIP env var
Updates #3802

Change-Id: I99c550c2e4450640b0ee6ab060f178dde1360553
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 93221b4535 ssh/tailssh: cache public keys fetched from URLs
Updates #3802

Change-Id: I96715bae02bce6ea19f16b1736d1bbcd7bcf3534
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 3ffd88a84a wgengine/monitor: do not set timeJumped on iOS/Android
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>
3 years ago
Brad Fitzpatrick ade7bd8745 ssh/tailssh: close sessions on policy change if no longer allowed
Updates #3802

Change-Id: I98503c2505b77ac9d0cc792614fcdb691761a70c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 4ec83fbad6 ipn/ipnlocal: only call updateFilter with mutex held
And rename to updateFilterLocked to prevent future mistakes.

Fixes #4427

Change-Id: I4d37b90027d5ff872a339ce8180f5723704848dc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cd916b728b ipn/ipnlocal: add start of inter-user Taildrop
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>
3 years ago