Commit Graph

1102 Commits (2336c73d4d527558d55aeefe6cf48c7063072def)

Author SHA1 Message Date
James Tucker 1aa75b1c9e wgengine/netstack: always set TCP keepalive
Setting keepalive ensures that idle connections will eventually be
closed. In userspace mode, any application configured TCP keepalive is
effectively swallowed by the host kernel, and is not easy to detect.
Failure to close connections when a peer tailscaled goes offline or
restarts may result in an otherwise indefinite connection for any
protocol endpoint that does not initiate new traffic.

This patch does not take any new opinion on a sensible default for the
keepalive timers, though as noted in the TODO, doing so likely deserves
further consideration.

Update #4522

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Maisem Ali 80ba161c40 wgengine/monitor: do not ignore changes to pdp_ip*
One current theory (among other things) on battery consumption is that
magicsock is resorting to using the IPv6 over LTE even on WiFi.
One thing that could explain this is that we do not get link change updates
for the LTE modem as we ignore them in this list.
This commit makes us not ignore changes to `pdp_ip` as a test.

Updates #3363

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 2265587d38 wgengine/{,magicsock}: add metrics for rebinds and restuns
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 910ae68e0b util/mak: move tailssh's mapSet into a new package for reuse elsewhere
Change-Id: Idfe95db82275fd2be6ca88f245830731a0d5aecf
Signed-off-by: Brad Fitzpatrick <bradfitz@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
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
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 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
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 16f3520089 all: add arbitrary capability support
Updates #4217

RELNOTE=start of WhoIsResponse capability support

Change-Id: I6522998a911fe49e2f003077dad6164c017eed9b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8ee044ea4a ssh/tailssh: make the SSH server a singleton, register with LocalBackend
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>
3 years ago
Brad Fitzpatrick da14e024a8 tailcfg, ssh/tailssh: optionally support SSH public keys in wire policy
And clean up logging.

Updates #3802

Change-Id: I756dc2d579a16757537142283d791f1d0319f4f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3ae701f0eb net/tsaddr, wgengine/netstack: add IPv6 range that forwards to site-relative IPv4
This defines a new magic IPv6 prefix, fd7a:115c:a1e0:b1a::/64, a
subset of our existing /48, where the final 32 bits are an IPv4
address, and the middle 32 bits are a user-chosen "site ID". (which
must currently be 0000:00xx; the top 3 bytes must be zero for now)

e.g., I can say my home LAN's "site ID" is "0000:00bb" and then
advertise its 10.2.0.0/16 IPv4 range via IPv6, like:

    tailscale up --advertise-routes=fd7a:115c:a1e0:b1a::bb:10.2.0.0/112

(112 being /128 minuse the /96 v6 prefix length)

Then people in my tailnet can:

     $ curl '[fd7a:115c:a1e0:b1a::bb:10.2.0.230]'
     <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ....

Updates #3616, etc

RELNOTE=initial support for TS IPv6 addresses to route v4 "via" specific nodes

Change-Id: I9b49b6ad10410a24b5866b9fbc69d3cae1f600ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
James Tucker f4aad61e67 wgengine/monitor: ignore duplicate RTM_NEWADDRs
Ignoring the events at this layer is the simpler path for right now, a
broader change should follow to suppress irrelevant change events in a
higher layer so as to avoid related problems with other monitoring paths
on other platforms.  This approach may also carry a small risk that it
applies an at-most-once invariant low in the chain that could be assumed
otherwise higher in the code.

I adjusted the newAddrMessage type to include interface index rather
than a label, as labels are not always supplied, and in particular on my
test hosts they were consistently missing for ipv6 address messages.

I adjusted the newAddrMessage.Addr field to be populated from
Attributes.Address rather than Attributes.Local, as again for ipv6
.Local was always empty, and with ipv4 the .Address and .Local contained
the same contents in each of my test environments.

Update #4282

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
James Tucker 2f69c383a5 wgengine/monitor: add envknob TS_DEBUG_NETLINK
While I trust the test behavior, I also want to assert the behavior in a
reproduction environment, this envknob gives me the log information I
need to do so.

Update #4282

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Tom 24bdcbe5c7
net/dns, net/dns/resolver, wgengine: refactor DNS request path (#4364)
* net/dns, net/dns/resolver, wgengine: refactor DNS request path

Previously, method calls into the DNS manager/resolver types handled DNS
requests rather than DNS packets. This is fine for UDP as one packet
corresponds to one request or response, however will not suit an
implementation that supports DNS over TCP.

To support PRs implementing this in the future, wgengine delegates
all handling/construction of packets to the magic DNS endpoint, to
the DNS types themselves. Handling IP packets at this level enables
future support for both UDP and TCP.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
James Tucker c6ac29bcc4
wgengine/netstack: disable refsvfs2 leak tracking (#4378)
In addition an envknob (TS_DEBUG_NETSTACK_LEAK_MODE) now provides access
to set leak tracking to more useful values.

Fixes #4309

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Brad Fitzpatrick e4d8d5e78b net/packet, wgengine/netstack: remove workaround for old gvisor ECN bug
Fixes #2642

Change-Id: Ic02251d24a4109679645d1c8336e0f961d0cce13
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 6fecc16c3b ipn/ipnlocal: do not process old status messages received out of order
When `setWgengineStatus` is invoked concurrently from multiple
goroutines, it is possible that the call invoked with a newer status is
processed before a call with an older status. e.g. a status that has
endpoints might be followed by a status without endpoints. This causes
unnecessary work in the engine and can result in packet loss.

This patch adds an `AsOf time.Time` field to the status to specifiy when the
status was calculated, which later allows `setWgengineStatus` to ignore
any status messages it receives that are older than the one it has
already processed.

Updates tailscale/corp#2579

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
James Tucker 445c04c938
wgengine: inject packetbuffers rather than bytes (#4220)
Plumb the outbound injection path to allow passing netstack
PacketBuffers down to the tun Read, where they are decref'd to enable
buffer re-use. This removes one packet alloc & copy, and reduces GC
pressure by pooling outbound injected packets.

Fixes #2741
Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Brad Fitzpatrick f2041c9088 all: use strings.Cut even more
Change-Id: I943ce72c6f339589235bddbe10d07799c4e37979
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 0868329936 all: use any instead of interface{}
My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 5f176f24db go.mod: upgrade to the latest wireguard-go
This pulls in a handful of fixes and an update to Go 1.18.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 61ee72940c all: use Go 1.18's strings.Cut
More remain.

Change-Id: I6ec562cc1f687600758deae1c9d7dbd0d04004cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 1b57b0380d wgengine/magicsock: remove final alloc from ReceiveFrom
And now that we don't have to play escape analysis and inlining games,
simplify the code.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 08cf54f386 wgengine/magicsock: fix goMajorVersion for 1.18 ts release
The version string changed slightly. Adapt.
And always check the current Go version to prevent future
accidental regressions. I would have missed this one had
I not explicitly manually checked it.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Maisem Ali 07f48a7bfe wgengine: handle nil netmaps when assigning isSubnetRouter.
Fixes tailscale/coral#51

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 26f27a620a wgengine/router: delete legacy netfilter rule cleanup [Linux]
This was just cleanup for an ancient version of Tailscale. Any such machines
have upgraded since then.

Change-Id: Iadcde05b37c2b867f92e02ec5d2b18bf2b8f653a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c9eca9451a ssh: make it build on darwin
For local dev testing initially. Product-wise, it'll probably only be
workable on the two unsandboxed builds.

Updates #3802

Change-Id: Ic352f966e7fb29aff897217d79b383131bf3f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 72d8672ef7 tailcfg: make Node.Hostinfo a HostinfoView
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 1b87e025e9 ssh/tailssh: move SSH code from wgengine/netstack to this new package
Still largely incomplete, but in a better home now.

Updates #3802

Change-Id: I46c5ffdeb12e306879af801b06266839157bc624
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 2db6cd1025 ipn/ipnlocal, wgengine/magicsock, logpolicy: quiet more logs
Updates #1548

Change-Id: Ied169f872e93be2857890211f2e018307d4aeadc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 86a902b201 all: adjust some log verbosity
Updates #1548

Change-Id: Ia55f1b5dc7dfea09a08c90324226fb92cd10fa00
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 6eed2811b2 wgengine/netstack: start supporting different SSH users
Updates #3802

Change-Id: I44de6897e36b1362cd74c9b10c9cbfeb9abc3dbc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick bd90781b34 ipn/ipnlocal, wgengine/netstack: use netstack for peerapi server
We're finding a bunch of host operating systems/firewalls interact poorly
with peerapi. We either get ICMP errors from the host or users need to run
commands to allow the peerapi port:

https://github.com/tailscale/tailscale/issues/3842#issuecomment-1025133727

... even though the peerapi should be an internal implementation detail.

Rather than fight the host OS & firewalls, this change handles the
server side of peerapi entirely in netstack (except on iOS), so it
never makes its way to the host OS where it might be messed with. Two
main downsides are:

1) netstack isn't as fast, but we don't really need speed for peerapi.
   And actually, with fewer trips to/from the kernel, we might
   actually make up for some of the netstack performance loss by
   staying in userspace.

2) tcpdump / Wireshark etc packet captures will no longer see the peerapi
   traffic. Oh well. Crawshaw's been wanting to add packet capture server
   support to tailscaled, so we'll probably do that sooner now.

A future change might also then use peerapi for the client-side
(except on iOS).

Updates #3842 (probably fixes, as well as many exit node issues I bet)

Change-Id: Ibc25edbb895dc083d1f07bd3cab614134705aa39
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 730aa1c89c derp/derphttp, wgengine/magicsock: prefer IPv6 to DERPs when IPv6 works
Fixes #3838

Change-Id: Ie47a2a30c7e8e431512824798d2355006d72fb6a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 1af26222b6 go.mod: bump netstack, switch to upstream netstack
Now that Go 1.17 has module graph pruning
(https://go.dev/doc/go1.17#go-command), we should be able to use
upstream netstack without breaking our private repo's build
that then depends on the tailscale.com Go module.

This is that experiment.

Updates #1518 (the original bug to break out netstack to own module)
Updates #2642 (this updates netstack, but doesn't remove workaround)

Change-Id: I27a252c74a517053462e5250db09f379de8ac8ff
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Anderson 7a18fe3dca wgengine/magicsock: make debugUseDerpRoute an opt.Bool.
Can still be constant, just needs the extra methods.

Fixes #3812

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Brad Fitzpatrick f3c0023add wgengine/netstack: add an SSH server experiment
Disabled by default.

To use, run tailscaled with:

    TS_SSH_ALLOW_LOGIN=you@bar.com

And enable with:

    $ TAILSCALE_USE_WIP_CODE=true tailscale up --ssh=true

Then ssh [any-user]@[your-tailscale-ip] for a root bash shell.
(both the "root" and "bash" part are temporary)

Updates #3802

Change-Id: I268f8c3c95c8eed5f3231d712a5dc89615a406f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 41fd4eab5c envknob: add new package for all the strconv.ParseBool(os.Getenv(..))
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.

Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c64af5e676 wgengine/netstack: clear TCP ECN bits before giving to gvisor
Updates #2642

Change-Id: Ic219442a2656dd9dc99ae1dd91e907fd3d924987
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder de4696da10 wgengine/magicsock: fix deadlock on shutdown
This fixes a deadlock on shutdown.
One goroutine is waiting to send on c.derpRecvCh before unlocking c.mu.
The other goroutine is waiting to lock c.mu before receiving from c.derpRecvCh.

#3736 has a more detailed explanation of the sequence of events.

Fixes #3736

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 185825df11 wgengine/netstack: add a missing refcount decrement after packet injection
Fixes #3762
Updates #3745 (probably fixes?)

Change-Id: I1d3f0590fd5b8adfbc9110bc45ff717bb9e79aae
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 790e41645b wgengine/netstack: add an Impl.Close method for tests
Change-Id: Idbb3fd6d749d3e4effdf96de77a1106584822fef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 166fe3fb12 wgengine/netstack: add missing error logging in a RST case
Updates #2642

Change-Id: I9f2f8fd28fc980208b0739eb9caf9db7b0977c09
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 6be48dfcc6 wgengine/netstack: fix netstack ping timeout on darwin
-W is milliseconds on darwin, not seconds, and empirically it's
milliseconds after a 1 second base.

Change-Id: I2520619e6699d9c505d9645ce4dfee4973555227
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 5404a0557b wgengine/magicsock: remove a per-DERP-packet map lookup in common case
Updates #150

Change-Id: Iffb6eccbe7ca97af97d29be63b7e37d487b3ba28
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 5a317d312d wgengine/magicsock: enable DERP Return Path Optimization (DRPO)
Turning this on at the beginning of the 1.21.x dev cycle, for 1.22.

Updates #150

Change-Id: I1de567cfe0be3df5227087de196ab88e60c9eb56
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c6c39930cc wgengine/magicsock: fix lock ordering deadlock with derphttp
Fixes #3726

Change-Id: I32631a44dcc1da3ae47764728ec11ace1c78190d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago