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>
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>
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>
This conforms to the NGINX subrequest result authentication protocol[1]
using the NGINX module `ngx_http_auth_request_module`. This is based on
the example that @peterkeen provided on Twitter[2], but with several
changes to make things more tightly locked down:
* This listens over a UNIX socket instead of a TCP socket to prevent
leakage to the network
* This uses systemd socket activation so that systemd owns the socket
and can then lock down the service to the bare minimum required to do
its job without having to worry about dropping permissions
* This provides additional information in HTTP response headers that can
be useful for integrating with various services
* This has a script to automagically create debian and redhat packages
for easier distribution
This will be written about on the Tailscale blog. There is more
information in README.md.
[1]: https://docs.nginx.com/nginx/admin-guide/security-controls/configuring-subrequest-authentication/
[2]: https://github.com/peterkeen/tailscale/blob/main/cmd/nginx-auth-proxy/nginx-auth-proxy.go
Signed-off-by: Xe Iaso <xe@tailscale.com>
This will enable me to land tests for the upcoming monitor change in
PR #4385.
Update #4385
Update #4282
Signed-off-by: James Tucker <james@tailscale.com>
In tracking down issue #4144 and reading through the netstack code in
detail, I discovered that the packet buf Clone path did not reset the
packetbuf it was getting from the sync.Pool. The fix was sent upstream
https://github.com/google/gvisor/pull/7385, and this bump pulls that in.
At this time there is no known path that this fixes, however at the time
of upstream submission this reset at least one field that could lead to
incorrect packet routing if exercised, a situation that could therefore
lead to an information leak.
Signed-off-by: James Tucker <james@tailscale.com>
While we rearrange/upstream things.
gliderlabs/ssh is forked into tempfork from our prior fork
at be8b7add40
x/crypto/ssh OTOH is forked at
https://github.com/tailscale/golang-x-crypto because it was gnarlier
to vendor with various internal packages, etc.
Its git history shows where it starts (2c7772ba30643b7a2026cbea938420dce7c6384d).
Updates #3802
Change-Id: I546e5cdf831cfc030a6c42557c0ad2c58766c65f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Primarily this is for f375784d83852b1e3ff20cc9de0648b3c0cf8525 and the
related commits that provide buffer pooling for the endpoint code paths
we use.
Signed-off-by: James Tucker <james@tailscale.com>
It includes a fix to allow us to use Go 1.18.
We can now remove our Tailscale-only build tags.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
This is required for staticcheck to process code
using Go 1.18.
This puts us on a random commit on the bleeding edge
of staticcheck, which isn't great, but there don't
appear to have been any releases yet that support 1.18.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Still not sure the exact rules of how/when/who's supposed to set
these, but this works for now on making them match. Baby steps.
Will research more and adjust later.
Updates #4146 (but not enough to fix it, something's still wrong)
Updates #3802
Change-Id: I496d8cd7e31d45fe9ede88fc8894f35dc096de67
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This unbreaks some downstream users of tailscale who end up
with build errors from importing a v0 indirect dependency.
Signed-off-by: David Anderson <danderson@tailscale.com>
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>
This is enough to handle the DNS queries as generated by Go's
net package (which our HTTP/SOCKS client uses), and the responses
generated by the ExitDNS DoH server.
This isn't yet suitable for putting on 100.100.100.100 where a number
of different DNS clients would hit it, as this doesn't yet do
EDNS0. It might work, but it's untested and likely incomplete.
Likewise, this doesn't handle anything about truncation, as the
exchanges are entirely in memory between Go or DoH. That would also
need to be handled later, if/when it's hooked up to 100.100.100.100.
Updates #3507
Change-Id: I1736b0ad31eea85ea853b310c52c5e6bf65c6e2a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
wgengine/wgcfg: introduce wgcfg.NewDevice helper to disable roaming
at all call sites (one real plus several tests).
Fixestailscale/corp#3016.
Signed-off-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
github.com/go-multierror/multierror served us well.
But we need a few feature from it (implement Is),
and it's not worth maintaining a fork of such a small module.
Instead, I did a clean room implementation inspired by its API.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Using temporary netlink fork in github.com/tailscale/netlink until we
get the necessary changes upstream in either vishvananda/netlink
or jsimonetti/rtnetlink.
Updates #391
Change-Id: I6e1de96cf0750ccba53dabff670aca0c56dffb7c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
