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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>
2022-04-20 22:21:35 -07:00
.bencher bencher: add config to suppress failures on benchmark regressions. 2021-10-01 16:16:02 -07:00
.github Revert ".github/workflows: work around golang/go#51629" 2022-04-13 14:27:01 -07:00
atomicfile atomicfile: don't Chmod on windows 2020-07-15 12:31:40 -07:00
chirp all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
client/tailscale cmd/tailscale, etc: make "tailscale up --ssh" fail fast when unavailable 2022-04-18 09:45:46 -07:00
cmd wgengine/router,util/kmod: load & log xt_mark 2022-04-20 22:21:35 -07:00
control tailcfg, logtail: provide Debug bit to disable logtail 2022-04-18 13:53:13 -07:00
derp derp/derphttp,net/netcheck: improve netcheck behavior under MITM proxies 2022-04-19 12:47:57 -07:00
disco types/key: export constants for key size, not a method. 2021-10-29 17:39:04 -07:00
docs fix minor typo 2021-11-16 11:03:43 -08:00
envknob ipn/ipnlocal: reject tailscale up --ssh if disabled on tailnet 2022-04-20 11:38:27 -07:00
health net/dns: add health check for particular broken-ish Linux DNS config 2022-02-16 10:40:04 -08:00
hostinfo hostinfo, tailcfg: add desktop detection on Linux to hostinfo 2022-04-18 14:22:15 -07:00
internal/tooldeps util/deephash: move internal/deephash to util/deephash 2021-07-02 21:33:02 -07:00
ipn ipn/ipnlocal: close peerapi listeners on LocalBackend.Shutdown 2022-04-20 19:25:42 -07:00
kube all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
log all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
logpolicy all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
logtail tailcfg, logtail: provide Debug bit to disable logtail 2022-04-18 13:53:13 -07:00
metrics all: use testingutil.MinAllocsPerRun 2021-10-28 12:48:37 -07:00
net cmd/tailscale: add "debug via" subcommand to do CIDR math for via ranges 2022-04-20 14:47:48 -07:00
packages/deb all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
paths cmd/tailscaled: default to userspace-networking mode on gokrazy, set paths 2022-03-01 20:34:45 -08:00
portlist envknob: add new package for all the strconv.ParseBool(os.Getenv(..)) 2022-01-24 11:51:23 -08:00
prober prober: used keyed initializer for LimitedReader. 2022-03-26 21:45:27 -07:00
safesocket safesocket: add ConnectionStrategy, provide control over fallbacks 2021-12-09 15:46:38 -08:00
scripts scripts/install: add Alma Linux. 2022-04-20 17:43:49 -07:00
smallzstd smallzstd: new package that constructs zstd small encoders/decoders. 2020-07-02 16:13:06 -07:00
ssh/tailssh ssh/tailssh: fix double SSH-2.0- prefix in greeting banner 2022-04-20 20:08:39 -07:00
syncs syncs: use TryLock and TryRLock instead of unsafe 2022-03-17 10:57:41 -07:00
tailcfg tailcfg: document SSHPrincipal.PubKeys URL expansions 2022-04-20 20:12:37 -07:00
tempfork ssh/tailssh: send banner messages during auth, move more to conn 2022-04-20 18:34:11 -07:00
tool tool/go: add wrapper to download and use go.toolchain.rev go version. 2022-01-04 09:45:29 -08:00
tsconst net/interfaces/windows: update Tailscale interface detection logic to 2021-11-08 07:44:33 -08:00
tsnet tsnet: set Hostinfo.Package to "tsnet" on use 2022-03-25 09:26:02 -07:00
tstest tstest/iosdeps: add test for forbidden iOS dependencies 2022-04-20 12:30:23 -07:00
tstime tstime/mono: fix Before function comment 2022-03-05 15:05:57 -08:00
tsweb tsweb: add PrometheusVar, for vars that want to output varz themselves. 2022-03-21 12:33:18 -07:00
types net/dns: schedule DoH upgrade explicitly, fix Resolver.Addr confusion 2022-04-19 12:00:22 -07:00
util wgengine/router,util/kmod: load & log xt_mark 2022-04-20 22:21:35 -07:00
version version: use Go 1.18's git stamping as default implementation 2022-03-16 14:53:51 -07:00
wf all: use any instead of interface{} 2022-03-17 11:35:09 -07:00
wgengine wgengine/router,util/kmod: load & log xt_mark 2022-04-20 22:21:35 -07:00
words words: more hamsters, less hampsters (#3938) 2022-02-14 15:15:30 -05:00
.gitattributes .: add .gitattributes entry to use Go hunk-header driver 2021-12-03 17:56:02 -08:00
.gitignore Makefile: update make spk target to use the new go spk builder 2022-01-21 12:27:00 -08:00
AUTHORS Move Linux client & common packages into a public repo. 2020-02-09 09:32:57 -08:00
CODE_OF_CONDUCT.md Add a code of conduct. 2020-02-10 22:16:30 -08:00
Dockerfile Dockerfile: require Go 1.18 2022-03-16 12:45:28 -07:00
Dockerfile.base Dockerfile.base: update to alpine:3.15 2022-01-07 07:33:25 -08:00
LICENSE LICENSE: Reformat for Github 2021-01-24 16:20:22 -08:00
Makefile Makefile: add tidy target 2022-03-21 11:06:13 -07:00
PATENTS Move Linux client & common packages into a public repo. 2020-02-09 09:32:57 -08:00
README.md README.md: update current Go release 2022-03-16 12:45:28 -07:00
SECURITY.md Add a SECURITY.md for vulnerability reports. 2020-02-11 10:26:41 -08:00
VERSION.txt VERSION.txt: This is 1.23. 2022-02-23 15:51:28 -08:00
api.md api: update acl/validate data format (#4366) 2022-04-07 10:33:52 -07:00
build_dist.sh tool/go: add wrapper to download and use go.toolchain.rev go version. 2022-01-04 09:45:29 -08:00
build_docker.sh tool/go: add wrapper to download and use go.toolchain.rev go version. 2022-01-04 09:45:29 -08:00
go.mod wgengine/router,util/kmod: load & log xt_mark 2022-04-20 22:21:35 -07:00
go.sum wgengine/router,util/kmod: load & log xt_mark 2022-04-20 22:21:35 -07:00
go.toolchain.branch go.toolchain.branch: upgrade to Go 1.18 2022-03-16 12:45:28 -07:00
go.toolchain.rev go.toolchain.rev: update to go1.18.1 (#4438) 2022-04-18 14:42:58 -07:00
pull-toolchain.sh go.toolchain.rev: add update script 2022-01-10 14:55:04 -08:00
shell.nix shell.nix: use tailscale-go for compilation 2022-04-08 14:10:50 -07:00
staticcheck.conf staticcheck.conf: remove unnecessary warning 2021-06-22 12:26:13 -07:00
version-embed.go go.toolchain.rev: add Go toolchain rev, tool to print it out 2022-01-03 11:56:27 -08:00

README.md

Tailscale

https://tailscale.com

Private WireGuard® networks made easy

Overview

This repository contains all the open source Tailscale client code and the tailscaled daemon and tailscale CLI tool. The tailscaled daemon runs on Linux, Windows and macOS, and to varying degrees on FreeBSD, OpenBSD, and Darwin. (The Tailscale iOS and Android apps use this repo's code, but this repo doesn't contain the mobile GUI code.)

The Android app is at https://github.com/tailscale/tailscale-android

The Synology package is at https://github.com/tailscale/tailscale-synology

Using

We serve packages for a variety of distros at https://pkgs.tailscale.com .

Other clients

The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers that are not open source.

Building

go install tailscale.com/cmd/tailscale{,d}

If you're packaging Tailscale for distribution, use build_dist.sh instead, to burn commit IDs and version info into the binaries:

./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled

If your distro has conventions that preclude the use of build_dist.sh, please do the equivalent of what it does in your distro's way, so that bug reports contain useful version information.

We only guarantee to support the latest Go release and any Go beta or release candidate builds (currently Go 1.18) in module mode. It might work in earlier Go versions or in GOPATH mode, but we're making no effort to keep those working.

Bugs

Please file any issues about this code or the hosted service on the issue tracker.

Contributing

PRs welcome! But please file bugs. Commit messages should reference bugs.

We require Developer Certificate of Origin Signed-off-by lines in commits.

About Us

Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:

WireGuard is a registered trademark of Jason A. Donenfeld.