Commit Graph

10 Commits (e815ae0ec4b718486af9be3a30d3058b65b28c4e)

Author SHA1 Message Date
Andrew Dunham 53a5d00fff net/dns: ensure /etc/resolv.conf is world-readable even with a umask
Previously, if we had a umask set (e.g. 0027) that prevented creating a
world-readable file, /etc/resolv.conf would be created without the o+r
bit and thus other users may be unable to resolve DNS.

Since a umask only applies to file creation, chmod the file after
creation and before renaming it to ensure that it has the appropriate
permissions.

Updates #12609

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I2a05d64f4f3a8ee8683a70be17a7da0e70933137
4 months ago
Aaron Klotz 3511d1f8a2 cmd/tailscaled, net/dns, wgengine/router: start Windows child processes with DETACHED_PROCESS when I/O is being piped
When we're starting child processes on Windows that are CLI programs that
don't need to output to a console, we should pass in DETACHED_PROCESS as a
CreationFlag on SysProcAttr. This prevents the OS from even creating a console
for the child (and paying the associated time/space penalty for new conhost
processes). This is more efficient than letting the OS create the console
window and then subsequently trying to hide it, which we were doing at a few
callsites.

Fixes #12270

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
5 months ago
Brad Fitzpatrick 745931415c health, all: remove health.Global, finish plumbing health.Tracker
Updates #11874
Updates #4136

Change-Id: I414470f71d90be9889d44c3afd53956d9f26cd61
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Aaron Klotz 9687f3700d net/dns: deal with Windows wsl.exe hangs
Despite the fact that WSL configuration is still disabled by default, we
continue to log the machine's list of WSL distros as a diagnostic measure.

Unfortunately I have seen the "wsl.exe -l" command hang indefinitely. This patch
adds a (more than reasonable) 10s timeout to ensure that tailscaled does not get
stuck while executing this operation.

I also modified the Windows implementation of NewOSConfigurator to do the
logging asynchronously, since that information is not required in order to
continue starting up.

Fixes #7476

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Will Norris 71029cea2d all: update copyright and license headers
This updates all source files to use a new standard header for copyright
and license declaration.  Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.

This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.

Updates #6865

Signed-off-by: Will Norris <will@tailscale.com>
2 years ago
Aaron Klotz f93cf6fa03 net/dns: fix checking for wrapped error when attempting to read wsl.conf for Windows WSL2
Fixes https://github.com/tailscale/tailscale/issues/3437

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
3 years ago
David Anderson 124363e0ca net/dns: detect and decode UTF-16 from wsl.exe earlier.
Fixes #3170

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson a320d70614 net/dns: fall back to copy+delete/truncate if moving to/from /etc/resolv.conf fails.
In some containers, /etc/resolv.conf is a bind-mount from outside the container.
This prevents renaming to or from /etc/resolv.conf, because it's on a different
filesystem from linux's perspective. It also prevents removing /etc/resolv.conf,
because doing so would break the bind-mount.

If we find ourselves within this environment, fall back to using copy+delete when
renaming to /etc/resolv.conf, and copy+truncate when renaming from /etc/resolv.conf.

Fixes #3000

Co-authored-by: Denton Gentry <dgentry@tailscale.com>
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Crawshaw 6b9f8208f4 net/dns: do not run wsl.exe as LocalSystem
It doesn't work. It needs to run as the user.

	https://github.com/microsoft/WSL/issues/4803

The mechanism for doing this was extracted from:

	https://web.archive.org/web/20101009012531/http://blogs.msdn.com/b/winsdk/archive/2009/07/14/launching-an-interactive-process-from-windows-service-in-windows-vista-and-later.aspx

While here, we also reclaculate WSL distro set on SetDNS.
This accounts for:

	1. potential inability to access wsl.exe on startup
	2. WSL being installed while Tailscale is running
	3. A new WSL distrobution being installed

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
David Crawshaw 1147c7fd4f net/dns: set WSL /etc/resolv.conf
We also have to make a one-off change to /etc/wsl.conf to stop every
invocation of wsl.exe clobbering the /etc/resolv.conf. This appears to
be a safe change to make permanently, as even though the resolv.conf is
constantly clobbered, it is always the same stable internal IP that is
set as a nameserver. (I believe the resolv.conf clobbering predates the
MS stub resolver.)

Tested on WSL2, should work for WSL1 too.

Fixes #775

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago