Commit Graph

39 Commits (11f7f7d4a0e1758c5b0ad0ac7c9d7be67997627c)

Author SHA1 Message Date
Brad Fitzpatrick 90bd74fc05 net/dns: add a health warning when Linux /etc/resolv.conf is overwritten
Change-Id: I925b4d904bc7ed920bc5afee11e6dcb2ffc2fbfd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 001f482aca net/dns: make "direct" mode on Linux warn on resolv.conf fights
Run an inotify goroutine and watch if another program takes over
/etc/inotify.conf. Log if so.

For now this only logs. In the future I want to wire it up into the
health system to warn (visible in "tailscale status", etc) about the
situation, with a short URL to more info about how you should really
be using systemd-resolved if you want programs to not fight over your
DNS files on Linux.

Updates #4254 etc etc

Change-Id: I86ad9125717d266d0e3822d4d847d88da6a0daaa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Eng Zer Jun f0347e841f refactor: move from io/ioutil to io and os packages
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.

Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2 years ago
Brad Fitzpatrick a12aad6b47 all: convert more code to use net/netip directly
perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 7eaf5e509f net/netaddr: start migrating to net/netip via new netaddr adapter package
Updates #5162

Change-Id: Id7bdec303b25471f69d542f8ce43805328d56c12
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 7d897229d9 net/dns: ignore permission errors on Synology DSM7 for now
Updates #4017

Change-Id: Ia7fd4df47588c010dea8e63d88f397cc8eb748e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c988bd6ed1 net/dns/resolvconffile: unify three /etc/resolv.conf parsers into new package
Change-Id: I2120893ca802d12f1bd0407d49077d3672627d33
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick eb26c081b1 net/dns: bound time we wait on restarting systemd-resolved in another place
Fixes #3629
Updates #3537

Change-Id: I5d4b6acfcfdf0e3efcf6eb49c5e6cf4521e4baed
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cab5c46481 net/dns: bound how long we block looking for, restarting systemd-resolved
Fixes #3537

Change-Id: Iba6a3cde75983490d4072b5341f48dbfa2f997c0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder d10cefdb9b net/dns: require space after nameserver/search parsing resolv.conf
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 9f00510833 net/dns: handle comments in resolv.conf
Currently, comments in resolv.conf cause our parser to fail,
with error messages like:

ParseIP("192.168.0.100 # comment"): unexpected character (at " # comment")

Fix that.

Noticed while looking through logs.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Denton Gentry 139a6c4c9c net/dns: detect when resolvconf points to systemd-resolved.
There are /etc/resolv.conf files out there where resolvconf wrote
the file but pointed to systemd-resolved as the nameserver.
We're better off handling those as systemd-resolved.

> # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
> #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
> # 127.0.0.53 is the systemd-resolved stub resolver.
> # run "systemd-resolve --status" to see details about the actual nameservers.

Fixes https://github.com/tailscale/tailscale/issues/3026
Signed-off-by: Denton Gentry <dgentry@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 Anderson 04d24d3a38 net/dns: move directManager function below directManager's definition.
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson 422ea4980f net/dns: remove a tiny wrapper function that isn't contributing anything.
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson b3b1c06b3a net/dns: only restart systemd-resolved if we changed /etc/resolv.conf.
Reported on IRC: in an edge case, you can end up with a directManager DNS
manager and --accept-dns=false, in which case we should do nothing, but
actually end up restarting resolved whenever the netmap changes, even though
the user told us to not manage DNS.

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Crawshaw 0ac2130590 net/dns: resolveConfExists reading the wrong error
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Brad Fitzpatrick 36ffd509de net/dns: avoid Linux PolicyKit GUI dialog during tests
Fixes #2672

Signed-off-by: Brad Fitzpatrick <bradfitz@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
David Crawshaw 9b063b86c3 net/dns: factor directManager out over an FS interface
This is preliminary work for using the directManager as
part of a wslManager on windows, where in addition to configuring
windows we'll use wsl.exe to edit the linux file system and modify the
system resolv.conf.

The pinholeFS is a little funky, but it's designed to work through
simple unix tools via wsl.exe without invoking bash. I would not have
thought it would stand on its own like this, but it turns out it's
useful for writing a test for the directManager.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
David Crawshaw 80b1308974 net/dns: remove ref to managerImpl
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Josh Bleecher Snyder 20e04418ff net/dns: add GOOS build tags
Fixes #1786

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
David Anderson 53213114ec net/dns: make debian_resolvconf correctly clear DNS configs.
More of #1720.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 3b1ab78954 net/dns: restore resolv.conf when given an empty config in directManager.
Fixes #1720.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1f9b73a531 net/dns: fix freebsd DNS manager selection.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 854d5d36a1 net/dns: return error from NewOSManager, use it to initialize NM.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 61b361bac0 net/dns: teach the openresolv manager to read DNS config.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 5480189313 net/dns: implement a DNS override workaround for legacy resolvconf.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1a371b93be util/dnsname: add FQDN type, use throughout codebase.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson e638a4d86b net/dns: make directManager support split DNS, and work in sandboxes.
Fixes #1495, #683.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4a64d2a603 net/dns: some post-review cleanups.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 68f76e9aa1 net/dns: add GetBaseConfig to OSConfigurator interface.
Part of #953, required to make split DNS work on more basic
platforms.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson e0e677a8f6 net/dns: split out search domains and match domains in OSConfig.
It seems that all the setups that support split DNS understand
this distinction, and it's an important one when translating
high-level configuration.

Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson de6dc4c510 net/dns: add a Primary field to OSConfig.
Currently ignored.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson b2a597b288 net/dns: rename Set to SetDNS in OSConfigurator.
wgengine/router.CallbackRouter needs to support both the Router
and OSConfigurator interfaces, so the setters can't both be called
Set.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson befd8e4e68 net/dns: replace managerImpl with OSConfigurator in code.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 8af9d770cf net/dns: rename Config to OSConfig.
Making way for a new higher level config struct.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson fcfc0d3a08 net/dns: remove ManagerConfig, pass relevant args directly.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9f7f2af008 wgengine/router/dns: move to net/dns.
Preparation for merging the APIs and whatnot.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago