wg-quick: linux: deal with resolvconf migration more gracefully

zx2c4 · zx2c4 · commit d3b40aff9647 · 2025-05-23T21:01:53.000+02:00
When Ubuntu systems upgrade from Debian's atrocious resolvconf to the
systemd-resolve symlink, they sometimes leave around
/etc/resolvconf/interface-order, which then winds up breaking the
detection and passing the bogus 'tun.' prefix to systemd's resolvconf,
resulting in failure. Work around this by only doing the 'tun.' prefix
hack if resolvconf isn't a symlink. This is ugly but so it goes.

Reported-by: Andrei Borzenkov &lt;arvidjaar@gmail.com&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
diff --git a/src/wg-quick/linux.bash b/src/wg-quick/linux.bash
@@ -143,7 +143,7 @@ set_mtu_up() {
 }
 
 resolvconf_iface_prefix() {
-	[[ -f /etc/resolvconf/interface-order ]] || return 0
+	[[ -f /etc/resolvconf/interface-order && ! -L $(type -P resolvconf) ]] || return 0
 	local iface
 	while read -r iface; do
 		[[ $iface =~ ^([A-Za-z0-9-]+)\*$ ]] || continue

Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,7 @@ set_mtu_up() {`
`143`	`143`	`}`
`144`	`144`
`145`	`145`	`resolvconf_iface_prefix() {`
`146`		`- [[ -f /etc/resolvconf/interface-order ]] \|\| return 0`
	`146`	`+ [[ -f /etc/resolvconf/interface-order && ! -L $(type -P resolvconf) ]] \|\| return 0`
`147`	`147`	`local iface`
`148`	`148`	`while read -r iface; do`
`149`	`149`	`[[ $iface =~ ^([A-Za-z0-9-]+)\*$ ]] \|\| continue`