Files
clash-verge-rev/scripts/unset_dns.sh
T
wonfen 6ec35c8195 fix(macos): restore system DNS reliably after TUN
Detached tasks spawned on every config generation set and restored the
placeholder DNS without ordering, so a set could back up the placeholder
itself and a later restore reported success while leaving it in place.

Reconcile from the applied config under the lifecycle lock, and restore
whenever the core stops. Keep one backup per network service, never back
up the placeholder, and restore only while the service still holds it.
Scripts verify every read and write and are killed after 5 s.

Refs #8070, #8168
2026-10-06 12:47:08 +08:00

63 lines
2.2 KiB
Bash

#!/bin/bash
[ $# -lt 1 ] && echo "Usage: $0 <placeholder IP address>" && exit 1
# Prints one value of a SystemConfiguration dictionary, or nothing when the key is absent.
function sc_value() {
printf 'show %s\nquit\n' "$1" | scutil | sed -n "s/^ *$2 : //p"
}
# Prints the service's DNS servers, or "empty" when none is set; fails on any other answer.
function dns_of() {
local dns line ip='^[0-9A-Fa-f]*[.:][0-9A-Fa-f.:]*(%[[:alnum:]_.-]+)?$'
dns=$(networksetup -getdnsservers "$1") || return 1
if [ "$dns" = "There aren't any DNS Servers set on $1." ]; then
echo "empty"
return
fi
[ -n "$dns" ] || return 1
while read -r line; do
[[ $line =~ $ip ]] || return 1
done <<<"$dns"
echo "$dns"
}
result=0
# Older releases kept a single backup for whichever service was primary.
if [ -f .original_dns.txt ]; then
service_id=$(sc_value State:/Network/Global/IPv4 PrimaryService)
if [ -z "$service_id" ] || ! mkdir -p .original_dns; then
result=1
elif [ -f ".original_dns/$service_id" ]; then
rm -f .original_dns.txt || result=1
elif ! mv .original_dns.txt ".original_dns/$service_id"; then
result=1
fi
fi
for backup in .original_dns/*; do
[ -f "$backup" ] || continue
hardware_port=$(sc_value "Setup:/Network/Service/${backup##*/}" UserDefinedName)
# Kept for a service that is gone: there is nothing to write it back to.
[ -n "$hardware_port" ] || continue
if ! current_dns=$(dns_of "$hardware_port"); then
echo "Cannot read DNS servers of $hardware_port." >&2
result=1
continue
fi
# A service no longer on the placeholder was changed by someone else, and that change stands.
if [ "$current_dns" = "$1" ]; then
original_dns=$(cat "$backup") || { result=1; continue; }
# Older releases could back up the placeholder itself.
[ "$original_dns" = "$1" ] && original_dns=empty
networksetup -setdnsservers "$hardware_port" $original_dns
if [ "$(dns_of "$hardware_port")" != "$original_dns" ]; then
echo "Failed to restore DNS for $hardware_port." >&2
result=1
continue
fi
fi
rm -f "$backup" || result=1
done
rmdir .original_dns 2>/dev/null
exit $result