Files
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

81 lines
2.6 KiB
Bash

#!/bin/bash
function is_valid_ipv4() {
local ip=$1
local IFS='.'
local -a octets
[[ ! $ip =~ ^([0-9]+\.){3}[0-9]+$ ]] && return 1
read -r -a octets <<<"$ip"
[ "${#octets[@]}" -ne 4 ] && return 1
for octet in "${octets[@]}"; do
if ! [[ "$octet" =~ ^[0-9]+$ ]] || ((octet < 0 || octet > 255)); then
return 1
fi
done
return 0
}
function is_valid_ipv6() {
local ip=$1
if [[ ! $ip =~ ^([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}$ ]] &&
[[ ! $ip =~ ^(([0-9a-fA-F]{0,4}:){0,7}:|(:[0-9a-fA-F]{0,4}:){0,6}:[0-9a-fA-F]{0,4})$ ]]; then
return 1
fi
return 0
}
function is_valid_ip() {
is_valid_ipv4 "$1" || is_valid_ipv6 "$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"
}
[ $# -lt 1 ] && echo "Usage: $0 <IP address>" && exit 1
! is_valid_ip "$1" && echo "$1 is not a valid IP address." && exit 1
# Backups are keyed by service ID, which survives renaming the service and renumbering its interface.
service_id=$(sc_value State:/Network/Global/IPv4 PrimaryService)
hardware_port=$(sc_value "Setup:/Network/Service/$service_id" UserDefinedName)
[ -z "$hardware_port" ] && echo "No primary network service." && exit 1
original_dns=$(dns_of "$hardware_port") || { echo "Cannot read DNS servers of $hardware_port." >&2; exit 1; }
backup=".original_dns/$service_id"
mkdir -p .original_dns || exit 1
# Older releases kept a single backup for whichever service was primary.
if [ -f .original_dns.txt ]; then
if [ -f "$backup" ]; then
rm -f .original_dns.txt || exit 1
else
mv .original_dns.txt "$backup" || exit 1
fi
fi
# The placeholder is ours, not the user's: keep the backup taken before it was applied.
if [ "$original_dns" != "$1" ]; then
echo "$original_dns" >"$backup" || exit 1
networksetup -setdnsservers "$hardware_port" "$1"
[ "$(dns_of "$hardware_port")" = "$1" ] || { echo "Failed to set DNS for $hardware_port." >&2; exit 1; }
elif [ ! -f "$backup" ]; then
echo "empty" >"$backup" || exit 1
fi