wg-quick: freebsd: workaround SIOCGIFSTATUS race in FreeBSD kernel

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2019-04-21 10:11:36 +09:00
parent 4471ee711c
commit 090639ae90

View file

@ -137,18 +137,30 @@ del_routes() {
done done
} }
if_exists() {
# HACK: The goal is simply to determine whether or not the interface exists. The
# straight-forward way of doing this would be `ifconfig $INTERFACE`, but this
# invokes the SIOCGIFSTATUS ioctl, which races with interface shutdown inside
# the tun driver, resulting in a kernel panic. So we work around it the stupid
# way by using the one utility that appears to call if_nametoindex fairly early
# and fails if it doesn't exist: `arp`.
if arp -i "$INTERFACE" -a -n >/dev/null 2>&1; then
return 0
else
return 1
fi
}
del_if() { del_if() {
local line monitor_pid
[[ $HAVE_SET_DNS -eq 0 ]] || unset_dns [[ $HAVE_SET_DNS -eq 0 ]] || unset_dns
exec 39< <(exec route -n monitor 2>/dev/null)
monitor_pid=$!
cmd rm -f "/var/run/wireguard/$INTERFACE.sock" cmd rm -f "/var/run/wireguard/$INTERFACE.sock"
while ifconfig "$INTERFACE" >/dev/null 2>&1; do while if_exists; do
while read -r line; do # HACK: it would be nice to `route monitor` here and wait for RTM_IFANNOUNCE
[[ $line =~ ^RTM_IFANNOUNCE:.* ]] && break # but it turns out that the announcement is made before the interface
done <&39 # disappears so we sometimes get a hang. So, we're instead left with polling
# in a sleep loop like this.
sleep 0.1
done done
kill $monitor_pid
} }
up_if() { up_if() {
@ -274,7 +286,8 @@ monitor_daemon() {
# endpoints change. # endpoints change.
while read -r event; do while read -r event; do
[[ $event == RTM_* ]] || continue [[ $event == RTM_* ]] || continue
ifconfig "$INTERFACE" >/dev/null 2>&1 || break [[ -e /var/run/wireguard/$INTERFACE.sock ]] || break
if_exists || break
[[ $AUTO_ROUTE4 -eq 1 || $AUTO_ROUTE6 -eq 1 ]] && set_endpoint_direct_route [[ $AUTO_ROUTE4 -eq 1 || $AUTO_ROUTE6 -eq 1 ]] && set_endpoint_direct_route
# TODO: set the mtu as well, but only if up # TODO: set the mtu as well, but only if up
done < <(route -n monitor)) & disown done < <(route -n monitor)) & disown