After update from 10.14 beta 1 to beta 2 app started to return error
We're trying to listen to port 53 using NWListener and according to netstat and lsof
$ netstat -aLn
Current listen queue sizes (qlen/incqlen/maxqlen)
Listen Local Address
0/0/10 *.53
$netstat -p udp -n
Active Internet connections
Proto Recv-Q Send-Q Local Address Foreign Address (state)
udp4 0 0 *.53 *.*
$lsof -i :53
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
Privaguar 4875 administrator 10u IPv4 0xcc9a81e8ff81b149 0t0 UDP *:domain
Privaguar 4875 administrator 11u IPv4 0xcc9a81e9060b9eb1 0t0 TCP *:domain (LISTEN)
Both TCP and UDP listening on port is suceeding but when new UDP connection arrives
"nw_listener_inbox_accept_udp bind failed [13: Permission denied]"
error is returned.
Strange, but TCP socket on port 53 still works.
We believe this could be due to priveleged port being requested, because after changing UDP listening port from 53 to 1053 app worked again.
If this is no longer possible what are the options for listening to priveleged ports in macOS sandboxed environment ?
Are there any limitations regarding priveleged ports(<1024) for NWListener ?
