This commit modifies the existing unit tests for TLS DNS and TCP DNS
in such a way that the new Stream DNS transport is used as it is
intended to be a drop-in replacement for these two transports.
After the loop manager refactoring TCP DNS and TLS DNS unit tests
ended up broken.
The problem is that in these unit tests the code is written in such a
way that for establishing a new connection tcpdns_connect() and
tlsdns_connect() functions are used. However, in these tests as a
connection callback function connect_connect_cb() is used. The
function logic is responsible for determining the function for
establishing subsequent connection.
To do so, it called get_stream_connect_function() ... which can return
only tcp_connect() or tls_connect(), not tcpdns_connect() or
tlsdns_connect(). That is definitely *not* what was implied.
All this time the unit tests were testing something, but now what was
intended.
This commit fixes the problem by passing the tcpdns_connect() and
tlsdns_connect() function pointers to connect_connect_cb().
In rare circumstances, the UDP port for the listening socket and the UDP
port for the connecting socket might be the same. Because we use the
"reuse" port socket option, this isn't caught when binding the socket,
and thus the connected client socket could send a datagram to itself,
completely bypassing the server. This doesn't happen under normal
operation mode because `named` is listening on a privileged port (53),
and even if not, it doesn't usually talk to itself as the tests do.
Pick an arbitrary port for listening (9153-9156) that is outside the
ephemeral port range for the network manager related unit tests (except
the `doh_test).
The netmgr_test unit test has been subdivided into tcp_test,
tcpdns_test, tls_test, tlsdns_test, and udp_test components.
These have been updated to use the new loopmgr.
