The tcp_open_active() and tcp_open_passive() functions don't really have
any strong dependencies on TCP. With a couple of simple changes they
can be used for UDP also. Since this is useful for Netflow, this commit
does so.
Until now, tcp_open_active() and tcp_open_passive() have only been used
in situations where there is a reasonable default port, e.g. OFP_TCP_PORT.
But for NetFlow there is no universal default, so enhance these functions
so that they can require the user to specify a port explicitly.
Crossported from the 'db' branch, where this is useful for JSON-RPC, which
also has no widely known port.
Until now, setting a netflow collector to a DNS name would cause
secchan to attempt to resolve that DNS name each time that the set of
netflow collectors is re-set. For the vswitch, this is every time that
the vswitch reconfigures itself.
Unfortunately, DNS lookup within secchan cannot work as currently
implemented, because it needs both an asynchronous DNS resolver library
and in-band control updates. Currently we have neither. Attempting to
look up DNS anyway just hangs.
This commit disables DNS lookup entirely, and updates the documentation to
change user expectations. DNS still won't work, but at least it won't
hang.
Bug #1609.
The TCP and SSL vconn implementations had a lot of common code to make
and accept TCP connections, which this commit factors out into common
functions in socket-util.c.
Also adds the ability to bind ptcp and pssl vconns to a particular IP
address instead of the wildcard address.
