tree 3ae464646ef28312ddbd6f2ced625622a43ab7da
parent ab6d6cf3aa5ca75f4b110ac4282a07adcc981e59
author Neels Hofmeyr <neels@hofmeyr.de> 1570245153 +0200
committer Neels Hofmeyr <neels@hofmeyr.de> 1572615238 +0100

add osmo_sockaddr_str_is_nonzero()

Often, an IP address of 0.0.0.0 is considered an unset value (for clients
requiring a server address; not for listening on "any").

osmo_sockaddr_str_is_set() does return false when the port is 0, but there is
no simple way to tell whether the IP address is actually set to a server
address.

Add osmo_sockaddr_str_is_nonzero() to return false if:
- the port is zero, or
- the IP address is zero (0.0.0.0 or ::0), or
- the IP address cannot be parsed.

A practical use example: osmo-msc so far accepts an RTP IP address of 0.0.0.0
as valid. I noticed when trying to trigger error handling from a ttcn3 test.
osmo-msc can use this function to reject invalid addresses from MGCP messages.

Related: I53ddb19a70fda3deb906464e1b89c12d9b4c7cbd (osmo-msc)
Change-Id: I73cbcab90cffcdc9a5f8d5281c57c1f87b2c3550