socket: clear port when unable to generate local port

When running out of local ports, _nl_socket_generate_local_port_no_release()
would leave the socket with port UINT32_MAX. That means if nl_connect()
fails due to out-of-ports, it would leave the port id assigned to an
invalid port and the socket instance was not re-usable until the user
called nl_socket_set_local_port(). Fix that by resetting the local port
to zero.

Thereby, also change generate_local_port() to return zero when
running out of ports. zero is a more natural value for ~no port found~.
It also matches the port that _nl_socket_generate_local_port_no_release()
uses when failing to generate a port.

Also ensure that zero cannot be returned as valid port by generate_local_port().
Arguably, that would only be possible if (getpid() & 0x3FFFFF)
returns zero. Just be extra cautious.

Signed-off-by: Thomas Haller <thaller@redhat.com>

0 files changed, 0 insertions, 0 deletions