mactelnetd: remove redundant include

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
mactelnet: remove _GNU_SOURCE define, pass it via Makefile instead, fix link order

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
interfaces: properly deal with missing broadcast addresses in net_ifaces_add()

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
mndp, protocol: skip interfaces w/o broadcast when sending MNDP discovery requests

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
mactelnet: do not free pointer returned by getpass() - it points to a static buffer

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
mactelnet: remove extraneous have_username and have_password variables

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
mactelnet: flush stdout when prompting for login (fixes "Login:" prompt with musl)

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>