isisd: drop hellos without supported protocol list

isisd should not form adjacencies on receiving an IS-IS Hello without a
list of supported protocols (cf. RFC 1195 s4.4 p32 "Maintaining Router
Adjacencies")  Also fixes memleaks in these error cases.

* isisd/isis_pdu.c: improve TLVFLAG_NLPID handling

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Tested-by: Martin Winter <mwinter@opensourcerouting.org>
1 file changed