• Ondřej Zajíček's avatar
    OSPF: Fixes validation of LSA checksums · 30d09eb9
    Ondřej Zajíček authored
    Prior to this patch, BIRD validates the OSPF LSA checksum by calculating
    a new checksum and comparing it with the checksum in the header. Due to
    the specifics of the Fletcher checksum used in OSPF, this is not
    necessarily correct as the checkbytes in the header may be calculated via
    a different means and end up with a different value that is nonetheless
    still correct.
    
    The documented means of validating the checksum as specified in RFC 905
    B.4 is to calculate c0 and c1 from the unchanged contents of the packet,
    which must result in a zero value to be considered valid.
    
    Thanks to Chris Boot for the patch.
    30d09eb9
lsupd.c 18 KB