diff options
Diffstat (limited to 'usr.sbin/mrouted/inet.c')
| -rw-r--r-- | usr.sbin/mrouted/inet.c | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/usr.sbin/mrouted/inet.c b/usr.sbin/mrouted/inet.c index e8d5ab6f23f8..b60e3854da35 100644 --- a/usr.sbin/mrouted/inet.c +++ b/usr.sbin/mrouted/inet.c @@ -7,7 +7,7 @@ * Leland Stanford Junior University. * * - * $Id: inet.c,v 3.6 1995/06/25 18:54:45 fenner Exp $ + * $Id: inet.c,v 3.8 1995/11/29 22:36:57 fenner Rel $ */ @@ -41,6 +41,22 @@ inet_valid_host(naddr) (addr & 0xff000000) == 0)); } +/* + * Verify that a given netmask is plausible; + * make sure that it is a series of 1's followed by + * a series of 0's with no discontiguous 1's. + */ +int +inet_valid_mask(mask) + u_int32 mask; +{ + if (~(((mask & -mask) - 1) | mask) != 0) { + /* Mask is not contiguous */ + return (FALSE); + } + + return (TRUE); +} /* * Verify that a given subnet number and mask pair are credible. @@ -62,21 +78,26 @@ inet_valid_subnet(nsubnet, nmask) if ((subnet & mask) != subnet) return (FALSE); - if (subnet == 0 && mask == 0) - return (TRUE); + if (subnet == 0) + return (mask == 0); if (IN_CLASSA(subnet)) { if (mask < 0xff000000 || - (subnet & 0xff000000) == 0x7f000000) return (FALSE); + (subnet & 0xff000000) == 0x7f000000 || + (subnet & 0xff000000) == 0x00000000) return (FALSE); } else if (IN_CLASSD(subnet) || IN_BADCLASS(subnet)) { /* Above Class C address space */ return (FALSE); } - else if (subnet & ~mask) { + if (subnet & ~mask) { /* Host bits are set in the subnet */ return (FALSE); } + if (!inet_valid_mask(mask)) { + /* Netmask is not contiguous */ + return (FALSE); + } return (TRUE); } |