diff options
Diffstat (limited to 'lib/prefix.c')
-rw-r--r-- | lib/prefix.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/lib/prefix.c b/lib/prefix.c index ceda08de..5e8cff04 100644 --- a/lib/prefix.c +++ b/lib/prefix.c @@ -2317,6 +2317,21 @@ static const char map64kto17_nbo[0xffff + 1] = #define MASKBIT(offset) ((0xff << (PNBBY - (offset))) & 0xff) +unsigned int +prefix_bit (const u_char *prefix, const u_char prefixlen) +{ + unsigned int offset = prefixlen / 8; + unsigned int shift = 7 - (prefixlen % 8); + + return (prefix[offset] >> shift) & 1; +} + +unsigned int +prefix6_bit (const struct in6_addr *prefix, const u_char prefixlen) +{ + return prefix_bit((const u_char *) &prefix->s6_addr, prefixlen); +} + /* Address Famiy Identifier to Address Family converter. */ int afi2family (afi_t afi) |