diff options
| -rw-r--r-- | lib/prefix.c | 21 | ||||
| -rw-r--r-- | lib/prefix.h | 9 |
2 files changed, 27 insertions, 3 deletions
diff --git a/lib/prefix.c b/lib/prefix.c index 61e0f195..5a3e71bf 100644 --- a/lib/prefix.c +++ b/lib/prefix.c @@ -118,7 +118,14 @@ prefix_copy (struct prefix *dest, struct prefix *src) } } -/* If both prefix structure is same then return 1 else return 0. */ +/* + * Return 1 if the address/netmask contained in the prefix structure + * is the same, and else return 0. For this routine, 'same' requires + * that not only the prefix length and the network part be the same, + * but also the host part. Thus, 10.0.0.1/8 and 10.0.0.2/8 are not + * the same. Note that this routine has the same return value sense + * as '==' (which is different from prefix_cmp). + */ int prefix_same (struct prefix *p1, struct prefix *p2) { @@ -136,8 +143,16 @@ prefix_same (struct prefix *p1, struct prefix *p2) return 0; } -/* When both prefix structure is not same, but will be same after - applying mask, return 0. otherwise, return 1 */ +/* + * Return 0 if the network prefixes represented by the struct prefix + * arguments are the same prefix, and 1 otherwise. Network prefixes + * are considered the same if the prefix lengths are equal and the + * network parts are the same. Host bits (which are considered masked + * by the prefix length) are not significant. Thus, 10.0.0.1/8 and + * 10.0.0.2/8 are considered equivalent by this routine. Note that + * this routine has the same return sense as strcmp (which is different + * from prefix_same). + */ int prefix_cmp (struct prefix *p1, struct prefix *p2) { diff --git a/lib/prefix.h b/lib/prefix.h index 7d7cde68..5884640a 100644 --- a/lib/prefix.h +++ b/lib/prefix.h @@ -23,6 +23,15 @@ #ifndef _ZEBRA_PREFIX_H #define _ZEBRA_PREFIX_H +/* + * A struct prefix contains an address family, a prefix length, and an + * address. This can represent either a 'network prefix' as defined + * by CIDR, where the 'host bits' of the prefix are 0 + * (e.g. AF_INET:10.0.0.0/8), or an address and netmask + * (e.g. AF_INET:10.0.0.9/8), such as might be configured on an + * interface. + */ + /* IPv4 and IPv6 unified prefix structure. */ struct prefix { |