diff options
| -rw-r--r-- | src/ipcalc.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/ipcalc.c b/src/ipcalc.c index 7316f058..bec14eb5 100644 --- a/src/ipcalc.c +++ b/src/ipcalc.c @@ -141,7 +141,12 @@ struct in_addr calc_broadcast(struct in_addr addr, int prefix) struct in_addr broadcast; memset(&broadcast, 0, sizeof(broadcast)); - broadcast.s_addr = (addr.s_addr & mask.s_addr) | ~mask.s_addr; + +/* if prefix is set to 31 return 255.255.255.255 (RFC3021) */ + if (mask.s_addr == htonl(0xFFFFFFFE)) + broadcast.s_addr = htonl(0xFFFFFFFF); + else + broadcast.s_addr = (addr.s_addr & mask.s_addr) | ~mask.s_addr; return broadcast; } |