lib: fix type-punning in ip_masklen()
ip_masklen() was likely to return incorrect results after being compiled
with -fstrict-aliasing (-O2, -O3, -Os)
diff --git a/lib/prefix.c b/lib/prefix.c
index 7d31af2..580ba31 100644
--- a/lib/prefix.c
+++ b/lib/prefix.c
@@ -2592,8 +2592,13 @@
u_char
ip_masklen (struct in_addr netmask)
{
- u_int16_t * int16 = (u_int16_t *) &netmask.s_addr;
- return map64kto17_nbo[int16[0]] + map64kto17_nbo[int16[1]];
+ union
+ {
+ u_int32_t int32;
+ u_int16_t int16[2];
+ } u;
+ u.int32 = netmask.s_addr;
+ return map64kto17_nbo[u.int16[0]] + map64kto17_nbo[u.int16[1]];
}
/* Apply mask to IPv4 prefix (network byte order). */