From 96695efe835951c667acb6017d2c169e0320574c Mon Sep 17 00:00:00 2001
From: Roy Marples <roy@marples.name>
Date: Tue, 2 Feb 2016 22:52:40 +0000
Subject: [PATCH] Use fls64 instead of ffs64 because we're interested in how
 many bits a number is so it fits.

---
 configure | 20 ++++++++++----------
 dhcp6.c   |  9 ++++-----
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/configure b/configure
index 24cac8f0..541e091f 100755
--- a/configure
+++ b/configure
@@ -985,23 +985,23 @@ if [ "$BE64ENC" = no ]; then
 	echo "#include		\"compat/endian.h\"" >>$CONFIG_H
 fi
 
-if [ -z "$FFS64" ]; then
-	printf "Testing for ffs64 ... "
-	cat <<EOF >_ffs64.c
+if [ -z "$FLS64" ]; then
+	printf "Testing for fls64 ... "
+	cat <<EOF >_fls64.c
 #include <sys/bitops.h>
 int main(void) {
-	return (int)ffs64(1337);
+	return (int)fls64(1337);
 }
 EOF
-	if $XCC _ffs64.c -o _ffs64 2>&3; then
-		FFS64=yes
+	if $XCC _fls64.c -o _fls64 2>&3; then
+		FLS64=yes
 	else
-		FFS64=no
+		FLS64=no
 	fi
-	echo "$FFS64"
-	rm -f _ffs64.c _ffs64
+	echo "$FLS64"
+	rm -f _fls64.c _fls64
 fi
-if [ "$FFS64" = yes ]; then
+if [ "$FLS64" = yes ]; then
 	echo "#define HAVE_SYS_BITOPS_H" >>$CONFIG_H
 fi
 
diff --git a/dhcp6.c b/dhcp6.c
index 0e6b958b..bd6eb52c 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -424,13 +424,13 @@ dhcp6_delegateaddr(struct in6_addr *addr, struct interface *ifp,
 
 			sla_max = 0;
 			TAILQ_FOREACH(ifi, ifp->ctx->ifaces, next) {
-				if (ifi != ifp && ifi->index > sla_max)
+				if (ifi->index > sla_max)
 					sla_max = ifi->index;
 			}
 		} else
 			sla_max = ia->sla_max;
 
-		bits = ffs32(sla_max);
+		bits = fls32(sla_max);
 
 		if (prefix->prefix_len + bits > UINT8_MAX)
 			asla.prefix_len = UINT8_MAX;
@@ -443,10 +443,9 @@ dhcp6_delegateaddr(struct in6_addr *addr, struct interface *ifp,
 				asla.prefix_len = 64;
 			else
 				asla.prefix_len = (uint8_t)ROUNDUP8(asla.prefix_len);
-
 		}
 
-#define BIT(n) (1l << (n))
+#define BIT(n) (1UL << (n))
 #define BIT_MASK(len) (BIT(len) - 1)
 		if (ia->sla_max == 0)
 			/* Work out the real sla_max from our bits used */
@@ -2355,7 +2354,7 @@ dhcp6_ifdelegateaddr(struct interface *ifp, struct ipv6_addr *prefix,
 	    sla, ia)) == -1)
 		return NULL;
 
-	if (ffs64(sla->suffix) > 128 - pfxlen) {
+	if (fls64(sla->suffix) > 128 - pfxlen) {
 		logger(ifp->ctx, LOG_ERR,
 		    "%s: suffix %" PRIu64 " + prefix_len %d > 128",
 		    ifp->name, sla->suffix, pfxlen);