Initialise our_tap_ll to ip6.gw when suitable

In every place we use our_tap_ll, we only use it as a fallback if the
IPv6 gateway address is not link-local.  We can avoid that conditional at
use time by doing it at initialisation of our_tap_ll instead.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

4 files changed, 6 insertions, 12 deletions

diff --git a/conf.c b/conf.c
index 1130ce5..954f20e 100644
--- a/conf.c
+++ b/conf.c
@@ -721,6 +721,9 @@ static unsigned int conf_ip6(unsigned int ifi,
 
 	ip6->addr_seen = ip6->addr;
 
+	if (IN6_IS_ADDR_LINKLOCAL(&ip6->gw))
+		ip6->our_tap_ll = ip6->gw;
+
 	if (MAC_IS_ZERO(mac)) {
 		rc = nl_link_get_mac(nl_sock, ifi, mac);
 		if (rc < 0) {
diff --git a/dhcpv6.c b/dhcpv6.c
index fa1dccc..14a5c7e 100644
--- a/dhcpv6.c
+++ b/dhcpv6.c
@@ -453,10 +453,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
 
 	c->ip6.addr_ll_seen = *saddr;
 
-	if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw))
-		src = &c->ip6.gw;
-	else
-		src = &c->ip6.our_tap_ll;
+	src = &c->ip6.our_tap_ll;
 
 	mh = packet_get(p, 0, sizeof(*uh), sizeof(*mh), NULL);
 	if (!mh)
diff --git a/fwd.c b/fwd.c
index dccc947..75dc015 100644
--- a/fwd.c
+++ b/fwd.c
@@ -317,10 +317,7 @@ uint8_t fwd_nat_from_host(const struct ctx *c, uint8_t proto,
 	} else if (inany_is_loopback6(&tgt->oaddr) ||
 		   inany_equals6(&tgt->oaddr, &c->ip6.addr_seen) ||
 		   inany_equals6(&tgt->oaddr, &c->ip6.addr)) {
-		if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw))
-			tgt->oaddr.a6 = c->ip6.gw;
-		else
-			tgt->oaddr.a6 = c->ip6.our_tap_ll;
+		tgt->oaddr.a6 = c->ip6.our_tap_ll;
 	}
 
 	if (inany_v4(&tgt->oaddr)) {
diff --git a/ndp.c b/ndp.c
index 3a76b00..a1ee834 100644
--- a/ndp.c
+++ b/ndp.c
@@ -341,10 +341,7 @@ dns_done:
 	else
 		c->ip6.addr_seen = *saddr;
 
-	if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw))
-		rsaddr = &c->ip6.gw;
-	else
-		rsaddr = &c->ip6.our_tap_ll;
+	rsaddr = &c->ip6.our_tap_ll;
 
 	if (ih->icmp6_type == NS) {
 		dlen = sizeof(struct ndp_na);