inet6: Fix default route not being installed

We need to check for global addresses on any forwarding interface,
not just the interface we received the RA on.
Otherwise this breaks routers who get a default route only
from the RA and IPv6 addresses only by prefix delegation to
other interfaces.

1 files changed, 21 insertions, 18 deletions

diff --git a/src/ipv6.c b/src/ipv6.c
index ca54dab9..99f6a8a4 100644
--- a/src/ipv6.c
+++ b/src/ipv6.c
@@ -1065,28 +1065,31 @@ ipv6_getstate(struct interface *ifp)
 }
 
 struct ipv6_addr *
-ipv6_ifanyglobal(struct interface *ifp)
+ipv6_anyglobal(struct interface *sifp)
 {
+	struct interface *ifp;
 	struct ipv6_state *state;
 	struct ipv6_addr *ia;
 
-	if (ifp->carrier == LINK_DOWN)
-		return NULL;
-
-	state = IPV6_STATE(ifp);
-	if (state == NULL)
-		return NULL;
+	TAILQ_FOREACH(ifp, sifp->ctx->ifaces, next) {
+		if (ifp != sifp && ip6_forwarding(ifp->name) != 1)
+			continue;
 
-	TAILQ_FOREACH(ia, &state->addrs, next) {
-		if (IN6_IS_ADDR_LINKLOCAL(&ia->addr))
+		state = IPV6_STATE(ifp);
+		if (state == NULL)
 			continue;
-		/* Let's be optimistic.
-		 * Any decent OS won't forward or accept traffic
-		 * from/to tentative or detached addresses. */
-		if (!(ia->addr_flags & IN6_IFF_DUPLICATED))
-			break;
+
+		TAILQ_FOREACH(ia, &state->addrs, next) {
+			if (IN6_IS_ADDR_LINKLOCAL(&ia->addr))
+				continue;
+			/* Let's be optimistic.
+			 * Any decent OS won't forward or accept traffic
+			 * from/to tentative or detached addresses. */
+			if (!(ia->addr_flags & IN6_IFF_DUPLICATED))
+				return ia;
+		}
 	}
-	return ia;
+	return NULL;
 }
 
 void
@@ -1133,7 +1136,7 @@ ipv6_handleifa(struct dhcpcd_ctx *ctx,
 		return;
 	if ((state = ipv6_getstate(ifp)) == NULL)
 		return;
-	anyglobal = ipv6_ifanyglobal(ifp) != NULL;
+	anyglobal = ipv6_anyglobal(ifp) != NULL;
 
 	TAILQ_FOREACH(ia, &state->addrs, next) {
 		if (IN6_ARE_ADDR_EQUAL(&ia->addr, addr))
@@ -1252,7 +1255,7 @@ out:
 	 * call rt_build to add/remove the default route. */
 	if (ifp->active && ifp->options->options & DHCPCD_IPV6 &&
 	    !(ctx->options & DHCPCD_RTBUILD) &&
-	    (ipv6_ifanyglobal(ifp) != NULL) != anyglobal)
+	    (ipv6_anyglobal(ifp) != NULL) != anyglobal)
 		rt_build(ctx, AF_INET6);
 }
 
@@ -2335,7 +2338,7 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 		}
 		if (rap->lifetime == 0)
 			continue;
-		if (ipv6_ifanyglobal(rap->iface) == NULL)
+		if (ipv6_anyglobal(rap->iface) == NULL)
 			continue;
 		rt = inet6_makerouter(rap);
 		if (rt == NULL)