Merge pull request #3272 from authmillenon/ng_ndp/fix/fib_get_next_hop

ng_ndp: fix ng_ndp_get_next_hop() for FIB fix in #3250

sys/net/network_layer/ng_ndp/ng_ndp.c

@@ -415,13 +415,16 @@ kernel_pid_t ng_ndp_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
 #ifdef MODULE_FIB
     size_t next_hop_size;
     uint32_t next_hop_flags = 0;
+    ng_ipv6_addr_t next_hop_actual; /* FIB copies address into this variable */
+
     if ((next_hop_ip == NULL) &&
-        ((fib_get_next_hop(&iface, (uint8_t *)next_hop_ip, &next_hop_size,
+        (fib_get_next_hop(&iface, next_hop_actual.u8, &next_hop_size,
                           &next_hop_flags, (uint8_t *)dst,
-                          sizeof(ng_ipv6_addr_t), 0) < 0) ||
-                          (next_hop_size != sizeof(ng_ipv6_addr_t)))) {
-        next_hop_ip = NULL;
+                          sizeof(ng_ipv6_addr_t), 0) >= 0) &&
+        (next_hop_size == sizeof(ng_ipv6_addr_t))) {
+        next_hop_ip = &next_hop_actual;
     }
+
 #endif
 
     if ((next_hop_ip == NULL)) {            /* no route to host */