sixlowpan: ignore incoming packets if unconfigured

If there's no IPv6 address configured so far to any interface, 6lowpan should not try to handle incoming packets. This can easily lead to looping packets.
OlegHahm · Sep 10, 2014 · 1125457 · 1125457
1 parent 2dc8ea1
commit 1125457
Show file tree

Hide file tree

Showing 2 changed files with 18 additions and 2 deletions.
diff --git a/sys/net/network_layer/sixlowpan/icmp.c b/sys/net/network_layer/sixlowpan/icmp.c
@@ -1523,7 +1523,10 @@ int ndp_addr_is_on_link(ipv6_addr_t *dest_addr)
     int if_id = -1;
 
     if ((nce = ndp_neighbor_cache_search(dest_addr))) {
+#ifdef DEBUG_ENABLED
+        char addr_str[IPV6_MAX_ADDR_STR_LEN];
         DEBUG("INFO: %s is in nbr cache\n", ipv6_addr_to_str(addr_str, IPV6_MAX_ADDR_STR_LEN, dest_addr));
+#endif
         return 1;
     }
 

diff --git a/sys/net/network_layer/sixlowpan/ip.c b/sys/net/network_layer/sixlowpan/ip.c
@@ -313,6 +313,7 @@ int is_our_address(ipv6_addr_t *addr)
     ipv6_net_if_addr_t *myaddr;
     uint8_t prefix, suffix;
     int if_id = -1;
+    unsigned counter = 0;
 
     DEBUGF("Is this my addres: %s?\n", ipv6_addr_to_str(addr_str, IPV6_MAX_ADDR_STR_LEN, addr));
     while ((if_id = net_if_iter_interfaces(if_id)) >= 0) {
@@ -323,6 +324,7 @@ int is_our_address(ipv6_addr_t *addr)
 
         while ((myaddr = (ipv6_net_if_addr_t *)net_if_iter_addresses(if_id,
                          (net_if_addr_t **) &myaddr)) != NULL) {
+            counter++;
             DEBUGF("\tCompare with: %s?\n", ipv6_addr_to_str(addr_str, IPV6_MAX_ADDR_STR_LEN, (ipv6_addr_t*) myaddr->addr_data));
             if ((ipv6_get_addr_match(myaddr->addr_data, addr) >= net_if_ext->prefix) &&
                 (memcmp(&addr->uint8[prefix], &myaddr->addr_data->uint8[prefix], suffix) == 0)) {
@@ -331,7 +333,11 @@ int is_our_address(ipv6_addr_t *addr)
         }
     }
 
-    return 0;
+    if (!counter) {
+        counter = -1;
+    }
+    /* return negative value if no address is configured so far */
+    return counter;
 }
 
 void *ipv6_process(void *arg)
@@ -362,8 +368,15 @@ void *ipv6_process(void *arg)
             }
         }
 
+        int addr_match = is_our_address(&ipv6_buf->destaddr);
+
+        /* no address configured for this node so far, exit early */
+        if (addr_match < 1) {
+            msg_reply(&m_recv_lowpan, &m_send_lowpan);
+            continue;
+        }
         /* destination is our address */
-        if (is_our_address(&ipv6_buf->destaddr)) {
+        else if (addr_match) {
             switch (*nextheader) {
                 case (IPV6_PROTO_NUM_ICMPV6): {
                     icmp_buf = get_icmpv6_buf(ipv6_ext_hdr_len);