6lowpan: use short IEEE 802.15.4 addresses for broadcast destination

The IEEE 802.15.4 standard uses the 0xFFFF short address (2 bytes) for message
broadcasting.

Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 8 deletions

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index e7f61de2459a..0eebb960e11d 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -572,21 +572,28 @@ static int lowpan_header_create(struct sk_buff *skb,
          * this isn't implemented in mainline yet, so currently we assign 0xff
          */
         {
+                mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+
                 /* prepare wpan address data */
                 sa.addr_type = IEEE802154_ADDR_LONG;
                 sa.pan_id = 0xff;
-
-                da.addr_type = IEEE802154_ADDR_LONG;
-                da.pan_id = 0xff;
-
-                memcpy(&(da.hwaddr), daddr, 8);
                 memcpy(&(sa.hwaddr), saddr, 8);
 
-                mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+                da.pan_id = 0xff;
+                /*
+                 * if the destination address is the broadcast address, use the
+                 * corresponding short address
+                 */
+                if (lowpan_is_addr_broadcast(daddr)) {
+                        da.addr_type = IEEE802154_ADDR_SHORT;
+                        da.short_addr = IEEE802154_ADDR_BROADCAST;
+                } else {
+                        da.addr_type = IEEE802154_ADDR_LONG;
+                        memcpy(&(da.hwaddr), daddr, 8);
 
-                /* request acknowledgment when possible */
-                if (!lowpan_is_addr_broadcast(daddr))
+                        /* request acknowledgment */
                         mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
+                }
 
                 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
                                 type, (void *)&da, (void *)&sa, skb->len);