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>

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index e7f61de..0eebb96 100644 (file)
--- 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);