fixup! opendsme: add initial support

pkg/opendsme/contrib/opendsme.cpp

@@ -25,12 +25,24 @@ static bool _pan_coord;
 extern void heap_stats(void);
 static int _send(gnrc_netif_t *netif, gnrc_pktsnip_t *pkt)
 {
-    /* TODO */
-    uint8_t addr[IEEE802154_SHORT_ADDRESS_LEN];
+    /* Note that there the short address is assigned by the coordinator and the
+     * user should not have control over it.
+     * Given that, and the fact the current MAC does not communicate with
+     * different PANs, we can always use the short address */
+    uint8_t *addr;
     gnrc_netif_hdr_t *hdr = (gnrc_netif_hdr_t*) pkt->data;
-    memcpy(addr, gnrc_netif_hdr_get_dst_addr(hdr), IEEE802154_SHORT_ADDRESS_LEN);
-    pkt = gnrc_pktbuf_remove_snip(pkt, pkt);
+    if (hdr->dst_l2addr_len == IEEE802154_LONG_ADDRESS_LEN) {
+        addr = gnrc_netif_hdr_get_dst_addr(hdr)
+               + IEEE802154_LONG_ADDRESS_LEN
+               - IEEE802154_SHORT_ADDRESS_LEN;
+    }
+    else {
+        assert(hdr->dst_l2addr_len == IEEE802154_SHORT_ADDRESS_LEN);
+        addr = gnrc_netif_hdr_get_dst_addr(hdr);
+    }
+
     uint16_t _addr = byteorder_ntohs(*((network_uint16_t*) addr));
+    pkt = gnrc_pktbuf_remove_snip(pkt, pkt);
     m_dsme.sendFrame(_addr, (iolist_t*) pkt);
 
     return 0;