net: l2: ieee802154: add support for IEEE802154_CFI_DATA_REQUEST

The 802.15.4 specifies that a device may send a DATA_REQUEST command to
the coordinator macResponseWaitTime symbols after the acknowledgment to
an association request command.

This change adds proper support to generate DATA_REQUEST frames and
sends one for the association usecase only. The two other usecases, for
MLME-POLL or for beacon-enabled PAN, are not yet supported.

Signed-off-by: Simon Piriou <[email protected]>

Author: spiriou

subsys/net/l2/ieee802154/ieee802154_frame.c

@@ -792,8 +792,37 @@ static inline bool cfi_to_fs_settings(enum ieee802154_cfi cfi, struct ieee802154
 
 		break;
 	case IEEE802154_CFI_DATA_REQUEST:
+		if (params->dst.len == 0) {
+			/* If the Destination Addressing Mode subfield is set to zero (i.e.,
+			 * destination addressing information not present), the PAN ID
+			 * Compression subfield of the Frame Control field shall be set to zero
+			 * and the source PAN identifier shall contain the value of macPANId.
+			 *
+			 * This is the case only if the data request command is being
+			 * sent in response to the receipt of a beacon frame indicating that
+			 * data are pending for that device.
+			 */
+			fs->fc.dst_addr_mode = IEEE802154_ADDR_MODE_NONE;
+		} else {
+			/* Both short and extended dest addresses are supported.
+			 * It's up to the caller to configure it correctly.
+			 */
+			if (params->dst.len == IEEE802154_SHORT_ADDR_LENGTH) {
+				fs->fc.dst_addr_mode = IEEE802154_ADDR_MODE_SHORT;
+			} else {
+				fs->fc.dst_addr_mode = IEEE802154_ADDR_MODE_EXTENDED;
+			}
+			fs->fc.pan_id_comp = 1U;
+		}
+
+		if (params->short_addr == IEEE802154_NO_SHORT_ADDRESS_ASSIGNED) {
+			fs->fc.src_addr_mode = IEEE802154_ADDR_MODE_EXTENDED;
+		} else {
+			fs->fc.dst_addr_mode = IEEE802154_ADDR_MODE_SHORT;
+		}
+
+		/* the Acknowledgment Request subfield is always set */
 		fs->fc.ar = 1U;
-		/* TODO: src/dst addr mode: see section 7.5.5 */
 
 		break;
 	case IEEE802154_CFI_ORPHAN_NOTIFICATION:

subsys/net/l2/ieee802154/ieee802154_mgmt.c

@@ -574,7 +574,30 @@ static int ieee802154_associate(uint64_t mgmt_request, struct net_if *iface,
 	 * TODO: The Association Response command shall be sent to the device
 	 *       requesting association using indirect transmission.
 	 */
-	k_sem_take(&ctx->scan_ctx_lock, K_USEC(ieee802154_get_response_wait_time_us(iface)));
+	ret = k_sem_take(&ctx->scan_ctx_lock, K_USEC(ieee802154_get_response_wait_time_us(iface)));
+
+	if (ret == -EAGAIN) {
+		/* Timeout, send DATA_REQUEST */
+		net_pkt_unref(pkt);
+		pkt = ieee802154_create_mac_cmd_frame(
+				iface, IEEE802154_CFI_DATA_REQUEST, &params);
+		if (!pkt) {
+			ret = -ENOBUFS;
+			k_sem_give(&ctx->scan_ctx_lock);
+			NET_ERR("Could not associate: cannot allocate DATA request frame");
+			goto out;
+		}
+		ieee802154_mac_cmd_finalize(pkt, IEEE802154_CFI_DATA_REQUEST);
+
+		if (ieee802154_radio_send(iface, pkt, pkt->buffer)) {
+			ret = -EIO;
+			k_sem_give(&ctx->scan_ctx_lock);
+			NET_ERR("Could not associate: cannot send DATA request");
+			goto out;
+		}
+
+		k_sem_take(&ctx->scan_ctx_lock, K_USEC(ieee802154_get_response_wait_time_us(iface)));
+	}
 
 	/* Release the scan lock in case an association response was not received
 	 * within macResponseWaitTime and we got a timeout instead.
@@ -607,6 +630,7 @@ static int ieee802154_associate(uint64_t mgmt_request, struct net_if *iface,
 		}
 
 		ctx->channel = req->channel;
+		ret = 0;
 	} else {
 		ret = -EACCES;
 	}