int bt_mesh_trans_recv()

in nimble/host/mesh/src/transport.c [1549:1626]

• 53 lines of code
• 16 McCabe index (conditional complexity)

int bt_mesh_trans_recv(struct os_mbuf *buf, struct bt_mesh_net_rx *rx)
{
	uint64_t seq_auth = TRANS_SEQ_AUTH_NVAL;
	enum bt_mesh_friend_pdu_type pdu_type = BT_MESH_FRIEND_PDU_SINGLE;
	struct net_buf_simple_state state;
	uint8_t seg_count = 0;
	int err;

	if (IS_ENABLED(CONFIG_BT_MESH_FRIEND)) {
		rx->friend_match = bt_mesh_friend_match(rx->sub->net_idx,
							rx->ctx.recv_dst);
	} else {
		rx->friend_match = false;
	}

	BT_DBG("src 0x%04x dst 0x%04x seq 0x%08x friend_match %u",
	       rx->ctx.addr, rx->ctx.recv_dst, (unsigned) rx->seq,
	       rx->friend_match);

	/* Remove network headers */
	net_buf_simple_pull(buf, BT_MESH_NET_HDR_LEN);

	BT_DBG("Payload %s", bt_hex(buf->om_data, buf->om_len));

	if (IS_ENABLED(CONFIG_BT_TESTING)) {
		bt_test_mesh_net_recv(rx->ctx.recv_ttl, rx->ctl, rx->ctx.addr,
				      rx->ctx.recv_dst, buf->om_data, buf->om_len);
	}

	/* If LPN mode is enabled messages are only accepted when we've
	 * requested the Friend to send them. The messages must also
	 * be encrypted using the Friend Credentials.
	 */
	if ((MYNEWT_VAL(BLE_MESH_LOW_POWER)) &&
	    bt_mesh_lpn_established() && rx->net_if == BT_MESH_NET_IF_ADV &&
	    (!bt_mesh_lpn_waiting_update() || !rx->friend_cred)) {
		BT_WARN("Ignoring unexpected message in Low Power mode");
		return -EAGAIN;
	}

	/* Save the app-level state so the buffer can later be placed in
	 * the Friend Queue.
	 */
	net_buf_simple_save(buf, &state);

	if (SEG(buf->om_data)) {
		/* Segmented messages must match a local element or an
		 * LPN of this Friend.
		 */
		if (!rx->local_match && !rx->friend_match) {
			return 0;
		}

		err = trans_seg(buf, rx, &pdu_type, &seq_auth, &seg_count);
	} else {
		seg_count = 1;
		err = trans_unseg(buf, rx, &seq_auth);
	}

	/* Notify LPN state machine so a Friend Poll will be sent. */
	if (IS_ENABLED(CONFIG_BT_MESH_LOW_POWER)) {
		bt_mesh_lpn_msg_received(rx);
	}

	net_buf_simple_restore(buf, &state);

	if (IS_ENABLED(CONFIG_BT_MESH_FRIEND) && rx->friend_match && !err) {
		if (seq_auth == TRANS_SEQ_AUTH_NVAL) {
			bt_mesh_friend_enqueue_rx(rx, pdu_type, NULL,
						  seg_count, buf);
		} else {
			bt_mesh_friend_enqueue_rx(rx, pdu_type, &seq_auth,
						  seg_count, buf);
		}
	}

	return err;
}