int bt_mesh_friend_req()

in nimble/host/mesh/src/friend.c [956:1058]

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

int bt_mesh_friend_req(struct bt_mesh_net_rx *rx, struct os_mbuf *buf)
{
	struct bt_mesh_ctl_friend_req *msg = (void *)buf->om_data;
	struct bt_mesh_friend *frnd = NULL;
	uint32_t poll_to;
	int32_t delay;
	int i, err;

	if (rx->net_if == BT_MESH_NET_IF_LOCAL) {
		BT_WARN("Ignoring Friend request from local interface");
		return 0;
	}

	if (buf->om_len < sizeof(*msg)) {
		BT_WARN("Too short Friend Request");
		return -EINVAL;
	}

	if (msg->recv_delay <= 0x09) {
		BT_WARN("Prohibited ReceiveDelay (0x%02x)", msg->recv_delay);
		return -EINVAL;
	}

	poll_to = sys_get_be24(msg->poll_to);

	if (poll_to <= 0x000009 || poll_to >= 0x34bc00) {
		BT_WARN("Prohibited PollTimeout (0x%06x)", (unsigned) poll_to);
		return -EINVAL;
	}

	if (msg->num_elem == 0x00) {
		BT_WARN("Prohibited NumElements value (0x00)");
		return -EINVAL;
	}

	if (!BT_MESH_ADDR_IS_UNICAST(rx->ctx.addr + msg->num_elem - 1)) {
		BT_WARN("LPN elements stretch outside of unicast range");
		return -EINVAL;
	}

	if (!MIN_QUEUE_SIZE_LOG(msg->criteria)) {
		BT_WARN("Prohibited Minimum Queue Size in Friend Request");
		return -EINVAL;
	}

	if (CONFIG_BT_MESH_FRIEND_QUEUE_SIZE < MIN_QUEUE_SIZE(msg->criteria)) {
		BT_WARN("We have a too small Friend Queue size (%u < %u)",
			CONFIG_BT_MESH_FRIEND_QUEUE_SIZE,
			(unsigned) MIN_QUEUE_SIZE(msg->criteria));
		return 0;
	}

	frnd = bt_mesh_friend_find(rx->sub->net_idx, rx->ctx.addr, true, false);
	if (frnd) {
		BT_WARN("Existing LPN re-requesting Friendship");
		friend_clear(frnd);
		goto init_friend;
	}

	for (i = 0; i < ARRAY_SIZE(bt_mesh.frnd); i++) {
		if (!bt_mesh.frnd[i].subnet) {
			frnd = &bt_mesh.frnd[i];
			break;
		}
	}

	if (!frnd) {
		BT_WARN("No free Friend contexts for new LPN");
		return -ENOMEM;
	}

init_friend:
	frnd->lpn = rx->ctx.addr;
	frnd->num_elem = msg->num_elem;
	frnd->subnet = rx->sub;
	frnd->recv_delay = msg->recv_delay;
	frnd->poll_to = poll_to * 100;
	frnd->lpn_counter = sys_be16_to_cpu(msg->lpn_counter);
	frnd->clear.frnd = sys_be16_to_cpu(msg->prev_addr);

	err = friend_cred_create(frnd, SUBNET_KEY_TX_IDX(frnd->subnet));
	if (err) {
		BT_ERR("Failed to create friend credentials");
		friend_clear(frnd);
		return -EIO;
	}

	BT_DBG("LPN 0x%04x rssi %d recv_delay %u poll_to %ums",
	       frnd->lpn, rx->ctx.recv_rssi, frnd->recv_delay,
	       (unsigned) frnd->poll_to);

	if (BT_MESH_ADDR_IS_UNICAST(frnd->clear.frnd) &&
	    !bt_mesh_has_addr(frnd->clear.frnd)) {
		clear_procedure_start(frnd);
	}

	delay = offer_delay(frnd, rx->ctx.recv_rssi, msg->criteria);
	k_work_reschedule(&frnd->timer, K_MSEC(delay));

	enqueue_offer(frnd, rx->ctx.recv_rssi);

	return 0;
}