int drbd_adm_connect()

in drbd/drbd_nl.c [2561:2709]

• 121 lines of code
• 18 McCabe index (conditional complexity)

int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
{
	struct connection_info connection_info;
	enum drbd_notification_type flags;
	unsigned int peer_devices = 0;
	struct drbd_config_context adm_ctx;
	struct drbd_peer_device *peer_device;
	struct net_conf *old_net_conf, *new_net_conf = NULL;
	struct crypto crypto = { };
	struct drbd_resource *resource;
	struct drbd_connection *connection;
	enum drbd_ret_code retcode;
	int i;
	int err;

	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);

	if (!adm_ctx.reply_skb)
		return retcode;
	if (retcode != NO_ERROR)
		goto out;
	if (!(adm_ctx.my_addr && adm_ctx.peer_addr)) {
		drbd_msg_put_info(adm_ctx.reply_skb, "connection endpoint(s) missing");
		retcode = ERR_INVALID_REQUEST;
		goto out;
	}

	/* No need for _rcu here. All reconfiguration is
	 * strictly serialized on genl_lock(). We are protected against
	 * concurrent reconfiguration/addition/deletion */
	for_each_resource(resource, &drbd_resources) {
		for_each_connection(connection, resource) {
			if (nla_len(adm_ctx.my_addr) == connection->my_addr_len &&
			    !memcmp(nla_data(adm_ctx.my_addr), &connection->my_addr,
				    connection->my_addr_len)) {
				retcode = ERR_LOCAL_ADDR;
				goto out;
			}

			if (nla_len(adm_ctx.peer_addr) == connection->peer_addr_len &&
			    !memcmp(nla_data(adm_ctx.peer_addr), &connection->peer_addr,
				    connection->peer_addr_len)) {
				retcode = ERR_PEER_ADDR;
				goto out;
			}
		}
	}

	mutex_lock(&adm_ctx.resource->adm_mutex);
	connection = first_connection(adm_ctx.resource);
	conn_reconfig_start(connection);

	if (connection->cstate > C_STANDALONE) {
		retcode = ERR_NET_CONFIGURED;
		goto fail;
	}

	/* allocation not in the IO path, drbdsetup / netlink process context */
	new_net_conf = kzalloc(sizeof(*new_net_conf), GFP_KERNEL);
	if (!new_net_conf) {
		retcode = ERR_NOMEM;
		goto fail;
	}

	set_net_conf_defaults(new_net_conf);

	err = net_conf_from_attrs(new_net_conf, info);
	if (err && err != -ENOMSG) {
		retcode = ERR_MANDATORY_TAG;
		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
		goto fail;
	}

	retcode = check_net_options(connection, new_net_conf);
	if (retcode != NO_ERROR)
		goto fail;

	retcode = alloc_crypto(&crypto, new_net_conf);
	if (retcode != NO_ERROR)
		goto fail;

	((char *)new_net_conf->shared_secret)[SHARED_SECRET_MAX-1] = 0;

	drbd_flush_workqueue(&connection->sender_work);

	mutex_lock(&adm_ctx.resource->conf_update);
	old_net_conf = connection->net_conf;
	if (old_net_conf) {
		retcode = ERR_NET_CONFIGURED;
		mutex_unlock(&adm_ctx.resource->conf_update);
		goto fail;
	}
	rcu_assign_pointer(connection->net_conf, new_net_conf);

	conn_free_crypto(connection);
	connection->cram_hmac_tfm = crypto.cram_hmac_tfm;
	connection->integrity_tfm = crypto.integrity_tfm;
	connection->csums_tfm = crypto.csums_tfm;
	connection->verify_tfm = crypto.verify_tfm;

	connection->my_addr_len = nla_len(adm_ctx.my_addr);
	memcpy(&connection->my_addr, nla_data(adm_ctx.my_addr), connection->my_addr_len);
	connection->peer_addr_len = nla_len(adm_ctx.peer_addr);
	memcpy(&connection->peer_addr, nla_data(adm_ctx.peer_addr), connection->peer_addr_len);

	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
		peer_devices++;
	}

	connection_to_info(&connection_info, connection);
	flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
	mutex_lock(&notification_mutex);
	notify_connection_state(NULL, 0, connection, &connection_info, NOTIFY_CREATE | flags);
	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
		struct peer_device_info peer_device_info;

		peer_device_to_info(&peer_device_info, peer_device);
		flags = (peer_devices--) ? NOTIFY_CONTINUES : 0;
		notify_peer_device_state(NULL, 0, peer_device, &peer_device_info, NOTIFY_CREATE | flags);
	}
	mutex_unlock(&notification_mutex);
	mutex_unlock(&adm_ctx.resource->conf_update);

	rcu_read_lock();
	idr_for_each_entry(&connection->peer_devices, peer_device, i) {
		struct drbd_device *device = peer_device->device;
		device->send_cnt = 0;
		device->recv_cnt = 0;
	}
	rcu_read_unlock();

	retcode = (enum drbd_ret_code)conn_request_state(connection,
					NS(conn, C_UNCONNECTED), CS_VERBOSE);

	conn_reconfig_done(connection);
	mutex_unlock(&adm_ctx.resource->adm_mutex);
	drbd_adm_finish(&adm_ctx, info, retcode);
	return 0;

fail:
	free_crypto(&crypto);
	kfree(new_net_conf);

	conn_reconfig_done(connection);
	mutex_unlock(&adm_ctx.resource->adm_mutex);
out:
	drbd_adm_finish(&adm_ctx, info, retcode);
	return 0;
}