org.onosproject.openflow.controller.driver.RoleHandler Maven / Gradle / Ivy
/*
* Copyright 2014 Open Networking Laboratory
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.onosproject.openflow.controller.driver;
import java.io.IOException;
import org.onosproject.openflow.controller.RoleState;
import org.projectfloodlight.openflow.protocol.OFErrorMsg;
import org.projectfloodlight.openflow.protocol.OFExperimenter;
import org.projectfloodlight.openflow.protocol.OFRoleReply;
/**
* Role handling.
*
*/
public interface RoleHandler {
/**
* Extract the role from an OFVendor message.
*
* Extract the role from an OFVendor message if the message is a
* Nicira role reply. Otherwise return null.
*
* @param experimenterMsg The vendor message to parse.
* @return The role in the message if the message is a Nicira role
* reply, null otherwise.
* @throws SwitchStateException If the message is a Nicira role reply
* but the numeric role value is unknown.
*/
RoleState extractNiciraRoleReply(OFExperimenter experimenterMsg)
throws SwitchStateException;
/**
* Send a role request with the given role to the switch and update
* the pending request and timestamp.
* Sends an OFPT_ROLE_REQUEST to an OF1.3 switch, OR
* Sends an NX_ROLE_REQUEST to an OF1.0 switch if configured to support it
* in the IOFSwitch driver. If not supported, this method sends nothing
* and returns 'false'. The caller should take appropriate action.
*
* One other optimization we do here is that for OF1.0 switches with
* Nicira role message support, we force the Role.EQUAL to become
* Role.SLAVE, as there is no defined behavior for the Nicira role OTHER.
* We cannot expect it to behave like SLAVE. We don't have this problem with
* OF1.3 switches, because Role.EQUAL is well defined and we can simulate
* SLAVE behavior by using ASYNC messages.
*
* @param role role to request
* @param exp expectation
* @throws IOException when I/O exception of some sort has occurred
* @return false if and only if the switch does not support role-request
* messages, according to the switch driver; true otherwise.
*/
boolean sendRoleRequest(RoleState role, RoleRecvStatus exp)
throws IOException;
/**
* Extract the role information from an OF1.3 Role Reply Message.
* @param rrmsg role reply message
* @return RoleReplyInfo object
* @throws SwitchStateException If unknown role encountered
*/
RoleReplyInfo extractOFRoleReply(OFRoleReply rrmsg)
throws SwitchStateException;
/**
* Deliver a received role reply.
*
* Check if a request is pending and if the received reply matches the
* the expected pending reply (we check both role and xid) we set
* the role for the switch/channel.
*
* If a request is pending but doesn't match the reply we ignore it, and
* return
*
* If no request is pending we disconnect with a SwitchStateException
*
* @param rri information about role-reply in format that
* controller can understand.
* @return result comparing expected and received reply
* @throws SwitchStateException if no request is pending
*/
RoleRecvStatus deliverRoleReply(RoleReplyInfo rri)
throws SwitchStateException;
/**
* Called if we receive an error message. If the xid matches the
* pending request we handle it otherwise we ignore it.
*
* Note: since we only keep the last pending request we might get
* error messages for earlier role requests that we won't be able
* to handle
* @param error error message
* @return result comparing expected and received reply
* @throws SwitchStateException if switch did not support requested role
*/
RoleRecvStatus deliverError(OFErrorMsg error)
throws SwitchStateException;
}