Umesh Krishnaswamy | 345ee99 | 2012-12-13 20:29:48 -0800 | [diff] [blame] | 1 | /** |
| 2 | * Copyright 2011, Big Switch Networks, Inc. |
| 3 | * Originally created by David Erickson & Rob Sherwood, Stanford University |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 6 | * not use this file except in compliance with the License. You may obtain |
| 7 | * a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 13 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 14 | * License for the specific language governing permissions and limitations |
| 15 | * under the License. |
| 16 | **/ |
| 17 | |
| 18 | package org.openflow.protocol.vendor; |
| 19 | |
| 20 | import java.util.HashMap; |
| 21 | import java.util.Map; |
| 22 | |
| 23 | import org.jboss.netty.buffer.ChannelBuffer; |
| 24 | import org.openflow.protocol.Instantiable; |
| 25 | |
| 26 | /** |
| 27 | * Basic subclass of OFVendorId that works with any vendor data format where |
| 28 | * the data begins with an integral data type value. |
| 29 | * |
| 30 | * @author Rob Vaterlaus (rob.vaterlaus@bigswitch.com) |
| 31 | */ |
| 32 | public class OFBasicVendorId extends OFVendorId { |
| 33 | |
| 34 | /** |
| 35 | * The size of the data type value at the beginning of all vendor |
| 36 | * data associated with this vendor id. The data type size must be |
| 37 | * either 1, 2, 4 or 8. |
| 38 | */ |
| 39 | protected int dataTypeSize; |
| 40 | |
| 41 | /** |
| 42 | * Map of the vendor data types that have been registered for this |
| 43 | * vendor id. |
| 44 | */ |
| 45 | protected Map<Long, OFBasicVendorDataType> dataTypeMap = |
| 46 | new HashMap<Long, OFBasicVendorDataType>(); |
| 47 | |
| 48 | /** |
| 49 | * Construct an OFVendorId that where the vendor data begins |
| 50 | * with a data type value whose size is dataTypeSize. |
| 51 | * @param id the id of the vendor, typically the OUI of a vendor |
| 52 | * prefixed with 0. |
| 53 | * @param dataTypeSize the size of the integral data type value |
| 54 | * at the beginning of the vendor data. The value must be the |
| 55 | * size of an integeral data type (i.e. either 1,2,4 or 8). |
| 56 | */ |
| 57 | public OFBasicVendorId(int id, int dataTypeSize) { |
| 58 | super(id); |
| 59 | assert (dataTypeSize == 1) || (dataTypeSize == 2) || |
| 60 | (dataTypeSize == 4) || (dataTypeSize == 8); |
| 61 | this.dataTypeSize = dataTypeSize; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Get the size of the data type value at the beginning of the vendor |
| 66 | * data. OFBasicVendorId assumes that this value is common across all of |
| 67 | * the vendor data formats associated with a given vendor id. |
| 68 | * @return |
| 69 | */ |
| 70 | public int getDataTypeSize() { |
| 71 | return dataTypeSize; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Register a vendor data type with this vendor id. |
| 76 | * @param vendorDataType |
| 77 | */ |
| 78 | public void registerVendorDataType(OFBasicVendorDataType vendorDataType) { |
| 79 | dataTypeMap.put(vendorDataType.getTypeValue(), vendorDataType); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Lookup the OFVendorDataType instance that has been registered with |
| 84 | * this vendor id. |
| 85 | * |
| 86 | * @param vendorDataType the integer code that was parsed from the |
| 87 | * @return |
| 88 | */ |
| 89 | public OFVendorDataType lookupVendorDataType(int vendorDataType) { |
| 90 | return dataTypeMap.get(vendorDataType); |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * This function parses enough of the data from the buffer to be able |
| 95 | * to determine the appropriate OFVendorDataType for the data. It is meant |
| 96 | * to be a reasonably generic implementation that will work for most |
| 97 | * formats of vendor extensions. If the vendor data doesn't fit the |
| 98 | * assumptions listed below, then this method will need to be overridden |
| 99 | * to implement custom parsing. |
| 100 | * |
| 101 | * This implementation assumes that the vendor data begins with a data |
| 102 | * type code that is used to distinguish different formats of vendor |
| 103 | * data associated with a particular vendor ID. |
| 104 | * The exact format of the data is vendor-defined, so we don't know how |
| 105 | * how big the code is (or really even if there is a code). This code |
| 106 | * assumes that the common case will be that the data does include |
| 107 | * an initial type code (i.e. so that the vendor can have multiple |
| 108 | * message/data types) and that the size is either 1, 2 or 4 bytes. |
| 109 | * The size of the initial type code is configured by the subclass of |
| 110 | * OFVendorId. |
| 111 | * |
| 112 | * @param data the channel buffer containing the vendor data. |
| 113 | * @param length the length to the end of the enclosing message |
| 114 | * @return the OFVendorDataType that can be used to instantiate the |
| 115 | * appropriate subclass of OFVendorData. |
| 116 | */ |
| 117 | public OFVendorDataType parseVendorDataType(ChannelBuffer data, int length) { |
| 118 | OFVendorDataType vendorDataType = null; |
| 119 | |
| 120 | // Parse out the type code from the vendor data. |
| 121 | long dataTypeValue = 0; |
| 122 | if ((length == 0) || (length >= dataTypeSize)) { |
| 123 | switch (dataTypeSize) { |
| 124 | case 1: |
| 125 | dataTypeValue = data.readByte(); |
| 126 | break; |
| 127 | case 2: |
| 128 | dataTypeValue = data.readShort(); |
| 129 | break; |
| 130 | case 4: |
| 131 | dataTypeValue = data.readInt(); |
| 132 | break; |
| 133 | case 8: |
| 134 | dataTypeValue = data.readLong(); |
| 135 | break; |
| 136 | default: |
| 137 | // This would be indicative of a coding error where the |
| 138 | // dataTypeSize was specified incorrectly. This should have been |
| 139 | // caught in the constructor for OFVendorId. |
| 140 | assert false; |
| 141 | } |
| 142 | |
| 143 | vendorDataType = dataTypeMap.get(dataTypeValue); |
| 144 | } |
| 145 | |
| 146 | // If we weren't able to parse/map the data to a known OFVendorDataType, |
| 147 | // then map it to a generic vendor data type. |
| 148 | if (vendorDataType == null) { |
| 149 | vendorDataType = new OFBasicVendorDataType(dataTypeValue, |
| 150 | new Instantiable<OFVendorData>() { |
| 151 | @Override |
| 152 | public OFVendorData instantiate() { |
| 153 | return new OFByteArrayVendorData(); |
| 154 | } |
| 155 | } |
| 156 | ); |
| 157 | } |
| 158 | |
| 159 | return vendorDataType; |
| 160 | } |
| 161 | |
| 162 | } |