Chip Boling | 934e105 | 2021-09-27 15:12:06 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2018 - present. Boling Consulting Solutions (bcsw.net) |
| 3 | * Copyright 2020-present Open Networking Foundation |
| 4 | |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain 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, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | package omci |
| 19 | |
| 20 | import ( |
| 21 | "fmt" |
| 22 | "github.com/google/gopacket" |
| 23 | "github.com/google/gopacket/layers" |
| 24 | me "github.com/opencord/omci-lib-go/generated" |
| 25 | ) |
| 26 | |
| 27 | type UnknownAttributeInfo struct { |
| 28 | EntityClass me.ClassID |
| 29 | EntityInstance uint16 |
| 30 | AttributeMask uint16 |
| 31 | AttributeData []byte |
| 32 | } |
| 33 | type UnknownAttributes struct { |
| 34 | // Each Attributes entry relates one or more unknown attributes to a specific managed |
| 35 | // entity. For message types such as MIB Upload Next responses, there may be multiple |
| 36 | // Managed Entities in a single response if the Extended Message set is being used. |
| 37 | Attributes []UnknownAttributeInfo |
| 38 | |
| 39 | gopacket.Layer |
| 40 | layers.BaseLayer |
| 41 | MsgLayerType gopacket.LayerType |
| 42 | } |
| 43 | |
| 44 | // SerializeTo provides serialization of an Get Next Message Type Response |
| 45 | func (msg *UnknownAttributes) String() string { |
| 46 | return fmt.Sprintf("Unknown Attributes, %v Managed Entities", len(msg.Attributes)) |
| 47 | } |
| 48 | |
| 49 | // LayerType returns LayerTypeGetNextResponse |
| 50 | func (msg *UnknownAttributes) LayerType() gopacket.LayerType { |
| 51 | return LayerTypeUnknownAttributes |
| 52 | } |
| 53 | |
| 54 | // CanDecode returns the set of layer types that this DecodingLayer can decode |
| 55 | func (msg *UnknownAttributes) CanDecode() gopacket.LayerClass { |
| 56 | return LayerTypeUnknownAttributes |
| 57 | } |
| 58 | |
| 59 | // LayerContents returns the bytes of the packet layer. |
| 60 | func (msg *UnknownAttributes) LayerContents() []byte { |
| 61 | return msg.Contents |
| 62 | } |
| 63 | |
| 64 | // LayerPayload returns the bytes contained within the packet layer |
| 65 | func (msg *UnknownAttributes) LayerPayload() []byte { |
| 66 | return msg.Payload |
| 67 | } |
| 68 | |
| 69 | // NextLayerType returns the layer type contained by this DecodingLayer. |
| 70 | func (msg *UnknownAttributes) NextLayerType() gopacket.LayerType { |
| 71 | return gopacket.LayerTypeZero |
| 72 | } |
| 73 | |
| 74 | // DecodeFromBytes decodes the given bytes of a Get Next Response into this layer |
| 75 | func (msg *UnknownAttributes) DecodeFromBytes(_ []byte, _ gopacket.PacketBuilder) error { |
| 76 | // This is not a real layer. It is used to pass on relaxed decode error information |
| 77 | // as an ErrorLayer |
| 78 | return fmt.Errorf("This function is never called. This is an error layer that gets assigned") |
| 79 | } |
| 80 | |
| 81 | func decodeUnknownAttributes(_ []byte, _ gopacket.PacketBuilder) error { |
| 82 | return fmt.Errorf("This function is never called. This is an error layer that gets assigned") |
| 83 | } |
| 84 | |
| 85 | func (msg *UnknownAttributes) Error() error { |
| 86 | return fmt.Errorf("%v managed entities with Unknown Attributes detected during decode", |
| 87 | len(msg.Attributes)) |
| 88 | } |
| 89 | |
| 90 | func newUnknownAttributesLayer(prevLayer gopacket.Layer, errInfo []me.IRelaxedDecodeError, p gopacket.PacketBuilder) error { |
| 91 | // Add the previous layer |
| 92 | p.AddLayer(prevLayer) |
| 93 | |
| 94 | // Append unknown attributes layer and also set ErrorLayer |
| 95 | |
| 96 | errLayer := &UnknownAttributes{ |
| 97 | Attributes: make([]UnknownAttributeInfo, 0), |
| 98 | MsgLayerType: LayerTypeUnknownAttributes, |
| 99 | } |
| 100 | for _, item := range errInfo { |
| 101 | unknown, ok := item.(*me.UnknownAttributeDecodeError) |
| 102 | if !ok { |
| 103 | return fmt.Errorf("only UnknownAttributeDecodeError information can be encoded. Found %T", |
| 104 | unknown) |
| 105 | } |
| 106 | data := UnknownAttributeInfo{ |
| 107 | EntityClass: unknown.EntityClass, |
| 108 | EntityInstance: unknown.EntityInstance, |
| 109 | AttributeMask: unknown.AttributeMask, |
| 110 | } |
| 111 | if unknown.Contents != nil { |
| 112 | data.AttributeData = make([]byte, len(unknown.Contents)) |
| 113 | copy(data.AttributeData, unknown.Contents) |
| 114 | } |
| 115 | errLayer.Attributes = append(errLayer.Attributes, data) |
| 116 | } |
| 117 | p.AddLayer(errLayer) |
| 118 | p.SetErrorLayer(errLayer) |
| 119 | |
| 120 | // Return a valid error so that packet decoding stops |
| 121 | return errLayer.Error() |
| 122 | } |