55 lines
1.4 KiB
Go
55 lines
1.4 KiB
Go
/*
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Copyright 2024 Josh Deprez
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package aep
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import "fmt"
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type Function uint8
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const (
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EchoRequest Function = 1
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EchoReply Function = 2
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)
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// Packet represents an AEP packet.
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type Packet struct {
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Function Function
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Data []byte
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}
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// Marshal marshals an AEP packet.
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func (p *Packet) Marshal() ([]byte, error) {
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if p.Function < 1 || p.Function > 2 {
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return nil, fmt.Errorf("invalid AEP function %d", p.Function)
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}
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if len(p.Data) == 0 {
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return nil, fmt.Errorf("empty AEP packet")
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}
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return append([]byte{byte(p.Function)}, p.Data...), nil
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}
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// Unmarshal unmarshals an AEP packet.
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func Unmarshal(data []byte) (*Packet, error) {
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if len(data) < 1 {
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return nil, fmt.Errorf("insufficient input length %d for AEP packet", len(data))
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}
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return &Packet{
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Function: Function(data[0]),
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Data: data[1:],
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}, nil
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}
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