54 lines
1.4 KiB
Go
54 lines
1.4 KiB
Go
/*
|
|
Copyright 2024 Josh Deprez
|
|
|
|
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 aep
|
|
|
|
import "fmt"
|
|
|
|
type Function uint8
|
|
|
|
const (
|
|
EchoRequest Function = 1
|
|
EchoReply Function = 2
|
|
)
|
|
|
|
// Packet represents an AEP packet.
|
|
type Packet struct {
|
|
Function Function
|
|
Data []byte
|
|
}
|
|
|
|
// Marshal marshals an AEP packet.
|
|
func (p *Packet) Marshal() ([]byte, error) {
|
|
if p.Function < 1 || p.Function > 2 {
|
|
return nil, fmt.Errorf("invalid AEP function %d", p.Function)
|
|
}
|
|
if len(p.Data) == 0 {
|
|
return nil, fmt.Errorf("empty AEP packet")
|
|
}
|
|
return append([]byte{byte(p.Function)}, p.Data...), nil
|
|
}
|
|
|
|
// Unmarshal unmarshals an AEP packet.
|
|
func Unmarshal(data []byte) (*Packet, error) {
|
|
if len(data) < 1 {
|
|
return nil, fmt.Errorf("insufficient input length %d for AEP packet", len(data))
|
|
}
|
|
return &Packet{
|
|
Function: Function(data[0]),
|
|
Data: data[1:],
|
|
}, nil
|
|
}
|