jrouter/atalk/aep/aep.go
2024-04-08 09:21:35 +10:00

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
}