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mirror of https://github.com/wader/fq.git synced 2024-12-25 14:23:18 +03:00
fq/format/inet/ether8023_frame.go
Mattias Wadman 9133f0e527 scalar: Add *Fn type to map value and clearer naming
Should replace most of this with generics at some point
2022-05-07 12:46:34 +02:00

57 lines
1.4 KiB
Go

package inet
// TODO: move to own package?
import (
"encoding/binary"
"fmt"
"github.com/wader/fq/format"
"github.com/wader/fq/format/registry"
"github.com/wader/fq/pkg/decode"
"github.com/wader/fq/pkg/scalar"
)
var ether8023FrameInetPacketGroup decode.Group
func init() {
registry.MustRegister(decode.Format{
Name: format.ETHER8023_FRAME,
Description: "Ethernet 802.3 frame",
Groups: []string{format.LINK_FRAME},
Dependencies: []decode.Dependency{
{Names: []string{format.INET_PACKET}, Group: &ether8023FrameInetPacketGroup},
},
DecodeFn: decodeEthernetFrame,
})
}
// TODO: move to shared?
var mapUToEtherSym = scalar.Fn(func(s scalar.S) (scalar.S, error) {
var b [8]byte
binary.BigEndian.PutUint64(b[:], s.ActualU())
s.Sym = fmt.Sprintf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", b[2], b[3], b[4], b[5], b[6], b[7])
return s, nil
})
func decodeEthernetFrame(d *decode.D, in interface{}) interface{} {
if lfi, ok := in.(format.LinkFrameIn); ok {
if lfi.Type != format.LinkTypeETHERNET {
d.Fatalf("wrong link type %d", lfi.Type)
}
}
d.FieldU("destination", 48, mapUToEtherSym, scalar.ActualHex)
d.FieldU("source", 48, mapUToEtherSym, scalar.ActualHex)
etherType := d.FieldU16("ether_type", format.EtherTypeMap, scalar.ActualHex)
d.FieldFormatOrRawLen(
"payload",
d.BitsLeft(),
ether8023FrameInetPacketGroup,
format.InetPacketIn{EtherType: int(etherType)},
)
return nil
}