Pure Golang NMSG Library

go-nmsg is a pure go implementation of the NMSG container and payload format used by the C nmsg toolkit and library.

Synopsis

import "github.com/farsightsec/go-nmsg"
import "github.com/farsightsec/go-nmsg/nmsg_base"

var r io.Reader
var w io.Writer
...
input := nmsg.NewInput(r, mtu)
output := nmsg.BufferedOutput(w)
output.SetMaxSize(nmsg.MaxContainerSize, 0)

for {
	payload, err := input.Recv()
	if err != nil {
		if nmsg.IsDataError(err) {
			continue
		}
		break
	}
	message := payload.Message()

	switch message.(type) {
	case *nmsg_base.Dnstap:
		// process dnstap
		// write copy to output
		output.Send(payload)
	}
}

output.Close()

Requirements

go-nmsg requires the following open source libraries:

"google.golang.org/protobuf/proto"
"github.com/dnstap/golang-dnstap"

Limitations

go-nmsg can pack and unpack the protobuf structure of an NMSG payload, and the protobuf structure of the data contained in the payload. It does not implement the full functionality of the C libnmsg message modules, such as:

• Advanced field types (e.g., a protobuf []byte as an IP address)
• Generated fields
• Formatting of fields for presentation and JSON output

Applications needing such functionality in go should use the cgo-nmsg package included in this distribution under:

"github.com/farsightsec/go-nmsg/cgo-nmsg"