Sielink protocol library

Package sielink implements the protocol used for communication between SIE sensors and submission servers, as well for coordination between submission servers.

It contains two subdirectories:

• rawlink, the core implementation of the Sielink 'Link' protocol, and
• client, a profile of the Sielink protocol suitable for a sensor.

The client library supports both publication and subscription through the Sielink protocol.

Requirements

sielink relies on the following two go libraries:

• github.com/golang/protobuf/proto
• golang.org/x/net/websocket

Client Usage

First, set up a new client with:

    import "github.com/farsightsec/sielink/client"

    cli := client.NewClient(&client.Config{
            Heartbeat: time.Minute,
            // The URL is required, and must be a valid URL,
            // but is otherwise unused by sielink.
            URL:       "https://localhost/my-submit-app",
            APIKey:    apiKeyString,
    })

then open one or more connections to submission servers with:

    err := cli.DialAndHandle("wss://<server>/session/<sessionName>")

DialAndHandle only returns when the connection closes, so this should be run in a retry loop on a separate goroutine.

Submitting data

Data submitted to the submission service must be enclosed in a *sielink.Payload, and tagged with a data type (sielink only supports NMSG container data as of this writing) and channel.

    import (
            "github.com/golang/protobuf/proto"
            "github.com/farsightsec/sielink"
    )

    err := cli.Send(&sielink.Payload{
            Channel: proto.Uint32(channelNumber),
            PayloadType: sielink.PayloadType_NmsgContainer.Enum(),
            Data: data, // []byte, serialized NMSG container
    })

Subscribing to data

The sielink/client package also allows subscribing to data, with:

    cli.Subscribe(channel1, channel2, ...)

    for p := range cli.Receive() {
            if p.PayloadType != sielink.PayloadType_NmsgContainer {
                    continue
            }
            processNmsgContainer(p.GetData())
    }