dissertation-2-code/config/builder.go

package config

import (
	"fmt"
	"mpbl3p/proxy"
	"mpbl3p/tcp"
	"mpbl3p/tun"
)

// TODO: Delete this code as soon as an alternative is available
type UselessMac struct{}

func (UselessMac) CodeLength() int {
	return 0
}

func (UselessMac) Generate([]byte) []byte {
	return nil
}

func (u UselessMac) Verify([]byte, []byte) error {
	return nil
}

func (c Configuration) Build() (*proxy.Proxy, error) {
	p := proxy.Proxy{}
	p.Generator = UselessMac{}

	ss, err := tun.NewTun("nc%d", 1500)
	if err != nil {
		return nil, err
	}

	p.Source = ss
	p.Sink = ss

	for _, peer := range c.Peers {
		p.Verifiers = append(p.Verifiers, UselessMac{})

		switch peer.Method {
		case "TCP":
			prod, cons, err := buildTcp(peer)
			if err != nil {
				return nil, err
			}
			p.Producers = append(p.Producers, prod)
			p.Consumers = append(p.Consumers, cons)
		}
	}

	return &p, nil
}

func buildTcp(p Peer) (proxy.Producer, proxy.Consumer, error) {
	if p.RemoteHost != "" {
		f, err := tcp.NewFlow(
			fmt.Sprintf("%s:", p.LocalHost),
			fmt.Sprintf("%s:%d", p.RemoteHost, p.RemotePort),
		)

		if err != nil {
			return nil, nil, err
		}

		return &f, &f, nil
	}

	r, err := tcp.NewReceiver(fmt.Sprintf("%s:%d", p.LocalHost, p.LocalPort))
	if err != nil {
		return nil, nil, err
	}

	return r, r, nil
}