Initial commit of utilities

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

cmd/ircmirror/net.go

@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2021 Jason A. Donenfeld. All Rights Reserved.
+ */
+
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"log"
+	"net"
+
+	"golang.zx2c4.com/wireguard/conn"
+	"golang.zx2c4.com/wireguard/device"
+	"golang.zx2c4.com/wireguard/tun/netstack"
+)
+
+func makeNet(conf *vpnConf, endpoint vpnEndpoint) (*device.Device, *netstack.Net, error) {
+	var localAddresses, dnsServers []net.IP
+	for _, ip := range conf.ips {
+		localAddresses = append(localAddresses, ip.IPAddr().IP)
+	}
+	for _, ip := range conf.dnses {
+		dnsServers = append(dnsServers, ip.IPAddr().IP)
+	}
+	tun, stack, err := netstack.CreateNetTUN(localAddresses, dnsServers, 1420)
+	if err != nil {
+		return nil, nil, err
+	}
+	logf := func(format string, args ...interface{}) {
+		log.Printf("[NET %s] "+format, append([]interface{}{endpoint.name}, args...)...)
+	}
+	dev := device.NewDevice(tun, conn.NewStdNetBind(), &device.Logger{logf, logf})
+	err = dev.IpcSet(fmt.Sprintf("private_key=%s\npublic_key=%s\nendpoint=%s\nallowed_ip=0.0.0.0/0\nallowed_ip=::/0\n",
+		hex.EncodeToString(conf.privateKey), hex.EncodeToString(endpoint.publicKey), endpoint.endpoint.String()))
+	if err != nil {
+		return nil, nil, err
+	}
+	err = dev.Up()
+	if err != nil {
+		return nil, nil, err
+	}
+	return dev, stack, nil
+}
+
+type dialer struct {
+	name string
+	dial func(network, address string) (net.Conn, error)
+}
+
+func makeDialers(conf *vpnConf, endpoints []vpnEndpoint) (dialers []dialer, err error) {
+	var devs []*device.Device
+	defer func() {
+		if err != nil {
+			for _, dev := range devs {
+				dev.Close()
+			}
+		}
+	}()
+	for _, endpoint := range endpoints {
+		dev, stack, err := makeNet(conf, endpoint)
+		if err != nil {
+			return nil, err
+		}
+		devs = append(devs, dev)
+		dialers = append(dialers, dialer{endpoint.name, stack.Dial})
+	}
+	return dialers, nil
+}
+
+func (d *dialer) splitByAf() (v4, v6 func(network, address string) (net.Conn, error)) {
+	return func(network, address string) (net.Conn, error) {
+			if len(network) == 3 {
+				network += "4"
+			}
+			return d.dial(network, address)
+		}, func(network, address string) (net.Conn, error) {
+			if len(network) == 3 {
+				network += "6"
+			}
+			return d.dial(network, address)
+		}
+}