完善主程序

lower/nic.go

@@ -0,0 +1,109 @@
+package lower
+
+import (
+	"os"
+	"os/exec"
+
+	"github.com/sirupsen/logrus"
+	"github.com/songgao/water"
+	"github.com/songgao/water/waterutil"
+
+	"github.com/fumiama/WireGold/gold/head"
+	"github.com/fumiama/WireGold/gold/link"
+)
+
+// NIC 虚拟网卡
+type NIC struct {
+	ifce     *water.Interface
+	ip       string
+	subnet   string
+	hasstart bool
+}
+
+// NewNIC 新建 TUN 网络接口卡
+// 网卡地址为 ip, 所属子网为 subnet
+func NewNIC(ip, subnet string) (n *NIC) {
+	ifce, err := water.New(water.Config{DeviceType: water.TUN})
+	if err != nil {
+		panic(err)
+	}
+	n = &NIC{
+		ifce:   ifce,
+		ip:     ip,
+		subnet: subnet,
+	}
+	n.prepare()
+	return
+}
+
+// Start 开始处理网卡消息，阻塞
+func (nc *NIC) Start(m *link.Me) {
+	if nc.hasstart {
+		return
+	}
+	nc.hasstart = true
+	go func() { // 接收到 NIC
+		for nc.hasstart {
+			packet := m.Read()
+			logrus.Infoln("[lower] recv", len(packet.Data), "bytes packet")
+			if !waterutil.IsIPv4(packet.Data) {
+				logrus.Warnln("[lower] recv recv non-ipv4 packet")
+				continue
+			}
+			_, err := nc.ifce.Write(packet.Data)
+			if err != nil {
+				logrus.Errorln("[lower] recv write to nic err:", err)
+				break
+			}
+		}
+	}()
+	buf := make([]byte, 4096)
+	for nc.hasstart { // 从 NIC 发送
+		packet := buf
+		n, err := nc.ifce.Read(packet)
+		if err != nil {
+			logrus.Errorln("[lower] send read from nic err:", err)
+			break
+		}
+		if n == 0 {
+			continue
+		}
+		packet = packet[:n]
+		if !waterutil.IsIPv4(packet) {
+			logrus.Warnln("[lower] send recv non-ipv4 packet")
+			continue
+		}
+		logrus.Infoln("[lower] send", n, "bytes packet")
+		dst := waterutil.IPv4Destination(packet)
+		srcport := waterutil.IPv4SourcePort(packet)
+		dstport := waterutil.IPv4DestinationPort(packet)
+		lnk, err := m.Connect(dst.String())
+		if err != nil {
+			logrus.Errorln("[lower] connect to peer err:", err)
+			continue
+		}
+		lnk.Write(head.NewPacket(head.ProtoData, srcport, dstport, packet))
+	}
+}
+
+// Stop 停止处理
+func (n *NIC) Stop() {
+	n.hasstart = false
+}
+
+// Destroy 关闭网卡
+func (n *NIC) Destroy() error {
+	return n.ifce.Close()
+}
+
+func execute(c string, args ...string) {
+	logrus.Printf("[lower] exec cmd: %v %v:", c, args)
+	cmd := exec.Command(c, args...)
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	cmd.Stdin = os.Stdin
+	err := cmd.Run()
+	if err != nil {
+		logrus.Panicln("[lower] failed to exec cmd:", err)
+	}
+}

lower/tun_darwin.go

@@ -0,0 +1,17 @@
+//go:build darwin
+// +build darwin
+
+package lower
+
+func (n *NIC) prepare() {
+	execute("ifconfig", n.ifce.Name(), "inet", n.ip, n.ip, "up")
+	execute("route", "add", n.subnet, "-interface", n.ifce.Name())
+}
+
+func (n *NIC) Up() {
+	execute("ifconfig", n.ifce.Name(), "inet", n.ip, n.ip, "up")
+}
+
+func (n *NIC) Down() {
+	execute("ifconfig", n.ifce.Name(), "down")
+}

lower/tun_linux.go

@@ -0,0 +1,18 @@
+//go:build linux
+// +build linux
+
+package lower
+
+func (n *NIC) prepare() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "mtu", "1500")
+	execute("/sbin/ip", "addr", "add", ip, "dev", ifcename)
+	execute("/sbin/ip", "route", "add", subnet, "dev", ifcename)
+}
+
+func (n *NIC) Up() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "up")
+}
+
+func (n *NIC) Down() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "down")
+}

lower/tun_stub.go

@@ -0,0 +1,16 @@
+//go:build !darwin && !linux && !windows
+// +build !darwin,!linux,!windows
+
+package lower
+
+func (n *NIC) prepare() {
+	panic("not support this os now")
+}
+
+func (n *NIC) Up() {
+	panic("not support this os now")
+}
+
+func (n *NIC) Down() {
+	panic("not support this os now")
+}

lower/tun_windows.go

@@ -0,0 +1,18 @@
+//go:build windows
+// +build windows
+
+package lower
+
+func (n *NIC) prepare() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "mtu", "1500")
+	execute("/sbin/ip", "addr", "add", ip, "dev", ifcename)
+	execute("/sbin/ip", "route", "add", subnet, "dev", ifcename)
+}
+
+func (n *NIC) Up() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "up")
+}
+
+func (n *NIC) Down() {
+	execute("/sbin/ip", "link", "set", "dev", ifcename, "down")
+}