增加 macvtap 模式支持

server/handler/link_vtap.go

@@ -0,0 +1,137 @@
+package handler
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	"github.com/bjdgyc/anylink/base"
+	"github.com/bjdgyc/anylink/pkg/utils"
+	"github.com/bjdgyc/anylink/sessdata"
+)
+
+// link vtap
+const vTapPrefix = "lvtap"
+
+type Vtap struct {
+	*os.File
+	ifName string
+}
+
+func (v *Vtap) Close() error {
+	v.File.Close()
+	cmdstr := fmt.Sprintf("ip link del %s", v.ifName)
+	return execCmd([]string{cmdstr})
+}
+
+func checkMacvtap() {
+	_setGateway()
+	_checkTapIp(base.Cfg.Ipv4Master)
+
+	ifName := "anylinkMacvtap"
+	// 加载 macvtap
+	cmdstr0 := fmt.Sprintf("modprobe -i macvtap")
+	// 开启主网卡混杂模式
+	cmdstr1 := fmt.Sprintf("ip link set dev %s promisc on", base.Cfg.Ipv4Master)
+	// 测试 macvtap 功能
+	cmdstr2 := fmt.Sprintf("ip link add link %s name %s type macvtap mode bridge", base.Cfg.Ipv4Master, ifName)
+	cmdstr3 := fmt.Sprintf("ip link del %s", ifName)
+	err := execCmd([]string{cmdstr0, cmdstr1, cmdstr2, cmdstr3})
+	if err != nil {
+		base.Fatal(err)
+	}
+}
+
+// 创建 Macvtap 网卡
+func LinkMacvtap(cSess *sessdata.ConnSession) error {
+	capL := sessdata.IpPool.IpLongMax - sessdata.IpPool.IpLongMin
+	ipN := utils.Ip2long(cSess.IpAddr) % capL
+	ifName := fmt.Sprintf("%s%d", vTapPrefix, ipN)
+
+	cSess.SetIfName(ifName)
+
+	cmdstr1 := fmt.Sprintf("ip link add link %s name %s type macvtap mode bridge", base.Cfg.Ipv4Master, ifName)
+	cmdstr2 := fmt.Sprintf("ip link set dev %s up mtu %d address %s", ifName, cSess.Mtu, cSess.MacHw)
+	err := execCmd([]string{cmdstr1, cmdstr2})
+	if err != nil {
+		base.Error(err)
+		return err
+	}
+	cmdstr3 := fmt.Sprintf("sysctl -w net.ipv6.conf.%s.disable_ipv6=1", ifName)
+	execCmd([]string{cmdstr3})
+
+	return createVtap(cSess, ifName)
+}
+
+func checkIpvtap() {
+
+}
+
+// 创建 Ipvtap 网卡
+func LinkIpvtap(cSess *sessdata.ConnSession) error {
+	return nil
+}
+
+type ifReq struct {
+	Name  [0x10]byte
+	Flags uint16
+	pad   [0x28 - 0x10 - 2]byte
+}
+
+func createVtap(cSess *sessdata.ConnSession, ifName string) error {
+	// 初始化 ifName
+	inf, err := net.InterfaceByName(ifName)
+	if err != nil {
+		base.Error(err)
+		return err
+	}
+
+	tName := fmt.Sprintf("/dev/tap%d", inf.Index)
+
+	var fdInt int
+
+	fdInt, err = syscall.Open(tName, os.O_RDWR|syscall.O_NONBLOCK, 0)
+	if err != nil {
+		return err
+	}
+
+	var flags uint16 = syscall.IFF_TAP | syscall.IFF_NO_PI
+	var req ifReq
+	req.Flags = flags
+
+	_, _, errno := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		uintptr(fdInt),
+		uintptr(syscall.TUNSETIFF),
+		uintptr(unsafe.Pointer(&req)),
+	)
+	if errno != 0 {
+		return os.NewSyscallError("ioctl", errno)
+	}
+
+	file := os.NewFile(uintptr(fdInt), tName)
+	ifce := &Vtap{file, ifName}
+
+	go allTapRead(ifce, cSess)
+	go allTapWrite(ifce, cSess)
+	return nil
+}
+
+// 销毁未关闭的vtap
+func destroyVtap() {
+	its, err := net.Interfaces()
+	if err != nil {
+		base.Error(err)
+		return
+	}
+	for _, v := range its {
+		if strings.HasPrefix(v.Name, vTapPrefix) {
+			// 删除原来的网卡
+			cmdstr := fmt.Sprintf("ip link del %s", v.Name)
+			execCmd([]string{cmdstr})
+		}
+	}
+}