mirror of
https://github.com/impact-eintr/netstack.git
synced 2025-10-08 06:10:04 +08:00
139 lines
2.8 KiB
Go
139 lines
2.8 KiB
Go
package tuntap
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import (
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"errors"
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"fmt"
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"os/exec"
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"syscall"
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"unsafe"
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)
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const (
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TUN = 1
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TAP = 2
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)
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var (
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ErrDeviceMode = errors.New("unsupport device mode")
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)
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type rawSockaddr struct {
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Family uint16
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Data [14]byte
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}
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type Config struct {
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Name string // 网卡名
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Mode int // 网卡模式 TUN or TAP
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}
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// NewNetDev根据配置返回虚拟网卡的文件描述符
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func NewNetDev(c *Config) (fd int, err error) {
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switch c.Mode {
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case TUN:
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fd, err = newTun(c.Name)
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case TAP:
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fd, err = newTap(c.Name)
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default:
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err = ErrDeviceMode
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return
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}
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if err != nil {
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return
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}
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return
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}
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// TUN 工作在第二层
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func newTun(name string) (int, error) {
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return open(name, syscall.IFF_TUN|syscall.IFF_NO_PI)
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}
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// TAP工作在第三层
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func newTap(name string) (int, error){
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return open(name, syscall.IFF_TAP|syscall.IFF_NO_PI)
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}
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func open(name string, flags uint16) (int, error) {
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// 打开tuntap 设备
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fd, err := syscall.Open("/dev/net/tun", syscall.O_RDWR, 0)
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if err != nil {
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return -1, err
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}
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var ifr struct {
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name [16]byte
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flags uint16
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_ [22]byte
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}
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copy(ifr.name[:], name)
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ifr.flags = flags
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// 通过ioctl系统调用 将fd和虚拟网卡驱动绑定在一起
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_, _ , errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd),
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syscall.TUNSETIFF, uintptr(unsafe.Pointer(&ifr)))
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if errno != 0 {
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syscall.Close(fd)
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return -1, errno
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}
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return fd, nil
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}
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// SetLinkUp 让系统启动该网卡 ip link set tap0 up
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func SetLinkUp(name string) (err error) {
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// ip link set <device-name> up
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out, cmdErr := exec.Command("ip", "link", "set", name, "up").CombinedOutput()
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if cmdErr != nil {
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err = fmt.Errorf("%v:%v", cmdErr, string(out))
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return
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}
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return
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}
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// SetRoute 通过ip命令添加路由
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func SetRoute(name, cidr string) (err error) {
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// ip route add 192.168.1.0/24 dev tap0
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out, cmdErr := exec.Command("ip", "route", "add", cidr, "dev", name).CombinedOutput()
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if cmdErr != nil {
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err = fmt.Errorf("%v:%v", cmdErr, string(out))
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return
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}
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return
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}
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// AddIP 通过ip命令添加IP地址
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func AddIP(name, ip string) (err error) {
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// ip addr add 192.168.1.1 dev tap0
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out, cmdErr := exec.Command("ip", "addr", "add", ip, "dev", name).CombinedOutput()
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if cmdErr != nil {
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err = fmt.Errorf("%v:%v",cmdErr, string(out))
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return
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}
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return
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}
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func GetHardwareAddr(name string) (string, error) {
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fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_DGRAM, 0) // 新建socket文件
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if err != nil {
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return "", nil
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}
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defer syscall.Close(fd)
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var ifreq struct {
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name [16]byte
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addr rawSockaddr
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_ [8]byte
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}
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copy(ifreq.name[:], name)
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_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), syscall.SIOCGIFHWADDR,
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uintptr(unsafe.Pointer(&ifreq))) // 获取硬件地址
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if errno != 0 {
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return "", errno
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}
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mac := ifreq.addr.Data[:6]
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return string(mac[:]), nil
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}
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