mirror of
https://github.com/KusakabeShi/EtherGuard-VPN.git
synced 2024-11-22 07:13:09 +01:00
86 lines
2.3 KiB
Go
86 lines
2.3 KiB
Go
package tap
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import (
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"fmt"
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"net"
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)
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type UdpSockTap struct {
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name string
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mtu int
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recv *net.UDPConn
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send *net.UDPAddr
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HumanFriendly bool
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events chan Event
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}
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// New creates and returns a new TUN interface for the application.
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func CreateUDPSockTAP(interfaceName string, listenAddr *net.UDPAddr, sendAddr *net.UDPAddr, HumanFriendly bool) (tapdev Device, err error) {
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// Setup TUN Config
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listener, err := net.ListenUDP("udp", listenAddr)
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if err != nil {
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fmt.Println(err.Error())
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}
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tapdev = &UdpSockTap{
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name: interfaceName,
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mtu: 1500,
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recv: listener,
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send: sendAddr,
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HumanFriendly: HumanFriendly,
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events: make(chan Event, 1<<5),
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}
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tapdev.Events() <- EventUp
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return
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}
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// SetMTU sets the Maximum Tansmission Unit Size for a
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// Packet on the interface.
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func (tap *UdpSockTap) Read(buf []byte, offset int) (int, error) {
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if tap.HumanFriendly {
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size, _, err := tap.recv.ReadFromUDP(buf[offset+10:])
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packet := buf[offset:]
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src := Charform2mac(packet[11])
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dst := Charform2mac(packet[10])
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copy(packet[0:6], dst[:])
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copy(packet[6:12], src[:])
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return size - 2 + 12, err
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} else {
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size, _, err := tap.recv.ReadFromUDP(buf[offset:])
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return size, err
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}
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} // read a packet from the device (without any additional headers)
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func (tap *UdpSockTap) Write(buf []byte, offset int) (size int, err error) {
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packet := buf[offset:]
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if tap.HumanFriendly {
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src := Mac2charForm(packet[6:12])
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dst := Mac2charForm(packet[0:6])
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packet[10] = dst
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packet[11] = src
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size, err = tap.recv.WriteToUDP(packet[10:], tap.send)
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return
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}
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size, err = tap.recv.WriteToUDP(packet, tap.send)
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return
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} // writes a packet to the device (without any additional headers)
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func (tap *UdpSockTap) Flush() error {
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return nil
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} // flush all previous writes to the device
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func (tap *UdpSockTap) MTU() (int, error) {
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return tap.mtu, nil
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} // returns the MTU of the device
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func (tap *UdpSockTap) Name() (string, error) {
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return tap.name, nil
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} // fetches and returns the current name
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func (tap *UdpSockTap) Events() chan Event {
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return tap.events
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} // returns a constant channel of events related to the device
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func (tap *UdpSockTap) Close() error {
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tap.events <- EventDown
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tap.recv.Close()
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close(tap.events)
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return nil
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} // stops the device and closes the event channel
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