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https://github.com/netbirdio/netbird.git
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1d9feab2d9
Works only with userspace implementation: 1. Configure host to solve DNS requests via a fake DSN server address in the Netbird network. 2. Add to firewall catch rule for these DNS requests. 3. Resolve these DNS requests and respond by writing directly to wireguard device.
94 lines
2.0 KiB
Go
94 lines
2.0 KiB
Go
package dns
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import (
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"net"
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"testing"
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"github.com/golang/mock/gomock"
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"github.com/google/gopacket"
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"github.com/google/gopacket/layers"
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"github.com/miekg/dns"
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"github.com/netbirdio/netbird/iface/mocks"
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)
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func TestResponseWriterLocalAddr(t *testing.T) {
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ctrl := gomock.NewController(t)
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defer ctrl.Finish()
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device := mocks.NewMockDevice(ctrl)
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device.EXPECT().Write(gomock.Any(), gomock.Any())
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request := &dns.Msg{
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Question: []dns.Question{{
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Name: "google.com.",
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Qtype: dns.TypeA,
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Qclass: dns.TypeA,
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}},
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}
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replyMessage := &dns.Msg{}
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replyMessage.SetReply(request)
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replyMessage.RecursionAvailable = true
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replyMessage.Rcode = dns.RcodeSuccess
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replyMessage.Answer = []dns.RR{
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&dns.A{
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A: net.IPv4(8, 8, 8, 8),
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},
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}
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ipv4 := &layers.IPv4{
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Protocol: layers.IPProtocolUDP,
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SrcIP: net.IPv4(127, 0, 0, 1),
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DstIP: net.IPv4(127, 0, 0, 2),
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}
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udp := &layers.UDP{
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DstPort: 53,
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SrcPort: 45223,
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}
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if err := udp.SetNetworkLayerForChecksum(ipv4); err != nil {
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t.Error("failed to set network layer for checksum")
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return
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}
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// Serialize the packet
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buffer := gopacket.NewSerializeBuffer()
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options := gopacket.SerializeOptions{
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ComputeChecksums: true,
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FixLengths: true,
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}
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requestData, err := request.Pack()
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if err != nil {
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t.Errorf("got an error while packing the request message, error: %v", err)
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return
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}
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payload := gopacket.Payload(requestData)
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if err := gopacket.SerializeLayers(buffer, options, ipv4, udp, payload); err != nil {
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t.Errorf("failed to serialize packet: %v", err)
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return
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}
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rw := &responseWriter{
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local: &net.UDPAddr{
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IP: net.IPv4(127, 0, 0, 1),
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Port: 55223,
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},
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remote: &net.UDPAddr{
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IP: net.IPv4(127, 0, 0, 1),
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Port: 53,
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},
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packet: gopacket.NewPacket(
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buffer.Bytes(),
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layers.LayerTypeIPv4,
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gopacket.Default,
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),
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device: device,
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}
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if err := rw.WriteMsg(replyMessage); err != nil {
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t.Errorf("got an error while writing the local resolver response, error: %v", err)
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return
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}
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}
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