// Copyright (c) Tailscale Inc & AUTHORS // SPDX-License-Identifier: BSD-3-Clause // The vnet binary runs a virtual network stack in userspace for qemu instances // to connect to and simulate various network conditions. package main import ( "context" "flag" "log" "net" "os" "time" "tailscale.com/tstest/natlab/vnet" ) var ( listen = flag.String("listen", "/tmp/qemu.sock", "path to listen on") nat = flag.String("nat", "easy", "type of NAT to use") nat2 = flag.String("nat2", "hard", "type of NAT to use for second network") portmap = flag.Bool("portmap", false, "enable portmapping") dgram = flag.Bool("dgram", false, "enable datagram mode; for use with macOS Hypervisor.Framework and VZFileHandleNetworkDeviceAttachment") ) func main() { flag.Parse() if _, err := os.Stat(*listen); err == nil { os.Remove(*listen) } var srv net.Listener var err error var conn *net.UnixConn if *dgram { addr, err := net.ResolveUnixAddr("unixgram", *listen) if err != nil { log.Fatalf("ResolveUnixAddr: %v", err) } conn, err = net.ListenUnixgram("unixgram", addr) if err != nil { log.Fatalf("ListenUnixgram: %v", err) } defer conn.Close() } else { srv, err = net.Listen("unix", *listen) } if err != nil { log.Fatal(err) } var c vnet.Config node1 := c.AddNode(c.AddNetwork("2.1.1.1", "192.168.1.1/24", vnet.NAT(*nat))) c.AddNode(c.AddNetwork("2.2.2.2", "10.2.0.1/16", vnet.NAT(*nat2))) if *portmap { node1.Network().AddService(vnet.NATPMP) } s, err := vnet.New(&c) if err != nil { log.Fatalf("newServer: %v", err) } if err := s.PopulateDERPMapIPs(); err != nil { log.Printf("warning: ignoring failure to populate DERP map: %v", err) } s.WriteStartingBanner(os.Stdout) go func() { getStatus := func() { ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) defer cancel() st, err := s.NodeStatus(ctx, node1) if err != nil { log.Printf("NodeStatus: %v", err) return } log.Printf("NodeStatus: %q", st) } for { time.Sleep(5 * time.Second) //continue getStatus() } }() if conn != nil { s.ServeUnixConn(conn, vnet.ProtocolUnixDGRAM) return } for { c, err := srv.Accept() if err != nil { log.Printf("Accept: %v", err) continue } go s.ServeUnixConn(c.(*net.UnixConn), vnet.ProtocolQEMU) } }