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tailscale/cmd/xdpderper/xdpderper.go

109 lines
2.8 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Command xdpderper runs the XDP STUN server.
package main
import (
"flag"
"io"
"log"
"net/http"
"os"
"os/signal"
"strings"
"syscall"
"github.com/prometheus/client_golang/prometheus"
"tailscale.com/derp/xdp"
"tailscale.com/net/netutil"
"tailscale.com/tsweb"
)
var (
flagDevice = flag.String("device", "", "target device name (default: autodetect)")
flagPort = flag.Int("dst-port", 0, "destination UDP port to serve")
flagVerbose = flag.Bool("verbose", false, "verbose output including verifier errors")
flagMode = flag.String("mode", "xdp", "XDP mode; valid modes: [xdp, xdpgeneric, xdpdrv, xdpoffload]")
flagHTTP = flag.String("http", ":8230", "HTTP listen address")
)
func main() {
flag.Parse()
var attachFlags xdp.XDPAttachFlags
switch strings.ToLower(*flagMode) {
case "xdp":
attachFlags = 0
case "xdpgeneric":
attachFlags = xdp.XDPGenericMode
case "xdpdrv":
attachFlags = xdp.XDPDriverMode
case "xdpoffload":
attachFlags = xdp.XDPOffloadMode
default:
log.Fatal("invalid mode")
}
deviceName := *flagDevice
if deviceName == "" {
var err error
deviceName, _, err = netutil.DefaultInterfacePortable()
if err != nil || deviceName == "" {
log.Fatalf("failed to detect default route interface: %v", err)
}
}
log.Printf("binding to device: %s", deviceName)
server, err := xdp.NewSTUNServer(&xdp.STUNServerConfig{
DeviceName: deviceName,
DstPort: *flagPort,
AttachFlags: attachFlags,
FullVerifierErr: *flagVerbose,
})
if err != nil {
log.Fatalf("failed to init XDP STUN server: %v", err)
}
defer server.Close()
err = prometheus.Register(server)
if err != nil {
log.Fatalf("failed to register XDP STUN server as a prometheus collector: %v", err)
}
log.Println("XDP STUN server started")
mux := http.NewServeMux()
debug := tsweb.Debugger(mux)
debug.KVFunc("Drop STUN", func() any {
return server.GetDropSTUN()
})
debug.Handle("drop-stun-on", "Drop STUN packets", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
err := server.SetDropSTUN(true)
if err != nil {
http.Error(w, err.Error(), 500)
} else {
io.WriteString(w, "STUN packets are now being dropped.")
}
}))
debug.Handle("drop-stun-off", "Handle STUN packets", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
err := server.SetDropSTUN(false)
if err != nil {
http.Error(w, err.Error(), 500)
} else {
io.WriteString(w, "STUN packets are now being handled.")
}
}))
errCh := make(chan error, 1)
go func() {
err := http.ListenAndServe(*flagHTTP, mux)
errCh <- err
}()
sigCh := make(chan os.Signal, 1)
signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
select {
case err := <-errCh:
log.Printf("HTTP serve err: %v", err)
case sig := <-sigCh:
log.Printf("received signal: %s", sig)
}
}