add profiling support

main.go

@@ -8,12 +8,15 @@ import (
 	"log"
 	"math"
 	"net"
+	"net/http"
 	"net/netip"
 	"sync"
+	"syscall"
+
+	_ "net/http/pprof"
 
 	"golang.org/x/net/ipv4"
 	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
 )
 
 const (
@@ -21,7 +24,7 @@ const (
 )
 
 var (
-	OOB_SIZE = unix.CmsgSpace(16 + 2) // ipv6 address + port
+	OOB_SIZE = syscall.CmsgSpace(syscall.SizeofInet6Pktinfo) // ipv6 address + iface index, struct in6_pktinfo
 )
 
 func (vx *vx46) transform46(msgs4 []ipv4.Message, msgs6 []ipv6.Message) error {
@@ -270,6 +273,7 @@ func main() {
 	portInt := flag.Int("port", 8472, "port for vxlan communication")
 	mtuInt := flag.Uint("mtu", 1422, "buffer size")
 	buffersInt := flag.Int("buffers", 64, "number of buffers for I/O batching")
+	pprofBool := flag.Bool("pprof", false, "enable pprof http endpoint on http://localhost:6060")
 
 	flag.Parse()
 
@@ -295,6 +299,12 @@ func main() {
 		log.Fatalf("buffers < 1: %d", *mtuInt)
 	}
 
+	if *pprofBool {
+		go func() {
+			log.Println(http.ListenAndServe("localhost:6060", nil))
+		}()
+	}
+
 	if *buffersInt == 1 {
 		log.Println(vx46forward(natprefix, upstreamAddr, port, mtu))
 	} else {