nflog with Go

nflog.go

package main

import (
	"log"
	"os"
	"unsafe"
)

/*
#cgo pkg-config: libnetfilter_log
#include <stdlib.h>
#include <libnetfilter_log/libnetfilter_log.h>
#include "binding.h"
*/
import "C"

//export NflogCb
func NflogCb(gh *C.struct_nflog_g_handle, nfmsg *C.struct_nfgenmsg, nfa *C.struct_nflog_data, data unsafe.Pointer) C.int {
	log.Print("NflogCb")
	return 0
}

func main() {
	h := C.nflog_open()
	if uintptr(unsafe.Pointer(h)) == uintptr(0) {
		log.Fatal("Failed nflog_open")
	}
	qh := C.nflog_bind_group(h, 10)
	if uintptr(unsafe.Pointer(qh)) == uintptr(0) {
		log.Fatal("Failed nflog_bind_group")
	}

	//C.nflog_callback_register(qh, (*C.nflog_callback)(uintptr(unsafe.Pointer(&NflogCb))), unsafe.Pointer(uintptr(0)))
	C.SetCallback(qh)

	fd := C.nflog_fd(h)

	f := os.NewFile(uintptr(fd), "nflog fd")

	buf := make([]byte, 1024)
	for {
		rlen, err := f.Read(buf)
		if err != nil {
			log.Print(err)
			break
		}
		log.Print("read nflog: len=", rlen)
		if err := C.nflog_handle_packet(h, (*C.char)(unsafe.Pointer(&buf[0])), C.int(rlen)); err != 0 {
			log.Print("Failed nflog_handle_packet: ", err)
		}
	}
}