asn.go

package main

import (
  "encoding/json"
	"github.com/miekg/bitradix"
	"log"
	"net"
	"os"
	"reflect"
)

func main() {
	r32 := bitradix.New32()
	dec := json.NewDecoder(os.Stdin)
	for {
		var v map[string]interface{}
		if err := dec.Decode(&v); err != nil {
			log.Println(err)
			break
		}
		for _, v1 := range v {
			for ip, v2 := range v1.(map[string]interface{}) {
				addRoute(r32, ip, uint32(v2.(float64)))
			}
		}
	}

	// uncomment to print
//	r32.Do(func(r1 *bitradix.Radix32, i int) { log.Printf("(%2d): %032b/%d -> %d\n", i, r1.Key(), r1.Bits(), r1.Value) })
}

func ipToUint(n *net.IPNet) (i uint32, mask int) {
	ip := n.IP.To4()
	fv := reflect.ValueOf(&i).Elem()
	fv.SetUint(uint64(uint32(ip[0])<<24 | uint32(ip[1])<<16 | uint32(ip[2])<<8 | uint32(ip[+3])))
	mask, _ = n.Mask.Size()
	return
}

func addRoute(r *bitradix.Radix32, s string, asn uint32) {
	_, ipnet, err := net.ParseCIDR(s)
	if err != nil {
		log.Println(err)
		return
	}
	net, mask := ipToUint(ipnet)
	r.Insert(net, mask, asn)
}