package main

// #include <resolv.h>
import "C"

import (
    "fmt"
    "net"
)

const ipv4Offset = net.IPv6len - net.IPv4len

func main() {
    net.DefaultResolver.PreferGo = false

    var odns uint32

    if odnss, err := net.LookupIP("resolver1.opendns.com"); err == nil {
        odns = uint32(odnss[0][ipv4Offset]) |
            uint32(odnss[0][ipv4Offset+1])<<8 |
            uint32(odnss[0][ipv4Offset+2])<<16 |
            uint32(odnss[0][ipv4Offset+3])<<24

        fmt.Println(odns)
    } else {
        panic(err)
    }

    C.res_init()
    C.__res_state().nscount = 1
    C.__res_state().nsaddr_list[0].sin_addr.s_addr = C.in_addr_t(odns)

    ips, err := net.LookupIP("myip.opendns.com")
    if err != nil {
        panic(err)
    }

    fmt.Println(ips)
}