mirror of https://github.com/mpolden/echoip
39 lines
671 B
Go
39 lines
671 B
Go
package iputil
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import (
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"fmt"
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"math/big"
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"net"
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"strings"
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"time"
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)
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func LookupAddr(ip net.IP) (string, error) {
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names, err := net.LookupAddr(ip.String())
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if err != nil || len(names) == 0 {
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return "", err
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}
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// Always return unrooted name
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return strings.TrimRight(names[0], "."), nil
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}
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func LookupPort(ip net.IP, port uint64) error {
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address := fmt.Sprintf("[%s]:%d", ip, port)
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conn, err := net.DialTimeout("tcp", address, 2*time.Second)
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if err != nil {
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return err
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}
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defer conn.Close()
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return nil
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}
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func ToDecimal(ip net.IP) *big.Int {
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i := big.NewInt(0)
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if to4 := ip.To4(); to4 != nil {
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i.SetBytes(to4)
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} else {
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i.SetBytes(ip)
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}
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return i
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}
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