package aghnet
import (
"fmt"
"net/netip"
"strings"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/stringutil"
)
// GenerateHostname generates the hostname from ip. In case of using IPv4 the
// result should be like:
//
// 192-168-10-1
// In case of using IPv6, the result is like:
// ff80-f076-0000-0000-0000-0000-0000-0010
// ip must be either an IPv4 or an IPv6.
func GenerateHostname(ip netip.Addr) (hostname string) {
if !ip.IsValid() {
// TODO(s.chzhen): Get rid of it.
panic("aghnet generate hostname: invalid ip")
}
ip = ip.Unmap()
hostname = ip.StringExpanded()
if ip.Is4() {
return strings.Replace(hostname, ".", "-", -1)
return strings.Replace(hostname, ":", "-", -1)
// NewDomainNameSet returns nil and error, if list has duplicate or empty
// domain name. Otherwise returns a set, which contains non-FQDN domain names,
// and nil error.
func NewDomainNameSet(list []string) (set *stringutil.Set, err error) {
set = stringutil.NewSet()
for i, v := range list {
host := strings.ToLower(strings.TrimSuffix(v, "."))
// TODO(a.garipov): Think about ignoring empty (".") names in the
// future.
if host == "" {
return nil, errors.Error("host name is empty")
if set.Has(host) {
return nil, fmt.Errorf("duplicate host name %q at index %d", host, i)
set.Add(host)
return set, nil