65 lines
1.3 KiB
Go
65 lines
1.3 KiB
Go
/*
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* Copyright 2022 The Dragonfly Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package ip
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import (
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"fmt"
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"net"
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)
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var (
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// IPv6 is external address.
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IPv6 net.IP
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// IPv6lookback is lookback address.
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IPv6lookback = net.IPv6loopback
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)
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func init() {
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ip, err := externalIPv6()
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if err != nil {
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IPv6 = IPv6lookback
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} else {
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IPv6 = ip
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}
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}
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// externalIPv6 returns the available IPv6.
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func externalIPv6() (net.IP, error) {
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ips, err := ipAddrs()
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if err != nil {
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return nil, err
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}
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var externalIPs []net.IP
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for _, ip := range ips {
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ipv4 := ip.To4()
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if ipv4 != nil {
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continue // skip all ipv4 address
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}
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ipv6 := ip.To16()
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externalIPs = append(externalIPs, ipv6)
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}
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if len(externalIPs) == 0 {
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return nil, fmt.Errorf("can not found external ipv6")
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}
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return externalIPs[0], nil
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}
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