2021-01-05 14:10:11 +08:00
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package utils
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import (
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"github.com/miekg/dns"
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)
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2021-07-19 15:23:20 +08:00
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// LookupCNAME 获取CNAME
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2021-01-05 14:10:11 +08:00
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func LookupCNAME(host string) (string, error) {
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config, err := dns.ClientConfigFromFile("/etc/resolv.conf")
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if err != nil {
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return "", err
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}
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c := new(dns.Client)
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m := new(dns.Msg)
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m.SetQuestion(host+".", dns.TypeCNAME)
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m.RecursionDesired = true
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r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
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if err != nil {
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return "", err
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}
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if len(r.Answer) == 0 {
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return "", nil
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}
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return r.Answer[0].(*dns.CNAME).Target, nil
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}
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