80 lines
1.5 KiB
Go
80 lines
1.5 KiB
Go
package service
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import (
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"fmt"
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"log"
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"net"
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"github.com/miekg/dns"
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)
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var dnsClient dns.Client
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func init() {
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dnsClient = dns.Client{
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Net: "tcp",
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}
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}
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func DNSUpdateEntry(domain string, hostname string, ip4 net.IP, ip6 net.IP) error {
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if ip4 == nil && ip6 == nil {
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return fmt.Errorf("at least one of --ipv4 and --ipv6 have to be set")
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}
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msg := new(dns.Msg)
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fqdn := fmt.Sprintf("%s.%s.", hostname, domain)
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zone := fmt.Sprintf("%s.", domain)
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msg.SetUpdate(zone)
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msg.RemoveName([]dns.RR{
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&dns.RR_Header{Name: fqdn},
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})
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var rrs []dns.RR
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if ip4 != nil {
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ip4bin := ip4.To4()
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if ip4bin == nil {
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return fmt.Errorf("ip4 (%v) is not a valid IPv4 address", ip4)
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}
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rrs = append(rrs, &dns.A{
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Hdr: dns.RR_Header{
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Name: fqdn,
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Rrtype: dns.TypeA,
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Class: dns.ClassINET,
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Ttl: C.DNS.DefaultTTL,
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},
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A: ip4bin,
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})
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}
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if ip6 != nil {
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ip6bin := ip6.To16()
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if ip6bin == nil {
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return fmt.Errorf("ip6 (%v) is not a valid IPv6 address", ip4)
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}
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rrs = append(rrs, &dns.AAAA{
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Hdr: dns.RR_Header{
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Name: fqdn,
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Rrtype: dns.TypeAAAA,
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Class: dns.ClassINET,
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Ttl: C.DNS.DefaultTTL,
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},
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AAAA: ip6bin,
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})
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}
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msg.Insert(rrs)
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log.Printf("Sending DNS Update for %s.%s:\n%v", hostname, domain, msg)
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reply, _, err := dnsClient.Exchange(msg, C.DNS.Server)
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if err != nil {
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return fmt.Errorf("failed to execute DNS Udpate: %v", err)
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}
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log.Printf("Received DNS Update Reply for %s.%s:\n%v", hostname, domain, reply)
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return nil
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}
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