45 lines
1.1 KiB
Go
45 lines
1.1 KiB
Go
package headscale
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import (
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"fmt"
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"strings"
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"inet.af/netaddr"
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"tailscale.com/util/dnsname"
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)
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func generateMagicDNSRootDomains(ipPrefix netaddr.IPPrefix, baseDomain string) (*[]dnsname.FQDN, error) {
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base, err := dnsname.ToFQDN(baseDomain)
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if err != nil {
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return nil, err
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}
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// TODO(juanfont): we are not handing out IPv6 addresses yet
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// and in fact this is Tailscale.com's range (not the fd7a:115c:a1e0: range in the fc00::/7 network)
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ipv6base := dnsname.FQDN("0.e.1.a.c.5.1.1.a.7.d.f.ip6.arpa.")
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fqdns := []dnsname.FQDN{base, ipv6base}
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netRange := ipPrefix.IPNet()
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maskBits, _ := netRange.Mask.Size()
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lastByte := maskBits / 8
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unmaskedBits := 8 - maskBits%8
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min := uint(netRange.IP[lastByte])
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max := uint((min + 1<<uint(unmaskedBits)) - 1)
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rdnsSlice := []string{}
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for i := lastByte - 1; i >= 0; i-- {
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rdnsSlice = append(rdnsSlice, fmt.Sprintf("%d", netRange.IP[i]))
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}
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rdnsSlice = append(rdnsSlice, "in-addr.arpa.")
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rdnsBase := strings.Join(rdnsSlice, ".")
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for i := min; i <= max; i++ {
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fqdn, err := dnsname.ToFQDN(fmt.Sprintf("%d.%s", i, rdnsBase))
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if err != nil {
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continue
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}
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fqdns = append(fqdns, fqdn)
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}
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return &fqdns, nil
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}
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