Version: v1.10.0 Latest Latest

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Published: Sep 19, 2022 License: Apache-2.0 Imports: 6 Imported by: 1,046



Package dnsutil contains DNS related helper functions.



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const (
	// IP4arpa is the reverse tree suffix for v4 IP addresses.
	IP4arpa = ".in-addr.arpa."
	// IP6arpa is the reverse tree suffix for v6 IP addresses.
	IP6arpa = ".ip6.arpa."
View Source
const (
	// MinimalDefaultTTL is the absolute lowest TTL we use in CoreDNS.
	MinimalDefaultTTL = 5 * time.Second
	// MaximumDefaulTTL is the maximum TTL was use on RRsets in CoreDNS.
	MaximumDefaulTTL = 1 * time.Hour


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func DuplicateCNAME

func DuplicateCNAME(r *dns.CNAME, records []dns.RR) bool

DuplicateCNAME returns true if r already exists in records.

func ExtractAddressFromReverse

func ExtractAddressFromReverse(reverseName string) string

ExtractAddressFromReverse turns a standard PTR reverse record name into an IP address. This works for ipv4 or ipv6. becomes If the conversion fails the empty string is returned.

func IsReverse added in v1.1.0

func IsReverse(name string) int

IsReverse returns 0 is name is not in a reverse zone. Anything > 0 indicates name is in a reverse zone. The returned integer will be 1 for in-addr.arpa. (IPv4) and 2 for ip6.arpa. (IPv6).

func Join

func Join(labels ...string) string

Join joins labels to form a fully qualified domain name. If the last label is the root label it is ignored. Not other syntax checks are performed.

func MinimalTTL added in v1.2.0

func MinimalTTL(m *dns.Msg, mt response.Type) time.Duration

MinimalTTL scans the message returns the lowest TTL found taking into the response.Type of the message.

func TrimZone

func TrimZone(q string, z string) (string, error)

TrimZone removes the zone component from q. It returns the trimmed name or an error is zone is longer then qname. The trimmed name will be returned without a trailing dot.


This section is empty.

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