cname.go

package dnsutil

import "github.com/miekg/dns"

// DuplicateCNAME returns true if r already exists in records.
func DuplicateCNAME(r *dns.CNAME, records []dns.RR) bool {
	for _, rec := range records {
		if v, ok := rec.(*dns.CNAME); ok {
			if v.Target == r.Target {
				return true
			}
		}
	}
	return false
}