normalize.go

package main

import (
	"github.com/miekg/dns"
	"strings"
)

// Zones represents a lists of zone names.
type Zones []string

// Matches checks if qname is a subdomain of any of the zones in z.  The match
// will return the most specific zones that matches. The empty string
// signals a not found condition.
func (z Zones) Matches(qname string) string {
	zone := ""
	for _, zname := range z {
		if dns.IsSubDomain(zname, qname) {
			// We want the *longest* matching zone, otherwise we may end up in a parent
			if len(zname) > len(zone) {
				zone = zname
			}
		}
	}
	return zone
}

// Normalize fully qualifies all zones in z. The zones in Z must be domain names, without
// a port or protocol prefix.
func (z Zones) Normalize() {
	for i := range z {
		z[i] = Name(z[i]).Normalize()
	}
}

// Name represents a domain name.
type Name string

// Matches checks to see if other is a subdomain (or the same domain) of n.
// This method assures that names can be easily and consistently matched.
func (n Name) Matches(child string) bool {
	if dns.Name(n) == dns.Name(child) {
		return true
	}
	return dns.IsSubDomain(string(n), child)
}

// Normalize lowercases and makes n fully qualified.
func (n Name) Normalize() string { return strings.ToLower(dns.Fqdn(string(n))) }