コード例 #1
0
ファイル: util.go プロジェクト: ChongFeng/beats
// TrimDomainName trims origin from s if s is a subdomain.
// This function will never return "", but returns "@" instead (@ represents the apex (bare) domain).
func TrimDomainName(s, origin string) string {
	// An apex (bare) domain is always returned as "@".
	// If the return value ends in a ".", the domain was not the suffix.
	// origin can end in "." or not. Either way the results should be the same.

	if len(s) == 0 {
		return "@" // Return the apex (@) rather than "".
	}
	// Someone is using TrimDomainName(s, ".") to remove a dot if it exists.
	if origin == "." {
		return strings.TrimSuffix(s, origin)
	}

	// Dude, you aren't even if the right subdomain!
	if !dns.IsSubDomain(origin, s) {
		return s
	}

	slabels := dns.Split(s)
	olabels := dns.Split(origin)
	m := dns.CompareDomainName(s, origin)
	if len(olabels) == m {
		if len(olabels) == len(slabels) {
			return "@" // origin == s
		}
		if (s[0] == '.') && (len(slabels) == (len(olabels) + 1)) {
			return "@" // TrimDomainName(".foo.", "foo.")
		}
	}

	// Return the first (len-m) labels:
	return s[:slabels[len(slabels)-m]-1]
}
コード例 #2
0
ファイル: resolver.go プロジェクト: karlpilkington/dnsr
// saveDNSRR saves 1 or more DNS records to the resolver cache.
func (r *Resolver) saveDNSRR(host string, qname string, drrs []dns.RR) RRs {
	var rrs RRs
	cl := dns.CountLabel(qname)
	for _, drr := range drrs {
		rr, ok := convertRR(drr)
		if !ok {
			continue
		}
		if dns.CountLabel(rr.Name) < cl && dns.CompareDomainName(qname, rr.Name) < 2 {
			// fmt.Fprintf(os.Stderr, "Warning: potential poisoning from %s: %s -> %s\n", host, qname, drr.String())
			continue
		}
		r.cache.add(rr.Name, rr)
		rrs = append(rrs, rr)
	}
	return rrs
}