Golang dns.IsSubDomain函數代碼示例

// Sign signs a message m, it takes care of negative or nodata responses as
// well by synthesising NSEC3 records. It will also cache the signatures, using
// a hash of the signed data as a key.
// We also fake the origin TTL in the signature, because we don't want to
// throw away signatures when services decide to have longer TTL. So we just
// set the origTTL to 60.
// TODO(miek): revisit origTTL
func (s *server) Sign(m *dns.Msg, bufsize uint16) {
	now := time.Now().UTC()
	incep := uint32(now.Add(-3 * time.Hour).Unix())     // 2+1 hours, be sure to catch daylight saving time and such
	expir := uint32(now.Add(7 * 24 * time.Hour).Unix()) // sign for a week

	defer func() {
		promCacheSize.WithLabelValues("signature").Set(float64(s.scache.Size()))
	}()

	for _, r := range rrSets(m.Answer) {
		if r[0].Header().Rrtype == dns.TypeRRSIG {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Answer = append(m.Answer, sig)
		}
	}
	for _, r := range rrSets(m.Ns) {
		if r[0].Header().Rrtype == dns.TypeRRSIG {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Ns = append(m.Ns, sig)
		}
	}
	for _, r := range rrSets(m.Extra) {
		if r[0].Header().Rrtype == dns.TypeRRSIG || r[0].Header().Rrtype == dns.TypeOPT {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Extra = append(m.Extra, sig)
		}
	}
	if bufsize >= 512 || bufsize <= 4096 {
		// TCP here?
		promErrorCount.WithLabelValues("truncated").Inc()
		m.Truncated = m.Len() > int(bufsize)
	}
	o := new(dns.OPT)
	o.Hdr.Name = "."
	o.Hdr.Rrtype = dns.TypeOPT
	o.SetDo()
	o.SetUDPSize(4096) // TODO(miek): echo client
	m.Extra = append(m.Extra, o)
	return
}

// subzoneConflict returns true if name is a child or parent zone of
// any element in zones. If conflicts exist, return the conflicting zones.
func subzoneConflict(zones []string, name string) (bool, []string) {
	conflicts := []string{}

	for _, z := range zones {
		if dns.IsSubDomain(z, name) || dns.IsSubDomain(name, z) {
			conflicts = append(conflicts, z)
		}
	}

	return (len(conflicts) != 0), conflicts
}

func ParseSOA(d string, r []dns.RR) (*dns.SOA, []*dns.NS, *MyError.MyError) {
	var soa *dns.SOA
	var ns_a []*dns.NS
	for _, v := range r {
		vh := v.Header()
		if vh.Name == dns.Fqdn(d) || dns.IsSubDomain(vh.Name, dns.Fqdn(d)) {
			switch vh.Rrtype {
			case dns.TypeSOA:
				if vv, ok := v.(*dns.SOA); ok {
					//fmt.Print(utils.GetDebugLine(), "ParseSOA:  ", vv)
					soa = vv
					utils.ServerLogger.Debug("ParseSOA: %v", vv)
				}
			case dns.TypeNS:
				if vv, ok := v.(*dns.NS); ok {
					ns_a = append(ns_a, vv)
				}
			default:
				//fmt.Println(utils.GetDebugLine(), " PasreSOA: error unexpect: ", v)
				utils.ServerLogger.Error("ParseSOA: error unexpect %v", v)
			}
		} else {
			//fmt.Print(utils.GetDebugLine(), "ParseSOA 258 ")
			//fmt.Println(utils.GetDebugLine(), vh.Name+" not match "+d)
			utils.ServerLogger.Debug("%s not match %s", vh.Name, d)
			return nil, nil, MyError.NewError(MyError.ERROR_NOTVALID, d+" has no SOA record,try parent")
		}

	}
	if soa != nil {
		return soa, ns_a, nil
	} else {
		return nil, nil, MyError.NewError(MyError.ERROR_NORESULT, "No SOA record for domain "+d)
	}
}

func (e Etcd) AAAA(zone string, state middleware.State, previousRecords []dns.RR) (records []dns.RR, debug []msg.Service, err error) {
	services, debug, err := e.records(state, false)
	if err != nil {
		return nil, debug, err
	}

	for _, serv := range services {
		ip := net.ParseIP(serv.Host)
		switch {
		case ip == nil:
			// Try to resolve as CNAME if it's not an IP, but only if we don't create loops.
			if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
				// x CNAME x is a direct loop, don't add those
				continue
			}

			newRecord := serv.NewCNAME(state.QName(), serv.Host)
			if len(previousRecords) > 7 {
				// don't add it, and just continue
				continue
			}
			if isDuplicateCNAME(newRecord, previousRecords) {
				continue
			}

			state1 := copyState(state, serv.Host, state.QType())
			nextRecords, nextDebug, err := e.AAAA(zone, state1, append(previousRecords, newRecord))

			if err == nil {
				// Not only have we found something we should add the CNAME and the IP addresses.
				if len(nextRecords) > 0 {
					records = append(records, newRecord)
					records = append(records, nextRecords...)
					debug = append(debug, nextDebug...)
				}
				continue
			}
			// This means we can not complete the CNAME, try to look else where.
			target := newRecord.Target
			if dns.IsSubDomain(zone, target) {
				// We should already have found it
				continue
			}
			m1, e1 := e.Proxy.Lookup(state, target, state.QType())
			if e1 != nil {
				continue
			}
			// Len(m1.Answer) > 0 here is well?
			records = append(records, newRecord)
			records = append(records, m1.Answer...)
			continue
			// both here again
		case ip.To4() != nil:
			// nada?
		case ip.To4() == nil:
			records = append(records, serv.NewAAAA(state.QName(), ip.To16()))
		}
	}
	return records, debug, nil
}

// 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]
}

// 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)
}

// Sign signs a message m, it takes care of negative or nodata responses as
// well by synthesising NSEC3 records. It will also cache the signatures, using
// a hash of the signed data as a key.
// We also fake the origin TTL in the signature, because we don't want to
// throw away signatures when services decide to have longer TTL. So we just
// set the origTTL to 60.
// TODO(miek): revisit origTTL
func (s *server) Sign(m *dns.Msg, bufsize uint16) {
	now := time.Now().UTC()
	incep := uint32(now.Add(-3 * time.Hour).Unix())     // 2+1 hours, be sure to catch daylight saving time and such
	expir := uint32(now.Add(7 * 24 * time.Hour).Unix()) // sign for a week

	for _, r := range rrSets(m.Answer) {
		if r[0].Header().Rrtype == dns.TypeRRSIG {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Answer = append(m.Answer, sig)
		}
	}
	for _, r := range rrSets(m.Ns) {
		if r[0].Header().Rrtype == dns.TypeRRSIG {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Ns = append(m.Ns, sig)
		}
	}
	for _, r := range rrSets(m.Extra) {
		if r[0].Header().Rrtype == dns.TypeRRSIG || r[0].Header().Rrtype == dns.TypeOPT {
			continue
		}
		if !dns.IsSubDomain(s.config.Domain, r[0].Header().Name) {
			continue
		}
		if sig, err := s.signSet(r, now, incep, expir); err == nil {
			m.Extra = append(m.Extra, sig)
		}
	}

	o := new(dns.OPT)
	o.Hdr.Name = "."
	o.Hdr.Rrtype = dns.TypeOPT
	o.SetDo()
	o.SetUDPSize(4096) // TODO(miek): echo client
	m.Extra = append(m.Extra, o)
	return
}

// MXRecords returns MX records from etcd.
// If the Target is not a name but an IP address, a name is created.
func (s *server) MXRecords(q dns.Question, name string, bufsize uint16, dnssec bool) (records []dns.RR, extra []dns.RR, err error) {

	return nil, nil, errors.New("Not Implement !")

	services, err := s.backend.Records(name, false)
	if err != nil {
		return nil, nil, err
	}

	lookup := make(map[string]bool)
	for _, serv := range services {
		if !serv.Mail {
			continue
		}
		ip := net.ParseIP(serv.Host)
		switch {
		case ip == nil:
			mx := serv.NewMX(q.Name)
			records = append(records, mx)
			if _, ok := lookup[mx.Mx]; ok {
				break
			}

			lookup[mx.Mx] = true

			if !dns.IsSubDomain(s.config.Domain, mx.Mx) {
				m1, e1 := s.Lookup(mx.Mx, dns.TypeA, bufsize, dnssec)
				if e1 == nil {
					extra = append(extra, m1.Answer...)
				}
				m1, e1 = s.Lookup(mx.Mx, dns.TypeAAAA, bufsize, dnssec)
				if e1 == nil {
					// If we have seen CNAME's we *assume* that they are already added.
					for _, a := range m1.Answer {
						if _, ok := a.(*dns.CNAME); !ok {
							extra = append(extra, a)
						}
					}
				}
				break
			}
			// Internal name
			addr, e1 := s.AddressRecords(dns.Question{mx.Mx, dns.ClassINET, dns.TypeA},
				mx.Mx, nil, bufsize, dnssec, true)
			if e1 == nil {
				extra = append(extra, addr...)
			}
		case ip.To4() != nil:
			serv.Host = msg.Domain(serv.Key)
			records = append(records, serv.NewMX(q.Name))
			extra = append(extra, serv.NewA(serv.Host, ip.To4()))
		case ip.To4() == nil:
			serv.Host = msg.Domain(serv.Key)
			records = append(records, serv.NewMX(q.Name))
			extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
		}
	}
	return records, extra, nil
}

// MX returns MX records from etcd.
// If the Target is not a name but an IP address, a name is created on the fly.
func (e Etcd) MX(zone string, state middleware.State) (records, extra []dns.RR, debug []msg.Service, err error) {
	services, debug, err := e.records(state, false)
	if err != nil {
		return nil, nil, debug, err
	}

	lookup := make(map[string]bool)
	for _, serv := range services {
		if !serv.Mail {
			continue
		}
		ip := net.ParseIP(serv.Host)
		switch {
		case ip == nil:
			mx := serv.NewMX(state.QName())
			records = append(records, mx)
			if _, ok := lookup[mx.Mx]; ok {
				break
			}

			lookup[mx.Mx] = true

			if !dns.IsSubDomain(zone, mx.Mx) {
				m1, e1 := e.Proxy.Lookup(state, mx.Mx, dns.TypeA)
				if e1 == nil {
					extra = append(extra, m1.Answer...)
				}
				m1, e1 = e.Proxy.Lookup(state, mx.Mx, dns.TypeAAAA)
				if e1 == nil {
					// If we have seen CNAME's we *assume* that they are already added.
					for _, a := range m1.Answer {
						if _, ok := a.(*dns.CNAME); !ok {
							extra = append(extra, a)
						}
					}
				}
				break
			}
			// Internal name
			state1 := copyState(state, mx.Mx, dns.TypeA)
			addr, debugAddr, e1 := e.A(zone, state1, nil)
			if e1 == nil {
				extra = append(extra, addr...)
				debug = append(debug, debugAddr...)
			}
			// e.AAAA as well
		case ip.To4() != nil:
			serv.Host = msg.Domain(serv.Key)
			records = append(records, serv.NewMX(state.QName()))
			extra = append(extra, serv.NewA(serv.Host, ip.To4()))
		case ip.To4() == nil:
			serv.Host = msg.Domain(serv.Key)
			records = append(records, serv.NewMX(state.QName()))
			extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
		}
	}
	return records, extra, debug, nil
}

func (k Kubernetes) A(zone string, state middleware.State, previousRecords []dns.RR) (records []dns.RR, err error) {
	services, err := k.records(state, false)
	if err != nil {
		return nil, err
	}

	for _, serv := range services {
		ip := net.ParseIP(serv.Host)
		switch {
		case ip == nil:
			// TODO(miek): lowercasing? Should lowercase in everything see #85
			if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
				// x CNAME x is a direct loop, don't add those
				continue
			}

			newRecord := serv.NewCNAME(state.QName(), serv.Host)
			if len(previousRecords) > 7 {
				// don't add it, and just continue
				continue
			}
			if isDuplicateCNAME(newRecord, previousRecords) {
				continue
			}

			state1 := copyState(state, serv.Host, state.QType())
			nextRecords, err := k.A(zone, state1, append(previousRecords, newRecord))

			if err == nil {
				// Not only have we found something we should add the CNAME and the IP addresses.
				if len(nextRecords) > 0 {
					records = append(records, newRecord)
					records = append(records, nextRecords...)
				}
				continue
			}
			// This means we can not complete the CNAME, try to look else where.
			target := newRecord.Target
			if dns.IsSubDomain(zone, target) {
				// We should already have found it
				continue
			}
			m1, e1 := k.Proxy.Lookup(state, target, state.QType())
			if e1 != nil {
				continue
			}
			// Len(m1.Answer) > 0 here is well?
			records = append(records, newRecord)
			records = append(records, m1.Answer...)
			continue
		case ip.To4() != nil:
			records = append(records, serv.NewA(state.QName(), ip.To4()))
		case ip.To4() == nil:
			// nodata?
		}
	}
	return records, nil
}

// Matches checks is qname is a subdomain of any of the zones in z.  The match
// will return the most specific zones that matches other. 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) {
			if len(zname) > len(zone) {
				zone = zname
			}
		}
	}
	return zone
}

func serve(w dns.ResponseWriter, req *dns.Msg, z *dns.Zone) {
	if z == nil {
		panic("fksd: no zone")
	}

	m := new(dns.Msg)
	// Just NACK ANYs
	if req.Question[0].Qtype == dns.TypeANY {
		m.SetRcode(req, dns.RcodeServerFailure)
		ednsFromRequest(req, m)
		w.WriteMsg(m)
		return
	}

	logPrintf("[zone %s] incoming %s %s %d from %s\n", z.Origin, req.Question[0].Name, dns.TypeToString[req.Question[0].Qtype], req.MsgHdr.Id, w.RemoteAddr())
	node, exact, ref := z.FindFunc(req.Question[0].Name, func(n interface{}) bool {
		return n.(*dns.ZoneData).NonAuth
	})
	if ref {
		logPrintf("[zone %s] referral due\n", z.Origin)
		m.SetReply(req)
		m.Ns = node.RR[dns.TypeNS]
		for _, n := range m.Ns {
			if dns.IsSubDomain(n.(*dns.NS).Ns, n.Header().Name) {
				findGlue(m, z, n.(*dns.NS).Ns)
			}
		}
		ednsFromRequest(req, m)
		w.WriteMsg(m)
		return
	}
	if exact {
		exactMatch(w, req, m, z, node)
		return
	}
	// Not an exact match nor an referral

	if z.Wildcard > 0 {
		lx := dns.SplitLabels(req.Question[0].Name)
		wc := "*." + strings.Join(lx[1:], ".")
		node, exact = z.Find(wc)
		if exact {
			logPrintf("[zone %s] wildcard answer\n", z.Origin)
			// as exact,but not complete -- only the last part
		}
	}
	nameerror(w, m, req)
	return
}

// Lookup looks up qname and qtype in the zone. When do is true DNSSEC records are included.
// Three sets of records are returned, one for the answer, one for authority  and one for the additional section.
func (z *Zone) Lookup(qname string, qtype uint16, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
	if qtype == dns.TypeSOA {
		return z.lookupSOA(do)
	}
	if qtype == dns.TypeNS && qname == z.origin {
		return z.lookupNS(do)
	}

	elem, res := z.Tree.Search(qname, qtype)
	if elem == nil {
		if res == tree.EmptyNonTerminal {
			return z.emptyNonTerminal(qname, do)
		}
		return z.nameError(qname, qtype, do)
	}
	if res == tree.Delegation {
		rrs := elem.Types(dns.TypeNS)
		glue := []dns.RR{}
		for _, ns := range rrs {
			if dns.IsSubDomain(ns.Header().Name, ns.(*dns.NS).Ns) {
				// even with Do, this should be unsigned.
				elem, res := z.Tree.SearchGlue(ns.(*dns.NS).Ns)
				if res == tree.Found {
					glue = append(glue, elem.Types(dns.TypeAAAA)...)
					glue = append(glue, elem.Types(dns.TypeA)...)
				}
			}
		}
		return nil, rrs, glue, Delegation
	}

	rrs := elem.Types(dns.TypeCNAME)
	if len(rrs) > 0 { // should only ever be 1 actually; TODO(miek) check for this?
		return z.lookupCNAME(rrs, qtype, do)
	}

	rrs = elem.Types(qtype)
	if len(rrs) == 0 {
		return z.noData(elem, do)
	}

	if do {
		sigs := elem.Types(dns.TypeRRSIG)
		sigs = signatureForSubType(sigs, qtype)
		rrs = append(rrs, sigs...)
	}
	return rrs, nil, nil, Success
}

// getZoneForName returns the zone string that matches the name and a
// list of the DNS labels from name that are within the zone.
// For example, if "coredns.local" is a zone configured for the
// Kubernetes middleware, then getZoneForName("a.b.coredns.local")
// will return ("coredns.local", ["a", "b"]).
func (g Kubernetes) getZoneForName(name string) (string, []string) {
	var zone string
	var serviceSegments []string

	for _, z := range g.Zones {
		if dns.IsSubDomain(z, name) {
			zone = z

			serviceSegments = dns.SplitDomainName(name)
			serviceSegments = serviceSegments[:len(serviceSegments)-dns.CountLabel(zone)]
			break
		}
	}

	return zone, serviceSegments
}

// Handle exact match
func exactMatch(w dns.ResponseWriter, req, m *dns.Msg, z *dns.Zone, node *dns.ZoneData) {
	logPrintf("[zone %s] exact match for %s\n", z.Origin, req.Question[0].Name)
	// If we have NS records for this name we still need to give out a referral
	if nss, ok := node.RR[dns.TypeNS]; ok && node.NonAuth {
		m.SetReply(req)
		m.Ns = nss
		for _, n := range m.Ns {
			if dns.IsSubDomain(n.(*dns.NS).Ns, n.Header().Name) {
				findGlue(m, z, n.(*dns.NS).Ns)
			}
		}
		ednsFromRequest(req, m)
		w.WriteMsg(m)
		return
	}
	// If we have the actual type too
	if rrs, ok := node.RR[req.Question[0].Qtype]; ok {
		answer(w, m, req, rrs, z)
		return
	} else { // NoData reply or CNAME
		m.SetReply(req)
		if cname, ok := node.RR[dns.TypeCNAME]; ok {
			m.Answer = cname
			/*
				i  := 0
				for cname.Rrtype == dns.TypeCNAME {


				}
			*/
			// Lookup cname.Target
			// get cname RRssss

		}
		findApex(m, z)
		w.WriteMsg(m)
		return
	}
	nameerror(w, m, req)
	return
}