func dnsAppend(q dns.Question, m *dns.Msg, rr dns.RR) {
hdr := dns.RR_Header{Name: q.Name, Class: q.Qclass, Ttl: 0}
if rrS, ok := rr.(*dns.A); ok {
hdr.Rrtype = dns.TypeA
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.AAAA); ok {
hdr.Rrtype = dns.TypeAAAA
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.CNAME); ok {
hdr.Rrtype = dns.TypeCNAME
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.TXT); ok {
hdr.Rrtype = dns.TypeTXT
rrS.Hdr = hdr
} else {
log.Printf("error: unknown dnsAppend RR type: %+v\n", rr)
return
}
if q.Qtype == dns.TypeANY || q.Qtype == rr.Header().Rrtype {
m.Answer = append(m.Answer, rr)
} else {
m.Extra = append(m.Extra, rr)
}
}
// update record
func updateRecord(r dns.RR, q *dns.Question) {
// record to update
var rr dns.RR
// IP of record
var ip net.IP
header := r.Header()
if _, ok := dns.IsDomainName(header.Name); ok {
if header.Class == dns.ClassANY && header.Rdlength == 0 { // Delete record
deleteRecord(header.Name, header.Rrtype)
} else { // Add record
rheader := dns.RR_Header{
Name: header.Name,
Rrtype: header.Rrtype,
Class: dns.ClassINET,
Ttl: header.Ttl,
}
// IPv4 only
if a, ok := r.(*dns.A); ok {
rrr, err := getRecord(header.Name, header.Rrtype)
if err == nil {
rr = rrr.(*dns.A)
} else {
rr = new(dns.A)
}
ip = a.A
rr.(*dns.A).Hdr = rheader
rr.(*dns.A).A = ip
saveRecord(rr)
}
}
}
}
func updateRecord(r dns.RR, q *dns.Question) {
if *debug {
Log.Printf("updateRecord: resource record: %+v, question: %+v\n", r, q)
}
var (
rr dns.RR
name string
rtype uint16
ttl uint32
ip net.IP
)
header := r.Header()
name = header.Name
rtype = header.Rrtype
ttl = header.Ttl
if _, ok := dns.IsDomainName(name); ok {
if header.Class == dns.ClassANY && header.Rdlength == 0 { // Delete record
deleteRecord(name, rtype)
} else { // Add record
rheader := dns.RR_Header{
Name: name,
Rrtype: rtype,
Class: dns.ClassINET,
Ttl: ttl,
}
if a, ok := r.(*dns.A); ok {
rrr, err := getRecord(name, rtype)
if err == nil {
rr = rrr.(*dns.A)
} else {
rr = new(dns.A)
}
ip = a.A
rr.(*dns.A).Hdr = rheader
rr.(*dns.A).A = ip
} else if a, ok := r.(*dns.AAAA); ok {
rrr, err := getRecord(name, rtype)
if err == nil {
rr = rrr.(*dns.AAAA)
} else {
rr = new(dns.AAAA)
}
ip = a.AAAA
rr.(*dns.AAAA).Hdr = rheader
rr.(*dns.AAAA).AAAA = ip
}
storeRecord(rr)
}
}
}
// dnsResourceRecordToString converts a RR to a string.
func dnsResourceRecordToString(rr mkdns.RR) string {
rrHeader := rr.Header()
rrType := rrHeader.Rrtype
var data string
switch x := rr.(type) {
default:
// We don't have special handling for this type
logp.Debug("dns", "No special handling for RR type %s", dnsTypeToString(rrType))
unsupportedRR := new(mkdns.RFC3597)
err := unsupportedRR.ToRFC3597(x)
if err == nil {
rData, err := hexStringToString(unsupportedRR.Rdata)
data = rData
if err != nil {
logp.Debug("dns", "%s", err.Error())
}
} else {
logp.Debug("dns", "Rdata for the unhandled RR type %s could not be fetched", dnsTypeToString(rrType))
}
case *mkdns.A:
data = x.A.String()
case *mkdns.AAAA:
data = x.AAAA.String()
case *mkdns.CNAME:
data = x.Target
case *mkdns.MX:
data = fmt.Sprintf("preference %d, %s", x.Preference, x.Mx)
case *mkdns.NS:
data = x.Ns
case *mkdns.PTR:
data = x.Ptr
case *mkdns.RFC3597:
// Miekg/dns lib doesn't handle this type
logp.Debug("dns", "Unknown RR type %s", dnsTypeToString(rrType))
rData, err := hexStringToString(x.Rdata)
data = rData
if err != nil {
logp.Debug("dns", "%s", err.Error())
}
case *mkdns.SOA:
data = fmt.Sprintf("mname %s, rname %s, serial %d, refresh %d, "+
"retry %d, expire %d, minimum %d", x.Ns, x.Mbox,
x.Serial, x.Refresh, x.Retry, x.Expire,
x.Minttl)
case *mkdns.SRV:
data = fmt.Sprintf("priority %d, weight %d, port %d, %s", x.Priority,
x.Weight, x.Port, x.Target)
case *mkdns.TXT:
data = strings.Join(x.Txt, " ")
}
return fmt.Sprintf("%s: ttl %d, class %s, type %s, %s", rrHeader.Name,
int(rrHeader.Ttl), dnsClassToString(rrHeader.Class),
dnsTypeToString(rrType), data)
}
// AddEntry is used to add a new DNS record to this mapping
func (entry DomainEntry) AddEntry(record dns.RR) {
var header *dns.RR_Header
header = record.Header()
if _, ok := entry[header.Class]; !ok {
entry[header.Class] = make(RecordsEntry)
}
if _, ok := entry[header.Class][header.Rrtype]; !ok {
entry[header.Class][header.Rrtype] = make([]dns.RR, 0)
}
entry[header.Class][header.Rrtype] = append(entry[header.Class][header.Rrtype], record)
}
// save record
func saveRecord(rr dns.RR) (err error) {
var key string
if key, err = formatKey(rr.Header().Name, rr.Header().Rrtype); err != nil {
return
}
err = DB.Update(func(tx *bolt.Tx) error {
if err := tx.Bucket([]byte(bucket)).Put([]byte(key), []byte(rr.String())); err != nil {
return err
}
return nil
})
return err
}
func parseQuery(m *dns.Msg) {
if *debug {
Log.Printf("parseQuery: message: %+v\n", m)
}
var rr dns.RR
for _, q := range m.Question {
if readRR, e := getRecord(q.Name, q.Qtype); e == nil {
rr = readRR.(dns.RR)
if rr.Header().Name == q.Name {
m.Answer = append(m.Answer, rr)
}
}
}
}
// Delete removes rr from the tree, is the node turns empty, that node is deleted with DeleteNode.
func (t *Tree) Delete(rr dns.RR) {
if t.Root == nil {
return
}
el, _ := t.Search(rr.Header().Name, rr.Header().Rrtype)
if el == nil {
t.DeleteNode(rr)
return
}
// Delete from this element.
empty := el.Delete(rr)
if empty {
t.DeleteNode(rr)
return
}
}
// Insert inserts r into z.
func (z *Zone) Insert(r dns.RR) error {
r.Header().Name = strings.ToLower(r.Header().Name)
switch h := r.Header().Rrtype; h {
case dns.TypeNS:
r.(*dns.NS).Ns = strings.ToLower(r.(*dns.NS).Ns)
if r.Header().Name == z.origin {
z.Apex.NS = append(z.Apex.NS, r)
return nil
}
case dns.TypeSOA:
r.(*dns.SOA).Ns = strings.ToLower(r.(*dns.SOA).Ns)
r.(*dns.SOA).Mbox = strings.ToLower(r.(*dns.SOA).Mbox)
z.Apex.SOA = r.(*dns.SOA)
return nil
case dns.TypeNSEC3, dns.TypeNSEC3PARAM:
return fmt.Errorf("NSEC3 zone is not supported, dropping")
case dns.TypeRRSIG:
x := r.(*dns.RRSIG)
switch x.TypeCovered {
case dns.TypeSOA:
z.Apex.SIGSOA = append(z.Apex.SIGSOA, x)
return nil
case dns.TypeNS:
if r.Header().Name == z.origin {
z.Apex.SIGNS = append(z.Apex.SIGNS, x)
return nil
}
}
case dns.TypeCNAME:
r.(*dns.CNAME).Target = strings.ToLower(r.(*dns.CNAME).Target)
case dns.TypeMX:
r.(*dns.MX).Mx = strings.ToLower(r.(*dns.MX).Mx)
case dns.TypeSRV:
r.(*dns.SRV).Target = strings.ToLower(r.(*dns.SRV).Target)
}
z.Tree.Insert(r)
return nil
}
// Insert inserts rr into e. If rr is equal to existing rrs this is a noop.
func (e *Elem) Insert(rr dns.RR) {
t := rr.Header().Rrtype
if e.m == nil {
e.m = make(map[uint16][]dns.RR)
e.m[t] = []dns.RR{rr}
return
}
rrs, ok := e.m[t]
if !ok {
e.m[t] = []dns.RR{rr}
return
}
for _, er := range rrs {
if equalRdata(er, rr) {
return
}
}
rrs = append(rrs, rr)
e.m[t] = rrs
}
func (n *Node) delete(rr dns.RR) (root *Node, d int) {
if Less(n.Elem, rr.Header().Name) < 0 {
if n.Left != nil {
if n.Left.color() == Black && n.Left.Left.color() == Black {
n = n.moveRedLeft()
}
n.Left, d = n.Left.delete(rr)
}
} else {
if n.Left.color() == Red {
n = n.rotateRight()
}
if n.Right == nil && Less(n.Elem, rr.Header().Name) == 0 {
return nil, -1
}
if n.Right != nil {
if n.Right.color() == Black && n.Right.Left.color() == Black {
n = n.moveRedRight()
}
if Less(n.Elem, rr.Header().Name) == 0 {
n.Elem = n.Right.min().Elem
n.Right, d = n.Right.deleteMin()
} else {
n.Right, d = n.Right.delete(rr)
}
}
}
root = n.fixUp()
return
}
func (n *Node) insert(rr dns.RR) (root *Node, d int) {
if n == nil {
return &Node{Elem: newElem(rr)}, 1
} else if n.Elem == nil {
n.Elem = newElem(rr)
return n, 1
}
if Mode == TD234 {
if n.Left.color() == Red && n.Right.color() == Red {
n.flipColors()
}
}
switch c := Less(n.Elem, rr.Header().Name); {
case c == 0:
n.Elem.Insert(rr)
case c < 0:
n.Left, d = n.Left.insert(rr)
default:
n.Right, d = n.Right.insert(rr)
}
if n.Right.color() == Red && n.Left.color() == Black {
n = n.rotateLeft()
}
if n.Left.color() == Red && n.Left.Left.color() == Red {
n = n.rotateRight()
}
if Mode == BU23 {
if n.Left.color() == Red && n.Right.color() == Red {
n.flipColors()
}
}
root = n
return
}
func storeRecord(rr dns.RR) (err error) {
if *debug {
Log.Printf("Store record: resource record: %+v\n", rr)
}
key, _ := getKey(rr.Header().Name, rr.Header().Rrtype)
err = bdb.Update(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte(rrBucket))
err := b.Put([]byte(key), []byte(rr.String()))
if err != nil {
e := errors.New("Store record failed: " + rr.String())
Log.Println(e.Error())
return e
}
return nil
})
return err
}
// addRecord is used to add a new DNS record to this registry
func (r *Registry) addRecord(record dns.RR) {
var header *dns.RR_Header
header = record.Header()
var name string
name = dns.Fqdn(header.Name)
name = strings.ToLower(name)
if _, ok := r.records[name]; !ok {
r.records[name] = make(DomainEntry)
}
r.records[name].AddEntry(record)
// If this record is an SOA record then also store under the Mbox name
if header.Rrtype == dns.TypeSOA {
var soa *dns.SOA
soa = record.(*dns.SOA)
if _, ok := r.records[soa.Mbox]; !ok {
r.records[soa.Mbox] = make(DomainEntry)
}
r.records[soa.Mbox].AddEntry(record)
}
}
// Delete removes rr from e. When e is empty after the removal the returned bool is true.
func (e *Elem) Delete(rr dns.RR) (empty bool) {
if e.m == nil {
return true
}
t := rr.Header().Rrtype
rrs, ok := e.m[t]
if !ok {
return
}
for i, er := range rrs {
if equalRdata(er, rr) {
rrs = removeFromSlice(rrs, i)
e.m[t] = rrs
empty = len(rrs) == 0
if empty {
delete(e.m, t)
}
return
}
}
return
}
// Return rdata
func rdata(RR dns.RR) string {
return strings.Replace(RR.String(), RR.Header().String(), "", -1)
}
// newElem returns a new elem.
func newElem(rr dns.RR) *Elem {
e := Elem{m: make(map[uint16][]dns.RR)}
e.m[rr.Header().Rrtype] = []dns.RR{rr}
return &e
}
func rrToMapStr(rr mkdns.RR) common.MapStr {
mapStr := common.MapStr{}
rrType := rr.Header().Rrtype
switch x := rr.(type) {
default:
// We don't have special handling for this type
debugf("No special handling for RR type %s", dnsTypeToString(rrType))
unsupportedRR := new(mkdns.RFC3597)
err := unsupportedRR.ToRFC3597(x)
if err == nil {
rData, err := hexStringToString(unsupportedRR.Rdata)
mapStr["data"] = rData
if err != nil {
debugf("%s", err.Error())
}
} else {
debugf("Rdata for the unhandled RR type %s could not be fetched", dnsTypeToString(rrType))
}
case *mkdns.A:
mapStr["data"] = x.A.String()
case *mkdns.AAAA:
mapStr["data"] = x.AAAA.String()
case *mkdns.CNAME:
mapStr["data"] = x.Target
case *mkdns.DNSKEY:
mapStr["flags"] = strconv.Itoa(int(x.Flags))
mapStr["protocol"] = strconv.Itoa(int(x.Protocol))
mapStr["algorithm"] = dnsAlgorithmToString(x.Algorithm)
mapStr["data"] = x.PublicKey
case *mkdns.DS:
mapStr["key_tag"] = strconv.Itoa(int(x.KeyTag))
mapStr["algorithm"] = dnsAlgorithmToString(x.Algorithm)
mapStr["digest_type"] = dnsHashToString(x.DigestType)
mapStr["data"] = strings.ToUpper(x.Digest)
case *mkdns.MX:
mapStr["preference"] = x.Preference
mapStr["data"] = x.Mx
case *mkdns.NS:
mapStr["data"] = x.Ns
case *mkdns.NSEC:
mapStr["type_bits"] = dnsTypeBitsMapToString(x.TypeBitMap)
mapStr["data"] = x.NextDomain
case *mkdns.NSEC3:
mapStr["hash"] = dnsHashToString(x.Hash)
mapStr["flags"] = strconv.Itoa(int(x.Flags))
mapStr["iterations"] = strconv.Itoa(int(x.Iterations))
mapStr["salt"] = dnsSaltToString(x.Salt)
mapStr["type_bits"] = dnsTypeBitsMapToString(x.TypeBitMap)
mapStr["data"] = x.NextDomain
case *mkdns.NSEC3PARAM:
mapStr["hash"] = dnsHashToString(x.Hash)
mapStr["flags"] = strconv.Itoa(int(x.Flags))
mapStr["iterations"] = strconv.Itoa(int(x.Iterations))
mapStr["data"] = dnsSaltToString(x.Salt)
case *mkdns.OPT: // EDNS [RFC6891]
// OPT pseudo-RR is managed in addDnsToMapStr function
return nil
case *mkdns.PTR:
mapStr["data"] = x.Ptr
case *mkdns.RFC3597:
// Miekg/dns lib doesn't handle this type
debugf("Unknown RR type %s", dnsTypeToString(rrType))
rData, err := hexStringToString(x.Rdata)
mapStr["data"] = rData
if err != nil {
debugf("%s", err.Error())
}
case *mkdns.RRSIG:
mapStr["type_covered"] = dnsTypeToString(x.TypeCovered)
mapStr["algorithm"] = dnsAlgorithmToString(x.Algorithm)
mapStr["labels"] = strconv.Itoa(int(x.Labels))
mapStr["original_ttl"] = strconv.FormatInt(int64(x.OrigTtl), 10)
mapStr["expiration"] = mkdns.TimeToString(x.Expiration)
mapStr["inception"] = mkdns.TimeToString(x.Inception)
mapStr["key_tag"] = strconv.Itoa(int(x.KeyTag))
mapStr["signer_name"] = x.SignerName
mapStr["data"] = x.Signature
case *mkdns.SOA:
mapStr["rname"] = x.Mbox
mapStr["serial"] = x.Serial
mapStr["refresh"] = x.Refresh
mapStr["retry"] = x.Retry
mapStr["expire"] = x.Expire
mapStr["minimum"] = x.Minttl
mapStr["data"] = x.Ns
case *mkdns.SRV:
mapStr["priority"] = x.Priority
mapStr["weight"] = x.Weight
mapStr["port"] = x.Port
mapStr["data"] = x.Target
case *mkdns.TXT:
mapStr["data"] = strings.Join(x.Txt, " ")
}
return mapStr
}