dnscontrol/providers/bind/bindProvider.go
Tom Limoncelli e563c53658 PTR should handle "Classless in-addr.arpa delegation" RFC2317 (#149)
* Handle IPv4 "Classless in-addr.arpa delegation" RFC2317 (partial).
* Validate PTR name when in RFC2317 "Classless in-addr.arpa delegation" domains.
* Update docs
* Set CanUsePTR for Route53 and Google CloudDNS.
* BIND: Replace "/" with "_" in filenames.
2017-07-10 19:24:55 -04:00

277 lines
7.3 KiB
Go

package bind
/*
bind -
Generate zonefiles suitiable for BIND.
The zonefiles are read and written to the directory -bind_dir
If the old zonefiles are readable, we read them to determine
if an update is actually needed. The old zonefile is also used
as the basis for generating the new SOA serial number.
*/
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"log"
"os"
"path/filepath"
"strings"
"github.com/miekg/dns"
"github.com/miekg/dns/dnsutil"
"github.com/StackExchange/dnscontrol/models"
"github.com/StackExchange/dnscontrol/providers"
"github.com/StackExchange/dnscontrol/providers/diff"
)
func initBind(config map[string]string, providermeta json.RawMessage) (providers.DNSServiceProvider, error) {
// config -- the key/values from creds.json
// meta -- the json blob from NewReq('name', 'TYPE', meta)
api := &Bind{}
if len(providermeta) != 0 {
err := json.Unmarshal(providermeta, api)
if err != nil {
return nil, err
}
}
api.nameservers = models.StringsToNameservers(api.DefaultNS)
return api, nil
}
func init() {
providers.RegisterDomainServiceProviderType("BIND", initBind, providers.CanUsePTR)
}
type SoaInfo struct {
Ns string `json:"master"`
Mbox string `json:"mbox"`
Serial uint32 `json:"serial"`
Refresh uint32 `json:"refresh"`
Retry uint32 `json:"retry"`
Expire uint32 `json:"expire"`
Minttl uint32 `json:"minttl"`
}
func (s SoaInfo) String() string {
return fmt.Sprintf("%s %s %d %d %d %d %d", s.Ns, s.Mbox, s.Serial, s.Refresh, s.Retry, s.Expire, s.Minttl)
}
type Bind struct {
DefaultNS []string `json:"default_ns"`
DefaultSoa SoaInfo `json:"default_soa"`
nameservers []*models.Nameserver
}
var bindBaseDir = flag.String("bindtree", "zones", "BIND: Directory that stores BIND zonefiles.")
//var bindSkeletin = flag.String("bind_skeletin", "skeletin/master/var/named/chroot/var/named/master", "")
func rrToRecord(rr dns.RR, origin string, replaceSerial uint32) (models.RecordConfig, uint32) {
// Convert's dns.RR into our native data type (models.RecordConfig).
// Records are translated directly with no changes.
// If it is an SOA for the apex domain and
// replaceSerial != 0, change the serial to replaceSerial.
// WARNING(tlim): This assumes SOAs do not have serial=0.
// If one is found, we replace it with serial=1.
var old_serial, new_serial uint32
header := rr.Header()
rc := models.RecordConfig{}
rc.Type = dns.TypeToString[header.Rrtype]
rc.NameFQDN = strings.ToLower(strings.TrimSuffix(header.Name, "."))
rc.Name = strings.ToLower(dnsutil.TrimDomainName(header.Name, origin))
rc.TTL = header.Ttl
switch v := rr.(type) {
case *dns.A:
rc.Target = v.A.String()
case *dns.AAAA:
rc.Target = v.AAAA.String()
case *dns.CNAME:
rc.Target = v.Target
case *dns.MX:
rc.Target = v.Mx
rc.Priority = v.Preference
case *dns.NS:
rc.Target = v.Ns
case *dns.PTR:
rc.Target = v.Ptr
case *dns.SOA:
old_serial = v.Serial
if old_serial == 0 {
// For SOA records, we never return a 0 serial number.
old_serial = 1
}
new_serial = v.Serial
if rc.Name == "@" && replaceSerial != 0 {
new_serial = replaceSerial
}
rc.Target = fmt.Sprintf("%v %v %v %v %v %v %v",
v.Ns, v.Mbox, new_serial, v.Refresh, v.Retry, v.Expire, v.Minttl)
case *dns.TXT:
rc.Target = strings.Join(v.Txt, " ")
default:
log.Fatalf("Unimplemented zone record type=%s (%v)\n", rc.Type, rr)
}
return rc, old_serial
}
func makeDefaultSOA(info SoaInfo, origin string) *models.RecordConfig {
// Make a default SOA record in case one isn't found:
soaRec := models.RecordConfig{
Type: "SOA",
Name: "@",
}
soaRec.NameFQDN = dnsutil.AddOrigin(soaRec.Name, origin)
//TODO(cpeterson): are these sane defaults?
if len(info.Ns) == 0 {
info.Ns = "DEFAULT_NOT_SET"
}
if len(info.Mbox) == 0 {
info.Mbox = "DEFAULT_NOT_SET"
}
if info.Serial == 0 {
info.Serial = 1
}
if info.Refresh == 0 {
info.Refresh = 3600
}
if info.Retry == 0 {
info.Retry = 600
}
if info.Expire == 0 {
info.Expire = 604800
}
if info.Minttl == 0 {
info.Minttl = 1440
}
soaRec.Target = info.String()
return &soaRec
}
func (c *Bind) GetNameservers(string) ([]*models.Nameserver, error) {
return c.nameservers, nil
}
func (c *Bind) GetDomainCorrections(dc *models.DomainConfig) ([]*models.Correction, error) {
dc.Punycode()
// Phase 1: Copy everything to []*models.RecordConfig:
// expectedRecords < dc.Records[i]
// foundRecords < zonefile
//
// Phase 2: Do any manipulations:
// add NS
// manipulate SOA
//
// Phase 3: Convert to []diff.Records and compare:
// expectedDiffRecords < expectedRecords
// foundDiffRecords < foundRecords
// diff.Inc...(foundDiffRecords, expectedDiffRecords )
// Default SOA record. If we see one in the zone, this will be replaced.
soaRec := makeDefaultSOA(c.DefaultSoa, dc.Name)
// Read foundRecords:
foundRecords := make([]*models.RecordConfig, 0)
var oldSerial, newSerial uint32
zonefile := filepath.Join(*bindBaseDir, strings.Replace(strings.ToLower(dc.Name), "/", "_", -1)+".zone")
foundFH, err := os.Open(zonefile)
zoneFileFound := err == nil
if err != nil && !os.IsNotExist(os.ErrNotExist) {
// Don't whine if the file doesn't exist. However all other
// errors will be reported.
fmt.Printf("Could not read zonefile: %v\n", err)
} else {
for x := range dns.ParseZone(foundFH, dc.Name, zonefile) {
if x.Error != nil {
log.Println("Error in zonefile:", x.Error)
} else {
rec, serial := rrToRecord(x.RR, dc.Name, oldSerial)
if serial != 0 && oldSerial != 0 {
log.Fatalf("Multiple SOA records in zonefile: %v\n", zonefile)
}
if serial != 0 {
// This was an SOA record. Update the serial.
oldSerial = serial
newSerial = generate_serial(oldSerial)
// Regenerate with new serial:
*soaRec, _ = rrToRecord(x.RR, dc.Name, newSerial)
rec = *soaRec
}
foundRecords = append(foundRecords, &rec)
}
}
}
// Add SOA record to expected set:
if !dc.HasRecordTypeName("SOA", "@") {
dc.Records = append(dc.Records, soaRec)
}
differ := diff.New(dc)
_, create, del, mod := differ.IncrementalDiff(foundRecords)
buf := &bytes.Buffer{}
// Print a list of changes. Generate an actual change that is the zone
changes := false
for _, i := range create {
changes = true
if zoneFileFound {
fmt.Fprintln(buf, i)
}
}
for _, i := range del {
changes = true
if zoneFileFound {
fmt.Fprintln(buf, i)
}
}
for _, i := range mod {
changes = true
if zoneFileFound {
fmt.Fprintln(buf, i)
}
}
msg := fmt.Sprintf("GENERATE_ZONEFILE: %s\n", dc.Name)
if !zoneFileFound {
msg = msg + fmt.Sprintf(" (%d records)\n", len(create))
}
msg += buf.String()
corrections := []*models.Correction{}
if changes {
corrections = append(corrections,
&models.Correction{
Msg: msg,
F: func() error {
fmt.Printf("CREATING ZONEFILE: %v\n", zonefile)
zf, err := os.Create(zonefile)
if err != nil {
log.Fatalf("Could not create zonefile: %v", err)
}
zonefilerecords := make([]dns.RR, 0, len(dc.Records))
for _, r := range dc.Records {
zonefilerecords = append(zonefilerecords, r.ToRR())
}
err = WriteZoneFile(zf, zonefilerecords, dc.Name)
if err != nil {
log.Fatalf("WriteZoneFile error: %v\n", err)
}
err = zf.Close()
if err != nil {
log.Fatalf("Closing: %v", err)
}
return nil
},
})
}
return corrections, nil
}