func constrcutZones(rz rawZones, serverName string) (zones, auth, error) {
a := make(auth)
z := make(zones)
for zoneName, hosts := range rz.Zones {
zoneName = dns.Fqdn(zoneName)
soa, err := dns.NewRR(fmt.Sprintf("%s SOA %s dns.%s %s 10000 2400 604800 3600", zoneName, serverName, serverName, time.Now().Format("0601021504")))
if err != nil {
return nil, nil, err
}
z[zoneName] = map[uint16][]dns.RR{
dns.TypeSOA: []dns.RR{soa},
}
authRR, err := dns.NewRR(fmt.Sprintf("%s NS %s", zoneName, serverName))
if err != nil {
return nil, nil, fmt.Errorf("Failed to create authority NS record: %v", err)
}
for host, records := range hosts {
host = dns.Fqdn(host)
if _, present := z[host]; !present {
z[host] = make(map[uint16][]dns.RR)
}
for typeStr, v := range records {
rType, present := dns.StringToType[strings.ToUpper(typeStr)]
if !present {
return nil, nil, fmt.Errorf("Invalid record type")
}
for _, presentation := range v {
rr, err := dns.NewRR(fmt.Sprintf("%s %s %s", host, strings.ToUpper(typeStr), presentation))
if err != nil {
return nil, nil, fmt.Errorf("Couldn't parse record: %v", err)
}
z[host][rType] = append(z[host][rType], rr)
a[host] = &authRR
}
}
}
}
return z, a, nil
}
// Retrieve the DNSKEY records of a zone and convert them
// to DS records for SHA1, SHA256 and SHA384.
func ExampleDS(zone string) {
config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
c := new(dns.Client)
m := new(dns.Msg)
if zone == "" {
zone = "miek.nl"
}
m.SetQuestion(dns.Fqdn(zone), dns.TypeDNSKEY)
m.SetEdns0(4096, true)
r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
if err != nil {
return
}
if r.Rcode != dns.RcodeSuccess {
return
}
for _, k := range r.Answer {
if key, ok := k.(*dns.DNSKEY); ok {
for _, alg := range []uint8{dns.SHA1, dns.SHA256, dns.SHA384} {
fmt.Printf("%s; %d\n", key.ToDS(alg).String(), key.Flags)
}
}
}
}
func main() {
app := cli.NewApp()
app.Name = "dns-workbench"
app.Usage = "a simple authoritative DNS workbench server"
app.Authors = []cli.Author{cli.Author{Name: "Roland Shoemaker", Email: "*****@*****.**"}}
app.Version = "0.0.1"
app.Flags = []cli.Flag{}
app.Commands = []cli.Command{
{
Name: "run",
Usage: "Starts the DNS server",
Flags: []cli.Flag{
cli.StringFlag{
Name: "dns-name",
Value: "localhost",
Usage: "Hostname of the DNS server",
},
cli.StringFlag{
Name: "dns-address",
Value: "127.0.0.1",
Usage: "Address for the DNS server to listen on",
},
cli.StringFlag{
Name: "dns-port",
Value: "8053",
Usage: "Port for the DNS server to listen on",
},
cli.StringFlag{
Name: "dns-network",
Value: "udp",
Usage: "Network for the DNS server to listen on",
},
cli.BoolFlag{
Name: "dns-compression",
Usage: "Use DNS message compression",
},
cli.StringFlag{
Name: "zone-file",
Usage: "Path to workbench zones file",
},
cli.StringFlag{
Name: "api-uri",
Value: "127.0.0.1:5353",
Usage: "Address for the HTTP API to listen on",
},
cli.BoolTFlag{
Name: "disable-api",
Usage: "Don't start the HTTP API",
},
},
Action: func(c *cli.Context) {
var rz rawZones
var z zones
var a auth
var err error
logger := log.New(os.Stdout, "[dns-wb] ", log.Flags())
if rzFile := c.String("zone-file"); rzFile != "" {
rz, err = loadYAML(rzFile)
if err != nil {
logger.Fatalf("Failed to read zone file: %s\n", err)
}
z, a, err = constrcutZones(rz, dns.Fqdn(c.String("dns-name")))
if err != nil {
logger.Fatalf("Failed to parse zone file: %s\n", err)
}
} else {
z = make(zones)
a = make(auth)
}
wb := workbench{
z: z,
a: a,
l: logger,
name: dns.Fqdn(c.String("dns-name")),
bind: c.String("dns-address"),
port: c.String("dns-port"),
net: c.String("dns-network"),
rTimeout: time.Second * 2,
wTimeout: time.Second * 2,
iTimeout: time.Second * 8,
compression: c.Bool("dns-compression"),
}
go func() {
http.HandleFunc("/api/reload", wb.apiReload)
logger.Printf("API listening on %s\n", c.String("api-uri"))
err := http.ListenAndServe(c.String("api-uri"), nil)
if err != nil {
logger.Printf("HTTP API crashed: %s\n", err)
// Dont' exit
}
}()
err = wb.serveWorkbench()
if err != nil {
logger.Fatalf("DNS server crashed: %s\n", err)
os.Exit(1)
}
},
},
{
Name: "reload",
Usage: "Loads a new zone file into a running workbench",
Flags: []cli.Flag{
cli.StringFlag{
Name: "zone-file",
Usage: "Path to workbench zones file",
},
cli.StringFlag{
Name: "api-uri",
Value: "127.0.0.1:5353",
Usage: "Address for the HTTP API",
},
},
Action: func(c *cli.Context) {
logger := log.New(os.Stdout, "[dns-wb] ", log.Flags())
if c.String("zone-file") == "" {
logger.Fatalf("Zone file option is required\n")
}
rz, err := loadYAML(c.String("zone-file"))
if err != nil {
logger.Fatalf("Failed to load zone file: %s\n", err)
}
rzJSON, err := json.Marshal(rz)
if err != nil {
logger.Fatalf("Failed to marshal zone file to JSON: %s\n", err)
}
req, err := http.NewRequest("POST", fmt.Sprintf("http://%s/api/reload", c.String("api-uri")), bytes.NewBuffer(rzJSON))
req.Header.Set("Content-Type", "application/json")
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
logger.Fatalf("Failed to send update: %s\n", err)
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
apiErr, err := ioutil.ReadAll(resp.Body)
if err != nil {
logger.Fatalf("Failed to read response body: %s\n", err)
return
}
logger.Fatalf("Failed to reload zones: %s\n", apiErr)
return
}
logger.Printf("Succesesfully reloaded zones\n")
},
},
}
err := app.Run(os.Args)
if err != nil {
fmt.Println(err)
}
}