340 lines
8.2 KiB
Go
340 lines
8.2 KiB
Go
package xip
|
|
|
|
import (
|
|
"log"
|
|
"net"
|
|
"os"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
type Xip struct {
|
|
Server dns.Server
|
|
NameServers []*dns.NS
|
|
Zone string
|
|
}
|
|
|
|
type HardcodedRecord struct {
|
|
A []*dns.A
|
|
TXT *dns.TXT
|
|
MX []*dns.MX
|
|
CNAME []*dns.CNAME
|
|
}
|
|
|
|
var (
|
|
flyRegion = os.Getenv("FLY_REGION")
|
|
dottedIpV4Regex = regexp.MustCompile(`(?:^|(?:[\w\d])+\.)(((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\b){4})($|[.-])`)
|
|
dashedIpV4Regex = regexp.MustCompile(`(?:^|(?:[\w\d])+\.)(((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\-?\b){4})($|[.-])`)
|
|
hardcodedRecords = map[string]HardcodedRecord{
|
|
"ns.local-ip.sh.": {
|
|
// record holding ip addresses of ns1 and ns2
|
|
A: []*dns.A{
|
|
{A: net.IPv4(137, 66, 38, 214)},
|
|
{A: net.IPv4(213, 188, 206, 3)},
|
|
},
|
|
},
|
|
"ns1.local-ip.sh.": {
|
|
A: []*dns.A{
|
|
{A: net.IPv4(137, 66, 38, 214)}, // fly.io global ip address
|
|
},
|
|
},
|
|
"ns2.local-ip.sh.": {
|
|
A: []*dns.A{
|
|
{A: net.IPv4(213, 188, 206, 3)}, // fly.io singaporean ip address
|
|
},
|
|
},
|
|
"local-ip.sh.": {
|
|
A: []*dns.A{
|
|
{A: net.IPv4(137, 66, 53, 22)},
|
|
},
|
|
TXT: &dns.TXT{
|
|
Txt: []string{
|
|
"sl-verification=frudknyqpqlpgzbglkqnsmorfcvxrf",
|
|
"v=spf1 include:simplelogin.co ~all",
|
|
},
|
|
},
|
|
MX: []*dns.MX{
|
|
{Preference: 10, Mx: "mx1.simplelogin.co."},
|
|
{Preference: 20, Mx: "mx2.simplelogin.co."},
|
|
},
|
|
},
|
|
"_dmarc.local-ip.sh.": {
|
|
TXT: &dns.TXT{
|
|
Txt: []string{"v=DMARC1; p=quarantine; pct=100; adkim=s; aspf=s"},
|
|
},
|
|
},
|
|
"dkim._domainkey.local-ip.sh.": {
|
|
CNAME: []*dns.CNAME{
|
|
{Target: "dkim._domainkey.simplelogin.co."},
|
|
},
|
|
},
|
|
"dkim02._domainkey.local-ip.sh.": {
|
|
CNAME: []*dns.CNAME{
|
|
{Target: "dkim02._domainkey.simplelogin.co."},
|
|
},
|
|
},
|
|
"dkim03._domainkey.local-ip.sh.": {
|
|
CNAME: []*dns.CNAME{
|
|
{Target: "dkim03._domainkey.simplelogin.co."},
|
|
},
|
|
},
|
|
}
|
|
)
|
|
|
|
func (xip *Xip) fqdnToA(fqdn string) []*dns.A {
|
|
if hardcodedRecords[strings.ToLower(fqdn)].A != nil {
|
|
var records []*dns.A
|
|
|
|
for _, record := range hardcodedRecords[strings.ToLower(fqdn)].A {
|
|
records = append(records, &dns.A{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeA,
|
|
Class: dns.ClassINET,
|
|
},
|
|
A: record.A,
|
|
})
|
|
}
|
|
|
|
return records
|
|
}
|
|
|
|
for _, ipV4RE := range []*regexp.Regexp{dashedIpV4Regex, dottedIpV4Regex} {
|
|
if ipV4RE.MatchString(fqdn) {
|
|
match := ipV4RE.FindStringSubmatch(fqdn)[1]
|
|
match = strings.ReplaceAll(match, "-", ".")
|
|
ipV4Address := net.ParseIP(match).To4()
|
|
if ipV4Address == nil {
|
|
return nil
|
|
}
|
|
|
|
return []*dns.A{{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeA,
|
|
Class: dns.ClassINET,
|
|
},
|
|
A: ipV4Address,
|
|
}}
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (xip *Xip) nonExistentDomain(question dns.Question, message *dns.Msg) {
|
|
message.Rcode = dns.RcodeNameError
|
|
message.Ns = append(message.Ns, xip.SOARecord(question))
|
|
}
|
|
|
|
func (xip *Xip) handleA(question dns.Question, message *dns.Msg) {
|
|
fqdn := question.Name
|
|
records := xip.fqdnToA(fqdn)
|
|
|
|
if len(records) == 0 {
|
|
xip.nonExistentDomain(question, message)
|
|
return
|
|
}
|
|
|
|
for _, record := range records {
|
|
log.Printf("(%s) %s => %s\n", flyRegion, fqdn, record.A)
|
|
message.Answer = append(message.Answer, record)
|
|
}
|
|
}
|
|
|
|
func (xip *Xip) handleNS(question dns.Question, message *dns.Msg) {
|
|
fqdn := question.Name
|
|
nameServers := []*dns.NS{}
|
|
additionals := []*dns.A{}
|
|
for _, ns := range xip.NameServers {
|
|
nameServers = append(nameServers, &dns.NS{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeNS,
|
|
Class: dns.ClassINET,
|
|
},
|
|
Ns: ns.Ns,
|
|
})
|
|
|
|
additionals = append(additionals, xip.fqdnToA(ns.Ns)...)
|
|
}
|
|
|
|
for _, record := range nameServers {
|
|
message.Answer = append(message.Answer, record)
|
|
}
|
|
|
|
for _, record := range additionals {
|
|
message.Extra = append(message.Extra, record)
|
|
}
|
|
}
|
|
|
|
func (xip *Xip) handleTXT(question dns.Question, message *dns.Msg) {
|
|
fqdn := question.Name
|
|
if hardcodedRecords[strings.ToLower(fqdn)].TXT == nil {
|
|
xip.nonExistentDomain(question, message)
|
|
return
|
|
}
|
|
|
|
message.Answer = append(message.Answer, &dns.TXT{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeTXT,
|
|
Class: dns.ClassINET,
|
|
},
|
|
Txt: hardcodedRecords[strings.ToLower(fqdn)].TXT.Txt,
|
|
})
|
|
}
|
|
|
|
func (xip *Xip) handleMX(question dns.Question, message *dns.Msg) {
|
|
fqdn := question.Name
|
|
if hardcodedRecords[strings.ToLower(fqdn)].MX == nil {
|
|
xip.nonExistentDomain(question, message)
|
|
return
|
|
}
|
|
|
|
for _, record := range hardcodedRecords[strings.ToLower(fqdn)].MX {
|
|
message.Answer = append(message.Answer, &dns.MX{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeMX,
|
|
Class: dns.ClassINET,
|
|
},
|
|
Mx: record.Mx,
|
|
Preference: record.Preference,
|
|
})
|
|
}
|
|
}
|
|
|
|
func (xip *Xip) handleCNAME(question dns.Question, message *dns.Msg) {
|
|
fqdn := question.Name
|
|
if hardcodedRecords[strings.ToLower(fqdn)].CNAME == nil {
|
|
xip.nonExistentDomain(question, message)
|
|
return
|
|
}
|
|
|
|
for _, record := range hardcodedRecords[strings.ToLower(fqdn)].CNAME {
|
|
message.Answer = append(message.Answer, &dns.CNAME{
|
|
Hdr: dns.RR_Header{
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Name: fqdn,
|
|
Rrtype: dns.TypeCNAME,
|
|
Class: dns.ClassINET,
|
|
},
|
|
Target: record.Target,
|
|
})
|
|
}
|
|
}
|
|
|
|
func (xip *Xip) handleSOA(question dns.Question, message *dns.Msg) {
|
|
message.Answer = append(message.Answer, xip.SOARecord(question))
|
|
}
|
|
|
|
func (xip *Xip) SOARecord(question dns.Question) *dns.SOA {
|
|
soa := new(dns.SOA)
|
|
soa.Hdr = dns.RR_Header{
|
|
Name: question.Name,
|
|
Rrtype: dns.TypeSOA,
|
|
Class: dns.ClassINET,
|
|
// Ttl: uint32((time.Hour * 24 * 7).Seconds()),
|
|
Ttl: uint32((time.Second * 10).Seconds()),
|
|
Rdlength: 0,
|
|
}
|
|
soa.Ns = "ns1.local-ip.sh."
|
|
soa.Mbox = "admin.local-ip.sh."
|
|
soa.Serial = 2022102800
|
|
// soa.Refresh = uint32((time.Minute * 15).Seconds())
|
|
soa.Refresh = uint32((time.Second * 10).Seconds())
|
|
// soa.Retry = uint32((time.Minute * 15).Seconds())
|
|
soa.Retry = uint32((time.Second * 10).Seconds())
|
|
// soa.Expire = uint32((time.Minute * 30).Seconds())
|
|
soa.Expire = uint32((time.Second * 10).Seconds())
|
|
// soa.Minttl = uint32((time.Minute * 5).Seconds())
|
|
soa.Minttl = uint32((time.Second * 10).Seconds())
|
|
|
|
return soa
|
|
}
|
|
|
|
func (xip *Xip) handleQuery(message *dns.Msg) {
|
|
for _, question := range message.Question {
|
|
log.Printf("name: %s\n", question.Name)
|
|
log.Printf("class: %d\n", question.Qclass)
|
|
log.Printf("type: %d\n", question.Qtype)
|
|
switch question.Qtype {
|
|
case dns.TypeA:
|
|
xip.handleA(question, message)
|
|
case dns.TypeNS:
|
|
xip.handleNS(question, message)
|
|
case dns.TypeTXT:
|
|
xip.handleTXT(question, message)
|
|
case dns.TypeMX:
|
|
xip.handleMX(question, message)
|
|
case dns.TypeCNAME:
|
|
xip.handleCNAME(question, message)
|
|
case dns.TypeSOA:
|
|
xip.handleSOA(question, message)
|
|
default:
|
|
xip.handleSOA(question, message)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (xip *Xip) handleDnsRequest(response dns.ResponseWriter, request *dns.Msg) {
|
|
go func() {
|
|
message := new(dns.Msg)
|
|
message.SetReply(request)
|
|
message.Compress = true
|
|
message.Authoritative = true
|
|
message.RecursionAvailable = false
|
|
|
|
switch request.Opcode {
|
|
case dns.OpcodeQuery:
|
|
xip.handleQuery(message)
|
|
default:
|
|
message.MsgHdr.Rcode = dns.RcodeRefused
|
|
}
|
|
|
|
response.WriteMsg(message)
|
|
}()
|
|
}
|
|
|
|
func (xip *Xip) StartServer() {
|
|
log.Printf("Listening on %s\n", xip.Server.Addr)
|
|
err := xip.Server.ListenAndServe()
|
|
defer xip.Server.Shutdown()
|
|
if err != nil {
|
|
log.Fatalf("Failed to start server: %s\n ", err.Error())
|
|
}
|
|
}
|
|
|
|
func NewXip(zone string, nameservers []string, port int) (xip *Xip) {
|
|
xip = &Xip{}
|
|
|
|
for _, ns := range nameservers {
|
|
xip.NameServers = append(xip.NameServers, &dns.NS{Ns: ns})
|
|
}
|
|
|
|
xip.Server = dns.Server{
|
|
Addr: ":" + strconv.Itoa(port),
|
|
Net: "udp",
|
|
}
|
|
|
|
dns.HandleFunc(zone, xip.handleDnsRequest)
|
|
|
|
return xip
|
|
}
|