96 lines
1.8 KiB
Go
96 lines
1.8 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"log"
|
|
"net"
|
|
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
var override_dns = map[string]bool{
|
|
"geo.hivebedrock.network.": true,
|
|
}
|
|
|
|
func answerQuery(remote net.Addr, req *dns.Msg) (reply *dns.Msg) {
|
|
reply = new(dns.Msg)
|
|
|
|
answered := false
|
|
for _, q := range req.Question {
|
|
switch q.Qtype {
|
|
case dns.TypeA:
|
|
log.Printf("Query for %s\n", q.Name)
|
|
|
|
if override_dns[q.Name] {
|
|
host, _, _ := net.SplitHostPort(remote.String())
|
|
remote_ip := net.ParseIP(host)
|
|
|
|
addrs, _ := net.InterfaceAddrs()
|
|
var ip string
|
|
for _, addr := range addrs {
|
|
if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
|
|
if ipnet.Contains(remote_ip) {
|
|
ip = ipnet.IP.String()
|
|
}
|
|
}
|
|
}
|
|
if ip == "" {
|
|
log.Panicf("query from outside of own network??")
|
|
}
|
|
|
|
rr, err := dns.NewRR(fmt.Sprintf("%s A %s", q.Name, ip))
|
|
if err == nil {
|
|
reply.Answer = append(reply.Answer, rr)
|
|
answered = true
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// forward to 1.1.1.1 if not intercepted
|
|
if !answered {
|
|
c, err := dns.DialWithTLS("tcp4", "1.1.1.1:853", nil)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
if err = c.WriteMsg(req); err != nil {
|
|
panic(err)
|
|
}
|
|
if reply, err = c.ReadMsg(); err != nil {
|
|
panic(err)
|
|
}
|
|
c.Close()
|
|
}
|
|
|
|
return reply
|
|
}
|
|
|
|
func dns_handler(w dns.ResponseWriter, req *dns.Msg) {
|
|
var reply *dns.Msg
|
|
|
|
switch req.Opcode {
|
|
case dns.OpcodeQuery:
|
|
reply = answerQuery(w.RemoteAddr(), req)
|
|
default:
|
|
reply = new(dns.Msg)
|
|
}
|
|
|
|
reply.SetReply(req)
|
|
w.WriteMsg(reply)
|
|
}
|
|
|
|
func init_dns() {
|
|
dns.HandleFunc(".", dns_handler)
|
|
|
|
server := &dns.Server{Addr: ":53", Net: "udp"}
|
|
go func() {
|
|
fmt.Printf("Starting dns at %s:53\n", GetLocalIP())
|
|
err := server.ListenAndServe()
|
|
defer server.Shutdown()
|
|
if err != nil {
|
|
log.Printf("Failed to start dns server: %s\n ", err.Error())
|
|
println("you may have to use bedrockconnect")
|
|
}
|
|
}()
|
|
}
|