tailscale/wgengine/tsdns/tsdns_server_test.go

89 lines
2.0 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tsdns
import (
"github.com/miekg/dns"
"inet.af/netaddr"
)
// This file exists to isolate the test infrastructure
// that depends on github.com/miekg/dns
// from the rest, which only depends on dnsmessage.
var dnsHandleFunc = dns.HandleFunc
// resolveToIP returns a handler function which responds
// to queries of type A it receives with an A record containing ipv4,
// to queries of type AAAA with an AAAA record containing ipv6,
// to queries of type NS with an NS record containg name.
func resolveToIP(ipv4, ipv6 netaddr.IP, ns string) dns.HandlerFunc {
return func(w dns.ResponseWriter, req *dns.Msg) {
m := new(dns.Msg)
m.SetReply(req)
if len(req.Question) != 1 {
panic("not a single-question request")
}
question := req.Question[0]
var ans dns.RR
switch question.Qtype {
case dns.TypeA:
ans = &dns.A{
Hdr: dns.RR_Header{
Name: question.Name,
Rrtype: dns.TypeA,
Class: dns.ClassINET,
},
A: ipv4.IPAddr().IP,
}
case dns.TypeAAAA:
ans = &dns.AAAA{
Hdr: dns.RR_Header{
Name: question.Name,
Rrtype: dns.TypeAAAA,
Class: dns.ClassINET,
},
AAAA: ipv6.IPAddr().IP,
}
case dns.TypeNS:
ans = &dns.NS{
Hdr: dns.RR_Header{
Name: question.Name,
Rrtype: dns.TypeNS,
Class: dns.ClassINET,
},
Ns: ns,
}
}
m.Answer = append(m.Answer, ans)
w.WriteMsg(m)
}
}
func resolveToNXDOMAIN(w dns.ResponseWriter, req *dns.Msg) {
m := new(dns.Msg)
m.SetRcode(req, dns.RcodeNameError)
w.WriteMsg(m)
}
func serveDNS(addr string) (*dns.Server, chan error) {
server := &dns.Server{Addr: addr, Net: "udp"}
waitch := make(chan struct{})
server.NotifyStartedFunc = func() { close(waitch) }
errch := make(chan error, 1)
go func() {
errch <- server.ListenAndServe()
close(errch)
}()
<-waitch
return server, errch
}