a
/
badguardhome
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

+ dnsforward: support IPv6 (AAAA response) 

If question type is AAAA:
 Before this patch we responded with NXDOMAIN.
 Now we send an empty response if host rule is IPv4;
 or we send an AAAA answer if host rule is IPv6.

+ block ipv6 if rule is "0.0.0.0 blockdomain"
This commit is contained in:
Simon Zolin 2019-05-22 15:50:22 +03:00
parent 9ad4bba9ab
commit ac8f703407
2 changed files with 62 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
dnsfilter/dnsfilter.go
View File

@ -555,9 +555,18 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16) (Result, error) {
// either IPv4 or IPv4-mapped IPv6 address
res.IP = hostRule.IP.To4()
return res, nil
} else if qtype == dns.TypeAAAA && hostRule.IP.To4() == nil {
res.IP = hostRule.IP
return res, nil
} else if qtype == dns.TypeAAAA {
ip4 := hostRule.IP.To4()
if ip4 == nil {
res.IP = hostRule.IP
return res, nil
}
if bytes.Equal(ip4, []byte{0, 0, 0, 0}) {
// send IP="::" response for a rule "0.0.0.0 blockdomain"
res.IP = net.IPv6zero
return res, nil
}
}
continue

60
dnsforward/dnsforward.go
View File

@ -378,7 +378,7 @@ func (s *Server) filterDNSRequest(d *proxy.DNSContext) (*dnsfilter.Result, error
var res dnsfilter.Result
var err error
res, err = dnsFilter.CheckHost(host)
res, err = dnsFilter.CheckHost(host, d.Req.Question[0].Qtype)
if err != nil {
// Return immediately if there's an error
return nil, errorx.Decorate(err, "dnsfilter failed to check host '%s'", host)
@ -394,7 +394,7 @@ func (s *Server) filterDNSRequest(d *proxy.DNSContext) (*dnsfilter.Result, error
func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Result) *dns.Msg {
m := d.Req
if m.Question[0].Qtype != dns.TypeA {
if m.Question[0].Qtype != dns.TypeA && m.Question[0].Qtype != dns.TypeAAAA {
return s.genNXDomain(m)
}
@ -405,11 +405,25 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
return s.genBlockedHost(m, parentalBlockHost, d)
default:
if result.IP != nil {
return s.genARecord(m, result.IP)
if m.Question[0].Qtype == dns.TypeA {
return s.genARecord(m, result.IP)
} else if m.Question[0].Qtype == dns.TypeAAAA {
return s.genAAAARecord(m, result.IP)
}
// empty response
resp := dns.Msg{}
resp.SetReply(m)
return &resp
}
if s.conf.BlockingMode == "null_ip" {
return s.genARecord(m, net.IPv4zero)
switch m.Question[0].Qtype {
case dns.TypeA:
return s.genARecord(m, []byte{0, 0, 0, 0})
case dns.TypeAAAA:
return s.genAAAARecord(m, net.IPv6zero)
}
}
return s.genNXDomain(m)
@ -426,15 +440,41 @@ func (s *Server) genServerFailure(request *dns.Msg) *dns.Msg {
func (s *Server) genARecord(request *dns.Msg, ip net.IP) *dns.Msg {
resp := dns.Msg{}
resp.SetReply(request)
answer, err := dns.NewRR(fmt.Sprintf("%s %d A %s", request.Question[0].Name, s.conf.BlockedResponseTTL, ip.String()))
if err != nil {
log.Printf("Couldn't generate A record for replacement host '%s': %s", ip.String(), err)
return s.genServerFailure(request)
}
resp.Answer = append(resp.Answer, answer)
resp.Answer = append(resp.Answer, s.genAAnswer(request, ip))
return &resp
}
func (s *Server) genAAAARecord(request *dns.Msg, ip net.IP) *dns.Msg {
resp := dns.Msg{}
resp.SetReply(request)
resp.Answer = append(resp.Answer, s.genAAAAAnswer(request, ip))
return &resp
}
func (s *Server) genAAnswer(req *dns.Msg, ip net.IP) *dns.A {
answer := new(dns.A)
answer.Hdr = dns.RR_Header{
Name: req.Question[0].Name,
Rrtype: dns.TypeA,
Ttl: s.conf.BlockedResponseTTL,
Class: dns.ClassINET,
}
answer.A = ip
return answer
}
func (s *Server) genAAAAAnswer(req *dns.Msg, ip net.IP) *dns.AAAA {
answer := new(dns.AAAA)
answer.Hdr = dns.RR_Header{
Name: req.Question[0].Name,
Rrtype: dns.TypeAAAA,
Ttl: s.conf.BlockedResponseTTL,
Class: dns.ClassINET,
}
answer.AAAA = ip
return answer
}
func (s *Server) genBlockedHost(request *dns.Msg, newAddr string, d *proxy.DNSContext) *dns.Msg {
// look up the hostname, TODO: cache
replReq := dns.Msg{}