ambrose
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dns64
mirror of https://github.com/serverwentdown/dns64.git
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Improve RFC compatibility and cleanup

pull/4/head
Ambrose Chua 2017-12-24 03:45:11 +08:00
parent 7cd9e7ec7e
commit 6efd8958b6
Signed by: ambrose
GPG Key ID: B34FBE029276BA5D
2 changed files with 26 additions and 27 deletions
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51
dns64.go
View File

@ -41,41 +41,40 @@ type ResponseWriter struct {
// WriteMsg implements the dns.ResponseWriter interface.
func (r *ResponseWriter) WriteMsg(res *dns.Msg) error {
// Only respond with this when the request came in over IPv6.
v4 := false
if ip, ok := r.RemoteAddr().(*net.UDPAddr); ok {
v4 = ip.IP.To4() != nil
}
if ip, ok := r.RemoteAddr().(*net.TCPAddr); ok {
v4 = ip.IP.To4() != nil
}
if v4 { // if it came in over v4, don't do anything.
return r.ResponseWriter.WriteMsg(res)
}
ty, _ := response.Typify(res, time.Now().UTC())
if ty != response.NoData {
return r.ResponseWriter.WriteMsg(res)
}
// Make request to upstream
state := request.Request{W: r, Req: res}
// only respond with this when the request came in over IPv6.
if state.Family() == 1 { // if it came in over v4, don't do anything.
return r.ResponseWriter.WriteMsg(res)
}
// do not modify if query is not AAAA or not of class IN.
if state.QType() != dns.TypeAAAA || state.QClass() != dns.ClassINET {
return r.ResponseWriter.WriteMsg(res)
}
// do not modify if there are AAAA records or NameError. continue if NoData or any other error.
ty, _ := response.Typify(res, time.Now().UTC())
if ty == response.NoError || ty == response.NameError {
return r.ResponseWriter.WriteMsg(res)
}
// perform request to upstream.
res2, err := r.Proxy.Lookup(state, state.Name(), dns.TypeA)
if err != nil {
log.Printf("[WARNING] Unable to query upstream DNS: %v", err)
log.Printf("[WARNING] Unable to query upstream DNS: %v", err)
res.MsgHdr.Rcode = dns.RcodeServerFailure
return r.ResponseWriter.WriteMsg(res)
}
// Modify response
// modify response.
res.MsgHdr.Rcode = dns.RcodeSuccess
res.Answer = res2.Answer
for i := 0; i < len(res.Answer); i++ {
ans := res.Answer[i]
hdr := ans.Header()
if hdr.Rrtype == dns.TypeA {
aaaa, err := To6(r.Prefix, ans.(*dns.A).A)
if err != nil {
log.Printf("[ERROR] %v", err)
}
aaaa, _ := To6(r.Prefix, ans.(*dns.A).A)
res.Answer[i] = &dns.AAAA{
Hdr: dns.RR_Header{
Name: hdr.Name,
@ -92,7 +91,7 @@ func (r *ResponseWriter) WriteMsg(res *dns.Msg) error {
// Write implements the dns.ResponseWriter interface.
func (r *ResponseWriter) Write(buf []byte) (int, error) {
log.Printf("[WARNING] Dns64 called with Write: not performing DNS64")
log.Printf("[WARNING] DNS64 called with Write: not performing DNS64")
n, err := r.ResponseWriter.Write(buf)
return n, err
}
@ -111,7 +110,7 @@ func To6(prefix *net.IPNet, addr net.IP) (net.IP, error) {
}
n, _ := prefix.Mask.Size()
// Assumes prefix has been validated during setup
// assumes prefix has been validated during setup
v6 := make([]byte, 16)
i, j := 0, 0

2
setup.go
View File

@ -59,7 +59,7 @@ func dns64Parse(c *caddy.Controller) (proxy.Proxy, *net.IPNet, error) {
}
_, pref, err := net.ParseCIDR(c.Val())
// Test for valid prefix
// test for valid prefix
n, total := pref.Mask.Size()
if total != 128 {
return prxy, pref, c.Errf("'%s' not a valid IPv6 address", pref)