[tor-commits] [snowflake/master] add --meek flag to client to toggle the domain fronted rendezvous
arlo at torproject.org
arlo at torproject.org
Wed Jan 20 02:28:44 UTC 2016
commit b4a07c4192841ded1906e3e74a5e4fec6b5c3f65
Author: Serene Han <keroserene+git at gmail.com>
Date: Tue Jan 19 17:21:07 2016 -0800
add --meek flag to client to toggle the domain fronted rendezvous
---
README.md | 7 +++++++
client/meek-webrtc.go | 34 +++++++++++++++-------------------
client/snowflake.go | 46 +++++++++++++++++++++++-----------------------
3 files changed, 45 insertions(+), 42 deletions(-)
diff --git a/README.md b/README.md
index 7b6ca9f..f0b7678 100644
--- a/README.md
+++ b/README.md
@@ -88,4 +88,11 @@ snowflake to just use a default relay.
### More
+To try using the Meek signaling channel (which will soon be fully ready),
+add the `--meek` flag like so:
+
+```
+ClientTransportPlugin snowflake exec ./client --meek
+```
+
More documentation on the way.
diff --git a/client/meek-webrtc.go b/client/meek-webrtc.go
index 927d4bf..172c1b5 100644
--- a/client/meek-webrtc.go
+++ b/client/meek-webrtc.go
@@ -1,5 +1,5 @@
-// Exchange WebRTC SessionDescriptions over meek.
-// Much of this source is extracted from meek-client.go.
+// Exchange WebRTC SessionDescriptions over a domain-fronted HTTP
+// signalling channel.
package main
import (
@@ -16,29 +16,26 @@ import (
// roundtrip, including variables that may come from SOCKS args or from the
// command line.
type RequestInfo struct {
- // What to put in the X-Session-ID header.
- // SessionID string
- // The URL to request.
+ // What to put in the X-Session-ID header - SessionID string
+ // The desired potentially filtered URL to request.
URL *url.URL
// The Host header to put in the HTTP request (optional and may be
// different from the host name in URL).
Host string
}
-func NewRequestInfo(meekUrl string, front string) *RequestInfo {
+func NewRequestInfo(targetUrl string, front string) *RequestInfo {
info := new(RequestInfo)
- requestUrl, err := url.Parse(meekUrl)
+ requestUrl, err := url.Parse(targetUrl)
if nil != err {
return nil
}
info.URL = requestUrl
info.Host = front
- // info.URL.Host = front
- // info.Host = info.URL.Host
return info
}
-// Meek Signalling Channel
+// Meek Signalling Channel.
type MeekChannel struct {
info *RequestInfo
// Used to make all requests.
@@ -58,24 +55,23 @@ func NewMeekChannel(info *RequestInfo) *MeekChannel {
}
// Do an HTTP roundtrip using the payload data in buf.
-func (m *MeekChannel) roundTripHTTP(buf []byte) (*http.Response, error) {
+func (mc *MeekChannel) roundTripHTTP(buf []byte) (*http.Response, error) {
// Compose an innocent looking request.
- req, err := http.NewRequest("POST", m.info.Host+"/reg/123", bytes.NewReader(buf))
+ req, err := http.NewRequest("POST", mc.info.Host+"/reg/123", bytes.NewReader(buf))
if nil != err {
return nil, err
}
- // Set actually desired target host.
- req.Host = m.info.URL.String()
+ // Set actually desired host in the request.
+ req.Host = mc.info.URL.String()
// req.Header.Set("X-Session-Id", m.info.SessionID)
- return m.transport.RoundTrip(req)
+ return mc.transport.RoundTrip(req)
}
// Send an SDP offer to the meek facilitator, and wait for an SDP answer from
// the assigned proxy in the response.
-func (m *MeekChannel) Negotiate(offer *webrtc.SessionDescription) (
+func (mc *MeekChannel) Negotiate(offer *webrtc.SessionDescription) (
*webrtc.SessionDescription, error) {
- buf := []byte(offer.Serialize())
- resp, err := m.roundTripHTTP(buf)
+ resp, err := mc.roundTripHTTP([]byte(offer.Serialize()))
if nil != err {
return nil, err
}
@@ -85,11 +81,11 @@ func (m *MeekChannel) Negotiate(offer *webrtc.SessionDescription) (
if nil != err {
return nil, err
}
- log.Println("MeekChannel Body: ", string(body))
answer := webrtc.DeserializeSessionDescription(string(body))
return answer, nil
}
+
// Simple interim non-fronting HTTP POST negotiation, to be removed when more
// general fronting is present.
func sendOfferHTTP(url string, offer *webrtc.SessionDescription) (*webrtc.SessionDescription, error) {
diff --git a/client/snowflake.go b/client/snowflake.go
index 7da1e15..cf08c9e 100644
--- a/client/snowflake.go
+++ b/client/snowflake.go
@@ -25,14 +25,15 @@ import (
// Hard-coded meek signalling channel for now.
// TODO: expose as param
const (
- MEEK_URL = "snowflake-reg.appspot.com"
- FRONT_DOMAIN = "https://www.google.com"
- // FRONT_DOMAIN = "https://www.google.com"
+ // Go fully requires the protocol to make url spec
+ FRONT_URL = "https://www.google.com"
+ BROKER_URL = "snowflake-reg.appspot.com"
)
var ptInfo pt.ClientInfo
var logFile *os.File
var offerURL string
+var meekEnabled bool
// When a connection handler starts, +1 is written to this channel; when it
// ends, -1 is written.
@@ -160,7 +161,6 @@ func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
close(openChan)
}
dc.OnMessage = func(msg []byte) {
- // log.Printf("OnMessage channel %d %+q", len(msg), msg)
log.Printf("OnMessage <--- %d bytes", len(msg))
n, err := pw.Write(msg)
if err != nil {
@@ -180,20 +180,22 @@ func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
fmt.Fprintln(logFile, "\n"+offer.Serialize()+"\n")
log.Printf("----------------")
go func() {
- // log.Printf("Sending offer via meek...")
- // answer, err := meek.Negotiate(pc.LocalDescription())
- // if nil != err {
- // log.Printf("Signalling error: %s", err)
- // }
- // if nil == answer {
- // log.Printf("No answer received from meek channel.")
- // } else {
- // // TODO: Once this is correct, uncomment and remove copy-paste
- // // signalling.
- // log.Println("Recieved answer from Meek channel: \n",
- // answer.Serialize())
- // // signalChan <- answer
- // }
+ if meekEnabled {
+ log.Println("Sending offer via meek channel...\nTarget URL: ", BROKER_URL,
+ "\nFront URL: ", FRONT_URL)
+ answer, err := meek.Negotiate(pc.LocalDescription())
+ if nil != err {
+ log.Printf("MeekChannel signaling error: %s", err)
+ }
+ if nil == answer {
+ log.Printf("MeekChannel: No answer received.")
+ } else {
+ log.Println("Recieved answer from Meek channel: \n\n",
+ answer.Serialize(), "\n")
+ // TODO: Once this is correct, uncomment and remove copy-paste stuff.
+ // signalChan <- answer
+ }
+ }
if offerURL != "" {
answer, err := sendOfferHTTP(offerURL, offer)
if err != nil {
@@ -253,15 +255,12 @@ func handler(conn *pt.SocksConn) error {
}()
defer conn.Close()
- // go func() {
- // }()
// Prepare meek signalling channel.
- info := NewRequestInfo(MEEK_URL, FRONT_DOMAIN)
+ info := NewRequestInfo(BROKER_URL, FRONT_URL)
meek := NewMeekChannel(info)
config := webrtc.NewConfiguration(
webrtc.OptionIceServer("stun:stun.l.google.com:19302"))
- // remote, err := dialWebRTC(config, nil)
remote, err := dialWebRTC(config, meek)
if err != nil {
conn.Reject()
@@ -322,7 +321,8 @@ func readSignalingMessages(f *os.File) {
func main() {
var err error
- flag.StringVar(&offerURL, "url", "", "do signaling through URL")
+ flag.StringVar(&offerURL, "url", "", "do signalling through URL")
+ flag.BoolVar(&meekEnabled, "meek", false, "use domain fronted signaling")
flag.Parse()
logFile, err = os.OpenFile("snowflake.log", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
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