[tor-commits] [snowflake/master] s/MeekChannel/BrokerChannel (close #14) and more informative TODOs
serene at torproject.org
serene at torproject.org
Mon Feb 1 05:52:05 UTC 2016
commit 678cf454cd51ab9c749ffd70debaec177e2bed54
Author: Serene Han <keroserene+git at gmail.com>
Date: Sun Jan 31 21:42:53 2016 -0800
s/MeekChannel/BrokerChannel (close #14) and more informative TODOs
---
client/meek-webrtc.go | 74 --------------------------------------------------
client/rendezvous.go | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++
client/snowflake.go | 31 ++++++++++++---------
3 files changed, 94 insertions(+), 86 deletions(-)
diff --git a/client/meek-webrtc.go b/client/meek-webrtc.go
deleted file mode 100644
index 34ff185..0000000
--- a/client/meek-webrtc.go
+++ /dev/null
@@ -1,74 +0,0 @@
-// Exchange WebRTC SessionDescriptions over a domain-fronted HTTP
-// signaling channel.
-package main
-
-import (
- "bytes"
- "io/ioutil"
- "log"
- "net/http"
- "net/url"
-
- "github.com/keroserene/go-webrtc"
-)
-
-// Meek Signalling Channel.
-type MeekChannel struct {
- // The Host header to put in the HTTP request (optional and may be
- // different from the host name in URL).
- Host string
- url *url.URL
- transport http.Transport // Used to make all requests.
-}
-
-// Construct a new MeekChannel, where:
-// |broker| is the full URL of the facilitating program which assigns proxies
-// to clients, and |front| is the option fronting domain.
-func NewMeekChannel(broker string, front string) *MeekChannel {
- targetURL, err := url.Parse(broker)
- if nil != err {
- return nil
- }
- mc := new(MeekChannel)
- mc.url = targetURL
- if "" != front { // Optional front domain.
- mc.Host = mc.url.Host
- mc.url.Host = front
- }
-
- // We make a copy of DefaultTransport because we want the default Dial
- // and TLSHandshakeTimeout settings. But we want to disable the default
- // ProxyFromEnvironment setting.
- mc.transport = *http.DefaultTransport.(*http.Transport)
- mc.transport.Proxy = nil
- return mc
-}
-
-// Roundtrip HTTP POST using WebRTC SessionDescriptions.
-//
-// Sends an SDP offer to the meek broker, which assigns a proxy and responds
-// with an SDP answer from a designated remote WebRTC peer.
-func (mc *MeekChannel) Negotiate(offer *webrtc.SessionDescription) (
- *webrtc.SessionDescription, error) {
- data := bytes.NewReader([]byte(offer.Serialize()))
- // Suffix with broker's client registration handler.
- request, err := http.NewRequest("POST", mc.url.String()+"client", data)
- if nil != err {
- return nil, err
- }
- if "" != mc.Host { // Set true host if necessary.
- request.Host = mc.Host
- }
- resp, err := mc.transport.RoundTrip(request)
- if nil != err {
- return nil, err
- }
- defer resp.Body.Close()
- log.Printf("MeekChannel Response:\n%s\n\n", resp.Status)
- body, err := ioutil.ReadAll(resp.Body)
- if nil != err {
- return nil, err
- }
- answer := webrtc.DeserializeSessionDescription(string(body))
- return answer, nil
-}
diff --git a/client/rendezvous.go b/client/rendezvous.go
new file mode 100644
index 0000000..ea0b338
--- /dev/null
+++ b/client/rendezvous.go
@@ -0,0 +1,75 @@
+// WebRTC Rendezvous requires the exchange of SessionDescriptions between
+// peers. This file contains the domain-fronted HTTP signaling mechanism
+// between the client and a desired Broker.
+package main
+
+import (
+ "bytes"
+ "io/ioutil"
+ "log"
+ "net/http"
+ "net/url"
+
+ "github.com/keroserene/go-webrtc"
+)
+
+// Signalling Channel to the Broker.
+type BrokerChannel struct {
+ // The Host header to put in the HTTP request (optional and may be
+ // different from the host name in URL).
+ Host string
+ url *url.URL
+ transport http.Transport // Used to make all requests.
+}
+
+// Construct a new BrokerChannel, where:
+// |broker| is the full URL of the facilitating program which assigns proxies
+// to clients, and |front| is the option fronting domain.
+func NewBrokerChannel(broker string, front string) *BrokerChannel {
+ targetURL, err := url.Parse(broker)
+ if nil != err {
+ return nil
+ }
+ bc := new(BrokerChannel)
+ bc.url = targetURL
+ if "" != front { // Optional front domain.
+ bc.Host = bc.url.Host
+ bc.url.Host = front
+ }
+
+ // We make a copy of DefaultTransport because we want the default Dial
+ // and TLSHandshakeTimeout settings. But we want to disable the default
+ // ProxyFromEnvironment setting.
+ bc.transport = *http.DefaultTransport.(*http.Transport)
+ bc.transport.Proxy = nil
+ return bc
+}
+
+// Roundtrip HTTP POST using WebRTC SessionDescriptions.
+//
+// Send an SDP offer to the broker, which assigns a proxy and responds
+// with an SDP answer from a designated remote WebRTC peer.
+func (bc *BrokerChannel) Negotiate(offer *webrtc.SessionDescription) (
+ *webrtc.SessionDescription, error) {
+ data := bytes.NewReader([]byte(offer.Serialize()))
+ // Suffix with broker's client registration handler.
+ request, err := http.NewRequest("POST", bc.url.String()+"client", data)
+ if nil != err {
+ return nil, err
+ }
+ if "" != bc.Host { // Set true host if necessary.
+ request.Host = bc.Host
+ }
+ resp, err := bc.transport.RoundTrip(request)
+ if nil != err {
+ return nil, err
+ }
+ defer resp.Body.Close()
+ log.Printf("BrokerChannel Response:\n%s\n\n", resp.Status)
+ body, err := ioutil.ReadAll(resp.Body)
+ if nil != err {
+ return nil, err
+ }
+ answer := webrtc.DeserializeSessionDescription(string(body))
+ return answer, nil
+}
diff --git a/client/snowflake.go b/client/snowflake.go
index 83179a3..486e602 100644
--- a/client/snowflake.go
+++ b/client/snowflake.go
@@ -1,10 +1,9 @@
-// Client transport plugin for the snowflake pluggable transport.
-//
-// TODO: Use meek for signalling.
+// Client transport plugin for the Snowflake pluggable transport.
package main
import (
"bufio"
+ "errors"
"flag"
"fmt"
"io"
@@ -16,10 +15,9 @@ import (
"syscall"
"time"
+ "git.torproject.org/pluggable-transports/goptlib.git"
"github.com/keroserene/go-webrtc"
"github.com/keroserene/go-webrtc/data"
-
- "git.torproject.org/pluggable-transports/goptlib.git"
)
var ptInfo pt.ClientInfo
@@ -93,7 +91,7 @@ func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
return fmt.Errorf("SetWriteDeadline not implemented")
}
-func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
+func dialWebRTC(config *webrtc.Configuration, broker *BrokerChannel) (
*webRTCConn, error) {
offerChan := make(chan *webrtc.SessionDescription)
@@ -131,6 +129,8 @@ func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
log.Printf("OnIceComplete")
offerChan <- pc.LocalDescription()
}
+ // This callback is not expected, as the Client initiates the creation
+ // of the data channel, not the remote peer.
pc.OnDataChannel = func(channel *data.Channel) {
log.Println("OnDataChannel")
panic("OnDataChannel")
@@ -151,6 +151,7 @@ func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
log.Println("OnClose channel")
pw.Close()
close(openChan)
+ // TODO: (Issue #12) Should attempt to renegotiate at this point.
}
dc.OnMessage = func(msg []byte) {
log.Printf("OnMessage <--- %d bytes", len(msg))
@@ -173,14 +174,14 @@ func dialWebRTC(config *webrtc.Configuration, meek *MeekChannel) (
log.Printf("----------------")
go func() {
if "" != brokerURL {
- log.Println("Sending offer via meek channel...\nTarget URL: ", brokerURL,
+ log.Println("Sending offer via BrokerChannel...\nTarget URL: ", brokerURL,
"\nFront URL: ", frontDomain)
- answer, err := meek.Negotiate(pc.LocalDescription())
+ answer, err := broker.Negotiate(pc.LocalDescription())
if nil != err {
- log.Printf("MeekChannel signaling error: %s", err)
+ log.Printf("BrokerChannel signaling error: %s", err)
}
if nil == answer {
- log.Printf("MeekChannel: No answer received.")
+ log.Printf("BrokerChannel: No answer received.")
} else {
signalChan <- answer
}
@@ -236,10 +237,16 @@ func handler(conn *pt.SocksConn) error {
}()
defer conn.Close()
+ // TODO: [#3] Fetch ICE server information from Broker.
+ // TODO: [#18] Consider TURN servers here too.
config := webrtc.NewConfiguration(
webrtc.OptionIceServer("stun:stun.l.google.com:19302"))
- meek := NewMeekChannel(brokerURL, frontDomain)
- remote, err := dialWebRTC(config, meek)
+ broker := NewBrokerChannel(brokerURL, frontDomain)
+ if nil == broker {
+ conn.Reject()
+ return errors.New("Failed to prepare BrokerChannel")
+ }
+ remote, err := dialWebRTC(config, broker)
if err != nil {
conn.Reject()
return err
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