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Commit 046dab86 authored by Cecylia Bocovich's avatar Cecylia Bocovich

Have broker pass client NAT type to proxy

This will allow browser-based proxies that are unable to determine their
NAT type to conservatively label themselves as restricted NATs if they
fail to work with clients that have restricted NATs.
parent 0052c0e1
......@@ -111,17 +111,17 @@ type ProxyPoll struct {
id string
proxyType string
natType string
offerChannel chan []byte
offerChannel chan *ClientOffer
}
// Registers a Snowflake and waits for some Client to send an offer,
// as part of the polling logic of the proxy handler.
func (ctx *BrokerContext) RequestOffer(id string, proxyType string, natType string) []byte {
func (ctx *BrokerContext) RequestOffer(id string, proxyType string, natType string) *ClientOffer {
request := new(ProxyPoll)
request.id = id
request.proxyType = proxyType
request.natType = natType
request.offerChannel = make(chan []byte)
request.offerChannel = make(chan *ClientOffer)
ctx.proxyPolls <- request
// Block until an offer is available, or timeout which sends a nil offer.
offer := <-request.offerChannel
......@@ -165,7 +165,7 @@ func (ctx *BrokerContext) AddSnowflake(id string, proxyType string, natType stri
snowflake.id = id
snowflake.clients = 0
snowflake.proxyType = proxyType
snowflake.offerChannel = make(chan []byte)
snowflake.offerChannel = make(chan *ClientOffer)
snowflake.answerChannel = make(chan []byte)
ctx.snowflakeLock.Lock()
if natType == NATRestricted {
......@@ -213,7 +213,7 @@ func proxyPolls(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
ctx.metrics.proxyIdleCount++
ctx.metrics.lock.Unlock()
b, err = messages.EncodePollResponse("", false)
b, err = messages.EncodePollResponse("", false, "")
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
......@@ -222,7 +222,7 @@ func proxyPolls(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
w.Write(b)
return
}
b, err = messages.EncodePollResponse(string(offer), true)
b, err = messages.EncodePollResponse(string(offer.sdp), true, offer.natType)
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
return
......@@ -232,28 +232,37 @@ func proxyPolls(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
}
}
// Client offer contains an SDP and the NAT type of the client
type ClientOffer struct {
natType string
sdp []byte
}
/*
Expects a WebRTC SDP offer in the Request to give to an assigned
snowflake proxy, which responds with the SDP answer to be sent in
the HTTP response back to the client.
*/
func clientOffers(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
var err error
startTime := time.Now()
offer, err := ioutil.ReadAll(http.MaxBytesReader(w, r.Body, readLimit))
offer := &ClientOffer{}
offer.sdp, err = ioutil.ReadAll(http.MaxBytesReader(w, r.Body, readLimit))
if nil != err {
log.Println("Invalid data.")
w.WriteHeader(http.StatusBadRequest)
return
}
natType := r.Header.Get("Snowflake-NAT-Type")
if natType == "" {
natType = NATUnknown
offer.natType = r.Header.Get("Snowflake-NAT-Type")
if offer.natType == "" {
offer.natType = NATUnknown
}
// Only hand out known restricted snowflakes to unrestricted clients
var snowflakeHeap *SnowflakeHeap
if natType == NATUnrestricted {
if offer.natType == NATUnrestricted {
snowflakeHeap = ctx.restrictedSnowflakes
} else {
snowflakeHeap = ctx.snowflakes
......
......@@ -37,7 +37,7 @@ func TestBroker(t *testing.T) {
Convey("Broker goroutine matches clients with proxies", func() {
p := new(ProxyPoll)
p.id = "test"
p.offerChannel = make(chan []byte)
p.offerChannel = make(chan *ClientOffer)
go func(ctx *BrokerContext) {
ctx.proxyPolls <- p
close(ctx.proxyPolls)
......@@ -45,23 +45,23 @@ func TestBroker(t *testing.T) {
ctx.Broker()
So(ctx.snowflakes.Len(), ShouldEqual, 1)
snowflake := heap.Pop(ctx.snowflakes).(*Snowflake)
snowflake.offerChannel <- []byte("test offer")
snowflake.offerChannel <- &ClientOffer{sdp: []byte("test offer")}
offer := <-p.offerChannel
So(ctx.idToSnowflake["test"], ShouldNotBeNil)
So(offer, ShouldResemble, []byte("test offer"))
So(offer.sdp, ShouldResemble, []byte("test offer"))
So(ctx.snowflakes.Len(), ShouldEqual, 0)
})
Convey("Request an offer from the Snowflake Heap", func() {
done := make(chan []byte)
done := make(chan *ClientOffer)
go func() {
offer := ctx.RequestOffer("test", "", NATUnknown)
done <- offer
}()
request := <-ctx.proxyPolls
request.offerChannel <- []byte("test offer")
request.offerChannel <- &ClientOffer{sdp: []byte("test offer")}
offer := <-done
So(offer, ShouldResemble, []byte("test offer"))
So(offer.sdp, ShouldResemble, []byte("test offer"))
})
Convey("Responds to client offers...", func() {
......@@ -85,7 +85,7 @@ func TestBroker(t *testing.T) {
done <- true
}()
offer := <-snowflake.offerChannel
So(offer, ShouldResemble, []byte("test"))
So(offer.sdp, ShouldResemble, []byte("test"))
snowflake.answerChannel <- []byte("fake answer")
<-done
So(w.Body.String(), ShouldEqual, "fake answer")
......@@ -104,7 +104,7 @@ func TestBroker(t *testing.T) {
done <- true
}()
offer := <-snowflake.offerChannel
So(offer, ShouldResemble, []byte("test"))
So(offer.sdp, ShouldResemble, []byte("test"))
<-done
So(w.Code, ShouldEqual, http.StatusGatewayTimeout)
})
......@@ -125,10 +125,10 @@ func TestBroker(t *testing.T) {
// Pass a fake client offer to this proxy
p := <-ctx.proxyPolls
So(p.id, ShouldEqual, "ymbcCMto7KHNGYlp")
p.offerChannel <- []byte("fake offer")
p.offerChannel <- &ClientOffer{sdp: []byte("fake offer")}
<-done
So(w.Code, ShouldEqual, http.StatusOK)
So(w.Body.String(), ShouldEqual, `{"Status":"client match","Offer":"fake offer"}`)
So(w.Body.String(), ShouldEqual, `{"Status":"client match","Offer":"fake offer","NAT":""}`)
})
Convey("return empty 200 OK when no client offer is available.", func() {
......@@ -141,7 +141,7 @@ func TestBroker(t *testing.T) {
// nil means timeout
p.offerChannel <- nil
<-done
So(w.Body.String(), ShouldEqual, `{"Status":"no match","Offer":""}`)
So(w.Body.String(), ShouldEqual, `{"Status":"no match","Offer":"","NAT":""}`)
So(w.Code, ShouldEqual, http.StatusOK)
})
})
......@@ -279,7 +279,7 @@ func TestBroker(t *testing.T) {
<-polled
So(wP.Code, ShouldEqual, http.StatusOK)
So(wP.Body.String(), ShouldResemble, `{"Status":"client match","Offer":"fake offer"}`)
So(wP.Body.String(), ShouldResemble, `{"Status":"client match","Offer":"fake offer","NAT":"unknown"}`)
So(ctx.idToSnowflake["ymbcCMto7KHNGYlp"], ShouldNotBeNil)
// Follow up with the answer request afterwards
wA := httptest.NewRecorder()
......@@ -543,7 +543,7 @@ func TestMetrics(t *testing.T) {
done <- true
}()
offer := <-snowflake.offerChannel
So(offer, ShouldResemble, []byte("test"))
So(offer.sdp, ShouldResemble, []byte("test"))
snowflake.answerChannel <- []byte("fake answer")
<-done
......
......@@ -11,7 +11,7 @@ over the offer and answer channels.
type Snowflake struct {
id string
proxyType string
offerChannel chan []byte
offerChannel chan *ClientOffer
answerChannel chan []byte
clients int
index int
......
......@@ -29,7 +29,8 @@ HTTP 200 OK
{
type: offer,
sdp: [WebRTC SDP]
}
},
NAT: ["unknown"|"restricted"|"unrestricted"]
}
2) If a client is not matched:
......@@ -120,13 +121,15 @@ func DecodePollRequest(data []byte) (string, string, string, error) {
type ProxyPollResponse struct {
Status string
Offer string
NAT string
}
func EncodePollResponse(offer string, success bool) ([]byte, error) {
func EncodePollResponse(offer string, success bool, natType string) ([]byte, error) {
if success {
return json.Marshal(ProxyPollResponse{
Status: "client match",
Offer: offer,
NAT: natType,
})
}
......@@ -135,28 +138,33 @@ func EncodePollResponse(offer string, success bool) ([]byte, error) {
})
}
// Decodes a poll response from the broker and returns an offer
// Decodes a poll response from the broker and returns an offer and the client's NAT type
// If there is a client match, the returned offer string will be non-empty
func DecodePollResponse(data []byte) (string, error) {
func DecodePollResponse(data []byte) (string, string, error) {
var message ProxyPollResponse
err := json.Unmarshal(data, &message)
if err != nil {
return "", err
return "", "", err
}
if message.Status == "" {
return "", fmt.Errorf("received invalid data")
return "", "", fmt.Errorf("received invalid data")
}
if message.Status == "client match" {
if message.Offer == "" {
return "", fmt.Errorf("no supplied offer")
return "", "", fmt.Errorf("no supplied offer")
}
} else {
message.Offer = ""
}
return message.Offer, nil
natType := message.NAT
if natType == "" {
natType = "unknown"
}
return message.Offer, natType, nil
}
type ProxyAnswerRequest struct {
......
......@@ -109,7 +109,7 @@ func TestDecodeProxyPollResponse(t *testing.T) {
}{
{
"fake offer",
`{"Status":"client match","Offer":"fake offer"}`,
`{"Status":"client match","Offer":"fake offer","NAT":"unknown"}`,
nil,
},
{
......@@ -128,9 +128,9 @@ func TestDecodeProxyPollResponse(t *testing.T) {
fmt.Errorf(""),
},
} {
offer, err := DecodePollResponse([]byte(test.data))
So(offer, ShouldResemble, test.offer)
offer, _, err := DecodePollResponse([]byte(test.data))
So(err, ShouldHaveSameTypeAs, test.err)
So(offer, ShouldResemble, test.offer)
}
})
......@@ -138,16 +138,18 @@ func TestDecodeProxyPollResponse(t *testing.T) {
func TestEncodeProxyPollResponse(t *testing.T) {
Convey("Context", t, func() {
b, err := EncodePollResponse("fake offer", true)
b, err := EncodePollResponse("fake offer", true, "restricted")
So(err, ShouldEqual, nil)
offer, err := DecodePollResponse(b)
offer, natType, err := DecodePollResponse(b)
So(offer, ShouldEqual, "fake offer")
So(natType, ShouldEqual, "restricted")
So(err, ShouldEqual, nil)
b, err = EncodePollResponse("", false)
b, err = EncodePollResponse("", false, "unknown")
So(err, ShouldEqual, nil)
offer, err = DecodePollResponse(b)
offer, natType, err = DecodePollResponse(b)
So(offer, ShouldEqual, "")
So(natType, ShouldEqual, "unknown")
So(err, ShouldEqual, nil)
})
}
......
......@@ -249,7 +249,7 @@ func TestBrokerInteractions(t *testing.T) {
Convey("polls broker correctly", func() {
var err error
b, err := messages.EncodePollResponse(sampleOffer, true)
b, err := messages.EncodePollResponse(sampleOffer, true, "unknown")
So(err, ShouldEqual, nil)
broker.transport = &MockTransport{
http.StatusOK,
......
......@@ -201,7 +201,7 @@ func (b *Broker) pollOffer(sid string) *webrtc.SessionDescription {
log.Printf("error reading broker response: %s", err)
} else {
offer, err := messages.DecodePollResponse(body)
offer, _, err := messages.DecodePollResponse(body)
if err != nil {
log.Printf("error reading broker response: %s", err.Error())
log.Printf("body: %s", body)
......
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