Update broker stats to include info on NAT types

As we now partition proxies by NAT type, our stats are more useful if they
capture how many proxies of each type we have, and information on
whether we have enough proxies of the right NAT type for our clients.
This change adds proxy counts by NAT type and binned counts of denied clients by NAT type.

broker/broker.go

@@ -165,6 +165,7 @@ func (ctx *BrokerContext) AddSnowflake(id string, proxyType string, natType stri
 	snowflake.id = id
 	snowflake.clients = 0
 	snowflake.proxyType = proxyType
+	snowflake.natType = natType
 	snowflake.offerChannel = make(chan *ClientOffer)
 	snowflake.answerChannel = make(chan []byte)
 	ctx.snowflakeLock.Lock()
@@ -201,7 +202,7 @@ func proxyPolls(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 		log.Println("Error processing proxy IP: ", err.Error())
 	} else {
 		ctx.metrics.lock.Lock()
-		ctx.metrics.UpdateCountryStats(remoteIP, proxyType)
+		ctx.metrics.UpdateCountryStats(remoteIP, proxyType, natType)
 		ctx.metrics.lock.Unlock()
 	}
 
@@ -275,6 +276,11 @@ func clientOffers(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 	if numSnowflakes <= 0 {
 		ctx.metrics.lock.Lock()
 		ctx.metrics.clientDeniedCount++
+		if offer.natType == NATUnrestricted {
+			ctx.metrics.clientUnrestrictedDeniedCount++
+		} else {
+			ctx.metrics.clientRestrictedDeniedCount++
+		}
 		ctx.metrics.lock.Unlock()
 		w.WriteHeader(http.StatusServiceUnavailable)
 		return
@@ -357,6 +363,7 @@ func proxyAnswers(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 func debugHandler(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 
 	var webexts, browsers, standalones, unknowns int
+	var natRestricted, natUnrestricted, natUnknown int
 	ctx.snowflakeLock.Lock()
 	s := fmt.Sprintf("current snowflakes available: %d\n", len(ctx.idToSnowflake))
 	for _, snowflake := range ctx.idToSnowflake {
@@ -370,12 +377,26 @@ func debugHandler(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 			unknowns++
 		}
 
+		switch snowflake.natType {
+		case NATRestricted:
+			natRestricted++
+		case NATUnrestricted:
+			natUnrestricted++
+		default:
+			natUnknown++
+		}
+
 	}
 	ctx.snowflakeLock.Unlock()
 	s += fmt.Sprintf("\tstandalone proxies: %d", standalones)
 	s += fmt.Sprintf("\n\tbrowser proxies: %d", browsers)
 	s += fmt.Sprintf("\n\twebext proxies: %d", webexts)
 	s += fmt.Sprintf("\n\tunknown proxies: %d", unknowns)
+
+	s += fmt.Sprintf("\nNAT Types available:")
+	s += fmt.Sprintf("\n\trestricted: %d", natRestricted)
+	s += fmt.Sprintf("\n\tunrestricted: %d", natUnrestricted)
+	s += fmt.Sprintf("\n\tunknown: %d", natUnknown)
 	if _, err := w.Write([]byte(s)); err != nil {
 		log.Printf("writing proxy information returned error: %v ", err)
 	}