Merge branch 'issue/4' into 'master' (58edd562) · Commits · meskio / bridgestrap

cache.go

+20 −0

Original line number	Diff line number	Diff line
		@@ -47,6 +47,24 @@ func bridgeLineToAddrPort(bridgeLine string) (string, error) {
		}
		}

		// FracFunctional returns the fraction of bridges currently in the cache that
		// are functional.
		func (tc *TestCache) FracFunctional() float64 {

		if len((*tc).Entries) == 0 {
		return 0
		}

		numFunctional := 0
		for _, entry := range (*tc).Entries {
		if entry.Error == "" {
		numFunctional++
		}
		}

		return float64(numFunctional) / float64(len((*tc).Entries))
		}

		// WriteToDisk writes our test result cache to disk, allowing it to persist
		// across program restarts.
		func (tc *TestCache) WriteToDisk(cacheFile string) error {
		@@ -134,4 +152,6 @@ func (tc *TestCache) AddEntry(bridgeLine string, result error, lastTested time.T
		tc.l.Lock()
		(*tc).Entries[addrPort] = &CacheEntry{errorStr, lastTested}
		tc.l.Unlock()

		metrics.FracFunctional.Set((*tc).FracFunctional())
		}

cache_test.go

+19 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,10 @@ import (
		"time"
		)

		func init() {
		InitMetrics()
		}

		func NewCache() *TestCache {
		return &TestCache{
		Entries: make(map[string]*CacheEntry),
		@@ -55,6 +59,21 @@ func TestCacheFunctions(t *testing.T) {
		}
		}

		func TestCacheFracFunctional(t *testing.T) {

		cache := NewCache()

		cache.AddEntry("1.1.1.1:1", nil, time.Now().UTC())
		cache.AddEntry("2.2.2.2:2", nil, time.Now().UTC())
		cache.AddEntry("3.3.3.3:3", nil, time.Now().UTC())
		cache.AddEntry("4.4.4.4:4", errors.New("error"), time.Now().UTC())

		expected := 0.75
		if cache.FracFunctional() != expected {
		t.Errorf("Expected fraction %.2f but got %.2f.", expected, cache.FracFunctional())
		}
		}

		func TestCacheExpiration(t *testing.T) {

		cache := NewCache()

go.mod

+4 −4

Original line number	Diff line number	Diff line
		@@ -3,9 +3,9 @@ module gitlab.torproject.org/tpo/anti-censorship/bridgestrap
		go 1.13

		require (
		git.torproject.org/pluggable-transports/snowflake.git v0.0.0-20191213231743-37aaaffa1521
		github.com/gorilla/mux v1.7.3
		git.torproject.org/pluggable-transports/snowflake.git v0.0.0-20201120061516-ece43cbfcfc3
		github.com/gorilla/mux v1.8.0
		github.com/prometheus/client_golang v1.8.0
		github.com/yawning/bulb v0.0.0-20170405033506-85d80d893c3d
		golang.org/x/net v0.0.0-20200114155413-6afb5195e5aa // indirect
		golang.org/x/time v0.0.0-20191024005414-555d28b269f0
		golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e
		)

go.sum

+441 −5

File changed.

Preview size limit exceeded, changes collapsed.

handlers.go

+22 −5

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@ type TestResult struct {
		// TestRequest represents a client's request to test a batch of bridges.
		type TestRequest struct {
		BridgeLines []string `json:"bridge_lines"`
		resultChan chan *TestResult
		}

		// limiter implements a rate limiter. We allow 1 request per second on average
		@@ -90,21 +91,23 @@ func Index(w http.ResponseWriter, r *http.Request) {
		SendHtmlResponse(w, IndexPage)
		}

		func testBridgeLines(bridgeLines []string) *TestResult {
		func testBridgeLines(req TestRequest) TestResult {

		// Add cached bridge lines to the result.
		result := NewTestResult()
		remainingBridgeLines := []string{}
		numCached := 0
		for _, bridgeLine := range bridgeLines {
		for _, bridgeLine := range req.BridgeLines {
		if entry := cache.IsCached(bridgeLine); entry != nil {
		numCached++
		metrics.CacheHits.Inc()
		result.Bridges[bridgeLine] = &BridgeTest{
		Functional: entry.Error == "",
		LastTested: entry.Time,
		Error: entry.Error,
		}
		} else {
		metrics.CacheMisses.Inc()
		remainingBridgeLines = append(remainingBridgeLines, bridgeLine)
		}
		}
		@@ -115,12 +118,20 @@ func testBridgeLines(bridgeLines []string) *TestResult {
		numCached, len(remainingBridgeLines))

		start := time.Now()
		partialResult := torCtx.TestBridgeLines(remainingBridgeLines)
		req.resultChan = make(chan *TestResult)
		torCtx.RequestQueue <- req
		partialResult := <-req.resultChan
		result.Time = float64(time.Now().Sub(start).Seconds())
		result.Error = partialResult.Error

		// Cache partial test results and add them to our existing result object.
		for bridgeLine, bridgeTest := range partialResult.Bridges {
		cache.AddEntry(bridgeLine, errors.New(bridgeTest.Error), bridgeTest.LastTested)
		if bridgeTest.Functional {
		metrics.NumFunctionalBridges.Inc()
		} else {
		metrics.NumDysfunctionalBridges.Inc()
		}
		result.Bridges[bridgeLine] = bridgeTest
		}
		} else {
		@@ -143,11 +154,14 @@ func testBridgeLines(bridgeLines []string) *TestResult {
		numDysfunctional,
		float64(numDysfunctional)/float64(len(result.Bridges))*100)

		metrics.CacheSize.Set(float64(len(cache.Entries)))

		return result
		}

		func BridgeState(w http.ResponseWriter, r *http.Request) {

		metrics.ApiNumRequests.Inc()
		b, err := ioutil.ReadAll(r.Body)
		defer r.Body.Close()
		if err != nil {
		@@ -169,6 +183,7 @@ func BridgeState(w http.ResponseWriter, r *http.Request) {
		return
		}

		metrics.ApiNumValidRequests.Inc()
		if len(req.BridgeLines) > MaxBridgesPerReq {
		log.Printf("Got %d bridges in request but we only allow <= %d.", len(req.BridgeLines), MaxBridgesPerReq)
		http.Error(w, fmt.Sprintf("maximum of %d bridge lines allowed", MaxBridgesPerReq), http.StatusBadRequest)
		@@ -176,7 +191,7 @@ func BridgeState(w http.ResponseWriter, r *http.Request) {
		}

		log.Printf("Got %d bridge lines from %s.", len(req.BridgeLines), r.RemoteAddr)
		result := testBridgeLines(req.BridgeLines)
		result := testBridgeLines(req)

		jsonResult, err := json.Marshal(result)
		if err != nil {
		@@ -189,6 +204,7 @@ func BridgeState(w http.ResponseWriter, r *http.Request) {

		func BridgeStateWeb(w http.ResponseWriter, r *http.Request) {

		metrics.WebNumRequests.Inc()
		r.ParseForm()
		// Rate-limit Web requests to prevent someone from abusing this service
		// as a port scanner.
		@@ -202,7 +218,8 @@ func BridgeStateWeb(w http.ResponseWriter, r *http.Request) {
		return
		}

		result := testBridgeLines([]string{bridgeLine})
		metrics.WebNumValidRequests.Inc()
		result := testBridgeLines(&TestRequest{BridgeLines: []string{bridgeLine}})
		bridgeResult, exists := result.Bridges[bridgeLine]
		if !exists {
		log.Printf("Bug: Test result not part of our result map.")