bump snap version

Tunnels exp backoff

README.md

@@ -156,6 +156,8 @@ zagent248.hola.org,165.22.65.3,22222,22223,22224,22225,22226,digitalocean
 
 | Argument | Type | Description |
 | -------- | ---- | ----------- |
+| backoff-deadline | Duration | total duration of zgettunnels method attempts (default 5m0s) |
+| backoff-initial | Duration | initial average backoff delay for zgettunnels (randomized by +/-50%) (default 3s) |
 | bind-address | String | HTTP proxy address to listen to (default "127.0.0.1:8080") |
 | cafile | String | use custom CA certificate bundle file |
 | country | String | desired proxy location (default "us") |

credservice.go

@@ -12,9 +12,10 @@ const DEFAULT_LIST_LIMIT = 3
 func CredService(interval, timeout time.Duration,
 	country string,
 	proxytype string,
-	logger *CondLogger) (auth AuthProvider,
-	tunnels *ZGetTunnelsResponse,
-	err error) {
+	logger *CondLogger,
+	backoffInitial time.Duration,
+	backoffDeadline time.Duration,
+) (auth AuthProvider, tunnels *ZGetTunnelsResponse, err error) {
 	var mux sync.Mutex
 	var auth_header, user_uuid string
 	auth = func() (res string) {
@@ -25,7 +26,8 @@ func CredService(interval, timeout time.Duration,
 	}
 
 	tx_res, tx_err := EnsureTransaction(context.Background(), timeout, func(ctx context.Context, client *http.Client) bool {
-		tunnels, user_uuid, err = Tunnels(ctx, logger, client, country, proxytype, DEFAULT_LIST_LIMIT)
+		tunnels, user_uuid, err = Tunnels(ctx, logger, client, country, proxytype,
+			DEFAULT_LIST_LIMIT, timeout, backoffInitial, backoffDeadline)
 		if err != nil {
 			logger.Error("Configuration bootstrap error: %v. Retrying with the fallback mechanism...", err)
 			return false
@@ -55,7 +57,8 @@ func CredService(interval, timeout time.Duration,
 			<-ticker.C
 			logger.Info("Rotating credentials...")
 			tx_res, tx_err := EnsureTransaction(context.Background(), timeout, func(ctx context.Context, client *http.Client) bool {
-				tuns, user_uuid, err = Tunnels(ctx, logger, client, country, proxytype, DEFAULT_LIST_LIMIT)
+				tuns, user_uuid, err = Tunnels(ctx, logger, client, country, proxytype,
+					DEFAULT_LIST_LIMIT, timeout, backoffInitial, backoffDeadline)
 				if err != nil {
 					logger.Error("Credential rotation error: %v. Retrying with the fallback mechanism...", err)
 					return false

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/ameshkov/dnsstamps v1.0.3 // indirect
 	github.com/beefsack/go-rate v0.0.0-20220214233405-116f4ca011a0 // indirect
 	github.com/bluele/gcache v0.0.2 // indirect
+	github.com/cenkalti/backoff/v4 v4.2.0 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
 	github.com/golang/mock v1.6.0 // indirect
 	github.com/google/pprof v0.0.0-20230131232505-5a9e8f65f08f // indirect

go.sum

@@ -20,6 +20,8 @@ github.com/bluele/gcache v0.0.2 h1:WcbfdXICg7G/DGBh1PFfcirkWOQV+v077yF1pSy3DGw=
 github.com/bluele/gcache v0.0.2/go.mod h1:m15KV+ECjptwSPxKhOhQoAFQVtUFjTVkc3H8o0t/fp0=
 github.com/campoy/unique v0.0.0-20180121183637-88950e537e7e h1:V9a67dfYqPLAvzk5hMQOXYJlZ4SLIXgyKIE+ZiHzgGQ=
 github.com/campoy/unique v0.0.0-20180121183637-88950e537e7e/go.mod h1:9IOqJGCPMSc6E5ydlp5NIonxObaeu/Iub/X03EKPVYo=
+github.com/cenkalti/backoff/v4 v4.2.0 h1:HN5dHm3WBOgndBH6E8V0q2jIYIR3s9yglV8k/+MN3u4=
+github.com/cenkalti/backoff/v4 v4.2.0/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=

holaapi.go

@@ -20,6 +20,7 @@ import (
 	"time"
 
 	"github.com/campoy/unique"
+	"github.com/cenkalti/backoff/v4"
 	"github.com/google/uuid"
 )
 
@@ -35,11 +36,9 @@ const LOGIN_PREFIX = "user-uuid-"
 const FALLBACK_CONF_URL = "https://www.dropbox.com/s/jemizcvpmf2qb9v/cloud_failover.conf?dl=1"
 const AGENT_SUFFIX = ".hola.org"
 
-const MinTunnelsPause = 10 * time.Second
-const MaxTunnelsPause = 25 * time.Second
-
 var TemporaryBanError = errors.New("temporary ban detected")
 var PermanentBanError = errors.New("permanent ban detected")
+var EmptyResponseError = errors.New("empty response")
 
 type CountryList []string
 
@@ -251,7 +250,13 @@ func zgettunnels(ctx context.Context,
 		reterr = err
 		return
 	}
-	reterr = json.Unmarshal(data, &tunnels)
+	err = json.Unmarshal(data, &tunnels)
+	if err != nil {
+		return nil, fmt.Errorf("unable to unmashal zgettunnels response: %w", err)
+	}
+	if len(tunnels.IPList) == 0 {
+		return nil, EmptyResponseError
+	}
 	res = &tunnels
 	return
 }
@@ -322,18 +327,42 @@ func Tunnels(ctx context.Context,
 	client *http.Client,
 	country string,
 	proxy_type string,
-	limit uint) (res *ZGetTunnelsResponse, user_uuid string, reterr error) {
+	limit uint,
+	timeout time.Duration,
+	backoffInitial time.Duration,
+	backoffDeadline time.Duration,
+) (res *ZGetTunnelsResponse, user_uuid string, reterr error) {
 	u := uuid.New()
 	user_uuid = hex.EncodeToString(u[:])
-	initres, err := background_init(ctx, client, user_uuid)
+	ctx1, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+	initres, err := background_init(ctx1, client, user_uuid)
 	if err != nil {
 		reterr = err
 		return
 	}
-	sleepDuration := time.Duration(RandRange(float64(MinTunnelsPause), float64(MaxTunnelsPause)))
-	logger.Info("Sleeping for %v...", sleepDuration)
-	time.Sleep(sleepDuration)
-	res, reterr = zgettunnels(ctx, client, user_uuid, initres.Key, country, proxy_type, limit)
+	var bo backoff.BackOff = &backoff.ExponentialBackOff{
+		InitialInterval:     backoffInitial,
+		RandomizationFactor: 0.5,
+		Multiplier:          1.5,
+		MaxInterval:         10 * time.Minute,
+		MaxElapsedTime:      backoffDeadline,
+		Stop:                backoff.Stop,
+		Clock:               backoff.SystemClock,
+	}
+	bo = backoff.WithContext(bo, ctx)
+	err = backoff.RetryNotify(func() error {
+		ctx1, cancel := context.WithTimeout(ctx, timeout)
+		defer cancel()
+		res, reterr = zgettunnels(ctx1, client, user_uuid, initres.Key, country, proxy_type, limit)
+		return reterr
+	}, bo, func(err error, dur time.Duration) {
+		logger.Info("zgettunnels error: %v; will retry after %v", err, dur.Truncate(time.Millisecond))
+	})
+	if err != nil {
+		logger.Error("All attempts failed: %v", err)
+		return nil, "", err
+	}
 	return
 }
 
@@ -376,19 +405,18 @@ func httpClientWithProxy(agent *FallbackAgent) *http.Client {
 	}
 }
 
-func EnsureTransaction(baseCtx context.Context, txnTimeout time.Duration, txn func(context.Context, *http.Client) bool) (bool, error) {
+func EnsureTransaction(ctx context.Context, getFBTimeout time.Duration, txn func(context.Context, *http.Client) bool) (bool, error) {
 	client := httpClientWithProxy(nil)
 	defer client.CloseIdleConnections()
 
-	ctx, cancel := context.WithTimeout(baseCtx, txnTimeout)
-	defer cancel()
-
 	if txn(ctx, client) {
 		return true, nil
 	}
 
 	// Fallback needed
-	fbc, err := GetFallbackProxies(baseCtx)
+	getFBCtx, cancel := context.WithTimeout(ctx, getFBTimeout)
+	defer cancel()
+	fbc, err := GetFallbackProxies(getFBCtx)
 	if err != nil {
 		return false, err
 	}
@@ -396,10 +424,6 @@ func EnsureTransaction(baseCtx context.Context, txnTimeout time.Duration, txn fu
 	for _, agent := range fbc.Agents {
 		client = httpClientWithProxy(&agent)
 		defer client.CloseIdleConnections()
-
-		ctx, cancel = context.WithTimeout(baseCtx, txnTimeout)
-		defer cancel()
-
 		if txn(ctx, client) {
 			return true, nil
 		}

main.go

@@ -54,6 +54,10 @@ type CLIArgs struct {
 	showVersion                             bool
 	proxy                                   string
 	caFile                                  string
+	minPause                                time.Duration
+	maxPause                                time.Duration
+	backoffInitial                          time.Duration
+	backoffDeadline                         time.Duration
 }
 
 func parse_args() CLIArgs {
@@ -66,8 +70,10 @@ func parse_args() CLIArgs {
 	flag.StringVar(&args.bind_address, "bind-address", "127.0.0.1:8080", "HTTP proxy listen address")
 	flag.IntVar(&args.verbosity, "verbosity", 20, "logging verbosity "+
 		"(10 - debug, 20 - info, 30 - warning, 40 - error, 50 - critical)")
-	flag.DurationVar(&args.timeout, "timeout", 35*time.Second, "timeout for network operations")
+	flag.DurationVar(&args.timeout, "timeout", 10*time.Second, "timeout for network operations")
 	flag.DurationVar(&args.rotate, "rotate", 1*time.Hour, "rotate user ID once per given period")
+	flag.DurationVar(&args.backoffInitial, "backoff-initial", 3*time.Second, "initial average backoff delay for zgettunnels (randomized by +/-50%)")
+	flag.DurationVar(&args.backoffDeadline, "backoff-deadline", 5*time.Minute, "total duration of zgettunnels method attempts")
 	flag.StringVar(&args.proxy_type, "proxy-type", "direct", "proxy type: direct or lum") // or skip but not mentioned
 	// skip would be used something like this: `./bin/hola-proxy -proxy-type skip -force-port-field 24232 -country ua.peer` for debugging
 	flag.StringVar(&args.resolver, "resolver", "https://cloudflare-dns.com/dns-query",
@@ -163,8 +169,10 @@ func run() int {
 	if args.list_countries {
 		return print_countries(args.timeout)
 	}
+
 	if args.list_proxies {
-		return print_proxies(mainLogger, args.country, args.proxy_type, args.limit, args.timeout)
+		return print_proxies(mainLogger, args.country, args.proxy_type, args.limit, args.timeout,
+			args.backoffInitial, args.backoffDeadline)
 	}
 
 	mainLogger.Info("hola-proxy client version %s is starting...", version)
@@ -176,7 +184,8 @@ func run() int {
 	}
 
 	mainLogger.Info("Initializing configuration provider...")
-	auth, tunnels, err := CredService(args.rotate, args.timeout, args.country, args.proxy_type, credLogger)
+	auth, tunnels, err := CredService(args.rotate, args.timeout, args.country, args.proxy_type, credLogger,
+		args.backoffInitial, args.backoffDeadline)
 	if err != nil {
 		mainLogger.Critical("Unable to instantiate credential service: %v", err)
 		return 4

snapcraft.yaml

@@ -1,5 +1,5 @@
 name: hola-proxy
-version: '1.5.9'
+version: '1.7.0'
 summary: Standalone Hola proxy client.
 description: |
   Standalone Hola proxy client. Just run it and it'll start plain HTTP proxy server forwarding traffic via Hola proxies of your choice.

utils.go

@@ -112,7 +112,9 @@ func print_countries(timeout time.Duration) int {
 		err       error
 	)
 	tx_res, tx_err := EnsureTransaction(context.Background(), timeout, func(ctx context.Context, client *http.Client) bool {
-		countries, err = VPNCountries(ctx, client)
+		ctx1, cancel := context.WithTimeout(ctx, timeout)
+		defer cancel()
+		countries, err = VPNCountries(ctx1, client)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Transaction error: %v. Retrying with the fallback mechanism...\n", err)
 			return false
@@ -133,14 +135,16 @@ func print_countries(timeout time.Duration) int {
 	return 0
 }
 
-func print_proxies(logger *CondLogger, country string, proxy_type string, limit uint, timeout time.Duration) int {
+func print_proxies(logger *CondLogger, country string, proxy_type string,
+	limit uint, timeout time.Duration, backoffInitial time.Duration, backoffDeadline time.Duration,
+) int {
 	var (
 		tunnels   *ZGetTunnelsResponse
 		user_uuid string
 		err       error
 	)
 	tx_res, tx_err := EnsureTransaction(context.Background(), timeout, func(ctx context.Context, client *http.Client) bool {
-		tunnels, user_uuid, err = Tunnels(ctx, logger, client, country, proxy_type, limit)
+		tunnels, user_uuid, err = Tunnels(ctx, logger, client, country, proxy_type, limit, timeout, backoffInitial, backoffDeadline)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Transaction error: %v. Retrying with the fallback mechanism...\n", err)
 			return false
@@ -294,10 +298,10 @@ func copyBody(wr io.Writer, body io.Reader) {
 	}
 }
 
-func RandRange(low, hi float64) float64 {
+func RandRange(low, hi int64) int64 {
 	if low >= hi {
 		panic("RandRange: low boundary is greater or equal to high boundary")
 	}
 	delta := hi - low
-	return low + rand.New(RandomSource).Float64()*delta
+	return low + rand.New(RandomSource).Int63n(delta+1)
 }