SplitHTTP: More range options, change defaults, enforce maxUploadSize, fix querystring behavior (#3603)

* maxUploadSize and maxConcurrentUploads can now be ranges on the client
* maxUploadSize is now enforced on the server
* the default of maxUploadSize is 2MB on the server, and 1MB on the client
* the default of maxConcurrentUploads is 200 on the server, and 100 on the client
* ranges on the server are treated as a single number. if server is configured as `"1-2"`, server will enforce `2`
* querystrings in `path` are now handled correctly

Author: mmmray

infra/conf/transport_internet.go

@@ -229,8 +229,8 @@ type SplitHTTPConfig struct {
 	Host                 string            `json:"host"`
 	Path                 string            `json:"path"`
 	Headers              map[string]string `json:"headers"`
-	MaxConcurrentUploads int32             `json:"maxConcurrentUploads"`
-	MaxUploadSize        int32             `json:"maxUploadSize"`
+	MaxConcurrentUploads Int32Range        `json:"maxConcurrentUploads"`
+	MaxUploadSize        Int32Range        `json:"maxUploadSize"`
 	MinUploadIntervalMs  Int32Range        `json:"minUploadIntervalMs"`
 }
 
@@ -245,11 +245,17 @@ func (c *SplitHTTPConfig) Build() (proto.Message, error) {
 		c.Host = c.Headers["Host"]
 	}
 	config := &splithttp.Config{
-		Path:                 c.Path,
-		Host:                 c.Host,
-		Header:               c.Headers,
-		MaxConcurrentUploads: c.MaxConcurrentUploads,
-		MaxUploadSize:        c.MaxUploadSize,
+		Path:   c.Path,
+		Host:   c.Host,
+		Header: c.Headers,
+		MaxConcurrentUploads: &splithttp.RandRangeConfig{
+			From: c.MaxConcurrentUploads.From,
+			To:   c.MaxConcurrentUploads.To,
+		},
+		MaxUploadSize: &splithttp.RandRangeConfig{
+			From: c.MaxUploadSize.From,
+			To:   c.MaxUploadSize.To,
+		},
 		MinUploadIntervalMs: &splithttp.RandRangeConfig{
 			From: c.MinUploadIntervalMs.From,
 			To:   c.MinUploadIntervalMs.To,

transport/internet/splithttp/config.go

@@ -4,23 +4,28 @@ import (
 	"crypto/rand"
 	"math/big"
 	"net/http"
+	"strings"
 
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
-func (c *Config) GetNormalizedPath() string {
-	path := c.Path
-	if path == "" {
-		path = "/"
+func (c *Config) GetNormalizedPath(addPath string, addQuery bool) string {
+	pathAndQuery := strings.SplitN(c.Path, "?", 2)
+	path := pathAndQuery[0]
+	query := ""
+	if len(pathAndQuery) > 1 && addQuery {
+		query = "?" + pathAndQuery[1]
 	}
-	if path[0] != '/' {
+
+	if path == "" || path[0] != '/' {
 		path = "/" + path
 	}
 	if path[len(path)-1] != '/' {
 		path = path + "/"
 	}
-	return path
+
+	return path + addPath + query
 }
 
 func (c *Config) GetRequestHeader() http.Header {
@@ -31,33 +36,51 @@ func (c *Config) GetRequestHeader() http.Header {
 	return header
 }
 
-func (c *Config) GetNormalizedMaxConcurrentUploads() int32 {
-	if c.MaxConcurrentUploads == 0 {
-		return 10
+func (c *Config) GetNormalizedMaxConcurrentUploads(isServer bool) RandRangeConfig {
+	if c.MaxConcurrentUploads == nil {
+		if isServer {
+			return RandRangeConfig{
+				From: 200,
+				To:   200,
+			}
+		} else {
+			return RandRangeConfig{
+				From: 100,
+				To:   100,
+			}
+		}
 	}
 
-	return c.MaxConcurrentUploads
+	return *c.MaxConcurrentUploads
 }
 
-func (c *Config) GetNormalizedMaxUploadSize() int32 {
-	if c.MaxUploadSize == 0 {
-		return 1000000
+func (c *Config) GetNormalizedMaxUploadSize(isServer bool) RandRangeConfig {
+	if c.MaxUploadSize == nil {
+		if isServer {
+			return RandRangeConfig{
+				From: 2000000,
+				To:   2000000,
+			}
+		} else {
+			return RandRangeConfig{
+				From: 1000000,
+				To:   1000000,
+			}
+		}
 	}
 
-	return c.MaxUploadSize
+	return *c.MaxUploadSize
 }
 
 func (c *Config) GetNormalizedMinUploadInterval() RandRangeConfig {
-	r := c.MinUploadIntervalMs
-
-	if r == nil {
-		r = &RandRangeConfig{
+	if c.MinUploadIntervalMs == nil {
+		return RandRangeConfig{
 			From: 30,
 			To:   30,
 		}
 	}
 
-	return *r
+	return *c.MinUploadIntervalMs
 }
 
 func init() {

transport/internet/splithttp/config.pb.go

@@ -10,8 +10,8 @@ message Config {
   string host = 1;
   string path = 2;
   map<string, string> header = 3;
-  int32 maxConcurrentUploads = 4;
-  int32 maxUploadSize = 5;
+  RandRangeConfig maxConcurrentUploads = 4;
+  RandRangeConfig maxUploadSize = 5;
   RandRangeConfig minUploadIntervalMs = 6;
 }
 

transport/internet/splithttp/config.proto

@@ -0,0 +1,51 @@
+package splithttp_test
+
+import (
+	"testing"
+
+	. "github.com/xtls/xray-core/transport/internet/splithttp"
+)
+
+func Test_GetNormalizedPath(t *testing.T) {
+	c := Config{
+		Path: "/?world",
+	}
+
+	path := c.GetNormalizedPath("hello", true)
+	if path != "/hello?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath2(t *testing.T) {
+	c := Config{
+		Path: "?world",
+	}
+
+	path := c.GetNormalizedPath("hello", true)
+	if path != "/hello?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath3(t *testing.T) {
+	c := Config{
+		Path: "hello?world",
+	}
+
+	path := c.GetNormalizedPath("", true)
+	if path != "/hello/?world" {
+		t.Error("Unexpected: ", path)
+	}
+}
+
+func Test_GetNormalizedPath4(t *testing.T) {
+	c := Config{
+		Path: "hello?world",
+	}
+
+	path := c.GetNormalizedPath("", false)
+	if path != "/hello/" {
+		t.Error("Unexpected: ", path)
+	}
+}

transport/internet/splithttp/config_test.go

@@ -181,8 +181,8 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 	transportConfiguration := streamSettings.ProtocolSettings.(*Config)
 	tlsConfig := tls.ConfigFromStreamSettings(streamSettings)
 
-	maxConcurrentUploads := transportConfiguration.GetNormalizedMaxConcurrentUploads()
-	maxUploadSize := transportConfiguration.GetNormalizedMaxUploadSize()
+	maxConcurrentUploads := transportConfiguration.GetNormalizedMaxConcurrentUploads(false)
+	maxUploadSize := transportConfiguration.GetNormalizedMaxUploadSize(false)
 	minUploadInterval := transportConfiguration.GetNormalizedMinUploadInterval()
 
 	if tlsConfig != nil {
@@ -194,18 +194,17 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *internet.Me
 	if requestURL.Host == "" {
 		requestURL.Host = dest.NetAddr()
 	}
-	requestURL.Path = transportConfiguration.GetNormalizedPath()
-
-	httpClient := getHTTPClient(ctx, dest, streamSettings)
 
 	sessionIdUuid := uuid.New()
-	sessionId := sessionIdUuid.String()
-	baseURL := requestURL.String() + sessionId
+	requestURL.Path = transportConfiguration.GetNormalizedPath(sessionIdUuid.String(), true)
+	baseURL := requestURL.String()
+
+	httpClient := getHTTPClient(ctx, dest, streamSettings)
 
-	uploadPipeReader, uploadPipeWriter := pipe.New(pipe.WithSizeLimit(maxUploadSize))
+	uploadPipeReader, uploadPipeWriter := pipe.New(pipe.WithSizeLimit(maxUploadSize.roll()))
 
 	go func() {
-		requestsLimiter := semaphore.New(int(maxConcurrentUploads))
+		requestsLimiter := semaphore.New(int(maxConcurrentUploads.roll()))
 		var requestCounter int64
 
 		lastWrite := time.Now()