diff --git a/advLayer/grpcSimple/client.go b/advLayer/grpcSimple/client.go
index 2b5b209..ac27469 100644
--- a/advLayer/grpcSimple/client.go
+++ b/advLayer/grpcSimple/client.go
@@ -1,8 +1,5 @@
 package grpcSimple
 
-// Modified from: https://github.com/Dreamacro/clash/blob/master/transport/gun/gun.go
-// License: MIT
-
 import (
 	"bufio"
 	"crypto/tls"
@@ -174,8 +171,6 @@ func (c *Client) GetCommonConn(underlay net.Conn) (any, error) {
 
 }
 
-func (c *Client) ProcessWhenFull(underlay any) {}
-
 func (c *Client) DialSubConn(underlay any) (net.Conn, error) {
 
 	if underlay == nil {
diff --git a/advLayer/grpcSimple/common.go b/advLayer/grpcSimple/common.go
index 6e76321..31f86d6 100644
--- a/advLayer/grpcSimple/common.go
+++ b/advLayer/grpcSimple/common.go
@@ -11,6 +11,9 @@ import (
 	"github.com/e1732a364fed/v2ray_simple/utils"
 )
 
+// Modified from: https://github.com/Dreamacro/clash/blob/master/transport/gun/gun.go
+// License: MIT
+
 func commonWrite(b []byte) *bytes.Buffer {
 	protobufHeader := [binary.MaxVarintLen64 + 1]byte{0x0A}
 	varuintSize := binary.PutUvarint(protobufHeader[1:], uint64(len(b)))
@@ -58,7 +61,7 @@ func (c *commonPart) Read(b []byte) (n int, err error) {
 
 	protobufPayloadLen, err := binary.ReadUvarint(c.br)
 	if err != nil {
-		return 0, utils.ErrInErr{ErrDesc: "binary.ReadUvarint failed", ErrDetail: err, ExtraIs: []error{utils.ErrInvalidData}}
+		return 0, utils.ErrInErr{ErrDesc: "grpc Read, binary.ReadUvarint failed", ErrDetail: err, ExtraIs: []error{utils.ErrInvalidData}}
 	}
 
 	size := int(protobufPayloadLen)
diff --git a/advLayer/grpcSimple/server.go b/advLayer/grpcSimple/server.go
index 1b53268..18356b6 100644
--- a/advLayer/grpcSimple/server.go
+++ b/advLayer/grpcSimple/server.go
@@ -122,7 +122,7 @@ func (s *Server) StartHandle(underlay net.Conn, newSubConnChan chan net.Conn, fa
 
 					var buf *bytes.Buffer
 
-					sc := &netLayer.IOWrapper{
+					respConn := &netLayer.IOWrapper{
 						Reader:    rq.Body,
 						Writer:    rw,
 						CloseChan: make(chan struct{}),
@@ -130,7 +130,7 @@ func (s *Server) StartHandle(underlay net.Conn, newSubConnChan chan net.Conn, fa
 
 					fm := httpLayer.FallbackMeta{
 						Path: p,
-						Conn: sc,
+						Conn: respConn,
 					}
 
 					// 如果使用 rq.Write， 那么实际上就是回落到 http1.1, 只有用 http2.Transport.RoundTrip 才是 h2 请求
@@ -141,9 +141,9 @@ func (s *Server) StartHandle(underlay net.Conn, newSubConnChan chan net.Conn, fa
 						buf = utils.GetBuf()
 						rq.Write(buf)
 
-						sc.FirstWriteChan = make(chan struct{})
+						respConn.FirstWriteChan = make(chan struct{})
 
-						fm.FirstBuffer = buf
+						fm.H1RequestBuf = buf
 
 					} else {
 						fm.IsH2 = true
@@ -156,7 +156,7 @@ func (s *Server) StartHandle(underlay net.Conn, newSubConnChan chan net.Conn, fa
 
 					fallbackConnChan <- fm
 
-					<-sc.CloseChan
+					<-respConn.CloseChan
 
 				}
 
diff --git a/advLayer/ws/server.go b/advLayer/ws/server.go
index fd1bc7b..90da338 100644
--- a/advLayer/ws/server.go
+++ b/advLayer/ws/server.go
@@ -57,7 +57,7 @@ func (s *Server) Handshake(underlay net.Conn) (net.Conn, error) {
 
 	//我们目前只支持 ws on http1.1
 
-	var rp httpLayer.RequestParser
+	var rp httpLayer.H1RequestParser
 	re := rp.ReadAndParse(underlay)
 	if re != nil {
 		if re == httpLayer.ErrNotHTTP_Request {
@@ -77,10 +77,10 @@ func (s *Server) Handshake(underlay net.Conn) (net.Conn, error) {
 
 	if rp.Method != "GET" || s.Thepath != rp.Path {
 		return httpLayer.FallbackMeta{
-			Conn:        underlay,
-			FirstBuffer: optionalFirstBuffer,
-			Path:        rp.Path,
-			Method:      rp.Method,
+			Conn:         underlay,
+			H1RequestBuf: optionalFirstBuffer,
+			Path:         rp.Path,
+			Method:       rp.Method,
 		}, httpLayer.ErrShouldFallback
 	}
 
diff --git a/cmd/verysimple/main.go b/cmd/verysimple/main.go
index 6a8a69a..bd24c19 100644
--- a/cmd/verysimple/main.go
+++ b/cmd/verysimple/main.go
@@ -354,12 +354,19 @@ func mainFunc() (result int) {
 					}
 
 				}
+
+				//如果在非linux系统 上，仅设置了tproxy，则会遇到下面情况
+				if len(tproxyList) == 0 {
+					if !(defaultInServer != nil || len(allServers) > 0) {
+						configFileQualifiedToRun = false
+					}
+				}
 			}
 
 		}
 
 	}
-	//没配置可用的listen或者dial，而且还无法动态更改配置
+	//没可用的listen或者dial，而且还无法动态更改配置
 	if !configFileQualifiedToRun && !isFlexible() {
 		utils.Error("No valid proxy settings available, nor cli or apiServer feature enabled, exit now.")
 		return -1
diff --git a/examples/quic.server.toml b/examples/quic.server.toml
index 75ff915..ec8a761 100644
--- a/examples/quic.server.toml
+++ b/examples/quic.server.toml
@@ -5,7 +5,7 @@ host = "0.0.0.0"
 port = 4434
 version = 0
 insecure = true
-fallback = ":80"
+fallback = "udp://127.0.0.1:80"  #试图回落到 nginx的 无tls 的 udp的 http3 服务端口 (目前尚未支持quic的回落功能，请期待)
 cert = "cert.pem"
 key = "cert.key"
 advancedLayer = "quic"
diff --git a/examples/vlesss.server.toml b/examples/vlesss.server.toml
index 7a42373..667a327 100644
--- a/examples/vlesss.server.toml
+++ b/examples/vlesss.server.toml
@@ -7,7 +7,7 @@ host = "0.0.0.0"
 port = 4433
 version = 0
 insecure = true
-fallback = ":80"    # 默认回落地址.ip必须是本机ip(可以省略ip而只写端口,程序会默认补全127.0.0.1), 或者unix domain socket的文件名/路径, 或者 udp://127.0.0.1:80 这种url格式。 （用udp以试图回落到 nginx的 无tls 的 http3 服务端口）
+fallback = ":80"    # 默认回落地址.ip必须是本机ip(可以省略ip而只写端口,程序会默认补全127.0.0.1), 或者unix domain socket的文件名/路径, 或者 udp://127.0.0.1:80 这种url格式。 （用udp以试图回落到 nginx的 无tls 的 udp的 http3 服务端口，适用于 quic的情况）
 
 #cert = "cert.pem"   # 这里既可以默认放在程序本身目录下，也可以指定完整路径
 #key = "cert.key"    # 如果 cert和key中 有一项没给出, 或者文件不存在, 就会自动在内存中生成随机证书,
diff --git a/httpLayer/header.go b/httpLayer/header.go
index 57306a5..e9343ca 100644
--- a/httpLayer/header.go
+++ b/httpLayer/header.go
@@ -13,10 +13,13 @@ import (
 	"golang.org/x/exp/slices"
 )
 
-//观察v2ray的实现，在没有header时，还会添加一个 Date ，这个v2ray的文档里没提
-// https://www.v2fly.org/config/transport/tcp.html#noneheaderobject
-//
-// transport/internet/headers/http/http.go
+/*
+观察v2ray的实现，在没有header时，还会添加一个 Date ，这个v2ray的文档里没提
+
+v2ray文档: https://www.v2fly.org/config/transport/tcp.html#noneheaderobject
+
+相关 v2ray代码: transport/internet/headers/http/http.go
+*/
 
 type RequestHeader struct {
 	Version string              `toml:"version"` //默认值为 "1.1"
@@ -90,7 +93,7 @@ func (hh *HeaderPreset) AssignDefaultValue() {
 
 func (h *HeaderPreset) ReadRequest(underlay net.Conn) (err error, leftBuf *bytes.Buffer) {
 
-	var rp RequestParser
+	var rp H1RequestParser
 	err = rp.ReadAndParse(underlay)
 	if err != nil {
 		return
diff --git a/httpLayer/httpLayer.go b/httpLayer/httpLayer.go
index 885ee3b..66e3ca5 100644
--- a/httpLayer/httpLayer.go
+++ b/httpLayer/httpLayer.go
@@ -16,6 +16,7 @@ import (
 	"errors"
 	"io"
 	"net"
+	"strings"
 
 	"github.com/e1732a364fed/v2ray_simple/utils"
 
@@ -72,13 +73,34 @@ type RequestErr struct {
 	Method string
 }
 
-func (pe *RequestErr) Error() string {
-	return "InvaidRequest " + pe.Method + "," + pe.Path
+func (e *RequestErr) Is(err error) bool {
+	if err == nil {
+		return false
+	}
+	if re, ok := err.(*RequestErr); ok && re != nil {
+		return (e.Path == re.Path && e.Method == re.Path)
+	}
+	if err == utils.ErrInvalidData {
+		return true
+	}
+	return false
 }
 
-// RequestParser被用于 预读一个链接，判断该连接是否是有效的http请求,
+func (pe *RequestErr) Error() string {
+	var sb strings.Builder
+	sb.WriteString("InvaidRequest ")
+	sb.WriteString(pe.Method)
+	sb.WriteString(",")
+	sb.WriteString(pe.Path)
+
+	return sb.String()
+}
+
+// H1RequestParser被用于 预读一个链接，判断该连接是否是有效的http请求,
 // 并将Version，Path，Method 记录在结构中.
-type RequestParser struct {
+//
+// 只能过滤 http 0.9, 1.0 和 1.1. 无法过滤h2和h3.
+type H1RequestParser struct {
 	Version         string
 	Path            string
 	Method          string
@@ -88,7 +110,7 @@ type RequestParser struct {
 
 // 尝试读取数据并解析HTTP请求, 解析道道 数据会存入 RequestParser 结构中.
 //如果读取错误,会返回该错误; 如果读到的不是HTTP请求，返回 ErrNotHTTP_Request;
-func (rhr *RequestParser) ReadAndParse(r io.Reader) error {
+func (rhr *H1RequestParser) ReadAndParse(r io.Reader) error {
 	bs := utils.GetPacket()
 
 	n, e := r.Read(bs)
@@ -109,10 +131,10 @@ func (rhr *RequestParser) ReadAndParse(r io.Reader) error {
 // http level fallback metadata
 type FallbackMeta struct {
 	net.Conn
-	FirstBuffer *bytes.Buffer
-	Path        string
-	Method      string
-	IsH2        bool
+	H1RequestBuf *bytes.Buffer
+	Path         string
+	Method       string
+	IsH2         bool
 
 	H2Request *http.Request
 }
diff --git a/main.go b/main.go
index dc105a6..bb290ce 100644
--- a/main.go
+++ b/main.go
@@ -346,7 +346,7 @@ func handleNewIncomeConnection(inServer proxy.Server, defaultClientForThis proxy
 					newiics := iics
 
 					newiics.theRequestPath = fallbackMeta.Path
-					newiics.theFallbackFirstBuffer = fallbackMeta.FirstBuffer
+					newiics.theFallbackFirstBuffer = fallbackMeta.H1RequestBuf
 					newiics.wrappedConn = fallbackMeta.Conn
 					newiics.isFallbackH2 = fallbackMeta.IsH2
 					newiics.fallbackH2Request = fallbackMeta.H2Request
@@ -383,7 +383,7 @@ func handleNewIncomeConnection(inServer proxy.Server, defaultClientForThis proxy
 				meta := wsConn.(httpLayer.FallbackMeta)
 
 				iics.theRequestPath = meta.Path
-				iics.theFallbackFirstBuffer = meta.FirstBuffer
+				iics.theFallbackFirstBuffer = meta.H1RequestBuf
 				iics.wrappedConn = meta.Conn
 
 				if ce := utils.CanLogDebug("Single AdvLayer Check failed, will fallback."); ce != nil {
diff --git a/utils/io.go b/utils/io.go
index 1dd876c..1318306 100644
--- a/utils/io.go
+++ b/utils/io.go
@@ -17,6 +17,7 @@ type ByteWriter interface {
 	Write(p []byte) (n int, err error)
 }
 
+//optionally read from OptionalReader
 type ReadWrapper struct {
 	io.Reader
 	OptionalReader    io.Reader
@@ -47,6 +48,7 @@ type DummyReadCloser struct {
 	ReadCount int
 }
 
+// ReadCount -= 1 at each call.
 //if ReadCount<0, return 0, io.EOF
 func (d *DummyReadCloser) Read(p []byte) (int, error) {
 	d.ReadCount -= 1
@@ -68,6 +70,7 @@ type DummyWriteCloser struct {
 	WriteCount int
 }
 
+// WriteCount -= 1 at each call.
 //if WriteCount<0, return 0, io.EOF
 func (d *DummyWriteCloser) Write(p []byte) (int, error) {
 	d.WriteCount -= 1
@@ -86,10 +89,12 @@ func (DummyWriteCloser) Close() error {
 	return nil
 }
 
+//先从Old读，若SwitchChan被关闭, 立刻改为从New读
 type ReadSwitcher struct {
-	Old, New io.Reader
+	Old, New   io.Reader     //non-nil
+	SwitchChan chan struct{} //non-nil
+
 	io.Closer
-	SwitchChan chan struct{}
 
 	readOnce sync.Once
 
@@ -129,7 +134,6 @@ func (d *ReadSwitcher) Read(p []byte) (int, error) {
 	}
 }
 
-//return nil
 func (d *ReadSwitcher) Close() error {
 	if d.Closer != nil {
 		return d.Closer.Close()
@@ -137,10 +141,11 @@ func (d *ReadSwitcher) Close() error {
 	return nil
 }
 
+//先向Old写，若SwitchChan被关闭, 改为向New写
 type WriteSwitcher struct {
-	Old, New io.Writer
+	Old, New   io.Writer     //non-nil
+	SwitchChan chan struct{} //non-nil
 	io.Closer
-	SwitchChan chan struct{}
 }
 
 func (d *WriteSwitcher) Write(p []byte) (int, error) {
@@ -154,7 +159,6 @@ func (d *WriteSwitcher) Write(p []byte) (int, error) {
 	}
 }
 
-//return nil
 func (d *WriteSwitcher) Close() error {
 	if d.Closer != nil {
 		return d.Closer.Close()