tun2socks debug patch

patch.diff

diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index 78571d9..765b13f 100644
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -1,55 +1,28 @@
 #!/bin/sh

+# Modified version of
+# https://github.com/xjasonlyu/tun2socks/blob/main/docker/entrypoint.sh
+
 TUN="${TUN:-tun0}"
 ADDR="${ADDR:-198.18.0.1/15}"
 LOGLEVEL="${LOGLEVEL:-info}"

-# default values
-TABLE="${TABLE:-0x22b}"
-FWMARK="${FWMARK:-0x22b}"
-CLONE_MAIN="${CLONE_MAIN:-1}"
-
 create_tun() {
-  # create tun device
   ip tuntap add mode tun dev "$TUN"
   ip addr add "$ADDR" dev "$TUN"
   ip link set dev "$TUN" up
 }

-create_table() {
-  if [ "$CLONE_MAIN" -ne 0 ]; then
-    # clone main route table
-    ip route show table main |
-      while read -r route; do
-        ip route add ${route%linkdown*} table "$TABLE"
-      done
-    # replace default route
-    ip route replace default dev "$TUN" table "$TABLE"
-  else
-    # just add default route
-    ip route add default dev "$TUN" table "$TABLE"
-  fi
-}
-
 config_route() {
-  # policy routing
-  ip rule add not fwmark "$FWMARK" table "$TABLE"
-  ip rule add fwmark "$FWMARK" to "$ADDR" prohibit
-
-  # add tun included routes
   for addr in $(echo "$TUN_INCLUDED_ROUTES" | tr ',' '\n'); do
-    ip rule add to "$addr" table "$TABLE"
-  done
-
-  # add tun excluded routes
-  for addr in $(echo "$TUN_EXCLUDED_ROUTES" | tr ',' '\n'); do
-    ip rule add to "$addr" table main
+    ip route add $addr dev $TUN
   done
 }

+
 run() {
+
   create_tun
-  create_table
   config_route

   # execute extra commands
@@ -83,10 +56,9 @@ run() {

   exec tun2socks \
     --loglevel "$LOGLEVEL" \
-    --fwmark "$FWMARK" \
     --device "$TUN" \
     --proxy "$PROXY" \
     $ARGS
 }

-run || exit 1
+run || exit 1
\ No newline at end of file
diff --git a/proxy/socks5.go b/proxy/socks5.go
index d169994..f9329da 100644
--- a/proxy/socks5.go
+++ b/proxy/socks5.go
@@ -182,3 +182,31 @@ func (pc *socksPacketConn) Close() error {
 func serializeSocksAddr(m *M.Metadata) socks5.Addr {
        return socks5.SerializeAddr("", m.DstIP, m.DstPort)
 }
+
+func dumpByteSlice(b []byte) {
+       var a [16]byte
+       n := (len(b) + 15) &^ 15
+       for i := 0; i < n; i++ {
+               if i%16 == 0 {
+                       fmt.Printf("%4d", i)
+               }
+               if i%8 == 0 {
+                       fmt.Print(" ")
+               }
+               if i < len(b) {
+                       fmt.Printf(" %02X", b[i])
+               } else {
+                       fmt.Print("   ")
+               }
+               if i >= len(b) {
+                       a[i%16] = ' '
+               } else if b[i] < 32 || b[i] > 126 {
+                       a[i%16] = '.'
+               } else {
+                       a[i%16] = b[i]
+               }
+               if i%16 == 15 {
+                       fmt.Printf("  %s\n", string(a[:]))
+               }
+       }
+}
diff --git a/transport/socks5/socks5.go b/transport/socks5/socks5.go
index b2bf676..3201688 100644
--- a/transport/socks5/socks5.go
+++ b/transport/socks5/socks5.go
@@ -139,6 +139,7 @@ func (a Addr) UDPAddr() *net.UDPAddr {
        var port int
        switch a[0] {
        case AtypDomainName /* unsupported */ :
+               fmt.Printf("[transport|socks5] UDPAddr() has type AtypDomainName (unsupported) \n")
                return nil
        case AtypIPv4:
                ip = make([]byte, net.IPv4len)
@@ -179,6 +180,9 @@ func ClientHandshake(rw io.ReadWriter, addr Addr, command Command, user *User) (
                return nil, err
        }

+       //fmt.Printf("[transport|socks5] ClientHandshake() response buf\n")
+       //dumpByteSlice(buf[:MaxAddrLen])
+
        if buf[0] != Version {
                return nil, errors.New("socks version mismatched")
        }
@@ -230,6 +234,9 @@ func ClientHandshake(rw io.ReadWriter, addr Addr, command Command, user *User) (
                return nil, fmt.Errorf("%s: %s", command, rep)
        }

+       fmt.Printf("[transport|socks5] ClientHandshake() response buf\n")
+       dumpByteSlice(buf[:MaxAddrLen])
+
        return ReadAddr(rw, buf)
 }

@@ -381,6 +388,10 @@ func DecodeUDPPacket(packet []byte) (addr Addr, payload []byte, err error) {
        }

        payload = packet[3+len(addr):]
+
+       fmt.Printf("[transport|socks5] DecodeUDPPacket() buf\n")
+       dumpByteSlice(payload)
+
        return
 }

@@ -389,5 +400,37 @@ func EncodeUDPPacket(addr Addr, payload []byte) (packet []byte, err error) {
                return nil, errors.New("address is invalid")
        }
        packet = bytes.Join([][]byte{{0x00, 0x00, 0x00}, addr, payload}, nil)
+
+       fmt.Printf("[transport|socks5] EncodeUDPPacket() buf\n")
+       dumpByteSlice(payload)
+
        return
 }
+
+func dumpByteSlice(b []byte) {
+       var a [16]byte
+       n := (len(b) + 15) &^ 15
+       for i := 0; i < n; i++ {
+               if i%16 == 0 {
+                       fmt.Printf("%4d", i)
+               }
+               if i%8 == 0 {
+                       fmt.Print(" ")
+               }
+               if i < len(b) {
+                       fmt.Printf(" %02X", b[i])
+               } else {
+                       fmt.Print("   ")
+               }
+               if i >= len(b) {
+                       a[i%16] = ' '
+               } else if b[i] < 32 || b[i] > 126 {
+                       a[i%16] = '.'
+               } else {
+                       a[i%16] = b[i]
+               }
+               if i%16 == 15 {
+                       fmt.Printf("  %s\n", string(a[:]))
+               }
+       }
+}
diff --git a/tunnel/udp.go b/tunnel/udp.go
index 8b9c780..9f1aa6f 100644
--- a/tunnel/udp.go
+++ b/tunnel/udp.go
@@ -5,6 +5,7 @@ import (
        "net"
        "sync"
        "time"
+       "fmt"

        "github.com/xjasonlyu/tun2socks/v2/common/pool"
        "github.com/xjasonlyu/tun2socks/v2/core/adapter"
@@ -58,6 +59,7 @@ func handleUDPConn(uc adapter.UDPConn) {

        log.Infof("[UDP] %s <-> %s", metadata.SourceAddress(), metadata.DestinationAddress())
        relayPacket(uc, pc, remote)
+       log.Infof("[UDP] done relayPacket()")
 }

 func relayPacket(left net.PacketConn, right net.PacketConn, to net.Addr) {
@@ -66,6 +68,7 @@ func relayPacket(left net.PacketConn, right net.PacketConn, to net.Addr) {

        go func() {
                defer wg.Done()
+               log.Infof("[UDP] calling copyPacketBuffer(right, left, ...)")
                if err := copyPacketBuffer(right, left, to, _udpSessionTimeout); err != nil {
                        log.Warnf("[UDP] %v", err)
                }
@@ -73,6 +76,7 @@ func relayPacket(left net.PacketConn, right net.PacketConn, to net.Addr) {

        go func() {
                defer wg.Done()
+               log.Infof("[UDP] calling copyPacketBuffer(left, right, ...)")
                if err := copyPacketBuffer(left, right, nil, _udpSessionTimeout); err != nil {
                        log.Warnf("[UDP] %v", err)
                }
@@ -88,14 +92,20 @@ func copyPacketBuffer(dst net.PacketConn, src net.PacketConn, to net.Addr, timeo
        for {
                src.SetReadDeadline(time.Now().Add(timeout))
                n, _, err := src.ReadFrom(buf)
+               log.Infof("[UDP] src.ReadFrom(buf) read %d packets", n)
                if ne, ok := err.(net.Error); ok && ne.Timeout() {
+                       log.Infof("[UDP] ne.Timeout() reached")
                        return nil /* ignore I/O timeout */
                } else if err == io.EOF {
+                       log.Infof("[UDP] io.EOF reached")
                        return nil /* ignore EOF */
                } else if err != nil {
                        return err
                }

+               //log.Infof("[UDP] have buffer %#v", buf[:n])
+               dumpByteSlice(buf[:n])
+
                if _, err = dst.WriteTo(buf[:n], to); err != nil {
                        return err
                }
@@ -129,3 +139,31 @@ func (pc *symmetricNATPacketConn) ReadFrom(p []byte) (int, net.Addr, error) {
                return n, from, err
        }
 }
+
+func dumpByteSlice(b []byte) {
+       var a [16]byte
+       n := (len(b) + 15) &^ 15
+       for i := 0; i < n; i++ {
+               if i%16 == 0 {
+                       fmt.Printf("%4d", i)
+               }
+               if i%8 == 0 {
+                       fmt.Print(" ")
+               }
+               if i < len(b) {
+                       fmt.Printf(" %02X", b[i])
+               } else {
+                       fmt.Print("   ")
+               }
+               if i >= len(b) {
+                       a[i%16] = ' '
+               } else if b[i] < 32 || b[i] > 126 {
+                       a[i%16] = '.'
+               } else {
+                       a[i%16] = b[i]
+               }
+               if i%16 == 15 {
+                       fmt.Printf("  %s\n", string(a[:]))
+               }
+       }
+}