From 96e0c8c3906862c85f9f794299464410a7df2756 Mon Sep 17 00:00:00 2001
From: xjasonlyu <xjasonlyu@gmail.com>
Date: Wed, 10 Feb 2021 16:40:36 +0800
Subject: [PATCH] Chore: adapt fwmark option

---
 Dockerfile           |  6 ++---
 docker/entrypoint.sh | 56 +++++++++++++++++++-------------------------
 engine/engine.go     |  2 +-
 3 files changed, 27 insertions(+), 37 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 5187c8d..83d37fb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,10 +18,8 @@ RUN apk add --update --no-cache iptables iproute2 \
     && chmod +x /entrypoint.sh
 
 ENV TUN=tun0
-ENV ETH=eth0
-ENV TUN_ADDR=198.18.0.1
-ENV TUN_MASK=255.254.0.0
-ENV LOGLEVEL=INFO
+ENV TUN_ADDR=198.18.0.1/15
+ENV LOGLEVEL=info
 ENV PROXY=direct://
 ENV MTU=9000
 ENV STATS=
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index bd07176..8c0fae3 100644
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -1,47 +1,32 @@
 #!/bin/sh
 
 TUN="${TUN:-tun0}"
-ETH="${ETH:-eth0}"
-TUN_ADDR="${TUN_ADDR:-198.18.0.1}"
-TUN_MASK="${TUN_MASK:-255.254.0.0}"
-LOGLEVEL="${LOGLEVEL:-INFO}"
-
-mk_tun() {
-  # params
-  NAME="$1"
-  ADDR="$2"
-  MASK="$3"
+TUN_ADDR="${TUN_ADDR:-198.18.0.1/15}"
+LOGLEVEL="${LOGLEVEL:-info}"
+
+TABLE="${TABLE:-0x2d5}"
+FWMARK="${FWMARK:-0x2d5}"
+
+create_tun() {
   # create tun device
-  ip tuntap add mode tun dev "$NAME"
-  ip addr add "$ADDR/$MASK" dev "$NAME"
-  ip link set dev "$NAME" up
+  ip tuntap add mode tun dev "$TUN"
+  ip addr add "$TUN_ADDR" dev "$TUN"
+  ip link set dev "$TUN" up
 }
 
 config_route() {
-  # params
-  TABLE="$1"
-  TUN_IF="$2"
-  ETH_IF="$3"
-
-  # add custom table
-  printf "%s\t%s\n" 100 "$TABLE" >>/etc/iproute2/rt_tables
-
   # clone main route
   ip route show table main |
     while read -r route; do
       ip route add ${route%linkdown*} table "$TABLE"
     done
 
-  # config default route
-  ip route del default table "$TABLE"
-  ip route add default dev "$TUN_IF" table "$TABLE"
+  # replace default route
+  ip route replace default dev "$TUN" table "$TABLE"
 
   # policy routing
-  tun=$(ip -4 addr show "$TUN_IF" | awk 'NR==2 {print $2}')
-  eth=$(ip -4 addr show "$ETH_IF" | awk 'NR==2 {split($2,a,"/");print a[1]}')
-  ip rule add from "$eth" to "$tun" priority 9998 prohibit
-  ip rule add from "$eth" priority 9999 table main
-  ip rule add from all priority 10000 table "$TABLE"
+  ip rule add not fwmark "$FWMARK" table "$TABLE"
+  ip rule add fwmark "$FWMARK" to "$TUN_ADDR" prohibit
 
   # add tun included routes
   for addr in $(echo "$TUN_INCLUDED_ROUTES" | tr ',' '\n'); do
@@ -54,9 +39,16 @@ config_route() {
   done
 }
 
+disable_rp_filter() {
+  for path in /proc/sys/net/ipv4/conf/*; do
+    echo 0 > "$path/rp_filter"
+  done
+}
+
 main() {
-  mk_tun "$TUN" "$TUN_ADDR" "$TUN_MASK"
-  config_route "tun2socks" "$TUN" "$ETH"
+  create_tun
+  config_route
+  disable_rp_filter
 
   # execute extra commands
   if [ -n "$EXTRA_COMMANDS" ]; then
@@ -77,7 +69,7 @@ main() {
 
   exec tun2socks \
     --loglevel "$LOGLEVEL" \
-    --interface "$ETH" \
+    --fwmark "$FWMARK" \
     --device "$TUN" \
     --proxy "$PROXY" \
     $ARGS
diff --git a/engine/engine.go b/engine/engine.go
index 28a167d..d007968 100755
--- a/engine/engine.go
+++ b/engine/engine.go
@@ -98,7 +98,7 @@ func (e *engine) setLogLevel() error {
 func (e *engine) setMark() error {
 	if e.Mark != 0 {
 		dialer.SetMark(e.Mark)
-		log.Infof("[DIALER] set fwmark: %d", e.Mark)
+		log.Infof("[DIALER] set fwmark: %#x", e.Mark)
 	}
 	return nil
 }