From e37641653ce2c5d12de2db4395078f21f880ee08 Mon Sep 17 00:00:00 2001
From: Hendrik Jonas Meyer <h.meyer@bigpoint.net>
Date: Tue, 16 Jan 2018 22:24:17 +0100
Subject: [PATCH] add option to drop the default route on providers, that do
 not override it properly

---
 README.md                               | 9 +++++++++
 transmission/environment-variables.tmpl | 3 +++
 transmission/start.sh                   | 5 +++++
 3 files changed, 17 insertions(+)

diff --git a/README.md b/README.md
index 1917b2fb2..f3c1390ba 100644
--- a/README.md
+++ b/README.md
@@ -367,3 +367,12 @@ $ sudo systemctl stop transmission-openvpn.service
 # Later ...
 $ sudo systemctl start transmission-openvpn.service
 ```
+
+## Drop the default route
+
+Some VPNs do not override the default route, but rather set other routes with a lower metric.  
+This might lead to te default route (your untunneled connection) to be used.
+
+To drop the default route set the environment variable `DROP_DEFAULT_ROUTE` to `true`.
+
+*Note*: This is not compatible with all VPNs. Please check yourself if your provider overrides the default route properly.
diff --git a/transmission/environment-variables.tmpl b/transmission/environment-variables.tmpl
index 5ae9d6538..db971dfd6 100644
--- a/transmission/environment-variables.tmpl
+++ b/transmission/environment-variables.tmpl
@@ -81,3 +81,6 @@ export PGID={{ .Env.PGID }}
 
 # Support custom web frontend
 {{ if .Env.TRANSMISSION_WEB_HOME }} export TRANSMISSION_WEB_HOME={{ .Env.TRANSMISSION_WEB_HOME }} {{end}}
+
+# Support dropping the default route after connection
+export DROP_DEFAULT_ROUTE={{ .Env.DROP_DEFAULT_ROUTE }}
diff --git a/transmission/start.sh b/transmission/start.sh
index 456a43faf..18665a978 100755
--- a/transmission/start.sh
+++ b/transmission/start.sh
@@ -38,6 +38,11 @@ fi
 
 . /etc/transmission/userSetup.sh
 
+if [ "true" = "$DROP_DEFAULT_ROUTE" ]; then
+  echo "DROPPING DEFAULT ROUTE"
+  ip r del default || exit 1
+fi
+
 echo "STARTING TRANSMISSION"
 exec sudo -E -u ${RUN_AS} /usr/bin/transmission-daemon -g ${TRANSMISSION_HOME} --logfile ${TRANSMISSION_HOME}/transmission.log &