From 3937eddebc0f94b421cf87bbe903ddd091ab691d Mon Sep 17 00:00:00 2001
From: hwdsl2 <hwdsl2@users.noreply.github.com>
Date: Tue, 3 May 2022 22:27:15 -0500
Subject: [PATCH] Fix xl2tpd on Ubuntu 22.04

- Fix xl2tpd on Ubuntu 22.04 by installing a newer version.
  Before this fix, IPsec/L2TP mode may not work on Ubuntu 22.04
  with errors like "Can not find tunnel".
  Ref: https://bugs.launchpad.net/ubuntu/+source/xl2tpd/+bug/1951832
---
 vpnsetup_ubuntu.sh | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/vpnsetup_ubuntu.sh b/vpnsetup_ubuntu.sh
index 18f0148..8066c34 100755
--- a/vpnsetup_ubuntu.sh
+++ b/vpnsetup_ubuntu.sh
@@ -80,6 +80,7 @@ check_os() {
       exiterr "This script only supports Ubuntu and Debian."
       ;;
   esac
+  os_arch=$(uname -m | tr -dc 'A-Za-z0-9_-')
   os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
   if [ "$os_ver" = "8" ] || [ "$os_ver" = "jessiesid" ]; then
     exiterr "Debian 8 or Ubuntu < 16.04 is not supported."
@@ -535,6 +536,19 @@ apply_gcp_mtu_fix() {
   fi
 }
 
+apply_xl2tpd_fix() {
+  if [ "$os_type" = "ubuntu" ] && [ "$os_ver" = "bookwormsid" ] && [ "$os_arch" = "x86_64" ]; then
+    xl2tpd_url="https://mirrors.kernel.org/ubuntu/pool/universe/x/xl2tpd"
+    deb_file="xl2tpd_1.3.16-1ubuntu0.1_amd64.deb"
+    cd /opt/src || exit 1
+    if wget -t 3 -T 30 -q -O "$deb_file" "$xl2tpd_url/$deb_file"; then
+      bigecho "Applying fix for xl2tpd..."
+      apt-get -yqq install "./$deb_file" >/dev/null
+    fi
+    /bin/rm -f "$deb_file"
+  fi
+}
+
 enable_on_boot() {
   bigecho "Enabling services on boot..."
   IPT_PST=/etc/init.d/iptables-persistent
@@ -687,6 +701,7 @@ vpnsetup() {
   create_vpn_config
   update_sysctl
   update_iptables
+  apply_xl2tpd_fix
   apply_gcp_mtu_fix
   enable_on_boot
   start_services