From 9dd8fda4783e478b6f1c3ffe0be904902df48a96 Mon Sep 17 00:00:00 2001
From: "Andrew J. Hesford" <ajh@sideband.org>
Date: Sun, 23 Jan 2022 19:54:25 -0500
Subject: [PATCH] Allow dropbear.conf to customize listen address

---
 dropbear_hook | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/dropbear_hook b/dropbear_hook
index 6a9bae7..0de0425 100644
--- a/dropbear_hook
+++ b/dropbear_hook
@@ -6,7 +6,16 @@ run_hook ()
   mount -t devpts devpts /dev/pts
 
   echo "Starting dropbear"
-  /usr/sbin/dropbear -E -s -j -k
+
+  # Configuration processing and dropbear execution is done in a subshell
+  # to prevent dropbear.conf from inadvertently clobbering important variables
+  # or terminating the shell that is running /init.
+  (
+    # Load configuration options (currently only default listen address)
+    [ -r /etc/dropbear/dropbear.conf ] && . /etc/dropbear/dropbear.conf
+    /usr/sbin/dropbear -E -s -j -k -p "${dropbear_listen:-22}"
+  )
+
 }
 
 run_cleanuphook ()