From dc3c1a30cf7ce984986654ec78632f8de7db79c1 Mon Sep 17 00:00:00 2001
From: Matt Johnston <matt@ucc.asn.au>
Date: Wed, 9 Nov 2022 18:40:10 +0800
Subject: [PATCH] Allow overriding shells for compat getusershell()

---
 compat.c     | 3 +--
 sysoptions.h | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/compat.c b/compat.c
index 7a0e78a..8bd6add 100644
--- a/compat.c
+++ b/compat.c
@@ -231,8 +231,7 @@ void setusershell() {
 }
 
 static char **initshells() {
-	/* don't touch this list. */
-	static const char *okshells[] = { "/bin/sh", "/bin/csh", NULL };
+	static const char *okshells[] = { COMPAT_USER_SHELLS, NULL };
 	register char **sp, *cp;
 	register FILE *fp;
 	struct stat statb;
diff --git a/sysoptions.h b/sysoptions.h
index af931ff..24b902d 100644
--- a/sysoptions.h
+++ b/sysoptions.h
@@ -79,6 +79,15 @@
 
 #define _PATH_CP "/bin/cp"
 
+/* Default contents of /etc/shells if system getusershell() doesn't exist.
+ * Paths taken from getusershell(3) manpage. These can be customised
+ * on other platforms. One the commandline for CFLAGS it would look like eg
+  -DCOMPAT_USER_SHELLS='"/bin/sh","/apps/bin/sh","/data/bin/zsh"
+ */
+#ifndef COMPAT_USER_SHELLS
+#define COMPAT_USER_SHELLS "/bin/sh","/bin/csh"
+#endif
+
 #define DROPBEAR_ESCAPE_CHAR '~'
 
 /* success/failure defines */