--- /dev/null
+From 07af4429241c9832a613cb8620331ac54257d9df Mon Sep 17 00:00:00 2001
+From: Stijn Tintel <stijn@linux-ipv6.be>
+Date: Tue, 21 Dec 2021 12:40:25 +0200
+Subject: [PATCH] parser: allow quoted string in flowtable_expr_member
+
+Devices with interface names starting with a digit can not be configured
+in flowtables. Trying to do so throws the following error:
+
+Error: syntax error, unexpected number, expecting comma or '}'
+devices = { eth0, 6in4-wan6 };
+
+This is however a perfectly valid interface name. Solve the issue by
+allowing the use of quoted strings.
+
+Suggested-by: Jo-Philipp Wich <jo@mein.io>
+Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+ src/parser_bison.y | 9 ++++++++-
+ 1 file changed, 8 insertions(+), 1 deletion(-)
+
+diff --git a/src/parser_bison.y b/src/parser_bison.y
+index 16607bb7..1136ab91 100644
+--- a/src/parser_bison.y
++++ b/src/parser_bison.y
+@@ -2151,7 +2151,14 @@ flowtable_list_expr : flowtable_expr_member
+ | flowtable_list_expr COMMA opt_newline
+ ;
+
+-flowtable_expr_member : STRING
++flowtable_expr_member : QUOTED_STRING
++ {
++ $$ = constant_expr_alloc(&@$, &string_type,
++ BYTEORDER_HOST_ENDIAN,
++ strlen($1) * BITS_PER_BYTE, $1);
++ xfree($1);
++ }
++ | STRING
+ {
+ $$ = constant_expr_alloc(&@$, &string_type,
+ BYTEORDER_HOST_ENDIAN,
+--
+2.33.1
+