[PATCH 2/2 nft] jump: Allow goto and jump to a variable using nft input files

[Fernando Fernandez Mancera <ffmancera@riseup.net>]

This patch introduces the use of nft input files variables in 'jump' and 'goto'
statements, e.g.

define dest = ber

add table ip foo
add chain ip foo bar {type filter hook input priority 0;}
add chain ip foo ber
add rule ip foo ber counter
add rule ip foo bar jump $dest

table ip foo {
	chain bar {
		type filter hook input priority filter; policy accept;
		jump ber
	}

	chain ber {
		counter packets 71 bytes 6664
	}
}

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
---
 src/datatype.c     | 11 +++++++++++
 src/parser_bison.y |  6 +++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/datatype.c b/src/datatype.c
index 6aaf9ea..7e9ec5e 100644
--- a/src/datatype.c
+++ b/src/datatype.c
@@ -297,11 +297,22 @@ static void verdict_type_print(const struct expr *expr, struct output_ctx *octx)
 	}
 }
 
+static struct error_record *verdict_type_parse(const struct expr *sym,
+					       struct expr **res)
+{
+	*res = constant_expr_alloc(&sym->location, &string_type,
+				   BYTEORDER_HOST_ENDIAN,
+				   (strlen(sym->identifier) + 1) * BITS_PER_BYTE,
+				   sym->identifier);
+	return NULL;
+}
+
 const struct datatype verdict_type = {
 	.type		= TYPE_VERDICT,
 	.name		= "verdict",
 	.desc		= "netfilter verdict",
 	.print		= verdict_type_print,
+	.parse		= verdict_type_parse,
 };
 
 static const struct symbol_table nfproto_tbl = {
diff --git a/src/parser_bison.y b/src/parser_bison.y
index 69b5773..a955cb5 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -3841,7 +3841,11 @@ verdict_expr		:	ACCEPT
 			}
 			;
 
-chain_expr		:	identifier
+chain_expr		:	variable_expr
+			{
+				$$ = $1;
+			}
+			|	identifier
 			{
 				$$ = constant_expr_alloc(&@$, &string_type,
 							 BYTEORDER_HOST_ENDIAN,
-- 
2.20.1