src: allow variables in the chain priority specification

This patch allows you to use variables in chain priority definitions,
e.g.

define prio = filter
define prionum = 10
define prioffset = "filter - 150"

add table ip foo
add chain ip foo bar { type filter hook input priority $prio; }
add chain ip foo ber { type filter hook input priority $prionum; }
add chain ip foo bor { type filter hook input priority $prioffset; }

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/json.c b/src/json.c
index 9dfa3076..fd184183 100644
--- a/src/json.c
+++ b/src/json.c
@@ -223,6 +223,7 @@ static json_t *rule_print_json(struct output_ctx *octx,
 static json_t *chain_print_json(const struct chain *chain)
 {
 	json_t *root, *tmp;
+	int priority;
 
 	root = json_pack("{s:s, s:s, s:s, s:I}",
 			 "family", family2str(chain->handle.family),
@@ -231,11 +232,13 @@ static json_t *chain_print_json(const struct chain *chain)
 			 "handle", chain->handle.handle.id);
 
 	if (chain->flags & CHAIN_F_BASECHAIN) {
+		mpz_export_data(&priority, chain->priority.expr->value,
+				BYTEORDER_HOST_ENDIAN, sizeof(int));
 		tmp = json_pack("{s:s, s:s, s:i, s:s}",
 				"type", chain->type,
 				"hook", hooknum2str(chain->handle.family,
 						    chain->hooknum),
-				"prio", chain->priority.num,
+				"prio", priority,
 				"policy", chain_policy2str(chain->policy));
 		if (chain->dev)
 			json_object_set_new(tmp, "dev", json_string(chain->dev));
@@ -373,14 +376,16 @@ static json_t *obj_print_json(const struct obj *obj)
 static json_t *flowtable_print_json(const struct flowtable *ftable)
 {
 	json_t *root, *devs = NULL;
-	int i;
+	int i, priority;
 
+	mpz_export_data(&priority, ftable->priority.expr->value,
+			BYTEORDER_HOST_ENDIAN, sizeof(int));
 	root = json_pack("{s:s, s:s, s:s, s:s, s:i}",
 			"family", family2str(ftable->handle.family),
 			"name", ftable->handle.flowtable,
 			"table", ftable->handle.table.name,
 			"hook", hooknum2str(NFPROTO_NETDEV, ftable->hooknum),
-			"prio", ftable->priority.num);
+			"prio", priority);
 
 	for (i = 0; i < ftable->dev_array_len; i++) {
 		const char *dev = ftable->dev_array[i];