src: json: refactor json parsing to allow tree based navigation

This patch refactors nft_*_json_parse to provide a new
intermediate function nft_jansson_parse_chain which will
allows us to navigate the entire json tree containing the
ruleset.

Signed-off-by: Álvaro Neira Ayuso <alvaroneay@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 81 insertions, 44 deletions

diff --git a/src/chain.c b/src/chain.c
index b196cd6..94e0c69 100644
--- a/src/chain.c
+++ b/src/chain.c
@@ -505,21 +505,16 @@ static inline int nft_str2hooknum(int family, const char *hook)
 	return -1;
 }
 
-static int nft_chain_json_parse(struct nft_chain *c, const char *json)
-{
 #ifdef JSON_PARSING
-	json_t *root, *node;
-	json_error_t error;
+static int nft_jansson_parse_chain(struct nft_chain *c, json_t *tree)
+{
+	json_t *root;
 	uint64_t uval64;
 	uint32_t policy;
 	int32_t val32;
 	const char *valstr;
 
-	node = nft_jansson_create_root(json, &error);
-	if (node == NULL)
-		return -1;
-
-	root = nft_jansson_get_node(node, "chain");
+	root = nft_jansson_get_node(tree, "chain");
 	if (root == NULL)
 		return -1;
 
@@ -591,12 +586,26 @@ static int nft_chain_json_parse(struct nft_chain *c, const char *json)
 		nft_chain_attr_set_u32(c, NFT_CHAIN_ATTR_POLICY, policy);
 	}
 
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return 0;
 
 err:
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return -1;
+}
+#endif
+
+static int nft_chain_json_parse(struct nft_chain *c, const char *json)
+{
+#ifdef JSON_PARSING
+	json_t *tree;
+	json_error_t error;
+
+	tree = nft_jansson_create_root(json, &error);
+	if (tree == NULL)
+		return -1;
+
+	return nft_jansson_parse_chain(c, tree);
 #else
 	errno = EOPNOTSUPP;
 	return -1;
diff --git a/src/rule.c b/src/rule.c
index a85005f..2f92e7d 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -475,22 +475,17 @@ int nft_rule_nlmsg_parse(const struct nlmsghdr *nlh, struct nft_rule *r)
 }
 EXPORT_SYMBOL(nft_rule_nlmsg_parse);
 
-static int nft_rule_json_parse(struct nft_rule *r, const char *json)
-{
 #ifdef JSON_PARSING
-	json_t *root, *node, *array;
-	json_error_t error;
+static int nft_jansson_parse_rule(struct nft_rule *r, json_t *tree)
+{
+	json_t *root, *array;
 	struct nft_rule_expr *e;
 	const char *str = NULL;
 	uint64_t uval64;
 	uint32_t uval32;
 	int i, family;
 
-	node = nft_jansson_create_root(json, &error);
-	if (node == NULL)
-		return -1;
-
-	root = nft_jansson_get_node(node, "rule");
+	root = nft_jansson_get_node(tree, "rule");
 	if (root == NULL)
 		return -1;
 
@@ -557,11 +552,25 @@ static int nft_rule_json_parse(struct nft_rule *r, const char *json)
 		nft_rule_add_expr(r, e);
 	}
 
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return 0;
 err:
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return -1;
+}
+#endif
+
+static int nft_rule_json_parse(struct nft_rule *r, const char *json)
+{
+#ifdef JSON_PARSING
+	json_t *tree;
+	json_error_t error;
+
+	tree = nft_jansson_create_root(json, &error);
+	if (tree == NULL)
+		return -1;
+
+	return nft_jansson_parse_rule(r, tree);
 #else
 	errno = EOPNOTSUPP;
 	return -1;
diff --git a/src/set.c b/src/set.c
index fe30e77..a4b644a 100644
--- a/src/set.c
+++ b/src/set.c
@@ -303,21 +303,16 @@ int nft_set_nlmsg_parse(const struct nlmsghdr *nlh, struct nft_set *s)
 }
 EXPORT_SYMBOL(nft_set_nlmsg_parse);
 
-static int nft_set_json_parse(struct nft_set *s, const char *json)
-{
 #ifdef JSON_PARSING
-	json_t *root, *node, *array, *json_elem;
-	json_error_t error;
+static int nft_jansson_parse_set(struct nft_set *s, json_t *tree)
+{
+	json_t *root, *array, *json_elem;
 	uint32_t uval32;
 	int family, i;
 	const char *valstr;
 	struct nft_set_elem *elem;
 
-	node = nft_jansson_create_root(json, &error);
-	if (node == NULL)
-		return -1;
-
-	root = nft_jansson_get_node(node, "set");
+	root = nft_jansson_get_node(tree, "set");
 	if (root == NULL)
 		return -1;
 
@@ -388,11 +383,26 @@ static int nft_set_json_parse(struct nft_set *s, const char *json)
 
 	}
 
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return 0;
 err:
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return -1;
+
+}
+#endif
+
+static int nft_set_json_parse(struct nft_set *s, const char *json)
+{
+#ifdef JSON_PARSING
+	json_t *tree;
+	json_error_t error;
+
+	tree = nft_jansson_create_root(json, &error);
+	if (tree == NULL)
+		return -1;
+
+	return nft_jansson_parse_set(s, tree);
 #else
 	errno = EOPNOTSUPP;
 	return -1;
diff --git a/src/table.c b/src/table.c
index 8d20be5..838c5ee 100644
--- a/src/table.c
+++ b/src/table.c
@@ -266,20 +266,15 @@ err:
 #endif
 }
 
-static int nft_table_json_parse(struct nft_table *t, const char *json)
-{
 #ifdef JSON_PARSING
-	json_t *root, *node;
-	json_error_t error;
+static int nft_jansson_parse_table(struct nft_table *t, json_t *tree)
+{
+	json_t *root;
 	uint32_t flags;
 	const char *str;
 	int family;
 
-	node = nft_jansson_create_root(json, &error);
-	if (node == NULL)
-		return -1;
-
-	root = nft_jansson_get_node(node, "table");
+	root = nft_jansson_get_node(tree, "table");
 	if (root == NULL)
 		return -1;
 
@@ -299,11 +294,25 @@ static int nft_table_json_parse(struct nft_table *t, const char *json)
 
 	nft_table_attr_set_u32(t, NFT_TABLE_ATTR_FLAGS, flags);
 
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return 0;
 err:
-	nft_jansson_free_root(node);
+	nft_jansson_free_root(tree);
 	return -1;
+}
+#endif
+
+static int nft_table_json_parse(struct nft_table *t, const char *json)
+{
+#ifdef JSON_PARSING
+	json_t *tree;
+	json_error_t error;
+
+	tree = nft_jansson_create_root(json, &error);
+	if (tree == NULL)
+		return -1;
+
+	return nft_jansson_parse_table(t, tree);
 #else
 	errno = EOPNOTSUPP;
 	return -1;