path: root/include/json.h
diff options
authorPhil Sutter <>2018-10-26 15:01:38 +0200
committerPablo Neira Ayuso <>2018-10-29 11:15:08 +0100
commitbb32d8db9a125d9676f87866e48ffbf0221ec16a (patch)
treebfbeaf0ffb248aad38fab54b7630e2fe67e64ca7 /include/json.h
parent21d678639b28b99c301262c163128fdf67397ca6 (diff)
JSON: Add support for echo option
The basic principle is to not return a JSON object freshly created from netlink responses, but just update the existing user-provided one to make sure callers get back exactly what they expect. To achieve that, keep the parsed JSON object around in a global variable ('cur_root') and provide a custom callback to insert handles into it from received netlink messages. The tricky bit here is updating rules since unique identification is problematic. Therefore drop possibly present handles from input and later assume updates are received in order so the first rule not having a handle set is the right one. Signed-off-by: Phil Sutter <> Signed-off-by: Pablo Neira Ayuso <>
Diffstat (limited to 'include/json.h')
1 files changed, 15 insertions, 0 deletions
diff --git a/include/json.h b/include/json.h
index d2dc92d9..8d45c3c3 100644
--- a/include/json.h
+++ b/include/json.h
@@ -7,6 +7,7 @@ struct chain;
struct cmd;
struct expr;
struct netlink_ctx;
+struct nlmsghdr;
struct rule;
struct set;
struct obj;
@@ -103,6 +104,10 @@ void monitor_print_obj_json(struct netlink_mon_handler *monh,
void monitor_print_rule_json(struct netlink_mon_handler *monh,
const char *cmd, struct rule *r);
+int json_events_cb(const struct nlmsghdr *nlh,
+ struct netlink_mon_handler *monh);
+void json_print_echo(struct nft_ctx *ctx);
#else /* ! HAVE_LIBJANSSON */
typedef void json_t;
@@ -234,6 +239,16 @@ static inline void monitor_print_rule_json(struct netlink_mon_handler *monh,
/* empty */
+static inline int json_events_cb(const struct nlmsghdr *nlh)
+ return -1;
+static inline void json_print_echo(struct nft_ctx *ctx)
+ /* empty */
#endif /* HAVE_LIBJANSSON */
#endif /* NFTABLES_JSON_H */