parser_json: permit empty device list

Normal input parser allows flowtables without 'devices' token, which
makes the json export part elide 'dev' entirely, this then breaks on
re-import:

$ nft -j -f json.dump
/tmp/json_1:1:14-14: Error: Object item not found: dev

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/src/parser_json.c b/src/parser_json.c
index 2ab0196461e240f69f8ded9df607f3fbd39a05b4..4913260434f47841567a638ece0be7dfbabd508a 100644 (file)
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -3158,7 +3158,7 @@ static struct cmd *json_parse_cmd_add_flowtable(struct json_ctx *ctx,
        const char *family, *hook, *hookstr;
        struct flowtable *flowtable;
        struct handle h = { 0 };
-       json_t *devs;
+       json_t *devs = NULL;
        int prio;
 
        if (json_unpack_err(ctx, root, "{s:s, s:s}",
@@ -3187,14 +3187,15 @@ static struct cmd *json_parse_cmd_add_flowtable(struct json_ctx *ctx,
        if (op == CMD_DELETE || op == CMD_LIST)
                return cmd_alloc(op, cmd_obj, &h, int_loc, NULL);
 
-       if (json_unpack_err(ctx, root, "{s:s, s:I, s:o}",
+       if (json_unpack_err(ctx, root, "{s:s, s:I}",
                            "hook", &hook,
-                           "prio", &prio,
-                           "dev", &devs)) {
+                           "prio", &prio)) {
                handle_free(&h);
                return NULL;
        }
 
+       json_unpack(root, "{s:o}", &devs);
+
        hookstr = chain_hookname_lookup(hook);
        if (!hookstr) {
                json_error(ctx, "Invalid flowtable hook '%s'.", hook);
@@ -3209,12 +3210,14 @@ static struct cmd *json_parse_cmd_add_flowtable(struct json_ctx *ctx,
                                    BYTEORDER_HOST_ENDIAN,
                                    sizeof(int) * BITS_PER_BYTE, &prio);
 
-       flowtable->dev_expr = json_parse_flowtable_devs(ctx, devs);
-       if (!flowtable->dev_expr) {
-               json_error(ctx, "Invalid flowtable dev.");
-               flowtable_free(flowtable);
-               handle_free(&h);
-               return NULL;
+       if (devs) {
+               flowtable->dev_expr = json_parse_flowtable_devs(ctx, devs);
+               if (!flowtable->dev_expr) {
+                       json_error(ctx, "Invalid flowtable dev.");
+                       flowtable_free(flowtable);
+                       handle_free(&h);
+                       return NULL;
+               }
        }
        return cmd_alloc(op, cmd_obj, &h, int_loc, flowtable);
 }