json: Enforce correctly formatted JSON config files

json-c's json_object_from_fd() doesn't set the JSON_TOKENER_STRICT
flag. This means the parser is more failure tolerant. Let's be strict
and enforce fully correctly formatted configuration.

Signed-off-by: Daniel Wagner <dwagner@suse.de>

diff --git a/src/nvme/json.c b/src/nvme/json.c
index 36dab6a45847e96370140228815df7c77f34ebaf..38ac1be2305ff8241dde0a793e7fa2ade341f2d5 100644 (file)
--- a/src/nvme/json.c
+++ b/src/nvme/json.c
@@ -158,6 +158,43 @@ static void json_parse_host(nvme_root_t r, struct json_object *host_obj)
        }
 }
 
+static struct json_object *parse_json(nvme_root_t r, int fd)
+{
+       char buf[JSON_FILE_BUF_SIZE];
+       struct json_object *obj = NULL;
+       struct printbuf *pb;
+       json_tokener *tok = NULL;
+       int ret;
+
+       pb = printbuf_new();
+       if (!pb)
+               return NULL;
+
+       while ((ret = read(fd, buf, JSON_FILE_BUF_SIZE)) > 0)
+               printbuf_memappend(pb, buf, ret);
+
+       if (ret < 0)
+               goto out;
+
+       tok = json_tokener_new_ex(JSON_TOKENER_DEFAULT_DEPTH);
+       if (!tok)
+               goto out;
+
+       /* Enforce correctly formatted JSON */
+       tok->flags = JSON_TOKENER_STRICT;
+
+       obj = json_tokener_parse_ex(tok, pb->buf, printbuf_length(pb));
+       if (!obj)
+               nvme_msg(r, LOG_DEBUG, "JSON parsing failed: %s\n",
+                        json_util_get_last_err());
+out:
+       if (tok)
+               json_tokener_free(tok);
+       printbuf_free(pb);
+
+       return obj;
+}
+
 int json_read_config(nvme_root_t r, const char *config_file)
 {
        struct json_object *json_root, *host_obj;
@@ -169,10 +206,8 @@ int json_read_config(nvme_root_t r, const char *config_file)
                         config_file, strerror(errno));
                return fd;
        }
-       json_root = json_object_from_fd(fd);
+       json_root = parse_json(r, fd);
        if (!json_root) {
-               nvme_msg(r, LOG_DEBUG, "Failed to read %s, %s\n",
-                       config_file, json_util_get_last_err());
                errno = EPROTO;
                close(fd);
                return -1;