Re: [Qemu-devel] [PATCH 12/13] QMP: Introduce qmp_check_input_obj()

[Markus Armbruster]

Luiz Capitulino <address@hidden> writes:

> This is similar to qmp_check_client_args(), but it checks if
> the input object follows the specification (QMP/qmp-spec.txt
> section 2.3).
>
> As we're limited to three keys, the work here is quite simple:
> we iterate over the input object, checking each time if the
> current argument complies to the specification.
>
> Signed-off-by: Luiz Capitulino <address@hidden>
> ---
>  monitor.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 45 insertions(+), 0 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 2a29095..a24a152 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -4163,6 +4163,46 @@ out:
>      return err;
>  }
>  
> +/*
> + * Input object checking rules
> + *
> + * 1. "execute" key must exist (not checked here)

Is it checked elsewhere?  If yes, make it (checked elsewhere already)

> + * 2. "execute" key must be a string
> + * 3. "arguments" key must be a dict
> + * 4. "id" key can be anything (ie. json-value)
> + * 5. Any argument not listed above is considered unexpected
> + */
> +static int qmp_check_input_obj(const QDict *input_obj)
> +{
> +    const QDictEntry *ent;
> +
> +    for (ent = qdict_first(input_obj); ent; ent = qdict_next(input_obj, 
> ent)) {
> +        const char *arg_name = qdict_entry_key(ent);
> +        const QObject *arg_obj = qdict_entry_value(ent);
> +
> +        if (!strcmp(arg_name, "execute")) {
> +            if (qobject_type(arg_obj) != QTYPE_QSTRING) {
> +                qerror_report(QERR_QMP_BAD_INPUT_OBJECT_MEMBER, "execute",
> +                              "string");
> +                return -1;
> +            }
> +        } else if (!strcmp(arg_name, "arguments")) {
> +            if (qobject_type(arg_obj) != QTYPE_QDICT) {
> +                qerror_report(QERR_QMP_BAD_INPUT_OBJECT_MEMBER, "arguments",
> +                              "object");
> +                return -1;
> +            }
> +        } else if (!strcmp(arg_name, "id")) {
> +            /* FIXME: check duplicated IDs for async commands */
> +        } else {
> +            qerror_report(QERR_QMP_UNEXPECTED_INPUT_OBJECT_MEMBER, arg_name);

Identifier's a bit on the long side, isn't it?

> +            return -1;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>  static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
>  {
>      int err;
> @@ -4187,6 +4227,11 @@ static void handle_qmp_command(JSONMessageParser 
> *parser, QList *tokens)
>  
>      input = qobject_to_qdict(obj);
>  
> +    err = qmp_check_input_obj(input);
> +    if (err < 0) {
> +        goto err_input;
> +    }
> +
>      mon->mc->id = qdict_get(input, "id");
>      qobject_incref(mon->mc->id);