json_parser_parse_err() may return something else than a QDict, in
which case we loose the object. Let's keep track of the original
object to avoid leaks.
When an error occurs, "qdict" contains the response, but we still
check the "execute" key there. Untangle a bit this code, by having a
clear error path.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
qga/main.c | 50 +++++++++++++++++++++++++-------------------------
1 file changed, 25 insertions(+), 25 deletions(-)
diff --git a/qga/main.c b/qga/main.c
index 537cc0e162..0784761605 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -600,6 +600,7 @@ static void process_command(GAState *s, QDict *req)
static void process_event(JSONMessageParser *parser, GQueue *tokens)
{
GAState *s = container_of(parser, GAState, parser);
+ QObject *obj;
QDict *qdict;
Error *err = NULL;
int ret;
@@ -607,35 +608,34 @@ static void process_event(JSONMessageParser *parser, GQueue *tokens)
g_assert(s && parser);
g_debug("process_event: called");
- qdict = qobject_to(QDict, json_parser_parse_err(tokens, NULL, &err));
- if (err || !qdict) {
- qobject_unref(qdict);
- if (!err) {
- g_warning("failed to parse event: unknown error");
- error_setg(&err, QERR_JSON_PARSING);
- } else {
- g_warning("failed to parse event: %s", error_get_pretty(err));
- }
- qdict = qmp_error_response(err);
+ obj = json_parser_parse_err(tokens, NULL, &err);
+ if (err) {
+ goto err;
}
-
- /* handle host->guest commands */
- if (qdict_haskey(qdict, "execute")) {
- process_command(s, qdict);
- } else {
- if (!qdict_haskey(qdict, "error")) {
- qobject_unref(qdict);
- g_warning("unrecognized payload format");
- error_setg(&err, QERR_UNSUPPORTED);
- qdict = qmp_error_response(err);
- }
- ret = send_response(s, qdict);
- if (ret < 0) {
- g_warning("error sending error response: %s", strerror(-ret));
- }
+ qdict = qobject_to(QDict, obj);
+ if (!qdict) {
+ error_setg(&err, QERR_JSON_PARSING);
+ goto err;
+ }
+ if (!qdict_haskey(qdict, "execute")) {
+ g_warning("unrecognized payload format");
+ error_setg(&err, QERR_UNSUPPORTED);
+ goto err;
}
+ process_command(s, qdict);
+ qobject_unref(obj);
+ return;
+
+err:
+ g_warning("failed to parse event: %s", error_get_pretty(err));
+ qdict = qmp_error_response(err);
+ ret = send_response(s, qdict);
+ if (ret < 0) {
+ g_warning("error sending error response: %s", strerror(-ret));
+ }
qobject_unref(qdict);
+ qobject_unref(obj);
}
/* false return signals GAChannel to close the current client connection */
--
2.18.0.rc1
Marc-André Lureau <marcandre.lureau@redhat.com> writes:
> json_parser_parse_err() may return something else than a QDict, in
> which case we loose the object. Let's keep track of the original
> object to avoid leaks.
Should this leak fix go into 3.0?
> When an error occurs, "qdict" contains the response, but we still
> check the "execute" key there.
Harmless.
> Untangle a bit this code, by having a
> clear error path.
Untangling might make sense anyway. Let's see.
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> qga/main.c | 50 +++++++++++++++++++++++++-------------------------
> 1 file changed, 25 insertions(+), 25 deletions(-)
>
> diff --git a/qga/main.c b/qga/main.c
> index 537cc0e162..0784761605 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -600,6 +600,7 @@ static void process_command(GAState *s, QDict *req)
> static void process_event(JSONMessageParser *parser, GQueue *tokens)
> {
> GAState *s = container_of(parser, GAState, parser);
> + QObject *obj;
> QDict *qdict;
> Error *err = NULL;
> int ret;
> @@ -607,35 +608,34 @@ static void process_event(JSONMessageParser *parser, GQueue *tokens)
> g_assert(s && parser);
>
> g_debug("process_event: called");
> - qdict = qobject_to(QDict, json_parser_parse_err(tokens, NULL, &err));
> - if (err || !qdict) {
> - qobject_unref(qdict);
> - if (!err) {
> - g_warning("failed to parse event: unknown error");
> - error_setg(&err, QERR_JSON_PARSING);
> - } else {
> - g_warning("failed to parse event: %s", error_get_pretty(err));
> - }
> - qdict = qmp_error_response(err);
> + obj = json_parser_parse_err(tokens, NULL, &err);
> + if (err) {
> + goto err;
> }
> -
> - /* handle host->guest commands */
> - if (qdict_haskey(qdict, "execute")) {
> - process_command(s, qdict);
> - } else {
> - if (!qdict_haskey(qdict, "error")) {
> - qobject_unref(qdict);
> - g_warning("unrecognized payload format");
> - error_setg(&err, QERR_UNSUPPORTED);
> - qdict = qmp_error_response(err);
> - }
> - ret = send_response(s, qdict);
> - if (ret < 0) {
> - g_warning("error sending error response: %s", strerror(-ret));
> - }
> + qdict = qobject_to(QDict, obj);
> + if (!qdict) {
> + error_setg(&err, QERR_JSON_PARSING);
> + goto err;
> + }
> + if (!qdict_haskey(qdict, "execute")) {
> + g_warning("unrecognized payload format");
> + error_setg(&err, QERR_UNSUPPORTED);
> + goto err;
> }
>
> + process_command(s, qdict);
> + qobject_unref(obj);
> + return;
> +
> +err:
> + g_warning("failed to parse event: %s", error_get_pretty(err));
> + qdict = qmp_error_response(err);
> + ret = send_response(s, qdict);
> + if (ret < 0) {
> + g_warning("error sending error response: %s", strerror(-ret));
> + }
> qobject_unref(qdict);
> + qobject_unref(obj);
> }
>
> /* false return signals GAChannel to close the current client connection */
Control flow is much improved. Took me a minute to convince myself the
reference counting is okay: qdict is a weak reference before qdict =
qmp_error_response(), and becomes strong there. Suggest to use a new
variable @err_rsp for the latter purpose.
Regardless:
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Hi
On Tue, Jul 17, 2018 at 7:53 AM, Markus Armbruster <armbru@redhat.com> wrote:
> Marc-André Lureau <marcandre.lureau@redhat.com> writes:
>
>> json_parser_parse_err() may return something else than a QDict, in
>> which case we loose the object. Let's keep track of the original
>> object to avoid leaks.
>
> Should this leak fix go into 3.0?
It has been there for a while, but it could be fixed for 3.0 indeed.
>
>> When an error occurs, "qdict" contains the response, but we still
>> check the "execute" key there.
>
> Harmless.
>
>> Untangle a bit this code, by having a
>> clear error path.
>
> Untangling might make sense anyway. Let's see.
>
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>> qga/main.c | 50 +++++++++++++++++++++++++-------------------------
>> 1 file changed, 25 insertions(+), 25 deletions(-)
>>
>> diff --git a/qga/main.c b/qga/main.c
>> index 537cc0e162..0784761605 100644
>> --- a/qga/main.c
>> +++ b/qga/main.c
>> @@ -600,6 +600,7 @@ static void process_command(GAState *s, QDict *req)
>> static void process_event(JSONMessageParser *parser, GQueue *tokens)
>> {
>> GAState *s = container_of(parser, GAState, parser);
>> + QObject *obj;
>> QDict *qdict;
>> Error *err = NULL;
>> int ret;
>> @@ -607,35 +608,34 @@ static void process_event(JSONMessageParser *parser, GQueue *tokens)
>> g_assert(s && parser);
>>
>> g_debug("process_event: called");
>> - qdict = qobject_to(QDict, json_parser_parse_err(tokens, NULL, &err));
>> - if (err || !qdict) {
>> - qobject_unref(qdict);
>> - if (!err) {
>> - g_warning("failed to parse event: unknown error");
>> - error_setg(&err, QERR_JSON_PARSING);
>> - } else {
>> - g_warning("failed to parse event: %s", error_get_pretty(err));
>> - }
>> - qdict = qmp_error_response(err);
>> + obj = json_parser_parse_err(tokens, NULL, &err);
>> + if (err) {
>> + goto err;
>> }
>> -
>> - /* handle host->guest commands */
>> - if (qdict_haskey(qdict, "execute")) {
>> - process_command(s, qdict);
>> - } else {
>> - if (!qdict_haskey(qdict, "error")) {
>> - qobject_unref(qdict);
>> - g_warning("unrecognized payload format");
>> - error_setg(&err, QERR_UNSUPPORTED);
>> - qdict = qmp_error_response(err);
>> - }
>> - ret = send_response(s, qdict);
>> - if (ret < 0) {
>> - g_warning("error sending error response: %s", strerror(-ret));
>> - }
>> + qdict = qobject_to(QDict, obj);
>> + if (!qdict) {
>> + error_setg(&err, QERR_JSON_PARSING);
>> + goto err;
>> + }
>> + if (!qdict_haskey(qdict, "execute")) {
>> + g_warning("unrecognized payload format");
>> + error_setg(&err, QERR_UNSUPPORTED);
>> + goto err;
>> }
>>
>> + process_command(s, qdict);
>> + qobject_unref(obj);
>> + return;
>> +
>> +err:
>> + g_warning("failed to parse event: %s", error_get_pretty(err));
>> + qdict = qmp_error_response(err);
>> + ret = send_response(s, qdict);
>> + if (ret < 0) {
>> + g_warning("error sending error response: %s", strerror(-ret));
>> + }
>> qobject_unref(qdict);
>> + qobject_unref(obj);
>> }
>>
>> /* false return signals GAChannel to close the current client connection */
>
> Control flow is much improved. Took me a minute to convince myself the
> reference counting is okay: qdict is a weak reference before qdict =
> qmp_error_response(), and becomes strong there. Suggest to use a new
> variable @err_rsp for the latter purpose.
Yes, the code is further improved in patch 11.
>
> Regardless:
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
>
thanks
--
Marc-André Lureau
Mike, I got a bug fix for you to consider for 3.0.
Marc-André, there's one remark for you inline.
Marc-André Lureau <marcandre.lureau@gmail.com> writes:
> Hi
>
> On Tue, Jul 17, 2018 at 7:53 AM, Markus Armbruster <armbru@redhat.com> wrote:
>> Marc-André Lureau <marcandre.lureau@redhat.com> writes:
>>
>>> json_parser_parse_err() may return something else than a QDict, in
>>> which case we loose the object. Let's keep track of the original
>>> object to avoid leaks.
>>
>> Should this leak fix go into 3.0?
>
> It has been there for a while, but it could be fixed for 3.0 indeed.
>
>>
>>> When an error occurs, "qdict" contains the response, but we still
>>> check the "execute" key there.
>>
>> Harmless.
>>
>>> Untangle a bit this code, by having a
>>> clear error path.
>>
>> Untangling might make sense anyway. Let's see.
>>
>>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>>> ---
>>> qga/main.c | 50 +++++++++++++++++++++++++-------------------------
>>> 1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/qga/main.c b/qga/main.c
>>> index 537cc0e162..0784761605 100644
>>> --- a/qga/main.c
>>> +++ b/qga/main.c
>>> @@ -600,6 +600,7 @@ static void process_command(GAState *s, QDict *req)
>>> static void process_event(JSONMessageParser *parser, GQueue *tokens)
>>> {
>>> GAState *s = container_of(parser, GAState, parser);
>>> + QObject *obj;
>>> QDict *qdict;
>>> Error *err = NULL;
>>> int ret;
>>> @@ -607,35 +608,34 @@ static void process_event(JSONMessageParser *parser, GQueue *tokens)
>>> g_assert(s && parser);
>>>
>>> g_debug("process_event: called");
>>> - qdict = qobject_to(QDict, json_parser_parse_err(tokens, NULL, &err));
>>> - if (err || !qdict) {
>>> - qobject_unref(qdict);
>>> - if (!err) {
>>> - g_warning("failed to parse event: unknown error");
>>> - error_setg(&err, QERR_JSON_PARSING);
>>> - } else {
>>> - g_warning("failed to parse event: %s", error_get_pretty(err));
>>> - }
>>> - qdict = qmp_error_response(err);
>>> + obj = json_parser_parse_err(tokens, NULL, &err);
>>> + if (err) {
>>> + goto err;
>>> }
>>> -
>>> - /* handle host->guest commands */
>>> - if (qdict_haskey(qdict, "execute")) {
>>> - process_command(s, qdict);
>>> - } else {
>>> - if (!qdict_haskey(qdict, "error")) {
>>> - qobject_unref(qdict);
>>> - g_warning("unrecognized payload format");
>>> - error_setg(&err, QERR_UNSUPPORTED);
>>> - qdict = qmp_error_response(err);
>>> - }
>>> - ret = send_response(s, qdict);
>>> - if (ret < 0) {
>>> - g_warning("error sending error response: %s", strerror(-ret));
>>> - }
>>> + qdict = qobject_to(QDict, obj);
>>> + if (!qdict) {
>>> + error_setg(&err, QERR_JSON_PARSING);
>>> + goto err;
>>> + }
>>> + if (!qdict_haskey(qdict, "execute")) {
>>> + g_warning("unrecognized payload format");
>>> + error_setg(&err, QERR_UNSUPPORTED);
>>> + goto err;
>>> }
>>>
>>> + process_command(s, qdict);
>>> + qobject_unref(obj);
>>> + return;
>>> +
>>> +err:
>>> + g_warning("failed to parse event: %s", error_get_pretty(err));
>>> + qdict = qmp_error_response(err);
>>> + ret = send_response(s, qdict);
>>> + if (ret < 0) {
>>> + g_warning("error sending error response: %s", strerror(-ret));
>>> + }
>>> qobject_unref(qdict);
>>> + qobject_unref(obj);
>>> }
>>>
>>> /* false return signals GAChannel to close the current client connection */
>>
>> Control flow is much improved. Took me a minute to convince myself the
>> reference counting is okay: qdict is a weak reference before qdict =
>> qmp_error_response(), and becomes strong there. Suggest to use a new
>> variable @err_rsp for the latter purpose.
>
> Yes, the code is further improved in patch 11.
Looking... yes, it looks quite nice after PATCH 11. Whether to make the
intermediate state after this patch a bit nicer just because we can is
Mike's call to make.
>> Regardless:
>> Reviewed-by: Markus Armbruster <armbru@redhat.com>
>>
>
> thanks
© 2016 - 2025 Red Hat, Inc.