On Thu, Aug 26, 2021 at 02:59:17PM -0700, William Douglas wrote:
> The virCHMonitorGet function needed to be able to return data from the
> hypervisor. This functionality is needed in order for the driver to
> support PTY enablement and getting details about the VM state.
>
> Signed-off-by: William Douglas <william.douglas@xxxxxxxxx>
> ---
> src/ch/ch_monitor.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/src/ch/ch_monitor.c b/src/ch/ch_monitor.c
> index b4bc10bfcf..ee7e4683e3 100644
> --- a/src/ch/ch_monitor.c
> +++ b/src/ch/ch_monitor.c
> @@ -611,12 +611,36 @@ virCHMonitorPutNoContent(virCHMonitor *mon, const char *endpoint)
> return ret;
> }
>
> +struct curl_data {
> + char *content;
> + size_t size;
> +};
> +
> +static size_t
> +curl_callback(void *contents, size_t size, size_t nmemb, void *userp)
> +{
> + size_t content_size = size * nmemb;
> + struct curl_data *data = (struct curl_data *)userp;
> +
> + if (content_size == 0)
> + return content_size;
> +
> + data->content = g_realloc(data->content, data->size + content_size);
> +
> + memcpy(&(data->content[data->size]), contents, content_size);
> + data->size += content_size;
> +
> + return content_size;
> +}
> +
> static int
> -virCHMonitorGet(virCHMonitor *mon, const char *endpoint)
> +virCHMonitorGet(virCHMonitor *mon, const char *endpoint, virJSONValue **response)
> {
> g_autofree char *url = NULL;
> int responseCode = 0;
> int ret = -1;
> + struct curl_slist *headers = NULL;
> + struct curl_data data = {0};
>
> url = g_strdup_printf("%s/%s", URL_ROOT, endpoint);
>
> @@ -628,12 +652,28 @@ virCHMonitorGet(virCHMonitor *mon, const char *endpoint)
> curl_easy_setopt(mon->handle, CURLOPT_UNIX_SOCKET_PATH, mon->socketpath);
> curl_easy_setopt(mon->handle, CURLOPT_URL, url);
>
> + if (response) {
> + headers = curl_slist_append(headers, "Accept: application/json");
> + headers = curl_slist_append(headers, "Content-Type: application/json");
> + curl_easy_setopt(mon->handle, CURLOPT_HTTPHEADER, headers);
> + curl_easy_setopt(mon->handle, CURLOPT_WRITEFUNCTION, curl_callback);
> + curl_easy_setopt(mon->handle, CURLOPT_WRITEDATA, (void *)&data);
This bit feels dodgy to me. mon->handle has its lifetime tied to
the virCHMonitor object, but '&data' is allocated on the stack.
IOW, this pointer is persistent, but it goes out of scope.
I guess you're relying on the fact that calls to this method are
serialized, and we re-write the bad pointer on every call, but
if 'response' is NULL on the next call we're not going to do that
re-write.
Can all these options be set unconditionally when the mon->handle
is first created ?
> + }
> +
> responseCode = virCHMonitorCurlPerform(mon->handle);
>
> virObjectUnlock(mon);
>
> - if (responseCode == 200 || responseCode == 204)
> + if (responseCode == 200 || responseCode == 204) {
> ret = 0;
> + if (response) {
> + data.content = g_realloc(data.content, data.size + 1);
> + data.content[data.size] = 0;
> + *response = virJSONValueFromString(data.content);
> + }
> + }
> +
> + g_free(data.content);
>
> return ret;
> }
Regards,
Daniel
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