[PATCH] propagate scan failures over d-bus

[Dan Williams]

On Tue, 2014-04-08 at 17:59 -0700, quiche at chromium.org wrote:
> If we receive a scan request via D-Bus, and wpa_supplicant_scan_trigger
> fails, return the failure to the caller over D-Bus.

I would suggest making a new namespaced error for the scan failure,
which is API, instead of using a magic error string in the message.
This makes it easier for clients to depend on the error.

Copy and paste wpas_dbus_error_unknown_error(), rename it, and #define a
new WPAS_DBUS_ERROR_UNKNOWN_ERROR called perhaps
WPA_DBUS_ERROR_IFACE_SCAN_ERROR and defined to:

WPAS_DBUS_NEW_IFACE_INTERFACE ".ScanError"

since it's an interface (eg, network interface) specific error.

The error string passed to dbus_message_new_error() is simply
informational, and isn't supposed to be API in any way.

Dan

> Signed-hostap: mukesh agrawal <quiche at chromium.org>
> ---
>  wpa_supplicant/dbus/dbus_new_handlers.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/wpa_supplicant/dbus/dbus_new_handlers.c b/wpa_supplicant/dbus/dbus_new_handlers.c
> index 4d5e109..d4f9a77 100644
> --- a/wpa_supplicant/dbus/dbus_new_handlers.c
> +++ b/wpa_supplicant/dbus/dbus_new_handlers.c
> @@ -1221,7 +1221,10 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
>  				"passive scan");
>  			goto out;
>  		} else if (params.freqs && params.freqs[0]) {
> -			wpa_supplicant_trigger_scan(wpa_s, &params);
> +			if (wpa_supplicant_trigger_scan(wpa_s, &params)) {
> +				reply = wpas_dbus_error_unknown_error(
> +				message, "Scan request rejected");
> +			}
>  		} else {
>  			wpa_s->scan_req = 2;
>  			wpa_supplicant_req_scan(wpa_s, 0, 0);
> @@ -1231,7 +1234,10 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
>  			/* Add wildcard ssid */
>  			params.num_ssids++;
>  		}
> -		wpa_supplicant_trigger_scan(wpa_s, &params);
> +		if (wpa_supplicant_trigger_scan(wpa_s, &params)) {
> +			reply = wpas_dbus_error_unknown_error(
> +				message, "Scan request rejected");
> +		}
>  	} else {
>  		wpa_printf(MSG_DEBUG, "wpas_dbus_handler_scan[dbus]: "
>  			   "Unknown scan type: %s", type);