fdo-mirrors/upower
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/upower/upower.git synced 2026-05-01 02:07:57 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

hidpp: validate messages, retry if invalid

Browse source 
This prevents matching the wrong response packet, for example when
a mouse is moved while a packet is read. As a result, the reads are
more reliable and log spam is reduced.

Signed-off-by: Peter Wu <lekensteyn@gmail.com>
This commit is contained in:
Peter Wu 2013-08-06 19:38:38 +02:00 • committed by Martin Pitt
parent c830102ca7
commit 4a211e07c3
1 changed files with 78 additions and 34 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

112
src/linux/hidpp-device.c
View file

@ -54,7 +54,7 @@
#define HIDPP_READ_LONG_REGISTER_DEVICE_TYPE_GAMEPAD 0xb
#define HIDPP_READ_LONG_REGISTER_DEVICE_TYPE_JOYSTICK 0xc
#define HIDPP_ERR_INVALID_SUBID 0x8f
#define HIDPP_ERROR_MESSAGE 0x8f
/* HID++ 2.0 */
@ -145,6 +145,24 @@ typedef struct {
G_DEFINE_TYPE (HidppDevice, hidpp_device, G_TYPE_OBJECT)
#define HIDPP_DEVICE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), HIDPP_TYPE_DEVICE, HidppDevicePrivate))
/**
* hidpp_is_error:
*
* Checks whether a message is a protocol-level error.
*/
static gboolean
hidpp_is_error(HidppMessage *msg, guchar *error)
{
if (msg->type == HIDPP_MSG_TYPE_SHORT &&
msg->feature_idx == HIDPP_ERROR_MESSAGE) {
if (error)
*error = msg->s.params[1];
return TRUE;
}
return FALSE;
}
/**
* hidpp_device_map_print:
**/
@ -266,6 +284,7 @@ hidpp_device_cmd (HidppDevice *device,
gssize wrote;
HidppMessage read_msg = { 0 };
guint msg_len;
guchar error_code;
HidppDevicePrivate *priv = device->priv;
GPollFD poll[] = {
{
@ -273,6 +292,8 @@ hidpp_device_cmd (HidppDevice *device,
.events = G_IO_IN | G_IO_OUT | G_IO_ERR,
},
};
guint64 begin_time;
gint remaining_time;
g_assert (request->type == HIDPP_MSG_TYPE_SHORT ||
request->type == HIDPP_MSG_TYPE_LONG);
@ -292,41 +313,64 @@ hidpp_device_cmd (HidppDevice *device,
}
/* read from the device */
// TODO: keep reading until wanted message is found
wrote = g_poll (poll, G_N_ELEMENTS(poll),
HIDPP_DEVICE_READ_RESPONSE_TIMEOUT);
if (wrote <= 0) {
g_set_error (error, 1, 0,
"Attempt to read response from device timed out: %" G_GSIZE_FORMAT,
wrote);
ret = FALSE;
goto out;
begin_time = g_get_monotonic_time () / 1000;
remaining_time = HIDPP_DEVICE_READ_RESPONSE_TIMEOUT;
for (;;) {
wrote = g_poll (poll, G_N_ELEMENTS(poll), remaining_time);
if (wrote <= 0) {
g_set_error (error, 1, 0,
"Attempt to read response from device timed out: %" G_GSIZE_FORMAT,
wrote);
ret = FALSE;
goto out;
}
wrote = read (priv->fd, &read_msg, sizeof (*response));
if (wrote <= 0) {
g_set_error (error, 1, 0,
"Unable to read response from device: %" G_GSIZE_FORMAT,
wrote);
ret = FALSE;
goto out;
}
hidpp_device_print_buffer (device, response);
/* validate response */
if (read_msg.type != HIDPP_MSG_TYPE_SHORT &&
read_msg.type != HIDPP_MSG_TYPE_LONG) {
/* ignore key presses, mouse motions, etc. */
continue;
}
if (read_msg.feature_idx == request->feature_idx &&
read_msg.function_idx == request->function_idx) {
break;
}
/* recognize HID++ 1.0 errors */
if (hidpp_is_error(&read_msg, &error_code) &&
read_msg.function_idx == request->feature_idx &&
read_msg.s.params[0] == request->function_idx) {
g_set_error (error, 1, 0,
"Unable to satisfy request, HID++ error %02x", error_code);
ret = FALSE;
goto out;
}
/* avoid infinite loop when there is no response */
remaining_time = HIDPP_DEVICE_READ_RESPONSE_TIMEOUT -
(g_get_monotonic_time () / 1000 - begin_time);
if (remaining_time <= 0) {
g_set_error (error, 1, 0,
"timeout while reading response");
ret = FALSE;
goto out;
}
/* not our message, ignore it and try again */
}
wrote = read (priv->fd, &read_msg, sizeof (*response));
if (wrote <= 0) {
g_set_error (error, 1, 0,
"Unable to read response from device: %" G_GSIZE_FORMAT,
wrote);
ret = FALSE;
goto out;
}
hidpp_device_print_buffer (device, response);
// TODO: test for invalid reply
#if 0
if ((buf[0] != HIDPP_HEADER_REQUEST && buf[0] != HIDPP_HEADER_RESPONSE) ||
buf[1] != device_idx ||
buf[2] != feature_idx ||
buf[3] != function_idx) {
g_set_error (error, 1, 0,
"invalid response from device: %" G_GSIZE_FORMAT,
wrote);
ret = FALSE;
goto out;
}
#endif
out:
/* allow caller to check for protocol errors */
memcpy (response, &read_msg, sizeof (read_msg));