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HID: sony: Prevent duplicate controller connections. 

If a Sixaxis or Dualshock 4 controller is connected via USB while already
connected via Bluetooth it will cause duplicate devices to be added to the
input device list.

To prevent this a global list of controllers and their MAC addresses is
maintained and new controllers are checked against this list.  If a duplicate
is found, the probe function will exit with -EEXIST.

On USB the MAC is retrieved via a feature report.  On Bluetooth neither
controller reports the MAC address in a feature report so the MAC is parsed from
the uniq string.  As uniq cannot be guaranteed to be a MAC address in every case
(uHID or the behavior of HIDP changing) a parsing failure will not prevent the
connection.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Frank Praznik 2014-02-20 11:36:03 -05:00 committed by Jiri Kosina
parent ac3c9a9409
commit d2d782fcce
1 changed files with 140 additions and 0 deletions
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140
drivers/hid/hid-sony.c
View File

@ -33,6 +33,7 @@
#include <linux/leds.h>
#include <linux/power_supply.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/input/mt.h>
#include "hid-ids.h"
@ -717,8 +718,12 @@ static enum power_supply_property sony_battery_props[] = {
POWER_SUPPLY_PROP_STATUS,
};
static spinlock_t sony_dev_list_lock;
static LIST_HEAD(sony_device_list);
struct sony_sc {
spinlock_t lock;
struct list_head list_node;
struct hid_device *hdev;
struct led_classdev *leds[MAX_LEDS];
unsigned long quirks;
@ -730,6 +735,7 @@ struct sony_sc {
__u8 right;
#endif
__u8 mac_address[6];
__u8 worker_initialized;
__u8 cable_state;
__u8 battery_charging;
@ -1489,6 +1495,133 @@ static int sony_register_touchpad(struct sony_sc *sc, int touch_count,
return 0;
}
/*
* If a controller is plugged in via USB while already connected via Bluetooth
* it will show up as two devices. A global list of connected controllers and
* their MAC addresses is maintained to ensure that a device is only connected
* once.
*/
static int sony_check_add_dev_list(struct sony_sc *sc)
{
struct sony_sc *entry;
unsigned long flags;
int ret;
spin_lock_irqsave(&sony_dev_list_lock, flags);
list_for_each_entry(entry, &sony_device_list, list_node) {
ret = memcmp(sc->mac_address, entry->mac_address,
sizeof(sc->mac_address));
if (!ret) {
ret = -EEXIST;
hid_info(sc->hdev, "controller with MAC address %pMR already connected\n",
sc->mac_address);
goto unlock;
}
}
ret = 0;
list_add(&(sc->list_node), &sony_device_list);
unlock:
spin_unlock_irqrestore(&sony_dev_list_lock, flags);
return ret;
}
static void sony_remove_dev_list(struct sony_sc *sc)
{
unsigned long flags;
if (sc->list_node.next) {
spin_lock_irqsave(&sony_dev_list_lock, flags);
list_del(&(sc->list_node));
spin_unlock_irqrestore(&sony_dev_list_lock, flags);
}
}
static int sony_get_bt_devaddr(struct sony_sc *sc)
{
int ret;
/* HIDP stores the device MAC address as a string in the uniq field. */
ret = strlen(sc->hdev->uniq);
if (ret != 17)
return -EINVAL;
ret = sscanf(sc->hdev->uniq,
"%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
&sc->mac_address[5], &sc->mac_address[4], &sc->mac_address[3],
&sc->mac_address[2], &sc->mac_address[1], &sc->mac_address[0]);
if (ret != 6)
return -EINVAL;
return 0;
}
static int sony_check_add(struct sony_sc *sc)
{
int n, ret;
if ((sc->quirks & DUALSHOCK4_CONTROLLER_BT) ||
(sc->quirks & SIXAXIS_CONTROLLER_BT)) {
/*
* sony_get_bt_devaddr() attempts to parse the Bluetooth MAC
* address from the uniq string where HIDP stores it.
* As uniq cannot be guaranteed to be a MAC address in all cases
* a failure of this function should not prevent the connection.
*/
if (sony_get_bt_devaddr(sc) < 0) {
hid_warn(sc->hdev, "UNIQ does not contain a MAC address; duplicate check skipped\n");
return 0;
}
} else if (sc->quirks & DUALSHOCK4_CONTROLLER_USB) {
__u8 buf[7];
/*
* The MAC address of a DS4 controller connected via USB can be
* retrieved with feature report 0x81. The address begins at
* offset 1.
*/
ret = hid_hw_raw_request(sc->hdev, 0x81, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
if (ret != 7) {
hid_err(sc->hdev, "failed to retrieve feature report 0x81 with the DualShock 4 MAC address\n");
return ret < 0 ? ret : -EINVAL;
}
memcpy(sc->mac_address, &buf[1], sizeof(sc->mac_address));
} else if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
__u8 buf[18];
/*
* The MAC address of a Sixaxis controller connected via USB can
* be retrieved with feature report 0xf2. The address begins at
* offset 4.
*/
ret = hid_hw_raw_request(sc->hdev, 0xf2, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
if (ret != 18) {
hid_err(sc->hdev, "failed to retrieve feature report 0xf2 with the Sixaxis MAC address\n");
return ret < 0 ? ret : -EINVAL;
}
/*
* The Sixaxis device MAC in the report is big-endian and must
* be byte-swapped.
*/
for (n = 0; n < 6; n++)
sc->mac_address[5-n] = buf[4+n];
} else {
return 0;
}
return sony_check_add_dev_list(sc);
}
static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
int ret;
@ -1556,6 +1689,10 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = 0;
}
if (ret < 0)
goto err_stop;
ret = sony_check_add(sc);
if (ret < 0)
goto err_stop;
@ -1594,6 +1731,7 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
sony_battery_remove(sc);
if (sc->worker_initialized)
cancel_work_sync(&sc->state_worker);
sony_remove_dev_list(sc);
hid_hw_stop(hdev);
return ret;
}
@ -1613,6 +1751,8 @@ static void sony_remove(struct hid_device *hdev)
if (sc->worker_initialized)
cancel_work_sync(&sc->state_worker);
sony_remove_dev_list(sc);
hid_hw_stop(hdev);
}