From: Frank Praznik Date: Thu, 20 Feb 2014 16:36:03 +0000 (-0500) Subject: HID: sony: Prevent duplicate controller connections. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d2d782fccee4f699a35e2d0cdbb2b19bdaec95a4;p=linux-beck.git 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 Reviewed-by: David Herrmann Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c index b39e3abd6cdd..b1aa6f00c827 100644 --- a/drivers/hid/hid-sony.c +++ b/drivers/hid/hid-sony.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #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 @@ err_stop: 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); }