HID: sony: Perform CRC check on bluetooth input packets

Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index 43bb24cc5fc3bea40446d547450592e41f7634d2..34988ce9434a1f2d7a7ee2828b91942375ac255d 100644 (file)
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -36,6 +36,8 @@
 #include <linux/list.h>
 #include <linux/idr.h>
 #include <linux/input/mt.h>
+#include <linux/crc32.h>
+#include <asm/unaligned.h>
 
 #include "hid-ids.h"
 
@@ -1021,6 +1023,7 @@ struct motion_output_report_02 {
 
 #define DS4_FEATURE_REPORT_0x02_SIZE 37
 #define DS4_FEATURE_REPORT_0x81_SIZE 7
+#define DS4_INPUT_REPORT_0x11_SIZE 78
 #define DS4_OUTPUT_REPORT_0x05_SIZE 32
 #define DS4_OUTPUT_REPORT_0x11_SIZE 78
 #define SIXAXIS_REPORT_0xF2_SIZE 17
@@ -1324,6 +1327,21 @@ static int sony_raw_event(struct hid_device *hdev, struct hid_report *report,
        } else if (((sc->quirks & DUALSHOCK4_CONTROLLER_USB) && rd[0] == 0x01 &&
                        size == 64) || ((sc->quirks & DUALSHOCK4_CONTROLLER_BT)
                        && rd[0] == 0x11 && size == 78)) {
+               if (sc->quirks & DUALSHOCK4_CONTROLLER_BT) {
+                       /* CRC check */
+                       u8 bthdr = 0xA1;
+                       u32 crc;
+                       u32 report_crc;
+
+                       crc = crc32_le(0xFFFFFFFF, &bthdr, 1);
+                       crc = ~crc32_le(crc, rd, DS4_INPUT_REPORT_0x11_SIZE-4);
+                       report_crc = get_unaligned_le32(&rd[DS4_INPUT_REPORT_0x11_SIZE-4]);
+                       if (crc != report_crc) {
+                               hid_dbg(sc->hdev, "DualShock 4 input report's CRC check failed, received crc 0x%0x != 0x%0x\n",
+                                       report_crc, crc);
+                               return -EILSEQ;
+                       }
+               }
                dualshock4_parse_report(sc, rd, size);
        }