[PATCH 8/9] plugins/sixaxis: Add support for DualShock 4/PS4 cable pairing

[Bastien Nocera <hadess@hadess.net>]

From: Juha Kuikka <juha.kuikka@gmail.com>

This patch adds support for "pairing" a Dualshock4 controller over USB
into the sixaxis plugin, similarly to what the Sixaxis/PS3 controller
supported.

Actual bonding happens on first connection, but the device will be
marked as trusted when the agent replies.

This patch is based on DS4 supprt for sixpair tool by t0xicCode:
https://github.com/t0xicCode/sixpair/commit/975c38cb6cd61a2f0be350714f0f64cef5f0432c
---
 plugins/sixaxis.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 1 deletion(-)

diff --git a/plugins/sixaxis.c b/plugins/sixaxis.c
index b62834d72..eb15acb92 100644
--- a/plugins/sixaxis.c
+++ b/plugins/sixaxis.c
@@ -83,10 +83,34 @@ static int sixaxis_get_device_bdaddr(int fd, bdaddr_t *bdaddr)
 	return 0;
 }
 
+static int ds4_get_device_bdaddr(int fd, bdaddr_t *bdaddr)
+{
+	uint8_t buf[7];
+	int ret;
+
+	memset(buf, 0, sizeof(buf));
+
+	buf[0] = 0x81;
+
+	ret = ioctl(fd, HIDIOCGFEATURE(sizeof(buf)), buf);
+	if (ret < 0) {
+		error("ds4: failed to read device address (%s)",
+		      strerror(errno));
+		return ret;
+	}
+
+	/* address is little-endian on DS4 */
+	bacpy(bdaddr, (bdaddr_t*) (buf + 1));
+
+	return 0;
+}
+
 static int get_device_bdaddr(int fd, bdaddr_t *bdaddr, CablePairingType type)
 {
 	if (type == CABLE_PAIRING_SIXAXIS)
 		return sixaxis_get_device_bdaddr(fd, bdaddr);
+	else if (type == CABLE_PAIRING_DS4)
+		return ds4_get_device_bdaddr(fd, bdaddr);
 	return -1;
 }
 
@@ -111,10 +135,34 @@ static int sixaxis_get_master_bdaddr(int fd, bdaddr_t *bdaddr)
 	return 0;
 }
 
+static int ds4_get_master_bdaddr(int fd, bdaddr_t *bdaddr)
+{
+	uint8_t buf[16];
+	int ret;
+
+	memset(buf, 0, sizeof(buf));
+
+	buf[0] = 0x12;
+
+	ret = ioctl(fd, HIDIOCGFEATURE(sizeof(buf)), buf);
+	if (ret < 0) {
+		error("ds4: failed to read master address (%s)",
+		      strerror(errno));
+		return ret;
+	}
+
+	/* address is little-endian on DS4 */
+	bacpy(bdaddr, (bdaddr_t*) (buf + 10));
+
+	return 0;
+}
+
 static int get_master_bdaddr(int fd, bdaddr_t *bdaddr, CablePairingType type)
 {
 	if (type == CABLE_PAIRING_SIXAXIS)
 		return sixaxis_get_master_bdaddr(fd, bdaddr);
+	else if (type == CABLE_PAIRING_DS4)
+		return ds4_get_master_bdaddr(fd, bdaddr);
 	return -1;
 }
 
@@ -136,11 +184,33 @@ static int sixaxis_set_master_bdaddr(int fd, const bdaddr_t *bdaddr)
 	return ret;
 }
 
+static int ds4_set_master_bdaddr(int fd, const bdaddr_t *bdaddr)
+{
+	uint8_t buf[23];
+	int ret;
+
+	buf[0] = 0x13;
+	bacpy((bdaddr_t*) (buf + 1), bdaddr);
+	/* TODO: we could put the key here but
+	   there is no way to force a re-loading
+	   of link keys to the kernel from here. */
+	memset(buf + 7, 0, 16);
+
+	ret = ioctl(fd, HIDIOCSFEATURE(sizeof(buf)), buf);
+	if (ret < 0)
+		error("ds4: failed to write master address (%s)",
+		      strerror(errno));
+
+	return ret;
+}
+
 static int set_master_bdaddr(int fd, const bdaddr_t *bdaddr,
 					CablePairingType type)
 {
 	if (type == CABLE_PAIRING_SIXAXIS)
 		return sixaxis_set_master_bdaddr(fd, bdaddr);
+	else if (type == CABLE_PAIRING_DS4)
+		return ds4_set_master_bdaddr(fd, bdaddr);
 	return -1;
 }
 
@@ -279,7 +349,8 @@ static void device_added(struct udev_device *udevice)
 						&name,
 						&source,
 						&version);
-	if (type != CABLE_PAIRING_SIXAXIS)
+	if (type != CABLE_PAIRING_SIXAXIS &&
+	    type != CABLE_PAIRING_DS4)
 		return;
 	if (bus != BUS_USB)
 		return;
-- 
2.14.1