[PATCH 4/6] HID: Add the HIDIOCGRAWCLIENTADDR ioctl to hidraw

[Frank Praznik <frank.praznik@oh.rr.com>]

Add a new HIDIOCGRAWCLIENTADDR ioctl to hidraw for retrieving the client
address.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
---
 drivers/hid/hidraw.c        | 19 +++++++++++++++++++
 include/uapi/linux/hidraw.h |  1 +
 2 files changed, 20 insertions(+)

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index cb0137b..07c328b 100644
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -447,6 +447,25 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
 						-EFAULT : len;
 					break;
 				}
+
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWCLIENTADDR(0))) {
+					char addr_str[32];
+					int len;
+					ret = snprintf(addr_str, sizeof(addr_str),
+							"%pMR", hid->client_addr);
+					if (ret < 0)
+						break;
+					else if (ret > sizeof(addr_str)-1)
+						len = sizeof(addr_str);
+					else
+						len = ret + 1;
+
+					if (len > _IOC_SIZE(cmd))
+						len = _IOC_SIZE(cmd);
+					ret = copy_to_user(user_arg, addr_str, len) ?
+						-EFAULT : len;
+					break;
+				}
 			}
 
 		ret = -ENOTTY;
diff --git a/include/uapi/linux/hidraw.h b/include/uapi/linux/hidraw.h
index f5b7329..5b6f4fa 100644
--- a/include/uapi/linux/hidraw.h
+++ b/include/uapi/linux/hidraw.h
@@ -38,6 +38,7 @@ struct hidraw_devinfo {
 /* The first byte of SFEATURE and GFEATURE is the report number */
 #define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
 #define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
+#define HIDIOCGRAWCLIENTADDR(len) _IOC(_IOC_READ, 'H', 0x08, len)
 
 #define HIDRAW_FIRST_MINOR 0
 #define HIDRAW_MAX_DEVICES 64
-- 
1.8.5.3