compat_ioctl: move isdn/capi ioctl translation into driver

Neither the old isdn4linux interface nor the newer mISDN stack
ever had working 32-bit compat mode as far as I can tell.

However, the CAPI stack has some ioctl commands that are
correctly listed in fs/compat_ioctl.c.

We can trivially move all of those into the corresponding
file that implement the native handlers by adding a compat_ioctl
redirect to that.

I did notice that treating CAPI_MANUFACTURER_CMD() as compatible
is broken, so I'm also adding a handler for that, realizing that
in all likelyhood, nobody is ever going to call it.

Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Cc: isdn4linux@listserv.isdn4linux.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index c92b405b7646..6fbe3949026c 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -950,6 +950,34 @@ capi_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	return ret;
 }
 
+#ifdef CONFIG_COMPAT
+static long
+capi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int ret;
+
+	if (cmd == CAPI_MANUFACTURER_CMD) {
+		struct {
+			compat_ulong_t cmd;
+			compat_uptr_t data;
+		} mcmd32;
+
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		if (copy_from_user(&mcmd32, compat_ptr(arg), sizeof(mcmd32)))
+			return -EFAULT;
+
+		mutex_lock(&capi_mutex);
+		ret = capi20_manufacturer(mcmd32.cmd, compat_ptr(mcmd32.data));
+		mutex_unlock(&capi_mutex);
+
+		return ret;
+	}
+
+	return capi_unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
 static int capi_open(struct inode *inode, struct file *file)
 {
 	struct capidev *cdev;
@@ -996,6 +1024,9 @@ static const struct file_operations capi_fops =
 	.write		= capi_write,
 	.poll		= capi_poll,
 	.unlocked_ioctl	= capi_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= capi_compat_ioctl,
+#endif
 	.open		= capi_open,
 	.release	= capi_release,
 };