V4L/DVB (8112): videodev: improve extended control support in video_ioctl2()

- add sanity checks for the extended controls argument.
- if the driver only supports extended controls, then convert
  old-style controls to an extended control callback.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
index 91902d5..5bf2256 100644 (file)
--- a/drivers/media/video/videodev.c
+++ b/drivers/media/video/videodev.c
@@ -710,6 +710,29 @@ static inline void v4l_print_ext_ctrls(unsigned int cmd,
        printk(KERN_CONT "\n");
 };
 
+static inline int check_ext_ctrls(struct v4l2_ext_controls *c)
+{
+       __u32 i;
+
+       /* zero the reserved fields */
+       c->reserved[0] = c->reserved[1] = 0;
+       for (i = 0; i < c->count; i++) {
+               c->controls[i].reserved2[0] = 0;
+               c->controls[i].reserved2[1] = 0;
+       }
+       /* V4L2_CID_PRIVATE_BASE cannot be used as control class
+        * when using extended controls. */
+       if (c->ctrl_class == V4L2_CID_PRIVATE_BASE)
+               return 0;
+       /* Check that all controls are from the same control class. */
+       for (i = 0; i < c->count; i++) {
+               if (V4L2_CTRL_ID2CLASS(c->controls[i].id) != c->ctrl_class) {
+                       c->error_idx = i;
+                       return 0;
+               }
+       }
+       return 1;
+}
 
 static int check_fmt (struct video_device *vfd, enum v4l2_buf_type type)
 {
@@ -1392,10 +1415,24 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
        {
                struct v4l2_control *p = arg;
 
-               if (!vfd->vidioc_g_ctrl)
+               if (vfd->vidioc_g_ctrl)
+                       ret = vfd->vidioc_g_ctrl(file, fh, p);
+               else if (vfd->vidioc_g_ext_ctrls) {
+                       struct v4l2_ext_controls ctrls;
+                       struct v4l2_ext_control ctrl;
+
+                       ctrls.ctrl_class = V4L2_CTRL_ID2CLASS(p->id);
+                       ctrls.count = 1;
+                       ctrls.controls = &ctrl;
+                       ctrl.id = p->id;
+                       ctrl.value = p->value;
+                       if (check_ext_ctrls(&ctrls)) {
+                               ret = vfd->vidioc_g_ext_ctrls(file, fh, &ctrls);
+                               if (ret == 0)
+                                       p->value = ctrl.value;
+                       }
+               } else
                        break;
-
-               ret = vfd->vidioc_g_ctrl(file, fh, p);
                if (!ret)
                        dbgarg(cmd, "id=0x%x, value=%d\n", p->id, p->value);
                else
@@ -1405,21 +1442,39 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
        case VIDIOC_S_CTRL:
        {
                struct v4l2_control *p = arg;
+               struct v4l2_ext_controls ctrls;
+               struct v4l2_ext_control ctrl;
 
-               if (!vfd->vidioc_s_ctrl)
+               if (!vfd->vidioc_s_ctrl && !vfd->vidioc_s_ext_ctrls)
                        break;
+
                dbgarg(cmd, "id=0x%x, value=%d\n", p->id, p->value);
 
-               ret = vfd->vidioc_s_ctrl(file, fh, p);
+               if (vfd->vidioc_s_ctrl) {
+                       ret = vfd->vidioc_s_ctrl(file, fh, p);
+                       break;
+               }
+               if (!vfd->vidioc_s_ext_ctrls)
+                       break;
+
+               ctrls.ctrl_class = V4L2_CTRL_ID2CLASS(p->id);
+               ctrls.count = 1;
+               ctrls.controls = &ctrl;
+               ctrl.id = p->id;
+               ctrl.value = p->value;
+               if (check_ext_ctrls(&ctrls))
+                       ret = vfd->vidioc_s_ext_ctrls(file, fh, &ctrls);
                break;
        }
        case VIDIOC_G_EXT_CTRLS:
        {
                struct v4l2_ext_controls *p = arg;
 
+               p->error_idx = p->count;
                if (!vfd->vidioc_g_ext_ctrls)
                        break;
-               ret = vfd->vidioc_g_ext_ctrls(file, fh, p);
+               if (check_ext_ctrls(p))
+                       ret = vfd->vidioc_g_ext_ctrls(file, fh, p);
                v4l_print_ext_ctrls(cmd, vfd, p, !ret);
                break;
        }
@@ -1427,22 +1482,24 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
        {
                struct v4l2_ext_controls *p = arg;
 
-               if (vfd->vidioc_s_ext_ctrls) {
-                       v4l_print_ext_ctrls(cmd, vfd, p, 1);
-
+               p->error_idx = p->count;
+               if (!vfd->vidioc_s_ext_ctrls)
+                       break;
+               v4l_print_ext_ctrls(cmd, vfd, p, 1);
+               if (check_ext_ctrls(p))
                        ret = vfd->vidioc_s_ext_ctrls(file, fh, p);
-               }
                break;
        }
        case VIDIOC_TRY_EXT_CTRLS:
        {
                struct v4l2_ext_controls *p = arg;
 
-               if (vfd->vidioc_try_ext_ctrls) {
-                       v4l_print_ext_ctrls(cmd, vfd, p, 1);
-
+               p->error_idx = p->count;
+               if (!vfd->vidioc_try_ext_ctrls)
+                       break;
+               v4l_print_ext_ctrls(cmd, vfd, p, 1);
+               if (check_ext_ctrls(p))
                        ret = vfd->vidioc_try_ext_ctrls(file, fh, p);
-               }
                break;
        }
        case VIDIOC_QUERYMENU: