V4L/DVB (5869): Add check for valid control ID to v4l2_ctrl_next.

If v4l2_ctrl_next is called without the V4L2_CTRL_FLAG_NEXT_CTRL then it 
should check whether the passed control ID is valid and return 0 if it 
isn't. Otherwise a for-loop over the control IDs will never end.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Hans Verkuil 2007-07-19 04:53:36 -03:00 коммит произвёл Mauro Carvalho Chehab
Родитель 3d58ffe2aa
Коммит a46c5fbc69
1 изменённых файлов: 14 добавлений и 5 удалений

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@ -939,16 +939,25 @@ int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu, struct v4l2_queryctrl *qc
When no more controls are available 0 is returned. */
u32 v4l2_ctrl_next(const u32 * const * ctrl_classes, u32 id)
{
u32 ctrl_class;
u32 ctrl_class = V4L2_CTRL_ID2CLASS(id);
const u32 *pctrl;
/* if no query is desired, then just return the control ID */
if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0)
return id;
if (ctrl_classes == NULL)
return 0;
/* if no query is desired, then check if the ID is part of ctrl_classes */
if ((id & V4L2_CTRL_FLAG_NEXT_CTRL) == 0) {
/* find class */
while (*ctrl_classes && V4L2_CTRL_ID2CLASS(**ctrl_classes) != ctrl_class)
ctrl_classes++;
if (*ctrl_classes == NULL)
return 0;
pctrl = *ctrl_classes;
/* find control ID */
while (*pctrl && *pctrl != id) pctrl++;
return *pctrl ? id : 0;
}
id &= V4L2_CTRL_ID_MASK;
ctrl_class = V4L2_CTRL_ID2CLASS(id);
id++; /* select next control */
/* find first class that matches (or is greater than) the class of
the ID */