From patchwork Tue Mar 24 20:28:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 3313 Return-Path: Received: from relay11.mail.gandi.net (relay11.mail.gandi.net [217.70.178.231]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 8CF5660411 for ; Tue, 24 Mar 2020 21:25:56 +0100 (CET) Received: from localhost.localdomain (2-224-242-101.ip172.fastwebnet.it [2.224.242.101]) (Authenticated sender: jacopo@jmondi.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 60155100010; Tue, 24 Mar 2020 20:25:55 +0000 (UTC) From: Jacopo Mondi To: linux-media@vger.kernel.org, libcamera-devel@lists.libcamera.org Cc: Jacopo Mondi , mchehab@kernel.org, hverkuil-cisco@xs4all.nl, sakari.ailus@linux.intel.com Date: Tue, 24 Mar 2020 21:28:42 +0100 Message-Id: <20200324202844.1518292-3-jacopo@jmondi.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200324202844.1518292-1-jacopo@jmondi.org> References: <20200324202844.1518292-1-jacopo@jmondi.org> MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH 2/4] media: v4l2-dev: Add v4l2_device_register_ro_subdev_node() X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Mar 2020 20:25:56 -0000 Add to the V4L2 code a function to register device nodes for video subdevices in read-only mode. Registering a device node in read-only mode is useful to expose to userspace the current sub-device configuration, without allowing application to change it by using the V4L2 subdevice ioctls. Signed-off-by: Jacopo Mondi --- drivers/media/v4l2-core/v4l2-device.c | 16 +++++++++++++++- drivers/media/v4l2-core/v4l2-subdev.c | 19 +++++++++++++++++++ include/media/v4l2-dev.h | 7 +++++++ include/media/v4l2-device.h | 10 ++++++++++ 4 files changed, 51 insertions(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c index 63d6b147b21e..6f9dba36eda1 100644 --- a/drivers/media/v4l2-core/v4l2-device.c +++ b/drivers/media/v4l2-core/v4l2-device.c @@ -188,7 +188,8 @@ static void v4l2_device_release_subdev_node(struct video_device *vdev) kfree(vdev); } -int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) +int __v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev, + bool read_only) { struct video_device *vdev; struct v4l2_subdev *sd; @@ -217,6 +218,8 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) vdev->fops = &v4l2_subdev_fops; vdev->release = v4l2_device_release_subdev_node; vdev->ctrl_handler = sd->ctrl_handler; + if (read_only) + vdev->flags |= V4L2_FL_RO_DEVNODE; err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1, sd->owner); if (err < 0) { @@ -254,8 +257,19 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) return err; } + +int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) +{ + return __v4l2_device_register_subdev_nodes(v4l2_dev, false); +} EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes); +int v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev) +{ + return __v4l2_device_register_subdev_nodes(v4l2_dev, true); +} +EXPORT_SYMBOL_GPL(v4l2_device_register_ro_subdev_nodes); + void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) { struct v4l2_device *v4l2_dev; diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index f725cd9b66b9..9247ee6c293f 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -331,6 +331,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) struct v4l2_fh *vfh = file->private_data; #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh); + bool ro_devnode = !!(vdev->flags & V4L2_FL_RO_DEVNODE); int rval; #endif @@ -453,6 +454,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) case VIDIOC_SUBDEV_S_FMT: { struct v4l2_subdev_format *format = arg; + if (format->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode) + return -EPERM; + memset(format->reserved, 0, sizeof(format->reserved)); memset(format->format.reserved, 0, sizeof(format->format.reserved)); return v4l2_subdev_call(sd, pad, set_fmt, subdev_fh->pad, format); @@ -480,6 +484,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) struct v4l2_subdev_crop *crop = arg; struct v4l2_subdev_selection sel; + if (crop->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode) + return -EPERM; + memset(crop->reserved, 0, sizeof(crop->reserved)); memset(&sel, 0, sizeof(sel)); sel.which = crop->which; @@ -521,6 +528,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) case VIDIOC_SUBDEV_S_FRAME_INTERVAL: { struct v4l2_subdev_frame_interval *fi = arg; + if (ro_devnode) + return -EPERM; + memset(fi->reserved, 0, sizeof(fi->reserved)); return v4l2_subdev_call(sd, video, s_frame_interval, arg); } @@ -544,6 +554,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) case VIDIOC_SUBDEV_S_SELECTION: { struct v4l2_subdev_selection *sel = arg; + if (sel->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode) + return -EPERM; + memset(sel->reserved, 0, sizeof(sel->reserved)); return v4l2_subdev_call( sd, pad, set_selection, subdev_fh->pad, sel); @@ -580,6 +593,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) return v4l2_subdev_call(sd, video, g_dv_timings, arg); case VIDIOC_SUBDEV_S_DV_TIMINGS: + if (ro_devnode) + return -EPERM; + return v4l2_subdev_call(sd, video, s_dv_timings, arg); case VIDIOC_SUBDEV_G_STD: @@ -588,6 +604,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) case VIDIOC_SUBDEV_S_STD: { v4l2_std_id *std = arg; + if (ro_devnode) + return -EPERM; + return v4l2_subdev_call(sd, video, s_std, *std); } diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h index 48531e57cc5a..029873a338f2 100644 --- a/include/media/v4l2-dev.h +++ b/include/media/v4l2-dev.h @@ -82,11 +82,18 @@ struct v4l2_ctrl_handler; * but the old crop API will still work as expected in order to preserve * backwards compatibility. * Never set this flag for new drivers. + * @V4L2_FL_RO_DEVNODE: + * indicates that the video device node is registered in read-only mode. + * The flag only applies to device nodes registered for sub-devices, it is + * set by the core when the sub-devices device nodes are registered with + * v4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl + * handler to restrict access to some ioctl calls. */ enum v4l2_video_device_flags { V4L2_FL_REGISTERED = 0, V4L2_FL_USES_V4L2_FH = 1, V4L2_FL_QUIRK_INVERTED_CROP = 2, + V4L2_FL_RO_DEVNODE = 3, }; /* Priority helper functions */ diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h index e0b8f2602670..0df667ba9938 100644 --- a/include/media/v4l2-device.h +++ b/include/media/v4l2-device.h @@ -183,6 +183,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); int __must_check v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev); +/** + * v4l2_device_register_ro_subdev_nodes - Registers read-only device nodes for + * all subdevs of the v4l2 device that are marked with the + * %V4L2_SUBDEV_FL_HAS_DEVNODE flag. + * + * @v4l2_dev: pointer to struct v4l2_device + */ +int __must_check +v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev); + /** * v4l2_subdev_notify - Sends a notification to v4l2_device. *