third_party/libwebrtc/moz-patch-stack/0027.patch

   1 From: Dan Minor <dminor@mozilla.com>
   2 Date: Wed, 8 Jul 2020 17:35:00 +0000
   3 Subject: Bug 1650572 - Check V4L2_CAP_DEVICE_CAPS before accessing
   4  device_caps; r=ng
   5
   6 The capabilities field is for the physical device, device_caps is for the
   7 specific /dev/videoX device that has been opened. The device_caps field is
   8 only populated if V4L2_CAP_DEVICE_CAPS is set, so we should check that, and
   9 fall back to capabilities if it is not set.
  10
  11 Differential Revision: https://phabricator.services.mozilla.com/D82377
  12 Mercurial Revision: https://hg.mozilla.org/mozilla-central/rev/b5acbf536c46a66c939a61bde34ad93b1977a604
  13 ---
  14  modules/video_capture/linux/device_info_v4l2.cc | 17 ++++++++++++-----
  15  modules/video_capture/linux/device_info_v4l2.h  |  3 +++
  16  2 files changed, 15 insertions(+), 5 deletions(-)
  17
  18 diff --git a/modules/video_capture/linux/device_info_v4l2.cc b/modules/video_capture/linux/device_info_v4l2.cc
  19 index a2435bcd4f..cd0ba6e3df 100644
  20 --- a/modules/video_capture/linux/device_info_v4l2.cc
  21 +++ b/modules/video_capture/linux/device_info_v4l2.cc
  22 @@ -220,8 +220,7 @@ uint32_t DeviceInfoV4l2::NumberOfDevices() {
  23      snprintf(device, sizeof(device), "/dev/video%d", n);
  24      if ((fd = open(device, O_RDONLY)) != -1) {
  25        // query device capabilities and make sure this is a video capture device
  26 -      if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0 ||
  27 -          !(cap.device_caps & V4L2_CAP_VIDEO_CAPTURE)) {
  28 +      if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0 || !IsVideoCaptureDevice(&cap)) {
  29          close(fd);
  30          continue;
  31        }
  32 @@ -252,8 +251,7 @@ int32_t DeviceInfoV4l2::GetDeviceName(uint32_t deviceNumber,
  33      snprintf(device, sizeof(device), "/dev/video%d", n);
  34      if ((fd = open(device, O_RDONLY)) != -1) {
  35        // query device capabilities and make sure this is a video capture device
  36 -      if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0 ||
  37 -          !(cap.device_caps & V4L2_CAP_VIDEO_CAPTURE)) {
  38 +      if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0 || !IsVideoCaptureDevice(&cap)) {
  39          close(fd);
  40          continue;
  41        }
  42 @@ -331,7 +329,7 @@ int32_t DeviceInfoV4l2::CreateCapabilityMap(const char* deviceUniqueIdUTF8) {
  43      struct v4l2_capability cap;
  44      if (ioctl(fd, VIDIOC_QUERYCAP, &cap) == 0) {
  45        // skip devices without video capture capability
  46 -      if (!(cap.device_caps & V4L2_CAP_VIDEO_CAPTURE)) {
  47 +      if (!IsVideoCaptureDevice(&cap)) {
  48          continue;
  49        }
  50
  51 @@ -393,6 +391,15 @@ bool DeviceInfoV4l2::IsDeviceNameMatches(const char* name,
  52    return false;
  53  }
  54
  55 +bool DeviceInfoV4l2::IsVideoCaptureDevice(struct v4l2_capability* cap)
  56 +{
  57 +  if (cap->capabilities & V4L2_CAP_DEVICE_CAPS) {
  58 +    return cap->device_caps & V4L2_CAP_VIDEO_CAPTURE;
  59 +  } else {
  60 +    return cap->capabilities & V4L2_CAP_VIDEO_CAPTURE;
  61 +  }
  62 +}
  63 +
  64  int32_t DeviceInfoV4l2::FillCapabilities(int fd) {
  65    // set image format
  66    struct v4l2_format video_fmt;
  67 diff --git a/modules/video_capture/linux/device_info_v4l2.h b/modules/video_capture/linux/device_info_v4l2.h
  68 index 95432a509d..e3c2395f49 100644
  69 --- a/modules/video_capture/linux/device_info_v4l2.h
  70 +++ b/modules/video_capture/linux/device_info_v4l2.h
  71 @@ -18,6 +18,8 @@
  72  #include "rtc_base/platform_thread.h"
  73  #include <sys/inotify.h>
  74
  75 +struct v4l2_capability;
  76 +
  77  namespace webrtc {
  78  namespace videocapturemodule {
  79  class DeviceInfoV4l2 : public DeviceInfoImpl {
  80 @@ -49,6 +51,7 @@ class DeviceInfoV4l2 : public DeviceInfoImpl {
  81
  82   private:
  83    bool IsDeviceNameMatches(const char* name, const char* deviceUniqueIdUTF8);
  84 +  bool IsVideoCaptureDevice(struct v4l2_capability* cap);
  85
  86  #ifdef WEBRTC_LINUX
  87    void HandleEvent(inotify_event* event, int fd);