1 files changed, 163 insertions, 0 deletions
diff --git a/src/libcamera/device_enumerator_udev.cpp b/src/libcamera/device_enumerator_udev.cpp
new file mode 100644
index 00000000..cb2d21b9
--- /dev/null
+++ b/src/libcamera/device_enumerator_udev.cpp
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018-2019, Google Inc.
+ *
+ * device_enumerator_udev.cpp - udev-based device enumerator
+ */
+
+#include "device_enumerator_udev.h"
+
+#include <fcntl.h>
+#include <libudev.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include <libcamera/event_notifier.h>
+
+#include "log.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(DeviceEnumerator)
+
+DeviceEnumeratorUdev::DeviceEnumeratorUdev()
+	: udev_(nullptr)
+{
+}
+
+DeviceEnumeratorUdev::~DeviceEnumeratorUdev()
+{
+	delete notifier_;
+
+	if (monitor_)
+		udev_monitor_unref(monitor_);
+	if (udev_)
+		udev_unref(udev_);
+}
+
+int DeviceEnumeratorUdev::init()
+{
+	int ret;
+
+	if (udev_)
+		return -EBUSY;
+
+	udev_ = udev_new();
+	if (!udev_)
+		return -ENODEV;
+
+	monitor_ = udev_monitor_new_from_netlink(udev_, "udev");
+	if (!monitor_)
+		return -ENODEV;
+
+	ret = udev_monitor_filter_add_match_subsystem_devtype(monitor_, "media",
+							      nullptr);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+int DeviceEnumeratorUdev::enumerate()
+{
+	struct udev_enumerate *udev_enum = nullptr;
+	struct udev_list_entry *ents, *ent;
+	int ret;
+
+	udev_enum = udev_enumerate_new(udev_);
+	if (!udev_enum)
+		return -ENOMEM;
+
+	ret = udev_enumerate_add_match_subsystem(udev_enum, "media");
+	if (ret < 0)
+		goto done;
+
+	ret = udev_enumerate_scan_devices(udev_enum);
+	if (ret < 0)
+		goto done;
+
+	ents = udev_enumerate_get_list_entry(udev_enum);
+	if (!ents)
+		goto done;
+
+	udev_list_entry_foreach(ent, ents) {
+		struct udev_device *dev;
+		const char *devnode;
+		const char *syspath = udev_list_entry_get_name(ent);
+
+		dev = udev_device_new_from_syspath(udev_, syspath);
+		if (!dev) {
+			LOG(DeviceEnumerator, Warning)
+				<< "Failed to get device for '"
+				<< syspath << "', skipping";
+			continue;
+		}
+
+		devnode = udev_device_get_devnode(dev);
+		if (!devnode) {
+			udev_device_unref(dev);
+			ret = -ENODEV;
+			goto done;
+		}
+
+		addDevice(devnode);
+
+		udev_device_unref(dev);
+	}
+done:
+	udev_enumerate_unref(udev_enum);
+	if (ret < 0)
+		return ret;
+
+	ret = udev_monitor_enable_receiving(monitor_);
+	if (ret < 0)
+		return ret;
+
+	int fd = udev_monitor_get_fd(monitor_);
+	notifier_ = new EventNotifier(fd, EventNotifier::Read);
+	notifier_->activated.connect(this, &DeviceEnumeratorUdev::udevNotify);
+
+	return 0;
+}
+
+std::string DeviceEnumeratorUdev::lookupDeviceNode(int major, int minor)
+{
+	struct udev_device *device;
+	const char *name;
+	dev_t devnum;
+	std::string deviceNode = std::string();
+
+	devnum = makedev(major, minor);
+	device = udev_device_new_from_devnum(udev_, 'c', devnum);
+	if (!device)
+		return std::string();
+
+	name = udev_device_get_devnode(device);
+	if (name)
+		deviceNode = name;
+
+	udev_device_unref(device);
+
+	return deviceNode;
+}
+
+void DeviceEnumeratorUdev::udevNotify(EventNotifier *notifier)
+{
+	struct udev_device *dev = udev_monitor_receive_device(monitor_);
+	std::string action(udev_device_get_action(dev));
+	std::string deviceNode(udev_device_get_devnode(dev));
+
+	LOG(DeviceEnumerator, Debug)
+		<< action << " device " << udev_device_get_devnode(dev);
+
+	if (action == "add") {
+		addDevice(deviceNode);
+	} else if (action == "remove") {
+		removeDevice(deviceNode);
+	}
+
+	udev_device_unref(dev);
+}
+
+} /* namespace libcamera */