1 files changed, 321 insertions, 0 deletions
diff --git a/src/os/linux_udev.c b/src/os/linux_udev.c
new file mode 100644
index 0000000..9ec9eb1
--- /dev/null
+++ b/src/os/linux_udev.c
@@ -0,0 +1,321 @@
+/* -*- Mode: C; c-basic-offset:8 ; indent-tabs-mode:t -*- */
+/*
+ * Linux usbfs backend for libusb
+ * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
+ * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
+ * Copyright (c) 2012-2013 Nathan Hjelm <hjelmn@mac.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libusbi.h"
+#include "linux_usbfs.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <libudev.h>
+#include <poll.h>
+#include <pthread.h>
+#include <string.h>
+#include <unistd.h>
+
+/* udev context */
+static struct udev *udev_ctx = NULL;
+static int udev_monitor_fd = -1;
+static usbi_event_t udev_control_event = USBI_INVALID_EVENT;
+static struct udev_monitor *udev_monitor = NULL;
+static pthread_t linux_event_thread;
+
+static void udev_hotplug_event(struct udev_device *udev_dev);
+static void *linux_udev_event_thread_main(void *arg);
+
+int linux_udev_start_event_monitor(void)
+{
+	int r;
+
+	assert(udev_ctx == NULL);
+	udev_ctx = udev_new();
+	if (!udev_ctx) {
+		usbi_err(NULL, "could not create udev context");
+		goto err;
+	}
+
+	udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
+	if (!udev_monitor) {
+		usbi_err(NULL, "could not initialize udev monitor");
+		goto err_free_ctx;
+	}
+
+	r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", "usb_device");
+	if (r) {
+		usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
+		goto err_free_monitor;
+	}
+
+	if (udev_monitor_enable_receiving(udev_monitor)) {
+		usbi_err(NULL, "failed to enable the udev monitor");
+		goto err_free_monitor;
+	}
+
+	udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
+
+#if defined(FD_CLOEXEC)
+	/* Make sure the udev file descriptor is marked as CLOEXEC */
+	r = fcntl(udev_monitor_fd, F_GETFD);
+	if (r == -1) {
+		usbi_err(NULL, "failed to get udev monitor fd flags, errno=%d", errno);
+		goto err_free_monitor;
+	}
+	if (!(r & FD_CLOEXEC)) {
+		if (fcntl(udev_monitor_fd, F_SETFD, r | FD_CLOEXEC) == -1) {
+			usbi_err(NULL, "failed to set udev monitor fd flags, errno=%d", errno);
+			goto err_free_monitor;
+		}
+	}
+#endif
+
+	/* Some older versions of udev are not non-blocking by default,
+	 * so make sure this is set */
+	r = fcntl(udev_monitor_fd, F_GETFL);
+	if (r == -1) {
+		usbi_err(NULL, "failed to get udev monitor fd status flags, errno=%d", errno);
+		goto err_free_monitor;
+	}
+	if (!(r & O_NONBLOCK)) {
+		if (fcntl(udev_monitor_fd, F_SETFL, r | O_NONBLOCK) == -1) {
+			usbi_err(NULL, "failed to set udev monitor fd status flags, errno=%d", errno);
+			goto err_free_monitor;
+		}
+	}
+
+	r = usbi_create_event(&udev_control_event);
+	if (r) {
+		usbi_err(NULL, "failed to create udev control event");
+		goto err_free_monitor;
+	}
+
+	r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
+	if (r) {
+		usbi_err(NULL, "failed to create hotplug event thread (%d)", r);
+		goto err_destroy_event;
+	}
+
+	return LIBUSB_SUCCESS;
+
+err_destroy_event:
+	usbi_destroy_event(&udev_control_event);
+	udev_control_event = (usbi_event_t)USBI_INVALID_EVENT;
+err_free_monitor:
+	udev_monitor_unref(udev_monitor);
+	udev_monitor = NULL;
+	udev_monitor_fd = -1;
+err_free_ctx:
+	udev_unref(udev_ctx);
+err:
+	udev_ctx = NULL;
+	return LIBUSB_ERROR_OTHER;
+}
+
+int linux_udev_stop_event_monitor(void)
+{
+	int r;
+
+	assert(udev_ctx != NULL);
+	assert(udev_monitor != NULL);
+	assert(udev_monitor_fd != -1);
+
+	/* Signal the control event and wait for the thread to exit */
+	usbi_signal_event(&udev_control_event);
+
+	r = pthread_join(linux_event_thread, NULL);
+	if (r)
+		usbi_warn(NULL, "failed to join hotplug event thread (%d)", r);
+
+	usbi_destroy_event(&udev_control_event);
+	udev_control_event = (usbi_event_t)USBI_INVALID_EVENT;
+
+	/* Release the udev monitor */
+	udev_monitor_unref(udev_monitor);
+	udev_monitor = NULL;
+	udev_monitor_fd = -1;
+
+	/* Clean up the udev context */
+	udev_unref(udev_ctx);
+	udev_ctx = NULL;
+
+	return LIBUSB_SUCCESS;
+}
+
+static void *linux_udev_event_thread_main(void *arg)
+{
+	struct pollfd fds[] = {
+		{ .fd = USBI_EVENT_OS_HANDLE(&udev_control_event),
+		  .events = USBI_EVENT_POLL_EVENTS },
+		{ .fd = udev_monitor_fd,
+		  .events = POLLIN },
+	};
+	struct udev_device *udev_dev;
+	int r;
+
+	UNUSED(arg);
+
+#if defined(HAVE_PTHREAD_SETNAME_NP)
+	r = pthread_setname_np(pthread_self(), "libusb_event");
+	if (r)
+		usbi_warn(NULL, "failed to set hotplug event thread name, error=%d", r);
+#endif
+
+	usbi_dbg(NULL, "udev event thread entering");
+
+	while (1) {
+		r = poll(fds, 2, -1);
+		if (r == -1) {
+			/* check for temporary failure */
+			if (errno == EINTR)
+				continue;
+			usbi_err(NULL, "poll() failed, errno=%d", errno);
+			break;
+		}
+		if (fds[0].revents) {
+			/* activity on control event, exit */
+			break;
+		}
+		if (fds[1].revents) {
+			usbi_mutex_static_lock(&linux_hotplug_lock);
+			udev_dev = udev_monitor_receive_device(udev_monitor);
+			if (udev_dev)
+				udev_hotplug_event(udev_dev);
+			usbi_mutex_static_unlock(&linux_hotplug_lock);
+		}
+	}
+
+	usbi_dbg(NULL, "udev event thread exiting");
+
+	return NULL;
+}
+
+static int udev_device_info(struct libusb_context *ctx, int detached,
+			    struct udev_device *udev_dev, uint8_t *busnum,
+			    uint8_t *devaddr, const char **sys_name) {
+	const char *dev_node;
+
+	dev_node = udev_device_get_devnode(udev_dev);
+	if (!dev_node) {
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	*sys_name = udev_device_get_sysname(udev_dev);
+	if (!*sys_name) {
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	return linux_get_device_address(ctx, detached, busnum, devaddr,
+					dev_node, *sys_name, -1);
+}
+
+static void udev_hotplug_event(struct udev_device *udev_dev)
+{
+	const char *udev_action;
+	const char *sys_name = NULL;
+	uint8_t busnum = 0, devaddr = 0;
+	int detached;
+	int r;
+
+	do {
+		udev_action = udev_device_get_action(udev_dev);
+		if (!udev_action) {
+			break;
+		}
+
+		detached = !strncmp(udev_action, "remove", 6);
+
+		r = udev_device_info(NULL, detached, udev_dev, &busnum, &devaddr, &sys_name);
+		if (LIBUSB_SUCCESS != r) {
+			break;
+		}
+
+		usbi_dbg(NULL, "udev hotplug event. action: %s.", udev_action);
+
+		if (strncmp(udev_action, "add", 3) == 0) {
+			linux_hotplug_enumerate(busnum, devaddr, sys_name);
+		} else if (detached) {
+			linux_device_disconnected(busnum, devaddr);
+		} else if (strncmp(udev_action, "bind", 4) == 0) {
+			/* silently ignore "known unhandled" action */
+		} else {
+			usbi_err(NULL, "ignoring udev action %s", udev_action);
+		}
+	} while (0);
+
+	udev_device_unref(udev_dev);
+}
+
+int linux_udev_scan_devices(struct libusb_context *ctx)
+{
+	struct udev_enumerate *enumerator;
+	struct udev_list_entry *devices, *entry;
+	struct udev_device *udev_dev;
+	const char *sys_name;
+	int r;
+
+	assert(udev_ctx != NULL);
+
+	enumerator = udev_enumerate_new(udev_ctx);
+	if (NULL == enumerator) {
+		usbi_err(ctx, "error creating udev enumerator");
+		return LIBUSB_ERROR_OTHER;
+	}
+
+	udev_enumerate_add_match_subsystem(enumerator, "usb");
+	udev_enumerate_add_match_property(enumerator, "DEVTYPE", "usb_device");
+	udev_enumerate_scan_devices(enumerator);
+	devices = udev_enumerate_get_list_entry(enumerator);
+
+	entry = NULL;
+	udev_list_entry_foreach(entry, devices) {
+		const char *path = udev_list_entry_get_name(entry);
+		uint8_t busnum = 0, devaddr = 0;
+
+		udev_dev = udev_device_new_from_syspath(udev_ctx, path);
+
+		r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
+		if (r) {
+			udev_device_unref(udev_dev);
+			continue;
+		}
+
+		linux_enumerate_device(ctx, busnum, devaddr, sys_name);
+		udev_device_unref(udev_dev);
+	}
+
+	udev_enumerate_unref(enumerator);
+
+	return LIBUSB_SUCCESS;
+}
+
+void linux_udev_hotplug_poll(void)
+{
+	struct udev_device *udev_dev;
+
+	usbi_mutex_static_lock(&linux_hotplug_lock);
+	do {
+		udev_dev = udev_monitor_receive_device(udev_monitor);
+		if (udev_dev) {
+			usbi_dbg(NULL, "Handling hotplug event from hotplug_poll");
+			udev_hotplug_event(udev_dev);
+		}
+	} while (udev_dev);
+	usbi_mutex_static_unlock(&linux_hotplug_lock);
+}