1 /* -*- Mode: C; c-basic-offset:8 ; indent-tabs-mode:t -*- */
3 * Linux usbfs backend for libusb
4 * Copyright (C) 2007-2009 Daniel Drake <dsd@gentoo.org>
5 * Copyright (c) 2001 Johannes Erdfelt <johannes@erdfelt.com>
6 * Copyright (c) 2012-2013 Nathan Hjelm <hjelmn@mac.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "linux_usbfs.h"
35 static struct udev *udev_ctx = NULL;
36 static int udev_monitor_fd = -1;
37 static usbi_event_t udev_control_event = USBI_INVALID_EVENT;
38 static struct udev_monitor *udev_monitor = NULL;
39 static pthread_t linux_event_thread;
41 static void udev_hotplug_event(struct udev_device *udev_dev);
42 static void *linux_udev_event_thread_main(void *arg);
44 int linux_udev_start_event_monitor(void)
48 assert(udev_ctx == NULL);
49 udev_ctx = udev_new();
51 usbi_err(NULL, "could not create udev context");
55 udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
57 usbi_err(NULL, "could not initialize udev monitor");
61 r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", "usb_device");
63 usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
64 goto err_free_monitor;
67 if (udev_monitor_enable_receiving(udev_monitor)) {
68 usbi_err(NULL, "failed to enable the udev monitor");
69 goto err_free_monitor;
72 udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
74 #if defined(FD_CLOEXEC)
75 /* Make sure the udev file descriptor is marked as CLOEXEC */
76 r = fcntl(udev_monitor_fd, F_GETFD);
78 usbi_err(NULL, "failed to get udev monitor fd flags, errno=%d", errno);
79 goto err_free_monitor;
81 if (!(r & FD_CLOEXEC)) {
82 if (fcntl(udev_monitor_fd, F_SETFD, r | FD_CLOEXEC) == -1) {
83 usbi_err(NULL, "failed to set udev monitor fd flags, errno=%d", errno);
84 goto err_free_monitor;
89 /* Some older versions of udev are not non-blocking by default,
90 * so make sure this is set */
91 r = fcntl(udev_monitor_fd, F_GETFL);
93 usbi_err(NULL, "failed to get udev monitor fd status flags, errno=%d", errno);
94 goto err_free_monitor;
96 if (!(r & O_NONBLOCK)) {
97 if (fcntl(udev_monitor_fd, F_SETFL, r | O_NONBLOCK) == -1) {
98 usbi_err(NULL, "failed to set udev monitor fd status flags, errno=%d", errno);
99 goto err_free_monitor;
103 r = usbi_create_event(&udev_control_event);
105 usbi_err(NULL, "failed to create udev control event");
106 goto err_free_monitor;
109 r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
111 usbi_err(NULL, "failed to create hotplug event thread (%d)", r);
112 goto err_destroy_event;
115 return LIBUSB_SUCCESS;
118 usbi_destroy_event(&udev_control_event);
119 udev_control_event = (usbi_event_t)USBI_INVALID_EVENT;
121 udev_monitor_unref(udev_monitor);
123 udev_monitor_fd = -1;
125 udev_unref(udev_ctx);
128 return LIBUSB_ERROR_OTHER;
131 int linux_udev_stop_event_monitor(void)
135 assert(udev_ctx != NULL);
136 assert(udev_monitor != NULL);
137 assert(udev_monitor_fd != -1);
139 /* Signal the control event and wait for the thread to exit */
140 usbi_signal_event(&udev_control_event);
142 r = pthread_join(linux_event_thread, NULL);
144 usbi_warn(NULL, "failed to join hotplug event thread (%d)", r);
146 usbi_destroy_event(&udev_control_event);
147 udev_control_event = (usbi_event_t)USBI_INVALID_EVENT;
149 /* Release the udev monitor */
150 udev_monitor_unref(udev_monitor);
152 udev_monitor_fd = -1;
154 /* Clean up the udev context */
155 udev_unref(udev_ctx);
158 return LIBUSB_SUCCESS;
161 static void *linux_udev_event_thread_main(void *arg)
163 struct pollfd fds[] = {
164 { .fd = USBI_EVENT_OS_HANDLE(&udev_control_event),
165 .events = USBI_EVENT_POLL_EVENTS },
166 { .fd = udev_monitor_fd,
169 struct udev_device *udev_dev;
174 #if defined(HAVE_PTHREAD_SETNAME_NP)
175 r = pthread_setname_np(pthread_self(), "libusb_event");
177 usbi_warn(NULL, "failed to set hotplug event thread name, error=%d", r);
180 usbi_dbg(NULL, "udev event thread entering");
183 r = poll(fds, 2, -1);
185 /* check for temporary failure */
188 usbi_err(NULL, "poll() failed, errno=%d", errno);
191 if (fds[0].revents) {
192 /* activity on control event, exit */
195 if (fds[1].revents) {
196 usbi_mutex_static_lock(&linux_hotplug_lock);
197 udev_dev = udev_monitor_receive_device(udev_monitor);
199 udev_hotplug_event(udev_dev);
200 usbi_mutex_static_unlock(&linux_hotplug_lock);
204 usbi_dbg(NULL, "udev event thread exiting");
209 static int udev_device_info(struct libusb_context *ctx, int detached,
210 struct udev_device *udev_dev, uint8_t *busnum,
211 uint8_t *devaddr, const char **sys_name) {
212 const char *dev_node;
214 dev_node = udev_device_get_devnode(udev_dev);
216 return LIBUSB_ERROR_OTHER;
219 *sys_name = udev_device_get_sysname(udev_dev);
221 return LIBUSB_ERROR_OTHER;
224 return linux_get_device_address(ctx, detached, busnum, devaddr,
225 dev_node, *sys_name, -1);
228 static void udev_hotplug_event(struct udev_device *udev_dev)
230 const char *udev_action;
231 const char *sys_name = NULL;
232 uint8_t busnum = 0, devaddr = 0;
237 udev_action = udev_device_get_action(udev_dev);
242 detached = !strncmp(udev_action, "remove", 6);
244 r = udev_device_info(NULL, detached, udev_dev, &busnum, &devaddr, &sys_name);
245 if (LIBUSB_SUCCESS != r) {
249 usbi_dbg(NULL, "udev hotplug event. action: %s.", udev_action);
251 if (strncmp(udev_action, "add", 3) == 0) {
252 linux_hotplug_enumerate(busnum, devaddr, sys_name);
253 } else if (detached) {
254 linux_device_disconnected(busnum, devaddr);
255 } else if (strncmp(udev_action, "bind", 4) == 0) {
256 /* silently ignore "known unhandled" action */
258 usbi_err(NULL, "ignoring udev action %s", udev_action);
262 udev_device_unref(udev_dev);
265 int linux_udev_scan_devices(struct libusb_context *ctx)
267 struct udev_enumerate *enumerator;
268 struct udev_list_entry *devices, *entry;
269 struct udev_device *udev_dev;
270 const char *sys_name;
273 assert(udev_ctx != NULL);
275 enumerator = udev_enumerate_new(udev_ctx);
276 if (NULL == enumerator) {
277 usbi_err(ctx, "error creating udev enumerator");
278 return LIBUSB_ERROR_OTHER;
281 udev_enumerate_add_match_subsystem(enumerator, "usb");
282 udev_enumerate_add_match_property(enumerator, "DEVTYPE", "usb_device");
283 udev_enumerate_scan_devices(enumerator);
284 devices = udev_enumerate_get_list_entry(enumerator);
287 udev_list_entry_foreach(entry, devices) {
288 const char *path = udev_list_entry_get_name(entry);
289 uint8_t busnum = 0, devaddr = 0;
291 udev_dev = udev_device_new_from_syspath(udev_ctx, path);
293 r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
295 udev_device_unref(udev_dev);
299 linux_enumerate_device(ctx, busnum, devaddr, sys_name);
300 udev_device_unref(udev_dev);
303 udev_enumerate_unref(enumerator);
305 return LIBUSB_SUCCESS;
308 void linux_udev_hotplug_poll(void)
310 struct udev_device *udev_dev;
312 usbi_mutex_static_lock(&linux_hotplug_lock);
314 udev_dev = udev_monitor_receive_device(udev_monitor);
316 usbi_dbg(NULL, "Handling hotplug event from hotplug_poll");
317 udev_hotplug_event(udev_dev);
320 usbi_mutex_static_unlock(&linux_hotplug_lock);