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
34 #include <sys/ioctl.h>
36 #include <sys/types.h>
37 #include <sys/utsname.h>
38 #include <sys/socket.h>
43 #include "linux_usbfs.h"
46 static struct udev *udev_ctx = NULL;
47 static int udev_monitor_fd = -1;
48 static int udev_control_pipe[2] = {-1, -1};
49 static struct udev_monitor *udev_monitor = NULL;
50 static pthread_t linux_event_thread;
52 static void udev_hotplug_event(struct udev_device* udev_dev);
53 static void *linux_udev_event_thread_main(void *arg);
55 int linux_udev_start_event_monitor(void)
59 assert(udev_ctx == NULL);
60 udev_ctx = udev_new();
62 usbi_err(NULL, "could not create udev context");
66 udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
68 usbi_err(NULL, "could not initialize udev monitor");
72 r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", "usb_device");
74 usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
75 goto err_free_monitor;
78 if (udev_monitor_enable_receiving(udev_monitor)) {
79 usbi_err(NULL, "failed to enable the udev monitor");
80 goto err_free_monitor;
83 udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
85 #if defined(FD_CLOEXEC)
86 /* Make sure the udev file descriptor is marked as CLOEXEC */
87 r = fcntl(udev_monitor_fd, F_GETFD);
89 usbi_err(NULL, "failed to get udev monitor fd flags, errno=%d", errno);
90 goto err_free_monitor;
92 if (!(r & FD_CLOEXEC)) {
93 if (fcntl(udev_monitor_fd, F_SETFD, r | FD_CLOEXEC) == -1) {
94 usbi_err(NULL, "failed to set udev monitor fd flags, errno=%d", errno);
95 goto err_free_monitor;
100 /* Some older versions of udev are not non-blocking by default,
101 * so make sure this is set */
102 r = fcntl(udev_monitor_fd, F_GETFL);
104 usbi_err(NULL, "failed to get udev monitor fd status flags, errno=%d", errno);
105 goto err_free_monitor;
107 if (!(r & O_NONBLOCK)) {
108 if (fcntl(udev_monitor_fd, F_SETFL, r | O_NONBLOCK) == -1) {
109 usbi_err(NULL, "failed to set udev monitor fd status flags, errno=%d", errno);
110 goto err_free_monitor;
114 r = usbi_pipe(udev_control_pipe);
116 usbi_err(NULL, "could not create udev control pipe");
117 goto err_free_monitor;
120 r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
122 usbi_err(NULL, "creating hotplug event thread (%d)", r);
126 return LIBUSB_SUCCESS;
129 close(udev_control_pipe[0]);
130 close(udev_control_pipe[1]);
132 udev_monitor_unref(udev_monitor);
134 udev_monitor_fd = -1;
136 udev_unref(udev_ctx);
139 return LIBUSB_ERROR_OTHER;
142 int linux_udev_stop_event_monitor(void)
147 assert(udev_ctx != NULL);
148 assert(udev_monitor != NULL);
149 assert(udev_monitor_fd != -1);
151 /* Write some dummy data to the control pipe and
152 * wait for the thread to exit */
153 r = write(udev_control_pipe[1], &dummy, sizeof(dummy));
155 usbi_warn(NULL, "udev control pipe signal failed");
157 pthread_join(linux_event_thread, NULL);
159 /* Release the udev monitor */
160 udev_monitor_unref(udev_monitor);
162 udev_monitor_fd = -1;
164 /* Clean up the udev context */
165 udev_unref(udev_ctx);
168 /* close and reset control pipe */
169 close(udev_control_pipe[0]);
170 close(udev_control_pipe[1]);
171 udev_control_pipe[0] = -1;
172 udev_control_pipe[1] = -1;
174 return LIBUSB_SUCCESS;
177 static void *linux_udev_event_thread_main(void *arg)
182 struct udev_device* udev_dev;
183 struct pollfd fds[] = {
184 {.fd = udev_control_pipe[0],
186 {.fd = udev_monitor_fd,
190 usbi_dbg("udev event thread entering.");
192 while ((r = poll(fds, 2, -1)) >= 0 || errno == EINTR) {
194 /* temporary failure */
197 if (fds[0].revents & POLLIN) {
198 /* activity on control pipe, read the byte and exit */
199 nb = read(udev_control_pipe[0], &dummy, sizeof(dummy));
201 usbi_warn(NULL, "udev control pipe read failed");
205 if (fds[1].revents & POLLIN) {
206 usbi_mutex_static_lock(&linux_hotplug_lock);
207 udev_dev = udev_monitor_receive_device(udev_monitor);
209 udev_hotplug_event(udev_dev);
210 usbi_mutex_static_unlock(&linux_hotplug_lock);
214 usbi_dbg("udev event thread exiting");
219 static int udev_device_info(struct libusb_context *ctx, int detached,
220 struct udev_device *udev_dev, uint8_t *busnum,
221 uint8_t *devaddr, const char **sys_name) {
222 const char *dev_node;
224 dev_node = udev_device_get_devnode(udev_dev);
226 return LIBUSB_ERROR_OTHER;
229 *sys_name = udev_device_get_sysname(udev_dev);
231 return LIBUSB_ERROR_OTHER;
234 return linux_get_device_address(ctx, detached, busnum, devaddr,
235 dev_node, *sys_name, -1);
238 static void udev_hotplug_event(struct udev_device* udev_dev)
240 const char* udev_action;
241 const char* sys_name = NULL;
242 uint8_t busnum = 0, devaddr = 0;
247 udev_action = udev_device_get_action(udev_dev);
252 detached = !strncmp(udev_action, "remove", 6);
254 r = udev_device_info(NULL, detached, udev_dev, &busnum, &devaddr, &sys_name);
255 if (LIBUSB_SUCCESS != r) {
259 usbi_dbg("udev hotplug event. action: %s.", udev_action);
261 if (strncmp(udev_action, "add", 3) == 0) {
262 linux_hotplug_enumerate(busnum, devaddr, sys_name);
263 } else if (detached) {
264 linux_device_disconnected(busnum, devaddr);
265 } else if (strncmp(udev_action, "bind", 4) == 0) {
266 /* silently ignore "known unhandled" action */
268 usbi_err(NULL, "ignoring udev action %s", udev_action);
272 udev_device_unref(udev_dev);
275 int linux_udev_scan_devices(struct libusb_context *ctx)
277 struct udev_enumerate *enumerator;
278 struct udev_list_entry *devices, *entry;
279 struct udev_device *udev_dev;
280 const char *sys_name;
283 assert(udev_ctx != NULL);
285 enumerator = udev_enumerate_new(udev_ctx);
286 if (NULL == enumerator) {
287 usbi_err(ctx, "error creating udev enumerator");
288 return LIBUSB_ERROR_OTHER;
291 udev_enumerate_add_match_subsystem(enumerator, "usb");
292 udev_enumerate_add_match_property(enumerator, "DEVTYPE", "usb_device");
293 udev_enumerate_scan_devices(enumerator);
294 devices = udev_enumerate_get_list_entry(enumerator);
297 udev_list_entry_foreach(entry, devices) {
298 const char *path = udev_list_entry_get_name(entry);
299 uint8_t busnum = 0, devaddr = 0;
301 udev_dev = udev_device_new_from_syspath(udev_ctx, path);
303 r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
305 udev_device_unref(udev_dev);
309 linux_enumerate_device(ctx, busnum, devaddr, sys_name);
310 udev_device_unref(udev_dev);
313 udev_enumerate_unref(enumerator);
315 return LIBUSB_SUCCESS;
318 void linux_udev_hotplug_poll(void)
320 struct udev_device* udev_dev;
322 usbi_mutex_static_lock(&linux_hotplug_lock);
324 udev_dev = udev_monitor_receive_device(udev_monitor);
326 usbi_dbg("Handling hotplug event from hotplug_poll");
327 udev_hotplug_event(udev_dev);
330 usbi_mutex_static_unlock(&linux_hotplug_lock);