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
32 #include <sys/ioctl.h>
34 #include <sys/types.h>
35 #include <sys/utsname.h>
36 #include <sys/socket.h>
42 #include "linux_usbfs.h"
45 static struct udev *udev_ctx = NULL;
46 static int udev_monitor_fd = -1;
47 static struct udev_monitor *udev_monitor = NULL;
48 static pthread_t linux_event_thread;
50 static void udev_hotplug_event(void);
51 static void *linux_udev_event_thread_main(void *arg);
53 int linux_udev_start_event_monitor(void)
57 if (NULL == udev_ctx) {
58 udev_ctx = udev_new();
60 return LIBUSB_ERROR_OTHER;
64 udev_monitor = udev_monitor_new_from_netlink(udev_ctx, "udev");
66 usbi_err(NULL, "could not initialize udev monitor");
67 return LIBUSB_ERROR_OTHER;
70 r = udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", 0);
72 usbi_err(NULL, "could not initialize udev monitor filter for \"usb\" subsystem");
73 return LIBUSB_ERROR_OTHER;
76 if (udev_monitor_enable_receiving(udev_monitor)) {
77 usbi_err(NULL, "failed to enable the udev monitor");
78 return LIBUSB_ERROR_OTHER;
81 udev_monitor_fd = udev_monitor_get_fd(udev_monitor);
83 pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL);
85 return LIBUSB_SUCCESS;
88 int linux_udev_stop_event_monitor(void)
90 if (-1 == udev_monitor_fd) {
91 /* this should never happen */
92 return LIBUSB_ERROR_OTHER;
95 /* Cancel the event thread. This is the only way to garauntee the thread
96 exits since closing the monitor fd won't necessarily cause poll
98 pthread_cancel(linux_event_thread);
100 /* Release the udev monitor */
101 udev_monitor_unref(udev_monitor);
103 udev_monitor_fd = -1;
105 /* Clean up the udev context */
106 udev_unref(udev_ctx);
109 return LIBUSB_SUCCESS;
112 static void *linux_udev_event_thread_main(void *arg)
114 struct pollfd fds = {.fd = udev_monitor_fd,
117 usbi_dbg("udev event thread entering.");
119 while (1 == poll(&fds, 1, -1)) {
120 if (NULL == udev_monitor || POLLIN != fds.revents) {
124 udev_hotplug_event();
127 usbi_dbg("udev event thread exiting");
132 static int udev_device_info(struct libusb_context *ctx, int detached,
133 struct udev_device *udev_dev, uint8_t *busnum,
134 uint8_t *devaddr, const char **sys_name) {
135 const char *dev_node;
137 dev_node = udev_device_get_devnode(udev_dev);
139 return LIBUSB_ERROR_OTHER;
142 *sys_name = udev_device_get_sysname(udev_dev);
144 return LIBUSB_ERROR_OTHER;
147 return linux_get_device_address(ctx, detached, busnum, devaddr,
148 dev_node, *sys_name);
151 static void udev_hotplug_event(void)
153 struct udev_device* udev_dev;
154 const char* udev_action;
155 const char* sys_name = NULL;
156 uint8_t busnum = 0, devaddr = 0;
160 if (NULL == udev_monitor) {
165 udev_dev = udev_monitor_receive_device(udev_monitor);
167 usbi_err(NULL, "failed to read data from udev monitor socket.");
171 udev_action = udev_device_get_action(udev_dev);
176 detached = !strncmp(udev_action, "remove", 6);
178 r = udev_device_info(NULL, detached, udev_dev, &busnum, &devaddr, &sys_name);
179 if (LIBUSB_SUCCESS != r) {
183 usbi_dbg("udev hotplug event. action: %s.", udev_action);
185 if (strncmp(udev_action, "add", 3) == 0) {
186 linux_hotplug_enumerate(busnum, devaddr, sys_name);
187 } else if (detached) {
188 linux_hotplug_disconnected(busnum, devaddr, sys_name);
190 usbi_err(NULL, "ignoring udev action %s", udev_action);
194 udev_device_unref(udev_dev);
197 int linux_udev_scan_devices(struct libusb_context *ctx)
199 struct udev_enumerate *enumerator;
200 struct udev_list_entry *devices, *entry;
201 struct udev_device *udev_dev;
202 const char *sys_name;
205 if (NULL == udev_ctx) {
206 udev_ctx = udev_new();
208 return LIBUSB_ERROR_OTHER;
212 enumerator = udev_enumerate_new(udev_ctx);
213 if (NULL == enumerator) {
214 usbi_err(ctx, "error creating udev enumerator");
215 return LIBUSB_ERROR_OTHER;
218 udev_enumerate_add_match_subsystem(enumerator, "usb");
219 udev_enumerate_scan_devices(enumerator);
220 devices = udev_enumerate_get_list_entry(enumerator);
222 udev_list_entry_foreach(entry, devices) {
223 const char *path = udev_list_entry_get_name(entry);
224 uint8_t busnum = 0, devaddr = 0;
226 udev_dev = udev_device_new_from_syspath(udev_ctx, path);
228 r = udev_device_info(ctx, 0, udev_dev, &busnum, &devaddr, &sys_name);
230 udev_device_unref(udev_dev);
234 linux_enumerate_device(ctx, busnum, devaddr, sys_name);
235 udev_device_unref(udev_dev);
238 udev_enumerate_unref(enumerator);
240 return LIBUSB_SUCCESS;