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- /* -*- 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);
- }
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