| /* -*- 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 int udev_control_pipe[2] = {-1, -1}; |
| 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_pipe(udev_control_pipe); |
| if (r) { |
| usbi_err(NULL, "could not create udev control pipe"); |
| goto err_free_monitor; |
| } |
| |
| r = pthread_create(&linux_event_thread, NULL, linux_udev_event_thread_main, NULL); |
| if (r) { |
| usbi_err(NULL, "creating hotplug event thread (%d)", r); |
| goto err_close_pipe; |
| } |
| |
| return LIBUSB_SUCCESS; |
| |
| err_close_pipe: |
| close(udev_control_pipe[0]); |
| close(udev_control_pipe[1]); |
| 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) |
| { |
| char dummy = 1; |
| int r; |
| |
| assert(udev_ctx != NULL); |
| assert(udev_monitor != NULL); |
| assert(udev_monitor_fd != -1); |
| |
| /* Write some dummy data to the control pipe and |
| * wait for the thread to exit */ |
| r = write(udev_control_pipe[1], &dummy, sizeof(dummy)); |
| if (r <= 0) { |
| usbi_warn(NULL, "udev control pipe signal failed"); |
| } |
| pthread_join(linux_event_thread, NULL); |
| |
| /* 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; |
| |
| /* close and reset control pipe */ |
| close(udev_control_pipe[0]); |
| close(udev_control_pipe[1]); |
| udev_control_pipe[0] = -1; |
| udev_control_pipe[1] = -1; |
| |
| return LIBUSB_SUCCESS; |
| } |
| |
| static void *linux_udev_event_thread_main(void *arg) |
| { |
| char dummy; |
| int r; |
| ssize_t nb; |
| struct udev_device* udev_dev; |
| struct pollfd fds[] = { |
| {.fd = udev_control_pipe[0], |
| .events = POLLIN}, |
| {.fd = udev_monitor_fd, |
| .events = POLLIN}, |
| }; |
| |
| #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("udev event thread entering."); |
| |
| while ((r = poll(fds, 2, -1)) >= 0 || errno == EINTR) { |
| if (r < 0) { |
| /* temporary failure */ |
| continue; |
| } |
| if (fds[0].revents & POLLIN) { |
| /* activity on control pipe, read the byte and exit */ |
| nb = read(udev_control_pipe[0], &dummy, sizeof(dummy)); |
| if (nb <= 0) { |
| usbi_warn(NULL, "udev control pipe read failed"); |
| } |
| break; |
| } |
| if (fds[1].revents & POLLIN) { |
| 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("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("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("Handling hotplug event from hotplug_poll"); |
| udev_hotplug_event(udev_dev); |
| } |
| } while (udev_dev); |
| usbi_mutex_static_unlock(&linux_hotplug_lock); |
| } |