/* -*- 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 "config.h"
#include <assert.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/socket.h>
#include <unistd.h>
#include <libudev.h>
#include "libusb.h"
#include "libusbi.h"
#include "linux_usbfs.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");
return LIBUSB_ERROR_OTHER;
}
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", 0);
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);
/* 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, "getting udev monitor fd flags (%d)", errno);
goto err_free_monitor;
}
r = fcntl(udev_monitor_fd, F_SETFL, r | O_NONBLOCK);
if (r) {
usbi_err(NULL, "setting udev monitor fd flags (%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);
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 = usbi_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 __attribute__((unused)) *arg)
{
char dummy;
int r;
struct udev_device* udev_dev;
struct pollfd fds[] = {
{.fd = udev_control_pipe[0],
.events = POLLIN},
{.fd = udev_monitor_fd,
.events = POLLIN},
};
usbi_dbg("udev event thread entering.");
while (poll(fds, 2, -1) >= 0) {
if (fds[0].revents & POLLIN) {
/* activity on control pipe, read the byte and exit */
r = usbi_read(udev_control_pipe[0], &dummy, sizeof(dummy));
if (r <= 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);
}
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, sys_name);
} 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_scan_devices(enumerator);
devices = udev_enumerate_get_list_entry(enumerator);
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);
}
