+++ /dev/null
-/* -*- Mode: C; indent-tabs-mode:t ; c-basic-offset:8 -*- */
-/*
- * Hotplug functions for libusb
- * Copyright © 2012-2013 Nathan Hjelm <hjelmn@mac.com>
- * Copyright © 2012-2013 Peter Stuge <peter@stuge.se>
- *
- * 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 <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#ifdef HAVE_SYS_TYPES_H
-#include <sys/types.h>
-#endif
-#include <assert.h>
-
-#include "libusbi.h"
-#include "hotplug.h"
-
-/**
- * @defgroup libusb_hotplug Device hotplug event notification
- * This page details how to use the libusb hotplug interface, where available.
- *
- * Be mindful that not all platforms currently implement hotplug notification and
- * that you should first call on \ref libusb_has_capability() with parameter
- * \ref LIBUSB_CAP_HAS_HOTPLUG to confirm that hotplug support is available.
- *
- * \page libusb_hotplug Device hotplug event notification
- *
- * \section hotplug_intro Introduction
- *
- * Version 1.0.16, \ref LIBUSB_API_VERSION >= 0x01000102, has added support
- * for hotplug events on <b>some</b> platforms (you should test if your platform
- * supports hotplug notification by calling \ref libusb_has_capability() with
- * parameter \ref LIBUSB_CAP_HAS_HOTPLUG).
- *
- * This interface allows you to request notification for the arrival and departure
- * of matching USB devices.
- *
- * To receive hotplug notification you register a callback by calling
- * \ref libusb_hotplug_register_callback(). This function will optionally return
- * a callback handle that can be passed to \ref libusb_hotplug_deregister_callback().
- *
- * A callback function must return an int (0 or 1) indicating whether the callback is
- * expecting additional events. Returning 0 will rearm the callback and 1 will cause
- * the callback to be deregistered. Note that when callbacks are called from
- * libusb_hotplug_register_callback() because of the \ref LIBUSB_HOTPLUG_ENUMERATE
- * flag, the callback return value is ignored, iow you cannot cause a callback
- * to be deregistered by returning 1 when it is called from
- * libusb_hotplug_register_callback().
- *
- * Callbacks for a particular context are automatically deregistered by libusb_exit().
- *
- * As of 1.0.16 there are two supported hotplug events:
- * - LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED: A device has arrived and is ready to use
- * - LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT: A device has left and is no longer available
- *
- * A hotplug event can listen for either or both of these events.
- *
- * Note: If you receive notification that a device has left and you have any
- * a libusb_device_handles for the device it is up to you to call libusb_close()
- * on each device handle to free up any remaining resources associated with the device.
- * Once a device has left any libusb_device_handle associated with the device
- * are invalid and will remain so even if the device comes back.
- *
- * When handling a LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED event it is considered
- * safe to call any libusb function that takes a libusb_device. It also safe to
- * open a device and submit asynchronous transfers. However, most other functions
- * that take a libusb_device_handle are <b>not</b> safe to call. Examples of such
- * functions are any of the \ref libusb_syncio "synchronous API" functions or the blocking
- * functions that retrieve various \ref libusb_desc "USB descriptors". These functions must
- * be used outside of the context of the hotplug callback.
- *
- * When handling a LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT event the only safe function
- * is libusb_get_device_descriptor().
- *
- * The following code provides an example of the usage of the hotplug interface:
-\code
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include <libusb.h>
-
-static int count = 0;
-
-int hotplug_callback(struct libusb_context *ctx, struct libusb_device *dev,
- libusb_hotplug_event event, void *user_data) {
- static libusb_device_handle *dev_handle = NULL;
- struct libusb_device_descriptor desc;
- int rc;
-
- (void)libusb_get_device_descriptor(dev, &desc);
-
- if (LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED == event) {
- rc = libusb_open(dev, &dev_handle);
- if (LIBUSB_SUCCESS != rc) {
- printf("Could not open USB device\n");
- }
- } else if (LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT == event) {
- if (dev_handle) {
- libusb_close(dev_handle);
- dev_handle = NULL;
- }
- } else {
- printf("Unhandled event %d\n", event);
- }
- count++;
-
- return 0;
-}
-
-int main (void) {
- libusb_hotplug_callback_handle callback_handle;
- int rc;
-
- libusb_init(NULL);
-
- rc = libusb_hotplug_register_callback(NULL, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED |
- LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT, 0, 0x045a, 0x5005,
- LIBUSB_HOTPLUG_MATCH_ANY, hotplug_callback, NULL,
- &callback_handle);
- if (LIBUSB_SUCCESS != rc) {
- printf("Error creating a hotplug callback\n");
- libusb_exit(NULL);
- return EXIT_FAILURE;
- }
-
- while (count < 2) {
- libusb_handle_events_completed(NULL, NULL);
- nanosleep(&(struct timespec){0, 10000000UL}, NULL);
- }
-
- libusb_hotplug_deregister_callback(NULL, callback_handle);
- libusb_exit(NULL);
-
- return 0;
-}
-\endcode
- */
-
-static int usbi_hotplug_match_cb(struct libusb_context *ctx,
- struct libusb_device *dev, libusb_hotplug_event event,
- struct libusb_hotplug_callback *hotplug_cb)
-{
- if (!(hotplug_cb->flags & event)) {
- return 0;
- }
-
- if ((hotplug_cb->flags & USBI_HOTPLUG_VENDOR_ID_VALID) &&
- hotplug_cb->vendor_id != dev->device_descriptor.idVendor) {
- return 0;
- }
-
- if ((hotplug_cb->flags & USBI_HOTPLUG_PRODUCT_ID_VALID) &&
- hotplug_cb->product_id != dev->device_descriptor.idProduct) {
- return 0;
- }
-
- if ((hotplug_cb->flags & USBI_HOTPLUG_DEV_CLASS_VALID) &&
- hotplug_cb->dev_class != dev->device_descriptor.bDeviceClass) {
- return 0;
- }
-
- return hotplug_cb->cb(ctx, dev, event, hotplug_cb->user_data);
-}
-
-void usbi_hotplug_match(struct libusb_context *ctx, struct libusb_device *dev,
- libusb_hotplug_event event)
-{
- struct libusb_hotplug_callback *hotplug_cb, *next;
- int ret;
-
- usbi_mutex_lock(&ctx->hotplug_cbs_lock);
-
- list_for_each_entry_safe(hotplug_cb, next, &ctx->hotplug_cbs, list, struct libusb_hotplug_callback) {
- if (hotplug_cb->flags & USBI_HOTPLUG_NEEDS_FREE) {
- /* process deregistration in usbi_hotplug_deregister() */
- continue;
- }
-
- usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
- ret = usbi_hotplug_match_cb(ctx, dev, event, hotplug_cb);
- usbi_mutex_lock(&ctx->hotplug_cbs_lock);
-
- if (ret) {
- list_del(&hotplug_cb->list);
- free(hotplug_cb);
- }
- }
-
- usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
-}
-
-void usbi_hotplug_notification(struct libusb_context *ctx, struct libusb_device *dev,
- libusb_hotplug_event event)
-{
- int pending_events;
- struct libusb_hotplug_message *message = calloc(1, sizeof(*message));
-
- if (!message) {
- usbi_err(ctx, "error allocating hotplug message");
- return;
- }
-
- message->event = event;
- message->device = dev;
-
- /* Take the event data lock and add this message to the list.
- * Only signal an event if there are no prior pending events. */
- usbi_mutex_lock(&ctx->event_data_lock);
- pending_events = usbi_pending_events(ctx);
- list_add_tail(&message->list, &ctx->hotplug_msgs);
- if (!pending_events)
- usbi_signal_event(ctx);
- usbi_mutex_unlock(&ctx->event_data_lock);
-}
-
-int API_EXPORTED libusb_hotplug_register_callback(libusb_context *ctx,
- libusb_hotplug_event events, libusb_hotplug_flag flags,
- int vendor_id, int product_id, int dev_class,
- libusb_hotplug_callback_fn cb_fn, void *user_data,
- libusb_hotplug_callback_handle *callback_handle)
-{
- struct libusb_hotplug_callback *new_callback;
-
- /* check for sane values */
- if ((!events || (~(LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED | LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT) & events)) ||
- (flags && (~LIBUSB_HOTPLUG_ENUMERATE & flags)) ||
- (LIBUSB_HOTPLUG_MATCH_ANY != vendor_id && (~0xffff & vendor_id)) ||
- (LIBUSB_HOTPLUG_MATCH_ANY != product_id && (~0xffff & product_id)) ||
- (LIBUSB_HOTPLUG_MATCH_ANY != dev_class && (~0xff & dev_class)) ||
- !cb_fn) {
- return LIBUSB_ERROR_INVALID_PARAM;
- }
-
- /* check for hotplug support */
- if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) {
- return LIBUSB_ERROR_NOT_SUPPORTED;
- }
-
- USBI_GET_CONTEXT(ctx);
-
- new_callback = calloc(1, sizeof(*new_callback));
- if (!new_callback) {
- return LIBUSB_ERROR_NO_MEM;
- }
-
- new_callback->flags = (uint8_t)events;
- if (LIBUSB_HOTPLUG_MATCH_ANY != vendor_id) {
- new_callback->flags |= USBI_HOTPLUG_VENDOR_ID_VALID;
- new_callback->vendor_id = (uint16_t)vendor_id;
- }
- if (LIBUSB_HOTPLUG_MATCH_ANY != product_id) {
- new_callback->flags |= USBI_HOTPLUG_PRODUCT_ID_VALID;
- new_callback->product_id = (uint16_t)product_id;
- }
- if (LIBUSB_HOTPLUG_MATCH_ANY != dev_class) {
- new_callback->flags |= USBI_HOTPLUG_DEV_CLASS_VALID;
- new_callback->dev_class = (uint8_t)dev_class;
- }
- new_callback->cb = cb_fn;
- new_callback->user_data = user_data;
-
- usbi_mutex_lock(&ctx->hotplug_cbs_lock);
-
- /* protect the handle by the context hotplug lock */
- new_callback->handle = ctx->next_hotplug_cb_handle++;
-
- /* handle the unlikely case of overflow */
- if (ctx->next_hotplug_cb_handle < 0)
- ctx->next_hotplug_cb_handle = 1;
-
- list_add(&new_callback->list, &ctx->hotplug_cbs);
-
- usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
-
- usbi_dbg("new hotplug cb %p with handle %d", new_callback, new_callback->handle);
-
- if ((flags & LIBUSB_HOTPLUG_ENUMERATE) && (events & LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED)) {
- ssize_t i, len;
- struct libusb_device **devs;
-
- len = libusb_get_device_list(ctx, &devs);
- if (len < 0) {
- libusb_hotplug_deregister_callback(ctx,
- new_callback->handle);
- return (int)len;
- }
-
- for (i = 0; i < len; i++) {
- usbi_hotplug_match_cb(ctx, devs[i],
- LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED,
- new_callback);
- }
-
- libusb_free_device_list(devs, 1);
- }
-
-
- if (callback_handle)
- *callback_handle = new_callback->handle;
-
- return LIBUSB_SUCCESS;
-}
-
-void API_EXPORTED libusb_hotplug_deregister_callback(struct libusb_context *ctx,
- libusb_hotplug_callback_handle callback_handle)
-{
- struct libusb_hotplug_callback *hotplug_cb;
- int deregistered = 0;
-
- /* check for hotplug support */
- if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG)) {
- return;
- }
-
- USBI_GET_CONTEXT(ctx);
-
- usbi_dbg("deregister hotplug cb %d", callback_handle);
-
- usbi_mutex_lock(&ctx->hotplug_cbs_lock);
- list_for_each_entry(hotplug_cb, &ctx->hotplug_cbs, list, struct libusb_hotplug_callback) {
- if (callback_handle == hotplug_cb->handle) {
- /* Mark this callback for deregistration */
- hotplug_cb->flags |= USBI_HOTPLUG_NEEDS_FREE;
- deregistered = 1;
- }
- }
- usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
-
- if (deregistered) {
- int pending_events;
-
- usbi_mutex_lock(&ctx->event_data_lock);
- pending_events = usbi_pending_events(ctx);
- ctx->event_flags |= USBI_EVENT_HOTPLUG_CB_DEREGISTERED;
- if (!pending_events)
- usbi_signal_event(ctx);
- usbi_mutex_unlock(&ctx->event_data_lock);
- }
-}
-
-void usbi_hotplug_deregister(struct libusb_context *ctx, int forced)
-{
- struct libusb_hotplug_callback *hotplug_cb, *next;
-
- usbi_mutex_lock(&ctx->hotplug_cbs_lock);
- list_for_each_entry_safe(hotplug_cb, next, &ctx->hotplug_cbs, list, struct libusb_hotplug_callback) {
- if (forced || (hotplug_cb->flags & USBI_HOTPLUG_NEEDS_FREE)) {
- usbi_dbg("freeing hotplug cb %p with handle %d", hotplug_cb,
- hotplug_cb->handle);
- list_del(&hotplug_cb->list);
- free(hotplug_cb);
- }
- }
- usbi_mutex_unlock(&ctx->hotplug_cbs_lock);
-}
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