Implement libusb_hotplug_register_callback() and

libusb_hotplug_deregister_callback() for the LibUSB v1.0 API and
update the libusb(3) manual page.

Approved by:	re (kib)
Requested by:	swills
MFC after:	1 week
This commit is contained in:
Hans Petter Selasky 2016-06-22 10:38:41 +00:00
parent bbd41717f0
commit 7bdc064b0b
6 changed files with 349 additions and 1 deletions

View File

@ -32,6 +32,7 @@ SRCS+= libusb01.c
INCS+= libusb.h
SRCS+= libusb10.c
SRCS+= libusb10_desc.c
SRCS+= libusb10_hotplug.c
SRCS+= libusb10_io.c
.if defined(COMPAT_32BIT)
@ -142,6 +143,8 @@ MLINKS += libusb.3 libusb_handle_events_locked.3
MLINKS += libusb.3 libusb_get_next_timeout.3
MLINKS += libusb.3 libusb_set_pollfd_notifiers.3
MLINKS += libusb.3 libusb_get_pollfds.3
MLINKS += libusb.3 libusb_hotplug_register_callback.3
MLINKS += libusb.3 libusb_hotplug_deregister_callback.3
# LibUSB v0.1
MLINKS += libusb.3 usb_open.3

View File

@ -26,7 +26,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd June 17, 2016
.Dd June 22, 2016
.Dt LIBUSB 3
.Os
.Sh NAME
@ -642,6 +642,47 @@ that libusb uses as an event source.
Retrive a list of file descriptors that should be polled by your main loop as
libusb event sources.
Returns a NULL-terminated list on success or NULL on failure.
.Pp
.Ft int
.Fn 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 *handle"
This function registers a hotplug filter.
The
.Fa events
argument select which events makes the hotplug filter trigger.
Available event values are LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED and LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT.
One or more events must be specified.
The
.Fa vendor_id ,
.Fa product_id
and
.Fa dev_class
arguments can be set to LIBUSB_HOTPLUG_MATCH_ANY to match any value in the USB device descriptor.
Else the specified value is used for matching.
If the
.Fa flags
argument is set to LIBUSB_HOTPLUG_ENUMERATE, all currently attached and matching USB devices will be passed to the hotplug filter, given by the
.Fa cb_fn
argument.
Else the
.Fa flags
argument should be set to LIBUSB_HOTPLUG_NO_FLAGS.
This function returns 0 upon success or a LIBUSB_ERROR code on failure.
.Pp
.Ft int
.Fn libusb_hotplug_callback_fn "libusb_context *ctx" "libusb_device *device" "libusb_hotplug_event event" "void *user_data"
The hotplug filter function.
If this function returns non-zero, the filter is removed.
Else the filter is kept and can receive more events.
The
.Fa user_data
argument is the same as given when the filter was registered.
The
.Fa event
argument can be either of LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED or LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT.
.Pp
.Ft void
.Fn libusb_hotplug_deregister_callback "libusb_context *ctx" "libusb_hotplug_callback_handle handle"
This function unregisters a hotplug filter.
.Sh LIBUSB VERSION 0.1 COMPATIBILITY
The library is also compliant with LibUSB version 0.1.12.
.Pp

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@ -236,12 +236,25 @@ enum libusb_debug_level {
LIBUSB_DEBUG_TRANSFER=2,
};
#define LIBUSB_HOTPLUG_MATCH_ANY -1
typedef enum {
LIBUSB_HOTPLUG_NO_FLAGS = 0,
LIBUSB_HOTPLUG_ENUMERATE = 1 << 0,
} libusb_hotplug_flag;
typedef enum {
LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED = 1,
LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT = 2,
} libusb_hotplug_event;
/* libusb structures */
struct libusb_context;
struct libusb_device;
struct libusb_transfer;
struct libusb_device_handle;
struct libusb_hotplug_callback_handle;
struct libusb_pollfd {
int fd;
@ -263,6 +276,7 @@ typedef struct libusb_device_handle libusb_device_handle;
typedef struct libusb_pollfd libusb_pollfd;
typedef void (*libusb_pollfd_added_cb) (int fd, short events, void *user_data);
typedef void (*libusb_pollfd_removed_cb) (int fd, void *user_data);
typedef struct libusb_hotplug_callback_handle *libusb_hotplug_callback_handle;
typedef struct libusb_device_descriptor {
uint8_t bLength;
@ -539,6 +553,14 @@ int libusb_interrupt_transfer(libusb_device_handle * devh, uint8_t endpoint, uin
uint16_t libusb_cpu_to_le16(uint16_t x);
uint16_t libusb_le16_to_cpu(uint16_t x);
/* Hotplug support */
typedef int (*libusb_hotplug_callback_fn)(libusb_context *ctx,
libusb_device *device, libusb_hotplug_event event, void *user_data);
int 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 *handle);
void libusb_hotplug_deregister_callback(libusb_context *ctx, libusb_hotplug_callback_handle handle);
#if 0
{ /* indent fix */
#endif

View File

@ -134,24 +134,34 @@ libusb_init(libusb_context **context)
}
TAILQ_INIT(&ctx->pollfds);
TAILQ_INIT(&ctx->tr_done);
TAILQ_INIT(&ctx->hotplug_cbh);
TAILQ_INIT(&ctx->hotplug_devs);
if (pthread_mutex_init(&ctx->ctx_lock, NULL) != 0) {
free(ctx);
return (LIBUSB_ERROR_NO_MEM);
}
if (pthread_mutex_init(&ctx->hotplug_lock, NULL) != 0) {
pthread_mutex_destroy(&ctx->ctx_lock);
free(ctx);
return (LIBUSB_ERROR_NO_MEM);
}
if (pthread_condattr_init(&attr) != 0) {
pthread_mutex_destroy(&ctx->ctx_lock);
pthread_mutex_destroy(&ctx->hotplug_lock);
free(ctx);
return (LIBUSB_ERROR_NO_MEM);
}
if (pthread_condattr_setclock(&attr, CLOCK_MONOTONIC) != 0) {
pthread_mutex_destroy(&ctx->ctx_lock);
pthread_mutex_destroy(&ctx->hotplug_lock);
pthread_condattr_destroy(&attr);
free(ctx);
return (LIBUSB_ERROR_OTHER);
}
if (pthread_cond_init(&ctx->ctx_cond, &attr) != 0) {
pthread_mutex_destroy(&ctx->ctx_lock);
pthread_mutex_destroy(&ctx->hotplug_lock);
pthread_condattr_destroy(&attr);
free(ctx);
return (LIBUSB_ERROR_NO_MEM);
@ -159,10 +169,12 @@ libusb_init(libusb_context **context)
pthread_condattr_destroy(&attr);
ctx->ctx_handler = NO_THREAD;
ctx->hotplug_handler = NO_THREAD;
ret = pipe(ctx->ctrl_pipe);
if (ret < 0) {
pthread_mutex_destroy(&ctx->ctx_lock);
pthread_mutex_destroy(&ctx->hotplug_lock);
pthread_cond_destroy(&ctx->ctx_cond);
free(ctx);
return (LIBUSB_ERROR_OTHER);
@ -195,12 +207,27 @@ libusb_exit(libusb_context *ctx)
if (ctx == NULL)
return;
/* stop hotplug thread, if any */
if (ctx->hotplug_handler != NO_THREAD) {
pthread_t td;
void *ptr;
HOTPLUG_LOCK(ctx);
td = ctx->hotplug_handler;
ctx->hotplug_handler = NO_THREAD;
HOTPLUG_UNLOCK(ctx);
pthread_join(td, &ptr);
}
/* XXX cleanup devices */
libusb10_remove_pollfd(ctx, &ctx->ctx_poll);
close(ctx->ctrl_pipe[0]);
close(ctx->ctrl_pipe[1]);
pthread_mutex_destroy(&ctx->ctx_lock);
pthread_mutex_destroy(&ctx->hotplug_lock);
pthread_cond_destroy(&ctx->ctx_cond);
pthread_mutex_lock(&default_context_lock);

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@ -36,6 +36,8 @@
#define CTX_LOCK(ctx) pthread_mutex_lock(&(ctx)->ctx_lock)
#define CTX_TRYLOCK(ctx) pthread_mutex_trylock(&(ctx)->ctx_lock)
#define CTX_UNLOCK(ctx) pthread_mutex_unlock(&(ctx)->ctx_lock)
#define HOTPLUG_LOCK(ctx) pthread_mutex_lock(&(ctx)->hotplug_lock)
#define HOTPLUG_UNLOCK(ctx) pthread_mutex_unlock(&(ctx)->hotplug_lock)
#define DPRINTF(ctx, dbg, format, args...) do { \
if ((ctx)->debug == dbg) { \
@ -72,6 +74,16 @@ struct libusb_super_transfer {
#define LIBUSB_SUPER_XFER_ST_PEND 1
};
struct libusb_hotplug_callback_handle {
TAILQ_ENTRY(libusb_hotplug_callback_handle) entry;
int events;
int vendor;
int product;
int devclass;
libusb_hotplug_callback_fn fn;
void *user_data;
};
struct libusb_context {
int debug;
int debug_fixed;
@ -80,12 +92,16 @@ struct libusb_context {
int tr_done_gen;
pthread_mutex_t ctx_lock;
pthread_mutex_t hotplug_lock;
pthread_cond_t ctx_cond;
pthread_t hotplug_handler;
pthread_t ctx_handler;
#define NO_THREAD ((pthread_t)-1)
TAILQ_HEAD(, libusb_super_pollfd) pollfds;
TAILQ_HEAD(, libusb_super_transfer) tr_done;
TAILQ_HEAD(, libusb_hotplug_callback_handle) hotplug_cbh;
TAILQ_HEAD(, libusb_device) hotplug_devs;
struct libusb_super_pollfd ctx_poll;
@ -103,6 +119,8 @@ struct libusb_device {
struct libusb_context *ctx;
TAILQ_ENTRY(libusb_device) hotplug_entry;
TAILQ_HEAD(, libusb_super_transfer) tr_head;
struct libusb20_device *os_priv;

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@ -0,0 +1,237 @@
/* $FreeBSD$ */
/*-
* Copyright (c) 2016 Hans Petter Selasky. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef LIBUSB_GLOBAL_INCLUDE_FILE
#include LIBUSB_GLOBAL_INCLUDE_FILE
#else
#include <assert.h>
#include <errno.h>
#include <poll.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/queue.h>
#include <sys/endian.h>
#endif
#define libusb_device_handle libusb20_device
#include "libusb20.h"
#include "libusb20_desc.h"
#include "libusb20_int.h"
#include "libusb.h"
#include "libusb10.h"
static int
libusb_hotplug_equal(libusb_device *_adev, libusb_device *_bdev)
{
struct libusb20_device *adev = _adev->os_priv;
struct libusb20_device *bdev = _bdev->os_priv;
if (adev->bus_number != bdev->bus_number)
return (0);
if (adev->device_address != bdev->device_address)
return (0);
if (memcmp(&adev->ddesc, &bdev->ddesc, sizeof(adev->ddesc)))
return (0);
if (memcmp(&adev->session_data, &bdev->session_data, sizeof(adev->session_data)))
return (0);
return (1);
}
static int
libusb_hotplug_filter(libusb_context *ctx, libusb_hotplug_callback_handle pcbh,
libusb_device *dev, libusb_hotplug_event event)
{
if (!(pcbh->events & event))
return (0);
if (pcbh->vendor != LIBUSB_HOTPLUG_MATCH_ANY &&
pcbh->vendor != libusb20_dev_get_device_desc(dev->os_priv)->idVendor)
return (0);
if (pcbh->product != LIBUSB_HOTPLUG_MATCH_ANY &&
pcbh->product != libusb20_dev_get_device_desc(dev->os_priv)->idProduct)
return (0);
if (pcbh->devclass != LIBUSB_HOTPLUG_MATCH_ANY &&
pcbh->devclass != libusb20_dev_get_device_desc(dev->os_priv)->bDeviceClass)
return (0);
return (pcbh->fn(ctx, dev, event, pcbh->user_data));
}
static void *
libusb_hotplug_scan(void *arg)
{
TAILQ_HEAD(, libusb_device) hotplug_devs;
libusb_hotplug_callback_handle acbh;
libusb_hotplug_callback_handle bcbh;
libusb_context *ctx = arg;
libusb_device **ppdev;
libusb_device *temp;
libusb_device *adev;
libusb_device *bdev;
unsigned do_loop = 1;
ssize_t count;
ssize_t x;
while (do_loop) {
usleep(4000000);
HOTPLUG_LOCK(ctx);
TAILQ_INIT(&hotplug_devs);
if (ctx->hotplug_handler != NO_THREAD) {
count = libusb_get_device_list(ctx, &ppdev);
if (count < 0)
continue;
for (x = 0; x != count; x++) {
TAILQ_INSERT_TAIL(&hotplug_devs, ppdev[x],
hotplug_entry);
}
libusb_free_device_list(ppdev, 0);
} else {
do_loop = 0;
}
/* figure out which devices are gone */
TAILQ_FOREACH_SAFE(adev, &ctx->hotplug_devs, hotplug_entry, temp) {
TAILQ_FOREACH(bdev, &hotplug_devs, hotplug_entry) {
if (libusb_hotplug_equal(adev, bdev))
break;
}
if (bdev == NULL) {
TAILQ_REMOVE(&ctx->hotplug_devs, adev, hotplug_entry);
TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) {
if (libusb_hotplug_filter(ctx, acbh, adev,
LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT) == 0)
continue;
TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry);
free(acbh);
}
libusb_unref_device(adev);
}
}
/* figure out which devices are new */
TAILQ_FOREACH_SAFE(adev, &hotplug_devs, hotplug_entry, temp) {
TAILQ_FOREACH(bdev, &ctx->hotplug_devs, hotplug_entry) {
if (libusb_hotplug_equal(adev, bdev))
break;
}
if (bdev == NULL) {
TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry);
TAILQ_INSERT_TAIL(&ctx->hotplug_devs, adev, hotplug_entry);
TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) {
if (libusb_hotplug_filter(ctx, acbh, adev,
LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0)
continue;
TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry);
free(acbh);
}
}
}
HOTPLUG_UNLOCK(ctx);
/* unref remaining devices */
while ((adev = TAILQ_FIRST(&hotplug_devs)) != NULL) {
TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry);
libusb_unref_device(adev);
}
}
return (NULL);
}
int 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 *phandle)
{
libusb_hotplug_callback_handle handle;
struct libusb_device *adev;
ctx = GET_CONTEXT(ctx);
if (ctx == NULL || cb_fn == NULL || events == 0 ||
vendor_id < -1 || vendor_id > 0xffff ||
product_id < -1 || product_id > 0xffff ||
dev_class < -1 || dev_class > 0xff)
return (LIBUSB_ERROR_INVALID_PARAM);
handle = malloc(sizeof(*handle));
if (handle == NULL)
return (LIBUSB_ERROR_NO_MEM);
HOTPLUG_LOCK(ctx);
if (ctx->hotplug_handler == NO_THREAD) {
if (pthread_create(&ctx->hotplug_handler, NULL,
&libusb_hotplug_scan, ctx) != 0)
ctx->hotplug_handler = NO_THREAD;
}
handle->events = events;
handle->vendor = vendor_id;
handle->product = product_id;
handle->devclass = dev_class;
handle->fn = cb_fn;
handle->user_data = user_data;
if (flags & LIBUSB_HOTPLUG_ENUMERATE) {
TAILQ_FOREACH(adev, &ctx->hotplug_devs, hotplug_entry) {
if (libusb_hotplug_filter(ctx, handle, adev,
LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0)
continue;
free(handle);
handle = NULL;
break;
}
}
if (handle != NULL)
TAILQ_INSERT_TAIL(&ctx->hotplug_cbh, handle, entry);
HOTPLUG_UNLOCK(ctx);
if (phandle != NULL)
*phandle = handle;
return (LIBUSB_SUCCESS);
}
void libusb_hotplug_deregister_callback(libusb_context *ctx,
libusb_hotplug_callback_handle handle)
{
ctx = GET_CONTEXT(ctx);
if (ctx == NULL || handle == NULL)
return;
HOTPLUG_LOCK(ctx);
TAILQ_REMOVE(&ctx->hotplug_cbh, handle, entry);
HOTPLUG_UNLOCK(ctx);
free(handle);
}