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

6 files changed, 349 insertions, 1 deletions

diff --git a/lib/libusb/Makefile b/lib/libusb/Makefile
index bdeaef6..adc5179 100644
--- a/lib/libusb/Makefile
+++ b/lib/libusb/Makefile
@@ -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
diff --git a/lib/libusb/libusb.3 b/lib/libusb/libusb.3
index 0ccb95c..4950a25 100644
--- a/lib/libusb/libusb.3
+++ b/lib/libusb/libusb.3
@@ -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
diff --git a/lib/libusb/libusb.h b/lib/libusb/libusb.h
index d446830..1738301 100644
--- a/lib/libusb/libusb.h
+++ b/lib/libusb/libusb.h
@@ -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
diff --git a/lib/libusb/libusb10.c b/lib/libusb/libusb10.c
index 7b336c9..c6eb771 100644
--- a/lib/libusb/libusb10.c
+++ b/lib/libusb/libusb10.c
@@ -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);
diff --git a/lib/libusb/libusb10.h b/lib/libusb/libusb10.h
index f1e5460..d2df6e0 100644
--- a/lib/libusb/libusb10.h
+++ b/lib/libusb/libusb10.h
@@ -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;
diff --git a/lib/libusb/libusb10_hotplug.c b/lib/libusb/libusb10_hotplug.c
new file mode 100644
index 0000000..162cf2b
--- /dev/null
+++ b/lib/libusb/libusb10_hotplug.c
@@ -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);
+}