xref: /freebsd/lib/libusb/libusb10_hotplug.c (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /* $FreeBSD$ */
2 /*-
3  * Copyright (c) 2016-2019 Hans Petter Selasky. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #ifdef LIBUSB_GLOBAL_INCLUDE_FILE
28 #include LIBUSB_GLOBAL_INCLUDE_FILE
29 #else
30 #include <assert.h>
31 #include <errno.h>
32 #include <poll.h>
33 #include <pthread.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <time.h>
39 #include <sys/fcntl.h>
40 #include <sys/ioctl.h>
41 #include <sys/queue.h>
42 #include <sys/endian.h>
43 #endif
44 
45 #define	libusb_device_handle libusb20_device
46 
47 #include "libusb20.h"
48 #include "libusb20_desc.h"
49 #include "libusb20_int.h"
50 #include "libusb.h"
51 #include "libusb10.h"
52 
53 static int
54 libusb_hotplug_equal(libusb_device *_adev, libusb_device *_bdev)
55 {
56 	struct libusb20_device *adev = _adev->os_priv;
57 	struct libusb20_device *bdev = _bdev->os_priv;
58 
59 	if (adev->bus_number != bdev->bus_number)
60 		return (0);
61 	if (adev->device_address != bdev->device_address)
62 		return (0);
63 	if (memcmp(&adev->ddesc, &bdev->ddesc, sizeof(adev->ddesc)))
64 		return (0);
65 	if (memcmp(&adev->session_data, &bdev->session_data, sizeof(adev->session_data)))
66 		return (0);
67 	return (1);
68 }
69 
70 static int
71 libusb_hotplug_filter(libusb_context *ctx, libusb_hotplug_callback_handle pcbh,
72     libusb_device *dev, libusb_hotplug_event event)
73 {
74 	if (!(pcbh->events & event))
75 		return (0);
76 	if (pcbh->vendor != LIBUSB_HOTPLUG_MATCH_ANY &&
77 	    pcbh->vendor != libusb20_dev_get_device_desc(dev->os_priv)->idVendor)
78 		return (0);
79 	if (pcbh->product != LIBUSB_HOTPLUG_MATCH_ANY &&
80 	    pcbh->product != libusb20_dev_get_device_desc(dev->os_priv)->idProduct)
81 		return (0);
82 	if (pcbh->devclass != LIBUSB_HOTPLUG_MATCH_ANY &&
83 	    pcbh->devclass != libusb20_dev_get_device_desc(dev->os_priv)->bDeviceClass)
84 		return (0);
85 	return (pcbh->fn(ctx, dev, event, pcbh->user_data));
86 }
87 
88 static int
89 libusb_hotplug_enumerate(libusb_context *ctx, struct libusb_device_head *phead)
90 {
91 	libusb_device **ppdev;
92 	ssize_t count;
93 	ssize_t x;
94 
95 	count = libusb_get_device_list(ctx, &ppdev);
96 	if (count < 0)
97 		return (-1);
98 
99 	for (x = 0; x != count; x++)
100 		TAILQ_INSERT_TAIL(phead, ppdev[x], hotplug_entry);
101 
102 	libusb_free_device_list(ppdev, 0);
103 	return (0);
104 }
105 
106 static void *
107 libusb_hotplug_scan(void *arg)
108 {
109 	struct libusb_device_head hotplug_devs;
110 	libusb_hotplug_callback_handle acbh;
111 	libusb_hotplug_callback_handle bcbh;
112 	libusb_context *ctx = arg;
113 	libusb_device *temp;
114 	libusb_device *adev;
115 	libusb_device *bdev;
116 	unsigned do_loop = 1;
117 
118 	while (do_loop) {
119 		usleep(4000000);
120 
121 		HOTPLUG_LOCK(ctx);
122 
123 		TAILQ_INIT(&hotplug_devs);
124 
125 		if (ctx->hotplug_handler != NO_THREAD) {
126 			if (libusb_hotplug_enumerate(ctx, &hotplug_devs) < 0) {
127 				HOTPLUG_UNLOCK(ctx);
128 				continue;
129 			}
130 		} else {
131 			do_loop = 0;
132 		}
133 
134 		/* figure out which devices are gone */
135 		TAILQ_FOREACH_SAFE(adev, &ctx->hotplug_devs, hotplug_entry, temp) {
136 			TAILQ_FOREACH(bdev, &hotplug_devs, hotplug_entry) {
137 				if (libusb_hotplug_equal(adev, bdev))
138 					break;
139 			}
140 			if (bdev == NULL) {
141 				TAILQ_REMOVE(&ctx->hotplug_devs, adev, hotplug_entry);
142 				TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) {
143 					if (libusb_hotplug_filter(ctx, acbh, adev,
144 					    LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT) == 0)
145 						continue;
146 					TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry);
147 					free(acbh);
148 				}
149 				libusb_unref_device(adev);
150 			}
151 		}
152 
153 		/* figure out which devices are new */
154 		TAILQ_FOREACH_SAFE(adev, &hotplug_devs, hotplug_entry, temp) {
155 			TAILQ_FOREACH(bdev, &ctx->hotplug_devs, hotplug_entry) {
156 				if (libusb_hotplug_equal(adev, bdev))
157 					break;
158 			}
159 			if (bdev == NULL) {
160 				TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry);
161 				TAILQ_INSERT_TAIL(&ctx->hotplug_devs, adev, hotplug_entry);
162 				TAILQ_FOREACH_SAFE(acbh, &ctx->hotplug_cbh, entry, bcbh) {
163 					if (libusb_hotplug_filter(ctx, acbh, adev,
164 					    LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0)
165 						continue;
166 					TAILQ_REMOVE(&ctx->hotplug_cbh, acbh, entry);
167 					free(acbh);
168 				}
169 			}
170 		}
171 		HOTPLUG_UNLOCK(ctx);
172 
173 		/* unref remaining devices */
174 		while ((adev = TAILQ_FIRST(&hotplug_devs)) != NULL) {
175 			TAILQ_REMOVE(&hotplug_devs, adev, hotplug_entry);
176 			libusb_unref_device(adev);
177 		}
178 	}
179 	return (NULL);
180 }
181 
182 int libusb_hotplug_register_callback(libusb_context *ctx,
183     libusb_hotplug_event events, libusb_hotplug_flag flags,
184     int vendor_id, int product_id, int dev_class,
185     libusb_hotplug_callback_fn cb_fn, void *user_data,
186     libusb_hotplug_callback_handle *phandle)
187 {
188 	libusb_hotplug_callback_handle handle;
189 	struct libusb_device *adev;
190 
191 	ctx = GET_CONTEXT(ctx);
192 
193 	if (ctx == NULL || cb_fn == NULL || events == 0 ||
194 	    vendor_id < -1 || vendor_id > 0xffff ||
195 	    product_id < -1 || product_id > 0xffff ||
196 	    dev_class < -1 || dev_class > 0xff)
197 		return (LIBUSB_ERROR_INVALID_PARAM);
198 
199 	handle = malloc(sizeof(*handle));
200 	if (handle == NULL)
201 		return (LIBUSB_ERROR_NO_MEM);
202 
203 	HOTPLUG_LOCK(ctx);
204 	if (ctx->hotplug_handler == NO_THREAD) {
205 	  	libusb_hotplug_enumerate(ctx, &ctx->hotplug_devs);
206 
207 		if (pthread_create(&ctx->hotplug_handler, NULL,
208 		    &libusb_hotplug_scan, ctx) != 0)
209 			ctx->hotplug_handler = NO_THREAD;
210 	}
211 	handle->events = events;
212 	handle->vendor = vendor_id;
213 	handle->product = product_id;
214 	handle->devclass = dev_class;
215 	handle->fn = cb_fn;
216 	handle->user_data = user_data;
217 
218 	if (flags & LIBUSB_HOTPLUG_ENUMERATE) {
219 		TAILQ_FOREACH(adev, &ctx->hotplug_devs, hotplug_entry) {
220 			if (libusb_hotplug_filter(ctx, handle, adev,
221 			    LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED) == 0)
222 				continue;
223 			free(handle);
224 			handle = NULL;
225 			break;
226 		}
227 	}
228 	if (handle != NULL)
229 		TAILQ_INSERT_TAIL(&ctx->hotplug_cbh, handle, entry);
230 	HOTPLUG_UNLOCK(ctx);
231 
232 	if (phandle != NULL)
233 		*phandle = handle;
234 	return (LIBUSB_SUCCESS);
235 }
236 
237 void libusb_hotplug_deregister_callback(libusb_context *ctx,
238     libusb_hotplug_callback_handle handle)
239 {
240   	ctx = GET_CONTEXT(ctx);
241 
242 	if (ctx == NULL || handle == NULL)
243 		return;
244 
245 	HOTPLUG_LOCK(ctx);
246 	TAILQ_REMOVE(&ctx->hotplug_cbh, handle, entry);
247 	HOTPLUG_UNLOCK(ctx);
248 
249 	free(handle);
250 }
251