summaryrefslogtreecommitdiffstats
path: root/drivers/usb/usbip/stub_main.c
blob: 44ab43fc4fcc71c8f7732e5c74120ae278b0b89f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include <linux/string.h>
#include <linux/module.h>
#include <linux/device.h>

#include "usbip_common.h"
#include "stub.h"

#define DRIVER_AUTHOR "Takahiro Hirofuchi"
#define DRIVER_DESC "USB/IP Host Driver"

struct kmem_cache *stub_priv_cache;
/*
 * busid_tables defines matching busids that usbip can grab. A user can change
 * dynamically what device is locally used and what device is exported to a
 * remote host.
 */
#define MAX_BUSID 16
static struct bus_id_priv busid_table[MAX_BUSID];
static spinlock_t busid_table_lock;

static void init_busid_table(void)
{
	/*
	 * This also sets the bus_table[i].status to
	 * STUB_BUSID_OTHER, which is 0.
	 */
	memset(busid_table, 0, sizeof(busid_table));

	spin_lock_init(&busid_table_lock);
}

/*
 * Find the index of the busid by name.
 * Must be called with busid_table_lock held.
 */
static int get_busid_idx(const char *busid)
{
	int i;
	int idx = -1;

	for (i = 0; i < MAX_BUSID; i++)
		if (busid_table[i].name[0])
			if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
				idx = i;
				break;
			}
	return idx;
}

struct bus_id_priv *get_busid_priv(const char *busid)
{
	int idx;
	struct bus_id_priv *bid = NULL;

	spin_lock(&busid_table_lock);
	idx = get_busid_idx(busid);
	if (idx >= 0)
		bid = &(busid_table[idx]);
	spin_unlock(&busid_table_lock);

	return bid;
}

static int add_match_busid(char *busid)
{
	int i;
	int ret = -1;

	spin_lock(&busid_table_lock);
	/* already registered? */
	if (get_busid_idx(busid) >= 0) {
		ret = 0;
		goto out;
	}

	for (i = 0; i < MAX_BUSID; i++)
		if (!busid_table[i].name[0]) {
			strlcpy(busid_table[i].name, busid, BUSID_SIZE);
			if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
			    (busid_table[i].status != STUB_BUSID_REMOV))
				busid_table[i].status = STUB_BUSID_ADDED;
			ret = 0;
			break;
		}

out:
	spin_unlock(&busid_table_lock);

	return ret;
}

int del_match_busid(char *busid)
{
	int idx;
	int ret = -1;

	spin_lock(&busid_table_lock);
	idx = get_busid_idx(busid);
	if (idx < 0)
		goto out;

	/* found */
	ret = 0;

	if (busid_table[idx].status == STUB_BUSID_OTHER)
		memset(busid_table[idx].name, 0, BUSID_SIZE);

	if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
	    (busid_table[idx].status != STUB_BUSID_ADDED))
		busid_table[idx].status = STUB_BUSID_REMOV;

out:
	spin_unlock(&busid_table_lock);

	return ret;
}

static ssize_t show_match_busid(struct device_driver *drv, char *buf)
{
	int i;
	char *out = buf;

	spin_lock(&busid_table_lock);
	for (i = 0; i < MAX_BUSID; i++)
		if (busid_table[i].name[0])
			out += sprintf(out, "%s ", busid_table[i].name);
	spin_unlock(&busid_table_lock);
	out += sprintf(out, "\n");

	return out - buf;
}

static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
				 size_t count)
{
	int len;
	char busid[BUSID_SIZE];

	if (count < 5)
		return -EINVAL;

	/* busid needs to include \0 termination */
	len = strlcpy(busid, buf + 4, BUSID_SIZE);
	if (sizeof(busid) <= len)
		return -EINVAL;

	if (!strncmp(buf, "add ", 4)) {
		if (add_match_busid(busid) < 0)
			return -ENOMEM;

		pr_debug("add busid %s\n", busid);
		return count;
	}

	if (!strncmp(buf, "del ", 4)) {
		if (del_match_busid(busid) < 0)
			return -ENODEV;

		pr_debug("del busid %s\n", busid);
		return count;
	}

	return -EINVAL;
}
static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
		   store_match_busid);

static ssize_t rebind_store(struct device_driver *dev, const char *buf,
				 size_t count)
{
	int ret;
	int len;
	struct bus_id_priv *bid;

	/* buf length should be less that BUSID_SIZE */
	len = strnlen(buf, BUSID_SIZE);

	if (!(len < BUSID_SIZE))
		return -EINVAL;

	bid = get_busid_priv(buf);
	if (!bid)
		return -ENODEV;

	ret = device_attach(&bid->udev->dev);
	if (ret < 0) {
		dev_err(&bid->udev->dev, "rebind failed\n");
		return ret;
	}

	return count;
}

static DRIVER_ATTR_WO(rebind);

static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
{
	struct stub_priv *priv, *tmp;

	list_for_each_entry_safe(priv, tmp, listhead, list) {
		list_del(&priv->list);
		return priv;
	}

	return NULL;
}

static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
{
	unsigned long flags;
	struct stub_priv *priv;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	priv = stub_priv_pop_from_listhead(&sdev->priv_init);
	if (priv)
		goto done;

	priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
	if (priv)
		goto done;

	priv = stub_priv_pop_from_listhead(&sdev->priv_free);

done:
	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return priv;
}

void stub_device_cleanup_urbs(struct stub_device *sdev)
{
	struct stub_priv *priv;
	struct urb *urb;

	dev_dbg(&sdev->udev->dev, "free sdev %p\n", sdev);

	while ((priv = stub_priv_pop(sdev))) {
		urb = priv->urb;
		dev_dbg(&sdev->udev->dev, "free urb %p\n", urb);
		usb_kill_urb(urb);

		kmem_cache_free(stub_priv_cache, priv);

		kfree(urb->transfer_buffer);
		kfree(urb->setup_packet);
		usb_free_urb(urb);
	}
}

static int __init usbip_host_init(void)
{
	int ret;

	init_busid_table();

	stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
	if (!stub_priv_cache) {
		pr_err("kmem_cache_create failed\n");
		return -ENOMEM;
	}

	ret = usb_register_device_driver(&stub_driver, THIS_MODULE);
	if (ret) {
		pr_err("usb_register failed %d\n", ret);
		goto err_usb_register;
	}

	ret = driver_create_file(&stub_driver.drvwrap.driver,
				 &driver_attr_match_busid);
	if (ret) {
		pr_err("driver_create_file failed\n");
		goto err_create_file;
	}

	ret = driver_create_file(&stub_driver.drvwrap.driver,
				 &driver_attr_rebind);
	if (ret) {
		pr_err("driver_create_file failed\n");
		goto err_create_file;
	}

	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
	return ret;

err_create_file:
	usb_deregister_device_driver(&stub_driver);
err_usb_register:
	kmem_cache_destroy(stub_priv_cache);
	return ret;
}

static void __exit usbip_host_exit(void)
{
	driver_remove_file(&stub_driver.drvwrap.driver,
			   &driver_attr_match_busid);

	driver_remove_file(&stub_driver.drvwrap.driver,
			   &driver_attr_rebind);

	/*
	 * deregister() calls stub_disconnect() for all devices. Device
	 * specific data is cleared in stub_disconnect().
	 */
	usb_deregister_device_driver(&stub_driver);

	kmem_cache_destroy(stub_priv_cache);
}

module_init(usbip_host_init);
module_exit(usbip_host_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(USBIP_VERSION);