1/*
  2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
  3 *
  4 * This is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License as published by
  6 * the Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 *
  9 * This is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12 * GNU General Public License for more details.
 13 *
 14 * You should have received a copy of the GNU General Public License
 15 * along with this program; if not, write to the Free Software
 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 17 * USA.
 18 */
 19
 20#include <linux/string.h>
 21#include <linux/module.h>
 22#include <linux/device.h>
 23
 24#include "usbip_common.h"
 25#include "stub.h"
 26
 27#define DRIVER_AUTHOR "Takahiro Hirofuchi"
 28#define DRIVER_DESC "USB/IP Host Driver"
 29
 30struct kmem_cache *stub_priv_cache;
 31/*
 32 * busid_tables defines matching busids that usbip can grab. A user can change
 33 * dynamically what device is locally used and what device is exported to a
 34 * remote host.
 35 */
 36#define MAX_BUSID 16
 37static struct bus_id_priv busid_table[MAX_BUSID];
 38static spinlock_t busid_table_lock;
 39
 40static void init_busid_table(void)
 41{
 42	/*
 43	 * This also sets the bus_table[i].status to
 44	 * STUB_BUSID_OTHER, which is 0.
 45	 */
 46	memset(busid_table, 0, sizeof(busid_table));
 47
 48	spin_lock_init(&busid_table_lock);
 49}
 50
 51/*
 52 * Find the index of the busid by name.
 53 * Must be called with busid_table_lock held.
 54 */
 55static int get_busid_idx(const char *busid)
 56{
 57	int i;
 58	int idx = -1;
 59
 60	for (i = 0; i < MAX_BUSID; i++)
 61		if (busid_table[i].name[0])
 62			if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
 63				idx = i;
 64				break;
 65			}
 66	return idx;
 67}
 68
 69struct bus_id_priv *get_busid_priv(const char *busid)
 70{
 71	int idx;
 72	struct bus_id_priv *bid = NULL;
 73
 74	spin_lock(&busid_table_lock);
 75	idx = get_busid_idx(busid);
 76	if (idx >= 0)
 77		bid = &(busid_table[idx]);
 78	spin_unlock(&busid_table_lock);
 79
 80	return bid;
 81}
 82
 83static int add_match_busid(char *busid)
 84{
 85	int i;
 86	int ret = -1;
 87
 88	spin_lock(&busid_table_lock);
 89	/* already registered? */
 90	if (get_busid_idx(busid) >= 0) {
 91		ret = 0;
 92		goto out;
 93	}
 94
 95	for (i = 0; i < MAX_BUSID; i++)
 96		if (!busid_table[i].name[0]) {
 97			strlcpy(busid_table[i].name, busid, BUSID_SIZE);
 98			if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
 99			    (busid_table[i].status != STUB_BUSID_REMOV))
100				busid_table[i].status = STUB_BUSID_ADDED;
101			ret = 0;
102			break;
103		}
104
105out:
106	spin_unlock(&busid_table_lock);
107
108	return ret;
109}
110
111int del_match_busid(char *busid)
112{
113	int idx;
114	int ret = -1;
115
116	spin_lock(&busid_table_lock);
117	idx = get_busid_idx(busid);
118	if (idx < 0)
119		goto out;
120
121	/* found */
122	ret = 0;
123
124	if (busid_table[idx].status == STUB_BUSID_OTHER)
125		memset(busid_table[idx].name, 0, BUSID_SIZE);
126
127	if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
128	    (busid_table[idx].status != STUB_BUSID_ADDED))
129		busid_table[idx].status = STUB_BUSID_REMOV;
130
131out:
132	spin_unlock(&busid_table_lock);
133
134	return ret;
135}
136
137static ssize_t show_match_busid(struct device_driver *drv, char *buf)
138{
139	int i;
140	char *out = buf;
141
142	spin_lock(&busid_table_lock);
143	for (i = 0; i < MAX_BUSID; i++)
144		if (busid_table[i].name[0])
145			out += sprintf(out, "%s ", busid_table[i].name);
146	spin_unlock(&busid_table_lock);
147	out += sprintf(out, "\n");
148
149	return out - buf;
150}
151
152static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
153				 size_t count)
154{
155	int len;
156	char busid[BUSID_SIZE];
157
158	if (count < 5)
159		return -EINVAL;
160
161	/* busid needs to include \0 termination */
162	len = strlcpy(busid, buf + 4, BUSID_SIZE);
163	if (sizeof(busid) <= len)
164		return -EINVAL;
165
166	if (!strncmp(buf, "add ", 4)) {
167		if (add_match_busid(busid) < 0)
168			return -ENOMEM;
169
170		pr_debug("add busid %s\n", busid);
171		return count;
172	}
173
174	if (!strncmp(buf, "del ", 4)) {
175		if (del_match_busid(busid) < 0)
176			return -ENODEV;
177
178		pr_debug("del busid %s\n", busid);
179		return count;
180	}
181
182	return -EINVAL;
183}
184static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
185		   store_match_busid);
186
187static ssize_t rebind_store(struct device_driver *dev, const char *buf,
188				 size_t count)
189{
190	int ret;
191	int len;
192	struct bus_id_priv *bid;
193
194	/* buf length should be less that BUSID_SIZE */
195	len = strnlen(buf, BUSID_SIZE);
196
197	if (!(len < BUSID_SIZE))
198		return -EINVAL;
199
200	bid = get_busid_priv(buf);
201	if (!bid)
202		return -ENODEV;
203
204	ret = device_attach(&bid->udev->dev);
205	if (ret < 0) {
206		dev_err(&bid->udev->dev, "rebind failed\n");
207		return ret;
208	}
209
210	return count;
211}
212
213static DRIVER_ATTR_WO(rebind);
214
215static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
216{
217	struct stub_priv *priv, *tmp;
218
219	list_for_each_entry_safe(priv, tmp, listhead, list) {
220		list_del(&priv->list);
221		return priv;
222	}
223
224	return NULL;
225}
226
227static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
228{
229	unsigned long flags;
230	struct stub_priv *priv;
231
232	spin_lock_irqsave(&sdev->priv_lock, flags);
233
234	priv = stub_priv_pop_from_listhead(&sdev->priv_init);
235	if (priv)
236		goto done;
237
238	priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
239	if (priv)
240		goto done;
241
242	priv = stub_priv_pop_from_listhead(&sdev->priv_free);
243
244done:
245	spin_unlock_irqrestore(&sdev->priv_lock, flags);
246
247	return priv;
248}
249
250void stub_device_cleanup_urbs(struct stub_device *sdev)
251{
252	struct stub_priv *priv;
253	struct urb *urb;
254
255	dev_dbg(&sdev->udev->dev, "free sdev %p\n", sdev);
256
257	while ((priv = stub_priv_pop(sdev))) {
258		urb = priv->urb;
259		dev_dbg(&sdev->udev->dev, "free urb %p\n", urb);
260		usb_kill_urb(urb);
261
262		kmem_cache_free(stub_priv_cache, priv);
263
264		kfree(urb->transfer_buffer);
265		kfree(urb->setup_packet);
266		usb_free_urb(urb);
267	}
268}
269
270static int __init usbip_host_init(void)
271{
272	int ret;
273
274	init_busid_table();
275
276	stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
277	if (!stub_priv_cache) {
278		pr_err("kmem_cache_create failed\n");
279		return -ENOMEM;
280	}
281
282	ret = usb_register_device_driver(&stub_driver, THIS_MODULE);
283	if (ret) {
284		pr_err("usb_register failed %d\n", ret);
285		goto err_usb_register;
286	}
287
288	ret = driver_create_file(&stub_driver.drvwrap.driver,
289				 &driver_attr_match_busid);
290	if (ret) {
291		pr_err("driver_create_file failed\n");
292		goto err_create_file;
293	}
294
295	ret = driver_create_file(&stub_driver.drvwrap.driver,
296				 &driver_attr_rebind);
297	if (ret) {
298		pr_err("driver_create_file failed\n");
299		goto err_create_file;
300	}
301
302	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
303	return ret;
304
305err_create_file:
306	usb_deregister_device_driver(&stub_driver);
307err_usb_register:
308	kmem_cache_destroy(stub_priv_cache);
309	return ret;
310}
311
312static void __exit usbip_host_exit(void)
313{
314	driver_remove_file(&stub_driver.drvwrap.driver,
315			   &driver_attr_match_busid);
316
317	driver_remove_file(&stub_driver.drvwrap.driver,
318			   &driver_attr_rebind);
319
320	/*
321	 * deregister() calls stub_disconnect() for all devices. Device
322	 * specific data is cleared in stub_disconnect().
323	 */
324	usb_deregister_device_driver(&stub_driver);
325
326	kmem_cache_destroy(stub_priv_cache);
327}
328
329module_init(usbip_host_init);
330module_exit(usbip_host_exit);
331
332MODULE_AUTHOR(DRIVER_AUTHOR);
333MODULE_DESCRIPTION(DRIVER_DESC);
334MODULE_LICENSE("GPL");
335MODULE_VERSION(USBIP_VERSION);