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
23#include "usbip_common.h"
24#include "stub.h"
25
26#define DRIVER_AUTHOR "Takahiro Hirofuchi"
27#define DRIVER_DESC "USB/IP Host Driver"
28
29struct kmem_cache *stub_priv_cache;
30/*
31 * busid_tables defines matching busids that usbip can grab. A user can change
32 * dynamically what device is locally used and what device is exported to a
33 * remote host.
34 */
35#define MAX_BUSID 16
36static struct bus_id_priv busid_table[MAX_BUSID];
37static spinlock_t busid_table_lock;
38
39static void init_busid_table(void)
40{
41	int i;
42
43	memset(busid_table, 0, sizeof(busid_table));
44	for (i = 0; i < MAX_BUSID; i++)
45		busid_table[i].status = STUB_BUSID_OTHER;
46
47	spin_lock_init(&busid_table_lock);
48}
49
50/*
51 * Find the index of the busid by name.
52 * Must be called with busid_table_lock held.
53 */
54static int get_busid_idx(const char *busid)
55{
56	int i;
57	int idx = -1;
58
59	for (i = 0; i < MAX_BUSID; i++)
60		if (busid_table[i].name[0])
61			if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
62				idx = i;
63				break;
64			}
65	return idx;
66}
67
68struct bus_id_priv *get_busid_priv(const char *busid)
69{
70	int idx;
71	struct bus_id_priv *bid = NULL;
72
73	spin_lock(&busid_table_lock);
74	idx = get_busid_idx(busid);
75	if (idx >= 0)
76		bid = &(busid_table[idx]);
77	spin_unlock(&busid_table_lock);
78
79	return bid;
80}
81
82static int add_match_busid(char *busid)
83{
84	int i;
85	int ret = -1;
86
87	spin_lock(&busid_table_lock);
88	/* already registered? */
89	if (get_busid_idx(busid) >= 0) {
90		ret = 0;
91		goto out;
92	}
93
94	for (i = 0; i < MAX_BUSID; i++)
95		if (!busid_table[i].name[0]) {
96			strncpy(busid_table[i].name, busid, BUSID_SIZE);
97			if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
98			    (busid_table[i].status != STUB_BUSID_REMOV))
99				busid_table[i].status = STUB_BUSID_ADDED;
100			ret = 0;
101			break;
102		}
103
104out:
105	spin_unlock(&busid_table_lock);
106
107	return ret;
108}
109
110int del_match_busid(char *busid)
111{
112	int idx;
113	int ret = -1;
114
115	spin_lock(&busid_table_lock);
116	idx = get_busid_idx(busid);
117	if (idx < 0)
118		goto out;
119
120	/* found */
121	ret = 0;
122
123	if (busid_table[idx].status == STUB_BUSID_OTHER)
124		memset(busid_table[idx].name, 0, BUSID_SIZE);
125
126	if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
127	    (busid_table[idx].status != STUB_BUSID_ADDED))
128		busid_table[idx].status = STUB_BUSID_REMOV;
129
130out:
131	spin_unlock(&busid_table_lock);
132
133	return ret;
134}
135
136static ssize_t show_match_busid(struct device_driver *drv, char *buf)
137{
138	int i;
139	char *out = buf;
140
141	spin_lock(&busid_table_lock);
142	for (i = 0; i < MAX_BUSID; i++)
143		if (busid_table[i].name[0])
144			out += sprintf(out, "%s ", busid_table[i].name);
145	spin_unlock(&busid_table_lock);
146	out += sprintf(out, "\n");
147
148	return out - buf;
149}
150
151static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
152				 size_t count)
153{
154	int len;
155	char busid[BUSID_SIZE];
156
157	if (count < 5)
158		return -EINVAL;
159
160	/* strnlen() does not include \0 */
161	len = strnlen(buf + 4, BUSID_SIZE);
162
163	/* busid needs to include \0 termination */
164	if (!(len < BUSID_SIZE))
165		return -EINVAL;
166
167	strncpy(busid, buf + 4, BUSID_SIZE);
168
169	if (!strncmp(buf, "add ", 4)) {
170		if (add_match_busid(busid) < 0) {
171			return -ENOMEM;
172		} else {
173			pr_debug("add busid %s\n", busid);
174			return count;
175		}
176	} else if (!strncmp(buf, "del ", 4)) {
177		if (del_match_busid(busid) < 0) {
178			return -ENODEV;
179		} else {
180			pr_debug("del busid %s\n", busid);
181			return count;
182		}
183	} else {
184		return -EINVAL;
185	}
186}
187static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
188		   store_match_busid);
189
190static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
191{
192	struct stub_priv *priv, *tmp;
193
194	list_for_each_entry_safe(priv, tmp, listhead, list) {
195		list_del(&priv->list);
196		return priv;
197	}
198
199	return NULL;
200}
201
202static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
203{
204	unsigned long flags;
205	struct stub_priv *priv;
206
207	spin_lock_irqsave(&sdev->priv_lock, flags);
208
209	priv = stub_priv_pop_from_listhead(&sdev->priv_init);
210	if (priv)
211		goto done;
212
213	priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
214	if (priv)
215		goto done;
216
217	priv = stub_priv_pop_from_listhead(&sdev->priv_free);
218
219done:
220	spin_unlock_irqrestore(&sdev->priv_lock, flags);
221
222	return priv;
223}
224
225void stub_device_cleanup_urbs(struct stub_device *sdev)
226{
227	struct stub_priv *priv;
228	struct urb *urb;
229
230	dev_dbg(&sdev->udev->dev, "free sdev %p\n", sdev);
231
232	while ((priv = stub_priv_pop(sdev))) {
233		urb = priv->urb;
234		dev_dbg(&sdev->udev->dev, "free urb %p\n", urb);
235		usb_kill_urb(urb);
236
237		kmem_cache_free(stub_priv_cache, priv);
238
239		kfree(urb->transfer_buffer);
240		kfree(urb->setup_packet);
241		usb_free_urb(urb);
242	}
243}
244
245static int __init usbip_host_init(void)
246{
247	int ret;
248
249	init_busid_table();
250
251	stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
252	if (!stub_priv_cache) {
253		pr_err("kmem_cache_create failed\n");
254		return -ENOMEM;
255	}
256
257	ret = usb_register(&stub_driver);
258	if (ret < 0) {
259		pr_err("usb_register failed %d\n", ret);
260		goto err_usb_register;
261	}
262
263	ret = driver_create_file(&stub_driver.drvwrap.driver,
264				 &driver_attr_match_busid);
265	if (ret < 0) {
266		pr_err("driver_create_file failed\n");
267		goto err_create_file;
268	}
269
270	pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
271	return ret;
272
273err_create_file:
274	usb_deregister(&stub_driver);
275err_usb_register:
276	kmem_cache_destroy(stub_priv_cache);
277	return ret;
278}
279
280static void __exit usbip_host_exit(void)
281{
282	driver_remove_file(&stub_driver.drvwrap.driver,
283			   &driver_attr_match_busid);
284
285	/*
286	 * deregister() calls stub_disconnect() for all devices. Device
287	 * specific data is cleared in stub_disconnect().
288	 */
289	usb_deregister(&stub_driver);
290
291	kmem_cache_destroy(stub_priv_cache);
292}
293
294module_init(usbip_host_init);
295module_exit(usbip_host_exit);
296
297MODULE_AUTHOR(DRIVER_AUTHOR);
298MODULE_DESCRIPTION(DRIVER_DESC);
299MODULE_LICENSE("GPL");
300MODULE_VERSION(USBIP_VERSION);
301