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 
29 struct 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
36 static struct bus_id_priv busid_table[MAX_BUSID];
37 static spinlock_t busid_table_lock;
38 
init_busid_table(void)39 static 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  */
get_busid_idx(const char * busid)54 static 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 
get_busid_priv(const char * busid)68 struct 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 
add_match_busid(char * busid)82 static 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 
104 out:
105 	spin_unlock(&busid_table_lock);
106 
107 	return ret;
108 }
109 
del_match_busid(char * busid)110 int 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 
130 out:
131 	spin_unlock(&busid_table_lock);
132 
133 	return ret;
134 }
135 
show_match_busid(struct device_driver * drv,char * buf)136 static 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 
store_match_busid(struct device_driver * dev,const char * buf,size_t count)151 static 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 }
187 static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
188 		   store_match_busid);
189 
stub_priv_pop_from_listhead(struct list_head * listhead)190 static 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 
stub_priv_pop(struct stub_device * sdev)202 static 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 
219 done:
220 	spin_unlock_irqrestore(&sdev->priv_lock, flags);
221 
222 	return priv;
223 }
224 
stub_device_cleanup_urbs(struct stub_device * sdev)225 void 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 
usbip_host_init(void)245 static 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 
273 err_create_file:
274 	usb_deregister(&stub_driver);
275 err_usb_register:
276 	kmem_cache_destroy(stub_priv_cache);
277 	return ret;
278 }
279 
usbip_host_exit(void)280 static 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 
294 module_init(usbip_host_init);
295 module_exit(usbip_host_exit);
296 
297 MODULE_AUTHOR(DRIVER_AUTHOR);
298 MODULE_DESCRIPTION(DRIVER_DESC);
299 MODULE_LICENSE("GPL");
300 MODULE_VERSION(USBIP_VERSION);
301