xref: /openbmc/linux/drivers/usb/usbip/stub_main.c (revision f3539c12)
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 
30 struct 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
37 static struct bus_id_priv busid_table[MAX_BUSID];
38 static spinlock_t busid_table_lock;
39 
40 static 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  */
55 static 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 
69 struct 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 
83 static 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 
105 out:
106 	spin_unlock(&busid_table_lock);
107 
108 	return ret;
109 }
110 
111 int 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 
131 out:
132 	spin_unlock(&busid_table_lock);
133 
134 	return ret;
135 }
136 
137 static 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 
152 static 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 }
184 static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
185 		   store_match_busid);
186 
187 static 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 
213 static DRIVER_ATTR_WO(rebind);
214 
215 static 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 
227 static 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 
244 done:
245 	spin_unlock_irqrestore(&sdev->priv_lock, flags);
246 
247 	return priv;
248 }
249 
250 void 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 
270 static 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 
305 err_create_file:
306 	usb_deregister_device_driver(&stub_driver);
307 err_usb_register:
308 	kmem_cache_destroy(stub_priv_cache);
309 	return ret;
310 }
311 
312 static 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 
329 module_init(usbip_host_init);
330 module_exit(usbip_host_exit);
331 
332 MODULE_AUTHOR(DRIVER_AUTHOR);
333 MODULE_DESCRIPTION(DRIVER_DESC);
334 MODULE_LICENSE("GPL");
335 MODULE_VERSION(USBIP_VERSION);
336