1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2003-2008 Takahiro Hirofuchi
4 */
5
6 #include <linux/string.h>
7 #include <linux/module.h>
8 #include <linux/device.h>
9
10 #include "usbip_common.h"
11 #include "stub.h"
12
13 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
14 #define DRIVER_DESC "USB/IP Host Driver"
15
16 struct kmem_cache *stub_priv_cache;
17
18 /*
19 * busid_tables defines matching busids that usbip can grab. A user can change
20 * dynamically what device is locally used and what device is exported to a
21 * remote host.
22 */
23 #define MAX_BUSID 16
24 static struct bus_id_priv busid_table[MAX_BUSID];
25 static spinlock_t busid_table_lock;
26
init_busid_table(void)27 static void init_busid_table(void)
28 {
29 int i;
30
31 /*
32 * This also sets the bus_table[i].status to
33 * STUB_BUSID_OTHER, which is 0.
34 */
35 memset(busid_table, 0, sizeof(busid_table));
36
37 spin_lock_init(&busid_table_lock);
38
39 for (i = 0; i < MAX_BUSID; i++)
40 spin_lock_init(&busid_table[i].busid_lock);
41 }
42
43 /*
44 * Find the index of the busid by name.
45 * Must be called with busid_table_lock held.
46 */
get_busid_idx(const char * busid)47 static int get_busid_idx(const char *busid)
48 {
49 int i;
50 int idx = -1;
51
52 for (i = 0; i < MAX_BUSID; i++) {
53 spin_lock(&busid_table[i].busid_lock);
54 if (busid_table[i].name[0])
55 if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
56 idx = i;
57 spin_unlock(&busid_table[i].busid_lock);
58 break;
59 }
60 spin_unlock(&busid_table[i].busid_lock);
61 }
62 return idx;
63 }
64
65 /* Returns holding busid_lock. Should call put_busid_priv() to unlock */
get_busid_priv(const char * busid)66 struct bus_id_priv *get_busid_priv(const char *busid)
67 {
68 int idx;
69 struct bus_id_priv *bid = NULL;
70
71 spin_lock(&busid_table_lock);
72 idx = get_busid_idx(busid);
73 if (idx >= 0) {
74 bid = &(busid_table[idx]);
75 /* get busid_lock before returning */
76 spin_lock(&bid->busid_lock);
77 }
78 spin_unlock(&busid_table_lock);
79
80 return bid;
81 }
82
put_busid_priv(struct bus_id_priv * bid)83 void put_busid_priv(struct bus_id_priv *bid)
84 {
85 if (bid)
86 spin_unlock(&bid->busid_lock);
87 }
88
add_match_busid(char * busid)89 static int add_match_busid(char *busid)
90 {
91 int i;
92 int ret = -1;
93
94 spin_lock(&busid_table_lock);
95 /* already registered? */
96 if (get_busid_idx(busid) >= 0) {
97 ret = 0;
98 goto out;
99 }
100
101 for (i = 0; i < MAX_BUSID; i++) {
102 spin_lock(&busid_table[i].busid_lock);
103 if (!busid_table[i].name[0]) {
104 strlcpy(busid_table[i].name, busid, BUSID_SIZE);
105 if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
106 (busid_table[i].status != STUB_BUSID_REMOV))
107 busid_table[i].status = STUB_BUSID_ADDED;
108 ret = 0;
109 spin_unlock(&busid_table[i].busid_lock);
110 break;
111 }
112 spin_unlock(&busid_table[i].busid_lock);
113 }
114
115 out:
116 spin_unlock(&busid_table_lock);
117
118 return ret;
119 }
120
del_match_busid(char * busid)121 int del_match_busid(char *busid)
122 {
123 int idx;
124 int ret = -1;
125
126 spin_lock(&busid_table_lock);
127 idx = get_busid_idx(busid);
128 if (idx < 0)
129 goto out;
130
131 /* found */
132 ret = 0;
133
134 spin_lock(&busid_table[idx].busid_lock);
135
136 if (busid_table[idx].status == STUB_BUSID_OTHER)
137 memset(busid_table[idx].name, 0, BUSID_SIZE);
138
139 if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
140 (busid_table[idx].status != STUB_BUSID_ADDED))
141 busid_table[idx].status = STUB_BUSID_REMOV;
142
143 spin_unlock(&busid_table[idx].busid_lock);
144 out:
145 spin_unlock(&busid_table_lock);
146
147 return ret;
148 }
149
match_busid_show(struct device_driver * drv,char * buf)150 static ssize_t match_busid_show(struct device_driver *drv, char *buf)
151 {
152 int i;
153 char *out = buf;
154
155 spin_lock(&busid_table_lock);
156 for (i = 0; i < MAX_BUSID; i++) {
157 spin_lock(&busid_table[i].busid_lock);
158 if (busid_table[i].name[0])
159 out += sprintf(out, "%s ", busid_table[i].name);
160 spin_unlock(&busid_table[i].busid_lock);
161 }
162 spin_unlock(&busid_table_lock);
163 out += sprintf(out, "\n");
164
165 return out - buf;
166 }
167
match_busid_store(struct device_driver * dev,const char * buf,size_t count)168 static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
169 size_t count)
170 {
171 int len;
172 char busid[BUSID_SIZE];
173
174 if (count < 5)
175 return -EINVAL;
176
177 /* busid needs to include \0 termination */
178 len = strlcpy(busid, buf + 4, BUSID_SIZE);
179 if (sizeof(busid) <= len)
180 return -EINVAL;
181
182 if (!strncmp(buf, "add ", 4)) {
183 if (add_match_busid(busid) < 0)
184 return -ENOMEM;
185
186 pr_debug("add busid %s\n", busid);
187 return count;
188 }
189
190 if (!strncmp(buf, "del ", 4)) {
191 if (del_match_busid(busid) < 0)
192 return -ENODEV;
193
194 pr_debug("del busid %s\n", busid);
195 return count;
196 }
197
198 return -EINVAL;
199 }
200 static DRIVER_ATTR_RW(match_busid);
201
do_rebind(char * busid,struct bus_id_priv * busid_priv)202 static int do_rebind(char *busid, struct bus_id_priv *busid_priv)
203 {
204 int ret;
205
206 /* device_attach() callers should hold parent lock for USB */
207 if (busid_priv->udev->dev.parent)
208 device_lock(busid_priv->udev->dev.parent);
209 ret = device_attach(&busid_priv->udev->dev);
210 if (busid_priv->udev->dev.parent)
211 device_unlock(busid_priv->udev->dev.parent);
212 if (ret < 0) {
213 dev_err(&busid_priv->udev->dev, "rebind failed\n");
214 return ret;
215 }
216 return 0;
217 }
218
stub_device_rebind(void)219 static void stub_device_rebind(void)
220 {
221 #if IS_MODULE(CONFIG_USBIP_HOST)
222 struct bus_id_priv *busid_priv;
223 int i;
224
225 /* update status to STUB_BUSID_OTHER so probe ignores the device */
226 spin_lock(&busid_table_lock);
227 for (i = 0; i < MAX_BUSID; i++) {
228 if (busid_table[i].name[0] &&
229 busid_table[i].shutdown_busid) {
230 busid_priv = &(busid_table[i]);
231 busid_priv->status = STUB_BUSID_OTHER;
232 }
233 }
234 spin_unlock(&busid_table_lock);
235
236 /* now run rebind - no need to hold locks. driver files are removed */
237 for (i = 0; i < MAX_BUSID; i++) {
238 if (busid_table[i].name[0] &&
239 busid_table[i].shutdown_busid) {
240 busid_priv = &(busid_table[i]);
241 do_rebind(busid_table[i].name, busid_priv);
242 }
243 }
244 #endif
245 }
246
rebind_store(struct device_driver * dev,const char * buf,size_t count)247 static ssize_t rebind_store(struct device_driver *dev, const char *buf,
248 size_t count)
249 {
250 int ret;
251 int len;
252 struct bus_id_priv *bid;
253
254 /* buf length should be less that BUSID_SIZE */
255 len = strnlen(buf, BUSID_SIZE);
256
257 if (!(len < BUSID_SIZE))
258 return -EINVAL;
259
260 bid = get_busid_priv(buf);
261 if (!bid)
262 return -ENODEV;
263
264 /* mark the device for deletion so probe ignores it during rescan */
265 bid->status = STUB_BUSID_OTHER;
266 /* release the busid lock */
267 put_busid_priv(bid);
268
269 ret = do_rebind((char *) buf, bid);
270 if (ret < 0)
271 return ret;
272
273 /* delete device from busid_table */
274 del_match_busid((char *) buf);
275
276 return count;
277 }
278
279 static DRIVER_ATTR_WO(rebind);
280
stub_priv_pop_from_listhead(struct list_head * listhead)281 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
282 {
283 struct stub_priv *priv, *tmp;
284
285 list_for_each_entry_safe(priv, tmp, listhead, list) {
286 list_del(&priv->list);
287 return priv;
288 }
289
290 return NULL;
291 }
292
stub_priv_pop(struct stub_device * sdev)293 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
294 {
295 unsigned long flags;
296 struct stub_priv *priv;
297
298 spin_lock_irqsave(&sdev->priv_lock, flags);
299
300 priv = stub_priv_pop_from_listhead(&sdev->priv_init);
301 if (priv)
302 goto done;
303
304 priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
305 if (priv)
306 goto done;
307
308 priv = stub_priv_pop_from_listhead(&sdev->priv_free);
309
310 done:
311 spin_unlock_irqrestore(&sdev->priv_lock, flags);
312
313 return priv;
314 }
315
stub_device_cleanup_urbs(struct stub_device * sdev)316 void stub_device_cleanup_urbs(struct stub_device *sdev)
317 {
318 struct stub_priv *priv;
319 struct urb *urb;
320
321 dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n");
322
323 while ((priv = stub_priv_pop(sdev))) {
324 urb = priv->urb;
325 dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n",
326 priv->seqnum);
327 usb_kill_urb(urb);
328
329 kmem_cache_free(stub_priv_cache, priv);
330
331 kfree(urb->transfer_buffer);
332 urb->transfer_buffer = NULL;
333
334 kfree(urb->setup_packet);
335 urb->setup_packet = NULL;
336
337 usb_free_urb(urb);
338 }
339 }
340
usbip_host_init(void)341 static int __init usbip_host_init(void)
342 {
343 int ret;
344
345 init_busid_table();
346
347 stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
348 if (!stub_priv_cache) {
349 pr_err("kmem_cache_create failed\n");
350 return -ENOMEM;
351 }
352
353 ret = usb_register_device_driver(&stub_driver, THIS_MODULE);
354 if (ret) {
355 pr_err("usb_register failed %d\n", ret);
356 goto err_usb_register;
357 }
358
359 ret = driver_create_file(&stub_driver.drvwrap.driver,
360 &driver_attr_match_busid);
361 if (ret) {
362 pr_err("driver_create_file failed\n");
363 goto err_create_file;
364 }
365
366 ret = driver_create_file(&stub_driver.drvwrap.driver,
367 &driver_attr_rebind);
368 if (ret) {
369 pr_err("driver_create_file failed\n");
370 goto err_create_file;
371 }
372
373 return ret;
374
375 err_create_file:
376 usb_deregister_device_driver(&stub_driver);
377 err_usb_register:
378 kmem_cache_destroy(stub_priv_cache);
379 return ret;
380 }
381
usbip_host_exit(void)382 static void __exit usbip_host_exit(void)
383 {
384 driver_remove_file(&stub_driver.drvwrap.driver,
385 &driver_attr_match_busid);
386
387 driver_remove_file(&stub_driver.drvwrap.driver,
388 &driver_attr_rebind);
389
390 /*
391 * deregister() calls stub_disconnect() for all devices. Device
392 * specific data is cleared in stub_disconnect().
393 */
394 usb_deregister_device_driver(&stub_driver);
395
396 /* initiate scan to attach devices */
397 stub_device_rebind();
398
399 kmem_cache_destroy(stub_priv_cache);
400 }
401
402 module_init(usbip_host_init);
403 module_exit(usbip_host_exit);
404
405 MODULE_AUTHOR(DRIVER_AUTHOR);
406 MODULE_DESCRIPTION(DRIVER_DESC);
407 MODULE_LICENSE("GPL");
408
