summaryrefslogtreecommitdiffstats
path: root/drivers/usb/usbip/vhci_sysfs.c
blob: c4b4256e5dad3b0f3d432dfa86e86133f9305b10 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 * Copyright (C) 2015-2016 Nobuo Iwata
 */

#include <linux/kthread.h>
#include <linux/file.h>
#include <linux/net.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/* Hardening for Spectre-v1 */
#include <linux/nospec.h>

#include "usbip_common.h"
#include "vhci.h"

/* TODO: refine locking ?*/

/*
 * output example:
 * hub port sta spd dev       sockfd local_busid
 * hs  0000 004 000 00000000  000003 1-2.3
 * ................................................
 * ss  0008 004 000 00000000  000004 2-3.4
 * ................................................
 *
 * Output includes socket fd instead of socket pointer address to avoid
 * leaking kernel memory address in:
 *	/sys/devices/platform/vhci_hcd.0/status and in debug output.
 * The socket pointer address is not used at the moment and it was made
 * visible as a convenient way to find IP address from socket pointer
 * address by looking up /proc/net/{tcp,tcp6}. As this opens a security
 * hole, the change is made to use sockfd instead.
 *
 */
static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev)
{
	if (hub == HUB_SPEED_HIGH)
		*out += sprintf(*out, "hs  %04u %03u ",
				      port, vdev->ud.status);
	else /* hub == HUB_SPEED_SUPER */
		*out += sprintf(*out, "ss  %04u %03u ",
				      port, vdev->ud.status);

	if (vdev->ud.status == VDEV_ST_USED) {
		*out += sprintf(*out, "%03u %08x ",
				      vdev->speed, vdev->devid);
		*out += sprintf(*out, "%06u %s",
				      vdev->ud.sockfd,
				      dev_name(&vdev->udev->dev));

	} else {
		*out += sprintf(*out, "000 00000000 ");
		*out += sprintf(*out, "000000 0-0");
	}

	*out += sprintf(*out, "\n");
}

/* Sysfs entry to show port status */
static ssize_t status_show_vhci(int pdev_nr, char *out)
{
	struct platform_device *pdev = vhcis[pdev_nr].pdev;
	struct vhci *vhci;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	char *s = out;
	int i;
	unsigned long flags;

	if (!pdev || !out) {
		usbip_dbg_vhci_sysfs("show status error\n");
		return 0;
	}

	hcd = platform_get_drvdata(pdev);
	vhci_hcd = hcd_to_vhci_hcd(hcd);
	vhci = vhci_hcd->vhci;

	spin_lock_irqsave(&vhci->lock, flags);

	for (i = 0; i < VHCI_HC_PORTS; i++) {
		struct vhci_device *vdev = &vhci->vhci_hcd_hs->vdev[i];

		spin_lock(&vdev->ud.lock);
		port_show_vhci(&out, HUB_SPEED_HIGH,
			       pdev_nr * VHCI_PORTS + i, vdev);
		spin_unlock(&vdev->ud.lock);
	}

	for (i = 0; i < VHCI_HC_PORTS; i++) {
		struct vhci_device *vdev = &vhci->vhci_hcd_ss->vdev[i];

		spin_lock(&vdev->ud.lock);
		port_show_vhci(&out, HUB_SPEED_SUPER,
			       pdev_nr * VHCI_PORTS + VHCI_HC_PORTS + i, vdev);
		spin_unlock(&vdev->ud.lock);
	}

	spin_unlock_irqrestore(&vhci->lock, flags);

	return out - s;
}

static ssize_t status_show_not_ready(int pdev_nr, char *out)
{
	char *s = out;
	int i = 0;

	for (i = 0; i < VHCI_HC_PORTS; i++) {
		out += sprintf(out, "hs  %04u %03u ",
				    (pdev_nr * VHCI_PORTS) + i,
				    VDEV_ST_NOTASSIGNED);
		out += sprintf(out, "000 00000000 0000000000000000 0-0");
		out += sprintf(out, "\n");
	}

	for (i = 0; i < VHCI_HC_PORTS; i++) {
		out += sprintf(out, "ss  %04u %03u ",
				    (pdev_nr * VHCI_PORTS) + VHCI_HC_PORTS + i,
				    VDEV_ST_NOTASSIGNED);
		out += sprintf(out, "000 00000000 0000000000000000 0-0");
		out += sprintf(out, "\n");
	}
	return out - s;
}

static int status_name_to_id(const char *name)
{
	char *c;
	long val;
	int ret;

	c = strchr(name, '.');
	if (c == NULL)
		return 0;

	ret = kstrtol(c+1, 10, &val);
	if (ret < 0)
		return ret;

	return val;
}

static ssize_t status_show(struct device *dev,
			   struct device_attribute *attr, char *out)
{
	char *s = out;
	int pdev_nr;

	out += sprintf(out,
		       "hub port sta spd dev      sockfd local_busid\n");

	pdev_nr = status_name_to_id(attr->attr.name);
	if (pdev_nr < 0)
		out += status_show_not_ready(pdev_nr, out);
	else
		out += status_show_vhci(pdev_nr, out);

	return out - s;
}

static ssize_t nports_show(struct device *dev, struct device_attribute *attr,
			   char *out)
{
	char *s = out;

	/*
	 * Half the ports are for SPEED_HIGH and half for SPEED_SUPER,
	 * thus the * 2.
	 */
	out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers);
	return out - s;
}
static DEVICE_ATTR_RO(nports);

/* Sysfs entry to shutdown a virtual connection */
static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
{
	struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
	struct vhci *vhci = vhci_hcd->vhci;
	unsigned long flags;

	usbip_dbg_vhci_sysfs("enter\n");

	/* lock */
	spin_lock_irqsave(&vhci->lock, flags);
	spin_lock(&vdev->ud.lock);

	if (vdev->ud.status == VDEV_ST_NULL) {
		pr_err("not connected %d\n", vdev->ud.status);

		/* unlock */
		spin_unlock(&vdev->ud.lock);
		spin_unlock_irqrestore(&vhci->lock, flags);

		return -EINVAL;
	}

	/* unlock */
	spin_unlock(&vdev->ud.lock);
	spin_unlock_irqrestore(&vhci->lock, flags);

	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);

	return 0;
}

static int valid_port(__u32 *pdev_nr, __u32 *rhport)
{
	if (*pdev_nr >= vhci_num_controllers) {
		pr_err("pdev %u\n", *pdev_nr);
		return 0;
	}
	*pdev_nr = array_index_nospec(*pdev_nr, vhci_num_controllers);

	if (*rhport >= VHCI_HC_PORTS) {
		pr_err("rhport %u\n", *rhport);
		return 0;
	}
	*rhport = array_index_nospec(*rhport, VHCI_HC_PORTS);

	return 1;
}

static ssize_t detach_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	__u32 port = 0, pdev_nr = 0, rhport = 0;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	int ret;

	if (kstrtoint(buf, 10, &port) < 0)
		return -EINVAL;

	pdev_nr = port_to_pdev_nr(port);
	rhport = port_to_rhport(port);

	if (!valid_port(&pdev_nr, &rhport))
		return -EINVAL;

	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
	if (hcd == NULL) {
		dev_err(dev, "port is not ready %u\n", port);
		return -EAGAIN;
	}

	usbip_dbg_vhci_sysfs("rhport %d\n", rhport);

	if ((port / VHCI_HC_PORTS) % 2)
		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_ss;
	else
		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_hs;

	ret = vhci_port_disconnect(vhci_hcd, rhport);
	if (ret < 0)
		return -EINVAL;

	usbip_dbg_vhci_sysfs("Leave\n");

	return count;
}
static DEVICE_ATTR_WO(detach);

static int valid_args(__u32 *pdev_nr, __u32 *rhport,
		      enum usb_device_speed speed)
{
	if (!valid_port(pdev_nr, rhport)) {
		return 0;
	}

	switch (speed) {
	case USB_SPEED_LOW:
	case USB_SPEED_FULL:
	case USB_SPEED_HIGH:
	case USB_SPEED_WIRELESS:
	case USB_SPEED_SUPER:
		break;
	default:
		pr_err("Failed attach request for unsupported USB speed: %s\n",
			usb_speed_string(speed));
		return 0;
	}

	return 1;
}

/* Sysfs entry to establish a virtual connection */
/*
 * To start a new USB/IP attachment, a userland program needs to setup a TCP
 * connection and then write its socket descriptor with remote device
 * information into this sysfs file.
 *
 * A remote device is virtually attached to the root-hub port of @rhport with
 * @speed. @devid is embedded into a request to specify the remote device in a
 * server host.
 *
 * write() returns 0 on success, else negative errno.
 */
static ssize_t attach_store(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct socket *socket;
	int sockfd = 0;
	__u32 port = 0, pdev_nr = 0, rhport = 0, devid = 0, speed = 0;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	struct vhci_device *vdev;
	struct vhci *vhci;
	int err;
	unsigned long flags;
	struct task_struct *tcp_rx = NULL;
	struct task_struct *tcp_tx = NULL;

	/*
	 * @rhport: port number of vhci_hcd
	 * @sockfd: socket descriptor of an established TCP connection
	 * @devid: unique device identifier in a remote host
	 * @speed: usb device speed in a remote host
	 */
	if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
		return -EINVAL;
	pdev_nr = port_to_pdev_nr(port);
	rhport = port_to_rhport(port);

	usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
			     port, pdev_nr, rhport);
	usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
			     sockfd, devid, speed);

	/* check received parameters */
	if (!valid_args(&pdev_nr, &rhport, speed))
		return -EINVAL;

	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
	if (hcd == NULL) {
		dev_err(dev, "port %d is not ready\n", port);
		return -EAGAIN;
	}

	vhci_hcd = hcd_to_vhci_hcd(hcd);
	vhci = vhci_hcd->vhci;

	if (speed == USB_SPEED_SUPER)
		vdev = &vhci->vhci_hcd_ss->vdev[rhport];
	else
		vdev = &vhci->vhci_hcd_hs->vdev[rhport];

	/* Extract socket from fd. */
	socket = sockfd_lookup(sockfd, &err);
	if (!socket) {
		dev_err(dev, "failed to lookup sock");
		return -EINVAL;
	}
	if (socket->type != SOCK_STREAM) {
		dev_err(dev, "Expecting SOCK_STREAM - found %d",
			socket->type);
		sockfd_put(socket);
		return -EINVAL;
	}

	/* create threads before locking */
	tcp_rx = kthread_create(vhci_rx_loop, &vdev->ud, "vhci_rx");
	if (IS_ERR(tcp_rx)) {
		sockfd_put(socket);
		return -EINVAL;
	}
	tcp_tx = kthread_create(vhci_tx_loop, &vdev->ud, "vhci_tx");
	if (IS_ERR(tcp_tx)) {
		kthread_stop(tcp_rx);
		sockfd_put(socket);
		return -EINVAL;
	}

	/* get task structs now */
	get_task_struct(tcp_rx);
	get_task_struct(tcp_tx);

	/* now begin lock until setting vdev status set */
	spin_lock_irqsave(&vhci->lock, flags);
	spin_lock(&vdev->ud.lock);

	if (vdev->ud.status != VDEV_ST_NULL) {
		/* end of the lock */
		spin_unlock(&vdev->ud.lock);
		spin_unlock_irqrestore(&vhci->lock, flags);

		sockfd_put(socket);
		kthread_stop_put(tcp_rx);
		kthread_stop_put(tcp_tx);

		dev_err(dev, "port %d already used\n", rhport);
		/*
		 * Will be retried from userspace
		 * if there's another free port.
		 */
		return -EBUSY;
	}

	dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
		 pdev_nr, rhport, sockfd);
	dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
		 devid, speed, usb_speed_string(speed));

	vdev->devid         = devid;
	vdev->speed         = speed;
	vdev->ud.sockfd     = sockfd;
	vdev->ud.tcp_socket = socket;
	vdev->ud.tcp_rx     = tcp_rx;
	vdev->ud.tcp_tx     = tcp_tx;
	vdev->ud.status     = VDEV_ST_NOTASSIGNED;
	usbip_kcov_handle_init(&vdev->ud);

	spin_unlock(&vdev->ud.lock);
	spin_unlock_irqrestore(&vhci->lock, flags);
	/* end the lock */

	wake_up_process(vdev->ud.tcp_rx);
	wake_up_process(vdev->ud.tcp_tx);

	rh_port_connect(vdev, speed);

	return count;
}
static DEVICE_ATTR_WO(attach);

#define MAX_STATUS_NAME 16

struct status_attr {
	struct device_attribute attr;
	char name[MAX_STATUS_NAME+1];
};

static struct status_attr *status_attrs;

static void set_status_attr(int id)
{
	struct status_attr *status;

	status = status_attrs + id;
	if (id == 0)
		strcpy(status->name, "status");
	else
		snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
	status->attr.attr.name = status->name;
	status->attr.attr.mode = S_IRUGO;
	status->attr.show = status_show;
	sysfs_attr_init(&status->attr.attr);
}

static int init_status_attrs(void)
{
	int id;

	status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
			       GFP_KERNEL);
	if (status_attrs == NULL)
		return -ENOMEM;

	for (id = 0; id < vhci_num_controllers; id++)
		set_status_attr(id);

	return 0;
}

static void finish_status_attrs(void)
{
	kfree(status_attrs);
}

struct attribute_group vhci_attr_group = {
	.attrs = NULL,
};

int vhci_init_attr_group(void)
{
	struct attribute **attrs;
	int ret, i;

	attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
			GFP_KERNEL);
	if (attrs == NULL)
		return -ENOMEM;

	ret = init_status_attrs();
	if (ret) {
		kfree(attrs);
		return ret;
	}
	*attrs = &dev_attr_nports.attr;
	*(attrs + 1) = &dev_attr_detach.attr;
	*(attrs + 2) = &dev_attr_attach.attr;
	*(attrs + 3) = &dev_attr_usbip_debug.attr;
	for (i = 0; i < vhci_num_controllers; i++)
		*(attrs + i + 4) = &((status_attrs + i)->attr.attr);
	vhci_attr_group.attrs = attrs;
	return 0;
}

void vhci_finish_attr_group(void)
{
	finish_status_attrs();
	kfree(vhci_attr_group.attrs);
}