summaryrefslogtreecommitdiff
path: root/drivers/usb/usbip/vudc_sysfs.c
blob: 907a43a008964d647d19f9631faf4a443bc00019 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2015 Karol Kosik <karo9@interia.eu>
 * Copyright (C) 2015-2016 Samsung Electronics
 *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
 *               Krzysztof Opasiak <k.opasiak@samsung.com>
 */

#include <linux/device.h>
#include <linux/list.h>
#include <linux/usb/gadget.h>
#include <linux/usb/ch9.h>
#include <linux/sysfs.h>
#include <linux/kthread.h>
#include <linux/byteorder/generic.h>

#include "usbip_common.h"
#include "vudc.h"

#include <net/sock.h>

/* called with udc->lock held */
int get_gadget_descs(struct vudc *udc)
{
	struct vrequest *usb_req;
	struct vep *ep0 = to_vep(udc->gadget.ep0);
	struct usb_device_descriptor *ddesc = &udc->dev_desc;
	struct usb_ctrlrequest req;
	int ret;

	if (!udc->driver || !udc->pullup)
		return -EINVAL;

	req.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
	req.bRequest = USB_REQ_GET_DESCRIPTOR;
	req.wValue = cpu_to_le16(USB_DT_DEVICE << 8);
	req.wIndex = cpu_to_le16(0);
	req.wLength = cpu_to_le16(sizeof(*ddesc));

	spin_unlock(&udc->lock);
	ret = udc->driver->setup(&(udc->gadget), &req);
	spin_lock(&udc->lock);
	if (ret < 0)
		goto out;

	/* assuming request queue is empty; request is now on top */
	usb_req = list_last_entry(&ep0->req_queue, struct vrequest, req_entry);
	list_del(&usb_req->req_entry);

	if (usb_req->req.length > sizeof(*ddesc)) {
		ret = -EOVERFLOW;
		goto giveback_req;
	}

	memcpy(ddesc, usb_req->req.buf, sizeof(*ddesc));
	udc->desc_cached = 1;
	ret = 0;
giveback_req:
	usb_req->req.status = 0;
	usb_req->req.actual = usb_req->req.length;
	usb_gadget_giveback_request(&(ep0->ep), &(usb_req->req));
out:
	return ret;
}

/*
 * Exposes device descriptor from the gadget driver.
 */
static ssize_t dev_desc_read(struct file *file, struct kobject *kobj,
			     struct bin_attribute *attr, char *out,
			     loff_t off, size_t count)
{
	struct device *dev = kobj_to_dev(kobj);
	struct vudc *udc = (struct vudc *)dev_get_drvdata(dev);
	char *desc_ptr = (char *) &udc->dev_desc;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&udc->lock, flags);
	if (!udc->desc_cached) {
		ret = -ENODEV;
		goto unlock;
	}

	memcpy(out, desc_ptr + off, count);
	ret = count;
unlock:
	spin_unlock_irqrestore(&udc->lock, flags);
	return ret;
}
static BIN_ATTR_RO(dev_desc, sizeof(struct usb_device_descriptor));

static ssize_t usbip_sockfd_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *in, size_t count)
{
	struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
	int rv;
	int sockfd = 0;
	int err;
	struct socket *socket;
	unsigned long flags;
	int ret;
	struct task_struct *tcp_rx = NULL;
	struct task_struct *tcp_tx = NULL;

	rv = kstrtoint(in, 0, &sockfd);
	if (rv != 0)
		return -EINVAL;

	if (!udc) {
		dev_err(dev, "no device");
		return -ENODEV;
	}
	mutex_lock(&udc->ud.sysfs_lock);
	spin_lock_irqsave(&udc->lock, flags);
	/* Don't export what we don't have */
	if (!udc->driver || !udc->pullup) {
		dev_err(dev, "gadget not bound");
		ret = -ENODEV;
		goto unlock;
	}

	if (sockfd != -1) {
		if (udc->connected) {
			dev_err(dev, "Device already connected");
			ret = -EBUSY;
			goto unlock;
		}

		spin_lock(&udc->ud.lock);

		if (udc->ud.status != SDEV_ST_AVAILABLE) {
			ret = -EINVAL;
			goto unlock_ud;
		}

		socket = sockfd_lookup(sockfd, &err);
		if (!socket) {
			dev_err(dev, "failed to lookup sock");
			ret = -EINVAL;
			goto unlock_ud;
		}

		if (socket->type != SOCK_STREAM) {
			dev_err(dev, "Expecting SOCK_STREAM - found %d",
				socket->type);
			ret = -EINVAL;
			goto sock_err;
		}

		/* unlock and create threads and get tasks */
		spin_unlock(&udc->ud.lock);
		spin_unlock_irqrestore(&udc->lock, flags);

		tcp_rx = kthread_create(&v_rx_loop, &udc->ud, "vudc_rx");
		if (IS_ERR(tcp_rx)) {
			sockfd_put(socket);
			mutex_unlock(&udc->ud.sysfs_lock);
			return -EINVAL;
		}
		tcp_tx = kthread_create(&v_tx_loop, &udc->ud, "vudc_tx");
		if (IS_ERR(tcp_tx)) {
			kthread_stop(tcp_rx);
			sockfd_put(socket);
			mutex_unlock(&udc->ud.sysfs_lock);
			return -EINVAL;
		}

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

		/* lock and update udc->ud state */
		spin_lock_irqsave(&udc->lock, flags);
		spin_lock(&udc->ud.lock);

		udc->ud.tcp_socket = socket;
		udc->ud.tcp_rx = tcp_rx;
		udc->ud.tcp_tx = tcp_tx;
		udc->ud.status = SDEV_ST_USED;

		spin_unlock(&udc->ud.lock);

		ktime_get_ts64(&udc->start_time);
		v_start_timer(udc);
		udc->connected = 1;

		spin_unlock_irqrestore(&udc->lock, flags);

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

		mutex_unlock(&udc->ud.sysfs_lock);
		return count;

	} else {
		if (!udc->connected) {
			dev_err(dev, "Device not connected");
			ret = -EINVAL;
			goto unlock;
		}

		spin_lock(&udc->ud.lock);
		if (udc->ud.status != SDEV_ST_USED) {
			ret = -EINVAL;
			goto unlock_ud;
		}
		spin_unlock(&udc->ud.lock);

		usbip_event_add(&udc->ud, VUDC_EVENT_DOWN);
	}

	spin_unlock_irqrestore(&udc->lock, flags);
	mutex_unlock(&udc->ud.sysfs_lock);

	return count;

sock_err:
	sockfd_put(socket);
unlock_ud:
	spin_unlock(&udc->ud.lock);
unlock:
	spin_unlock_irqrestore(&udc->lock, flags);
	mutex_unlock(&udc->ud.sysfs_lock);

	return ret;
}
static DEVICE_ATTR_WO(usbip_sockfd);

static ssize_t usbip_status_show(struct device *dev,
			       struct device_attribute *attr, char *out)
{
	struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
	int status;

	if (!udc) {
		dev_err(dev, "no device");
		return -ENODEV;
	}
	spin_lock_irq(&udc->ud.lock);
	status = udc->ud.status;
	spin_unlock_irq(&udc->ud.lock);

	return sysfs_emit(out, "%d\n", status);
}
static DEVICE_ATTR_RO(usbip_status);

static struct attribute *dev_attrs[] = {
	&dev_attr_usbip_sockfd.attr,
	&dev_attr_usbip_status.attr,
	NULL,
};

static struct bin_attribute *dev_bin_attrs[] = {
	&bin_attr_dev_desc,
	NULL,
};

static const struct attribute_group vudc_attr_group = {
	.attrs = dev_attrs,
	.bin_attrs = dev_bin_attrs,
};

const struct attribute_group *vudc_groups[] = {
	&vudc_attr_group,
	NULL,
};