1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2015 Karol Kosik <karo9@interia.eu>
4 * Copyright (C) 2015-2016 Samsung Electronics
5 * Igor Kotrasinski <i.kotrasinsk@samsung.com>
6 * Krzysztof Opasiak <k.opasiak@samsung.com>
7 */
8
9 #include <linux/device.h>
10 #include <linux/list.h>
11 #include <linux/usb/gadget.h>
12 #include <linux/usb/ch9.h>
13 #include <linux/sysfs.h>
14 #include <linux/kthread.h>
15 #include <linux/byteorder/generic.h>
16
17 #include "usbip_common.h"
18 #include "vudc.h"
19
20 #include <net/sock.h>
21
22 /* called with udc->lock held */
get_gadget_descs(struct vudc * udc)23 int get_gadget_descs(struct vudc *udc)
24 {
25 struct vrequest *usb_req;
26 struct vep *ep0 = to_vep(udc->gadget.ep0);
27 struct usb_device_descriptor *ddesc = &udc->dev_desc;
28 struct usb_ctrlrequest req;
29 int ret;
30
31 if (!udc->driver || !udc->pullup)
32 return -EINVAL;
33
34 req.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
35 req.bRequest = USB_REQ_GET_DESCRIPTOR;
36 req.wValue = cpu_to_le16(USB_DT_DEVICE << 8);
37 req.wIndex = cpu_to_le16(0);
38 req.wLength = cpu_to_le16(sizeof(*ddesc));
39
40 spin_unlock(&udc->lock);
41 ret = udc->driver->setup(&(udc->gadget), &req);
42 spin_lock(&udc->lock);
43 if (ret < 0)
44 goto out;
45
46 /* assuming request queue is empty; request is now on top */
47 usb_req = list_last_entry(&ep0->req_queue, struct vrequest, req_entry);
48 list_del(&usb_req->req_entry);
49
50 if (usb_req->req.length > sizeof(*ddesc)) {
51 ret = -EOVERFLOW;
52 goto giveback_req;
53 }
54
55 memcpy(ddesc, usb_req->req.buf, sizeof(*ddesc));
56 udc->desc_cached = 1;
57 ret = 0;
58 giveback_req:
59 usb_req->req.status = 0;
60 usb_req->req.actual = usb_req->req.length;
61 usb_gadget_giveback_request(&(ep0->ep), &(usb_req->req));
62 out:
63 return ret;
64 }
65
66 /*
67 * Exposes device descriptor from the gadget driver.
68 */
dev_desc_read(struct file * file,struct kobject * kobj,struct bin_attribute * attr,char * out,loff_t off,size_t count)69 static ssize_t dev_desc_read(struct file *file, struct kobject *kobj,
70 struct bin_attribute *attr, char *out,
71 loff_t off, size_t count)
72 {
73 struct device *dev = kobj_to_dev(kobj);
74 struct vudc *udc = (struct vudc *)dev_get_drvdata(dev);
75 char *desc_ptr = (char *) &udc->dev_desc;
76 unsigned long flags;
77 int ret;
78
79 spin_lock_irqsave(&udc->lock, flags);
80 if (!udc->desc_cached) {
81 ret = -ENODEV;
82 goto unlock;
83 }
84
85 memcpy(out, desc_ptr + off, count);
86 ret = count;
87 unlock:
88 spin_unlock_irqrestore(&udc->lock, flags);
89 return ret;
90 }
91 static BIN_ATTR_RO(dev_desc, sizeof(struct usb_device_descriptor));
92
usbip_sockfd_store(struct device * dev,struct device_attribute * attr,const char * in,size_t count)93 static ssize_t usbip_sockfd_store(struct device *dev,
94 struct device_attribute *attr,
95 const char *in, size_t count)
96 {
97 struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
98 int rv;
99 int sockfd = 0;
100 int err;
101 struct socket *socket;
102 unsigned long flags;
103 int ret;
104 struct task_struct *tcp_rx = NULL;
105 struct task_struct *tcp_tx = NULL;
106
107 rv = kstrtoint(in, 0, &sockfd);
108 if (rv != 0)
109 return -EINVAL;
110
111 if (!udc) {
112 dev_err(dev, "no device");
113 return -ENODEV;
114 }
115 mutex_lock(&udc->ud.sysfs_lock);
116 spin_lock_irqsave(&udc->lock, flags);
117 /* Don't export what we don't have */
118 if (!udc->driver || !udc->pullup) {
119 dev_err(dev, "gadget not bound");
120 ret = -ENODEV;
121 goto unlock;
122 }
123
124 if (sockfd != -1) {
125 if (udc->connected) {
126 dev_err(dev, "Device already connected");
127 ret = -EBUSY;
128 goto unlock;
129 }
130
131 spin_lock(&udc->ud.lock);
132
133 if (udc->ud.status != SDEV_ST_AVAILABLE) {
134 ret = -EINVAL;
135 goto unlock_ud;
136 }
137
138 socket = sockfd_lookup(sockfd, &err);
139 if (!socket) {
140 dev_err(dev, "failed to lookup sock");
141 ret = -EINVAL;
142 goto unlock_ud;
143 }
144
145 if (socket->type != SOCK_STREAM) {
146 dev_err(dev, "Expecting SOCK_STREAM - found %d",
147 socket->type);
148 ret = -EINVAL;
149 goto sock_err;
150 }
151
152 /* unlock and create threads and get tasks */
153 spin_unlock(&udc->ud.lock);
154 spin_unlock_irqrestore(&udc->lock, flags);
155
156 tcp_rx = kthread_create(&v_rx_loop, &udc->ud, "vudc_rx");
157 if (IS_ERR(tcp_rx)) {
158 sockfd_put(socket);
159 mutex_unlock(&udc->ud.sysfs_lock);
160 return -EINVAL;
161 }
162 tcp_tx = kthread_create(&v_tx_loop, &udc->ud, "vudc_tx");
163 if (IS_ERR(tcp_tx)) {
164 kthread_stop(tcp_rx);
165 sockfd_put(socket);
166 mutex_unlock(&udc->ud.sysfs_lock);
167 return -EINVAL;
168 }
169
170 /* get task structs now */
171 get_task_struct(tcp_rx);
172 get_task_struct(tcp_tx);
173
174 /* lock and update udc->ud state */
175 spin_lock_irqsave(&udc->lock, flags);
176 spin_lock(&udc->ud.lock);
177
178 udc->ud.tcp_socket = socket;
179 udc->ud.tcp_rx = tcp_rx;
180 udc->ud.tcp_tx = tcp_tx;
181 udc->ud.status = SDEV_ST_USED;
182
183 spin_unlock(&udc->ud.lock);
184
185 ktime_get_ts64(&udc->start_time);
186 v_start_timer(udc);
187 udc->connected = 1;
188
189 spin_unlock_irqrestore(&udc->lock, flags);
190
191 wake_up_process(udc->ud.tcp_rx);
192 wake_up_process(udc->ud.tcp_tx);
193
194 mutex_unlock(&udc->ud.sysfs_lock);
195 return count;
196
197 } else {
198 if (!udc->connected) {
199 dev_err(dev, "Device not connected");
200 ret = -EINVAL;
201 goto unlock;
202 }
203
204 spin_lock(&udc->ud.lock);
205 if (udc->ud.status != SDEV_ST_USED) {
206 ret = -EINVAL;
207 goto unlock_ud;
208 }
209 spin_unlock(&udc->ud.lock);
210
211 usbip_event_add(&udc->ud, VUDC_EVENT_DOWN);
212 }
213
214 spin_unlock_irqrestore(&udc->lock, flags);
215 mutex_unlock(&udc->ud.sysfs_lock);
216
217 return count;
218
219 sock_err:
220 sockfd_put(socket);
221 unlock_ud:
222 spin_unlock(&udc->ud.lock);
223 unlock:
224 spin_unlock_irqrestore(&udc->lock, flags);
225 mutex_unlock(&udc->ud.sysfs_lock);
226
227 return ret;
228 }
229 static DEVICE_ATTR_WO(usbip_sockfd);
230
usbip_status_show(struct device * dev,struct device_attribute * attr,char * out)231 static ssize_t usbip_status_show(struct device *dev,
232 struct device_attribute *attr, char *out)
233 {
234 struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
235 int status;
236
237 if (!udc) {
238 dev_err(dev, "no device");
239 return -ENODEV;
240 }
241 spin_lock_irq(&udc->ud.lock);
242 status = udc->ud.status;
243 spin_unlock_irq(&udc->ud.lock);
244
245 return sysfs_emit(out, "%d\n", status);
246 }
247 static DEVICE_ATTR_RO(usbip_status);
248
249 static struct attribute *dev_attrs[] = {
250 &dev_attr_usbip_sockfd.attr,
251 &dev_attr_usbip_status.attr,
252 NULL,
253 };
254
255 static struct bin_attribute *dev_bin_attrs[] = {
256 &bin_attr_dev_desc,
257 NULL,
258 };
259
260 static const struct attribute_group vudc_attr_group = {
261 .attrs = dev_attrs,
262 .bin_attrs = dev_bin_attrs,
263 };
264
265 const struct attribute_group *vudc_groups[] = {
266 &vudc_attr_group,
267 NULL,
268 };
269
