drivers/usb/usbip/vudc_sysfs.c

   1 /*
   2  * Copyright (C) 2015 Karol Kosik <[email protected]>
   3  * Copyright (C) 2015-2016 Samsung Electronics
   4  *               Igor Kotrasinski <[email protected]>
   5  *               Krzysztof Opasiak <[email protected]>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <linux/device.h>
  22 #include <linux/list.h>
  23 #include <linux/usb/gadget.h>
  24 #include <linux/usb/ch9.h>
  25 #include <linux/sysfs.h>
  26 #include <linux/kthread.h>
  27 #include <linux/byteorder/generic.h>
  28
  29 #include "usbip_common.h"
  30 #include "vudc.h"
  31
  32 #include <net/sock.h>
  33
  34 /* called with udc->lock held */
  35 int get_gadget_descs(struct vudc *udc)
  36 {
  37         struct vrequest *usb_req;
  38         struct vep *ep0 = to_vep(udc->gadget.ep0);
  39         struct usb_device_descriptor *ddesc = &udc->dev_desc;
  40         struct usb_ctrlrequest req;
  41         int ret;
  42
  43         if (!udc->driver || !udc->pullup)
  44                 return -EINVAL;
  45
  46         req.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
  47         req.bRequest = USB_REQ_GET_DESCRIPTOR;
  48         req.wValue = cpu_to_le16(USB_DT_DEVICE << 8);
  49         req.wIndex = cpu_to_le16(0);
  50         req.wLength = cpu_to_le16(sizeof(*ddesc));
  51
  52         spin_unlock(&udc->lock);
  53         ret = udc->driver->setup(&(udc->gadget), &req);
  54         spin_lock(&udc->lock);
  55         if (ret < 0)
  56                 goto out;
  57
  58         /* assuming request queue is empty; request is now on top */
  59         usb_req = list_last_entry(&ep0->req_queue, struct vrequest, req_entry);
  60         list_del(&usb_req->req_entry);
  61
  62         if (usb_req->req.length > sizeof(*ddesc)) {
  63                 ret = -EOVERFLOW;
  64                 goto giveback_req;
  65         }
  66
  67         memcpy(ddesc, usb_req->req.buf, sizeof(*ddesc));
  68         udc->desc_cached = 1;
  69         ret = 0;
  70 giveback_req:
  71         usb_req->req.status = 0;
  72         usb_req->req.actual = usb_req->req.length;
  73         usb_gadget_giveback_request(&(ep0->ep), &(usb_req->req));
  74 out:
  75         return ret;
  76 }
  77
  78 /*
  79  * Exposes device descriptor from the gadget driver.
  80  */
  81 static ssize_t dev_desc_read(struct file *file, struct kobject *kobj,
  82                              struct bin_attribute *attr, char *out,
  83                              loff_t off, size_t count)
  84 {
  85         struct device *dev = kobj_to_dev(kobj);
  86         struct vudc *udc = (struct vudc *)dev_get_drvdata(dev);
  87         char *desc_ptr = (char *) &udc->dev_desc;
  88         unsigned long flags;
  89         int ret;
  90
  91         spin_lock_irqsave(&udc->lock, flags);
  92         if (!udc->desc_cached) {
  93                 ret = -ENODEV;
  94                 goto unlock;
  95         }
  96
  97         memcpy(out, desc_ptr + off, count);
  98         ret = count;
  99 unlock:
 100         spin_unlock_irqrestore(&udc->lock, flags);
 101         return ret;
 102 }
 103 static BIN_ATTR_RO(dev_desc, sizeof(struct usb_device_descriptor));
 104
 105 static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
 106                      const char *in, size_t count)
 107 {
 108         struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
 109         int rv;
 110         int sockfd = 0;
 111         int err;
 112         struct socket *socket;
 113         unsigned long flags;
 114         int ret;
 115
 116         rv = kstrtoint(in, 0, &sockfd);
 117         if (rv != 0)
 118                 return -EINVAL;
 119
 120         spin_lock_irqsave(&udc->lock, flags);
 121         /* Don't export what we don't have */
 122         if (!udc || !udc->driver || !udc->pullup) {
 123                 dev_err(dev, "no device or gadget not bound");
 124                 ret = -ENODEV;
 125                 goto unlock;
 126         }
 127
 128         if (sockfd != -1) {
 129                 if (udc->connected) {
 130                         dev_err(dev, "Device already connected");
 131                         ret = -EBUSY;
 132                         goto unlock;
 133                 }
 134
 135                 spin_lock_irq(&udc->ud.lock);
 136
 137                 if (udc->ud.status != SDEV_ST_AVAILABLE) {
 138                         ret = -EINVAL;
 139                         goto unlock_ud;
 140                 }
 141
 142                 socket = sockfd_lookup(sockfd, &err);
 143                 if (!socket) {
 144                         dev_err(dev, "failed to lookup sock");
 145                         ret = -EINVAL;
 146                         goto unlock_ud;
 147                 }
 148
 149                 udc->ud.tcp_socket = socket;
 150
 151                 spin_unlock_irq(&udc->ud.lock);
 152                 spin_unlock_irqrestore(&udc->lock, flags);
 153
 154                 udc->ud.tcp_rx = kthread_get_run(&v_rx_loop,
 155                                                     &udc->ud, "vudc_rx");
 156                 udc->ud.tcp_tx = kthread_get_run(&v_tx_loop,
 157                                                     &udc->ud, "vudc_tx");
 158
 159                 spin_lock_irqsave(&udc->lock, flags);
 160                 spin_lock_irq(&udc->ud.lock);
 161                 udc->ud.status = SDEV_ST_USED;
 162                 spin_unlock_irq(&udc->ud.lock);
 163
 164                 do_gettimeofday(&udc->start_time);
 165                 v_start_timer(udc);
 166                 udc->connected = 1;
 167         } else {
 168                 if (!udc->connected) {
 169                         dev_err(dev, "Device not connected");
 170                         ret = -EINVAL;
 171                         goto unlock;
 172                 }
 173
 174                 spin_lock_irq(&udc->ud.lock);
 175                 if (udc->ud.status != SDEV_ST_USED) {
 176                         ret = -EINVAL;
 177                         goto unlock_ud;
 178                 }
 179                 spin_unlock_irq(&udc->ud.lock);
 180
 181                 usbip_event_add(&udc->ud, VUDC_EVENT_DOWN);
 182         }
 183
 184         spin_unlock_irqrestore(&udc->lock, flags);
 185
 186         return count;
 187
 188 unlock_ud:
 189         spin_unlock_irq(&udc->ud.lock);
 190 unlock:
 191         spin_unlock_irqrestore(&udc->lock, flags);
 192
 193         return ret;
 194 }
 195 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 196
 197 static ssize_t usbip_status_show(struct device *dev,
 198                                struct device_attribute *attr, char *out)
 199 {
 200         struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
 201         int status;
 202
 203         if (!udc) {
 204                 dev_err(dev, "no device");
 205                 return -ENODEV;
 206         }
 207         spin_lock_irq(&udc->ud.lock);
 208         status = udc->ud.status;
 209         spin_unlock_irq(&udc->ud.lock);
 210
 211         return snprintf(out, PAGE_SIZE, "%d\n", status);
 212 }
 213 static DEVICE_ATTR_RO(usbip_status);
 214
 215 static struct attribute *dev_attrs[] = {
 216         &dev_attr_usbip_sockfd.attr,
 217         &dev_attr_usbip_status.attr,
 218         NULL,
 219 };
 220
 221 static struct bin_attribute *dev_bin_attrs[] = {
 222         &bin_attr_dev_desc,
 223         NULL,
 224 };
 225
 226 const struct attribute_group vudc_attr_group = {
 227         .attrs = dev_attrs,
 228         .bin_attrs = dev_bin_attrs,
 229 };