drivers/usb/usbip/vudc_sysfs.c

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