drivers/bluetooth/hci_vhci.c

   1 /*
   2  *
   3  *  Bluetooth virtual HCI driver
   4  *
   5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
   6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   7  *  Copyright (C) 2004-2006  Marcel Holtmann <marcel@holtmann.org>
   8  *
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/types.h>
  33 #include <linux/errno.h>
  34 #include <linux/sched.h>
  35 #include <linux/poll.h>
  36
  37 #include <linux/skbuff.h>
  38 #include <linux/miscdevice.h>
  39
  40 #include <net/bluetooth/bluetooth.h>
  41 #include <net/bluetooth/hci_core.h>
  42
  43 #define VERSION "1.3"
  44
  45 static int minor = MISC_DYNAMIC_MINOR;
  46
  47 struct vhci_data {
  48         struct hci_dev *hdev;
  49
  50         unsigned long flags;
  51
  52         wait_queue_head_t read_wait;
  53         struct sk_buff_head readq;
  54 };
  55
  56 static int vhci_open_dev(struct hci_dev *hdev)
  57 {
  58         set_bit(HCI_RUNNING, &hdev->flags);
  59
  60         return 0;
  61 }
  62
  63 static int vhci_close_dev(struct hci_dev *hdev)
  64 {
  65         struct vhci_data *data = hdev->driver_data;
  66
  67         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  68                 return 0;
  69
  70         skb_queue_purge(&data->readq);
  71
  72         return 0;
  73 }
  74
  75 static int vhci_flush(struct hci_dev *hdev)
  76 {
  77         struct vhci_data *data = hdev->driver_data;
  78
  79         skb_queue_purge(&data->readq);
  80
  81         return 0;
  82 }
  83
  84 static int vhci_send_frame(struct sk_buff *skb)
  85 {
  86         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
  87         struct vhci_data *data;
  88
  89         if (!hdev) {
  90                 BT_ERR("Frame for unknown HCI device (hdev=NULL)");
  91                 return -ENODEV;
  92         }
  93
  94         if (!test_bit(HCI_RUNNING, &hdev->flags))
  95                 return -EBUSY;
  96
  97         data = hdev->driver_data;
  98
  99         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 100         skb_queue_tail(&data->readq, skb);
 101
 102         wake_up_interruptible(&data->read_wait);
 103
 104         return 0;
 105 }
 106
 107 static void vhci_destruct(struct hci_dev *hdev)
 108 {
 109         kfree(hdev->driver_data);
 110 }
 111
 112 static inline ssize_t vhci_get_user(struct vhci_data *data,
 113                                         const char __user *buf, size_t count)
 114 {
 115         struct sk_buff *skb;
 116
 117         if (count > HCI_MAX_FRAME_SIZE)
 118                 return -EINVAL;
 119
 120         skb = bt_skb_alloc(count, GFP_KERNEL);
 121         if (!skb)
 122                 return -ENOMEM;
 123
 124         if (copy_from_user(skb_put(skb, count), buf, count)) {
 125                 kfree_skb(skb);
 126                 return -EFAULT;
 127         }
 128
 129         skb->dev = (void *) data->hdev;
 130         bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
 131         skb_pull(skb, 1);
 132
 133         hci_recv_frame(skb);
 134
 135         return count;
 136 }
 137
 138 static inline ssize_t vhci_put_user(struct vhci_data *data,
 139                         struct sk_buff *skb, char __user *buf, int count)
 140 {
 141         char __user *ptr = buf;
 142         int len, total = 0;
 143
 144         len = min_t(unsigned int, skb->len, count);
 145
 146         if (copy_to_user(ptr, skb->data, len))
 147                 return -EFAULT;
 148
 149         total += len;
 150
 151         data->hdev->stat.byte_tx += len;
 152
 153         switch (bt_cb(skb)->pkt_type) {
 154         case HCI_COMMAND_PKT:
 155                 data->hdev->stat.cmd_tx++;
 156                 break;
 157
 158         case HCI_ACLDATA_PKT:
 159                 data->hdev->stat.acl_tx++;
 160                 break;
 161
 162         case HCI_SCODATA_PKT:
 163                 data->hdev->stat.cmd_tx++;
 164                 break;
 165         };
 166
 167         return total;
 168 }
 169
 170 static ssize_t vhci_read(struct file *file,
 171                                 char __user *buf, size_t count, loff_t *pos)
 172 {
 173         struct vhci_data *data = file->private_data;
 174         struct sk_buff *skb;
 175         ssize_t ret = 0;
 176
 177         while (count) {
 178                 skb = skb_dequeue(&data->readq);
 179                 if (skb) {
 180                         ret = vhci_put_user(data, skb, buf, count);
 181                         if (ret < 0)
 182                                 skb_queue_head(&data->readq, skb);
 183                         else
 184                                 kfree_skb(skb);
 185                         break;
 186                 }
 187
 188                 if (file->f_flags & O_NONBLOCK) {
 189                         ret = -EAGAIN;
 190                         break;
 191                 }
 192
 193                 ret = wait_event_interruptible(data->read_wait,
 194                                         !skb_queue_empty(&data->readq));
 195                 if (ret < 0)
 196                         break;
 197         }
 198
 199         return ret;
 200 }
 201
 202 static ssize_t vhci_write(struct file *file,
 203                         const char __user *buf, size_t count, loff_t *pos)
 204 {
 205         struct vhci_data *data = file->private_data;
 206
 207         return vhci_get_user(data, buf, count);
 208 }
 209
 210 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 211 {
 212         struct vhci_data *data = file->private_data;
 213
 214         poll_wait(file, &data->read_wait, wait);
 215
 216         if (!skb_queue_empty(&data->readq))
 217                 return POLLIN | POLLRDNORM;
 218
 219         return POLLOUT | POLLWRNORM;
 220 }
 221
 222 static int vhci_ioctl(struct inode *inode, struct file *file,
 223                                         unsigned int cmd, unsigned long arg)
 224 {
 225         return -EINVAL;
 226 }
 227
 228 static int vhci_open(struct inode *inode, struct file *file)
 229 {
 230         struct vhci_data *data;
 231         struct hci_dev *hdev;
 232
 233         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 234         if (!data)
 235                 return -ENOMEM;
 236
 237         skb_queue_head_init(&data->readq);
 238         init_waitqueue_head(&data->read_wait);
 239
 240         hdev = hci_alloc_dev();
 241         if (!hdev) {
 242                 kfree(data);
 243                 return -ENOMEM;
 244         }
 245
 246         data->hdev = hdev;
 247
 248         hdev->type = HCI_VIRTUAL;
 249         hdev->driver_data = data;
 250
 251         hdev->open     = vhci_open_dev;
 252         hdev->close    = vhci_close_dev;
 253         hdev->flush    = vhci_flush;
 254         hdev->send     = vhci_send_frame;
 255         hdev->destruct = vhci_destruct;
 256
 257         hdev->owner = THIS_MODULE;
 258
 259         if (hci_register_dev(hdev) < 0) {
 260                 BT_ERR("Can't register HCI device");
 261                 kfree(data);
 262                 hci_free_dev(hdev);
 263                 return -EBUSY;
 264         }
 265
 266         file->private_data = data;
 267
 268         return nonseekable_open(inode, file);
 269 }
 270
 271 static int vhci_release(struct inode *inode, struct file *file)
 272 {
 273         struct vhci_data *data = file->private_data;
 274         struct hci_dev *hdev = data->hdev;
 275
 276         if (hci_unregister_dev(hdev) < 0) {
 277                 BT_ERR("Can't unregister HCI device %s", hdev->name);
 278         }
 279
 280         hci_free_dev(hdev);
 281
 282         file->private_data = NULL;
 283
 284         return 0;
 285 }
 286
 287 static const struct file_operations vhci_fops = {
 288         .read           = vhci_read,
 289         .write          = vhci_write,
 290         .poll           = vhci_poll,
 291         .ioctl          = vhci_ioctl,
 292         .open           = vhci_open,
 293         .release        = vhci_release,
 294 };
 295
 296 static struct miscdevice vhci_miscdev= {
 297         .name   = "vhci",
 298         .fops   = &vhci_fops,
 299         .minor  = MISC_DYNAMIC_MINOR,
 300 };
 301
 302 static int __init vhci_init(void)
 303 {
 304         BT_INFO("Virtual HCI driver ver %s", VERSION);
 305
 306         if (misc_register(&vhci_miscdev) < 0) {
 307                 BT_ERR("Can't register misc device with minor %d", minor);
 308                 return -EIO;
 309         }
 310
 311         return 0;
 312 }
 313
 314 static void __exit vhci_exit(void)
 315 {
 316         if (misc_deregister(&vhci_miscdev) < 0)
 317                 BT_ERR("Can't unregister misc device with minor %d", minor);
 318 }
 319
 320 module_init(vhci_init);
 321 module_exit(vhci_exit);
 322
 323 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 324 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 325 MODULE_VERSION(VERSION);
 326 MODULE_LICENSE("GPL");