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/types.h>
  32 #include <linux/errno.h>
  33 #include <linux/sched.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/skbuff.h>
  37 #include <linux/miscdevice.h>
  38
  39 #include <net/bluetooth/bluetooth.h>
  40 #include <net/bluetooth/hci_core.h>
  41
  42 #ifndef CONFIG_BT_HCIVHCI_DEBUG
  43 #undef  BT_DBG
  44 #define BT_DBG(D...)
  45 #endif
  46
  47 #define VERSION "1.2"
  48
  49 static int minor = MISC_DYNAMIC_MINOR;
  50
  51 struct vhci_data {
  52         struct hci_dev *hdev;
  53
  54         unsigned long flags;
  55
  56         wait_queue_head_t read_wait;
  57         struct sk_buff_head readq;
  58
  59         struct fasync_struct *fasync;
  60 };
  61
  62 #define VHCI_FASYNC     0x0010
  63
  64 static struct miscdevice vhci_miscdev;
  65
  66 static int vhci_open_dev(struct hci_dev *hdev)
  67 {
  68         set_bit(HCI_RUNNING, &hdev->flags);
  69
  70         return 0;
  71 }
  72
  73 static int vhci_close_dev(struct hci_dev *hdev)
  74 {
  75         struct vhci_data *data = hdev->driver_data;
  76
  77         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  78                 return 0;
  79
  80         skb_queue_purge(&data->readq);
  81
  82         return 0;
  83 }
  84
  85 static int vhci_flush(struct hci_dev *hdev)
  86 {
  87         struct vhci_data *data = hdev->driver_data;
  88
  89         skb_queue_purge(&data->readq);
  90
  91         return 0;
  92 }
  93
  94 static int vhci_send_frame(struct sk_buff *skb)
  95 {
  96         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
  97         struct vhci_data *data;
  98
  99         if (!hdev) {
 100                 BT_ERR("Frame for unknown HCI device (hdev=NULL)");
 101                 return -ENODEV;
 102         }
 103
 104         if (!test_bit(HCI_RUNNING, &hdev->flags))
 105                 return -EBUSY;
 106
 107         data = hdev->driver_data;
 108
 109         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 110         skb_queue_tail(&data->readq, skb);
 111
 112         if (data->flags & VHCI_FASYNC)
 113                 kill_fasync(&data->fasync, SIGIO, POLL_IN);
 114
 115         wake_up_interruptible(&data->read_wait);
 116
 117         return 0;
 118 }
 119
 120 static void vhci_destruct(struct hci_dev *hdev)
 121 {
 122         kfree(hdev->driver_data);
 123 }
 124
 125 static inline ssize_t vhci_get_user(struct vhci_data *data,
 126                                         const char __user *buf, size_t count)
 127 {
 128         struct sk_buff *skb;
 129
 130         if (count > HCI_MAX_FRAME_SIZE)
 131                 return -EINVAL;
 132
 133         skb = bt_skb_alloc(count, GFP_KERNEL);
 134         if (!skb)
 135                 return -ENOMEM;
 136
 137         if (copy_from_user(skb_put(skb, count), buf, count)) {
 138                 kfree_skb(skb);
 139                 return -EFAULT;
 140         }
 141
 142         skb->dev = (void *) data->hdev;
 143         bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
 144         skb_pull(skb, 1);
 145
 146         hci_recv_frame(skb);
 147
 148         return count;
 149 }
 150
 151 static inline ssize_t vhci_put_user(struct vhci_data *data,
 152                         struct sk_buff *skb, char __user *buf, int count)
 153 {
 154         char __user *ptr = buf;
 155         int len, total = 0;
 156
 157         len = min_t(unsigned int, skb->len, count);
 158
 159         if (copy_to_user(ptr, skb->data, len))
 160                 return -EFAULT;
 161
 162         total += len;
 163
 164         data->hdev->stat.byte_tx += len;
 165
 166         switch (bt_cb(skb)->pkt_type) {
 167         case HCI_COMMAND_PKT:
 168                 data->hdev->stat.cmd_tx++;
 169                 break;
 170
 171         case HCI_ACLDATA_PKT:
 172                 data->hdev->stat.acl_tx++;
 173                 break;
 174
 175         case HCI_SCODATA_PKT:
 176                 data->hdev->stat.cmd_tx++;
 177                 break;
 178         };
 179
 180         return total;
 181 }
 182
 183 static loff_t vhci_llseek(struct file *file, loff_t offset, int origin)
 184 {
 185         return -ESPIPE;
 186 }
 187
 188 static ssize_t vhci_read(struct file *file,
 189                                 char __user *buf, size_t count, loff_t *pos)
 190 {
 191         DECLARE_WAITQUEUE(wait, current);
 192         struct vhci_data *data = file->private_data;
 193         struct sk_buff *skb;
 194         ssize_t ret = 0;
 195
 196         add_wait_queue(&data->read_wait, &wait);
 197         while (count) {
 198                 set_current_state(TASK_INTERRUPTIBLE);
 199
 200                 skb = skb_dequeue(&data->readq);
 201                 if (!skb) {
 202                         if (file->f_flags & O_NONBLOCK) {
 203                                 ret = -EAGAIN;
 204                                 break;
 205                         }
 206
 207                         if (signal_pending(current)) {
 208                                 ret = -ERESTARTSYS;
 209                                 break;
 210                         }
 211
 212                         schedule();
 213                         continue;
 214                 }
 215
 216                 if (access_ok(VERIFY_WRITE, buf, count))
 217                         ret = vhci_put_user(data, skb, buf, count);
 218                 else
 219                         ret = -EFAULT;
 220
 221                 kfree_skb(skb);
 222                 break;
 223         }
 224         set_current_state(TASK_RUNNING);
 225         remove_wait_queue(&data->read_wait, &wait);
 226
 227         return ret;
 228 }
 229
 230 static ssize_t vhci_write(struct file *file,
 231                         const char __user *buf, size_t count, loff_t *pos)
 232 {
 233         struct vhci_data *data = file->private_data;
 234
 235         if (!access_ok(VERIFY_READ, buf, count))
 236                 return -EFAULT;
 237
 238         return vhci_get_user(data, buf, count);
 239 }
 240
 241 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 242 {
 243         struct vhci_data *data = file->private_data;
 244
 245         poll_wait(file, &data->read_wait, wait);
 246
 247         if (!skb_queue_empty(&data->readq))
 248                 return POLLIN | POLLRDNORM;
 249
 250         return POLLOUT | POLLWRNORM;
 251 }
 252
 253 static int vhci_ioctl(struct inode *inode, struct file *file,
 254                                         unsigned int cmd, unsigned long arg)
 255 {
 256         return -EINVAL;
 257 }
 258
 259 static int vhci_open(struct inode *inode, struct file *file)
 260 {
 261         struct vhci_data *data;
 262         struct hci_dev *hdev;
 263
 264         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 265         if (!data)
 266                 return -ENOMEM;
 267
 268         skb_queue_head_init(&data->readq);
 269         init_waitqueue_head(&data->read_wait);
 270
 271         hdev = hci_alloc_dev();
 272         if (!hdev) {
 273                 kfree(data);
 274                 return -ENOMEM;
 275         }
 276
 277         data->hdev = hdev;
 278
 279         hdev->type = HCI_VIRTUAL;
 280         hdev->driver_data = data;
 281
 282         hdev->open     = vhci_open_dev;
 283         hdev->close    = vhci_close_dev;
 284         hdev->flush    = vhci_flush;
 285         hdev->send     = vhci_send_frame;
 286         hdev->destruct = vhci_destruct;
 287
 288         hdev->owner = THIS_MODULE;
 289
 290         if (hci_register_dev(hdev) < 0) {
 291                 BT_ERR("Can't register HCI device");
 292                 kfree(data);
 293                 hci_free_dev(hdev);
 294                 return -EBUSY;
 295         }
 296
 297         file->private_data = data;
 298
 299         return nonseekable_open(inode, file);
 300 }
 301
 302 static int vhci_release(struct inode *inode, struct file *file)
 303 {
 304         struct vhci_data *data = file->private_data;
 305         struct hci_dev *hdev = data->hdev;
 306
 307         if (hci_unregister_dev(hdev) < 0) {
 308                 BT_ERR("Can't unregister HCI device %s", hdev->name);
 309         }
 310
 311         hci_free_dev(hdev);
 312
 313         file->private_data = NULL;
 314
 315         return 0;
 316 }
 317
 318 static int vhci_fasync(int fd, struct file *file, int on)
 319 {
 320         struct vhci_data *data = file->private_data;
 321         int err;
 322
 323         err = fasync_helper(fd, file, on, &data->fasync);
 324         if (err < 0)
 325                 return err;
 326
 327         if (on)
 328                 data->flags |= VHCI_FASYNC;
 329         else
 330                 data->flags &= ~VHCI_FASYNC;
 331
 332         return 0;
 333 }
 334
 335 static const struct file_operations vhci_fops = {
 336         .owner          = THIS_MODULE,
 337         .llseek         = vhci_llseek,
 338         .read           = vhci_read,
 339         .write          = vhci_write,
 340         .poll           = vhci_poll,
 341         .ioctl          = vhci_ioctl,
 342         .open           = vhci_open,
 343         .release        = vhci_release,
 344         .fasync         = vhci_fasync,
 345 };
 346
 347 static struct miscdevice vhci_miscdev= {
 348         .name           = "vhci",
 349         .fops           = &vhci_fops,
 350 };
 351
 352 static int __init vhci_init(void)
 353 {
 354         BT_INFO("Virtual HCI driver ver %s", VERSION);
 355
 356         vhci_miscdev.minor = minor;
 357
 358         if (misc_register(&vhci_miscdev) < 0) {
 359                 BT_ERR("Can't register misc device with minor %d", minor);
 360                 return -EIO;
 361         }
 362
 363         return 0;
 364 }
 365
 366 static void __exit vhci_exit(void)
 367 {
 368         if (misc_deregister(&vhci_miscdev) < 0)
 369                 BT_ERR("Can't unregister misc device with minor %d", minor);
 370 }
 371
 372 module_init(vhci_init);
 373 module_exit(vhci_exit);
 374
 375 module_param(minor, int, 0444);
 376 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
 377
 378 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
 379 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 380 MODULE_VERSION(VERSION);
 381 MODULE_LICENSE("GPL");