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