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 ssize_t vhci_read(struct file *file,
 184                                 char __user *buf, size_t count, loff_t *pos)
 185 {
 186         DECLARE_WAITQUEUE(wait, current);
 187         struct vhci_data *data = file->private_data;
 188         struct sk_buff *skb;
 189         ssize_t ret = 0;
 190
 191         add_wait_queue(&data->read_wait, &wait);
 192         while (count) {
 193                 set_current_state(TASK_INTERRUPTIBLE);
 194
 195                 skb = skb_dequeue(&data->readq);
 196                 if (!skb) {
 197                         if (file->f_flags & O_NONBLOCK) {
 198                                 ret = -EAGAIN;
 199                                 break;
 200                         }
 201
 202                         if (signal_pending(current)) {
 203                                 ret = -ERESTARTSYS;
 204                                 break;
 205                         }
 206
 207                         schedule();
 208                         continue;
 209                 }
 210
 211                 if (access_ok(VERIFY_WRITE, buf, count))
 212                         ret = vhci_put_user(data, skb, buf, count);
 213                 else
 214                         ret = -EFAULT;
 215
 216                 kfree_skb(skb);
 217                 break;
 218         }
 219         set_current_state(TASK_RUNNING);
 220         remove_wait_queue(&data->read_wait, &wait);
 221
 222         return ret;
 223 }
 224
 225 static ssize_t vhci_write(struct file *file,
 226                         const char __user *buf, size_t count, loff_t *pos)
 227 {
 228         struct vhci_data *data = file->private_data;
 229
 230         if (!access_ok(VERIFY_READ, buf, count))
 231                 return -EFAULT;
 232
 233         return vhci_get_user(data, buf, count);
 234 }
 235
 236 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 237 {
 238         struct vhci_data *data = file->private_data;
 239
 240         poll_wait(file, &data->read_wait, wait);
 241
 242         if (!skb_queue_empty(&data->readq))
 243                 return POLLIN | POLLRDNORM;
 244
 245         return POLLOUT | POLLWRNORM;
 246 }
 247
 248 static int vhci_ioctl(struct inode *inode, struct file *file,
 249                                         unsigned int cmd, unsigned long arg)
 250 {
 251         return -EINVAL;
 252 }
 253
 254 static int vhci_open(struct inode *inode, struct file *file)
 255 {
 256         struct vhci_data *data;
 257         struct hci_dev *hdev;
 258
 259         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 260         if (!data)
 261                 return -ENOMEM;
 262
 263         skb_queue_head_init(&data->readq);
 264         init_waitqueue_head(&data->read_wait);
 265
 266         hdev = hci_alloc_dev();
 267         if (!hdev) {
 268                 kfree(data);
 269                 return -ENOMEM;
 270         }
 271
 272         data->hdev = hdev;
 273
 274         hdev->type = HCI_VIRTUAL;
 275         hdev->driver_data = data;
 276
 277         hdev->open     = vhci_open_dev;
 278         hdev->close    = vhci_close_dev;
 279         hdev->flush    = vhci_flush;
 280         hdev->send     = vhci_send_frame;
 281         hdev->destruct = vhci_destruct;
 282
 283         hdev->owner = THIS_MODULE;
 284
 285         if (hci_register_dev(hdev) < 0) {
 286                 BT_ERR("Can't register HCI device");
 287                 kfree(data);
 288                 hci_free_dev(hdev);
 289                 return -EBUSY;
 290         }
 291
 292         file->private_data = data;
 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;
 317
 318         err = fasync_helper(fd, file, on, &data->fasync);
 319         if (err < 0)
 320                 return err;
 321
 322         if (on)
 323                 data->flags |= VHCI_FASYNC;
 324         else
 325                 data->flags &= ~VHCI_FASYNC;
 326
 327         return 0;
 328 }
 329
 330 static const struct file_operations vhci_fops = {
 331         .owner          = THIS_MODULE,
 332         .read           = vhci_read,
 333         .write          = vhci_write,
 334         .poll           = vhci_poll,
 335         .ioctl          = vhci_ioctl,
 336         .open           = vhci_open,
 337         .release        = vhci_release,
 338         .fasync         = vhci_fasync,
 339 };
 340
 341 static struct miscdevice vhci_miscdev= {
 342         .name           = "vhci",
 343         .fops           = &vhci_fops,
 344 };
 345
 346 static int __init vhci_init(void)
 347 {
 348         BT_INFO("Virtual HCI driver ver %s", VERSION);
 349
 350         vhci_miscdev.minor = minor;
 351
 352         if (misc_register(&vhci_miscdev) < 0) {
 353                 BT_ERR("Can't register misc device with minor %d", minor);
 354                 return -EIO;
 355         }
 356
 357         return 0;
 358 }
 359
 360 static void __exit vhci_exit(void)
 361 {
 362         if (misc_deregister(&vhci_miscdev) < 0)
 363                 BT_ERR("Can't unregister misc device with minor %d", minor);
 364 }
 365
 366 module_init(vhci_init);
 367 module_exit(vhci_exit);
 368
 369 module_param(minor, int, 0444);
 370 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
 371
 372 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
 373 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 374 MODULE_VERSION(VERSION);
 375 MODULE_LICENSE("GPL");