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