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) 2004-2005 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 *vhci = hdev->driver_data;
  76
  77         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  78                 return 0;
  79
  80         skb_queue_purge(&vhci->readq);
  81
  82         return 0;
  83 }
  84
  85 static int vhci_flush(struct hci_dev *hdev)
  86 {
  87         struct vhci_data *vhci = hdev->driver_data;
  88
  89         skb_queue_purge(&vhci->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 *vhci;
  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         vhci = hdev->driver_data;
 108
 109         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 110         skb_queue_tail(&vhci->readq, skb);
 111
 112         if (vhci->flags & VHCI_FASYNC)
 113                 kill_fasync(&vhci->fasync, SIGIO, POLL_IN);
 114
 115         wake_up_interruptible(&vhci->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 *vhci,
 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 *) vhci->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 *vhci,
 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         vhci->hdev->stat.byte_tx += len;
 165
 166         switch (bt_cb(skb)->pkt_type) {
 167         case HCI_COMMAND_PKT:
 168                 vhci->hdev->stat.cmd_tx++;
 169                 break;
 170
 171         case HCI_ACLDATA_PKT:
 172                 vhci->hdev->stat.acl_tx++;
 173                 break;
 174
 175         case HCI_SCODATA_PKT:
 176                 vhci->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, char __user * buf, size_t count, loff_t *pos)
 189 {
 190         DECLARE_WAITQUEUE(wait, current);
 191         struct vhci_data *vhci = file->private_data;
 192         struct sk_buff *skb;
 193         ssize_t ret = 0;
 194
 195         add_wait_queue(&vhci->read_wait, &wait);
 196         while (count) {
 197                 set_current_state(TASK_INTERRUPTIBLE);
 198
 199                 skb = skb_dequeue(&vhci->readq);
 200                 if (!skb) {
 201                         if (file->f_flags & O_NONBLOCK) {
 202                                 ret = -EAGAIN;
 203                                 break;
 204                         }
 205
 206                         if (signal_pending(current)) {
 207                                 ret = -ERESTARTSYS;
 208                                 break;
 209                         }
 210
 211                         schedule();
 212                         continue;
 213                 }
 214
 215                 if (access_ok(VERIFY_WRITE, buf, count))
 216                         ret = vhci_put_user(vhci, skb, buf, count);
 217                 else
 218                         ret = -EFAULT;
 219
 220                 kfree_skb(skb);
 221                 break;
 222         }
 223         set_current_state(TASK_RUNNING);
 224         remove_wait_queue(&vhci->read_wait, &wait);
 225
 226         return ret;
 227 }
 228
 229 static ssize_t vhci_write(struct file *file,
 230                         const char __user *buf, size_t count, loff_t *pos)
 231 {
 232         struct vhci_data *vhci = file->private_data;
 233
 234         if (!access_ok(VERIFY_READ, buf, count))
 235                 return -EFAULT;
 236
 237         return vhci_get_user(vhci, buf, count);
 238 }
 239
 240 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 241 {
 242         struct vhci_data *vhci = file->private_data;
 243
 244         poll_wait(file, &vhci->read_wait, wait);
 245
 246         if (!skb_queue_empty(&vhci->readq))
 247                 return POLLIN | POLLRDNORM;
 248
 249         return POLLOUT | POLLWRNORM;
 250 }
 251
 252 static int vhci_ioctl(struct inode *inode, struct file *file,
 253                                         unsigned int cmd, unsigned long arg)
 254 {
 255         return -EINVAL;
 256 }
 257
 258 static int vhci_open(struct inode *inode, struct file *file)
 259 {
 260         struct vhci_data *vhci;
 261         struct hci_dev *hdev;
 262
 263         vhci = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 264         if (!vhci)
 265                 return -ENOMEM;
 266
 267         skb_queue_head_init(&vhci->readq);
 268         init_waitqueue_head(&vhci->read_wait);
 269
 270         hdev = hci_alloc_dev();
 271         if (!hdev) {
 272                 kfree(vhci);
 273                 return -ENOMEM;
 274         }
 275
 276         vhci->hdev = hdev;
 277
 278         hdev->type = HCI_VHCI;
 279         hdev->driver_data = vhci;
 280
 281         hdev->open     = vhci_open_dev;
 282         hdev->close    = vhci_close_dev;
 283         hdev->flush    = vhci_flush;
 284         hdev->send     = vhci_send_frame;
 285         hdev->destruct = vhci_destruct;
 286
 287         hdev->owner = THIS_MODULE;
 288
 289         if (hci_register_dev(hdev) < 0) {
 290                 BT_ERR("Can't register HCI device");
 291                 kfree(vhci);
 292                 hci_free_dev(hdev);
 293                 return -EBUSY;
 294         }
 295
 296         file->private_data = vhci;
 297
 298         return nonseekable_open(inode, file);
 299 }
 300
 301 static int vhci_release(struct inode *inode, struct file *file)
 302 {
 303         struct vhci_data *vhci = file->private_data;
 304         struct hci_dev *hdev = vhci->hdev;
 305
 306         if (hci_unregister_dev(hdev) < 0) {
 307                 BT_ERR("Can't unregister HCI device %s", hdev->name);
 308         }
 309
 310         hci_free_dev(hdev);
 311
 312         file->private_data = NULL;
 313
 314         return 0;
 315 }
 316
 317 static int vhci_fasync(int fd, struct file *file, int on)
 318 {
 319         struct vhci_data *vhci = file->private_data;
 320         int err;
 321
 322         err = fasync_helper(fd, file, on, &vhci->fasync);
 323         if (err < 0)
 324                 return err;
 325
 326         if (on)
 327                 vhci->flags |= VHCI_FASYNC;
 328         else
 329                 vhci->flags &= ~VHCI_FASYNC;
 330
 331         return 0;
 332 }
 333
 334 static struct file_operations vhci_fops = {
 335         .owner          = THIS_MODULE,
 336         .llseek         = vhci_llseek,
 337         .read           = vhci_read,
 338         .write          = vhci_write,
 339         .poll           = vhci_poll,
 340         .ioctl          = vhci_ioctl,
 341         .open           = vhci_open,
 342         .release        = vhci_release,
 343         .fasync         = vhci_fasync,
 344 };
 345
 346 static struct miscdevice vhci_miscdev= {
 347         .name           = "vhci",
 348         .fops           = &vhci_fops,
 349 };
 350
 351 static int __init vhci_init(void)
 352 {
 353         BT_INFO("Virtual HCI driver ver %s", VERSION);
 354
 355         vhci_miscdev.minor = minor;
 356
 357         if (misc_register(&vhci_miscdev) < 0) {
 358                 BT_ERR("Can't register misc device with minor %d", minor);
 359                 return -EIO;
 360         }
 361
 362         return 0;
 363 }
 364
 365 static void __exit vhci_exit(void)
 366 {
 367         if (misc_deregister(&vhci_miscdev) < 0)
 368                 BT_ERR("Can't unregister misc device with minor %d", minor);
 369 }
 370
 371 module_init(vhci_init);
 372 module_exit(vhci_exit);
 373
 374 module_param(minor, int, 0444);
 375 MODULE_PARM_DESC(minor, "Miscellaneous minor device number");
 376
 377 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>");
 378 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 379 MODULE_VERSION(VERSION);
 380 MODULE_LICENSE("GPL");