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 #include <asm/unaligned.h>
  28
  29 #include <linux/kernel.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.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 "1.4"
  44
  45 static bool amp;
  46
  47 struct vhci_data {
  48         struct hci_dev *hdev;
  49
  50         wait_queue_head_t read_wait;
  51         struct sk_buff_head readq;
  52
  53         struct delayed_work open_timeout;
  54 };
  55
  56 static int vhci_open_dev(struct hci_dev *hdev)
  57 {
  58         set_bit(HCI_RUNNING, &hdev->flags);
  59
  60         return 0;
  61 }
  62
  63 static int vhci_close_dev(struct hci_dev *hdev)
  64 {
  65         struct vhci_data *data = hci_get_drvdata(hdev);
  66
  67         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  68                 return 0;
  69
  70         skb_queue_purge(&data->readq);
  71
  72         return 0;
  73 }
  74
  75 static int vhci_flush(struct hci_dev *hdev)
  76 {
  77         struct vhci_data *data = hci_get_drvdata(hdev);
  78
  79         skb_queue_purge(&data->readq);
  80
  81         return 0;
  82 }
  83
  84 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
  85 {
  86         struct vhci_data *data = hci_get_drvdata(hdev);
  87
  88         if (!test_bit(HCI_RUNNING, &hdev->flags))
  89                 return -EBUSY;
  90
  91         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
  92         skb_queue_tail(&data->readq, skb);
  93
  94         wake_up_interruptible(&data->read_wait);
  95         return 0;
  96 }
  97
  98 static int vhci_create_device(struct vhci_data *data, __u8 dev_type)
  99 {
 100         struct hci_dev *hdev;
 101         struct sk_buff *skb;
 102
 103         skb = bt_skb_alloc(4, GFP_KERNEL);
 104         if (!skb)
 105                 return -ENOMEM;
 106
 107         hdev = hci_alloc_dev();
 108         if (!hdev) {
 109                 kfree_skb(skb);
 110                 return -ENOMEM;
 111         }
 112
 113         data->hdev = hdev;
 114
 115         hdev->bus = HCI_VIRTUAL;
 116         hdev->dev_type = dev_type;
 117         hci_set_drvdata(hdev, data);
 118
 119         hdev->open  = vhci_open_dev;
 120         hdev->close = vhci_close_dev;
 121         hdev->flush = vhci_flush;
 122         hdev->send  = vhci_send_frame;
 123
 124         if (hci_register_dev(hdev) < 0) {
 125                 BT_ERR("Can't register HCI device");
 126                 hci_free_dev(hdev);
 127                 data->hdev = NULL;
 128                 kfree_skb(skb);
 129                 return -EBUSY;
 130         }
 131
 132         bt_cb(skb)->pkt_type = HCI_VENDOR_PKT;
 133
 134         *skb_put(skb, 1) = 0xff;
 135         *skb_put(skb, 1) = dev_type;
 136         put_unaligned_le16(hdev->id, skb_put(skb, 2));
 137         skb_queue_tail(&data->readq, skb);
 138
 139         wake_up_interruptible(&data->read_wait);
 140         return 0;
 141 }
 142
 143 static inline ssize_t vhci_get_user(struct vhci_data *data,
 144                                     const char __user *buf, size_t count)
 145 {
 146         struct sk_buff *skb;
 147         __u8 pkt_type, dev_type;
 148         int ret;
 149
 150         if (count < 2 || count > HCI_MAX_FRAME_SIZE)
 151                 return -EINVAL;
 152
 153         skb = bt_skb_alloc(count, GFP_KERNEL);
 154         if (!skb)
 155                 return -ENOMEM;
 156
 157         if (copy_from_user(skb_put(skb, count), buf, count)) {
 158                 kfree_skb(skb);
 159                 return -EFAULT;
 160         }
 161
 162         pkt_type = *((__u8 *) skb->data);
 163         skb_pull(skb, 1);
 164
 165         switch (pkt_type) {
 166         case HCI_EVENT_PKT:
 167         case HCI_ACLDATA_PKT:
 168         case HCI_SCODATA_PKT:
 169                 if (!data->hdev) {
 170                         kfree_skb(skb);
 171                         return -ENODEV;
 172                 }
 173
 174                 bt_cb(skb)->pkt_type = pkt_type;
 175
 176                 ret = hci_recv_frame(data->hdev, skb);
 177                 break;
 178
 179         case HCI_VENDOR_PKT:
 180                 if (data->hdev) {
 181                         kfree_skb(skb);
 182                         return -EBADFD;
 183                 }
 184
 185                 cancel_delayed_work_sync(&data->open_timeout);
 186
 187                 dev_type = *((__u8 *) skb->data);
 188                 skb_pull(skb, 1);
 189
 190                 if (skb->len > 0) {
 191                         kfree_skb(skb);
 192                         return -EINVAL;
 193                 }
 194
 195                 kfree_skb(skb);
 196
 197                 if (dev_type != HCI_BREDR && dev_type != HCI_AMP)
 198                         return -EINVAL;
 199
 200                 ret = vhci_create_device(data, dev_type);
 201                 break;
 202
 203         default:
 204                 kfree_skb(skb);
 205                 return -EINVAL;
 206         }
 207
 208         return (ret < 0) ? ret : count;
 209 }
 210
 211 static inline ssize_t vhci_put_user(struct vhci_data *data,
 212                                     struct sk_buff *skb,
 213                                     char __user *buf, int count)
 214 {
 215         char __user *ptr = buf;
 216         int len;
 217
 218         len = min_t(unsigned int, skb->len, count);
 219
 220         if (copy_to_user(ptr, skb->data, len))
 221                 return -EFAULT;
 222
 223         if (!data->hdev)
 224                 return len;
 225
 226         data->hdev->stat.byte_tx += len;
 227
 228         switch (bt_cb(skb)->pkt_type) {
 229         case HCI_COMMAND_PKT:
 230                 data->hdev->stat.cmd_tx++;
 231                 break;
 232         case HCI_ACLDATA_PKT:
 233                 data->hdev->stat.acl_tx++;
 234                 break;
 235         case HCI_SCODATA_PKT:
 236                 data->hdev->stat.sco_tx++;
 237                 break;
 238         }
 239
 240         return len;
 241 }
 242
 243 static ssize_t vhci_read(struct file *file,
 244                          char __user *buf, size_t count, loff_t *pos)
 245 {
 246         struct vhci_data *data = file->private_data;
 247         struct sk_buff *skb;
 248         ssize_t ret = 0;
 249
 250         while (count) {
 251                 skb = skb_dequeue(&data->readq);
 252                 if (skb) {
 253                         ret = vhci_put_user(data, skb, buf, count);
 254                         if (ret < 0)
 255                                 skb_queue_head(&data->readq, skb);
 256                         else
 257                                 kfree_skb(skb);
 258                         break;
 259                 }
 260
 261                 if (file->f_flags & O_NONBLOCK) {
 262                         ret = -EAGAIN;
 263                         break;
 264                 }
 265
 266                 ret = wait_event_interruptible(data->read_wait,
 267                                                !skb_queue_empty(&data->readq));
 268                 if (ret < 0)
 269                         break;
 270         }
 271
 272         return ret;
 273 }
 274
 275 static ssize_t vhci_write(struct file *file,
 276                           const char __user *buf, size_t count, loff_t *pos)
 277 {
 278         struct vhci_data *data = file->private_data;
 279
 280         return vhci_get_user(data, buf, count);
 281 }
 282
 283 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 284 {
 285         struct vhci_data *data = file->private_data;
 286
 287         poll_wait(file, &data->read_wait, wait);
 288
 289         if (!skb_queue_empty(&data->readq))
 290                 return POLLIN | POLLRDNORM;
 291
 292         return POLLOUT | POLLWRNORM;
 293 }
 294
 295 static void vhci_open_timeout(struct work_struct *work)
 296 {
 297         struct vhci_data *data = container_of(work, struct vhci_data,
 298                                               open_timeout.work);
 299
 300         vhci_create_device(data, amp ? HCI_AMP : HCI_BREDR);
 301 }
 302
 303 static int vhci_open(struct inode *inode, struct file *file)
 304 {
 305         struct vhci_data *data;
 306
 307         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 308         if (!data)
 309                 return -ENOMEM;
 310
 311         skb_queue_head_init(&data->readq);
 312         init_waitqueue_head(&data->read_wait);
 313
 314         INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
 315
 316         file->private_data = data;
 317         nonseekable_open(inode, file);
 318
 319         schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
 320
 321         return 0;
 322 }
 323
 324 static int vhci_release(struct inode *inode, struct file *file)
 325 {
 326         struct vhci_data *data = file->private_data;
 327         struct hci_dev *hdev = data->hdev;
 328
 329         cancel_delayed_work_sync(&data->open_timeout);
 330
 331         if (hdev) {
 332                 hci_unregister_dev(hdev);
 333                 hci_free_dev(hdev);
 334         }
 335
 336         file->private_data = NULL;
 337         kfree(data);
 338
 339         return 0;
 340 }
 341
 342 static const struct file_operations vhci_fops = {
 343         .owner          = THIS_MODULE,
 344         .read           = vhci_read,
 345         .write          = vhci_write,
 346         .poll           = vhci_poll,
 347         .open           = vhci_open,
 348         .release        = vhci_release,
 349         .llseek         = no_llseek,
 350 };
 351
 352 static struct miscdevice vhci_miscdev= {
 353         .name   = "vhci",
 354         .fops   = &vhci_fops,
 355         .minor  = MISC_DYNAMIC_MINOR,
 356 };
 357
 358 static int __init vhci_init(void)
 359 {
 360         BT_INFO("Virtual HCI driver ver %s", VERSION);
 361
 362         return misc_register(&vhci_miscdev);
 363 }
 364
 365 static void __exit vhci_exit(void)
 366 {
 367         misc_deregister(&vhci_miscdev);
 368 }
 369
 370 module_init(vhci_init);
 371 module_exit(vhci_exit);
 372
 373 module_param(amp, bool, 0644);
 374 MODULE_PARM_DESC(amp, "Create AMP controller device");
 375
 376 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 377 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 378 MODULE_VERSION(VERSION);
 379 MODULE_LICENSE("GPL");
 380 MODULE_ALIAS("devname:vhci");