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 struct iovec *iov,
 145                                     unsigned long count)
 146 {
 147         size_t len = iov_length(iov, count);
 148         struct sk_buff *skb;
 149         __u8 pkt_type, dev_type;
 150         unsigned long i;
 151         int ret;
 152
 153         if (len < 2 || len > HCI_MAX_FRAME_SIZE)
 154                 return -EINVAL;
 155
 156         skb = bt_skb_alloc(len, GFP_KERNEL);
 157         if (!skb)
 158                 return -ENOMEM;
 159
 160         for (i = 0; i < count; i++) {
 161                 if (copy_from_user(skb_put(skb, iov[i].iov_len),
 162                                    iov[i].iov_base, iov[i].iov_len)) {
 163                         kfree_skb(skb);
 164                         return -EFAULT;
 165                 }
 166         }
 167
 168         pkt_type = *((__u8 *) skb->data);
 169         skb_pull(skb, 1);
 170
 171         switch (pkt_type) {
 172         case HCI_EVENT_PKT:
 173         case HCI_ACLDATA_PKT:
 174         case HCI_SCODATA_PKT:
 175                 if (!data->hdev) {
 176                         kfree_skb(skb);
 177                         return -ENODEV;
 178                 }
 179
 180                 bt_cb(skb)->pkt_type = pkt_type;
 181
 182                 ret = hci_recv_frame(data->hdev, skb);
 183                 break;
 184
 185         case HCI_VENDOR_PKT:
 186                 if (data->hdev) {
 187                         kfree_skb(skb);
 188                         return -EBADFD;
 189                 }
 190
 191                 cancel_delayed_work_sync(&data->open_timeout);
 192
 193                 dev_type = *((__u8 *) skb->data);
 194                 skb_pull(skb, 1);
 195
 196                 if (skb->len > 0) {
 197                         kfree_skb(skb);
 198                         return -EINVAL;
 199                 }
 200
 201                 kfree_skb(skb);
 202
 203                 if (dev_type != HCI_BREDR && dev_type != HCI_AMP)
 204                         return -EINVAL;
 205
 206                 ret = vhci_create_device(data, dev_type);
 207                 break;
 208
 209         default:
 210                 kfree_skb(skb);
 211                 return -EINVAL;
 212         }
 213
 214         return (ret < 0) ? ret : len;
 215 }
 216
 217 static inline ssize_t vhci_put_user(struct vhci_data *data,
 218                                     struct sk_buff *skb,
 219                                     char __user *buf, int count)
 220 {
 221         char __user *ptr = buf;
 222         int len;
 223
 224         len = min_t(unsigned int, skb->len, count);
 225
 226         if (copy_to_user(ptr, skb->data, len))
 227                 return -EFAULT;
 228
 229         if (!data->hdev)
 230                 return len;
 231
 232         data->hdev->stat.byte_tx += len;
 233
 234         switch (bt_cb(skb)->pkt_type) {
 235         case HCI_COMMAND_PKT:
 236                 data->hdev->stat.cmd_tx++;
 237                 break;
 238         case HCI_ACLDATA_PKT:
 239                 data->hdev->stat.acl_tx++;
 240                 break;
 241         case HCI_SCODATA_PKT:
 242                 data->hdev->stat.sco_tx++;
 243                 break;
 244         }
 245
 246         return len;
 247 }
 248
 249 static ssize_t vhci_read(struct file *file,
 250                          char __user *buf, size_t count, loff_t *pos)
 251 {
 252         struct vhci_data *data = file->private_data;
 253         struct sk_buff *skb;
 254         ssize_t ret = 0;
 255
 256         while (count) {
 257                 skb = skb_dequeue(&data->readq);
 258                 if (skb) {
 259                         ret = vhci_put_user(data, skb, buf, count);
 260                         if (ret < 0)
 261                                 skb_queue_head(&data->readq, skb);
 262                         else
 263                                 kfree_skb(skb);
 264                         break;
 265                 }
 266
 267                 if (file->f_flags & O_NONBLOCK) {
 268                         ret = -EAGAIN;
 269                         break;
 270                 }
 271
 272                 ret = wait_event_interruptible(data->read_wait,
 273                                                !skb_queue_empty(&data->readq));
 274                 if (ret < 0)
 275                         break;
 276         }
 277
 278         return ret;
 279 }
 280
 281 static ssize_t vhci_write(struct kiocb *iocb, const struct iovec *iov,
 282                           unsigned long count, loff_t pos)
 283 {
 284         struct file *file = iocb->ki_filp;
 285         struct vhci_data *data = file->private_data;
 286
 287         return vhci_get_user(data, iov, count);
 288 }
 289
 290 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 291 {
 292         struct vhci_data *data = file->private_data;
 293
 294         poll_wait(file, &data->read_wait, wait);
 295
 296         if (!skb_queue_empty(&data->readq))
 297                 return POLLIN | POLLRDNORM;
 298
 299         return POLLOUT | POLLWRNORM;
 300 }
 301
 302 static void vhci_open_timeout(struct work_struct *work)
 303 {
 304         struct vhci_data *data = container_of(work, struct vhci_data,
 305                                               open_timeout.work);
 306
 307         vhci_create_device(data, amp ? HCI_AMP : HCI_BREDR);
 308 }
 309
 310 static int vhci_open(struct inode *inode, struct file *file)
 311 {
 312         struct vhci_data *data;
 313
 314         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 315         if (!data)
 316                 return -ENOMEM;
 317
 318         skb_queue_head_init(&data->readq);
 319         init_waitqueue_head(&data->read_wait);
 320
 321         INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
 322
 323         file->private_data = data;
 324         nonseekable_open(inode, file);
 325
 326         schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
 327
 328         return 0;
 329 }
 330
 331 static int vhci_release(struct inode *inode, struct file *file)
 332 {
 333         struct vhci_data *data = file->private_data;
 334         struct hci_dev *hdev = data->hdev;
 335
 336         cancel_delayed_work_sync(&data->open_timeout);
 337
 338         if (hdev) {
 339                 hci_unregister_dev(hdev);
 340                 hci_free_dev(hdev);
 341         }
 342
 343         file->private_data = NULL;
 344         kfree(data);
 345
 346         return 0;
 347 }
 348
 349 static const struct file_operations vhci_fops = {
 350         .owner          = THIS_MODULE,
 351         .read           = vhci_read,
 352         .aio_write      = vhci_write,
 353         .poll           = vhci_poll,
 354         .open           = vhci_open,
 355         .release        = vhci_release,
 356         .llseek         = no_llseek,
 357 };
 358
 359 static struct miscdevice vhci_miscdev= {
 360         .name   = "vhci",
 361         .fops   = &vhci_fops,
 362         .minor  = MISC_DYNAMIC_MINOR,
 363 };
 364
 365 static int __init vhci_init(void)
 366 {
 367         BT_INFO("Virtual HCI driver ver %s", VERSION);
 368
 369         return misc_register(&vhci_miscdev);
 370 }
 371
 372 static void __exit vhci_exit(void)
 373 {
 374         misc_deregister(&vhci_miscdev);
 375 }
 376
 377 module_init(vhci_init);
 378 module_exit(vhci_exit);
 379
 380 module_param(amp, bool, 0644);
 381 MODULE_PARM_DESC(amp, "Create AMP controller device");
 382
 383 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 384 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 385 MODULE_VERSION(VERSION);
 386 MODULE_LICENSE("GPL");
 387 MODULE_ALIAS("devname:vhci");