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 "1.5"
  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 mutex open_mutex;
  54         struct delayed_work open_timeout;
  55 };
  56
  57 static int vhci_open_dev(struct hci_dev *hdev)
  58 {
  59         return 0;
  60 }
  61
  62 static int vhci_close_dev(struct hci_dev *hdev)
  63 {
  64         struct vhci_data *data = hci_get_drvdata(hdev);
  65
  66         skb_queue_purge(&data->readq);
  67
  68         return 0;
  69 }
  70
  71 static int vhci_flush(struct hci_dev *hdev)
  72 {
  73         struct vhci_data *data = hci_get_drvdata(hdev);
  74
  75         skb_queue_purge(&data->readq);
  76
  77         return 0;
  78 }
  79
  80 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
  81 {
  82         struct vhci_data *data = hci_get_drvdata(hdev);
  83
  84         memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
  85
  86         mutex_lock(&data->open_mutex);
  87         skb_queue_tail(&data->readq, skb);
  88         mutex_unlock(&data->open_mutex);
  89
  90         wake_up_interruptible(&data->read_wait);
  91         return 0;
  92 }
  93
  94 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
  95 {
  96         struct hci_dev *hdev;
  97         struct sk_buff *skb;
  98         __u8 dev_type;
  99
 100         if (data->hdev)
 101                 return -EBADFD;
 102
 103         /* bits 0-1 are dev_type (Primary or AMP) */
 104         dev_type = opcode & 0x03;
 105
 106         if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
 107                 return -EINVAL;
 108
 109         /* bits 2-5 are reserved (must be zero) */
 110         if (opcode & 0x3c)
 111                 return -EINVAL;
 112
 113         skb = bt_skb_alloc(4, GFP_KERNEL);
 114         if (!skb)
 115                 return -ENOMEM;
 116
 117         hdev = hci_alloc_dev();
 118         if (!hdev) {
 119                 kfree_skb(skb);
 120                 return -ENOMEM;
 121         }
 122
 123         data->hdev = hdev;
 124
 125         hdev->bus = HCI_VIRTUAL;
 126         hdev->dev_type = dev_type;
 127         hci_set_drvdata(hdev, data);
 128
 129         hdev->open  = vhci_open_dev;
 130         hdev->close = vhci_close_dev;
 131         hdev->flush = vhci_flush;
 132         hdev->send  = vhci_send_frame;
 133
 134         /* bit 6 is for external configuration */
 135         if (opcode & 0x40)
 136                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 137
 138         /* bit 7 is for raw device */
 139         if (opcode & 0x80)
 140                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 141
 142         if (hci_register_dev(hdev) < 0) {
 143                 BT_ERR("Can't register HCI device");
 144                 hci_free_dev(hdev);
 145                 data->hdev = NULL;
 146                 kfree_skb(skb);
 147                 return -EBUSY;
 148         }
 149
 150         hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
 151
 152         skb_put_u8(skb, 0xff);
 153         skb_put_u8(skb, opcode);
 154         put_unaligned_le16(hdev->id, skb_put(skb, 2));
 155         skb_queue_tail(&data->readq, skb);
 156
 157         wake_up_interruptible(&data->read_wait);
 158         return 0;
 159 }
 160
 161 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
 162 {
 163         int err;
 164
 165         mutex_lock(&data->open_mutex);
 166         err = __vhci_create_device(data, opcode);
 167         mutex_unlock(&data->open_mutex);
 168
 169         return err;
 170 }
 171
 172 static inline ssize_t vhci_get_user(struct vhci_data *data,
 173                                     struct iov_iter *from)
 174 {
 175         size_t len = iov_iter_count(from);
 176         struct sk_buff *skb;
 177         __u8 pkt_type, opcode;
 178         int ret;
 179
 180         if (len < 2 || len > HCI_MAX_FRAME_SIZE)
 181                 return -EINVAL;
 182
 183         skb = bt_skb_alloc(len, GFP_KERNEL);
 184         if (!skb)
 185                 return -ENOMEM;
 186
 187         if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
 188                 kfree_skb(skb);
 189                 return -EFAULT;
 190         }
 191
 192         pkt_type = *((__u8 *) skb->data);
 193         skb_pull(skb, 1);
 194
 195         switch (pkt_type) {
 196         case HCI_EVENT_PKT:
 197         case HCI_ACLDATA_PKT:
 198         case HCI_SCODATA_PKT:
 199                 if (!data->hdev) {
 200                         kfree_skb(skb);
 201                         return -ENODEV;
 202                 }
 203
 204                 hci_skb_pkt_type(skb) = pkt_type;
 205
 206                 ret = hci_recv_frame(data->hdev, skb);
 207                 break;
 208
 209         case HCI_VENDOR_PKT:
 210                 cancel_delayed_work_sync(&data->open_timeout);
 211
 212                 opcode = *((__u8 *) skb->data);
 213                 skb_pull(skb, 1);
 214
 215                 if (skb->len > 0) {
 216                         kfree_skb(skb);
 217                         return -EINVAL;
 218                 }
 219
 220                 kfree_skb(skb);
 221
 222                 ret = vhci_create_device(data, opcode);
 223                 break;
 224
 225         default:
 226                 kfree_skb(skb);
 227                 return -EINVAL;
 228         }
 229
 230         return (ret < 0) ? ret : len;
 231 }
 232
 233 static inline ssize_t vhci_put_user(struct vhci_data *data,
 234                                     struct sk_buff *skb,
 235                                     char __user *buf, int count)
 236 {
 237         char __user *ptr = buf;
 238         int len;
 239
 240         len = min_t(unsigned int, skb->len, count);
 241
 242         if (copy_to_user(ptr, skb->data, len))
 243                 return -EFAULT;
 244
 245         if (!data->hdev)
 246                 return len;
 247
 248         data->hdev->stat.byte_tx += len;
 249
 250         switch (hci_skb_pkt_type(skb)) {
 251         case HCI_COMMAND_PKT:
 252                 data->hdev->stat.cmd_tx++;
 253                 break;
 254         case HCI_ACLDATA_PKT:
 255                 data->hdev->stat.acl_tx++;
 256                 break;
 257         case HCI_SCODATA_PKT:
 258                 data->hdev->stat.sco_tx++;
 259                 break;
 260         }
 261
 262         return len;
 263 }
 264
 265 static ssize_t vhci_read(struct file *file,
 266                          char __user *buf, size_t count, loff_t *pos)
 267 {
 268         struct vhci_data *data = file->private_data;
 269         struct sk_buff *skb;
 270         ssize_t ret = 0;
 271
 272         while (count) {
 273                 skb = skb_dequeue(&data->readq);
 274                 if (skb) {
 275                         ret = vhci_put_user(data, skb, buf, count);
 276                         if (ret < 0)
 277                                 skb_queue_head(&data->readq, skb);
 278                         else
 279                                 kfree_skb(skb);
 280                         break;
 281                 }
 282
 283                 if (file->f_flags & O_NONBLOCK) {
 284                         ret = -EAGAIN;
 285                         break;
 286                 }
 287
 288                 ret = wait_event_interruptible(data->read_wait,
 289                                                !skb_queue_empty(&data->readq));
 290                 if (ret < 0)
 291                         break;
 292         }
 293
 294         return ret;
 295 }
 296
 297 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
 298 {
 299         struct file *file = iocb->ki_filp;
 300         struct vhci_data *data = file->private_data;
 301
 302         return vhci_get_user(data, from);
 303 }
 304
 305 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 306 {
 307         struct vhci_data *data = file->private_data;
 308
 309         poll_wait(file, &data->read_wait, wait);
 310
 311         if (!skb_queue_empty(&data->readq))
 312                 return POLLIN | POLLRDNORM;
 313
 314         return POLLOUT | POLLWRNORM;
 315 }
 316
 317 static void vhci_open_timeout(struct work_struct *work)
 318 {
 319         struct vhci_data *data = container_of(work, struct vhci_data,
 320                                               open_timeout.work);
 321
 322         vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY);
 323 }
 324
 325 static int vhci_open(struct inode *inode, struct file *file)
 326 {
 327         struct vhci_data *data;
 328
 329         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 330         if (!data)
 331                 return -ENOMEM;
 332
 333         skb_queue_head_init(&data->readq);
 334         init_waitqueue_head(&data->read_wait);
 335
 336         mutex_init(&data->open_mutex);
 337         INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
 338
 339         file->private_data = data;
 340         nonseekable_open(inode, file);
 341
 342         schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
 343
 344         return 0;
 345 }
 346
 347 static int vhci_release(struct inode *inode, struct file *file)
 348 {
 349         struct vhci_data *data = file->private_data;
 350         struct hci_dev *hdev;
 351
 352         cancel_delayed_work_sync(&data->open_timeout);
 353
 354         hdev = data->hdev;
 355
 356         if (hdev) {
 357                 hci_unregister_dev(hdev);
 358                 hci_free_dev(hdev);
 359         }
 360
 361         skb_queue_purge(&data->readq);
 362         file->private_data = NULL;
 363         kfree(data);
 364
 365         return 0;
 366 }
 367
 368 static const struct file_operations vhci_fops = {
 369         .owner          = THIS_MODULE,
 370         .read           = vhci_read,
 371         .write_iter     = vhci_write,
 372         .poll           = vhci_poll,
 373         .open           = vhci_open,
 374         .release        = vhci_release,
 375         .llseek         = no_llseek,
 376 };
 377
 378 static struct miscdevice vhci_miscdev = {
 379         .name   = "vhci",
 380         .fops   = &vhci_fops,
 381         .minor  = VHCI_MINOR,
 382 };
 383 module_misc_device(vhci_miscdev);
 384
 385 module_param(amp, bool, 0644);
 386 MODULE_PARM_DESC(amp, "Create AMP controller device");
 387
 388 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 389 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 390 MODULE_VERSION(VERSION);
 391 MODULE_LICENSE("GPL");
 392 MODULE_ALIAS("devname:vhci");
 393 MODULE_ALIAS_MISCDEV(VHCI_MINOR);