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