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