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         skb_queue_tail(&data->readq, skb);
  86
  87         wake_up_interruptible(&data->read_wait);
  88         return 0;
  89 }
  90
  91 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
  92 {
  93         struct hci_dev *hdev;
  94         struct sk_buff *skb;
  95         __u8 dev_type;
  96
  97         if (data->hdev)
  98                 return -EBADFD;
  99
 100         /* bits 0-1 are dev_type (BR/EDR or AMP) */
 101         dev_type = opcode & 0x03;
 102
 103         if (dev_type != HCI_BREDR && dev_type != HCI_AMP)
 104                 return -EINVAL;
 105
 106         /* bits 2-5 are reserved (must be zero) */
 107         if (opcode & 0x3c)
 108                 return -EINVAL;
 109
 110         skb = bt_skb_alloc(4, GFP_KERNEL);
 111         if (!skb)
 112                 return -ENOMEM;
 113
 114         hdev = hci_alloc_dev();
 115         if (!hdev) {
 116                 kfree_skb(skb);
 117                 return -ENOMEM;
 118         }
 119
 120         data->hdev = hdev;
 121
 122         hdev->bus = HCI_VIRTUAL;
 123         hdev->dev_type = dev_type;
 124         hci_set_drvdata(hdev, data);
 125
 126         hdev->open  = vhci_open_dev;
 127         hdev->close = vhci_close_dev;
 128         hdev->flush = vhci_flush;
 129         hdev->send  = vhci_send_frame;
 130
 131         /* bit 6 is for external configuration */
 132         if (opcode & 0x40)
 133                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 134
 135         /* bit 7 is for raw device */
 136         if (opcode & 0x80)
 137                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 138
 139         if (hci_register_dev(hdev) < 0) {
 140                 BT_ERR("Can't register HCI device");
 141                 hci_free_dev(hdev);
 142                 data->hdev = NULL;
 143                 kfree_skb(skb);
 144                 return -EBUSY;
 145         }
 146
 147         hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
 148
 149         *skb_put(skb, 1) = 0xff;
 150         *skb_put(skb, 1) = opcode;
 151         put_unaligned_le16(hdev->id, skb_put(skb, 2));
 152         skb_queue_tail(&data->readq, skb);
 153
 154         wake_up_interruptible(&data->read_wait);
 155         return 0;
 156 }
 157
 158 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
 159 {
 160         int err;
 161
 162         mutex_lock(&data->open_mutex);
 163         err = __vhci_create_device(data, opcode);
 164         mutex_unlock(&data->open_mutex);
 165
 166         return err;
 167 }
 168
 169 static inline ssize_t vhci_get_user(struct vhci_data *data,
 170                                     struct iov_iter *from)
 171 {
 172         size_t len = iov_iter_count(from);
 173         struct sk_buff *skb;
 174         __u8 pkt_type, opcode;
 175         int ret;
 176
 177         if (len < 2 || len > HCI_MAX_FRAME_SIZE)
 178                 return -EINVAL;
 179
 180         skb = bt_skb_alloc(len, GFP_KERNEL);
 181         if (!skb)
 182                 return -ENOMEM;
 183
 184         if (copy_from_iter(skb_put(skb, len), len, from) != len) {
 185                 kfree_skb(skb);
 186                 return -EFAULT;
 187         }
 188
 189         pkt_type = *((__u8 *) skb->data);
 190         skb_pull(skb, 1);
 191
 192         switch (pkt_type) {
 193         case HCI_EVENT_PKT:
 194         case HCI_ACLDATA_PKT:
 195         case HCI_SCODATA_PKT:
 196                 if (!data->hdev) {
 197                         kfree_skb(skb);
 198                         return -ENODEV;
 199                 }
 200
 201                 hci_skb_pkt_type(skb) = pkt_type;
 202
 203                 ret = hci_recv_frame(data->hdev, skb);
 204                 break;
 205
 206         case HCI_VENDOR_PKT:
 207                 cancel_delayed_work_sync(&data->open_timeout);
 208
 209                 opcode = *((__u8 *) skb->data);
 210                 skb_pull(skb, 1);
 211
 212                 if (skb->len > 0) {
 213                         kfree_skb(skb);
 214                         return -EINVAL;
 215                 }
 216
 217                 kfree_skb(skb);
 218
 219                 ret = vhci_create_device(data, opcode);
 220                 break;
 221
 222         default:
 223                 kfree_skb(skb);
 224                 return -EINVAL;
 225         }
 226
 227         return (ret < 0) ? ret : len;
 228 }
 229
 230 static inline ssize_t vhci_put_user(struct vhci_data *data,
 231                                     struct sk_buff *skb,
 232                                     char __user *buf, int count)
 233 {
 234         char __user *ptr = buf;
 235         int len;
 236
 237         len = min_t(unsigned int, skb->len, count);
 238
 239         if (copy_to_user(ptr, skb->data, len))
 240                 return -EFAULT;
 241
 242         if (!data->hdev)
 243                 return len;
 244
 245         data->hdev->stat.byte_tx += len;
 246
 247         switch (hci_skb_pkt_type(skb)) {
 248         case HCI_COMMAND_PKT:
 249                 data->hdev->stat.cmd_tx++;
 250                 break;
 251         case HCI_ACLDATA_PKT:
 252                 data->hdev->stat.acl_tx++;
 253                 break;
 254         case HCI_SCODATA_PKT:
 255                 data->hdev->stat.sco_tx++;
 256                 break;
 257         }
 258
 259         return len;
 260 }
 261
 262 static ssize_t vhci_read(struct file *file,
 263                          char __user *buf, size_t count, loff_t *pos)
 264 {
 265         struct vhci_data *data = file->private_data;
 266         struct sk_buff *skb;
 267         ssize_t ret = 0;
 268
 269         while (count) {
 270                 skb = skb_dequeue(&data->readq);
 271                 if (skb) {
 272                         ret = vhci_put_user(data, skb, buf, count);
 273                         if (ret < 0)
 274                                 skb_queue_head(&data->readq, skb);
 275                         else
 276                                 kfree_skb(skb);
 277                         break;
 278                 }
 279
 280                 if (file->f_flags & O_NONBLOCK) {
 281                         ret = -EAGAIN;
 282                         break;
 283                 }
 284
 285                 ret = wait_event_interruptible(data->read_wait,
 286                                                !skb_queue_empty(&data->readq));
 287                 if (ret < 0)
 288                         break;
 289         }
 290
 291         return ret;
 292 }
 293
 294 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
 295 {
 296         struct file *file = iocb->ki_filp;
 297         struct vhci_data *data = file->private_data;
 298
 299         return vhci_get_user(data, from);
 300 }
 301
 302 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 303 {
 304         struct vhci_data *data = file->private_data;
 305
 306         poll_wait(file, &data->read_wait, wait);
 307
 308         if (!skb_queue_empty(&data->readq))
 309                 return POLLIN | POLLRDNORM;
 310
 311         return POLLOUT | POLLWRNORM;
 312 }
 313
 314 static void vhci_open_timeout(struct work_struct *work)
 315 {
 316         struct vhci_data *data = container_of(work, struct vhci_data,
 317                                               open_timeout.work);
 318
 319         vhci_create_device(data, amp ? HCI_AMP : HCI_BREDR);
 320 }
 321
 322 static int vhci_open(struct inode *inode, struct file *file)
 323 {
 324         struct vhci_data *data;
 325
 326         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 327         if (!data)
 328                 return -ENOMEM;
 329
 330         skb_queue_head_init(&data->readq);
 331         init_waitqueue_head(&data->read_wait);
 332
 333         mutex_init(&data->open_mutex);
 334         INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
 335
 336         file->private_data = data;
 337         nonseekable_open(inode, file);
 338
 339         schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
 340
 341         return 0;
 342 }
 343
 344 static int vhci_release(struct inode *inode, struct file *file)
 345 {
 346         struct vhci_data *data = file->private_data;
 347         struct hci_dev *hdev;
 348
 349         cancel_delayed_work_sync(&data->open_timeout);
 350
 351         hdev = data->hdev;
 352
 353         if (hdev) {
 354                 hci_unregister_dev(hdev);
 355                 hci_free_dev(hdev);
 356         }
 357
 358         skb_queue_purge(&data->readq);
 359         file->private_data = NULL;
 360         kfree(data);
 361
 362         return 0;
 363 }
 364
 365 static const struct file_operations vhci_fops = {
 366         .owner          = THIS_MODULE,
 367         .read           = vhci_read,
 368         .write_iter     = vhci_write,
 369         .poll           = vhci_poll,
 370         .open           = vhci_open,
 371         .release        = vhci_release,
 372         .llseek         = no_llseek,
 373 };
 374
 375 static struct miscdevice vhci_miscdev = {
 376         .name   = "vhci",
 377         .fops   = &vhci_fops,
 378         .minor  = VHCI_MINOR,
 379 };
 380
 381 static int __init vhci_init(void)
 382 {
 383         BT_INFO("Virtual HCI driver ver %s", VERSION);
 384
 385         return misc_register(&vhci_miscdev);
 386 }
 387
 388 static void __exit vhci_exit(void)
 389 {
 390         misc_deregister(&vhci_miscdev);
 391 }
 392
 393 module_init(vhci_init);
 394 module_exit(vhci_exit);
 395
 396 module_param(amp, bool, 0644);
 397 MODULE_PARM_DESC(amp, "Create AMP controller device");
 398
 399 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 400 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 401 MODULE_VERSION(VERSION);
 402 MODULE_LICENSE("GPL");
 403 MODULE_ALIAS("devname:vhci");
 404 MODULE_ALIAS_MISCDEV(VHCI_MINOR);