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
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/types.h>
  32 #include <linux/errno.h>
  33 #include <linux/sched.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/skbuff.h>
  37 #include <linux/miscdevice.h>
  38
  39 #include <net/bluetooth/bluetooth.h>
  40 #include <net/bluetooth/hci_core.h>
  41
  42 #define VERSION "1.3"
  43
  44 static int minor = MISC_DYNAMIC_MINOR;
  45
  46 struct vhci_data {
  47         struct hci_dev *hdev;
  48
  49         unsigned long flags;
  50
  51         wait_queue_head_t read_wait;
  52         struct sk_buff_head readq;
  53 };
  54
  55 static int vhci_open_dev(struct hci_dev *hdev)
  56 {
  57         set_bit(HCI_RUNNING, &hdev->flags);
  58
  59         return 0;
  60 }
  61
  62 static int vhci_close_dev(struct hci_dev *hdev)
  63 {
  64         struct vhci_data *data = hdev->driver_data;
  65
  66         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
  67                 return 0;
  68
  69         skb_queue_purge(&data->readq);
  70
  71         return 0;
  72 }
  73
  74 static int vhci_flush(struct hci_dev *hdev)
  75 {
  76         struct vhci_data *data = hdev->driver_data;
  77
  78         skb_queue_purge(&data->readq);
  79
  80         return 0;
  81 }
  82
  83 static int vhci_send_frame(struct sk_buff *skb)
  84 {
  85         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
  86         struct vhci_data *data;
  87
  88         if (!hdev) {
  89                 BT_ERR("Frame for unknown HCI device (hdev=NULL)");
  90                 return -ENODEV;
  91         }
  92
  93         if (!test_bit(HCI_RUNNING, &hdev->flags))
  94                 return -EBUSY;
  95
  96         data = hdev->driver_data;
  97
  98         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
  99         skb_queue_tail(&data->readq, skb);
 100
 101         wake_up_interruptible(&data->read_wait);
 102
 103         return 0;
 104 }
 105
 106 static void vhci_destruct(struct hci_dev *hdev)
 107 {
 108         kfree(hdev->driver_data);
 109 }
 110
 111 static inline ssize_t vhci_get_user(struct vhci_data *data,
 112                                         const char __user *buf, size_t count)
 113 {
 114         struct sk_buff *skb;
 115
 116         if (count > HCI_MAX_FRAME_SIZE)
 117                 return -EINVAL;
 118
 119         skb = bt_skb_alloc(count, GFP_KERNEL);
 120         if (!skb)
 121                 return -ENOMEM;
 122
 123         if (copy_from_user(skb_put(skb, count), buf, count)) {
 124                 kfree_skb(skb);
 125                 return -EFAULT;
 126         }
 127
 128         skb->dev = (void *) data->hdev;
 129         bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
 130         skb_pull(skb, 1);
 131
 132         hci_recv_frame(skb);
 133
 134         return count;
 135 }
 136
 137 static inline ssize_t vhci_put_user(struct vhci_data *data,
 138                         struct sk_buff *skb, char __user *buf, int count)
 139 {
 140         char __user *ptr = buf;
 141         int len, total = 0;
 142
 143         len = min_t(unsigned int, skb->len, count);
 144
 145         if (copy_to_user(ptr, skb->data, len))
 146                 return -EFAULT;
 147
 148         total += len;
 149
 150         data->hdev->stat.byte_tx += len;
 151
 152         switch (bt_cb(skb)->pkt_type) {
 153         case HCI_COMMAND_PKT:
 154                 data->hdev->stat.cmd_tx++;
 155                 break;
 156
 157         case HCI_ACLDATA_PKT:
 158                 data->hdev->stat.acl_tx++;
 159                 break;
 160
 161         case HCI_SCODATA_PKT:
 162                 data->hdev->stat.cmd_tx++;
 163                 break;
 164         };
 165
 166         return total;
 167 }
 168
 169 static ssize_t vhci_read(struct file *file,
 170                                 char __user *buf, size_t count, loff_t *pos)
 171 {
 172         struct vhci_data *data = file->private_data;
 173         struct sk_buff *skb;
 174         ssize_t ret = 0;
 175
 176         while (count) {
 177                 skb = skb_dequeue(&data->readq);
 178                 if (skb) {
 179                         ret = vhci_put_user(data, skb, buf, count);
 180                         if (ret < 0)
 181                                 skb_queue_head(&data->readq, skb);
 182                         else
 183                                 kfree_skb(skb);
 184                         break;
 185                 }
 186
 187                 if (file->f_flags & O_NONBLOCK) {
 188                         ret = -EAGAIN;
 189                         break;
 190                 }
 191
 192                 ret = wait_event_interruptible(data->read_wait,
 193                                         !skb_queue_empty(&data->readq));
 194                 if (ret < 0)
 195                         break;
 196         }
 197
 198         return ret;
 199 }
 200
 201 static ssize_t vhci_write(struct file *file,
 202                         const char __user *buf, size_t count, loff_t *pos)
 203 {
 204         struct vhci_data *data = file->private_data;
 205
 206         return vhci_get_user(data, buf, count);
 207 }
 208
 209 static unsigned int vhci_poll(struct file *file, poll_table *wait)
 210 {
 211         struct vhci_data *data = file->private_data;
 212
 213         poll_wait(file, &data->read_wait, wait);
 214
 215         if (!skb_queue_empty(&data->readq))
 216                 return POLLIN | POLLRDNORM;
 217
 218         return POLLOUT | POLLWRNORM;
 219 }
 220
 221 static int vhci_ioctl(struct inode *inode, struct file *file,
 222                                         unsigned int cmd, unsigned long arg)
 223 {
 224         return -EINVAL;
 225 }
 226
 227 static int vhci_open(struct inode *inode, struct file *file)
 228 {
 229         struct vhci_data *data;
 230         struct hci_dev *hdev;
 231
 232         data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 233         if (!data)
 234                 return -ENOMEM;
 235
 236         skb_queue_head_init(&data->readq);
 237         init_waitqueue_head(&data->read_wait);
 238
 239         hdev = hci_alloc_dev();
 240         if (!hdev) {
 241                 kfree(data);
 242                 return -ENOMEM;
 243         }
 244
 245         data->hdev = hdev;
 246
 247         hdev->type = HCI_VIRTUAL;
 248         hdev->driver_data = data;
 249
 250         hdev->open     = vhci_open_dev;
 251         hdev->close    = vhci_close_dev;
 252         hdev->flush    = vhci_flush;
 253         hdev->send     = vhci_send_frame;
 254         hdev->destruct = vhci_destruct;
 255
 256         hdev->owner = THIS_MODULE;
 257
 258         if (hci_register_dev(hdev) < 0) {
 259                 BT_ERR("Can't register HCI device");
 260                 kfree(data);
 261                 hci_free_dev(hdev);
 262                 return -EBUSY;
 263         }
 264
 265         file->private_data = data;
 266
 267         return nonseekable_open(inode, file);
 268 }
 269
 270 static int vhci_release(struct inode *inode, struct file *file)
 271 {
 272         struct vhci_data *data = file->private_data;
 273         struct hci_dev *hdev = data->hdev;
 274
 275         if (hci_unregister_dev(hdev) < 0) {
 276                 BT_ERR("Can't unregister HCI device %s", hdev->name);
 277         }
 278
 279         hci_free_dev(hdev);
 280
 281         file->private_data = NULL;
 282
 283         return 0;
 284 }
 285
 286 static const struct file_operations vhci_fops = {
 287         .read           = vhci_read,
 288         .write          = vhci_write,
 289         .poll           = vhci_poll,
 290         .ioctl          = vhci_ioctl,
 291         .open           = vhci_open,
 292         .release        = vhci_release,
 293 };
 294
 295 static struct miscdevice vhci_miscdev= {
 296         .name   = "vhci",
 297         .fops   = &vhci_fops,
 298         .minor  = MISC_DYNAMIC_MINOR,
 299 };
 300
 301 static int __init vhci_init(void)
 302 {
 303         BT_INFO("Virtual HCI driver ver %s", VERSION);
 304
 305         if (misc_register(&vhci_miscdev) < 0) {
 306                 BT_ERR("Can't register misc device with minor %d", minor);
 307                 return -EIO;
 308         }
 309
 310         return 0;
 311 }
 312
 313 static void __exit vhci_exit(void)
 314 {
 315         if (misc_deregister(&vhci_miscdev) < 0)
 316                 BT_ERR("Can't unregister misc device with minor %d", minor);
 317 }
 318
 319 module_init(vhci_init);
 320 module_exit(vhci_exit);
 321
 322 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 323 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 324 MODULE_VERSION(VERSION);
 325 MODULE_LICENSE("GPL");