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