linux/drivers/bluetooth/hci_vhci.c
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   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
  44static bool amp;
  45
  46struct 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
  55static int vhci_open_dev(struct hci_dev *hdev)
  56{
  57        set_bit(HCI_RUNNING, &hdev->flags);
  58
  59        return 0;
  60}
  61
  62static 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
  74static 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
  83static 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
 106static void vhci_destruct(struct hci_dev *hdev)
 107{
 108        kfree(hdev->driver_data);
 109}
 110
 111static 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
 137static 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.sco_tx++;
 163                break;
 164        };
 165
 166        return total;
 167}
 168
 169static 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
 201static 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
 209static 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
 221static int vhci_open(struct inode *inode, struct file *file)
 222{
 223        struct vhci_data *data;
 224        struct hci_dev *hdev;
 225
 226        data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 227        if (!data)
 228                return -ENOMEM;
 229
 230        skb_queue_head_init(&data->readq);
 231        init_waitqueue_head(&data->read_wait);
 232
 233        hdev = hci_alloc_dev();
 234        if (!hdev) {
 235                kfree(data);
 236                return -ENOMEM;
 237        }
 238
 239        data->hdev = hdev;
 240
 241        hdev->bus = HCI_VIRTUAL;
 242        hdev->driver_data = data;
 243
 244        if (amp)
 245                hdev->dev_type = HCI_AMP;
 246
 247        hdev->open     = vhci_open_dev;
 248        hdev->close    = vhci_close_dev;
 249        hdev->flush    = vhci_flush;
 250        hdev->send     = vhci_send_frame;
 251        hdev->destruct = vhci_destruct;
 252
 253        hdev->owner = THIS_MODULE;
 254
 255        if (hci_register_dev(hdev) < 0) {
 256                BT_ERR("Can't register HCI device");
 257                kfree(data);
 258                hci_free_dev(hdev);
 259                return -EBUSY;
 260        }
 261
 262        file->private_data = data;
 263
 264        return nonseekable_open(inode, file);
 265}
 266
 267static int vhci_release(struct inode *inode, struct file *file)
 268{
 269        struct vhci_data *data = file->private_data;
 270        struct hci_dev *hdev = data->hdev;
 271
 272        hci_unregister_dev(hdev);
 273        hci_free_dev(hdev);
 274
 275        file->private_data = NULL;
 276
 277        return 0;
 278}
 279
 280static const struct file_operations vhci_fops = {
 281        .owner          = THIS_MODULE,
 282        .read           = vhci_read,
 283        .write          = vhci_write,
 284        .poll           = vhci_poll,
 285        .open           = vhci_open,
 286        .release        = vhci_release,
 287        .llseek         = no_llseek,
 288};
 289
 290static struct miscdevice vhci_miscdev= {
 291        .name   = "vhci",
 292        .fops   = &vhci_fops,
 293        .minor  = MISC_DYNAMIC_MINOR,
 294};
 295
 296static int __init vhci_init(void)
 297{
 298        BT_INFO("Virtual HCI driver ver %s", VERSION);
 299
 300        return misc_register(&vhci_miscdev);
 301}
 302
 303static void __exit vhci_exit(void)
 304{
 305        misc_deregister(&vhci_miscdev);
 306}
 307
 308module_init(vhci_init);
 309module_exit(vhci_exit);
 310
 311module_param(amp, bool, 0644);
 312MODULE_PARM_DESC(amp, "Create AMP controller device");
 313
 314MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 315MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 316MODULE_VERSION(VERSION);
 317MODULE_LICENSE("GPL");
 318