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 = hci_get_drvdata(hdev);
  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 = hci_get_drvdata(hdev);
  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 = hci_get_drvdata(hdev);
  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 inline ssize_t vhci_get_user(struct vhci_data *data,
 107                                        const char __user *buf, size_t count)
 108{
 109        struct sk_buff *skb;
 110
 111        if (count > HCI_MAX_FRAME_SIZE)
 112                return -EINVAL;
 113
 114        skb = bt_skb_alloc(count, GFP_KERNEL);
 115        if (!skb)
 116                return -ENOMEM;
 117
 118        if (copy_from_user(skb_put(skb, count), buf, count)) {
 119                kfree_skb(skb);
 120                return -EFAULT;
 121        }
 122
 123        skb->dev = (void *) data->hdev;
 124        bt_cb(skb)->pkt_type = *((__u8 *) skb->data);
 125        skb_pull(skb, 1);
 126
 127        hci_recv_frame(skb);
 128
 129        return count;
 130}
 131
 132static inline ssize_t vhci_put_user(struct vhci_data *data,
 133                        struct sk_buff *skb, char __user *buf, int count)
 134{
 135        char __user *ptr = buf;
 136        int len, total = 0;
 137
 138        len = min_t(unsigned int, skb->len, count);
 139
 140        if (copy_to_user(ptr, skb->data, len))
 141                return -EFAULT;
 142
 143        total += len;
 144
 145        data->hdev->stat.byte_tx += len;
 146
 147        switch (bt_cb(skb)->pkt_type) {
 148        case HCI_COMMAND_PKT:
 149                data->hdev->stat.cmd_tx++;
 150                break;
 151
 152        case HCI_ACLDATA_PKT:
 153                data->hdev->stat.acl_tx++;
 154                break;
 155
 156        case HCI_SCODATA_PKT:
 157                data->hdev->stat.sco_tx++;
 158                break;
 159        }
 160
 161        return total;
 162}
 163
 164static ssize_t vhci_read(struct file *file,
 165                                char __user *buf, size_t count, loff_t *pos)
 166{
 167        struct vhci_data *data = file->private_data;
 168        struct sk_buff *skb;
 169        ssize_t ret = 0;
 170
 171        while (count) {
 172                skb = skb_dequeue(&data->readq);
 173                if (skb) {
 174                        ret = vhci_put_user(data, skb, buf, count);
 175                        if (ret < 0)
 176                                skb_queue_head(&data->readq, skb);
 177                        else
 178                                kfree_skb(skb);
 179                        break;
 180                }
 181
 182                if (file->f_flags & O_NONBLOCK) {
 183                        ret = -EAGAIN;
 184                        break;
 185                }
 186
 187                ret = wait_event_interruptible(data->read_wait,
 188                                        !skb_queue_empty(&data->readq));
 189                if (ret < 0)
 190                        break;
 191        }
 192
 193        return ret;
 194}
 195
 196static ssize_t vhci_write(struct file *file,
 197                        const char __user *buf, size_t count, loff_t *pos)
 198{
 199        struct vhci_data *data = file->private_data;
 200
 201        return vhci_get_user(data, buf, count);
 202}
 203
 204static unsigned int vhci_poll(struct file *file, poll_table *wait)
 205{
 206        struct vhci_data *data = file->private_data;
 207
 208        poll_wait(file, &data->read_wait, wait);
 209
 210        if (!skb_queue_empty(&data->readq))
 211                return POLLIN | POLLRDNORM;
 212
 213        return POLLOUT | POLLWRNORM;
 214}
 215
 216static int vhci_open(struct inode *inode, struct file *file)
 217{
 218        struct vhci_data *data;
 219        struct hci_dev *hdev;
 220
 221        data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
 222        if (!data)
 223                return -ENOMEM;
 224
 225        skb_queue_head_init(&data->readq);
 226        init_waitqueue_head(&data->read_wait);
 227
 228        hdev = hci_alloc_dev();
 229        if (!hdev) {
 230                kfree(data);
 231                return -ENOMEM;
 232        }
 233
 234        data->hdev = hdev;
 235
 236        hdev->bus = HCI_VIRTUAL;
 237        hci_set_drvdata(hdev, data);
 238
 239        if (amp)
 240                hdev->dev_type = HCI_AMP;
 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
 247        if (hci_register_dev(hdev) < 0) {
 248                BT_ERR("Can't register HCI device");
 249                kfree(data);
 250                hci_free_dev(hdev);
 251                return -EBUSY;
 252        }
 253
 254        file->private_data = data;
 255        nonseekable_open(inode, file);
 256
 257        return 0;
 258}
 259
 260static int vhci_release(struct inode *inode, struct file *file)
 261{
 262        struct vhci_data *data = file->private_data;
 263        struct hci_dev *hdev = data->hdev;
 264
 265        hci_unregister_dev(hdev);
 266        hci_free_dev(hdev);
 267
 268        file->private_data = NULL;
 269        kfree(data);
 270
 271        return 0;
 272}
 273
 274static const struct file_operations vhci_fops = {
 275        .owner          = THIS_MODULE,
 276        .read           = vhci_read,
 277        .write          = vhci_write,
 278        .poll           = vhci_poll,
 279        .open           = vhci_open,
 280        .release        = vhci_release,
 281        .llseek         = no_llseek,
 282};
 283
 284static struct miscdevice vhci_miscdev= {
 285        .name   = "vhci",
 286        .fops   = &vhci_fops,
 287        .minor  = MISC_DYNAMIC_MINOR,
 288};
 289
 290static int __init vhci_init(void)
 291{
 292        BT_INFO("Virtual HCI driver ver %s", VERSION);
 293
 294        return misc_register(&vhci_miscdev);
 295}
 296
 297static void __exit vhci_exit(void)
 298{
 299        misc_deregister(&vhci_miscdev);
 300}
 301
 302module_init(vhci_init);
 303module_exit(vhci_exit);
 304
 305module_param(amp, bool, 0644);
 306MODULE_PARM_DESC(amp, "Create AMP controller device");
 307
 308MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 309MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 310MODULE_VERSION(VERSION);
 311MODULE_LICENSE("GPL");
 312