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#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
  45static bool amp;
  46
  47struct 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
  57static int vhci_open_dev(struct hci_dev *hdev)
  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        skb_queue_purge(&data->readq);
  67
  68        return 0;
  69}
  70
  71static 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
  80static 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
  91static 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 (Primary or AMP) */
 101        dev_type = opcode & 0x03;
 102
 103        if (dev_type != HCI_PRIMARY && 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_u8(skb, 0xff);
 150        skb_put_u8(skb, 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
 158static 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
 169static 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_full(skb_put(skb, len), len, from)) {
 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
 230static 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
 262static 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
 294static 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
 302static 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
 314static 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_PRIMARY);
 320}
 321
 322static 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
 344static 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
 365static 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
 375static struct miscdevice vhci_miscdev = {
 376        .name   = "vhci",
 377        .fops   = &vhci_fops,
 378        .minor  = VHCI_MINOR,
 379};
 380module_misc_device(vhci_miscdev);
 381
 382module_param(amp, bool, 0644);
 383MODULE_PARM_DESC(amp, "Create AMP controller device");
 384
 385MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 386MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
 387MODULE_VERSION(VERSION);
 388MODULE_LICENSE("GPL");
 389MODULE_ALIAS("devname:vhci");
 390MODULE_ALIAS_MISCDEV(VHCI_MINOR);
 391