Root/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
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

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