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 __poll_t 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 EPOLLIN | EPOLLRDNORM;
310
311 return EPOLLOUT | EPOLLWRNORM;
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