1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Bluetooth virtual HCI driver
6 * Copyright (C) 2000-2001 Qualcomm Incorporated
7 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
8 * Copyright (C) 2004-2006 Marcel Holtmann <marcel@holtmann.org>
11 #include <linux/module.h>
12 #include <asm/unaligned.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/sched.h>
20 #include <linux/poll.h>
22 #include <linux/skbuff.h>
23 #include <linux/miscdevice.h>
25 #include <net/bluetooth/bluetooth.h>
26 #include <net/bluetooth/hci_core.h>
35 wait_queue_head_t read_wait;
36 struct sk_buff_head readq;
38 struct mutex open_mutex;
39 struct delayed_work open_timeout;
42 static int vhci_open_dev(struct hci_dev *hdev)
47 static int vhci_close_dev(struct hci_dev *hdev)
49 struct vhci_data *data = hci_get_drvdata(hdev);
51 skb_queue_purge(&data->readq);
56 static int vhci_flush(struct hci_dev *hdev)
58 struct vhci_data *data = hci_get_drvdata(hdev);
60 skb_queue_purge(&data->readq);
65 static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
67 struct vhci_data *data = hci_get_drvdata(hdev);
69 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
71 mutex_lock(&data->open_mutex);
72 skb_queue_tail(&data->readq, skb);
73 mutex_unlock(&data->open_mutex);
75 wake_up_interruptible(&data->read_wait);
79 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
88 /* bits 0-1 are dev_type (Primary or AMP) */
89 dev_type = opcode & 0x03;
91 if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
94 /* bits 2-5 are reserved (must be zero) */
98 skb = bt_skb_alloc(4, GFP_KERNEL);
102 hdev = hci_alloc_dev();
110 hdev->bus = HCI_VIRTUAL;
111 hdev->dev_type = dev_type;
112 hci_set_drvdata(hdev, data);
114 hdev->open = vhci_open_dev;
115 hdev->close = vhci_close_dev;
116 hdev->flush = vhci_flush;
117 hdev->send = vhci_send_frame;
119 /* bit 6 is for external configuration */
121 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
123 /* bit 7 is for raw device */
125 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
127 set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks);
129 if (hci_register_dev(hdev) < 0) {
130 BT_ERR("Can't register HCI device");
137 hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
139 skb_put_u8(skb, 0xff);
140 skb_put_u8(skb, opcode);
141 put_unaligned_le16(hdev->id, skb_put(skb, 2));
142 skb_queue_tail(&data->readq, skb);
144 wake_up_interruptible(&data->read_wait);
148 static int vhci_create_device(struct vhci_data *data, __u8 opcode)
152 mutex_lock(&data->open_mutex);
153 err = __vhci_create_device(data, opcode);
154 mutex_unlock(&data->open_mutex);
159 static inline ssize_t vhci_get_user(struct vhci_data *data,
160 struct iov_iter *from)
162 size_t len = iov_iter_count(from);
164 __u8 pkt_type, opcode;
167 if (len < 2 || len > HCI_MAX_FRAME_SIZE)
170 skb = bt_skb_alloc(len, GFP_KERNEL);
174 if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
179 pkt_type = *((__u8 *) skb->data);
184 case HCI_ACLDATA_PKT:
185 case HCI_SCODATA_PKT:
186 case HCI_ISODATA_PKT:
192 hci_skb_pkt_type(skb) = pkt_type;
194 ret = hci_recv_frame(data->hdev, skb);
198 cancel_delayed_work_sync(&data->open_timeout);
200 opcode = *((__u8 *) skb->data);
210 ret = vhci_create_device(data, opcode);
218 return (ret < 0) ? ret : len;
221 static inline ssize_t vhci_put_user(struct vhci_data *data,
223 char __user *buf, int count)
225 char __user *ptr = buf;
228 len = min_t(unsigned int, skb->len, count);
230 if (copy_to_user(ptr, skb->data, len))
236 data->hdev->stat.byte_tx += len;
238 switch (hci_skb_pkt_type(skb)) {
239 case HCI_COMMAND_PKT:
240 data->hdev->stat.cmd_tx++;
242 case HCI_ACLDATA_PKT:
243 data->hdev->stat.acl_tx++;
245 case HCI_SCODATA_PKT:
246 data->hdev->stat.sco_tx++;
253 static ssize_t vhci_read(struct file *file,
254 char __user *buf, size_t count, loff_t *pos)
256 struct vhci_data *data = file->private_data;
261 skb = skb_dequeue(&data->readq);
263 ret = vhci_put_user(data, skb, buf, count);
265 skb_queue_head(&data->readq, skb);
271 if (file->f_flags & O_NONBLOCK) {
276 ret = wait_event_interruptible(data->read_wait,
277 !skb_queue_empty(&data->readq));
285 static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
287 struct file *file = iocb->ki_filp;
288 struct vhci_data *data = file->private_data;
290 return vhci_get_user(data, from);
293 static __poll_t vhci_poll(struct file *file, poll_table *wait)
295 struct vhci_data *data = file->private_data;
297 poll_wait(file, &data->read_wait, wait);
299 if (!skb_queue_empty(&data->readq))
300 return EPOLLIN | EPOLLRDNORM;
302 return EPOLLOUT | EPOLLWRNORM;
305 static void vhci_open_timeout(struct work_struct *work)
307 struct vhci_data *data = container_of(work, struct vhci_data,
310 vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY);
313 static int vhci_open(struct inode *inode, struct file *file)
315 struct vhci_data *data;
317 data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
321 skb_queue_head_init(&data->readq);
322 init_waitqueue_head(&data->read_wait);
324 mutex_init(&data->open_mutex);
325 INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
327 file->private_data = data;
328 nonseekable_open(inode, file);
330 schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));
335 static int vhci_release(struct inode *inode, struct file *file)
337 struct vhci_data *data = file->private_data;
338 struct hci_dev *hdev;
340 cancel_delayed_work_sync(&data->open_timeout);
345 hci_unregister_dev(hdev);
349 skb_queue_purge(&data->readq);
350 file->private_data = NULL;
356 static const struct file_operations vhci_fops = {
357 .owner = THIS_MODULE,
359 .write_iter = vhci_write,
362 .release = vhci_release,
366 static struct miscdevice vhci_miscdev = {
371 module_misc_device(vhci_miscdev);
373 module_param(amp, bool, 0644);
374 MODULE_PARM_DESC(amp, "Create AMP controller device");
376 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
377 MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
378 MODULE_VERSION(VERSION);
379 MODULE_LICENSE("GPL");
380 MODULE_ALIAS("devname:vhci");
381 MODULE_ALIAS_MISCDEV(VHCI_MINOR);