| 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 | |
| 45 | static bool amp; |
| 46 | |
| 47 | struct 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 | |
| 57 | static int vhci_open_dev(struct hci_dev *hdev) |
| 58 | { |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static 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 | |
| 71 | static 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 | |
| 80 | static 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 | |
| 91 | static 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(skb, 1) = 0xff; |
| 150 | *skb_put(skb, 1) = 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 | |
| 158 | static 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 | |
| 169 | static 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(skb_put(skb, len), len, from) != len) { |
| 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 | |
| 230 | static 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 | |
| 262 | static 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 | |
| 294 | static 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 | |
| 302 | static 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 | |
| 314 | static 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 | |
| 322 | static 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 | |
| 344 | static 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 | |
| 365 | static 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 | |
| 375 | static struct miscdevice vhci_miscdev = { |
| 376 | .name = "vhci", |
| 377 | .fops = &vhci_fops, |
| 378 | .minor = VHCI_MINOR, |
| 379 | }; |
| 380 | |
| 381 | static int __init vhci_init(void) |
| 382 | { |
| 383 | BT_INFO("Virtual HCI driver ver %s", VERSION); |
| 384 | |
| 385 | return misc_register(&vhci_miscdev); |
| 386 | } |
| 387 | |
| 388 | static void __exit vhci_exit(void) |
| 389 | { |
| 390 | misc_deregister(&vhci_miscdev); |
| 391 | } |
| 392 | |
| 393 | module_init(vhci_init); |
| 394 | module_exit(vhci_exit); |
| 395 | |
| 396 | module_param(amp, bool, 0644); |
| 397 | MODULE_PARM_DESC(amp, "Create AMP controller device"); |
| 398 | |
| 399 | MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); |
| 400 | MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION); |
| 401 | MODULE_VERSION(VERSION); |
| 402 | MODULE_LICENSE("GPL"); |
| 403 | MODULE_ALIAS("devname:vhci"); |
| 404 | MODULE_ALIAS_MISCDEV(VHCI_MINOR); |