net/bluetooth/rfcomm/tty.c

   1 /*
   2    RFCOMM implementation for Linux Bluetooth stack (BlueZ).
   3    Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4    Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License version 2 as
   8    published by the Free Software Foundation;
   9
  10    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  11    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  12    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
  13    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
  14    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
  15    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18
  19    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
  20    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  21    SOFTWARE IS DISCLAIMED.
  22 */
  23
  24 /*
  25  * RFCOMM TTY.
  26  *
  27  * $Id: tty.c,v 1.24 2002/10/03 01:54:38 holtmann Exp $
  28  */
  29
  30 #include <linux/module.h>
  31
  32 #include <linux/tty.h>
  33 #include <linux/tty_driver.h>
  34 #include <linux/tty_flip.h>
  35
  36 #include <linux/capability.h>
  37 #include <linux/slab.h>
  38 #include <linux/skbuff.h>
  39
  40 #include <net/bluetooth/bluetooth.h>
  41 #include <net/bluetooth/hci_core.h>
  42 #include <net/bluetooth/rfcomm.h>
  43
  44 #ifndef CONFIG_BT_RFCOMM_DEBUG
  45 #undef  BT_DBG
  46 #define BT_DBG(D...)
  47 #endif
  48
  49 #define RFCOMM_TTY_MAGIC 0x6d02         /* magic number for rfcomm struct */
  50 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV /* whole lotta rfcomm devices */
  51 #define RFCOMM_TTY_MAJOR 216            /* device node major id of the usb/bluetooth.c driver */
  52 #define RFCOMM_TTY_MINOR 0
  53
  54 static struct tty_driver *rfcomm_tty_driver;
  55
  56 struct rfcomm_dev {
  57         struct list_head        list;
  58         atomic_t                refcnt;
  59
  60         char                    name[12];
  61         int                     id;
  62         unsigned long           flags;
  63         int                     opened;
  64         int                     err;
  65
  66         bdaddr_t                src;
  67         bdaddr_t                dst;
  68         u8                      channel;
  69
  70         uint                    modem_status;
  71
  72         struct rfcomm_dlc       *dlc;
  73         struct tty_struct       *tty;
  74         wait_queue_head_t       wait;
  75         struct tasklet_struct   wakeup_task;
  76
  77         struct device           *tty_dev;
  78
  79         atomic_t                wmem_alloc;
  80 };
  81
  82 static LIST_HEAD(rfcomm_dev_list);
  83 static DEFINE_RWLOCK(rfcomm_dev_lock);
  84
  85 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
  86 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
  87 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
  88
  89 static void rfcomm_tty_wakeup(unsigned long arg);
  90
  91 /* ---- Device functions ---- */
  92 static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
  93 {
  94         struct rfcomm_dlc *dlc = dev->dlc;
  95
  96         BT_DBG("dev %p dlc %p", dev, dlc);
  97
  98         /* Refcount should only hit zero when called from rfcomm_dev_del()
  99            which will have taken us off the list. Everything else are
 100            refcounting bugs. */
 101         BUG_ON(!list_empty(&dev->list));
 102
 103         rfcomm_dlc_lock(dlc);
 104         /* Detach DLC if it's owned by this dev */
 105         if (dlc->owner == dev)
 106                 dlc->owner = NULL;
 107         rfcomm_dlc_unlock(dlc);
 108
 109         rfcomm_dlc_put(dlc);
 110
 111         tty_unregister_device(rfcomm_tty_driver, dev->id);
 112
 113         kfree(dev);
 114
 115         /* It's safe to call module_put() here because socket still
 116            holds reference to this module. */
 117         module_put(THIS_MODULE);
 118 }
 119
 120 static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
 121 {
 122         atomic_inc(&dev->refcnt);
 123 }
 124
 125 static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
 126 {
 127         /* The reason this isn't actually a race, as you no
 128            doubt have a little voice screaming at you in your
 129            head, is that the refcount should never actually
 130            reach zero unless the device has already been taken
 131            off the list, in rfcomm_dev_del(). And if that's not
 132            true, we'll hit the BUG() in rfcomm_dev_destruct()
 133            anyway. */
 134         if (atomic_dec_and_test(&dev->refcnt))
 135                 rfcomm_dev_destruct(dev);
 136 }
 137
 138 static struct rfcomm_dev *__rfcomm_dev_get(int id)
 139 {
 140         struct rfcomm_dev *dev;
 141         struct list_head  *p;
 142
 143         list_for_each(p, &rfcomm_dev_list) {
 144                 dev = list_entry(p, struct rfcomm_dev, list);
 145                 if (dev->id == id)
 146                         return dev;
 147         }
 148
 149         return NULL;
 150 }
 151
 152 static inline struct rfcomm_dev *rfcomm_dev_get(int id)
 153 {
 154         struct rfcomm_dev *dev;
 155
 156         read_lock(&rfcomm_dev_lock);
 157
 158         dev = __rfcomm_dev_get(id);
 159
 160         if (dev) {
 161                 if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
 162                         dev = NULL;
 163                 else
 164                         rfcomm_dev_hold(dev);
 165         }
 166
 167         read_unlock(&rfcomm_dev_lock);
 168
 169         return dev;
 170 }
 171
 172 static struct device *rfcomm_get_device(struct rfcomm_dev *dev)
 173 {
 174         struct hci_dev *hdev;
 175         struct hci_conn *conn;
 176
 177         hdev = hci_get_route(&dev->dst, &dev->src);
 178         if (!hdev)
 179                 return NULL;
 180
 181         conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &dev->dst);
 182
 183         hci_dev_put(hdev);
 184
 185         return conn ? &conn->dev : NULL;
 186 }
 187
 188 static ssize_t show_address(struct device *tty_dev, struct device_attribute *attr, char *buf)
 189 {
 190         struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
 191         bdaddr_t bdaddr;
 192         baswap(&bdaddr, &dev->dst);
 193         return sprintf(buf, "%s\n", batostr(&bdaddr));
 194 }
 195
 196 static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
 197 {
 198         struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
 199         return sprintf(buf, "%d\n", dev->channel);
 200 }
 201
 202 static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
 203 static DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
 204
 205 static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 206 {
 207         struct rfcomm_dev *dev;
 208         struct list_head *head = &rfcomm_dev_list, *p;
 209         int err = 0;
 210
 211         BT_DBG("id %d channel %d", req->dev_id, req->channel);
 212
 213         dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
 214         if (!dev)
 215                 return -ENOMEM;
 216
 217         write_lock_bh(&rfcomm_dev_lock);
 218
 219         if (req->dev_id < 0) {
 220                 dev->id = 0;
 221
 222                 list_for_each(p, &rfcomm_dev_list) {
 223                         if (list_entry(p, struct rfcomm_dev, list)->id != dev->id)
 224                                 break;
 225
 226                         dev->id++;
 227                         head = p;
 228                 }
 229         } else {
 230                 dev->id = req->dev_id;
 231
 232                 list_for_each(p, &rfcomm_dev_list) {
 233                         struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list);
 234
 235                         if (entry->id == dev->id) {
 236                                 err = -EADDRINUSE;
 237                                 goto out;
 238                         }
 239
 240                         if (entry->id > dev->id - 1)
 241                                 break;
 242
 243                         head = p;
 244                 }
 245         }
 246
 247         if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
 248                 err = -ENFILE;
 249                 goto out;
 250         }
 251
 252         sprintf(dev->name, "rfcomm%d", dev->id);
 253
 254         list_add(&dev->list, head);
 255         atomic_set(&dev->refcnt, 1);
 256
 257         bacpy(&dev->src, &req->src);
 258         bacpy(&dev->dst, &req->dst);
 259         dev->channel = req->channel;
 260
 261         dev->flags = req->flags &
 262                 ((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
 263
 264         init_waitqueue_head(&dev->wait);
 265         tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev);
 266
 267         rfcomm_dlc_lock(dlc);
 268         dlc->data_ready   = rfcomm_dev_data_ready;
 269         dlc->state_change = rfcomm_dev_state_change;
 270         dlc->modem_status = rfcomm_dev_modem_status;
 271
 272         dlc->owner = dev;
 273         dev->dlc   = dlc;
 274         rfcomm_dlc_unlock(dlc);
 275
 276         /* It's safe to call __module_get() here because socket already
 277            holds reference to this module. */
 278         __module_get(THIS_MODULE);
 279
 280 out:
 281         write_unlock_bh(&rfcomm_dev_lock);
 282
 283         if (err < 0) {
 284                 kfree(dev);
 285                 return err;
 286         }
 287
 288         dev->tty_dev = tty_register_device(rfcomm_tty_driver, dev->id, NULL);
 289
 290         if (IS_ERR(dev->tty_dev)) {
 291                 err = PTR_ERR(dev->tty_dev);
 292                 list_del(&dev->list);
 293                 kfree(dev);
 294                 return err;
 295         }
 296
 297         dev_set_drvdata(dev->tty_dev, dev);
 298
 299         if (device_create_file(dev->tty_dev, &dev_attr_address) < 0)
 300                 BT_ERR("Failed to create address attribute");
 301
 302         if (device_create_file(dev->tty_dev, &dev_attr_channel) < 0)
 303                 BT_ERR("Failed to create channel attribute");
 304
 305         return dev->id;
 306 }
 307
 308 static void rfcomm_dev_del(struct rfcomm_dev *dev)
 309 {
 310         BT_DBG("dev %p", dev);
 311
 312         if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
 313                 BUG_ON(1);
 314         else
 315                 set_bit(RFCOMM_TTY_RELEASED, &dev->flags);
 316
 317         write_lock_bh(&rfcomm_dev_lock);
 318         list_del_init(&dev->list);
 319         write_unlock_bh(&rfcomm_dev_lock);
 320
 321         rfcomm_dev_put(dev);
 322 }
 323
 324 /* ---- Send buffer ---- */
 325 static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
 326 {
 327         /* We can't let it be zero, because we don't get a callback
 328            when tx_credits becomes nonzero, hence we'd never wake up */
 329         return dlc->mtu * (dlc->tx_credits?:1);
 330 }
 331
 332 static void rfcomm_wfree(struct sk_buff *skb)
 333 {
 334         struct rfcomm_dev *dev = (void *) skb->sk;
 335         atomic_sub(skb->truesize, &dev->wmem_alloc);
 336         if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
 337                 tasklet_schedule(&dev->wakeup_task);
 338         rfcomm_dev_put(dev);
 339 }
 340
 341 static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
 342 {
 343         rfcomm_dev_hold(dev);
 344         atomic_add(skb->truesize, &dev->wmem_alloc);
 345         skb->sk = (void *) dev;
 346         skb->destructor = rfcomm_wfree;
 347 }
 348
 349 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
 350 {
 351         if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
 352                 struct sk_buff *skb = alloc_skb(size, priority);
 353                 if (skb) {
 354                         rfcomm_set_owner_w(skb, dev);
 355                         return skb;
 356                 }
 357         }
 358         return NULL;
 359 }
 360
 361 /* ---- Device IOCTLs ---- */
 362
 363 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
 364
 365 static int rfcomm_create_dev(struct sock *sk, void __user *arg)
 366 {
 367         struct rfcomm_dev_req req;
 368         struct rfcomm_dlc *dlc;
 369         int id;
 370
 371         if (copy_from_user(&req, arg, sizeof(req)))
 372                 return -EFAULT;
 373
 374         BT_DBG("sk %p dev_id %d flags 0x%x", sk, req.dev_id, req.flags);
 375
 376         if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
 377                 return -EPERM;
 378
 379         if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
 380                 /* Socket must be connected */
 381                 if (sk->sk_state != BT_CONNECTED)
 382                         return -EBADFD;
 383
 384                 dlc = rfcomm_pi(sk)->dlc;
 385                 rfcomm_dlc_hold(dlc);
 386         } else {
 387                 dlc = rfcomm_dlc_alloc(GFP_KERNEL);
 388                 if (!dlc)
 389                         return -ENOMEM;
 390         }
 391
 392         id = rfcomm_dev_add(&req, dlc);
 393         if (id < 0) {
 394                 rfcomm_dlc_put(dlc);
 395                 return id;
 396         }
 397
 398         if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
 399                 /* DLC is now used by device.
 400                  * Socket must be disconnected */
 401                 sk->sk_state = BT_CLOSED;
 402         }
 403
 404         return id;
 405 }
 406
 407 static int rfcomm_release_dev(void __user *arg)
 408 {
 409         struct rfcomm_dev_req req;
 410         struct rfcomm_dev *dev;
 411
 412         if (copy_from_user(&req, arg, sizeof(req)))
 413                 return -EFAULT;
 414
 415         BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
 416
 417         if (!(dev = rfcomm_dev_get(req.dev_id)))
 418                 return -ENODEV;
 419
 420         if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
 421                 rfcomm_dev_put(dev);
 422                 return -EPERM;
 423         }
 424
 425         if (req.flags & (1 << RFCOMM_HANGUP_NOW))
 426                 rfcomm_dlc_close(dev->dlc, 0);
 427
 428         /* Shut down TTY synchronously before freeing rfcomm_dev */
 429         if (dev->tty)
 430                 tty_vhangup(dev->tty);
 431
 432         if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
 433                 rfcomm_dev_del(dev);
 434         rfcomm_dev_put(dev);
 435         return 0;
 436 }
 437
 438 static int rfcomm_get_dev_list(void __user *arg)
 439 {
 440         struct rfcomm_dev_list_req *dl;
 441         struct rfcomm_dev_info *di;
 442         struct list_head *p;
 443         int n = 0, size, err;
 444         u16 dev_num;
 445
 446         BT_DBG("");
 447
 448         if (get_user(dev_num, (u16 __user *) arg))
 449                 return -EFAULT;
 450
 451         if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
 452                 return -EINVAL;
 453
 454         size = sizeof(*dl) + dev_num * sizeof(*di);
 455
 456         if (!(dl = kmalloc(size, GFP_KERNEL)))
 457                 return -ENOMEM;
 458
 459         di = dl->dev_info;
 460
 461         read_lock_bh(&rfcomm_dev_lock);
 462
 463         list_for_each(p, &rfcomm_dev_list) {
 464                 struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list);
 465                 if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
 466                         continue;
 467                 (di + n)->id      = dev->id;
 468                 (di + n)->flags   = dev->flags;
 469                 (di + n)->state   = dev->dlc->state;
 470                 (di + n)->channel = dev->channel;
 471                 bacpy(&(di + n)->src, &dev->src);
 472                 bacpy(&(di + n)->dst, &dev->dst);
 473                 if (++n >= dev_num)
 474                         break;
 475         }
 476
 477         read_unlock_bh(&rfcomm_dev_lock);
 478
 479         dl->dev_num = n;
 480         size = sizeof(*dl) + n * sizeof(*di);
 481
 482         err = copy_to_user(arg, dl, size);
 483         kfree(dl);
 484
 485         return err ? -EFAULT : 0;
 486 }
 487
 488 static int rfcomm_get_dev_info(void __user *arg)
 489 {
 490         struct rfcomm_dev *dev;
 491         struct rfcomm_dev_info di;
 492         int err = 0;
 493
 494         BT_DBG("");
 495
 496         if (copy_from_user(&di, arg, sizeof(di)))
 497                 return -EFAULT;
 498
 499         if (!(dev = rfcomm_dev_get(di.id)))
 500                 return -ENODEV;
 501
 502         di.flags   = dev->flags;
 503         di.channel = dev->channel;
 504         di.state   = dev->dlc->state;
 505         bacpy(&di.src, &dev->src);
 506         bacpy(&di.dst, &dev->dst);
 507
 508         if (copy_to_user(arg, &di, sizeof(di)))
 509                 err = -EFAULT;
 510
 511         rfcomm_dev_put(dev);
 512         return err;
 513 }
 514
 515 int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
 516 {
 517         BT_DBG("cmd %d arg %p", cmd, arg);
 518
 519         switch (cmd) {
 520         case RFCOMMCREATEDEV:
 521                 return rfcomm_create_dev(sk, arg);
 522
 523         case RFCOMMRELEASEDEV:
 524                 return rfcomm_release_dev(arg);
 525
 526         case RFCOMMGETDEVLIST:
 527                 return rfcomm_get_dev_list(arg);
 528
 529         case RFCOMMGETDEVINFO:
 530                 return rfcomm_get_dev_info(arg);
 531         }
 532
 533         return -EINVAL;
 534 }
 535
 536 /* ---- DLC callbacks ---- */
 537 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
 538 {
 539         struct rfcomm_dev *dev = dlc->owner;
 540         struct tty_struct *tty;
 541
 542         if (!dev || !(tty = dev->tty)) {
 543                 kfree_skb(skb);
 544                 return;
 545         }
 546
 547         BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
 548
 549         tty_insert_flip_string(tty, skb->data, skb->len);
 550         tty_flip_buffer_push(tty);
 551
 552         kfree_skb(skb);
 553 }
 554
 555 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
 556 {
 557         struct rfcomm_dev *dev = dlc->owner;
 558         if (!dev)
 559                 return;
 560
 561         BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
 562
 563         dev->err = err;
 564         wake_up_interruptible(&dev->wait);
 565
 566         if (dlc->state == BT_CLOSED) {
 567                 if (!dev->tty) {
 568                         if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
 569                                 /* Drop DLC lock here to avoid deadlock
 570                                  * 1. rfcomm_dev_get will take rfcomm_dev_lock
 571                                  *    but in rfcomm_dev_add there's lock order:
 572                                  *    rfcomm_dev_lock -> dlc lock
 573                                  * 2. rfcomm_dev_put will deadlock if it's
 574                                  *    the last reference
 575                                  */
 576                                 rfcomm_dlc_unlock(dlc);
 577                                 if (rfcomm_dev_get(dev->id) == NULL) {
 578                                         rfcomm_dlc_lock(dlc);
 579                                         return;
 580                                 }
 581
 582                                 rfcomm_dev_del(dev);
 583                                 rfcomm_dev_put(dev);
 584                                 rfcomm_dlc_lock(dlc);
 585                         }
 586                 } else
 587                         tty_hangup(dev->tty);
 588         }
 589 }
 590
 591 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
 592 {
 593         struct rfcomm_dev *dev = dlc->owner;
 594         if (!dev)
 595                 return;
 596
 597         BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
 598
 599         if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV)) {
 600                 if (dev->tty && !C_CLOCAL(dev->tty))
 601                         tty_hangup(dev->tty);
 602         }
 603
 604         dev->modem_status =
 605                 ((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
 606                 ((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
 607                 ((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
 608                 ((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
 609 }
 610
 611 /* ---- TTY functions ---- */
 612 static void rfcomm_tty_wakeup(unsigned long arg)
 613 {
 614         struct rfcomm_dev *dev = (void *) arg;
 615         struct tty_struct *tty = dev->tty;
 616         if (!tty)
 617                 return;
 618
 619         BT_DBG("dev %p tty %p", dev, tty);
 620         tty_wakeup(tty);
 621 }
 622
 623 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
 624 {
 625         DECLARE_WAITQUEUE(wait, current);
 626         struct rfcomm_dev *dev;
 627         struct rfcomm_dlc *dlc;
 628         int err, id;
 629
 630         id = tty->index;
 631
 632         BT_DBG("tty %p id %d", tty, id);
 633
 634         /* We don't leak this refcount. For reasons which are not entirely
 635            clear, the TTY layer will call our ->close() method even if the
 636            open fails. We decrease the refcount there, and decreasing it
 637            here too would cause breakage. */
 638         dev = rfcomm_dev_get(id);
 639         if (!dev)
 640                 return -ENODEV;
 641
 642         BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst), dev->channel, dev->opened);
 643
 644         if (dev->opened++ != 0)
 645                 return 0;
 646
 647         dlc = dev->dlc;
 648
 649         /* Attach TTY and open DLC */
 650
 651         rfcomm_dlc_lock(dlc);
 652         tty->driver_data = dev;
 653         dev->tty = tty;
 654         rfcomm_dlc_unlock(dlc);
 655         set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 656
 657         err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
 658         if (err < 0)
 659                 return err;
 660
 661         /* Wait for DLC to connect */
 662         add_wait_queue(&dev->wait, &wait);
 663         while (1) {
 664                 set_current_state(TASK_INTERRUPTIBLE);
 665
 666                 if (dlc->state == BT_CLOSED) {
 667                         err = -dev->err;
 668                         break;
 669                 }
 670
 671                 if (dlc->state == BT_CONNECTED)
 672                         break;
 673
 674                 if (signal_pending(current)) {
 675                         err = -EINTR;
 676                         break;
 677                 }
 678
 679                 schedule();
 680         }
 681         set_current_state(TASK_RUNNING);
 682         remove_wait_queue(&dev->wait, &wait);
 683
 684         if (err == 0)
 685                 device_move(dev->tty_dev, rfcomm_get_device(dev));
 686
 687         return err;
 688 }
 689
 690 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 691 {
 692         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 693         if (!dev)
 694                 return;
 695
 696         BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc, dev->opened);
 697
 698         if (--dev->opened == 0) {
 699                 if (dev->tty_dev->parent)
 700                         device_move(dev->tty_dev, NULL);
 701
 702                 /* Close DLC and dettach TTY */
 703                 rfcomm_dlc_close(dev->dlc, 0);
 704
 705                 clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 706                 tasklet_kill(&dev->wakeup_task);
 707
 708                 rfcomm_dlc_lock(dev->dlc);
 709                 tty->driver_data = NULL;
 710                 dev->tty = NULL;
 711                 rfcomm_dlc_unlock(dev->dlc);
 712         }
 713
 714         rfcomm_dev_put(dev);
 715 }
 716
 717 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 718 {
 719         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 720         struct rfcomm_dlc *dlc = dev->dlc;
 721         struct sk_buff *skb;
 722         int err = 0, sent = 0, size;
 723
 724         BT_DBG("tty %p count %d", tty, count);
 725
 726         while (count) {
 727                 size = min_t(uint, count, dlc->mtu);
 728
 729                 skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
 730
 731                 if (!skb)
 732                         break;
 733
 734                 skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
 735
 736                 memcpy(skb_put(skb, size), buf + sent, size);
 737
 738                 if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
 739                         kfree_skb(skb);
 740                         break;
 741                 }
 742
 743                 sent  += size;
 744                 count -= size;
 745         }
 746
 747         return sent ? sent : err;
 748 }
 749
 750 static int rfcomm_tty_write_room(struct tty_struct *tty)
 751 {
 752         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 753         int room;
 754
 755         BT_DBG("tty %p", tty);
 756
 757         if (!dev || !dev->dlc)
 758                 return 0;
 759
 760         room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
 761         if (room < 0)
 762                 room = 0;
 763
 764         return room;
 765 }
 766
 767 static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
 768 {
 769         BT_DBG("tty %p cmd 0x%02x", tty, cmd);
 770
 771         switch (cmd) {
 772         case TCGETS:
 773                 BT_DBG("TCGETS is not supported");
 774                 return -ENOIOCTLCMD;
 775
 776         case TCSETS:
 777                 BT_DBG("TCSETS is not supported");
 778                 return -ENOIOCTLCMD;
 779
 780         case TIOCMIWAIT:
 781                 BT_DBG("TIOCMIWAIT");
 782                 break;
 783
 784         case TIOCGICOUNT:
 785                 BT_DBG("TIOCGICOUNT");
 786                 break;
 787
 788         case TIOCGSERIAL:
 789                 BT_ERR("TIOCGSERIAL is not supported");
 790                 return -ENOIOCTLCMD;
 791
 792         case TIOCSSERIAL:
 793                 BT_ERR("TIOCSSERIAL is not supported");
 794                 return -ENOIOCTLCMD;
 795
 796         case TIOCSERGSTRUCT:
 797                 BT_ERR("TIOCSERGSTRUCT is not supported");
 798                 return -ENOIOCTLCMD;
 799
 800         case TIOCSERGETLSR:
 801                 BT_ERR("TIOCSERGETLSR is not supported");
 802                 return -ENOIOCTLCMD;
 803
 804         case TIOCSERCONFIG:
 805                 BT_ERR("TIOCSERCONFIG is not supported");
 806                 return -ENOIOCTLCMD;
 807
 808         default:
 809                 return -ENOIOCTLCMD;    /* ioctls which we must ignore */
 810
 811         }
 812
 813         return -ENOIOCTLCMD;
 814 }
 815
 816 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 817 {
 818         struct ktermios *new = tty->termios;
 819         int old_baud_rate = tty_termios_baud_rate(old);
 820         int new_baud_rate = tty_termios_baud_rate(new);
 821
 822         u8 baud, data_bits, stop_bits, parity, x_on, x_off;
 823         u16 changes = 0;
 824
 825         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 826
 827         BT_DBG("tty %p termios %p", tty, old);
 828
 829         if (!dev || !dev->dlc || !dev->dlc->session)
 830                 return;
 831
 832         /* Handle turning off CRTSCTS */
 833         if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
 834                 BT_DBG("Turning off CRTSCTS unsupported");
 835
 836         /* Parity on/off and when on, odd/even */
 837         if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
 838                         ((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
 839                 changes |= RFCOMM_RPN_PM_PARITY;
 840                 BT_DBG("Parity change detected.");
 841         }
 842
 843         /* Mark and space parity are not supported! */
 844         if (new->c_cflag & PARENB) {
 845                 if (new->c_cflag & PARODD) {
 846                         BT_DBG("Parity is ODD");
 847                         parity = RFCOMM_RPN_PARITY_ODD;
 848                 } else {
 849                         BT_DBG("Parity is EVEN");
 850                         parity = RFCOMM_RPN_PARITY_EVEN;
 851                 }
 852         } else {
 853                 BT_DBG("Parity is OFF");
 854                 parity = RFCOMM_RPN_PARITY_NONE;
 855         }
 856
 857         /* Setting the x_on / x_off characters */
 858         if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
 859                 BT_DBG("XOFF custom");
 860                 x_on = new->c_cc[VSTOP];
 861                 changes |= RFCOMM_RPN_PM_XON;
 862         } else {
 863                 BT_DBG("XOFF default");
 864                 x_on = RFCOMM_RPN_XON_CHAR;
 865         }
 866
 867         if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
 868                 BT_DBG("XON custom");
 869                 x_off = new->c_cc[VSTART];
 870                 changes |= RFCOMM_RPN_PM_XOFF;
 871         } else {
 872                 BT_DBG("XON default");
 873                 x_off = RFCOMM_RPN_XOFF_CHAR;
 874         }
 875
 876         /* Handle setting of stop bits */
 877         if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
 878                 changes |= RFCOMM_RPN_PM_STOP;
 879
 880         /* POSIX does not support 1.5 stop bits and RFCOMM does not
 881          * support 2 stop bits. So a request for 2 stop bits gets
 882          * translated to 1.5 stop bits */
 883         if (new->c_cflag & CSTOPB) {
 884                 stop_bits = RFCOMM_RPN_STOP_15;
 885         } else {
 886                 stop_bits = RFCOMM_RPN_STOP_1;
 887         }
 888
 889         /* Handle number of data bits [5-8] */
 890         if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
 891                 changes |= RFCOMM_RPN_PM_DATA;
 892
 893         switch (new->c_cflag & CSIZE) {
 894         case CS5:
 895                 data_bits = RFCOMM_RPN_DATA_5;
 896                 break;
 897         case CS6:
 898                 data_bits = RFCOMM_RPN_DATA_6;
 899                 break;
 900         case CS7:
 901                 data_bits = RFCOMM_RPN_DATA_7;
 902                 break;
 903         case CS8:
 904                 data_bits = RFCOMM_RPN_DATA_8;
 905                 break;
 906         default:
 907                 data_bits = RFCOMM_RPN_DATA_8;
 908                 break;
 909         }
 910
 911         /* Handle baudrate settings */
 912         if (old_baud_rate != new_baud_rate)
 913                 changes |= RFCOMM_RPN_PM_BITRATE;
 914
 915         switch (new_baud_rate) {
 916         case 2400:
 917                 baud = RFCOMM_RPN_BR_2400;
 918                 break;
 919         case 4800:
 920                 baud = RFCOMM_RPN_BR_4800;
 921                 break;
 922         case 7200:
 923                 baud = RFCOMM_RPN_BR_7200;
 924                 break;
 925         case 9600:
 926                 baud = RFCOMM_RPN_BR_9600;
 927                 break;
 928         case 19200:
 929                 baud = RFCOMM_RPN_BR_19200;
 930                 break;
 931         case 38400:
 932                 baud = RFCOMM_RPN_BR_38400;
 933                 break;
 934         case 57600:
 935                 baud = RFCOMM_RPN_BR_57600;
 936                 break;
 937         case 115200:
 938                 baud = RFCOMM_RPN_BR_115200;
 939                 break;
 940         case 230400:
 941                 baud = RFCOMM_RPN_BR_230400;
 942                 break;
 943         default:
 944                 /* 9600 is standard accordinag to the RFCOMM specification */
 945                 baud = RFCOMM_RPN_BR_9600;
 946                 break;
 947
 948         }
 949
 950         if (changes)
 951                 rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
 952                                 data_bits, stop_bits, parity,
 953                                 RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
 954
 955         return;
 956 }
 957
 958 static void rfcomm_tty_throttle(struct tty_struct *tty)
 959 {
 960         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 961
 962         BT_DBG("tty %p dev %p", tty, dev);
 963
 964         rfcomm_dlc_throttle(dev->dlc);
 965 }
 966
 967 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
 968 {
 969         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 970
 971         BT_DBG("tty %p dev %p", tty, dev);
 972
 973         rfcomm_dlc_unthrottle(dev->dlc);
 974 }
 975
 976 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
 977 {
 978         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 979
 980         BT_DBG("tty %p dev %p", tty, dev);
 981
 982         if (!dev || !dev->dlc)
 983                 return 0;
 984
 985         if (!skb_queue_empty(&dev->dlc->tx_queue))
 986                 return dev->dlc->mtu;
 987
 988         return 0;
 989 }
 990
 991 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
 992 {
 993         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 994
 995         BT_DBG("tty %p dev %p", tty, dev);
 996
 997         if (!dev || !dev->dlc)
 998                 return;
 999
1000         skb_queue_purge(&dev->dlc->tx_queue);
1001         tty_wakeup(tty);
1002 }
1003
1004 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
1005 {
1006         BT_DBG("tty %p ch %c", tty, ch);
1007 }
1008
1009 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1010 {
1011         BT_DBG("tty %p timeout %d", tty, timeout);
1012 }
1013
1014 static void rfcomm_tty_hangup(struct tty_struct *tty)
1015 {
1016         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1017
1018         BT_DBG("tty %p dev %p", tty, dev);
1019
1020         if (!dev)
1021                 return;
1022
1023         rfcomm_tty_flush_buffer(tty);
1024
1025         if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
1026                 if (rfcomm_dev_get(dev->id) == NULL)
1027                         return;
1028                 rfcomm_dev_del(dev);
1029                 rfcomm_dev_put(dev);
1030         }
1031 }
1032
1033 static int rfcomm_tty_read_proc(char *buf, char **start, off_t offset, int len, int *eof, void *unused)
1034 {
1035         return 0;
1036 }
1037
1038 static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
1039 {
1040         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1041
1042         BT_DBG("tty %p dev %p", tty, dev);
1043
1044         return dev->modem_status;
1045 }
1046
1047 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
1048 {
1049         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1050         struct rfcomm_dlc *dlc = dev->dlc;
1051         u8 v24_sig;
1052
1053         BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
1054
1055         rfcomm_dlc_get_modem_status(dlc, &v24_sig);
1056
1057         if (set & TIOCM_DSR || set & TIOCM_DTR)
1058                 v24_sig |= RFCOMM_V24_RTC;
1059         if (set & TIOCM_RTS || set & TIOCM_CTS)
1060                 v24_sig |= RFCOMM_V24_RTR;
1061         if (set & TIOCM_RI)
1062                 v24_sig |= RFCOMM_V24_IC;
1063         if (set & TIOCM_CD)
1064                 v24_sig |= RFCOMM_V24_DV;
1065
1066         if (clear & TIOCM_DSR || clear & TIOCM_DTR)
1067                 v24_sig &= ~RFCOMM_V24_RTC;
1068         if (clear & TIOCM_RTS || clear & TIOCM_CTS)
1069                 v24_sig &= ~RFCOMM_V24_RTR;
1070         if (clear & TIOCM_RI)
1071                 v24_sig &= ~RFCOMM_V24_IC;
1072         if (clear & TIOCM_CD)
1073                 v24_sig &= ~RFCOMM_V24_DV;
1074
1075         rfcomm_dlc_set_modem_status(dlc, v24_sig);
1076
1077         return 0;
1078 }
1079
1080 /* ---- TTY structure ---- */
1081
1082 static const struct tty_operations rfcomm_ops = {
1083         .open                   = rfcomm_tty_open,
1084         .close                  = rfcomm_tty_close,
1085         .write                  = rfcomm_tty_write,
1086         .write_room             = rfcomm_tty_write_room,
1087         .chars_in_buffer        = rfcomm_tty_chars_in_buffer,
1088         .flush_buffer           = rfcomm_tty_flush_buffer,
1089         .ioctl                  = rfcomm_tty_ioctl,
1090         .throttle               = rfcomm_tty_throttle,
1091         .unthrottle             = rfcomm_tty_unthrottle,
1092         .set_termios            = rfcomm_tty_set_termios,
1093         .send_xchar             = rfcomm_tty_send_xchar,
1094         .hangup                 = rfcomm_tty_hangup,
1095         .wait_until_sent        = rfcomm_tty_wait_until_sent,
1096         .read_proc              = rfcomm_tty_read_proc,
1097         .tiocmget               = rfcomm_tty_tiocmget,
1098         .tiocmset               = rfcomm_tty_tiocmset,
1099 };
1100
1101 int rfcomm_init_ttys(void)
1102 {
1103         rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
1104         if (!rfcomm_tty_driver)
1105                 return -1;
1106
1107         rfcomm_tty_driver->owner        = THIS_MODULE;
1108         rfcomm_tty_driver->driver_name  = "rfcomm";
1109         rfcomm_tty_driver->name         = "rfcomm";
1110         rfcomm_tty_driver->major        = RFCOMM_TTY_MAJOR;
1111         rfcomm_tty_driver->minor_start  = RFCOMM_TTY_MINOR;
1112         rfcomm_tty_driver->type         = TTY_DRIVER_TYPE_SERIAL;
1113         rfcomm_tty_driver->subtype      = SERIAL_TYPE_NORMAL;
1114         rfcomm_tty_driver->flags        = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1115         rfcomm_tty_driver->init_termios = tty_std_termios;
1116         rfcomm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1117         tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
1118
1119         if (tty_register_driver(rfcomm_tty_driver)) {
1120                 BT_ERR("Can't register RFCOMM TTY driver");
1121                 put_tty_driver(rfcomm_tty_driver);
1122                 return -1;
1123         }
1124
1125         BT_INFO("RFCOMM TTY layer initialized");
1126
1127         return 0;
1128 }
1129
1130 void rfcomm_cleanup_ttys(void)
1131 {
1132         tty_unregister_driver(rfcomm_tty_driver);
1133         put_tty_driver(rfcomm_tty_driver);
1134 }