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
 621         if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
 622                 (tty->ldisc.write_wakeup)(tty);
 623
 624         wake_up_interruptible(&tty->write_wait);
 625 #ifdef SERIAL_HAVE_POLL_WAIT
 626         wake_up_interruptible(&tty->poll_wait);
 627 #endif
 628 }
 629
 630 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
 631 {
 632         DECLARE_WAITQUEUE(wait, current);
 633         struct rfcomm_dev *dev;
 634         struct rfcomm_dlc *dlc;
 635         int err, id;
 636
 637         id = tty->index;
 638
 639         BT_DBG("tty %p id %d", tty, id);
 640
 641         /* We don't leak this refcount. For reasons which are not entirely
 642            clear, the TTY layer will call our ->close() method even if the
 643            open fails. We decrease the refcount there, and decreasing it
 644            here too would cause breakage. */
 645         dev = rfcomm_dev_get(id);
 646         if (!dev)
 647                 return -ENODEV;
 648
 649         BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst), dev->channel, dev->opened);
 650
 651         if (dev->opened++ != 0)
 652                 return 0;
 653
 654         dlc = dev->dlc;
 655
 656         /* Attach TTY and open DLC */
 657
 658         rfcomm_dlc_lock(dlc);
 659         tty->driver_data = dev;
 660         dev->tty = tty;
 661         rfcomm_dlc_unlock(dlc);
 662         set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 663
 664         err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
 665         if (err < 0)
 666                 return err;
 667
 668         /* Wait for DLC to connect */
 669         add_wait_queue(&dev->wait, &wait);
 670         while (1) {
 671                 set_current_state(TASK_INTERRUPTIBLE);
 672
 673                 if (dlc->state == BT_CLOSED) {
 674                         err = -dev->err;
 675                         break;
 676                 }
 677
 678                 if (dlc->state == BT_CONNECTED)
 679                         break;
 680
 681                 if (signal_pending(current)) {
 682                         err = -EINTR;
 683                         break;
 684                 }
 685
 686                 schedule();
 687         }
 688         set_current_state(TASK_RUNNING);
 689         remove_wait_queue(&dev->wait, &wait);
 690
 691         if (err == 0)
 692                 device_move(dev->tty_dev, rfcomm_get_device(dev));
 693
 694         return err;
 695 }
 696
 697 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 698 {
 699         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 700         if (!dev)
 701                 return;
 702
 703         BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc, dev->opened);
 704
 705         if (--dev->opened == 0) {
 706                 if (dev->tty_dev->parent)
 707                         device_move(dev->tty_dev, NULL);
 708
 709                 /* Close DLC and dettach TTY */
 710                 rfcomm_dlc_close(dev->dlc, 0);
 711
 712                 clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 713                 tasklet_kill(&dev->wakeup_task);
 714
 715                 rfcomm_dlc_lock(dev->dlc);
 716                 tty->driver_data = NULL;
 717                 dev->tty = NULL;
 718                 rfcomm_dlc_unlock(dev->dlc);
 719         }
 720
 721         rfcomm_dev_put(dev);
 722 }
 723
 724 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 725 {
 726         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 727         struct rfcomm_dlc *dlc = dev->dlc;
 728         struct sk_buff *skb;
 729         int err = 0, sent = 0, size;
 730
 731         BT_DBG("tty %p count %d", tty, count);
 732
 733         while (count) {
 734                 size = min_t(uint, count, dlc->mtu);
 735
 736                 skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
 737
 738                 if (!skb)
 739                         break;
 740
 741                 skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
 742
 743                 memcpy(skb_put(skb, size), buf + sent, size);
 744
 745                 if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
 746                         kfree_skb(skb);
 747                         break;
 748                 }
 749
 750                 sent  += size;
 751                 count -= size;
 752         }
 753
 754         return sent ? sent : err;
 755 }
 756
 757 static int rfcomm_tty_write_room(struct tty_struct *tty)
 758 {
 759         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 760         int room;
 761
 762         BT_DBG("tty %p", tty);
 763
 764         if (!dev || !dev->dlc)
 765                 return 0;
 766
 767         room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
 768         if (room < 0)
 769                 room = 0;
 770
 771         return room;
 772 }
 773
 774 static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
 775 {
 776         BT_DBG("tty %p cmd 0x%02x", tty, cmd);
 777
 778         switch (cmd) {
 779         case TCGETS:
 780                 BT_DBG("TCGETS is not supported");
 781                 return -ENOIOCTLCMD;
 782
 783         case TCSETS:
 784                 BT_DBG("TCSETS is not supported");
 785                 return -ENOIOCTLCMD;
 786
 787         case TIOCMIWAIT:
 788                 BT_DBG("TIOCMIWAIT");
 789                 break;
 790
 791         case TIOCGICOUNT:
 792                 BT_DBG("TIOCGICOUNT");
 793                 break;
 794
 795         case TIOCGSERIAL:
 796                 BT_ERR("TIOCGSERIAL is not supported");
 797                 return -ENOIOCTLCMD;
 798
 799         case TIOCSSERIAL:
 800                 BT_ERR("TIOCSSERIAL is not supported");
 801                 return -ENOIOCTLCMD;
 802
 803         case TIOCSERGSTRUCT:
 804                 BT_ERR("TIOCSERGSTRUCT is not supported");
 805                 return -ENOIOCTLCMD;
 806
 807         case TIOCSERGETLSR:
 808                 BT_ERR("TIOCSERGETLSR is not supported");
 809                 return -ENOIOCTLCMD;
 810
 811         case TIOCSERCONFIG:
 812                 BT_ERR("TIOCSERCONFIG is not supported");
 813                 return -ENOIOCTLCMD;
 814
 815         default:
 816                 return -ENOIOCTLCMD;    /* ioctls which we must ignore */
 817
 818         }
 819
 820         return -ENOIOCTLCMD;
 821 }
 822
 823 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 824 {
 825         struct ktermios *new = tty->termios;
 826         int old_baud_rate = tty_termios_baud_rate(old);
 827         int new_baud_rate = tty_termios_baud_rate(new);
 828
 829         u8 baud, data_bits, stop_bits, parity, x_on, x_off;
 830         u16 changes = 0;
 831
 832         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 833
 834         BT_DBG("tty %p termios %p", tty, old);
 835
 836         if (!dev || !dev->dlc || !dev->dlc->session)
 837                 return;
 838
 839         /* Handle turning off CRTSCTS */
 840         if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
 841                 BT_DBG("Turning off CRTSCTS unsupported");
 842
 843         /* Parity on/off and when on, odd/even */
 844         if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
 845                         ((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
 846                 changes |= RFCOMM_RPN_PM_PARITY;
 847                 BT_DBG("Parity change detected.");
 848         }
 849
 850         /* Mark and space parity are not supported! */
 851         if (new->c_cflag & PARENB) {
 852                 if (new->c_cflag & PARODD) {
 853                         BT_DBG("Parity is ODD");
 854                         parity = RFCOMM_RPN_PARITY_ODD;
 855                 } else {
 856                         BT_DBG("Parity is EVEN");
 857                         parity = RFCOMM_RPN_PARITY_EVEN;
 858                 }
 859         } else {
 860                 BT_DBG("Parity is OFF");
 861                 parity = RFCOMM_RPN_PARITY_NONE;
 862         }
 863
 864         /* Setting the x_on / x_off characters */
 865         if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
 866                 BT_DBG("XOFF custom");
 867                 x_on = new->c_cc[VSTOP];
 868                 changes |= RFCOMM_RPN_PM_XON;
 869         } else {
 870                 BT_DBG("XOFF default");
 871                 x_on = RFCOMM_RPN_XON_CHAR;
 872         }
 873
 874         if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
 875                 BT_DBG("XON custom");
 876                 x_off = new->c_cc[VSTART];
 877                 changes |= RFCOMM_RPN_PM_XOFF;
 878         } else {
 879                 BT_DBG("XON default");
 880                 x_off = RFCOMM_RPN_XOFF_CHAR;
 881         }
 882
 883         /* Handle setting of stop bits */
 884         if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
 885                 changes |= RFCOMM_RPN_PM_STOP;
 886
 887         /* POSIX does not support 1.5 stop bits and RFCOMM does not
 888          * support 2 stop bits. So a request for 2 stop bits gets
 889          * translated to 1.5 stop bits */
 890         if (new->c_cflag & CSTOPB) {
 891                 stop_bits = RFCOMM_RPN_STOP_15;
 892         } else {
 893                 stop_bits = RFCOMM_RPN_STOP_1;
 894         }
 895
 896         /* Handle number of data bits [5-8] */
 897         if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
 898                 changes |= RFCOMM_RPN_PM_DATA;
 899
 900         switch (new->c_cflag & CSIZE) {
 901         case CS5:
 902                 data_bits = RFCOMM_RPN_DATA_5;
 903                 break;
 904         case CS6:
 905                 data_bits = RFCOMM_RPN_DATA_6;
 906                 break;
 907         case CS7:
 908                 data_bits = RFCOMM_RPN_DATA_7;
 909                 break;
 910         case CS8:
 911                 data_bits = RFCOMM_RPN_DATA_8;
 912                 break;
 913         default:
 914                 data_bits = RFCOMM_RPN_DATA_8;
 915                 break;
 916         }
 917
 918         /* Handle baudrate settings */
 919         if (old_baud_rate != new_baud_rate)
 920                 changes |= RFCOMM_RPN_PM_BITRATE;
 921
 922         switch (new_baud_rate) {
 923         case 2400:
 924                 baud = RFCOMM_RPN_BR_2400;
 925                 break;
 926         case 4800:
 927                 baud = RFCOMM_RPN_BR_4800;
 928                 break;
 929         case 7200:
 930                 baud = RFCOMM_RPN_BR_7200;
 931                 break;
 932         case 9600:
 933                 baud = RFCOMM_RPN_BR_9600;
 934                 break;
 935         case 19200:
 936                 baud = RFCOMM_RPN_BR_19200;
 937                 break;
 938         case 38400:
 939                 baud = RFCOMM_RPN_BR_38400;
 940                 break;
 941         case 57600:
 942                 baud = RFCOMM_RPN_BR_57600;
 943                 break;
 944         case 115200:
 945                 baud = RFCOMM_RPN_BR_115200;
 946                 break;
 947         case 230400:
 948                 baud = RFCOMM_RPN_BR_230400;
 949                 break;
 950         default:
 951                 /* 9600 is standard accordinag to the RFCOMM specification */
 952                 baud = RFCOMM_RPN_BR_9600;
 953                 break;
 954
 955         }
 956
 957         if (changes)
 958                 rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
 959                                 data_bits, stop_bits, parity,
 960                                 RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
 961
 962         return;
 963 }
 964
 965 static void rfcomm_tty_throttle(struct tty_struct *tty)
 966 {
 967         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 968
 969         BT_DBG("tty %p dev %p", tty, dev);
 970
 971         rfcomm_dlc_throttle(dev->dlc);
 972 }
 973
 974 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
 975 {
 976         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 977
 978         BT_DBG("tty %p dev %p", tty, dev);
 979
 980         rfcomm_dlc_unthrottle(dev->dlc);
 981 }
 982
 983 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
 984 {
 985         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 986
 987         BT_DBG("tty %p dev %p", tty, dev);
 988
 989         if (!dev || !dev->dlc)
 990                 return 0;
 991
 992         if (!skb_queue_empty(&dev->dlc->tx_queue))
 993                 return dev->dlc->mtu;
 994
 995         return 0;
 996 }
 997
 998 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
 999 {
1000         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1001
1002         BT_DBG("tty %p dev %p", tty, dev);
1003
1004         if (!dev || !dev->dlc)
1005                 return;
1006
1007         skb_queue_purge(&dev->dlc->tx_queue);
1008
1009         if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
1010                 tty->ldisc.write_wakeup(tty);
1011 }
1012
1013 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
1014 {
1015         BT_DBG("tty %p ch %c", tty, ch);
1016 }
1017
1018 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1019 {
1020         BT_DBG("tty %p timeout %d", tty, timeout);
1021 }
1022
1023 static void rfcomm_tty_hangup(struct tty_struct *tty)
1024 {
1025         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1026
1027         BT_DBG("tty %p dev %p", tty, dev);
1028
1029         if (!dev)
1030                 return;
1031
1032         rfcomm_tty_flush_buffer(tty);
1033
1034         if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
1035                 if (rfcomm_dev_get(dev->id) == NULL)
1036                         return;
1037                 rfcomm_dev_del(dev);
1038                 rfcomm_dev_put(dev);
1039         }
1040 }
1041
1042 static int rfcomm_tty_read_proc(char *buf, char **start, off_t offset, int len, int *eof, void *unused)
1043 {
1044         return 0;
1045 }
1046
1047 static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
1048 {
1049         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1050
1051         BT_DBG("tty %p dev %p", tty, dev);
1052
1053         return dev->modem_status;
1054 }
1055
1056 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
1057 {
1058         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1059         struct rfcomm_dlc *dlc = dev->dlc;
1060         u8 v24_sig;
1061
1062         BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
1063
1064         rfcomm_dlc_get_modem_status(dlc, &v24_sig);
1065
1066         if (set & TIOCM_DSR || set & TIOCM_DTR)
1067                 v24_sig |= RFCOMM_V24_RTC;
1068         if (set & TIOCM_RTS || set & TIOCM_CTS)
1069                 v24_sig |= RFCOMM_V24_RTR;
1070         if (set & TIOCM_RI)
1071                 v24_sig |= RFCOMM_V24_IC;
1072         if (set & TIOCM_CD)
1073                 v24_sig |= RFCOMM_V24_DV;
1074
1075         if (clear & TIOCM_DSR || clear & TIOCM_DTR)
1076                 v24_sig &= ~RFCOMM_V24_RTC;
1077         if (clear & TIOCM_RTS || clear & TIOCM_CTS)
1078                 v24_sig &= ~RFCOMM_V24_RTR;
1079         if (clear & TIOCM_RI)
1080                 v24_sig &= ~RFCOMM_V24_IC;
1081         if (clear & TIOCM_CD)
1082                 v24_sig &= ~RFCOMM_V24_DV;
1083
1084         rfcomm_dlc_set_modem_status(dlc, v24_sig);
1085
1086         return 0;
1087 }
1088
1089 /* ---- TTY structure ---- */
1090
1091 static const struct tty_operations rfcomm_ops = {
1092         .open                   = rfcomm_tty_open,
1093         .close                  = rfcomm_tty_close,
1094         .write                  = rfcomm_tty_write,
1095         .write_room             = rfcomm_tty_write_room,
1096         .chars_in_buffer        = rfcomm_tty_chars_in_buffer,
1097         .flush_buffer           = rfcomm_tty_flush_buffer,
1098         .ioctl                  = rfcomm_tty_ioctl,
1099         .throttle               = rfcomm_tty_throttle,
1100         .unthrottle             = rfcomm_tty_unthrottle,
1101         .set_termios            = rfcomm_tty_set_termios,
1102         .send_xchar             = rfcomm_tty_send_xchar,
1103         .hangup                 = rfcomm_tty_hangup,
1104         .wait_until_sent        = rfcomm_tty_wait_until_sent,
1105         .read_proc              = rfcomm_tty_read_proc,
1106         .tiocmget               = rfcomm_tty_tiocmget,
1107         .tiocmset               = rfcomm_tty_tiocmset,
1108 };
1109
1110 int rfcomm_init_ttys(void)
1111 {
1112         rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
1113         if (!rfcomm_tty_driver)
1114                 return -1;
1115
1116         rfcomm_tty_driver->owner        = THIS_MODULE;
1117         rfcomm_tty_driver->driver_name  = "rfcomm";
1118         rfcomm_tty_driver->name         = "rfcomm";
1119         rfcomm_tty_driver->major        = RFCOMM_TTY_MAJOR;
1120         rfcomm_tty_driver->minor_start  = RFCOMM_TTY_MINOR;
1121         rfcomm_tty_driver->type         = TTY_DRIVER_TYPE_SERIAL;
1122         rfcomm_tty_driver->subtype      = SERIAL_TYPE_NORMAL;
1123         rfcomm_tty_driver->flags        = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1124         rfcomm_tty_driver->init_termios = tty_std_termios;
1125         rfcomm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1126         tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
1127
1128         if (tty_register_driver(rfcomm_tty_driver)) {
1129                 BT_ERR("Can't register RFCOMM TTY driver");
1130                 put_tty_driver(rfcomm_tty_driver);
1131                 return -1;
1132         }
1133
1134         BT_INFO("RFCOMM TTY layer initialized");
1135
1136         return 0;
1137 }
1138
1139 void rfcomm_cleanup_ttys(void)
1140 {
1141         tty_unregister_driver(rfcomm_tty_driver);
1142         put_tty_driver(rfcomm_tty_driver);
1143 }