kernel/net/irda/irlap.c

   1 /*********************************************************************
   2  *
   3  * Filename:      irlap.c
   4  * Version:       1.0
   5  * Description:   IrLAP implementation for Linux
   6  * Status:        Stable
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Mon Aug  4 20:40:53 1997
   9  * Modified at:   Tue Dec 14 09:26:44 1999
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  *
  12  *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
  13  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
  14  *
  15  *     This program is free software; you can redistribute it and/or
  16  *     modify it under the terms of the GNU General Public License as
  17  *     published by the Free Software Foundation; either version 2 of
  18  *     the License, or (at your option) any later version.
  19  *
  20  *     This program is distributed in the hope that it will be useful,
  21  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  23  *     GNU General Public License for more details.
  24  *
  25  *     You should have received a copy of the GNU General Public License
  26  *     along with this program; if not, see <http://www.gnu.org/licenses/>.
  27  *
  28  ********************************************************************/
  29
  30 #include <linux/slab.h>
  31 #include <linux/string.h>
  32 #include <linux/skbuff.h>
  33 #include <linux/delay.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/init.h>
  36 #include <linux/random.h>
  37 #include <linux/module.h>
  38 #include <linux/seq_file.h>
  39
  40 #include <net/irda/irda.h>
  41 #include <net/irda/irda_device.h>
  42 #include <net/irda/irqueue.h>
  43 #include <net/irda/irlmp.h>
  44 #include <net/irda/irlmp_frame.h>
  45 #include <net/irda/irlap_frame.h>
  46 #include <net/irda/irlap.h>
  47 #include <net/irda/timer.h>
  48 #include <net/irda/qos.h>
  49
  50 static hashbin_t *irlap = NULL;
  51 int sysctl_slot_timeout = SLOT_TIMEOUT * 1000 / HZ;
  52
  53 /* This is the delay of missed pf period before generating an event
  54  * to the application. The spec mandate 3 seconds, but in some cases
  55  * it's way too long. - Jean II */
  56 int sysctl_warn_noreply_time = 3;
  57
  58 extern void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb);
  59 static void __irlap_close(struct irlap_cb *self);
  60 static void irlap_init_qos_capabilities(struct irlap_cb *self,
  61                                         struct qos_info *qos_user);
  62
  63 static const char *const lap_reasons[] __maybe_unused = {
  64         "ERROR, NOT USED",
  65         "LAP_DISC_INDICATION",
  66         "LAP_NO_RESPONSE",
  67         "LAP_RESET_INDICATION",
  68         "LAP_FOUND_NONE",
  69         "LAP_MEDIA_BUSY",
  70         "LAP_PRIMARY_CONFLICT",
  71         "ERROR, NOT USED",
  72 };
  73
  74 int __init irlap_init(void)
  75 {
  76         /* Check if the compiler did its job properly.
  77          * May happen on some ARM configuration, check with Russell King. */
  78         IRDA_ASSERT(sizeof(struct xid_frame) == 14, ;);
  79         IRDA_ASSERT(sizeof(struct test_frame) == 10, ;);
  80         IRDA_ASSERT(sizeof(struct ua_frame) == 10, ;);
  81         IRDA_ASSERT(sizeof(struct snrm_frame) == 11, ;);
  82
  83         /* Allocate master array */
  84         irlap = hashbin_new(HB_LOCK);
  85         if (irlap == NULL) {
  86                 net_err_ratelimited("%s: can't allocate irlap hashbin!\n",
  87                                     __func__);
  88                 return -ENOMEM;
  89         }
  90
  91         return 0;
  92 }
  93
  94 void irlap_cleanup(void)
  95 {
  96         IRDA_ASSERT(irlap != NULL, return;);
  97
  98         hashbin_delete(irlap, (FREE_FUNC) __irlap_close);
  99 }
 100
 101 /*
 102  * Function irlap_open (driver)
 103  *
 104  *    Initialize IrLAP layer
 105  *
 106  */
 107 struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos,
 108                             const char *hw_name)
 109 {
 110         struct irlap_cb *self;
 111
 112         /* Initialize the irlap structure. */
 113         self = kzalloc(sizeof(struct irlap_cb), GFP_KERNEL);
 114         if (self == NULL)
 115                 return NULL;
 116
 117         self->magic = LAP_MAGIC;
 118
 119         /* Make a binding between the layers */
 120         self->netdev = dev;
 121         self->qos_dev = qos;
 122         /* Copy hardware name */
 123         if(hw_name != NULL) {
 124                 strlcpy(self->hw_name, hw_name, sizeof(self->hw_name));
 125         } else {
 126                 self->hw_name[0] = '\0';
 127         }
 128
 129         /* FIXME: should we get our own field? */
 130         dev->atalk_ptr = self;
 131
 132         self->state = LAP_OFFLINE;
 133
 134         /* Initialize transmit queue */
 135         skb_queue_head_init(&self->txq);
 136         skb_queue_head_init(&self->txq_ultra);
 137         skb_queue_head_init(&self->wx_list);
 138
 139         /* My unique IrLAP device address! */
 140         /* We don't want the broadcast address, neither the NULL address
 141          * (most often used to signify "invalid"), and we don't want an
 142          * address already in use (otherwise connect won't be able
 143          * to select the proper link). - Jean II */
 144         do {
 145                 get_random_bytes(&self->saddr, sizeof(self->saddr));
 146         } while ((self->saddr == 0x0) || (self->saddr == BROADCAST) ||
 147                  (hashbin_lock_find(irlap, self->saddr, NULL)) );
 148         /* Copy to the driver */
 149         memcpy(dev->dev_addr, &self->saddr, 4);
 150
 151         init_timer(&self->slot_timer);
 152         init_timer(&self->query_timer);
 153         init_timer(&self->discovery_timer);
 154         init_timer(&self->final_timer);
 155         init_timer(&self->poll_timer);
 156         init_timer(&self->wd_timer);
 157         init_timer(&self->backoff_timer);
 158         init_timer(&self->media_busy_timer);
 159
 160         irlap_apply_default_connection_parameters(self);
 161
 162         self->N3 = 3; /* # connections attempts to try before giving up */
 163
 164         self->state = LAP_NDM;
 165
 166         hashbin_insert(irlap, (irda_queue_t *) self, self->saddr, NULL);
 167
 168         irlmp_register_link(self, self->saddr, &self->notify);
 169
 170         return self;
 171 }
 172 EXPORT_SYMBOL(irlap_open);
 173
 174 /*
 175  * Function __irlap_close (self)
 176  *
 177  *    Remove IrLAP and all allocated memory. Stop any pending timers.
 178  *
 179  */
 180 static void __irlap_close(struct irlap_cb *self)
 181 {
 182         IRDA_ASSERT(self != NULL, return;);
 183         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 184
 185         /* Stop timers */
 186         del_timer(&self->slot_timer);
 187         del_timer(&self->query_timer);
 188         del_timer(&self->discovery_timer);
 189         del_timer(&self->final_timer);
 190         del_timer(&self->poll_timer);
 191         del_timer(&self->wd_timer);
 192         del_timer(&self->backoff_timer);
 193         del_timer(&self->media_busy_timer);
 194
 195         irlap_flush_all_queues(self);
 196
 197         self->magic = 0;
 198
 199         kfree(self);
 200 }
 201
 202 /*
 203  * Function irlap_close (self)
 204  *
 205  *    Remove IrLAP instance
 206  *
 207  */
 208 void irlap_close(struct irlap_cb *self)
 209 {
 210         struct irlap_cb *lap;
 211
 212         IRDA_ASSERT(self != NULL, return;);
 213         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 214
 215         /* We used to send a LAP_DISC_INDICATION here, but this was
 216          * racy. This has been move within irlmp_unregister_link()
 217          * itself. Jean II */
 218
 219         /* Kill the LAP and all LSAPs on top of it */
 220         irlmp_unregister_link(self->saddr);
 221         self->notify.instance = NULL;
 222
 223         /* Be sure that we manage to remove ourself from the hash */
 224         lap = hashbin_remove(irlap, self->saddr, NULL);
 225         if (!lap) {
 226                 pr_debug("%s(), Didn't find myself!\n", __func__);
 227                 return;
 228         }
 229         __irlap_close(lap);
 230 }
 231 EXPORT_SYMBOL(irlap_close);
 232
 233 /*
 234  * Function irlap_connect_indication (self, skb)
 235  *
 236  *    Another device is attempting to make a connection
 237  *
 238  */
 239 void irlap_connect_indication(struct irlap_cb *self, struct sk_buff *skb)
 240 {
 241         IRDA_ASSERT(self != NULL, return;);
 242         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 243
 244         irlap_init_qos_capabilities(self, NULL); /* No user QoS! */
 245
 246         irlmp_link_connect_indication(self->notify.instance, self->saddr,
 247                                       self->daddr, &self->qos_tx, skb);
 248 }
 249
 250 /*
 251  * Function irlap_connect_response (self, skb)
 252  *
 253  *    Service user has accepted incoming connection
 254  *
 255  */
 256 void irlap_connect_response(struct irlap_cb *self, struct sk_buff *userdata)
 257 {
 258         irlap_do_event(self, CONNECT_RESPONSE, userdata, NULL);
 259 }
 260
 261 /*
 262  * Function irlap_connect_request (self, daddr, qos_user, sniff)
 263  *
 264  *    Request connection with another device, sniffing is not implemented
 265  *    yet.
 266  *
 267  */
 268 void irlap_connect_request(struct irlap_cb *self, __u32 daddr,
 269                            struct qos_info *qos_user, int sniff)
 270 {
 271         pr_debug("%s(), daddr=0x%08x\n", __func__, daddr);
 272
 273         IRDA_ASSERT(self != NULL, return;);
 274         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 275
 276         self->daddr = daddr;
 277
 278         /*
 279          *  If the service user specifies QoS values for this connection,
 280          *  then use them
 281          */
 282         irlap_init_qos_capabilities(self, qos_user);
 283
 284         if ((self->state == LAP_NDM) && !self->media_busy)
 285                 irlap_do_event(self, CONNECT_REQUEST, NULL, NULL);
 286         else
 287                 self->connect_pending = TRUE;
 288 }
 289
 290 /*
 291  * Function irlap_connect_confirm (self, skb)
 292  *
 293  *    Connection request has been accepted
 294  *
 295  */
 296 void irlap_connect_confirm(struct irlap_cb *self, struct sk_buff *skb)
 297 {
 298         IRDA_ASSERT(self != NULL, return;);
 299         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 300
 301         irlmp_link_connect_confirm(self->notify.instance, &self->qos_tx, skb);
 302 }
 303
 304 /*
 305  * Function irlap_data_indication (self, skb)
 306  *
 307  *    Received data frames from IR-port, so we just pass them up to
 308  *    IrLMP for further processing
 309  *
 310  */
 311 void irlap_data_indication(struct irlap_cb *self, struct sk_buff *skb,
 312                            int unreliable)
 313 {
 314         /* Hide LAP header from IrLMP layer */
 315         skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
 316
 317         irlmp_link_data_indication(self->notify.instance, skb, unreliable);
 318 }
 319
 320
 321 /*
 322  * Function irlap_data_request (self, skb)
 323  *
 324  *    Queue data for transmission, must wait until XMIT state
 325  *
 326  */
 327 void irlap_data_request(struct irlap_cb *self, struct sk_buff *skb,
 328                         int unreliable)
 329 {
 330         IRDA_ASSERT(self != NULL, return;);
 331         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 332
 333         IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
 334                     return;);
 335         skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
 336
 337         /*
 338          *  Must set frame format now so that the rest of the code knows
 339          *  if its dealing with an I or an UI frame
 340          */
 341         if (unreliable)
 342                 skb->data[1] = UI_FRAME;
 343         else
 344                 skb->data[1] = I_FRAME;
 345
 346         /* Don't forget to refcount it - see irlmp_connect_request(). */
 347         skb_get(skb);
 348
 349         /* Add at the end of the queue (keep ordering) - Jean II */
 350         skb_queue_tail(&self->txq, skb);
 351
 352         /*
 353          *  Send event if this frame only if we are in the right state
 354          *  FIXME: udata should be sent first! (skb_queue_head?)
 355          */
 356         if ((self->state == LAP_XMIT_P) || (self->state == LAP_XMIT_S)) {
 357                 /* If we are not already processing the Tx queue, trigger
 358                  * transmission immediately - Jean II */
 359                 if((skb_queue_len(&self->txq) <= 1) && (!self->local_busy))
 360                         irlap_do_event(self, DATA_REQUEST, skb, NULL);
 361                 /* Otherwise, the packets will be sent normally at the
 362                  * next pf-poll - Jean II */
 363         }
 364 }
 365
 366 /*
 367  * Function irlap_unitdata_request (self, skb)
 368  *
 369  *    Send Ultra data. This is data that must be sent outside any connection
 370  *
 371  */
 372 #ifdef CONFIG_IRDA_ULTRA
 373 void irlap_unitdata_request(struct irlap_cb *self, struct sk_buff *skb)
 374 {
 375         IRDA_ASSERT(self != NULL, return;);
 376         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 377
 378         IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
 379                return;);
 380         skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
 381
 382         skb->data[0] = CBROADCAST;
 383         skb->data[1] = UI_FRAME;
 384
 385         /* Don't need to refcount, see irlmp_connless_data_request() */
 386
 387         skb_queue_tail(&self->txq_ultra, skb);
 388
 389         irlap_do_event(self, SEND_UI_FRAME, NULL, NULL);
 390 }
 391 #endif /*CONFIG_IRDA_ULTRA */
 392
 393 /*
 394  * Function irlap_udata_indication (self, skb)
 395  *
 396  *    Receive Ultra data. This is data that is received outside any connection
 397  *
 398  */
 399 #ifdef CONFIG_IRDA_ULTRA
 400 void irlap_unitdata_indication(struct irlap_cb *self, struct sk_buff *skb)
 401 {
 402         IRDA_ASSERT(self != NULL, return;);
 403         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 404         IRDA_ASSERT(skb != NULL, return;);
 405
 406         /* Hide LAP header from IrLMP layer */
 407         skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
 408
 409         irlmp_link_unitdata_indication(self->notify.instance, skb);
 410 }
 411 #endif /* CONFIG_IRDA_ULTRA */
 412
 413 /*
 414  * Function irlap_disconnect_request (void)
 415  *
 416  *    Request to disconnect connection by service user
 417  */
 418 void irlap_disconnect_request(struct irlap_cb *self)
 419 {
 420         IRDA_ASSERT(self != NULL, return;);
 421         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 422
 423         /* Don't disconnect until all data frames are successfully sent */
 424         if (!skb_queue_empty(&self->txq)) {
 425                 self->disconnect_pending = TRUE;
 426                 return;
 427         }
 428
 429         /* Check if we are in the right state for disconnecting */
 430         switch (self->state) {
 431         case LAP_XMIT_P:        /* FALLTHROUGH */
 432         case LAP_XMIT_S:        /* FALLTHROUGH */
 433         case LAP_CONN:          /* FALLTHROUGH */
 434         case LAP_RESET_WAIT:    /* FALLTHROUGH */
 435         case LAP_RESET_CHECK:
 436                 irlap_do_event(self, DISCONNECT_REQUEST, NULL, NULL);
 437                 break;
 438         default:
 439                 pr_debug("%s(), disconnect pending!\n", __func__);
 440                 self->disconnect_pending = TRUE;
 441                 break;
 442         }
 443 }
 444
 445 /*
 446  * Function irlap_disconnect_indication (void)
 447  *
 448  *    Disconnect request from other device
 449  *
 450  */
 451 void irlap_disconnect_indication(struct irlap_cb *self, LAP_REASON reason)
 452 {
 453         pr_debug("%s(), reason=%s\n", __func__, lap_reasons[reason]);
 454
 455         IRDA_ASSERT(self != NULL, return;);
 456         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 457
 458         /* Flush queues */
 459         irlap_flush_all_queues(self);
 460
 461         switch (reason) {
 462         case LAP_RESET_INDICATION:
 463                 pr_debug("%s(), Sending reset request!\n", __func__);
 464                 irlap_do_event(self, RESET_REQUEST, NULL, NULL);
 465                 break;
 466         case LAP_NO_RESPONSE:      /* FALLTHROUGH */
 467         case LAP_DISC_INDICATION:  /* FALLTHROUGH */
 468         case LAP_FOUND_NONE:       /* FALLTHROUGH */
 469         case LAP_MEDIA_BUSY:
 470                 irlmp_link_disconnect_indication(self->notify.instance, self,
 471                                                  reason, NULL);
 472                 break;
 473         default:
 474                 net_err_ratelimited("%s: Unknown reason %d\n",
 475                                     __func__, reason);
 476         }
 477 }
 478
 479 /*
 480  * Function irlap_discovery_request (gen_addr_bit)
 481  *
 482  *    Start one single discovery operation.
 483  *
 484  */
 485 void irlap_discovery_request(struct irlap_cb *self, discovery_t *discovery)
 486 {
 487         struct irlap_info info;
 488
 489         IRDA_ASSERT(self != NULL, return;);
 490         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 491         IRDA_ASSERT(discovery != NULL, return;);
 492
 493         pr_debug("%s(), nslots = %d\n", __func__, discovery->nslots);
 494
 495         IRDA_ASSERT((discovery->nslots == 1) || (discovery->nslots == 6) ||
 496                     (discovery->nslots == 8) || (discovery->nslots == 16),
 497                     return;);
 498
 499         /* Discovery is only possible in NDM mode */
 500         if (self->state != LAP_NDM) {
 501                 pr_debug("%s(), discovery only possible in NDM mode\n",
 502                          __func__);
 503                 irlap_discovery_confirm(self, NULL);
 504                 /* Note : in theory, if we are not in NDM, we could postpone
 505                  * the discovery like we do for connection request.
 506                  * In practice, it's not worth it. If the media was busy,
 507                  * it's likely next time around it won't be busy. If we are
 508                  * in REPLY state, we will get passive discovery info & event.
 509                  * Jean II */
 510                 return;
 511         }
 512
 513         /* Check if last discovery request finished in time, or if
 514          * it was aborted due to the media busy flag. */
 515         if (self->discovery_log != NULL) {
 516                 hashbin_delete(self->discovery_log, (FREE_FUNC) kfree);
 517                 self->discovery_log = NULL;
 518         }
 519
 520         /* All operations will occur at predictable time, no need to lock */
 521         self->discovery_log = hashbin_new(HB_NOLOCK);
 522
 523         if (self->discovery_log == NULL) {
 524                 net_warn_ratelimited("%s(), Unable to allocate discovery log!\n",
 525                                      __func__);
 526                 return;
 527         }
 528
 529         info.S = discovery->nslots; /* Number of slots */
 530         info.s = 0; /* Current slot */
 531
 532         self->discovery_cmd = discovery;
 533         info.discovery = discovery;
 534
 535         /* sysctl_slot_timeout bounds are checked in irsysctl.c - Jean II */
 536         self->slot_timeout = msecs_to_jiffies(sysctl_slot_timeout);
 537
 538         irlap_do_event(self, DISCOVERY_REQUEST, NULL, &info);
 539 }
 540
 541 /*
 542  * Function irlap_discovery_confirm (log)
 543  *
 544  *    A device has been discovered in front of this station, we
 545  *    report directly to LMP.
 546  */
 547 void irlap_discovery_confirm(struct irlap_cb *self, hashbin_t *discovery_log)
 548 {
 549         IRDA_ASSERT(self != NULL, return;);
 550         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 551
 552         IRDA_ASSERT(self->notify.instance != NULL, return;);
 553
 554         /*
 555          * Check for successful discovery, since we are then allowed to clear
 556          * the media busy condition (IrLAP 6.13.4 - p.94). This should allow
 557          * us to make connection attempts much faster and easier (i.e. no
 558          * collisions).
 559          * Setting media busy to false will also generate an event allowing
 560          * to process pending events in NDM state machine.
 561          * Note : the spec doesn't define what's a successful discovery is.
 562          * If we want Ultra to work, it's successful even if there is
 563          * nobody discovered - Jean II
 564          */
 565         if (discovery_log)
 566                 irda_device_set_media_busy(self->netdev, FALSE);
 567
 568         /* Inform IrLMP */
 569         irlmp_link_discovery_confirm(self->notify.instance, discovery_log);
 570 }
 571
 572 /*
 573  * Function irlap_discovery_indication (log)
 574  *
 575  *    Somebody is trying to discover us!
 576  *
 577  */
 578 void irlap_discovery_indication(struct irlap_cb *self, discovery_t *discovery)
 579 {
 580         IRDA_ASSERT(self != NULL, return;);
 581         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 582         IRDA_ASSERT(discovery != NULL, return;);
 583
 584         IRDA_ASSERT(self->notify.instance != NULL, return;);
 585
 586         /* A device is very likely to connect immediately after it performs
 587          * a successful discovery. This means that in our case, we are much
 588          * more likely to receive a connection request over the medium.
 589          * So, we backoff to avoid collisions.
 590          * IrLAP spec 6.13.4 suggest 100ms...
 591          * Note : this little trick actually make a *BIG* difference. If I set
 592          * my Linux box with discovery enabled and one Ultra frame sent every
 593          * second, my Palm has no trouble connecting to it every time !
 594          * Jean II */
 595         irda_device_set_media_busy(self->netdev, SMALL);
 596
 597         irlmp_link_discovery_indication(self->notify.instance, discovery);
 598 }
 599
 600 /*
 601  * Function irlap_status_indication (quality_of_link)
 602  */
 603 void irlap_status_indication(struct irlap_cb *self, int quality_of_link)
 604 {
 605         switch (quality_of_link) {
 606         case STATUS_NO_ACTIVITY:
 607                 net_info_ratelimited("IrLAP, no activity on link!\n");
 608                 break;
 609         case STATUS_NOISY:
 610                 net_info_ratelimited("IrLAP, noisy link!\n");
 611                 break;
 612         default:
 613                 break;
 614         }
 615         irlmp_status_indication(self->notify.instance,
 616                                 quality_of_link, LOCK_NO_CHANGE);
 617 }
 618
 619 /*
 620  * Function irlap_reset_indication (void)
 621  */
 622 void irlap_reset_indication(struct irlap_cb *self)
 623 {
 624         IRDA_ASSERT(self != NULL, return;);
 625         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 626
 627         if (self->state == LAP_RESET_WAIT)
 628                 irlap_do_event(self, RESET_REQUEST, NULL, NULL);
 629         else
 630                 irlap_do_event(self, RESET_RESPONSE, NULL, NULL);
 631 }
 632
 633 /*
 634  * Function irlap_reset_confirm (void)
 635  */
 636 void irlap_reset_confirm(void)
 637 {
 638 }
 639
 640 /*
 641  * Function irlap_generate_rand_time_slot (S, s)
 642  *
 643  *    Generate a random time slot between s and S-1 where
 644  *    S = Number of slots (0 -> S-1)
 645  *    s = Current slot
 646  */
 647 int irlap_generate_rand_time_slot(int S, int s)
 648 {
 649         static int rand;
 650         int slot;
 651
 652         IRDA_ASSERT((S - s) > 0, return 0;);
 653
 654         rand += jiffies;
 655         rand ^= (rand << 12);
 656         rand ^= (rand >> 20);
 657
 658         slot = s + rand % (S-s);
 659
 660         IRDA_ASSERT((slot >= s) || (slot < S), return 0;);
 661
 662         return slot;
 663 }
 664
 665 /*
 666  * Function irlap_update_nr_received (nr)
 667  *
 668  *    Remove all acknowledged frames in current window queue. This code is
 669  *    not intuitive and you should not try to change it. If you think it
 670  *    contains bugs, please mail a patch to the author instead.
 671  */
 672 void irlap_update_nr_received(struct irlap_cb *self, int nr)
 673 {
 674         struct sk_buff *skb = NULL;
 675         int count = 0;
 676
 677         /*
 678          * Remove all the ack-ed frames from the window queue.
 679          */
 680
 681         /*
 682          *  Optimize for the common case. It is most likely that the receiver
 683          *  will acknowledge all the frames we have sent! So in that case we
 684          *  delete all frames stored in window.
 685          */
 686         if (nr == self->vs) {
 687                 while ((skb = skb_dequeue(&self->wx_list)) != NULL) {
 688                         dev_kfree_skb(skb);
 689                 }
 690                 /* The last acked frame is the next to send minus one */
 691                 self->va = nr - 1;
 692         } else {
 693                 /* Remove all acknowledged frames in current window */
 694                 while ((skb_peek(&self->wx_list) != NULL) &&
 695                        (((self->va+1) % 8) != nr))
 696                 {
 697                         skb = skb_dequeue(&self->wx_list);
 698                         dev_kfree_skb(skb);
 699
 700                         self->va = (self->va + 1) % 8;
 701                         count++;
 702                 }
 703         }
 704
 705         /* Advance window */
 706         self->window = self->window_size - skb_queue_len(&self->wx_list);
 707 }
 708
 709 /*
 710  * Function irlap_validate_ns_received (ns)
 711  *
 712  *    Validate the next to send (ns) field from received frame.
 713  */
 714 int irlap_validate_ns_received(struct irlap_cb *self, int ns)
 715 {
 716         /*  ns as expected?  */
 717         if (ns == self->vr)
 718                 return NS_EXPECTED;
 719         /*
 720          *  Stations are allowed to treat invalid NS as unexpected NS
 721          *  IrLAP, Recv ... with-invalid-Ns. p. 84
 722          */
 723         return NS_UNEXPECTED;
 724
 725         /* return NR_INVALID; */
 726 }
 727 /*
 728  * Function irlap_validate_nr_received (nr)
 729  *
 730  *    Validate the next to receive (nr) field from received frame.
 731  *
 732  */
 733 int irlap_validate_nr_received(struct irlap_cb *self, int nr)
 734 {
 735         /*  nr as expected?  */
 736         if (nr == self->vs) {
 737                 pr_debug("%s(), expected!\n", __func__);
 738                 return NR_EXPECTED;
 739         }
 740
 741         /*
 742          *  unexpected nr? (but within current window), first we check if the
 743          *  ns numbers of the frames in the current window wrap.
 744          */
 745         if (self->va < self->vs) {
 746                 if ((nr >= self->va) && (nr <= self->vs))
 747                         return NR_UNEXPECTED;
 748         } else {
 749                 if ((nr >= self->va) || (nr <= self->vs))
 750                         return NR_UNEXPECTED;
 751         }
 752
 753         /* Invalid nr!  */
 754         return NR_INVALID;
 755 }
 756
 757 /*
 758  * Function irlap_initiate_connection_state ()
 759  *
 760  *    Initialize the connection state parameters
 761  *
 762  */
 763 void irlap_initiate_connection_state(struct irlap_cb *self)
 764 {
 765         IRDA_ASSERT(self != NULL, return;);
 766         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 767
 768         /* Next to send and next to receive */
 769         self->vs = self->vr = 0;
 770
 771         /* Last frame which got acked (0 - 1) % 8 */
 772         self->va = 7;
 773
 774         self->window = 1;
 775
 776         self->remote_busy = FALSE;
 777         self->retry_count = 0;
 778 }
 779
 780 /*
 781  * Function irlap_wait_min_turn_around (self, qos)
 782  *
 783  *    Wait negotiated minimum turn around time, this function actually sets
 784  *    the number of BOS's that must be sent before the next transmitted
 785  *    frame in order to delay for the specified amount of time. This is
 786  *    done to avoid using timers, and the forbidden udelay!
 787  */
 788 void irlap_wait_min_turn_around(struct irlap_cb *self, struct qos_info *qos)
 789 {
 790         __u32 min_turn_time;
 791         __u32 speed;
 792
 793         /* Get QoS values.  */
 794         speed = qos->baud_rate.value;
 795         min_turn_time = qos->min_turn_time.value;
 796
 797         /* No need to calculate XBOFs for speeds over 115200 bps */
 798         if (speed > 115200) {
 799                 self->mtt_required = min_turn_time;
 800                 return;
 801         }
 802
 803         /*
 804          *  Send additional BOF's for the next frame for the requested
 805          *  min turn time, so now we must calculate how many chars (XBOF's) we
 806          *  must send for the requested time period (min turn time)
 807          */
 808         self->xbofs_delay = irlap_min_turn_time_in_bytes(speed, min_turn_time);
 809 }
 810
 811 /*
 812  * Function irlap_flush_all_queues (void)
 813  *
 814  *    Flush all queues
 815  *
 816  */
 817 void irlap_flush_all_queues(struct irlap_cb *self)
 818 {
 819         struct sk_buff* skb;
 820
 821         IRDA_ASSERT(self != NULL, return;);
 822         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 823
 824         /* Free transmission queue */
 825         while ((skb = skb_dequeue(&self->txq)) != NULL)
 826                 dev_kfree_skb(skb);
 827
 828         while ((skb = skb_dequeue(&self->txq_ultra)) != NULL)
 829                 dev_kfree_skb(skb);
 830
 831         /* Free sliding window buffered packets */
 832         while ((skb = skb_dequeue(&self->wx_list)) != NULL)
 833                 dev_kfree_skb(skb);
 834 }
 835
 836 /*
 837  * Function irlap_setspeed (self, speed)
 838  *
 839  *    Change the speed of the IrDA port
 840  *
 841  */
 842 static void irlap_change_speed(struct irlap_cb *self, __u32 speed, int now)
 843 {
 844         struct sk_buff *skb;
 845
 846         pr_debug("%s(), setting speed to %d\n", __func__, speed);
 847
 848         IRDA_ASSERT(self != NULL, return;);
 849         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 850
 851         self->speed = speed;
 852
 853         /* Change speed now, or just piggyback speed on frames */
 854         if (now) {
 855                 /* Send down empty frame to trigger speed change */
 856                 skb = alloc_skb(0, GFP_ATOMIC);
 857                 if (skb)
 858                         irlap_queue_xmit(self, skb);
 859         }
 860 }
 861
 862 /*
 863  * Function irlap_init_qos_capabilities (self, qos)
 864  *
 865  *    Initialize QoS for this IrLAP session, What we do is to compute the
 866  *    intersection of the QoS capabilities for the user, driver and for
 867  *    IrLAP itself. Normally, IrLAP will not specify any values, but it can
 868  *    be used to restrict certain values.
 869  */
 870 static void irlap_init_qos_capabilities(struct irlap_cb *self,
 871                                         struct qos_info *qos_user)
 872 {
 873         IRDA_ASSERT(self != NULL, return;);
 874         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 875         IRDA_ASSERT(self->netdev != NULL, return;);
 876
 877         /* Start out with the maximum QoS support possible */
 878         irda_init_max_qos_capabilies(&self->qos_rx);
 879
 880         /* Apply drivers QoS capabilities */
 881         irda_qos_compute_intersection(&self->qos_rx, self->qos_dev);
 882
 883         /*
 884          *  Check for user supplied QoS parameters. The service user is only
 885          *  allowed to supply these values. We check each parameter since the
 886          *  user may not have set all of them.
 887          */
 888         if (qos_user) {
 889                 pr_debug("%s(), Found user specified QoS!\n", __func__);
 890
 891                 if (qos_user->baud_rate.bits)
 892                         self->qos_rx.baud_rate.bits &= qos_user->baud_rate.bits;
 893
 894                 if (qos_user->max_turn_time.bits)
 895                         self->qos_rx.max_turn_time.bits &= qos_user->max_turn_time.bits;
 896                 if (qos_user->data_size.bits)
 897                         self->qos_rx.data_size.bits &= qos_user->data_size.bits;
 898
 899                 if (qos_user->link_disc_time.bits)
 900                         self->qos_rx.link_disc_time.bits &= qos_user->link_disc_time.bits;
 901         }
 902
 903         /* Use 500ms in IrLAP for now */
 904         self->qos_rx.max_turn_time.bits &= 0x01;
 905
 906         /* Set data size */
 907         /*self->qos_rx.data_size.bits &= 0x03;*/
 908
 909         irda_qos_bits_to_value(&self->qos_rx);
 910 }
 911
 912 /*
 913  * Function irlap_apply_default_connection_parameters (void, now)
 914  *
 915  *    Use the default connection and transmission parameters
 916  */
 917 void irlap_apply_default_connection_parameters(struct irlap_cb *self)
 918 {
 919         IRDA_ASSERT(self != NULL, return;);
 920         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 921
 922         /* xbofs : Default value in NDM */
 923         self->next_bofs   = 12;
 924         self->bofs_count  = 12;
 925
 926         /* NDM Speed is 9600 */
 927         irlap_change_speed(self, 9600, TRUE);
 928
 929         /* Set mbusy when going to NDM state */
 930         irda_device_set_media_busy(self->netdev, TRUE);
 931
 932         /*
 933          * Generate random connection address for this session, which must
 934          * be 7 bits wide and different from 0x00 and 0xfe
 935          */
 936         while ((self->caddr == 0x00) || (self->caddr == 0xfe)) {
 937                 get_random_bytes(&self->caddr, sizeof(self->caddr));
 938                 self->caddr &= 0xfe;
 939         }
 940
 941         /* Use default values until connection has been negitiated */
 942         self->slot_timeout = sysctl_slot_timeout;
 943         self->final_timeout = FINAL_TIMEOUT;
 944         self->poll_timeout = POLL_TIMEOUT;
 945         self->wd_timeout = WD_TIMEOUT;
 946
 947         /* Set some default values */
 948         self->qos_tx.baud_rate.value = 9600;
 949         self->qos_rx.baud_rate.value = 9600;
 950         self->qos_tx.max_turn_time.value = 0;
 951         self->qos_rx.max_turn_time.value = 0;
 952         self->qos_tx.min_turn_time.value = 0;
 953         self->qos_rx.min_turn_time.value = 0;
 954         self->qos_tx.data_size.value = 64;
 955         self->qos_rx.data_size.value = 64;
 956         self->qos_tx.window_size.value = 1;
 957         self->qos_rx.window_size.value = 1;
 958         self->qos_tx.additional_bofs.value = 12;
 959         self->qos_rx.additional_bofs.value = 12;
 960         self->qos_tx.link_disc_time.value = 0;
 961         self->qos_rx.link_disc_time.value = 0;
 962
 963         irlap_flush_all_queues(self);
 964
 965         self->disconnect_pending = FALSE;
 966         self->connect_pending = FALSE;
 967 }
 968
 969 /*
 970  * Function irlap_apply_connection_parameters (qos, now)
 971  *
 972  *    Initialize IrLAP with the negotiated QoS values
 973  *
 974  * If 'now' is false, the speed and xbofs will be changed after the next
 975  * frame is sent.
 976  * If 'now' is true, the speed and xbofs is changed immediately
 977  */
 978 void irlap_apply_connection_parameters(struct irlap_cb *self, int now)
 979 {
 980         IRDA_ASSERT(self != NULL, return;);
 981         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 982
 983         /* Set the negotiated xbofs value */
 984         self->next_bofs   = self->qos_tx.additional_bofs.value;
 985         if (now)
 986                 self->bofs_count = self->next_bofs;
 987
 988         /* Set the negotiated link speed (may need the new xbofs value) */
 989         irlap_change_speed(self, self->qos_tx.baud_rate.value, now);
 990
 991         self->window_size = self->qos_tx.window_size.value;
 992         self->window      = self->qos_tx.window_size.value;
 993
 994 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 995         /*
 996          *  Calculate how many bytes it is possible to transmit before the
 997          *  link must be turned around
 998          */
 999         self->line_capacity =
1000                 irlap_max_line_capacity(self->qos_tx.baud_rate.value,
1001                                         self->qos_tx.max_turn_time.value);
1002         self->bytes_left = self->line_capacity;
1003 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1004
1005
1006         /*
1007          *  Initialize timeout values, some of the rules are listed on
1008          *  page 92 in IrLAP.
1009          */
1010         IRDA_ASSERT(self->qos_tx.max_turn_time.value != 0, return;);
1011         IRDA_ASSERT(self->qos_rx.max_turn_time.value != 0, return;);
1012         /* The poll timeout applies only to the primary station.
1013          * It defines the maximum time the primary stay in XMIT mode
1014          * before timeout and turning the link around (sending a RR).
1015          * Or, this is how much we can keep the pf bit in primary mode.
1016          * Therefore, it must be lower or equal than our *OWN* max turn around.
1017          * Jean II */
1018         self->poll_timeout = msecs_to_jiffies(
1019                                 self->qos_tx.max_turn_time.value);
1020         /* The Final timeout applies only to the primary station.
1021          * It defines the maximum time the primary wait (mostly in RECV mode)
1022          * for an answer from the secondary station before polling it again.
1023          * Therefore, it must be greater or equal than our *PARTNER*
1024          * max turn around time - Jean II */
1025         self->final_timeout = msecs_to_jiffies(
1026                                 self->qos_rx.max_turn_time.value);
1027         /* The Watchdog Bit timeout applies only to the secondary station.
1028          * It defines the maximum time the secondary wait (mostly in RECV mode)
1029          * for poll from the primary station before getting annoyed.
1030          * Therefore, it must be greater or equal than our *PARTNER*
1031          * max turn around time - Jean II */
1032         self->wd_timeout = self->final_timeout * 2;
1033
1034         /*
1035          * N1 and N2 are maximum retry count for *both* the final timer
1036          * and the wd timer (with a factor 2) as defined above.
1037          * After N1 retry of a timer, we give a warning to the user.
1038          * After N2 retry, we consider the link dead and disconnect it.
1039          * Jean II
1040          */
1041
1042         /*
1043          *  Set N1 to 0 if Link Disconnect/Threshold Time = 3 and set it to
1044          *  3 seconds otherwise. See page 71 in IrLAP for more details.
1045          *  Actually, it's not always 3 seconds, as we allow to set
1046          *  it via sysctl... Max maxtt is 500ms, and N1 need to be multiple
1047          *  of 2, so 1 second is minimum we can allow. - Jean II
1048          */
1049         if (self->qos_tx.link_disc_time.value == sysctl_warn_noreply_time)
1050                 /*
1051                  * If we set N1 to 0, it will trigger immediately, which is
1052                  * not what we want. What we really want is to disable it,
1053                  * Jean II
1054                  */
1055                 self->N1 = -2; /* Disable - Need to be multiple of 2*/
1056         else
1057                 self->N1 = sysctl_warn_noreply_time * 1000 /
1058                   self->qos_rx.max_turn_time.value;
1059
1060         pr_debug("Setting N1 = %d\n", self->N1);
1061
1062         /* Set N2 to match our own disconnect time */
1063         self->N2 = self->qos_tx.link_disc_time.value * 1000 /
1064                 self->qos_rx.max_turn_time.value;
1065         pr_debug("Setting N2 = %d\n", self->N2);
1066 }
1067
1068 #ifdef CONFIG_PROC_FS
1069 struct irlap_iter_state {
1070         int id;
1071 };
1072
1073 static void *irlap_seq_start(struct seq_file *seq, loff_t *pos)
1074 {
1075         struct irlap_iter_state *iter = seq->private;
1076         struct irlap_cb *self;
1077
1078         /* Protect our access to the tsap list */
1079         spin_lock_irq(&irlap->hb_spinlock);
1080         iter->id = 0;
1081
1082         for (self = (struct irlap_cb *) hashbin_get_first(irlap);
1083              self; self = (struct irlap_cb *) hashbin_get_next(irlap)) {
1084                 if (iter->id == *pos)
1085                         break;
1086                 ++iter->id;
1087         }
1088
1089         return self;
1090 }
1091
1092 static void *irlap_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1093 {
1094         struct irlap_iter_state *iter = seq->private;
1095
1096         ++*pos;
1097         ++iter->id;
1098         return (void *) hashbin_get_next(irlap);
1099 }
1100
1101 static void irlap_seq_stop(struct seq_file *seq, void *v)
1102 {
1103         spin_unlock_irq(&irlap->hb_spinlock);
1104 }
1105
1106 static int irlap_seq_show(struct seq_file *seq, void *v)
1107 {
1108         const struct irlap_iter_state *iter = seq->private;
1109         const struct irlap_cb *self = v;
1110
1111         IRDA_ASSERT(self->magic == LAP_MAGIC, return -EINVAL;);
1112
1113         seq_printf(seq, "irlap%d ", iter->id);
1114         seq_printf(seq, "state: %s\n",
1115                    irlap_state[self->state]);
1116
1117         seq_printf(seq, "  device name: %s, ",
1118                    (self->netdev) ? self->netdev->name : "bug");
1119         seq_printf(seq, "hardware name: %s\n", self->hw_name);
1120
1121         seq_printf(seq, "  caddr: %#02x, ", self->caddr);
1122         seq_printf(seq, "saddr: %#08x, ", self->saddr);
1123         seq_printf(seq, "daddr: %#08x\n", self->daddr);
1124
1125         seq_printf(seq, "  win size: %d, ",
1126                    self->window_size);
1127         seq_printf(seq, "win: %d, ", self->window);
1128 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1129         seq_printf(seq, "line capacity: %d, ",
1130                    self->line_capacity);
1131         seq_printf(seq, "bytes left: %d\n", self->bytes_left);
1132 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1133         seq_printf(seq, "  tx queue len: %d ",
1134                    skb_queue_len(&self->txq));
1135         seq_printf(seq, "win queue len: %d ",
1136                    skb_queue_len(&self->wx_list));
1137         seq_printf(seq, "rbusy: %s", self->remote_busy ?
1138                    "TRUE" : "FALSE");
1139         seq_printf(seq, " mbusy: %s\n", self->media_busy ?
1140                    "TRUE" : "FALSE");
1141
1142         seq_printf(seq, "  retrans: %d ", self->retry_count);
1143         seq_printf(seq, "vs: %d ", self->vs);
1144         seq_printf(seq, "vr: %d ", self->vr);
1145         seq_printf(seq, "va: %d\n", self->va);
1146
1147         seq_printf(seq, "  qos\tbps\tmaxtt\tdsize\twinsize\taddbofs\tmintt\tldisc\tcomp\n");
1148
1149         seq_printf(seq, "  tx\t%d\t",
1150                    self->qos_tx.baud_rate.value);
1151         seq_printf(seq, "%d\t",
1152                    self->qos_tx.max_turn_time.value);
1153         seq_printf(seq, "%d\t",
1154                    self->qos_tx.data_size.value);
1155         seq_printf(seq, "%d\t",
1156                    self->qos_tx.window_size.value);
1157         seq_printf(seq, "%d\t",
1158                    self->qos_tx.additional_bofs.value);
1159         seq_printf(seq, "%d\t",
1160                    self->qos_tx.min_turn_time.value);
1161         seq_printf(seq, "%d\t",
1162                    self->qos_tx.link_disc_time.value);
1163         seq_printf(seq, "\n");
1164
1165         seq_printf(seq, "  rx\t%d\t",
1166                    self->qos_rx.baud_rate.value);
1167         seq_printf(seq, "%d\t",
1168                    self->qos_rx.max_turn_time.value);
1169         seq_printf(seq, "%d\t",
1170                    self->qos_rx.data_size.value);
1171         seq_printf(seq, "%d\t",
1172                    self->qos_rx.window_size.value);
1173         seq_printf(seq, "%d\t",
1174                    self->qos_rx.additional_bofs.value);
1175         seq_printf(seq, "%d\t",
1176                    self->qos_rx.min_turn_time.value);
1177         seq_printf(seq, "%d\n",
1178                    self->qos_rx.link_disc_time.value);
1179
1180         return 0;
1181 }
1182
1183 static const struct seq_operations irlap_seq_ops = {
1184         .start  = irlap_seq_start,
1185         .next   = irlap_seq_next,
1186         .stop   = irlap_seq_stop,
1187         .show   = irlap_seq_show,
1188 };
1189
1190 static int irlap_seq_open(struct inode *inode, struct file *file)
1191 {
1192         if (irlap == NULL)
1193                 return -EINVAL;
1194
1195         return seq_open_private(file, &irlap_seq_ops,
1196                         sizeof(struct irlap_iter_state));
1197 }
1198
1199 const struct file_operations irlap_seq_fops = {
1200         .owner          = THIS_MODULE,
1201         .open           = irlap_seq_open,
1202         .read           = seq_read,
1203         .llseek         = seq_lseek,
1204         .release        = seq_release_private,
1205 };
1206
1207 #endif /* CONFIG_PROC_FS */