net/irda/irlap_event.c

   1 /*********************************************************************
   2  *
   3  * Filename:      irlap_event.c
   4  * Version:       0.9
   5  * Description:   IrLAP state machine implementation
   6  * Status:        Experimental.
   7  * Author:        Dag Brattli <dag@brattli.net>
   8  * Created at:    Sat Aug 16 00:59:29 1997
   9  * Modified at:   Sat Dec 25 21:07:57 1999
  10  * Modified by:   Dag Brattli <dag@brattli.net>
  11  *
  12  *     Copyright (c) 1998-2000 Dag Brattli <dag@brattli.net>,
  13  *     Copyright (c) 1998      Thomas Davis <ratbert@radiks.net>
  14  *     All Rights Reserved.
  15  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
  16  *
  17  *     This program is free software; you can redistribute it and/or
  18  *     modify it under the terms of the GNU General Public License as
  19  *     published by the Free Software Foundation; either version 2 of
  20  *     the License, or (at your option) any later version.
  21  *
  22  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  23  *     provide warranty for any of this software. This material is
  24  *     provided "AS-IS" and at no charge.
  25  *
  26  ********************************************************************/
  27
  28 #include <linux/string.h>
  29 #include <linux/kernel.h>
  30 #include <linux/delay.h>
  31 #include <linux/skbuff.h>
  32
  33 #include <net/irda/irda.h>
  34 #include <net/irda/irlap_event.h>
  35
  36 #include <net/irda/timer.h>
  37 #include <net/irda/irlap.h>
  38 #include <net/irda/irlap_frame.h>
  39 #include <net/irda/qos.h>
  40 #include <net/irda/parameters.h>
  41 #include <net/irda/irlmp.h>             /* irlmp_flow_indication(), ... */
  42
  43 #include <net/irda/irda_device.h>
  44
  45 #ifdef CONFIG_IRDA_FAST_RR
  46 int sysctl_fast_poll_increase = 50;
  47 #endif
  48
  49 static int irlap_state_ndm    (struct irlap_cb *self, IRLAP_EVENT event,
  50                                struct sk_buff *skb, struct irlap_info *info);
  51 static int irlap_state_query  (struct irlap_cb *self, IRLAP_EVENT event,
  52                                struct sk_buff *skb, struct irlap_info *info);
  53 static int irlap_state_reply  (struct irlap_cb *self, IRLAP_EVENT event,
  54                                struct sk_buff *skb, struct irlap_info *info);
  55 static int irlap_state_conn   (struct irlap_cb *self, IRLAP_EVENT event,
  56                                struct sk_buff *skb, struct irlap_info *info);
  57 static int irlap_state_setup  (struct irlap_cb *self, IRLAP_EVENT event,
  58                                struct sk_buff *skb, struct irlap_info *info);
  59 static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
  60                                struct sk_buff *skb, struct irlap_info *info);
  61 static int irlap_state_xmit_p (struct irlap_cb *self, IRLAP_EVENT event,
  62                                struct sk_buff *skb, struct irlap_info *info);
  63 static int irlap_state_pclose (struct irlap_cb *self, IRLAP_EVENT event,
  64                                struct sk_buff *skb, struct irlap_info *info);
  65 static int irlap_state_nrm_p  (struct irlap_cb *self, IRLAP_EVENT event,
  66                                struct sk_buff *skb, struct irlap_info *info);
  67 static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
  68                                   struct sk_buff *skb, struct irlap_info *info);
  69 static int irlap_state_reset  (struct irlap_cb *self, IRLAP_EVENT event,
  70                                struct sk_buff *skb, struct irlap_info *info);
  71 static int irlap_state_nrm_s  (struct irlap_cb *self, IRLAP_EVENT event,
  72                                struct sk_buff *skb, struct irlap_info *info);
  73 static int irlap_state_xmit_s (struct irlap_cb *self, IRLAP_EVENT event,
  74                                struct sk_buff *skb, struct irlap_info *info);
  75 static int irlap_state_sclose (struct irlap_cb *self, IRLAP_EVENT event,
  76                                struct sk_buff *skb, struct irlap_info *info);
  77 static int irlap_state_reset_check(struct irlap_cb *, IRLAP_EVENT event,
  78                                    struct sk_buff *, struct irlap_info *);
  79
  80 #ifdef CONFIG_IRDA_DEBUG
  81 static const char *irlap_event[] = {
  82         "DISCOVERY_REQUEST",
  83         "CONNECT_REQUEST",
  84         "CONNECT_RESPONSE",
  85         "DISCONNECT_REQUEST",
  86         "DATA_REQUEST",
  87         "RESET_REQUEST",
  88         "RESET_RESPONSE",
  89         "SEND_I_CMD",
  90         "SEND_UI_FRAME",
  91         "RECV_DISCOVERY_XID_CMD",
  92         "RECV_DISCOVERY_XID_RSP",
  93         "RECV_SNRM_CMD",
  94         "RECV_TEST_CMD",
  95         "RECV_TEST_RSP",
  96         "RECV_UA_RSP",
  97         "RECV_DM_RSP",
  98         "RECV_RD_RSP",
  99         "RECV_I_CMD",
 100         "RECV_I_RSP",
 101         "RECV_UI_FRAME",
 102         "RECV_FRMR_RSP",
 103         "RECV_RR_CMD",
 104         "RECV_RR_RSP",
 105         "RECV_RNR_CMD",
 106         "RECV_RNR_RSP",
 107         "RECV_REJ_CMD",
 108         "RECV_REJ_RSP",
 109         "RECV_SREJ_CMD",
 110         "RECV_SREJ_RSP",
 111         "RECV_DISC_CMD",
 112         "SLOT_TIMER_EXPIRED",
 113         "QUERY_TIMER_EXPIRED",
 114         "FINAL_TIMER_EXPIRED",
 115         "POLL_TIMER_EXPIRED",
 116         "DISCOVERY_TIMER_EXPIRED",
 117         "WD_TIMER_EXPIRED",
 118         "BACKOFF_TIMER_EXPIRED",
 119         "MEDIA_BUSY_TIMER_EXPIRED",
 120 };
 121 #endif  /* CONFIG_IRDA_DEBUG */
 122
 123 const char *irlap_state[] = {
 124         "LAP_NDM",
 125         "LAP_QUERY",
 126         "LAP_REPLY",
 127         "LAP_CONN",
 128         "LAP_SETUP",
 129         "LAP_OFFLINE",
 130         "LAP_XMIT_P",
 131         "LAP_PCLOSE",
 132         "LAP_NRM_P",
 133         "LAP_RESET_WAIT",
 134         "LAP_RESET",
 135         "LAP_NRM_S",
 136         "LAP_XMIT_S",
 137         "LAP_SCLOSE",
 138         "LAP_RESET_CHECK",
 139 };
 140
 141 static int (*state[])(struct irlap_cb *self, IRLAP_EVENT event,
 142                       struct sk_buff *skb, struct irlap_info *info) =
 143 {
 144         irlap_state_ndm,
 145         irlap_state_query,
 146         irlap_state_reply,
 147         irlap_state_conn,
 148         irlap_state_setup,
 149         irlap_state_offline,
 150         irlap_state_xmit_p,
 151         irlap_state_pclose,
 152         irlap_state_nrm_p,
 153         irlap_state_reset_wait,
 154         irlap_state_reset,
 155         irlap_state_nrm_s,
 156         irlap_state_xmit_s,
 157         irlap_state_sclose,
 158         irlap_state_reset_check,
 159 };
 160
 161 /*
 162  * Function irda_poll_timer_expired (data)
 163  *
 164  *    Poll timer has expired. Normally we must now send a RR frame to the
 165  *    remote device
 166  */
 167 static void irlap_poll_timer_expired(void *data)
 168 {
 169         struct irlap_cb *self = (struct irlap_cb *) data;
 170
 171         IRDA_ASSERT(self != NULL, return;);
 172         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 173
 174         irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
 175 }
 176
 177 /*
 178  * Calculate and set time before we will have to send back the pf bit
 179  * to the peer. Use in primary.
 180  * Make sure that state is XMIT_P/XMIT_S when calling this function
 181  * (and that nobody messed up with the state). - Jean II
 182  */
 183 static void irlap_start_poll_timer(struct irlap_cb *self, int timeout)
 184 {
 185         IRDA_ASSERT(self != NULL, return;);
 186         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 187
 188 #ifdef CONFIG_IRDA_FAST_RR
 189         /*
 190          * Send out the RR frames faster if our own transmit queue is empty, or
 191          * if the peer is busy. The effect is a much faster conversation
 192          */
 193         if (skb_queue_empty(&self->txq) || self->remote_busy) {
 194                 if (self->fast_RR == TRUE) {
 195                         /*
 196                          *  Assert that the fast poll timer has not reached the
 197                          *  normal poll timer yet
 198                          */
 199                         if (self->fast_RR_timeout < timeout) {
 200                                 /*
 201                                  *  FIXME: this should be a more configurable
 202                                  *         function
 203                                  */
 204                                 self->fast_RR_timeout +=
 205                                         (sysctl_fast_poll_increase * HZ/1000);
 206
 207                                 /* Use this fast(er) timeout instead */
 208                                 timeout = self->fast_RR_timeout;
 209                         }
 210                 } else {
 211                         self->fast_RR = TRUE;
 212
 213                         /* Start with just 0 ms */
 214                         self->fast_RR_timeout = 0;
 215                         timeout = 0;
 216                 }
 217         } else
 218                 self->fast_RR = FALSE;
 219
 220         IRDA_DEBUG(3, "%s(), timeout=%d (%ld)\n", __FUNCTION__, timeout, jiffies);
 221 #endif /* CONFIG_IRDA_FAST_RR */
 222
 223         if (timeout == 0)
 224                 irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
 225         else
 226                 irda_start_timer(&self->poll_timer, timeout, self,
 227                                  irlap_poll_timer_expired);
 228 }
 229
 230 /*
 231  * Function irlap_do_event (event, skb, info)
 232  *
 233  *    Rushes through the state machine without any delay. If state == XMIT
 234  *    then send queued data frames.
 235  */
 236 void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event,
 237                     struct sk_buff *skb, struct irlap_info *info)
 238 {
 239         int ret;
 240
 241         if (!self || self->magic != LAP_MAGIC)
 242                 return;
 243
 244         IRDA_DEBUG(3, "%s(), event = %s, state = %s\n", __FUNCTION__,
 245                    irlap_event[event], irlap_state[self->state]);
 246
 247         ret = (*state[self->state])(self, event, skb, info);
 248
 249         /*
 250          *  Check if there are any pending events that needs to be executed
 251          */
 252         switch (self->state) {
 253         case LAP_XMIT_P: /* FALLTHROUGH */
 254         case LAP_XMIT_S:
 255                 /*
 256                  * We just received the pf bit and are at the beginning
 257                  * of a new LAP transmit window.
 258                  * Check if there are any queued data frames, and do not
 259                  * try to disconnect link if we send any data frames, since
 260                  * that will change the state away form XMIT
 261                  */
 262                 IRDA_DEBUG(2, "%s() : queue len = %d\n", __FUNCTION__,
 263                            skb_queue_len(&self->txq));
 264
 265                 if (!skb_queue_empty(&self->txq)) {
 266                         /* Prevent race conditions with irlap_data_request() */
 267                         self->local_busy = TRUE;
 268
 269                         /* Theory of operation.
 270                          * We send frames up to when we fill the window or
 271                          * reach line capacity. Those frames will queue up
 272                          * in the device queue, and the driver will slowly
 273                          * send them.
 274                          * After each frame that we send, we poll the higher
 275                          * layer for more data. It's the right time to do
 276                          * that because the link layer need to perform the mtt
 277                          * and then send the first frame, so we can afford
 278                          * to send a bit of time in kernel space.
 279                          * The explicit flow indication allow to minimise
 280                          * buffers (== lower latency), to avoid higher layer
 281                          * polling via timers (== less context switches) and
 282                          * to implement a crude scheduler - Jean II */
 283
 284                         /* Try to send away all queued data frames */
 285                         while ((skb = skb_dequeue(&self->txq)) != NULL) {
 286                                 /* Send one frame */
 287                                 ret = (*state[self->state])(self, SEND_I_CMD,
 288                                                             skb, NULL);
 289                                 /* Drop reference count.
 290                                  * It will be increase as needed in
 291                                  * irlap_send_data_xxx() */
 292                                 kfree_skb(skb);
 293
 294                                 /* Poll the higher layers for one more frame */
 295                                 irlmp_flow_indication(self->notify.instance,
 296                                                       FLOW_START);
 297
 298                                 if (ret == -EPROTO)
 299                                         break; /* Try again later! */
 300                         }
 301                         /* Finished transmitting */
 302                         self->local_busy = FALSE;
 303                 } else if (self->disconnect_pending) {
 304                         self->disconnect_pending = FALSE;
 305
 306                         ret = (*state[self->state])(self, DISCONNECT_REQUEST,
 307                                                     NULL, NULL);
 308                 }
 309                 break;
 310 /*      case LAP_NDM: */
 311 /*      case LAP_CONN: */
 312 /*      case LAP_RESET_WAIT: */
 313 /*      case LAP_RESET_CHECK: */
 314         default:
 315                 break;
 316         }
 317 }
 318
 319 /*
 320  * Function irlap_state_ndm (event, skb, frame)
 321  *
 322  *    NDM (Normal Disconnected Mode) state
 323  *
 324  */
 325 static int irlap_state_ndm(struct irlap_cb *self, IRLAP_EVENT event,
 326                            struct sk_buff *skb, struct irlap_info *info)
 327 {
 328         discovery_t *discovery_rsp;
 329         int ret = 0;
 330
 331         IRDA_ASSERT(self != NULL, return -1;);
 332         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 333
 334         switch (event) {
 335         case CONNECT_REQUEST:
 336                 IRDA_ASSERT(self->netdev != NULL, return -1;);
 337
 338                 if (self->media_busy) {
 339                         /* Note : this will never happen, because we test
 340                          * media busy in irlap_connect_request() and
 341                          * postpone the event... - Jean II */
 342                         IRDA_DEBUG(0, "%s(), CONNECT_REQUEST: media busy!\n",
 343                                    __FUNCTION__);
 344
 345                         /* Always switch state before calling upper layers */
 346                         irlap_next_state(self, LAP_NDM);
 347
 348                         irlap_disconnect_indication(self, LAP_MEDIA_BUSY);
 349                 } else {
 350                         irlap_send_snrm_frame(self, &self->qos_rx);
 351
 352                         /* Start Final-bit timer */
 353                         irlap_start_final_timer(self, self->final_timeout);
 354
 355                         self->retry_count = 0;
 356                         irlap_next_state(self, LAP_SETUP);
 357                 }
 358                 break;
 359         case RECV_SNRM_CMD:
 360                 /* Check if the frame contains and I field */
 361                 if (info) {
 362                         self->daddr = info->daddr;
 363                         self->caddr = info->caddr;
 364
 365                         irlap_next_state(self, LAP_CONN);
 366
 367                         irlap_connect_indication(self, skb);
 368                 } else {
 369                         IRDA_DEBUG(0, "%s(), SNRM frame does not "
 370                                    "contain an I field!\n", __FUNCTION__);
 371                 }
 372                 break;
 373         case DISCOVERY_REQUEST:
 374                 IRDA_ASSERT(info != NULL, return -1;);
 375
 376                 if (self->media_busy) {
 377                         IRDA_DEBUG(1, "%s(), DISCOVERY_REQUEST: media busy!\n",
 378                                    __FUNCTION__);
 379                         /* irlap->log.condition = MEDIA_BUSY; */
 380
 381                         /* This will make IrLMP try again */
 382                         irlap_discovery_confirm(self, NULL);
 383                         /* Note : the discovery log is not cleaned up here,
 384                          * it will be done in irlap_discovery_request()
 385                          * Jean II */
 386                         return 0;
 387                 }
 388
 389                 self->S = info->S;
 390                 self->s = info->s;
 391                 irlap_send_discovery_xid_frame(self, info->S, info->s, TRUE,
 392                                                info->discovery);
 393                 self->frame_sent = FALSE;
 394                 self->s++;
 395
 396                 irlap_start_slot_timer(self, self->slot_timeout);
 397                 irlap_next_state(self, LAP_QUERY);
 398                 break;
 399         case RECV_DISCOVERY_XID_CMD:
 400                 IRDA_ASSERT(info != NULL, return -1;);
 401
 402                 /* Assert that this is not the final slot */
 403                 if (info->s <= info->S) {
 404                         self->slot = irlap_generate_rand_time_slot(info->S,
 405                                                                    info->s);
 406                         if (self->slot == info->s) {
 407                                 discovery_rsp = irlmp_get_discovery_response();
 408                                 discovery_rsp->data.daddr = info->daddr;
 409
 410                                 irlap_send_discovery_xid_frame(self, info->S,
 411                                                                self->slot,
 412                                                                FALSE,
 413                                                                discovery_rsp);
 414                                 self->frame_sent = TRUE;
 415                         } else
 416                                 self->frame_sent = FALSE;
 417
 418                         /*
 419                          * Go to reply state until end of discovery to
 420                          * inhibit our own transmissions. Set the timer
 421                          * to not stay forever there... Jean II
 422                          */
 423                         irlap_start_query_timer(self, info->S, info->s);
 424                         irlap_next_state(self, LAP_REPLY);
 425                 } else {
 426                 /* This is the final slot. How is it possible ?
 427                  * This would happen is both discoveries are just slightly
 428                  * offset (if they are in sync, all packets are lost).
 429                  * Most often, all the discovery requests will be received
 430                  * in QUERY state (see my comment there), except for the
 431                  * last frame that will come here.
 432                  * The big trouble when it happen is that active discovery
 433                  * doesn't happen, because nobody answer the discoveries
 434                  * frame of the other guy, so the log shows up empty.
 435                  * What should we do ?
 436                  * Not much. It's too late to answer those discovery frames,
 437                  * so we just pass the info to IrLMP who will put it in the
 438                  * log (and post an event).
 439                  * Another cause would be devices that do discovery much
 440                  * slower than us, however the latest fixes should minimise
 441                  * those cases...
 442                  * Jean II
 443                  */
 444                         IRDA_DEBUG(1, "%s(), Receiving final discovery request, missed the discovery slots :-(\n", __FUNCTION__);
 445
 446                         /* Last discovery request -> in the log */
 447                         irlap_discovery_indication(self, info->discovery);
 448                 }
 449                 break;
 450         case MEDIA_BUSY_TIMER_EXPIRED:
 451                 /* A bunch of events may be postponed because the media is
 452                  * busy (usually immediately after we close a connection),
 453                  * or while we are doing discovery (state query/reply).
 454                  * In all those cases, the media busy flag will be cleared
 455                  * when it's OK for us to process those postponed events.
 456                  * This event is not mentioned in the state machines in the
 457                  * IrLAP spec. It's because they didn't consider Ultra and
 458                  * postponing connection request is optional.
 459                  * Jean II */
 460 #ifdef CONFIG_IRDA_ULTRA
 461                 /* Send any pending Ultra frames if any */
 462                 if (!skb_queue_empty(&self->txq_ultra)) {
 463                         /* We don't send the frame, just post an event.
 464                          * Also, previously this code was in timer.c...
 465                          * Jean II */
 466                         ret = (*state[self->state])(self, SEND_UI_FRAME,
 467                                                     NULL, NULL);
 468                 }
 469 #endif /* CONFIG_IRDA_ULTRA */
 470                 /* Check if we should try to connect.
 471                  * This code was previously in irlap_do_event() */
 472                 if (self->connect_pending) {
 473                         self->connect_pending = FALSE;
 474
 475                         /* This one *should* not pend in this state, except
 476                          * if a socket try to connect and immediately
 477                          * disconnect. - clear - Jean II */
 478                         if (self->disconnect_pending)
 479                                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
 480                         else
 481                                 ret = (*state[self->state])(self,
 482                                                             CONNECT_REQUEST,
 483                                                             NULL, NULL);
 484                         self->disconnect_pending = FALSE;
 485                 }
 486                 /* Note : one way to test if this code works well (including
 487                  * media busy and small busy) is to create a user space
 488                  * application generating an Ultra packet every 3.05 sec (or
 489                  * 2.95 sec) and to see how it interact with discovery.
 490                  * It's fairly easy to check that no packet is lost, that the
 491                  * packets are postponed during discovery and that after
 492                  * discovery indication you have a 100ms "gap".
 493                  * As connection request and Ultra are now processed the same
 494                  * way, this avoid the tedious job of trying IrLAP connection
 495                  * in all those cases...
 496                  * Jean II */
 497                 break;
 498 #ifdef CONFIG_IRDA_ULTRA
 499         case SEND_UI_FRAME:
 500         {
 501                 int i;
 502                 /* Only allowed to repeat an operation twice */
 503                 for (i=0; ((i<2) && (self->media_busy == FALSE)); i++) {
 504                         skb = skb_dequeue(&self->txq_ultra);
 505                         if (skb)
 506                                 irlap_send_ui_frame(self, skb, CBROADCAST,
 507                                                     CMD_FRAME);
 508                         else
 509                                 break;
 510                         /* irlap_send_ui_frame() won't increase skb reference
 511                          * count, so no dev_kfree_skb() - Jean II */
 512                 }
 513                 if (i == 2) {
 514                         /* Force us to listen 500 ms again */
 515                         irda_device_set_media_busy(self->netdev, TRUE);
 516                 }
 517                 break;
 518         }
 519         case RECV_UI_FRAME:
 520                 /* Only accept broadcast frames in NDM mode */
 521                 if (info->caddr != CBROADCAST) {
 522                         IRDA_DEBUG(0, "%s(), not a broadcast frame!\n",
 523                                    __FUNCTION__);
 524                 } else
 525                         irlap_unitdata_indication(self, skb);
 526                 break;
 527 #endif /* CONFIG_IRDA_ULTRA */
 528         case RECV_TEST_CMD:
 529                 /* Remove test frame header */
 530                 skb_pull(skb, sizeof(struct test_frame));
 531
 532                 /*
 533                  * Send response. This skb will not be sent out again, and
 534                  * will only be used to send out the same info as the cmd
 535                  */
 536                 irlap_send_test_frame(self, CBROADCAST, info->daddr, skb);
 537                 break;
 538         case RECV_TEST_RSP:
 539                 IRDA_DEBUG(0, "%s() not implemented!\n", __FUNCTION__);
 540                 break;
 541         default:
 542                 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
 543                            irlap_event[event]);
 544
 545                 ret = -1;
 546                 break;
 547         }
 548         return ret;
 549 }
 550
 551 /*
 552  * Function irlap_state_query (event, skb, info)
 553  *
 554  *    QUERY state
 555  *
 556  */
 557 static int irlap_state_query(struct irlap_cb *self, IRLAP_EVENT event,
 558                              struct sk_buff *skb, struct irlap_info *info)
 559 {
 560         int ret = 0;
 561
 562         IRDA_ASSERT(self != NULL, return -1;);
 563         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 564
 565         switch (event) {
 566         case RECV_DISCOVERY_XID_RSP:
 567                 IRDA_ASSERT(info != NULL, return -1;);
 568                 IRDA_ASSERT(info->discovery != NULL, return -1;);
 569
 570                 IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__,
 571                            info->discovery->data.daddr);
 572
 573                 if (!self->discovery_log) {
 574                         IRDA_WARNING("%s: discovery log is gone! "
 575                                      "maybe the discovery timeout has been set"
 576                                      " too short?\n", __FUNCTION__);
 577                         break;
 578                 }
 579                 hashbin_insert(self->discovery_log,
 580                                (irda_queue_t *) info->discovery,
 581                                info->discovery->data.daddr, NULL);
 582
 583                 /* Keep state */
 584                 /* irlap_next_state(self, LAP_QUERY);  */
 585
 586                 break;
 587         case RECV_DISCOVERY_XID_CMD:
 588                 /* Yes, it is possible to receive those frames in this mode.
 589                  * Note that most often the last discovery request won't
 590                  * occur here but in NDM state (see my comment there).
 591                  * What should we do ?
 592                  * Not much. We are currently performing our own discovery,
 593                  * therefore we can't answer those frames. We don't want
 594                  * to change state either. We just pass the info to
 595                  * IrLMP who will put it in the log (and post an event).
 596                  * Jean II
 597                  */
 598
 599                 IRDA_ASSERT(info != NULL, return -1;);
 600
 601                 IRDA_DEBUG(1, "%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __FUNCTION__, info->s);
 602
 603                 /* Last discovery request ? */
 604                 if (info->s == 0xff)
 605                         irlap_discovery_indication(self, info->discovery);
 606                 break;
 607         case SLOT_TIMER_EXPIRED:
 608                 /*
 609                  * Wait a little longer if we detect an incoming frame. This
 610                  * is not mentioned in the spec, but is a good thing to do,
 611                  * since we want to work even with devices that violate the
 612                  * timing requirements.
 613                  */
 614                 if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
 615                         IRDA_DEBUG(2, "%s(), device is slow to answer, "
 616                                    "waiting some more!\n", __FUNCTION__);
 617                         irlap_start_slot_timer(self, msecs_to_jiffies(10));
 618                         self->add_wait = TRUE;
 619                         return ret;
 620                 }
 621                 self->add_wait = FALSE;
 622
 623                 if (self->s < self->S) {
 624                         irlap_send_discovery_xid_frame(self, self->S,
 625                                                        self->s, TRUE,
 626                                                        self->discovery_cmd);
 627                         self->s++;
 628                         irlap_start_slot_timer(self, self->slot_timeout);
 629
 630                         /* Keep state */
 631                         irlap_next_state(self, LAP_QUERY);
 632                 } else {
 633                         /* This is the final slot! */
 634                         irlap_send_discovery_xid_frame(self, self->S, 0xff,
 635                                                        TRUE,
 636                                                        self->discovery_cmd);
 637
 638                         /* Always switch state before calling upper layers */
 639                         irlap_next_state(self, LAP_NDM);
 640
 641                         /*
 642                          *  We are now finished with the discovery procedure,
 643                          *  so now we must return the results
 644                          */
 645                         irlap_discovery_confirm(self, self->discovery_log);
 646
 647                         /* IrLMP should now have taken care of the log */
 648                         self->discovery_log = NULL;
 649                 }
 650                 break;
 651         default:
 652                 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
 653                            irlap_event[event]);
 654
 655                 ret = -1;
 656                 break;
 657         }
 658         return ret;
 659 }
 660
 661 /*
 662  * Function irlap_state_reply (self, event, skb, info)
 663  *
 664  *    REPLY, we have received a XID discovery frame from a device and we
 665  *    are waiting for the right time slot to send a response XID frame
 666  *
 667  */
 668 static int irlap_state_reply(struct irlap_cb *self, IRLAP_EVENT event,
 669                              struct sk_buff *skb, struct irlap_info *info)
 670 {
 671         discovery_t *discovery_rsp;
 672         int ret=0;
 673
 674         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 675
 676         IRDA_ASSERT(self != NULL, return -1;);
 677         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 678
 679         switch (event) {
 680         case QUERY_TIMER_EXPIRED:
 681                 IRDA_DEBUG(0, "%s(), QUERY_TIMER_EXPIRED <%ld>\n",
 682                            __FUNCTION__, jiffies);
 683                 irlap_next_state(self, LAP_NDM);
 684                 break;
 685         case RECV_DISCOVERY_XID_CMD:
 686                 IRDA_ASSERT(info != NULL, return -1;);
 687                 /* Last frame? */
 688                 if (info->s == 0xff) {
 689                         del_timer(&self->query_timer);
 690
 691                         /* info->log.condition = REMOTE; */
 692
 693                         /* Always switch state before calling upper layers */
 694                         irlap_next_state(self, LAP_NDM);
 695
 696                         irlap_discovery_indication(self, info->discovery);
 697                 } else {
 698                         /* If it's our slot, send our reply */
 699                         if ((info->s >= self->slot) && (!self->frame_sent)) {
 700                                 discovery_rsp = irlmp_get_discovery_response();
 701                                 discovery_rsp->data.daddr = info->daddr;
 702
 703                                 irlap_send_discovery_xid_frame(self, info->S,
 704                                                                self->slot,
 705                                                                FALSE,
 706                                                                discovery_rsp);
 707
 708                                 self->frame_sent = TRUE;
 709                         }
 710                         /* Readjust our timer to accomodate devices
 711                          * doing faster or slower discovery than us...
 712                          * Jean II */
 713                         irlap_start_query_timer(self, info->S, info->s);
 714
 715                         /* Keep state */
 716                         //irlap_next_state(self, LAP_REPLY);
 717                 }
 718                 break;
 719         default:
 720                 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
 721                            event, irlap_event[event]);
 722
 723                 ret = -1;
 724                 break;
 725         }
 726         return ret;
 727 }
 728
 729 /*
 730  * Function irlap_state_conn (event, skb, info)
 731  *
 732  *    CONN, we have received a SNRM command and is waiting for the upper
 733  *    layer to accept or refuse connection
 734  *
 735  */
 736 static int irlap_state_conn(struct irlap_cb *self, IRLAP_EVENT event,
 737                             struct sk_buff *skb, struct irlap_info *info)
 738 {
 739         int ret = 0;
 740
 741         IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[ event]);
 742
 743         IRDA_ASSERT(self != NULL, return -1;);
 744         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 745
 746         switch (event) {
 747         case CONNECT_RESPONSE:
 748                 skb_pull(skb, sizeof(struct snrm_frame));
 749
 750                 IRDA_ASSERT(self->netdev != NULL, return -1;);
 751
 752                 irlap_qos_negotiate(self, skb);
 753
 754                 irlap_initiate_connection_state(self);
 755
 756                 /*
 757                  * Applying the parameters now will make sure we change speed
 758                  * *after* we have sent the next frame
 759                  */
 760                 irlap_apply_connection_parameters(self, FALSE);
 761
 762                 /*
 763                  * Sending this frame will force a speed change after it has
 764                  * been sent (i.e. the frame will be sent at 9600).
 765                  */
 766                 irlap_send_ua_response_frame(self, &self->qos_rx);
 767
 768 #if 0
 769                 /*
 770                  * We are allowed to send two frames, but this may increase
 771                  * the connect latency, so lets not do it for now.
 772                  */
 773                 /* This is full of good intentions, but doesn't work in
 774                  * practice.
 775                  * After sending the first UA response, we switch the
 776                  * dongle to the negotiated speed, which is usually
 777                  * different than 9600 kb/s.
 778                  * From there, there is two solutions :
 779                  * 1) The other end has received the first UA response :
 780                  * it will set up the connection, move to state LAP_NRM_P,
 781                  * and will ignore and drop the second UA response.
 782                  * Actually, it's even worse : the other side will almost
 783                  * immediately send a RR that will likely collide with the
 784                  * UA response (depending on negotiated turnaround).
 785                  * 2) The other end has not received the first UA response,
 786                  * will stay at 9600 and will never see the second UA response.
 787                  * Jean II */
 788                 irlap_send_ua_response_frame(self, &self->qos_rx);
 789 #endif
 790
 791                 /*
 792                  *  The WD-timer could be set to the duration of the P-timer
 793                  *  for this case, but it is recommended to use twice the
 794                  *  value (note 3 IrLAP p. 60).
 795                  */
 796                 irlap_start_wd_timer(self, self->wd_timeout);
 797                 irlap_next_state(self, LAP_NRM_S);
 798
 799                 break;
 800         case RECV_DISCOVERY_XID_CMD:
 801                 IRDA_DEBUG(3, "%s(), event RECV_DISCOVER_XID_CMD!\n",
 802                            __FUNCTION__);
 803                 irlap_next_state(self, LAP_NDM);
 804
 805                 break;
 806         case DISCONNECT_REQUEST:
 807                 IRDA_DEBUG(0, "%s(), Disconnect request!\n", __FUNCTION__);
 808                 irlap_send_dm_frame(self);
 809                 irlap_next_state( self, LAP_NDM);
 810                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
 811                 break;
 812         default:
 813                 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
 814                            event, irlap_event[event]);
 815
 816                 ret = -1;
 817                 break;
 818         }
 819
 820         return ret;
 821 }
 822
 823 /*
 824  * Function irlap_state_setup (event, skb, frame)
 825  *
 826  *    SETUP state, The local layer has transmitted a SNRM command frame to
 827  *    a remote peer layer and is awaiting a reply .
 828  *
 829  */
 830 static int irlap_state_setup(struct irlap_cb *self, IRLAP_EVENT event,
 831                              struct sk_buff *skb, struct irlap_info *info)
 832 {
 833         int ret = 0;
 834
 835         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 836
 837         IRDA_ASSERT(self != NULL, return -1;);
 838         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 839
 840         switch (event) {
 841         case FINAL_TIMER_EXPIRED:
 842                 if (self->retry_count < self->N3) {
 843 /*
 844  *  Perform random backoff, Wait a random number of time units, minimum
 845  *  duration half the time taken to transmitt a SNRM frame, maximum duration
 846  *  1.5 times the time taken to transmit a SNRM frame. So this time should
 847  *  between 15 msecs and 45 msecs.
 848  */
 849                         irlap_start_backoff_timer(self, msecs_to_jiffies(20 +
 850                                                         (jiffies % 30)));
 851                 } else {
 852                         /* Always switch state before calling upper layers */
 853                         irlap_next_state(self, LAP_NDM);
 854
 855                         irlap_disconnect_indication(self, LAP_FOUND_NONE);
 856                 }
 857                 break;
 858         case BACKOFF_TIMER_EXPIRED:
 859                 irlap_send_snrm_frame(self, &self->qos_rx);
 860                 irlap_start_final_timer(self, self->final_timeout);
 861                 self->retry_count++;
 862                 break;
 863         case RECV_SNRM_CMD:
 864                 IRDA_DEBUG(4, "%s(), SNRM battle!\n", __FUNCTION__);
 865
 866                 IRDA_ASSERT(skb != NULL, return 0;);
 867                 IRDA_ASSERT(info != NULL, return 0;);
 868
 869                 /*
 870                  *  The device with the largest device address wins the battle
 871                  *  (both have sent a SNRM command!)
 872                  */
 873                 if (info &&(info->daddr > self->saddr)) {
 874                         del_timer(&self->final_timer);
 875                         irlap_initiate_connection_state(self);
 876
 877                         IRDA_ASSERT(self->netdev != NULL, return -1;);
 878
 879                         skb_pull(skb, sizeof(struct snrm_frame));
 880
 881                         irlap_qos_negotiate(self, skb);
 882
 883                         /* Send UA frame and then change link settings */
 884                         irlap_apply_connection_parameters(self, FALSE);
 885                         irlap_send_ua_response_frame(self, &self->qos_rx);
 886
 887                         irlap_next_state(self, LAP_NRM_S);
 888                         irlap_connect_confirm(self, skb);
 889
 890                         /*
 891                          *  The WD-timer could be set to the duration of the
 892                          *  P-timer for this case, but it is recommended
 893                          *  to use twice the value (note 3 IrLAP p. 60).
 894                          */
 895                         irlap_start_wd_timer(self, self->wd_timeout);
 896                 } else {
 897                         /* We just ignore the other device! */
 898                         irlap_next_state(self, LAP_SETUP);
 899                 }
 900                 break;
 901         case RECV_UA_RSP:
 902                 /* Stop F-timer */
 903                 del_timer(&self->final_timer);
 904
 905                 /* Initiate connection state */
 906                 irlap_initiate_connection_state(self);
 907
 908                 /* Negotiate connection parameters */
 909                 IRDA_ASSERT(skb->len > 10, return -1;);
 910
 911                 skb_pull(skb, sizeof(struct ua_frame));
 912
 913                 IRDA_ASSERT(self->netdev != NULL, return -1;);
 914
 915                 irlap_qos_negotiate(self, skb);
 916
 917                 /* Set the new link setting *now* (before the rr frame) */
 918                 irlap_apply_connection_parameters(self, TRUE);
 919                 self->retry_count = 0;
 920
 921                 /* Wait for turnaround time to give a chance to the other
 922                  * device to be ready to receive us.
 923                  * Note : the time to switch speed is typically larger
 924                  * than the turnaround time, but as we don't have the other
 925                  * side speed switch time, that's our best guess...
 926                  * Jean II */
 927                 irlap_wait_min_turn_around(self, &self->qos_tx);
 928
 929                 /* This frame will actually be sent at the new speed */
 930                 irlap_send_rr_frame(self, CMD_FRAME);
 931
 932                 /* The timer is set to half the normal timer to quickly
 933                  * detect a failure to negociate the new connection
 934                  * parameters. IrLAP 6.11.3.2, note 3.
 935                  * Note that currently we don't process this failure
 936                  * properly, as we should do a quick disconnect.
 937                  * Jean II */
 938                 irlap_start_final_timer(self, self->final_timeout/2);
 939                 irlap_next_state(self, LAP_NRM_P);
 940
 941                 irlap_connect_confirm(self, skb);
 942                 break;
 943         case RECV_DM_RSP:     /* FALLTHROUGH */
 944         case RECV_DISC_CMD:
 945                 del_timer(&self->final_timer);
 946                 irlap_next_state(self, LAP_NDM);
 947
 948                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
 949                 break;
 950         default:
 951                 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __FUNCTION__,
 952                            event, irlap_event[event]);
 953
 954                 ret = -1;
 955                 break;
 956         }
 957         return ret;
 958 }
 959
 960 /*
 961  * Function irlap_state_offline (self, event, skb, info)
 962  *
 963  *    OFFLINE state, not used for now!
 964  *
 965  */
 966 static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
 967                                struct sk_buff *skb, struct irlap_info *info)
 968 {
 969         IRDA_DEBUG( 0, "%s(), Unknown event\n", __FUNCTION__);
 970
 971         return -1;
 972 }
 973
 974 /*
 975  * Function irlap_state_xmit_p (self, event, skb, info)
 976  *
 977  *    XMIT, Only the primary station has right to transmit, and we
 978  *    therefore do not expect to receive any transmissions from other
 979  *    stations.
 980  *
 981  */
 982 static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event,
 983                               struct sk_buff *skb, struct irlap_info *info)
 984 {
 985         int ret = 0;
 986
 987         switch (event) {
 988         case SEND_I_CMD:
 989                 /*
 990                  *  Only send frame if send-window > 0.
 991                  */
 992                 if ((self->window > 0) && (!self->remote_busy)) {
 993                         int nextfit;
 994 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 995                         struct sk_buff *skb_next;
 996
 997                         /* With DYNAMIC_WINDOW, we keep the window size
 998                          * maximum, and adapt on the packets we are sending.
 999                          * At 115k, we can send only 2 packets of 2048 bytes
1000                          * in a 500 ms turnaround. Without this option, we
1001                          * would always limit the window to 2. With this
1002                          * option, if we send smaller packets, we can send
1003                          * up to 7 of them (always depending on QoS).
1004                          * Jean II */
1005
1006                         /* Look at the next skb. This is safe, as we are
1007                          * the only consumer of the Tx queue (if we are not,
1008                          * we have other problems) - Jean II */
1009                         skb_next = skb_peek(&self->txq);
1010
1011                         /* Check if a subsequent skb exist and would fit in
1012                          * the current window (with respect to turnaround
1013                          * time).
1014                          * This allow us to properly mark the current packet
1015                          * with the pf bit, to avoid falling back on the
1016                          * second test below, and avoid waiting the
1017                          * end of the window and sending a extra RR.
1018                          * Note : (skb_next != NULL) <=> (skb_queue_len() > 0)
1019                          * Jean II */
1020                         nextfit = ((skb_next != NULL) &&
1021                                    ((skb_next->len + skb->len) <=
1022                                     self->bytes_left));
1023
1024                         /*
1025                          * The current packet may not fit ! Because of test
1026                          * above, this should not happen any more !!!
1027                          *  Test if we have transmitted more bytes over the
1028                          *  link than its possible to do with the current
1029                          *  speed and turn-around-time.
1030                          */
1031                         if((!nextfit) && (skb->len > self->bytes_left)) {
1032                                 IRDA_DEBUG(0, "%s(), Not allowed to transmit"
1033                                            " more bytes!\n", __FUNCTION__);
1034                                 /* Requeue the skb */
1035                                 skb_queue_head(&self->txq, skb_get(skb));
1036                                 /*
1037                                  *  We should switch state to LAP_NRM_P, but
1038                                  *  that is not possible since we must be sure
1039                                  *  that we poll the other side. Since we have
1040                                  *  used up our time, the poll timer should
1041                                  *  trigger anyway now, so we just wait for it
1042                                  *  DB
1043                                  */
1044                                 /*
1045                                  * Sorry, but that's not totally true. If
1046                                  * we send 2000B packets, we may wait another
1047                                  * 1000B until our turnaround expire. That's
1048                                  * why we need to be proactive in avoiding
1049                                  * coming here. - Jean II
1050                                  */
1051                                 return -EPROTO;
1052                         }
1053
1054                         /* Substract space used by this skb */
1055                         self->bytes_left -= skb->len;
1056 #else   /* CONFIG_IRDA_DYNAMIC_WINDOW */
1057                         /* Window has been adjusted for the max packet
1058                          * size, so much simpler... - Jean II */
1059                         nextfit = !skb_queue_empty(&self->txq);
1060 #endif  /* CONFIG_IRDA_DYNAMIC_WINDOW */
1061                         /*
1062                          *  Send data with poll bit cleared only if window > 1
1063                          *  and there is more frames after this one to be sent
1064                          */
1065                         if ((self->window > 1) && (nextfit)) {
1066                                 /* More packet to send in current window */
1067                                 irlap_send_data_primary(self, skb);
1068                                 irlap_next_state(self, LAP_XMIT_P);
1069                         } else {
1070                                 /* Final packet of window */
1071                                 irlap_send_data_primary_poll(self, skb);
1072
1073                                 /*
1074                                  * Make sure state machine does not try to send
1075                                  * any more frames
1076                                  */
1077                                 ret = -EPROTO;
1078                         }
1079 #ifdef CONFIG_IRDA_FAST_RR
1080                         /* Peer may want to reply immediately */
1081                         self->fast_RR = FALSE;
1082 #endif /* CONFIG_IRDA_FAST_RR */
1083                 } else {
1084                         IRDA_DEBUG(4, "%s(), Unable to send! remote busy?\n",
1085                                    __FUNCTION__);
1086                         skb_queue_head(&self->txq, skb_get(skb));
1087
1088                         /*
1089                          *  The next ret is important, because it tells
1090                          *  irlap_next_state _not_ to deliver more frames
1091                          */
1092                         ret = -EPROTO;
1093                 }
1094                 break;
1095         case POLL_TIMER_EXPIRED:
1096                 IRDA_DEBUG(3, "%s(), POLL_TIMER_EXPIRED <%ld>\n",
1097                             __FUNCTION__, jiffies);
1098                 irlap_send_rr_frame(self, CMD_FRAME);
1099                 /* Return to NRM properly - Jean II  */
1100                 self->window = self->window_size;
1101 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1102                 /* Allowed to transmit a maximum number of bytes again. */
1103                 self->bytes_left = self->line_capacity;
1104 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1105                 irlap_start_final_timer(self, self->final_timeout);
1106                 irlap_next_state(self, LAP_NRM_P);
1107                 break;
1108         case DISCONNECT_REQUEST:
1109                 del_timer(&self->poll_timer);
1110                 irlap_wait_min_turn_around(self, &self->qos_tx);
1111                 irlap_send_disc_frame(self);
1112                 irlap_flush_all_queues(self);
1113                 irlap_start_final_timer(self, self->final_timeout);
1114                 self->retry_count = 0;
1115                 irlap_next_state(self, LAP_PCLOSE);
1116                 break;
1117         case DATA_REQUEST:
1118                 /* Nothing to do, irlap_do_event() will send the packet
1119                  * when we return... - Jean II */
1120                 break;
1121         default:
1122                 IRDA_DEBUG(0, "%s(), Unknown event %s\n",
1123                            __FUNCTION__, irlap_event[event]);
1124
1125                 ret = -EINVAL;
1126                 break;
1127         }
1128         return ret;
1129 }
1130
1131 /*
1132  * Function irlap_state_pclose (event, skb, info)
1133  *
1134  *    PCLOSE state
1135  */
1136 static int irlap_state_pclose(struct irlap_cb *self, IRLAP_EVENT event,
1137                               struct sk_buff *skb, struct irlap_info *info)
1138 {
1139         int ret = 0;
1140
1141         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1142
1143         IRDA_ASSERT(self != NULL, return -1;);
1144         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1145
1146         switch (event) {
1147         case RECV_UA_RSP: /* FALLTHROUGH */
1148         case RECV_DM_RSP:
1149                 del_timer(&self->final_timer);
1150
1151                 /* Set new link parameters */
1152                 irlap_apply_default_connection_parameters(self);
1153
1154                 /* Always switch state before calling upper layers */
1155                 irlap_next_state(self, LAP_NDM);
1156
1157                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
1158                 break;
1159         case FINAL_TIMER_EXPIRED:
1160                 if (self->retry_count < self->N3) {
1161                         irlap_wait_min_turn_around(self, &self->qos_tx);
1162                         irlap_send_disc_frame(self);
1163                         irlap_start_final_timer(self, self->final_timeout);
1164                         self->retry_count++;
1165                         /* Keep state */
1166                 } else {
1167                         irlap_apply_default_connection_parameters(self);
1168
1169                         /*  Always switch state before calling upper layers */
1170                         irlap_next_state(self, LAP_NDM);
1171
1172                         irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1173                 }
1174                 break;
1175         default:
1176                 IRDA_DEBUG(1, "%s(), Unknown event %d\n", __FUNCTION__, event);
1177
1178                 ret = -1;
1179                 break;
1180         }
1181         return ret;
1182 }
1183
1184 /*
1185  * Function irlap_state_nrm_p (self, event, skb, info)
1186  *
1187  *   NRM_P (Normal Response Mode as Primary), The primary station has given
1188  *   permissions to a secondary station to transmit IrLAP resonse frames
1189  *   (by sending a frame with the P bit set). The primary station will not
1190  *   transmit any frames and is expecting to receive frames only from the
1191  *   secondary to which transmission permissions has been given.
1192  */
1193 static int irlap_state_nrm_p(struct irlap_cb *self, IRLAP_EVENT event,
1194                              struct sk_buff *skb, struct irlap_info *info)
1195 {
1196         int ret = 0;
1197         int ns_status;
1198         int nr_status;
1199
1200         switch (event) {
1201         case RECV_I_RSP: /* Optimize for the common case */
1202                 /* FIXME: must check for remote_busy below */
1203 #ifdef CONFIG_IRDA_FAST_RR
1204                 /*
1205                  *  Reset the fast_RR so we can use the fast RR code with
1206                  *  full speed the next time since peer may have more frames
1207                  *  to transmitt
1208                  */
1209                 self->fast_RR = FALSE;
1210 #endif /* CONFIG_IRDA_FAST_RR */
1211                 IRDA_ASSERT( info != NULL, return -1;);
1212
1213                 ns_status = irlap_validate_ns_received(self, info->ns);
1214                 nr_status = irlap_validate_nr_received(self, info->nr);
1215
1216                 /*
1217                  *  Check for expected I(nformation) frame
1218                  */
1219                 if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
1220
1221                         /* Update Vr (next frame for us to receive) */
1222                         self->vr = (self->vr + 1) % 8;
1223
1224                         /* Update Nr received, cleanup our retry queue */
1225                         irlap_update_nr_received(self, info->nr);
1226
1227                         /*
1228                          *  Got expected NR, so reset the
1229                          *  retry_count. This is not done by IrLAP spec,
1230                          *  which is strange!
1231                          */
1232                         self->retry_count = 0;
1233                         self->ack_required = TRUE;
1234
1235                         /*  poll bit cleared?  */
1236                         if (!info->pf) {
1237                                 /* Keep state, do not move this line */
1238                                 irlap_next_state(self, LAP_NRM_P);
1239
1240                                 irlap_data_indication(self, skb, FALSE);
1241                         } else {
1242                                 /* No longer waiting for pf */
1243                                 del_timer(&self->final_timer);
1244
1245                                 irlap_wait_min_turn_around(self, &self->qos_tx);
1246
1247                                 /* Call higher layer *before* changing state
1248                                  * to give them a chance to send data in the
1249                                  * next LAP frame.
1250                                  * Jean II */
1251                                 irlap_data_indication(self, skb, FALSE);
1252
1253                                 /* XMIT states are the most dangerous state
1254                                  * to be in, because user requests are
1255                                  * processed directly and may change state.
1256                                  * On the other hand, in NDM_P, those
1257                                  * requests are queued and we will process
1258                                  * them when we return to irlap_do_event().
1259                                  * Jean II
1260                                  */
1261                                 irlap_next_state(self, LAP_XMIT_P);
1262
1263                                 /* This is the last frame.
1264                                  * Make sure it's always called in XMIT state.
1265                                  * - Jean II */
1266                                 irlap_start_poll_timer(self, self->poll_timeout);
1267                         }
1268                         break;
1269
1270                 }
1271                 /* Unexpected next to send (Ns) */
1272                 if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
1273                 {
1274                         if (!info->pf) {
1275                                 irlap_update_nr_received(self, info->nr);
1276
1277                                 /*
1278                                  *  Wait until the last frame before doing
1279                                  *  anything
1280                                  */
1281
1282                                 /* Keep state */
1283                                 irlap_next_state(self, LAP_NRM_P);
1284                         } else {
1285                                 IRDA_DEBUG(4,
1286                                        "%s(), missing or duplicate frame!\n",
1287                                            __FUNCTION__);
1288
1289                                 /* Update Nr received */
1290                                 irlap_update_nr_received(self, info->nr);
1291
1292                                 irlap_wait_min_turn_around(self, &self->qos_tx);
1293                                 irlap_send_rr_frame(self, CMD_FRAME);
1294
1295                                 self->ack_required = FALSE;
1296
1297                                 irlap_start_final_timer(self, self->final_timeout);
1298                                 irlap_next_state(self, LAP_NRM_P);
1299                         }
1300                         break;
1301                 }
1302                 /*
1303                  *  Unexpected next to receive (Nr)
1304                  */
1305                 if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
1306                 {
1307                         if (info->pf) {
1308                                 self->vr = (self->vr + 1) % 8;
1309
1310                                 /* Update Nr received */
1311                                 irlap_update_nr_received(self, info->nr);
1312
1313                                 /* Resend rejected frames */
1314                                 irlap_resend_rejected_frames(self, CMD_FRAME);
1315
1316                                 self->ack_required = FALSE;
1317
1318                                 /* Make sure we account for the time
1319                                  * to transmit our frames. See comemnts
1320                                  * in irlap_send_data_primary_poll().
1321                                  * Jean II */
1322                                 irlap_start_final_timer(self, 2 * self->final_timeout);
1323
1324                                 /* Keep state, do not move this line */
1325                                 irlap_next_state(self, LAP_NRM_P);
1326
1327                                 irlap_data_indication(self, skb, FALSE);
1328                         } else {
1329                                 /*
1330                                  *  Do not resend frames until the last
1331                                  *  frame has arrived from the other
1332                                  *  device. This is not documented in
1333                                  *  IrLAP!!
1334                                  */
1335                                 self->vr = (self->vr + 1) % 8;
1336
1337                                 /* Update Nr received */
1338                                 irlap_update_nr_received(self, info->nr);
1339
1340                                 self->ack_required = FALSE;
1341
1342                                 /* Keep state, do not move this line!*/
1343                                 irlap_next_state(self, LAP_NRM_P);
1344
1345                                 irlap_data_indication(self, skb, FALSE);
1346                         }
1347                         break;
1348                 }
1349                 /*
1350                  *  Unexpected next to send (Ns) and next to receive (Nr)
1351                  *  Not documented by IrLAP!
1352                  */
1353                 if ((ns_status == NS_UNEXPECTED) &&
1354                     (nr_status == NR_UNEXPECTED))
1355                 {
1356                         IRDA_DEBUG(4, "%s(), unexpected nr and ns!\n",
1357                                    __FUNCTION__);
1358                         if (info->pf) {
1359                                 /* Resend rejected frames */
1360                                 irlap_resend_rejected_frames(self, CMD_FRAME);
1361
1362                                 /* Give peer some time to retransmit!
1363                                  * But account for our own Tx. */
1364                                 irlap_start_final_timer(self, 2 * self->final_timeout);
1365
1366                                 /* Keep state, do not move this line */
1367                                 irlap_next_state(self, LAP_NRM_P);
1368                         } else {
1369                                 /* Update Nr received */
1370                                 /* irlap_update_nr_received( info->nr); */
1371
1372                                 self->ack_required = FALSE;
1373                         }
1374                         break;
1375                 }
1376
1377                 /*
1378                  *  Invalid NR or NS
1379                  */
1380                 if ((nr_status == NR_INVALID) || (ns_status == NS_INVALID)) {
1381                         if (info->pf) {
1382                                 del_timer(&self->final_timer);
1383
1384                                 irlap_next_state(self, LAP_RESET_WAIT);
1385
1386                                 irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1387                                 self->xmitflag = TRUE;
1388                         } else {
1389                                 del_timer(&self->final_timer);
1390
1391                                 irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1392
1393                                 self->xmitflag = FALSE;
1394                         }
1395                         break;
1396                 }
1397                 IRDA_DEBUG(1, "%s(), Not implemented!\n", __FUNCTION__);
1398                 IRDA_DEBUG(1, "%s(), event=%s, ns_status=%d, nr_status=%d\n",
1399                        __FUNCTION__, irlap_event[event], ns_status, nr_status);
1400                 break;
1401         case RECV_UI_FRAME:
1402                 /* Poll bit cleared? */
1403                 if (!info->pf) {
1404                         irlap_data_indication(self, skb, TRUE);
1405                         irlap_next_state(self, LAP_NRM_P);
1406                 } else {
1407                         del_timer(&self->final_timer);
1408                         irlap_data_indication(self, skb, TRUE);
1409                         irlap_next_state(self, LAP_XMIT_P);
1410                         IRDA_DEBUG(1, "%s: RECV_UI_FRAME: next state %s\n", __FUNCTION__, irlap_state[self->state]);
1411                         irlap_start_poll_timer(self, self->poll_timeout);
1412                 }
1413                 break;
1414         case RECV_RR_RSP:
1415                 /*
1416                  *  If you get a RR, the remote isn't busy anymore,
1417                  *  no matter what the NR
1418                  */
1419                 self->remote_busy = FALSE;
1420
1421                 /* Stop final timer */
1422                 del_timer(&self->final_timer);
1423
1424                 /*
1425                  *  Nr as expected?
1426                  */
1427                 ret = irlap_validate_nr_received(self, info->nr);
1428                 if (ret == NR_EXPECTED) {
1429                         /* Update Nr received */
1430                         irlap_update_nr_received(self, info->nr);
1431
1432                         /*
1433                          *  Got expected NR, so reset the retry_count. This
1434                          *  is not done by the IrLAP standard , which is
1435                          *  strange! DB.
1436                          */
1437                         self->retry_count = 0;
1438                         irlap_wait_min_turn_around(self, &self->qos_tx);
1439
1440                         irlap_next_state(self, LAP_XMIT_P);
1441
1442                         /* Start poll timer */
1443                         irlap_start_poll_timer(self, self->poll_timeout);
1444                 } else if (ret == NR_UNEXPECTED) {
1445                         IRDA_ASSERT(info != NULL, return -1;);
1446                         /*
1447                          *  Unexpected nr!
1448                          */
1449
1450                         /* Update Nr received */
1451                         irlap_update_nr_received(self, info->nr);
1452
1453                         IRDA_DEBUG(4, "RECV_RR_FRAME: Retrans:%d, nr=%d, va=%d, "
1454                               "vs=%d, vr=%d\n",
1455                               self->retry_count, info->nr, self->va,
1456                               self->vs, self->vr);
1457
1458                         /* Resend rejected frames */
1459                         irlap_resend_rejected_frames(self, CMD_FRAME);
1460                         irlap_start_final_timer(self, self->final_timeout * 2);
1461
1462                         irlap_next_state(self, LAP_NRM_P);
1463                 } else if (ret == NR_INVALID) {
1464                         IRDA_DEBUG(1, "%s(), Received RR with "
1465                                    "invalid nr !\n", __FUNCTION__);
1466
1467                         irlap_next_state(self, LAP_RESET_WAIT);
1468
1469                         irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1470                         self->xmitflag = TRUE;
1471                 }
1472                 break;
1473         case RECV_RNR_RSP:
1474                 IRDA_ASSERT(info != NULL, return -1;);
1475
1476                 /* Stop final timer */
1477                 del_timer(&self->final_timer);
1478                 self->remote_busy = TRUE;
1479
1480                 /* Update Nr received */
1481                 irlap_update_nr_received(self, info->nr);
1482                 irlap_next_state(self, LAP_XMIT_P);
1483
1484                 /* Start poll timer */
1485                 irlap_start_poll_timer(self, self->poll_timeout);
1486                 break;
1487         case RECV_FRMR_RSP:
1488                 del_timer(&self->final_timer);
1489                 self->xmitflag = TRUE;
1490                 irlap_next_state(self, LAP_RESET_WAIT);
1491                 irlap_reset_indication(self);
1492                 break;
1493         case FINAL_TIMER_EXPIRED:
1494                 /*
1495                  *  We are allowed to wait for additional 300 ms if
1496                  *  final timer expires when we are in the middle
1497                  *  of receiving a frame (page 45, IrLAP). Check that
1498                  *  we only do this once for each frame.
1499                  */
1500                 if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
1501                         IRDA_DEBUG(1, "FINAL_TIMER_EXPIRED when receiving a "
1502                               "frame! Waiting a little bit more!\n");
1503                         irlap_start_final_timer(self, msecs_to_jiffies(300));
1504
1505                         /*
1506                          *  Don't allow this to happen one more time in a row,
1507                          *  or else we can get a pretty tight loop here if
1508                          *  if we only receive half a frame. DB.
1509                          */
1510                         self->add_wait = TRUE;
1511                         break;
1512                 }
1513                 self->add_wait = FALSE;
1514
1515                 /* N2 is the disconnect timer. Until we reach it, we retry */
1516                 if (self->retry_count < self->N2) {
1517                         /* Retry sending the pf bit to the secondary */
1518                         irlap_wait_min_turn_around(self, &self->qos_tx);
1519                         irlap_send_rr_frame(self, CMD_FRAME);
1520
1521                         irlap_start_final_timer(self, self->final_timeout);
1522                         self->retry_count++;
1523                         IRDA_DEBUG(4, "irlap_state_nrm_p: FINAL_TIMER_EXPIRED:"
1524                                    " retry_count=%d\n", self->retry_count);
1525
1526                         /* Early warning event. I'm using a pretty liberal
1527                          * interpretation of the spec and generate an event
1528                          * every time the timer is multiple of N1 (and not
1529                          * only the first time). This allow application
1530                          * to know precisely if connectivity restart...
1531                          * Jean II */
1532                         if((self->retry_count % self->N1) == 0)
1533                                 irlap_status_indication(self,
1534                                                         STATUS_NO_ACTIVITY);
1535
1536                         /* Keep state */
1537                 } else {
1538                         irlap_apply_default_connection_parameters(self);
1539
1540                         /* Always switch state before calling upper layers */
1541                         irlap_next_state(self, LAP_NDM);
1542                         irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1543                 }
1544                 break;
1545         case RECV_REJ_RSP:
1546                 irlap_update_nr_received(self, info->nr);
1547                 if (self->remote_busy) {
1548                         irlap_wait_min_turn_around(self, &self->qos_tx);
1549                         irlap_send_rr_frame(self, CMD_FRAME);
1550                 } else
1551                         irlap_resend_rejected_frames(self, CMD_FRAME);
1552                 irlap_start_final_timer(self, 2 * self->final_timeout);
1553                 break;
1554         case RECV_SREJ_RSP:
1555                 irlap_update_nr_received(self, info->nr);
1556                 if (self->remote_busy) {
1557                         irlap_wait_min_turn_around(self, &self->qos_tx);
1558                         irlap_send_rr_frame(self, CMD_FRAME);
1559                 } else
1560                         irlap_resend_rejected_frame(self, CMD_FRAME);
1561                 irlap_start_final_timer(self, 2 * self->final_timeout);
1562                 break;
1563         case RECV_RD_RSP:
1564                 IRDA_DEBUG(1, "%s(), RECV_RD_RSP\n", __FUNCTION__);
1565
1566                 irlap_flush_all_queues(self);
1567                 irlap_next_state(self, LAP_XMIT_P);
1568                 /* Call back the LAP state machine to do a proper disconnect */
1569                 irlap_disconnect_request(self);
1570                 break;
1571         default:
1572                 IRDA_DEBUG(1, "%s(), Unknown event %s\n",
1573                             __FUNCTION__, irlap_event[event]);
1574
1575                 ret = -1;
1576                 break;
1577         }
1578         return ret;
1579 }
1580
1581 /*
1582  * Function irlap_state_reset_wait (event, skb, info)
1583  *
1584  *    We have informed the service user of a reset condition, and is
1585  *    awaiting reset of disconnect request.
1586  *
1587  */
1588 static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
1589                                   struct sk_buff *skb, struct irlap_info *info)
1590 {
1591         int ret = 0;
1592
1593         IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]);
1594
1595         IRDA_ASSERT(self != NULL, return -1;);
1596         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1597
1598         switch (event) {
1599         case RESET_REQUEST:
1600                 if (self->xmitflag) {
1601                         irlap_wait_min_turn_around(self, &self->qos_tx);
1602                         irlap_send_snrm_frame(self, NULL);
1603                         irlap_start_final_timer(self, self->final_timeout);
1604                         irlap_next_state(self, LAP_RESET);
1605                 } else {
1606                         irlap_start_final_timer(self, self->final_timeout);
1607                         irlap_next_state(self, LAP_RESET);
1608                 }
1609                 break;
1610         case DISCONNECT_REQUEST:
1611                 irlap_wait_min_turn_around( self, &self->qos_tx);
1612                 irlap_send_disc_frame( self);
1613                 irlap_flush_all_queues( self);
1614                 irlap_start_final_timer( self, self->final_timeout);
1615                 self->retry_count = 0;
1616                 irlap_next_state( self, LAP_PCLOSE);
1617                 break;
1618         default:
1619                 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
1620                            irlap_event[event]);
1621
1622                 ret = -1;
1623                 break;
1624         }
1625         return ret;
1626 }
1627
1628 /*
1629  * Function irlap_state_reset (self, event, skb, info)
1630  *
1631  *    We have sent a SNRM reset command to the peer layer, and is awaiting
1632  *    reply.
1633  *
1634  */
1635 static int irlap_state_reset(struct irlap_cb *self, IRLAP_EVENT event,
1636                              struct sk_buff *skb, struct irlap_info *info)
1637 {
1638         int ret = 0;
1639
1640         IRDA_DEBUG(3, "%s(), event = %s\n", __FUNCTION__, irlap_event[event]);
1641
1642         IRDA_ASSERT(self != NULL, return -1;);
1643         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1644
1645         switch (event) {
1646         case RECV_DISC_CMD:
1647                 del_timer(&self->final_timer);
1648
1649                 irlap_apply_default_connection_parameters(self);
1650
1651                 /* Always switch state before calling upper layers */
1652                 irlap_next_state(self, LAP_NDM);
1653
1654                 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1655
1656                 break;
1657         case RECV_UA_RSP:
1658                 del_timer(&self->final_timer);
1659
1660                 /* Initiate connection state */
1661                 irlap_initiate_connection_state(self);
1662
1663                 irlap_reset_confirm();
1664
1665                 self->remote_busy = FALSE;
1666
1667                 irlap_next_state(self, LAP_XMIT_P);
1668
1669                 irlap_start_poll_timer(self, self->poll_timeout);
1670
1671                 break;
1672         case FINAL_TIMER_EXPIRED:
1673                 if (self->retry_count < 3) {
1674                         irlap_wait_min_turn_around(self, &self->qos_tx);
1675
1676                         IRDA_ASSERT(self->netdev != NULL, return -1;);
1677                         irlap_send_snrm_frame(self, self->qos_dev);
1678
1679                         self->retry_count++; /* Experimental!! */
1680
1681                         irlap_start_final_timer(self, self->final_timeout);
1682                         irlap_next_state(self, LAP_RESET);
1683                 } else if (self->retry_count >= self->N3) {
1684                         irlap_apply_default_connection_parameters(self);
1685
1686                         /* Always switch state before calling upper layers */
1687                         irlap_next_state(self, LAP_NDM);
1688
1689                         irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1690                 }
1691                 break;
1692         case RECV_SNRM_CMD:
1693                 /*
1694                  * SNRM frame is not allowed to contain an I-field in this
1695                  * state
1696                  */
1697                 if (!info) {
1698                         IRDA_DEBUG(3, "%s(), RECV_SNRM_CMD\n", __FUNCTION__);
1699                         irlap_initiate_connection_state(self);
1700                         irlap_wait_min_turn_around(self, &self->qos_tx);
1701                         irlap_send_ua_response_frame(self, &self->qos_rx);
1702                         irlap_reset_confirm();
1703                         irlap_start_wd_timer(self, self->wd_timeout);
1704                         irlap_next_state(self, LAP_NDM);
1705                 } else {
1706                         IRDA_DEBUG(0,
1707                                    "%s(), SNRM frame contained an I field!\n",
1708                                    __FUNCTION__);
1709                 }
1710                 break;
1711         default:
1712                 IRDA_DEBUG(1, "%s(), Unknown event %s\n",
1713                            __FUNCTION__, irlap_event[event]);
1714
1715                 ret = -1;
1716                 break;
1717         }
1718         return ret;
1719 }
1720
1721 /*
1722  * Function irlap_state_xmit_s (event, skb, info)
1723  *
1724  *   XMIT_S, The secondary station has been given the right to transmit,
1725  *   and we therefor do not expect to receive any transmissions from other
1726  *   stations.
1727  */
1728 static int irlap_state_xmit_s(struct irlap_cb *self, IRLAP_EVENT event,
1729                               struct sk_buff *skb, struct irlap_info *info)
1730 {
1731         int ret = 0;
1732
1733         IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]);
1734
1735         IRDA_ASSERT(self != NULL, return -ENODEV;);
1736         IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
1737
1738         switch (event) {
1739         case SEND_I_CMD:
1740                 /*
1741                  *  Send frame only if send window > 0
1742                  */
1743                 if ((self->window > 0) && (!self->remote_busy)) {
1744                         int nextfit;
1745 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1746                         struct sk_buff *skb_next;
1747
1748                         /*
1749                          * Same deal as in irlap_state_xmit_p(), so see
1750                          * the comments at that point.
1751                          * We are the secondary, so there are only subtle
1752                          * differences. - Jean II
1753                          */
1754
1755                         /* Check if a subsequent skb exist and would fit in
1756                          * the current window (with respect to turnaround
1757                          * time). - Jean II */
1758                         skb_next = skb_peek(&self->txq);
1759                         nextfit = ((skb_next != NULL) &&
1760                                    ((skb_next->len + skb->len) <=
1761                                     self->bytes_left));
1762
1763                         /*
1764                          *  Test if we have transmitted more bytes over the
1765                          *  link than its possible to do with the current
1766                          *  speed and turn-around-time.
1767                          */
1768                         if((!nextfit) && (skb->len > self->bytes_left)) {
1769                                 IRDA_DEBUG(0, "%s(), Not allowed to transmit"
1770                                            " more bytes!\n", __FUNCTION__);
1771                                 /* Requeue the skb */
1772                                 skb_queue_head(&self->txq, skb_get(skb));
1773
1774                                 /*
1775                                  *  Switch to NRM_S, this is only possible
1776                                  *  when we are in secondary mode, since we
1777                                  *  must be sure that we don't miss any RR
1778                                  *  frames
1779                                  */
1780                                 self->window = self->window_size;
1781                                 self->bytes_left = self->line_capacity;
1782                                 irlap_start_wd_timer(self, self->wd_timeout);
1783
1784                                 irlap_next_state(self, LAP_NRM_S);
1785                                 /* Slight difference with primary :
1786                                  * here we would wait for the other side to
1787                                  * expire the turnaround. - Jean II */
1788
1789                                 return -EPROTO; /* Try again later */
1790                         }
1791                         /* Substract space used by this skb */
1792                         self->bytes_left -= skb->len;
1793 #else   /* CONFIG_IRDA_DYNAMIC_WINDOW */
1794                         /* Window has been adjusted for the max packet
1795                          * size, so much simpler... - Jean II */
1796                         nextfit = !skb_queue_empty(&self->txq);
1797 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1798                         /*
1799                          *  Send data with final bit cleared only if window > 1
1800                          *  and there is more frames to be sent
1801                          */
1802                         if ((self->window > 1) && (nextfit)) {
1803                                 irlap_send_data_secondary(self, skb);
1804                                 irlap_next_state(self, LAP_XMIT_S);
1805                         } else {
1806                                 irlap_send_data_secondary_final(self, skb);
1807                                 irlap_next_state(self, LAP_NRM_S);
1808
1809                                 /*
1810                                  * Make sure state machine does not try to send
1811                                  * any more frames
1812                                  */
1813                                 ret = -EPROTO;
1814                         }
1815                 } else {
1816                         IRDA_DEBUG(2, "%s(), Unable to send!\n", __FUNCTION__);
1817                         skb_queue_head(&self->txq, skb_get(skb));
1818                         ret = -EPROTO;
1819                 }
1820                 break;
1821         case DISCONNECT_REQUEST:
1822                 irlap_send_rd_frame(self);
1823                 irlap_flush_all_queues(self);
1824                 irlap_start_wd_timer(self, self->wd_timeout);
1825                 irlap_next_state(self, LAP_SCLOSE);
1826                 break;
1827         case DATA_REQUEST:
1828                 /* Nothing to do, irlap_do_event() will send the packet
1829                  * when we return... - Jean II */
1830                 break;
1831         default:
1832                 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __FUNCTION__,
1833                            irlap_event[event]);
1834
1835                 ret = -EINVAL;
1836                 break;
1837         }
1838         return ret;
1839 }
1840
1841 /*
1842  * Function irlap_state_nrm_s (event, skb, info)
1843  *
1844  *    NRM_S (Normal Response Mode as Secondary) state, in this state we are
1845  *    expecting to receive frames from the primary station
1846  *
1847  */
1848 static int irlap_state_nrm_s(struct irlap_cb *self, IRLAP_EVENT event,
1849                              struct sk_buff *skb, struct irlap_info *info)
1850 {
1851         int ns_status;
1852         int nr_status;
1853         int ret = 0;
1854
1855         IRDA_DEBUG(4, "%s(), event=%s\n", __FUNCTION__, irlap_event[ event]);
1856
1857         IRDA_ASSERT(self != NULL, return -1;);
1858         IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1859
1860         switch (event) {
1861         case RECV_I_CMD: /* Optimize for the common case */
1862                 /* FIXME: must check for remote_busy below */
1863                 IRDA_DEBUG(4, "%s(), event=%s nr=%d, vs=%d, ns=%d, "
1864                            "vr=%d, pf=%d\n", __FUNCTION__,
1865                            irlap_event[event], info->nr,
1866                            self->vs, info->ns, self->vr, info->pf);
1867
1868                 self->retry_count = 0;
1869
1870                 ns_status = irlap_validate_ns_received(self, info->ns);
1871                 nr_status = irlap_validate_nr_received(self, info->nr);
1872                 /*
1873                  *  Check for expected I(nformation) frame
1874                  */
1875                 if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
1876
1877                         /* Update Vr (next frame for us to receive) */
1878                         self->vr = (self->vr + 1) % 8;
1879
1880                         /* Update Nr received */
1881                         irlap_update_nr_received(self, info->nr);
1882
1883                         /*
1884                          *  poll bit cleared?
1885                          */
1886                         if (!info->pf) {
1887
1888                                 self->ack_required = TRUE;
1889
1890                                 /*
1891                                  *  Starting WD-timer here is optional, but
1892                                  *  not recommended. Note 6 IrLAP p. 83
1893                                  */
1894 #if 0
1895                                 irda_start_timer(WD_TIMER, self->wd_timeout);
1896 #endif
1897                                 /* Keep state, do not move this line */
1898                                 irlap_next_state(self, LAP_NRM_S);
1899
1900                                 irlap_data_indication(self, skb, FALSE);
1901                                 break;
1902                         } else {
1903                                 /*
1904                                  *  We should wait before sending RR, and
1905                                  *  also before changing to XMIT_S
1906                                  *  state. (note 1, IrLAP p. 82)
1907                                  */
1908                                 irlap_wait_min_turn_around(self, &self->qos_tx);
1909
1910                                 /*
1911                                  * Give higher layers a chance to
1912                                  * immediately reply with some data before
1913                                  * we decide if we should send a RR frame
1914                                  * or not
1915                                  */
1916                                 irlap_data_indication(self, skb, FALSE);
1917
1918                                 /* Any pending data requests?  */
1919                                 if (!skb_queue_empty(&self->txq) &&
1920                                     (self->window > 0))
1921                                 {
1922                                         self->ack_required = TRUE;
1923
1924                                         del_timer(&self->wd_timer);
1925
1926                                         irlap_next_state(self, LAP_XMIT_S);
1927                                 } else {
1928                                         irlap_send_rr_frame(self, RSP_FRAME);
1929                                         irlap_start_wd_timer(self,
1930                                                              self->wd_timeout);
1931
1932                                         /* Keep the state */
1933                                         irlap_next_state(self, LAP_NRM_S);
1934                                 }
1935                                 break;
1936                         }
1937                 }
1938                 /*
1939                  *  Check for Unexpected next to send (Ns)
1940                  */
1941                 if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
1942                 {
1943                         /* Unexpected next to send, with final bit cleared */
1944                         if (!info->pf) {
1945                                 irlap_update_nr_received(self, info->nr);
1946
1947                                 irlap_start_wd_timer(self, self->wd_timeout);
1948                         } else {
1949                                 /* Update Nr received */
1950                                 irlap_update_nr_received(self, info->nr);
1951
1952                                 irlap_wait_min_turn_around(self, &self->qos_tx);
1953                                 irlap_send_rr_frame(self, RSP_FRAME);
1954
1955                                 irlap_start_wd_timer(self, self->wd_timeout);
1956                         }
1957                         break;
1958                 }
1959
1960                 /*
1961                  *  Unexpected Next to Receive(NR) ?
1962                  */
1963                 if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
1964                 {
1965                         if (info->pf) {
1966                                 IRDA_DEBUG(4, "RECV_I_RSP: frame(s) lost\n");
1967
1968                                 self->vr = (self->vr + 1) % 8;
1969
1970                                 /* Update Nr received */
1971                                 irlap_update_nr_received(self, info->nr);
1972
1973                                 /* Resend rejected frames */
1974                                 irlap_resend_rejected_frames(self, RSP_FRAME);
1975
1976                                 /* Keep state, do not move this line */
1977                                 irlap_next_state(self, LAP_NRM_S);
1978
1979                                 irlap_data_indication(self, skb, FALSE);
1980                                 irlap_start_wd_timer(self, self->wd_timeout);
1981                                 break;
1982                         }
1983                         /*
1984                          *  This is not documented in IrLAP!! Unexpected NR
1985                          *  with poll bit cleared
1986                          */
1987                         if (!info->pf) {
1988                                 self->vr = (self->vr + 1) % 8;
1989
1990                                 /* Update Nr received */
1991                                 irlap_update_nr_received(self, info->nr);
1992
1993                                 /* Keep state, do not move this line */
1994                                 irlap_next_state(self, LAP_NRM_S);
1995
1996                                 irlap_data_indication(self, skb, FALSE);
1997                                 irlap_start_wd_timer(self, self->wd_timeout);
1998                         }
1999                         break;
2000                 }
2001
2002                 if (ret == NR_INVALID) {
2003                         IRDA_DEBUG(0, "NRM_S, NR_INVALID not implemented!\n");
2004                 }
2005                 if (ret == NS_INVALID) {
2006                         IRDA_DEBUG(0, "NRM_S, NS_INVALID not implemented!\n");
2007                 }
2008                 break;
2009         case RECV_UI_FRAME:
2010                 /*
2011                  *  poll bit cleared?
2012                  */
2013                 if (!info->pf) {
2014                         irlap_data_indication(self, skb, TRUE);
2015                         irlap_next_state(self, LAP_NRM_S); /* Keep state */
2016                 } else {
2017                         /*
2018                          *  Any pending data requests?
2019                          */
2020                         if (!skb_queue_empty(&self->txq) &&
2021                             (self->window > 0) && !self->remote_busy)
2022                         {
2023                                 irlap_data_indication(self, skb, TRUE);
2024
2025                                 del_timer(&self->wd_timer);
2026
2027                                 irlap_next_state(self, LAP_XMIT_S);
2028                         } else {
2029                                 irlap_data_indication(self, skb, TRUE);
2030
2031                                 irlap_wait_min_turn_around(self, &self->qos_tx);
2032
2033                                 irlap_send_rr_frame(self, RSP_FRAME);
2034                                 self->ack_required = FALSE;
2035
2036                                 irlap_start_wd_timer(self, self->wd_timeout);
2037
2038                                 /* Keep the state */
2039                                 irlap_next_state(self, LAP_NRM_S);
2040                         }
2041                 }
2042                 break;
2043         case RECV_RR_CMD:
2044                 self->retry_count = 0;
2045
2046                 /*
2047                  *  Nr as expected?
2048                  */
2049                 nr_status = irlap_validate_nr_received(self, info->nr);
2050                 if (nr_status == NR_EXPECTED) {
2051                         if (!skb_queue_empty(&self->txq) &&
2052                             (self->window > 0)) {
2053                                 self->remote_busy = FALSE;
2054
2055                                 /* Update Nr received */
2056                                 irlap_update_nr_received(self, info->nr);
2057                                 del_timer(&self->wd_timer);
2058
2059                                 irlap_wait_min_turn_around(self, &self->qos_tx);
2060                                 irlap_next_state(self, LAP_XMIT_S);
2061                         } else {
2062                                 self->remote_busy = FALSE;
2063                                 /* Update Nr received */
2064                                 irlap_update_nr_received(self, info->nr);
2065                                 irlap_wait_min_turn_around(self, &self->qos_tx);
2066                                 irlap_start_wd_timer(self, self->wd_timeout);
2067
2068                                 /* Note : if the link is idle (this case),
2069                                  * we never go in XMIT_S, so we never get a
2070                                  * chance to process any DISCONNECT_REQUEST.
2071                                  * Do it now ! - Jean II */
2072                                 if (self->disconnect_pending) {
2073                                         /* Disconnect */
2074                                         irlap_send_rd_frame(self);
2075                                         irlap_flush_all_queues(self);
2076
2077                                         irlap_next_state(self, LAP_SCLOSE);
2078                                 } else {
2079                                         /* Just send back pf bit */
2080                                         irlap_send_rr_frame(self, RSP_FRAME);
2081
2082                                         irlap_next_state(self, LAP_NRM_S);
2083                                 }
2084                         }
2085                 } else if (nr_status == NR_UNEXPECTED) {
2086                         self->remote_busy = FALSE;
2087                         irlap_update_nr_received(self, info->nr);
2088                         irlap_resend_rejected_frames(self, RSP_FRAME);
2089
2090                         irlap_start_wd_timer(self, self->wd_timeout);
2091
2092                         /* Keep state */
2093                         irlap_next_state(self, LAP_NRM_S);
2094                 } else {
2095                         IRDA_DEBUG(1, "%s(), invalid nr not implemented!\n",
2096                                    __FUNCTION__);
2097                 }
2098                 break;
2099         case RECV_SNRM_CMD:
2100                 /* SNRM frame is not allowed to contain an I-field */
2101                 if (!info) {
2102                         del_timer(&self->wd_timer);
2103                         IRDA_DEBUG(1, "%s(), received SNRM cmd\n", __FUNCTION__);
2104                         irlap_next_state(self, LAP_RESET_CHECK);
2105
2106                         irlap_reset_indication(self);
2107                 } else {
2108                         IRDA_DEBUG(0,
2109                                    "%s(), SNRM frame contained an I-field!\n",
2110                                    __FUNCTION__);
2111
2112                 }
2113                 break;
2114         case RECV_REJ_CMD:
2115                 irlap_update_nr_received(self, info->nr);
2116                 if (self->remote_busy) {
2117                         irlap_wait_min_turn_around(self, &self->qos_tx);
2118                         irlap_send_rr_frame(self, RSP_FRAME);
2119                 } else
2120                         irlap_resend_rejected_frames(self, RSP_FRAME);
2121                 irlap_start_wd_timer(self, self->wd_timeout);
2122                 break;
2123         case RECV_SREJ_CMD:
2124                 irlap_update_nr_received(self, info->nr);
2125                 if (self->remote_busy) {
2126                         irlap_wait_min_turn_around(self, &self->qos_tx);
2127                         irlap_send_rr_frame(self, RSP_FRAME);
2128                 } else
2129                         irlap_resend_rejected_frame(self, RSP_FRAME);
2130                 irlap_start_wd_timer(self, self->wd_timeout);
2131                 break;
2132         case WD_TIMER_EXPIRED:
2133                 /*
2134                  *  Wait until retry_count * n matches negotiated threshold/
2135                  *  disconnect time (note 2 in IrLAP p. 82)
2136                  *
2137                  * Similar to irlap_state_nrm_p() -> FINAL_TIMER_EXPIRED
2138                  * Note : self->wd_timeout = (self->final_timeout * 2),
2139                  *   which explain why we use (self->N2 / 2) here !!!
2140                  * Jean II
2141                  */
2142                 IRDA_DEBUG(1, "%s(), retry_count = %d\n", __FUNCTION__,
2143                            self->retry_count);
2144
2145                 if (self->retry_count < (self->N2 / 2)) {
2146                         /* No retry, just wait for primary */
2147                         irlap_start_wd_timer(self, self->wd_timeout);
2148                         self->retry_count++;
2149
2150                         if((self->retry_count % (self->N1 / 2)) == 0)
2151                                 irlap_status_indication(self,
2152                                                         STATUS_NO_ACTIVITY);
2153                 } else {
2154                         irlap_apply_default_connection_parameters(self);
2155
2156                         /* Always switch state before calling upper layers */
2157                         irlap_next_state(self, LAP_NDM);
2158                         irlap_disconnect_indication(self, LAP_NO_RESPONSE);
2159                 }
2160                 break;
2161         case RECV_DISC_CMD:
2162                 /* Always switch state before calling upper layers */
2163                 irlap_next_state(self, LAP_NDM);
2164
2165                 /* Send disconnect response */
2166                 irlap_wait_min_turn_around(self, &self->qos_tx);
2167                 irlap_send_ua_response_frame(self, NULL);
2168
2169                 del_timer(&self->wd_timer);
2170                 irlap_flush_all_queues(self);
2171                 /* Set default link parameters */
2172                 irlap_apply_default_connection_parameters(self);
2173
2174                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2175                 break;
2176         case RECV_DISCOVERY_XID_CMD:
2177                 irlap_wait_min_turn_around(self, &self->qos_tx);
2178                 irlap_send_rr_frame(self, RSP_FRAME);
2179                 self->ack_required = TRUE;
2180                 irlap_start_wd_timer(self, self->wd_timeout);
2181                 irlap_next_state(self, LAP_NRM_S);
2182
2183                 break;
2184         case RECV_TEST_CMD:
2185                 /* Remove test frame header (only LAP header in NRM) */
2186                 skb_pull(skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
2187
2188                 irlap_wait_min_turn_around(self, &self->qos_tx);
2189                 irlap_start_wd_timer(self, self->wd_timeout);
2190
2191                 /* Send response (info will be copied) */
2192                 irlap_send_test_frame(self, self->caddr, info->daddr, skb);
2193                 break;
2194         default:
2195                 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
2196                            event, irlap_event[event]);
2197
2198                 ret = -EINVAL;
2199                 break;
2200         }
2201         return ret;
2202 }
2203
2204 /*
2205  * Function irlap_state_sclose (self, event, skb, info)
2206  */
2207 static int irlap_state_sclose(struct irlap_cb *self, IRLAP_EVENT event,
2208                               struct sk_buff *skb, struct irlap_info *info)
2209 {
2210         int ret = 0;
2211
2212         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
2213
2214         IRDA_ASSERT(self != NULL, return -ENODEV;);
2215         IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
2216
2217         switch (event) {
2218         case RECV_DISC_CMD:
2219                 /* Always switch state before calling upper layers */
2220                 irlap_next_state(self, LAP_NDM);
2221
2222                 /* Send disconnect response */
2223                 irlap_wait_min_turn_around(self, &self->qos_tx);
2224                 irlap_send_ua_response_frame(self, NULL);
2225
2226                 del_timer(&self->wd_timer);
2227                 /* Set default link parameters */
2228                 irlap_apply_default_connection_parameters(self);
2229
2230                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2231                 break;
2232         case RECV_DM_RSP:
2233                 /* IrLAP-1.1 p.82: in SCLOSE, S and I type RSP frames
2234                  * shall take us down into default NDM state, like DM_RSP
2235                  */
2236         case RECV_RR_RSP:
2237         case RECV_RNR_RSP:
2238         case RECV_REJ_RSP:
2239         case RECV_SREJ_RSP:
2240         case RECV_I_RSP:
2241                 /* Always switch state before calling upper layers */
2242                 irlap_next_state(self, LAP_NDM);
2243
2244                 del_timer(&self->wd_timer);
2245                 irlap_apply_default_connection_parameters(self);
2246
2247                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2248                 break;
2249         case WD_TIMER_EXPIRED:
2250                 /* Always switch state before calling upper layers */
2251                 irlap_next_state(self, LAP_NDM);
2252
2253                 irlap_apply_default_connection_parameters(self);
2254
2255                 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2256                 break;
2257         default:
2258                 /* IrLAP-1.1 p.82: in SCLOSE, basically any received frame
2259                  * with pf=1 shall restart the wd-timer and resend the rd:rsp
2260                  */
2261                 if (info != NULL  &&  info->pf) {
2262                         del_timer(&self->wd_timer);
2263                         irlap_wait_min_turn_around(self, &self->qos_tx);
2264                         irlap_send_rd_frame(self);
2265                         irlap_start_wd_timer(self, self->wd_timeout);
2266                         break;          /* stay in SCLOSE */
2267                 }
2268
2269                 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
2270                            event, irlap_event[event]);
2271
2272                 ret = -EINVAL;
2273                 break;
2274         }
2275
2276         return -1;
2277 }
2278
2279 static int irlap_state_reset_check( struct irlap_cb *self, IRLAP_EVENT event,
2280                                    struct sk_buff *skb,
2281                                    struct irlap_info *info)
2282 {
2283         int ret = 0;
2284
2285         IRDA_DEBUG(1, "%s(), event=%s\n", __FUNCTION__, irlap_event[event]);
2286
2287         IRDA_ASSERT(self != NULL, return -ENODEV;);
2288         IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
2289
2290         switch (event) {
2291         case RESET_RESPONSE:
2292                 irlap_send_ua_response_frame(self, &self->qos_rx);
2293                 irlap_initiate_connection_state(self);
2294                 irlap_start_wd_timer(self, WD_TIMEOUT);
2295                 irlap_flush_all_queues(self);
2296
2297                 irlap_next_state(self, LAP_NRM_S);
2298                 break;
2299         case DISCONNECT_REQUEST:
2300                 irlap_wait_min_turn_around(self, &self->qos_tx);
2301                 irlap_send_rd_frame(self);
2302                 irlap_start_wd_timer(self, WD_TIMEOUT);
2303                 irlap_next_state(self, LAP_SCLOSE);
2304                 break;
2305         default:
2306                 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __FUNCTION__,
2307                            event, irlap_event[event]);
2308
2309                 ret = -EINVAL;
2310                 break;
2311         }
2312         return ret;
2313 }