net/irda/irttp.c

   1 /*********************************************************************
   2  *
   3  * Filename:      irttp.c
   4  * Version:       1.2
   5  * Description:   Tiny Transport Protocol (TTP) implementation
   6  * Status:        Stable
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Sun Aug 31 20:14:31 1997
   9  * Modified at:   Wed Jan  5 11:31:27 2000
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  *
  12  *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
  13  *     All Rights Reserved.
  14  *     Copyright (c) 2000-2001 Jean Tourrilhes <jt@hpl.hp.com>
  15  *
  16  *     This program is free software; you can redistribute it and/or
  17  *     modify it under the terms of the GNU General Public License as
  18  *     published by the Free Software Foundation; either version 2 of
  19  *     the License, or (at your option) any later version.
  20  *
  21  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  22  *     provide warranty for any of this software. This material is
  23  *     provided "AS-IS" and at no charge.
  24  *
  25  ********************************************************************/
  26
  27 #include <linux/config.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/init.h>
  30
  31 #include <asm/byteorder.h>
  32 #include <asm/unaligned.h>
  33
  34 #include <net/irda/irda.h>
  35 #include <net/irda/irmod.h>
  36 #include <net/irda/irlap.h>
  37 #include <net/irda/irlmp.h>
  38 #include <net/irda/parameters.h>
  39 #include <net/irda/irttp.h>
  40
  41 static struct irttp_cb *irttp = NULL;
  42
  43 static void __irttp_close_tsap(struct tsap_cb *self);
  44
  45 static int irttp_data_indication(void *instance, void *sap,
  46                                  struct sk_buff *skb);
  47 static int irttp_udata_indication(void *instance, void *sap,
  48                                   struct sk_buff *skb);
  49 static void irttp_disconnect_indication(void *instance, void *sap,
  50                                         LM_REASON reason, struct sk_buff *);
  51 static void irttp_connect_indication(void *instance, void *sap,
  52                                      struct qos_info *qos, __u32 max_sdu_size,
  53                                      __u8 header_size, struct sk_buff *skb);
  54 static void irttp_connect_confirm(void *instance, void *sap,
  55                                   struct qos_info *qos, __u32 max_sdu_size,
  56                                   __u8 header_size, struct sk_buff *skb);
  57 static void irttp_run_tx_queue(struct tsap_cb *self);
  58 static void irttp_run_rx_queue(struct tsap_cb *self);
  59
  60 static void irttp_flush_queues(struct tsap_cb *self);
  61 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  62 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  63 static void irttp_todo_expired(unsigned long data);
  64 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  65                                     int get);
  66
  67 /* Information for parsing parameters in IrTTP */
  68 static pi_minor_info_t pi_minor_call_table[] = {
  69         { NULL, 0 },                                             /* 0x00 */
  70         { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
  71 };
  72 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  73 static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  74
  75 /************************ GLOBAL PROCEDURES ************************/
  76
  77 /*
  78  * Function irttp_init (void)
  79  *
  80  *    Initialize the IrTTP layer. Called by module initialization code
  81  *
  82  */
  83 int __init irttp_init(void)
  84 {
  85         /* Initialize the irttp structure. */
  86         if (irttp == NULL) {
  87                 irttp = kmalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  88                 if (irttp == NULL)
  89                         return -ENOMEM;
  90         }
  91         memset(irttp, 0, sizeof(struct irttp_cb));
  92
  93         irttp->magic = TTP_MAGIC;
  94
  95         irttp->tsaps = hashbin_new(HB_LOCAL);
  96         if (!irttp->tsaps) {
  97                 ERROR(__FUNCTION__ "(), can't allocate IrTTP hashbin!\n");
  98                 return -ENOMEM;
  99         }
 100
 101         return 0;
 102 }
 103
 104 /*
 105  * Function irttp_cleanup (void)
 106  *
 107  *    Called by module destruction/cleanup code
 108  *
 109  */
 110 #ifdef MODULE
 111 void irttp_cleanup(void)
 112 {
 113         /* Check for main structure */
 114         ASSERT(irttp != NULL, return;);
 115         ASSERT(irttp->magic == TTP_MAGIC, return;);
 116
 117         /*
 118          *  Delete hashbin and close all TSAP instances in it
 119          */
 120         hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
 121
 122         irttp->magic = 0;
 123
 124         /* De-allocate main structure */
 125         kfree(irttp);
 126
 127         irttp = NULL;
 128 }
 129 #endif
 130
 131 /*************************** SUBROUTINES ***************************/
 132
 133 /*
 134  * Function irttp_start_todo_timer (self, timeout)
 135  *
 136  *    Start todo timer.
 137  *
 138  * Made it more effient and unsensitive to race conditions - Jean II
 139  */
 140 static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
 141 {
 142         /* Set new value for timer */
 143         mod_timer(&self->todo_timer, jiffies + timeout);
 144 }
 145
 146 /*
 147  * Function irttp_todo_expired (data)
 148  *
 149  *    Todo timer has expired!
 150  *
 151  * One of the restriction of the timer is that it is run only on the timer
 152  * interrupt which run every 10ms. This mean that even if you set the timer
 153  * with a delay of 0, it may take up to 10ms before it's run.
 154  * So, to minimise latency and keep cache fresh, we try to avoid using
 155  * it as much as possible.
 156  * Note : we can't use tasklets, because they can't be asynchronously
 157  * killed (need user context), and we can't guarantee that here...
 158  * Jean II
 159  */
 160 static void irttp_todo_expired(unsigned long data)
 161 {
 162         struct tsap_cb *self = (struct tsap_cb *) data;
 163
 164         /* Check that we still exist */
 165         if (!self || self->magic != TTP_TSAP_MAGIC)
 166                 return;
 167
 168         IRDA_DEBUG(4, __FUNCTION__ "(instance=%p)\n", self);
 169
 170         /* Try to make some progress, especially on Tx side - Jean II */
 171         irttp_run_rx_queue(self);
 172         irttp_run_tx_queue(self);
 173
 174         /* Check if time for disconnect */
 175         if (test_bit(0, &self->disconnect_pend)) {
 176                 /* Check if it's possible to disconnect yet */
 177                 if (skb_queue_empty(&self->tx_queue)) {
 178                         /* Make sure disconnect is not pending anymore */
 179                         clear_bit(0, &self->disconnect_pend);   /* FALSE */
 180
 181                         /* Note : self->disconnect_skb may be NULL */
 182                         irttp_disconnect_request(self, self->disconnect_skb,
 183                                                  P_NORMAL);
 184                         self->disconnect_skb = NULL;
 185                 } else {
 186                         /* Try again later */
 187                         irttp_start_todo_timer(self, HZ/10);
 188
 189                         /* No reason to try and close now */
 190                         return;
 191                 }
 192         }
 193
 194         /* Check if it's closing time */
 195         if (self->close_pend)
 196                 /* Finish cleanup */
 197                 irttp_close_tsap(self);
 198 }
 199
 200 /*
 201  * Function irttp_flush_queues (self)
 202  *
 203  *     Flushes (removes all frames) in transitt-buffer (tx_list)
 204  */
 205 void irttp_flush_queues(struct tsap_cb *self)
 206 {
 207         struct sk_buff* skb;
 208
 209         IRDA_DEBUG(4, __FUNCTION__ "()\n");
 210
 211         ASSERT(self != NULL, return;);
 212         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 213
 214         /* Deallocate frames waiting to be sent */
 215         while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
 216                 dev_kfree_skb(skb);
 217
 218         /* Deallocate received frames */
 219         while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
 220                 dev_kfree_skb(skb);
 221
 222         /* Deallocate received fragments */
 223         while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
 224                 dev_kfree_skb(skb);
 225 }
 226
 227 /*
 228  * Function irttp_reassemble (self)
 229  *
 230  *    Makes a new (continuous) skb of all the fragments in the fragment
 231  *    queue
 232  *
 233  */
 234 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
 235 {
 236         struct sk_buff *skb, *frag;
 237         int n = 0;  /* Fragment index */
 238
 239         ASSERT(self != NULL, return NULL;);
 240         ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
 241
 242         IRDA_DEBUG(2, __FUNCTION__ "(), self->rx_sdu_size=%d\n",
 243                    self->rx_sdu_size);
 244
 245         skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
 246         if (!skb)
 247                 return NULL;
 248
 249         /*
 250          * Need to reserve space for TTP header in case this skb needs to
 251          * be requeued in case delivery failes
 252          */
 253         skb_reserve(skb, TTP_HEADER);
 254         skb_put(skb, self->rx_sdu_size);
 255
 256         /*
 257          *  Copy all fragments to a new buffer
 258          */
 259         while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
 260                 memcpy(skb->data+n, frag->data, frag->len);
 261                 n += frag->len;
 262
 263                 dev_kfree_skb(frag);
 264         }
 265         IRDA_DEBUG(2, __FUNCTION__ "(), frame len=%d\n", n);
 266
 267         IRDA_DEBUG(2, __FUNCTION__ "(), rx_sdu_size=%d\n", self->rx_sdu_size);
 268         ASSERT(n <= self->rx_sdu_size, return NULL;);
 269
 270         /* Set the new length */
 271         skb_trim(skb, n);
 272
 273         self->rx_sdu_size = 0;
 274
 275         return skb;
 276 }
 277
 278 /*
 279  * Function irttp_fragment_skb (skb)
 280  *
 281  *    Fragments a frame and queues all the fragments for transmission
 282  *
 283  */
 284 static inline void irttp_fragment_skb(struct tsap_cb *self,
 285                                       struct sk_buff *skb)
 286 {
 287         struct sk_buff *frag;
 288         __u8 *frame;
 289
 290         IRDA_DEBUG(2, __FUNCTION__ "()\n");
 291
 292         ASSERT(self != NULL, return;);
 293         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 294         ASSERT(skb != NULL, return;);
 295
 296         /*
 297          *  Split frame into a number of segments
 298          */
 299         while (skb->len > self->max_seg_size) {
 300                 IRDA_DEBUG(2, __FUNCTION__  "(), fragmenting ...\n");
 301
 302                 /* Make new segment */
 303                 frag = dev_alloc_skb(self->max_seg_size+self->max_header_size);
 304                 if (!frag)
 305                         return;
 306
 307                 skb_reserve(frag, self->max_header_size);
 308
 309                 /* Copy data from the original skb into this fragment. */
 310                 memcpy(skb_put(frag, self->max_seg_size), skb->data,
 311                        self->max_seg_size);
 312
 313                 /* Insert TTP header, with the more bit set */
 314                 frame = skb_push(frag, TTP_HEADER);
 315                 frame[0] = TTP_MORE;
 316
 317                 /* Hide the copied data from the original skb */
 318                 skb_pull(skb, self->max_seg_size);
 319
 320                 /* Queue fragment */
 321                 skb_queue_tail(&self->tx_queue, frag);
 322         }
 323         /* Queue what is left of the original skb */
 324         IRDA_DEBUG(2, __FUNCTION__  "(), queuing last segment\n");
 325
 326         frame = skb_push(skb, TTP_HEADER);
 327         frame[0] = 0x00; /* Clear more bit */
 328
 329         /* Queue fragment */
 330         skb_queue_tail(&self->tx_queue, skb);
 331 }
 332
 333 /*
 334  * Function irttp_param_max_sdu_size (self, param)
 335  *
 336  *    Handle the MaxSduSize parameter in the connect frames, this function
 337  *    will be called both when this parameter needs to be inserted into, and
 338  *    extracted from the connect frames
 339  */
 340 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 341                                     int get)
 342 {
 343         struct tsap_cb *self;
 344
 345         self = (struct tsap_cb *) instance;
 346
 347         ASSERT(self != NULL, return -1;);
 348         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 349
 350         if (get)
 351                 param->pv.i = self->tx_max_sdu_size;
 352         else
 353                 self->tx_max_sdu_size = param->pv.i;
 354
 355         IRDA_DEBUG(1, __FUNCTION__ "(), MaxSduSize=%d\n", param->pv.i);
 356
 357         return 0;
 358 }
 359
 360 /*************************** CLIENT CALLS ***************************/
 361 /************************** LMP CALLBACKS **************************/
 362 /* Everything is happily mixed up. Waiting for next clean up - Jean II */
 363
 364 /*
 365  * Function irttp_open_tsap (stsap, notify)
 366  *
 367  *    Create TSAP connection endpoint,
 368  */
 369 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 370 {
 371         struct tsap_cb *self;
 372         struct lsap_cb *lsap;
 373         notify_t ttp_notify;
 374
 375         ASSERT(irttp != NULL, return NULL;);
 376         ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 377
 378         /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 379          * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 380          * JeanII */
 381         if((stsap_sel != LSAP_ANY) &&
 382            ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 383                 IRDA_DEBUG(0, __FUNCTION__ "(), invalid tsap!\n");
 384                 return NULL;
 385         }
 386
 387         self = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 388         if (self == NULL) {
 389                 IRDA_DEBUG(0, __FUNCTION__ "(), unable to kmalloc!\n");
 390                 return NULL;
 391         }
 392         memset(self, 0, sizeof(struct tsap_cb));
 393         spin_lock_init(&self->lock);
 394
 395         /* Initialise todo timer */
 396         init_timer(&self->todo_timer);
 397         self->todo_timer.data     = (unsigned long) self;
 398         self->todo_timer.function = &irttp_todo_expired;
 399
 400         /* Initialize callbacks for IrLMP to use */
 401         irda_notify_init(&ttp_notify);
 402         ttp_notify.connect_confirm = irttp_connect_confirm;
 403         ttp_notify.connect_indication = irttp_connect_indication;
 404         ttp_notify.disconnect_indication = irttp_disconnect_indication;
 405         ttp_notify.data_indication = irttp_data_indication;
 406         ttp_notify.udata_indication = irttp_udata_indication;
 407         ttp_notify.flow_indication = irttp_flow_indication;
 408         if(notify->status_indication != NULL)
 409                 ttp_notify.status_indication = irttp_status_indication;
 410         ttp_notify.instance = self;
 411         strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 412
 413         self->magic = TTP_TSAP_MAGIC;
 414         self->connected = FALSE;
 415
 416         skb_queue_head_init(&self->rx_queue);
 417         skb_queue_head_init(&self->tx_queue);
 418         skb_queue_head_init(&self->rx_fragments);
 419         /*
 420          *  Create LSAP at IrLMP layer
 421          */
 422         lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 423         if (lsap == NULL) {
 424                 WARNING(__FUNCTION__ "(), unable to allocate LSAP!!\n");
 425                 return NULL;
 426         }
 427
 428         /*
 429          *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 430          *  will replace it with whatever source selector which is free, so
 431          *  the stsap_sel we have might not be valid anymore
 432          */
 433         self->stsap_sel = lsap->slsap_sel;
 434         IRDA_DEBUG(4, __FUNCTION__ "(), stsap_sel=%02x\n", self->stsap_sel);
 435
 436         self->notify = *notify;
 437         self->lsap = lsap;
 438
 439         hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (int) self, NULL);
 440
 441         if (credit > TTP_RX_MAX_CREDIT)
 442                 self->initial_credit = TTP_RX_MAX_CREDIT;
 443         else
 444                 self->initial_credit = credit;
 445
 446         return self;
 447 }
 448
 449 /*
 450  * Function irttp_close (handle)
 451  *
 452  *    Remove an instance of a TSAP. This function should only deal with the
 453  *    deallocation of the TSAP, and resetting of the TSAPs values;
 454  *
 455  */
 456 static void __irttp_close_tsap(struct tsap_cb *self)
 457 {
 458         /* First make sure we're connected. */
 459         ASSERT(self != NULL, return;);
 460         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 461
 462         irttp_flush_queues(self);
 463
 464         del_timer(&self->todo_timer);
 465
 466         /* This one won't be cleaned up if we are disconnect_pend + close_pend
 467          * and we receive a disconnect_indication */
 468         if (self->disconnect_skb)
 469                 dev_kfree_skb(self->disconnect_skb);
 470
 471         self->connected = FALSE;
 472         self->magic = ~TTP_TSAP_MAGIC;
 473
 474         kfree(self);
 475 }
 476
 477 /*
 478  * Function irttp_close (self)
 479  *
 480  *    Remove TSAP from list of all TSAPs and then deallocate all resources
 481  *    associated with this TSAP
 482  *
 483  * Note : because we *free* the tsap structure, it is the responsability
 484  * of the caller to make sure we are called only once and to deal with
 485  * possible race conditions. - Jean II
 486  */
 487 int irttp_close_tsap(struct tsap_cb *self)
 488 {
 489         struct tsap_cb *tsap;
 490
 491         IRDA_DEBUG(4, __FUNCTION__ "()\n");
 492
 493         ASSERT(self != NULL, return -1;);
 494         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 495
 496         /* Make sure tsap has been disconnected */
 497         if (self->connected) {
 498                 /* Check if disconnect is not pending */
 499                 if (!test_bit(0, &self->disconnect_pend)) {
 500                         WARNING(__FUNCTION__ "(), TSAP still connected!\n");
 501                         irttp_disconnect_request(self, NULL, P_NORMAL);
 502                 }
 503                 self->close_pend = TRUE;
 504                 irttp_start_todo_timer(self, HZ/10);
 505
 506                 return 0; /* Will be back! */
 507         }
 508
 509         tsap = hashbin_remove(irttp->tsaps, (int) self, NULL);
 510
 511         ASSERT(tsap == self, return -1;);
 512
 513         /* Close corresponding LSAP */
 514         if (self->lsap) {
 515                 irlmp_close_lsap(self->lsap);
 516                 self->lsap = NULL;
 517         }
 518
 519         __irttp_close_tsap(self);
 520
 521         return 0;
 522 }
 523
 524 /*
 525  * Function irttp_udata_request (self, skb)
 526  *
 527  *    Send unreliable data on this TSAP
 528  *
 529  */
 530 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 531 {
 532         ASSERT(self != NULL, return -1;);
 533         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 534         ASSERT(skb != NULL, return -1;);
 535
 536         IRDA_DEBUG(4, __FUNCTION__ "()\n");
 537
 538         /* Check that nothing bad happens */
 539         if ((skb->len == 0) || (!self->connected)) {
 540                 IRDA_DEBUG(1, __FUNCTION__ "(), No data, or not connected\n");
 541                 return -1;
 542         }
 543
 544         if (skb->len > self->max_seg_size) {
 545                 IRDA_DEBUG(1, __FUNCTION__ "(), UData is to large for IrLAP!\n");
 546                 return -1;
 547         }
 548
 549         irlmp_udata_request(self->lsap, skb);
 550         self->stats.tx_packets++;
 551
 552         return 0;
 553 }
 554
 555 /*
 556  * Function irttp_data_request (handle, skb)
 557  *
 558  *    Queue frame for transmission. If SAR is enabled, fragement the frame
 559  *    and queue the fragments for transmission
 560  */
 561 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 562 {
 563         __u8 *frame;
 564
 565         ASSERT(self != NULL, return -1;);
 566         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 567         ASSERT(skb != NULL, return -1;);
 568
 569         IRDA_DEBUG(2, __FUNCTION__ " : queue len = %d\n",
 570                    skb_queue_len(&self->tx_queue));
 571
 572         /* Check that nothing bad happens */
 573         if ((skb->len == 0) || (!self->connected)) {
 574                 WARNING(__FUNCTION__ "(), No data, or not connected\n");
 575                 return -ENOTCONN;
 576         }
 577
 578         /*
 579          *  Check if SAR is disabled, and the frame is larger than what fits
 580          *  inside an IrLAP frame
 581          */
 582         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 583                 ERROR(__FUNCTION__
 584                       "(), SAR disabled, and data is to large for IrLAP!\n");
 585                 return -EMSGSIZE;
 586         }
 587
 588         /*
 589          *  Check if SAR is enabled, and the frame is larger than the
 590          *  TxMaxSduSize
 591          */
 592         if ((self->tx_max_sdu_size != 0) &&
 593             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 594             (skb->len > self->tx_max_sdu_size))
 595         {
 596                 ERROR(__FUNCTION__ "(), SAR enabled, "
 597                       "but data is larger than TxMaxSduSize!\n");
 598                 return -EMSGSIZE;
 599         }
 600         /*
 601          *  Check if transmit queue is full
 602          */
 603         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 604                 /*
 605                  *  Give it a chance to empty itself
 606                  */
 607                 irttp_run_tx_queue(self);
 608
 609                 /* Drop packet. This error code should trigger the caller
 610                  * to requeue the packet in the client code - Jean II */
 611                 return -ENOBUFS;
 612         }
 613
 614         /* Queue frame, or queue frame segments */
 615         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 616                 /* Queue frame */
 617                 ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 618                 frame = skb_push(skb, TTP_HEADER);
 619                 frame[0] = 0x00; /* Clear more bit */
 620
 621                 skb_queue_tail(&self->tx_queue, skb);
 622         } else {
 623                 /*
 624                  *  Fragment the frame, this function will also queue the
 625                  *  fragments, we don't care about the fact the transmit
 626                  *  queue may be overfilled by all the segments for a little
 627                  *  while
 628                  */
 629                 irttp_fragment_skb(self, skb);
 630         }
 631
 632         /* Check if we can accept more data from client */
 633         if ((!self->tx_sdu_busy) &&
 634             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 635                 /* Tx queue filling up, so stop client. */
 636                 if (self->notify.flow_indication) {
 637                         self->notify.flow_indication(self->notify.instance,
 638                                                      self, FLOW_STOP);
 639                 }
 640                 /* self->tx_sdu_busy is the state of the client.
 641                  * Update state after notifying client to avoid
 642                  * race condition with irttp_flow_indication().
 643                  * If the queue empty itself after our test but before
 644                  * we set the flag, we will fix ourselves below in
 645                  * irttp_run_tx_queue().
 646                  * Jean II */
 647                 self->tx_sdu_busy = TRUE;
 648         }
 649
 650         /* Try to make some progress */
 651         irttp_run_tx_queue(self);
 652
 653         return 0;
 654 }
 655
 656 /*
 657  * Function irttp_run_tx_queue (self)
 658  *
 659  *    Transmit packets queued for transmission (if possible)
 660  *
 661  */
 662 static void irttp_run_tx_queue(struct tsap_cb *self)
 663 {
 664         struct sk_buff *skb;
 665         unsigned long flags;
 666         int n;
 667
 668         IRDA_DEBUG(2, __FUNCTION__ "() : send_credit = %d, queue_len = %d\n",
 669                    self->send_credit, skb_queue_len(&self->tx_queue));
 670
 671         /* Get exclusive access to the tx queue, otherwise don't touch it */
 672         if (irda_lock(&self->tx_queue_lock) == FALSE)
 673                 return;
 674
 675         /* Try to send out frames as long as we have credits
 676          * and as long as LAP is not full. If LAP is full, it will
 677          * poll us through irttp_flow_indication() - Jean II */
 678         while ((self->send_credit > 0) &&
 679                (!irlmp_lap_tx_queue_full(self->lsap)) &&
 680                (skb = skb_dequeue(&self->tx_queue)))
 681         {
 682                 /*
 683                  *  Since we can transmit and receive frames concurrently,
 684                  *  the code below is a critical region and we must assure that
 685                  *  nobody messes with the credits while we update them.
 686                  */
 687                 spin_lock_irqsave(&self->lock, flags);
 688
 689                 n = self->avail_credit;
 690                 self->avail_credit = 0;
 691
 692                 /* Only room for 127 credits in frame */
 693                 if (n > 127) {
 694                         self->avail_credit = n-127;
 695                         n = 127;
 696                 }
 697                 self->remote_credit += n;
 698                 self->send_credit--;
 699
 700                 spin_unlock_irqrestore(&self->lock, flags);
 701
 702                 /*
 703                  *  More bit must be set by the data_request() or fragment()
 704                  *  functions
 705                  */
 706                 skb->data[0] |= (n & 0x7f);
 707
 708                 /* Detach from socket.
 709                  * The current skb has a reference to the socket that sent
 710                  * it (skb->sk). When we pass it to IrLMP, the skb will be
 711                  * stored in in IrLAP (self->wx_list). When we are within
 712                  * IrLAP, we loose the notion of socket, so we should not
 713                  * have a reference to a socket. So, we drop it here.
 714                  *
 715                  * Why does it matter ?
 716                  * When the skb is freed (kfree_skb), if it is associated
 717                  * with a socket, it release buffer space on the socket
 718                  * (through sock_wfree() and sock_def_write_space()).
 719                  * If the socket no longer exist, we may crash. Hard.
 720                  * When we close a socket, we make sure that associated packets
 721                  * in IrTTP are freed. However, we have no way to cancel
 722                  * the packet that we have passed to IrLAP. So, if a packet
 723                  * remains in IrLAP (retry on the link or else) after we
 724                  * close the socket, we are dead !
 725                  * Jean II */
 726                 if (skb->sk != NULL) {
 727                         /* IrSOCK application, IrOBEX, ... */
 728                         skb_orphan(skb);
 729                 }
 730                         /* IrCOMM over IrTTP, IrLAN, ... */
 731
 732                 /* Pass the skb to IrLMP - done */
 733                 irlmp_data_request(self->lsap, skb);
 734                 self->stats.tx_packets++;
 735         }
 736
 737         /* Check if we can accept more frames from client.
 738          * We don't want to wait until the todo timer to do that, and we
 739          * can't use tasklets (grr...), so we are obliged to give control
 740          * to client. That's ok, this test will be true not too often
 741          * (max once per LAP window) and we are called from places
 742          * where we can spend a bit of time doing stuff. - Jean II */
 743         if ((self->tx_sdu_busy) &&
 744             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 745             (!self->close_pend))
 746         {
 747                 if (self->notify.flow_indication)
 748                         self->notify.flow_indication(self->notify.instance,
 749                                                      self, FLOW_START);
 750
 751                 /* self->tx_sdu_busy is the state of the client.
 752                  * We don't really have a race here, but it's always safer
 753                  * to update our state after the client - Jean II */
 754                 self->tx_sdu_busy = FALSE;
 755         }
 756
 757         /* Reset lock */
 758         self->tx_queue_lock = 0;
 759 }
 760
 761 /*
 762  * Function irttp_give_credit (self)
 763  *
 764  *    Send a dataless flowdata TTP-PDU and give available credit to peer
 765  *    TSAP
 766  */
 767 static inline void irttp_give_credit(struct tsap_cb *self)
 768 {
 769         struct sk_buff *tx_skb = NULL;
 770         unsigned long flags;
 771         int n;
 772
 773         ASSERT(self != NULL, return;);
 774         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 775
 776         IRDA_DEBUG(4, __FUNCTION__ "() send=%d,avail=%d,remote=%d\n",
 777                    self->send_credit, self->avail_credit, self->remote_credit);
 778
 779         /* Give credit to peer */
 780         tx_skb = dev_alloc_skb(64);
 781         if (!tx_skb)
 782                 return;
 783
 784         /* Reserve space for LMP, and LAP header */
 785         skb_reserve(tx_skb, self->max_header_size);
 786
 787         /*
 788          *  Since we can transmit and receive frames concurrently,
 789          *  the code below is a critical region and we must assure that
 790          *  nobody messes with the credits while we update them.
 791          */
 792         spin_lock_irqsave(&self->lock, flags);
 793
 794         n = self->avail_credit;
 795         self->avail_credit = 0;
 796
 797         /* Only space for 127 credits in frame */
 798         if (n > 127) {
 799                 self->avail_credit = n - 127;
 800                 n = 127;
 801         }
 802         self->remote_credit += n;
 803
 804         spin_unlock_irqrestore(&self->lock, flags);
 805
 806         skb_put(tx_skb, 1);
 807         tx_skb->data[0] = (__u8) (n & 0x7f);
 808
 809         irlmp_data_request(self->lsap, tx_skb);
 810         self->stats.tx_packets++;
 811 }
 812
 813 /*
 814  * Function irttp_udata_indication (instance, sap, skb)
 815  *
 816  *    Received some unit-data (unreliable)
 817  *
 818  */
 819 static int irttp_udata_indication(void *instance, void *sap,
 820                                   struct sk_buff *skb)
 821 {
 822         struct tsap_cb *self;
 823
 824         IRDA_DEBUG(4, __FUNCTION__ "()\n");
 825
 826         self = (struct tsap_cb *) instance;
 827
 828         ASSERT(self != NULL, return -1;);
 829         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 830         ASSERT(skb != NULL, return -1;);
 831
 832         /* Just pass data to layer above */
 833         if (self->notify.udata_indication)
 834                 self->notify.udata_indication(self->notify.instance, self,skb);
 835         else
 836                 dev_kfree_skb(skb);
 837
 838         self->stats.rx_packets++;
 839
 840         return 0;
 841 }
 842
 843 /*
 844  * Function irttp_data_indication (instance, sap, skb)
 845  *
 846  *    Receive segment from IrLMP.
 847  *
 848  */
 849 static int irttp_data_indication(void *instance, void *sap,
 850                                  struct sk_buff *skb)
 851 {
 852         struct tsap_cb *self;
 853         unsigned long flags;
 854         int n;
 855
 856         self = (struct tsap_cb *) instance;
 857
 858         n = skb->data[0] & 0x7f;     /* Extract the credits */
 859
 860         self->stats.rx_packets++;
 861
 862         /*  Deal with inbound credit
 863          *  Since we can transmit and receive frames concurrently,
 864          *  the code below is a critical region and we must assure that
 865          *  nobody messes with the credits while we update them.
 866          */
 867         spin_lock_irqsave(&self->lock, flags);
 868         self->send_credit += n;
 869         if (skb->len > 1)
 870                 self->remote_credit--;
 871         spin_unlock_irqrestore(&self->lock, flags);
 872
 873         /*
 874          *  Data or dataless packet? Dataless frames contains only the
 875          *  TTP_HEADER.
 876          */
 877         if (skb->len > 1) {
 878                 /*
 879                  *  We don't remove the TTP header, since we must preserve the
 880                  *  more bit, so the defragment routing knows what to do
 881                  */
 882                 skb_queue_tail(&self->rx_queue, skb);
 883         } else {
 884                 /* Dataless flowdata TTP-PDU */
 885                 dev_kfree_skb(skb);
 886         }
 887
 888
 889         /* Push data to the higher layer.
 890          * We do it synchronously because running the todo timer for each
 891          * receive packet would be too much overhead and latency.
 892          * By passing control to the higher layer, we run the risk that
 893          * it may take time or grab a lock. Most often, the higher layer
 894          * will only put packet in a queue.
 895          * Anyway, packets are only dripping through the IrDA, so we can
 896          * have time before the next packet.
 897          * Further, we are run from NET_BH, so the worse that can happen is
 898          * us missing the optimal time to send back the PF bit in LAP.
 899          * Jean II */
 900         irttp_run_rx_queue(self);
 901
 902         /* We now give credits to peer in irttp_run_rx_queue().
 903          * We need to send credit *NOW*, otherwise we are going
 904          * to miss the next Tx window. The todo timer may take
 905          * a while before it's run... - Jean II */
 906
 907         /*
 908          * If the peer device has given us some credits and we didn't have
 909          * anyone from before, then we need to shedule the tx queue.
 910          * We need to do that because our Tx have stopped (so we may not
 911          * get any LAP flow indication) and the user may be stopped as
 912          * well. - Jean II
 913          */
 914         if (self->send_credit == n) {
 915                 /* Restart pushing stuff to LAP */
 916                 irttp_run_tx_queue(self);
 917                 /* Note : we don't want to schedule the todo timer
 918                  * because it has horrible latency. No tasklets
 919                  * because the tasklet API is broken. - Jean II */
 920         }
 921
 922         return 0;
 923 }
 924
 925 /*
 926  * Function irttp_status_indication (self, reason)
 927  *
 928  *    Status_indication, just pass to the higher layer...
 929  *
 930  */
 931 void irttp_status_indication(void *instance,
 932                              LINK_STATUS link, LOCK_STATUS lock)
 933 {
 934         struct tsap_cb *self;
 935
 936         IRDA_DEBUG(4, __FUNCTION__ "()\n");
 937
 938         self = (struct tsap_cb *) instance;
 939
 940         ASSERT(self != NULL, return;);
 941         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 942
 943         /*
 944          *  Inform service user if he has requested it
 945          */
 946         if (self->notify.status_indication != NULL)
 947                 self->notify.status_indication(self->notify.instance,
 948                                                link, lock);
 949         else
 950                 IRDA_DEBUG(2, __FUNCTION__ "(), no handler\n");
 951 }
 952
 953 /*
 954  * Function irttp_flow_indication (self, reason)
 955  *
 956  *    Flow_indication : IrLAP tells us to send more data.
 957  *
 958  */
 959 void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
 960 {
 961         struct tsap_cb *self;
 962
 963         self = (struct tsap_cb *) instance;
 964
 965         ASSERT(self != NULL, return;);
 966         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 967
 968         IRDA_DEBUG(4, __FUNCTION__ "(instance=%p)\n", self);
 969
 970         /* We are "polled" directly from LAP, and the LAP want to fill
 971          * its Tx window. We want to do our best to send it data, so that
 972          * we maximise the window. On the other hand, we want to limit the
 973          * amount of work here so that LAP doesn't hang forever waiting
 974          * for packets. - Jean II */
 975
 976         /* Try to send some packets. Currently, LAP calls us every time
 977          * there is one free slot, so we will send only one packet.
 978          * This allow the scheduler to do its round robin - Jean II */
 979         irttp_run_tx_queue(self);
 980
 981         /* Note regarding the interraction with higher layer.
 982          * irttp_run_tx_queue() may call the client when its queue
 983          * start to empty, via notify.flow_indication(). Initially.
 984          * I wanted this to happen in a tasklet, to avoid client
 985          * grabbing the CPU, but we can't use tasklets safely. And timer
 986          * is definitely too slow.
 987          * This will happen only once per LAP window, and usually at
 988          * the third packet (unless window is smaller). LAP is still
 989          * doing mtt and sending first packet so it's sort of OK
 990          * to do that. Jean II */
 991
 992         /* If we need to send disconnect. try to do it now */
 993         if(self->disconnect_pend)
 994                 irttp_start_todo_timer(self, 0);
 995 }
 996
 997 /*
 998  * Function irttp_flow_request (self, command)
 999  *
1000  *    This funtion could be used by the upper layers to tell IrTTP to stop
1001  *    delivering frames if the receive queues are starting to get full, or
1002  *    to tell IrTTP to start delivering frames again.
1003  */
1004 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1005 {
1006         IRDA_DEBUG(1, __FUNCTION__ "()\n");
1007
1008         ASSERT(self != NULL, return;);
1009         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1010
1011         switch (flow) {
1012         case FLOW_STOP:
1013                 IRDA_DEBUG(1, __FUNCTION__ "(), flow stop\n");
1014                 self->rx_sdu_busy = TRUE;
1015                 break;
1016         case FLOW_START:
1017                 IRDA_DEBUG(1, __FUNCTION__ "(), flow start\n");
1018                 self->rx_sdu_busy = FALSE;
1019
1020                 /* Client say he can accept more data, try to free our
1021                  * queues ASAP - Jean II */
1022                 irttp_run_rx_queue(self);
1023
1024                 break;
1025         default:
1026                 IRDA_DEBUG(1, __FUNCTION__ "(), Unknown flow command!\n");
1027         }
1028 }
1029
1030 /*
1031  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1032  *
1033  *    Try to connect to remote destination TSAP selector
1034  *
1035  */
1036 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1037                           __u32 saddr, __u32 daddr,
1038                           struct qos_info *qos, __u32 max_sdu_size,
1039                           struct sk_buff *userdata)
1040 {
1041         struct sk_buff *skb;
1042         __u8 *frame;
1043         __u8 n;
1044
1045         IRDA_DEBUG(4, __FUNCTION__ "(), max_sdu_size=%d\n", max_sdu_size);
1046
1047         ASSERT(self != NULL, return -EBADR;);
1048         ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1049
1050         if (self->connected)
1051                 return -EISCONN;
1052
1053         /* Any userdata supplied? */
1054         if (userdata == NULL) {
1055                 skb = dev_alloc_skb(64);
1056                 if (!skb)
1057                         return -ENOMEM;
1058
1059                 /* Reserve space for MUX_CONTROL and LAP header */
1060                 skb_reserve(skb, TTP_MAX_HEADER);
1061         } else {
1062                 skb = userdata;
1063                 /*
1064                  *  Check that the client has reserved enough space for
1065                  *  headers
1066                  */
1067                 ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER, return -1;);
1068         }
1069
1070         /* Initialize connection parameters */
1071         self->connected = FALSE;
1072         self->avail_credit = 0;
1073         self->rx_max_sdu_size = max_sdu_size;
1074         self->rx_sdu_size = 0;
1075         self->rx_sdu_busy = FALSE;
1076         self->dtsap_sel = dtsap_sel;
1077
1078         n = self->initial_credit;
1079
1080         self->remote_credit = 0;
1081         self->send_credit = 0;
1082
1083         /*
1084          *  Give away max 127 credits for now
1085          */
1086         if (n > 127) {
1087                 self->avail_credit=n-127;
1088                 n = 127;
1089         }
1090
1091         self->remote_credit = n;
1092
1093         /* SAR enabled? */
1094         if (max_sdu_size > 0) {
1095                 ASSERT(skb_headroom(skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1096                        return -1;);
1097
1098                 /* Insert SAR parameters */
1099                 frame = skb_push(skb, TTP_HEADER+TTP_SAR_HEADER);
1100
1101                 frame[0] = TTP_PARAMETERS | n;
1102                 frame[1] = 0x04; /* Length */
1103                 frame[2] = 0x01; /* MaxSduSize */
1104                 frame[3] = 0x02; /* Value length */
1105
1106                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1107                               (__u16 *)(frame+4));
1108         } else {
1109                 /* Insert plain TTP header */
1110                 frame = skb_push(skb, TTP_HEADER);
1111
1112                 /* Insert initial credit in frame */
1113                 frame[0] = n & 0x7f;
1114         }
1115
1116         /* Connect with IrLMP. No QoS parameters for now */
1117         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1118                                      skb);
1119 }
1120
1121 /*
1122  * Function irttp_connect_confirm (handle, qos, skb)
1123  *
1124  *    Sevice user confirms TSAP connection with peer.
1125  *
1126  */
1127 static void irttp_connect_confirm(void *instance, void *sap,
1128                                   struct qos_info *qos, __u32 max_seg_size,
1129                                   __u8 max_header_size, struct sk_buff *skb)
1130 {
1131         struct tsap_cb *self;
1132         int parameters;
1133         int ret;
1134         __u8 plen;
1135         __u8 n;
1136
1137         IRDA_DEBUG(4, __FUNCTION__ "()\n");
1138
1139         self = (struct tsap_cb *) instance;
1140
1141         ASSERT(self != NULL, return;);
1142         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1143         ASSERT(skb != NULL, return;);
1144
1145         self->max_seg_size = max_seg_size - TTP_HEADER;
1146         self->max_header_size = max_header_size + TTP_HEADER;
1147
1148         /*
1149          *  Check if we have got some QoS parameters back! This should be the
1150          *  negotiated QoS for the link.
1151          */
1152         if (qos) {
1153                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1154                        qos->baud_rate.bits);
1155                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1156                        qos->baud_rate.value);
1157         }
1158
1159         n = skb->data[0] & 0x7f;
1160
1161         IRDA_DEBUG(4, __FUNCTION__ "(), Initial send_credit=%d\n", n);
1162
1163         self->send_credit = n;
1164         self->tx_max_sdu_size = 0;
1165         self->connected = TRUE;
1166
1167         parameters = skb->data[0] & 0x80;
1168
1169         ASSERT(skb->len >= TTP_HEADER, return;);
1170         skb_pull(skb, TTP_HEADER);
1171
1172         if (parameters) {
1173                 plen = skb->data[0];
1174
1175                 ret = irda_param_extract_all(self, skb->data+1,
1176                                              IRDA_MIN(skb->len-1, plen),
1177                                              &param_info);
1178
1179                 /* Any errors in the parameter list? */
1180                 if (ret < 0) {
1181                         WARNING(__FUNCTION__
1182                                 "(), error extracting parameters\n");
1183                         dev_kfree_skb(skb);
1184
1185                         /* Do not accept this connection attempt */
1186                         return;
1187                 }
1188                 /* Remove parameters */
1189                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1190         }
1191
1192         IRDA_DEBUG(4, __FUNCTION__ "() send=%d,avail=%d,remote=%d\n",
1193               self->send_credit, self->avail_credit, self->remote_credit);
1194
1195         IRDA_DEBUG(2, __FUNCTION__ "(), MaxSduSize=%d\n", self->tx_max_sdu_size);
1196
1197         if (self->notify.connect_confirm) {
1198                 self->notify.connect_confirm(self->notify.instance, self, qos,
1199                                              self->tx_max_sdu_size,
1200                                              self->max_header_size, skb);
1201         }
1202 }
1203
1204 /*
1205  * Function irttp_connect_indication (handle, skb)
1206  *
1207  *    Some other device is connecting to this TSAP
1208  *
1209  */
1210 void irttp_connect_indication(void *instance, void *sap, struct qos_info *qos,
1211                               __u32 max_seg_size, __u8 max_header_size,
1212                               struct sk_buff *skb)
1213 {
1214         struct tsap_cb *self;
1215         struct lsap_cb *lsap;
1216         int parameters;
1217         int ret;
1218         __u8 plen;
1219         __u8 n;
1220
1221         self = (struct tsap_cb *) instance;
1222
1223         ASSERT(self != NULL, return;);
1224         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1225         ASSERT(skb != NULL, return;);
1226
1227         lsap = (struct lsap_cb *) sap;
1228
1229         self->max_seg_size = max_seg_size - TTP_HEADER;;
1230         self->max_header_size = max_header_size+TTP_HEADER;
1231
1232         IRDA_DEBUG(4, __FUNCTION__ "(), TSAP sel=%02x\n", self->stsap_sel);
1233
1234         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1235         self->dtsap_sel = lsap->dlsap_sel;
1236
1237         n = skb->data[0] & 0x7f;
1238
1239         self->send_credit = n;
1240         self->tx_max_sdu_size = 0;
1241
1242         parameters = skb->data[0] & 0x80;
1243
1244         ASSERT(skb->len >= TTP_HEADER, return;);
1245         skb_pull(skb, TTP_HEADER);
1246
1247         if (parameters) {
1248                 plen = skb->data[0];
1249
1250                 ret = irda_param_extract_all(self, skb->data+1,
1251                                              IRDA_MIN(skb->len-1, plen),
1252                                              &param_info);
1253
1254                 /* Any errors in the parameter list? */
1255                 if (ret < 0) {
1256                         WARNING(__FUNCTION__
1257                                 "(), error extracting parameters\n");
1258                         dev_kfree_skb(skb);
1259
1260                         /* Do not accept this connection attempt */
1261                         return;
1262                 }
1263
1264                 /* Remove parameters */
1265                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1266         }
1267
1268         if (self->notify.connect_indication) {
1269                 self->notify.connect_indication(self->notify.instance, self,
1270                                                 qos, self->tx_max_sdu_size,
1271                                                 self->max_header_size, skb);
1272         } else
1273                 dev_kfree_skb(skb);
1274 }
1275
1276 /*
1277  * Function irttp_connect_response (handle, userdata)
1278  *
1279  *    Service user is accepting the connection, just pass it down to
1280  *    IrLMP!
1281  *
1282  */
1283 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1284                            struct sk_buff *userdata)
1285 {
1286         struct sk_buff *skb;
1287         __u8 *frame;
1288         int ret;
1289         __u8 n;
1290
1291         ASSERT(self != NULL, return -1;);
1292         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1293
1294         IRDA_DEBUG(4, __FUNCTION__ "(), Source TSAP selector=%02x\n",
1295                    self->stsap_sel);
1296
1297         /* Any userdata supplied? */
1298         if (userdata == NULL) {
1299                 skb = dev_alloc_skb(64);
1300                 if (!skb)
1301                         return -ENOMEM;
1302
1303                 /* Reserve space for MUX_CONTROL and LAP header */
1304                 skb_reserve(skb, TTP_MAX_HEADER);
1305         } else {
1306                 skb = userdata;
1307                 /*
1308                  *  Check that the client has reserved enough space for
1309                  *  headers
1310                  */
1311                 ASSERT(skb_headroom(skb) >= TTP_MAX_HEADER, return -1;);
1312         }
1313
1314         self->avail_credit = 0;
1315         self->remote_credit = 0;
1316         self->rx_max_sdu_size = max_sdu_size;
1317         self->rx_sdu_size = 0;
1318         self->rx_sdu_busy = FALSE;
1319
1320         n = self->initial_credit;
1321
1322         /* Frame has only space for max 127 credits (7 bits) */
1323         if (n > 127) {
1324                 self->avail_credit = n - 127;
1325                 n = 127;
1326         }
1327
1328         self->remote_credit = n;
1329         self->connected = TRUE;
1330
1331         /* SAR enabled? */
1332         if (max_sdu_size > 0) {
1333                 ASSERT(skb_headroom(skb) >= (TTP_MAX_HEADER+TTP_SAR_HEADER),
1334                        return -1;);
1335
1336                 /* Insert TTP header with SAR parameters */
1337                 frame = skb_push(skb, TTP_HEADER+TTP_SAR_HEADER);
1338
1339                 frame[0] = TTP_PARAMETERS | n;
1340                 frame[1] = 0x04; /* Length */
1341
1342                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1343 /*                                TTP_SAR_HEADER, &param_info) */
1344
1345                 frame[2] = 0x01; /* MaxSduSize */
1346                 frame[3] = 0x02; /* Value length */
1347
1348                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1349                               (__u16 *)(frame+4));
1350         } else {
1351                 /* Insert TTP header */
1352                 frame = skb_push(skb, TTP_HEADER);
1353
1354                 frame[0] = n & 0x7f;
1355         }
1356
1357         ret = irlmp_connect_response(self->lsap, skb);
1358
1359         return ret;
1360 }
1361
1362 /*
1363  * Function irttp_dup (self, instance)
1364  *
1365  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1366  *    new TSAP so it can keep listening on the old one.
1367  */
1368 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1369 {
1370         struct tsap_cb *new;
1371
1372         IRDA_DEBUG(1, __FUNCTION__ "()\n");
1373
1374         if (!hashbin_find(irttp->tsaps, (int) orig, NULL)) {
1375                 IRDA_DEBUG(0, __FUNCTION__ "(), unable to find TSAP\n");
1376                 return NULL;
1377         }
1378         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1379         if (!new) {
1380                 IRDA_DEBUG(0, __FUNCTION__ "(), unable to kmalloc\n");
1381                 return NULL;
1382         }
1383         /* Dup */
1384         memcpy(new, orig, sizeof(struct tsap_cb));
1385         new->notify.instance = instance;
1386         new->lsap = irlmp_dup(orig->lsap, new);
1387
1388         /* Not everything should be copied */
1389         init_timer(&new->todo_timer);
1390
1391         skb_queue_head_init(&new->rx_queue);
1392         skb_queue_head_init(&new->tx_queue);
1393         skb_queue_head_init(&new->rx_fragments);
1394
1395         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (int) new, NULL);
1396
1397         return new;
1398 }
1399
1400 /*
1401  * Function irttp_disconnect_request (self)
1402  *
1403  *    Close this connection please! If priority is high, the queued data
1404  *    segments, if any, will be deallocated first
1405  *
1406  */
1407 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1408                              int priority)
1409 {
1410         struct sk_buff *skb;
1411         int ret;
1412
1413         ASSERT(self != NULL, return -1;);
1414         ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1415
1416         /* Already disconnected? */
1417         if (!self->connected) {
1418                 IRDA_DEBUG(4, __FUNCTION__ "(), already disconnected!\n");
1419                 if (userdata)
1420                         dev_kfree_skb(userdata);
1421                 return -1;
1422         }
1423
1424         /* Disconnect already pending ?
1425          * We need to use an atomic operation to prevent reentry. This
1426          * function may be called from various context, like user, timer
1427          * for following a disconnect_indication() (i.e. net_bh).
1428          * Jean II */
1429         if(test_and_set_bit(0, &self->disconnect_pend)) {
1430                 IRDA_DEBUG(0, __FUNCTION__ "(), disconnect already pending\n");
1431                 if (userdata)
1432                         dev_kfree_skb(userdata);
1433
1434                 /* Try to make some progress */
1435                 irttp_run_tx_queue(self);
1436                 return -1;
1437         }
1438
1439         /*
1440          *  Check if there is still data segments in the transmit queue
1441          */
1442         if (skb_queue_len(&self->tx_queue) > 0) {
1443                 if (priority == P_HIGH) {
1444                         /*
1445                          *  No need to send the queued data, if we are
1446                          *  disconnecting right now since the data will
1447                          *  not have any usable connection to be sent on
1448                          */
1449                         IRDA_DEBUG(1, __FUNCTION__  "High priority!!()\n" );
1450                         irttp_flush_queues(self);
1451                 } else if (priority == P_NORMAL) {
1452                         /*
1453                          *  Must delay disconnect until after all data segments
1454                          *  have been sent and the tx_queue is empty
1455                          */
1456                         /* We'll reuse this one later for the disconnect */
1457                         self->disconnect_skb = userdata;  /* May be NULL */
1458
1459                         irttp_run_tx_queue(self);
1460
1461                         irttp_start_todo_timer(self, HZ/10);
1462                         return -1;
1463                 }
1464         }
1465         /* Note : we don't need to check if self->rx_queue is full and the
1466          * state of self->rx_sdu_busy because the disconnect response will
1467          * be sent at the LMP level (so even if the peer has its Tx queue
1468          * full of data). - Jean II */
1469
1470         IRDA_DEBUG(1, __FUNCTION__ "(), Disconnecting ...\n");
1471         self->connected = FALSE;
1472
1473         if (!userdata) {
1474                 skb = dev_alloc_skb(64);
1475                 if (!skb)
1476                         return -ENOMEM;
1477
1478                 /*
1479                  *  Reserve space for MUX and LAP header
1480                  */
1481                 skb_reserve(skb, TTP_MAX_HEADER);
1482
1483                 userdata = skb;
1484         }
1485         ret = irlmp_disconnect_request(self->lsap, userdata);
1486
1487         /* The disconnect is no longer pending */
1488         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1489
1490         return ret;
1491 }
1492
1493 /*
1494  * Function irttp_disconnect_indication (self, reason)
1495  *
1496  *    Disconnect indication, TSAP disconnected by peer?
1497  *
1498  */
1499 void irttp_disconnect_indication(void *instance, void *sap, LM_REASON reason,
1500                                  struct sk_buff *skb)
1501 {
1502         struct tsap_cb *self;
1503
1504         IRDA_DEBUG(4, __FUNCTION__ "()\n");
1505
1506         self = (struct tsap_cb *) instance;
1507
1508         ASSERT(self != NULL, return;);
1509         ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1510
1511         /* Prevent higher layer to send more data */
1512         self->connected = FALSE;
1513
1514         /* Check if client has already tried to close the TSAP */
1515         if (self->close_pend) {
1516                 /* In this case, the higher layer is probably gone. Don't
1517                  * bother it and clean up the remains - Jean II */
1518                 if (skb)
1519                         dev_kfree_skb(skb);
1520                 irttp_close_tsap(self);
1521                 return;
1522         }
1523
1524         /* If we are here, we assume that is the higher layer is still
1525          * waiting for the disconnect notification and able to process it,
1526          * even if he tried to disconnect. Otherwise, it would have already
1527          * attempted to close the tsap and self->close_pend would be TRUE.
1528          * Jean II */
1529
1530         /* No need to notify the client if has already tried to disconnect */
1531         if(self->notify.disconnect_indication)
1532                 self->notify.disconnect_indication(self->notify.instance, self,
1533                                                    reason, skb);
1534         else
1535                 if (skb)
1536                         dev_kfree_skb(skb);
1537 }
1538
1539 /*
1540  * Function irttp_do_data_indication (self, skb)
1541  *
1542  *    Try to deliver reassebled skb to layer above, and requeue it if that
1543  *    for some reason should fail. We mark rx sdu as busy to apply back
1544  *    pressure is necessary.
1545  */
1546 void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1547 {
1548         int err;
1549
1550         /* Check if client has already tried to close the TSAP */
1551         if (self->close_pend) {
1552                 dev_kfree_skb(skb);
1553                 return;
1554         }
1555
1556         err = self->notify.data_indication(self->notify.instance, self, skb);
1557
1558         /* Usually the layer above will notify that it's input queue is
1559          * starting to get filled by using the flow request, but this may
1560          * be difficult, so it can instead just refuse to eat it and just
1561          * give an error back
1562          */
1563         if (err == -ENOMEM) {
1564                 IRDA_DEBUG(0, __FUNCTION__ "() requeueing skb!\n");
1565
1566                 /* Make sure we take a break */
1567                 self->rx_sdu_busy = TRUE;
1568
1569                 /* Need to push the header in again */
1570                 skb_push(skb, TTP_HEADER);
1571                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1572
1573                 /* Put skb back on queue */
1574                 skb_queue_head(&self->rx_queue, skb);
1575         }
1576 }
1577
1578 /*
1579  * Function irttp_run_rx_queue (self)
1580  *
1581  *     Check if we have any frames to be transmitted, or if we have any
1582  *     available credit to give away.
1583  */
1584 void irttp_run_rx_queue(struct tsap_cb *self)
1585 {
1586         struct sk_buff *skb;
1587         int more = 0;
1588
1589         IRDA_DEBUG(2, __FUNCTION__ "() send=%d,avail=%d,remote=%d\n",
1590                    self->send_credit, self->avail_credit, self->remote_credit);
1591
1592         /* Get exclusive access to the rx queue, otherwise don't touch it */
1593         if (irda_lock(&self->rx_queue_lock) == FALSE)
1594                 return;
1595
1596         /*
1597          *  Reassemble all frames in receive queue and deliver them
1598          */
1599         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1600                 /* This bit will tell us if it's the last fragment or not */
1601                 more = skb->data[0] & 0x80;
1602
1603                 /* Remove TTP header */
1604                 skb_pull(skb, TTP_HEADER);
1605
1606                 /* Add the length of the remaining data */
1607                 self->rx_sdu_size += skb->len;
1608
1609                 /*
1610                  * If SAR is disabled, or user has requested no reassembly
1611                  * of received fragments then we just deliver them
1612                  * immediately. This can be requested by clients that
1613                  * implements byte streams without any message boundaries
1614                  */
1615                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1616                         irttp_do_data_indication(self, skb);
1617                         self->rx_sdu_size = 0;
1618
1619                         continue;
1620                 }
1621
1622                 /* Check if this is a fragment, and not the last fragment */
1623                 if (more) {
1624                         /*
1625                          *  Queue the fragment if we still are within the
1626                          *  limits of the maximum size of the rx_sdu
1627                          */
1628                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1629                                 IRDA_DEBUG(4, __FUNCTION__ "(), queueing frag\n");
1630                                 skb_queue_tail(&self->rx_fragments, skb);
1631                         } else {
1632                                 /* Free the part of the SDU that is too big */
1633                                 dev_kfree_skb(skb);
1634                         }
1635                         continue;
1636                 }
1637                 /*
1638                  *  This is the last fragment, so time to reassemble!
1639                  */
1640                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1641                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1642                 {
1643                         /*
1644                          * A little optimizing. Only queue the fragment if
1645                          * there are other fragments. Since if this is the
1646                          * last and only fragment, there is no need to
1647                          * reassemble :-)
1648                          */
1649                         if (!skb_queue_empty(&self->rx_fragments)) {
1650                                 skb_queue_tail(&self->rx_fragments,
1651                                                skb);
1652
1653                                 skb = irttp_reassemble_skb(self);
1654                         }
1655
1656                         /* Now we can deliver the reassembled skb */
1657                         irttp_do_data_indication(self, skb);
1658                 } else {
1659                         IRDA_DEBUG(1, __FUNCTION__ "(), Truncated frame\n");
1660
1661                         /* Free the part of the SDU that is too big */
1662                         dev_kfree_skb(skb);
1663
1664                         /* Deliver only the valid but truncated part of SDU */
1665                         skb = irttp_reassemble_skb(self);
1666
1667                         irttp_do_data_indication(self, skb);
1668                 }
1669                 self->rx_sdu_size = 0;
1670         }
1671
1672         /*
1673          * It's not trivial to keep track of how many credits are available
1674          * by incrementing at each packet, because delivery may fail
1675          * (irttp_do_data_indication() may requeue the frame) and because
1676          * we need to take care of fragmentation.
1677          * We want the other side to send up to initial_credit packets.
1678          * We have some frames in our queues, and we have already allowed it
1679          * to send remote_credit.
1680          * No need to spinlock, write is atomic and self correcting...
1681          * Jean II
1682          */
1683         self->avail_credit = (self->initial_credit -
1684                               (self->remote_credit +
1685                                skb_queue_len(&self->rx_queue) +
1686                                skb_queue_len(&self->rx_fragments)));
1687
1688         /* Do we have too much credits to send to peer ? */
1689         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1690             (self->avail_credit > 0)) {
1691                 /* Send explicit credit frame */
1692                 irttp_give_credit(self);
1693                 /* Note : do *NOT* check if tx_queue is non-empty, that
1694                  * will produce deadlocks. I repeat : send a credit frame
1695                  * even if we have something to send in our Tx queue.
1696                  * If we have credits, it means that our Tx queue is blocked.
1697                  *
1698                  * Let's suppose the peer can't keep up with our Tx. He will
1699                  * flow control us by not sending us any credits, and we
1700                  * will stop Tx and start accumulating credits here.
1701                  * Up to the point where the peer will stop its Tx queue,
1702                  * for lack of credits.
1703                  * Let's assume the peer application is single threaded.
1704                  * It will block on Tx and never consume any Rx buffer.
1705                  * Deadlock. Guaranteed. - Jean II
1706                  */
1707         }
1708
1709         /* Reset lock */
1710         self->rx_queue_lock = 0;
1711 }
1712
1713 #ifdef CONFIG_PROC_FS
1714 /*
1715  * Function irttp_proc_read (buf, start, offset, len, unused)
1716  *
1717  *    Give some info to the /proc file system
1718  */
1719 int irttp_proc_read(char *buf, char **start, off_t offset, int len)
1720 {
1721         struct tsap_cb *self;
1722         unsigned long flags;
1723         int i = 0;
1724
1725         ASSERT(irttp != NULL, return 0;);
1726
1727         len = 0;
1728
1729         save_flags(flags);
1730         cli();
1731
1732         self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1733         while (self != NULL) {
1734                 if (!self || self->magic != TTP_TSAP_MAGIC)
1735                         break;
1736
1737                 len += sprintf(buf+len, "TSAP %d, ", i++);
1738                 len += sprintf(buf+len, "stsap_sel: %02x, ",
1739                                self->stsap_sel);
1740                 len += sprintf(buf+len, "dtsap_sel: %02x\n",
1741                                self->dtsap_sel);
1742                 len += sprintf(buf+len, "  connected: %s, ",
1743                                self->connected? "TRUE":"FALSE");
1744                 len += sprintf(buf+len, "avail credit: %d, ",
1745                                self->avail_credit);
1746                 len += sprintf(buf+len, "remote credit: %d, ",
1747                                self->remote_credit);
1748                 len += sprintf(buf+len, "send credit: %d\n",
1749                                self->send_credit);
1750                 len += sprintf(buf+len, "  tx packets: %ld, ",
1751                                self->stats.tx_packets);
1752                 len += sprintf(buf+len, "rx packets: %ld, ",
1753                                self->stats.rx_packets);
1754                 len += sprintf(buf+len, "tx_queue len: %d ",
1755                                skb_queue_len(&self->tx_queue));
1756                 len += sprintf(buf+len, "rx_queue len: %d\n",
1757                                skb_queue_len(&self->rx_queue));
1758                 len += sprintf(buf+len, "  tx_sdu_busy: %s, ",
1759                                self->tx_sdu_busy? "TRUE":"FALSE");
1760                 len += sprintf(buf+len, "rx_sdu_busy: %s\n",
1761                                self->rx_sdu_busy? "TRUE":"FALSE");
1762                 len += sprintf(buf+len, "  max_seg_size: %d, ",
1763                                self->max_seg_size);
1764                 len += sprintf(buf+len, "tx_max_sdu_size: %d, ",
1765                                self->tx_max_sdu_size);
1766                 len += sprintf(buf+len, "rx_max_sdu_size: %d\n",
1767                                self->rx_max_sdu_size);
1768
1769                 len += sprintf(buf+len, "  Used by (%s)\n",
1770                                 self->notify.name);
1771
1772                 len += sprintf(buf+len, "\n");
1773
1774                 self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps);
1775         }
1776         restore_flags(flags);
1777
1778         return len;
1779 }
1780
1781 #endif /* PROC_FS */