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) 2000-2003 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/skbuff.h>
  28 #include <linux/init.h>
  29 #include <linux/seq_file.h>
  30
  31 #include <asm/byteorder.h>
  32 #include <asm/unaligned.h>
  33
  34 #include <net/irda/irda.h>
  35 #include <net/irda/irlap.h>
  36 #include <net/irda/irlmp.h>
  37 #include <net/irda/parameters.h>
  38 #include <net/irda/irttp.h>
  39
  40 static struct irttp_cb *irttp;
  41
  42 static void __irttp_close_tsap(struct tsap_cb *self);
  43
  44 static int irttp_data_indication(void *instance, void *sap,
  45                                  struct sk_buff *skb);
  46 static int irttp_udata_indication(void *instance, void *sap,
  47                                   struct sk_buff *skb);
  48 static void irttp_disconnect_indication(void *instance, void *sap,
  49                                         LM_REASON reason, struct sk_buff *);
  50 static void irttp_connect_indication(void *instance, void *sap,
  51                                      struct qos_info *qos, __u32 max_sdu_size,
  52                                      __u8 header_size, struct sk_buff *skb);
  53 static void irttp_connect_confirm(void *instance, void *sap,
  54                                   struct qos_info *qos, __u32 max_sdu_size,
  55                                   __u8 header_size, struct sk_buff *skb);
  56 static void irttp_run_tx_queue(struct tsap_cb *self);
  57 static void irttp_run_rx_queue(struct tsap_cb *self);
  58
  59 static void irttp_flush_queues(struct tsap_cb *self);
  60 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  61 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  62 static void irttp_todo_expired(unsigned long data);
  63 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  64                                     int get);
  65
  66 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
  67 static void irttp_status_indication(void *instance,
  68                                     LINK_STATUS link, LOCK_STATUS lock);
  69
  70 /* Information for parsing parameters in IrTTP */
  71 static pi_minor_info_t pi_minor_call_table[] = {
  72         { NULL, 0 },                                             /* 0x00 */
  73         { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
  74 };
  75 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  76 static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  77
  78 /************************ GLOBAL PROCEDURES ************************/
  79
  80 /*
  81  * Function irttp_init (void)
  82  *
  83  *    Initialize the IrTTP layer. Called by module initialization code
  84  *
  85  */
  86 int __init irttp_init(void)
  87 {
  88         irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  89         if (irttp == NULL)
  90                 return -ENOMEM;
  91
  92         irttp->magic = TTP_MAGIC;
  93
  94         irttp->tsaps = hashbin_new(HB_LOCK);
  95         if (!irttp->tsaps) {
  96                 IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
  97                            __FUNCTION__);
  98                 kfree(irttp);
  99                 return -ENOMEM;
 100         }
 101
 102         return 0;
 103 }
 104
 105 /*
 106  * Function irttp_cleanup (void)
 107  *
 108  *    Called by module destruction/cleanup code
 109  *
 110  */
 111 void __exit irttp_cleanup(void)
 112 {
 113         /* Check for main structure */
 114         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
 115
 116         /*
 117          *  Delete hashbin and close all TSAP instances in it
 118          */
 119         hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
 120
 121         irttp->magic = 0;
 122
 123         /* De-allocate main structure */
 124         kfree(irttp);
 125
 126         irttp = NULL;
 127 }
 128
 129 /*************************** SUBROUTINES ***************************/
 130
 131 /*
 132  * Function irttp_start_todo_timer (self, timeout)
 133  *
 134  *    Start todo timer.
 135  *
 136  * Made it more effient and unsensitive to race conditions - Jean II
 137  */
 138 static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
 139 {
 140         /* Set new value for timer */
 141         mod_timer(&self->todo_timer, jiffies + timeout);
 142 }
 143
 144 /*
 145  * Function irttp_todo_expired (data)
 146  *
 147  *    Todo timer has expired!
 148  *
 149  * One of the restriction of the timer is that it is run only on the timer
 150  * interrupt which run every 10ms. This mean that even if you set the timer
 151  * with a delay of 0, it may take up to 10ms before it's run.
 152  * So, to minimise latency and keep cache fresh, we try to avoid using
 153  * it as much as possible.
 154  * Note : we can't use tasklets, because they can't be asynchronously
 155  * killed (need user context), and we can't guarantee that here...
 156  * Jean II
 157  */
 158 static void irttp_todo_expired(unsigned long data)
 159 {
 160         struct tsap_cb *self = (struct tsap_cb *) data;
 161
 162         /* Check that we still exist */
 163         if (!self || self->magic != TTP_TSAP_MAGIC)
 164                 return;
 165
 166         IRDA_DEBUG(4, "%s(instance=%p)\n", __FUNCTION__, self);
 167
 168         /* Try to make some progress, especially on Tx side - Jean II */
 169         irttp_run_rx_queue(self);
 170         irttp_run_tx_queue(self);
 171
 172         /* Check if time for disconnect */
 173         if (test_bit(0, &self->disconnect_pend)) {
 174                 /* Check if it's possible to disconnect yet */
 175                 if (skb_queue_empty(&self->tx_queue)) {
 176                         /* Make sure disconnect is not pending anymore */
 177                         clear_bit(0, &self->disconnect_pend);   /* FALSE */
 178
 179                         /* Note : self->disconnect_skb may be NULL */
 180                         irttp_disconnect_request(self, self->disconnect_skb,
 181                                                  P_NORMAL);
 182                         self->disconnect_skb = NULL;
 183                 } else {
 184                         /* Try again later */
 185                         irttp_start_todo_timer(self, HZ/10);
 186
 187                         /* No reason to try and close now */
 188                         return;
 189                 }
 190         }
 191
 192         /* Check if it's closing time */
 193         if (self->close_pend)
 194                 /* Finish cleanup */
 195                 irttp_close_tsap(self);
 196 }
 197
 198 /*
 199  * Function irttp_flush_queues (self)
 200  *
 201  *     Flushes (removes all frames) in transitt-buffer (tx_list)
 202  */
 203 void irttp_flush_queues(struct tsap_cb *self)
 204 {
 205         struct sk_buff* skb;
 206
 207         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 208
 209         IRDA_ASSERT(self != NULL, return;);
 210         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 211
 212         /* Deallocate frames waiting to be sent */
 213         while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
 214                 dev_kfree_skb(skb);
 215
 216         /* Deallocate received frames */
 217         while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
 218                 dev_kfree_skb(skb);
 219
 220         /* Deallocate received fragments */
 221         while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
 222                 dev_kfree_skb(skb);
 223 }
 224
 225 /*
 226  * Function irttp_reassemble (self)
 227  *
 228  *    Makes a new (continuous) skb of all the fragments in the fragment
 229  *    queue
 230  *
 231  */
 232 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
 233 {
 234         struct sk_buff *skb, *frag;
 235         int n = 0;  /* Fragment index */
 236
 237         IRDA_ASSERT(self != NULL, return NULL;);
 238         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
 239
 240         IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __FUNCTION__,
 241                    self->rx_sdu_size);
 242
 243         skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
 244         if (!skb)
 245                 return NULL;
 246
 247         /*
 248          * Need to reserve space for TTP header in case this skb needs to
 249          * be requeued in case delivery failes
 250          */
 251         skb_reserve(skb, TTP_HEADER);
 252         skb_put(skb, self->rx_sdu_size);
 253
 254         /*
 255          *  Copy all fragments to a new buffer
 256          */
 257         while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
 258                 memcpy(skb->data+n, frag->data, frag->len);
 259                 n += frag->len;
 260
 261                 dev_kfree_skb(frag);
 262         }
 263
 264         IRDA_DEBUG(2,
 265                    "%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
 266                    __FUNCTION__, n, self->rx_sdu_size, self->rx_max_sdu_size);
 267         /* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
 268          * by summing the size of all fragments, so we should always
 269          * have n == self->rx_sdu_size, except in cases where we
 270          * droped the last fragment (when self->rx_sdu_size exceed
 271          * self->rx_max_sdu_size), where n < self->rx_sdu_size.
 272          * Jean II */
 273         IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
 274
 275         /* Set the new length */
 276         skb_trim(skb, n);
 277
 278         self->rx_sdu_size = 0;
 279
 280         return skb;
 281 }
 282
 283 /*
 284  * Function irttp_fragment_skb (skb)
 285  *
 286  *    Fragments a frame and queues all the fragments for transmission
 287  *
 288  */
 289 static inline void irttp_fragment_skb(struct tsap_cb *self,
 290                                       struct sk_buff *skb)
 291 {
 292         struct sk_buff *frag;
 293         __u8 *frame;
 294
 295         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 296
 297         IRDA_ASSERT(self != NULL, return;);
 298         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 299         IRDA_ASSERT(skb != NULL, return;);
 300
 301         /*
 302          *  Split frame into a number of segments
 303          */
 304         while (skb->len > self->max_seg_size) {
 305                 IRDA_DEBUG(2, "%s(), fragmenting ...\n", __FUNCTION__);
 306
 307                 /* Make new segment */
 308                 frag = alloc_skb(self->max_seg_size+self->max_header_size,
 309                                  GFP_ATOMIC);
 310                 if (!frag)
 311                         return;
 312
 313                 skb_reserve(frag, self->max_header_size);
 314
 315                 /* Copy data from the original skb into this fragment. */
 316                 memcpy(skb_put(frag, self->max_seg_size), skb->data,
 317                        self->max_seg_size);
 318
 319                 /* Insert TTP header, with the more bit set */
 320                 frame = skb_push(frag, TTP_HEADER);
 321                 frame[0] = TTP_MORE;
 322
 323                 /* Hide the copied data from the original skb */
 324                 skb_pull(skb, self->max_seg_size);
 325
 326                 /* Queue fragment */
 327                 skb_queue_tail(&self->tx_queue, frag);
 328         }
 329         /* Queue what is left of the original skb */
 330         IRDA_DEBUG(2, "%s(), queuing last segment\n", __FUNCTION__);
 331
 332         frame = skb_push(skb, TTP_HEADER);
 333         frame[0] = 0x00; /* Clear more bit */
 334
 335         /* Queue fragment */
 336         skb_queue_tail(&self->tx_queue, skb);
 337 }
 338
 339 /*
 340  * Function irttp_param_max_sdu_size (self, param)
 341  *
 342  *    Handle the MaxSduSize parameter in the connect frames, this function
 343  *    will be called both when this parameter needs to be inserted into, and
 344  *    extracted from the connect frames
 345  */
 346 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 347                                     int get)
 348 {
 349         struct tsap_cb *self;
 350
 351         self = (struct tsap_cb *) instance;
 352
 353         IRDA_ASSERT(self != NULL, return -1;);
 354         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 355
 356         if (get)
 357                 param->pv.i = self->tx_max_sdu_size;
 358         else
 359                 self->tx_max_sdu_size = param->pv.i;
 360
 361         IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __FUNCTION__, param->pv.i);
 362
 363         return 0;
 364 }
 365
 366 /*************************** CLIENT CALLS ***************************/
 367 /************************** LMP CALLBACKS **************************/
 368 /* Everything is happily mixed up. Waiting for next clean up - Jean II */
 369
 370 /*
 371  * Function irttp_open_tsap (stsap, notify)
 372  *
 373  *    Create TSAP connection endpoint,
 374  */
 375 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 376 {
 377         struct tsap_cb *self;
 378         struct lsap_cb *lsap;
 379         notify_t ttp_notify;
 380
 381         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 382
 383         /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 384          * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 385          * JeanII */
 386         if((stsap_sel != LSAP_ANY) &&
 387            ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 388                 IRDA_DEBUG(0, "%s(), invalid tsap!\n", __FUNCTION__);
 389                 return NULL;
 390         }
 391
 392         self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 393         if (self == NULL) {
 394                 IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __FUNCTION__);
 395                 return NULL;
 396         }
 397         spin_lock_init(&self->lock);
 398
 399         /* Initialise todo timer */
 400         init_timer(&self->todo_timer);
 401         self->todo_timer.data     = (unsigned long) self;
 402         self->todo_timer.function = &irttp_todo_expired;
 403
 404         /* Initialize callbacks for IrLMP to use */
 405         irda_notify_init(&ttp_notify);
 406         ttp_notify.connect_confirm = irttp_connect_confirm;
 407         ttp_notify.connect_indication = irttp_connect_indication;
 408         ttp_notify.disconnect_indication = irttp_disconnect_indication;
 409         ttp_notify.data_indication = irttp_data_indication;
 410         ttp_notify.udata_indication = irttp_udata_indication;
 411         ttp_notify.flow_indication = irttp_flow_indication;
 412         if(notify->status_indication != NULL)
 413                 ttp_notify.status_indication = irttp_status_indication;
 414         ttp_notify.instance = self;
 415         strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 416
 417         self->magic = TTP_TSAP_MAGIC;
 418         self->connected = FALSE;
 419
 420         skb_queue_head_init(&self->rx_queue);
 421         skb_queue_head_init(&self->tx_queue);
 422         skb_queue_head_init(&self->rx_fragments);
 423         /*
 424          *  Create LSAP at IrLMP layer
 425          */
 426         lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 427         if (lsap == NULL) {
 428                 IRDA_WARNING("%s: unable to allocate LSAP!!\n", __FUNCTION__);
 429                 return NULL;
 430         }
 431
 432         /*
 433          *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 434          *  will replace it with whatever source selector which is free, so
 435          *  the stsap_sel we have might not be valid anymore
 436          */
 437         self->stsap_sel = lsap->slsap_sel;
 438         IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __FUNCTION__, self->stsap_sel);
 439
 440         self->notify = *notify;
 441         self->lsap = lsap;
 442
 443         hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 444
 445         if (credit > TTP_RX_MAX_CREDIT)
 446                 self->initial_credit = TTP_RX_MAX_CREDIT;
 447         else
 448                 self->initial_credit = credit;
 449
 450         return self;
 451 }
 452 EXPORT_SYMBOL(irttp_open_tsap);
 453
 454 /*
 455  * Function irttp_close (handle)
 456  *
 457  *    Remove an instance of a TSAP. This function should only deal with the
 458  *    deallocation of the TSAP, and resetting of the TSAPs values;
 459  *
 460  */
 461 static void __irttp_close_tsap(struct tsap_cb *self)
 462 {
 463         /* First make sure we're connected. */
 464         IRDA_ASSERT(self != NULL, return;);
 465         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 466
 467         irttp_flush_queues(self);
 468
 469         del_timer(&self->todo_timer);
 470
 471         /* This one won't be cleaned up if we are disconnect_pend + close_pend
 472          * and we receive a disconnect_indication */
 473         if (self->disconnect_skb)
 474                 dev_kfree_skb(self->disconnect_skb);
 475
 476         self->connected = FALSE;
 477         self->magic = ~TTP_TSAP_MAGIC;
 478
 479         kfree(self);
 480 }
 481
 482 /*
 483  * Function irttp_close (self)
 484  *
 485  *    Remove TSAP from list of all TSAPs and then deallocate all resources
 486  *    associated with this TSAP
 487  *
 488  * Note : because we *free* the tsap structure, it is the responsibility
 489  * of the caller to make sure we are called only once and to deal with
 490  * possible race conditions. - Jean II
 491  */
 492 int irttp_close_tsap(struct tsap_cb *self)
 493 {
 494         struct tsap_cb *tsap;
 495
 496         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 497
 498         IRDA_ASSERT(self != NULL, return -1;);
 499         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 500
 501         /* Make sure tsap has been disconnected */
 502         if (self->connected) {
 503                 /* Check if disconnect is not pending */
 504                 if (!test_bit(0, &self->disconnect_pend)) {
 505                         IRDA_WARNING("%s: TSAP still connected!\n",
 506                                      __FUNCTION__);
 507                         irttp_disconnect_request(self, NULL, P_NORMAL);
 508                 }
 509                 self->close_pend = TRUE;
 510                 irttp_start_todo_timer(self, HZ/10);
 511
 512                 return 0; /* Will be back! */
 513         }
 514
 515         tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 516
 517         IRDA_ASSERT(tsap == self, return -1;);
 518
 519         /* Close corresponding LSAP */
 520         if (self->lsap) {
 521                 irlmp_close_lsap(self->lsap);
 522                 self->lsap = NULL;
 523         }
 524
 525         __irttp_close_tsap(self);
 526
 527         return 0;
 528 }
 529 EXPORT_SYMBOL(irttp_close_tsap);
 530
 531 /*
 532  * Function irttp_udata_request (self, skb)
 533  *
 534  *    Send unreliable data on this TSAP
 535  *
 536  */
 537 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 538 {
 539         IRDA_ASSERT(self != NULL, return -1;);
 540         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 541         IRDA_ASSERT(skb != NULL, return -1;);
 542
 543         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 544
 545         /* Check that nothing bad happens */
 546         if ((skb->len == 0) || (!self->connected)) {
 547                 IRDA_DEBUG(1, "%s(), No data, or not connected\n",
 548                            __FUNCTION__);
 549                 goto err;
 550         }
 551
 552         if (skb->len > self->max_seg_size) {
 553                 IRDA_DEBUG(1, "%s(), UData is to large for IrLAP!\n",
 554                            __FUNCTION__);
 555                 goto err;
 556         }
 557
 558         irlmp_udata_request(self->lsap, skb);
 559         self->stats.tx_packets++;
 560
 561         return 0;
 562
 563 err:
 564         dev_kfree_skb(skb);
 565         return -1;
 566 }
 567 EXPORT_SYMBOL(irttp_udata_request);
 568
 569
 570 /*
 571  * Function irttp_data_request (handle, skb)
 572  *
 573  *    Queue frame for transmission. If SAR is enabled, fragement the frame
 574  *    and queue the fragments for transmission
 575  */
 576 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 577 {
 578         __u8 *frame;
 579         int ret;
 580
 581         IRDA_ASSERT(self != NULL, return -1;);
 582         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 583         IRDA_ASSERT(skb != NULL, return -1;);
 584
 585         IRDA_DEBUG(2, "%s() : queue len = %d\n", __FUNCTION__,
 586                    skb_queue_len(&self->tx_queue));
 587
 588         /* Check that nothing bad happens */
 589         if ((skb->len == 0) || (!self->connected)) {
 590                 IRDA_WARNING("%s: No data, or not connected\n", __FUNCTION__);
 591                 ret = -ENOTCONN;
 592                 goto err;
 593         }
 594
 595         /*
 596          *  Check if SAR is disabled, and the frame is larger than what fits
 597          *  inside an IrLAP frame
 598          */
 599         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 600                 IRDA_ERROR("%s: SAR disabled, and data is to large for IrLAP!\n",
 601                            __FUNCTION__);
 602                 ret = -EMSGSIZE;
 603                 goto err;
 604         }
 605
 606         /*
 607          *  Check if SAR is enabled, and the frame is larger than the
 608          *  TxMaxSduSize
 609          */
 610         if ((self->tx_max_sdu_size != 0) &&
 611             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 612             (skb->len > self->tx_max_sdu_size))
 613         {
 614                 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 615                            __FUNCTION__);
 616                 ret = -EMSGSIZE;
 617                 goto err;
 618         }
 619         /*
 620          *  Check if transmit queue is full
 621          */
 622         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 623                 /*
 624                  *  Give it a chance to empty itself
 625                  */
 626                 irttp_run_tx_queue(self);
 627
 628                 /* Drop packet. This error code should trigger the caller
 629                  * to resend the data in the client code - Jean II */
 630                 ret = -ENOBUFS;
 631                 goto err;
 632         }
 633
 634         /* Queue frame, or queue frame segments */
 635         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 636                 /* Queue frame */
 637                 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 638                 frame = skb_push(skb, TTP_HEADER);
 639                 frame[0] = 0x00; /* Clear more bit */
 640
 641                 skb_queue_tail(&self->tx_queue, skb);
 642         } else {
 643                 /*
 644                  *  Fragment the frame, this function will also queue the
 645                  *  fragments, we don't care about the fact the transmit
 646                  *  queue may be overfilled by all the segments for a little
 647                  *  while
 648                  */
 649                 irttp_fragment_skb(self, skb);
 650         }
 651
 652         /* Check if we can accept more data from client */
 653         if ((!self->tx_sdu_busy) &&
 654             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 655                 /* Tx queue filling up, so stop client. */
 656                 if (self->notify.flow_indication) {
 657                         self->notify.flow_indication(self->notify.instance,
 658                                                      self, FLOW_STOP);
 659                 }
 660                 /* self->tx_sdu_busy is the state of the client.
 661                  * Update state after notifying client to avoid
 662                  * race condition with irttp_flow_indication().
 663                  * If the queue empty itself after our test but before
 664                  * we set the flag, we will fix ourselves below in
 665                  * irttp_run_tx_queue().
 666                  * Jean II */
 667                 self->tx_sdu_busy = TRUE;
 668         }
 669
 670         /* Try to make some progress */
 671         irttp_run_tx_queue(self);
 672
 673         return 0;
 674
 675 err:
 676         dev_kfree_skb(skb);
 677         return ret;
 678 }
 679 EXPORT_SYMBOL(irttp_data_request);
 680
 681 /*
 682  * Function irttp_run_tx_queue (self)
 683  *
 684  *    Transmit packets queued for transmission (if possible)
 685  *
 686  */
 687 static void irttp_run_tx_queue(struct tsap_cb *self)
 688 {
 689         struct sk_buff *skb;
 690         unsigned long flags;
 691         int n;
 692
 693         IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 694                    __FUNCTION__,
 695                    self->send_credit, skb_queue_len(&self->tx_queue));
 696
 697         /* Get exclusive access to the tx queue, otherwise don't touch it */
 698         if (irda_lock(&self->tx_queue_lock) == FALSE)
 699                 return;
 700
 701         /* Try to send out frames as long as we have credits
 702          * and as long as LAP is not full. If LAP is full, it will
 703          * poll us through irttp_flow_indication() - Jean II */
 704         while ((self->send_credit > 0) &&
 705                (!irlmp_lap_tx_queue_full(self->lsap)) &&
 706                (skb = skb_dequeue(&self->tx_queue)))
 707         {
 708                 /*
 709                  *  Since we can transmit and receive frames concurrently,
 710                  *  the code below is a critical region and we must assure that
 711                  *  nobody messes with the credits while we update them.
 712                  */
 713                 spin_lock_irqsave(&self->lock, flags);
 714
 715                 n = self->avail_credit;
 716                 self->avail_credit = 0;
 717
 718                 /* Only room for 127 credits in frame */
 719                 if (n > 127) {
 720                         self->avail_credit = n-127;
 721                         n = 127;
 722                 }
 723                 self->remote_credit += n;
 724                 self->send_credit--;
 725
 726                 spin_unlock_irqrestore(&self->lock, flags);
 727
 728                 /*
 729                  *  More bit must be set by the data_request() or fragment()
 730                  *  functions
 731                  */
 732                 skb->data[0] |= (n & 0x7f);
 733
 734                 /* Detach from socket.
 735                  * The current skb has a reference to the socket that sent
 736                  * it (skb->sk). When we pass it to IrLMP, the skb will be
 737                  * stored in in IrLAP (self->wx_list). When we are within
 738                  * IrLAP, we lose the notion of socket, so we should not
 739                  * have a reference to a socket. So, we drop it here.
 740                  *
 741                  * Why does it matter ?
 742                  * When the skb is freed (kfree_skb), if it is associated
 743                  * with a socket, it release buffer space on the socket
 744                  * (through sock_wfree() and sock_def_write_space()).
 745                  * If the socket no longer exist, we may crash. Hard.
 746                  * When we close a socket, we make sure that associated packets
 747                  * in IrTTP are freed. However, we have no way to cancel
 748                  * the packet that we have passed to IrLAP. So, if a packet
 749                  * remains in IrLAP (retry on the link or else) after we
 750                  * close the socket, we are dead !
 751                  * Jean II */
 752                 if (skb->sk != NULL) {
 753                         /* IrSOCK application, IrOBEX, ... */
 754                         skb_orphan(skb);
 755                 }
 756                         /* IrCOMM over IrTTP, IrLAN, ... */
 757
 758                 /* Pass the skb to IrLMP - done */
 759                 irlmp_data_request(self->lsap, skb);
 760                 self->stats.tx_packets++;
 761         }
 762
 763         /* Check if we can accept more frames from client.
 764          * We don't want to wait until the todo timer to do that, and we
 765          * can't use tasklets (grr...), so we are obliged to give control
 766          * to client. That's ok, this test will be true not too often
 767          * (max once per LAP window) and we are called from places
 768          * where we can spend a bit of time doing stuff. - Jean II */
 769         if ((self->tx_sdu_busy) &&
 770             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 771             (!self->close_pend))
 772         {
 773                 if (self->notify.flow_indication)
 774                         self->notify.flow_indication(self->notify.instance,
 775                                                      self, FLOW_START);
 776
 777                 /* self->tx_sdu_busy is the state of the client.
 778                  * We don't really have a race here, but it's always safer
 779                  * to update our state after the client - Jean II */
 780                 self->tx_sdu_busy = FALSE;
 781         }
 782
 783         /* Reset lock */
 784         self->tx_queue_lock = 0;
 785 }
 786
 787 /*
 788  * Function irttp_give_credit (self)
 789  *
 790  *    Send a dataless flowdata TTP-PDU and give available credit to peer
 791  *    TSAP
 792  */
 793 static inline void irttp_give_credit(struct tsap_cb *self)
 794 {
 795         struct sk_buff *tx_skb = NULL;
 796         unsigned long flags;
 797         int n;
 798
 799         IRDA_ASSERT(self != NULL, return;);
 800         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 801
 802         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 803                    __FUNCTION__,
 804                    self->send_credit, self->avail_credit, self->remote_credit);
 805
 806         /* Give credit to peer */
 807         tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
 808         if (!tx_skb)
 809                 return;
 810
 811         /* Reserve space for LMP, and LAP header */
 812         skb_reserve(tx_skb, LMP_MAX_HEADER);
 813
 814         /*
 815          *  Since we can transmit and receive frames concurrently,
 816          *  the code below is a critical region and we must assure that
 817          *  nobody messes with the credits while we update them.
 818          */
 819         spin_lock_irqsave(&self->lock, flags);
 820
 821         n = self->avail_credit;
 822         self->avail_credit = 0;
 823
 824         /* Only space for 127 credits in frame */
 825         if (n > 127) {
 826                 self->avail_credit = n - 127;
 827                 n = 127;
 828         }
 829         self->remote_credit += n;
 830
 831         spin_unlock_irqrestore(&self->lock, flags);
 832
 833         skb_put(tx_skb, 1);
 834         tx_skb->data[0] = (__u8) (n & 0x7f);
 835
 836         irlmp_data_request(self->lsap, tx_skb);
 837         self->stats.tx_packets++;
 838 }
 839
 840 /*
 841  * Function irttp_udata_indication (instance, sap, skb)
 842  *
 843  *    Received some unit-data (unreliable)
 844  *
 845  */
 846 static int irttp_udata_indication(void *instance, void *sap,
 847                                   struct sk_buff *skb)
 848 {
 849         struct tsap_cb *self;
 850         int err;
 851
 852         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 853
 854         self = (struct tsap_cb *) instance;
 855
 856         IRDA_ASSERT(self != NULL, return -1;);
 857         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 858         IRDA_ASSERT(skb != NULL, return -1;);
 859
 860         self->stats.rx_packets++;
 861
 862         /* Just pass data to layer above */
 863         if (self->notify.udata_indication) {
 864                 err = self->notify.udata_indication(self->notify.instance,
 865                                                     self,skb);
 866                 /* Same comment as in irttp_do_data_indication() */
 867                 if (!err)
 868                         return 0;
 869         }
 870         /* Either no handler, or handler returns an error */
 871         dev_kfree_skb(skb);
 872
 873         return 0;
 874 }
 875
 876 /*
 877  * Function irttp_data_indication (instance, sap, skb)
 878  *
 879  *    Receive segment from IrLMP.
 880  *
 881  */
 882 static int irttp_data_indication(void *instance, void *sap,
 883                                  struct sk_buff *skb)
 884 {
 885         struct tsap_cb *self;
 886         unsigned long flags;
 887         int n;
 888
 889         self = (struct tsap_cb *) instance;
 890
 891         n = skb->data[0] & 0x7f;     /* Extract the credits */
 892
 893         self->stats.rx_packets++;
 894
 895         /*  Deal with inbound credit
 896          *  Since we can transmit and receive frames concurrently,
 897          *  the code below is a critical region and we must assure that
 898          *  nobody messes with the credits while we update them.
 899          */
 900         spin_lock_irqsave(&self->lock, flags);
 901         self->send_credit += n;
 902         if (skb->len > 1)
 903                 self->remote_credit--;
 904         spin_unlock_irqrestore(&self->lock, flags);
 905
 906         /*
 907          *  Data or dataless packet? Dataless frames contains only the
 908          *  TTP_HEADER.
 909          */
 910         if (skb->len > 1) {
 911                 /*
 912                  *  We don't remove the TTP header, since we must preserve the
 913                  *  more bit, so the defragment routing knows what to do
 914                  */
 915                 skb_queue_tail(&self->rx_queue, skb);
 916         } else {
 917                 /* Dataless flowdata TTP-PDU */
 918                 dev_kfree_skb(skb);
 919         }
 920
 921
 922         /* Push data to the higher layer.
 923          * We do it synchronously because running the todo timer for each
 924          * receive packet would be too much overhead and latency.
 925          * By passing control to the higher layer, we run the risk that
 926          * it may take time or grab a lock. Most often, the higher layer
 927          * will only put packet in a queue.
 928          * Anyway, packets are only dripping through the IrDA, so we can
 929          * have time before the next packet.
 930          * Further, we are run from NET_BH, so the worse that can happen is
 931          * us missing the optimal time to send back the PF bit in LAP.
 932          * Jean II */
 933         irttp_run_rx_queue(self);
 934
 935         /* We now give credits to peer in irttp_run_rx_queue().
 936          * We need to send credit *NOW*, otherwise we are going
 937          * to miss the next Tx window. The todo timer may take
 938          * a while before it's run... - Jean II */
 939
 940         /*
 941          * If the peer device has given us some credits and we didn't have
 942          * anyone from before, then we need to shedule the tx queue.
 943          * We need to do that because our Tx have stopped (so we may not
 944          * get any LAP flow indication) and the user may be stopped as
 945          * well. - Jean II
 946          */
 947         if (self->send_credit == n) {
 948                 /* Restart pushing stuff to LAP */
 949                 irttp_run_tx_queue(self);
 950                 /* Note : we don't want to schedule the todo timer
 951                  * because it has horrible latency. No tasklets
 952                  * because the tasklet API is broken. - Jean II */
 953         }
 954
 955         return 0;
 956 }
 957
 958 /*
 959  * Function irttp_status_indication (self, reason)
 960  *
 961  *    Status_indication, just pass to the higher layer...
 962  *
 963  */
 964 static void irttp_status_indication(void *instance,
 965                                     LINK_STATUS link, LOCK_STATUS lock)
 966 {
 967         struct tsap_cb *self;
 968
 969         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 970
 971         self = (struct tsap_cb *) instance;
 972
 973         IRDA_ASSERT(self != NULL, return;);
 974         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 975
 976         /* Check if client has already closed the TSAP and gone away */
 977         if (self->close_pend)
 978                 return;
 979
 980         /*
 981          *  Inform service user if he has requested it
 982          */
 983         if (self->notify.status_indication != NULL)
 984                 self->notify.status_indication(self->notify.instance,
 985                                                link, lock);
 986         else
 987                 IRDA_DEBUG(2, "%s(), no handler\n", __FUNCTION__);
 988 }
 989
 990 /*
 991  * Function irttp_flow_indication (self, reason)
 992  *
 993  *    Flow_indication : IrLAP tells us to send more data.
 994  *
 995  */
 996 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
 997 {
 998         struct tsap_cb *self;
 999
1000         self = (struct tsap_cb *) instance;
1001
1002         IRDA_ASSERT(self != NULL, return;);
1003         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1004
1005         IRDA_DEBUG(4, "%s(instance=%p)\n", __FUNCTION__, self);
1006
1007         /* We are "polled" directly from LAP, and the LAP want to fill
1008          * its Tx window. We want to do our best to send it data, so that
1009          * we maximise the window. On the other hand, we want to limit the
1010          * amount of work here so that LAP doesn't hang forever waiting
1011          * for packets. - Jean II */
1012
1013         /* Try to send some packets. Currently, LAP calls us every time
1014          * there is one free slot, so we will send only one packet.
1015          * This allow the scheduler to do its round robin - Jean II */
1016         irttp_run_tx_queue(self);
1017
1018         /* Note regarding the interraction with higher layer.
1019          * irttp_run_tx_queue() may call the client when its queue
1020          * start to empty, via notify.flow_indication(). Initially.
1021          * I wanted this to happen in a tasklet, to avoid client
1022          * grabbing the CPU, but we can't use tasklets safely. And timer
1023          * is definitely too slow.
1024          * This will happen only once per LAP window, and usually at
1025          * the third packet (unless window is smaller). LAP is still
1026          * doing mtt and sending first packet so it's sort of OK
1027          * to do that. Jean II */
1028
1029         /* If we need to send disconnect. try to do it now */
1030         if(self->disconnect_pend)
1031                 irttp_start_todo_timer(self, 0);
1032 }
1033
1034 /*
1035  * Function irttp_flow_request (self, command)
1036  *
1037  *    This function could be used by the upper layers to tell IrTTP to stop
1038  *    delivering frames if the receive queues are starting to get full, or
1039  *    to tell IrTTP to start delivering frames again.
1040  */
1041 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1042 {
1043         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1044
1045         IRDA_ASSERT(self != NULL, return;);
1046         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1047
1048         switch (flow) {
1049         case FLOW_STOP:
1050                 IRDA_DEBUG(1, "%s(), flow stop\n", __FUNCTION__);
1051                 self->rx_sdu_busy = TRUE;
1052                 break;
1053         case FLOW_START:
1054                 IRDA_DEBUG(1, "%s(), flow start\n", __FUNCTION__);
1055                 self->rx_sdu_busy = FALSE;
1056
1057                 /* Client say he can accept more data, try to free our
1058                  * queues ASAP - Jean II */
1059                 irttp_run_rx_queue(self);
1060
1061                 break;
1062         default:
1063                 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __FUNCTION__);
1064         }
1065 }
1066 EXPORT_SYMBOL(irttp_flow_request);
1067
1068 /*
1069  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1070  *
1071  *    Try to connect to remote destination TSAP selector
1072  *
1073  */
1074 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1075                           __u32 saddr, __u32 daddr,
1076                           struct qos_info *qos, __u32 max_sdu_size,
1077                           struct sk_buff *userdata)
1078 {
1079         struct sk_buff *tx_skb;
1080         __u8 *frame;
1081         __u8 n;
1082
1083         IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __FUNCTION__, max_sdu_size);
1084
1085         IRDA_ASSERT(self != NULL, return -EBADR;);
1086         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1087
1088         if (self->connected) {
1089                 if(userdata)
1090                         dev_kfree_skb(userdata);
1091                 return -EISCONN;
1092         }
1093
1094         /* Any userdata supplied? */
1095         if (userdata == NULL) {
1096                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1097                                    GFP_ATOMIC);
1098                 if (!tx_skb)
1099                         return -ENOMEM;
1100
1101                 /* Reserve space for MUX_CONTROL and LAP header */
1102                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1103         } else {
1104                 tx_skb = userdata;
1105                 /*
1106                  *  Check that the client has reserved enough space for
1107                  *  headers
1108                  */
1109                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1110                         { dev_kfree_skb(userdata); return -1; } );
1111         }
1112
1113         /* Initialize connection parameters */
1114         self->connected = FALSE;
1115         self->avail_credit = 0;
1116         self->rx_max_sdu_size = max_sdu_size;
1117         self->rx_sdu_size = 0;
1118         self->rx_sdu_busy = FALSE;
1119         self->dtsap_sel = dtsap_sel;
1120
1121         n = self->initial_credit;
1122
1123         self->remote_credit = 0;
1124         self->send_credit = 0;
1125
1126         /*
1127          *  Give away max 127 credits for now
1128          */
1129         if (n > 127) {
1130                 self->avail_credit=n-127;
1131                 n = 127;
1132         }
1133
1134         self->remote_credit = n;
1135
1136         /* SAR enabled? */
1137         if (max_sdu_size > 0) {
1138                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1139                         { dev_kfree_skb(tx_skb); return -1; } );
1140
1141                 /* Insert SAR parameters */
1142                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1143
1144                 frame[0] = TTP_PARAMETERS | n;
1145                 frame[1] = 0x04; /* Length */
1146                 frame[2] = 0x01; /* MaxSduSize */
1147                 frame[3] = 0x02; /* Value length */
1148
1149                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1150                               (__u16 *)(frame+4));
1151         } else {
1152                 /* Insert plain TTP header */
1153                 frame = skb_push(tx_skb, TTP_HEADER);
1154
1155                 /* Insert initial credit in frame */
1156                 frame[0] = n & 0x7f;
1157         }
1158
1159         /* Connect with IrLMP. No QoS parameters for now */
1160         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1161                                      tx_skb);
1162 }
1163 EXPORT_SYMBOL(irttp_connect_request);
1164
1165 /*
1166  * Function irttp_connect_confirm (handle, qos, skb)
1167  *
1168  *    Sevice user confirms TSAP connection with peer.
1169  *
1170  */
1171 static void irttp_connect_confirm(void *instance, void *sap,
1172                                   struct qos_info *qos, __u32 max_seg_size,
1173                                   __u8 max_header_size, struct sk_buff *skb)
1174 {
1175         struct tsap_cb *self;
1176         int parameters;
1177         int ret;
1178         __u8 plen;
1179         __u8 n;
1180
1181         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1182
1183         self = (struct tsap_cb *) instance;
1184
1185         IRDA_ASSERT(self != NULL, return;);
1186         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1187         IRDA_ASSERT(skb != NULL, return;);
1188
1189         self->max_seg_size = max_seg_size - TTP_HEADER;
1190         self->max_header_size = max_header_size + TTP_HEADER;
1191
1192         /*
1193          *  Check if we have got some QoS parameters back! This should be the
1194          *  negotiated QoS for the link.
1195          */
1196         if (qos) {
1197                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1198                        qos->baud_rate.bits);
1199                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1200                        qos->baud_rate.value);
1201         }
1202
1203         n = skb->data[0] & 0x7f;
1204
1205         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __FUNCTION__, n);
1206
1207         self->send_credit = n;
1208         self->tx_max_sdu_size = 0;
1209         self->connected = TRUE;
1210
1211         parameters = skb->data[0] & 0x80;
1212
1213         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1214         skb_pull(skb, TTP_HEADER);
1215
1216         if (parameters) {
1217                 plen = skb->data[0];
1218
1219                 ret = irda_param_extract_all(self, skb->data+1,
1220                                              IRDA_MIN(skb->len-1, plen),
1221                                              &param_info);
1222
1223                 /* Any errors in the parameter list? */
1224                 if (ret < 0) {
1225                         IRDA_WARNING("%s: error extracting parameters\n",
1226                                      __FUNCTION__);
1227                         dev_kfree_skb(skb);
1228
1229                         /* Do not accept this connection attempt */
1230                         return;
1231                 }
1232                 /* Remove parameters */
1233                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1234         }
1235
1236         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1237               self->send_credit, self->avail_credit, self->remote_credit);
1238
1239         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __FUNCTION__,
1240                    self->tx_max_sdu_size);
1241
1242         if (self->notify.connect_confirm) {
1243                 self->notify.connect_confirm(self->notify.instance, self, qos,
1244                                              self->tx_max_sdu_size,
1245                                              self->max_header_size, skb);
1246         } else
1247                 dev_kfree_skb(skb);
1248 }
1249
1250 /*
1251  * Function irttp_connect_indication (handle, skb)
1252  *
1253  *    Some other device is connecting to this TSAP
1254  *
1255  */
1256 void irttp_connect_indication(void *instance, void *sap, struct qos_info *qos,
1257                               __u32 max_seg_size, __u8 max_header_size,
1258                               struct sk_buff *skb)
1259 {
1260         struct tsap_cb *self;
1261         struct lsap_cb *lsap;
1262         int parameters;
1263         int ret;
1264         __u8 plen;
1265         __u8 n;
1266
1267         self = (struct tsap_cb *) instance;
1268
1269         IRDA_ASSERT(self != NULL, return;);
1270         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1271         IRDA_ASSERT(skb != NULL, return;);
1272
1273         lsap = (struct lsap_cb *) sap;
1274
1275         self->max_seg_size = max_seg_size - TTP_HEADER;
1276         self->max_header_size = max_header_size+TTP_HEADER;
1277
1278         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __FUNCTION__, self->stsap_sel);
1279
1280         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1281         self->dtsap_sel = lsap->dlsap_sel;
1282
1283         n = skb->data[0] & 0x7f;
1284
1285         self->send_credit = n;
1286         self->tx_max_sdu_size = 0;
1287
1288         parameters = skb->data[0] & 0x80;
1289
1290         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1291         skb_pull(skb, TTP_HEADER);
1292
1293         if (parameters) {
1294                 plen = skb->data[0];
1295
1296                 ret = irda_param_extract_all(self, skb->data+1,
1297                                              IRDA_MIN(skb->len-1, plen),
1298                                              &param_info);
1299
1300                 /* Any errors in the parameter list? */
1301                 if (ret < 0) {
1302                         IRDA_WARNING("%s: error extracting parameters\n",
1303                                      __FUNCTION__);
1304                         dev_kfree_skb(skb);
1305
1306                         /* Do not accept this connection attempt */
1307                         return;
1308                 }
1309
1310                 /* Remove parameters */
1311                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1312         }
1313
1314         if (self->notify.connect_indication) {
1315                 self->notify.connect_indication(self->notify.instance, self,
1316                                                 qos, self->tx_max_sdu_size,
1317                                                 self->max_header_size, skb);
1318         } else
1319                 dev_kfree_skb(skb);
1320 }
1321
1322 /*
1323  * Function irttp_connect_response (handle, userdata)
1324  *
1325  *    Service user is accepting the connection, just pass it down to
1326  *    IrLMP!
1327  *
1328  */
1329 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1330                            struct sk_buff *userdata)
1331 {
1332         struct sk_buff *tx_skb;
1333         __u8 *frame;
1334         int ret;
1335         __u8 n;
1336
1337         IRDA_ASSERT(self != NULL, return -1;);
1338         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1339
1340         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __FUNCTION__,
1341                    self->stsap_sel);
1342
1343         /* Any userdata supplied? */
1344         if (userdata == NULL) {
1345                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1346                                    GFP_ATOMIC);
1347                 if (!tx_skb)
1348                         return -ENOMEM;
1349
1350                 /* Reserve space for MUX_CONTROL and LAP header */
1351                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1352         } else {
1353                 tx_skb = userdata;
1354                 /*
1355                  *  Check that the client has reserved enough space for
1356                  *  headers
1357                  */
1358                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1359                         { dev_kfree_skb(userdata); return -1; } );
1360         }
1361
1362         self->avail_credit = 0;
1363         self->remote_credit = 0;
1364         self->rx_max_sdu_size = max_sdu_size;
1365         self->rx_sdu_size = 0;
1366         self->rx_sdu_busy = FALSE;
1367
1368         n = self->initial_credit;
1369
1370         /* Frame has only space for max 127 credits (7 bits) */
1371         if (n > 127) {
1372                 self->avail_credit = n - 127;
1373                 n = 127;
1374         }
1375
1376         self->remote_credit = n;
1377         self->connected = TRUE;
1378
1379         /* SAR enabled? */
1380         if (max_sdu_size > 0) {
1381                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1382                         { dev_kfree_skb(tx_skb); return -1; } );
1383
1384                 /* Insert TTP header with SAR parameters */
1385                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1386
1387                 frame[0] = TTP_PARAMETERS | n;
1388                 frame[1] = 0x04; /* Length */
1389
1390                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1391 /*                                TTP_SAR_HEADER, &param_info) */
1392
1393                 frame[2] = 0x01; /* MaxSduSize */
1394                 frame[3] = 0x02; /* Value length */
1395
1396                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1397                               (__u16 *)(frame+4));
1398         } else {
1399                 /* Insert TTP header */
1400                 frame = skb_push(tx_skb, TTP_HEADER);
1401
1402                 frame[0] = n & 0x7f;
1403         }
1404
1405         ret = irlmp_connect_response(self->lsap, tx_skb);
1406
1407         return ret;
1408 }
1409 EXPORT_SYMBOL(irttp_connect_response);
1410
1411 /*
1412  * Function irttp_dup (self, instance)
1413  *
1414  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1415  *    new TSAP so it can keep listening on the old one.
1416  */
1417 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1418 {
1419         struct tsap_cb *new;
1420         unsigned long flags;
1421
1422         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1423
1424         /* Protect our access to the old tsap instance */
1425         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1426
1427         /* Find the old instance */
1428         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1429                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __FUNCTION__);
1430                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1431                 return NULL;
1432         }
1433
1434         /* Allocate a new instance */
1435         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1436         if (!new) {
1437                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __FUNCTION__);
1438                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1439                 return NULL;
1440         }
1441         /* Dup */
1442         memcpy(new, orig, sizeof(struct tsap_cb));
1443
1444         /* We don't need the old instance any more */
1445         spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1446
1447         /* Try to dup the LSAP (may fail if we were too slow) */
1448         new->lsap = irlmp_dup(orig->lsap, new);
1449         if (!new->lsap) {
1450                 IRDA_DEBUG(0, "%s(), dup failed!\n", __FUNCTION__);
1451                 kfree(new);
1452                 return NULL;
1453         }
1454
1455         /* Not everything should be copied */
1456         new->notify.instance = instance;
1457         init_timer(&new->todo_timer);
1458
1459         skb_queue_head_init(&new->rx_queue);
1460         skb_queue_head_init(&new->tx_queue);
1461         skb_queue_head_init(&new->rx_fragments);
1462
1463         /* This is locked */
1464         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1465
1466         return new;
1467 }
1468 EXPORT_SYMBOL(irttp_dup);
1469
1470 /*
1471  * Function irttp_disconnect_request (self)
1472  *
1473  *    Close this connection please! If priority is high, the queued data
1474  *    segments, if any, will be deallocated first
1475  *
1476  */
1477 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1478                              int priority)
1479 {
1480         int ret;
1481
1482         IRDA_ASSERT(self != NULL, return -1;);
1483         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1484
1485         /* Already disconnected? */
1486         if (!self->connected) {
1487                 IRDA_DEBUG(4, "%s(), already disconnected!\n", __FUNCTION__);
1488                 if (userdata)
1489                         dev_kfree_skb(userdata);
1490                 return -1;
1491         }
1492
1493         /* Disconnect already pending ?
1494          * We need to use an atomic operation to prevent reentry. This
1495          * function may be called from various context, like user, timer
1496          * for following a disconnect_indication() (i.e. net_bh).
1497          * Jean II */
1498         if(test_and_set_bit(0, &self->disconnect_pend)) {
1499                 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1500                            __FUNCTION__);
1501                 if (userdata)
1502                         dev_kfree_skb(userdata);
1503
1504                 /* Try to make some progress */
1505                 irttp_run_tx_queue(self);
1506                 return -1;
1507         }
1508
1509         /*
1510          *  Check if there is still data segments in the transmit queue
1511          */
1512         if (!skb_queue_empty(&self->tx_queue)) {
1513                 if (priority == P_HIGH) {
1514                         /*
1515                          *  No need to send the queued data, if we are
1516                          *  disconnecting right now since the data will
1517                          *  not have any usable connection to be sent on
1518                          */
1519                         IRDA_DEBUG(1, "%s(): High priority!!()\n", __FUNCTION__);
1520                         irttp_flush_queues(self);
1521                 } else if (priority == P_NORMAL) {
1522                         /*
1523                          *  Must delay disconnect until after all data segments
1524                          *  have been sent and the tx_queue is empty
1525                          */
1526                         /* We'll reuse this one later for the disconnect */
1527                         self->disconnect_skb = userdata;  /* May be NULL */
1528
1529                         irttp_run_tx_queue(self);
1530
1531                         irttp_start_todo_timer(self, HZ/10);
1532                         return -1;
1533                 }
1534         }
1535         /* Note : we don't need to check if self->rx_queue is full and the
1536          * state of self->rx_sdu_busy because the disconnect response will
1537          * be sent at the LMP level (so even if the peer has its Tx queue
1538          * full of data). - Jean II */
1539
1540         IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __FUNCTION__);
1541         self->connected = FALSE;
1542
1543         if (!userdata) {
1544                 struct sk_buff *tx_skb;
1545                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1546                 if (!tx_skb)
1547                         return -ENOMEM;
1548
1549                 /*
1550                  *  Reserve space for MUX and LAP header
1551                  */
1552                 skb_reserve(tx_skb, LMP_MAX_HEADER);
1553
1554                 userdata = tx_skb;
1555         }
1556         ret = irlmp_disconnect_request(self->lsap, userdata);
1557
1558         /* The disconnect is no longer pending */
1559         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1560
1561         return ret;
1562 }
1563 EXPORT_SYMBOL(irttp_disconnect_request);
1564
1565 /*
1566  * Function irttp_disconnect_indication (self, reason)
1567  *
1568  *    Disconnect indication, TSAP disconnected by peer?
1569  *
1570  */
1571 void irttp_disconnect_indication(void *instance, void *sap, LM_REASON reason,
1572                                  struct sk_buff *skb)
1573 {
1574         struct tsap_cb *self;
1575
1576         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1577
1578         self = (struct tsap_cb *) instance;
1579
1580         IRDA_ASSERT(self != NULL, return;);
1581         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1582
1583         /* Prevent higher layer to send more data */
1584         self->connected = FALSE;
1585
1586         /* Check if client has already tried to close the TSAP */
1587         if (self->close_pend) {
1588                 /* In this case, the higher layer is probably gone. Don't
1589                  * bother it and clean up the remains - Jean II */
1590                 if (skb)
1591                         dev_kfree_skb(skb);
1592                 irttp_close_tsap(self);
1593                 return;
1594         }
1595
1596         /* If we are here, we assume that is the higher layer is still
1597          * waiting for the disconnect notification and able to process it,
1598          * even if he tried to disconnect. Otherwise, it would have already
1599          * attempted to close the tsap and self->close_pend would be TRUE.
1600          * Jean II */
1601
1602         /* No need to notify the client if has already tried to disconnect */
1603         if(self->notify.disconnect_indication)
1604                 self->notify.disconnect_indication(self->notify.instance, self,
1605                                                    reason, skb);
1606         else
1607                 if (skb)
1608                         dev_kfree_skb(skb);
1609 }
1610
1611 /*
1612  * Function irttp_do_data_indication (self, skb)
1613  *
1614  *    Try to deliver reassembled skb to layer above, and requeue it if that
1615  *    for some reason should fail. We mark rx sdu as busy to apply back
1616  *    pressure is necessary.
1617  */
1618 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1619 {
1620         int err;
1621
1622         /* Check if client has already closed the TSAP and gone away */
1623         if (self->close_pend) {
1624                 dev_kfree_skb(skb);
1625                 return;
1626         }
1627
1628         err = self->notify.data_indication(self->notify.instance, self, skb);
1629
1630         /* Usually the layer above will notify that it's input queue is
1631          * starting to get filled by using the flow request, but this may
1632          * be difficult, so it can instead just refuse to eat it and just
1633          * give an error back
1634          */
1635         if (err) {
1636                 IRDA_DEBUG(0, "%s() requeueing skb!\n", __FUNCTION__);
1637
1638                 /* Make sure we take a break */
1639                 self->rx_sdu_busy = TRUE;
1640
1641                 /* Need to push the header in again */
1642                 skb_push(skb, TTP_HEADER);
1643                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1644
1645                 /* Put skb back on queue */
1646                 skb_queue_head(&self->rx_queue, skb);
1647         }
1648 }
1649
1650 /*
1651  * Function irttp_run_rx_queue (self)
1652  *
1653  *     Check if we have any frames to be transmitted, or if we have any
1654  *     available credit to give away.
1655  */
1656 void irttp_run_rx_queue(struct tsap_cb *self)
1657 {
1658         struct sk_buff *skb;
1659         int more = 0;
1660
1661         IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1662                    self->send_credit, self->avail_credit, self->remote_credit);
1663
1664         /* Get exclusive access to the rx queue, otherwise don't touch it */
1665         if (irda_lock(&self->rx_queue_lock) == FALSE)
1666                 return;
1667
1668         /*
1669          *  Reassemble all frames in receive queue and deliver them
1670          */
1671         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1672                 /* This bit will tell us if it's the last fragment or not */
1673                 more = skb->data[0] & 0x80;
1674
1675                 /* Remove TTP header */
1676                 skb_pull(skb, TTP_HEADER);
1677
1678                 /* Add the length of the remaining data */
1679                 self->rx_sdu_size += skb->len;
1680
1681                 /*
1682                  * If SAR is disabled, or user has requested no reassembly
1683                  * of received fragments then we just deliver them
1684                  * immediately. This can be requested by clients that
1685                  * implements byte streams without any message boundaries
1686                  */
1687                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1688                         irttp_do_data_indication(self, skb);
1689                         self->rx_sdu_size = 0;
1690
1691                         continue;
1692                 }
1693
1694                 /* Check if this is a fragment, and not the last fragment */
1695                 if (more) {
1696                         /*
1697                          *  Queue the fragment if we still are within the
1698                          *  limits of the maximum size of the rx_sdu
1699                          */
1700                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1701                                 IRDA_DEBUG(4, "%s(), queueing frag\n",
1702                                            __FUNCTION__);
1703                                 skb_queue_tail(&self->rx_fragments, skb);
1704                         } else {
1705                                 /* Free the part of the SDU that is too big */
1706                                 dev_kfree_skb(skb);
1707                         }
1708                         continue;
1709                 }
1710                 /*
1711                  *  This is the last fragment, so time to reassemble!
1712                  */
1713                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1714                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1715                 {
1716                         /*
1717                          * A little optimizing. Only queue the fragment if
1718                          * there are other fragments. Since if this is the
1719                          * last and only fragment, there is no need to
1720                          * reassemble :-)
1721                          */
1722                         if (!skb_queue_empty(&self->rx_fragments)) {
1723                                 skb_queue_tail(&self->rx_fragments,
1724                                                skb);
1725
1726                                 skb = irttp_reassemble_skb(self);
1727                         }
1728
1729                         /* Now we can deliver the reassembled skb */
1730                         irttp_do_data_indication(self, skb);
1731                 } else {
1732                         IRDA_DEBUG(1, "%s(), Truncated frame\n", __FUNCTION__);
1733
1734                         /* Free the part of the SDU that is too big */
1735                         dev_kfree_skb(skb);
1736
1737                         /* Deliver only the valid but truncated part of SDU */
1738                         skb = irttp_reassemble_skb(self);
1739
1740                         irttp_do_data_indication(self, skb);
1741                 }
1742                 self->rx_sdu_size = 0;
1743         }
1744
1745         /*
1746          * It's not trivial to keep track of how many credits are available
1747          * by incrementing at each packet, because delivery may fail
1748          * (irttp_do_data_indication() may requeue the frame) and because
1749          * we need to take care of fragmentation.
1750          * We want the other side to send up to initial_credit packets.
1751          * We have some frames in our queues, and we have already allowed it
1752          * to send remote_credit.
1753          * No need to spinlock, write is atomic and self correcting...
1754          * Jean II
1755          */
1756         self->avail_credit = (self->initial_credit -
1757                               (self->remote_credit +
1758                                skb_queue_len(&self->rx_queue) +
1759                                skb_queue_len(&self->rx_fragments)));
1760
1761         /* Do we have too much credits to send to peer ? */
1762         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1763             (self->avail_credit > 0)) {
1764                 /* Send explicit credit frame */
1765                 irttp_give_credit(self);
1766                 /* Note : do *NOT* check if tx_queue is non-empty, that
1767                  * will produce deadlocks. I repeat : send a credit frame
1768                  * even if we have something to send in our Tx queue.
1769                  * If we have credits, it means that our Tx queue is blocked.
1770                  *
1771                  * Let's suppose the peer can't keep up with our Tx. He will
1772                  * flow control us by not sending us any credits, and we
1773                  * will stop Tx and start accumulating credits here.
1774                  * Up to the point where the peer will stop its Tx queue,
1775                  * for lack of credits.
1776                  * Let's assume the peer application is single threaded.
1777                  * It will block on Tx and never consume any Rx buffer.
1778                  * Deadlock. Guaranteed. - Jean II
1779                  */
1780         }
1781
1782         /* Reset lock */
1783         self->rx_queue_lock = 0;
1784 }
1785
1786 #ifdef CONFIG_PROC_FS
1787 struct irttp_iter_state {
1788         int id;
1789 };
1790
1791 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1792 {
1793         struct irttp_iter_state *iter = seq->private;
1794         struct tsap_cb *self;
1795
1796         /* Protect our access to the tsap list */
1797         spin_lock_irq(&irttp->tsaps->hb_spinlock);
1798         iter->id = 0;
1799
1800         for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1801              self != NULL;
1802              self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1803                 if (iter->id == *pos)
1804                         break;
1805                 ++iter->id;
1806         }
1807
1808         return self;
1809 }
1810
1811 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1812 {
1813         struct irttp_iter_state *iter = seq->private;
1814
1815         ++*pos;
1816         ++iter->id;
1817         return (void *) hashbin_get_next(irttp->tsaps);
1818 }
1819
1820 static void irttp_seq_stop(struct seq_file *seq, void *v)
1821 {
1822         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1823 }
1824
1825 static int irttp_seq_show(struct seq_file *seq, void *v)
1826 {
1827         const struct irttp_iter_state *iter = seq->private;
1828         const struct tsap_cb *self = v;
1829
1830         seq_printf(seq, "TSAP %d, ", iter->id);
1831         seq_printf(seq, "stsap_sel: %02x, ",
1832                    self->stsap_sel);
1833         seq_printf(seq, "dtsap_sel: %02x\n",
1834                    self->dtsap_sel);
1835         seq_printf(seq, "  connected: %s, ",
1836                    self->connected? "TRUE":"FALSE");
1837         seq_printf(seq, "avail credit: %d, ",
1838                    self->avail_credit);
1839         seq_printf(seq, "remote credit: %d, ",
1840                    self->remote_credit);
1841         seq_printf(seq, "send credit: %d\n",
1842                    self->send_credit);
1843         seq_printf(seq, "  tx packets: %ld, ",
1844                    self->stats.tx_packets);
1845         seq_printf(seq, "rx packets: %ld, ",
1846                    self->stats.rx_packets);
1847         seq_printf(seq, "tx_queue len: %d ",
1848                    skb_queue_len(&self->tx_queue));
1849         seq_printf(seq, "rx_queue len: %d\n",
1850                    skb_queue_len(&self->rx_queue));
1851         seq_printf(seq, "  tx_sdu_busy: %s, ",
1852                    self->tx_sdu_busy? "TRUE":"FALSE");
1853         seq_printf(seq, "rx_sdu_busy: %s\n",
1854                    self->rx_sdu_busy? "TRUE":"FALSE");
1855         seq_printf(seq, "  max_seg_size: %d, ",
1856                    self->max_seg_size);
1857         seq_printf(seq, "tx_max_sdu_size: %d, ",
1858                    self->tx_max_sdu_size);
1859         seq_printf(seq, "rx_max_sdu_size: %d\n",
1860                    self->rx_max_sdu_size);
1861
1862         seq_printf(seq, "  Used by (%s)\n\n",
1863                    self->notify.name);
1864         return 0;
1865 }
1866
1867 static struct seq_operations irttp_seq_ops = {
1868         .start  = irttp_seq_start,
1869         .next   = irttp_seq_next,
1870         .stop   = irttp_seq_stop,
1871         .show   = irttp_seq_show,
1872 };
1873
1874 static int irttp_seq_open(struct inode *inode, struct file *file)
1875 {
1876         struct seq_file *seq;
1877         int rc = -ENOMEM;
1878         struct irttp_iter_state *s;
1879
1880         s = kzalloc(sizeof(*s), GFP_KERNEL);
1881         if (!s)
1882                 goto out;
1883
1884         rc = seq_open(file, &irttp_seq_ops);
1885         if (rc)
1886                 goto out_kfree;
1887
1888         seq          = file->private_data;
1889         seq->private = s;
1890 out:
1891         return rc;
1892 out_kfree:
1893         kfree(s);
1894         goto out;
1895 }
1896
1897 struct file_operations irttp_seq_fops = {
1898         .owner          = THIS_MODULE,
1899         .open           = irttp_seq_open,
1900         .read           = seq_read,
1901         .llseek         = seq_lseek,
1902         .release        = seq_release_private,
1903 };
1904
1905 #endif /* PROC_FS */