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(64, GFP_ATOMIC);
 808         if (!tx_skb)
 809                 return;
 810
 811         /* Reserve space for LMP, and LAP header */
 812         skb_reserve(tx_skb, self->max_header_size);
 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(64, GFP_ATOMIC);
1097                 if (!tx_skb)
1098                         return -ENOMEM;
1099
1100                 /* Reserve space for MUX_CONTROL and LAP header */
1101                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1102         } else {
1103                 tx_skb = userdata;
1104                 /*
1105                  *  Check that the client has reserved enough space for
1106                  *  headers
1107                  */
1108                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1109                         { dev_kfree_skb(userdata); return -1; } );
1110         }
1111
1112         /* Initialize connection parameters */
1113         self->connected = FALSE;
1114         self->avail_credit = 0;
1115         self->rx_max_sdu_size = max_sdu_size;
1116         self->rx_sdu_size = 0;
1117         self->rx_sdu_busy = FALSE;
1118         self->dtsap_sel = dtsap_sel;
1119
1120         n = self->initial_credit;
1121
1122         self->remote_credit = 0;
1123         self->send_credit = 0;
1124
1125         /*
1126          *  Give away max 127 credits for now
1127          */
1128         if (n > 127) {
1129                 self->avail_credit=n-127;
1130                 n = 127;
1131         }
1132
1133         self->remote_credit = n;
1134
1135         /* SAR enabled? */
1136         if (max_sdu_size > 0) {
1137                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1138                         { dev_kfree_skb(tx_skb); return -1; } );
1139
1140                 /* Insert SAR parameters */
1141                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1142
1143                 frame[0] = TTP_PARAMETERS | n;
1144                 frame[1] = 0x04; /* Length */
1145                 frame[2] = 0x01; /* MaxSduSize */
1146                 frame[3] = 0x02; /* Value length */
1147
1148                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1149                               (__u16 *)(frame+4));
1150         } else {
1151                 /* Insert plain TTP header */
1152                 frame = skb_push(tx_skb, TTP_HEADER);
1153
1154                 /* Insert initial credit in frame */
1155                 frame[0] = n & 0x7f;
1156         }
1157
1158         /* Connect with IrLMP. No QoS parameters for now */
1159         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1160                                      tx_skb);
1161 }
1162 EXPORT_SYMBOL(irttp_connect_request);
1163
1164 /*
1165  * Function irttp_connect_confirm (handle, qos, skb)
1166  *
1167  *    Sevice user confirms TSAP connection with peer.
1168  *
1169  */
1170 static void irttp_connect_confirm(void *instance, void *sap,
1171                                   struct qos_info *qos, __u32 max_seg_size,
1172                                   __u8 max_header_size, struct sk_buff *skb)
1173 {
1174         struct tsap_cb *self;
1175         int parameters;
1176         int ret;
1177         __u8 plen;
1178         __u8 n;
1179
1180         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1181
1182         self = (struct tsap_cb *) instance;
1183
1184         IRDA_ASSERT(self != NULL, return;);
1185         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1186         IRDA_ASSERT(skb != NULL, return;);
1187
1188         self->max_seg_size = max_seg_size - TTP_HEADER;
1189         self->max_header_size = max_header_size + TTP_HEADER;
1190
1191         /*
1192          *  Check if we have got some QoS parameters back! This should be the
1193          *  negotiated QoS for the link.
1194          */
1195         if (qos) {
1196                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1197                        qos->baud_rate.bits);
1198                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1199                        qos->baud_rate.value);
1200         }
1201
1202         n = skb->data[0] & 0x7f;
1203
1204         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __FUNCTION__, n);
1205
1206         self->send_credit = n;
1207         self->tx_max_sdu_size = 0;
1208         self->connected = TRUE;
1209
1210         parameters = skb->data[0] & 0x80;
1211
1212         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1213         skb_pull(skb, TTP_HEADER);
1214
1215         if (parameters) {
1216                 plen = skb->data[0];
1217
1218                 ret = irda_param_extract_all(self, skb->data+1,
1219                                              IRDA_MIN(skb->len-1, plen),
1220                                              &param_info);
1221
1222                 /* Any errors in the parameter list? */
1223                 if (ret < 0) {
1224                         IRDA_WARNING("%s: error extracting parameters\n",
1225                                      __FUNCTION__);
1226                         dev_kfree_skb(skb);
1227
1228                         /* Do not accept this connection attempt */
1229                         return;
1230                 }
1231                 /* Remove parameters */
1232                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1233         }
1234
1235         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1236               self->send_credit, self->avail_credit, self->remote_credit);
1237
1238         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __FUNCTION__,
1239                    self->tx_max_sdu_size);
1240
1241         if (self->notify.connect_confirm) {
1242                 self->notify.connect_confirm(self->notify.instance, self, qos,
1243                                              self->tx_max_sdu_size,
1244                                              self->max_header_size, skb);
1245         } else
1246                 dev_kfree_skb(skb);
1247 }
1248
1249 /*
1250  * Function irttp_connect_indication (handle, skb)
1251  *
1252  *    Some other device is connecting to this TSAP
1253  *
1254  */
1255 void irttp_connect_indication(void *instance, void *sap, struct qos_info *qos,
1256                               __u32 max_seg_size, __u8 max_header_size,
1257                               struct sk_buff *skb)
1258 {
1259         struct tsap_cb *self;
1260         struct lsap_cb *lsap;
1261         int parameters;
1262         int ret;
1263         __u8 plen;
1264         __u8 n;
1265
1266         self = (struct tsap_cb *) instance;
1267
1268         IRDA_ASSERT(self != NULL, return;);
1269         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1270         IRDA_ASSERT(skb != NULL, return;);
1271
1272         lsap = (struct lsap_cb *) sap;
1273
1274         self->max_seg_size = max_seg_size - TTP_HEADER;
1275         self->max_header_size = max_header_size+TTP_HEADER;
1276
1277         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __FUNCTION__, self->stsap_sel);
1278
1279         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1280         self->dtsap_sel = lsap->dlsap_sel;
1281
1282         n = skb->data[0] & 0x7f;
1283
1284         self->send_credit = n;
1285         self->tx_max_sdu_size = 0;
1286
1287         parameters = skb->data[0] & 0x80;
1288
1289         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1290         skb_pull(skb, TTP_HEADER);
1291
1292         if (parameters) {
1293                 plen = skb->data[0];
1294
1295                 ret = irda_param_extract_all(self, skb->data+1,
1296                                              IRDA_MIN(skb->len-1, plen),
1297                                              &param_info);
1298
1299                 /* Any errors in the parameter list? */
1300                 if (ret < 0) {
1301                         IRDA_WARNING("%s: error extracting parameters\n",
1302                                      __FUNCTION__);
1303                         dev_kfree_skb(skb);
1304
1305                         /* Do not accept this connection attempt */
1306                         return;
1307                 }
1308
1309                 /* Remove parameters */
1310                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1311         }
1312
1313         if (self->notify.connect_indication) {
1314                 self->notify.connect_indication(self->notify.instance, self,
1315                                                 qos, self->tx_max_sdu_size,
1316                                                 self->max_header_size, skb);
1317         } else
1318                 dev_kfree_skb(skb);
1319 }
1320
1321 /*
1322  * Function irttp_connect_response (handle, userdata)
1323  *
1324  *    Service user is accepting the connection, just pass it down to
1325  *    IrLMP!
1326  *
1327  */
1328 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1329                            struct sk_buff *userdata)
1330 {
1331         struct sk_buff *tx_skb;
1332         __u8 *frame;
1333         int ret;
1334         __u8 n;
1335
1336         IRDA_ASSERT(self != NULL, return -1;);
1337         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1338
1339         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __FUNCTION__,
1340                    self->stsap_sel);
1341
1342         /* Any userdata supplied? */
1343         if (userdata == NULL) {
1344                 tx_skb = alloc_skb(64, GFP_ATOMIC);
1345                 if (!tx_skb)
1346                         return -ENOMEM;
1347
1348                 /* Reserve space for MUX_CONTROL and LAP header */
1349                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1350         } else {
1351                 tx_skb = userdata;
1352                 /*
1353                  *  Check that the client has reserved enough space for
1354                  *  headers
1355                  */
1356                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1357                         { dev_kfree_skb(userdata); return -1; } );
1358         }
1359
1360         self->avail_credit = 0;
1361         self->remote_credit = 0;
1362         self->rx_max_sdu_size = max_sdu_size;
1363         self->rx_sdu_size = 0;
1364         self->rx_sdu_busy = FALSE;
1365
1366         n = self->initial_credit;
1367
1368         /* Frame has only space for max 127 credits (7 bits) */
1369         if (n > 127) {
1370                 self->avail_credit = n - 127;
1371                 n = 127;
1372         }
1373
1374         self->remote_credit = n;
1375         self->connected = TRUE;
1376
1377         /* SAR enabled? */
1378         if (max_sdu_size > 0) {
1379                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1380                         { dev_kfree_skb(tx_skb); return -1; } );
1381
1382                 /* Insert TTP header with SAR parameters */
1383                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1384
1385                 frame[0] = TTP_PARAMETERS | n;
1386                 frame[1] = 0x04; /* Length */
1387
1388                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1389 /*                                TTP_SAR_HEADER, &param_info) */
1390
1391                 frame[2] = 0x01; /* MaxSduSize */
1392                 frame[3] = 0x02; /* Value length */
1393
1394                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1395                               (__u16 *)(frame+4));
1396         } else {
1397                 /* Insert TTP header */
1398                 frame = skb_push(tx_skb, TTP_HEADER);
1399
1400                 frame[0] = n & 0x7f;
1401         }
1402
1403         ret = irlmp_connect_response(self->lsap, tx_skb);
1404
1405         return ret;
1406 }
1407 EXPORT_SYMBOL(irttp_connect_response);
1408
1409 /*
1410  * Function irttp_dup (self, instance)
1411  *
1412  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1413  *    new TSAP so it can keep listening on the old one.
1414  */
1415 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1416 {
1417         struct tsap_cb *new;
1418         unsigned long flags;
1419
1420         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1421
1422         /* Protect our access to the old tsap instance */
1423         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1424
1425         /* Find the old instance */
1426         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1427                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __FUNCTION__);
1428                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1429                 return NULL;
1430         }
1431
1432         /* Allocate a new instance */
1433         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1434         if (!new) {
1435                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __FUNCTION__);
1436                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1437                 return NULL;
1438         }
1439         /* Dup */
1440         memcpy(new, orig, sizeof(struct tsap_cb));
1441
1442         /* We don't need the old instance any more */
1443         spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1444
1445         /* Try to dup the LSAP (may fail if we were too slow) */
1446         new->lsap = irlmp_dup(orig->lsap, new);
1447         if (!new->lsap) {
1448                 IRDA_DEBUG(0, "%s(), dup failed!\n", __FUNCTION__);
1449                 kfree(new);
1450                 return NULL;
1451         }
1452
1453         /* Not everything should be copied */
1454         new->notify.instance = instance;
1455         init_timer(&new->todo_timer);
1456
1457         skb_queue_head_init(&new->rx_queue);
1458         skb_queue_head_init(&new->tx_queue);
1459         skb_queue_head_init(&new->rx_fragments);
1460
1461         /* This is locked */
1462         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1463
1464         return new;
1465 }
1466 EXPORT_SYMBOL(irttp_dup);
1467
1468 /*
1469  * Function irttp_disconnect_request (self)
1470  *
1471  *    Close this connection please! If priority is high, the queued data
1472  *    segments, if any, will be deallocated first
1473  *
1474  */
1475 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1476                              int priority)
1477 {
1478         int ret;
1479
1480         IRDA_ASSERT(self != NULL, return -1;);
1481         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1482
1483         /* Already disconnected? */
1484         if (!self->connected) {
1485                 IRDA_DEBUG(4, "%s(), already disconnected!\n", __FUNCTION__);
1486                 if (userdata)
1487                         dev_kfree_skb(userdata);
1488                 return -1;
1489         }
1490
1491         /* Disconnect already pending ?
1492          * We need to use an atomic operation to prevent reentry. This
1493          * function may be called from various context, like user, timer
1494          * for following a disconnect_indication() (i.e. net_bh).
1495          * Jean II */
1496         if(test_and_set_bit(0, &self->disconnect_pend)) {
1497                 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1498                            __FUNCTION__);
1499                 if (userdata)
1500                         dev_kfree_skb(userdata);
1501
1502                 /* Try to make some progress */
1503                 irttp_run_tx_queue(self);
1504                 return -1;
1505         }
1506
1507         /*
1508          *  Check if there is still data segments in the transmit queue
1509          */
1510         if (!skb_queue_empty(&self->tx_queue)) {
1511                 if (priority == P_HIGH) {
1512                         /*
1513                          *  No need to send the queued data, if we are
1514                          *  disconnecting right now since the data will
1515                          *  not have any usable connection to be sent on
1516                          */
1517                         IRDA_DEBUG(1, "%s(): High priority!!()\n", __FUNCTION__);
1518                         irttp_flush_queues(self);
1519                 } else if (priority == P_NORMAL) {
1520                         /*
1521                          *  Must delay disconnect until after all data segments
1522                          *  have been sent and the tx_queue is empty
1523                          */
1524                         /* We'll reuse this one later for the disconnect */
1525                         self->disconnect_skb = userdata;  /* May be NULL */
1526
1527                         irttp_run_tx_queue(self);
1528
1529                         irttp_start_todo_timer(self, HZ/10);
1530                         return -1;
1531                 }
1532         }
1533         /* Note : we don't need to check if self->rx_queue is full and the
1534          * state of self->rx_sdu_busy because the disconnect response will
1535          * be sent at the LMP level (so even if the peer has its Tx queue
1536          * full of data). - Jean II */
1537
1538         IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __FUNCTION__);
1539         self->connected = FALSE;
1540
1541         if (!userdata) {
1542                 struct sk_buff *tx_skb;
1543                 tx_skb = alloc_skb(64, GFP_ATOMIC);
1544                 if (!tx_skb)
1545                         return -ENOMEM;
1546
1547                 /*
1548                  *  Reserve space for MUX and LAP header
1549                  */
1550                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1551
1552                 userdata = tx_skb;
1553         }
1554         ret = irlmp_disconnect_request(self->lsap, userdata);
1555
1556         /* The disconnect is no longer pending */
1557         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1558
1559         return ret;
1560 }
1561 EXPORT_SYMBOL(irttp_disconnect_request);
1562
1563 /*
1564  * Function irttp_disconnect_indication (self, reason)
1565  *
1566  *    Disconnect indication, TSAP disconnected by peer?
1567  *
1568  */
1569 void irttp_disconnect_indication(void *instance, void *sap, LM_REASON reason,
1570                                  struct sk_buff *skb)
1571 {
1572         struct tsap_cb *self;
1573
1574         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1575
1576         self = (struct tsap_cb *) instance;
1577
1578         IRDA_ASSERT(self != NULL, return;);
1579         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1580
1581         /* Prevent higher layer to send more data */
1582         self->connected = FALSE;
1583
1584         /* Check if client has already tried to close the TSAP */
1585         if (self->close_pend) {
1586                 /* In this case, the higher layer is probably gone. Don't
1587                  * bother it and clean up the remains - Jean II */
1588                 if (skb)
1589                         dev_kfree_skb(skb);
1590                 irttp_close_tsap(self);
1591                 return;
1592         }
1593
1594         /* If we are here, we assume that is the higher layer is still
1595          * waiting for the disconnect notification and able to process it,
1596          * even if he tried to disconnect. Otherwise, it would have already
1597          * attempted to close the tsap and self->close_pend would be TRUE.
1598          * Jean II */
1599
1600         /* No need to notify the client if has already tried to disconnect */
1601         if(self->notify.disconnect_indication)
1602                 self->notify.disconnect_indication(self->notify.instance, self,
1603                                                    reason, skb);
1604         else
1605                 if (skb)
1606                         dev_kfree_skb(skb);
1607 }
1608
1609 /*
1610  * Function irttp_do_data_indication (self, skb)
1611  *
1612  *    Try to deliver reassembled skb to layer above, and requeue it if that
1613  *    for some reason should fail. We mark rx sdu as busy to apply back
1614  *    pressure is necessary.
1615  */
1616 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1617 {
1618         int err;
1619
1620         /* Check if client has already closed the TSAP and gone away */
1621         if (self->close_pend) {
1622                 dev_kfree_skb(skb);
1623                 return;
1624         }
1625
1626         err = self->notify.data_indication(self->notify.instance, self, skb);
1627
1628         /* Usually the layer above will notify that it's input queue is
1629          * starting to get filled by using the flow request, but this may
1630          * be difficult, so it can instead just refuse to eat it and just
1631          * give an error back
1632          */
1633         if (err) {
1634                 IRDA_DEBUG(0, "%s() requeueing skb!\n", __FUNCTION__);
1635
1636                 /* Make sure we take a break */
1637                 self->rx_sdu_busy = TRUE;
1638
1639                 /* Need to push the header in again */
1640                 skb_push(skb, TTP_HEADER);
1641                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1642
1643                 /* Put skb back on queue */
1644                 skb_queue_head(&self->rx_queue, skb);
1645         }
1646 }
1647
1648 /*
1649  * Function irttp_run_rx_queue (self)
1650  *
1651  *     Check if we have any frames to be transmitted, or if we have any
1652  *     available credit to give away.
1653  */
1654 void irttp_run_rx_queue(struct tsap_cb *self)
1655 {
1656         struct sk_buff *skb;
1657         int more = 0;
1658
1659         IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1660                    self->send_credit, self->avail_credit, self->remote_credit);
1661
1662         /* Get exclusive access to the rx queue, otherwise don't touch it */
1663         if (irda_lock(&self->rx_queue_lock) == FALSE)
1664                 return;
1665
1666         /*
1667          *  Reassemble all frames in receive queue and deliver them
1668          */
1669         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1670                 /* This bit will tell us if it's the last fragment or not */
1671                 more = skb->data[0] & 0x80;
1672
1673                 /* Remove TTP header */
1674                 skb_pull(skb, TTP_HEADER);
1675
1676                 /* Add the length of the remaining data */
1677                 self->rx_sdu_size += skb->len;
1678
1679                 /*
1680                  * If SAR is disabled, or user has requested no reassembly
1681                  * of received fragments then we just deliver them
1682                  * immediately. This can be requested by clients that
1683                  * implements byte streams without any message boundaries
1684                  */
1685                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1686                         irttp_do_data_indication(self, skb);
1687                         self->rx_sdu_size = 0;
1688
1689                         continue;
1690                 }
1691
1692                 /* Check if this is a fragment, and not the last fragment */
1693                 if (more) {
1694                         /*
1695                          *  Queue the fragment if we still are within the
1696                          *  limits of the maximum size of the rx_sdu
1697                          */
1698                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1699                                 IRDA_DEBUG(4, "%s(), queueing frag\n",
1700                                            __FUNCTION__);
1701                                 skb_queue_tail(&self->rx_fragments, skb);
1702                         } else {
1703                                 /* Free the part of the SDU that is too big */
1704                                 dev_kfree_skb(skb);
1705                         }
1706                         continue;
1707                 }
1708                 /*
1709                  *  This is the last fragment, so time to reassemble!
1710                  */
1711                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1712                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1713                 {
1714                         /*
1715                          * A little optimizing. Only queue the fragment if
1716                          * there are other fragments. Since if this is the
1717                          * last and only fragment, there is no need to
1718                          * reassemble :-)
1719                          */
1720                         if (!skb_queue_empty(&self->rx_fragments)) {
1721                                 skb_queue_tail(&self->rx_fragments,
1722                                                skb);
1723
1724                                 skb = irttp_reassemble_skb(self);
1725                         }
1726
1727                         /* Now we can deliver the reassembled skb */
1728                         irttp_do_data_indication(self, skb);
1729                 } else {
1730                         IRDA_DEBUG(1, "%s(), Truncated frame\n", __FUNCTION__);
1731
1732                         /* Free the part of the SDU that is too big */
1733                         dev_kfree_skb(skb);
1734
1735                         /* Deliver only the valid but truncated part of SDU */
1736                         skb = irttp_reassemble_skb(self);
1737
1738                         irttp_do_data_indication(self, skb);
1739                 }
1740                 self->rx_sdu_size = 0;
1741         }
1742
1743         /*
1744          * It's not trivial to keep track of how many credits are available
1745          * by incrementing at each packet, because delivery may fail
1746          * (irttp_do_data_indication() may requeue the frame) and because
1747          * we need to take care of fragmentation.
1748          * We want the other side to send up to initial_credit packets.
1749          * We have some frames in our queues, and we have already allowed it
1750          * to send remote_credit.
1751          * No need to spinlock, write is atomic and self correcting...
1752          * Jean II
1753          */
1754         self->avail_credit = (self->initial_credit -
1755                               (self->remote_credit +
1756                                skb_queue_len(&self->rx_queue) +
1757                                skb_queue_len(&self->rx_fragments)));
1758
1759         /* Do we have too much credits to send to peer ? */
1760         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1761             (self->avail_credit > 0)) {
1762                 /* Send explicit credit frame */
1763                 irttp_give_credit(self);
1764                 /* Note : do *NOT* check if tx_queue is non-empty, that
1765                  * will produce deadlocks. I repeat : send a credit frame
1766                  * even if we have something to send in our Tx queue.
1767                  * If we have credits, it means that our Tx queue is blocked.
1768                  *
1769                  * Let's suppose the peer can't keep up with our Tx. He will
1770                  * flow control us by not sending us any credits, and we
1771                  * will stop Tx and start accumulating credits here.
1772                  * Up to the point where the peer will stop its Tx queue,
1773                  * for lack of credits.
1774                  * Let's assume the peer application is single threaded.
1775                  * It will block on Tx and never consume any Rx buffer.
1776                  * Deadlock. Guaranteed. - Jean II
1777                  */
1778         }
1779
1780         /* Reset lock */
1781         self->rx_queue_lock = 0;
1782 }
1783
1784 #ifdef CONFIG_PROC_FS
1785 struct irttp_iter_state {
1786         int id;
1787 };
1788
1789 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1790 {
1791         struct irttp_iter_state *iter = seq->private;
1792         struct tsap_cb *self;
1793
1794         /* Protect our access to the tsap list */
1795         spin_lock_irq(&irttp->tsaps->hb_spinlock);
1796         iter->id = 0;
1797
1798         for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1799              self != NULL;
1800              self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1801                 if (iter->id == *pos)
1802                         break;
1803                 ++iter->id;
1804         }
1805
1806         return self;
1807 }
1808
1809 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1810 {
1811         struct irttp_iter_state *iter = seq->private;
1812
1813         ++*pos;
1814         ++iter->id;
1815         return (void *) hashbin_get_next(irttp->tsaps);
1816 }
1817
1818 static void irttp_seq_stop(struct seq_file *seq, void *v)
1819 {
1820         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1821 }
1822
1823 static int irttp_seq_show(struct seq_file *seq, void *v)
1824 {
1825         const struct irttp_iter_state *iter = seq->private;
1826         const struct tsap_cb *self = v;
1827
1828         seq_printf(seq, "TSAP %d, ", iter->id);
1829         seq_printf(seq, "stsap_sel: %02x, ",
1830                    self->stsap_sel);
1831         seq_printf(seq, "dtsap_sel: %02x\n",
1832                    self->dtsap_sel);
1833         seq_printf(seq, "  connected: %s, ",
1834                    self->connected? "TRUE":"FALSE");
1835         seq_printf(seq, "avail credit: %d, ",
1836                    self->avail_credit);
1837         seq_printf(seq, "remote credit: %d, ",
1838                    self->remote_credit);
1839         seq_printf(seq, "send credit: %d\n",
1840                    self->send_credit);
1841         seq_printf(seq, "  tx packets: %ld, ",
1842                    self->stats.tx_packets);
1843         seq_printf(seq, "rx packets: %ld, ",
1844                    self->stats.rx_packets);
1845         seq_printf(seq, "tx_queue len: %d ",
1846                    skb_queue_len(&self->tx_queue));
1847         seq_printf(seq, "rx_queue len: %d\n",
1848                    skb_queue_len(&self->rx_queue));
1849         seq_printf(seq, "  tx_sdu_busy: %s, ",
1850                    self->tx_sdu_busy? "TRUE":"FALSE");
1851         seq_printf(seq, "rx_sdu_busy: %s\n",
1852                    self->rx_sdu_busy? "TRUE":"FALSE");
1853         seq_printf(seq, "  max_seg_size: %d, ",
1854                    self->max_seg_size);
1855         seq_printf(seq, "tx_max_sdu_size: %d, ",
1856                    self->tx_max_sdu_size);
1857         seq_printf(seq, "rx_max_sdu_size: %d\n",
1858                    self->rx_max_sdu_size);
1859
1860         seq_printf(seq, "  Used by (%s)\n\n",
1861                    self->notify.name);
1862         return 0;
1863 }
1864
1865 static struct seq_operations irttp_seq_ops = {
1866         .start  = irttp_seq_start,
1867         .next   = irttp_seq_next,
1868         .stop   = irttp_seq_stop,
1869         .show   = irttp_seq_show,
1870 };
1871
1872 static int irttp_seq_open(struct inode *inode, struct file *file)
1873 {
1874         struct seq_file *seq;
1875         int rc = -ENOMEM;
1876         struct irttp_iter_state *s;
1877
1878         s = kzalloc(sizeof(*s), GFP_KERNEL);
1879         if (!s)
1880                 goto out;
1881
1882         rc = seq_open(file, &irttp_seq_ops);
1883         if (rc)
1884                 goto out_kfree;
1885
1886         seq          = file->private_data;
1887         seq->private = s;
1888 out:
1889         return rc;
1890 out_kfree:
1891         kfree(s);
1892         goto out;
1893 }
1894
1895 struct file_operations irttp_seq_fops = {
1896         .owner          = THIS_MODULE,
1897         .open           = irttp_seq_open,
1898         .read           = seq_read,
1899         .llseek         = seq_lseek,
1900         .release        = seq_release_private,
1901 };
1902
1903 #endif /* PROC_FS */