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/fs.h>
  30 #include <linux/seq_file.h>
  31
  32 #include <asm/byteorder.h>
  33 #include <asm/unaligned.h>
  34
  35 #include <net/irda/irda.h>
  36 #include <net/irda/irlap.h>
  37 #include <net/irda/irlmp.h>
  38 #include <net/irda/parameters.h>
  39 #include <net/irda/irttp.h>
  40
  41 static struct irttp_cb *irttp;
  42
  43 static void __irttp_close_tsap(struct tsap_cb *self);
  44
  45 static int irttp_data_indication(void *instance, void *sap,
  46                                  struct sk_buff *skb);
  47 static int irttp_udata_indication(void *instance, void *sap,
  48                                   struct sk_buff *skb);
  49 static void irttp_disconnect_indication(void *instance, void *sap,
  50                                         LM_REASON reason, struct sk_buff *);
  51 static void irttp_connect_indication(void *instance, void *sap,
  52                                      struct qos_info *qos, __u32 max_sdu_size,
  53                                      __u8 header_size, struct sk_buff *skb);
  54 static void irttp_connect_confirm(void *instance, void *sap,
  55                                   struct qos_info *qos, __u32 max_sdu_size,
  56                                   __u8 header_size, struct sk_buff *skb);
  57 static void irttp_run_tx_queue(struct tsap_cb *self);
  58 static void irttp_run_rx_queue(struct tsap_cb *self);
  59
  60 static void irttp_flush_queues(struct tsap_cb *self);
  61 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  62 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  63 static void irttp_todo_expired(unsigned long data);
  64 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  65                                     int get);
  66
  67 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
  68 static void irttp_status_indication(void *instance,
  69                                     LINK_STATUS link, LOCK_STATUS lock);
  70
  71 /* Information for parsing parameters in IrTTP */
  72 static pi_minor_info_t pi_minor_call_table[] = {
  73         { NULL, 0 },                                             /* 0x00 */
  74         { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
  75 };
  76 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  77 static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  78
  79 /************************ GLOBAL PROCEDURES ************************/
  80
  81 /*
  82  * Function irttp_init (void)
  83  *
  84  *    Initialize the IrTTP layer. Called by module initialization code
  85  *
  86  */
  87 int __init irttp_init(void)
  88 {
  89         irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  90         if (irttp == NULL)
  91                 return -ENOMEM;
  92
  93         irttp->magic = TTP_MAGIC;
  94
  95         irttp->tsaps = hashbin_new(HB_LOCK);
  96         if (!irttp->tsaps) {
  97                 IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
  98                            __func__);
  99                 kfree(irttp);
 100                 return -ENOMEM;
 101         }
 102
 103         return 0;
 104 }
 105
 106 /*
 107  * Function irttp_cleanup (void)
 108  *
 109  *    Called by module destruction/cleanup code
 110  *
 111  */
 112 void irttp_cleanup(void)
 113 {
 114         /* Check for main structure */
 115         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
 116
 117         /*
 118          *  Delete hashbin and close all TSAP instances in it
 119          */
 120         hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
 121
 122         irttp->magic = 0;
 123
 124         /* De-allocate main structure */
 125         kfree(irttp);
 126
 127         irttp = NULL;
 128 }
 129
 130 /*************************** SUBROUTINES ***************************/
 131
 132 /*
 133  * Function irttp_start_todo_timer (self, timeout)
 134  *
 135  *    Start todo timer.
 136  *
 137  * Made it more effient and unsensitive to race conditions - Jean II
 138  */
 139 static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
 140 {
 141         /* Set new value for timer */
 142         mod_timer(&self->todo_timer, jiffies + timeout);
 143 }
 144
 145 /*
 146  * Function irttp_todo_expired (data)
 147  *
 148  *    Todo timer has expired!
 149  *
 150  * One of the restriction of the timer is that it is run only on the timer
 151  * interrupt which run every 10ms. This mean that even if you set the timer
 152  * with a delay of 0, it may take up to 10ms before it's run.
 153  * So, to minimise latency and keep cache fresh, we try to avoid using
 154  * it as much as possible.
 155  * Note : we can't use tasklets, because they can't be asynchronously
 156  * killed (need user context), and we can't guarantee that here...
 157  * Jean II
 158  */
 159 static void irttp_todo_expired(unsigned long data)
 160 {
 161         struct tsap_cb *self = (struct tsap_cb *) data;
 162
 163         /* Check that we still exist */
 164         if (!self || self->magic != TTP_TSAP_MAGIC)
 165                 return;
 166
 167         IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
 168
 169         /* Try to make some progress, especially on Tx side - Jean II */
 170         irttp_run_rx_queue(self);
 171         irttp_run_tx_queue(self);
 172
 173         /* Check if time for disconnect */
 174         if (test_bit(0, &self->disconnect_pend)) {
 175                 /* Check if it's possible to disconnect yet */
 176                 if (skb_queue_empty(&self->tx_queue)) {
 177                         /* Make sure disconnect is not pending anymore */
 178                         clear_bit(0, &self->disconnect_pend);   /* FALSE */
 179
 180                         /* Note : self->disconnect_skb may be NULL */
 181                         irttp_disconnect_request(self, self->disconnect_skb,
 182                                                  P_NORMAL);
 183                         self->disconnect_skb = NULL;
 184                 } else {
 185                         /* Try again later */
 186                         irttp_start_todo_timer(self, HZ/10);
 187
 188                         /* No reason to try and close now */
 189                         return;
 190                 }
 191         }
 192
 193         /* Check if it's closing time */
 194         if (self->close_pend)
 195                 /* Finish cleanup */
 196                 irttp_close_tsap(self);
 197 }
 198
 199 /*
 200  * Function irttp_flush_queues (self)
 201  *
 202  *     Flushes (removes all frames) in transitt-buffer (tx_list)
 203  */
 204 static void irttp_flush_queues(struct tsap_cb *self)
 205 {
 206         struct sk_buff* skb;
 207
 208         IRDA_DEBUG(4, "%s()\n", __func__);
 209
 210         IRDA_ASSERT(self != NULL, return;);
 211         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 212
 213         /* Deallocate frames waiting to be sent */
 214         while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
 215                 dev_kfree_skb(skb);
 216
 217         /* Deallocate received frames */
 218         while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
 219                 dev_kfree_skb(skb);
 220
 221         /* Deallocate received fragments */
 222         while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
 223                 dev_kfree_skb(skb);
 224 }
 225
 226 /*
 227  * Function irttp_reassemble (self)
 228  *
 229  *    Makes a new (continuous) skb of all the fragments in the fragment
 230  *    queue
 231  *
 232  */
 233 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
 234 {
 235         struct sk_buff *skb, *frag;
 236         int n = 0;  /* Fragment index */
 237
 238         IRDA_ASSERT(self != NULL, return NULL;);
 239         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
 240
 241         IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __func__,
 242                    self->rx_sdu_size);
 243
 244         skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
 245         if (!skb)
 246                 return NULL;
 247
 248         /*
 249          * Need to reserve space for TTP header in case this skb needs to
 250          * be requeued in case delivery failes
 251          */
 252         skb_reserve(skb, TTP_HEADER);
 253         skb_put(skb, self->rx_sdu_size);
 254
 255         /*
 256          *  Copy all fragments to a new buffer
 257          */
 258         while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
 259                 skb_copy_to_linear_data_offset(skb, n, frag->data, frag->len);
 260                 n += frag->len;
 261
 262                 dev_kfree_skb(frag);
 263         }
 264
 265         IRDA_DEBUG(2,
 266                    "%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
 267                    __func__, n, self->rx_sdu_size, self->rx_max_sdu_size);
 268         /* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
 269          * by summing the size of all fragments, so we should always
 270          * have n == self->rx_sdu_size, except in cases where we
 271          * droped the last fragment (when self->rx_sdu_size exceed
 272          * self->rx_max_sdu_size), where n < self->rx_sdu_size.
 273          * Jean II */
 274         IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
 275
 276         /* Set the new length */
 277         skb_trim(skb, n);
 278
 279         self->rx_sdu_size = 0;
 280
 281         return skb;
 282 }
 283
 284 /*
 285  * Function irttp_fragment_skb (skb)
 286  *
 287  *    Fragments a frame and queues all the fragments for transmission
 288  *
 289  */
 290 static inline void irttp_fragment_skb(struct tsap_cb *self,
 291                                       struct sk_buff *skb)
 292 {
 293         struct sk_buff *frag;
 294         __u8 *frame;
 295
 296         IRDA_DEBUG(2, "%s()\n", __func__);
 297
 298         IRDA_ASSERT(self != NULL, return;);
 299         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 300         IRDA_ASSERT(skb != NULL, return;);
 301
 302         /*
 303          *  Split frame into a number of segments
 304          */
 305         while (skb->len > self->max_seg_size) {
 306                 IRDA_DEBUG(2, "%s(), fragmenting ...\n", __func__);
 307
 308                 /* Make new segment */
 309                 frag = alloc_skb(self->max_seg_size+self->max_header_size,
 310                                  GFP_ATOMIC);
 311                 if (!frag)
 312                         return;
 313
 314                 skb_reserve(frag, self->max_header_size);
 315
 316                 /* Copy data from the original skb into this fragment. */
 317                 skb_copy_from_linear_data(skb, skb_put(frag, self->max_seg_size),
 318                               self->max_seg_size);
 319
 320                 /* Insert TTP header, with the more bit set */
 321                 frame = skb_push(frag, TTP_HEADER);
 322                 frame[0] = TTP_MORE;
 323
 324                 /* Hide the copied data from the original skb */
 325                 skb_pull(skb, self->max_seg_size);
 326
 327                 /* Queue fragment */
 328                 skb_queue_tail(&self->tx_queue, frag);
 329         }
 330         /* Queue what is left of the original skb */
 331         IRDA_DEBUG(2, "%s(), queuing last segment\n", __func__);
 332
 333         frame = skb_push(skb, TTP_HEADER);
 334         frame[0] = 0x00; /* Clear more bit */
 335
 336         /* Queue fragment */
 337         skb_queue_tail(&self->tx_queue, skb);
 338 }
 339
 340 /*
 341  * Function irttp_param_max_sdu_size (self, param)
 342  *
 343  *    Handle the MaxSduSize parameter in the connect frames, this function
 344  *    will be called both when this parameter needs to be inserted into, and
 345  *    extracted from the connect frames
 346  */
 347 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 348                                     int get)
 349 {
 350         struct tsap_cb *self;
 351
 352         self = (struct tsap_cb *) instance;
 353
 354         IRDA_ASSERT(self != NULL, return -1;);
 355         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 356
 357         if (get)
 358                 param->pv.i = self->tx_max_sdu_size;
 359         else
 360                 self->tx_max_sdu_size = param->pv.i;
 361
 362         IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __func__, param->pv.i);
 363
 364         return 0;
 365 }
 366
 367 /*************************** CLIENT CALLS ***************************/
 368 /************************** LMP CALLBACKS **************************/
 369 /* Everything is happily mixed up. Waiting for next clean up - Jean II */
 370
 371 /*
 372  * Initialization, that has to be done on new tsap
 373  * instance allocation and on duplication
 374  */
 375 static void irttp_init_tsap(struct tsap_cb *tsap)
 376 {
 377         spin_lock_init(&tsap->lock);
 378         init_timer(&tsap->todo_timer);
 379
 380         skb_queue_head_init(&tsap->rx_queue);
 381         skb_queue_head_init(&tsap->tx_queue);
 382         skb_queue_head_init(&tsap->rx_fragments);
 383 }
 384
 385 /*
 386  * Function irttp_open_tsap (stsap, notify)
 387  *
 388  *    Create TSAP connection endpoint,
 389  */
 390 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 391 {
 392         struct tsap_cb *self;
 393         struct lsap_cb *lsap;
 394         notify_t ttp_notify;
 395
 396         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 397
 398         /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 399          * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 400          * JeanII */
 401         if((stsap_sel != LSAP_ANY) &&
 402            ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 403                 IRDA_DEBUG(0, "%s(), invalid tsap!\n", __func__);
 404                 return NULL;
 405         }
 406
 407         self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 408         if (self == NULL) {
 409                 IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __func__);
 410                 return NULL;
 411         }
 412
 413         /* Initialize internal objects */
 414         irttp_init_tsap(self);
 415
 416         /* Initialise todo timer */
 417         self->todo_timer.data     = (unsigned long) self;
 418         self->todo_timer.function = &irttp_todo_expired;
 419
 420         /* Initialize callbacks for IrLMP to use */
 421         irda_notify_init(&ttp_notify);
 422         ttp_notify.connect_confirm = irttp_connect_confirm;
 423         ttp_notify.connect_indication = irttp_connect_indication;
 424         ttp_notify.disconnect_indication = irttp_disconnect_indication;
 425         ttp_notify.data_indication = irttp_data_indication;
 426         ttp_notify.udata_indication = irttp_udata_indication;
 427         ttp_notify.flow_indication = irttp_flow_indication;
 428         if(notify->status_indication != NULL)
 429                 ttp_notify.status_indication = irttp_status_indication;
 430         ttp_notify.instance = self;
 431         strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 432
 433         self->magic = TTP_TSAP_MAGIC;
 434         self->connected = FALSE;
 435
 436         /*
 437          *  Create LSAP at IrLMP layer
 438          */
 439         lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 440         if (lsap == NULL) {
 441                 IRDA_WARNING("%s: unable to allocate LSAP!!\n", __func__);
 442                 return NULL;
 443         }
 444
 445         /*
 446          *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 447          *  will replace it with whatever source selector which is free, so
 448          *  the stsap_sel we have might not be valid anymore
 449          */
 450         self->stsap_sel = lsap->slsap_sel;
 451         IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
 452
 453         self->notify = *notify;
 454         self->lsap = lsap;
 455
 456         hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 457
 458         if (credit > TTP_RX_MAX_CREDIT)
 459                 self->initial_credit = TTP_RX_MAX_CREDIT;
 460         else
 461                 self->initial_credit = credit;
 462
 463         return self;
 464 }
 465 EXPORT_SYMBOL(irttp_open_tsap);
 466
 467 /*
 468  * Function irttp_close (handle)
 469  *
 470  *    Remove an instance of a TSAP. This function should only deal with the
 471  *    deallocation of the TSAP, and resetting of the TSAPs values;
 472  *
 473  */
 474 static void __irttp_close_tsap(struct tsap_cb *self)
 475 {
 476         /* First make sure we're connected. */
 477         IRDA_ASSERT(self != NULL, return;);
 478         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 479
 480         irttp_flush_queues(self);
 481
 482         del_timer(&self->todo_timer);
 483
 484         /* This one won't be cleaned up if we are disconnect_pend + close_pend
 485          * and we receive a disconnect_indication */
 486         if (self->disconnect_skb)
 487                 dev_kfree_skb(self->disconnect_skb);
 488
 489         self->connected = FALSE;
 490         self->magic = ~TTP_TSAP_MAGIC;
 491
 492         kfree(self);
 493 }
 494
 495 /*
 496  * Function irttp_close (self)
 497  *
 498  *    Remove TSAP from list of all TSAPs and then deallocate all resources
 499  *    associated with this TSAP
 500  *
 501  * Note : because we *free* the tsap structure, it is the responsibility
 502  * of the caller to make sure we are called only once and to deal with
 503  * possible race conditions. - Jean II
 504  */
 505 int irttp_close_tsap(struct tsap_cb *self)
 506 {
 507         struct tsap_cb *tsap;
 508
 509         IRDA_DEBUG(4, "%s()\n", __func__);
 510
 511         IRDA_ASSERT(self != NULL, return -1;);
 512         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 513
 514         /* Make sure tsap has been disconnected */
 515         if (self->connected) {
 516                 /* Check if disconnect is not pending */
 517                 if (!test_bit(0, &self->disconnect_pend)) {
 518                         IRDA_WARNING("%s: TSAP still connected!\n",
 519                                      __func__);
 520                         irttp_disconnect_request(self, NULL, P_NORMAL);
 521                 }
 522                 self->close_pend = TRUE;
 523                 irttp_start_todo_timer(self, HZ/10);
 524
 525                 return 0; /* Will be back! */
 526         }
 527
 528         tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 529
 530         IRDA_ASSERT(tsap == self, return -1;);
 531
 532         /* Close corresponding LSAP */
 533         if (self->lsap) {
 534                 irlmp_close_lsap(self->lsap);
 535                 self->lsap = NULL;
 536         }
 537
 538         __irttp_close_tsap(self);
 539
 540         return 0;
 541 }
 542 EXPORT_SYMBOL(irttp_close_tsap);
 543
 544 /*
 545  * Function irttp_udata_request (self, skb)
 546  *
 547  *    Send unreliable data on this TSAP
 548  *
 549  */
 550 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 551 {
 552         IRDA_ASSERT(self != NULL, return -1;);
 553         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 554         IRDA_ASSERT(skb != NULL, return -1;);
 555
 556         IRDA_DEBUG(4, "%s()\n", __func__);
 557
 558         /* Check that nothing bad happens */
 559         if ((skb->len == 0) || (!self->connected)) {
 560                 IRDA_DEBUG(1, "%s(), No data, or not connected\n",
 561                            __func__);
 562                 goto err;
 563         }
 564
 565         if (skb->len > self->max_seg_size) {
 566                 IRDA_DEBUG(1, "%s(), UData is too large for IrLAP!\n",
 567                            __func__);
 568                 goto err;
 569         }
 570
 571         irlmp_udata_request(self->lsap, skb);
 572         self->stats.tx_packets++;
 573
 574         return 0;
 575
 576 err:
 577         dev_kfree_skb(skb);
 578         return -1;
 579 }
 580 EXPORT_SYMBOL(irttp_udata_request);
 581
 582
 583 /*
 584  * Function irttp_data_request (handle, skb)
 585  *
 586  *    Queue frame for transmission. If SAR is enabled, fragement the frame
 587  *    and queue the fragments for transmission
 588  */
 589 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 590 {
 591         __u8 *frame;
 592         int ret;
 593
 594         IRDA_ASSERT(self != NULL, return -1;);
 595         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 596         IRDA_ASSERT(skb != NULL, return -1;);
 597
 598         IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
 599                    skb_queue_len(&self->tx_queue));
 600
 601         /* Check that nothing bad happens */
 602         if ((skb->len == 0) || (!self->connected)) {
 603                 IRDA_WARNING("%s: No data, or not connected\n", __func__);
 604                 ret = -ENOTCONN;
 605                 goto err;
 606         }
 607
 608         /*
 609          *  Check if SAR is disabled, and the frame is larger than what fits
 610          *  inside an IrLAP frame
 611          */
 612         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 613                 IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
 614                            __func__);
 615                 ret = -EMSGSIZE;
 616                 goto err;
 617         }
 618
 619         /*
 620          *  Check if SAR is enabled, and the frame is larger than the
 621          *  TxMaxSduSize
 622          */
 623         if ((self->tx_max_sdu_size != 0) &&
 624             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 625             (skb->len > self->tx_max_sdu_size))
 626         {
 627                 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 628                            __func__);
 629                 ret = -EMSGSIZE;
 630                 goto err;
 631         }
 632         /*
 633          *  Check if transmit queue is full
 634          */
 635         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 636                 /*
 637                  *  Give it a chance to empty itself
 638                  */
 639                 irttp_run_tx_queue(self);
 640
 641                 /* Drop packet. This error code should trigger the caller
 642                  * to resend the data in the client code - Jean II */
 643                 ret = -ENOBUFS;
 644                 goto err;
 645         }
 646
 647         /* Queue frame, or queue frame segments */
 648         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 649                 /* Queue frame */
 650                 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 651                 frame = skb_push(skb, TTP_HEADER);
 652                 frame[0] = 0x00; /* Clear more bit */
 653
 654                 skb_queue_tail(&self->tx_queue, skb);
 655         } else {
 656                 /*
 657                  *  Fragment the frame, this function will also queue the
 658                  *  fragments, we don't care about the fact the transmit
 659                  *  queue may be overfilled by all the segments for a little
 660                  *  while
 661                  */
 662                 irttp_fragment_skb(self, skb);
 663         }
 664
 665         /* Check if we can accept more data from client */
 666         if ((!self->tx_sdu_busy) &&
 667             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 668                 /* Tx queue filling up, so stop client. */
 669                 if (self->notify.flow_indication) {
 670                         self->notify.flow_indication(self->notify.instance,
 671                                                      self, FLOW_STOP);
 672                 }
 673                 /* self->tx_sdu_busy is the state of the client.
 674                  * Update state after notifying client to avoid
 675                  * race condition with irttp_flow_indication().
 676                  * If the queue empty itself after our test but before
 677                  * we set the flag, we will fix ourselves below in
 678                  * irttp_run_tx_queue().
 679                  * Jean II */
 680                 self->tx_sdu_busy = TRUE;
 681         }
 682
 683         /* Try to make some progress */
 684         irttp_run_tx_queue(self);
 685
 686         return 0;
 687
 688 err:
 689         dev_kfree_skb(skb);
 690         return ret;
 691 }
 692 EXPORT_SYMBOL(irttp_data_request);
 693
 694 /*
 695  * Function irttp_run_tx_queue (self)
 696  *
 697  *    Transmit packets queued for transmission (if possible)
 698  *
 699  */
 700 static void irttp_run_tx_queue(struct tsap_cb *self)
 701 {
 702         struct sk_buff *skb;
 703         unsigned long flags;
 704         int n;
 705
 706         IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 707                    __func__,
 708                    self->send_credit, skb_queue_len(&self->tx_queue));
 709
 710         /* Get exclusive access to the tx queue, otherwise don't touch it */
 711         if (irda_lock(&self->tx_queue_lock) == FALSE)
 712                 return;
 713
 714         /* Try to send out frames as long as we have credits
 715          * and as long as LAP is not full. If LAP is full, it will
 716          * poll us through irttp_flow_indication() - Jean II */
 717         while ((self->send_credit > 0) &&
 718                (!irlmp_lap_tx_queue_full(self->lsap)) &&
 719                (skb = skb_dequeue(&self->tx_queue)))
 720         {
 721                 /*
 722                  *  Since we can transmit and receive frames concurrently,
 723                  *  the code below is a critical region and we must assure that
 724                  *  nobody messes with the credits while we update them.
 725                  */
 726                 spin_lock_irqsave(&self->lock, flags);
 727
 728                 n = self->avail_credit;
 729                 self->avail_credit = 0;
 730
 731                 /* Only room for 127 credits in frame */
 732                 if (n > 127) {
 733                         self->avail_credit = n-127;
 734                         n = 127;
 735                 }
 736                 self->remote_credit += n;
 737                 self->send_credit--;
 738
 739                 spin_unlock_irqrestore(&self->lock, flags);
 740
 741                 /*
 742                  *  More bit must be set by the data_request() or fragment()
 743                  *  functions
 744                  */
 745                 skb->data[0] |= (n & 0x7f);
 746
 747                 /* Detach from socket.
 748                  * The current skb has a reference to the socket that sent
 749                  * it (skb->sk). When we pass it to IrLMP, the skb will be
 750                  * stored in in IrLAP (self->wx_list). When we are within
 751                  * IrLAP, we lose the notion of socket, so we should not
 752                  * have a reference to a socket. So, we drop it here.
 753                  *
 754                  * Why does it matter ?
 755                  * When the skb is freed (kfree_skb), if it is associated
 756                  * with a socket, it release buffer space on the socket
 757                  * (through sock_wfree() and sock_def_write_space()).
 758                  * If the socket no longer exist, we may crash. Hard.
 759                  * When we close a socket, we make sure that associated packets
 760                  * in IrTTP are freed. However, we have no way to cancel
 761                  * the packet that we have passed to IrLAP. So, if a packet
 762                  * remains in IrLAP (retry on the link or else) after we
 763                  * close the socket, we are dead !
 764                  * Jean II */
 765                 if (skb->sk != NULL) {
 766                         /* IrSOCK application, IrOBEX, ... */
 767                         skb_orphan(skb);
 768                 }
 769                         /* IrCOMM over IrTTP, IrLAN, ... */
 770
 771                 /* Pass the skb to IrLMP - done */
 772                 irlmp_data_request(self->lsap, skb);
 773                 self->stats.tx_packets++;
 774         }
 775
 776         /* Check if we can accept more frames from client.
 777          * We don't want to wait until the todo timer to do that, and we
 778          * can't use tasklets (grr...), so we are obliged to give control
 779          * to client. That's ok, this test will be true not too often
 780          * (max once per LAP window) and we are called from places
 781          * where we can spend a bit of time doing stuff. - Jean II */
 782         if ((self->tx_sdu_busy) &&
 783             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 784             (!self->close_pend))
 785         {
 786                 if (self->notify.flow_indication)
 787                         self->notify.flow_indication(self->notify.instance,
 788                                                      self, FLOW_START);
 789
 790                 /* self->tx_sdu_busy is the state of the client.
 791                  * We don't really have a race here, but it's always safer
 792                  * to update our state after the client - Jean II */
 793                 self->tx_sdu_busy = FALSE;
 794         }
 795
 796         /* Reset lock */
 797         self->tx_queue_lock = 0;
 798 }
 799
 800 /*
 801  * Function irttp_give_credit (self)
 802  *
 803  *    Send a dataless flowdata TTP-PDU and give available credit to peer
 804  *    TSAP
 805  */
 806 static inline void irttp_give_credit(struct tsap_cb *self)
 807 {
 808         struct sk_buff *tx_skb = NULL;
 809         unsigned long flags;
 810         int n;
 811
 812         IRDA_ASSERT(self != NULL, return;);
 813         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 814
 815         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 816                    __func__,
 817                    self->send_credit, self->avail_credit, self->remote_credit);
 818
 819         /* Give credit to peer */
 820         tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
 821         if (!tx_skb)
 822                 return;
 823
 824         /* Reserve space for LMP, and LAP header */
 825         skb_reserve(tx_skb, LMP_MAX_HEADER);
 826
 827         /*
 828          *  Since we can transmit and receive frames concurrently,
 829          *  the code below is a critical region and we must assure that
 830          *  nobody messes with the credits while we update them.
 831          */
 832         spin_lock_irqsave(&self->lock, flags);
 833
 834         n = self->avail_credit;
 835         self->avail_credit = 0;
 836
 837         /* Only space for 127 credits in frame */
 838         if (n > 127) {
 839                 self->avail_credit = n - 127;
 840                 n = 127;
 841         }
 842         self->remote_credit += n;
 843
 844         spin_unlock_irqrestore(&self->lock, flags);
 845
 846         skb_put(tx_skb, 1);
 847         tx_skb->data[0] = (__u8) (n & 0x7f);
 848
 849         irlmp_data_request(self->lsap, tx_skb);
 850         self->stats.tx_packets++;
 851 }
 852
 853 /*
 854  * Function irttp_udata_indication (instance, sap, skb)
 855  *
 856  *    Received some unit-data (unreliable)
 857  *
 858  */
 859 static int irttp_udata_indication(void *instance, void *sap,
 860                                   struct sk_buff *skb)
 861 {
 862         struct tsap_cb *self;
 863         int err;
 864
 865         IRDA_DEBUG(4, "%s()\n", __func__);
 866
 867         self = (struct tsap_cb *) instance;
 868
 869         IRDA_ASSERT(self != NULL, return -1;);
 870         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 871         IRDA_ASSERT(skb != NULL, return -1;);
 872
 873         self->stats.rx_packets++;
 874
 875         /* Just pass data to layer above */
 876         if (self->notify.udata_indication) {
 877                 err = self->notify.udata_indication(self->notify.instance,
 878                                                     self,skb);
 879                 /* Same comment as in irttp_do_data_indication() */
 880                 if (!err)
 881                         return 0;
 882         }
 883         /* Either no handler, or handler returns an error */
 884         dev_kfree_skb(skb);
 885
 886         return 0;
 887 }
 888
 889 /*
 890  * Function irttp_data_indication (instance, sap, skb)
 891  *
 892  *    Receive segment from IrLMP.
 893  *
 894  */
 895 static int irttp_data_indication(void *instance, void *sap,
 896                                  struct sk_buff *skb)
 897 {
 898         struct tsap_cb *self;
 899         unsigned long flags;
 900         int n;
 901
 902         self = (struct tsap_cb *) instance;
 903
 904         n = skb->data[0] & 0x7f;     /* Extract the credits */
 905
 906         self->stats.rx_packets++;
 907
 908         /*  Deal with inbound credit
 909          *  Since we can transmit and receive frames concurrently,
 910          *  the code below is a critical region and we must assure that
 911          *  nobody messes with the credits while we update them.
 912          */
 913         spin_lock_irqsave(&self->lock, flags);
 914         self->send_credit += n;
 915         if (skb->len > 1)
 916                 self->remote_credit--;
 917         spin_unlock_irqrestore(&self->lock, flags);
 918
 919         /*
 920          *  Data or dataless packet? Dataless frames contains only the
 921          *  TTP_HEADER.
 922          */
 923         if (skb->len > 1) {
 924                 /*
 925                  *  We don't remove the TTP header, since we must preserve the
 926                  *  more bit, so the defragment routing knows what to do
 927                  */
 928                 skb_queue_tail(&self->rx_queue, skb);
 929         } else {
 930                 /* Dataless flowdata TTP-PDU */
 931                 dev_kfree_skb(skb);
 932         }
 933
 934
 935         /* Push data to the higher layer.
 936          * We do it synchronously because running the todo timer for each
 937          * receive packet would be too much overhead and latency.
 938          * By passing control to the higher layer, we run the risk that
 939          * it may take time or grab a lock. Most often, the higher layer
 940          * will only put packet in a queue.
 941          * Anyway, packets are only dripping through the IrDA, so we can
 942          * have time before the next packet.
 943          * Further, we are run from NET_BH, so the worse that can happen is
 944          * us missing the optimal time to send back the PF bit in LAP.
 945          * Jean II */
 946         irttp_run_rx_queue(self);
 947
 948         /* We now give credits to peer in irttp_run_rx_queue().
 949          * We need to send credit *NOW*, otherwise we are going
 950          * to miss the next Tx window. The todo timer may take
 951          * a while before it's run... - Jean II */
 952
 953         /*
 954          * If the peer device has given us some credits and we didn't have
 955          * anyone from before, then we need to shedule the tx queue.
 956          * We need to do that because our Tx have stopped (so we may not
 957          * get any LAP flow indication) and the user may be stopped as
 958          * well. - Jean II
 959          */
 960         if (self->send_credit == n) {
 961                 /* Restart pushing stuff to LAP */
 962                 irttp_run_tx_queue(self);
 963                 /* Note : we don't want to schedule the todo timer
 964                  * because it has horrible latency. No tasklets
 965                  * because the tasklet API is broken. - Jean II */
 966         }
 967
 968         return 0;
 969 }
 970
 971 /*
 972  * Function irttp_status_indication (self, reason)
 973  *
 974  *    Status_indication, just pass to the higher layer...
 975  *
 976  */
 977 static void irttp_status_indication(void *instance,
 978                                     LINK_STATUS link, LOCK_STATUS lock)
 979 {
 980         struct tsap_cb *self;
 981
 982         IRDA_DEBUG(4, "%s()\n", __func__);
 983
 984         self = (struct tsap_cb *) instance;
 985
 986         IRDA_ASSERT(self != NULL, return;);
 987         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 988
 989         /* Check if client has already closed the TSAP and gone away */
 990         if (self->close_pend)
 991                 return;
 992
 993         /*
 994          *  Inform service user if he has requested it
 995          */
 996         if (self->notify.status_indication != NULL)
 997                 self->notify.status_indication(self->notify.instance,
 998                                                link, lock);
 999         else
1000                 IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1001 }
1002
1003 /*
1004  * Function irttp_flow_indication (self, reason)
1005  *
1006  *    Flow_indication : IrLAP tells us to send more data.
1007  *
1008  */
1009 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1010 {
1011         struct tsap_cb *self;
1012
1013         self = (struct tsap_cb *) instance;
1014
1015         IRDA_ASSERT(self != NULL, return;);
1016         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1017
1018         IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1019
1020         /* We are "polled" directly from LAP, and the LAP want to fill
1021          * its Tx window. We want to do our best to send it data, so that
1022          * we maximise the window. On the other hand, we want to limit the
1023          * amount of work here so that LAP doesn't hang forever waiting
1024          * for packets. - Jean II */
1025
1026         /* Try to send some packets. Currently, LAP calls us every time
1027          * there is one free slot, so we will send only one packet.
1028          * This allow the scheduler to do its round robin - Jean II */
1029         irttp_run_tx_queue(self);
1030
1031         /* Note regarding the interraction with higher layer.
1032          * irttp_run_tx_queue() may call the client when its queue
1033          * start to empty, via notify.flow_indication(). Initially.
1034          * I wanted this to happen in a tasklet, to avoid client
1035          * grabbing the CPU, but we can't use tasklets safely. And timer
1036          * is definitely too slow.
1037          * This will happen only once per LAP window, and usually at
1038          * the third packet (unless window is smaller). LAP is still
1039          * doing mtt and sending first packet so it's sort of OK
1040          * to do that. Jean II */
1041
1042         /* If we need to send disconnect. try to do it now */
1043         if(self->disconnect_pend)
1044                 irttp_start_todo_timer(self, 0);
1045 }
1046
1047 /*
1048  * Function irttp_flow_request (self, command)
1049  *
1050  *    This function could be used by the upper layers to tell IrTTP to stop
1051  *    delivering frames if the receive queues are starting to get full, or
1052  *    to tell IrTTP to start delivering frames again.
1053  */
1054 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1055 {
1056         IRDA_DEBUG(1, "%s()\n", __func__);
1057
1058         IRDA_ASSERT(self != NULL, return;);
1059         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1060
1061         switch (flow) {
1062         case FLOW_STOP:
1063                 IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1064                 self->rx_sdu_busy = TRUE;
1065                 break;
1066         case FLOW_START:
1067                 IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1068                 self->rx_sdu_busy = FALSE;
1069
1070                 /* Client say he can accept more data, try to free our
1071                  * queues ASAP - Jean II */
1072                 irttp_run_rx_queue(self);
1073
1074                 break;
1075         default:
1076                 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1077         }
1078 }
1079 EXPORT_SYMBOL(irttp_flow_request);
1080
1081 /*
1082  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1083  *
1084  *    Try to connect to remote destination TSAP selector
1085  *
1086  */
1087 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1088                           __u32 saddr, __u32 daddr,
1089                           struct qos_info *qos, __u32 max_sdu_size,
1090                           struct sk_buff *userdata)
1091 {
1092         struct sk_buff *tx_skb;
1093         __u8 *frame;
1094         __u8 n;
1095
1096         IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1097
1098         IRDA_ASSERT(self != NULL, return -EBADR;);
1099         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1100
1101         if (self->connected) {
1102                 if(userdata)
1103                         dev_kfree_skb(userdata);
1104                 return -EISCONN;
1105         }
1106
1107         /* Any userdata supplied? */
1108         if (userdata == NULL) {
1109                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1110                                    GFP_ATOMIC);
1111                 if (!tx_skb)
1112                         return -ENOMEM;
1113
1114                 /* Reserve space for MUX_CONTROL and LAP header */
1115                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1116         } else {
1117                 tx_skb = userdata;
1118                 /*
1119                  *  Check that the client has reserved enough space for
1120                  *  headers
1121                  */
1122                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1123                         { dev_kfree_skb(userdata); return -1; } );
1124         }
1125
1126         /* Initialize connection parameters */
1127         self->connected = FALSE;
1128         self->avail_credit = 0;
1129         self->rx_max_sdu_size = max_sdu_size;
1130         self->rx_sdu_size = 0;
1131         self->rx_sdu_busy = FALSE;
1132         self->dtsap_sel = dtsap_sel;
1133
1134         n = self->initial_credit;
1135
1136         self->remote_credit = 0;
1137         self->send_credit = 0;
1138
1139         /*
1140          *  Give away max 127 credits for now
1141          */
1142         if (n > 127) {
1143                 self->avail_credit=n-127;
1144                 n = 127;
1145         }
1146
1147         self->remote_credit = n;
1148
1149         /* SAR enabled? */
1150         if (max_sdu_size > 0) {
1151                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1152                         { dev_kfree_skb(tx_skb); return -1; } );
1153
1154                 /* Insert SAR parameters */
1155                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1156
1157                 frame[0] = TTP_PARAMETERS | n;
1158                 frame[1] = 0x04; /* Length */
1159                 frame[2] = 0x01; /* MaxSduSize */
1160                 frame[3] = 0x02; /* Value length */
1161
1162                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1163                               (__be16 *)(frame+4));
1164         } else {
1165                 /* Insert plain TTP header */
1166                 frame = skb_push(tx_skb, TTP_HEADER);
1167
1168                 /* Insert initial credit in frame */
1169                 frame[0] = n & 0x7f;
1170         }
1171
1172         /* Connect with IrLMP. No QoS parameters for now */
1173         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1174                                      tx_skb);
1175 }
1176 EXPORT_SYMBOL(irttp_connect_request);
1177
1178 /*
1179  * Function irttp_connect_confirm (handle, qos, skb)
1180  *
1181  *    Sevice user confirms TSAP connection with peer.
1182  *
1183  */
1184 static void irttp_connect_confirm(void *instance, void *sap,
1185                                   struct qos_info *qos, __u32 max_seg_size,
1186                                   __u8 max_header_size, struct sk_buff *skb)
1187 {
1188         struct tsap_cb *self;
1189         int parameters;
1190         int ret;
1191         __u8 plen;
1192         __u8 n;
1193
1194         IRDA_DEBUG(4, "%s()\n", __func__);
1195
1196         self = (struct tsap_cb *) instance;
1197
1198         IRDA_ASSERT(self != NULL, return;);
1199         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1200         IRDA_ASSERT(skb != NULL, return;);
1201
1202         self->max_seg_size = max_seg_size - TTP_HEADER;
1203         self->max_header_size = max_header_size + TTP_HEADER;
1204
1205         /*
1206          *  Check if we have got some QoS parameters back! This should be the
1207          *  negotiated QoS for the link.
1208          */
1209         if (qos) {
1210                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1211                        qos->baud_rate.bits);
1212                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1213                        qos->baud_rate.value);
1214         }
1215
1216         n = skb->data[0] & 0x7f;
1217
1218         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1219
1220         self->send_credit = n;
1221         self->tx_max_sdu_size = 0;
1222         self->connected = TRUE;
1223
1224         parameters = skb->data[0] & 0x80;
1225
1226         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1227         skb_pull(skb, TTP_HEADER);
1228
1229         if (parameters) {
1230                 plen = skb->data[0];
1231
1232                 ret = irda_param_extract_all(self, skb->data+1,
1233                                              IRDA_MIN(skb->len-1, plen),
1234                                              &param_info);
1235
1236                 /* Any errors in the parameter list? */
1237                 if (ret < 0) {
1238                         IRDA_WARNING("%s: error extracting parameters\n",
1239                                      __func__);
1240                         dev_kfree_skb(skb);
1241
1242                         /* Do not accept this connection attempt */
1243                         return;
1244                 }
1245                 /* Remove parameters */
1246                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1247         }
1248
1249         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1250               self->send_credit, self->avail_credit, self->remote_credit);
1251
1252         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1253                    self->tx_max_sdu_size);
1254
1255         if (self->notify.connect_confirm) {
1256                 self->notify.connect_confirm(self->notify.instance, self, qos,
1257                                              self->tx_max_sdu_size,
1258                                              self->max_header_size, skb);
1259         } else
1260                 dev_kfree_skb(skb);
1261 }
1262
1263 /*
1264  * Function irttp_connect_indication (handle, skb)
1265  *
1266  *    Some other device is connecting to this TSAP
1267  *
1268  */
1269 static void irttp_connect_indication(void *instance, void *sap,
1270                 struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1271                 struct sk_buff *skb)
1272 {
1273         struct tsap_cb *self;
1274         struct lsap_cb *lsap;
1275         int parameters;
1276         int ret;
1277         __u8 plen;
1278         __u8 n;
1279
1280         self = (struct tsap_cb *) instance;
1281
1282         IRDA_ASSERT(self != NULL, return;);
1283         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1284         IRDA_ASSERT(skb != NULL, return;);
1285
1286         lsap = (struct lsap_cb *) sap;
1287
1288         self->max_seg_size = max_seg_size - TTP_HEADER;
1289         self->max_header_size = max_header_size+TTP_HEADER;
1290
1291         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1292
1293         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1294         self->dtsap_sel = lsap->dlsap_sel;
1295
1296         n = skb->data[0] & 0x7f;
1297
1298         self->send_credit = n;
1299         self->tx_max_sdu_size = 0;
1300
1301         parameters = skb->data[0] & 0x80;
1302
1303         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1304         skb_pull(skb, TTP_HEADER);
1305
1306         if (parameters) {
1307                 plen = skb->data[0];
1308
1309                 ret = irda_param_extract_all(self, skb->data+1,
1310                                              IRDA_MIN(skb->len-1, plen),
1311                                              &param_info);
1312
1313                 /* Any errors in the parameter list? */
1314                 if (ret < 0) {
1315                         IRDA_WARNING("%s: error extracting parameters\n",
1316                                      __func__);
1317                         dev_kfree_skb(skb);
1318
1319                         /* Do not accept this connection attempt */
1320                         return;
1321                 }
1322
1323                 /* Remove parameters */
1324                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1325         }
1326
1327         if (self->notify.connect_indication) {
1328                 self->notify.connect_indication(self->notify.instance, self,
1329                                                 qos, self->tx_max_sdu_size,
1330                                                 self->max_header_size, skb);
1331         } else
1332                 dev_kfree_skb(skb);
1333 }
1334
1335 /*
1336  * Function irttp_connect_response (handle, userdata)
1337  *
1338  *    Service user is accepting the connection, just pass it down to
1339  *    IrLMP!
1340  *
1341  */
1342 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1343                            struct sk_buff *userdata)
1344 {
1345         struct sk_buff *tx_skb;
1346         __u8 *frame;
1347         int ret;
1348         __u8 n;
1349
1350         IRDA_ASSERT(self != NULL, return -1;);
1351         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1352
1353         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1354                    self->stsap_sel);
1355
1356         /* Any userdata supplied? */
1357         if (userdata == NULL) {
1358                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1359                                    GFP_ATOMIC);
1360                 if (!tx_skb)
1361                         return -ENOMEM;
1362
1363                 /* Reserve space for MUX_CONTROL and LAP header */
1364                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1365         } else {
1366                 tx_skb = userdata;
1367                 /*
1368                  *  Check that the client has reserved enough space for
1369                  *  headers
1370                  */
1371                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1372                         { dev_kfree_skb(userdata); return -1; } );
1373         }
1374
1375         self->avail_credit = 0;
1376         self->remote_credit = 0;
1377         self->rx_max_sdu_size = max_sdu_size;
1378         self->rx_sdu_size = 0;
1379         self->rx_sdu_busy = FALSE;
1380
1381         n = self->initial_credit;
1382
1383         /* Frame has only space for max 127 credits (7 bits) */
1384         if (n > 127) {
1385                 self->avail_credit = n - 127;
1386                 n = 127;
1387         }
1388
1389         self->remote_credit = n;
1390         self->connected = TRUE;
1391
1392         /* SAR enabled? */
1393         if (max_sdu_size > 0) {
1394                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1395                         { dev_kfree_skb(tx_skb); return -1; } );
1396
1397                 /* Insert TTP header with SAR parameters */
1398                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1399
1400                 frame[0] = TTP_PARAMETERS | n;
1401                 frame[1] = 0x04; /* Length */
1402
1403                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1404 /*                                TTP_SAR_HEADER, &param_info) */
1405
1406                 frame[2] = 0x01; /* MaxSduSize */
1407                 frame[3] = 0x02; /* Value length */
1408
1409                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1410                               (__be16 *)(frame+4));
1411         } else {
1412                 /* Insert TTP header */
1413                 frame = skb_push(tx_skb, TTP_HEADER);
1414
1415                 frame[0] = n & 0x7f;
1416         }
1417
1418         ret = irlmp_connect_response(self->lsap, tx_skb);
1419
1420         return ret;
1421 }
1422 EXPORT_SYMBOL(irttp_connect_response);
1423
1424 /*
1425  * Function irttp_dup (self, instance)
1426  *
1427  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1428  *    new TSAP so it can keep listening on the old one.
1429  */
1430 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1431 {
1432         struct tsap_cb *new;
1433         unsigned long flags;
1434
1435         IRDA_DEBUG(1, "%s()\n", __func__);
1436
1437         /* Protect our access to the old tsap instance */
1438         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1439
1440         /* Find the old instance */
1441         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1442                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1443                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1444                 return NULL;
1445         }
1446
1447         /* Allocate a new instance */
1448         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1449         if (!new) {
1450                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1451                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1452                 return NULL;
1453         }
1454         /* Dup */
1455         memcpy(new, orig, sizeof(struct tsap_cb));
1456         spin_lock_init(&new->lock);
1457
1458         /* We don't need the old instance any more */
1459         spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1460
1461         /* Try to dup the LSAP (may fail if we were too slow) */
1462         new->lsap = irlmp_dup(orig->lsap, new);
1463         if (!new->lsap) {
1464                 IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1465                 kfree(new);
1466                 return NULL;
1467         }
1468
1469         /* Not everything should be copied */
1470         new->notify.instance = instance;
1471
1472         /* Initialize internal objects */
1473         irttp_init_tsap(new);
1474
1475         /* This is locked */
1476         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1477
1478         return new;
1479 }
1480 EXPORT_SYMBOL(irttp_dup);
1481
1482 /*
1483  * Function irttp_disconnect_request (self)
1484  *
1485  *    Close this connection please! If priority is high, the queued data
1486  *    segments, if any, will be deallocated first
1487  *
1488  */
1489 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1490                              int priority)
1491 {
1492         int ret;
1493
1494         IRDA_ASSERT(self != NULL, return -1;);
1495         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1496
1497         /* Already disconnected? */
1498         if (!self->connected) {
1499                 IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1500                 if (userdata)
1501                         dev_kfree_skb(userdata);
1502                 return -1;
1503         }
1504
1505         /* Disconnect already pending ?
1506          * We need to use an atomic operation to prevent reentry. This
1507          * function may be called from various context, like user, timer
1508          * for following a disconnect_indication() (i.e. net_bh).
1509          * Jean II */
1510         if(test_and_set_bit(0, &self->disconnect_pend)) {
1511                 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1512                            __func__);
1513                 if (userdata)
1514                         dev_kfree_skb(userdata);
1515
1516                 /* Try to make some progress */
1517                 irttp_run_tx_queue(self);
1518                 return -1;
1519         }
1520
1521         /*
1522          *  Check if there is still data segments in the transmit queue
1523          */
1524         if (!skb_queue_empty(&self->tx_queue)) {
1525                 if (priority == P_HIGH) {
1526                         /*
1527                          *  No need to send the queued data, if we are
1528                          *  disconnecting right now since the data will
1529                          *  not have any usable connection to be sent on
1530                          */
1531                         IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1532                         irttp_flush_queues(self);
1533                 } else if (priority == P_NORMAL) {
1534                         /*
1535                          *  Must delay disconnect until after all data segments
1536                          *  have been sent and the tx_queue is empty
1537                          */
1538                         /* We'll reuse this one later for the disconnect */
1539                         self->disconnect_skb = userdata;  /* May be NULL */
1540
1541                         irttp_run_tx_queue(self);
1542
1543                         irttp_start_todo_timer(self, HZ/10);
1544                         return -1;
1545                 }
1546         }
1547         /* Note : we don't need to check if self->rx_queue is full and the
1548          * state of self->rx_sdu_busy because the disconnect response will
1549          * be sent at the LMP level (so even if the peer has its Tx queue
1550          * full of data). - Jean II */
1551
1552         IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1553         self->connected = FALSE;
1554
1555         if (!userdata) {
1556                 struct sk_buff *tx_skb;
1557                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1558                 if (!tx_skb)
1559                         return -ENOMEM;
1560
1561                 /*
1562                  *  Reserve space for MUX and LAP header
1563                  */
1564                 skb_reserve(tx_skb, LMP_MAX_HEADER);
1565
1566                 userdata = tx_skb;
1567         }
1568         ret = irlmp_disconnect_request(self->lsap, userdata);
1569
1570         /* The disconnect is no longer pending */
1571         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1572
1573         return ret;
1574 }
1575 EXPORT_SYMBOL(irttp_disconnect_request);
1576
1577 /*
1578  * Function irttp_disconnect_indication (self, reason)
1579  *
1580  *    Disconnect indication, TSAP disconnected by peer?
1581  *
1582  */
1583 static void irttp_disconnect_indication(void *instance, void *sap,
1584                 LM_REASON reason, struct sk_buff *skb)
1585 {
1586         struct tsap_cb *self;
1587
1588         IRDA_DEBUG(4, "%s()\n", __func__);
1589
1590         self = (struct tsap_cb *) instance;
1591
1592         IRDA_ASSERT(self != NULL, return;);
1593         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1594
1595         /* Prevent higher layer to send more data */
1596         self->connected = FALSE;
1597
1598         /* Check if client has already tried to close the TSAP */
1599         if (self->close_pend) {
1600                 /* In this case, the higher layer is probably gone. Don't
1601                  * bother it and clean up the remains - Jean II */
1602                 if (skb)
1603                         dev_kfree_skb(skb);
1604                 irttp_close_tsap(self);
1605                 return;
1606         }
1607
1608         /* If we are here, we assume that is the higher layer is still
1609          * waiting for the disconnect notification and able to process it,
1610          * even if he tried to disconnect. Otherwise, it would have already
1611          * attempted to close the tsap and self->close_pend would be TRUE.
1612          * Jean II */
1613
1614         /* No need to notify the client if has already tried to disconnect */
1615         if(self->notify.disconnect_indication)
1616                 self->notify.disconnect_indication(self->notify.instance, self,
1617                                                    reason, skb);
1618         else
1619                 if (skb)
1620                         dev_kfree_skb(skb);
1621 }
1622
1623 /*
1624  * Function irttp_do_data_indication (self, skb)
1625  *
1626  *    Try to deliver reassembled skb to layer above, and requeue it if that
1627  *    for some reason should fail. We mark rx sdu as busy to apply back
1628  *    pressure is necessary.
1629  */
1630 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1631 {
1632         int err;
1633
1634         /* Check if client has already closed the TSAP and gone away */
1635         if (self->close_pend) {
1636                 dev_kfree_skb(skb);
1637                 return;
1638         }
1639
1640         err = self->notify.data_indication(self->notify.instance, self, skb);
1641
1642         /* Usually the layer above will notify that it's input queue is
1643          * starting to get filled by using the flow request, but this may
1644          * be difficult, so it can instead just refuse to eat it and just
1645          * give an error back
1646          */
1647         if (err) {
1648                 IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1649
1650                 /* Make sure we take a break */
1651                 self->rx_sdu_busy = TRUE;
1652
1653                 /* Need to push the header in again */
1654                 skb_push(skb, TTP_HEADER);
1655                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1656
1657                 /* Put skb back on queue */
1658                 skb_queue_head(&self->rx_queue, skb);
1659         }
1660 }
1661
1662 /*
1663  * Function irttp_run_rx_queue (self)
1664  *
1665  *     Check if we have any frames to be transmitted, or if we have any
1666  *     available credit to give away.
1667  */
1668 static void irttp_run_rx_queue(struct tsap_cb *self)
1669 {
1670         struct sk_buff *skb;
1671         int more = 0;
1672
1673         IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1674                    self->send_credit, self->avail_credit, self->remote_credit);
1675
1676         /* Get exclusive access to the rx queue, otherwise don't touch it */
1677         if (irda_lock(&self->rx_queue_lock) == FALSE)
1678                 return;
1679
1680         /*
1681          *  Reassemble all frames in receive queue and deliver them
1682          */
1683         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1684                 /* This bit will tell us if it's the last fragment or not */
1685                 more = skb->data[0] & 0x80;
1686
1687                 /* Remove TTP header */
1688                 skb_pull(skb, TTP_HEADER);
1689
1690                 /* Add the length of the remaining data */
1691                 self->rx_sdu_size += skb->len;
1692
1693                 /*
1694                  * If SAR is disabled, or user has requested no reassembly
1695                  * of received fragments then we just deliver them
1696                  * immediately. This can be requested by clients that
1697                  * implements byte streams without any message boundaries
1698                  */
1699                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1700                         irttp_do_data_indication(self, skb);
1701                         self->rx_sdu_size = 0;
1702
1703                         continue;
1704                 }
1705
1706                 /* Check if this is a fragment, and not the last fragment */
1707                 if (more) {
1708                         /*
1709                          *  Queue the fragment if we still are within the
1710                          *  limits of the maximum size of the rx_sdu
1711                          */
1712                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1713                                 IRDA_DEBUG(4, "%s(), queueing frag\n",
1714                                            __func__);
1715                                 skb_queue_tail(&self->rx_fragments, skb);
1716                         } else {
1717                                 /* Free the part of the SDU that is too big */
1718                                 dev_kfree_skb(skb);
1719                         }
1720                         continue;
1721                 }
1722                 /*
1723                  *  This is the last fragment, so time to reassemble!
1724                  */
1725                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1726                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1727                 {
1728                         /*
1729                          * A little optimizing. Only queue the fragment if
1730                          * there are other fragments. Since if this is the
1731                          * last and only fragment, there is no need to
1732                          * reassemble :-)
1733                          */
1734                         if (!skb_queue_empty(&self->rx_fragments)) {
1735                                 skb_queue_tail(&self->rx_fragments,
1736                                                skb);
1737
1738                                 skb = irttp_reassemble_skb(self);
1739                         }
1740
1741                         /* Now we can deliver the reassembled skb */
1742                         irttp_do_data_indication(self, skb);
1743                 } else {
1744                         IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1745
1746                         /* Free the part of the SDU that is too big */
1747                         dev_kfree_skb(skb);
1748
1749                         /* Deliver only the valid but truncated part of SDU */
1750                         skb = irttp_reassemble_skb(self);
1751
1752                         irttp_do_data_indication(self, skb);
1753                 }
1754                 self->rx_sdu_size = 0;
1755         }
1756
1757         /*
1758          * It's not trivial to keep track of how many credits are available
1759          * by incrementing at each packet, because delivery may fail
1760          * (irttp_do_data_indication() may requeue the frame) and because
1761          * we need to take care of fragmentation.
1762          * We want the other side to send up to initial_credit packets.
1763          * We have some frames in our queues, and we have already allowed it
1764          * to send remote_credit.
1765          * No need to spinlock, write is atomic and self correcting...
1766          * Jean II
1767          */
1768         self->avail_credit = (self->initial_credit -
1769                               (self->remote_credit +
1770                                skb_queue_len(&self->rx_queue) +
1771                                skb_queue_len(&self->rx_fragments)));
1772
1773         /* Do we have too much credits to send to peer ? */
1774         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1775             (self->avail_credit > 0)) {
1776                 /* Send explicit credit frame */
1777                 irttp_give_credit(self);
1778                 /* Note : do *NOT* check if tx_queue is non-empty, that
1779                  * will produce deadlocks. I repeat : send a credit frame
1780                  * even if we have something to send in our Tx queue.
1781                  * If we have credits, it means that our Tx queue is blocked.
1782                  *
1783                  * Let's suppose the peer can't keep up with our Tx. He will
1784                  * flow control us by not sending us any credits, and we
1785                  * will stop Tx and start accumulating credits here.
1786                  * Up to the point where the peer will stop its Tx queue,
1787                  * for lack of credits.
1788                  * Let's assume the peer application is single threaded.
1789                  * It will block on Tx and never consume any Rx buffer.
1790                  * Deadlock. Guaranteed. - Jean II
1791                  */
1792         }
1793
1794         /* Reset lock */
1795         self->rx_queue_lock = 0;
1796 }
1797
1798 #ifdef CONFIG_PROC_FS
1799 struct irttp_iter_state {
1800         int id;
1801 };
1802
1803 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1804 {
1805         struct irttp_iter_state *iter = seq->private;
1806         struct tsap_cb *self;
1807
1808         /* Protect our access to the tsap list */
1809         spin_lock_irq(&irttp->tsaps->hb_spinlock);
1810         iter->id = 0;
1811
1812         for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1813              self != NULL;
1814              self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1815                 if (iter->id == *pos)
1816                         break;
1817                 ++iter->id;
1818         }
1819
1820         return self;
1821 }
1822
1823 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1824 {
1825         struct irttp_iter_state *iter = seq->private;
1826
1827         ++*pos;
1828         ++iter->id;
1829         return (void *) hashbin_get_next(irttp->tsaps);
1830 }
1831
1832 static void irttp_seq_stop(struct seq_file *seq, void *v)
1833 {
1834         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1835 }
1836
1837 static int irttp_seq_show(struct seq_file *seq, void *v)
1838 {
1839         const struct irttp_iter_state *iter = seq->private;
1840         const struct tsap_cb *self = v;
1841
1842         seq_printf(seq, "TSAP %d, ", iter->id);
1843         seq_printf(seq, "stsap_sel: %02x, ",
1844                    self->stsap_sel);
1845         seq_printf(seq, "dtsap_sel: %02x\n",
1846                    self->dtsap_sel);
1847         seq_printf(seq, "  connected: %s, ",
1848                    self->connected? "TRUE":"FALSE");
1849         seq_printf(seq, "avail credit: %d, ",
1850                    self->avail_credit);
1851         seq_printf(seq, "remote credit: %d, ",
1852                    self->remote_credit);
1853         seq_printf(seq, "send credit: %d\n",
1854                    self->send_credit);
1855         seq_printf(seq, "  tx packets: %ld, ",
1856                    self->stats.tx_packets);
1857         seq_printf(seq, "rx packets: %ld, ",
1858                    self->stats.rx_packets);
1859         seq_printf(seq, "tx_queue len: %d ",
1860                    skb_queue_len(&self->tx_queue));
1861         seq_printf(seq, "rx_queue len: %d\n",
1862                    skb_queue_len(&self->rx_queue));
1863         seq_printf(seq, "  tx_sdu_busy: %s, ",
1864                    self->tx_sdu_busy? "TRUE":"FALSE");
1865         seq_printf(seq, "rx_sdu_busy: %s\n",
1866                    self->rx_sdu_busy? "TRUE":"FALSE");
1867         seq_printf(seq, "  max_seg_size: %d, ",
1868                    self->max_seg_size);
1869         seq_printf(seq, "tx_max_sdu_size: %d, ",
1870                    self->tx_max_sdu_size);
1871         seq_printf(seq, "rx_max_sdu_size: %d\n",
1872                    self->rx_max_sdu_size);
1873
1874         seq_printf(seq, "  Used by (%s)\n\n",
1875                    self->notify.name);
1876         return 0;
1877 }
1878
1879 static const struct seq_operations irttp_seq_ops = {
1880         .start  = irttp_seq_start,
1881         .next   = irttp_seq_next,
1882         .stop   = irttp_seq_stop,
1883         .show   = irttp_seq_show,
1884 };
1885
1886 static int irttp_seq_open(struct inode *inode, struct file *file)
1887 {
1888         return seq_open_private(file, &irttp_seq_ops,
1889                         sizeof(struct irttp_iter_state));
1890 }
1891
1892 const struct file_operations irttp_seq_fops = {
1893         .owner          = THIS_MODULE,
1894         .open           = irttp_seq_open,
1895         .read           = seq_read,
1896         .llseek         = seq_lseek,
1897         .release        = seq_release_private,
1898 };
1899
1900 #endif /* PROC_FS */