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 #include <linux/slab.h>
  32 #include <linux/export.h>
  33
  34 #include <asm/byteorder.h>
  35 #include <asm/unaligned.h>
  36
  37 #include <net/irda/irda.h>
  38 #include <net/irda/irlap.h>
  39 #include <net/irda/irlmp.h>
  40 #include <net/irda/parameters.h>
  41 #include <net/irda/irttp.h>
  42
  43 static struct irttp_cb *irttp;
  44
  45 static void __irttp_close_tsap(struct tsap_cb *self);
  46
  47 static int irttp_data_indication(void *instance, void *sap,
  48                                  struct sk_buff *skb);
  49 static int irttp_udata_indication(void *instance, void *sap,
  50                                   struct sk_buff *skb);
  51 static void irttp_disconnect_indication(void *instance, void *sap,
  52                                         LM_REASON reason, struct sk_buff *);
  53 static void irttp_connect_indication(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_connect_confirm(void *instance, void *sap,
  57                                   struct qos_info *qos, __u32 max_sdu_size,
  58                                   __u8 header_size, struct sk_buff *skb);
  59 static void irttp_run_tx_queue(struct tsap_cb *self);
  60 static void irttp_run_rx_queue(struct tsap_cb *self);
  61
  62 static void irttp_flush_queues(struct tsap_cb *self);
  63 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  64 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  65 static void irttp_todo_expired(unsigned long data);
  66 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  67                                     int get);
  68
  69 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
  70 static void irttp_status_indication(void *instance,
  71                                     LINK_STATUS link, LOCK_STATUS lock);
  72
  73 /* Information for parsing parameters in IrTTP */
  74 static pi_minor_info_t pi_minor_call_table[] = {
  75         { NULL, 0 },                                             /* 0x00 */
  76         { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
  77 };
  78 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  79 static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  80
  81 /************************ GLOBAL PROCEDURES ************************/
  82
  83 /*
  84  * Function irttp_init (void)
  85  *
  86  *    Initialize the IrTTP layer. Called by module initialization code
  87  *
  88  */
  89 int __init irttp_init(void)
  90 {
  91         irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  92         if (irttp == NULL)
  93                 return -ENOMEM;
  94
  95         irttp->magic = TTP_MAGIC;
  96
  97         irttp->tsaps = hashbin_new(HB_LOCK);
  98         if (!irttp->tsaps) {
  99                 IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
 100                            __func__);
 101                 kfree(irttp);
 102                 return -ENOMEM;
 103         }
 104
 105         return 0;
 106 }
 107
 108 /*
 109  * Function irttp_cleanup (void)
 110  *
 111  *    Called by module destruction/cleanup code
 112  *
 113  */
 114 void irttp_cleanup(void)
 115 {
 116         /* Check for main structure */
 117         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
 118
 119         /*
 120          *  Delete hashbin and close all TSAP instances in it
 121          */
 122         hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
 123
 124         irttp->magic = 0;
 125
 126         /* De-allocate main structure */
 127         kfree(irttp);
 128
 129         irttp = NULL;
 130 }
 131
 132 /*************************** SUBROUTINES ***************************/
 133
 134 /*
 135  * Function irttp_start_todo_timer (self, timeout)
 136  *
 137  *    Start todo timer.
 138  *
 139  * Made it more effient and unsensitive to race conditions - Jean II
 140  */
 141 static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
 142 {
 143         /* Set new value for timer */
 144         mod_timer(&self->todo_timer, jiffies + timeout);
 145 }
 146
 147 /*
 148  * Function irttp_todo_expired (data)
 149  *
 150  *    Todo timer has expired!
 151  *
 152  * One of the restriction of the timer is that it is run only on the timer
 153  * interrupt which run every 10ms. This mean that even if you set the timer
 154  * with a delay of 0, it may take up to 10ms before it's run.
 155  * So, to minimise latency and keep cache fresh, we try to avoid using
 156  * it as much as possible.
 157  * Note : we can't use tasklets, because they can't be asynchronously
 158  * killed (need user context), and we can't guarantee that here...
 159  * Jean II
 160  */
 161 static void irttp_todo_expired(unsigned long data)
 162 {
 163         struct tsap_cb *self = (struct tsap_cb *) data;
 164
 165         /* Check that we still exist */
 166         if (!self || self->magic != TTP_TSAP_MAGIC)
 167                 return;
 168
 169         IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
 170
 171         /* Try to make some progress, especially on Tx side - Jean II */
 172         irttp_run_rx_queue(self);
 173         irttp_run_tx_queue(self);
 174
 175         /* Check if time for disconnect */
 176         if (test_bit(0, &self->disconnect_pend)) {
 177                 /* Check if it's possible to disconnect yet */
 178                 if (skb_queue_empty(&self->tx_queue)) {
 179                         /* Make sure disconnect is not pending anymore */
 180                         clear_bit(0, &self->disconnect_pend);   /* FALSE */
 181
 182                         /* Note : self->disconnect_skb may be NULL */
 183                         irttp_disconnect_request(self, self->disconnect_skb,
 184                                                  P_NORMAL);
 185                         self->disconnect_skb = NULL;
 186                 } else {
 187                         /* Try again later */
 188                         irttp_start_todo_timer(self, HZ/10);
 189
 190                         /* No reason to try and close now */
 191                         return;
 192                 }
 193         }
 194
 195         /* Check if it's closing time */
 196         if (self->close_pend)
 197                 /* Finish cleanup */
 198                 irttp_close_tsap(self);
 199 }
 200
 201 /*
 202  * Function irttp_flush_queues (self)
 203  *
 204  *     Flushes (removes all frames) in transitt-buffer (tx_list)
 205  */
 206 static void irttp_flush_queues(struct tsap_cb *self)
 207 {
 208         struct sk_buff* skb;
 209
 210         IRDA_DEBUG(4, "%s()\n", __func__);
 211
 212         IRDA_ASSERT(self != NULL, return;);
 213         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 214
 215         /* Deallocate frames waiting to be sent */
 216         while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
 217                 dev_kfree_skb(skb);
 218
 219         /* Deallocate received frames */
 220         while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
 221                 dev_kfree_skb(skb);
 222
 223         /* Deallocate received fragments */
 224         while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
 225                 dev_kfree_skb(skb);
 226 }
 227
 228 /*
 229  * Function irttp_reassemble (self)
 230  *
 231  *    Makes a new (continuous) skb of all the fragments in the fragment
 232  *    queue
 233  *
 234  */
 235 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
 236 {
 237         struct sk_buff *skb, *frag;
 238         int n = 0;  /* Fragment index */
 239
 240         IRDA_ASSERT(self != NULL, return NULL;);
 241         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
 242
 243         IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __func__,
 244                    self->rx_sdu_size);
 245
 246         skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
 247         if (!skb)
 248                 return NULL;
 249
 250         /*
 251          * Need to reserve space for TTP header in case this skb needs to
 252          * be requeued in case delivery failes
 253          */
 254         skb_reserve(skb, TTP_HEADER);
 255         skb_put(skb, self->rx_sdu_size);
 256
 257         /*
 258          *  Copy all fragments to a new buffer
 259          */
 260         while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
 261                 skb_copy_to_linear_data_offset(skb, n, frag->data, frag->len);
 262                 n += frag->len;
 263
 264                 dev_kfree_skb(frag);
 265         }
 266
 267         IRDA_DEBUG(2,
 268                    "%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
 269                    __func__, n, self->rx_sdu_size, self->rx_max_sdu_size);
 270         /* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
 271          * by summing the size of all fragments, so we should always
 272          * have n == self->rx_sdu_size, except in cases where we
 273          * droped the last fragment (when self->rx_sdu_size exceed
 274          * self->rx_max_sdu_size), where n < self->rx_sdu_size.
 275          * Jean II */
 276         IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
 277
 278         /* Set the new length */
 279         skb_trim(skb, n);
 280
 281         self->rx_sdu_size = 0;
 282
 283         return skb;
 284 }
 285
 286 /*
 287  * Function irttp_fragment_skb (skb)
 288  *
 289  *    Fragments a frame and queues all the fragments for transmission
 290  *
 291  */
 292 static inline void irttp_fragment_skb(struct tsap_cb *self,
 293                                       struct sk_buff *skb)
 294 {
 295         struct sk_buff *frag;
 296         __u8 *frame;
 297
 298         IRDA_DEBUG(2, "%s()\n", __func__);
 299
 300         IRDA_ASSERT(self != NULL, return;);
 301         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 302         IRDA_ASSERT(skb != NULL, return;);
 303
 304         /*
 305          *  Split frame into a number of segments
 306          */
 307         while (skb->len > self->max_seg_size) {
 308                 IRDA_DEBUG(2, "%s(), fragmenting ...\n", __func__);
 309
 310                 /* Make new segment */
 311                 frag = alloc_skb(self->max_seg_size+self->max_header_size,
 312                                  GFP_ATOMIC);
 313                 if (!frag)
 314                         return;
 315
 316                 skb_reserve(frag, self->max_header_size);
 317
 318                 /* Copy data from the original skb into this fragment. */
 319                 skb_copy_from_linear_data(skb, skb_put(frag, self->max_seg_size),
 320                               self->max_seg_size);
 321
 322                 /* Insert TTP header, with the more bit set */
 323                 frame = skb_push(frag, TTP_HEADER);
 324                 frame[0] = TTP_MORE;
 325
 326                 /* Hide the copied data from the original skb */
 327                 skb_pull(skb, self->max_seg_size);
 328
 329                 /* Queue fragment */
 330                 skb_queue_tail(&self->tx_queue, frag);
 331         }
 332         /* Queue what is left of the original skb */
 333         IRDA_DEBUG(2, "%s(), queuing last segment\n", __func__);
 334
 335         frame = skb_push(skb, TTP_HEADER);
 336         frame[0] = 0x00; /* Clear more bit */
 337
 338         /* Queue fragment */
 339         skb_queue_tail(&self->tx_queue, skb);
 340 }
 341
 342 /*
 343  * Function irttp_param_max_sdu_size (self, param)
 344  *
 345  *    Handle the MaxSduSize parameter in the connect frames, this function
 346  *    will be called both when this parameter needs to be inserted into, and
 347  *    extracted from the connect frames
 348  */
 349 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 350                                     int get)
 351 {
 352         struct tsap_cb *self;
 353
 354         self = instance;
 355
 356         IRDA_ASSERT(self != NULL, return -1;);
 357         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 358
 359         if (get)
 360                 param->pv.i = self->tx_max_sdu_size;
 361         else
 362                 self->tx_max_sdu_size = param->pv.i;
 363
 364         IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __func__, param->pv.i);
 365
 366         return 0;
 367 }
 368
 369 /*************************** CLIENT CALLS ***************************/
 370 /************************** LMP CALLBACKS **************************/
 371 /* Everything is happily mixed up. Waiting for next clean up - Jean II */
 372
 373 /*
 374  * Initialization, that has to be done on new tsap
 375  * instance allocation and on duplication
 376  */
 377 static void irttp_init_tsap(struct tsap_cb *tsap)
 378 {
 379         spin_lock_init(&tsap->lock);
 380         init_timer(&tsap->todo_timer);
 381
 382         skb_queue_head_init(&tsap->rx_queue);
 383         skb_queue_head_init(&tsap->tx_queue);
 384         skb_queue_head_init(&tsap->rx_fragments);
 385 }
 386
 387 /*
 388  * Function irttp_open_tsap (stsap, notify)
 389  *
 390  *    Create TSAP connection endpoint,
 391  */
 392 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 393 {
 394         struct tsap_cb *self;
 395         struct lsap_cb *lsap;
 396         notify_t ttp_notify;
 397
 398         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 399
 400         /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 401          * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 402          * JeanII */
 403         if((stsap_sel != LSAP_ANY) &&
 404            ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 405                 IRDA_DEBUG(0, "%s(), invalid tsap!\n", __func__);
 406                 return NULL;
 407         }
 408
 409         self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 410         if (self == NULL) {
 411                 IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __func__);
 412                 return NULL;
 413         }
 414
 415         /* Initialize internal objects */
 416         irttp_init_tsap(self);
 417
 418         /* Initialise todo timer */
 419         self->todo_timer.data     = (unsigned long) self;
 420         self->todo_timer.function = &irttp_todo_expired;
 421
 422         /* Initialize callbacks for IrLMP to use */
 423         irda_notify_init(&ttp_notify);
 424         ttp_notify.connect_confirm = irttp_connect_confirm;
 425         ttp_notify.connect_indication = irttp_connect_indication;
 426         ttp_notify.disconnect_indication = irttp_disconnect_indication;
 427         ttp_notify.data_indication = irttp_data_indication;
 428         ttp_notify.udata_indication = irttp_udata_indication;
 429         ttp_notify.flow_indication = irttp_flow_indication;
 430         if(notify->status_indication != NULL)
 431                 ttp_notify.status_indication = irttp_status_indication;
 432         ttp_notify.instance = self;
 433         strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 434
 435         self->magic = TTP_TSAP_MAGIC;
 436         self->connected = FALSE;
 437
 438         /*
 439          *  Create LSAP at IrLMP layer
 440          */
 441         lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 442         if (lsap == NULL) {
 443                 IRDA_DEBUG(0, "%s: unable to allocate LSAP!!\n", __func__);
 444                 return NULL;
 445         }
 446
 447         /*
 448          *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 449          *  will replace it with whatever source selector which is free, so
 450          *  the stsap_sel we have might not be valid anymore
 451          */
 452         self->stsap_sel = lsap->slsap_sel;
 453         IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
 454
 455         self->notify = *notify;
 456         self->lsap = lsap;
 457
 458         hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 459
 460         if (credit > TTP_RX_MAX_CREDIT)
 461                 self->initial_credit = TTP_RX_MAX_CREDIT;
 462         else
 463                 self->initial_credit = credit;
 464
 465         return self;
 466 }
 467 EXPORT_SYMBOL(irttp_open_tsap);
 468
 469 /*
 470  * Function irttp_close (handle)
 471  *
 472  *    Remove an instance of a TSAP. This function should only deal with the
 473  *    deallocation of the TSAP, and resetting of the TSAPs values;
 474  *
 475  */
 476 static void __irttp_close_tsap(struct tsap_cb *self)
 477 {
 478         /* First make sure we're connected. */
 479         IRDA_ASSERT(self != NULL, return;);
 480         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 481
 482         irttp_flush_queues(self);
 483
 484         del_timer(&self->todo_timer);
 485
 486         /* This one won't be cleaned up if we are disconnect_pend + close_pend
 487          * and we receive a disconnect_indication */
 488         if (self->disconnect_skb)
 489                 dev_kfree_skb(self->disconnect_skb);
 490
 491         self->connected = FALSE;
 492         self->magic = ~TTP_TSAP_MAGIC;
 493
 494         kfree(self);
 495 }
 496
 497 /*
 498  * Function irttp_close (self)
 499  *
 500  *    Remove TSAP from list of all TSAPs and then deallocate all resources
 501  *    associated with this TSAP
 502  *
 503  * Note : because we *free* the tsap structure, it is the responsibility
 504  * of the caller to make sure we are called only once and to deal with
 505  * possible race conditions. - Jean II
 506  */
 507 int irttp_close_tsap(struct tsap_cb *self)
 508 {
 509         struct tsap_cb *tsap;
 510
 511         IRDA_DEBUG(4, "%s()\n", __func__);
 512
 513         IRDA_ASSERT(self != NULL, return -1;);
 514         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 515
 516         /* Make sure tsap has been disconnected */
 517         if (self->connected) {
 518                 /* Check if disconnect is not pending */
 519                 if (!test_bit(0, &self->disconnect_pend)) {
 520                         IRDA_WARNING("%s: TSAP still connected!\n",
 521                                      __func__);
 522                         irttp_disconnect_request(self, NULL, P_NORMAL);
 523                 }
 524                 self->close_pend = TRUE;
 525                 irttp_start_todo_timer(self, HZ/10);
 526
 527                 return 0; /* Will be back! */
 528         }
 529
 530         tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 531
 532         IRDA_ASSERT(tsap == self, return -1;);
 533
 534         /* Close corresponding LSAP */
 535         if (self->lsap) {
 536                 irlmp_close_lsap(self->lsap);
 537                 self->lsap = NULL;
 538         }
 539
 540         __irttp_close_tsap(self);
 541
 542         return 0;
 543 }
 544 EXPORT_SYMBOL(irttp_close_tsap);
 545
 546 /*
 547  * Function irttp_udata_request (self, skb)
 548  *
 549  *    Send unreliable data on this TSAP
 550  *
 551  */
 552 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 553 {
 554         int ret;
 555
 556         IRDA_ASSERT(self != NULL, return -1;);
 557         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 558         IRDA_ASSERT(skb != NULL, return -1;);
 559
 560         IRDA_DEBUG(4, "%s()\n", __func__);
 561
 562         /* Take shortcut on zero byte packets */
 563         if (skb->len == 0) {
 564                 ret = 0;
 565                 goto err;
 566         }
 567
 568         /* Check that nothing bad happens */
 569         if (!self->connected) {
 570                 IRDA_WARNING("%s(), Not connected\n", __func__);
 571                 ret = -ENOTCONN;
 572                 goto err;
 573         }
 574
 575         if (skb->len > self->max_seg_size) {
 576                 IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
 577                 ret = -EMSGSIZE;
 578                 goto err;
 579         }
 580
 581         irlmp_udata_request(self->lsap, skb);
 582         self->stats.tx_packets++;
 583
 584         return 0;
 585
 586 err:
 587         dev_kfree_skb(skb);
 588         return ret;
 589 }
 590 EXPORT_SYMBOL(irttp_udata_request);
 591
 592
 593 /*
 594  * Function irttp_data_request (handle, skb)
 595  *
 596  *    Queue frame for transmission. If SAR is enabled, fragement the frame
 597  *    and queue the fragments for transmission
 598  */
 599 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 600 {
 601         __u8 *frame;
 602         int ret;
 603
 604         IRDA_ASSERT(self != NULL, return -1;);
 605         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 606         IRDA_ASSERT(skb != NULL, return -1;);
 607
 608         IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
 609                    skb_queue_len(&self->tx_queue));
 610
 611         /* Take shortcut on zero byte packets */
 612         if (skb->len == 0) {
 613                 ret = 0;
 614                 goto err;
 615         }
 616
 617         /* Check that nothing bad happens */
 618         if (!self->connected) {
 619                 IRDA_WARNING("%s: Not connected\n", __func__);
 620                 ret = -ENOTCONN;
 621                 goto err;
 622         }
 623
 624         /*
 625          *  Check if SAR is disabled, and the frame is larger than what fits
 626          *  inside an IrLAP frame
 627          */
 628         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 629                 IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
 630                            __func__);
 631                 ret = -EMSGSIZE;
 632                 goto err;
 633         }
 634
 635         /*
 636          *  Check if SAR is enabled, and the frame is larger than the
 637          *  TxMaxSduSize
 638          */
 639         if ((self->tx_max_sdu_size != 0) &&
 640             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 641             (skb->len > self->tx_max_sdu_size))
 642         {
 643                 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 644                            __func__);
 645                 ret = -EMSGSIZE;
 646                 goto err;
 647         }
 648         /*
 649          *  Check if transmit queue is full
 650          */
 651         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 652                 /*
 653                  *  Give it a chance to empty itself
 654                  */
 655                 irttp_run_tx_queue(self);
 656
 657                 /* Drop packet. This error code should trigger the caller
 658                  * to resend the data in the client code - Jean II */
 659                 ret = -ENOBUFS;
 660                 goto err;
 661         }
 662
 663         /* Queue frame, or queue frame segments */
 664         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 665                 /* Queue frame */
 666                 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 667                 frame = skb_push(skb, TTP_HEADER);
 668                 frame[0] = 0x00; /* Clear more bit */
 669
 670                 skb_queue_tail(&self->tx_queue, skb);
 671         } else {
 672                 /*
 673                  *  Fragment the frame, this function will also queue the
 674                  *  fragments, we don't care about the fact the transmit
 675                  *  queue may be overfilled by all the segments for a little
 676                  *  while
 677                  */
 678                 irttp_fragment_skb(self, skb);
 679         }
 680
 681         /* Check if we can accept more data from client */
 682         if ((!self->tx_sdu_busy) &&
 683             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 684                 /* Tx queue filling up, so stop client. */
 685                 if (self->notify.flow_indication) {
 686                         self->notify.flow_indication(self->notify.instance,
 687                                                      self, FLOW_STOP);
 688                 }
 689                 /* self->tx_sdu_busy is the state of the client.
 690                  * Update state after notifying client to avoid
 691                  * race condition with irttp_flow_indication().
 692                  * If the queue empty itself after our test but before
 693                  * we set the flag, we will fix ourselves below in
 694                  * irttp_run_tx_queue().
 695                  * Jean II */
 696                 self->tx_sdu_busy = TRUE;
 697         }
 698
 699         /* Try to make some progress */
 700         irttp_run_tx_queue(self);
 701
 702         return 0;
 703
 704 err:
 705         dev_kfree_skb(skb);
 706         return ret;
 707 }
 708 EXPORT_SYMBOL(irttp_data_request);
 709
 710 /*
 711  * Function irttp_run_tx_queue (self)
 712  *
 713  *    Transmit packets queued for transmission (if possible)
 714  *
 715  */
 716 static void irttp_run_tx_queue(struct tsap_cb *self)
 717 {
 718         struct sk_buff *skb;
 719         unsigned long flags;
 720         int n;
 721
 722         IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 723                    __func__,
 724                    self->send_credit, skb_queue_len(&self->tx_queue));
 725
 726         /* Get exclusive access to the tx queue, otherwise don't touch it */
 727         if (irda_lock(&self->tx_queue_lock) == FALSE)
 728                 return;
 729
 730         /* Try to send out frames as long as we have credits
 731          * and as long as LAP is not full. If LAP is full, it will
 732          * poll us through irttp_flow_indication() - Jean II */
 733         while ((self->send_credit > 0) &&
 734                (!irlmp_lap_tx_queue_full(self->lsap)) &&
 735                (skb = skb_dequeue(&self->tx_queue)))
 736         {
 737                 /*
 738                  *  Since we can transmit and receive frames concurrently,
 739                  *  the code below is a critical region and we must assure that
 740                  *  nobody messes with the credits while we update them.
 741                  */
 742                 spin_lock_irqsave(&self->lock, flags);
 743
 744                 n = self->avail_credit;
 745                 self->avail_credit = 0;
 746
 747                 /* Only room for 127 credits in frame */
 748                 if (n > 127) {
 749                         self->avail_credit = n-127;
 750                         n = 127;
 751                 }
 752                 self->remote_credit += n;
 753                 self->send_credit--;
 754
 755                 spin_unlock_irqrestore(&self->lock, flags);
 756
 757                 /*
 758                  *  More bit must be set by the data_request() or fragment()
 759                  *  functions
 760                  */
 761                 skb->data[0] |= (n & 0x7f);
 762
 763                 /* Detach from socket.
 764                  * The current skb has a reference to the socket that sent
 765                  * it (skb->sk). When we pass it to IrLMP, the skb will be
 766                  * stored in in IrLAP (self->wx_list). When we are within
 767                  * IrLAP, we lose the notion of socket, so we should not
 768                  * have a reference to a socket. So, we drop it here.
 769                  *
 770                  * Why does it matter ?
 771                  * When the skb is freed (kfree_skb), if it is associated
 772                  * with a socket, it release buffer space on the socket
 773                  * (through sock_wfree() and sock_def_write_space()).
 774                  * If the socket no longer exist, we may crash. Hard.
 775                  * When we close a socket, we make sure that associated packets
 776                  * in IrTTP are freed. However, we have no way to cancel
 777                  * the packet that we have passed to IrLAP. So, if a packet
 778                  * remains in IrLAP (retry on the link or else) after we
 779                  * close the socket, we are dead !
 780                  * Jean II */
 781                 if (skb->sk != NULL) {
 782                         /* IrSOCK application, IrOBEX, ... */
 783                         skb_orphan(skb);
 784                 }
 785                         /* IrCOMM over IrTTP, IrLAN, ... */
 786
 787                 /* Pass the skb to IrLMP - done */
 788                 irlmp_data_request(self->lsap, skb);
 789                 self->stats.tx_packets++;
 790         }
 791
 792         /* Check if we can accept more frames from client.
 793          * We don't want to wait until the todo timer to do that, and we
 794          * can't use tasklets (grr...), so we are obliged to give control
 795          * to client. That's ok, this test will be true not too often
 796          * (max once per LAP window) and we are called from places
 797          * where we can spend a bit of time doing stuff. - Jean II */
 798         if ((self->tx_sdu_busy) &&
 799             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 800             (!self->close_pend))
 801         {
 802                 if (self->notify.flow_indication)
 803                         self->notify.flow_indication(self->notify.instance,
 804                                                      self, FLOW_START);
 805
 806                 /* self->tx_sdu_busy is the state of the client.
 807                  * We don't really have a race here, but it's always safer
 808                  * to update our state after the client - Jean II */
 809                 self->tx_sdu_busy = FALSE;
 810         }
 811
 812         /* Reset lock */
 813         self->tx_queue_lock = 0;
 814 }
 815
 816 /*
 817  * Function irttp_give_credit (self)
 818  *
 819  *    Send a dataless flowdata TTP-PDU and give available credit to peer
 820  *    TSAP
 821  */
 822 static inline void irttp_give_credit(struct tsap_cb *self)
 823 {
 824         struct sk_buff *tx_skb = NULL;
 825         unsigned long flags;
 826         int n;
 827
 828         IRDA_ASSERT(self != NULL, return;);
 829         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 830
 831         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 832                    __func__,
 833                    self->send_credit, self->avail_credit, self->remote_credit);
 834
 835         /* Give credit to peer */
 836         tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
 837         if (!tx_skb)
 838                 return;
 839
 840         /* Reserve space for LMP, and LAP header */
 841         skb_reserve(tx_skb, LMP_MAX_HEADER);
 842
 843         /*
 844          *  Since we can transmit and receive frames concurrently,
 845          *  the code below is a critical region and we must assure that
 846          *  nobody messes with the credits while we update them.
 847          */
 848         spin_lock_irqsave(&self->lock, flags);
 849
 850         n = self->avail_credit;
 851         self->avail_credit = 0;
 852
 853         /* Only space for 127 credits in frame */
 854         if (n > 127) {
 855                 self->avail_credit = n - 127;
 856                 n = 127;
 857         }
 858         self->remote_credit += n;
 859
 860         spin_unlock_irqrestore(&self->lock, flags);
 861
 862         skb_put(tx_skb, 1);
 863         tx_skb->data[0] = (__u8) (n & 0x7f);
 864
 865         irlmp_data_request(self->lsap, tx_skb);
 866         self->stats.tx_packets++;
 867 }
 868
 869 /*
 870  * Function irttp_udata_indication (instance, sap, skb)
 871  *
 872  *    Received some unit-data (unreliable)
 873  *
 874  */
 875 static int irttp_udata_indication(void *instance, void *sap,
 876                                   struct sk_buff *skb)
 877 {
 878         struct tsap_cb *self;
 879         int err;
 880
 881         IRDA_DEBUG(4, "%s()\n", __func__);
 882
 883         self = instance;
 884
 885         IRDA_ASSERT(self != NULL, return -1;);
 886         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 887         IRDA_ASSERT(skb != NULL, return -1;);
 888
 889         self->stats.rx_packets++;
 890
 891         /* Just pass data to layer above */
 892         if (self->notify.udata_indication) {
 893                 err = self->notify.udata_indication(self->notify.instance,
 894                                                     self,skb);
 895                 /* Same comment as in irttp_do_data_indication() */
 896                 if (!err)
 897                         return 0;
 898         }
 899         /* Either no handler, or handler returns an error */
 900         dev_kfree_skb(skb);
 901
 902         return 0;
 903 }
 904
 905 /*
 906  * Function irttp_data_indication (instance, sap, skb)
 907  *
 908  *    Receive segment from IrLMP.
 909  *
 910  */
 911 static int irttp_data_indication(void *instance, void *sap,
 912                                  struct sk_buff *skb)
 913 {
 914         struct tsap_cb *self;
 915         unsigned long flags;
 916         int n;
 917
 918         self = instance;
 919
 920         n = skb->data[0] & 0x7f;     /* Extract the credits */
 921
 922         self->stats.rx_packets++;
 923
 924         /*  Deal with inbound credit
 925          *  Since we can transmit and receive frames concurrently,
 926          *  the code below is a critical region and we must assure that
 927          *  nobody messes with the credits while we update them.
 928          */
 929         spin_lock_irqsave(&self->lock, flags);
 930         self->send_credit += n;
 931         if (skb->len > 1)
 932                 self->remote_credit--;
 933         spin_unlock_irqrestore(&self->lock, flags);
 934
 935         /*
 936          *  Data or dataless packet? Dataless frames contains only the
 937          *  TTP_HEADER.
 938          */
 939         if (skb->len > 1) {
 940                 /*
 941                  *  We don't remove the TTP header, since we must preserve the
 942                  *  more bit, so the defragment routing knows what to do
 943                  */
 944                 skb_queue_tail(&self->rx_queue, skb);
 945         } else {
 946                 /* Dataless flowdata TTP-PDU */
 947                 dev_kfree_skb(skb);
 948         }
 949
 950
 951         /* Push data to the higher layer.
 952          * We do it synchronously because running the todo timer for each
 953          * receive packet would be too much overhead and latency.
 954          * By passing control to the higher layer, we run the risk that
 955          * it may take time or grab a lock. Most often, the higher layer
 956          * will only put packet in a queue.
 957          * Anyway, packets are only dripping through the IrDA, so we can
 958          * have time before the next packet.
 959          * Further, we are run from NET_BH, so the worse that can happen is
 960          * us missing the optimal time to send back the PF bit in LAP.
 961          * Jean II */
 962         irttp_run_rx_queue(self);
 963
 964         /* We now give credits to peer in irttp_run_rx_queue().
 965          * We need to send credit *NOW*, otherwise we are going
 966          * to miss the next Tx window. The todo timer may take
 967          * a while before it's run... - Jean II */
 968
 969         /*
 970          * If the peer device has given us some credits and we didn't have
 971          * anyone from before, then we need to shedule the tx queue.
 972          * We need to do that because our Tx have stopped (so we may not
 973          * get any LAP flow indication) and the user may be stopped as
 974          * well. - Jean II
 975          */
 976         if (self->send_credit == n) {
 977                 /* Restart pushing stuff to LAP */
 978                 irttp_run_tx_queue(self);
 979                 /* Note : we don't want to schedule the todo timer
 980                  * because it has horrible latency. No tasklets
 981                  * because the tasklet API is broken. - Jean II */
 982         }
 983
 984         return 0;
 985 }
 986
 987 /*
 988  * Function irttp_status_indication (self, reason)
 989  *
 990  *    Status_indication, just pass to the higher layer...
 991  *
 992  */
 993 static void irttp_status_indication(void *instance,
 994                                     LINK_STATUS link, LOCK_STATUS lock)
 995 {
 996         struct tsap_cb *self;
 997
 998         IRDA_DEBUG(4, "%s()\n", __func__);
 999
1000         self = instance;
1001
1002         IRDA_ASSERT(self != NULL, return;);
1003         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1004
1005         /* Check if client has already closed the TSAP and gone away */
1006         if (self->close_pend)
1007                 return;
1008
1009         /*
1010          *  Inform service user if he has requested it
1011          */
1012         if (self->notify.status_indication != NULL)
1013                 self->notify.status_indication(self->notify.instance,
1014                                                link, lock);
1015         else
1016                 IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1017 }
1018
1019 /*
1020  * Function irttp_flow_indication (self, reason)
1021  *
1022  *    Flow_indication : IrLAP tells us to send more data.
1023  *
1024  */
1025 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1026 {
1027         struct tsap_cb *self;
1028
1029         self = instance;
1030
1031         IRDA_ASSERT(self != NULL, return;);
1032         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1033
1034         IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1035
1036         /* We are "polled" directly from LAP, and the LAP want to fill
1037          * its Tx window. We want to do our best to send it data, so that
1038          * we maximise the window. On the other hand, we want to limit the
1039          * amount of work here so that LAP doesn't hang forever waiting
1040          * for packets. - Jean II */
1041
1042         /* Try to send some packets. Currently, LAP calls us every time
1043          * there is one free slot, so we will send only one packet.
1044          * This allow the scheduler to do its round robin - Jean II */
1045         irttp_run_tx_queue(self);
1046
1047         /* Note regarding the interraction with higher layer.
1048          * irttp_run_tx_queue() may call the client when its queue
1049          * start to empty, via notify.flow_indication(). Initially.
1050          * I wanted this to happen in a tasklet, to avoid client
1051          * grabbing the CPU, but we can't use tasklets safely. And timer
1052          * is definitely too slow.
1053          * This will happen only once per LAP window, and usually at
1054          * the third packet (unless window is smaller). LAP is still
1055          * doing mtt and sending first packet so it's sort of OK
1056          * to do that. Jean II */
1057
1058         /* If we need to send disconnect. try to do it now */
1059         if(self->disconnect_pend)
1060                 irttp_start_todo_timer(self, 0);
1061 }
1062
1063 /*
1064  * Function irttp_flow_request (self, command)
1065  *
1066  *    This function could be used by the upper layers to tell IrTTP to stop
1067  *    delivering frames if the receive queues are starting to get full, or
1068  *    to tell IrTTP to start delivering frames again.
1069  */
1070 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1071 {
1072         IRDA_DEBUG(1, "%s()\n", __func__);
1073
1074         IRDA_ASSERT(self != NULL, return;);
1075         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1076
1077         switch (flow) {
1078         case FLOW_STOP:
1079                 IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1080                 self->rx_sdu_busy = TRUE;
1081                 break;
1082         case FLOW_START:
1083                 IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1084                 self->rx_sdu_busy = FALSE;
1085
1086                 /* Client say he can accept more data, try to free our
1087                  * queues ASAP - Jean II */
1088                 irttp_run_rx_queue(self);
1089
1090                 break;
1091         default:
1092                 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1093         }
1094 }
1095 EXPORT_SYMBOL(irttp_flow_request);
1096
1097 /*
1098  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1099  *
1100  *    Try to connect to remote destination TSAP selector
1101  *
1102  */
1103 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1104                           __u32 saddr, __u32 daddr,
1105                           struct qos_info *qos, __u32 max_sdu_size,
1106                           struct sk_buff *userdata)
1107 {
1108         struct sk_buff *tx_skb;
1109         __u8 *frame;
1110         __u8 n;
1111
1112         IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1113
1114         IRDA_ASSERT(self != NULL, return -EBADR;);
1115         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1116
1117         if (self->connected) {
1118                 if(userdata)
1119                         dev_kfree_skb(userdata);
1120                 return -EISCONN;
1121         }
1122
1123         /* Any userdata supplied? */
1124         if (userdata == NULL) {
1125                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1126                                    GFP_ATOMIC);
1127                 if (!tx_skb)
1128                         return -ENOMEM;
1129
1130                 /* Reserve space for MUX_CONTROL and LAP header */
1131                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1132         } else {
1133                 tx_skb = userdata;
1134                 /*
1135                  *  Check that the client has reserved enough space for
1136                  *  headers
1137                  */
1138                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1139                         { dev_kfree_skb(userdata); return -1; } );
1140         }
1141
1142         /* Initialize connection parameters */
1143         self->connected = FALSE;
1144         self->avail_credit = 0;
1145         self->rx_max_sdu_size = max_sdu_size;
1146         self->rx_sdu_size = 0;
1147         self->rx_sdu_busy = FALSE;
1148         self->dtsap_sel = dtsap_sel;
1149
1150         n = self->initial_credit;
1151
1152         self->remote_credit = 0;
1153         self->send_credit = 0;
1154
1155         /*
1156          *  Give away max 127 credits for now
1157          */
1158         if (n > 127) {
1159                 self->avail_credit=n-127;
1160                 n = 127;
1161         }
1162
1163         self->remote_credit = n;
1164
1165         /* SAR enabled? */
1166         if (max_sdu_size > 0) {
1167                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1168                         { dev_kfree_skb(tx_skb); return -1; } );
1169
1170                 /* Insert SAR parameters */
1171                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1172
1173                 frame[0] = TTP_PARAMETERS | n;
1174                 frame[1] = 0x04; /* Length */
1175                 frame[2] = 0x01; /* MaxSduSize */
1176                 frame[3] = 0x02; /* Value length */
1177
1178                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1179                               (__be16 *)(frame+4));
1180         } else {
1181                 /* Insert plain TTP header */
1182                 frame = skb_push(tx_skb, TTP_HEADER);
1183
1184                 /* Insert initial credit in frame */
1185                 frame[0] = n & 0x7f;
1186         }
1187
1188         /* Connect with IrLMP. No QoS parameters for now */
1189         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1190                                      tx_skb);
1191 }
1192 EXPORT_SYMBOL(irttp_connect_request);
1193
1194 /*
1195  * Function irttp_connect_confirm (handle, qos, skb)
1196  *
1197  *    Service user confirms TSAP connection with peer.
1198  *
1199  */
1200 static void irttp_connect_confirm(void *instance, void *sap,
1201                                   struct qos_info *qos, __u32 max_seg_size,
1202                                   __u8 max_header_size, struct sk_buff *skb)
1203 {
1204         struct tsap_cb *self;
1205         int parameters;
1206         int ret;
1207         __u8 plen;
1208         __u8 n;
1209
1210         IRDA_DEBUG(4, "%s()\n", __func__);
1211
1212         self = instance;
1213
1214         IRDA_ASSERT(self != NULL, return;);
1215         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1216         IRDA_ASSERT(skb != NULL, return;);
1217
1218         self->max_seg_size = max_seg_size - TTP_HEADER;
1219         self->max_header_size = max_header_size + TTP_HEADER;
1220
1221         /*
1222          *  Check if we have got some QoS parameters back! This should be the
1223          *  negotiated QoS for the link.
1224          */
1225         if (qos) {
1226                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1227                        qos->baud_rate.bits);
1228                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1229                        qos->baud_rate.value);
1230         }
1231
1232         n = skb->data[0] & 0x7f;
1233
1234         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1235
1236         self->send_credit = n;
1237         self->tx_max_sdu_size = 0;
1238         self->connected = TRUE;
1239
1240         parameters = skb->data[0] & 0x80;
1241
1242         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1243         skb_pull(skb, TTP_HEADER);
1244
1245         if (parameters) {
1246                 plen = skb->data[0];
1247
1248                 ret = irda_param_extract_all(self, skb->data+1,
1249                                              IRDA_MIN(skb->len-1, plen),
1250                                              &param_info);
1251
1252                 /* Any errors in the parameter list? */
1253                 if (ret < 0) {
1254                         IRDA_WARNING("%s: error extracting parameters\n",
1255                                      __func__);
1256                         dev_kfree_skb(skb);
1257
1258                         /* Do not accept this connection attempt */
1259                         return;
1260                 }
1261                 /* Remove parameters */
1262                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1263         }
1264
1265         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1266               self->send_credit, self->avail_credit, self->remote_credit);
1267
1268         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1269                    self->tx_max_sdu_size);
1270
1271         if (self->notify.connect_confirm) {
1272                 self->notify.connect_confirm(self->notify.instance, self, qos,
1273                                              self->tx_max_sdu_size,
1274                                              self->max_header_size, skb);
1275         } else
1276                 dev_kfree_skb(skb);
1277 }
1278
1279 /*
1280  * Function irttp_connect_indication (handle, skb)
1281  *
1282  *    Some other device is connecting to this TSAP
1283  *
1284  */
1285 static void irttp_connect_indication(void *instance, void *sap,
1286                 struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1287                 struct sk_buff *skb)
1288 {
1289         struct tsap_cb *self;
1290         struct lsap_cb *lsap;
1291         int parameters;
1292         int ret;
1293         __u8 plen;
1294         __u8 n;
1295
1296         self = instance;
1297
1298         IRDA_ASSERT(self != NULL, return;);
1299         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1300         IRDA_ASSERT(skb != NULL, return;);
1301
1302         lsap = sap;
1303
1304         self->max_seg_size = max_seg_size - TTP_HEADER;
1305         self->max_header_size = max_header_size+TTP_HEADER;
1306
1307         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1308
1309         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1310         self->dtsap_sel = lsap->dlsap_sel;
1311
1312         n = skb->data[0] & 0x7f;
1313
1314         self->send_credit = n;
1315         self->tx_max_sdu_size = 0;
1316
1317         parameters = skb->data[0] & 0x80;
1318
1319         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1320         skb_pull(skb, TTP_HEADER);
1321
1322         if (parameters) {
1323                 plen = skb->data[0];
1324
1325                 ret = irda_param_extract_all(self, skb->data+1,
1326                                              IRDA_MIN(skb->len-1, plen),
1327                                              &param_info);
1328
1329                 /* Any errors in the parameter list? */
1330                 if (ret < 0) {
1331                         IRDA_WARNING("%s: error extracting parameters\n",
1332                                      __func__);
1333                         dev_kfree_skb(skb);
1334
1335                         /* Do not accept this connection attempt */
1336                         return;
1337                 }
1338
1339                 /* Remove parameters */
1340                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1341         }
1342
1343         if (self->notify.connect_indication) {
1344                 self->notify.connect_indication(self->notify.instance, self,
1345                                                 qos, self->tx_max_sdu_size,
1346                                                 self->max_header_size, skb);
1347         } else
1348                 dev_kfree_skb(skb);
1349 }
1350
1351 /*
1352  * Function irttp_connect_response (handle, userdata)
1353  *
1354  *    Service user is accepting the connection, just pass it down to
1355  *    IrLMP!
1356  *
1357  */
1358 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1359                            struct sk_buff *userdata)
1360 {
1361         struct sk_buff *tx_skb;
1362         __u8 *frame;
1363         int ret;
1364         __u8 n;
1365
1366         IRDA_ASSERT(self != NULL, return -1;);
1367         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1368
1369         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1370                    self->stsap_sel);
1371
1372         /* Any userdata supplied? */
1373         if (userdata == NULL) {
1374                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1375                                    GFP_ATOMIC);
1376                 if (!tx_skb)
1377                         return -ENOMEM;
1378
1379                 /* Reserve space for MUX_CONTROL and LAP header */
1380                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1381         } else {
1382                 tx_skb = userdata;
1383                 /*
1384                  *  Check that the client has reserved enough space for
1385                  *  headers
1386                  */
1387                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1388                         { dev_kfree_skb(userdata); return -1; } );
1389         }
1390
1391         self->avail_credit = 0;
1392         self->remote_credit = 0;
1393         self->rx_max_sdu_size = max_sdu_size;
1394         self->rx_sdu_size = 0;
1395         self->rx_sdu_busy = FALSE;
1396
1397         n = self->initial_credit;
1398
1399         /* Frame has only space for max 127 credits (7 bits) */
1400         if (n > 127) {
1401                 self->avail_credit = n - 127;
1402                 n = 127;
1403         }
1404
1405         self->remote_credit = n;
1406         self->connected = TRUE;
1407
1408         /* SAR enabled? */
1409         if (max_sdu_size > 0) {
1410                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1411                         { dev_kfree_skb(tx_skb); return -1; } );
1412
1413                 /* Insert TTP header with SAR parameters */
1414                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1415
1416                 frame[0] = TTP_PARAMETERS | n;
1417                 frame[1] = 0x04; /* Length */
1418
1419                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1420 /*                                TTP_SAR_HEADER, &param_info) */
1421
1422                 frame[2] = 0x01; /* MaxSduSize */
1423                 frame[3] = 0x02; /* Value length */
1424
1425                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1426                               (__be16 *)(frame+4));
1427         } else {
1428                 /* Insert TTP header */
1429                 frame = skb_push(tx_skb, TTP_HEADER);
1430
1431                 frame[0] = n & 0x7f;
1432         }
1433
1434         ret = irlmp_connect_response(self->lsap, tx_skb);
1435
1436         return ret;
1437 }
1438 EXPORT_SYMBOL(irttp_connect_response);
1439
1440 /*
1441  * Function irttp_dup (self, instance)
1442  *
1443  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1444  *    new TSAP so it can keep listening on the old one.
1445  */
1446 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1447 {
1448         struct tsap_cb *new;
1449         unsigned long flags;
1450
1451         IRDA_DEBUG(1, "%s()\n", __func__);
1452
1453         /* Protect our access to the old tsap instance */
1454         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1455
1456         /* Find the old instance */
1457         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1458                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1459                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1460                 return NULL;
1461         }
1462
1463         /* Allocate a new instance */
1464         new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
1465         if (!new) {
1466                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1467                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1468                 return NULL;
1469         }
1470         spin_lock_init(&new->lock);
1471
1472         /* We don't need the old instance any more */
1473         spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1474
1475         /* Try to dup the LSAP (may fail if we were too slow) */
1476         new->lsap = irlmp_dup(orig->lsap, new);
1477         if (!new->lsap) {
1478                 IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1479                 kfree(new);
1480                 return NULL;
1481         }
1482
1483         /* Not everything should be copied */
1484         new->notify.instance = instance;
1485
1486         /* Initialize internal objects */
1487         irttp_init_tsap(new);
1488
1489         /* This is locked */
1490         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1491
1492         return new;
1493 }
1494 EXPORT_SYMBOL(irttp_dup);
1495
1496 /*
1497  * Function irttp_disconnect_request (self)
1498  *
1499  *    Close this connection please! If priority is high, the queued data
1500  *    segments, if any, will be deallocated first
1501  *
1502  */
1503 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1504                              int priority)
1505 {
1506         int ret;
1507
1508         IRDA_ASSERT(self != NULL, return -1;);
1509         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1510
1511         /* Already disconnected? */
1512         if (!self->connected) {
1513                 IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1514                 if (userdata)
1515                         dev_kfree_skb(userdata);
1516                 return -1;
1517         }
1518
1519         /* Disconnect already pending ?
1520          * We need to use an atomic operation to prevent reentry. This
1521          * function may be called from various context, like user, timer
1522          * for following a disconnect_indication() (i.e. net_bh).
1523          * Jean II */
1524         if(test_and_set_bit(0, &self->disconnect_pend)) {
1525                 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1526                            __func__);
1527                 if (userdata)
1528                         dev_kfree_skb(userdata);
1529
1530                 /* Try to make some progress */
1531                 irttp_run_tx_queue(self);
1532                 return -1;
1533         }
1534
1535         /*
1536          *  Check if there is still data segments in the transmit queue
1537          */
1538         if (!skb_queue_empty(&self->tx_queue)) {
1539                 if (priority == P_HIGH) {
1540                         /*
1541                          *  No need to send the queued data, if we are
1542                          *  disconnecting right now since the data will
1543                          *  not have any usable connection to be sent on
1544                          */
1545                         IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1546                         irttp_flush_queues(self);
1547                 } else if (priority == P_NORMAL) {
1548                         /*
1549                          *  Must delay disconnect until after all data segments
1550                          *  have been sent and the tx_queue is empty
1551                          */
1552                         /* We'll reuse this one later for the disconnect */
1553                         self->disconnect_skb = userdata;  /* May be NULL */
1554
1555                         irttp_run_tx_queue(self);
1556
1557                         irttp_start_todo_timer(self, HZ/10);
1558                         return -1;
1559                 }
1560         }
1561         /* Note : we don't need to check if self->rx_queue is full and the
1562          * state of self->rx_sdu_busy because the disconnect response will
1563          * be sent at the LMP level (so even if the peer has its Tx queue
1564          * full of data). - Jean II */
1565
1566         IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1567         self->connected = FALSE;
1568
1569         if (!userdata) {
1570                 struct sk_buff *tx_skb;
1571                 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1572                 if (!tx_skb)
1573                         return -ENOMEM;
1574
1575                 /*
1576                  *  Reserve space for MUX and LAP header
1577                  */
1578                 skb_reserve(tx_skb, LMP_MAX_HEADER);
1579
1580                 userdata = tx_skb;
1581         }
1582         ret = irlmp_disconnect_request(self->lsap, userdata);
1583
1584         /* The disconnect is no longer pending */
1585         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1586
1587         return ret;
1588 }
1589 EXPORT_SYMBOL(irttp_disconnect_request);
1590
1591 /*
1592  * Function irttp_disconnect_indication (self, reason)
1593  *
1594  *    Disconnect indication, TSAP disconnected by peer?
1595  *
1596  */
1597 static void irttp_disconnect_indication(void *instance, void *sap,
1598                 LM_REASON reason, struct sk_buff *skb)
1599 {
1600         struct tsap_cb *self;
1601
1602         IRDA_DEBUG(4, "%s()\n", __func__);
1603
1604         self = instance;
1605
1606         IRDA_ASSERT(self != NULL, return;);
1607         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1608
1609         /* Prevent higher layer to send more data */
1610         self->connected = FALSE;
1611
1612         /* Check if client has already tried to close the TSAP */
1613         if (self->close_pend) {
1614                 /* In this case, the higher layer is probably gone. Don't
1615                  * bother it and clean up the remains - Jean II */
1616                 if (skb)
1617                         dev_kfree_skb(skb);
1618                 irttp_close_tsap(self);
1619                 return;
1620         }
1621
1622         /* If we are here, we assume that is the higher layer is still
1623          * waiting for the disconnect notification and able to process it,
1624          * even if he tried to disconnect. Otherwise, it would have already
1625          * attempted to close the tsap and self->close_pend would be TRUE.
1626          * Jean II */
1627
1628         /* No need to notify the client if has already tried to disconnect */
1629         if(self->notify.disconnect_indication)
1630                 self->notify.disconnect_indication(self->notify.instance, self,
1631                                                    reason, skb);
1632         else
1633                 if (skb)
1634                         dev_kfree_skb(skb);
1635 }
1636
1637 /*
1638  * Function irttp_do_data_indication (self, skb)
1639  *
1640  *    Try to deliver reassembled skb to layer above, and requeue it if that
1641  *    for some reason should fail. We mark rx sdu as busy to apply back
1642  *    pressure is necessary.
1643  */
1644 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1645 {
1646         int err;
1647
1648         /* Check if client has already closed the TSAP and gone away */
1649         if (self->close_pend) {
1650                 dev_kfree_skb(skb);
1651                 return;
1652         }
1653
1654         err = self->notify.data_indication(self->notify.instance, self, skb);
1655
1656         /* Usually the layer above will notify that it's input queue is
1657          * starting to get filled by using the flow request, but this may
1658          * be difficult, so it can instead just refuse to eat it and just
1659          * give an error back
1660          */
1661         if (err) {
1662                 IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1663
1664                 /* Make sure we take a break */
1665                 self->rx_sdu_busy = TRUE;
1666
1667                 /* Need to push the header in again */
1668                 skb_push(skb, TTP_HEADER);
1669                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1670
1671                 /* Put skb back on queue */
1672                 skb_queue_head(&self->rx_queue, skb);
1673         }
1674 }
1675
1676 /*
1677  * Function irttp_run_rx_queue (self)
1678  *
1679  *     Check if we have any frames to be transmitted, or if we have any
1680  *     available credit to give away.
1681  */
1682 static void irttp_run_rx_queue(struct tsap_cb *self)
1683 {
1684         struct sk_buff *skb;
1685         int more = 0;
1686
1687         IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1688                    self->send_credit, self->avail_credit, self->remote_credit);
1689
1690         /* Get exclusive access to the rx queue, otherwise don't touch it */
1691         if (irda_lock(&self->rx_queue_lock) == FALSE)
1692                 return;
1693
1694         /*
1695          *  Reassemble all frames in receive queue and deliver them
1696          */
1697         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1698                 /* This bit will tell us if it's the last fragment or not */
1699                 more = skb->data[0] & 0x80;
1700
1701                 /* Remove TTP header */
1702                 skb_pull(skb, TTP_HEADER);
1703
1704                 /* Add the length of the remaining data */
1705                 self->rx_sdu_size += skb->len;
1706
1707                 /*
1708                  * If SAR is disabled, or user has requested no reassembly
1709                  * of received fragments then we just deliver them
1710                  * immediately. This can be requested by clients that
1711                  * implements byte streams without any message boundaries
1712                  */
1713                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1714                         irttp_do_data_indication(self, skb);
1715                         self->rx_sdu_size = 0;
1716
1717                         continue;
1718                 }
1719
1720                 /* Check if this is a fragment, and not the last fragment */
1721                 if (more) {
1722                         /*
1723                          *  Queue the fragment if we still are within the
1724                          *  limits of the maximum size of the rx_sdu
1725                          */
1726                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1727                                 IRDA_DEBUG(4, "%s(), queueing frag\n",
1728                                            __func__);
1729                                 skb_queue_tail(&self->rx_fragments, skb);
1730                         } else {
1731                                 /* Free the part of the SDU that is too big */
1732                                 dev_kfree_skb(skb);
1733                         }
1734                         continue;
1735                 }
1736                 /*
1737                  *  This is the last fragment, so time to reassemble!
1738                  */
1739                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1740                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1741                 {
1742                         /*
1743                          * A little optimizing. Only queue the fragment if
1744                          * there are other fragments. Since if this is the
1745                          * last and only fragment, there is no need to
1746                          * reassemble :-)
1747                          */
1748                         if (!skb_queue_empty(&self->rx_fragments)) {
1749                                 skb_queue_tail(&self->rx_fragments,
1750                                                skb);
1751
1752                                 skb = irttp_reassemble_skb(self);
1753                         }
1754
1755                         /* Now we can deliver the reassembled skb */
1756                         irttp_do_data_indication(self, skb);
1757                 } else {
1758                         IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1759
1760                         /* Free the part of the SDU that is too big */
1761                         dev_kfree_skb(skb);
1762
1763                         /* Deliver only the valid but truncated part of SDU */
1764                         skb = irttp_reassemble_skb(self);
1765
1766                         irttp_do_data_indication(self, skb);
1767                 }
1768                 self->rx_sdu_size = 0;
1769         }
1770
1771         /*
1772          * It's not trivial to keep track of how many credits are available
1773          * by incrementing at each packet, because delivery may fail
1774          * (irttp_do_data_indication() may requeue the frame) and because
1775          * we need to take care of fragmentation.
1776          * We want the other side to send up to initial_credit packets.
1777          * We have some frames in our queues, and we have already allowed it
1778          * to send remote_credit.
1779          * No need to spinlock, write is atomic and self correcting...
1780          * Jean II
1781          */
1782         self->avail_credit = (self->initial_credit -
1783                               (self->remote_credit +
1784                                skb_queue_len(&self->rx_queue) +
1785                                skb_queue_len(&self->rx_fragments)));
1786
1787         /* Do we have too much credits to send to peer ? */
1788         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1789             (self->avail_credit > 0)) {
1790                 /* Send explicit credit frame */
1791                 irttp_give_credit(self);
1792                 /* Note : do *NOT* check if tx_queue is non-empty, that
1793                  * will produce deadlocks. I repeat : send a credit frame
1794                  * even if we have something to send in our Tx queue.
1795                  * If we have credits, it means that our Tx queue is blocked.
1796                  *
1797                  * Let's suppose the peer can't keep up with our Tx. He will
1798                  * flow control us by not sending us any credits, and we
1799                  * will stop Tx and start accumulating credits here.
1800                  * Up to the point where the peer will stop its Tx queue,
1801                  * for lack of credits.
1802                  * Let's assume the peer application is single threaded.
1803                  * It will block on Tx and never consume any Rx buffer.
1804                  * Deadlock. Guaranteed. - Jean II
1805                  */
1806         }
1807
1808         /* Reset lock */
1809         self->rx_queue_lock = 0;
1810 }
1811
1812 #ifdef CONFIG_PROC_FS
1813 struct irttp_iter_state {
1814         int id;
1815 };
1816
1817 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1818 {
1819         struct irttp_iter_state *iter = seq->private;
1820         struct tsap_cb *self;
1821
1822         /* Protect our access to the tsap list */
1823         spin_lock_irq(&irttp->tsaps->hb_spinlock);
1824         iter->id = 0;
1825
1826         for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1827              self != NULL;
1828              self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1829                 if (iter->id == *pos)
1830                         break;
1831                 ++iter->id;
1832         }
1833
1834         return self;
1835 }
1836
1837 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1838 {
1839         struct irttp_iter_state *iter = seq->private;
1840
1841         ++*pos;
1842         ++iter->id;
1843         return (void *) hashbin_get_next(irttp->tsaps);
1844 }
1845
1846 static void irttp_seq_stop(struct seq_file *seq, void *v)
1847 {
1848         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1849 }
1850
1851 static int irttp_seq_show(struct seq_file *seq, void *v)
1852 {
1853         const struct irttp_iter_state *iter = seq->private;
1854         const struct tsap_cb *self = v;
1855
1856         seq_printf(seq, "TSAP %d, ", iter->id);
1857         seq_printf(seq, "stsap_sel: %02x, ",
1858                    self->stsap_sel);
1859         seq_printf(seq, "dtsap_sel: %02x\n",
1860                    self->dtsap_sel);
1861         seq_printf(seq, "  connected: %s, ",
1862                    self->connected? "TRUE":"FALSE");
1863         seq_printf(seq, "avail credit: %d, ",
1864                    self->avail_credit);
1865         seq_printf(seq, "remote credit: %d, ",
1866                    self->remote_credit);
1867         seq_printf(seq, "send credit: %d\n",
1868                    self->send_credit);
1869         seq_printf(seq, "  tx packets: %lu, ",
1870                    self->stats.tx_packets);
1871         seq_printf(seq, "rx packets: %lu, ",
1872                    self->stats.rx_packets);
1873         seq_printf(seq, "tx_queue len: %u ",
1874                    skb_queue_len(&self->tx_queue));
1875         seq_printf(seq, "rx_queue len: %u\n",
1876                    skb_queue_len(&self->rx_queue));
1877         seq_printf(seq, "  tx_sdu_busy: %s, ",
1878                    self->tx_sdu_busy? "TRUE":"FALSE");
1879         seq_printf(seq, "rx_sdu_busy: %s\n",
1880                    self->rx_sdu_busy? "TRUE":"FALSE");
1881         seq_printf(seq, "  max_seg_size: %u, ",
1882                    self->max_seg_size);
1883         seq_printf(seq, "tx_max_sdu_size: %u, ",
1884                    self->tx_max_sdu_size);
1885         seq_printf(seq, "rx_max_sdu_size: %u\n",
1886                    self->rx_max_sdu_size);
1887
1888         seq_printf(seq, "  Used by (%s)\n\n",
1889                    self->notify.name);
1890         return 0;
1891 }
1892
1893 static const struct seq_operations irttp_seq_ops = {
1894         .start  = irttp_seq_start,
1895         .next   = irttp_seq_next,
1896         .stop   = irttp_seq_stop,
1897         .show   = irttp_seq_show,
1898 };
1899
1900 static int irttp_seq_open(struct inode *inode, struct file *file)
1901 {
1902         return seq_open_private(file, &irttp_seq_ops,
1903                         sizeof(struct irttp_iter_state));
1904 }
1905
1906 const struct file_operations irttp_seq_fops = {
1907         .owner          = THIS_MODULE,
1908         .open           = irttp_seq_open,
1909         .read           = seq_read,
1910         .llseek         = seq_lseek,
1911         .release        = seq_release_private,
1912 };
1913
1914 #endif /* PROC_FS */