net/irda/irttp.c

   1 /*********************************************************************
   2  *
   3  * Filename:      irttp.c
   4  * Version:       1.2
   5  * Description:   Tiny Transport Protocol (TTP) implementation
   6  * Status:        Stable
   7  * Author:        Dag Brattli <dagb@cs.uit.no>
   8  * Created at:    Sun Aug 31 20:14:31 1997
   9  * Modified at:   Wed Jan  5 11:31:27 2000
  10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11  *
  12  *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
  13  *     All Rights Reserved.
  14  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
  15  *
  16  *     This program is free software; you can redistribute it and/or
  17  *     modify it under the terms of the GNU General Public License as
  18  *     published by the Free Software Foundation; either version 2 of
  19  *     the License, or (at your option) any later version.
  20  *
  21  *     Neither Dag Brattli nor University of Tromsø admit liability nor
  22  *     provide warranty for any of this software. This material is
  23  *     provided "AS-IS" and at no charge.
  24  *
  25  ********************************************************************/
  26
  27 #include <linux/skbuff.h>
  28 #include <linux/init.h>
  29 #include <linux/seq_file.h>
  30
  31 #include <asm/byteorder.h>
  32 #include <asm/unaligned.h>
  33
  34 #include <net/irda/irda.h>
  35 #include <net/irda/irlap.h>
  36 #include <net/irda/irlmp.h>
  37 #include <net/irda/parameters.h>
  38 #include <net/irda/irttp.h>
  39
  40 static struct irttp_cb *irttp;
  41
  42 static void __irttp_close_tsap(struct tsap_cb *self);
  43
  44 static int irttp_data_indication(void *instance, void *sap,
  45                                  struct sk_buff *skb);
  46 static int irttp_udata_indication(void *instance, void *sap,
  47                                   struct sk_buff *skb);
  48 static void irttp_disconnect_indication(void *instance, void *sap,
  49                                         LM_REASON reason, struct sk_buff *);
  50 static void irttp_connect_indication(void *instance, void *sap,
  51                                      struct qos_info *qos, __u32 max_sdu_size,
  52                                      __u8 header_size, struct sk_buff *skb);
  53 static void irttp_connect_confirm(void *instance, void *sap,
  54                                   struct qos_info *qos, __u32 max_sdu_size,
  55                                   __u8 header_size, struct sk_buff *skb);
  56 static void irttp_run_tx_queue(struct tsap_cb *self);
  57 static void irttp_run_rx_queue(struct tsap_cb *self);
  58
  59 static void irttp_flush_queues(struct tsap_cb *self);
  60 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  61 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  62 static void irttp_todo_expired(unsigned long data);
  63 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  64                                     int get);
  65
  66 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
  67 static void irttp_status_indication(void *instance,
  68                                     LINK_STATUS link, LOCK_STATUS lock);
  69
  70 /* Information for parsing parameters in IrTTP */
  71 static pi_minor_info_t pi_minor_call_table[] = {
  72         { NULL, 0 },                                             /* 0x00 */
  73         { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
  74 };
  75 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  76 static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  77
  78 /************************ GLOBAL PROCEDURES ************************/
  79
  80 /*
  81  * Function irttp_init (void)
  82  *
  83  *    Initialize the IrTTP layer. Called by module initialization code
  84  *
  85  */
  86 int __init irttp_init(void)
  87 {
  88         irttp = kmalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  89         if (irttp == NULL)
  90                 return -ENOMEM;
  91         memset(irttp, 0, sizeof(struct irttp_cb));
  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                            __FUNCTION__);
  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 __exit 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", __FUNCTION__, 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 void irttp_flush_queues(struct tsap_cb *self)
 205 {
 206         struct sk_buff* skb;
 207
 208         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 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", __FUNCTION__,
 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                 memcpy(skb->data+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                    __FUNCTION__, 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", __FUNCTION__);
 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", __FUNCTION__);
 307
 308                 /* Make new segment */
 309                 frag = dev_alloc_skb(self->max_seg_size+self->max_header_size);
 310                 if (!frag)
 311                         return;
 312
 313                 skb_reserve(frag, self->max_header_size);
 314
 315                 /* Copy data from the original skb into this fragment. */
 316                 memcpy(skb_put(frag, self->max_seg_size), skb->data,
 317                        self->max_seg_size);
 318
 319                 /* Insert TTP header, with the more bit set */
 320                 frame = skb_push(frag, TTP_HEADER);
 321                 frame[0] = TTP_MORE;
 322
 323                 /* Hide the copied data from the original skb */
 324                 skb_pull(skb, self->max_seg_size);
 325
 326                 /* Queue fragment */
 327                 skb_queue_tail(&self->tx_queue, frag);
 328         }
 329         /* Queue what is left of the original skb */
 330         IRDA_DEBUG(2, "%s(), queuing last segment\n", __FUNCTION__);
 331
 332         frame = skb_push(skb, TTP_HEADER);
 333         frame[0] = 0x00; /* Clear more bit */
 334
 335         /* Queue fragment */
 336         skb_queue_tail(&self->tx_queue, skb);
 337 }
 338
 339 /*
 340  * Function irttp_param_max_sdu_size (self, param)
 341  *
 342  *    Handle the MaxSduSize parameter in the connect frames, this function
 343  *    will be called both when this parameter needs to be inserted into, and
 344  *    extracted from the connect frames
 345  */
 346 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 347                                     int get)
 348 {
 349         struct tsap_cb *self;
 350
 351         self = (struct tsap_cb *) instance;
 352
 353         IRDA_ASSERT(self != NULL, return -1;);
 354         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 355
 356         if (get)
 357                 param->pv.i = self->tx_max_sdu_size;
 358         else
 359                 self->tx_max_sdu_size = param->pv.i;
 360
 361         IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __FUNCTION__, param->pv.i);
 362
 363         return 0;
 364 }
 365
 366 /*************************** CLIENT CALLS ***************************/
 367 /************************** LMP CALLBACKS **************************/
 368 /* Everything is happily mixed up. Waiting for next clean up - Jean II */
 369
 370 /*
 371  * Function irttp_open_tsap (stsap, notify)
 372  *
 373  *    Create TSAP connection endpoint,
 374  */
 375 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 376 {
 377         struct tsap_cb *self;
 378         struct lsap_cb *lsap;
 379         notify_t ttp_notify;
 380
 381         IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 382
 383         /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 384          * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 385          * JeanII */
 386         if((stsap_sel != LSAP_ANY) &&
 387            ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 388                 IRDA_DEBUG(0, "%s(), invalid tsap!\n", __FUNCTION__);
 389                 return NULL;
 390         }
 391
 392         self = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 393         if (self == NULL) {
 394                 IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __FUNCTION__);
 395                 return NULL;
 396         }
 397         memset(self, 0, sizeof(struct tsap_cb));
 398         spin_lock_init(&self->lock);
 399
 400         /* Initialise todo timer */
 401         init_timer(&self->todo_timer);
 402         self->todo_timer.data     = (unsigned long) self;
 403         self->todo_timer.function = &irttp_todo_expired;
 404
 405         /* Initialize callbacks for IrLMP to use */
 406         irda_notify_init(&ttp_notify);
 407         ttp_notify.connect_confirm = irttp_connect_confirm;
 408         ttp_notify.connect_indication = irttp_connect_indication;
 409         ttp_notify.disconnect_indication = irttp_disconnect_indication;
 410         ttp_notify.data_indication = irttp_data_indication;
 411         ttp_notify.udata_indication = irttp_udata_indication;
 412         ttp_notify.flow_indication = irttp_flow_indication;
 413         if(notify->status_indication != NULL)
 414                 ttp_notify.status_indication = irttp_status_indication;
 415         ttp_notify.instance = self;
 416         strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 417
 418         self->magic = TTP_TSAP_MAGIC;
 419         self->connected = FALSE;
 420
 421         skb_queue_head_init(&self->rx_queue);
 422         skb_queue_head_init(&self->tx_queue);
 423         skb_queue_head_init(&self->rx_fragments);
 424         /*
 425          *  Create LSAP at IrLMP layer
 426          */
 427         lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 428         if (lsap == NULL) {
 429                 IRDA_WARNING("%s: unable to allocate LSAP!!\n", __FUNCTION__);
 430                 return NULL;
 431         }
 432
 433         /*
 434          *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 435          *  will replace it with whatever source selector which is free, so
 436          *  the stsap_sel we have might not be valid anymore
 437          */
 438         self->stsap_sel = lsap->slsap_sel;
 439         IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __FUNCTION__, self->stsap_sel);
 440
 441         self->notify = *notify;
 442         self->lsap = lsap;
 443
 444         hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 445
 446         if (credit > TTP_RX_MAX_CREDIT)
 447                 self->initial_credit = TTP_RX_MAX_CREDIT;
 448         else
 449                 self->initial_credit = credit;
 450
 451         return self;
 452 }
 453 EXPORT_SYMBOL(irttp_open_tsap);
 454
 455 /*
 456  * Function irttp_close (handle)
 457  *
 458  *    Remove an instance of a TSAP. This function should only deal with the
 459  *    deallocation of the TSAP, and resetting of the TSAPs values;
 460  *
 461  */
 462 static void __irttp_close_tsap(struct tsap_cb *self)
 463 {
 464         /* First make sure we're connected. */
 465         IRDA_ASSERT(self != NULL, return;);
 466         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 467
 468         irttp_flush_queues(self);
 469
 470         del_timer(&self->todo_timer);
 471
 472         /* This one won't be cleaned up if we are disconnect_pend + close_pend
 473          * and we receive a disconnect_indication */
 474         if (self->disconnect_skb)
 475                 dev_kfree_skb(self->disconnect_skb);
 476
 477         self->connected = FALSE;
 478         self->magic = ~TTP_TSAP_MAGIC;
 479
 480         kfree(self);
 481 }
 482
 483 /*
 484  * Function irttp_close (self)
 485  *
 486  *    Remove TSAP from list of all TSAPs and then deallocate all resources
 487  *    associated with this TSAP
 488  *
 489  * Note : because we *free* the tsap structure, it is the responsibility
 490  * of the caller to make sure we are called only once and to deal with
 491  * possible race conditions. - Jean II
 492  */
 493 int irttp_close_tsap(struct tsap_cb *self)
 494 {
 495         struct tsap_cb *tsap;
 496
 497         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 498
 499         IRDA_ASSERT(self != NULL, return -1;);
 500         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 501
 502         /* Make sure tsap has been disconnected */
 503         if (self->connected) {
 504                 /* Check if disconnect is not pending */
 505                 if (!test_bit(0, &self->disconnect_pend)) {
 506                         IRDA_WARNING("%s: TSAP still connected!\n",
 507                                      __FUNCTION__);
 508                         irttp_disconnect_request(self, NULL, P_NORMAL);
 509                 }
 510                 self->close_pend = TRUE;
 511                 irttp_start_todo_timer(self, HZ/10);
 512
 513                 return 0; /* Will be back! */
 514         }
 515
 516         tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 517
 518         IRDA_ASSERT(tsap == self, return -1;);
 519
 520         /* Close corresponding LSAP */
 521         if (self->lsap) {
 522                 irlmp_close_lsap(self->lsap);
 523                 self->lsap = NULL;
 524         }
 525
 526         __irttp_close_tsap(self);
 527
 528         return 0;
 529 }
 530 EXPORT_SYMBOL(irttp_close_tsap);
 531
 532 /*
 533  * Function irttp_udata_request (self, skb)
 534  *
 535  *    Send unreliable data on this TSAP
 536  *
 537  */
 538 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 539 {
 540         IRDA_ASSERT(self != NULL, return -1;);
 541         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 542         IRDA_ASSERT(skb != NULL, return -1;);
 543
 544         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 545
 546         /* Check that nothing bad happens */
 547         if ((skb->len == 0) || (!self->connected)) {
 548                 IRDA_DEBUG(1, "%s(), No data, or not connected\n",
 549                            __FUNCTION__);
 550                 goto err;
 551         }
 552
 553         if (skb->len > self->max_seg_size) {
 554                 IRDA_DEBUG(1, "%s(), UData is to large for IrLAP!\n",
 555                            __FUNCTION__);
 556                 goto err;
 557         }
 558
 559         irlmp_udata_request(self->lsap, skb);
 560         self->stats.tx_packets++;
 561
 562         return 0;
 563
 564 err:
 565         dev_kfree_skb(skb);
 566         return -1;
 567 }
 568 EXPORT_SYMBOL(irttp_udata_request);
 569
 570
 571 /*
 572  * Function irttp_data_request (handle, skb)
 573  *
 574  *    Queue frame for transmission. If SAR is enabled, fragement the frame
 575  *    and queue the fragments for transmission
 576  */
 577 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 578 {
 579         __u8 *frame;
 580         int ret;
 581
 582         IRDA_ASSERT(self != NULL, return -1;);
 583         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 584         IRDA_ASSERT(skb != NULL, return -1;);
 585
 586         IRDA_DEBUG(2, "%s() : queue len = %d\n", __FUNCTION__,
 587                    skb_queue_len(&self->tx_queue));
 588
 589         /* Check that nothing bad happens */
 590         if ((skb->len == 0) || (!self->connected)) {
 591                 IRDA_WARNING("%s: No data, or not connected\n", __FUNCTION__);
 592                 ret = -ENOTCONN;
 593                 goto err;
 594         }
 595
 596         /*
 597          *  Check if SAR is disabled, and the frame is larger than what fits
 598          *  inside an IrLAP frame
 599          */
 600         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 601                 IRDA_ERROR("%s: SAR disabled, and data is to large for IrLAP!\n",
 602                            __FUNCTION__);
 603                 ret = -EMSGSIZE;
 604                 goto err;
 605         }
 606
 607         /*
 608          *  Check if SAR is enabled, and the frame is larger than the
 609          *  TxMaxSduSize
 610          */
 611         if ((self->tx_max_sdu_size != 0) &&
 612             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 613             (skb->len > self->tx_max_sdu_size))
 614         {
 615                 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 616                            __FUNCTION__);
 617                 ret = -EMSGSIZE;
 618                 goto err;
 619         }
 620         /*
 621          *  Check if transmit queue is full
 622          */
 623         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 624                 /*
 625                  *  Give it a chance to empty itself
 626                  */
 627                 irttp_run_tx_queue(self);
 628
 629                 /* Drop packet. This error code should trigger the caller
 630                  * to resend the data in the client code - Jean II */
 631                 ret = -ENOBUFS;
 632                 goto err;
 633         }
 634
 635         /* Queue frame, or queue frame segments */
 636         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 637                 /* Queue frame */
 638                 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 639                 frame = skb_push(skb, TTP_HEADER);
 640                 frame[0] = 0x00; /* Clear more bit */
 641
 642                 skb_queue_tail(&self->tx_queue, skb);
 643         } else {
 644                 /*
 645                  *  Fragment the frame, this function will also queue the
 646                  *  fragments, we don't care about the fact the transmit
 647                  *  queue may be overfilled by all the segments for a little
 648                  *  while
 649                  */
 650                 irttp_fragment_skb(self, skb);
 651         }
 652
 653         /* Check if we can accept more data from client */
 654         if ((!self->tx_sdu_busy) &&
 655             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 656                 /* Tx queue filling up, so stop client. */
 657                 if (self->notify.flow_indication) {
 658                         self->notify.flow_indication(self->notify.instance,
 659                                                      self, FLOW_STOP);
 660                 }
 661                 /* self->tx_sdu_busy is the state of the client.
 662                  * Update state after notifying client to avoid
 663                  * race condition with irttp_flow_indication().
 664                  * If the queue empty itself after our test but before
 665                  * we set the flag, we will fix ourselves below in
 666                  * irttp_run_tx_queue().
 667                  * Jean II */
 668                 self->tx_sdu_busy = TRUE;
 669         }
 670
 671         /* Try to make some progress */
 672         irttp_run_tx_queue(self);
 673
 674         return 0;
 675
 676 err:
 677         dev_kfree_skb(skb);
 678         return ret;
 679 }
 680 EXPORT_SYMBOL(irttp_data_request);
 681
 682 /*
 683  * Function irttp_run_tx_queue (self)
 684  *
 685  *    Transmit packets queued for transmission (if possible)
 686  *
 687  */
 688 static void irttp_run_tx_queue(struct tsap_cb *self)
 689 {
 690         struct sk_buff *skb;
 691         unsigned long flags;
 692         int n;
 693
 694         IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 695                    __FUNCTION__,
 696                    self->send_credit, skb_queue_len(&self->tx_queue));
 697
 698         /* Get exclusive access to the tx queue, otherwise don't touch it */
 699         if (irda_lock(&self->tx_queue_lock) == FALSE)
 700                 return;
 701
 702         /* Try to send out frames as long as we have credits
 703          * and as long as LAP is not full. If LAP is full, it will
 704          * poll us through irttp_flow_indication() - Jean II */
 705         while ((self->send_credit > 0) &&
 706                (!irlmp_lap_tx_queue_full(self->lsap)) &&
 707                (skb = skb_dequeue(&self->tx_queue)))
 708         {
 709                 /*
 710                  *  Since we can transmit and receive frames concurrently,
 711                  *  the code below is a critical region and we must assure that
 712                  *  nobody messes with the credits while we update them.
 713                  */
 714                 spin_lock_irqsave(&self->lock, flags);
 715
 716                 n = self->avail_credit;
 717                 self->avail_credit = 0;
 718
 719                 /* Only room for 127 credits in frame */
 720                 if (n > 127) {
 721                         self->avail_credit = n-127;
 722                         n = 127;
 723                 }
 724                 self->remote_credit += n;
 725                 self->send_credit--;
 726
 727                 spin_unlock_irqrestore(&self->lock, flags);
 728
 729                 /*
 730                  *  More bit must be set by the data_request() or fragment()
 731                  *  functions
 732                  */
 733                 skb->data[0] |= (n & 0x7f);
 734
 735                 /* Detach from socket.
 736                  * The current skb has a reference to the socket that sent
 737                  * it (skb->sk). When we pass it to IrLMP, the skb will be
 738                  * stored in in IrLAP (self->wx_list). When we are within
 739                  * IrLAP, we lose the notion of socket, so we should not
 740                  * have a reference to a socket. So, we drop it here.
 741                  *
 742                  * Why does it matter ?
 743                  * When the skb is freed (kfree_skb), if it is associated
 744                  * with a socket, it release buffer space on the socket
 745                  * (through sock_wfree() and sock_def_write_space()).
 746                  * If the socket no longer exist, we may crash. Hard.
 747                  * When we close a socket, we make sure that associated packets
 748                  * in IrTTP are freed. However, we have no way to cancel
 749                  * the packet that we have passed to IrLAP. So, if a packet
 750                  * remains in IrLAP (retry on the link or else) after we
 751                  * close the socket, we are dead !
 752                  * Jean II */
 753                 if (skb->sk != NULL) {
 754                         /* IrSOCK application, IrOBEX, ... */
 755                         skb_orphan(skb);
 756                 }
 757                         /* IrCOMM over IrTTP, IrLAN, ... */
 758
 759                 /* Pass the skb to IrLMP - done */
 760                 irlmp_data_request(self->lsap, skb);
 761                 self->stats.tx_packets++;
 762         }
 763
 764         /* Check if we can accept more frames from client.
 765          * We don't want to wait until the todo timer to do that, and we
 766          * can't use tasklets (grr...), so we are obliged to give control
 767          * to client. That's ok, this test will be true not too often
 768          * (max once per LAP window) and we are called from places
 769          * where we can spend a bit of time doing stuff. - Jean II */
 770         if ((self->tx_sdu_busy) &&
 771             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 772             (!self->close_pend))
 773         {
 774                 if (self->notify.flow_indication)
 775                         self->notify.flow_indication(self->notify.instance,
 776                                                      self, FLOW_START);
 777
 778                 /* self->tx_sdu_busy is the state of the client.
 779                  * We don't really have a race here, but it's always safer
 780                  * to update our state after the client - Jean II */
 781                 self->tx_sdu_busy = FALSE;
 782         }
 783
 784         /* Reset lock */
 785         self->tx_queue_lock = 0;
 786 }
 787
 788 /*
 789  * Function irttp_give_credit (self)
 790  *
 791  *    Send a dataless flowdata TTP-PDU and give available credit to peer
 792  *    TSAP
 793  */
 794 static inline void irttp_give_credit(struct tsap_cb *self)
 795 {
 796         struct sk_buff *tx_skb = NULL;
 797         unsigned long flags;
 798         int n;
 799
 800         IRDA_ASSERT(self != NULL, return;);
 801         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 802
 803         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 804                    __FUNCTION__,
 805                    self->send_credit, self->avail_credit, self->remote_credit);
 806
 807         /* Give credit to peer */
 808         tx_skb = dev_alloc_skb(64);
 809         if (!tx_skb)
 810                 return;
 811
 812         /* Reserve space for LMP, and LAP header */
 813         skb_reserve(tx_skb, self->max_header_size);
 814
 815         /*
 816          *  Since we can transmit and receive frames concurrently,
 817          *  the code below is a critical region and we must assure that
 818          *  nobody messes with the credits while we update them.
 819          */
 820         spin_lock_irqsave(&self->lock, flags);
 821
 822         n = self->avail_credit;
 823         self->avail_credit = 0;
 824
 825         /* Only space for 127 credits in frame */
 826         if (n > 127) {
 827                 self->avail_credit = n - 127;
 828                 n = 127;
 829         }
 830         self->remote_credit += n;
 831
 832         spin_unlock_irqrestore(&self->lock, flags);
 833
 834         skb_put(tx_skb, 1);
 835         tx_skb->data[0] = (__u8) (n & 0x7f);
 836
 837         irlmp_data_request(self->lsap, tx_skb);
 838         self->stats.tx_packets++;
 839 }
 840
 841 /*
 842  * Function irttp_udata_indication (instance, sap, skb)
 843  *
 844  *    Received some unit-data (unreliable)
 845  *
 846  */
 847 static int irttp_udata_indication(void *instance, void *sap,
 848                                   struct sk_buff *skb)
 849 {
 850         struct tsap_cb *self;
 851         int err;
 852
 853         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 854
 855         self = (struct tsap_cb *) instance;
 856
 857         IRDA_ASSERT(self != NULL, return -1;);
 858         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 859         IRDA_ASSERT(skb != NULL, return -1;);
 860
 861         self->stats.rx_packets++;
 862
 863         /* Just pass data to layer above */
 864         if (self->notify.udata_indication) {
 865                 err = self->notify.udata_indication(self->notify.instance,
 866                                                     self,skb);
 867                 /* Same comment as in irttp_do_data_indication() */
 868                 if (!err)
 869                         return 0;
 870         }
 871         /* Either no handler, or handler returns an error */
 872         dev_kfree_skb(skb);
 873
 874         return 0;
 875 }
 876
 877 /*
 878  * Function irttp_data_indication (instance, sap, skb)
 879  *
 880  *    Receive segment from IrLMP.
 881  *
 882  */
 883 static int irttp_data_indication(void *instance, void *sap,
 884                                  struct sk_buff *skb)
 885 {
 886         struct tsap_cb *self;
 887         unsigned long flags;
 888         int n;
 889
 890         self = (struct tsap_cb *) instance;
 891
 892         n = skb->data[0] & 0x7f;     /* Extract the credits */
 893
 894         self->stats.rx_packets++;
 895
 896         /*  Deal with inbound credit
 897          *  Since we can transmit and receive frames concurrently,
 898          *  the code below is a critical region and we must assure that
 899          *  nobody messes with the credits while we update them.
 900          */
 901         spin_lock_irqsave(&self->lock, flags);
 902         self->send_credit += n;
 903         if (skb->len > 1)
 904                 self->remote_credit--;
 905         spin_unlock_irqrestore(&self->lock, flags);
 906
 907         /*
 908          *  Data or dataless packet? Dataless frames contains only the
 909          *  TTP_HEADER.
 910          */
 911         if (skb->len > 1) {
 912                 /*
 913                  *  We don't remove the TTP header, since we must preserve the
 914                  *  more bit, so the defragment routing knows what to do
 915                  */
 916                 skb_queue_tail(&self->rx_queue, skb);
 917         } else {
 918                 /* Dataless flowdata TTP-PDU */
 919                 dev_kfree_skb(skb);
 920         }
 921
 922
 923         /* Push data to the higher layer.
 924          * We do it synchronously because running the todo timer for each
 925          * receive packet would be too much overhead and latency.
 926          * By passing control to the higher layer, we run the risk that
 927          * it may take time or grab a lock. Most often, the higher layer
 928          * will only put packet in a queue.
 929          * Anyway, packets are only dripping through the IrDA, so we can
 930          * have time before the next packet.
 931          * Further, we are run from NET_BH, so the worse that can happen is
 932          * us missing the optimal time to send back the PF bit in LAP.
 933          * Jean II */
 934         irttp_run_rx_queue(self);
 935
 936         /* We now give credits to peer in irttp_run_rx_queue().
 937          * We need to send credit *NOW*, otherwise we are going
 938          * to miss the next Tx window. The todo timer may take
 939          * a while before it's run... - Jean II */
 940
 941         /*
 942          * If the peer device has given us some credits and we didn't have
 943          * anyone from before, then we need to shedule the tx queue.
 944          * We need to do that because our Tx have stopped (so we may not
 945          * get any LAP flow indication) and the user may be stopped as
 946          * well. - Jean II
 947          */
 948         if (self->send_credit == n) {
 949                 /* Restart pushing stuff to LAP */
 950                 irttp_run_tx_queue(self);
 951                 /* Note : we don't want to schedule the todo timer
 952                  * because it has horrible latency. No tasklets
 953                  * because the tasklet API is broken. - Jean II */
 954         }
 955
 956         return 0;
 957 }
 958
 959 /*
 960  * Function irttp_status_indication (self, reason)
 961  *
 962  *    Status_indication, just pass to the higher layer...
 963  *
 964  */
 965 static void irttp_status_indication(void *instance,
 966                                     LINK_STATUS link, LOCK_STATUS lock)
 967 {
 968         struct tsap_cb *self;
 969
 970         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 971
 972         self = (struct tsap_cb *) instance;
 973
 974         IRDA_ASSERT(self != NULL, return;);
 975         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 976
 977         /* Check if client has already closed the TSAP and gone away */
 978         if (self->close_pend)
 979                 return;
 980
 981         /*
 982          *  Inform service user if he has requested it
 983          */
 984         if (self->notify.status_indication != NULL)
 985                 self->notify.status_indication(self->notify.instance,
 986                                                link, lock);
 987         else
 988                 IRDA_DEBUG(2, "%s(), no handler\n", __FUNCTION__);
 989 }
 990
 991 /*
 992  * Function irttp_flow_indication (self, reason)
 993  *
 994  *    Flow_indication : IrLAP tells us to send more data.
 995  *
 996  */
 997 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
 998 {
 999         struct tsap_cb *self;
1000
1001         self = (struct tsap_cb *) instance;
1002
1003         IRDA_ASSERT(self != NULL, return;);
1004         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1005
1006         IRDA_DEBUG(4, "%s(instance=%p)\n", __FUNCTION__, self);
1007
1008         /* We are "polled" directly from LAP, and the LAP want to fill
1009          * its Tx window. We want to do our best to send it data, so that
1010          * we maximise the window. On the other hand, we want to limit the
1011          * amount of work here so that LAP doesn't hang forever waiting
1012          * for packets. - Jean II */
1013
1014         /* Try to send some packets. Currently, LAP calls us every time
1015          * there is one free slot, so we will send only one packet.
1016          * This allow the scheduler to do its round robin - Jean II */
1017         irttp_run_tx_queue(self);
1018
1019         /* Note regarding the interraction with higher layer.
1020          * irttp_run_tx_queue() may call the client when its queue
1021          * start to empty, via notify.flow_indication(). Initially.
1022          * I wanted this to happen in a tasklet, to avoid client
1023          * grabbing the CPU, but we can't use tasklets safely. And timer
1024          * is definitely too slow.
1025          * This will happen only once per LAP window, and usually at
1026          * the third packet (unless window is smaller). LAP is still
1027          * doing mtt and sending first packet so it's sort of OK
1028          * to do that. Jean II */
1029
1030         /* If we need to send disconnect. try to do it now */
1031         if(self->disconnect_pend)
1032                 irttp_start_todo_timer(self, 0);
1033 }
1034
1035 /*
1036  * Function irttp_flow_request (self, command)
1037  *
1038  *    This function could be used by the upper layers to tell IrTTP to stop
1039  *    delivering frames if the receive queues are starting to get full, or
1040  *    to tell IrTTP to start delivering frames again.
1041  */
1042 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1043 {
1044         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1045
1046         IRDA_ASSERT(self != NULL, return;);
1047         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1048
1049         switch (flow) {
1050         case FLOW_STOP:
1051                 IRDA_DEBUG(1, "%s(), flow stop\n", __FUNCTION__);
1052                 self->rx_sdu_busy = TRUE;
1053                 break;
1054         case FLOW_START:
1055                 IRDA_DEBUG(1, "%s(), flow start\n", __FUNCTION__);
1056                 self->rx_sdu_busy = FALSE;
1057
1058                 /* Client say he can accept more data, try to free our
1059                  * queues ASAP - Jean II */
1060                 irttp_run_rx_queue(self);
1061
1062                 break;
1063         default:
1064                 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __FUNCTION__);
1065         }
1066 }
1067 EXPORT_SYMBOL(irttp_flow_request);
1068
1069 /*
1070  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1071  *
1072  *    Try to connect to remote destination TSAP selector
1073  *
1074  */
1075 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1076                           __u32 saddr, __u32 daddr,
1077                           struct qos_info *qos, __u32 max_sdu_size,
1078                           struct sk_buff *userdata)
1079 {
1080         struct sk_buff *tx_skb;
1081         __u8 *frame;
1082         __u8 n;
1083
1084         IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __FUNCTION__, max_sdu_size);
1085
1086         IRDA_ASSERT(self != NULL, return -EBADR;);
1087         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1088
1089         if (self->connected) {
1090                 if(userdata)
1091                         dev_kfree_skb(userdata);
1092                 return -EISCONN;
1093         }
1094
1095         /* Any userdata supplied? */
1096         if (userdata == NULL) {
1097                 tx_skb = dev_alloc_skb(64);
1098                 if (!tx_skb)
1099                         return -ENOMEM;
1100
1101                 /* Reserve space for MUX_CONTROL and LAP header */
1102                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1103         } else {
1104                 tx_skb = userdata;
1105                 /*
1106                  *  Check that the client has reserved enough space for
1107                  *  headers
1108                  */
1109                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1110                         { dev_kfree_skb(userdata); return -1; } );
1111         }
1112
1113         /* Initialize connection parameters */
1114         self->connected = FALSE;
1115         self->avail_credit = 0;
1116         self->rx_max_sdu_size = max_sdu_size;
1117         self->rx_sdu_size = 0;
1118         self->rx_sdu_busy = FALSE;
1119         self->dtsap_sel = dtsap_sel;
1120
1121         n = self->initial_credit;
1122
1123         self->remote_credit = 0;
1124         self->send_credit = 0;
1125
1126         /*
1127          *  Give away max 127 credits for now
1128          */
1129         if (n > 127) {
1130                 self->avail_credit=n-127;
1131                 n = 127;
1132         }
1133
1134         self->remote_credit = n;
1135
1136         /* SAR enabled? */
1137         if (max_sdu_size > 0) {
1138                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1139                         { dev_kfree_skb(tx_skb); return -1; } );
1140
1141                 /* Insert SAR parameters */
1142                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1143
1144                 frame[0] = TTP_PARAMETERS | n;
1145                 frame[1] = 0x04; /* Length */
1146                 frame[2] = 0x01; /* MaxSduSize */
1147                 frame[3] = 0x02; /* Value length */
1148
1149                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1150                               (__u16 *)(frame+4));
1151         } else {
1152                 /* Insert plain TTP header */
1153                 frame = skb_push(tx_skb, TTP_HEADER);
1154
1155                 /* Insert initial credit in frame */
1156                 frame[0] = n & 0x7f;
1157         }
1158
1159         /* Connect with IrLMP. No QoS parameters for now */
1160         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1161                                      tx_skb);
1162 }
1163 EXPORT_SYMBOL(irttp_connect_request);
1164
1165 /*
1166  * Function irttp_connect_confirm (handle, qos, skb)
1167  *
1168  *    Sevice user confirms TSAP connection with peer.
1169  *
1170  */
1171 static void irttp_connect_confirm(void *instance, void *sap,
1172                                   struct qos_info *qos, __u32 max_seg_size,
1173                                   __u8 max_header_size, struct sk_buff *skb)
1174 {
1175         struct tsap_cb *self;
1176         int parameters;
1177         int ret;
1178         __u8 plen;
1179         __u8 n;
1180
1181         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1182
1183         self = (struct tsap_cb *) instance;
1184
1185         IRDA_ASSERT(self != NULL, return;);
1186         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1187         IRDA_ASSERT(skb != NULL, return;);
1188
1189         self->max_seg_size = max_seg_size - TTP_HEADER;
1190         self->max_header_size = max_header_size + TTP_HEADER;
1191
1192         /*
1193          *  Check if we have got some QoS parameters back! This should be the
1194          *  negotiated QoS for the link.
1195          */
1196         if (qos) {
1197                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1198                        qos->baud_rate.bits);
1199                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1200                        qos->baud_rate.value);
1201         }
1202
1203         n = skb->data[0] & 0x7f;
1204
1205         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __FUNCTION__, n);
1206
1207         self->send_credit = n;
1208         self->tx_max_sdu_size = 0;
1209         self->connected = TRUE;
1210
1211         parameters = skb->data[0] & 0x80;
1212
1213         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1214         skb_pull(skb, TTP_HEADER);
1215
1216         if (parameters) {
1217                 plen = skb->data[0];
1218
1219                 ret = irda_param_extract_all(self, skb->data+1,
1220                                              IRDA_MIN(skb->len-1, plen),
1221                                              &param_info);
1222
1223                 /* Any errors in the parameter list? */
1224                 if (ret < 0) {
1225                         IRDA_WARNING("%s: error extracting parameters\n",
1226                                      __FUNCTION__);
1227                         dev_kfree_skb(skb);
1228
1229                         /* Do not accept this connection attempt */
1230                         return;
1231                 }
1232                 /* Remove parameters */
1233                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1234         }
1235
1236         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1237               self->send_credit, self->avail_credit, self->remote_credit);
1238
1239         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __FUNCTION__,
1240                    self->tx_max_sdu_size);
1241
1242         if (self->notify.connect_confirm) {
1243                 self->notify.connect_confirm(self->notify.instance, self, qos,
1244                                              self->tx_max_sdu_size,
1245                                              self->max_header_size, skb);
1246         } else
1247                 dev_kfree_skb(skb);
1248 }
1249
1250 /*
1251  * Function irttp_connect_indication (handle, skb)
1252  *
1253  *    Some other device is connecting to this TSAP
1254  *
1255  */
1256 void irttp_connect_indication(void *instance, void *sap, struct qos_info *qos,
1257                               __u32 max_seg_size, __u8 max_header_size,
1258                               struct sk_buff *skb)
1259 {
1260         struct tsap_cb *self;
1261         struct lsap_cb *lsap;
1262         int parameters;
1263         int ret;
1264         __u8 plen;
1265         __u8 n;
1266
1267         self = (struct tsap_cb *) instance;
1268
1269         IRDA_ASSERT(self != NULL, return;);
1270         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1271         IRDA_ASSERT(skb != NULL, return;);
1272
1273         lsap = (struct lsap_cb *) sap;
1274
1275         self->max_seg_size = max_seg_size - TTP_HEADER;
1276         self->max_header_size = max_header_size+TTP_HEADER;
1277
1278         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __FUNCTION__, self->stsap_sel);
1279
1280         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1281         self->dtsap_sel = lsap->dlsap_sel;
1282
1283         n = skb->data[0] & 0x7f;
1284
1285         self->send_credit = n;
1286         self->tx_max_sdu_size = 0;
1287
1288         parameters = skb->data[0] & 0x80;
1289
1290         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1291         skb_pull(skb, TTP_HEADER);
1292
1293         if (parameters) {
1294                 plen = skb->data[0];
1295
1296                 ret = irda_param_extract_all(self, skb->data+1,
1297                                              IRDA_MIN(skb->len-1, plen),
1298                                              &param_info);
1299
1300                 /* Any errors in the parameter list? */
1301                 if (ret < 0) {
1302                         IRDA_WARNING("%s: error extracting parameters\n",
1303                                      __FUNCTION__);
1304                         dev_kfree_skb(skb);
1305
1306                         /* Do not accept this connection attempt */
1307                         return;
1308                 }
1309
1310                 /* Remove parameters */
1311                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1312         }
1313
1314         if (self->notify.connect_indication) {
1315                 self->notify.connect_indication(self->notify.instance, self,
1316                                                 qos, self->tx_max_sdu_size,
1317                                                 self->max_header_size, skb);
1318         } else
1319                 dev_kfree_skb(skb);
1320 }
1321
1322 /*
1323  * Function irttp_connect_response (handle, userdata)
1324  *
1325  *    Service user is accepting the connection, just pass it down to
1326  *    IrLMP!
1327  *
1328  */
1329 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1330                            struct sk_buff *userdata)
1331 {
1332         struct sk_buff *tx_skb;
1333         __u8 *frame;
1334         int ret;
1335         __u8 n;
1336
1337         IRDA_ASSERT(self != NULL, return -1;);
1338         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1339
1340         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __FUNCTION__,
1341                    self->stsap_sel);
1342
1343         /* Any userdata supplied? */
1344         if (userdata == NULL) {
1345                 tx_skb = dev_alloc_skb(64);
1346                 if (!tx_skb)
1347                         return -ENOMEM;
1348
1349                 /* Reserve space for MUX_CONTROL and LAP header */
1350                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1351         } else {
1352                 tx_skb = userdata;
1353                 /*
1354                  *  Check that the client has reserved enough space for
1355                  *  headers
1356                  */
1357                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1358                         { dev_kfree_skb(userdata); return -1; } );
1359         }
1360
1361         self->avail_credit = 0;
1362         self->remote_credit = 0;
1363         self->rx_max_sdu_size = max_sdu_size;
1364         self->rx_sdu_size = 0;
1365         self->rx_sdu_busy = FALSE;
1366
1367         n = self->initial_credit;
1368
1369         /* Frame has only space for max 127 credits (7 bits) */
1370         if (n > 127) {
1371                 self->avail_credit = n - 127;
1372                 n = 127;
1373         }
1374
1375         self->remote_credit = n;
1376         self->connected = TRUE;
1377
1378         /* SAR enabled? */
1379         if (max_sdu_size > 0) {
1380                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1381                         { dev_kfree_skb(tx_skb); return -1; } );
1382
1383                 /* Insert TTP header with SAR parameters */
1384                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1385
1386                 frame[0] = TTP_PARAMETERS | n;
1387                 frame[1] = 0x04; /* Length */
1388
1389                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1390 /*                                TTP_SAR_HEADER, &param_info) */
1391
1392                 frame[2] = 0x01; /* MaxSduSize */
1393                 frame[3] = 0x02; /* Value length */
1394
1395                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1396                               (__u16 *)(frame+4));
1397         } else {
1398                 /* Insert TTP header */
1399                 frame = skb_push(tx_skb, TTP_HEADER);
1400
1401                 frame[0] = n & 0x7f;
1402         }
1403
1404         ret = irlmp_connect_response(self->lsap, tx_skb);
1405
1406         return ret;
1407 }
1408 EXPORT_SYMBOL(irttp_connect_response);
1409
1410 /*
1411  * Function irttp_dup (self, instance)
1412  *
1413  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1414  *    new TSAP so it can keep listening on the old one.
1415  */
1416 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1417 {
1418         struct tsap_cb *new;
1419         unsigned long flags;
1420
1421         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
1422
1423         /* Protect our access to the old tsap instance */
1424         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1425
1426         /* Find the old instance */
1427         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1428                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __FUNCTION__);
1429                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1430                 return NULL;
1431         }
1432
1433         /* Allocate a new instance */
1434         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1435         if (!new) {
1436                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __FUNCTION__);
1437                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1438                 return NULL;
1439         }
1440         /* Dup */
1441         memcpy(new, orig, sizeof(struct tsap_cb));
1442
1443         /* We don't need the old instance any more */
1444         spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1445
1446         /* Try to dup the LSAP (may fail if we were too slow) */
1447         new->lsap = irlmp_dup(orig->lsap, new);
1448         if (!new->lsap) {
1449                 IRDA_DEBUG(0, "%s(), dup failed!\n", __FUNCTION__);
1450                 kfree(new);
1451                 return NULL;
1452         }
1453
1454         /* Not everything should be copied */
1455         new->notify.instance = instance;
1456         init_timer(&new->todo_timer);
1457
1458         skb_queue_head_init(&new->rx_queue);
1459         skb_queue_head_init(&new->tx_queue);
1460         skb_queue_head_init(&new->rx_fragments);
1461
1462         /* This is locked */
1463         hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1464
1465         return new;
1466 }
1467 EXPORT_SYMBOL(irttp_dup);
1468
1469 /*
1470  * Function irttp_disconnect_request (self)
1471  *
1472  *    Close this connection please! If priority is high, the queued data
1473  *    segments, if any, will be deallocated first
1474  *
1475  */
1476 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1477                              int priority)
1478 {
1479         int ret;
1480
1481         IRDA_ASSERT(self != NULL, return -1;);
1482         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1483
1484         /* Already disconnected? */
1485         if (!self->connected) {
1486                 IRDA_DEBUG(4, "%s(), already disconnected!\n", __FUNCTION__);
1487                 if (userdata)
1488                         dev_kfree_skb(userdata);
1489                 return -1;
1490         }
1491
1492         /* Disconnect already pending ?
1493          * We need to use an atomic operation to prevent reentry. This
1494          * function may be called from various context, like user, timer
1495          * for following a disconnect_indication() (i.e. net_bh).
1496          * Jean II */
1497         if(test_and_set_bit(0, &self->disconnect_pend)) {
1498                 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1499                            __FUNCTION__);
1500                 if (userdata)
1501                         dev_kfree_skb(userdata);
1502
1503                 /* Try to make some progress */
1504                 irttp_run_tx_queue(self);
1505                 return -1;
1506         }
1507
1508         /*
1509          *  Check if there is still data segments in the transmit queue
1510          */
1511         if (!skb_queue_empty(&self->tx_queue)) {
1512                 if (priority == P_HIGH) {
1513                         /*
1514                          *  No need to send the queued data, if we are
1515                          *  disconnecting right now since the data will
1516                          *  not have any usable connection to be sent on
1517                          */
1518                         IRDA_DEBUG(1, "%s(): High priority!!()\n", __FUNCTION__);
1519                         irttp_flush_queues(self);
1520                 } else if (priority == P_NORMAL) {
1521                         /*
1522                          *  Must delay disconnect until after all data segments
1523                          *  have been sent and the tx_queue is empty
1524                          */
1525                         /* We'll reuse this one later for the disconnect */
1526                         self->disconnect_skb = userdata;  /* May be NULL */
1527
1528                         irttp_run_tx_queue(self);
1529
1530                         irttp_start_todo_timer(self, HZ/10);
1531                         return -1;
1532                 }
1533         }
1534         /* Note : we don't need to check if self->rx_queue is full and the
1535          * state of self->rx_sdu_busy because the disconnect response will
1536          * be sent at the LMP level (so even if the peer has its Tx queue
1537          * full of data). - Jean II */
1538
1539         IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __FUNCTION__);
1540         self->connected = FALSE;
1541
1542         if (!userdata) {
1543                 struct sk_buff *tx_skb;
1544                 tx_skb = dev_alloc_skb(64);
1545                 if (!tx_skb)
1546                         return -ENOMEM;
1547
1548                 /*
1549                  *  Reserve space for MUX and LAP header
1550                  */
1551                 skb_reserve(tx_skb, TTP_MAX_HEADER);
1552
1553                 userdata = tx_skb;
1554         }
1555         ret = irlmp_disconnect_request(self->lsap, userdata);
1556
1557         /* The disconnect is no longer pending */
1558         clear_bit(0, &self->disconnect_pend);   /* FALSE */
1559
1560         return ret;
1561 }
1562 EXPORT_SYMBOL(irttp_disconnect_request);
1563
1564 /*
1565  * Function irttp_disconnect_indication (self, reason)
1566  *
1567  *    Disconnect indication, TSAP disconnected by peer?
1568  *
1569  */
1570 void irttp_disconnect_indication(void *instance, void *sap, LM_REASON reason,
1571                                  struct sk_buff *skb)
1572 {
1573         struct tsap_cb *self;
1574
1575         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1576
1577         self = (struct tsap_cb *) instance;
1578
1579         IRDA_ASSERT(self != NULL, return;);
1580         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1581
1582         /* Prevent higher layer to send more data */
1583         self->connected = FALSE;
1584
1585         /* Check if client has already tried to close the TSAP */
1586         if (self->close_pend) {
1587                 /* In this case, the higher layer is probably gone. Don't
1588                  * bother it and clean up the remains - Jean II */
1589                 if (skb)
1590                         dev_kfree_skb(skb);
1591                 irttp_close_tsap(self);
1592                 return;
1593         }
1594
1595         /* If we are here, we assume that is the higher layer is still
1596          * waiting for the disconnect notification and able to process it,
1597          * even if he tried to disconnect. Otherwise, it would have already
1598          * attempted to close the tsap and self->close_pend would be TRUE.
1599          * Jean II */
1600
1601         /* No need to notify the client if has already tried to disconnect */
1602         if(self->notify.disconnect_indication)
1603                 self->notify.disconnect_indication(self->notify.instance, self,
1604                                                    reason, skb);
1605         else
1606                 if (skb)
1607                         dev_kfree_skb(skb);
1608 }
1609
1610 /*
1611  * Function irttp_do_data_indication (self, skb)
1612  *
1613  *    Try to deliver reassembled skb to layer above, and requeue it if that
1614  *    for some reason should fail. We mark rx sdu as busy to apply back
1615  *    pressure is necessary.
1616  */
1617 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1618 {
1619         int err;
1620
1621         /* Check if client has already closed the TSAP and gone away */
1622         if (self->close_pend) {
1623                 dev_kfree_skb(skb);
1624                 return;
1625         }
1626
1627         err = self->notify.data_indication(self->notify.instance, self, skb);
1628
1629         /* Usually the layer above will notify that it's input queue is
1630          * starting to get filled by using the flow request, but this may
1631          * be difficult, so it can instead just refuse to eat it and just
1632          * give an error back
1633          */
1634         if (err) {
1635                 IRDA_DEBUG(0, "%s() requeueing skb!\n", __FUNCTION__);
1636
1637                 /* Make sure we take a break */
1638                 self->rx_sdu_busy = TRUE;
1639
1640                 /* Need to push the header in again */
1641                 skb_push(skb, TTP_HEADER);
1642                 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1643
1644                 /* Put skb back on queue */
1645                 skb_queue_head(&self->rx_queue, skb);
1646         }
1647 }
1648
1649 /*
1650  * Function irttp_run_rx_queue (self)
1651  *
1652  *     Check if we have any frames to be transmitted, or if we have any
1653  *     available credit to give away.
1654  */
1655 void irttp_run_rx_queue(struct tsap_cb *self)
1656 {
1657         struct sk_buff *skb;
1658         int more = 0;
1659
1660         IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __FUNCTION__,
1661                    self->send_credit, self->avail_credit, self->remote_credit);
1662
1663         /* Get exclusive access to the rx queue, otherwise don't touch it */
1664         if (irda_lock(&self->rx_queue_lock) == FALSE)
1665                 return;
1666
1667         /*
1668          *  Reassemble all frames in receive queue and deliver them
1669          */
1670         while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1671                 /* This bit will tell us if it's the last fragment or not */
1672                 more = skb->data[0] & 0x80;
1673
1674                 /* Remove TTP header */
1675                 skb_pull(skb, TTP_HEADER);
1676
1677                 /* Add the length of the remaining data */
1678                 self->rx_sdu_size += skb->len;
1679
1680                 /*
1681                  * If SAR is disabled, or user has requested no reassembly
1682                  * of received fragments then we just deliver them
1683                  * immediately. This can be requested by clients that
1684                  * implements byte streams without any message boundaries
1685                  */
1686                 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1687                         irttp_do_data_indication(self, skb);
1688                         self->rx_sdu_size = 0;
1689
1690                         continue;
1691                 }
1692
1693                 /* Check if this is a fragment, and not the last fragment */
1694                 if (more) {
1695                         /*
1696                          *  Queue the fragment if we still are within the
1697                          *  limits of the maximum size of the rx_sdu
1698                          */
1699                         if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1700                                 IRDA_DEBUG(4, "%s(), queueing frag\n",
1701                                            __FUNCTION__);
1702                                 skb_queue_tail(&self->rx_fragments, skb);
1703                         } else {
1704                                 /* Free the part of the SDU that is too big */
1705                                 dev_kfree_skb(skb);
1706                         }
1707                         continue;
1708                 }
1709                 /*
1710                  *  This is the last fragment, so time to reassemble!
1711                  */
1712                 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1713                     (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1714                 {
1715                         /*
1716                          * A little optimizing. Only queue the fragment if
1717                          * there are other fragments. Since if this is the
1718                          * last and only fragment, there is no need to
1719                          * reassemble :-)
1720                          */
1721                         if (!skb_queue_empty(&self->rx_fragments)) {
1722                                 skb_queue_tail(&self->rx_fragments,
1723                                                skb);
1724
1725                                 skb = irttp_reassemble_skb(self);
1726                         }
1727
1728                         /* Now we can deliver the reassembled skb */
1729                         irttp_do_data_indication(self, skb);
1730                 } else {
1731                         IRDA_DEBUG(1, "%s(), Truncated frame\n", __FUNCTION__);
1732
1733                         /* Free the part of the SDU that is too big */
1734                         dev_kfree_skb(skb);
1735
1736                         /* Deliver only the valid but truncated part of SDU */
1737                         skb = irttp_reassemble_skb(self);
1738
1739                         irttp_do_data_indication(self, skb);
1740                 }
1741                 self->rx_sdu_size = 0;
1742         }
1743
1744         /*
1745          * It's not trivial to keep track of how many credits are available
1746          * by incrementing at each packet, because delivery may fail
1747          * (irttp_do_data_indication() may requeue the frame) and because
1748          * we need to take care of fragmentation.
1749          * We want the other side to send up to initial_credit packets.
1750          * We have some frames in our queues, and we have already allowed it
1751          * to send remote_credit.
1752          * No need to spinlock, write is atomic and self correcting...
1753          * Jean II
1754          */
1755         self->avail_credit = (self->initial_credit -
1756                               (self->remote_credit +
1757                                skb_queue_len(&self->rx_queue) +
1758                                skb_queue_len(&self->rx_fragments)));
1759
1760         /* Do we have too much credits to send to peer ? */
1761         if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1762             (self->avail_credit > 0)) {
1763                 /* Send explicit credit frame */
1764                 irttp_give_credit(self);
1765                 /* Note : do *NOT* check if tx_queue is non-empty, that
1766                  * will produce deadlocks. I repeat : send a credit frame
1767                  * even if we have something to send in our Tx queue.
1768                  * If we have credits, it means that our Tx queue is blocked.
1769                  *
1770                  * Let's suppose the peer can't keep up with our Tx. He will
1771                  * flow control us by not sending us any credits, and we
1772                  * will stop Tx and start accumulating credits here.
1773                  * Up to the point where the peer will stop its Tx queue,
1774                  * for lack of credits.
1775                  * Let's assume the peer application is single threaded.
1776                  * It will block on Tx and never consume any Rx buffer.
1777                  * Deadlock. Guaranteed. - Jean II
1778                  */
1779         }
1780
1781         /* Reset lock */
1782         self->rx_queue_lock = 0;
1783 }
1784
1785 #ifdef CONFIG_PROC_FS
1786 struct irttp_iter_state {
1787         int id;
1788 };
1789
1790 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1791 {
1792         struct irttp_iter_state *iter = seq->private;
1793         struct tsap_cb *self;
1794
1795         /* Protect our access to the tsap list */
1796         spin_lock_irq(&irttp->tsaps->hb_spinlock);
1797         iter->id = 0;
1798
1799         for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1800              self != NULL;
1801              self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1802                 if (iter->id == *pos)
1803                         break;
1804                 ++iter->id;
1805         }
1806
1807         return self;
1808 }
1809
1810 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1811 {
1812         struct irttp_iter_state *iter = seq->private;
1813
1814         ++*pos;
1815         ++iter->id;
1816         return (void *) hashbin_get_next(irttp->tsaps);
1817 }
1818
1819 static void irttp_seq_stop(struct seq_file *seq, void *v)
1820 {
1821         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1822 }
1823
1824 static int irttp_seq_show(struct seq_file *seq, void *v)
1825 {
1826         const struct irttp_iter_state *iter = seq->private;
1827         const struct tsap_cb *self = v;
1828
1829         seq_printf(seq, "TSAP %d, ", iter->id);
1830         seq_printf(seq, "stsap_sel: %02x, ",
1831                    self->stsap_sel);
1832         seq_printf(seq, "dtsap_sel: %02x\n",
1833                    self->dtsap_sel);
1834         seq_printf(seq, "  connected: %s, ",
1835                    self->connected? "TRUE":"FALSE");
1836         seq_printf(seq, "avail credit: %d, ",
1837                    self->avail_credit);
1838         seq_printf(seq, "remote credit: %d, ",
1839                    self->remote_credit);
1840         seq_printf(seq, "send credit: %d\n",
1841                    self->send_credit);
1842         seq_printf(seq, "  tx packets: %ld, ",
1843                    self->stats.tx_packets);
1844         seq_printf(seq, "rx packets: %ld, ",
1845                    self->stats.rx_packets);
1846         seq_printf(seq, "tx_queue len: %d ",
1847                    skb_queue_len(&self->tx_queue));
1848         seq_printf(seq, "rx_queue len: %d\n",
1849                    skb_queue_len(&self->rx_queue));
1850         seq_printf(seq, "  tx_sdu_busy: %s, ",
1851                    self->tx_sdu_busy? "TRUE":"FALSE");
1852         seq_printf(seq, "rx_sdu_busy: %s\n",
1853                    self->rx_sdu_busy? "TRUE":"FALSE");
1854         seq_printf(seq, "  max_seg_size: %d, ",
1855                    self->max_seg_size);
1856         seq_printf(seq, "tx_max_sdu_size: %d, ",
1857                    self->tx_max_sdu_size);
1858         seq_printf(seq, "rx_max_sdu_size: %d\n",
1859                    self->rx_max_sdu_size);
1860
1861         seq_printf(seq, "  Used by (%s)\n\n",
1862                    self->notify.name);
1863         return 0;
1864 }
1865
1866 static struct seq_operations irttp_seq_ops = {
1867         .start  = irttp_seq_start,
1868         .next   = irttp_seq_next,
1869         .stop   = irttp_seq_stop,
1870         .show   = irttp_seq_show,
1871 };
1872
1873 static int irttp_seq_open(struct inode *inode, struct file *file)
1874 {
1875         struct seq_file *seq;
1876         int rc = -ENOMEM;
1877         struct irttp_iter_state *s;
1878
1879         s = kmalloc(sizeof(*s), GFP_KERNEL);
1880         if (!s)
1881                 goto out;
1882
1883         rc = seq_open(file, &irttp_seq_ops);
1884         if (rc)
1885                 goto out_kfree;
1886
1887         seq          = file->private_data;
1888         seq->private = s;
1889         memset(s, 0, sizeof(*s));
1890 out:
1891         return rc;
1892 out_kfree:
1893         kfree(s);
1894         goto out;
1895 }
1896
1897 struct file_operations irttp_seq_fops = {
1898         .owner          = THIS_MODULE,
1899         .open           = irttp_seq_open,
1900         .read           = seq_read,
1901         .llseek         = seq_lseek,
1902         .release        = seq_release_private,
1903 };
1904
1905 #endif /* PROC_FS */