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