linux/net/irda/irttp.c
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   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
  43static struct irttp_cb *irttp;
  44
  45static void __irttp_close_tsap(struct tsap_cb *self);
  46
  47static int irttp_data_indication(void *instance, void *sap,
  48                                 struct sk_buff *skb);
  49static int irttp_udata_indication(void *instance, void *sap,
  50                                  struct sk_buff *skb);
  51static void irttp_disconnect_indication(void *instance, void *sap,
  52                                        LM_REASON reason, struct sk_buff *);
  53static 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);
  56static 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);
  59static void irttp_run_tx_queue(struct tsap_cb *self);
  60static void irttp_run_rx_queue(struct tsap_cb *self);
  61
  62static void irttp_flush_queues(struct tsap_cb *self);
  63static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
  64static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
  65static void irttp_todo_expired(unsigned long data);
  66static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
  67                                    int get);
  68
  69static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
  70static void irttp_status_indication(void *instance,
  71                                    LINK_STATUS link, LOCK_STATUS lock);
  72
  73/* Information for parsing parameters in IrTTP */
  74static 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};
  78static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
  79static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
  80
  81/************************ GLOBAL PROCEDURES ************************/
  82
  83/*
  84 * Function irttp_init (void)
  85 *
  86 *    Initialize the IrTTP layer. Called by module initialization code
  87 *
  88 */
  89int __init irttp_init(void)
  90{
  91        irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
  92        if (irttp == NULL)
  93                return -ENOMEM;
  94
  95        irttp->magic = TTP_MAGIC;
  96
  97        irttp->tsaps = hashbin_new(HB_LOCK);
  98        if (!irttp->tsaps) {
  99                IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
 100                           __func__);
 101                kfree(irttp);
 102                return -ENOMEM;
 103        }
 104
 105        return 0;
 106}
 107
 108/*
 109 * Function irttp_cleanup (void)
 110 *
 111 *    Called by module destruction/cleanup code
 112 *
 113 */
 114void irttp_cleanup(void)
 115{
 116        /* Check for main structure */
 117        IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
 118
 119        /*
 120         *  Delete hashbin and close all TSAP instances in it
 121         */
 122        hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
 123
 124        irttp->magic = 0;
 125
 126        /* De-allocate main structure */
 127        kfree(irttp);
 128
 129        irttp = NULL;
 130}
 131
 132/*************************** SUBROUTINES ***************************/
 133
 134/*
 135 * Function irttp_start_todo_timer (self, timeout)
 136 *
 137 *    Start todo timer.
 138 *
 139 * Made it more effient and unsensitive to race conditions - Jean II
 140 */
 141static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
 142{
 143        /* Set new value for timer */
 144        mod_timer(&self->todo_timer, jiffies + timeout);
 145}
 146
 147/*
 148 * Function irttp_todo_expired (data)
 149 *
 150 *    Todo timer has expired!
 151 *
 152 * One of the restriction of the timer is that it is run only on the timer
 153 * interrupt which run every 10ms. This mean that even if you set the timer
 154 * with a delay of 0, it may take up to 10ms before it's run.
 155 * So, to minimise latency and keep cache fresh, we try to avoid using
 156 * it as much as possible.
 157 * Note : we can't use tasklets, because they can't be asynchronously
 158 * killed (need user context), and we can't guarantee that here...
 159 * Jean II
 160 */
 161static void irttp_todo_expired(unsigned long data)
 162{
 163        struct tsap_cb *self = (struct tsap_cb *) data;
 164
 165        /* Check that we still exist */
 166        if (!self || self->magic != TTP_TSAP_MAGIC)
 167                return;
 168
 169        IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
 170
 171        /* Try to make some progress, especially on Tx side - Jean II */
 172        irttp_run_rx_queue(self);
 173        irttp_run_tx_queue(self);
 174
 175        /* Check if time for disconnect */
 176        if (test_bit(0, &self->disconnect_pend)) {
 177                /* Check if it's possible to disconnect yet */
 178                if (skb_queue_empty(&self->tx_queue)) {
 179                        /* Make sure disconnect is not pending anymore */
 180                        clear_bit(0, &self->disconnect_pend);   /* FALSE */
 181
 182                        /* Note : self->disconnect_skb may be NULL */
 183                        irttp_disconnect_request(self, self->disconnect_skb,
 184                                                 P_NORMAL);
 185                        self->disconnect_skb = NULL;
 186                } else {
 187                        /* Try again later */
 188                        irttp_start_todo_timer(self, HZ/10);
 189
 190                        /* No reason to try and close now */
 191                        return;
 192                }
 193        }
 194
 195        /* Check if it's closing time */
 196        if (self->close_pend)
 197                /* Finish cleanup */
 198                irttp_close_tsap(self);
 199}
 200
 201/*
 202 * Function irttp_flush_queues (self)
 203 *
 204 *     Flushes (removes all frames) in transitt-buffer (tx_list)
 205 */
 206static void irttp_flush_queues(struct tsap_cb *self)
 207{
 208        struct sk_buff* skb;
 209
 210        IRDA_DEBUG(4, "%s()\n", __func__);
 211
 212        IRDA_ASSERT(self != NULL, return;);
 213        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 214
 215        /* Deallocate frames waiting to be sent */
 216        while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
 217                dev_kfree_skb(skb);
 218
 219        /* Deallocate received frames */
 220        while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
 221                dev_kfree_skb(skb);
 222
 223        /* Deallocate received fragments */
 224        while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
 225                dev_kfree_skb(skb);
 226}
 227
 228/*
 229 * Function irttp_reassemble (self)
 230 *
 231 *    Makes a new (continuous) skb of all the fragments in the fragment
 232 *    queue
 233 *
 234 */
 235static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
 236{
 237        struct sk_buff *skb, *frag;
 238        int n = 0;  /* Fragment index */
 239
 240        IRDA_ASSERT(self != NULL, return NULL;);
 241        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
 242
 243        IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __func__,
 244                   self->rx_sdu_size);
 245
 246        skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
 247        if (!skb)
 248                return NULL;
 249
 250        /*
 251         * Need to reserve space for TTP header in case this skb needs to
 252         * be requeued in case delivery failes
 253         */
 254        skb_reserve(skb, TTP_HEADER);
 255        skb_put(skb, self->rx_sdu_size);
 256
 257        /*
 258         *  Copy all fragments to a new buffer
 259         */
 260        while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
 261                skb_copy_to_linear_data_offset(skb, n, frag->data, frag->len);
 262                n += frag->len;
 263
 264                dev_kfree_skb(frag);
 265        }
 266
 267        IRDA_DEBUG(2,
 268                   "%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
 269                   __func__, n, self->rx_sdu_size, self->rx_max_sdu_size);
 270        /* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
 271         * by summing the size of all fragments, so we should always
 272         * have n == self->rx_sdu_size, except in cases where we
 273         * droped the last fragment (when self->rx_sdu_size exceed
 274         * self->rx_max_sdu_size), where n < self->rx_sdu_size.
 275         * Jean II */
 276        IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
 277
 278        /* Set the new length */
 279        skb_trim(skb, n);
 280
 281        self->rx_sdu_size = 0;
 282
 283        return skb;
 284}
 285
 286/*
 287 * Function irttp_fragment_skb (skb)
 288 *
 289 *    Fragments a frame and queues all the fragments for transmission
 290 *
 291 */
 292static inline void irttp_fragment_skb(struct tsap_cb *self,
 293                                      struct sk_buff *skb)
 294{
 295        struct sk_buff *frag;
 296        __u8 *frame;
 297
 298        IRDA_DEBUG(2, "%s()\n", __func__);
 299
 300        IRDA_ASSERT(self != NULL, return;);
 301        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 302        IRDA_ASSERT(skb != NULL, return;);
 303
 304        /*
 305         *  Split frame into a number of segments
 306         */
 307        while (skb->len > self->max_seg_size) {
 308                IRDA_DEBUG(2, "%s(), fragmenting ...\n", __func__);
 309
 310                /* Make new segment */
 311                frag = alloc_skb(self->max_seg_size+self->max_header_size,
 312                                 GFP_ATOMIC);
 313                if (!frag)
 314                        return;
 315
 316                skb_reserve(frag, self->max_header_size);
 317
 318                /* Copy data from the original skb into this fragment. */
 319                skb_copy_from_linear_data(skb, skb_put(frag, self->max_seg_size),
 320                              self->max_seg_size);
 321
 322                /* Insert TTP header, with the more bit set */
 323                frame = skb_push(frag, TTP_HEADER);
 324                frame[0] = TTP_MORE;
 325
 326                /* Hide the copied data from the original skb */
 327                skb_pull(skb, self->max_seg_size);
 328
 329                /* Queue fragment */
 330                skb_queue_tail(&self->tx_queue, frag);
 331        }
 332        /* Queue what is left of the original skb */
 333        IRDA_DEBUG(2, "%s(), queuing last segment\n", __func__);
 334
 335        frame = skb_push(skb, TTP_HEADER);
 336        frame[0] = 0x00; /* Clear more bit */
 337
 338        /* Queue fragment */
 339        skb_queue_tail(&self->tx_queue, skb);
 340}
 341
 342/*
 343 * Function irttp_param_max_sdu_size (self, param)
 344 *
 345 *    Handle the MaxSduSize parameter in the connect frames, this function
 346 *    will be called both when this parameter needs to be inserted into, and
 347 *    extracted from the connect frames
 348 */
 349static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
 350                                    int get)
 351{
 352        struct tsap_cb *self;
 353
 354        self = instance;
 355
 356        IRDA_ASSERT(self != NULL, return -1;);
 357        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 358
 359        if (get)
 360                param->pv.i = self->tx_max_sdu_size;
 361        else
 362                self->tx_max_sdu_size = param->pv.i;
 363
 364        IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __func__, param->pv.i);
 365
 366        return 0;
 367}
 368
 369/*************************** CLIENT CALLS ***************************/
 370/************************** LMP CALLBACKS **************************/
 371/* Everything is happily mixed up. Waiting for next clean up - Jean II */
 372
 373/*
 374 * Initialization, that has to be done on new tsap
 375 * instance allocation and on duplication
 376 */
 377static void irttp_init_tsap(struct tsap_cb *tsap)
 378{
 379        spin_lock_init(&tsap->lock);
 380        init_timer(&tsap->todo_timer);
 381
 382        skb_queue_head_init(&tsap->rx_queue);
 383        skb_queue_head_init(&tsap->tx_queue);
 384        skb_queue_head_init(&tsap->rx_fragments);
 385}
 386
 387/*
 388 * Function irttp_open_tsap (stsap, notify)
 389 *
 390 *    Create TSAP connection endpoint,
 391 */
 392struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
 393{
 394        struct tsap_cb *self;
 395        struct lsap_cb *lsap;
 396        notify_t ttp_notify;
 397
 398        IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
 399
 400        /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
 401         * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
 402         * JeanII */
 403        if((stsap_sel != LSAP_ANY) &&
 404           ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
 405                IRDA_DEBUG(0, "%s(), invalid tsap!\n", __func__);
 406                return NULL;
 407        }
 408
 409        self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
 410        if (self == NULL) {
 411                IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __func__);
 412                return NULL;
 413        }
 414
 415        /* Initialize internal objects */
 416        irttp_init_tsap(self);
 417
 418        /* Initialise todo timer */
 419        self->todo_timer.data     = (unsigned long) self;
 420        self->todo_timer.function = &irttp_todo_expired;
 421
 422        /* Initialize callbacks for IrLMP to use */
 423        irda_notify_init(&ttp_notify);
 424        ttp_notify.connect_confirm = irttp_connect_confirm;
 425        ttp_notify.connect_indication = irttp_connect_indication;
 426        ttp_notify.disconnect_indication = irttp_disconnect_indication;
 427        ttp_notify.data_indication = irttp_data_indication;
 428        ttp_notify.udata_indication = irttp_udata_indication;
 429        ttp_notify.flow_indication = irttp_flow_indication;
 430        if(notify->status_indication != NULL)
 431                ttp_notify.status_indication = irttp_status_indication;
 432        ttp_notify.instance = self;
 433        strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
 434
 435        self->magic = TTP_TSAP_MAGIC;
 436        self->connected = FALSE;
 437
 438        /*
 439         *  Create LSAP at IrLMP layer
 440         */
 441        lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
 442        if (lsap == NULL) {
 443                IRDA_WARNING("%s: unable to allocate LSAP!!\n", __func__);
 444                return NULL;
 445        }
 446
 447        /*
 448         *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 449         *  will replace it with whatever source selector which is free, so
 450         *  the stsap_sel we have might not be valid anymore
 451         */
 452        self->stsap_sel = lsap->slsap_sel;
 453        IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
 454
 455        self->notify = *notify;
 456        self->lsap = lsap;
 457
 458        hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 459
 460        if (credit > TTP_RX_MAX_CREDIT)
 461                self->initial_credit = TTP_RX_MAX_CREDIT;
 462        else
 463                self->initial_credit = credit;
 464
 465        return self;
 466}
 467EXPORT_SYMBOL(irttp_open_tsap);
 468
 469/*
 470 * Function irttp_close (handle)
 471 *
 472 *    Remove an instance of a TSAP. This function should only deal with the
 473 *    deallocation of the TSAP, and resetting of the TSAPs values;
 474 *
 475 */
 476static void __irttp_close_tsap(struct tsap_cb *self)
 477{
 478        /* First make sure we're connected. */
 479        IRDA_ASSERT(self != NULL, return;);
 480        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 481
 482        irttp_flush_queues(self);
 483
 484        del_timer(&self->todo_timer);
 485
 486        /* This one won't be cleaned up if we are disconnect_pend + close_pend
 487         * and we receive a disconnect_indication */
 488        if (self->disconnect_skb)
 489                dev_kfree_skb(self->disconnect_skb);
 490
 491        self->connected = FALSE;
 492        self->magic = ~TTP_TSAP_MAGIC;
 493
 494        kfree(self);
 495}
 496
 497/*
 498 * Function irttp_close (self)
 499 *
 500 *    Remove TSAP from list of all TSAPs and then deallocate all resources
 501 *    associated with this TSAP
 502 *
 503 * Note : because we *free* the tsap structure, it is the responsibility
 504 * of the caller to make sure we are called only once and to deal with
 505 * possible race conditions. - Jean II
 506 */
 507int irttp_close_tsap(struct tsap_cb *self)
 508{
 509        struct tsap_cb *tsap;
 510
 511        IRDA_DEBUG(4, "%s()\n", __func__);
 512
 513        IRDA_ASSERT(self != NULL, return -1;);
 514        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 515
 516        /* Make sure tsap has been disconnected */
 517        if (self->connected) {
 518                /* Check if disconnect is not pending */
 519                if (!test_bit(0, &self->disconnect_pend)) {
 520                        IRDA_WARNING("%s: TSAP still connected!\n",
 521                                     __func__);
 522                        irttp_disconnect_request(self, NULL, P_NORMAL);
 523                }
 524                self->close_pend = TRUE;
 525                irttp_start_todo_timer(self, HZ/10);
 526
 527                return 0; /* Will be back! */
 528        }
 529
 530        tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 531
 532        IRDA_ASSERT(tsap == self, return -1;);
 533
 534        /* Close corresponding LSAP */
 535        if (self->lsap) {
 536                irlmp_close_lsap(self->lsap);
 537                self->lsap = NULL;
 538        }
 539
 540        __irttp_close_tsap(self);
 541
 542        return 0;
 543}
 544EXPORT_SYMBOL(irttp_close_tsap);
 545
 546/*
 547 * Function irttp_udata_request (self, skb)
 548 *
 549 *    Send unreliable data on this TSAP
 550 *
 551 */
 552int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 553{
 554        int ret;
 555
 556        IRDA_ASSERT(self != NULL, return -1;);
 557        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 558        IRDA_ASSERT(skb != NULL, return -1;);
 559
 560        IRDA_DEBUG(4, "%s()\n", __func__);
 561
 562        /* Take shortcut on zero byte packets */
 563        if (skb->len == 0) {
 564                ret = 0;
 565                goto err;
 566        }
 567
 568        /* Check that nothing bad happens */
 569        if (!self->connected) {
 570                IRDA_WARNING("%s(), Not connected\n", __func__);
 571                ret = -ENOTCONN;
 572                goto err;
 573        }
 574
 575        if (skb->len > self->max_seg_size) {
 576                IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
 577                ret = -EMSGSIZE;
 578                goto err;
 579        }
 580
 581        irlmp_udata_request(self->lsap, skb);
 582        self->stats.tx_packets++;
 583
 584        return 0;
 585
 586err:
 587        dev_kfree_skb(skb);
 588        return ret;
 589}
 590EXPORT_SYMBOL(irttp_udata_request);
 591
 592
 593/*
 594 * Function irttp_data_request (handle, skb)
 595 *
 596 *    Queue frame for transmission. If SAR is enabled, fragement the frame
 597 *    and queue the fragments for transmission
 598 */
 599int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 600{
 601        __u8 *frame;
 602        int ret;
 603
 604        IRDA_ASSERT(self != NULL, return -1;);
 605        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 606        IRDA_ASSERT(skb != NULL, return -1;);
 607
 608        IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
 609                   skb_queue_len(&self->tx_queue));
 610
 611        /* Take shortcut on zero byte packets */
 612        if (skb->len == 0) {
 613                ret = 0;
 614                goto err;
 615        }
 616
 617        /* Check that nothing bad happens */
 618        if (!self->connected) {
 619                IRDA_WARNING("%s: Not connected\n", __func__);
 620                ret = -ENOTCONN;
 621                goto err;
 622        }
 623
 624        /*
 625         *  Check if SAR is disabled, and the frame is larger than what fits
 626         *  inside an IrLAP frame
 627         */
 628        if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 629                IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
 630                           __func__);
 631                ret = -EMSGSIZE;
 632                goto err;
 633        }
 634
 635        /*
 636         *  Check if SAR is enabled, and the frame is larger than the
 637         *  TxMaxSduSize
 638         */
 639        if ((self->tx_max_sdu_size != 0) &&
 640            (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 641            (skb->len > self->tx_max_sdu_size))
 642        {
 643                IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 644                           __func__);
 645                ret = -EMSGSIZE;
 646                goto err;
 647        }
 648        /*
 649         *  Check if transmit queue is full
 650         */
 651        if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 652                /*
 653                 *  Give it a chance to empty itself
 654                 */
 655                irttp_run_tx_queue(self);
 656
 657                /* Drop packet. This error code should trigger the caller
 658                 * to resend the data in the client code - Jean II */
 659                ret = -ENOBUFS;
 660                goto err;
 661        }
 662
 663        /* Queue frame, or queue frame segments */
 664        if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 665                /* Queue frame */
 666                IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 667                frame = skb_push(skb, TTP_HEADER);
 668                frame[0] = 0x00; /* Clear more bit */
 669
 670                skb_queue_tail(&self->tx_queue, skb);
 671        } else {
 672                /*
 673                 *  Fragment the frame, this function will also queue the
 674                 *  fragments, we don't care about the fact the transmit
 675                 *  queue may be overfilled by all the segments for a little
 676                 *  while
 677                 */
 678                irttp_fragment_skb(self, skb);
 679        }
 680
 681        /* Check if we can accept more data from client */
 682        if ((!self->tx_sdu_busy) &&
 683            (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 684                /* Tx queue filling up, so stop client. */
 685                if (self->notify.flow_indication) {
 686                        self->notify.flow_indication(self->notify.instance,
 687                                                     self, FLOW_STOP);
 688                }
 689                /* self->tx_sdu_busy is the state of the client.
 690                 * Update state after notifying client to avoid
 691                 * race condition with irttp_flow_indication().
 692                 * If the queue empty itself after our test but before
 693                 * we set the flag, we will fix ourselves below in
 694                 * irttp_run_tx_queue().
 695                 * Jean II */
 696                self->tx_sdu_busy = TRUE;
 697        }
 698
 699        /* Try to make some progress */
 700        irttp_run_tx_queue(self);
 701
 702        return 0;
 703
 704err:
 705        dev_kfree_skb(skb);
 706        return ret;
 707}
 708EXPORT_SYMBOL(irttp_data_request);
 709
 710/*
 711 * Function irttp_run_tx_queue (self)
 712 *
 713 *    Transmit packets queued for transmission (if possible)
 714 *
 715 */
 716static void irttp_run_tx_queue(struct tsap_cb *self)
 717{
 718        struct sk_buff *skb;
 719        unsigned long flags;
 720        int n;
 721
 722        IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 723                   __func__,
 724                   self->send_credit, skb_queue_len(&self->tx_queue));
 725
 726        /* Get exclusive access to the tx queue, otherwise don't touch it */
 727        if (irda_lock(&self->tx_queue_lock) == FALSE)
 728                return;
 729
 730        /* Try to send out frames as long as we have credits
 731         * and as long as LAP is not full. If LAP is full, it will
 732         * poll us through irttp_flow_indication() - Jean II */
 733        while ((self->send_credit > 0) &&
 734               (!irlmp_lap_tx_queue_full(self->lsap)) &&
 735               (skb = skb_dequeue(&self->tx_queue)))
 736        {
 737                /*
 738                 *  Since we can transmit and receive frames concurrently,
 739                 *  the code below is a critical region and we must assure that
 740                 *  nobody messes with the credits while we update them.
 741                 */
 742                spin_lock_irqsave(&self->lock, flags);
 743
 744                n = self->avail_credit;
 745                self->avail_credit = 0;
 746
 747                /* Only room for 127 credits in frame */
 748                if (n > 127) {
 749                        self->avail_credit = n-127;
 750                        n = 127;
 751                }
 752                self->remote_credit += n;
 753                self->send_credit--;
 754
 755                spin_unlock_irqrestore(&self->lock, flags);
 756
 757                /*
 758                 *  More bit must be set by the data_request() or fragment()
 759                 *  functions
 760                 */
 761                skb->data[0] |= (n & 0x7f);
 762
 763                /* Detach from socket.
 764                 * The current skb has a reference to the socket that sent
 765                 * it (skb->sk). When we pass it to IrLMP, the skb will be
 766                 * stored in in IrLAP (self->wx_list). When we are within
 767                 * IrLAP, we lose the notion of socket, so we should not
 768                 * have a reference to a socket. So, we drop it here.
 769                 *
 770                 * Why does it matter ?
 771                 * When the skb is freed (kfree_skb), if it is associated
 772                 * with a socket, it release buffer space on the socket
 773                 * (through sock_wfree() and sock_def_write_space()).
 774                 * If the socket no longer exist, we may crash. Hard.
 775                 * When we close a socket, we make sure that associated packets
 776                 * in IrTTP are freed. However, we have no way to cancel
 777                 * the packet that we have passed to IrLAP. So, if a packet
 778                 * remains in IrLAP (retry on the link or else) after we
 779                 * close the socket, we are dead !
 780                 * Jean II */
 781                if (skb->sk != NULL) {
 782                        /* IrSOCK application, IrOBEX, ... */
 783                        skb_orphan(skb);
 784                }
 785                        /* IrCOMM over IrTTP, IrLAN, ... */
 786
 787                /* Pass the skb to IrLMP - done */
 788                irlmp_data_request(self->lsap, skb);
 789                self->stats.tx_packets++;
 790        }
 791
 792        /* Check if we can accept more frames from client.
 793         * We don't want to wait until the todo timer to do that, and we
 794         * can't use tasklets (grr...), so we are obliged to give control
 795         * to client. That's ok, this test will be true not too often
 796         * (max once per LAP window) and we are called from places
 797         * where we can spend a bit of time doing stuff. - Jean II */
 798        if ((self->tx_sdu_busy) &&
 799            (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 800            (!self->close_pend))
 801        {
 802                if (self->notify.flow_indication)
 803                        self->notify.flow_indication(self->notify.instance,
 804                                                     self, FLOW_START);
 805
 806                /* self->tx_sdu_busy is the state of the client.
 807                 * We don't really have a race here, but it's always safer
 808                 * to update our state after the client - Jean II */
 809                self->tx_sdu_busy = FALSE;
 810        }
 811
 812        /* Reset lock */
 813        self->tx_queue_lock = 0;
 814}
 815
 816/*
 817 * Function irttp_give_credit (self)
 818 *
 819 *    Send a dataless flowdata TTP-PDU and give available credit to peer
 820 *    TSAP
 821 */
 822static inline void irttp_give_credit(struct tsap_cb *self)
 823{
 824        struct sk_buff *tx_skb = NULL;
 825        unsigned long flags;
 826        int n;
 827
 828        IRDA_ASSERT(self != NULL, return;);
 829        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 830
 831        IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 832                   __func__,
 833                   self->send_credit, self->avail_credit, self->remote_credit);
 834
 835        /* Give credit to peer */
 836        tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
 837        if (!tx_skb)
 838                return;
 839
 840        /* Reserve space for LMP, and LAP header */
 841        skb_reserve(tx_skb, LMP_MAX_HEADER);
 842
 843        /*
 844         *  Since we can transmit and receive frames concurrently,
 845         *  the code below is a critical region and we must assure that
 846         *  nobody messes with the credits while we update them.
 847         */
 848        spin_lock_irqsave(&self->lock, flags);
 849
 850        n = self->avail_credit;
 851        self->avail_credit = 0;
 852
 853        /* Only space for 127 credits in frame */
 854        if (n > 127) {
 855                self->avail_credit = n - 127;
 856                n = 127;
 857        }
 858        self->remote_credit += n;
 859
 860        spin_unlock_irqrestore(&self->lock, flags);
 861
 862        skb_put(tx_skb, 1);
 863        tx_skb->data[0] = (__u8) (n & 0x7f);
 864
 865        irlmp_data_request(self->lsap, tx_skb);
 866        self->stats.tx_packets++;
 867}
 868
 869/*
 870 * Function irttp_udata_indication (instance, sap, skb)
 871 *
 872 *    Received some unit-data (unreliable)
 873 *
 874 */
 875static int irttp_udata_indication(void *instance, void *sap,
 876                                  struct sk_buff *skb)
 877{
 878        struct tsap_cb *self;
 879        int err;
 880
 881        IRDA_DEBUG(4, "%s()\n", __func__);
 882
 883        self = instance;
 884
 885        IRDA_ASSERT(self != NULL, return -1;);
 886        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 887        IRDA_ASSERT(skb != NULL, return -1;);
 888
 889        self->stats.rx_packets++;
 890
 891        /* Just pass data to layer above */
 892        if (self->notify.udata_indication) {
 893                err = self->notify.udata_indication(self->notify.instance,
 894                                                    self,skb);
 895                /* Same comment as in irttp_do_data_indication() */
 896                if (!err)
 897                        return 0;
 898        }
 899        /* Either no handler, or handler returns an error */
 900        dev_kfree_skb(skb);
 901
 902        return 0;
 903}
 904
 905/*
 906 * Function irttp_data_indication (instance, sap, skb)
 907 *
 908 *    Receive segment from IrLMP.
 909 *
 910 */
 911static int irttp_data_indication(void *instance, void *sap,
 912                                 struct sk_buff *skb)
 913{
 914        struct tsap_cb *self;
 915        unsigned long flags;
 916        int n;
 917
 918        self = instance;
 919
 920        n = skb->data[0] & 0x7f;     /* Extract the credits */
 921
 922        self->stats.rx_packets++;
 923
 924        /*  Deal with inbound credit
 925         *  Since we can transmit and receive frames concurrently,
 926         *  the code below is a critical region and we must assure that
 927         *  nobody messes with the credits while we update them.
 928         */
 929        spin_lock_irqsave(&self->lock, flags);
 930        self->send_credit += n;
 931        if (skb->len > 1)
 932                self->remote_credit--;
 933        spin_unlock_irqrestore(&self->lock, flags);
 934
 935        /*
 936         *  Data or dataless packet? Dataless frames contains only the
 937         *  TTP_HEADER.
 938         */
 939        if (skb->len > 1) {
 940                /*
 941                 *  We don't remove the TTP header, since we must preserve the
 942                 *  more bit, so the defragment routing knows what to do
 943                 */
 944                skb_queue_tail(&self->rx_queue, skb);
 945        } else {
 946                /* Dataless flowdata TTP-PDU */
 947                dev_kfree_skb(skb);
 948        }
 949
 950
 951        /* Push data to the higher layer.
 952         * We do it synchronously because running the todo timer for each
 953         * receive packet would be too much overhead and latency.
 954         * By passing control to the higher layer, we run the risk that
 955         * it may take time or grab a lock. Most often, the higher layer
 956         * will only put packet in a queue.
 957         * Anyway, packets are only dripping through the IrDA, so we can
 958         * have time before the next packet.
 959         * Further, we are run from NET_BH, so the worse that can happen is
 960         * us missing the optimal time to send back the PF bit in LAP.
 961         * Jean II */
 962        irttp_run_rx_queue(self);
 963
 964        /* We now give credits to peer in irttp_run_rx_queue().
 965         * We need to send credit *NOW*, otherwise we are going
 966         * to miss the next Tx window. The todo timer may take
 967         * a while before it's run... - Jean II */
 968
 969        /*
 970         * If the peer device has given us some credits and we didn't have
 971         * anyone from before, then we need to shedule the tx queue.
 972         * We need to do that because our Tx have stopped (so we may not
 973         * get any LAP flow indication) and the user may be stopped as
 974         * well. - Jean II
 975         */
 976        if (self->send_credit == n) {
 977                /* Restart pushing stuff to LAP */
 978                irttp_run_tx_queue(self);
 979                /* Note : we don't want to schedule the todo timer
 980                 * because it has horrible latency. No tasklets
 981                 * because the tasklet API is broken. - Jean II */
 982        }
 983
 984        return 0;
 985}
 986
 987/*
 988 * Function irttp_status_indication (self, reason)
 989 *
 990 *    Status_indication, just pass to the higher layer...
 991 *
 992 */
 993static void irttp_status_indication(void *instance,
 994                                    LINK_STATUS link, LOCK_STATUS lock)
 995{
 996        struct tsap_cb *self;
 997
 998        IRDA_DEBUG(4, "%s()\n", __func__);
 999
1000        self = instance;
1001
1002        IRDA_ASSERT(self != NULL, return;);
1003        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1004
1005        /* Check if client has already closed the TSAP and gone away */
1006        if (self->close_pend)
1007                return;
1008
1009        /*
1010         *  Inform service user if he has requested it
1011         */
1012        if (self->notify.status_indication != NULL)
1013                self->notify.status_indication(self->notify.instance,
1014                                               link, lock);
1015        else
1016                IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1017}
1018
1019/*
1020 * Function irttp_flow_indication (self, reason)
1021 *
1022 *    Flow_indication : IrLAP tells us to send more data.
1023 *
1024 */
1025static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1026{
1027        struct tsap_cb *self;
1028
1029        self = instance;
1030
1031        IRDA_ASSERT(self != NULL, return;);
1032        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1033
1034        IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1035
1036        /* We are "polled" directly from LAP, and the LAP want to fill
1037         * its Tx window. We want to do our best to send it data, so that
1038         * we maximise the window. On the other hand, we want to limit the
1039         * amount of work here so that LAP doesn't hang forever waiting
1040         * for packets. - Jean II */
1041
1042        /* Try to send some packets. Currently, LAP calls us every time
1043         * there is one free slot, so we will send only one packet.
1044         * This allow the scheduler to do its round robin - Jean II */
1045        irttp_run_tx_queue(self);
1046
1047        /* Note regarding the interraction with higher layer.
1048         * irttp_run_tx_queue() may call the client when its queue
1049         * start to empty, via notify.flow_indication(). Initially.
1050         * I wanted this to happen in a tasklet, to avoid client
1051         * grabbing the CPU, but we can't use tasklets safely. And timer
1052         * is definitely too slow.
1053         * This will happen only once per LAP window, and usually at
1054         * the third packet (unless window is smaller). LAP is still
1055         * doing mtt and sending first packet so it's sort of OK
1056         * to do that. Jean II */
1057
1058        /* If we need to send disconnect. try to do it now */
1059        if(self->disconnect_pend)
1060                irttp_start_todo_timer(self, 0);
1061}
1062
1063/*
1064 * Function irttp_flow_request (self, command)
1065 *
1066 *    This function could be used by the upper layers to tell IrTTP to stop
1067 *    delivering frames if the receive queues are starting to get full, or
1068 *    to tell IrTTP to start delivering frames again.
1069 */
1070void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1071{
1072        IRDA_DEBUG(1, "%s()\n", __func__);
1073
1074        IRDA_ASSERT(self != NULL, return;);
1075        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1076
1077        switch (flow) {
1078        case FLOW_STOP:
1079                IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1080                self->rx_sdu_busy = TRUE;
1081                break;
1082        case FLOW_START:
1083                IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1084                self->rx_sdu_busy = FALSE;
1085
1086                /* Client say he can accept more data, try to free our
1087                 * queues ASAP - Jean II */
1088                irttp_run_rx_queue(self);
1089
1090                break;
1091        default:
1092                IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1093        }
1094}
1095EXPORT_SYMBOL(irttp_flow_request);
1096
1097/*
1098 * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1099 *
1100 *    Try to connect to remote destination TSAP selector
1101 *
1102 */
1103int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1104                          __u32 saddr, __u32 daddr,
1105                          struct qos_info *qos, __u32 max_sdu_size,
1106                          struct sk_buff *userdata)
1107{
1108        struct sk_buff *tx_skb;
1109        __u8 *frame;
1110        __u8 n;
1111
1112        IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1113
1114        IRDA_ASSERT(self != NULL, return -EBADR;);
1115        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1116
1117        if (self->connected) {
1118                if(userdata)
1119                        dev_kfree_skb(userdata);
1120                return -EISCONN;
1121        }
1122
1123        /* Any userdata supplied? */
1124        if (userdata == NULL) {
1125                tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1126                                   GFP_ATOMIC);
1127                if (!tx_skb)
1128                        return -ENOMEM;
1129
1130                /* Reserve space for MUX_CONTROL and LAP header */
1131                skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1132        } else {
1133                tx_skb = userdata;
1134                /*
1135                 *  Check that the client has reserved enough space for
1136                 *  headers
1137                 */
1138                IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1139                        { dev_kfree_skb(userdata); return -1; } );
1140        }
1141
1142        /* Initialize connection parameters */
1143        self->connected = FALSE;
1144        self->avail_credit = 0;
1145        self->rx_max_sdu_size = max_sdu_size;
1146        self->rx_sdu_size = 0;
1147        self->rx_sdu_busy = FALSE;
1148        self->dtsap_sel = dtsap_sel;
1149
1150        n = self->initial_credit;
1151
1152        self->remote_credit = 0;
1153        self->send_credit = 0;
1154
1155        /*
1156         *  Give away max 127 credits for now
1157         */
1158        if (n > 127) {
1159                self->avail_credit=n-127;
1160                n = 127;
1161        }
1162
1163        self->remote_credit = n;
1164
1165        /* SAR enabled? */
1166        if (max_sdu_size > 0) {
1167                IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1168                        { dev_kfree_skb(tx_skb); return -1; } );
1169
1170                /* Insert SAR parameters */
1171                frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1172
1173                frame[0] = TTP_PARAMETERS | n;
1174                frame[1] = 0x04; /* Length */
1175                frame[2] = 0x01; /* MaxSduSize */
1176                frame[3] = 0x02; /* Value length */
1177
1178                put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1179                              (__be16 *)(frame+4));
1180        } else {
1181                /* Insert plain TTP header */
1182                frame = skb_push(tx_skb, TTP_HEADER);
1183
1184                /* Insert initial credit in frame */
1185                frame[0] = n & 0x7f;
1186        }
1187
1188        /* Connect with IrLMP. No QoS parameters for now */
1189        return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1190                                     tx_skb);
1191}
1192EXPORT_SYMBOL(irttp_connect_request);
1193
1194/*
1195 * Function irttp_connect_confirm (handle, qos, skb)
1196 *
1197 *    Service user confirms TSAP connection with peer.
1198 *
1199 */
1200static void irttp_connect_confirm(void *instance, void *sap,
1201                                  struct qos_info *qos, __u32 max_seg_size,
1202                                  __u8 max_header_size, struct sk_buff *skb)
1203{
1204        struct tsap_cb *self;
1205        int parameters;
1206        int ret;
1207        __u8 plen;
1208        __u8 n;
1209
1210        IRDA_DEBUG(4, "%s()\n", __func__);
1211
1212        self = instance;
1213
1214        IRDA_ASSERT(self != NULL, return;);
1215        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1216        IRDA_ASSERT(skb != NULL, return;);
1217
1218        self->max_seg_size = max_seg_size - TTP_HEADER;
1219        self->max_header_size = max_header_size + TTP_HEADER;
1220
1221        /*
1222         *  Check if we have got some QoS parameters back! This should be the
1223         *  negotiated QoS for the link.
1224         */
1225        if (qos) {
1226                IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1227                       qos->baud_rate.bits);
1228                IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1229                       qos->baud_rate.value);
1230        }
1231
1232        n = skb->data[0] & 0x7f;
1233
1234        IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1235
1236        self->send_credit = n;
1237        self->tx_max_sdu_size = 0;
1238        self->connected = TRUE;
1239
1240        parameters = skb->data[0] & 0x80;
1241
1242        IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1243        skb_pull(skb, TTP_HEADER);
1244
1245        if (parameters) {
1246                plen = skb->data[0];
1247
1248                ret = irda_param_extract_all(self, skb->data+1,
1249                                             IRDA_MIN(skb->len-1, plen),
1250                                             &param_info);
1251
1252                /* Any errors in the parameter list? */
1253                if (ret < 0) {
1254                        IRDA_WARNING("%s: error extracting parameters\n",
1255                                     __func__);
1256                        dev_kfree_skb(skb);
1257
1258                        /* Do not accept this connection attempt */
1259                        return;
1260                }
1261                /* Remove parameters */
1262                skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1263        }
1264
1265        IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1266              self->send_credit, self->avail_credit, self->remote_credit);
1267
1268        IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1269                   self->tx_max_sdu_size);
1270
1271        if (self->notify.connect_confirm) {
1272                self->notify.connect_confirm(self->notify.instance, self, qos,
1273                                             self->tx_max_sdu_size,
1274                                             self->max_header_size, skb);
1275        } else
1276                dev_kfree_skb(skb);
1277}
1278
1279/*
1280 * Function irttp_connect_indication (handle, skb)
1281 *
1282 *    Some other device is connecting to this TSAP
1283 *
1284 */
1285static void irttp_connect_indication(void *instance, void *sap,
1286                struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1287                struct sk_buff *skb)
1288{
1289        struct tsap_cb *self;
1290        struct lsap_cb *lsap;
1291        int parameters;
1292        int ret;
1293        __u8 plen;
1294        __u8 n;
1295
1296        self = instance;
1297
1298        IRDA_ASSERT(self != NULL, return;);
1299        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1300        IRDA_ASSERT(skb != NULL, return;);
1301
1302        lsap = sap;
1303
1304        self->max_seg_size = max_seg_size - TTP_HEADER;
1305        self->max_header_size = max_header_size+TTP_HEADER;
1306
1307        IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1308
1309        /* Need to update dtsap_sel if its equal to LSAP_ANY */
1310        self->dtsap_sel = lsap->dlsap_sel;
1311
1312        n = skb->data[0] & 0x7f;
1313
1314        self->send_credit = n;
1315        self->tx_max_sdu_size = 0;
1316
1317        parameters = skb->data[0] & 0x80;
1318
1319        IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1320        skb_pull(skb, TTP_HEADER);
1321
1322        if (parameters) {
1323                plen = skb->data[0];
1324
1325                ret = irda_param_extract_all(self, skb->data+1,
1326                                             IRDA_MIN(skb->len-1, plen),
1327                                             &param_info);
1328
1329                /* Any errors in the parameter list? */
1330                if (ret < 0) {
1331                        IRDA_WARNING("%s: error extracting parameters\n",
1332                                     __func__);
1333                        dev_kfree_skb(skb);
1334
1335                        /* Do not accept this connection attempt */
1336                        return;
1337                }
1338
1339                /* Remove parameters */
1340                skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1341        }
1342
1343        if (self->notify.connect_indication) {
1344                self->notify.connect_indication(self->notify.instance, self,
1345                                                qos, self->tx_max_sdu_size,
1346                                                self->max_header_size, skb);
1347        } else
1348                dev_kfree_skb(skb);
1349}
1350
1351/*
1352 * Function irttp_connect_response (handle, userdata)
1353 *
1354 *    Service user is accepting the connection, just pass it down to
1355 *    IrLMP!
1356 *
1357 */
1358int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1359                           struct sk_buff *userdata)
1360{
1361        struct sk_buff *tx_skb;
1362        __u8 *frame;
1363        int ret;
1364        __u8 n;
1365
1366        IRDA_ASSERT(self != NULL, return -1;);
1367        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1368
1369        IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1370                   self->stsap_sel);
1371
1372        /* Any userdata supplied? */
1373        if (userdata == NULL) {
1374                tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1375                                   GFP_ATOMIC);
1376                if (!tx_skb)
1377                        return -ENOMEM;
1378
1379                /* Reserve space for MUX_CONTROL and LAP header */
1380                skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1381        } else {
1382                tx_skb = userdata;
1383                /*
1384                 *  Check that the client has reserved enough space for
1385                 *  headers
1386                 */
1387                IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1388                        { dev_kfree_skb(userdata); return -1; } );
1389        }
1390
1391        self->avail_credit = 0;
1392        self->remote_credit = 0;
1393        self->rx_max_sdu_size = max_sdu_size;
1394        self->rx_sdu_size = 0;
1395        self->rx_sdu_busy = FALSE;
1396
1397        n = self->initial_credit;
1398
1399        /* Frame has only space for max 127 credits (7 bits) */
1400        if (n > 127) {
1401                self->avail_credit = n - 127;
1402                n = 127;
1403        }
1404
1405        self->remote_credit = n;
1406        self->connected = TRUE;
1407
1408        /* SAR enabled? */
1409        if (max_sdu_size > 0) {
1410                IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1411                        { dev_kfree_skb(tx_skb); return -1; } );
1412
1413                /* Insert TTP header with SAR parameters */
1414                frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1415
1416                frame[0] = TTP_PARAMETERS | n;
1417                frame[1] = 0x04; /* Length */
1418
1419                /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1420/*                                TTP_SAR_HEADER, &param_info) */
1421
1422                frame[2] = 0x01; /* MaxSduSize */
1423                frame[3] = 0x02; /* Value length */
1424
1425                put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1426                              (__be16 *)(frame+4));
1427        } else {
1428                /* Insert TTP header */
1429                frame = skb_push(tx_skb, TTP_HEADER);
1430
1431                frame[0] = n & 0x7f;
1432        }
1433
1434        ret = irlmp_connect_response(self->lsap, tx_skb);
1435
1436        return ret;
1437}
1438EXPORT_SYMBOL(irttp_connect_response);
1439
1440/*
1441 * Function irttp_dup (self, instance)
1442 *
1443 *    Duplicate TSAP, can be used by servers to confirm a connection on a
1444 *    new TSAP so it can keep listening on the old one.
1445 */
1446struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1447{
1448        struct tsap_cb *new;
1449        unsigned long flags;
1450
1451        IRDA_DEBUG(1, "%s()\n", __func__);
1452
1453        /* Protect our access to the old tsap instance */
1454        spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1455
1456        /* Find the old instance */
1457        if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1458                IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1459                spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1460                return NULL;
1461        }
1462
1463        /* Allocate a new instance */
1464        new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
1465        if (!new) {
1466                IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1467                spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1468                return NULL;
1469        }
1470        spin_lock_init(&new->lock);
1471
1472        /* We don't need the old instance any more */
1473        spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1474
1475        /* Try to dup the LSAP (may fail if we were too slow) */
1476        new->lsap = irlmp_dup(orig->lsap, new);
1477        if (!new->lsap) {
1478                IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1479                kfree(new);
1480                return NULL;
1481        }
1482
1483        /* Not everything should be copied */
1484        new->notify.instance = instance;
1485
1486        /* Initialize internal objects */
1487        irttp_init_tsap(new);
1488
1489        /* This is locked */
1490        hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1491
1492        return new;
1493}
1494EXPORT_SYMBOL(irttp_dup);
1495
1496/*
1497 * Function irttp_disconnect_request (self)
1498 *
1499 *    Close this connection please! If priority is high, the queued data
1500 *    segments, if any, will be deallocated first
1501 *
1502 */
1503int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1504                             int priority)
1505{
1506        int ret;
1507
1508        IRDA_ASSERT(self != NULL, return -1;);
1509        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1510
1511        /* Already disconnected? */
1512        if (!self->connected) {
1513                IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1514                if (userdata)
1515                        dev_kfree_skb(userdata);
1516                return -1;
1517        }
1518
1519        /* Disconnect already pending ?
1520         * We need to use an atomic operation to prevent reentry. This
1521         * function may be called from various context, like user, timer
1522         * for following a disconnect_indication() (i.e. net_bh).
1523         * Jean II */
1524        if(test_and_set_bit(0, &self->disconnect_pend)) {
1525                IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1526                           __func__);
1527                if (userdata)
1528                        dev_kfree_skb(userdata);
1529
1530                /* Try to make some progress */
1531                irttp_run_tx_queue(self);
1532                return -1;
1533        }
1534
1535        /*
1536         *  Check if there is still data segments in the transmit queue
1537         */
1538        if (!skb_queue_empty(&self->tx_queue)) {
1539                if (priority == P_HIGH) {
1540                        /*
1541                         *  No need to send the queued data, if we are
1542                         *  disconnecting right now since the data will
1543                         *  not have any usable connection to be sent on
1544                         */
1545                        IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1546                        irttp_flush_queues(self);
1547                } else if (priority == P_NORMAL) {
1548                        /*
1549                         *  Must delay disconnect until after all data segments
1550                         *  have been sent and the tx_queue is empty
1551                         */
1552                        /* We'll reuse this one later for the disconnect */
1553                        self->disconnect_skb = userdata;  /* May be NULL */
1554
1555                        irttp_run_tx_queue(self);
1556
1557                        irttp_start_todo_timer(self, HZ/10);
1558                        return -1;
1559                }
1560        }
1561        /* Note : we don't need to check if self->rx_queue is full and the
1562         * state of self->rx_sdu_busy because the disconnect response will
1563         * be sent at the LMP level (so even if the peer has its Tx queue
1564         * full of data). - Jean II */
1565
1566        IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1567        self->connected = FALSE;
1568
1569        if (!userdata) {
1570                struct sk_buff *tx_skb;
1571                tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1572                if (!tx_skb)
1573                        return -ENOMEM;
1574
1575                /*
1576                 *  Reserve space for MUX and LAP header
1577                 */
1578                skb_reserve(tx_skb, LMP_MAX_HEADER);
1579
1580                userdata = tx_skb;
1581        }
1582        ret = irlmp_disconnect_request(self->lsap, userdata);
1583
1584        /* The disconnect is no longer pending */
1585        clear_bit(0, &self->disconnect_pend);   /* FALSE */
1586
1587        return ret;
1588}
1589EXPORT_SYMBOL(irttp_disconnect_request);
1590
1591/*
1592 * Function irttp_disconnect_indication (self, reason)
1593 *
1594 *    Disconnect indication, TSAP disconnected by peer?
1595 *
1596 */
1597static void irttp_disconnect_indication(void *instance, void *sap,
1598                LM_REASON reason, struct sk_buff *skb)
1599{
1600        struct tsap_cb *self;
1601
1602        IRDA_DEBUG(4, "%s()\n", __func__);
1603
1604        self = instance;
1605
1606        IRDA_ASSERT(self != NULL, return;);
1607        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1608
1609        /* Prevent higher layer to send more data */
1610        self->connected = FALSE;
1611
1612        /* Check if client has already tried to close the TSAP */
1613        if (self->close_pend) {
1614                /* In this case, the higher layer is probably gone. Don't
1615                 * bother it and clean up the remains - Jean II */
1616                if (skb)
1617                        dev_kfree_skb(skb);
1618                irttp_close_tsap(self);
1619                return;
1620        }
1621
1622        /* If we are here, we assume that is the higher layer is still
1623         * waiting for the disconnect notification and able to process it,
1624         * even if he tried to disconnect. Otherwise, it would have already
1625         * attempted to close the tsap and self->close_pend would be TRUE.
1626         * Jean II */
1627
1628        /* No need to notify the client if has already tried to disconnect */
1629        if(self->notify.disconnect_indication)
1630                self->notify.disconnect_indication(self->notify.instance, self,
1631                                                   reason, skb);
1632        else
1633                if (skb)
1634                        dev_kfree_skb(skb);
1635}
1636
1637/*
1638 * Function irttp_do_data_indication (self, skb)
1639 *
1640 *    Try to deliver reassembled skb to layer above, and requeue it if that
1641 *    for some reason should fail. We mark rx sdu as busy to apply back
1642 *    pressure is necessary.
1643 */
1644static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1645{
1646        int err;
1647
1648        /* Check if client has already closed the TSAP and gone away */
1649        if (self->close_pend) {
1650                dev_kfree_skb(skb);
1651                return;
1652        }
1653
1654        err = self->notify.data_indication(self->notify.instance, self, skb);
1655
1656        /* Usually the layer above will notify that it's input queue is
1657         * starting to get filled by using the flow request, but this may
1658         * be difficult, so it can instead just refuse to eat it and just
1659         * give an error back
1660         */
1661        if (err) {
1662                IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1663
1664                /* Make sure we take a break */
1665                self->rx_sdu_busy = TRUE;
1666
1667                /* Need to push the header in again */
1668                skb_push(skb, TTP_HEADER);
1669                skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1670
1671                /* Put skb back on queue */
1672                skb_queue_head(&self->rx_queue, skb);
1673        }
1674}
1675
1676/*
1677 * Function irttp_run_rx_queue (self)
1678 *
1679 *     Check if we have any frames to be transmitted, or if we have any
1680 *     available credit to give away.
1681 */
1682static void irttp_run_rx_queue(struct tsap_cb *self)
1683{
1684        struct sk_buff *skb;
1685        int more = 0;
1686
1687        IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1688                   self->send_credit, self->avail_credit, self->remote_credit);
1689
1690        /* Get exclusive access to the rx queue, otherwise don't touch it */
1691        if (irda_lock(&self->rx_queue_lock) == FALSE)
1692                return;
1693
1694        /*
1695         *  Reassemble all frames in receive queue and deliver them
1696         */
1697        while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1698                /* This bit will tell us if it's the last fragment or not */
1699                more = skb->data[0] & 0x80;
1700
1701                /* Remove TTP header */
1702                skb_pull(skb, TTP_HEADER);
1703
1704                /* Add the length of the remaining data */
1705                self->rx_sdu_size += skb->len;
1706
1707                /*
1708                 * If SAR is disabled, or user has requested no reassembly
1709                 * of received fragments then we just deliver them
1710                 * immediately. This can be requested by clients that
1711                 * implements byte streams without any message boundaries
1712                 */
1713                if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1714                        irttp_do_data_indication(self, skb);
1715                        self->rx_sdu_size = 0;
1716
1717                        continue;
1718                }
1719
1720                /* Check if this is a fragment, and not the last fragment */
1721                if (more) {
1722                        /*
1723                         *  Queue the fragment if we still are within the
1724                         *  limits of the maximum size of the rx_sdu
1725                         */
1726                        if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1727                                IRDA_DEBUG(4, "%s(), queueing frag\n",
1728                                           __func__);
1729                                skb_queue_tail(&self->rx_fragments, skb);
1730                        } else {
1731                                /* Free the part of the SDU that is too big */
1732                                dev_kfree_skb(skb);
1733                        }
1734                        continue;
1735                }
1736                /*
1737                 *  This is the last fragment, so time to reassemble!
1738                 */
1739                if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1740                    (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1741                {
1742                        /*
1743                         * A little optimizing. Only queue the fragment if
1744                         * there are other fragments. Since if this is the
1745                         * last and only fragment, there is no need to
1746                         * reassemble :-)
1747                         */
1748                        if (!skb_queue_empty(&self->rx_fragments)) {
1749                                skb_queue_tail(&self->rx_fragments,
1750                                               skb);
1751
1752                                skb = irttp_reassemble_skb(self);
1753                        }
1754
1755                        /* Now we can deliver the reassembled skb */
1756                        irttp_do_data_indication(self, skb);
1757                } else {
1758                        IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1759
1760                        /* Free the part of the SDU that is too big */
1761                        dev_kfree_skb(skb);
1762
1763                        /* Deliver only the valid but truncated part of SDU */
1764                        skb = irttp_reassemble_skb(self);
1765
1766                        irttp_do_data_indication(self, skb);
1767                }
1768                self->rx_sdu_size = 0;
1769        }
1770
1771        /*
1772         * It's not trivial to keep track of how many credits are available
1773         * by incrementing at each packet, because delivery may fail
1774         * (irttp_do_data_indication() may requeue the frame) and because
1775         * we need to take care of fragmentation.
1776         * We want the other side to send up to initial_credit packets.
1777         * We have some frames in our queues, and we have already allowed it
1778         * to send remote_credit.
1779         * No need to spinlock, write is atomic and self correcting...
1780         * Jean II
1781         */
1782        self->avail_credit = (self->initial_credit -
1783                              (self->remote_credit +
1784                               skb_queue_len(&self->rx_queue) +
1785                               skb_queue_len(&self->rx_fragments)));
1786
1787        /* Do we have too much credits to send to peer ? */
1788        if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1789            (self->avail_credit > 0)) {
1790                /* Send explicit credit frame */
1791                irttp_give_credit(self);
1792                /* Note : do *NOT* check if tx_queue is non-empty, that
1793                 * will produce deadlocks. I repeat : send a credit frame
1794                 * even if we have something to send in our Tx queue.
1795                 * If we have credits, it means that our Tx queue is blocked.
1796                 *
1797                 * Let's suppose the peer can't keep up with our Tx. He will
1798                 * flow control us by not sending us any credits, and we
1799                 * will stop Tx and start accumulating credits here.
1800                 * Up to the point where the peer will stop its Tx queue,
1801                 * for lack of credits.
1802                 * Let's assume the peer application is single threaded.
1803                 * It will block on Tx and never consume any Rx buffer.
1804                 * Deadlock. Guaranteed. - Jean II
1805                 */
1806        }
1807
1808        /* Reset lock */
1809        self->rx_queue_lock = 0;
1810}
1811
1812#ifdef CONFIG_PROC_FS
1813struct irttp_iter_state {
1814        int id;
1815};
1816
1817static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1818{
1819        struct irttp_iter_state *iter = seq->private;
1820        struct tsap_cb *self;
1821
1822        /* Protect our access to the tsap list */
1823        spin_lock_irq(&irttp->tsaps->hb_spinlock);
1824        iter->id = 0;
1825
1826        for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1827             self != NULL;
1828             self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1829                if (iter->id == *pos)
1830                        break;
1831                ++iter->id;
1832        }
1833
1834        return self;
1835}
1836
1837static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1838{
1839        struct irttp_iter_state *iter = seq->private;
1840
1841        ++*pos;
1842        ++iter->id;
1843        return (void *) hashbin_get_next(irttp->tsaps);
1844}
1845
1846static void irttp_seq_stop(struct seq_file *seq, void *v)
1847{
1848        spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1849}
1850
1851static int irttp_seq_show(struct seq_file *seq, void *v)
1852{
1853        const struct irttp_iter_state *iter = seq->private;
1854        const struct tsap_cb *self = v;
1855
1856        seq_printf(seq, "TSAP %d, ", iter->id);
1857        seq_printf(seq, "stsap_sel: %02x, ",
1858                   self->stsap_sel);
1859        seq_printf(seq, "dtsap_sel: %02x\n",
1860                   self->dtsap_sel);
1861        seq_printf(seq, "  connected: %s, ",
1862                   self->connected? "TRUE":"FALSE");
1863        seq_printf(seq, "avail credit: %d, ",
1864                   self->avail_credit);
1865        seq_printf(seq, "remote credit: %d, ",
1866                   self->remote_credit);
1867        seq_printf(seq, "send credit: %d\n",
1868                   self->send_credit);
1869        seq_printf(seq, "  tx packets: %lu, ",
1870                   self->stats.tx_packets);
1871        seq_printf(seq, "rx packets: %lu, ",
1872                   self->stats.rx_packets);
1873        seq_printf(seq, "tx_queue len: %u ",
1874                   skb_queue_len(&self->tx_queue));
1875        seq_printf(seq, "rx_queue len: %u\n",
1876                   skb_queue_len(&self->rx_queue));
1877        seq_printf(seq, "  tx_sdu_busy: %s, ",
1878                   self->tx_sdu_busy? "TRUE":"FALSE");
1879        seq_printf(seq, "rx_sdu_busy: %s\n",
1880                   self->rx_sdu_busy? "TRUE":"FALSE");
1881        seq_printf(seq, "  max_seg_size: %u, ",
1882                   self->max_seg_size);
1883        seq_printf(seq, "tx_max_sdu_size: %u, ",
1884                   self->tx_max_sdu_size);
1885        seq_printf(seq, "rx_max_sdu_size: %u\n",
1886                   self->rx_max_sdu_size);
1887
1888        seq_printf(seq, "  Used by (%s)\n\n",
1889                   self->notify.name);
1890        return 0;
1891}
1892
1893static const struct seq_operations irttp_seq_ops = {
1894        .start  = irttp_seq_start,
1895        .next   = irttp_seq_next,
1896        .stop   = irttp_seq_stop,
1897        .show   = irttp_seq_show,
1898};
1899
1900static int irttp_seq_open(struct inode *inode, struct file *file)
1901{
1902        return seq_open_private(file, &irttp_seq_ops,
1903                        sizeof(struct irttp_iter_state));
1904}
1905
1906const struct file_operations irttp_seq_fops = {
1907        .owner          = THIS_MODULE,
1908        .open           = irttp_seq_open,
1909        .read           = seq_read,
1910        .llseek         = seq_lseek,
1911        .release        = seq_release_private,
1912};
1913
1914#endif /* PROC_FS */
1915
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