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_DEBUG(0, "%s: unable to allocate LSAP!!\n", __func__);
 444                __irttp_close_tsap(self);
 445                return NULL;
 446        }
 447
 448        /*
 449         *  If user specified LSAP_ANY as source TSAP selector, then IrLMP
 450         *  will replace it with whatever source selector which is free, so
 451         *  the stsap_sel we have might not be valid anymore
 452         */
 453        self->stsap_sel = lsap->slsap_sel;
 454        IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
 455
 456        self->notify = *notify;
 457        self->lsap = lsap;
 458
 459        hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
 460
 461        if (credit > TTP_RX_MAX_CREDIT)
 462                self->initial_credit = TTP_RX_MAX_CREDIT;
 463        else
 464                self->initial_credit = credit;
 465
 466        return self;
 467}
 468EXPORT_SYMBOL(irttp_open_tsap);
 469
 470/*
 471 * Function irttp_close (handle)
 472 *
 473 *    Remove an instance of a TSAP. This function should only deal with the
 474 *    deallocation of the TSAP, and resetting of the TSAPs values;
 475 *
 476 */
 477static void __irttp_close_tsap(struct tsap_cb *self)
 478{
 479        /* First make sure we're connected. */
 480        IRDA_ASSERT(self != NULL, return;);
 481        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 482
 483        irttp_flush_queues(self);
 484
 485        del_timer(&self->todo_timer);
 486
 487        /* This one won't be cleaned up if we are disconnect_pend + close_pend
 488         * and we receive a disconnect_indication */
 489        if (self->disconnect_skb)
 490                dev_kfree_skb(self->disconnect_skb);
 491
 492        self->connected = FALSE;
 493        self->magic = ~TTP_TSAP_MAGIC;
 494
 495        kfree(self);
 496}
 497
 498/*
 499 * Function irttp_close (self)
 500 *
 501 *    Remove TSAP from list of all TSAPs and then deallocate all resources
 502 *    associated with this TSAP
 503 *
 504 * Note : because we *free* the tsap structure, it is the responsibility
 505 * of the caller to make sure we are called only once and to deal with
 506 * possible race conditions. - Jean II
 507 */
 508int irttp_close_tsap(struct tsap_cb *self)
 509{
 510        struct tsap_cb *tsap;
 511
 512        IRDA_DEBUG(4, "%s()\n", __func__);
 513
 514        IRDA_ASSERT(self != NULL, return -1;);
 515        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 516
 517        /* Make sure tsap has been disconnected */
 518        if (self->connected) {
 519                /* Check if disconnect is not pending */
 520                if (!test_bit(0, &self->disconnect_pend)) {
 521                        IRDA_WARNING("%s: TSAP still connected!\n",
 522                                     __func__);
 523                        irttp_disconnect_request(self, NULL, P_NORMAL);
 524                }
 525                self->close_pend = TRUE;
 526                irttp_start_todo_timer(self, HZ/10);
 527
 528                return 0; /* Will be back! */
 529        }
 530
 531        tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
 532
 533        IRDA_ASSERT(tsap == self, return -1;);
 534
 535        /* Close corresponding LSAP */
 536        if (self->lsap) {
 537                irlmp_close_lsap(self->lsap);
 538                self->lsap = NULL;
 539        }
 540
 541        __irttp_close_tsap(self);
 542
 543        return 0;
 544}
 545EXPORT_SYMBOL(irttp_close_tsap);
 546
 547/*
 548 * Function irttp_udata_request (self, skb)
 549 *
 550 *    Send unreliable data on this TSAP
 551 *
 552 */
 553int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
 554{
 555        int ret;
 556
 557        IRDA_ASSERT(self != NULL, return -1;);
 558        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 559        IRDA_ASSERT(skb != NULL, return -1;);
 560
 561        IRDA_DEBUG(4, "%s()\n", __func__);
 562
 563        /* Take shortcut on zero byte packets */
 564        if (skb->len == 0) {
 565                ret = 0;
 566                goto err;
 567        }
 568
 569        /* Check that nothing bad happens */
 570        if (!self->connected) {
 571                IRDA_WARNING("%s(), Not connected\n", __func__);
 572                ret = -ENOTCONN;
 573                goto err;
 574        }
 575
 576        if (skb->len > self->max_seg_size) {
 577                IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
 578                ret = -EMSGSIZE;
 579                goto err;
 580        }
 581
 582        irlmp_udata_request(self->lsap, skb);
 583        self->stats.tx_packets++;
 584
 585        return 0;
 586
 587err:
 588        dev_kfree_skb(skb);
 589        return ret;
 590}
 591EXPORT_SYMBOL(irttp_udata_request);
 592
 593
 594/*
 595 * Function irttp_data_request (handle, skb)
 596 *
 597 *    Queue frame for transmission. If SAR is enabled, fragement the frame
 598 *    and queue the fragments for transmission
 599 */
 600int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
 601{
 602        __u8 *frame;
 603        int ret;
 604
 605        IRDA_ASSERT(self != NULL, return -1;);
 606        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 607        IRDA_ASSERT(skb != NULL, return -1;);
 608
 609        IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
 610                   skb_queue_len(&self->tx_queue));
 611
 612        /* Take shortcut on zero byte packets */
 613        if (skb->len == 0) {
 614                ret = 0;
 615                goto err;
 616        }
 617
 618        /* Check that nothing bad happens */
 619        if (!self->connected) {
 620                IRDA_WARNING("%s: Not connected\n", __func__);
 621                ret = -ENOTCONN;
 622                goto err;
 623        }
 624
 625        /*
 626         *  Check if SAR is disabled, and the frame is larger than what fits
 627         *  inside an IrLAP frame
 628         */
 629        if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
 630                IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
 631                           __func__);
 632                ret = -EMSGSIZE;
 633                goto err;
 634        }
 635
 636        /*
 637         *  Check if SAR is enabled, and the frame is larger than the
 638         *  TxMaxSduSize
 639         */
 640        if ((self->tx_max_sdu_size != 0) &&
 641            (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
 642            (skb->len > self->tx_max_sdu_size))
 643        {
 644                IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
 645                           __func__);
 646                ret = -EMSGSIZE;
 647                goto err;
 648        }
 649        /*
 650         *  Check if transmit queue is full
 651         */
 652        if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
 653                /*
 654                 *  Give it a chance to empty itself
 655                 */
 656                irttp_run_tx_queue(self);
 657
 658                /* Drop packet. This error code should trigger the caller
 659                 * to resend the data in the client code - Jean II */
 660                ret = -ENOBUFS;
 661                goto err;
 662        }
 663
 664        /* Queue frame, or queue frame segments */
 665        if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
 666                /* Queue frame */
 667                IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
 668                frame = skb_push(skb, TTP_HEADER);
 669                frame[0] = 0x00; /* Clear more bit */
 670
 671                skb_queue_tail(&self->tx_queue, skb);
 672        } else {
 673                /*
 674                 *  Fragment the frame, this function will also queue the
 675                 *  fragments, we don't care about the fact the transmit
 676                 *  queue may be overfilled by all the segments for a little
 677                 *  while
 678                 */
 679                irttp_fragment_skb(self, skb);
 680        }
 681
 682        /* Check if we can accept more data from client */
 683        if ((!self->tx_sdu_busy) &&
 684            (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
 685                /* Tx queue filling up, so stop client. */
 686                if (self->notify.flow_indication) {
 687                        self->notify.flow_indication(self->notify.instance,
 688                                                     self, FLOW_STOP);
 689                }
 690                /* self->tx_sdu_busy is the state of the client.
 691                 * Update state after notifying client to avoid
 692                 * race condition with irttp_flow_indication().
 693                 * If the queue empty itself after our test but before
 694                 * we set the flag, we will fix ourselves below in
 695                 * irttp_run_tx_queue().
 696                 * Jean II */
 697                self->tx_sdu_busy = TRUE;
 698        }
 699
 700        /* Try to make some progress */
 701        irttp_run_tx_queue(self);
 702
 703        return 0;
 704
 705err:
 706        dev_kfree_skb(skb);
 707        return ret;
 708}
 709EXPORT_SYMBOL(irttp_data_request);
 710
 711/*
 712 * Function irttp_run_tx_queue (self)
 713 *
 714 *    Transmit packets queued for transmission (if possible)
 715 *
 716 */
 717static void irttp_run_tx_queue(struct tsap_cb *self)
 718{
 719        struct sk_buff *skb;
 720        unsigned long flags;
 721        int n;
 722
 723        IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
 724                   __func__,
 725                   self->send_credit, skb_queue_len(&self->tx_queue));
 726
 727        /* Get exclusive access to the tx queue, otherwise don't touch it */
 728        if (irda_lock(&self->tx_queue_lock) == FALSE)
 729                return;
 730
 731        /* Try to send out frames as long as we have credits
 732         * and as long as LAP is not full. If LAP is full, it will
 733         * poll us through irttp_flow_indication() - Jean II */
 734        while ((self->send_credit > 0) &&
 735               (!irlmp_lap_tx_queue_full(self->lsap)) &&
 736               (skb = skb_dequeue(&self->tx_queue)))
 737        {
 738                /*
 739                 *  Since we can transmit and receive frames concurrently,
 740                 *  the code below is a critical region and we must assure that
 741                 *  nobody messes with the credits while we update them.
 742                 */
 743                spin_lock_irqsave(&self->lock, flags);
 744
 745                n = self->avail_credit;
 746                self->avail_credit = 0;
 747
 748                /* Only room for 127 credits in frame */
 749                if (n > 127) {
 750                        self->avail_credit = n-127;
 751                        n = 127;
 752                }
 753                self->remote_credit += n;
 754                self->send_credit--;
 755
 756                spin_unlock_irqrestore(&self->lock, flags);
 757
 758                /*
 759                 *  More bit must be set by the data_request() or fragment()
 760                 *  functions
 761                 */
 762                skb->data[0] |= (n & 0x7f);
 763
 764                /* Detach from socket.
 765                 * The current skb has a reference to the socket that sent
 766                 * it (skb->sk). When we pass it to IrLMP, the skb will be
 767                 * stored in in IrLAP (self->wx_list). When we are within
 768                 * IrLAP, we lose the notion of socket, so we should not
 769                 * have a reference to a socket. So, we drop it here.
 770                 *
 771                 * Why does it matter ?
 772                 * When the skb is freed (kfree_skb), if it is associated
 773                 * with a socket, it release buffer space on the socket
 774                 * (through sock_wfree() and sock_def_write_space()).
 775                 * If the socket no longer exist, we may crash. Hard.
 776                 * When we close a socket, we make sure that associated packets
 777                 * in IrTTP are freed. However, we have no way to cancel
 778                 * the packet that we have passed to IrLAP. So, if a packet
 779                 * remains in IrLAP (retry on the link or else) after we
 780                 * close the socket, we are dead !
 781                 * Jean II */
 782                if (skb->sk != NULL) {
 783                        /* IrSOCK application, IrOBEX, ... */
 784                        skb_orphan(skb);
 785                }
 786                        /* IrCOMM over IrTTP, IrLAN, ... */
 787
 788                /* Pass the skb to IrLMP - done */
 789                irlmp_data_request(self->lsap, skb);
 790                self->stats.tx_packets++;
 791        }
 792
 793        /* Check if we can accept more frames from client.
 794         * We don't want to wait until the todo timer to do that, and we
 795         * can't use tasklets (grr...), so we are obliged to give control
 796         * to client. That's ok, this test will be true not too often
 797         * (max once per LAP window) and we are called from places
 798         * where we can spend a bit of time doing stuff. - Jean II */
 799        if ((self->tx_sdu_busy) &&
 800            (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
 801            (!self->close_pend))
 802        {
 803                if (self->notify.flow_indication)
 804                        self->notify.flow_indication(self->notify.instance,
 805                                                     self, FLOW_START);
 806
 807                /* self->tx_sdu_busy is the state of the client.
 808                 * We don't really have a race here, but it's always safer
 809                 * to update our state after the client - Jean II */
 810                self->tx_sdu_busy = FALSE;
 811        }
 812
 813        /* Reset lock */
 814        self->tx_queue_lock = 0;
 815}
 816
 817/*
 818 * Function irttp_give_credit (self)
 819 *
 820 *    Send a dataless flowdata TTP-PDU and give available credit to peer
 821 *    TSAP
 822 */
 823static inline void irttp_give_credit(struct tsap_cb *self)
 824{
 825        struct sk_buff *tx_skb = NULL;
 826        unsigned long flags;
 827        int n;
 828
 829        IRDA_ASSERT(self != NULL, return;);
 830        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
 831
 832        IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
 833                   __func__,
 834                   self->send_credit, self->avail_credit, self->remote_credit);
 835
 836        /* Give credit to peer */
 837        tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
 838        if (!tx_skb)
 839                return;
 840
 841        /* Reserve space for LMP, and LAP header */
 842        skb_reserve(tx_skb, LMP_MAX_HEADER);
 843
 844        /*
 845         *  Since we can transmit and receive frames concurrently,
 846         *  the code below is a critical region and we must assure that
 847         *  nobody messes with the credits while we update them.
 848         */
 849        spin_lock_irqsave(&self->lock, flags);
 850
 851        n = self->avail_credit;
 852        self->avail_credit = 0;
 853
 854        /* Only space for 127 credits in frame */
 855        if (n > 127) {
 856                self->avail_credit = n - 127;
 857                n = 127;
 858        }
 859        self->remote_credit += n;
 860
 861        spin_unlock_irqrestore(&self->lock, flags);
 862
 863        skb_put(tx_skb, 1);
 864        tx_skb->data[0] = (__u8) (n & 0x7f);
 865
 866        irlmp_data_request(self->lsap, tx_skb);
 867        self->stats.tx_packets++;
 868}
 869
 870/*
 871 * Function irttp_udata_indication (instance, sap, skb)
 872 *
 873 *    Received some unit-data (unreliable)
 874 *
 875 */
 876static int irttp_udata_indication(void *instance, void *sap,
 877                                  struct sk_buff *skb)
 878{
 879        struct tsap_cb *self;
 880        int err;
 881
 882        IRDA_DEBUG(4, "%s()\n", __func__);
 883
 884        self = instance;
 885
 886        IRDA_ASSERT(self != NULL, return -1;);
 887        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
 888        IRDA_ASSERT(skb != NULL, return -1;);
 889
 890        self->stats.rx_packets++;
 891
 892        /* Just pass data to layer above */
 893        if (self->notify.udata_indication) {
 894                err = self->notify.udata_indication(self->notify.instance,
 895                                                    self,skb);
 896                /* Same comment as in irttp_do_data_indication() */
 897                if (!err)
 898                        return 0;
 899        }
 900        /* Either no handler, or handler returns an error */
 901        dev_kfree_skb(skb);
 902
 903        return 0;
 904}
 905
 906/*
 907 * Function irttp_data_indication (instance, sap, skb)
 908 *
 909 *    Receive segment from IrLMP.
 910 *
 911 */
 912static int irttp_data_indication(void *instance, void *sap,
 913                                 struct sk_buff *skb)
 914{
 915        struct tsap_cb *self;
 916        unsigned long flags;
 917        int n;
 918
 919        self = instance;
 920
 921        n = skb->data[0] & 0x7f;     /* Extract the credits */
 922
 923        self->stats.rx_packets++;
 924
 925        /*  Deal with inbound credit
 926         *  Since we can transmit and receive frames concurrently,
 927         *  the code below is a critical region and we must assure that
 928         *  nobody messes with the credits while we update them.
 929         */
 930        spin_lock_irqsave(&self->lock, flags);
 931        self->send_credit += n;
 932        if (skb->len > 1)
 933                self->remote_credit--;
 934        spin_unlock_irqrestore(&self->lock, flags);
 935
 936        /*
 937         *  Data or dataless packet? Dataless frames contains only the
 938         *  TTP_HEADER.
 939         */
 940        if (skb->len > 1) {
 941                /*
 942                 *  We don't remove the TTP header, since we must preserve the
 943                 *  more bit, so the defragment routing knows what to do
 944                 */
 945                skb_queue_tail(&self->rx_queue, skb);
 946        } else {
 947                /* Dataless flowdata TTP-PDU */
 948                dev_kfree_skb(skb);
 949        }
 950
 951
 952        /* Push data to the higher layer.
 953         * We do it synchronously because running the todo timer for each
 954         * receive packet would be too much overhead and latency.
 955         * By passing control to the higher layer, we run the risk that
 956         * it may take time or grab a lock. Most often, the higher layer
 957         * will only put packet in a queue.
 958         * Anyway, packets are only dripping through the IrDA, so we can
 959         * have time before the next packet.
 960         * Further, we are run from NET_BH, so the worse that can happen is
 961         * us missing the optimal time to send back the PF bit in LAP.
 962         * Jean II */
 963        irttp_run_rx_queue(self);
 964
 965        /* We now give credits to peer in irttp_run_rx_queue().
 966         * We need to send credit *NOW*, otherwise we are going
 967         * to miss the next Tx window. The todo timer may take
 968         * a while before it's run... - Jean II */
 969
 970        /*
 971         * If the peer device has given us some credits and we didn't have
 972         * anyone from before, then we need to shedule the tx queue.
 973         * We need to do that because our Tx have stopped (so we may not
 974         * get any LAP flow indication) and the user may be stopped as
 975         * well. - Jean II
 976         */
 977        if (self->send_credit == n) {
 978                /* Restart pushing stuff to LAP */
 979                irttp_run_tx_queue(self);
 980                /* Note : we don't want to schedule the todo timer
 981                 * because it has horrible latency. No tasklets
 982                 * because the tasklet API is broken. - Jean II */
 983        }
 984
 985        return 0;
 986}
 987
 988/*
 989 * Function irttp_status_indication (self, reason)
 990 *
 991 *    Status_indication, just pass to the higher layer...
 992 *
 993 */
 994static void irttp_status_indication(void *instance,
 995                                    LINK_STATUS link, LOCK_STATUS lock)
 996{
 997        struct tsap_cb *self;
 998
 999        IRDA_DEBUG(4, "%s()\n", __func__);
1000
1001        self = instance;
1002
1003        IRDA_ASSERT(self != NULL, return;);
1004        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1005
1006        /* Check if client has already closed the TSAP and gone away */
1007        if (self->close_pend)
1008                return;
1009
1010        /*
1011         *  Inform service user if he has requested it
1012         */
1013        if (self->notify.status_indication != NULL)
1014                self->notify.status_indication(self->notify.instance,
1015                                               link, lock);
1016        else
1017                IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1018}
1019
1020/*
1021 * Function irttp_flow_indication (self, reason)
1022 *
1023 *    Flow_indication : IrLAP tells us to send more data.
1024 *
1025 */
1026static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1027{
1028        struct tsap_cb *self;
1029
1030        self = instance;
1031
1032        IRDA_ASSERT(self != NULL, return;);
1033        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1034
1035        IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1036
1037        /* We are "polled" directly from LAP, and the LAP want to fill
1038         * its Tx window. We want to do our best to send it data, so that
1039         * we maximise the window. On the other hand, we want to limit the
1040         * amount of work here so that LAP doesn't hang forever waiting
1041         * for packets. - Jean II */
1042
1043        /* Try to send some packets. Currently, LAP calls us every time
1044         * there is one free slot, so we will send only one packet.
1045         * This allow the scheduler to do its round robin - Jean II */
1046        irttp_run_tx_queue(self);
1047
1048        /* Note regarding the interraction with higher layer.
1049         * irttp_run_tx_queue() may call the client when its queue
1050         * start to empty, via notify.flow_indication(). Initially.
1051         * I wanted this to happen in a tasklet, to avoid client
1052         * grabbing the CPU, but we can't use tasklets safely. And timer
1053         * is definitely too slow.
1054         * This will happen only once per LAP window, and usually at
1055         * the third packet (unless window is smaller). LAP is still
1056         * doing mtt and sending first packet so it's sort of OK
1057         * to do that. Jean II */
1058
1059        /* If we need to send disconnect. try to do it now */
1060        if(self->disconnect_pend)
1061                irttp_start_todo_timer(self, 0);
1062}
1063
1064/*
1065 * Function irttp_flow_request (self, command)
1066 *
1067 *    This function could be used by the upper layers to tell IrTTP to stop
1068 *    delivering frames if the receive queues are starting to get full, or
1069 *    to tell IrTTP to start delivering frames again.
1070 */
1071void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1072{
1073        IRDA_DEBUG(1, "%s()\n", __func__);
1074
1075        IRDA_ASSERT(self != NULL, return;);
1076        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1077
1078        switch (flow) {
1079        case FLOW_STOP:
1080                IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1081                self->rx_sdu_busy = TRUE;
1082                break;
1083        case FLOW_START:
1084                IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1085                self->rx_sdu_busy = FALSE;
1086
1087                /* Client say he can accept more data, try to free our
1088                 * queues ASAP - Jean II */
1089                irttp_run_rx_queue(self);
1090
1091                break;
1092        default:
1093                IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1094        }
1095}
1096EXPORT_SYMBOL(irttp_flow_request);
1097
1098/*
1099 * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1100 *
1101 *    Try to connect to remote destination TSAP selector
1102 *
1103 */
1104int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1105                          __u32 saddr, __u32 daddr,
1106                          struct qos_info *qos, __u32 max_sdu_size,
1107                          struct sk_buff *userdata)
1108{
1109        struct sk_buff *tx_skb;
1110        __u8 *frame;
1111        __u8 n;
1112
1113        IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1114
1115        IRDA_ASSERT(self != NULL, return -EBADR;);
1116        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1117
1118        if (self->connected) {
1119                if(userdata)
1120                        dev_kfree_skb(userdata);
1121                return -EISCONN;
1122        }
1123
1124        /* Any userdata supplied? */
1125        if (userdata == NULL) {
1126                tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1127                                   GFP_ATOMIC);
1128                if (!tx_skb)
1129                        return -ENOMEM;
1130
1131                /* Reserve space for MUX_CONTROL and LAP header */
1132                skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1133        } else {
1134                tx_skb = userdata;
1135                /*
1136                 *  Check that the client has reserved enough space for
1137                 *  headers
1138                 */
1139                IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1140                        { dev_kfree_skb(userdata); return -1; } );
1141        }
1142
1143        /* Initialize connection parameters */
1144        self->connected = FALSE;
1145        self->avail_credit = 0;
1146        self->rx_max_sdu_size = max_sdu_size;
1147        self->rx_sdu_size = 0;
1148        self->rx_sdu_busy = FALSE;
1149        self->dtsap_sel = dtsap_sel;
1150
1151        n = self->initial_credit;
1152
1153        self->remote_credit = 0;
1154        self->send_credit = 0;
1155
1156        /*
1157         *  Give away max 127 credits for now
1158         */
1159        if (n > 127) {
1160                self->avail_credit=n-127;
1161                n = 127;
1162        }
1163
1164        self->remote_credit = n;
1165
1166        /* SAR enabled? */
1167        if (max_sdu_size > 0) {
1168                IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1169                        { dev_kfree_skb(tx_skb); return -1; } );
1170
1171                /* Insert SAR parameters */
1172                frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1173
1174                frame[0] = TTP_PARAMETERS | n;
1175                frame[1] = 0x04; /* Length */
1176                frame[2] = 0x01; /* MaxSduSize */
1177                frame[3] = 0x02; /* Value length */
1178
1179                put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1180                              (__be16 *)(frame+4));
1181        } else {
1182                /* Insert plain TTP header */
1183                frame = skb_push(tx_skb, TTP_HEADER);
1184
1185                /* Insert initial credit in frame */
1186                frame[0] = n & 0x7f;
1187        }
1188
1189        /* Connect with IrLMP. No QoS parameters for now */
1190        return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1191                                     tx_skb);
1192}
1193EXPORT_SYMBOL(irttp_connect_request);
1194
1195/*
1196 * Function irttp_connect_confirm (handle, qos, skb)
1197 *
1198 *    Service user confirms TSAP connection with peer.
1199 *
1200 */
1201static void irttp_connect_confirm(void *instance, void *sap,
1202                                  struct qos_info *qos, __u32 max_seg_size,
1203                                  __u8 max_header_size, struct sk_buff *skb)
1204{
1205        struct tsap_cb *self;
1206        int parameters;
1207        int ret;
1208        __u8 plen;
1209        __u8 n;
1210
1211        IRDA_DEBUG(4, "%s()\n", __func__);
1212
1213        self = instance;
1214
1215        IRDA_ASSERT(self != NULL, return;);
1216        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1217        IRDA_ASSERT(skb != NULL, return;);
1218
1219        self->max_seg_size = max_seg_size - TTP_HEADER;
1220        self->max_header_size = max_header_size + TTP_HEADER;
1221
1222        /*
1223         *  Check if we have got some QoS parameters back! This should be the
1224         *  negotiated QoS for the link.
1225         */
1226        if (qos) {
1227                IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1228                       qos->baud_rate.bits);
1229                IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1230                       qos->baud_rate.value);
1231        }
1232
1233        n = skb->data[0] & 0x7f;
1234
1235        IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1236
1237        self->send_credit = n;
1238        self->tx_max_sdu_size = 0;
1239        self->connected = TRUE;
1240
1241        parameters = skb->data[0] & 0x80;
1242
1243        IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1244        skb_pull(skb, TTP_HEADER);
1245
1246        if (parameters) {
1247                plen = skb->data[0];
1248
1249                ret = irda_param_extract_all(self, skb->data+1,
1250                                             IRDA_MIN(skb->len-1, plen),
1251                                             &param_info);
1252
1253                /* Any errors in the parameter list? */
1254                if (ret < 0) {
1255                        IRDA_WARNING("%s: error extracting parameters\n",
1256                                     __func__);
1257                        dev_kfree_skb(skb);
1258
1259                        /* Do not accept this connection attempt */
1260                        return;
1261                }
1262                /* Remove parameters */
1263                skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1264        }
1265
1266        IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1267              self->send_credit, self->avail_credit, self->remote_credit);
1268
1269        IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1270                   self->tx_max_sdu_size);
1271
1272        if (self->notify.connect_confirm) {
1273                self->notify.connect_confirm(self->notify.instance, self, qos,
1274                                             self->tx_max_sdu_size,
1275                                             self->max_header_size, skb);
1276        } else
1277                dev_kfree_skb(skb);
1278}
1279
1280/*
1281 * Function irttp_connect_indication (handle, skb)
1282 *
1283 *    Some other device is connecting to this TSAP
1284 *
1285 */
1286static void irttp_connect_indication(void *instance, void *sap,
1287                struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1288                struct sk_buff *skb)
1289{
1290        struct tsap_cb *self;
1291        struct lsap_cb *lsap;
1292        int parameters;
1293        int ret;
1294        __u8 plen;
1295        __u8 n;
1296
1297        self = instance;
1298
1299        IRDA_ASSERT(self != NULL, return;);
1300        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1301        IRDA_ASSERT(skb != NULL, return;);
1302
1303        lsap = sap;
1304
1305        self->max_seg_size = max_seg_size - TTP_HEADER;
1306        self->max_header_size = max_header_size+TTP_HEADER;
1307
1308        IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1309
1310        /* Need to update dtsap_sel if its equal to LSAP_ANY */
1311        self->dtsap_sel = lsap->dlsap_sel;
1312
1313        n = skb->data[0] & 0x7f;
1314
1315        self->send_credit = n;
1316        self->tx_max_sdu_size = 0;
1317
1318        parameters = skb->data[0] & 0x80;
1319
1320        IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1321        skb_pull(skb, TTP_HEADER);
1322
1323        if (parameters) {
1324                plen = skb->data[0];
1325
1326                ret = irda_param_extract_all(self, skb->data+1,
1327                                             IRDA_MIN(skb->len-1, plen),
1328                                             &param_info);
1329
1330                /* Any errors in the parameter list? */
1331                if (ret < 0) {
1332                        IRDA_WARNING("%s: error extracting parameters\n",
1333                                     __func__);
1334                        dev_kfree_skb(skb);
1335
1336                        /* Do not accept this connection attempt */
1337                        return;
1338                }
1339
1340                /* Remove parameters */
1341                skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1342        }
1343
1344        if (self->notify.connect_indication) {
1345                self->notify.connect_indication(self->notify.instance, self,
1346                                                qos, self->tx_max_sdu_size,
1347                                                self->max_header_size, skb);
1348        } else
1349                dev_kfree_skb(skb);
1350}
1351
1352/*
1353 * Function irttp_connect_response (handle, userdata)
1354 *
1355 *    Service user is accepting the connection, just pass it down to
1356 *    IrLMP!
1357 *
1358 */
1359int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1360                           struct sk_buff *userdata)
1361{
1362        struct sk_buff *tx_skb;
1363        __u8 *frame;
1364        int ret;
1365        __u8 n;
1366
1367        IRDA_ASSERT(self != NULL, return -1;);
1368        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1369
1370        IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1371                   self->stsap_sel);
1372
1373        /* Any userdata supplied? */
1374        if (userdata == NULL) {
1375                tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1376                                   GFP_ATOMIC);
1377                if (!tx_skb)
1378                        return -ENOMEM;
1379
1380                /* Reserve space for MUX_CONTROL and LAP header */
1381                skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1382        } else {
1383                tx_skb = userdata;
1384                /*
1385                 *  Check that the client has reserved enough space for
1386                 *  headers
1387                 */
1388                IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1389                        { dev_kfree_skb(userdata); return -1; } );
1390        }
1391
1392        self->avail_credit = 0;
1393        self->remote_credit = 0;
1394        self->rx_max_sdu_size = max_sdu_size;
1395        self->rx_sdu_size = 0;
1396        self->rx_sdu_busy = FALSE;
1397
1398        n = self->initial_credit;
1399
1400        /* Frame has only space for max 127 credits (7 bits) */
1401        if (n > 127) {
1402                self->avail_credit = n - 127;
1403                n = 127;
1404        }
1405
1406        self->remote_credit = n;
1407        self->connected = TRUE;
1408
1409        /* SAR enabled? */
1410        if (max_sdu_size > 0) {
1411                IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1412                        { dev_kfree_skb(tx_skb); return -1; } );
1413
1414                /* Insert TTP header with SAR parameters */
1415                frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1416
1417                frame[0] = TTP_PARAMETERS | n;
1418                frame[1] = 0x04; /* Length */
1419
1420                /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1421/*                                TTP_SAR_HEADER, &param_info) */
1422
1423                frame[2] = 0x01; /* MaxSduSize */
1424                frame[3] = 0x02; /* Value length */
1425
1426                put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1427                              (__be16 *)(frame+4));
1428        } else {
1429                /* Insert TTP header */
1430                frame = skb_push(tx_skb, TTP_HEADER);
1431
1432                frame[0] = n & 0x7f;
1433        }
1434
1435        ret = irlmp_connect_response(self->lsap, tx_skb);
1436
1437        return ret;
1438}
1439EXPORT_SYMBOL(irttp_connect_response);
1440
1441/*
1442 * Function irttp_dup (self, instance)
1443 *
1444 *    Duplicate TSAP, can be used by servers to confirm a connection on a
1445 *    new TSAP so it can keep listening on the old one.
1446 */
1447struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1448{
1449        struct tsap_cb *new;
1450        unsigned long flags;
1451
1452        IRDA_DEBUG(1, "%s()\n", __func__);
1453
1454        /* Protect our access to the old tsap instance */
1455        spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1456
1457        /* Find the old instance */
1458        if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1459                IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1460                spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1461                return NULL;
1462        }
1463
1464        /* Allocate a new instance */
1465        new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
1466        if (!new) {
1467                IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1468                spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1469                return NULL;
1470        }
1471        spin_lock_init(&new->lock);
1472
1473        /* We don't need the old instance any more */
1474        spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1475
1476        /* Try to dup the LSAP (may fail if we were too slow) */
1477        new->lsap = irlmp_dup(orig->lsap, new);
1478        if (!new->lsap) {
1479                IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1480                kfree(new);
1481                return NULL;
1482        }
1483
1484        /* Not everything should be copied */
1485        new->notify.instance = instance;
1486
1487        /* Initialize internal objects */
1488        irttp_init_tsap(new);
1489
1490        /* This is locked */
1491        hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1492
1493        return new;
1494}
1495EXPORT_SYMBOL(irttp_dup);
1496
1497/*
1498 * Function irttp_disconnect_request (self)
1499 *
1500 *    Close this connection please! If priority is high, the queued data
1501 *    segments, if any, will be deallocated first
1502 *
1503 */
1504int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1505                             int priority)
1506{
1507        int ret;
1508
1509        IRDA_ASSERT(self != NULL, return -1;);
1510        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1511
1512        /* Already disconnected? */
1513        if (!self->connected) {
1514                IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1515                if (userdata)
1516                        dev_kfree_skb(userdata);
1517                return -1;
1518        }
1519
1520        /* Disconnect already pending ?
1521         * We need to use an atomic operation to prevent reentry. This
1522         * function may be called from various context, like user, timer
1523         * for following a disconnect_indication() (i.e. net_bh).
1524         * Jean II */
1525        if(test_and_set_bit(0, &self->disconnect_pend)) {
1526                IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1527                           __func__);
1528                if (userdata)
1529                        dev_kfree_skb(userdata);
1530
1531                /* Try to make some progress */
1532                irttp_run_tx_queue(self);
1533                return -1;
1534        }
1535
1536        /*
1537         *  Check if there is still data segments in the transmit queue
1538         */
1539        if (!skb_queue_empty(&self->tx_queue)) {
1540                if (priority == P_HIGH) {
1541                        /*
1542                         *  No need to send the queued data, if we are
1543                         *  disconnecting right now since the data will
1544                         *  not have any usable connection to be sent on
1545                         */
1546                        IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1547                        irttp_flush_queues(self);
1548                } else if (priority == P_NORMAL) {
1549                        /*
1550                         *  Must delay disconnect until after all data segments
1551                         *  have been sent and the tx_queue is empty
1552                         */
1553                        /* We'll reuse this one later for the disconnect */
1554                        self->disconnect_skb = userdata;  /* May be NULL */
1555
1556                        irttp_run_tx_queue(self);
1557
1558                        irttp_start_todo_timer(self, HZ/10);
1559                        return -1;
1560                }
1561        }
1562        /* Note : we don't need to check if self->rx_queue is full and the
1563         * state of self->rx_sdu_busy because the disconnect response will
1564         * be sent at the LMP level (so even if the peer has its Tx queue
1565         * full of data). - Jean II */
1566
1567        IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1568        self->connected = FALSE;
1569
1570        if (!userdata) {
1571                struct sk_buff *tx_skb;
1572                tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1573                if (!tx_skb)
1574                        return -ENOMEM;
1575
1576                /*
1577                 *  Reserve space for MUX and LAP header
1578                 */
1579                skb_reserve(tx_skb, LMP_MAX_HEADER);
1580
1581                userdata = tx_skb;
1582        }
1583        ret = irlmp_disconnect_request(self->lsap, userdata);
1584
1585        /* The disconnect is no longer pending */
1586        clear_bit(0, &self->disconnect_pend);   /* FALSE */
1587
1588        return ret;
1589}
1590EXPORT_SYMBOL(irttp_disconnect_request);
1591
1592/*
1593 * Function irttp_disconnect_indication (self, reason)
1594 *
1595 *    Disconnect indication, TSAP disconnected by peer?
1596 *
1597 */
1598static void irttp_disconnect_indication(void *instance, void *sap,
1599                LM_REASON reason, struct sk_buff *skb)
1600{
1601        struct tsap_cb *self;
1602
1603        IRDA_DEBUG(4, "%s()\n", __func__);
1604
1605        self = instance;
1606
1607        IRDA_ASSERT(self != NULL, return;);
1608        IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1609
1610        /* Prevent higher layer to send more data */
1611        self->connected = FALSE;
1612
1613        /* Check if client has already tried to close the TSAP */
1614        if (self->close_pend) {
1615                /* In this case, the higher layer is probably gone. Don't
1616                 * bother it and clean up the remains - Jean II */
1617                if (skb)
1618                        dev_kfree_skb(skb);
1619                irttp_close_tsap(self);
1620                return;
1621        }
1622
1623        /* If we are here, we assume that is the higher layer is still
1624         * waiting for the disconnect notification and able to process it,
1625         * even if he tried to disconnect. Otherwise, it would have already
1626         * attempted to close the tsap and self->close_pend would be TRUE.
1627         * Jean II */
1628
1629        /* No need to notify the client if has already tried to disconnect */
1630        if(self->notify.disconnect_indication)
1631                self->notify.disconnect_indication(self->notify.instance, self,
1632                                                   reason, skb);
1633        else
1634                if (skb)
1635                        dev_kfree_skb(skb);
1636}
1637
1638/*
1639 * Function irttp_do_data_indication (self, skb)
1640 *
1641 *    Try to deliver reassembled skb to layer above, and requeue it if that
1642 *    for some reason should fail. We mark rx sdu as busy to apply back
1643 *    pressure is necessary.
1644 */
1645static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1646{
1647        int err;
1648
1649        /* Check if client has already closed the TSAP and gone away */
1650        if (self->close_pend) {
1651                dev_kfree_skb(skb);
1652                return;
1653        }
1654
1655        err = self->notify.data_indication(self->notify.instance, self, skb);
1656
1657        /* Usually the layer above will notify that it's input queue is
1658         * starting to get filled by using the flow request, but this may
1659         * be difficult, so it can instead just refuse to eat it and just
1660         * give an error back
1661         */
1662        if (err) {
1663                IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1664
1665                /* Make sure we take a break */
1666                self->rx_sdu_busy = TRUE;
1667
1668                /* Need to push the header in again */
1669                skb_push(skb, TTP_HEADER);
1670                skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1671
1672                /* Put skb back on queue */
1673                skb_queue_head(&self->rx_queue, skb);
1674        }
1675}
1676
1677/*
1678 * Function irttp_run_rx_queue (self)
1679 *
1680 *     Check if we have any frames to be transmitted, or if we have any
1681 *     available credit to give away.
1682 */
1683static void irttp_run_rx_queue(struct tsap_cb *self)
1684{
1685        struct sk_buff *skb;
1686        int more = 0;
1687
1688        IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1689                   self->send_credit, self->avail_credit, self->remote_credit);
1690
1691        /* Get exclusive access to the rx queue, otherwise don't touch it */
1692        if (irda_lock(&self->rx_queue_lock) == FALSE)
1693                return;
1694
1695        /*
1696         *  Reassemble all frames in receive queue and deliver them
1697         */
1698        while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1699                /* This bit will tell us if it's the last fragment or not */
1700                more = skb->data[0] & 0x80;
1701
1702                /* Remove TTP header */
1703                skb_pull(skb, TTP_HEADER);
1704
1705                /* Add the length of the remaining data */
1706                self->rx_sdu_size += skb->len;
1707
1708                /*
1709                 * If SAR is disabled, or user has requested no reassembly
1710                 * of received fragments then we just deliver them
1711                 * immediately. This can be requested by clients that
1712                 * implements byte streams without any message boundaries
1713                 */
1714                if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1715                        irttp_do_data_indication(self, skb);
1716                        self->rx_sdu_size = 0;
1717
1718                        continue;
1719                }
1720
1721                /* Check if this is a fragment, and not the last fragment */
1722                if (more) {
1723                        /*
1724                         *  Queue the fragment if we still are within the
1725                         *  limits of the maximum size of the rx_sdu
1726                         */
1727                        if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1728                                IRDA_DEBUG(4, "%s(), queueing frag\n",
1729                                           __func__);
1730                                skb_queue_tail(&self->rx_fragments, skb);
1731                        } else {
1732                                /* Free the part of the SDU that is too big */
1733                                dev_kfree_skb(skb);
1734                        }
1735                        continue;
1736                }
1737                /*
1738                 *  This is the last fragment, so time to reassemble!
1739                 */
1740                if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1741                    (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1742                {
1743                        /*
1744                         * A little optimizing. Only queue the fragment if
1745                         * there are other fragments. Since if this is the
1746                         * last and only fragment, there is no need to
1747                         * reassemble :-)
1748                         */
1749                        if (!skb_queue_empty(&self->rx_fragments)) {
1750                                skb_queue_tail(&self->rx_fragments,
1751                                               skb);
1752
1753                                skb = irttp_reassemble_skb(self);
1754                        }
1755
1756                        /* Now we can deliver the reassembled skb */
1757                        irttp_do_data_indication(self, skb);
1758                } else {
1759                        IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1760
1761                        /* Free the part of the SDU that is too big */
1762                        dev_kfree_skb(skb);
1763
1764                        /* Deliver only the valid but truncated part of SDU */
1765                        skb = irttp_reassemble_skb(self);
1766
1767                        irttp_do_data_indication(self, skb);
1768                }
1769                self->rx_sdu_size = 0;
1770        }
1771
1772        /*
1773         * It's not trivial to keep track of how many credits are available
1774         * by incrementing at each packet, because delivery may fail
1775         * (irttp_do_data_indication() may requeue the frame) and because
1776         * we need to take care of fragmentation.
1777         * We want the other side to send up to initial_credit packets.
1778         * We have some frames in our queues, and we have already allowed it
1779         * to send remote_credit.
1780         * No need to spinlock, write is atomic and self correcting...
1781         * Jean II
1782         */
1783        self->avail_credit = (self->initial_credit -
1784                              (self->remote_credit +
1785                               skb_queue_len(&self->rx_queue) +
1786                               skb_queue_len(&self->rx_fragments)));
1787
1788        /* Do we have too much credits to send to peer ? */
1789        if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1790            (self->avail_credit > 0)) {
1791                /* Send explicit credit frame */
1792                irttp_give_credit(self);
1793                /* Note : do *NOT* check if tx_queue is non-empty, that
1794                 * will produce deadlocks. I repeat : send a credit frame
1795                 * even if we have something to send in our Tx queue.
1796                 * If we have credits, it means that our Tx queue is blocked.
1797                 *
1798                 * Let's suppose the peer can't keep up with our Tx. He will
1799                 * flow control us by not sending us any credits, and we
1800                 * will stop Tx and start accumulating credits here.
1801                 * Up to the point where the peer will stop its Tx queue,
1802                 * for lack of credits.
1803                 * Let's assume the peer application is single threaded.
1804                 * It will block on Tx and never consume any Rx buffer.
1805                 * Deadlock. Guaranteed. - Jean II
1806                 */
1807        }
1808
1809        /* Reset lock */
1810        self->rx_queue_lock = 0;
1811}
1812
1813#ifdef CONFIG_PROC_FS
1814struct irttp_iter_state {
1815        int id;
1816};
1817
1818static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1819{
1820        struct irttp_iter_state *iter = seq->private;
1821        struct tsap_cb *self;
1822
1823        /* Protect our access to the tsap list */
1824        spin_lock_irq(&irttp->tsaps->hb_spinlock);
1825        iter->id = 0;
1826
1827        for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1828             self != NULL;
1829             self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1830                if (iter->id == *pos)
1831                        break;
1832                ++iter->id;
1833        }
1834
1835        return self;
1836}
1837
1838static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1839{
1840        struct irttp_iter_state *iter = seq->private;
1841
1842        ++*pos;
1843        ++iter->id;
1844        return (void *) hashbin_get_next(irttp->tsaps);
1845}
1846
1847static void irttp_seq_stop(struct seq_file *seq, void *v)
1848{
1849        spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1850}
1851
1852static int irttp_seq_show(struct seq_file *seq, void *v)
1853{
1854        const struct irttp_iter_state *iter = seq->private;
1855        const struct tsap_cb *self = v;
1856
1857        seq_printf(seq, "TSAP %d, ", iter->id);
1858        seq_printf(seq, "stsap_sel: %02x, ",
1859                   self->stsap_sel);
1860        seq_printf(seq, "dtsap_sel: %02x\n",
1861                   self->dtsap_sel);
1862        seq_printf(seq, "  connected: %s, ",
1863                   self->connected? "TRUE":"FALSE");
1864        seq_printf(seq, "avail credit: %d, ",
1865                   self->avail_credit);
1866        seq_printf(seq, "remote credit: %d, ",
1867                   self->remote_credit);
1868        seq_printf(seq, "send credit: %d\n",
1869                   self->send_credit);
1870        seq_printf(seq, "  tx packets: %lu, ",
1871                   self->stats.tx_packets);
1872        seq_printf(seq, "rx packets: %lu, ",
1873                   self->stats.rx_packets);
1874        seq_printf(seq, "tx_queue len: %u ",
1875                   skb_queue_len(&self->tx_queue));
1876        seq_printf(seq, "rx_queue len: %u\n",
1877                   skb_queue_len(&self->rx_queue));
1878        seq_printf(seq, "  tx_sdu_busy: %s, ",
1879                   self->tx_sdu_busy? "TRUE":"FALSE");
1880        seq_printf(seq, "rx_sdu_busy: %s\n",
1881                   self->rx_sdu_busy? "TRUE":"FALSE");
1882        seq_printf(seq, "  max_seg_size: %u, ",
1883                   self->max_seg_size);
1884        seq_printf(seq, "tx_max_sdu_size: %u, ",
1885                   self->tx_max_sdu_size);
1886        seq_printf(seq, "rx_max_sdu_size: %u\n",
1887                   self->rx_max_sdu_size);
1888
1889        seq_printf(seq, "  Used by (%s)\n\n",
1890                   self->notify.name);
1891        return 0;
1892}
1893
1894static const struct seq_operations irttp_seq_ops = {
1895        .start  = irttp_seq_start,
1896        .next   = irttp_seq_next,
1897        .stop   = irttp_seq_stop,
1898        .show   = irttp_seq_show,
1899};
1900
1901static int irttp_seq_open(struct inode *inode, struct file *file)
1902{
1903        return seq_open_private(file, &irttp_seq_ops,
1904                        sizeof(struct irttp_iter_state));
1905}
1906
1907const struct file_operations irttp_seq_fops = {
1908        .owner          = THIS_MODULE,
1909        .open           = irttp_seq_open,
1910        .read           = seq_read,
1911        .llseek         = seq_lseek,
1912        .release        = seq_release_private,
1913};
1914
1915#endif /* PROC_FS */
1916
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