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