net: irda: irttp: sync error paths of data- and udata-requests
[linux-2.6.git] / net / irda / irttp.c
1 /*********************************************************************
2  *
3  * Filename:      irttp.c
4  * Version:       1.2
5  * Description:   Tiny Transport Protocol (TTP) implementation
6  * Status:        Stable
7  * Author:        Dag Brattli <dagb@cs.uit.no>
8  * Created at:    Sun Aug 31 20:14:31 1997
9  * Modified at:   Wed Jan  5 11:31:27 2000
10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
11  *
12  *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
13  *     All Rights Reserved.
14  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
15  *
16  *     This program is free software; you can redistribute it and/or
17  *     modify it under the terms of the GNU General Public License as
18  *     published by the Free Software Foundation; either version 2 of
19  *     the License, or (at your option) any later version.
20  *
21  *     Neither Dag Brattli nor University of Tromsø admit liability nor
22  *     provide warranty for any of this software. This material is
23  *     provided "AS-IS" and at no charge.
24  *
25  ********************************************************************/
26
27 #include <linux/skbuff.h>
28 #include <linux/init.h>
29 #include <linux/fs.h>
30 #include <linux/seq_file.h>
31 #include <linux/slab.h>
32
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         int ret;
554
555         IRDA_ASSERT(self != NULL, return -1;);
556         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
557         IRDA_ASSERT(skb != NULL, return -1;);
558
559         IRDA_DEBUG(4, "%s()\n", __func__);
560
561         /* Take shortcut on zero byte packets */
562         if (skb->len == 0) {
563                 ret = 0;
564                 goto err;
565         }
566
567         /* Check that nothing bad happens */
568         if (!self->connected) {
569                 IRDA_WARNING("%s(), Not connected\n", __func__);
570                 ret = -ENOTCONN;
571                 goto err;
572         }
573
574         if (skb->len > self->max_seg_size) {
575                 IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
576                 ret = -EMSGSIZE;
577                 goto err;
578         }
579
580         irlmp_udata_request(self->lsap, skb);
581         self->stats.tx_packets++;
582
583         return 0;
584
585 err:
586         dev_kfree_skb(skb);
587         return ret;
588 }
589 EXPORT_SYMBOL(irttp_udata_request);
590
591
592 /*
593  * Function irttp_data_request (handle, skb)
594  *
595  *    Queue frame for transmission. If SAR is enabled, fragement the frame
596  *    and queue the fragments for transmission
597  */
598 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
599 {
600         __u8 *frame;
601         int ret;
602
603         IRDA_ASSERT(self != NULL, return -1;);
604         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
605         IRDA_ASSERT(skb != NULL, return -1;);
606
607         IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
608                    skb_queue_len(&self->tx_queue));
609
610         /* Take shortcut on zero byte packets */
611         if (skb->len == 0) {
612                 ret = 0;
613                 goto err;
614         }
615
616         /* Check that nothing bad happens */
617         if (!self->connected) {
618                 IRDA_WARNING("%s: Not connected\n", __func__);
619                 ret = -ENOTCONN;
620                 goto err;
621         }
622
623         /*
624          *  Check if SAR is disabled, and the frame is larger than what fits
625          *  inside an IrLAP frame
626          */
627         if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
628                 IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
629                            __func__);
630                 ret = -EMSGSIZE;
631                 goto err;
632         }
633
634         /*
635          *  Check if SAR is enabled, and the frame is larger than the
636          *  TxMaxSduSize
637          */
638         if ((self->tx_max_sdu_size != 0) &&
639             (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
640             (skb->len > self->tx_max_sdu_size))
641         {
642                 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
643                            __func__);
644                 ret = -EMSGSIZE;
645                 goto err;
646         }
647         /*
648          *  Check if transmit queue is full
649          */
650         if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
651                 /*
652                  *  Give it a chance to empty itself
653                  */
654                 irttp_run_tx_queue(self);
655
656                 /* Drop packet. This error code should trigger the caller
657                  * to resend the data in the client code - Jean II */
658                 ret = -ENOBUFS;
659                 goto err;
660         }
661
662         /* Queue frame, or queue frame segments */
663         if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
664                 /* Queue frame */
665                 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
666                 frame = skb_push(skb, TTP_HEADER);
667                 frame[0] = 0x00; /* Clear more bit */
668
669                 skb_queue_tail(&self->tx_queue, skb);
670         } else {
671                 /*
672                  *  Fragment the frame, this function will also queue the
673                  *  fragments, we don't care about the fact the transmit
674                  *  queue may be overfilled by all the segments for a little
675                  *  while
676                  */
677                 irttp_fragment_skb(self, skb);
678         }
679
680         /* Check if we can accept more data from client */
681         if ((!self->tx_sdu_busy) &&
682             (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
683                 /* Tx queue filling up, so stop client. */
684                 if (self->notify.flow_indication) {
685                         self->notify.flow_indication(self->notify.instance,
686                                                      self, FLOW_STOP);
687                 }
688                 /* self->tx_sdu_busy is the state of the client.
689                  * Update state after notifying client to avoid
690                  * race condition with irttp_flow_indication().
691                  * If the queue empty itself after our test but before
692                  * we set the flag, we will fix ourselves below in
693                  * irttp_run_tx_queue().
694                  * Jean II */
695                 self->tx_sdu_busy = TRUE;
696         }
697
698         /* Try to make some progress */
699         irttp_run_tx_queue(self);
700
701         return 0;
702
703 err:
704         dev_kfree_skb(skb);
705         return ret;
706 }
707 EXPORT_SYMBOL(irttp_data_request);
708
709 /*
710  * Function irttp_run_tx_queue (self)
711  *
712  *    Transmit packets queued for transmission (if possible)
713  *
714  */
715 static void irttp_run_tx_queue(struct tsap_cb *self)
716 {
717         struct sk_buff *skb;
718         unsigned long flags;
719         int n;
720
721         IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
722                    __func__,
723                    self->send_credit, skb_queue_len(&self->tx_queue));
724
725         /* Get exclusive access to the tx queue, otherwise don't touch it */
726         if (irda_lock(&self->tx_queue_lock) == FALSE)
727                 return;
728
729         /* Try to send out frames as long as we have credits
730          * and as long as LAP is not full. If LAP is full, it will
731          * poll us through irttp_flow_indication() - Jean II */
732         while ((self->send_credit > 0) &&
733                (!irlmp_lap_tx_queue_full(self->lsap)) &&
734                (skb = skb_dequeue(&self->tx_queue)))
735         {
736                 /*
737                  *  Since we can transmit and receive frames concurrently,
738                  *  the code below is a critical region and we must assure that
739                  *  nobody messes with the credits while we update them.
740                  */
741                 spin_lock_irqsave(&self->lock, flags);
742
743                 n = self->avail_credit;
744                 self->avail_credit = 0;
745
746                 /* Only room for 127 credits in frame */
747                 if (n > 127) {
748                         self->avail_credit = n-127;
749                         n = 127;
750                 }
751                 self->remote_credit += n;
752                 self->send_credit--;
753
754                 spin_unlock_irqrestore(&self->lock, flags);
755
756                 /*
757                  *  More bit must be set by the data_request() or fragment()
758                  *  functions
759                  */
760                 skb->data[0] |= (n & 0x7f);
761
762                 /* Detach from socket.
763                  * The current skb has a reference to the socket that sent
764                  * it (skb->sk). When we pass it to IrLMP, the skb will be
765                  * stored in in IrLAP (self->wx_list). When we are within
766                  * IrLAP, we lose the notion of socket, so we should not
767                  * have a reference to a socket. So, we drop it here.
768                  *
769                  * Why does it matter ?
770                  * When the skb is freed (kfree_skb), if it is associated
771                  * with a socket, it release buffer space on the socket
772                  * (through sock_wfree() and sock_def_write_space()).
773                  * If the socket no longer exist, we may crash. Hard.
774                  * When we close a socket, we make sure that associated packets
775                  * in IrTTP are freed. However, we have no way to cancel
776                  * the packet that we have passed to IrLAP. So, if a packet
777                  * remains in IrLAP (retry on the link or else) after we
778                  * close the socket, we are dead !
779                  * Jean II */
780                 if (skb->sk != NULL) {
781                         /* IrSOCK application, IrOBEX, ... */
782                         skb_orphan(skb);
783                 }
784                         /* IrCOMM over IrTTP, IrLAN, ... */
785
786                 /* Pass the skb to IrLMP - done */
787                 irlmp_data_request(self->lsap, skb);
788                 self->stats.tx_packets++;
789         }
790
791         /* Check if we can accept more frames from client.
792          * We don't want to wait until the todo timer to do that, and we
793          * can't use tasklets (grr...), so we are obliged to give control
794          * to client. That's ok, this test will be true not too often
795          * (max once per LAP window) and we are called from places
796          * where we can spend a bit of time doing stuff. - Jean II */
797         if ((self->tx_sdu_busy) &&
798             (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
799             (!self->close_pend))
800         {
801                 if (self->notify.flow_indication)
802                         self->notify.flow_indication(self->notify.instance,
803                                                      self, FLOW_START);
804
805                 /* self->tx_sdu_busy is the state of the client.
806                  * We don't really have a race here, but it's always safer
807                  * to update our state after the client - Jean II */
808                 self->tx_sdu_busy = FALSE;
809         }
810
811         /* Reset lock */
812         self->tx_queue_lock = 0;
813 }
814
815 /*
816  * Function irttp_give_credit (self)
817  *
818  *    Send a dataless flowdata TTP-PDU and give available credit to peer
819  *    TSAP
820  */
821 static inline void irttp_give_credit(struct tsap_cb *self)
822 {
823         struct sk_buff *tx_skb = NULL;
824         unsigned long flags;
825         int n;
826
827         IRDA_ASSERT(self != NULL, return;);
828         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
829
830         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
831                    __func__,
832                    self->send_credit, self->avail_credit, self->remote_credit);
833
834         /* Give credit to peer */
835         tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
836         if (!tx_skb)
837                 return;
838
839         /* Reserve space for LMP, and LAP header */
840         skb_reserve(tx_skb, LMP_MAX_HEADER);
841
842         /*
843          *  Since we can transmit and receive frames concurrently,
844          *  the code below is a critical region and we must assure that
845          *  nobody messes with the credits while we update them.
846          */
847         spin_lock_irqsave(&self->lock, flags);
848
849         n = self->avail_credit;
850         self->avail_credit = 0;
851
852         /* Only space for 127 credits in frame */
853         if (n > 127) {
854                 self->avail_credit = n - 127;
855                 n = 127;
856         }
857         self->remote_credit += n;
858
859         spin_unlock_irqrestore(&self->lock, flags);
860
861         skb_put(tx_skb, 1);
862         tx_skb->data[0] = (__u8) (n & 0x7f);
863
864         irlmp_data_request(self->lsap, tx_skb);
865         self->stats.tx_packets++;
866 }
867
868 /*
869  * Function irttp_udata_indication (instance, sap, skb)
870  *
871  *    Received some unit-data (unreliable)
872  *
873  */
874 static int irttp_udata_indication(void *instance, void *sap,
875                                   struct sk_buff *skb)
876 {
877         struct tsap_cb *self;
878         int err;
879
880         IRDA_DEBUG(4, "%s()\n", __func__);
881
882         self = (struct tsap_cb *) instance;
883
884         IRDA_ASSERT(self != NULL, return -1;);
885         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
886         IRDA_ASSERT(skb != NULL, return -1;);
887
888         self->stats.rx_packets++;
889
890         /* Just pass data to layer above */
891         if (self->notify.udata_indication) {
892                 err = self->notify.udata_indication(self->notify.instance,
893                                                     self,skb);
894                 /* Same comment as in irttp_do_data_indication() */
895                 if (!err)
896                         return 0;
897         }
898         /* Either no handler, or handler returns an error */
899         dev_kfree_skb(skb);
900
901         return 0;
902 }
903
904 /*
905  * Function irttp_data_indication (instance, sap, skb)
906  *
907  *    Receive segment from IrLMP.
908  *
909  */
910 static int irttp_data_indication(void *instance, void *sap,
911                                  struct sk_buff *skb)
912 {
913         struct tsap_cb *self;
914         unsigned long flags;
915         int n;
916
917         self = (struct tsap_cb *) instance;
918
919         n = skb->data[0] & 0x7f;     /* Extract the credits */
920
921         self->stats.rx_packets++;
922
923         /*  Deal with inbound credit
924          *  Since we can transmit and receive frames concurrently,
925          *  the code below is a critical region and we must assure that
926          *  nobody messes with the credits while we update them.
927          */
928         spin_lock_irqsave(&self->lock, flags);
929         self->send_credit += n;
930         if (skb->len > 1)
931                 self->remote_credit--;
932         spin_unlock_irqrestore(&self->lock, flags);
933
934         /*
935          *  Data or dataless packet? Dataless frames contains only the
936          *  TTP_HEADER.
937          */
938         if (skb->len > 1) {
939                 /*
940                  *  We don't remove the TTP header, since we must preserve the
941                  *  more bit, so the defragment routing knows what to do
942                  */
943                 skb_queue_tail(&self->rx_queue, skb);
944         } else {
945                 /* Dataless flowdata TTP-PDU */
946                 dev_kfree_skb(skb);
947         }
948
949
950         /* Push data to the higher layer.
951          * We do it synchronously because running the todo timer for each
952          * receive packet would be too much overhead and latency.
953          * By passing control to the higher layer, we run the risk that
954          * it may take time or grab a lock. Most often, the higher layer
955          * will only put packet in a queue.
956          * Anyway, packets are only dripping through the IrDA, so we can
957          * have time before the next packet.
958          * Further, we are run from NET_BH, so the worse that can happen is
959          * us missing the optimal time to send back the PF bit in LAP.
960          * Jean II */
961         irttp_run_rx_queue(self);
962
963         /* We now give credits to peer in irttp_run_rx_queue().
964          * We need to send credit *NOW*, otherwise we are going
965          * to miss the next Tx window. The todo timer may take
966          * a while before it's run... - Jean II */
967
968         /*
969          * If the peer device has given us some credits and we didn't have
970          * anyone from before, then we need to shedule the tx queue.
971          * We need to do that because our Tx have stopped (so we may not
972          * get any LAP flow indication) and the user may be stopped as
973          * well. - Jean II
974          */
975         if (self->send_credit == n) {
976                 /* Restart pushing stuff to LAP */
977                 irttp_run_tx_queue(self);
978                 /* Note : we don't want to schedule the todo timer
979                  * because it has horrible latency. No tasklets
980                  * because the tasklet API is broken. - Jean II */
981         }
982
983         return 0;
984 }
985
986 /*
987  * Function irttp_status_indication (self, reason)
988  *
989  *    Status_indication, just pass to the higher layer...
990  *
991  */
992 static void irttp_status_indication(void *instance,
993                                     LINK_STATUS link, LOCK_STATUS lock)
994 {
995         struct tsap_cb *self;
996
997         IRDA_DEBUG(4, "%s()\n", __func__);
998
999         self = (struct tsap_cb *) instance;
1000
1001         IRDA_ASSERT(self != NULL, return;);
1002         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1003
1004         /* Check if client has already closed the TSAP and gone away */
1005         if (self->close_pend)
1006                 return;
1007
1008         /*
1009          *  Inform service user if he has requested it
1010          */
1011         if (self->notify.status_indication != NULL)
1012                 self->notify.status_indication(self->notify.instance,
1013                                                link, lock);
1014         else
1015                 IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1016 }
1017
1018 /*
1019  * Function irttp_flow_indication (self, reason)
1020  *
1021  *    Flow_indication : IrLAP tells us to send more data.
1022  *
1023  */
1024 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1025 {
1026         struct tsap_cb *self;
1027
1028         self = (struct tsap_cb *) instance;
1029
1030         IRDA_ASSERT(self != NULL, return;);
1031         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1032
1033         IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1034
1035         /* We are "polled" directly from LAP, and the LAP want to fill
1036          * its Tx window. We want to do our best to send it data, so that
1037          * we maximise the window. On the other hand, we want to limit the
1038          * amount of work here so that LAP doesn't hang forever waiting
1039          * for packets. - Jean II */
1040
1041         /* Try to send some packets. Currently, LAP calls us every time
1042          * there is one free slot, so we will send only one packet.
1043          * This allow the scheduler to do its round robin - Jean II */
1044         irttp_run_tx_queue(self);
1045
1046         /* Note regarding the interraction with higher layer.
1047          * irttp_run_tx_queue() may call the client when its queue
1048          * start to empty, via notify.flow_indication(). Initially.
1049          * I wanted this to happen in a tasklet, to avoid client
1050          * grabbing the CPU, but we can't use tasklets safely. And timer
1051          * is definitely too slow.
1052          * This will happen only once per LAP window, and usually at
1053          * the third packet (unless window is smaller). LAP is still
1054          * doing mtt and sending first packet so it's sort of OK
1055          * to do that. Jean II */
1056
1057         /* If we need to send disconnect. try to do it now */
1058         if(self->disconnect_pend)
1059                 irttp_start_todo_timer(self, 0);
1060 }
1061
1062 /*
1063  * Function irttp_flow_request (self, command)
1064  *
1065  *    This function could be used by the upper layers to tell IrTTP to stop
1066  *    delivering frames if the receive queues are starting to get full, or
1067  *    to tell IrTTP to start delivering frames again.
1068  */
1069 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1070 {
1071         IRDA_DEBUG(1, "%s()\n", __func__);
1072
1073         IRDA_ASSERT(self != NULL, return;);
1074         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1075
1076         switch (flow) {
1077         case FLOW_STOP:
1078                 IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1079                 self->rx_sdu_busy = TRUE;
1080                 break;
1081         case FLOW_START:
1082                 IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1083                 self->rx_sdu_busy = FALSE;
1084
1085                 /* Client say he can accept more data, try to free our
1086                  * queues ASAP - Jean II */
1087                 irttp_run_rx_queue(self);
1088
1089                 break;
1090         default:
1091                 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1092         }
1093 }
1094 EXPORT_SYMBOL(irttp_flow_request);
1095
1096 /*
1097  * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1098  *
1099  *    Try to connect to remote destination TSAP selector
1100  *
1101  */
1102 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1103                           __u32 saddr, __u32 daddr,
1104                           struct qos_info *qos, __u32 max_sdu_size,
1105                           struct sk_buff *userdata)
1106 {
1107         struct sk_buff *tx_skb;
1108         __u8 *frame;
1109         __u8 n;
1110
1111         IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1112
1113         IRDA_ASSERT(self != NULL, return -EBADR;);
1114         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1115
1116         if (self->connected) {
1117                 if(userdata)
1118                         dev_kfree_skb(userdata);
1119                 return -EISCONN;
1120         }
1121
1122         /* Any userdata supplied? */
1123         if (userdata == NULL) {
1124                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1125                                    GFP_ATOMIC);
1126                 if (!tx_skb)
1127                         return -ENOMEM;
1128
1129                 /* Reserve space for MUX_CONTROL and LAP header */
1130                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1131         } else {
1132                 tx_skb = userdata;
1133                 /*
1134                  *  Check that the client has reserved enough space for
1135                  *  headers
1136                  */
1137                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1138                         { dev_kfree_skb(userdata); return -1; } );
1139         }
1140
1141         /* Initialize connection parameters */
1142         self->connected = FALSE;
1143         self->avail_credit = 0;
1144         self->rx_max_sdu_size = max_sdu_size;
1145         self->rx_sdu_size = 0;
1146         self->rx_sdu_busy = FALSE;
1147         self->dtsap_sel = dtsap_sel;
1148
1149         n = self->initial_credit;
1150
1151         self->remote_credit = 0;
1152         self->send_credit = 0;
1153
1154         /*
1155          *  Give away max 127 credits for now
1156          */
1157         if (n > 127) {
1158                 self->avail_credit=n-127;
1159                 n = 127;
1160         }
1161
1162         self->remote_credit = n;
1163
1164         /* SAR enabled? */
1165         if (max_sdu_size > 0) {
1166                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1167                         { dev_kfree_skb(tx_skb); return -1; } );
1168
1169                 /* Insert SAR parameters */
1170                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1171
1172                 frame[0] = TTP_PARAMETERS | n;
1173                 frame[1] = 0x04; /* Length */
1174                 frame[2] = 0x01; /* MaxSduSize */
1175                 frame[3] = 0x02; /* Value length */
1176
1177                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1178                               (__be16 *)(frame+4));
1179         } else {
1180                 /* Insert plain TTP header */
1181                 frame = skb_push(tx_skb, TTP_HEADER);
1182
1183                 /* Insert initial credit in frame */
1184                 frame[0] = n & 0x7f;
1185         }
1186
1187         /* Connect with IrLMP. No QoS parameters for now */
1188         return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1189                                      tx_skb);
1190 }
1191 EXPORT_SYMBOL(irttp_connect_request);
1192
1193 /*
1194  * Function irttp_connect_confirm (handle, qos, skb)
1195  *
1196  *    Sevice user confirms TSAP connection with peer.
1197  *
1198  */
1199 static void irttp_connect_confirm(void *instance, void *sap,
1200                                   struct qos_info *qos, __u32 max_seg_size,
1201                                   __u8 max_header_size, struct sk_buff *skb)
1202 {
1203         struct tsap_cb *self;
1204         int parameters;
1205         int ret;
1206         __u8 plen;
1207         __u8 n;
1208
1209         IRDA_DEBUG(4, "%s()\n", __func__);
1210
1211         self = (struct tsap_cb *) instance;
1212
1213         IRDA_ASSERT(self != NULL, return;);
1214         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1215         IRDA_ASSERT(skb != NULL, return;);
1216
1217         self->max_seg_size = max_seg_size - TTP_HEADER;
1218         self->max_header_size = max_header_size + TTP_HEADER;
1219
1220         /*
1221          *  Check if we have got some QoS parameters back! This should be the
1222          *  negotiated QoS for the link.
1223          */
1224         if (qos) {
1225                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1226                        qos->baud_rate.bits);
1227                 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1228                        qos->baud_rate.value);
1229         }
1230
1231         n = skb->data[0] & 0x7f;
1232
1233         IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1234
1235         self->send_credit = n;
1236         self->tx_max_sdu_size = 0;
1237         self->connected = TRUE;
1238
1239         parameters = skb->data[0] & 0x80;
1240
1241         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1242         skb_pull(skb, TTP_HEADER);
1243
1244         if (parameters) {
1245                 plen = skb->data[0];
1246
1247                 ret = irda_param_extract_all(self, skb->data+1,
1248                                              IRDA_MIN(skb->len-1, plen),
1249                                              &param_info);
1250
1251                 /* Any errors in the parameter list? */
1252                 if (ret < 0) {
1253                         IRDA_WARNING("%s: error extracting parameters\n",
1254                                      __func__);
1255                         dev_kfree_skb(skb);
1256
1257                         /* Do not accept this connection attempt */
1258                         return;
1259                 }
1260                 /* Remove parameters */
1261                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1262         }
1263
1264         IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1265               self->send_credit, self->avail_credit, self->remote_credit);
1266
1267         IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1268                    self->tx_max_sdu_size);
1269
1270         if (self->notify.connect_confirm) {
1271                 self->notify.connect_confirm(self->notify.instance, self, qos,
1272                                              self->tx_max_sdu_size,
1273                                              self->max_header_size, skb);
1274         } else
1275                 dev_kfree_skb(skb);
1276 }
1277
1278 /*
1279  * Function irttp_connect_indication (handle, skb)
1280  *
1281  *    Some other device is connecting to this TSAP
1282  *
1283  */
1284 static void irttp_connect_indication(void *instance, void *sap,
1285                 struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1286                 struct sk_buff *skb)
1287 {
1288         struct tsap_cb *self;
1289         struct lsap_cb *lsap;
1290         int parameters;
1291         int ret;
1292         __u8 plen;
1293         __u8 n;
1294
1295         self = (struct tsap_cb *) instance;
1296
1297         IRDA_ASSERT(self != NULL, return;);
1298         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1299         IRDA_ASSERT(skb != NULL, return;);
1300
1301         lsap = (struct lsap_cb *) sap;
1302
1303         self->max_seg_size = max_seg_size - TTP_HEADER;
1304         self->max_header_size = max_header_size+TTP_HEADER;
1305
1306         IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1307
1308         /* Need to update dtsap_sel if its equal to LSAP_ANY */
1309         self->dtsap_sel = lsap->dlsap_sel;
1310
1311         n = skb->data[0] & 0x7f;
1312
1313         self->send_credit = n;
1314         self->tx_max_sdu_size = 0;
1315
1316         parameters = skb->data[0] & 0x80;
1317
1318         IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1319         skb_pull(skb, TTP_HEADER);
1320
1321         if (parameters) {
1322                 plen = skb->data[0];
1323
1324                 ret = irda_param_extract_all(self, skb->data+1,
1325                                              IRDA_MIN(skb->len-1, plen),
1326                                              &param_info);
1327
1328                 /* Any errors in the parameter list? */
1329                 if (ret < 0) {
1330                         IRDA_WARNING("%s: error extracting parameters\n",
1331                                      __func__);
1332                         dev_kfree_skb(skb);
1333
1334                         /* Do not accept this connection attempt */
1335                         return;
1336                 }
1337
1338                 /* Remove parameters */
1339                 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1340         }
1341
1342         if (self->notify.connect_indication) {
1343                 self->notify.connect_indication(self->notify.instance, self,
1344                                                 qos, self->tx_max_sdu_size,
1345                                                 self->max_header_size, skb);
1346         } else
1347                 dev_kfree_skb(skb);
1348 }
1349
1350 /*
1351  * Function irttp_connect_response (handle, userdata)
1352  *
1353  *    Service user is accepting the connection, just pass it down to
1354  *    IrLMP!
1355  *
1356  */
1357 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1358                            struct sk_buff *userdata)
1359 {
1360         struct sk_buff *tx_skb;
1361         __u8 *frame;
1362         int ret;
1363         __u8 n;
1364
1365         IRDA_ASSERT(self != NULL, return -1;);
1366         IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1367
1368         IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1369                    self->stsap_sel);
1370
1371         /* Any userdata supplied? */
1372         if (userdata == NULL) {
1373                 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1374                                    GFP_ATOMIC);
1375                 if (!tx_skb)
1376                         return -ENOMEM;
1377
1378                 /* Reserve space for MUX_CONTROL and LAP header */
1379                 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1380         } else {
1381                 tx_skb = userdata;
1382                 /*
1383                  *  Check that the client has reserved enough space for
1384                  *  headers
1385                  */
1386                 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1387                         { dev_kfree_skb(userdata); return -1; } );
1388         }
1389
1390         self->avail_credit = 0;
1391         self->remote_credit = 0;
1392         self->rx_max_sdu_size = max_sdu_size;
1393         self->rx_sdu_size = 0;
1394         self->rx_sdu_busy = FALSE;
1395
1396         n = self->initial_credit;
1397
1398         /* Frame has only space for max 127 credits (7 bits) */
1399         if (n > 127) {
1400                 self->avail_credit = n - 127;
1401                 n = 127;
1402         }
1403
1404         self->remote_credit = n;
1405         self->connected = TRUE;
1406
1407         /* SAR enabled? */
1408         if (max_sdu_size > 0) {
1409                 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1410                         { dev_kfree_skb(tx_skb); return -1; } );
1411
1412                 /* Insert TTP header with SAR parameters */
1413                 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1414
1415                 frame[0] = TTP_PARAMETERS | n;
1416                 frame[1] = 0x04; /* Length */
1417
1418                 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1,  */
1419 /*                                TTP_SAR_HEADER, &param_info) */
1420
1421                 frame[2] = 0x01; /* MaxSduSize */
1422                 frame[3] = 0x02; /* Value length */
1423
1424                 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1425                               (__be16 *)(frame+4));
1426         } else {
1427                 /* Insert TTP header */
1428                 frame = skb_push(tx_skb, TTP_HEADER);
1429
1430                 frame[0] = n & 0x7f;
1431         }
1432
1433         ret = irlmp_connect_response(self->lsap, tx_skb);
1434
1435         return ret;
1436 }
1437 EXPORT_SYMBOL(irttp_connect_response);
1438
1439 /*
1440  * Function irttp_dup (self, instance)
1441  *
1442  *    Duplicate TSAP, can be used by servers to confirm a connection on a
1443  *    new TSAP so it can keep listening on the old one.
1444  */
1445 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1446 {
1447         struct tsap_cb *new;
1448         unsigned long flags;
1449
1450         IRDA_DEBUG(1, "%s()\n", __func__);
1451
1452         /* Protect our access to the old tsap instance */
1453         spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1454
1455         /* Find the old instance */
1456         if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1457                 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1458                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1459                 return NULL;
1460         }
1461
1462         /* Allocate a new instance */
1463         new = kmalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
1464         if (!new) {
1465                 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1466                 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1467                 return NULL;
1468         }
1469         /* Dup */
1470         memcpy(new, orig, sizeof(struct tsap_cb));
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 }
1495 EXPORT_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  */
1504 int 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 }
1590 EXPORT_SYMBOL(irttp_disconnect_request);
1591
1592 /*
1593  * Function irttp_disconnect_indication (self, reason)
1594  *
1595  *    Disconnect indication, TSAP disconnected by peer?
1596  *
1597  */
1598 static 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 = (struct tsap_cb *) 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  */
1645 static 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  */
1683 static 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
1814 struct irttp_iter_state {
1815         int id;
1816 };
1817
1818 static 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
1838 static 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
1847 static void irttp_seq_stop(struct seq_file *seq, void *v)
1848 {
1849         spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1850 }
1851
1852 static 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
1894 static 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
1901 static 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
1907 const 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 */