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