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1/*********************************************************************
2 *
3 * Filename: irttp.c
4 * Version: 1.2
5 * Description: Tiny Transport Protocol (TTP) implementation
6 * Status: Stable
7 * Author: Dag Brattli <dagb@cs.uit.no>
8 * Created at: Sun Aug 31 20:14:31 1997
9 * Modified at: Wed Jan 5 11:31:27 2000
10 * Modified by: Dag Brattli <dagb@cs.uit.no>
11 *
12 * Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
13 * All Rights Reserved.
14 * Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
20 *
21 * Neither Dag Brattli nor University of Tromsø admit liability nor
22 * provide warranty for any of this software. This material is
23 * provided "AS-IS" and at no charge.
24 *
25 ********************************************************************/
26
27#include <linux/skbuff.h>
28#include <linux/init.h>
29#include <linux/fs.h>
30#include <linux/seq_file.h>
31#include <linux/slab.h>
32
33#include <asm/byteorder.h>
34#include <asm/unaligned.h>
35
36#include <net/irda/irda.h>
37#include <net/irda/irlap.h>
38#include <net/irda/irlmp.h>
39#include <net/irda/parameters.h>
40#include <net/irda/irttp.h>
41
42static struct irttp_cb *irttp;
43
44static void __irttp_close_tsap(struct tsap_cb *self);
45
46static int irttp_data_indication(void *instance, void *sap,
47 struct sk_buff *skb);
48static int irttp_udata_indication(void *instance, void *sap,
49 struct sk_buff *skb);
50static void irttp_disconnect_indication(void *instance, void *sap,
51 LM_REASON reason, struct sk_buff *);
52static 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);
55static 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);
58static void irttp_run_tx_queue(struct tsap_cb *self);
59static void irttp_run_rx_queue(struct tsap_cb *self);
60
61static void irttp_flush_queues(struct tsap_cb *self);
62static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
63static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
64static void irttp_todo_expired(unsigned long data);
65static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
66 int get);
67
68static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
69static void irttp_status_indication(void *instance,
70 LINK_STATUS link, LOCK_STATUS lock);
71
72/* Information for parsing parameters in IrTTP */
73static 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};
77static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
78static 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 */
88int __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 */
113void 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 */
140static 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 */
160static 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 */
205static 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 */
234static 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 */
291static 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 */
348static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
349 int get)
350{
351 struct tsap_cb *self;
352
353 self = 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 */
376static 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 */
391struct 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}
466EXPORT_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 */
475static 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 */
506int 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}
543EXPORT_SYMBOL(irttp_close_tsap);
544
545/*
546 * Function irttp_udata_request (self, skb)
547 *
548 * Send unreliable data on this TSAP
549 *
550 */
551int 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
585err:
586 dev_kfree_skb(skb);
587 return ret;
588}
589EXPORT_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 */
598int 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
703err:
704 dev_kfree_skb(skb);
705 return ret;
706}
707EXPORT_SYMBOL(irttp_data_request);
708
709/*
710 * Function irttp_run_tx_queue (self)
711 *
712 * Transmit packets queued for transmission (if possible)
713 *
714 */
715static 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 */
821static 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 */
874static 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 = 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 */
910static 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 = 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 */
992static 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 = 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 */
1024static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1025{
1026 struct tsap_cb *self;
1027
1028 self = 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 */
1069void 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}
1094EXPORT_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 */
1102int 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}
1191EXPORT_SYMBOL(irttp_connect_request);
1192
1193/*
1194 * Function irttp_connect_confirm (handle, qos, skb)
1195 *
1196 * Service user confirms TSAP connection with peer.
1197 *
1198 */
1199static 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 = 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 ¶m_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 */
1284static 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 = 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 = 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 ¶m_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 */
1357int 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, ¶m_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}
1437EXPORT_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 */
1445struct 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}
1495EXPORT_SYMBOL(irttp_dup);
1496
1497/*
1498 * Function irttp_disconnect_request (self)
1499 *
1500 * Close this connection please! If priority is high, the queued data
1501 * segments, if any, will be deallocated first
1502 *
1503 */
1504int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1505 int priority)
1506{
1507 int ret;
1508
1509 IRDA_ASSERT(self != NULL, return -1;);
1510 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1511
1512 /* Already disconnected? */
1513 if (!self->connected) {
1514 IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1515 if (userdata)
1516 dev_kfree_skb(userdata);
1517 return -1;
1518 }
1519
1520 /* Disconnect already pending ?
1521 * We need to use an atomic operation to prevent reentry. This
1522 * function may be called from various context, like user, timer
1523 * for following a disconnect_indication() (i.e. net_bh).
1524 * Jean II */
1525 if(test_and_set_bit(0, &self->disconnect_pend)) {
1526 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1527 __func__);
1528 if (userdata)
1529 dev_kfree_skb(userdata);
1530
1531 /* Try to make some progress */
1532 irttp_run_tx_queue(self);
1533 return -1;
1534 }
1535
1536 /*
1537 * Check if there is still data segments in the transmit queue
1538 */
1539 if (!skb_queue_empty(&self->tx_queue)) {
1540 if (priority == P_HIGH) {
1541 /*
1542 * No need to send the queued data, if we are
1543 * disconnecting right now since the data will
1544 * not have any usable connection to be sent on
1545 */
1546 IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1547 irttp_flush_queues(self);
1548 } else if (priority == P_NORMAL) {
1549 /*
1550 * Must delay disconnect until after all data segments
1551 * have been sent and the tx_queue is empty
1552 */
1553 /* We'll reuse this one later for the disconnect */
1554 self->disconnect_skb = userdata; /* May be NULL */
1555
1556 irttp_run_tx_queue(self);
1557
1558 irttp_start_todo_timer(self, HZ/10);
1559 return -1;
1560 }
1561 }
1562 /* Note : we don't need to check if self->rx_queue is full and the
1563 * state of self->rx_sdu_busy because the disconnect response will
1564 * be sent at the LMP level (so even if the peer has its Tx queue
1565 * full of data). - Jean II */
1566
1567 IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1568 self->connected = FALSE;
1569
1570 if (!userdata) {
1571 struct sk_buff *tx_skb;
1572 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1573 if (!tx_skb)
1574 return -ENOMEM;
1575
1576 /*
1577 * Reserve space for MUX and LAP header
1578 */
1579 skb_reserve(tx_skb, LMP_MAX_HEADER);
1580
1581 userdata = tx_skb;
1582 }
1583 ret = irlmp_disconnect_request(self->lsap, userdata);
1584
1585 /* The disconnect is no longer pending */
1586 clear_bit(0, &self->disconnect_pend); /* FALSE */
1587
1588 return ret;
1589}
1590EXPORT_SYMBOL(irttp_disconnect_request);
1591
1592/*
1593 * Function irttp_disconnect_indication (self, reason)
1594 *
1595 * Disconnect indication, TSAP disconnected by peer?
1596 *
1597 */
1598static void irttp_disconnect_indication(void *instance, void *sap,
1599 LM_REASON reason, struct sk_buff *skb)
1600{
1601 struct tsap_cb *self;
1602
1603 IRDA_DEBUG(4, "%s()\n", __func__);
1604
1605 self = instance;
1606
1607 IRDA_ASSERT(self != NULL, return;);
1608 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1609
1610 /* Prevent higher layer to send more data */
1611 self->connected = FALSE;
1612
1613 /* Check if client has already tried to close the TSAP */
1614 if (self->close_pend) {
1615 /* In this case, the higher layer is probably gone. Don't
1616 * bother it and clean up the remains - Jean II */
1617 if (skb)
1618 dev_kfree_skb(skb);
1619 irttp_close_tsap(self);
1620 return;
1621 }
1622
1623 /* If we are here, we assume that is the higher layer is still
1624 * waiting for the disconnect notification and able to process it,
1625 * even if he tried to disconnect. Otherwise, it would have already
1626 * attempted to close the tsap and self->close_pend would be TRUE.
1627 * Jean II */
1628
1629 /* No need to notify the client if has already tried to disconnect */
1630 if(self->notify.disconnect_indication)
1631 self->notify.disconnect_indication(self->notify.instance, self,
1632 reason, skb);
1633 else
1634 if (skb)
1635 dev_kfree_skb(skb);
1636}
1637
1638/*
1639 * Function irttp_do_data_indication (self, skb)
1640 *
1641 * Try to deliver reassembled skb to layer above, and requeue it if that
1642 * for some reason should fail. We mark rx sdu as busy to apply back
1643 * pressure is necessary.
1644 */
1645static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1646{
1647 int err;
1648
1649 /* Check if client has already closed the TSAP and gone away */
1650 if (self->close_pend) {
1651 dev_kfree_skb(skb);
1652 return;
1653 }
1654
1655 err = self->notify.data_indication(self->notify.instance, self, skb);
1656
1657 /* Usually the layer above will notify that it's input queue is
1658 * starting to get filled by using the flow request, but this may
1659 * be difficult, so it can instead just refuse to eat it and just
1660 * give an error back
1661 */
1662 if (err) {
1663 IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1664
1665 /* Make sure we take a break */
1666 self->rx_sdu_busy = TRUE;
1667
1668 /* Need to push the header in again */
1669 skb_push(skb, TTP_HEADER);
1670 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1671
1672 /* Put skb back on queue */
1673 skb_queue_head(&self->rx_queue, skb);
1674 }
1675}
1676
1677/*
1678 * Function irttp_run_rx_queue (self)
1679 *
1680 * Check if we have any frames to be transmitted, or if we have any
1681 * available credit to give away.
1682 */
1683static void irttp_run_rx_queue(struct tsap_cb *self)
1684{
1685 struct sk_buff *skb;
1686 int more = 0;
1687
1688 IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1689 self->send_credit, self->avail_credit, self->remote_credit);
1690
1691 /* Get exclusive access to the rx queue, otherwise don't touch it */
1692 if (irda_lock(&self->rx_queue_lock) == FALSE)
1693 return;
1694
1695 /*
1696 * Reassemble all frames in receive queue and deliver them
1697 */
1698 while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1699 /* This bit will tell us if it's the last fragment or not */
1700 more = skb->data[0] & 0x80;
1701
1702 /* Remove TTP header */
1703 skb_pull(skb, TTP_HEADER);
1704
1705 /* Add the length of the remaining data */
1706 self->rx_sdu_size += skb->len;
1707
1708 /*
1709 * If SAR is disabled, or user has requested no reassembly
1710 * of received fragments then we just deliver them
1711 * immediately. This can be requested by clients that
1712 * implements byte streams without any message boundaries
1713 */
1714 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1715 irttp_do_data_indication(self, skb);
1716 self->rx_sdu_size = 0;
1717
1718 continue;
1719 }
1720
1721 /* Check if this is a fragment, and not the last fragment */
1722 if (more) {
1723 /*
1724 * Queue the fragment if we still are within the
1725 * limits of the maximum size of the rx_sdu
1726 */
1727 if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1728 IRDA_DEBUG(4, "%s(), queueing frag\n",
1729 __func__);
1730 skb_queue_tail(&self->rx_fragments, skb);
1731 } else {
1732 /* Free the part of the SDU that is too big */
1733 dev_kfree_skb(skb);
1734 }
1735 continue;
1736 }
1737 /*
1738 * This is the last fragment, so time to reassemble!
1739 */
1740 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1741 (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1742 {
1743 /*
1744 * A little optimizing. Only queue the fragment if
1745 * there are other fragments. Since if this is the
1746 * last and only fragment, there is no need to
1747 * reassemble :-)
1748 */
1749 if (!skb_queue_empty(&self->rx_fragments)) {
1750 skb_queue_tail(&self->rx_fragments,
1751 skb);
1752
1753 skb = irttp_reassemble_skb(self);
1754 }
1755
1756 /* Now we can deliver the reassembled skb */
1757 irttp_do_data_indication(self, skb);
1758 } else {
1759 IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1760
1761 /* Free the part of the SDU that is too big */
1762 dev_kfree_skb(skb);
1763
1764 /* Deliver only the valid but truncated part of SDU */
1765 skb = irttp_reassemble_skb(self);
1766
1767 irttp_do_data_indication(self, skb);
1768 }
1769 self->rx_sdu_size = 0;
1770 }
1771
1772 /*
1773 * It's not trivial to keep track of how many credits are available
1774 * by incrementing at each packet, because delivery may fail
1775 * (irttp_do_data_indication() may requeue the frame) and because
1776 * we need to take care of fragmentation.
1777 * We want the other side to send up to initial_credit packets.
1778 * We have some frames in our queues, and we have already allowed it
1779 * to send remote_credit.
1780 * No need to spinlock, write is atomic and self correcting...
1781 * Jean II
1782 */
1783 self->avail_credit = (self->initial_credit -
1784 (self->remote_credit +
1785 skb_queue_len(&self->rx_queue) +
1786 skb_queue_len(&self->rx_fragments)));
1787
1788 /* Do we have too much credits to send to peer ? */
1789 if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1790 (self->avail_credit > 0)) {
1791 /* Send explicit credit frame */
1792 irttp_give_credit(self);
1793 /* Note : do *NOT* check if tx_queue is non-empty, that
1794 * will produce deadlocks. I repeat : send a credit frame
1795 * even if we have something to send in our Tx queue.
1796 * If we have credits, it means that our Tx queue is blocked.
1797 *
1798 * Let's suppose the peer can't keep up with our Tx. He will
1799 * flow control us by not sending us any credits, and we
1800 * will stop Tx and start accumulating credits here.
1801 * Up to the point where the peer will stop its Tx queue,
1802 * for lack of credits.
1803 * Let's assume the peer application is single threaded.
1804 * It will block on Tx and never consume any Rx buffer.
1805 * Deadlock. Guaranteed. - Jean II
1806 */
1807 }
1808
1809 /* Reset lock */
1810 self->rx_queue_lock = 0;
1811}
1812
1813#ifdef CONFIG_PROC_FS
1814struct irttp_iter_state {
1815 int id;
1816};
1817
1818static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1819{
1820 struct irttp_iter_state *iter = seq->private;
1821 struct tsap_cb *self;
1822
1823 /* Protect our access to the tsap list */
1824 spin_lock_irq(&irttp->tsaps->hb_spinlock);
1825 iter->id = 0;
1826
1827 for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1828 self != NULL;
1829 self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1830 if (iter->id == *pos)
1831 break;
1832 ++iter->id;
1833 }
1834
1835 return self;
1836}
1837
1838static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1839{
1840 struct irttp_iter_state *iter = seq->private;
1841
1842 ++*pos;
1843 ++iter->id;
1844 return (void *) hashbin_get_next(irttp->tsaps);
1845}
1846
1847static void irttp_seq_stop(struct seq_file *seq, void *v)
1848{
1849 spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1850}
1851
1852static int irttp_seq_show(struct seq_file *seq, void *v)
1853{
1854 const struct irttp_iter_state *iter = seq->private;
1855 const struct tsap_cb *self = v;
1856
1857 seq_printf(seq, "TSAP %d, ", iter->id);
1858 seq_printf(seq, "stsap_sel: %02x, ",
1859 self->stsap_sel);
1860 seq_printf(seq, "dtsap_sel: %02x\n",
1861 self->dtsap_sel);
1862 seq_printf(seq, " connected: %s, ",
1863 self->connected? "TRUE":"FALSE");
1864 seq_printf(seq, "avail credit: %d, ",
1865 self->avail_credit);
1866 seq_printf(seq, "remote credit: %d, ",
1867 self->remote_credit);
1868 seq_printf(seq, "send credit: %d\n",
1869 self->send_credit);
1870 seq_printf(seq, " tx packets: %lu, ",
1871 self->stats.tx_packets);
1872 seq_printf(seq, "rx packets: %lu, ",
1873 self->stats.rx_packets);
1874 seq_printf(seq, "tx_queue len: %u ",
1875 skb_queue_len(&self->tx_queue));
1876 seq_printf(seq, "rx_queue len: %u\n",
1877 skb_queue_len(&self->rx_queue));
1878 seq_printf(seq, " tx_sdu_busy: %s, ",
1879 self->tx_sdu_busy? "TRUE":"FALSE");
1880 seq_printf(seq, "rx_sdu_busy: %s\n",
1881 self->rx_sdu_busy? "TRUE":"FALSE");
1882 seq_printf(seq, " max_seg_size: %u, ",
1883 self->max_seg_size);
1884 seq_printf(seq, "tx_max_sdu_size: %u, ",
1885 self->tx_max_sdu_size);
1886 seq_printf(seq, "rx_max_sdu_size: %u\n",
1887 self->rx_max_sdu_size);
1888
1889 seq_printf(seq, " Used by (%s)\n\n",
1890 self->notify.name);
1891 return 0;
1892}
1893
1894static const struct seq_operations irttp_seq_ops = {
1895 .start = irttp_seq_start,
1896 .next = irttp_seq_next,
1897 .stop = irttp_seq_stop,
1898 .show = irttp_seq_show,
1899};
1900
1901static int irttp_seq_open(struct inode *inode, struct file *file)
1902{
1903 return seq_open_private(file, &irttp_seq_ops,
1904 sizeof(struct irttp_iter_state));
1905}
1906
1907const struct file_operations irttp_seq_fops = {
1908 .owner = THIS_MODULE,
1909 .open = irttp_seq_open,
1910 .read = seq_read,
1911 .llseek = seq_lseek,
1912 .release = seq_release_private,
1913};
1914
1915#endif /* PROC_FS */