[IRDA]: IrCOMM discovery indication simplification
[linux-2.6.git] / net / irda / irlap.c
1 /*********************************************************************
2  *
3  * Filename:      irlap.c
4  * Version:       1.0
5  * Description:   IrLAP implementation for Linux
6  * Status:        Stable
7  * Author:        Dag Brattli <dagb@cs.uit.no>
8  * Created at:    Mon Aug  4 20:40:53 1997
9  * Modified at:   Tue Dec 14 09:26:44 1999
10  * Modified by:   Dag Brattli <dagb@cs.uit.no>
11  *
12  *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
13  *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
14  *
15  *     This program is free software; you can redistribute it and/or
16  *     modify it under the terms of the GNU General Public License as
17  *     published by the Free Software Foundation; either version 2 of
18  *     the License, or (at your option) any later version.
19  *
20  *     This program is distributed in the hope that it will be useful,
21  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
22  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23  *     GNU General Public License for more details.
24  *
25  *     You should have received a copy of the GNU General Public License
26  *     along with this program; if not, write to the Free Software
27  *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28  *     MA 02111-1307 USA
29  *
30  ********************************************************************/
31
32 #include <linux/slab.h>
33 #include <linux/string.h>
34 #include <linux/skbuff.h>
35 #include <linux/delay.h>
36 #include <linux/proc_fs.h>
37 #include <linux/init.h>
38 #include <linux/random.h>
39 #include <linux/module.h>
40 #include <linux/seq_file.h>
41
42 #include <net/irda/irda.h>
43 #include <net/irda/irda_device.h>
44 #include <net/irda/irqueue.h>
45 #include <net/irda/irlmp.h>
46 #include <net/irda/irlmp_frame.h>
47 #include <net/irda/irlap_frame.h>
48 #include <net/irda/irlap.h>
49 #include <net/irda/timer.h>
50 #include <net/irda/qos.h>
51
52 static hashbin_t *irlap = NULL;
53 int sysctl_slot_timeout = SLOT_TIMEOUT * 1000 / HZ;
54
55 /* This is the delay of missed pf period before generating an event
56  * to the application. The spec mandate 3 seconds, but in some cases
57  * it's way too long. - Jean II */
58 int sysctl_warn_noreply_time = 3;
59
60 extern void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb);
61 static void __irlap_close(struct irlap_cb *self);
62 static void irlap_init_qos_capabilities(struct irlap_cb *self,
63                                         struct qos_info *qos_user);
64
65 #ifdef CONFIG_IRDA_DEBUG
66 static char *lap_reasons[] = {
67         "ERROR, NOT USED",
68         "LAP_DISC_INDICATION",
69         "LAP_NO_RESPONSE",
70         "LAP_RESET_INDICATION",
71         "LAP_FOUND_NONE",
72         "LAP_MEDIA_BUSY",
73         "LAP_PRIMARY_CONFLICT",
74         "ERROR, NOT USED",
75 };
76 #endif  /* CONFIG_IRDA_DEBUG */
77
78 int __init irlap_init(void)
79 {
80         /* Check if the compiler did its job properly.
81          * May happen on some ARM configuration, check with Russell King. */
82         IRDA_ASSERT(sizeof(struct xid_frame) == 14, ;);
83         IRDA_ASSERT(sizeof(struct test_frame) == 10, ;);
84         IRDA_ASSERT(sizeof(struct ua_frame) == 10, ;);
85         IRDA_ASSERT(sizeof(struct snrm_frame) == 11, ;);
86
87         /* Allocate master array */
88         irlap = hashbin_new(HB_LOCK);
89         if (irlap == NULL) {
90                 IRDA_ERROR("%s: can't allocate irlap hashbin!\n",
91                            __FUNCTION__);
92                 return -ENOMEM;
93         }
94
95         return 0;
96 }
97
98 void irlap_cleanup(void)
99 {
100         IRDA_ASSERT(irlap != NULL, return;);
101
102         hashbin_delete(irlap, (FREE_FUNC) __irlap_close);
103 }
104
105 /*
106  * Function irlap_open (driver)
107  *
108  *    Initialize IrLAP layer
109  *
110  */
111 struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos,
112                             const char *hw_name)
113 {
114         struct irlap_cb *self;
115
116         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
117
118         /* Initialize the irlap structure. */
119         self = kzalloc(sizeof(struct irlap_cb), GFP_KERNEL);
120         if (self == NULL)
121                 return NULL;
122
123         self->magic = LAP_MAGIC;
124
125         /* Make a binding between the layers */
126         self->netdev = dev;
127         self->qos_dev = qos;
128         /* Copy hardware name */
129         if(hw_name != NULL) {
130                 strlcpy(self->hw_name, hw_name, sizeof(self->hw_name));
131         } else {
132                 self->hw_name[0] = '\0';
133         }
134
135         /* FIXME: should we get our own field? */
136         dev->atalk_ptr = self;
137
138         self->state = LAP_OFFLINE;
139
140         /* Initialize transmit queue */
141         skb_queue_head_init(&self->txq);
142         skb_queue_head_init(&self->txq_ultra);
143         skb_queue_head_init(&self->wx_list);
144
145         /* My unique IrLAP device address! */
146         /* We don't want the broadcast address, neither the NULL address
147          * (most often used to signify "invalid"), and we don't want an
148          * address already in use (otherwise connect won't be able
149          * to select the proper link). - Jean II */
150         do {
151                 get_random_bytes(&self->saddr, sizeof(self->saddr));
152         } while ((self->saddr == 0x0) || (self->saddr == BROADCAST) ||
153                  (hashbin_lock_find(irlap, self->saddr, NULL)) );
154         /* Copy to the driver */
155         memcpy(dev->dev_addr, &self->saddr, 4);
156
157         init_timer(&self->slot_timer);
158         init_timer(&self->query_timer);
159         init_timer(&self->discovery_timer);
160         init_timer(&self->final_timer);
161         init_timer(&self->poll_timer);
162         init_timer(&self->wd_timer);
163         init_timer(&self->backoff_timer);
164         init_timer(&self->media_busy_timer);
165
166         irlap_apply_default_connection_parameters(self);
167
168         self->N3 = 3; /* # connections attemts to try before giving up */
169
170         self->state = LAP_NDM;
171
172         hashbin_insert(irlap, (irda_queue_t *) self, self->saddr, NULL);
173
174         irlmp_register_link(self, self->saddr, &self->notify);
175
176         return self;
177 }
178 EXPORT_SYMBOL(irlap_open);
179
180 /*
181  * Function __irlap_close (self)
182  *
183  *    Remove IrLAP and all allocated memory. Stop any pending timers.
184  *
185  */
186 static void __irlap_close(struct irlap_cb *self)
187 {
188         IRDA_ASSERT(self != NULL, return;);
189         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
190
191         /* Stop timers */
192         del_timer(&self->slot_timer);
193         del_timer(&self->query_timer);
194         del_timer(&self->discovery_timer);
195         del_timer(&self->final_timer);
196         del_timer(&self->poll_timer);
197         del_timer(&self->wd_timer);
198         del_timer(&self->backoff_timer);
199         del_timer(&self->media_busy_timer);
200
201         irlap_flush_all_queues(self);
202
203         self->magic = 0;
204
205         kfree(self);
206 }
207
208 /*
209  * Function irlap_close (self)
210  *
211  *    Remove IrLAP instance
212  *
213  */
214 void irlap_close(struct irlap_cb *self)
215 {
216         struct irlap_cb *lap;
217
218         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
219
220         IRDA_ASSERT(self != NULL, return;);
221         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
222
223         /* We used to send a LAP_DISC_INDICATION here, but this was
224          * racy. This has been move within irlmp_unregister_link()
225          * itself. Jean II */
226
227         /* Kill the LAP and all LSAPs on top of it */
228         irlmp_unregister_link(self->saddr);
229         self->notify.instance = NULL;
230
231         /* Be sure that we manage to remove ourself from the hash */
232         lap = hashbin_remove(irlap, self->saddr, NULL);
233         if (!lap) {
234                 IRDA_DEBUG(1, "%s(), Didn't find myself!\n", __FUNCTION__);
235                 return;
236         }
237         __irlap_close(lap);
238 }
239 EXPORT_SYMBOL(irlap_close);
240
241 /*
242  * Function irlap_connect_indication (self, skb)
243  *
244  *    Another device is attempting to make a connection
245  *
246  */
247 void irlap_connect_indication(struct irlap_cb *self, struct sk_buff *skb)
248 {
249         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
250
251         IRDA_ASSERT(self != NULL, return;);
252         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
253
254         irlap_init_qos_capabilities(self, NULL); /* No user QoS! */
255
256         irlmp_link_connect_indication(self->notify.instance, self->saddr,
257                                       self->daddr, &self->qos_tx, skb);
258 }
259
260 /*
261  * Function irlap_connect_response (self, skb)
262  *
263  *    Service user has accepted incoming connection
264  *
265  */
266 void irlap_connect_response(struct irlap_cb *self, struct sk_buff *userdata)
267 {
268         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
269
270         irlap_do_event(self, CONNECT_RESPONSE, userdata, NULL);
271 }
272
273 /*
274  * Function irlap_connect_request (self, daddr, qos_user, sniff)
275  *
276  *    Request connection with another device, sniffing is not implemented
277  *    yet.
278  *
279  */
280 void irlap_connect_request(struct irlap_cb *self, __u32 daddr,
281                            struct qos_info *qos_user, int sniff)
282 {
283         IRDA_DEBUG(3, "%s(), daddr=0x%08x\n", __FUNCTION__, daddr);
284
285         IRDA_ASSERT(self != NULL, return;);
286         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
287
288         self->daddr = daddr;
289
290         /*
291          *  If the service user specifies QoS values for this connection,
292          *  then use them
293          */
294         irlap_init_qos_capabilities(self, qos_user);
295
296         if ((self->state == LAP_NDM) && !self->media_busy)
297                 irlap_do_event(self, CONNECT_REQUEST, NULL, NULL);
298         else
299                 self->connect_pending = TRUE;
300 }
301
302 /*
303  * Function irlap_connect_confirm (self, skb)
304  *
305  *    Connection request has been accepted
306  *
307  */
308 void irlap_connect_confirm(struct irlap_cb *self, struct sk_buff *skb)
309 {
310         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
311
312         IRDA_ASSERT(self != NULL, return;);
313         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
314
315         irlmp_link_connect_confirm(self->notify.instance, &self->qos_tx, skb);
316 }
317
318 /*
319  * Function irlap_data_indication (self, skb)
320  *
321  *    Received data frames from IR-port, so we just pass them up to
322  *    IrLMP for further processing
323  *
324  */
325 void irlap_data_indication(struct irlap_cb *self, struct sk_buff *skb,
326                            int unreliable)
327 {
328         /* Hide LAP header from IrLMP layer */
329         skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
330
331         irlmp_link_data_indication(self->notify.instance, skb, unreliable);
332 }
333
334
335 /*
336  * Function irlap_data_request (self, skb)
337  *
338  *    Queue data for transmission, must wait until XMIT state
339  *
340  */
341 void irlap_data_request(struct irlap_cb *self, struct sk_buff *skb,
342                         int unreliable)
343 {
344         IRDA_ASSERT(self != NULL, return;);
345         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
346
347         IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
348
349         IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
350                     return;);
351         skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
352
353         /*
354          *  Must set frame format now so that the rest of the code knows
355          *  if its dealing with an I or an UI frame
356          */
357         if (unreliable)
358                 skb->data[1] = UI_FRAME;
359         else
360                 skb->data[1] = I_FRAME;
361
362         /* Don't forget to refcount it - see irlmp_connect_request(). */
363         skb_get(skb);
364
365         /* Add at the end of the queue (keep ordering) - Jean II */
366         skb_queue_tail(&self->txq, skb);
367
368         /*
369          *  Send event if this frame only if we are in the right state
370          *  FIXME: udata should be sent first! (skb_queue_head?)
371          */
372         if ((self->state == LAP_XMIT_P) || (self->state == LAP_XMIT_S)) {
373                 /* If we are not already processing the Tx queue, trigger
374                  * transmission immediately - Jean II */
375                 if((skb_queue_len(&self->txq) <= 1) && (!self->local_busy))
376                         irlap_do_event(self, DATA_REQUEST, skb, NULL);
377                 /* Otherwise, the packets will be sent normally at the
378                  * next pf-poll - Jean II */
379         }
380 }
381
382 /*
383  * Function irlap_unitdata_request (self, skb)
384  *
385  *    Send Ultra data. This is data that must be sent outside any connection
386  *
387  */
388 #ifdef CONFIG_IRDA_ULTRA
389 void irlap_unitdata_request(struct irlap_cb *self, struct sk_buff *skb)
390 {
391         IRDA_ASSERT(self != NULL, return;);
392         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
393
394         IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
395
396         IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
397                return;);
398         skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
399
400         skb->data[0] = CBROADCAST;
401         skb->data[1] = UI_FRAME;
402
403         /* Don't need to refcount, see irlmp_connless_data_request() */
404
405         skb_queue_tail(&self->txq_ultra, skb);
406
407         irlap_do_event(self, SEND_UI_FRAME, NULL, NULL);
408 }
409 #endif /*CONFIG_IRDA_ULTRA */
410
411 /*
412  * Function irlap_udata_indication (self, skb)
413  *
414  *    Receive Ultra data. This is data that is received outside any connection
415  *
416  */
417 #ifdef CONFIG_IRDA_ULTRA
418 void irlap_unitdata_indication(struct irlap_cb *self, struct sk_buff *skb)
419 {
420         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
421
422         IRDA_ASSERT(self != NULL, return;);
423         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
424         IRDA_ASSERT(skb != NULL, return;);
425
426         /* Hide LAP header from IrLMP layer */
427         skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);
428
429         irlmp_link_unitdata_indication(self->notify.instance, skb);
430 }
431 #endif /* CONFIG_IRDA_ULTRA */
432
433 /*
434  * Function irlap_disconnect_request (void)
435  *
436  *    Request to disconnect connection by service user
437  */
438 void irlap_disconnect_request(struct irlap_cb *self)
439 {
440         IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
441
442         IRDA_ASSERT(self != NULL, return;);
443         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
444
445         /* Don't disconnect until all data frames are successfully sent */
446         if (!skb_queue_empty(&self->txq)) {
447                 self->disconnect_pending = TRUE;
448                 return;
449         }
450
451         /* Check if we are in the right state for disconnecting */
452         switch (self->state) {
453         case LAP_XMIT_P:        /* FALLTROUGH */
454         case LAP_XMIT_S:        /* FALLTROUGH */
455         case LAP_CONN:          /* FALLTROUGH */
456         case LAP_RESET_WAIT:    /* FALLTROUGH */
457         case LAP_RESET_CHECK:
458                 irlap_do_event(self, DISCONNECT_REQUEST, NULL, NULL);
459                 break;
460         default:
461                 IRDA_DEBUG(2, "%s(), disconnect pending!\n", __FUNCTION__);
462                 self->disconnect_pending = TRUE;
463                 break;
464         }
465 }
466
467 /*
468  * Function irlap_disconnect_indication (void)
469  *
470  *    Disconnect request from other device
471  *
472  */
473 void irlap_disconnect_indication(struct irlap_cb *self, LAP_REASON reason)
474 {
475         IRDA_DEBUG(1, "%s(), reason=%s\n", __FUNCTION__, lap_reasons[reason]);
476
477         IRDA_ASSERT(self != NULL, return;);
478         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
479
480         /* Flush queues */
481         irlap_flush_all_queues(self);
482
483         switch (reason) {
484         case LAP_RESET_INDICATION:
485                 IRDA_DEBUG(1, "%s(), Sending reset request!\n", __FUNCTION__);
486                 irlap_do_event(self, RESET_REQUEST, NULL, NULL);
487                 break;
488         case LAP_NO_RESPONSE:      /* FALLTROUGH */
489         case LAP_DISC_INDICATION:  /* FALLTROUGH */
490         case LAP_FOUND_NONE:       /* FALLTROUGH */
491         case LAP_MEDIA_BUSY:
492                 irlmp_link_disconnect_indication(self->notify.instance, self,
493                                                  reason, NULL);
494                 break;
495         default:
496                 IRDA_ERROR("%s: Unknown reason %d\n", __FUNCTION__, reason);
497         }
498 }
499
500 /*
501  * Function irlap_discovery_request (gen_addr_bit)
502  *
503  *    Start one single discovery operation.
504  *
505  */
506 void irlap_discovery_request(struct irlap_cb *self, discovery_t *discovery)
507 {
508         struct irlap_info info;
509
510         IRDA_ASSERT(self != NULL, return;);
511         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
512         IRDA_ASSERT(discovery != NULL, return;);
513
514         IRDA_DEBUG(4, "%s(), nslots = %d\n", __FUNCTION__, discovery->nslots);
515
516         IRDA_ASSERT((discovery->nslots == 1) || (discovery->nslots == 6) ||
517                     (discovery->nslots == 8) || (discovery->nslots == 16),
518                     return;);
519
520         /* Discovery is only possible in NDM mode */
521         if (self->state != LAP_NDM) {
522                 IRDA_DEBUG(4, "%s(), discovery only possible in NDM mode\n",
523                            __FUNCTION__);
524                 irlap_discovery_confirm(self, NULL);
525                 /* Note : in theory, if we are not in NDM, we could postpone
526                  * the discovery like we do for connection request.
527                  * In practice, it's not worth it. If the media was busy,
528                  * it's likely next time around it won't be busy. If we are
529                  * in REPLY state, we will get passive discovery info & event.
530                  * Jean II */
531                 return;
532         }
533
534         /* Check if last discovery request finished in time, or if
535          * it was aborted due to the media busy flag. */
536         if (self->discovery_log != NULL) {
537                 hashbin_delete(self->discovery_log, (FREE_FUNC) kfree);
538                 self->discovery_log = NULL;
539         }
540
541         /* All operations will occur at predictable time, no need to lock */
542         self->discovery_log = hashbin_new(HB_NOLOCK);
543
544         if (self->discovery_log == NULL) {
545                 IRDA_WARNING("%s(), Unable to allocate discovery log!\n",
546                              __FUNCTION__);
547                 return;
548         }
549
550         info.S = discovery->nslots; /* Number of slots */
551         info.s = 0; /* Current slot */
552
553         self->discovery_cmd = discovery;
554         info.discovery = discovery;
555
556         /* sysctl_slot_timeout bounds are checked in irsysctl.c - Jean II */
557         self->slot_timeout = sysctl_slot_timeout * HZ / 1000;
558
559         irlap_do_event(self, DISCOVERY_REQUEST, NULL, &info);
560 }
561
562 /*
563  * Function irlap_discovery_confirm (log)
564  *
565  *    A device has been discovered in front of this station, we
566  *    report directly to LMP.
567  */
568 void irlap_discovery_confirm(struct irlap_cb *self, hashbin_t *discovery_log)
569 {
570         IRDA_ASSERT(self != NULL, return;);
571         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
572
573         IRDA_ASSERT(self->notify.instance != NULL, return;);
574
575         /*
576          * Check for successful discovery, since we are then allowed to clear
577          * the media busy condition (IrLAP 6.13.4 - p.94). This should allow
578          * us to make connection attempts much faster and easier (i.e. no
579          * collisions).
580          * Setting media busy to false will also generate an event allowing
581          * to process pending events in NDM state machine.
582          * Note : the spec doesn't define what's a successful discovery is.
583          * If we want Ultra to work, it's successful even if there is
584          * nobody discovered - Jean II
585          */
586         if (discovery_log)
587                 irda_device_set_media_busy(self->netdev, FALSE);
588
589         /* Inform IrLMP */
590         irlmp_link_discovery_confirm(self->notify.instance, discovery_log);
591 }
592
593 /*
594  * Function irlap_discovery_indication (log)
595  *
596  *    Somebody is trying to discover us!
597  *
598  */
599 void irlap_discovery_indication(struct irlap_cb *self, discovery_t *discovery)
600 {
601         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
602
603         IRDA_ASSERT(self != NULL, return;);
604         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
605         IRDA_ASSERT(discovery != NULL, return;);
606
607         IRDA_ASSERT(self->notify.instance != NULL, return;);
608
609         /* A device is very likely to connect immediately after it performs
610          * a successful discovery. This means that in our case, we are much
611          * more likely to receive a connection request over the medium.
612          * So, we backoff to avoid collisions.
613          * IrLAP spec 6.13.4 suggest 100ms...
614          * Note : this little trick actually make a *BIG* difference. If I set
615          * my Linux box with discovery enabled and one Ultra frame sent every
616          * second, my Palm has no trouble connecting to it every time !
617          * Jean II */
618         irda_device_set_media_busy(self->netdev, SMALL);
619
620         irlmp_link_discovery_indication(self->notify.instance, discovery);
621 }
622
623 /*
624  * Function irlap_status_indication (quality_of_link)
625  */
626 void irlap_status_indication(struct irlap_cb *self, int quality_of_link)
627 {
628         switch (quality_of_link) {
629         case STATUS_NO_ACTIVITY:
630                 IRDA_MESSAGE("IrLAP, no activity on link!\n");
631                 break;
632         case STATUS_NOISY:
633                 IRDA_MESSAGE("IrLAP, noisy link!\n");
634                 break;
635         default:
636                 break;
637         }
638         irlmp_status_indication(self->notify.instance,
639                                 quality_of_link, LOCK_NO_CHANGE);
640 }
641
642 /*
643  * Function irlap_reset_indication (void)
644  */
645 void irlap_reset_indication(struct irlap_cb *self)
646 {
647         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
648
649         IRDA_ASSERT(self != NULL, return;);
650         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
651
652         if (self->state == LAP_RESET_WAIT)
653                 irlap_do_event(self, RESET_REQUEST, NULL, NULL);
654         else
655                 irlap_do_event(self, RESET_RESPONSE, NULL, NULL);
656 }
657
658 /*
659  * Function irlap_reset_confirm (void)
660  */
661 void irlap_reset_confirm(void)
662 {
663         IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
664 }
665
666 /*
667  * Function irlap_generate_rand_time_slot (S, s)
668  *
669  *    Generate a random time slot between s and S-1 where
670  *    S = Number of slots (0 -> S-1)
671  *    s = Current slot
672  */
673 int irlap_generate_rand_time_slot(int S, int s)
674 {
675         static int rand;
676         int slot;
677
678         IRDA_ASSERT((S - s) > 0, return 0;);
679
680         rand += jiffies;
681         rand ^= (rand << 12);
682         rand ^= (rand >> 20);
683
684         slot = s + rand % (S-s);
685
686         IRDA_ASSERT((slot >= s) || (slot < S), return 0;);
687
688         return slot;
689 }
690
691 /*
692  * Function irlap_update_nr_received (nr)
693  *
694  *    Remove all acknowledged frames in current window queue. This code is
695  *    not intuitive and you should not try to change it. If you think it
696  *    contains bugs, please mail a patch to the author instead.
697  */
698 void irlap_update_nr_received(struct irlap_cb *self, int nr)
699 {
700         struct sk_buff *skb = NULL;
701         int count = 0;
702
703         /*
704          * Remove all the ack-ed frames from the window queue.
705          */
706
707         /*
708          *  Optimize for the common case. It is most likely that the receiver
709          *  will acknowledge all the frames we have sent! So in that case we
710          *  delete all frames stored in window.
711          */
712         if (nr == self->vs) {
713                 while ((skb = skb_dequeue(&self->wx_list)) != NULL) {
714                         dev_kfree_skb(skb);
715                 }
716                 /* The last acked frame is the next to send minus one */
717                 self->va = nr - 1;
718         } else {
719                 /* Remove all acknowledged frames in current window */
720                 while ((skb_peek(&self->wx_list) != NULL) &&
721                        (((self->va+1) % 8) != nr))
722                 {
723                         skb = skb_dequeue(&self->wx_list);
724                         dev_kfree_skb(skb);
725
726                         self->va = (self->va + 1) % 8;
727                         count++;
728                 }
729         }
730
731         /* Advance window */
732         self->window = self->window_size - skb_queue_len(&self->wx_list);
733 }
734
735 /*
736  * Function irlap_validate_ns_received (ns)
737  *
738  *    Validate the next to send (ns) field from received frame.
739  */
740 int irlap_validate_ns_received(struct irlap_cb *self, int ns)
741 {
742         /*  ns as expected?  */
743         if (ns == self->vr)
744                 return NS_EXPECTED;
745         /*
746          *  Stations are allowed to treat invalid NS as unexpected NS
747          *  IrLAP, Recv ... with-invalid-Ns. p. 84
748          */
749         return NS_UNEXPECTED;
750
751         /* return NR_INVALID; */
752 }
753 /*
754  * Function irlap_validate_nr_received (nr)
755  *
756  *    Validate the next to receive (nr) field from received frame.
757  *
758  */
759 int irlap_validate_nr_received(struct irlap_cb *self, int nr)
760 {
761         /*  nr as expected?  */
762         if (nr == self->vs) {
763                 IRDA_DEBUG(4, "%s(), expected!\n", __FUNCTION__);
764                 return NR_EXPECTED;
765         }
766
767         /*
768          *  unexpected nr? (but within current window), first we check if the
769          *  ns numbers of the frames in the current window wrap.
770          */
771         if (self->va < self->vs) {
772                 if ((nr >= self->va) && (nr <= self->vs))
773                         return NR_UNEXPECTED;
774         } else {
775                 if ((nr >= self->va) || (nr <= self->vs))
776                         return NR_UNEXPECTED;
777         }
778
779         /* Invalid nr!  */
780         return NR_INVALID;
781 }
782
783 /*
784  * Function irlap_initiate_connection_state ()
785  *
786  *    Initialize the connection state parameters
787  *
788  */
789 void irlap_initiate_connection_state(struct irlap_cb *self)
790 {
791         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
792
793         IRDA_ASSERT(self != NULL, return;);
794         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
795
796         /* Next to send and next to receive */
797         self->vs = self->vr = 0;
798
799         /* Last frame which got acked (0 - 1) % 8 */
800         self->va = 7;
801
802         self->window = 1;
803
804         self->remote_busy = FALSE;
805         self->retry_count = 0;
806 }
807
808 /*
809  * Function irlap_wait_min_turn_around (self, qos)
810  *
811  *    Wait negotiated minimum turn around time, this function actually sets
812  *    the number of BOS's that must be sent before the next transmitted
813  *    frame in order to delay for the specified amount of time. This is
814  *    done to avoid using timers, and the forbidden udelay!
815  */
816 void irlap_wait_min_turn_around(struct irlap_cb *self, struct qos_info *qos)
817 {
818         __u32 min_turn_time;
819         __u32 speed;
820
821         /* Get QoS values.  */
822         speed = qos->baud_rate.value;
823         min_turn_time = qos->min_turn_time.value;
824
825         /* No need to calculate XBOFs for speeds over 115200 bps */
826         if (speed > 115200) {
827                 self->mtt_required = min_turn_time;
828                 return;
829         }
830
831         /*
832          *  Send additional BOF's for the next frame for the requested
833          *  min turn time, so now we must calculate how many chars (XBOF's) we
834          *  must send for the requested time period (min turn time)
835          */
836         self->xbofs_delay = irlap_min_turn_time_in_bytes(speed, min_turn_time);
837 }
838
839 /*
840  * Function irlap_flush_all_queues (void)
841  *
842  *    Flush all queues
843  *
844  */
845 void irlap_flush_all_queues(struct irlap_cb *self)
846 {
847         struct sk_buff* skb;
848
849         IRDA_ASSERT(self != NULL, return;);
850         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
851
852         /* Free transmission queue */
853         while ((skb = skb_dequeue(&self->txq)) != NULL)
854                 dev_kfree_skb(skb);
855
856         while ((skb = skb_dequeue(&self->txq_ultra)) != NULL)
857                 dev_kfree_skb(skb);
858
859         /* Free sliding window buffered packets */
860         while ((skb = skb_dequeue(&self->wx_list)) != NULL)
861                 dev_kfree_skb(skb);
862 }
863
864 /*
865  * Function irlap_setspeed (self, speed)
866  *
867  *    Change the speed of the IrDA port
868  *
869  */
870 static void irlap_change_speed(struct irlap_cb *self, __u32 speed, int now)
871 {
872         struct sk_buff *skb;
873
874         IRDA_DEBUG(0, "%s(), setting speed to %d\n", __FUNCTION__, speed);
875
876         IRDA_ASSERT(self != NULL, return;);
877         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
878
879         self->speed = speed;
880
881         /* Change speed now, or just piggyback speed on frames */
882         if (now) {
883                 /* Send down empty frame to trigger speed change */
884                 skb = alloc_skb(0, GFP_ATOMIC);
885                 if (skb)
886                         irlap_queue_xmit(self, skb);
887         }
888 }
889
890 /*
891  * Function irlap_init_qos_capabilities (self, qos)
892  *
893  *    Initialize QoS for this IrLAP session, What we do is to compute the
894  *    intersection of the QoS capabilities for the user, driver and for
895  *    IrLAP itself. Normally, IrLAP will not specify any values, but it can
896  *    be used to restrict certain values.
897  */
898 static void irlap_init_qos_capabilities(struct irlap_cb *self,
899                                         struct qos_info *qos_user)
900 {
901         IRDA_ASSERT(self != NULL, return;);
902         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
903         IRDA_ASSERT(self->netdev != NULL, return;);
904
905         /* Start out with the maximum QoS support possible */
906         irda_init_max_qos_capabilies(&self->qos_rx);
907
908         /* Apply drivers QoS capabilities */
909         irda_qos_compute_intersection(&self->qos_rx, self->qos_dev);
910
911         /*
912          *  Check for user supplied QoS parameters. The service user is only
913          *  allowed to supply these values. We check each parameter since the
914          *  user may not have set all of them.
915          */
916         if (qos_user) {
917                 IRDA_DEBUG(1, "%s(), Found user specified QoS!\n", __FUNCTION__);
918
919                 if (qos_user->baud_rate.bits)
920                         self->qos_rx.baud_rate.bits &= qos_user->baud_rate.bits;
921
922                 if (qos_user->max_turn_time.bits)
923                         self->qos_rx.max_turn_time.bits &= qos_user->max_turn_time.bits;
924                 if (qos_user->data_size.bits)
925                         self->qos_rx.data_size.bits &= qos_user->data_size.bits;
926
927                 if (qos_user->link_disc_time.bits)
928                         self->qos_rx.link_disc_time.bits &= qos_user->link_disc_time.bits;
929         }
930
931         /* Use 500ms in IrLAP for now */
932         self->qos_rx.max_turn_time.bits &= 0x01;
933
934         /* Set data size */
935         /*self->qos_rx.data_size.bits &= 0x03;*/
936
937         irda_qos_bits_to_value(&self->qos_rx);
938 }
939
940 /*
941  * Function irlap_apply_default_connection_parameters (void, now)
942  *
943  *    Use the default connection and transmission parameters
944  */
945 void irlap_apply_default_connection_parameters(struct irlap_cb *self)
946 {
947         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
948
949         IRDA_ASSERT(self != NULL, return;);
950         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
951
952         /* xbofs : Default value in NDM */
953         self->next_bofs   = 12;
954         self->bofs_count  = 12;
955
956         /* NDM Speed is 9600 */
957         irlap_change_speed(self, 9600, TRUE);
958
959         /* Set mbusy when going to NDM state */
960         irda_device_set_media_busy(self->netdev, TRUE);
961
962         /*
963          * Generate random connection address for this session, which must
964          * be 7 bits wide and different from 0x00 and 0xfe
965          */
966         while ((self->caddr == 0x00) || (self->caddr == 0xfe)) {
967                 get_random_bytes(&self->caddr, sizeof(self->caddr));
968                 self->caddr &= 0xfe;
969         }
970
971         /* Use default values until connection has been negitiated */
972         self->slot_timeout = sysctl_slot_timeout;
973         self->final_timeout = FINAL_TIMEOUT;
974         self->poll_timeout = POLL_TIMEOUT;
975         self->wd_timeout = WD_TIMEOUT;
976
977         /* Set some default values */
978         self->qos_tx.baud_rate.value = 9600;
979         self->qos_rx.baud_rate.value = 9600;
980         self->qos_tx.max_turn_time.value = 0;
981         self->qos_rx.max_turn_time.value = 0;
982         self->qos_tx.min_turn_time.value = 0;
983         self->qos_rx.min_turn_time.value = 0;
984         self->qos_tx.data_size.value = 64;
985         self->qos_rx.data_size.value = 64;
986         self->qos_tx.window_size.value = 1;
987         self->qos_rx.window_size.value = 1;
988         self->qos_tx.additional_bofs.value = 12;
989         self->qos_rx.additional_bofs.value = 12;
990         self->qos_tx.link_disc_time.value = 0;
991         self->qos_rx.link_disc_time.value = 0;
992
993         irlap_flush_all_queues(self);
994
995         self->disconnect_pending = FALSE;
996         self->connect_pending = FALSE;
997 }
998
999 /*
1000  * Function irlap_apply_connection_parameters (qos, now)
1001  *
1002  *    Initialize IrLAP with the negotiated QoS values
1003  *
1004  * If 'now' is false, the speed and xbofs will be changed after the next
1005  * frame is sent.
1006  * If 'now' is true, the speed and xbofs is changed immediately
1007  */
1008 void irlap_apply_connection_parameters(struct irlap_cb *self, int now)
1009 {
1010         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1011
1012         IRDA_ASSERT(self != NULL, return;);
1013         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1014
1015         /* Set the negotiated xbofs value */
1016         self->next_bofs   = self->qos_tx.additional_bofs.value;
1017         if (now)
1018                 self->bofs_count = self->next_bofs;
1019
1020         /* Set the negotiated link speed (may need the new xbofs value) */
1021         irlap_change_speed(self, self->qos_tx.baud_rate.value, now);
1022
1023         self->window_size = self->qos_tx.window_size.value;
1024         self->window      = self->qos_tx.window_size.value;
1025
1026 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1027         /*
1028          *  Calculate how many bytes it is possible to transmit before the
1029          *  link must be turned around
1030          */
1031         self->line_capacity =
1032                 irlap_max_line_capacity(self->qos_tx.baud_rate.value,
1033                                         self->qos_tx.max_turn_time.value);
1034         self->bytes_left = self->line_capacity;
1035 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1036
1037
1038         /*
1039          *  Initialize timeout values, some of the rules are listed on
1040          *  page 92 in IrLAP.
1041          */
1042         IRDA_ASSERT(self->qos_tx.max_turn_time.value != 0, return;);
1043         IRDA_ASSERT(self->qos_rx.max_turn_time.value != 0, return;);
1044         /* The poll timeout applies only to the primary station.
1045          * It defines the maximum time the primary stay in XMIT mode
1046          * before timeout and turning the link around (sending a RR).
1047          * Or, this is how much we can keep the pf bit in primary mode.
1048          * Therefore, it must be lower or equal than our *OWN* max turn around.
1049          * Jean II */
1050         self->poll_timeout = self->qos_tx.max_turn_time.value * HZ / 1000;
1051         /* The Final timeout applies only to the primary station.
1052          * It defines the maximum time the primary wait (mostly in RECV mode)
1053          * for an answer from the secondary station before polling it again.
1054          * Therefore, it must be greater or equal than our *PARTNER*
1055          * max turn around time - Jean II */
1056         self->final_timeout = self->qos_rx.max_turn_time.value * HZ / 1000;
1057         /* The Watchdog Bit timeout applies only to the secondary station.
1058          * It defines the maximum time the secondary wait (mostly in RECV mode)
1059          * for poll from the primary station before getting annoyed.
1060          * Therefore, it must be greater or equal than our *PARTNER*
1061          * max turn around time - Jean II */
1062         self->wd_timeout = self->final_timeout * 2;
1063
1064         /*
1065          * N1 and N2 are maximum retry count for *both* the final timer
1066          * and the wd timer (with a factor 2) as defined above.
1067          * After N1 retry of a timer, we give a warning to the user.
1068          * After N2 retry, we consider the link dead and disconnect it.
1069          * Jean II
1070          */
1071
1072         /*
1073          *  Set N1 to 0 if Link Disconnect/Threshold Time = 3 and set it to
1074          *  3 seconds otherwise. See page 71 in IrLAP for more details.
1075          *  Actually, it's not always 3 seconds, as we allow to set
1076          *  it via sysctl... Max maxtt is 500ms, and N1 need to be multiple
1077          *  of 2, so 1 second is minimum we can allow. - Jean II
1078          */
1079         if (self->qos_tx.link_disc_time.value == sysctl_warn_noreply_time)
1080                 /*
1081                  * If we set N1 to 0, it will trigger immediately, which is
1082                  * not what we want. What we really want is to disable it,
1083                  * Jean II
1084                  */
1085                 self->N1 = -2; /* Disable - Need to be multiple of 2*/
1086         else
1087                 self->N1 = sysctl_warn_noreply_time * 1000 /
1088                   self->qos_rx.max_turn_time.value;
1089
1090         IRDA_DEBUG(4, "Setting N1 = %d\n", self->N1);
1091
1092         /* Set N2 to match our own disconnect time */
1093         self->N2 = self->qos_tx.link_disc_time.value * 1000 /
1094                 self->qos_rx.max_turn_time.value;
1095         IRDA_DEBUG(4, "Setting N2 = %d\n", self->N2);
1096 }
1097
1098 #ifdef CONFIG_PROC_FS
1099 struct irlap_iter_state {
1100         int id;
1101 };
1102
1103 static void *irlap_seq_start(struct seq_file *seq, loff_t *pos)
1104 {
1105         struct irlap_iter_state *iter = seq->private;
1106         struct irlap_cb *self;
1107
1108         /* Protect our access to the tsap list */
1109         spin_lock_irq(&irlap->hb_spinlock);
1110         iter->id = 0;
1111
1112         for (self = (struct irlap_cb *) hashbin_get_first(irlap);
1113              self; self = (struct irlap_cb *) hashbin_get_next(irlap)) {
1114                 if (iter->id == *pos)
1115                         break;
1116                 ++iter->id;
1117         }
1118
1119         return self;
1120 }
1121
1122 static void *irlap_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1123 {
1124         struct irlap_iter_state *iter = seq->private;
1125
1126         ++*pos;
1127         ++iter->id;
1128         return (void *) hashbin_get_next(irlap);
1129 }
1130
1131 static void irlap_seq_stop(struct seq_file *seq, void *v)
1132 {
1133         spin_unlock_irq(&irlap->hb_spinlock);
1134 }
1135
1136 static int irlap_seq_show(struct seq_file *seq, void *v)
1137 {
1138         const struct irlap_iter_state *iter = seq->private;
1139         const struct irlap_cb *self = v;
1140
1141         IRDA_ASSERT(self->magic == LAP_MAGIC, return -EINVAL;);
1142
1143         seq_printf(seq, "irlap%d ", iter->id);
1144         seq_printf(seq, "state: %s\n",
1145                    irlap_state[self->state]);
1146
1147         seq_printf(seq, "  device name: %s, ",
1148                    (self->netdev) ? self->netdev->name : "bug");
1149         seq_printf(seq, "hardware name: %s\n", self->hw_name);
1150
1151         seq_printf(seq, "  caddr: %#02x, ", self->caddr);
1152         seq_printf(seq, "saddr: %#08x, ", self->saddr);
1153         seq_printf(seq, "daddr: %#08x\n", self->daddr);
1154
1155         seq_printf(seq, "  win size: %d, ",
1156                    self->window_size);
1157         seq_printf(seq, "win: %d, ", self->window);
1158 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1159         seq_printf(seq, "line capacity: %d, ",
1160                    self->line_capacity);
1161         seq_printf(seq, "bytes left: %d\n", self->bytes_left);
1162 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1163         seq_printf(seq, "  tx queue len: %d ",
1164                    skb_queue_len(&self->txq));
1165         seq_printf(seq, "win queue len: %d ",
1166                    skb_queue_len(&self->wx_list));
1167         seq_printf(seq, "rbusy: %s", self->remote_busy ?
1168                    "TRUE" : "FALSE");
1169         seq_printf(seq, " mbusy: %s\n", self->media_busy ?
1170                    "TRUE" : "FALSE");
1171
1172         seq_printf(seq, "  retrans: %d ", self->retry_count);
1173         seq_printf(seq, "vs: %d ", self->vs);
1174         seq_printf(seq, "vr: %d ", self->vr);
1175         seq_printf(seq, "va: %d\n", self->va);
1176
1177         seq_printf(seq, "  qos\tbps\tmaxtt\tdsize\twinsize\taddbofs\tmintt\tldisc\tcomp\n");
1178
1179         seq_printf(seq, "  tx\t%d\t",
1180                    self->qos_tx.baud_rate.value);
1181         seq_printf(seq, "%d\t",
1182                    self->qos_tx.max_turn_time.value);
1183         seq_printf(seq, "%d\t",
1184                    self->qos_tx.data_size.value);
1185         seq_printf(seq, "%d\t",
1186                    self->qos_tx.window_size.value);
1187         seq_printf(seq, "%d\t",
1188                    self->qos_tx.additional_bofs.value);
1189         seq_printf(seq, "%d\t",
1190                    self->qos_tx.min_turn_time.value);
1191         seq_printf(seq, "%d\t",
1192                    self->qos_tx.link_disc_time.value);
1193         seq_printf(seq, "\n");
1194
1195         seq_printf(seq, "  rx\t%d\t",
1196                    self->qos_rx.baud_rate.value);
1197         seq_printf(seq, "%d\t",
1198                    self->qos_rx.max_turn_time.value);
1199         seq_printf(seq, "%d\t",
1200                    self->qos_rx.data_size.value);
1201         seq_printf(seq, "%d\t",
1202                    self->qos_rx.window_size.value);
1203         seq_printf(seq, "%d\t",
1204                    self->qos_rx.additional_bofs.value);
1205         seq_printf(seq, "%d\t",
1206                    self->qos_rx.min_turn_time.value);
1207         seq_printf(seq, "%d\n",
1208                    self->qos_rx.link_disc_time.value);
1209
1210         return 0;
1211 }
1212
1213 static const struct seq_operations irlap_seq_ops = {
1214         .start  = irlap_seq_start,
1215         .next   = irlap_seq_next,
1216         .stop   = irlap_seq_stop,
1217         .show   = irlap_seq_show,
1218 };
1219
1220 static int irlap_seq_open(struct inode *inode, struct file *file)
1221 {
1222         if (irlap == NULL)
1223                 return -EINVAL;
1224
1225         return seq_open_private(file, &irlap_seq_ops,
1226                         sizeof(struct irlap_iter_state));
1227 }
1228
1229 const struct file_operations irlap_seq_fops = {
1230         .owner          = THIS_MODULE,
1231         .open           = irlap_seq_open,
1232         .read           = seq_read,
1233         .llseek         = seq_lseek,
1234         .release        = seq_release_private,
1235 };
1236
1237 #endif /* CONFIG_PROC_FS */