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1 /*********************************************************************
2  *
3  * Filename:      irlap_frame.c
4  * Version:       1.0
5  * Description:   Build and transmit IrLAP frames
6  * Status:        Stable
7  * Author:        Dag Brattli <dagb@cs.uit.no>
8  * Created at:    Tue Aug 19 10:27:26 1997
9  * Modified at:   Wed Jan  5 08:59:04 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/if.h>
29 #include <linux/if_ether.h>
30 #include <linux/netdevice.h>
31 #include <linux/irda.h>
32
33 #include <net/pkt_sched.h>
34 #include <net/sock.h>
35
36 #include <asm/byteorder.h>
37
38 #include <net/irda/irda.h>
39 #include <net/irda/irda_device.h>
40 #include <net/irda/irlap.h>
41 #include <net/irda/wrapper.h>
42 #include <net/irda/timer.h>
43 #include <net/irda/irlap_frame.h>
44 #include <net/irda/qos.h>
45
46 static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
47                                int command);
48
49 /*
50  * Function irlap_insert_info (self, skb)
51  *
52  *    Insert minimum turnaround time and speed information into the skb. We
53  *    need to do this since it's per packet relevant information. Safe to
54  *    have this function inlined since it's only called from one place
55  */
56 static inline void irlap_insert_info(struct irlap_cb *self,
57                                      struct sk_buff *skb)
58 {
59         struct irda_skb_cb *cb = (struct irda_skb_cb *) skb->cb;
60
61         /*
62          * Insert MTT (min. turn time) and speed into skb, so that the
63          * device driver knows which settings to use
64          */
65         cb->magic = LAP_MAGIC;
66         cb->mtt = self->mtt_required;
67         cb->next_speed = self->speed;
68
69         /* Reset */
70         self->mtt_required = 0;
71
72         /*
73          * Delay equals negotiated BOFs count, plus the number of BOFs to
74          * force the negotiated minimum turnaround time
75          */
76         cb->xbofs = self->bofs_count;
77         cb->next_xbofs = self->next_bofs;
78         cb->xbofs_delay = self->xbofs_delay;
79
80         /* Reset XBOF's delay (used only for getting min turn time) */
81         self->xbofs_delay = 0;
82         /* Put the correct xbofs value for the next packet */
83         self->bofs_count = self->next_bofs;
84 }
85
86 /*
87  * Function irlap_queue_xmit (self, skb)
88  *
89  *    A little wrapper for dev_queue_xmit, so we can insert some common
90  *    code into it.
91  */
92 void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb)
93 {
94         /* Some common init stuff */
95         skb->dev = self->netdev;
96         skb_reset_mac_header(skb);
97         skb_reset_network_header(skb);
98         skb_reset_transport_header(skb);
99         skb->protocol = htons(ETH_P_IRDA);
100         skb->priority = TC_PRIO_BESTEFFORT;
101
102         irlap_insert_info(self, skb);
103
104         dev_queue_xmit(skb);
105 }
106
107 /*
108  * Function irlap_send_snrm_cmd (void)
109  *
110  *    Transmits a connect SNRM command frame
111  */
112 void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
113 {
114         struct sk_buff *tx_skb;
115         struct snrm_frame *frame;
116         int ret;
117
118         IRDA_ASSERT(self != NULL, return;);
119         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
120
121         /* Allocate frame */
122         tx_skb = alloc_skb(sizeof(struct snrm_frame) +
123                            IRLAP_NEGOCIATION_PARAMS_LEN,
124                            GFP_ATOMIC);
125         if (!tx_skb)
126                 return;
127
128         frame = (struct snrm_frame *) skb_put(tx_skb, 2);
129
130         /* Insert connection address field */
131         if (qos)
132                 frame->caddr = CMD_FRAME | CBROADCAST;
133         else
134                 frame->caddr = CMD_FRAME | self->caddr;
135
136         /* Insert control field */
137         frame->control = SNRM_CMD | PF_BIT;
138
139         /*
140          *  If we are establishing a connection then insert QoS paramerters
141          */
142         if (qos) {
143                 skb_put(tx_skb, 9); /* 25 left */
144                 frame->saddr = cpu_to_le32(self->saddr);
145                 frame->daddr = cpu_to_le32(self->daddr);
146
147                 frame->ncaddr = self->caddr;
148
149                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
150                 if (ret < 0) {
151                         dev_kfree_skb(tx_skb);
152                         return;
153                 }
154         }
155         irlap_queue_xmit(self, tx_skb);
156 }
157
158 /*
159  * Function irlap_recv_snrm_cmd (skb, info)
160  *
161  *    Received SNRM (Set Normal Response Mode) command frame
162  *
163  */
164 static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb,
165                                 struct irlap_info *info)
166 {
167         struct snrm_frame *frame;
168
169         if (pskb_may_pull(skb,sizeof(struct snrm_frame))) {
170                 frame = (struct snrm_frame *) skb->data;
171
172                 /* Copy the new connection address ignoring the C/R bit */
173                 info->caddr = frame->ncaddr & 0xFE;
174
175                 /* Check if the new connection address is valid */
176                 if ((info->caddr == 0x00) || (info->caddr == 0xfe)) {
177                         IRDA_DEBUG(3, "%s(), invalid connection address!\n",
178                                    __FUNCTION__);
179                         return;
180                 }
181
182                 /* Copy peer device address */
183                 info->daddr = le32_to_cpu(frame->saddr);
184                 info->saddr = le32_to_cpu(frame->daddr);
185
186                 /* Only accept if addressed directly to us */
187                 if (info->saddr != self->saddr) {
188                         IRDA_DEBUG(2, "%s(), not addressed to us!\n",
189                                    __FUNCTION__);
190                         return;
191                 }
192                 irlap_do_event(self, RECV_SNRM_CMD, skb, info);
193         } else {
194                 /* Signal that this SNRM frame does not contain and I-field */
195                 irlap_do_event(self, RECV_SNRM_CMD, skb, NULL);
196         }
197 }
198
199 /*
200  * Function irlap_send_ua_response_frame (qos)
201  *
202  *    Send UA (Unnumbered Acknowledgement) frame
203  *
204  */
205 void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos)
206 {
207         struct sk_buff *tx_skb;
208         struct ua_frame *frame;
209         int ret;
210
211         IRDA_DEBUG(2, "%s() <%ld>\n", __FUNCTION__, jiffies);
212
213         IRDA_ASSERT(self != NULL, return;);
214         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
215
216         /* Allocate frame */
217         tx_skb = alloc_skb(sizeof(struct ua_frame) +
218                            IRLAP_NEGOCIATION_PARAMS_LEN,
219                            GFP_ATOMIC);
220         if (!tx_skb)
221                 return;
222
223         frame = (struct ua_frame *) skb_put(tx_skb, 10);
224
225         /* Build UA response */
226         frame->caddr = self->caddr;
227         frame->control = UA_RSP | PF_BIT;
228
229         frame->saddr = cpu_to_le32(self->saddr);
230         frame->daddr = cpu_to_le32(self->daddr);
231
232         /* Should we send QoS negotiation parameters? */
233         if (qos) {
234                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
235                 if (ret < 0) {
236                         dev_kfree_skb(tx_skb);
237                         return;
238                 }
239         }
240
241         irlap_queue_xmit(self, tx_skb);
242 }
243
244
245 /*
246  * Function irlap_send_dm_frame (void)
247  *
248  *    Send disconnected mode (DM) frame
249  *
250  */
251 void irlap_send_dm_frame( struct irlap_cb *self)
252 {
253         struct sk_buff *tx_skb = NULL;
254         struct dm_frame *frame;
255
256         IRDA_ASSERT(self != NULL, return;);
257         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
258
259         tx_skb = alloc_skb(sizeof(struct dm_frame), GFP_ATOMIC);
260         if (!tx_skb)
261                 return;
262
263         frame = (struct dm_frame *)skb_put(tx_skb, 2);
264
265         if (self->state == LAP_NDM)
266                 frame->caddr = CBROADCAST;
267         else
268                 frame->caddr = self->caddr;
269
270         frame->control = DM_RSP | PF_BIT;
271
272         irlap_queue_xmit(self, tx_skb);
273 }
274
275 /*
276  * Function irlap_send_disc_frame (void)
277  *
278  *    Send disconnect (DISC) frame
279  *
280  */
281 void irlap_send_disc_frame(struct irlap_cb *self)
282 {
283         struct sk_buff *tx_skb = NULL;
284         struct disc_frame *frame;
285
286         IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
287
288         IRDA_ASSERT(self != NULL, return;);
289         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
290
291         tx_skb = alloc_skb(sizeof(struct disc_frame), GFP_ATOMIC);
292         if (!tx_skb)
293                 return;
294
295         frame = (struct disc_frame *)skb_put(tx_skb, 2);
296
297         frame->caddr = self->caddr | CMD_FRAME;
298         frame->control = DISC_CMD | PF_BIT;
299
300         irlap_queue_xmit(self, tx_skb);
301 }
302
303 /*
304  * Function irlap_send_discovery_xid_frame (S, s, command)
305  *
306  *    Build and transmit a XID (eXchange station IDentifier) discovery
307  *    frame.
308  */
309 void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
310                                     __u8 command, discovery_t *discovery)
311 {
312         struct sk_buff *tx_skb = NULL;
313         struct xid_frame *frame;
314         __u32 bcast = BROADCAST;
315         __u8 *info;
316
317         IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __FUNCTION__,
318                    s, S, command);
319
320         IRDA_ASSERT(self != NULL, return;);
321         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
322         IRDA_ASSERT(discovery != NULL, return;);
323
324         tx_skb = alloc_skb(sizeof(struct xid_frame) + IRLAP_DISCOVERY_INFO_LEN,
325                            GFP_ATOMIC);
326         if (!tx_skb)
327                 return;
328
329         skb_put(tx_skb, 14);
330         frame = (struct xid_frame *) tx_skb->data;
331
332         if (command) {
333                 frame->caddr = CBROADCAST | CMD_FRAME;
334                 frame->control =  XID_CMD | PF_BIT;
335         } else {
336                 frame->caddr = CBROADCAST;
337                 frame->control =  XID_RSP | PF_BIT;
338         }
339         frame->ident = XID_FORMAT;
340
341         frame->saddr = cpu_to_le32(self->saddr);
342
343         if (command)
344                 frame->daddr = cpu_to_le32(bcast);
345         else
346                 frame->daddr = cpu_to_le32(discovery->data.daddr);
347
348         switch (S) {
349         case 1:
350                 frame->flags = 0x00;
351                 break;
352         case 6:
353                 frame->flags = 0x01;
354                 break;
355         case 8:
356                 frame->flags = 0x02;
357                 break;
358         case 16:
359                 frame->flags = 0x03;
360                 break;
361         default:
362                 frame->flags = 0x02;
363                 break;
364         }
365
366         frame->slotnr = s;
367         frame->version = 0x00;
368
369         /*
370          *  Provide info for final slot only in commands, and for all
371          *  responses. Send the second byte of the hint only if the
372          *  EXTENSION bit is set in the first byte.
373          */
374         if (!command || (frame->slotnr == 0xff)) {
375                 int len;
376
377                 if (discovery->data.hints[0] & HINT_EXTENSION) {
378                         info = skb_put(tx_skb, 2);
379                         info[0] = discovery->data.hints[0];
380                         info[1] = discovery->data.hints[1];
381                 } else {
382                         info = skb_put(tx_skb, 1);
383                         info[0] = discovery->data.hints[0];
384                 }
385                 info = skb_put(tx_skb, 1);
386                 info[0] = discovery->data.charset;
387
388                 len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
389                 info = skb_put(tx_skb, len);
390                 memcpy(info, discovery->data.info, len);
391         }
392         irlap_queue_xmit(self, tx_skb);
393 }
394
395 /*
396  * Function irlap_recv_discovery_xid_rsp (skb, info)
397  *
398  *    Received a XID discovery response
399  *
400  */
401 static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self,
402                                          struct sk_buff *skb,
403                                          struct irlap_info *info)
404 {
405         struct xid_frame *xid;
406         discovery_t *discovery = NULL;
407         __u8 *discovery_info;
408         char *text;
409
410         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
411
412         IRDA_ASSERT(self != NULL, return;);
413         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
414
415         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
416                 IRDA_ERROR("%s: frame too short!\n", __FUNCTION__);
417                 return;
418         }
419
420         xid = (struct xid_frame *) skb->data;
421
422         info->daddr = le32_to_cpu(xid->saddr);
423         info->saddr = le32_to_cpu(xid->daddr);
424
425         /* Make sure frame is addressed to us */
426         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
427                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
428                            __FUNCTION__);
429                 return;
430         }
431
432         if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
433                 IRDA_WARNING("%s: kmalloc failed!\n", __FUNCTION__);
434                 return;
435         }
436
437         discovery->data.daddr = info->daddr;
438         discovery->data.saddr = self->saddr;
439         discovery->timestamp = jiffies;
440
441         IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__,
442                    discovery->data.daddr);
443
444         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
445
446         /* Get info returned from peer */
447         discovery->data.hints[0] = discovery_info[0];
448         if (discovery_info[0] & HINT_EXTENSION) {
449                 IRDA_DEBUG(4, "EXTENSION\n");
450                 discovery->data.hints[1] = discovery_info[1];
451                 discovery->data.charset = discovery_info[2];
452                 text = (char *) &discovery_info[3];
453         } else {
454                 discovery->data.hints[1] = 0;
455                 discovery->data.charset = discovery_info[1];
456                 text = (char *) &discovery_info[2];
457         }
458         /*
459          *  Terminate info string, should be safe since this is where the
460          *  FCS bytes resides.
461          */
462         skb->data[skb->len] = '\0';
463         strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
464         discovery->name_len = strlen(discovery->data.info);
465
466         info->discovery = discovery;
467
468         irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info);
469 }
470
471 /*
472  * Function irlap_recv_discovery_xid_cmd (skb, info)
473  *
474  *    Received a XID discovery command
475  *
476  */
477 static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self,
478                                          struct sk_buff *skb,
479                                          struct irlap_info *info)
480 {
481         struct xid_frame *xid;
482         discovery_t *discovery = NULL;
483         __u8 *discovery_info;
484         char *text;
485
486         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
487                 IRDA_ERROR("%s: frame too short!\n", __FUNCTION__);
488                 return;
489         }
490
491         xid = (struct xid_frame *) skb->data;
492
493         info->daddr = le32_to_cpu(xid->saddr);
494         info->saddr = le32_to_cpu(xid->daddr);
495
496         /* Make sure frame is addressed to us */
497         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
498                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
499                            __FUNCTION__);
500                 return;
501         }
502
503         switch (xid->flags & 0x03) {
504         case 0x00:
505                 info->S = 1;
506                 break;
507         case 0x01:
508                 info->S = 6;
509                 break;
510         case 0x02:
511                 info->S = 8;
512                 break;
513         case 0x03:
514                 info->S = 16;
515                 break;
516         default:
517                 /* Error!! */
518                 return;
519         }
520         info->s = xid->slotnr;
521
522         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
523
524         /*
525          *  Check if last frame
526          */
527         if (info->s == 0xff) {
528                 /* Check if things are sane at this point... */
529                 if((discovery_info == NULL) ||
530                    !pskb_may_pull(skb, 3)) {
531                         IRDA_ERROR("%s: discovery frame too short!\n",
532                                    __FUNCTION__);
533                         return;
534                 }
535
536                 /*
537                  *  We now have some discovery info to deliver!
538                  */
539                 discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC);
540                 if (!discovery) {
541                         IRDA_WARNING("%s: unable to malloc!\n", __FUNCTION__);
542                         return;
543                 }
544
545                 discovery->data.daddr = info->daddr;
546                 discovery->data.saddr = self->saddr;
547                 discovery->timestamp = jiffies;
548
549                 discovery->data.hints[0] = discovery_info[0];
550                 if (discovery_info[0] & HINT_EXTENSION) {
551                         discovery->data.hints[1] = discovery_info[1];
552                         discovery->data.charset = discovery_info[2];
553                         text = (char *) &discovery_info[3];
554                 } else {
555                         discovery->data.hints[1] = 0;
556                         discovery->data.charset = discovery_info[1];
557                         text = (char *) &discovery_info[2];
558                 }
559                 /*
560                  *  Terminate string, should be safe since this is where the
561                  *  FCS bytes resides.
562                  */
563                 skb->data[skb->len] = '\0';
564                 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
565                 discovery->name_len = strlen(discovery->data.info);
566
567                 info->discovery = discovery;
568         } else
569                 info->discovery = NULL;
570
571         irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info);
572 }
573
574 /*
575  * Function irlap_send_rr_frame (self, command)
576  *
577  *    Build and transmit RR (Receive Ready) frame. Notice that it is currently
578  *    only possible to send RR frames with the poll bit set.
579  */
580 void irlap_send_rr_frame(struct irlap_cb *self, int command)
581 {
582         struct sk_buff *tx_skb;
583         struct rr_frame *frame;
584
585         tx_skb = alloc_skb(sizeof(struct rr_frame), GFP_ATOMIC);
586         if (!tx_skb)
587                 return;
588
589         frame = (struct rr_frame *)skb_put(tx_skb, 2);
590
591         frame->caddr = self->caddr;
592         frame->caddr |= (command) ? CMD_FRAME : 0;
593
594         frame->control = RR | PF_BIT | (self->vr << 5);
595
596         irlap_queue_xmit(self, tx_skb);
597 }
598
599 /*
600  * Function irlap_send_rd_frame (self)
601  *
602  *    Request disconnect. Used by a secondary station to request the
603  *    disconnection of the link.
604  */
605 void irlap_send_rd_frame(struct irlap_cb *self)
606 {
607         struct sk_buff *tx_skb;
608         struct rd_frame *frame;
609
610         tx_skb = alloc_skb(sizeof(struct rd_frame), GFP_ATOMIC);
611         if (!tx_skb)
612                 return;
613
614         frame = (struct rd_frame *)skb_put(tx_skb, 2);
615
616         frame->caddr = self->caddr;
617         frame->caddr = RD_RSP | PF_BIT;
618
619         irlap_queue_xmit(self, tx_skb);
620 }
621
622 /*
623  * Function irlap_recv_rr_frame (skb, info)
624  *
625  *    Received RR (Receive Ready) frame from peer station, no harm in
626  *    making it inline since its called only from one single place
627  *    (irlap_driver_rcv).
628  */
629 static inline void irlap_recv_rr_frame(struct irlap_cb *self,
630                                        struct sk_buff *skb,
631                                        struct irlap_info *info, int command)
632 {
633         info->nr = skb->data[1] >> 5;
634
635         /* Check if this is a command or a response frame */
636         if (command)
637                 irlap_do_event(self, RECV_RR_CMD, skb, info);
638         else
639                 irlap_do_event(self, RECV_RR_RSP, skb, info);
640 }
641
642 /*
643  * Function irlap_recv_rnr_frame (self, skb, info)
644  *
645  *    Received RNR (Receive Not Ready) frame from peer station
646  *
647  */
648 static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb,
649                                  struct irlap_info *info, int command)
650 {
651         info->nr = skb->data[1] >> 5;
652
653         IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __FUNCTION__, info->nr, jiffies);
654
655         if (command)
656                 irlap_do_event(self, RECV_RNR_CMD, skb, info);
657         else
658                 irlap_do_event(self, RECV_RNR_RSP, skb, info);
659 }
660
661 static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb,
662                                  struct irlap_info *info, int command)
663 {
664         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
665
666         info->nr = skb->data[1] >> 5;
667
668         /* Check if this is a command or a response frame */
669         if (command)
670                 irlap_do_event(self, RECV_REJ_CMD, skb, info);
671         else
672                 irlap_do_event(self, RECV_REJ_RSP, skb, info);
673 }
674
675 static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb,
676                                   struct irlap_info *info, int command)
677 {
678         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
679
680         info->nr = skb->data[1] >> 5;
681
682         /* Check if this is a command or a response frame */
683         if (command)
684                 irlap_do_event(self, RECV_SREJ_CMD, skb, info);
685         else
686                 irlap_do_event(self, RECV_SREJ_RSP, skb, info);
687 }
688
689 static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb,
690                                   struct irlap_info *info, int command)
691 {
692         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
693
694         /* Check if this is a command or a response frame */
695         if (command)
696                 irlap_do_event(self, RECV_DISC_CMD, skb, info);
697         else
698                 irlap_do_event(self, RECV_RD_RSP, skb, info);
699 }
700
701 /*
702  * Function irlap_recv_ua_frame (skb, frame)
703  *
704  *    Received UA (Unnumbered Acknowledgement) frame
705  *
706  */
707 static inline void irlap_recv_ua_frame(struct irlap_cb *self,
708                                        struct sk_buff *skb,
709                                        struct irlap_info *info)
710 {
711         irlap_do_event(self, RECV_UA_RSP, skb, info);
712 }
713
714 /*
715  * Function irlap_send_data_primary(self, skb)
716  *
717  *    Send I-frames as the primary station but without the poll bit set
718  *
719  */
720 void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb)
721 {
722         struct sk_buff *tx_skb;
723
724         if (skb->data[1] == I_FRAME) {
725
726                 /*
727                  *  Insert frame sequence number (Vs) in control field before
728                  *  inserting into transmit window queue.
729                  */
730                 skb->data[1] = I_FRAME | (self->vs << 1);
731
732                 /*
733                  *  Insert frame in store, in case of retransmissions
734                  *  Increase skb reference count, see irlap_do_event()
735                  */
736                 skb_get(skb);
737                 skb_queue_tail(&self->wx_list, skb);
738
739                 /* Copy buffer */
740                 tx_skb = skb_clone(skb, GFP_ATOMIC);
741                 if (tx_skb == NULL) {
742                         return;
743                 }
744
745                 self->vs = (self->vs + 1) % 8;
746                 self->ack_required = FALSE;
747                 self->window -= 1;
748
749                 irlap_send_i_frame( self, tx_skb, CMD_FRAME);
750         } else {
751                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
752                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
753                 self->window -= 1;
754         }
755 }
756 /*
757  * Function irlap_send_data_primary_poll (self, skb)
758  *
759  *    Send I(nformation) frame as primary with poll bit set
760  */
761 void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb)
762 {
763         struct sk_buff *tx_skb;
764         int transmission_time;
765
766         /* Stop P timer */
767         del_timer(&self->poll_timer);
768
769         /* Is this reliable or unreliable data? */
770         if (skb->data[1] == I_FRAME) {
771
772                 /*
773                  *  Insert frame sequence number (Vs) in control field before
774                  *  inserting into transmit window queue.
775                  */
776                 skb->data[1] = I_FRAME | (self->vs << 1);
777
778                 /*
779                  *  Insert frame in store, in case of retransmissions
780                  *  Increase skb reference count, see irlap_do_event()
781                  */
782                 skb_get(skb);
783                 skb_queue_tail(&self->wx_list, skb);
784
785                 /* Copy buffer */
786                 tx_skb = skb_clone(skb, GFP_ATOMIC);
787                 if (tx_skb == NULL) {
788                         return;
789                 }
790
791                 /*
792                  *  Set poll bit if necessary. We do this to the copied
793                  *  skb, since retransmitted need to set or clear the poll
794                  *  bit depending on when they are sent.
795                  */
796                 tx_skb->data[1] |= PF_BIT;
797
798                 self->vs = (self->vs + 1) % 8;
799                 self->ack_required = FALSE;
800
801                 irlap_next_state(self, LAP_NRM_P);
802                 irlap_send_i_frame(self, tx_skb, CMD_FRAME);
803         } else {
804                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
805
806                 if (self->ack_required) {
807                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
808                         irlap_next_state(self, LAP_NRM_P);
809                         irlap_send_rr_frame(self, CMD_FRAME);
810                         self->ack_required = FALSE;
811                 } else {
812                         skb->data[1] |= PF_BIT;
813                         irlap_next_state(self, LAP_NRM_P);
814                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
815                 }
816         }
817
818         /* How much time we took for transmission of all frames.
819          * We don't know, so let assume we used the full window. Jean II */
820         transmission_time = self->final_timeout;
821
822         /* Reset parameter so that we can fill next window */
823         self->window = self->window_size;
824
825 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
826         /* Remove what we have not used. Just do a prorata of the
827          * bytes left in window to window capacity.
828          * See max_line_capacities[][] in qos.c for details. Jean II */
829         transmission_time -= (self->final_timeout * self->bytes_left
830                               / self->line_capacity);
831         IRDA_DEBUG(4, "%s() adjusting transmission_time : ft=%d, bl=%d, lc=%d -> tt=%d\n", __FUNCTION__, self->final_timeout, self->bytes_left, self->line_capacity, transmission_time);
832
833         /* We are allowed to transmit a maximum number of bytes again. */
834         self->bytes_left = self->line_capacity;
835 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
836
837         /*
838          * The network layer has a intermediate buffer between IrLAP
839          * and the IrDA driver which can contain 8 frames. So, even
840          * though IrLAP is currently sending the *last* frame of the
841          * tx-window, the driver most likely has only just started
842          * sending the *first* frame of the same tx-window.
843          * I.e. we are always at the very begining of or Tx window.
844          * Now, we are supposed to set the final timer from the end
845          * of our tx-window to let the other peer reply. So, we need
846          * to add extra time to compensate for the fact that we
847          * are really at the start of tx-window, otherwise the final timer
848          * might expire before he can answer...
849          * Jean II
850          */
851         irlap_start_final_timer(self, self->final_timeout + transmission_time);
852
853         /*
854          * The clever amongst you might ask why we do this adjustement
855          * only here, and not in all the other cases in irlap_event.c.
856          * In all those other case, we only send a very short management
857          * frame (few bytes), so the adjustement would be lost in the
858          * noise...
859          * The exception of course is irlap_resend_rejected_frame().
860          * Jean II */
861 }
862
863 /*
864  * Function irlap_send_data_secondary_final (self, skb)
865  *
866  *    Send I(nformation) frame as secondary with final bit set
867  *
868  */
869 void irlap_send_data_secondary_final(struct irlap_cb *self,
870                                      struct sk_buff *skb)
871 {
872         struct sk_buff *tx_skb = NULL;
873
874         IRDA_ASSERT(self != NULL, return;);
875         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
876         IRDA_ASSERT(skb != NULL, return;);
877
878         /* Is this reliable or unreliable data? */
879         if (skb->data[1] == I_FRAME) {
880
881                 /*
882                  *  Insert frame sequence number (Vs) in control field before
883                  *  inserting into transmit window queue.
884                  */
885                 skb->data[1] = I_FRAME | (self->vs << 1);
886
887                 /*
888                  *  Insert frame in store, in case of retransmissions
889                  *  Increase skb reference count, see irlap_do_event()
890                  */
891                 skb_get(skb);
892                 skb_queue_tail(&self->wx_list, skb);
893
894                 tx_skb = skb_clone(skb, GFP_ATOMIC);
895                 if (tx_skb == NULL) {
896                         return;
897                 }
898
899                 tx_skb->data[1] |= PF_BIT;
900
901                 self->vs = (self->vs + 1) % 8;
902                 self->ack_required = FALSE;
903
904                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
905         } else {
906                 if (self->ack_required) {
907                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
908                         irlap_send_rr_frame(self, RSP_FRAME);
909                         self->ack_required = FALSE;
910                 } else {
911                         skb->data[1] |= PF_BIT;
912                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
913                 }
914         }
915
916         self->window = self->window_size;
917 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
918         /* We are allowed to transmit a maximum number of bytes again. */
919         self->bytes_left = self->line_capacity;
920 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
921
922         irlap_start_wd_timer(self, self->wd_timeout);
923 }
924
925 /*
926  * Function irlap_send_data_secondary (self, skb)
927  *
928  *    Send I(nformation) frame as secondary without final bit set
929  *
930  */
931 void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
932 {
933         struct sk_buff *tx_skb = NULL;
934
935         /* Is this reliable or unreliable data? */
936         if (skb->data[1] == I_FRAME) {
937
938                 /*
939                  *  Insert frame sequence number (Vs) in control field before
940                  *  inserting into transmit window queue.
941                  */
942                 skb->data[1] = I_FRAME | (self->vs << 1);
943
944                 /*
945                  *  Insert frame in store, in case of retransmissions
946                  *  Increase skb reference count, see irlap_do_event()
947                  */
948                 skb_get(skb);
949                 skb_queue_tail(&self->wx_list, skb);
950
951                 tx_skb = skb_clone(skb, GFP_ATOMIC);
952                 if (tx_skb == NULL) {
953                         return;
954                 }
955
956                 self->vs = (self->vs + 1) % 8;
957                 self->ack_required = FALSE;
958                 self->window -= 1;
959
960                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
961         } else {
962                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
963                 self->window -= 1;
964         }
965 }
966
967 /*
968  * Function irlap_resend_rejected_frames (nr)
969  *
970  *    Resend frames which has not been acknowledged. Should be safe to
971  *    traverse the list without locking it since this function will only be
972  *    called from interrupt context (BH)
973  */
974 void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
975 {
976         struct sk_buff *tx_skb;
977         struct sk_buff *skb;
978         int count;
979
980         IRDA_ASSERT(self != NULL, return;);
981         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
982
983         /* Initialize variables */
984         count = skb_queue_len(&self->wx_list);
985
986         /*  Resend unacknowledged frame(s) */
987         skb = skb_peek(&self->wx_list);
988         while (skb != NULL) {
989                 irlap_wait_min_turn_around(self, &self->qos_tx);
990
991                 /* We copy the skb to be retransmitted since we will have to
992                  * modify it. Cloning will confuse packet sniffers
993                  */
994                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
995                 tx_skb = skb_copy(skb, GFP_ATOMIC);
996                 if (!tx_skb) {
997                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
998                         return;
999                 }
1000
1001                 /* Clear old Nr field + poll bit */
1002                 tx_skb->data[1] &= 0x0f;
1003
1004                 /*
1005                  *  Set poll bit on the last frame retransmitted
1006                  */
1007                 if (count-- == 1)
1008                         tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1009                 else
1010                         tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1011
1012                 irlap_send_i_frame(self, tx_skb, command);
1013
1014                 /*
1015                  *  If our skb is the last buffer in the list, then
1016                  *  we are finished, if not, move to the next sk-buffer
1017                  */
1018                 if (skb == skb_peek_tail(&self->wx_list))
1019                         skb = NULL;
1020                 else
1021                         skb = skb->next;
1022         }
1023 #if 0 /* Not yet */
1024         /*
1025          *  We can now fill the window with additional data frames
1026          */
1027         while (!skb_queue_empty(&self->txq)) {
1028
1029                 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __FUNCTION__);
1030                 if (self->window > 0) {
1031                         skb = skb_dequeue( &self->txq);
1032                         IRDA_ASSERT(skb != NULL, return;);
1033
1034                         /*
1035                          *  If send window > 1 then send frame with pf
1036                          *  bit cleared
1037                          */
1038                         if ((self->window > 1) &&
1039                             !skb_queue_empty(&self->txq)) {
1040                                 irlap_send_data_primary(self, skb);
1041                         } else {
1042                                 irlap_send_data_primary_poll(self, skb);
1043                         }
1044                         kfree_skb(skb);
1045                 }
1046         }
1047 #endif
1048 }
1049
1050 void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1051 {
1052         struct sk_buff *tx_skb;
1053         struct sk_buff *skb;
1054
1055         IRDA_ASSERT(self != NULL, return;);
1056         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1057
1058         /*  Resend unacknowledged frame(s) */
1059         skb = skb_peek(&self->wx_list);
1060         if (skb != NULL) {
1061                 irlap_wait_min_turn_around(self, &self->qos_tx);
1062
1063                 /* We copy the skb to be retransmitted since we will have to
1064                  * modify it. Cloning will confuse packet sniffers
1065                  */
1066                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1067                 tx_skb = skb_copy(skb, GFP_ATOMIC);
1068                 if (!tx_skb) {
1069                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
1070                         return;
1071                 }
1072
1073                 /* Clear old Nr field + poll bit */
1074                 tx_skb->data[1] &= 0x0f;
1075
1076                 /*  Set poll/final bit */
1077                 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1078
1079                 irlap_send_i_frame(self, tx_skb, command);
1080         }
1081 }
1082
1083 /*
1084  * Function irlap_send_ui_frame (self, skb, command)
1085  *
1086  *    Contruct and transmit an Unnumbered Information (UI) frame
1087  *
1088  */
1089 void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1090                          __u8 caddr, int command)
1091 {
1092         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1093
1094         IRDA_ASSERT(self != NULL, return;);
1095         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1096         IRDA_ASSERT(skb != NULL, return;);
1097
1098         /* Insert connection address */
1099         skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1100
1101         irlap_queue_xmit(self, skb);
1102 }
1103
1104 /*
1105  * Function irlap_send_i_frame (skb)
1106  *
1107  *    Contruct and transmit Information (I) frame
1108  */
1109 static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1110                                int command)
1111 {
1112         /* Insert connection address */
1113         skb->data[0] = self->caddr;
1114         skb->data[0] |= (command) ? CMD_FRAME : 0;
1115
1116         /* Insert next to receive (Vr) */
1117         skb->data[1] |= (self->vr << 5);  /* insert nr */
1118
1119         irlap_queue_xmit(self, skb);
1120 }
1121
1122 /*
1123  * Function irlap_recv_i_frame (skb, frame)
1124  *
1125  *    Receive and parse an I (Information) frame, no harm in making it inline
1126  *    since it's called only from one single place (irlap_driver_rcv).
1127  */
1128 static inline void irlap_recv_i_frame(struct irlap_cb *self,
1129                                       struct sk_buff *skb,
1130                                       struct irlap_info *info, int command)
1131 {
1132         info->nr = skb->data[1] >> 5;          /* Next to receive */
1133         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1134         info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1135
1136         /* Check if this is a command or a response frame */
1137         if (command)
1138                 irlap_do_event(self, RECV_I_CMD, skb, info);
1139         else
1140                 irlap_do_event(self, RECV_I_RSP, skb, info);
1141 }
1142
1143 /*
1144  * Function irlap_recv_ui_frame (self, skb, info)
1145  *
1146  *    Receive and parse an Unnumbered Information (UI) frame
1147  *
1148  */
1149 static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1150                                 struct irlap_info *info)
1151 {
1152         IRDA_DEBUG( 4, "%s()\n", __FUNCTION__);
1153
1154         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1155
1156         irlap_do_event(self, RECV_UI_FRAME, skb, info);
1157 }
1158
1159 /*
1160  * Function irlap_recv_frmr_frame (skb, frame)
1161  *
1162  *    Received Frame Reject response.
1163  *
1164  */
1165 static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1166                                   struct irlap_info *info)
1167 {
1168         __u8 *frame;
1169         int w, x, y, z;
1170
1171         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
1172
1173         IRDA_ASSERT(self != NULL, return;);
1174         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1175         IRDA_ASSERT(skb != NULL, return;);
1176         IRDA_ASSERT(info != NULL, return;);
1177
1178         if (!pskb_may_pull(skb, 4)) {
1179                 IRDA_ERROR("%s: frame too short!\n", __FUNCTION__);
1180                 return;
1181         }
1182
1183         frame = skb->data;
1184
1185         info->nr = frame[2] >> 5;          /* Next to receive */
1186         info->pf = frame[2] & PF_BIT;      /* Final bit */
1187         info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1188
1189         w = frame[3] & 0x01;
1190         x = frame[3] & 0x02;
1191         y = frame[3] & 0x04;
1192         z = frame[3] & 0x08;
1193
1194         if (w) {
1195                 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1196                       "implemented.\n");
1197         }
1198         if (x) {
1199                 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1200                       "contained a non permitted I field.\n");
1201         }
1202         if (y) {
1203                 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1204                       "for the existing connection or exceeded the maximum "
1205                       "this station supports if no connection exists.\n");
1206         }
1207         if (z) {
1208                 IRDA_DEBUG(0, "Rejected control field control field contained an "
1209                       "invalid Nr count.\n");
1210         }
1211         irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1212 }
1213
1214 /*
1215  * Function irlap_send_test_frame (self, daddr)
1216  *
1217  *    Send a test frame response
1218  *
1219  */
1220 void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1221                            struct sk_buff *cmd)
1222 {
1223         struct sk_buff *tx_skb;
1224         struct test_frame *frame;
1225         __u8 *info;
1226
1227         tx_skb = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
1228         if (!tx_skb)
1229                 return;
1230
1231         /* Broadcast frames must include saddr and daddr fields */
1232         if (caddr == CBROADCAST) {
1233                 frame = (struct test_frame *)
1234                         skb_put(tx_skb, sizeof(struct test_frame));
1235
1236                 /* Insert the swapped addresses */
1237                 frame->saddr = cpu_to_le32(self->saddr);
1238                 frame->daddr = cpu_to_le32(daddr);
1239         } else
1240                 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1241
1242         frame->caddr = caddr;
1243         frame->control = TEST_RSP | PF_BIT;
1244
1245         /* Copy info */
1246         info = skb_put(tx_skb, cmd->len);
1247         memcpy(info, cmd->data, cmd->len);
1248
1249         /* Return to sender */
1250         irlap_wait_min_turn_around(self, &self->qos_tx);
1251         irlap_queue_xmit(self, tx_skb);
1252 }
1253
1254 /*
1255  * Function irlap_recv_test_frame (self, skb)
1256  *
1257  *    Receive a test frame
1258  *
1259  */
1260 static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1261                                   struct irlap_info *info, int command)
1262 {
1263         struct test_frame *frame;
1264
1265         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
1266
1267         if (!pskb_may_pull(skb, sizeof(*frame))) {
1268                 IRDA_ERROR("%s: frame too short!\n", __FUNCTION__);
1269                 return;
1270         }
1271         frame = (struct test_frame *) skb->data;
1272
1273         /* Broadcast frames must carry saddr and daddr fields */
1274         if (info->caddr == CBROADCAST) {
1275                 if (skb->len < sizeof(struct test_frame)) {
1276                         IRDA_DEBUG(0, "%s() test frame too short!\n",
1277                                    __FUNCTION__);
1278                         return;
1279                 }
1280
1281                 /* Read and swap addresses */
1282                 info->daddr = le32_to_cpu(frame->saddr);
1283                 info->saddr = le32_to_cpu(frame->daddr);
1284
1285                 /* Make sure frame is addressed to us */
1286                 if ((info->saddr != self->saddr) &&
1287                     (info->saddr != BROADCAST)) {
1288                         return;
1289                 }
1290         }
1291
1292         if (command)
1293                 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1294         else
1295                 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1296 }
1297
1298 /*
1299  * Function irlap_driver_rcv (skb, netdev, ptype)
1300  *
1301  *    Called when a frame is received. Dispatches the right receive function
1302  *    for processing of the frame.
1303  *
1304  * Note on skb management :
1305  * After calling the higher layers of the IrDA stack, we always
1306  * kfree() the skb, which drop the reference count (and potentially
1307  * destroy it).
1308  * If a higher layer of the stack want to keep the skb around (to put
1309  * in a queue or pass it to the higher layer), it will need to use
1310  * skb_get() to keep a reference on it. This is usually done at the
1311  * LMP level in irlmp.c.
1312  * Jean II
1313  */
1314 int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
1315                      struct packet_type *ptype, struct net_device *orig_dev)
1316 {
1317         struct irlap_info info;
1318         struct irlap_cb *self;
1319         int command;
1320         __u8 control;
1321
1322         /* FIXME: should we get our own field? */
1323         self = (struct irlap_cb *) dev->atalk_ptr;
1324
1325         /* If the net device is down, then IrLAP is gone! */
1326         if (!self || self->magic != LAP_MAGIC) {
1327                 dev_kfree_skb(skb);
1328                 return -1;
1329         }
1330
1331         /* We are no longer an "old" protocol, so we need to handle
1332          * share and non linear skbs. This should never happen, so
1333          * we don't need to be clever about it. Jean II */
1334         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1335                 IRDA_ERROR("%s: can't clone shared skb!\n", __FUNCTION__);
1336                 dev_kfree_skb(skb);
1337                 return -1;
1338         }
1339
1340         /* Check if frame is large enough for parsing */
1341         if (!pskb_may_pull(skb, 2)) {
1342                 IRDA_ERROR("%s: frame too short!\n", __FUNCTION__);
1343                 dev_kfree_skb(skb);
1344                 return -1;
1345         }
1346
1347         command    = skb->data[0] & CMD_FRAME;
1348         info.caddr = skb->data[0] & CBROADCAST;
1349
1350         info.pf      = skb->data[1] &  PF_BIT;
1351         info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1352
1353         control = info.control;
1354
1355         /*  First we check if this frame has a valid connection address */
1356         if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1357                 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1358                            __FUNCTION__);
1359                 goto out;
1360         }
1361         /*
1362          *  Optimize for the common case and check if the frame is an
1363          *  I(nformation) frame. Only I-frames have bit 0 set to 0
1364          */
1365         if (~control & 0x01) {
1366                 irlap_recv_i_frame(self, skb, &info, command);
1367                 goto out;
1368         }
1369         /*
1370          *  We now check is the frame is an S(upervisory) frame. Only
1371          *  S-frames have bit 0 set to 1 and bit 1 set to 0
1372          */
1373         if (~control & 0x02) {
1374                 /*
1375                  *  Received S(upervisory) frame, check which frame type it is
1376                  *  only the first nibble is of interest
1377                  */
1378                 switch (control & 0x0f) {
1379                 case RR:
1380                         irlap_recv_rr_frame(self, skb, &info, command);
1381                         break;
1382                 case RNR:
1383                         irlap_recv_rnr_frame(self, skb, &info, command);
1384                         break;
1385                 case REJ:
1386                         irlap_recv_rej_frame(self, skb, &info, command);
1387                         break;
1388                 case SREJ:
1389                         irlap_recv_srej_frame(self, skb, &info, command);
1390                         break;
1391                 default:
1392                         IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1393                                 __FUNCTION__, info.control);
1394                         break;
1395                 }
1396                 goto out;
1397         }
1398         /*
1399          *  This must be a C(ontrol) frame
1400          */
1401         switch (control) {
1402         case XID_RSP:
1403                 irlap_recv_discovery_xid_rsp(self, skb, &info);
1404                 break;
1405         case XID_CMD:
1406                 irlap_recv_discovery_xid_cmd(self, skb, &info);
1407                 break;
1408         case SNRM_CMD:
1409                 irlap_recv_snrm_cmd(self, skb, &info);
1410                 break;
1411         case DM_RSP:
1412                 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1413                 break;
1414         case DISC_CMD: /* And RD_RSP since they have the same value */
1415                 irlap_recv_disc_frame(self, skb, &info, command);
1416                 break;
1417         case TEST_CMD:
1418                 irlap_recv_test_frame(self, skb, &info, command);
1419                 break;
1420         case UA_RSP:
1421                 irlap_recv_ua_frame(self, skb, &info);
1422                 break;
1423         case FRMR_RSP:
1424                 irlap_recv_frmr_frame(self, skb, &info);
1425                 break;
1426         case UI_FRAME:
1427                 irlap_recv_ui_frame(self, skb, &info);
1428                 break;
1429         default:
1430                 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1431                                 __FUNCTION__, info.control);
1432                 break;
1433         }
1434 out:
1435         /* Always drop our reference on the skb */
1436         dev_kfree_skb(skb);
1437         return 0;
1438 }