7c815de4a3bf95671da2b366b030411794fa2074
[linux-2.6.git] / net / irda / irlap_frame.c
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->h.raw = skb->data;
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 to 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 to 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 to 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_send_i_frame(self, tx_skb, CMD_FRAME);
802         } else {
803                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
804
805                 if (self->ack_required) {
806                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
807                         irlap_send_rr_frame(self, CMD_FRAME);
808                         self->ack_required = FALSE;
809                 } else {
810                         skb->data[1] |= PF_BIT;
811                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
812                 }
813         }
814
815         /* How much time we took for transmission of all frames.
816          * We don't know, so let assume we used the full window. Jean II */
817         transmission_time = self->final_timeout;
818
819         /* Reset parameter so that we can fill next window */
820         self->window = self->window_size;
821
822 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
823         /* Remove what we have not used. Just do a prorata of the
824          * bytes left in window to window capacity.
825          * See max_line_capacities[][] in qos.c for details. Jean II */
826         transmission_time -= (self->final_timeout * self->bytes_left
827                               / self->line_capacity);
828         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);
829
830         /* We are allowed to transmit a maximum number of bytes again. */
831         self->bytes_left = self->line_capacity;
832 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
833
834         /*
835          * The network layer has a intermediate buffer between IrLAP
836          * and the IrDA driver which can contain 8 frames. So, even
837          * though IrLAP is currently sending the *last* frame of the
838          * tx-window, the driver most likely has only just started
839          * sending the *first* frame of the same tx-window.
840          * I.e. we are always at the very begining of or Tx window.
841          * Now, we are supposed to set the final timer from the end
842          * of our tx-window to let the other peer reply. So, we need
843          * to add extra time to compensate for the fact that we
844          * are really at the start of tx-window, otherwise the final timer
845          * might expire before he can answer...
846          * Jean II
847          */
848         irlap_start_final_timer(self, self->final_timeout + transmission_time);
849
850         /*
851          * The clever amongst you might ask why we do this adjustement
852          * only here, and not in all the other cases in irlap_event.c.
853          * In all those other case, we only send a very short management
854          * frame (few bytes), so the adjustement would be lost in the
855          * noise...
856          * The exception of course is irlap_resend_rejected_frame().
857          * Jean II */
858 }
859
860 /*
861  * Function irlap_send_data_secondary_final (self, skb)
862  *
863  *    Send I(nformation) frame as secondary with final bit set
864  *
865  */
866 void irlap_send_data_secondary_final(struct irlap_cb *self,
867                                      struct sk_buff *skb)
868 {
869         struct sk_buff *tx_skb = NULL;
870
871         IRDA_ASSERT(self != NULL, return;);
872         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
873         IRDA_ASSERT(skb != NULL, return;);
874
875         /* Is this reliable or unreliable data? */
876         if (skb->data[1] == I_FRAME) {
877
878                 /*
879                  *  Insert frame sequence number (Vs) in control field before
880                  *  inserting into transmit window queue.
881                  */
882                 skb->data[1] = I_FRAME | (self->vs << 1);
883
884                 /*
885                  *  Insert frame in store, in case of retransmissions
886                  *  Increase skb reference count, see irlap_do_event()
887                  */
888                 skb_get(skb);
889                 skb_queue_tail(&self->wx_list, skb);
890
891                 tx_skb = skb_clone(skb, GFP_ATOMIC);
892                 if (tx_skb == NULL) {
893                         return;
894                 }
895
896                 tx_skb->data[1] |= PF_BIT;
897
898                 self->vs = (self->vs + 1) % 8;
899                 self->ack_required = FALSE;
900
901                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
902         } else {
903                 if (self->ack_required) {
904                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
905                         irlap_send_rr_frame(self, RSP_FRAME);
906                         self->ack_required = FALSE;
907                 } else {
908                         skb->data[1] |= PF_BIT;
909                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
910                 }
911         }
912
913         self->window = self->window_size;
914 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
915         /* We are allowed to transmit a maximum number of bytes again. */
916         self->bytes_left = self->line_capacity;
917 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
918
919         irlap_start_wd_timer(self, self->wd_timeout);
920 }
921
922 /*
923  * Function irlap_send_data_secondary (self, skb)
924  *
925  *    Send I(nformation) frame as secondary without final bit set
926  *
927  */
928 void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
929 {
930         struct sk_buff *tx_skb = NULL;
931
932         /* Is this reliable or unreliable data? */
933         if (skb->data[1] == I_FRAME) {
934
935                 /*
936                  *  Insert frame sequence number (Vs) in control field before
937                  *  inserting into transmit window queue.
938                  */
939                 skb->data[1] = I_FRAME | (self->vs << 1);
940
941                 /*
942                  *  Insert frame in store, in case of retransmissions
943                  *  Increase skb reference count, see irlap_do_event()
944                  */
945                 skb_get(skb);
946                 skb_queue_tail(&self->wx_list, skb);
947
948                 tx_skb = skb_clone(skb, GFP_ATOMIC);
949                 if (tx_skb == NULL) {
950                         return;
951                 }
952
953                 self->vs = (self->vs + 1) % 8;
954                 self->ack_required = FALSE;
955                 self->window -= 1;
956
957                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
958         } else {
959                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
960                 self->window -= 1;
961         }
962 }
963
964 /*
965  * Function irlap_resend_rejected_frames (nr)
966  *
967  *    Resend frames which has not been acknowledged. Should be safe to
968  *    traverse the list without locking it since this function will only be
969  *    called from interrupt context (BH)
970  */
971 void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
972 {
973         struct sk_buff *tx_skb;
974         struct sk_buff *skb;
975         int count;
976
977         IRDA_ASSERT(self != NULL, return;);
978         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
979
980         /* Initialize variables */
981         count = skb_queue_len(&self->wx_list);
982
983         /*  Resend unacknowledged frame(s) */
984         skb = skb_peek(&self->wx_list);
985         while (skb != NULL) {
986                 irlap_wait_min_turn_around(self, &self->qos_tx);
987
988                 /* We copy the skb to be retransmitted since we will have to
989                  * modify it. Cloning will confuse packet sniffers
990                  */
991                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
992                 tx_skb = skb_copy(skb, GFP_ATOMIC);
993                 if (!tx_skb) {
994                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
995                         return;
996                 }
997
998                 /* Clear old Nr field + poll bit */
999                 tx_skb->data[1] &= 0x0f;
1000
1001                 /*
1002                  *  Set poll bit on the last frame retransmitted
1003                  */
1004                 if (count-- == 1)
1005                         tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1006                 else
1007                         tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1008
1009                 irlap_send_i_frame(self, tx_skb, command);
1010
1011                 /*
1012                  *  If our skb is the last buffer in the list, then
1013                  *  we are finished, if not, move to the next sk-buffer
1014                  */
1015                 if (skb == skb_peek_tail(&self->wx_list))
1016                         skb = NULL;
1017                 else
1018                         skb = skb->next;
1019         }
1020 #if 0 /* Not yet */
1021         /*
1022          *  We can now fill the window with additional data frames
1023          */
1024         while (!skb_queue_empty(&self->txq)) {
1025
1026                 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __FUNCTION__);
1027                 if (self->window > 0) {
1028                         skb = skb_dequeue( &self->txq);
1029                         IRDA_ASSERT(skb != NULL, return;);
1030
1031                         /*
1032                          *  If send window > 1 then send frame with pf
1033                          *  bit cleared
1034                          */
1035                         if ((self->window > 1) &&
1036                             !skb_queue_empty(&self->txq)) {
1037                                 irlap_send_data_primary(self, skb);
1038                         } else {
1039                                 irlap_send_data_primary_poll(self, skb);
1040                         }
1041                         kfree_skb(skb);
1042                 }
1043         }
1044 #endif
1045 }
1046
1047 void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1048 {
1049         struct sk_buff *tx_skb;
1050         struct sk_buff *skb;
1051
1052         IRDA_ASSERT(self != NULL, return;);
1053         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1054
1055         /*  Resend unacknowledged frame(s) */
1056         skb = skb_peek(&self->wx_list);
1057         if (skb != NULL) {
1058                 irlap_wait_min_turn_around(self, &self->qos_tx);
1059
1060                 /* We copy the skb to be retransmitted since we will have to
1061                  * modify it. Cloning will confuse packet sniffers
1062                  */
1063                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1064                 tx_skb = skb_copy(skb, GFP_ATOMIC);
1065                 if (!tx_skb) {
1066                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
1067                         return;
1068                 }
1069
1070                 /* Clear old Nr field + poll bit */
1071                 tx_skb->data[1] &= 0x0f;
1072
1073                 /*  Set poll/final bit */
1074                 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1075
1076                 irlap_send_i_frame(self, tx_skb, command);
1077         }
1078 }
1079
1080 /*
1081  * Function irlap_send_ui_frame (self, skb, command)
1082  *
1083  *    Contruct and transmit an Unnumbered Information (UI) frame
1084  *
1085  */
1086 void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1087                          __u8 caddr, int command)
1088 {
1089         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1090
1091         IRDA_ASSERT(self != NULL, return;);
1092         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1093         IRDA_ASSERT(skb != NULL, return;);
1094
1095         /* Insert connection address */
1096         skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1097
1098         irlap_queue_xmit(self, skb);
1099 }
1100
1101 /*
1102  * Function irlap_send_i_frame (skb)
1103  *
1104  *    Contruct and transmit Information (I) frame
1105  */
1106 static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1107                                int command)
1108 {
1109         /* Insert connection address */
1110         skb->data[0] = self->caddr;
1111         skb->data[0] |= (command) ? CMD_FRAME : 0;
1112
1113         /* Insert next to receive (Vr) */
1114         skb->data[1] |= (self->vr << 5);  /* insert nr */
1115
1116         irlap_queue_xmit(self, skb);
1117 }
1118
1119 /*
1120  * Function irlap_recv_i_frame (skb, frame)
1121  *
1122  *    Receive and parse an I (Information) frame, no harm in making it inline
1123  *    since it's called only from one single place (irlap_driver_rcv).
1124  */
1125 static inline void irlap_recv_i_frame(struct irlap_cb *self,
1126                                       struct sk_buff *skb,
1127                                       struct irlap_info *info, int command)
1128 {
1129         info->nr = skb->data[1] >> 5;          /* Next to receive */
1130         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1131         info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1132
1133         /* Check if this is a command or a response frame */
1134         if (command)
1135                 irlap_do_event(self, RECV_I_CMD, skb, info);
1136         else
1137                 irlap_do_event(self, RECV_I_RSP, skb, info);
1138 }
1139
1140 /*
1141  * Function irlap_recv_ui_frame (self, skb, info)
1142  *
1143  *    Receive and parse an Unnumbered Information (UI) frame
1144  *
1145  */
1146 static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1147                                 struct irlap_info *info)
1148 {
1149         IRDA_DEBUG( 4, "%s()\n", __FUNCTION__);
1150
1151         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1152
1153         irlap_do_event(self, RECV_UI_FRAME, skb, info);
1154 }
1155
1156 /*
1157  * Function irlap_recv_frmr_frame (skb, frame)
1158  *
1159  *    Received Frame Reject response.
1160  *
1161  */
1162 static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1163                                   struct irlap_info *info)
1164 {
1165         __u8 *frame;
1166         int w, x, y, z;
1167
1168         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
1169
1170         IRDA_ASSERT(self != NULL, return;);
1171         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1172         IRDA_ASSERT(skb != NULL, return;);
1173         IRDA_ASSERT(info != NULL, return;);
1174
1175         if (!pskb_may_pull(skb, 4)) {
1176                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1177                 return;
1178         }
1179
1180         frame = skb->data;
1181
1182         info->nr = frame[2] >> 5;          /* Next to receive */
1183         info->pf = frame[2] & PF_BIT;      /* Final bit */
1184         info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1185
1186         w = frame[3] & 0x01;
1187         x = frame[3] & 0x02;
1188         y = frame[3] & 0x04;
1189         z = frame[3] & 0x08;
1190
1191         if (w) {
1192                 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1193                       "implemented.\n");
1194         }
1195         if (x) {
1196                 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1197                       "contained a non permitted I field.\n");
1198         }
1199         if (y) {
1200                 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1201                       "for the existing connection or exceeded the maximum "
1202                       "this station supports if no connection exists.\n");
1203         }
1204         if (z) {
1205                 IRDA_DEBUG(0, "Rejected control field control field contained an "
1206                       "invalid Nr count.\n");
1207         }
1208         irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1209 }
1210
1211 /*
1212  * Function irlap_send_test_frame (self, daddr)
1213  *
1214  *    Send a test frame response
1215  *
1216  */
1217 void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1218                            struct sk_buff *cmd)
1219 {
1220         struct sk_buff *tx_skb;
1221         struct test_frame *frame;
1222         __u8 *info;
1223
1224         tx_skb = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
1225         if (!tx_skb)
1226                 return;
1227
1228         /* Broadcast frames must include saddr and daddr fields */
1229         if (caddr == CBROADCAST) {
1230                 frame = (struct test_frame *)
1231                         skb_put(tx_skb, sizeof(struct test_frame));
1232
1233                 /* Insert the swapped addresses */
1234                 frame->saddr = cpu_to_le32(self->saddr);
1235                 frame->daddr = cpu_to_le32(daddr);
1236         } else
1237                 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1238
1239         frame->caddr = caddr;
1240         frame->control = TEST_RSP | PF_BIT;
1241
1242         /* Copy info */
1243         info = skb_put(tx_skb, cmd->len);
1244         memcpy(info, cmd->data, cmd->len);
1245
1246         /* Return to sender */
1247         irlap_wait_min_turn_around(self, &self->qos_tx);
1248         irlap_queue_xmit(self, tx_skb);
1249 }
1250
1251 /*
1252  * Function irlap_recv_test_frame (self, skb)
1253  *
1254  *    Receive a test frame
1255  *
1256  */
1257 static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1258                                   struct irlap_info *info, int command)
1259 {
1260         struct test_frame *frame;
1261
1262         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
1263
1264         if (!pskb_may_pull(skb, sizeof(*frame))) {
1265                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1266                 return;
1267         }
1268         frame = (struct test_frame *) skb->data;
1269
1270         /* Broadcast frames must carry saddr and daddr fields */
1271         if (info->caddr == CBROADCAST) {
1272                 if (skb->len < sizeof(struct test_frame)) {
1273                         IRDA_DEBUG(0, "%s() test frame to short!\n",
1274                                    __FUNCTION__);
1275                         return;
1276                 }
1277
1278                 /* Read and swap addresses */
1279                 info->daddr = le32_to_cpu(frame->saddr);
1280                 info->saddr = le32_to_cpu(frame->daddr);
1281
1282                 /* Make sure frame is addressed to us */
1283                 if ((info->saddr != self->saddr) &&
1284                     (info->saddr != BROADCAST)) {
1285                         return;
1286                 }
1287         }
1288
1289         if (command)
1290                 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1291         else
1292                 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1293 }
1294
1295 /*
1296  * Function irlap_driver_rcv (skb, netdev, ptype)
1297  *
1298  *    Called when a frame is received. Dispatches the right receive function
1299  *    for processing of the frame.
1300  *
1301  * Note on skb management :
1302  * After calling the higher layers of the IrDA stack, we always
1303  * kfree() the skb, which drop the reference count (and potentially
1304  * destroy it).
1305  * If a higher layer of the stack want to keep the skb around (to put
1306  * in a queue or pass it to the higher layer), it will need to use
1307  * skb_get() to keep a reference on it. This is usually done at the
1308  * LMP level in irlmp.c.
1309  * Jean II
1310  */
1311 int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
1312                      struct packet_type *ptype, struct net_device *orig_dev)
1313 {
1314         struct irlap_info info;
1315         struct irlap_cb *self;
1316         int command;
1317         __u8 control;
1318
1319         /* FIXME: should we get our own field? */
1320         self = (struct irlap_cb *) dev->atalk_ptr;
1321
1322         /* If the net device is down, then IrLAP is gone! */
1323         if (!self || self->magic != LAP_MAGIC) {
1324                 dev_kfree_skb(skb);
1325                 return -1;
1326         }
1327
1328         /* We are no longer an "old" protocol, so we need to handle
1329          * share and non linear skbs. This should never happen, so
1330          * we don't need to be clever about it. Jean II */
1331         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1332                 IRDA_ERROR("%s: can't clone shared skb!\n", __FUNCTION__);
1333                 dev_kfree_skb(skb);
1334                 return -1;
1335         }
1336
1337         /* Check if frame is large enough for parsing */
1338         if (!pskb_may_pull(skb, 2)) {
1339                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1340                 dev_kfree_skb(skb);
1341                 return -1;
1342         }
1343
1344         command    = skb->data[0] & CMD_FRAME;
1345         info.caddr = skb->data[0] & CBROADCAST;
1346
1347         info.pf      = skb->data[1] &  PF_BIT;
1348         info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1349
1350         control = info.control;
1351
1352         /*  First we check if this frame has a valid connection address */
1353         if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1354                 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1355                            __FUNCTION__);
1356                 goto out;
1357         }
1358         /*
1359          *  Optimize for the common case and check if the frame is an
1360          *  I(nformation) frame. Only I-frames have bit 0 set to 0
1361          */
1362         if (~control & 0x01) {
1363                 irlap_recv_i_frame(self, skb, &info, command);
1364                 goto out;
1365         }
1366         /*
1367          *  We now check is the frame is an S(upervisory) frame. Only
1368          *  S-frames have bit 0 set to 1 and bit 1 set to 0
1369          */
1370         if (~control & 0x02) {
1371                 /*
1372                  *  Received S(upervisory) frame, check which frame type it is
1373                  *  only the first nibble is of interest
1374                  */
1375                 switch (control & 0x0f) {
1376                 case RR:
1377                         irlap_recv_rr_frame(self, skb, &info, command);
1378                         break;
1379                 case RNR:
1380                         irlap_recv_rnr_frame(self, skb, &info, command);
1381                         break;
1382                 case REJ:
1383                         irlap_recv_rej_frame(self, skb, &info, command);
1384                         break;
1385                 case SREJ:
1386                         irlap_recv_srej_frame(self, skb, &info, command);
1387                         break;
1388                 default:
1389                         IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1390                                 __FUNCTION__, info.control);
1391                         break;
1392                 }
1393                 goto out;
1394         }
1395         /*
1396          *  This must be a C(ontrol) frame
1397          */
1398         switch (control) {
1399         case XID_RSP:
1400                 irlap_recv_discovery_xid_rsp(self, skb, &info);
1401                 break;
1402         case XID_CMD:
1403                 irlap_recv_discovery_xid_cmd(self, skb, &info);
1404                 break;
1405         case SNRM_CMD:
1406                 irlap_recv_snrm_cmd(self, skb, &info);
1407                 break;
1408         case DM_RSP:
1409                 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1410                 break;
1411         case DISC_CMD: /* And RD_RSP since they have the same value */
1412                 irlap_recv_disc_frame(self, skb, &info, command);
1413                 break;
1414         case TEST_CMD:
1415                 irlap_recv_test_frame(self, skb, &info, command);
1416                 break;
1417         case UA_RSP:
1418                 irlap_recv_ua_frame(self, skb, &info);
1419                 break;
1420         case FRMR_RSP:
1421                 irlap_recv_frmr_frame(self, skb, &info);
1422                 break;
1423         case UI_FRAME:
1424                 irlap_recv_ui_frame(self, skb, &info);
1425                 break;
1426         default:
1427                 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1428                                 __FUNCTION__, info.control);
1429                 break;
1430         }
1431 out:
1432         /* Always drop our reference on the skb */
1433         dev_kfree_skb(skb);
1434         return 0;
1435 }