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