xref: /freebsd/usr.sbin/ppp/fsm.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
1 /*
2  *		PPP Finite State Machine for LCP/IPCP
3  *
4  *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
5  *
6  *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
7  *
8  * Redistribution and use in source and binary forms are permitted
9  * provided that the above copyright notice and this paragraph are
10  * duplicated in all such forms and that any documentation,
11  * advertising materials, and other materials related to such
12  * distribution and use acknowledge that the software was developed
13  * by the Internet Initiative Japan, Inc.  The name of the
14  * IIJ may not be used to endorse or promote products derived
15  * from this software without specific prior written permission.
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19  *
20  * $Id: fsm.c,v 1.18 1997/09/10 21:33:32 brian Exp $
21  *
22  *  TODO:
23  *		o Refer loglevel for log output
24  *		o Better option log display
25  */
26 #include "fsm.h"
27 #include "hdlc.h"
28 #include "lqr.h"
29 #include "lcpproto.h"
30 #include "lcp.h"
31 #include "ccp.h"
32 #include "modem.h"
33 #include "loadalias.h"
34 #include "vars.h"
35 #include "pred.h"
36 
37 void FsmSendConfigReq(struct fsm * fp);
38 void FsmSendTerminateReq(struct fsm * fp);
39 void FsmInitRestartCounter(struct fsm * fp);
40 void FsmTimeout(struct fsm * fp);
41 
42 char const *StateNames[] = {
43   "Initial", "Starting", "Closed", "Stopped", "Closing", "Stopping",
44   "Req-Sent", "Ack-Rcvd", "Ack-Sent", "Opened",
45 };
46 
47 static void
48 StoppedTimeout(struct fsm * fp)
49 {
50   LogPrintf(fp->LogLevel, "Stopped timer expired\n");
51   if (modem != -1)
52     DownConnection();
53   else
54     FsmDown(fp);
55 }
56 
57 void
58 FsmInit(struct fsm * fp)
59 {
60   LogPrintf(LogDEBUG, "FsmInit\n");
61   fp->state = ST_INITIAL;
62   fp->reqid = 1;
63   fp->restart = 1;
64   fp->maxconfig = 3;
65 }
66 
67 void
68 NewState(struct fsm * fp, int new)
69 {
70   LogPrintf(fp->LogLevel, "State change %s --> %s\n",
71 	    StateNames[fp->state], StateNames[new]);
72   if (fp->state == ST_STOPPED && fp->StoppedTimer.state == TIMER_RUNNING)
73     StopTimer(&fp->StoppedTimer);
74   fp->state = new;
75   if ((new >= ST_INITIAL && new <= ST_STOPPED) || (new == ST_OPENED)) {
76     StopTimer(&fp->FsmTimer);
77     if (new == ST_STOPPED && fp->StoppedTimer.load) {
78       fp->StoppedTimer.state = TIMER_STOPPED;
79       fp->StoppedTimer.func = StoppedTimeout;
80       fp->StoppedTimer.arg = (void *) fp;
81       StartTimer(&fp->StoppedTimer);
82     }
83   }
84 }
85 
86 void
87 FsmOutput(struct fsm * fp, u_int code, u_int id, u_char * ptr, int count)
88 {
89   int plen;
90   struct fsmheader lh;
91   struct mbuf *bp;
92 
93   plen = sizeof(struct fsmheader) + count;
94   lh.code = code;
95   lh.id = id;
96   lh.length = htons(plen);
97   bp = mballoc(plen, MB_FSM);
98   bcopy(&lh, MBUF_CTOP(bp), sizeof(struct fsmheader));
99   if (count)
100     bcopy(ptr, MBUF_CTOP(bp) + sizeof(struct fsmheader), count);
101   LogDumpBp(LogDEBUG, "FsmOutput", bp);
102   HdlcOutput(PRI_LINK, fp->proto, bp);
103 }
104 
105 void
106 FsmOpen(struct fsm * fp)
107 {
108   switch (fp->state) {
109     case ST_INITIAL:
110     (fp->LayerStart) (fp);
111     NewState(fp, ST_STARTING);
112     break;
113   case ST_STARTING:
114     break;
115   case ST_CLOSED:
116     if (fp->open_mode == OPEN_PASSIVE) {
117       NewState(fp, ST_STOPPED);
118     } else {
119       FsmInitRestartCounter(fp);
120       FsmSendConfigReq(fp);
121       NewState(fp, ST_REQSENT);
122     }
123     break;
124   case ST_STOPPED:		/* XXX: restart option */
125   case ST_REQSENT:
126   case ST_ACKRCVD:
127   case ST_ACKSENT:
128   case ST_OPENED:		/* XXX: restart option */
129     break;
130   case ST_CLOSING:		/* XXX: restart option */
131   case ST_STOPPING:		/* XXX: restart option */
132     NewState(fp, ST_STOPPING);
133     break;
134   }
135 }
136 
137 void
138 FsmUp(struct fsm * fp)
139 {
140   switch (fp->state) {
141     case ST_INITIAL:
142     NewState(fp, ST_CLOSED);
143     break;
144   case ST_STARTING:
145     FsmInitRestartCounter(fp);
146     FsmSendConfigReq(fp);
147     NewState(fp, ST_REQSENT);
148     break;
149   default:
150     LogPrintf(fp->LogLevel, "Oops, Up at %s\n", StateNames[fp->state]);
151     break;
152   }
153 }
154 
155 void
156 FsmDown(struct fsm * fp)
157 {
158   switch (fp->state) {
159     case ST_CLOSED:
160     case ST_CLOSING:
161     NewState(fp, ST_INITIAL);
162     break;
163   case ST_STOPPED:
164     (fp->LayerStart) (fp);
165     /* Fall into.. */
166   case ST_STOPPING:
167   case ST_REQSENT:
168   case ST_ACKRCVD:
169   case ST_ACKSENT:
170     NewState(fp, ST_STARTING);
171     break;
172   case ST_OPENED:
173     (fp->LayerDown) (fp);
174     NewState(fp, ST_STARTING);
175     break;
176   }
177 }
178 
179 void
180 FsmClose(struct fsm * fp)
181 {
182   switch (fp->state) {
183     case ST_STARTING:
184     NewState(fp, ST_INITIAL);
185     break;
186   case ST_STOPPED:
187     NewState(fp, ST_CLOSED);
188     break;
189   case ST_STOPPING:
190     NewState(fp, ST_CLOSING);
191     break;
192   case ST_OPENED:
193     (fp->LayerDown) (fp);
194     /* Fall down */
195   case ST_REQSENT:
196   case ST_ACKRCVD:
197   case ST_ACKSENT:
198     FsmInitRestartCounter(fp);
199     FsmSendTerminateReq(fp);
200     NewState(fp, ST_CLOSING);
201     break;
202   }
203 }
204 
205 /*
206  *	Send functions
207  */
208 void
209 FsmSendConfigReq(struct fsm * fp)
210 {
211   if (--fp->maxconfig > 0) {
212     (fp->SendConfigReq) (fp);
213     StartTimer(&fp->FsmTimer);	/* Start restart timer */
214     fp->restart--;		/* Decrement restart counter */
215   } else {
216     FsmClose(fp);
217   }
218 }
219 
220 void
221 FsmSendTerminateReq(struct fsm * fp)
222 {
223   LogPrintf(fp->LogLevel, "SendTerminateReq.\n");
224   FsmOutput(fp, CODE_TERMREQ, fp->reqid++, NULL, 0);
225   (fp->SendTerminateReq) (fp);
226   StartTimer(&fp->FsmTimer);	/* Start restart timer */
227   fp->restart--;		/* Decrement restart counter */
228 }
229 
230 static void
231 FsmSendConfigAck(struct fsm * fp,
232 		 struct fsmheader * lhp,
233 		 u_char * option,
234 		 int count)
235 {
236   LogPrintf(fp->LogLevel, "SendConfigAck(%s)\n", StateNames[fp->state]);
237   (fp->DecodeConfig) (option, count, MODE_NOP);
238   FsmOutput(fp, CODE_CONFIGACK, lhp->id, option, count);
239 }
240 
241 static void
242 FsmSendConfigRej(struct fsm * fp,
243 		 struct fsmheader * lhp,
244 		 u_char * option,
245 		 int count)
246 {
247   LogPrintf(fp->LogLevel, "SendConfigRej(%s)\n", StateNames[fp->state]);
248   (fp->DecodeConfig) (option, count, MODE_NOP);
249   FsmOutput(fp, CODE_CONFIGREJ, lhp->id, option, count);
250 }
251 
252 static void
253 FsmSendConfigNak(struct fsm * fp,
254 		 struct fsmheader * lhp,
255 		 u_char * option,
256 		 int count)
257 {
258   LogPrintf(fp->LogLevel, "SendConfigNak(%s)\n", StateNames[fp->state]);
259   (fp->DecodeConfig) (option, count, MODE_NOP);
260   FsmOutput(fp, CODE_CONFIGNAK, lhp->id, option, count);
261 }
262 
263 /*
264  *	Timeout actions
265  */
266 void
267 FsmTimeout(struct fsm * fp)
268 {
269   if (fp->restart) {
270     switch (fp->state) {
271       case ST_CLOSING:
272       case ST_STOPPING:
273       FsmSendTerminateReq(fp);
274       break;
275     case ST_REQSENT:
276     case ST_ACKSENT:
277       FsmSendConfigReq(fp);
278       break;
279     case ST_ACKRCVD:
280       FsmSendConfigReq(fp);
281       NewState(fp, ST_REQSENT);
282       break;
283     }
284     StartTimer(&fp->FsmTimer);
285   } else {
286     switch (fp->state) {
287     case ST_CLOSING:
288       NewState(fp, ST_CLOSED);
289       (fp->LayerFinish) (fp);
290       break;
291     case ST_STOPPING:
292       NewState(fp, ST_STOPPED);
293       (fp->LayerFinish) (fp);
294       break;
295     case ST_REQSENT:		/* XXX: 3p */
296     case ST_ACKSENT:
297     case ST_ACKRCVD:
298       NewState(fp, ST_STOPPED);
299       (fp->LayerFinish) (fp);
300       break;
301     }
302   }
303 }
304 
305 void
306 FsmInitRestartCounter(struct fsm * fp)
307 {
308   StopTimer(&fp->FsmTimer);
309   fp->FsmTimer.state = TIMER_STOPPED;
310   fp->FsmTimer.func = FsmTimeout;
311   fp->FsmTimer.arg = (void *) fp;
312   (fp->InitRestartCounter) (fp);
313 }
314 
315 /*
316  *   Actions when receive packets
317  */
318 void
319 FsmRecvConfigReq(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
320 /* RCR */
321 {
322   int plen, flen;
323   int ackaction = 0;
324 
325   plen = plength(bp);
326   flen = ntohs(lhp->length) - sizeof(*lhp);
327   if (plen < flen) {
328     LogPrintf(LogERROR, "FsmRecvConfigReq: plen (%d) < flen (%d)\n",
329 	      plen, flen);
330     pfree(bp);
331     return;
332   }
333 
334   /*
335    * Check and process easy case
336    */
337   switch (fp->state) {
338   case ST_INITIAL:
339   case ST_STARTING:
340     LogPrintf(fp->LogLevel, "Oops, RCR in %s.\n", StateNames[fp->state]);
341     pfree(bp);
342     return;
343   case ST_CLOSED:
344     (fp->SendTerminateAck) (fp);
345     pfree(bp);
346     return;
347   case ST_CLOSING:
348   case ST_STOPPING:
349     LogPrintf(LogERROR, "Got ConfigReq while state = %d\n", fp->state);
350     pfree(bp);
351     return;
352   }
353 
354   (fp->DecodeConfig) (MBUF_CTOP(bp), flen, MODE_REQ);
355 
356   if (nakp == NakBuff && rejp == RejBuff)
357     ackaction = 1;
358 
359   switch (fp->state) {
360   case ST_OPENED:
361     (fp->LayerDown) (fp);
362     FsmSendConfigReq(fp);
363     break;
364   case ST_STOPPED:
365     FsmInitRestartCounter(fp);
366     FsmSendConfigReq(fp);
367     break;
368   }
369 
370   if (rejp != RejBuff)
371     FsmSendConfigRej(fp, lhp, RejBuff, rejp - RejBuff);
372   if (nakp != NakBuff)
373     FsmSendConfigNak(fp, lhp, NakBuff, nakp - NakBuff);
374   if (ackaction)
375     FsmSendConfigAck(fp, lhp, AckBuff, ackp - AckBuff);
376 
377   switch (fp->state) {
378   case ST_STOPPED:
379   case ST_OPENED:
380     if (ackaction)
381       NewState(fp, ST_ACKSENT);
382     else
383       NewState(fp, ST_REQSENT);
384     break;
385   case ST_REQSENT:
386     if (ackaction)
387       NewState(fp, ST_ACKSENT);
388     break;
389   case ST_ACKRCVD:
390     if (ackaction) {
391       NewState(fp, ST_OPENED);
392       (fp->LayerUp) (fp);
393     }
394     break;
395   case ST_ACKSENT:
396     if (!ackaction)
397       NewState(fp, ST_REQSENT);
398     break;
399   }
400   pfree(bp);
401 }
402 
403 void
404 FsmRecvConfigAck(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
405 /* RCA */
406 {
407   switch (fp->state) {
408     case ST_CLOSED:
409     case ST_STOPPED:
410     (fp->SendTerminateAck) (fp);
411     break;
412   case ST_CLOSING:
413   case ST_STOPPING:
414     break;
415   case ST_REQSENT:
416     FsmInitRestartCounter(fp);
417     NewState(fp, ST_ACKRCVD);
418     break;
419   case ST_ACKRCVD:
420     FsmSendConfigReq(fp);
421     NewState(fp, ST_REQSENT);
422     break;
423   case ST_ACKSENT:
424     FsmInitRestartCounter(fp);
425     NewState(fp, ST_OPENED);
426     (fp->LayerUp) (fp);
427     break;
428   case ST_OPENED:
429     (fp->LayerDown) (fp);
430     FsmSendConfigReq(fp);
431     NewState(fp, ST_REQSENT);
432     break;
433   }
434   pfree(bp);
435 }
436 
437 void
438 FsmRecvConfigNak(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
439 /* RCN */
440 {
441   int plen, flen;
442 
443   plen = plength(bp);
444   flen = ntohs(lhp->length) - sizeof(*lhp);
445   if (plen < flen) {
446     pfree(bp);
447     return;
448   }
449 
450   /*
451    * Check and process easy case
452    */
453   switch (fp->state) {
454   case ST_INITIAL:
455   case ST_STARTING:
456     LogPrintf(fp->LogLevel, "Oops, RCN in %s.\n", StateNames[fp->state]);
457     pfree(bp);
458     return;
459   case ST_CLOSED:
460   case ST_STOPPED:
461     (fp->SendTerminateAck) (fp);
462     pfree(bp);
463     return;
464   case ST_CLOSING:
465   case ST_STOPPING:
466     pfree(bp);
467     return;
468   }
469 
470   (fp->DecodeConfig) (MBUF_CTOP(bp), flen, MODE_NAK);
471 
472   switch (fp->state) {
473   case ST_REQSENT:
474   case ST_ACKSENT:
475     FsmInitRestartCounter(fp);
476     FsmSendConfigReq(fp);
477     break;
478   case ST_OPENED:
479     (fp->LayerDown) (fp);
480     /* Fall down */
481   case ST_ACKRCVD:
482     FsmSendConfigReq(fp);
483     NewState(fp, ST_REQSENT);
484     break;
485   }
486 
487   pfree(bp);
488 }
489 
490 void
491 FsmRecvTermReq(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
492 /* RTR */
493 {
494   switch (fp->state) {
495     case ST_INITIAL:
496     case ST_STARTING:
497     LogPrintf(fp->LogLevel, "Oops, RTR in %s\n", StateNames[fp->state]);
498     break;
499   case ST_CLOSED:
500   case ST_STOPPED:
501   case ST_CLOSING:
502   case ST_STOPPING:
503   case ST_REQSENT:
504     (fp->SendTerminateAck) (fp);
505     break;
506   case ST_ACKRCVD:
507   case ST_ACKSENT:
508     (fp->SendTerminateAck) (fp);
509     NewState(fp, ST_REQSENT);
510     break;
511   case ST_OPENED:
512     (fp->LayerDown) (fp);
513     (fp->SendTerminateAck) (fp);
514     StartTimer(&fp->FsmTimer);	/* Start restart timer */
515     fp->restart = 0;
516     NewState(fp, ST_STOPPING);
517     break;
518   }
519   pfree(bp);
520 }
521 
522 void
523 FsmRecvTermAck(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
524 /* RTA */
525 {
526   switch (fp->state) {
527     case ST_CLOSING:
528     NewState(fp, ST_CLOSED);
529     (fp->LayerFinish) (fp);
530     break;
531   case ST_STOPPING:
532     NewState(fp, ST_STOPPED);
533     (fp->LayerFinish) (fp);
534     break;
535   case ST_ACKRCVD:
536     NewState(fp, ST_REQSENT);
537     break;
538   case ST_OPENED:
539     (fp->LayerDown) (fp);
540     FsmSendConfigReq(fp);
541     NewState(fp, ST_REQSENT);
542     break;
543   }
544   pfree(bp);
545 }
546 
547 void
548 FsmRecvConfigRej(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
549 /* RCJ */
550 {
551   int plen, flen;
552 
553   plen = plength(bp);
554   flen = ntohs(lhp->length) - sizeof(*lhp);
555   if (plen < flen) {
556     pfree(bp);
557     return;
558   }
559   LogPrintf(fp->LogLevel, "RecvConfigRej.\n");
560 
561   /*
562    * Check and process easy case
563    */
564   switch (fp->state) {
565   case ST_INITIAL:
566   case ST_STARTING:
567     LogPrintf(fp->LogLevel, "Oops, RCJ in %s.\n", StateNames[fp->state]);
568     pfree(bp);
569     return;
570   case ST_CLOSED:
571   case ST_STOPPED:
572     (fp->SendTerminateAck) (fp);
573     pfree(bp);
574     return;
575   case ST_CLOSING:
576   case ST_STOPPING:
577     pfree(bp);
578     return;
579   }
580 
581   (fp->DecodeConfig) (MBUF_CTOP(bp), flen, MODE_REJ);
582 
583   switch (fp->state) {
584   case ST_REQSENT:
585   case ST_ACKSENT:
586     FsmInitRestartCounter(fp);
587     FsmSendConfigReq(fp);
588     break;
589   case ST_OPENED:
590     (fp->LayerDown) (fp);
591     /* Fall down */
592   case ST_ACKRCVD:
593     FsmSendConfigReq(fp);
594     NewState(fp, ST_REQSENT);
595     break;
596   }
597   pfree(bp);
598 }
599 
600 void
601 FsmRecvCodeRej(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
602 {
603   LogPrintf(fp->LogLevel, "RecvCodeRej\n");
604   pfree(bp);
605 }
606 
607 void
608 FsmRecvProtoRej(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
609 {
610   u_short *sp, proto;
611 
612   sp = (u_short *) MBUF_CTOP(bp);
613   proto = ntohs(*sp);
614   LogPrintf(fp->LogLevel, "-- Protocol (%04x) was rejected.\n", proto);
615 
616   switch (proto) {
617   case PROTO_LQR:
618     StopLqr(LQM_LQR);
619     break;
620   case PROTO_CCP:
621     fp = &CcpFsm;
622     (fp->LayerFinish) (fp);
623     switch (fp->state) {
624     case ST_CLOSED:
625     case ST_CLOSING:
626       NewState(fp, ST_CLOSED);
627     default:
628       NewState(fp, ST_STOPPED);
629       break;
630     }
631     break;
632   }
633   pfree(bp);
634 }
635 
636 void
637 FsmRecvEchoReq(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
638 {
639   u_char *cp;
640   u_long *lp, magic;
641 
642   cp = MBUF_CTOP(bp);
643   lp = (u_long *) cp;
644   magic = ntohl(*lp);
645   if (magic != LcpInfo.his_magic) {
646     LogPrintf(LogERROR, "RecvEchoReq: his magic is bad!!\n");
647     /* XXX: We should send terminate request */
648   }
649   if (fp->state == ST_OPENED) {
650     *lp = htonl(LcpInfo.want_magic);	/* Insert local magic number */
651     LogPrintf(fp->LogLevel, "SendEchoRep(%s)\n", StateNames[fp->state]);
652     FsmOutput(fp, CODE_ECHOREP, lhp->id, cp, plength(bp));
653   }
654   pfree(bp);
655 }
656 
657 void
658 FsmRecvEchoRep(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
659 {
660   u_long *lp, magic;
661 
662   lp = (u_long *) MBUF_CTOP(bp);
663   magic = ntohl(*lp);
664 /*
665  * Tolerate echo replies with either magic number
666  */
667   if (magic != 0 && magic != LcpInfo.his_magic && magic != LcpInfo.want_magic) {
668     LogPrintf(LogERROR, "RecvEchoRep: his magic is wrong! expect: %x got: %x\n",
669 	      LcpInfo.his_magic, magic);
670 
671     /*
672      * XXX: We should send terminate request. But poor implementation may die
673      * as a result.
674      */
675   }
676   RecvEchoLqr(bp);
677   pfree(bp);
678 }
679 
680 void
681 FsmRecvDiscReq(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
682 {
683   LogPrintf(fp->LogLevel, "RecvDiscReq\n");
684   pfree(bp);
685 }
686 
687 void
688 FsmRecvIdent(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
689 {
690   LogPrintf(fp->LogLevel, "RecvIdent\n");
691   pfree(bp);
692 }
693 
694 void
695 FsmRecvTimeRemain(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
696 {
697   LogPrintf(fp->LogLevel, "RecvTimeRemain\n");
698   pfree(bp);
699 }
700 
701 void
702 FsmRecvResetReq(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
703 {
704   LogPrintf(fp->LogLevel, "RecvResetReq\n");
705   CcpRecvResetReq(fp);
706   LogPrintf(fp->LogLevel, "SendResetAck\n");
707   FsmOutput(fp, CODE_RESETACK, fp->reqid, NULL, 0);
708   pfree(bp);
709 }
710 
711 void
712 FsmRecvResetAck(struct fsm * fp, struct fsmheader * lhp, struct mbuf * bp)
713 {
714   LogPrintf(fp->LogLevel, "RecvResetAck\n");
715   Pred1Init(1);			/* Initialize Input part */
716   fp->reqid++;
717   pfree(bp);
718 }
719 
720 struct fsmcodedesc FsmCodes[] = {
721   {FsmRecvConfigReq, "Configure Request",},
722   {FsmRecvConfigAck, "Configure Ack",},
723   {FsmRecvConfigNak, "Configure Nak",},
724   {FsmRecvConfigRej, "Configure Reject",},
725   {FsmRecvTermReq, "Terminate Request",},
726   {FsmRecvTermAck, "Terminate Ack",},
727   {FsmRecvCodeRej, "Code Reject",},
728   {FsmRecvProtoRej, "Protocol Reject",},
729   {FsmRecvEchoReq, "Echo Request",},
730   {FsmRecvEchoRep, "Echo Reply",},
731   {FsmRecvDiscReq, "Discard Request",},
732   {FsmRecvIdent, "Ident",},
733   {FsmRecvTimeRemain, "Time Remain",},
734   {FsmRecvResetReq, "Reset Request",},
735   {FsmRecvResetAck, "Reset Ack",},
736 };
737 
738 void
739 FsmInput(struct fsm * fp, struct mbuf * bp)
740 {
741   int len;
742   struct fsmheader *lhp;
743   struct fsmcodedesc *codep;
744 
745   len = plength(bp);
746   if (len < sizeof(struct fsmheader)) {
747     pfree(bp);
748     return;
749   }
750   lhp = (struct fsmheader *) MBUF_CTOP(bp);
751   if (lhp->code == 0 || lhp->code > fp->max_code) {
752     pfree(bp);			/* XXX: Should send code reject */
753     return;
754   }
755   bp->offset += sizeof(struct fsmheader);
756   bp->cnt -= sizeof(struct fsmheader);
757 
758   codep = FsmCodes + lhp->code - 1;
759   LogPrintf(fp->LogLevel, "Received %s (%d) state = %s (%d)\n",
760 	    codep->name, lhp->id, StateNames[fp->state], fp->state);
761   if (LogIsKept(LogDEBUG))
762     LogMemory();
763   (codep->action) (fp, lhp, bp);
764   if (LogIsKept(LogDEBUG))
765     LogMemory();
766 }
767