usr.sbin/ppp/fsm.c

   1 /*-
   2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
   3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
   4  *                           Internet Initiative Japan, Inc (IIJ)
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/usr.sbin/ppp/fsm.c,v 1.52.2.8 2002/09/01 02:12:27 brian Exp $
  29  * $DragonFly: src/usr.sbin/ppp/fsm.c,v 1.2 2003/06/17 04:30:00 dillon Exp $
  30  */
  31
  32 #include <sys/param.h>
  33 #include <netinet/in.h>
  34 #include <netinet/in_systm.h>
  35 #include <netinet/ip.h>
  36 #include <sys/socket.h>
  37 #include <sys/un.h>
  38
  39 #include <string.h>
  40 #include <termios.h>
  41
  42 #include "layer.h"
  43 #include "ua.h"
  44 #include "mbuf.h"
  45 #include "log.h"
  46 #include "defs.h"
  47 #include "timer.h"
  48 #include "fsm.h"
  49 #include "iplist.h"
  50 #include "lqr.h"
  51 #include "hdlc.h"
  52 #include "throughput.h"
  53 #include "slcompress.h"
  54 #include "ncpaddr.h"
  55 #include "ipcp.h"
  56 #include "filter.h"
  57 #include "descriptor.h"
  58 #include "lcp.h"
  59 #include "ccp.h"
  60 #include "link.h"
  61 #include "mp.h"
  62 #ifndef NORADIUS
  63 #include "radius.h"
  64 #endif
  65 #include "ipv6cp.h"
  66 #include "ncp.h"
  67 #include "bundle.h"
  68 #include "async.h"
  69 #include "physical.h"
  70 #include "proto.h"
  71
  72 static void FsmSendConfigReq(struct fsm *);
  73 static void FsmSendTerminateReq(struct fsm *);
  74 static void FsmInitRestartCounter(struct fsm *, int);
  75
  76 typedef void (recvfn)(struct fsm *, struct fsmheader *, struct mbuf *);
  77 static recvfn FsmRecvConfigReq, FsmRecvConfigAck, FsmRecvConfigNak,
  78               FsmRecvConfigRej, FsmRecvTermReq, FsmRecvTermAck,
  79               FsmRecvCodeRej, FsmRecvProtoRej, FsmRecvEchoReq,
  80               FsmRecvEchoRep, FsmRecvDiscReq, FsmRecvIdent,
  81               FsmRecvTimeRemain, FsmRecvResetReq, FsmRecvResetAck;
  82
  83 static const struct fsmcodedesc {
  84   recvfn *recv;
  85   unsigned check_reqid : 1;
  86   unsigned inc_reqid : 1;
  87   const char *name;
  88 } FsmCodes[] = {
  89   { FsmRecvConfigReq, 0, 0, "ConfigReq"    },
  90   { FsmRecvConfigAck, 1, 1, "ConfigAck"    },
  91   { FsmRecvConfigNak, 1, 1, "ConfigNak"    },
  92   { FsmRecvConfigRej, 1, 1, "ConfigRej"    },
  93   { FsmRecvTermReq,   0, 0, "TerminateReq" },
  94   { FsmRecvTermAck,   1, 1, "TerminateAck" },
  95   { FsmRecvCodeRej,   0, 0, "CodeRej"      },
  96   { FsmRecvProtoRej,  0, 0, "ProtocolRej"  },
  97   { FsmRecvEchoReq,   0, 0, "EchoRequest"  },
  98   { FsmRecvEchoRep,   0, 0, "EchoReply"    },
  99   { FsmRecvDiscReq,   0, 0, "DiscardReq"   },
 100   { FsmRecvIdent,     0, 1, "Ident"        },
 101   { FsmRecvTimeRemain,0, 0, "TimeRemain"   },
 102   { FsmRecvResetReq,  0, 0, "ResetReq"     },
 103   { FsmRecvResetAck,  0, 1, "ResetAck"     }
 104 };
 105
 106 static const char *
 107 Code2Nam(u_int code)
 108 {
 109   if (code == 0 || code > sizeof FsmCodes / sizeof FsmCodes[0])
 110     return "Unknown";
 111   return FsmCodes[code-1].name;
 112 }
 113
 114 const char *
 115 State2Nam(u_int state)
 116 {
 117   static const char * const StateNames[] = {
 118     "Initial", "Starting", "Closed", "Stopped", "Closing", "Stopping",
 119     "Req-Sent", "Ack-Rcvd", "Ack-Sent", "Opened",
 120   };
 121
 122   if (state >= sizeof StateNames / sizeof StateNames[0])
 123     return "unknown";
 124   return StateNames[state];
 125 }
 126
 127 static void
 128 StoppedTimeout(void *v)
 129 {
 130   struct fsm *fp = (struct fsm *)v;
 131
 132   log_Printf(fp->LogLevel, "%s: Stopped timer expired\n", fp->link->name);
 133   if (fp->OpenTimer.state == TIMER_RUNNING) {
 134     log_Printf(LogWARN, "%s: %s: aborting open delay due to stopped timer\n",
 135               fp->link->name, fp->name);
 136     timer_Stop(&fp->OpenTimer);
 137   }
 138   if (fp->state == ST_STOPPED)
 139     fsm2initial(fp);
 140 }
 141
 142 void
 143 fsm_Init(struct fsm *fp, const char *name, u_short proto, int mincode,
 144          int maxcode, int LogLevel, struct bundle *bundle,
 145          struct link *l, const struct fsm_parent *parent,
 146          struct fsm_callbacks *fn, const char * const timer_names[3])
 147 {
 148   fp->name = name;
 149   fp->proto = proto;
 150   fp->min_code = mincode;
 151   fp->max_code = maxcode;
 152   fp->state = fp->min_code > CODE_TERMACK ? ST_OPENED : ST_INITIAL;
 153   fp->reqid = 1;
 154   fp->restart = 1;
 155   fp->more.reqs = fp->more.naks = fp->more.rejs = 3;
 156   memset(&fp->FsmTimer, '\0', sizeof fp->FsmTimer);
 157   memset(&fp->OpenTimer, '\0', sizeof fp->OpenTimer);
 158   memset(&fp->StoppedTimer, '\0', sizeof fp->StoppedTimer);
 159   fp->LogLevel = LogLevel;
 160   fp->link = l;
 161   fp->bundle = bundle;
 162   fp->parent = parent;
 163   fp->fn = fn;
 164   fp->FsmTimer.name = timer_names[0];
 165   fp->OpenTimer.name = timer_names[1];
 166   fp->StoppedTimer.name = timer_names[2];
 167 }
 168
 169 static void
 170 NewState(struct fsm *fp, int new)
 171 {
 172   log_Printf(fp->LogLevel, "%s: State change %s --> %s\n",
 173              fp->link->name, State2Nam(fp->state), State2Nam(new));
 174   if (fp->state == ST_STOPPED && fp->StoppedTimer.state == TIMER_RUNNING)
 175     timer_Stop(&fp->StoppedTimer);
 176   fp->state = new;
 177   if ((new >= ST_INITIAL && new <= ST_STOPPED) || (new == ST_OPENED)) {
 178     timer_Stop(&fp->FsmTimer);
 179     if (new == ST_STOPPED && fp->StoppedTimer.load) {
 180       timer_Stop(&fp->StoppedTimer);
 181       fp->StoppedTimer.func = StoppedTimeout;
 182       fp->StoppedTimer.arg = (void *) fp;
 183       timer_Start(&fp->StoppedTimer);
 184     }
 185   }
 186 }
 187
 188 void
 189 fsm_Output(struct fsm *fp, u_int code, u_int id, u_char *ptr, int count,
 190            int mtype)
 191 {
 192   int plen;
 193   struct fsmheader lh;
 194   struct mbuf *bp;
 195
 196   if (log_IsKept(fp->LogLevel)) {
 197     log_Printf(fp->LogLevel, "%s: Send%s(%d) state = %s\n",
 198               fp->link->name, Code2Nam(code), id, State2Nam(fp->state));
 199     switch (code) {
 200       case CODE_CONFIGREQ:
 201       case CODE_CONFIGACK:
 202       case CODE_CONFIGREJ:
 203       case CODE_CONFIGNAK:
 204         (*fp->fn->DecodeConfig)(fp, ptr, ptr + count, MODE_NOP, NULL);
 205         if (count < sizeof(struct fsm_opt_hdr))
 206           log_Printf(fp->LogLevel, "  [EMPTY]\n");
 207         break;
 208     }
 209   }
 210
 211   plen = sizeof(struct fsmheader) + count;
 212   lh.code = code;
 213   lh.id = id;
 214   lh.length = htons(plen);
 215   bp = m_get(plen, mtype);
 216   memcpy(MBUF_CTOP(bp), &lh, sizeof(struct fsmheader));
 217   if (count)
 218     memcpy(MBUF_CTOP(bp) + sizeof(struct fsmheader), ptr, count);
 219   log_DumpBp(LogDEBUG, "fsm_Output", bp);
 220   link_PushPacket(fp->link, bp, fp->bundle, LINK_QUEUES(fp->link) - 1,
 221                   fp->proto);
 222
 223   if (code == CODE_CONFIGREJ)
 224     lcp_SendIdentification(&fp->link->lcp);
 225 }
 226
 227 static void
 228 FsmOpenNow(void *v)
 229 {
 230   struct fsm *fp = (struct fsm *)v;
 231
 232   timer_Stop(&fp->OpenTimer);
 233   if (fp->state <= ST_STOPPED) {
 234     if (fp->state != ST_STARTING) {
 235       /*
 236        * In practice, we're only here in ST_STOPPED (when delaying the
 237        * first config request) or ST_CLOSED (when openmode == 0).
 238        *
 239        * The ST_STOPPED bit is breaking the RFC already :-(
 240        *
 241        * According to the RFC (1661) state transition table, a TLS isn't
 242        * required for an Open event when state == Closed, but the RFC
 243        * must be wrong as TLS hasn't yet been called (since the last TLF)
 244        * ie, Initial gets an `Up' event, Closing gets a RTA etc.
 245        */
 246       (*fp->fn->LayerStart)(fp);
 247       (*fp->parent->LayerStart)(fp->parent->object, fp);
 248     }
 249     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 250     FsmSendConfigReq(fp);
 251     NewState(fp, ST_REQSENT);
 252   }
 253 }
 254
 255 void
 256 fsm_Open(struct fsm *fp)
 257 {
 258   switch (fp->state) {
 259   case ST_INITIAL:
 260     NewState(fp, ST_STARTING);
 261     (*fp->fn->LayerStart)(fp);
 262     (*fp->parent->LayerStart)(fp->parent->object, fp);
 263     break;
 264   case ST_CLOSED:
 265     if (fp->open_mode == OPEN_PASSIVE) {
 266       NewState(fp, ST_STOPPED);         /* XXX: This is a hack ! */
 267     } else if (fp->open_mode > 0) {
 268       if (fp->open_mode > 1)
 269         log_Printf(LogPHASE, "%s: Entering STOPPED state for %d seconds\n",
 270                   fp->link->name, fp->open_mode);
 271       NewState(fp, ST_STOPPED);         /* XXX: This is a not-so-bad hack ! */
 272       timer_Stop(&fp->OpenTimer);
 273       fp->OpenTimer.load = fp->open_mode * SECTICKS;
 274       fp->OpenTimer.func = FsmOpenNow;
 275       fp->OpenTimer.arg = (void *)fp;
 276       timer_Start(&fp->OpenTimer);
 277     } else
 278       FsmOpenNow(fp);
 279     break;
 280   case ST_STOPPED:              /* XXX: restart option */
 281   case ST_REQSENT:
 282   case ST_ACKRCVD:
 283   case ST_ACKSENT:
 284   case ST_OPENED:               /* XXX: restart option */
 285     break;
 286   case ST_CLOSING:              /* XXX: restart option */
 287   case ST_STOPPING:             /* XXX: restart option */
 288     NewState(fp, ST_STOPPING);
 289     break;
 290   }
 291 }
 292
 293 void
 294 fsm_Up(struct fsm *fp)
 295 {
 296   switch (fp->state) {
 297   case ST_INITIAL:
 298     log_Printf(fp->LogLevel, "FSM: Using \"%s\" as a transport\n",
 299               fp->link->name);
 300     NewState(fp, ST_CLOSED);
 301     break;
 302   case ST_STARTING:
 303     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 304     FsmSendConfigReq(fp);
 305     NewState(fp, ST_REQSENT);
 306     break;
 307   default:
 308     log_Printf(fp->LogLevel, "%s: Oops, Up at %s\n",
 309               fp->link->name, State2Nam(fp->state));
 310     break;
 311   }
 312 }
 313
 314 void
 315 fsm_Down(struct fsm *fp)
 316 {
 317   switch (fp->state) {
 318   case ST_CLOSED:
 319     NewState(fp, ST_INITIAL);
 320     break;
 321   case ST_CLOSING:
 322     /* This TLF contradicts the RFC (1661), which ``misses it out'' ! */
 323     (*fp->fn->LayerFinish)(fp);
 324     NewState(fp, ST_INITIAL);
 325     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 326     break;
 327   case ST_STOPPED:
 328     NewState(fp, ST_STARTING);
 329     (*fp->fn->LayerStart)(fp);
 330     (*fp->parent->LayerStart)(fp->parent->object, fp);
 331     break;
 332   case ST_STOPPING:
 333   case ST_REQSENT:
 334   case ST_ACKRCVD:
 335   case ST_ACKSENT:
 336     NewState(fp, ST_STARTING);
 337     break;
 338   case ST_OPENED:
 339     (*fp->fn->LayerDown)(fp);
 340     NewState(fp, ST_STARTING);
 341     (*fp->parent->LayerDown)(fp->parent->object, fp);
 342     break;
 343   }
 344 }
 345
 346 void
 347 fsm_Close(struct fsm *fp)
 348 {
 349   switch (fp->state) {
 350   case ST_STARTING:
 351     (*fp->fn->LayerFinish)(fp);
 352     NewState(fp, ST_INITIAL);
 353     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 354     break;
 355   case ST_STOPPED:
 356     NewState(fp, ST_CLOSED);
 357     break;
 358   case ST_STOPPING:
 359     NewState(fp, ST_CLOSING);
 360     break;
 361   case ST_OPENED:
 362     (*fp->fn->LayerDown)(fp);
 363     if (fp->state == ST_OPENED) {
 364       FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 365       FsmSendTerminateReq(fp);
 366       NewState(fp, ST_CLOSING);
 367       (*fp->parent->LayerDown)(fp->parent->object, fp);
 368     }
 369     break;
 370   case ST_REQSENT:
 371   case ST_ACKRCVD:
 372   case ST_ACKSENT:
 373     FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 374     FsmSendTerminateReq(fp);
 375     NewState(fp, ST_CLOSING);
 376     break;
 377   }
 378 }
 379
 380 /*
 381  *      Send functions
 382  */
 383 static void
 384 FsmSendConfigReq(struct fsm *fp)
 385 {
 386   if (fp->more.reqs-- > 0 && fp->restart-- > 0) {
 387     (*fp->fn->SendConfigReq)(fp);
 388     timer_Start(&fp->FsmTimer);         /* Start restart timer */
 389   } else {
 390     if (fp->more.reqs < 0)
 391       log_Printf(LogPHASE, "%s: Too many %s REQs sent - abandoning "
 392                  "negotiation\n", fp->link->name, fp->name);
 393     lcp_SendIdentification(&fp->link->lcp);
 394     fsm_Close(fp);
 395   }
 396 }
 397
 398 static void
 399 FsmSendTerminateReq(struct fsm *fp)
 400 {
 401   fsm_Output(fp, CODE_TERMREQ, fp->reqid, NULL, 0, MB_UNKNOWN);
 402   (*fp->fn->SentTerminateReq)(fp);
 403   timer_Start(&fp->FsmTimer);   /* Start restart timer */
 404   fp->restart--;                /* Decrement restart counter */
 405 }
 406
 407 /*
 408  *      Timeout actions
 409  */
 410 static void
 411 FsmTimeout(void *v)
 412 {
 413   struct fsm *fp = (struct fsm *)v;
 414
 415   if (fp->restart) {
 416     switch (fp->state) {
 417     case ST_CLOSING:
 418     case ST_STOPPING:
 419       FsmSendTerminateReq(fp);
 420       break;
 421     case ST_REQSENT:
 422     case ST_ACKSENT:
 423       FsmSendConfigReq(fp);
 424       break;
 425     case ST_ACKRCVD:
 426       FsmSendConfigReq(fp);
 427       NewState(fp, ST_REQSENT);
 428       break;
 429     }
 430     timer_Start(&fp->FsmTimer);
 431   } else {
 432     switch (fp->state) {
 433     case ST_CLOSING:
 434       (*fp->fn->LayerFinish)(fp);
 435       NewState(fp, ST_CLOSED);
 436       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 437       break;
 438     case ST_STOPPING:
 439       (*fp->fn->LayerFinish)(fp);
 440       NewState(fp, ST_STOPPED);
 441       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 442       break;
 443     case ST_REQSENT:            /* XXX: 3p */
 444     case ST_ACKSENT:
 445     case ST_ACKRCVD:
 446       (*fp->fn->LayerFinish)(fp);
 447       NewState(fp, ST_STOPPED);
 448       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 449       break;
 450     }
 451   }
 452 }
 453
 454 static void
 455 FsmInitRestartCounter(struct fsm *fp, int what)
 456 {
 457   timer_Stop(&fp->FsmTimer);
 458   fp->FsmTimer.func = FsmTimeout;
 459   fp->FsmTimer.arg = (void *)fp;
 460   (*fp->fn->InitRestartCounter)(fp, what);
 461 }
 462
 463 /*
 464  * Actions when receive packets
 465  */
 466 static void
 467 FsmRecvConfigReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 468 /* RCR */
 469 {
 470   struct fsm_decode dec;
 471   int plen, flen;
 472   int ackaction = 0;
 473   u_char *cp;
 474
 475   bp = m_pullup(bp);
 476   plen = m_length(bp);
 477   flen = ntohs(lhp->length) - sizeof *lhp;
 478   if (plen < flen) {
 479     log_Printf(LogWARN, "%s: FsmRecvConfigReq: plen (%d) < flen (%d)\n",
 480                fp->link->name, plen, flen);
 481     m_freem(bp);
 482     return;
 483   }
 484
 485   /* Some things must be done before we Decode the packet */
 486   switch (fp->state) {
 487   case ST_OPENED:
 488     (*fp->fn->LayerDown)(fp);
 489   }
 490
 491   dec.ackend = dec.ack;
 492   dec.nakend = dec.nak;
 493   dec.rejend = dec.rej;
 494   cp = MBUF_CTOP(bp);
 495   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_REQ, &dec);
 496   if (flen < sizeof(struct fsm_opt_hdr))
 497     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 498
 499   if (dec.nakend == dec.nak && dec.rejend == dec.rej)
 500     ackaction = 1;
 501
 502   /* Check and process easy case */
 503   switch (fp->state) {
 504   case ST_INITIAL:
 505     if (fp->proto == PROTO_CCP && fp->link->lcp.fsm.state == ST_OPENED) {
 506       /*
 507        * ccp_SetOpenMode() leaves us in initial if we're disabling
 508        * & denying everything.
 509        */
 510       bp = m_prepend(bp, lhp, sizeof *lhp, 2);
 511       bp = proto_Prepend(bp, fp->proto, 0, 0);
 512       bp = m_pullup(bp);
 513       lcp_SendProtoRej(&fp->link->lcp, MBUF_CTOP(bp), bp->m_len);
 514       m_freem(bp);
 515       return;
 516     }
 517     /* Drop through */
 518   case ST_STARTING:
 519     log_Printf(fp->LogLevel, "%s: Oops, RCR in %s.\n",
 520               fp->link->name, State2Nam(fp->state));
 521     m_freem(bp);
 522     return;
 523   case ST_CLOSED:
 524     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 525     m_freem(bp);
 526     return;
 527   case ST_CLOSING:
 528     log_Printf(fp->LogLevel, "%s: Error: Got ConfigReq while state = %s\n",
 529               fp->link->name, State2Nam(fp->state));
 530   case ST_STOPPING:
 531     m_freem(bp);
 532     return;
 533   case ST_STOPPED:
 534     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 535     /* Drop through */
 536   case ST_OPENED:
 537     FsmSendConfigReq(fp);
 538     break;
 539   }
 540
 541   if (dec.rejend != dec.rej)
 542     fsm_Output(fp, CODE_CONFIGREJ, lhp->id, dec.rej, dec.rejend - dec.rej,
 543                MB_UNKNOWN);
 544   if (dec.nakend != dec.nak)
 545     fsm_Output(fp, CODE_CONFIGNAK, lhp->id, dec.nak, dec.nakend - dec.nak,
 546                MB_UNKNOWN);
 547   if (ackaction)
 548     fsm_Output(fp, CODE_CONFIGACK, lhp->id, dec.ack, dec.ackend - dec.ack,
 549                MB_UNKNOWN);
 550
 551   switch (fp->state) {
 552   case ST_STOPPED:
 553       /*
 554        * According to the RFC (1661) state transition table, a TLS isn't
 555        * required for a RCR when state == ST_STOPPED, but the RFC
 556        * must be wrong as TLS hasn't yet been called (since the last TLF)
 557        */
 558     (*fp->fn->LayerStart)(fp);
 559     (*fp->parent->LayerStart)(fp->parent->object, fp);
 560     /* FALLTHROUGH */
 561
 562   case ST_OPENED:
 563     if (ackaction)
 564       NewState(fp, ST_ACKSENT);
 565     else
 566       NewState(fp, ST_REQSENT);
 567     (*fp->parent->LayerDown)(fp->parent->object, fp);
 568     break;
 569   case ST_REQSENT:
 570     if (ackaction)
 571       NewState(fp, ST_ACKSENT);
 572     break;
 573   case ST_ACKRCVD:
 574     if (ackaction) {
 575       NewState(fp, ST_OPENED);
 576       if ((*fp->fn->LayerUp)(fp))
 577         (*fp->parent->LayerUp)(fp->parent->object, fp);
 578       else {
 579         (*fp->fn->LayerDown)(fp);
 580         FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 581         FsmSendTerminateReq(fp);
 582         NewState(fp, ST_CLOSING);
 583         lcp_SendIdentification(&fp->link->lcp);
 584       }
 585     }
 586     break;
 587   case ST_ACKSENT:
 588     if (!ackaction)
 589       NewState(fp, ST_REQSENT);
 590     break;
 591   }
 592   m_freem(bp);
 593
 594   if (dec.rejend != dec.rej && --fp->more.rejs <= 0) {
 595     log_Printf(LogPHASE, "%s: Too many %s REJs sent - abandoning negotiation\n",
 596                fp->link->name, fp->name);
 597     lcp_SendIdentification(&fp->link->lcp);
 598     fsm_Close(fp);
 599   }
 600
 601   if (dec.nakend != dec.nak && --fp->more.naks <= 0) {
 602     log_Printf(LogPHASE, "%s: Too many %s NAKs sent - abandoning negotiation\n",
 603                fp->link->name, fp->name);
 604     lcp_SendIdentification(&fp->link->lcp);
 605     fsm_Close(fp);
 606   }
 607 }
 608
 609 static void
 610 FsmRecvConfigAck(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 611 /* RCA */
 612 {
 613   struct fsm_decode dec;
 614   int plen, flen;
 615   u_char *cp;
 616
 617   plen = m_length(bp);
 618   flen = ntohs(lhp->length) - sizeof *lhp;
 619   if (plen < flen) {
 620     m_freem(bp);
 621     return;
 622   }
 623
 624   bp = m_pullup(bp);
 625   dec.ackend = dec.ack;
 626   dec.nakend = dec.nak;
 627   dec.rejend = dec.rej;
 628   cp = MBUF_CTOP(bp);
 629   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_ACK, &dec);
 630   if (flen < sizeof(struct fsm_opt_hdr))
 631     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 632
 633   switch (fp->state) {
 634     case ST_CLOSED:
 635     case ST_STOPPED:
 636     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 637     break;
 638   case ST_CLOSING:
 639   case ST_STOPPING:
 640     break;
 641   case ST_REQSENT:
 642     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 643     NewState(fp, ST_ACKRCVD);
 644     break;
 645   case ST_ACKRCVD:
 646     FsmSendConfigReq(fp);
 647     NewState(fp, ST_REQSENT);
 648     break;
 649   case ST_ACKSENT:
 650     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 651     NewState(fp, ST_OPENED);
 652     if ((*fp->fn->LayerUp)(fp))
 653       (*fp->parent->LayerUp)(fp->parent->object, fp);
 654     else {
 655       (*fp->fn->LayerDown)(fp);
 656       FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 657       FsmSendTerminateReq(fp);
 658       NewState(fp, ST_CLOSING);
 659       lcp_SendIdentification(&fp->link->lcp);
 660     }
 661     break;
 662   case ST_OPENED:
 663     (*fp->fn->LayerDown)(fp);
 664     FsmSendConfigReq(fp);
 665     NewState(fp, ST_REQSENT);
 666     (*fp->parent->LayerDown)(fp->parent->object, fp);
 667     break;
 668   }
 669   m_freem(bp);
 670 }
 671
 672 static void
 673 FsmRecvConfigNak(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 674 /* RCN */
 675 {
 676   struct fsm_decode dec;
 677   int plen, flen;
 678   u_char *cp;
 679
 680   plen = m_length(bp);
 681   flen = ntohs(lhp->length) - sizeof *lhp;
 682   if (plen < flen) {
 683     m_freem(bp);
 684     return;
 685   }
 686
 687   /*
 688    * Check and process easy case
 689    */
 690   switch (fp->state) {
 691   case ST_INITIAL:
 692   case ST_STARTING:
 693     log_Printf(fp->LogLevel, "%s: Oops, RCN in %s.\n",
 694               fp->link->name, State2Nam(fp->state));
 695     m_freem(bp);
 696     return;
 697   case ST_CLOSED:
 698   case ST_STOPPED:
 699     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 700     m_freem(bp);
 701     return;
 702   case ST_CLOSING:
 703   case ST_STOPPING:
 704     m_freem(bp);
 705     return;
 706   }
 707
 708   bp = m_pullup(bp);
 709   dec.ackend = dec.ack;
 710   dec.nakend = dec.nak;
 711   dec.rejend = dec.rej;
 712   cp = MBUF_CTOP(bp);
 713   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_NAK, &dec);
 714   if (flen < sizeof(struct fsm_opt_hdr))
 715     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 716
 717   switch (fp->state) {
 718   case ST_REQSENT:
 719   case ST_ACKSENT:
 720     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 721     FsmSendConfigReq(fp);
 722     break;
 723   case ST_OPENED:
 724     (*fp->fn->LayerDown)(fp);
 725     FsmSendConfigReq(fp);
 726     NewState(fp, ST_REQSENT);
 727     (*fp->parent->LayerDown)(fp->parent->object, fp);
 728     break;
 729   case ST_ACKRCVD:
 730     FsmSendConfigReq(fp);
 731     NewState(fp, ST_REQSENT);
 732     break;
 733   }
 734
 735   m_freem(bp);
 736 }
 737
 738 static void
 739 FsmRecvTermReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 740 /* RTR */
 741 {
 742   switch (fp->state) {
 743   case ST_INITIAL:
 744   case ST_STARTING:
 745     log_Printf(fp->LogLevel, "%s: Oops, RTR in %s\n",
 746               fp->link->name, State2Nam(fp->state));
 747     break;
 748   case ST_CLOSED:
 749   case ST_STOPPED:
 750   case ST_CLOSING:
 751   case ST_STOPPING:
 752   case ST_REQSENT:
 753     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 754     break;
 755   case ST_ACKRCVD:
 756   case ST_ACKSENT:
 757     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 758     NewState(fp, ST_REQSENT);
 759     break;
 760   case ST_OPENED:
 761     (*fp->fn->LayerDown)(fp);
 762     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 763     FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 764     timer_Start(&fp->FsmTimer);                 /* Start restart timer */
 765     fp->restart = 0;
 766     NewState(fp, ST_STOPPING);
 767     (*fp->parent->LayerDown)(fp->parent->object, fp);
 768     /* A delayed ST_STOPPED is now scheduled */
 769     break;
 770   }
 771   m_freem(bp);
 772 }
 773
 774 static void
 775 FsmRecvTermAck(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 776 /* RTA */
 777 {
 778   switch (fp->state) {
 779   case ST_CLOSING:
 780     (*fp->fn->LayerFinish)(fp);
 781     NewState(fp, ST_CLOSED);
 782     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 783     break;
 784   case ST_STOPPING:
 785     (*fp->fn->LayerFinish)(fp);
 786     NewState(fp, ST_STOPPED);
 787     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 788     break;
 789   case ST_ACKRCVD:
 790     NewState(fp, ST_REQSENT);
 791     break;
 792   case ST_OPENED:
 793     (*fp->fn->LayerDown)(fp);
 794     FsmSendConfigReq(fp);
 795     NewState(fp, ST_REQSENT);
 796     (*fp->parent->LayerDown)(fp->parent->object, fp);
 797     break;
 798   }
 799   m_freem(bp);
 800 }
 801
 802 static void
 803 FsmRecvConfigRej(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 804 /* RCJ */
 805 {
 806   struct fsm_decode dec;
 807   int plen, flen;
 808   u_char *cp;
 809
 810   plen = m_length(bp);
 811   flen = ntohs(lhp->length) - sizeof *lhp;
 812   if (plen < flen) {
 813     m_freem(bp);
 814     return;
 815   }
 816
 817   lcp_SendIdentification(&fp->link->lcp);
 818
 819   /*
 820    * Check and process easy case
 821    */
 822   switch (fp->state) {
 823   case ST_INITIAL:
 824   case ST_STARTING:
 825     log_Printf(fp->LogLevel, "%s: Oops, RCJ in %s.\n",
 826               fp->link->name, State2Nam(fp->state));
 827     m_freem(bp);
 828     return;
 829   case ST_CLOSED:
 830   case ST_STOPPED:
 831     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 832     m_freem(bp);
 833     return;
 834   case ST_CLOSING:
 835   case ST_STOPPING:
 836     m_freem(bp);
 837     return;
 838   }
 839
 840   bp = m_pullup(bp);
 841   dec.ackend = dec.ack;
 842   dec.nakend = dec.nak;
 843   dec.rejend = dec.rej;
 844   cp = MBUF_CTOP(bp);
 845   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_REJ, &dec);
 846   if (flen < sizeof(struct fsm_opt_hdr))
 847     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 848
 849   switch (fp->state) {
 850   case ST_REQSENT:
 851   case ST_ACKSENT:
 852     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 853     FsmSendConfigReq(fp);
 854     break;
 855   case ST_OPENED:
 856     (*fp->fn->LayerDown)(fp);
 857     FsmSendConfigReq(fp);
 858     NewState(fp, ST_REQSENT);
 859     (*fp->parent->LayerDown)(fp->parent->object, fp);
 860     break;
 861   case ST_ACKRCVD:
 862     FsmSendConfigReq(fp);
 863     NewState(fp, ST_REQSENT);
 864     break;
 865   }
 866   m_freem(bp);
 867 }
 868
 869 static void
 870 FsmRecvCodeRej(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 871 {
 872   m_freem(bp);
 873 }
 874
 875 static void
 876 FsmRecvProtoRej(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 877 {
 878   struct physical *p = link2physical(fp->link);
 879   u_short proto;
 880
 881   if (m_length(bp) < 2) {
 882     m_freem(bp);
 883     return;
 884   }
 885   bp = mbuf_Read(bp, &proto, 2);
 886   proto = ntohs(proto);
 887   log_Printf(fp->LogLevel, "%s: -- Protocol 0x%04x (%s) was rejected!\n",
 888             fp->link->name, proto, hdlc_Protocol2Nam(proto));
 889
 890   switch (proto) {
 891   case PROTO_LQR:
 892     if (p)
 893       lqr_Stop(p, LQM_LQR);
 894     else
 895       log_Printf(LogERROR, "%s: FsmRecvProtoRej: Not a physical link !\n",
 896                 fp->link->name);
 897     break;
 898   case PROTO_CCP:
 899     if (fp->proto == PROTO_LCP) {
 900       fp = &fp->link->ccp.fsm;
 901       /* Despite the RFC (1661), don't do an out-of-place TLF */
 902       /* (*fp->fn->LayerFinish)(fp); */
 903       switch (fp->state) {
 904       case ST_CLOSED:
 905       case ST_CLOSING:
 906         NewState(fp, ST_CLOSED);
 907         break;
 908       default:
 909         NewState(fp, ST_STOPPED);
 910         break;
 911       }
 912       /* See above */
 913       /* (*fp->parent->LayerFinish)(fp->parent->object, fp); */
 914     }
 915     break;
 916   case PROTO_IPCP:
 917     if (fp->proto == PROTO_LCP) {
 918       log_Printf(LogPHASE, "%s: IPCP protocol reject closes IPCP !\n",
 919                 fp->link->name);
 920       fsm_Close(&fp->bundle->ncp.ipcp.fsm);
 921     }
 922     break;
 923 #ifndef NOINET6
 924   case PROTO_IPV6CP:
 925     if (fp->proto == PROTO_LCP) {
 926       log_Printf(LogPHASE, "%s: IPV6CP protocol reject closes IPV6CP !\n",
 927                 fp->link->name);
 928       fsm_Close(&fp->bundle->ncp.ipv6cp.fsm);
 929     }
 930     break;
 931 #endif
 932   case PROTO_MP:
 933     if (fp->proto == PROTO_LCP) {
 934       struct lcp *lcp = fsm2lcp(fp);
 935
 936       if (lcp->want_mrru && lcp->his_mrru) {
 937         log_Printf(LogPHASE, "%s: MP protocol reject is fatal !\n",
 938                   fp->link->name);
 939         fsm_Close(fp);
 940       }
 941     }
 942     break;
 943   }
 944   m_freem(bp);
 945 }
 946
 947 static void
 948 FsmRecvEchoReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 949 {
 950   struct lcp *lcp = fsm2lcp(fp);
 951   u_char *cp;
 952   u_int32_t magic;
 953
 954   bp = m_pullup(bp);
 955   m_settype(bp, MB_ECHOIN);
 956
 957   if (lcp && ntohs(lhp->length) - sizeof *lhp >= 4) {
 958     cp = MBUF_CTOP(bp);
 959     ua_ntohl(cp, &magic);
 960     if (magic != lcp->his_magic) {
 961       log_Printf(fp->LogLevel, "%s: RecvEchoReq: magic 0x%08lx is wrong,"
 962                  " expecting 0x%08lx\n", fp->link->name, (u_long)magic,
 963                  (u_long)lcp->his_magic);
 964       /* XXX: We should send terminate request */
 965     }
 966     if (fp->state == ST_OPENED) {
 967       ua_htonl(&lcp->want_magic, cp);           /* local magic */
 968       fsm_Output(fp, CODE_ECHOREP, lhp->id, cp,
 969                  ntohs(lhp->length) - sizeof *lhp, MB_ECHOOUT);
 970     }
 971   }
 972   m_freem(bp);
 973 }
 974
 975 static void
 976 FsmRecvEchoRep(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 977 {
 978   if (fsm2lcp(fp))
 979     bp = lqr_RecvEcho(fp, bp);
 980
 981   m_freem(bp);
 982 }
 983
 984 static void
 985 FsmRecvDiscReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 986 {
 987   m_freem(bp);
 988 }
 989
 990 static void
 991 FsmRecvIdent(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 992 {
 993   u_int32_t magic;
 994   u_short len;
 995   u_char *cp;
 996
 997   len = ntohs(lhp->length) - sizeof *lhp;
 998   if (len >= 4) {
 999     bp = m_pullup(m_append(bp, "", 1));
1000     cp = MBUF_CTOP(bp);
1001     ua_ntohl(cp, &magic);
1002     if (magic != fp->link->lcp.his_magic)
1003       log_Printf(fp->LogLevel, "%s: RecvIdent: magic 0x%08lx is wrong,"
1004                  " expecting 0x%08lx\n", fp->link->name, (u_long)magic,
1005                  (u_long)fp->link->lcp.his_magic);
1006     cp[len] = '\0';
1007     lcp_RecvIdentification(&fp->link->lcp, cp + 4);
1008   }
1009   m_freem(bp);
1010 }
1011
1012 static void
1013 FsmRecvTimeRemain(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
1014 {
1015   m_freem(bp);
1016 }
1017
1018 static void
1019 FsmRecvResetReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
1020 {
1021   if ((*fp->fn->RecvResetReq)(fp)) {
1022     /*
1023      * All sendable compressed packets are queued in the first (lowest
1024      * priority) modem output queue.... dump 'em to the priority queue
1025      * so that they arrive at the peer before our ResetAck.
1026      */
1027     link_SequenceQueue(fp->link);
1028     fsm_Output(fp, CODE_RESETACK, lhp->id, NULL, 0, MB_CCPOUT);
1029   }
1030   m_freem(bp);
1031 }
1032
1033 static void
1034 FsmRecvResetAck(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
1035 {
1036   (*fp->fn->RecvResetAck)(fp, lhp->id);
1037   m_freem(bp);
1038 }
1039
1040 void
1041 fsm_Input(struct fsm *fp, struct mbuf *bp)
1042 {
1043   int len;
1044   struct fsmheader lh;
1045   const struct fsmcodedesc *codep;
1046
1047   len = m_length(bp);
1048   if (len < sizeof(struct fsmheader)) {
1049     m_freem(bp);
1050     return;
1051   }
1052   bp = mbuf_Read(bp, &lh, sizeof lh);
1053
1054   if (ntohs(lh.length) > len) {
1055     log_Printf(LogWARN, "%s: Oops: Got %d bytes but %d byte payload "
1056                "- dropped\n", fp->link->name, len, (int)ntohs(lh.length));
1057     m_freem(bp);
1058     return;
1059   }
1060
1061   if (lh.code < fp->min_code || lh.code > fp->max_code ||
1062       lh.code > sizeof FsmCodes / sizeof *FsmCodes) {
1063     /*
1064      * Use a private id.  This is really a response-type packet, but we
1065      * MUST send a unique id for each REQ....
1066      */
1067     static u_char id;
1068
1069     bp = m_prepend(bp, &lh, sizeof lh, 0);
1070     bp = m_pullup(bp);
1071     fsm_Output(fp, CODE_CODEREJ, id++, MBUF_CTOP(bp), bp->m_len, MB_UNKNOWN);
1072     m_freem(bp);
1073     return;
1074   }
1075
1076   codep = FsmCodes + lh.code - 1;
1077   if (lh.id != fp->reqid && codep->check_reqid &&
1078       Enabled(fp->bundle, OPT_IDCHECK)) {
1079     log_Printf(fp->LogLevel, "%s: Recv%s(%d), dropped (expected %d)\n",
1080                fp->link->name, codep->name, lh.id, fp->reqid);
1081     return;
1082   }
1083
1084   log_Printf(fp->LogLevel, "%s: Recv%s(%d) state = %s\n",
1085              fp->link->name, codep->name, lh.id, State2Nam(fp->state));
1086
1087   if (codep->inc_reqid && (lh.id == fp->reqid ||
1088       (!Enabled(fp->bundle, OPT_IDCHECK) && codep->check_reqid)))
1089     fp->reqid++;        /* That's the end of that ``exchange''.... */
1090
1091   (*codep->recv)(fp, &lh, bp);
1092 }
1093
1094 int
1095 fsm_NullRecvResetReq(struct fsm *fp)
1096 {
1097   log_Printf(fp->LogLevel, "%s: Oops - received unexpected reset req\n",
1098             fp->link->name);
1099   return 1;
1100 }
1101
1102 void
1103 fsm_NullRecvResetAck(struct fsm *fp, u_char id)
1104 {
1105   log_Printf(fp->LogLevel, "%s: Oops - received unexpected reset ack\n",
1106             fp->link->name);
1107 }
1108
1109 void
1110 fsm_Reopen(struct fsm *fp)
1111 {
1112   if (fp->state == ST_OPENED) {
1113     (*fp->fn->LayerDown)(fp);
1114     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
1115     FsmSendConfigReq(fp);
1116     NewState(fp, ST_REQSENT);
1117     (*fp->parent->LayerDown)(fp->parent->object, fp);
1118   }
1119 }
1120
1121 void
1122 fsm2initial(struct fsm *fp)
1123 {
1124   timer_Stop(&fp->FsmTimer);
1125   timer_Stop(&fp->OpenTimer);
1126   timer_Stop(&fp->StoppedTimer);
1127   if (fp->state == ST_STOPPED)
1128     fsm_Close(fp);
1129   if (fp->state > ST_INITIAL)
1130     fsm_Down(fp);
1131   if (fp->state > ST_INITIAL)
1132     fsm_Close(fp);
1133 }
1134
1135 struct fsm_opt *
1136 fsm_readopt(u_char **cp)
1137 {
1138   struct fsm_opt *o = (struct fsm_opt *)*cp;
1139
1140   if (o->hdr.len < sizeof(struct fsm_opt_hdr)) {
1141     log_Printf(LogERROR, "Bad option length %d (out of phase?)\n", o->hdr.len);
1142     return NULL;
1143   }
1144
1145   *cp += o->hdr.len;
1146
1147   if (o->hdr.len > sizeof(struct fsm_opt)) {
1148     log_Printf(LogERROR, "Warning: Truncating option length from %d to %d\n",
1149                o->hdr.len, (int)sizeof(struct fsm_opt));
1150     o->hdr.len = sizeof(struct fsm_opt);
1151   }
1152
1153   return o;
1154 }
1155
1156 static int
1157 fsm_opt(u_char *opt, int optlen, const struct fsm_opt *o)
1158 {
1159   int cplen = o->hdr.len;
1160
1161   if (optlen < sizeof(struct fsm_opt_hdr))
1162     optlen = 0;
1163
1164   if (cplen > optlen) {
1165     log_Printf(LogERROR, "Can't REJ length %d - trunating to %d\n",
1166       cplen, optlen);
1167     cplen = optlen;
1168   }
1169   memcpy(opt, o, cplen);
1170   if (cplen)
1171     opt[1] = cplen;
1172
1173   return cplen;
1174 }
1175
1176 void
1177 fsm_rej(struct fsm_decode *dec, const struct fsm_opt *o)
1178 {
1179   if (!dec)
1180     return;
1181   dec->rejend += fsm_opt(dec->rejend, FSM_OPTLEN - (dec->rejend - dec->rej), o);
1182 }
1183
1184 void
1185 fsm_ack(struct fsm_decode *dec, const struct fsm_opt *o)
1186 {
1187   if (!dec)
1188     return;
1189   dec->ackend += fsm_opt(dec->ackend, FSM_OPTLEN - (dec->ackend - dec->ack), o);
1190 }
1191
1192 void
1193 fsm_nak(struct fsm_decode *dec, const struct fsm_opt *o)
1194 {
1195   if (!dec)
1196     return;
1197   dec->nakend += fsm_opt(dec->nakend, FSM_OPTLEN - (dec->nakend - dec->nak), o);
1198 }
1199
1200 void
1201 fsm_opt_normalise(struct fsm_decode *dec)
1202 {
1203   if (dec->rejend != dec->rej) {
1204     /* rejects are preferred */
1205     dec->ackend = dec->ack;
1206     dec->nakend = dec->nak;
1207   } else if (dec->nakend != dec->nak)
1208     /* then NAKs */
1209     dec->ackend = dec->ack;
1210 }