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  */
  30
  31 #include <sys/param.h>
  32 #include <netinet/in.h>
  33 #include <netinet/in_systm.h>
  34 #include <netinet/ip.h>
  35 #include <sys/socket.h>
  36 #include <sys/un.h>
  37
  38 #include <string.h>
  39 #include <termios.h>
  40
  41 #include "layer.h"
  42 #include "ua.h"
  43 #include "mbuf.h"
  44 #include "log.h"
  45 #include "defs.h"
  46 #include "timer.h"
  47 #include "fsm.h"
  48 #include "iplist.h"
  49 #include "lqr.h"
  50 #include "hdlc.h"
  51 #include "throughput.h"
  52 #include "slcompress.h"
  53 #include "ncpaddr.h"
  54 #include "ipcp.h"
  55 #include "filter.h"
  56 #include "descriptor.h"
  57 #include "lcp.h"
  58 #include "ccp.h"
  59 #include "link.h"
  60 #include "mp.h"
  61 #ifndef NORADIUS
  62 #include "radius.h"
  63 #endif
  64 #include "ipv6cp.h"
  65 #include "ncp.h"
  66 #include "bundle.h"
  67 #include "async.h"
  68 #include "physical.h"
  69 #include "proto.h"
  70
  71 static void FsmSendConfigReq(struct fsm *);
  72 static void FsmSendTerminateReq(struct fsm *);
  73 static void FsmInitRestartCounter(struct fsm *, int);
  74
  75 typedef void (recvfn)(struct fsm *, struct fsmheader *, struct mbuf *);
  76 static recvfn FsmRecvConfigReq, FsmRecvConfigAck, FsmRecvConfigNak,
  77               FsmRecvConfigRej, FsmRecvTermReq, FsmRecvTermAck,
  78               FsmRecvCodeRej, FsmRecvProtoRej, FsmRecvEchoReq,
  79               FsmRecvEchoRep, FsmRecvDiscReq, FsmRecvIdent,
  80               FsmRecvTimeRemain, FsmRecvResetReq, FsmRecvResetAck;
  81
  82 static const struct fsmcodedesc {
  83   recvfn *recv;
  84   unsigned check_reqid : 1;
  85   unsigned inc_reqid : 1;
  86   const char *name;
  87 } FsmCodes[] = {
  88   { FsmRecvConfigReq, 0, 0, "ConfigReq"    },
  89   { FsmRecvConfigAck, 1, 1, "ConfigAck"    },
  90   { FsmRecvConfigNak, 1, 1, "ConfigNak"    },
  91   { FsmRecvConfigRej, 1, 1, "ConfigRej"    },
  92   { FsmRecvTermReq,   0, 0, "TerminateReq" },
  93   { FsmRecvTermAck,   1, 1, "TerminateAck" },
  94   { FsmRecvCodeRej,   0, 0, "CodeRej"      },
  95   { FsmRecvProtoRej,  0, 0, "ProtocolRej"  },
  96   { FsmRecvEchoReq,   0, 0, "EchoRequest"  },
  97   { FsmRecvEchoRep,   0, 0, "EchoReply"    },
  98   { FsmRecvDiscReq,   0, 0, "DiscardReq"   },
  99   { FsmRecvIdent,     0, 1, "Ident"        },
 100   { FsmRecvTimeRemain,0, 0, "TimeRemain"   },
 101   { FsmRecvResetReq,  0, 0, "ResetReq"     },
 102   { FsmRecvResetAck,  0, 1, "ResetAck"     }
 103 };
 104
 105 static const char *
 106 Code2Nam(u_int code)
 107 {
 108   if (code == 0 || code > NELEM(FsmCodes))
 109     return "Unknown";
 110   return FsmCodes[code-1].name;
 111 }
 112
 113 const char *
 114 State2Nam(u_int state)
 115 {
 116   static const char * const StateNames[] = {
 117     "Initial", "Starting", "Closed", "Stopped", "Closing", "Stopping",
 118     "Req-Sent", "Ack-Rcvd", "Ack-Sent", "Opened",
 119   };
 120
 121   if (state >= NELEM(StateNames))
 122     return "unknown";
 123   return StateNames[state];
 124 }
 125
 126 static void
 127 StoppedTimeout(void *v)
 128 {
 129   struct fsm *fp = (struct fsm *)v;
 130
 131   log_Printf(fp->LogLevel, "%s: Stopped timer expired\n", fp->link->name);
 132   if (fp->OpenTimer.state == TIMER_RUNNING) {
 133     log_Printf(LogWARN, "%s: %s: aborting open delay due to stopped timer\n",
 134               fp->link->name, fp->name);
 135     timer_Stop(&fp->OpenTimer);
 136   }
 137   if (fp->state == ST_STOPPED)
 138     fsm2initial(fp);
 139 }
 140
 141 void
 142 fsm_Init(struct fsm *fp, const char *name, u_short proto, int mincode,
 143          int maxcode, int LogLevel, struct bundle *bundle,
 144          struct link *l, const struct fsm_parent *parent,
 145          struct fsm_callbacks *fn, const char * const timer_names[3])
 146 {
 147   fp->name = name;
 148   fp->proto = proto;
 149   fp->min_code = mincode;
 150   fp->max_code = maxcode;
 151   fp->state = fp->min_code > CODE_TERMACK ? ST_OPENED : ST_INITIAL;
 152   fp->reqid = 1;
 153   fp->restart = 1;
 154   fp->more.reqs = fp->more.naks = fp->more.rejs = 3;
 155   memset(&fp->FsmTimer, '\0', sizeof fp->FsmTimer);
 156   memset(&fp->OpenTimer, '\0', sizeof fp->OpenTimer);
 157   memset(&fp->StoppedTimer, '\0', sizeof fp->StoppedTimer);
 158   fp->LogLevel = LogLevel;
 159   fp->link = l;
 160   fp->bundle = bundle;
 161   fp->parent = parent;
 162   fp->fn = fn;
 163   fp->FsmTimer.name = timer_names[0];
 164   fp->OpenTimer.name = timer_names[1];
 165   fp->StoppedTimer.name = timer_names[2];
 166 }
 167
 168 static void
 169 NewState(struct fsm *fp, int new)
 170 {
 171   log_Printf(fp->LogLevel, "%s: State change %s --> %s\n",
 172              fp->link->name, State2Nam(fp->state), State2Nam(new));
 173   if (fp->state == ST_STOPPED && fp->StoppedTimer.state == TIMER_RUNNING)
 174     timer_Stop(&fp->StoppedTimer);
 175   fp->state = new;
 176   if ((new >= ST_INITIAL && new <= ST_STOPPED) || (new == ST_OPENED)) {
 177     timer_Stop(&fp->FsmTimer);
 178     if (new == ST_STOPPED && fp->StoppedTimer.load) {
 179       timer_Stop(&fp->StoppedTimer);
 180       fp->StoppedTimer.func = StoppedTimeout;
 181       fp->StoppedTimer.arg = (void *) fp;
 182       timer_Start(&fp->StoppedTimer);
 183     }
 184   }
 185 }
 186
 187 void
 188 fsm_Output(struct fsm *fp, u_int code, u_int id, u_char *ptr, unsigned count,
 189            int mtype)
 190 {
 191   int plen;
 192   struct fsmheader lh;
 193   struct mbuf *bp;
 194
 195   if (log_IsKept(fp->LogLevel)) {
 196     log_Printf(fp->LogLevel, "%s: Send%s(%d) state = %s\n",
 197               fp->link->name, Code2Nam(code), id, State2Nam(fp->state));
 198     switch (code) {
 199       case CODE_CONFIGREQ:
 200       case CODE_CONFIGACK:
 201       case CODE_CONFIGREJ:
 202       case CODE_CONFIGNAK:
 203         (*fp->fn->DecodeConfig)(fp, ptr, ptr + count, MODE_NOP, NULL);
 204         if (count < sizeof(struct fsm_opt_hdr))
 205           log_Printf(fp->LogLevel, "  [EMPTY]\n");
 206         break;
 207     }
 208   }
 209
 210   plen = sizeof(struct fsmheader) + count;
 211   lh.code = code;
 212   lh.id = id;
 213   lh.length = htons(plen);
 214   bp = m_get(plen, mtype);
 215   memcpy(MBUF_CTOP(bp), &lh, sizeof(struct fsmheader));
 216   if (count)
 217     memcpy(MBUF_CTOP(bp) + sizeof(struct fsmheader), ptr, count);
 218   log_DumpBp(LogDEBUG, "fsm_Output", bp);
 219   link_PushPacket(fp->link, bp, fp->bundle, LINK_QUEUES(fp->link) - 1,
 220                   fp->proto);
 221
 222   if (code == CODE_CONFIGREJ)
 223     lcp_SendIdentification(&fp->link->lcp);
 224 }
 225
 226 static void
 227 FsmOpenNow(void *v)
 228 {
 229   struct fsm *fp = (struct fsm *)v;
 230
 231   timer_Stop(&fp->OpenTimer);
 232   if (fp->state <= ST_STOPPED) {
 233     if (fp->state != ST_STARTING) {
 234       /*
 235        * In practice, we're only here in ST_STOPPED (when delaying the
 236        * first config request) or ST_CLOSED (when openmode == 0).
 237        *
 238        * The ST_STOPPED bit is breaking the RFC already :-(
 239        *
 240        * According to the RFC (1661) state transition table, a TLS isn't
 241        * required for an Open event when state == Closed, but the RFC
 242        * must be wrong as TLS hasn't yet been called (since the last TLF)
 243        * ie, Initial gets an `Up' event, Closing gets a RTA etc.
 244        */
 245       (*fp->fn->LayerStart)(fp);
 246       (*fp->parent->LayerStart)(fp->parent->object, fp);
 247     }
 248     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 249     FsmSendConfigReq(fp);
 250     NewState(fp, ST_REQSENT);
 251   }
 252 }
 253
 254 void
 255 fsm_Open(struct fsm *fp)
 256 {
 257   switch (fp->state) {
 258   case ST_INITIAL:
 259     NewState(fp, ST_STARTING);
 260     (*fp->fn->LayerStart)(fp);
 261     (*fp->parent->LayerStart)(fp->parent->object, fp);
 262     break;
 263   case ST_CLOSED:
 264     if (fp->open_mode == OPEN_PASSIVE) {
 265       NewState(fp, ST_STOPPED);         /* XXX: This is a hack ! */
 266     } else if (fp->open_mode > 0) {
 267       if (fp->open_mode > 1)
 268         log_Printf(LogPHASE, "%s: Entering STOPPED state for %d seconds\n",
 269                   fp->link->name, fp->open_mode);
 270       NewState(fp, ST_STOPPED);         /* XXX: This is a not-so-bad hack ! */
 271       timer_Stop(&fp->OpenTimer);
 272       fp->OpenTimer.load = fp->open_mode * SECTICKS;
 273       fp->OpenTimer.func = FsmOpenNow;
 274       fp->OpenTimer.arg = (void *)fp;
 275       timer_Start(&fp->OpenTimer);
 276     } else
 277       FsmOpenNow(fp);
 278     break;
 279   case ST_STOPPED:              /* XXX: restart option */
 280   case ST_REQSENT:
 281   case ST_ACKRCVD:
 282   case ST_ACKSENT:
 283   case ST_OPENED:               /* XXX: restart option */
 284     break;
 285   case ST_CLOSING:              /* XXX: restart option */
 286   case ST_STOPPING:             /* XXX: restart option */
 287     NewState(fp, ST_STOPPING);
 288     break;
 289   }
 290 }
 291
 292 void
 293 fsm_Up(struct fsm *fp)
 294 {
 295   switch (fp->state) {
 296   case ST_INITIAL:
 297     log_Printf(fp->LogLevel, "FSM: Using \"%s\" as a transport\n",
 298               fp->link->name);
 299     NewState(fp, ST_CLOSED);
 300     break;
 301   case ST_STARTING:
 302     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 303     FsmSendConfigReq(fp);
 304     NewState(fp, ST_REQSENT);
 305     break;
 306   default:
 307     log_Printf(fp->LogLevel, "%s: Oops, Up at %s\n",
 308               fp->link->name, State2Nam(fp->state));
 309     break;
 310   }
 311 }
 312
 313 void
 314 fsm_Down(struct fsm *fp)
 315 {
 316   switch (fp->state) {
 317   case ST_CLOSED:
 318     NewState(fp, ST_INITIAL);
 319     break;
 320   case ST_CLOSING:
 321     /* This TLF contradicts the RFC (1661), which ``misses it out'' ! */
 322     (*fp->fn->LayerFinish)(fp);
 323     NewState(fp, ST_INITIAL);
 324     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 325     break;
 326   case ST_STOPPED:
 327     NewState(fp, ST_STARTING);
 328     (*fp->fn->LayerStart)(fp);
 329     (*fp->parent->LayerStart)(fp->parent->object, fp);
 330     break;
 331   case ST_STOPPING:
 332   case ST_REQSENT:
 333   case ST_ACKRCVD:
 334   case ST_ACKSENT:
 335     NewState(fp, ST_STARTING);
 336     break;
 337   case ST_OPENED:
 338     (*fp->fn->LayerDown)(fp);
 339     NewState(fp, ST_STARTING);
 340     (*fp->parent->LayerDown)(fp->parent->object, fp);
 341     break;
 342   }
 343 }
 344
 345 void
 346 fsm_Close(struct fsm *fp)
 347 {
 348   switch (fp->state) {
 349   case ST_STARTING:
 350     (*fp->fn->LayerFinish)(fp);
 351     NewState(fp, ST_INITIAL);
 352     (*fp->parent->LayerFinish)(fp->parent->object, fp);
 353     break;
 354   case ST_STOPPED:
 355     NewState(fp, ST_CLOSED);
 356     break;
 357   case ST_STOPPING:
 358     NewState(fp, ST_CLOSING);
 359     break;
 360   case ST_OPENED:
 361     (*fp->fn->LayerDown)(fp);
 362     if (fp->state == ST_OPENED) {
 363       FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 364       FsmSendTerminateReq(fp);
 365       NewState(fp, ST_CLOSING);
 366       (*fp->parent->LayerDown)(fp->parent->object, fp);
 367     }
 368     break;
 369   case ST_REQSENT:
 370   case ST_ACKRCVD:
 371   case ST_ACKSENT:
 372     FsmInitRestartCounter(fp, FSM_TRM_TIMER);
 373     FsmSendTerminateReq(fp);
 374     NewState(fp, ST_CLOSING);
 375     break;
 376   }
 377 }
 378
 379 /*
 380  *      Send functions
 381  */
 382 static void
 383 FsmSendConfigReq(struct fsm *fp)
 384 {
 385   if (fp->more.reqs-- > 0 && fp->restart-- > 0) {
 386     (*fp->fn->SendConfigReq)(fp);
 387     timer_Start(&fp->FsmTimer);         /* Start restart timer */
 388   } else {
 389     if (fp->more.reqs < 0)
 390       log_Printf(LogPHASE, "%s: Too many %s REQs sent - abandoning "
 391                  "negotiation\n", fp->link->name, fp->name);
 392     lcp_SendIdentification(&fp->link->lcp);
 393     fsm_Close(fp);
 394   }
 395 }
 396
 397 static void
 398 FsmSendTerminateReq(struct fsm *fp)
 399 {
 400   fsm_Output(fp, CODE_TERMREQ, fp->reqid, NULL, 0, MB_UNKNOWN);
 401   (*fp->fn->SentTerminateReq)(fp);
 402   timer_Start(&fp->FsmTimer);   /* Start restart timer */
 403   fp->restart--;                /* Decrement restart counter */
 404 }
 405
 406 /*
 407  *      Timeout actions
 408  */
 409 static void
 410 FsmTimeout(void *v)
 411 {
 412   struct fsm *fp = (struct fsm *)v;
 413
 414   if (fp->restart) {
 415     switch (fp->state) {
 416     case ST_CLOSING:
 417     case ST_STOPPING:
 418       FsmSendTerminateReq(fp);
 419       break;
 420     case ST_REQSENT:
 421     case ST_ACKSENT:
 422       FsmSendConfigReq(fp);
 423       break;
 424     case ST_ACKRCVD:
 425       FsmSendConfigReq(fp);
 426       NewState(fp, ST_REQSENT);
 427       break;
 428     }
 429     timer_Start(&fp->FsmTimer);
 430   } else {
 431     switch (fp->state) {
 432     case ST_CLOSING:
 433       (*fp->fn->LayerFinish)(fp);
 434       NewState(fp, ST_CLOSED);
 435       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 436       break;
 437     case ST_STOPPING:
 438       (*fp->fn->LayerFinish)(fp);
 439       NewState(fp, ST_STOPPED);
 440       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 441       break;
 442     case ST_REQSENT:            /* XXX: 3p */
 443     case ST_ACKSENT:
 444     case ST_ACKRCVD:
 445       (*fp->fn->LayerFinish)(fp);
 446       NewState(fp, ST_STOPPED);
 447       (*fp->parent->LayerFinish)(fp->parent->object, fp);
 448       break;
 449     }
 450   }
 451 }
 452
 453 static void
 454 FsmInitRestartCounter(struct fsm *fp, int what)
 455 {
 456   timer_Stop(&fp->FsmTimer);
 457   fp->FsmTimer.func = FsmTimeout;
 458   fp->FsmTimer.arg = (void *)fp;
 459   (*fp->fn->InitRestartCounter)(fp, what);
 460 }
 461
 462 /*
 463  * Actions when receive packets
 464  */
 465 static void
 466 FsmRecvConfigReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 467 /* RCR */
 468 {
 469   struct fsm_decode dec;
 470   int plen, flen;
 471   int ackaction = 0;
 472   u_char *cp;
 473
 474   bp = m_pullup(bp);
 475   plen = m_length(bp);
 476   flen = ntohs(lhp->length) - sizeof *lhp;
 477   if (plen < flen) {
 478     log_Printf(LogWARN, "%s: FsmRecvConfigReq: plen (%d) < flen (%d)\n",
 479                fp->link->name, plen, flen);
 480     m_freem(bp);
 481     return;
 482   }
 483
 484   /* Some things must be done before we Decode the packet */
 485   switch (fp->state) {
 486   case ST_OPENED:
 487     (*fp->fn->LayerDown)(fp);
 488   }
 489
 490   dec.ackend = dec.ack;
 491   dec.nakend = dec.nak;
 492   dec.rejend = dec.rej;
 493   cp = MBUF_CTOP(bp);
 494   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_REQ, &dec);
 495   if (flen < (int)sizeof(struct fsm_opt_hdr))
 496     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 497
 498   if (dec.nakend == dec.nak && dec.rejend == dec.rej)
 499     ackaction = 1;
 500
 501   /* Check and process easy case */
 502   switch (fp->state) {
 503   case ST_INITIAL:
 504     if (fp->proto == PROTO_CCP && fp->link->lcp.fsm.state == ST_OPENED) {
 505       /*
 506        * ccp_SetOpenMode() leaves us in initial if we're disabling
 507        * & denying everything.
 508        */
 509       bp = m_prepend(bp, lhp, sizeof *lhp, 2);
 510       bp = proto_Prepend(bp, fp->proto, 0, 0);
 511       bp = m_pullup(bp);
 512       lcp_SendProtoRej(&fp->link->lcp, MBUF_CTOP(bp), bp->m_len);
 513       m_freem(bp);
 514       return;
 515     }
 516     /* FALLTHROUGH */
 517   case ST_STARTING:
 518     log_Printf(fp->LogLevel, "%s: Oops, RCR in %s.\n",
 519               fp->link->name, State2Nam(fp->state));
 520     m_freem(bp);
 521     return;
 522   case ST_CLOSED:
 523     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 524     m_freem(bp);
 525     return;
 526   case ST_CLOSING:
 527     log_Printf(fp->LogLevel, "%s: Error: Got ConfigReq while state = %s\n",
 528               fp->link->name, State2Nam(fp->state));
 529     /* FALLTHROUGH */
 530   case ST_STOPPING:
 531     m_freem(bp);
 532     return;
 533   case ST_STOPPED:
 534     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 535     /* FALLTHROUGH */
 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 < (int)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 < (int)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 __unused, 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   size_t plen;
 808   int flen;
 809   u_char *cp;
 810
 811   plen = m_length(bp);
 812   flen = ntohs(lhp->length) - sizeof *lhp;
 813   if ((int)plen < flen) {
 814     m_freem(bp);
 815     return;
 816   }
 817
 818   lcp_SendIdentification(&fp->link->lcp);
 819
 820   /*
 821    * Check and process easy case
 822    */
 823   switch (fp->state) {
 824   case ST_INITIAL:
 825   case ST_STARTING:
 826     log_Printf(fp->LogLevel, "%s: Oops, RCJ in %s.\n",
 827               fp->link->name, State2Nam(fp->state));
 828     m_freem(bp);
 829     return;
 830   case ST_CLOSED:
 831   case ST_STOPPED:
 832     (*fp->fn->SendTerminateAck)(fp, lhp->id);
 833     m_freem(bp);
 834     return;
 835   case ST_CLOSING:
 836   case ST_STOPPING:
 837     m_freem(bp);
 838     return;
 839   }
 840
 841   bp = m_pullup(bp);
 842   dec.ackend = dec.ack;
 843   dec.nakend = dec.nak;
 844   dec.rejend = dec.rej;
 845   cp = MBUF_CTOP(bp);
 846   (*fp->fn->DecodeConfig)(fp, cp, cp + flen, MODE_REJ, &dec);
 847   if (flen < (int)sizeof(struct fsm_opt_hdr))
 848     log_Printf(fp->LogLevel, "  [EMPTY]\n");
 849
 850   switch (fp->state) {
 851   case ST_REQSENT:
 852   case ST_ACKSENT:
 853     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
 854     FsmSendConfigReq(fp);
 855     break;
 856   case ST_OPENED:
 857     (*fp->fn->LayerDown)(fp);
 858     FsmSendConfigReq(fp);
 859     NewState(fp, ST_REQSENT);
 860     (*fp->parent->LayerDown)(fp->parent->object, fp);
 861     break;
 862   case ST_ACKRCVD:
 863     FsmSendConfigReq(fp);
 864     NewState(fp, ST_REQSENT);
 865     break;
 866   }
 867   m_freem(bp);
 868 }
 869
 870 static void
 871 FsmRecvCodeRej(struct fsm *fp __unused, struct fsmheader *lhp __unused,
 872                struct mbuf *bp)
 873 {
 874   m_freem(bp);
 875 }
 876
 877 static void
 878 FsmRecvProtoRej(struct fsm *fp, struct fsmheader *lhp __unused, struct mbuf *bp)
 879 {
 880   struct physical *p = link2physical(fp->link);
 881   u_short proto;
 882
 883   if (m_length(bp) < 2) {
 884     m_freem(bp);
 885     return;
 886   }
 887   bp = mbuf_Read(bp, &proto, 2);
 888   proto = ntohs(proto);
 889   log_Printf(fp->LogLevel, "%s: -- Protocol 0x%04x (%s) was rejected!\n",
 890             fp->link->name, proto, hdlc_Protocol2Nam(proto));
 891
 892   switch (proto) {
 893   case PROTO_LQR:
 894     if (p)
 895       lqr_Stop(p, LQM_LQR);
 896     else
 897       log_Printf(LogERROR, "%s: FsmRecvProtoRej: Not a physical link !\n",
 898                 fp->link->name);
 899     break;
 900   case PROTO_CCP:
 901     if (fp->proto == PROTO_LCP) {
 902       fp = &fp->link->ccp.fsm;
 903       /* Despite the RFC (1661), don't do an out-of-place TLF */
 904       /* (*fp->fn->LayerFinish)(fp); */
 905       switch (fp->state) {
 906       case ST_CLOSED:
 907       case ST_CLOSING:
 908         NewState(fp, ST_CLOSED);
 909         break;
 910       default:
 911         NewState(fp, ST_STOPPED);
 912         break;
 913       }
 914       /* See above */
 915       /* (*fp->parent->LayerFinish)(fp->parent->object, fp); */
 916     }
 917     break;
 918   case PROTO_IPCP:
 919     if (fp->proto == PROTO_LCP) {
 920       log_Printf(LogPHASE, "%s: IPCP protocol reject closes IPCP !\n",
 921                 fp->link->name);
 922       fsm_Close(&fp->bundle->ncp.ipcp.fsm);
 923     }
 924     break;
 925 #ifndef NOINET6
 926   case PROTO_IPV6CP:
 927     if (fp->proto == PROTO_LCP) {
 928       log_Printf(LogPHASE, "%s: IPV6CP protocol reject closes IPV6CP !\n",
 929                 fp->link->name);
 930       fsm_Close(&fp->bundle->ncp.ipv6cp.fsm);
 931     }
 932     break;
 933 #endif
 934   case PROTO_MP:
 935     if (fp->proto == PROTO_LCP) {
 936       struct lcp *lcp = fsm2lcp(fp);
 937
 938       if (lcp->want_mrru && lcp->his_mrru) {
 939         log_Printf(LogPHASE, "%s: MP protocol reject is fatal !\n",
 940                   fp->link->name);
 941         fsm_Close(fp);
 942       }
 943     }
 944     break;
 945   }
 946   m_freem(bp);
 947 }
 948
 949 static void
 950 FsmRecvEchoReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 951 {
 952   struct lcp *lcp = fsm2lcp(fp);
 953   u_char *cp;
 954   u_int32_t magic;
 955
 956   bp = m_pullup(bp);
 957   m_settype(bp, MB_ECHOIN);
 958
 959   if (lcp && ntohs(lhp->length) - sizeof *lhp >= 4) {
 960     cp = MBUF_CTOP(bp);
 961     ua_ntohl(cp, &magic);
 962     if (magic != lcp->his_magic) {
 963       log_Printf(fp->LogLevel, "%s: RecvEchoReq: magic 0x%08lx is wrong,"
 964                  " expecting 0x%08lx\n", fp->link->name, (u_long)magic,
 965                  (u_long)lcp->his_magic);
 966       /* XXX: We should send terminate request */
 967     }
 968     if (fp->state == ST_OPENED) {
 969       ua_htonl(&lcp->want_magic, cp);           /* local magic */
 970       fsm_Output(fp, CODE_ECHOREP, lhp->id, cp,
 971                  ntohs(lhp->length) - sizeof *lhp, MB_ECHOOUT);
 972     }
 973   }
 974   m_freem(bp);
 975 }
 976
 977 static void
 978 FsmRecvEchoRep(struct fsm *fp, struct fsmheader *lhp __unused, struct mbuf *bp)
 979 {
 980   if (fsm2lcp(fp))
 981     bp = lqr_RecvEcho(fp, bp);
 982
 983   m_freem(bp);
 984 }
 985
 986 static void
 987 FsmRecvDiscReq(struct fsm *fp __unused, struct fsmheader *lhp __unused,
 988                struct mbuf *bp)
 989 {
 990   m_freem(bp);
 991 }
 992
 993 static void
 994 FsmRecvIdent(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
 995 {
 996   u_int32_t magic;
 997   u_short len;
 998   u_char *cp;
 999
1000   len = ntohs(lhp->length) - sizeof *lhp;
1001   if (len >= 4) {
1002     bp = m_pullup(m_append(bp, "", 1));
1003     cp = MBUF_CTOP(bp);
1004     ua_ntohl(cp, &magic);
1005     if (magic != fp->link->lcp.his_magic)
1006       log_Printf(fp->LogLevel, "%s: RecvIdent: magic 0x%08lx is wrong,"
1007                  " expecting 0x%08lx\n", fp->link->name, (u_long)magic,
1008                  (u_long)fp->link->lcp.his_magic);
1009     cp[len] = '\0';
1010     lcp_RecvIdentification(&fp->link->lcp, cp + 4);
1011   }
1012   m_freem(bp);
1013 }
1014
1015 static void
1016 FsmRecvTimeRemain(struct fsm *fp __unused, struct fsmheader *lhp __unused,
1017                   struct mbuf *bp)
1018 {
1019   m_freem(bp);
1020 }
1021
1022 static void
1023 FsmRecvResetReq(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
1024 {
1025   if ((*fp->fn->RecvResetReq)(fp)) {
1026     /*
1027      * All sendable compressed packets are queued in the first (lowest
1028      * priority) modem output queue.... dump 'em to the priority queue
1029      * so that they arrive at the peer before our ResetAck.
1030      */
1031     link_SequenceQueue(fp->link);
1032     fsm_Output(fp, CODE_RESETACK, lhp->id, NULL, 0, MB_CCPOUT);
1033   }
1034   m_freem(bp);
1035 }
1036
1037 static void
1038 FsmRecvResetAck(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
1039 {
1040   (*fp->fn->RecvResetAck)(fp, lhp->id);
1041   m_freem(bp);
1042 }
1043
1044 void
1045 fsm_Input(struct fsm *fp, struct mbuf *bp)
1046 {
1047   size_t len;
1048   struct fsmheader lh;
1049   const struct fsmcodedesc *codep;
1050
1051   len = m_length(bp);
1052   if (len < sizeof(struct fsmheader)) {
1053     m_freem(bp);
1054     return;
1055   }
1056   bp = mbuf_Read(bp, &lh, sizeof lh);
1057
1058   if (ntohs(lh.length) > len) {
1059     log_Printf(LogWARN, "%s: Oops: Got %zu bytes but %d byte payload "
1060                "- dropped\n", fp->link->name, len, (int)ntohs(lh.length));
1061     m_freem(bp);
1062     return;
1063   }
1064
1065   if (lh.code < fp->min_code || lh.code > fp->max_code ||
1066       lh.code > NELEM(FsmCodes)) {
1067     /*
1068      * Use a private id.  This is really a response-type packet, but we
1069      * MUST send a unique id for each REQ....
1070      */
1071     static u_char id;
1072
1073     bp = m_prepend(bp, &lh, sizeof lh, 0);
1074     bp = m_pullup(bp);
1075     fsm_Output(fp, CODE_CODEREJ, id++, MBUF_CTOP(bp), bp->m_len, MB_UNKNOWN);
1076     m_freem(bp);
1077     return;
1078   }
1079
1080   codep = FsmCodes + lh.code - 1;
1081   if (lh.id != fp->reqid && codep->check_reqid &&
1082       Enabled(fp->bundle, OPT_IDCHECK)) {
1083     log_Printf(fp->LogLevel, "%s: Recv%s(%d), dropped (expected %d)\n",
1084                fp->link->name, codep->name, lh.id, fp->reqid);
1085     return;
1086   }
1087
1088   log_Printf(fp->LogLevel, "%s: Recv%s(%d) state = %s\n",
1089              fp->link->name, codep->name, lh.id, State2Nam(fp->state));
1090
1091   if (codep->inc_reqid && (lh.id == fp->reqid ||
1092       (!Enabled(fp->bundle, OPT_IDCHECK) && codep->check_reqid)))
1093     fp->reqid++;        /* That's the end of that ``exchange''.... */
1094
1095   (*codep->recv)(fp, &lh, bp);
1096 }
1097
1098 int
1099 fsm_NullRecvResetReq(struct fsm *fp)
1100 {
1101   log_Printf(fp->LogLevel, "%s: Oops - received unexpected reset req\n",
1102             fp->link->name);
1103   return 1;
1104 }
1105
1106 void
1107 fsm_NullRecvResetAck(struct fsm *fp, u_char id __unused)
1108 {
1109   log_Printf(fp->LogLevel, "%s: Oops - received unexpected reset ack\n",
1110             fp->link->name);
1111 }
1112
1113 void
1114 fsm_Reopen(struct fsm *fp)
1115 {
1116   if (fp->state == ST_OPENED) {
1117     (*fp->fn->LayerDown)(fp);
1118     FsmInitRestartCounter(fp, FSM_REQ_TIMER);
1119     FsmSendConfigReq(fp);
1120     NewState(fp, ST_REQSENT);
1121     (*fp->parent->LayerDown)(fp->parent->object, fp);
1122   }
1123 }
1124
1125 void
1126 fsm2initial(struct fsm *fp)
1127 {
1128   timer_Stop(&fp->FsmTimer);
1129   timer_Stop(&fp->OpenTimer);
1130   timer_Stop(&fp->StoppedTimer);
1131   if (fp->state == ST_STOPPED)
1132     fsm_Close(fp);
1133   if (fp->state > ST_INITIAL)
1134     fsm_Down(fp);
1135   if (fp->state > ST_INITIAL)
1136     fsm_Close(fp);
1137 }
1138
1139 struct fsm_opt *
1140 fsm_readopt(u_char **cp)
1141 {
1142   struct fsm_opt *o = (struct fsm_opt *)*cp;
1143
1144   if (o->hdr.len < sizeof(struct fsm_opt_hdr)) {
1145     log_Printf(LogERROR, "Bad option length %d (out of phase?)\n", o->hdr.len);
1146     return NULL;
1147   }
1148
1149   *cp += o->hdr.len;
1150
1151   if (o->hdr.len > sizeof(struct fsm_opt)) {
1152     log_Printf(LogERROR, "Warning: Truncating option length from %d to %d\n",
1153                o->hdr.len, (int)sizeof(struct fsm_opt));
1154     o->hdr.len = sizeof(struct fsm_opt);
1155   }
1156
1157   return o;
1158 }
1159
1160 static int
1161 fsm_opt(u_char *opt, int optlen, const struct fsm_opt *o)
1162 {
1163   unsigned cplen = o->hdr.len;
1164
1165   if (optlen < (int)sizeof(struct fsm_opt_hdr))
1166     optlen = 0;
1167
1168   if ((int)cplen > optlen) {
1169     log_Printf(LogERROR, "Can't REJ length %d - trunating to %d\n",
1170       cplen, optlen);
1171     cplen = optlen;
1172   }
1173   memcpy(opt, o, cplen);
1174   if (cplen)
1175     opt[1] = cplen;
1176
1177   return cplen;
1178 }
1179
1180 void
1181 fsm_rej(struct fsm_decode *dec, const struct fsm_opt *o)
1182 {
1183   if (!dec)
1184     return;
1185   dec->rejend += fsm_opt(dec->rejend, FSM_OPTLEN - (dec->rejend - dec->rej), o);
1186 }
1187
1188 void
1189 fsm_ack(struct fsm_decode *dec, const struct fsm_opt *o)
1190 {
1191   if (!dec)
1192     return;
1193   dec->ackend += fsm_opt(dec->ackend, FSM_OPTLEN - (dec->ackend - dec->ack), o);
1194 }
1195
1196 void
1197 fsm_nak(struct fsm_decode *dec, const struct fsm_opt *o)
1198 {
1199   if (!dec)
1200     return;
1201   dec->nakend += fsm_opt(dec->nakend, FSM_OPTLEN - (dec->nakend - dec->nak), o);
1202 }
1203
1204 void
1205 fsm_opt_normalise(struct fsm_decode *dec)
1206 {
1207   if (dec->rejend != dec->rej) {
1208     /* rejects are preferred */
1209     dec->ackend = dec->ack;
1210     dec->nakend = dec->nak;
1211   } else if (dec->nakend != dec->nak)
1212     /* then NAKs */
1213     dec->ackend = dec->ack;
1214 }