packages/net/lwip_tcpip/v2_0/src/netif/ppp/fsm.c

   1 /*****************************************************************************
   2 * fsm.c - Network Control Protocol Finite State Machine program file.
   3 *
   4 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
   5 * portions Copyright (c) 1997 by Global Election Systems Inc.
   6 *
   7 * The authors hereby grant permission to use, copy, modify, distribute,
   8 * and license this software and its documentation for any purpose, provided
   9 * that existing copyright notices are retained in all copies and that this
  10 * notice and the following disclaimer are included verbatim in any
  11 * distributions. No written agreement, license, or royalty fee is required
  12 * for any of the authorized uses.
  13 *
  14 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
  15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24 *
  25 ******************************************************************************
  26 * REVISION HISTORY
  27 *
  28 * 03-01-01 Marc Boucher <marc@mbsi.ca>
  29 *   Ported to lwIP.
  30 * 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
  31 *       Original based on BSD fsm.c.
  32 *****************************************************************************/
  33 /*
  34  * fsm.c - {Link, IP} Control Protocol Finite State Machine.
  35  *
  36  * Copyright (c) 1989 Carnegie Mellon University.
  37  * All rights reserved.
  38  *
  39  * Redistribution and use in source and binary forms are permitted
  40  * provided that the above copyright notice and this paragraph are
  41  * duplicated in all such forms and that any documentation,
  42  * advertising materials, and other materials related to such
  43  * distribution and use acknowledge that the software was developed
  44  * by Carnegie Mellon University.  The name of the
  45  * University may not be used to endorse or promote products derived
  46  * from this software without specific prior written permission.
  47  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  48  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  49  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  50  */
  51
  52
  53 /*
  54  * TODO:
  55  * Randomize fsm id on link/init.
  56  * Deal with variable outgoing MTU.
  57  */
  58
  59 #include "ppp.h"
  60 #if PPP_SUPPORT > 0
  61 #include "fsm.h"
  62 #include "pppdebug.h"
  63
  64
  65 /*************************/
  66 /*** LOCAL DEFINITIONS ***/
  67 /*************************/
  68
  69
  70 /************************/
  71 /*** LOCAL DATA TYPES ***/
  72 /************************/
  73
  74
  75 /***********************************/
  76 /*** LOCAL FUNCTION DECLARATIONS ***/
  77 /***********************************/
  78 static void fsm_timeout (void *);
  79 static void fsm_rconfreq (fsm *, u_char, u_char *, int);
  80 static void fsm_rconfack (fsm *, int, u_char *, int);
  81 static void fsm_rconfnakrej (fsm *, int, int, u_char *, int);
  82 static void fsm_rtermreq (fsm *, int, u_char *, int);
  83 static void fsm_rtermack (fsm *);
  84 static void fsm_rcoderej (fsm *, u_char *, int);
  85 static void fsm_sconfreq (fsm *, int);
  86
  87 #define PROTO_NAME(f)   ((f)->callbacks->proto_name)
  88
  89
  90 /******************************/
  91 /*** PUBLIC DATA STRUCTURES ***/
  92 /******************************/
  93
  94
  95 /*****************************/
  96 /*** LOCAL DATA STRUCTURES ***/
  97 /*****************************/
  98 int peer_mru[NUM_PPP];
  99
 100
 101 /***********************************/
 102 /*** PUBLIC FUNCTION DEFINITIONS ***/
 103 /***********************************/
 104
 105 /*
 106  * fsm_init - Initialize fsm.
 107  *
 108  * Initialize fsm state.
 109  */
 110 void fsm_init(fsm *f)
 111 {
 112         f->state = INITIAL;
 113         f->flags = 0;
 114         f->id = 0;                              /* XXX Start with random id? */
 115         f->timeouttime = FSM_DEFTIMEOUT;
 116         f->maxconfreqtransmits = FSM_DEFMAXCONFREQS;
 117         f->maxtermtransmits = FSM_DEFMAXTERMREQS;
 118         f->maxnakloops = FSM_DEFMAXNAKLOOPS;
 119         f->term_reason_len = 0;
 120 }
 121
 122
 123 /*
 124  * fsm_lowerup - The lower layer is up.
 125  */
 126 void fsm_lowerup(fsm *f)
 127 {
 128         int oldState = f->state;
 129
 130         switch( f->state ){
 131         case INITIAL:
 132                 f->state = CLOSED;
 133                 break;
 134
 135         case STARTING:
 136                 if( f->flags & OPT_SILENT )
 137                         f->state = STOPPED;
 138                 else {
 139                         /* Send an initial configure-request */
 140                         fsm_sconfreq(f, 0);
 141                         f->state = REQSENT;
 142                 }
 143         break;
 144
 145         default:
 146                 FSMDEBUG((LOG_INFO, "%s: Up event in state %d!\n",
 147                                 PROTO_NAME(f), f->state));
 148         }
 149
 150         FSMDEBUG((LOG_INFO, "%s: lowerup state %d -> %d\n",
 151                         PROTO_NAME(f), oldState, f->state));
 152 }
 153
 154
 155 /*
 156  * fsm_lowerdown - The lower layer is down.
 157  *
 158  * Cancel all timeouts and inform upper layers.
 159  */
 160 void fsm_lowerdown(fsm *f)
 161 {
 162         int oldState = f->state;
 163
 164         switch( f->state ){
 165         case CLOSED:
 166                 f->state = INITIAL;
 167                 break;
 168
 169         case STOPPED:
 170                 f->state = STARTING;
 171                 if( f->callbacks->starting )
 172                         (*f->callbacks->starting)(f);
 173                 break;
 174
 175         case CLOSING:
 176                 f->state = INITIAL;
 177                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 178                 break;
 179
 180         case STOPPING:
 181         case REQSENT:
 182         case ACKRCVD:
 183         case ACKSENT:
 184                 f->state = STARTING;
 185                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 186                 break;
 187
 188         case OPENED:
 189                 if( f->callbacks->down )
 190                         (*f->callbacks->down)(f);
 191                 f->state = STARTING;
 192                 break;
 193
 194         default:
 195                 FSMDEBUG((LOG_INFO, "%s: Down event in state %d!\n",
 196                                 PROTO_NAME(f), f->state));
 197         }
 198
 199         FSMDEBUG((LOG_INFO, "%s: lowerdown state %d -> %d\n",
 200                         PROTO_NAME(f), oldState, f->state));
 201 }
 202
 203
 204 /*
 205  * fsm_open - Link is allowed to come up.
 206  */
 207 void fsm_open(fsm *f)
 208 {
 209         int oldState = f->state;
 210
 211         switch( f->state ){
 212                 case INITIAL:
 213                         f->state = STARTING;
 214                         if( f->callbacks->starting )
 215                                 (*f->callbacks->starting)(f);
 216                         break;
 217
 218                 case CLOSED:
 219                 if( f->flags & OPT_SILENT )
 220                         f->state = STOPPED;
 221                 else {
 222                         /* Send an initial configure-request */
 223                         fsm_sconfreq(f, 0);
 224                         f->state = REQSENT;
 225                 }
 226                 break;
 227
 228         case CLOSING:
 229                 f->state = STOPPING;
 230                 /* fall through */
 231         case STOPPED:
 232         case OPENED:
 233                 if( f->flags & OPT_RESTART ){
 234                         fsm_lowerdown(f);
 235                         fsm_lowerup(f);
 236                 }
 237                 break;
 238         }
 239
 240         FSMDEBUG((LOG_INFO, "%s: open state %d -> %d\n",
 241                         PROTO_NAME(f), oldState, f->state));
 242 }
 243
 244
 245 /*
 246  * fsm_close - Start closing connection.
 247  *
 248  * Cancel timeouts and either initiate close or possibly go directly to
 249  * the CLOSED state.
 250  */
 251 void fsm_close(fsm *f, char *reason)
 252 {
 253         int oldState = f->state;
 254
 255         f->term_reason = reason;
 256         f->term_reason_len = (reason == NULL? 0: strlen(reason));
 257         switch( f->state ){
 258         case STARTING:
 259                 f->state = INITIAL;
 260                 break;
 261         case STOPPED:
 262                 f->state = CLOSED;
 263                 break;
 264         case STOPPING:
 265                 f->state = CLOSING;
 266                 break;
 267
 268         case REQSENT:
 269         case ACKRCVD:
 270         case ACKSENT:
 271         case OPENED:
 272                 if( f->state != OPENED )
 273                         UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 274                 else if( f->callbacks->down )
 275                         (*f->callbacks->down)(f);       /* Inform upper layers we're down */
 276
 277                 /* Init restart counter, send Terminate-Request */
 278                 f->retransmits = f->maxtermtransmits;
 279                 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
 280                                         (u_char *) f->term_reason, f->term_reason_len);
 281                 TIMEOUT(fsm_timeout, f, f->timeouttime);
 282                 --f->retransmits;
 283
 284                 f->state = CLOSING;
 285                 break;
 286         }
 287
 288         FSMDEBUG((LOG_INFO, "%s: close reason=%s state %d -> %d\n",
 289                         PROTO_NAME(f), reason, oldState, f->state));
 290 }
 291
 292
 293 /*
 294  * fsm_sdata - Send some data.
 295  *
 296  * Used for all packets sent to our peer by this module.
 297  */
 298 void fsm_sdata(
 299         fsm *f,
 300         u_char code,
 301         u_char id,
 302         u_char *data,
 303         int datalen
 304 )
 305 {
 306         u_char *outp;
 307         int outlen;
 308
 309         /* Adjust length to be smaller than MTU */
 310         outp = outpacket_buf[f->unit];
 311         if (datalen > peer_mru[f->unit] - (int)HEADERLEN)
 312                 datalen = peer_mru[f->unit] - HEADERLEN;
 313         if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
 314                 BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
 315         outlen = datalen + HEADERLEN;
 316         MAKEHEADER(outp, f->protocol);
 317         PUTCHAR(code, outp);
 318         PUTCHAR(id, outp);
 319         PUTSHORT(outlen, outp);
 320         pppWrite(f->unit, outpacket_buf[f->unit], outlen + PPP_HDRLEN);
 321         FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d,%d,%d.\n",
 322                                 PROTO_NAME(f), code, id, outlen));
 323 }
 324
 325
 326 /*
 327  * fsm_input - Input packet.
 328  */
 329 void fsm_input(fsm *f, u_char *inpacket, int l)
 330 {
 331         u_char *inp = inpacket;
 332         u_char code, id;
 333         int len;
 334
 335         /*
 336         * Parse header (code, id and length).
 337         * If packet too short, drop it.
 338         */
 339         if (l < HEADERLEN) {
 340                 FSMDEBUG((LOG_WARNING, "fsm_input(%x): Rcvd short header.\n",
 341                                         f->protocol));
 342                 return;
 343         }
 344         GETCHAR(code, inp);
 345         GETCHAR(id, inp);
 346         GETSHORT(len, inp);
 347         if (len < HEADERLEN) {
 348                 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd illegal length.\n",
 349                                 f->protocol));
 350                 return;
 351         }
 352         if (len > l) {
 353                 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd short packet.\n",
 354                                 f->protocol));
 355                 return;
 356         }
 357         len -= HEADERLEN;               /* subtract header length */
 358
 359         if( f->state == INITIAL || f->state == STARTING ){
 360                 FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd packet in state %d.\n",
 361                                 f->protocol, f->state));
 362                 return;
 363         }
 364         FSMDEBUG((LOG_INFO, "fsm_input(%s):%d,%d,%d\n", PROTO_NAME(f), code, id, l));
 365         /*
 366          * Action depends on code.
 367          */
 368         switch (code) {
 369         case CONFREQ:
 370                 fsm_rconfreq(f, id, inp, len);
 371                 break;
 372
 373         case CONFACK:
 374                 fsm_rconfack(f, id, inp, len);
 375                 break;
 376
 377         case CONFNAK:
 378         case CONFREJ:
 379                 fsm_rconfnakrej(f, code, id, inp, len);
 380                 break;
 381
 382         case TERMREQ:
 383                 fsm_rtermreq(f, id, inp, len);
 384                 break;
 385
 386         case TERMACK:
 387                 fsm_rtermack(f);
 388                 break;
 389
 390         case CODEREJ:
 391                 fsm_rcoderej(f, inp, len);
 392                 break;
 393
 394         default:
 395                 if( !f->callbacks->extcode
 396                                 || !(*f->callbacks->extcode)(f, code, id, inp, len) )
 397                         fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
 398                 break;
 399         }
 400 }
 401
 402
 403 /*
 404  * fsm_protreject - Peer doesn't speak this protocol.
 405  *
 406  * Treat this as a catastrophic error (RXJ-).
 407  */
 408 void fsm_protreject(fsm *f)
 409 {
 410         switch( f->state ){
 411         case CLOSING:
 412                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 413                 /* fall through */
 414         case CLOSED:
 415                 f->state = CLOSED;
 416                 if( f->callbacks->finished )
 417                         (*f->callbacks->finished)(f);
 418                 break;
 419
 420         case STOPPING:
 421         case REQSENT:
 422         case ACKRCVD:
 423         case ACKSENT:
 424                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 425                 /* fall through */
 426         case STOPPED:
 427                 f->state = STOPPED;
 428                 if( f->callbacks->finished )
 429                         (*f->callbacks->finished)(f);
 430                 break;
 431
 432         case OPENED:
 433                 if( f->callbacks->down )
 434                         (*f->callbacks->down)(f);
 435
 436                 /* Init restart counter, send Terminate-Request */
 437                 f->retransmits = f->maxtermtransmits;
 438                 fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
 439                                         (u_char *) f->term_reason, f->term_reason_len);
 440                 TIMEOUT(fsm_timeout, f, f->timeouttime);
 441                 --f->retransmits;
 442
 443                 f->state = STOPPING;
 444                 break;
 445
 446         default:
 447                 FSMDEBUG((LOG_INFO, "%s: Protocol-reject event in state %d!\n",
 448                                         PROTO_NAME(f), f->state));
 449         }
 450 }
 451
 452
 453
 454
 455
 456 /**********************************/
 457 /*** LOCAL FUNCTION DEFINITIONS ***/
 458 /**********************************/
 459
 460 /*
 461  * fsm_timeout - Timeout expired.
 462  */
 463 static void fsm_timeout(void *arg)
 464 {
 465     fsm *f = (fsm *) arg;
 466
 467     switch (f->state) {
 468     case CLOSING:
 469     case STOPPING:
 470                 if( f->retransmits <= 0 ){
 471                     FSMDEBUG((LOG_WARNING, "%s: timeout sending Terminate-Request state=%d\n",
 472                                            PROTO_NAME(f), f->state));
 473                     /*
 474                      * We've waited for an ack long enough.  Peer probably heard us.
 475                      */
 476                     f->state = (f->state == CLOSING)? CLOSED: STOPPED;
 477                     if( f->callbacks->finished )
 478                         (*f->callbacks->finished)(f);
 479                 } else {
 480                     FSMDEBUG((LOG_WARNING, "%s: timeout resending Terminate-Requests state=%d\n",
 481                                            PROTO_NAME(f), f->state));
 482                     /* Send Terminate-Request */
 483                     fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
 484                               (u_char *) f->term_reason, f->term_reason_len);
 485                     TIMEOUT(fsm_timeout, f, f->timeouttime);
 486                     --f->retransmits;
 487                 }
 488                 break;
 489
 490     case REQSENT:
 491     case ACKRCVD:
 492     case ACKSENT:
 493                 if (f->retransmits <= 0) {
 494                     FSMDEBUG((LOG_WARNING, "%s: timeout sending Config-Requests state=%d\n",
 495                            PROTO_NAME(f), f->state));
 496                     f->state = STOPPED;
 497                     if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
 498                                 (*f->callbacks->finished)(f);
 499
 500                 } else {
 501                     FSMDEBUG((LOG_WARNING, "%s: timeout resending Config-Request state=%d\n",
 502                            PROTO_NAME(f), f->state));
 503                     /* Retransmit the configure-request */
 504                     if (f->callbacks->retransmit)
 505                                 (*f->callbacks->retransmit)(f);
 506                     fsm_sconfreq(f, 1);         /* Re-send Configure-Request */
 507                     if( f->state == ACKRCVD )
 508                                 f->state = REQSENT;
 509                 }
 510                 break;
 511
 512     default:
 513                 FSMDEBUG((LOG_INFO, "%s: Timeout event in state %d!\n",
 514                                   PROTO_NAME(f), f->state));
 515             }
 516 }
 517
 518
 519 /*
 520  * fsm_rconfreq - Receive Configure-Request.
 521  */
 522 static void fsm_rconfreq(fsm *f, u_char id, u_char *inp, int len)
 523 {
 524         int code, reject_if_disagree;
 525
 526         FSMDEBUG((LOG_INFO, "fsm_rconfreq(%s): Rcvd id %d state=%d\n",
 527                                 PROTO_NAME(f), id, f->state));
 528         switch( f->state ){
 529         case CLOSED:
 530                 /* Go away, we're closed */
 531                 fsm_sdata(f, TERMACK, id, NULL, 0);
 532                 return;
 533         case CLOSING:
 534         case STOPPING:
 535                 return;
 536
 537         case OPENED:
 538                 /* Go down and restart negotiation */
 539                 if( f->callbacks->down )
 540                         (*f->callbacks->down)(f);       /* Inform upper layers */
 541                 fsm_sconfreq(f, 0);             /* Send initial Configure-Request */
 542                 break;
 543
 544         case STOPPED:
 545                 /* Negotiation started by our peer */
 546                 fsm_sconfreq(f, 0);             /* Send initial Configure-Request */
 547                 f->state = REQSENT;
 548                 break;
 549         }
 550
 551         /*
 552         * Pass the requested configuration options
 553         * to protocol-specific code for checking.
 554         */
 555         if (f->callbacks->reqci){               /* Check CI */
 556                 reject_if_disagree = (f->nakloops >= f->maxnakloops);
 557                 code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
 558         }
 559         else if (len)
 560                 code = CONFREJ;                 /* Reject all CI */
 561         else
 562                 code = CONFACK;
 563
 564         /* send the Ack, Nak or Rej to the peer */
 565         fsm_sdata(f, (u_char)code, id, inp, len);
 566
 567         if (code == CONFACK) {
 568                 if (f->state == ACKRCVD) {
 569                         UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 570                         f->state = OPENED;
 571                         if (f->callbacks->up)
 572                                 (*f->callbacks->up)(f); /* Inform upper layers */
 573                 }
 574                 else
 575                         f->state = ACKSENT;
 576                 f->nakloops = 0;
 577         }
 578         else {
 579                 /* we sent CONFACK or CONFREJ */
 580                 if (f->state != ACKRCVD)
 581                         f->state = REQSENT;
 582                 if( code == CONFNAK )
 583                         ++f->nakloops;
 584         }
 585 }
 586
 587
 588 /*
 589  * fsm_rconfack - Receive Configure-Ack.
 590  */
 591 static void fsm_rconfack(fsm *f, int id, u_char *inp, int len)
 592 {
 593         FSMDEBUG((LOG_INFO, "fsm_rconfack(%s): Rcvd id %d state=%d\n",
 594                                 PROTO_NAME(f), id, f->state));
 595
 596         if (id != f->reqid || f->seen_ack)              /* Expected id? */
 597                 return;                                 /* Nope, toss... */
 598         if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len):
 599                                                                 (len == 0)) ){
 600                 /* Ack is bad - ignore it */
 601                 FSMDEBUG((LOG_INFO, "%s: received bad Ack (length %d)\n",
 602                                         PROTO_NAME(f), len));
 603                 return;
 604         }
 605         f->seen_ack = 1;
 606
 607         switch (f->state) {
 608         case CLOSED:
 609         case STOPPED:
 610                 fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
 611                 break;
 612
 613         case REQSENT:
 614                 f->state = ACKRCVD;
 615                 f->retransmits = f->maxconfreqtransmits;
 616                 break;
 617
 618         case ACKRCVD:
 619                 /* Huh? an extra valid Ack? oh well... */
 620                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 621                 fsm_sconfreq(f, 0);
 622                 f->state = REQSENT;
 623                 break;
 624
 625         case ACKSENT:
 626                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 627                 f->state = OPENED;
 628                 f->retransmits = f->maxconfreqtransmits;
 629                 if (f->callbacks->up)
 630                         (*f->callbacks->up)(f); /* Inform upper layers */
 631                 break;
 632
 633         case OPENED:
 634                 /* Go down and restart negotiation */
 635                 if (f->callbacks->down)
 636                         (*f->callbacks->down)(f);       /* Inform upper layers */
 637                 fsm_sconfreq(f, 0);             /* Send initial Configure-Request */
 638                 f->state = REQSENT;
 639                 break;
 640         }
 641 }
 642
 643
 644 /*
 645  * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
 646  */
 647 static void fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len)
 648 {
 649         int (*proc) (fsm *, u_char *, int);
 650         int ret;
 651
 652         FSMDEBUG((LOG_INFO, "fsm_rconfnakrej(%s): Rcvd id %d state=%d\n",
 653                                 PROTO_NAME(f), id, f->state));
 654
 655         if (id != f->reqid || f->seen_ack)      /* Expected id? */
 656                 return;                         /* Nope, toss... */
 657         proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
 658         if (!proc || !(ret = proc(f, inp, len))) {
 659                 /* Nak/reject is bad - ignore it */
 660                 FSMDEBUG((LOG_INFO, "%s: received bad %s (length %d)\n",
 661                                         PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len));
 662                 return;
 663         }
 664         f->seen_ack = 1;
 665
 666         switch (f->state) {
 667         case CLOSED:
 668         case STOPPED:
 669                 fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
 670                 break;
 671
 672         case REQSENT:
 673         case ACKSENT:
 674                 /* They didn't agree to what we wanted - try another request */
 675                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 676                 if (ret < 0)
 677                         f->state = STOPPED;             /* kludge for stopping CCP */
 678                 else
 679                         fsm_sconfreq(f, 0);             /* Send Configure-Request */
 680                 break;
 681
 682         case ACKRCVD:
 683                 /* Got a Nak/reject when we had already had an Ack?? oh well... */
 684                 UNTIMEOUT(fsm_timeout, f);      /* Cancel timeout */
 685                 fsm_sconfreq(f, 0);
 686                 f->state = REQSENT;
 687                 break;
 688
 689         case OPENED:
 690                 /* Go down and restart negotiation */
 691                 if (f->callbacks->down)
 692                         (*f->callbacks->down)(f);       /* Inform upper layers */
 693                 fsm_sconfreq(f, 0);             /* Send initial Configure-Request */
 694                 f->state = REQSENT;
 695                 break;
 696         }
 697 }
 698
 699
 700 /*
 701  * fsm_rtermreq - Receive Terminate-Req.
 702  */
 703 static void fsm_rtermreq(fsm *f, int id, u_char *p, int len)
 704 {
 705         FSMDEBUG((LOG_INFO, "fsm_rtermreq(%s): Rcvd id %d state=%d\n",
 706                                 PROTO_NAME(f), id, f->state));
 707
 708         switch (f->state) {
 709         case ACKRCVD:
 710         case ACKSENT:
 711                 f->state = REQSENT;             /* Start over but keep trying */
 712                 break;
 713
 714         case OPENED:
 715                 if (len > 0) {
 716                         FSMDEBUG((LOG_INFO, "%s terminated by peer (%x)\n", PROTO_NAME(f), p));
 717                 } else {
 718                         FSMDEBUG((LOG_INFO, "%s terminated by peer\n", PROTO_NAME(f)));
 719                 }
 720                 if (f->callbacks->down)
 721                         (*f->callbacks->down)(f);       /* Inform upper layers */
 722                 f->retransmits = 0;
 723                 f->state = STOPPING;
 724                 TIMEOUT(fsm_timeout, f, f->timeouttime);
 725                 break;
 726         }
 727
 728         fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
 729 }
 730
 731
 732 /*
 733  * fsm_rtermack - Receive Terminate-Ack.
 734  */
 735 static void fsm_rtermack(fsm *f)
 736 {
 737         FSMDEBUG((LOG_INFO, "fsm_rtermack(%s): state=%d\n",
 738                                 PROTO_NAME(f), f->state));
 739
 740         switch (f->state) {
 741         case CLOSING:
 742                 UNTIMEOUT(fsm_timeout, f);
 743                 f->state = CLOSED;
 744                 if( f->callbacks->finished )
 745                         (*f->callbacks->finished)(f);
 746                 break;
 747         case STOPPING:
 748                 UNTIMEOUT(fsm_timeout, f);
 749                 f->state = STOPPED;
 750                 if( f->callbacks->finished )
 751                         (*f->callbacks->finished)(f);
 752                 break;
 753
 754         case ACKRCVD:
 755                 f->state = REQSENT;
 756                 break;
 757
 758         case OPENED:
 759                 if (f->callbacks->down)
 760                         (*f->callbacks->down)(f);       /* Inform upper layers */
 761                 fsm_sconfreq(f, 0);
 762                 break;
 763         }
 764 }
 765
 766
 767 /*
 768  * fsm_rcoderej - Receive an Code-Reject.
 769  */
 770 static void fsm_rcoderej(fsm *f, u_char *inp, int len)
 771 {
 772         u_char code, id;
 773
 774         FSMDEBUG((LOG_INFO, "fsm_rcoderej(%s): state=%d\n",
 775                                 PROTO_NAME(f), f->state));
 776
 777         if (len < HEADERLEN) {
 778                 FSMDEBUG((LOG_INFO, "fsm_rcoderej: Rcvd short Code-Reject packet!\n"));
 779                 return;
 780         }
 781         GETCHAR(code, inp);
 782         GETCHAR(id, inp);
 783         FSMDEBUG((LOG_WARNING, "%s: Rcvd Code-Reject for code %d, id %d\n",
 784                                 PROTO_NAME(f), code, id));
 785
 786         if( f->state == ACKRCVD )
 787                 f->state = REQSENT;
 788 }
 789
 790
 791 /*
 792  * fsm_sconfreq - Send a Configure-Request.
 793  */
 794 static void fsm_sconfreq(fsm *f, int retransmit)
 795 {
 796         u_char *outp;
 797         int cilen;
 798
 799         if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
 800                 /* Not currently negotiating - reset options */
 801                 if( f->callbacks->resetci )
 802                         (*f->callbacks->resetci)(f);
 803                 f->nakloops = 0;
 804                 }
 805
 806         if( !retransmit ){
 807                 /* New request - reset retransmission counter, use new ID */
 808                 f->retransmits = f->maxconfreqtransmits;
 809                 f->reqid = ++f->id;
 810         }
 811
 812         f->seen_ack = 0;
 813
 814         /*
 815          * Make up the request packet
 816          */
 817         outp = outpacket_buf[f->unit] + PPP_HDRLEN + HEADERLEN;
 818         if( f->callbacks->cilen && f->callbacks->addci ){
 819                 cilen = (*f->callbacks->cilen)(f);
 820                 if( cilen > peer_mru[f->unit] - (int)HEADERLEN )
 821                         cilen = peer_mru[f->unit] - HEADERLEN;
 822                 if (f->callbacks->addci)
 823                         (*f->callbacks->addci)(f, outp, &cilen);
 824         } else
 825                 cilen = 0;
 826
 827         /* send the request to our peer */
 828         fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
 829
 830         /* start the retransmit timer */
 831         --f->retransmits;
 832         TIMEOUT(fsm_timeout, f, f->timeouttime);
 833
 834         FSMDEBUG((LOG_INFO, "%s: sending Configure-Request, id %d\n",
 835                                 PROTO_NAME(f), f->reqid));
 836 }
 837
 838 #endif /* PPP_SUPPORT */