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

   1 /*****************************************************************************
   2 * lcp.c - Network Link Control Protocol 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.
  32 *****************************************************************************/
  33
  34 /*
  35  * lcp.c - PPP Link Control Protocol.
  36  *
  37  * Copyright (c) 1989 Carnegie Mellon University.
  38  * All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms are permitted
  41  * provided that the above copyright notice and this paragraph are
  42  * duplicated in all such forms and that any documentation,
  43  * advertising materials, and other materials related to such
  44  * distribution and use acknowledge that the software was developed
  45  * by Carnegie Mellon University.  The name of the
  46  * University may not be used to endorse or promote products derived
  47  * from this software without specific prior written permission.
  48  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  49  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  50  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  51  */
  52 #include "ppp.h"
  53 #if PPP_SUPPORT > 0
  54 #include "fsm.h"
  55 #include "chap.h"
  56 #include "magic.h"
  57 #include "auth.h"
  58 #include "lcp.h"
  59 #include "pppdebug.h"
  60
  61
  62 /*************************/
  63 /*** LOCAL DEFINITIONS ***/
  64 /*************************/
  65 /*
  66  * Length of each type of configuration option (in octets)
  67  */
  68 #define CILEN_VOID      2
  69 #define CILEN_CHAR      3
  70 #define CILEN_SHORT     4       /* CILEN_VOID + sizeof(short) */
  71 #define CILEN_CHAP      5       /* CILEN_VOID + sizeof(short) + 1 */
  72 #define CILEN_LONG      6       /* CILEN_VOID + sizeof(long) */
  73 #define CILEN_LQR       8       /* CILEN_VOID + sizeof(short) + sizeof(long) */
  74 #define CILEN_CBCP      3
  75
  76
  77 /***********************************/
  78 /*** LOCAL FUNCTION DECLARATIONS ***/
  79 /***********************************/
  80 /*
  81  * Callbacks for fsm code.  (CI = Configuration Information)
  82  */
  83 static void lcp_resetci (fsm*);         /* Reset our CI */
  84 static int  lcp_cilen (fsm*);                   /* Return length of our CI */
  85 static void lcp_addci (fsm*, u_char*, int*);       /* Add our CI to pkt */
  86 static int  lcp_ackci (fsm*, u_char*, int);/* Peer ack'd our CI */
  87 static int  lcp_nakci (fsm*, u_char*, int);/* Peer nak'd our CI */
  88 static int  lcp_rejci (fsm*, u_char*, int);/* Peer rej'd our CI */
  89 static int  lcp_reqci (fsm*, u_char*, int*, int);  /* Rcv peer CI */
  90 static void lcp_up (fsm*);                          /* We're UP */
  91 static void lcp_down (fsm*);                /* We're DOWN */
  92 static void lcp_starting (fsm*);            /* We need lower layer up */
  93 static void lcp_finished (fsm*);                /* We need lower layer down */
  94 static int  lcp_extcode (fsm*, int, u_char, u_char*, int);
  95
  96 static void lcp_rprotrej (fsm*, u_char*, int);
  97
  98 /*
  99  * routines to send LCP echos to peer
 100  */
 101 static void lcp_echo_lowerup (int);
 102 static void lcp_echo_lowerdown (int);
 103 static void LcpEchoTimeout (void*);
 104 static void lcp_received_echo_reply (fsm*, int, u_char*, int);
 105 static void LcpSendEchoRequest (fsm*);
 106 static void LcpLinkFailure (fsm*);
 107 static void LcpEchoCheck (fsm*);
 108
 109 /*
 110  * Protocol entry points.
 111  * Some of these are called directly.
 112  */
 113 static void lcp_input (int, u_char *, int);
 114 static void lcp_protrej (int);
 115
 116 #define CODENAME(x)     ((x) == CONFACK ? "ACK" : \
 117                          (x) == CONFNAK ? "NAK" : "REJ")
 118
 119
 120 /******************************/
 121 /*** PUBLIC DATA STRUCTURES ***/
 122 /******************************/
 123 /* global vars */
 124 LinkPhase lcp_phase[NUM_PPP];                   /* Phase of link session (RFC 1661) */
 125 lcp_options lcp_wantoptions[NUM_PPP];   /* Options that we want to request */
 126 lcp_options lcp_gotoptions[NUM_PPP];    /* Options that peer ack'd */
 127 lcp_options lcp_allowoptions[NUM_PPP];  /* Options we allow peer to request */
 128 lcp_options lcp_hisoptions[NUM_PPP];    /* Options that we ack'd */
 129 ext_accm xmit_accm[NUM_PPP];                    /* extended transmit ACCM */
 130
 131
 132
 133 /*****************************/
 134 /*** LOCAL DATA STRUCTURES ***/
 135 /*****************************/
 136 static fsm lcp_fsm[NUM_PPP];                    /* LCP fsm structure (global)*/
 137 static u_int     lcp_echo_interval = LCP_ECHOINTERVAL; /* Interval between LCP echo-requests */
 138 static u_int     lcp_echo_fails = LCP_MAXECHOFAILS; /* Tolerance to unanswered echo-requests */
 139 static u32_t lcp_echos_pending = 0;     /* Number of outstanding echo msgs */
 140 static u32_t lcp_echo_number   = 0;     /* ID number of next echo frame */
 141 static u32_t lcp_echo_timer_running = 0;  /* TRUE if a timer is running */
 142
 143 static u_char nak_buffer[PPP_MRU];      /* where we construct a nak packet */
 144
 145 static fsm_callbacks lcp_callbacks = {  /* LCP callback routines */
 146     lcp_resetci,                /* Reset our Configuration Information */
 147     lcp_cilen,                  /* Length of our Configuration Information */
 148     lcp_addci,                  /* Add our Configuration Information */
 149     lcp_ackci,                  /* ACK our Configuration Information */
 150     lcp_nakci,                  /* NAK our Configuration Information */
 151     lcp_rejci,                  /* Reject our Configuration Information */
 152     lcp_reqci,                  /* Request peer's Configuration Information */
 153     lcp_up,                             /* Called when fsm reaches OPENED state */
 154     lcp_down,                   /* Called when fsm leaves OPENED state */
 155     lcp_starting,               /* Called when we want the lower layer up */
 156     lcp_finished,               /* Called when we want the lower layer down */
 157     NULL,                               /* Called when Protocol-Reject received */
 158     NULL,                               /* Retransmission is necessary */
 159     lcp_extcode,                /* Called to handle LCP-specific codes */
 160     "LCP"                               /* String name of protocol */
 161 };
 162
 163 struct protent lcp_protent = {
 164     PPP_LCP,
 165     lcp_init,
 166     lcp_input,
 167     lcp_protrej,
 168     lcp_lowerup,
 169     lcp_lowerdown,
 170     lcp_open,
 171     lcp_close,
 172 #if 0
 173     lcp_printpkt,
 174     NULL,
 175 #endif
 176     1,
 177     "LCP",
 178 #if 0
 179     NULL,
 180     NULL,
 181     NULL
 182 #endif
 183 };
 184
 185 int lcp_loopbackfail = DEFLOOPBACKFAIL;
 186
 187
 188
 189 /***********************************/
 190 /*** PUBLIC FUNCTION DEFINITIONS ***/
 191 /***********************************/
 192 /*
 193  * lcp_init - Initialize LCP.
 194  */
 195 void lcp_init(int unit)
 196 {
 197         fsm *f = &lcp_fsm[unit];
 198         lcp_options *wo = &lcp_wantoptions[unit];
 199         lcp_options *ao = &lcp_allowoptions[unit];
 200
 201         f->unit = unit;
 202         f->protocol = PPP_LCP;
 203         f->callbacks = &lcp_callbacks;
 204
 205         fsm_init(f);
 206
 207         wo->passive = 0;
 208         wo->silent = 0;
 209         wo->restart = 0;                        /* Set to 1 in kernels or multi-line
 210                                                                  * implementations */
 211         wo->neg_mru = 1;
 212         wo->mru = PPP_DEFMRU;
 213         wo->neg_asyncmap = 1;
 214         wo->asyncmap = 0x00000000l;     /* Assume don't need to escape any ctl chars. */
 215         wo->neg_chap = 0;                       /* Set to 1 on server */
 216         wo->neg_upap = 0;                       /* Set to 1 on server */
 217         wo->chap_mdtype = CHAP_DIGEST_MD5;
 218         wo->neg_magicnumber = 1;
 219         wo->neg_pcompression = 1;
 220         wo->neg_accompression = 1;
 221         wo->neg_lqr = 0;                        /* no LQR implementation yet */
 222         wo->neg_cbcp = 0;
 223
 224         ao->neg_mru = 1;
 225         ao->mru = PPP_MAXMRU;
 226         ao->neg_asyncmap = 1;
 227         ao->asyncmap = 0x00000000l;     /* Assume don't need to escape any ctl chars. */
 228         ao->neg_chap = (CHAP_SUPPORT != 0);
 229         ao->chap_mdtype = CHAP_DIGEST_MD5;
 230         ao->neg_upap = (PAP_SUPPORT != 0);
 231         ao->neg_magicnumber = 1;
 232         ao->neg_pcompression = 1;
 233         ao->neg_accompression = 1;
 234         ao->neg_lqr = 0;                        /* no LQR implementation yet */
 235         ao->neg_cbcp = (CBCP_SUPPORT != 0);
 236
 237         /*
 238          * Set transmit escape for the flag and escape characters plus anything
 239          * set for the allowable options.
 240          */
 241         memset(xmit_accm[unit], 0, sizeof(xmit_accm[0]));
 242         xmit_accm[unit][15] = 0x60;
 243         xmit_accm[unit][0] = (u_char)(ao->asyncmap & 0xFF);
 244         xmit_accm[unit][1] = (u_char)((ao->asyncmap >> 8) & 0xFF);
 245         xmit_accm[unit][2] = (u_char)((ao->asyncmap >> 16) & 0xFF);
 246         xmit_accm[unit][3] = (u_char)((ao->asyncmap >> 24) & 0xFF);
 247         LCPDEBUG((LOG_INFO, "lcp_init: xmit_accm=%X %X %X %X\n",
 248                                 xmit_accm[unit][0],
 249                                 xmit_accm[unit][1],
 250                                 xmit_accm[unit][2],
 251                                 xmit_accm[unit][3]));
 252
 253         lcp_phase[unit] = PHASE_INITIALIZE;
 254 }
 255
 256
 257 /*
 258  * lcp_open - LCP is allowed to come up.
 259  */
 260 void lcp_open(int unit)
 261 {
 262         fsm *f = &lcp_fsm[unit];
 263         lcp_options *wo = &lcp_wantoptions[unit];
 264
 265         f->flags = 0;
 266         if (wo->passive)
 267                 f->flags |= OPT_PASSIVE;
 268         if (wo->silent)
 269                 f->flags |= OPT_SILENT;
 270         fsm_open(f);
 271
 272         lcp_phase[unit] = PHASE_ESTABLISH;
 273 }
 274
 275
 276 /*
 277  * lcp_close - Take LCP down.
 278  */
 279 void lcp_close(int unit, char *reason)
 280 {
 281         fsm *f = &lcp_fsm[unit];
 282
 283         if (lcp_phase[unit] != PHASE_DEAD)
 284                 lcp_phase[unit] = PHASE_TERMINATE;
 285         if (f->state == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT)) {
 286                 /*
 287                  * This action is not strictly according to the FSM in RFC1548,
 288                  * but it does mean that the program terminates if you do an
 289                  * lcp_close() in passive/silent mode when a connection hasn't
 290                  * been established.
 291                  */
 292                 f->state = CLOSED;
 293                 lcp_finished(f);
 294         }
 295         else
 296                 fsm_close(&lcp_fsm[unit], reason);
 297 }
 298
 299
 300 /*
 301  * lcp_lowerup - The lower layer is up.
 302  */
 303 void lcp_lowerup(int unit)
 304 {
 305         lcp_options *wo = &lcp_wantoptions[unit];
 306
 307         /*
 308         * Don't use A/C or protocol compression on transmission,
 309         * but accept A/C and protocol compressed packets
 310         * if we are going to ask for A/C and protocol compression.
 311         */
 312         ppp_set_xaccm(unit, &xmit_accm[unit]);
 313         ppp_send_config(unit, PPP_MRU, 0xffffffffl, 0, 0);
 314         ppp_recv_config(unit, PPP_MRU, 0x00000000l,
 315                                         wo->neg_pcompression, wo->neg_accompression);
 316         peer_mru[unit] = PPP_MRU;
 317         lcp_allowoptions[unit].asyncmap
 318                 = (u_long)xmit_accm[unit][0]
 319                         | ((u_long)xmit_accm[unit][1] << 8)
 320                         | ((u_long)xmit_accm[unit][2] << 16)
 321                         | ((u_long)xmit_accm[unit][3] << 24);
 322         LCPDEBUG((LOG_INFO, "lcp_lowerup: asyncmap=%X %X %X %X\n",
 323                                 xmit_accm[unit][3],
 324                                 xmit_accm[unit][2],
 325                                 xmit_accm[unit][1],
 326                                 xmit_accm[unit][0]));
 327
 328         fsm_lowerup(&lcp_fsm[unit]);
 329 }
 330
 331
 332 /*
 333  * lcp_lowerdown - The lower layer is down.
 334  */
 335 void lcp_lowerdown(int unit)
 336 {
 337         fsm_lowerdown(&lcp_fsm[unit]);
 338 }
 339
 340 /*
 341  * lcp_sprotrej - Send a Protocol-Reject for some protocol.
 342  */
 343 void lcp_sprotrej(int unit, u_char *p, int len)
 344 {
 345         /*
 346         * Send back the protocol and the information field of the
 347         * rejected packet.  We only get here if LCP is in the OPENED state.
 348         */
 349
 350         fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
 351                                 p, len);
 352 }
 353
 354
 355
 356 /**********************************/
 357 /*** LOCAL FUNCTION DEFINITIONS ***/
 358 /**********************************/
 359 /*
 360  * lcp_input - Input LCP packet.
 361  */
 362 static void lcp_input(int unit, u_char *p, int len)
 363 {
 364         fsm *f = &lcp_fsm[unit];
 365
 366         fsm_input(f, p, len);
 367 }
 368
 369
 370 /*
 371  * lcp_extcode - Handle a LCP-specific code.
 372  */
 373 static int lcp_extcode(fsm *f, int code, u_char id, u_char *inp, int len)
 374 {
 375         u_char *magp;
 376
 377         switch( code ){
 378         case PROTREJ:
 379                 lcp_rprotrej(f, inp, len);
 380                 break;
 381
 382         case ECHOREQ:
 383                 if (f->state != OPENED)
 384                         break;
 385                 LCPDEBUG((LOG_INFO, "lcp: Echo-Request, Rcvd id %d\n", id));
 386                 magp = inp;
 387                 PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);
 388                 fsm_sdata(f, ECHOREP, id, inp, len);
 389                 break;
 390
 391         case ECHOREP:
 392                 lcp_received_echo_reply(f, id, inp, len);
 393                 break;
 394
 395         case DISCREQ:
 396                 break;
 397
 398         default:
 399                 return 0;
 400         }
 401         return 1;
 402 }
 403
 404
 405 /*
 406  * lcp_rprotrej - Receive an Protocol-Reject.
 407  *
 408  * Figure out which protocol is rejected and inform it.
 409  */
 410 static void lcp_rprotrej(fsm *f, u_char *inp, int len)
 411 {
 412         int i;
 413         struct protent *protp;
 414         u_short prot;
 415
 416         if (len < sizeof (u_short)) {
 417                 LCPDEBUG((LOG_INFO,
 418                                 "lcp_rprotrej: Rcvd short Protocol-Reject packet!\n"));
 419                 return;
 420         }
 421
 422         GETSHORT(prot, inp);
 423
 424         LCPDEBUG((LOG_INFO,
 425                         "lcp_rprotrej: Rcvd Protocol-Reject packet for %x!\n",
 426                         prot));
 427
 428         /*
 429         * Protocol-Reject packets received in any state other than the LCP
 430         * OPENED state SHOULD be silently discarded.
 431         */
 432         if( f->state != OPENED ){
 433                 LCPDEBUG((LOG_INFO, "Protocol-Reject discarded: LCP in state %d\n",
 434                                 f->state));
 435                 return;
 436         }
 437
 438         /*
 439         * Upcall the proper Protocol-Reject routine.
 440         */
 441         for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i)
 442                 if (protp->protocol == prot && protp->enabled_flag) {
 443                         (*protp->protrej)(f->unit);
 444                         return;
 445                 }
 446
 447         LCPDEBUG((LOG_WARNING, "Protocol-Reject for unsupported protocol 0x%x\n",
 448                         prot));
 449 }
 450
 451
 452 /*
 453  * lcp_protrej - A Protocol-Reject was received.
 454  */
 455 static void lcp_protrej(int unit)
 456 {
 457         (void)unit;
 458         /*
 459         * Can't reject LCP!
 460         */
 461         LCPDEBUG((LOG_WARNING,
 462                         "lcp_protrej: Received Protocol-Reject for LCP!\n"));
 463         fsm_protreject(&lcp_fsm[unit]);
 464 }
 465
 466
 467 /*
 468  * lcp_resetci - Reset our CI.
 469  */
 470 static void lcp_resetci(fsm *f)
 471 {
 472         lcp_wantoptions[f->unit].magicnumber = magic();
 473         lcp_wantoptions[f->unit].numloops = 0;
 474         lcp_gotoptions[f->unit] = lcp_wantoptions[f->unit];
 475         peer_mru[f->unit] = PPP_MRU;
 476         auth_reset(f->unit);
 477 }
 478
 479
 480 /*
 481  * lcp_cilen - Return length of our CI.
 482  */
 483 static int lcp_cilen(fsm *f)
 484 {
 485         lcp_options *go = &lcp_gotoptions[f->unit];
 486
 487 #define LENCIVOID(neg)  ((neg) ? CILEN_VOID : 0)
 488 #define LENCICHAP(neg)  ((neg) ? CILEN_CHAP : 0)
 489 #define LENCISHORT(neg) ((neg) ? CILEN_SHORT : 0)
 490 #define LENCILONG(neg)  ((neg) ? CILEN_LONG : 0)
 491 #define LENCILQR(neg)   ((neg) ? CILEN_LQR: 0)
 492 #define LENCICBCP(neg)  ((neg) ? CILEN_CBCP: 0)
 493         /*
 494         * NB: we only ask for one of CHAP and UPAP, even if we will
 495         * accept either.
 496         */
 497         return (LENCISHORT(go->neg_mru && go->mru != PPP_DEFMRU) +
 498                 LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl) +
 499                 LENCICHAP(go->neg_chap) +
 500                 LENCISHORT(!go->neg_chap && go->neg_upap) +
 501                 LENCILQR(go->neg_lqr) +
 502                 LENCICBCP(go->neg_cbcp) +
 503                 LENCILONG(go->neg_magicnumber) +
 504                 LENCIVOID(go->neg_pcompression) +
 505                 LENCIVOID(go->neg_accompression));
 506 }
 507
 508
 509 /*
 510  * lcp_addci - Add our desired CIs to a packet.
 511  */
 512 static void lcp_addci(fsm *f, u_char *ucp, int *lenp)
 513 {
 514         lcp_options *go = &lcp_gotoptions[f->unit];
 515         u_char *start_ucp = ucp;
 516
 517 #define ADDCIVOID(opt, neg) \
 518         if (neg) { \
 519             LCPDEBUG((LOG_INFO, "lcp_addci: opt=%d\n", opt)); \
 520                 PUTCHAR(opt, ucp); \
 521                 PUTCHAR(CILEN_VOID, ucp); \
 522         }
 523 #define ADDCISHORT(opt, neg, val) \
 524         if (neg) { \
 525             LCPDEBUG((LOG_INFO, "lcp_addci: INT opt=%d %X\n", opt, val)); \
 526                 PUTCHAR(opt, ucp); \
 527                 PUTCHAR(CILEN_SHORT, ucp); \
 528                 PUTSHORT(val, ucp); \
 529         }
 530 #define ADDCICHAP(opt, neg, val, digest) \
 531         if (neg) { \
 532             LCPDEBUG((LOG_INFO, "lcp_addci: CHAP opt=%d %X\n", opt, val)); \
 533                 PUTCHAR(opt, ucp); \
 534                 PUTCHAR(CILEN_CHAP, ucp); \
 535                 PUTSHORT(val, ucp); \
 536                 PUTCHAR(digest, ucp); \
 537         }
 538 #define ADDCILONG(opt, neg, val) \
 539         if (neg) { \
 540             LCPDEBUG((LOG_INFO, "lcp_addci: L opt=%d %lX\n", opt, val)); \
 541                 PUTCHAR(opt, ucp); \
 542                 PUTCHAR(CILEN_LONG, ucp); \
 543                 PUTLONG(val, ucp); \
 544         }
 545 #define ADDCILQR(opt, neg, val) \
 546         if (neg) { \
 547             LCPDEBUG((LOG_INFO, "lcp_addci: LQR opt=%d %lX\n", opt, val)); \
 548                 PUTCHAR(opt, ucp); \
 549                 PUTCHAR(CILEN_LQR, ucp); \
 550                 PUTSHORT(PPP_LQR, ucp); \
 551                 PUTLONG(val, ucp); \
 552         }
 553 #define ADDCICHAR(opt, neg, val) \
 554         if (neg) { \
 555             LCPDEBUG((LOG_INFO, "lcp_addci: CHAR opt=%d %X '%z'\n", opt, val, val)); \
 556                 PUTCHAR(opt, ucp); \
 557                 PUTCHAR(CILEN_CHAR, ucp); \
 558                 PUTCHAR(val, ucp); \
 559         }
 560
 561         ADDCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
 562         ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl,
 563                         go->asyncmap);
 564         ADDCICHAP(CI_AUTHTYPE, go->neg_chap, PPP_CHAP, go->chap_mdtype);
 565         ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
 566         ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
 567         ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
 568         ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
 569         ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
 570         ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
 571
 572         if (ucp - start_ucp != *lenp) {
 573                 /* this should never happen, because peer_mtu should be 1500 */
 574                 LCPDEBUG((LOG_ERR, "Bug in lcp_addci: wrong length\n"));
 575         }
 576 }
 577
 578
 579 /*
 580  * lcp_ackci - Ack our CIs.
 581  * This should not modify any state if the Ack is bad.
 582  *
 583  * Returns:
 584  *      0 - Ack was bad.
 585  *      1 - Ack was good.
 586  */
 587 static int lcp_ackci(fsm *f, u_char *p, int len)
 588 {
 589         lcp_options *go = &lcp_gotoptions[f->unit];
 590         u_char cilen, citype, cichar;
 591         u_short cishort;
 592         u32_t cilong;
 593
 594         /*
 595         * CIs must be in exactly the same order that we sent.
 596         * Check packet length and CI length at each step.
 597         * If we find any deviations, then this packet is bad.
 598         */
 599 #define ACKCIVOID(opt, neg) \
 600         if (neg) { \
 601                 if ((len -= CILEN_VOID) < 0) \
 602                         goto bad; \
 603                 GETCHAR(citype, p); \
 604                 GETCHAR(cilen, p); \
 605                 if (cilen != CILEN_VOID || \
 606                                 citype != opt) \
 607                         goto bad; \
 608         }
 609 #define ACKCISHORT(opt, neg, val) \
 610         if (neg) { \
 611                 if ((len -= CILEN_SHORT) < 0) \
 612                         goto bad; \
 613                 GETCHAR(citype, p); \
 614                 GETCHAR(cilen, p); \
 615                 if (cilen != CILEN_SHORT || \
 616                                 citype != opt) \
 617                         goto bad; \
 618                 GETSHORT(cishort, p); \
 619                 if (cishort != val) \
 620                         goto bad; \
 621         }
 622 #define ACKCICHAR(opt, neg, val) \
 623         if (neg) { \
 624                 if ((len -= CILEN_CHAR) < 0) \
 625                         goto bad; \
 626                 GETCHAR(citype, p); \
 627                 GETCHAR(cilen, p); \
 628                 if (cilen != CILEN_CHAR || \
 629                                 citype != opt) \
 630                         goto bad; \
 631                 GETCHAR(cichar, p); \
 632                 if (cichar != val) \
 633                         goto bad; \
 634         }
 635 #define ACKCICHAP(opt, neg, val, digest) \
 636         if (neg) { \
 637                 if ((len -= CILEN_CHAP) < 0) \
 638                         goto bad; \
 639                 GETCHAR(citype, p); \
 640                 GETCHAR(cilen, p); \
 641                 if (cilen != CILEN_CHAP || \
 642                                 citype != opt) \
 643                         goto bad; \
 644                 GETSHORT(cishort, p); \
 645                 if (cishort != val) \
 646                         goto bad; \
 647                 GETCHAR(cichar, p); \
 648                 if (cichar != digest) \
 649                         goto bad; \
 650         }
 651 #define ACKCILONG(opt, neg, val) \
 652         if (neg) { \
 653                 if ((len -= CILEN_LONG) < 0) \
 654                         goto bad; \
 655                 GETCHAR(citype, p); \
 656                 GETCHAR(cilen, p); \
 657                 if (cilen != CILEN_LONG || \
 658                                 citype != opt) \
 659                         goto bad; \
 660                 GETLONG(cilong, p); \
 661                 if (cilong != val) \
 662                         goto bad; \
 663         }
 664 #define ACKCILQR(opt, neg, val) \
 665         if (neg) { \
 666                 if ((len -= CILEN_LQR) < 0) \
 667                         goto bad; \
 668                 GETCHAR(citype, p); \
 669                 GETCHAR(cilen, p); \
 670                 if (cilen != CILEN_LQR || \
 671                                 citype != opt) \
 672                         goto bad; \
 673                 GETSHORT(cishort, p); \
 674                 if (cishort != PPP_LQR) \
 675                         goto bad; \
 676                 GETLONG(cilong, p); \
 677                 if (cilong != val) \
 678                         goto bad; \
 679         }
 680
 681         ACKCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
 682         ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl,
 683                         go->asyncmap);
 684         ACKCICHAP(CI_AUTHTYPE, go->neg_chap, PPP_CHAP, go->chap_mdtype);
 685         ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
 686         ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
 687         ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
 688         ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
 689         ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
 690         ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
 691
 692         /*
 693          * If there are any remaining CIs, then this packet is bad.
 694          */
 695         if (len != 0)
 696                 goto bad;
 697         LCPDEBUG((LOG_INFO, "lcp_acki: Ack\n"));
 698         return (1);
 699 bad:
 700         LCPDEBUG((LOG_WARNING, "lcp_acki: received bad Ack!\n"));
 701         return (0);
 702 }
 703
 704
 705 /*
 706  * lcp_nakci - Peer has sent a NAK for some of our CIs.
 707  * This should not modify any state if the Nak is bad
 708  * or if LCP is in the OPENED state.
 709  *
 710  * Returns:
 711  *      0 - Nak was bad.
 712  *      1 - Nak was good.
 713  */
 714 static int lcp_nakci(fsm *f, u_char *p, int len)
 715 {
 716         lcp_options *go = &lcp_gotoptions[f->unit];
 717         lcp_options *wo = &lcp_wantoptions[f->unit];
 718         u_char citype, cichar, *next;
 719         u_short cishort;
 720         u32_t cilong;
 721         lcp_options no;         /* options we've seen Naks for */
 722         lcp_options try;                /* options to request next time */
 723         int looped_back = 0;
 724         int cilen;
 725
 726         BZERO(&no, sizeof(no));
 727         try = *go;
 728
 729         /*
 730         * Any Nak'd CIs must be in exactly the same order that we sent.
 731         * Check packet length and CI length at each step.
 732         * If we find any deviations, then this packet is bad.
 733         */
 734 #define NAKCIVOID(opt, neg, code) \
 735         if (go->neg && \
 736                         len >= CILEN_VOID && \
 737                         p[1] == CILEN_VOID && \
 738                         p[0] == opt) { \
 739                 len -= CILEN_VOID; \
 740                 INCPTR(CILEN_VOID, p); \
 741                 no.neg = 1; \
 742                 code \
 743         }
 744 #define NAKCICHAP(opt, neg, code) \
 745         if (go->neg && \
 746                         len >= CILEN_CHAP && \
 747                         p[1] == CILEN_CHAP && \
 748                         p[0] == opt) { \
 749                 len -= CILEN_CHAP; \
 750                 INCPTR(2, p); \
 751                 GETSHORT(cishort, p); \
 752                 GETCHAR(cichar, p); \
 753                 no.neg = 1; \
 754                 code \
 755         }
 756 #define NAKCICHAR(opt, neg, code) \
 757         if (go->neg && \
 758                         len >= CILEN_CHAR && \
 759                         p[1] == CILEN_CHAR && \
 760                         p[0] == opt) { \
 761                 len -= CILEN_CHAR; \
 762                 INCPTR(2, p); \
 763                 GETCHAR(cichar, p); \
 764                 no.neg = 1; \
 765                 code \
 766         }
 767 #define NAKCISHORT(opt, neg, code) \
 768         if (go->neg && \
 769                         len >= CILEN_SHORT && \
 770                         p[1] == CILEN_SHORT && \
 771                         p[0] == opt) { \
 772                 len -= CILEN_SHORT; \
 773                 INCPTR(2, p); \
 774                 GETSHORT(cishort, p); \
 775                 no.neg = 1; \
 776                 code \
 777         }
 778 #define NAKCILONG(opt, neg, code) \
 779         if (go->neg && \
 780                         len >= CILEN_LONG && \
 781                         p[1] == CILEN_LONG && \
 782                         p[0] == opt) { \
 783                 len -= CILEN_LONG; \
 784                 INCPTR(2, p); \
 785                 GETLONG(cilong, p); \
 786                 no.neg = 1; \
 787                 code \
 788         }
 789 #define NAKCILQR(opt, neg, code) \
 790         if (go->neg && \
 791                         len >= CILEN_LQR && \
 792                         p[1] == CILEN_LQR && \
 793                         p[0] == opt) { \
 794                 len -= CILEN_LQR; \
 795                 INCPTR(2, p); \
 796                 GETSHORT(cishort, p); \
 797                 GETLONG(cilong, p); \
 798                 no.neg = 1; \
 799                 code \
 800         }
 801
 802         /*
 803         * We don't care if they want to send us smaller packets than
 804         * we want.  Therefore, accept any MRU less than what we asked for,
 805         * but then ignore the new value when setting the MRU in the kernel.
 806         * If they send us a bigger MRU than what we asked, accept it, up to
 807         * the limit of the default MRU we'd get if we didn't negotiate.
 808         */
 809         if (go->neg_mru && go->mru != PPP_DEFMRU) {
 810                 NAKCISHORT(CI_MRU, neg_mru,
 811                         if (cishort <= wo->mru || cishort < PPP_DEFMRU)
 812                                 try.mru = cishort;
 813                 );
 814         }
 815
 816         /*
 817         * Add any characters they want to our (receive-side) asyncmap.
 818         */
 819         if (go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl) {
 820                 NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
 821                         try.asyncmap = go->asyncmap | cilong;
 822                 );
 823         }
 824
 825         /*
 826         * If they've nak'd our authentication-protocol, check whether
 827         * they are proposing a different protocol, or a different
 828         * hash algorithm for CHAP.
 829         */
 830         if ((go->neg_chap || go->neg_upap)
 831                         && len >= CILEN_SHORT
 832                         && p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
 833                 cilen = p[1];
 834         len -= cilen;
 835         no.neg_chap = go->neg_chap;
 836         no.neg_upap = go->neg_upap;
 837         INCPTR(2, p);
 838         GETSHORT(cishort, p);
 839         if (cishort == PPP_PAP && cilen == CILEN_SHORT) {
 840                 /*
 841                  * If we were asking for CHAP, they obviously don't want to do it.
 842                  * If we weren't asking for CHAP, then we were asking for PAP,
 843                  * in which case this Nak is bad.
 844                  */
 845                 if (!go->neg_chap)
 846                         goto bad;
 847                 try.neg_chap = 0;
 848
 849         } else if (cishort == PPP_CHAP && cilen == CILEN_CHAP) {
 850                 GETCHAR(cichar, p);
 851                 if (go->neg_chap) {
 852                         /*
 853                          * We were asking for CHAP/MD5; they must want a different
 854                          * algorithm.  If they can't do MD5, we'll have to stop
 855                          * asking for CHAP.
 856                          */
 857                         if (cichar != go->chap_mdtype)
 858                                 try.neg_chap = 0;
 859                 } else {
 860                         /*
 861                          * Stop asking for PAP if we were asking for it.
 862                          */
 863                         try.neg_upap = 0;
 864                 }
 865
 866         } else {
 867                 /*
 868                  * We don't recognize what they're suggesting.
 869                  * Stop asking for what we were asking for.
 870                  */
 871                 if (go->neg_chap)
 872                         try.neg_chap = 0;
 873                 else
 874                         try.neg_upap = 0;
 875                 p += cilen - CILEN_SHORT;
 876         }
 877         }
 878
 879         /*
 880         * If they can't cope with our link quality protocol, we'll have
 881         * to stop asking for LQR.  We haven't got any other protocol.
 882         * If they Nak the reporting period, take their value XXX ?
 883         */
 884         NAKCILQR(CI_QUALITY, neg_lqr,
 885                 if (cishort != PPP_LQR)
 886                         try.neg_lqr = 0;
 887                 else
 888                         try.lqr_period = cilong;
 889         );
 890
 891         /*
 892         * Only implementing CBCP...not the rest of the callback options
 893         */
 894         NAKCICHAR(CI_CALLBACK, neg_cbcp,
 895                 try.neg_cbcp = 0;
 896         );
 897
 898         /*
 899         * Check for a looped-back line.
 900         */
 901         NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
 902                 try.magicnumber = magic();
 903                 looped_back = 1;
 904         );
 905
 906         /*
 907         * Peer shouldn't send Nak for protocol compression or
 908         * address/control compression requests; they should send
 909         * a Reject instead.  If they send a Nak, treat it as a Reject.
 910         */
 911         NAKCIVOID(CI_PCOMPRESSION, neg_pcompression,
 912                 try.neg_pcompression = 0;
 913         );
 914         NAKCIVOID(CI_ACCOMPRESSION, neg_accompression,
 915                 try.neg_accompression = 0;
 916         );
 917
 918         /*
 919         * There may be remaining CIs, if the peer is requesting negotiation
 920         * on an option that we didn't include in our request packet.
 921         * If we see an option that we requested, or one we've already seen
 922         * in this packet, then this packet is bad.
 923         * If we wanted to respond by starting to negotiate on the requested
 924         * option(s), we could, but we don't, because except for the
 925         * authentication type and quality protocol, if we are not negotiating
 926         * an option, it is because we were told not to.
 927         * For the authentication type, the Nak from the peer means
 928         * `let me authenticate myself with you' which is a bit pointless.
 929         * For the quality protocol, the Nak means `ask me to send you quality
 930         * reports', but if we didn't ask for them, we don't want them.
 931         * An option we don't recognize represents the peer asking to
 932         * negotiate some option we don't support, so ignore it.
 933         */
 934         while (len > CILEN_VOID) {
 935                 GETCHAR(citype, p);
 936                 GETCHAR(cilen, p);
 937                 if (cilen < CILEN_VOID || (len -= cilen) < 0)
 938                         goto bad;
 939                 next = p + cilen - 2;
 940
 941                 switch (citype) {
 942                 case CI_MRU:
 943                         if ((go->neg_mru && go->mru != PPP_DEFMRU)
 944                                         || no.neg_mru || cilen != CILEN_SHORT)
 945                                 goto bad;
 946                         GETSHORT(cishort, p);
 947                         if (cishort < PPP_DEFMRU)
 948                                 try.mru = cishort;
 949                         break;
 950                 case CI_ASYNCMAP:
 951                         if ((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl)
 952                                         || no.neg_asyncmap || cilen != CILEN_LONG)
 953                                 goto bad;
 954                         break;
 955                 case CI_AUTHTYPE:
 956                         if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap)
 957                                 goto bad;
 958                         break;
 959                 case CI_MAGICNUMBER:
 960                         if (go->neg_magicnumber || no.neg_magicnumber ||
 961                                         cilen != CILEN_LONG)
 962                                 goto bad;
 963                         break;
 964                 case CI_PCOMPRESSION:
 965                         if (go->neg_pcompression || no.neg_pcompression
 966                                         || cilen != CILEN_VOID)
 967                                 goto bad;
 968                         break;
 969                 case CI_ACCOMPRESSION:
 970                         if (go->neg_accompression || no.neg_accompression
 971                                         || cilen != CILEN_VOID)
 972                                 goto bad;
 973                         break;
 974                 case CI_QUALITY:
 975                         if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
 976                                 goto bad;
 977                         break;
 978                 }
 979                 p = next;
 980         }
 981
 982         /* If there is still anything left, this packet is bad. */
 983         if (len != 0)
 984                 goto bad;
 985
 986         /*
 987         * OK, the Nak is good.  Now we can update state.
 988         */
 989         if (f->state != OPENED) {
 990                 if (looped_back) {
 991                         if (++try.numloops >= lcp_loopbackfail) {
 992                                 LCPDEBUG((LOG_NOTICE, "Serial line is looped back.\n"));
 993                                 lcp_close(f->unit, "Loopback detected");
 994                         }
 995                 }
 996                 else
 997                         try.numloops = 0;
 998                 *go = try;
 999         }
1000
1001         return 1;
1002
1003 bad:
1004         LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!\n"));
1005         return 0;
1006 }
1007
1008
1009 /*
1010  * lcp_rejci - Peer has Rejected some of our CIs.
1011  * This should not modify any state if the Reject is bad
1012  * or if LCP is in the OPENED state.
1013  *
1014  * Returns:
1015  *      0 - Reject was bad.
1016  *      1 - Reject was good.
1017  */
1018 static int lcp_rejci(fsm *f, u_char *p, int len)
1019 {
1020         lcp_options *go = &lcp_gotoptions[f->unit];
1021         u_char cichar;
1022         u_short cishort;
1023         u32_t cilong;
1024         lcp_options try;                /* options to request next time */
1025
1026         try = *go;
1027
1028         /*
1029         * Any Rejected CIs must be in exactly the same order that we sent.
1030         * Check packet length and CI length at each step.
1031         * If we find any deviations, then this packet is bad.
1032         */
1033 #define REJCIVOID(opt, neg) \
1034         if (go->neg && \
1035                         len >= CILEN_VOID && \
1036                         p[1] == CILEN_VOID && \
1037                         p[0] == opt) { \
1038                 len -= CILEN_VOID; \
1039                 INCPTR(CILEN_VOID, p); \
1040                 try.neg = 0; \
1041                 LCPDEBUG((LOG_INFO, "lcp_rejci: void opt %d rejected\n", opt)); \
1042         }
1043 #define REJCISHORT(opt, neg, val) \
1044         if (go->neg && \
1045                         len >= CILEN_SHORT && \
1046                         p[1] == CILEN_SHORT && \
1047                         p[0] == opt) { \
1048                 len -= CILEN_SHORT; \
1049                 INCPTR(2, p); \
1050                 GETSHORT(cishort, p); \
1051                 /* Check rejected value. */ \
1052                 if (cishort != val) \
1053                         goto bad; \
1054                 try.neg = 0; \
1055                 LCPDEBUG((LOG_INFO,"lcp_rejci: short opt %d rejected\n", opt)); \
1056         }
1057 #define REJCICHAP(opt, neg, val, digest) \
1058         if (go->neg && \
1059                         len >= CILEN_CHAP && \
1060                         p[1] == CILEN_CHAP && \
1061                         p[0] == opt) { \
1062                 len -= CILEN_CHAP; \
1063                 INCPTR(2, p); \
1064                 GETSHORT(cishort, p); \
1065                 GETCHAR(cichar, p); \
1066                 /* Check rejected value. */ \
1067                 if (cishort != val || cichar != digest) \
1068                         goto bad; \
1069                 try.neg = 0; \
1070                 try.neg_upap = 0; \
1071                 LCPDEBUG((LOG_INFO,"lcp_rejci: chap opt %d rejected\n", opt)); \
1072         }
1073 #define REJCILONG(opt, neg, val) \
1074         if (go->neg && \
1075                         len >= CILEN_LONG && \
1076                         p[1] == CILEN_LONG && \
1077                         p[0] == opt) { \
1078                 len -= CILEN_LONG; \
1079                 INCPTR(2, p); \
1080                 GETLONG(cilong, p); \
1081                 /* Check rejected value. */ \
1082                 if (cilong != val) \
1083                         goto bad; \
1084                 try.neg = 0; \
1085                 LCPDEBUG((LOG_INFO,"lcp_rejci: long opt %d rejected\n", opt)); \
1086         }
1087 #define REJCILQR(opt, neg, val) \
1088         if (go->neg && \
1089                         len >= CILEN_LQR && \
1090                         p[1] == CILEN_LQR && \
1091                         p[0] == opt) { \
1092                 len -= CILEN_LQR; \
1093                 INCPTR(2, p); \
1094                 GETSHORT(cishort, p); \
1095                 GETLONG(cilong, p); \
1096                 /* Check rejected value. */ \
1097                 if (cishort != PPP_LQR || cilong != val) \
1098                         goto bad; \
1099                 try.neg = 0; \
1100                 LCPDEBUG((LOG_INFO,"lcp_rejci: LQR opt %d rejected\n", opt)); \
1101         }
1102 #define REJCICBCP(opt, neg, val) \
1103         if (go->neg && \
1104                         len >= CILEN_CBCP && \
1105                         p[1] == CILEN_CBCP && \
1106                         p[0] == opt) { \
1107                 len -= CILEN_CBCP; \
1108                 INCPTR(2, p); \
1109                 GETCHAR(cichar, p); \
1110                 /* Check rejected value. */ \
1111                 if (cichar != val) \
1112                         goto bad; \
1113                 try.neg = 0; \
1114                 LCPDEBUG((LOG_INFO,"lcp_rejci: Callback opt %d rejected\n", opt)); \
1115         }
1116
1117         REJCISHORT(CI_MRU, neg_mru, go->mru);
1118         REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
1119         REJCICHAP(CI_AUTHTYPE, neg_chap, PPP_CHAP, go->chap_mdtype);
1120         if (!go->neg_chap) {
1121                 REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
1122         }
1123         REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
1124         REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
1125         REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
1126         REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
1127         REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
1128
1129         /*
1130         * If there are any remaining CIs, then this packet is bad.
1131         */
1132         if (len != 0)
1133                 goto bad;
1134         /*
1135         * Now we can update state.
1136         */
1137         if (f->state != OPENED)
1138                 *go = try;
1139         return 1;
1140
1141 bad:
1142         LCPDEBUG((LOG_WARNING, "lcp_rejci: received bad Reject!\n"));
1143         return 0;
1144 }
1145
1146
1147 /*
1148  * lcp_reqci - Check the peer's requested CIs and send appropriate response.
1149  *
1150  * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
1151  * appropriately.  If reject_if_disagree is non-zero, doesn't return
1152  * CONFNAK; returns CONFREJ if it can't return CONFACK.
1153  */
1154 static int lcp_reqci(fsm *f,
1155                                                 u_char *inp,            /* Requested CIs */
1156                                                 int *lenp,                      /* Length of requested CIs */
1157                                                 int reject_if_disagree)
1158 {
1159         lcp_options *go = &lcp_gotoptions[f->unit];
1160         lcp_options *ho = &lcp_hisoptions[f->unit];
1161         lcp_options *ao = &lcp_allowoptions[f->unit];
1162         u_char *cip, *next;                     /* Pointer to current and next CIs */
1163         int cilen, citype, cichar;      /* Parsed len, type, char value */
1164         u_short cishort;                        /* Parsed short value */
1165         u32_t cilong;                   /* Parse long value */
1166         int rc = CONFACK;                       /* Final packet return code */
1167         int orc;                                        /* Individual option return code */
1168         u_char *p;                                      /* Pointer to next char to parse */
1169         u_char *rejp;                           /* Pointer to next char in reject frame */
1170         u_char *nakp;                           /* Pointer to next char in Nak frame */
1171         int l = *lenp;                          /* Length left */
1172 #if TRACELCP > 0
1173         char traceBuf[80];
1174         int traceNdx = 0;
1175 #endif
1176
1177         /*
1178          * Reset all his options.
1179          */
1180         BZERO(ho, sizeof(*ho));
1181
1182         /*
1183          * Process all his options.
1184          */
1185         next = inp;
1186         nakp = nak_buffer;
1187         rejp = inp;
1188         while (l) {
1189                 orc = CONFACK;                  /* Assume success */
1190                 cip = p = next;                 /* Remember begining of CI */
1191                 if (l < 2 ||                    /* Not enough data for CI header or */
1192                                 p[1] < 2 ||                     /*  CI length too small or */
1193                                 p[1] > l) {                     /*  CI length too big? */
1194                         LCPDEBUG((LOG_WARNING, "lcp_reqci: bad CI length!\n"));
1195                         orc = CONFREJ;          /* Reject bad CI */
1196                         cilen = l;                      /* Reject till end of packet */
1197                         l = 0;                  /* Don't loop again */
1198                         citype = 0;
1199                         goto endswitch;
1200                 }
1201                 GETCHAR(citype, p);             /* Parse CI type */
1202                 GETCHAR(cilen, p);              /* Parse CI length */
1203                 l -= cilen;                     /* Adjust remaining length */
1204                 next += cilen;                  /* Step to next CI */
1205
1206                 switch (citype) {               /* Check CI type */
1207                 case CI_MRU:
1208                         if (!ao->neg_mru) {             /* Allow option? */
1209                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject MRU - not allowed\n"));
1210                                 orc = CONFREJ;          /* Reject CI */
1211                                 break;
1212                         } else if (cilen != CILEN_SHORT) {      /* Check CI length */
1213                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject MRU - bad length\n"));
1214                                 orc = CONFREJ;          /* Reject CI */
1215                                 break;
1216                         }
1217                         GETSHORT(cishort, p);   /* Parse MRU */
1218
1219                         /*
1220                          * He must be able to receive at least our minimum.
1221                          * No need to check a maximum.  If he sends a large number,
1222                          * we'll just ignore it.
1223                          */
1224                         if (cishort < PPP_MINMRU) {
1225                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Nak - MRU too small\n"));
1226                                 orc = CONFNAK;          /* Nak CI */
1227                                 PUTCHAR(CI_MRU, nakp);
1228                                 PUTCHAR(CILEN_SHORT, nakp);
1229                                 PUTSHORT(PPP_MINMRU, nakp);     /* Give him a hint */
1230                                 break;
1231                         }
1232                         ho->neg_mru = 1;                /* Remember he sent MRU */
1233                         ho->mru = cishort;              /* And remember value */
1234 #if TRACELCP > 0
1235                         sprintf(&traceBuf[traceNdx], " MRU %d", cishort);
1236                         traceNdx = strlen(traceBuf);
1237 #endif
1238                         break;
1239
1240                 case CI_ASYNCMAP:
1241                         if (!ao->neg_asyncmap) {
1242                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject ASYNCMAP not allowed\n"));
1243                                 orc = CONFREJ;
1244                                 break;
1245                         } else if (cilen != CILEN_LONG) {
1246                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject ASYNCMAP bad length\n"));
1247                                 orc = CONFREJ;
1248                                 break;
1249                         }
1250                         GETLONG(cilong, p);
1251
1252                         /*
1253                          * Asyncmap must have set at least the bits
1254                          * which are set in lcp_allowoptions[unit].asyncmap.
1255                          */
1256                         if ((ao->asyncmap & ~cilong) != 0) {
1257                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Nak ASYNCMAP %lX missing %lX\n",
1258                                                         cilong, ao->asyncmap));
1259                                 orc = CONFNAK;
1260                                 PUTCHAR(CI_ASYNCMAP, nakp);
1261                                 PUTCHAR(CILEN_LONG, nakp);
1262                                 PUTLONG(ao->asyncmap | cilong, nakp);
1263                                 break;
1264                         }
1265                         ho->neg_asyncmap = 1;
1266                         ho->asyncmap = cilong;
1267 #if TRACELCP > 0
1268                         sprintf(&traceBuf[traceNdx], " ASYNCMAP=%lX", cilong);
1269                         traceNdx = strlen(traceBuf);
1270 #endif
1271                         break;
1272
1273                 case CI_AUTHTYPE:
1274                         if (cilen < CILEN_SHORT) {
1275                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject AUTHTYPE missing arg\n"));
1276                                 orc = CONFREJ;
1277                                 break;
1278                         } else if (!(ao->neg_upap || ao->neg_chap)) {
1279                                 /*
1280                                  * Reject the option if we're not willing to authenticate.
1281                                  */
1282                                 LCPDEBUG((LOG_INFO, "lcp_reqci: Reject AUTHTYPE not allowed\n"));
1283                                 orc = CONFREJ;
1284                                 break;
1285                         }
1286                         GETSHORT(cishort, p);
1287
1288                         /*
1289                          * Authtype must be UPAP or CHAP.
1290                          *
1291                          * Note: if both ao->neg_upap and ao->neg_chap are set,
1292                          * and the peer sends a Configure-Request with two
1293                          * authenticate-protocol requests, one for CHAP and one
1294                          * for UPAP, then we will reject the second request.
1295                          * Whether we end up doing CHAP or UPAP depends then on
1296                          * the ordering of the CIs in the peer's Configure-Request.
1297                          */
1298
1299                         if (cishort == PPP_PAP) {
1300                                 if (ho->neg_chap) {     /* we've already accepted CHAP */
1301                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE PAP already accepted\n"));
1302                                         orc = CONFREJ;
1303                                         break;
1304                                 } else if (cilen != CILEN_SHORT) {
1305                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE PAP bad len\n"));
1306                                         orc = CONFREJ;
1307                                         break;
1308                                 }
1309                                 if (!ao->neg_upap) {    /* we don't want to do PAP */
1310                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE PAP not allowed\n"));
1311                                         orc = CONFNAK;  /* NAK it and suggest CHAP */
1312                                         PUTCHAR(CI_AUTHTYPE, nakp);
1313                                         PUTCHAR(CILEN_CHAP, nakp);
1314                                         PUTSHORT(PPP_CHAP, nakp);
1315                                         PUTCHAR(ao->chap_mdtype, nakp);
1316                                         break;
1317                                 }
1318                                 ho->neg_upap = 1;
1319 #if TRACELCP > 0
1320                                 sprintf(&traceBuf[traceNdx], " PAP (%X)", cishort);
1321                                 traceNdx = strlen(traceBuf);
1322 #endif
1323                                 break;
1324                         }
1325                         if (cishort == PPP_CHAP) {
1326                                 if (ho->neg_upap) {     /* we've already accepted PAP */
1327                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE CHAP accepted PAP\n"));
1328                                         orc = CONFREJ;
1329                                         break;
1330                                 } else if (cilen != CILEN_CHAP) {
1331                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE CHAP bad len\n"));
1332                                         orc = CONFREJ;
1333                                         break;
1334                                 }
1335                                 if (!ao->neg_chap) {    /* we don't want to do CHAP */
1336                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE CHAP not allowed\n"));
1337                                         orc = CONFNAK;  /* NAK it and suggest PAP */
1338                                         PUTCHAR(CI_AUTHTYPE, nakp);
1339                                         PUTCHAR(CILEN_SHORT, nakp);
1340                                         PUTSHORT(PPP_PAP, nakp);
1341                                         break;
1342                                 }
1343                                 GETCHAR(cichar, p);     /* get digest type*/
1344                                 if (cichar != CHAP_DIGEST_MD5
1345 #ifdef CHAPMS
1346                                                 && cichar != CHAP_MICROSOFT
1347 #endif
1348                                 ) {
1349                                         LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE CHAP digest=%d\n", cichar));
1350                                         orc = CONFNAK;
1351                                         PUTCHAR(CI_AUTHTYPE, nakp);
1352                                         PUTCHAR(CILEN_CHAP, nakp);
1353                                         PUTSHORT(PPP_CHAP, nakp);
1354                                         PUTCHAR(ao->chap_mdtype, nakp);
1355                                         break;
1356                                 }
1357 #if TRACELCP > 0
1358                                 sprintf(&traceBuf[traceNdx], " CHAP %X,%d", cishort, cichar);
1359                                 traceNdx = strlen(traceBuf);
1360 #endif
1361                                 ho->chap_mdtype = cichar; /* save md type */
1362                                 ho->neg_chap = 1;
1363                                 break;
1364                         }
1365
1366                         /*
1367                          * We don't recognize the protocol they're asking for.
1368                          * Nak it with something we're willing to do.
1369                          * (At this point we know ao->neg_upap || ao->neg_chap.)
1370                          */
1371                         orc = CONFNAK;
1372                         PUTCHAR(CI_AUTHTYPE, nakp);
1373                         if (ao->neg_chap) {
1374                                 LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE %d req CHAP\n", cishort));
1375                                 PUTCHAR(CILEN_CHAP, nakp);
1376                                 PUTSHORT(PPP_CHAP, nakp);
1377                                 PUTCHAR(ao->chap_mdtype, nakp);
1378                         }
1379                         else {
1380                                 LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE %d req PAP\n", cishort));
1381                                 PUTCHAR(CILEN_SHORT, nakp);
1382                                 PUTSHORT(PPP_PAP, nakp);
1383                         }
1384                         break;
1385
1386                 case CI_QUALITY:
1387                         GETSHORT(cishort, p);
1388                         GETLONG(cilong, p);
1389 #if TRACELCP > 0
1390                         sprintf(&traceBuf[traceNdx], " QUALITY (%x %x)", cishort, (unsigned int) cilong);
1391                         traceNdx = strlen(traceBuf);
1392 #endif
1393
1394                         if (!ao->neg_lqr ||
1395                                         cilen != CILEN_LQR) {
1396                                 orc = CONFREJ;
1397                                 break;
1398                         }
1399
1400                         /*
1401                          * Check the protocol and the reporting period.
1402                          * XXX When should we Nak this, and what with?
1403                          */
1404                         if (cishort != PPP_LQR) {
1405                                 orc = CONFNAK;
1406                                 PUTCHAR(CI_QUALITY, nakp);
1407                                 PUTCHAR(CILEN_LQR, nakp);
1408                                 PUTSHORT(PPP_LQR, nakp);
1409                                 PUTLONG(ao->lqr_period, nakp);
1410                                 break;
1411                         }
1412                         break;
1413
1414                 case CI_MAGICNUMBER:
1415                         if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
1416                                         cilen != CILEN_LONG) {
1417                                 orc = CONFREJ;
1418                                 break;
1419                         }
1420                         GETLONG(cilong, p);
1421 #if TRACELCP > 0
1422                         sprintf(&traceBuf[traceNdx], " MAGICNUMBER (%lX)", cilong);
1423                         traceNdx = strlen(traceBuf);
1424 #endif
1425
1426                         /*
1427                          * He must have a different magic number.
1428                          */
1429                         if (go->neg_magicnumber &&
1430                                         cilong == go->magicnumber) {
1431                                 cilong = magic();       /* Don't put magic() inside macro! */
1432                                 orc = CONFNAK;
1433                                 PUTCHAR(CI_MAGICNUMBER, nakp);
1434                                 PUTCHAR(CILEN_LONG, nakp);
1435                                 PUTLONG(cilong, nakp);
1436                                 break;
1437                         }
1438                         ho->neg_magicnumber = 1;
1439                         ho->magicnumber = cilong;
1440                         break;
1441
1442
1443                 case CI_PCOMPRESSION:
1444 #if TRACELCP > 0
1445                         sprintf(&traceBuf[traceNdx], " PCOMPRESSION");
1446                         traceNdx = strlen(traceBuf);
1447 #endif
1448                         if (!ao->neg_pcompression ||
1449                                         cilen != CILEN_VOID) {
1450                                 orc = CONFREJ;
1451                                 break;
1452                         }
1453                         ho->neg_pcompression = 1;
1454                         break;
1455
1456                 case CI_ACCOMPRESSION:
1457 #if TRACELCP > 0
1458                         sprintf(&traceBuf[traceNdx], " ACCOMPRESSION");
1459                         traceNdx = strlen(traceBuf);
1460 #endif
1461                         if (!ao->neg_accompression ||
1462                                         cilen != CILEN_VOID) {
1463                                 orc = CONFREJ;
1464                                 break;
1465                         }
1466                         ho->neg_accompression = 1;
1467                         break;
1468
1469                 case CI_MRRU:
1470 #if TRACELCP > 0
1471                         sprintf(&traceBuf[traceNdx], " CI_MRRU");
1472                         traceNdx = strlen(traceBuf);
1473 #endif
1474                         orc = CONFREJ;
1475                         break;
1476
1477                 case CI_SSNHF:
1478 #if TRACELCP > 0
1479                         sprintf(&traceBuf[traceNdx], " CI_SSNHF");
1480                         traceNdx = strlen(traceBuf);
1481 #endif
1482                         orc = CONFREJ;
1483                         break;
1484
1485                 case CI_EPDISC:
1486 #if TRACELCP > 0
1487                         sprintf(&traceBuf[traceNdx], " CI_EPDISC");
1488                         traceNdx = strlen(traceBuf);
1489 #endif
1490                         orc = CONFREJ;
1491                         break;
1492
1493                 default:
1494 #if TRACELCP
1495                         sprintf(&traceBuf[traceNdx], " unknown %d", citype);
1496                         traceNdx = strlen(traceBuf);
1497 #endif
1498                         orc = CONFREJ;
1499                         break;
1500                 }
1501
1502         endswitch:
1503 #if TRACELCP
1504                 if (traceNdx >= 80 - 32) {
1505                         LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd%s\n", traceBuf));
1506                         traceNdx = 0;
1507                 }
1508 #endif
1509                 if (orc == CONFACK &&           /* Good CI */
1510                                 rc != CONFACK)          /*  but prior CI wasnt? */
1511                         continue;                       /* Don't send this one */
1512
1513                 if (orc == CONFNAK) {           /* Nak this CI? */
1514                         if (reject_if_disagree  /* Getting fed up with sending NAKs? */
1515                                         && citype != CI_MAGICNUMBER) {
1516                                 orc = CONFREJ;          /* Get tough if so */
1517                         }
1518                         else {
1519                                 if (rc == CONFREJ)      /* Rejecting prior CI? */
1520                                         continue;               /* Don't send this one */
1521                                 rc = CONFNAK;
1522                         }
1523                 }
1524                 if (orc == CONFREJ) {           /* Reject this CI */
1525                         rc = CONFREJ;
1526                         if (cip != rejp)                /* Need to move rejected CI? */
1527                                 BCOPY(cip, rejp, cilen); /* Move it */
1528                         INCPTR(cilen, rejp);    /* Update output pointer */
1529                 }
1530         }
1531
1532         /*
1533          * If we wanted to send additional NAKs (for unsent CIs), the
1534          * code would go here.  The extra NAKs would go at *nakp.
1535          * At present there are no cases where we want to ask the
1536          * peer to negotiate an option.
1537          */
1538
1539         switch (rc) {
1540         case CONFACK:
1541                 *lenp = (int)(next - inp);
1542                 break;
1543         case CONFNAK:
1544                 /*
1545                  * Copy the Nak'd options from the nak_buffer to the caller's buffer.
1546                  */
1547                 *lenp = (int)(nakp - nak_buffer);
1548                 BCOPY(nak_buffer, inp, *lenp);
1549                 break;
1550         case CONFREJ:
1551                 *lenp = (int)(rejp - inp);
1552                 break;
1553         }
1554
1555 #if TRACELCP > 0
1556         if (traceNdx > 0) {
1557                 LCPDEBUG((LOG_INFO, "lcp_reqci: %s\n", traceBuf));
1558         }
1559 #endif
1560         LCPDEBUG((LOG_INFO, "lcp_reqci: returning CONF%s.\n", CODENAME(rc)));
1561         return (rc);                    /* Return final code */
1562 }
1563
1564
1565 /*
1566  * lcp_up - LCP has come UP.
1567  */
1568 static void lcp_up(fsm *f)
1569 {
1570         lcp_options *wo = &lcp_wantoptions[f->unit];
1571         lcp_options *ho = &lcp_hisoptions[f->unit];
1572         lcp_options *go = &lcp_gotoptions[f->unit];
1573         lcp_options *ao = &lcp_allowoptions[f->unit];
1574
1575         if (!go->neg_magicnumber)
1576                 go->magicnumber = 0;
1577         if (!ho->neg_magicnumber)
1578                 ho->magicnumber = 0;
1579
1580         /*
1581         * Set our MTU to the smaller of the MTU we wanted and
1582         * the MRU our peer wanted.  If we negotiated an MRU,
1583         * set our MRU to the larger of value we wanted and
1584         * the value we got in the negotiation.
1585         */
1586         ppp_send_config(f->unit, LWIP_MIN(ao->mru, (ho->neg_mru? ho->mru: PPP_MRU)),
1587                                 (ho->neg_asyncmap? ho->asyncmap: 0xffffffffl),
1588                                 ho->neg_pcompression, ho->neg_accompression);
1589         /*
1590         * If the asyncmap hasn't been negotiated, we really should
1591         * set the receive asyncmap to ffffffff, but we set it to 0
1592         * for backwards contemptibility.
1593         */
1594         ppp_recv_config(f->unit, (go->neg_mru? LWIP_MAX(wo->mru, go->mru): PPP_MRU),
1595                                 (go->neg_asyncmap? go->asyncmap: 0x00000000),
1596                                 go->neg_pcompression, go->neg_accompression);
1597
1598         if (ho->neg_mru)
1599                 peer_mru[f->unit] = ho->mru;
1600
1601         lcp_echo_lowerup(f->unit);  /* Enable echo messages */
1602
1603         link_established(f->unit);
1604 }
1605
1606
1607 /*
1608  * lcp_down - LCP has gone DOWN.
1609  *
1610  * Alert other protocols.
1611  */
1612 static void lcp_down(fsm *f)
1613 {
1614         lcp_options *go = &lcp_gotoptions[f->unit];
1615
1616         lcp_echo_lowerdown(f->unit);
1617
1618         link_down(f->unit);
1619
1620         ppp_send_config(f->unit, PPP_MRU, 0xffffffffl, 0, 0);
1621         ppp_recv_config(f->unit, PPP_MRU,
1622                                 (go->neg_asyncmap? go->asyncmap: 0x00000000),
1623                                 go->neg_pcompression, go->neg_accompression);
1624         peer_mru[f->unit] = PPP_MRU;
1625 }
1626
1627
1628 /*
1629  * lcp_starting - LCP needs the lower layer up.
1630  */
1631 static void lcp_starting(fsm *f)
1632 {
1633         link_required(f->unit);
1634 }
1635
1636
1637 /*
1638  * lcp_finished - LCP has finished with the lower layer.
1639  */
1640 static void lcp_finished(fsm *f)
1641 {
1642         link_terminated(f->unit);
1643 }
1644
1645
1646 #if 0
1647 /*
1648  * print_string - print a readable representation of a string using
1649  * printer.
1650  */
1651 static void print_string(
1652     char *p,
1653     int len,
1654     void (*printer) (void *, char *, ...),
1655     void *arg
1656 )
1657 {
1658     int c;
1659
1660     printer(arg, "\"");
1661     for (; len > 0; --len) {
1662         c = *p++;
1663         if (' ' <= c && c <= '~') {
1664             if (c == '\\' || c == '"')
1665                 printer(arg, "\\");
1666             printer(arg, "%c", c);
1667         } else {
1668             switch (c) {
1669             case '\n':
1670                 printer(arg, "\\n");
1671                 break;
1672             case '\r':
1673                 printer(arg, "\\r");
1674                 break;
1675             case '\t':
1676                 printer(arg, "\\t");
1677                 break;
1678             default:
1679                 printer(arg, "\\%.3o", c);
1680             }
1681         }
1682     }
1683     printer(arg, "\"");
1684 }
1685
1686
1687 /*
1688  * lcp_printpkt - print the contents of an LCP packet.
1689  */
1690 static char *lcp_codenames[] = {
1691         "ConfReq", "ConfAck", "ConfNak", "ConfRej",
1692         "TermReq", "TermAck", "CodeRej", "ProtRej",
1693         "EchoReq", "EchoRep", "DiscReq"
1694 };
1695
1696 static int lcp_printpkt(
1697         u_char *p,
1698         int plen,
1699         void (*printer) (void *, char *, ...),
1700         void *arg
1701 )
1702 {
1703         int code, id, len, olen;
1704         u_char *pstart, *optend;
1705         u_short cishort;
1706         u32_t cilong;
1707
1708         if (plen < HEADERLEN)
1709                 return 0;
1710         pstart = p;
1711         GETCHAR(code, p);
1712         GETCHAR(id, p);
1713         GETSHORT(len, p);
1714         if (len < HEADERLEN || len > plen)
1715                 return 0;
1716
1717         if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *))
1718                 printer(arg, " %s", lcp_codenames[code-1]);
1719         else
1720                 printer(arg, " code=0x%x", code);
1721         printer(arg, " id=0x%x", id);
1722         len -= HEADERLEN;
1723         switch (code) {
1724         case CONFREQ:
1725         case CONFACK:
1726         case CONFNAK:
1727         case CONFREJ:
1728                 /* print option list */
1729                 while (len >= 2) {
1730                         GETCHAR(code, p);
1731                         GETCHAR(olen, p);
1732                         p -= 2;
1733                         if (olen < 2 || olen > len) {
1734                                 break;
1735                         }
1736                         printer(arg, " <");
1737                         len -= olen;
1738                         optend = p + olen;
1739                         switch (code) {
1740                         case CI_MRU:
1741                                 if (olen == CILEN_SHORT) {
1742                                         p += 2;
1743                                         GETSHORT(cishort, p);
1744                                         printer(arg, "mru %d", cishort);
1745                                 }
1746                                 break;
1747                         case CI_ASYNCMAP:
1748                                 if (olen == CILEN_LONG) {
1749                                         p += 2;
1750                                         GETLONG(cilong, p);
1751                                         printer(arg, "asyncmap 0x%lx", cilong);
1752                                 }
1753                                 break;
1754                         case CI_AUTHTYPE:
1755                                 if (olen >= CILEN_SHORT) {
1756                                         p += 2;
1757                                         printer(arg, "auth ");
1758                                         GETSHORT(cishort, p);
1759                                         switch (cishort) {
1760                                         case PPP_PAP:
1761                                                 printer(arg, "pap");
1762                                                 break;
1763                                         case PPP_CHAP:
1764                                                 printer(arg, "chap");
1765                                                 break;
1766                                         default:
1767                                                 printer(arg, "0x%x", cishort);
1768                                         }
1769                                 }
1770                                 break;
1771                         case CI_QUALITY:
1772                                 if (olen >= CILEN_SHORT) {
1773                                         p += 2;
1774                                         printer(arg, "quality ");
1775                                         GETSHORT(cishort, p);
1776                                         switch (cishort) {
1777                                         case PPP_LQR:
1778                                                 printer(arg, "lqr");
1779                                                 break;
1780                                         default:
1781                                                 printer(arg, "0x%x", cishort);
1782                                         }
1783                                 }
1784                                 break;
1785                         case CI_CALLBACK:
1786                                 if (olen >= CILEN_CHAR) {
1787                                         p += 2;
1788                                         printer(arg, "callback ");
1789                                         GETSHORT(cishort, p);
1790                                         switch (cishort) {
1791                                         case CBCP_OPT:
1792                                                 printer(arg, "CBCP");
1793                                                 break;
1794                                         default:
1795                                                 printer(arg, "0x%x", cishort);
1796                                         }
1797                                 }
1798                                 break;
1799                         case CI_MAGICNUMBER:
1800                                 if (olen == CILEN_LONG) {
1801                                         p += 2;
1802                                         GETLONG(cilong, p);
1803                                         printer(arg, "magic 0x%x", cilong);
1804                                 }
1805                                 break;
1806                         case CI_PCOMPRESSION:
1807                                 if (olen == CILEN_VOID) {
1808                                         p += 2;
1809                                         printer(arg, "pcomp");
1810                                 }
1811                                 break;
1812                         case CI_ACCOMPRESSION:
1813                                 if (olen == CILEN_VOID) {
1814                                         p += 2;
1815                                         printer(arg, "accomp");
1816                                 }
1817                                 break;
1818                         }
1819                         while (p < optend) {
1820                                 GETCHAR(code, p);
1821                                 printer(arg, " %.2x", code);
1822                         }
1823                         printer(arg, ">");
1824                 }
1825                 break;
1826
1827         case TERMACK:
1828         case TERMREQ:
1829                 if (len > 0 && *p >= ' ' && *p < 0x7f) {
1830                         printer(arg, " ");
1831                         print_string((char*)p, len, printer, arg);
1832                         p += len;
1833                         len = 0;
1834                 }
1835                 break;
1836
1837         case ECHOREQ:
1838         case ECHOREP:
1839         case DISCREQ:
1840                 if (len >= 4) {
1841                         GETLONG(cilong, p);
1842                         printer(arg, " magic=0x%x", cilong);
1843                         p += 4;
1844                         len -= 4;
1845                 }
1846                 break;
1847         }
1848
1849         /* print the rest of the bytes in the packet */
1850         for (; len > 0; --len) {
1851                 GETCHAR(code, p);
1852                 printer(arg, " %.2x", code);
1853         }
1854
1855         return (int)(p - pstart);
1856 }
1857 #endif
1858
1859 /*
1860  * Time to shut down the link because there is nothing out there.
1861  */
1862
1863 static void LcpLinkFailure (fsm *f)
1864 {
1865         if (f->state == OPENED) {
1866                 LCPDEBUG((LOG_INFO, "No response to %d echo-requests\n", lcp_echos_pending));
1867                 LCPDEBUG((LOG_NOTICE, "Serial link appears to be disconnected.\n"));
1868                 lcp_close(f->unit, "Peer not responding");
1869         }
1870 }
1871
1872 /*
1873  * Timer expired for the LCP echo requests from this process.
1874  */
1875
1876 static void LcpEchoCheck (fsm *f)
1877 {
1878         LcpSendEchoRequest (f);
1879
1880         /*
1881          * Start the timer for the next interval.
1882          */
1883         LWIP_ASSERT("lcp_echo_timer_running == 0", lcp_echo_timer_running == 0);
1884
1885         TIMEOUT (LcpEchoTimeout, f, lcp_echo_interval);
1886         lcp_echo_timer_running = 1;
1887 }
1888
1889 /*
1890  * LcpEchoTimeout - Timer expired on the LCP echo
1891  */
1892
1893 static void LcpEchoTimeout (void *arg)
1894 {
1895         if (lcp_echo_timer_running != 0) {
1896                 lcp_echo_timer_running = 0;
1897                 LcpEchoCheck ((fsm *) arg);
1898         }
1899 }
1900
1901 /*
1902  * LcpEchoReply - LCP has received a reply to the echo
1903  */
1904 static void lcp_received_echo_reply (fsm *f, int id, u_char *inp, int len)
1905 {
1906         u32_t magic;
1907
1908         (void)id;
1909
1910         /* Check the magic number - don't count replies from ourselves. */
1911         if (len < 4) {
1912                 LCPDEBUG((LOG_WARNING, "lcp: received short Echo-Reply, length %d\n", len));
1913                 return;
1914         }
1915         GETLONG(magic, inp);
1916         if (lcp_gotoptions[f->unit].neg_magicnumber
1917                         && magic == lcp_gotoptions[f->unit].magicnumber) {
1918                 LCPDEBUG((LOG_WARNING, "appear to have received our own echo-reply!\n"));
1919                 return;
1920         }
1921
1922         /* Reset the number of outstanding echo frames */
1923         lcp_echos_pending = 0;
1924 }
1925
1926 /*
1927  * LcpSendEchoRequest - Send an echo request frame to the peer
1928  */
1929
1930 static void LcpSendEchoRequest (fsm *f)
1931 {
1932         u32_t lcp_magic;
1933         u_char pkt[4], *pktp;
1934
1935         /*
1936         * Detect the failure of the peer at this point.
1937         */
1938         if (lcp_echo_fails != 0) {
1939                 if (lcp_echos_pending++ >= lcp_echo_fails) {
1940                         LcpLinkFailure(f);
1941                         lcp_echos_pending = 0;
1942                 }
1943         }
1944
1945         /*
1946         * Make and send the echo request frame.
1947         */
1948         if (f->state == OPENED) {
1949                 lcp_magic = lcp_gotoptions[f->unit].magicnumber;
1950                 pktp = pkt;
1951                 PUTLONG(lcp_magic, pktp);
1952                 fsm_sdata(f, ECHOREQ, (u_char)(lcp_echo_number++ & 0xFF), pkt, (int)(pktp - pkt));
1953         }
1954 }
1955
1956 /*
1957  * lcp_echo_lowerup - Start the timer for the LCP frame
1958  */
1959
1960 static void lcp_echo_lowerup (int unit)
1961 {
1962         fsm *f = &lcp_fsm[unit];
1963
1964         /* Clear the parameters for generating echo frames */
1965         lcp_echos_pending      = 0;
1966         lcp_echo_number        = 0;
1967         lcp_echo_timer_running = 0;
1968
1969         /* If a timeout interval is specified then start the timer */
1970         if (lcp_echo_interval != 0)
1971                 LcpEchoCheck (f);
1972 }
1973
1974 /*
1975  * lcp_echo_lowerdown - Stop the timer for the LCP frame
1976  */
1977
1978 static void lcp_echo_lowerdown (int unit)
1979 {
1980         fsm *f = &lcp_fsm[unit];
1981
1982         if (lcp_echo_timer_running != 0) {
1983                 UNTIMEOUT (LcpEchoTimeout, f);
1984                 lcp_echo_timer_running = 0;
1985         }
1986 }
1987
1988 #endif /* PPP_SUPPORT */