lib/drivers/lwip/src/netif/ppp/ipcp.c

   1 /*****************************************************************************
   2 * ipcp.c - Network PPP IP 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 * 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
  31 *   Original.
  32 *****************************************************************************/
  33 /*
  34  * ipcp.c - PPP IP Control Protocol.
  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 #include "lwip/opt.h"
  53
  54 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
  55
  56 #include "ppp.h"
  57 #include "pppdebug.h"
  58
  59 #include "auth.h"
  60 #include "fsm.h"
  61 #include "vj.h"
  62 #include "ipcp.h"
  63
  64 #include <string.h>
  65
  66 /*************************/
  67 /*** LOCAL DEFINITIONS ***/
  68 /*************************/
  69 /* #define OLD_CI_ADDRS 1 */ /* Support deprecated address negotiation. */
  70
  71 /*
  72  * Lengths of configuration options.
  73  */
  74 #define CILEN_VOID     2
  75 #define CILEN_COMPRESS 4  /* min length for compression protocol opt. */
  76 #define CILEN_VJ       6  /* length for RFC1332 Van-Jacobson opt. */
  77 #define CILEN_ADDR     6  /* new-style single address option */
  78 #define CILEN_ADDRS    10 /* old-style dual address option */
  79
  80
  81
  82 /***********************************/
  83 /*** LOCAL FUNCTION DECLARATIONS ***/
  84 /***********************************/
  85 /*
  86  * Callbacks for fsm code.  (CI = Configuration Information)
  87  */
  88 static void ipcp_resetci (fsm *);                     /* Reset our CI */
  89 static int  ipcp_cilen (fsm *);                       /* Return length of our CI */
  90 static void ipcp_addci (fsm *, u_char *, int *);      /* Add our CI */
  91 static int  ipcp_ackci (fsm *, u_char *, int);        /* Peer ack'd our CI */
  92 static int  ipcp_nakci (fsm *, u_char *, int);        /* Peer nak'd our CI */
  93 static int  ipcp_rejci (fsm *, u_char *, int);        /* Peer rej'd our CI */
  94 static int  ipcp_reqci (fsm *, u_char *, int *, int); /* Rcv CI */
  95 static void ipcp_up (fsm *);                          /* We're UP */
  96 static void ipcp_down (fsm *);                        /* We're DOWN */
  97 #if 0
  98 static void ipcp_script (fsm *, char *); /* Run an up/down script */
  99 #endif
 100 static void ipcp_finished (fsm *);                    /* Don't need lower layer */
 101
 102 /*
 103  * Protocol entry points from main code.
 104  */
 105 static void ipcp_init (int);
 106 static void ipcp_open (int);
 107 static void ipcp_close (int, char *);
 108 static void ipcp_lowerup (int);
 109 static void ipcp_lowerdown (int);
 110 static void ipcp_input (int, u_char *, int);
 111 static void ipcp_protrej (int);
 112
 113 static void ipcp_clear_addrs (int);
 114
 115 #define CODENAME(x) ((x) == CONFACK ? "ACK" : \
 116                      (x) == CONFNAK ? "NAK" : "REJ")
 117
 118
 119
 120 /******************************/
 121 /*** PUBLIC DATA STRUCTURES ***/
 122 /******************************/
 123 /* global vars */
 124 ipcp_options ipcp_wantoptions[NUM_PPP];  /* Options that we want to request */
 125 ipcp_options ipcp_gotoptions[NUM_PPP];   /* Options that peer ack'd */
 126 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
 127 ipcp_options ipcp_hisoptions[NUM_PPP];   /* Options that we ack'd */
 128
 129 fsm ipcp_fsm[NUM_PPP]; /* IPCP fsm structure */
 130
 131 struct protent ipcp_protent = {
 132   PPP_IPCP,
 133   ipcp_init,
 134   ipcp_input,
 135   ipcp_protrej,
 136   ipcp_lowerup,
 137   ipcp_lowerdown,
 138   ipcp_open,
 139   ipcp_close,
 140 #if 0
 141   ipcp_printpkt,
 142   NULL,
 143 #endif
 144   1,
 145   "IPCP",
 146 #if 0
 147   ip_check_options,
 148   NULL,
 149   ip_active_pkt
 150 #endif
 151 };
 152
 153
 154
 155 /*****************************/
 156 /*** LOCAL DATA STRUCTURES ***/
 157 /*****************************/
 158 /* local vars */
 159 static int cis_received[NUM_PPP];      /* # Conf-Reqs received */
 160 static int default_route_set[NUM_PPP]; /* Have set up a default route */
 161
 162 static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
 163   ipcp_resetci,  /* Reset our Configuration Information */
 164   ipcp_cilen,    /* Length of our Configuration Information */
 165   ipcp_addci,    /* Add our Configuration Information */
 166   ipcp_ackci,    /* ACK our Configuration Information */
 167   ipcp_nakci,    /* NAK our Configuration Information */
 168   ipcp_rejci,    /* Reject our Configuration Information */
 169   ipcp_reqci,    /* Request peer's Configuration Information */
 170   ipcp_up,       /* Called when fsm reaches LS_OPENED state */
 171   ipcp_down,     /* Called when fsm leaves LS_OPENED state */
 172   NULL,          /* Called when we want the lower layer up */
 173   ipcp_finished, /* Called when we want the lower layer down */
 174   NULL,          /* Called when Protocol-Reject received */
 175   NULL,          /* Retransmission is necessary */
 176   NULL,          /* Called to handle protocol-specific codes */
 177   "IPCP"         /* String name of protocol */
 178 };
 179
 180
 181
 182 /**********************************/
 183 /*** LOCAL FUNCTION DEFINITIONS ***/
 184 /**********************************/
 185
 186 #define inet_ntoa(addr) ip_ntoa(((struct ip_addr*)&(addr)))
 187
 188 /*
 189  * ipcp_init - Initialize IPCP.
 190  */
 191 static void
 192 ipcp_init(int unit)
 193 {
 194   fsm           *f = &ipcp_fsm[unit];
 195   ipcp_options *wo = &ipcp_wantoptions[unit];
 196   ipcp_options *ao = &ipcp_allowoptions[unit];
 197
 198   f->unit      = unit;
 199   f->protocol  = PPP_IPCP;
 200   f->callbacks = &ipcp_callbacks;
 201   fsm_init(&ipcp_fsm[unit]);
 202
 203   memset(wo, 0, sizeof(*wo));
 204   memset(ao, 0, sizeof(*ao));
 205
 206   wo->neg_addr      = 1;
 207   wo->ouraddr       = 0;
 208 #if VJ_SUPPORT
 209   wo->neg_vj        = 1;
 210 #else  /* VJ_SUPPORT */
 211   wo->neg_vj        = 0;
 212 #endif /* VJ_SUPPORT */
 213   wo->vj_protocol   = IPCP_VJ_COMP;
 214   wo->maxslotindex  = MAX_SLOTS - 1;
 215   wo->cflag         = 0;
 216   wo->default_route = 1;
 217
 218   ao->neg_addr      = 1;
 219 #if VJ_SUPPORT
 220   ao->neg_vj        = 1;
 221 #else  /* VJ_SUPPORT */
 222   ao->neg_vj        = 0;
 223 #endif /* VJ_SUPPORT */
 224   ao->maxslotindex  = MAX_SLOTS - 1;
 225   ao->cflag         = 1;
 226   ao->default_route = 1;
 227 }
 228
 229
 230 /*
 231  * ipcp_open - IPCP is allowed to come up.
 232  */
 233 static void
 234 ipcp_open(int unit)
 235 {
 236   fsm_open(&ipcp_fsm[unit]);
 237 }
 238
 239
 240 /*
 241  * ipcp_close - Take IPCP down.
 242  */
 243 static void
 244 ipcp_close(int unit, char *reason)
 245 {
 246   fsm_close(&ipcp_fsm[unit], reason);
 247 }
 248
 249
 250 /*
 251  * ipcp_lowerup - The lower layer is up.
 252  */
 253 static void
 254 ipcp_lowerup(int unit)
 255 {
 256   fsm_lowerup(&ipcp_fsm[unit]);
 257 }
 258
 259
 260 /*
 261  * ipcp_lowerdown - The lower layer is down.
 262  */
 263 static void
 264 ipcp_lowerdown(int unit)
 265 {
 266   fsm_lowerdown(&ipcp_fsm[unit]);
 267 }
 268
 269
 270 /*
 271  * ipcp_input - Input IPCP packet.
 272  */
 273 static void
 274 ipcp_input(int unit, u_char *p, int len)
 275 {
 276   fsm_input(&ipcp_fsm[unit], p, len);
 277 }
 278
 279
 280 /*
 281  * ipcp_protrej - A Protocol-Reject was received for IPCP.
 282  *
 283  * Pretend the lower layer went down, so we shut up.
 284  */
 285 static void
 286 ipcp_protrej(int unit)
 287 {
 288   fsm_lowerdown(&ipcp_fsm[unit]);
 289 }
 290
 291
 292 /*
 293  * ipcp_resetci - Reset our CI.
 294  */
 295 static void
 296 ipcp_resetci(fsm *f)
 297 {
 298   ipcp_options *wo = &ipcp_wantoptions[f->unit];
 299
 300   wo->req_addr = wo->neg_addr && ipcp_allowoptions[f->unit].neg_addr;
 301   if (wo->ouraddr == 0) {
 302     wo->accept_local = 1;
 303   }
 304   if (wo->hisaddr == 0) {
 305     wo->accept_remote = 1;
 306   }
 307   /* Request DNS addresses from the peer */
 308   wo->req_dns1 = ppp_settings.usepeerdns;
 309   wo->req_dns2 = ppp_settings.usepeerdns;
 310   ipcp_gotoptions[f->unit] = *wo;
 311   cis_received[f->unit] = 0;
 312 }
 313
 314
 315 /*
 316  * ipcp_cilen - Return length of our CI.
 317  */
 318 static int
 319 ipcp_cilen(fsm *f)
 320 {
 321   ipcp_options *go = &ipcp_gotoptions[f->unit];
 322   ipcp_options *wo = &ipcp_wantoptions[f->unit];
 323   ipcp_options *ho = &ipcp_hisoptions[f->unit];
 324
 325 #define LENCIVJ(neg, old)   (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
 326 #define LENCIADDR(neg, old) (neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0)
 327 #define LENCIDNS(neg)       (neg ? (CILEN_ADDR) : 0)
 328
 329   /*
 330    * First see if we want to change our options to the old
 331    * forms because we have received old forms from the peer.
 332    */
 333   if (wo->neg_addr && !go->neg_addr && !go->old_addrs) {
 334     /* use the old style of address negotiation */
 335     go->neg_addr = 1;
 336     go->old_addrs = 1;
 337   }
 338   if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
 339     /* try an older style of VJ negotiation */
 340     if (cis_received[f->unit] == 0) {
 341       /* keep trying the new style until we see some CI from the peer */
 342       go->neg_vj = 1;
 343     } else {
 344       /* use the old style only if the peer did */
 345       if (ho->neg_vj && ho->old_vj) {
 346         go->neg_vj = 1;
 347         go->old_vj = 1;
 348         go->vj_protocol = ho->vj_protocol;
 349       }
 350     }
 351   }
 352
 353   return (LENCIADDR(go->neg_addr, go->old_addrs) +
 354           LENCIVJ(go->neg_vj, go->old_vj) +
 355           LENCIDNS(go->req_dns1) +
 356           LENCIDNS(go->req_dns2));
 357 }
 358
 359
 360 /*
 361  * ipcp_addci - Add our desired CIs to a packet.
 362  */
 363 static void
 364 ipcp_addci(fsm *f, u_char *ucp, int *lenp)
 365 {
 366   ipcp_options *go = &ipcp_gotoptions[f->unit];
 367   int len = *lenp;
 368
 369 #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
 370   if (neg) { \
 371     int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
 372     if (len >= vjlen) { \
 373       PUTCHAR(opt, ucp); \
 374       PUTCHAR(vjlen, ucp); \
 375       PUTSHORT(val, ucp); \
 376       if (!old) { \
 377         PUTCHAR(maxslotindex, ucp); \
 378         PUTCHAR(cflag, ucp); \
 379       } \
 380       len -= vjlen; \
 381     } else { \
 382       neg = 0; \
 383     } \
 384   }
 385
 386 #define ADDCIADDR(opt, neg, old, val1, val2) \
 387   if (neg) { \
 388     int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
 389     if (len >= addrlen) { \
 390       u32_t l; \
 391       PUTCHAR(opt, ucp); \
 392       PUTCHAR(addrlen, ucp); \
 393       l = ntohl(val1); \
 394       PUTLONG(l, ucp); \
 395       if (old) { \
 396         l = ntohl(val2); \
 397         PUTLONG(l, ucp); \
 398       } \
 399       len -= addrlen; \
 400     } else { \
 401       neg = 0; \
 402     } \
 403   }
 404
 405 #define ADDCIDNS(opt, neg, addr) \
 406   if (neg) { \
 407     if (len >= CILEN_ADDR) { \
 408       u32_t l; \
 409       PUTCHAR(opt, ucp); \
 410       PUTCHAR(CILEN_ADDR, ucp); \
 411       l = ntohl(addr); \
 412       PUTLONG(l, ucp); \
 413       len -= CILEN_ADDR; \
 414     } else { \
 415       neg = 0; \
 416     } \
 417   }
 418
 419   ADDCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
 420       go->old_addrs, go->ouraddr, go->hisaddr);
 421
 422   ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
 423       go->maxslotindex, go->cflag);
 424
 425   ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
 426
 427   ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
 428
 429   *lenp -= len;
 430 }
 431
 432
 433 /*
 434  * ipcp_ackci - Ack our CIs.
 435  *
 436  * Returns:
 437  *  0 - Ack was bad.
 438  *  1 - Ack was good.
 439  */
 440 static int
 441 ipcp_ackci(fsm *f, u_char *p, int len)
 442 {
 443   ipcp_options *go = &ipcp_gotoptions[f->unit];
 444   u_short cilen, citype, cishort;
 445   u32_t cilong;
 446   u_char cimaxslotindex, cicflag;
 447
 448   /*
 449    * CIs must be in exactly the same order that we sent...
 450    * Check packet length and CI length at each step.
 451    * If we find any deviations, then this packet is bad.
 452    */
 453
 454 #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
 455   if (neg) { \
 456     int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
 457     if ((len -= vjlen) < 0) { \
 458       goto bad; \
 459     } \
 460     GETCHAR(citype, p); \
 461     GETCHAR(cilen, p); \
 462     if (cilen != vjlen || \
 463         citype != opt) { \
 464       goto bad; \
 465     } \
 466     GETSHORT(cishort, p); \
 467     if (cishort != val) { \
 468       goto bad; \
 469     } \
 470     if (!old) { \
 471       GETCHAR(cimaxslotindex, p); \
 472       if (cimaxslotindex != maxslotindex) { \
 473         goto bad; \
 474       } \
 475       GETCHAR(cicflag, p); \
 476       if (cicflag != cflag) { \
 477         goto bad; \
 478       } \
 479     } \
 480   }
 481
 482 #define ACKCIADDR(opt, neg, old, val1, val2) \
 483   if (neg) { \
 484     int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
 485     u32_t l; \
 486     if ((len -= addrlen) < 0) { \
 487       goto bad; \
 488     } \
 489     GETCHAR(citype, p); \
 490     GETCHAR(cilen, p); \
 491     if (cilen != addrlen || \
 492         citype != opt) { \
 493       goto bad; \
 494     } \
 495     GETLONG(l, p); \
 496     cilong = htonl(l); \
 497     if (val1 != cilong) { \
 498       goto bad; \
 499     } \
 500     if (old) { \
 501       GETLONG(l, p); \
 502       cilong = htonl(l); \
 503       if (val2 != cilong) { \
 504         goto bad; \
 505       } \
 506     } \
 507   }
 508
 509 #define ACKCIDNS(opt, neg, addr) \
 510   if (neg) { \
 511     u32_t l; \
 512     if ((len -= CILEN_ADDR) < 0) { \
 513       goto bad; \
 514     } \
 515     GETCHAR(citype, p); \
 516     GETCHAR(cilen, p); \
 517     if (cilen != CILEN_ADDR || \
 518         citype != opt) { \
 519       goto bad; \
 520     } \
 521     GETLONG(l, p); \
 522     cilong = htonl(l); \
 523     if (addr != cilong) { \
 524       goto bad; \
 525     } \
 526   }
 527
 528   ACKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
 529         go->old_addrs, go->ouraddr, go->hisaddr);
 530
 531   ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
 532       go->maxslotindex, go->cflag);
 533
 534   ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
 535
 536   ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
 537
 538   /*
 539    * If there are any remaining CIs, then this packet is bad.
 540    */
 541   if (len != 0) {
 542     goto bad;
 543   }
 544   return (1);
 545
 546 bad:
 547   IPCPDEBUG((LOG_INFO, "ipcp_ackci: received bad Ack!\n"));
 548   return (0);
 549 }
 550
 551 /*
 552  * ipcp_nakci - Peer has sent a NAK for some of our CIs.
 553  * This should not modify any state if the Nak is bad
 554  * or if IPCP is in the LS_OPENED state.
 555  *
 556  * Returns:
 557  *  0 - Nak was bad.
 558  *  1 - Nak was good.
 559  */
 560 static int
 561 ipcp_nakci(fsm *f, u_char *p, int len)
 562 {
 563   ipcp_options *go = &ipcp_gotoptions[f->unit];
 564   u_char cimaxslotindex, cicflag;
 565   u_char citype, cilen, *next;
 566   u_short cishort;
 567   u32_t ciaddr1, ciaddr2, l, cidnsaddr;
 568   ipcp_options no;    /* options we've seen Naks for */
 569   ipcp_options try;    /* options to request next time */
 570
 571   BZERO(&no, sizeof(no));
 572   try = *go;
 573
 574   /*
 575    * Any Nak'd CIs must be in exactly the same order that we sent.
 576    * Check packet length and CI length at each step.
 577    * If we find any deviations, then this packet is bad.
 578    */
 579 #define NAKCIADDR(opt, neg, old, code) \
 580   if (go->neg && \
 581       len >= (cilen = (old? CILEN_ADDRS: CILEN_ADDR)) && \
 582       p[1] == cilen && \
 583       p[0] == opt) { \
 584     len -= cilen; \
 585     INCPTR(2, p); \
 586     GETLONG(l, p); \
 587     ciaddr1 = htonl(l); \
 588     if (old) { \
 589       GETLONG(l, p); \
 590       ciaddr2 = htonl(l); \
 591       no.old_addrs = 1; \
 592     } else { \
 593       ciaddr2 = 0; \
 594     } \
 595     no.neg = 1; \
 596     code \
 597   }
 598
 599 #define NAKCIVJ(opt, neg, code) \
 600   if (go->neg && \
 601       ((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
 602       len >= cilen && \
 603       p[0] == opt) { \
 604     len -= cilen; \
 605     INCPTR(2, p); \
 606     GETSHORT(cishort, p); \
 607     no.neg = 1; \
 608     code \
 609   }
 610
 611 #define NAKCIDNS(opt, neg, code) \
 612   if (go->neg && \
 613       ((cilen = p[1]) == CILEN_ADDR) && \
 614       len >= cilen && \
 615       p[0] == opt) { \
 616     len -= cilen; \
 617     INCPTR(2, p); \
 618     GETLONG(l, p); \
 619     cidnsaddr = htonl(l); \
 620     no.neg = 1; \
 621     code \
 622   }
 623
 624   /*
 625    * Accept the peer's idea of {our,his} address, if different
 626    * from our idea, only if the accept_{local,remote} flag is set.
 627    */
 628   NAKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr, go->old_addrs,
 629     if (go->accept_local && ciaddr1) { /* Do we know our address? */
 630       try.ouraddr = ciaddr1;
 631       IPCPDEBUG((LOG_INFO, "local IP address %s\n",
 632            inet_ntoa(ciaddr1)));
 633     }
 634     if (go->accept_remote && ciaddr2) { /* Does he know his? */
 635       try.hisaddr = ciaddr2;
 636       IPCPDEBUG((LOG_INFO, "remote IP address %s\n",
 637            inet_ntoa(ciaddr2)));
 638     }
 639   );
 640
 641   /*
 642    * Accept the peer's value of maxslotindex provided that it
 643    * is less than what we asked for.  Turn off slot-ID compression
 644    * if the peer wants.  Send old-style compress-type option if
 645    * the peer wants.
 646    */
 647   NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
 648     if (cilen == CILEN_VJ) {
 649       GETCHAR(cimaxslotindex, p);
 650       GETCHAR(cicflag, p);
 651       if (cishort == IPCP_VJ_COMP) {
 652         try.old_vj = 0;
 653         if (cimaxslotindex < go->maxslotindex) {
 654           try.maxslotindex = cimaxslotindex;
 655         }
 656         if (!cicflag) {
 657           try.cflag = 0;
 658         }
 659       } else {
 660         try.neg_vj = 0;
 661       }
 662     } else {
 663       if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
 664         try.old_vj = 1;
 665         try.vj_protocol = cishort;
 666       } else {
 667         try.neg_vj = 0;
 668       }
 669     }
 670   );
 671
 672   NAKCIDNS(CI_MS_DNS1, req_dns1,
 673       try.dnsaddr[0] = cidnsaddr;
 674         IPCPDEBUG((LOG_INFO, "primary DNS address %s\n", inet_ntoa(cidnsaddr)));
 675       );
 676
 677   NAKCIDNS(CI_MS_DNS2, req_dns2,
 678       try.dnsaddr[1] = cidnsaddr;
 679         IPCPDEBUG((LOG_INFO, "secondary DNS address %s\n", inet_ntoa(cidnsaddr)));
 680       );
 681
 682   /*
 683   * There may be remaining CIs, if the peer is requesting negotiation
 684   * on an option that we didn't include in our request packet.
 685   * If they want to negotiate about IP addresses, we comply.
 686   * If they want us to ask for compression, we refuse.
 687   */
 688   while (len > CILEN_VOID) {
 689     GETCHAR(citype, p);
 690     GETCHAR(cilen, p);
 691     if( (len -= cilen) < 0 ) {
 692       goto bad;
 693     }
 694     next = p + cilen - 2;
 695
 696     switch (citype) {
 697       case CI_COMPRESSTYPE:
 698         if (go->neg_vj || no.neg_vj ||
 699             (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
 700           goto bad;
 701         }
 702         no.neg_vj = 1;
 703         break;
 704       case CI_ADDRS:
 705         if ((go->neg_addr && go->old_addrs) || no.old_addrs
 706             || cilen != CILEN_ADDRS) {
 707           goto bad;
 708         }
 709         try.neg_addr = 1;
 710         try.old_addrs = 1;
 711         GETLONG(l, p);
 712         ciaddr1 = htonl(l);
 713         if (ciaddr1 && go->accept_local) {
 714           try.ouraddr = ciaddr1;
 715         }
 716         GETLONG(l, p);
 717         ciaddr2 = htonl(l);
 718         if (ciaddr2 && go->accept_remote) {
 719           try.hisaddr = ciaddr2;
 720         }
 721         no.old_addrs = 1;
 722         break;
 723       case CI_ADDR:
 724         if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR) {
 725           goto bad;
 726         }
 727         try.old_addrs = 0;
 728         GETLONG(l, p);
 729         ciaddr1 = htonl(l);
 730         if (ciaddr1 && go->accept_local) {
 731           try.ouraddr = ciaddr1;
 732         }
 733         if (try.ouraddr != 0) {
 734           try.neg_addr = 1;
 735         }
 736         no.neg_addr = 1;
 737         break;
 738     }
 739     p = next;
 740   }
 741
 742   /* If there is still anything left, this packet is bad. */
 743   if (len != 0) {
 744     goto bad;
 745   }
 746
 747   /*
 748    * OK, the Nak is good.  Now we can update state.
 749    */
 750   if (f->state != LS_OPENED) {
 751     *go = try;
 752   }
 753
 754   return 1;
 755
 756 bad:
 757   IPCPDEBUG((LOG_INFO, "ipcp_nakci: received bad Nak!\n"));
 758   return 0;
 759 }
 760
 761
 762 /*
 763  * ipcp_rejci - Reject some of our CIs.
 764  */
 765 static int
 766 ipcp_rejci(fsm *f, u_char *p, int len)
 767 {
 768   ipcp_options *go = &ipcp_gotoptions[f->unit];
 769   u_char cimaxslotindex, ciflag, cilen;
 770   u_short cishort;
 771   u32_t cilong;
 772   ipcp_options try;    /* options to request next time */
 773
 774   try = *go;
 775   /*
 776    * Any Rejected CIs must be in exactly the same order that we sent.
 777    * Check packet length and CI length at each step.
 778    * If we find any deviations, then this packet is bad.
 779    */
 780 #define REJCIADDR(opt, neg, old, val1, val2) \
 781   if (go->neg && \
 782       len >= (cilen = old? CILEN_ADDRS: CILEN_ADDR) && \
 783       p[1] == cilen && \
 784       p[0] == opt) { \
 785     u32_t l; \
 786     len -= cilen; \
 787     INCPTR(2, p); \
 788     GETLONG(l, p); \
 789     cilong = htonl(l); \
 790     /* Check rejected value. */ \
 791     if (cilong != val1) { \
 792       goto bad; \
 793     } \
 794     if (old) { \
 795       GETLONG(l, p); \
 796       cilong = htonl(l); \
 797       /* Check rejected value. */ \
 798       if (cilong != val2) { \
 799         goto bad; \
 800       } \
 801     } \
 802     try.neg = 0; \
 803   }
 804
 805 #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
 806   if (go->neg && \
 807       p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
 808       len >= p[1] && \
 809       p[0] == opt) { \
 810     len -= p[1]; \
 811     INCPTR(2, p); \
 812     GETSHORT(cishort, p); \
 813     /* Check rejected value. */  \
 814     if (cishort != val) { \
 815       goto bad; \
 816     } \
 817     if (!old) { \
 818       GETCHAR(cimaxslotindex, p); \
 819       if (cimaxslotindex != maxslot) { \
 820         goto bad; \
 821       } \
 822       GETCHAR(ciflag, p); \
 823       if (ciflag != cflag) { \
 824         goto bad; \
 825       } \
 826     } \
 827     try.neg = 0; \
 828   }
 829
 830 #define REJCIDNS(opt, neg, dnsaddr) \
 831   if (go->neg && \
 832       ((cilen = p[1]) == CILEN_ADDR) && \
 833       len >= cilen && \
 834       p[0] == opt) { \
 835     u32_t l; \
 836     len -= cilen; \
 837     INCPTR(2, p); \
 838     GETLONG(l, p); \
 839     cilong = htonl(l); \
 840     /* Check rejected value. */ \
 841     if (cilong != dnsaddr) { \
 842       goto bad; \
 843     } \
 844     try.neg = 0; \
 845   }
 846
 847   REJCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr,
 848         go->old_addrs, go->ouraddr, go->hisaddr);
 849
 850   REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
 851       go->maxslotindex, go->cflag);
 852
 853   REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
 854
 855   REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
 856
 857   /*
 858    * If there are any remaining CIs, then this packet is bad.
 859    */
 860   if (len != 0) {
 861     goto bad;
 862   }
 863   /*
 864    * Now we can update state.
 865    */
 866   if (f->state != LS_OPENED) {
 867     *go = try;
 868   }
 869   return 1;
 870
 871 bad:
 872   IPCPDEBUG((LOG_INFO, "ipcp_rejci: received bad Reject!\n"));
 873   return 0;
 874 }
 875
 876
 877 /*
 878  * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
 879  *
 880  * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
 881  * appropriately.  If reject_if_disagree is non-zero, doesn't return
 882  * CONFNAK; returns CONFREJ if it can't return CONFACK.
 883  */
 884 static int
 885 ipcp_reqci(fsm *f, u_char *inp/* Requested CIs */,int *len/* Length of requested CIs */,int reject_if_disagree)
 886 {
 887   ipcp_options *wo = &ipcp_wantoptions[f->unit];
 888   ipcp_options *ho = &ipcp_hisoptions[f->unit];
 889   ipcp_options *ao = &ipcp_allowoptions[f->unit];
 890 #ifdef OLD_CI_ADDRS
 891   ipcp_options *go = &ipcp_gotoptions[f->unit];
 892 #endif
 893   u_char *cip, *next;     /* Pointer to current and next CIs */
 894   u_short cilen, citype;  /* Parsed len, type */
 895   u_short cishort;        /* Parsed short value */
 896   u32_t tl, ciaddr1;      /* Parsed address values */
 897 #ifdef OLD_CI_ADDRS
 898   u32_t ciaddr2;          /* Parsed address values */
 899 #endif
 900   int rc = CONFACK;       /* Final packet return code */
 901   int orc;                /* Individual option return code */
 902   u_char *p;              /* Pointer to next char to parse */
 903   u_char *ucp = inp;      /* Pointer to current output char */
 904   int l = *len;           /* Length left */
 905   u_char maxslotindex, cflag;
 906   int d;
 907
 908   cis_received[f->unit] = 1;
 909
 910   /*
 911    * Reset all his options.
 912    */
 913   BZERO(ho, sizeof(*ho));
 914
 915   /*
 916    * Process all his options.
 917    */
 918   next = inp;
 919   while (l) {
 920     orc = CONFACK;       /* Assume success */
 921     cip = p = next;      /* Remember begining of CI */
 922     if (l < 2 ||         /* Not enough data for CI header or */
 923         p[1] < 2 ||      /*  CI length too small or */
 924         p[1] > l) {      /*  CI length too big? */
 925       IPCPDEBUG((LOG_INFO, "ipcp_reqci: bad CI length!\n"));
 926       orc = CONFREJ;     /* Reject bad CI */
 927       cilen = l;         /* Reject till end of packet */
 928       l = 0;             /* Don't loop again */
 929       goto endswitch;
 930     }
 931     GETCHAR(citype, p);  /* Parse CI type */
 932     GETCHAR(cilen, p);   /* Parse CI length */
 933     l -= cilen;          /* Adjust remaining length */
 934     next += cilen;       /* Step to next CI */
 935
 936     switch (citype) {      /* Check CI type */
 937 #ifdef OLD_CI_ADDRS /* Need to save space... */
 938       case CI_ADDRS:
 939         IPCPDEBUG((LOG_INFO, "ipcp_reqci: received ADDRS\n"));
 940         if (!ao->neg_addr ||
 941             cilen != CILEN_ADDRS) {  /* Check CI length */
 942           orc = CONFREJ;    /* Reject CI */
 943           break;
 944         }
 945
 946         /*
 947          * If he has no address, or if we both have his address but
 948          * disagree about it, then NAK it with our idea.
 949          * In particular, if we don't know his address, but he does,
 950          * then accept it.
 951          */
 952         GETLONG(tl, p);    /* Parse source address (his) */
 953         ciaddr1 = htonl(tl);
 954         IPCPDEBUG((LOG_INFO, "his addr %s\n", inet_ntoa(ciaddr1)));
 955         if (ciaddr1 != wo->hisaddr
 956             && (ciaddr1 == 0 || !wo->accept_remote)) {
 957           orc = CONFNAK;
 958           if (!reject_if_disagree) {
 959             DECPTR(sizeof(u32_t), p);
 960             tl = ntohl(wo->hisaddr);
 961             PUTLONG(tl, p);
 962           }
 963         } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
 964           /*
 965            * If neither we nor he knows his address, reject the option.
 966            */
 967           orc = CONFREJ;
 968           wo->req_addr = 0;  /* don't NAK with 0.0.0.0 later */
 969           break;
 970         }
 971
 972         /*
 973          * If he doesn't know our address, or if we both have our address
 974          * but disagree about it, then NAK it with our idea.
 975          */
 976         GETLONG(tl, p);    /* Parse desination address (ours) */
 977         ciaddr2 = htonl(tl);
 978         IPCPDEBUG((LOG_INFO, "our addr %s\n", inet_ntoa(ciaddr2)));
 979         if (ciaddr2 != wo->ouraddr) {
 980           if (ciaddr2 == 0 || !wo->accept_local) {
 981             orc = CONFNAK;
 982             if (!reject_if_disagree) {
 983               DECPTR(sizeof(u32_t), p);
 984               tl = ntohl(wo->ouraddr);
 985               PUTLONG(tl, p);
 986             }
 987           } else {
 988             go->ouraddr = ciaddr2;  /* accept peer's idea */
 989           }
 990         }
 991
 992         ho->neg_addr = 1;
 993         ho->old_addrs = 1;
 994         ho->hisaddr = ciaddr1;
 995         ho->ouraddr = ciaddr2;
 996         break;
 997 #endif
 998
 999       case CI_ADDR:
1000         if (!ao->neg_addr) {
1001           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Reject ADDR not allowed\n"));
1002           orc = CONFREJ;        /* Reject CI */
1003           break;
1004         } else if (cilen != CILEN_ADDR) {  /* Check CI length */
1005           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Reject ADDR bad len\n"));
1006           orc = CONFREJ;        /* Reject CI */
1007           break;
1008         }
1009
1010         /*
1011          * If he has no address, or if we both have his address but
1012          * disagree about it, then NAK it with our idea.
1013          * In particular, if we don't know his address, but he does,
1014          * then accept it.
1015          */
1016         GETLONG(tl, p);  /* Parse source address (his) */
1017         ciaddr1 = htonl(tl);
1018         if (ciaddr1 != wo->hisaddr
1019             && (ciaddr1 == 0 || !wo->accept_remote)) {
1020           orc = CONFNAK;
1021           if (!reject_if_disagree) {
1022             DECPTR(sizeof(u32_t), p);
1023             tl = ntohl(wo->hisaddr);
1024             PUTLONG(tl, p);
1025           }
1026           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Nak ADDR %s\n", inet_ntoa(ciaddr1)));
1027         } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1028           /*
1029            * Don't ACK an address of 0.0.0.0 - reject it instead.
1030            */
1031           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Reject ADDR %s\n", inet_ntoa(ciaddr1)));
1032           orc = CONFREJ;
1033           wo->req_addr = 0;  /* don't NAK with 0.0.0.0 later */
1034           break;
1035         }
1036
1037         ho->neg_addr = 1;
1038         ho->hisaddr = ciaddr1;
1039         IPCPDEBUG((LOG_INFO, "ipcp_reqci: ADDR %s\n", inet_ntoa(ciaddr1)));
1040         break;
1041
1042       case CI_MS_DNS1:
1043       case CI_MS_DNS2:
1044         /* Microsoft primary or secondary DNS request */
1045         d = citype == CI_MS_DNS2;
1046
1047         /* If we do not have a DNS address then we cannot send it */
1048         if (ao->dnsaddr[d] == 0 ||
1049             cilen != CILEN_ADDR) {  /* Check CI length */
1050           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting DNS%d Request\n", d+1));
1051           orc = CONFREJ;        /* Reject CI */
1052           break;
1053         }
1054         GETLONG(tl, p);
1055         if (htonl(tl) != ao->dnsaddr[d]) {
1056           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Naking DNS%d Request %d\n",
1057                 d+1, inet_ntoa(tl)));
1058           DECPTR(sizeof(u32_t), p);
1059           tl = ntohl(ao->dnsaddr[d]);
1060           PUTLONG(tl, p);
1061           orc = CONFNAK;
1062         }
1063         IPCPDEBUG((LOG_INFO, "ipcp_reqci: received DNS%d Request\n", d+1));
1064         break;
1065
1066       case CI_MS_WINS1:
1067       case CI_MS_WINS2:
1068         /* Microsoft primary or secondary WINS request */
1069         d = citype == CI_MS_WINS2;
1070         IPCPDEBUG((LOG_INFO, "ipcp_reqci: received WINS%d Request\n", d+1));
1071
1072         /* If we do not have a DNS address then we cannot send it */
1073         if (ao->winsaddr[d] == 0 ||
1074           cilen != CILEN_ADDR) {  /* Check CI length */
1075           orc = CONFREJ;      /* Reject CI */
1076           break;
1077         }
1078         GETLONG(tl, p);
1079         if (htonl(tl) != ao->winsaddr[d]) {
1080           DECPTR(sizeof(u32_t), p);
1081           tl = ntohl(ao->winsaddr[d]);
1082           PUTLONG(tl, p);
1083           orc = CONFNAK;
1084         }
1085         break;
1086
1087       case CI_COMPRESSTYPE:
1088         if (!ao->neg_vj) {
1089           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting COMPRESSTYPE not allowed\n"));
1090           orc = CONFREJ;
1091           break;
1092         } else if (cilen != CILEN_VJ && cilen != CILEN_COMPRESS) {
1093           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting COMPRESSTYPE len=%d\n", cilen));
1094           orc = CONFREJ;
1095           break;
1096         }
1097         GETSHORT(cishort, p);
1098
1099         if (!(cishort == IPCP_VJ_COMP ||
1100             (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
1101           IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting COMPRESSTYPE %d\n", cishort));
1102           orc = CONFREJ;
1103           break;
1104         }
1105
1106         ho->neg_vj = 1;
1107         ho->vj_protocol = cishort;
1108         if (cilen == CILEN_VJ) {
1109           GETCHAR(maxslotindex, p);
1110           if (maxslotindex > ao->maxslotindex) {
1111             IPCPDEBUG((LOG_INFO, "ipcp_reqci: Naking VJ max slot %d\n", maxslotindex));
1112             orc = CONFNAK;
1113             if (!reject_if_disagree) {
1114               DECPTR(1, p);
1115               PUTCHAR(ao->maxslotindex, p);
1116             }
1117           }
1118           GETCHAR(cflag, p);
1119           if (cflag && !ao->cflag) {
1120             IPCPDEBUG((LOG_INFO, "ipcp_reqci: Naking VJ cflag %d\n", cflag));
1121             orc = CONFNAK;
1122             if (!reject_if_disagree) {
1123               DECPTR(1, p);
1124               PUTCHAR(wo->cflag, p);
1125             }
1126           }
1127           ho->maxslotindex = maxslotindex;
1128           ho->cflag = cflag;
1129         } else {
1130           ho->old_vj = 1;
1131           ho->maxslotindex = MAX_SLOTS - 1;
1132           ho->cflag = 1;
1133         }
1134         IPCPDEBUG((LOG_INFO,
1135               "ipcp_reqci: received COMPRESSTYPE p=%d old=%d maxslot=%d cflag=%d\n",
1136               ho->vj_protocol, ho->old_vj, ho->maxslotindex, ho->cflag));
1137         break;
1138
1139       default:
1140         IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting unknown CI type %d\n", citype));
1141         orc = CONFREJ;
1142         break;
1143     }
1144
1145 endswitch:
1146     if (orc == CONFACK &&    /* Good CI */
1147         rc != CONFACK) {     /*  but prior CI wasnt? */
1148       continue;              /* Don't send this one */
1149     }
1150
1151     if (orc == CONFNAK) {    /* Nak this CI? */
1152       if (reject_if_disagree) {  /* Getting fed up with sending NAKs? */
1153         IPCPDEBUG((LOG_INFO, "ipcp_reqci: Rejecting too many naks\n"));
1154         orc = CONFREJ;       /* Get tough if so */
1155       } else {
1156         if (rc == CONFREJ) { /* Rejecting prior CI? */
1157           continue;          /* Don't send this one */
1158         }
1159         if (rc == CONFACK) { /* Ack'd all prior CIs? */
1160           rc = CONFNAK;      /* Not anymore... */
1161           ucp = inp;         /* Backup */
1162         }
1163       }
1164     }
1165
1166     if (orc == CONFREJ &&    /* Reject this CI */
1167         rc != CONFREJ) {  /*  but no prior ones? */
1168       rc = CONFREJ;
1169       ucp = inp;        /* Backup */
1170     }
1171
1172     /* Need to move CI? */
1173     if (ucp != cip) {
1174       BCOPY(cip, ucp, cilen);  /* Move it */
1175     }
1176
1177     /* Update output pointer */
1178     INCPTR(cilen, ucp);
1179   }
1180
1181   /*
1182    * If we aren't rejecting this packet, and we want to negotiate
1183    * their address, and they didn't send their address, then we
1184    * send a NAK with a CI_ADDR option appended.  We assume the
1185    * input buffer is long enough that we can append the extra
1186    * option safely.
1187    */
1188   if (rc != CONFREJ && !ho->neg_addr &&
1189       wo->req_addr && !reject_if_disagree) {
1190     IPCPDEBUG((LOG_INFO, "ipcp_reqci: Requesting peer address\n"));
1191     if (rc == CONFACK) {
1192       rc = CONFNAK;
1193       ucp = inp;        /* reset pointer */
1194       wo->req_addr = 0;    /* don't ask again */
1195     }
1196     PUTCHAR(CI_ADDR, ucp);
1197     PUTCHAR(CILEN_ADDR, ucp);
1198     tl = ntohl(wo->hisaddr);
1199     PUTLONG(tl, ucp);
1200   }
1201
1202   *len = (int)(ucp - inp);    /* Compute output length */
1203   IPCPDEBUG((LOG_INFO, "ipcp_reqci: returning Configure-%s\n", CODENAME(rc)));
1204   return (rc);      /* Return final code */
1205 }
1206
1207
1208 #if 0
1209 /*
1210  * ip_check_options - check that any IP-related options are OK,
1211  * and assign appropriate defaults.
1212  */
1213 static void
1214 ip_check_options(u_long localAddr)
1215 {
1216   ipcp_options *wo = &ipcp_wantoptions[0];
1217
1218   /*
1219    * Load our default IP address but allow the remote host to give us
1220    * a new address.
1221    */
1222   if (wo->ouraddr == 0 && !ppp_settings.disable_defaultip) {
1223     wo->accept_local = 1;  /* don't insist on this default value */
1224     wo->ouraddr = htonl(localAddr);
1225   }
1226 }
1227 #endif
1228
1229
1230 /*
1231  * ipcp_up - IPCP has come UP.
1232  *
1233  * Configure the IP network interface appropriately and bring it up.
1234  */
1235 static void
1236 ipcp_up(fsm *f)
1237 {
1238   u32_t mask;
1239   ipcp_options *ho = &ipcp_hisoptions[f->unit];
1240   ipcp_options *go = &ipcp_gotoptions[f->unit];
1241   ipcp_options *wo = &ipcp_wantoptions[f->unit];
1242
1243   np_up(f->unit, PPP_IP);
1244   IPCPDEBUG((LOG_INFO, "ipcp: up\n"));
1245
1246   /*
1247    * We must have a non-zero IP address for both ends of the link.
1248    */
1249   if (!ho->neg_addr) {
1250     ho->hisaddr = wo->hisaddr;
1251   }
1252
1253   if (ho->hisaddr == 0) {
1254     IPCPDEBUG((LOG_ERR, "Could not determine remote IP address\n"));
1255     ipcp_close(f->unit, "Could not determine remote IP address");
1256     return;
1257   }
1258   if (go->ouraddr == 0) {
1259     IPCPDEBUG((LOG_ERR, "Could not determine local IP address\n"));
1260     ipcp_close(f->unit, "Could not determine local IP address");
1261     return;
1262   }
1263
1264   if (ppp_settings.usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
1265     /*pppGotDNSAddrs(go->dnsaddr[0], go->dnsaddr[1]);*/
1266   }
1267
1268   /*
1269    * Check that the peer is allowed to use the IP address it wants.
1270    */
1271   if (!auth_ip_addr(f->unit, ho->hisaddr)) {
1272     IPCPDEBUG((LOG_ERR, "Peer is not authorized to use remote address %s\n",
1273         inet_ntoa(ho->hisaddr)));
1274     ipcp_close(f->unit, "Unauthorized remote IP address");
1275     return;
1276   }
1277
1278   /* set tcp compression */
1279   sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
1280
1281   /*
1282    * Set IP addresses and (if specified) netmask.
1283    */
1284   mask = GetMask(go->ouraddr);
1285
1286   if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask, go->dnsaddr[0], go->dnsaddr[1])) {
1287     IPCPDEBUG((LOG_WARNING, "sifaddr failed\n"));
1288     ipcp_close(f->unit, "Interface configuration failed");
1289     return;
1290   }
1291
1292   /* bring the interface up for IP */
1293   if (!sifup(f->unit)) {
1294     IPCPDEBUG((LOG_WARNING, "sifup failed\n"));
1295     ipcp_close(f->unit, "Interface configuration failed");
1296     return;
1297   }
1298
1299   sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1300
1301   /* assign a default route through the interface if required */
1302   if (ipcp_wantoptions[f->unit].default_route) {
1303     if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr)) {
1304       default_route_set[f->unit] = 1;
1305     }
1306   }
1307
1308   IPCPDEBUG((LOG_NOTICE, "local  IP address %s\n", inet_ntoa(go->ouraddr)));
1309   IPCPDEBUG((LOG_NOTICE, "remote IP address %s\n", inet_ntoa(ho->hisaddr)));
1310   if (go->dnsaddr[0]) {
1311     IPCPDEBUG((LOG_NOTICE, "primary   DNS address %s\n", inet_ntoa(go->dnsaddr[0])));
1312   }
1313   if (go->dnsaddr[1]) {
1314     IPCPDEBUG((LOG_NOTICE, "secondary DNS address %s\n", inet_ntoa(go->dnsaddr[1])));
1315   }
1316 }
1317
1318
1319 /*
1320  * ipcp_down - IPCP has gone DOWN.
1321  *
1322  * Take the IP network interface down, clear its addresses
1323  * and delete routes through it.
1324  */
1325 static void
1326 ipcp_down(fsm *f)
1327 {
1328   IPCPDEBUG((LOG_INFO, "ipcp: down\n"));
1329   np_down(f->unit, PPP_IP);
1330   sifvjcomp(f->unit, 0, 0, 0);
1331
1332   sifdown(f->unit);
1333   ipcp_clear_addrs(f->unit);
1334 }
1335
1336
1337 /*
1338  * ipcp_clear_addrs() - clear the interface addresses, routes, etc.
1339  */
1340 static void
1341 ipcp_clear_addrs(int unit)
1342 {
1343   u32_t ouraddr, hisaddr;
1344
1345   ouraddr = ipcp_gotoptions[unit].ouraddr;
1346   hisaddr = ipcp_hisoptions[unit].hisaddr;
1347   if (default_route_set[unit]) {
1348     cifdefaultroute(unit, ouraddr, hisaddr);
1349     default_route_set[unit] = 0;
1350   }
1351   cifaddr(unit, ouraddr, hisaddr);
1352 }
1353
1354
1355 /*
1356  * ipcp_finished - possibly shut down the lower layers.
1357  */
1358 static void
1359 ipcp_finished(fsm *f)
1360 {
1361   np_finished(f->unit, PPP_IP);
1362 }
1363
1364 #if 0
1365 static int
1366 ipcp_printpkt(u_char *p, int plen, void (*printer) (void *, char *, ...), void *arg)
1367 {
1368   LWIP_UNUSED_ARG(p);
1369   LWIP_UNUSED_ARG(plen);
1370   LWIP_UNUSED_ARG(printer);
1371   LWIP_UNUSED_ARG(arg);
1372   return 0;
1373 }
1374
1375 /*
1376  * ip_active_pkt - see if this IP packet is worth bringing the link up for.
1377  * We don't bring the link up for IP fragments or for TCP FIN packets
1378  * with no data.
1379  */
1380 #define IP_HDRLEN   20  /* bytes */
1381 #define IP_OFFMASK  0x1fff
1382 #define IPPROTO_TCP 6
1383 #define TCP_HDRLEN  20
1384 #define TH_FIN      0x01
1385
1386 /*
1387  * We use these macros because the IP header may be at an odd address,
1388  * and some compilers might use word loads to get th_off or ip_hl.
1389  */
1390
1391 #define net_short(x)    (((x)[0] << 8) + (x)[1])
1392 #define get_iphl(x)     (((unsigned char *)(x))[0] & 0xF)
1393 #define get_ipoff(x)    net_short((unsigned char *)(x) + 6)
1394 #define get_ipproto(x)  (((unsigned char *)(x))[9])
1395 #define get_tcpoff(x)   (((unsigned char *)(x))[12] >> 4)
1396 #define get_tcpflags(x) (((unsigned char *)(x))[13])
1397
1398 static int
1399 ip_active_pkt(u_char *pkt, int len)
1400 {
1401   u_char *tcp;
1402   int hlen;
1403
1404   len -= PPP_HDRLEN;
1405   pkt += PPP_HDRLEN;
1406   if (len < IP_HDRLEN) {
1407     return 0;
1408   }
1409   if ((get_ipoff(pkt) & IP_OFFMASK) != 0) {
1410     return 0;
1411   }
1412   if (get_ipproto(pkt) != IPPROTO_TCP) {
1413     return 1;
1414   }
1415   hlen = get_iphl(pkt) * 4;
1416   if (len < hlen + TCP_HDRLEN) {
1417     return 0;
1418   }
1419   tcp = pkt + hlen;
1420   if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4) {
1421     return 0;
1422   }
1423   return 1;
1424 }
1425 #endif
1426
1427 #endif /* PPP_SUPPORT */