usr.sbin/ppp/ccp.c

   1 /*-
   2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
   3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
   4  *                           Internet Initiative Japan, Inc (IIJ)
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/usr.sbin/ppp/ccp.c,v 1.54.2.7 2002/09/01 02:12:22 brian Exp $
  29  * $DragonFly: src/usr.sbin/ppp/ccp.c,v 1.2 2003/06/17 04:30:00 dillon Exp $
  30  */
  31
  32 #include <sys/param.h>
  33 #include <netinet/in.h>
  34 #include <netinet/in_systm.h>
  35 #include <netinet/ip.h>
  36 #include <sys/socket.h>
  37 #include <sys/un.h>
  38
  39 #include <stdarg.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>     /* memcpy() on some archs */
  43 #include <termios.h>
  44
  45 #include "layer.h"
  46 #include "defs.h"
  47 #include "command.h"
  48 #include "mbuf.h"
  49 #include "log.h"
  50 #include "timer.h"
  51 #include "fsm.h"
  52 #include "proto.h"
  53 #include "pred.h"
  54 #include "deflate.h"
  55 #include "throughput.h"
  56 #include "iplist.h"
  57 #include "slcompress.h"
  58 #include "lqr.h"
  59 #include "hdlc.h"
  60 #include "lcp.h"
  61 #include "ccp.h"
  62 #include "ncpaddr.h"
  63 #include "ipcp.h"
  64 #include "filter.h"
  65 #include "descriptor.h"
  66 #include "prompt.h"
  67 #include "link.h"
  68 #include "mp.h"
  69 #include "async.h"
  70 #include "physical.h"
  71 #ifndef NORADIUS
  72 #include "radius.h"
  73 #endif
  74 #ifndef NODES
  75 #include "mppe.h"
  76 #endif
  77 #include "ipv6cp.h"
  78 #include "ncp.h"
  79 #include "bundle.h"
  80
  81 static void CcpSendConfigReq(struct fsm *);
  82 static void CcpSentTerminateReq(struct fsm *);
  83 static void CcpSendTerminateAck(struct fsm *, u_char);
  84 static void CcpDecodeConfig(struct fsm *, u_char *, u_char *, int,
  85                             struct fsm_decode *);
  86 static void CcpLayerStart(struct fsm *);
  87 static void CcpLayerFinish(struct fsm *);
  88 static int CcpLayerUp(struct fsm *);
  89 static void CcpLayerDown(struct fsm *);
  90 static void CcpInitRestartCounter(struct fsm *, int);
  91 static int CcpRecvResetReq(struct fsm *);
  92 static void CcpRecvResetAck(struct fsm *, u_char);
  93
  94 static struct fsm_callbacks ccp_Callbacks = {
  95   CcpLayerUp,
  96   CcpLayerDown,
  97   CcpLayerStart,
  98   CcpLayerFinish,
  99   CcpInitRestartCounter,
 100   CcpSendConfigReq,
 101   CcpSentTerminateReq,
 102   CcpSendTerminateAck,
 103   CcpDecodeConfig,
 104   CcpRecvResetReq,
 105   CcpRecvResetAck
 106 };
 107
 108 static const char * const ccp_TimerNames[] =
 109   {"CCP restart", "CCP openmode", "CCP stopped"};
 110
 111 static const char *
 112 protoname(int proto)
 113 {
 114   static char const * const cftypes[] = {
 115     /* Check out the latest ``Compression Control Protocol'' rfc (1962) */
 116     "OUI",              /* 0: OUI */
 117     "PRED1",            /* 1: Predictor type 1 */
 118     "PRED2",            /* 2: Predictor type 2 */
 119     "PUDDLE",           /* 3: Puddle Jumber */
 120     NULL, NULL, NULL, NULL, NULL, NULL,
 121     NULL, NULL, NULL, NULL, NULL, NULL,
 122     "HWPPC",            /* 16: Hewlett-Packard PPC */
 123     "STAC",             /* 17: Stac Electronics LZS (rfc1974) */
 124     "MPPE",             /* 18: Microsoft PPC (rfc2118) and */
 125                         /*     Microsoft PPE (draft-ietf-pppext-mppe) */
 126     "GAND",             /* 19: Gandalf FZA (rfc1993) */
 127     "V42BIS",           /* 20: ARG->DATA.42bis compression */
 128     "BSD",              /* 21: BSD LZW Compress */
 129     NULL,
 130     "LZS-DCP",          /* 23: LZS-DCP Compression Protocol (rfc1967) */
 131     "MAGNALINK/DEFLATE",/* 24: Magnalink Variable Resource (rfc1975) */
 132                         /* 24: Deflate (according to pppd-2.3.*) */
 133     "DCE",              /* 25: Data Circuit-Terminating Equip (rfc1976) */
 134     "DEFLATE",          /* 26: Deflate (rfc1979) */
 135   };
 136
 137   if (proto < 0 || proto > sizeof cftypes / sizeof *cftypes ||
 138       cftypes[proto] == NULL) {
 139     if (proto == -1)
 140       return "none";
 141     return HexStr(proto, NULL, 0);
 142   }
 143
 144   return cftypes[proto];
 145 }
 146
 147 /* We support these algorithms, and Req them in the given order */
 148 static const struct ccp_algorithm * const algorithm[] = {
 149   &DeflateAlgorithm,
 150   &Pred1Algorithm,
 151   &PppdDeflateAlgorithm
 152 #ifndef NODES
 153   , &MPPEAlgorithm
 154 #endif
 155 };
 156
 157 #define NALGORITHMS (sizeof algorithm/sizeof algorithm[0])
 158
 159 int
 160 ccp_ReportStatus(struct cmdargs const *arg)
 161 {
 162   struct ccp_opt **o;
 163   struct link *l;
 164   struct ccp *ccp;
 165   int f;
 166
 167   l = command_ChooseLink(arg);
 168   ccp = &l->ccp;
 169
 170   prompt_Printf(arg->prompt, "%s: %s [%s]\n", l->name, ccp->fsm.name,
 171                 State2Nam(ccp->fsm.state));
 172   if (ccp->fsm.state == ST_OPENED) {
 173     prompt_Printf(arg->prompt, " My protocol = %s, His protocol = %s\n",
 174                   protoname(ccp->my_proto), protoname(ccp->his_proto));
 175     prompt_Printf(arg->prompt, " Output: %ld --> %ld,  Input: %ld --> %ld\n",
 176                   ccp->uncompout, ccp->compout,
 177                   ccp->compin, ccp->uncompin);
 178   }
 179
 180   if (ccp->in.algorithm != -1)
 181     prompt_Printf(arg->prompt, "\n Input Options:  %s\n",
 182                   (*algorithm[ccp->in.algorithm]->Disp)(&ccp->in.opt));
 183
 184   if (ccp->out.algorithm != -1) {
 185     o = &ccp->out.opt;
 186     for (f = 0; f < ccp->out.algorithm; f++)
 187       if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
 188         o = &(*o)->next;
 189     prompt_Printf(arg->prompt, " Output Options: %s\n",
 190                   (*algorithm[ccp->out.algorithm]->Disp)(&(*o)->val));
 191   }
 192
 193   prompt_Printf(arg->prompt, "\n Defaults: ");
 194   prompt_Printf(arg->prompt, "FSM retry = %us, max %u Config"
 195                 " REQ%s, %u Term REQ%s\n", ccp->cfg.fsm.timeout,
 196                 ccp->cfg.fsm.maxreq, ccp->cfg.fsm.maxreq == 1 ? "" : "s",
 197                 ccp->cfg.fsm.maxtrm, ccp->cfg.fsm.maxtrm == 1 ? "" : "s");
 198   prompt_Printf(arg->prompt, "           deflate windows: ");
 199   prompt_Printf(arg->prompt, "incoming = %d, ", ccp->cfg.deflate.in.winsize);
 200   prompt_Printf(arg->prompt, "outgoing = %d\n", ccp->cfg.deflate.out.winsize);
 201 #ifndef NODES
 202   prompt_Printf(arg->prompt, "           MPPE: ");
 203   if (ccp->cfg.mppe.keybits)
 204     prompt_Printf(arg->prompt, "%d bits, ", ccp->cfg.mppe.keybits);
 205   else
 206     prompt_Printf(arg->prompt, "any bits, ");
 207   switch (ccp->cfg.mppe.state) {
 208   case MPPE_STATEFUL:
 209     prompt_Printf(arg->prompt, "stateful");
 210     break;
 211   case MPPE_STATELESS:
 212     prompt_Printf(arg->prompt, "stateless");
 213     break;
 214   case MPPE_ANYSTATE:
 215     prompt_Printf(arg->prompt, "any state");
 216     break;
 217   }
 218   prompt_Printf(arg->prompt, "%s\n",
 219                 ccp->cfg.mppe.required ? ", required" : "");
 220 #endif
 221
 222   prompt_Printf(arg->prompt, "\n           DEFLATE:    %s\n",
 223                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE]));
 224   prompt_Printf(arg->prompt, "           PREDICTOR1: %s\n",
 225                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_PRED1]));
 226   prompt_Printf(arg->prompt, "           DEFLATE24:  %s\n",
 227                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE24]));
 228 #ifndef NODES
 229   prompt_Printf(arg->prompt, "           MPPE:       %s\n",
 230                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_MPPE]));
 231 #endif
 232   return 0;
 233 }
 234
 235 void
 236 ccp_SetupCallbacks(struct ccp *ccp)
 237 {
 238   ccp->fsm.fn = &ccp_Callbacks;
 239   ccp->fsm.FsmTimer.name = ccp_TimerNames[0];
 240   ccp->fsm.OpenTimer.name = ccp_TimerNames[1];
 241   ccp->fsm.StoppedTimer.name = ccp_TimerNames[2];
 242 }
 243
 244 void
 245 ccp_Init(struct ccp *ccp, struct bundle *bundle, struct link *l,
 246          const struct fsm_parent *parent)
 247 {
 248   /* Initialise ourselves */
 249
 250   fsm_Init(&ccp->fsm, "CCP", PROTO_CCP, 1, CCP_MAXCODE, LogCCP,
 251            bundle, l, parent, &ccp_Callbacks, ccp_TimerNames);
 252
 253   ccp->cfg.deflate.in.winsize = 0;
 254   ccp->cfg.deflate.out.winsize = 15;
 255   ccp->cfg.fsm.timeout = DEF_FSMRETRY;
 256   ccp->cfg.fsm.maxreq = DEF_FSMTRIES;
 257   ccp->cfg.fsm.maxtrm = DEF_FSMTRIES;
 258   ccp->cfg.neg[CCP_NEG_DEFLATE] = NEG_ENABLED|NEG_ACCEPTED;
 259   ccp->cfg.neg[CCP_NEG_PRED1] = NEG_ENABLED|NEG_ACCEPTED;
 260   ccp->cfg.neg[CCP_NEG_DEFLATE24] = 0;
 261 #ifndef NODES
 262   ccp->cfg.mppe.keybits = 0;
 263   ccp->cfg.mppe.state = MPPE_ANYSTATE;
 264   ccp->cfg.mppe.required = 0;
 265   ccp->cfg.neg[CCP_NEG_MPPE] = NEG_ENABLED|NEG_ACCEPTED;
 266 #endif
 267
 268   ccp_Setup(ccp);
 269 }
 270
 271 void
 272 ccp_Setup(struct ccp *ccp)
 273 {
 274   /* Set ourselves up for a startup */
 275   ccp->fsm.open_mode = 0;
 276   ccp->his_proto = ccp->my_proto = -1;
 277   ccp->reset_sent = ccp->last_reset = -1;
 278   ccp->in.algorithm = ccp->out.algorithm = -1;
 279   ccp->in.state = ccp->out.state = NULL;
 280   ccp->in.opt.hdr.id = -1;
 281   ccp->out.opt = NULL;
 282   ccp->his_reject = ccp->my_reject = 0;
 283   ccp->uncompout = ccp->compout = 0;
 284   ccp->uncompin = ccp->compin = 0;
 285 }
 286
 287 /*
 288  * Is ccp *REQUIRED* ?
 289  * We ask each of the configured ccp protocols if they're required and
 290  * return TRUE if they are.
 291  *
 292  * It's not possible for the peer to reject a required ccp protocol
 293  * without our state machine bringing the supporting lcp layer down.
 294  *
 295  * If ccp is required but not open, the NCP layer should not push
 296  * any data into the link.
 297  */
 298 int
 299 ccp_Required(struct ccp *ccp)
 300 {
 301   int f;
 302
 303   for (f = 0; f < NALGORITHMS; f++)
 304     if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
 305         (*algorithm[f]->Required)(&ccp->fsm))
 306       return 1;
 307
 308   return 0;
 309 }
 310
 311 /*
 312  * Report whether it's possible to increase a packet's size after
 313  * compression (and by how much).
 314  */
 315 int
 316 ccp_MTUOverhead(struct ccp *ccp)
 317 {
 318   if (ccp->fsm.state == ST_OPENED && ccp->out.algorithm >= 0)
 319     return algorithm[ccp->out.algorithm]->o.MTUOverhead;
 320
 321   return 0;
 322 }
 323
 324 static void
 325 CcpInitRestartCounter(struct fsm *fp, int what)
 326 {
 327   /* Set fsm timer load */
 328   struct ccp *ccp = fsm2ccp(fp);
 329
 330   fp->FsmTimer.load = ccp->cfg.fsm.timeout * SECTICKS;
 331   switch (what) {
 332     case FSM_REQ_TIMER:
 333       fp->restart = ccp->cfg.fsm.maxreq;
 334       break;
 335     case FSM_TRM_TIMER:
 336       fp->restart = ccp->cfg.fsm.maxtrm;
 337       break;
 338     default:
 339       fp->restart = 1;
 340       break;
 341   }
 342 }
 343
 344 static void
 345 CcpSendConfigReq(struct fsm *fp)
 346 {
 347   /* Send config REQ please */
 348   struct ccp *ccp = fsm2ccp(fp);
 349   struct ccp_opt **o;
 350   u_char *cp, buff[100];
 351   int f, alloc;
 352
 353   cp = buff;
 354   o = &ccp->out.opt;
 355   alloc = ccp->his_reject == 0 && ccp->out.opt == NULL;
 356   ccp->my_proto = -1;
 357   ccp->out.algorithm = -1;
 358   for (f = 0; f < NALGORITHMS; f++)
 359     if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
 360         !REJECTED(ccp, algorithm[f]->id) &&
 361         (*algorithm[f]->Usable)(fp)) {
 362
 363       if (!alloc)
 364         for (o = &ccp->out.opt; *o != NULL; o = &(*o)->next)
 365           if ((*o)->val.hdr.id == algorithm[f]->id && (*o)->algorithm == f)
 366             break;
 367
 368       if (alloc || *o == NULL) {
 369         *o = (struct ccp_opt *)malloc(sizeof(struct ccp_opt));
 370         (*o)->val.hdr.id = algorithm[f]->id;
 371         (*o)->val.hdr.len = 2;
 372         (*o)->next = NULL;
 373         (*o)->algorithm = f;
 374         (*algorithm[f]->o.OptInit)(fp->bundle, &(*o)->val, &ccp->cfg);
 375       }
 376
 377       if (cp + (*o)->val.hdr.len > buff + sizeof buff) {
 378         log_Printf(LogERROR, "%s: CCP REQ buffer overrun !\n", fp->link->name);
 379         break;
 380       }
 381       memcpy(cp, &(*o)->val, (*o)->val.hdr.len);
 382       cp += (*o)->val.hdr.len;
 383
 384       ccp->my_proto = (*o)->val.hdr.id;
 385       ccp->out.algorithm = f;
 386
 387       if (alloc)
 388         o = &(*o)->next;
 389     }
 390
 391   fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, cp - buff, MB_CCPOUT);
 392 }
 393
 394 void
 395 ccp_SendResetReq(struct fsm *fp)
 396 {
 397   /* We can't read our input - ask peer to reset */
 398   struct ccp *ccp = fsm2ccp(fp);
 399
 400   ccp->reset_sent = fp->reqid;
 401   ccp->last_reset = -1;
 402   fsm_Output(fp, CODE_RESETREQ, fp->reqid, NULL, 0, MB_CCPOUT);
 403 }
 404
 405 static void
 406 CcpSentTerminateReq(struct fsm *fp)
 407 {
 408   /* Term REQ just sent by FSM */
 409 }
 410
 411 static void
 412 CcpSendTerminateAck(struct fsm *fp, u_char id)
 413 {
 414   /* Send Term ACK please */
 415   fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_CCPOUT);
 416 }
 417
 418 static int
 419 CcpRecvResetReq(struct fsm *fp)
 420 {
 421   /* Got a reset REQ, reset outgoing dictionary */
 422   struct ccp *ccp = fsm2ccp(fp);
 423   if (ccp->out.state == NULL)
 424     return 1;
 425   return (*algorithm[ccp->out.algorithm]->o.Reset)(ccp->out.state);
 426 }
 427
 428 static void
 429 CcpLayerStart(struct fsm *fp)
 430 {
 431   /* We're about to start up ! */
 432   struct ccp *ccp = fsm2ccp(fp);
 433
 434   log_Printf(LogCCP, "%s: LayerStart.\n", fp->link->name);
 435   fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
 436 }
 437
 438 static void
 439 CcpLayerDown(struct fsm *fp)
 440 {
 441   /* About to come down */
 442   struct ccp *ccp = fsm2ccp(fp);
 443   struct ccp_opt *next;
 444
 445   log_Printf(LogCCP, "%s: LayerDown.\n", fp->link->name);
 446   if (ccp->in.state != NULL) {
 447     (*algorithm[ccp->in.algorithm]->i.Term)(ccp->in.state);
 448     ccp->in.state = NULL;
 449     ccp->in.algorithm = -1;
 450   }
 451   if (ccp->out.state != NULL) {
 452     (*algorithm[ccp->out.algorithm]->o.Term)(ccp->out.state);
 453     ccp->out.state = NULL;
 454     ccp->out.algorithm = -1;
 455   }
 456   ccp->his_reject = ccp->my_reject = 0;
 457
 458   while (ccp->out.opt) {
 459     next = ccp->out.opt->next;
 460     free(ccp->out.opt);
 461     ccp->out.opt = next;
 462   }
 463   ccp_Setup(ccp);
 464 }
 465
 466 static void
 467 CcpLayerFinish(struct fsm *fp)
 468 {
 469   /* We're now down */
 470   struct ccp *ccp = fsm2ccp(fp);
 471   struct ccp_opt *next;
 472
 473   log_Printf(LogCCP, "%s: LayerFinish.\n", fp->link->name);
 474
 475   /*
 476    * Nuke options that may be left over from sending a REQ but never
 477    * coming up.
 478    */
 479   while (ccp->out.opt) {
 480     next = ccp->out.opt->next;
 481     free(ccp->out.opt);
 482     ccp->out.opt = next;
 483   }
 484
 485   if (ccp_Required(ccp)) {
 486     if (fp->link->lcp.fsm.state == ST_OPENED)
 487       log_Printf(LogLCP, "%s: Closing due to CCP completion\n", fp->link->name);
 488     fsm_Close(&fp->link->lcp.fsm);
 489   }
 490 }
 491
 492 /*  Called when CCP has reached the OPEN state */
 493 static int
 494 CcpLayerUp(struct fsm *fp)
 495 {
 496   /* We're now up */
 497   struct ccp *ccp = fsm2ccp(fp);
 498   struct ccp_opt **o;
 499   int f, fail;
 500
 501   for (f = fail = 0; f < NALGORITHMS; f++)
 502     if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
 503         (*algorithm[f]->Required)(&ccp->fsm) &&
 504         (ccp->in.algorithm != f || ccp->out.algorithm != f)) {
 505       /* Blow it all away - we haven't negotiated a required algorithm */
 506       log_Printf(LogWARN, "%s: Failed to negotiate (required) %s\n",
 507                  fp->link->name, protoname(algorithm[f]->id));
 508       fail = 1;
 509     }
 510
 511   if (fail) {
 512     ccp->his_proto = ccp->my_proto = -1;
 513     fsm_Close(fp);
 514     fsm_Close(&fp->link->lcp.fsm);
 515     return 0;
 516   }
 517
 518   log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
 519
 520   if (ccp->in.state == NULL && ccp->in.algorithm >= 0 &&
 521       ccp->in.algorithm < NALGORITHMS) {
 522     ccp->in.state = (*algorithm[ccp->in.algorithm]->i.Init)
 523       (fp->bundle, &ccp->in.opt);
 524     if (ccp->in.state == NULL) {
 525       log_Printf(LogERROR, "%s: %s (in) initialisation failure\n",
 526                 fp->link->name, protoname(ccp->his_proto));
 527       ccp->his_proto = ccp->my_proto = -1;
 528       fsm_Close(fp);
 529       return 0;
 530     }
 531   }
 532
 533   o = &ccp->out.opt;
 534   for (f = 0; f < ccp->out.algorithm; f++)
 535     if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
 536       o = &(*o)->next;
 537
 538   if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
 539       ccp->out.algorithm < NALGORITHMS) {
 540     ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)
 541       (fp->bundle, &(*o)->val);
 542     if (ccp->out.state == NULL) {
 543       log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
 544                 fp->link->name, protoname(ccp->my_proto));
 545       ccp->his_proto = ccp->my_proto = -1;
 546       fsm_Close(fp);
 547       return 0;
 548     }
 549   }
 550
 551   fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
 552
 553   log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
 554             fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
 555             protoname(ccp->his_proto), ccp->his_proto);
 556
 557   return 1;
 558 }
 559
 560 static void
 561 CcpDecodeConfig(struct fsm *fp, u_char *cp, u_char *end, int mode_type,
 562                 struct fsm_decode *dec)
 563 {
 564   /* Deal with incoming data */
 565   struct ccp *ccp = fsm2ccp(fp);
 566   int f;
 567   const char *disp;
 568   struct fsm_opt *opt;
 569
 570   if (mode_type == MODE_REQ)
 571     ccp->in.algorithm = -1;     /* In case we've received two REQs in a row */
 572
 573   while (end - cp >= sizeof(opt->hdr)) {
 574     if ((opt = fsm_readopt(&cp)) == NULL)
 575       break;
 576
 577     for (f = NALGORITHMS-1; f > -1; f--)
 578       if (algorithm[f]->id == opt->hdr.id)
 579         break;
 580
 581     disp = f == -1 ? "" : (*algorithm[f]->Disp)(opt);
 582     if (disp == NULL)
 583       disp = "";
 584
 585     log_Printf(LogCCP, " %s[%d] %s\n", protoname(opt->hdr.id),
 586                opt->hdr.len, disp);
 587
 588     if (f == -1) {
 589       /* Don't understand that :-( */
 590       if (mode_type == MODE_REQ) {
 591         ccp->my_reject |= (1 << opt->hdr.id);
 592         fsm_rej(dec, opt);
 593       }
 594     } else {
 595       struct ccp_opt *o;
 596
 597       switch (mode_type) {
 598       case MODE_REQ:
 599         if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
 600             (*algorithm[f]->Usable)(fp) &&
 601             ccp->in.algorithm == -1) {
 602           memcpy(&ccp->in.opt, opt, opt->hdr.len);
 603           switch ((*algorithm[f]->i.Set)(fp->bundle, &ccp->in.opt, &ccp->cfg)) {
 604           case MODE_REJ:
 605             fsm_rej(dec, &ccp->in.opt);
 606             break;
 607           case MODE_NAK:
 608             fsm_nak(dec, &ccp->in.opt);
 609             break;
 610           case MODE_ACK:
 611             fsm_ack(dec, &ccp->in.opt);
 612             ccp->his_proto = opt->hdr.id;
 613             ccp->in.algorithm = f;              /* This one'll do :-) */
 614             break;
 615           }
 616         } else {
 617           fsm_rej(dec, opt);
 618         }
 619         break;
 620       case MODE_NAK:
 621         for (o = ccp->out.opt; o != NULL; o = o->next)
 622           if (o->val.hdr.id == opt->hdr.id)
 623             break;
 624         if (o == NULL)
 625           log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent"
 626                      " option\n", fp->link->name);
 627         else {
 628           memcpy(&o->val, opt, opt->hdr.len);
 629           if ((*algorithm[f]->o.Set)(fp->bundle, &o->val, &ccp->cfg) ==
 630               MODE_ACK)
 631             ccp->my_proto = algorithm[f]->id;
 632           else {
 633             ccp->his_reject |= (1 << opt->hdr.id);
 634             ccp->my_proto = -1;
 635             if (algorithm[f]->Required(fp)) {
 636               log_Printf(LogWARN, "%s: Cannot understand peers (required)"
 637                          " %s negotiation\n", fp->link->name,
 638                          protoname(algorithm[f]->id));
 639               fsm_Close(&fp->link->lcp.fsm);
 640             }
 641           }
 642         }
 643         break;
 644       case MODE_REJ:
 645         ccp->his_reject |= (1 << opt->hdr.id);
 646         ccp->my_proto = -1;
 647         if (algorithm[f]->Required(fp)) {
 648           log_Printf(LogWARN, "%s: Peer rejected (required) %s negotiation\n",
 649                      fp->link->name, protoname(algorithm[f]->id));
 650           fsm_Close(&fp->link->lcp.fsm);
 651         }
 652         break;
 653       }
 654     }
 655   }
 656
 657   if (mode_type != MODE_NOP) {
 658     fsm_opt_normalise(dec);
 659     if (dec->rejend != dec->rej || dec->nakend != dec->nak) {
 660       if (ccp->in.state == NULL) {
 661         ccp->his_proto = -1;
 662         ccp->in.algorithm = -1;
 663       }
 664     }
 665   }
 666 }
 667
 668 extern struct mbuf *
 669 ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
 670 {
 671   /* Got PROTO_CCP from link */
 672   m_settype(bp, MB_CCPIN);
 673   if (bundle_Phase(bundle) == PHASE_NETWORK)
 674     fsm_Input(&l->ccp.fsm, bp);
 675   else {
 676     if (bundle_Phase(bundle) < PHASE_NETWORK)
 677       log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
 678                  l->ccp.fsm.link->name, bundle_PhaseName(bundle));
 679     m_freem(bp);
 680   }
 681   return NULL;
 682 }
 683
 684 static void
 685 CcpRecvResetAck(struct fsm *fp, u_char id)
 686 {
 687   /* Got a reset ACK, reset incoming dictionary */
 688   struct ccp *ccp = fsm2ccp(fp);
 689
 690   if (ccp->reset_sent != -1) {
 691     if (id != ccp->reset_sent) {
 692       log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
 693                 " ignored\n", fp->link->name, id, ccp->reset_sent);
 694       return;
 695     }
 696     /* Whaddaya know - a correct reset ack */
 697   } else if (id == ccp->last_reset)
 698     log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
 699                fp->link->name);
 700   else {
 701     log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
 702                fp->link->name, id);
 703     return;
 704   }
 705
 706   ccp->last_reset = ccp->reset_sent;
 707   ccp->reset_sent = -1;
 708   if (ccp->in.state != NULL)
 709     (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
 710 }
 711
 712 static struct mbuf *
 713 ccp_LayerPush(struct bundle *b, struct link *l, struct mbuf *bp,
 714               int pri, u_short *proto)
 715 {
 716   if (PROTO_COMPRESSIBLE(*proto)) {
 717     if (l->ccp.fsm.state != ST_OPENED) {
 718       if (ccp_Required(&l->ccp)) {
 719         /* The NCP layer shouldn't have let this happen ! */
 720         log_Printf(LogERROR, "%s: Unexpected attempt to use an unopened and"
 721                    " required CCP layer\n", l->name);
 722         m_freem(bp);
 723         bp = NULL;
 724       }
 725     } else if (l->ccp.out.state != NULL) {
 726       bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
 727              (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
 728       switch (*proto) {
 729         case PROTO_ICOMPD:
 730           m_settype(bp, MB_ICOMPDOUT);
 731           break;
 732         case PROTO_COMPD:
 733           m_settype(bp, MB_COMPDOUT);
 734           break;
 735       }
 736     }
 737   }
 738
 739   return bp;
 740 }
 741
 742 static struct mbuf *
 743 ccp_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, u_short *proto)
 744 {
 745   /*
 746    * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
 747    * decompression routines so that the dictionary's updated
 748    */
 749   if (l->ccp.fsm.state == ST_OPENED) {
 750     if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
 751       /* Decompress incoming data */
 752       if (l->ccp.reset_sent != -1)
 753         /* Send another REQ and put the packet in the bit bucket */
 754         fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
 755                    MB_CCPOUT);
 756       else if (l->ccp.in.state != NULL) {
 757         bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
 758                (l->ccp.in.state, &l->ccp, proto, bp);
 759         switch (*proto) {
 760           case PROTO_ICOMPD:
 761             m_settype(bp, MB_ICOMPDIN);
 762             break;
 763           case PROTO_COMPD:
 764             m_settype(bp, MB_COMPDIN);
 765             break;
 766         }
 767         return bp;
 768       }
 769       m_freem(bp);
 770       bp = NULL;
 771     } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
 772       /* Add incoming Network Layer traffic to our dictionary */
 773       (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
 774         (l->ccp.in.state, &l->ccp, *proto, bp);
 775     }
 776   }
 777
 778   return bp;
 779 }
 780
 781 u_short
 782 ccp_Proto(struct ccp *ccp)
 783 {
 784   return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
 785          PROTO_COMPD : PROTO_ICOMPD;
 786 }
 787
 788 int
 789 ccp_SetOpenMode(struct ccp *ccp)
 790 {
 791   int f;
 792
 793   for (f = 0; f < CCP_NEG_TOTAL; f++)
 794     if (IsEnabled(ccp->cfg.neg[f])) {
 795       ccp->fsm.open_mode = 0;
 796       return 1;
 797     }
 798
 799   ccp->fsm.open_mode = OPEN_PASSIVE;    /* Go straight to ST_STOPPED ? */
 800
 801   for (f = 0; f < CCP_NEG_TOTAL; f++)
 802     if (IsAccepted(ccp->cfg.neg[f]))
 803       return 1;
 804
 805   return 0;                             /* No CCP at all */
 806 }
 807
 808 int
 809 ccp_DefaultUsable(struct fsm *fp)
 810 {
 811   return 1;
 812 }
 813
 814 int
 815 ccp_DefaultRequired(struct fsm *fp)
 816 {
 817   return 0;
 818 }
 819
 820 struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };