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  */
  30
  31 #include <sys/param.h>
  32 #include <netinet/in.h>
  33 #include <netinet/in_systm.h>
  34 #include <netinet/ip.h>
  35 #include <sys/socket.h>
  36 #include <sys/un.h>
  37
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>     /* memcpy() on some archs */
  42 #include <termios.h>
  43
  44 #include "layer.h"
  45 #include "defs.h"
  46 #include "command.h"
  47 #include "mbuf.h"
  48 #include "log.h"
  49 #include "timer.h"
  50 #include "fsm.h"
  51 #include "proto.h"
  52 #include "pred.h"
  53 #include "deflate.h"
  54 #include "throughput.h"
  55 #include "iplist.h"
  56 #include "slcompress.h"
  57 #include "lqr.h"
  58 #include "hdlc.h"
  59 #include "lcp.h"
  60 #include "ccp.h"
  61 #include "ncpaddr.h"
  62 #include "ipcp.h"
  63 #include "filter.h"
  64 #include "descriptor.h"
  65 #include "prompt.h"
  66 #include "link.h"
  67 #include "mp.h"
  68 #include "async.h"
  69 #include "physical.h"
  70 #ifndef NORADIUS
  71 #include "radius.h"
  72 #endif
  73 #ifndef NODES
  74 #include "mppe.h"
  75 #endif
  76 #include "ipv6cp.h"
  77 #include "ncp.h"
  78 #include "bundle.h"
  79
  80 static void CcpSendConfigReq(struct fsm *);
  81 static void CcpSentTerminateReq(struct fsm *);
  82 static void CcpSendTerminateAck(struct fsm *, u_char);
  83 static void CcpDecodeConfig(struct fsm *, u_char *, u_char *, int,
  84                             struct fsm_decode *);
  85 static void CcpLayerStart(struct fsm *);
  86 static void CcpLayerFinish(struct fsm *);
  87 static int CcpLayerUp(struct fsm *);
  88 static void CcpLayerDown(struct fsm *);
  89 static void CcpInitRestartCounter(struct fsm *, int);
  90 static int CcpRecvResetReq(struct fsm *);
  91 static void CcpRecvResetAck(struct fsm *, u_char);
  92
  93 static struct fsm_callbacks ccp_Callbacks = {
  94   CcpLayerUp,
  95   CcpLayerDown,
  96   CcpLayerStart,
  97   CcpLayerFinish,
  98   CcpInitRestartCounter,
  99   CcpSendConfigReq,
 100   CcpSentTerminateReq,
 101   CcpSendTerminateAck,
 102   CcpDecodeConfig,
 103   CcpRecvResetReq,
 104   CcpRecvResetAck
 105 };
 106
 107 static const char * const ccp_TimerNames[] =
 108   {"CCP restart", "CCP openmode", "CCP stopped"};
 109
 110 static const char *
 111 protoname(int proto)
 112 {
 113   static char const * const cftypes[] = {
 114     /* Check out the latest ``Compression Control Protocol'' rfc (1962) */
 115     "OUI",              /* 0: OUI */
 116     "PRED1",            /* 1: Predictor type 1 */
 117     "PRED2",            /* 2: Predictor type 2 */
 118     "PUDDLE",           /* 3: Puddle Jumber */
 119     NULL, NULL, NULL, NULL, NULL, NULL,
 120     NULL, NULL, NULL, NULL, NULL, NULL,
 121     "HWPPC",            /* 16: Hewlett-Packard PPC */
 122     "STAC",             /* 17: Stac Electronics LZS (rfc1974) */
 123     "MPPE",             /* 18: Microsoft PPC (rfc2118) and */
 124                         /*     Microsoft PPE (draft-ietf-pppext-mppe) */
 125     "GAND",             /* 19: Gandalf FZA (rfc1993) */
 126     "V42BIS",           /* 20: ARG->DATA.42bis compression */
 127     "BSD",              /* 21: BSD LZW Compress */
 128     NULL,
 129     "LZS-DCP",          /* 23: LZS-DCP Compression Protocol (rfc1967) */
 130     "MAGNALINK/DEFLATE",/* 24: Magnalink Variable Resource (rfc1975) */
 131                         /* 24: Deflate (according to pppd-2.3.*) */
 132     "DCE",              /* 25: Data Circuit-Terminating Equip (rfc1976) */
 133     "DEFLATE",          /* 26: Deflate (rfc1979) */
 134   };
 135
 136   if (proto < 0 || (unsigned)proto > NELEM(cftypes) ||
 137       cftypes[proto] == NULL) {
 138     if (proto == -1)
 139       return "none";
 140     return HexStr(proto, NULL, 0);
 141   }
 142
 143   return cftypes[proto];
 144 }
 145
 146 /* We support these algorithms, and Req them in the given order */
 147 static const struct ccp_algorithm * const algorithm[] = {
 148   &DeflateAlgorithm,
 149   &Pred1Algorithm,
 150   &PppdDeflateAlgorithm
 151 #ifndef NODES
 152   , &MPPEAlgorithm
 153 #endif
 154 };
 155
 156 #define NALGORITHMS NELEM(algorithm)
 157
 158 int
 159 ccp_ReportStatus(struct cmdargs const *arg)
 160 {
 161   struct ccp_opt **o;
 162   struct link *l;
 163   struct ccp *ccp;
 164   int f;
 165
 166   l = command_ChooseLink(arg);
 167   ccp = &l->ccp;
 168
 169   prompt_Printf(arg->prompt, "%s: %s [%s]\n", l->name, ccp->fsm.name,
 170                 State2Nam(ccp->fsm.state));
 171   if (ccp->fsm.state == ST_OPENED) {
 172     prompt_Printf(arg->prompt, " My protocol = %s, His protocol = %s\n",
 173                   protoname(ccp->my_proto), protoname(ccp->his_proto));
 174     prompt_Printf(arg->prompt, " Output: %ld --> %ld,  Input: %ld --> %ld\n",
 175                   ccp->uncompout, ccp->compout,
 176                   ccp->compin, ccp->uncompin);
 177   }
 178
 179   if (ccp->in.algorithm != -1)
 180     prompt_Printf(arg->prompt, "\n Input Options:  %s\n",
 181                   (*algorithm[ccp->in.algorithm]->Disp)(&ccp->in.opt));
 182
 183   if (ccp->out.algorithm != -1) {
 184     o = &ccp->out.opt;
 185     for (f = 0; f < ccp->out.algorithm; f++)
 186       if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
 187         o = &(*o)->next;
 188     prompt_Printf(arg->prompt, " Output Options: %s\n",
 189                   (*algorithm[ccp->out.algorithm]->Disp)(&(*o)->val));
 190   }
 191
 192   prompt_Printf(arg->prompt, "\n Defaults: ");
 193   prompt_Printf(arg->prompt, "FSM retry = %us, max %u Config"
 194                 " REQ%s, %u Term REQ%s\n", ccp->cfg.fsm.timeout,
 195                 ccp->cfg.fsm.maxreq, ccp->cfg.fsm.maxreq == 1 ? "" : "s",
 196                 ccp->cfg.fsm.maxtrm, ccp->cfg.fsm.maxtrm == 1 ? "" : "s");
 197   prompt_Printf(arg->prompt, "           deflate windows: ");
 198   prompt_Printf(arg->prompt, "incoming = %d, ", ccp->cfg.deflate.in.winsize);
 199   prompt_Printf(arg->prompt, "outgoing = %d\n", ccp->cfg.deflate.out.winsize);
 200 #ifndef NODES
 201   prompt_Printf(arg->prompt, "           MPPE: ");
 202   if (ccp->cfg.mppe.keybits)
 203     prompt_Printf(arg->prompt, "%d bits, ", ccp->cfg.mppe.keybits);
 204   else
 205     prompt_Printf(arg->prompt, "any bits, ");
 206   switch (ccp->cfg.mppe.state) {
 207   case MPPE_STATEFUL:
 208     prompt_Printf(arg->prompt, "stateful");
 209     break;
 210   case MPPE_STATELESS:
 211     prompt_Printf(arg->prompt, "stateless");
 212     break;
 213   case MPPE_ANYSTATE:
 214     prompt_Printf(arg->prompt, "any state");
 215     break;
 216   }
 217   prompt_Printf(arg->prompt, "%s\n",
 218                 ccp->cfg.mppe.required ? ", required" : "");
 219 #endif
 220
 221   prompt_Printf(arg->prompt, "\n           DEFLATE:    %s\n",
 222                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE]));
 223   prompt_Printf(arg->prompt, "           PREDICTOR1: %s\n",
 224                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_PRED1]));
 225   prompt_Printf(arg->prompt, "           DEFLATE24:  %s\n",
 226                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE24]));
 227 #ifndef NODES
 228   prompt_Printf(arg->prompt, "           MPPE:       %s\n",
 229                 command_ShowNegval(ccp->cfg.neg[CCP_NEG_MPPE]));
 230 #endif
 231   return 0;
 232 }
 233
 234 void
 235 ccp_SetupCallbacks(struct ccp *ccp)
 236 {
 237   ccp->fsm.fn = &ccp_Callbacks;
 238   ccp->fsm.FsmTimer.name = ccp_TimerNames[0];
 239   ccp->fsm.OpenTimer.name = ccp_TimerNames[1];
 240   ccp->fsm.StoppedTimer.name = ccp_TimerNames[2];
 241 }
 242
 243 void
 244 ccp_Init(struct ccp *ccp, struct bundle *bundle, struct link *l,
 245          const struct fsm_parent *parent)
 246 {
 247   /* Initialise ourselves */
 248
 249   fsm_Init(&ccp->fsm, "CCP", PROTO_CCP, 1, CCP_MAXCODE, LogCCP,
 250            bundle, l, parent, &ccp_Callbacks, ccp_TimerNames);
 251
 252   ccp->cfg.deflate.in.winsize = 0;
 253   ccp->cfg.deflate.out.winsize = 15;
 254   ccp->cfg.fsm.timeout = DEF_FSMRETRY;
 255   ccp->cfg.fsm.maxreq = DEF_FSMTRIES;
 256   ccp->cfg.fsm.maxtrm = DEF_FSMTRIES;
 257   ccp->cfg.neg[CCP_NEG_DEFLATE] = NEG_ENABLED|NEG_ACCEPTED;
 258   ccp->cfg.neg[CCP_NEG_PRED1] = NEG_ENABLED|NEG_ACCEPTED;
 259   ccp->cfg.neg[CCP_NEG_DEFLATE24] = 0;
 260 #ifndef NODES
 261   ccp->cfg.mppe.keybits = 0;
 262   ccp->cfg.mppe.state = MPPE_ANYSTATE;
 263   ccp->cfg.mppe.required = 0;
 264   ccp->cfg.neg[CCP_NEG_MPPE] = NEG_ENABLED|NEG_ACCEPTED;
 265 #endif
 266
 267   ccp_Setup(ccp);
 268 }
 269
 270 void
 271 ccp_Setup(struct ccp *ccp)
 272 {
 273   /* Set ourselves up for a startup */
 274   ccp->fsm.open_mode = 0;
 275   ccp->his_proto = ccp->my_proto = -1;
 276   ccp->reset_sent = ccp->last_reset = -1;
 277   ccp->in.algorithm = ccp->out.algorithm = -1;
 278   ccp->in.state = ccp->out.state = NULL;
 279   ccp->in.opt.hdr.id = -1;
 280   ccp->out.opt = NULL;
 281   ccp->his_reject = ccp->my_reject = 0;
 282   ccp->uncompout = ccp->compout = 0;
 283   ccp->uncompin = ccp->compin = 0;
 284 }
 285
 286 /*
 287  * Is ccp *REQUIRED* ?
 288  * We ask each of the configured ccp protocols if they're required and
 289  * return TRUE if they are.
 290  *
 291  * It's not possible for the peer to reject a required ccp protocol
 292  * without our state machine bringing the supporting lcp layer down.
 293  *
 294  * If ccp is required but not open, the NCP layer should not push
 295  * any data into the link.
 296  */
 297 int
 298 ccp_Required(struct ccp *ccp)
 299 {
 300   unsigned f;
 301
 302   for (f = 0; f < NALGORITHMS; f++)
 303     if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
 304         (*algorithm[f]->Required)(&ccp->fsm))
 305       return 1;
 306
 307   return 0;
 308 }
 309
 310 /*
 311  * Report whether it's possible to increase a packet's size after
 312  * compression (and by how much).
 313  */
 314 int
 315 ccp_MTUOverhead(struct ccp *ccp)
 316 {
 317   if (ccp->fsm.state == ST_OPENED && ccp->out.algorithm >= 0)
 318     return algorithm[ccp->out.algorithm]->o.MTUOverhead;
 319
 320   return 0;
 321 }
 322
 323 static void
 324 CcpInitRestartCounter(struct fsm *fp, int what)
 325 {
 326   /* Set fsm timer load */
 327   struct ccp *ccp = fsm2ccp(fp);
 328
 329   fp->FsmTimer.load = ccp->cfg.fsm.timeout * SECTICKS;
 330   switch (what) {
 331     case FSM_REQ_TIMER:
 332       fp->restart = ccp->cfg.fsm.maxreq;
 333       break;
 334     case FSM_TRM_TIMER:
 335       fp->restart = ccp->cfg.fsm.maxtrm;
 336       break;
 337     default:
 338       fp->restart = 1;
 339       break;
 340   }
 341 }
 342
 343 static void
 344 CcpSendConfigReq(struct fsm *fp)
 345 {
 346   /* Send config REQ please */
 347   struct ccp *ccp = fsm2ccp(fp);
 348   struct ccp_opt **o;
 349   u_char *cp, buff[100];
 350   unsigned f;
 351   int 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 == (int)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 __unused)
 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   unsigned 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 != (int)f || ccp->out.algorithm != (int)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 < (int)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   if (ccp->out.algorithm > 0)
 535     for (f = 0; f < (unsigned)ccp->out.algorithm; f++)
 536       if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
 537         o = &(*o)->next;
 538
 539   if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
 540       ccp->out.algorithm < (int)NALGORITHMS) {
 541     ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)
 542       (fp->bundle, &(*o)->val);
 543     if (ccp->out.state == NULL) {
 544       log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
 545                 fp->link->name, protoname(ccp->my_proto));
 546       ccp->his_proto = ccp->my_proto = -1;
 547       fsm_Close(fp);
 548       return 0;
 549     }
 550   }
 551
 552   fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
 553
 554   log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
 555             fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
 556             protoname(ccp->his_proto), ccp->his_proto);
 557
 558   return 1;
 559 }
 560
 561 static void
 562 CcpDecodeConfig(struct fsm *fp, u_char *cp, u_char *end, int mode_type,
 563                 struct fsm_decode *dec)
 564 {
 565   /* Deal with incoming data */
 566   struct ccp *ccp = fsm2ccp(fp);
 567   int f;
 568   const char *disp;
 569   struct fsm_opt *opt;
 570
 571   if (mode_type == MODE_REQ)
 572     ccp->in.algorithm = -1;     /* In case we've received two REQs in a row */
 573
 574   while (end >= cp + sizeof(opt->hdr)) {
 575     if ((opt = fsm_readopt(&cp)) == NULL)
 576       break;
 577
 578     for (f = NALGORITHMS-1; f > -1; f--)
 579       if (algorithm[f]->id == opt->hdr.id)
 580         break;
 581
 582     disp = f == -1 ? "" : (*algorithm[f]->Disp)(opt);
 583     if (disp == NULL)
 584       disp = "";
 585
 586     log_Printf(LogCCP, " %s[%d] %s\n", protoname(opt->hdr.id),
 587                opt->hdr.len, disp);
 588
 589     if (f == -1) {
 590       /* Don't understand that :-( */
 591       if (mode_type == MODE_REQ) {
 592         ccp->my_reject |= (1 << opt->hdr.id);
 593         fsm_rej(dec, opt);
 594       }
 595     } else {
 596       struct ccp_opt *o;
 597
 598       switch (mode_type) {
 599       case MODE_REQ:
 600         if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
 601             (*algorithm[f]->Usable)(fp) &&
 602             ccp->in.algorithm == -1) {
 603           memcpy(&ccp->in.opt, opt, opt->hdr.len);
 604           switch ((*algorithm[f]->i.Set)(fp->bundle, &ccp->in.opt, &ccp->cfg)) {
 605           case MODE_REJ:
 606             fsm_rej(dec, &ccp->in.opt);
 607             break;
 608           case MODE_NAK:
 609             fsm_nak(dec, &ccp->in.opt);
 610             break;
 611           case MODE_ACK:
 612             fsm_ack(dec, &ccp->in.opt);
 613             ccp->his_proto = opt->hdr.id;
 614             ccp->in.algorithm = (int)f;         /* This one'll do :-) */
 615             break;
 616           }
 617         } else {
 618           fsm_rej(dec, opt);
 619         }
 620         break;
 621       case MODE_NAK:
 622         for (o = ccp->out.opt; o != NULL; o = o->next)
 623           if (o->val.hdr.id == opt->hdr.id)
 624             break;
 625         if (o == NULL)
 626           log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent"
 627                      " option\n", fp->link->name);
 628         else {
 629           memcpy(&o->val, opt, opt->hdr.len);
 630           if ((*algorithm[f]->o.Set)(fp->bundle, &o->val, &ccp->cfg) ==
 631               MODE_ACK)
 632             ccp->my_proto = algorithm[f]->id;
 633           else {
 634             ccp->his_reject |= (1 << opt->hdr.id);
 635             ccp->my_proto = -1;
 636             if (algorithm[f]->Required(fp)) {
 637               log_Printf(LogWARN, "%s: Cannot understand peers (required)"
 638                          " %s negotiation\n", fp->link->name,
 639                          protoname(algorithm[f]->id));
 640               fsm_Close(&fp->link->lcp.fsm);
 641             }
 642           }
 643         }
 644         break;
 645       case MODE_REJ:
 646         ccp->his_reject |= (1 << opt->hdr.id);
 647         ccp->my_proto = -1;
 648         if (algorithm[f]->Required(fp)) {
 649           log_Printf(LogWARN, "%s: Peer rejected (required) %s negotiation\n",
 650                      fp->link->name, protoname(algorithm[f]->id));
 651           fsm_Close(&fp->link->lcp.fsm);
 652         }
 653         break;
 654       }
 655     }
 656   }
 657
 658   if (mode_type != MODE_NOP) {
 659     fsm_opt_normalise(dec);
 660     if (dec->rejend != dec->rej || dec->nakend != dec->nak) {
 661       if (ccp->in.state == NULL) {
 662         ccp->his_proto = -1;
 663         ccp->in.algorithm = -1;
 664       }
 665     }
 666   }
 667 }
 668
 669 extern struct mbuf *
 670 ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
 671 {
 672   /* Got PROTO_CCP from link */
 673   m_settype(bp, MB_CCPIN);
 674   if (bundle_Phase(bundle) == PHASE_NETWORK)
 675     fsm_Input(&l->ccp.fsm, bp);
 676   else {
 677     if (bundle_Phase(bundle) < PHASE_NETWORK)
 678       log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
 679                  l->ccp.fsm.link->name, bundle_PhaseName(bundle));
 680     m_freem(bp);
 681   }
 682   return NULL;
 683 }
 684
 685 static void
 686 CcpRecvResetAck(struct fsm *fp, u_char id)
 687 {
 688   /* Got a reset ACK, reset incoming dictionary */
 689   struct ccp *ccp = fsm2ccp(fp);
 690
 691   if (ccp->reset_sent != -1) {
 692     if (id != ccp->reset_sent) {
 693       log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
 694                 " ignored\n", fp->link->name, id, ccp->reset_sent);
 695       return;
 696     }
 697     /* Whaddaya know - a correct reset ack */
 698   } else if (id == ccp->last_reset)
 699     log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
 700                fp->link->name);
 701   else {
 702     log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
 703                fp->link->name, id);
 704     return;
 705   }
 706
 707   ccp->last_reset = ccp->reset_sent;
 708   ccp->reset_sent = -1;
 709   if (ccp->in.state != NULL)
 710     (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
 711 }
 712
 713 static struct mbuf *
 714 ccp_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
 715               int pri, u_short *proto)
 716 {
 717   if (PROTO_COMPRESSIBLE(*proto)) {
 718     if (l->ccp.fsm.state != ST_OPENED) {
 719       if (ccp_Required(&l->ccp)) {
 720         /* The NCP layer shouldn't have let this happen ! */
 721         log_Printf(LogERROR, "%s: Unexpected attempt to use an unopened and"
 722                    " required CCP layer\n", l->name);
 723         m_freem(bp);
 724         bp = NULL;
 725       }
 726     } else if (l->ccp.out.state != NULL) {
 727       bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
 728              (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
 729       switch (*proto) {
 730         case PROTO_ICOMPD:
 731           m_settype(bp, MB_ICOMPDOUT);
 732           break;
 733         case PROTO_COMPD:
 734           m_settype(bp, MB_COMPDOUT);
 735           break;
 736       }
 737     }
 738   }
 739
 740   return bp;
 741 }
 742
 743 static struct mbuf *
 744 ccp_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp,
 745               u_short *proto)
 746 {
 747   /*
 748    * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
 749    * decompression routines so that the dictionary's updated
 750    */
 751   if (l->ccp.fsm.state == ST_OPENED) {
 752     if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
 753       /* Decompress incoming data */
 754       if (l->ccp.reset_sent != -1)
 755         /* Send another REQ and put the packet in the bit bucket */
 756         fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
 757                    MB_CCPOUT);
 758       else if (l->ccp.in.state != NULL) {
 759         bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
 760                (l->ccp.in.state, &l->ccp, proto, bp);
 761         switch (*proto) {
 762           case PROTO_ICOMPD:
 763             m_settype(bp, MB_ICOMPDIN);
 764             break;
 765           case PROTO_COMPD:
 766             m_settype(bp, MB_COMPDIN);
 767             break;
 768         }
 769         return bp;
 770       }
 771       m_freem(bp);
 772       bp = NULL;
 773     } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
 774       /* Add incoming Network Layer traffic to our dictionary */
 775       (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
 776         (l->ccp.in.state, &l->ccp, *proto, bp);
 777     }
 778   }
 779
 780   return bp;
 781 }
 782
 783 u_short
 784 ccp_Proto(struct ccp *ccp)
 785 {
 786   return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
 787          PROTO_COMPD : PROTO_ICOMPD;
 788 }
 789
 790 int
 791 ccp_SetOpenMode(struct ccp *ccp)
 792 {
 793   int f;
 794
 795   for (f = 0; f < CCP_NEG_TOTAL; f++)
 796     if (IsEnabled(ccp->cfg.neg[f])) {
 797       ccp->fsm.open_mode = 0;
 798       return 1;
 799     }
 800
 801   ccp->fsm.open_mode = OPEN_PASSIVE;    /* Go straight to ST_STOPPED ? */
 802
 803   for (f = 0; f < CCP_NEG_TOTAL; f++)
 804     if (IsAccepted(ccp->cfg.neg[f]))
 805       return 1;
 806
 807   return 0;                             /* No CCP at all */
 808 }
 809
 810 int
 811 ccp_DefaultUsable(struct fsm *fp __unused)
 812 {
 813   return 1;
 814 }
 815
 816 int
 817 ccp_DefaultRequired(struct fsm *fp __unused)
 818 {
 819   return 0;
 820 }
 821
 822 struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };