ccp.c revision 47695 
1/*
2 *	   PPP Compression Control Protocol (CCP) Module
3 *
4 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
5 *
6 *   Copyright (C) 1994, Internet Initiative Japan, Inc. All rights reserverd.
7 *
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by the Internet Initiative Japan, Inc.  The name of the
14 * IIJ may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 * $Id: ccp.c,v 1.49 1999/05/12 09:48:43 brian Exp $
21 *
22 *	TODO:
23 *		o Support other compression protocols
24 */
25#include <sys/param.h>
26#include <netinet/in.h>
27#include <netinet/in_systm.h>
28#include <netinet/ip.h>
29#include <sys/un.h>
30
31#include <stdio.h>
32#include <stdlib.h>
33#include <string.h>
34#include <termios.h>
35
36#include "layer.h"
37#include "defs.h"
38#include "command.h"
39#include "mbuf.h"
40#include "log.h"
41#include "timer.h"
42#include "fsm.h"
43#include "proto.h"
44#include "lcp.h"
45#include "ccp.h"
46#include "pred.h"
47#include "deflate.h"
48#include "throughput.h"
49#include "iplist.h"
50#include "slcompress.h"
51#include "lqr.h"
52#include "hdlc.h"
53#include "ipcp.h"
54#include "filter.h"
55#include "descriptor.h"
56#include "prompt.h"
57#include "link.h"
58#include "mp.h"
59#include "async.h"
60#include "physical.h"
61#ifndef NORADIUS
62#include "radius.h"
63#endif
64#include "bundle.h"
65
66static void CcpSendConfigReq(struct fsm *);
67static void CcpSentTerminateReq(struct fsm *);
68static void CcpSendTerminateAck(struct fsm *, u_char);
69static void CcpDecodeConfig(struct fsm *, u_char *, int, int,
70                            struct fsm_decode *);
71static void CcpLayerStart(struct fsm *);
72static void CcpLayerFinish(struct fsm *);
73static int CcpLayerUp(struct fsm *);
74static void CcpLayerDown(struct fsm *);
75static void CcpInitRestartCounter(struct fsm *, int);
76static void CcpRecvResetReq(struct fsm *);
77static void CcpRecvResetAck(struct fsm *, u_char);
78
79static struct fsm_callbacks ccp_Callbacks = {
80  CcpLayerUp,
81  CcpLayerDown,
82  CcpLayerStart,
83  CcpLayerFinish,
84  CcpInitRestartCounter,
85  CcpSendConfigReq,
86  CcpSentTerminateReq,
87  CcpSendTerminateAck,
88  CcpDecodeConfig,
89  CcpRecvResetReq,
90  CcpRecvResetAck
91};
92
93static const char *ccp_TimerNames[] =
94  {"CCP restart", "CCP openmode", "CCP stopped"};
95
96static char const *cftypes[] = {
97  /* Check out the latest ``Compression Control Protocol'' rfc (rfc1962.txt) */
98  "OUI",		/* 0: OUI */
99  "PRED1",		/* 1: Predictor type 1 */
100  "PRED2",		/* 2: Predictor type 2 */
101  "PUDDLE",		/* 3: Puddle Jumber */
102  "???", "???", "???", "???", "???", "???",
103  "???", "???", "???", "???", "???", "???",
104  "HWPPC",		/* 16: Hewlett-Packard PPC */
105  "STAC",		/* 17: Stac Electronics LZS (rfc1974) */
106  "MPPC",		/* 18: Microsoft PPC (rfc2118) */
107  "GAND",		/* 19: Gandalf FZA (rfc1993) */
108  "V42BIS",		/* 20: ARG->DATA.42bis compression */
109  "BSD",		/* 21: BSD LZW Compress */
110  "???",
111  "LZS-DCP",		/* 23: LZS-DCP Compression Protocol (rfc1967) */
112  "MAGNALINK/DEFLATE",	/* 24: Magnalink Variable Resource (rfc1975) */
113			/* 24: Deflate (according to pppd-2.3.*) */
114  "DCE",		/* 25: Data Circuit-Terminating Equip (rfc1976) */
115  "DEFLATE",		/* 26: Deflate (rfc1979) */
116};
117
118#define NCFTYPES (sizeof cftypes/sizeof cftypes[0])
119
120static const char *
121protoname(int proto)
122{
123  if (proto < 0 || proto > NCFTYPES)
124    return "none";
125  return cftypes[proto];
126}
127
128/* We support these algorithms, and Req them in the given order */
129static const struct ccp_algorithm *algorithm[] = {
130  &DeflateAlgorithm,
131  &Pred1Algorithm,
132  &PppdDeflateAlgorithm
133};
134
135#define NALGORITHMS (sizeof algorithm/sizeof algorithm[0])
136
137int
138ccp_ReportStatus(struct cmdargs const *arg)
139{
140  struct link *l;
141  struct ccp *ccp;
142
143  l = command_ChooseLink(arg);
144  ccp = &l->ccp;
145
146  prompt_Printf(arg->prompt, "%s: %s [%s]\n", l->name, ccp->fsm.name,
147                State2Nam(ccp->fsm.state));
148  if (ccp->fsm.state == ST_OPENED) {
149    prompt_Printf(arg->prompt, " My protocol = %s, His protocol = %s\n",
150                  protoname(ccp->my_proto), protoname(ccp->his_proto));
151    prompt_Printf(arg->prompt, " Output: %ld --> %ld,  Input: %ld --> %ld\n",
152                  ccp->uncompout, ccp->compout,
153                  ccp->compin, ccp->uncompin);
154  }
155
156  prompt_Printf(arg->prompt, "\n Defaults: ");
157  prompt_Printf(arg->prompt, "FSM retry = %us, max %u Config"
158                " REQ%s, %u Term REQ%s\n", ccp->cfg.fsm.timeout,
159                ccp->cfg.fsm.maxreq, ccp->cfg.fsm.maxreq == 1 ? "" : "s",
160                ccp->cfg.fsm.maxtrm, ccp->cfg.fsm.maxtrm == 1 ? "" : "s");
161  prompt_Printf(arg->prompt, "           deflate windows: ");
162  prompt_Printf(arg->prompt, "incoming = %d, ", ccp->cfg.deflate.in.winsize);
163  prompt_Printf(arg->prompt, "outgoing = %d\n", ccp->cfg.deflate.out.winsize);
164  prompt_Printf(arg->prompt, "           DEFLATE:    %s\n",
165                command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE]));
166  prompt_Printf(arg->prompt, "           PREDICTOR1: %s\n",
167                command_ShowNegval(ccp->cfg.neg[CCP_NEG_PRED1]));
168  prompt_Printf(arg->prompt, "           DEFLATE24:  %s\n",
169                command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE24]));
170  return 0;
171}
172
173void
174ccp_SetupCallbacks(struct ccp *ccp)
175{
176  ccp->fsm.fn = &ccp_Callbacks;
177  ccp->fsm.FsmTimer.name = ccp_TimerNames[0];
178  ccp->fsm.OpenTimer.name = ccp_TimerNames[1];
179  ccp->fsm.StoppedTimer.name = ccp_TimerNames[2];
180}
181
182void
183ccp_Init(struct ccp *ccp, struct bundle *bundle, struct link *l,
184         const struct fsm_parent *parent)
185{
186  /* Initialise ourselves */
187
188  fsm_Init(&ccp->fsm, "CCP", PROTO_CCP, 1, CCP_MAXCODE, LogCCP,
189           bundle, l, parent, &ccp_Callbacks, ccp_TimerNames);
190
191  ccp->cfg.deflate.in.winsize = 0;
192  ccp->cfg.deflate.out.winsize = 15;
193  ccp->cfg.fsm.timeout = DEF_FSMRETRY;
194  ccp->cfg.fsm.maxreq = DEF_FSMTRIES;
195  ccp->cfg.fsm.maxtrm = DEF_FSMTRIES;
196  ccp->cfg.neg[CCP_NEG_DEFLATE] = NEG_ENABLED|NEG_ACCEPTED;
197  ccp->cfg.neg[CCP_NEG_PRED1] = NEG_ENABLED|NEG_ACCEPTED;
198  ccp->cfg.neg[CCP_NEG_DEFLATE24] = 0;
199
200  ccp_Setup(ccp);
201}
202
203void
204ccp_Setup(struct ccp *ccp)
205{
206  /* Set ourselves up for a startup */
207  ccp->fsm.open_mode = 0;
208  ccp->his_proto = ccp->my_proto = -1;
209  ccp->reset_sent = ccp->last_reset = -1;
210  ccp->in.algorithm = ccp->out.algorithm = -1;
211  ccp->in.state = ccp->out.state = NULL;
212  ccp->in.opt.id = -1;
213  ccp->out.opt = NULL;
214  ccp->his_reject = ccp->my_reject = 0;
215  ccp->uncompout = ccp->compout = 0;
216  ccp->uncompin = ccp->compin = 0;
217}
218
219static void
220CcpInitRestartCounter(struct fsm *fp, int what)
221{
222  /* Set fsm timer load */
223  struct ccp *ccp = fsm2ccp(fp);
224
225  fp->FsmTimer.load = ccp->cfg.fsm.timeout * SECTICKS;
226  switch (what) {
227    case FSM_REQ_TIMER:
228      fp->restart = ccp->cfg.fsm.maxreq;
229      break;
230    case FSM_TRM_TIMER:
231      fp->restart = ccp->cfg.fsm.maxtrm;
232      break;
233    default:
234      fp->restart = 1;
235      break;
236  }
237}
238
239static void
240CcpSendConfigReq(struct fsm *fp)
241{
242  /* Send config REQ please */
243  struct ccp *ccp = fsm2ccp(fp);
244  struct ccp_opt **o;
245  u_char *cp, buff[100];
246  int f, alloc;
247
248  cp = buff;
249  o = &ccp->out.opt;
250  alloc = ccp->his_reject == 0 && ccp->out.opt == NULL;
251  ccp->my_proto = -1;
252  ccp->out.algorithm = -1;
253  for (f = 0; f < NALGORITHMS; f++)
254    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
255        !REJECTED(ccp, algorithm[f]->id)) {
256
257      if (!alloc)
258        for (o = &ccp->out.opt; *o != NULL; o = &(*o)->next)
259          if ((*o)->val.id == algorithm[f]->id && (*o)->algorithm == f)
260            break;
261
262      if (alloc || *o == NULL) {
263        *o = (struct ccp_opt *)malloc(sizeof(struct ccp_opt));
264        (*o)->val.id = algorithm[f]->id;
265        (*o)->val.len = 2;
266        (*o)->next = NULL;
267        (*o)->algorithm = f;
268        (*algorithm[f]->o.OptInit)(&(*o)->val, &ccp->cfg);
269      }
270
271      if (cp + (*o)->val.len > buff + sizeof buff) {
272        log_Printf(LogERROR, "%s: CCP REQ buffer overrun !\n", fp->link->name);
273        break;
274      }
275      memcpy(cp, &(*o)->val, (*o)->val.len);
276      cp += (*o)->val.len;
277
278      ccp->my_proto = (*o)->val.id;
279      ccp->out.algorithm = f;
280
281      if (alloc)
282        o = &(*o)->next;
283    }
284
285  fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, cp - buff, MB_CCPOUT);
286}
287
288void
289ccp_SendResetReq(struct fsm *fp)
290{
291  /* We can't read our input - ask peer to reset */
292  struct ccp *ccp = fsm2ccp(fp);
293
294  ccp->reset_sent = fp->reqid;
295  ccp->last_reset = -1;
296  fsm_Output(fp, CODE_RESETREQ, fp->reqid, NULL, 0, MB_CCPOUT);
297}
298
299static void
300CcpSentTerminateReq(struct fsm *fp)
301{
302  /* Term REQ just sent by FSM */
303}
304
305static void
306CcpSendTerminateAck(struct fsm *fp, u_char id)
307{
308  /* Send Term ACK please */
309  fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_CCPOUT);
310}
311
312static void
313CcpRecvResetReq(struct fsm *fp)
314{
315  /* Got a reset REQ, reset outgoing dictionary */
316  struct ccp *ccp = fsm2ccp(fp);
317  if (ccp->out.state != NULL)
318    (*algorithm[ccp->out.algorithm]->o.Reset)(ccp->out.state);
319}
320
321static void
322CcpLayerStart(struct fsm *fp)
323{
324  /* We're about to start up ! */
325  struct ccp *ccp = fsm2ccp(fp);
326
327  log_Printf(LogCCP, "%s: LayerStart.\n", fp->link->name);
328  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
329}
330
331static void
332CcpLayerDown(struct fsm *fp)
333{
334  /* About to come down */
335  struct ccp *ccp = fsm2ccp(fp);
336  struct ccp_opt *next;
337
338  log_Printf(LogCCP, "%s: LayerDown.\n", fp->link->name);
339  if (ccp->in.state != NULL) {
340    (*algorithm[ccp->in.algorithm]->i.Term)(ccp->in.state);
341    ccp->in.state = NULL;
342    ccp->in.algorithm = -1;
343  }
344  if (ccp->out.state != NULL) {
345    (*algorithm[ccp->out.algorithm]->o.Term)(ccp->out.state);
346    ccp->out.state = NULL;
347    ccp->out.algorithm = -1;
348  }
349  ccp->his_reject = ccp->my_reject = 0;
350
351  while (ccp->out.opt) {
352    next = ccp->out.opt->next;
353    free(ccp->out.opt);
354    ccp->out.opt = next;
355  }
356  ccp_Setup(ccp);
357}
358
359static void
360CcpLayerFinish(struct fsm *fp)
361{
362  /* We're now down */
363  log_Printf(LogCCP, "%s: LayerFinish.\n", fp->link->name);
364}
365
366/*  Called when CCP has reached the OPEN state */
367static int
368CcpLayerUp(struct fsm *fp)
369{
370  /* We're now up */
371  struct ccp *ccp = fsm2ccp(fp);
372
373  log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
374
375  if (ccp->in.state == NULL && ccp->in.algorithm >= 0 &&
376      ccp->in.algorithm < NALGORITHMS) {
377    ccp->in.state = (*algorithm[ccp->in.algorithm]->i.Init)(&ccp->in.opt);
378    if (ccp->in.state == NULL) {
379      log_Printf(LogERROR, "%s: %s (in) initialisation failure\n",
380                fp->link->name, protoname(ccp->his_proto));
381      ccp->his_proto = ccp->my_proto = -1;
382      fsm_Close(fp);
383      return 0;
384    }
385  }
386
387  if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
388      ccp->out.algorithm < NALGORITHMS) {
389    ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)
390                       (&ccp->out.opt->val);
391    if (ccp->out.state == NULL) {
392      log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
393                fp->link->name, protoname(ccp->my_proto));
394      ccp->his_proto = ccp->my_proto = -1;
395      fsm_Close(fp);
396      return 0;
397    }
398  }
399
400  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
401
402  log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
403            fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
404            protoname(ccp->his_proto), ccp->his_proto);
405
406  return 1;
407}
408
409static void
410CcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
411                struct fsm_decode *dec)
412{
413  /* Deal with incoming data */
414  struct ccp *ccp = fsm2ccp(fp);
415  int type, length, f;
416  const char *end;
417
418  if (mode_type == MODE_REQ)
419    ccp->in.algorithm = -1;	/* In case we've received two REQs in a row */
420
421  while (plen >= sizeof(struct fsmconfig)) {
422    type = *cp;
423    length = cp[1];
424
425    if (length == 0) {
426      log_Printf(LogCCP, "%s: CCP size zero\n", fp->link->name);
427      break;
428    }
429
430    if (length > sizeof(struct lcp_opt)) {
431      length = sizeof(struct lcp_opt);
432      log_Printf(LogCCP, "%s: Warning: Truncating length to %d\n",
433                fp->link->name, length);
434    }
435
436    for (f = NALGORITHMS-1; f > -1; f--)
437      if (algorithm[f]->id == type)
438        break;
439
440    end = f == -1 ? "" : (*algorithm[f]->Disp)((struct lcp_opt *)cp);
441    if (end == NULL)
442      end = "";
443
444    if (type < NCFTYPES)
445      log_Printf(LogCCP, " %s[%d] %s\n", cftypes[type], length, end);
446    else
447      log_Printf(LogCCP, " ???[%d] %s\n", length, end);
448
449    if (f == -1) {
450      /* Don't understand that :-( */
451      if (mode_type == MODE_REQ) {
452        ccp->my_reject |= (1 << type);
453        memcpy(dec->rejend, cp, length);
454        dec->rejend += length;
455      }
456    } else {
457      struct ccp_opt *o;
458
459      switch (mode_type) {
460      case MODE_REQ:
461	if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
462            ccp->in.algorithm == -1) {
463	  memcpy(&ccp->in.opt, cp, length);
464          switch ((*algorithm[f]->i.Set)(&ccp->in.opt, &ccp->cfg)) {
465          case MODE_REJ:
466	    memcpy(dec->rejend, &ccp->in.opt, ccp->in.opt.len);
467	    dec->rejend += ccp->in.opt.len;
468            break;
469          case MODE_NAK:
470	    memcpy(dec->nakend, &ccp->in.opt, ccp->in.opt.len);
471	    dec->nakend += ccp->in.opt.len;
472            break;
473          case MODE_ACK:
474	    memcpy(dec->ackend, cp, length);
475	    dec->ackend += length;
476	    ccp->his_proto = type;
477            ccp->in.algorithm = f;		/* This one'll do :-) */
478            break;
479          }
480	} else {
481	  memcpy(dec->rejend, cp, length);
482	  dec->rejend += length;
483	}
484	break;
485      case MODE_NAK:
486        for (o = ccp->out.opt; o != NULL; o = o->next)
487          if (o->val.id == cp[0])
488            break;
489        if (o == NULL)
490          log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent option\n",
491                    fp->link->name);
492        else {
493	  memcpy(&o->val, cp, length);
494          if ((*algorithm[f]->o.Set)(&o->val) == MODE_ACK)
495            ccp->my_proto = algorithm[f]->id;
496          else {
497	    ccp->his_reject |= (1 << type);
498	    ccp->my_proto = -1;
499          }
500        }
501        break;
502      case MODE_REJ:
503	ccp->his_reject |= (1 << type);
504	ccp->my_proto = -1;
505	break;
506      }
507    }
508
509    plen -= cp[1];
510    cp += cp[1];
511  }
512
513  if (mode_type != MODE_NOP) {
514    if (dec->rejend != dec->rej) {
515      /* rejects are preferred */
516      dec->ackend = dec->ack;
517      dec->nakend = dec->nak;
518      if (ccp->in.state == NULL) {
519        ccp->his_proto = -1;
520        ccp->in.algorithm = -1;
521      }
522    } else if (dec->nakend != dec->nak) {
523      /* then NAKs */
524      dec->ackend = dec->ack;
525      if (ccp->in.state == NULL) {
526        ccp->his_proto = -1;
527        ccp->in.algorithm = -1;
528      }
529    }
530  }
531}
532
533extern struct mbuf *
534ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
535{
536  /* Got PROTO_CCP from link */
537  mbuf_SetType(bp, MB_CCPIN);
538  if (bundle_Phase(bundle) == PHASE_NETWORK)
539    fsm_Input(&l->ccp.fsm, bp);
540  else {
541    if (bundle_Phase(bundle) < PHASE_NETWORK)
542      log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
543                 l->ccp.fsm.link->name, bundle_PhaseName(bundle));
544    mbuf_Free(bp);
545  }
546  return NULL;
547}
548
549static void
550CcpRecvResetAck(struct fsm *fp, u_char id)
551{
552  /* Got a reset ACK, reset incoming dictionary */
553  struct ccp *ccp = fsm2ccp(fp);
554
555  if (ccp->reset_sent != -1) {
556    if (id != ccp->reset_sent) {
557      log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
558                " ignored\n", fp->link->name, id, ccp->reset_sent);
559      return;
560    }
561    /* Whaddaya know - a correct reset ack */
562  } else if (id == ccp->last_reset)
563    log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
564               fp->link->name);
565  else {
566    log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
567               fp->link->name, id);
568    return;
569  }
570
571  ccp->last_reset = ccp->reset_sent;
572  ccp->reset_sent = -1;
573  if (ccp->in.state != NULL)
574    (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
575}
576
577static struct mbuf *
578ccp_LayerPush(struct bundle *b, struct link *l, struct mbuf *bp,
579              int pri, u_short *proto)
580{
581  if (PROTO_COMPRESSIBLE(*proto) && l->ccp.fsm.state == ST_OPENED &&
582      l->ccp.out.state != NULL) {
583    bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
584           (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
585    switch (*proto) {
586      case PROTO_ICOMPD:
587        mbuf_SetType(bp, MB_ICOMPDOUT);
588        break;
589      case PROTO_COMPD:
590        mbuf_SetType(bp, MB_COMPDOUT);
591        break;
592    }
593  }
594
595  return bp;
596}
597
598static struct mbuf *
599ccp_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, u_short *proto)
600{
601  /*
602   * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
603   * decompression routines so that the dictionary's updated
604   */
605  if (l->ccp.fsm.state == ST_OPENED) {
606    if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
607      log_Printf(LogDEBUG, "ccp_LayerPull: PROTO_%sCOMPDP -> PROTO_IP\n",
608                 *proto == PROTO_ICOMPD ? "I" : "");
609      /* Decompress incoming data */
610      if (l->ccp.reset_sent != -1)
611        /* Send another REQ and put the packet in the bit bucket */
612        fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
613                   MB_CCPOUT);
614      else if (l->ccp.in.state != NULL) {
615        bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
616               (l->ccp.in.state, &l->ccp, proto, bp);
617        switch (*proto) {
618          case PROTO_ICOMPD:
619            mbuf_SetType(bp, MB_ICOMPDIN);
620            break;
621          case PROTO_COMPD:
622            mbuf_SetType(bp, MB_COMPDIN);
623            break;
624        }
625        return bp;
626      }
627      mbuf_Free(bp);
628      bp = NULL;
629    } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
630      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet (dict only)\n");
631      /* Add incoming Network Layer traffic to our dictionary */
632      (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
633        (l->ccp.in.state, &l->ccp, *proto, bp);
634    } else
635      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet\n");
636  }
637
638  return bp;
639}
640
641u_short
642ccp_Proto(struct ccp *ccp)
643{
644  return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
645         PROTO_COMPD : PROTO_ICOMPD;
646}
647
648int
649ccp_SetOpenMode(struct ccp *ccp)
650{
651  int f;
652
653  for (f = 0; f < CCP_NEG_TOTAL; f++)
654    if (IsEnabled(ccp->cfg.neg[f])) {
655      ccp->fsm.open_mode = 0;
656      return 1;
657    }
658
659  ccp->fsm.open_mode = OPEN_PASSIVE;	/* Go straight to ST_STOPPED ? */
660
661  for (f = 0; f < CCP_NEG_TOTAL; f++)
662    if (IsAccepted(ccp->cfg.neg[f]))
663      return 1;
664
665  return 0;				/* No CCP at all */
666}
667
668struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };
669