ccp.c revision 67910 
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 * $FreeBSD: head/usr.sbin/ppp/ccp.c 67910 2000-10-30 00:15:04Z brian $
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>	/* memcpy() on some archs */
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 "pred.h"
45#include "deflate.h"
46#include "throughput.h"
47#include "iplist.h"
48#include "slcompress.h"
49#include "lqr.h"
50#include "hdlc.h"
51#include "lcp.h"
52#include "ccp.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#ifdef HAVE_DES
65#include "mppe.h"
66#endif
67#include "bundle.h"
68
69static void CcpSendConfigReq(struct fsm *);
70static void CcpSentTerminateReq(struct fsm *);
71static void CcpSendTerminateAck(struct fsm *, u_char);
72static void CcpDecodeConfig(struct fsm *, u_char *, int, int,
73                            struct fsm_decode *);
74static void CcpLayerStart(struct fsm *);
75static void CcpLayerFinish(struct fsm *);
76static int CcpLayerUp(struct fsm *);
77static void CcpLayerDown(struct fsm *);
78static void CcpInitRestartCounter(struct fsm *, int);
79static void CcpRecvResetReq(struct fsm *);
80static void CcpRecvResetAck(struct fsm *, u_char);
81
82static struct fsm_callbacks ccp_Callbacks = {
83  CcpLayerUp,
84  CcpLayerDown,
85  CcpLayerStart,
86  CcpLayerFinish,
87  CcpInitRestartCounter,
88  CcpSendConfigReq,
89  CcpSentTerminateReq,
90  CcpSendTerminateAck,
91  CcpDecodeConfig,
92  CcpRecvResetReq,
93  CcpRecvResetAck
94};
95
96static const char * const ccp_TimerNames[] =
97  {"CCP restart", "CCP openmode", "CCP stopped"};
98
99static const char *
100protoname(int proto)
101{
102  static char const * const cftypes[] = {
103    /* Check out the latest ``Compression Control Protocol'' rfc (1962) */
104    "OUI",		/* 0: OUI */
105    "PRED1",		/* 1: Predictor type 1 */
106    "PRED2",		/* 2: Predictor type 2 */
107    "PUDDLE",		/* 3: Puddle Jumber */
108    NULL, NULL, NULL, NULL, NULL, NULL,
109    NULL, NULL, NULL, NULL, NULL, NULL,
110    "HWPPC",		/* 16: Hewlett-Packard PPC */
111    "STAC",		/* 17: Stac Electronics LZS (rfc1974) */
112    "MPPE",		/* 18: Microsoft PPC (rfc2118) and */
113			/*     Microsoft PPE (draft-ietf-pppext-mppe) */
114    "GAND",		/* 19: Gandalf FZA (rfc1993) */
115    "V42BIS",		/* 20: ARG->DATA.42bis compression */
116    "BSD",		/* 21: BSD LZW Compress */
117    NULL,
118    "LZS-DCP",		/* 23: LZS-DCP Compression Protocol (rfc1967) */
119    "MAGNALINK/DEFLATE",/* 24: Magnalink Variable Resource (rfc1975) */
120			/* 24: Deflate (according to pppd-2.3.*) */
121    "DCE",		/* 25: Data Circuit-Terminating Equip (rfc1976) */
122    "DEFLATE",		/* 26: Deflate (rfc1979) */
123  };
124
125  if (proto < 0 || proto > sizeof cftypes / sizeof *cftypes ||
126      cftypes[proto] == NULL)
127    return HexStr(proto, NULL, 0);
128
129  return cftypes[proto];
130}
131
132/* We support these algorithms, and Req them in the given order */
133static const struct ccp_algorithm * const algorithm[] = {
134  &DeflateAlgorithm,
135  &Pred1Algorithm,
136  &PppdDeflateAlgorithm
137#ifdef HAVE_DES
138  , &MPPEAlgorithm
139#endif
140};
141
142#define NALGORITHMS (sizeof algorithm/sizeof algorithm[0])
143
144int
145ccp_ReportStatus(struct cmdargs const *arg)
146{
147  struct link *l;
148  struct ccp *ccp;
149
150  l = command_ChooseLink(arg);
151  ccp = &l->ccp;
152
153  prompt_Printf(arg->prompt, "%s: %s [%s]\n", l->name, ccp->fsm.name,
154                State2Nam(ccp->fsm.state));
155  if (ccp->fsm.state == ST_OPENED) {
156    prompt_Printf(arg->prompt, " My protocol = %s, His protocol = %s\n",
157                  protoname(ccp->my_proto), protoname(ccp->his_proto));
158    prompt_Printf(arg->prompt, " Output: %ld --> %ld,  Input: %ld --> %ld\n",
159                  ccp->uncompout, ccp->compout,
160                  ccp->compin, ccp->uncompin);
161  }
162
163  prompt_Printf(arg->prompt, "\n Defaults: ");
164  prompt_Printf(arg->prompt, "FSM retry = %us, max %u Config"
165                " REQ%s, %u Term REQ%s\n", ccp->cfg.fsm.timeout,
166                ccp->cfg.fsm.maxreq, ccp->cfg.fsm.maxreq == 1 ? "" : "s",
167                ccp->cfg.fsm.maxtrm, ccp->cfg.fsm.maxtrm == 1 ? "" : "s");
168  prompt_Printf(arg->prompt, "           deflate windows: ");
169  prompt_Printf(arg->prompt, "incoming = %d, ", ccp->cfg.deflate.in.winsize);
170  prompt_Printf(arg->prompt, "outgoing = %d\n", ccp->cfg.deflate.out.winsize);
171  prompt_Printf(arg->prompt, "           DEFLATE:    %s\n",
172                command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE]));
173  prompt_Printf(arg->prompt, "           PREDICTOR1: %s\n",
174                command_ShowNegval(ccp->cfg.neg[CCP_NEG_PRED1]));
175  prompt_Printf(arg->prompt, "           DEFLATE24:  %s\n",
176                command_ShowNegval(ccp->cfg.neg[CCP_NEG_DEFLATE24]));
177#ifdef HAVE_DES
178  prompt_Printf(arg->prompt, "           MPPE:       %s\n",
179                command_ShowNegval(ccp->cfg.neg[CCP_NEG_MPPE]));
180  prompt_Printf(arg->prompt, "Key Size = %d-bits\n", ccp->cfg.mppe.keybits);
181#endif
182  return 0;
183}
184
185void
186ccp_SetupCallbacks(struct ccp *ccp)
187{
188  ccp->fsm.fn = &ccp_Callbacks;
189  ccp->fsm.FsmTimer.name = ccp_TimerNames[0];
190  ccp->fsm.OpenTimer.name = ccp_TimerNames[1];
191  ccp->fsm.StoppedTimer.name = ccp_TimerNames[2];
192}
193
194void
195ccp_Init(struct ccp *ccp, struct bundle *bundle, struct link *l,
196         const struct fsm_parent *parent)
197{
198  /* Initialise ourselves */
199
200  fsm_Init(&ccp->fsm, "CCP", PROTO_CCP, 1, CCP_MAXCODE, LogCCP,
201           bundle, l, parent, &ccp_Callbacks, ccp_TimerNames);
202
203  ccp->cfg.deflate.in.winsize = 0;
204  ccp->cfg.deflate.out.winsize = 15;
205  ccp->cfg.fsm.timeout = DEF_FSMRETRY;
206  ccp->cfg.fsm.maxreq = DEF_FSMTRIES;
207  ccp->cfg.fsm.maxtrm = DEF_FSMTRIES;
208  ccp->cfg.neg[CCP_NEG_DEFLATE] = NEG_ENABLED|NEG_ACCEPTED;
209  ccp->cfg.neg[CCP_NEG_PRED1] = NEG_ENABLED|NEG_ACCEPTED;
210  ccp->cfg.neg[CCP_NEG_DEFLATE24] = 0;
211#ifdef HAVE_DES
212  ccp->cfg.mppe.keybits = 128;
213  ccp->cfg.neg[CCP_NEG_MPPE] = 0;
214#endif
215
216  ccp_Setup(ccp);
217}
218
219void
220ccp_Setup(struct ccp *ccp)
221{
222  /* Set ourselves up for a startup */
223  ccp->fsm.open_mode = 0;
224  ccp->his_proto = ccp->my_proto = -1;
225  ccp->reset_sent = ccp->last_reset = -1;
226  ccp->in.algorithm = ccp->out.algorithm = -1;
227  ccp->in.state = ccp->out.state = NULL;
228  ccp->in.opt.id = -1;
229  ccp->out.opt = NULL;
230  ccp->his_reject = ccp->my_reject = 0;
231  ccp->uncompout = ccp->compout = 0;
232  ccp->uncompin = ccp->compin = 0;
233}
234
235static void
236CcpInitRestartCounter(struct fsm *fp, int what)
237{
238  /* Set fsm timer load */
239  struct ccp *ccp = fsm2ccp(fp);
240
241  fp->FsmTimer.load = ccp->cfg.fsm.timeout * SECTICKS;
242  switch (what) {
243    case FSM_REQ_TIMER:
244      fp->restart = ccp->cfg.fsm.maxreq;
245      break;
246    case FSM_TRM_TIMER:
247      fp->restart = ccp->cfg.fsm.maxtrm;
248      break;
249    default:
250      fp->restart = 1;
251      break;
252  }
253}
254
255static void
256CcpSendConfigReq(struct fsm *fp)
257{
258  /* Send config REQ please */
259  struct ccp *ccp = fsm2ccp(fp);
260  struct ccp_opt **o;
261  u_char *cp, buff[100];
262  int f, alloc;
263
264  cp = buff;
265  o = &ccp->out.opt;
266  alloc = ccp->his_reject == 0 && ccp->out.opt == NULL;
267  ccp->my_proto = -1;
268  ccp->out.algorithm = -1;
269  for (f = 0; f < NALGORITHMS; f++)
270    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
271        !REJECTED(ccp, algorithm[f]->id)) {
272
273      if (!alloc)
274        for (o = &ccp->out.opt; *o != NULL; o = &(*o)->next)
275          if ((*o)->val.id == algorithm[f]->id && (*o)->algorithm == f)
276            break;
277
278      if (alloc || *o == NULL) {
279        *o = (struct ccp_opt *)malloc(sizeof(struct ccp_opt));
280        (*o)->val.id = algorithm[f]->id;
281        (*o)->val.len = 2;
282        (*o)->next = NULL;
283        (*o)->algorithm = f;
284        (*algorithm[f]->o.OptInit)(&(*o)->val, &ccp->cfg);
285      }
286
287      if (cp + (*o)->val.len > buff + sizeof buff) {
288        log_Printf(LogERROR, "%s: CCP REQ buffer overrun !\n", fp->link->name);
289        break;
290      }
291      memcpy(cp, &(*o)->val, (*o)->val.len);
292      cp += (*o)->val.len;
293
294      ccp->my_proto = (*o)->val.id;
295      ccp->out.algorithm = f;
296
297      if (alloc)
298        o = &(*o)->next;
299    }
300
301  fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, cp - buff, MB_CCPOUT);
302}
303
304void
305ccp_SendResetReq(struct fsm *fp)
306{
307  /* We can't read our input - ask peer to reset */
308  struct ccp *ccp = fsm2ccp(fp);
309
310  ccp->reset_sent = fp->reqid;
311  ccp->last_reset = -1;
312  fsm_Output(fp, CODE_RESETREQ, fp->reqid, NULL, 0, MB_CCPOUT);
313}
314
315static void
316CcpSentTerminateReq(struct fsm *fp)
317{
318  /* Term REQ just sent by FSM */
319}
320
321static void
322CcpSendTerminateAck(struct fsm *fp, u_char id)
323{
324  /* Send Term ACK please */
325  fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_CCPOUT);
326}
327
328static void
329CcpRecvResetReq(struct fsm *fp)
330{
331  /* Got a reset REQ, reset outgoing dictionary */
332  struct ccp *ccp = fsm2ccp(fp);
333  if (ccp->out.state != NULL)
334    (*algorithm[ccp->out.algorithm]->o.Reset)(ccp->out.state);
335}
336
337static void
338CcpLayerStart(struct fsm *fp)
339{
340  /* We're about to start up ! */
341  struct ccp *ccp = fsm2ccp(fp);
342
343  log_Printf(LogCCP, "%s: LayerStart.\n", fp->link->name);
344  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
345}
346
347static void
348CcpLayerDown(struct fsm *fp)
349{
350  /* About to come down */
351  struct ccp *ccp = fsm2ccp(fp);
352  struct ccp_opt *next;
353
354  log_Printf(LogCCP, "%s: LayerDown.\n", fp->link->name);
355  if (ccp->in.state != NULL) {
356    (*algorithm[ccp->in.algorithm]->i.Term)(ccp->in.state);
357    ccp->in.state = NULL;
358    ccp->in.algorithm = -1;
359  }
360  if (ccp->out.state != NULL) {
361    (*algorithm[ccp->out.algorithm]->o.Term)(ccp->out.state);
362    ccp->out.state = NULL;
363    ccp->out.algorithm = -1;
364  }
365  ccp->his_reject = ccp->my_reject = 0;
366
367  while (ccp->out.opt) {
368    next = ccp->out.opt->next;
369    free(ccp->out.opt);
370    ccp->out.opt = next;
371  }
372  ccp_Setup(ccp);
373}
374
375static void
376CcpLayerFinish(struct fsm *fp)
377{
378  /* We're now down */
379  log_Printf(LogCCP, "%s: LayerFinish.\n", fp->link->name);
380}
381
382/*  Called when CCP has reached the OPEN state */
383static int
384CcpLayerUp(struct fsm *fp)
385{
386  /* We're now up */
387  struct ccp *ccp = fsm2ccp(fp);
388
389  log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
390
391  if (ccp->in.state == NULL && ccp->in.algorithm >= 0 &&
392      ccp->in.algorithm < NALGORITHMS) {
393    ccp->in.state = (*algorithm[ccp->in.algorithm]->i.Init)(&ccp->in.opt);
394    if (ccp->in.state == NULL) {
395      log_Printf(LogERROR, "%s: %s (in) initialisation failure\n",
396                fp->link->name, protoname(ccp->his_proto));
397      ccp->his_proto = ccp->my_proto = -1;
398      fsm_Close(fp);
399      return 0;
400    }
401  }
402
403  if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
404      ccp->out.algorithm < NALGORITHMS) {
405    ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)
406                       (&ccp->out.opt->val);
407    if (ccp->out.state == NULL) {
408      log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
409                fp->link->name, protoname(ccp->my_proto));
410      ccp->his_proto = ccp->my_proto = -1;
411      fsm_Close(fp);
412      return 0;
413    }
414  }
415
416  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
417
418  log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
419            fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
420            protoname(ccp->his_proto), ccp->his_proto);
421
422  return 1;
423}
424
425static void
426CcpDecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
427                struct fsm_decode *dec)
428{
429  /* Deal with incoming data */
430  struct ccp *ccp = fsm2ccp(fp);
431  int type, length, f;
432  const char *end;
433
434  if (mode_type == MODE_REQ)
435    ccp->in.algorithm = -1;	/* In case we've received two REQs in a row */
436
437  while (plen >= sizeof(struct fsmconfig)) {
438    type = *cp;
439    length = cp[1];
440
441    if (length == 0) {
442      log_Printf(LogCCP, "%s: CCP size zero\n", fp->link->name);
443      break;
444    }
445
446    if (length > sizeof(struct lcp_opt)) {
447      length = sizeof(struct lcp_opt);
448      log_Printf(LogCCP, "%s: Warning: Truncating length to %d\n",
449                fp->link->name, length);
450    }
451
452    for (f = NALGORITHMS-1; f > -1; f--)
453      if (algorithm[f]->id == type)
454        break;
455
456    end = f == -1 ? "" : (*algorithm[f]->Disp)((struct lcp_opt *)cp);
457    if (end == NULL)
458      end = "";
459
460    log_Printf(LogCCP, " %s[%d] %s\n", protoname(type), length, end);
461
462    if (f == -1) {
463      /* Don't understand that :-( */
464      if (mode_type == MODE_REQ) {
465        ccp->my_reject |= (1 << type);
466        memcpy(dec->rejend, cp, length);
467        dec->rejend += length;
468      }
469    } else {
470      struct ccp_opt *o;
471
472      switch (mode_type) {
473      case MODE_REQ:
474	if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
475            ccp->in.algorithm == -1) {
476	  memcpy(&ccp->in.opt, cp, length);
477          switch ((*algorithm[f]->i.Set)(&ccp->in.opt, &ccp->cfg)) {
478          case MODE_REJ:
479	    memcpy(dec->rejend, &ccp->in.opt, ccp->in.opt.len);
480	    dec->rejend += ccp->in.opt.len;
481            break;
482          case MODE_NAK:
483	    memcpy(dec->nakend, &ccp->in.opt, ccp->in.opt.len);
484	    dec->nakend += ccp->in.opt.len;
485            break;
486          case MODE_ACK:
487	    memcpy(dec->ackend, cp, length);
488	    dec->ackend += length;
489	    ccp->his_proto = type;
490            ccp->in.algorithm = f;		/* This one'll do :-) */
491            break;
492          }
493	} else {
494	  memcpy(dec->rejend, cp, length);
495	  dec->rejend += length;
496	}
497	break;
498      case MODE_NAK:
499        for (o = ccp->out.opt; o != NULL; o = o->next)
500          if (o->val.id == cp[0])
501            break;
502        if (o == NULL)
503          log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent option\n",
504                    fp->link->name);
505        else {
506	  memcpy(&o->val, cp, length);
507          if ((*algorithm[f]->o.Set)(&o->val) == MODE_ACK)
508            ccp->my_proto = algorithm[f]->id;
509          else {
510	    ccp->his_reject |= (1 << type);
511	    ccp->my_proto = -1;
512          }
513        }
514        break;
515      case MODE_REJ:
516	ccp->his_reject |= (1 << type);
517	ccp->my_proto = -1;
518	break;
519      }
520    }
521
522    plen -= cp[1];
523    cp += cp[1];
524  }
525
526  if (mode_type != MODE_NOP) {
527    if (dec->rejend != dec->rej) {
528      /* rejects are preferred */
529      dec->ackend = dec->ack;
530      dec->nakend = dec->nak;
531      if (ccp->in.state == NULL) {
532        ccp->his_proto = -1;
533        ccp->in.algorithm = -1;
534      }
535    } else if (dec->nakend != dec->nak) {
536      /* then NAKs */
537      dec->ackend = dec->ack;
538      if (ccp->in.state == NULL) {
539        ccp->his_proto = -1;
540        ccp->in.algorithm = -1;
541      }
542    }
543  }
544}
545
546extern struct mbuf *
547ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
548{
549  /* Got PROTO_CCP from link */
550  m_settype(bp, MB_CCPIN);
551  if (bundle_Phase(bundle) == PHASE_NETWORK)
552    fsm_Input(&l->ccp.fsm, bp);
553  else {
554    if (bundle_Phase(bundle) < PHASE_NETWORK)
555      log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
556                 l->ccp.fsm.link->name, bundle_PhaseName(bundle));
557    m_freem(bp);
558  }
559  return NULL;
560}
561
562static void
563CcpRecvResetAck(struct fsm *fp, u_char id)
564{
565  /* Got a reset ACK, reset incoming dictionary */
566  struct ccp *ccp = fsm2ccp(fp);
567
568  if (ccp->reset_sent != -1) {
569    if (id != ccp->reset_sent) {
570      log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
571                " ignored\n", fp->link->name, id, ccp->reset_sent);
572      return;
573    }
574    /* Whaddaya know - a correct reset ack */
575  } else if (id == ccp->last_reset)
576    log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
577               fp->link->name);
578  else {
579    log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
580               fp->link->name, id);
581    return;
582  }
583
584  ccp->last_reset = ccp->reset_sent;
585  ccp->reset_sent = -1;
586  if (ccp->in.state != NULL)
587    (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
588}
589
590static struct mbuf *
591ccp_LayerPush(struct bundle *b, struct link *l, struct mbuf *bp,
592              int pri, u_short *proto)
593{
594  if (PROTO_COMPRESSIBLE(*proto) && l->ccp.fsm.state == ST_OPENED &&
595      l->ccp.out.state != NULL) {
596    bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
597           (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
598    switch (*proto) {
599      case PROTO_ICOMPD:
600        m_settype(bp, MB_ICOMPDOUT);
601        break;
602      case PROTO_COMPD:
603        m_settype(bp, MB_COMPDOUT);
604        break;
605    }
606  }
607
608  return bp;
609}
610
611static struct mbuf *
612ccp_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, u_short *proto)
613{
614  /*
615   * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
616   * decompression routines so that the dictionary's updated
617   */
618  if (l->ccp.fsm.state == ST_OPENED) {
619    if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
620      log_Printf(LogDEBUG, "ccp_LayerPull: PROTO_%sCOMPDP -> PROTO_IP\n",
621                 *proto == PROTO_ICOMPD ? "I" : "");
622      /* Decompress incoming data */
623      if (l->ccp.reset_sent != -1)
624        /* Send another REQ and put the packet in the bit bucket */
625        fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
626                   MB_CCPOUT);
627      else if (l->ccp.in.state != NULL) {
628        bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
629               (l->ccp.in.state, &l->ccp, proto, bp);
630        switch (*proto) {
631          case PROTO_ICOMPD:
632            m_settype(bp, MB_ICOMPDIN);
633            break;
634          case PROTO_COMPD:
635            m_settype(bp, MB_COMPDIN);
636            break;
637        }
638        return bp;
639      }
640      m_freem(bp);
641      bp = NULL;
642    } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
643      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet (dict only)\n");
644      /* Add incoming Network Layer traffic to our dictionary */
645      (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
646        (l->ccp.in.state, &l->ccp, *proto, bp);
647    } else
648      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet\n");
649  }
650
651  return bp;
652}
653
654u_short
655ccp_Proto(struct ccp *ccp)
656{
657  return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
658         PROTO_COMPD : PROTO_ICOMPD;
659}
660
661int
662ccp_SetOpenMode(struct ccp *ccp)
663{
664  int f;
665
666  for (f = 0; f < CCP_NEG_TOTAL; f++)
667    if (IsEnabled(ccp->cfg.neg[f])) {
668      ccp->fsm.open_mode = 0;
669      return 1;
670    }
671
672  ccp->fsm.open_mode = OPEN_PASSIVE;	/* Go straight to ST_STOPPED ? */
673
674  for (f = 0; f < CCP_NEG_TOTAL; f++)
675    if (IsAccepted(ccp->cfg.neg[f]))
676      return 1;
677
678  return 0;				/* No CCP at all */
679}
680
681struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };
682