ccp.c revision 94894 
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: head/usr.sbin/ppp/ccp.c 94894 2002-04-16 23:57:09Z brian $
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 <stdio.h>
39#include <stdlib.h>
40#include <string.h>	/* memcpy() on some archs */
41#include <termios.h>
42
43#include "layer.h"
44#include "defs.h"
45#include "command.h"
46#include "mbuf.h"
47#include "log.h"
48#include "timer.h"
49#include "fsm.h"
50#include "proto.h"
51#include "pred.h"
52#include "deflate.h"
53#include "throughput.h"
54#include "iplist.h"
55#include "slcompress.h"
56#include "lqr.h"
57#include "hdlc.h"
58#include "lcp.h"
59#include "ccp.h"
60#include "ncpaddr.h"
61#include "ip.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
80static void CcpSendConfigReq(struct fsm *);
81static void CcpSentTerminateReq(struct fsm *);
82static void CcpSendTerminateAck(struct fsm *, u_char);
83static void CcpDecodeConfig(struct fsm *, u_char *, u_char *, int,
84                            struct fsm_decode *);
85static void CcpLayerStart(struct fsm *);
86static void CcpLayerFinish(struct fsm *);
87static int CcpLayerUp(struct fsm *);
88static void CcpLayerDown(struct fsm *);
89static void CcpInitRestartCounter(struct fsm *, int);
90static int CcpRecvResetReq(struct fsm *);
91static void CcpRecvResetAck(struct fsm *, u_char);
92
93static 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
107static const char * const ccp_TimerNames[] =
108  {"CCP restart", "CCP openmode", "CCP stopped"};
109
110static const char *
111protoname(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 || proto > sizeof cftypes / sizeof *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 */
147static const struct ccp_algorithm * const algorithm[] = {
148  &DeflateAlgorithm,
149  &Pred1Algorithm,
150  &PppdDeflateAlgorithm
151#ifndef NODES
152  , &MPPEAlgorithm
153#endif
154};
155
156#define NALGORITHMS (sizeof algorithm/sizeof algorithm[0])
157
158int
159ccp_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
234void
235ccp_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
243void
244ccp_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
270void
271ccp_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 */
297int
298ccp_Required(struct ccp *ccp)
299{
300  int 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 */
314int
315ccp_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
323static void
324CcpInitRestartCounter(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
343static void
344CcpSendConfigReq(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  int f, alloc;
351
352  cp = buff;
353  o = &ccp->out.opt;
354  alloc = ccp->his_reject == 0 && ccp->out.opt == NULL;
355  ccp->my_proto = -1;
356  ccp->out.algorithm = -1;
357  for (f = 0; f < NALGORITHMS; f++)
358    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
359        !REJECTED(ccp, algorithm[f]->id) &&
360        (*algorithm[f]->Usable)(fp)) {
361
362      if (!alloc)
363        for (o = &ccp->out.opt; *o != NULL; o = &(*o)->next)
364          if ((*o)->val.hdr.id == algorithm[f]->id && (*o)->algorithm == f)
365            break;
366
367      if (alloc || *o == NULL) {
368        *o = (struct ccp_opt *)malloc(sizeof(struct ccp_opt));
369        (*o)->val.hdr.id = algorithm[f]->id;
370        (*o)->val.hdr.len = 2;
371        (*o)->next = NULL;
372        (*o)->algorithm = f;
373        (*algorithm[f]->o.OptInit)(&(*o)->val, &ccp->cfg);
374      }
375
376      if (cp + (*o)->val.hdr.len > buff + sizeof buff) {
377        log_Printf(LogERROR, "%s: CCP REQ buffer overrun !\n", fp->link->name);
378        break;
379      }
380      memcpy(cp, &(*o)->val, (*o)->val.hdr.len);
381      cp += (*o)->val.hdr.len;
382
383      ccp->my_proto = (*o)->val.hdr.id;
384      ccp->out.algorithm = f;
385
386      if (alloc)
387        o = &(*o)->next;
388    }
389
390  fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, cp - buff, MB_CCPOUT);
391}
392
393void
394ccp_SendResetReq(struct fsm *fp)
395{
396  /* We can't read our input - ask peer to reset */
397  struct ccp *ccp = fsm2ccp(fp);
398
399  ccp->reset_sent = fp->reqid;
400  ccp->last_reset = -1;
401  fsm_Output(fp, CODE_RESETREQ, fp->reqid, NULL, 0, MB_CCPOUT);
402}
403
404static void
405CcpSentTerminateReq(struct fsm *fp)
406{
407  /* Term REQ just sent by FSM */
408}
409
410static void
411CcpSendTerminateAck(struct fsm *fp, u_char id)
412{
413  /* Send Term ACK please */
414  fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_CCPOUT);
415}
416
417static int
418CcpRecvResetReq(struct fsm *fp)
419{
420  /* Got a reset REQ, reset outgoing dictionary */
421  struct ccp *ccp = fsm2ccp(fp);
422  if (ccp->out.state == NULL)
423    return 1;
424  return (*algorithm[ccp->out.algorithm]->o.Reset)(ccp->out.state);
425}
426
427static void
428CcpLayerStart(struct fsm *fp)
429{
430  /* We're about to start up ! */
431  struct ccp *ccp = fsm2ccp(fp);
432
433  log_Printf(LogCCP, "%s: LayerStart.\n", fp->link->name);
434  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
435}
436
437static void
438CcpLayerDown(struct fsm *fp)
439{
440  /* About to come down */
441  struct ccp *ccp = fsm2ccp(fp);
442  struct ccp_opt *next;
443
444  log_Printf(LogCCP, "%s: LayerDown.\n", fp->link->name);
445  if (ccp->in.state != NULL) {
446    (*algorithm[ccp->in.algorithm]->i.Term)(ccp->in.state);
447    ccp->in.state = NULL;
448    ccp->in.algorithm = -1;
449  }
450  if (ccp->out.state != NULL) {
451    (*algorithm[ccp->out.algorithm]->o.Term)(ccp->out.state);
452    ccp->out.state = NULL;
453    ccp->out.algorithm = -1;
454  }
455  ccp->his_reject = ccp->my_reject = 0;
456
457  while (ccp->out.opt) {
458    next = ccp->out.opt->next;
459    free(ccp->out.opt);
460    ccp->out.opt = next;
461  }
462  ccp_Setup(ccp);
463}
464
465static void
466CcpLayerFinish(struct fsm *fp)
467{
468  /* We're now down */
469  struct ccp *ccp = fsm2ccp(fp);
470  struct ccp_opt *next;
471
472  log_Printf(LogCCP, "%s: LayerFinish.\n", fp->link->name);
473
474  /*
475   * Nuke options that may be left over from sending a REQ but never
476   * coming up.
477   */
478  while (ccp->out.opt) {
479    next = ccp->out.opt->next;
480    free(ccp->out.opt);
481    ccp->out.opt = next;
482  }
483
484  if (ccp_Required(ccp)) {
485    if (fp->link->lcp.fsm.state == ST_OPENED)
486      log_Printf(LogLCP, "%s: Closing due to CCP completion\n", fp->link->name);
487    fsm_Close(&fp->link->lcp.fsm);
488  }
489}
490
491/*  Called when CCP has reached the OPEN state */
492static int
493CcpLayerUp(struct fsm *fp)
494{
495  /* We're now up */
496  struct ccp *ccp = fsm2ccp(fp);
497  struct ccp_opt **o;
498  int f, fail;
499
500  for (f = fail = 0; f < NALGORITHMS; f++)
501    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
502        (*algorithm[f]->Required)(&ccp->fsm) &&
503        (ccp->in.algorithm != f || ccp->out.algorithm != f)) {
504      /* Blow it all away - we haven't negotiated a required algorithm */
505      log_Printf(LogWARN, "%s: Failed to negotiate (required) %s\n",
506                 fp->link->name, protoname(algorithm[f]->id));
507      fail = 1;
508    }
509
510  if (fail) {
511    ccp->his_proto = ccp->my_proto = -1;
512    fsm_Close(fp);
513    fsm_Close(&fp->link->lcp.fsm);
514    return 0;
515  }
516
517  log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
518
519  if (ccp->in.state == NULL && ccp->in.algorithm >= 0 &&
520      ccp->in.algorithm < NALGORITHMS) {
521    ccp->in.state = (*algorithm[ccp->in.algorithm]->i.Init)(&ccp->in.opt);
522    if (ccp->in.state == NULL) {
523      log_Printf(LogERROR, "%s: %s (in) initialisation failure\n",
524                fp->link->name, protoname(ccp->his_proto));
525      ccp->his_proto = ccp->my_proto = -1;
526      fsm_Close(fp);
527      return 0;
528    }
529  }
530
531  o = &ccp->out.opt;
532  for (f = 0; f < ccp->out.algorithm; f++)
533    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
534      o = &(*o)->next;
535
536  if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
537      ccp->out.algorithm < NALGORITHMS) {
538    ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)(&(*o)->val);
539    if (ccp->out.state == NULL) {
540      log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
541                fp->link->name, protoname(ccp->my_proto));
542      ccp->his_proto = ccp->my_proto = -1;
543      fsm_Close(fp);
544      return 0;
545    }
546  }
547
548  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
549
550  log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
551            fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
552            protoname(ccp->his_proto), ccp->his_proto);
553
554  return 1;
555}
556
557static void
558CcpDecodeConfig(struct fsm *fp, u_char *cp, u_char *end, int mode_type,
559                struct fsm_decode *dec)
560{
561  /* Deal with incoming data */
562  struct ccp *ccp = fsm2ccp(fp);
563  int f;
564  const char *disp;
565  struct fsm_opt *opt;
566
567  if (mode_type == MODE_REQ)
568    ccp->in.algorithm = -1;	/* In case we've received two REQs in a row */
569
570  while (end - cp >= sizeof(opt->hdr)) {
571    if ((opt = fsm_readopt(&cp)) == NULL)
572      break;
573
574    for (f = NALGORITHMS-1; f > -1; f--)
575      if (algorithm[f]->id == opt->hdr.id)
576        break;
577
578    disp = f == -1 ? "" : (*algorithm[f]->Disp)(opt);
579    if (disp == NULL)
580      disp = "";
581
582    log_Printf(LogCCP, " %s[%d] %s\n", protoname(opt->hdr.id),
583               opt->hdr.len, disp);
584
585    if (f == -1) {
586      /* Don't understand that :-( */
587      if (mode_type == MODE_REQ) {
588        ccp->my_reject |= (1 << opt->hdr.id);
589        fsm_rej(dec, opt);
590      }
591    } else {
592      struct ccp_opt *o;
593
594      switch (mode_type) {
595      case MODE_REQ:
596        if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
597            (*algorithm[f]->Usable)(fp) &&
598            ccp->in.algorithm == -1) {
599          memcpy(&ccp->in.opt, opt, opt->hdr.len);
600          switch ((*algorithm[f]->i.Set)(&ccp->in.opt, &ccp->cfg)) {
601          case MODE_REJ:
602            fsm_rej(dec, &ccp->in.opt);
603            break;
604          case MODE_NAK:
605            fsm_nak(dec, &ccp->in.opt);
606            break;
607          case MODE_ACK:
608            fsm_ack(dec, &ccp->in.opt);
609            ccp->his_proto = opt->hdr.id;
610            ccp->in.algorithm = f;		/* This one'll do :-) */
611            break;
612          }
613        } else {
614          fsm_rej(dec, opt);
615        }
616        break;
617      case MODE_NAK:
618        for (o = ccp->out.opt; o != NULL; o = o->next)
619          if (o->val.hdr.id == opt->hdr.id)
620            break;
621        if (o == NULL)
622          log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent"
623                     " option\n", fp->link->name);
624        else {
625          memcpy(&o->val, opt, opt->hdr.len);
626          if ((*algorithm[f]->o.Set)(&o->val, &ccp->cfg) == MODE_ACK)
627            ccp->my_proto = algorithm[f]->id;
628          else {
629            ccp->his_reject |= (1 << opt->hdr.id);
630            ccp->my_proto = -1;
631            if (algorithm[f]->Required(fp)) {
632              log_Printf(LogWARN, "%s: Cannot understand peers (required)"
633                         " %s negotiation\n", fp->link->name,
634                         protoname(algorithm[f]->id));
635              fsm_Close(&fp->link->lcp.fsm);
636            }
637          }
638        }
639        break;
640      case MODE_REJ:
641        ccp->his_reject |= (1 << opt->hdr.id);
642        ccp->my_proto = -1;
643        if (algorithm[f]->Required(fp)) {
644          log_Printf(LogWARN, "%s: Peer rejected (required) %s negotiation\n",
645                     fp->link->name, protoname(algorithm[f]->id));
646          fsm_Close(&fp->link->lcp.fsm);
647        }
648        break;
649      }
650    }
651  }
652
653  if (mode_type != MODE_NOP) {
654    fsm_opt_normalise(dec);
655    if (dec->rejend != dec->rej || dec->nakend != dec->nak) {
656      if (ccp->in.state == NULL) {
657        ccp->his_proto = -1;
658        ccp->in.algorithm = -1;
659      }
660    }
661  }
662}
663
664extern struct mbuf *
665ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
666{
667  /* Got PROTO_CCP from link */
668  m_settype(bp, MB_CCPIN);
669  if (bundle_Phase(bundle) == PHASE_NETWORK)
670    fsm_Input(&l->ccp.fsm, bp);
671  else {
672    if (bundle_Phase(bundle) < PHASE_NETWORK)
673      log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
674                 l->ccp.fsm.link->name, bundle_PhaseName(bundle));
675    m_freem(bp);
676  }
677  return NULL;
678}
679
680static void
681CcpRecvResetAck(struct fsm *fp, u_char id)
682{
683  /* Got a reset ACK, reset incoming dictionary */
684  struct ccp *ccp = fsm2ccp(fp);
685
686  if (ccp->reset_sent != -1) {
687    if (id != ccp->reset_sent) {
688      log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
689                " ignored\n", fp->link->name, id, ccp->reset_sent);
690      return;
691    }
692    /* Whaddaya know - a correct reset ack */
693  } else if (id == ccp->last_reset)
694    log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
695               fp->link->name);
696  else {
697    log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
698               fp->link->name, id);
699    return;
700  }
701
702  ccp->last_reset = ccp->reset_sent;
703  ccp->reset_sent = -1;
704  if (ccp->in.state != NULL)
705    (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
706}
707
708static struct mbuf *
709ccp_LayerPush(struct bundle *b, struct link *l, struct mbuf *bp,
710              int pri, u_short *proto)
711{
712  if (PROTO_COMPRESSIBLE(*proto)) {
713    if (l->ccp.fsm.state != ST_OPENED) {
714      if (ccp_Required(&l->ccp)) {
715        /* The NCP layer shouldn't have let this happen ! */
716        log_Printf(LogERROR, "%s: Unexpected attempt to use an unopened and"
717                   " required CCP layer\n", l->name);
718        m_freem(bp);
719        bp = NULL;
720      }
721    } else if (l->ccp.out.state != NULL) {
722      bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
723             (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
724      switch (*proto) {
725        case PROTO_ICOMPD:
726          m_settype(bp, MB_ICOMPDOUT);
727          break;
728        case PROTO_COMPD:
729          m_settype(bp, MB_COMPDOUT);
730          break;
731      }
732    }
733  }
734
735  return bp;
736}
737
738static struct mbuf *
739ccp_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, u_short *proto)
740{
741  /*
742   * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
743   * decompression routines so that the dictionary's updated
744   */
745  if (l->ccp.fsm.state == ST_OPENED) {
746    if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
747      log_Printf(LogDEBUG, "ccp_LayerPull: PROTO_%sCOMPDP -> PROTO_IP\n",
748                 *proto == PROTO_ICOMPD ? "I" : "");
749      /* Decompress incoming data */
750      if (l->ccp.reset_sent != -1)
751        /* Send another REQ and put the packet in the bit bucket */
752        fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
753                   MB_CCPOUT);
754      else if (l->ccp.in.state != NULL) {
755        bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
756               (l->ccp.in.state, &l->ccp, proto, bp);
757        switch (*proto) {
758          case PROTO_ICOMPD:
759            m_settype(bp, MB_ICOMPDIN);
760            break;
761          case PROTO_COMPD:
762            m_settype(bp, MB_COMPDIN);
763            break;
764        }
765        return bp;
766      }
767      m_freem(bp);
768      bp = NULL;
769    } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
770      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet (dict only)\n");
771      /* Add incoming Network Layer traffic to our dictionary */
772      (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
773        (l->ccp.in.state, &l->ccp, *proto, bp);
774    } else
775      log_Printf(LogDEBUG, "ccp_LayerPull: Ignore packet\n");
776  }
777
778  return bp;
779}
780
781u_short
782ccp_Proto(struct ccp *ccp)
783{
784  return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
785         PROTO_COMPD : PROTO_ICOMPD;
786}
787
788int
789ccp_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
808int
809ccp_DefaultUsable(struct fsm *fp)
810{
811  return 1;
812}
813
814int
815ccp_DefaultRequired(struct fsm *fp)
816{
817  return 0;
818}
819
820struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };
821