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: releng/11.0/usr.sbin/ppp/ccp.c 136375 2004-10-11 09:45:58Z 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 <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
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 || (unsigned)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  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 */
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  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        if ((*o = (struct ccp_opt *)malloc(sizeof(struct ccp_opt))) == NULL) {
370	  log_Printf(LogERROR, "%s: Not enough memory for CCP REQ !\n",
371		     fp->link->name);
372	  break;
373	}
374        (*o)->val.hdr.id = algorithm[f]->id;
375        (*o)->val.hdr.len = 2;
376        (*o)->next = NULL;
377        (*o)->algorithm = f;
378        (*algorithm[f]->o.OptInit)(fp->bundle, &(*o)->val, &ccp->cfg);
379      }
380
381      if (cp + (*o)->val.hdr.len > buff + sizeof buff) {
382        log_Printf(LogERROR, "%s: CCP REQ buffer overrun !\n", fp->link->name);
383        break;
384      }
385      memcpy(cp, &(*o)->val, (*o)->val.hdr.len);
386      cp += (*o)->val.hdr.len;
387
388      ccp->my_proto = (*o)->val.hdr.id;
389      ccp->out.algorithm = f;
390
391      if (alloc)
392        o = &(*o)->next;
393    }
394
395  fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, cp - buff, MB_CCPOUT);
396}
397
398void
399ccp_SendResetReq(struct fsm *fp)
400{
401  /* We can't read our input - ask peer to reset */
402  struct ccp *ccp = fsm2ccp(fp);
403
404  ccp->reset_sent = fp->reqid;
405  ccp->last_reset = -1;
406  fsm_Output(fp, CODE_RESETREQ, fp->reqid, NULL, 0, MB_CCPOUT);
407}
408
409static void
410CcpSentTerminateReq(struct fsm *fp __unused)
411{
412  /* Term REQ just sent by FSM */
413}
414
415static void
416CcpSendTerminateAck(struct fsm *fp, u_char id)
417{
418  /* Send Term ACK please */
419  fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_CCPOUT);
420}
421
422static int
423CcpRecvResetReq(struct fsm *fp)
424{
425  /* Got a reset REQ, reset outgoing dictionary */
426  struct ccp *ccp = fsm2ccp(fp);
427  if (ccp->out.state == NULL)
428    return 1;
429  return (*algorithm[ccp->out.algorithm]->o.Reset)(ccp->out.state);
430}
431
432static void
433CcpLayerStart(struct fsm *fp)
434{
435  /* We're about to start up ! */
436  struct ccp *ccp = fsm2ccp(fp);
437
438  log_Printf(LogCCP, "%s: LayerStart.\n", fp->link->name);
439  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
440}
441
442static void
443CcpLayerDown(struct fsm *fp)
444{
445  /* About to come down */
446  struct ccp *ccp = fsm2ccp(fp);
447  struct ccp_opt *next;
448
449  log_Printf(LogCCP, "%s: LayerDown.\n", fp->link->name);
450  if (ccp->in.state != NULL) {
451    (*algorithm[ccp->in.algorithm]->i.Term)(ccp->in.state);
452    ccp->in.state = NULL;
453    ccp->in.algorithm = -1;
454  }
455  if (ccp->out.state != NULL) {
456    (*algorithm[ccp->out.algorithm]->o.Term)(ccp->out.state);
457    ccp->out.state = NULL;
458    ccp->out.algorithm = -1;
459  }
460  ccp->his_reject = ccp->my_reject = 0;
461
462  while (ccp->out.opt) {
463    next = ccp->out.opt->next;
464    free(ccp->out.opt);
465    ccp->out.opt = next;
466  }
467  ccp_Setup(ccp);
468}
469
470static void
471CcpLayerFinish(struct fsm *fp)
472{
473  /* We're now down */
474  struct ccp *ccp = fsm2ccp(fp);
475  struct ccp_opt *next;
476
477  log_Printf(LogCCP, "%s: LayerFinish.\n", fp->link->name);
478
479  /*
480   * Nuke options that may be left over from sending a REQ but never
481   * coming up.
482   */
483  while (ccp->out.opt) {
484    next = ccp->out.opt->next;
485    free(ccp->out.opt);
486    ccp->out.opt = next;
487  }
488
489  if (ccp_Required(ccp)) {
490    if (fp->link->lcp.fsm.state == ST_OPENED)
491      log_Printf(LogLCP, "%s: Closing due to CCP completion\n", fp->link->name);
492    fsm_Close(&fp->link->lcp.fsm);
493  }
494}
495
496/*  Called when CCP has reached the OPEN state */
497static int
498CcpLayerUp(struct fsm *fp)
499{
500  /* We're now up */
501  struct ccp *ccp = fsm2ccp(fp);
502  struct ccp_opt **o;
503  unsigned f, fail;
504
505  for (f = fail = 0; f < NALGORITHMS; f++)
506    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
507        (*algorithm[f]->Required)(&ccp->fsm) &&
508        (ccp->in.algorithm != (int)f || ccp->out.algorithm != (int)f)) {
509      /* Blow it all away - we haven't negotiated a required algorithm */
510      log_Printf(LogWARN, "%s: Failed to negotiate (required) %s\n",
511                 fp->link->name, protoname(algorithm[f]->id));
512      fail = 1;
513    }
514
515  if (fail) {
516    ccp->his_proto = ccp->my_proto = -1;
517    fsm_Close(fp);
518    fsm_Close(&fp->link->lcp.fsm);
519    return 0;
520  }
521
522  log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
523
524  if (ccp->in.state == NULL && ccp->in.algorithm >= 0 &&
525      ccp->in.algorithm < (int)NALGORITHMS) {
526    ccp->in.state = (*algorithm[ccp->in.algorithm]->i.Init)
527      (fp->bundle, &ccp->in.opt);
528    if (ccp->in.state == NULL) {
529      log_Printf(LogERROR, "%s: %s (in) initialisation failure\n",
530                fp->link->name, protoname(ccp->his_proto));
531      ccp->his_proto = ccp->my_proto = -1;
532      fsm_Close(fp);
533      return 0;
534    }
535  }
536
537  o = &ccp->out.opt;
538  if (ccp->out.algorithm > 0)
539    for (f = 0; f < (unsigned)ccp->out.algorithm; f++)
540      if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]))
541	o = &(*o)->next;
542
543  if (ccp->out.state == NULL && ccp->out.algorithm >= 0 &&
544      ccp->out.algorithm < (int)NALGORITHMS) {
545    ccp->out.state = (*algorithm[ccp->out.algorithm]->o.Init)
546      (fp->bundle, &(*o)->val);
547    if (ccp->out.state == NULL) {
548      log_Printf(LogERROR, "%s: %s (out) initialisation failure\n",
549                fp->link->name, protoname(ccp->my_proto));
550      ccp->his_proto = ccp->my_proto = -1;
551      fsm_Close(fp);
552      return 0;
553    }
554  }
555
556  fp->more.reqs = fp->more.naks = fp->more.rejs = ccp->cfg.fsm.maxreq * 3;
557
558  log_Printf(LogCCP, "%s: Out = %s[%d], In = %s[%d]\n",
559            fp->link->name, protoname(ccp->my_proto), ccp->my_proto,
560            protoname(ccp->his_proto), ccp->his_proto);
561
562  return 1;
563}
564
565static void
566CcpDecodeConfig(struct fsm *fp, u_char *cp, u_char *end, int mode_type,
567                struct fsm_decode *dec)
568{
569  /* Deal with incoming data */
570  struct ccp *ccp = fsm2ccp(fp);
571  int f;
572  const char *disp;
573  struct fsm_opt *opt;
574
575  if (mode_type == MODE_REQ)
576    ccp->in.algorithm = -1;	/* In case we've received two REQs in a row */
577
578  while (end >= cp + sizeof(opt->hdr)) {
579    if ((opt = fsm_readopt(&cp)) == NULL)
580      break;
581
582    for (f = NALGORITHMS-1; f > -1; f--)
583      if (algorithm[f]->id == opt->hdr.id)
584        break;
585
586    disp = f == -1 ? "" : (*algorithm[f]->Disp)(opt);
587    if (disp == NULL)
588      disp = "";
589
590    log_Printf(LogCCP, " %s[%d] %s\n", protoname(opt->hdr.id),
591               opt->hdr.len, disp);
592
593    if (f == -1) {
594      /* Don't understand that :-( */
595      if (mode_type == MODE_REQ) {
596        ccp->my_reject |= (1 << opt->hdr.id);
597        fsm_rej(dec, opt);
598      }
599    } else {
600      struct ccp_opt *o;
601
602      switch (mode_type) {
603      case MODE_REQ:
604        if (IsAccepted(ccp->cfg.neg[algorithm[f]->Neg]) &&
605            (*algorithm[f]->Usable)(fp) &&
606            ccp->in.algorithm == -1) {
607          memcpy(&ccp->in.opt, opt, opt->hdr.len);
608          switch ((*algorithm[f]->i.Set)(fp->bundle, &ccp->in.opt, &ccp->cfg)) {
609          case MODE_REJ:
610            fsm_rej(dec, &ccp->in.opt);
611            break;
612          case MODE_NAK:
613            fsm_nak(dec, &ccp->in.opt);
614            break;
615          case MODE_ACK:
616            fsm_ack(dec, &ccp->in.opt);
617            ccp->his_proto = opt->hdr.id;
618            ccp->in.algorithm = (int)f;		/* This one'll do :-) */
619            break;
620          }
621        } else {
622          fsm_rej(dec, opt);
623        }
624        break;
625      case MODE_NAK:
626        for (o = ccp->out.opt; o != NULL; o = o->next)
627          if (o->val.hdr.id == opt->hdr.id)
628            break;
629        if (o == NULL)
630          log_Printf(LogCCP, "%s: Warning: Ignoring peer NAK of unsent"
631                     " option\n", fp->link->name);
632        else {
633          memcpy(&o->val, opt, opt->hdr.len);
634          if ((*algorithm[f]->o.Set)(fp->bundle, &o->val, &ccp->cfg) ==
635              MODE_ACK)
636            ccp->my_proto = algorithm[f]->id;
637          else {
638            ccp->his_reject |= (1 << opt->hdr.id);
639            ccp->my_proto = -1;
640            if (algorithm[f]->Required(fp)) {
641              log_Printf(LogWARN, "%s: Cannot understand peers (required)"
642                         " %s negotiation\n", fp->link->name,
643                         protoname(algorithm[f]->id));
644              fsm_Close(&fp->link->lcp.fsm);
645            }
646          }
647        }
648        break;
649      case MODE_REJ:
650        ccp->his_reject |= (1 << opt->hdr.id);
651        ccp->my_proto = -1;
652        if (algorithm[f]->Required(fp)) {
653          log_Printf(LogWARN, "%s: Peer rejected (required) %s negotiation\n",
654                     fp->link->name, protoname(algorithm[f]->id));
655          fsm_Close(&fp->link->lcp.fsm);
656        }
657        break;
658      }
659    }
660  }
661
662  if (mode_type != MODE_NOP) {
663    fsm_opt_normalise(dec);
664    if (dec->rejend != dec->rej || dec->nakend != dec->nak) {
665      if (ccp->in.state == NULL) {
666        ccp->his_proto = -1;
667        ccp->in.algorithm = -1;
668      }
669    }
670  }
671}
672
673extern struct mbuf *
674ccp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
675{
676  /* Got PROTO_CCP from link */
677  m_settype(bp, MB_CCPIN);
678  if (bundle_Phase(bundle) == PHASE_NETWORK)
679    fsm_Input(&l->ccp.fsm, bp);
680  else {
681    if (bundle_Phase(bundle) < PHASE_NETWORK)
682      log_Printf(LogCCP, "%s: Error: Unexpected CCP in phase %s (ignored)\n",
683                 l->ccp.fsm.link->name, bundle_PhaseName(bundle));
684    m_freem(bp);
685  }
686  return NULL;
687}
688
689static void
690CcpRecvResetAck(struct fsm *fp, u_char id)
691{
692  /* Got a reset ACK, reset incoming dictionary */
693  struct ccp *ccp = fsm2ccp(fp);
694
695  if (ccp->reset_sent != -1) {
696    if (id != ccp->reset_sent) {
697      log_Printf(LogCCP, "%s: Incorrect ResetAck (id %d, not %d)"
698                " ignored\n", fp->link->name, id, ccp->reset_sent);
699      return;
700    }
701    /* Whaddaya know - a correct reset ack */
702  } else if (id == ccp->last_reset)
703    log_Printf(LogCCP, "%s: Duplicate ResetAck (resetting again)\n",
704               fp->link->name);
705  else {
706    log_Printf(LogCCP, "%s: Unexpected ResetAck (id %d) ignored\n",
707               fp->link->name, id);
708    return;
709  }
710
711  ccp->last_reset = ccp->reset_sent;
712  ccp->reset_sent = -1;
713  if (ccp->in.state != NULL)
714    (*algorithm[ccp->in.algorithm]->i.Reset)(ccp->in.state);
715}
716
717static struct mbuf *
718ccp_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
719              int pri, u_short *proto)
720{
721  if (PROTO_COMPRESSIBLE(*proto)) {
722    if (l->ccp.fsm.state != ST_OPENED) {
723      if (ccp_Required(&l->ccp)) {
724        /* The NCP layer shouldn't have let this happen ! */
725        log_Printf(LogERROR, "%s: Unexpected attempt to use an unopened and"
726                   " required CCP layer\n", l->name);
727        m_freem(bp);
728        bp = NULL;
729      }
730    } else if (l->ccp.out.state != NULL) {
731      bp = (*algorithm[l->ccp.out.algorithm]->o.Write)
732             (l->ccp.out.state, &l->ccp, l, pri, proto, bp);
733      switch (*proto) {
734        case PROTO_ICOMPD:
735          m_settype(bp, MB_ICOMPDOUT);
736          break;
737        case PROTO_COMPD:
738          m_settype(bp, MB_COMPDOUT);
739          break;
740      }
741    }
742  }
743
744  return bp;
745}
746
747static struct mbuf *
748ccp_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp,
749	      u_short *proto)
750{
751  /*
752   * If proto isn't PROTO_[I]COMPD, we still want to pass it to the
753   * decompression routines so that the dictionary's updated
754   */
755  if (l->ccp.fsm.state == ST_OPENED) {
756    if (*proto == PROTO_COMPD || *proto == PROTO_ICOMPD) {
757      /* Decompress incoming data */
758      if (l->ccp.reset_sent != -1)
759        /* Send another REQ and put the packet in the bit bucket */
760        fsm_Output(&l->ccp.fsm, CODE_RESETREQ, l->ccp.reset_sent, NULL, 0,
761                   MB_CCPOUT);
762      else if (l->ccp.in.state != NULL) {
763        bp = (*algorithm[l->ccp.in.algorithm]->i.Read)
764               (l->ccp.in.state, &l->ccp, proto, bp);
765        switch (*proto) {
766          case PROTO_ICOMPD:
767            m_settype(bp, MB_ICOMPDIN);
768            break;
769          case PROTO_COMPD:
770            m_settype(bp, MB_COMPDIN);
771            break;
772        }
773        return bp;
774      }
775      m_freem(bp);
776      bp = NULL;
777    } else if (PROTO_COMPRESSIBLE(*proto) && l->ccp.in.state != NULL) {
778      /* Add incoming Network Layer traffic to our dictionary */
779      (*algorithm[l->ccp.in.algorithm]->i.DictSetup)
780        (l->ccp.in.state, &l->ccp, *proto, bp);
781    }
782  }
783
784  return bp;
785}
786
787u_short
788ccp_Proto(struct ccp *ccp)
789{
790  return !link2physical(ccp->fsm.link) || !ccp->fsm.bundle->ncp.mp.active ?
791         PROTO_COMPD : PROTO_ICOMPD;
792}
793
794int
795ccp_SetOpenMode(struct ccp *ccp)
796{
797  int f;
798
799  for (f = 0; f < CCP_NEG_TOTAL; f++)
800    if (IsEnabled(ccp->cfg.neg[f])) {
801      ccp->fsm.open_mode = 0;
802      return 1;
803    }
804
805  ccp->fsm.open_mode = OPEN_PASSIVE;	/* Go straight to ST_STOPPED ? */
806
807  for (f = 0; f < CCP_NEG_TOTAL; f++)
808    if (IsAccepted(ccp->cfg.neg[f]))
809      return 1;
810
811  return 0;				/* No CCP at all */
812}
813
814int
815ccp_DefaultUsable(struct fsm *fp __unused)
816{
817  return 1;
818}
819
820int
821ccp_DefaultRequired(struct fsm *fp __unused)
822{
823  return 0;
824}
825
826struct layer ccplayer = { LAYER_CCP, "ccp", ccp_LayerPush, ccp_LayerPull };
827