hdlc.c revision 30733 
1/*
2 *	     PPP High Level Link Control (HDLC) Module
3 *
4 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
5 *
6 *   Copyright (C) 1993, 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: hdlc.c,v 1.20 1997/10/26 01:02:43 brian Exp $
21 *
22 *	TODO:
23 */
24#include <sys/param.h>
25#include <netinet/in.h>
26
27#include <stdio.h>
28#include <string.h>
29#include <termios.h>
30
31#include "mbuf.h"
32#include "log.h"
33#include "defs.h"
34#include "timer.h"
35#include "fsm.h"
36#include "hdlc.h"
37#include "lcpproto.h"
38#include "ipcp.h"
39#include "ip.h"
40#include "vjcomp.h"
41#include "pap.h"
42#include "chap.h"
43#include "lcp.h"
44#include "lqr.h"
45#include "loadalias.h"
46#include "command.h"
47#include "vars.h"
48#include "pred.h"
49#include "modem.h"
50#include "ccp.h"
51
52struct hdlcstat {
53  int badfcs;
54  int badaddr;
55  int badcommand;
56  int unknownproto;
57}        HdlcStat;
58
59static int ifOutPackets;
60static int ifOutOctets;
61static int ifOutLQRs;
62static int ifInPackets;
63static int ifInOctets;
64
65struct protostat {
66  u_short number;
67  char *name;
68  u_long in_count;
69  u_long out_count;
70}         ProtocolStat[] = {
71
72  {
73    PROTO_IP, "IP"
74  },
75  {
76    PROTO_VJUNCOMP, "VJ_UNCOMP"
77  },
78  {
79    PROTO_VJCOMP, "VJ_COMP"
80  },
81  {
82    PROTO_COMPD, "COMPD"
83  },
84  {
85    PROTO_LCP, "LCP"
86  },
87  {
88    PROTO_IPCP, "IPCP"
89  },
90  {
91    PROTO_CCP, "CCP"
92  },
93  {
94    PROTO_PAP, "PAP"
95  },
96  {
97    PROTO_LQR, "LQR"
98  },
99  {
100    PROTO_CHAP, "CHAP"
101  },
102  {
103    0, "Others"
104  },
105};
106
107static u_short const fcstab[256] = {
108   /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
109   /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
110   /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
111   /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
112   /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
113   /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
114   /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
115   /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
116   /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
117   /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
118   /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
119   /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
120   /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
121   /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
122   /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
123   /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
124   /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
125   /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
126   /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
127   /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
128   /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
129   /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
130   /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
131   /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
132   /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
133   /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
134   /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
135   /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
136   /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
137   /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
138   /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
139   /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
140};
141
142u_char EscMap[33];
143
144void
145HdlcInit()
146{
147  ifInOctets = ifOutOctets = 0;
148  ifInPackets = ifOutPackets = 0;
149  ifOutLQRs = 0;
150}
151
152/*
153 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
154 *  2.27 for further details.
155 */
156inline u_short
157HdlcFcs(u_short fcs, u_char * cp, int len)
158{
159  while (len--)
160    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
161  return (fcs);
162}
163
164void
165HdlcOutput(int pri, u_short proto, struct mbuf * bp)
166{
167  struct mbuf *mhp, *mfcs;
168  struct protostat *statp;
169  struct lqrdata *lqr;
170  u_char *cp;
171  u_short fcs;
172
173  if ((proto & 0xfff1) == 0x21) {	/* Network Layer protocol */
174    if (CcpFsm.state == ST_OPENED) {
175      if (CcpInfo.want_proto == TY_PRED1) {
176        Pred1Output(pri, proto, bp);
177        return;
178      }
179    }
180  }
181  if (DEV_IS_SYNC)
182    mfcs = NULLBUFF;
183  else
184    mfcs = mballoc(2, MB_HDLCOUT);
185  mhp = mballoc(4, MB_HDLCOUT);
186  mhp->cnt = 0;
187  cp = MBUF_CTOP(mhp);
188  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
189    *cp++ = HDLC_ADDR;
190    *cp++ = HDLC_UI;
191    mhp->cnt += 2;
192  }
193
194  /*
195   * If possible, compress protocol field.
196   */
197  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
198    *cp++ = proto;
199    mhp->cnt++;
200  } else {
201    *cp++ = proto >> 8;
202    *cp = proto & 0377;
203    mhp->cnt += 2;
204  }
205  mhp->next = bp;
206  bp->next = mfcs;
207
208  lqr = &MyLqrData;
209  lqr->PeerOutPackets = ifOutPackets++;
210  ifOutOctets += plength(mhp) + 1;
211  lqr->PeerOutOctets = ifOutOctets;
212
213  if (proto == PROTO_LQR) {
214    lqr->MagicNumber = LcpInfo.want_magic;
215    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
216    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
217    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
218    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
219    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
220    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
221    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
222    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
223    lqr->PeerOutLQRs = ++ifOutLQRs;
224    LqrDump("LqrOutput", lqr);
225    LqrChangeOrder(lqr, (struct lqrdata *) (MBUF_CTOP(bp)));
226  }
227  if (!DEV_IS_SYNC) {
228    fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
229    fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
230    fcs = ~fcs;
231    cp = MBUF_CTOP(mfcs);
232    *cp++ = fcs & 0377;		/* Low byte first!! */
233    *cp++ = fcs >> 8;
234  }
235  LogDumpBp(LogHDLC, "HdlcOutput", mhp);
236  for (statp = ProtocolStat; statp->number; statp++)
237    if (statp->number == proto)
238      break;
239  statp->out_count++;
240  if (DEV_IS_SYNC)
241    ModemOutput(pri, mhp);
242  else
243    AsyncOutput(pri, mhp, proto);
244}
245
246void
247DecodePacket(u_short proto, struct mbuf * bp)
248{
249  u_char *cp;
250
251  LogPrintf(LogDEBUG, "DecodePacket: proto = %04x\n", proto);
252
253  switch (proto) {
254  case PROTO_LCP:
255    LcpInput(bp);
256    break;
257  case PROTO_PAP:
258    PapInput(bp);
259    break;
260  case PROTO_LQR:
261    HisLqrSave.SaveInLQRs++;
262    LqrInput(bp);
263    break;
264  case PROTO_CHAP:
265    ChapInput(bp);
266    break;
267  case PROTO_VJUNCOMP:
268  case PROTO_VJCOMP:
269    bp = VjCompInput(bp, proto);
270    if (bp == NULLBUFF) {
271      break;
272    }
273    /* fall down */
274  case PROTO_IP:
275    IpInput(bp);
276    break;
277  case PROTO_IPCP:
278    IpcpInput(bp);
279    break;
280  case PROTO_CCP:
281    CcpInput(bp);
282    break;
283  case PROTO_COMPD:
284    Pred1Input(bp);
285    break;
286  default:
287    LogPrintf(LogPHASE, "Unknown protocol 0x%04x\n", proto);
288    bp->offset -= 2;
289    bp->cnt += 2;
290    cp = MBUF_CTOP(bp);
291    LcpSendProtoRej(cp, bp->cnt);
292    HisLqrSave.SaveInDiscards++;
293    HdlcStat.unknownproto++;
294    pfree(bp);
295    break;
296  }
297}
298
299int
300ReportProtStatus()
301{
302  struct protostat *statp;
303  int cnt;
304
305  statp = ProtocolStat;
306  statp--;
307  cnt = 0;
308  fprintf(VarTerm, "    Protocol     in        out      Protocol      in       out\n");
309  do {
310    statp++;
311    fprintf(VarTerm, "   %-9s: %8lu, %8lu",
312	    statp->name, statp->in_count, statp->out_count);
313    if (++cnt == 2) {
314      fprintf(VarTerm, "\n");
315      cnt = 0;
316    }
317  } while (statp->number);
318  if (cnt)
319    fprintf(VarTerm, "\n");
320  return (1);
321}
322
323int
324ReportHdlcStatus()
325{
326  struct hdlcstat *hp = &HdlcStat;
327
328  if (VarTerm) {
329    fprintf(VarTerm, "HDLC level errors\n\n");
330    fprintf(VarTerm, "FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
331	    hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
332  }
333  return 0;
334}
335
336static struct hdlcstat laststat;
337
338void
339HdlcErrorCheck()
340{
341  struct hdlcstat *hp = &HdlcStat;
342  struct hdlcstat *op = &laststat;
343
344  if (memcmp(hp, op, sizeof(laststat))) {
345    LogPrintf(LogPHASE, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
346	      hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
347      hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
348  }
349  laststat = HdlcStat;
350}
351
352void
353HdlcInput(struct mbuf * bp)
354{
355  u_short fcs, proto;
356  u_char *cp, addr, ctrl;
357  struct protostat *statp;
358
359  LogDumpBp(LogHDLC, "HdlcInput:", bp);
360  if (DEV_IS_SYNC)
361    fcs = GOODFCS;
362  else
363    fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
364  HisLqrSave.SaveInOctets += bp->cnt + 1;
365
366  LogPrintf(LogDEBUG, "HdlcInput: fcs = %04x (%s)\n",
367	    fcs, (fcs == GOODFCS) ? "good" : "bad");
368  if (fcs != GOODFCS) {
369    HisLqrSave.SaveInErrors++;
370    LogPrintf(LogDEBUG, "HdlcInput: Bad FCS\n");
371    HdlcStat.badfcs++;
372    pfree(bp);
373    return;
374  }
375  if (!DEV_IS_SYNC)
376    bp->cnt -= 2;		/* discard FCS part */
377
378  if (bp->cnt < 2) {		/* XXX: raise this bar ? */
379    pfree(bp);
380    return;
381  }
382  cp = MBUF_CTOP(bp);
383
384  ifInPackets++;
385  ifInOctets += bp->cnt;
386
387  if (!LcpInfo.want_acfcomp) {
388
389    /*
390     * We expect that packet is not compressed.
391     */
392    addr = *cp++;
393    if (addr != HDLC_ADDR) {
394      HisLqrSave.SaveInErrors++;
395      HdlcStat.badaddr++;
396      LogPrintf(LogDEBUG, "HdlcInput: addr %02x\n", *cp);
397      pfree(bp);
398      return;
399    }
400    ctrl = *cp++;
401    if (ctrl != HDLC_UI) {
402      HisLqrSave.SaveInErrors++;
403      HdlcStat.badcommand++;
404      LogPrintf(LogDEBUG, "HdlcInput: %02x\n", *cp);
405      pfree(bp);
406      return;
407    }
408    bp->offset += 2;
409    bp->cnt -= 2;
410  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
411
412    /*
413     * We can receive compressed packet, but peer still send uncompressed
414     * packet to me.
415     */
416    cp += 2;
417    bp->offset += 2;
418    bp->cnt -= 2;
419  }
420  if (LcpInfo.want_protocomp) {
421    proto = 0;
422    cp--;
423    do {
424      cp++;
425      bp->offset++;
426      bp->cnt--;
427      proto = proto << 8;
428      proto += *cp;
429    } while (!(proto & 1));
430  } else {
431    proto = *cp++ << 8;
432    proto |= *cp++;
433    bp->offset += 2;
434    bp->cnt -= 2;
435  }
436
437  for (statp = ProtocolStat; statp->number; statp++)
438    if (statp->number == proto)
439      break;
440  statp->in_count++;
441  HisLqrSave.SaveInPackets++;
442
443  DecodePacket(proto, bp);
444}
445