hdlc.c revision 30715 
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 1.19 1997/09/10 21:36:54 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 "lcp.h"
39#include "lqr.h"
40#include "loadalias.h"
41#include "command.h"
42#include "vars.h"
43#include "pred.h"
44#include "modem.h"
45#include "ccp.h"
46
47struct hdlcstat {
48  int badfcs;
49  int badaddr;
50  int badcommand;
51  int unknownproto;
52}        HdlcStat;
53
54static int ifOutPackets;
55static int ifOutOctets;
56static int ifOutLQRs;
57static int ifInPackets;
58static int ifInOctets;
59
60struct protostat {
61  u_short number;
62  char *name;
63  u_long in_count;
64  u_long out_count;
65}         ProtocolStat[] = {
66
67  {
68    PROTO_IP, "IP"
69  },
70  {
71    PROTO_VJUNCOMP, "VJ_UNCOMP"
72  },
73  {
74    PROTO_VJCOMP, "VJ_COMP"
75  },
76  {
77    PROTO_COMPD, "COMPD"
78  },
79  {
80    PROTO_LCP, "LCP"
81  },
82  {
83    PROTO_IPCP, "IPCP"
84  },
85  {
86    PROTO_CCP, "CCP"
87  },
88  {
89    PROTO_PAP, "PAP"
90  },
91  {
92    PROTO_LQR, "LQR"
93  },
94  {
95    PROTO_CHAP, "CHAP"
96  },
97  {
98    0, "Others"
99  },
100};
101
102static u_short const fcstab[256] = {
103   /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
104   /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
105   /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
106   /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
107   /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
108   /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
109   /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
110   /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
111   /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
112   /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
113   /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
114   /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
115   /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
116   /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
117   /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
118   /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
119   /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
120   /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
121   /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
122   /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
123   /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
124   /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
125   /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
126   /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
127   /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
128   /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
129   /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
130   /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
131   /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
132   /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
133   /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
134   /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
135};
136
137u_char EscMap[33];
138
139void
140HdlcInit()
141{
142  ifInOctets = ifOutOctets = 0;
143  ifInPackets = ifOutPackets = 0;
144  ifOutLQRs = 0;
145}
146
147/*
148 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
149 *  2.27 for further details.
150 */
151inline u_short
152HdlcFcs(u_short fcs, u_char * cp, int len)
153{
154  while (len--)
155    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
156  return (fcs);
157}
158
159void
160HdlcOutput(int pri, u_short proto, struct mbuf * bp)
161{
162  struct mbuf *mhp, *mfcs;
163  struct protostat *statp;
164  struct lqrdata *lqr;
165  u_char *cp;
166  u_short fcs;
167
168  if ((proto & 0xfff1) == 0x21) {	/* Network Layer protocol */
169    if (CcpFsm.state == ST_OPENED) {
170      if (CcpInfo.want_proto == TY_PRED1) {
171        Pred1Output(pri, proto, bp);
172        return;
173      }
174    }
175  }
176  if (DEV_IS_SYNC)
177    mfcs = NULLBUFF;
178  else
179    mfcs = mballoc(2, MB_HDLCOUT);
180  mhp = mballoc(4, MB_HDLCOUT);
181  mhp->cnt = 0;
182  cp = MBUF_CTOP(mhp);
183  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
184    *cp++ = HDLC_ADDR;
185    *cp++ = HDLC_UI;
186    mhp->cnt += 2;
187  }
188
189  /*
190   * If possible, compress protocol field.
191   */
192  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
193    *cp++ = proto;
194    mhp->cnt++;
195  } else {
196    *cp++ = proto >> 8;
197    *cp = proto & 0377;
198    mhp->cnt += 2;
199  }
200  mhp->next = bp;
201  bp->next = mfcs;
202
203  lqr = &MyLqrData;
204  lqr->PeerOutPackets = ifOutPackets++;
205  ifOutOctets += plength(mhp) + 1;
206  lqr->PeerOutOctets = ifOutOctets;
207
208  if (proto == PROTO_LQR) {
209    lqr->MagicNumber = LcpInfo.want_magic;
210    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
211    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
212    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
213    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
214    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
215    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
216    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
217    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
218    lqr->PeerOutLQRs = ++ifOutLQRs;
219    LqrDump("LqrOutput", lqr);
220    LqrChangeOrder(lqr, (struct lqrdata *) (MBUF_CTOP(bp)));
221  }
222  if (!DEV_IS_SYNC) {
223    fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
224    fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
225    fcs = ~fcs;
226    cp = MBUF_CTOP(mfcs);
227    *cp++ = fcs & 0377;		/* Low byte first!! */
228    *cp++ = fcs >> 8;
229  }
230  LogDumpBp(LogHDLC, "HdlcOutput", mhp);
231  for (statp = ProtocolStat; statp->number; statp++)
232    if (statp->number == proto)
233      break;
234  statp->out_count++;
235  if (DEV_IS_SYNC)
236    ModemOutput(pri, mhp);
237  else
238    AsyncOutput(pri, mhp, proto);
239}
240
241void
242DecodePacket(u_short proto, struct mbuf * bp)
243{
244  u_char *cp;
245
246  LogPrintf(LogDEBUG, "DecodePacket: proto = %04x\n", proto);
247
248  switch (proto) {
249  case PROTO_LCP:
250    LcpInput(bp);
251    break;
252  case PROTO_PAP:
253    PapInput(bp);
254    break;
255  case PROTO_LQR:
256    HisLqrSave.SaveInLQRs++;
257    LqrInput(bp);
258    break;
259  case PROTO_CHAP:
260    ChapInput(bp);
261    break;
262  case PROTO_VJUNCOMP:
263  case PROTO_VJCOMP:
264    bp = VjCompInput(bp, proto);
265    if (bp == NULLBUFF) {
266      break;
267    }
268    /* fall down */
269  case PROTO_IP:
270    IpInput(bp);
271    break;
272  case PROTO_IPCP:
273    IpcpInput(bp);
274    break;
275  case PROTO_CCP:
276    CcpInput(bp);
277    break;
278  case PROTO_COMPD:
279    Pred1Input(bp);
280    break;
281  default:
282    LogPrintf(LogPHASE, "Unknown protocol 0x%04x\n", proto);
283    bp->offset -= 2;
284    bp->cnt += 2;
285    cp = MBUF_CTOP(bp);
286    LcpSendProtoRej(cp, bp->cnt);
287    HisLqrSave.SaveInDiscards++;
288    HdlcStat.unknownproto++;
289    pfree(bp);
290    break;
291  }
292}
293
294int
295ReportProtStatus()
296{
297  struct protostat *statp;
298  int cnt;
299
300  statp = ProtocolStat;
301  statp--;
302  cnt = 0;
303  fprintf(VarTerm, "    Protocol     in        out      Protocol      in       out\n");
304  do {
305    statp++;
306    fprintf(VarTerm, "   %-9s: %8lu, %8lu",
307	    statp->name, statp->in_count, statp->out_count);
308    if (++cnt == 2) {
309      fprintf(VarTerm, "\n");
310      cnt = 0;
311    }
312  } while (statp->number);
313  if (cnt)
314    fprintf(VarTerm, "\n");
315  return (1);
316}
317
318int
319ReportHdlcStatus()
320{
321  struct hdlcstat *hp = &HdlcStat;
322
323  if (VarTerm) {
324    fprintf(VarTerm, "HDLC level errors\n\n");
325    fprintf(VarTerm, "FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
326	    hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
327  }
328  return 0;
329}
330
331static struct hdlcstat laststat;
332
333void
334HdlcErrorCheck()
335{
336  struct hdlcstat *hp = &HdlcStat;
337  struct hdlcstat *op = &laststat;
338
339  if (memcmp(hp, op, sizeof(laststat))) {
340    LogPrintf(LogPHASE, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
341	      hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
342      hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
343  }
344  laststat = HdlcStat;
345}
346
347void
348HdlcInput(struct mbuf * bp)
349{
350  u_short fcs, proto;
351  u_char *cp, addr, ctrl;
352  struct protostat *statp;
353
354  LogDumpBp(LogHDLC, "HdlcInput:", bp);
355  if (DEV_IS_SYNC)
356    fcs = GOODFCS;
357  else
358    fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
359  HisLqrSave.SaveInOctets += bp->cnt + 1;
360
361  LogPrintf(LogDEBUG, "HdlcInput: fcs = %04x (%s)\n",
362	    fcs, (fcs == GOODFCS) ? "good" : "bad");
363  if (fcs != GOODFCS) {
364    HisLqrSave.SaveInErrors++;
365    LogPrintf(LogDEBUG, "HdlcInput: Bad FCS\n");
366    HdlcStat.badfcs++;
367    pfree(bp);
368    return;
369  }
370  if (!DEV_IS_SYNC)
371    bp->cnt -= 2;		/* discard FCS part */
372
373  if (bp->cnt < 2) {		/* XXX: raise this bar ? */
374    pfree(bp);
375    return;
376  }
377  cp = MBUF_CTOP(bp);
378
379  ifInPackets++;
380  ifInOctets += bp->cnt;
381
382  if (!LcpInfo.want_acfcomp) {
383
384    /*
385     * We expect that packet is not compressed.
386     */
387    addr = *cp++;
388    if (addr != HDLC_ADDR) {
389      HisLqrSave.SaveInErrors++;
390      HdlcStat.badaddr++;
391      LogPrintf(LogDEBUG, "HdlcInput: addr %02x\n", *cp);
392      pfree(bp);
393      return;
394    }
395    ctrl = *cp++;
396    if (ctrl != HDLC_UI) {
397      HisLqrSave.SaveInErrors++;
398      HdlcStat.badcommand++;
399      LogPrintf(LogDEBUG, "HdlcInput: %02x\n", *cp);
400      pfree(bp);
401      return;
402    }
403    bp->offset += 2;
404    bp->cnt -= 2;
405  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
406
407    /*
408     * We can receive compressed packet, but peer still send uncompressed
409     * packet to me.
410     */
411    cp += 2;
412    bp->offset += 2;
413    bp->cnt -= 2;
414  }
415  if (LcpInfo.want_protocomp) {
416    proto = 0;
417    cp--;
418    do {
419      cp++;
420      bp->offset++;
421      bp->cnt--;
422      proto = proto << 8;
423      proto += *cp;
424    } while (!(proto & 1));
425  } else {
426    proto = *cp++ << 8;
427    proto |= *cp++;
428    bp->offset += 2;
429    bp->cnt -= 2;
430  }
431
432  for (statp = ProtocolStat; statp->number; statp++)
433    if (statp->number == proto)
434      break;
435  statp->in_count++;
436  HisLqrSave.SaveInPackets++;
437
438  DecodePacket(proto, bp);
439}
440