hdlc.c revision 31514 
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 1.22 1997/11/22 03:37:32 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 "command.h"
32#include "mbuf.h"
33#include "log.h"
34#include "defs.h"
35#include "timer.h"
36#include "fsm.h"
37#include "hdlc.h"
38#include "lcpproto.h"
39#include "ipcp.h"
40#include "ip.h"
41#include "vjcomp.h"
42#include "pap.h"
43#include "chap.h"
44#include "lcp.h"
45#include "async.h"
46#include "lqr.h"
47#include "loadalias.h"
48#include "vars.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  const char *name;
68  u_long in_count;
69  u_long out_count;
70}         ProtocolStat[] = {
71
72  { PROTO_IP, "IP" },
73  { PROTO_VJUNCOMP, "VJ_UNCOMP" },
74  { PROTO_VJCOMP, "VJ_COMP" },
75  { PROTO_COMPD, "COMPD" },
76  { PROTO_LCP, "LCP" },
77  { PROTO_IPCP, "IPCP" },
78  { PROTO_CCP, "CCP" },
79  { PROTO_PAP, "PAP" },
80  { PROTO_LQR, "LQR" },
81  { PROTO_CHAP, "CHAP" },
82  { 0, "Others" }
83};
84
85static u_short const fcstab[256] = {
86   /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
87   /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
88   /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
89   /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
90   /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
91   /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
92   /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
93   /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
94   /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
95   /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
96   /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
97   /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
98   /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
99   /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
100   /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
101   /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
102   /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
103   /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
104   /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
105   /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
106   /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
107   /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
108   /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
109   /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
110   /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
111   /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
112   /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
113   /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
114   /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
115   /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
116   /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
117   /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
118};
119
120u_char EscMap[33];
121
122void
123HdlcInit()
124{
125  ifInOctets = ifOutOctets = 0;
126  ifInPackets = ifOutPackets = 0;
127  ifOutLQRs = 0;
128}
129
130/*
131 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
132 *  2.27 for further details.
133 */
134inline u_short
135HdlcFcs(u_short fcs, u_char * cp, int len)
136{
137  while (len--)
138    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
139  return (fcs);
140}
141
142inline u_short
143HdlcFcsBuf(u_short fcs, struct mbuf *m)
144{
145  int len;
146  u_char *pos, *end;
147
148  len = plength(m);
149  pos = MBUF_CTOP(m);
150  end = pos + m->cnt;
151  while (len--) {
152    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *pos++) & 0xff];
153    if (pos == end && len) {
154      m = m->next;
155      pos = MBUF_CTOP(m);
156      end = pos + m->cnt;
157    }
158  }
159  return (fcs);
160}
161
162void
163HdlcOutput(int pri, u_short proto, struct mbuf * bp)
164{
165  struct mbuf *mhp, *mfcs;
166  struct protostat *statp;
167  struct lqrdata *lqr;
168  u_char *cp;
169  u_short fcs;
170
171  if ((proto & 0xfff1) == 0x21)		/* Network Layer protocol */
172    if (CcpFsm.state == ST_OPENED)
173      if (CcpOutput(pri, proto, bp))
174        return;
175
176  if (DEV_IS_SYNC)
177    mfcs = NULLBUFF;
178  else
179    mfcs = mballoc(2, MB_HDLCOUT);
180
181  mhp = mballoc(4, MB_HDLCOUT);
182  mhp->cnt = 0;
183  cp = MBUF_CTOP(mhp);
184  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
185    *cp++ = HDLC_ADDR;
186    *cp++ = HDLC_UI;
187    mhp->cnt += 2;
188  }
189
190  /*
191   * If possible, compress protocol field.
192   */
193  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
194    *cp++ = proto;
195    mhp->cnt++;
196  } else {
197    *cp++ = proto >> 8;
198    *cp = proto & 0377;
199    mhp->cnt += 2;
200  }
201  mhp->next = bp;
202  while (bp->next != NULL)
203    bp = bp->next;
204  bp->next = mfcs;
205  bp = mhp->next;
206
207  lqr = &MyLqrData;
208  lqr->PeerOutPackets = ifOutPackets++;
209  ifOutOctets += plength(mhp) + 1;
210  lqr->PeerOutOctets = ifOutOctets;
211
212  if (proto == PROTO_LQR) {
213    lqr->MagicNumber = LcpInfo.want_magic;
214    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
215    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
216    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
217    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
218    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
219    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
220    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
221    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
222    lqr->PeerOutLQRs = ++ifOutLQRs;
223    LqrDump("LqrOutput", lqr);
224    LqrChangeOrder(lqr, (struct lqrdata *) (MBUF_CTOP(bp)));
225  }
226  if (!DEV_IS_SYNC) {
227    fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
228    fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
229    fcs = ~fcs;
230    cp = MBUF_CTOP(mfcs);
231    *cp++ = fcs & 0377;		/* Low byte first!! */
232    *cp++ = fcs >> 8;
233  }
234  LogDumpBp(LogHDLC, "HdlcOutput", mhp);
235  for (statp = ProtocolStat; statp->number; statp++)
236    if (statp->number == proto)
237      break;
238  statp->out_count++;
239
240  LogPrintf(LogDEBUG, "HdlcOutput: proto = 0x%04x\n", proto);
241
242  if (DEV_IS_SYNC)
243    ModemOutput(pri, mhp);
244  else
245    AsyncOutput(pri, mhp, proto);
246}
247
248void
249DecodePacket(u_short proto, struct mbuf * bp)
250{
251  u_char *cp;
252
253  LogPrintf(LogDEBUG, "DecodePacket: proto = 0x%04x\n", proto);
254
255  /*
256   * If proto isn't PROTO_COMPD, we still want to pass it to the
257   * decompression routines so that the dictionary's updated
258   */
259  if (proto == PROTO_COMPD) {
260    if ((bp = CompdInput(&proto, bp)) == NULL)
261      return;
262  } else if ((proto & 0xfff1) == 0x21)		/* Network Layer protocol */
263    if (CcpFsm.state == ST_OPENED)
264      CcpDictSetup(proto, bp);
265
266  switch (proto) {
267  case PROTO_LCP:
268    LcpInput(bp);
269    break;
270  case PROTO_PAP:
271    PapInput(bp);
272    break;
273  case PROTO_LQR:
274    HisLqrSave.SaveInLQRs++;
275    LqrInput(bp);
276    break;
277  case PROTO_CHAP:
278    ChapInput(bp);
279    break;
280  case PROTO_VJUNCOMP:
281  case PROTO_VJCOMP:
282    bp = VjCompInput(bp, proto);
283    if (bp == NULLBUFF) {
284      break;
285    }
286    /* fall down */
287  case PROTO_IP:
288    IpInput(bp);
289    break;
290  case PROTO_IPCP:
291    IpcpInput(bp);
292    break;
293  case PROTO_CCP:
294    CcpInput(bp);
295    break;
296  default:
297    LogPrintf(LogPHASE, "Unknown protocol 0x%04x\n", proto);
298    bp->offset -= 2;
299    bp->cnt += 2;
300    cp = MBUF_CTOP(bp);
301    LcpSendProtoRej(cp, bp->cnt);
302    HisLqrSave.SaveInDiscards++;
303    HdlcStat.unknownproto++;
304    pfree(bp);
305    break;
306  }
307}
308
309int
310ReportProtStatus(struct cmdargs const *arg)
311{
312  struct protostat *statp;
313  int cnt;
314
315  statp = ProtocolStat;
316  statp--;
317  cnt = 0;
318  fprintf(VarTerm, "    Protocol     in        out      Protocol      in       out\n");
319  do {
320    statp++;
321    fprintf(VarTerm, "   %-9s: %8lu, %8lu",
322	    statp->name, statp->in_count, statp->out_count);
323    if (++cnt == 2) {
324      fprintf(VarTerm, "\n");
325      cnt = 0;
326    }
327  } while (statp->number);
328  if (cnt)
329    fprintf(VarTerm, "\n");
330  return (1);
331}
332
333int
334ReportHdlcStatus(struct cmdargs const *arg)
335{
336  struct hdlcstat *hp = &HdlcStat;
337
338  if (VarTerm) {
339    fprintf(VarTerm, "HDLC level errors\n\n");
340    fprintf(VarTerm, "FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
341	    hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
342  }
343  return 0;
344}
345
346static struct hdlcstat laststat;
347
348void
349HdlcErrorCheck()
350{
351  struct hdlcstat *hp = &HdlcStat;
352  struct hdlcstat *op = &laststat;
353
354  if (memcmp(hp, op, sizeof(laststat))) {
355    LogPrintf(LogPHASE, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
356	      hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
357      hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
358  }
359  laststat = HdlcStat;
360}
361
362void
363HdlcInput(struct mbuf * bp)
364{
365  u_short fcs, proto;
366  u_char *cp, addr, ctrl;
367  struct protostat *statp;
368
369  LogDumpBp(LogHDLC, "HdlcInput:", bp);
370  if (DEV_IS_SYNC)
371    fcs = GOODFCS;
372  else
373    fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
374  HisLqrSave.SaveInOctets += bp->cnt + 1;
375
376  LogPrintf(LogDEBUG, "HdlcInput: fcs = %04x (%s)\n",
377	    fcs, (fcs == GOODFCS) ? "good" : "bad");
378  if (fcs != GOODFCS) {
379    HisLqrSave.SaveInErrors++;
380    LogPrintf(LogDEBUG, "HdlcInput: Bad FCS\n");
381    HdlcStat.badfcs++;
382    pfree(bp);
383    return;
384  }
385  if (!DEV_IS_SYNC)
386    bp->cnt -= 2;		/* discard FCS part */
387
388  if (bp->cnt < 2) {		/* XXX: raise this bar ? */
389    pfree(bp);
390    return;
391  }
392  cp = MBUF_CTOP(bp);
393
394  ifInPackets++;
395  ifInOctets += bp->cnt;
396
397  if (!LcpInfo.want_acfcomp) {
398
399    /*
400     * We expect that packet is not compressed.
401     */
402    addr = *cp++;
403    if (addr != HDLC_ADDR) {
404      HisLqrSave.SaveInErrors++;
405      HdlcStat.badaddr++;
406      LogPrintf(LogDEBUG, "HdlcInput: addr %02x\n", *cp);
407      pfree(bp);
408      return;
409    }
410    ctrl = *cp++;
411    if (ctrl != HDLC_UI) {
412      HisLqrSave.SaveInErrors++;
413      HdlcStat.badcommand++;
414      LogPrintf(LogDEBUG, "HdlcInput: %02x\n", *cp);
415      pfree(bp);
416      return;
417    }
418    bp->offset += 2;
419    bp->cnt -= 2;
420  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
421
422    /*
423     * We can receive compressed packet, but peer still send uncompressed
424     * packet to me.
425     */
426    cp += 2;
427    bp->offset += 2;
428    bp->cnt -= 2;
429  }
430  if (LcpInfo.want_protocomp) {
431    proto = 0;
432    cp--;
433    do {
434      cp++;
435      bp->offset++;
436      bp->cnt--;
437      proto = proto << 8;
438      proto += *cp;
439    } while (!(proto & 1));
440  } else {
441    proto = *cp++ << 8;
442    proto |= *cp++;
443    bp->offset += 2;
444    bp->cnt -= 2;
445  }
446
447  for (statp = ProtocolStat; statp->number; statp++)
448    if (statp->number == proto)
449      break;
450  statp->in_count++;
451  HisLqrSave.SaveInPackets++;
452
453  DecodePacket(proto, bp);
454}
455