hdlc.c revision 31343
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 1.21 1997/10/26 12:42:10 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 "pred.h"
50#include "modem.h"
51#include "ccp.h"
52
53struct hdlcstat {
54  int badfcs;
55  int badaddr;
56  int badcommand;
57  int unknownproto;
58}        HdlcStat;
59
60static int ifOutPackets;
61static int ifOutOctets;
62static int ifOutLQRs;
63static int ifInPackets;
64static int ifInOctets;
65
66struct protostat {
67  u_short number;
68  const char *name;
69  u_long in_count;
70  u_long out_count;
71}         ProtocolStat[] = {
72
73  { PROTO_IP, "IP" },
74  { PROTO_VJUNCOMP, "VJ_UNCOMP" },
75  { PROTO_VJCOMP, "VJ_COMP" },
76  { PROTO_COMPD, "COMPD" },
77  { PROTO_LCP, "LCP" },
78  { PROTO_IPCP, "IPCP" },
79  { PROTO_CCP, "CCP" },
80  { PROTO_PAP, "PAP" },
81  { PROTO_LQR, "LQR" },
82  { PROTO_CHAP, "CHAP" },
83  { 0, "Others" }
84};
85
86static u_short const fcstab[256] = {
87   /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
88   /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
89   /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
90   /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
91   /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
92   /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
93   /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
94   /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
95   /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
96   /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
97   /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
98   /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
99   /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
100   /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
101   /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
102   /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
103   /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
104   /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
105   /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
106   /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
107   /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
108   /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
109   /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
110   /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
111   /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
112   /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
113   /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
114   /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
115   /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
116   /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
117   /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
118   /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
119};
120
121u_char EscMap[33];
122
123void
124HdlcInit()
125{
126  ifInOctets = ifOutOctets = 0;
127  ifInPackets = ifOutPackets = 0;
128  ifOutLQRs = 0;
129}
130
131/*
132 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
133 *  2.27 for further details.
134 */
135inline u_short
136HdlcFcs(u_short fcs, u_char * cp, int len)
137{
138  while (len--)
139    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
140  return (fcs);
141}
142
143void
144HdlcOutput(int pri, u_short proto, struct mbuf * bp)
145{
146  struct mbuf *mhp, *mfcs;
147  struct protostat *statp;
148  struct lqrdata *lqr;
149  u_char *cp;
150  u_short fcs;
151
152  if ((proto & 0xfff1) == 0x21) {	/* Network Layer protocol */
153    if (CcpFsm.state == ST_OPENED) {
154      if (CcpInfo.want_proto == TY_PRED1) {
155        Pred1Output(pri, proto, bp);
156        return;
157      }
158    }
159  }
160  if (DEV_IS_SYNC)
161    mfcs = NULLBUFF;
162  else
163    mfcs = mballoc(2, MB_HDLCOUT);
164  mhp = mballoc(4, MB_HDLCOUT);
165  mhp->cnt = 0;
166  cp = MBUF_CTOP(mhp);
167  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
168    *cp++ = HDLC_ADDR;
169    *cp++ = HDLC_UI;
170    mhp->cnt += 2;
171  }
172
173  /*
174   * If possible, compress protocol field.
175   */
176  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
177    *cp++ = proto;
178    mhp->cnt++;
179  } else {
180    *cp++ = proto >> 8;
181    *cp = proto & 0377;
182    mhp->cnt += 2;
183  }
184  mhp->next = bp;
185  bp->next = mfcs;
186
187  lqr = &MyLqrData;
188  lqr->PeerOutPackets = ifOutPackets++;
189  ifOutOctets += plength(mhp) + 1;
190  lqr->PeerOutOctets = ifOutOctets;
191
192  if (proto == PROTO_LQR) {
193    lqr->MagicNumber = LcpInfo.want_magic;
194    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
195    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
196    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
197    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
198    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
199    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
200    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
201    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
202    lqr->PeerOutLQRs = ++ifOutLQRs;
203    LqrDump("LqrOutput", lqr);
204    LqrChangeOrder(lqr, (struct lqrdata *) (MBUF_CTOP(bp)));
205  }
206  if (!DEV_IS_SYNC) {
207    fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
208    fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
209    fcs = ~fcs;
210    cp = MBUF_CTOP(mfcs);
211    *cp++ = fcs & 0377;		/* Low byte first!! */
212    *cp++ = fcs >> 8;
213  }
214  LogDumpBp(LogHDLC, "HdlcOutput", mhp);
215  for (statp = ProtocolStat; statp->number; statp++)
216    if (statp->number == proto)
217      break;
218  statp->out_count++;
219  if (DEV_IS_SYNC)
220    ModemOutput(pri, mhp);
221  else
222    AsyncOutput(pri, mhp, proto);
223}
224
225void
226DecodePacket(u_short proto, struct mbuf * bp)
227{
228  u_char *cp;
229
230  LogPrintf(LogDEBUG, "DecodePacket: proto = %04x\n", proto);
231
232  switch (proto) {
233  case PROTO_LCP:
234    LcpInput(bp);
235    break;
236  case PROTO_PAP:
237    PapInput(bp);
238    break;
239  case PROTO_LQR:
240    HisLqrSave.SaveInLQRs++;
241    LqrInput(bp);
242    break;
243  case PROTO_CHAP:
244    ChapInput(bp);
245    break;
246  case PROTO_VJUNCOMP:
247  case PROTO_VJCOMP:
248    bp = VjCompInput(bp, proto);
249    if (bp == NULLBUFF) {
250      break;
251    }
252    /* fall down */
253  case PROTO_IP:
254    IpInput(bp);
255    break;
256  case PROTO_IPCP:
257    IpcpInput(bp);
258    break;
259  case PROTO_CCP:
260    CcpInput(bp);
261    break;
262  case PROTO_COMPD:
263    Pred1Input(bp);
264    break;
265  default:
266    LogPrintf(LogPHASE, "Unknown protocol 0x%04x\n", proto);
267    bp->offset -= 2;
268    bp->cnt += 2;
269    cp = MBUF_CTOP(bp);
270    LcpSendProtoRej(cp, bp->cnt);
271    HisLqrSave.SaveInDiscards++;
272    HdlcStat.unknownproto++;
273    pfree(bp);
274    break;
275  }
276}
277
278int
279ReportProtStatus(struct cmdargs const *arg)
280{
281  struct protostat *statp;
282  int cnt;
283
284  statp = ProtocolStat;
285  statp--;
286  cnt = 0;
287  fprintf(VarTerm, "    Protocol     in        out      Protocol      in       out\n");
288  do {
289    statp++;
290    fprintf(VarTerm, "   %-9s: %8lu, %8lu",
291	    statp->name, statp->in_count, statp->out_count);
292    if (++cnt == 2) {
293      fprintf(VarTerm, "\n");
294      cnt = 0;
295    }
296  } while (statp->number);
297  if (cnt)
298    fprintf(VarTerm, "\n");
299  return (1);
300}
301
302int
303ReportHdlcStatus(struct cmdargs const *arg)
304{
305  struct hdlcstat *hp = &HdlcStat;
306
307  if (VarTerm) {
308    fprintf(VarTerm, "HDLC level errors\n\n");
309    fprintf(VarTerm, "FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
310	    hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
311  }
312  return 0;
313}
314
315static struct hdlcstat laststat;
316
317void
318HdlcErrorCheck()
319{
320  struct hdlcstat *hp = &HdlcStat;
321  struct hdlcstat *op = &laststat;
322
323  if (memcmp(hp, op, sizeof(laststat))) {
324    LogPrintf(LogPHASE, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
325	      hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
326      hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
327  }
328  laststat = HdlcStat;
329}
330
331void
332HdlcInput(struct mbuf * bp)
333{
334  u_short fcs, proto;
335  u_char *cp, addr, ctrl;
336  struct protostat *statp;
337
338  LogDumpBp(LogHDLC, "HdlcInput:", bp);
339  if (DEV_IS_SYNC)
340    fcs = GOODFCS;
341  else
342    fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
343  HisLqrSave.SaveInOctets += bp->cnt + 1;
344
345  LogPrintf(LogDEBUG, "HdlcInput: fcs = %04x (%s)\n",
346	    fcs, (fcs == GOODFCS) ? "good" : "bad");
347  if (fcs != GOODFCS) {
348    HisLqrSave.SaveInErrors++;
349    LogPrintf(LogDEBUG, "HdlcInput: Bad FCS\n");
350    HdlcStat.badfcs++;
351    pfree(bp);
352    return;
353  }
354  if (!DEV_IS_SYNC)
355    bp->cnt -= 2;		/* discard FCS part */
356
357  if (bp->cnt < 2) {		/* XXX: raise this bar ? */
358    pfree(bp);
359    return;
360  }
361  cp = MBUF_CTOP(bp);
362
363  ifInPackets++;
364  ifInOctets += bp->cnt;
365
366  if (!LcpInfo.want_acfcomp) {
367
368    /*
369     * We expect that packet is not compressed.
370     */
371    addr = *cp++;
372    if (addr != HDLC_ADDR) {
373      HisLqrSave.SaveInErrors++;
374      HdlcStat.badaddr++;
375      LogPrintf(LogDEBUG, "HdlcInput: addr %02x\n", *cp);
376      pfree(bp);
377      return;
378    }
379    ctrl = *cp++;
380    if (ctrl != HDLC_UI) {
381      HisLqrSave.SaveInErrors++;
382      HdlcStat.badcommand++;
383      LogPrintf(LogDEBUG, "HdlcInput: %02x\n", *cp);
384      pfree(bp);
385      return;
386    }
387    bp->offset += 2;
388    bp->cnt -= 2;
389  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
390
391    /*
392     * We can receive compressed packet, but peer still send uncompressed
393     * packet to me.
394     */
395    cp += 2;
396    bp->offset += 2;
397    bp->cnt -= 2;
398  }
399  if (LcpInfo.want_protocomp) {
400    proto = 0;
401    cp--;
402    do {
403      cp++;
404      bp->offset++;
405      bp->cnt--;
406      proto = proto << 8;
407      proto += *cp;
408    } while (!(proto & 1));
409  } else {
410    proto = *cp++ << 8;
411    proto |= *cp++;
412    bp->offset += 2;
413    bp->cnt -= 2;
414  }
415
416  for (statp = ProtocolStat; statp->number; statp++)
417    if (statp->number == proto)
418      break;
419  statp->in_count++;
420  HisLqrSave.SaveInPackets++;
421
422  DecodePacket(proto, bp);
423}
424