hdlc.c revision 22997 
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 * $Id$
21 *
22 *	TODO:
23 */
24#include "fsm.h"
25#include "hdlc.h"
26#include "lcpproto.h"
27#include "lcp.h"
28#include "lqr.h"
29#include "vars.h"
30#include "pred.h"
31#include "modem.h"
32#include "ccp.h"
33
34struct hdlcstat {
35  int	badfcs;
36  int	badaddr;
37  int	badcommand;
38  int	unknownproto;
39} HdlcStat;
40
41static int ifOutPackets, ifOutOctets, ifOutLQRs;
42static int ifInPackets, ifInOctets;
43
44struct protostat {
45  u_short number;
46  char *name;
47  u_long in_count;
48  u_long out_count;
49} ProtocolStat[] = {
50  { PROTO_IP,		"IP" },
51  { PROTO_VJUNCOMP,	"VJ_UNCOMP" },
52  { PROTO_VJCOMP,	"VJ_COMP" },
53  { PROTO_COMPD,	"COMPD" },
54  { PROTO_LCP,		"LCP" },
55  { PROTO_IPCP,		"IPCP" },
56  { PROTO_CCP,		"CCP" },
57  { PROTO_PAP,		"PAP" },
58  { PROTO_LQR,		"LQR" },
59  { PROTO_CHAP,		"CHAP" },
60  { 0,			"Others" },
61};
62
63static u_short const fcstab[256] = {
64/* 00 */    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
65/* 08 */    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
66/* 10 */    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
67/* 18 */    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
68/* 20 */    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
69/* 28 */    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
70/* 30 */    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
71/* 38 */    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
72/* 40 */    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
73/* 48 */    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
74/* 50 */    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
75/* 58 */    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
76/* 60 */    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
77/* 68 */    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
78/* 70 */    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
79/* 78 */    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
80/* 80 */    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
81/* 88 */    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
82/* 90 */    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
83/* 98 */    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
84/* a0 */    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
85/* a8 */    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
86/* b0 */    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
87/* b8 */    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
88/* c0 */    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
89/* c8 */    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
90/* d0 */    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
91/* d8 */    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
92/* e0 */    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
93/* e8 */    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
94/* f0 */    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
95/* f8 */    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
96};
97
98void
99HdlcInit()
100{
101  ifInOctets = ifOutOctets = 0;
102  ifInPackets = ifOutPackets = 0;
103  ifOutLQRs = 0;
104}
105
106/*
107 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
108 *  2.27 for further details.
109 */
110inline u_short
111HdlcFcs(fcs, cp, len)
112u_short fcs;
113u_char *cp;
114int len;
115{
116  while (len--)
117    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
118  return(fcs);
119}
120
121void
122HdlcOutput(int pri, u_short proto, struct mbuf *bp)
123{
124  struct mbuf *mhp, *mfcs;
125  struct protostat *statp;
126  struct lqrdata *lqr;
127  u_char *cp;
128  u_short fcs;
129
130  if ((proto & 0xfff1) == 0x21) {	/* Network Layer protocol */
131    if (CcpFsm.state == ST_OPENED) {
132      Pred1Output(pri, proto, bp);
133      return;
134    }
135  }
136  if (DEV_IS_SYNC)
137    mfcs = NULLBUFF;
138  else
139    mfcs = mballoc(2, MB_HDLCOUT);
140  mhp = mballoc(4, MB_HDLCOUT);
141  mhp->cnt = 0;
142  cp = MBUF_CTOP(mhp);
143  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
144    *cp++ = HDLC_ADDR;
145    *cp++ = HDLC_UI;
146    mhp->cnt += 2;
147  }
148  /*
149   *  If possible, compress protocol field.
150   */
151  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
152    *cp++ = proto;
153    mhp->cnt++;
154  } else {
155    *cp++ = proto >> 8;
156    *cp = proto & 0377;
157    mhp->cnt += 2;
158  }
159  mhp->next = bp;
160  bp->next = mfcs;
161
162  lqr = &MyLqrData;
163  lqr->PeerOutPackets = ifOutPackets++;
164  ifOutOctets += plength(mhp) + 1;
165  lqr->PeerOutOctets = ifOutOctets;
166
167  if (proto == PROTO_LQR) {
168    lqr->MagicNumber = LcpInfo.want_magic;
169    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
170    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
171    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
172    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
173    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
174    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
175    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
176    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
177    lqr->PeerOutLQRs = ++ifOutLQRs;
178    LqrDump("LqrOutput", lqr);
179    LqrChangeOrder(lqr, (struct lqrdata *)(MBUF_CTOP(bp)));
180  }
181
182  if (!DEV_IS_SYNC) {
183    fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
184    fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
185    fcs = ~fcs;
186    cp = MBUF_CTOP(mfcs);
187    *cp++ = fcs & 0377;	/* Low byte first!! */
188    *cp++ = fcs >> 8;
189  }
190
191  LogDumpBp(LOG_HDLC, "HdlcOutput", mhp);
192  for (statp = ProtocolStat; statp->number; statp++)
193    if (statp->number == proto)
194      break;
195  statp->out_count++;
196  if (DEV_IS_SYNC)
197    ModemOutput(pri, mhp);
198  else
199    AsyncOutput(pri, mhp, proto);
200}
201
202void
203DecodePacket(proto, bp)
204u_short proto;
205struct mbuf *bp;
206{
207#ifdef DEBUG
208  logprintf("proto = %04x\n", proto);
209#endif
210  u_char *cp;
211
212  switch (proto) {
213  case PROTO_LCP:
214    LcpInput(bp);
215    break;
216  case PROTO_PAP:
217    PapInput(bp);
218    break;
219  case PROTO_LQR:
220    HisLqrSave.SaveInLQRs++;
221    LqrInput(bp);
222    break;
223  case PROTO_CHAP:
224    ChapInput(bp);
225    break;
226  case PROTO_VJUNCOMP:
227  case PROTO_VJCOMP:
228    bp = VjCompInput(bp, proto);
229    if (bp == NULLBUFF) {
230      break;
231    }
232    /* fall down */
233  case PROTO_IP:
234    IpInput(bp);
235    break;
236  case PROTO_IPCP:
237    IpcpInput(bp);
238    break;
239  case PROTO_CCP:
240    CcpInput(bp);
241    break;
242  case PROTO_COMPD:
243    Pred1Input(bp);
244    break;
245  default:
246    LogPrintf(LOG_PHASE_BIT, "Unknown protocol 0x%04x\n", proto);
247    bp->offset -= 2;
248    bp->cnt += 2;
249    cp = MBUF_CTOP(bp);
250    LcpSendProtoRej(cp,  bp->cnt);
251    HisLqrSave.SaveInDiscards++;
252    HdlcStat.unknownproto++;
253    pfree(bp);
254    break;
255  }
256}
257
258int
259ReportProtStatus()
260{
261  struct protostat *statp;
262  int cnt;
263
264  statp = ProtocolStat;
265  statp--;
266  cnt = 0;
267  printf("    Protocol     in        out      Protocol      in       out\n");
268  do {
269    statp++;
270    printf("   %-9s: %8lu, %8lu",
271      statp->name, statp->in_count, statp->out_count);
272    if (++cnt == 2) {
273      printf("\n");
274      cnt = 0;
275    }
276  } while (statp->number);
277  if (cnt)
278     printf("\n");
279  return(1);
280}
281
282int
283ReportHdlcStatus()
284{
285  struct hdlcstat *hp = &HdlcStat;
286
287  printf("HDLC level errors\n\n");
288  printf("FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
289	hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
290  return(1);
291}
292
293static struct hdlcstat laststat;
294
295void
296HdlcErrorCheck()
297{
298  struct hdlcstat *hp = &HdlcStat;
299  struct hdlcstat *op = &laststat;
300
301  if (bcmp(hp, op, sizeof(laststat))) {
302    LogPrintf(LOG_PHASE_BIT, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
303	hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
304	hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
305  }
306  laststat = HdlcStat;
307}
308
309void
310HdlcInput(struct mbuf *bp)
311{
312  u_short fcs, proto;
313  u_char *cp, addr, ctrl;
314  struct protostat *statp;
315
316  LogDumpBp(LOG_HDLC, "HdlcInput:", bp);
317  if (DEV_IS_SYNC)
318    fcs = GOODFCS;
319  else
320    fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
321  HisLqrSave.SaveInOctets += bp->cnt + 1;
322
323#ifdef DEBUG
324  logprintf("fcs = %04x (%s)\n", fcs, (fcs == GOODFCS)? "good" : "bad");
325#endif
326  if (fcs != GOODFCS) {
327    HisLqrSave.SaveInErrors++;
328#ifdef DEBUG
329    logprintf("Bad FCS\n");
330#endif
331    HdlcStat.badfcs++;
332    pfree(bp);
333    return;
334  }
335  if (!DEV_IS_SYNC)
336    bp->cnt -= 2;		/* discard FCS part */
337  cp = MBUF_CTOP(bp);
338
339  ifInPackets++;
340  ifInOctets += bp->cnt;
341
342  if (!LcpInfo.want_acfcomp) {
343    /*
344     *  We expect that packet is not compressed.
345     */
346    addr = *cp++;
347    if (addr != HDLC_ADDR) {
348      HisLqrSave.SaveInErrors++;
349      HdlcStat.badaddr++;
350#ifdef DEBUG
351      logprintf("addr %02x\n", *cp);
352#endif
353      pfree(bp);
354      return;
355    }
356
357    ctrl = *cp++;
358    if (ctrl != HDLC_UI) {
359      HisLqrSave.SaveInErrors++;
360      HdlcStat.badcommand++;
361#ifdef DEBUG
362      logprintf("command %02x\n", *cp);
363#endif
364      pfree(bp);
365      return;
366    }
367    bp->offset += 2;
368    bp->cnt -= 2;
369  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
370    /*
371     *  We can receive compressed packet, but peer still send
372     *  uncompressed packet to me.
373     */
374    cp += 2;
375    bp->offset += 2;
376    bp->cnt -= 2;
377  }
378
379  if (LcpInfo.want_protocomp) {
380    proto = 0;
381    cp--;
382    do {
383      cp++; bp->offset++; bp->cnt--;
384      proto = proto << 8;
385      proto += *cp;
386    } while (!(proto & 1));
387  } else {
388    proto = *cp++ << 8;
389    proto |= *cp++;
390    bp->offset += 2;
391    bp->cnt -= 2;
392  }
393
394  for (statp = ProtocolStat; statp->number; statp++)
395    if (statp->number == proto)
396      break;
397  statp->in_count++;
398  HisLqrSave.SaveInPackets++;
399
400  DecodePacket(proto, bp);
401}
402