hdlc.c revision 6059 
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
30struct hdlcstat {
31  int	badfcs;
32  int	badaddr;
33  int	badcommand;
34  int	unknownproto;
35} HdlcStat;
36
37static int ifOutPackets, ifOutOctets, ifOutLQRs;
38static int ifInPackets, ifInOctets;
39
40struct protostat {
41  u_short number;
42  char *name;
43  u_long in_count;
44  u_long out_count;
45} ProtocolStat[] = {
46  { PROTO_IP,		"IP" },
47  { PROTO_VJUNCOMP,	"VJ_UNCOMP" },
48  { PROTO_VJCOMP,	"VJ_COMP" },
49  { PROTO_COMPD,	"COMPD" },
50  { PROTO_LCP,		"LCP" },
51  { PROTO_IPCP,		"IPCP" },
52  { PROTO_CCP,		"CCP" },
53  { PROTO_PAP,		"PAP" },
54  { PROTO_LQR,		"LQR" },
55  { PROTO_CHAP,		"CHAP" },
56  { 0,			"Others" },
57};
58
59static u_short fcstab[256] = {
60/* 00 */    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
61/* 08 */    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
62/* 10 */    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
63/* 18 */    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
64/* 20 */    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
65/* 28 */    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
66/* 30 */    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
67/* 38 */    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
68/* 40 */    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
69/* 48 */    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
70/* 50 */    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
71/* 58 */    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
72/* 60 */    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
73/* 68 */    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
74/* 70 */    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
75/* 78 */    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
76/* 80 */    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
77/* 88 */    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
78/* 90 */    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
79/* 98 */    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
80/* a0 */    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
81/* a8 */    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
82/* b0 */    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
83/* b8 */    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
84/* c0 */    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
85/* c8 */    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
86/* d0 */    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
87/* d8 */    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
88/* e0 */    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
89/* e8 */    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
90/* f0 */    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
91/* f8 */    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
92};
93
94void
95HdlcInit()
96{
97  ifInOctets = ifOutOctets = 0;
98  ifInPackets = ifOutPackets = 0;
99  ifOutLQRs = 0;
100}
101
102/*
103 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
104 *  2.27 for further details.
105 */
106u_short
107HdlcFcs(fcs, cp, len)
108u_short fcs;
109u_char *cp;
110int len;
111{
112  while (len--)
113    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
114  return(fcs);
115}
116
117void
118HdlcOutput(int pri, u_short proto, struct mbuf *bp)
119{
120  struct mbuf *mhp, *mfcs;
121  struct protostat *statp;
122  struct lqrdata *lqr;
123  u_char *cp;
124  u_short fcs;
125
126  if ((proto & 0xfff1) == 0x21) {	/* Network Layer protocol */
127    if (CcpFsm.state == ST_OPENED) {
128      Pred1Output(pri, proto, bp);
129      return;
130    }
131  }
132  mfcs = mballoc(2, MB_HDLCOUT);
133  mhp = mballoc(4, MB_HDLCOUT);
134  mhp->cnt = 0;
135  cp = MBUF_CTOP(mhp);
136  if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) {
137    *cp++ = HDLC_ADDR;
138    *cp++ = HDLC_UI;
139    mhp->cnt += 2;
140  }
141  /*
142   *  If possible, compress protocol field.
143   */
144  if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) {
145    *cp++ = proto;
146    mhp->cnt++;
147  } else {
148    *cp++ = proto >> 8;
149    *cp = proto & 0377;
150    mhp->cnt += 2;
151  }
152  mhp->next = bp;
153  bp->next = mfcs;
154
155  lqr = &MyLqrData;
156  lqr->PeerOutPackets = ifOutPackets++;
157  ifOutOctets += plength(mhp) + 1;
158  lqr->PeerOutOctets = ifOutOctets;
159
160  if (proto == PROTO_LQR) {
161    lqr->MagicNumber = LcpInfo.want_magic;
162    lqr->LastOutLQRs = HisLqrData.PeerOutLQRs;
163    lqr->LastOutPackets = HisLqrData.PeerOutPackets;
164    lqr->LastOutOctets = HisLqrData.PeerOutOctets;
165    lqr->PeerInLQRs = HisLqrSave.SaveInLQRs;
166    lqr->PeerInPackets = HisLqrSave.SaveInPackets;
167    lqr->PeerInDiscards = HisLqrSave.SaveInDiscards;
168    lqr->PeerInErrors = HisLqrSave.SaveInErrors;
169    lqr->PeerInOctets = HisLqrSave.SaveInOctets;
170    lqr->PeerOutLQRs = ++ifOutLQRs;
171    LqrDump("LqrOutput", lqr);
172    LqrChangeOrder(lqr, (struct lqrdata *)(MBUF_CTOP(bp)));
173  }
174
175  fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt);
176  fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt);
177  fcs = ~fcs;
178  cp = MBUF_CTOP(mfcs);
179  *cp++ = fcs & 0377;	/* Low byte first!! */
180  *cp++ = fcs >> 8;
181
182  LogDumpBp(LOG_HDLC, "HdlcOutput", mhp);
183  for (statp = ProtocolStat; statp->number; statp++)
184    if (statp->number == proto)
185      break;
186  statp->out_count++;
187  AsyncOutput(pri, mhp, proto);
188}
189
190DecodePacket(proto, bp)
191u_short proto;
192struct mbuf *bp;
193{
194#ifdef DEBUG
195  logprintf("proto = %04x\n", proto);
196#endif
197  switch (proto) {
198  case PROTO_LCP:
199    LcpInput(bp);
200    break;
201  case PROTO_PAP:
202    PapInput(bp);
203    break;
204  case PROTO_LQR:
205    HisLqrSave.SaveInLQRs++;
206    LqrInput(bp);
207    break;
208  case PROTO_CHAP:
209    ChapInput(bp);
210    break;
211  case PROTO_VJUNCOMP:
212  case PROTO_VJCOMP:
213    bp = VjCompInput(bp, proto);
214    /* fall down */
215  case PROTO_IP:
216    IpInput(bp);
217    break;
218  case PROTO_IPCP:
219    IpcpInput(bp);
220    break;
221  case PROTO_CCP:
222    CcpInput(bp);
223    break;
224  case PROTO_COMPD:
225    Pred1Input(bp);
226    break;
227  default:
228    logprintf("Unknown protocol 0x%04x\n", proto);
229    /*
230     * XXX: Should send protocol reject.
231     */
232    HisLqrSave.SaveInDiscards++;
233    HdlcStat.unknownproto++;
234    pfree(bp);
235    break;
236  }
237}
238
239int
240ReportProtStatus()
241{
242  struct protostat *statp;
243  int cnt;
244
245  statp = ProtocolStat;
246  statp--;
247  cnt = 0;
248  printf("    Protocol     in        out      Protocol      in       out\n");
249  do {
250    statp++;
251    printf("   %-9s: %8u, %8u",
252      statp->name, statp->in_count, statp->out_count);
253    if (++cnt == 2) {
254      printf("\n");
255      cnt = 0;
256    }
257  } while (statp->number);
258  if (cnt)
259     printf("\n");
260  return(1);
261}
262
263int
264ReportHdlcStatus()
265{
266  struct hdlcstat *hp = &HdlcStat;
267
268  printf("HDLC level errors\n\n");
269  printf("FCS: %u  ADDR: %u  COMMAND: %u  PROTO: %u\n",
270	hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto);
271  return(1);
272}
273
274static struct hdlcstat laststat;
275
276void
277HdlcErrorCheck()
278{
279  struct hdlcstat *hp = &HdlcStat;
280  struct hdlcstat *op = &laststat;
281
282  if (bcmp(hp, op, sizeof(laststat))) {
283    LogPrintf(LOG_PHASE, "HDLC errros -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n",
284	hp->badfcs - op->badfcs, hp->badaddr - op->badaddr,
285	hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto);
286  }
287  laststat = HdlcStat;
288}
289
290void
291HdlcInput(struct mbuf *bp)
292{
293  u_short fcs, proto;
294  u_char *cp, addr, ctrl;
295  struct protostat *statp;
296
297  LogDumpBp(LOG_HDLC, "HdlcInput:", bp);
298  fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
299  HisLqrSave.SaveInOctets += bp->cnt + 1;
300
301#ifdef DEBUG
302  logprintf("fcs = %04x (%s)\n", fcs, (fcs == GOODFCS)? "good" : "bad");
303#endif
304  if (fcs != GOODFCS) {
305    HisLqrSave.SaveInErrors++;
306#ifdef DEBUG
307    logprintf("Bad FCS\n");
308#endif
309    HdlcStat.badfcs++;
310    pfree(bp);
311    return;
312  }
313  bp->cnt -= 2;		/* discard FCS part */
314  cp = MBUF_CTOP(bp);
315
316  ifInPackets++;
317  ifInOctets += bp->cnt;
318
319  if (!LcpInfo.want_acfcomp) {
320    /*
321     *  We expect that packet is not compressed.
322     */
323    addr = *cp++;
324    if (addr != HDLC_ADDR) {
325      HisLqrSave.SaveInErrors++;
326      HdlcStat.badaddr++;
327#ifdef DEBUG
328      logprintf("addr %02x\n", *cp);
329#endif
330      pfree(bp);
331      return;
332    }
333
334    ctrl = *cp++;
335    if (ctrl != HDLC_UI) {
336      HisLqrSave.SaveInErrors++;
337      HdlcStat.badcommand++;
338#ifdef DEBUG
339      logprintf("command %02x\n", *cp);
340#endif
341      pfree(bp);
342      return;
343    }
344    bp->offset += 2;
345    bp->cnt -= 2;
346  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
347    /*
348     *  We can receive compressed packet, but peer still send
349     *  uncompressed packet to me.
350     */
351    cp += 2;
352    bp->offset += 2;
353    bp->cnt -= 2;
354  }
355
356  if (LcpInfo.want_protocomp) {
357    proto = 0;
358    cp--;
359    do {
360      cp++; bp->offset++; bp->cnt--;
361      proto = proto << 8;
362      proto += *cp;
363    } while (!(proto & 1));
364  } else {
365    proto = *cp++ << 8;
366    proto |= *cp++;
367    bp->offset += 2;
368    bp->cnt -= 2;
369  }
370
371  for (statp = ProtocolStat; statp->number; statp++)
372    if (statp->number == proto)
373      break;
374  statp->in_count++;
375  HisLqrSave.SaveInPackets++;
376
377  DecodePacket(proto, bp);
378}
379