hdlc.c revision 43693 
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 1.37 1999/01/28 01:56:32 brian Exp $
21 *
22 *	TODO:
23 */
24#include <sys/param.h>
25#include <netinet/in.h>
26#include <netinet/in_systm.h>
27#include <netinet/ip.h>
28#include <sys/un.h>
29
30#include <stdio.h>
31#include <string.h>
32#include <termios.h>
33
34#include "defs.h"
35#include "command.h"
36#include "mbuf.h"
37#include "log.h"
38#include "timer.h"
39#include "fsm.h"
40#include "lqr.h"
41#include "hdlc.h"
42#include "lcpproto.h"
43#include "iplist.h"
44#include "throughput.h"
45#include "slcompress.h"
46#include "ipcp.h"
47#include "ip.h"
48#include "vjcomp.h"
49#include "auth.h"
50#include "pap.h"
51#include "chap.h"
52#include "lcp.h"
53#include "async.h"
54#include "ccp.h"
55#include "link.h"
56#include "descriptor.h"
57#include "physical.h"
58#include "prompt.h"
59#include "chat.h"
60#include "mp.h"
61#include "cbcp.h"
62#include "datalink.h"
63#include "filter.h"
64#ifndef NORADIUS
65#include "radius.h"
66#endif
67#include "bundle.h"
68
69static u_int16_t const fcstab[256] = {
70   /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
71   /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
72   /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
73   /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
74   /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
75   /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
76   /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
77   /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
78   /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
79   /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
80   /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
81   /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
82   /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
83   /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
84   /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
85   /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
86   /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
87   /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
88   /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
89   /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
90   /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
91   /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
92   /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
93   /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
94   /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
95   /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
96   /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
97   /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
98   /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
99   /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
100   /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
101   /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
102};
103
104void
105hdlc_Init(struct hdlc *hdlc, struct lcp *lcp)
106{
107  memset(hdlc, '\0', sizeof(struct hdlc));
108  hdlc->lqm.owner = lcp;
109}
110
111/*
112 *  HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section
113 *  2.27 for further details.
114 */
115inline u_short
116hdlc_Fcs(u_short fcs, u_char * cp, int len)
117{
118  while (len--)
119    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff];
120  return (fcs);
121}
122
123static inline u_short
124HdlcFcsBuf(u_short fcs, struct mbuf *m)
125{
126  int len;
127  u_char *pos, *end;
128
129  len = mbuf_Length(m);
130  pos = MBUF_CTOP(m);
131  end = pos + m->cnt;
132  while (len--) {
133    fcs = (fcs >> 8) ^ fcstab[(fcs ^ *pos++) & 0xff];
134    if (pos == end && len) {
135      m = m->next;
136      pos = MBUF_CTOP(m);
137      end = pos + m->cnt;
138    }
139  }
140  return (fcs);
141}
142
143void
144hdlc_Output(struct link *l, int pri, u_short proto, struct mbuf *bp)
145{
146  struct physical *p = link2physical(l);
147  struct mbuf *mhp, *mfcs;
148  u_char *cp;
149  u_short fcs;
150
151  if (!p || physical_IsSync(p))
152    mfcs = NULL;
153  else
154    mfcs = mbuf_Alloc(2, MB_HDLCOUT);
155
156  mhp = mbuf_Alloc(4, MB_HDLCOUT);
157  mhp->cnt = 0;
158  cp = MBUF_CTOP(mhp);
159  if (p && (proto == PROTO_LCP || l->lcp.his_acfcomp == 0)) {
160    *cp++ = HDLC_ADDR;
161    *cp++ = HDLC_UI;
162    mhp->cnt += 2;
163  }
164
165  /*
166   * If possible, compress protocol field.
167   */
168  if (l->lcp.his_protocomp && (proto & 0xff00) == 0) {
169    *cp++ = proto;
170    mhp->cnt++;
171  } else {
172    *cp++ = proto >> 8;
173    *cp = proto & 0377;
174    mhp->cnt += 2;
175  }
176
177  mhp->next = bp;
178
179  if (!p) {
180    /*
181     * This is where we multiplex the data over our available physical
182     * links.  We don't frame our logical link data.  Instead we wait
183     * for the logical link implementation to chop our data up and pile
184     * it into the physical links by re-calling this function with the
185     * encapsulated fragments.
186     */
187    link_Output(l, pri, mhp);
188    return;
189  }
190
191  /* Tack mfcs onto the end, then set bp back to the start of the data */
192  while (bp->next != NULL)
193    bp = bp->next;
194  bp->next = mfcs;
195  bp = mhp->next;
196
197  p->hdlc.lqm.OutOctets += mbuf_Length(mhp) + 1;
198  p->hdlc.lqm.OutPackets++;
199
200  if (proto == PROTO_LQR) {
201    /* Overwrite the entire packet */
202    struct lqrdata lqr;
203
204    lqr.MagicNumber = p->link.lcp.want_magic;
205    lqr.LastOutLQRs = p->hdlc.lqm.lqr.peer.PeerOutLQRs;
206    lqr.LastOutPackets = p->hdlc.lqm.lqr.peer.PeerOutPackets;
207    lqr.LastOutOctets = p->hdlc.lqm.lqr.peer.PeerOutOctets;
208    lqr.PeerInLQRs = p->hdlc.lqm.lqr.SaveInLQRs;
209    lqr.PeerInPackets = p->hdlc.lqm.SaveInPackets;
210    lqr.PeerInDiscards = p->hdlc.lqm.SaveInDiscards;
211    lqr.PeerInErrors = p->hdlc.lqm.SaveInErrors;
212    lqr.PeerInOctets = p->hdlc.lqm.SaveInOctets;
213    lqr.PeerOutPackets = p->hdlc.lqm.OutPackets;
214    lqr.PeerOutOctets = p->hdlc.lqm.OutOctets;
215    if (p->hdlc.lqm.lqr.peer.LastOutLQRs == p->hdlc.lqm.lqr.OutLQRs) {
216      /*
217       * only increment if it's the first time or we've got a reply
218       * from the last one
219       */
220      lqr.PeerOutLQRs = ++p->hdlc.lqm.lqr.OutLQRs;
221      lqr_Dump(l->name, "Output", &lqr);
222    } else {
223      lqr.PeerOutLQRs = p->hdlc.lqm.lqr.OutLQRs;
224      lqr_Dump(l->name, "Output (again)", &lqr);
225    }
226    lqr_ChangeOrder(&lqr, (struct lqrdata *)MBUF_CTOP(bp));
227  }
228
229  if (mfcs) {
230    mfcs->cnt = 0;
231    fcs = HdlcFcsBuf(INITFCS, mhp);
232    fcs = ~fcs;
233    cp = MBUF_CTOP(mfcs);
234    *cp++ = fcs & 0377;		/* Low byte first!! */
235    *cp++ = fcs >> 8;
236    mfcs->cnt = 2;
237  }
238
239  log_DumpBp(LogHDLC, "hdlc_Output", mhp);
240
241  link_ProtocolRecord(l, proto, PROTO_OUT);
242  log_Printf(LogDEBUG, "hdlc_Output: proto = 0x%04x\n", proto);
243
244  if (physical_IsSync(p))
245    link_Output(l, pri, mhp);          /* Send it raw */
246  else
247    async_Output(pri, mhp, proto, p);
248}
249
250/* Check out the latest ``Assigned numbers'' rfc (rfc1700.txt) */
251static struct {
252  u_short from;
253  u_short to;
254  const char *name;
255} protocols[] = {
256  { 0x0001, 0x0001, "Padding Protocol" },
257  { 0x0003, 0x001f, "reserved (transparency inefficient)" },
258  { 0x0021, 0x0021, "Internet Protocol" },
259  { 0x0023, 0x0023, "OSI Network Layer" },
260  { 0x0025, 0x0025, "Xerox NS IDP" },
261  { 0x0027, 0x0027, "DECnet Phase IV" },
262  { 0x0029, 0x0029, "Appletalk" },
263  { 0x002b, 0x002b, "Novell IPX" },
264  { 0x002d, 0x002d, "Van Jacobson Compressed TCP/IP" },
265  { 0x002f, 0x002f, "Van Jacobson Uncompressed TCP/IP" },
266  { 0x0031, 0x0031, "Bridging PDU" },
267  { 0x0033, 0x0033, "Stream Protocol (ST-II)" },
268  { 0x0035, 0x0035, "Banyan Vines" },
269  { 0x0037, 0x0037, "reserved (until 1993)" },
270  { 0x0039, 0x0039, "AppleTalk EDDP" },
271  { 0x003b, 0x003b, "AppleTalk SmartBuffered" },
272  { 0x003d, 0x003d, "Multi-Link" },
273  { 0x003f, 0x003f, "NETBIOS Framing" },
274  { 0x0041, 0x0041, "Cisco Systems" },
275  { 0x0043, 0x0043, "Ascom Timeplex" },
276  { 0x0045, 0x0045, "Fujitsu Link Backup and Load Balancing (LBLB)" },
277  { 0x0047, 0x0047, "DCA Remote Lan" },
278  { 0x0049, 0x0049, "Serial Data Transport Protocol (PPP-SDTP)" },
279  { 0x004b, 0x004b, "SNA over 802.2" },
280  { 0x004d, 0x004d, "SNA" },
281  { 0x004f, 0x004f, "IP6 Header Compression" },
282  { 0x0051, 0x0051, "KNX Bridging Data" },
283  { 0x0053, 0x0053, "Encryption" },
284  { 0x0055, 0x0055, "Individual Link Encryption" },
285  { 0x006f, 0x006f, "Stampede Bridging" },
286  { 0x0071, 0x0071, "BAP Bandwidth Allocation Protocol" },
287  { 0x0073, 0x0073, "MP+ Protocol" },
288  { 0x007d, 0x007d, "reserved (Control Escape)" },
289  { 0x007f, 0x007f, "reserved (compression inefficient)" },
290  { 0x00cf, 0x00cf, "reserved (PPP NLPID)" },
291  { 0x00fb, 0x00fb, "compression on single link in multilink group" },
292  { 0x00fd, 0x00fd, "1st choice compression" },
293  { 0x00ff, 0x00ff, "reserved (compression inefficient)" },
294  { 0x0200, 0x02ff, "(compression inefficient)" },
295  { 0x0201, 0x0201, "802.1d Hello Packets" },
296  { 0x0203, 0x0203, "IBM Source Routing BPDU" },
297  { 0x0205, 0x0205, "DEC LANBridge100 Spanning Tree" },
298  { 0x0207, 0x0207, "Cisco Discovery Protocol" },
299  { 0x0209, 0x0209, "Netcs Twin Routing" },
300  { 0x0231, 0x0231, "Luxcom" },
301  { 0x0233, 0x0233, "Sigma Network Systems" },
302  { 0x0235, 0x0235, "Apple Client Server Protocol" },
303  { 0x1e00, 0x1eff, "(compression inefficient)" },
304  { 0x4001, 0x4001, "Cray Communications Control Protocol" },
305  { 0x4003, 0x4003, "CDPD Mobile Network Registration Protocol" },
306  { 0x4021, 0x4021, "Stacker LZS" },
307  { 0x8001, 0x801f, "Not Used - reserved" },
308  { 0x8021, 0x8021, "Internet Protocol Control Protocol" },
309  { 0x8023, 0x8023, "OSI Network Layer Control Protocol" },
310  { 0x8025, 0x8025, "Xerox NS IDP Control Protocol" },
311  { 0x8027, 0x8027, "DECnet Phase IV Control Protocol" },
312  { 0x8029, 0x8029, "Appletalk Control Protocol" },
313  { 0x802b, 0x802b, "Novell IPX Control Protocol" },
314  { 0x802d, 0x802d, "reserved" },
315  { 0x802f, 0x802f, "reserved" },
316  { 0x8031, 0x8031, "Bridging NCP" },
317  { 0x8033, 0x8033, "Stream Protocol Control Protocol" },
318  { 0x8035, 0x8035, "Banyan Vines Control Protocol" },
319  { 0x8037, 0x8037, "reserved till 1993" },
320  { 0x8039, 0x8039, "reserved" },
321  { 0x803b, 0x803b, "reserved" },
322  { 0x803d, 0x803d, "Multi-Link Control Protocol" },
323  { 0x803f, 0x803f, "NETBIOS Framing Control Protocol" },
324  { 0x8041, 0x8041, "Cisco Systems Control Protocol" },
325  { 0x8043, 0x8043, "Ascom Timeplex" },
326  { 0x8045, 0x8045, "Fujitsu LBLB Control Protocol" },
327  { 0x8047, 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" },
328  { 0x8049, 0x8049, "Serial Data Control Protocol (PPP-SDCP)" },
329  { 0x804b, 0x804b, "SNA over 802.2 Control Protocol" },
330  { 0x804d, 0x804d, "SNA Control Protocol" },
331  { 0x804f, 0x804f, "IP6 Header Compression Control Protocol" },
332  { 0x8051, 0x8051, "KNX Bridging Control Protocol" },
333  { 0x8053, 0x8053, "Encryption Control Protocol" },
334  { 0x8055, 0x8055, "Individual Link Encryption Control Protocol" },
335  { 0x806f, 0x806f, "Stampede Bridging Control Protocol" },
336  { 0x8073, 0x8073, "MP+ Control Protocol" },
337  { 0x8071, 0x8071, "BACP Bandwidth Allocation Control Protocol" },
338  { 0x807d, 0x807d, "Not Used - reserved" },
339  { 0x80cf, 0x80cf, "Not Used - reserved" },
340  { 0x80fb, 0x80fb, "compression on single link in multilink group control" },
341  { 0x80fd, 0x80fd, "Compression Control Protocol" },
342  { 0x80ff, 0x80ff, "Not Used - reserved" },
343  { 0x8207, 0x8207, "Cisco Discovery Protocol Control" },
344  { 0x8209, 0x8209, "Netcs Twin Routing" },
345  { 0x8235, 0x8235, "Apple Client Server Protocol Control" },
346  { 0xc021, 0xc021, "Link Control Protocol" },
347  { 0xc023, 0xc023, "Password Authentication Protocol" },
348  { 0xc025, 0xc025, "Link Quality Report" },
349  { 0xc027, 0xc027, "Shiva Password Authentication Protocol" },
350  { 0xc029, 0xc029, "CallBack Control Protocol (CBCP)" },
351  { 0xc081, 0xc081, "Container Control Protocol" },
352  { 0xc223, 0xc223, "Challenge Handshake Authentication Protocol" },
353  { 0xc225, 0xc225, "RSA Authentication Protocol" },
354  { 0xc227, 0xc227, "Extensible Authentication Protocol" },
355  { 0xc26f, 0xc26f, "Stampede Bridging Authorization Protocol" },
356  { 0xc281, 0xc281, "Proprietary Authentication Protocol" },
357  { 0xc283, 0xc283, "Proprietary Authentication Protocol" },
358  { 0xc481, 0xc481, "Proprietary Node ID Authentication Protocol" }
359};
360
361#define NPROTOCOLS (sizeof protocols/sizeof protocols[0])
362
363const char *
364hdlc_Protocol2Nam(u_short proto)
365{
366  int f;
367
368  for (f = 0; f < NPROTOCOLS; f++)
369    if (proto >= protocols[f].from && proto <= protocols[f].to)
370      return protocols[f].name;
371    else if (proto < protocols[f].from)
372      break;
373  return "unrecognised protocol";
374}
375
376void
377hdlc_DecodePacket(struct bundle *bundle, u_short proto, struct mbuf * bp,
378                  struct link *l)
379{
380  struct physical *p = link2physical(l);
381  u_char *cp;
382  const char *type;
383
384  log_Printf(LogDEBUG, "DecodePacket: proto = 0x%04x\n", proto);
385
386  /* decompress everything.  CCP needs uncompressed data too */
387  if ((bp = ccp_Decompress(&l->ccp, &proto, bp)) == NULL)
388    return;
389
390  switch (proto) {
391  case PROTO_LCP:
392    lcp_Input(&l->lcp, bp);
393    break;
394  case PROTO_PAP:
395    if (p)
396      pap_Input(p, bp);
397    else {
398      log_Printf(LogERROR, "DecodePacket: PAP: Not a physical link !\n");
399      mbuf_Free(bp);
400    }
401    break;
402  case PROTO_CBCP:
403    if (p)
404      cbcp_Input(p, bp);
405    else {
406      log_Printf(LogERROR, "DecodePacket: CBCP: Not a physical link !\n");
407      mbuf_Free(bp);
408    }
409    break;
410  case PROTO_LQR:
411    if (p) {
412      p->hdlc.lqm.lqr.SaveInLQRs++;
413      lqr_Input(p, bp);
414    } else {
415      log_Printf(LogERROR, "DecodePacket: LQR: Not a physical link !\n");
416      mbuf_Free(bp);
417    }
418    break;
419  case PROTO_CHAP:
420    if (p)
421      chap_Input(p, bp);
422    else {
423      log_Printf(LogERROR, "DecodePacket: CHAP: Not a physical link !\n");
424      mbuf_Free(bp);
425    }
426    break;
427  case PROTO_VJUNCOMP:
428  case PROTO_VJCOMP:
429    bp = vj_Input(&bundle->ncp.ipcp, bp, proto);
430    if (bp == NULL)
431      break;
432    /* fall down */
433  case PROTO_IP:
434    ip_Input(bundle, bp);
435    break;
436  case PROTO_IPCP:
437    ipcp_Input(&bundle->ncp.ipcp, bundle, bp);
438    break;
439  case PROTO_CCP:
440    ccp_Input(&l->ccp, bundle, bp);
441    break;
442  case PROTO_MP:
443    if (bundle->ncp.mp.active) {
444      if (p)
445        mp_Input(&bundle->ncp.mp, bp, p);
446      else {
447        log_Printf(LogWARN, "DecodePacket: Can't do MP inside MP !\n");
448        mbuf_Free(bp);
449      }
450      break;
451    }
452    /* Fall through */
453  default:
454    switch (proto) {
455      case PROTO_MP:
456      case PROTO_COMPD:
457      case PROTO_ICOMPD:
458        type = "Unexpected";
459        break;
460      default:
461        type = "Unknown";
462        break;
463    }
464    log_Printf(LogPHASE, "%s protocol 0x%04x (%s)\n", type, proto,
465               hdlc_Protocol2Nam(proto));
466    bp->offset -= 2;
467    bp->cnt += 2;
468    cp = MBUF_CTOP(bp);
469    lcp_SendProtoRej(&l->lcp, cp, bp->cnt);
470    if (p) {
471      p->hdlc.lqm.SaveInDiscards++;
472      p->hdlc.stats.unknownproto++;
473    }
474    mbuf_Free(bp);
475    break;
476  }
477}
478
479static int
480hdlc_GetProto(const u_char *cp, u_short *proto)
481{
482  *proto = *cp;
483  if (!(*proto & 1)) {
484    *proto = (*proto << 8) | cp[1];
485    return 2;
486  }
487  return 1;
488}
489
490void
491hdlc_Input(struct bundle *bundle, struct mbuf * bp, struct physical *physical)
492{
493  u_short fcs, proto;
494  u_char *cp, addr, ctrl;
495  int n;
496
497  log_DumpBp(LogHDLC, "hdlc_Input:", bp);
498  if (physical_IsSync(physical))
499    fcs = GOODFCS;
500  else
501    fcs = hdlc_Fcs(INITFCS, MBUF_CTOP(bp), bp->cnt);
502  physical->hdlc.lqm.SaveInOctets += bp->cnt + 1;
503
504  log_Printf(LogDEBUG, "%s: hdlc_Input: fcs = %04x (%s)\n",
505            physical->link.name, fcs, (fcs == GOODFCS) ? "good" : "BAD!");
506  if (fcs != GOODFCS) {
507    physical->hdlc.lqm.SaveInErrors++;
508    physical->hdlc.stats.badfcs++;
509    mbuf_Free(bp);
510    return;
511  }
512  if (!physical_IsSync(physical))
513    bp->cnt -= 2;		/* discard FCS part */
514
515  if (bp->cnt < 2) {		/* XXX: raise this bar ? */
516    mbuf_Free(bp);
517    return;
518  }
519  cp = MBUF_CTOP(bp);
520
521  if (!physical->link.lcp.want_acfcomp) {
522    /* We expect the packet not to be compressed */
523    addr = *cp++;
524    if (addr != HDLC_ADDR) {
525      physical->hdlc.lqm.SaveInErrors++;
526      physical->hdlc.stats.badaddr++;
527      log_Printf(LogDEBUG, "hdlc_Input: addr %02x\n", *cp);
528      mbuf_Free(bp);
529      return;
530    }
531    ctrl = *cp++;
532    if (ctrl != HDLC_UI) {
533      physical->hdlc.lqm.SaveInErrors++;
534      physical->hdlc.stats.badcommand++;
535      log_Printf(LogDEBUG, "hdlc_Input: %02x\n", *cp);
536      mbuf_Free(bp);
537      return;
538    }
539    bp->offset += 2;
540    bp->cnt -= 2;
541  } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
542    /*
543     * We can receive compressed packets, but the peer still sends
544     * uncompressed packets !
545     */
546    cp += 2;
547    bp->offset += 2;
548    bp->cnt -= 2;
549  }
550
551  n = hdlc_GetProto(cp, &proto);
552  bp->offset += n;
553  bp->cnt -= n;
554  if (!physical->link.lcp.want_protocomp && n == 1)
555    log_Printf(LogHDLC, "%s: Warning: received a proto-compressed packet !\n",
556               physical->link.name);
557
558  link_ProtocolRecord(&physical->link, proto, PROTO_IN);
559  physical->hdlc.lqm.SaveInPackets++;
560
561  hdlc_DecodePacket(bundle, proto, bp, &physical->link);
562}
563
564/*
565 *  Detect a HDLC frame
566 */
567
568static const char *FrameHeaders[] = {
569  "\176\377\003\300\041",
570  "\176\377\175\043\300\041",
571  "\176\177\175\043\100\041",
572  "\176\175\337\175\043\300\041",
573  "\176\175\137\175\043\100\041",
574  NULL,
575};
576
577u_char *
578hdlc_Detect(struct physical *physical, u_char *cp, int n)
579{
580  const char *fp, **hp;
581  char *ptr;
582
583  cp[n] = '\0';				/* be sure to null terminate */
584  ptr = NULL;
585  for (hp = FrameHeaders; *hp; hp++) {
586    fp = *hp;
587    if (physical_IsSync(physical))
588      fp++;
589    ptr = strstr((char *)cp, fp);	/* XXX: cp may have embedded NULs */
590    if (ptr)
591      break;
592  }
593  return (u_char *)ptr;
594}
595
596int
597hdlc_ReportStatus(struct cmdargs const *arg)
598{
599  struct hdlc *hdlc = &arg->cx->physical->hdlc;
600
601  prompt_Printf(arg->prompt, "%s HDLC level errors:\n", arg->cx->name);
602  prompt_Printf(arg->prompt, " Bad Frame Check Sequence fields: %u\n",
603	        hdlc->stats.badfcs);
604  prompt_Printf(arg->prompt, " Bad address (!= 0x%02x) fields:    %u\n",
605	        HDLC_ADDR, hdlc->stats.badaddr);
606  prompt_Printf(arg->prompt, " Bad command (!= 0x%02x) fields:    %u\n",
607	        HDLC_UI, hdlc->stats.badcommand);
608  prompt_Printf(arg->prompt, " Unrecognised protocol fields:    %u\n",
609	        hdlc->stats.unknownproto);
610  return 0;
611}
612
613static void
614hdlc_ReportTime(void *v)
615{
616  /* Moan about HDLC errors */
617  struct hdlc *hdlc = (struct hdlc *)v;
618
619  timer_Stop(&hdlc->ReportTimer);
620
621  if (memcmp(&hdlc->laststats, &hdlc->stats, sizeof hdlc->stats)) {
622    log_Printf(LogPHASE,
623              "%s: HDLC errors -> FCS: %u, ADDR: %u, COMD: %u, PROTO: %u\n",
624              hdlc->lqm.owner->fsm.link->name,
625	      hdlc->stats.badfcs - hdlc->laststats.badfcs,
626              hdlc->stats.badaddr - hdlc->laststats.badaddr,
627              hdlc->stats.badcommand - hdlc->laststats.badcommand,
628              hdlc->stats.unknownproto - hdlc->laststats.unknownproto);
629    hdlc->laststats = hdlc->stats;
630  }
631
632  timer_Start(&hdlc->ReportTimer);
633}
634
635void
636hdlc_StartTimer(struct hdlc *hdlc)
637{
638  timer_Stop(&hdlc->ReportTimer);
639  hdlc->ReportTimer.load = 60 * SECTICKS;
640  hdlc->ReportTimer.arg = hdlc;
641  hdlc->ReportTimer.func = hdlc_ReportTime;
642  hdlc->ReportTimer.name = "hdlc";
643  timer_Start(&hdlc->ReportTimer);
644}
645
646void
647hdlc_StopTimer(struct hdlc *hdlc)
648{
649  timer_Stop(&hdlc->ReportTimer);
650}
651