hdlc.c revision 25630
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 1.13 1997/04/19 11:31:38 ache Exp $ 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(u_short fcs, u_char *cp, int len) 112{ 113 while (len--) 114 fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff]; 115 return(fcs); 116} 117 118void 119HdlcOutput(int pri, u_short proto, struct mbuf *bp) 120{ 121 struct mbuf *mhp, *mfcs; 122 struct protostat *statp; 123 struct lqrdata *lqr; 124 u_char *cp; 125 u_short fcs; 126 127 if ((proto & 0xfff1) == 0x21) { /* Network Layer protocol */ 128 if (CcpFsm.state == ST_OPENED) { 129 Pred1Output(pri, proto, bp); 130 return; 131 } 132 } 133 if (DEV_IS_SYNC) 134 mfcs = NULLBUFF; 135 else 136 mfcs = mballoc(2, MB_HDLCOUT); 137 mhp = mballoc(4, MB_HDLCOUT); 138 mhp->cnt = 0; 139 cp = MBUF_CTOP(mhp); 140 if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) { 141 *cp++ = HDLC_ADDR; 142 *cp++ = HDLC_UI; 143 mhp->cnt += 2; 144 } 145 /* 146 * If possible, compress protocol field. 147 */ 148 if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) { 149 *cp++ = proto; 150 mhp->cnt++; 151 } else { 152 *cp++ = proto >> 8; 153 *cp = proto & 0377; 154 mhp->cnt += 2; 155 } 156 mhp->next = bp; 157 bp->next = mfcs; 158 159 lqr = &MyLqrData; 160 lqr->PeerOutPackets = ifOutPackets++; 161 ifOutOctets += plength(mhp) + 1; 162 lqr->PeerOutOctets = ifOutOctets; 163 164 if (proto == PROTO_LQR) { 165 lqr->MagicNumber = LcpInfo.want_magic; 166 lqr->LastOutLQRs = HisLqrData.PeerOutLQRs; 167 lqr->LastOutPackets = HisLqrData.PeerOutPackets; 168 lqr->LastOutOctets = HisLqrData.PeerOutOctets; 169 lqr->PeerInLQRs = HisLqrSave.SaveInLQRs; 170 lqr->PeerInPackets = HisLqrSave.SaveInPackets; 171 lqr->PeerInDiscards = HisLqrSave.SaveInDiscards; 172 lqr->PeerInErrors = HisLqrSave.SaveInErrors; 173 lqr->PeerInOctets = HisLqrSave.SaveInOctets; 174 lqr->PeerOutLQRs = ++ifOutLQRs; 175 LqrDump("LqrOutput", lqr); 176 LqrChangeOrder(lqr, (struct lqrdata *)(MBUF_CTOP(bp))); 177 } 178 179 if (!DEV_IS_SYNC) { 180 fcs = HdlcFcs(INITFCS, MBUF_CTOP(mhp), mhp->cnt); 181 fcs = HdlcFcs(fcs, MBUF_CTOP(bp), bp->cnt); 182 fcs = ~fcs; 183 cp = MBUF_CTOP(mfcs); 184 *cp++ = fcs & 0377; /* Low byte first!! */ 185 *cp++ = fcs >> 8; 186 } 187 188 LogDumpBp(LOG_HDLC, "HdlcOutput", mhp); 189 for (statp = ProtocolStat; statp->number; statp++) 190 if (statp->number == proto) 191 break; 192 statp->out_count++; 193 if (DEV_IS_SYNC) 194 ModemOutput(pri, mhp); 195 else 196 AsyncOutput(pri, mhp, proto); 197} 198 199void 200DecodePacket(u_short proto, struct mbuf *bp) 201{ 202#ifdef DEBUG 203 logprintf("proto = %04x\n", proto); 204#endif 205 u_char *cp; 206 207 switch (proto) { 208 case PROTO_LCP: 209 LcpInput(bp); 210 break; 211 case PROTO_PAP: 212 PapInput(bp); 213 break; 214 case PROTO_LQR: 215 HisLqrSave.SaveInLQRs++; 216 LqrInput(bp); 217 break; 218 case PROTO_CHAP: 219 ChapInput(bp); 220 break; 221 case PROTO_VJUNCOMP: 222 case PROTO_VJCOMP: 223 bp = VjCompInput(bp, proto); 224 if (bp == NULLBUFF) { 225 break; 226 } 227 /* fall down */ 228 case PROTO_IP: 229 IpInput(bp); 230 break; 231 case PROTO_IPCP: 232 IpcpInput(bp); 233 break; 234 case PROTO_CCP: 235 CcpInput(bp); 236 break; 237 case PROTO_COMPD: 238 Pred1Input(bp); 239 break; 240 default: 241 LogPrintf(LOG_PHASE_BIT, "Unknown protocol 0x%04x\n", proto); 242 bp->offset -= 2; 243 bp->cnt += 2; 244 cp = MBUF_CTOP(bp); 245 LcpSendProtoRej(cp, bp->cnt); 246 HisLqrSave.SaveInDiscards++; 247 HdlcStat.unknownproto++; 248 pfree(bp); 249 break; 250 } 251} 252 253int 254ReportProtStatus() 255{ 256 struct protostat *statp; 257 int cnt; 258 259 statp = ProtocolStat; 260 statp--; 261 cnt = 0; 262 printf(" Protocol in out Protocol in out\n"); 263 do { 264 statp++; 265 printf(" %-9s: %8lu, %8lu", 266 statp->name, statp->in_count, statp->out_count); 267 if (++cnt == 2) { 268 printf("\n"); 269 cnt = 0; 270 } 271 } while (statp->number); 272 if (cnt) 273 printf("\n"); 274 return(1); 275} 276 277int 278ReportHdlcStatus() 279{ 280 struct hdlcstat *hp = &HdlcStat; 281 282 printf("HDLC level errors\n\n"); 283 printf("FCS: %u ADDR: %u COMMAND: %u PROTO: %u\n", 284 hp->badfcs, hp->badaddr, hp->badcommand, hp->unknownproto); 285 return(1); 286} 287 288static struct hdlcstat laststat; 289 290void 291HdlcErrorCheck() 292{ 293 struct hdlcstat *hp = &HdlcStat; 294 struct hdlcstat *op = &laststat; 295 296 if (bcmp(hp, op, sizeof(laststat))) { 297 LogPrintf(LOG_PHASE_BIT, "HDLC errors -> FCS: %u ADDR: %u COMD: %u PROTO: %u\n", 298 hp->badfcs - op->badfcs, hp->badaddr - op->badaddr, 299 hp->badcommand - op->badcommand, hp->unknownproto - op->unknownproto); 300 } 301 laststat = HdlcStat; 302} 303 304void 305HdlcInput(struct mbuf *bp) 306{ 307 u_short fcs, proto; 308 u_char *cp, addr, ctrl; 309 struct protostat *statp; 310 311 LogDumpBp(LOG_HDLC, "HdlcInput:", bp); 312 if (DEV_IS_SYNC) 313 fcs = GOODFCS; 314 else 315 fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt); 316 HisLqrSave.SaveInOctets += bp->cnt + 1; 317 318#ifdef DEBUG 319 logprintf("fcs = %04x (%s)\n", fcs, (fcs == GOODFCS)? "good" : "bad"); 320#endif 321 if (fcs != GOODFCS) { 322 HisLqrSave.SaveInErrors++; 323#ifdef DEBUG 324 logprintf("Bad FCS\n"); 325#endif 326 HdlcStat.badfcs++; 327 pfree(bp); 328 return; 329 } 330 if (!DEV_IS_SYNC) 331 bp->cnt -= 2; /* discard FCS part */ 332 333 if (bp->cnt < 2) { /* XXX: raise this bar ? */ 334 pfree(bp); 335 return; 336 } 337 338 cp = MBUF_CTOP(bp); 339 340 ifInPackets++; 341 ifInOctets += bp->cnt; 342 343 if (!LcpInfo.want_acfcomp) { 344 /* 345 * We expect that packet is not compressed. 346 */ 347 addr = *cp++; 348 if (addr != HDLC_ADDR) { 349 HisLqrSave.SaveInErrors++; 350 HdlcStat.badaddr++; 351#ifdef DEBUG 352 logprintf("addr %02x\n", *cp); 353#endif 354 pfree(bp); 355 return; 356 } 357 358 ctrl = *cp++; 359 if (ctrl != HDLC_UI) { 360 HisLqrSave.SaveInErrors++; 361 HdlcStat.badcommand++; 362#ifdef DEBUG 363 logprintf("command %02x\n", *cp); 364#endif 365 pfree(bp); 366 return; 367 } 368 bp->offset += 2; 369 bp->cnt -= 2; 370 } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) { 371 /* 372 * We can receive compressed packet, but peer still send 373 * uncompressed packet to me. 374 */ 375 cp += 2; 376 bp->offset += 2; 377 bp->cnt -= 2; 378 } 379 380 if (LcpInfo.want_protocomp) { 381 proto = 0; 382 cp--; 383 do { 384 cp++; bp->offset++; bp->cnt--; 385 proto = proto << 8; 386 proto += *cp; 387 } while (!(proto & 1)); 388 } else { 389 proto = *cp++ << 8; 390 proto |= *cp++; 391 bp->offset += 2; 392 bp->cnt -= 2; 393 } 394 395 for (statp = ProtocolStat; statp->number; statp++) 396 if (statp->number == proto) 397 break; 398 statp->in_count++; 399 HisLqrSave.SaveInPackets++; 400 401 DecodePacket(proto, bp); 402} 403