/* * PPP High Level Link Control (HDLC) Module * * Written by Toshiharu OHNO (tony-o@iij.ad.jp) * * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by the Internet Initiative Japan, Inc. The name of the * IIJ may not be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * $Id: hdlc.c,v 1.28.2.11 1998/02/18 19:35:41 brian Exp $ * * TODO: */ #include #include #include #include #include #include "command.h" #include "mbuf.h" #include "log.h" #include "defs.h" #include "timer.h" #include "fsm.h" #include "hdlc.h" #include "lcpproto.h" #include "iplist.h" #include "throughput.h" #include "ipcp.h" #include "ip.h" #include "vjcomp.h" #include "pap.h" #include "chap.h" #include "lcp.h" #include "async.h" #include "lqr.h" #include "loadalias.h" #include "vars.h" #include "modem.h" #include "ccp.h" #include "link.h" #include "descriptor.h" #include "physical.h" #include "prompt.h" #include "chat.h" #include "datalink.h" static u_short const fcstab[256] = { /* 00 */ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, /* 08 */ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, /* 10 */ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, /* 18 */ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, /* 20 */ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, /* 28 */ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, /* 30 */ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, /* 38 */ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, /* 40 */ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, /* 48 */ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, /* 50 */ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, /* 58 */ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, /* 60 */ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, /* 68 */ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, /* 70 */ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, /* 78 */ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, /* 80 */ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, /* 88 */ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, /* 90 */ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, /* 98 */ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, /* a0 */ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, /* a8 */ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, /* b0 */ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, /* b8 */ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, /* c0 */ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, /* c8 */ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, /* d0 */ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, /* d8 */ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, /* e0 */ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, /* e8 */ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, /* f0 */ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, /* f8 */ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 }; void hdlc_Init(struct hdlc *hdlc) { memset(hdlc, '\0', sizeof(struct hdlc)); } /* * HDLC FCS computation. Read RFC 1171 Appendix B and CCITT X.25 section * 2.27 for further details. */ inline u_short HdlcFcs(u_short fcs, u_char * cp, int len) { while (len--) fcs = (fcs >> 8) ^ fcstab[(fcs ^ *cp++) & 0xff]; return (fcs); } static inline u_short HdlcFcsBuf(u_short fcs, struct mbuf *m) { int len; u_char *pos, *end; len = plength(m); pos = MBUF_CTOP(m); end = pos + m->cnt; while (len--) { fcs = (fcs >> 8) ^ fcstab[(fcs ^ *pos++) & 0xff]; if (pos == end && len) { m = m->next; pos = MBUF_CTOP(m); end = pos + m->cnt; } } return (fcs); } void HdlcOutput(struct link *l, int pri, u_short proto, struct mbuf *bp) { struct physical *p = link2physical(l); struct mbuf *mhp, *mfcs; struct lqrdata *lqr; u_char *cp; u_short fcs; if ((proto & 0xfff1) == 0x21) /* Network Layer protocol */ if (CcpInfo.fsm.state == ST_OPENED) if (CcpOutput(l, pri, proto, bp)) return; if (!p) { /* * This is where we multiplex the data over our available physical * links. We don't frame our logical link data. Instead we wait * for the logical link implementation to chop our data up and pile * it into the physical links by re-calling this function with the * encapsulated fragments. */ link_Output(l, pri, bp); return; } if (Physical_IsSync(p)) mfcs = NULL; else mfcs = mballoc(2, MB_HDLCOUT); mhp = mballoc(4, MB_HDLCOUT); mhp->cnt = 0; cp = MBUF_CTOP(mhp); if (proto == PROTO_LCP || LcpInfo.his_acfcomp == 0) { *cp++ = HDLC_ADDR; *cp++ = HDLC_UI; mhp->cnt += 2; } /* * If possible, compress protocol field. */ if (LcpInfo.his_protocomp && (proto & 0xff00) == 0) { *cp++ = proto; mhp->cnt++; } else { *cp++ = proto >> 8; *cp = proto & 0377; mhp->cnt += 2; } mhp->next = bp; while (bp->next != NULL) bp = bp->next; bp->next = mfcs; bp = mhp->next; lqr = &MyLqrData; lqr->PeerOutPackets = p->hdlc.lqr.OutPackets++; p->hdlc.lqr.OutOctets += plength(mhp) + 1; lqr->PeerOutOctets = p->hdlc.lqr.OutOctets; if (proto == PROTO_LQR) { lqr->MagicNumber = LcpInfo.want_magic; lqr->LastOutLQRs = HisLqrData.PeerOutLQRs; lqr->LastOutPackets = HisLqrData.PeerOutPackets; lqr->LastOutOctets = HisLqrData.PeerOutOctets; lqr->PeerInLQRs = HisLqrSave.SaveInLQRs; lqr->PeerInPackets = HisLqrSave.SaveInPackets; lqr->PeerInDiscards = HisLqrSave.SaveInDiscards; lqr->PeerInErrors = HisLqrSave.SaveInErrors; lqr->PeerInOctets = HisLqrSave.SaveInOctets; lqr->PeerOutLQRs = ++p->hdlc.lqr.OutLQRs; LqrDump("LqrOutput", lqr); LqrChangeOrder(lqr, (struct lqrdata *) (MBUF_CTOP(bp))); } if (mfcs) { mfcs->cnt = 0; fcs = HdlcFcsBuf(INITFCS, mhp); fcs = ~fcs; cp = MBUF_CTOP(mfcs); *cp++ = fcs & 0377; /* Low byte first!! */ *cp++ = fcs >> 8; mfcs->cnt = 2; } LogDumpBp(LogHDLC, "HdlcOutput", mhp); link_ProtocolRecord(l, proto, PROTO_OUT); LogPrintf(LogDEBUG, "HdlcOutput: proto = 0x%04x\n", proto); if (Physical_IsSync(p)) link_Output(l, pri, mhp); /* Send it raw */ else async_Output(pri, mhp, proto, p); } /* Check out the latest ``Assigned numbers'' rfc (rfc1700.txt) */ static struct { u_short from; u_short to; const char *name; } protocols[] = { { 0x0001, 0x0001, "Padding Protocol" }, { 0x0003, 0x001f, "reserved (transparency inefficient)" }, { 0x0021, 0x0021, "Internet Protocol" }, { 0x0023, 0x0023, "OSI Network Layer" }, { 0x0025, 0x0025, "Xerox NS IDP" }, { 0x0027, 0x0027, "DECnet Phase IV" }, { 0x0029, 0x0029, "Appletalk" }, { 0x002b, 0x002b, "Novell IPX" }, { 0x002d, 0x002d, "Van Jacobson Compressed TCP/IP" }, { 0x002f, 0x002f, "Van Jacobson Uncompressed TCP/IP" }, { 0x0031, 0x0031, "Bridging PDU" }, { 0x0033, 0x0033, "Stream Protocol (ST-II)" }, { 0x0035, 0x0035, "Banyan Vines" }, { 0x0037, 0x0037, "reserved (until 1993)" }, { 0x0039, 0x0039, "AppleTalk EDDP" }, { 0x003b, 0x003b, "AppleTalk SmartBuffered" }, { 0x003d, 0x003d, "Multi-Link" }, { 0x003f, 0x003f, "NETBIOS Framing" }, { 0x0041, 0x0041, "Cisco Systems" }, { 0x0043, 0x0043, "Ascom Timeplex" }, { 0x0045, 0x0045, "Fujitsu Link Backup and Load Balancing (LBLB)" }, { 0x0047, 0x0047, "DCA Remote Lan" }, { 0x0049, 0x0049, "Serial Data Transport Protocol (PPP-SDTP)" }, { 0x004b, 0x004b, "SNA over 802.2" }, { 0x004d, 0x004d, "SNA" }, { 0x004f, 0x004f, "IP6 Header Compression" }, { 0x0051, 0x0051, "KNX Bridging Data" }, { 0x0053, 0x0053, "Encryption" }, { 0x0055, 0x0055, "Individual Link Encryption" }, { 0x006f, 0x006f, "Stampede Bridging" }, { 0x0071, 0x0071, "BAP Bandwidth Allocation Protocol" }, { 0x0073, 0x0073, "MP+ Protocol" }, { 0x007d, 0x007d, "reserved (Control Escape)" }, { 0x007f, 0x007f, "reserved (compression inefficient)" }, { 0x00cf, 0x00cf, "reserved (PPP NLPID)" }, { 0x00fb, 0x00fb, "compression on single link in multilink group" }, { 0x00fd, 0x00fd, "1st choice compression" }, { 0x00ff, 0x00ff, "reserved (compression inefficient)" }, { 0x0200, 0x02ff, "(compression inefficient)" }, { 0x0201, 0x0201, "802.1d Hello Packets" }, { 0x0203, 0x0203, "IBM Source Routing BPDU" }, { 0x0205, 0x0205, "DEC LANBridge100 Spanning Tree" }, { 0x0207, 0x0207, "Cisco Discovery Protocol" }, { 0x0209, 0x0209, "Netcs Twin Routing" }, { 0x0231, 0x0231, "Luxcom" }, { 0x0233, 0x0233, "Sigma Network Systems" }, { 0x0235, 0x0235, "Apple Client Server Protocol" }, { 0x1e00, 0x1eff, "(compression inefficient)" }, { 0x4001, 0x4001, "Cray Communications Control Protocol" }, { 0x4003, 0x4003, "CDPD Mobile Network Registration Protocol" }, { 0x4021, 0x4021, "Stacker LZS" }, { 0x8001, 0x801f, "Not Used - reserved" }, { 0x8021, 0x8021, "Internet Protocol Control Protocol" }, { 0x8023, 0x8023, "OSI Network Layer Control Protocol" }, { 0x8025, 0x8025, "Xerox NS IDP Control Protocol" }, { 0x8027, 0x8027, "DECnet Phase IV Control Protocol" }, { 0x8029, 0x8029, "Appletalk Control Protocol" }, { 0x802b, 0x802b, "Novell IPX Control Protocol" }, { 0x802d, 0x802d, "reserved" }, { 0x802f, 0x802f, "reserved" }, { 0x8031, 0x8031, "Bridging NCP" }, { 0x8033, 0x8033, "Stream Protocol Control Protocol" }, { 0x8035, 0x8035, "Banyan Vines Control Protocol" }, { 0x8037, 0x8037, "reserved till 1993" }, { 0x8039, 0x8039, "reserved" }, { 0x803b, 0x803b, "reserved" }, { 0x803d, 0x803d, "Multi-Link Control Protocol" }, { 0x803f, 0x803f, "NETBIOS Framing Control Protocol" }, { 0x8041, 0x8041, "Cisco Systems Control Protocol" }, { 0x8043, 0x8043, "Ascom Timeplex" }, { 0x8045, 0x8045, "Fujitsu LBLB Control Protocol" }, { 0x8047, 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" }, { 0x8049, 0x8049, "Serial Data Control Protocol (PPP-SDCP)" }, { 0x804b, 0x804b, "SNA over 802.2 Control Protocol" }, { 0x804d, 0x804d, "SNA Control Protocol" }, { 0x804f, 0x804f, "IP6 Header Compression Control Protocol" }, { 0x8051, 0x8051, "KNX Bridging Control Protocol" }, { 0x8053, 0x8053, "Encryption Control Protocol" }, { 0x8055, 0x8055, "Individual Link Encryption Control Protocol" }, { 0x806f, 0x806f, "Stampede Bridging Control Protocol" }, { 0x8073, 0x8073, "MP+ Control Protocol" }, { 0x8071, 0x8071, "BACP Bandwidth Allocation Control Protocol" }, { 0x807d, 0x807d, "Not Used - reserved" }, { 0x80cf, 0x80cf, "Not Used - reserved" }, { 0x80fb, 0x80fb, "compression on single link in multilink group control" }, { 0x80fd, 0x80fd, "Compression Control Protocol" }, { 0x80ff, 0x80ff, "Not Used - reserved" }, { 0x8207, 0x8207, "Cisco Discovery Protocol Control" }, { 0x8209, 0x8209, "Netcs Twin Routing" }, { 0x8235, 0x8235, "Apple Client Server Protocol Control" }, { 0xc021, 0xc021, "Link Control Protocol" }, { 0xc023, 0xc023, "Password Authentication Protocol" }, { 0xc025, 0xc025, "Link Quality Report" }, { 0xc027, 0xc027, "Shiva Password Authentication Protocol" }, { 0xc029, 0xc029, "CallBack Control Protocol (CBCP)" }, { 0xc081, 0xc081, "Container Control Protocol" }, { 0xc223, 0xc223, "Challenge Handshake Authentication Protocol" }, { 0xc225, 0xc225, "RSA Authentication Protocol" }, { 0xc227, 0xc227, "Extensible Authentication Protocol" }, { 0xc26f, 0xc26f, "Stampede Bridging Authorization Protocol" }, { 0xc281, 0xc281, "Proprietary Authentication Protocol" }, { 0xc283, 0xc283, "Proprietary Authentication Protocol" }, { 0xc481, 0xc481, "Proprietary Node ID Authentication Protocol" } }; #define NPROTOCOLS (sizeof protocols/sizeof protocols[0]) const char * hdlc_Protocol2Nam(u_short proto) { int f; for (f = 0; f < NPROTOCOLS; f++) if (proto >= protocols[f].from && proto <= protocols[f].to) return protocols[f].name; else if (proto < protocols[f].from) break; return "unrecognised protocol"; } static void DecodePacket(struct bundle *bundle, u_short proto, struct mbuf * bp, struct link *l) { struct physical *p = link2physical(l); u_char *cp; LogPrintf(LogDEBUG, "DecodePacket: proto = 0x%04x\n", proto); /* decompress everything. CCP needs uncompressed data too */ if ((bp = ccp_Decompress(&proto, bp)) == NULL) return; switch (proto) { case PROTO_LCP: LcpInput(bp); break; case PROTO_PAP: if (p) PapInput(bundle, bp, p); else { LogPrintf(LogERROR, "DecodePacket: PAP: Not a physical link !\n"); pfree(bp); } break; case PROTO_LQR: HisLqrSave.SaveInLQRs++; if (p) LqrInput(p, bp); else { LogPrintf(LogERROR, "DecodePacket: LQR: Not a physical link !\n"); pfree(bp); } break; case PROTO_CHAP: if (p) ChapInput(bundle, bp, p); else { LogPrintf(LogERROR, "DecodePacket: CHAP: Not a physical link !\n"); pfree(bp); } break; case PROTO_VJUNCOMP: case PROTO_VJCOMP: bp = VjCompInput(bp, proto); if (bp == NULL) break; /* fall down */ case PROTO_IP: IpInput(bundle, bp); break; case PROTO_IPCP: IpcpInput(bp); break; case PROTO_CCP: CcpInput(bundle, bp); break; default: LogPrintf(LogPHASE, "Unknown protocol 0x%04x (%s)\n", proto, hdlc_Protocol2Nam(proto)); bp->offset -= 2; bp->cnt += 2; cp = MBUF_CTOP(bp); LcpSendProtoRej(cp, bp->cnt); HisLqrSave.SaveInDiscards++; p->hdlc.stats.unknownproto++; pfree(bp); break; } } void HdlcInput(struct bundle *bundle, struct mbuf * bp, struct physical *physical) { u_short fcs, proto; u_char *cp, addr, ctrl; LogDumpBp(LogHDLC, "HdlcInput:", bp); if (Physical_IsSync(physical)) fcs = GOODFCS; else fcs = HdlcFcs(INITFCS, MBUF_CTOP(bp), bp->cnt); HisLqrSave.SaveInOctets += bp->cnt + 1; LogPrintf(LogDEBUG, "HdlcInput: fcs = %04x (%s)\n", fcs, (fcs == GOODFCS) ? "good" : "bad"); if (fcs != GOODFCS) { HisLqrSave.SaveInErrors++; LogPrintf(LogDEBUG, "HdlcInput: Bad FCS\n"); physical->hdlc.stats.badfcs++; pfree(bp); return; } if (!Physical_IsSync(physical)) bp->cnt -= 2; /* discard FCS part */ if (bp->cnt < 2) { /* XXX: raise this bar ? */ pfree(bp); return; } cp = MBUF_CTOP(bp); if (!LcpInfo.want_acfcomp) { /* * We expect that packet is not compressed. */ addr = *cp++; if (addr != HDLC_ADDR) { HisLqrSave.SaveInErrors++; physical->hdlc.stats.badaddr++; LogPrintf(LogDEBUG, "HdlcInput: addr %02x\n", *cp); pfree(bp); return; } ctrl = *cp++; if (ctrl != HDLC_UI) { HisLqrSave.SaveInErrors++; physical->hdlc.stats.badcommand++; LogPrintf(LogDEBUG, "HdlcInput: %02x\n", *cp); pfree(bp); return; } bp->offset += 2; bp->cnt -= 2; } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) { /* * We can receive compressed packet, but peer still send uncompressed * packet to me. */ cp += 2; bp->offset += 2; bp->cnt -= 2; } if (LcpInfo.want_protocomp) { proto = 0; cp--; do { cp++; bp->offset++; bp->cnt--; proto = proto << 8; proto += *cp; } while (!(proto & 1)); } else { proto = *cp++ << 8; proto |= *cp++; bp->offset += 2; bp->cnt -= 2; } link_ProtocolRecord(physical2link(physical), proto, PROTO_IN); HisLqrSave.SaveInPackets++; DecodePacket(bundle, proto, bp, physical2link(physical)); } /* * Detect a HDLC frame */ static const char *FrameHeaders[] = { "\176\377\003\300\041", "\176\377\175\043\300\041", "\176\177\175\043\100\041", "\176\175\337\175\043\300\041", "\176\175\137\175\043\100\041", NULL, }; u_char * HdlcDetect(struct physical *physical, u_char *cp, int n) { const char *ptr, *fp, **hp; cp[n] = '\0'; /* be sure to null terminated */ ptr = NULL; for (hp = FrameHeaders; *hp; hp++) { fp = *hp; if (Physical_IsSync(physical)) fp++; ptr = strstr((char *) cp, fp); if (ptr) break; } return (u_char *)ptr; } int hdlc_ReportStatus(struct cmdargs const *arg) { prompt_Printf(&prompt, "HDLC level errors:\n"); prompt_Printf(&prompt, " Bad Frame Check Sequence fields: %u\n", arg->cx->physical->hdlc.stats.badfcs); prompt_Printf(&prompt, " Bad address (!= 0x%02x) fields: %u\n", HDLC_ADDR, arg->cx->physical->hdlc.stats.badaddr); prompt_Printf(&prompt, " Bad command (!= 0x%02x) fields: %u\n", HDLC_UI, arg->cx->physical->hdlc.stats.badcommand); prompt_Printf(&prompt, " Unrecognised protocol fields: %u\n", arg->cx->physical->hdlc.stats.unknownproto); return 0; } static void hdlc_ReportTime(void *v) { /* Moan about HDLC errors */ struct hdlc *hdlc = (struct hdlc *)v; StopTimer(&hdlc->ReportTimer); hdlc->ReportTimer.state = TIMER_STOPPED; if (memcmp(&hdlc->laststats, &hdlc->stats, sizeof hdlc->stats)) { LogPrintf(LogPHASE, "HDLC errors -> FCS: %u, ADDR: %u, COMD: %u, PROTO: %u\n", hdlc->stats.badfcs - hdlc->laststats.badfcs, hdlc->stats.badaddr - hdlc->laststats.badaddr, hdlc->stats.badcommand - hdlc->laststats.badcommand, hdlc->stats.unknownproto - hdlc->laststats.unknownproto); hdlc->laststats = hdlc->stats; } StartTimer(&hdlc->ReportTimer); } void hdlc_StartTimer(struct hdlc *hdlc) { StopTimer(&hdlc->ReportTimer); hdlc->ReportTimer.state = TIMER_STOPPED; hdlc->ReportTimer.load = 60 * SECTICKS; hdlc->ReportTimer.arg = hdlc; hdlc->ReportTimer.func = hdlc_ReportTime; StartTimer(&hdlc->ReportTimer); } void hdlc_StopTimer(struct hdlc *hdlc) { StopTimer(&hdlc->ReportTimer); }