1 /* 2 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 */ 21 22 /* \summary: Cisco HDLC printer */ 23 24 #ifdef HAVE_CONFIG_H 25 #include "config.h" 26 #endif 27 28 #include <netdissect-stdinc.h> 29 30 #include "netdissect.h" 31 #include "addrtoname.h" 32 #include "ethertype.h" 33 #include "extract.h" 34 #include "chdlc.h" 35 36 static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int); 37 38 static const struct tok chdlc_cast_values[] = { 39 { CHDLC_UNICAST, "unicast" }, 40 { CHDLC_BCAST, "bcast" }, 41 { 0, NULL} 42 }; 43 44 45 /* Standard CHDLC printer */ 46 u_int 47 chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p) 48 { 49 return chdlc_print(ndo, p, h->len); 50 } 51 52 u_int 53 chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length) 54 { 55 u_int proto; 56 const u_char *bp = p; 57 58 if (length < CHDLC_HDRLEN) 59 goto trunc; 60 ND_TCHECK2(*p, CHDLC_HDRLEN); 61 proto = EXTRACT_16BITS(&p[2]); 62 if (ndo->ndo_eflag) { 63 ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ", 64 tok2str(chdlc_cast_values, "0x%02x", p[0]), 65 tok2str(ethertype_values, "Unknown", proto), 66 proto, 67 length)); 68 } 69 70 length -= CHDLC_HDRLEN; 71 p += CHDLC_HDRLEN; 72 73 switch (proto) { 74 case ETHERTYPE_IP: 75 ip_print(ndo, p, length); 76 break; 77 case ETHERTYPE_IPV6: 78 ip6_print(ndo, p, length); 79 break; 80 case CHDLC_TYPE_SLARP: 81 chdlc_slarp_print(ndo, p, length); 82 break; 83 #if 0 84 case CHDLC_TYPE_CDP: 85 chdlc_cdp_print(p, length); 86 break; 87 #endif 88 case ETHERTYPE_MPLS: 89 case ETHERTYPE_MPLS_MULTI: 90 mpls_print(ndo, p, length); 91 break; 92 case ETHERTYPE_ISO: 93 /* is the fudge byte set ? lets verify by spotting ISO headers */ 94 if (length < 2) 95 goto trunc; 96 ND_TCHECK_16BITS(p); 97 if (*(p+1) == 0x81 || 98 *(p+1) == 0x82 || 99 *(p+1) == 0x83) 100 isoclns_print(ndo, p + 1, length - 1); 101 else 102 isoclns_print(ndo, p, length); 103 break; 104 default: 105 if (!ndo->ndo_eflag) 106 ND_PRINT((ndo, "unknown CHDLC protocol (0x%04x)", proto)); 107 break; 108 } 109 110 return (CHDLC_HDRLEN); 111 112 trunc: 113 ND_PRINT((ndo, "[|chdlc]")); 114 return ndo->ndo_snapend - bp; 115 } 116 117 /* 118 * The fixed-length portion of a SLARP packet. 119 */ 120 struct cisco_slarp { 121 uint8_t code[4]; 122 #define SLARP_REQUEST 0 123 #define SLARP_REPLY 1 124 #define SLARP_KEEPALIVE 2 125 union { 126 struct { 127 uint8_t addr[4]; 128 uint8_t mask[4]; 129 } addr; 130 struct { 131 uint8_t myseq[4]; 132 uint8_t yourseq[4]; 133 uint8_t rel[2]; 134 } keep; 135 } un; 136 }; 137 138 #define SLARP_MIN_LEN 14 139 #define SLARP_MAX_LEN 18 140 141 static void 142 chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length) 143 { 144 const struct cisco_slarp *slarp; 145 u_int sec,min,hrs,days; 146 147 ND_PRINT((ndo, "SLARP (length: %u), ",length)); 148 if (length < SLARP_MIN_LEN) 149 goto trunc; 150 151 slarp = (const struct cisco_slarp *)cp; 152 ND_TCHECK2(*slarp, SLARP_MIN_LEN); 153 switch (EXTRACT_32BITS(&slarp->code)) { 154 case SLARP_REQUEST: 155 ND_PRINT((ndo, "request")); 156 /* 157 * At least according to William "Chops" Westfield's 158 * message in 159 * 160 * http://www.nethelp.no/net/cisco-hdlc.txt 161 * 162 * the address and mask aren't used in requests - 163 * they're just zero. 164 */ 165 break; 166 case SLARP_REPLY: 167 ND_PRINT((ndo, "reply %s/%s", 168 ipaddr_string(ndo, &slarp->un.addr.addr), 169 ipaddr_string(ndo, &slarp->un.addr.mask))); 170 break; 171 case SLARP_KEEPALIVE: 172 ND_PRINT((ndo, "keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x", 173 EXTRACT_32BITS(&slarp->un.keep.myseq), 174 EXTRACT_32BITS(&slarp->un.keep.yourseq), 175 EXTRACT_16BITS(&slarp->un.keep.rel))); 176 177 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */ 178 cp += SLARP_MIN_LEN; 179 ND_TCHECK2(*cp, 4); 180 sec = EXTRACT_32BITS(cp) / 1000; 181 min = sec / 60; sec -= min * 60; 182 hrs = min / 60; min -= hrs * 60; 183 days = hrs / 24; hrs -= days * 24; 184 ND_PRINT((ndo, ", link uptime=%ud%uh%um%us",days,hrs,min,sec)); 185 } 186 break; 187 default: 188 ND_PRINT((ndo, "0x%02x unknown", EXTRACT_32BITS(&slarp->code))); 189 if (ndo->ndo_vflag <= 1) 190 print_unknown_data(ndo,cp+4,"\n\t",length-4); 191 break; 192 } 193 194 if (SLARP_MAX_LEN < length && ndo->ndo_vflag) 195 ND_PRINT((ndo, ", (trailing junk: %d bytes)", length - SLARP_MAX_LEN)); 196 if (ndo->ndo_vflag > 1) 197 print_unknown_data(ndo,cp+4,"\n\t",length-4); 198 return; 199 200 trunc: 201 ND_PRINT((ndo, "[|slarp]")); 202 } 203 204 205 /* 206 * Local Variables: 207 * c-style: whitesmith 208 * c-basic-offset: 8 209 * End: 210 */ 211
