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 register u_int length = h->len; 50 register u_int caplen = h->caplen; 51 52 if (caplen < CHDLC_HDRLEN) { 53 ND_PRINT((ndo, "[|chdlc]")); 54 return (caplen); 55 } 56 return (chdlc_print(ndo, p,length)); 57 } 58 59 u_int 60 chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length) 61 { 62 u_int proto; 63 64 proto = EXTRACT_16BITS(&p[2]); 65 if (ndo->ndo_eflag) { 66 ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ", 67 tok2str(chdlc_cast_values, "0x%02x", p[0]), 68 tok2str(ethertype_values, "Unknown", proto), 69 proto, 70 length)); 71 } 72 73 length -= CHDLC_HDRLEN; 74 p += CHDLC_HDRLEN; 75 76 switch (proto) { 77 case ETHERTYPE_IP: 78 ip_print(ndo, p, length); 79 break; 80 case ETHERTYPE_IPV6: 81 ip6_print(ndo, p, length); 82 break; 83 case CHDLC_TYPE_SLARP: 84 chdlc_slarp_print(ndo, p, length); 85 break; 86 #if 0 87 case CHDLC_TYPE_CDP: 88 chdlc_cdp_print(p, length); 89 break; 90 #endif 91 case ETHERTYPE_MPLS: 92 case ETHERTYPE_MPLS_MULTI: 93 mpls_print(ndo, p, length); 94 break; 95 case ETHERTYPE_ISO: 96 /* is the fudge byte set ? lets verify by spotting ISO headers */ 97 if (*(p+1) == 0x81 || 98 *(p+1) == 0x82 || 99 *(p+1) == 0x83) 100 isoclns_print(ndo, p + 1, length - 1, ndo->ndo_snapend - p - 1); 101 else 102 isoclns_print(ndo, p, length, ndo->ndo_snapend - p); 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 } 112 113 /* 114 * The fixed-length portion of a SLARP packet. 115 */ 116 struct cisco_slarp { 117 uint8_t code[4]; 118 #define SLARP_REQUEST 0 119 #define SLARP_REPLY 1 120 #define SLARP_KEEPALIVE 2 121 union { 122 struct { 123 uint8_t addr[4]; 124 uint8_t mask[4]; 125 } addr; 126 struct { 127 uint8_t myseq[4]; 128 uint8_t yourseq[4]; 129 uint8_t rel[2]; 130 } keep; 131 } un; 132 }; 133 134 #define SLARP_MIN_LEN 14 135 #define SLARP_MAX_LEN 18 136 137 static void 138 chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length) 139 { 140 const struct cisco_slarp *slarp; 141 u_int sec,min,hrs,days; 142 143 ND_PRINT((ndo, "SLARP (length: %u), ",length)); 144 if (length < SLARP_MIN_LEN) 145 goto trunc; 146 147 slarp = (const struct cisco_slarp *)cp; 148 ND_TCHECK2(*slarp, SLARP_MIN_LEN); 149 switch (EXTRACT_32BITS(&slarp->code)) { 150 case SLARP_REQUEST: 151 ND_PRINT((ndo, "request")); 152 /* 153 * At least according to William "Chops" Westfield's 154 * message in 155 * 156 * http://www.nethelp.no/net/cisco-hdlc.txt 157 * 158 * the address and mask aren't used in requests - 159 * they're just zero. 160 */ 161 break; 162 case SLARP_REPLY: 163 ND_PRINT((ndo, "reply %s/%s", 164 ipaddr_string(ndo, &slarp->un.addr.addr), 165 ipaddr_string(ndo, &slarp->un.addr.mask))); 166 break; 167 case SLARP_KEEPALIVE: 168 ND_PRINT((ndo, "keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x", 169 EXTRACT_32BITS(&slarp->un.keep.myseq), 170 EXTRACT_32BITS(&slarp->un.keep.yourseq), 171 EXTRACT_16BITS(&slarp->un.keep.rel))); 172 173 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */ 174 cp += SLARP_MIN_LEN; 175 ND_TCHECK2(*cp, 4); 176 sec = EXTRACT_32BITS(cp) / 1000; 177 min = sec / 60; sec -= min * 60; 178 hrs = min / 60; min -= hrs * 60; 179 days = hrs / 24; hrs -= days * 24; 180 ND_PRINT((ndo, ", link uptime=%ud%uh%um%us",days,hrs,min,sec)); 181 } 182 break; 183 default: 184 ND_PRINT((ndo, "0x%02x unknown", EXTRACT_32BITS(&slarp->code))); 185 if (ndo->ndo_vflag <= 1) 186 print_unknown_data(ndo,cp+4,"\n\t",length-4); 187 break; 188 } 189 190 if (SLARP_MAX_LEN < length && ndo->ndo_vflag) 191 ND_PRINT((ndo, ", (trailing junk: %d bytes)", length - SLARP_MAX_LEN)); 192 if (ndo->ndo_vflag > 1) 193 print_unknown_data(ndo,cp+4,"\n\t",length-4); 194 return; 195 196 trunc: 197 ND_PRINT((ndo, "[|slarp]")); 198 } 199 200 201 /* 202 * Local Variables: 203 * c-style: whitesmith 204 * c-basic-offset: 8 205 * End: 206 */ 207