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 #include <sys/cdefs.h> 23 #ifndef lint 24 __RCSID("$NetBSD: print-chdlc.c,v 1.10 2023/08/17 20:19:40 christos Exp $"); 25 #endif 26 27 /* \summary: Cisco HDLC printer */ 28 29 #ifdef HAVE_CONFIG_H 30 #include <config.h> 31 #endif 32 33 #include "netdissect-stdinc.h" 34 35 #include "netdissect.h" 36 #include "addrtoname.h" 37 #include "ethertype.h" 38 #include "extract.h" 39 #include "chdlc.h" 40 #include "nlpid.h" 41 42 static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int); 43 44 static const struct tok chdlc_cast_values[] = { 45 { CHDLC_UNICAST, "unicast" }, 46 { CHDLC_BCAST, "bcast" }, 47 { 0, NULL} 48 }; 49 50 51 /* Standard CHDLC printer */ 52 void 53 chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 54 { 55 ndo->ndo_protocol = "chdlc"; 56 ndo->ndo_ll_hdr_len += chdlc_print(ndo, p, h->len); 57 } 58 59 u_int 60 chdlc_print(netdissect_options *ndo, const u_char *p, u_int length) 61 { 62 u_int proto; 63 const u_char *bp = p; 64 65 ndo->ndo_protocol = "chdlc"; 66 if (length < CHDLC_HDRLEN) 67 goto trunc; 68 proto = GET_BE_U_2(p + 2); 69 if (ndo->ndo_eflag) { 70 ND_PRINT("%s, ethertype %s (0x%04x), length %u: ", 71 tok2str(chdlc_cast_values, "0x%02x", GET_U_1(p)), 72 tok2str(ethertype_values, "Unknown", proto), 73 proto, 74 length); 75 } 76 77 length -= CHDLC_HDRLEN; 78 p += CHDLC_HDRLEN; 79 80 switch (proto) { 81 case ETHERTYPE_IP: 82 ip_print(ndo, p, length); 83 break; 84 case ETHERTYPE_IPV6: 85 ip6_print(ndo, p, length); 86 break; 87 case CHDLC_TYPE_SLARP: 88 chdlc_slarp_print(ndo, p, length); 89 break; 90 case ETHERTYPE_MPLS: 91 case ETHERTYPE_MPLS_MULTI: 92 mpls_print(ndo, p, length); 93 break; 94 case ETHERTYPE_ISO: 95 /* is the fudge byte set ? lets verify by spotting ISO headers */ 96 if (length < 2) 97 goto trunc; 98 if (GET_U_1(p + 1) == NLPID_CLNP || 99 GET_U_1(p + 1) == NLPID_ESIS || 100 GET_U_1(p + 1) == NLPID_ISIS) 101 isoclns_print(ndo, p + 1, length - 1); 102 else 103 isoclns_print(ndo, p, length); 104 break; 105 default: 106 if (!ndo->ndo_eflag) 107 ND_PRINT("unknown CHDLC protocol (0x%04x)", proto); 108 break; 109 } 110 111 return (CHDLC_HDRLEN); 112 113 trunc: 114 nd_print_trunc(ndo); 115 return (ND_BYTES_AVAILABLE_AFTER(bp)); 116 } 117 118 /* 119 * The fixed-length portion of a SLARP packet. 120 */ 121 struct cisco_slarp { 122 nd_uint32_t code; 123 #define SLARP_REQUEST 0 124 #define SLARP_REPLY 1 125 #define SLARP_KEEPALIVE 2 126 union { 127 struct { 128 uint8_t addr[4]; 129 uint8_t mask[4]; 130 } addr; 131 struct { 132 nd_uint32_t myseq; 133 nd_uint32_t yourseq; 134 nd_uint16_t rel; 135 } keep; 136 } un; 137 }; 138 139 #define SLARP_MIN_LEN 14 140 #define SLARP_MAX_LEN 18 141 142 static void 143 chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length) 144 { 145 const struct cisco_slarp *slarp; 146 u_int sec,min,hrs,days; 147 148 ndo->ndo_protocol = "chdlc_slarp"; 149 ND_PRINT("SLARP (length: %u), ",length); 150 if (length < SLARP_MIN_LEN) 151 goto trunc; 152 153 slarp = (const struct cisco_slarp *)cp; 154 ND_TCHECK_LEN(slarp, SLARP_MIN_LEN); 155 switch (GET_BE_U_4(slarp->code)) { 156 case SLARP_REQUEST: 157 ND_PRINT("request"); 158 /* 159 * At least according to William "Chops" Westfield's 160 * message in 161 * 162 * https://web.archive.org/web/20190725151313/www.nethelp.no/net/cisco-hdlc.txt 163 * 164 * the address and mask aren't used in requests - 165 * they're just zero. 166 */ 167 break; 168 case SLARP_REPLY: 169 ND_PRINT("reply %s/%s", 170 GET_IPADDR_STRING(slarp->un.addr.addr), 171 GET_IPADDR_STRING(slarp->un.addr.mask)); 172 break; 173 case SLARP_KEEPALIVE: 174 ND_PRINT("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x", 175 GET_BE_U_4(slarp->un.keep.myseq), 176 GET_BE_U_4(slarp->un.keep.yourseq), 177 GET_BE_U_2(slarp->un.keep.rel)); 178 179 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */ 180 cp += SLARP_MIN_LEN; 181 sec = GET_BE_U_4(cp) / 1000; 182 min = sec / 60; sec -= min * 60; 183 hrs = min / 60; min -= hrs * 60; 184 days = hrs / 24; hrs -= days * 24; 185 ND_PRINT(", link uptime=%ud%uh%um%us",days,hrs,min,sec); 186 } 187 break; 188 default: 189 ND_PRINT("0x%02x unknown", GET_BE_U_4(slarp->code)); 190 if (ndo->ndo_vflag <= 1) 191 print_unknown_data(ndo,cp+4,"\n\t",length-4); 192 break; 193 } 194 195 if (SLARP_MAX_LEN < length && ndo->ndo_vflag) 196 ND_PRINT(", (trailing junk: %u bytes)", length - SLARP_MAX_LEN); 197 if (ndo->ndo_vflag > 1) 198 print_unknown_data(ndo,cp+4,"\n\t",length-4); 199 return; 200 201 trunc: 202 nd_print_trunc(ndo); 203 } 204