1 /* $OpenBSD: print-llc.c,v 1.13 2001/06/25 19:56:11 itojun Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 * 23 * Code by Matt Thomas, Digital Equipment Corporation 24 * with an awful lot of hacking by Jeffrey Mogul, DECWRL 25 */ 26 27 #ifndef lint 28 static const char rcsid[] = 29 "@(#) $Header: /home/cvs/src/usr.sbin/tcpdump/print-llc.c,v 1.13 2001/06/25 19:56:11 itojun Exp $"; 30 #endif 31 32 #include <sys/param.h> 33 #include <sys/time.h> 34 35 #include <netinet/in.h> 36 37 #include <ctype.h> 38 #include <netdb.h> 39 #include <signal.h> 40 #include <stdio.h> 41 #include <string.h> 42 43 #include "interface.h" 44 #include "addrtoname.h" 45 #include "extract.h" /* must come after interface.h */ 46 #include "ethertype.h" 47 48 #include "llc.h" 49 50 static struct tok cmd2str[] = { 51 { LLC_UI, "ui" }, 52 { LLC_TEST, "test" }, 53 { LLC_XID, "xid" }, 54 { LLC_UA, "ua" }, 55 { LLC_DISC, "disc" }, 56 { LLC_DM, "dm" }, 57 { LLC_SABME, "sabme" }, 58 { LLC_FRMR, "frmr" }, 59 { 0, NULL } 60 }; 61 62 /* 63 * Returns non-zero IFF it succeeds in printing the header 64 */ 65 int 66 llc_print(const u_char *p, u_int length, u_int caplen, 67 const u_char *esrc, const u_char *edst) 68 { 69 struct llc llc; 70 register u_short et; 71 #if 0 72 u_short control; 73 #endif 74 register int ret; 75 76 if (caplen < 3) { 77 (void)printf("[|llc]"); 78 default_print((u_char *)p, caplen); 79 return(0); 80 } 81 82 /* Watch out for possible alignment problems */ 83 memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc))); 84 85 if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) { 86 ipx_print(p, length); 87 return (1); 88 } 89 #ifdef notyet 90 else if (p[0] == 0xf0 && p[1] == 0xf0) 91 netbios_print(p, length); 92 #endif 93 94 /* Cisco Discovery Protocol - SNAP & ether type 0x2000 */ 95 if(llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP && 96 llc.llcui == LLC_UI && 97 llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00 ) { 98 cdp_print( p, length, caplen, esrc, edst); 99 return (1); 100 } 101 102 if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS 103 && llc.llcui == LLC_UI) { 104 isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst); 105 return (1); 106 } 107 108 if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP 109 && llc.llcui == LLC_UI) { 110 if (caplen < sizeof(llc)) { 111 (void)printf("[|llc-snap]"); 112 default_print((u_char *)p, caplen); 113 return (0); 114 } 115 if (vflag) 116 (void)printf("snap %s ", protoid_string(llc.llcpi)); 117 118 caplen -= sizeof(llc); 119 length -= sizeof(llc); 120 p += sizeof(llc); 121 122 /* This is an encapsulated Ethernet packet */ 123 et = EXTRACT_16BITS(&llc.ethertype[0]); 124 125 /* 126 * Some protocols have special handling if they are 802.3 127 * SNAP encapsulated vs vers II encapsulated. Handle 128 * those special protocols here, and hand the rest to 129 * print-ether.c so we don't have to duplicate 130 * all that code here. 131 */ 132 switch (et) { 133 case ETHERTYPE_ATALK: 134 atalk_print(p, length); 135 ret = 1; 136 break; 137 default: 138 ret = ether_encap_print(et, p, length, caplen); 139 break; 140 } 141 142 if (ret) 143 return (ret); 144 } 145 146 if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) { 147 stp_print(p, length); 148 return (1); 149 } 150 151 #if 0 152 if (llc.ssap == 0xf0 && llc.dsap == 0xf0) { 153 /* 154 * we don't actually have a full netbeui parser yet, but the 155 * smb parser can handle many smb-in-netbeui packets, which 156 * is very useful, so we call that 157 */ 158 159 /* 160 * Skip the DSAP and LSAP. 161 */ 162 p += 2; 163 length -= 2; 164 caplen -= 2; 165 166 /* 167 * OK, what type of LLC frame is this? The length 168 * of the control field depends on that - S or I 169 * frames have a two-byte control field, and U frames 170 * have a one-byte control field. 171 */ 172 if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) { 173 control = llc.llcu; 174 p += 1; 175 length -= 1; 176 caplen -= 1; 177 } else { 178 control = llc.llcis; 179 p += 2; 180 length -= 2; 181 caplen -= 2; 182 } 183 184 netbeui_print(control, p, p + min(caplen, length)); 185 return (1); 186 } 187 #endif 188 189 if ((llc.ssap & ~LLC_GSAP) == llc.dsap) { 190 if (eflag) 191 (void)printf("%s ", llcsap_string(llc.dsap)); 192 else 193 (void)printf("%s > %s %s ", 194 etheraddr_string(esrc), 195 etheraddr_string(edst), 196 llcsap_string(llc.dsap)); 197 } else { 198 if (eflag) 199 (void)printf("%s > %s ", 200 llcsap_string(llc.ssap & ~LLC_GSAP), 201 llcsap_string(llc.dsap)); 202 else 203 (void)printf("%s %s > %s %s ", 204 etheraddr_string(esrc), 205 llcsap_string(llc.ssap & ~LLC_GSAP), 206 etheraddr_string(edst), 207 llcsap_string(llc.dsap)); 208 } 209 210 if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) { 211 const char *m; 212 char f; 213 m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu)); 214 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) { 215 case 0: f = 'C'; break; 216 case LLC_GSAP: f = 'R'; break; 217 case LLC_U_POLL: f = 'P'; break; 218 case LLC_GSAP|LLC_U_POLL: f = 'F'; break; 219 default: f = '?'; break; 220 } 221 222 printf("%s/%c", m, f); 223 224 if (caplen < 6) { 225 default_print_unaligned(p, caplen); 226 return (0); 227 } 228 p += 3; 229 length -= 3; 230 caplen -= 3; 231 232 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) { 233 if (*p == LLC_XID_FI) { 234 printf(": %02x %02x", p[1], p[2]); 235 p += 3; 236 length -= 3; 237 caplen -= 3; 238 } 239 } 240 241 #if 0 242 if (!strcmp(m,"ui") && f=='C') { 243 /* 244 * we don't have a proper ipx decoder yet, but there 245 * is a partial one in the smb code 246 */ 247 ipx_netbios_print(p,p+min(caplen,length)); 248 } 249 #endif 250 251 } else { 252 char f; 253 llc.llcis = ntohs(llc.llcis); 254 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) { 255 case 0: f = 'C'; break; 256 case LLC_GSAP: f = 'R'; break; 257 case LLC_U_POLL: f = 'P'; break; 258 case LLC_GSAP|LLC_U_POLL: f = 'F'; break; 259 default: f = '?'; break; 260 } 261 262 if ((llc.llcu & LLC_S_FMT) == LLC_S_FMT) { 263 static char *llc_s[] = { "rr", "rej", "rnr", "03" }; 264 (void)printf("%s (r=%d,%c)", 265 llc_s[LLC_S_CMD(llc.llcis)], 266 LLC_IS_NR(llc.llcis), 267 f); 268 } else { 269 (void)printf("I (s=%d,r=%d,%c)", 270 LLC_I_NS(llc.llcis), 271 LLC_IS_NR(llc.llcis), 272 f); 273 } 274 p += 4; 275 length -= 4; 276 caplen -= 4; 277 } 278 (void)printf(" len=%d", length); 279 return(1); 280 } 281