| File: | src/usr.sbin/tcpdump/print-llc.c |
| Warning: | line 275, column 3 Value stored to 'p' is never read |
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| 1 | /* $OpenBSD: print-llc.c,v 1.23 2023/02/28 10:04:50 claudio 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 | #include <sys/time.h> |
| 28 | |
| 29 | #include <netinet/in.h> |
| 30 | |
| 31 | #include <ctype.h> |
| 32 | #include <netdb.h> |
| 33 | #include <signal.h> |
| 34 | #include <stdio.h> |
| 35 | #include <string.h> |
| 36 | |
| 37 | #include "interface.h" |
| 38 | #include "addrtoname.h" |
| 39 | #include "extract.h" /* must come after interface.h */ |
| 40 | #include "ethertype.h" |
| 41 | |
| 42 | #include "llc.h" |
| 43 | |
| 44 | static struct tok cmd2str[] = { |
| 45 | { LLC_UI0x03, "ui" }, |
| 46 | { LLC_TEST0xe3, "test" }, |
| 47 | { LLC_XID0xaf, "xid" }, |
| 48 | { LLC_UA0x63, "ua" }, |
| 49 | { LLC_DISC0x43, "disc" }, |
| 50 | { LLC_DM0x0f, "dm" }, |
| 51 | { LLC_SABME0x6f, "sabme" }, |
| 52 | { LLC_FRMR0x87, "frmr" }, |
| 53 | { 0, NULL((void *)0) } |
| 54 | }; |
| 55 | |
| 56 | /* |
| 57 | * Returns non-zero IFF it succeeds in printing the header |
| 58 | */ |
| 59 | int |
| 60 | llc_print(const u_char *p, u_int length, u_int caplen, |
| 61 | const u_char *esrc, const u_char *edst) |
| 62 | { |
| 63 | struct llc llc; |
| 64 | u_short et; |
| 65 | #if 0 |
| 66 | u_short control; |
| 67 | #endif |
| 68 | int ret; |
| 69 | |
| 70 | if (caplen < 3) { |
| 71 | printf("[|llc]"); |
| 72 | default_print((u_char *)p, caplen); |
| 73 | return(0); |
| 74 | } |
| 75 | |
| 76 | /* Watch out for possible alignment problems */ |
| 77 | memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc))((caplen)>(sizeof(llc))?(sizeof(llc)):(caplen))); |
| 78 | |
| 79 | if (llc.ssap == LLCSAP_GLOBAL0xff && llc.dsap == LLCSAP_GLOBAL0xff) { |
| 80 | ipx_print(p, length); |
| 81 | return (1); |
| 82 | } |
| 83 | #ifdef notyet |
| 84 | else if (p[0] == 0xf0 && p[1] == 0xf0) |
| 85 | netbios_print(p, length); |
| 86 | #endif |
| 87 | if (llc.ssap == LLCSAP_ISONS0xfe && llc.dsap == LLCSAP_ISONS0xfe |
| 88 | && llc.llcuictl.snap.snap_ui == LLC_UI0x03) { |
| 89 | isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst); |
| 90 | return (1); |
| 91 | } |
| 92 | |
| 93 | if (llc.ssap == LLCSAP_SNAP0xaa && llc.dsap == LLCSAP_SNAP0xaa |
| 94 | && llc.llcuictl.snap.snap_ui == LLC_UI0x03) { |
| 95 | if (caplen < sizeof(llc)) { |
| 96 | printf("[|llc-snap]"); |
| 97 | default_print((u_char *)p, caplen); |
| 98 | return (0); |
| 99 | } |
| 100 | |
| 101 | /* Cisco Discovery Protocol - SNAP & ether type 0x2000 */ |
| 102 | if (llc.ethertypectl.snap_ether.snap_ethertype[0] == 0x20 && llc.ethertypectl.snap_ether.snap_ethertype[1] == 0x00) { |
| 103 | cdp_print(p, length, caplen, 8); |
| 104 | return (1); |
| 105 | } |
| 106 | /* Shared Spanning Tree Protocol - SNAP & ether type 0x010b */ |
| 107 | if (llc.ethertypectl.snap_ether.snap_ethertype[0] == 0x01 && llc.ethertypectl.snap_ether.snap_ethertype[1] == 0x0b) { |
| 108 | stp_print(p, length); |
| 109 | return (1); |
| 110 | } |
| 111 | |
| 112 | if (vflag) |
| 113 | printf("snap %s ", protoid_string(llc.llcpictl.snap.snap_pi)); |
| 114 | |
| 115 | caplen -= sizeof(llc); |
| 116 | length -= sizeof(llc); |
| 117 | p += sizeof(llc); |
| 118 | |
| 119 | /* This is an encapsulated Ethernet packet */ |
| 120 | et = EXTRACT_16BITS(&llc.ethertype[0])((u_int16_t)*((const u_int8_t *)(&llc.ctl.snap_ether.snap_ethertype [0]) + 0) << 8 | (u_int16_t)*((const u_int8_t *)(&llc .ctl.snap_ether.snap_ethertype[0]) + 1)); |
| 121 | |
| 122 | /* |
| 123 | * Some protocols have special handling if they are 802.3 |
| 124 | * SNAP encapsulated vs vers II encapsulated. Handle |
| 125 | * those special protocols here, and hand the rest to |
| 126 | * print-ether.c so we don't have to duplicate |
| 127 | * all that code here. |
| 128 | */ |
| 129 | switch (et) { |
| 130 | case ETHERTYPE_ATALK0x809b: |
| 131 | atalk_print(p, length); |
| 132 | ret = 1; |
| 133 | break; |
| 134 | default: |
| 135 | ret = ether_encap_print(et, p, length, caplen); |
| 136 | break; |
| 137 | } |
| 138 | |
| 139 | if (ret) |
| 140 | return (ret); |
| 141 | } |
| 142 | |
| 143 | if (llc.ssap == LLCSAP_8021D0x42 && llc.dsap == LLCSAP_8021D0x42) { |
| 144 | stp_print(p, length); |
| 145 | return (1); |
| 146 | } |
| 147 | |
| 148 | #if 0 |
| 149 | if (llc.ssap == 0xf0 && llc.dsap == 0xf0) { |
| 150 | /* |
| 151 | * we don't actually have a full netbeui parser yet, but the |
| 152 | * smb parser can handle many smb-in-netbeui packets, which |
| 153 | * is very useful, so we call that |
| 154 | */ |
| 155 | |
| 156 | /* |
| 157 | * Skip the DSAP and LSAP. |
| 158 | */ |
| 159 | p += 2; |
| 160 | length -= 2; |
| 161 | caplen -= 2; |
| 162 | |
| 163 | /* |
| 164 | * OK, what type of LLC frame is this? The length |
| 165 | * of the control field depends on that - S or I |
| 166 | * frames have a two-byte control field, and U frames |
| 167 | * have a one-byte control field. |
| 168 | */ |
| 169 | if ((llc.llcuctl.u_ctl & LLC_U_FMT3) == LLC_U_FMT3) { |
| 170 | control = llc.llcuctl.u_ctl; |
| 171 | p += 1; |
| 172 | length -= 1; |
| 173 | caplen -= 1; |
| 174 | } else { |
| 175 | control = llc.llcisctl.is_ctl; |
| 176 | p += 2; |
| 177 | length -= 2; |
| 178 | caplen -= 2; |
| 179 | } |
| 180 | |
| 181 | netbeui_print(control, p, p + min(caplen, length)((caplen)>(length)?(length):(caplen))); |
| 182 | return (1); |
| 183 | } |
| 184 | #endif |
| 185 | |
| 186 | if ((llc.ssap & ~LLC_GSAP1) == llc.dsap) { |
| 187 | if (eflag) |
| 188 | printf("%s ", llcsap_string(llc.dsap)); |
| 189 | else |
| 190 | printf("%s > %s %s ", |
| 191 | etheraddr_string(esrc), |
| 192 | etheraddr_string(edst), |
| 193 | llcsap_string(llc.dsap)); |
| 194 | } else { |
| 195 | if (eflag) |
| 196 | printf("%s > %s ", |
| 197 | llcsap_string(llc.ssap & ~LLC_GSAP1), |
| 198 | llcsap_string(llc.dsap)); |
| 199 | else |
| 200 | printf("%s %s > %s %s ", |
| 201 | etheraddr_string(esrc), |
| 202 | llcsap_string(llc.ssap & ~LLC_GSAP1), |
| 203 | etheraddr_string(edst), |
| 204 | llcsap_string(llc.dsap)); |
| 205 | } |
| 206 | |
| 207 | if ((llc.llcuctl.u_ctl & LLC_U_FMT3) == LLC_U_FMT3) { |
| 208 | const char *m; |
| 209 | char f; |
| 210 | m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu)((llc.ctl.u_ctl) & 0xef)); |
| 211 | switch ((llc.ssap & LLC_GSAP1) | (llc.llcuctl.u_ctl & LLC_U_POLL0x10)) { |
| 212 | case 0: f = 'C'; break; |
| 213 | case LLC_GSAP1: f = 'R'; break; |
| 214 | case LLC_U_POLL0x10: f = 'P'; break; |
| 215 | case LLC_GSAP1|LLC_U_POLL0x10: f = 'F'; break; |
| 216 | default: f = '?'; break; |
| 217 | } |
| 218 | |
| 219 | printf("%s/%c", m, f); |
| 220 | |
| 221 | if (caplen < 6) { |
| 222 | default_print(p, caplen); |
| 223 | return (0); |
| 224 | } |
| 225 | p += 3; |
| 226 | length -= 3; |
| 227 | caplen -= 3; |
| 228 | |
| 229 | if ((llc.llcuctl.u_ctl & ~LLC_U_POLL0x10) == LLC_XID0xaf) { |
| 230 | if (*p == LLC_XID_FI0x81) { |
| 231 | printf(": %02x %02x", p[1], p[2]); |
| 232 | p += 3; |
| 233 | length -= 3; |
| 234 | caplen -= 3; |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | #if 0 |
| 239 | if (!strcmp(m,"ui") && f=='C') { |
| 240 | /* |
| 241 | * we don't have a proper ipx decoder yet, but there |
| 242 | * is a partial one in the smb code |
| 243 | */ |
| 244 | ipx_netbios_print(p,p+min(caplen,length)((caplen)>(length)?(length):(caplen))); |
| 245 | } |
| 246 | #endif |
| 247 | |
| 248 | } else { |
| 249 | char f; |
| 250 | if (caplen < 4) { |
| 251 | default_print(p, caplen); |
| 252 | return (0); |
| 253 | } |
| 254 | llc.llcisctl.is_ctl = ntohs(llc.llcis)(__uint16_t)(__builtin_constant_p(llc.ctl.is_ctl) ? (__uint16_t )(((__uint16_t)(llc.ctl.is_ctl) & 0xffU) << 8 | ((__uint16_t )(llc.ctl.is_ctl) & 0xff00U) >> 8) : __swap16md(llc .ctl.is_ctl)); |
| 255 | switch ((llc.ssap & LLC_GSAP1) | (llc.llcuctl.u_ctl & LLC_U_POLL0x10)) { |
| 256 | case 0: f = 'C'; break; |
| 257 | case LLC_GSAP1: f = 'R'; break; |
| 258 | case LLC_U_POLL0x10: f = 'P'; break; |
| 259 | case LLC_GSAP1|LLC_U_POLL0x10: f = 'F'; break; |
| 260 | default: f = '?'; break; |
| 261 | } |
| 262 | |
| 263 | if ((llc.llcuctl.u_ctl & LLC_S_FMT1) == LLC_S_FMT1) { |
| 264 | static char *llc_s[] = { "rr", "rej", "rnr", "03" }; |
| 265 | printf("%s (r=%d,%c)", |
| 266 | llc_s[LLC_S_CMD(llc.llcis)(((llc.ctl.is_ctl) >> 10) & 0x03)], |
| 267 | LLC_IS_NR(llc.llcis)(((llc.ctl.is_ctl) >> 1) & 0x7f), |
| 268 | f); |
| 269 | } else { |
| 270 | printf("I (s=%d,r=%d,%c)", |
| 271 | LLC_I_NS(llc.llcis)(((llc.ctl.is_ctl) >> 9) & 0x7f), |
| 272 | LLC_IS_NR(llc.llcis)(((llc.ctl.is_ctl) >> 1) & 0x7f), |
| 273 | f); |
| 274 | } |
| 275 | p += 4; |
Value stored to 'p' is never read | |
| 276 | length -= 4; |
| 277 | caplen -= 4; |
| 278 | } |
| 279 | printf(" len=%d", length); |
| 280 | return(1); |
| 281 | } |