| File: | src/usr.sbin/tcpdump/print-ether.c |
| Warning: | line 183, column 2 Value stored to 'caplen' is never read |
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| 1 | /* $OpenBSD: print-ether.c,v 1.42 2022/06/09 12:56:14 mbuhl Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1988, 1989, 1990, 1991, 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 | |
| 24 | #include <sys/time.h> |
| 25 | #include <sys/socket.h> |
| 26 | |
| 27 | #include <net/if.h> |
| 28 | |
| 29 | #include <netinet/in.h> |
| 30 | #include <netinet/if_ether.h> |
| 31 | #include <netinet/ip.h> |
| 32 | #include <netinet/ip6.h> |
| 33 | #include <netinet/ip_var.h> |
| 34 | #include <netinet/udp.h> |
| 35 | #include <netinet/udp_var.h> |
| 36 | #include <netinet/tcp.h> |
| 37 | |
| 38 | #include <stdio.h> |
| 39 | #include <stddef.h> |
| 40 | #include <pcap.h> |
| 41 | |
| 42 | |
| 43 | #include "interface.h" |
| 44 | #include "addrtoname.h" |
| 45 | #include "ethertype.h" |
| 46 | #include "extract.h" |
| 47 | |
| 48 | const u_char *packetp; |
| 49 | const u_char *snapend; |
| 50 | |
| 51 | void ether_macctl(const u_char *, u_int); |
| 52 | void ether_pbb_print(const u_char *, u_int, u_int); |
| 53 | void ether_eapol_print(const u_char *, u_int, u_int); |
| 54 | |
| 55 | void |
| 56 | ether_print(const u_char *bp, u_int length) |
| 57 | { |
| 58 | const struct ether_header *ep; |
| 59 | |
| 60 | ep = (const struct ether_header *)bp; |
| 61 | if (qflag) { |
| 62 | TCHECK2(*ep, 12)if (!(snapend - (12) <= snapend && (const u_char * )&(*ep) <= snapend - (12))) goto trunc; |
| 63 | printf("%s %s %d: ", |
| 64 | etheraddr_string(ESRC(ep)((ep)->ether_shost)), |
| 65 | etheraddr_string(EDST(ep)((ep)->ether_dhost)), |
| 66 | length); |
| 67 | } else { |
| 68 | TCHECK2(*ep, 14)if (!(snapend - (14) <= snapend && (const u_char * )&(*ep) <= snapend - (14))) goto trunc; |
| 69 | printf("%s %s %s %d: ", |
| 70 | etheraddr_string(ESRC(ep)((ep)->ether_shost)), |
| 71 | etheraddr_string(EDST(ep)((ep)->ether_dhost)), |
| 72 | etherproto_string(ep->ether_type), |
| 73 | length); |
| 74 | } |
| 75 | return; |
| 76 | trunc: |
| 77 | printf("[|ether] "); |
| 78 | } |
| 79 | |
| 80 | u_short extracted_ethertype; |
| 81 | |
| 82 | /* |
| 83 | * This is the top level routine of the printer. 'p' is the points |
| 84 | * to the ether header of the packet, 'tvp' is the timestamp, |
| 85 | * 'length' is the length of the packet off the wire, and 'caplen' |
| 86 | * is the number of bytes actually captured. |
| 87 | */ |
| 88 | void |
| 89 | ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) |
| 90 | { |
| 91 | ts_print(&h->ts); |
| 92 | |
| 93 | /* |
| 94 | * Some printers want to get back at the ethernet addresses, |
| 95 | * and/or check that they're not walking off the end of the packet. |
| 96 | * Rather than pass them all the way down, we set these globals. |
| 97 | */ |
| 98 | snapend = p + h->caplen; |
| 99 | |
| 100 | ether_tryprint(p, h->len, 1); |
| 101 | } |
| 102 | |
| 103 | void |
| 104 | ether_tryprint(const u_char *p, u_int length, int first_header) |
| 105 | { |
| 106 | struct ether_header *ep; |
| 107 | u_int caplen = snapend - p; |
| 108 | u_short ether_type; |
| 109 | |
| 110 | if (caplen < sizeof(struct ether_header)) { |
| 111 | printf("[|ether]"); |
| 112 | goto out; |
| 113 | } |
| 114 | |
| 115 | if (eflag) |
| 116 | ether_print(p, length); |
| 117 | |
| 118 | packetp = p; |
| 119 | length -= sizeof(struct ether_header); |
| 120 | caplen -= sizeof(struct ether_header); |
| 121 | ep = (struct ether_header *)p; |
| 122 | p += sizeof(struct ether_header); |
| 123 | |
| 124 | ether_type = ntohs(ep->ether_type)(__uint16_t)(__builtin_constant_p(ep->ether_type) ? (__uint16_t )(((__uint16_t)(ep->ether_type) & 0xffU) << 8 | ( (__uint16_t)(ep->ether_type) & 0xff00U) >> 8) : __swap16md (ep->ether_type)); |
| 125 | |
| 126 | /* |
| 127 | * Is it (gag) an 802.3 encapsulation? |
| 128 | */ |
| 129 | extracted_ethertype = 0; |
| 130 | if (ether_type <= ETHERMTU(1518 - ((6 * 2) + 2) - 4)) { |
| 131 | /* Try to print the LLC-layer header & higher layers */ |
| 132 | if (llc_print(p, length, caplen, ESRC(ep)((ep)->ether_shost), EDST(ep)((ep)->ether_dhost)) == 0) { |
| 133 | /* ether_type not known, print raw packet */ |
| 134 | if (!eflag) |
| 135 | ether_print((u_char *)ep, length); |
| 136 | if (extracted_ethertype) { |
| 137 | printf("(LLC %s) ", |
| 138 | etherproto_string(htons(extracted_ethertype)(__uint16_t)(__builtin_constant_p(extracted_ethertype) ? (__uint16_t )(((__uint16_t)(extracted_ethertype) & 0xffU) << 8 | ((__uint16_t)(extracted_ethertype) & 0xff00U) >> 8 ) : __swap16md(extracted_ethertype)))); |
| 139 | } |
| 140 | if (!xflag && !qflag) { |
| 141 | if (eflag) |
| 142 | default_print(packetp, |
| 143 | snapend - packetp); |
| 144 | else |
| 145 | default_print(p, caplen); |
| 146 | } |
| 147 | } |
| 148 | } else if (ether_encap_print(ether_type, p, length, caplen) == 0) { |
| 149 | /* ether_type not known, print raw packet */ |
| 150 | if (!eflag) |
| 151 | ether_print((u_char *)ep, length + sizeof(*ep)); |
| 152 | if (!xflag && !qflag) { |
| 153 | if (eflag) |
| 154 | default_print(packetp, snapend - packetp); |
| 155 | else |
| 156 | default_print(p, caplen); |
| 157 | } |
| 158 | } |
| 159 | if (xflag && first_header) { |
| 160 | if (eflag) |
| 161 | default_print(packetp, snapend - packetp); |
| 162 | else |
| 163 | default_print(p, caplen); |
| 164 | } |
| 165 | out: |
| 166 | if (first_header) |
| 167 | putchar('\n')(!__isthreaded ? __sputc('\n', (&__sF[1])) : (putc)('\n', (&__sF[1]))); |
| 168 | } |
| 169 | |
| 170 | void |
| 171 | ether_pbb_print(const u_char *bp, u_int length, u_int caplen) |
| 172 | { |
| 173 | uint32_t itag; |
| 174 | uint8_t pri, res; |
| 175 | |
| 176 | if (caplen < sizeof(itag)) |
| 177 | goto trunc; |
| 178 | |
| 179 | itag = EXTRACT_32BITS(bp)((u_int32_t)*((const u_int8_t *)(bp) + 0) << 24 | (u_int32_t )*((const u_int8_t *)(bp) + 1) << 16 | (u_int32_t)*((const u_int8_t *)(bp) + 2) << 8 | (u_int32_t)*((const u_int8_t *)(bp) + 3)); |
| 180 | |
| 181 | bp += sizeof(itag); |
| 182 | length -= sizeof(itag); |
| 183 | caplen -= sizeof(itag); |
Value stored to 'caplen' is never read | |
| 184 | |
| 185 | pri = itag >> 29; |
| 186 | if (pri <= 1) |
| 187 | pri = !pri; |
| 188 | |
| 189 | res = (itag >> 24) & 0x7; |
| 190 | |
| 191 | printf("802.1Q ivid %u pri %u ", itag & 0xffffff, pri); |
| 192 | if (itag & (1 << 28)) |
| 193 | printf("dei "); |
| 194 | if (itag & (1 << 27)) |
| 195 | printf("uca "); |
| 196 | if (res) |
| 197 | printf("res %u! ", res); |
| 198 | |
| 199 | ether_tryprint(bp, length, 0); |
| 200 | |
| 201 | return; |
| 202 | |
| 203 | trunc: |
| 204 | printf("[|pbb] "); |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * Prints the packet encapsulated in an Ethernet data segment |
| 209 | * (or an equivalent encapsulation), given the Ethernet type code. |
| 210 | * |
| 211 | * Returns non-zero if it can do so, zero if the ethertype is unknown. |
| 212 | * |
| 213 | * Stuffs the ether type into a global for the benefit of lower layers |
| 214 | * that might want to know what it is. |
| 215 | */ |
| 216 | |
| 217 | int |
| 218 | ether_encap_print(u_short ethertype, const u_char *p, |
| 219 | u_int length, u_int caplen) |
| 220 | { |
| 221 | uint16_t vlan, pri, vid; |
| 222 | recurse: |
| 223 | extracted_ethertype = ethertype; |
| 224 | |
| 225 | switch (ethertype) { |
| 226 | |
| 227 | case ETHERTYPE_IP0x0800: |
| 228 | ip_print(p, length); |
| 229 | return (1); |
| 230 | |
| 231 | case ETHERTYPE_IPV60x86DD: |
| 232 | ip6_print(p, length); |
| 233 | return (1); |
| 234 | |
| 235 | case ETHERTYPE_ARP0x0806: |
| 236 | case ETHERTYPE_REVARP0x8035: |
| 237 | arp_print(p, length, caplen); |
| 238 | return (1); |
| 239 | |
| 240 | case ETHERTYPE_DN0x6003: |
| 241 | decnet_print(p, length, caplen); |
| 242 | return (1); |
| 243 | |
| 244 | case ETHERTYPE_ATALK0x809B: |
| 245 | if (vflag) |
| 246 | printf("et1 "); |
| 247 | atalk_print_llap(p, length); |
| 248 | return (1); |
| 249 | |
| 250 | case ETHERTYPE_AARP0x80F3: |
| 251 | aarp_print(p, length); |
| 252 | return (1); |
| 253 | |
| 254 | case ETHERTYPE_8021Q0x8100: |
| 255 | printf("802.1Q "); |
| 256 | case ETHERTYPE_QINQ0x88A8: |
| 257 | if (ethertype == ETHERTYPE_QINQ0x88A8) |
| 258 | printf("QinQ s"); |
| 259 | |
| 260 | /* XXX caplen check */ |
| 261 | |
| 262 | vlan = ntohs(*(unsigned short*)p)(__uint16_t)(__builtin_constant_p(*(unsigned short*)p) ? (__uint16_t )(((__uint16_t)(*(unsigned short*)p) & 0xffU) << 8 | ((__uint16_t)(*(unsigned short*)p) & 0xff00U) >> 8 ) : __swap16md(*(unsigned short*)p)); |
| 263 | vid = vlan & 0xfff; |
| 264 | pri = vlan >> 13; |
| 265 | if (pri <= 1) |
| 266 | pri = !pri; |
| 267 | |
| 268 | printf("vid %d pri %d%s", vid, pri, |
| 269 | vlan & 0x1000 ? " dei " : " "); |
| 270 | ethertype = ntohs(*(unsigned short*)(p+2))(__uint16_t)(__builtin_constant_p(*(unsigned short*)(p+2)) ? ( __uint16_t)(((__uint16_t)(*(unsigned short*)(p+2)) & 0xffU ) << 8 | ((__uint16_t)(*(unsigned short*)(p+2)) & 0xff00U ) >> 8) : __swap16md(*(unsigned short*)(p+2))); |
| 271 | p += 4; |
| 272 | length -= 4; |
| 273 | caplen -= 4; |
| 274 | if (ethertype > ETHERMTU(1518 - ((6 * 2) + 2) - 4)) |
| 275 | goto recurse; |
| 276 | |
| 277 | extracted_ethertype = 0; |
| 278 | |
| 279 | if (llc_print(p, length, caplen, p-18, p-12) == 0) { |
| 280 | /* ether_type not known, print raw packet */ |
| 281 | if (!eflag) |
| 282 | ether_print(p-18, length+4); |
| 283 | if (extracted_ethertype) { |
| 284 | printf("(LLC %s) ", |
| 285 | etherproto_string(htons(extracted_ethertype)(__uint16_t)(__builtin_constant_p(extracted_ethertype) ? (__uint16_t )(((__uint16_t)(extracted_ethertype) & 0xffU) << 8 | ((__uint16_t)(extracted_ethertype) & 0xff00U) >> 8 ) : __swap16md(extracted_ethertype)))); |
| 286 | } |
| 287 | if (!xflag && !qflag) |
| 288 | default_print(p-18, caplen+4); |
| 289 | } |
| 290 | return (1); |
| 291 | |
| 292 | case ETHERTYPE_NSH0x894F: |
| 293 | nsh_print(p, length); |
| 294 | return (1); |
| 295 | |
| 296 | case ETHERTYPE_EAPOL0x888E: |
| 297 | ether_eapol_print(p, length, caplen); |
| 298 | return (1); |
| 299 | |
| 300 | case ETHERTYPE_PBB0x88e7: |
| 301 | ether_pbb_print(p, length, caplen); |
| 302 | return (1); |
| 303 | |
| 304 | case ETHERTYPE_NHRP0x2001: |
| 305 | nhrp_print(p, length); |
| 306 | return (1); |
| 307 | |
| 308 | #ifdef PPP1 |
| 309 | case ETHERTYPE_PPPOEDISC0x8863: |
| 310 | case ETHERTYPE_PPPOE0x8864: |
| 311 | pppoe_if_print(ethertype, p, length, caplen); |
| 312 | return (1); |
| 313 | #endif |
| 314 | |
| 315 | case ETHERTYPE_FLOWCONTROL0x8808: |
| 316 | ether_macctl(p, length); |
| 317 | return (1); |
| 318 | |
| 319 | case ETHERTYPE_MPLS0x8847: |
| 320 | case ETHERTYPE_MPLS_MCAST0x8848: |
| 321 | mpls_print(p, length); |
| 322 | return (1); |
| 323 | |
| 324 | case ETHERTYPE_LLDP0x88CC: |
| 325 | lldp_print(p, length); |
| 326 | return (1); |
| 327 | |
| 328 | case ETHERTYPE_SLOW0x8809: |
| 329 | slow_print(p, length); |
| 330 | return (1); |
| 331 | |
| 332 | case ETHERTYPE_LAT0x6004: |
| 333 | case ETHERTYPE_SCA0x6007: |
| 334 | case ETHERTYPE_MOPRC0x6002: |
| 335 | case ETHERTYPE_MOPDL0x6001: |
| 336 | /* default_print for now */ |
| 337 | default: |
| 338 | return (0); |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | void |
| 343 | ether_macctl(const u_char *p, u_int length) |
| 344 | { |
| 345 | printf("MACCTL"); |
| 346 | |
| 347 | if (length < 2) |
| 348 | goto trunc; |
| 349 | if (EXTRACT_16BITS(p)((u_int16_t)*((const u_int8_t *)(p) + 0) << 8 | (u_int16_t )*((const u_int8_t *)(p) + 1)) == 0x0001) { |
| 350 | u_int plen; |
| 351 | |
| 352 | printf(" PAUSE"); |
| 353 | |
| 354 | length -= 2; |
| 355 | p += 2; |
| 356 | if (length < 2) |
| 357 | goto trunc; |
| 358 | plen = 512 * EXTRACT_16BITS(p)((u_int16_t)*((const u_int8_t *)(p) + 0) << 8 | (u_int16_t )*((const u_int8_t *)(p) + 1)); |
| 359 | printf(" quanta %u", plen); |
| 360 | } else { |
| 361 | printf(" unknown-opcode(0x%04x)", EXTRACT_16BITS(p)((u_int16_t)*((const u_int8_t *)(p) + 0) << 8 | (u_int16_t )*((const u_int8_t *)(p) + 1))); |
| 362 | } |
| 363 | return; |
| 364 | |
| 365 | trunc: |
| 366 | printf("[|MACCTL]"); |
| 367 | } |
| 368 | |
| 369 | /* |
| 370 | * 802.1X EAPOL PDU |
| 371 | */ |
| 372 | |
| 373 | struct eapol_header { |
| 374 | uint8_t version; |
| 375 | uint8_t type; |
| 376 | #define EAPOL_T_EAP0x00 0x00 |
| 377 | #define EAPOL_T_START0x01 0x01 |
| 378 | #define EAPOL_T_LOGOFF0x02 0x02 |
| 379 | #define EAPOL_T_KEY0x03 0x03 |
| 380 | #define EAPOL_T_ENCAP_ASF_ALERT0x04 0x04 |
| 381 | #define EAPOL_T_MKA0x05 0x05 |
| 382 | #define EAPOL_T_ANNOUNCEMENT_GENERIC0x06 0x06 |
| 383 | #define EAPOL_T_ANNOUNCEMENT_SPECIFIC0x07 0x07 |
| 384 | #define EAPOL_T_ANNOUNCEMENT_REQ0x08 0x08 |
| 385 | uint16_t length; |
| 386 | }; |
| 387 | |
| 388 | void |
| 389 | ether_eapol_print(const u_char *bp, u_int length, u_int caplen) |
| 390 | { |
| 391 | struct eapol_header h; |
| 392 | |
| 393 | printf("EAPOL"); |
| 394 | |
| 395 | if (caplen < sizeof(h)) |
| 396 | goto trunc; |
| 397 | |
| 398 | h.version = *(bp + offsetof(struct eapol_header, version)__builtin_offsetof(struct eapol_header, version)); |
| 399 | h.type = *(bp + offsetof(struct eapol_header, type)__builtin_offsetof(struct eapol_header, type)); |
| 400 | h.length = EXTRACT_16BITS(bp + offsetof(struct eapol_header, length))((u_int16_t)*((const u_int8_t *)(bp + __builtin_offsetof(struct eapol_header, length)) + 0) << 8 | (u_int16_t)*((const u_int8_t *)(bp + __builtin_offsetof(struct eapol_header, length )) + 1)); |
| 401 | |
| 402 | bp += sizeof(h); |
| 403 | length -= sizeof(h); |
| 404 | caplen -= sizeof(h); |
| 405 | |
| 406 | if (vflag) |
| 407 | printf(" (v%u, len %u)", h.version, h.length); |
| 408 | |
| 409 | if (length > h.length) |
| 410 | length = h.length; |
| 411 | else if (length < h.length) { |
| 412 | printf(" truncated-eapol - %u bytes missing!", |
| 413 | h.length - length); |
| 414 | } |
| 415 | |
| 416 | switch (h.type) { |
| 417 | case EAPOL_T_EAP0x00: |
| 418 | printf(" EAP"); |
| 419 | break; |
| 420 | case EAPOL_T_START0x01: |
| 421 | printf(" Start"); |
| 422 | break; |
| 423 | case EAPOL_T_LOGOFF0x02: |
| 424 | printf(" Logoff"); |
| 425 | break; |
| 426 | case EAPOL_T_KEY0x03: |
| 427 | printf(" Key"); |
| 428 | break; |
| 429 | case EAPOL_T_MKA0x05: |
| 430 | printf(" MKA"); |
| 431 | break; |
| 432 | case EAPOL_T_ANNOUNCEMENT_GENERIC0x06: |
| 433 | printf(" Announcement (Generic)"); |
| 434 | break; |
| 435 | case EAPOL_T_ANNOUNCEMENT_SPECIFIC0x07: |
| 436 | printf(" Announcement (Specific)"); |
| 437 | break; |
| 438 | case EAPOL_T_ANNOUNCEMENT_REQ0x08: |
| 439 | printf(" Announcement Req"); |
| 440 | break; |
| 441 | default: |
| 442 | printf(" unknown (%u)", h.type); |
| 443 | break; |
| 444 | } |
| 445 | |
| 446 | return; |
| 447 | |
| 448 | trunc: |
| 449 | printf(" [|eapol] "); |
| 450 | } |