The Tcpdump Group git mirrors - tcpdump/blob - print-ether.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   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 #ifndef lint
  22 static const char rcsid[] _U_ =
  23     "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.90 2004-03-30 14:42:40 mcr Exp $ (LBL)";
  24 #endif
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <tcpdump-stdinc.h>
  31
  32 #include <stdio.h>
  33 #include <pcap.h>
  34
  35 #include "interface.h"
  36 #include "addrtoname.h"
  37 #include "ethertype.h"
  38
  39 #include "ether.h"
  40
  41 const u_char *snapend;
  42
  43 const struct tok ethertype_values[] = {
  44     { ETHERTYPE_IP,             "IPv4" },
  45     { ETHERTYPE_MPLS,           "MPLS unicast" },
  46     { ETHERTYPE_MPLS_MULTI,     "MPLS multicast" },
  47     { ETHERTYPE_IPV6,           "IPv6" },
  48     { ETHERTYPE_8021Q,          "802.1Q" },
  49     { ETHERTYPE_VMAN,           "VMAN" },
  50     { ETHERTYPE_PUP,            "PUP" },
  51     { ETHERTYPE_ARP,            "ARP"},
  52     { ETHERTYPE_REVARP ,        "Reverse ARP"},
  53     { ETHERTYPE_NS,             "NS" },
  54     { ETHERTYPE_SPRITE,         "Sprite" },
  55     { ETHERTYPE_TRAIL,          "Trail" },
  56     { ETHERTYPE_MOPDL,          "MOP DL" },
  57     { ETHERTYPE_MOPRC,          "MOP RC" },
  58     { ETHERTYPE_DN,             "DN" },
  59     { ETHERTYPE_LAT,            "LAT" },
  60     { ETHERTYPE_SCA,            "SCA" },
  61     { ETHERTYPE_LANBRIDGE,      "Lanbridge" },
  62     { ETHERTYPE_DECDNS,         "DEC DNS" },
  63     { ETHERTYPE_DECDTS,         "DEC DTS" },
  64     { ETHERTYPE_VEXP,           "VEXP" },
  65     { ETHERTYPE_VPROD,          "VPROD" },
  66     { ETHERTYPE_ATALK,          "Appletalk" },
  67     { ETHERTYPE_AARP,           "Appletalk ARP" },
  68     { ETHERTYPE_IPX,            "IPX" },
  69     { ETHERTYPE_PPP,            "PPP" },
  70     { ETHERTYPE_PPPOED,         "PPPoE D" },
  71     { ETHERTYPE_PPPOES,         "PPPoE S" },
  72     { ETHERTYPE_EAPOL,          "EAPOL" },
  73     { ETHERTYPE_JUMBO,          "Jumbo" },
  74     { ETHERTYPE_LOOPBACK,       "Loopback" },
  75     { ETHERTYPE_ISO,            "OSI" },
  76     { 0, NULL}
  77 };
  78
  79 static inline void
  80 ether_hdr_print(register const u_char *bp, u_int length)
  81 {
  82         register const struct ether_header *ep;
  83         ep = (const struct ether_header *)bp;
  84
  85         (void)printf("%s > %s",
  86                      etheraddr_string(ESRC(ep)),
  87                      etheraddr_string(EDST(ep)));
  88
  89         if (!qflag) {
  90                 if (ntohs(ep->ether_type) <= ETHERMTU)
  91                           (void)printf(", 802.3");
  92                 else
  93                           (void)printf(", ethertype %s (0x%04x)",
  94                                        tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
  95                                        ntohs(ep->ether_type));
  96         } else {
  97                 if (ntohs(ep->ether_type) <= ETHERMTU)
  98                           (void)printf(", 802.3");
  99                 else
 100                           (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
 101         }
 102
 103         (void)printf(", length %u: ", length);
 104 }
 105
 106 void
 107 ether_print(const u_char *p, u_int length, u_int caplen)
 108 {
 109         struct ether_header *ep;
 110         u_short ether_type;
 111         u_short extracted_ether_type;
 112
 113         if (caplen < ETHER_HDRLEN) {
 114                 printf("[|ether]");
 115                 return;
 116         }
 117
 118         if (eflag)
 119                 ether_hdr_print(p, length);
 120
 121         length -= ETHER_HDRLEN;
 122         caplen -= ETHER_HDRLEN;
 123         ep = (struct ether_header *)p;
 124         p += ETHER_HDRLEN;
 125
 126         ether_type = ntohs(ep->ether_type);
 127
 128         /*
 129          * Is it (gag) an 802.3 encapsulation?
 130          */
 131         extracted_ether_type = 0;
 132         if (ether_type <= ETHERMTU) {
 133                 /* Try to print the LLC-layer header & higher layers */
 134                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
 135                     &extracted_ether_type) == 0) {
 136                         /* ether_type not known, print raw packet */
 137                         if (!eflag)
 138                                 ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 139
 140                         if (!xflag && !qflag)
 141                                 default_print(p, caplen);
 142                 }
 143         } else if (ether_encap_print(ether_type, p, length, caplen,
 144             &extracted_ether_type) == 0) {
 145                 /* ether_type not known, print raw packet */
 146                 if (!eflag)
 147                         ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 148
 149                 if (!xflag && !qflag)
 150                         default_print(p, caplen);
 151         }
 152 }
 153
 154 /*
 155  * This is the top level routine of the printer.  'p' points
 156  * to the ether header of the packet, 'h->ts' is the timestamp,
 157  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 158  * is the number of bytes actually captured.
 159  */
 160 u_int
 161 ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
 162 {
 163         ether_print(p, h->len, h->caplen);
 164
 165         return (ETHER_HDRLEN);
 166 }
 167
 168 /*
 169  * Prints the packet encapsulated in an Ethernet data segment
 170  * (or an equivalent encapsulation), given the Ethernet type code.
 171  *
 172  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 173  *
 174  * The Ethernet type code is passed through a pointer; if it was
 175  * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 176  * the 802.1Q payload, for the benefit of lower layers that might
 177  * want to know what it is.
 178  */
 179
 180 int
 181 ether_encap_print(u_short ether_type, const u_char *p,
 182     u_int length, u_int caplen, u_short *extracted_ether_type)
 183 {
 184  recurse:
 185         *extracted_ether_type = ether_type;
 186
 187         switch (ether_type) {
 188
 189         case ETHERTYPE_IP:
 190                 ip_print(p, length);
 191                 return (1);
 192
 193 #ifdef INET6
 194         case ETHERTYPE_IPV6:
 195                 ip6_print(p, length);
 196                 return (1);
 197 #endif /*INET6*/
 198
 199         case ETHERTYPE_ARP:
 200         case ETHERTYPE_REVARP:
 201                 arp_print(p, length, caplen);
 202                 return (1);
 203
 204         case ETHERTYPE_DN:
 205                 decnet_print(p, length, caplen);
 206                 return (1);
 207
 208         case ETHERTYPE_ATALK:
 209                 if (vflag)
 210                         fputs("et1 ", stdout);
 211                 atalk_print(p, length);
 212                 return (1);
 213
 214         case ETHERTYPE_AARP:
 215                 aarp_print(p, length);
 216                 return (1);
 217
 218         case ETHERTYPE_IPX:
 219                 printf("(NOV-ETHII) ");
 220                 ipx_print(p, length);
 221                 return (1);
 222
 223         case ETHERTYPE_8021Q:
 224                 if (eflag)
 225                     printf("vlan %u, p %u%s, ",
 226                            ntohs(*(u_int16_t *)p) & 0xfff,
 227                            ntohs(*(u_int16_t *)p) >> 13,
 228                            (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
 229
 230                 ether_type = ntohs(*(u_int16_t *)(p + 2));
 231                 p += 4;
 232                 length -= 4;
 233                 caplen -= 4;
 234
 235                 if (ether_type > ETHERMTU) {
 236                         if (eflag)
 237                                 printf("ethertype %s, ",
 238                                        tok2str(ethertype_values,"0x%04x", ether_type));
 239                         goto recurse;
 240                 }
 241
 242                 *extracted_ether_type = 0;
 243
 244                 if (llc_print(p, length, caplen, p - 18, p - 12,
 245                     extracted_ether_type) == 0) {
 246                                 ether_hdr_print(p - 18, length + 4);
 247                 }
 248
 249                 if (!xflag && !qflag)
 250                         default_print(p - 18, caplen + 4);
 251
 252                 return (1);
 253
 254         case ETHERTYPE_JUMBO:
 255                 ether_type = ntohs(*(u_int16_t *)(p));
 256                 p += 2;
 257                 length -= 2;
 258                 caplen -= 2;
 259
 260                 if (ether_type > ETHERMTU) {
 261                     if (eflag)
 262                         printf("ethertype %s, ",
 263                                tok2str(ethertype_values,"0x%04x", ether_type));
 264                     goto recurse;
 265                 }
 266
 267                 *extracted_ether_type = 0;
 268
 269                 if (llc_print(p, length, caplen, p - 16, p - 10,
 270                               extracted_ether_type) == 0) {
 271                     ether_hdr_print(p - 16, length + 2);
 272                 }
 273
 274                 if (!xflag && !qflag)
 275                     default_print(p - 16, caplen + 2);
 276
 277                 return (1);
 278
 279         case ETHERTYPE_ISO:
 280                 isoclns_print(p+1, length-1, length-1);
 281                 return(1);
 282
 283         case ETHERTYPE_PPPOED:
 284         case ETHERTYPE_PPPOES:
 285                 pppoe_print(p, length);
 286                 return (1);
 287
 288         case ETHERTYPE_EAPOL:
 289                 eap_print(gndo, p, length);
 290                 return (1);
 291
 292         case ETHERTYPE_PPP:
 293                 if (length) {
 294                         printf(": ");
 295                         ppp_print(p, length);
 296                 }
 297                 return (1);
 298
 299         case ETHERTYPE_LOOPBACK:
 300                 return (0);
 301
 302         case ETHERTYPE_MPLS:
 303         case ETHERTYPE_MPLS_MULTI:
 304                 mpls_print(p, length);
 305                 return (1);
 306
 307         case ETHERTYPE_LAT:
 308         case ETHERTYPE_SCA:
 309         case ETHERTYPE_MOPRC:
 310         case ETHERTYPE_MOPDL:
 311                 /* default_print for now */
 312         default:
 313                 return (0);
 314         }
 315 }