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 1.88 2004-02-18 14:23:27 hannes 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_JUMBO,          "Jumbo" },
  73     { ETHERTYPE_LOOPBACK,       "Loopback" },
  74     { ETHERTYPE_ISO,            "OSI" },
  75     { 0, NULL}
  76 };
  77
  78 static inline void
  79 ether_hdr_print(register const u_char *bp, u_int length)
  80 {
  81         register const struct ether_header *ep;
  82         ep = (const struct ether_header *)bp;
  83
  84         (void)printf("%s > %s",
  85                      etheraddr_string(ESRC(ep)),
  86                      etheraddr_string(EDST(ep)));
  87
  88         if (!qflag) {
  89                 if (ntohs(ep->ether_type) <= ETHERMTU)
  90                           (void)printf(", 802.3");
  91                 else
  92                           (void)printf(", ethertype %s (0x%04x)",
  93                                        tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
  94                                        ntohs(ep->ether_type));
  95         } else {
  96                 if (ntohs(ep->ether_type) <= ETHERMTU)
  97                           (void)printf(", 802.3");
  98                 else
  99                           (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
 100         }
 101
 102         (void)printf(", length %u: ", length);
 103 }
 104
 105 void
 106 ether_print(const u_char *p, u_int length, u_int caplen)
 107 {
 108         struct ether_header *ep;
 109         u_short ether_type;
 110         u_short extracted_ether_type;
 111
 112         if (caplen < ETHER_HDRLEN) {
 113                 printf("[|ether]");
 114                 return;
 115         }
 116
 117         if (eflag)
 118                 ether_hdr_print(p, length);
 119
 120         length -= ETHER_HDRLEN;
 121         caplen -= ETHER_HDRLEN;
 122         ep = (struct ether_header *)p;
 123         p += ETHER_HDRLEN;
 124
 125         ether_type = ntohs(ep->ether_type);
 126
 127         /*
 128          * Is it (gag) an 802.3 encapsulation?
 129          */
 130         extracted_ether_type = 0;
 131         if (ether_type <= ETHERMTU) {
 132                 /* Try to print the LLC-layer header & higher layers */
 133                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
 134                     &extracted_ether_type) == 0) {
 135                         /* ether_type not known, print raw packet */
 136                         if (!eflag)
 137                                 ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 138
 139                         if (!xflag && !qflag)
 140                                 default_print(p, caplen);
 141                 }
 142         } else if (ether_encap_print(ether_type, p, length, caplen,
 143             &extracted_ether_type) == 0) {
 144                 /* ether_type not known, print raw packet */
 145                 if (!eflag)
 146                         ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 147
 148                 if (!xflag && !qflag)
 149                         default_print(p, caplen);
 150         }
 151 }
 152
 153 /*
 154  * This is the top level routine of the printer.  'p' points
 155  * to the ether header of the packet, 'h->ts' is the timestamp,
 156  * 'h->length' is the length of the packet off the wire, and 'h->caplen'
 157  * is the number of bytes actually captured.
 158  */
 159 u_int
 160 ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
 161 {
 162         ether_print(p, h->len, h->caplen);
 163
 164         return (ETHER_HDRLEN);
 165 }
 166
 167 /*
 168  * Prints the packet encapsulated in an Ethernet data segment
 169  * (or an equivalent encapsulation), given the Ethernet type code.
 170  *
 171  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 172  *
 173  * The Ethernet type code is passed through a pointer; if it was
 174  * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 175  * the 802.1Q payload, for the benefit of lower layers that might
 176  * want to know what it is.
 177  */
 178
 179 int
 180 ether_encap_print(u_short ether_type, const u_char *p,
 181     u_int length, u_int caplen, u_short *extracted_ether_type)
 182 {
 183  recurse:
 184         *extracted_ether_type = ether_type;
 185
 186         switch (ether_type) {
 187
 188         case ETHERTYPE_IP:
 189                 ip_print(p, length);
 190                 return (1);
 191
 192 #ifdef INET6
 193         case ETHERTYPE_IPV6:
 194                 ip6_print(p, length);
 195                 return (1);
 196 #endif /*INET6*/
 197
 198         case ETHERTYPE_ARP:
 199         case ETHERTYPE_REVARP:
 200                 arp_print(p, length, caplen);
 201                 return (1);
 202
 203         case ETHERTYPE_DN:
 204                 decnet_print(p, length, caplen);
 205                 return (1);
 206
 207         case ETHERTYPE_ATALK:
 208                 if (vflag)
 209                         fputs("et1 ", stdout);
 210                 atalk_print(p, length);
 211                 return (1);
 212
 213         case ETHERTYPE_AARP:
 214                 aarp_print(p, length);
 215                 return (1);
 216
 217         case ETHERTYPE_IPX:
 218                 printf("(NOV-ETHII) ");
 219                 ipx_print(p, length);
 220                 return (1);
 221
 222         case ETHERTYPE_8021Q:
 223                 if (eflag)
 224                     printf("vlan %u, p %u%s, ",
 225                            ntohs(*(u_int16_t *)p) & 0xfff,
 226                            ntohs(*(u_int16_t *)p) >> 13,
 227                            (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
 228
 229                 ether_type = ntohs(*(u_int16_t *)(p + 2));
 230                 p += 4;
 231                 length -= 4;
 232                 caplen -= 4;
 233
 234                 if (ether_type > ETHERMTU) {
 235                         if (eflag)
 236                                 printf("ethertype %s, ",
 237                                        tok2str(ethertype_values,"0x%04x", ether_type));
 238                         goto recurse;
 239                 }
 240
 241                 *extracted_ether_type = 0;
 242
 243                 if (llc_print(p, length, caplen, p - 18, p - 12,
 244                     extracted_ether_type) == 0) {
 245                                 ether_hdr_print(p - 18, length + 4);
 246                 }
 247
 248                 if (!xflag && !qflag)
 249                         default_print(p - 18, caplen + 4);
 250
 251                 return (1);
 252
 253         case ETHERTYPE_JUMBO:
 254                 ether_type = ntohs(*(u_int16_t *)(p));
 255                 p += 2;
 256                 length -= 2;
 257                 caplen -= 2;
 258
 259                 if (ether_type > ETHERMTU) {
 260                     if (eflag)
 261                         printf("ethertype %s, ",
 262                                tok2str(ethertype_values,"0x%04x", ether_type));
 263                     goto recurse;
 264                 }
 265
 266                 *extracted_ether_type = 0;
 267
 268                 if (llc_print(p, length, caplen, p - 16, p - 10,
 269                               extracted_ether_type) == 0) {
 270                     ether_hdr_print(p - 16, length + 2);
 271                 }
 272
 273                 if (!xflag && !qflag)
 274                     default_print(p - 16, caplen + 2);
 275
 276                 return (1);
 277
 278         case ETHERTYPE_ISO:
 279                 isoclns_print(p+1, length-1, length-1);
 280                 return(1);
 281
 282         case ETHERTYPE_PPPOED:
 283         case ETHERTYPE_PPPOES:
 284                 pppoe_print(p, length);
 285                 return (1);
 286
 287         case ETHERTYPE_PPP:
 288                 if (length) {
 289                         printf(": ");
 290                         ppp_print(p, length);
 291                 }
 292                 return (1);
 293
 294         case ETHERTYPE_LOOPBACK:
 295                 return (0);
 296
 297         case ETHERTYPE_MPLS:
 298         case ETHERTYPE_MPLS_MULTI:
 299                 mpls_print(p, length);
 300                 return (1);
 301
 302         case ETHERTYPE_LAT:
 303         case ETHERTYPE_SCA:
 304         case ETHERTYPE_MOPRC:
 305         case ETHERTYPE_MOPDL:
 306                 /* default_print for now */
 307         default:
 308                 return (0);
 309         }
 310 }