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 1.92 2004-04-30 16:42:15 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 struct tok ethertype_values[] = {
  42     { ETHERTYPE_IP,             "IPv4" },
  43     { ETHERTYPE_MPLS,           "MPLS unicast" },
  44     { ETHERTYPE_MPLS_MULTI,     "MPLS multicast" },
  45     { ETHERTYPE_IPV6,           "IPv6" },
  46     { ETHERTYPE_8021Q,          "802.1Q" },
  47     { ETHERTYPE_VMAN,           "VMAN" },
  48     { ETHERTYPE_PUP,            "PUP" },
  49     { ETHERTYPE_ARP,            "ARP"},
  50     { ETHERTYPE_REVARP ,        "Reverse ARP"},
  51     { ETHERTYPE_NS,             "NS" },
  52     { ETHERTYPE_SPRITE,         "Sprite" },
  53     { ETHERTYPE_TRAIL,          "Trail" },
  54     { ETHERTYPE_MOPDL,          "MOP DL" },
  55     { ETHERTYPE_MOPRC,          "MOP RC" },
  56     { ETHERTYPE_DN,             "DN" },
  57     { ETHERTYPE_LAT,            "LAT" },
  58     { ETHERTYPE_SCA,            "SCA" },
  59     { ETHERTYPE_LANBRIDGE,      "Lanbridge" },
  60     { ETHERTYPE_DECDNS,         "DEC DNS" },
  61     { ETHERTYPE_DECDTS,         "DEC DTS" },
  62     { ETHERTYPE_VEXP,           "VEXP" },
  63     { ETHERTYPE_VPROD,          "VPROD" },
  64     { ETHERTYPE_ATALK,          "Appletalk" },
  65     { ETHERTYPE_AARP,           "Appletalk ARP" },
  66     { ETHERTYPE_IPX,            "IPX" },
  67     { ETHERTYPE_PPP,            "PPP" },
  68     { ETHERTYPE_PPPOED,         "PPPoE D" },
  69     { ETHERTYPE_PPPOES,         "PPPoE S" },
  70     { ETHERTYPE_EAPOL,          "EAPOL" },
  71     { ETHERTYPE_JUMBO,          "Jumbo" },
  72     { ETHERTYPE_LOOPBACK,       "Loopback" },
  73     { ETHERTYPE_ISO,            "OSI" },
  74     { 0, NULL}
  75 };
  76
  77 static inline void
  78 ether_hdr_print(register const u_char *bp, u_int length)
  79 {
  80         register const struct ether_header *ep;
  81         ep = (const struct ether_header *)bp;
  82
  83         (void)printf("%s > %s",
  84                      etheraddr_string(ESRC(ep)),
  85                      etheraddr_string(EDST(ep)));
  86
  87         if (!qflag) {
  88                 if (ntohs(ep->ether_type) <= ETHERMTU)
  89                           (void)printf(", 802.3");
  90                 else
  91                           (void)printf(", ethertype %s (0x%04x)",
  92                                        tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
  93                                        ntohs(ep->ether_type));
  94         } else {
  95                 if (ntohs(ep->ether_type) <= ETHERMTU)
  96                           (void)printf(", 802.3");
  97                 else
  98                           (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
  99         }
 100
 101         (void)printf(", length %u: ", length);
 102 }
 103
 104 void
 105 ether_print(const u_char *p, u_int length, u_int caplen)
 106 {
 107         struct ether_header *ep;
 108         u_short ether_type;
 109         u_short extracted_ether_type;
 110
 111         if (caplen < ETHER_HDRLEN) {
 112                 printf("[|ether]");
 113                 return;
 114         }
 115
 116         if (eflag)
 117                 ether_hdr_print(p, length);
 118
 119         length -= ETHER_HDRLEN;
 120         caplen -= ETHER_HDRLEN;
 121         ep = (struct ether_header *)p;
 122         p += ETHER_HDRLEN;
 123
 124         ether_type = ntohs(ep->ether_type);
 125
 126         /*
 127          * Is it (gag) an 802.3 encapsulation?
 128          */
 129         extracted_ether_type = 0;
 130         if (ether_type <= ETHERMTU) {
 131                 /* Try to print the LLC-layer header & higher layers */
 132                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
 133                     &extracted_ether_type) == 0) {
 134                         /* ether_type not known, print raw packet */
 135                         if (!eflag)
 136                                 ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 137
 138                         if (!xflag && !qflag)
 139                                 default_print(p, caplen);
 140                 }
 141         } else if (ether_encap_print(ether_type, p, length, caplen,
 142             &extracted_ether_type) == 0) {
 143                 /* ether_type not known, print raw packet */
 144                 if (!eflag)
 145                         ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 146
 147                 if (!xflag && !qflag)
 148                         default_print(p, caplen);
 149         }
 150 }
 151
 152 /*
 153  * This is the top level routine of the printer.  'p' points
 154  * to the ether header of the packet, 'h->ts' is the timestamp,
 155  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 156  * is the number of bytes actually captured.
 157  */
 158 u_int
 159 ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
 160 {
 161         ether_print(p, h->len, h->caplen);
 162
 163         return (ETHER_HDRLEN);
 164 }
 165
 166 /*
 167  * Prints the packet encapsulated in an Ethernet data segment
 168  * (or an equivalent encapsulation), given the Ethernet type code.
 169  *
 170  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 171  *
 172  * The Ethernet type code is passed through a pointer; if it was
 173  * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 174  * the 802.1Q payload, for the benefit of lower layers that might
 175  * want to know what it is.
 176  */
 177
 178 int
 179 ether_encap_print(u_short ether_type, const u_char *p,
 180     u_int length, u_int caplen, u_short *extracted_ether_type)
 181 {
 182  recurse:
 183         *extracted_ether_type = ether_type;
 184
 185         switch (ether_type) {
 186
 187         case ETHERTYPE_IP:
 188                 ip_print(p, length);
 189                 return (1);
 190
 191 #ifdef INET6
 192         case ETHERTYPE_IPV6:
 193                 ip6_print(p, length);
 194                 return (1);
 195 #endif /*INET6*/
 196
 197         case ETHERTYPE_ARP:
 198         case ETHERTYPE_REVARP:
 199                 arp_print(gndo, p, length, caplen);
 200                 return (1);
 201
 202         case ETHERTYPE_DN:
 203                 decnet_print(p, length, caplen);
 204                 return (1);
 205
 206         case ETHERTYPE_ATALK:
 207                 if (vflag)
 208                         fputs("et1 ", stdout);
 209                 atalk_print(p, length);
 210                 return (1);
 211
 212         case ETHERTYPE_AARP:
 213                 aarp_print(p, length);
 214                 return (1);
 215
 216         case ETHERTYPE_IPX:
 217                 printf("(NOV-ETHII) ");
 218                 ipx_print(p, length);
 219                 return (1);
 220
 221         case ETHERTYPE_8021Q:
 222                 if (eflag)
 223                     printf("vlan %u, p %u%s, ",
 224                            ntohs(*(u_int16_t *)p) & 0xfff,
 225                            ntohs(*(u_int16_t *)p) >> 13,
 226                            (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
 227
 228                 ether_type = ntohs(*(u_int16_t *)(p + 2));
 229                 p += 4;
 230                 length -= 4;
 231                 caplen -= 4;
 232
 233                 if (ether_type > ETHERMTU) {
 234                         if (eflag)
 235                                 printf("ethertype %s, ",
 236                                        tok2str(ethertype_values,"0x%04x", ether_type));
 237                         goto recurse;
 238                 }
 239
 240                 *extracted_ether_type = 0;
 241
 242                 if (llc_print(p, length, caplen, p - 18, p - 12,
 243                     extracted_ether_type) == 0) {
 244                                 ether_hdr_print(p - 18, length + 4);
 245                 }
 246
 247                 if (!xflag && !qflag)
 248                         default_print(p - 18, caplen + 4);
 249
 250                 return (1);
 251
 252         case ETHERTYPE_JUMBO:
 253                 ether_type = ntohs(*(u_int16_t *)(p));
 254                 p += 2;
 255                 length -= 2;
 256                 caplen -= 2;
 257
 258                 if (ether_type > ETHERMTU) {
 259                     if (eflag)
 260                         printf("ethertype %s, ",
 261                                tok2str(ethertype_values,"0x%04x", ether_type));
 262                     goto recurse;
 263                 }
 264
 265                 *extracted_ether_type = 0;
 266
 267                 if (llc_print(p, length, caplen, p - 16, p - 10,
 268                               extracted_ether_type) == 0) {
 269                     ether_hdr_print(p - 16, length + 2);
 270                 }
 271
 272                 if (!xflag && !qflag)
 273                     default_print(p - 16, caplen + 2);
 274
 275                 return (1);
 276
 277         case ETHERTYPE_ISO:
 278                 isoclns_print(p+1, length-1, length-1);
 279                 return(1);
 280
 281         case ETHERTYPE_PPPOED:
 282         case ETHERTYPE_PPPOES:
 283                 pppoe_print(p, length);
 284                 return (1);
 285
 286         case ETHERTYPE_EAPOL:
 287                 eap_print(gndo, p, length);
 288                 return (1);
 289
 290         case ETHERTYPE_PPP:
 291                 if (length) {
 292                         printf(": ");
 293                         ppp_print(p, length);
 294                 }
 295                 return (1);
 296
 297         case ETHERTYPE_LOOPBACK:
 298                 return (0);
 299
 300         case ETHERTYPE_MPLS:
 301         case ETHERTYPE_MPLS_MULTI:
 302                 mpls_print(p, length);
 303                 return (1);
 304
 305         case ETHERTYPE_LAT:
 306         case ETHERTYPE_SCA:
 307         case ETHERTYPE_MOPRC:
 308         case ETHERTYPE_MOPDL:
 309                 /* default_print for now */
 310         default:
 311                 return (0);
 312         }
 313 }
 314
 315 /*
 316  * Local Variables:
 317  * c-style: bsd
 318  * End:
 319  */
 320