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 1.82.2.3 2003-12-29 22:42:21 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_LOOPBACK,       "Loopback" },
  73     { 0, NULL}
  74 };
  75
  76 static inline void
  77 ether_hdr_print(register const u_char *bp, u_int length)
  78 {
  79         register const struct ether_header *ep;
  80         ep = (const struct ether_header *)bp;
  81
  82         (void)printf("%s > %s",
  83                      etheraddr_string(ESRC(ep)),
  84                      etheraddr_string(EDST(ep)));
  85
  86         if (!qflag) {
  87                 if (ntohs(ep->ether_type) <= ETHERMTU)
  88                           (void)printf(", 802.3");
  89                 else
  90                           (void)printf(", ethertype %s (0x%04x)",
  91                                        tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
  92                                        ntohs(ep->ether_type));
  93         } else {
  94                 if (ntohs(ep->ether_type) <= ETHERMTU)
  95                           (void)printf(", 802.3");
  96                 else
  97                           (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
  98         }
  99
 100         (void)printf(", length %u: ", length);
 101 }
 102
 103 void
 104 ether_print(const u_char *p, u_int length, u_int caplen)
 105 {
 106         struct ether_header *ep;
 107         u_short ether_type;
 108         u_short extracted_ether_type;
 109
 110         if (caplen < ETHER_HDRLEN) {
 111                 printf("[|ether]");
 112                 return;
 113         }
 114
 115         if (eflag)
 116                 ether_hdr_print(p, length);
 117
 118         length -= ETHER_HDRLEN;
 119         caplen -= ETHER_HDRLEN;
 120         ep = (struct ether_header *)p;
 121         p += ETHER_HDRLEN;
 122
 123         ether_type = ntohs(ep->ether_type);
 124
 125         /*
 126          * Is it (gag) an 802.3 encapsulation?
 127          */
 128         extracted_ether_type = 0;
 129         if (ether_type <= ETHERMTU) {
 130                 /* Try to print the LLC-layer header & higher layers */
 131                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
 132                     &extracted_ether_type) == 0) {
 133                         /* ether_type not known, print raw packet */
 134                         if (!eflag)
 135                                 ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 136
 137                         if (!xflag && !qflag)
 138                                 default_print(p, caplen);
 139                 }
 140         } else if (ether_encap_print(ether_type, p, length, caplen,
 141             &extracted_ether_type) == 0) {
 142                 /* ether_type not known, print raw packet */
 143                 if (!eflag)
 144                         ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 145
 146                 if (!xflag && !qflag)
 147                         default_print(p, caplen);
 148         }
 149 }
 150
 151 /*
 152  * This is the top level routine of the printer.  'p' points
 153  * to the ether header of the packet, 'h->ts' is the timestamp,
 154  * 'h->length' is the length of the packet off the wire, and 'h->caplen'
 155  * is the number of bytes actually captured.
 156  */
 157 u_int
 158 ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
 159 {
 160         ether_print(p, h->len, h->caplen);
 161
 162         return (ETHER_HDRLEN);
 163 }
 164
 165 /*
 166  * Prints the packet encapsulated in an Ethernet data segment
 167  * (or an equivalent encapsulation), given the Ethernet type code.
 168  *
 169  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 170  *
 171  * The Ethernet type code is passed through a pointer; if it was
 172  * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 173  * the 802.1Q payload, for the benefit of lower layers that might
 174  * want to know what it is.
 175  */
 176
 177 int
 178 ether_encap_print(u_short ether_type, const u_char *p,
 179     u_int length, u_int caplen, u_short *extracted_ether_type)
 180 {
 181  recurse:
 182         *extracted_ether_type = ether_type;
 183
 184         switch (ether_type) {
 185
 186         case ETHERTYPE_IP:
 187                 ip_print(p, length);
 188                 return (1);
 189
 190 #ifdef INET6
 191         case ETHERTYPE_IPV6:
 192                 ip6_print(p, length);
 193                 return (1);
 194 #endif /*INET6*/
 195
 196         case ETHERTYPE_ARP:
 197         case ETHERTYPE_REVARP:
 198                 arp_print(p, length, caplen);
 199                 return (1);
 200
 201         case ETHERTYPE_DN:
 202                 decnet_print(p, length, caplen);
 203                 return (1);
 204
 205         case ETHERTYPE_ATALK:
 206                 if (vflag)
 207                         fputs("et1 ", stdout);
 208                 atalk_print(p, length);
 209                 return (1);
 210
 211         case ETHERTYPE_AARP:
 212                 aarp_print(p, length);
 213                 return (1);
 214
 215         case ETHERTYPE_IPX:
 216                 printf("(NOV-ETHII) ");
 217                 ipx_print(p, length);
 218                 return (1);
 219
 220         case ETHERTYPE_8021Q:
 221                 if (eflag)
 222                     printf("vlan %u, p %u%s, ",
 223                            ntohs(*(u_int16_t *)p) & 0xfff,
 224                            ntohs(*(u_int16_t *)p) >> 13,
 225                            (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
 226
 227                 ether_type = ntohs(*(u_int16_t *)(p + 2));
 228                 p += 4;
 229                 length -= 4;
 230                 caplen -= 4;
 231
 232                 if (ether_type > ETHERMTU) {
 233                         if (eflag)
 234                                 printf("ethertype %s, ",
 235                                        tok2str(ethertype_values,"0x%04x", ether_type));
 236                         goto recurse;
 237                 }
 238
 239                 *extracted_ether_type = 0;
 240
 241                 if (llc_print(p, length, caplen, p - 18, p - 12,
 242                     extracted_ether_type) == 0) {
 243                                 ether_hdr_print(p - 18, length + 4);
 244                 }
 245
 246                 if (!xflag && !qflag)
 247                         default_print(p - 18, caplen + 4);
 248
 249                 return (1);
 250
 251         case ETHERTYPE_PPPOED:
 252         case ETHERTYPE_PPPOES:
 253                 pppoe_print(p, length);
 254                 return (1);
 255
 256         case ETHERTYPE_PPP:
 257                 if (length) {
 258                         printf(": ");
 259                         ppp_print(p, length);
 260                 }
 261                 return (1);
 262
 263         case ETHERTYPE_LOOPBACK:
 264                 return (0);
 265
 266         case ETHERTYPE_MPLS:
 267         case ETHERTYPE_MPLS_MULTI:
 268                 mpls_print(p, length);
 269                 return (1);
 270
 271         case ETHERTYPE_LAT:
 272         case ETHERTYPE_SCA:
 273         case ETHERTYPE_MOPRC:
 274         case ETHERTYPE_MOPDL:
 275                 /* default_print for now */
 276         default:
 277                 return (0);
 278         }
 279 }