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 1.95 2005-04-06 21:32:39 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 #include "llc.h"
  41
  42 const struct tok ethertype_values[] = {
  43     /* not really ethertypes but PIDs that are used
  44        in the SNAP printer - its more convenient
  45        to put them into a single tokentable */
  46     { PID_RFC2684_ETH_FCS,      "Ethernet + FCS" },
  47     { PID_RFC2684_ETH_NOFCS,    "Ethernet no FCS" },
  48     { PID_RFC2684_802_4_FCS,    "802.4 + FCS" },
  49     { PID_RFC2684_802_4_NOFCS,  "w/o FCS" },
  50     { PID_RFC2684_802_5_FCS,    "Tokenring + FCS" },
  51     { PID_RFC2684_802_5_NOFCS,  "Tokenring no FCS" },
  52     { PID_RFC2684_FDDI_FCS,     "FDDI + FCS" },
  53     { PID_RFC2684_FDDI_NOFCS,   "FDDI no FCS" },
  54     { PID_RFC2684_802_6_FCS,    "802.6 + FCS" },
  55     { PID_RFC2684_802_6_NOFCS,  "802.6 no FCS" },
  56     { PID_RFC2684_BPDU,         "BPDU" },
  57     /* the real Ethertypes */
  58     { ETHERTYPE_IP,             "IPv4" },
  59     { ETHERTYPE_MPLS,           "MPLS unicast" },
  60     { ETHERTYPE_MPLS_MULTI,     "MPLS multicast" },
  61     { ETHERTYPE_IPV6,           "IPv6" },
  62     { ETHERTYPE_8021Q,          "802.1Q" },
  63     { ETHERTYPE_VMAN,           "VMAN" },
  64     { ETHERTYPE_PUP,            "PUP" },
  65     { ETHERTYPE_ARP,            "ARP"},
  66     { ETHERTYPE_REVARP ,        "Reverse ARP"},
  67     { ETHERTYPE_NS,             "NS" },
  68     { ETHERTYPE_SPRITE,         "Sprite" },
  69     { ETHERTYPE_TRAIL,          "Trail" },
  70     { ETHERTYPE_MOPDL,          "MOP DL" },
  71     { ETHERTYPE_MOPRC,          "MOP RC" },
  72     { ETHERTYPE_DN,             "DN" },
  73     { ETHERTYPE_LAT,            "LAT" },
  74     { ETHERTYPE_SCA,            "SCA" },
  75     { ETHERTYPE_LANBRIDGE,      "Lanbridge" },
  76     { ETHERTYPE_DECDNS,         "DEC DNS" },
  77     { ETHERTYPE_DECDTS,         "DEC DTS" },
  78     { ETHERTYPE_VEXP,           "VEXP" },
  79     { ETHERTYPE_VPROD,          "VPROD" },
  80     { ETHERTYPE_ATALK,          "Appletalk" },
  81     { ETHERTYPE_AARP,           "Appletalk ARP" },
  82     { ETHERTYPE_IPX,            "IPX" },
  83     { ETHERTYPE_PPP,            "PPP" },
  84     { ETHERTYPE_PPPOED,         "PPPoE D" },
  85     { ETHERTYPE_PPPOES,         "PPPoE S" },
  86     { ETHERTYPE_EAPOL,          "EAPOL" },
  87     { ETHERTYPE_JUMBO,          "Jumbo" },
  88     { ETHERTYPE_LOOPBACK,       "Loopback" },
  89     { ETHERTYPE_ISO,            "OSI" },
  90     { ETHERTYPE_GRE_ISO,        "GRE-OSI" },
  91     { 0, NULL}
  92 };
  93
  94 static inline void
  95 ether_hdr_print(register const u_char *bp, u_int length)
  96 {
  97         register const struct ether_header *ep;
  98         ep = (const struct ether_header *)bp;
  99
 100         (void)printf("%s > %s",
 101                      etheraddr_string(ESRC(ep)),
 102                      etheraddr_string(EDST(ep)));
 103
 104         if (!qflag) {
 105                 if (ntohs(ep->ether_type) <= ETHERMTU)
 106                           (void)printf(", 802.3");
 107                 else
 108                           (void)printf(", ethertype %s (0x%04x)",
 109                                        tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
 110                                        ntohs(ep->ether_type));
 111         } else {
 112                 if (ntohs(ep->ether_type) <= ETHERMTU)
 113                           (void)printf(", 802.3");
 114                 else
 115                           (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));
 116         }
 117
 118         (void)printf(", length %u: ", length);
 119 }
 120
 121 void
 122 ether_print(const u_char *p, u_int length, u_int caplen)
 123 {
 124         struct ether_header *ep;
 125         u_short ether_type;
 126         u_short extracted_ether_type;
 127
 128         if (caplen < ETHER_HDRLEN) {
 129                 printf("[|ether]");
 130                 return;
 131         }
 132
 133         if (eflag)
 134                 ether_hdr_print(p, length);
 135
 136         length -= ETHER_HDRLEN;
 137         caplen -= ETHER_HDRLEN;
 138         ep = (struct ether_header *)p;
 139         p += ETHER_HDRLEN;
 140
 141         ether_type = ntohs(ep->ether_type);
 142
 143         /*
 144          * Is it (gag) an 802.3 encapsulation?
 145          */
 146         extracted_ether_type = 0;
 147         if (ether_type <= ETHERMTU) {
 148                 /* Try to print the LLC-layer header & higher layers */
 149                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
 150                     &extracted_ether_type) == 0) {
 151                         /* ether_type not known, print raw packet */
 152                         if (!eflag)
 153                                 ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 154
 155                         if (!xflag && !qflag)
 156                                 default_print(p, caplen);
 157                 }
 158         } else if (ether_encap_print(ether_type, p, length, caplen,
 159             &extracted_ether_type) == 0) {
 160                 /* ether_type not known, print raw packet */
 161                 if (!eflag)
 162                         ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
 163
 164                 if (!xflag && !qflag)
 165                         default_print(p, caplen);
 166         }
 167 }
 168
 169 /*
 170  * This is the top level routine of the printer.  'p' points
 171  * to the ether header of the packet, 'h->ts' is the timestamp,
 172  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 173  * is the number of bytes actually captured.
 174  */
 175 u_int
 176 ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
 177 {
 178         ether_print(p, h->len, h->caplen);
 179
 180         return (ETHER_HDRLEN);
 181 }
 182
 183 /*
 184  * Prints the packet encapsulated in an Ethernet data segment
 185  * (or an equivalent encapsulation), given the Ethernet type code.
 186  *
 187  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 188  *
 189  * The Ethernet type code is passed through a pointer; if it was
 190  * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 191  * the 802.1Q payload, for the benefit of lower layers that might
 192  * want to know what it is.
 193  */
 194
 195 int
 196 ether_encap_print(u_short ether_type, const u_char *p,
 197     u_int length, u_int caplen, u_short *extracted_ether_type)
 198 {
 199  recurse:
 200         *extracted_ether_type = ether_type;
 201
 202         switch (ether_type) {
 203
 204         case ETHERTYPE_IP:
 205                 ip_print(gndo, p, length);
 206                 return (1);
 207
 208 #ifdef INET6
 209         case ETHERTYPE_IPV6:
 210                 ip6_print(p, length);
 211                 return (1);
 212 #endif /*INET6*/
 213
 214         case ETHERTYPE_ARP:
 215         case ETHERTYPE_REVARP:
 216                 arp_print(gndo, p, length, caplen);
 217                 return (1);
 218
 219         case ETHERTYPE_DN:
 220                 decnet_print(p, length, caplen);
 221                 return (1);
 222
 223         case ETHERTYPE_ATALK:
 224                 if (vflag)
 225                         fputs("et1 ", stdout);
 226                 atalk_print(p, length);
 227                 return (1);
 228
 229         case ETHERTYPE_AARP:
 230                 aarp_print(p, length);
 231                 return (1);
 232
 233         case ETHERTYPE_IPX:
 234                 printf("(NOV-ETHII) ");
 235                 ipx_print(p, length);
 236                 return (1);
 237
 238         case ETHERTYPE_8021Q:
 239                 if (eflag)
 240                     printf("vlan %u, p %u%s, ",
 241                            ntohs(*(u_int16_t *)p) & 0xfff,
 242                            ntohs(*(u_int16_t *)p) >> 13,
 243                            (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");
 244
 245                 ether_type = ntohs(*(u_int16_t *)(p + 2));
 246                 p += 4;
 247                 length -= 4;
 248                 caplen -= 4;
 249
 250                 if (ether_type > ETHERMTU) {
 251                         if (eflag)
 252                                 printf("ethertype %s, ",
 253                                        tok2str(ethertype_values,"0x%04x", ether_type));
 254                         goto recurse;
 255                 }
 256
 257                 *extracted_ether_type = 0;
 258
 259                 if (llc_print(p, length, caplen, p - 18, p - 12,
 260                     extracted_ether_type) == 0) {
 261                                 ether_hdr_print(p - 18, length + 4);
 262                 }
 263
 264                 if (!xflag && !qflag)
 265                         default_print(p - 18, caplen + 4);
 266
 267                 return (1);
 268
 269         case ETHERTYPE_JUMBO:
 270                 ether_type = ntohs(*(u_int16_t *)(p));
 271                 p += 2;
 272                 length -= 2;
 273                 caplen -= 2;
 274
 275                 if (ether_type > ETHERMTU) {
 276                     if (eflag)
 277                         printf("ethertype %s, ",
 278                                tok2str(ethertype_values,"0x%04x", ether_type));
 279                     goto recurse;
 280                 }
 281
 282                 *extracted_ether_type = 0;
 283
 284                 if (llc_print(p, length, caplen, p - 16, p - 10,
 285                               extracted_ether_type) == 0) {
 286                     ether_hdr_print(p - 16, length + 2);
 287                 }
 288
 289                 if (!xflag && !qflag)
 290                     default_print(p - 16, caplen + 2);
 291
 292                 return (1);
 293
 294         case ETHERTYPE_ISO:
 295                 isoclns_print(p+1, length-1, length-1);
 296                 return(1);
 297
 298         case ETHERTYPE_PPPOED:
 299         case ETHERTYPE_PPPOES:
 300                 pppoe_print(p, length);
 301                 return (1);
 302
 303         case ETHERTYPE_EAPOL:
 304                 eap_print(gndo, p, length);
 305                 return (1);
 306
 307         case ETHERTYPE_PPP:
 308                 if (length) {
 309                         printf(": ");
 310                         ppp_print(p, length);
 311                 }
 312                 return (1);
 313
 314         case ETHERTYPE_LOOPBACK:
 315                 return (0);
 316
 317         case ETHERTYPE_MPLS:
 318         case ETHERTYPE_MPLS_MULTI:
 319                 mpls_print(p, length);
 320                 return (1);
 321
 322         case ETHERTYPE_LAT:
 323         case ETHERTYPE_SCA:
 324         case ETHERTYPE_MOPRC:
 325         case ETHERTYPE_MOPDL:
 326                 /* default_print for now */
 327         default:
 328                 return (0);
 329         }
 330 }
 331
 332
 333 /*
 334  * Local Variables:
 335  * c-style: whitesmith
 336  * c-basic-offset: 8
 337  * End:
 338  */
 339