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

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   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[] =
  23     "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.51 2000-07-01 03:39:02 assar Exp $ (LBL)";
  24 #endif
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <sys/param.h>
  31 #include <sys/time.h>
  32 #include <sys/socket.h>
  33
  34 struct mbuf;
  35 struct rtentry;
  36 #include <net/if.h>
  37
  38 #include <netinet/in.h>
  39 #include <netinet/if_ether.h>
  40 #include <netinet/in_systm.h>
  41 #include <netinet/ip.h>
  42 #include <netinet/ip_var.h>
  43 #include <netinet/udp.h>
  44 #include <netinet/udp_var.h>
  45 #include <netinet/tcp.h>
  46
  47 #include <stdio.h>
  48 #include <pcap.h>
  49
  50 #ifdef INET6
  51 #include <netinet/ip6.h>
  52 #endif
  53
  54 #include "interface.h"
  55 #include "addrtoname.h"
  56 #include "ethertype.h"
  57
  58 const u_char *packetp;
  59 const u_char *snapend;
  60
  61 static inline void
  62 ether_print(register const u_char *bp, u_int length)
  63 {
  64         register const struct ether_header *ep;
  65
  66         ep = (const struct ether_header *)bp;
  67         if (qflag)
  68                 (void)printf("%s %s %d: ",
  69                              etheraddr_string(ESRC(ep)),
  70                              etheraddr_string(EDST(ep)),
  71                              length);
  72         else
  73                 (void)printf("%s %s %s %d: ",
  74                              etheraddr_string(ESRC(ep)),
  75                              etheraddr_string(EDST(ep)),
  76                              etherproto_string(ep->ether_type),
  77                              length);
  78 }
  79
  80 static u_short extracted_ethertype;
  81
  82 /*
  83  * This is the top level routine of the printer.  'p' is the points
  84  * to the ether header of the packet, 'h->tv' is the timestamp,
  85  * 'h->length' is the length of the packet off the wire, and 'h->caplen'
  86  * is the number of bytes actually captured.
  87  */
  88 void
  89 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  90 {
  91         u_int caplen = h->caplen;
  92         u_int length = h->len;
  93         struct ether_header *ep;
  94         u_short ether_type;
  95
  96         ts_print(&h->ts);
  97
  98         if (caplen < sizeof(struct ether_header)) {
  99                 printf("[|ether]");
 100                 goto out;
 101         }
 102
 103         if (eflag)
 104                 ether_print(p, length);
 105
 106         /*
 107          * Some printers want to get back at the ethernet addresses,
 108          * and/or check that they're not walking off the end of the packet.
 109          * Rather than pass them all the way down, we set these globals.
 110          */
 111         packetp = p;
 112         snapend = p + caplen;
 113
 114         length -= sizeof(struct ether_header);
 115         caplen -= sizeof(struct ether_header);
 116         ep = (struct ether_header *)p;
 117         p += sizeof(struct ether_header);
 118
 119         ether_type = ntohs(ep->ether_type);
 120
 121         /*
 122          * Is it (gag) an 802.3 encapsulation?
 123          */
 124         extracted_ethertype = 0;
 125         if (ether_type <= ETHERMTU) {
 126                 /* Try to print the LLC-layer header & higher layers */
 127                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) {
 128                         /* ether_type not known, print raw packet */
 129                         if (!eflag)
 130                                 ether_print((u_char *)ep, length);
 131                         if (extracted_ethertype) {
 132                                 printf("(LLC %s) ",
 133                                etherproto_string(htons(extracted_ethertype)));
 134                         }
 135                         if (!xflag && !qflag)
 136                                 default_print(p, caplen);
 137                 }
 138         } else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
 139                 /* ether_type not known, print raw packet */
 140                 if (!eflag)
 141                         ether_print((u_char *)ep, length + sizeof(*ep));
 142                 if (!xflag && !qflag)
 143                         default_print(p, caplen);
 144         }
 145         if (xflag)
 146                 default_print(p, caplen);
 147  out:
 148         putchar('\n');
 149 }
 150
 151 /*
 152  * Prints the packet encapsulated in an Ethernet data segment
 153  * (or an equivalent encapsulation), given the Ethernet type code.
 154  *
 155  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 156  *
 157  * Stuffs the ether type into a global for the benefit of lower layers
 158  * that might want to know what it is.
 159  */
 160
 161 int
 162 ether_encap_print(u_short ethertype, const u_char *p,
 163     u_int length, u_int caplen)
 164 {
 165  recurse:
 166         extracted_ethertype = ethertype;
 167
 168         switch (ethertype) {
 169
 170         case ETHERTYPE_IP:
 171                 ip_print(p, length);
 172                 return (1);
 173
 174 #ifdef INET6
 175         case ETHERTYPE_IPV6:
 176                 ip6_print(p, length);
 177                 return (1);
 178 #endif /*INET6*/
 179
 180         case ETHERTYPE_ARP:
 181         case ETHERTYPE_REVARP:
 182                 arp_print(p, length, caplen);
 183                 return (1);
 184
 185         case ETHERTYPE_DN:
 186                 decnet_print(p, length, caplen);
 187                 return (1);
 188
 189         case ETHERTYPE_ATALK:
 190                 if (vflag)
 191                         fputs("et1 ", stdout);
 192                 atalk_print(p, length);
 193                 return (1);
 194
 195         case ETHERTYPE_AARP:
 196                 aarp_print(p, length);
 197                 return (1);
 198
 199         case ETHERTYPE_IPX:
 200                 ipx_print(p, length);
 201                 return (1);
 202
 203         case ETHERTYPE_8021Q:
 204                 printf("802.1Q vlan#%d P%d%s",
 205                        ntohs(*(u_int16_t *)p) & 0xfff,
 206                        ntohs(*(u_int16_t *)p) >> 13,
 207                        (ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : "");
 208                 ethertype = ntohs(*(u_int16_t *)(p + 2));
 209                 p += 4;
 210                 length -= 4;
 211                 caplen -= 4;
 212                 if (ethertype > ETHERMTU)
 213                         goto recurse;
 214
 215                 extracted_ethertype = 0;
 216
 217                 if (llc_print(p, length, caplen, p - 18, p - 12) == 0) {
 218                         /* ether_type not known, print raw packet */
 219                         if (!eflag)
 220                                 ether_print(p - 18, length + 4);
 221                         if (extracted_ethertype) {
 222                                 printf("(LLC %s) ",
 223                                etherproto_string(htons(extracted_ethertype)));
 224                         }
 225                         if (!xflag && !qflag)
 226                                 default_print(p - 18, caplen + 4);
 227                 }
 228                 return (1);
 229
 230         case ETHERTYPE_PPPOED:
 231         case ETHERTYPE_PPPOES:
 232                 pppoe_print(p, length);
 233                 return (1);
 234
 235         case ETHERTYPE_LAT:
 236         case ETHERTYPE_SCA:
 237         case ETHERTYPE_MOPRC:
 238         case ETHERTYPE_MOPDL:
 239                 /* default_print for now */
 240         default:
 241                 return (0);
 242         }
 243 }