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 1.46 1999-10-30 05:11:13 itojun Exp $ (LBL)";
  24 #endif
  25
  26 #include <sys/param.h>
  27 #include <sys/time.h>
  28 #include <sys/socket.h>
  29
  30 #if __STDC__
  31 struct mbuf;
  32 struct rtentry;
  33 #endif
  34 #include <net/if.h>
  35
  36 #include <netinet/in.h>
  37 #include <netinet/if_ether.h>
  38 #include <netinet/in_systm.h>
  39 #include <netinet/ip.h>
  40 #include <netinet/ip_var.h>
  41 #include <netinet/udp.h>
  42 #include <netinet/udp_var.h>
  43 #include <netinet/tcp.h>
  44
  45 #include <stdio.h>
  46 #include <pcap.h>
  47
  48 #ifdef INET6
  49 #include <netinet/ip6.h>
  50 #endif
  51
  52 #include "interface.h"
  53 #include "addrtoname.h"
  54 #include "ethertype.h"
  55
  56 const u_char *packetp;
  57 const u_char *snapend;
  58
  59 static inline void
  60 ether_print(register const u_char *bp, u_int length)
  61 {
  62         register const struct ether_header *ep;
  63
  64         ep = (const struct ether_header *)bp;
  65         if (qflag)
  66                 (void)printf("%s %s %d: ",
  67                              etheraddr_string(ESRC(ep)),
  68                              etheraddr_string(EDST(ep)),
  69                              length);
  70         else
  71                 (void)printf("%s %s %s %d: ",
  72                              etheraddr_string(ESRC(ep)),
  73                              etheraddr_string(EDST(ep)),
  74                              etherproto_string(ep->ether_type),
  75                              length);
  76 }
  77
  78 /*
  79  * This is the top level routine of the printer.  'p' is the points
  80  * to the ether header of the packet, 'tvp' is the timestamp,
  81  * 'length' is the length of the packet off the wire, and 'caplen'
  82  * is the number of bytes actually captured.
  83  */
  84 void
  85 ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  86 {
  87         u_int caplen = h->caplen;
  88         u_int length = h->len;
  89         struct ether_header *ep;
  90         u_short ether_type;
  91         extern u_short extracted_ethertype;
  92
  93         ts_print(&h->ts);
  94
  95         if (caplen < sizeof(struct ether_header)) {
  96                 printf("[|ether]");
  97                 goto out;
  98         }
  99
 100         if (eflag)
 101                 ether_print(p, length);
 102
 103         /*
 104          * Some printers want to get back at the ethernet addresses,
 105          * and/or check that they're not walking off the end of the packet.
 106          * Rather than pass them all the way down, we set these globals.
 107          */
 108         packetp = p;
 109         snapend = p + caplen;
 110
 111         length -= sizeof(struct ether_header);
 112         caplen -= sizeof(struct ether_header);
 113         ep = (struct ether_header *)p;
 114         p += sizeof(struct ether_header);
 115
 116         ether_type = ntohs(ep->ether_type);
 117
 118         /*
 119          * Is it (gag) an 802.3 encapsulation?
 120          */
 121         extracted_ethertype = 0;
 122         if (ether_type <= ETHERMTU) {
 123                 /* Try to print the LLC-layer header & higher layers */
 124                 if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) {
 125                         /* ether_type not known, print raw packet */
 126                         if (!eflag)
 127                                 ether_print((u_char *)ep, length);
 128                         if (extracted_ethertype) {
 129                                 printf("(LLC %s) ",
 130                                etherproto_string(htons(extracted_ethertype)));
 131                         }
 132                         if (!xflag && !qflag)
 133                                 default_print(p, caplen);
 134                 }
 135         } else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
 136                 /* ether_type not known, print raw packet */
 137                 if (!eflag)
 138                         ether_print((u_char *)ep, length + sizeof(*ep));
 139                 if (!xflag && !qflag)
 140                         default_print(p, caplen);
 141         }
 142         if (xflag)
 143                 default_print(p, caplen);
 144  out:
 145         putchar('\n');
 146 }
 147
 148 /*
 149  * Prints the packet encapsulated in an Ethernet data segment
 150  * (or an equivalent encapsulation), given the Ethernet type code.
 151  *
 152  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 153  *
 154  * Stuffs the ether type into a global for the benefit of lower layers
 155  * that might want to know what it is.
 156  */
 157
 158 u_short extracted_ethertype;
 159
 160 int
 161 ether_encap_print(u_short ethertype, const u_char *p,
 162     u_int length, u_int caplen)
 163 {
 164         extracted_ethertype = ethertype;
 165
 166         switch (ethertype) {
 167
 168         case ETHERTYPE_IP:
 169                 ip_print(p, length);
 170                 return (1);
 171
 172 #ifdef INET6
 173         case ETHERTYPE_IPV6:
 174                 ip6_print(p, length);
 175                 return (1);
 176 #endif /*INET6*/
 177
 178         case ETHERTYPE_ARP:
 179         case ETHERTYPE_REVARP:
 180                 arp_print(p, length, caplen);
 181                 return (1);
 182
 183         case ETHERTYPE_DN:
 184                 decnet_print(p, length, caplen);
 185                 return (1);
 186
 187         case ETHERTYPE_ATALK:
 188                 if (vflag)
 189                         fputs("et1 ", stdout);
 190                 atalk_print(p, length);
 191                 return (1);
 192
 193         case ETHERTYPE_AARP:
 194                 aarp_print(p, length);
 195                 return (1);
 196
 197         case ETHERTYPE_LAT:
 198         case ETHERTYPE_SCA:
 199         case ETHERTYPE_MOPRC:
 200         case ETHERTYPE_MOPDL:
 201                 /* default_print for now */
 202         default:
 203                 return (0);
 204         }
 205 }