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

   1 /*
   2  * Copyright (c) 1991, 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
  22 #ifndef lint
  23 static const char rcsid[] =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.35 2000-09-28 06:43:05 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/socket.h>
  34 #include <sys/file.h>
  35 #include <sys/ioctl.h>
  36
  37 struct mbuf;
  38 struct rtentry;
  39
  40 #include <netinet/in.h>
  41 #include <netinet/in_systm.h>
  42
  43 #include <pcap.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46
  47 #ifdef INET6
  48 #include <netinet/ip6.h>
  49 #endif
  50
  51 #include "interface.h"
  52 #include "addrtoname.h"
  53
  54 #include "ip.h"
  55
  56 #ifndef AF_NS
  57 #define AF_NS           6               /* XEROX NS protocols */
  58 #endif
  59
  60 /*
  61  * The DLT_NULL packet header is 4 bytes long. It contains a network
  62  * order 32 bit integer that specifies the family, e.g. AF_INET
  63  */
  64 #define NULL_HDRLEN 4
  65
  66 static void
  67 null_print(const u_char *p, const struct ip *ip, u_int length)
  68 {
  69         u_int family;
  70
  71         memcpy((char *)&family, (char *)p, sizeof(family));
  72
  73         if (nflag) {
  74                 /* XXX just dump the header */
  75                 return;
  76         }
  77         switch (family) {
  78
  79         case AF_INET:
  80                 printf("ip: ");
  81                 break;
  82
  83 #ifdef INET6
  84         case AF_INET6:
  85                 printf("ip6: ");
  86                 break;
  87 #endif
  88
  89         case AF_NS:
  90                 printf("ns: ");
  91                 break;
  92
  93         default:
  94                 printf("AF %d: ", family);
  95                 break;
  96         }
  97 }
  98
  99 void
 100 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
 101 {
 102         u_int length = h->len;
 103         u_int caplen = h->caplen;
 104         const struct ip *ip;
 105
 106         ts_print(&h->ts);
 107
 108         /*
 109          * Some printers want to get back at the link level addresses,
 110          * and/or check that they're not walking off the end of the packet.
 111          * Rather than pass them all the way down, we set these globals.
 112          */
 113         packetp = p;
 114         snapend = p + caplen;
 115
 116         length -= NULL_HDRLEN;
 117
 118         ip = (struct ip *)(p + NULL_HDRLEN);
 119
 120         if (eflag)
 121                 null_print(p, ip, length);
 122
 123         switch (ip->ip_v) {
 124         case 4:
 125                 ip_print((const u_char *)ip, length);
 126                 break;
 127 #ifdef INET6
 128         case 6:
 129                 ip6_print((const u_char *)ip, length);
 130                 break;
 131 #endif /* INET6 */
 132         default:
 133                 printf("ip v%d", ip->ip_v);
 134                 break;
 135         }
 136
 137         if (xflag)
 138                 default_print((const u_char *)ip, caplen - NULL_HDRLEN);
 139         putchar('\n');
 140 }
 141