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 1.25 1999-10-17 21:37:14 mcr Exp $ (LBL)";
  25 #endif
  26
  27 #include <sys/param.h>
  28 #include <sys/time.h>
  29 #include <sys/socket.h>
  30 #include <sys/file.h>
  31 #include <sys/ioctl.h>
  32
  33 #if __STDC__
  34 struct mbuf;
  35 struct rtentry;
  36 #endif
  37 #include <net/if.h>
  38
  39 #include <netinet/in.h>
  40 #include <netinet/in_systm.h>
  41 #include <netinet/ip.h>
  42 #include <netinet/if_ether.h>
  43 #include <netinet/udp.h>
  44 #include <netinet/tcp.h>
  45
  46 #include <pcap.h>
  47 #include <stdio.h>
  48 #include <string.h>
  49
  50 #include "interface.h"
  51 #include "addrtoname.h"
  52
  53 #ifndef AF_NS
  54 #define AF_NS           6               /* XEROX NS protocols */
  55 #endif
  56
  57 /*
  58  * The DLT_NULL packet header is 4 bytes long. It contains a network
  59  * order 32 bit integer that specifies the family, e.g. AF_INET
  60  */
  61 #define NULL_HDRLEN 4
  62
  63 static void
  64 null_print(const u_char *p, const struct ip *ip, u_int length)
  65 {
  66         u_int family;
  67
  68         memcpy((char *)&family, (char *)p, sizeof(family));
  69
  70         if (nflag) {
  71                 /* XXX just dump the header */
  72                 return;
  73         }
  74         switch (family) {
  75
  76         case AF_INET:
  77                 printf("ip: ");
  78                 break;
  79
  80         case AF_NS:
  81                 printf("ns: ");
  82                 break;
  83
  84         default:
  85                 printf("AF %d: ", family);
  86                 break;
  87         }
  88 }
  89
  90 void
  91 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  92 {
  93         u_int length = h->len;
  94         u_int caplen = h->caplen;
  95         const struct ip *ip;
  96
  97         ts_print(&h->ts);
  98
  99         /*
 100          * Some printers want to get back at the link level addresses,
 101          * and/or check that they're not walking off the end of the packet.
 102          * Rather than pass them all the way down, we set these globals.
 103          */
 104         packetp = p;
 105         snapend = p + caplen;
 106
 107         length -= NULL_HDRLEN;
 108
 109         ip = (struct ip *)(p + NULL_HDRLEN);
 110
 111         if (eflag)
 112                 null_print(p, ip, length);
 113
 114         ip_print((const u_char *)ip, length);
 115
 116         if (xflag)
 117                 default_print((const u_char *)ip, caplen - NULL_HDRLEN);
 118         putchar('\n');
 119 }
 120