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 1.38 2000-10-07 05:53:13 itojun 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
  42 #include <pcap.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45
  46 #include "interface.h"
  47 #include "addrtoname.h"
  48
  49 #include "ip.h"
  50 #ifdef INET6
  51 #include "ip6.h"
  52 #endif
  53
  54 #ifndef AF_NS
  55 #define AF_NS           6               /* XEROX NS protocols */
  56 #endif
  57
  58 /*
  59  * The DLT_NULL packet header is 4 bytes long. It contains a network
  60  * order 32 bit integer that specifies the family, e.g. AF_INET
  61  */
  62 #define NULL_HDRLEN 4
  63
  64 static void
  65 null_print(const u_char *p, const struct ip *ip, u_int length)
  66 {
  67         u_int family;
  68
  69         memcpy((char *)&family, (char *)p, sizeof(family));
  70
  71         if (nflag) {
  72                 /* XXX just dump the header */
  73                 return;
  74         }
  75         switch (family) {
  76
  77         case AF_INET:
  78                 printf("ip: ");
  79                 break;
  80
  81 #ifdef INET6
  82         case AF_INET6:
  83                 printf("ip6: ");
  84                 break;
  85 #endif
  86
  87         case AF_NS:
  88                 printf("ns: ");
  89                 break;
  90
  91         default:
  92                 printf("AF %d: ", family);
  93                 break;
  94         }
  95 }
  96
  97 void
  98 null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  99 {
 100         u_int length = h->len;
 101         u_int caplen = h->caplen;
 102         const struct ip *ip;
 103
 104         ts_print(&h->ts);
 105
 106         /*
 107          * Some printers want to get back at the link level 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 -= NULL_HDRLEN;
 115
 116         ip = (struct ip *)(p + NULL_HDRLEN);
 117
 118         if (eflag)
 119                 null_print(p, ip, length);
 120
 121         switch (IP_V(ip)) {
 122         case 4:
 123                 ip_print((const u_char *)ip, length);
 124                 break;
 125 #ifdef INET6
 126         case 6:
 127                 ip6_print((const u_char *)ip, length);
 128                 break;
 129 #endif /* INET6 */
 130         default:
 131                 printf("ip v%d", IP_V(ip));
 132                 break;
 133         }
 134
 135         if (xflag)
 136                 default_print((const u_char *)ip, caplen - NULL_HDRLEN);
 137         putchar('\n');
 138 }
 139