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[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.53.2.4 2007/02/26 13:31:33 hannes Exp $ (LBL)";
25 #endif
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include <tcpdump-stdinc.h>
32
33 #include <pcap.h>
34 #include <stdio.h>
35 #include <string.h>
36
37 #include "interface.h"
38 #include "addrtoname.h"
39 #include "af.h"
40
41 #include "ip.h"
42 #ifdef INET6
43 #include "ip6.h"
44 #endif
45
46 /*
47 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order
48 * 32-bit integer that specifies the family, e.g. AF_INET.
49 *
50 * Note here that "host" refers to the host on which the packets were
51 * captured; that isn't necessarily *this* host.
52 *
53 * The OpenBSD DLT_LOOP packet header is the same, except that the integer
54 * is in network byte order.
55 */
56 #define NULL_HDRLEN 4
57
58
59 /*
60 * Byte-swap a 32-bit number.
61 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
62 * big-endian platforms.)
63 */
64 #define SWAPLONG(y) \
65 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
66
67 static inline void
null_hdr_print(u_int family,u_int length)68 null_hdr_print(u_int family, u_int length)
69 {
70 if (!qflag) {
71 (void)printf("AF %s (%u)",
72 tok2str(bsd_af_values,"Unknown",family),family);
73 } else {
74 (void)printf("%s",
75 tok2str(bsd_af_values,"Unknown AF %u",family));
76 }
77
78 (void)printf(", length %u: ", length);
79 }
80
81 /*
82 * This is the top level routine of the printer. 'p' points
83 * to the ether header of the packet, 'h->ts' is the timestamp,
84 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
85 * is the number of bytes actually captured.
86 */
87 u_int
null_if_print(const struct pcap_pkthdr * h,const u_char * p)88 null_if_print(const struct pcap_pkthdr *h, const u_char *p)
89 {
90 u_int length = h->len;
91 u_int caplen = h->caplen;
92 u_int family;
93
94 if (caplen < NULL_HDRLEN) {
95 printf("[|null]");
96 return (NULL_HDRLEN);
97 }
98
99 memcpy((char *)&family, (char *)p, sizeof(family));
100
101 /*
102 * This isn't necessarily in our host byte order; if this is
103 * a DLT_LOOP capture, it's in network byte order, and if
104 * this is a DLT_NULL capture from a machine with the opposite
105 * byte-order, it's in the opposite byte order from ours.
106 *
107 * If the upper 16 bits aren't all zero, assume it's byte-swapped.
108 */
109 if ((family & 0xFFFF0000) != 0)
110 family = SWAPLONG(family);
111
112 if (eflag)
113 null_hdr_print(family, length);
114
115 length -= NULL_HDRLEN;
116 caplen -= NULL_HDRLEN;
117 p += NULL_HDRLEN;
118
119 switch (family) {
120
121 case BSD_AFNUM_INET:
122 ip_print(gndo, p, length);
123 break;
124
125 #ifdef INET6
126 case BSD_AFNUM_INET6_BSD:
127 case BSD_AFNUM_INET6_FREEBSD:
128 case BSD_AFNUM_INET6_DARWIN:
129 ip6_print(p, length);
130 break;
131 #endif
132
133 case BSD_AFNUM_ISO:
134 isoclns_print(p, length, caplen);
135 break;
136
137 case BSD_AFNUM_APPLETALK:
138 atalk_print(p, length);
139 break;
140
141 case BSD_AFNUM_IPX:
142 ipx_print(p, length);
143 break;
144
145 default:
146 /* unknown AF_ value */
147 if (!eflag)
148 null_hdr_print(family, length + NULL_HDRLEN);
149 if (!suppress_default_print)
150 default_print(p, caplen);
151 }
152
153 return (NULL_HDRLEN);
154 }
155
156 /*
157 * Local Variables:
158 * c-style: whitesmith
159 * c-basic-offset: 8
160 * End:
161 */
162