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 * $FreeBSD$ 22 */ 23 24 #ifndef lint 25 static const char rcsid[] _U_ = 26 "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.53.2.4 2007/02/26 13:31:33 hannes Exp $ (LBL)"; 27 #endif 28 29 #ifdef HAVE_CONFIG_H 30 #include "config.h" 31 #endif 32 33 #include <tcpdump-stdinc.h> 34 35 #include <pcap.h> 36 #include <stdio.h> 37 #include <string.h> 38 39 #include "interface.h" 40 #include "addrtoname.h" 41 #include "af.h" 42 43 #include "ip.h" 44 #ifdef INET6 45 #include "ip6.h" 46 #endif 47 48 /* 49 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order 50 * 32-bit integer that specifies the family, e.g. AF_INET. 51 * 52 * Note here that "host" refers to the host on which the packets were 53 * captured; that isn't necessarily *this* host. 54 * 55 * The OpenBSD DLT_LOOP packet header is the same, except that the integer 56 * is in network byte order. 57 */ 58 #define NULL_HDRLEN 4 59 60 61 /* 62 * Byte-swap a 32-bit number. 63 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 64 * big-endian platforms.) 65 */ 66 #define SWAPLONG(y) \ 67 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 68 69 static inline void 70 null_hdr_print(u_int family, u_int length) 71 { 72 if (!qflag) { 73 (void)printf("AF %s (%u)", 74 tok2str(bsd_af_values,"Unknown",family),family); 75 } else { 76 (void)printf("%s", 77 tok2str(bsd_af_values,"Unknown AF %u",family)); 78 } 79 80 (void)printf(", length %u: ", length); 81 } 82 83 /* 84 * This is the top level routine of the printer. 'p' points 85 * to the ether header of the packet, 'h->ts' is the timestamp, 86 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 87 * is the number of bytes actually captured. 88 */ 89 u_int 90 null_if_print(const struct pcap_pkthdr *h, const u_char *p) 91 { 92 u_int length = h->len; 93 u_int caplen = h->caplen; 94 u_int family; 95 96 if (caplen < NULL_HDRLEN) { 97 printf("[|null]"); 98 return (NULL_HDRLEN); 99 } 100 101 memcpy((char *)&family, (char *)p, sizeof(family)); 102 103 /* 104 * This isn't necessarily in our host byte order; if this is 105 * a DLT_LOOP capture, it's in network byte order, and if 106 * this is a DLT_NULL capture from a machine with the opposite 107 * byte-order, it's in the opposite byte order from ours. 108 * 109 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 110 */ 111 if ((family & 0xFFFF0000) != 0) 112 family = SWAPLONG(family); 113 114 if (eflag) 115 null_hdr_print(family, length); 116 117 length -= NULL_HDRLEN; 118 caplen -= NULL_HDRLEN; 119 p += NULL_HDRLEN; 120 121 switch (family) { 122 123 case BSD_AFNUM_INET: 124 ip_print(gndo, p, length); 125 break; 126 127 #ifdef INET6 128 case BSD_AFNUM_INET6_BSD: 129 case BSD_AFNUM_INET6_FREEBSD: 130 case BSD_AFNUM_INET6_DARWIN: 131 ip6_print(p, length); 132 break; 133 #endif 134 135 case BSD_AFNUM_ISO: 136 isoclns_print(p, length, caplen); 137 break; 138 139 case BSD_AFNUM_APPLETALK: 140 atalk_print(p, length); 141 break; 142 143 case BSD_AFNUM_IPX: 144 ipx_print(p, length); 145 break; 146 147 default: 148 /* unknown AF_ value */ 149 if (!eflag) 150 null_hdr_print(family, length + NULL_HDRLEN); 151 if (!suppress_default_print) 152 default_print(p, caplen); 153 } 154 155 return (NULL_HDRLEN); 156 } 157 158 /* 159 * Local Variables: 160 * c-style: whitesmith 161 * c-basic-offset: 8 162 * End: 163 */ 164