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 1.53.2.2 2005/05/19 07:26:18 guy 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 42 #include "ip.h" 43 #ifdef INET6 44 #include "ip6.h" 45 #endif 46 47 /* 48 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order 49 * 32-bit integer that specifies the family, e.g. AF_INET. 50 * 51 * Note here that "host" refers to the host on which the packets were 52 * captured; that isn't necessarily *this* host. 53 * 54 * The OpenBSD DLT_LOOP packet header is the same, except that the integer 55 * is in network byte order. 56 */ 57 #define NULL_HDRLEN 4 58 59 /* 60 * BSD AF_ values. 61 * 62 * Unfortunately, the BSDs don't all use the same value for AF_INET6, 63 * so, because we want to be able to read captures from all of the BSDs, 64 * we check for all of them. 65 */ 66 #define BSD_AF_INET 2 67 #define BSD_AF_NS 6 /* XEROX NS protocols */ 68 #define BSD_AF_ISO 7 69 #define BSD_AF_APPLETALK 16 70 #define BSD_AF_IPX 23 71 #define BSD_AF_INET6_BSD 24 /* OpenBSD (and probably NetBSD), BSD/OS */ 72 #define BSD_AF_INET6_FREEBSD 28 73 #define BSD_AF_INET6_DARWIN 30 74 75 const struct tok bsd_af_values[] = { 76 { BSD_AF_INET, "IPv4" }, 77 { BSD_AF_NS, "NS" }, 78 { BSD_AF_ISO, "ISO" }, 79 { BSD_AF_APPLETALK, "Appletalk" }, 80 { BSD_AF_IPX, "IPX" }, 81 { BSD_AF_INET6_BSD, "IPv6" }, 82 { BSD_AF_INET6_FREEBSD, "IPv6" }, 83 { BSD_AF_INET6_DARWIN, "IPv6" }, 84 { 0, NULL} 85 }; 86 87 88 /* 89 * Byte-swap a 32-bit number. 90 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 91 * big-endian platforms.) 92 */ 93 #define SWAPLONG(y) \ 94 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 95 96 static inline void 97 null_hdr_print(u_int family, u_int length) 98 { 99 if (!qflag) { 100 (void)printf("AF %s (%u)", 101 tok2str(bsd_af_values,"Unknown",family),family); 102 } else { 103 (void)printf("%s", 104 tok2str(bsd_af_values,"Unknown AF %u",family)); 105 } 106 107 (void)printf(", length %u: ", length); 108 } 109 110 /* 111 * This is the top level routine of the printer. 'p' points 112 * to the ether header of the packet, 'h->ts' is the timestamp, 113 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 114 * is the number of bytes actually captured. 115 */ 116 u_int 117 null_if_print(const struct pcap_pkthdr *h, const u_char *p) 118 { 119 u_int length = h->len; 120 u_int caplen = h->caplen; 121 u_int family; 122 123 if (caplen < NULL_HDRLEN) { 124 printf("[|null]"); 125 return (NULL_HDRLEN); 126 } 127 128 memcpy((char *)&family, (char *)p, sizeof(family)); 129 130 /* 131 * This isn't necessarily in our host byte order; if this is 132 * a DLT_LOOP capture, it's in network byte order, and if 133 * this is a DLT_NULL capture from a machine with the opposite 134 * byte-order, it's in the opposite byte order from ours. 135 * 136 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 137 */ 138 if ((family & 0xFFFF0000) != 0) 139 family = SWAPLONG(family); 140 141 if (eflag) 142 null_hdr_print(family, length); 143 144 length -= NULL_HDRLEN; 145 caplen -= NULL_HDRLEN; 146 p += NULL_HDRLEN; 147 148 switch (family) { 149 150 case BSD_AF_INET: 151 ip_print(gndo, p, length); 152 break; 153 154 #ifdef INET6 155 case BSD_AF_INET6_BSD: 156 case BSD_AF_INET6_FREEBSD: 157 case BSD_AF_INET6_DARWIN: 158 ip6_print(p, length); 159 break; 160 #endif 161 162 case BSD_AF_ISO: 163 isoclns_print(p, length, caplen); 164 break; 165 166 case BSD_AF_APPLETALK: 167 atalk_print(p, length); 168 break; 169 170 case BSD_AF_IPX: 171 ipx_print(p, length); 172 break; 173 174 default: 175 /* unknown AF_ value */ 176 if (!eflag) 177 null_hdr_print(family, length + NULL_HDRLEN); 178 if (!xflag && !qflag) 179 default_print(p, caplen); 180 } 181 182 return (NULL_HDRLEN); 183 } 184 185 /* 186 * Local Variables: 187 * c-style: whitesmith 188 * c-basic-offset: 8 189 * End: 190 */ 191