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 1.57 2006-03-23 14:58:44 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 42 #include "ip.h" 43 #ifdef INET6 44 #include "ip6.h" 45 #endif 46 #include "af.h" 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 * Byte-swap a 32-bit number. 62 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 63 * big-endian platforms.) 64 */ 65 #define SWAPLONG(y) \ 66 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 67 68 static inline void 69 null_hdr_print(u_int family, u_int length) 70 { 71 if (!qflag) { 72 (void)printf("AF %s (%u)", 73 tok2str(bsd_af_values,"Unknown",family),family); 74 } else { 75 (void)printf("%s", 76 tok2str(bsd_af_values,"Unknown AF %u",family)); 77 } 78 79 (void)printf(", length %u: ", length); 80 } 81 82 /* 83 * This is the top level routine of the printer. 'p' points 84 * to the ether header of the packet, 'h->ts' is the timestamp, 85 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 86 * is the number of bytes actually captured. 87 */ 88 u_int 89 null_if_print(const struct pcap_pkthdr *h, const u_char *p) 90 { 91 u_int length = h->len; 92 u_int caplen = h->caplen; 93 u_int family; 94 95 if (caplen < NULL_HDRLEN) { 96 printf("[|null]"); 97 return (NULL_HDRLEN); 98 } 99 100 memcpy((char *)&family, (char *)p, sizeof(family)); 101 102 /* 103 * This isn't necessarily in our host byte order; if this is 104 * a DLT_LOOP capture, it's in network byte order, and if 105 * this is a DLT_NULL capture from a machine with the opposite 106 * byte-order, it's in the opposite byte order from ours. 107 * 108 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 109 */ 110 if ((family & 0xFFFF0000) != 0) 111 family = SWAPLONG(family); 112 113 if (eflag) 114 null_hdr_print(family, length); 115 116 length -= NULL_HDRLEN; 117 caplen -= NULL_HDRLEN; 118 p += NULL_HDRLEN; 119 120 switch (family) { 121 122 case BSD_AFNUM_INET: 123 ip_print(gndo, p, length); 124 break; 125 126 #ifdef INET6 127 case BSD_AFNUM_INET6_BSD: 128 case BSD_AFNUM_INET6_FREEBSD: 129 case BSD_AFNUM_INET6_DARWIN: 130 ip6_print(gndo, p, length); 131 break; 132 #endif 133 134 case BSD_AFNUM_ISO: 135 isoclns_print(p, length, caplen); 136 break; 137 138 case BSD_AFNUM_APPLETALK: 139 atalk_print(p, length); 140 break; 141 142 case BSD_AFNUM_IPX: 143 ipx_print(p, length); 144 break; 145 146 default: 147 /* unknown AF_ value */ 148 if (!eflag) 149 null_hdr_print(family, length + NULL_HDRLEN); 150 if (!suppress_default_print) 151 default_print(p, caplen); 152 } 153 154 return (NULL_HDRLEN); 155 } 156 157 /* 158 * Local Variables: 159 * c-style: whitesmith 160 * c-basic-offset: 8 161 * End: 162 */ 163