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 1.57 2006-03-23 14:58:44 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 40 #include "ip.h" 41 #ifdef INET6 42 #include "ip6.h" 43 #endif 44 #include "af.h" 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 * Byte-swap a 32-bit number. 60 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 61 * big-endian platforms.) 62 */ 63 #define SWAPLONG(y) \ 64 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 65 66 static inline void 67 null_hdr_print(u_int family, u_int length) 68 { 69 if (!qflag) { 70 (void)printf("AF %s (%u)", 71 tok2str(bsd_af_values,"Unknown",family),family); 72 } else { 73 (void)printf("%s", 74 tok2str(bsd_af_values,"Unknown AF %u",family)); 75 } 76 77 (void)printf(", length %u: ", length); 78 } 79 80 /* 81 * This is the top level routine of the printer. 'p' points 82 * to the ether header of the packet, 'h->ts' is the timestamp, 83 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 84 * is the number of bytes actually captured. 85 */ 86 u_int 87 null_if_print(const struct pcap_pkthdr *h, const u_char *p) 88 { 89 u_int length = h->len; 90 u_int caplen = h->caplen; 91 u_int family; 92 93 if (caplen < NULL_HDRLEN) { 94 printf("[|null]"); 95 return (NULL_HDRLEN); 96 } 97 98 memcpy((char *)&family, (char *)p, sizeof(family)); 99 100 /* 101 * This isn't necessarily in our host byte order; if this is 102 * a DLT_LOOP capture, it's in network byte order, and if 103 * this is a DLT_NULL capture from a machine with the opposite 104 * byte-order, it's in the opposite byte order from ours. 105 * 106 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 107 */ 108 if ((family & 0xFFFF0000) != 0) 109 family = SWAPLONG(family); 110 111 if (eflag) 112 null_hdr_print(family, length); 113 114 length -= NULL_HDRLEN; 115 caplen -= NULL_HDRLEN; 116 p += NULL_HDRLEN; 117 118 switch (family) { 119 120 case BSD_AFNUM_INET: 121 ip_print(gndo, p, length); 122 break; 123 124 #ifdef INET6 125 case BSD_AFNUM_INET6_BSD: 126 case BSD_AFNUM_INET6_FREEBSD: 127 case BSD_AFNUM_INET6_DARWIN: 128 ip6_print(p, length); 129 break; 130 #endif 131 132 case BSD_AFNUM_ISO: 133 isoclns_print(p, length, caplen); 134 break; 135 136 case BSD_AFNUM_APPLETALK: 137 atalk_print(p, length); 138 break; 139 140 case BSD_AFNUM_IPX: 141 ipx_print(p, length); 142 break; 143 144 default: 145 /* unknown AF_ value */ 146 if (!eflag) 147 null_hdr_print(family, length + NULL_HDRLEN); 148 if (!suppress_default_print) 149 default_print(p, caplen); 150 } 151 152 return (NULL_HDRLEN); 153 } 154 155 /* 156 * Local Variables: 157 * c-style: whitesmith 158 * c-basic-offset: 8 159 * End: 160 */ 161