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 #include <sys/cdefs.h> 23 #ifndef lint 24 #if 0 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 #else 28 __RCSID("$NetBSD: print-null.c,v 1.2 2010/12/05 05:11:30 christos Exp $"); 29 #endif 30 #endif 31 32 #ifdef HAVE_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #include <tcpdump-stdinc.h> 37 38 #include <pcap.h> 39 #include <stdio.h> 40 #include <string.h> 41 42 #include "interface.h" 43 #include "addrtoname.h" 44 45 #include "ip.h" 46 #ifdef INET6 47 #include "ip6.h" 48 #endif 49 #include "af.h" 50 51 /* 52 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order 53 * 32-bit integer that specifies the family, e.g. AF_INET. 54 * 55 * Note here that "host" refers to the host on which the packets were 56 * captured; that isn't necessarily *this* host. 57 * 58 * The OpenBSD DLT_LOOP packet header is the same, except that the integer 59 * is in network byte order. 60 */ 61 #define NULL_HDRLEN 4 62 63 /* 64 * Byte-swap a 32-bit number. 65 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 66 * big-endian platforms.) 67 */ 68 #define SWAPLONG(y) \ 69 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 70 71 static inline void 72 null_hdr_print(u_int family, u_int length) 73 { 74 if (!qflag) { 75 (void)printf("AF %s (%u)", 76 tok2str(bsd_af_values,"Unknown",family),family); 77 } else { 78 (void)printf("%s", 79 tok2str(bsd_af_values,"Unknown AF %u",family)); 80 } 81 82 (void)printf(", length %u: ", length); 83 } 84 85 /* 86 * This is the top level routine of the printer. 'p' points 87 * to the ether header of the packet, 'h->ts' is the timestamp, 88 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 89 * is the number of bytes actually captured. 90 */ 91 u_int 92 null_if_print(const struct pcap_pkthdr *h, const u_char *p) 93 { 94 u_int length = h->len; 95 u_int caplen = h->caplen; 96 u_int family; 97 98 if (caplen < NULL_HDRLEN) { 99 printf("[|null]"); 100 return (NULL_HDRLEN); 101 } 102 103 memcpy((char *)&family, (char *)p, sizeof(family)); 104 105 /* 106 * This isn't necessarily in our host byte order; if this is 107 * a DLT_LOOP capture, it's in network byte order, and if 108 * this is a DLT_NULL capture from a machine with the opposite 109 * byte-order, it's in the opposite byte order from ours. 110 * 111 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 112 */ 113 if ((family & 0xFFFF0000) != 0) 114 family = SWAPLONG(family); 115 116 if (eflag) 117 null_hdr_print(family, length); 118 119 length -= NULL_HDRLEN; 120 caplen -= NULL_HDRLEN; 121 p += NULL_HDRLEN; 122 123 switch (family) { 124 125 case BSD_AFNUM_INET: 126 ip_print(gndo, p, length); 127 break; 128 129 #ifdef INET6 130 case BSD_AFNUM_INET6_BSD: 131 case BSD_AFNUM_INET6_FREEBSD: 132 case BSD_AFNUM_INET6_DARWIN: 133 ip6_print(p, length); 134 break; 135 #endif 136 137 case BSD_AFNUM_ISO: 138 isoclns_print(p, length, caplen); 139 break; 140 141 case BSD_AFNUM_APPLETALK: 142 atalk_print(p, length); 143 break; 144 145 case BSD_AFNUM_IPX: 146 ipx_print(p, length); 147 break; 148 149 default: 150 /* unknown AF_ value */ 151 if (!eflag) 152 null_hdr_print(family, length + NULL_HDRLEN); 153 if (!suppress_default_print) 154 default_print(p, caplen); 155 } 156 157 return (NULL_HDRLEN); 158 } 159 160 /* 161 * Local Variables: 162 * c-style: whitesmith 163 * c-basic-offset: 8 164 * End: 165 */ 166