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 __RCSID("$NetBSD: print-null.c,v 1.5 2015/03/31 21:59:35 christos Exp $"); 25 #endif 26 27 #define NETDISSECT_REWORKED 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #include <tcpdump-stdinc.h> 33 34 #include <string.h> 35 36 #include "interface.h" 37 #include "af.h" 38 39 /* 40 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order 41 * 32-bit integer that specifies the family, e.g. AF_INET. 42 * 43 * Note here that "host" refers to the host on which the packets were 44 * captured; that isn't necessarily *this* host. 45 * 46 * The OpenBSD DLT_LOOP packet header is the same, except that the integer 47 * is in network byte order. 48 */ 49 #define NULL_HDRLEN 4 50 51 /* 52 * Byte-swap a 32-bit number. 53 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 54 * big-endian platforms.) 55 */ 56 #define SWAPLONG(y) \ 57 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 58 59 static inline void 60 null_hdr_print(netdissect_options *ndo, u_int family, u_int length) 61 { 62 if (!ndo->ndo_qflag) { 63 ND_PRINT((ndo, "AF %s (%u)", 64 tok2str(bsd_af_values,"Unknown",family),family)); 65 } else { 66 ND_PRINT((ndo, "%s", 67 tok2str(bsd_af_values,"Unknown AF %u",family))); 68 } 69 70 ND_PRINT((ndo, ", length %u: ", length)); 71 } 72 73 /* 74 * This is the top level routine of the printer. 'p' points 75 * to the ether header of the packet, 'h->ts' is the timestamp, 76 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 77 * is the number of bytes actually captured. 78 */ 79 u_int 80 null_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 81 { 82 u_int length = h->len; 83 u_int caplen = h->caplen; 84 u_int family; 85 86 if (caplen < NULL_HDRLEN) { 87 ND_PRINT((ndo, "[|null]")); 88 return (NULL_HDRLEN); 89 } 90 91 memcpy((char *)&family, (char *)p, sizeof(family)); 92 93 /* 94 * This isn't necessarily in our host byte order; if this is 95 * a DLT_LOOP capture, it's in network byte order, and if 96 * this is a DLT_NULL capture from a machine with the opposite 97 * byte-order, it's in the opposite byte order from ours. 98 * 99 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 100 */ 101 if ((family & 0xFFFF0000) != 0) 102 family = SWAPLONG(family); 103 104 if (ndo->ndo_eflag) 105 null_hdr_print(ndo, family, length); 106 107 length -= NULL_HDRLEN; 108 caplen -= NULL_HDRLEN; 109 p += NULL_HDRLEN; 110 111 switch (family) { 112 113 case BSD_AFNUM_INET: 114 ip_print(ndo, p, length); 115 break; 116 117 case BSD_AFNUM_INET6_BSD: 118 case BSD_AFNUM_INET6_FREEBSD: 119 case BSD_AFNUM_INET6_DARWIN: 120 ip6_print(ndo, p, length); 121 break; 122 123 case BSD_AFNUM_ISO: 124 isoclns_print(ndo, p, length, caplen); 125 break; 126 127 case BSD_AFNUM_APPLETALK: 128 atalk_print(ndo, p, length); 129 break; 130 131 case BSD_AFNUM_IPX: 132 ipx_print(ndo, p, length); 133 break; 134 135 default: 136 /* unknown AF_ value */ 137 if (!ndo->ndo_eflag) 138 null_hdr_print(ndo, family, length + NULL_HDRLEN); 139 if (!ndo->ndo_suppress_default_print) 140 ND_DEFAULTPRINT(p, caplen); 141 } 142 143 return (NULL_HDRLEN); 144 } 145 146 /* 147 * Local Variables: 148 * c-style: whitesmith 149 * c-basic-offset: 8 150 * End: 151 */ 152