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 1.6 2017/01/24 23:29:14 christos Exp $"); 25 #endif 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #include <netdissect-stdinc.h> 32 33 #include <string.h> 34 35 #include "netdissect.h" 36 #include "af.h" 37 38 /* 39 * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order 40 * 32-bit integer that specifies the family, e.g. AF_INET. 41 * 42 * Note here that "host" refers to the host on which the packets were 43 * captured; that isn't necessarily *this* host. 44 * 45 * The OpenBSD DLT_LOOP packet header is the same, except that the integer 46 * is in network byte order. 47 */ 48 #define NULL_HDRLEN 4 49 50 /* 51 * Byte-swap a 32-bit number. 52 * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on 53 * big-endian platforms.) 54 */ 55 #define SWAPLONG(y) \ 56 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) 57 58 static inline void 59 null_hdr_print(netdissect_options *ndo, u_int family, u_int length) 60 { 61 if (!ndo->ndo_qflag) { 62 ND_PRINT((ndo, "AF %s (%u)", 63 tok2str(bsd_af_values,"Unknown",family),family)); 64 } else { 65 ND_PRINT((ndo, "%s", 66 tok2str(bsd_af_values,"Unknown AF %u",family))); 67 } 68 69 ND_PRINT((ndo, ", length %u: ", length)); 70 } 71 72 /* 73 * This is the top level routine of the printer. 'p' points 74 * to the ether header of the packet, 'h->ts' is the timestamp, 75 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 76 * is the number of bytes actually captured. 77 */ 78 u_int 79 null_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 80 { 81 u_int length = h->len; 82 u_int caplen = h->caplen; 83 u_int family; 84 85 if (caplen < NULL_HDRLEN) { 86 ND_PRINT((ndo, "[|null]")); 87 return (NULL_HDRLEN); 88 } 89 90 memcpy((char *)&family, (const char *)p, sizeof(family)); 91 92 /* 93 * This isn't necessarily in our host byte order; if this is 94 * a DLT_LOOP capture, it's in network byte order, and if 95 * this is a DLT_NULL capture from a machine with the opposite 96 * byte-order, it's in the opposite byte order from ours. 97 * 98 * If the upper 16 bits aren't all zero, assume it's byte-swapped. 99 */ 100 if ((family & 0xFFFF0000) != 0) 101 family = SWAPLONG(family); 102 103 if (ndo->ndo_eflag) 104 null_hdr_print(ndo, family, length); 105 106 length -= NULL_HDRLEN; 107 caplen -= NULL_HDRLEN; 108 p += NULL_HDRLEN; 109 110 switch (family) { 111 112 case BSD_AFNUM_INET: 113 ip_print(ndo, p, length); 114 break; 115 116 case BSD_AFNUM_INET6_BSD: 117 case BSD_AFNUM_INET6_FREEBSD: 118 case BSD_AFNUM_INET6_DARWIN: 119 ip6_print(ndo, p, length); 120 break; 121 122 case BSD_AFNUM_ISO: 123 isoclns_print(ndo, p, length, caplen); 124 break; 125 126 case BSD_AFNUM_APPLETALK: 127 atalk_print(ndo, p, length); 128 break; 129 130 case BSD_AFNUM_IPX: 131 ipx_print(ndo, p, length); 132 break; 133 134 default: 135 /* unknown AF_ value */ 136 if (!ndo->ndo_eflag) 137 null_hdr_print(ndo, family, length + NULL_HDRLEN); 138 if (!ndo->ndo_suppress_default_print) 139 ND_DEFAULTPRINT(p, caplen); 140 } 141 142 return (NULL_HDRLEN); 143 } 144 145 /* 146 * Local Variables: 147 * c-style: whitesmith 148 * c-basic-offset: 8 149 * End: 150 */ 151