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