1 /* 2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000 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: Apple's DLT_PKTAP printer */ 23 24 #ifdef HAVE_CONFIG_H 25 #include <config.h> 26 #endif 27 28 #include "netdissect-stdinc.h" 29 30 #define ND_LONGJMP_FROM_TCHECK 31 #include "netdissect.h" 32 #include "extract.h" 33 34 #ifdef DLT_PKTAP 35 36 /* 37 * XXX - these are little-endian in the captures I've seen, but Apple 38 * no longer make any big-endian machines (Macs use x86, iOS machines 39 * use ARM and run it little-endian), so that might be by definition 40 * or they might be host-endian. 41 * 42 * If a big-endian PKTAP file ever shows up, and it comes from a 43 * big-endian machine, presumably these are host-endian, and we need 44 * to just fetch the fields directly in tcpdump but byte-swap them 45 * to host byte order in libpcap. 46 */ 47 typedef struct pktap_header { 48 nd_uint32_t pkt_len; /* length of pktap header */ 49 nd_uint32_t pkt_rectype; /* type of record */ 50 nd_uint32_t pkt_dlt; /* DLT type of this packet */ 51 char pkt_ifname[24]; /* interface name */ 52 nd_uint32_t pkt_flags; 53 nd_uint32_t pkt_pfamily; /* "protocol family" */ 54 nd_uint32_t pkt_llhdrlen; /* link-layer header length? */ 55 nd_uint32_t pkt_lltrlrlen; /* link-layer trailer length? */ 56 nd_uint32_t pkt_pid; /* process ID */ 57 char pkt_cmdname[20]; /* command name */ 58 nd_uint32_t pkt_svc_class; /* "service class" */ 59 nd_uint16_t pkt_iftype; /* "interface type" */ 60 nd_uint16_t pkt_ifunit; /* unit number of interface? */ 61 nd_uint32_t pkt_epid; /* "effective process ID" */ 62 char pkt_ecmdname[20]; /* "effective command name" */ 63 } pktap_header_t; 64 65 /* 66 * Record types. 67 */ 68 #define PKT_REC_NONE 0 /* nothing follows the header */ 69 #define PKT_REC_PACKET 1 /* a packet follows the header */ 70 71 static void 72 pktap_header_print(netdissect_options *ndo, const u_char *bp, u_int length) 73 { 74 const pktap_header_t *hdr; 75 uint32_t dlt, hdrlen; 76 const char *dltname; 77 78 hdr = (const pktap_header_t *)bp; 79 80 dlt = GET_LE_U_4(hdr->pkt_dlt); 81 hdrlen = GET_LE_U_4(hdr->pkt_len); 82 dltname = pcap_datalink_val_to_name(dlt); 83 if (!ndo->ndo_qflag) { 84 ND_PRINT("DLT %s (%u) len %u", 85 (dltname != NULL ? dltname : "UNKNOWN"), dlt, hdrlen); 86 } else { 87 ND_PRINT("%s", (dltname != NULL ? dltname : "UNKNOWN")); 88 } 89 90 ND_PRINT(", length %u: ", length); 91 } 92 93 /* 94 * This is the top level routine of the printer. 'p' points 95 * to the ether header of the packet, 'h->ts' is the timestamp, 96 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 97 * is the number of bytes actually captured. 98 */ 99 void 100 pktap_if_print(netdissect_options *ndo, 101 const struct pcap_pkthdr *h, const u_char *p) 102 { 103 uint32_t dlt, hdrlen, rectype; 104 u_int caplen = h->caplen; 105 u_int length = h->len; 106 if_printer printer; 107 const pktap_header_t *hdr; 108 struct pcap_pkthdr nhdr; 109 110 ndo->ndo_protocol = "pktap"; 111 if (length < sizeof(pktap_header_t)) { 112 ND_PRINT(" (packet too short, %u < %zu)", 113 length, sizeof(pktap_header_t)); 114 goto invalid; 115 } 116 hdr = (const pktap_header_t *)p; 117 dlt = GET_LE_U_4(hdr->pkt_dlt); 118 hdrlen = GET_LE_U_4(hdr->pkt_len); 119 if (hdrlen < sizeof(pktap_header_t)) { 120 /* 121 * Claimed header length < structure length. 122 * XXX - does this just mean some fields aren't 123 * being supplied, or is it truly an error (i.e., 124 * is the length supplied so that the header can 125 * be expanded in the future)? 126 */ 127 ND_PRINT(" (pkt_len too small, %u < %zu)", 128 hdrlen, sizeof(pktap_header_t)); 129 goto invalid; 130 } 131 if (hdrlen > length) { 132 ND_PRINT(" (pkt_len too big, %u > %u)", 133 hdrlen, length); 134 goto invalid; 135 } 136 ND_TCHECK_LEN(p, hdrlen); 137 138 if (ndo->ndo_eflag) 139 pktap_header_print(ndo, p, length); 140 141 length -= hdrlen; 142 caplen -= hdrlen; 143 p += hdrlen; 144 145 rectype = GET_LE_U_4(hdr->pkt_rectype); 146 switch (rectype) { 147 148 case PKT_REC_NONE: 149 ND_PRINT("no data"); 150 break; 151 152 case PKT_REC_PACKET: 153 printer = lookup_printer(dlt); 154 if (printer != NULL) { 155 nhdr = *h; 156 nhdr.caplen = caplen; 157 nhdr.len = length; 158 printer(ndo, &nhdr, p); 159 hdrlen += ndo->ndo_ll_hdr_len; 160 } else { 161 if (!ndo->ndo_eflag) 162 pktap_header_print(ndo, (const u_char *)hdr, 163 length + hdrlen); 164 165 if (!ndo->ndo_suppress_default_print) 166 ND_DEFAULTPRINT(p, caplen); 167 } 168 break; 169 } 170 171 ndo->ndo_ll_hdr_len += hdrlen; 172 return; 173 174 invalid: 175 nd_print_invalid(ndo); 176 } 177 #endif /* DLT_PKTAP */ 178