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