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 #include <sys/cdefs.h> 23 #ifndef lint 24 __RCSID("$NetBSD: print-pktap.c,v 1.7 2024/09/02 16:15:32 christos Exp $"); 25 #endif 26 27 /* \summary: Apple's DLT_PKTAP printer */ 28 29 #include <config.h> 30 31 #include "netdissect-stdinc.h" 32 33 #define ND_LONGJMP_FROM_TCHECK 34 #include "netdissect.h" 35 #include "extract.h" 36 37 #ifdef DLT_PKTAP 38 39 /* 40 * XXX - these are little-endian in the captures I've seen, but Apple 41 * no longer make any big-endian machines (Macs use x86, iOS machines 42 * use ARM and run it little-endian), so that might be by definition 43 * or they might be host-endian. 44 * 45 * If a big-endian PKTAP file ever shows up, and it comes from a 46 * big-endian machine, presumably these are host-endian, and we need 47 * to just fetch the fields directly in tcpdump but byte-swap them 48 * to host byte order in libpcap. 49 */ 50 typedef struct pktap_header { 51 nd_uint32_t pkt_len; /* length of pktap header */ 52 nd_uint32_t pkt_rectype; /* type of record */ 53 nd_uint32_t pkt_dlt; /* DLT type of this packet */ 54 char pkt_ifname[24]; /* interface name */ 55 nd_uint32_t pkt_flags; 56 nd_uint32_t pkt_pfamily; /* "protocol family" */ 57 nd_uint32_t pkt_llhdrlen; /* link-layer header length? */ 58 nd_uint32_t pkt_lltrlrlen; /* link-layer trailer length? */ 59 nd_uint32_t pkt_pid; /* process ID */ 60 char pkt_cmdname[20]; /* command name */ 61 nd_uint32_t pkt_svc_class; /* "service class" */ 62 nd_uint16_t pkt_iftype; /* "interface type" */ 63 nd_uint16_t pkt_ifunit; /* unit number of interface? */ 64 nd_uint32_t pkt_epid; /* "effective process ID" */ 65 char pkt_ecmdname[20]; /* "effective command name" */ 66 } pktap_header_t; 67 68 /* 69 * Record types. 70 */ 71 #define PKT_REC_NONE 0 /* nothing follows the header */ 72 #define PKT_REC_PACKET 1 /* a packet follows the header */ 73 74 static void 75 pktap_header_print(netdissect_options *ndo, const u_char *bp, u_int length) 76 { 77 const pktap_header_t *hdr; 78 uint32_t dlt, hdrlen; 79 const char *dltname; 80 81 hdr = (const pktap_header_t *)bp; 82 83 dlt = GET_LE_U_4(hdr->pkt_dlt); 84 hdrlen = GET_LE_U_4(hdr->pkt_len); 85 dltname = pcap_datalink_val_to_name(dlt); 86 if (!ndo->ndo_qflag) { 87 ND_PRINT("DLT %s (%u) len %u", 88 (dltname != NULL ? dltname : "UNKNOWN"), dlt, hdrlen); 89 } else { 90 ND_PRINT("%s", (dltname != NULL ? dltname : "UNKNOWN")); 91 } 92 93 ND_PRINT(", length %u: ", length); 94 } 95 96 /* 97 * This is the top level routine of the printer. 'p' points 98 * to the ether header of the packet, 'h->ts' is the timestamp, 99 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 100 * is the number of bytes actually captured. 101 */ 102 void 103 pktap_if_print(netdissect_options *ndo, 104 const struct pcap_pkthdr *h, const u_char *p) 105 { 106 uint32_t dlt, hdrlen, rectype; 107 u_int caplen = h->caplen; 108 u_int length = h->len; 109 if_printer printer; 110 const pktap_header_t *hdr; 111 struct pcap_pkthdr nhdr; 112 113 ndo->ndo_protocol = "pktap"; 114 if (length < sizeof(pktap_header_t)) { 115 ND_PRINT(" (packet too short, %u < %zu)", 116 length, sizeof(pktap_header_t)); 117 goto invalid; 118 } 119 hdr = (const pktap_header_t *)p; 120 dlt = GET_LE_U_4(hdr->pkt_dlt); 121 hdrlen = GET_LE_U_4(hdr->pkt_len); 122 if (hdrlen < sizeof(pktap_header_t)) { 123 /* 124 * Claimed header length < structure length. 125 * XXX - does this just mean some fields aren't 126 * being supplied, or is it truly an error (i.e., 127 * is the length supplied so that the header can 128 * be expanded in the future)? 129 */ 130 ND_PRINT(" (pkt_len too small, %u < %zu)", 131 hdrlen, sizeof(pktap_header_t)); 132 goto invalid; 133 } 134 if (hdrlen > length) { 135 ND_PRINT(" (pkt_len too big, %u > %u)", 136 hdrlen, length); 137 goto invalid; 138 } 139 ND_TCHECK_LEN(p, hdrlen); 140 141 if (ndo->ndo_eflag) 142 pktap_header_print(ndo, p, length); 143 144 length -= hdrlen; 145 caplen -= hdrlen; 146 p += hdrlen; 147 148 rectype = GET_LE_U_4(hdr->pkt_rectype); 149 switch (rectype) { 150 151 case PKT_REC_NONE: 152 ND_PRINT("no data"); 153 break; 154 155 case PKT_REC_PACKET: 156 printer = lookup_printer(dlt); 157 if (printer != NULL) { 158 nhdr = *h; 159 nhdr.caplen = caplen; 160 nhdr.len = length; 161 printer(ndo, &nhdr, p); 162 hdrlen += ndo->ndo_ll_hdr_len; 163 } else { 164 if (!ndo->ndo_eflag) 165 pktap_header_print(ndo, (const u_char *)hdr, 166 length + hdrlen); 167 168 if (!ndo->ndo_suppress_default_print) 169 ND_DEFAULTPRINT(p, caplen); 170 } 171 break; 172 } 173 174 ndo->ndo_ll_hdr_len += hdrlen; 175 return; 176 177 invalid: 178 nd_print_invalid(ndo); 179 } 180 #endif /* DLT_PKTAP */ 181
Indexes created Fri Oct 02 00:25:19 UTC 2026