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 */
47typedef 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
71static void
72pktap_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 */
99void
100pktap_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
174invalid:
175	nd_print_invalid(ndo);
176}
177#endif /* DLT_PKTAP */
178