xref: /freebsd/contrib/tcpdump/print-pktap.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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 #define NETDISSECT_REWORKED
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26 
27 #include <tcpdump-stdinc.h>
28 
29 #include "interface.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 	uint32_t	pkt_len;	/* length of pktap header */
47 	uint32_t	pkt_rectype;	/* type of record */
48 	uint32_t	pkt_dlt;	/* DLT type of this packet */
49 	char		pkt_ifname[24];	/* interface name */
50 	uint32_t	pkt_flags;
51 	uint32_t	pkt_pfamily;	/* "protocol family" */
52 	uint32_t	pkt_llhdrlen;	/* link-layer header length? */
53 	uint32_t	pkt_lltrlrlen;	/* link-layer trailer length? */
54 	uint32_t	pkt_pid;	/* process ID */
55 	char		pkt_cmdname[20]; /* command name */
56 	uint32_t	pkt_svc_class;	/* "service class" */
57 	uint16_t	pkt_iftype;	/* "interface type" */
58 	uint16_t	pkt_ifunit;	/* unit number of interface? */
59 	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 inline 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 
75 	hdr = (const pktap_header_t *)bp;
76 
77 	dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
78 	hdrlen = EXTRACT_LE_32BITS(&hdr->pkt_len);
79 	if (!ndo->ndo_qflag) {
80 		ND_PRINT((ndo,", DLT %s (%d) len %d",
81 			  pcap_datalink_val_to_name(dlt), dlt, hdrlen));
82         } else {
83 		ND_PRINT((ndo,", %s", pcap_datalink_val_to_name(dlt)));
84         }
85 
86 	ND_PRINT((ndo, ", length %u: ", length));
87 }
88 
89 /*
90  * This is the top level routine of the printer.  'p' points
91  * to the ether header of the packet, 'h->ts' is the timestamp,
92  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
93  * is the number of bytes actually captured.
94  */
95 u_int
96 pktap_if_print(netdissect_options *ndo,
97                const struct pcap_pkthdr *h, const u_char *p)
98 {
99 	uint32_t dlt, hdrlen, rectype;
100 	u_int caplen = h->caplen;
101 	u_int length = h->len;
102 	if_ndo_printer ndo_printer;
103         if_printer printer;
104 	pktap_header_t *hdr;
105 
106 	if (caplen < sizeof(pktap_header_t) || length < sizeof(pktap_header_t)) {
107 		ND_PRINT((ndo, "[|pktap]"));
108 		return (0);
109 	}
110 	hdr = (pktap_header_t *)p;
111 	dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
112 	hdrlen = EXTRACT_LE_32BITS(&hdr->pkt_len);
113 	if (hdrlen < sizeof(pktap_header_t)) {
114 		/*
115 		 * Claimed header length < structure length.
116 		 * XXX - does this just mean some fields aren't
117 		 * being supplied, or is it truly an error (i.e.,
118 		 * is the length supplied so that the header can
119 		 * be expanded in the future)?
120 		 */
121 		ND_PRINT((ndo, "[|pktap]"));
122 		return (0);
123 	}
124 	if (caplen < hdrlen || length < hdrlen) {
125 		ND_PRINT((ndo, "[|pktap]"));
126 		return (hdrlen);
127 	}
128 
129 	if (ndo->ndo_eflag)
130 		pktap_header_print(ndo, p, length);
131 
132 	length -= hdrlen;
133 	caplen -= hdrlen;
134 	p += hdrlen;
135 
136 	rectype = EXTRACT_LE_32BITS(&hdr->pkt_rectype);
137 	switch (rectype) {
138 
139 	case PKT_REC_NONE:
140 		ND_PRINT((ndo, "no data"));
141 		break;
142 
143 	case PKT_REC_PACKET:
144 		if ((printer = lookup_printer(dlt)) != NULL) {
145 			printer(h, p);
146 		} else if ((ndo_printer = lookup_ndo_printer(dlt)) != NULL) {
147 			ndo_printer(ndo, h, p);
148 		} else {
149 			if (!ndo->ndo_eflag)
150 				pktap_header_print(ndo, (u_char *)hdr,
151 						length + hdrlen);
152 
153 			if (!ndo->ndo_suppress_default_print)
154 				ND_DEFAULTPRINT(p, caplen);
155 		}
156 		break;
157 	}
158 
159 	return (hdrlen);
160 }
161 
162 /*
163  * Local Variables:
164  * c-style: whitesmith
165  * c-basic-offset: 8
166  * End:
167  */
168 
169 #endif /* DLT_PKTAP */
170