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 #include "netdissect.h"
31 #include "extract.h"
32
33 #ifdef DLT_PKTAP
34
35 /*
36 * XXX - these are little-endian in the captures I've seen, but Apple
37 * no longer make any big-endian machines (Macs use x86, iOS machines
38 * use ARM and run it little-endian), so that might be by definition
39 * or they might be host-endian.
40 *
41 * If a big-endian PKTAP file ever shows up, and it comes from a
42 * big-endian machine, presumably these are host-endian, and we need
43 * to just fetch the fields directly in tcpdump but byte-swap them
44 * to host byte order in libpcap.
45 */
46 typedef struct pktap_header {
47 uint32_t pkt_len; /* length of pktap header */
48 uint32_t pkt_rectype; /* type of record */
49 uint32_t pkt_dlt; /* DLT type of this packet */
50 char pkt_ifname[24]; /* interface name */
51 uint32_t pkt_flags;
52 uint32_t pkt_pfamily; /* "protocol family" */
53 uint32_t pkt_llhdrlen; /* link-layer header length? */
54 uint32_t pkt_lltrlrlen; /* link-layer trailer length? */
55 uint32_t pkt_pid; /* process ID */
56 char pkt_cmdname[20]; /* command name */
57 uint32_t pkt_svc_class; /* "service class" */
58 uint16_t pkt_iftype; /* "interface type" */
59 uint16_t pkt_ifunit; /* unit number of interface? */
60 uint32_t pkt_epid; /* "effective process ID" */
61 char pkt_ecmdname[20]; /* "effective command name" */
62 } pktap_header_t;
63
64 /*
65 * Record types.
66 */
67 #define PKT_REC_NONE 0 /* nothing follows the header */
68 #define PKT_REC_PACKET 1 /* a packet follows the header */
69
70 static inline void
pktap_header_print(netdissect_options * ndo,const u_char * bp,u_int length)71 pktap_header_print(netdissect_options *ndo, const u_char *bp, u_int length)
72 {
73 const pktap_header_t *hdr;
74 uint32_t dlt, hdrlen;
75 const char *dltname;
76
77 hdr = (const pktap_header_t *)bp;
78
79 dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
80 hdrlen = EXTRACT_LE_32BITS(&hdr->pkt_len);
81 dltname = pcap_datalink_val_to_name(dlt);
82 if (!ndo->ndo_qflag) {
83 ND_PRINT((ndo,"DLT %s (%d) len %d",
84 (dltname != NULL ? dltname : "UNKNOWN"), dlt, hdrlen));
85 } else {
86 ND_PRINT((ndo,"%s", (dltname != NULL ? dltname : "UNKNOWN")));
87 }
88
89 ND_PRINT((ndo, ", length %u: ", length));
90 }
91
92 /*
93 * This is the top level routine of the printer. 'p' points
94 * to the ether header of the packet, 'h->ts' is the timestamp,
95 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
96 * is the number of bytes actually captured.
97 */
98 u_int
pktap_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)99 pktap_if_print(netdissect_options *ndo,
100 const struct pcap_pkthdr *h, const u_char *p)
101 {
102 uint32_t dlt, hdrlen, rectype;
103 u_int caplen = h->caplen;
104 u_int length = h->len;
105 if_printer printer;
106 const pktap_header_t *hdr;
107
108 if (caplen < sizeof(pktap_header_t) || length < sizeof(pktap_header_t)) {
109 ND_PRINT((ndo, "[|pktap]"));
110 return (0);
111 }
112 hdr = (const pktap_header_t *)p;
113 dlt = EXTRACT_LE_32BITS(&hdr->pkt_dlt);
114 hdrlen = EXTRACT_LE_32BITS(&hdr->pkt_len);
115 if (hdrlen < sizeof(pktap_header_t)) {
116 /*
117 * Claimed header length < structure length.
118 * XXX - does this just mean some fields aren't
119 * being supplied, or is it truly an error (i.e.,
120 * is the length supplied so that the header can
121 * be expanded in the future)?
122 */
123 ND_PRINT((ndo, "[|pktap]"));
124 return (0);
125 }
126 if (caplen < hdrlen || length < hdrlen) {
127 ND_PRINT((ndo, "[|pktap]"));
128 return (hdrlen);
129 }
130
131 if (ndo->ndo_eflag)
132 pktap_header_print(ndo, p, length);
133
134 length -= hdrlen;
135 caplen -= hdrlen;
136 p += hdrlen;
137
138 rectype = EXTRACT_LE_32BITS(&hdr->pkt_rectype);
139 switch (rectype) {
140
141 case PKT_REC_NONE:
142 ND_PRINT((ndo, "no data"));
143 break;
144
145 case PKT_REC_PACKET:
146 if ((printer = lookup_printer(dlt)) != NULL) {
147 hdrlen += printer(ndo, h, p);
148 } else {
149 if (!ndo->ndo_eflag)
150 pktap_header_print(ndo, (const 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