1 /*
2 * Marko Kiiskila carnil@cs.tut.fi
3 *
4 * Tampere University of Technology - Telecommunications Laboratory
5 *
6 * Permission to use, copy, modify and distribute this
7 * software and its documentation is hereby granted,
8 * provided that both the copyright notice and this
9 * permission notice appear in all copies of the software,
10 * derivative works or modified versions, and any portions
11 * thereof, that both notices appear in supporting
12 * documentation, and that the use of this software is
13 * acknowledged in any publications resulting from using
14 * the software.
15 *
16 * TUT ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17 * CONDITION AND DISCLAIMS ANY LIABILITY OF ANY KIND FOR
18 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS
19 * SOFTWARE.
20 *
21 */
22
23 #include <sys/cdefs.h>
24 #ifndef lint
25 __RCSID("$NetBSD: print-cip.c,v 1.4 2014/11/20 03:05:03 christos Exp $");
26 #endif
27
28 #define NETDISSECT_REWORKED
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32
33 #include <string.h>
34
35 #include <tcpdump-stdinc.h>
36
37 #include "interface.h"
38 #include "addrtoname.h"
39
40 #define RFC1483LLC_LEN 8
41
42 static const unsigned char rfcllc[] = {
43 0xaa, /* DSAP: non-ISO */
44 0xaa, /* SSAP: non-ISO */
45 0x03, /* Ctrl: Unnumbered Information Command PDU */
46 0x00, /* OUI: EtherType */
47 0x00,
48 0x00 };
49
50 static inline void
cip_print(netdissect_options * ndo,int length)51 cip_print(netdissect_options *ndo, int length)
52 {
53 /*
54 * There is no MAC-layer header, so just print the length.
55 */
56 ND_PRINT((ndo, "%d: ", length));
57 }
58
59 /*
60 * This is the top level routine of the printer. 'p' points
61 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
62 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
63 * is the number of bytes actually captured.
64 */
65 u_int
cip_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)66 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
67 {
68 u_int caplen = h->caplen;
69 u_int length = h->len;
70 u_short extracted_ethertype;
71
72 if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
73 ND_PRINT((ndo, "[|cip]"));
74 return (0);
75 }
76
77 if (ndo->ndo_eflag)
78 cip_print(ndo, length);
79
80 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
81 /*
82 * LLC header is present. Try to print it & higher layers.
83 */
84 if (llc_print(ndo, p, length, caplen, NULL, NULL,
85 &extracted_ethertype) == 0) {
86 /* ether_type not known, print raw packet */
87 if (!ndo->ndo_eflag)
88 cip_print(ndo, length);
89 if (extracted_ethertype) {
90 ND_PRINT((ndo, "(LLC %s) ",
91 etherproto_string(htons(extracted_ethertype))));
92 }
93 if (!ndo->ndo_suppress_default_print)
94 ND_DEFAULTPRINT(p, caplen);
95 }
96 } else {
97 /*
98 * LLC header is absent; treat it as just IP.
99 */
100 ip_print(ndo, p, length);
101 }
102
103 return (0);
104 }
105
106
107 /*
108 * Local Variables:
109 * c-style: whitesmith
110 * c-basic-offset: 8
111 * End:
112 */
113