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 #define NETDISSECT_REWORKED
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27
28 #include <string.h>
29
30 #include <tcpdump-stdinc.h>
31
32 #include "interface.h"
33 #include "addrtoname.h"
34
35 #define RFC1483LLC_LEN 8
36
37 static const unsigned char rfcllc[] = {
38 0xaa, /* DSAP: non-ISO */
39 0xaa, /* SSAP: non-ISO */
40 0x03, /* Ctrl: Unnumbered Information Command PDU */
41 0x00, /* OUI: EtherType */
42 0x00,
43 0x00 };
44
45 static inline void
cip_print(netdissect_options * ndo,int length)46 cip_print(netdissect_options *ndo, int length)
47 {
48 /*
49 * There is no MAC-layer header, so just print the length.
50 */
51 ND_PRINT((ndo, "%d: ", length));
52 }
53
54 /*
55 * This is the top level routine of the printer. 'p' points
56 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
57 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
58 * is the number of bytes actually captured.
59 */
60 u_int
cip_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)61 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
62 {
63 u_int caplen = h->caplen;
64 u_int length = h->len;
65 u_short extracted_ethertype;
66
67 if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
68 ND_PRINT((ndo, "[|cip]"));
69 return (0);
70 }
71
72 if (ndo->ndo_eflag)
73 cip_print(ndo, length);
74
75 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
76 /*
77 * LLC header is present. Try to print it & higher layers.
78 */
79 if (llc_print(ndo, p, length, caplen, NULL, NULL,
80 &extracted_ethertype) == 0) {
81 /* ether_type not known, print raw packet */
82 if (!ndo->ndo_eflag)
83 cip_print(ndo, length);
84 if (extracted_ethertype) {
85 ND_PRINT((ndo, "(LLC %s) ",
86 etherproto_string(htons(extracted_ethertype))));
87 }
88 if (!ndo->ndo_suppress_default_print)
89 ND_DEFAULTPRINT(p, caplen);
90 }
91 } else {
92 /*
93 * LLC header is absent; treat it as just IP.
94 */
95 ip_print(ndo, p, length);
96 }
97
98 return (0);
99 }
100
101
102 /*
103 * Local Variables:
104 * c-style: whitesmith
105 * c-basic-offset: 8
106 * End:
107 */
108