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 /* \summary: Classical-IP over ATM printer */
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include <string.h>
30
31 #include <netdissect-stdinc.h>
32
33 #include "netdissect.h"
34 #include "addrtoname.h"
35
36 static const unsigned char rfcllc[] = {
37 0xaa, /* DSAP: non-ISO */
38 0xaa, /* SSAP: non-ISO */
39 0x03, /* Ctrl: Unnumbered Information Command PDU */
40 0x00, /* OUI: EtherType */
41 0x00,
42 0x00 };
43
44 static inline void
cip_print(netdissect_options * ndo,u_int length)45 cip_print(netdissect_options *ndo, u_int length)
46 {
47 /*
48 * There is no MAC-layer header, so just print the length.
49 */
50 ND_PRINT((ndo, "%u: ", length));
51 }
52
53 /*
54 * This is the top level routine of the printer. 'p' points
55 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
56 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
57 * is the number of bytes actually captured.
58 */
59 u_int
cip_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)60 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
61 {
62 u_int caplen = h->caplen;
63 u_int length = h->len;
64 size_t cmplen;
65 int llc_hdrlen;
66
67 cmplen = sizeof(rfcllc);
68 if (cmplen > caplen)
69 cmplen = caplen;
70 if (cmplen > length)
71 cmplen = length;
72
73 if (ndo->ndo_eflag)
74 cip_print(ndo, length);
75
76 if (cmplen == 0) {
77 ND_PRINT((ndo, "[|cip]"));
78 return 0;
79 }
80 if (memcmp(rfcllc, p, cmplen) == 0) {
81 /*
82 * LLC header is present. Try to print it & higher layers.
83 */
84 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
85 if (llc_hdrlen < 0) {
86 /* packet type not known, print raw packet */
87 if (!ndo->ndo_suppress_default_print)
88 ND_DEFAULTPRINT(p, caplen);
89 llc_hdrlen = -llc_hdrlen;
90 }
91 } else {
92 /*
93 * LLC header is absent; treat it as just IP.
94 */
95 llc_hdrlen = 0;
96 ip_print(ndo, p, length);
97 }
98
99 return (llc_hdrlen);
100 }
101
102
103 /*
104 * Local Variables:
105 * c-style: whitesmith
106 * c-basic-offset: 8
107 * End:
108 */
109