1 /*
2 * Copyright (c) 2013, Petar Alilovic,
3 * Faculty of Electrical Engineering and Computing, University of Zagreb
4 * All rights reserved
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
25 * DAMAGE.
26 */
27
28 #define NETDISSECT_REWORKED
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32
33 #include <tcpdump-stdinc.h>
34
35 #include "interface.h"
36
37 #if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
38 #include <pcap/nflog.h>
39
40 static const struct tok nflog_values[] = {
41 { AF_INET, "IPv4" },
42 #ifdef INET6
43 { AF_INET6, "IPv6" },
44 #endif /*INET6*/
45 { 0, NULL }
46 };
47
48 static inline void
nflog_hdr_print(netdissect_options * ndo,const nflog_hdr_t * hdr,u_int length)49 nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
50 {
51 ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
52
53 if (!ndo->ndo_qflag) {
54 ND_PRINT((ndo,", family %s (%d)",
55 tok2str(nflog_values, "Unknown",
56 hdr->nflog_family),
57 hdr->nflog_family));
58 } else {
59 ND_PRINT((ndo,", %s",
60 tok2str(nflog_values,
61 "Unknown NFLOG (0x%02x)",
62 hdr->nflog_family)));
63 }
64
65 ND_PRINT((ndo, ", length %u: ", length));
66 }
67
68 u_int
nflog_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)69 nflog_if_print(netdissect_options *ndo,
70 const struct pcap_pkthdr *h, const u_char *p)
71 {
72 const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
73 const nflog_tlv_t *tlv;
74 uint16_t size;
75 uint16_t h_size = sizeof(nflog_hdr_t);
76 u_int caplen = h->caplen;
77 u_int length = h->len;
78
79 if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
80 ND_PRINT((ndo, "[|nflog]"));
81 return h_size;
82 }
83
84 if (!(hdr->nflog_version) == 0) {
85 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
86 return h_size;
87 }
88
89 if (ndo->ndo_eflag)
90 nflog_hdr_print(ndo, hdr, length);
91
92 p += sizeof(nflog_hdr_t);
93 length -= sizeof(nflog_hdr_t);
94 caplen -= sizeof(nflog_hdr_t);
95
96 while (length > 0) {
97 /* We have some data. Do we have enough for the TLV header? */
98 if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
99 /* No. */
100 ND_PRINT((ndo, "[|nflog]"));
101 return h_size;
102 }
103
104 tlv = (const nflog_tlv_t *) p;
105 size = tlv->tlv_length;
106 if (size % 4 != 0)
107 size += 4 - size % 4;
108
109 /* Is the TLV's length less than the minimum? */
110 if (size < sizeof(nflog_tlv_t)) {
111 /* Yes. Give up now. */
112 ND_PRINT((ndo, "[|nflog]"));
113 return h_size;
114 }
115
116 /* Do we have enough data for the full TLV? */
117 if (caplen < size || length < size) {
118 /* No. */
119 ND_PRINT((ndo, "[|nflog]"));
120 return h_size;
121 }
122
123 if (tlv->tlv_type == NFULA_PAYLOAD) {
124 /*
125 * This TLV's data is the packet payload.
126 * Skip past the TLV header, and break out
127 * of the loop so we print the packet data.
128 */
129 p += sizeof(nflog_tlv_t);
130 h_size += sizeof(nflog_tlv_t);
131 length -= sizeof(nflog_tlv_t);
132 caplen -= sizeof(nflog_tlv_t);
133 break;
134 }
135
136 p += size;
137 h_size += size;
138 length -= size;
139 caplen -= size;
140 }
141
142 switch (hdr->nflog_family) {
143
144 case AF_INET:
145 ip_print(ndo, p, length);
146 break;
147
148 #ifdef AF_INET6
149 case AF_INET6:
150 ip6_print(ndo, p, length);
151 break;
152 #endif /* AF_INET6 */
153
154 default:
155 if (!ndo->ndo_eflag)
156 nflog_hdr_print(ndo, hdr,
157 length + sizeof(nflog_hdr_t));
158
159 if (!ndo->ndo_suppress_default_print)
160 ND_DEFAULTPRINT(p, caplen);
161 break;
162 }
163
164 return h_size;
165 }
166
167 #endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */
168