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 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <tcpdump-stdinc.h>
33
34 #include <stdio.h>
35 #include <pcap.h>
36
37 #include "netdissect.h"
38 #include "interface.h"
39
40 #if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
41 #include <pcap/nflog.h>
42
43 static const struct tok nflog_values[] = {
44 { AF_INET, "IPv4" },
45 { AF_INET6, "IPv6" },
46 { 0, NULL }
47 };
48
49 static inline void
nflog_hdr_print(struct netdissect_options * ndo,const nflog_hdr_t * hdr,u_int length)50 nflog_hdr_print(struct netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
51 {
52 ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
53
54 if (!ndo->ndo_qflag) {
55 ND_PRINT((ndo,", family %s (%d)",
56 tok2str(nflog_values, "Unknown",
57 hdr->nflog_family),
58 hdr->nflog_family));
59 } else {
60 ND_PRINT((ndo,", %s",
61 tok2str(nflog_values,
62 "Unknown NFLOG (0x%02x)",
63 hdr->nflog_family)));
64 }
65
66 ND_PRINT((ndo, ", length %u: ", length));
67 }
68
69 u_int
nflog_if_print(struct netdissect_options * ndo,const struct pcap_pkthdr * h,const u_char * p)70 nflog_if_print(struct netdissect_options *ndo,
71 const struct pcap_pkthdr *h, const u_char *p)
72 {
73 const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
74 const nflog_tlv_t *tlv;
75 u_int16_t size;
76 u_int16_t h_size = sizeof(nflog_hdr_t);
77 u_int caplen = h->caplen;
78 u_int length = h->len;
79
80 if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
81 ND_PRINT((ndo, "[|nflog]"));
82 return h_size;
83 }
84
85 if (!(hdr->nflog_version) == 0) {
86 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
87 return h_size;
88 }
89
90 if (ndo->ndo_eflag)
91 nflog_hdr_print(ndo, hdr, length);
92
93 p += sizeof(nflog_hdr_t);
94 length -= sizeof(nflog_hdr_t);
95 caplen -= sizeof(nflog_hdr_t);
96
97 while (length > 0) {
98 /* We have some data. Do we have enough for the TLV header? */
99 if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
100 /* No. */
101 ND_PRINT((ndo, "[|nflog]"));
102 return h_size;
103 }
104
105 tlv = (const nflog_tlv_t *) p;
106 size = tlv->tlv_length;
107 if (size % 4 != 0)
108 size += 4 - size % 4;
109
110 /* Is the TLV's length less than the minimum? */
111 if (size < sizeof(nflog_tlv_t)) {
112 /* Yes. Give up now. */
113 ND_PRINT((ndo, "[|nflog]"));
114 return h_size;
115 }
116
117 /* Do we have enough data for the full TLV? */
118 if (caplen < size || length < size) {
119 /* No. */
120 ND_PRINT((ndo, "[|nflog]"));
121 return h_size;
122 }
123
124 if (tlv->tlv_type == NFULA_PAYLOAD) {
125 /*
126 * This TLV's data is the packet payload.
127 * Skip past the TLV header, and break out
128 * of the loop so we print the packet data.
129 */
130 p += sizeof(nflog_tlv_t);
131 h_size += sizeof(nflog_tlv_t);
132 length -= sizeof(nflog_tlv_t);
133 caplen -= sizeof(nflog_tlv_t);
134 break;
135 }
136
137 p += size;
138 h_size += size;
139 length -= size;
140 caplen -= size;
141 }
142
143 switch (hdr->nflog_family) {
144
145 case AF_INET:
146 ip_print(ndo, p, length);
147 break;
148
149 #ifdef INET6
150 case AF_INET6:
151 ip6_print(ndo, p, length);
152 break;
153 #endif /*INET6*/
154
155 default:
156 if (!ndo->ndo_eflag)
157 nflog_hdr_print(ndo, hdr,
158 length + sizeof(nflog_hdr_t));
159
160 if (!ndo->ndo_suppress_default_print)
161 ndo->ndo_default_print(ndo, p, caplen);
162 break;
163 }
164
165 return h_size;
166 }
167
168 #endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */
169