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/*
 * Copyright (c) 2013, Petar Alilovic,
 * Faculty of Electrical Engineering and Computing, University of Zagreb
 * All rights reserved
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include "interface.h"

#if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
#include <pcap/nflog.h>

static const struct tok nflog_values[] = {
        { AF_INET,              "IPv4" },
#ifdef INET6
        { AF_INET6,             "IPv6" },
#endif /*INET6*/
        { 0,                    NULL }
};

static inline void
nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
{
        ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));

        if (!ndo->ndo_qflag) {
                ND_PRINT((ndo,", family %s (%d)",
                                                  tok2str(nflog_values, "Unknown",
                                                                  hdr->nflog_family),
                                                  hdr->nflog_family));
                } else {
                ND_PRINT((ndo,", %s",
                                                  tok2str(nflog_values,
                                                                  "Unknown NFLOG (0x%02x)",
                                                                  hdr->nflog_family)));
                }

        ND_PRINT((ndo, ", length %u: ", length));
}

u_int
nflog_if_print(netdissect_options *ndo,
                           const struct pcap_pkthdr *h, const u_char *p)
{
        const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
        const nflog_tlv_t *tlv;
        uint16_t size;
        uint16_t h_size = sizeof(nflog_hdr_t);
        u_int caplen = h->caplen;
        u_int length = h->len;

        if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
                ND_PRINT((ndo, "[|nflog]"));
                return h_size;
        }

        if (hdr->nflog_version != 0) {
                ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
                return h_size;
        }

        if (ndo->ndo_eflag)
                nflog_hdr_print(ndo, hdr, length);

        p += sizeof(nflog_hdr_t);
        length -= sizeof(nflog_hdr_t);
        caplen -= sizeof(nflog_hdr_t);

        while (length > 0) {
                /* We have some data.  Do we have enough for the TLV header? */
                if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
                        /* No. */
                        ND_PRINT((ndo, "[|nflog]"));
                        return h_size;
                }

                tlv = (const nflog_tlv_t *) p;
                size = tlv->tlv_length;
                if (size % 4 != 0)
                        size += 4 - size % 4;

                /* Is the TLV's length less than the minimum? */
                if (size < sizeof(nflog_tlv_t)) {
                        /* Yes. Give up now. */
                        ND_PRINT((ndo, "[|nflog]"));
                        return h_size;
                }

                /* Do we have enough data for the full TLV? */
                if (caplen < size || length < size) {
                        /* No. */
                        ND_PRINT((ndo, "[|nflog]"));
                        return h_size;
                }

                if (tlv->tlv_type == NFULA_PAYLOAD) {
                        /*
                         * This TLV's data is the packet payload.
                         * Skip past the TLV header, and break out
                         * of the loop so we print the packet data.
                         */
                        p += sizeof(nflog_tlv_t);
                        h_size += sizeof(nflog_tlv_t);
                        length -= sizeof(nflog_tlv_t);
                        caplen -= sizeof(nflog_tlv_t);
                        break;
                }

                p += size;
                h_size += size;
                length -= size;
                caplen -= size;
        }

        switch (hdr->nflog_family) {

        case AF_INET:
                ip_print(ndo, p, length);
                break;

#ifdef AF_INET6
        case AF_INET6:
                ip6_print(ndo, p, length);
                break;
#endif /* AF_INET6 */

        default:
                if (!ndo->ndo_eflag)
                        nflog_hdr_print(ndo, hdr,
                                length + sizeof(nflog_hdr_t));

                if (!ndo->ndo_suppress_default_print)
                        ND_DEFAULTPRINT(p, caplen);
                break;
        }

        return h_size;
}

#endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */