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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.
*/
/* \summary: DLT_NFLOG printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include "netdissect.h"
#include "extract.h"
#ifdef DLT_NFLOG
/*
* Structure of an NFLOG header and TLV parts, as described at
* https://www.tcpdump.org/linktypes/LINKTYPE_NFLOG.html
*
* The NFLOG header is big-endian.
*
* The TLV length and type are in host byte order. The value is either
* big-endian or is an array of bytes in some externally-specified byte
* order (text string, link-layer address, link-layer header, packet
* data, etc.).
*/
typedef struct nflog_hdr {
nd_uint8_t nflog_family; /* address family */
nd_uint8_t nflog_version; /* version */
nd_uint16_t nflog_rid; /* resource ID */
} nflog_hdr_t;
#define NFLOG_HDR_LEN sizeof(nflog_hdr_t)
typedef struct nflog_tlv {
nd_uint16_t tlv_length; /* tlv length */
nd_uint16_t tlv_type; /* tlv type */
/* value follows this */
} nflog_tlv_t;
#define NFLOG_TLV_LEN sizeof(nflog_tlv_t)
typedef struct nflog_packet_hdr {
nd_uint16_t hw_protocol; /* hw protocol */
nd_uint8_t hook; /* netfilter hook */
nd_byte pad[1]; /* padding to 32 bits */
} nflog_packet_hdr_t;
typedef struct nflog_hwaddr {
nd_uint16_t hw_addrlen; /* address length */
nd_byte pad[2]; /* padding to 32-bit boundary */
nd_byte hw_addr[8]; /* address, up to 8 bytes */
} nflog_hwaddr_t;
typedef struct nflog_timestamp {
nd_uint64_t sec;
nd_uint64_t usec;
} nflog_timestamp_t;
/*
* TLV types.
*/
#define NFULA_PACKET_HDR 1 /* nflog_packet_hdr_t */
#define NFULA_MARK 2 /* packet mark from skbuff */
#define NFULA_TIMESTAMP 3 /* nflog_timestamp_t for skbuff's time stamp */
#define NFULA_IFINDEX_INDEV 4 /* ifindex of device on which packet received (possibly bridge group) */
#define NFULA_IFINDEX_OUTDEV 5 /* ifindex of device on which packet transmitted (possibly bridge group) */
#define NFULA_IFINDEX_PHYSINDEV 6 /* ifindex of physical device on which packet received (not bridge group) */
#define NFULA_IFINDEX_PHYSOUTDEV 7 /* ifindex of physical device on which packet transmitted (not bridge group) */
#define NFULA_HWADDR 8 /* nflog_hwaddr_t for hardware address */
#define NFULA_PAYLOAD 9 /* packet payload */
#define NFULA_PREFIX 10 /* text string - null-terminated, count includes NUL */
#define NFULA_UID 11 /* UID owning socket on which packet was sent/received */
#define NFULA_SEQ 12 /* sequence number of packets on this NFLOG socket */
#define NFULA_SEQ_GLOBAL 13 /* sequence number of pakets on all NFLOG sockets */
#define NFULA_GID 14 /* GID owning socket on which packet was sent/received */
#define NFULA_HWTYPE 15 /* ARPHRD_ type of skbuff's device */
#define NFULA_HWHEADER 16 /* skbuff's MAC-layer header */
#define NFULA_HWLEN 17 /* length of skbuff's MAC-layer header */
static const struct tok nflog_values[] = {
{ AF_INET, "IPv4" },
{ AF_INET6, "IPv6" },
{ 0, NULL }
};
static void
nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
{
ND_PRINT("version %u, resource ID %u",
GET_U_1(hdr->nflog_version), GET_BE_U_2(hdr->nflog_rid));
if (!ndo->ndo_qflag) {
ND_PRINT(", family %s (%u)",
tok2str(nflog_values, "Unknown",
GET_U_1(hdr->nflog_family)),
GET_U_1(hdr->nflog_family));
} else {
ND_PRINT(", %s",
tok2str(nflog_values,
"Unknown NFLOG (0x%02x)",
GET_U_1(hdr->nflog_family)));
}
ND_PRINT(", length %u: ", length);
}
void
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;
uint16_t size;
uint16_t h_size = NFLOG_HDR_LEN;
u_int caplen = h->caplen;
u_int length = h->len;
ndo->ndo_protocol = "nflog";
if (caplen < NFLOG_HDR_LEN) {
nd_print_trunc(ndo);
ndo->ndo_ll_hdr_len += caplen;
return;
}
ndo->ndo_ll_hdr_len += NFLOG_HDR_LEN;
ND_TCHECK_SIZE(hdr);
if (GET_U_1(hdr->nflog_version) != 0) {
ND_PRINT("version %u (unknown)", GET_U_1(hdr->nflog_version));
return;
}
if (ndo->ndo_eflag)
nflog_hdr_print(ndo, hdr, length);
p += NFLOG_HDR_LEN;
length -= NFLOG_HDR_LEN;
caplen -= NFLOG_HDR_LEN;
while (length > 0) {
const nflog_tlv_t *tlv;
/* We have some data. Do we have enough for the TLV header? */
if (caplen < NFLOG_TLV_LEN)
goto trunc; /* No. */
tlv = (const nflog_tlv_t *) p;
ND_TCHECK_SIZE(tlv);
size = GET_HE_U_2(tlv->tlv_length);
if (size % 4 != 0)
size += 4 - size % 4;
/* Is the TLV's length less than the minimum? */
if (size < NFLOG_TLV_LEN)
goto trunc; /* Yes. Give up now. */
/* Do we have enough data for the full TLV? */
if (caplen < size)
goto trunc; /* No. */
if (GET_HE_U_2(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 += NFLOG_TLV_LEN;
h_size += NFLOG_TLV_LEN;
length -= NFLOG_TLV_LEN;
caplen -= NFLOG_TLV_LEN;
break;
}
p += size;
h_size += size;
length -= size;
caplen -= size;
}
switch (GET_U_1(hdr->nflog_family)) {
case AF_INET:
ip_print(ndo, p, length);
break;
case AF_INET6:
ip6_print(ndo, p, length);
break;
default:
if (!ndo->ndo_eflag)
nflog_hdr_print(ndo, hdr,
length + NFLOG_HDR_LEN);
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
break;
}
ndo->ndo_ll_hdr_len += h_size - NFLOG_HDR_LEN;
return;
trunc:
nd_print_trunc(ndo);
ndo->ndo_ll_hdr_len += h_size - NFLOG_HDR_LEN;
}
#endif /* DLT_NFLOG */
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