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/*
* (C) 2006-2007 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include "network.h"
static void addattr(struct netpld *pld, int attr, const void *data, int len)
{
struct netattr *nta;
int tlen = NTA_LENGTH(len);
nta = PLD_TAIL(pld);
nta->nta_attr = htons(attr);
nta->nta_len = htons(len);
memcpy(NTA_DATA(nta), data, len);
pld->len += NTA_ALIGN(tlen);
}
static void __build_u8(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint8_t data = nfct_get_attr_u8(ct, attr);
addattr(pld, attr, &data, sizeof(uint8_t));
}
static void __build_u16(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint16_t data = nfct_get_attr_u16(ct, attr);
data = htons(data);
addattr(pld, attr, &data, sizeof(uint16_t));
}
static void __build_u32(const struct nf_conntrack *ct,
struct netpld *pld,
int attr)
{
uint32_t data = nfct_get_attr_u32(ct, attr);
data = htonl(data);
addattr(pld, attr, &data, sizeof(uint32_t));
}
static void __nat_build_u32(uint32_t data, struct netpld *pld, int attr)
{
data = htonl(data);
addattr(pld, attr, &data, sizeof(uint32_t));
}
static void __nat_build_u16(uint16_t data, struct netpld *pld, int attr)
{
data = htons(data);
addattr(pld, attr, &data, sizeof(uint16_t));
}
/* XXX: IPv6 and ICMP not supported */
void build_netpld(struct nf_conntrack *ct, struct netpld *pld, int query)
{
if (nfct_attr_is_set(ct, ATTR_IPV4_SRC))
__build_u32(ct, pld, ATTR_IPV4_SRC);
if (nfct_attr_is_set(ct, ATTR_IPV4_DST))
__build_u32(ct, pld, ATTR_IPV4_DST);
if (nfct_attr_is_set(ct, ATTR_L3PROTO))
__build_u8(ct, pld, ATTR_L3PROTO);
if (nfct_attr_is_set(ct, ATTR_PORT_SRC))
__build_u16(ct, pld, ATTR_PORT_SRC);
if (nfct_attr_is_set(ct, ATTR_PORT_DST))
__build_u16(ct, pld, ATTR_PORT_DST);
if (nfct_attr_is_set(ct, ATTR_L4PROTO)) {
uint8_t proto;
__build_u8(ct, pld, ATTR_L4PROTO);
proto = nfct_get_attr_u8(ct, ATTR_L4PROTO);
if (proto == IPPROTO_TCP) {
if (nfct_attr_is_set(ct, ATTR_TCP_STATE))
__build_u8(ct, pld, ATTR_TCP_STATE);
}
}
if (nfct_attr_is_set(ct, ATTR_TIMEOUT))
__build_u32(ct, pld, ATTR_TIMEOUT);
if (nfct_attr_is_set(ct, ATTR_MARK))
__build_u32(ct, pld, ATTR_MARK);
if (nfct_attr_is_set(ct, ATTR_SECMARK))
__build_u32(ct, pld, ATTR_SECMARK);
if (nfct_attr_is_set(ct, ATTR_STATUS))
__build_u32(ct, pld, ATTR_STATUS);
/* setup the master conntrack */
if (nfct_attr_is_set(ct, ATTR_MASTER_IPV4_SRC))
__build_u32(ct, pld, ATTR_MASTER_IPV4_SRC);
if (nfct_attr_is_set(ct, ATTR_MASTER_IPV4_DST))
__build_u32(ct, pld, ATTR_MASTER_IPV4_DST);
if (nfct_attr_is_set(ct, ATTR_MASTER_L3PROTO))
__build_u8(ct, pld, ATTR_MASTER_L3PROTO);
if (nfct_attr_is_set(ct, ATTR_MASTER_PORT_SRC))
__build_u16(ct, pld, ATTR_MASTER_PORT_SRC);
if (nfct_attr_is_set(ct, ATTR_MASTER_PORT_DST))
__build_u16(ct, pld, ATTR_MASTER_PORT_DST);
if (nfct_attr_is_set(ct, ATTR_MASTER_L4PROTO))
__build_u8(ct, pld, ATTR_MASTER_L4PROTO);
/* NAT */
if (nfct_getobjopt(ct, NFCT_GOPT_IS_SNAT)) {
uint32_t data = nfct_get_attr_u32(ct, ATTR_REPL_IPV4_DST);
__nat_build_u32(data, pld, ATTR_SNAT_IPV4);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_DNAT)) {
uint32_t data = nfct_get_attr_u32(ct, ATTR_REPL_IPV4_SRC);
__nat_build_u32(data, pld, ATTR_DNAT_IPV4);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_SPAT)) {
uint16_t data = nfct_get_attr_u16(ct, ATTR_REPL_PORT_DST);
__nat_build_u16(data, pld, ATTR_SNAT_PORT);
}
if (nfct_getobjopt(ct, NFCT_GOPT_IS_DPAT)) {
uint16_t data = nfct_get_attr_u16(ct, ATTR_REPL_PORT_SRC);
__nat_build_u16(data, pld, ATTR_DNAT_PORT);
}
pld->query = query;
PLD_HOST2NETWORK(pld);
}
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