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#include <stdlib.h>
#include <netinet/ip.h>
#include <linux/if_ether.h>
#include "proto.h"
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#define PRINT_CMP(...)
static void
l3_ipv4_ct_build_tuple(const uint8_t *pkt, struct nf_conntrack *ct)
{
const struct iphdr *iph = (const struct iphdr *)pkt;
nfct_set_attr_u16(ct, ATTR_ORIG_L3PROTO, AF_INET);
nfct_set_attr_u16(ct, ATTR_REPL_L3PROTO, AF_INET);
nfct_set_attr_u32(ct, ATTR_ORIG_IPV4_SRC, iph->saddr);
nfct_set_attr_u32(ct, ATTR_ORIG_IPV4_DST, iph->daddr);
nfct_set_attr_u32(ct, ATTR_REPL_IPV4_SRC, iph->daddr);
nfct_set_attr_u32(ct, ATTR_REPL_IPV4_DST, iph->saddr);
}
static int
l3_ipv4_ct_cmp_tuple_orig(const uint8_t *pkt, struct nf_conntrack *ct)
{
const struct iphdr *iph = (const struct iphdr *)pkt;
PRINT_CMP("cmp_orig iph->saddr: %x == %x\n",
iph->saddr, nfct_get_attr_u32(ct, ATTR_ORIG_IPV4_SRC));
PRINT_CMP("cmp_orig iph->daddr: %x == %x\n",
iph->daddr, nfct_get_attr_u32(ct, ATTR_ORIG_IPV4_DST));
if (iph->saddr == nfct_get_attr_u32(ct, ATTR_ORIG_IPV4_SRC) &&
iph->daddr == nfct_get_attr_u32(ct, ATTR_ORIG_IPV4_DST))
return 1;
return 0;
}
static int
l3_ipv4_ct_cmp_tuple_repl(const uint8_t *pkt, struct nf_conntrack *ct)
{
const struct iphdr *iph = (const struct iphdr *)pkt;
PRINT_CMP("cmp_repl iph->saddr: %x == %x\n",
iph->saddr, nfct_get_attr_u32(ct, ATTR_REPL_IPV4_SRC));
PRINT_CMP("cmp_repl iph->daddr: %x == %x\n",
iph->daddr, nfct_get_attr_u32(ct, ATTR_REPL_IPV4_DST));
if (iph->saddr == nfct_get_attr_u32(ct, ATTR_REPL_IPV4_SRC) &&
iph->daddr == nfct_get_attr_u32(ct, ATTR_REPL_IPV4_DST))
return 1;
return 0;
}
static int l3_ipv4_pkt_l4proto_num(const uint8_t *pkt)
{
const struct iphdr *iph = (const struct iphdr *)pkt;
return iph->protocol;
}
static int l3_ipv4_pkt_l3hdr_len(const uint8_t *pkt)
{
const struct iphdr *iph = (const struct iphdr *)pkt;
return iph->ihl << 2;
}
static struct cthelper_proto_l2l3_helper ipv4 = {
.l2protonum = ETH_P_IP,
.l3protonum = AF_INET,
.l2hdr_len = ETH_HLEN,
.l3ct_build = l3_ipv4_ct_build_tuple,
.l3ct_cmp_orig = l3_ipv4_ct_cmp_tuple_orig,
.l3ct_cmp_repl = l3_ipv4_ct_cmp_tuple_repl,
.l3pkt_hdr_len = l3_ipv4_pkt_l3hdr_len,
.l4pkt_proto = l3_ipv4_pkt_l4proto_num,
};
void l2l3_ipv4_init(void)
{
cthelper_proto_l2l3_helper_register(&ipv4);
}
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