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/* This example is placed in the public domain. */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <arpa/inet.h>
#include <inttypes.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
static int parse_counters_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, CTA_COUNTERS_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case CTA_COUNTERS_PACKETS:
case CTA_COUNTERS_BYTES:
if (mnl_attr_validate(attr, MNL_TYPE_U64) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void print_counters(const struct nlattr *nest)
{
struct nlattr *tb[CTA_COUNTERS_MAX+1] = {};
mnl_attr_parse_nested(nest, parse_counters_cb, tb);
if (tb[CTA_COUNTERS_PACKETS]) {
printf("packets=%"PRIu64" ",
be64toh(mnl_attr_get_u64(tb[CTA_COUNTERS_PACKETS])));
}
if (tb[CTA_COUNTERS_BYTES]) {
printf("bytes=%"PRIu64" ",
be64toh(mnl_attr_get_u64(tb[CTA_COUNTERS_BYTES])));
}
}
static int parse_ip_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, CTA_IP_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case CTA_IP_V4_SRC:
case CTA_IP_V4_DST:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case CTA_IP_V6_SRC:
case CTA_IP_V6_DST:
if (mnl_attr_validate2(attr, MNL_TYPE_BINARY,
sizeof(struct in6_addr)) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void print_ip(const struct nlattr *nest)
{
struct nlattr *tb[CTA_IP_MAX+1] = {};
mnl_attr_parse_nested(nest, parse_ip_cb, tb);
if (tb[CTA_IP_V4_SRC]) {
struct in_addr *in = mnl_attr_get_payload(tb[CTA_IP_V4_SRC]);
printf("src=%s ", inet_ntoa(*in));
}
if (tb[CTA_IP_V4_DST]) {
struct in_addr *in = mnl_attr_get_payload(tb[CTA_IP_V4_DST]);
printf("dst=%s ", inet_ntoa(*in));
}
if (tb[CTA_IP_V6_SRC]) {
struct in6_addr *in = mnl_attr_get_payload(tb[CTA_IP_V6_SRC]);
char out[INET6_ADDRSTRLEN];
if (!inet_ntop(AF_INET6, in, out, sizeof(out)))
printf("src=%s ", out);
}
if (tb[CTA_IP_V6_DST]) {
struct in6_addr *in = mnl_attr_get_payload(tb[CTA_IP_V6_DST]);
char out[INET6_ADDRSTRLEN];
if (!inet_ntop(AF_INET6, in, out, sizeof(out)))
printf("dst=%s ", out);
}
}
static int parse_proto_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, CTA_PROTO_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case CTA_PROTO_NUM:
case CTA_PROTO_ICMP_TYPE:
case CTA_PROTO_ICMP_CODE:
if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case CTA_PROTO_SRC_PORT:
case CTA_PROTO_DST_PORT:
case CTA_PROTO_ICMP_ID:
if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void print_proto(const struct nlattr *nest)
{
struct nlattr *tb[CTA_PROTO_MAX+1] = {};
mnl_attr_parse_nested(nest, parse_proto_cb, tb);
if (tb[CTA_PROTO_NUM]) {
printf("proto=%u ", mnl_attr_get_u8(tb[CTA_PROTO_NUM]));
}
if (tb[CTA_PROTO_SRC_PORT]) {
printf("sport=%u ",
ntohs(mnl_attr_get_u16(tb[CTA_PROTO_SRC_PORT])));
}
if (tb[CTA_PROTO_DST_PORT]) {
printf("dport=%u ",
ntohs(mnl_attr_get_u16(tb[CTA_PROTO_DST_PORT])));
}
if (tb[CTA_PROTO_ICMP_ID]) {
printf("id=%u ",
ntohs(mnl_attr_get_u16(tb[CTA_PROTO_ICMP_ID])));
}
if (tb[CTA_PROTO_ICMP_TYPE]) {
printf("type=%u ", mnl_attr_get_u8(tb[CTA_PROTO_ICMP_TYPE]));
}
if (tb[CTA_PROTO_ICMP_CODE]) {
printf("code=%u ", mnl_attr_get_u8(tb[CTA_PROTO_ICMP_CODE]));
}
}
static int parse_tuple_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, CTA_TUPLE_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case CTA_TUPLE_IP:
if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case CTA_TUPLE_PROTO:
if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void print_tuple(const struct nlattr *nest)
{
struct nlattr *tb[CTA_TUPLE_MAX+1] = {};
mnl_attr_parse_nested(nest, parse_tuple_cb, tb);
if (tb[CTA_TUPLE_IP]) {
print_ip(tb[CTA_TUPLE_IP]);
}
if (tb[CTA_TUPLE_PROTO]) {
print_proto(tb[CTA_TUPLE_PROTO]);
}
}
static int data_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, CTA_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case CTA_TUPLE_ORIG:
case CTA_COUNTERS_ORIG:
case CTA_COUNTERS_REPLY:
if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case CTA_TIMEOUT:
case CTA_MARK:
case CTA_SECMARK:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int data_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[CTA_MAX+1] = {};
struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
mnl_attr_parse(nlh, sizeof(*nfg), data_attr_cb, tb);
if (tb[CTA_TUPLE_ORIG])
print_tuple(tb[CTA_TUPLE_ORIG]);
if (tb[CTA_MARK])
printf("mark=%u ", ntohl(mnl_attr_get_u32(tb[CTA_MARK])));
if (tb[CTA_SECMARK])
printf("secmark=%u ", ntohl(mnl_attr_get_u32(tb[CTA_SECMARK])));
if (tb[CTA_COUNTERS_ORIG]) {
printf("original ");
print_counters(tb[CTA_COUNTERS_ORIG]);
}
if (tb[CTA_COUNTERS_REPLY]) {
printf("reply ");
print_counters(tb[CTA_COUNTERS_REPLY]);
}
printf("\n");
return MNL_CB_OK;
}
int main(void)
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct nfgenmsg *nfh;
uint32_t seq, portid;
int ret;
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
perror("mnl_socket_open");
exit(EXIT_FAILURE);
}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
perror("mnl_socket_bind");
exit(EXIT_FAILURE);
}
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL);
nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfh->nfgen_family = AF_INET;
nfh->version = NFNETLINK_V0;
nfh->res_id = 0;
ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
portid = mnl_socket_get_portid(nl);
while (1) {
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
if (ret == -1) {
perror("mnl_cb_run");
exit(EXIT_FAILURE);
} else if (ret <= MNL_CB_STOP)
break;
}
mnl_socket_close(nl);
return 0;
}
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