nfct-mnl-event.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
static int data_cb(const struct nlmsghdr *nlh, void *data)
{
struct nf_conntrack *ct;
uint32_t type = NFCT_T_UNKNOWN;
char buf[4096];
switch(nlh->nlmsg_type & 0xFF) {
case IPCTNL_MSG_CT_NEW:
if (nlh->nlmsg_flags & (NLM_F_CREATE|NLM_F_EXCL))
type = NFCT_T_NEW;
else
type = NFCT_T_UPDATE;
break;
case IPCTNL_MSG_CT_DELETE:
type = NFCT_T_DESTROY;
break;
}
ct = nfct_new();
if (ct == NULL)
return MNL_CB_OK;
nfct_nlmsg_parse(nlh, ct);
nfct_snprintf(buf, sizeof(buf), ct,
type, NFCT_O_DEFAULT, 0);
printf("%s\n", buf);
nfct_destroy(ct);
return MNL_CB_OK;
}
int main(void)
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
int ret;
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
perror("mnl_socket_open");
exit(EXIT_FAILURE);
}
if (mnl_socket_bind(nl, NF_NETLINK_CONNTRACK_NEW |
NF_NETLINK_CONNTRACK_UPDATE |
NF_NETLINK_CONNTRACK_DESTROY,
MNL_SOCKET_AUTOPID) < 0) {
perror("mnl_socket_bind");
exit(EXIT_FAILURE);
}
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, 0, 0, data_cb, NULL);
if (ret == -1) {
perror("mnl_cb_run");
exit(EXIT_FAILURE);
}
}
mnl_socket_close(nl);
return 0;
}
nfct_destroy
void nfct_destroy(struct nf_conntrack *ct)
Definition conntrack/api.c:93
nfct_snprintf
int nfct_snprintf(char *buf, unsigned int size, const struct nf_conntrack *ct, const unsigned int msg_type, const unsigned int out_type, const unsigned int out_flags)
Definition conntrack/api.c:1113
nfct_new
struct nf_conntrack * nfct_new(void)
Definition conntrack/api.c:76