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/* This example is in the public domain. */
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <libmnl/libmnl.h>
#include <libnetfilter_cthelper/libnetfilter_cthelper.h>
static int nfct_helper_cb(const struct nlmsghdr *nlh, void *data)
{
struct nfct_helper *nfct_helper;
char buf[4096];
nfct_helper = nfct_helper_alloc();
if (nfct_helper == NULL) {
perror("OOM");
goto err;
}
if (nfct_helper_nlmsg_parse_payload(nlh, nfct_helper) < 0) {
perror("nfct_helper_parse_nl_msg");
goto err_free;
}
nfct_helper_snprintf(buf, sizeof(buf), nfct_helper, 0);
printf("%s\n", buf);
err_free:
nfct_helper_free(nfct_helper);
err:
return MNL_CB_OK;
}
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
uint32_t portid, seq;
int ret, full = 1;
if (argc != 1) {
fprintf(stderr, "Usage: %s\n", argv[0]);
exit(EXIT_FAILURE);
}
seq = time(NULL);
nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_GET,
NLM_F_DUMP, seq);
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);
}
portid = mnl_socket_get_portid(nl);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_send");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, nfct_helper_cb, &full);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (ret == -1) {
perror("error");
exit(EXIT_FAILURE);
}
mnl_socket_close(nl);
return EXIT_SUCCESS;
}
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