int mnlg_socket_recv_run(struct mnlg_socket *nlg, mnl_cb_t data_cb, void *data)
{
int err;
do {
err = mnl_socket_recvfrom(nlg->nl, nlg->buf,
MNL_SOCKET_BUFFER_SIZE);
if (err <= 0)
break;
err = mnl_cb_run2(nlg->buf, err, nlg->seq, nlg->portid,
data_cb, data, mnlg_cb_array,
ARRAY_SIZE(mnlg_cb_array));
} while (err > 0);
return err;
}
static void
send_batch(struct mnl_socket *nl, struct mnl_nlmsg_batch *b, int portid)
{
int ret, fd = mnl_socket_get_fd(nl);
size_t len = mnl_nlmsg_batch_size(b);
char rcv_buf[MNL_SOCKET_BUFFER_SIZE];
ret = mnl_socket_sendto(nl, mnl_nlmsg_batch_head(b), len);
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
/* receive and digest all the acknowledgments from the kernel. */
struct timeval tv = {
.tv_sec = 0,
.tv_usec = 0
};
fd_set readfds;
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
ret = select(fd+1, &readfds, NULL, NULL, &tv);
if (ret == -1) {
perror("select");
exit(EXIT_FAILURE);
}
while (ret > 0 && FD_ISSET(fd, &readfds)) {
ret = mnl_socket_recvfrom(nl, rcv_buf, sizeof(rcv_buf));
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
ret = mnl_cb_run2(rcv_buf, ret, 0, portid,
NULL, NULL, cb_ctl_array,
MNL_ARRAY_SIZE(cb_ctl_array));
if (ret == -1) {
perror("mnl_cb_run");
exit(EXIT_FAILURE);
}
ret = select(fd+1, &readfds, NULL, NULL, &tv);
if (ret == -1) {
perror("select");
exit(EXIT_FAILURE);
}
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
}
}
int main(void)
{
struct mnl_socket *nl;
char snd_buf[MNL_SOCKET_BUFFER_SIZE*2];
struct mnl_nlmsg_batch *b;
int j;
unsigned int seq, portid;
uint16_t i;
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);
/* The buffer that we use to batch messages is MNL_SOCKET_BUFFER_SIZE
* multiplied by 2 bytes long, but we limit the batch to half of it
* since the last message that does not fit the batch goes over the
* upper boundary, if you break this rule, expect memory corruptions. */
b = mnl_nlmsg_batch_start(snd_buf, MNL_SOCKET_BUFFER_SIZE);
if (b == NULL) {
perror("mnl_nlmsg_batch_start");
exit(EXIT_FAILURE);
}
seq = time(NULL);
for (i=1024, j=0; i<65535; i++, j++) {
put_msg(mnl_nlmsg_batch_current(b), i, seq+j);
/* is there room for more messages in this batch?
* if so, continue. */
if (mnl_nlmsg_batch_next(b))
continue;
send_batch(nl, b, portid);
/* this moves the last message that did not fit into the
* batch to the head of it. */
mnl_nlmsg_batch_reset(b);
}
/* check if there is any message in the batch not sent yet. */
if (!mnl_nlmsg_batch_is_empty(b))
send_batch(nl, b, portid);
mnl_nlmsg_batch_stop(b);
mnl_socket_close(nl);
return 0;
}
