sender.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <arpa/inet.h>

#include <libmnl/libmnl.h>

int main(int argc, char *argv[])
{
        struct mnl_socket *nl;
        char *buf;
        struct nlmsghdr *nlh;
        struct nfgenmsg *nfh;
        uint32_t portid;
        int ret;

        buf = malloc(1 << 30);

        if (argc != 2) {
                fprintf(stderr, "Usage: %s <portid>\n", argv[0]);
                exit(EXIT_FAILURE);
        }

        nl = mnl_socket_open(NETLINK_USERSOCK);
        if (nl == NULL) {
                perror("mnl_socket_open");
                exit(EXIT_FAILURE);
        }

        printf("connecting to port ID %d\n", atoi(argv[1]));
/*      if (mnl_socket_connect(nl, 0, atoi(argv[1])) < 0) {
                perror("mnl_socket_connect");
                exit(EXIT_FAILURE);
        }*/

        nlh = mnl_nlmsg_put_header(buf);
        nlh->nlmsg_type = 0;
        nlh->nlmsg_flags = 0;

        struct sockaddr_nl addr = {
                .nl_family = AF_NETLINK,
                .nl_pid = atoi(argv[1]),
        };

        ret = mnl_socket_send_addr(nl, buf, 1 << 30, &addr);
        if (ret == -1) {
                perror("mnl_socket_sendto");
                exit(EXIT_FAILURE);
        }
/*
        portid = mnl_socket_get_portid(nl);

        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;
}