/*	$eterna: make-promisc.c,v 1.2 2016/12/29 23:32:13 mrg Exp $	*/

/*
 * make-promisc.c.  set an interface to promisc and sleep forever.
 * helps netbsd cnmac(4) which drops packets for about 9 seconds
 * every time it goes in or out of promisc.
 */

#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>

#include <net/bpf.h>
#include <net/if.h>

#include <stdio.h>
#include <err.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>

int
main(int argc, char *argv[])
{
	struct ifreq ifr;
	const char *interface = "cnmac0";
	int fd;

	if (argc >= 2)
		interface = *(++argv);

	while (interface) {
		fd = open("/dev/bpf", O_RDWR);
		if (fd == -1)
			err(1, "open /dev/bpf");

		memset(&ifr, 0, sizeof(ifr));
		strlcpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
		if (ioctl(fd, BIOCSETIF, &ifr) == -1)
			err(1, "BIOCSETIF");

		if (ioctl(fd, BIOCPROMISC, &ifr) == -1)
			err(1, "BIOCPROMISC");
		//printf("checking intf %s\n", interface);

		if (argc < 2)
			break;
		interface = *(++argv);
	}

	// try to ignore reboot time failure.
	signal(SIGTERM, SIG_IGN);

	pause();
}