/**
* gcc events.c -o events -Wall -W -Wextra -lc
*
* Access to kernel events through Unix socket.
**/


#include <stdio.h>
#include <stdlib.h> /* calloc (), malloc () */
#include <string.h> /* strlcpy () */
#include <unistd.h> /* close () */

#include <sys/types.h>
#include <sys/socket.h> /* socket (), connect () */
#include <sys/un.h> /* struct sockaddr_un */
#include <sys/event.h>


#define DEVD_FILE "/var/run/devd.pipe"


void
devd_init_monitor () {
		int fd, kq;
		struct sockaddr_un addr;
		struct kevent *chlist, evlist;

		chlist = malloc (sizeof (struct kevent));
		
		fd = socket (PF_LOCAL, SOCK_STREAM, 0);
		if (fd < 0)
				fprintf (stderr, "Can't create socket\n");
		
		addr.sun_family = AF_UNIX;
		strlcpy (addr.sun_path, DEVD_FILE, sizeof (addr.sun_path));

		if (connect (fd, (struct sockaddr *) &addr, sizeof (addr)) < 0) {
				close (fd);
				fprintf (stderr, "Can't connect to DEVD daemon\n");
		}

		if ((kq = kqueue ()) < 0) {
				close (fd);
				fprintf (stderr, "No kernel event queue\n");
		}

		/* Initialise kevent structure */
		EV_SET (chlist, fd, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, 0);

		/* Infinite loop */
		for (;;) {
				if (kevent (kq, chlist, 1, &evlist, 1, NULL) == 1) {
						char *buffer = calloc (evlist.data, sizeof (intptr_t));

						recv (fd, buffer, evlist.data, 0);
						fprintf (stdout, "%s", buffer);
						free (buffer);
				}
		}

		free (chlist);
}


int
main (int argc, char *argv[]) {
		devd_init_monitor ();
		
		return 0;
}