/*      $OpenBSD: kqueue-signal.c,v 1.3 2016/09/20 23:05:27 bluhm Exp $ */
/*
 *      Written by Philip Guenther <guenther@openbsd.org> 2011 Public Domain
 */

#include <sys/types.h>
#include <sys/event.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>

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

#include "main.h"

volatile sig_atomic_t saw_usr1 = 0;
volatile sig_atomic_t result = 0;
int kq;

int
sigtest(int signum, int catch)
{
        struct kevent ke;
        struct timespec ts;

        ts.tv_sec = 10;
        ts.tv_nsec = 0;

        ASS(kevent(kq, NULL, 0, &ke, 1, &ts) == 1,
            warn("can't fetch event on kqueue"));
        ASSX(ke.filter == EVFILT_SIGNAL);
        ASSX(ke.ident == signum);
        ASSX(ke.data == catch);
        return (0);
}

void
usr1handler(int signum)
{
        saw_usr1 = 1;
        result = sigtest(SIGUSR1, 1);
}

int
do_signal(void)
{
        struct kevent ke;
        pid_t pid = getpid();
        sigset_t mask;

        ASS((kq = kqueue()) >= 0, warn("kqueue"));

        signal(SIGUSR1, usr1handler);
        signal(SIGUSR2, SIG_IGN);

        EV_SET(&ke, SIGUSR1, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, NULL);
        ASS(kevent(kq, &ke, 1, NULL, 0, NULL) == 0,
            warn("can't register events on kqueue"));
        EV_SET(&ke, SIGUSR2, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, NULL);
        ASS(kevent(kq, &ke, 1, NULL, 0, NULL) == 0,
            warn("can't register events on kqueue"));

        EV_SET(&ke, 10000, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, NULL);
        ASS(kevent(kq, &ke, 1, NULL, 0, NULL) != 0,
            warnx("registered bogus signal on kqueue"));
        ASS(errno == EINVAL,
            warn("registering bogus signal on kqueue returned wrong error"));

        ASSX(saw_usr1 == 0);
        kill(pid, SIGUSR1);
        ASSX(saw_usr1 == 1);

        kill(pid, SIGUSR2);
        ASSX(sigtest(SIGUSR2, 1) == 0);
        kill(pid, SIGUSR2);
        kill(pid, SIGUSR2);
        ASSX(sigtest(SIGUSR2, 2) == 0);

        sigemptyset(&mask);
        sigaddset(&mask, SIGUSR1);
        sigaddset(&mask, SIGUSR2);
        sigprocmask(SIG_BLOCK, &mask, NULL);

        signal(SIGUSR1, SIG_DFL);
        kill(pid, SIGUSR1);
        kill(pid, SIGUSR2);

        close(kq);

        return (0);
}