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/* $OpenBSD: kqueue-fdpass.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"
int
do_fdpass(void)
{
struct msghdr msg;
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(int))];
} cmsgbuf;
struct kevent ke;
struct cmsghdr *cmp;
pid_t pid;
int pfd[2], fd, status;
ASS(socketpair(PF_LOCAL, SOCK_STREAM, 0, pfd) == 0,
warn("socketpair"));
pid = fork();
if (pid == -1)
err(1, "fork");
if (pid == 0) {
close(pfd[0]);
/* a kqueue with event to pass */
fd = kqueue();
EV_SET(&ke, SIGHUP, EVFILT_SIGNAL, EV_ADD|EV_ENABLE,
0, 0, NULL);
if (kevent(fd, &ke, 1, NULL, 0, NULL) != 0)
err(1, "can't register events on kqueue");
memset(&cmsgbuf.buf, 0, sizeof cmsgbuf.buf);
memset(&msg, 0, sizeof msg);
msg.msg_control = &cmsgbuf.buf;
msg.msg_controllen = sizeof(cmsgbuf);
cmp = CMSG_FIRSTHDR(&msg);
cmp->cmsg_len = CMSG_LEN(sizeof(int));
cmp->cmsg_level = SOL_SOCKET;
cmp->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmp) = fd;
if (sendmsg(pfd[1], &msg, 0) == 0)
errx(1, "sendmsg succeeded when it shouldn't");
if (errno != EINVAL)
err(1, "child sendmsg");
printf("sendmsg failed with EINVAL as expected\n");
close(pfd[1]);
exit(0);
}
close(pfd[1]);
wait(&status);
close(pfd[0]);
return (0);
}
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