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/* $OpenBSD: unp-write-closed.c,v 1.1 2024/06/28 21:07:27 bluhm Exp $ */
/*
* Copyright (c) 2024 Vitaliy Makkoveev <mvs@openbsd.org>
* Copyright (c) 2024 Alenander Bluhm <bluhm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
sig_atomic_t done = 0;
void
handler(int sigraised)
{
done = 1;
}
int
main(int argc, char *argv[])
{
int i, s[2], status;
pid_t pid;
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
err(1, "signal pipe");
if (signal(SIGALRM, handler) == SIG_ERR)
err(1, "signal alrm");
alarm(30);
while (!done) {
if (socketpair(AF_UNIX, SOCK_STREAM, 0, s) < 0)
err(1, "socketpair");
switch ((pid = fork())) {
case -1:
err(1, "fork");
case 0:
if (close(s[0]) < 0)
err(1, "child close 0");
if (close(s[1]) < 0)
err(1, "child close 1");
return 0;
default:
if (close(s[1]) < 0)
err(1, "parent close 1");
for (i = 1000000; i > 0; i--) {
if (write(s[0], "1", 1) < 0)
break;
}
if (i <= 0)
errx(1, "write did not fail");
if (errno != EPIPE)
err(1, "write");
if (close(s[0]) < 0)
err(1, "parent close 1");
if (waitpid(pid, &status, 0) < 0)
err(1, "waitpid");
if (status != 0)
errx(1, "child status %d", status);
break;
}
}
return 0;
}
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