unix_sendtorace.c

/*-
 * Copyright (c) 2006 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Attempts to exercise UNIX domain socket races relating to the non-atomic
 * connect-and-send properties of sendto().  As the result of such a race is
 * a kernel panic, this test simply completes or doesn't.
 *
 * XXX: Despite implementing support for sendto() on stream sockets with
 * implied connect, the appropriate flag isn't set in the FreeBSD kernel so
 * it does not work.  For now, don't call the stream test.
 */

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

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

#define	ITERATIONS	1000000

static char socket_path[] = "tmp.XXXXXX";

static void
stream_server(int listenfd)
{
	int acceptfd;

	while (1) {
		acceptfd = accept(listenfd, NULL, NULL);
		if (acceptfd < 0) {
			warn("stream_server: accept");
			continue;
		}
		sleep(1);
		close(acceptfd);
	}
}

static void
stream_client(void)
{
	struct sockaddr_un sun;
	ssize_t len;
	char c = 0;
	int fd, i;

	bzero(&sun, sizeof(sun));
	sun.sun_len = sizeof(sun);
	sun.sun_family = AF_UNIX;
	strcpy(sun.sun_path, socket_path);
	for (i = 0; i < ITERATIONS; i++) {
		fd = socket(PF_UNIX, SOCK_STREAM, 0);
		if (fd < 0) {
			warn("stream_client: socket");
			return;
		}
		len = sendto(fd, &c, sizeof(c), 0, (struct sockaddr *)&sun,
		    sizeof(sun));
		if (len < 0)
			warn("stream_client: sendto");
		close(fd);
	}
}

static void
stream_test(void)
{
	struct sockaddr_un sun;
	pid_t childpid;
	int listenfd;

	listenfd = socket(PF_UNIX, SOCK_STREAM, 0);
	if (listenfd < 0)
		err(-1, "stream_test: socket");

	bzero(&sun, sizeof(sun));
	sun.sun_len = sizeof(sun);
	sun.sun_family = AF_UNIX;
	strcpy(sun.sun_path, socket_path);

	if (bind(listenfd, (struct sockaddr *)&sun, sizeof(sun)) < 0)
		err(-1, "stream_test: bind");

	if (listen(listenfd, -1) < 0)
		err(-1, "stream_test: listen");

	childpid = fork();
	if (childpid < 0)
		err(-1, "stream_test: fork");

	if (childpid != 0) {
		sleep(1);
		stream_client();
		kill(childpid, SIGTERM);
		sleep(1);
	} else
		stream_server(listenfd);

	(void)unlink(socket_path);
}

static void
datagram_server(int serverfd)
{
	ssize_t len;
	char c;

	while (1) {
		len = recv(serverfd, &c, sizeof(c), 0);
		if (len < 0)
			warn("datagram_server: recv");
	}
}

static void
datagram_client(void)
{
	struct sockaddr_un sun;
	ssize_t len;
	char c = 0;
	int fd, i;

	bzero(&sun, sizeof(sun));
	sun.sun_len = sizeof(sun);
	sun.sun_family = AF_UNIX;
	strcpy(sun.sun_path, socket_path);
	for (i = 0; i < ITERATIONS; i++) {
		fd = socket(PF_UNIX, SOCK_DGRAM, 0);
		if (fd < 0) {
			warn("datagram_client: socket");
			return;
		}
		len = sendto(fd, &c, sizeof(c), 0, (struct sockaddr *)&sun,
		    sizeof(sun));
		if (len < 0)
			warn("datagram_client: sendto");
		close(fd);
	}
}

static void
datagram_test(void)
{
	struct sockaddr_un sun;
	pid_t childpid;
	int serverfd;

	serverfd = socket(PF_UNIX, SOCK_DGRAM, 0);
	if (serverfd < 0)
		err(-1, "datagram_test: socket");

	bzero(&sun, sizeof(sun));
	sun.sun_len = sizeof(sun);
	sun.sun_family = AF_UNIX;
	strcpy(sun.sun_path, socket_path);

	if (bind(serverfd, (struct sockaddr *)&sun, sizeof(sun)) < 0)
		err(-1, "datagram_test: bind");

	childpid = fork();
	if (childpid < 0)
		err(-1, "datagram_test: fork");

	if (childpid != 0) {
		sleep(1);
		datagram_client();
		kill(childpid, SIGTERM);
		sleep(1);
	} else
		datagram_server(serverfd);

	(void)unlink(socket_path);
}

int
main(void)
{
	
	if (mkstemp(socket_path) == -1)
		err(1, "mkstemp failed");
	(void)unlink(socket_path);
	datagram_test();
	if (0)
		stream_test();
	return (0);
}