sys/kern/unix_passfd_test.c

/*-
 * Copyright (c) 2005 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.
 *
 * $FreeBSD: head/tools/regression/sockets/unix_passfd/unix_passfd.c 152251 2005-11-09 21:41:20Z rwatson $
 */

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

#include <err.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

/*
 * UNIX domain sockets allow file descriptors to be passed via "ancillary
 * data", or control messages.  This regression test is intended to exercise
 * this facility, both performing some basic tests that it operates, and also
 * causing some kernel edge cases to execute, such as garbage collection when
 * there are cyclic file descriptor references.  Right now we test only with
 * stream sockets, but ideally we'd also test with datagram sockets.
 */

static void
domainsocketpair(const char *test, int *fdp)
{

	if (socketpair(PF_UNIX, SOCK_STREAM, 0, fdp) < 0)
		err(-1, "%s: socketpair(PF_UNIX, SOCK_STREAM)", test);
}

static void
closesocketpair(int *fdp)
{

	close(fdp[0]);
	close(fdp[1]);
}

static void
tempfile(const char *test, int *fdp)
{
	char path[PATH_MAX];
	int fd;

	snprintf(path, PATH_MAX, "/tmp/unix_passfd.XXXXXXXXXXXXXXX");
	fd = mkstemp(path);
	if (fd < 0)
		err(-1, "%s: mkstemp(%s)", test, path);
	(void)unlink(path);
	*fdp = fd;
}

static void
dofstat(const char *test, int fd, struct stat *sb)
{

	if (fstat(fd, sb) < 0)
		err(-1, "%s: fstat", test);
}

static void
samefile(const char *test, struct stat *sb1, struct stat *sb2)
{

	if (sb1->st_dev != sb2->st_dev)
		err(-1, "%s: samefile: different device", test);
	if (sb1->st_ino != sb2->st_ino)
		err(-1, "%s: samefile: different inode", test);
}

static void
sendfd(const char *test, int sockfd, int sendfd)
{
	struct iovec iovec;
	char ch;

	struct {
		struct cmsghdr cmsghdr;
		int fd;
	} message;
	struct msghdr msghdr;
	ssize_t len;

	bzero(&msghdr, sizeof(msghdr));
	bzero(&message, sizeof(message));
	ch = 0;

	msghdr.msg_control = &message;
	msghdr.msg_controllen = sizeof(message);

	iovec.iov_base = &ch;
	iovec.iov_len = sizeof(ch);

	msghdr.msg_iov = &iovec;
	msghdr.msg_iovlen = 1;

	message.cmsghdr.cmsg_len = sizeof(message);
	message.cmsghdr.cmsg_level = SOL_SOCKET;
	message.cmsghdr.cmsg_type = SCM_RIGHTS;
	message.fd = sendfd;

	len = sendmsg(sockfd, &msghdr, 0);
	if (len < 0)
		err(-1, "%s: sendmsg", test);
	if (len != sizeof(ch))
		errx(-1, "%s: sendmsg: %d bytes sent", test, len);
}

static void
recvfd(const char *test, int sockfd, int *recvfd)
{
	struct {
		struct cmsghdr cmsghdr;
		int fd;
	} message;
	struct msghdr msghdr;
	struct iovec iovec;
	ssize_t len;
	char ch;

	bzero(&msghdr, sizeof(msghdr));
	bzero(&message, sizeof(message));
	ch = 0;

	msghdr.msg_control = &message;
	msghdr.msg_controllen = sizeof(message);

	iovec.iov_base = &ch;
	iovec.iov_len = sizeof(ch);

	msghdr.msg_iov = &iovec;
	msghdr.msg_iovlen = 1;

	iovec.iov_len = sizeof(ch);

	msghdr.msg_iov = &iovec;
	msghdr.msg_iovlen = 1;

	message.cmsghdr.cmsg_len = sizeof(message);
	message.cmsghdr.cmsg_level = SOL_SOCKET;
	message.cmsghdr.cmsg_type = SCM_RIGHTS;
	message.fd = -1;

	len = recvmsg(sockfd, &msghdr, 0);
	if (len < 0)
		err(-1, "%s: recvmsg", test);
	if (len != sizeof(ch))
		errx(-1, "%s: recvmsg: %d bytes received", test, len);
	if (message.fd == -1)
		errx(-1, "%s: recvmsg: received fd -1", test);
	*recvfd = message.fd;
}

int
main(int argc, char *argv[])
{
	struct stat putfd_1_stat, putfd_2_stat, getfd_1_stat, getfd_2_stat;
	int fd[2], putfd_1, putfd_2, getfd_1, getfd_2;
	const char *test;

	/*
	 * First test: put a temporary file into a UNIX domain socket, then
	 * take it out and make sure it's the same file.  First time around,
	 * don't close the reference after sending.
	 */
	test = "test1-simplesendfd";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);
	tempfile(test, &putfd_1);
	dofstat(test, putfd_1, &putfd_1_stat);
	sendfd(test, fd[0], putfd_1);
	recvfd(test, fd[1], &getfd_1);
	dofstat(test, getfd_1, &getfd_1_stat);
	samefile(test, &putfd_1_stat, &getfd_1_stat);
	close(putfd_1);
	close(getfd_1);
	closesocketpair(fd);

	printf("%s passed\n", test);

	/*
	 * Second test: same as first, only close the file reference after
	 * sending, so that the only reference is the descriptor in the UNIX
	 * domain socket buffer.
	 */
	test = "test2-sendandclose";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);
	tempfile(test, &putfd_1);
	dofstat(test, putfd_1, &putfd_1_stat);
	sendfd(test, fd[0], putfd_1);
	close(putfd_1);
	recvfd(test, fd[1], &getfd_1);
	dofstat(test, getfd_1, &getfd_1_stat);
	samefile(test, &putfd_1_stat, &getfd_1_stat);
	close(getfd_1);
	closesocketpair(fd);

	printf("%s passed\n", test);

	/*
	 * Third test: put a temporary file into a UNIX domain socket, then
	 * close both endpoints causing garbage collection to kick off.
	 */
	test = "test3-sendandcancel";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);
	tempfile(test, &putfd_1);
	sendfd(test, fd[0], putfd_1);
	close(putfd_1);
	closesocketpair(fd);

	printf("%s passed\n", test);

	/*
	 * Send two files.  Then receive them.  Make sure they are returned
	 * in the right order, and both get there.
	 */

	test = "test4-twofile";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);
	tempfile(test, &putfd_1);
	tempfile(test, &putfd_2);
	dofstat(test, putfd_1, &putfd_1_stat);
	dofstat(test, putfd_2, &putfd_2_stat);
	sendfd(test, fd[0], putfd_1);
	sendfd(test, fd[0], putfd_2);
	close(putfd_1);
	close(putfd_2);
	recvfd(test, fd[1], &getfd_1);
	recvfd(test, fd[1], &getfd_2);
	dofstat(test, getfd_1, &getfd_1_stat);
	dofstat(test, getfd_2, &getfd_2_stat);
	samefile(test, &putfd_1_stat, &getfd_1_stat);
	samefile(test, &putfd_2_stat, &getfd_2_stat);
	close(getfd_1);
	close(getfd_2);
	closesocketpair(fd);

	printf("%s passed\n", test);

	/*
	 * Big bundling test.  Send an endpoint of the UNIX domain socket
	 * over itself, closing the door behind it.
	 */

	test = "test5-bundle";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);

	sendfd(test, fd[0], fd[0]);
	close(fd[0]);
	recvfd(test, fd[1], &getfd_1);
	close(getfd_1);
	close(fd[1]);

	printf("%s passed\n", test);

	/*
	 * Big bundling test part two: Send an endpoint of the UNIX domain
	 * socket over itself, close the door behind it, and never remove it
	 * from the other end.
	 */

	test = "test6-bundlecancel";
	printf("beginning %s\n", test);

	domainsocketpair(test, fd);
	sendfd(test, fd[0], fd[0]);
	sendfd(test, fd[1], fd[0]);
	closesocketpair(fd);

	printf("%s passed\n", test);

	return (0);
}