src/tests/sys/kern/unix_stream.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018 Alan Somers
 *
 * 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 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 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.
 */

#include <sys/cdefs.h>
#include <sys/socket.h>
#include <sys/event.h>
#include <sys/sysctl.h>
#include <sys/un.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <poll.h>

#include <atf-c.h>

static void
do_socketpair(int *sv)
{
	int s;

	s = socketpair(PF_LOCAL, SOCK_STREAM, 0, sv);
	ATF_REQUIRE_EQ(0, s);
	ATF_REQUIRE(sv[0] >= 0);
	ATF_REQUIRE(sv[1] >= 0);
	ATF_REQUIRE(sv[0] != sv[1]);
}

static u_long
getsendspace(void)
{
	u_long sendspace;

	ATF_REQUIRE_MSG(sysctlbyname("net.local.stream.sendspace", &sendspace,
	    &(size_t){sizeof(u_long)}, NULL, 0) != -1,
	    "sysctl net.local.stream.sendspace failed: %s", strerror(errno));

	return (sendspace);
}

/* getpeereid(3) should work with stream sockets created via socketpair(2) */
ATF_TC_WITHOUT_HEAD(getpeereid);
ATF_TC_BODY(getpeereid, tc)
{
	int sv[2];
	uid_t real_euid, euid;
	gid_t real_egid, egid;

	real_euid = geteuid();
	real_egid = getegid();

	do_socketpair(sv);

	ATF_REQUIRE_EQ(0, getpeereid(sv[0], &euid, &egid));
	ATF_CHECK_EQ(real_euid, euid);
	ATF_CHECK_EQ(real_egid, egid);

	ATF_REQUIRE_EQ(0, getpeereid(sv[1], &euid, &egid));
	ATF_CHECK_EQ(real_euid, euid);
	ATF_CHECK_EQ(real_egid, egid);

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

/* Sending zero bytes should succeed (once regressed in aba79b0f4a3f). */
ATF_TC_WITHOUT_HEAD(send_0);
ATF_TC_BODY(send_0, tc)
{
	int sv[2];

	do_socketpair(sv);
	ATF_REQUIRE(send(sv[0], sv, 0, 0) == 0);
	close(sv[0]);
	close(sv[1]);
}

static void
check_writable(int fd, int expect)
{
	fd_set wrfds;
	struct pollfd pfd[1];
	struct kevent kev;
	int nfds, kq;

	FD_ZERO(&wrfds);
	FD_SET(fd, &wrfds);
	nfds = select(fd + 1, NULL, &wrfds, NULL,
	    &(struct timeval){.tv_usec = 1000});
	ATF_REQUIRE_MSG(nfds == expect,
	    "select() returns %d errno %d", nfds, errno);

	pfd[0] = (struct pollfd){
		.fd = fd,
		.events = POLLOUT | POLLWRNORM,
	};
	nfds = poll(pfd, 1, 1);
	ATF_REQUIRE_MSG(nfds == expect,
	    "poll() returns %d errno %d", nfds, errno);

	ATF_REQUIRE(kq = kqueue());
	EV_SET(&kev, fd, EVFILT_WRITE, EV_ADD, 0, 0, NULL);
	ATF_REQUIRE(kevent(kq, &kev, 1, NULL, 0, NULL) == 0);
	nfds = kevent(kq, NULL, 0, &kev, 1,
	    &(struct timespec){.tv_nsec = 1000000});
	ATF_REQUIRE_MSG(nfds == expect,
		"kevent() returns %d errno %d", nfds, errno);
	close(kq);
}

/*
 * Make sure that a full socket is not reported as writable by event APIs.
 */
ATF_TC_WITHOUT_HEAD(full_not_writable);
ATF_TC_BODY(full_not_writable, tc)
{
	void *buf;
	u_long sendspace;
	int sv[2];

	sendspace = getsendspace();
	ATF_REQUIRE((buf = malloc(sendspace)) != NULL);
	do_socketpair(sv);
	ATF_REQUIRE(fcntl(sv[0], F_SETFL, O_NONBLOCK) != -1);
	do {} while (send(sv[0], buf, sendspace, 0) == (ssize_t)sendspace);
	ATF_REQUIRE(errno == EAGAIN);
	ATF_REQUIRE(fcntl(sv[0], F_SETFL, 0) != -1);

	check_writable(sv[0], 0);

	/* Read some data and re-check. */
	ATF_REQUIRE(read(sv[1], buf, sendspace / 2) == sendspace / 2);

	check_writable(sv[0], 1);

	free(buf);
	close(sv[0]);
	close(sv[1]);
}

ATF_TP_ADD_TCS(tp)
{
	ATF_TP_ADD_TC(tp, getpeereid);
	ATF_TP_ADD_TC(tp, send_0);
	ATF_TP_ADD_TC(tp, full_not_writable);

	return atf_no_error();
}