/*-
 * 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.
 */

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

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

/*
 * Simple regression test to exercise some error cases relating to the use of
 * bind() and connect() on UNIX domain sockets.  In particular, make sure
 * that when two sockets rendezvous using the file system name space, they
 * get the expected success/failure cases.
 *
 * TODO:
 * - Check that the resulting file mode/owner are right.
 * - Do the same tests with UNIX domain sockets.
 * - Check the results of getsockaddr() and getpeeraddr().
 */

#define SOCK_NAME_ONE   "socket.1"
#define SOCK_NAME_TWO   "socket.2"

#define UNWIND_MAX      1024

static int unwind_len;
static struct unwind {
        char    u_path[PATH_MAX];
} unwind_list[UNWIND_MAX];

static void
push_path(const char *path)
{

        if (unwind_len >= UNWIND_MAX)
                err(-1, "push_path: one path too many (%s)", path);

        strlcpy(unwind_list[unwind_len].u_path, path, PATH_MAX);
        unwind_len++;
}

static void
unwind(void)
{
        int i;

        for (i = unwind_len - 1; i >= 0; i--) {
                unlink(unwind_list[i].u_path);
                rmdir(unwind_list[i].u_path);
        }
}

static int
bind_test(const char *directory_path)
{
        char socket_path[PATH_MAX];
        struct sockaddr_un sun;
        int sock1, sock2;

        sock1 = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock1 < 0) {
                warn("bind_test: socket(PF_UNIX, SOCK_STREAM, 0)");
                return (-1);
        }

        if (snprintf(socket_path, sizeof(socket_path), "%s/%s",
            directory_path, SOCK_NAME_ONE) >= PATH_MAX) {
                warn("bind_test: snprintf(socket_path)");
                close(sock1);
                return (-1);
        }

        bzero(&sun, sizeof(sun));
        sun.sun_len = sizeof(sun);
        sun.sun_family = AF_UNIX;
        if (snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", socket_path)
            >= (int)sizeof(sun.sun_path)) {
                warn("bind_test: snprintf(sun.sun_path)");
                close(sock1);
                return (-1);
        }

        if (bind(sock1, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
                warn("bind_test: bind(sun) #1");
                close(sock1);
                return (-1);
        }

        push_path(socket_path);

        /*
         * Once a STREAM UNIX domain socket has been bound, it can't be
         * rebound.  Expected error is EINVAL.
         */
        if (bind(sock1, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
                warnx("bind_test: bind(sun) #2 succeeded");
                close(sock1);
                return (-1);
        }
        if (errno != EINVAL) {
                warn("bind_test: bind(sun) #2");
                close(sock1);
                return (-1);
        }

        sock2 = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock2 < 0) {
                warn("bind_test: socket(PF_UNIX, SOCK_STREAM, 0)");
                close(sock1);
                return (-1);
        }

        /*
         * Since a socket is already bound to the pathname, it can't be bound
         * to a second socket.  Expected error is EADDRINUSE.
         */
        if (bind(sock2, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
                warnx("bind_test: bind(sun) #3 succeeded");
                close(sock1);
                close(sock2);
                return (-1);
        }
        if (errno != EADDRINUSE) {
                warn("bind_test: bind(sun) #2");
                close(sock1);
                close(sock2);
                return (-1);
        }

        close(sock1);

        /*
         * The socket bound to the pathname has been closed, but the pathname
         * can't be reused without first being unlinked.  Expected error is
         * EADDRINUSE.
         */
        if (bind(sock2, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
                warnx("bind_test: bind(sun) #4 succeeded");
                close(sock2);
                return (-1);
        }
        if (errno != EADDRINUSE) {
                warn("bind_test: bind(sun) #4");
                close(sock2);
                return (-1);
        }

        unlink(socket_path);

        /*
         * The pathname is now free, so the socket should be able to bind to
         * it.
         */
        if (bind(sock2, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
                warn("bind_test: bind(sun) #5");
                close(sock2);
                return (-1);
        }

        close(sock2);
        return (0);
}

static int
connect_test(const char *directory_path)
{
        char socket_path[PATH_MAX];
        struct sockaddr_un sun;
        int sock1, sock2;

        sock1 = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock1 < 0) {
                warn("connect_test: socket(PF_UNIX, SOCK_STREAM, 0)");
                return (-1);
        }

        if (snprintf(socket_path, sizeof(socket_path), "%s/%s",
            directory_path, SOCK_NAME_TWO) >= PATH_MAX) {
                warn("connect_test: snprintf(socket_path)");
                close(sock1);
                return (-1);
        }

        bzero(&sun, sizeof(sun));
        sun.sun_len = sizeof(sun);
        sun.sun_family = AF_UNIX;
        if (snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", socket_path)
            >= (int)sizeof(sun.sun_path)) {
                warn("connect_test: snprintf(sun.sun_path)");
                close(sock1);
                return (-1);
        }

        /*
         * Try connecting to a path that doesn't yet exist.  Should fail with
         * ENOENT.
         */
        if (connect(sock1, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
                warnx("connect_test: connect(sun) #1 succeeded");
                close(sock1);
                return (-1);
        }
        if (errno != ENOENT) {
                warn("connect_test: connect(sun) #1");
                close(sock1);
                return (-1);
        }

        if (bind(sock1, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
                warn("connect_test: bind(sun) #1");
                close(sock1);
                return (-1);
        }

        if (listen(sock1, 3) < 0) {
                warn("connect_test: listen(sock1)");
                close(sock1);
                return (-1);
        }

        push_path(socket_path);

        sock2 = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock2 < 0) {
                warn("socket(PF_UNIX, SOCK_STREAM, 0)");
                close(sock1);
                return (-1);
        }

        /*
         * Do a simple connect and make sure that works.
         */
        if (connect(sock2, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
                warn("connect(sun) #2");
                close(sock1);
                return (-1);
        }

        close(sock2);

        close(sock1);

        sock2 = socket(PF_UNIX, SOCK_STREAM, 0);
        if (sock2 < 0) {
                warn("socket(PF_UNIX, SOCK_STREAM, 0)");
                return (-1);
        }

        /*
         * Confirm that once the listen socket is closed, we get a
         * connection refused (ECONNREFUSED) when attempting to connect to
         * the pathname.
         */
        if (connect(sock2, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
                warnx("connect(sun) #3 succeeded");
                close(sock2);
                return (-1);
        }
        if (errno != ECONNREFUSED) {
                warn("connect(sun) #3");
                close(sock2);
                return (-1);
        }

        close(sock2);
        unlink(socket_path);
        return (0);
}
int
main(void)
{
        char directory_path[PATH_MAX];
        int error;

        strlcpy(directory_path, "/tmp/unix_bind.XXXXXXX", PATH_MAX);
        if (mkdtemp(directory_path) == NULL)
                err(-1, "mkdtemp");
        push_path(directory_path);

        error = bind_test(directory_path);

        if (error == 0)
                error = connect_test(directory_path);

        unwind();
        return (error);
}