/*-
 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
 * Authors: Doug Rabson <dfr@rabson.org>
 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
 *
 * 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/param.h>
#include <sys/file.h>
#include <sys/time.h>
#ifdef __FreeBSD__
#include <sys/mount.h>
#endif
#include <sys/stat.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef __FreeBSD__
#if __FreeBSD_version >= 800028
#define HAVE_SYSID
#endif
#include <sys/cdefs.h>
#else
#ifndef nitems
#define nitems(x)       (sizeof((x)) / sizeof((x)[0]))
#endif

#ifndef __unused
#ifdef __GNUC__
#define __unused        __attribute__((__unused__))
#else
#define __unused
#endif
#endif
#endif

static int verbose = 0;

static int
make_file(const char *pathname, off_t sz)
{
        struct stat st;
        const char *template = "/flocktempXXXXXX";
        size_t len;
        char *filename;
        int fd;

        if (stat(pathname, &st) == 0) {
                if (S_ISREG(st.st_mode)) {
                        fd = open(pathname, O_RDWR);
                        if (fd < 0)
                                err(1, "open(%s)", pathname);
                        if (ftruncate(fd, sz) < 0)
                                err(1, "ftruncate");
                        return (fd);
                }
        }

        len = strlen(pathname) + strlen(template) + 1;
        filename = malloc(len);
        strcpy(filename, pathname);
        strcat(filename, template);
        fd = mkstemp(filename);
        if (fd < 0)
                err(1, "mkstemp");
        if (ftruncate(fd, sz) < 0)
                err(1, "ftruncate");
        if (unlink(filename) < 0)
                err(1, "unlink");
        free(filename);

        return (fd);
}

static void
ignore_alarm(int __unused sig)
{
}

static int
safe_waitpid(pid_t pid)
{
        int save_errno;
        int status;

        save_errno = errno;
        errno = 0;
        while (waitpid(pid, &status, 0) != pid) {
                if (errno == EINTR)
                        continue;
                err(1, "waitpid");
        }
        errno = save_errno;

        return (status);
}

#define FAIL(test)                                      \
        do {                                            \
                if (test) {                             \
                        printf("FAIL (%s)\n", #test);   \
                        return -1;                      \
                }                                       \
        } while (0)

#define SUCCEED \
        do { printf("SUCCEED\n"); return 0; } while (0)

/*
 * Test 1 - F_GETLK on unlocked region
 *
 * If no lock is found that would prevent this lock from being
 * created, the structure is left unchanged by this function call
 * except for the lock type which is set to F_UNLCK.
 */
static int
test1(int fd, __unused int argc, const __unused char **argv)
{
        struct flock fl1, fl2;

        memset(&fl1, 1, sizeof(fl1));
        fl1.l_type = F_WRLCK;
        fl1.l_whence = SEEK_SET;
        fl2 = fl1;

        if (fcntl(fd, F_GETLK, &fl1) < 0)
                err(1, "F_GETLK");

        printf("1 - F_GETLK on unlocked region: ");
        FAIL(fl1.l_start != fl2.l_start);
        FAIL(fl1.l_len != fl2.l_len);
        FAIL(fl1.l_pid != fl2.l_pid);
        FAIL(fl1.l_type != F_UNLCK);
        FAIL(fl1.l_whence != fl2.l_whence);
#ifdef HAVE_SYSID
        FAIL(fl1.l_sysid != fl2.l_sysid);
#endif

        SUCCEED;
}

/*
 * Test 2 - F_SETLK on locked region
 *
 * If a shared or exclusive lock cannot be set, fcntl returns
 * immediately with EACCES or EAGAIN.
 */
static int
test2(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should return -1 with errno set to either EACCES or
         * EAGAIN.
         */
        printf("2 - F_SETLK on locked region: ");
        res = fcntl(fd, F_SETLK, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);
        FAIL(res == 0);
        FAIL(errno != EACCES && errno != EAGAIN);

        SUCCEED;
}

/*
 * Test 3 - F_SETLKW on locked region
 *
 * If a shared or exclusive lock is blocked by other locks, the
 * process waits until the request can be satisfied.
 *
 * XXX this test hangs on FreeBSD NFS filesystems due to limitations
 * in FreeBSD's client (and server) lockd implementation.
 */
static int
test3(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("3 - F_SETLKW on locked region: ");

        alarm(1);

        res = fcntl(fd, F_SETLKW, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);
        FAIL(res == 0);
        FAIL(errno != EINTR);

        SUCCEED;
}

/*
 * Test 4 - F_GETLK on locked region
 *
 * Get the first lock that blocks the lock.
 */
static int
test4(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 99;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should return a lock structure reflecting the lock we
         * made in the child process.
         */
        if (fcntl(fd, F_GETLK, &fl) < 0)
                err(1, "F_GETLK");

        printf("4 - F_GETLK on locked region: ");
        FAIL(fl.l_start != 0);
        FAIL(fl.l_len != 99);
        FAIL(fl.l_type != F_WRLCK);
        FAIL(fl.l_pid != pid);
#ifdef HAVE_SYSID
        FAIL(fl.l_sysid != 0);
#endif

        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        SUCCEED;
}

/*
 * Test 5 - F_SETLKW simple deadlock
 *
 * If a blocking shared lock request would cause a deadlock (i.e. the
 * lock request is blocked by a process which is itself blocked on a
 * lock currently owned by the process making the new request),
 * EDEADLK is returned.
 */
static int
test5(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. Because our test relies on the child process being
         * blocked on the parent's lock, we can't easily use a pipe to
         * synchronize so we just sleep in the parent to given the
         * child a chance to setup.
         *
         * To create the deadlock condition, we arrange for the parent
         * to lock the first byte of the file and the child to lock
         * the second byte.  After locking the second byte, the child
         * will attempt to lock the first byte of the file, and
         * block. The parent will then attempt to lock the second byte
         * (owned by the child) which should cause deadlock.
         */
        int pid;
        struct flock fl;
        int res;

        /*
         * Lock the first byte in the parent.
         */
        fl.l_start = 0;
        fl.l_len = 1;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_SETLK 1 (parent)");

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * Lock the second byte in the child and then block on
                 * the parent's lock.
                 */
                fl.l_start = 1;
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                fl.l_start = 0;
                if (fcntl(fd, F_SETLKW, &fl) < 0)
                        err(1, "F_SETLKW (child)");
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        sleep(1);

        /*
         * fcntl should immediately return -1 with errno set to
         * EDEADLK. If the alarm fires, we failed to detect the
         * deadlock.
         */
        alarm(1);
        printf("5 - F_SETLKW simple deadlock: ");

        fl.l_start = 1;
        res = fcntl(fd, F_SETLKW, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        
        FAIL(res == 0);
        FAIL(errno != EDEADLK);

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_UNLCK;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_UNLCK");

        /*
         * Cancel the alarm to avoid confusing later tests.
         */
        alarm(0);

        SUCCEED;
}

/*
 * Test 6 - F_SETLKW complex deadlock.
 *
 * This test involves three process, P, C1 and C2. We set things up so
 * that P locks byte zero, C1 locks byte 1 and C2 locks byte 2. We
 * also block C2 by attempting to lock byte zero. Lastly, P attempts
 * to lock a range including byte 1 and 2. This represents a deadlock
 * (due to C2's blocking attempt to lock byte zero).
 */
static int
test6(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * Because our test relies on the child process being blocked
         * on the parent's lock, we can't easily use a pipe to
         * synchronize so we just sleep in the parent to given the
         * children a chance to setup.
         */
        int pid1, pid2;
        struct flock fl;
        int res;

        /*
         * Lock the first byte in the parent.
         */
        fl.l_start = 0;
        fl.l_len = 1;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_SETLK 1 (parent)");

        pid1 = fork();
        if (pid1 < 0)
                err(1, "fork");

        if (pid1 == 0) {
                /*
                 * C1
                 * Lock the second byte in the child and then sleep
                 */
                fl.l_start = 1;
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child1)");
                pause();
                exit(0);
        }

        pid2 = fork();
        if (pid2 < 0)
                err(1, "fork");

        if (pid2 == 0) {
                /*
                 * C2
                 * Lock the third byte in the child and then block on
                 * the parent's lock.
                 */
                fl.l_start = 2;
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child2)");
                fl.l_start = 0;
                if (fcntl(fd, F_SETLKW, &fl) < 0)
                        err(1, "F_SETLKW (child2)");
                exit(0);
        }

        /*
         * Wait until the children have set their locks and then
         * perform the test.
         */
        sleep(1);

        /*
         * fcntl should immediately return -1 with errno set to
         * EDEADLK. If the alarm fires, we failed to detect the
         * deadlock.
         */
        alarm(1);
        printf("6 - F_SETLKW complex deadlock: ");

        fl.l_start = 1;
        fl.l_len = 2;
        res = fcntl(fd, F_SETLKW, &fl);
        kill(pid1, SIGTERM);
        safe_waitpid(pid1);
        kill(pid2, SIGTERM);
        safe_waitpid(pid2);

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_UNLCK;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_UNLCK");

        FAIL(res == 0);
        FAIL(errno != EDEADLK);

        /*
         * Cancel the alarm to avoid confusing later tests.
         */
        alarm(0);

        SUCCEED;
}

/*
 * Test 7 - F_SETLK shared lock on exclusive locked region
 *
 * If a shared or exclusive lock cannot be set, fcntl returns
 * immediately with EACCES or EAGAIN.
 */
static int
test7(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("7 - F_SETLK shared lock on exclusive locked region: ");

        fl.l_type = F_RDLCK;
        res = fcntl(fd, F_SETLK, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        FAIL(res == 0);
        FAIL(errno != EACCES && errno != EAGAIN);

        SUCCEED;
}

/*
 * Test 8 - F_SETLK shared lock on share locked region
 *
 * When a shared lock is set on a segment of a file, other processes
 * shall be able to set shared locks on that segment or a portion of
 * it.
 */
static int
test8(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_RDLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("8 - F_SETLK shared lock on share locked region: ");

        fl.l_type = F_RDLCK;
        res = fcntl(fd, F_SETLK, &fl);

        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_UNLCK;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_UNLCK");

        FAIL(res != 0);

        SUCCEED;
}

/*
 * Test 9 - F_SETLK exclusive lock on share locked region
 *
 * If a shared or exclusive lock cannot be set, fcntl returns
 * immediately with EACCES or EAGAIN.
 */
static int
test9(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_RDLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("9 - F_SETLK exclusive lock on share locked region: ");

        fl.l_type = F_WRLCK;
        res = fcntl(fd, F_SETLK, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        FAIL(res == 0);
        FAIL(errno != EACCES && errno != EAGAIN);

        SUCCEED;
}

/*
 * Test 10 - trying to set bogus pid or sysid values
 *
 * The l_pid and l_sysid fields are only used with F_GETLK to return
 * the process ID of the process holding a blocking lock and the
 * system ID of the system that owns that process
 */
static int
test10(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        fl.l_pid = 9999;
#ifdef HAVE_SYSID
        fl.l_sysid = 9999;
#endif

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        printf("10 - trying to set bogus pid or sysid values: ");

        if (fcntl(fd, F_GETLK, &fl) < 0)
                err(1, "F_GETLK");

        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        FAIL(fl.l_pid != pid);
#ifdef HAVE_SYSID
        FAIL(fl.l_sysid != 0);
#endif

        SUCCEED;
}

/*
 * Test 11 - remote locks
 *
 * XXX temporary interface which will be removed when the kernel lockd
 * is added.
 */
static int
test11(int fd, __unused int argc, const __unused char **argv)
{
#ifdef F_SETLK_REMOTE
        struct flock fl;
        int res;

        if (geteuid() != 0)
                return 0;

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        fl.l_pid = 9999;
        fl.l_sysid = 1001;

        printf("11 - remote locks: ");

        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        fl.l_sysid = 1002;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res == 0);
        FAIL(errno != EACCES && errno != EAGAIN);

        res = fcntl(fd, F_GETLK, &fl);
        FAIL(res != 0);
        FAIL(fl.l_pid != 9999);
        FAIL(fl.l_sysid != 1001);

        fl.l_type = F_UNLCK;
        fl.l_sysid = 1001;
        fl.l_start = 0;
        fl.l_len = 0;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        fl.l_pid = 1234;
        fl.l_sysid = 1001;
        fl.l_start = 0;
        fl.l_len = 1;
        fl.l_whence = SEEK_SET;
        fl.l_type = F_RDLCK;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        fl.l_sysid = 1002;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        fl.l_type = F_UNLCKSYS;
        fl.l_sysid = 1001;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        fl.l_type = F_WRLCK;
        res = fcntl(fd, F_GETLK, &fl);
        FAIL(res != 0);
        FAIL(fl.l_pid != 1234);
        FAIL(fl.l_sysid != 1002);

        fl.l_type = F_UNLCKSYS;
        fl.l_sysid = 1002;
        res = fcntl(fd, F_SETLK_REMOTE, &fl);
        FAIL(res != 0);

        SUCCEED;
#else
        return 0;
#endif
}

/*
 * Test 12 - F_SETLKW on locked region which is then unlocked
 *
 * If a shared or exclusive lock is blocked by other locks, the
 * process waits until the request can be satisfied.
 */
static int
test12(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");

                sleep(1);
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("12 - F_SETLKW on locked region which is then unlocked: ");

        //alarm(1);

        res = fcntl(fd, F_SETLKW, &fl);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);
        FAIL(res != 0);

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_UNLCK;
        if (fcntl(fd, F_SETLK, &fl) < 0)
                err(1, "F_UNLCK");

        SUCCEED;
}

/*
 * Test 13 - F_SETLKW on locked region, race with owner
 *
 * If a shared or exclusive lock is blocked by other locks, the
 * process waits until the request can be satisfied.
 */
static int
test13(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int i;
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;
        struct itimerval itv;

        printf("13 - F_SETLKW on locked region, race with owner: ");
        fflush(stdout);

        for (i = 0; i < 100; i++) {
                if (pipe(pfd) < 0)
                        err(1, "pipe");

                fl.l_start = 0;
                fl.l_len = 0;
                fl.l_type = F_WRLCK;
                fl.l_whence = SEEK_SET;

                pid = fork();
                if (pid < 0)
                        err(1, "fork");

                if (pid == 0) {
                        /*
                         * We are the child. We set a write lock and then
                         * write one byte back to the parent to tell it. The
                         * parent will kill us when its done.
                         */
                        if (fcntl(fd, F_SETLK, &fl) < 0)
                                err(1, "F_SETLK (child)");
                        if (write(pfd[1], "a", 1) < 0)
                                err(1, "writing to pipe (child)");

                        usleep(1);
                        exit(0);
                }

                /*
                 * Wait until the child has set its lock and then perform the
                 * test.
                 */
                while (read(pfd[0], &ch, 1) != 1) {
                        if (errno == EINTR)
                                continue;
                        err(1, "reading from pipe (child)");
                }

                /*
                 * fcntl should wait until the alarm and then return -1 with
                 * errno set to EINTR.
                 */
                itv.it_interval.tv_sec = 0;
                itv.it_interval.tv_usec = 0;
                itv.it_value.tv_sec = 0;
                itv.it_value.tv_usec = 2;
                setitimer(ITIMER_REAL, &itv, NULL);

                res = fcntl(fd, F_SETLKW, &fl);
                kill(pid, SIGTERM);
                safe_waitpid(pid);
                close(pfd[0]);
                close(pfd[1]);
                FAIL(!(res == 0 || (res == -1 && errno == EINTR)));

                fl.l_start = 0;
                fl.l_len = 0;
                fl.l_type = F_UNLCK;
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "F_UNLCK");
        }
        SUCCEED;
}

/*
 * Test 14 - soak test
 */
static int
test14(int fd, int argc, const char **argv)
{
#define CHILD_COUNT 20
        /*
         * We create a set of child processes and let each one run
         * through a random sequence of locks and unlocks.
         */
        int i, j, id, id_base;
        int pids[CHILD_COUNT], pid;
        char buf[128];
        char tbuf[128];
        int map[128];
        char outbuf[512];
        struct flock fl;
        struct itimerval itv;
        int status;

        id_base = 0;
        if (argc >= 2)
                id_base = strtol(argv[1], NULL, 0);

        printf("14 - soak test: ");
        fflush(stdout);

        for (i = 0; i < 128; i++)
                map[i] = F_UNLCK;

        for (i = 0; i < CHILD_COUNT; i++) {

                pid = fork();
                if (pid < 0)
                        err(1, "fork");
                if (pid) {
                        /*
                         * Parent - record the pid and continue.
                         */
                        pids[i] = pid;
                        continue;
                }

                /*
                 * Child - do some work and exit.
                 */
                id = id_base + i;
                srandom(getpid());

                for (j = 0; j < 50; j++) {
                        int start, end, len;
                        int set, wrlock;

                        do {
                                start = random() & 127;
                                end = random() & 127;
                        } while (end <= start);

                        set = random() & 1;
                        wrlock = random() & 1;

                        len = end - start;
                        fl.l_start = start;
                        fl.l_len = len;
                        fl.l_whence = SEEK_SET;
                        if (set)
                                fl.l_type = wrlock ? F_WRLCK : F_RDLCK;
                        else
                                fl.l_type = F_UNLCK;

                        itv.it_interval.tv_sec = 0;
                        itv.it_interval.tv_usec = 0;
                        itv.it_value.tv_sec = 0;
                        itv.it_value.tv_usec = 3000;
                        setitimer(ITIMER_REAL, &itv, NULL);

                        if (fcntl(fd, F_SETLKW, &fl) < 0) {
                                if (errno == EDEADLK || errno == EINTR) {
                                        if (verbose) {
                                                snprintf(outbuf, sizeof(outbuf),
                                                    "%d[%d]: %s [%d .. %d] %s\n",
                                                    id, j,
                                                    set ? (wrlock ? "write lock"
                                                        : "read lock")
                                                    : "unlock", start, end,
                                                    errno == EDEADLK
                                                    ? "deadlock"
                                                    : "interrupted");
                                                write(1, outbuf,
                                                    strlen(outbuf));
                                        }
                                        continue;
                                } else {
                                        perror("fcntl");
                                }
                        }

                        itv.it_interval.tv_sec = 0;
                        itv.it_interval.tv_usec = 0;
                        itv.it_value.tv_sec = 0;
                        itv.it_value.tv_usec = 0;
                        setitimer(ITIMER_REAL, &itv, NULL);

                        if (verbose) {
                                snprintf(outbuf, sizeof(outbuf),
                                    "%d[%d]: %s [%d .. %d] succeeded\n",
                                    id, j,
                                    set ? (wrlock ? "write lock" : "read lock")
                                    : "unlock", start, end);
                                write(1, outbuf, strlen(outbuf));
                        }

                        if (set) {
                                if (wrlock) {
                                        /*
                                         * We got a write lock - write
                                         * our ID to each byte that we
                                         * managed to claim.
                                         */
                                        for (i = start; i < end; i++)
                                                map[i] = F_WRLCK;
                                        memset(&buf[start], id, len);
                                        if (pwrite(fd, &buf[start], len,
                                                start) != len) {
                                                printf("%d: short write\n", id);
                                                exit(1);
                                        }
                                } else {
                                        /*
                                         * We got a read lock - read
                                         * the bytes which we claimed
                                         * so that we can check that
                                         * they don't change
                                         * unexpectedly.
                                         */
                                        for (i = start; i < end; i++)
                                                map[i] = F_RDLCK;
                                        if (pread(fd, &buf[start], len,
                                                start) != len) {
                                                printf("%d: short read\n", id);
                                                exit(1);
                                        }
                                }
                        } else {
                                for (i = start; i < end; i++)
                                        map[i] = F_UNLCK;
                        }

                        usleep(1000);

                        /*
                         * Read back the whole region so that we can
                         * check that all the bytes we have some kind
                         * of claim to have the correct value.
                         */
                        if (pread(fd, tbuf, sizeof(tbuf), 0) != sizeof(tbuf)) {
                                printf("%d: short read\n", id);
                                exit(1);
                        }

                        for (i = 0; i < 128; i++) {
                                if (map[i] != F_UNLCK && buf[i] != tbuf[i]) {
                                        snprintf(outbuf, sizeof(outbuf),
                                            "%d: byte %d expected %d, "
                                            "got %d\n", id, i, buf[i], tbuf[i]);
                                        write(1, outbuf, strlen(outbuf));
                                        exit(1);
                                }
                        }
                }
                if (verbose)
                        printf("%d[%d]: done\n", id, j);

                exit(0);
        }

        status = 0;
        for (i = 0; i < CHILD_COUNT; i++) {
                status += safe_waitpid(pids[i]);
        }
        if (status)
                FAIL(status != 0);

        SUCCEED;
}

/*
 * Test 15 - flock(2) semantcs
 *
 * When a lock holder has a shared lock and attempts to upgrade that
 * shared lock to exclusive, it must drop the shared lock before
 * blocking on the exclusive lock.
 *
 * To test this, we first arrange for two shared locks on the file,
 * and then attempt to upgrade one of them to exclusive. This should
 * drop one of the shared locks and block. We interrupt the blocking
 * lock request and examine the lock state of the file after dropping
 * the other shared lock - there should be no active locks at this
 * point.
 */
static int
test15(int fd, __unused int argc, const __unused char **argv)
{
#ifdef LOCK_EX
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         *
         * Since we only have one file descriptors and lock ownership
         * for flock(2) goes with the file descriptor, we use fcntl to
         * set the child's shared lock.
         */
        int pid;
        int pfd[2];
        struct flock fl;
        char ch;
        int res;

        if (pipe(pfd) < 0)
                err(1, "pipe");

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a shared lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                fl.l_start = 0;
                fl.l_len = 0;
                fl.l_type = F_RDLCK;
                fl.l_whence = SEEK_SET;
                if (fcntl(fd, F_SETLK, &fl) < 0)
                        err(1, "fcntl(F_SETLK) (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        (void)dup(fd);
        if (flock(fd, LOCK_SH) < 0)
                err(1, "flock shared");

        /*
         * flock should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("15 - flock(2) semantics: ");

        alarm(1);
        flock(fd, LOCK_EX);

        /*
         * Kill the child to force it to drop its locks.
         */
        kill(pid, SIGTERM);
        safe_waitpid(pid);

        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        res = fcntl(fd, F_GETLK, &fl);

        close(pfd[0]);
        close(pfd[1]);
        FAIL(res != 0);
        FAIL(fl.l_type != F_UNLCK);

        SUCCEED;
#else
        return 0;
#endif
}

struct test_ctx {
        struct flock tc_fl;
        int tc_fd;
};

static void *
test16_func(void *tc_in)
{
        uintptr_t error;
        struct test_ctx *tc = tc_in;

        error = fcntl(tc->tc_fd, F_SETLKW, &tc->tc_fl);

        pthread_exit((void *)error);
}

#define THREADS 10

/*
 * Test 16 - F_SETLKW from two threads
 *
 * If two threads within a process are blocked on a lock and the lock
 * is granted, make sure things are sane.
 */
static int
test16(int fd, __unused int argc, const __unused char **argv)
{
        /*
         * We create a child process to hold the lock which we will
         * test. We use a pipe to communicate with the child.
         */
        int pid;
        int pfd[2];
        struct test_ctx tc = { .tc_fd = fd };
        char ch;
        int i;
        int error;
        pthread_t thr[THREADS];

        if (pipe(pfd) < 0)
                err(1, "pipe");

        tc.tc_fl.l_start = 0;
        tc.tc_fl.l_len = 0;
        tc.tc_fl.l_type = F_WRLCK;
        tc.tc_fl.l_whence = SEEK_SET;

        pid = fork();
        if (pid < 0)
                err(1, "fork");

        if (pid == 0) {
                /*
                 * We are the child. We set a write lock and then
                 * write one byte back to the parent to tell it. The
                 * parent will kill us when its done.
                 */
                if (fcntl(fd, F_SETLK, &tc.tc_fl) < 0)
                        err(1, "F_SETLK (child)");
                if (write(pfd[1], "a", 1) < 0)
                        err(1, "writing to pipe (child)");
                pause();
                exit(0);
        }

        /*
         * Wait until the child has set its lock and then perform the
         * test.
         */
        if (read(pfd[0], &ch, 1) != 1)
                err(1, "reading from pipe (child)");

        /*
         * fcntl should wait until the alarm and then return -1 with
         * errno set to EINTR.
         */
        printf("16 - F_SETLKW on locked region by two threads: ");

        for (i = 0; i < THREADS; i++) {
                error = pthread_create(&thr[i], NULL, test16_func, &tc);
                if (error)
                        err(1, "pthread_create");
        }

        /*
         * Sleep, then kill the child. This makes me a little sad, but it's
         * tricky to tell whether the threads are all really blocked by this
         * point.
         */
        sleep(1);
        kill(pid, SIGTERM);
        safe_waitpid(pid);
        close(pfd[0]);
        close(pfd[1]);

        for (i = 0; i < THREADS; i++) {
                void *res;
                error = pthread_join(thr[i], &res);
                if (error)
                        err(1, "pthread_join");
                FAIL((uintptr_t)res != 0);
        }

        SUCCEED;
}

struct test {
        int (*testfn)(int, int, const char **); /* function to perform the test */
        int num;                /* test number */
        int intr;               /* non-zero if the test interrupts a lock */
};

static struct test tests[] = {
        {       test1,          1,      0       },
        {       test2,          2,      0       },
        {       test3,          3,      1       },
        {       test4,          4,      0       },
        {       test5,          5,      1       },
        {       test6,          6,      1       },
        {       test7,          7,      0       },
        {       test8,          8,      0       },
        {       test9,          9,      0       },
        {       test10,         10,     0       },
        {       test11,         11,     1       },
        {       test12,         12,     0       },
        {       test13,         13,     1       },
        {       test14,         14,     0       },
        {       test15,         15,     1       },
        {       test16,         16,     1       },
};

int
main(int argc, const char *argv[])
{
        int testnum;
        int fd;
        int nointr;
        unsigned i;
        struct sigaction sa;
        int test_argc;
        const char **test_argv;

        if (argc < 2) {
                errx(1, "usage: flock <directory> [test number] ...");
        }

        fd = make_file(argv[1], 1024);
        if (argc >= 3) {
                testnum = strtol(argv[2], NULL, 0);
                test_argc = argc - 2;
                test_argv = argv + 2;
        } else {
                testnum = 0;
                test_argc = 0;
                test_argv = NULL;
        }

        sa.sa_handler = ignore_alarm;
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = 0;
        sigaction(SIGALRM, &sa, 0);

        nointr = 0;
#if defined(__FreeBSD__) && __FreeBSD_version < 800040
        {
                /*
                 * FreeBSD with userland NLM can't interrupt a blocked
                 * lock request on an NFS mounted filesystem.
                 */
                struct statfs st;
                fstatfs(fd, &st);
                nointr = !strcmp(st.f_fstypename, "nfs");
        }
#endif

        for (i = 0; i < nitems(tests); i++) {
                if (tests[i].intr && nointr)
                        continue;
                if (!testnum || tests[i].num == testnum)
                        tests[i].testfn(fd, test_argc, test_argv);
        }

        return 0;
}