/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019 The FreeBSD Foundation
 *
 * This software was developed by BFF Storage Systems, LLC under sponsorship
 * from the FreeBSD Foundation.
 *
 * 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.
 */

extern "C" {
#include <sys/socket.h>
#include <sys/un.h>

#include <fcntl.h>
#include <unistd.h>
}

#include "mockfs.hh"
#include "utils.hh"

using namespace testing;

class Release: public FuseTest {

public:
void expect_lookup(const char *relpath, uint64_t ino, int times)
{
        FuseTest::expect_lookup(relpath, ino, S_IFREG | 0644, 0, times);
}

void expect_release(uint64_t ino, uint64_t lock_owner,
        uint32_t flags, int error)
{
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_RELEASE &&
                                in.header.nodeid == ino &&
                                in.body.release.lock_owner == lock_owner &&
                                in.body.release.fh == FH &&
                                in.body.release.flags == flags);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(error)))
        .RetiresOnSaturation();
}
};

class ReleaseWithLocks: public Release {
        virtual void SetUp() {
                m_init_flags = FUSE_POSIX_LOCKS;
                Release::SetUp();
        }
};


/* If a file descriptor is duplicated, only the last close causes RELEASE */
TEST_F(Release, dup)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd, fd2;

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, getpid(), O_RDONLY, 0);
        
        fd = open(FULLPATH, O_RDONLY);
        ASSERT_LE(0, fd) << strerror(errno);

        fd2 = dup(fd);
        ASSERT_LE(0, fd2) << strerror(errno);

        ASSERT_EQ(0, close(fd2)) << strerror(errno);
        ASSERT_EQ(0, close(fd)) << strerror(errno);
}

/* 
 * Some FUSE filesystem cache data internally and flush it on release.  Such
 * filesystems may generate errors during release.  On Linux, these get
 * returned by close(2).  However, POSIX does not require close(2) to return
 * this error.  FreeBSD's fuse(4) should return EIO if it returns an error at
 * all.
 */
/* http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html */
TEST_F(Release, eio)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd;

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, getpid(), O_WRONLY, EIO);
        
        fd = open(FULLPATH, O_WRONLY);
        ASSERT_LE(0, fd) << strerror(errno);

        ASSERT_TRUE(0 == close(fd) || errno == EIO) << strerror(errno);
}

/*
 * FUSE_RELEASE should contain the same flags used for FUSE_OPEN
 */
/* https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236340 */
TEST_F(Release, DISABLED_flags)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd;

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, getpid(), O_RDWR | O_APPEND, 0);
        
        fd = open(FULLPATH, O_RDWR | O_APPEND);
        ASSERT_LE(0, fd) << strerror(errno);

        ASSERT_EQ(0, close(fd)) << strerror(errno);
}

/*
 * fuse(4) will issue multiple FUSE_OPEN operations for the same file if it's
 * opened with different modes.  Each FUSE_OPEN should get its own
 * FUSE_RELEASE.
 */
TEST_F(Release, multiple_opens)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd, fd2;

        expect_lookup(RELPATH, ino, 2);
        expect_open(ino, 0, 2);
        expect_flush(ino, 2, ReturnErrno(0));
        expect_release(ino, getpid(), O_RDONLY, 0);
        
        fd = open(FULLPATH, O_RDONLY);
        ASSERT_LE(0, fd) << strerror(errno);

        expect_release(ino, getpid(), O_WRONLY, 0);
        fd2 = open(FULLPATH, O_WRONLY);
        ASSERT_LE(0, fd2) << strerror(errno);

        ASSERT_EQ(0, close(fd2)) << strerror(errno);
        ASSERT_EQ(0, close(fd)) << strerror(errno);
}

TEST_F(Release, ok)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd;

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, getpid(), O_RDONLY, 0);
        
        fd = open(FULLPATH, O_RDONLY);
        ASSERT_LE(0, fd) << strerror(errno);

        ASSERT_EQ(0, close(fd)) << strerror(errno);
}

/*
 * Nothing bad should happen when closing a Unix-domain named socket that
 * contains a fusefs file descriptor within its receive buffer.
 * Regression test for
 * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=289686
 */
TEST_F(Release, scm_rights)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        struct msghdr msg;
        struct iovec iov;
        char message[CMSG_SPACE(sizeof(int))];
        uint64_t ino = 42;
        int fd;
        int s[2];
        union {
                char buf[CMSG_SPACE(sizeof(fd))];
                struct cmsghdr align;
        } u;

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, getpid(), O_RDONLY, 0);

        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM, 0, s)) << strerror(errno);

        fd = open(FULLPATH, O_RDONLY);
        ASSERT_LE(0, fd) << strerror(errno);

        memset(&message, 0, sizeof(message));
        memset(&msg, 0, sizeof(msg));
        iov.iov_base = NULL;
        iov.iov_len = 0;
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
        msg.msg_control = u.buf,
        msg.msg_controllen = sizeof(u.buf);
        struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
        cmsg->cmsg_level = SOL_SOCKET;
        cmsg->cmsg_type = SCM_RIGHTS;
        cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
        memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
        ASSERT_GE(sendmsg(s[0], &msg, 0), 0) << strerror(errno);

        close(fd);      // Close fd within our process
        close(s[0]);
        close(s[1]);    // The last copy of fd is within this socket's rcvbuf
}

/* When closing a file with a POSIX file lock, release should release the lock*/
TEST_F(ReleaseWithLocks, unlock_on_close)
{
        const char FULLPATH[] = "mountpoint/some_file.txt";
        const char RELPATH[] = "some_file.txt";
        uint64_t ino = 42;
        int fd;
        struct flock fl;
        pid_t pid = getpid();

        expect_lookup(RELPATH, ino, 1);
        expect_open(ino, 0, 1);
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_SETLK &&
                                in.header.nodeid == ino &&
                                in.body.setlk.lk.type == F_RDLCK &&
                                in.body.setlk.fh == FH);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_SETLK &&
                                in.header.nodeid == ino &&
                                in.body.setlk.lk.type == F_UNLCK &&
                                in.body.setlk.fh == FH);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));
        expect_flush(ino, 1, ReturnErrno(0));
        expect_release(ino, static_cast<uint64_t>(pid), O_RDWR, 0);

        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);
        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_pid = pid;
        fl.l_type = F_RDLCK;
        fl.l_whence = SEEK_SET;
        fl.l_sysid = 0;
        ASSERT_NE(-1, fcntl(fd, F_SETLK, &fl)) << strerror(errno);

        ASSERT_EQ(0, close(fd)) << strerror(errno);
}