/*-
 * 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 <stdlib.h>
#include <unistd.h>
}

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

using namespace testing;

class Rename: public FuseTest {
        public:
        int tmpfd = -1;
        char tmpfile[80] = "/tmp/fuse.rename.XXXXXX";

        virtual void TearDown() {
                if (tmpfd >= 0) {
                        close(tmpfd);
                        unlink(tmpfile);
                }

                FuseTest::TearDown();
        }
};

// EINVAL, dst is subdir of src
TEST_F(Rename, einval)
{
        const char FULLDST[] = "mountpoint/src/dst";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        uint64_t src_ino = 42;

        expect_lookup(RELSRC, src_ino, S_IFDIR | 0755, 0, 2);
        EXPECT_LOOKUP(src_ino, RELDST).WillOnce(Invoke(ReturnErrno(ENOENT)));

        ASSERT_NE(0, rename(FULLSRC, FULLDST));
        ASSERT_EQ(EINVAL, errno);
}

// source does not exist
TEST_F(Rename, enoent)
{
        const char FULLDST[] = "mountpoint/dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        // FUSE hardcodes the mountpoint to inode 1

        EXPECT_LOOKUP(FUSE_ROOT_ID, RELSRC)
        .WillOnce(Invoke(ReturnErrno(ENOENT)));

        ASSERT_NE(0, rename(FULLSRC, FULLDST));
        ASSERT_EQ(ENOENT, errno);
}

/*
 * Renaming a file after FUSE_LOOKUP returned a negative cache entry for dst
 */
TEST_F(Rename, entry_cache_negative)
{
        const char FULLDST[] = "mountpoint/dst";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        uint64_t dst_dir_ino = FUSE_ROOT_ID;
        uint64_t ino = 42;
        /* 
         * Set entry_valid = 0 because this test isn't concerned with whether
         * or not we actually cache negative entries, only with whether we
         * interpret negative cache responses correctly.
         */
        struct timespec entry_valid = {.tv_sec = 0, .tv_nsec = 0};

        expect_lookup(RELSRC, ino, S_IFREG | 0644, 0, 1);
        /* LOOKUP returns a negative cache entry for dst */
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDST)
        .WillOnce(ReturnNegativeCache(&entry_valid));

        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        const char *src = (const char*)in.body.bytes +
                                sizeof(fuse_rename_in);
                        const char *dst = src + strlen(src) + 1;
                        return (in.header.opcode == FUSE_RENAME &&
                                in.body.rename.newdir == dst_dir_ino &&
                                (0 == strcmp(RELDST, dst)) &&
                                (0 == strcmp(RELSRC, src)));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));

        ASSERT_EQ(0, rename(FULLSRC, FULLDST)) << strerror(errno);
}

/*
 * Renaming a file should purge any negative namecache entries for the dst
 */
TEST_F(Rename, entry_cache_negative_purge)
{
        const char FULLDST[] = "mountpoint/dst";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        uint64_t dst_dir_ino = FUSE_ROOT_ID;
        uint64_t ino = 42;
        struct timespec entry_valid = {.tv_sec = TIME_T_MAX, .tv_nsec = 0};

        expect_lookup(RELSRC, ino, S_IFREG | 0644, 0, 1);
        /* LOOKUP returns a negative cache entry for dst */
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDST)
        .WillOnce(ReturnNegativeCache(&entry_valid))
        .RetiresOnSaturation();

        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        const char *src = (const char*)in.body.bytes +
                                sizeof(fuse_rename_in);
                        const char *dst = src + strlen(src) + 1;
                        return (in.header.opcode == FUSE_RENAME &&
                                in.body.rename.newdir == dst_dir_ino &&
                                (0 == strcmp(RELDST, dst)) &&
                                (0 == strcmp(RELSRC, src)));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));

        ASSERT_EQ(0, rename(FULLSRC, FULLDST)) << strerror(errno);

        /* Finally, a subsequent lookup should query the daemon */
        expect_lookup(RELDST, ino, S_IFREG | 0644, 0, 1);

        ASSERT_EQ(0, access(FULLDST, F_OK)) << strerror(errno);
}

static volatile int stopit = 0;

static void* setattr_th(void* arg) {
        char *path = (char*)arg;

        while (stopit == 0)
                 chmod(path, 0777);
        return 0;
}

/*
 * Rename restarts the syscall to avoid a LOR
 *
 * This test triggers a race: the chmod() calls VOP_SETATTR, which locks its
 * vnode, but fuse_vnop_rename also tries to lock the same vnode.  The result
 * is that, in order to avoid a LOR, fuse_vnop_rename returns ERELOOKUP to
 * restart the syscall.
 *
 * To verify that the race is hit, watch the fusefs:fusefs:vnops:erelookup
 * dtrace probe while the test is running.  On my system, that probe fires more
 * than 100 times per second during this test.
 */
TEST_F(Rename, erelookup)
{
        const char FULLDST[] = "mountpoint/dstdir/dst";
        const char RELDSTDIR[] = "dstdir";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        pthread_t th0;
        uint64_t ino = 42;
        uint64_t dst_dir_ino = 43;
        uint32_t mode = S_IFDIR | 0644;
        struct timespec now, timeout;

        EXPECT_LOOKUP(FUSE_ROOT_ID, RELSRC)
        .WillRepeatedly(Invoke(
                ReturnImmediate([=](auto i __unused, auto& out) {
                        SET_OUT_HEADER_LEN(out, entry);
                        out.body.entry.attr.mode = mode;
                        out.body.entry.nodeid = ino;
                        out.body.entry.attr.nlink = 2;
                        out.body.entry.attr_valid = UINT64_MAX;
                        out.body.entry.attr.uid = 0;
                        out.body.entry.attr.gid = 0;
                        out.body.entry.entry_valid = UINT64_MAX;
                }))
        );
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDSTDIR)
        .WillRepeatedly(Invoke(ReturnImmediate([=](auto in __unused, auto& out)
        {
                SET_OUT_HEADER_LEN(out, entry);
                out.body.entry.nodeid = dst_dir_ino;
                out.body.entry.entry_valid = UINT64_MAX;
                out.body.entry.attr_valid = UINT64_MAX;
                out.body.entry.attr.mode = S_IFDIR | 0755;
                out.body.entry.attr.ino = dst_dir_ino;
                out.body.entry.attr.uid = geteuid();
                out.body.entry.attr.gid = getegid();
        })));
        EXPECT_LOOKUP(dst_dir_ino, RELDST)
        .WillRepeatedly(Invoke(ReturnErrno(ENOENT)));
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_SETATTR &&
                                in.header.nodeid == ino);
                }, Eq(true)),
                _)
        ).WillRepeatedly(Invoke(ReturnErrno(EIO)));
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_RENAME);
                }, Eq(true)),
                _)
        ).WillRepeatedly(Invoke(ReturnErrno(EIO)));

        ASSERT_EQ(0, pthread_create(&th0, NULL, setattr_th, (void*)FULLSRC))
                << strerror(errno);

        ASSERT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &timeout));
        timeout.tv_nsec += NAP_NS;
        do {
                ASSERT_EQ(-1, rename(FULLSRC, FULLDST));
                EXPECT_EQ(EIO, errno);
                ASSERT_EQ(0, clock_gettime(CLOCK_MONOTONIC, &now));
        } while (timespeccmp(&now, &timeout, <));
        stopit = 1;
        pthread_join(th0, NULL);
}

TEST_F(Rename, exdev)
{
        const char FULLB[] = "mountpoint/src";
        const char RELB[] = "src";
        // FUSE hardcodes the mountpoint to inode 1
        uint64_t b_ino = 42;

        tmpfd = mkstemp(tmpfile);
        ASSERT_LE(0, tmpfd) << strerror(errno);

        expect_lookup(RELB, b_ino, S_IFREG | 0644, 0, 2);

        ASSERT_NE(0, rename(tmpfile, FULLB));
        ASSERT_EQ(EXDEV, errno);

        ASSERT_NE(0, rename(FULLB, tmpfile));
        ASSERT_EQ(EXDEV, errno);
}

TEST_F(Rename, ok)
{
        const char FULLDST[] = "mountpoint/dst";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        uint64_t dst_dir_ino = FUSE_ROOT_ID;
        uint64_t ino = 42;

        expect_lookup(RELSRC, ino, S_IFREG | 0644, 0, 1);
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDST)
        .WillOnce(Invoke(ReturnErrno(ENOENT)));

        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        const char *src = (const char*)in.body.bytes +
                                sizeof(fuse_rename_in);
                        const char *dst = src + strlen(src) + 1;
                        return (in.header.opcode == FUSE_RENAME &&
                                in.body.rename.newdir == dst_dir_ino &&
                                (0 == strcmp(RELDST, dst)) &&
                                (0 == strcmp(RELSRC, src)));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));

        ASSERT_EQ(0, rename(FULLSRC, FULLDST)) << strerror(errno);
}

/* When moving a file to a new directory, update its parent */
TEST_F(Rename, parent)
{
        const char FULLDST[] = "mountpoint/dstdir/dst";
        const char RELDSTDIR[] = "dstdir";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        const char FULLDSTPARENT[] = "mountpoint/dstdir";
        const char FULLDSTDOTDOT[] = "mountpoint/dstdir/dst/..";
        Sequence seq;
        uint64_t dst_dir_ino = 43;
        uint64_t ino = 42;
        struct stat sb;

        expect_lookup(RELSRC, ino, S_IFDIR | 0755, 0, 1);
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDSTDIR)
        .WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, entry);
                out.body.entry.nodeid = dst_dir_ino;
                out.body.entry.entry_valid = UINT64_MAX;
                out.body.entry.attr_valid = UINT64_MAX;
                out.body.entry.attr.mode = S_IFDIR | 0755;
                out.body.entry.attr.ino = dst_dir_ino;
                out.body.entry.attr.nlink = 2;
        })));
        EXPECT_LOOKUP(dst_dir_ino, RELDST)
        .InSequence(seq)
        .WillOnce(Invoke(ReturnErrno(ENOENT)));
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        const char *src = (const char*)in.body.bytes +
                                sizeof(fuse_rename_in);
                        const char *dst = src + strlen(src) + 1;
                        return (in.header.opcode == FUSE_RENAME &&
                                in.body.rename.newdir == dst_dir_ino &&
                                (0 == strcmp(RELDST, dst)) &&
                                (0 == strcmp(RELSRC, src)));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));
        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_GETATTR &&
                                in.header.nodeid == 1);
                }, Eq(true)),
                _)
        ).InSequence(seq)
        .WillOnce(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, attr);
                out.body.attr.attr_valid = UINT64_MAX;
                out.body.attr.attr.ino = 1;
                out.body.attr.attr.mode = S_IFDIR | 0755;
                out.body.attr.attr.nlink = 2;
        })));
        EXPECT_LOOKUP(FUSE_ROOT_ID, RELDSTDIR)
        .InSequence(seq)
        .WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, entry);
                out.body.entry.nodeid = dst_dir_ino;
                out.body.entry.entry_valid = UINT64_MAX;
                out.body.entry.attr_valid = UINT64_MAX;
                out.body.entry.attr.mode = S_IFDIR | 0755;
                out.body.entry.attr.ino = dst_dir_ino;
                out.body.entry.attr.nlink = 3;
        })));
        EXPECT_LOOKUP(dst_dir_ino, RELDST)
        .InSequence(seq)
        .WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, entry);
                out.body.entry.attr.mode = S_IFDIR | 0755;
                out.body.entry.nodeid = ino;
                out.body.entry.entry_valid = UINT64_MAX;
                out.body.entry.attr_valid = UINT64_MAX;
        })));

        ASSERT_EQ(0, rename(FULLSRC, FULLDST)) << strerror(errno);

        ASSERT_EQ(0, stat("mountpoint", &sb)) << strerror(errno);
        EXPECT_EQ(2ul, sb.st_nlink);

        ASSERT_EQ(0, stat(FULLDSTPARENT, &sb)) << strerror(errno);
        EXPECT_EQ(3ul, sb.st_nlink);

        ASSERT_EQ(0, stat(FULLDSTDOTDOT, &sb)) << strerror(errno);
        ASSERT_EQ(dst_dir_ino, sb.st_ino);
}

// Rename overwrites an existing destination file
TEST_F(Rename, overwrite)
{
        const char FULLDST[] = "mountpoint/dst";
        const char RELDST[] = "dst";
        const char FULLSRC[] = "mountpoint/src";
        const char RELSRC[] = "src";
        // The inode of the already-existing destination file
        uint64_t dst_ino = 2;
        uint64_t dst_dir_ino = FUSE_ROOT_ID;
        uint64_t ino = 42;

        expect_lookup(RELSRC, ino, S_IFREG | 0644, 0, 1);
        expect_lookup(RELDST, dst_ino, S_IFREG | 0644, 0, 1);
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        const char *src = (const char*)in.body.bytes +
                                sizeof(fuse_rename_in);
                        const char *dst = src + strlen(src) + 1;
                        return (in.header.opcode == FUSE_RENAME &&
                                in.body.rename.newdir == dst_dir_ino &&
                                (0 == strcmp(RELDST, dst)) &&
                                (0 == strcmp(RELSRC, src)));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(0)));

        ASSERT_EQ(0, rename(FULLSRC, FULLDST)) << strerror(errno);
}