/*
 * Copyright (c) 2009 Mark Heily <mark@heily.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "common.h"

/* Create an empty file */
static void
testfile_create(const char *path)
{
    int fd;

    if ((fd = open(path, O_CREAT | O_WRONLY, 0600)) < 0)
        die("open");
    close(fd);
}

static void
testfile_touch(const char *path)
{
    char buf[1024];

    snprintf(buf, sizeof(buf), "touch %s", path);
    if (system(buf) != 0)
        die("system");
}

static void
testfile_write(const char *path)
{
    char buf[1024];

    snprintf(buf, sizeof(buf), "echo hi >> %s", path);
    if (system(buf) != 0)
        die("system");
}

static void
testfile_rename(const char *path, int step)
{
    char buf[1024];

    snprintf(buf, sizeof(buf), "%s.tmp", path);
    /* XXX-FIXME use of 'step' conceals a major memory corruption
            when the file is renamed twice.
            To replicate, remove "if step" conditional so
            two renames occur in this function.
            */
    if (step == 0) {
        if (rename(path, buf) != 0)
            err(1,"rename");
    } else {
        if (rename(buf, path) != 0)
            err(1,"rename");
    }
}

void
test_kevent_vnode_add(struct test_context *ctx)
{
    struct kevent kev;

    testfile_create(ctx->testfile);

    ctx->vnode_fd = open(ctx->testfile, O_RDWR);
    if (ctx->vnode_fd < 0)
        err(1, "open of %s", ctx->testfile);

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD,
            NOTE_WRITE | NOTE_ATTRIB | NOTE_RENAME | NOTE_DELETE, 0, NULL);
}

void
test_kevent_vnode_note_delete(struct test_context *ctx)
{
    struct kevent kev, ret[1];

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_DELETE, 0, NULL);

    if (unlink(ctx->testfile) < 0)
        die("unlink");

    kevent_get(ret, NUM_ELEMENTS(ret), ctx->kqfd, 1);

    /*
     *  FIXME - macOS 11.5.2 also sets NOTE_LINK.
     *  This seems redundant, but behaviour should be
     *  checked on FreeBSD/OpenBSD to determine the
     *  correct behaviour for libkqueue.
     */
#ifdef __APPLE__
    kev.fflags |= NOTE_LINK;
#endif

    kevent_cmp(&kev, ret);
}

void
test_kevent_vnode_note_write(struct test_context *ctx)
{
    struct kevent kev, ret[1];

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_WRITE, 0, NULL);

    testfile_write(ctx->testfile);

    /*
     * macOS 11.5.2 does not add NOTE_EXTEND,
     * BSD kqueue does, as does libkqueue.
     */
#ifndef __APPLE__
    kev.fflags |= NOTE_EXTEND;
#endif
    kevent_get(ret, NUM_ELEMENTS(ret), ctx->kqfd, 1);
    kevent_cmp(&kev, ret);
}

void
test_kevent_vnode_note_attrib(struct test_context *ctx)
{
    struct kevent kev;

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_ATTRIB, 0, NULL);

    testfile_touch(ctx->testfile);

    kevent_rv_cmp(1, kevent(ctx->kqfd, NULL, 0, &kev, 1, NULL));
    if (kev.ident != ctx->vnode_fd ||
            kev.filter != EVFILT_VNODE ||
            kev.fflags != NOTE_ATTRIB)
        err(1, "%s - incorrect event (sig=%u; filt=%d; flags=%d)",
                ctx->cur_test_id, (unsigned int)kev.ident, kev.filter, kev.flags);
}

void
test_kevent_vnode_note_rename(struct test_context *ctx)
{
    struct kevent kev;

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_RENAME, 0, NULL);

    testfile_rename(ctx->testfile, 0);

    kevent_rv_cmp(1, kevent(ctx->kqfd, NULL, 0, &kev, 1, NULL));
    if (kev.ident != ctx->vnode_fd ||
            kev.filter != EVFILT_VNODE ||
            kev.fflags != NOTE_RENAME)
        err(1, "%s - incorrect event (sig=%u; filt=%d; flags=%d)",
                ctx->cur_test_id, (unsigned int)kev.ident, kev.filter, kev.flags);

    testfile_rename(ctx->testfile, 1);

    test_no_kevents(ctx->kqfd);
}

void
test_kevent_vnode_del(struct test_context *ctx)
{
    struct kevent kev;

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_DELETE, 0, 0, NULL);
}

void
test_kevent_vnode_disable_and_enable(struct test_context *ctx)
{
    struct kevent kev;

    test_no_kevents(ctx->kqfd);

    /* Add the watch and immediately disable it */
    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_ATTRIB, 0, NULL);
    kev.flags = EV_DISABLE;
    kevent_update(ctx->kqfd, &kev);

    /* Confirm that the watch is disabled */
    testfile_touch(ctx->testfile);
    test_no_kevents(ctx->kqfd);

    /* Re-enable and check again */
    kev.flags = EV_ENABLE;
    kevent_update(ctx->kqfd, &kev);
    testfile_touch(ctx->testfile);
    kevent_rv_cmp(1, kevent(ctx->kqfd, NULL, 0, &kev, 1, NULL));
    if (kev.ident != ctx->vnode_fd ||
            kev.filter != EVFILT_VNODE ||
            kev.fflags != NOTE_ATTRIB)
        err(1, "%s - incorrect event (sig=%u; filt=%d; flags=%d)",
                ctx->cur_test_id, (unsigned int)kev.ident, kev.filter, kev.flags);
}

#ifdef EV_DISPATCH
void
test_kevent_vnode_dispatch(struct test_context *ctx)
{
    struct kevent kev, ret[1];

    test_no_kevents(ctx->kqfd);

    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ADD | EV_DISPATCH, NOTE_ATTRIB, 0, NULL);

    testfile_touch(ctx->testfile);

    kevent_rv_cmp(1, kevent(ctx->kqfd, NULL, 0, &kev, 1, NULL));
    if (kev.ident != ctx->vnode_fd ||
            kev.filter != EVFILT_VNODE ||
            kev.fflags != NOTE_ATTRIB)
        err(1, "%s - incorrect event (sig=%u; filt=%d; flags=%d)",
                ctx->cur_test_id, (unsigned int)kev.ident, kev.filter, kev.flags);

    /* Confirm that the watch is disabled automatically */
    testfile_touch(ctx->testfile);
    test_no_kevents(ctx->kqfd);

    /* Re-enable the kevent */
    /* FIXME- is EV_DISPATCH needed when rearming ? */
    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_ENABLE | EV_DISPATCH, 0, 0, NULL);
    kev.flags = EV_ADD | EV_DISPATCH;   /* FIXME: may not be portable */
    kev.fflags = NOTE_ATTRIB;
    testfile_touch(ctx->testfile);
    kevent_get(ret, NUM_ELEMENTS(ret), ctx->kqfd, 1);
    kevent_cmp(&kev, ret);
    test_no_kevents(ctx->kqfd);

    /* Delete the watch */
    kevent_add(ctx->kqfd, &kev, ctx->vnode_fd, EVFILT_VNODE, EV_DELETE, NOTE_ATTRIB, 0, NULL);
}
#endif     /* EV_DISPATCH */

void
test_evfilt_vnode(struct test_context *ctx)
{
#if (defined(__sun) && !defined(HAVE_PORT_SOURCE_FILE))
    puts("**NOTE** EVFILT_VNODE is not supported on this version of Solaris");
    return;
#endif

    char *tmpdir = getenv("TMPDIR");
    if (tmpdir == NULL)
#ifdef __ANDROID__
        tmpdir = "/data/local/tmp";
#else
        tmpdir = "/tmp";
#endif

    snprintf(ctx->testfile, sizeof(ctx->testfile), "%s/kqueue-test%d.tmp",
            tmpdir, testing_make_uid());

    test(kevent_vnode_add, ctx);
    test(kevent_vnode_del, ctx);
    test(kevent_vnode_disable_and_enable, ctx);
#ifdef EV_DISPATCH
    test(kevent_vnode_dispatch, ctx);
#endif
    test(kevent_vnode_note_write, ctx);
    test(kevent_vnode_note_attrib, ctx);
    test(kevent_vnode_note_rename, ctx);
    test(kevent_vnode_note_delete, ctx);
    /* TODO: test r590 corner case where a descriptor is closed and
             the associated knote is automatically freed. */
    unlink(ctx->testfile);
    close(ctx->vnode_fd);
    ctx->vnode_fd = -1;
}