/*      $NetBSD: t_basic.c,v 1.6 2024/07/28 12:55:59 bad Exp $  */

#include <sys/types.h>
#include <sys/mount.h>

#include <atf-c.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#include <rump/rump.h>
#include <rump/rump_syscalls.h>

#include <miscfs/nullfs/null.h>
#include <fs/tmpfs/tmpfs_args.h>

#include "h_macros.h"

ATF_TC(basic);
ATF_TC_HEAD(basic, tc)
{
        atf_tc_set_md_var(tc, "descr", "basic nullfs functionality");
}

#define MSTR "magic bus"

static void
xput_tfile(const char *path, const char *mstr)
{
        int fd;

        fd = rump_sys_open(path, O_CREAT | O_RDWR, 0777);
        if (fd == -1)
                atf_tc_fail_errno("create %s", path);
        if (rump_sys_write(fd, MSTR, sizeof(MSTR)) != sizeof(MSTR))
                atf_tc_fail_errno("write to testfile");
        rump_sys_close(fd);
}

static int
xread_tfile(const char *path, const char *mstr)
{
        char buf[128];
        int fd;

        fd = rump_sys_open(path, O_RDONLY);
        if (fd == -1)
                return errno;
        if (rump_sys_read(fd, buf, sizeof(buf)) == -1)
                atf_tc_fail_errno("read tfile");
        rump_sys_close(fd);
        if (strcmp(buf, MSTR) == 0)
                return 0;
        return EPROGMISMATCH;
}

static void
mountnull(const char *what, const char *mp, int flags)
{
        struct null_args nargs;

        memset(&nargs, 0, sizeof(nargs));
        nargs.nulla_target = __UNCONST(what);
        if (rump_sys_mount(MOUNT_NULL, mp, flags, &nargs, sizeof(nargs)) == -1)
                atf_tc_fail_errno("could not mount nullfs");

}

ATF_TC_BODY(basic, tc)
{
        struct tmpfs_args targs;
        struct stat sb;
        int error;

        rump_init();
        if (rump_sys_mkdir("/td1", 0777) == -1)
                atf_tc_fail_errno("mkdir /td1");
        if (rump_sys_mkdir("/td2", 0777) == -1)
                atf_tc_fail_errno("mkdir /td2");

        /* use tmpfs because rumpfs doesn't support regular files */
        memset(&targs, 0, sizeof(targs));
        targs.ta_version = TMPFS_ARGS_VERSION;
        targs.ta_root_mode = 0777;
        if (rump_sys_mount(MOUNT_TMPFS, "/td1", 0, &targs, sizeof(targs)) == -1)
                atf_tc_fail_errno("could not mount tmpfs td1");

        mountnull("/td1", "/td2", 0);

        /* test unnull -> null */
        xput_tfile("/td1/tensti", "jeppe");
        error = xread_tfile("/td2/tensti", "jeppe");
        if (error != 0)
                atf_tc_fail("null compare failed: %d (%s)",
                    error, strerror(error));

        /* test null -> unnull */
        xput_tfile("/td2/kiekko", "keppi");
        error = xread_tfile("/td1/kiekko", "keppi");
        if (error != 0)
                atf_tc_fail("unnull compare failed: %d (%s)",
                    error, strerror(error));

        /* test unnull -> null overwrite */
        xput_tfile("/td1/tensti", "se oolannin sota");
        error = xread_tfile("/td2/tensti", "se oolannin sota");
        if (error != 0)
                atf_tc_fail("unnull compare failed: %d (%s)",
                    error, strerror(error));

        /* test that /td2 is unaffected in "real life" */
        if (rump_sys_unmount("/td2", 0) == -1)
                atf_tc_fail_errno("cannot unmount nullfs");
        if ((error = rump_sys_stat("/td2/tensti", &sb)) != -1
            || errno != ENOENT) {
                atf_tc_fail("stat tensti should return ENOENT, got %d", error);
        }
        if ((error = rump_sys_stat("/td2/kiekko", &sb)) != -1
            || errno != ENOENT) {
                atf_tc_fail("stat kiekko should return ENOENT, got %d", error);
        }

        /* done */
}

ATF_TC(twistymount);
ATF_TC_HEAD(twistymount, tc)
{

        /* this is expected to fail until the PR is fixed */
        atf_tc_set_md_var(tc, "descr", "\"recursive\" mounts deadlock"
            " (PR kern/43439)");
}

/*
 * Mapping to identifiers in PR kern/43439:
 *  /td         = /home/current/pkgsrc
 *  /td/dist    = /home/current/pkgsrc/distiles
 *  /mp         = /usr/pkgsrc
 *  /mp/dist    = /usr/pkgsrc/distfiles -- "created" by first null mount
 */

ATF_TC_BODY(twistymount, tc)
{
        rump_init();

        if (rump_sys_mkdir("/td", 0777) == -1)
                atf_tc_fail_errno("mkdir /td");
        if (rump_sys_mkdir("/td/dist", 0777) == -1)
                atf_tc_fail_errno("mkdir /td/dist");
        if (rump_sys_mkdir("/mp", 0777) == -1)
                atf_tc_fail_errno("mkdir /mp");

        /* MNT_RDONLY doesn't matter, but just for compat with the PR */
        mountnull("/td", "/mp", MNT_RDONLY);
        mountnull("/td/dist", "/mp/dist", 0);

        /* if we didn't get a locking-against-meself panic, we passed */
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, basic);
        ATF_TP_ADD_TC(tp, twistymount);

        return atf_no_error();
}