/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __TIMENS_H__
#define __TIMENS_H__

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>

#include "kselftest.h"

#ifndef CLONE_NEWTIME
# define CLONE_NEWTIME  0x00000080
#endif

static int config_posix_timers = true;
static int config_alarm_timers = true;

static inline void check_supported_timers(void)
{
        struct timespec ts;

        if (timer_create(-1, 0, 0) == -1 && errno == ENOSYS)
                config_posix_timers = false;

        if (clock_gettime(CLOCK_BOOTTIME_ALARM, &ts) == -1 && errno == EINVAL)
                config_alarm_timers = false;
}

static inline bool check_skip(int clockid)
{
        if (!config_alarm_timers && clockid == CLOCK_BOOTTIME_ALARM) {
                ksft_test_result_skip("CLOCK_BOOTTIME_ALARM isn't supported\n");
                return true;
        }

        if (config_posix_timers)
                return false;

        switch (clockid) {
        /* Only these clocks are supported without CONFIG_POSIX_TIMERS. */
        case CLOCK_BOOTTIME:
        case CLOCK_MONOTONIC:
        case CLOCK_REALTIME:
                return false;
        default:
                ksft_test_result_skip("Posix Clocks & timers are not supported\n");
                return true;
        }

        return false;
}

static inline int unshare_timens(void)
{
        if (unshare(CLONE_NEWTIME)) {
                if (errno == EPERM)
                        ksft_exit_skip("need to run as root\n");
                return pr_perror("Can't unshare() timens");
        }
        return 0;
}

static inline int _settime(clockid_t clk_id, time_t offset)
{
        int fd, len;
        char buf[4096];

        if (clk_id == CLOCK_MONOTONIC_COARSE || clk_id == CLOCK_MONOTONIC_RAW)
                clk_id = CLOCK_MONOTONIC;

        len = snprintf(buf, sizeof(buf), "%d %ld 0", clk_id, offset);

        fd = open("/proc/self/timens_offsets", O_WRONLY);
        if (fd < 0)
                return pr_perror("/proc/self/timens_offsets");

        if (write(fd, buf, len) != len)
                return pr_perror("/proc/self/timens_offsets");

        close(fd);

        return 0;
}

static inline int _gettime(clockid_t clk_id, struct timespec *res, bool raw_syscall)
{
        int err;

        if (!raw_syscall) {
                if (clock_gettime(clk_id, res)) {
                        pr_perror("clock_gettime(%d)", (int)clk_id);
                        return -1;
                }
                return 0;
        }

        err = syscall(SYS_clock_gettime, clk_id, res);
        if (err)
                pr_perror("syscall(SYS_clock_gettime(%d))", (int)clk_id);

        return err;
}

static inline void nscheck(void)
{
        if (access("/proc/self/ns/time", F_OK) < 0)
                ksft_exit_skip("Time namespaces are not supported\n");
}

#endif