// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <string.h>

#include "log.h"
#include "timens.h"

#define OFFSET (36000)

int main(int argc, char *argv[])
{
        struct timespec now, tst;
        int status, i;
        pid_t pid;

        if (argc > 1) {
                if (sscanf(argv[1], "%ld", &now.tv_sec) != 1)
                        return pr_perror("sscanf");

                for (i = 0; i < 2; i++) {
                        _gettime(CLOCK_MONOTONIC, &tst, i);
                        if (labs(tst.tv_sec - now.tv_sec) > 5)
                                return pr_fail("%ld %ld\n", now.tv_sec, tst.tv_sec);
                }
                return 0;
        }

        ksft_print_header();

        nscheck();

        ksft_set_plan(1);

        clock_gettime(CLOCK_MONOTONIC, &now);

        if (unshare_timens())
                return 1;

        if (_settime(CLOCK_MONOTONIC, OFFSET))
                return 1;

        for (i = 0; i < 2; i++) {
                _gettime(CLOCK_MONOTONIC, &tst, i);
                if (labs(tst.tv_sec - now.tv_sec) > 5)
                        return pr_fail("%ld %ld\n",
                                        now.tv_sec, tst.tv_sec);
        }

        if (argc > 1)
                return 0;

        pid = fork();
        if (pid < 0)
                return pr_perror("fork");

        if (pid == 0) {
                char now_str[64];
                char *cargv[] = {"exec", now_str, NULL};
                char *cenv[] = {NULL};

                /* Check that a child process is in the new timens. */
                for (i = 0; i < 2; i++) {
                        _gettime(CLOCK_MONOTONIC, &tst, i);
                        if (labs(tst.tv_sec - now.tv_sec - OFFSET) > 5)
                                return pr_fail("%ld %ld\n",
                                                now.tv_sec + OFFSET, tst.tv_sec);
                }

                /* Check for proper vvar offsets after execve. */
                snprintf(now_str, sizeof(now_str), "%ld", now.tv_sec + OFFSET);
                execve("/proc/self/exe", cargv, cenv);
                return pr_perror("execve");
        }

        if (waitpid(pid, &status, 0) != pid)
                return pr_perror("waitpid");

        if (status)
                ksft_exit_fail();

        ksft_test_result_pass("exec\n");
        ksft_exit_pass();
        return 0;
}