/*      $NetBSD: subr_time.c,v 1.43 2026/01/04 03:21:11 riastradh Exp $ */

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *      @(#)kern_clock.c        8.5 (Berkeley) 1/21/94
 *      @(#)kern_time.c 8.4 (Berkeley) 5/26/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.43 2026/01/04 03:21:11 riastradh Exp $");

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

#include <sys/intr.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
#include <sys/lwp.h>
#include <sys/proc.h>
#include <sys/sdt.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/timex.h>

/*
 * Compute number of hz until specified time.  Used to compute second
 * argument to callout_reset() from an absolute time.
 */
int
tvhzto(const struct timeval *tvp)
{
        struct timeval now, tv;

        tv = *tvp;      /* Don't modify original tvp. */
        getmicrotime(&now);
        timersub(&tv, &now, &tv);
        return tvtohz(&tv);
}

int
tshzto(const struct timespec *tsp)
{
        struct timespec now, ts;

        ts = *tsp;      /* Don't modify original tsp. */
        getnanotime(&now);
        timespecsub(&ts, &now, &ts);
        return tstohz(&ts);
}

int
tshztoup(const struct timespec *tsp)
{
        struct timespec now, ts;

        ts = *tsp;      /* Don't modify original tsp. */
        getnanouptime(&now);
        timespecsub(&ts, &now, &ts);
        return tstohz(&ts);
}

int
inittimeleft(struct timespec *ts, struct timespec *sleepts)
{

        if (itimespecfix(ts)) {
                return -1;
        }
        KASSERT(ts->tv_sec >= 0);
        getnanouptime(sleepts);
        return 0;
}

int
gettimeleft(struct timespec *ts, struct timespec *sleepts)
{
        struct timespec now, sleptts;

        KASSERT(ts->tv_sec >= 0);

        /*
         * Reduce ts by elapsed time based on monotonic time scale.
         */
        getnanouptime(&now);
        KASSERT(timespeccmp(sleepts, &now, <=));
        timespecsub(&now, sleepts, &sleptts);
        *sleepts = now;

        if (timespeccmp(ts, &sleptts, <=)) { /* timed out */
                timespecclear(ts);
                return 0;
        }
        timespecsub(ts, &sleptts, ts);

        return tstohz(ts);
}

void
clock_timeleft(clockid_t clockid, struct timespec *ts, struct timespec *sleepts)
{
        struct timespec sleptts;

        clock_gettime1(clockid, &sleptts);
        timespecadd(ts, sleepts, ts);
        timespecsub(ts, &sleptts, ts);
        *sleepts = sleptts;
}

int
clock_gettime1(clockid_t clock_id, struct timespec *ts)
{
        int error;
        struct proc *p;

#define CPUCLOCK_ID_MASK (~(CLOCK_THREAD_CPUTIME_ID|CLOCK_PROCESS_CPUTIME_ID))
        if (clock_id & CLOCK_PROCESS_CPUTIME_ID) {
                pid_t pid = clock_id & CPUCLOCK_ID_MASK;
                struct timeval cputime;

                mutex_enter(&proc_lock);
                p = pid == 0 ? curproc : proc_find(pid);
                if (p == NULL) {
                        mutex_exit(&proc_lock);
                        return SET_ERROR(ESRCH);
                }
                mutex_enter(p->p_lock);
                calcru(p, /*usertime*/NULL, /*systime*/NULL, /*intrtime*/NULL,
                    &cputime);
                mutex_exit(p->p_lock);
                mutex_exit(&proc_lock);

                // XXX: Perhaps create a special kauth type
                error = kauth_authorize_process(kauth_cred_get(),
                    KAUTH_PROCESS_PTRACE, p,
                    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
                if (error)
                        return error;

                TIMEVAL_TO_TIMESPEC(&cputime, ts);
                return 0;
        } else if (clock_id & CLOCK_THREAD_CPUTIME_ID) {
                struct lwp *l;
                lwpid_t lid = clock_id & CPUCLOCK_ID_MASK;
                struct bintime tm = {0, 0};

                p = curproc;
                mutex_enter(p->p_lock);
                l = lid == 0 ? curlwp : lwp_find(p, lid);
                if (l == NULL) {
                        mutex_exit(p->p_lock);
                        return SET_ERROR(ESRCH);
                }
                addrulwp(l, &tm);
                mutex_exit(p->p_lock);

                bintime2timespec(&tm, ts);
                return 0;
        }

        switch (clock_id) {
        case CLOCK_REALTIME:
                nanotime(ts);
                break;
        case CLOCK_MONOTONIC:
                nanouptime(ts);
                break;
        default:
                return SET_ERROR(EINVAL);
        }

        return 0;
}

/*
 * Calculate delta and convert from struct timespec to the ticks.
 */
int
ts2timo(clockid_t clock_id, int flags, struct timespec *ts,
    int *timo, struct timespec *start)
{
        int error;
        struct timespec tsd;

        if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000L)
                return SET_ERROR(EINVAL);

        if ((flags & TIMER_ABSTIME) != 0 || start != NULL) {
                error = clock_gettime1(clock_id, &tsd);
                if (error != 0)
                        return error;
                if (start != NULL)
                        *start = tsd;
        }

        if ((flags & TIMER_ABSTIME) != 0) {
                if (!timespecsubok(ts, &tsd))
                        return SET_ERROR(EINVAL);
                timespecsub(ts, &tsd, &tsd);
                ts = &tsd;
        }

        error = itimespecfix(ts);
        if (error != 0)
                return error;

        if (ts->tv_sec == 0 && ts->tv_nsec == 0)
                return SET_ERROR(ETIMEDOUT);

        *timo = tstohz(ts);
        KASSERT(*timo > 0);

        return 0;
}