/*	$OpenBSD: kern_resource.c,v 1.41 2013/04/01 01:07:34 guenther Exp $	*/
/*	$NetBSD: kern_resource.c,v 1.38 1996/10/23 07:19:38 matthias Exp $	*/

/*-
 * Copyright (c) 1982, 1986, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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_resource.c	8.5 (Berkeley) 1/21/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/resourcevar.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/ktrace.h>
#include <sys/sched.h>

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

#include <uvm/uvm_extern.h>

void	tuagg_sub(struct tusage *, struct proc *);
void	tuagg(struct process *, struct proc *);

/*
 * Patchable maximum data and stack limits.
 */
rlim_t maxdmap = MAXDSIZ;
rlim_t maxsmap = MAXSSIZ;

/*
 * Resource controls and accounting.
 */

int
sys_getpriority(struct proc *curp, void *v, register_t *retval)
{
	struct sys_getpriority_args /* {
		syscallarg(int) which;
		syscallarg(id_t) who;
	} */ *uap = v;
	struct process *pr;
	struct proc *p;
	int low = NZERO + PRIO_MAX + 1;

	switch (SCARG(uap, which)) {

	case PRIO_PROCESS:
		if (SCARG(uap, who) == 0)
			pr = curp->p_p;
		else
			pr = prfind(SCARG(uap, who));
		if (pr == NULL)
			break;
		if (pr->ps_nice < low)
			low = pr->ps_nice;
		break;

	case PRIO_PGRP: {
		struct pgrp *pg;

		if (SCARG(uap, who) == 0)
			pg = curp->p_p->ps_pgrp;
		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
			break;
		LIST_FOREACH(pr, &pg->pg_members, ps_pglist)
			if (pr->ps_nice < low)
				low = pr->ps_nice;
		break;
	}

	case PRIO_USER:
		if (SCARG(uap, who) == 0)
			SCARG(uap, who) = curp->p_ucred->cr_uid;
		LIST_FOREACH(p, &allproc, p_list)
			if ((p->p_flag & P_THREAD) == 0 &&
			    p->p_ucred->cr_uid == SCARG(uap, who) &&
			    p->p_p->ps_nice < low)
				low = p->p_p->ps_nice;
		break;

	default:
		return (EINVAL);
	}
	if (low == NZERO + PRIO_MAX + 1)
		return (ESRCH);
	*retval = low - NZERO;
	return (0);
}

/* ARGSUSED */
int
sys_setpriority(struct proc *curp, void *v, register_t *retval)
{
	struct sys_setpriority_args /* {
		syscallarg(int) which;
		syscallarg(id_t) who;
		syscallarg(int) prio;
	} */ *uap = v;
	struct process *pr;
	int found = 0, error = 0;

	switch (SCARG(uap, which)) {

	case PRIO_PROCESS:
		if (SCARG(uap, who) == 0)
			pr = curp->p_p;
		else
			pr = prfind(SCARG(uap, who));
		if (pr == NULL)
			break;
		error = donice(curp, pr, SCARG(uap, prio));
		found++;
		break;

	case PRIO_PGRP: {
		struct pgrp *pg;
		 
		if (SCARG(uap, who) == 0)
			pg = curp->p_p->ps_pgrp;
		else if ((pg = pgfind(SCARG(uap, who))) == NULL)
			break;
		LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
			error = donice(curp, pr, SCARG(uap, prio));
			found++;
		}
		break;
	}

	case PRIO_USER: {
		struct proc *p;
		if (SCARG(uap, who) == 0)
			SCARG(uap, who) = curp->p_ucred->cr_uid;
		LIST_FOREACH(p, &allproc, p_list)
			if ((p->p_flag & P_THREAD) == 0 &&
			    p->p_ucred->cr_uid == SCARG(uap, who)) {
				error = donice(curp, p->p_p, SCARG(uap, prio));
				found++;
			}
		break;
	}

	default:
		return (EINVAL);
	}
	if (found == 0)
		return (ESRCH);
	return (error);
}

int
donice(struct proc *curp, struct process *chgpr, int n)
{
	struct pcred *pcred = curp->p_cred;
	struct proc *p;
	int s;

	if (pcred->pc_ucred->cr_uid && pcred->p_ruid &&
	    pcred->pc_ucred->cr_uid != chgpr->ps_cred->pc_ucred->cr_uid &&
	    pcred->p_ruid != chgpr->ps_cred->pc_ucred->cr_uid)
		return (EPERM);
	if (n > PRIO_MAX)
		n = PRIO_MAX;
	if (n < PRIO_MIN)
		n = PRIO_MIN;
	n += NZERO;
	if (n < chgpr->ps_nice && suser(curp, 0))
		return (EACCES);
	chgpr->ps_nice = n;
	SCHED_LOCK(s);
	TAILQ_FOREACH(p, &chgpr->ps_threads, p_thr_link)
		(void)resetpriority(p);
	SCHED_UNLOCK(s);
	return (0);
}

/* ARGSUSED */
int
sys_setrlimit(struct proc *p, void *v, register_t *retval)
{
	struct sys_setrlimit_args /* {
		syscallarg(int) which;
		syscallarg(const struct rlimit *) rlp;
	} */ *uap = v;
	struct rlimit alim;
	int error;

	error = copyin((caddr_t)SCARG(uap, rlp), (caddr_t)&alim,
		       sizeof (struct rlimit));
	if (error)
		return (error);
#ifdef KTRACE
	if (KTRPOINT(p, KTR_STRUCT))
		ktrrlimit(p, &alim);
#endif
	return (dosetrlimit(p, SCARG(uap, which), &alim));
}

int
dosetrlimit(struct proc *p, u_int which, struct rlimit *limp)
{
	struct rlimit *alimp;
	rlim_t maxlim;
	int error;

	if (which >= RLIM_NLIMITS || limp->rlim_cur > limp->rlim_max)
		return (EINVAL);

	alimp = &p->p_rlimit[which];
	if (limp->rlim_max > alimp->rlim_max)
		if ((error = suser(p, 0)) != 0)
			return (error);
	if (p->p_p->ps_limit->p_refcnt > 1) {
		struct plimit *l = p->p_p->ps_limit;

		/* limcopy() can sleep, so copy before decrementing refcnt */
		p->p_p->ps_limit = limcopy(l);
		limfree(l);
		alimp = &p->p_rlimit[which];
	}

	switch (which) {
	case RLIMIT_DATA:
		maxlim = maxdmap;
		break;
	case RLIMIT_STACK:
		maxlim = maxsmap;
		break;
	case RLIMIT_NOFILE:
		maxlim = maxfiles;
		break;
	case RLIMIT_NPROC:
		maxlim = maxprocess;
		break;
	default:
		maxlim = RLIM_INFINITY;
		break;
	}

	if (limp->rlim_max > maxlim)
		limp->rlim_max = maxlim;
	if (limp->rlim_cur > limp->rlim_max)
		limp->rlim_cur = limp->rlim_max;

	if (which == RLIMIT_STACK) {
		/*
		 * Stack is allocated to the max at exec time with only
		 * "rlim_cur" bytes accessible.  If stack limit is going
		 * up make more accessible, if going down make inaccessible.
		 */
		if (limp->rlim_cur != alimp->rlim_cur) {
			vaddr_t addr;
			vsize_t size;
			vm_prot_t prot;

			if (limp->rlim_cur > alimp->rlim_cur) {
				prot = VM_PROT_READ|VM_PROT_WRITE;
				size = limp->rlim_cur - alimp->rlim_cur;
#ifdef MACHINE_STACK_GROWS_UP
				addr = USRSTACK + alimp->rlim_cur;
#else
				addr = USRSTACK - limp->rlim_cur;
#endif
			} else {
				prot = VM_PROT_NONE;
				size = alimp->rlim_cur - limp->rlim_cur;
#ifdef MACHINE_STACK_GROWS_UP
				addr = USRSTACK + limp->rlim_cur;
#else
				addr = USRSTACK - alimp->rlim_cur;
#endif
			}
			addr = trunc_page(addr);
			size = round_page(size);
			(void) uvm_map_protect(&p->p_vmspace->vm_map,
					      addr, addr+size, prot, FALSE);
		}
	}

	*alimp = *limp;
	return (0);
}

/* ARGSUSED */
int
sys_getrlimit(struct proc *p, void *v, register_t *retval)
{
	struct sys_getrlimit_args /* {
		syscallarg(int) which;
		syscallarg(struct rlimit *) rlp;
	} */ *uap = v;
	struct rlimit *alimp;
	int error;

	if (SCARG(uap, which) < 0 || SCARG(uap, which) >= RLIM_NLIMITS)
		return (EINVAL);
	alimp = &p->p_rlimit[SCARG(uap, which)];
	error = copyout(alimp, SCARG(uap, rlp), sizeof(struct rlimit));
#ifdef KTRACE
	if (error == 0 && KTRPOINT(p, KTR_STRUCT))
		ktrrlimit(p, alimp);
#endif
	return (error);
}

void
tuagg_sub(struct tusage *tup, struct proc *p)
{
	timeradd(&tup->tu_runtime, &p->p_rtime, &tup->tu_runtime);
	tup->tu_uticks += p->p_uticks;
	tup->tu_sticks += p->p_sticks;
	tup->tu_iticks += p->p_iticks;
}

/*
 * Aggregate a single thread's immediate time counts into the running
 * totals for the thread and process
 */
void
tuagg_unlocked(struct process *pr, struct proc *p)
{
	tuagg_sub(&pr->ps_tu, p);
	tuagg_sub(&p->p_tu, p);
	timerclear(&p->p_rtime);
	p->p_uticks = 0;
	p->p_sticks = 0;
	p->p_iticks = 0;
}

void
tuagg(struct process *pr, struct proc *p)
{
	int s;

	SCHED_LOCK(s);
	tuagg_unlocked(pr, p);
	SCHED_UNLOCK(s);
}

/*
 * Transform the running time and tick information in a struct tusage
 * into user, system, and interrupt time usage.
 */
void
calcru(struct tusage *tup, struct timeval *up, struct timeval *sp,
    struct timeval *ip)
{
	u_quad_t st, ut, it;
	int freq;

	st = tup->tu_sticks;
	ut = tup->tu_uticks;
	it = tup->tu_iticks;

	if (st + ut + it == 0) {
		timerclear(up);
		timerclear(sp);
		if (ip != NULL)
			timerclear(ip);
		return;
	}

	freq = stathz ? stathz : hz;

	st = st * 1000000 / freq;
	sp->tv_sec = st / 1000000;
	sp->tv_usec = st % 1000000;
	ut = ut * 1000000 / freq;
	up->tv_sec = ut / 1000000;
	up->tv_usec = ut % 1000000;
	if (ip != NULL) {
		it = it * 1000000 / freq;
		ip->tv_sec = it / 1000000;
		ip->tv_usec = it % 1000000;
	}
}

/* ARGSUSED */
int
sys_getrusage(struct proc *p, void *v, register_t *retval)
{
	struct sys_getrusage_args /* {
		syscallarg(int) who;
		syscallarg(struct rusage *) rusage;
	} */ *uap = v;
	struct process *pr = p->p_p;
	struct proc *q;
	struct rusage ru;
	struct rusage *rup;

	switch (SCARG(uap, who)) {

	case RUSAGE_SELF:
		/* start with the sum of dead threads, if any */
		if (pr->ps_ru != NULL)
			ru = *pr->ps_ru;
		else
			bzero(&ru, sizeof(ru));
		rup = &ru;

		/* add on all living threads */
		TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) {
			ruadd(rup, &q->p_ru);
			tuagg(pr, q);
		}

		calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL);
		break;

	case RUSAGE_THREAD:
		rup = &p->p_ru;
		calcru(&p->p_tu, &rup->ru_utime, &rup->ru_stime, NULL);
		break;

	case RUSAGE_CHILDREN:
		rup = &pr->ps_cru;
		break;

	default:
		return (EINVAL);
	}
	return (copyout((caddr_t)rup, (caddr_t)SCARG(uap, rusage),
	    sizeof (struct rusage)));
}

void
ruadd(struct rusage *ru, struct rusage *ru2)
{
	long *ip, *ip2;
	int i;

	timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime);
	timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->ru_stime);
	if (ru->ru_maxrss < ru2->ru_maxrss)
		ru->ru_maxrss = ru2->ru_maxrss;
	ip = &ru->ru_first; ip2 = &ru2->ru_first;
	for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
		*ip++ += *ip2++;
}

struct pool plimit_pool;

/*
 * Make a copy of the plimit structure.
 * We share these structures copy-on-write after fork,
 * and copy when a limit is changed.
 */
struct plimit *
limcopy(struct plimit *lim)
{
	struct plimit *newlim;
	static int initialized;

	if (!initialized) {
		pool_init(&plimit_pool, sizeof(struct plimit), 0, 0, 0,
		    "plimitpl", &pool_allocator_nointr);
		initialized = 1;
	}

	newlim = pool_get(&plimit_pool, PR_WAITOK);
	bcopy(lim->pl_rlimit, newlim->pl_rlimit,
	    sizeof(struct rlimit) * RLIM_NLIMITS);
	newlim->p_refcnt = 1;
	return (newlim);
}

void
limfree(struct plimit *lim)
{
	if (--lim->p_refcnt > 0)
		return;
	pool_put(&plimit_pool, lim);
}