/* $NetBSD: kern_resource.c,v 1.195 2023/10/04 20:28:06 ad Exp $ */

/* $NetBSD: kern_resource.c,v 1.195 2023/10/04 20:28:06 ad 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 8.8 (Berkeley) 2/14/95
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_resource.c,v 1.195 2023/10/04 20:28:06 ad Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/resourcevar.h>
#include <sys/kmem.h>
#include <sys/namei.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/timevar.h>
#include <sys/kauth.h>
#include <sys/atomic.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/atomic.h>

#include <uvm/uvm_extern.h>

/*
* Maximum process data and stack limits.
* They are variables so they are patchable.
*/
rlim_t maxdmap = MAXDSIZ;
rlim_t maxsmap = MAXSSIZ;

static kauth_listener_t resource_listener;
static struct sysctllog *proc_sysctllog;

static int donice(struct lwp *, struct proc *, int);
static void sysctl_proc_setup(void);

static int
resource_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
void *arg0, void *arg1, void *arg2, void *arg3)
{
struct proc *p;
int result;

result = KAUTH_RESULT_DEFER;
p = arg0;

switch (action) {
case KAUTH_PROCESS_NICE:
if (kauth_cred_geteuid(cred) != kauth_cred_geteuid(p->p_cred) &&
kauth_cred_getuid(cred) != kauth_cred_geteuid(p->p_cred)) {
break;
}

if ((u_long)arg1 >= p->p_nice)
result = KAUTH_RESULT_ALLOW;

break;

case KAUTH_PROCESS_RLIMIT: {
enum kauth_process_req req;

req = (enum kauth_process_req)(uintptr_t)arg1;

switch (req) {
case KAUTH_REQ_PROCESS_RLIMIT_GET:
result = KAUTH_RESULT_ALLOW;
break;

case KAUTH_REQ_PROCESS_RLIMIT_SET: {
struct rlimit *new_rlimit;
u_long which;

if ((p != curlwp->l_proc) &&
(proc_uidmatch(cred, p->p_cred) != 0))
break;

new_rlimit = arg2;
which = (u_long)arg3;

if (new_rlimit->rlim_max <= p->p_rlimit[which].rlim_max)
result = KAUTH_RESULT_ALLOW;

break;
}

default:
break;
}

break;
}

default:
break;
}

return result;
}

void
resource_init(void)
{

resource_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
resource_listener_cb, NULL);

sysctl_proc_setup();
}

/*
* Resource controls and accounting.
*/

int
sys_getpriority(struct lwp *l, const struct sys_getpriority_args *uap,
register_t *retval)
{
/* {
syscallarg(int) which;
syscallarg(id_t) who;
} */
struct proc *curp = l->l_proc, *p;
id_t who = SCARG(uap, who);
int low = NZERO + PRIO_MAX + 1;

mutex_enter(&proc_lock);
switch (SCARG(uap, which)) {
case PRIO_PROCESS:
p = who ? proc_find(who) : curp;
if (p != NULL)
low = p->p_nice;
break;

case PRIO_PGRP: {
struct pgrp *pg;

if (who == 0)
pg = curp->p_pgrp;
else if ((pg = pgrp_find(who)) == NULL)
break;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (p->p_nice < low)
low = p->p_nice;
}
break;
}

case PRIO_USER:
if (who == 0)
who = (int)kauth_cred_geteuid(l->l_cred);
PROCLIST_FOREACH(p, &allproc) {
mutex_enter(p->p_lock);
if (kauth_cred_geteuid(p->p_cred) ==
(uid_t)who && p->p_nice < low)
low = p->p_nice;
mutex_exit(p->p_lock);
}
break;

default:
mutex_exit(&proc_lock);
return EINVAL;
}
mutex_exit(&proc_lock);

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

int
sys_setpriority(struct lwp *l, const struct sys_setpriority_args *uap,
register_t *retval)
{
/* {
syscallarg(int) which;
syscallarg(id_t) who;
syscallarg(int) prio;
} */
struct proc *curp = l->l_proc, *p;
id_t who = SCARG(uap, who);
int found = 0, error = 0;

mutex_enter(&proc_lock);
switch (SCARG(uap, which)) {
case PRIO_PROCESS:
p = who ? proc_find(who) : curp;
if (p != NULL) {
mutex_enter(p->p_lock);
found++;
error = donice(l, p, SCARG(uap, prio));
mutex_exit(p->p_lock);
}
break;

case PRIO_PGRP: {
struct pgrp *pg;

if (who == 0)
pg = curp->p_pgrp;
else if ((pg = pgrp_find(who)) == NULL)
break;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
mutex_enter(p->p_lock);
found++;
error = donice(l, p, SCARG(uap, prio));
mutex_exit(p->p_lock);
if (error)
break;
}
break;
}

case PRIO_USER:
if (who == 0)
who = (int)kauth_cred_geteuid(l->l_cred);
PROCLIST_FOREACH(p, &allproc) {
mutex_enter(p->p_lock);
if (kauth_cred_geteuid(p->p_cred) ==
(uid_t)SCARG(uap, who)) {
found++;
error = donice(l, p, SCARG(uap, prio));
}
mutex_exit(p->p_lock);
if (error)
break;
}
break;

default:
mutex_exit(&proc_lock);
return EINVAL;
}
mutex_exit(&proc_lock);

return (found == 0) ? ESRCH : error;
}

/*
* Renice a process.
*
* Call with the target process' credentials locked.
*/
static int
donice(struct lwp *l, struct proc *chgp, int n)
{
kauth_cred_t cred = l->l_cred;

KASSERT(mutex_owned(chgp->p_lock));

if (kauth_cred_geteuid(cred) && kauth_cred_getuid(cred) &&
kauth_cred_geteuid(cred) != kauth_cred_geteuid(chgp->p_cred) &&
kauth_cred_getuid(cred) != kauth_cred_geteuid(chgp->p_cred))
return EPERM;

if (n > PRIO_MAX) {
n = PRIO_MAX;
}
if (n < PRIO_MIN) {
n = PRIO_MIN;
}
n += NZERO;

if (kauth_authorize_process(cred, KAUTH_PROCESS_NICE, chgp,
KAUTH_ARG(n), NULL, NULL)) {
return EACCES;
}

sched_nice(chgp, n);
return 0;
}

int
sys_setrlimit(struct lwp *l, const struct sys_setrlimit_args *uap,
register_t *retval)
{
/* {
syscallarg(int) which;
syscallarg(const struct rlimit *) rlp;
} */
int error, which = SCARG(uap, which);
struct rlimit alim;

error = copyin(SCARG(uap, rlp), &alim, sizeof(struct rlimit));
if (error) {
return error;
}
return dosetrlimit(l, l->l_proc, which, &alim);
}

int
dosetrlimit(struct lwp *l, struct proc *p, int which, struct rlimit *limp)
{
struct rlimit *alimp;
int error;

if ((u_int)which >= RLIM_NLIMITS)
return EINVAL;

if (limp->rlim_cur > limp->rlim_max) {
/*
* This is programming error. According to SUSv2, we should
* return error in this case.
*/
return EINVAL;
}

alimp = &p->p_rlimit[which];
/* if we don't change the value, no need to limcopy() */
if (limp->rlim_cur == alimp->rlim_cur &&
limp->rlim_max == alimp->rlim_max)
return 0;

error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_SET), limp, KAUTH_ARG(which));
if (error)
return error;

lim_privatise(p);
/* p->p_limit is now unchangeable */
alimp = &p->p_rlimit[which];

switch (which) {

case RLIMIT_DATA:
if (limp->rlim_cur > maxdmap)
limp->rlim_cur = maxdmap;
if (limp->rlim_max > maxdmap)
limp->rlim_max = maxdmap;
break;

case RLIMIT_STACK:
if (limp->rlim_cur > maxsmap)
limp->rlim_cur = maxsmap;
if (limp->rlim_max > maxsmap)
limp->rlim_max = maxsmap;

/*
* Return EINVAL if the new stack size limit is lower than
* current usage. Otherwise, the process would get SIGSEGV the
* moment it would try to access anything on its current stack.
* This conforms to SUSv2.
*/
if (btoc(limp->rlim_cur) < p->p_vmspace->vm_ssize ||
btoc(limp->rlim_max) < p->p_vmspace->vm_ssize) {
return EINVAL;
}

/*
* Stack is allocated to the max at exec time with
* only "rlim_cur" bytes accessible (In other words,
* allocates stack dividing two contiguous regions at
* "rlim_cur" bytes boundary).
*
* Since allocation is done in terms of page, roundup
* "rlim_cur" (otherwise, contiguous regions
* overlap). If stack limit is going up make more
* accessible, if going down make inaccessible.
*/
limp->rlim_max = round_page(limp->rlim_max);
limp->rlim_cur = round_page(limp->rlim_cur);
if (limp->rlim_cur != alimp->rlim_cur) {
vaddr_t addr;
vsize_t size;
vm_prot_t prot;
char *base, *tmp;

base = p->p_vmspace->vm_minsaddr;
if (limp->rlim_cur > alimp->rlim_cur) {
prot = VM_PROT_READ | VM_PROT_WRITE;
size = limp->rlim_cur - alimp->rlim_cur;
tmp = STACK_GROW(base, alimp->rlim_cur);
} else {
prot = VM_PROT_NONE;
size = alimp->rlim_cur - limp->rlim_cur;
tmp = STACK_GROW(base, limp->rlim_cur);
}
addr = (vaddr_t)STACK_ALLOC(tmp, size);
(void) uvm_map_protect(&p->p_vmspace->vm_map,
addr, addr + size, prot, false);
}
break;

case RLIMIT_NOFILE:
if (limp->rlim_cur > maxfiles)
limp->rlim_cur = maxfiles;
if (limp->rlim_max > maxfiles)
limp->rlim_max = maxfiles;
break;

case RLIMIT_NPROC:
if (limp->rlim_cur > maxproc)
limp->rlim_cur = maxproc;
if (limp->rlim_max > maxproc)
limp->rlim_max = maxproc;
break;

case RLIMIT_NTHR:
if (limp->rlim_cur > maxlwp)
limp->rlim_cur = maxlwp;
if (limp->rlim_max > maxlwp)
limp->rlim_max = maxlwp;
break;
}

mutex_enter(&p->p_limit->pl_lock);
*alimp = *limp;
mutex_exit(&p->p_limit->pl_lock);
return 0;
}

int
sys_getrlimit(struct lwp *l, const struct sys_getrlimit_args *uap,
register_t *retval)
{
/* {
syscallarg(int) which;
syscallarg(struct rlimit *) rlp;
} */
struct proc *p = l->l_proc;
int which = SCARG(uap, which);
struct rlimit rl;

if ((u_int)which >= RLIM_NLIMITS)
return EINVAL;

mutex_enter(p->p_lock);
memcpy(&rl, &p->p_rlimit[which], sizeof(rl));
mutex_exit(p->p_lock);

return copyout(&rl, SCARG(uap, rlp), sizeof(rl));
}

void
addrulwp(struct lwp *l, struct bintime *tm)
{

lwp_lock(l);
bintime_add(tm, &l->l_rtime);
if ((l->l_pflag & LP_RUNNING) != 0 &&
(l->l_pflag & (LP_INTR | LP_TIMEINTR)) != LP_INTR) {
struct bintime diff;
/*
* Adjust for the current time slice. This is
* actually fairly important since the error
* here is on the order of a time quantum,
* which is much greater than the sampling
* error.
*/
binuptime(&diff);
membar_consumer(); /* for softint_dispatch() */
bintime_sub(&diff, &l->l_stime);
bintime_add(tm, &diff);
}
lwp_unlock(l);
}

/*
* Transform the running time and tick information in proc p into user,
* system, and interrupt time usage.
*
* Should be called with p->p_lock held unless called from exit1().
*/
void
calcru(struct proc *p, struct timeval *up, struct timeval *sp,
struct timeval *ip, struct timeval *rp)
{
uint64_t u, st, ut, it, tot, dt;
struct lwp *l;
struct bintime tm;
struct timeval tv;

KASSERT(p->p_stat == SDEAD || mutex_owned(p->p_lock));

mutex_spin_enter(&p->p_stmutex);
st = p->p_sticks;
ut = p->p_uticks;
it = p->p_iticks;
mutex_spin_exit(&p->p_stmutex);

tm = p->p_rtime;

LIST_FOREACH(l, &p->p_lwps, l_sibling) {
addrulwp(l, &tm);
}

tot = st + ut + it;
bintime2timeval(&tm, &tv);
u = (uint64_t)tv.tv_sec * 1000000ul + tv.tv_usec;

if (tot == 0) {
/* No ticks, so can't use to share time out, split 50-50 */
st = ut = u / 2;
} else {
st = (u * st) / tot;
ut = (u * ut) / tot;
}

/*
* Try to avoid lying to the users (too much)
*
* Of course, user/sys time are based on sampling (ie: statistics)
* so that would be impossible, but convincing the mark
* that we have used less ?time this call than we had
* last time, is beyond reasonable... (the con fails!)
*
* Note that since actual used time cannot decrease, either
* utime or stime (or both) must be greater now than last time
* (or both the same) - if one seems to have decreased, hold
* it constant and steal the necessary bump from the other
* which must have increased.
*/
if (p->p_xutime > ut) {
dt = p->p_xutime - ut;
st -= uimin(dt, st);
ut = p->p_xutime;
} else if (p->p_xstime > st) {
dt = p->p_xstime - st;
ut -= uimin(dt, ut);
st = p->p_xstime;
}

if (sp != NULL) {
p->p_xstime = st;
sp->tv_sec = st / 1000000;
sp->tv_usec = st % 1000000;
}
if (up != NULL) {
p->p_xutime = ut;
up->tv_sec = ut / 1000000;
up->tv_usec = ut % 1000000;
}
if (ip != NULL) {
if (it != 0) /* it != 0 --> tot != 0 */
it = (u * it) / tot;
ip->tv_sec = it / 1000000;
ip->tv_usec = it % 1000000;
}
if (rp != NULL) {
*rp = tv;
}
}

int
sys___getrusage50(struct lwp *l, const struct sys___getrusage50_args *uap,
register_t *retval)
{
/* {
syscallarg(int) who;
syscallarg(struct rusage *) rusage;
} */
int error;
struct rusage ru;
struct proc *p = l->l_proc;

error = getrusage1(p, SCARG(uap, who), &ru);
if (error != 0)
return error;

return copyout(&ru, SCARG(uap, rusage), sizeof(ru));
}

int
getrusage1(struct proc *p, int who, struct rusage *ru)
{

switch (who) {
case RUSAGE_SELF:
mutex_enter(p->p_lock);
ruspace(p);
memcpy(ru, &p->p_stats->p_ru, sizeof(*ru));
calcru(p, &ru->ru_utime, &ru->ru_stime, NULL, NULL);
rulwps(p, ru);
mutex_exit(p->p_lock);
break;
case RUSAGE_CHILDREN:
mutex_enter(p->p_lock);
memcpy(ru, &p->p_stats->p_cru, sizeof(*ru));
mutex_exit(p->p_lock);
break;
default:
return EINVAL;
}

return 0;
}

void
ruspace(struct proc *p)
{
struct vmspace *vm = p->p_vmspace;
struct rusage *ru = &p->p_stats->p_ru;

ru->ru_ixrss = vm->vm_tsize << (PAGE_SHIFT - 10);
ru->ru_idrss = vm->vm_dsize << (PAGE_SHIFT - 10);
ru->ru_isrss = vm->vm_ssize << (PAGE_SHIFT - 10);
#ifdef __HAVE_NO_PMAP_STATS
/* We don't keep track of the max so we get the current */
ru->ru_maxrss = vm_resident_count(vm) << (PAGE_SHIFT - 10);
#else
ru->ru_maxrss = vm->vm_rssmax << (PAGE_SHIFT - 10);
#endif
}

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++;
}

void
rulwps(proc_t *p, struct rusage *ru)
{
lwp_t *l;

KASSERT(mutex_owned(p->p_lock));

LIST_FOREACH(l, &p->p_lwps, l_sibling) {
ruadd(ru, &l->l_ru);
}
}

/*
* lim_copy: make a copy of the plimit structure.
*
* We use copy-on-write after fork, and copy when a limit is changed.
*/
struct plimit *
lim_copy(struct plimit *lim)
{
struct plimit *newlim;
char *corename;
size_t alen, len;

newlim = kmem_alloc(sizeof(*newlim), KM_SLEEP);
mutex_init(&newlim->pl_lock, MUTEX_DEFAULT, IPL_NONE);
newlim->pl_writeable = false;
newlim->pl_refcnt = 1;
newlim->pl_sv_limit = NULL;

mutex_enter(&lim->pl_lock);
memcpy(newlim->pl_rlimit, lim->pl_rlimit,
sizeof(struct rlimit) * RLIM_NLIMITS);

/*
* Note: the common case is a use of default core name.
*/
alen = 0;
corename = NULL;
for (;;) {
if (lim->pl_corename == defcorename) {
newlim->pl_corename = defcorename;
newlim->pl_cnlen = 0;
break;
}
len = lim->pl_cnlen;
if (len == alen) {
newlim->pl_corename = corename;
newlim->pl_cnlen = len;
memcpy(corename, lim->pl_corename, len);
corename = NULL;
break;
}
mutex_exit(&lim->pl_lock);
if (corename) {
kmem_free(corename, alen);
}
alen = len;
corename = kmem_alloc(alen, KM_SLEEP);
mutex_enter(&lim->pl_lock);
}
mutex_exit(&lim->pl_lock);

if (corename) {
kmem_free(corename, alen);
}
return newlim;
}

void
lim_addref(struct plimit *lim)
{
atomic_inc_uint(&lim->pl_refcnt);
}

/*
* lim_privatise: give a process its own private plimit structure.
*/
void
lim_privatise(proc_t *p)
{
struct plimit *lim = p->p_limit, *newlim;

if (lim->pl_writeable) {
return;
}

newlim = lim_copy(lim);

mutex_enter(p->p_lock);
if (p->p_limit->pl_writeable) {
/* Other thread won the race. */
mutex_exit(p->p_lock);
lim_free(newlim);
return;
}

/*
* Since p->p_limit can be accessed without locked held,
* old limit structure must not be deleted yet.
*/
newlim->pl_sv_limit = p->p_limit;
newlim->pl_writeable = true;
p->p_limit = newlim;
mutex_exit(p->p_lock);
}

void
lim_setcorename(proc_t *p, char *name, size_t len)
{
struct plimit *lim;
char *oname;
size_t olen;

lim_privatise(p);
lim = p->p_limit;

mutex_enter(&lim->pl_lock);
oname = lim->pl_corename;
olen = lim->pl_cnlen;
lim->pl_corename = name;
lim->pl_cnlen = len;
mutex_exit(&lim->pl_lock);

if (oname != defcorename) {
kmem_free(oname, olen);
}
}

void
lim_free(struct plimit *lim)
{
struct plimit *sv_lim;

do {
membar_release();
if (atomic_dec_uint_nv(&lim->pl_refcnt) > 0) {
return;
}
membar_acquire();
if (lim->pl_corename != defcorename) {
kmem_free(lim->pl_corename, lim->pl_cnlen);
}
sv_lim = lim->pl_sv_limit;
mutex_destroy(&lim->pl_lock);
kmem_free(lim, sizeof(*lim));
} while ((lim = sv_lim) != NULL);
}

struct pstats *
pstatscopy(struct pstats *ps)
{
struct pstats *nps;
size_t len;

nps = kmem_alloc(sizeof(*nps), KM_SLEEP);

len = (char *)&nps->pstat_endzero - (char *)&nps->pstat_startzero;
memset(&nps->pstat_startzero, 0, len);

len = (char *)&nps->pstat_endcopy - (char *)&nps->pstat_startcopy;
memcpy(&nps->pstat_startcopy, &ps->pstat_startcopy, len);

return nps;
}

void
pstatsfree(struct pstats *ps)
{

kmem_free(ps, sizeof(*ps));
}

/*
* sysctl_proc_findproc: a routine for sysctl proc subtree helpers that
* need to pick a valid process by PID.
*
* => Hold a reference on the process, on success.
*/
static int
sysctl_proc_findproc(lwp_t *l, pid_t pid, proc_t **p2)
{
proc_t *p;
int error;

if (pid == PROC_CURPROC) {
p = l->l_proc;
} else {
mutex_enter(&proc_lock);
p = proc_find(pid);
if (p == NULL) {
mutex_exit(&proc_lock);
return ESRCH;
}
}
error = rw_tryenter(&p->p_reflock, RW_READER) ? 0 : EBUSY;
if (pid != PROC_CURPROC) {
mutex_exit(&proc_lock);
}
*p2 = p;
return error;
}

/*
* sysctl_proc_paxflags: helper routine to get process's paxctl flags
*/
static int
sysctl_proc_paxflags(SYSCTLFN_ARGS)
{
struct proc *p;
struct sysctlnode node;
int paxflags;
int error;

/* First, validate the request. */
if (namelen != 0 || name[-1] != PROC_PID_PAXFLAGS)
return EINVAL;

/* Find the process. Hold a reference (p_reflock), if found. */
error = sysctl_proc_findproc(l, (pid_t)name[-2], &p);
if (error)
return error;

/* XXX-elad */
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error) {
rw_exit(&p->p_reflock);
return error;
}

/* Retrieve the limits. */
node = *rnode;
paxflags = p->p_pax;
node.sysctl_data = &paxflags;

error = sysctl_lookup(SYSCTLFN_CALL(&node));

/* If attempting to write new value, it's an error */
if (error == 0 && newp != NULL)
error = EACCES;

rw_exit(&p->p_reflock);
return error;
}

/*
* sysctl_proc_corename: helper routine to get or set the core file name
* for a process specified by PID.
*/
static int
sysctl_proc_corename(SYSCTLFN_ARGS)
{
struct proc *p;
struct plimit *lim;
char *cnbuf, *cname;
struct sysctlnode node;
size_t len;
int error;

/* First, validate the request. */
if (namelen != 0 || name[-1] != PROC_PID_CORENAME)
return EINVAL;

/* Find the process. Hold a reference (p_reflock), if found. */
error = sysctl_proc_findproc(l, (pid_t)name[-2], &p);
if (error)
return error;

/* XXX-elad */
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error) {
rw_exit(&p->p_reflock);
return error;
}

cnbuf = PNBUF_GET();

if (oldp) {
/* Get case: copy the core name into the buffer. */
error = kauth_authorize_process(l->l_cred,
KAUTH_PROCESS_CORENAME, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_GET), NULL, NULL);
if (error) {
goto done;
}
lim = p->p_limit;
mutex_enter(&lim->pl_lock);
strlcpy(cnbuf, lim->pl_corename, MAXPATHLEN);
mutex_exit(&lim->pl_lock);
}

node = *rnode;
node.sysctl_data = cnbuf;
error = sysctl_lookup(SYSCTLFN_CALL(&node));

/* Return if error, or if caller is only getting the core name. */
if (error || newp == NULL) {
goto done;
}

/*
* Set case. Check permission and then validate new core name.
* It must be either "core", "/core", or end in ".core".
*/
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CORENAME,
p, KAUTH_ARG(KAUTH_REQ_PROCESS_CORENAME_SET), cnbuf, NULL);
if (error) {
goto done;
}
len = strlen(cnbuf);
if ((len < 4 || strcmp(cnbuf + len - 4, "core") != 0) ||
(len > 4 && cnbuf[len - 5] != '/' && cnbuf[len - 5] != '.')) {
error = EINVAL;
goto done;
}

/* Allocate, copy and set the new core name for plimit structure. */
cname = kmem_alloc(++len, KM_NOSLEEP);
if (cname == NULL) {
error = ENOMEM;
goto done;
}
memcpy(cname, cnbuf, len);
lim_setcorename(p, cname, len);
done:
rw_exit(&p->p_reflock);
PNBUF_PUT(cnbuf);
return error;
}

/*
* sysctl_proc_stop: helper routine for checking/setting the stop flags.
*/
static int
sysctl_proc_stop(SYSCTLFN_ARGS)
{
struct proc *p;
int isset, flag, error = 0;
struct sysctlnode node;

if (namelen != 0)
return EINVAL;

/* Find the process. Hold a reference (p_reflock), if found. */
error = sysctl_proc_findproc(l, (pid_t)name[-2], &p);
if (error)
return error;

/* XXX-elad */
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error) {
goto out;
}

/* Determine the flag. */
switch (rnode->sysctl_num) {
case PROC_PID_STOPFORK:
flag = PS_STOPFORK;
break;
case PROC_PID_STOPEXEC:
flag = PS_STOPEXEC;
break;
case PROC_PID_STOPEXIT:
flag = PS_STOPEXIT;
break;
default:
error = EINVAL;
goto out;
}
isset = (p->p_flag & flag) ? 1 : 0;
node = *rnode;
node.sysctl_data = &isset;
error = sysctl_lookup(SYSCTLFN_CALL(&node));

/* Return if error, or if callers is only getting the flag. */
if (error || newp == NULL) {
goto out;
}

/* Check if caller can set the flags. */
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_STOPFLAG,
p, KAUTH_ARG(flag), NULL, NULL);
if (error) {
goto out;
}
mutex_enter(p->p_lock);
if (isset) {
p->p_sflag |= flag;
} else {
p->p_sflag &= ~flag;
}
mutex_exit(p->p_lock);
out:
rw_exit(&p->p_reflock);
return error;
}

/*
* sysctl_proc_plimit: helper routine to get/set rlimits of a process.
*/
static int
sysctl_proc_plimit(SYSCTLFN_ARGS)
{
struct proc *p;
u_int limitno;
int which, error = 0;
struct rlimit alim;
struct sysctlnode node;

if (namelen != 0)
return EINVAL;

which = name[-1];
if (which != PROC_PID_LIMIT_TYPE_SOFT &&
which != PROC_PID_LIMIT_TYPE_HARD)
return EINVAL;

limitno = name[-2] - 1;
if (limitno >= RLIM_NLIMITS)
return EINVAL;

if (name[-3] != PROC_PID_LIMIT)
return EINVAL;

/* Find the process. Hold a reference (p_reflock), if found. */
error = sysctl_proc_findproc(l, (pid_t)name[-4], &p);
if (error)
return error;

/* XXX-elad */
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE, p,
KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
if (error)
goto out;

/* Check if caller can retrieve the limits. */
if (newp == NULL) {
error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_GET), &alim,
KAUTH_ARG(which));
if (error)
goto out;
}

/* Retrieve the limits. */
node = *rnode;
memcpy(&alim, &p->p_rlimit[limitno], sizeof(alim));
if (which == PROC_PID_LIMIT_TYPE_HARD) {
node.sysctl_data = &alim.rlim_max;
} else {
node.sysctl_data = &alim.rlim_cur;
}
error = sysctl_lookup(SYSCTLFN_CALL(&node));

/* Return if error, or if we are only retrieving the limits. */
if (error || newp == NULL) {
goto out;
}
error = dosetrlimit(l, p, limitno, &alim);
out:
rw_exit(&p->p_reflock);
return error;
}

/*
* Setup sysctl nodes.
*/
static void
sysctl_proc_setup(void)
{

sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_ANYNUMBER,
CTLTYPE_NODE, "curproc",
SYSCTL_DESCR("Per-process settings"),
NULL, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, CTL_EOL);

sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READONLY,
CTLTYPE_INT, "paxflags",
SYSCTL_DESCR("Process PAX control flags"),
sysctl_proc_paxflags, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, PROC_PID_PAXFLAGS, CTL_EOL);

sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
CTLTYPE_STRING, "corename",
SYSCTL_DESCR("Core file name"),
sysctl_proc_corename, 0, NULL, MAXPATHLEN,
CTL_PROC, PROC_CURPROC, PROC_PID_CORENAME, CTL_EOL);
sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "rlimit",
SYSCTL_DESCR("Process limits"),
NULL, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, CTL_EOL);

#define create_proc_plimit(s, n) do { \
sysctl_createv(&proc_sysctllog, 0, NULL, NULL, \
CTLFLAG_PERMANENT, \
CTLTYPE_NODE, s, \
SYSCTL_DESCR("Process " s " limits"), \
NULL, 0, NULL, 0, \
CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n, \
CTL_EOL); \
sysctl_createv(&proc_sysctllog, 0, NULL, NULL, \
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
CTLTYPE_QUAD, "soft", \
SYSCTL_DESCR("Process soft " s " limit"), \
sysctl_proc_plimit, 0, NULL, 0, \
CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n, \
PROC_PID_LIMIT_TYPE_SOFT, CTL_EOL); \
sysctl_createv(&proc_sysctllog, 0, NULL, NULL, \
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE, \
CTLTYPE_QUAD, "hard", \
SYSCTL_DESCR("Process hard " s " limit"), \
sysctl_proc_plimit, 0, NULL, 0, \
CTL_PROC, PROC_CURPROC, PROC_PID_LIMIT, n, \
PROC_PID_LIMIT_TYPE_HARD, CTL_EOL); \
} while (0/*CONSTCOND*/)

create_proc_plimit("cputime", PROC_PID_LIMIT_CPU);
create_proc_plimit("filesize", PROC_PID_LIMIT_FSIZE);
create_proc_plimit("datasize", PROC_PID_LIMIT_DATA);
create_proc_plimit("stacksize", PROC_PID_LIMIT_STACK);
create_proc_plimit("coredumpsize", PROC_PID_LIMIT_CORE);
create_proc_plimit("memoryuse", PROC_PID_LIMIT_RSS);
create_proc_plimit("memorylocked", PROC_PID_LIMIT_MEMLOCK);
create_proc_plimit("maxproc", PROC_PID_LIMIT_NPROC);
create_proc_plimit("descriptors", PROC_PID_LIMIT_NOFILE);
create_proc_plimit("sbsize", PROC_PID_LIMIT_SBSIZE);
create_proc_plimit("vmemoryuse", PROC_PID_LIMIT_AS);
create_proc_plimit("maxlwp", PROC_PID_LIMIT_NTHR);

#undef create_proc_plimit

sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
CTLTYPE_INT, "stopfork",
SYSCTL_DESCR("Stop process at fork(2)"),
sysctl_proc_stop, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, PROC_PID_STOPFORK, CTL_EOL);
sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
CTLTYPE_INT, "stopexec",
SYSCTL_DESCR("Stop process at execve(2)"),
sysctl_proc_stop, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXEC, CTL_EOL);
sysctl_createv(&proc_sysctllog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE|CTLFLAG_ANYWRITE,
CTLTYPE_INT, "stopexit",
SYSCTL_DESCR("Stop process before completing exit"),
sysctl_proc_stop, 0, NULL, 0,
CTL_PROC, PROC_CURPROC, PROC_PID_STOPEXIT, CTL_EOL);
}