/*-
* Copyright (c) 2014 John Baldwin
* Copyright (c) 2014 The FreeBSD Foundation
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capsicum.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/procctl.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/wait.h>
static int
protect_setchild(struct thread *td, struct proc *p, int flags)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p->p_flag & P_SYSTEM || p_cansched(td, p) != 0)
return (0);
if (flags & PPROT_SET) {
p->p_flag |= P_PROTECTED;
if (flags & PPROT_INHERIT)
p->p_flag2 |= P2_INHERIT_PROTECTED;
} else {
p->p_flag &= ~P_PROTECTED;
p->p_flag2 &= ~P2_INHERIT_PROTECTED;
}
return (1);
}
static int
protect_setchildren(struct thread *td, struct proc *top, int flags)
{
struct proc *p;
int ret;
p = top;
ret = 0;
sx_assert(&proctree_lock, SX_LOCKED);
for (;;) {
ret |= protect_setchild(td, p, flags);
PROC_UNLOCK(p);
/*
* If this process has children, descend to them next,
* otherwise do any siblings, and if done with this level,
* follow back up the tree (but not past top).
*/
if (!LIST_EMPTY(&p->p_children))
p = LIST_FIRST(&p->p_children);
else for (;;) {
if (p == top) {
PROC_LOCK(p);
return (ret);
}
if (LIST_NEXT(p, p_sibling)) {
p = LIST_NEXT(p, p_sibling);
break;
}
p = p->p_pptr;
}
PROC_LOCK(p);
}
}
static int
protect_set(struct thread *td, struct proc *p, int flags)
{
int error, ret;
switch (PPROT_OP(flags)) {
case PPROT_SET:
case PPROT_CLEAR:
break;
default:
return (EINVAL);
}
if ((PPROT_FLAGS(flags) & ~(PPROT_DESCEND | PPROT_INHERIT)) != 0)
return (EINVAL);
error = priv_check(td, PRIV_VM_MADV_PROTECT);
if (error)
return (error);
if (flags & PPROT_DESCEND)
ret = protect_setchildren(td, p, flags);
else
ret = protect_setchild(td, p, flags);
if (ret == 0)
return (EPERM);
return (0);
}
static int
reap_acquire(struct thread *td, struct proc *p)
{
sx_assert(&proctree_lock, SX_XLOCKED);
if (p != curproc)
return (EPERM);
if ((p->p_treeflag & P_TREE_REAPER) != 0)
return (EBUSY);
p->p_treeflag |= P_TREE_REAPER;
/*
* We do not reattach existing children and the whole tree
* under them to us, since p->p_reaper already seen them.
*/
return (0);
}
static int
reap_release(struct thread *td, struct proc *p)
{
sx_assert(&proctree_lock, SX_XLOCKED);
if (p != curproc)
return (EPERM);
if (p == initproc)
return (EINVAL);
if ((p->p_treeflag & P_TREE_REAPER) == 0)
return (EINVAL);
reaper_abandon_children(p, false);
return (0);
}
static int
reap_status(struct thread *td, struct proc *p,
struct procctl_reaper_status *rs)
{
struct proc *reap, *p2, *first_p;
sx_assert(&proctree_lock, SX_LOCKED);
bzero(rs, sizeof(*rs));
if ((p->p_treeflag & P_TREE_REAPER) == 0) {
reap = p->p_reaper;
} else {
reap = p;
rs->rs_flags |= REAPER_STATUS_OWNED;
}
if (reap == initproc)
rs->rs_flags |= REAPER_STATUS_REALINIT;
rs->rs_reaper = reap->p_pid;
rs->rs_descendants = 0;
rs->rs_children = 0;
if (!LIST_EMPTY(&reap->p_reaplist)) {
first_p = LIST_FIRST(&reap->p_children);
if (first_p == NULL)
first_p = LIST_FIRST(&reap->p_reaplist);
rs->rs_pid = first_p->p_pid;
LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
if (proc_realparent(p2) == reap)
rs->rs_children++;
rs->rs_descendants++;
}
} else {
rs->rs_pid = -1;
}
return (0);
}
static int
reap_getpids(struct thread *td, struct proc *p, struct procctl_reaper_pids *rp)
{
struct proc *reap, *p2;
struct procctl_reaper_pidinfo *pi, *pip;
u_int i, n;
int error;
sx_assert(&proctree_lock, SX_LOCKED);
PROC_UNLOCK(p);
reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
n = i = 0;
error = 0;
LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling)
n++;
sx_unlock(&proctree_lock);
if (rp->rp_count < n)
n = rp->rp_count;
pi = malloc(n * sizeof(*pi), M_TEMP, M_WAITOK);
sx_slock(&proctree_lock);
LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
if (i == n)
break;
pip = &pi[i];
bzero(pip, sizeof(*pip));
pip->pi_pid = p2->p_pid;
pip->pi_subtree = p2->p_reapsubtree;
pip->pi_flags = REAPER_PIDINFO_VALID;
if (proc_realparent(p2) == reap)
pip->pi_flags |= REAPER_PIDINFO_CHILD;
i++;
}
sx_sunlock(&proctree_lock);
error = copyout(pi, rp->rp_pids, i * sizeof(*pi));
free(pi, M_TEMP);
sx_slock(&proctree_lock);
PROC_LOCK(p);
return (error);
}
static int
reap_kill(struct thread *td, struct proc *p, struct procctl_reaper_kill *rk)
{
struct proc *reap, *p2;
ksiginfo_t ksi;
int error, error1;
sx_assert(&proctree_lock, SX_LOCKED);
if (IN_CAPABILITY_MODE(td))
return (ECAPMODE);
if (rk->rk_sig <= 0 || rk->rk_sig > _SIG_MAXSIG)
return (EINVAL);
if ((rk->rk_flags & ~REAPER_KILL_CHILDREN) != 0)
return (EINVAL);
PROC_UNLOCK(p);
reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
ksiginfo_init(&ksi);
ksi.ksi_signo = rk->rk_sig;
ksi.ksi_code = SI_USER;
ksi.ksi_pid = td->td_proc->p_pid;
ksi.ksi_uid = td->td_ucred->cr_ruid;
error = ESRCH;
rk->rk_killed = 0;
rk->rk_fpid = -1;
for (p2 = (rk->rk_flags & REAPER_KILL_CHILDREN) != 0 ?
LIST_FIRST(&reap->p_children) : LIST_FIRST(&reap->p_reaplist);
p2 != NULL;
p2 = (rk->rk_flags & REAPER_KILL_CHILDREN) != 0 ?
LIST_NEXT(p2, p_sibling) : LIST_NEXT(p2, p_reapsibling)) {
if ((rk->rk_flags & REAPER_KILL_SUBTREE) != 0 &&
p2->p_reapsubtree != rk->rk_subtree)
continue;
PROC_LOCK(p2);
error1 = p_cansignal(td, p2, rk->rk_sig);
if (error1 == 0) {
pksignal(p2, rk->rk_sig, &ksi);
rk->rk_killed++;
error = error1;
} else if (error == ESRCH) {
error = error1;
rk->rk_fpid = p2->p_pid;
}
PROC_UNLOCK(p2);
/* Do not end the loop on error, signal everything we can. */
}
PROC_LOCK(p);
return (error);
}
static int
trace_ctl(struct thread *td, struct proc *p, int state)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* Ktrace changes p_traceflag from or to zero under the
* process lock, so the test does not need to acquire ktrace
* mutex.
*/
if ((p->p_flag & P_TRACED) != 0 || p->p_traceflag != 0)
return (EBUSY);
switch (state) {
case PROC_TRACE_CTL_ENABLE:
if (td->td_proc != p)
return (EPERM);
p->p_flag2 &= ~(P2_NOTRACE | P2_NOTRACE_EXEC);
break;
case PROC_TRACE_CTL_DISABLE_EXEC:
p->p_flag2 |= P2_NOTRACE_EXEC | P2_NOTRACE;
break;
case PROC_TRACE_CTL_DISABLE:
if ((p->p_flag2 & P2_NOTRACE_EXEC) != 0) {
KASSERT((p->p_flag2 & P2_NOTRACE) != 0,
("dandling P2_NOTRACE_EXEC"));
if (td->td_proc != p)
return (EPERM);
p->p_flag2 &= ~P2_NOTRACE_EXEC;
} else {
p->p_flag2 |= P2_NOTRACE;
}
break;
default:
return (EINVAL);
}
return (0);
}
static int
trace_status(struct thread *td, struct proc *p, int *data)
{
if ((p->p_flag2 & P2_NOTRACE) != 0) {
KASSERT((p->p_flag & P_TRACED) == 0,
("%d traced but tracing disabled", p->p_pid));
*data = -1;
} else if ((p->p_flag & P_TRACED) != 0) {
*data = p->p_pptr->p_pid;
} else {
*data = 0;
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct procctl_args {
idtype_t idtype;
id_t id;
int com;
void *data;
};
#endif
/* ARGSUSED */
int
sys_procctl(struct thread *td, struct procctl_args *uap)
{
void *data;
union {
struct procctl_reaper_status rs;
struct procctl_reaper_pids rp;
struct procctl_reaper_kill rk;
} x;
int error, error1, flags;
switch (uap->com) {
case PROC_SPROTECT:
case PROC_TRACE_CTL:
error = copyin(uap->data, &flags, sizeof(flags));
if (error != 0)
return (error);
data = &flags;
break;
case PROC_REAP_ACQUIRE:
case PROC_REAP_RELEASE:
if (uap->data != NULL)
return (EINVAL);
data = NULL;
break;
case PROC_REAP_STATUS:
data = &x.rs;
break;
case PROC_REAP_GETPIDS:
error = copyin(uap->data, &x.rp, sizeof(x.rp));
if (error != 0)
return (error);
data = &x.rp;
break;
case PROC_REAP_KILL:
error = copyin(uap->data, &x.rk, sizeof(x.rk));
if (error != 0)
return (error);
data = &x.rk;
break;
case PROC_TRACE_STATUS:
data = &flags;
break;
default:
return (EINVAL);
}
error = kern_procctl(td, uap->idtype, uap->id, uap->com, data);
switch (uap->com) {
case PROC_REAP_STATUS:
if (error == 0)
error = copyout(&x.rs, uap->data, sizeof(x.rs));
break;
case PROC_REAP_KILL:
error1 = copyout(&x.rk, uap->data, sizeof(x.rk));
if (error == 0)
error = error1;
break;
case PROC_TRACE_STATUS:
if (error == 0)
error = copyout(&flags, uap->data, sizeof(flags));
break;
}
return (error);
}
static int
kern_procctl_single(struct thread *td, struct proc *p, int com, void *data)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
switch (com) {
case PROC_SPROTECT:
return (protect_set(td, p, *(int *)data));
case PROC_REAP_ACQUIRE:
return (reap_acquire(td, p));
case PROC_REAP_RELEASE:
return (reap_release(td, p));
case PROC_REAP_STATUS:
return (reap_status(td, p, data));
case PROC_REAP_GETPIDS:
return (reap_getpids(td, p, data));
case PROC_REAP_KILL:
return (reap_kill(td, p, data));
case PROC_TRACE_CTL:
return (trace_ctl(td, p, *(int *)data));
case PROC_TRACE_STATUS:
return (trace_status(td, p, data));
default:
return (EINVAL);
}
}
int
kern_procctl(struct thread *td, idtype_t idtype, id_t id, int com, void *data)
{
struct pgrp *pg;
struct proc *p;
int error, first_error, ok;
bool tree_locked;
switch (com) {
case PROC_REAP_ACQUIRE:
case PROC_REAP_RELEASE:
case PROC_REAP_STATUS:
case PROC_REAP_GETPIDS:
case PROC_REAP_KILL:
case PROC_TRACE_STATUS:
if (idtype != P_PID)
return (EINVAL);
}
switch (com) {
case PROC_SPROTECT:
case PROC_REAP_STATUS:
case PROC_REAP_GETPIDS:
case PROC_REAP_KILL:
case PROC_TRACE_CTL:
sx_slock(&proctree_lock);
tree_locked = true;
break;
case PROC_REAP_ACQUIRE:
case PROC_REAP_RELEASE:
sx_xlock(&proctree_lock);
tree_locked = true;
break;
case PROC_TRACE_STATUS:
tree_locked = false;
break;
default:
return (EINVAL);
}
switch (idtype) {
case P_PID:
p = pfind(id);
if (p == NULL) {
error = ESRCH;
break;
}
error = p_cansee(td, p);
if (error == 0)
error = kern_procctl_single(td, p, com, data);
PROC_UNLOCK(p);
break;
case P_PGID:
/*
* Attempt to apply the operation to all members of the
* group. Ignore processes in the group that can't be
* seen. Ignore errors so long as at least one process is
* able to complete the request successfully.
*/
pg = pgfind(id);
if (pg == NULL) {
error = ESRCH;
break;
}
PGRP_UNLOCK(pg);
ok = 0;
first_error = 0;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (p->p_state == PRS_NEW || p_cansee(td, p) != 0) {
PROC_UNLOCK(p);
continue;
}
error = kern_procctl_single(td, p, com, data);
PROC_UNLOCK(p);
if (error == 0)
ok = 1;
else if (first_error == 0)
first_error = error;
}
if (ok)
error = 0;
else if (first_error != 0)
error = first_error;
else
/*
* Was not able to see any processes in the
* process group.
*/
error = ESRCH;
break;
default:
error = EINVAL;
break;
}
if (tree_locked)
sx_unlock(&proctree_lock);
return (error);
}
