usr/src/uts/common/syscall/ppriv.c - illumos-gate - Gitiles

 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License (the "License").
  * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */

 #pragma ident	"%Z%%M%	%I%	%E% SMI"

 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/sysmacros.h>
 #include <sys/systm.h>
 #include <sys/cred_impl.h>
 #include <sys/errno.h>
 #include <sys/proc.h>
 #include <sys/priv_impl.h>
 #include <sys/policy.h>
 #include <sys/ddi.h>
 #include <sys/thread.h>
 #include <c2/audit.h>

 /*
  * System call support for manipulating privileges.
  *
  *
  * setppriv(2) - set process privilege set
  * getppriv(2) - get process privilege set
  * getprivimplinfo(2) - get process privilege implementation information
  * setpflags(2) - set process (privilege) flags
  * getpflags(2) - get process (privilege) flags
  */

 /*
  * setppriv (priv_op_t, priv_ptype_t, priv_set_t)
  */
 static int
 setppriv(priv_op_t op, priv_ptype_t type, priv_set_t *in_pset)
 {
 	priv_set_t	pset, *target;
 	cred_t		*cr, *pcr;
 	proc_t		*p;
 	boolean_t	donocd;

 	if (!PRIV_VALIDSET(type) || !PRIV_VALIDOP(op))
 		return (set_errno(EINVAL));

 	if (copyin(in_pset, &pset, sizeof (priv_set_t)))
 		return (set_errno(EFAULT));

 	p = ttoproc(curthread);
 	cr = cralloc();
 	mutex_enter(&p->p_crlock);

 	pcr = p->p_cred;

 #ifdef C2_AUDIT
 	if (audit_active)
 		audit_setppriv(op, type, &pset, pcr);
 #endif

 	/*
 	 * Filter out unallowed request (bad op and bad type)
 	 */
 	switch (op) {
 	case PRIV_ON:
 	case PRIV_SET:
 		/*
 		 * Turning on privileges; the limit set cannot grow,
 		 * other sets can but only as long as they remain subsets
 		 * of P.  Only immediately after exec holds that P <= L.
 		 */
 		if (((type == PRIV_LIMIT &&
 			!priv_issubset(&pset, &CR_LPRIV(pcr))) ||
 		    !priv_issubset(&pset, &CR_OPPRIV(pcr))) &&
 		    !priv_issubset(&pset, priv_getset(pcr, type))) {
 			mutex_exit(&p->p_crlock);
 			crfree(cr);
 			return (set_errno(EPERM));
 		}
 		break;

 	case PRIV_OFF:
 		/* PRIV_OFF is always allowed */
 		break;
 	}

 	/*
 	 * OK! everything is cool.
 	 * Do cred COW.
 	 */
 	crcopy_to(pcr, cr);

 	/*
 	 * If we change the effective, permitted or limit set, we attain
 	 * "privilege awareness".
 	 */
 	if (type != PRIV_INHERITABLE)
 		priv_set_PA(cr);

 	target = &(CR_PRIVS(cr)->crprivs[type]);

 	switch (op) {
 	case PRIV_ON:
 		priv_union(&pset, target);
 		break;
 	case PRIV_OFF:
 		priv_inverse(&pset);
 		priv_intersect(target, &pset);

 		/*
 		 * Fall-thru to set target and change other process
 		 * privilege sets.
 		 */
 		/*FALLTHRU*/

 	case PRIV_SET:
 		*target = pset;

 		/*
 		 * Take privileges no longer permitted out
 		 * of other effective sets as well.
 		 * Limit set is enforced at exec() time.
 		 */
 		if (type == PRIV_PERMITTED)
 			priv_intersect(&pset, &CR_EPRIV(cr));
 		break;
 	}

 	/*
 	 * When we give up privileges not in the inheritable set,
 	 * set SNOCD if not already set; first we compute the
 	 * privileges removed from P using Diff = (~P') & P
 	 * and then we check whether the removed privileges are
 	 * a subset of I.  If we retain uid 0, all privileges
 	 * are required anyway so don't set SNOCD.
 	 */
 	if (type == PRIV_PERMITTED && (p->p_flag & SNOCD) == 0 &&
 	    cr->cr_uid != 0 && cr->cr_ruid != 0 && cr->cr_suid != 0) {
 		priv_set_t diff = CR_OPPRIV(cr);
 		priv_inverse(&diff);
 		priv_intersect(&CR_OPPRIV(pcr), &diff);
 		donocd = !priv_issubset(&diff, &CR_IPRIV(cr));
 	} else {
 		donocd = B_FALSE;
 	}

 	p->p_cred = cr;
 	mutex_exit(&p->p_crlock);

 	if (donocd) {
 		mutex_enter(&p->p_lock);
 		p->p_flag |= SNOCD;
 		mutex_exit(&p->p_lock);
 	}

 	crset(p, cr);		/* broadcast to process threads */

 	return (0);
 }

 /*
  * getppriv (priv_ptype_t, priv_set_t *)
  */
 static int
 getppriv(priv_ptype_t type, priv_set_t *pset)
 {
 	if (!PRIV_VALIDSET(type))
 		return (set_errno(EINVAL));

 	if (copyout(priv_getset(CRED(), type), pset, sizeof (priv_set_t)) != 0)
 		return (set_errno(EFAULT));

 	return (0);
 }

 static int
 getprivimplinfo(void *buf, size_t bufsize)
 {
 	int err;

 	err = copyout(priv_hold_implinfo(), buf, min(bufsize, privinfosize));

 	priv_release_implinfo();

 	if (err)
 		return (set_errno(EFAULT));

 	return (0);
 }

 /*
  * Set process flags in the given target cred.  If NULL is specified, then
  * CRED() is used; otherwise the cred is assumed to be modifiable (i.e. newly
  * crdup'ed, or equivalent).  Some flags are set in the proc rather than cred;
  * for these, curproc is always used.
  *
  * For now we cheat: the flags are actually bit masks so we can simplify
  * some; we do make sure that the arguments are valid, though.
  */

 int
 setpflags(uint_t flag, uint_t val, cred_t *tcr)
 {
 	cred_t *cr, *pcr;
 	proc_t *p = curproc;
 	uint_t newflags;
 	boolean_t use_curcred = (tcr == NULL);

 	if (val > 1 || (flag != PRIV_DEBUG && flag != PRIV_AWARE &&
 	    flag != NET_MAC_AWARE && flag != NET_MAC_AWARE_INHERIT &&
 	    flag != __PROC_PROTECT)) {
 		return (EINVAL);
 	}

 	if (flag == __PROC_PROTECT) {
 		mutex_enter(&p->p_lock);
 		if (val == 0)
 			p->p_flag &= ~SNOCD;
 		else
 			p->p_flag |= SNOCD;
 		mutex_exit(&p->p_lock);
 		return (0);
 	}

 	if (use_curcred) {
 		cr = cralloc();
 		mutex_enter(&p->p_crlock);
 		pcr = p->p_cred;
 	} else {
 		cr = pcr = tcr;
 	}

 	newflags = CR_FLAGS(pcr);

 	if (val != 0)
 		newflags |= flag;
 	else
 		newflags &= ~flag;

 	/* No change */
 	if (CR_FLAGS(pcr) == newflags) {
 		if (use_curcred) {
 			mutex_exit(&p->p_crlock);
 			crfree(cr);
 		}
 		return (0);
 	}

 	/*
 	 * Need net_mac_aware priv to turn either net_mac_aware* flag on
 	 * current cred.
 	 */
 	if ((flag == NET_MAC_AWARE || flag == NET_MAC_AWARE_INHERIT) &&
 	    (val == 1) && use_curcred) {
 		if (secpolicy_net_mac_aware(cr) != 0) {
 			mutex_exit(&p->p_crlock);
 			crfree(cr);
 			return (EPERM);
 		}
 	}

 	/* Trying to unset PA; if we can't, return an error */
 	if (flag == PRIV_AWARE && val == 0 && !priv_can_clear_PA(pcr)) {
 		if (use_curcred) {
 			mutex_exit(&p->p_crlock);
 			crfree(cr);
 		}
 		return (EPERM);
 	}

 	/* Committed to changing the flag */
 	if (use_curcred)
 		crcopy_to(pcr, cr);
 	if (flag == PRIV_AWARE) {
 		if (val != 0)
 			priv_set_PA(cr);
 		else
 			priv_adjust_PA(cr);
 	} else {
 		CR_FLAGS(cr) = newflags;
 	}

 	if (use_curcred) {
 		p->p_cred = cr;
 		mutex_exit(&p->p_crlock);
 		crset(p, cr);
 	}

 	return (0);
 }

 /*
  * Getpflags.  Currently only implements single bit flags.
  */
 uint_t
 getpflags(uint_t flag, const cred_t *cr)
 {
 	if (flag != PRIV_DEBUG && flag != PRIV_AWARE &&
 	    flag != NET_MAC_AWARE && flag != NET_MAC_AWARE_INHERIT)
 		return ((uint_t)-1);

 	return ((CR_FLAGS(cr) & flag) != 0);
 }

 /*
  * Privilege system call entry point
  */
 int
 privsys(int code, priv_op_t op, priv_ptype_t type, void *buf, size_t bufsize)
 {
 	int retv;

 	switch (code) {
 	case PRIVSYS_SETPPRIV:
 		if (bufsize < sizeof (priv_set_t))
 			return (set_errno(ENOMEM));
 		return (setppriv(op, type, buf));
 	case PRIVSYS_GETPPRIV:
 		if (bufsize < sizeof (priv_set_t))
 			return (set_errno(ENOMEM));
 		return (getppriv(type, buf));
 	case PRIVSYS_GETIMPLINFO:
 		return (getprivimplinfo(buf, bufsize));
 	case PRIVSYS_SETPFLAGS:
 		retv = setpflags((uint_t)op, (uint_t)type, NULL);
 		return (retv != 0 ? set_errno(retv) : 0);
 	case PRIVSYS_GETPFLAGS:
 		retv = (int)getpflags((uint_t)op, CRED());
 		return (retv == -1 ? set_errno(EINVAL) : retv);
 	}
 	return (set_errno(EINVAL));
 }

 #ifdef _SYSCALL32_IMPL
 int
 privsys32(int code, priv_op_t op, priv_ptype_t type, caddr32_t *buf,
     size32_t bufsize)
 {
 	return (privsys(code, op, type, (void *)buf, (size_t)bufsize));
 }
 #endif
	/*
	* CDDL HEADER START
	*
	* The contents of this file are subject to the terms of the
	* Common Development and Distribution License (the "License").
	* You may not use this file except in compliance with the License.
	*
	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	* or http://www.opensolaris.org/os/licensing.
	* See the License for the specific language governing permissions
	* and limitations under the License.
	*
	* When distributing Covered Code, include this CDDL HEADER in each
	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	* If applicable, add the following below this CDDL HEADER, with the
	* fields enclosed by brackets "[]" replaced with your own identifying
	* information: Portions Copyright [yyyy] [name of copyright owner]
	*
	* CDDL HEADER END
	*/
	/*
	* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
	* Use is subject to license terms.
	*/

	#pragma ident "%Z%%M% %I% %E% SMI"

	#include <sys/param.h>
	#include <sys/types.h>
	#include <sys/sysmacros.h>
	#include <sys/systm.h>
	#include <sys/cred_impl.h>
	#include <sys/errno.h>
	#include <sys/proc.h>
	#include <sys/priv_impl.h>
	#include <sys/policy.h>
	#include <sys/ddi.h>
	#include <sys/thread.h>
	#include <c2/audit.h>

	/*
	* System call support for manipulating privileges.
	*
	*
	* setppriv(2) - set process privilege set
	* getppriv(2) - get process privilege set
	* getprivimplinfo(2) - get process privilege implementation information
	* setpflags(2) - set process (privilege) flags
	* getpflags(2) - get process (privilege) flags
	*/

	/*
	* setppriv (priv_op_t, priv_ptype_t, priv_set_t)
	*/
	static int
	setppriv(priv_op_t op, priv_ptype_t type, priv_set_t *in_pset)
	{
	priv_set_t pset, *target;
	cred_t cr, pcr;
	proc_t *p;
	boolean_t donocd;

	if (!PRIV_VALIDSET(type) \|\| !PRIV_VALIDOP(op))
	return (set_errno(EINVAL));

	if (copyin(in_pset, &pset, sizeof (priv_set_t)))
	return (set_errno(EFAULT));

	p = ttoproc(curthread);
	cr = cralloc();
	mutex_enter(&p->p_crlock);

	pcr = p->p_cred;

	#ifdef C2_AUDIT
	if (audit_active)
	audit_setppriv(op, type, &pset, pcr);
	#endif

	/*
	* Filter out unallowed request (bad op and bad type)
	*/
	switch (op) {
	case PRIV_ON:
	case PRIV_SET:
	/*
	* Turning on privileges; the limit set cannot grow,
	* other sets can but only as long as they remain subsets
	* of P. Only immediately after exec holds that P <= L.
	*/
	if (((type == PRIV_LIMIT &&
	!priv_issubset(&pset, &CR_LPRIV(pcr))) \|\|
	!priv_issubset(&pset, &CR_OPPRIV(pcr))) &&
	!priv_issubset(&pset, priv_getset(pcr, type))) {
	mutex_exit(&p->p_crlock);
	crfree(cr);
	return (set_errno(EPERM));
	}
	break;

	case PRIV_OFF:
	/* PRIV_OFF is always allowed */
	break;
	}

	/*
	* OK! everything is cool.
	* Do cred COW.
	*/
	crcopy_to(pcr, cr);

	/*
	* If we change the effective, permitted or limit set, we attain
	* "privilege awareness".
	*/
	if (type != PRIV_INHERITABLE)
	priv_set_PA(cr);

	target = &(CR_PRIVS(cr)->crprivs[type]);

	switch (op) {
	case PRIV_ON:
	priv_union(&pset, target);
	break;
	case PRIV_OFF:
	priv_inverse(&pset);
	priv_intersect(target, &pset);

	/*
	* Fall-thru to set target and change other process
	* privilege sets.
	*/
	/FALLTHRU/

	case PRIV_SET:
	*target = pset;

	/*
	* Take privileges no longer permitted out
	* of other effective sets as well.
	* Limit set is enforced at exec() time.
	*/
	if (type == PRIV_PERMITTED)
	priv_intersect(&pset, &CR_EPRIV(cr));
	break;
	}

	/*
	* When we give up privileges not in the inheritable set,
	* set SNOCD if not already set; first we compute the
	* privileges removed from P using Diff = (~P') & P
	* and then we check whether the removed privileges are
	* a subset of I. If we retain uid 0, all privileges
	* are required anyway so don't set SNOCD.
	*/
	if (type == PRIV_PERMITTED && (p->p_flag & SNOCD) == 0 &&
	cr->cr_uid != 0 && cr->cr_ruid != 0 && cr->cr_suid != 0) {
	priv_set_t diff = CR_OPPRIV(cr);
	priv_inverse(&diff);
	priv_intersect(&CR_OPPRIV(pcr), &diff);
	donocd = !priv_issubset(&diff, &CR_IPRIV(cr));
	} else {
	donocd = B_FALSE;
	}

	p->p_cred = cr;
	mutex_exit(&p->p_crlock);

	if (donocd) {
	mutex_enter(&p->p_lock);
	p->p_flag \|= SNOCD;
	mutex_exit(&p->p_lock);
	}

	crset(p, cr); /* broadcast to process threads */

	return (0);
	}

	/*
	* getppriv (priv_ptype_t, priv_set_t *)
	*/
	static int
	getppriv(priv_ptype_t type, priv_set_t *pset)
	{
	if (!PRIV_VALIDSET(type))
	return (set_errno(EINVAL));

	if (copyout(priv_getset(CRED(), type), pset, sizeof (priv_set_t)) != 0)
	return (set_errno(EFAULT));

	return (0);
	}

	static int
	getprivimplinfo(void *buf, size_t bufsize)
	{
	int err;

	err = copyout(priv_hold_implinfo(), buf, min(bufsize, privinfosize));

	priv_release_implinfo();

	if (err)
	return (set_errno(EFAULT));

	return (0);
	}

	/*
	* Set process flags in the given target cred. If NULL is specified, then
	* CRED() is used; otherwise the cred is assumed to be modifiable (i.e. newly
	* crdup'ed, or equivalent). Some flags are set in the proc rather than cred;
	* for these, curproc is always used.
	*
	* For now we cheat: the flags are actually bit masks so we can simplify
	* some; we do make sure that the arguments are valid, though.
	*/

	int
	setpflags(uint_t flag, uint_t val, cred_t *tcr)
	{
	cred_t cr, pcr;
	proc_t *p = curproc;
	uint_t newflags;
	boolean_t use_curcred = (tcr == NULL);

	if (val > 1 \|\| (flag != PRIV_DEBUG && flag != PRIV_AWARE &&
	flag != NET_MAC_AWARE && flag != NET_MAC_AWARE_INHERIT &&
	flag != __PROC_PROTECT)) {
	return (EINVAL);
	}

	if (flag == __PROC_PROTECT) {
	mutex_enter(&p->p_lock);
	if (val == 0)
	p->p_flag &= ~SNOCD;
	else
	p->p_flag \|= SNOCD;
	mutex_exit(&p->p_lock);
	return (0);
	}

	if (use_curcred) {
	cr = cralloc();
	mutex_enter(&p->p_crlock);
	pcr = p->p_cred;
	} else {
	cr = pcr = tcr;
	}

	newflags = CR_FLAGS(pcr);

	if (val != 0)
	newflags \|= flag;
	else
	newflags &= ~flag;

	/* No change */
	if (CR_FLAGS(pcr) == newflags) {
	if (use_curcred) {
	mutex_exit(&p->p_crlock);
	crfree(cr);
	}
	return (0);
	}

	/*
	* Need net_mac_aware priv to turn either net_mac_aware* flag on
	* current cred.
	*/
	if ((flag == NET_MAC_AWARE \|\| flag == NET_MAC_AWARE_INHERIT) &&
	(val == 1) && use_curcred) {
	if (secpolicy_net_mac_aware(cr) != 0) {
	mutex_exit(&p->p_crlock);
	crfree(cr);
	return (EPERM);
	}
	}

	/* Trying to unset PA; if we can't, return an error */
	if (flag == PRIV_AWARE && val == 0 && !priv_can_clear_PA(pcr)) {
	if (use_curcred) {
	mutex_exit(&p->p_crlock);
	crfree(cr);
	}
	return (EPERM);
	}

	/* Committed to changing the flag */
	if (use_curcred)
	crcopy_to(pcr, cr);
	if (flag == PRIV_AWARE) {
	if (val != 0)
	priv_set_PA(cr);
	else
	priv_adjust_PA(cr);
	} else {
	CR_FLAGS(cr) = newflags;
	}

	if (use_curcred) {
	p->p_cred = cr;
	mutex_exit(&p->p_crlock);
	crset(p, cr);
	}

	return (0);
	}

	/*
	* Getpflags. Currently only implements single bit flags.
	*/
	uint_t
	getpflags(uint_t flag, const cred_t *cr)
	{
	if (flag != PRIV_DEBUG && flag != PRIV_AWARE &&
	flag != NET_MAC_AWARE && flag != NET_MAC_AWARE_INHERIT)
	return ((uint_t)-1);

	return ((CR_FLAGS(cr) & flag) != 0);
	}

	/*
	* Privilege system call entry point
	*/
	int
	privsys(int code, priv_op_t op, priv_ptype_t type, void *buf, size_t bufsize)
	{
	int retv;

	switch (code) {
	case PRIVSYS_SETPPRIV:
	if (bufsize < sizeof (priv_set_t))
	return (set_errno(ENOMEM));
	return (setppriv(op, type, buf));
	case PRIVSYS_GETPPRIV:
	if (bufsize < sizeof (priv_set_t))
	return (set_errno(ENOMEM));
	return (getppriv(type, buf));
	case PRIVSYS_GETIMPLINFO:
	return (getprivimplinfo(buf, bufsize));
	case PRIVSYS_SETPFLAGS:
	retv = setpflags((uint_t)op, (uint_t)type, NULL);
	return (retv != 0 ? set_errno(retv) : 0);
	case PRIVSYS_GETPFLAGS:
	retv = (int)getpflags((uint_t)op, CRED());
	return (retv == -1 ? set_errno(EINVAL) : retv);
	}
	return (set_errno(EINVAL));
	}

	#ifdef _SYSCALL32_IMPL
	int
	privsys32(int code, priv_op_t op, priv_ptype_t type, caddr32_t *buf,
	size32_t bufsize)
	{
	return (privsys(code, op, type, (void *)buf, (size_t)bufsize));
	}
	#endif