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1174 jermar 1
/*
2071 jermar 2
 * Copyright (c) 2006 Jakub Jermar
1174 jermar 3
 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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1888 jermar 29
/** @addtogroup generic	
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 * @{
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 */
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1264 jermar 33
/**
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 * @file	cap.c
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 * @brief	Capabilities control.
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 *
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 * @see cap.h
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 */
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1174 jermar 40
#include <security/cap.h>
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#include <proc/task.h>
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#include <synch/spinlock.h>
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#include <syscall/sysarg64.h>
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#include <syscall/copy.h>
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#include <arch.h>
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#include <errno.h>
1174 jermar 47
 
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/** Set capabilities.
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 *
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 * @param t Task whose capabilities are to be changed.
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 * @param caps New set of capabilities.
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 */
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void cap_set(task_t *t, cap_t caps)
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{
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	ipl_t ipl;
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	ipl = interrupts_disable();
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	spinlock_lock(&t->lock);
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	t->capabilities = caps;
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	spinlock_unlock(&t->lock);
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	interrupts_restore(ipl);
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}
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/** Get capabilities.
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 *
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 * @param t Task whose capabilities are to be returned.
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 * @return Task's capabilities.
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 */
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cap_t cap_get(task_t *t)
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{
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	ipl_t ipl;
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	cap_t caps;
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	ipl = interrupts_disable();
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	spinlock_lock(&t->lock);
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	caps = t->capabilities;
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	spinlock_unlock(&t->lock);
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	interrupts_restore(ipl);
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	return caps;
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}
1297 jermar 86
 
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/** Grant capabilities to a task.
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 *
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 * The calling task must have the CAP_CAP capability.
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 *
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 * @param uspace_taskid_arg Userspace structure holding destination task ID.
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 * @param caps Capabilities to grant.
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 *
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 * @return Zero on success or an error code from @ref errno.h.
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 */
1780 jermar 96
unative_t sys_cap_grant(sysarg64_t *uspace_taskid_arg, cap_t caps)
1297 jermar 97
{
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	sysarg64_t taskid_arg;
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	task_t *t;
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	ipl_t ipl;
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	int rc;
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	if (!(cap_get(TASK) & CAP_CAP))
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		return (unative_t) EPERM;
1297 jermar 105
 
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	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
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	if (rc != 0)
1780 jermar 108
		return (unative_t) rc;
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	ipl = interrupts_disable();
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	spinlock_lock(&tasks_lock);
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	t = task_find_by_id((task_id_t) taskid_arg.value);
1839 decky 113
	if ((!t) || (!context_check(CONTEXT, t->context))) {
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		spinlock_unlock(&tasks_lock);
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		interrupts_restore(ipl);
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		return (unative_t) ENOENT;
1297 jermar 117
	}
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1588 jermar 119
	spinlock_lock(&t->lock);
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	cap_set(t, cap_get(t) | caps);
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	spinlock_unlock(&t->lock);
1297 jermar 122
 
1588 jermar 123
	spinlock_unlock(&tasks_lock);
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	interrupts_restore(ipl);	
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	return 0;
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}
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/** Revoke capabilities from a task.
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 *
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 * The calling task must have the CAP_CAP capability or the caller must
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 * attempt to revoke capabilities from itself.
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 *
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 * @param uspace_taskid_arg Userspace structure holding destination task ID.
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 * @param caps Capabilities to revoke.
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 *
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 * @return Zero on success or an error code from @ref errno.h.
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 */
1780 jermar 138
unative_t sys_cap_revoke(sysarg64_t *uspace_taskid_arg, cap_t caps)
1297 jermar 139
{
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	sysarg64_t taskid_arg;
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	task_t *t;
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	ipl_t ipl;
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	int rc;
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145
	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
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	if (rc != 0)
1780 jermar 147
		return (unative_t) rc;
1297 jermar 148
 
149
	ipl = interrupts_disable();
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	spinlock_lock(&tasks_lock);	
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	t = task_find_by_id((task_id_t) taskid_arg.value);
1839 decky 152
	if ((!t) || (!context_check(CONTEXT, t->context))) {
1297 jermar 153
		spinlock_unlock(&tasks_lock);
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		interrupts_restore(ipl);
1780 jermar 155
		return (unative_t) ENOENT;
1297 jermar 156
	}
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158
	/*
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	 * Revoking capabilities is different from granting them in that
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	 * a task can revoke capabilities from itself even if it
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	 * doesn't have CAP_CAP.
162
	 */
163
	if (!(cap_get(TASK) & CAP_CAP) || !(t == TASK)) {
1588 jermar 164
		spinlock_unlock(&tasks_lock);
1297 jermar 165
		interrupts_restore(ipl);
1780 jermar 166
		return (unative_t) EPERM;
1297 jermar 167
	}
1588 jermar 168
 
169
	spinlock_lock(&t->lock);
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	cap_set(t, cap_get(t) & ~caps);
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	spinlock_unlock(&t->lock);
1297 jermar 172
 
1588 jermar 173
	spinlock_unlock(&tasks_lock);
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1297 jermar 175
	interrupts_restore(ipl);
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	return 0;
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}
1702 cejka 178
 
1888 jermar 179
/** @}
1702 cejka 180
 */
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