WebSVN – HelenOS – Blame – //trunk/kernel/generic/src/security/cap.c

Rev	Author	Line No.	Line
1174	jermar	1	/*
		2	* Copyright (C) 2006 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		13	* documentation and/or other materials provided with the distribution.
		14	* - The name of the author may not be used to endorse or promote products
		15	* derived from this software without specific prior written permission.
		16	*
		17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
1702	cejka	29	/** @addtogroup generic
		30	* @{
		31	*/
		32
1264	jermar	33	/**
		34	* @file cap.c
		35	* @brief Capabilities control.
		36	*
		37	* @see cap.h
		38	*/
		39
1174	jermar	40	#include <security/cap.h>
		41	#include <proc/task.h>
		42	#include <synch/spinlock.h>
1297	jermar	43	#include <syscall/sysarg64.h>
		44	#include <syscall/copy.h>
1174	jermar	45	#include <arch.h>
		46	#include <typedefs.h>
1297	jermar	47	#include <errno.h>
1174	jermar	48
		49	/** Set capabilities.
		50	*
		51	* @param t Task whose capabilities are to be changed.
		52	* @param caps New set of capabilities.
		53	*/
		54	void cap_set(task_t *t, cap_t caps)
		55	{
		56	ipl_t ipl;
		57
		58	ipl = interrupts_disable();
		59	spinlock_lock(&t->lock);
		60
		61	t->capabilities = caps;
		62
		63	spinlock_unlock(&t->lock);
		64	interrupts_restore(ipl);
		65	}
		66
		67	/** Get capabilities.
		68	*
		69	* @param t Task whose capabilities are to be returned.
		70	* @return Task's capabilities.
		71	*/
		72	cap_t cap_get(task_t *t)
		73	{
		74	ipl_t ipl;
		75	cap_t caps;
		76
		77	ipl = interrupts_disable();
		78	spinlock_lock(&t->lock);
		79
		80	caps = t->capabilities;
		81
		82	spinlock_unlock(&t->lock);
		83	interrupts_restore(ipl);
		84
		85	return caps;
		86	}
1297	jermar	87
		88	/** Grant capabilities to a task.
		89	*
		90	* The calling task must have the CAP_CAP capability.
		91	*
		92	* @param uspace_taskid_arg Userspace structure holding destination task ID.
		93	* @param caps Capabilities to grant.
		94	*
		95	* @return Zero on success or an error code from @ref errno.h.
		96	*/
1780	jermar	97	unative_t sys_cap_grant(sysarg64_t *uspace_taskid_arg, cap_t caps)
1297	jermar	98	{
		99	sysarg64_t taskid_arg;
		100	task_t *t;
		101	ipl_t ipl;
		102	int rc;
		103
		104	if (!(cap_get(TASK) & CAP_CAP))
1780	jermar	105	return (unative_t) EPERM;
1297	jermar	106
		107	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
		108	if (rc != 0)
1780	jermar	109	return (unative_t) rc;
1297	jermar	110
		111	ipl = interrupts_disable();
		112	spinlock_lock(&tasks_lock);
		113	t = task_find_by_id((task_id_t) taskid_arg.value);
		114	if (!t) {
		115	spinlock_unlock(&tasks_lock);
		116	interrupts_restore(ipl);
1780	jermar	117	return (unative_t) ENOENT;
1297	jermar	118	}
		119
1588	jermar	120	spinlock_lock(&t->lock);
1297	jermar	121	cap_set(t, cap_get(t) \| caps);
1588	jermar	122	spinlock_unlock(&t->lock);
1297	jermar	123
1588	jermar	124	spinlock_unlock(&tasks_lock);
		125
		126
		127
1297	jermar	128	interrupts_restore(ipl);
		129	return 0;
		130	}
		131
		132	/** Revoke capabilities from a task.
		133	*
		134	* The calling task must have the CAP_CAP capability or the caller must
		135	* attempt to revoke capabilities from itself.
		136	*
		137	* @param uspace_taskid_arg Userspace structure holding destination task ID.
		138	* @param caps Capabilities to revoke.
		139	*
		140	* @return Zero on success or an error code from @ref errno.h.
		141	*/
1780	jermar	142	unative_t sys_cap_revoke(sysarg64_t *uspace_taskid_arg, cap_t caps)
1297	jermar	143	{
		144	sysarg64_t taskid_arg;
		145	task_t *t;
		146	ipl_t ipl;
		147	int rc;
		148
		149	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
		150	if (rc != 0)
1780	jermar	151	return (unative_t) rc;
1297	jermar	152
		153	ipl = interrupts_disable();
		154	spinlock_lock(&tasks_lock);
		155	t = task_find_by_id((task_id_t) taskid_arg.value);
		156	if (!t) {
		157	spinlock_unlock(&tasks_lock);
		158	interrupts_restore(ipl);
1780	jermar	159	return (unative_t) ENOENT;
1297	jermar	160	}
		161
		162	/*
		163	* Revoking capabilities is different from granting them in that
		164	* a task can revoke capabilities from itself even if it
		165	* doesn't have CAP_CAP.
		166	*/
		167	if (!(cap_get(TASK) & CAP_CAP) \|\| !(t == TASK)) {
1588	jermar	168	spinlock_unlock(&tasks_lock);
1297	jermar	169	interrupts_restore(ipl);
1780	jermar	170	return (unative_t) EPERM;
1297	jermar	171	}
1588	jermar	172
		173	spinlock_lock(&t->lock);
		174	cap_set(t, cap_get(t) & ~caps);
		175	spinlock_unlock(&t->lock);
1297	jermar	176
1588	jermar	177	spinlock_unlock(&tasks_lock);
		178
1297	jermar	179	interrupts_restore(ipl);
		180	return 0;
		181	}
1702	cejka	182
		183	/** @}
		184	*/
		185

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(root)//trunk/kernel/generic/src/security/cap.c – Rev 1787