WebSVN – HelenOS-historic – Blame – /kernel/trunk/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
1264	jermar	29	/**
		30	* @file cap.c
		31	* @brief Capabilities control.
		32	*
		33	* @see cap.h
		34	*/
		35
1174	jermar	36	#include <security/cap.h>
		37	#include <proc/task.h>
		38	#include <synch/spinlock.h>
1297	jermar	39	#include <syscall/sysarg64.h>
		40	#include <syscall/copy.h>
1174	jermar	41	#include <arch.h>
		42	#include <typedefs.h>
1297	jermar	43	#include <errno.h>
1174	jermar	44
		45	/** Set capabilities.
		46	*
		47	* @param t Task whose capabilities are to be changed.
		48	* @param caps New set of capabilities.
		49	*/
		50	void cap_set(task_t *t, cap_t caps)
		51	{
		52	ipl_t ipl;
		53
		54	ipl = interrupts_disable();
		55	spinlock_lock(&t->lock);
		56
		57	t->capabilities = caps;
		58
		59	spinlock_unlock(&t->lock);
		60	interrupts_restore(ipl);
		61	}
		62
		63	/** Get capabilities.
		64	*
		65	* @param t Task whose capabilities are to be returned.
		66	* @return Task's capabilities.
		67	*/
		68	cap_t cap_get(task_t *t)
		69	{
		70	ipl_t ipl;
		71	cap_t caps;
		72
		73	ipl = interrupts_disable();
		74	spinlock_lock(&t->lock);
		75
		76	caps = t->capabilities;
		77
		78	spinlock_unlock(&t->lock);
		79	interrupts_restore(ipl);
		80
		81	return caps;
		82	}
1297	jermar	83
		84	/** Grant capabilities to a task.
		85	*
		86	* The calling task must have the CAP_CAP capability.
		87	*
		88	* @param uspace_taskid_arg Userspace structure holding destination task ID.
		89	* @param caps Capabilities to grant.
		90	*
		91	* @return Zero on success or an error code from @ref errno.h.
		92	*/
		93	__native sys_cap_grant(sysarg64_t *uspace_taskid_arg, cap_t caps)
		94	{
		95	sysarg64_t taskid_arg;
		96	task_t *t;
		97	ipl_t ipl;
		98	int rc;
		99
		100	if (!(cap_get(TASK) & CAP_CAP))
		101	return (__native) EPERM;
		102
		103	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
		104	if (rc != 0)
		105	return (__native) rc;
		106
		107	ipl = interrupts_disable();
		108	spinlock_lock(&tasks_lock);
		109	t = task_find_by_id((task_id_t) taskid_arg.value);
		110	if (!t) {
		111	spinlock_unlock(&tasks_lock);
		112	interrupts_restore(ipl);
		113	return (__native) ENOENT;
		114	}
		115
1588	jermar	116	spinlock_lock(&t->lock);
1297	jermar	117	cap_set(t, cap_get(t) \| caps);
1588	jermar	118	spinlock_unlock(&t->lock);
1297	jermar	119
1588	jermar	120	spinlock_unlock(&tasks_lock);
		121
		122
		123
1297	jermar	124	interrupts_restore(ipl);
		125	return 0;
		126	}
		127
		128	/** Revoke capabilities from a task.
		129	*
		130	* The calling task must have the CAP_CAP capability or the caller must
		131	* attempt to revoke capabilities from itself.
		132	*
		133	* @param uspace_taskid_arg Userspace structure holding destination task ID.
		134	* @param caps Capabilities to revoke.
		135	*
		136	* @return Zero on success or an error code from @ref errno.h.
		137	*/
		138	__native sys_cap_revoke(sysarg64_t *uspace_taskid_arg, cap_t caps)
		139	{
		140	sysarg64_t taskid_arg;
		141	task_t *t;
		142	ipl_t ipl;
		143	int rc;
		144
		145	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
		146	if (rc != 0)
		147	return (__native) rc;
		148
		149	ipl = interrupts_disable();
		150	spinlock_lock(&tasks_lock);
		151	t = task_find_by_id((task_id_t) taskid_arg.value);
		152	if (!t) {
		153	spinlock_unlock(&tasks_lock);
		154	interrupts_restore(ipl);
		155	return (__native) ENOENT;
		156	}
		157
		158	/*
		159	* Revoking capabilities is different from granting them in that
		160	* a task can revoke capabilities from itself even if it
		161	* 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);
		166	return (__native) EPERM;
		167	}
1588	jermar	168
		169	spinlock_lock(&t->lock);
		170	cap_set(t, cap_get(t) & ~caps);
		171	spinlock_unlock(&t->lock);
1297	jermar	172
1588	jermar	173	spinlock_unlock(&tasks_lock);
		174
1297	jermar	175	interrupts_restore(ipl);
		176	return 0;
		177	}

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(root)/kernel/trunk/generic/src/security/cap.c – Rev 1588