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);
1839	decky	114	if ((!t) \|\| (!context_check(CONTEXT, t->context))) {
1297	jermar	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);
1297	jermar	125	interrupts_restore(ipl);
		126	return 0;
		127	}
		128
		129	/** Revoke capabilities from a task.
		130	*
		131	* The calling task must have the CAP_CAP capability or the caller must
		132	* attempt to revoke capabilities from itself.
		133	*
		134	* @param uspace_taskid_arg Userspace structure holding destination task ID.
		135	* @param caps Capabilities to revoke.
		136	*
		137	* @return Zero on success or an error code from @ref errno.h.
		138	*/
1780	jermar	139	unative_t sys_cap_revoke(sysarg64_t *uspace_taskid_arg, cap_t caps)
1297	jermar	140	{
		141	sysarg64_t taskid_arg;
		142	task_t *t;
		143	ipl_t ipl;
		144	int rc;
		145
		146	rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
		147	if (rc != 0)
1780	jermar	148	return (unative_t) rc;
1297	jermar	149
		150	ipl = interrupts_disable();
		151	spinlock_lock(&tasks_lock);
		152	t = task_find_by_id((task_id_t) taskid_arg.value);
1839	decky	153	if ((!t) \|\| (!context_check(CONTEXT, t->context))) {
1297	jermar	154	spinlock_unlock(&tasks_lock);
		155	interrupts_restore(ipl);
1780	jermar	156	return (unative_t) ENOENT;
1297	jermar	157	}
		158
		159	/*
		160	* Revoking capabilities is different from granting them in that
		161	* a task can revoke capabilities from itself even if it
		162	* doesn't have CAP_CAP.
		163	*/
		164	if (!(cap_get(TASK) & CAP_CAP) \|\| !(t == TASK)) {
1588	jermar	165	spinlock_unlock(&tasks_lock);
1297	jermar	166	interrupts_restore(ipl);
1780	jermar	167	return (unative_t) EPERM;
1297	jermar	168	}
1588	jermar	169
		170	spinlock_lock(&t->lock);
		171	cap_set(t, cap_get(t) & ~caps);
		172	spinlock_unlock(&t->lock);
1297	jermar	173
1588	jermar	174	spinlock_unlock(&tasks_lock);
		175
1297	jermar	176	interrupts_restore(ipl);
		177	return 0;
		178	}
1702	cejka	179
		180	/** @}
		181	*/
		182

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/security/cap.c/ – Rev 1839