Subversion Repositories HelenOS

Rev

Rev 3343 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1174 jermar 1 
/*
2071 jermar 2 
 * Copyright (c) 2006 Jakub Jermar
1174 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 
 
1888 jermar 29 
/** @addtogroup generic
1702 cejka 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>
3862 rimsky 46 
#include <arch/asm.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 
 
1888 jermar 180 
/** @}
1702 cejka 181 
 */
182