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