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c75afcd1 JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor contexts used to associate "labels" to objects. | |
5 | * | |
6 | * Copyright (C) 1998-2008 Novell/SUSE | |
7 | * Copyright 2009-2010 Canonical Ltd. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License as | |
11 | * published by the Free Software Foundation, version 2 of the | |
12 | * License. | |
13 | */ | |
14 | ||
15 | #ifndef __AA_CONTEXT_H | |
16 | #define __AA_CONTEXT_H | |
17 | ||
18 | #include <linux/cred.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/sched.h> | |
21 | ||
22 | #include "policy.h" | |
2bd8dbbf | 23 | #include "policy_ns.h" |
c75afcd1 | 24 | |
55a26ebf JJ |
25 | #define cred_ctx(X) ((X)->security) |
26 | #define current_ctx() cred_ctx(current_cred()) | |
214beaca | 27 | |
c75afcd1 | 28 | /** |
55a26ebf | 29 | * struct aa_task_ctx - primary label for confined tasks |
c75afcd1 JJ |
30 | * @profile: the current profile (NOT NULL) |
31 | * @exec: profile to transition to on next exec (MAYBE NULL) | |
32 | * @previous: profile the task may return to (MAYBE NULL) | |
33 | * @token: magic value the task must know for returning to @previous_profile | |
34 | * | |
35 | * Contains the task's current profile (which could change due to | |
36 | * change_hat). Plus the hat_magic needed during change_hat. | |
37 | * | |
38 | * TODO: make so a task can be confined by a stack of contexts | |
39 | */ | |
55a26ebf | 40 | struct aa_task_ctx { |
c75afcd1 JJ |
41 | struct aa_profile *profile; |
42 | struct aa_profile *onexec; | |
43 | struct aa_profile *previous; | |
44 | u64 token; | |
45 | }; | |
46 | ||
55a26ebf JJ |
47 | struct aa_task_ctx *aa_alloc_task_context(gfp_t flags); |
48 | void aa_free_task_context(struct aa_task_ctx *ctx); | |
49 | void aa_dup_task_context(struct aa_task_ctx *new, | |
50 | const struct aa_task_ctx *old); | |
c75afcd1 JJ |
51 | int aa_replace_current_profile(struct aa_profile *profile); |
52 | int aa_set_current_onexec(struct aa_profile *profile); | |
53 | int aa_set_current_hat(struct aa_profile *profile, u64 token); | |
54 | int aa_restore_previous_profile(u64 cookie); | |
3cfcc19e | 55 | struct aa_profile *aa_get_task_profile(struct task_struct *task); |
c75afcd1 | 56 | |
c75afcd1 JJ |
57 | |
58 | /** | |
cf797c0e | 59 | * aa_cred_raw_profile - obtain cred's profiles |
c75afcd1 JJ |
60 | * @cred: cred to obtain profiles from (NOT NULL) |
61 | * | |
62 | * Returns: confining profile | |
63 | * | |
64 | * does NOT increment reference count | |
65 | */ | |
cf797c0e | 66 | static inline struct aa_profile *aa_cred_raw_profile(const struct cred *cred) |
c75afcd1 | 67 | { |
55a26ebf JJ |
68 | struct aa_task_ctx *ctx = cred_ctx(cred); |
69 | ||
70 | AA_BUG(!ctx || !ctx->profile); | |
71 | return ctx->profile; | |
c75afcd1 JJ |
72 | } |
73 | ||
3cfcc19e | 74 | /** |
cf797c0e JJ |
75 | * aa_get_newest_cred_profile - obtain the newest profile on a cred |
76 | * @cred: cred to obtain profile from (NOT NULL) | |
77 | * | |
78 | * Returns: newest version of confining profile | |
79 | */ | |
80 | static inline | |
81 | struct aa_profile *aa_get_newest_cred_profile(const struct cred *cred) | |
82 | { | |
83 | return aa_get_newest_profile(aa_cred_raw_profile(cred)); | |
84 | } | |
85 | ||
86 | /** | |
87 | * __aa_task_raw_profile - retrieve another task's profile | |
3cfcc19e JJ |
88 | * @task: task to query (NOT NULL) |
89 | * | |
90 | * Returns: @task's profile without incrementing its ref count | |
91 | * | |
92 | * If @task != current needs to be called in RCU safe critical section | |
93 | */ | |
cf797c0e | 94 | static inline struct aa_profile *__aa_task_raw_profile(struct task_struct *task) |
3cfcc19e | 95 | { |
cf797c0e | 96 | return aa_cred_raw_profile(__task_cred(task)); |
3cfcc19e JJ |
97 | } |
98 | ||
99 | /** | |
100 | * __aa_task_is_confined - determine if @task has any confinement | |
101 | * @task: task to check confinement of (NOT NULL) | |
102 | * | |
103 | * If @task != current needs to be called in RCU safe critical section | |
104 | */ | |
105 | static inline bool __aa_task_is_confined(struct task_struct *task) | |
106 | { | |
cf797c0e | 107 | return !unconfined(__aa_task_raw_profile(task)); |
3cfcc19e JJ |
108 | } |
109 | ||
c75afcd1 | 110 | /** |
cf797c0e | 111 | * aa_current_raw_profile - find the current tasks confining profile |
c75afcd1 JJ |
112 | * |
113 | * Returns: up to date confining profile or the ns unconfined profile (NOT NULL) | |
114 | * | |
115 | * This fn will not update the tasks cred to the most up to date version | |
116 | * of the profile so it is safe to call when inside of locks. | |
117 | */ | |
cf797c0e | 118 | static inline struct aa_profile *aa_current_raw_profile(void) |
c75afcd1 | 119 | { |
cf797c0e | 120 | return aa_cred_raw_profile(current_cred()); |
c75afcd1 JJ |
121 | } |
122 | ||
123 | /** | |
cf797c0e | 124 | * aa_get_current_profile - get the newest version of the current tasks profile |
c75afcd1 | 125 | * |
cf797c0e JJ |
126 | * Returns: newest version of confining profile (NOT NULL) |
127 | * | |
128 | * This fn will not update the tasks cred, so it is safe inside of locks | |
c75afcd1 | 129 | * |
cf797c0e | 130 | * The returned reference must be put with aa_put_profile() |
c75afcd1 | 131 | */ |
cf797c0e | 132 | static inline struct aa_profile *aa_get_current_profile(void) |
c75afcd1 | 133 | { |
cf797c0e | 134 | struct aa_profile *p = aa_current_raw_profile(); |
c75afcd1 | 135 | |
cf797c0e JJ |
136 | if (profile_is_stale(p)) |
137 | return aa_get_newest_profile(p); | |
138 | return aa_get_profile(p); | |
139 | } | |
55a26ebf | 140 | |
cf797c0e JJ |
141 | #define __end_current_profile_crit_section(X) \ |
142 | end_current_profile_crit_section(X) | |
143 | ||
144 | /** | |
145 | * end_profile_crit_section - put a reference found with begin_current_profile.. | |
146 | * @profile: profile reference to put | |
147 | * | |
148 | * Should only be used with a reference obtained with | |
149 | * begin_current_profile_crit_section and never used in situations where the | |
150 | * task cred may be updated | |
151 | */ | |
152 | static inline void end_current_profile_crit_section(struct aa_profile *profile) | |
153 | { | |
154 | if (profile != aa_current_raw_profile()) | |
77b071b3 | 155 | aa_put_profile(profile); |
cf797c0e JJ |
156 | } |
157 | ||
158 | /** | |
159 | * __begin_current_profile_crit_section - current's confining profile | |
160 | * | |
161 | * Returns: up to date confining profile or the ns unconfined profile (NOT NULL) | |
162 | * | |
163 | * safe to call inside locks | |
164 | * | |
165 | * The returned reference must be put with __end_current_profile_crit_section() | |
166 | * This must NOT be used if the task cred could be updated within the | |
167 | * critical section between __begin_current_profile_crit_section() .. | |
168 | * __end_current_profile_crit_section() | |
169 | */ | |
170 | static inline struct aa_profile *__begin_current_profile_crit_section(void) | |
171 | { | |
172 | struct aa_profile *profile = aa_current_raw_profile(); | |
173 | ||
174 | if (profile_is_stale(profile)) | |
175 | profile = aa_get_newest_profile(profile); | |
176 | ||
177 | return profile; | |
178 | } | |
179 | ||
180 | /** | |
181 | * begin_current_profile_crit_section - current's profile and update if needed | |
182 | * | |
183 | * Returns: up to date confining profile or the ns unconfined profile (NOT NULL) | |
184 | * | |
185 | * Not safe to call inside locks | |
186 | * | |
187 | * The returned reference must be put with end_current_profile_crit_section() | |
188 | * This must NOT be used if the task cred could be updated within the | |
189 | * critical section between begin_current_profile_crit_section() .. | |
190 | * end_current_profile_crit_section() | |
191 | */ | |
192 | static inline struct aa_profile *begin_current_profile_crit_section(void) | |
193 | { | |
194 | struct aa_profile *profile = aa_current_raw_profile(); | |
195 | ||
196 | if (profile_is_stale(profile)) { | |
197 | profile = aa_get_newest_profile(profile); | |
198 | if (aa_replace_current_profile(profile) == 0) | |
199 | /* task cred will keep the reference */ | |
200 | aa_put_profile(profile); | |
77b071b3 | 201 | } |
c75afcd1 | 202 | |
cf797c0e | 203 | return profile; |
c75afcd1 JJ |
204 | } |
205 | ||
2bd8dbbf JJ |
206 | static inline struct aa_ns *aa_get_current_ns(void) |
207 | { | |
cf797c0e JJ |
208 | struct aa_profile *profile; |
209 | struct aa_ns *ns; | |
210 | ||
211 | profile = __begin_current_profile_crit_section(); | |
212 | ns = aa_get_ns(profile->ns); | |
213 | __end_current_profile_crit_section(profile); | |
214 | ||
215 | return ns; | |
2bd8dbbf JJ |
216 | } |
217 | ||
7a2871b5 | 218 | /** |
55a26ebf JJ |
219 | * aa_clear_task_ctx_trans - clear transition tracking info from the ctx |
220 | * @ctx: task context to clear (NOT NULL) | |
7a2871b5 | 221 | */ |
55a26ebf | 222 | static inline void aa_clear_task_ctx_trans(struct aa_task_ctx *ctx) |
7a2871b5 | 223 | { |
55a26ebf JJ |
224 | aa_put_profile(ctx->previous); |
225 | aa_put_profile(ctx->onexec); | |
226 | ctx->previous = NULL; | |
227 | ctx->onexec = NULL; | |
228 | ctx->token = 0; | |
7a2871b5 JJ |
229 | } |
230 | ||
c75afcd1 | 231 | #endif /* __AA_CONTEXT_H */ |