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Diffstat (limited to 'security/apparmor/include/cred.h')
-rw-r--r-- | security/apparmor/include/cred.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/security/apparmor/include/cred.h b/security/apparmor/include/cred.h new file mode 100644 index 000000000000..e287b7d0d4be --- /dev/null +++ b/security/apparmor/include/cred.h @@ -0,0 +1,176 @@ +/* + * AppArmor security module + * + * This file contains AppArmor contexts used to associate "labels" to objects. + * + * Copyright (C) 1998-2008 Novell/SUSE + * Copyright 2009-2010 Canonical Ltd. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + */ + +#ifndef __AA_CONTEXT_H +#define __AA_CONTEXT_H + +#include <linux/cred.h> +#include <linux/slab.h> +#include <linux/sched.h> + +#include "label.h" +#include "policy_ns.h" +#include "task.h" + +#define cred_label(X) ((X)->security) + + +/** + * aa_cred_raw_label - obtain cred's label + * @cred: cred to obtain label from (NOT NULL) + * + * Returns: confining label + * + * does NOT increment reference count + */ +static inline struct aa_label *aa_cred_raw_label(const struct cred *cred) +{ + struct aa_label *label = cred_label(cred); + + AA_BUG(!label); + return label; +} + +/** + * aa_get_newest_cred_label - obtain the newest label on a cred + * @cred: cred to obtain label from (NOT NULL) + * + * Returns: newest version of confining label + */ +static inline struct aa_label *aa_get_newest_cred_label(const struct cred *cred) +{ + return aa_get_newest_label(aa_cred_raw_label(cred)); +} + +/** + * __aa_task_raw_label - retrieve another task's label + * @task: task to query (NOT NULL) + * + * Returns: @task's label without incrementing its ref count + * + * If @task != current needs to be called in RCU safe critical section + */ +static inline struct aa_label *__aa_task_raw_label(struct task_struct *task) +{ + return aa_cred_raw_label(__task_cred(task)); +} + +/** + * aa_current_raw_label - find the current tasks confining label + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * This fn will not update the tasks cred to the most up to date version + * of the label so it is safe to call when inside of locks. + */ +static inline struct aa_label *aa_current_raw_label(void) +{ + return aa_cred_raw_label(current_cred()); +} + +/** + * aa_get_current_label - get the newest version of the current tasks label + * + * Returns: newest version of confining label (NOT NULL) + * + * This fn will not update the tasks cred, so it is safe inside of locks + * + * The returned reference must be put with aa_put_label() + */ +static inline struct aa_label *aa_get_current_label(void) +{ + struct aa_label *l = aa_current_raw_label(); + + if (label_is_stale(l)) + return aa_get_newest_label(l); + return aa_get_label(l); +} + +#define __end_current_label_crit_section(X) end_current_label_crit_section(X) + +/** + * end_label_crit_section - put a reference found with begin_current_label.. + * @label: label reference to put + * + * Should only be used with a reference obtained with + * begin_current_label_crit_section and never used in situations where the + * task cred may be updated + */ +static inline void end_current_label_crit_section(struct aa_label *label) +{ + if (label != aa_current_raw_label()) + aa_put_label(label); +} + +/** + * __begin_current_label_crit_section - current's confining label + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * safe to call inside locks + * + * The returned reference must be put with __end_current_label_crit_section() + * This must NOT be used if the task cred could be updated within the + * critical section between __begin_current_label_crit_section() .. + * __end_current_label_crit_section() + */ +static inline struct aa_label *__begin_current_label_crit_section(void) +{ + struct aa_label *label = aa_current_raw_label(); + + if (label_is_stale(label)) + label = aa_get_newest_label(label); + + return label; +} + +/** + * begin_current_label_crit_section - current's confining label and update it + * + * Returns: up to date confining label or the ns unconfined label (NOT NULL) + * + * Not safe to call inside locks + * + * The returned reference must be put with end_current_label_crit_section() + * This must NOT be used if the task cred could be updated within the + * critical section between begin_current_label_crit_section() .. + * end_current_label_crit_section() + */ +static inline struct aa_label *begin_current_label_crit_section(void) +{ + struct aa_label *label = aa_current_raw_label(); + + if (label_is_stale(label)) { + label = aa_get_newest_label(label); + if (aa_replace_current_label(label) == 0) + /* task cred will keep the reference */ + aa_put_label(label); + } + + return label; +} + +static inline struct aa_ns *aa_get_current_ns(void) +{ + struct aa_label *label; + struct aa_ns *ns; + + label = __begin_current_label_crit_section(); + ns = aa_get_ns(labels_ns(label)); + __end_current_label_crit_section(label); + + return ns; +} + +#endif /* __AA_CONTEXT_H */ |