| /* |
| * 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.h" |
| |
| #define cred_cxt(X) (X)->security |
| #define current_cxt() cred_cxt(current_cred()) |
| #define current_ns() labels_ns(aa_current_raw_label()) |
| |
| /** |
| * struct aa_task_cxt - primary label for confined tasks |
| * @label: the current label (NOT NULL) |
| * @exec: label to transition to on next exec (MAYBE NULL) |
| * @previous: label the task may return to (MAYBE NULL) |
| * @token: magic value the task must know for returning to @previous |
| * |
| * Contains the task's current label (which could change due to |
| * change_hat). Plus the hat_magic needed during change_hat. |
| * |
| * TODO: make so a task can be confined by a stack of contexts |
| */ |
| struct aa_task_cxt { |
| struct aa_label *label; |
| struct aa_label *onexec; |
| struct aa_label *previous; |
| u64 token; |
| }; |
| |
| struct aa_task_cxt *aa_alloc_task_context(gfp_t flags); |
| void aa_free_task_context(struct aa_task_cxt *cxt); |
| void aa_dup_task_context(struct aa_task_cxt *new, |
| const struct aa_task_cxt *old); |
| int aa_replace_current_label(struct aa_label *label); |
| int aa_set_current_onexec(struct aa_label *label); |
| int aa_set_current_hat(struct aa_label *label, u64 token); |
| int aa_restore_previous_label(u64 cookie); |
| struct aa_label *aa_get_task_label(struct task_struct *task); |
| |
| |
| /** |
| * 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_task_cxt *cxt = cred_cxt(cred); |
| BUG_ON(!cxt || !cxt->label); |
| return cxt->label; |
| } |
| |
| /** |
| * aa_get_newest_cred_label - obtain the newest version of the 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_task_is_confined - determine if @task has any confinement |
| * @task: task to check confinement of (NOT NULL) |
| * |
| * If @task != current needs to be called in RCU safe critical section |
| */ |
| static inline bool __aa_task_is_confined(struct task_struct *task) |
| { |
| return !unconfined(__aa_task_raw_label(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_invalid(l)) |
| return aa_get_newest_label(l); |
| return aa_get_label(l); |
| } |
| |
| /** |
| * aa_begin_current_label - find 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_end_current_label() |
| */ |
| static inline struct aa_label *aa_begin_current_label(void) |
| { |
| struct aa_label *l = aa_current_raw_label(); |
| |
| if (label_invalid(l)) |
| l = aa_get_newest_label(l); |
| return l; |
| } |
| |
| /** |
| * aa_end_current_label - put a reference found with aa_begin_current_label |
| * @label: label reference to put |
| * |
| * Should only be used with a reference obtained with aa_begin_current_label |
| * and never used in situations where the task cred may be updated |
| */ |
| static inline void aa_end_current_label(struct aa_label *label) |
| { |
| if (label != aa_current_raw_label()) |
| aa_put_label(label); |
| } |
| |
| /** |
| * aa_current_label - find the current tasks confining label and update it |
| * |
| * Returns: up to date confining label or the ns unconfined label (NOT NULL) |
| * |
| * This fn will update the tasks cred structure if the label has been |
| * replaced. Not safe to call inside locks |
| */ |
| static inline struct aa_label *aa_current_label(void) |
| { |
| const struct aa_task_cxt *cxt = current_cxt(); |
| struct aa_label *label; |
| BUG_ON(!cxt || !cxt->label); |
| |
| if (label_invalid(cxt->label)) { |
| label = aa_get_newest_label(cxt->label); |
| aa_replace_current_label(label); |
| aa_put_label(label); |
| cxt = current_cxt(); |
| } |
| |
| return cxt->label; |
| } |
| |
| /** |
| * aa_clear_task_cxt_trans - clear transition tracking info from the cxt |
| * @cxt: task context to clear (NOT NULL) |
| */ |
| static inline void aa_clear_task_cxt_trans(struct aa_task_cxt *cxt) |
| { |
| aa_put_label(cxt->previous); |
| aa_put_label(cxt->onexec); |
| cxt->previous = NULL; |
| cxt->onexec = NULL; |
| cxt->token = 0; |
| } |
| |
| #endif /* __AA_CONTEXT_H */ |