1/*
 2 * AppArmor security module
 3 *
 4 * This file contains AppArmor task related definitions and mediation
 5 *
 6 * Copyright 2017 Canonical Ltd.
 7 *
 8 * This program is free software; you can redistribute it and/or
 9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation, version 2 of the
11 * License.
12 */
13
14#ifndef __AA_TASK_H
15#define __AA_TASK_H
16
17#define task_ctx(X) ((X)->security)
18
19/*
20 * struct aa_task_ctx - information for current task label change
21 * @nnp: snapshot of label at time of no_new_privs
22 * @onexec: profile to transition to on next exec  (MAY BE NULL)
23 * @previous: profile the task may return to     (MAY BE NULL)
24 * @token: magic value the task must know for returning to @previous_profile
25 */
26struct aa_task_ctx {
27	struct aa_label *nnp;
28	struct aa_label *onexec;
29	struct aa_label *previous;
30	u64 token;
31};
32
33int aa_replace_current_label(struct aa_label *label);
34int aa_set_current_onexec(struct aa_label *label, bool stack);
35int aa_set_current_hat(struct aa_label *label, u64 token);
36int aa_restore_previous_label(u64 cookie);
37struct aa_label *aa_get_task_label(struct task_struct *task);
38
39/**
40 * aa_alloc_task_ctx - allocate a new task_ctx
41 * @flags: gfp flags for allocation
42 *
43 * Returns: allocated buffer or NULL on failure
44 */
45static inline struct aa_task_ctx *aa_alloc_task_ctx(gfp_t flags)
46{
47	return kzalloc(sizeof(struct aa_task_ctx), flags);
48}
49
50/**
51 * aa_free_task_ctx - free a task_ctx
52 * @ctx: task_ctx to free (MAYBE NULL)
53 */
54static inline void aa_free_task_ctx(struct aa_task_ctx *ctx)
55{
56	if (ctx) {
57		aa_put_label(ctx->nnp);
58		aa_put_label(ctx->previous);
59		aa_put_label(ctx->onexec);
60
61		kzfree(ctx);
62	}
63}
64
65/**
66 * aa_dup_task_ctx - duplicate a task context, incrementing reference counts
67 * @new: a blank task context      (NOT NULL)
68 * @old: the task context to copy  (NOT NULL)
69 */
70static inline void aa_dup_task_ctx(struct aa_task_ctx *new,
71				   const struct aa_task_ctx *old)
72{
73	*new = *old;
74	aa_get_label(new->nnp);
75	aa_get_label(new->previous);
76	aa_get_label(new->onexec);
77}
78
79/**
80 * aa_clear_task_ctx_trans - clear transition tracking info from the ctx
81 * @ctx: task context to clear (NOT NULL)
82 */
83static inline void aa_clear_task_ctx_trans(struct aa_task_ctx *ctx)
84{
85	AA_BUG(!ctx);
86
87	aa_put_label(ctx->previous);
88	aa_put_label(ctx->onexec);
89	ctx->previous = NULL;
90	ctx->onexec = NULL;
91	ctx->token = 0;
92}
93
94#endif /* __AA_TASK_H */