context.h
4.28 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
* 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 "policy.h"
/* struct aa_file_cxt - the AppArmor context the file was opened in
* @perms: the permission the file was opened with
*
* The file_cxt could currently be directly stored in file->f_security
* as the profile reference is now stored in the f_cred. However the
* cxt struct will expand in the future so we keep the struct.
*/
struct aa_file_cxt {
u16 allow;
};
/**
* aa_alloc_file_context - allocate file_cxt
* @gfp: gfp flags for allocation
*
* Returns: file_cxt or NULL on failure
*/
static inline struct aa_file_cxt *aa_alloc_file_context(gfp_t gfp)
{
return kzalloc(sizeof(struct aa_file_cxt), gfp);
}
/**
* aa_free_file_context - free a file_cxt
* @cxt: file_cxt to free (MAYBE_NULL)
*/
static inline void aa_free_file_context(struct aa_file_cxt *cxt)
{
if (cxt)
kzfree(cxt);
}
/**
* struct aa_task_cxt - primary label for confined tasks
* @profile: the current profile (NOT NULL)
* @exec: profile to transition to on next exec (MAYBE NULL)
* @previous: profile the task may return to (MAYBE NULL)
* @token: magic value the task must know for returning to @previous_profile
*
* Contains the task's current profile (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_profile *profile;
struct aa_profile *onexec;
struct aa_profile *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_profile(struct aa_profile *profile);
int aa_set_current_onexec(struct aa_profile *profile);
int aa_set_current_hat(struct aa_profile *profile, u64 token);
int aa_restore_previous_profile(u64 cookie);
/**
* __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)
{
struct aa_task_cxt *cxt = __task_cred(task)->security;
BUG_ON(!cxt || !cxt->profile);
if (unconfined(aa_newest_version(cxt->profile)))
return 0;
return 1;
}
/**
* aa_cred_profile - obtain cred's profiles
* @cred: cred to obtain profiles from (NOT NULL)
*
* Returns: confining profile
*
* does NOT increment reference count
*/
static inline struct aa_profile *aa_cred_profile(const struct cred *cred)
{
struct aa_task_cxt *cxt = cred->security;
BUG_ON(!cxt || !cxt->profile);
return aa_newest_version(cxt->profile);
}
/**
* __aa_current_profile - find the current tasks confining profile
*
* Returns: up to date confining profile or the ns unconfined profile (NOT NULL)
*
* This fn will not update the tasks cred to the most up to date version
* of the profile so it is safe to call when inside of locks.
*/
static inline struct aa_profile *__aa_current_profile(void)
{
return aa_cred_profile(current_cred());
}
/**
* aa_current_profile - find the current tasks confining profile and do updates
*
* Returns: up to date confining profile or the ns unconfined profile (NOT NULL)
*
* This fn will update the tasks cred structure if the profile has been
* replaced. Not safe to call inside locks
*/
static inline struct aa_profile *aa_current_profile(void)
{
const struct aa_task_cxt *cxt = current_cred()->security;
struct aa_profile *profile;
BUG_ON(!cxt || !cxt->profile);
profile = aa_newest_version(cxt->profile);
/*
* Whether or not replacement succeeds, use newest profile so
* there is no need to update it after replacement.
*/
if (unlikely((cxt->profile != profile)))
aa_replace_current_profile(profile);
return profile;
}
#endif /* __AA_CONTEXT_H */