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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* AppArmor security module
*
* This file contains AppArmor file mediation function definitions.
*
* 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_FILE_H
#define __AA_FILE_H
#include <linux/spinlock.h>
#include "domain.h"
#include "match.h"
#include "perms.h"
struct aa_profile;
struct path;
#define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND))
#define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\
AA_MAY_CREATE | AA_MAY_DELETE | \
AA_MAY_GETATTR | AA_MAY_SETATTR | \
AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \
AA_EXEC_MMAP | AA_MAY_LINK)
#define file_ctx(X) ((struct aa_file_ctx *)(X)->f_security)
/* struct aa_file_ctx - the AppArmor context the file was opened in
* @lock: lock to update the ctx
* @label: label currently cached on the ctx
* @perms: the permission the file was opened with
*/
struct aa_file_ctx {
spinlock_t lock;
struct aa_label __rcu *label;
u32 allow;
};
/**
* aa_alloc_file_ctx - allocate file_ctx
* @label: initial label of task creating the file
* @gfp: gfp flags for allocation
*
* Returns: file_ctx or NULL on failure
*/
static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label,
gfp_t gfp)
{
struct aa_file_ctx *ctx;
ctx = kzalloc(sizeof(struct aa_file_ctx), gfp);
if (ctx) {
spin_lock_init(&ctx->lock);
rcu_assign_pointer(ctx->label, aa_get_label(label));
}
return ctx;
}
/**
* aa_free_file_ctx - free a file_ctx
* @ctx: file_ctx to free (MAYBE_NULL)
*/
static inline void aa_free_file_ctx(struct aa_file_ctx *ctx)
{
if (ctx) {
aa_put_label(rcu_access_pointer(ctx->label));
kzfree(ctx);
}
}
static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx)
{
return aa_get_label_rcu(&ctx->label);
}
/*
* The xindex is broken into 3 parts
* - index - an index into either the exec name table or the variable table
* - exec type - which determines how the executable name and index are used
* - flags - which modify how the destination name is applied
*/
#define AA_X_INDEX_MASK 0x03ff
#define AA_X_TYPE_MASK 0x0c00
#define AA_X_TYPE_SHIFT 10
#define AA_X_NONE 0x0000
#define AA_X_NAME 0x0400 /* use executable name px */
#define AA_X_TABLE 0x0800 /* use a specified name ->n# */
#define AA_X_UNSAFE 0x1000
#define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */
#define AA_X_INHERIT 0x4000
#define AA_X_UNCONFINED 0x8000
/* need to make conditional which ones are being set */
struct path_cond {
kuid_t uid;
umode_t mode;
};
#define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
/* FIXME: split perms from dfa and match this to description
* also add delegation info.
*/
static inline u16 dfa_map_xindex(u16 mask)
{
u16 old_index = (mask >> 10) & 0xf;
u16 index = 0;
if (mask & 0x100)
index |= AA_X_UNSAFE;
if (mask & 0x200)
index |= AA_X_INHERIT;
if (mask & 0x80)
index |= AA_X_UNCONFINED;
if (old_index == 1) {
index |= AA_X_UNCONFINED;
} else if (old_index == 2) {
index |= AA_X_NAME;
} else if (old_index == 3) {
index |= AA_X_NAME | AA_X_CHILD;
} else if (old_index) {
index |= AA_X_TABLE;
index |= old_index - 4;
}
return index;
}
/*
* map old dfa inline permissions to new format
*/
#define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \
((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
#define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f)
#define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f)
#define dfa_user_xindex(dfa, state) \
(dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff))
#define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \
0x7f) | \
((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
#define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f)
#define dfa_other_quiet(dfa, state) \
((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f)
#define dfa_other_xindex(dfa, state) \
dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff)
int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms,
const char *op, u32 request, const char *name,
const char *target, struct aa_label *tlabel, kuid_t ouid,
const char *info, int error);
/**
* struct aa_file_rules - components used for file rule permissions
* @dfa: dfa to match path names and conditionals against
* @perms: permission table indexed by the matched state accept entry of @dfa
* @trans: transition table for indexed by named x transitions
*
* File permission are determined by matching a path against @dfa and then
* then using the value of the accept entry for the matching state as
* an index into @perms. If a named exec transition is required it is
* looked up in the transition table.
*/
struct aa_file_rules {
unsigned int start;
struct aa_dfa *dfa;
/* struct perms perms; */
struct aa_domain trans;
/* TODO: add delegate table */
};
struct aa_perms aa_compute_fperms(struct aa_dfa *dfa, unsigned int state,
struct path_cond *cond);
unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start,
const char *name, struct path_cond *cond,
struct aa_perms *perms);
int __aa_path_perm(const char *op, struct aa_profile *profile,
const char *name, u32 request, struct path_cond *cond,
int flags, struct aa_perms *perms);
int aa_path_perm(const char *op, struct aa_label *label,
const struct path *path, int flags, u32 request,
struct path_cond *cond);
int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
const struct path *new_dir, struct dentry *new_dentry);
int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
u32 request);
void aa_inherit_files(const struct cred *cred, struct files_struct *files);
static inline void aa_free_file_rules(struct aa_file_rules *rules)
{
aa_put_dfa(rules->dfa);
aa_free_domain_entries(&rules->trans);
}
/**
* aa_map_file_perms - map file flags to AppArmor permissions
* @file: open file to map flags to AppArmor permissions
*
* Returns: apparmor permission set for the file
*/
static inline u32 aa_map_file_to_perms(struct file *file)
{
int flags = file->f_flags;
u32 perms = 0;
if (file->f_mode & FMODE_WRITE)
perms |= MAY_WRITE;
if (file->f_mode & FMODE_READ)
perms |= MAY_READ;
if ((flags & O_APPEND) && (perms & MAY_WRITE))
perms = (perms & ~MAY_WRITE) | MAY_APPEND;
/* trunc implies write permission */
if (flags & O_TRUNC)
perms |= MAY_WRITE;
if (flags & O_CREAT)
perms |= AA_MAY_CREATE;
return perms;
}
#endif /* __AA_FILE_H */
|
