tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor file mediation function definitions.
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 */
14
15#ifndef __AA_FILE_H
16#define __AA_FILE_H
17
18#include <linux/path.h>
19
20#include "domain.h"
21#include "match.h"
22
23struct aa_profile;
24
25/*
26 * We use MAY_EXEC, MAY_WRITE, MAY_READ, MAY_APPEND and the following flags
27 * for profile permissions
28 */
29#define AA_MAY_CREATE 0x0010
30#define AA_MAY_DELETE 0x0020
31#define AA_MAY_META_WRITE 0x0040
32#define AA_MAY_META_READ 0x0080
33
34#define AA_MAY_CHMOD 0x0100
35#define AA_MAY_CHOWN 0x0200
36#define AA_MAY_LOCK 0x0400
37#define AA_EXEC_MMAP 0x0800
38
39#define AA_MAY_LINK 0x1000
40#define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */
41#define AA_MAY_ONEXEC 0x40000000 /* exec allows onexec */
42#define AA_MAY_CHANGE_PROFILE 0x80000000
43#define AA_MAY_CHANGEHAT 0x80000000 /* ctrl auditing only */
44
45#define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\
46 AA_MAY_CREATE | AA_MAY_DELETE | \
47 AA_MAY_META_READ | AA_MAY_META_WRITE | \
48 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \
49 AA_EXEC_MMAP | AA_MAY_LINK)
50
51/*
52 * The xindex is broken into 3 parts
53 * - index - an index into either the exec name table or the variable table
54 * - exec type - which determines how the executable name and index are used
55 * - flags - which modify how the destination name is applied
56 */
57#define AA_X_INDEX_MASK 0x03ff
58
59#define AA_X_TYPE_MASK 0x0c00
60#define AA_X_TYPE_SHIFT 10
61#define AA_X_NONE 0x0000
62#define AA_X_NAME 0x0400 /* use executable name px */
63#define AA_X_TABLE 0x0800 /* use a specified name ->n# */
64
65#define AA_X_UNSAFE 0x1000
66#define AA_X_CHILD 0x2000 /* make >AA_X_NONE apply to children */
67#define AA_X_INHERIT 0x4000
68#define AA_X_UNCONFINED 0x8000
69
70/* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */
71#define AA_SECURE_X_NEEDED 0x8000
72
73/* need to make conditional which ones are being set */
74struct path_cond {
75 uid_t uid;
76 umode_t mode;
77};
78
79/* struct file_perms - file permission
80 * @allow: mask of permissions that are allowed
81 * @audit: mask of permissions to force an audit message for
82 * @quiet: mask of permissions to quiet audit messages for
83 * @kill: mask of permissions that when matched will kill the task
84 * @xindex: exec transition index if @allow contains MAY_EXEC
85 *
86 * The @audit and @queit mask should be mutually exclusive.
87 */
88struct file_perms {
89 u32 allow;
90 u32 audit;
91 u32 quiet;
92 u32 kill;
93 u16 xindex;
94};
95
96extern struct file_perms nullperms;
97
98#define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
99
100/* FIXME: split perms from dfa and match this to description
101 * also add delegation info.
102 */
103static inline u16 dfa_map_xindex(u16 mask)
104{
105 u16 old_index = (mask >> 10) & 0xf;
106 u16 index = 0;
107
108 if (mask & 0x100)
109 index |= AA_X_UNSAFE;
110 if (mask & 0x200)
111 index |= AA_X_INHERIT;
112 if (mask & 0x80)
113 index |= AA_X_UNCONFINED;
114
115 if (old_index == 1) {
116 index |= AA_X_UNCONFINED;
117 } else if (old_index == 2) {
118 index |= AA_X_NAME;
119 } else if (old_index == 3) {
120 index |= AA_X_NAME | AA_X_CHILD;
121 } else {
122 index |= AA_X_TABLE;
123 index |= old_index - 4;
124 }
125
126 return index;
127}
128
129/*
130 * map old dfa inline permissions to new format
131 */
132#define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \
133 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
134#define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f)
135#define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f)
136#define dfa_user_xindex(dfa, state) \
137 (dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff))
138
139#define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \
140 0x7f) | \
141 ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
142#define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f)
143#define dfa_other_quiet(dfa, state) \
144 ((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f)
145#define dfa_other_xindex(dfa, state) \
146 dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff)
147
148int aa_audit_file(struct aa_profile *profile, struct file_perms *perms,
149 gfp_t gfp, int op, u32 request, const char *name,
150 const char *target, uid_t ouid, const char *info, int error);
151
152/**
153 * struct aa_file_rules - components used for file rule permissions
154 * @dfa: dfa to match path names and conditionals against
155 * @perms: permission table indexed by the matched state accept entry of @dfa
156 * @trans: transition table for indexed by named x transitions
157 *
158 * File permission are determined by matching a path against @dfa and then
159 * then using the value of the accept entry for the matching state as
160 * an index into @perms. If a named exec transition is required it is
161 * looked up in the transition table.
162 */
163struct aa_file_rules {
164 unsigned int start;
165 struct aa_dfa *dfa;
166 /* struct perms perms; */
167 struct aa_domain trans;
168 /* TODO: add delegate table */
169};
170
171unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start,
172 const char *name, struct path_cond *cond,
173 struct file_perms *perms);
174
175int aa_path_perm(int op, struct aa_profile *profile, struct path *path,
176 int flags, u32 request, struct path_cond *cond);
177
178int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
179 struct path *new_dir, struct dentry *new_dentry);
180
181int aa_file_perm(int op, struct aa_profile *profile, struct file *file,
182 u32 request);
183
184static inline void aa_free_file_rules(struct aa_file_rules *rules)
185{
186 aa_put_dfa(rules->dfa);
187 aa_free_domain_entries(&rules->trans);
188}
189
190#define ACC_FMODE(x) (("\000\004\002\006"[(x)&O_ACCMODE]) | (((x) << 1) & 0x40))
191
192/* from namei.c */
193#define MAP_OPEN_FLAGS(x) ((((x) + 1) & O_ACCMODE) ? (x) + 1 : (x))
194
195/**
196 * aa_map_file_perms - map file flags to AppArmor permissions
197 * @file: open file to map flags to AppArmor permissions
198 *
199 * Returns: apparmor permission set for the file
200 */
201static inline u32 aa_map_file_to_perms(struct file *file)
202{
203 int flags = MAP_OPEN_FLAGS(file->f_flags);
204 u32 perms = ACC_FMODE(file->f_mode);
205
206 if ((flags & O_APPEND) && (perms & MAY_WRITE))
207 perms = (perms & ~MAY_WRITE) | MAY_APPEND;
208 /* trunc implies write permission */
209 if (flags & O_TRUNC)
210 perms |= MAY_WRITE;
211 if (flags & O_CREAT)
212 perms |= AA_MAY_CREATE;
213
214 return perms;
215}
216
217#endif /* __AA_FILE_H */