1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * AppArmor security module
4 *
5 * This file contains AppArmor file mediation function definitions.
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11 #ifndef __AA_FILE_H
12 #define __AA_FILE_H
13
14 #include <linux/spinlock.h>
15
16 #include "domain.h"
17 #include "match.h"
18 #include "perms.h"
19
20 struct aa_policydb;
21 struct aa_profile;
22 struct path;
23
24 #define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND))
25
26 #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\
27 AA_MAY_CREATE | AA_MAY_DELETE | \
28 AA_MAY_GETATTR | AA_MAY_SETATTR | \
29 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \
30 AA_EXEC_MMAP | AA_MAY_LINK)
31
file_ctx(struct file * file)32 static inline struct aa_file_ctx *file_ctx(struct file *file)
33 {
34 return file->f_security + apparmor_blob_sizes.lbs_file;
35 }
36
37 /* struct aa_file_ctx - the AppArmor context the file was opened in
38 * @lock: lock to update the ctx
39 * @label: label currently cached on the ctx
40 * @perms: the permission the file was opened with
41 */
42 struct aa_file_ctx {
43 spinlock_t lock;
44 struct aa_label __rcu *label;
45 u32 allow;
46 };
47
48 /**
49 * aa_alloc_file_ctx - allocate file_ctx
50 * @label: initial label of task creating the file
51 * @gfp: gfp flags for allocation
52 *
53 * Returns: file_ctx or NULL on failure
54 */
aa_alloc_file_ctx(struct aa_label * label,gfp_t gfp)55 static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label,
56 gfp_t gfp)
57 {
58 struct aa_file_ctx *ctx;
59
60 ctx = kzalloc(sizeof(struct aa_file_ctx), gfp);
61 if (ctx) {
62 spin_lock_init(&ctx->lock);
63 rcu_assign_pointer(ctx->label, aa_get_label(label));
64 }
65 return ctx;
66 }
67
68 /**
69 * aa_free_file_ctx - free a file_ctx
70 * @ctx: file_ctx to free (MAYBE_NULL)
71 */
aa_free_file_ctx(struct aa_file_ctx * ctx)72 static inline void aa_free_file_ctx(struct aa_file_ctx *ctx)
73 {
74 if (ctx) {
75 aa_put_label(rcu_access_pointer(ctx->label));
76 kfree_sensitive(ctx);
77 }
78 }
79
aa_get_file_label(struct aa_file_ctx * ctx)80 static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx)
81 {
82 return aa_get_label_rcu(&ctx->label);
83 }
84
85 /*
86 * The xindex is broken into 3 parts
87 * - index - an index into either the exec name table or the variable table
88 * - exec type - which determines how the executable name and index are used
89 * - flags - which modify how the destination name is applied
90 */
91 #define AA_X_INDEX_MASK AA_INDEX_MASK
92
93 #define AA_X_TYPE_MASK 0x0c000000
94 #define AA_X_NONE AA_INDEX_NONE
95 #define AA_X_NAME 0x04000000 /* use executable name px */
96 #define AA_X_TABLE 0x08000000 /* use a specified name ->n# */
97
98 #define AA_X_UNSAFE 0x10000000
99 #define AA_X_CHILD 0x20000000
100 #define AA_X_INHERIT 0x40000000
101 #define AA_X_UNCONFINED 0x80000000
102
103 /* need to make conditional which ones are being set */
104 struct path_cond {
105 kuid_t uid;
106 umode_t mode;
107 };
108
109 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
110
111 int aa_audit_file(const struct cred *cred,
112 struct aa_profile *profile, struct aa_perms *perms,
113 const char *op, u32 request, const char *name,
114 const char *target, struct aa_label *tlabel, kuid_t ouid,
115 const char *info, int error);
116
117 struct aa_perms *aa_lookup_fperms(struct aa_policydb *file_rules,
118 aa_state_t state, struct path_cond *cond);
119 aa_state_t aa_str_perms(struct aa_policydb *file_rules, aa_state_t start,
120 const char *name, struct path_cond *cond,
121 struct aa_perms *perms);
122
123 int aa_path_perm(const char *op, const struct cred *subj_cred,
124 struct aa_label *label, const struct path *path,
125 int flags, u32 request, struct path_cond *cond);
126
127 int aa_path_link(const struct cred *subj_cred, struct aa_label *label,
128 struct dentry *old_dentry, const struct path *new_dir,
129 struct dentry *new_dentry);
130
131 int aa_file_perm(const char *op, const struct cred *subj_cred,
132 struct aa_label *label, struct file *file,
133 u32 request, bool in_atomic);
134
135 void aa_inherit_files(const struct cred *cred, struct files_struct *files);
136
137
138 /**
139 * aa_map_file_perms - map file flags to AppArmor permissions
140 * @file: open file to map flags to AppArmor permissions
141 *
142 * Returns: apparmor permission set for the file
143 */
aa_map_file_to_perms(struct file * file)144 static inline u32 aa_map_file_to_perms(struct file *file)
145 {
146 int flags = file->f_flags;
147 u32 perms = 0;
148
149 if (file->f_mode & FMODE_WRITE)
150 perms |= MAY_WRITE;
151 if (file->f_mode & FMODE_READ)
152 perms |= MAY_READ;
153
154 if ((flags & O_APPEND) && (perms & MAY_WRITE))
155 perms = (perms & ~MAY_WRITE) | MAY_APPEND;
156 /* trunc implies write permission */
157 if (flags & O_TRUNC)
158 perms |= MAY_WRITE;
159 if (flags & O_CREAT)
160 perms |= AA_MAY_CREATE;
161
162 return perms;
163 }
164
165 #endif /* __AA_FILE_H */
166