xref: /linux/security/apparmor/include/file.h (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 
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  * The xindex is broken into 3 parts
50  * - index - an index into either the exec name table or the variable table
51  * - exec type - which determines how the executable name and index are used
52  * - flags - which modify how the destination name is applied
53  */
54 #define AA_X_INDEX_MASK		AA_INDEX_MASK
55 
56 #define AA_X_TYPE_MASK		0x0c000000
57 #define AA_X_NONE		AA_INDEX_NONE
58 #define AA_X_NAME		0x04000000 /* use executable name px */
59 #define AA_X_TABLE		0x08000000 /* use a specified name ->n# */
60 
61 #define AA_X_UNSAFE		0x10000000
62 #define AA_X_CHILD		0x20000000
63 #define AA_X_INHERIT		0x40000000
64 #define AA_X_UNCONFINED		0x80000000
65 
66 /* need to make conditional which ones are being set */
67 struct path_cond {
68 	kuid_t uid;
69 	umode_t mode;
70 };
71 
72 #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
73 
74 int aa_audit_file(const struct cred *cred,
75 		  struct aa_profile *profile, struct aa_perms *perms,
76 		  const char *op, u32 request, const char *name,
77 		  const char *target, struct aa_label *tlabel, kuid_t ouid,
78 		  const char *info, int error);
79 
80 struct aa_perms *aa_lookup_fperms(struct aa_policydb *file_rules,
81 				  aa_state_t state, struct path_cond *cond);
82 aa_state_t aa_str_perms(struct aa_policydb *file_rules, aa_state_t start,
83 			const char *name, struct path_cond *cond,
84 			struct aa_perms *perms);
85 
86 int aa_path_perm(const char *op, const struct cred *subj_cred,
87 		 struct aa_label *label, const struct path *path,
88 		 int flags, u32 request, struct path_cond *cond);
89 
90 int aa_path_link(const struct cred *subj_cred, struct aa_label *label,
91 		 struct dentry *old_dentry, const struct path *new_dir,
92 		 struct dentry *new_dentry);
93 
94 int aa_file_perm(const char *op, const struct cred *subj_cred,
95 		 struct aa_label *label, struct file *file,
96 		 u32 request, bool in_atomic);
97 
98 void aa_inherit_files(const struct cred *cred, struct files_struct *files);
99 
100 
101 /**
102  * aa_map_file_perms - map file flags to AppArmor permissions
103  * @file: open file to map flags to AppArmor permissions
104  *
105  * Returns: apparmor permission set for the file
106  */
107 static inline u32 aa_map_file_to_perms(struct file *file)
108 {
109 	int flags = file->f_flags;
110 	u32 perms = 0;
111 
112 	if (file->f_mode & FMODE_WRITE)
113 		perms |= MAY_WRITE;
114 	if (file->f_mode & FMODE_READ)
115 		perms |= MAY_READ;
116 
117 	if ((flags & O_APPEND) && (perms & MAY_WRITE))
118 		perms = (perms & ~MAY_WRITE) | MAY_APPEND;
119 	/* trunc implies write permission */
120 	if (flags & O_TRUNC)
121 		perms |= MAY_WRITE;
122 	if (flags & O_CREAT)
123 		perms |= AA_MAY_CREATE;
124 
125 	return perms;
126 }
127 
128 #endif /* __AA_FILE_H */
129