1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor policy loading interface function definitions.
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2010 Canonical Ltd.
9  */
10 
11 #ifndef __POLICY_INTERFACE_H
12 #define __POLICY_INTERFACE_H
13 
14 #include <linux/list.h>
15 #include <linux/kref.h>
16 #include <linux/dcache.h>
17 #include <linux/workqueue.h>
18 
19 struct aa_load_ent {
20 	struct list_head list;
21 	struct aa_profile *new;
22 	struct aa_profile *old;
23 	struct aa_profile *rename;
24 	const char *ns_name;
25 };
26 
27 void aa_load_ent_free(struct aa_load_ent *ent);
28 struct aa_load_ent *aa_load_ent_alloc(void);
29 
30 #define PACKED_FLAG_HAT		1
31 
32 #define PACKED_MODE_ENFORCE	0
33 #define PACKED_MODE_COMPLAIN	1
34 #define PACKED_MODE_KILL	2
35 #define PACKED_MODE_UNCONFINED	3
36 
37 struct aa_ns;
38 
39 enum {
40 	AAFS_LOADDATA_ABI = 0,
41 	AAFS_LOADDATA_REVISION,
42 	AAFS_LOADDATA_HASH,
43 	AAFS_LOADDATA_DATA,
44 	AAFS_LOADDATA_COMPRESSED_SIZE,
45 	AAFS_LOADDATA_DIR,		/* must be last actual entry */
46 	AAFS_LOADDATA_NDENTS		/* count of entries */
47 };
48 
49 /*
50  * struct aa_loaddata - buffer of policy raw_data set
51  *
52  * there is no loaddata ref for being on ns list, nor a ref from
53  * d_inode(@dentry) when grab a ref from these, @ns->lock must be held
54  * && __aa_get_loaddata() needs to be used, and the return value
55  * checked, if NULL the loaddata is already being reaped and should be
56  * considered dead.
57  */
58 struct aa_loaddata {
59 	struct kref count;
60 	struct list_head list;
61 	struct work_struct work;
62 	struct dentry *dents[AAFS_LOADDATA_NDENTS];
63 	struct aa_ns *ns;
64 	char *name;
65 	size_t size;			/* the original size of the payload */
66 	size_t compressed_size;		/* the compressed size of the payload */
67 	long revision;			/* the ns policy revision this caused */
68 	int abi;
69 	unsigned char *hash;
70 
71 	/* Pointer to payload. If @compressed_size > 0, then this is the
72 	 * compressed version of the payload, else it is the uncompressed
73 	 * version (with the size indicated by @size).
74 	 */
75 	char *data;
76 };
77 
78 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, const char **ns);
79 
80 /**
81  * __aa_get_loaddata - get a reference count to uncounted data reference
82  * @data: reference to get a count on
83  *
84  * Returns: pointer to reference OR NULL if race is lost and reference is
85  *          being repeated.
86  * Requires: @data->ns->lock held, and the return code MUST be checked
87  *
88  * Use only from inode->i_private and @data->list found references
89  */
90 static inline struct aa_loaddata *
91 __aa_get_loaddata(struct aa_loaddata *data)
92 {
93 	if (data && kref_get_unless_zero(&(data->count)))
94 		return data;
95 
96 	return NULL;
97 }
98 
99 /**
100  * aa_get_loaddata - get a reference count from a counted data reference
101  * @data: reference to get a count on
102  *
103  * Returns: point to reference
104  * Requires: @data to have a valid reference count on it. It is a bug
105  *           if the race to reap can be encountered when it is used.
106  */
107 static inline struct aa_loaddata *
108 aa_get_loaddata(struct aa_loaddata *data)
109 {
110 	struct aa_loaddata *tmp = __aa_get_loaddata(data);
111 
112 	AA_BUG(data && !tmp);
113 
114 	return tmp;
115 }
116 
117 void __aa_loaddata_update(struct aa_loaddata *data, long revision);
118 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r);
119 void aa_loaddata_kref(struct kref *kref);
120 struct aa_loaddata *aa_loaddata_alloc(size_t size);
121 static inline void aa_put_loaddata(struct aa_loaddata *data)
122 {
123 	if (data)
124 		kref_put(&data->count, aa_loaddata_kref);
125 }
126 
127 #endif /* __POLICY_INTERFACE_H */
128