1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor policy definitions.
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2017 Canonical Ltd.
9  */
10 
11 #ifndef __AA_NAMESPACE_H
12 #define __AA_NAMESPACE_H
13 
14 #include <linux/kref.h>
15 
16 #include "apparmor.h"
17 #include "apparmorfs.h"
18 #include "label.h"
19 #include "policy.h"
20 
21 
22 /* struct aa_ns_acct - accounting of profiles in namespace
23  * @max_size: maximum space allowed for all profiles in namespace
24  * @max_count: maximum number of profiles that can be in this namespace
25  * @size: current size of profiles
26  * @count: current count of profiles (includes null profiles)
27  */
28 struct aa_ns_acct {
29 	int max_size;
30 	int max_count;
31 	int size;
32 	int count;
33 };
34 
35 /* struct aa_ns - namespace for a set of profiles
36  * @base: common policy
37  * @parent: parent of namespace
38  * @lock: lock for modifying the object
39  * @acct: accounting for the namespace
40  * @unconfined: special unconfined profile for the namespace
41  * @sub_ns: list of namespaces under the current namespace.
42  * @uniq_null: uniq value used for null learning profiles
43  * @uniq_id: a unique id count for the profiles in the namespace
44  * @level: level of ns within the tree hierarchy
45  * @dents: dentries for the namespaces file entries in apparmorfs
46  *
47  * An aa_ns defines the set profiles that are searched to determine which
48  * profile to attach to a task.  Profiles can not be shared between aa_ns
49  * and profile names within a namespace are guaranteed to be unique.  When
50  * profiles in separate namespaces have the same name they are NOT considered
51  * to be equivalent.
52  *
53  * Namespaces are hierarchical and only namespaces and profiles below the
54  * current namespace are visible.
55  *
56  * Namespace names must be unique and can not contain the characters :/\0
57  */
58 struct aa_ns {
59 	struct aa_policy base;
60 	struct aa_ns *parent;
61 	struct mutex lock;
62 	struct aa_ns_acct acct;
63 	struct aa_profile *unconfined;
64 	struct list_head sub_ns;
65 	atomic_t uniq_null;
66 	long uniq_id;
67 	int level;
68 	long revision;
69 	wait_queue_head_t wait;
70 
71 	struct aa_labelset labels;
72 	struct list_head rawdata_list;
73 
74 	struct dentry *dents[AAFS_NS_SIZEOF];
75 };
76 
77 extern struct aa_ns *root_ns;
78 
79 extern const char *aa_hidden_ns_name;
80 
81 #define ns_unconfined(NS) (&(NS)->unconfined->label)
82 
83 bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns);
84 const char *aa_ns_name(struct aa_ns *parent, struct aa_ns *child, bool subns);
85 void aa_free_ns(struct aa_ns *ns);
86 int aa_alloc_root_ns(void);
87 void aa_free_root_ns(void);
88 void aa_free_ns_kref(struct kref *kref);
89 
90 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name);
91 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n);
92 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n);
93 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n);
94 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
95 				     struct dentry *dir);
96 struct aa_ns *aa_prepare_ns(struct aa_ns *root, const char *name);
97 void __aa_remove_ns(struct aa_ns *ns);
98 
99 static inline struct aa_profile *aa_deref_parent(struct aa_profile *p)
100 {
101 	return rcu_dereference_protected(p->parent,
102 					 mutex_is_locked(&p->ns->lock));
103 }
104 
105 /**
106  * aa_get_ns - increment references count on @ns
107  * @ns: namespace to increment reference count of (MAYBE NULL)
108  *
109  * Returns: pointer to @ns, if @ns is NULL returns NULL
110  * Requires: @ns must be held with valid refcount when called
111  */
112 static inline struct aa_ns *aa_get_ns(struct aa_ns *ns)
113 {
114 	if (ns)
115 		aa_get_profile(ns->unconfined);
116 
117 	return ns;
118 }
119 
120 /**
121  * aa_put_ns - decrement refcount on @ns
122  * @ns: namespace to put reference of
123  *
124  * Decrement reference count of @ns and if no longer in use free it
125  */
126 static inline void aa_put_ns(struct aa_ns *ns)
127 {
128 	if (ns)
129 		aa_put_profile(ns->unconfined);
130 }
131 
132 /**
133  * __aa_findn_ns - find a namespace on a list by @name
134  * @head: list to search for namespace on  (NOT NULL)
135  * @name: name of namespace to look for  (NOT NULL)
136  * @n: length of @name
137  * Returns: unrefcounted namespace
138  *
139  * Requires: rcu_read_lock be held
140  */
141 static inline struct aa_ns *__aa_findn_ns(struct list_head *head,
142 					  const char *name, size_t n)
143 {
144 	return (struct aa_ns *)__policy_strn_find(head, name, n);
145 }
146 
147 static inline struct aa_ns *__aa_find_ns(struct list_head *head,
148 					 const char *name)
149 {
150 	return __aa_findn_ns(head, name, strlen(name));
151 }
152 
153 static inline struct aa_ns *__aa_lookup_ns(struct aa_ns *base,
154 					   const char *hname)
155 {
156 	return __aa_lookupn_ns(base, hname, strlen(hname));
157 }
158 
159 static inline struct aa_ns *aa_lookup_ns(struct aa_ns *view, const char *name)
160 {
161 	return aa_lookupn_ns(view, name, strlen(name));
162 }
163 
164 #endif /* AA_NAMESPACE_H */
165