1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor policy definitions.
5  *
6  * Copyright (C) 1998-2008 Novell/SUSE
7  * Copyright 2009-2017 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_NAMESPACE_H
16 #define __AA_NAMESPACE_H
17 
18 #include <linux/kref.h>
19 
20 #include "apparmor.h"
21 #include "apparmorfs.h"
22 #include "label.h"
23 #include "policy.h"
24 
25 
26 /* struct aa_ns_acct - accounting of profiles in namespace
27  * @max_size: maximum space allowed for all profiles in namespace
28  * @max_count: maximum number of profiles that can be in this namespace
29  * @size: current size of profiles
30  * @count: current count of profiles (includes null profiles)
31  */
32 struct aa_ns_acct {
33 	int max_size;
34 	int max_count;
35 	int size;
36 	int count;
37 };
38 
39 /* struct aa_ns - namespace for a set of profiles
40  * @base: common policy
41  * @parent: parent of namespace
42  * @lock: lock for modifying the object
43  * @acct: accounting for the namespace
44  * @unconfined: special unconfined profile for the namespace
45  * @sub_ns: list of namespaces under the current namespace.
46  * @uniq_null: uniq value used for null learning profiles
47  * @uniq_id: a unique id count for the profiles in the namespace
48  * @level: level of ns within the tree hierarchy
49  * @dents: dentries for the namespaces file entries in apparmorfs
50  *
51  * An aa_ns defines the set profiles that are searched to determine which
52  * profile to attach to a task.  Profiles can not be shared between aa_ns
53  * and profile names within a namespace are guaranteed to be unique.  When
54  * profiles in separate namespaces have the same name they are NOT considered
55  * to be equivalent.
56  *
57  * Namespaces are hierarchical and only namespaces and profiles below the
58  * current namespace are visible.
59  *
60  * Namespace names must be unique and can not contain the characters :/\0
61  */
62 struct aa_ns {
63 	struct aa_policy base;
64 	struct aa_ns *parent;
65 	struct mutex lock;
66 	struct aa_ns_acct acct;
67 	struct aa_profile *unconfined;
68 	struct list_head sub_ns;
69 	atomic_t uniq_null;
70 	long uniq_id;
71 	int level;
72 	long revision;
73 	wait_queue_head_t wait;
74 
75 	struct aa_labelset labels;
76 	struct list_head rawdata_list;
77 
78 	struct dentry *dents[AAFS_NS_SIZEOF];
79 };
80 
81 extern struct aa_ns *root_ns;
82 
83 extern const char *aa_hidden_ns_name;
84 
85 #define ns_unconfined(NS) (&(NS)->unconfined->label)
86 
87 bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns);
88 const char *aa_ns_name(struct aa_ns *parent, struct aa_ns *child, bool subns);
89 void aa_free_ns(struct aa_ns *ns);
90 int aa_alloc_root_ns(void);
91 void aa_free_root_ns(void);
92 void aa_free_ns_kref(struct kref *kref);
93 
94 struct aa_ns *aa_find_ns(struct aa_ns *root, const char *name);
95 struct aa_ns *aa_findn_ns(struct aa_ns *root, const char *name, size_t n);
96 struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n);
97 struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n);
98 struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
99 				     struct dentry *dir);
100 struct aa_ns *aa_prepare_ns(struct aa_ns *root, const char *name);
101 void __aa_remove_ns(struct aa_ns *ns);
102 
103 static inline struct aa_profile *aa_deref_parent(struct aa_profile *p)
104 {
105 	return rcu_dereference_protected(p->parent,
106 					 mutex_is_locked(&p->ns->lock));
107 }
108 
109 /**
110  * aa_get_ns - increment references count on @ns
111  * @ns: namespace to increment reference count of (MAYBE NULL)
112  *
113  * Returns: pointer to @ns, if @ns is NULL returns NULL
114  * Requires: @ns must be held with valid refcount when called
115  */
116 static inline struct aa_ns *aa_get_ns(struct aa_ns *ns)
117 {
118 	if (ns)
119 		aa_get_profile(ns->unconfined);
120 
121 	return ns;
122 }
123 
124 /**
125  * aa_put_ns - decrement refcount on @ns
126  * @ns: namespace to put reference of
127  *
128  * Decrement reference count of @ns and if no longer in use free it
129  */
130 static inline void aa_put_ns(struct aa_ns *ns)
131 {
132 	if (ns)
133 		aa_put_profile(ns->unconfined);
134 }
135 
136 /**
137  * __aa_findn_ns - find a namespace on a list by @name
138  * @head: list to search for namespace on  (NOT NULL)
139  * @name: name of namespace to look for  (NOT NULL)
140  * @n: length of @name
141  * Returns: unrefcounted namespace
142  *
143  * Requires: rcu_read_lock be held
144  */
145 static inline struct aa_ns *__aa_findn_ns(struct list_head *head,
146 					  const char *name, size_t n)
147 {
148 	return (struct aa_ns *)__policy_strn_find(head, name, n);
149 }
150 
151 static inline struct aa_ns *__aa_find_ns(struct list_head *head,
152 					 const char *name)
153 {
154 	return __aa_findn_ns(head, name, strlen(name));
155 }
156 
157 static inline struct aa_ns *__aa_lookup_ns(struct aa_ns *base,
158 					   const char *hname)
159 {
160 	return __aa_lookupn_ns(base, hname, strlen(hname));
161 }
162 
163 static inline struct aa_ns *aa_lookup_ns(struct aa_ns *view, const char *name)
164 {
165 	return aa_lookupn_ns(view, name, strlen(name));
166 }
167 
168 #endif /* AA_NAMESPACE_H */
169