security/apparmor/include/policy_ns.h

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