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 */
 28struct 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 */
 58struct 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
 77extern struct aa_label *kernel_t;
 78extern struct aa_ns *root_ns;
 79
 80extern const char *aa_hidden_ns_name;
 81
 82#define ns_unconfined(NS) (&(NS)->unconfined->label)
 83
 84bool aa_ns_visible(struct aa_ns *curr, struct aa_ns *view, bool subns);
 85const char *aa_ns_name(struct aa_ns *parent, struct aa_ns *child, bool subns);
 86void aa_free_ns(struct aa_ns *ns);
 87int aa_alloc_root_ns(void);
 88void aa_free_root_ns(void);
 89
 90struct aa_ns *__aa_lookupn_ns(struct aa_ns *view, const char *hname, size_t n);
 91struct aa_ns *aa_lookupn_ns(struct aa_ns *view, const char *name, size_t n);
 92struct aa_ns *__aa_find_or_create_ns(struct aa_ns *parent, const char *name,
 93				     struct dentry *dir);
 94struct aa_ns *aa_prepare_ns(struct aa_ns *root, const char *name);
 95void __aa_remove_ns(struct aa_ns *ns);
 96
 97static inline struct aa_profile *aa_deref_parent(struct aa_profile *p)
 98{
 99	return rcu_dereference_protected(p->parent,
100					 mutex_is_locked(&p->ns->lock));
101}
102
103/**
104 * aa_get_ns - increment references count on @ns
105 * @ns: namespace to increment reference count of (MAYBE NULL)
106 *
107 * Returns: pointer to @ns, if @ns is NULL returns NULL
108 * Requires: @ns must be held with valid refcount when called
109 */
110static inline struct aa_ns *aa_get_ns(struct aa_ns *ns)
111{
112	if (ns)
113		aa_get_profile(ns->unconfined);
114
115	return ns;
116}
117
118/**
119 * aa_put_ns - decrement refcount on @ns
120 * @ns: namespace to put reference of
121 *
122 * Decrement reference count of @ns and if no longer in use free it
123 */
124static inline void aa_put_ns(struct aa_ns *ns)
125{
126	if (ns)
127		aa_put_profile(ns->unconfined);
128}
129
130/**
131 * __aa_findn_ns - find a namespace on a list by @name
132 * @head: list to search for namespace on  (NOT NULL)
133 * @name: name of namespace to look for  (NOT NULL)
134 * @n: length of @name
135 * Returns: unrefcounted namespace
136 *
137 * Requires: rcu_read_lock be held
138 */
139static inline struct aa_ns *__aa_findn_ns(struct list_head *head,
140					  const char *name, size_t n)
141{
142	return (struct aa_ns *)__policy_strn_find(head, name, n);
143}
144
145static inline struct aa_ns *__aa_find_ns(struct list_head *head,
146					 const char *name)
147{
148	return __aa_findn_ns(head, name, strlen(name));
149}
150
151#endif /* AA_NAMESPACE_H */