AppArmor: core policy routines

The basic routines and defines for AppArmor policy.  AppArmor policy
is defined by a few basic components.
      profiles - the basic unit of confinement contain all the information
                 to enforce policy on a task

                 Profiles tend to be named after an executable that they
                 will attach to but this is not required.
      namespaces - a container for a set of profiles that will be used
                 during attachment and transitions between profiles.
      sids - which provide a unique id for each profile

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>

2 files changed, 329 insertions, 0 deletions

diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
new file mode 100644
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+++ b/security/apparmor/include/policy.h
@@ -0,0 +1,305 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor policy definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#ifndef __AA_POLICY_H
+#define __AA_POLICY_H
+
+#include <linux/capability.h>
+#include <linux/cred.h>
+#include <linux/kref.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+
+#include "apparmor.h"
+#include "audit.h"
+#include "capability.h"
+#include "domain.h"
+#include "file.h"
+#include "resource.h"
+
+extern const char *profile_mode_names[];
+#define APPARMOR_NAMES_MAX_INDEX 3
+
+#define COMPLAIN_MODE(_profile) \
+        ((aa_g_profile_mode == APPARMOR_COMPLAIN) || \
+         ((_profile)->mode == APPARMOR_COMPLAIN))
+
+#define KILL_MODE(_profile) \
+        ((aa_g_profile_mode == APPARMOR_KILL) || \
+         ((_profile)->mode == APPARMOR_KILL))
+
+#define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)
+
+/*
+ * FIXME: currently need a clean way to replace and remove profiles as a
+ * set.  It should be done at the namespace level.
+ * Either, with a set of profiles loaded at the namespace level or via
+ * a mark and remove marked interface.
+ */
+enum profile_mode {
+        APPARMOR_ENFORCE,       /* enforce access rules */
+        APPARMOR_COMPLAIN,      /* allow and log access violations */
+        APPARMOR_KILL,          /* kill task on access violation */
+};
+
+enum profile_flags {
+        PFLAG_HAT = 1,                  /* profile is a hat */
+        PFLAG_UNCONFINED = 2,           /* profile is an unconfined profile */
+        PFLAG_NULL = 4,                 /* profile is null learning profile */
+        PFLAG_IX_ON_NAME_ERROR = 8,     /* fallback to ix on name lookup fail */
+        PFLAG_IMMUTABLE = 0x10,         /* don't allow changes/replacement */
+        PFLAG_USER_DEFINED = 0x20,      /* user based profile - lower privs */
+        PFLAG_NO_LIST_REF = 0x40,       /* list doesn't keep profile ref */
+        PFLAG_OLD_NULL_TRANS = 0x100,   /* use // as the null transition */
+
+        /* These flags must correspond with PATH_flags */
+        PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
+};
+
+struct aa_profile;
+
+/* struct aa_policy - common part of both namespaces and profiles
+ * @name: name of the object
+ * @hname - The hierarchical name
+ * @count: reference count of the obj
+ * @list: list policy object is on
+ * @profiles: head of the profiles list contained in the object
+ */
+struct aa_policy {
+        char *name;
+        char *hname;
+        struct kref count;
+        struct list_head list;
+        struct list_head profiles;
+};
+
+/* struct aa_ns_acct - accounting of profiles in namespace
+ * @max_size: maximum space allowed for all profiles in namespace
+ * @max_count: maximum number of profiles that can be in this namespace
+ * @size: current size of profiles
+ * @count: current count of profiles (includes null profiles)
+ */
+struct aa_ns_acct {
+        int max_size;
+        int max_count;
+        int size;
+        int count;
+};
+
+/* struct aa_namespace - namespace for a set of profiles
+ * @base: common policy
+ * @parent: parent of namespace
+ * @lock: lock for modifying the object
+ * @acct: accounting for the namespace
+ * @unconfined: special unconfined profile for the namespace
+ * @sub_ns: list of namespaces under the current namespace.
+ *
+ * An aa_namespace defines the set profiles that are searched to determine
+ * which profile to attach to a task.  Profiles can not be shared between
+ * aa_namespaces and profile names within a namespace are guaranteed to be
+ * unique.  When profiles in separate namespaces have the same name they
+ * are NOT considered to be equivalent.
+ *
+ * Namespaces are hierarchical and only namespaces and profiles below the
+ * current namespace are visible.
+ *
+ * Namespace names must be unique and can not contain the characters :/\0
+ *
+ * FIXME TODO: add vserver support of namespaces (can it all be done in
+ *             userspace?)
+ */
+struct aa_namespace {
+        struct aa_policy base;
+        struct aa_namespace *parent;
+        rwlock_t lock;
+        struct aa_ns_acct acct;
+        struct aa_profile *unconfined;
+        struct list_head sub_ns;
+};
+
+/* struct aa_profile - basic confinement data
+ * @base - base components of the profile (name, refcount, lists, lock ...)
+ * @parent: parent of profile
+ * @ns: namespace the profile is in
+ * @replacedby: is set to the profile that replaced this profile
+ * @rename: optional profile name that this profile renamed
+ * @xmatch: optional extended matching for unconfined executables names
+ * @xmatch_len: xmatch prefix len, used to determine xmatch priority
+ * @sid: the unique security id number of this profile
+ * @audit: the auditing mode of the profile
+ * @mode: the enforcement mode of the profile
+ * @flags: flags controlling profile behavior
+ * @path_flags: flags controlling path generation behavior
+ * @size: the memory consumed by this profiles rules
+ * @file: The set of rules governing basic file access and domain transitions
+ * @caps: capabilities for the profile
+ * @rlimits: rlimits for the profile
+ *
+ * The AppArmor profile contains the basic confinement data.  Each profile
+ * has a name, and exists in a namespace.  The @name and @exec_match are
+ * used to determine profile attachment against unconfined tasks.  All other
+ * attachments are determined by profile X transition rules.
+ *
+ * The @replacedby field is write protected by the profile lock.  Reads
+ * are assumed to be atomic, and are done without locking.
+ *
+ * Profiles have a hierarchy where hats and children profiles keep
+ * a reference to their parent.
+ *
+ * Profile names can not begin with a : and can not contain the \0
+ * character.  If a profile name begins with / it will be considered when
+ * determining profile attachment on "unconfined" tasks.
+ */
+struct aa_profile {
+        struct aa_policy base;
+        struct aa_profile *parent;
+
+        struct aa_namespace *ns;
+        struct aa_profile *replacedby;
+        const char *rename;
+
+        struct aa_dfa *xmatch;
+        int xmatch_len;
+        u32 sid;
+        enum audit_mode audit;
+        enum profile_mode mode;
+        u32 flags;
+        u32 path_flags;
+        int size;
+
+        struct aa_file_rules file;
+        struct aa_caps caps;
+        struct aa_rlimit rlimits;
+};