AppArmor: core policy routines

/*

 * 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;

};

extern struct aa_namespace *root_ns;

extern enum profile_mode aa_g_profile_mode;

void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);

bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view);

const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child);

int aa_alloc_root_ns(void);

void aa_free_root_ns(void);

void aa_free_namespace_kref(struct kref *kref);

struct aa_namespace *aa_find_namespace(struct aa_namespace *root,

				       const char *name);

static inline struct aa_policy *aa_get_common(struct aa_policy *c)

{

	if (c)

		kref_get(&c->count);

	return c;

}

/**

 * aa_get_namespace - increment references count on @ns

 * @ns: namespace to increment reference count of (MAYBE NULL)

 *

 * Returns: pointer to @ns, if @ns is NULL returns NULL

 * Requires: @ns must be held with valid refcount when called

 */

static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)

{

	if (ns)

		kref_get(&(ns->base.count));

	return ns;

}

/**

 * aa_put_namespace - decrement refcount on @ns

 * @ns: namespace to put reference of

 *

 * Decrement reference count of @ns and if no longer in use free it

 */

static inline void aa_put_namespace(struct aa_namespace *ns)

{

	if (ns)

		kref_put(&ns->base.count, aa_free_namespace_kref);

}

struct aa_profile *aa_alloc_profile(const char *name);

struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat);

void aa_free_profile_kref(struct kref *kref);

struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);

struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name);

struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name);

ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace);

ssize_t aa_remove_profiles(char *name, size_t size);

#define PROF_ADD 1

#define PROF_REPLACE 0

#define unconfined(X) ((X)->flags & PFLAG_UNCONFINED)

/**

 * aa_newest_version - find the newest version of @profile

 * @profile: the profile to check for newer versions of (NOT NULL)

 *

 * Returns: newest version of @profile, if @profile is the newest version

 *          return @profile.

 *

 * NOTE: the profile returned is not refcounted, The refcount on @profile

 * must be held until the caller decides what to do with the returned newest

 * version.

 */

static inline struct aa_profile *aa_newest_version(struct aa_profile *profile)

{

	while (profile->replacedby)

		profile = profile->replacedby;

	return profile;

}

/**

 * aa_get_profile - increment refcount on profile @p

 * @p: profile  (MAYBE NULL)

 *

 * Returns: pointer to @p if @p is NULL will return NULL

 * Requires: @p must be held with valid refcount when called

 */

static inline struct aa_profile *aa_get_profile(struct aa_profile *p)

{

	if (p)

		kref_get(&(p->base.count));

	return p;

}

/**

 * aa_put_profile - decrement refcount on profile @p

 * @p: profile  (MAYBE NULL)

 */

static inline void aa_put_profile(struct aa_profile *p)

{

	if (p)

		kref_put(&p->base.count, aa_free_profile_kref);

}

static inline int AUDIT_MODE(struct aa_profile *profile)

{

	if (aa_g_audit != AUDIT_NORMAL)

		return aa_g_audit;

	return profile->audit;

}

bool aa_may_manage_policy(int op);

#endif /* __AA_POLICY_H */

/*

 * AppArmor security module

 *

 * This file contains AppArmor security identifier (sid) definitions

 *

 * 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_SID_H

#define __AA_SID_H

#include <linux/types.h>

struct aa_profile;

u32 aa_alloc_sid(void);

void aa_free_sid(u32 sid);

#endif /* __AA_SID_H */

/*

 * AppArmor security module

 *

 * This file contains AppArmor security identifier (sid) manipulation fns

 *

 * 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.

 *

 *

 * AppArmor allocates a unique sid for every profile loaded.  If a profile

 * is replaced it receives the sid of the profile it is replacing.

 *

 * The sid value of 0 is invalid.

 */

#include <linux/spinlock.h>

#include <linux/errno.h>

#include <linux/err.h>

#include "include/sid.h"

/* global counter from which sids are allocated */

static u32 global_sid;

static DEFINE_SPINLOCK(sid_lock);

/* TODO FIXME: add sid to profile mapping, and sid recycling */

/**

 * aa_alloc_sid - allocate a new sid for a profile

 */

u32 aa_alloc_sid(void)

{

	u32 sid;

	/*

	 * TODO FIXME: sid recycling - part of profile mapping table

	 */

	spin_lock(&sid_lock);

	sid = (++global_sid);

	spin_unlock(&sid_lock);

	return sid;

}

/**

 * aa_free_sid - free a sid

 * @sid: sid to free

 */

void aa_free_sid(u32 sid)

{

	;			/* NOP ATM */

}