/*
   * AppArmor security module
   *
   * This file contains AppArmor policy manipulation functions
   *
   * 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.
   *
   *
   * AppArmor policy is based around profiles, which contain the rules a
   * task is confined by.  Every task in the system has a profile attached
   * to it determined either by matching "unconfined" tasks against the
   * visible set of profiles or by following a profiles attachment rules.
   *
   * Each profile exists in a profile namespace which is a container of
   * visible profiles.  Each namespace contains a special "unconfined" profile,
   * which doesn't enforce any confinement on a task beyond DAC.
   *
   * Namespace and profile names can be written together in either
   * of two syntaxes.
   *	:namespace:profile - used by kernel interfaces for easy detection
   *	namespace://profile - used by policy
   *
   * Profile names can not start with : or @ or ^ and may not contain \0
   *
   * Reserved profile names
   *	unconfined - special automatically generated unconfined profile
   *	inherit - special name to indicate profile inheritance
   *	null-XXXX-YYYY - special automatically generated learning profiles
   *
   * Namespace names may not start with / or @ and may not contain \0 or :
   * Reserved namespace names
   *	user-XXXX - user defined profiles
   *
   * a // in a profile or namespace name indicates a hierarchical name with the
   * name before the // being the parent and the name after the child.
   *
   * Profile and namespace hierarchies serve two different but similar purposes.
   * The namespace contains the set of visible profiles that are considered
   * for attachment.  The hierarchy of namespaces allows for virtualizing
   * the namespace so that for example a chroot can have its own set of profiles
   * which may define some local user namespaces.
   * The profile hierarchy severs two distinct purposes,
   * -  it allows for sub profiles or hats, which allows an application to run
   *    subprograms under its own profile with different restriction than it
   *    self, and not have it use the system profile.
   *    eg. if a mail program starts an editor, the policy might make the
   *        restrictions tighter on the editor tighter than the mail program,
   *        and definitely different than general editor restrictions
   * - it allows for binary hierarchy of profiles, so that execution history
   *   is preserved.  This feature isn't exploited by AppArmor reference policy
   *   but is allowed.  NOTE: this is currently suboptimal because profile
   *   aliasing is not currently implemented so that a profile for each
   *   level must be defined.
   *   eg. /bin/bash///bin/ls as a name would indicate /bin/ls was started
   *       from /bin/bash
   *
   *   A profile or namespace name that can contain one or more // separators
   *   is referred to as an hname (hierarchical).
   *   eg.  /bin/bash//bin/ls
   *
   *   An fqname is a name that may contain both namespace and profile hnames.
   *   eg. :ns:/bin/bash//bin/ls
   *
   * NOTES:
   *   - locking of profile lists is currently fairly coarse.  All profile
   *     lists within a namespace use the namespace lock.
   * FIXME: move profile lists to using rcu_lists
   */
  
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/string.h>
  
  #include "include/apparmor.h"
  #include "include/capability.h"
  #include "include/context.h"
  #include "include/file.h"
  #include "include/ipc.h"
  #include "include/match.h"
  #include "include/path.h"
  #include "include/policy.h"
  #include "include/policy_unpack.h"
  #include "include/resource.h"

  
  
  /* root profile namespace */
  struct aa_namespace *root_ns;

  const char *const aa_profile_mode_names[] = {

  	"enforce",
  	"complain",
  	"kill",

  	"unconfined",

  };
  
  /**
   * hname_tail - find the last component of an hname
   * @name: hname to find the base profile name component of  (NOT NULL)
   *
   * Returns: the tail (base profile name) name component of an hname
   */
  static const char *hname_tail(const char *hname)
  {
  	char *split;
  	hname = strim((char *)hname);
  	for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
  		hname = split + 2;
  
  	return hname;
  }
  
  /**
   * policy_init - initialize a policy structure
   * @policy: policy to initialize  (NOT NULL)
   * @prefix: prefix name if any is required.  (MAYBE NULL)
   * @name: name of the policy, init will make a copy of it  (NOT NULL)
   *
   * Note: this fn creates a copy of strings passed in
   *
   * Returns: true if policy init successful
   */
  static bool policy_init(struct aa_policy *policy, const char *prefix,
  			const char *name)
  {
  	/* freed by policy_free */
  	if (prefix) {
  		policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
  					GFP_KERNEL);
  		if (policy->hname)
  			sprintf(policy->hname, "%s//%s", prefix, name);
  	} else
  		policy->hname = kstrdup(name, GFP_KERNEL);
  	if (!policy->hname)
  		return 0;
  	/* base.name is a substring of fqname */
  	policy->name = (char *)hname_tail(policy->hname);
  	INIT_LIST_HEAD(&policy->list);
  	INIT_LIST_HEAD(&policy->profiles);

  
  	return 1;
  }
  
  /**
   * policy_destroy - free the elements referenced by @policy
   * @policy: policy that is to have its elements freed  (NOT NULL)
   */
  static void policy_destroy(struct aa_policy *policy)
  {
  	/* still contains profiles -- invalid */

  	if (on_list_rcu(&policy->profiles)) {

  		AA_ERROR("%s: internal error, "
  			 "policy '%s' still contains profiles
  ",
  			 __func__, policy->name);
  		BUG();
  	}

  	if (on_list_rcu(&policy->list)) {

  		AA_ERROR("%s: internal error, policy '%s' still on list
  ",
  			 __func__, policy->name);
  		BUG();
  	}
  
  	/* don't free name as its a subset of hname */
  	kzfree(policy->hname);
  }
  
  /**
   * __policy_find - find a policy by @name on a policy list
   * @head: list to search  (NOT NULL)
   * @name: name to search for  (NOT NULL)
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted policy that match @name or NULL if not found
   */
  static struct aa_policy *__policy_find(struct list_head *head, const char *name)
  {
  	struct aa_policy *policy;

  	list_for_each_entry_rcu(policy, head, list) {

  		if (!strcmp(policy->name, name))
  			return policy;
  	}
  	return NULL;
  }
  
  /**
   * __policy_strn_find - find a policy that's name matches @len chars of @str
   * @head: list to search  (NOT NULL)
   * @str: string to search for  (NOT NULL)
   * @len: length of match required
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted policy that match @str or NULL if not found
   *
   * if @len == strlen(@strlen) then this is equiv to __policy_find
   * other wise it allows searching for policy by a partial match of name
   */
  static struct aa_policy *__policy_strn_find(struct list_head *head,
  					    const char *str, int len)
  {
  	struct aa_policy *policy;

  	list_for_each_entry_rcu(policy, head, list) {

  		if (aa_strneq(policy->name, str, len))
  			return policy;
  	}
  
  	return NULL;
  }
  
  /*
   * Routines for AppArmor namespaces
   */
  
  static const char *hidden_ns_name = "---";
  /**
   * aa_ns_visible - test if @view is visible from @curr
   * @curr: namespace to treat as the parent (NOT NULL)
   * @view:  namespace to test if visible from @curr (NOT NULL)
   *
   * Returns: true if @view is visible from @curr else false
   */
  bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view)
  {
  	if (curr == view)
  		return true;
  
  	for ( ; view; view = view->parent) {
  		if (view->parent == curr)
  			return true;
  	}
  	return false;
  }
  
  /**
   * aa_na_name - Find the ns name to display for @view from @curr
   * @curr - current namespace (NOT NULL)
   * @view - namespace attempting to view (NOT NULL)
   *
   * Returns: name of @view visible from @curr
   */
  const char *aa_ns_name(struct aa_namespace *curr, struct aa_namespace *view)
  {
  	/* if view == curr then the namespace name isn't displayed */
  	if (curr == view)
  		return "";
  
  	if (aa_ns_visible(curr, view)) {
  		/* at this point if a ns is visible it is in a view ns
  		 * thus the curr ns.hname is a prefix of its name.
  		 * Only output the virtualized portion of the name
  		 * Add + 2 to skip over // separating curr hname prefix
  		 * from the visible tail of the views hname
  		 */
  		return view->base.hname + strlen(curr->base.hname) + 2;
  	} else
  		return hidden_ns_name;
  }
  
  /**
   * alloc_namespace - allocate, initialize and return a new namespace
   * @prefix: parent namespace name (MAYBE NULL)
   * @name: a preallocated name  (NOT NULL)
   *
   * Returns: refcounted namespace or NULL on failure.
   */
  static struct aa_namespace *alloc_namespace(const char *prefix,
  					    const char *name)
  {
  	struct aa_namespace *ns;
  
  	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
  	AA_DEBUG("%s(%p)
  ", __func__, ns);
  	if (!ns)
  		return NULL;
  	if (!policy_init(&ns->base, prefix, name))
  		goto fail_ns;
  
  	INIT_LIST_HEAD(&ns->sub_ns);

  	mutex_init(&ns->lock);

  
  	/* released by free_namespace */
  	ns->unconfined = aa_alloc_profile("unconfined");
  	if (!ns->unconfined)
  		goto fail_unconfined;

  	ns->unconfined->flags = PFLAG_IX_ON_NAME_ERROR |
  		PFLAG_IMMUTABLE | PFLAG_NS_COUNT;
  	ns->unconfined->mode = APPARMOR_UNCONFINED;

  	/* ns and ns->unconfined share ns->unconfined refcount */
  	ns->unconfined->ns = ns;

  	atomic_set(&ns->uniq_null, 0);

  	return ns;
  
  fail_unconfined:

  	kzfree(ns->base.hname);

  fail_ns:
  	kzfree(ns);
  	return NULL;
  }
  
  /**
   * free_namespace - free a profile namespace
   * @ns: the namespace to free  (MAYBE NULL)
   *
   * Requires: All references to the namespace must have been put, if the
   *           namespace was referenced by a profile confining a task,
   */
  static void free_namespace(struct aa_namespace *ns)
  {
  	if (!ns)
  		return;
  
  	policy_destroy(&ns->base);
  	aa_put_namespace(ns->parent);

  	ns->unconfined->ns = NULL;

  	aa_free_profile(ns->unconfined);

  	kzfree(ns);
  }
  
  /**

   * __aa_find_namespace - find a namespace on a list by @name
   * @head: list to search for namespace on  (NOT NULL)
   * @name: name of namespace to look for  (NOT NULL)
   *
   * Returns: unrefcounted namespace
   *

   * Requires: rcu_read_lock be held

   */
  static struct aa_namespace *__aa_find_namespace(struct list_head *head,
  						const char *name)
  {
  	return (struct aa_namespace *)__policy_find(head, name);
  }
  
  /**
   * aa_find_namespace  -  look up a profile namespace on the namespace list
   * @root: namespace to search in  (NOT NULL)
   * @name: name of namespace to find  (NOT NULL)
   *
   * Returns: a refcounted namespace on the list, or NULL if no namespace
   *          called @name exists.
   *
   * refcount released by caller
   */
  struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
  				       const char *name)
  {
  	struct aa_namespace *ns = NULL;

  	rcu_read_lock();

  	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));

  	rcu_read_unlock();

  
  	return ns;
  }
  
  /**
   * aa_prepare_namespace - find an existing or create a new namespace of @name
   * @name: the namespace to find or add  (MAYBE NULL)
   *
   * Returns: refcounted namespace or NULL if failed to create one
   */
  static struct aa_namespace *aa_prepare_namespace(const char *name)
  {
  	struct aa_namespace *ns, *root;
  
  	root = aa_current_profile()->ns;

  	mutex_lock(&root->lock);

  
  	/* if name isn't specified the profile is loaded to the current ns */
  	if (!name) {
  		/* released by caller */
  		ns = aa_get_namespace(root);
  		goto out;
  	}
  
  	/* try and find the specified ns and if it doesn't exist create it */
  	/* released by caller */
  	ns = aa_get_namespace(__aa_find_namespace(&root->sub_ns, name));
  	if (!ns) {

  		ns = alloc_namespace(root->base.hname, name);
  		if (!ns)
  			goto out;

  		if (__aa_fs_namespace_mkdir(ns, ns_subns_dir(root), name)) {
  			AA_ERROR("Failed to create interface for ns %s
  ",
  				 ns->base.name);
  			free_namespace(ns);
  			ns = NULL;
  			goto out;
  		}

  		ns->parent = aa_get_namespace(root);
  		list_add_rcu(&ns->base.list, &root->sub_ns);
  		/* add list ref */
  		aa_get_namespace(ns);

  	}
  out:

  	mutex_unlock(&root->lock);

  
  	/* return ref */
  	return ns;
  }
  
  /**
   * __list_add_profile - add a profile to a list
   * @list: list to add it to  (NOT NULL)
   * @profile: the profile to add  (NOT NULL)
   *
   * refcount @profile, should be put by __list_remove_profile
   *
   * Requires: namespace lock be held, or list not be shared
   */
  static void __list_add_profile(struct list_head *list,
  			       struct aa_profile *profile)
  {

  	list_add_rcu(&profile->base.list, list);

  	/* get list reference */
  	aa_get_profile(profile);
  }
  
  /**
   * __list_remove_profile - remove a profile from the list it is on
   * @profile: the profile to remove  (NOT NULL)
   *
   * remove a profile from the list, warning generally removal should
   * be done with __replace_profile as most profile removals are
   * replacements to the unconfined profile.
   *
   * put @profile list refcount
   *
   * Requires: namespace lock be held, or list not have been live
   */
  static void __list_remove_profile(struct aa_profile *profile)
  {

  	list_del_rcu(&profile->base.list);
  	aa_put_profile(profile);

  }

  static void __profile_list_release(struct list_head *head);
  
  /**
   * __remove_profile - remove old profile, and children
   * @profile: profile to be replaced  (NOT NULL)
   *
   * Requires: namespace list lock be held, or list not be shared
   */
  static void __remove_profile(struct aa_profile *profile)
  {
  	/* release any children lists first */
  	__profile_list_release(&profile->base.profiles);
  	/* released by free_profile */

  	__aa_update_replacedby(profile, profile->ns->unconfined);

  	__aa_fs_profile_rmdir(profile);

  	__list_remove_profile(profile);
  }
  
  /**
   * __profile_list_release - remove all profiles on the list and put refs
   * @head: list of profiles  (NOT NULL)
   *
   * Requires: namespace lock be held
   */
  static void __profile_list_release(struct list_head *head)
  {
  	struct aa_profile *profile, *tmp;
  	list_for_each_entry_safe(profile, tmp, head, base.list)
  		__remove_profile(profile);
  }
  
  static void __ns_list_release(struct list_head *head);
  
  /**
   * destroy_namespace - remove everything contained by @ns
   * @ns: namespace to have it contents removed  (NOT NULL)
   */
  static void destroy_namespace(struct aa_namespace *ns)
  {
  	if (!ns)
  		return;

  	mutex_lock(&ns->lock);

  	/* release all profiles in this namespace */
  	__profile_list_release(&ns->base.profiles);
  
  	/* release all sub namespaces */
  	__ns_list_release(&ns->sub_ns);

  	if (ns->parent)

  		__aa_update_replacedby(ns->unconfined, ns->parent->unconfined);

  	__aa_fs_namespace_rmdir(ns);

  	mutex_unlock(&ns->lock);
  }

  /**
   * __remove_namespace - remove a namespace and all its children
   * @ns: namespace to be removed  (NOT NULL)
   *
   * Requires: ns->parent->lock be held and ns removed from parent.
   */
  static void __remove_namespace(struct aa_namespace *ns)
  {

  	/* remove ns from namespace list */

  	list_del_rcu(&ns->base.list);

  	destroy_namespace(ns);

  	aa_put_namespace(ns);

  }
  
  /**
   * __ns_list_release - remove all profile namespaces on the list put refs
   * @head: list of profile namespaces  (NOT NULL)
   *
   * Requires: namespace lock be held
   */
  static void __ns_list_release(struct list_head *head)
  {
  	struct aa_namespace *ns, *tmp;
  	list_for_each_entry_safe(ns, tmp, head, base.list)
  		__remove_namespace(ns);
  
  }
  
  /**
   * aa_alloc_root_ns - allocate the root profile namespace
   *
   * Returns: %0 on success else error
   *
   */
  int __init aa_alloc_root_ns(void)
  {
  	/* released by aa_free_root_ns - used as list ref*/
  	root_ns = alloc_namespace(NULL, "root");
  	if (!root_ns)
  		return -ENOMEM;
  
  	return 0;
  }
  
   /**
    * aa_free_root_ns - free the root profile namespace
    */
  void __init aa_free_root_ns(void)
   {
  	 struct aa_namespace *ns = root_ns;
  	 root_ns = NULL;
  
  	 destroy_namespace(ns);
  	 aa_put_namespace(ns);
  }

  
  static void free_replacedby(struct aa_replacedby *r)
  {
  	if (r) {

  		/* r->profile will not be updated any more as r is dead */
  		aa_put_profile(rcu_dereference_protected(r->profile, true));

  		kzfree(r);
  	}
  }
  
  
  void aa_free_replacedby_kref(struct kref *kref)
  {
  	struct aa_replacedby *r = container_of(kref, struct aa_replacedby,
  					       count);
  	free_replacedby(r);
  }

  /**

   * aa_free_profile - free a profile

   * @profile: the profile to free  (MAYBE NULL)
   *
   * Free a profile, its hats and null_profile. All references to the profile,
   * its hats and null_profile must have been put.
   *
   * If the profile was referenced from a task context, free_profile() will
   * be called from an rcu callback routine, so we must not sleep here.
   */

  void aa_free_profile(struct aa_profile *profile)

  {
  	AA_DEBUG("%s(%p)
  ", __func__, profile);
  
  	if (!profile)
  		return;

  	/* free children profiles */
  	policy_destroy(&profile->base);

  	aa_put_profile(rcu_access_pointer(profile->parent));

  
  	aa_put_namespace(profile->ns);
  	kzfree(profile->rename);
  
  	aa_free_file_rules(&profile->file);
  	aa_free_cap_rules(&profile->caps);
  	aa_free_rlimit_rules(&profile->rlimits);

  	kzfree(profile->dirname);

  	aa_put_dfa(profile->xmatch);

  	aa_put_dfa(profile->policy.dfa);

  	aa_put_replacedby(profile->replacedby);

  	kzfree(profile->hash);

  	kzfree(profile);
  }
  
  /**

   * aa_free_profile_rcu - free aa_profile by rcu (called by aa_free_profile_kref)
   * @head: rcu_head callback for freeing of a profile  (NOT NULL)
   */
  static void aa_free_profile_rcu(struct rcu_head *head)
  {

  	struct aa_profile *p = container_of(head, struct aa_profile, rcu);
  	if (p->flags & PFLAG_NS_COUNT)
  		free_namespace(p->ns);
  	else

  		aa_free_profile(p);

  }
  
  /**

   * aa_free_profile_kref - free aa_profile by kref (called by aa_put_profile)
   * @kr: kref callback for freeing of a profile  (NOT NULL)
   */
  void aa_free_profile_kref(struct kref *kref)
  {

  	struct aa_profile *p = container_of(kref, struct aa_profile, count);

  	call_rcu(&p->rcu, aa_free_profile_rcu);

  }

  /**
   * aa_alloc_profile - allocate, initialize and return a new profile
   * @hname: name of the profile  (NOT NULL)
   *
   * Returns: refcount profile or NULL on failure
   */
  struct aa_profile *aa_alloc_profile(const char *hname)
  {
  	struct aa_profile *profile;
  
  	/* freed by free_profile - usually through aa_put_profile */
  	profile = kzalloc(sizeof(*profile), GFP_KERNEL);
  	if (!profile)
  		return NULL;

  	profile->replacedby = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL);
  	if (!profile->replacedby)
  		goto fail;
  	kref_init(&profile->replacedby->count);
  
  	if (!policy_init(&profile->base, NULL, hname))
  		goto fail;

  	kref_init(&profile->count);

  
  	/* refcount released by caller */
  	return profile;

  
  fail:
  	kzfree(profile->replacedby);
  	kzfree(profile);
  
  	return NULL;

  }
  
  /**
   * aa_new_null_profile - create a new null-X learning profile
   * @parent: profile that caused this profile to be created (NOT NULL)
   * @hat: true if the null- learning profile is a hat
   *
   * Create a null- complain mode profile used in learning mode.  The name of
   * the profile is unique and follows the format of parent//null-<uniq>.
   *
   * null profiles are added to the profile list but the list does not
   * hold a count on them so that they are automatically released when
   * not in use.
   *
   * Returns: new refcounted profile else NULL on failure
   */
  struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat)
  {
  	struct aa_profile *profile = NULL;
  	char *name;
  	int uniq = atomic_inc_return(&parent->ns->uniq_null);
  
  	/* freed below */
  	name = kmalloc(strlen(parent->base.hname) + 2 + 7 + 8, GFP_KERNEL);
  	if (!name)
  		goto fail;
  	sprintf(name, "%s//null-%x", parent->base.hname, uniq);
  
  	profile = aa_alloc_profile(name);
  	kfree(name);
  	if (!profile)
  		goto fail;
  
  	profile->mode = APPARMOR_COMPLAIN;
  	profile->flags = PFLAG_NULL;
  	if (hat)
  		profile->flags |= PFLAG_HAT;
  
  	/* released on free_profile */

  	rcu_assign_pointer(profile->parent, aa_get_profile(parent));

  	profile->ns = aa_get_namespace(parent->ns);

  	mutex_lock(&profile->ns->lock);

  	__list_add_profile(&parent->base.profiles, profile);

  	mutex_unlock(&profile->ns->lock);

  
  	/* refcount released by caller */
  	return profile;
  
  fail:
  	return NULL;
  }

  /* TODO: profile accounting - setup in remove */
  
  /**
   * __find_child - find a profile on @head list with a name matching @name
   * @head: list to search  (NOT NULL)
   * @name: name of profile (NOT NULL)
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted profile ptr, or NULL if not found
   */
  static struct aa_profile *__find_child(struct list_head *head, const char *name)
  {
  	return (struct aa_profile *)__policy_find(head, name);
  }
  
  /**
   * __strn_find_child - find a profile on @head list using substring of @name
   * @head: list to search  (NOT NULL)
   * @name: name of profile (NOT NULL)
   * @len: length of @name substring to match
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted profile ptr, or NULL if not found
   */
  static struct aa_profile *__strn_find_child(struct list_head *head,
  					    const char *name, int len)
  {
  	return (struct aa_profile *)__policy_strn_find(head, name, len);
  }
  
  /**
   * aa_find_child - find a profile by @name in @parent
   * @parent: profile to search  (NOT NULL)
   * @name: profile name to search for  (NOT NULL)
   *
   * Returns: a refcounted profile or NULL if not found
   */
  struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name)
  {
  	struct aa_profile *profile;

  	rcu_read_lock();

  	do {
  		profile = __find_child(&parent->base.profiles, name);
  	} while (profile && !aa_get_profile_not0(profile));

  	rcu_read_unlock();

  
  	/* refcount released by caller */
  	return profile;
  }
  
  /**
   * __lookup_parent - lookup the parent of a profile of name @hname
   * @ns: namespace to lookup profile in  (NOT NULL)
   * @hname: hierarchical profile name to find parent of  (NOT NULL)
   *
   * Lookups up the parent of a fully qualified profile name, the profile
   * that matches hname does not need to exist, in general this
   * is used to load a new profile.
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted policy or NULL if not found
   */
  static struct aa_policy *__lookup_parent(struct aa_namespace *ns,
  					 const char *hname)
  {
  	struct aa_policy *policy;
  	struct aa_profile *profile = NULL;
  	char *split;
  
  	policy = &ns->base;
  
  	for (split = strstr(hname, "//"); split;) {
  		profile = __strn_find_child(&policy->profiles, hname,
  					    split - hname);
  		if (!profile)
  			return NULL;
  		policy = &profile->base;
  		hname = split + 2;
  		split = strstr(hname, "//");
  	}
  	if (!profile)
  		return &ns->base;
  	return &profile->base;
  }
  
  /**
   * __lookup_profile - lookup the profile matching @hname
   * @base: base list to start looking up profile name from  (NOT NULL)
   * @hname: hierarchical profile name  (NOT NULL)
   *

   * Requires: rcu_read_lock be held

   *
   * Returns: unrefcounted profile pointer or NULL if not found
   *
   * Do a relative name lookup, recursing through profile tree.
   */
  static struct aa_profile *__lookup_profile(struct aa_policy *base,
  					   const char *hname)
  {
  	struct aa_profile *profile = NULL;
  	char *split;
  
  	for (split = strstr(hname, "//"); split;) {
  		profile = __strn_find_child(&base->profiles, hname,
  					    split - hname);
  		if (!profile)
  			return NULL;
  
  		base = &profile->base;
  		hname = split + 2;
  		split = strstr(hname, "//");
  	}
  
  	profile = __find_child(&base->profiles, hname);
  
  	return profile;
  }
  
  /**
   * aa_lookup_profile - find a profile by its full or partial name
   * @ns: the namespace to start from (NOT NULL)
   * @hname: name to do lookup on.  Does not contain namespace prefix (NOT NULL)
   *
   * Returns: refcounted profile or NULL if not found
   */
  struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
  {
  	struct aa_profile *profile;

  	rcu_read_lock();
  	do {
  		profile = __lookup_profile(&ns->base, hname);
  	} while (profile && !aa_get_profile_not0(profile));
  	rcu_read_unlock();

  	/* the unconfined profile is not in the regular profile list */
  	if (!profile && strcmp(hname, "unconfined") == 0)

  		profile = aa_get_newest_profile(ns->unconfined);

  	/* refcount released by caller */
  	return profile;
  }
  
  /**
   * replacement_allowed - test to see if replacement is allowed
   * @profile: profile to test if it can be replaced  (MAYBE NULL)
   * @noreplace: true if replacement shouldn't be allowed but addition is okay
   * @info: Returns - info about why replacement failed (NOT NULL)
   *
   * Returns: %0 if replacement allowed else error code
   */
  static int replacement_allowed(struct aa_profile *profile, int noreplace,
  			       const char **info)
  {
  	if (profile) {
  		if (profile->flags & PFLAG_IMMUTABLE) {
  			*info = "cannot replace immutible profile";
  			return -EPERM;
  		} else if (noreplace) {
  			*info = "profile already exists";
  			return -EEXIST;
  		}
  	}
  	return 0;
  }
  
  /**

   * aa_audit_policy - Do auditing of policy changes
   * @op: policy operation being performed
   * @gfp: memory allocation flags
   * @name: name of profile being manipulated (NOT NULL)
   * @info: any extra information to be audited (MAYBE NULL)
   * @error: error code
   *
   * Returns: the error to be returned after audit is done
   */
  static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
  			int error)
  {
  	struct common_audit_data sa;

  	struct apparmor_audit_data aad = {0,};

  	sa.type = LSM_AUDIT_DATA_NONE;

  	sa.aad = &aad;
  	aad.op = op;
  	aad.name = name;
  	aad.info = info;
  	aad.error = error;

  
  	return aa_audit(AUDIT_APPARMOR_STATUS, __aa_current_profile(), gfp,
  			&sa, NULL);
  }

  bool policy_view_capable(void)
  {
  	struct user_namespace *user_ns = current_user_ns();
  	bool response = false;
  
  	if (ns_capable(user_ns, CAP_MAC_ADMIN))
  		response = true;
  
  	return response;
  }
  
  bool policy_admin_capable(void)
  {
  	return policy_view_capable() && !aa_g_lock_policy;
  }

  /**
   * aa_may_manage_policy - can the current task manage policy
   * @op: the policy manipulation operation being done
   *
   * Returns: true if the task is allowed to manipulate policy
   */
  bool aa_may_manage_policy(int op)
  {
  	/* check if loading policy is locked out */
  	if (aa_g_lock_policy) {
  		audit_policy(op, GFP_KERNEL, NULL, "policy_locked", -EACCES);
  		return 0;
  	}

  	if (!policy_admin_capable()) {

  		audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
  		return 0;
  	}
  
  	return 1;
  }

  static struct aa_profile *__list_lookup_parent(struct list_head *lh,
  					       struct aa_profile *profile)
  {
  	const char *base = hname_tail(profile->base.hname);
  	long len = base - profile->base.hname;
  	struct aa_load_ent *ent;
  
  	/* parent won't have trailing // so remove from len */
  	if (len <= 2)
  		return NULL;
  	len -= 2;
  
  	list_for_each_entry(ent, lh, list) {
  		if (ent->new == profile)
  			continue;
  		if (strncmp(ent->new->base.hname, profile->base.hname, len) ==
  		    0 && ent->new->base.hname[len] == 0)
  			return ent->new;
  	}
  
  	return NULL;
  }
  
  /**
   * __replace_profile - replace @old with @new on a list
   * @old: profile to be replaced  (NOT NULL)
   * @new: profile to replace @old with  (NOT NULL)

   * @share_replacedby: transfer @old->replacedby to @new

   *
   * Will duplicate and refcount elements that @new inherits from @old
   * and will inherit @old children.
   *
   * refcount @new for list, put @old list refcount
   *
   * Requires: namespace list lock be held, or list not be shared
   */

  static void __replace_profile(struct aa_profile *old, struct aa_profile *new,
  			      bool share_replacedby)

  {
  	struct aa_profile *child, *tmp;
  
  	if (!list_empty(&old->base.profiles)) {
  		LIST_HEAD(lh);

  		list_splice_init_rcu(&old->base.profiles, &lh, synchronize_rcu);

  
  		list_for_each_entry_safe(child, tmp, &lh, base.list) {
  			struct aa_profile *p;
  
  			list_del_init(&child->base.list);
  			p = __find_child(&new->base.profiles, child->base.name);
  			if (p) {
  				/* @p replaces @child  */

  				__replace_profile(child, p, share_replacedby);

  				continue;
  			}
  
  			/* inherit @child and its children */
  			/* TODO: update hname of inherited children */
  			/* list refcount transferred to @new */

  			p = aa_deref_parent(child);

  			rcu_assign_pointer(child->parent, aa_get_profile(new));
  			list_add_rcu(&child->base.list, &new->base.profiles);
  			aa_put_profile(p);

  		}
  	}

  	if (!rcu_access_pointer(new->parent)) {

  		struct aa_profile *parent = aa_deref_parent(old);

  		rcu_assign_pointer(new->parent, aa_get_profile(parent));
  	}

  	__aa_update_replacedby(old, new);
  	if (share_replacedby) {
  		aa_put_replacedby(new->replacedby);
  		new->replacedby = aa_get_replacedby(old->replacedby);

  	} else if (!rcu_access_pointer(new->replacedby->profile))
  		/* aafs interface uses replacedby */
  		rcu_assign_pointer(new->replacedby->profile,
  				   aa_get_profile(new));
  	__aa_fs_profile_migrate_dents(old, new);

  
  	if (list_empty(&new->base.list)) {
  		/* new is not on a list already */

  		list_replace_rcu(&old->base.list, &new->base.list);

  		aa_get_profile(new);
  		aa_put_profile(old);
  	} else
  		__list_remove_profile(old);
  }
  
  /**
   * __lookup_replace - lookup replacement information for a profile
   * @ns - namespace the lookup occurs in
   * @hname - name of profile to lookup
   * @noreplace - true if not replacing an existing profile
   * @p - Returns: profile to be replaced
   * @info - Returns: info string on why lookup failed
   *
   * Returns: profile to replace (no ref) on success else ptr error
   */
  static int __lookup_replace(struct aa_namespace *ns, const char *hname,
  			    bool noreplace, struct aa_profile **p,
  			    const char **info)
  {
  	*p = aa_get_profile(__lookup_profile(&ns->base, hname));
  	if (*p) {
  		int error = replacement_allowed(*p, noreplace, info);
  		if (error) {
  			*info = "profile can not be replaced";
  			return error;
  		}
  	}
  
  	return 0;
  }

  /**
   * aa_replace_profiles - replace profile(s) on the profile list
   * @udata: serialized data stream  (NOT NULL)
   * @size: size of the serialized data stream
   * @noreplace: true if only doing addition, no replacement allowed
   *
   * unpack and replace a profile on the profile list and uses of that profile
   * by any aa_task_cxt.  If the profile does not exist on the profile list
   * it is added.
   *
   * Returns: size of data consumed else error code on failure.
   */
  ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
  {

  	const char *ns_name, *info = NULL;

  	struct aa_namespace *ns = NULL;
  	struct aa_load_ent *ent, *tmp;

  	int op = OP_PROF_REPL;
  	ssize_t error;

  	LIST_HEAD(lh);

  
  	/* released below */

  	error = aa_unpack(udata, size, &lh, &ns_name);
  	if (error)
  		goto out;

  
  	/* released below */
  	ns = aa_prepare_namespace(ns_name);
  	if (!ns) {

  		error = audit_policy(op, GFP_KERNEL, ns_name,
  				     "failed to prepare namespace", -ENOMEM);
  		goto free;

  	}

  	mutex_lock(&ns->lock);

  	/* setup parent and ns info */
  	list_for_each_entry(ent, &lh, list) {
  		struct aa_policy *policy;

  		error = __lookup_replace(ns, ent->new->base.hname, noreplace,
  					 &ent->old, &info);
  		if (error)
  			goto fail_lock;
  
  		if (ent->new->rename) {
  			error = __lookup_replace(ns, ent->new->rename,
  						 noreplace, &ent->rename,
  						 &info);
  			if (error)
  				goto fail_lock;

  		}

  		/* released when @new is freed */
  		ent->new->ns = aa_get_namespace(ns);
  
  		if (ent->old || ent->rename)
  			continue;
  
  		/* no ref on policy only use inside lock */
  		policy = __lookup_parent(ns, ent->new->base.hname);
  		if (!policy) {
  			struct aa_profile *p;
  			p = __list_lookup_parent(&lh, ent->new);
  			if (!p) {
  				error = -ENOENT;
  				info = "parent does not exist";

  				goto fail_lock;
  			}

  			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
  		} else if (policy != &ns->base) {

  			/* released on profile replacement or free_profile */

  			struct aa_profile *p = (struct aa_profile *) policy;
  			rcu_assign_pointer(ent->new->parent, aa_get_profile(p));
  		}

  	}

  	/* create new fs entries for introspection if needed */
  	list_for_each_entry(ent, &lh, list) {
  		if (ent->old) {
  			/* inherit old interface files */
  
  			/* if (ent->rename)
  				TODO: support rename */
  		/* } else if (ent->rename) {
  			TODO: support rename */
  		} else {
  			struct dentry *parent;
  			if (rcu_access_pointer(ent->new->parent)) {
  				struct aa_profile *p;
  				p = aa_deref_parent(ent->new);
  				parent = prof_child_dir(p);
  			} else
  				parent = ns_subprofs_dir(ent->new->ns);
  			error = __aa_fs_profile_mkdir(ent->new, parent);
  		}
  
  		if (error) {
  			info = "failed to create ";
  			goto fail_lock;
  		}
  	}
  
  	/* Done with checks that may fail - do actual replacement */

  	list_for_each_entry_safe(ent, tmp, &lh, list) {
  		list_del_init(&ent->list);
  		op = (!ent->old && !ent->rename) ? OP_PROF_LOAD : OP_PROF_REPL;

  		audit_policy(op, GFP_ATOMIC, ent->new->base.hname, NULL, error);

  
  		if (ent->old) {

  			__replace_profile(ent->old, ent->new, 1);

  			if (ent->rename) {
  				/* aafs interface uses replacedby */
  				struct aa_replacedby *r = ent->new->replacedby;
  				rcu_assign_pointer(r->profile,
  						   aa_get_profile(ent->new));

  				__replace_profile(ent->rename, ent->new, 0);

  			}

  		} else if (ent->rename) {

  			/* aafs interface uses replacedby */
  			rcu_assign_pointer(ent->new->replacedby->profile,
  					   aa_get_profile(ent->new));

  			__replace_profile(ent->rename, ent->new, 0);

  		} else if (ent->new->parent) {

  			struct aa_profile *parent, *newest;

  			parent = aa_deref_parent(ent->new);

  			newest = aa_get_newest_profile(parent);

  			/* parent replaced in this atomic set? */

  			if (newest != parent) {
  				aa_get_profile(newest);

  				rcu_assign_pointer(ent->new->parent, newest);

  				aa_put_profile(parent);

  			}

  			/* aafs interface uses replacedby */
  			rcu_assign_pointer(ent->new->replacedby->profile,
  					   aa_get_profile(ent->new));

  			__list_add_profile(&newest->base.profiles, ent->new);

  			aa_put_profile(newest);

  		} else {
  			/* aafs interface uses replacedby */
  			rcu_assign_pointer(ent->new->replacedby->profile,
  					   aa_get_profile(ent->new));

  			__list_add_profile(&ns->base.profiles, ent->new);

  		}

  		aa_load_ent_free(ent);

  	}

  	mutex_unlock(&ns->lock);

  
  out:
  	aa_put_namespace(ns);

  	if (error)
  		return error;
  	return size;

  fail_lock:

  	mutex_unlock(&ns->lock);

  	/* audit cause of failure */
  	op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
  	audit_policy(op, GFP_KERNEL, ent->new->base.hname, info, error);
  	/* audit status that rest of profiles in the atomic set failed too */
  	info = "valid profile in failed atomic policy load";
  	list_for_each_entry(tmp, &lh, list) {
  		if (tmp == ent) {
  			info = "unchecked profile in failed atomic policy load";
  			/* skip entry that caused failure */
  			continue;
  		}
  		op = (!ent->old) ? OP_PROF_LOAD : OP_PROF_REPL;
  		audit_policy(op, GFP_KERNEL, tmp->new->base.hname, info, error);
  	}
  free:

  	list_for_each_entry_safe(ent, tmp, &lh, list) {
  		list_del_init(&ent->list);
  		aa_load_ent_free(ent);
  	}

  	goto out;
  }
  
  /**
   * aa_remove_profiles - remove profile(s) from the system
   * @fqname: name of the profile or namespace to remove  (NOT NULL)
   * @size: size of the name
   *
   * Remove a profile or sub namespace from the current namespace, so that
   * they can not be found anymore and mark them as replaced by unconfined
   *
   * NOTE: removing confinement does not restore rlimits to preconfinemnet values
   *
   * Returns: size of data consume else error code if fails
   */
  ssize_t aa_remove_profiles(char *fqname, size_t size)
  {
  	struct aa_namespace *root, *ns = NULL;
  	struct aa_profile *profile = NULL;
  	const char *name = fqname, *info = NULL;
  	ssize_t error = 0;
  
  	if (*fqname == 0) {
  		info = "no profile specified";
  		error = -ENOENT;
  		goto fail;
  	}
  
  	root = aa_current_profile()->ns;
  
  	if (fqname[0] == ':') {
  		char *ns_name;
  		name = aa_split_fqname(fqname, &ns_name);

  		/* released below */
  		ns = aa_find_namespace(root, ns_name);
  		if (!ns) {
  			info = "namespace does not exist";
  			error = -ENOENT;
  			goto fail;

  		}
  	} else
  		/* released below */
  		ns = aa_get_namespace(root);

  	if (!name) {
  		/* remove namespace - can only happen if fqname[0] == ':' */

  		mutex_lock(&ns->parent->lock);

  		__remove_namespace(ns);

  		mutex_unlock(&ns->parent->lock);

  	} else {
  		/* remove profile */

  		mutex_lock(&ns->lock);

  		profile = aa_get_profile(__lookup_profile(&ns->base, name));
  		if (!profile) {
  			error = -ENOENT;
  			info = "profile does not exist";
  			goto fail_ns_lock;
  		}
  		name = profile->base.hname;
  		__remove_profile(profile);

  		mutex_unlock(&ns->lock);

  	}

  
  	/* don't fail removal if audit fails */
  	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
  	aa_put_namespace(ns);
  	aa_put_profile(profile);
  	return size;
  
  fail_ns_lock:

  	mutex_unlock(&ns->lock);

  	aa_put_namespace(ns);
  
  fail:
  	(void) audit_policy(OP_PROF_RM, GFP_KERNEL, name, info, error);
  	return error;
  }