label.c 44.2 KB
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/*
 * AppArmor security module
 *
 * This file contains AppArmor label definitions
 *
 * Copyright 2013 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.
 */

#include <linux/audit.h>
#include <linux/seq_file.h>

#include "include/apparmor.h"
#include "include/label.h"
#include "include/policy.h"
#include "include/sid.h"


/*
 * the aa_label represents the set of profiles confining an object
 *
 * Labels maintain a reference count to the set of pointers they reference
 * Labels are ref counted by
 *   tasks and object via the security field/security context off the field
 *   code - will take a ref count on a label if it needs the label
 *          beyond what is possible with an rcu_read_lock.
 *   profiles - each profile is a label
 *   sids - a pinned sid will keep a refcount of the label it is
 *          referencing
 *   objects - inode, files, sockets, ...
 *
 * Labels are not ref counted by the label set, so they maybe removed and
 * freed when no longer in use.
 *
 */

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#define REPLACEDBY_POISON 97
#define LABEL_POISON 100

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static void free_replacedby(struct aa_replacedby *r)
{
	if (r) {
		/* r->label will not updated any more as r is dead */
		aa_put_label(rcu_dereference_protected(r->label, true));
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		memset(r, 0, sizeof(*r));
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		r->label = REPLACEDBY_POISON;
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		kfree(r);
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	}
}

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

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struct aa_replacedby *aa_alloc_replacedby(struct aa_label *l)
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{
	struct aa_replacedby *r;

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	r = kzalloc(sizeof(struct aa_replacedby), GFP_KERNEL);
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	if (r) {
		kref_init(&r->count);
		rcu_assign_pointer(r->label, aa_get_label(l));
	}
	return r;
}

/* requires profile list write lock held */
void __aa_update_replacedby(struct aa_label *orig, struct aa_label *new)
{
	struct aa_label *tmp;

	AA_BUG(!orig);
	AA_BUG(!new);
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	AA_BUG(!mutex_is_locked(&labels_ns(orig)->lock));
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	tmp = rcu_dereference_protected(orig->replacedby->label,
					&labels_ns(orig)->lock);
	rcu_assign_pointer(orig->replacedby->label, aa_get_label(new));
	orig->flags |= FLAG_INVALID;
	aa_put_label(tmp);
}

/* helper fn for label_for_each_confined */
int aa_label_next_confined(struct aa_label *l, int i)
{
	AA_BUG(!l);
	AA_BUG(i < 0);

	for (; i < l->size; i++) {
		if (!profile_unconfined(l->ent[i]))
			return i;
	}

	return i;
}

#if 0
static int label_profile_pos(struct aa_label *l, struct aa_profile *profile)
{
	struct aa_profile *p;
	struct label_it i;

	AA_BUG(!profile);
	AA_BUG(!l);

	label_for_each(i, l, p) {
		if (p == profile)
			return i.i;
	}

	return -1;
}
#endif

#if 0
static bool profile_in_label(struct aa_profile *profile, struct aa_label *l)
{
	return label_profile_pos(l, profile) != -1;
}
#endif

static bool label_profiles_unconfined(struct aa_label *label)
{
	struct aa_profile *profile;
	struct label_it i;

	AA_BUG(!label);

	label_for_each(i, label, profile) {
		if (!profile_unconfined(profile))
			return false;
	}

	return true;
}

static int profile_cmp(struct aa_profile *a, struct aa_profile *b);
/**
 * aa_label_next_not_in_set - return the next profile of @sub not in @set
 * @I: label iterator
 * @set: label to test against
 * @sub: label to if is subset of @set
 *
 * Returns: profile in @sub that is not in @set, with iterator set pos after
 *     else NULL if @sub is a subset of @set
 */
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struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
					      struct aa_label *set,
					      struct aa_label *sub)
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{
	AA_BUG(!set);
	AA_BUG(!I);
	AA_BUG(I->i < 0);
	AA_BUG(I->i > set->size);
	AA_BUG(!sub);
	AA_BUG(I->j < 0);
	AA_BUG(I->j > sub->size);

	while (I->j < sub->size && I->i < set->size) {
		int res = profile_cmp(sub->ent[I->j], set->ent[I->i]);
		if (res == 0) {
			(I->j)++;
			(I->i)++;
		} else if (res > 0)
			(I->i)++;
		else
			return sub->ent[(I->j)++];
	}

	if (I->j < sub->size)
		return sub->ent[(I->j)++];

	return NULL;
}

/**
 * aa_label_is_subset - test if @sub is a subset of @set
 * @set: label to test against
 * @sub: label to test if is subset of @set
 *
 * Returns: true if @sub is subset of @set
 *     else false
 */
bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub)
{
	struct label_it i = { };

	AA_BUG(!set);
	AA_BUG(!sub);

	if (sub == set)
		return true;

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	return __aa_label_next_not_in_set(&i, set, sub) == NULL;
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}

void aa_label_destroy(struct aa_label *label)
{
	AA_BUG(!label);

	if (label_invalid(label))
		labelsetstats_dec(labels_set(label), invalid);

	if (!label_isprofile(label)) {
		struct aa_profile *profile;
		struct label_it i;

		aa_put_str(label->hname);

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		label_for_each(i, label, profile) {
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			aa_put_profile(profile);
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			label->ent[i.i] = LABEL_POISON + i.i;
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		}
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	}
	aa_free_sid(label->sid);
	aa_put_replacedby(label->replacedby);
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	label->replacedby = REPLACEDBY_POISON + 1;
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}

void aa_label_free(struct aa_label *label)
{
	if (!label)
		return;

	aa_label_destroy(label);
	labelstats_inc(freed);
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	kfree(label);
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}

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static void label_free_switch(struct aa_label *l)
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{
	if (l->flags & FLAG_NS_COUNT)
		aa_free_namespace(labels_ns(l));
	else if (label_isprofile(l))
		aa_free_profile(labels_profile(l));
	else
		aa_label_free(l);
}

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static void label_free_rcu(struct rcu_head *head)
{
	struct aa_label *l = container_of(head, struct aa_label, rcu);

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	(void) aa_label_remove(labels_set(l), l);
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	label_free_switch(l);
}

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bool aa_label_remove(struct aa_labelset *ls, struct aa_label *label);
void aa_label_kref(struct kref *kref)
{
	struct aa_label *l = container_of(kref, struct aa_label, count);
	struct aa_namespace *ns = labels_ns(l);

	if (!ns) {
		/* never live, no rcu callback needed, just using the fn */
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		label_free_switch(l);
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		return;
	}

	/* TODO: if compound label and not invalid add to reclaim cache */
	call_rcu(&l->rcu, label_free_rcu);
}

bool aa_label_init(struct aa_label *label, int size)
{
	AA_BUG(!label);
	AA_BUG(size < 1);

	label->sid = aa_alloc_sid();
	if (label->sid == AA_SID_INVALID)
		return false;

	label->size = size;			/* doesn't include null */
	label->ent[size] = NULL;		/* null terminate */
	kref_init(&label->count);
	RB_CLEAR_NODE(&label->node);

	return true;
}

/**
 * aa_label_alloc - allocate a label with a profile vector of @size length
 * @size: size of profile vector in the label
 * @gfp: memory allocation type
 *
 * Returns: new label
 *     else NULL if failed
 */
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struct aa_label *aa_label_alloc(int size, gfp_t gfp)
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{
	struct aa_label *label;

	AA_BUG(size < 1);

	/* vector: size - 2 (size of array in label struct) + 1 for null */
	label = kzalloc(sizeof(*label) + sizeof(struct aa_label *) * (size - 1),
			gfp);
	AA_DEBUG("%s (%p)\n", __func__, label);
	if (!label)
		goto fail;

	if (!aa_label_init(label, size))
		goto fail;

	labelstats_inc(allocated);

	return label;

fail:
	kfree(label);
	labelstats_inc(failed);

	return NULL;
}

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static bool __aa_label_remove(struct aa_labelset *ls, struct aa_label *label)
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{
	AA_BUG(!ls);
	AA_BUG(!label);
	AA_BUG(!write_is_locked(&ls->lock));
	AA_BUG(labels_set(label) != ls);

	if (label_invalid(label))
		labelstats_dec(invalid_intree);
	else
		__label_invalidate(label);

	if (label->flags & FLAG_IN_TREE) {
		labelsetstats_dec(ls, intree);
		rb_erase(&label->node, &ls->root);
		label->flags &= ~FLAG_IN_TREE;
		return true;
	}

	return false;
}

/**
 * aa_label_remove - remove a label from the labelset
 * @ls: set to remove the label from
 * @l: label to remove
 *
 * Returns: true if @l was removed from the tree
 *     else @l was not in tree so it could not be removed
 */
bool aa_label_remove(struct aa_labelset *ls, struct aa_label *l)
{
	unsigned long flags;
	bool res;

	write_lock_irqsave(&ls->lock, flags);
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	res = __aa_label_remove(ls, l);
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	write_unlock_irqrestore(&ls->lock, flags);

	return res;
}

/* don't use when using ptr comparisons because nodes should never be
 * the same
 */
static bool __aa_label_replace(struct aa_labelset *ls, struct aa_label *old,
			       struct aa_label *new)
{
	AA_BUG(!ls);
	AA_BUG(!old);
	AA_BUG(!new);
	AA_BUG(!write_is_locked(&ls->lock));
	AA_BUG(labels_set(old) != ls);
	AA_BUG(new->flags & FLAG_IN_TREE);

	if (label_invalid(old))
		labelstats_dec(invalid_intree);
	else
		__label_invalidate(old);

	if (old->flags & FLAG_IN_TREE) {
		rb_replace_node(&old->node, &new->node, &ls->root);
		old->flags &= ~FLAG_IN_TREE;
		new->flags |= FLAG_IN_TREE;
		return true;
	}

	return false;
}

static struct aa_label *__aa_label_insert(struct aa_labelset *ls,
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					  struct aa_label *l, bool replace);
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static struct aa_label *__aa_label_remove_and_insert(struct aa_labelset *ls,
						     struct aa_label *remove,
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						     struct aa_label *insert,
						     bool replace)
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{
	AA_BUG(!ls);
	AA_BUG(!remove);
	AA_BUG(!insert);
	AA_BUG(!write_is_locked(&ls->lock));
	AA_BUG(labels_set(remove) != ls);
	AA_BUG(insert->flags & FLAG_IN_TREE);

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	__aa_label_remove(ls, remove);
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	return __aa_label_insert(ls, insert, replace);
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}

struct aa_label *aa_label_remove_and_insert(struct aa_labelset *ls,
					    struct aa_label *remove,
					    struct aa_label *insert)
{
	unsigned long flags;
	struct aa_label *l;

	write_lock_irqsave(&ls->lock, flags);
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	l = __aa_label_remove_and_insert(ls, remove, insert, false);
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	write_unlock_irqrestore(&ls->lock, flags);

	return l;
}

/**
 * aa_label_replace - replace a label @old with a new version @new
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 * @ls: labelset being manipulated
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 * @old: label to replace
 * @new: label replacing @old
 *
 * Returns: true if @old was in tree and replaced
 *     else @old was not in tree, and @new was not inserted
 */
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bool aa_label_replace(struct aa_labelset *ls, struct aa_label *old,
		      struct aa_label *new)
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{
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	struct aa_label *l;
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	unsigned long flags;
	bool res;

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	write_lock_irqsave(&ls->lock, flags);
	l = __aa_label_remove_and_insert(ls, old, new, true);
	res = (l == new);
	write_unlock_irqrestore(&ls->lock, flags);
	aa_put_label(l);
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	return res;
}

static int ns_cmp(struct aa_namespace *a, struct aa_namespace *b)
{
	int res;

	AA_BUG(!a);
	AA_BUG(!b);
	AA_BUG(!a->base.name);
	AA_BUG(!b->base.name);

	if (a == b)
		return 0;

	res = a->level - b->level;
	if (res)
		return res;

	return strcmp(a->base.name, b->base.name);
}

/**
 * profile_cmp - profile comparision for set ordering
 * @a: profile to compare (NOT NULL)
 * @b: profile to compare (NOT NULL)
 *
 * Returns: <0  if a < b
 *          ==0 if a == b
 *          >0  if a > b
 */
static int profile_cmp(struct aa_profile *a, struct aa_profile *b)
{
	int res;

	AA_BUG(!a);
	AA_BUG(!b);
	AA_BUG(!a->ns);
	AA_BUG(!b->ns);
	AA_BUG(!a->base.hname);
	AA_BUG(!b->base.hname);

	if (a == b || a->base.hname == b->base.hname)
		return 0;
	res = ns_cmp(a->ns, b->ns);
	if (res)
		return res;

	return strcmp(a->base.hname, b->base.hname);
}

/**
 * label_vec_cmp - label comparision for set ordering
 * @a: label to compare (NOT NULL)
 * @vec: vector of profiles to compare (NOT NULL)
 * @n: length of @vec
 *
 * Returns: <0  if a < vec
 *          ==0 if a == vec
 *          >0  if a > vec
 */
static int label_vec_cmp(struct aa_label *a, struct aa_profile **vec, int n)
{
	int i;

	AA_BUG(!a);
	AA_BUG(!vec);
	AA_BUG(!*vec);
	AA_BUG(n <= 0);

	for (i = 0; i < a->size && i < n; i++) {
		int res = profile_cmp(a->ent[i], vec[i]);
		if (res != 0)
			return res;
	}

	return a->size - n;
}

/**
 * label_cmp - label comparision for set ordering
 * @a: label to compare (NOT NULL)
 * @b: label to compare (NOT NULL)
 *
 * Returns: <0  if a < b
 *          ==0 if a == b
 *          >0  if a > b
 */
static int label_cmp(struct aa_label *a, struct aa_label *b)
{
	AA_BUG(!b);

	if (a == b)
		return 0;

	return label_vec_cmp(a, b->ent, b->size);
}

/**
 * __aa_label_vec_find - find label that matches @vec in label set
 * @ls: set of labels to search (NOT NULL)
 * @vec: vec of profiles to find matching label for (NOT NULL)
 * @n: length of @vec
 *
 * Requires: @ls lock held
 *           caller to hold a valid ref on l
 *
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 * Returns: ref counted @label if matching label is in tree
 *          ref counted label that is equiv to @l in tree
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 *     else NULL if @vec equiv is not in tree
 */
static struct aa_label *__aa_label_vec_find(struct aa_labelset *ls,
					    struct aa_profile **vec, int n)
{
	struct rb_node *node;

	AA_BUG(!ls);
	AA_BUG(!vec);
	AA_BUG(!*vec);
	AA_BUG(n <= 0);

	node = ls->root.rb_node;
	while (node) {
		struct aa_label *this = rb_entry(node, struct aa_label, node);
		int result = label_vec_cmp(this, vec, n);

		if (result > 0)
			node = node->rb_left;
		else if (result < 0)
			node = node->rb_right;
		else
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			return aa_get_label_not0(this);
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	}

	return NULL;
}

/**
 * __aa_label_find - find label @l in label set
 * @ls: set of labels to search (NOT NULL)
 * @l: label to find (NOT NULL)
 *
 * Requires: @ls lock held
 *           caller to hold a valid ref on l
 *
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 * Returns: ref counted @l if @l is in tree OR
 *          ref counted label that is equiv to @l in tree
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 *     else NULL if @l or equiv is not in tree
 */
static struct aa_label *__aa_label_find(struct aa_labelset *ls,
					struct aa_label *l)
{
	AA_BUG(!l);

	return __aa_label_vec_find(ls, l->ent, l->size);
}

/**
 * aa_label_vec_find - find label @l in label set
 * @ls: set of labels to search (NOT NULL)
 * @vec: array of profiles to find equiv label for (NOT NULL)
 * @n: length of @vec
 *
 * Returns: refcounted label if @vec equiv is in tree
 *     else NULL if @vec equiv is not in tree
 */
struct aa_label *aa_label_vec_find(struct aa_labelset *ls,
				   struct aa_profile **vec,
				   int n)
{
	struct aa_label *label;
	unsigned long flags;

	AA_BUG(!ls);
	AA_BUG(!vec);
	AA_BUG(!*vec);
	AA_BUG(n <= 0);

	read_lock_irqsave(&ls->lock, flags);
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	label = __aa_label_vec_find(ls, vec, n);
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	labelstats_inc(sread);
	read_unlock_irqrestore(&ls->lock, flags);

	return label;
}

/**
 * aa_label_find - find label @l in label set
 * @ls: set of labels to search (NOT NULL)
 * @l: label to find (NOT NULL)
 *
 * Requires: caller to hold a valid ref on l
 *
 * Returns: refcounted @l if @l is in tree
 *          refcounted label that is equiv to @l in tree
 *     else NULL if @l or equiv is not in tree
 */
struct aa_label *aa_label_find(struct aa_labelset *ls, struct aa_label *l)
{
	AA_BUG(!l);

	return aa_label_vec_find(ls, l->ent, l->size);
}

/**
 * __aa_label_insert - attempt to insert @l into a label set
 * @ls: set of labels to insert @l into (NOT NULL)
 * @l: new label to insert (NOT NULL)
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 * @replace: whether this insertion should replace an existing entry if present
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 * Requires: @ls->lock
 *           caller to hold a valid ref on l
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 *           if @replace is true l has a preallocated replacedby associated
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 * Returns: @l if successful in inserting @l - with additional refcount
 *          else ref counted equivalent label that is already in the set,
            the else condition only happens if @replace is false
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 */
static struct aa_label *__aa_label_insert(struct aa_labelset *ls,
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					  struct aa_label *l, bool replace)
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{
	struct rb_node **new, *parent = NULL;

	AA_BUG(!ls);
	AA_BUG(!l);
	AA_BUG(!write_is_locked(&ls->lock));
	AA_BUG(l->flags & FLAG_IN_TREE);

	/* Figure out where to put new node */
	new = &ls->root.rb_node;
	while (*new) {
		struct aa_label *this = rb_entry(*new, struct aa_label, node);
		int result = label_cmp(l, this);

		parent = *new;
		if (result == 0) {
			labelsetstats_inc(ls, existing);
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			if (!replace) {
				if (aa_get_label_not0(this))
					return this;
				/* queued for destruction, in place replace */
			} else {
				if (this->replacedby) {
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					free_replacedby(l->replacedby);
					l->replacedby = aa_get_replacedby(this->replacedby);
					__aa_update_replacedby(this, l);
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				} else
					this->replacedby = aa_get_replacedby(l->replacedby);
			}
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			AA_BUG(!__aa_label_replace(ls, this, l));
			return aa_get_label(l);
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		} else if (result < 0)
			new = &((*new)->rb_left);
		else /* (result > 0) */
			new = &((*new)->rb_right);
	}

	/* Add new node and rebalance tree. */
	rb_link_node(&l->node, parent, new);
	rb_insert_color(&l->node, &ls->root);
	l->flags |= FLAG_IN_TREE;
	labelsetstats_inc(ls, insert);
	labelsetstats_inc(ls, intree);

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	return aa_get_label(l);
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}

/**
 * aa_label_insert - insert label @l into @ls or return existing label
 * @ls - labelset to insert @l into
 * @l - label to insert
 *
 * Requires: caller to hold a valid ref on l
 *
 * Returns: ref counted @l if successful in inserting @l
 *     else ref counted equivalent label that is already in the set
 */
struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l)
{
	struct aa_label *label;
	unsigned long flags;

	AA_BUG(!ls);
	AA_BUG(!l);

	/* check if label exists before taking lock */
	if (!label_invalid(l)) {
		read_lock_irqsave(&ls->lock, flags);
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		label = __aa_label_find(ls, l);
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		read_unlock_irqrestore(&ls->lock, flags);
		labelstats_inc(fread);
		if (label)
			return label;
	}

	write_lock_irqsave(&ls->lock, flags);
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	label = __aa_label_insert(ls, l, false);
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	write_unlock_irqrestore(&ls->lock, flags);

	return label;
}

748
struct aa_label *aa_label_vec_find_or_create(struct aa_labelset *ls,
749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911
					     struct aa_profile **vec, int len)
{
	struct aa_label *label = aa_label_vec_find(ls, vec, len);
	if (label)
		return label;

	return aa_label_vec_merge(vec, len, GFP_KERNEL);
}

/**
 * aa_label_next_in_merge - find the next profile when merging @a and @b
 * @I: label iterator
 * @a: label to merge
 * @b: label to merge
 *
 * Returns: next profile
 *     else null if no more profiles
 */
struct aa_profile *aa_label_next_in_merge(struct label_it *I,
					  struct aa_label *a,
					  struct aa_label *b)
{
	AA_BUG(!a);
	AA_BUG(!b);
	AA_BUG(!I);
	AA_BUG(I->i < 0);
	AA_BUG(I->i > a->size);
	AA_BUG(I->j < 0);
	AA_BUG(I->j > b->size);

	if (I->i < a->size) {
		if (I->j < b->size) {
			int res = profile_cmp(a->ent[I->i], b->ent[I->j]);
			if (res > 0)
				return b->ent[(I->j)++];
			if (res == 0)
				(I->j)++;
		}

		return a->ent[(I->i)++];
	}

	if (I->j < b->size)
		return b->ent[(I->j)++];

	return NULL;
}

/**
 * label_merge_cmp - cmp of @a merging with @b against @z for set ordering
 * @a: label to merge then compare (NOT NULL)
 * @b: label to merge then compare (NOT NULL)
 * @z: label to compare merge against (NOT NULL)
 *
 * Assumes: using the most recent versions of @a, @b, and @z
 *
 * Returns: <0  if a < b
 *          ==0 if a == b
 *          >0  if a > b
 */
static int label_merge_cmp(struct aa_label *a, struct aa_label *b,
                           struct aa_label *z)
{
	struct aa_profile *p = NULL;
	struct label_it i = { };
	int k;

	AA_BUG(!a);
	AA_BUG(!b);
	AA_BUG(!z);

	for (k = 0;
	     k < z->size && (p = aa_label_next_in_merge(&i, a, b));
	     k++) {
		int res = profile_cmp(p, z->ent[k]);

		if (res != 0)
			return res;
	}

	if (p)
		return 1;
	else if (k < z->size)
		return -1;
	return 0;
}

#if 0
/**
 * label_merge_len - find the length of the merge of @a and @b
 * @a: label to merge (NOT NULL)
 * @b: label to merge (NOT NULL)
 *
 * Assumes: using newest versions of labels @a and @b
 *
 * Returns: length of a label vector for merge of @a and @b
 */
static int label_merge_len(struct aa_label *a, struct aa_label *b)
{
	int len = a->size + b->size;
	int i, j;

	AA_BUG(!a);
	AA_BUG(!b);

	/* find entries in common and remove from count */
	for (i = j = 0; i < a->size && j < b->size; ) {
		int res = profile_cmp(a->ent[i], b->ent[j]);
		if (res == 0) {
			len--;
			i++;
			j++;
		} else if (res < 0)
			i++;
		else
			j++;
	}

	return len;
}
#endif

/**
 * aa_sort_and_merge_profiles - canonical sort and merge a list of profiles
 * @n: number of refcounted profiles in the list (@n > 0)
 * @ps: list of profiles to sort and merge
 *
 * Returns: the number of duplicates eliminated == references put
 */
static int aa_sort_and_merge_profiles(int n, struct aa_profile **ps)
{
	int i, dups = 0;

	AA_BUG(n < 1);
	AA_BUG(!ps);

	/* label lists are usually small so just use insertion sort */
	for (i = 1; i < n; i++) {
		struct aa_profile *tmp = ps[i];
		int pos, j;

		for (pos = i - 1 - dups; pos >= 0; pos--) {
			int res = profile_cmp(ps[pos], tmp);
			if (res == 0) {
				aa_put_profile(tmp);
				dups++;
				goto continue_outer;
			} else if (res < 0)
				break;
		}
		pos++;

		for (j = i - dups; j > pos; j--)
			ps[j] = ps[j - 1];
		ps[pos] = tmp;
	continue_outer:
		; /* sigh empty statement required after the label */
	}

	return dups;
}

/**
912
 * __label_merge_insert - create a new label by merging @a and @b
913 914 915 916
 * @l: preallocated label to merge into (NOT NULL)
 * @a: label to merge with @b  (NOT NULL)
 * @b: label to merge with @a  (NOT NULL)
 *
917 918
 * Requires: preallocated replacedby
 *
919 920 921 922 923 924 925 926 927
 * Returns: ref counted label either l if merge is unique
 *          a if b is a subset of a
 *          b if a is a subset of b
 *
 * NOTE: will not use l if the merge results in l == a or b
 *
 *       Must be used within labelset write lock to avoid racing with
 *       label invalidation.
 */
928 929 930 931
static struct aa_label *__label_merge_insert(struct aa_labelset *ls,
					     struct aa_label *l,
					     struct aa_label *a,
					     struct aa_label *b)
932 933 934 935
{
	struct aa_profile *next;
	struct label_it i;
	int k = 0, invcount = 0;
936
	bool stale = false;
937 938 939 940 941 942 943 944

	AA_BUG(!a);
	AA_BUG(a->size < 0);
	AA_BUG(!b);
	AA_BUG(b->size < 0);
	AA_BUG(!l);
	AA_BUG(l->size < a->size + b->size);

945 946 947
	if (a == b)
		return aa_get_label(a);

948 949 950 951 952 953 954
	label_for_each_in_merge(i, a, b, next) {
		if (PROFILE_INVALID(next)) {
			l->ent[k] = aa_get_newest_profile(next);
			if (next->label.replacedby !=
			    l->ent[k]->label.replacedby)
				invcount++;
			k++;
955
			stale = true;
956 957 958 959 960 961 962 963 964
		} else
			l->ent[k++] = aa_get_profile(next);
	}
	/* set to actual size which is <= allocated len */
	l->size = k;
	l->ent[k] = NULL;

	if (invcount) {
		l->size -= aa_sort_and_merge_profiles(l->size, &l->ent[0]);
965 966 967
	} else if (!stale) {
		/* merge could be same as a || b, note: it is not possible
		 * for l->size == a->size == b->size unless a == b */
968 969 970 971 972
		if (k == a->size)
			return aa_get_label(a);
		else if (k == b->size)
			return aa_get_label(b);
	}
973 974
	if (label_profiles_unconfined(l))
		l->flags |= FLAG_UNCONFINED;
975
	return __aa_label_insert(ls, l, true);
976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002
}

/**
 * labelset_of_merge - find into which labelset a merged label should be inserted
 * @a: label to merge and insert
 * @b: label to merge and insert
 *
 * Returns: labelset that the merged label should be inserted into
 */
static struct aa_labelset *labelset_of_merge(struct aa_label *a, struct aa_label *b)
{
	struct aa_namespace *nsa = labels_ns(a);
	struct aa_namespace *nsb = labels_ns(b);

	if (ns_cmp(nsa, nsb) <= 0)
		return &nsa->labels;
	return &nsb->labels;
}

/**
 * __aa_label_find_merge - find label that is equiv to merge of @a and @b
 * @ls: set of labels to search (NOT NULL)
 * @a: label to merge with @b  (NOT NULL)
 * @b: label to merge with @a  (NOT NULL)
 *
 * Requires: read_lock held
 *
1003
 * Returns: ref counted label that is equiv to merge of @a and @b
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029
 *     else NULL if merge of @a and @b is not in set
 */
static struct aa_label *__aa_label_find_merge(struct aa_labelset *ls,
					      struct aa_label *a,
					      struct aa_label *b)
{
	struct rb_node *node;

	AA_BUG(!ls);
	AA_BUG(!a);
	AA_BUG(!b);

	if (a == b)
		return __aa_label_find(ls, a);

	node  = ls->root.rb_node;
	while (node) {
		struct aa_label *this = container_of(node, struct aa_label,
						     node);
		int result = label_merge_cmp(a, b, this);

		if (result < 0)
			node = node->rb_left;
		else if (result > 0)
			node = node->rb_right;
		else
1030
			return aa_get_label_not0(this);
1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
	}

	return NULL;
}


/**
 * __aa_label_find_merge - find label that is equiv to merge of @a and @b
 * @a: label to merge with @b  (NOT NULL)
 * @b: label to merge with @a  (NOT NULL)
 *
 * Requires: labels be fully constructed with a valid ns
 *
 * Returns: ref counted label that is equiv to merge of @a and @b
 *     else NULL if merge of @a and @b is not in set
 */
struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b)
{
	struct aa_labelset *ls;
	struct aa_label *label, *ar = NULL, *br = NULL;
	unsigned long flags;

	AA_BUG(!a);
	AA_BUG(!b);

	ls = labelset_of_merge(a, b);
	read_lock_irqsave(&ls->lock, flags);
	if (label_invalid(a))
		a = ar = aa_get_newest_label(a);
	if (label_invalid(b))
		b = br = aa_get_newest_label(b);
1062
	label = __aa_label_find_merge(ls, a, b);
1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106
	read_unlock_irqrestore(&ls->lock, flags);
	aa_put_label(ar);
	aa_put_label(br);
	labelsetstats_inc(ls, msread);

	return label;
}

/**
 * aa_label_merge - attempt to insert new merged label of @a and @b
 * @ls: set of labels to insert label into (NOT NULL)
 * @a: label to merge with @b  (NOT NULL)
 * @b: label to merge with @a  (NOT NULL)
 * @gfp: memory allocation type
 *
 * Requires: caller to hold valid refs on @a and @b
 *           labels be fully constructed with a valid ns
 *
 * Returns: ref counted new label if successful in inserting merge of a & b
 *     else ref counted equivalent label that is already in the set.
 *     else NULL if could not create label (-ENOMEM)
 */
struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
				gfp_t gfp)
{
	struct aa_label *label = NULL;
	struct aa_labelset *ls;
	unsigned long flags;

	AA_BUG(!a);
	AA_BUG(!b);

	if (a == b)
		return aa_get_newest_label(a);

	ls = labelset_of_merge(a, b);

	/* TODO: enable when read side is lockless
	 * check if label exists before taking locks
	if (!label_invalid(a) && !label_invalid(b))
		label = aa_label_find_merge(a, b);
	*/

	if (!label) {
1107
		struct aa_label *new;
1108
		struct aa_replacedby *r;
1109 1110 1111 1112 1113 1114 1115

		a = aa_get_newest_label(a);
		b = aa_get_newest_label(b);

		/* could use label_merge_len(a, b), but requires double
		 * comparison for small savings
		 */
1116
		new = aa_label_alloc(a->size + b->size, gfp);
1117
		if (!new)
1118
			goto out;
1119
		r = aa_alloc_replacedby(new);
1120 1121 1122 1123 1124 1125
		if (!r) {
			aa_label_free(new);
			goto out;
		}
		/* only label update will set replacedby so ns lock is enough */
		new->replacedby = r;
1126
		write_lock_irqsave(&ls->lock, flags);
1127 1128
		label = __label_merge_insert(ls, new, a, b);
		write_unlock_irqrestore(&ls->lock, flags);
1129 1130 1131 1132 1133
		if (label != new) {
			/* new may not be fully setup so no put_label */
			aa_label_free(new);
			new = NULL;
		}
1134
		aa_put_label(new);
1135
	out:
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
		aa_put_label(a);
		aa_put_label(b);
	}

	return label;
}

/* requires sort and merge done first */
struct aa_label *aa_label_vec_merge(struct aa_profile **vec, int len,
				    gfp_t gfp)
{
	struct aa_label *label = NULL;
	struct aa_labelset *ls;
	unsigned long flags;
	struct aa_label *new;
	int i;

	AA_BUG(!vec);

	if (len == 1)
		return aa_get_label(&vec[0]->label);

	ls = labels_set(&vec[len - 1]->label);

	/* TODO: enable when read side is lockless
	 * check if label exists before taking locks
	 */
1163
	new = aa_label_alloc(len, gfp);
1164 1165 1166 1167 1168 1169
	if (!new)
		return NULL;

	for (i = 0; i < len; i++) {
		new->ent[i] = aa_get_profile(vec[i]);
	}
1170 1171
	write_lock_irqsave(&ls->lock, flags);
	label = __aa_label_insert(ls, new, false);
1172
	write_unlock_irqrestore(&ls->lock, flags);
1173 1174 1175 1176 1177 1178
	if (label != new)
		/* not fully constructed don't put */
		aa_label_free(new);
	else
		/* extra ref */
		aa_put_label(new);
1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247

	return label;
}

/**
 * aa_update_label_name - update a label to have a stored name
 * @ns: ns being viewed from (NOT NULL)
 * @label: label to update (NOT NULL)
 * @gfp: type of memory allocation
 *
 * Requires: labels_set(label) not locked in caller
 *
 * note: only updates the label name if it does not have a name already
 *       and if it is in the labelset
 */
bool aa_update_label_name(struct aa_namespace *ns, struct aa_label *label,
			  gfp_t gfp)
{
	struct aa_labelset *ls;
	unsigned long flags;
	char __counted *name;
	bool res = false;

	AA_BUG(!ns);
	AA_BUG(!label);

	if (label->hname || labels_ns(label) != ns)
		return res;

	if (aa_label_acntsprint(&name, ns, label, false, gfp) == -1)
		return res;

	ls = labels_set(label);
	write_lock_irqsave(&ls->lock, flags);
	if (!label->hname && label->flags & FLAG_IN_TREE) {
		label->hname = name;
		res = true;
	} else
		aa_put_str(name);
	write_unlock_irqrestore(&ls->lock, flags);

	return res;
}

/* cached label name is present and visible
 * @label->hname only exists if label is namespace hierachical */
static inline bool label_name_visible(struct aa_namespace *ns,
				      struct aa_label *label)
{
	if (label->hname && labels_ns(label) == ns)
		return true;

	return false;
}

/* helper macro for snprint routines */
#define update_for_len(total, len, size, str)	\
do {					\
	AA_BUG(len < 0);		\
	total += len;			\
	len = min(len, size);		\
	size -= len;			\
	str += len;			\
} while (0)

/**
 * aa_modename_snprint - print the mode name of a profile or label to a buffer
 * @str: buffer to write to (MAY BE NULL if @size == 0)
 * @size: size of buffer
1248
 * @ns: namespace profile is being viewed from
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
 * @label: label to print the mode of (NOT NULL)
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 *
 * Note: will print every mode name visible (mode1)(mode2)(mode3)
 *       this is likely not what is desired for most interfaces
 *       use aa_mode_snprint to get the standard mode format
 */
static int aa_modename_snprint(char *str, size_t size, struct aa_namespace *ns,
			       struct aa_label *label)
{
	struct aa_profile *profile;
	struct label_it i;
	int total = 0;
	size_t len;

1266 1267 1268
	if (!ns)
		ns = labels_ns(label);

1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288
	label_for_each(i, label, profile) {
		const char *modestr;
		if (!aa_ns_visible(ns, profile->ns))
			continue;
		/* no mode for 'unconfined' */
		if (profile_unconfined(profile) &&
		    profile == profile->ns->unconfined)
			break;
		modestr = aa_profile_mode_names[profile->mode];
		len = snprintf(str, size, "(%s)", modestr);
		update_for_len(total, len, size, str);
	}

	return total;
}

/**
 * aa_modechr_snprint - print the mode chr of a profile or labels to a buffer
 * @str: buffer to write to (MAY BE NULL if @size == 0)
 * @size: size of buffer
1289
 * @ns: namespace profile is being viewed from
1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306
 * @label: label to print the mode chr of (NOT NULL)
 *
 * Returns: size of mode string written or would be written if larger than
 *          available buffer
 *
 * Note: will print the chr of every visible profile (123)
 *       this is likely not what is desired for most interfaces
 *       use aa_mode_snprint to get the standard mode format
 */
static int aa_modechr_snprint(char *str, size_t size, struct aa_namespace *ns,
			      struct aa_label *label)
{
	struct aa_profile *profile;
	struct label_it i;
	int total = 0;
	size_t len;

1307 1308 1309
	if (!ns)
		ns = labels_ns(label);

1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
	len = snprintf(str, size, "(");
	update_for_len(total, len, size, str);
	label_for_each(i, label, profile) {
		const char *modestr;
		if (!aa_ns_visible(ns, profile->ns))
			continue;
		modestr = aa_profile_mode_names[profile->mode];
		/* just the first char of the modestr */
		len = snprintf(str, size, "%c", *modestr);
		update_for_len(total, len, size, str);
	}
	len = snprintf(str, size, ")");
	update_for_len(total, len, size, str);

	return total;
}

/**
 * aa_mode_snprint - print the mode of a profile or label to a buffer
 * @str: buffer to write to (MAY BE NULL if @size == 0)
 * @size: size of buffer
1331
 * @ns: namespace profile is being viewed from
1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347
 * @label: label to print the mode of (NOT NULL)
 * @count: number of label entries to be printed (<= 0 if unknown)
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 *
 * Note: dynamically switches between mode name, and mode char format as
 *       appropriate
 *       will not print anything if the label is not visible
 */
static int aa_mode_snprint(char *str, size_t size, struct aa_namespace *ns,
			   struct aa_label *label, int count)
{
	struct aa_profile *profile;
	struct label_it i;

1348 1349 1350
	if (!ns)
		ns = labels_ns(label);

1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371
	if (count <= 0) {
		count = 0;
		label_for_each(i, label, profile) {
			if (aa_ns_visible(ns, profile->ns))
				count++;
		}
	}

	if (count == 0)
		return 0;

	if (count == 1)
		return aa_modename_snprint(str, size, ns, label);

	return aa_modechr_snprint(str, size, ns, label);
}

/**
 * aa_snprint_profile - print a profile name to a buffer
 * @str: buffer to write to. (MAY BE NULL if @size == 0)
 * @size: size of buffer
1372
 * @ns: namespace profile is being viewed from
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383
 * @profile: profile to view (NOT NULL)
 * @mode: whether to include the mode string
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 *
 * Note: will not print anything if the profile is not visible
 */
int aa_profile_snprint(char *str, size_t size, struct aa_namespace *ns,
		       struct aa_profile *profile, bool mode)
{
1384
	const char *ns_name;
1385 1386 1387 1388

	AA_BUG(!str && size != 0);
	AA_BUG(!profile);

1389 1390 1391 1392
	if (!ns)
		ns = profiles_ns(profile);

	ns_name = aa_ns_name(ns, profile->ns);
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414
	if (!ns_name)
		return 0;

	if (mode && profile != profile->ns->unconfined) {
		const char *modestr = aa_profile_mode_names[profile->mode];
		if (strlen(ns_name))
			return snprintf(str, size, ":%s://%s (%s)", ns_name,
					profile->base.hname, modestr);
		return snprintf(str, size, "%s (%s)", profile->base.hname,
				modestr);
	}

	if (strlen(ns_name))
		return snprintf(str, size, ":%s://%s", ns_name,
				profile->base.hname);
	return snprintf(str, size, "%s", profile->base.hname);
}

/**
 * aa_label_snprint - print a label name to a string buffer
 * @str: buffer to write to. (MAY BE NULL if @size == 0)
 * @size: size of buffer
1415
 * @ns: namespace profile is being viewed from
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438
 * @label: label to view (NOT NULL)
 * @mode: whether to include the mode string
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 *
 * Note: labels do not have to be strictly hierarchical to the ns as
 *       objects may be shared across different namespaces and thus
 *       pickup labeling from each ns.  If a particular part of the
 *       label is not visible it will just be excluded.  And if none
 *       of the label is visible "---" will be used.
 */
int aa_label_snprint(char *str, size_t size, struct aa_namespace *ns,
		     struct aa_label *label, bool mode)
{
	struct aa_profile *profile;
	struct label_it i;
	int count = 0, total = 0;
	size_t len;

	AA_BUG(!str && size != 0);
	AA_BUG(!label);

1439 1440 1441
	if (!ns)
		ns = labels_ns(label);

1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
	label_for_each(i, label, profile) {
		if (aa_ns_visible(ns, profile->ns)) {
			if (count > 0) {
				len = snprintf(str, size, "//&");
				update_for_len(total, len, size, str);
			}
			len = aa_profile_snprint(str, size, ns, profile, false);
			update_for_len(total, len, size, str);
			count++;
		}
	}

	if (count == 0)
		return snprintf(str, size, aa_hidden_ns_name);

	/* count == 1 && ... is for backwards compat where the mode
	 * is not displayed for 'unconfined' in the current ns
	 */
	if (mode &&
	    !(count == 1 && labels_ns(label) == ns &&
	      labels_profile(label) == ns->unconfined)) {
		len = snprintf(str, size, " ");
		update_for_len(total, len, size, str);
		len = aa_mode_snprint(str, size, ns, label, count);
		update_for_len(total, len, size, str);
	}

	return total;
}
#undef update_for_len

/**
 * aa_label_asprint - allocate a string buffer and print label into it
 * @strp: Returns - the allocated buffer with the label name. (NOT NULL)
1476
 * @ns: namespace profile is being viewed from
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504
 * @label: label to view (NOT NULL)
 * @mode: whether to include the mode string
 * @gfp: kernel memory allocation type
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 */
int aa_label_asprint(char **strp, struct aa_namespace *ns,
		     struct aa_label *label, bool mode, gfp_t gfp)
{
	int size;

	AA_BUG(!strp);
	AA_BUG(!label);

	size = aa_label_snprint(NULL, 0, ns, label, mode);
	if (size < 0)
		return size;

	*strp = kmalloc(size + 1, gfp);
	if (!*strp)
		return -ENOMEM;
	return aa_label_snprint(*strp, size + 1, ns, label, mode);
}

/**
 * aa_label_acntsprint - allocate a __counted string buffer and print label
 * @strp: buffer to write to. (MAY BE NULL if @size == 0)
1505
 * @ns: namespace profile is being viewed from
1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
 * @label: label to view (NOT NULL)
 * @mode: whether to include the mode string
 * @gfp: kernel memory allocation type
 *
 * Returns: size of name written or would be written if larger than
 *          available buffer
 */
int aa_label_acntsprint(char __counted **strp, struct aa_namespace *ns,
			struct aa_label *label, bool mode, gfp_t gfp)
{
	int size;

	AA_BUG(!strp);
	AA_BUG(!label);

	size = aa_label_snprint(NULL, 0, ns, label, mode);
	if (size < 0)
		return size;

	*strp = aa_str_alloc(size + 1, gfp);
	if (!*strp)
		return -ENOMEM;
	return aa_label_snprint(*strp, size + 1, ns, label, mode);
}


void aa_label_audit(struct audit_buffer *ab, struct aa_namespace *ns,
		    struct aa_label *label, bool mode, gfp_t gfp)
{
	const char *str;
	char *name = NULL;
	int len;

	AA_BUG(!ab);
	AA_BUG(!label);

1542 1543 1544
	if (!ns)
		ns = labels_ns(label);

1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
	if (label_name_visible(ns, label)) {
		str = (char *) label->hname;
		len = strlen(str);
	} else {
		labelstats_inc(audit_name_alloc);
		len  = aa_label_asprint(&name, ns, label, mode, gfp);
		if (len == -1) {
			labelstats_inc(audit_name_fail);
			AA_DEBUG("label print error");
			return;
		}
		str = name;
	}

	if (audit_string_contains_control(str, len))
		audit_log_n_hex(ab, str, len);
	else
		audit_log_n_string(ab, str, len);

	kfree(name);
}

void aa_label_seq_print(struct seq_file *f, struct aa_namespace *ns,
			struct aa_label *label, bool mode, gfp_t gfp)
{
	AA_BUG(!f);
	AA_BUG(!label);

1573 1574 1575
	if (!ns)
		ns = labels_ns(label);

1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600
	if (!label_name_visible(ns, label)) {
		char *str;
		int len;

		labelstats_inc(seq_print_name_alloc);
		len = aa_label_asprint(&str, ns, label, mode, gfp);
		if (len == -1) {
			labelstats_inc(seq_print_name_fail);
			AA_DEBUG("label print error");
			return;
		}
		seq_printf(f, "%s", str);
		kfree(str);
	} else
		seq_printf(f, "%s", label->hname);
}

void aa_label_printk(struct aa_namespace *ns, struct aa_label *label, bool mode,
		     gfp_t gfp)
{
	char *str;
	int len;

	AA_BUG(!label);

1601 1602 1603
	if (!ns)
		ns = labels_ns(label);

1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
	if (!label_name_visible(ns, label)) {
		labelstats_inc(printk_name_alloc);
		len = aa_label_asprint(&str, ns, label, mode, gfp);
		if (len == -1) {
			labelstats_inc(printk_name_fail);
			AA_DEBUG("label print error");
			return;
		}
		printk("%s", str);
		kfree(str);
	} else
		printk("%s", label->hname);
}

static int label_count_str_entries(const char *str)
{
	const char *split;
	int count = 1;

	AA_BUG(!str);

	for (split = strstr(str, "//&"); split; split = strstr(str, "//&")) {
		count++;
		str = split + 3;
	}

	return count;
}

/**
 * aa_label_parse - parse, validate and convert a text string to a label
 * @base: base label to use for lookups (NOT NULL)
 * @str: null terminated text string (NOT NULL)
 * @gfp: allocation type
 * @create: true if should create compound labels if they don't exist
 *
 * Returns: the matching refcounted label if present
 *     else ERRPTR
 */
struct aa_label *aa_label_parse(struct aa_label *base, char *str, gfp_t gfp,
				bool create)
{
	DEFINE_PROFILE_VEC(vec, tmp);
	struct aa_label *l;
	int i, len, error;
	char *split;

	AA_BUG(!base);
	AA_BUG(!str);

	len = label_count_str_entries(str);
	error = aa_setup_profile_vec(vec, tmp, len);
	if (error)
		return ERR_PTR(error);

	for (split = strstr(str, "//&"), i = 0; split && i < len; i++) {
		vec[i] = aa_fqlookupn_profile(base, str, split - str);
		if (!vec[i])
			goto fail;
		str = split + 3;
		split = strstr(str, "//&");
	}
	vec[i] = aa_fqlookupn_profile(base, str, strlen(str));
	if (!vec[i])
		goto fail;
	if (len == 1)
		/* no need to free vec as len < LOCAL_VEC_ENTRIES */
		return &vec[0]->label;

	i = aa_sort_and_merge_profiles(len, vec);
	len -= i;

	if (create)
		l = aa_label_vec_find_or_create(labels_set(base), vec, len);
	else
		l = aa_label_vec_find(labels_set(base), vec, len);
	if (!l)
		l = ERR_PTR(-ENOENT);

out:
	/* use adjusted len from after sort_and_merge, not original */
	aa_cleanup_profile_vec(vec, tmp, len);
	return l;

fail:
	l = ERR_PTR(-ENOENT);
	goto out;
}


/**
 * aa_labelset_destroy - remove all labels from the label set
 * @ls: label set to cleanup (NOT NULL)
 *
 * Labels that are removed from the set may still exist beyond the set
 * being destroyed depending on their reference counting
 */
void aa_labelset_destroy(struct aa_labelset *ls)
{
	struct rb_node *node;
	unsigned long flags;

	AA_BUG(!ls);

	write_lock_irqsave(&ls->lock, flags);
	for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) {
		struct aa_label *this = rb_entry(node, struct aa_label, node);
1711
		__aa_label_remove(ls, this);
1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727
	}
	write_unlock_irqrestore(&ls->lock, flags);
}

/*
 * @ls: labelset to init (NOT NULL)
 */
void aa_labelset_init(struct aa_labelset *ls)
{
	AA_BUG(!ls);

	rwlock_init(&ls->lock);
	ls->root = RB_ROOT;
	labelstats_init(&ls);
}

1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
static bool vec_invalid(struct aa_profile **vec, int n)
{
	int i;

	for (i = 0; i < n; i++) {
		if (PROFILE_INVALID(vec[i]))
			return true;
	}

	return false;
}

1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
static struct aa_label *labelset_next_invalid(struct aa_labelset *ls)
{
	struct aa_label *label;
	struct rb_node *node;
	unsigned long flags;

	AA_BUG(!ls);

	read_lock_irqsave(&ls->lock, flags);

	__labelset_for_each(ls, node) {
1751 1752 1753
		struct aa_profile *p;
		struct label_it i;

1754
		label = rb_entry(node, struct aa_label, node);
1755 1756
		if ((label_invalid(label) || vec_invalid(label->ent, label->size)) &&
		    aa_get_label_not0(label))
1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791
			goto out;

	}
	label = NULL;

out:
	read_unlock_irqrestore(&ls->lock, flags);

	return label;
}

/**
 * __label_update - insert updated version of @label into labelset
 * @label - the label to update/repace
 *
 * Returns: new label that is up to date
 *     else NULL on failure
 *
 * Requires: @ns lock be held
 *
 * Note: worst case is the stale @label does not get updated and has
 *       to be updated at a later time.
 */
static struct aa_label *__label_update(struct aa_label *label)
{
	struct aa_label *l, *tmp;
	struct aa_labelset *ls;
	struct aa_profile *p;
	struct label_it i;
	unsigned long flags;
	int invcount = 0;

	AA_BUG(!label);
	AA_BUG(!mutex_is_locked(&labels_ns(label)->lock));

1792
	l = aa_label_alloc(label->size, GFP_KERNEL);
1793 1794 1795
	if (!l)
		return NULL;

1796
	if (!label->replacedby) {
1797
		struct aa_replacedby *r = aa_alloc_replacedby(l);
1798 1799 1800 1801 1802 1803 1804 1805
		if (!r) {
			aa_put_label(l);
			return NULL;
		}
		/* only label update will set replacedby so ns lock is enough */
		label->replacedby = r;
	}

1806 1807 1808
	/* while holding the ns_lock will stop profile replacement, removal,
	 * and label updates, label merging and removal can be occuring
	 */
1809

1810 1811
	ls = labels_set(label);
	write_lock_irqsave(&ls->lock, flags);
1812 1813 1814 1815
	/* circular ref only broken by replace or remove */
	l->replacedby = aa_get_replacedby(label->replacedby);
	__aa_update_replacedby(label, l);

1816 1817 1818 1819 1820 1821 1822 1823 1824
	label_for_each(i, label, p) {
		l->ent[i.i] = aa_get_newest_profile(p);
		if (&l->ent[i.i]->label.replacedby != &p->label.replacedby)
			invcount++;
	}

	/* updated label invalidated by being removed/renamed from labelset */
	if (invcount) {
		l->size -= aa_sort_and_merge_profiles(l->size, &l->ent[0]);
1825 1826 1827
		if (labels_set(label) == labels_set(l)) {
			goto insert;
		} else {
1828
			aa_label_remove(labels_set(label), label);
1829
			goto other_ls_insert;
1830
		}
1831
	} else {
1832
		AA_BUG(labels_ns(label) != labels_ns(l));
1833 1834 1835
		goto insert;
	}
insert:
1836
	tmp = __aa_label_remove_and_insert(labels_set(label), label, l, true);
1837 1838 1839 1840 1841 1842
	if (tmp != l) {
		aa_label_free(l);
		l = tmp;
	} else
		aa_put_label(l);	/* extr ref */

1843
	write_unlock_irqrestore(&ls->lock, flags);
1844

1845
	return l;
1846

1847 1848 1849 1850 1851 1852
other_ls_insert:
	write_unlock_irqrestore(&ls->lock, flags);
	tmp = aa_label_insert(labels_set(l), l);
	if (tmp != l) {
		aa_put_label(l);
		l = tmp;
1853
	}
1854 1855

	return l;
1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
}

/**
 * __labelset_update - invalidate and update labels in @ns
 * @ns: namespace to update and invalidate labels in  (NOT NULL)
 *
 * Requires: @ns lock be held
 *
 * Walk the labelset ensuring that all labels are up to date and valid
 * Any label that is outdated is replaced and by an updated version
 * invalidated and removed from the tree.
 *
 * If failures happen due to memory pressures then stale labels will
 * be left in place until the next pass.
 */
static void __labelset_update(struct aa_namespace *ns)
{
	struct aa_label *label;

	AA_BUG(!ns);
	AA_BUG(!mutex_is_locked(&ns->lock));

	do {
		label = labelset_next_invalid(&ns->labels);
		if (label) {
			struct aa_label *l;
			l = __label_update(label);
			aa_put_label(l);
			aa_put_label(label);
		}
	} while (label);
}

/**
 * __aa_labelset_invalidate_all - invalidate labels in @ns and below
 * @ns: ns to start invalidation at (NOT NULL)
 *
 * Requires: @ns lock be held
 *
 * Invalidates labels based on @p in @ns and any children namespaces.
*/
void __aa_labelset_update_all(struct aa_namespace *ns)
{
	struct aa_namespace *child;

	AA_BUG(!ns);
	AA_BUG(!mutex_is_locked(&ns->lock));

	__labelset_update(ns);

	list_for_each_entry(child, &ns->sub_ns, base.list) {
		mutex_lock(&child->lock);
		__aa_labelset_update_all(child);
		mutex_unlock(&child->lock);
	}
}