Commit 29b3822f authored by John Johansen's avatar John Johansen
Browse files

apparmor: add the profile introspection file to interface 



Add the dynamic namespace relative profiles file to the interace, to allow
introspection of loaded profiles and their modes.

Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
Acked-by: default avatarKees Cook <kees@ubuntu.com>
parent 556d0be7

security/apparmor/apparmorfs.c

+236 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/uaccess.h>

#include <linux/namei.h>

#include <linux/capability.h>

#include <linux/rcupdate.h>



#include "include/apparmor.h"

#include "include/apparmorfs.h"
@@ -512,6 +513,240 @@ int __aa_fs_namespace_mkdir(struct aa_namespace *ns, struct dentry *parent, 
}





#define list_entry_next(pos, member) \

	list_entry(pos->member.next, typeof(*pos), member)

#define list_entry_is_head(pos, head, member) (&pos->member == (head))



/**

 * __next_namespace - find the next namespace to list

 * @root: root namespace to stop search at (NOT NULL)

 * @ns: current ns position (NOT NULL)

 *

 * Find the next namespace from @ns under @root and handle all locking needed

 * while switching current namespace.

 *

 * Returns: next namespace or NULL if at last namespace under @root

 * Requires: ns->parent->lock to be held

 * NOTE: will not unlock root->lock

 */

static struct aa_namespace *__next_namespace(struct aa_namespace *root,

					     struct aa_namespace *ns)

{

	struct aa_namespace *parent, *next;



	/* is next namespace a child */

	if (!list_empty(&ns->sub_ns)) {

		next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list);

		mutex_lock(&next->lock);

		return next;

	}



	/* check if the next ns is a sibling, parent, gp, .. */

	parent = ns->parent;

	while (parent) {

		mutex_unlock(&ns->lock);

		next = list_entry_next(ns, base.list);

		if (!list_entry_is_head(next, &parent->sub_ns, base.list)) {

			mutex_lock(&next->lock);

			return next;

		}

		if (parent == root)

			return NULL;

		ns = parent;

		parent = parent->parent;

	}



	return NULL;

}



/**

 * __first_profile - find the first profile in a namespace

 * @root: namespace that is root of profiles being displayed (NOT NULL)

 * @ns: namespace to start in   (NOT NULL)

 *

 * Returns: unrefcounted profile or NULL if no profile

 * Requires: profile->ns.lock to be held

 */

static struct aa_profile *__first_profile(struct aa_namespace *root,

					  struct aa_namespace *ns)

{

	for (; ns; ns = __next_namespace(root, ns)) {

		if (!list_empty(&ns->base.profiles))

			return list_first_entry(&ns->base.profiles,

						struct aa_profile, base.list);

	}

	return NULL;

}



/**

 * __next_profile - step to the next profile in a profile tree

 * @profile: current profile in tree (NOT NULL)

 *

 * Perform a depth first traversal on the profile tree in a namespace

 *

 * Returns: next profile or NULL if done

 * Requires: profile->ns.lock to be held

 */

static struct aa_profile *__next_profile(struct aa_profile *p)

{

	struct aa_profile *parent;

	struct aa_namespace *ns = p->ns;



	/* is next profile a child */

	if (!list_empty(&p->base.profiles))

		return list_first_entry(&p->base.profiles, typeof(*p),

					base.list);



	/* is next profile a sibling, parent sibling, gp, sibling, .. */

	parent = rcu_dereference_protected(p->parent,

					   mutex_is_locked(&p->ns->lock));

	while (parent) {

		p = list_entry_next(p, base.list);

		if (!list_entry_is_head(p, &parent->base.profiles, base.list))

			return p;

		p = parent;

		parent = rcu_dereference_protected(parent->parent,

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

	}



	/* is next another profile in the namespace */

	p = list_entry_next(p, base.list);

	if (!list_entry_is_head(p, &ns->base.profiles, base.list))

		return p;



	return NULL;

}



/**

 * next_profile - step to the next profile in where ever it may be

 * @root: root namespace  (NOT NULL)

 * @profile: current profile  (NOT NULL)

 *

 * Returns: next profile or NULL if there isn't one

 */

static struct aa_profile *next_profile(struct aa_namespace *root,

				       struct aa_profile *profile)

{

	struct aa_profile *next = __next_profile(profile);

	if (next)

		return next;



	/* finished all profiles in namespace move to next namespace */

	return __first_profile(root, __next_namespace(root, profile->ns));

}



/**

 * p_start - start a depth first traversal of profile tree

 * @f: seq_file to fill

 * @pos: current position

 *

 * Returns: first profile under current namespace or NULL if none found

 *

 * acquires first ns->lock

 */

static void *p_start(struct seq_file *f, loff_t *pos)

{

	struct aa_profile *profile = NULL;

	struct aa_namespace *root = aa_current_profile()->ns;

	loff_t l = *pos;

	f->private = aa_get_namespace(root);





	/* find the first profile */

	mutex_lock(&root->lock);

	profile = __first_profile(root, root);



	/* skip to position */

	for (; profile && l > 0; l--)

		profile = next_profile(root, profile);



	return profile;

}



/**

 * p_next - read the next profile entry

 * @f: seq_file to fill

 * @p: profile previously returned

 * @pos: current position

 *

 * Returns: next profile after @p or NULL if none

 *

 * may acquire/release locks in namespace tree as necessary

 */

static void *p_next(struct seq_file *f, void *p, loff_t *pos)

{

	struct aa_profile *profile = p;

	struct aa_namespace *ns = f->private;

	(*pos)++;



	return next_profile(ns, profile);

}



/**

 * p_stop - stop depth first traversal

 * @f: seq_file we are filling

 * @p: the last profile writen

 *

 * Release all locking done by p_start/p_next on namespace tree

 */

static void p_stop(struct seq_file *f, void *p)

{

	struct aa_profile *profile = p;

	struct aa_namespace *root = f->private, *ns;



	if (profile) {

		for (ns = profile->ns; ns && ns != root; ns = ns->parent)

			mutex_unlock(&ns->lock);

	}

	mutex_unlock(&root->lock);

	aa_put_namespace(root);

}



/**

 * seq_show_profile - show a profile entry

 * @f: seq_file to file

 * @p: current position (profile)    (NOT NULL)

 *

 * Returns: error on failure

 */

static int seq_show_profile(struct seq_file *f, void *p)

{

	struct aa_profile *profile = (struct aa_profile *)p;

	struct aa_namespace *root = f->private;



	if (profile->ns != root)

		seq_printf(f, ":%s://", aa_ns_name(root, profile->ns));

	seq_printf(f, "%s (%s)\n", profile->base.hname,

		   aa_profile_mode_names[profile->mode]);



	return 0;

}



static const struct seq_operations aa_fs_profiles_op = {

	.start = p_start,

	.next = p_next,

	.stop = p_stop,

	.show = seq_show_profile,

};



static int profiles_open(struct inode *inode, struct file *file)

{

	return seq_open(file, &aa_fs_profiles_op);

}



static int profiles_release(struct inode *inode, struct file *file)

{

	return seq_release(inode, file);

}



static const struct file_operations aa_fs_profiles_fops = {

	.open = profiles_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = profiles_release,

};





/** Base file system setup **/

static struct aa_fs_entry aa_fs_entry_file[] = {

	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
@@ -545,6 +780,7 @@ static struct aa_fs_entry aa_fs_entry_apparmor[] = { 
	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),

	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),

	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),

	AA_FS_FILE_FOPS("profiles", 0640, &aa_fs_profiles_fops),

	AA_FS_DIR("features", aa_fs_entry_features),

	{ }

};