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: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
This commit is contained in:
John Johansen 2013-07-10 21:18:43 -07:00
parent 556d0be74b
commit 29b3822f1e

View file

@ -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),
{ }
};