[PATCH 12/12] apparmor: Add the profile introspection file to interface

From: John Johansen
Date: Sat Jul 20 2013 - 04:41:35 EST


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@xxxxxxxxxxxxx>
Acked-by: Kees Cook <kees@xxxxxxxxxx>
---
security/apparmor/apparmorfs.c | 236 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 236 insertions(+)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index d6329aa..7a26608 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -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 @@ fail2:
}


+#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),
{ }
};
--
1.8.1.2

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