1 files changed, 239 insertions, 0 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
new file mode 100644
index 000000000000..7320331b44ab
--- /dev/null
+++ b/security/apparmor/apparmorfs.c
@@ -0,0 +1,239 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor /sys/kernel/security/apparmor interface 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.
+ */
+
+#include <linux/security.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/namei.h>
+
+#include "include/apparmor.h"
+#include "include/apparmorfs.h"
+#include "include/audit.h"
+#include "include/context.h"
+#include "include/policy.h"
+
+/**
+ * aa_simple_write_to_buffer - common routine for getting policy from user
+ * @op: operation doing the user buffer copy
+ * @userbuf: user buffer to copy data from  (NOT NULL)
+ * @alloc_size: size of user buffer
+ * @copy_size: size of data to copy from user buffer
+ * @pos: position write is at in the file (NOT NULL)
+ *
+ * Returns: kernel buffer containing copy of user buffer data or an
+ *          ERR_PTR on failure.
+ */
+static char *aa_simple_write_to_buffer(int op, const char __user *userbuf,
+				       size_t alloc_size, size_t copy_size,
+				       loff_t *pos)
+{
+	char *data;
+
+	if (*pos != 0)
+		/* only writes from pos 0, that is complete writes */
+		return ERR_PTR(-ESPIPE);
+
+	/*
+	 * Don't allow profile load/replace/remove from profiles that don't
+	 * have CAP_MAC_ADMIN
+	 */
+	if (!aa_may_manage_policy(op))
+		return ERR_PTR(-EACCES);
+
+	/* freed by caller to simple_write_to_buffer */
+	data = kvmalloc(alloc_size);
+	if (data == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(data, userbuf, copy_size)) {
+		kvfree(data);
+		return ERR_PTR(-EFAULT);
+	}
+
+	return data;
+}
+
+
+/* .load file hook fn to load policy */
+static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
+			    loff_t *pos)
+{
+	char *data;
+	ssize_t error;
+
+	data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);
+
+	error = PTR_ERR(data);
+	if (!IS_ERR(data)) {
+		error = aa_replace_profiles(data, size, PROF_ADD);
+		kvfree(data);
+	}
+
+	return error;
+}
+
+static const struct file_operations aa_fs_profile_load = {
+	.write = profile_load
+};
+
+/* .replace file hook fn to load and/or replace policy */
+static ssize_t profile_replace(struct file *f, const char __user *buf,
+			       size_t size, loff_t *pos)
+{
+	char *data;
+	ssize_t error;
+
+	data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
+	error = PTR_ERR(data);
+	if (!IS_ERR(data)) {
+		error = aa_replace_profiles(data, size, PROF_REPLACE);
+		kvfree(data);
+	}
+
+	return error;
+}
+
+static const struct file_operations aa_fs_profile_replace = {
+	.write = profile_replace
+};
+
+/* .remove file hook fn to remove loaded policy */
+static ssize_t profile_remove(struct file *f, const char __user *buf,
+			      size_t size, loff_t *pos)
+{
+	char *data;
+	ssize_t error;
+
+	/*
+	 * aa_remove_profile needs a null terminated string so 1 extra
+	 * byte is allocated and the copied data is null terminated.
+	 */
+	data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);
+
+	error = PTR_ERR(data);
+	if (!IS_ERR(data)) {
+		data[size] = 0;
+		error = aa_remove_profiles(data, size);
+		kvfree(data);
+	}
+
+	return error;
+}
+
+static const struct file_operations aa_fs_profile_remove = {
+	.write = profile_remove
+};
+
+/** Base file system setup **/
+
+static struct dentry *aa_fs_dentry __initdata;
+
+static void __init aafs_remove(const char *name)
+{
+	struct dentry *dentry;
+
+	dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
+	if (!IS_ERR(dentry)) {
+		securityfs_remove(dentry);
+		dput(dentry);
+	}
+}
+
+/**
+ * aafs_create - create an entry in the apparmor filesystem
+ * @name: name of the entry (NOT NULL)
+ * @mask: file permission mask of the file
+ * @fops: file operations for the file (NOT NULL)
+ *
+ * Used aafs_remove to remove entries created with this fn.
+ */
+static int __init aafs_create(const char *name, int mask,
+			      const struct file_operations *fops)
+{
+	struct dentry *dentry;
+
+	dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
+					NULL, fops);
+
+	return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
+}
+
+/**
+ * aa_destroy_aafs - cleanup and free aafs
+ *
+ * releases dentries allocated by aa_create_aafs
+ */
+void __init aa_destroy_aafs(void)
+{
+	if (aa_fs_dentry) {
+		aafs_remove(".remove");
+		aafs_remove(".replace");
+		aafs_remove(".load");
+
+		securityfs_remove(aa_fs_dentry);
+		aa_fs_dentry = NULL;
+	}
+}
+
+/**
+ * aa_create_aafs - create the apparmor security filesystem
+ *
+ * dentries created here are released by aa_destroy_aafs
+ *
+ * Returns: error on failure
+ */
+int __init aa_create_aafs(void)
+{
+	int error;
+
+	if (!apparmor_initialized)
+		return 0;
+
+	if (aa_fs_dentry) {
+		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
+		return -EEXIST;
+	}
+
+	aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
+	if (IS_ERR(aa_fs_dentry)) {
+		error = PTR_ERR(aa_fs_dentry);
+		aa_fs_dentry = NULL;
+		goto error;
+	}
+
+	error = aafs_create(".load", 0640, &aa_fs_profile_load);
+	if (error)
+		goto error;
+	error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
+	if (error)
+		goto error;
+	error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
+	if (error)
+		goto error;
+
+	/* TODO: add support for apparmorfs_null and apparmorfs_mnt */
+
+	/* Report that AppArmor fs is enabled */
+	aa_info_message("AppArmor Filesystem Enabled");
+	return 0;
+
+error:
+	aa_destroy_aafs();
+	AA_ERROR("Error creating AppArmor securityfs\n");
+	return error;
+}
+
+fs_initcall(aa_create_aafs);