[deliverable/linux.git] / security / apparmor / apparmorfs.c

/*
 * 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 <linux/capability.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 (REQUIRES: @alloc_size >= @copy_size)
 * @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;

	BUG_ON(copy_size > alloc_size);

	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,
	.llseek = default_llseek,
};

/* .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,
	.llseek = default_llseek,
};

/* .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,
	.llseek = default_llseek,
};

static int aa_fs_seq_show(struct seq_file *seq, void *v)
{
	struct aa_fs_entry *fs_file = seq->private;

	if (!fs_file)
		return 0;

	switch (fs_file->v_type) {
	case AA_FS_TYPE_BOOLEAN:
		seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
		break;
	case AA_FS_TYPE_STRING:
		seq_printf(seq, "%s\n", fs_file->v.string);
		break;
	case AA_FS_TYPE_U64:
		seq_printf(seq, "%#08lx\n", fs_file->v.u64);
		break;
	default:
		/* Ignore unpritable entry types. */
		break;
	}

	return 0;
}

static int aa_fs_seq_open(struct inode *inode, struct file *file)
{
	return single_open(file, aa_fs_seq_show, inode->i_private);
}

const struct file_operations aa_fs_seq_file_ops = {
	.owner		= THIS_MODULE,
	.open		= aa_fs_seq_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_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 " \
				  "link lock"),
	{ }
};

static struct aa_fs_entry aa_fs_entry_domain[] = {
	AA_FS_FILE_BOOLEAN("change_hat",	1),
	AA_FS_FILE_BOOLEAN("change_hatv",	1),
	AA_FS_FILE_BOOLEAN("change_onexec",	1),
	AA_FS_FILE_BOOLEAN("change_profile",	1),
	{ }
};

static struct aa_fs_entry aa_fs_entry_features[] = {
	AA_FS_DIR("domain",			aa_fs_entry_domain),
	AA_FS_DIR("file",			aa_fs_entry_file),
	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
	{ }
};

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_DIR("features", aa_fs_entry_features),
	{ }
};

static struct aa_fs_entry aa_fs_entry =
	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);

/**
 * aafs_create_file - create a file entry in the apparmor securityfs
 * @fs_file: aa_fs_entry to build an entry for (NOT NULL)
 * @parent: the parent dentry in the securityfs
 *
 * Use aafs_remove_file to remove entries created with this fn.
 */
static int __init aafs_create_file(struct aa_fs_entry *fs_file,
				   struct dentry *parent)
{
	int error = 0;

	fs_file->dentry = securityfs_create_file(fs_file->name,
						 S_IFREG | fs_file->mode,
						 parent, fs_file,
						 fs_file->file_ops);
	if (IS_ERR(fs_file->dentry)) {
		error = PTR_ERR(fs_file->dentry);
		fs_file->dentry = NULL;
	}
	return error;
}

/**
 * aafs_create_dir - recursively create a directory entry in the securityfs
 * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
 * @parent: the parent dentry in the securityfs
 *
 * Use aafs_remove_dir to remove entries created with this fn.
 */
static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
				  struct dentry *parent)
{
	int error;
	struct aa_fs_entry *fs_file;

	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
	if (IS_ERR(fs_dir->dentry)) {
		error = PTR_ERR(fs_dir->dentry);
		fs_dir->dentry = NULL;
		goto failed;
	}

	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
		if (fs_file->v_type == AA_FS_TYPE_DIR)
			error = aafs_create_dir(fs_file, fs_dir->dentry);
		else
			error = aafs_create_file(fs_file, fs_dir->dentry);
		if (error)
			goto failed;
	}

	return 0;

failed:
	return error;
}

/**
 * aafs_remove_file - drop a single file entry in the apparmor securityfs
 * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
 */
static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
{
	if (!fs_file->dentry)
		return;

	securityfs_remove(fs_file->dentry);
	fs_file->dentry = NULL;
}

/**
 * aafs_remove_dir - recursively drop a directory entry from the securityfs
 * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
 */
static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
{
	struct aa_fs_entry *fs_file;

	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
		if (fs_file->v_type == AA_FS_TYPE_DIR)
			aafs_remove_dir(fs_file);
		else
			aafs_remove_file(fs_file);
	}

	aafs_remove_file(fs_dir);
}

/**
 * aa_destroy_aafs - cleanup and free aafs
 *
 * releases dentries allocated by aa_create_aafs
 */
void __init aa_destroy_aafs(void)
{
	aafs_remove_dir(&aa_fs_entry);
}

/**
 * aa_create_aafs - create the apparmor security filesystem
 *
 * dentries created here are released by aa_destroy_aafs
 *
 * Returns: error on failure
 */
static int __init aa_create_aafs(void)
{
	int error;

	if (!apparmor_initialized)
		return 0;

	if (aa_fs_entry.dentry) {
		AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
		return -EEXIST;
	}

	/* Populate fs tree. */
	error = aafs_create_dir(&aa_fs_entry, NULL);
	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);
Commit	Line	Data
63e2b423 JJ	1	/*
	2	* AppArmor security module
	3	*
	4	* This file contains AppArmor /sys/kernel/security/apparmor interface functions
	5	*
	6	* Copyright (C) 1998-2008 Novell/SUSE
	7	* Copyright 2009-2010 Canonical Ltd.
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License as
	11	* published by the Free Software Foundation, version 2 of the
	12	* License.
	13	*/
	14
	15	#include <linux/security.h>
	16	#include <linux/vmalloc.h>
	17	#include <linux/module.h>
	18	#include <linux/seq_file.h>
	19	#include <linux/uaccess.h>
	20	#include <linux/namei.h>
e74abcf3	21	#include <linux/capability.h>
63e2b423 JJ	22
	23	#include "include/apparmor.h"
	24	#include "include/apparmorfs.h"
	25	#include "include/audit.h"
	26	#include "include/context.h"
	27	#include "include/policy.h"
	28
	29	/**
	30	* aa_simple_write_to_buffer - common routine for getting policy from user
	31	* @op: operation doing the user buffer copy
	32	* @userbuf: user buffer to copy data from (NOT NULL)
3ed02ada	33	* @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
63e2b423 JJ	34	* @copy_size: size of data to copy from user buffer
	35	* @pos: position write is at in the file (NOT NULL)
	36	*
	37	* Returns: kernel buffer containing copy of user buffer data or an
	38	* ERR_PTR on failure.
	39	*/
	40	static char aa_simple_write_to_buffer(int op, const char __user userbuf,
	41	size_t alloc_size, size_t copy_size,
	42	loff_t *pos)
	43	{
	44	char *data;
	45
3ed02ada JJ	46	BUG_ON(copy_size > alloc_size);
3ed02ada JJ	47
63e2b423 JJ	48	if (*pos != 0)
	49	/* only writes from pos 0, that is complete writes */
	50	return ERR_PTR(-ESPIPE);
	51
	52	/*
	53	* Don't allow profile load/replace/remove from profiles that don't
	54	* have CAP_MAC_ADMIN
	55	*/
	56	if (!aa_may_manage_policy(op))
	57	return ERR_PTR(-EACCES);
	58
	59	/* freed by caller to simple_write_to_buffer */
	60	data = kvmalloc(alloc_size);
	61	if (data == NULL)
	62	return ERR_PTR(-ENOMEM);
	63
	64	if (copy_from_user(data, userbuf, copy_size)) {
	65	kvfree(data);
	66	return ERR_PTR(-EFAULT);
	67	}
	68
	69	return data;
	70	}
	71
	72
	73	/* .load file hook fn to load policy */
	74	static ssize_t profile_load(struct file f, const char __user buf, size_t size,
	75	loff_t *pos)
	76	{
	77	char *data;
	78	ssize_t error;
	79
	80	data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);
	81
	82	error = PTR_ERR(data);
	83	if (!IS_ERR(data)) {
	84	error = aa_replace_profiles(data, size, PROF_ADD);
	85	kvfree(data);
	86	}
	87
	88	return error;
	89	}
	90
	91	static const struct file_operations aa_fs_profile_load = {
6038f373 AB	92	.write = profile_load,
6038f373 AB	93	.llseek = default_llseek,
63e2b423 JJ	94	};
	95
	96	/* .replace file hook fn to load and/or replace policy */
	97	static ssize_t profile_replace(struct file f, const char __user buf,
	98	size_t size, loff_t *pos)
	99	{
	100	char *data;
	101	ssize_t error;
	102
	103	data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
	104	error = PTR_ERR(data);
	105	if (!IS_ERR(data)) {
	106	error = aa_replace_profiles(data, size, PROF_REPLACE);
	107	kvfree(data);
	108	}
	109
	110	return error;
	111	}
	112
	113	static const struct file_operations aa_fs_profile_replace = {
6038f373 AB	114	.write = profile_replace,
6038f373 AB	115	.llseek = default_llseek,
63e2b423 JJ	116	};
	117
	118	/* .remove file hook fn to remove loaded policy */
	119	static ssize_t profile_remove(struct file f, const char __user buf,
	120	size_t size, loff_t *pos)
	121	{
	122	char *data;
	123	ssize_t error;
	124
	125	/*
	126	* aa_remove_profile needs a null terminated string so 1 extra
	127	* byte is allocated and the copied data is null terminated.
	128	*/
	129	data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);
	130
	131	error = PTR_ERR(data);
	132	if (!IS_ERR(data)) {
	133	data[size] = 0;
	134	error = aa_remove_profiles(data, size);
	135	kvfree(data);
	136	}
	137
	138	return error;
	139	}
	140
	141	static const struct file_operations aa_fs_profile_remove = {
6038f373 AB	142	.write = profile_remove,
6038f373 AB	143	.llseek = default_llseek,
63e2b423 JJ	144	};
63e2b423 JJ	145
e74abcf3 KC	146	static int aa_fs_seq_show(struct seq_file seq, void v)
	147	{
	148	struct aa_fs_entry *fs_file = seq->private;
	149
	150	if (!fs_file)
	151	return 0;
	152
	153	switch (fs_file->v_type) {
	154	case AA_FS_TYPE_BOOLEAN:
	155	seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
	156	break;
a9bf8e9f KC	157	case AA_FS_TYPE_STRING:
	158	seq_printf(seq, "%s\n", fs_file->v.string);
	159	break;
e74abcf3 KC	160	case AA_FS_TYPE_U64:
	161	seq_printf(seq, "%#08lx\n", fs_file->v.u64);
	162	break;
	163	default:
	164	/* Ignore unpritable entry types. */
	165	break;
	166	}
	167
	168	return 0;
	169	}
	170
	171	static int aa_fs_seq_open(struct inode inode, struct file file)
	172	{
	173	return single_open(file, aa_fs_seq_show, inode->i_private);
	174	}
	175
	176	const struct file_operations aa_fs_seq_file_ops = {
	177	.owner = THIS_MODULE,
	178	.open = aa_fs_seq_open,
	179	.read = seq_read,
	180	.llseek = seq_lseek,
	181	.release = single_release,
	182	};
	183
63e2b423 JJ	184	/ Base file system setup /
63e2b423 JJ	185
a9bf8e9f KC	186	static struct aa_fs_entry aa_fs_entry_file[] = {
	187	AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \
	188	"link lock"),
	189	{ }
	190	};
	191
e74abcf3 KC	192	static struct aa_fs_entry aa_fs_entry_domain[] = {
	193	AA_FS_FILE_BOOLEAN("change_hat", 1),
	194	AA_FS_FILE_BOOLEAN("change_hatv", 1),
	195	AA_FS_FILE_BOOLEAN("change_onexec", 1),
	196	AA_FS_FILE_BOOLEAN("change_profile", 1),
	197	{ }
	198	};
	199
	200	static struct aa_fs_entry aa_fs_entry_features[] = {
	201	AA_FS_DIR("domain", aa_fs_entry_domain),
a9bf8e9f	202	AA_FS_DIR("file", aa_fs_entry_file),
e74abcf3 KC	203	AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK),
	204	{ }
	205	};
	206
9acd494b KC	207	static struct aa_fs_entry aa_fs_entry_apparmor[] = {
	208	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
	209	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
	210	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
e74abcf3	211	AA_FS_DIR("features", aa_fs_entry_features),
9acd494b KC	212	{ }
9acd494b KC	213	};
63e2b423	214
9acd494b KC	215	static struct aa_fs_entry aa_fs_entry =
9acd494b KC	216	AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
63e2b423	217
9acd494b KC	218	/**
	219	* aafs_create_file - create a file entry in the apparmor securityfs
	220	* @fs_file: aa_fs_entry to build an entry for (NOT NULL)
	221	* @parent: the parent dentry in the securityfs
	222	*
	223	* Use aafs_remove_file to remove entries created with this fn.
	224	*/
	225	static int __init aafs_create_file(struct aa_fs_entry *fs_file,
	226	struct dentry *parent)
	227	{
	228	int error = 0;
	229
	230	fs_file->dentry = securityfs_create_file(fs_file->name,
	231	S_IFREG \| fs_file->mode,
	232	parent, fs_file,
	233	fs_file->file_ops);
	234	if (IS_ERR(fs_file->dentry)) {
	235	error = PTR_ERR(fs_file->dentry);
	236	fs_file->dentry = NULL;
63e2b423	237	}
9acd494b	238	return error;
63e2b423 JJ	239	}
	240
	241	/**
9acd494b KC	242	* aafs_create_dir - recursively create a directory entry in the securityfs
	243	* @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
	244	* @parent: the parent dentry in the securityfs
63e2b423	245	*
9acd494b	246	* Use aafs_remove_dir to remove entries created with this fn.
63e2b423	247	*/
9acd494b KC	248	static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
9acd494b KC	249	struct dentry *parent)
63e2b423	250	{
9acd494b KC	251	int error;
9acd494b KC	252	struct aa_fs_entry *fs_file;
63e2b423	253
9acd494b KC	254	fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
	255	if (IS_ERR(fs_dir->dentry)) {
	256	error = PTR_ERR(fs_dir->dentry);
	257	fs_dir->dentry = NULL;
	258	goto failed;
	259	}
63e2b423	260
9acd494b KC	261	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	262	if (fs_file->v_type == AA_FS_TYPE_DIR)
	263	error = aafs_create_dir(fs_file, fs_dir->dentry);
	264	else
	265	error = aafs_create_file(fs_file, fs_dir->dentry);
	266	if (error)
	267	goto failed;
	268	}
	269
	270	return 0;
	271
	272	failed:
	273	return error;
	274	}
	275
	276	/**
	277	* aafs_remove_file - drop a single file entry in the apparmor securityfs
	278	* @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
	279	*/
	280	static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
	281	{
	282	if (!fs_file->dentry)
	283	return;
	284
	285	securityfs_remove(fs_file->dentry);
	286	fs_file->dentry = NULL;
	287	}
	288
	289	/**
	290	* aafs_remove_dir - recursively drop a directory entry from the securityfs
	291	* @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
	292	*/
	293	static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
	294	{
	295	struct aa_fs_entry *fs_file;
	296
	297	for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
	298	if (fs_file->v_type == AA_FS_TYPE_DIR)
	299	aafs_remove_dir(fs_file);
	300	else
	301	aafs_remove_file(fs_file);
	302	}
	303
	304	aafs_remove_file(fs_dir);
63e2b423 JJ	305	}
	306
	307	/**
	308	* aa_destroy_aafs - cleanup and free aafs
	309	*
	310	* releases dentries allocated by aa_create_aafs
	311	*/
	312	void __init aa_destroy_aafs(void)
	313	{
9acd494b	314	aafs_remove_dir(&aa_fs_entry);
63e2b423 JJ	315	}
	316
	317	/**
	318	* aa_create_aafs - create the apparmor security filesystem
	319	*
	320	* dentries created here are released by aa_destroy_aafs
	321	*
	322	* Returns: error on failure
	323	*/
3417d8d5	324	static int __init aa_create_aafs(void)
63e2b423 JJ	325	{
	326	int error;
	327
	328	if (!apparmor_initialized)
	329	return 0;
	330
9acd494b	331	if (aa_fs_entry.dentry) {
63e2b423 JJ	332	AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
	333	return -EEXIST;
	334	}
	335
9acd494b KC	336	/* Populate fs tree. */
9acd494b KC	337	error = aafs_create_dir(&aa_fs_entry, NULL);
63e2b423 JJ	338	if (error)
	339	goto error;
	340
	341	/* TODO: add support for apparmorfs_null and apparmorfs_mnt */
	342
	343	/* Report that AppArmor fs is enabled */
	344	aa_info_message("AppArmor Filesystem Enabled");
	345	return 0;
	346
	347	error:
	348	aa_destroy_aafs();
	349	AA_ERROR("Error creating AppArmor securityfs\n");
	350	return error;
	351	}
	352
	353	fs_initcall(aa_create_aafs);