[net-next-2.6.git] / security / tomoyo / tomoyo.c

/*
 * security/tomoyo/tomoyo.c
 *
 * LSM hooks for TOMOYO Linux.
 *
 * Copyright (C) 2005-2009  NTT DATA CORPORATION
 *
 * Version: 2.2.0   2009/04/01
 *
 */

#include <linux/security.h>
#include "common.h"

static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
{
	new->security = NULL;
	return 0;
}

static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
			       gfp_t gfp)
{
	struct tomoyo_domain_info *domain = old->security;
	new->security = domain;
	if (domain)
		atomic_inc(&domain->users);
	return 0;
}

static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
{
	tomoyo_cred_prepare(new, old, 0);
}

static void tomoyo_cred_free(struct cred *cred)
{
	struct tomoyo_domain_info *domain = cred->security;
	if (domain)
		atomic_dec(&domain->users);
}

static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
{
	int rc;

	rc = cap_bprm_set_creds(bprm);
	if (rc)
		return rc;

	/*
	 * Do only if this function is called for the first time of an execve
	 * operation.
	 */
	if (bprm->cred_prepared)
		return 0;
	/*
	 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	 * for the first time.
	 */
	if (!tomoyo_policy_loaded)
		tomoyo_load_policy(bprm->filename);
	/*
	 * Release reference to "struct tomoyo_domain_info" stored inside
	 * "bprm->cred->security". New reference to "struct tomoyo_domain_info"
	 * stored inside "bprm->cred->security" will be acquired later inside
	 * tomoyo_find_next_domain().
	 */
	atomic_dec(&((struct tomoyo_domain_info *)
		     bprm->cred->security)->users);
	/*
	 * Tell tomoyo_bprm_check_security() is called for the first time of an
	 * execve operation.
	 */
	bprm->cred->security = NULL;
	return 0;
}

static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
{
	struct tomoyo_domain_info *domain = bprm->cred->security;

	/*
	 * Execute permission is checked against pathname passed to do_execve()
	 * using current domain.
	 */
	if (!domain) {
		const int idx = tomoyo_read_lock();
		const int err = tomoyo_find_next_domain(bprm);
		tomoyo_read_unlock(idx);
		return err;
	}
	/*
	 * Read permission is checked against interpreters using next domain.
	 * '1' is the result of open_to_namei_flags(O_RDONLY).
	 */
	return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
}

static int tomoyo_path_truncate(struct path *path, loff_t length,
				unsigned int time_attrs)
{
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_TRUNCATE_ACL,
				       path);
}

static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_UNLINK_ACL,
				       &path);
}

static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
			     int mode)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_MKDIR_ACL,
				       &path);
}

static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_RMDIR_ACL,
				       &path);
}

static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
			       const char *old_name)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_SYMLINK_ACL,
				       &path);
}

static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
			     int mode, unsigned int dev)
{
	struct path path = { parent->mnt, dentry };
	int type = TOMOYO_TYPE_CREATE_ACL;

	switch (mode & S_IFMT) {
	case S_IFCHR:
		type = TOMOYO_TYPE_MKCHAR_ACL;
		break;
	case S_IFBLK:
		type = TOMOYO_TYPE_MKBLOCK_ACL;
		break;
	case S_IFIFO:
		type = TOMOYO_TYPE_MKFIFO_ACL;
		break;
	case S_IFSOCK:
		type = TOMOYO_TYPE_MKSOCK_ACL;
		break;
	}
	return tomoyo_check_1path_perm(tomoyo_domain(),
				       type, &path);
}

static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
			    struct dentry *new_dentry)
{
	struct path path1 = { new_dir->mnt, old_dentry };
	struct path path2 = { new_dir->mnt, new_dentry };
	return tomoyo_check_2path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_LINK_ACL,
				       &path1, &path2);
}

static int tomoyo_path_rename(struct path *old_parent,
			      struct dentry *old_dentry,
			      struct path *new_parent,
			      struct dentry *new_dentry)
{
	struct path path1 = { old_parent->mnt, old_dentry };
	struct path path2 = { new_parent->mnt, new_dentry };
	return tomoyo_check_2path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_RENAME_ACL,
				       &path1, &path2);
}

static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))
		return tomoyo_check_rewrite_permission(tomoyo_domain(), file);
	return 0;
}

static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
{
	int flags = f->f_flags;

	if ((flags + 1) & O_ACCMODE)
		flags++;
	flags |= f->f_flags & (O_APPEND | O_TRUNC);
	/* Don't check read permission here if called from do_execve(). */
	if (current->in_execve)
		return 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
}

static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_IOCTL_ACL,
				       &file->f_path);
}

static int tomoyo_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
			     mode_t mode)
{
	struct path path = { mnt, dentry };
	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHMOD_ACL,
				       &path);
}

static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
{
	int error = 0;
	if (uid != (uid_t) -1)
		error = tomoyo_check_1path_perm(tomoyo_domain(),
						TOMOYO_TYPE_CHOWN_ACL, path);
	if (!error && gid != (gid_t) -1)
		error = tomoyo_check_1path_perm(tomoyo_domain(),
						TOMOYO_TYPE_CHGRP_ACL, path);
	return error;
}

static int tomoyo_path_chroot(struct path *path)
{
	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHROOT_ACL,
				       path);
}

static int tomoyo_sb_mount(char *dev_name, struct path *path,
			   char *type, unsigned long flags, void *data)
{
	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_MOUNT_ACL,
				       path);
}

static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
{
	struct path path = { mnt, mnt->mnt_root };
	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_UMOUNT_ACL,
				       &path);
}

static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
{
	return tomoyo_check_2path_perm(tomoyo_domain(),
				       TOMOYO_TYPE_PIVOT_ROOT_ACL,
				       new_path, old_path);
}

/*
 * tomoyo_security_ops is a "struct security_operations" which is used for
 * registering TOMOYO.
 */
static struct security_operations tomoyo_security_ops = {
	.name                = "tomoyo",
	.cred_alloc_blank    = tomoyo_cred_alloc_blank,
	.cred_prepare        = tomoyo_cred_prepare,
	.cred_transfer	     = tomoyo_cred_transfer,
	.cred_free           = tomoyo_cred_free,
	.bprm_set_creds      = tomoyo_bprm_set_creds,
	.bprm_check_security = tomoyo_bprm_check_security,
	.file_fcntl          = tomoyo_file_fcntl,
	.dentry_open         = tomoyo_dentry_open,
	.path_truncate       = tomoyo_path_truncate,
	.path_unlink         = tomoyo_path_unlink,
	.path_mkdir          = tomoyo_path_mkdir,
	.path_rmdir          = tomoyo_path_rmdir,
	.path_symlink        = tomoyo_path_symlink,
	.path_mknod          = tomoyo_path_mknod,
	.path_link           = tomoyo_path_link,
	.path_rename         = tomoyo_path_rename,
	.file_ioctl          = tomoyo_file_ioctl,
	.path_chmod          = tomoyo_path_chmod,
	.path_chown          = tomoyo_path_chown,
	.path_chroot         = tomoyo_path_chroot,
	.sb_mount            = tomoyo_sb_mount,
	.sb_umount           = tomoyo_sb_umount,
	.sb_pivotroot        = tomoyo_sb_pivotroot,
};

/* Lock for GC. */
struct srcu_struct tomoyo_ss;

static int __init tomoyo_init(void)
{
	struct cred *cred = (struct cred *) current_cred();

	if (!security_module_enable(&tomoyo_security_ops))
		return 0;
	/* register ourselves with the security framework */
	if (register_security(&tomoyo_security_ops) ||
	    init_srcu_struct(&tomoyo_ss))
		panic("Failure registering TOMOYO Linux");
	printk(KERN_INFO "TOMOYO Linux initialized\n");
	cred->security = &tomoyo_kernel_domain;
	tomoyo_realpath_init();
	return 0;
}

security_initcall(tomoyo_init);
Commit	Line	Data
f7433243 KT	1	/*
	2	* security/tomoyo/tomoyo.c
	3	*
	4	* LSM hooks for TOMOYO Linux.
	5	*
	6	* Copyright (C) 2005-2009 NTT DATA CORPORATION
	7	*
39826a1e	8	* Version: 2.2.0 2009/04/01
f7433243 KT	9	*
	10	*/
	11
	12	#include <linux/security.h>
	13	#include "common.h"
f7433243	14
ee18d64c DH	15	static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
	16	{
	17	new->security = NULL;
	18	return 0;
	19	}
	20
f7433243 KT	21	static int tomoyo_cred_prepare(struct cred new, const struct cred old,
	22	gfp_t gfp)
	23	{
ec8e6a4e TH	24	struct tomoyo_domain_info *domain = old->security;
	25	new->security = domain;
	26	if (domain)
	27	atomic_inc(&domain->users);
f7433243 KT	28	return 0;
	29	}
	30
ee18d64c DH	31	static void tomoyo_cred_transfer(struct cred new, const struct cred old)
ee18d64c DH	32	{
ec8e6a4e TH	33	tomoyo_cred_prepare(new, old, 0);
	34	}
	35
	36	static void tomoyo_cred_free(struct cred *cred)
	37	{
	38	struct tomoyo_domain_info *domain = cred->security;
	39	if (domain)
	40	atomic_dec(&domain->users);
ee18d64c DH	41	}
ee18d64c DH	42
f7433243 KT	43	static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
f7433243 KT	44	{
b1338d19 HRK	45	int rc;
	46
	47	rc = cap_bprm_set_creds(bprm);
	48	if (rc)
	49	return rc;
	50
f7433243 KT	51	/*
	52	* Do only if this function is called for the first time of an execve
	53	* operation.
	54	*/
	55	if (bprm->cred_prepared)
	56	return 0;
	57	/*
	58	* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	59	* for the first time.
	60	*/
	61	if (!tomoyo_policy_loaded)
	62	tomoyo_load_policy(bprm->filename);
ec8e6a4e TH	63	/*
	64	* Release reference to "struct tomoyo_domain_info" stored inside
	65	* "bprm->cred->security". New reference to "struct tomoyo_domain_info"
	66	* stored inside "bprm->cred->security" will be acquired later inside
	67	* tomoyo_find_next_domain().
	68	*/
	69	atomic_dec(&((struct tomoyo_domain_info *)
	70	bprm->cred->security)->users);
f7433243 KT	71	/*
	72	* Tell tomoyo_bprm_check_security() is called for the first time of an
	73	* execve operation.
	74	*/
	75	bprm->cred->security = NULL;
	76	return 0;
	77	}
	78
	79	static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
	80	{
	81	struct tomoyo_domain_info *domain = bprm->cred->security;
	82
	83	/*
	84	* Execute permission is checked against pathname passed to do_execve()
	85	* using current domain.
	86	*/
fdb8ebb7	87	if (!domain) {
fdb8ebb7 TH	88	const int idx = tomoyo_read_lock();
	89	const int err = tomoyo_find_next_domain(bprm);
	90	tomoyo_read_unlock(idx);
	91	return err;
	92	}
f7433243 KT	93	/*
	94	* Read permission is checked against interpreters using next domain.
	95	* '1' is the result of open_to_namei_flags(O_RDONLY).
	96	*/
	97	return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
	98	}
	99
f7433243 KT	100	static int tomoyo_path_truncate(struct path *path, loff_t length,
	101	unsigned int time_attrs)
	102	{
	103	return tomoyo_check_1path_perm(tomoyo_domain(),
	104	TOMOYO_TYPE_TRUNCATE_ACL,
	105	path);
	106	}
	107
	108	static int tomoyo_path_unlink(struct path parent, struct dentry dentry)
	109	{
	110	struct path path = { parent->mnt, dentry };
	111	return tomoyo_check_1path_perm(tomoyo_domain(),
	112	TOMOYO_TYPE_UNLINK_ACL,
	113	&path);
	114	}
	115
	116	static int tomoyo_path_mkdir(struct path parent, struct dentry dentry,
	117	int mode)
	118	{
	119	struct path path = { parent->mnt, dentry };
	120	return tomoyo_check_1path_perm(tomoyo_domain(),
	121	TOMOYO_TYPE_MKDIR_ACL,
	122	&path);
	123	}
	124
	125	static int tomoyo_path_rmdir(struct path parent, struct dentry dentry)
	126	{
	127	struct path path = { parent->mnt, dentry };
	128	return tomoyo_check_1path_perm(tomoyo_domain(),
	129	TOMOYO_TYPE_RMDIR_ACL,
	130	&path);
	131	}
	132
	133	static int tomoyo_path_symlink(struct path parent, struct dentry dentry,
	134	const char *old_name)
	135	{
	136	struct path path = { parent->mnt, dentry };
	137	return tomoyo_check_1path_perm(tomoyo_domain(),
	138	TOMOYO_TYPE_SYMLINK_ACL,
	139	&path);
	140	}
	141
	142	static int tomoyo_path_mknod(struct path parent, struct dentry dentry,
	143	int mode, unsigned int dev)
	144	{
	145	struct path path = { parent->mnt, dentry };
	146	int type = TOMOYO_TYPE_CREATE_ACL;
	147
	148	switch (mode & S_IFMT) {
	149	case S_IFCHR:
	150	type = TOMOYO_TYPE_MKCHAR_ACL;
	151	break;
	152	case S_IFBLK:
	153	type = TOMOYO_TYPE_MKBLOCK_ACL;
	154	break;
	155	case S_IFIFO:
	156	type = TOMOYO_TYPE_MKFIFO_ACL;
	157	break;
	158	case S_IFSOCK:
	159	type = TOMOYO_TYPE_MKSOCK_ACL;
	160	break;
	161	}
	162	return tomoyo_check_1path_perm(tomoyo_domain(),
	163	type, &path);
164	}
165
166	static int tomoyo_path_link(struct dentry old_dentry, struct path new_dir,
167	struct dentry *new_dentry)
168	{
169	struct path path1 = { new_dir->mnt, old_dentry };
170	struct path path2 = { new_dir->mnt, new_dentry };
171	return tomoyo_check_2path_perm(tomoyo_domain(),
172	TOMOYO_TYPE_LINK_ACL,
173	&path1, &path2);
174	}
175
176	static int tomoyo_path_rename(struct path *old_parent,
177	struct dentry *old_dentry,
178	struct path *new_parent,
179	struct dentry *new_dentry)
180	{
181	struct path path1 = { old_parent->mnt, old_dentry };
182	struct path path2 = { new_parent->mnt, new_dentry };
183	return tomoyo_check_2path_perm(tomoyo_domain(),
184	TOMOYO_TYPE_RENAME_ACL,
185	&path1, &path2);
186	}
187
188	static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
189	unsigned long arg)
190	{
191	if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))
192	return tomoyo_check_rewrite_permission(tomoyo_domain(), file);
193	return 0;
194	}
195
196	static int tomoyo_dentry_open(struct file f, const struct cred cred)
197	{
198	int flags = f->f_flags;
199
200	if ((flags + 1) & O_ACCMODE)
201	flags++;
202	flags \|= f->f_flags & (O_APPEND \| O_TRUNC);
203	/* Don't check read permission here if called from do_execve(). */
204	if (current->in_execve)
205	return 0;
206	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
207	}
208
937bf613 TH	209	static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
	210	unsigned long arg)
	211	{
	212	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_IOCTL_ACL,
	213	&file->f_path);
	214	}
	215
	216	static int tomoyo_path_chmod(struct dentry dentry, struct vfsmount mnt,
	217	mode_t mode)
	218	{
	219	struct path path = { mnt, dentry };
	220	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHMOD_ACL,
	221	&path);
	222	}
	223
	224	static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
	225	{
	226	int error = 0;
	227	if (uid != (uid_t) -1)
	228	error = tomoyo_check_1path_perm(tomoyo_domain(),
	229	TOMOYO_TYPE_CHOWN_ACL, path);
	230	if (!error && gid != (gid_t) -1)
	231	error = tomoyo_check_1path_perm(tomoyo_domain(),
	232	TOMOYO_TYPE_CHGRP_ACL, path);
	233	return error;
	234	}
	235
	236	static int tomoyo_path_chroot(struct path *path)
	237	{
	238	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHROOT_ACL,
	239	path);
	240	}
	241
	242	static int tomoyo_sb_mount(char dev_name, struct path path,
	243	char type, unsigned long flags, void data)
	244	{
	245	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_MOUNT_ACL,
	246	path);
	247	}
	248
	249	static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
	250	{
	251	struct path path = { mnt, mnt->mnt_root };
	252	return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_UMOUNT_ACL,
	253	&path);
	254	}
	255
	256	static int tomoyo_sb_pivotroot(struct path old_path, struct path new_path)
	257	{
	258	return tomoyo_check_2path_perm(tomoyo_domain(),
	259	TOMOYO_TYPE_PIVOT_ROOT_ACL,
	260	new_path, old_path);
	261	}
	262
c3fa109a TH	263	/*
	264	* tomoyo_security_ops is a "struct security_operations" which is used for
	265	* registering TOMOYO.
	266	*/
f7433243 KT	267	static struct security_operations tomoyo_security_ops = {
f7433243 KT	268	.name = "tomoyo",
ee18d64c	269	.cred_alloc_blank = tomoyo_cred_alloc_blank,
f7433243	270	.cred_prepare = tomoyo_cred_prepare,
ee18d64c	271	.cred_transfer = tomoyo_cred_transfer,
ec8e6a4e	272	.cred_free = tomoyo_cred_free,
f7433243 KT	273	.bprm_set_creds = tomoyo_bprm_set_creds,
f7433243 KT	274	.bprm_check_security = tomoyo_bprm_check_security,
f7433243 KT	275	.file_fcntl = tomoyo_file_fcntl,
	276	.dentry_open = tomoyo_dentry_open,
	277	.path_truncate = tomoyo_path_truncate,
	278	.path_unlink = tomoyo_path_unlink,
	279	.path_mkdir = tomoyo_path_mkdir,
	280	.path_rmdir = tomoyo_path_rmdir,
	281	.path_symlink = tomoyo_path_symlink,
	282	.path_mknod = tomoyo_path_mknod,
	283	.path_link = tomoyo_path_link,
	284	.path_rename = tomoyo_path_rename,
937bf613 TH	285	.file_ioctl = tomoyo_file_ioctl,
	286	.path_chmod = tomoyo_path_chmod,
	287	.path_chown = tomoyo_path_chown,
	288	.path_chroot = tomoyo_path_chroot,
	289	.sb_mount = tomoyo_sb_mount,
	290	.sb_umount = tomoyo_sb_umount,
	291	.sb_pivotroot = tomoyo_sb_pivotroot,
f7433243 KT	292	};
f7433243 KT	293
fdb8ebb7 TH	294	/* Lock for GC. */
	295	struct srcu_struct tomoyo_ss;
	296
f7433243 KT	297	static int __init tomoyo_init(void)
	298	{
	299	struct cred cred = (struct cred ) current_cred();
	300
	301	if (!security_module_enable(&tomoyo_security_ops))
	302	return 0;
	303	/* register ourselves with the security framework */
fdb8ebb7 TH	304	if (register_security(&tomoyo_security_ops) \|\|
fdb8ebb7 TH	305	init_srcu_struct(&tomoyo_ss))
f7433243 KT	306	panic("Failure registering TOMOYO Linux");
	307	printk(KERN_INFO "TOMOYO Linux initialized\n");
	308	cred->security = &tomoyo_kernel_domain;
1581e7dd	309	tomoyo_realpath_init();
f7433243 KT	310	return 0;
	311	}
	312
	313	security_initcall(tomoyo_init);