[deliverable/linux.git] / security / tomoyo / tomoyo.c

/*
 * security/tomoyo/tomoyo.c
 *
 * LSM hooks for TOMOYO Linux.
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 */

#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.
	 */
	return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY);
}

static int tomoyo_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
	struct path path = { mnt, dentry };
	return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, &path);
}

static int tomoyo_path_truncate(struct path *path)
{
	return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path);
}

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

static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
			     int mode)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
				       mode & S_IALLUGO);
}

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

static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
			       const char *old_name)
{
	struct path path = { parent->mnt, dentry };
	return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &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;
	const unsigned int perm = mode & S_IALLUGO;

	switch (mode & S_IFMT) {
	case S_IFCHR:
		type = TOMOYO_TYPE_MKCHAR;
		break;
	case S_IFBLK:
		type = TOMOYO_TYPE_MKBLOCK;
		break;
	default:
		goto no_dev;
	}
	return tomoyo_mkdev_perm(type, &path, perm, dev);
 no_dev:
	switch (mode & S_IFMT) {
	case S_IFIFO:
		type = TOMOYO_TYPE_MKFIFO;
		break;
	case S_IFSOCK:
		type = TOMOYO_TYPE_MKSOCK;
		break;
	}
	return tomoyo_path_number_perm(type, &path, perm);
}

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_path2_perm(TOMOYO_TYPE_LINK, &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_path2_perm(TOMOYO_TYPE_RENAME, &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 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
					    O_WRONLY | (arg & O_APPEND));
}

static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
{
	int flags = f->f_flags;
	/* 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_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
}

static int tomoyo_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
			     mode_t mode)
{
	struct path path = { mnt, dentry };
	return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, &path,
				       mode & S_IALLUGO);
}

static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
{
	int error = 0;
	if (uid != (uid_t) -1)
		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, uid);
	if (!error && gid != (gid_t) -1)
		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, gid);
	return error;
}

static int tomoyo_path_chroot(struct path *path)
{
	return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path);
}

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

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

static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
{
	return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, 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,
	.inode_getattr       = tomoyo_inode_getattr,
	.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_mm_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	*
c3ef1500	6	* Copyright (C) 2005-2010 NTT DATA CORPORATION
f7433243 KT	7	*/
	8
	9	#include <linux/security.h>
	10	#include "common.h"
f7433243	11
ee18d64c DH	12	static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
	13	{
	14	new->security = NULL;
	15	return 0;
	16	}
	17
f7433243 KT	18	static int tomoyo_cred_prepare(struct cred new, const struct cred old,
	19	gfp_t gfp)
	20	{
ec8e6a4e TH	21	struct tomoyo_domain_info *domain = old->security;
	22	new->security = domain;
	23	if (domain)
	24	atomic_inc(&domain->users);
f7433243 KT	25	return 0;
	26	}
	27
ee18d64c DH	28	static void tomoyo_cred_transfer(struct cred new, const struct cred old)
ee18d64c DH	29	{
ec8e6a4e TH	30	tomoyo_cred_prepare(new, old, 0);
	31	}
	32
	33	static void tomoyo_cred_free(struct cred *cred)
	34	{
	35	struct tomoyo_domain_info *domain = cred->security;
	36	if (domain)
	37	atomic_dec(&domain->users);
ee18d64c DH	38	}
ee18d64c DH	39
f7433243 KT	40	static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
f7433243 KT	41	{
b1338d19 HRK	42	int rc;
	43
	44	rc = cap_bprm_set_creds(bprm);
	45	if (rc)
	46	return rc;
	47
f7433243 KT	48	/*
	49	* Do only if this function is called for the first time of an execve
	50	* operation.
	51	*/
	52	if (bprm->cred_prepared)
	53	return 0;
	54	/*
	55	* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	56	* for the first time.
	57	*/
	58	if (!tomoyo_policy_loaded)
	59	tomoyo_load_policy(bprm->filename);
ec8e6a4e TH	60	/*
	61	* Release reference to "struct tomoyo_domain_info" stored inside
	62	* "bprm->cred->security". New reference to "struct tomoyo_domain_info"
	63	* stored inside "bprm->cred->security" will be acquired later inside
	64	* tomoyo_find_next_domain().
	65	*/
	66	atomic_dec(&((struct tomoyo_domain_info *)
	67	bprm->cred->security)->users);
f7433243 KT	68	/*
	69	* Tell tomoyo_bprm_check_security() is called for the first time of an
	70	* execve operation.
	71	*/
	72	bprm->cred->security = NULL;
	73	return 0;
	74	}
	75
	76	static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
	77	{
	78	struct tomoyo_domain_info *domain = bprm->cred->security;
	79
	80	/*
	81	* Execute permission is checked against pathname passed to do_execve()
	82	* using current domain.
	83	*/
fdb8ebb7	84	if (!domain) {
fdb8ebb7 TH	85	const int idx = tomoyo_read_lock();
	86	const int err = tomoyo_find_next_domain(bprm);
	87	tomoyo_read_unlock(idx);
	88	return err;
	89	}
f7433243 KT	90	/*
f7433243 KT	91	* Read permission is checked against interpreters using next domain.
f7433243	92	*/
6d125529	93	return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY);
f7433243 KT	94	}
f7433243 KT	95
7c75964f TH	96	static int tomoyo_inode_getattr(struct vfsmount mnt, struct dentry dentry)
	97	{
	98	struct path path = { mnt, dentry };
	99	return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, &path);
	100	}
	101
ea0d3ab2	102	static int tomoyo_path_truncate(struct path *path)
f7433243	103	{
97d6931e	104	return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path);
f7433243 KT	105	}
	106
	107	static int tomoyo_path_unlink(struct path parent, struct dentry dentry)
	108	{
	109	struct path path = { parent->mnt, dentry };
97d6931e	110	return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path);
f7433243 KT	111	}
	112
	113	static int tomoyo_path_mkdir(struct path parent, struct dentry dentry,
	114	int mode)
	115	{
	116	struct path path = { parent->mnt, dentry };
a1f9bb6a TH	117	return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
a1f9bb6a TH	118	mode & S_IALLUGO);
f7433243 KT	119	}
	120
	121	static int tomoyo_path_rmdir(struct path parent, struct dentry dentry)
	122	{
	123	struct path path = { parent->mnt, dentry };
97d6931e	124	return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path);
f7433243 KT	125	}
	126
	127	static int tomoyo_path_symlink(struct path parent, struct dentry dentry,
	128	const char *old_name)
	129	{
	130	struct path path = { parent->mnt, dentry };
97d6931e	131	return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path);
f7433243 KT	132	}
	133
	134	static int tomoyo_path_mknod(struct path parent, struct dentry dentry,
	135	int mode, unsigned int dev)
	136	{
	137	struct path path = { parent->mnt, dentry };
7ef61233	138	int type = TOMOYO_TYPE_CREATE;
a1f9bb6a	139	const unsigned int perm = mode & S_IALLUGO;
f7433243 KT	140
	141	switch (mode & S_IFMT) {
	142	case S_IFCHR:
7ef61233	143	type = TOMOYO_TYPE_MKCHAR;
f7433243 KT	144	break;
f7433243 KT	145	case S_IFBLK:
7ef61233	146	type = TOMOYO_TYPE_MKBLOCK;
f7433243	147	break;
a1f9bb6a TH	148	default:
	149	goto no_dev;
	150	}
75093152	151	return tomoyo_mkdev_perm(type, &path, perm, dev);
a1f9bb6a TH	152	no_dev:
a1f9bb6a TH	153	switch (mode & S_IFMT) {
f7433243	154	case S_IFIFO:
7ef61233	155	type = TOMOYO_TYPE_MKFIFO;
f7433243 KT	156	break;
f7433243 KT	157	case S_IFSOCK:
7ef61233	158	type = TOMOYO_TYPE_MKSOCK;
f7433243 KT	159	break;
f7433243 KT	160	}
a1f9bb6a	161	return tomoyo_path_number_perm(type, &path, perm);
f7433243 KT	162	}
	163
	164	static int tomoyo_path_link(struct dentry old_dentry, struct path new_dir,
	165	struct dentry *new_dentry)
	166	{
	167	struct path path1 = { new_dir->mnt, old_dentry };
	168	struct path path2 = { new_dir->mnt, new_dentry };
97d6931e	169	return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
f7433243 KT	170	}
	171
	172	static int tomoyo_path_rename(struct path *old_parent,
	173	struct dentry *old_dentry,
	174	struct path *new_parent,
	175	struct dentry *new_dentry)
	176	{
	177	struct path path1 = { old_parent->mnt, old_dentry };
	178	struct path path2 = { new_parent->mnt, new_dentry };
97d6931e	179	return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
f7433243 KT	180	}
	181
	182	static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
	183	unsigned long arg)
	184	{
7c75964f TH	185	if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
	186	return 0;
	187	return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
	188	O_WRONLY \| (arg & O_APPEND));
f7433243 KT	189	}
	190
	191	static int tomoyo_dentry_open(struct file f, const struct cred cred)
	192	{
	193	int flags = f->f_flags;
f7433243 KT	194	/* Don't check read permission here if called from do_execve(). */
	195	if (current->in_execve)
	196	return 0;
	197	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
	198	}
	199
937bf613 TH	200	static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
	201	unsigned long arg)
	202	{
a1f9bb6a	203	return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
937bf613 TH	204	}
	205
	206	static int tomoyo_path_chmod(struct dentry dentry, struct vfsmount mnt,
	207	mode_t mode)
	208	{
	209	struct path path = { mnt, dentry };
a1f9bb6a TH	210	return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, &path,
a1f9bb6a TH	211	mode & S_IALLUGO);
937bf613 TH	212	}
	213
	214	static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
	215	{
	216	int error = 0;
	217	if (uid != (uid_t) -1)
a1f9bb6a	218	error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, uid);
937bf613	219	if (!error && gid != (gid_t) -1)
a1f9bb6a	220	error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, gid);
937bf613 TH	221	return error;
	222	}
	223
	224	static int tomoyo_path_chroot(struct path *path)
	225	{
97d6931e	226	return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path);
937bf613 TH	227	}
	228
	229	static int tomoyo_sb_mount(char dev_name, struct path path,
	230	char type, unsigned long flags, void data)
	231	{
2106ccd9	232	return tomoyo_mount_permission(dev_name, path, type, flags, data);
937bf613 TH	233	}
	234
	235	static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
	236	{
	237	struct path path = { mnt, mnt->mnt_root };
97d6931e	238	return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path);
937bf613 TH	239	}
	240
	241	static int tomoyo_sb_pivotroot(struct path old_path, struct path new_path)
	242	{
97d6931e	243	return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
937bf613 TH	244	}
937bf613 TH	245
c3fa109a TH	246	/*
	247	* tomoyo_security_ops is a "struct security_operations" which is used for
	248	* registering TOMOYO.
	249	*/
f7433243 KT	250	static struct security_operations tomoyo_security_ops = {
f7433243 KT	251	.name = "tomoyo",
ee18d64c	252	.cred_alloc_blank = tomoyo_cred_alloc_blank,
f7433243	253	.cred_prepare = tomoyo_cred_prepare,
ee18d64c	254	.cred_transfer = tomoyo_cred_transfer,
ec8e6a4e	255	.cred_free = tomoyo_cred_free,
f7433243 KT	256	.bprm_set_creds = tomoyo_bprm_set_creds,
f7433243 KT	257	.bprm_check_security = tomoyo_bprm_check_security,
f7433243 KT	258	.file_fcntl = tomoyo_file_fcntl,
	259	.dentry_open = tomoyo_dentry_open,
	260	.path_truncate = tomoyo_path_truncate,
	261	.path_unlink = tomoyo_path_unlink,
	262	.path_mkdir = tomoyo_path_mkdir,
	263	.path_rmdir = tomoyo_path_rmdir,
	264	.path_symlink = tomoyo_path_symlink,
	265	.path_mknod = tomoyo_path_mknod,
	266	.path_link = tomoyo_path_link,
	267	.path_rename = tomoyo_path_rename,
7c75964f	268	.inode_getattr = tomoyo_inode_getattr,
937bf613 TH	269	.file_ioctl = tomoyo_file_ioctl,
	270	.path_chmod = tomoyo_path_chmod,
	271	.path_chown = tomoyo_path_chown,
	272	.path_chroot = tomoyo_path_chroot,
	273	.sb_mount = tomoyo_sb_mount,
	274	.sb_umount = tomoyo_sb_umount,
	275	.sb_pivotroot = tomoyo_sb_pivotroot,
f7433243 KT	276	};
f7433243 KT	277
fdb8ebb7 TH	278	/* Lock for GC. */
	279	struct srcu_struct tomoyo_ss;
	280
f7433243 KT	281	static int __init tomoyo_init(void)
	282	{
	283	struct cred cred = (struct cred ) current_cred();
	284
	285	if (!security_module_enable(&tomoyo_security_ops))
	286	return 0;
	287	/* register ourselves with the security framework */
fdb8ebb7 TH	288	if (register_security(&tomoyo_security_ops) \|\|
fdb8ebb7 TH	289	init_srcu_struct(&tomoyo_ss))
f7433243 KT	290	panic("Failure registering TOMOYO Linux");
	291	printk(KERN_INFO "TOMOYO Linux initialized\n");
	292	cred->security = &tomoyo_kernel_domain;
c3ef1500	293	tomoyo_mm_init();
f7433243 KT	294	return 0;
	295	}
	296
	297	security_initcall(tomoyo_init);