[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"
#include "tomoyo.h"
#include "realpath.h"

static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
			       gfp_t gfp)
{
	/*
	 * Since "struct tomoyo_domain_info *" is a sharable pointer,
	 * we don't need to duplicate.
	 */
	new->security = old->security;
	return 0;
}

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);
	/*
	 * 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) {
		struct tomoyo_domain_info *next_domain = NULL;
		int retval = tomoyo_find_next_domain(bprm, &next_domain);

		if (!retval)
			bprm->cred->security = next_domain;
		return retval;
	}
	/*
	 * 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);
}

#ifdef CONFIG_SYSCTL

static int tomoyo_prepend(char **buffer, int *buflen, const char *str)
{
	int namelen = strlen(str);

	if (*buflen < namelen)
		return -ENOMEM;
	*buflen -= namelen;
	*buffer -= namelen;
	memcpy(*buffer, str, namelen);
	return 0;
}

/**
 * tomoyo_sysctl_path - return the realpath of a ctl_table.
 * @table: pointer to "struct ctl_table".
 *
 * Returns realpath(3) of the @table on success.
 * Returns NULL on failure.
 *
 * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
 * if this function didn't return NULL.
 */
static char *tomoyo_sysctl_path(struct ctl_table *table)
{
	int buflen = TOMOYO_MAX_PATHNAME_LEN;
	char *buf = tomoyo_alloc(buflen);
	char *end = buf + buflen;
	int error = -ENOMEM;

	if (!buf)
		return NULL;

	*--end = '\0';
	buflen--;
	while (table) {
		char num[32];
		const char *sp = table->procname;

		if (!sp) {
			memset(num, 0, sizeof(num));
			snprintf(num, sizeof(num) - 1, "=%d=", table->ctl_name);
			sp = num;
		}
		if (tomoyo_prepend(&end, &buflen, sp) ||
		    tomoyo_prepend(&end, &buflen, "/"))
			goto out;
		table = table->parent;
	}
	if (tomoyo_prepend(&end, &buflen, "/proc/sys"))
		goto out;
	error = tomoyo_encode(buf, end - buf, end);
 out:
	if (!error)
		return buf;
	tomoyo_free(buf);
	return NULL;
}

static int tomoyo_sysctl(struct ctl_table *table, int op)
{
	int error;
	char *name;

	op &= MAY_READ | MAY_WRITE;
	if (!op)
		return 0;
	name = tomoyo_sysctl_path(table);
	if (!name)
		return -ENOMEM;
	error = tomoyo_check_file_perm(tomoyo_domain(), name, op);
	tomoyo_free(name);
	return error;
}
#endif

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 struct security_operations tomoyo_security_ops = {
	.name                = "tomoyo",
	.cred_prepare        = tomoyo_cred_prepare,
	.bprm_set_creds      = tomoyo_bprm_set_creds,
	.bprm_check_security = tomoyo_bprm_check_security,
#ifdef CONFIG_SYSCTL
	.sysctl              = tomoyo_sysctl,
#endif
	.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,
};

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))
		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"
	14	#include "tomoyo.h"
	15	#include "realpath.h"
	16
	17	static int tomoyo_cred_prepare(struct cred new, const struct cred old,
	18	gfp_t gfp)
	19	{
	20	/*
	21	* Since "struct tomoyo_domain_info *" is a sharable pointer,
	22	* we don't need to duplicate.
	23	*/
	24	new->security = old->security;
	25	return 0;
	26	}
	27
	28	static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
	29	{
b1338d19 HRK	30	int rc;
	31
	32	rc = cap_bprm_set_creds(bprm);
	33	if (rc)
	34	return rc;
	35
f7433243 KT	36	/*
	37	* Do only if this function is called for the first time of an execve
	38	* operation.
	39	*/
	40	if (bprm->cred_prepared)
	41	return 0;
	42	/*
	43	* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	44	* for the first time.
	45	*/
	46	if (!tomoyo_policy_loaded)
	47	tomoyo_load_policy(bprm->filename);
	48	/*
	49	* Tell tomoyo_bprm_check_security() is called for the first time of an
	50	* execve operation.
	51	*/
	52	bprm->cred->security = NULL;
	53	return 0;
	54	}
	55
	56	static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
	57	{
	58	struct tomoyo_domain_info *domain = bprm->cred->security;
	59
	60	/*
	61	* Execute permission is checked against pathname passed to do_execve()
	62	* using current domain.
	63	*/
	64	if (!domain) {
	65	struct tomoyo_domain_info *next_domain = NULL;
	66	int retval = tomoyo_find_next_domain(bprm, &next_domain);
	67
	68	if (!retval)
	69	bprm->cred->security = next_domain;
	70	return retval;
	71	}
	72	/*
	73	* Read permission is checked against interpreters using next domain.
	74	* '1' is the result of open_to_namei_flags(O_RDONLY).
	75	*/
	76	return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
	77	}
	78
	79	#ifdef CONFIG_SYSCTL
	80
	81	static int tomoyo_prepend(char *buffer, int buflen, const char *str)
	82	{
	83	int namelen = strlen(str);
	84
	85	if (*buflen < namelen)
	86	return -ENOMEM;
	87	*buflen -= namelen;
	88	*buffer -= namelen;
	89	memcpy(*buffer, str, namelen);
	90	return 0;
	91	}
	92
	93	/**
	94	* tomoyo_sysctl_path - return the realpath of a ctl_table.
	95	* @table: pointer to "struct ctl_table".
	96	*
	97	* Returns realpath(3) of the @table on success.
	98	* Returns NULL on failure.
	99	*
100	* This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
101	* if this function didn't return NULL.
102	*/
103	static char tomoyo_sysctl_path(struct ctl_table table)
104	{
105	int buflen = TOMOYO_MAX_PATHNAME_LEN;
106	char *buf = tomoyo_alloc(buflen);
107	char *end = buf + buflen;
108	int error = -ENOMEM;
109
110	if (!buf)
111	return NULL;
112
113	*--end = '\0';
114	buflen--;
115	while (table) {
35d50e60	116	char num[32];
f7433243 KT	117	const char *sp = table->procname;
	118
	119	if (!sp) {
35d50e60 TH	120	memset(num, 0, sizeof(num));
	121	snprintf(num, sizeof(num) - 1, "=%d=", table->ctl_name);
	122	sp = num;
f7433243 KT	123	}
	124	if (tomoyo_prepend(&end, &buflen, sp) \|\|
	125	tomoyo_prepend(&end, &buflen, "/"))
	126	goto out;
	127	table = table->parent;
	128	}
	129	if (tomoyo_prepend(&end, &buflen, "/proc/sys"))
	130	goto out;
	131	error = tomoyo_encode(buf, end - buf, end);
	132	out:
	133	if (!error)
	134	return buf;
	135	tomoyo_free(buf);
	136	return NULL;
	137	}
	138
	139	static int tomoyo_sysctl(struct ctl_table *table, int op)
	140	{
	141	int error;
	142	char *name;
	143
	144	op &= MAY_READ \| MAY_WRITE;
	145	if (!op)
	146	return 0;
	147	name = tomoyo_sysctl_path(table);
	148	if (!name)
	149	return -ENOMEM;
	150	error = tomoyo_check_file_perm(tomoyo_domain(), name, op);
	151	tomoyo_free(name);
	152	return error;
	153	}
	154	#endif
	155
	156	static int tomoyo_path_truncate(struct path *path, loff_t length,
	157	unsigned int time_attrs)
	158	{
	159	return tomoyo_check_1path_perm(tomoyo_domain(),
	160	TOMOYO_TYPE_TRUNCATE_ACL,
	161	path);
	162	}
	163
	164	static int tomoyo_path_unlink(struct path parent, struct dentry dentry)
	165	{
	166	struct path path = { parent->mnt, dentry };
	167	return tomoyo_check_1path_perm(tomoyo_domain(),
	168	TOMOYO_TYPE_UNLINK_ACL,
	169	&path);
	170	}
	171
	172	static int tomoyo_path_mkdir(struct path parent, struct dentry dentry,
	173	int mode)
	174	{
	175	struct path path = { parent->mnt, dentry };
	176	return tomoyo_check_1path_perm(tomoyo_domain(),
	177	TOMOYO_TYPE_MKDIR_ACL,
	178	&path);
	179	}
	180
	181	static int tomoyo_path_rmdir(struct path parent, struct dentry dentry)
	182	{
	183	struct path path = { parent->mnt, dentry };
	184	return tomoyo_check_1path_perm(tomoyo_domain(),
	185	TOMOYO_TYPE_RMDIR_ACL,
	186	&path);
187	}
188
189	static int tomoyo_path_symlink(struct path parent, struct dentry dentry,
190	const char *old_name)
191	{
192	struct path path = { parent->mnt, dentry };
193	return tomoyo_check_1path_perm(tomoyo_domain(),
194	TOMOYO_TYPE_SYMLINK_ACL,
195	&path);
196	}
197
198	static int tomoyo_path_mknod(struct path parent, struct dentry dentry,
199	int mode, unsigned int dev)
200	{
201	struct path path = { parent->mnt, dentry };
202	int type = TOMOYO_TYPE_CREATE_ACL;
203
204	switch (mode & S_IFMT) {
205	case S_IFCHR:
206	type = TOMOYO_TYPE_MKCHAR_ACL;
207	break;
208	case S_IFBLK:
209	type = TOMOYO_TYPE_MKBLOCK_ACL;
210	break;
211	case S_IFIFO:
212	type = TOMOYO_TYPE_MKFIFO_ACL;
213	break;
214	case S_IFSOCK:
215	type = TOMOYO_TYPE_MKSOCK_ACL;
216	break;
217	}
218	return tomoyo_check_1path_perm(tomoyo_domain(),
219	type, &path);
220	}
221
222	static int tomoyo_path_link(struct dentry old_dentry, struct path new_dir,
223	struct dentry *new_dentry)
224	{
225	struct path path1 = { new_dir->mnt, old_dentry };
226	struct path path2 = { new_dir->mnt, new_dentry };
227	return tomoyo_check_2path_perm(tomoyo_domain(),
228	TOMOYO_TYPE_LINK_ACL,
229	&path1, &path2);
230	}
231
232	static int tomoyo_path_rename(struct path *old_parent,
233	struct dentry *old_dentry,
234	struct path *new_parent,
235	struct dentry *new_dentry)
236	{
237	struct path path1 = { old_parent->mnt, old_dentry };
238	struct path path2 = { new_parent->mnt, new_dentry };
239	return tomoyo_check_2path_perm(tomoyo_domain(),
240	TOMOYO_TYPE_RENAME_ACL,
241	&path1, &path2);
242	}
243
244	static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
245	unsigned long arg)
246	{
247	if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))
248	return tomoyo_check_rewrite_permission(tomoyo_domain(), file);
249	return 0;
250	}
251
252	static int tomoyo_dentry_open(struct file f, const struct cred cred)
253	{
254	int flags = f->f_flags;
255
256	if ((flags + 1) & O_ACCMODE)
257	flags++;
258	flags \|= f->f_flags & (O_APPEND \| O_TRUNC);
259	/* Don't check read permission here if called from do_execve(). */
260	if (current->in_execve)
261	return 0;
262	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
263	}
264
265	static struct security_operations tomoyo_security_ops = {
266	.name = "tomoyo",
267	.cred_prepare = tomoyo_cred_prepare,
268	.bprm_set_creds = tomoyo_bprm_set_creds,
269	.bprm_check_security = tomoyo_bprm_check_security,
270	#ifdef CONFIG_SYSCTL
271	.sysctl = tomoyo_sysctl,
272	#endif
273	.file_fcntl = tomoyo_file_fcntl,
274	.dentry_open = tomoyo_dentry_open,
275	.path_truncate = tomoyo_path_truncate,
276	.path_unlink = tomoyo_path_unlink,
277	.path_mkdir = tomoyo_path_mkdir,
278	.path_rmdir = tomoyo_path_rmdir,
279	.path_symlink = tomoyo_path_symlink,
280	.path_mknod = tomoyo_path_mknod,
281	.path_link = tomoyo_path_link,
282	.path_rename = tomoyo_path_rename,
283	};
284
285	static int __init tomoyo_init(void)
286	{
287	struct cred cred = (struct cred ) current_cred();
288
289	if (!security_module_enable(&tomoyo_security_ops))
290	return 0;
291	/* register ourselves with the security framework */
292	if (register_security(&tomoyo_security_ops))
293	panic("Failure registering TOMOYO Linux");
294	printk(KERN_INFO "TOMOYO Linux initialized\n");
295	cred->security = &tomoyo_kernel_domain;
1581e7dd	296	tomoyo_realpath_init();
f7433243 KT	297	return 0;
	298	}
	299
	300	security_initcall(tomoyo_init);