tomoyo.c revision 6d125529c6cbfe570ce3bf9a0728548f087499da 
1/*
2 * security/tomoyo/tomoyo.c
3 *
4 * LSM hooks for TOMOYO Linux.
5 *
6 * Copyright (C) 2005-2009  NTT DATA CORPORATION
7 *
8 * Version: 2.2.0   2009/04/01
9 *
10 */
11
12#include <linux/security.h>
13#include "common.h"
14#include "tomoyo.h"
15#include "realpath.h"
16
17static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
18{
19	new->security = NULL;
20	return 0;
21}
22
23static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
24			       gfp_t gfp)
25{
26	/*
27	 * Since "struct tomoyo_domain_info *" is a sharable pointer,
28	 * we don't need to duplicate.
29	 */
30	new->security = old->security;
31	return 0;
32}
33
34static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
35{
36	/*
37	 * Since "struct tomoyo_domain_info *" is a sharable pointer,
38	 * we don't need to duplicate.
39	 */
40	new->security = old->security;
41}
42
43static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
44{
45	int rc;
46
47	rc = cap_bprm_set_creds(bprm);
48	if (rc)
49		return rc;
50
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);
63	/*
64	 * Tell tomoyo_bprm_check_security() is called for the first time of an
65	 * execve operation.
66	 */
67	bprm->cred->security = NULL;
68	return 0;
69}
70
71static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
72{
73	struct tomoyo_domain_info *domain = bprm->cred->security;
74
75	/*
76	 * Execute permission is checked against pathname passed to do_execve()
77	 * using current domain.
78	 */
79	if (!domain)
80		return tomoyo_find_next_domain(bprm);
81	/*
82	 * Read permission is checked against interpreters using next domain.
83	 */
84	return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY);
85}
86
87static int tomoyo_path_truncate(struct path *path, loff_t length,
88				unsigned int time_attrs)
89{
90	return tomoyo_check_1path_perm(tomoyo_domain(),
91				       TOMOYO_TYPE_TRUNCATE_ACL,
92				       path);
93}
94
95static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
96{
97	struct path path = { parent->mnt, dentry };
98	return tomoyo_check_1path_perm(tomoyo_domain(),
99				       TOMOYO_TYPE_UNLINK_ACL,
100				       &path);
101}
102
103static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
104			     int mode)
105{
106	struct path path = { parent->mnt, dentry };
107	return tomoyo_check_1path_perm(tomoyo_domain(),
108				       TOMOYO_TYPE_MKDIR_ACL,
109				       &path);
110}
111
112static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
113{
114	struct path path = { parent->mnt, dentry };
115	return tomoyo_check_1path_perm(tomoyo_domain(),
116				       TOMOYO_TYPE_RMDIR_ACL,
117				       &path);
118}
119
120static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
121			       const char *old_name)
122{
123	struct path path = { parent->mnt, dentry };
124	return tomoyo_check_1path_perm(tomoyo_domain(),
125				       TOMOYO_TYPE_SYMLINK_ACL,
126				       &path);
127}
128
129static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
130			     int mode, unsigned int dev)
131{
132	struct path path = { parent->mnt, dentry };
133	int type = TOMOYO_TYPE_CREATE_ACL;
134
135	switch (mode & S_IFMT) {
136	case S_IFCHR:
137		type = TOMOYO_TYPE_MKCHAR_ACL;
138		break;
139	case S_IFBLK:
140		type = TOMOYO_TYPE_MKBLOCK_ACL;
141		break;
142	case S_IFIFO:
143		type = TOMOYO_TYPE_MKFIFO_ACL;
144		break;
145	case S_IFSOCK:
146		type = TOMOYO_TYPE_MKSOCK_ACL;
147		break;
148	}
149	return tomoyo_check_1path_perm(tomoyo_domain(),
150				       type, &path);
151}
152
153static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
154			    struct dentry *new_dentry)
155{
156	struct path path1 = { new_dir->mnt, old_dentry };
157	struct path path2 = { new_dir->mnt, new_dentry };
158	return tomoyo_check_2path_perm(tomoyo_domain(),
159				       TOMOYO_TYPE_LINK_ACL,
160				       &path1, &path2);
161}
162
163static int tomoyo_path_rename(struct path *old_parent,
164			      struct dentry *old_dentry,
165			      struct path *new_parent,
166			      struct dentry *new_dentry)
167{
168	struct path path1 = { old_parent->mnt, old_dentry };
169	struct path path2 = { new_parent->mnt, new_dentry };
170	return tomoyo_check_2path_perm(tomoyo_domain(),
171				       TOMOYO_TYPE_RENAME_ACL,
172				       &path1, &path2);
173}
174
175static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
176			     unsigned long arg)
177{
178	if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))
179		return tomoyo_check_rewrite_permission(tomoyo_domain(), file);
180	return 0;
181}
182
183static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
184{
185	int flags = f->f_flags;
186	/* Don't check read permission here if called from do_execve(). */
187	if (current->in_execve)
188		return 0;
189	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
190}
191
192/*
193 * tomoyo_security_ops is a "struct security_operations" which is used for
194 * registering TOMOYO.
195 */
196static struct security_operations tomoyo_security_ops = {
197	.name                = "tomoyo",
198	.cred_alloc_blank    = tomoyo_cred_alloc_blank,
199	.cred_prepare        = tomoyo_cred_prepare,
200	.cred_transfer	     = tomoyo_cred_transfer,
201	.bprm_set_creds      = tomoyo_bprm_set_creds,
202	.bprm_check_security = tomoyo_bprm_check_security,
203	.file_fcntl          = tomoyo_file_fcntl,
204	.dentry_open         = tomoyo_dentry_open,
205	.path_truncate       = tomoyo_path_truncate,
206	.path_unlink         = tomoyo_path_unlink,
207	.path_mkdir          = tomoyo_path_mkdir,
208	.path_rmdir          = tomoyo_path_rmdir,
209	.path_symlink        = tomoyo_path_symlink,
210	.path_mknod          = tomoyo_path_mknod,
211	.path_link           = tomoyo_path_link,
212	.path_rename         = tomoyo_path_rename,
213};
214
215static int __init tomoyo_init(void)
216{
217	struct cred *cred = (struct cred *) current_cred();
218
219	if (!security_module_enable(&tomoyo_security_ops))
220		return 0;
221	/* register ourselves with the security framework */
222	if (register_security(&tomoyo_security_ops))
223		panic("Failure registering TOMOYO Linux");
224	printk(KERN_INFO "TOMOYO Linux initialized\n");
225	cred->security = &tomoyo_kernel_domain;
226	tomoyo_realpath_init();
227	return 0;
228}
229
230security_initcall(tomoyo_init);
231