TOMOYO: Rename directives.
[linux-2.6.git] / security / tomoyo / tomoyo.c
1 /*
2  * security/tomoyo/tomoyo.c
3  *
4  * LSM hooks for TOMOYO Linux.
5  *
6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
7  */
8
9 #include <linux/security.h>
10 #include "common.h"
11
12 static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
13 {
14         new->security = NULL;
15         return 0;
16 }
17
18 static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
19                                gfp_t gfp)
20 {
21         struct tomoyo_domain_info *domain = old->security;
22         new->security = domain;
23         if (domain)
24                 atomic_inc(&domain->users);
25         return 0;
26 }
27
28 static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
29 {
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);
38 }
39
40 static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
41 {
42         int rc;
43
44         rc = cap_bprm_set_creds(bprm);
45         if (rc)
46                 return rc;
47
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);
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);
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          */
84         if (!domain) {
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         }
90         /*
91          * Read permission is checked against interpreters using next domain.
92          */
93         return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY);
94 }
95
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
102 static int tomoyo_path_truncate(struct path *path)
103 {
104         return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path);
105 }
106
107 static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
108 {
109         struct path path = { parent->mnt, dentry };
110         return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path);
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 };
117         return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
118                                        mode & S_IALLUGO);
119 }
120
121 static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
122 {
123         struct path path = { parent->mnt, dentry };
124         return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path);
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 };
131         return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path);
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 };
138         int type = TOMOYO_TYPE_CREATE;
139         const unsigned int perm = mode & S_IALLUGO;
140
141         switch (mode & S_IFMT) {
142         case S_IFCHR:
143                 type = TOMOYO_TYPE_MKCHAR;
144                 break;
145         case S_IFBLK:
146                 type = TOMOYO_TYPE_MKBLOCK;
147                 break;
148         default:
149                 goto no_dev;
150         }
151         return tomoyo_mkdev_perm(type, &path, perm, dev);
152  no_dev:
153         switch (mode & S_IFMT) {
154         case S_IFIFO:
155                 type = TOMOYO_TYPE_MKFIFO;
156                 break;
157         case S_IFSOCK:
158                 type = TOMOYO_TYPE_MKSOCK;
159                 break;
160         }
161         return tomoyo_path_number_perm(type, &path, perm);
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 };
169         return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
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 };
179         return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
180 }
181
182 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
183                              unsigned long arg)
184 {
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));
189 }
190
191 static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
192 {
193         int flags = f->f_flags;
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
200 static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
201                              unsigned long arg)
202 {
203         return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
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 };
210         return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, &path,
211                                        mode & S_IALLUGO);
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)
218                 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, uid);
219         if (!error && gid != (gid_t) -1)
220                 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, gid);
221         return error;
222 }
223
224 static int tomoyo_path_chroot(struct path *path)
225 {
226         return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path);
227 }
228
229 static int tomoyo_sb_mount(char *dev_name, struct path *path,
230                            char *type, unsigned long flags, void *data)
231 {
232         return tomoyo_mount_permission(dev_name, path, type, flags, data);
233 }
234
235 static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
236 {
237         struct path path = { mnt, mnt->mnt_root };
238         return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path);
239 }
240
241 static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
242 {
243         return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
244 }
245
246 /*
247  * tomoyo_security_ops is a "struct security_operations" which is used for
248  * registering TOMOYO.
249  */
250 static struct security_operations tomoyo_security_ops = {
251         .name                = "tomoyo",
252         .cred_alloc_blank    = tomoyo_cred_alloc_blank,
253         .cred_prepare        = tomoyo_cred_prepare,
254         .cred_transfer       = tomoyo_cred_transfer,
255         .cred_free           = tomoyo_cred_free,
256         .bprm_set_creds      = tomoyo_bprm_set_creds,
257         .bprm_check_security = tomoyo_bprm_check_security,
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,
268         .inode_getattr       = tomoyo_inode_getattr,
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,
276 };
277
278 /* Lock for GC. */
279 struct srcu_struct tomoyo_ss;
280
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 */
288         if (register_security(&tomoyo_security_ops) ||
289             init_srcu_struct(&tomoyo_ss))
290                 panic("Failure registering TOMOYO Linux");
291         printk(KERN_INFO "TOMOYO Linux initialized\n");
292         cred->security = &tomoyo_kernel_domain;
293         tomoyo_mm_init();
294         return 0;
295 }
296
297 security_initcall(tomoyo_init);