compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
[sfrench/cifs-2.6.git] / security / tomoyo / tomoyo.c
1 /*
2  * security/tomoyo/tomoyo.c
3  *
4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
5  */
6
7 #include <linux/security.h>
8 #include "common.h"
9
10 /**
11  * tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().
12  *
13  * @new: Pointer to "struct cred".
14  * @gfp: Memory allocation flags.
15  *
16  * Returns 0.
17  */
18 static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
19 {
20         new->security = NULL;
21         return 0;
22 }
23
24 /**
25  * tomoyo_cred_prepare - Target for security_prepare_creds().
26  *
27  * @new: Pointer to "struct cred".
28  * @old: Pointer to "struct cred".
29  * @gfp: Memory allocation flags.
30  *
31  * Returns 0.
32  */
33 static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
34                                gfp_t gfp)
35 {
36         struct tomoyo_domain_info *domain = old->security;
37         new->security = domain;
38         if (domain)
39                 atomic_inc(&domain->users);
40         return 0;
41 }
42
43 /**
44  * tomoyo_cred_transfer - Target for security_transfer_creds().
45  *
46  * @new: Pointer to "struct cred".
47  * @old: Pointer to "struct cred".
48  */
49 static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
50 {
51         tomoyo_cred_prepare(new, old, 0);
52 }
53
54 /**
55  * tomoyo_cred_free - Target for security_cred_free().
56  *
57  * @cred: Pointer to "struct cred".
58  */
59 static void tomoyo_cred_free(struct cred *cred)
60 {
61         struct tomoyo_domain_info *domain = cred->security;
62         if (domain)
63                 atomic_dec(&domain->users);
64 }
65
66 /**
67  * tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
68  *
69  * @bprm: Pointer to "struct linux_binprm".
70  *
71  * Returns 0 on success, negative value otherwise.
72  */
73 static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
74 {
75         int rc;
76
77         rc = cap_bprm_set_creds(bprm);
78         if (rc)
79                 return rc;
80
81         /*
82          * Do only if this function is called for the first time of an execve
83          * operation.
84          */
85         if (bprm->cred_prepared)
86                 return 0;
87 #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
88         /*
89          * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
90          * for the first time.
91          */
92         if (!tomoyo_policy_loaded)
93                 tomoyo_load_policy(bprm->filename);
94 #endif
95         /*
96          * Release reference to "struct tomoyo_domain_info" stored inside
97          * "bprm->cred->security". New reference to "struct tomoyo_domain_info"
98          * stored inside "bprm->cred->security" will be acquired later inside
99          * tomoyo_find_next_domain().
100          */
101         atomic_dec(&((struct tomoyo_domain_info *)
102                      bprm->cred->security)->users);
103         /*
104          * Tell tomoyo_bprm_check_security() is called for the first time of an
105          * execve operation.
106          */
107         bprm->cred->security = NULL;
108         return 0;
109 }
110
111 /**
112  * tomoyo_bprm_check_security - Target for security_bprm_check().
113  *
114  * @bprm: Pointer to "struct linux_binprm".
115  *
116  * Returns 0 on success, negative value otherwise.
117  */
118 static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
119 {
120         struct tomoyo_domain_info *domain = bprm->cred->security;
121
122         /*
123          * Execute permission is checked against pathname passed to do_execve()
124          * using current domain.
125          */
126         if (!domain) {
127                 const int idx = tomoyo_read_lock();
128                 const int err = tomoyo_find_next_domain(bprm);
129                 tomoyo_read_unlock(idx);
130                 return err;
131         }
132         /*
133          * Read permission is checked against interpreters using next domain.
134          */
135         return tomoyo_check_open_permission(domain, &bprm->file->f_path,
136                                             O_RDONLY);
137 }
138
139 /**
140  * tomoyo_inode_getattr - Target for security_inode_getattr().
141  *
142  * @mnt:    Pointer to "struct vfsmount".
143  * @dentry: Pointer to "struct dentry".
144  *
145  * Returns 0 on success, negative value otherwise.
146  */
147 static int tomoyo_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
148 {
149         struct path path = { mnt, dentry };
150         return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, &path, NULL);
151 }
152
153 /**
154  * tomoyo_path_truncate - Target for security_path_truncate().
155  *
156  * @path: Pointer to "struct path".
157  *
158  * Returns 0 on success, negative value otherwise.
159  */
160 static int tomoyo_path_truncate(struct path *path)
161 {
162         return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
163 }
164
165 /**
166  * tomoyo_path_unlink - Target for security_path_unlink().
167  *
168  * @parent: Pointer to "struct path".
169  * @dentry: Pointer to "struct dentry".
170  *
171  * Returns 0 on success, negative value otherwise.
172  */
173 static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
174 {
175         struct path path = { parent->mnt, dentry };
176         return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
177 }
178
179 /**
180  * tomoyo_path_mkdir - Target for security_path_mkdir().
181  *
182  * @parent: Pointer to "struct path".
183  * @dentry: Pointer to "struct dentry".
184  * @mode:   DAC permission mode.
185  *
186  * Returns 0 on success, negative value otherwise.
187  */
188 static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
189                              umode_t mode)
190 {
191         struct path path = { parent->mnt, dentry };
192         return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
193                                        mode & S_IALLUGO);
194 }
195
196 /**
197  * tomoyo_path_rmdir - Target for security_path_rmdir().
198  *
199  * @parent: Pointer to "struct path".
200  * @dentry: Pointer to "struct dentry".
201  *
202  * Returns 0 on success, negative value otherwise.
203  */
204 static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
205 {
206         struct path path = { parent->mnt, dentry };
207         return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
208 }
209
210 /**
211  * tomoyo_path_symlink - Target for security_path_symlink().
212  *
213  * @parent:   Pointer to "struct path".
214  * @dentry:   Pointer to "struct dentry".
215  * @old_name: Symlink's content.
216  *
217  * Returns 0 on success, negative value otherwise.
218  */
219 static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
220                                const char *old_name)
221 {
222         struct path path = { parent->mnt, dentry };
223         return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
224 }
225
226 /**
227  * tomoyo_path_mknod - Target for security_path_mknod().
228  *
229  * @parent: Pointer to "struct path".
230  * @dentry: Pointer to "struct dentry".
231  * @mode:   DAC permission mode.
232  * @dev:    Device attributes.
233  *
234  * Returns 0 on success, negative value otherwise.
235  */
236 static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
237                              umode_t mode, unsigned int dev)
238 {
239         struct path path = { parent->mnt, dentry };
240         int type = TOMOYO_TYPE_CREATE;
241         const unsigned int perm = mode & S_IALLUGO;
242
243         switch (mode & S_IFMT) {
244         case S_IFCHR:
245                 type = TOMOYO_TYPE_MKCHAR;
246                 break;
247         case S_IFBLK:
248                 type = TOMOYO_TYPE_MKBLOCK;
249                 break;
250         default:
251                 goto no_dev;
252         }
253         return tomoyo_mkdev_perm(type, &path, perm, dev);
254  no_dev:
255         switch (mode & S_IFMT) {
256         case S_IFIFO:
257                 type = TOMOYO_TYPE_MKFIFO;
258                 break;
259         case S_IFSOCK:
260                 type = TOMOYO_TYPE_MKSOCK;
261                 break;
262         }
263         return tomoyo_path_number_perm(type, &path, perm);
264 }
265
266 /**
267  * tomoyo_path_link - Target for security_path_link().
268  *
269  * @old_dentry: Pointer to "struct dentry".
270  * @new_dir:    Pointer to "struct path".
271  * @new_dentry: Pointer to "struct dentry".
272  *
273  * Returns 0 on success, negative value otherwise.
274  */
275 static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
276                             struct dentry *new_dentry)
277 {
278         struct path path1 = { new_dir->mnt, old_dentry };
279         struct path path2 = { new_dir->mnt, new_dentry };
280         return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
281 }
282
283 /**
284  * tomoyo_path_rename - Target for security_path_rename().
285  *
286  * @old_parent: Pointer to "struct path".
287  * @old_dentry: Pointer to "struct dentry".
288  * @new_parent: Pointer to "struct path".
289  * @new_dentry: Pointer to "struct dentry".
290  *
291  * Returns 0 on success, negative value otherwise.
292  */
293 static int tomoyo_path_rename(struct path *old_parent,
294                               struct dentry *old_dentry,
295                               struct path *new_parent,
296                               struct dentry *new_dentry)
297 {
298         struct path path1 = { old_parent->mnt, old_dentry };
299         struct path path2 = { new_parent->mnt, new_dentry };
300         return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
301 }
302
303 /**
304  * tomoyo_file_fcntl - Target for security_file_fcntl().
305  *
306  * @file: Pointer to "struct file".
307  * @cmd:  Command for fcntl().
308  * @arg:  Argument for @cmd.
309  *
310  * Returns 0 on success, negative value otherwise.
311  */
312 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
313                              unsigned long arg)
314 {
315         if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
316                 return 0;
317         return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
318                                             O_WRONLY | (arg & O_APPEND));
319 }
320
321 /**
322  * tomoyo_file_open - Target for security_file_open().
323  *
324  * @f:    Pointer to "struct file".
325  * @cred: Pointer to "struct cred".
326  *
327  * Returns 0 on success, negative value otherwise.
328  */
329 static int tomoyo_file_open(struct file *f, const struct cred *cred)
330 {
331         int flags = f->f_flags;
332         /* Don't check read permission here if called from do_execve(). */
333         if (current->in_execve)
334                 return 0;
335         return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
336 }
337
338 /**
339  * tomoyo_file_ioctl - Target for security_file_ioctl().
340  *
341  * @file: Pointer to "struct file".
342  * @cmd:  Command for ioctl().
343  * @arg:  Argument for @cmd.
344  *
345  * Returns 0 on success, negative value otherwise.
346  */
347 static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
348                              unsigned long arg)
349 {
350         return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
351 }
352
353 /**
354  * tomoyo_path_chmod - Target for security_path_chmod().
355  *
356  * @path: Pointer to "struct path".
357  * @mode: DAC permission mode.
358  *
359  * Returns 0 on success, negative value otherwise.
360  */
361 static int tomoyo_path_chmod(struct path *path, umode_t mode)
362 {
363         return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
364                                        mode & S_IALLUGO);
365 }
366
367 /**
368  * tomoyo_path_chown - Target for security_path_chown().
369  *
370  * @path: Pointer to "struct path".
371  * @uid:  Owner ID.
372  * @gid:  Group ID.
373  *
374  * Returns 0 on success, negative value otherwise.
375  */
376 static int tomoyo_path_chown(struct path *path, kuid_t uid, kgid_t gid)
377 {
378         int error = 0;
379         if (uid_valid(uid))
380                 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
381                                                 from_kuid(&init_user_ns, uid));
382         if (!error && gid_valid(gid))
383                 error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
384                                                 from_kgid(&init_user_ns, gid));
385         return error;
386 }
387
388 /**
389  * tomoyo_path_chroot - Target for security_path_chroot().
390  *
391  * @path: Pointer to "struct path".
392  *
393  * Returns 0 on success, negative value otherwise.
394  */
395 static int tomoyo_path_chroot(struct path *path)
396 {
397         return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
398 }
399
400 /**
401  * tomoyo_sb_mount - Target for security_sb_mount().
402  *
403  * @dev_name: Name of device file. Maybe NULL.
404  * @path:     Pointer to "struct path".
405  * @type:     Name of filesystem type. Maybe NULL.
406  * @flags:    Mount options.
407  * @data:     Optional data. Maybe NULL.
408  *
409  * Returns 0 on success, negative value otherwise.
410  */
411 static int tomoyo_sb_mount(const char *dev_name, struct path *path,
412                            const char *type, unsigned long flags, void *data)
413 {
414         return tomoyo_mount_permission(dev_name, path, type, flags, data);
415 }
416
417 /**
418  * tomoyo_sb_umount - Target for security_sb_umount().
419  *
420  * @mnt:   Pointer to "struct vfsmount".
421  * @flags: Unmount options.
422  *
423  * Returns 0 on success, negative value otherwise.
424  */
425 static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
426 {
427         struct path path = { mnt, mnt->mnt_root };
428         return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
429 }
430
431 /**
432  * tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
433  *
434  * @old_path: Pointer to "struct path".
435  * @new_path: Pointer to "struct path".
436  *
437  * Returns 0 on success, negative value otherwise.
438  */
439 static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
440 {
441         return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
442 }
443
444 /**
445  * tomoyo_socket_listen - Check permission for listen().
446  *
447  * @sock:    Pointer to "struct socket".
448  * @backlog: Backlog parameter.
449  *
450  * Returns 0 on success, negative value otherwise.
451  */
452 static int tomoyo_socket_listen(struct socket *sock, int backlog)
453 {
454         return tomoyo_socket_listen_permission(sock);
455 }
456
457 /**
458  * tomoyo_socket_connect - Check permission for connect().
459  *
460  * @sock:     Pointer to "struct socket".
461  * @addr:     Pointer to "struct sockaddr".
462  * @addr_len: Size of @addr.
463  *
464  * Returns 0 on success, negative value otherwise.
465  */
466 static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
467                                  int addr_len)
468 {
469         return tomoyo_socket_connect_permission(sock, addr, addr_len);
470 }
471
472 /**
473  * tomoyo_socket_bind - Check permission for bind().
474  *
475  * @sock:     Pointer to "struct socket".
476  * @addr:     Pointer to "struct sockaddr".
477  * @addr_len: Size of @addr.
478  *
479  * Returns 0 on success, negative value otherwise.
480  */
481 static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
482                               int addr_len)
483 {
484         return tomoyo_socket_bind_permission(sock, addr, addr_len);
485 }
486
487 /**
488  * tomoyo_socket_sendmsg - Check permission for sendmsg().
489  *
490  * @sock: Pointer to "struct socket".
491  * @msg:  Pointer to "struct msghdr".
492  * @size: Size of message.
493  *
494  * Returns 0 on success, negative value otherwise.
495  */
496 static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
497                                  int size)
498 {
499         return tomoyo_socket_sendmsg_permission(sock, msg, size);
500 }
501
502 /*
503  * tomoyo_security_ops is a "struct security_operations" which is used for
504  * registering TOMOYO.
505  */
506 static struct security_operations tomoyo_security_ops = {
507         .name                = "tomoyo",
508         .cred_alloc_blank    = tomoyo_cred_alloc_blank,
509         .cred_prepare        = tomoyo_cred_prepare,
510         .cred_transfer       = tomoyo_cred_transfer,
511         .cred_free           = tomoyo_cred_free,
512         .bprm_set_creds      = tomoyo_bprm_set_creds,
513         .bprm_check_security = tomoyo_bprm_check_security,
514         .file_fcntl          = tomoyo_file_fcntl,
515         .file_open           = tomoyo_file_open,
516         .path_truncate       = tomoyo_path_truncate,
517         .path_unlink         = tomoyo_path_unlink,
518         .path_mkdir          = tomoyo_path_mkdir,
519         .path_rmdir          = tomoyo_path_rmdir,
520         .path_symlink        = tomoyo_path_symlink,
521         .path_mknod          = tomoyo_path_mknod,
522         .path_link           = tomoyo_path_link,
523         .path_rename         = tomoyo_path_rename,
524         .inode_getattr       = tomoyo_inode_getattr,
525         .file_ioctl          = tomoyo_file_ioctl,
526         .path_chmod          = tomoyo_path_chmod,
527         .path_chown          = tomoyo_path_chown,
528         .path_chroot         = tomoyo_path_chroot,
529         .sb_mount            = tomoyo_sb_mount,
530         .sb_umount           = tomoyo_sb_umount,
531         .sb_pivotroot        = tomoyo_sb_pivotroot,
532         .socket_bind         = tomoyo_socket_bind,
533         .socket_connect      = tomoyo_socket_connect,
534         .socket_listen       = tomoyo_socket_listen,
535         .socket_sendmsg      = tomoyo_socket_sendmsg,
536 };
537
538 /* Lock for GC. */
539 DEFINE_SRCU(tomoyo_ss);
540
541 /**
542  * tomoyo_init - Register TOMOYO Linux as a LSM module.
543  *
544  * Returns 0.
545  */
546 static int __init tomoyo_init(void)
547 {
548         struct cred *cred = (struct cred *) current_cred();
549
550         if (!security_module_enable(&tomoyo_security_ops))
551                 return 0;
552         /* register ourselves with the security framework */
553         if (register_security(&tomoyo_security_ops))
554                 panic("Failure registering TOMOYO Linux");
555         printk(KERN_INFO "TOMOYO Linux initialized\n");
556         cred->security = &tomoyo_kernel_domain;
557         tomoyo_mm_init();
558         return 0;
559 }
560
561 security_initcall(tomoyo_init);