blob: e7c642458ec9431b1639935880b6082f21492f6a [file] [log] [blame]
Casey Schauflere114e472008-02-04 22:29:50 -08001/*
2 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, version 2.
7 *
8 * Authors:
9 * Casey Schaufler <casey@schaufler-ca.com>
10 * Ahmed S. Darwish <darwish.07@gmail.com>
11 *
12 * Special thanks to the authors of selinuxfs.
13 *
14 * Karl MacMillan <kmacmillan@tresys.com>
15 * James Morris <jmorris@redhat.com>
16 *
17 */
18
19#include <linux/kernel.h>
20#include <linux/vmalloc.h>
21#include <linux/security.h>
22#include <linux/mutex.h>
23#include <net/netlabel.h>
24#include <net/cipso_ipv4.h>
25#include <linux/seq_file.h>
26#include <linux/ctype.h>
Casey Schaufler4bc87e62008-02-15 15:24:25 -080027#include <linux/audit.h>
Casey Schauflere114e472008-02-04 22:29:50 -080028#include "smack.h"
29
30/*
31 * smackfs pseudo filesystem.
32 */
33
34enum smk_inos {
35 SMK_ROOT_INO = 2,
36 SMK_LOAD = 3, /* load policy */
37 SMK_CIPSO = 4, /* load label -> CIPSO mapping */
38 SMK_DOI = 5, /* CIPSO DOI */
39 SMK_DIRECT = 6, /* CIPSO level indicating direct label */
40 SMK_AMBIENT = 7, /* internet ambient label */
41 SMK_NLTYPE = 8, /* label scheme to use by default */
Casey Schaufler15446232008-07-30 15:37:11 -070042 SMK_ONLYCAP = 9, /* the only "capable" label */
Casey Schauflere114e472008-02-04 22:29:50 -080043};
44
45/*
46 * List locks
47 */
48static DEFINE_MUTEX(smack_list_lock);
49static DEFINE_MUTEX(smack_cipso_lock);
Casey Schaufler4bc87e62008-02-15 15:24:25 -080050static DEFINE_MUTEX(smack_ambient_lock);
Casey Schauflere114e472008-02-04 22:29:50 -080051
52/*
53 * This is the "ambient" label for network traffic.
54 * If it isn't somehow marked, use this.
55 * It can be reset via smackfs/ambient
56 */
57char *smack_net_ambient = smack_known_floor.smk_known;
58
59/*
60 * This is the default packet marking scheme for network traffic.
61 * It can be reset via smackfs/nltype
62 */
63int smack_net_nltype = NETLBL_NLTYPE_CIPSOV4;
64
65/*
66 * This is the level in a CIPSO header that indicates a
67 * smack label is contained directly in the category set.
68 * It can be reset via smackfs/direct
69 */
70int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
71
Casey Schaufler15446232008-07-30 15:37:11 -070072/*
73 * Unless a process is running with this label even
74 * having CAP_MAC_OVERRIDE isn't enough to grant
75 * privilege to violate MAC policy. If no label is
76 * designated (the NULL case) capabilities apply to
77 * everyone. It is expected that the hat (^) label
78 * will be used if any label is used.
79 */
80char *smack_onlycap;
81
Casey Schauflere114e472008-02-04 22:29:50 -080082static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
83struct smk_list_entry *smack_list;
84
85#define SEQ_READ_FINISHED 1
86
87/*
Casey Schauflere114e472008-02-04 22:29:50 -080088 * Values for parsing cipso rules
89 * SMK_DIGITLEN: Length of a digit field in a rule.
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -070090 * SMK_CIPSOMIN: Minimum possible cipso rule length.
91 * SMK_CIPSOMAX: Maximum possible cipso rule length.
Casey Schauflere114e472008-02-04 22:29:50 -080092 */
93#define SMK_DIGITLEN 4
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -070094#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN)
95#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN)
96
97/*
98 * Values for parsing MAC rules
99 * SMK_ACCESS: Maximum possible combination of access permissions
100 * SMK_ACCESSLEN: Maximum length for a rule access field
101 * SMK_LOADLEN: Smack rule length
102 */
103#define SMK_ACCESS "rwxa"
104#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1)
105#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
106
Casey Schauflere114e472008-02-04 22:29:50 -0800107
108/*
109 * Seq_file read operations for /smack/load
110 */
111
112static void *load_seq_start(struct seq_file *s, loff_t *pos)
113{
114 if (*pos == SEQ_READ_FINISHED)
115 return NULL;
116
117 return smack_list;
118}
119
120static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos)
121{
122 struct smk_list_entry *skp = ((struct smk_list_entry *) v)->smk_next;
123
124 if (skp == NULL)
125 *pos = SEQ_READ_FINISHED;
126
127 return skp;
128}
129
130static int load_seq_show(struct seq_file *s, void *v)
131{
132 struct smk_list_entry *slp = (struct smk_list_entry *) v;
133 struct smack_rule *srp = &slp->smk_rule;
134
135 seq_printf(s, "%s %s", (char *)srp->smk_subject,
136 (char *)srp->smk_object);
137
138 seq_putc(s, ' ');
139
140 if (srp->smk_access & MAY_READ)
141 seq_putc(s, 'r');
142 if (srp->smk_access & MAY_WRITE)
143 seq_putc(s, 'w');
144 if (srp->smk_access & MAY_EXEC)
145 seq_putc(s, 'x');
146 if (srp->smk_access & MAY_APPEND)
147 seq_putc(s, 'a');
148 if (srp->smk_access == 0)
149 seq_putc(s, '-');
150
151 seq_putc(s, '\n');
152
153 return 0;
154}
155
156static void load_seq_stop(struct seq_file *s, void *v)
157{
158 /* No-op */
159}
160
161static struct seq_operations load_seq_ops = {
162 .start = load_seq_start,
163 .next = load_seq_next,
164 .show = load_seq_show,
165 .stop = load_seq_stop,
166};
167
168/**
169 * smk_open_load - open() for /smack/load
170 * @inode: inode structure representing file
171 * @file: "load" file pointer
172 *
173 * For reading, use load_seq_* seq_file reading operations.
174 */
175static int smk_open_load(struct inode *inode, struct file *file)
176{
Ahmed S. Darwishcb622bb2008-03-24 12:29:49 -0700177 return seq_open(file, &load_seq_ops);
Casey Schauflere114e472008-02-04 22:29:50 -0800178}
179
180/**
181 * smk_set_access - add a rule to the rule list
182 * @srp: the new rule to add
183 *
184 * Looks through the current subject/object/access list for
185 * the subject/object pair and replaces the access that was
186 * there. If the pair isn't found add it with the specified
187 * access.
188 */
189static void smk_set_access(struct smack_rule *srp)
190{
191 struct smk_list_entry *sp;
192 struct smk_list_entry *newp;
193
194 mutex_lock(&smack_list_lock);
195
196 for (sp = smack_list; sp != NULL; sp = sp->smk_next)
197 if (sp->smk_rule.smk_subject == srp->smk_subject &&
198 sp->smk_rule.smk_object == srp->smk_object) {
199 sp->smk_rule.smk_access = srp->smk_access;
200 break;
201 }
202
203 if (sp == NULL) {
204 newp = kzalloc(sizeof(struct smk_list_entry), GFP_KERNEL);
205 newp->smk_rule = *srp;
206 newp->smk_next = smack_list;
207 smack_list = newp;
208 }
209
210 mutex_unlock(&smack_list_lock);
211
212 return;
213}
214
215/**
216 * smk_write_load - write() for /smack/load
217 * @filp: file pointer, not actually used
218 * @buf: where to get the data from
219 * @count: bytes sent
220 * @ppos: where to start - must be 0
221 *
222 * Get one smack access rule from above.
223 * The format is exactly:
224 * char subject[SMK_LABELLEN]
225 * char object[SMK_LABELLEN]
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -0700226 * char access[SMK_ACCESSLEN]
Casey Schauflere114e472008-02-04 22:29:50 -0800227 *
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -0700228 * writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes.
Casey Schauflere114e472008-02-04 22:29:50 -0800229 */
Casey Schauflere114e472008-02-04 22:29:50 -0800230static ssize_t smk_write_load(struct file *file, const char __user *buf,
231 size_t count, loff_t *ppos)
232{
233 struct smack_rule rule;
234 char *data;
235 int rc = -EINVAL;
236
237 /*
238 * Must have privilege.
239 * No partial writes.
240 * Enough data must be present.
241 */
242 if (!capable(CAP_MAC_ADMIN))
243 return -EPERM;
244 if (*ppos != 0)
245 return -EINVAL;
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -0700246 if (count != SMK_LOADLEN)
Casey Schauflere114e472008-02-04 22:29:50 -0800247 return -EINVAL;
248
249 data = kzalloc(count, GFP_KERNEL);
250 if (data == NULL)
251 return -ENOMEM;
252
253 if (copy_from_user(data, buf, count) != 0) {
254 rc = -EFAULT;
255 goto out;
256 }
257
258 rule.smk_subject = smk_import(data, 0);
259 if (rule.smk_subject == NULL)
260 goto out;
261
262 rule.smk_object = smk_import(data + SMK_LABELLEN, 0);
263 if (rule.smk_object == NULL)
264 goto out;
265
266 rule.smk_access = 0;
267
268 switch (data[SMK_LABELLEN + SMK_LABELLEN]) {
269 case '-':
270 break;
271 case 'r':
272 case 'R':
273 rule.smk_access |= MAY_READ;
274 break;
275 default:
276 goto out;
277 }
278
279 switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) {
280 case '-':
281 break;
282 case 'w':
283 case 'W':
284 rule.smk_access |= MAY_WRITE;
285 break;
286 default:
287 goto out;
288 }
289
290 switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) {
291 case '-':
292 break;
293 case 'x':
294 case 'X':
295 rule.smk_access |= MAY_EXEC;
296 break;
297 default:
298 goto out;
299 }
300
301 switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) {
302 case '-':
303 break;
304 case 'a':
305 case 'A':
306 rule.smk_access |= MAY_READ;
307 break;
308 default:
309 goto out;
310 }
311
312 smk_set_access(&rule);
313 rc = count;
314
315out:
316 kfree(data);
317 return rc;
318}
319
320static const struct file_operations smk_load_ops = {
321 .open = smk_open_load,
322 .read = seq_read,
323 .llseek = seq_lseek,
324 .write = smk_write_load,
Ahmed S. Darwishcb622bb2008-03-24 12:29:49 -0700325 .release = seq_release,
Casey Schauflere114e472008-02-04 22:29:50 -0800326};
327
328/**
329 * smk_cipso_doi - initialize the CIPSO domain
330 */
Casey Schaufler30aa4fa2008-04-28 02:13:43 -0700331static void smk_cipso_doi(void)
Casey Schauflere114e472008-02-04 22:29:50 -0800332{
333 int rc;
334 struct cipso_v4_doi *doip;
335 struct netlbl_audit audit_info;
336
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800337 audit_info.loginuid = audit_get_loginuid(current);
Eric Paris25323862008-04-18 10:09:25 -0400338 audit_info.sessionid = audit_get_sessionid(current);
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800339 audit_info.secid = smack_to_secid(current->security);
340
Casey Schauflere114e472008-02-04 22:29:50 -0800341 rc = netlbl_cfg_map_del(NULL, &audit_info);
342 if (rc != 0)
343 printk(KERN_WARNING "%s:%d remove rc = %d\n",
344 __func__, __LINE__, rc);
345
346 doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL);
347 if (doip == NULL)
348 panic("smack: Failed to initialize cipso DOI.\n");
349 doip->map.std = NULL;
350 doip->doi = smk_cipso_doi_value;
351 doip->type = CIPSO_V4_MAP_PASS;
352 doip->tags[0] = CIPSO_V4_TAG_RBITMAP;
353 for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++)
354 doip->tags[rc] = CIPSO_V4_TAG_INVALID;
355
356 rc = netlbl_cfg_cipsov4_add_map(doip, NULL, &audit_info);
357 if (rc != 0)
358 printk(KERN_WARNING "%s:%d add rc = %d\n",
359 __func__, __LINE__, rc);
360}
361
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800362/**
363 * smk_unlbl_ambient - initialize the unlabeled domain
364 */
Casey Schaufler30aa4fa2008-04-28 02:13:43 -0700365static void smk_unlbl_ambient(char *oldambient)
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800366{
367 int rc;
368 struct netlbl_audit audit_info;
369
370 audit_info.loginuid = audit_get_loginuid(current);
Eric Paris25323862008-04-18 10:09:25 -0400371 audit_info.sessionid = audit_get_sessionid(current);
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800372 audit_info.secid = smack_to_secid(current->security);
373
374 if (oldambient != NULL) {
375 rc = netlbl_cfg_map_del(oldambient, &audit_info);
376 if (rc != 0)
377 printk(KERN_WARNING "%s:%d remove rc = %d\n",
378 __func__, __LINE__, rc);
379 }
380
381 rc = netlbl_cfg_unlbl_add_map(smack_net_ambient, &audit_info);
382 if (rc != 0)
383 printk(KERN_WARNING "%s:%d add rc = %d\n",
384 __func__, __LINE__, rc);
385}
386
Casey Schauflere114e472008-02-04 22:29:50 -0800387/*
388 * Seq_file read operations for /smack/cipso
389 */
390
391static void *cipso_seq_start(struct seq_file *s, loff_t *pos)
392{
393 if (*pos == SEQ_READ_FINISHED)
394 return NULL;
395
396 return smack_known;
397}
398
399static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos)
400{
401 struct smack_known *skp = ((struct smack_known *) v)->smk_next;
402
403 /*
404 * Omit labels with no associated cipso value
405 */
406 while (skp != NULL && !skp->smk_cipso)
407 skp = skp->smk_next;
408
409 if (skp == NULL)
410 *pos = SEQ_READ_FINISHED;
411
412 return skp;
413}
414
415/*
416 * Print cipso labels in format:
417 * label level[/cat[,cat]]
418 */
419static int cipso_seq_show(struct seq_file *s, void *v)
420{
421 struct smack_known *skp = (struct smack_known *) v;
422 struct smack_cipso *scp = skp->smk_cipso;
423 char *cbp;
424 char sep = '/';
425 int cat = 1;
426 int i;
427 unsigned char m;
428
429 if (scp == NULL)
430 return 0;
431
432 seq_printf(s, "%s %3d", (char *)&skp->smk_known, scp->smk_level);
433
434 cbp = scp->smk_catset;
435 for (i = 0; i < SMK_LABELLEN; i++)
436 for (m = 0x80; m != 0; m >>= 1) {
437 if (m & cbp[i]) {
438 seq_printf(s, "%c%d", sep, cat);
439 sep = ',';
440 }
441 cat++;
442 }
443
444 seq_putc(s, '\n');
445
446 return 0;
447}
448
449static void cipso_seq_stop(struct seq_file *s, void *v)
450{
451 /* No-op */
452}
453
454static struct seq_operations cipso_seq_ops = {
455 .start = cipso_seq_start,
456 .stop = cipso_seq_stop,
457 .next = cipso_seq_next,
458 .show = cipso_seq_show,
459};
460
461/**
462 * smk_open_cipso - open() for /smack/cipso
463 * @inode: inode structure representing file
464 * @file: "cipso" file pointer
465 *
466 * Connect our cipso_seq_* operations with /smack/cipso
467 * file_operations
468 */
469static int smk_open_cipso(struct inode *inode, struct file *file)
470{
471 return seq_open(file, &cipso_seq_ops);
472}
473
474/**
475 * smk_write_cipso - write() for /smack/cipso
476 * @filp: file pointer, not actually used
477 * @buf: where to get the data from
478 * @count: bytes sent
479 * @ppos: where to start
480 *
481 * Accepts only one cipso rule per write call.
482 * Returns number of bytes written or error code, as appropriate
483 */
484static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
485 size_t count, loff_t *ppos)
486{
487 struct smack_known *skp;
488 struct smack_cipso *scp = NULL;
489 char mapcatset[SMK_LABELLEN];
490 int maplevel;
491 int cat;
492 int catlen;
493 ssize_t rc = -EINVAL;
494 char *data = NULL;
495 char *rule;
496 int ret;
497 int i;
498
499 /*
500 * Must have privilege.
501 * No partial writes.
502 * Enough data must be present.
503 */
504 if (!capable(CAP_MAC_ADMIN))
505 return -EPERM;
506 if (*ppos != 0)
507 return -EINVAL;
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -0700508 if (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX)
Casey Schauflere114e472008-02-04 22:29:50 -0800509 return -EINVAL;
510
511 data = kzalloc(count + 1, GFP_KERNEL);
512 if (data == NULL)
513 return -ENOMEM;
514
515 if (copy_from_user(data, buf, count) != 0) {
516 rc = -EFAULT;
517 goto unlockedout;
518 }
519
520 data[count] = '\0';
521 rule = data;
522 /*
523 * Only allow one writer at a time. Writes should be
524 * quite rare and small in any case.
525 */
526 mutex_lock(&smack_cipso_lock);
527
528 skp = smk_import_entry(rule, 0);
529 if (skp == NULL)
530 goto out;
531
532 rule += SMK_LABELLEN;;
533 ret = sscanf(rule, "%d", &maplevel);
534 if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL)
535 goto out;
536
537 rule += SMK_DIGITLEN;
538 ret = sscanf(rule, "%d", &catlen);
539 if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM)
540 goto out;
541
Ahmed S. Darwishb500ce82008-03-13 12:32:34 -0700542 if (count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
Casey Schauflere114e472008-02-04 22:29:50 -0800543 goto out;
544
545 memset(mapcatset, 0, sizeof(mapcatset));
546
547 for (i = 0; i < catlen; i++) {
548 rule += SMK_DIGITLEN;
549 ret = sscanf(rule, "%d", &cat);
550 if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL)
551 goto out;
552
553 smack_catset_bit(cat, mapcatset);
554 }
555
556 if (skp->smk_cipso == NULL) {
557 scp = kzalloc(sizeof(struct smack_cipso), GFP_KERNEL);
558 if (scp == NULL) {
559 rc = -ENOMEM;
560 goto out;
561 }
562 }
563
564 spin_lock_bh(&skp->smk_cipsolock);
565
566 if (scp == NULL)
567 scp = skp->smk_cipso;
568 else
569 skp->smk_cipso = scp;
570
571 scp->smk_level = maplevel;
572 memcpy(scp->smk_catset, mapcatset, sizeof(mapcatset));
573
574 spin_unlock_bh(&skp->smk_cipsolock);
575
576 rc = count;
577out:
578 mutex_unlock(&smack_cipso_lock);
579unlockedout:
580 kfree(data);
581 return rc;
582}
583
584static const struct file_operations smk_cipso_ops = {
585 .open = smk_open_cipso,
586 .read = seq_read,
587 .llseek = seq_lseek,
588 .write = smk_write_cipso,
589 .release = seq_release,
590};
591
592/**
593 * smk_read_doi - read() for /smack/doi
594 * @filp: file pointer, not actually used
595 * @buf: where to put the result
596 * @count: maximum to send along
597 * @ppos: where to start
598 *
599 * Returns number of bytes read or error code, as appropriate
600 */
601static ssize_t smk_read_doi(struct file *filp, char __user *buf,
602 size_t count, loff_t *ppos)
603{
604 char temp[80];
605 ssize_t rc;
606
607 if (*ppos != 0)
608 return 0;
609
610 sprintf(temp, "%d", smk_cipso_doi_value);
611 rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
612
613 return rc;
614}
615
616/**
617 * smk_write_doi - write() for /smack/doi
618 * @filp: file pointer, not actually used
619 * @buf: where to get the data from
620 * @count: bytes sent
621 * @ppos: where to start
622 *
623 * Returns number of bytes written or error code, as appropriate
624 */
625static ssize_t smk_write_doi(struct file *file, const char __user *buf,
626 size_t count, loff_t *ppos)
627{
628 char temp[80];
629 int i;
630
631 if (!capable(CAP_MAC_ADMIN))
632 return -EPERM;
633
634 if (count >= sizeof(temp) || count == 0)
635 return -EINVAL;
636
637 if (copy_from_user(temp, buf, count) != 0)
638 return -EFAULT;
639
640 temp[count] = '\0';
641
642 if (sscanf(temp, "%d", &i) != 1)
643 return -EINVAL;
644
645 smk_cipso_doi_value = i;
646
647 smk_cipso_doi();
648
649 return count;
650}
651
652static const struct file_operations smk_doi_ops = {
653 .read = smk_read_doi,
654 .write = smk_write_doi,
655};
656
657/**
658 * smk_read_direct - read() for /smack/direct
659 * @filp: file pointer, not actually used
660 * @buf: where to put the result
661 * @count: maximum to send along
662 * @ppos: where to start
663 *
664 * Returns number of bytes read or error code, as appropriate
665 */
666static ssize_t smk_read_direct(struct file *filp, char __user *buf,
667 size_t count, loff_t *ppos)
668{
669 char temp[80];
670 ssize_t rc;
671
672 if (*ppos != 0)
673 return 0;
674
675 sprintf(temp, "%d", smack_cipso_direct);
676 rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
677
678 return rc;
679}
680
681/**
682 * smk_write_direct - write() for /smack/direct
683 * @filp: file pointer, not actually used
684 * @buf: where to get the data from
685 * @count: bytes sent
686 * @ppos: where to start
687 *
688 * Returns number of bytes written or error code, as appropriate
689 */
690static ssize_t smk_write_direct(struct file *file, const char __user *buf,
691 size_t count, loff_t *ppos)
692{
693 char temp[80];
694 int i;
695
696 if (!capable(CAP_MAC_ADMIN))
697 return -EPERM;
698
699 if (count >= sizeof(temp) || count == 0)
700 return -EINVAL;
701
702 if (copy_from_user(temp, buf, count) != 0)
703 return -EFAULT;
704
705 temp[count] = '\0';
706
707 if (sscanf(temp, "%d", &i) != 1)
708 return -EINVAL;
709
710 smack_cipso_direct = i;
711
712 return count;
713}
714
715static const struct file_operations smk_direct_ops = {
716 .read = smk_read_direct,
717 .write = smk_write_direct,
718};
719
720/**
721 * smk_read_ambient - read() for /smack/ambient
722 * @filp: file pointer, not actually used
723 * @buf: where to put the result
724 * @cn: maximum to send along
725 * @ppos: where to start
726 *
727 * Returns number of bytes read or error code, as appropriate
728 */
729static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
730 size_t cn, loff_t *ppos)
731{
732 ssize_t rc;
Casey Schauflere114e472008-02-04 22:29:50 -0800733 int asize;
734
735 if (*ppos != 0)
736 return 0;
737 /*
738 * Being careful to avoid a problem in the case where
739 * smack_net_ambient gets changed in midstream.
Casey Schauflere114e472008-02-04 22:29:50 -0800740 */
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800741 mutex_lock(&smack_ambient_lock);
Casey Schauflere114e472008-02-04 22:29:50 -0800742
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800743 asize = strlen(smack_net_ambient) + 1;
Casey Schauflere114e472008-02-04 22:29:50 -0800744
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800745 if (cn >= asize)
746 rc = simple_read_from_buffer(buf, cn, ppos,
747 smack_net_ambient, asize);
748 else
749 rc = -EINVAL;
750
751 mutex_unlock(&smack_ambient_lock);
Casey Schauflere114e472008-02-04 22:29:50 -0800752
753 return rc;
754}
755
756/**
757 * smk_write_ambient - write() for /smack/ambient
758 * @filp: file pointer, not actually used
759 * @buf: where to get the data from
760 * @count: bytes sent
761 * @ppos: where to start
762 *
763 * Returns number of bytes written or error code, as appropriate
764 */
765static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
766 size_t count, loff_t *ppos)
767{
768 char in[SMK_LABELLEN];
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800769 char *oldambient;
Casey Schauflere114e472008-02-04 22:29:50 -0800770 char *smack;
771
772 if (!capable(CAP_MAC_ADMIN))
773 return -EPERM;
774
775 if (count >= SMK_LABELLEN)
776 return -EINVAL;
777
778 if (copy_from_user(in, buf, count) != 0)
779 return -EFAULT;
780
781 smack = smk_import(in, count);
782 if (smack == NULL)
783 return -EINVAL;
784
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800785 mutex_lock(&smack_ambient_lock);
786
787 oldambient = smack_net_ambient;
Casey Schauflere114e472008-02-04 22:29:50 -0800788 smack_net_ambient = smack;
Casey Schaufler4bc87e62008-02-15 15:24:25 -0800789 smk_unlbl_ambient(oldambient);
790
791 mutex_unlock(&smack_ambient_lock);
Casey Schauflere114e472008-02-04 22:29:50 -0800792
793 return count;
794}
795
796static const struct file_operations smk_ambient_ops = {
797 .read = smk_read_ambient,
798 .write = smk_write_ambient,
799};
800
Casey Schaufler15446232008-07-30 15:37:11 -0700801/**
802 * smk_read_onlycap - read() for /smack/onlycap
803 * @filp: file pointer, not actually used
804 * @buf: where to put the result
805 * @cn: maximum to send along
806 * @ppos: where to start
807 *
808 * Returns number of bytes read or error code, as appropriate
809 */
810static ssize_t smk_read_onlycap(struct file *filp, char __user *buf,
811 size_t cn, loff_t *ppos)
812{
813 char *smack = "";
814 ssize_t rc = -EINVAL;
815 int asize;
816
817 if (*ppos != 0)
818 return 0;
819
820 if (smack_onlycap != NULL)
821 smack = smack_onlycap;
822
823 asize = strlen(smack) + 1;
824
825 if (cn >= asize)
826 rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
827
828 return rc;
829}
830
831/**
832 * smk_write_onlycap - write() for /smack/onlycap
833 * @filp: file pointer, not actually used
834 * @buf: where to get the data from
835 * @count: bytes sent
836 * @ppos: where to start
837 *
838 * Returns number of bytes written or error code, as appropriate
839 */
840static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
841 size_t count, loff_t *ppos)
842{
843 char in[SMK_LABELLEN];
844 char *sp = current->security;
845
846 if (!capable(CAP_MAC_ADMIN))
847 return -EPERM;
848
849 /*
850 * This can be done using smk_access() but is done
851 * explicitly for clarity. The smk_access() implementation
852 * would use smk_access(smack_onlycap, MAY_WRITE)
853 */
854 if (smack_onlycap != NULL && smack_onlycap != sp)
855 return -EPERM;
856
857 if (count >= SMK_LABELLEN)
858 return -EINVAL;
859
860 if (copy_from_user(in, buf, count) != 0)
861 return -EFAULT;
862
863 /*
864 * Should the null string be passed in unset the onlycap value.
865 * This seems like something to be careful with as usually
866 * smk_import only expects to return NULL for errors. It
867 * is usually the case that a nullstring or "\n" would be
868 * bad to pass to smk_import but in fact this is useful here.
869 */
870 smack_onlycap = smk_import(in, count);
871
872 return count;
873}
874
875static const struct file_operations smk_onlycap_ops = {
876 .read = smk_read_onlycap,
877 .write = smk_write_onlycap,
878};
879
Casey Schauflere114e472008-02-04 22:29:50 -0800880struct option_names {
881 int o_number;
882 char *o_name;
883 char *o_alias;
884};
885
886static struct option_names netlbl_choices[] = {
887 { NETLBL_NLTYPE_RIPSO,
888 NETLBL_NLTYPE_RIPSO_NAME, "ripso" },
889 { NETLBL_NLTYPE_CIPSOV4,
890 NETLBL_NLTYPE_CIPSOV4_NAME, "cipsov4" },
891 { NETLBL_NLTYPE_CIPSOV4,
892 NETLBL_NLTYPE_CIPSOV4_NAME, "cipso" },
893 { NETLBL_NLTYPE_CIPSOV6,
894 NETLBL_NLTYPE_CIPSOV6_NAME, "cipsov6" },
895 { NETLBL_NLTYPE_UNLABELED,
896 NETLBL_NLTYPE_UNLABELED_NAME, "unlabeled" },
897};
898
899/**
900 * smk_read_nltype - read() for /smack/nltype
901 * @filp: file pointer, not actually used
902 * @buf: where to put the result
903 * @count: maximum to send along
904 * @ppos: where to start
905 *
906 * Returns number of bytes read or error code, as appropriate
907 */
908static ssize_t smk_read_nltype(struct file *filp, char __user *buf,
909 size_t count, loff_t *ppos)
910{
911 char bound[40];
912 ssize_t rc;
913 int i;
914
915 if (count < SMK_LABELLEN)
916 return -EINVAL;
917
918 if (*ppos != 0)
919 return 0;
920
921 sprintf(bound, "unknown");
922
923 for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
924 if (smack_net_nltype == netlbl_choices[i].o_number) {
925 sprintf(bound, "%s", netlbl_choices[i].o_name);
926 break;
927 }
928
929 rc = simple_read_from_buffer(buf, count, ppos, bound, strlen(bound));
930
931 return rc;
932}
933
934/**
935 * smk_write_nltype - write() for /smack/nltype
936 * @filp: file pointer, not actually used
937 * @buf: where to get the data from
938 * @count: bytes sent
939 * @ppos: where to start
940 *
941 * Returns number of bytes written or error code, as appropriate
942 */
943static ssize_t smk_write_nltype(struct file *file, const char __user *buf,
944 size_t count, loff_t *ppos)
945{
946 char bound[40];
947 char *cp;
948 int i;
949
950 if (!capable(CAP_MAC_ADMIN))
951 return -EPERM;
952
953 if (count >= 40)
954 return -EINVAL;
955
956 if (copy_from_user(bound, buf, count) != 0)
957 return -EFAULT;
958
959 bound[count] = '\0';
960 cp = strchr(bound, ' ');
961 if (cp != NULL)
962 *cp = '\0';
963 cp = strchr(bound, '\n');
964 if (cp != NULL)
965 *cp = '\0';
966
967 for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
968 if (strcmp(bound, netlbl_choices[i].o_name) == 0 ||
969 strcmp(bound, netlbl_choices[i].o_alias) == 0) {
970 smack_net_nltype = netlbl_choices[i].o_number;
971 return count;
972 }
973 /*
974 * Not a valid choice.
975 */
976 return -EINVAL;
977}
978
979static const struct file_operations smk_nltype_ops = {
980 .read = smk_read_nltype,
981 .write = smk_write_nltype,
982};
983
984/**
985 * smk_fill_super - fill the /smackfs superblock
986 * @sb: the empty superblock
987 * @data: unused
988 * @silent: unused
989 *
990 * Fill in the well known entries for /smack
991 *
992 * Returns 0 on success, an error code on failure
993 */
994static int smk_fill_super(struct super_block *sb, void *data, int silent)
995{
996 int rc;
997 struct inode *root_inode;
998
999 static struct tree_descr smack_files[] = {
1000 [SMK_LOAD] =
1001 {"load", &smk_load_ops, S_IRUGO|S_IWUSR},
1002 [SMK_CIPSO] =
1003 {"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR},
1004 [SMK_DOI] =
1005 {"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
1006 [SMK_DIRECT] =
1007 {"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
1008 [SMK_AMBIENT] =
1009 {"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
1010 [SMK_NLTYPE] =
1011 {"nltype", &smk_nltype_ops, S_IRUGO|S_IWUSR},
Casey Schaufler15446232008-07-30 15:37:11 -07001012 [SMK_ONLYCAP] =
1013 {"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
Casey Schauflere114e472008-02-04 22:29:50 -08001014 /* last one */ {""}
1015 };
1016
1017 rc = simple_fill_super(sb, SMACK_MAGIC, smack_files);
1018 if (rc != 0) {
1019 printk(KERN_ERR "%s failed %d while creating inodes\n",
1020 __func__, rc);
1021 return rc;
1022 }
1023
1024 root_inode = sb->s_root->d_inode;
1025 root_inode->i_security = new_inode_smack(smack_known_floor.smk_known);
1026
1027 return 0;
1028}
1029
1030/**
1031 * smk_get_sb - get the smackfs superblock
1032 * @fs_type: passed along without comment
1033 * @flags: passed along without comment
1034 * @dev_name: passed along without comment
1035 * @data: passed along without comment
1036 * @mnt: passed along without comment
1037 *
1038 * Just passes everything along.
1039 *
1040 * Returns what the lower level code does.
1041 */
1042static int smk_get_sb(struct file_system_type *fs_type,
1043 int flags, const char *dev_name, void *data,
1044 struct vfsmount *mnt)
1045{
1046 return get_sb_single(fs_type, flags, data, smk_fill_super, mnt);
1047}
1048
1049static struct file_system_type smk_fs_type = {
1050 .name = "smackfs",
1051 .get_sb = smk_get_sb,
1052 .kill_sb = kill_litter_super,
1053};
1054
1055static struct vfsmount *smackfs_mount;
1056
1057/**
1058 * init_smk_fs - get the smackfs superblock
1059 *
1060 * register the smackfs
1061 *
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +02001062 * Do not register smackfs if Smack wasn't enabled
1063 * on boot. We can not put this method normally under the
1064 * smack_init() code path since the security subsystem get
1065 * initialized before the vfs caches.
1066 *
1067 * Returns true if we were not chosen on boot or if
1068 * we were chosen and filesystem registration succeeded.
Casey Schauflere114e472008-02-04 22:29:50 -08001069 */
1070static int __init init_smk_fs(void)
1071{
1072 int err;
1073
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +02001074 if (!security_module_enable(&smack_ops))
1075 return 0;
1076
Casey Schauflere114e472008-02-04 22:29:50 -08001077 err = register_filesystem(&smk_fs_type);
1078 if (!err) {
1079 smackfs_mount = kern_mount(&smk_fs_type);
1080 if (IS_ERR(smackfs_mount)) {
1081 printk(KERN_ERR "smackfs: could not mount!\n");
1082 err = PTR_ERR(smackfs_mount);
1083 smackfs_mount = NULL;
1084 }
1085 }
1086
Casey Schauflere114e472008-02-04 22:29:50 -08001087 smk_cipso_doi();
Casey Schaufler4bc87e62008-02-15 15:24:25 -08001088 smk_unlbl_ambient(NULL);
Casey Schauflere114e472008-02-04 22:29:50 -08001089
1090 return err;
1091}
1092
1093__initcall(init_smk_fs);