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1/*
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 * Author:
9 * Casey Schaufler <casey@schaufler-ca.com>
10 *
11 */
12
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/fs.h>
16#include <linux/sched.h>
17#include "smack.h"
18
19struct smack_known smack_known_huh = {
20 .smk_known = "?",
21 .smk_secid = 2,
22 .smk_cipso = NULL,
23};
24
25struct smack_known smack_known_hat = {
26 .smk_known = "^",
27 .smk_secid = 3,
28 .smk_cipso = NULL,
29};
30
31struct smack_known smack_known_star = {
32 .smk_known = "*",
33 .smk_secid = 4,
34 .smk_cipso = NULL,
35};
36
37struct smack_known smack_known_floor = {
38 .smk_known = "_",
39 .smk_secid = 5,
40 .smk_cipso = NULL,
41};
42
43struct smack_known smack_known_invalid = {
44 .smk_known = "",
45 .smk_secid = 6,
46 .smk_cipso = NULL,
47};
48
49struct smack_known smack_known_web = {
50 .smk_known = "@",
51 .smk_secid = 7,
52 .smk_cipso = NULL,
53};
54
55LIST_HEAD(smack_known_list);
56
57/*
58 * The initial value needs to be bigger than any of the
59 * known values above.
60 */
61static u32 smack_next_secid = 10;
62
63/*
64 * what events do we log
65 * can be overwritten at run-time by /smack/logging
66 */
67int log_policy = SMACK_AUDIT_DENIED;
68
69/**
70 * smk_access_entry - look up matching access rule
71 * @subject_label: a pointer to the subject's Smack label
72 * @object_label: a pointer to the object's Smack label
73 * @rule_list: the list of rules to search
74 *
75 * This function looks up the subject/object pair in the
76 * access rule list and returns the access mode. If no
77 * entry is found returns -ENOENT.
78 *
79 * NOTE:
80 * Even though Smack labels are usually shared on smack_list
81 * labels that come in off the network can't be imported
82 * and added to the list for locking reasons.
83 *
84 * Therefore, it is necessary to check the contents of the labels,
85 * not just the pointer values. Of course, in most cases the labels
86 * will be on the list, so checking the pointers may be a worthwhile
87 * optimization.
88 */
89int smk_access_entry(char *subject_label, char *object_label,
90 struct list_head *rule_list)
91{
92 int may = -ENOENT;
93 struct smack_rule *srp;
94
95 list_for_each_entry_rcu(srp, rule_list, list) {
96 if (srp->smk_subject == subject_label ||
97 strcmp(srp->smk_subject, subject_label) == 0) {
98 if (srp->smk_object == object_label ||
99 strcmp(srp->smk_object, object_label) == 0) {
100 may = srp->smk_access;
101 break;
102 }
103 }
104 }
105
106 return may;
107}
108
109/**
110 * smk_access - determine if a subject has a specific access to an object
111 * @subject_label: a pointer to the subject's Smack label
112 * @object_label: a pointer to the object's Smack label
113 * @request: the access requested, in "MAY" format
114 * @a : a pointer to the audit data
115 *
116 * This function looks up the subject/object pair in the
117 * access rule list and returns 0 if the access is permitted,
118 * non zero otherwise.
119 *
120 * Even though Smack labels are usually shared on smack_list
121 * labels that come in off the network can't be imported
122 * and added to the list for locking reasons.
123 *
124 * Therefore, it is necessary to check the contents of the labels,
125 * not just the pointer values. Of course, in most cases the labels
126 * will be on the list, so checking the pointers may be a worthwhile
127 * optimization.
128 */
129int smk_access(char *subject_label, char *object_label, int request,
130 struct smk_audit_info *a)
131{
132 int may = MAY_NOT;
133 int rc = 0;
134
135 /*
136 * Hardcoded comparisons.
137 *
138 * A star subject can't access any object.
139 */
140 if (subject_label == smack_known_star.smk_known ||
141 strcmp(subject_label, smack_known_star.smk_known) == 0) {
142 rc = -EACCES;
143 goto out_audit;
144 }
145 /*
146 * An internet object can be accessed by any subject.
147 * Tasks cannot be assigned the internet label.
148 * An internet subject can access any object.
149 */
150 if (object_label == smack_known_web.smk_known ||
151 subject_label == smack_known_web.smk_known ||
152 strcmp(object_label, smack_known_web.smk_known) == 0 ||
153 strcmp(subject_label, smack_known_web.smk_known) == 0)
154 goto out_audit;
155 /*
156 * A star object can be accessed by any subject.
157 */
158 if (object_label == smack_known_star.smk_known ||
159 strcmp(object_label, smack_known_star.smk_known) == 0)
160 goto out_audit;
161 /*
162 * An object can be accessed in any way by a subject
163 * with the same label.
164 */
165 if (subject_label == object_label ||
166 strcmp(subject_label, object_label) == 0)
167 goto out_audit;
168 /*
169 * A hat subject can read any object.
170 * A floor object can be read by any subject.
171 */
172 if ((request & MAY_ANYREAD) == request) {
173 if (object_label == smack_known_floor.smk_known ||
174 strcmp(object_label, smack_known_floor.smk_known) == 0)
175 goto out_audit;
176 if (subject_label == smack_known_hat.smk_known ||
177 strcmp(subject_label, smack_known_hat.smk_known) == 0)
178 goto out_audit;
179 }
180 /*
181 * Beyond here an explicit relationship is required.
182 * If the requested access is contained in the available
183 * access (e.g. read is included in readwrite) it's
184 * good. A negative response from smk_access_entry()
185 * indicates there is no entry for this pair.
186 */
187 rcu_read_lock();
188 may = smk_access_entry(subject_label, object_label, &smack_rule_list);
189 rcu_read_unlock();
190
191 if (may > 0 && (request & may) == request)
192 goto out_audit;
193
194 rc = -EACCES;
195out_audit:
196#ifdef CONFIG_AUDIT
197 if (a)
198 smack_log(subject_label, object_label, request, rc, a);
199#endif
200 return rc;
201}
202
203/**
204 * smk_curacc - determine if current has a specific access to an object
205 * @obj_label: a pointer to the object's Smack label
206 * @mode: the access requested, in "MAY" format
207 * @a : common audit data
208 *
209 * This function checks the current subject label/object label pair
210 * in the access rule list and returns 0 if the access is permitted,
211 * non zero otherwise. It allows that current may have the capability
212 * to override the rules.
213 */
214int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
215{
216 struct task_smack *tsp = current_security();
217 char *sp = smk_of_task(tsp);
218 int may;
219 int rc;
220
221 /*
222 * Check the global rule list
223 */
224 rc = smk_access(sp, obj_label, mode, NULL);
225 if (rc == 0) {
226 /*
227 * If there is an entry in the task's rule list
228 * it can further restrict access.
229 */
230 may = smk_access_entry(sp, obj_label, &tsp->smk_rules);
231 if (may < 0)
232 goto out_audit;
233 if ((mode & may) == mode)
234 goto out_audit;
235 rc = -EACCES;
236 }
237
238 /*
239 * Return if a specific label has been designated as the
240 * only one that gets privilege and current does not
241 * have that label.
242 */
243 if (smack_onlycap != NULL && smack_onlycap != sp)
244 goto out_audit;
245
246 if (capable(CAP_MAC_OVERRIDE))
247 rc = 0;
248
249out_audit:
250#ifdef CONFIG_AUDIT
251 if (a)
252 smack_log(sp, obj_label, mode, rc, a);
253#endif
254 return rc;
255}
256
257#ifdef CONFIG_AUDIT
258/**
259 * smack_str_from_perm : helper to transalate an int to a
260 * readable string
261 * @string : the string to fill
262 * @access : the int
263 *
264 */
265static inline void smack_str_from_perm(char *string, int access)
266{
267 int i = 0;
268 if (access & MAY_READ)
269 string[i++] = 'r';
270 if (access & MAY_WRITE)
271 string[i++] = 'w';
272 if (access & MAY_EXEC)
273 string[i++] = 'x';
274 if (access & MAY_APPEND)
275 string[i++] = 'a';
276 string[i] = '\0';
277}
278/**
279 * smack_log_callback - SMACK specific information
280 * will be called by generic audit code
281 * @ab : the audit_buffer
282 * @a : audit_data
283 *
284 */
285static void smack_log_callback(struct audit_buffer *ab, void *a)
286{
287 struct common_audit_data *ad = a;
288 struct smack_audit_data *sad = &ad->smack_audit_data;
289 audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
290 ad->smack_audit_data.function,
291 sad->result ? "denied" : "granted");
292 audit_log_format(ab, " subject=");
293 audit_log_untrustedstring(ab, sad->subject);
294 audit_log_format(ab, " object=");
295 audit_log_untrustedstring(ab, sad->object);
296 audit_log_format(ab, " requested=%s", sad->request);
297}
298
299/**
300 * smack_log - Audit the granting or denial of permissions.
301 * @subject_label : smack label of the requester
302 * @object_label : smack label of the object being accessed
303 * @request: requested permissions
304 * @result: result from smk_access
305 * @a: auxiliary audit data
306 *
307 * Audit the granting or denial of permissions in accordance
308 * with the policy.
309 */
310void smack_log(char *subject_label, char *object_label, int request,
311 int result, struct smk_audit_info *ad)
312{
313 char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
314 struct smack_audit_data *sad;
315 struct common_audit_data *a = &ad->a;
316
317 /* check if we have to log the current event */
318 if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
319 return;
320 if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
321 return;
322
323 if (a->smack_audit_data.function == NULL)
324 a->smack_audit_data.function = "unknown";
325
326 /* end preparing the audit data */
327 sad = &a->smack_audit_data;
328 smack_str_from_perm(request_buffer, request);
329 sad->subject = subject_label;
330 sad->object = object_label;
331 sad->request = request_buffer;
332 sad->result = result;
333 a->lsm_pre_audit = smack_log_callback;
334
335 common_lsm_audit(a);
336}
337#else /* #ifdef CONFIG_AUDIT */
338void smack_log(char *subject_label, char *object_label, int request,
339 int result, struct smk_audit_info *ad)
340{
341}
342#endif
343
344static DEFINE_MUTEX(smack_known_lock);
345
346/**
347 * smk_import_entry - import a label, return the list entry
348 * @string: a text string that might be a Smack label
349 * @len: the maximum size, or zero if it is NULL terminated.
350 *
351 * Returns a pointer to the entry in the label list that
352 * matches the passed string, adding it if necessary.
353 */
354struct smack_known *smk_import_entry(const char *string, int len)
355{
356 struct smack_known *skp;
357 char smack[SMK_LABELLEN];
358 int found;
359 int i;
360
361 if (len <= 0 || len > SMK_MAXLEN)
362 len = SMK_MAXLEN;
363
364 for (i = 0, found = 0; i < SMK_LABELLEN; i++) {
365 if (found)
366 smack[i] = '\0';
367 else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
368 string[i] == '/' || string[i] == '"' ||
369 string[i] == '\\' || string[i] == '\'') {
370 smack[i] = '\0';
371 found = 1;
372 } else
373 smack[i] = string[i];
374 }
375
376 if (smack[0] == '\0')
377 return NULL;
378
379 mutex_lock(&smack_known_lock);
380
381 found = 0;
382 list_for_each_entry_rcu(skp, &smack_known_list, list) {
383 if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
384 found = 1;
385 break;
386 }
387 }
388
389 if (found == 0) {
390 skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
391 if (skp != NULL) {
392 strncpy(skp->smk_known, smack, SMK_MAXLEN);
393 skp->smk_secid = smack_next_secid++;
394 skp->smk_cipso = NULL;
395 spin_lock_init(&skp->smk_cipsolock);
396 /*
397 * Make sure that the entry is actually
398 * filled before putting it on the list.
399 */
400 list_add_rcu(&skp->list, &smack_known_list);
401 }
402 }
403
404 mutex_unlock(&smack_known_lock);
405
406 return skp;
407}
408
409/**
410 * smk_import - import a smack label
411 * @string: a text string that might be a Smack label
412 * @len: the maximum size, or zero if it is NULL terminated.
413 *
414 * Returns a pointer to the label in the label list that
415 * matches the passed string, adding it if necessary.
416 */
417char *smk_import(const char *string, int len)
418{
419 struct smack_known *skp;
420
421 /* labels cannot begin with a '-' */
422 if (string[0] == '-')
423 return NULL;
424 skp = smk_import_entry(string, len);
425 if (skp == NULL)
426 return NULL;
427 return skp->smk_known;
428}
429
430/**
431 * smack_from_secid - find the Smack label associated with a secid
432 * @secid: an integer that might be associated with a Smack label
433 *
434 * Returns a pointer to the appropriate Smack label if there is one,
435 * otherwise a pointer to the invalid Smack label.
436 */
437char *smack_from_secid(const u32 secid)
438{
439 struct smack_known *skp;
440
441 rcu_read_lock();
442 list_for_each_entry_rcu(skp, &smack_known_list, list) {
443 if (skp->smk_secid == secid) {
444 rcu_read_unlock();
445 return skp->smk_known;
446 }
447 }
448
449 /*
450 * If we got this far someone asked for the translation
451 * of a secid that is not on the list.
452 */
453 rcu_read_unlock();
454 return smack_known_invalid.smk_known;
455}
456
457/**
458 * smack_to_secid - find the secid associated with a Smack label
459 * @smack: the Smack label
460 *
461 * Returns the appropriate secid if there is one,
462 * otherwise 0
463 */
464u32 smack_to_secid(const char *smack)
465{
466 struct smack_known *skp;
467
468 rcu_read_lock();
469 list_for_each_entry_rcu(skp, &smack_known_list, list) {
470 if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
471 rcu_read_unlock();
472 return skp->smk_secid;
473 }
474 }
475 rcu_read_unlock();
476 return 0;
477}
478
479/**
480 * smack_from_cipso - find the Smack label associated with a CIPSO option
481 * @level: Bell & LaPadula level from the network
482 * @cp: Bell & LaPadula categories from the network
483 * @result: where to put the Smack value
484 *
485 * This is a simple lookup in the label table.
486 *
487 * This is an odd duck as far as smack handling goes in that
488 * it sends back a copy of the smack label rather than a pointer
489 * to the master list. This is done because it is possible for
490 * a foreign host to send a smack label that is new to this
491 * machine and hence not on the list. That would not be an
492 * issue except that adding an entry to the master list can't
493 * be done at that point.
494 */
495void smack_from_cipso(u32 level, char *cp, char *result)
496{
497 struct smack_known *kp;
498 char *final = NULL;
499
500 rcu_read_lock();
501 list_for_each_entry(kp, &smack_known_list, list) {
502 if (kp->smk_cipso == NULL)
503 continue;
504
505 spin_lock_bh(&kp->smk_cipsolock);
506
507 if (kp->smk_cipso->smk_level == level &&
508 memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0)
509 final = kp->smk_known;
510
511 spin_unlock_bh(&kp->smk_cipsolock);
512 }
513 rcu_read_unlock();
514 if (final == NULL)
515 final = smack_known_huh.smk_known;
516 strncpy(result, final, SMK_MAXLEN);
517 return;
518}
519
520/**
521 * smack_to_cipso - find the CIPSO option to go with a Smack label
522 * @smack: a pointer to the smack label in question
523 * @cp: where to put the result
524 *
525 * Returns zero if a value is available, non-zero otherwise.
526 */
527int smack_to_cipso(const char *smack, struct smack_cipso *cp)
528{
529 struct smack_known *kp;
530 int found = 0;
531
532 rcu_read_lock();
533 list_for_each_entry_rcu(kp, &smack_known_list, list) {
534 if (kp->smk_known == smack ||
535 strcmp(kp->smk_known, smack) == 0) {
536 found = 1;
537 break;
538 }
539 }
540 rcu_read_unlock();
541
542 if (found == 0 || kp->smk_cipso == NULL)
543 return -ENOENT;
544
545 memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
546 return 0;
547}
1/*
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 * Author:
9 * Casey Schaufler <casey@schaufler-ca.com>
10 *
11 */
12
13#include <linux/types.h>
14#include <linux/slab.h>
15#include <linux/fs.h>
16#include <linux/sched.h>
17#include "smack.h"
18
19struct smack_known smack_known_huh = {
20 .smk_known = "?",
21 .smk_secid = 2,
22};
23
24struct smack_known smack_known_hat = {
25 .smk_known = "^",
26 .smk_secid = 3,
27};
28
29struct smack_known smack_known_star = {
30 .smk_known = "*",
31 .smk_secid = 4,
32};
33
34struct smack_known smack_known_floor = {
35 .smk_known = "_",
36 .smk_secid = 5,
37};
38
39struct smack_known smack_known_invalid = {
40 .smk_known = "",
41 .smk_secid = 6,
42};
43
44struct smack_known smack_known_web = {
45 .smk_known = "@",
46 .smk_secid = 7,
47};
48
49LIST_HEAD(smack_known_list);
50
51/*
52 * The initial value needs to be bigger than any of the
53 * known values above.
54 */
55static u32 smack_next_secid = 10;
56
57/*
58 * what events do we log
59 * can be overwritten at run-time by /smack/logging
60 */
61int log_policy = SMACK_AUDIT_DENIED;
62
63/**
64 * smk_access_entry - look up matching access rule
65 * @subject_label: a pointer to the subject's Smack label
66 * @object_label: a pointer to the object's Smack label
67 * @rule_list: the list of rules to search
68 *
69 * This function looks up the subject/object pair in the
70 * access rule list and returns the access mode. If no
71 * entry is found returns -ENOENT.
72 *
73 * NOTE:
74 *
75 * Earlier versions of this function allowed for labels that
76 * were not on the label list. This was done to allow for
77 * labels to come over the network that had never been seen
78 * before on this host. Unless the receiving socket has the
79 * star label this will always result in a failure check. The
80 * star labeled socket case is now handled in the networking
81 * hooks so there is no case where the label is not on the
82 * label list. Checking to see if the address of two labels
83 * is the same is now a reliable test.
84 *
85 * Do the object check first because that is more
86 * likely to differ.
87 *
88 * Allowing write access implies allowing locking.
89 */
90int smk_access_entry(char *subject_label, char *object_label,
91 struct list_head *rule_list)
92{
93 int may = -ENOENT;
94 struct smack_rule *srp;
95
96 list_for_each_entry_rcu(srp, rule_list, list) {
97 if (srp->smk_object == object_label &&
98 srp->smk_subject->smk_known == subject_label) {
99 may = srp->smk_access;
100 break;
101 }
102 }
103
104 /*
105 * MAY_WRITE implies MAY_LOCK.
106 */
107 if ((may & MAY_WRITE) == MAY_WRITE)
108 may |= MAY_LOCK;
109 return may;
110}
111
112/**
113 * smk_access - determine if a subject has a specific access to an object
114 * @subject_known: a pointer to the subject's Smack label entry
115 * @object_label: a pointer to the object's Smack label
116 * @request: the access requested, in "MAY" format
117 * @a : a pointer to the audit data
118 *
119 * This function looks up the subject/object pair in the
120 * access rule list and returns 0 if the access is permitted,
121 * non zero otherwise.
122 *
123 * Smack labels are shared on smack_list
124 */
125int smk_access(struct smack_known *subject_known, char *object_label,
126 int request, struct smk_audit_info *a)
127{
128 int may = MAY_NOT;
129 int rc = 0;
130
131 /*
132 * Hardcoded comparisons.
133 *
134 * A star subject can't access any object.
135 */
136 if (subject_known == &smack_known_star) {
137 rc = -EACCES;
138 goto out_audit;
139 }
140 /*
141 * An internet object can be accessed by any subject.
142 * Tasks cannot be assigned the internet label.
143 * An internet subject can access any object.
144 */
145 if (object_label == smack_known_web.smk_known ||
146 subject_known == &smack_known_web)
147 goto out_audit;
148 /*
149 * A star object can be accessed by any subject.
150 */
151 if (object_label == smack_known_star.smk_known)
152 goto out_audit;
153 /*
154 * An object can be accessed in any way by a subject
155 * with the same label.
156 */
157 if (subject_known->smk_known == object_label)
158 goto out_audit;
159 /*
160 * A hat subject can read any object.
161 * A floor object can be read by any subject.
162 */
163 if ((request & MAY_ANYREAD) == request) {
164 if (object_label == smack_known_floor.smk_known)
165 goto out_audit;
166 if (subject_known == &smack_known_hat)
167 goto out_audit;
168 }
169 /*
170 * Beyond here an explicit relationship is required.
171 * If the requested access is contained in the available
172 * access (e.g. read is included in readwrite) it's
173 * good. A negative response from smk_access_entry()
174 * indicates there is no entry for this pair.
175 */
176 rcu_read_lock();
177 may = smk_access_entry(subject_known->smk_known, object_label,
178 &subject_known->smk_rules);
179 rcu_read_unlock();
180
181 if (may > 0 && (request & may) == request)
182 goto out_audit;
183
184 rc = -EACCES;
185out_audit:
186#ifdef CONFIG_AUDIT
187 if (a)
188 smack_log(subject_known->smk_known, object_label, request,
189 rc, a);
190#endif
191 return rc;
192}
193
194/**
195 * smk_curacc - determine if current has a specific access to an object
196 * @obj_label: a pointer to the object's Smack label
197 * @mode: the access requested, in "MAY" format
198 * @a : common audit data
199 *
200 * This function checks the current subject label/object label pair
201 * in the access rule list and returns 0 if the access is permitted,
202 * non zero otherwise. It allows that current may have the capability
203 * to override the rules.
204 */
205int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
206{
207 struct task_smack *tsp = current_security();
208 struct smack_known *skp = smk_of_task(tsp);
209 int may;
210 int rc;
211
212 /*
213 * Check the global rule list
214 */
215 rc = smk_access(skp, obj_label, mode, NULL);
216 if (rc == 0) {
217 /*
218 * If there is an entry in the task's rule list
219 * it can further restrict access.
220 */
221 may = smk_access_entry(skp->smk_known, obj_label,
222 &tsp->smk_rules);
223 if (may < 0)
224 goto out_audit;
225 if ((mode & may) == mode)
226 goto out_audit;
227 rc = -EACCES;
228 }
229
230 /*
231 * Allow for priviliged to override policy.
232 */
233 if (rc != 0 && smack_privileged(CAP_MAC_OVERRIDE))
234 rc = 0;
235
236out_audit:
237#ifdef CONFIG_AUDIT
238 if (a)
239 smack_log(skp->smk_known, obj_label, mode, rc, a);
240#endif
241 return rc;
242}
243
244#ifdef CONFIG_AUDIT
245/**
246 * smack_str_from_perm : helper to transalate an int to a
247 * readable string
248 * @string : the string to fill
249 * @access : the int
250 *
251 */
252static inline void smack_str_from_perm(char *string, int access)
253{
254 int i = 0;
255
256 if (access & MAY_READ)
257 string[i++] = 'r';
258 if (access & MAY_WRITE)
259 string[i++] = 'w';
260 if (access & MAY_EXEC)
261 string[i++] = 'x';
262 if (access & MAY_APPEND)
263 string[i++] = 'a';
264 if (access & MAY_TRANSMUTE)
265 string[i++] = 't';
266 if (access & MAY_LOCK)
267 string[i++] = 'l';
268 string[i] = '\0';
269}
270/**
271 * smack_log_callback - SMACK specific information
272 * will be called by generic audit code
273 * @ab : the audit_buffer
274 * @a : audit_data
275 *
276 */
277static void smack_log_callback(struct audit_buffer *ab, void *a)
278{
279 struct common_audit_data *ad = a;
280 struct smack_audit_data *sad = ad->smack_audit_data;
281 audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
282 ad->smack_audit_data->function,
283 sad->result ? "denied" : "granted");
284 audit_log_format(ab, " subject=");
285 audit_log_untrustedstring(ab, sad->subject);
286 audit_log_format(ab, " object=");
287 audit_log_untrustedstring(ab, sad->object);
288 audit_log_format(ab, " requested=%s", sad->request);
289}
290
291/**
292 * smack_log - Audit the granting or denial of permissions.
293 * @subject_label : smack label of the requester
294 * @object_label : smack label of the object being accessed
295 * @request: requested permissions
296 * @result: result from smk_access
297 * @a: auxiliary audit data
298 *
299 * Audit the granting or denial of permissions in accordance
300 * with the policy.
301 */
302void smack_log(char *subject_label, char *object_label, int request,
303 int result, struct smk_audit_info *ad)
304{
305 char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
306 struct smack_audit_data *sad;
307 struct common_audit_data *a = &ad->a;
308
309 /* check if we have to log the current event */
310 if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
311 return;
312 if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
313 return;
314
315 sad = a->smack_audit_data;
316
317 if (sad->function == NULL)
318 sad->function = "unknown";
319
320 /* end preparing the audit data */
321 smack_str_from_perm(request_buffer, request);
322 sad->subject = subject_label;
323 sad->object = object_label;
324 sad->request = request_buffer;
325 sad->result = result;
326
327 common_lsm_audit(a, smack_log_callback, NULL);
328}
329#else /* #ifdef CONFIG_AUDIT */
330void smack_log(char *subject_label, char *object_label, int request,
331 int result, struct smk_audit_info *ad)
332{
333}
334#endif
335
336DEFINE_MUTEX(smack_known_lock);
337
338struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
339
340/**
341 * smk_insert_entry - insert a smack label into a hash map,
342 *
343 * this function must be called under smack_known_lock
344 */
345void smk_insert_entry(struct smack_known *skp)
346{
347 unsigned int hash;
348 struct hlist_head *head;
349
350 hash = full_name_hash(skp->smk_known, strlen(skp->smk_known));
351 head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)];
352
353 hlist_add_head_rcu(&skp->smk_hashed, head);
354 list_add_rcu(&skp->list, &smack_known_list);
355}
356
357/**
358 * smk_find_entry - find a label on the list, return the list entry
359 * @string: a text string that might be a Smack label
360 *
361 * Returns a pointer to the entry in the label list that
362 * matches the passed string.
363 */
364struct smack_known *smk_find_entry(const char *string)
365{
366 unsigned int hash;
367 struct hlist_head *head;
368 struct smack_known *skp;
369
370 hash = full_name_hash(string, strlen(string));
371 head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)];
372
373 hlist_for_each_entry_rcu(skp, head, smk_hashed)
374 if (strcmp(skp->smk_known, string) == 0)
375 return skp;
376
377 return NULL;
378}
379
380/**
381 * smk_parse_smack - parse smack label from a text string
382 * @string: a text string that might contain a Smack label
383 * @len: the maximum size, or zero if it is NULL terminated.
384 *
385 * Returns a pointer to the clean label, or NULL
386 */
387char *smk_parse_smack(const char *string, int len)
388{
389 char *smack;
390 int i;
391
392 if (len <= 0)
393 len = strlen(string) + 1;
394
395 /*
396 * Reserve a leading '-' as an indicator that
397 * this isn't a label, but an option to interfaces
398 * including /smack/cipso and /smack/cipso2
399 */
400 if (string[0] == '-')
401 return NULL;
402
403 for (i = 0; i < len; i++)
404 if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' ||
405 string[i] == '"' || string[i] == '\\' || string[i] == '\'')
406 break;
407
408 if (i == 0 || i >= SMK_LONGLABEL)
409 return NULL;
410
411 smack = kzalloc(i + 1, GFP_KERNEL);
412 if (smack != NULL) {
413 strncpy(smack, string, i + 1);
414 smack[i] = '\0';
415 }
416 return smack;
417}
418
419/**
420 * smk_netlbl_mls - convert a catset to netlabel mls categories
421 * @catset: the Smack categories
422 * @sap: where to put the netlabel categories
423 *
424 * Allocates and fills attr.mls
425 * Returns 0 on success, error code on failure.
426 */
427int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
428 int len)
429{
430 unsigned char *cp;
431 unsigned char m;
432 int cat;
433 int rc;
434 int byte;
435
436 sap->flags |= NETLBL_SECATTR_MLS_CAT;
437 sap->attr.mls.lvl = level;
438 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
439 if (!sap->attr.mls.cat)
440 return -ENOMEM;
441 sap->attr.mls.cat->startbit = 0;
442
443 for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++)
444 for (m = 0x80; m != 0; m >>= 1, cat++) {
445 if ((m & *cp) == 0)
446 continue;
447 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
448 cat, GFP_ATOMIC);
449 if (rc < 0) {
450 netlbl_secattr_catmap_free(sap->attr.mls.cat);
451 return rc;
452 }
453 }
454
455 return 0;
456}
457
458/**
459 * smk_import_entry - import a label, return the list entry
460 * @string: a text string that might be a Smack label
461 * @len: the maximum size, or zero if it is NULL terminated.
462 *
463 * Returns a pointer to the entry in the label list that
464 * matches the passed string, adding it if necessary.
465 */
466struct smack_known *smk_import_entry(const char *string, int len)
467{
468 struct smack_known *skp;
469 char *smack;
470 int slen;
471 int rc;
472
473 smack = smk_parse_smack(string, len);
474 if (smack == NULL)
475 return NULL;
476
477 mutex_lock(&smack_known_lock);
478
479 skp = smk_find_entry(smack);
480 if (skp != NULL)
481 goto freeout;
482
483 skp = kzalloc(sizeof(*skp), GFP_KERNEL);
484 if (skp == NULL)
485 goto freeout;
486
487 skp->smk_known = smack;
488 skp->smk_secid = smack_next_secid++;
489 skp->smk_netlabel.domain = skp->smk_known;
490 skp->smk_netlabel.flags =
491 NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
492 /*
493 * If direct labeling works use it.
494 * Otherwise use mapped labeling.
495 */
496 slen = strlen(smack);
497 if (slen < SMK_CIPSOLEN)
498 rc = smk_netlbl_mls(smack_cipso_direct, skp->smk_known,
499 &skp->smk_netlabel, slen);
500 else
501 rc = smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid,
502 &skp->smk_netlabel, sizeof(skp->smk_secid));
503
504 if (rc >= 0) {
505 INIT_LIST_HEAD(&skp->smk_rules);
506 mutex_init(&skp->smk_rules_lock);
507 /*
508 * Make sure that the entry is actually
509 * filled before putting it on the list.
510 */
511 smk_insert_entry(skp);
512 goto unlockout;
513 }
514 /*
515 * smk_netlbl_mls failed.
516 */
517 kfree(skp);
518 skp = NULL;
519freeout:
520 kfree(smack);
521unlockout:
522 mutex_unlock(&smack_known_lock);
523
524 return skp;
525}
526
527/**
528 * smk_import - import a smack label
529 * @string: a text string that might be a Smack label
530 * @len: the maximum size, or zero if it is NULL terminated.
531 *
532 * Returns a pointer to the label in the label list that
533 * matches the passed string, adding it if necessary.
534 */
535char *smk_import(const char *string, int len)
536{
537 struct smack_known *skp;
538
539 /* labels cannot begin with a '-' */
540 if (string[0] == '-')
541 return NULL;
542 skp = smk_import_entry(string, len);
543 if (skp == NULL)
544 return NULL;
545 return skp->smk_known;
546}
547
548/**
549 * smack_from_secid - find the Smack label associated with a secid
550 * @secid: an integer that might be associated with a Smack label
551 *
552 * Returns a pointer to the appropriate Smack label entry if there is one,
553 * otherwise a pointer to the invalid Smack label.
554 */
555struct smack_known *smack_from_secid(const u32 secid)
556{
557 struct smack_known *skp;
558
559 rcu_read_lock();
560 list_for_each_entry_rcu(skp, &smack_known_list, list) {
561 if (skp->smk_secid == secid) {
562 rcu_read_unlock();
563 return skp;
564 }
565 }
566
567 /*
568 * If we got this far someone asked for the translation
569 * of a secid that is not on the list.
570 */
571 rcu_read_unlock();
572 return &smack_known_invalid;
573}
574
575/**
576 * smack_to_secid - find the secid associated with a Smack label
577 * @smack: the Smack label
578 *
579 * Returns the appropriate secid if there is one,
580 * otherwise 0
581 */
582u32 smack_to_secid(const char *smack)
583{
584 struct smack_known *skp = smk_find_entry(smack);
585
586 if (skp == NULL)
587 return 0;
588 return skp->smk_secid;
589}