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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 * Author:
9 * Casey Schaufler <casey@schaufler-ca.com>
10 *
11 */
12
13#include <linux/types.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Casey Schauflere114e472008-02-04 22:29:50 -080015#include <linux/fs.h>
16#include <linux/sched.h>
17#include "smack.h"
18
Casey Schauflere114e472008-02-04 22:29:50 -080019struct smack_known smack_known_huh = {
Casey Schauflere114e472008-02-04 22:29:50 -080020 .smk_known = "?",
21 .smk_secid = 2,
Casey Schauflere114e472008-02-04 22:29:50 -080022};
23
24struct smack_known smack_known_hat = {
Casey Schauflere114e472008-02-04 22:29:50 -080025 .smk_known = "^",
26 .smk_secid = 3,
Casey Schauflere114e472008-02-04 22:29:50 -080027};
28
29struct smack_known smack_known_star = {
Casey Schauflere114e472008-02-04 22:29:50 -080030 .smk_known = "*",
31 .smk_secid = 4,
Casey Schauflere114e472008-02-04 22:29:50 -080032};
33
34struct smack_known smack_known_floor = {
Casey Schauflere114e472008-02-04 22:29:50 -080035 .smk_known = "_",
36 .smk_secid = 5,
Casey Schauflere114e472008-02-04 22:29:50 -080037};
38
39struct smack_known smack_known_invalid = {
Casey Schauflere114e472008-02-04 22:29:50 -080040 .smk_known = "",
41 .smk_secid = 6,
Casey Schauflere114e472008-02-04 22:29:50 -080042};
43
Casey Schaufler6d3dc072008-12-31 12:54:12 -050044struct smack_known smack_known_web = {
Casey Schaufler6d3dc072008-12-31 12:54:12 -050045 .smk_known = "@",
46 .smk_secid = 7,
Casey Schaufler6d3dc072008-12-31 12:54:12 -050047};
48
Etienne Basset7198e2e2009-03-24 20:53:24 +010049LIST_HEAD(smack_known_list);
Casey Schauflere114e472008-02-04 22:29:50 -080050
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
Etienne Bassetecfcc532009-04-08 20:40:06 +020057/*
58 * what events do we log
59 * can be overwritten at run-time by /smack/logging
60 */
61int log_policy = SMACK_AUDIT_DENIED;
62
Casey Schauflere114e472008-02-04 22:29:50 -080063/**
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020064 * 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
Casey Schaufler7898e1f2011-01-17 08:05:27 -080067 * @rule_list: the list of rules to search
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020068 *
69 * This function looks up the subject/object pair in the
Casey Schaufler7898e1f2011-01-17 08:05:27 -080070 * access rule list and returns the access mode. If no
71 * entry is found returns -ENOENT.
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020072 *
73 * NOTE:
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020074 *
Casey Schaufler272cd7a2011-09-20 12:24:36 -070075 * 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.
Casey Schauflerc0ab6e52013-10-11 18:06:39 -070087 *
88 * Allowing write access implies allowing locking.
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020089 */
Casey Schaufler7898e1f2011-01-17 08:05:27 -080090int smk_access_entry(char *subject_label, char *object_label,
91 struct list_head *rule_list)
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020092{
Casey Schaufler7898e1f2011-01-17 08:05:27 -080093 int may = -ENOENT;
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +020094 struct smack_rule *srp;
95
Casey Schaufler7898e1f2011-01-17 08:05:27 -080096 list_for_each_entry_rcu(srp, rule_list, list) {
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +020097 if (srp->smk_object->smk_known == object_label &&
Casey Schaufler2f823ff2013-05-22 18:43:03 -070098 srp->smk_subject->smk_known == subject_label) {
Casey Schaufler272cd7a2011-09-20 12:24:36 -070099 may = srp->smk_access;
100 break;
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +0200101 }
102 }
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +0200103
Casey Schauflerc0ab6e52013-10-11 18:06:39 -0700104 /*
105 * MAY_WRITE implies MAY_LOCK.
106 */
107 if ((may & MAY_WRITE) == MAY_WRITE)
108 may |= MAY_LOCK;
Jarkko Sakkinen5c6d1122010-12-07 13:34:01 +0200109 return may;
110}
111
112/**
Casey Schauflere114e472008-02-04 22:29:50 -0800113 * smk_access - determine if a subject has a specific access to an object
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200114 * @subject: a pointer to the subject's Smack label entry
115 * @object: a pointer to the object's Smack label entry
Casey Schauflere114e472008-02-04 22:29:50 -0800116 * @request: the access requested, in "MAY" format
Etienne Bassetecfcc532009-04-08 20:40:06 +0200117 * @a : a pointer to the audit data
Casey Schauflere114e472008-02-04 22:29:50 -0800118 *
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 *
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700123 * Smack labels are shared on smack_list
Casey Schauflere114e472008-02-04 22:29:50 -0800124 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200125int smk_access(struct smack_known *subject, struct smack_known *object,
126 int request, struct smk_audit_info *a)
Casey Schauflere114e472008-02-04 22:29:50 -0800127{
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800128 int may = MAY_NOT;
Etienne Bassetecfcc532009-04-08 20:40:06 +0200129 int rc = 0;
Casey Schauflere114e472008-02-04 22:29:50 -0800130
131 /*
132 * Hardcoded comparisons.
133 *
134 * A star subject can't access any object.
135 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200136 if (subject == &smack_known_star) {
Etienne Bassetecfcc532009-04-08 20:40:06 +0200137 rc = -EACCES;
138 goto out_audit;
139 }
Casey Schauflere114e472008-02-04 22:29:50 -0800140 /*
Casey Schaufler6d3dc072008-12-31 12:54:12 -0500141 * 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 */
Casey Schaufler6c892df2014-10-09 16:18:55 -0700145 if (object == &smack_known_web || subject == &smack_known_web)
Etienne Bassetecfcc532009-04-08 20:40:06 +0200146 goto out_audit;
Casey Schaufler6d3dc072008-12-31 12:54:12 -0500147 /*
Casey Schauflere114e472008-02-04 22:29:50 -0800148 * A star object can be accessed by any subject.
149 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200150 if (object == &smack_known_star)
Etienne Bassetecfcc532009-04-08 20:40:06 +0200151 goto out_audit;
Casey Schauflere114e472008-02-04 22:29:50 -0800152 /*
153 * An object can be accessed in any way by a subject
154 * with the same label.
155 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200156 if (subject->smk_known == object->smk_known)
Etienne Bassetecfcc532009-04-08 20:40:06 +0200157 goto out_audit;
Casey Schauflere114e472008-02-04 22:29:50 -0800158 /*
Casey Schaufler6c892df2014-10-09 16:18:55 -0700159 * A hat subject can read or lock any object.
160 * A floor object can be read or locked by any subject.
Casey Schauflere114e472008-02-04 22:29:50 -0800161 */
Casey Schaufler6c892df2014-10-09 16:18:55 -0700162 if ((request & MAY_ANYREAD) == request ||
163 (request & MAY_LOCK) == request) {
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200164 if (object == &smack_known_floor)
Etienne Bassetecfcc532009-04-08 20:40:06 +0200165 goto out_audit;
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200166 if (subject == &smack_known_hat)
Etienne Bassetecfcc532009-04-08 20:40:06 +0200167 goto out_audit;
Casey Schauflere114e472008-02-04 22:29:50 -0800168 }
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
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800173 * good. A negative response from smk_access_entry()
174 * indicates there is no entry for this pair.
Casey Schauflere114e472008-02-04 22:29:50 -0800175 */
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800176 rcu_read_lock();
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200177 may = smk_access_entry(subject->smk_known, object->smk_known,
178 &subject->smk_rules);
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800179 rcu_read_unlock();
180
Casey Schauflerd166c802014-08-27 14:51:27 -0700181 if (may <= 0 || (request & may) != request) {
182 rc = -EACCES;
Etienne Bassetecfcc532009-04-08 20:40:06 +0200183 goto out_audit;
Casey Schauflerd166c802014-08-27 14:51:27 -0700184 }
185#ifdef CONFIG_SECURITY_SMACK_BRINGUP
186 /*
187 * Return a positive value if using bringup mode.
188 * This allows the hooks to identify checks that
189 * succeed because of "b" rules.
190 */
191 if (may & MAY_BRINGUP)
192 rc = MAY_BRINGUP;
193#endif
Casey Schauflere114e472008-02-04 22:29:50 -0800194
Etienne Bassetecfcc532009-04-08 20:40:06 +0200195out_audit:
196#ifdef CONFIG_AUDIT
197 if (a)
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200198 smack_log(subject->smk_known, object->smk_known,
199 request, rc, a);
Etienne Bassetecfcc532009-04-08 20:40:06 +0200200#endif
Casey Schauflerd166c802014-08-27 14:51:27 -0700201
Etienne Bassetecfcc532009-04-08 20:40:06 +0200202 return rc;
Casey Schauflere114e472008-02-04 22:29:50 -0800203}
204
205/**
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100206 * smk_tskacc - determine if a task has a specific access to an object
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200207 * @tsp: a pointer to the subject's task
208 * @obj_known: a pointer to the object's label entry
Randy Dunlap251a2a92009-02-18 11:42:33 -0800209 * @mode: the access requested, in "MAY" format
Etienne Bassetecfcc532009-04-08 20:40:06 +0200210 * @a : common audit data
Casey Schauflere114e472008-02-04 22:29:50 -0800211 *
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100212 * This function checks the subject task's label/object label pair
Casey Schauflere114e472008-02-04 22:29:50 -0800213 * in the access rule list and returns 0 if the access is permitted,
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100214 * non zero otherwise. It allows that the task may have the capability
Casey Schauflere114e472008-02-04 22:29:50 -0800215 * to override the rules.
216 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200217int smk_tskacc(struct task_smack *tsp, struct smack_known *obj_known,
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100218 u32 mode, struct smk_audit_info *a)
Casey Schauflere114e472008-02-04 22:29:50 -0800219{
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200220 struct smack_known *sbj_known = smk_of_task(tsp);
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800221 int may;
Casey Schauflere114e472008-02-04 22:29:50 -0800222 int rc;
223
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800224 /*
225 * Check the global rule list
226 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200227 rc = smk_access(sbj_known, obj_known, mode, NULL);
Casey Schauflerd166c802014-08-27 14:51:27 -0700228 if (rc >= 0) {
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800229 /*
230 * If there is an entry in the task's rule list
231 * it can further restrict access.
232 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200233 may = smk_access_entry(sbj_known->smk_known,
234 obj_known->smk_known,
235 &tsp->smk_rules);
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800236 if (may < 0)
237 goto out_audit;
238 if ((mode & may) == mode)
239 goto out_audit;
240 rc = -EACCES;
241 }
Casey Schauflere114e472008-02-04 22:29:50 -0800242
Casey Schaufler15446232008-07-30 15:37:11 -0700243 /*
Casey Schaufler1880eff2012-06-05 15:28:30 -0700244 * Allow for priviliged to override policy.
Casey Schaufler15446232008-07-30 15:37:11 -0700245 */
Casey Schaufler1880eff2012-06-05 15:28:30 -0700246 if (rc != 0 && smack_privileged(CAP_MAC_OVERRIDE))
Casey Schaufler7898e1f2011-01-17 08:05:27 -0800247 rc = 0;
Casey Schauflere114e472008-02-04 22:29:50 -0800248
Etienne Bassetecfcc532009-04-08 20:40:06 +0200249out_audit:
250#ifdef CONFIG_AUDIT
251 if (a)
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200252 smack_log(sbj_known->smk_known, obj_known->smk_known,
253 mode, rc, a);
Etienne Bassetecfcc532009-04-08 20:40:06 +0200254#endif
Casey Schauflere114e472008-02-04 22:29:50 -0800255 return rc;
256}
257
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100258/**
259 * smk_curacc - determine if current has a specific access to an object
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200260 * @obj_known: a pointer to the object's Smack label entry
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100261 * @mode: the access requested, in "MAY" format
262 * @a : common audit data
263 *
264 * This function checks the current subject label/object label pair
265 * in the access rule list and returns 0 if the access is permitted,
266 * non zero otherwise. It allows that current may have the capability
267 * to override the rules.
268 */
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200269int smk_curacc(struct smack_known *obj_known,
270 u32 mode, struct smk_audit_info *a)
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100271{
272 struct task_smack *tsp = current_security();
273
Lukasz Pawelczyk21c7eae2014-08-29 17:02:55 +0200274 return smk_tskacc(tsp, obj_known, mode, a);
Lukasz Pawelczyk959e6c72014-03-11 17:07:04 +0100275}
276
Etienne Bassetecfcc532009-04-08 20:40:06 +0200277#ifdef CONFIG_AUDIT
278/**
279 * smack_str_from_perm : helper to transalate an int to a
280 * readable string
281 * @string : the string to fill
282 * @access : the int
283 *
284 */
285static inline void smack_str_from_perm(char *string, int access)
286{
287 int i = 0;
Casey Schauflerc0ab6e52013-10-11 18:06:39 -0700288
Etienne Bassetecfcc532009-04-08 20:40:06 +0200289 if (access & MAY_READ)
290 string[i++] = 'r';
291 if (access & MAY_WRITE)
292 string[i++] = 'w';
293 if (access & MAY_EXEC)
294 string[i++] = 'x';
295 if (access & MAY_APPEND)
296 string[i++] = 'a';
Rafal Krypaa87d79a2012-11-27 16:29:07 +0100297 if (access & MAY_TRANSMUTE)
298 string[i++] = 't';
Casey Schauflerc0ab6e52013-10-11 18:06:39 -0700299 if (access & MAY_LOCK)
300 string[i++] = 'l';
Etienne Bassetecfcc532009-04-08 20:40:06 +0200301 string[i] = '\0';
302}
303/**
304 * smack_log_callback - SMACK specific information
305 * will be called by generic audit code
306 * @ab : the audit_buffer
307 * @a : audit_data
308 *
309 */
310static void smack_log_callback(struct audit_buffer *ab, void *a)
311{
312 struct common_audit_data *ad = a;
Eric Paris3b3b0e42012-04-03 09:37:02 -0700313 struct smack_audit_data *sad = ad->smack_audit_data;
Thomas Liued5215a2009-07-09 10:00:29 -0400314 audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
Eric Paris3b3b0e42012-04-03 09:37:02 -0700315 ad->smack_audit_data->function,
Etienne Bassetecfcc532009-04-08 20:40:06 +0200316 sad->result ? "denied" : "granted");
317 audit_log_format(ab, " subject=");
318 audit_log_untrustedstring(ab, sad->subject);
319 audit_log_format(ab, " object=");
320 audit_log_untrustedstring(ab, sad->object);
Lukasz Pawelczyk66867812014-03-11 17:07:06 +0100321 if (sad->request[0] == '\0')
322 audit_log_format(ab, " labels_differ");
323 else
324 audit_log_format(ab, " requested=%s", sad->request);
Etienne Bassetecfcc532009-04-08 20:40:06 +0200325}
326
327/**
328 * smack_log - Audit the granting or denial of permissions.
329 * @subject_label : smack label of the requester
330 * @object_label : smack label of the object being accessed
331 * @request: requested permissions
332 * @result: result from smk_access
333 * @a: auxiliary audit data
334 *
335 * Audit the granting or denial of permissions in accordance
336 * with the policy.
337 */
338void smack_log(char *subject_label, char *object_label, int request,
339 int result, struct smk_audit_info *ad)
340{
341 char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
342 struct smack_audit_data *sad;
343 struct common_audit_data *a = &ad->a;
344
Casey Schauflerd166c802014-08-27 14:51:27 -0700345#ifdef CONFIG_SECURITY_SMACK_BRINGUP
346 /*
347 * The result may be positive in bringup mode.
348 */
349 if (result > 0)
350 result = 0;
351#endif
Etienne Bassetecfcc532009-04-08 20:40:06 +0200352 /* check if we have to log the current event */
353 if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
354 return;
355 if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
356 return;
357
Eric Paris3b3b0e42012-04-03 09:37:02 -0700358 sad = a->smack_audit_data;
359
360 if (sad->function == NULL)
361 sad->function = "unknown";
Etienne Bassetecfcc532009-04-08 20:40:06 +0200362
363 /* end preparing the audit data */
Etienne Bassetecfcc532009-04-08 20:40:06 +0200364 smack_str_from_perm(request_buffer, request);
365 sad->subject = subject_label;
366 sad->object = object_label;
367 sad->request = request_buffer;
368 sad->result = result;
Etienne Bassetecfcc532009-04-08 20:40:06 +0200369
Linus Torvaldsb61c37f2012-04-02 15:48:12 -0700370 common_lsm_audit(a, smack_log_callback, NULL);
Etienne Bassetecfcc532009-04-08 20:40:06 +0200371}
372#else /* #ifdef CONFIG_AUDIT */
373void smack_log(char *subject_label, char *object_label, int request,
374 int result, struct smk_audit_info *ad)
375{
376}
377#endif
378
Casey Schauflerf7112e62012-05-06 15:22:02 -0700379DEFINE_MUTEX(smack_known_lock);
Casey Schauflere114e472008-02-04 22:29:50 -0800380
Tomasz Stanislawski4d7cf4a2013-06-11 14:55:13 +0200381struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
382
383/**
384 * smk_insert_entry - insert a smack label into a hash map,
385 *
386 * this function must be called under smack_known_lock
387 */
388void smk_insert_entry(struct smack_known *skp)
389{
390 unsigned int hash;
391 struct hlist_head *head;
392
393 hash = full_name_hash(skp->smk_known, strlen(skp->smk_known));
394 head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)];
395
396 hlist_add_head_rcu(&skp->smk_hashed, head);
397 list_add_rcu(&skp->list, &smack_known_list);
398}
399
Casey Schauflere114e472008-02-04 22:29:50 -0800400/**
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700401 * smk_find_entry - find a label on the list, return the list entry
402 * @string: a text string that might be a Smack label
403 *
404 * Returns a pointer to the entry in the label list that
405 * matches the passed string.
406 */
407struct smack_known *smk_find_entry(const char *string)
408{
Tomasz Stanislawski4d7cf4a2013-06-11 14:55:13 +0200409 unsigned int hash;
410 struct hlist_head *head;
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700411 struct smack_known *skp;
412
Tomasz Stanislawski4d7cf4a2013-06-11 14:55:13 +0200413 hash = full_name_hash(string, strlen(string));
414 head = &smack_known_hash[hash & (SMACK_HASH_SLOTS - 1)];
415
416 hlist_for_each_entry_rcu(skp, head, smk_hashed)
Casey Schauflerf7112e62012-05-06 15:22:02 -0700417 if (strcmp(skp->smk_known, string) == 0)
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700418 return skp;
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700419
420 return NULL;
421}
422
423/**
Jarkko Sakkinen0e94ae12011-10-18 21:21:36 +0300424 * smk_parse_smack - parse smack label from a text string
425 * @string: a text string that might contain a Smack label
Casey Schauflere114e472008-02-04 22:29:50 -0800426 * @len: the maximum size, or zero if it is NULL terminated.
Casey Schauflerf7112e62012-05-06 15:22:02 -0700427 *
428 * Returns a pointer to the clean label, or NULL
Casey Schauflere114e472008-02-04 22:29:50 -0800429 */
Casey Schauflerf7112e62012-05-06 15:22:02 -0700430char *smk_parse_smack(const char *string, int len)
Casey Schauflere114e472008-02-04 22:29:50 -0800431{
Casey Schauflerf7112e62012-05-06 15:22:02 -0700432 char *smack;
Casey Schauflere114e472008-02-04 22:29:50 -0800433 int i;
434
Casey Schauflerf7112e62012-05-06 15:22:02 -0700435 if (len <= 0)
436 len = strlen(string) + 1;
Casey Schauflere114e472008-02-04 22:29:50 -0800437
Casey Schauflerf7112e62012-05-06 15:22:02 -0700438 /*
439 * Reserve a leading '-' as an indicator that
440 * this isn't a label, but an option to interfaces
441 * including /smack/cipso and /smack/cipso2
442 */
443 if (string[0] == '-')
444 return NULL;
445
446 for (i = 0; i < len; i++)
447 if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' ||
448 string[i] == '"' || string[i] == '\\' || string[i] == '\'')
449 break;
450
451 if (i == 0 || i >= SMK_LONGLABEL)
452 return NULL;
453
454 smack = kzalloc(i + 1, GFP_KERNEL);
Andrey Ryabinin5c1b6622014-11-08 17:48:05 +0300455 if (smack != NULL)
456 strncpy(smack, string, i);
457
Casey Schauflerf7112e62012-05-06 15:22:02 -0700458 return smack;
459}
460
461/**
462 * smk_netlbl_mls - convert a catset to netlabel mls categories
463 * @catset: the Smack categories
464 * @sap: where to put the netlabel categories
465 *
466 * Allocates and fills attr.mls
467 * Returns 0 on success, error code on failure.
468 */
469int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
470 int len)
471{
472 unsigned char *cp;
473 unsigned char m;
474 int cat;
475 int rc;
476 int byte;
477
478 sap->flags |= NETLBL_SECATTR_MLS_CAT;
479 sap->attr.mls.lvl = level;
Paul Moore4b8feff2014-08-01 11:17:17 -0400480 sap->attr.mls.cat = NULL;
Casey Schauflerf7112e62012-05-06 15:22:02 -0700481
482 for (cat = 1, cp = catset, byte = 0; byte < len; cp++, byte++)
483 for (m = 0x80; m != 0; m >>= 1, cat++) {
484 if ((m & *cp) == 0)
485 continue;
Paul Moore4fbe63d2014-08-01 11:17:37 -0400486 rc = netlbl_catmap_setbit(&sap->attr.mls.cat,
487 cat, GFP_ATOMIC);
Casey Schauflerf7112e62012-05-06 15:22:02 -0700488 if (rc < 0) {
Paul Moore4fbe63d2014-08-01 11:17:37 -0400489 netlbl_catmap_free(sap->attr.mls.cat);
Casey Schauflerf7112e62012-05-06 15:22:02 -0700490 return rc;
491 }
492 }
493
494 return 0;
Jarkko Sakkinen0e94ae12011-10-18 21:21:36 +0300495}
Casey Schauflere114e472008-02-04 22:29:50 -0800496
Jarkko Sakkinen0e94ae12011-10-18 21:21:36 +0300497/**
498 * smk_import_entry - import a label, return the list entry
499 * @string: a text string that might be a Smack label
500 * @len: the maximum size, or zero if it is NULL terminated.
501 *
502 * Returns a pointer to the entry in the label list that
503 * matches the passed string, adding it if necessary.
504 */
505struct smack_known *smk_import_entry(const char *string, int len)
506{
507 struct smack_known *skp;
Casey Schauflerf7112e62012-05-06 15:22:02 -0700508 char *smack;
509 int slen;
510 int rc;
Jarkko Sakkinen0e94ae12011-10-18 21:21:36 +0300511
Casey Schauflerf7112e62012-05-06 15:22:02 -0700512 smack = smk_parse_smack(string, len);
513 if (smack == NULL)
Casey Schauflere114e472008-02-04 22:29:50 -0800514 return NULL;
515
516 mutex_lock(&smack_known_lock);
517
Casey Schaufler272cd7a2011-09-20 12:24:36 -0700518 skp = smk_find_entry(smack);
Casey Schauflerf7112e62012-05-06 15:22:02 -0700519 if (skp != NULL)
520 goto freeout;
Casey Schauflere114e472008-02-04 22:29:50 -0800521
Casey Schauflerf7112e62012-05-06 15:22:02 -0700522 skp = kzalloc(sizeof(*skp), GFP_KERNEL);
523 if (skp == NULL)
524 goto freeout;
525
526 skp->smk_known = smack;
527 skp->smk_secid = smack_next_secid++;
528 skp->smk_netlabel.domain = skp->smk_known;
529 skp->smk_netlabel.flags =
530 NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
531 /*
532 * If direct labeling works use it.
533 * Otherwise use mapped labeling.
534 */
535 slen = strlen(smack);
536 if (slen < SMK_CIPSOLEN)
537 rc = smk_netlbl_mls(smack_cipso_direct, skp->smk_known,
538 &skp->smk_netlabel, slen);
539 else
540 rc = smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid,
541 &skp->smk_netlabel, sizeof(skp->smk_secid));
542
543 if (rc >= 0) {
544 INIT_LIST_HEAD(&skp->smk_rules);
545 mutex_init(&skp->smk_rules_lock);
546 /*
547 * Make sure that the entry is actually
548 * filled before putting it on the list.
549 */
Tomasz Stanislawski4d7cf4a2013-06-11 14:55:13 +0200550 smk_insert_entry(skp);
Casey Schauflerf7112e62012-05-06 15:22:02 -0700551 goto unlockout;
Casey Schauflere114e472008-02-04 22:29:50 -0800552 }
Casey Schauflerf7112e62012-05-06 15:22:02 -0700553 /*
554 * smk_netlbl_mls failed.
555 */
556 kfree(skp);
557 skp = NULL;
558freeout:
559 kfree(smack);
560unlockout:
Casey Schauflere114e472008-02-04 22:29:50 -0800561 mutex_unlock(&smack_known_lock);
562
563 return skp;
564}
565
566/**
Casey Schauflere114e472008-02-04 22:29:50 -0800567 * smack_from_secid - find the Smack label associated with a secid
568 * @secid: an integer that might be associated with a Smack label
569 *
Casey Schaufler2f823ff2013-05-22 18:43:03 -0700570 * Returns a pointer to the appropriate Smack label entry if there is one,
Casey Schauflere114e472008-02-04 22:29:50 -0800571 * otherwise a pointer to the invalid Smack label.
572 */
Casey Schaufler2f823ff2013-05-22 18:43:03 -0700573struct smack_known *smack_from_secid(const u32 secid)
Casey Schauflere114e472008-02-04 22:29:50 -0800574{
575 struct smack_known *skp;
576
Etienne Basset7198e2e2009-03-24 20:53:24 +0100577 rcu_read_lock();
578 list_for_each_entry_rcu(skp, &smack_known_list, list) {
579 if (skp->smk_secid == secid) {
580 rcu_read_unlock();
Casey Schaufler2f823ff2013-05-22 18:43:03 -0700581 return skp;
Etienne Basset7198e2e2009-03-24 20:53:24 +0100582 }
583 }
Casey Schauflere114e472008-02-04 22:29:50 -0800584
585 /*
586 * If we got this far someone asked for the translation
587 * of a secid that is not on the list.
588 */
Etienne Basset7198e2e2009-03-24 20:53:24 +0100589 rcu_read_unlock();
Casey Schaufler2f823ff2013-05-22 18:43:03 -0700590 return &smack_known_invalid;
Casey Schauflere114e472008-02-04 22:29:50 -0800591}