1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
4  *
5  * Authors:
6  * 	Casey Schaufler <casey@schaufler-ca.com>
7  * 	Ahmed S. Darwish <darwish.07@gmail.com>
8  *
9  * Special thanks to the authors of selinuxfs.
10  *
11  *	Karl MacMillan <kmacmillan@tresys.com>
12  *	James Morris <jmorris@redhat.com>
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/vmalloc.h>
17 #include <linux/security.h>
18 #include <linux/mutex.h>
19 #include <linux/slab.h>
20 #include <net/net_namespace.h>
21 #include <net/cipso_ipv4.h>
22 #include <linux/seq_file.h>
23 #include <linux/ctype.h>
24 #include <linux/audit.h>
25 #include <linux/magic.h>
26 #include <linux/mount.h>
27 #include <linux/fs_context.h>
28 #include "smack.h"
29 
30 #define BEBITS	(sizeof(__be32) * 8)
31 /*
32  * smackfs pseudo filesystem.
33  */
34 
35 enum smk_inos {
36 	SMK_ROOT_INO	= 2,
37 	SMK_LOAD	= 3,	/* load policy */
38 	SMK_CIPSO	= 4,	/* load label -> CIPSO mapping */
39 	SMK_DOI		= 5,	/* CIPSO DOI */
40 	SMK_DIRECT	= 6,	/* CIPSO level indicating direct label */
41 	SMK_AMBIENT	= 7,	/* internet ambient label */
42 	SMK_NET4ADDR	= 8,	/* single label hosts */
43 	SMK_ONLYCAP	= 9,	/* the only "capable" label */
44 	SMK_LOGGING	= 10,	/* logging */
45 	SMK_LOAD_SELF	= 11,	/* task specific rules */
46 	SMK_ACCESSES	= 12,	/* access policy */
47 	SMK_MAPPED	= 13,	/* CIPSO level indicating mapped label */
48 	SMK_LOAD2	= 14,	/* load policy with long labels */
49 	SMK_LOAD_SELF2	= 15,	/* load task specific rules with long labels */
50 	SMK_ACCESS2	= 16,	/* make an access check with long labels */
51 	SMK_CIPSO2	= 17,	/* load long label -> CIPSO mapping */
52 	SMK_REVOKE_SUBJ	= 18,	/* set rules with subject label to '-' */
53 	SMK_CHANGE_RULE	= 19,	/* change or add rules (long labels) */
54 	SMK_SYSLOG	= 20,	/* change syslog label) */
55 	SMK_PTRACE	= 21,	/* set ptrace rule */
56 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
57 	SMK_UNCONFINED	= 22,	/* define an unconfined label */
58 #endif
59 #if IS_ENABLED(CONFIG_IPV6)
60 	SMK_NET6ADDR	= 23,	/* single label IPv6 hosts */
61 #endif /* CONFIG_IPV6 */
62 	SMK_RELABEL_SELF = 24, /* relabel possible without CAP_MAC_ADMIN */
63 };
64 
65 /*
66  * List locks
67  */
68 static DEFINE_MUTEX(smack_cipso_lock);
69 static DEFINE_MUTEX(smack_ambient_lock);
70 static DEFINE_MUTEX(smk_net4addr_lock);
71 #if IS_ENABLED(CONFIG_IPV6)
72 static DEFINE_MUTEX(smk_net6addr_lock);
73 #endif /* CONFIG_IPV6 */
74 
75 /*
76  * This is the "ambient" label for network traffic.
77  * If it isn't somehow marked, use this.
78  * It can be reset via smackfs/ambient
79  */
80 struct smack_known *smack_net_ambient;
81 
82 /*
83  * This is the level in a CIPSO header that indicates a
84  * smack label is contained directly in the category set.
85  * It can be reset via smackfs/direct
86  */
87 int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
88 
89 /*
90  * This is the level in a CIPSO header that indicates a
91  * secid is contained directly in the category set.
92  * It can be reset via smackfs/mapped
93  */
94 int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
95 
96 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
97 /*
98  * Allow one label to be unconfined. This is for
99  * debugging and application bring-up purposes only.
100  * It is bad and wrong, but everyone seems to expect
101  * to have it.
102  */
103 struct smack_known *smack_unconfined;
104 #endif
105 
106 /*
107  * If this value is set restrict syslog use to the label specified.
108  * It can be reset via smackfs/syslog
109  */
110 struct smack_known *smack_syslog_label;
111 
112 /*
113  * Ptrace current rule
114  * SMACK_PTRACE_DEFAULT    regular smack ptrace rules (/proc based)
115  * SMACK_PTRACE_EXACT      labels must match, but can be overriden with
116  *			   CAP_SYS_PTRACE
117  * SMACK_PTRACE_DRACONIAN  labels must match, CAP_SYS_PTRACE has no effect
118  */
119 int smack_ptrace_rule = SMACK_PTRACE_DEFAULT;
120 
121 /*
122  * Certain IP addresses may be designated as single label hosts.
123  * Packets are sent there unlabeled, but only from tasks that
124  * can write to the specified label.
125  */
126 
127 LIST_HEAD(smk_net4addr_list);
128 #if IS_ENABLED(CONFIG_IPV6)
129 LIST_HEAD(smk_net6addr_list);
130 #endif /* CONFIG_IPV6 */
131 
132 /*
133  * Rule lists are maintained for each label.
134  */
135 struct smack_parsed_rule {
136 	struct smack_known	*smk_subject;
137 	struct smack_known	*smk_object;
138 	int			smk_access1;
139 	int			smk_access2;
140 };
141 
142 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
143 
144 /*
145  * Values for parsing cipso rules
146  * SMK_DIGITLEN: Length of a digit field in a rule.
147  * SMK_CIPSOMIN: Minimum possible cipso rule length.
148  * SMK_CIPSOMAX: Maximum possible cipso rule length.
149  */
150 #define SMK_DIGITLEN 4
151 #define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN)
152 #define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN)
153 
154 /*
155  * Values for parsing MAC rules
156  * SMK_ACCESS: Maximum possible combination of access permissions
157  * SMK_ACCESSLEN: Maximum length for a rule access field
158  * SMK_LOADLEN: Smack rule length
159  */
160 #define SMK_OACCESS	"rwxa"
161 #define SMK_ACCESS	"rwxatl"
162 #define SMK_OACCESSLEN	(sizeof(SMK_OACCESS) - 1)
163 #define SMK_ACCESSLEN	(sizeof(SMK_ACCESS) - 1)
164 #define SMK_OLOADLEN	(SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN)
165 #define SMK_LOADLEN	(SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN)
166 
167 /*
168  * Stricly for CIPSO level manipulation.
169  * Set the category bit number in a smack label sized buffer.
170  */
smack_catset_bit(unsigned int cat,char * catsetp)171 static inline void smack_catset_bit(unsigned int cat, char *catsetp)
172 {
173 	if (cat == 0 || cat > (SMK_CIPSOLEN * 8))
174 		return;
175 
176 	catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8);
177 }
178 
179 /**
180  * smk_netlabel_audit_set - fill a netlbl_audit struct
181  * @nap: structure to fill
182  */
smk_netlabel_audit_set(struct netlbl_audit * nap)183 static void smk_netlabel_audit_set(struct netlbl_audit *nap)
184 {
185 	struct smack_known *skp = smk_of_current();
186 
187 	nap->loginuid = audit_get_loginuid(current);
188 	nap->sessionid = audit_get_sessionid(current);
189 	nap->secid = skp->smk_secid;
190 }
191 
192 /*
193  * Value for parsing single label host rules
194  * "1.2.3.4 X"
195  */
196 #define SMK_NETLBLADDRMIN	9
197 
198 /**
199  * smk_set_access - add a rule to the rule list or replace an old rule
200  * @srp: the rule to add or replace
201  * @rule_list: the list of rules
202  * @rule_lock: the rule list lock
203  *
204  * Looks through the current subject/object/access list for
205  * the subject/object pair and replaces the access that was
206  * there. If the pair isn't found add it with the specified
207  * access.
208  *
209  * Returns 0 if nothing goes wrong or -ENOMEM if it fails
210  * during the allocation of the new pair to add.
211  */
smk_set_access(struct smack_parsed_rule * srp,struct list_head * rule_list,struct mutex * rule_lock)212 static int smk_set_access(struct smack_parsed_rule *srp,
213 				struct list_head *rule_list,
214 				struct mutex *rule_lock)
215 {
216 	struct smack_rule *sp;
217 	int found = 0;
218 	int rc = 0;
219 
220 	mutex_lock(rule_lock);
221 
222 	/*
223 	 * Because the object label is less likely to match
224 	 * than the subject label check it first
225 	 */
226 	list_for_each_entry_rcu(sp, rule_list, list) {
227 		if (sp->smk_object == srp->smk_object &&
228 		    sp->smk_subject == srp->smk_subject) {
229 			found = 1;
230 			sp->smk_access |= srp->smk_access1;
231 			sp->smk_access &= ~srp->smk_access2;
232 			break;
233 		}
234 	}
235 
236 	if (found == 0) {
237 		sp = kmem_cache_zalloc(smack_rule_cache, GFP_KERNEL);
238 		if (sp == NULL) {
239 			rc = -ENOMEM;
240 			goto out;
241 		}
242 
243 		sp->smk_subject = srp->smk_subject;
244 		sp->smk_object = srp->smk_object;
245 		sp->smk_access = srp->smk_access1 & ~srp->smk_access2;
246 
247 		list_add_rcu(&sp->list, rule_list);
248 	}
249 
250 out:
251 	mutex_unlock(rule_lock);
252 	return rc;
253 }
254 
255 /**
256  * smk_perm_from_str - parse smack accesses from a text string
257  * @string: a text string that contains a Smack accesses code
258  *
259  * Returns an integer with respective bits set for specified accesses.
260  */
smk_perm_from_str(const char * string)261 static int smk_perm_from_str(const char *string)
262 {
263 	int perm = 0;
264 	const char *cp;
265 
266 	for (cp = string; ; cp++)
267 		switch (*cp) {
268 		case '-':
269 			break;
270 		case 'r':
271 		case 'R':
272 			perm |= MAY_READ;
273 			break;
274 		case 'w':
275 		case 'W':
276 			perm |= MAY_WRITE;
277 			break;
278 		case 'x':
279 		case 'X':
280 			perm |= MAY_EXEC;
281 			break;
282 		case 'a':
283 		case 'A':
284 			perm |= MAY_APPEND;
285 			break;
286 		case 't':
287 		case 'T':
288 			perm |= MAY_TRANSMUTE;
289 			break;
290 		case 'l':
291 		case 'L':
292 			perm |= MAY_LOCK;
293 			break;
294 		case 'b':
295 		case 'B':
296 			perm |= MAY_BRINGUP;
297 			break;
298 		default:
299 			return perm;
300 		}
301 }
302 
303 /**
304  * smk_fill_rule - Fill Smack rule from strings
305  * @subject: subject label string
306  * @object: object label string
307  * @access1: access string
308  * @access2: string with permissions to be removed
309  * @rule: Smack rule
310  * @import: if non-zero, import labels
311  * @len: label length limit
312  *
313  * Returns 0 on success, appropriate error code on failure.
314  */
smk_fill_rule(const char * subject,const char * object,const char * access1,const char * access2,struct smack_parsed_rule * rule,int import,int len)315 static int smk_fill_rule(const char *subject, const char *object,
316 				const char *access1, const char *access2,
317 				struct smack_parsed_rule *rule, int import,
318 				int len)
319 {
320 	const char *cp;
321 	struct smack_known *skp;
322 
323 	if (import) {
324 		rule->smk_subject = smk_import_entry(subject, len);
325 		if (IS_ERR(rule->smk_subject))
326 			return PTR_ERR(rule->smk_subject);
327 
328 		rule->smk_object = smk_import_entry(object, len);
329 		if (IS_ERR(rule->smk_object))
330 			return PTR_ERR(rule->smk_object);
331 	} else {
332 		cp = smk_parse_smack(subject, len);
333 		if (IS_ERR(cp))
334 			return PTR_ERR(cp);
335 		skp = smk_find_entry(cp);
336 		kfree(cp);
337 		if (skp == NULL)
338 			return -ENOENT;
339 		rule->smk_subject = skp;
340 
341 		cp = smk_parse_smack(object, len);
342 		if (IS_ERR(cp))
343 			return PTR_ERR(cp);
344 		skp = smk_find_entry(cp);
345 		kfree(cp);
346 		if (skp == NULL)
347 			return -ENOENT;
348 		rule->smk_object = skp;
349 	}
350 
351 	rule->smk_access1 = smk_perm_from_str(access1);
352 	if (access2)
353 		rule->smk_access2 = smk_perm_from_str(access2);
354 	else
355 		rule->smk_access2 = ~rule->smk_access1;
356 
357 	return 0;
358 }
359 
360 /**
361  * smk_parse_rule - parse Smack rule from load string
362  * @data: string to be parsed whose size is SMK_LOADLEN
363  * @rule: Smack rule
364  * @import: if non-zero, import labels
365  *
366  * Returns 0 on success, -1 on errors.
367  */
smk_parse_rule(const char * data,struct smack_parsed_rule * rule,int import)368 static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule,
369 				int import)
370 {
371 	int rc;
372 
373 	rc = smk_fill_rule(data, data + SMK_LABELLEN,
374 			   data + SMK_LABELLEN + SMK_LABELLEN, NULL, rule,
375 			   import, SMK_LABELLEN);
376 	return rc;
377 }
378 
379 /**
380  * smk_parse_long_rule - parse Smack rule from rule string
381  * @data: string to be parsed, null terminated
382  * @rule: Will be filled with Smack parsed rule
383  * @import: if non-zero, import labels
384  * @tokens: number of substrings expected in data
385  *
386  * Returns number of processed bytes on success, -ERRNO on failure.
387  */
smk_parse_long_rule(char * data,struct smack_parsed_rule * rule,int import,int tokens)388 static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule,
389 				int import, int tokens)
390 {
391 	ssize_t cnt = 0;
392 	char *tok[4];
393 	int rc;
394 	int i;
395 
396 	/*
397 	 * Parsing the rule in-place, filling all white-spaces with '\0'
398 	 */
399 	for (i = 0; i < tokens; ++i) {
400 		while (isspace(data[cnt]))
401 			data[cnt++] = '\0';
402 
403 		if (data[cnt] == '\0')
404 			/* Unexpected end of data */
405 			return -EINVAL;
406 
407 		tok[i] = data + cnt;
408 
409 		while (data[cnt] && !isspace(data[cnt]))
410 			++cnt;
411 	}
412 	while (isspace(data[cnt]))
413 		data[cnt++] = '\0';
414 
415 	while (i < 4)
416 		tok[i++] = NULL;
417 
418 	rc = smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0);
419 	return rc == 0 ? cnt : rc;
420 }
421 
422 #define SMK_FIXED24_FMT	0	/* Fixed 24byte label format */
423 #define SMK_LONG_FMT	1	/* Variable long label format */
424 #define SMK_CHANGE_FMT	2	/* Rule modification format */
425 /**
426  * smk_write_rules_list - write() for any /smack rule file
427  * @file: file pointer, not actually used
428  * @buf: where to get the data from
429  * @count: bytes sent
430  * @ppos: where to start - must be 0
431  * @rule_list: the list of rules to write to
432  * @rule_lock: lock for the rule list
433  * @format: /smack/load or /smack/load2 or /smack/change-rule format.
434  *
435  * Get one smack access rule from above.
436  * The format for SMK_LONG_FMT is:
437  *	"subject<whitespace>object<whitespace>access[<whitespace>...]"
438  * The format for SMK_FIXED24_FMT is exactly:
439  *	"subject                 object                  rwxat"
440  * The format for SMK_CHANGE_FMT is:
441  *	"subject<whitespace>object<whitespace>
442  *	 acc_enable<whitespace>acc_disable[<whitespace>...]"
443  */
smk_write_rules_list(struct file * file,const char __user * buf,size_t count,loff_t * ppos,struct list_head * rule_list,struct mutex * rule_lock,int format)444 static ssize_t smk_write_rules_list(struct file *file, const char __user *buf,
445 					size_t count, loff_t *ppos,
446 					struct list_head *rule_list,
447 					struct mutex *rule_lock, int format)
448 {
449 	struct smack_parsed_rule rule;
450 	char *data;
451 	int rc;
452 	int trunc = 0;
453 	int tokens;
454 	ssize_t cnt = 0;
455 
456 	/*
457 	 * No partial writes.
458 	 * Enough data must be present.
459 	 */
460 	if (*ppos != 0)
461 		return -EINVAL;
462 
463 	if (format == SMK_FIXED24_FMT) {
464 		/*
465 		 * Minor hack for backward compatibility
466 		 */
467 		if (count < SMK_OLOADLEN || count > SMK_LOADLEN)
468 			return -EINVAL;
469 	} else {
470 		if (count >= PAGE_SIZE) {
471 			count = PAGE_SIZE - 1;
472 			trunc = 1;
473 		}
474 	}
475 
476 	data = memdup_user_nul(buf, count);
477 	if (IS_ERR(data))
478 		return PTR_ERR(data);
479 
480 	/*
481 	 * In case of parsing only part of user buf,
482 	 * avoid having partial rule at the data buffer
483 	 */
484 	if (trunc) {
485 		while (count > 0 && (data[count - 1] != '\n'))
486 			--count;
487 		if (count == 0) {
488 			rc = -EINVAL;
489 			goto out;
490 		}
491 	}
492 
493 	data[count] = '\0';
494 	tokens = (format == SMK_CHANGE_FMT ? 4 : 3);
495 	while (cnt < count) {
496 		if (format == SMK_FIXED24_FMT) {
497 			rc = smk_parse_rule(data, &rule, 1);
498 			if (rc < 0)
499 				goto out;
500 			cnt = count;
501 		} else {
502 			rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens);
503 			if (rc < 0)
504 				goto out;
505 			if (rc == 0) {
506 				rc = -EINVAL;
507 				goto out;
508 			}
509 			cnt += rc;
510 		}
511 
512 		if (rule_list == NULL)
513 			rc = smk_set_access(&rule, &rule.smk_subject->smk_rules,
514 				&rule.smk_subject->smk_rules_lock);
515 		else
516 			rc = smk_set_access(&rule, rule_list, rule_lock);
517 
518 		if (rc)
519 			goto out;
520 	}
521 
522 	rc = cnt;
523 out:
524 	kfree(data);
525 	return rc;
526 }
527 
528 /*
529  * Core logic for smackfs seq list operations.
530  */
531 
smk_seq_start(struct seq_file * s,loff_t * pos,struct list_head * head)532 static void *smk_seq_start(struct seq_file *s, loff_t *pos,
533 				struct list_head *head)
534 {
535 	struct list_head *list;
536 	int i = *pos;
537 
538 	rcu_read_lock();
539 	for (list = rcu_dereference(list_next_rcu(head));
540 		list != head;
541 		list = rcu_dereference(list_next_rcu(list))) {
542 		if (i-- == 0)
543 			return list;
544 	}
545 
546 	return NULL;
547 }
548 
smk_seq_next(struct seq_file * s,void * v,loff_t * pos,struct list_head * head)549 static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos,
550 				struct list_head *head)
551 {
552 	struct list_head *list = v;
553 
554 	++*pos;
555 	list = rcu_dereference(list_next_rcu(list));
556 
557 	return (list == head) ? NULL : list;
558 }
559 
smk_seq_stop(struct seq_file * s,void * v)560 static void smk_seq_stop(struct seq_file *s, void *v)
561 {
562 	rcu_read_unlock();
563 }
564 
smk_rule_show(struct seq_file * s,struct smack_rule * srp,int max)565 static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max)
566 {
567 	/*
568 	 * Don't show any rules with label names too long for
569 	 * interface file (/smack/load or /smack/load2)
570 	 * because you should expect to be able to write
571 	 * anything you read back.
572 	 */
573 	if (strlen(srp->smk_subject->smk_known) >= max ||
574 	    strlen(srp->smk_object->smk_known) >= max)
575 		return;
576 
577 	if (srp->smk_access == 0)
578 		return;
579 
580 	seq_printf(s, "%s %s",
581 		   srp->smk_subject->smk_known,
582 		   srp->smk_object->smk_known);
583 
584 	seq_putc(s, ' ');
585 
586 	if (srp->smk_access & MAY_READ)
587 		seq_putc(s, 'r');
588 	if (srp->smk_access & MAY_WRITE)
589 		seq_putc(s, 'w');
590 	if (srp->smk_access & MAY_EXEC)
591 		seq_putc(s, 'x');
592 	if (srp->smk_access & MAY_APPEND)
593 		seq_putc(s, 'a');
594 	if (srp->smk_access & MAY_TRANSMUTE)
595 		seq_putc(s, 't');
596 	if (srp->smk_access & MAY_LOCK)
597 		seq_putc(s, 'l');
598 	if (srp->smk_access & MAY_BRINGUP)
599 		seq_putc(s, 'b');
600 
601 	seq_putc(s, '\n');
602 }
603 
604 /*
605  * Seq_file read operations for /smack/load
606  */
607 
load2_seq_start(struct seq_file * s,loff_t * pos)608 static void *load2_seq_start(struct seq_file *s, loff_t *pos)
609 {
610 	return smk_seq_start(s, pos, &smack_known_list);
611 }
612 
load2_seq_next(struct seq_file * s,void * v,loff_t * pos)613 static void *load2_seq_next(struct seq_file *s, void *v, loff_t *pos)
614 {
615 	return smk_seq_next(s, v, pos, &smack_known_list);
616 }
617 
load_seq_show(struct seq_file * s,void * v)618 static int load_seq_show(struct seq_file *s, void *v)
619 {
620 	struct list_head *list = v;
621 	struct smack_rule *srp;
622 	struct smack_known *skp =
623 		list_entry_rcu(list, struct smack_known, list);
624 
625 	list_for_each_entry_rcu(srp, &skp->smk_rules, list)
626 		smk_rule_show(s, srp, SMK_LABELLEN);
627 
628 	return 0;
629 }
630 
631 static const struct seq_operations load_seq_ops = {
632 	.start = load2_seq_start,
633 	.next  = load2_seq_next,
634 	.show  = load_seq_show,
635 	.stop  = smk_seq_stop,
636 };
637 
638 /**
639  * smk_open_load - open() for /smack/load
640  * @inode: inode structure representing file
641  * @file: "load" file pointer
642  *
643  * For reading, use load_seq_* seq_file reading operations.
644  */
smk_open_load(struct inode * inode,struct file * file)645 static int smk_open_load(struct inode *inode, struct file *file)
646 {
647 	return seq_open(file, &load_seq_ops);
648 }
649 
650 /**
651  * smk_write_load - write() for /smack/load
652  * @file: file pointer, not actually used
653  * @buf: where to get the data from
654  * @count: bytes sent
655  * @ppos: where to start - must be 0
656  *
657  */
smk_write_load(struct file * file,const char __user * buf,size_t count,loff_t * ppos)658 static ssize_t smk_write_load(struct file *file, const char __user *buf,
659 			      size_t count, loff_t *ppos)
660 {
661 	/*
662 	 * Must have privilege.
663 	 * No partial writes.
664 	 * Enough data must be present.
665 	 */
666 	if (!smack_privileged(CAP_MAC_ADMIN))
667 		return -EPERM;
668 
669 	return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
670 				    SMK_FIXED24_FMT);
671 }
672 
673 static const struct file_operations smk_load_ops = {
674 	.open           = smk_open_load,
675 	.read		= seq_read,
676 	.llseek         = seq_lseek,
677 	.write		= smk_write_load,
678 	.release        = seq_release,
679 };
680 
681 /**
682  * smk_cipso_doi - initialize the CIPSO domain
683  */
smk_cipso_doi(void)684 static void smk_cipso_doi(void)
685 {
686 	int rc;
687 	struct cipso_v4_doi *doip;
688 	struct netlbl_audit nai;
689 
690 	smk_netlabel_audit_set(&nai);
691 
692 	rc = netlbl_cfg_map_del(NULL, PF_INET, NULL, NULL, &nai);
693 	if (rc != 0)
694 		printk(KERN_WARNING "%s:%d remove rc = %d\n",
695 		       __func__, __LINE__, rc);
696 
697 	doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL);
698 	doip->map.std = NULL;
699 	doip->doi = smk_cipso_doi_value;
700 	doip->type = CIPSO_V4_MAP_PASS;
701 	doip->tags[0] = CIPSO_V4_TAG_RBITMAP;
702 	for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++)
703 		doip->tags[rc] = CIPSO_V4_TAG_INVALID;
704 
705 	rc = netlbl_cfg_cipsov4_add(doip, &nai);
706 	if (rc != 0) {
707 		printk(KERN_WARNING "%s:%d cipso add rc = %d\n",
708 		       __func__, __LINE__, rc);
709 		kfree(doip);
710 		return;
711 	}
712 	rc = netlbl_cfg_cipsov4_map_add(doip->doi, NULL, NULL, NULL, &nai);
713 	if (rc != 0) {
714 		printk(KERN_WARNING "%s:%d map add rc = %d\n",
715 		       __func__, __LINE__, rc);
716 		netlbl_cfg_cipsov4_del(doip->doi, &nai);
717 		return;
718 	}
719 }
720 
721 /**
722  * smk_unlbl_ambient - initialize the unlabeled domain
723  * @oldambient: previous domain string
724  */
smk_unlbl_ambient(char * oldambient)725 static void smk_unlbl_ambient(char *oldambient)
726 {
727 	int rc;
728 	struct netlbl_audit nai;
729 
730 	smk_netlabel_audit_set(&nai);
731 
732 	if (oldambient != NULL) {
733 		rc = netlbl_cfg_map_del(oldambient, PF_INET, NULL, NULL, &nai);
734 		if (rc != 0)
735 			printk(KERN_WARNING "%s:%d remove rc = %d\n",
736 			       __func__, __LINE__, rc);
737 	}
738 	if (smack_net_ambient == NULL)
739 		smack_net_ambient = &smack_known_floor;
740 
741 	rc = netlbl_cfg_unlbl_map_add(smack_net_ambient->smk_known, PF_INET,
742 				      NULL, NULL, &nai);
743 	if (rc != 0)
744 		printk(KERN_WARNING "%s:%d add rc = %d\n",
745 		       __func__, __LINE__, rc);
746 }
747 
748 /*
749  * Seq_file read operations for /smack/cipso
750  */
751 
cipso_seq_start(struct seq_file * s,loff_t * pos)752 static void *cipso_seq_start(struct seq_file *s, loff_t *pos)
753 {
754 	return smk_seq_start(s, pos, &smack_known_list);
755 }
756 
cipso_seq_next(struct seq_file * s,void * v,loff_t * pos)757 static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos)
758 {
759 	return smk_seq_next(s, v, pos, &smack_known_list);
760 }
761 
762 /*
763  * Print cipso labels in format:
764  * label level[/cat[,cat]]
765  */
cipso_seq_show(struct seq_file * s,void * v)766 static int cipso_seq_show(struct seq_file *s, void *v)
767 {
768 	struct list_head  *list = v;
769 	struct smack_known *skp =
770 		list_entry_rcu(list, struct smack_known, list);
771 	struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
772 	char sep = '/';
773 	int i;
774 
775 	/*
776 	 * Don't show a label that could not have been set using
777 	 * /smack/cipso. This is in support of the notion that
778 	 * anything read from /smack/cipso ought to be writeable
779 	 * to /smack/cipso.
780 	 *
781 	 * /smack/cipso2 should be used instead.
782 	 */
783 	if (strlen(skp->smk_known) >= SMK_LABELLEN)
784 		return 0;
785 
786 	seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
787 
788 	for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
789 	     i = netlbl_catmap_walk(cmp, i + 1)) {
790 		seq_printf(s, "%c%d", sep, i);
791 		sep = ',';
792 	}
793 
794 	seq_putc(s, '\n');
795 
796 	return 0;
797 }
798 
799 static const struct seq_operations cipso_seq_ops = {
800 	.start = cipso_seq_start,
801 	.next  = cipso_seq_next,
802 	.show  = cipso_seq_show,
803 	.stop  = smk_seq_stop,
804 };
805 
806 /**
807  * smk_open_cipso - open() for /smack/cipso
808  * @inode: inode structure representing file
809  * @file: "cipso" file pointer
810  *
811  * Connect our cipso_seq_* operations with /smack/cipso
812  * file_operations
813  */
smk_open_cipso(struct inode * inode,struct file * file)814 static int smk_open_cipso(struct inode *inode, struct file *file)
815 {
816 	return seq_open(file, &cipso_seq_ops);
817 }
818 
819 /**
820  * smk_set_cipso - do the work for write() for cipso and cipso2
821  * @file: file pointer, not actually used
822  * @buf: where to get the data from
823  * @count: bytes sent
824  * @ppos: where to start
825  * @format: /smack/cipso or /smack/cipso2
826  *
827  * Accepts only one cipso rule per write call.
828  * Returns number of bytes written or error code, as appropriate
829  */
smk_set_cipso(struct file * file,const char __user * buf,size_t count,loff_t * ppos,int format)830 static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
831 				size_t count, loff_t *ppos, int format)
832 {
833 	struct netlbl_lsm_catmap *old_cat, *new_cat = NULL;
834 	struct smack_known *skp;
835 	struct netlbl_lsm_secattr ncats;
836 	char mapcatset[SMK_CIPSOLEN];
837 	int maplevel;
838 	unsigned int cat;
839 	int catlen;
840 	ssize_t rc = -EINVAL;
841 	char *data = NULL;
842 	char *rule;
843 	int ret;
844 	int i;
845 
846 	/*
847 	 * Must have privilege.
848 	 * No partial writes.
849 	 * Enough data must be present.
850 	 */
851 	if (!smack_privileged(CAP_MAC_ADMIN))
852 		return -EPERM;
853 	if (*ppos != 0)
854 		return -EINVAL;
855 	if (format == SMK_FIXED24_FMT &&
856 	    (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX))
857 		return -EINVAL;
858 	if (count > PAGE_SIZE)
859 		return -EINVAL;
860 
861 	data = memdup_user_nul(buf, count);
862 	if (IS_ERR(data))
863 		return PTR_ERR(data);
864 
865 	rule = data;
866 	/*
867 	 * Only allow one writer at a time. Writes should be
868 	 * quite rare and small in any case.
869 	 */
870 	mutex_lock(&smack_cipso_lock);
871 
872 	skp = smk_import_entry(rule, 0);
873 	if (IS_ERR(skp)) {
874 		rc = PTR_ERR(skp);
875 		goto out;
876 	}
877 
878 	if (format == SMK_FIXED24_FMT)
879 		rule += SMK_LABELLEN;
880 	else
881 		rule += strlen(skp->smk_known) + 1;
882 
883 	if (rule > data + count) {
884 		rc = -EOVERFLOW;
885 		goto out;
886 	}
887 
888 	ret = sscanf(rule, "%d", &maplevel);
889 	if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL)
890 		goto out;
891 
892 	rule += SMK_DIGITLEN;
893 	if (rule > data + count) {
894 		rc = -EOVERFLOW;
895 		goto out;
896 	}
897 
898 	ret = sscanf(rule, "%d", &catlen);
899 	if (ret != 1 || catlen < 0 || catlen > SMACK_CIPSO_MAXCATNUM)
900 		goto out;
901 
902 	if (format == SMK_FIXED24_FMT &&
903 	    count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN))
904 		goto out;
905 
906 	memset(mapcatset, 0, sizeof(mapcatset));
907 
908 	for (i = 0; i < catlen; i++) {
909 		rule += SMK_DIGITLEN;
910 		if (rule > data + count) {
911 			rc = -EOVERFLOW;
912 			goto out;
913 		}
914 		ret = sscanf(rule, "%u", &cat);
915 		if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM)
916 			goto out;
917 
918 		smack_catset_bit(cat, mapcatset);
919 	}
920 	ncats.flags = 0;
921 	if (catlen == 0) {
922 		ncats.attr.mls.cat = NULL;
923 		ncats.attr.mls.lvl = maplevel;
924 		new_cat = netlbl_catmap_alloc(GFP_ATOMIC);
925 		if (new_cat)
926 			new_cat->next = ncats.attr.mls.cat;
927 		ncats.attr.mls.cat = new_cat;
928 		skp->smk_netlabel.flags &= ~(1U << 3);
929 		rc = 0;
930 	} else {
931 		rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
932 	}
933 	if (rc >= 0) {
934 		old_cat = skp->smk_netlabel.attr.mls.cat;
935 		skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat;
936 		skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl;
937 		synchronize_rcu();
938 		netlbl_catmap_free(old_cat);
939 		rc = count;
940 		/*
941 		 * This mapping may have been cached, so clear the cache.
942 		 */
943 		netlbl_cache_invalidate();
944 	}
945 
946 out:
947 	mutex_unlock(&smack_cipso_lock);
948 	kfree(data);
949 	return rc;
950 }
951 
952 /**
953  * smk_write_cipso - write() for /smack/cipso
954  * @file: file pointer, not actually used
955  * @buf: where to get the data from
956  * @count: bytes sent
957  * @ppos: where to start
958  *
959  * Accepts only one cipso rule per write call.
960  * Returns number of bytes written or error code, as appropriate
961  */
smk_write_cipso(struct file * file,const char __user * buf,size_t count,loff_t * ppos)962 static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
963 			       size_t count, loff_t *ppos)
964 {
965 	return smk_set_cipso(file, buf, count, ppos, SMK_FIXED24_FMT);
966 }
967 
968 static const struct file_operations smk_cipso_ops = {
969 	.open           = smk_open_cipso,
970 	.read		= seq_read,
971 	.llseek         = seq_lseek,
972 	.write		= smk_write_cipso,
973 	.release        = seq_release,
974 };
975 
976 /*
977  * Seq_file read operations for /smack/cipso2
978  */
979 
980 /*
981  * Print cipso labels in format:
982  * label level[/cat[,cat]]
983  */
cipso2_seq_show(struct seq_file * s,void * v)984 static int cipso2_seq_show(struct seq_file *s, void *v)
985 {
986 	struct list_head  *list = v;
987 	struct smack_known *skp =
988 		list_entry_rcu(list, struct smack_known, list);
989 	struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
990 	char sep = '/';
991 	int i;
992 
993 	seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
994 
995 	for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
996 	     i = netlbl_catmap_walk(cmp, i + 1)) {
997 		seq_printf(s, "%c%d", sep, i);
998 		sep = ',';
999 	}
1000 
1001 	seq_putc(s, '\n');
1002 
1003 	return 0;
1004 }
1005 
1006 static const struct seq_operations cipso2_seq_ops = {
1007 	.start = cipso_seq_start,
1008 	.next  = cipso_seq_next,
1009 	.show  = cipso2_seq_show,
1010 	.stop  = smk_seq_stop,
1011 };
1012 
1013 /**
1014  * smk_open_cipso2 - open() for /smack/cipso2
1015  * @inode: inode structure representing file
1016  * @file: "cipso2" file pointer
1017  *
1018  * Connect our cipso_seq_* operations with /smack/cipso2
1019  * file_operations
1020  */
smk_open_cipso2(struct inode * inode,struct file * file)1021 static int smk_open_cipso2(struct inode *inode, struct file *file)
1022 {
1023 	return seq_open(file, &cipso2_seq_ops);
1024 }
1025 
1026 /**
1027  * smk_write_cipso2 - write() for /smack/cipso2
1028  * @file: file pointer, not actually used
1029  * @buf: where to get the data from
1030  * @count: bytes sent
1031  * @ppos: where to start
1032  *
1033  * Accepts only one cipso rule per write call.
1034  * Returns number of bytes written or error code, as appropriate
1035  */
smk_write_cipso2(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1036 static ssize_t smk_write_cipso2(struct file *file, const char __user *buf,
1037 			      size_t count, loff_t *ppos)
1038 {
1039 	return smk_set_cipso(file, buf, count, ppos, SMK_LONG_FMT);
1040 }
1041 
1042 static const struct file_operations smk_cipso2_ops = {
1043 	.open           = smk_open_cipso2,
1044 	.read		= seq_read,
1045 	.llseek         = seq_lseek,
1046 	.write		= smk_write_cipso2,
1047 	.release        = seq_release,
1048 };
1049 
1050 /*
1051  * Seq_file read operations for /smack/netlabel
1052  */
1053 
net4addr_seq_start(struct seq_file * s,loff_t * pos)1054 static void *net4addr_seq_start(struct seq_file *s, loff_t *pos)
1055 {
1056 	return smk_seq_start(s, pos, &smk_net4addr_list);
1057 }
1058 
net4addr_seq_next(struct seq_file * s,void * v,loff_t * pos)1059 static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
1060 {
1061 	return smk_seq_next(s, v, pos, &smk_net4addr_list);
1062 }
1063 
1064 /*
1065  * Print host/label pairs
1066  */
net4addr_seq_show(struct seq_file * s,void * v)1067 static int net4addr_seq_show(struct seq_file *s, void *v)
1068 {
1069 	struct list_head *list = v;
1070 	struct smk_net4addr *skp =
1071 			list_entry_rcu(list, struct smk_net4addr, list);
1072 	char *kp = SMACK_CIPSO_OPTION;
1073 
1074 	if (skp->smk_label != NULL)
1075 		kp = skp->smk_label->smk_known;
1076 	seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr,
1077 			skp->smk_masks, kp);
1078 
1079 	return 0;
1080 }
1081 
1082 static const struct seq_operations net4addr_seq_ops = {
1083 	.start = net4addr_seq_start,
1084 	.next  = net4addr_seq_next,
1085 	.show  = net4addr_seq_show,
1086 	.stop  = smk_seq_stop,
1087 };
1088 
1089 /**
1090  * smk_open_net4addr - open() for /smack/netlabel
1091  * @inode: inode structure representing file
1092  * @file: "netlabel" file pointer
1093  *
1094  * Connect our net4addr_seq_* operations with /smack/netlabel
1095  * file_operations
1096  */
smk_open_net4addr(struct inode * inode,struct file * file)1097 static int smk_open_net4addr(struct inode *inode, struct file *file)
1098 {
1099 	return seq_open(file, &net4addr_seq_ops);
1100 }
1101 
1102 /**
1103  * smk_net4addr_insert
1104  * @new : netlabel to insert
1105  *
1106  * This helper insert netlabel in the smack_net4addrs list
1107  * sorted by netmask length (longest to smallest)
1108  * locked by &smk_net4addr_lock in smk_write_net4addr
1109  *
1110  */
smk_net4addr_insert(struct smk_net4addr * new)1111 static void smk_net4addr_insert(struct smk_net4addr *new)
1112 {
1113 	struct smk_net4addr *m;
1114 	struct smk_net4addr *m_next;
1115 
1116 	if (list_empty(&smk_net4addr_list)) {
1117 		list_add_rcu(&new->list, &smk_net4addr_list);
1118 		return;
1119 	}
1120 
1121 	m = list_entry_rcu(smk_net4addr_list.next,
1122 			   struct smk_net4addr, list);
1123 
1124 	/* the comparison '>' is a bit hacky, but works */
1125 	if (new->smk_masks > m->smk_masks) {
1126 		list_add_rcu(&new->list, &smk_net4addr_list);
1127 		return;
1128 	}
1129 
1130 	list_for_each_entry_rcu(m, &smk_net4addr_list, list) {
1131 		if (list_is_last(&m->list, &smk_net4addr_list)) {
1132 			list_add_rcu(&new->list, &m->list);
1133 			return;
1134 		}
1135 		m_next = list_entry_rcu(m->list.next,
1136 					struct smk_net4addr, list);
1137 		if (new->smk_masks > m_next->smk_masks) {
1138 			list_add_rcu(&new->list, &m->list);
1139 			return;
1140 		}
1141 	}
1142 }
1143 
1144 
1145 /**
1146  * smk_write_net4addr - write() for /smack/netlabel
1147  * @file: file pointer, not actually used
1148  * @buf: where to get the data from
1149  * @count: bytes sent
1150  * @ppos: where to start
1151  *
1152  * Accepts only one net4addr per write call.
1153  * Returns number of bytes written or error code, as appropriate
1154  */
smk_write_net4addr(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1155 static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
1156 				size_t count, loff_t *ppos)
1157 {
1158 	struct smk_net4addr *snp;
1159 	struct sockaddr_in newname;
1160 	char *smack;
1161 	struct smack_known *skp = NULL;
1162 	char *data;
1163 	char *host = (char *)&newname.sin_addr.s_addr;
1164 	int rc;
1165 	struct netlbl_audit audit_info;
1166 	struct in_addr mask;
1167 	unsigned int m;
1168 	unsigned int masks;
1169 	int found;
1170 	u32 mask_bits = (1<<31);
1171 	__be32 nsa;
1172 	u32 temp_mask;
1173 
1174 	/*
1175 	 * Must have privilege.
1176 	 * No partial writes.
1177 	 * Enough data must be present.
1178 	 * "<addr/mask, as a.b.c.d/e><space><label>"
1179 	 * "<addr, as a.b.c.d><space><label>"
1180 	 */
1181 	if (!smack_privileged(CAP_MAC_ADMIN))
1182 		return -EPERM;
1183 	if (*ppos != 0)
1184 		return -EINVAL;
1185 	if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
1186 		return -EINVAL;
1187 
1188 	data = memdup_user_nul(buf, count);
1189 	if (IS_ERR(data))
1190 		return PTR_ERR(data);
1191 
1192 	smack = kzalloc(count + 1, GFP_KERNEL);
1193 	if (smack == NULL) {
1194 		rc = -ENOMEM;
1195 		goto free_data_out;
1196 	}
1197 
1198 	rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s",
1199 		&host[0], &host[1], &host[2], &host[3], &masks, smack);
1200 	if (rc != 6) {
1201 		rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s",
1202 			&host[0], &host[1], &host[2], &host[3], smack);
1203 		if (rc != 5) {
1204 			rc = -EINVAL;
1205 			goto free_out;
1206 		}
1207 		masks = 32;
1208 	}
1209 	if (masks > BEBITS) {
1210 		rc = -EINVAL;
1211 		goto free_out;
1212 	}
1213 
1214 	/*
1215 	 * If smack begins with '-', it is an option, don't import it
1216 	 */
1217 	if (smack[0] != '-') {
1218 		skp = smk_import_entry(smack, 0);
1219 		if (IS_ERR(skp)) {
1220 			rc = PTR_ERR(skp);
1221 			goto free_out;
1222 		}
1223 	} else {
1224 		/*
1225 		 * Only the -CIPSO option is supported for IPv4
1226 		 */
1227 		if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) {
1228 			rc = -EINVAL;
1229 			goto free_out;
1230 		}
1231 	}
1232 
1233 	for (m = masks, temp_mask = 0; m > 0; m--) {
1234 		temp_mask |= mask_bits;
1235 		mask_bits >>= 1;
1236 	}
1237 	mask.s_addr = cpu_to_be32(temp_mask);
1238 
1239 	newname.sin_addr.s_addr &= mask.s_addr;
1240 	/*
1241 	 * Only allow one writer at a time. Writes should be
1242 	 * quite rare and small in any case.
1243 	 */
1244 	mutex_lock(&smk_net4addr_lock);
1245 
1246 	nsa = newname.sin_addr.s_addr;
1247 	/* try to find if the prefix is already in the list */
1248 	found = 0;
1249 	list_for_each_entry_rcu(snp, &smk_net4addr_list, list) {
1250 		if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) {
1251 			found = 1;
1252 			break;
1253 		}
1254 	}
1255 	smk_netlabel_audit_set(&audit_info);
1256 
1257 	if (found == 0) {
1258 		snp = kzalloc(sizeof(*snp), GFP_KERNEL);
1259 		if (snp == NULL)
1260 			rc = -ENOMEM;
1261 		else {
1262 			rc = 0;
1263 			snp->smk_host.s_addr = newname.sin_addr.s_addr;
1264 			snp->smk_mask.s_addr = mask.s_addr;
1265 			snp->smk_label = skp;
1266 			snp->smk_masks = masks;
1267 			smk_net4addr_insert(snp);
1268 		}
1269 	} else {
1270 		/*
1271 		 * Delete the unlabeled entry, only if the previous label
1272 		 * wasn't the special CIPSO option
1273 		 */
1274 		if (snp->smk_label != NULL)
1275 			rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
1276 					&snp->smk_host, &snp->smk_mask,
1277 					PF_INET, &audit_info);
1278 		else
1279 			rc = 0;
1280 		snp->smk_label = skp;
1281 	}
1282 
1283 	/*
1284 	 * Now tell netlabel about the single label nature of
1285 	 * this host so that incoming packets get labeled.
1286 	 * but only if we didn't get the special CIPSO option
1287 	 */
1288 	if (rc == 0 && skp != NULL)
1289 		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
1290 			&snp->smk_host, &snp->smk_mask, PF_INET,
1291 			snp->smk_label->smk_secid, &audit_info);
1292 
1293 	if (rc == 0)
1294 		rc = count;
1295 
1296 	mutex_unlock(&smk_net4addr_lock);
1297 
1298 free_out:
1299 	kfree(smack);
1300 free_data_out:
1301 	kfree(data);
1302 
1303 	return rc;
1304 }
1305 
1306 static const struct file_operations smk_net4addr_ops = {
1307 	.open           = smk_open_net4addr,
1308 	.read		= seq_read,
1309 	.llseek         = seq_lseek,
1310 	.write		= smk_write_net4addr,
1311 	.release        = seq_release,
1312 };
1313 
1314 #if IS_ENABLED(CONFIG_IPV6)
1315 /*
1316  * Seq_file read operations for /smack/netlabel6
1317  */
1318 
net6addr_seq_start(struct seq_file * s,loff_t * pos)1319 static void *net6addr_seq_start(struct seq_file *s, loff_t *pos)
1320 {
1321 	return smk_seq_start(s, pos, &smk_net6addr_list);
1322 }
1323 
net6addr_seq_next(struct seq_file * s,void * v,loff_t * pos)1324 static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
1325 {
1326 	return smk_seq_next(s, v, pos, &smk_net6addr_list);
1327 }
1328 
1329 /*
1330  * Print host/label pairs
1331  */
net6addr_seq_show(struct seq_file * s,void * v)1332 static int net6addr_seq_show(struct seq_file *s, void *v)
1333 {
1334 	struct list_head *list = v;
1335 	struct smk_net6addr *skp =
1336 			 list_entry(list, struct smk_net6addr, list);
1337 
1338 	if (skp->smk_label != NULL)
1339 		seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks,
1340 				skp->smk_label->smk_known);
1341 
1342 	return 0;
1343 }
1344 
1345 static const struct seq_operations net6addr_seq_ops = {
1346 	.start = net6addr_seq_start,
1347 	.next  = net6addr_seq_next,
1348 	.show  = net6addr_seq_show,
1349 	.stop  = smk_seq_stop,
1350 };
1351 
1352 /**
1353  * smk_open_net6addr - open() for /smack/netlabel
1354  * @inode: inode structure representing file
1355  * @file: "netlabel" file pointer
1356  *
1357  * Connect our net6addr_seq_* operations with /smack/netlabel
1358  * file_operations
1359  */
smk_open_net6addr(struct inode * inode,struct file * file)1360 static int smk_open_net6addr(struct inode *inode, struct file *file)
1361 {
1362 	return seq_open(file, &net6addr_seq_ops);
1363 }
1364 
1365 /**
1366  * smk_net6addr_insert
1367  * @new : entry to insert
1368  *
1369  * This inserts an entry in the smack_net6addrs list
1370  * sorted by netmask length (longest to smallest)
1371  * locked by &smk_net6addr_lock in smk_write_net6addr
1372  *
1373  */
smk_net6addr_insert(struct smk_net6addr * new)1374 static void smk_net6addr_insert(struct smk_net6addr *new)
1375 {
1376 	struct smk_net6addr *m_next;
1377 	struct smk_net6addr *m;
1378 
1379 	if (list_empty(&smk_net6addr_list)) {
1380 		list_add_rcu(&new->list, &smk_net6addr_list);
1381 		return;
1382 	}
1383 
1384 	m = list_entry_rcu(smk_net6addr_list.next,
1385 			   struct smk_net6addr, list);
1386 
1387 	if (new->smk_masks > m->smk_masks) {
1388 		list_add_rcu(&new->list, &smk_net6addr_list);
1389 		return;
1390 	}
1391 
1392 	list_for_each_entry_rcu(m, &smk_net6addr_list, list) {
1393 		if (list_is_last(&m->list, &smk_net6addr_list)) {
1394 			list_add_rcu(&new->list, &m->list);
1395 			return;
1396 		}
1397 		m_next = list_entry_rcu(m->list.next,
1398 					struct smk_net6addr, list);
1399 		if (new->smk_masks > m_next->smk_masks) {
1400 			list_add_rcu(&new->list, &m->list);
1401 			return;
1402 		}
1403 	}
1404 }
1405 
1406 
1407 /**
1408  * smk_write_net6addr - write() for /smack/netlabel
1409  * @file: file pointer, not actually used
1410  * @buf: where to get the data from
1411  * @count: bytes sent
1412  * @ppos: where to start
1413  *
1414  * Accepts only one net6addr per write call.
1415  * Returns number of bytes written or error code, as appropriate
1416  */
smk_write_net6addr(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1417 static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
1418 				size_t count, loff_t *ppos)
1419 {
1420 	struct smk_net6addr *snp;
1421 	struct in6_addr newname;
1422 	struct in6_addr fullmask;
1423 	struct smack_known *skp = NULL;
1424 	char *smack;
1425 	char *data;
1426 	int rc = 0;
1427 	int found = 0;
1428 	int i;
1429 	unsigned int scanned[8];
1430 	unsigned int m;
1431 	unsigned int mask = 128;
1432 
1433 	/*
1434 	 * Must have privilege.
1435 	 * No partial writes.
1436 	 * Enough data must be present.
1437 	 * "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>"
1438 	 * "<addr, as a:b:c:d:e:f:g:h><space><label>"
1439 	 */
1440 	if (!smack_privileged(CAP_MAC_ADMIN))
1441 		return -EPERM;
1442 	if (*ppos != 0)
1443 		return -EINVAL;
1444 	if (count < SMK_NETLBLADDRMIN || count > PAGE_SIZE - 1)
1445 		return -EINVAL;
1446 
1447 	data = memdup_user_nul(buf, count);
1448 	if (IS_ERR(data))
1449 		return PTR_ERR(data);
1450 
1451 	smack = kzalloc(count + 1, GFP_KERNEL);
1452 	if (smack == NULL) {
1453 		rc = -ENOMEM;
1454 		goto free_data_out;
1455 	}
1456 
1457 	i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s",
1458 			&scanned[0], &scanned[1], &scanned[2], &scanned[3],
1459 			&scanned[4], &scanned[5], &scanned[6], &scanned[7],
1460 			&mask, smack);
1461 	if (i != 10) {
1462 		i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s",
1463 				&scanned[0], &scanned[1], &scanned[2],
1464 				&scanned[3], &scanned[4], &scanned[5],
1465 				&scanned[6], &scanned[7], smack);
1466 		if (i != 9) {
1467 			rc = -EINVAL;
1468 			goto free_out;
1469 		}
1470 	}
1471 	if (mask > 128) {
1472 		rc = -EINVAL;
1473 		goto free_out;
1474 	}
1475 	for (i = 0; i < 8; i++) {
1476 		if (scanned[i] > 0xffff) {
1477 			rc = -EINVAL;
1478 			goto free_out;
1479 		}
1480 		newname.s6_addr16[i] = htons(scanned[i]);
1481 	}
1482 
1483 	/*
1484 	 * If smack begins with '-', it is an option, don't import it
1485 	 */
1486 	if (smack[0] != '-') {
1487 		skp = smk_import_entry(smack, 0);
1488 		if (IS_ERR(skp)) {
1489 			rc = PTR_ERR(skp);
1490 			goto free_out;
1491 		}
1492 	} else {
1493 		/*
1494 		 * Only -DELETE is supported for IPv6
1495 		 */
1496 		if (strcmp(smack, SMACK_DELETE_OPTION) != 0) {
1497 			rc = -EINVAL;
1498 			goto free_out;
1499 		}
1500 	}
1501 
1502 	for (i = 0, m = mask; i < 8; i++) {
1503 		if (m >= 16) {
1504 			fullmask.s6_addr16[i] = 0xffff;
1505 			m -= 16;
1506 		} else if (m > 0) {
1507 			fullmask.s6_addr16[i] = (1 << m) - 1;
1508 			m = 0;
1509 		} else
1510 			fullmask.s6_addr16[i] = 0;
1511 		newname.s6_addr16[i] &= fullmask.s6_addr16[i];
1512 	}
1513 
1514 	/*
1515 	 * Only allow one writer at a time. Writes should be
1516 	 * quite rare and small in any case.
1517 	 */
1518 	mutex_lock(&smk_net6addr_lock);
1519 	/*
1520 	 * Try to find the prefix in the list
1521 	 */
1522 	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
1523 		if (mask != snp->smk_masks)
1524 			continue;
1525 		for (found = 1, i = 0; i < 8; i++) {
1526 			if (newname.s6_addr16[i] !=
1527 			    snp->smk_host.s6_addr16[i]) {
1528 				found = 0;
1529 				break;
1530 			}
1531 		}
1532 		if (found == 1)
1533 			break;
1534 	}
1535 	if (found == 0) {
1536 		snp = kzalloc(sizeof(*snp), GFP_KERNEL);
1537 		if (snp == NULL)
1538 			rc = -ENOMEM;
1539 		else {
1540 			snp->smk_host = newname;
1541 			snp->smk_mask = fullmask;
1542 			snp->smk_masks = mask;
1543 			snp->smk_label = skp;
1544 			smk_net6addr_insert(snp);
1545 		}
1546 	} else {
1547 		snp->smk_label = skp;
1548 	}
1549 
1550 	if (rc == 0)
1551 		rc = count;
1552 
1553 	mutex_unlock(&smk_net6addr_lock);
1554 
1555 free_out:
1556 	kfree(smack);
1557 free_data_out:
1558 	kfree(data);
1559 
1560 	return rc;
1561 }
1562 
1563 static const struct file_operations smk_net6addr_ops = {
1564 	.open           = smk_open_net6addr,
1565 	.read		= seq_read,
1566 	.llseek         = seq_lseek,
1567 	.write		= smk_write_net6addr,
1568 	.release        = seq_release,
1569 };
1570 #endif /* CONFIG_IPV6 */
1571 
1572 /**
1573  * smk_read_doi - read() for /smack/doi
1574  * @filp: file pointer, not actually used
1575  * @buf: where to put the result
1576  * @count: maximum to send along
1577  * @ppos: where to start
1578  *
1579  * Returns number of bytes read or error code, as appropriate
1580  */
smk_read_doi(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1581 static ssize_t smk_read_doi(struct file *filp, char __user *buf,
1582 			    size_t count, loff_t *ppos)
1583 {
1584 	char temp[80];
1585 	ssize_t rc;
1586 
1587 	if (*ppos != 0)
1588 		return 0;
1589 
1590 	sprintf(temp, "%d", smk_cipso_doi_value);
1591 	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
1592 
1593 	return rc;
1594 }
1595 
1596 /**
1597  * smk_write_doi - write() for /smack/doi
1598  * @file: file pointer, not actually used
1599  * @buf: where to get the data from
1600  * @count: bytes sent
1601  * @ppos: where to start
1602  *
1603  * Returns number of bytes written or error code, as appropriate
1604  */
smk_write_doi(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1605 static ssize_t smk_write_doi(struct file *file, const char __user *buf,
1606 			     size_t count, loff_t *ppos)
1607 {
1608 	char temp[80];
1609 	int i;
1610 
1611 	if (!smack_privileged(CAP_MAC_ADMIN))
1612 		return -EPERM;
1613 
1614 	if (count >= sizeof(temp) || count == 0)
1615 		return -EINVAL;
1616 
1617 	if (copy_from_user(temp, buf, count) != 0)
1618 		return -EFAULT;
1619 
1620 	temp[count] = '\0';
1621 
1622 	if (sscanf(temp, "%d", &i) != 1)
1623 		return -EINVAL;
1624 
1625 	smk_cipso_doi_value = i;
1626 
1627 	smk_cipso_doi();
1628 
1629 	return count;
1630 }
1631 
1632 static const struct file_operations smk_doi_ops = {
1633 	.read		= smk_read_doi,
1634 	.write		= smk_write_doi,
1635 	.llseek		= default_llseek,
1636 };
1637 
1638 /**
1639  * smk_read_direct - read() for /smack/direct
1640  * @filp: file pointer, not actually used
1641  * @buf: where to put the result
1642  * @count: maximum to send along
1643  * @ppos: where to start
1644  *
1645  * Returns number of bytes read or error code, as appropriate
1646  */
smk_read_direct(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1647 static ssize_t smk_read_direct(struct file *filp, char __user *buf,
1648 			       size_t count, loff_t *ppos)
1649 {
1650 	char temp[80];
1651 	ssize_t rc;
1652 
1653 	if (*ppos != 0)
1654 		return 0;
1655 
1656 	sprintf(temp, "%d", smack_cipso_direct);
1657 	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
1658 
1659 	return rc;
1660 }
1661 
1662 /**
1663  * smk_write_direct - write() for /smack/direct
1664  * @file: file pointer, not actually used
1665  * @buf: where to get the data from
1666  * @count: bytes sent
1667  * @ppos: where to start
1668  *
1669  * Returns number of bytes written or error code, as appropriate
1670  */
smk_write_direct(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1671 static ssize_t smk_write_direct(struct file *file, const char __user *buf,
1672 				size_t count, loff_t *ppos)
1673 {
1674 	struct smack_known *skp;
1675 	char temp[80];
1676 	int i;
1677 
1678 	if (!smack_privileged(CAP_MAC_ADMIN))
1679 		return -EPERM;
1680 
1681 	if (count >= sizeof(temp) || count == 0)
1682 		return -EINVAL;
1683 
1684 	if (copy_from_user(temp, buf, count) != 0)
1685 		return -EFAULT;
1686 
1687 	temp[count] = '\0';
1688 
1689 	if (sscanf(temp, "%d", &i) != 1)
1690 		return -EINVAL;
1691 
1692 	/*
1693 	 * Don't do anything if the value hasn't actually changed.
1694 	 * If it is changing reset the level on entries that were
1695 	 * set up to be direct when they were created.
1696 	 */
1697 	if (smack_cipso_direct != i) {
1698 		mutex_lock(&smack_known_lock);
1699 		list_for_each_entry_rcu(skp, &smack_known_list, list)
1700 			if (skp->smk_netlabel.attr.mls.lvl ==
1701 			    smack_cipso_direct)
1702 				skp->smk_netlabel.attr.mls.lvl = i;
1703 		smack_cipso_direct = i;
1704 		mutex_unlock(&smack_known_lock);
1705 	}
1706 
1707 	return count;
1708 }
1709 
1710 static const struct file_operations smk_direct_ops = {
1711 	.read		= smk_read_direct,
1712 	.write		= smk_write_direct,
1713 	.llseek		= default_llseek,
1714 };
1715 
1716 /**
1717  * smk_read_mapped - read() for /smack/mapped
1718  * @filp: file pointer, not actually used
1719  * @buf: where to put the result
1720  * @count: maximum to send along
1721  * @ppos: where to start
1722  *
1723  * Returns number of bytes read or error code, as appropriate
1724  */
smk_read_mapped(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1725 static ssize_t smk_read_mapped(struct file *filp, char __user *buf,
1726 			       size_t count, loff_t *ppos)
1727 {
1728 	char temp[80];
1729 	ssize_t rc;
1730 
1731 	if (*ppos != 0)
1732 		return 0;
1733 
1734 	sprintf(temp, "%d", smack_cipso_mapped);
1735 	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
1736 
1737 	return rc;
1738 }
1739 
1740 /**
1741  * smk_write_mapped - write() for /smack/mapped
1742  * @file: file pointer, not actually used
1743  * @buf: where to get the data from
1744  * @count: bytes sent
1745  * @ppos: where to start
1746  *
1747  * Returns number of bytes written or error code, as appropriate
1748  */
smk_write_mapped(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1749 static ssize_t smk_write_mapped(struct file *file, const char __user *buf,
1750 				size_t count, loff_t *ppos)
1751 {
1752 	struct smack_known *skp;
1753 	char temp[80];
1754 	int i;
1755 
1756 	if (!smack_privileged(CAP_MAC_ADMIN))
1757 		return -EPERM;
1758 
1759 	if (count >= sizeof(temp) || count == 0)
1760 		return -EINVAL;
1761 
1762 	if (copy_from_user(temp, buf, count) != 0)
1763 		return -EFAULT;
1764 
1765 	temp[count] = '\0';
1766 
1767 	if (sscanf(temp, "%d", &i) != 1)
1768 		return -EINVAL;
1769 
1770 	/*
1771 	 * Don't do anything if the value hasn't actually changed.
1772 	 * If it is changing reset the level on entries that were
1773 	 * set up to be mapped when they were created.
1774 	 */
1775 	if (smack_cipso_mapped != i) {
1776 		mutex_lock(&smack_known_lock);
1777 		list_for_each_entry_rcu(skp, &smack_known_list, list)
1778 			if (skp->smk_netlabel.attr.mls.lvl ==
1779 			    smack_cipso_mapped)
1780 				skp->smk_netlabel.attr.mls.lvl = i;
1781 		smack_cipso_mapped = i;
1782 		mutex_unlock(&smack_known_lock);
1783 	}
1784 
1785 	return count;
1786 }
1787 
1788 static const struct file_operations smk_mapped_ops = {
1789 	.read		= smk_read_mapped,
1790 	.write		= smk_write_mapped,
1791 	.llseek		= default_llseek,
1792 };
1793 
1794 /**
1795  * smk_read_ambient - read() for /smack/ambient
1796  * @filp: file pointer, not actually used
1797  * @buf: where to put the result
1798  * @cn: maximum to send along
1799  * @ppos: where to start
1800  *
1801  * Returns number of bytes read or error code, as appropriate
1802  */
smk_read_ambient(struct file * filp,char __user * buf,size_t cn,loff_t * ppos)1803 static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
1804 				size_t cn, loff_t *ppos)
1805 {
1806 	ssize_t rc;
1807 	int asize;
1808 
1809 	if (*ppos != 0)
1810 		return 0;
1811 	/*
1812 	 * Being careful to avoid a problem in the case where
1813 	 * smack_net_ambient gets changed in midstream.
1814 	 */
1815 	mutex_lock(&smack_ambient_lock);
1816 
1817 	asize = strlen(smack_net_ambient->smk_known) + 1;
1818 
1819 	if (cn >= asize)
1820 		rc = simple_read_from_buffer(buf, cn, ppos,
1821 					     smack_net_ambient->smk_known,
1822 					     asize);
1823 	else
1824 		rc = -EINVAL;
1825 
1826 	mutex_unlock(&smack_ambient_lock);
1827 
1828 	return rc;
1829 }
1830 
1831 /**
1832  * smk_write_ambient - write() for /smack/ambient
1833  * @file: file pointer, not actually used
1834  * @buf: where to get the data from
1835  * @count: bytes sent
1836  * @ppos: where to start
1837  *
1838  * Returns number of bytes written or error code, as appropriate
1839  */
smk_write_ambient(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1840 static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
1841 				 size_t count, loff_t *ppos)
1842 {
1843 	struct smack_known *skp;
1844 	char *oldambient;
1845 	char *data;
1846 	int rc = count;
1847 
1848 	if (!smack_privileged(CAP_MAC_ADMIN))
1849 		return -EPERM;
1850 
1851 	/* Enough data must be present */
1852 	if (count == 0 || count > PAGE_SIZE)
1853 		return -EINVAL;
1854 
1855 	data = memdup_user_nul(buf, count);
1856 	if (IS_ERR(data))
1857 		return PTR_ERR(data);
1858 
1859 	skp = smk_import_entry(data, count);
1860 	if (IS_ERR(skp)) {
1861 		rc = PTR_ERR(skp);
1862 		goto out;
1863 	}
1864 
1865 	mutex_lock(&smack_ambient_lock);
1866 
1867 	oldambient = smack_net_ambient->smk_known;
1868 	smack_net_ambient = skp;
1869 	smk_unlbl_ambient(oldambient);
1870 
1871 	mutex_unlock(&smack_ambient_lock);
1872 
1873 out:
1874 	kfree(data);
1875 	return rc;
1876 }
1877 
1878 static const struct file_operations smk_ambient_ops = {
1879 	.read		= smk_read_ambient,
1880 	.write		= smk_write_ambient,
1881 	.llseek		= default_llseek,
1882 };
1883 
1884 /*
1885  * Seq_file operations for /smack/onlycap
1886  */
onlycap_seq_start(struct seq_file * s,loff_t * pos)1887 static void *onlycap_seq_start(struct seq_file *s, loff_t *pos)
1888 {
1889 	return smk_seq_start(s, pos, &smack_onlycap_list);
1890 }
1891 
onlycap_seq_next(struct seq_file * s,void * v,loff_t * pos)1892 static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos)
1893 {
1894 	return smk_seq_next(s, v, pos, &smack_onlycap_list);
1895 }
1896 
onlycap_seq_show(struct seq_file * s,void * v)1897 static int onlycap_seq_show(struct seq_file *s, void *v)
1898 {
1899 	struct list_head *list = v;
1900 	struct smack_known_list_elem *sklep =
1901 		list_entry_rcu(list, struct smack_known_list_elem, list);
1902 
1903 	seq_puts(s, sklep->smk_label->smk_known);
1904 	seq_putc(s, ' ');
1905 
1906 	return 0;
1907 }
1908 
1909 static const struct seq_operations onlycap_seq_ops = {
1910 	.start = onlycap_seq_start,
1911 	.next  = onlycap_seq_next,
1912 	.show  = onlycap_seq_show,
1913 	.stop  = smk_seq_stop,
1914 };
1915 
smk_open_onlycap(struct inode * inode,struct file * file)1916 static int smk_open_onlycap(struct inode *inode, struct file *file)
1917 {
1918 	return seq_open(file, &onlycap_seq_ops);
1919 }
1920 
1921 /**
1922  * smk_list_swap_rcu - swap public list with a private one in RCU-safe way
1923  * The caller must hold appropriate mutex to prevent concurrent modifications
1924  * to the public list.
1925  * Private list is assumed to be not accessible to other threads yet.
1926  *
1927  * @public: public list
1928  * @private: private list
1929  */
smk_list_swap_rcu(struct list_head * public,struct list_head * private)1930 static void smk_list_swap_rcu(struct list_head *public,
1931 			      struct list_head *private)
1932 {
1933 	struct list_head *first, *last;
1934 
1935 	if (list_empty(public)) {
1936 		list_splice_init_rcu(private, public, synchronize_rcu);
1937 	} else {
1938 		/* Remember public list before replacing it */
1939 		first = public->next;
1940 		last = public->prev;
1941 
1942 		/* Publish private list in place of public in RCU-safe way */
1943 		private->prev->next = public;
1944 		private->next->prev = public;
1945 		rcu_assign_pointer(public->next, private->next);
1946 		public->prev = private->prev;
1947 
1948 		synchronize_rcu();
1949 
1950 		/* When all readers are done with the old public list,
1951 		 * attach it in place of private */
1952 		private->next = first;
1953 		private->prev = last;
1954 		first->prev = private;
1955 		last->next = private;
1956 	}
1957 }
1958 
1959 /**
1960  * smk_parse_label_list - parse list of Smack labels, separated by spaces
1961  *
1962  * @data: the string to parse
1963  * @list: destination list
1964  *
1965  * Returns zero on success or error code, as appropriate
1966  */
smk_parse_label_list(char * data,struct list_head * list)1967 static int smk_parse_label_list(char *data, struct list_head *list)
1968 {
1969 	char *tok;
1970 	struct smack_known *skp;
1971 	struct smack_known_list_elem *sklep;
1972 
1973 	while ((tok = strsep(&data, " ")) != NULL) {
1974 		if (!*tok)
1975 			continue;
1976 
1977 		skp = smk_import_entry(tok, 0);
1978 		if (IS_ERR(skp))
1979 			return PTR_ERR(skp);
1980 
1981 		sklep = kzalloc(sizeof(*sklep), GFP_KERNEL);
1982 		if (sklep == NULL)
1983 			return -ENOMEM;
1984 
1985 		sklep->smk_label = skp;
1986 		list_add(&sklep->list, list);
1987 	}
1988 
1989 	return 0;
1990 }
1991 
1992 /**
1993  * smk_destroy_label_list - destroy a list of smack_known_list_elem
1994  * @list: header pointer of the list to destroy
1995  */
smk_destroy_label_list(struct list_head * list)1996 void smk_destroy_label_list(struct list_head *list)
1997 {
1998 	struct smack_known_list_elem *sklep;
1999 	struct smack_known_list_elem *sklep2;
2000 
2001 	list_for_each_entry_safe(sklep, sklep2, list, list)
2002 		kfree(sklep);
2003 
2004 	INIT_LIST_HEAD(list);
2005 }
2006 
2007 /**
2008  * smk_write_onlycap - write() for smackfs/onlycap
2009  * @file: file pointer, not actually used
2010  * @buf: where to get the data from
2011  * @count: bytes sent
2012  * @ppos: where to start
2013  *
2014  * Returns number of bytes written or error code, as appropriate
2015  */
smk_write_onlycap(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2016 static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
2017 				 size_t count, loff_t *ppos)
2018 {
2019 	char *data;
2020 	LIST_HEAD(list_tmp);
2021 	int rc;
2022 
2023 	if (!smack_privileged(CAP_MAC_ADMIN))
2024 		return -EPERM;
2025 
2026 	if (count > PAGE_SIZE)
2027 		return -EINVAL;
2028 
2029 	data = memdup_user_nul(buf, count);
2030 	if (IS_ERR(data))
2031 		return PTR_ERR(data);
2032 
2033 	rc = smk_parse_label_list(data, &list_tmp);
2034 	kfree(data);
2035 
2036 	/*
2037 	 * Clear the smack_onlycap on invalid label errors. This means
2038 	 * that we can pass a null string to unset the onlycap value.
2039 	 *
2040 	 * Importing will also reject a label beginning with '-',
2041 	 * so "-usecapabilities" will also work.
2042 	 *
2043 	 * But do so only on invalid label, not on system errors.
2044 	 * The invalid label must be first to count as clearing attempt.
2045 	 */
2046 	if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) {
2047 		mutex_lock(&smack_onlycap_lock);
2048 		smk_list_swap_rcu(&smack_onlycap_list, &list_tmp);
2049 		mutex_unlock(&smack_onlycap_lock);
2050 		rc = count;
2051 	}
2052 
2053 	smk_destroy_label_list(&list_tmp);
2054 
2055 	return rc;
2056 }
2057 
2058 static const struct file_operations smk_onlycap_ops = {
2059 	.open		= smk_open_onlycap,
2060 	.read		= seq_read,
2061 	.write		= smk_write_onlycap,
2062 	.llseek		= seq_lseek,
2063 	.release	= seq_release,
2064 };
2065 
2066 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
2067 /**
2068  * smk_read_unconfined - read() for smackfs/unconfined
2069  * @filp: file pointer, not actually used
2070  * @buf: where to put the result
2071  * @cn: maximum to send along
2072  * @ppos: where to start
2073  *
2074  * Returns number of bytes read or error code, as appropriate
2075  */
smk_read_unconfined(struct file * filp,char __user * buf,size_t cn,loff_t * ppos)2076 static ssize_t smk_read_unconfined(struct file *filp, char __user *buf,
2077 					size_t cn, loff_t *ppos)
2078 {
2079 	char *smack = "";
2080 	ssize_t rc = -EINVAL;
2081 	int asize;
2082 
2083 	if (*ppos != 0)
2084 		return 0;
2085 
2086 	if (smack_unconfined != NULL)
2087 		smack = smack_unconfined->smk_known;
2088 
2089 	asize = strlen(smack) + 1;
2090 
2091 	if (cn >= asize)
2092 		rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
2093 
2094 	return rc;
2095 }
2096 
2097 /**
2098  * smk_write_unconfined - write() for smackfs/unconfined
2099  * @file: file pointer, not actually used
2100  * @buf: where to get the data from
2101  * @count: bytes sent
2102  * @ppos: where to start
2103  *
2104  * Returns number of bytes written or error code, as appropriate
2105  */
smk_write_unconfined(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2106 static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
2107 					size_t count, loff_t *ppos)
2108 {
2109 	char *data;
2110 	struct smack_known *skp;
2111 	int rc = count;
2112 
2113 	if (!smack_privileged(CAP_MAC_ADMIN))
2114 		return -EPERM;
2115 
2116 	if (count > PAGE_SIZE)
2117 		return -EINVAL;
2118 
2119 	data = memdup_user_nul(buf, count);
2120 	if (IS_ERR(data))
2121 		return PTR_ERR(data);
2122 
2123 	/*
2124 	 * Clear the smack_unconfined on invalid label errors. This means
2125 	 * that we can pass a null string to unset the unconfined value.
2126 	 *
2127 	 * Importing will also reject a label beginning with '-',
2128 	 * so "-confine" will also work.
2129 	 *
2130 	 * But do so only on invalid label, not on system errors.
2131 	 */
2132 	skp = smk_import_entry(data, count);
2133 	if (PTR_ERR(skp) == -EINVAL)
2134 		skp = NULL;
2135 	else if (IS_ERR(skp)) {
2136 		rc = PTR_ERR(skp);
2137 		goto freeout;
2138 	}
2139 
2140 	smack_unconfined = skp;
2141 
2142 freeout:
2143 	kfree(data);
2144 	return rc;
2145 }
2146 
2147 static const struct file_operations smk_unconfined_ops = {
2148 	.read		= smk_read_unconfined,
2149 	.write		= smk_write_unconfined,
2150 	.llseek		= default_llseek,
2151 };
2152 #endif /* CONFIG_SECURITY_SMACK_BRINGUP */
2153 
2154 /**
2155  * smk_read_logging - read() for /smack/logging
2156  * @filp: file pointer, not actually used
2157  * @buf: where to put the result
2158  * @count: maximum to send along
2159  * @ppos: where to start
2160  *
2161  * Returns number of bytes read or error code, as appropriate
2162  */
smk_read_logging(struct file * filp,char __user * buf,size_t count,loff_t * ppos)2163 static ssize_t smk_read_logging(struct file *filp, char __user *buf,
2164 				size_t count, loff_t *ppos)
2165 {
2166 	char temp[32];
2167 	ssize_t rc;
2168 
2169 	if (*ppos != 0)
2170 		return 0;
2171 
2172 	sprintf(temp, "%d\n", log_policy);
2173 	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
2174 	return rc;
2175 }
2176 
2177 /**
2178  * smk_write_logging - write() for /smack/logging
2179  * @file: file pointer, not actually used
2180  * @buf: where to get the data from
2181  * @count: bytes sent
2182  * @ppos: where to start
2183  *
2184  * Returns number of bytes written or error code, as appropriate
2185  */
smk_write_logging(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2186 static ssize_t smk_write_logging(struct file *file, const char __user *buf,
2187 				size_t count, loff_t *ppos)
2188 {
2189 	char temp[32];
2190 	int i;
2191 
2192 	if (!smack_privileged(CAP_MAC_ADMIN))
2193 		return -EPERM;
2194 
2195 	if (count >= sizeof(temp) || count == 0)
2196 		return -EINVAL;
2197 
2198 	if (copy_from_user(temp, buf, count) != 0)
2199 		return -EFAULT;
2200 
2201 	temp[count] = '\0';
2202 
2203 	if (sscanf(temp, "%d", &i) != 1)
2204 		return -EINVAL;
2205 	if (i < 0 || i > 3)
2206 		return -EINVAL;
2207 	log_policy = i;
2208 	return count;
2209 }
2210 
2211 
2212 
2213 static const struct file_operations smk_logging_ops = {
2214 	.read		= smk_read_logging,
2215 	.write		= smk_write_logging,
2216 	.llseek		= default_llseek,
2217 };
2218 
2219 /*
2220  * Seq_file read operations for /smack/load-self
2221  */
2222 
load_self_seq_start(struct seq_file * s,loff_t * pos)2223 static void *load_self_seq_start(struct seq_file *s, loff_t *pos)
2224 {
2225 	struct task_smack *tsp = smack_cred(current_cred());
2226 
2227 	return smk_seq_start(s, pos, &tsp->smk_rules);
2228 }
2229 
load_self_seq_next(struct seq_file * s,void * v,loff_t * pos)2230 static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
2231 {
2232 	struct task_smack *tsp = smack_cred(current_cred());
2233 
2234 	return smk_seq_next(s, v, pos, &tsp->smk_rules);
2235 }
2236 
load_self_seq_show(struct seq_file * s,void * v)2237 static int load_self_seq_show(struct seq_file *s, void *v)
2238 {
2239 	struct list_head *list = v;
2240 	struct smack_rule *srp =
2241 		list_entry_rcu(list, struct smack_rule, list);
2242 
2243 	smk_rule_show(s, srp, SMK_LABELLEN);
2244 
2245 	return 0;
2246 }
2247 
2248 static const struct seq_operations load_self_seq_ops = {
2249 	.start = load_self_seq_start,
2250 	.next  = load_self_seq_next,
2251 	.show  = load_self_seq_show,
2252 	.stop  = smk_seq_stop,
2253 };
2254 
2255 
2256 /**
2257  * smk_open_load_self - open() for /smack/load-self2
2258  * @inode: inode structure representing file
2259  * @file: "load" file pointer
2260  *
2261  * For reading, use load_seq_* seq_file reading operations.
2262  */
smk_open_load_self(struct inode * inode,struct file * file)2263 static int smk_open_load_self(struct inode *inode, struct file *file)
2264 {
2265 	return seq_open(file, &load_self_seq_ops);
2266 }
2267 
2268 /**
2269  * smk_write_load_self - write() for /smack/load-self
2270  * @file: file pointer, not actually used
2271  * @buf: where to get the data from
2272  * @count: bytes sent
2273  * @ppos: where to start - must be 0
2274  *
2275  */
smk_write_load_self(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2276 static ssize_t smk_write_load_self(struct file *file, const char __user *buf,
2277 			      size_t count, loff_t *ppos)
2278 {
2279 	struct task_smack *tsp = smack_cred(current_cred());
2280 
2281 	return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
2282 				    &tsp->smk_rules_lock, SMK_FIXED24_FMT);
2283 }
2284 
2285 static const struct file_operations smk_load_self_ops = {
2286 	.open           = smk_open_load_self,
2287 	.read		= seq_read,
2288 	.llseek         = seq_lseek,
2289 	.write		= smk_write_load_self,
2290 	.release        = seq_release,
2291 };
2292 
2293 /**
2294  * smk_user_access - handle access check transaction
2295  * @file: file pointer
2296  * @buf: data from user space
2297  * @count: bytes sent
2298  * @ppos: where to start - must be 0
2299  * @format: /smack/load or /smack/load2 or /smack/change-rule format.
2300  */
smk_user_access(struct file * file,const char __user * buf,size_t count,loff_t * ppos,int format)2301 static ssize_t smk_user_access(struct file *file, const char __user *buf,
2302 				size_t count, loff_t *ppos, int format)
2303 {
2304 	struct smack_parsed_rule rule;
2305 	char *data;
2306 	int res;
2307 
2308 	data = simple_transaction_get(file, buf, count);
2309 	if (IS_ERR(data))
2310 		return PTR_ERR(data);
2311 
2312 	if (format == SMK_FIXED24_FMT) {
2313 		if (count < SMK_LOADLEN)
2314 			return -EINVAL;
2315 		res = smk_parse_rule(data, &rule, 0);
2316 	} else {
2317 		/*
2318 		 * simple_transaction_get() returns null-terminated data
2319 		 */
2320 		res = smk_parse_long_rule(data, &rule, 0, 3);
2321 	}
2322 
2323 	if (res >= 0)
2324 		res = smk_access(rule.smk_subject, rule.smk_object,
2325 				 rule.smk_access1, NULL);
2326 	else if (res != -ENOENT)
2327 		return res;
2328 
2329 	/*
2330 	 * smk_access() can return a value > 0 in the "bringup" case.
2331 	 */
2332 	data[0] = res >= 0 ? '1' : '0';
2333 	data[1] = '\0';
2334 
2335 	simple_transaction_set(file, 2);
2336 
2337 	if (format == SMK_FIXED24_FMT)
2338 		return SMK_LOADLEN;
2339 	return count;
2340 }
2341 
2342 /**
2343  * smk_write_access - handle access check transaction
2344  * @file: file pointer
2345  * @buf: data from user space
2346  * @count: bytes sent
2347  * @ppos: where to start - must be 0
2348  */
smk_write_access(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2349 static ssize_t smk_write_access(struct file *file, const char __user *buf,
2350 				size_t count, loff_t *ppos)
2351 {
2352 	return smk_user_access(file, buf, count, ppos, SMK_FIXED24_FMT);
2353 }
2354 
2355 static const struct file_operations smk_access_ops = {
2356 	.write		= smk_write_access,
2357 	.read		= simple_transaction_read,
2358 	.release	= simple_transaction_release,
2359 	.llseek		= generic_file_llseek,
2360 };
2361 
2362 
2363 /*
2364  * Seq_file read operations for /smack/load2
2365  */
2366 
load2_seq_show(struct seq_file * s,void * v)2367 static int load2_seq_show(struct seq_file *s, void *v)
2368 {
2369 	struct list_head *list = v;
2370 	struct smack_rule *srp;
2371 	struct smack_known *skp =
2372 		list_entry_rcu(list, struct smack_known, list);
2373 
2374 	list_for_each_entry_rcu(srp, &skp->smk_rules, list)
2375 		smk_rule_show(s, srp, SMK_LONGLABEL);
2376 
2377 	return 0;
2378 }
2379 
2380 static const struct seq_operations load2_seq_ops = {
2381 	.start = load2_seq_start,
2382 	.next  = load2_seq_next,
2383 	.show  = load2_seq_show,
2384 	.stop  = smk_seq_stop,
2385 };
2386 
2387 /**
2388  * smk_open_load2 - open() for /smack/load2
2389  * @inode: inode structure representing file
2390  * @file: "load2" file pointer
2391  *
2392  * For reading, use load2_seq_* seq_file reading operations.
2393  */
smk_open_load2(struct inode * inode,struct file * file)2394 static int smk_open_load2(struct inode *inode, struct file *file)
2395 {
2396 	return seq_open(file, &load2_seq_ops);
2397 }
2398 
2399 /**
2400  * smk_write_load2 - write() for /smack/load2
2401  * @file: file pointer, not actually used
2402  * @buf: where to get the data from
2403  * @count: bytes sent
2404  * @ppos: where to start - must be 0
2405  *
2406  */
smk_write_load2(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2407 static ssize_t smk_write_load2(struct file *file, const char __user *buf,
2408 				size_t count, loff_t *ppos)
2409 {
2410 	/*
2411 	 * Must have privilege.
2412 	 */
2413 	if (!smack_privileged(CAP_MAC_ADMIN))
2414 		return -EPERM;
2415 
2416 	return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
2417 				    SMK_LONG_FMT);
2418 }
2419 
2420 static const struct file_operations smk_load2_ops = {
2421 	.open           = smk_open_load2,
2422 	.read		= seq_read,
2423 	.llseek         = seq_lseek,
2424 	.write		= smk_write_load2,
2425 	.release        = seq_release,
2426 };
2427 
2428 /*
2429  * Seq_file read operations for /smack/load-self2
2430  */
2431 
load_self2_seq_start(struct seq_file * s,loff_t * pos)2432 static void *load_self2_seq_start(struct seq_file *s, loff_t *pos)
2433 {
2434 	struct task_smack *tsp = smack_cred(current_cred());
2435 
2436 	return smk_seq_start(s, pos, &tsp->smk_rules);
2437 }
2438 
load_self2_seq_next(struct seq_file * s,void * v,loff_t * pos)2439 static void *load_self2_seq_next(struct seq_file *s, void *v, loff_t *pos)
2440 {
2441 	struct task_smack *tsp = smack_cred(current_cred());
2442 
2443 	return smk_seq_next(s, v, pos, &tsp->smk_rules);
2444 }
2445 
load_self2_seq_show(struct seq_file * s,void * v)2446 static int load_self2_seq_show(struct seq_file *s, void *v)
2447 {
2448 	struct list_head *list = v;
2449 	struct smack_rule *srp =
2450 		list_entry_rcu(list, struct smack_rule, list);
2451 
2452 	smk_rule_show(s, srp, SMK_LONGLABEL);
2453 
2454 	return 0;
2455 }
2456 
2457 static const struct seq_operations load_self2_seq_ops = {
2458 	.start = load_self2_seq_start,
2459 	.next  = load_self2_seq_next,
2460 	.show  = load_self2_seq_show,
2461 	.stop  = smk_seq_stop,
2462 };
2463 
2464 /**
2465  * smk_open_load_self2 - open() for /smack/load-self2
2466  * @inode: inode structure representing file
2467  * @file: "load" file pointer
2468  *
2469  * For reading, use load_seq_* seq_file reading operations.
2470  */
smk_open_load_self2(struct inode * inode,struct file * file)2471 static int smk_open_load_self2(struct inode *inode, struct file *file)
2472 {
2473 	return seq_open(file, &load_self2_seq_ops);
2474 }
2475 
2476 /**
2477  * smk_write_load_self2 - write() for /smack/load-self2
2478  * @file: file pointer, not actually used
2479  * @buf: where to get the data from
2480  * @count: bytes sent
2481  * @ppos: where to start - must be 0
2482  *
2483  */
smk_write_load_self2(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2484 static ssize_t smk_write_load_self2(struct file *file, const char __user *buf,
2485 			      size_t count, loff_t *ppos)
2486 {
2487 	struct task_smack *tsp = smack_cred(current_cred());
2488 
2489 	return smk_write_rules_list(file, buf, count, ppos, &tsp->smk_rules,
2490 				    &tsp->smk_rules_lock, SMK_LONG_FMT);
2491 }
2492 
2493 static const struct file_operations smk_load_self2_ops = {
2494 	.open           = smk_open_load_self2,
2495 	.read		= seq_read,
2496 	.llseek         = seq_lseek,
2497 	.write		= smk_write_load_self2,
2498 	.release        = seq_release,
2499 };
2500 
2501 /**
2502  * smk_write_access2 - handle access check transaction
2503  * @file: file pointer
2504  * @buf: data from user space
2505  * @count: bytes sent
2506  * @ppos: where to start - must be 0
2507  */
smk_write_access2(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2508 static ssize_t smk_write_access2(struct file *file, const char __user *buf,
2509 					size_t count, loff_t *ppos)
2510 {
2511 	return smk_user_access(file, buf, count, ppos, SMK_LONG_FMT);
2512 }
2513 
2514 static const struct file_operations smk_access2_ops = {
2515 	.write		= smk_write_access2,
2516 	.read		= simple_transaction_read,
2517 	.release	= simple_transaction_release,
2518 	.llseek		= generic_file_llseek,
2519 };
2520 
2521 /**
2522  * smk_write_revoke_subj - write() for /smack/revoke-subject
2523  * @file: file pointer
2524  * @buf: data from user space
2525  * @count: bytes sent
2526  * @ppos: where to start - must be 0
2527  */
smk_write_revoke_subj(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2528 static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
2529 				size_t count, loff_t *ppos)
2530 {
2531 	char *data;
2532 	const char *cp;
2533 	struct smack_known *skp;
2534 	struct smack_rule *sp;
2535 	struct list_head *rule_list;
2536 	struct mutex *rule_lock;
2537 	int rc = count;
2538 
2539 	if (*ppos != 0)
2540 		return -EINVAL;
2541 
2542 	if (!smack_privileged(CAP_MAC_ADMIN))
2543 		return -EPERM;
2544 
2545 	if (count == 0 || count > SMK_LONGLABEL)
2546 		return -EINVAL;
2547 
2548 	data = memdup_user(buf, count);
2549 	if (IS_ERR(data))
2550 		return PTR_ERR(data);
2551 
2552 	cp = smk_parse_smack(data, count);
2553 	if (IS_ERR(cp)) {
2554 		rc = PTR_ERR(cp);
2555 		goto out_data;
2556 	}
2557 
2558 	skp = smk_find_entry(cp);
2559 	if (skp == NULL)
2560 		goto out_cp;
2561 
2562 	rule_list = &skp->smk_rules;
2563 	rule_lock = &skp->smk_rules_lock;
2564 
2565 	mutex_lock(rule_lock);
2566 
2567 	list_for_each_entry_rcu(sp, rule_list, list)
2568 		sp->smk_access = 0;
2569 
2570 	mutex_unlock(rule_lock);
2571 
2572 out_cp:
2573 	kfree(cp);
2574 out_data:
2575 	kfree(data);
2576 
2577 	return rc;
2578 }
2579 
2580 static const struct file_operations smk_revoke_subj_ops = {
2581 	.write		= smk_write_revoke_subj,
2582 	.read		= simple_transaction_read,
2583 	.release	= simple_transaction_release,
2584 	.llseek		= generic_file_llseek,
2585 };
2586 
2587 /**
2588  * smk_init_sysfs - initialize /sys/fs/smackfs
2589  *
2590  */
smk_init_sysfs(void)2591 static int smk_init_sysfs(void)
2592 {
2593 	return sysfs_create_mount_point(fs_kobj, "smackfs");
2594 }
2595 
2596 /**
2597  * smk_write_change_rule - write() for /smack/change-rule
2598  * @file: file pointer
2599  * @buf: data from user space
2600  * @count: bytes sent
2601  * @ppos: where to start - must be 0
2602  */
smk_write_change_rule(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2603 static ssize_t smk_write_change_rule(struct file *file, const char __user *buf,
2604 				size_t count, loff_t *ppos)
2605 {
2606 	/*
2607 	 * Must have privilege.
2608 	 */
2609 	if (!smack_privileged(CAP_MAC_ADMIN))
2610 		return -EPERM;
2611 
2612 	return smk_write_rules_list(file, buf, count, ppos, NULL, NULL,
2613 				    SMK_CHANGE_FMT);
2614 }
2615 
2616 static const struct file_operations smk_change_rule_ops = {
2617 	.write		= smk_write_change_rule,
2618 	.read		= simple_transaction_read,
2619 	.release	= simple_transaction_release,
2620 	.llseek		= generic_file_llseek,
2621 };
2622 
2623 /**
2624  * smk_read_syslog - read() for smackfs/syslog
2625  * @filp: file pointer, not actually used
2626  * @buf: where to put the result
2627  * @cn: maximum to send along
2628  * @ppos: where to start
2629  *
2630  * Returns number of bytes read or error code, as appropriate
2631  */
smk_read_syslog(struct file * filp,char __user * buf,size_t cn,loff_t * ppos)2632 static ssize_t smk_read_syslog(struct file *filp, char __user *buf,
2633 				size_t cn, loff_t *ppos)
2634 {
2635 	struct smack_known *skp;
2636 	ssize_t rc = -EINVAL;
2637 	int asize;
2638 
2639 	if (*ppos != 0)
2640 		return 0;
2641 
2642 	if (smack_syslog_label == NULL)
2643 		skp = &smack_known_star;
2644 	else
2645 		skp = smack_syslog_label;
2646 
2647 	asize = strlen(skp->smk_known) + 1;
2648 
2649 	if (cn >= asize)
2650 		rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known,
2651 						asize);
2652 
2653 	return rc;
2654 }
2655 
2656 /**
2657  * smk_write_syslog - write() for smackfs/syslog
2658  * @file: file pointer, not actually used
2659  * @buf: where to get the data from
2660  * @count: bytes sent
2661  * @ppos: where to start
2662  *
2663  * Returns number of bytes written or error code, as appropriate
2664  */
smk_write_syslog(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2665 static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
2666 				size_t count, loff_t *ppos)
2667 {
2668 	char *data;
2669 	struct smack_known *skp;
2670 	int rc = count;
2671 
2672 	if (!smack_privileged(CAP_MAC_ADMIN))
2673 		return -EPERM;
2674 
2675 	/* Enough data must be present */
2676 	if (count == 0 || count > PAGE_SIZE)
2677 		return -EINVAL;
2678 
2679 	data = memdup_user_nul(buf, count);
2680 	if (IS_ERR(data))
2681 		return PTR_ERR(data);
2682 
2683 	skp = smk_import_entry(data, count);
2684 	if (IS_ERR(skp))
2685 		rc = PTR_ERR(skp);
2686 	else
2687 		smack_syslog_label = skp;
2688 
2689 	kfree(data);
2690 	return rc;
2691 }
2692 
2693 static const struct file_operations smk_syslog_ops = {
2694 	.read		= smk_read_syslog,
2695 	.write		= smk_write_syslog,
2696 	.llseek		= default_llseek,
2697 };
2698 
2699 /*
2700  * Seq_file read operations for /smack/relabel-self
2701  */
2702 
relabel_self_seq_start(struct seq_file * s,loff_t * pos)2703 static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos)
2704 {
2705 	struct task_smack *tsp = smack_cred(current_cred());
2706 
2707 	return smk_seq_start(s, pos, &tsp->smk_relabel);
2708 }
2709 
relabel_self_seq_next(struct seq_file * s,void * v,loff_t * pos)2710 static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos)
2711 {
2712 	struct task_smack *tsp = smack_cred(current_cred());
2713 
2714 	return smk_seq_next(s, v, pos, &tsp->smk_relabel);
2715 }
2716 
relabel_self_seq_show(struct seq_file * s,void * v)2717 static int relabel_self_seq_show(struct seq_file *s, void *v)
2718 {
2719 	struct list_head *list = v;
2720 	struct smack_known_list_elem *sklep =
2721 		list_entry(list, struct smack_known_list_elem, list);
2722 
2723 	seq_puts(s, sklep->smk_label->smk_known);
2724 	seq_putc(s, ' ');
2725 
2726 	return 0;
2727 }
2728 
2729 static const struct seq_operations relabel_self_seq_ops = {
2730 	.start = relabel_self_seq_start,
2731 	.next  = relabel_self_seq_next,
2732 	.show  = relabel_self_seq_show,
2733 	.stop  = smk_seq_stop,
2734 };
2735 
2736 /**
2737  * smk_open_relabel_self - open() for /smack/relabel-self
2738  * @inode: inode structure representing file
2739  * @file: "relabel-self" file pointer
2740  *
2741  * Connect our relabel_self_seq_* operations with /smack/relabel-self
2742  * file_operations
2743  */
smk_open_relabel_self(struct inode * inode,struct file * file)2744 static int smk_open_relabel_self(struct inode *inode, struct file *file)
2745 {
2746 	return seq_open(file, &relabel_self_seq_ops);
2747 }
2748 
2749 /**
2750  * smk_write_relabel_self - write() for /smack/relabel-self
2751  * @file: file pointer, not actually used
2752  * @buf: where to get the data from
2753  * @count: bytes sent
2754  * @ppos: where to start - must be 0
2755  *
2756  */
smk_write_relabel_self(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2757 static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
2758 				size_t count, loff_t *ppos)
2759 {
2760 	char *data;
2761 	int rc;
2762 	LIST_HEAD(list_tmp);
2763 
2764 	/*
2765 	 * Must have privilege.
2766 	 */
2767 	if (!smack_privileged(CAP_MAC_ADMIN))
2768 		return -EPERM;
2769 
2770 	/*
2771 	 * No partial write.
2772 	 * Enough data must be present.
2773 	 */
2774 	if (*ppos != 0)
2775 		return -EINVAL;
2776 	if (count == 0 || count > PAGE_SIZE)
2777 		return -EINVAL;
2778 
2779 	data = memdup_user_nul(buf, count);
2780 	if (IS_ERR(data))
2781 		return PTR_ERR(data);
2782 
2783 	rc = smk_parse_label_list(data, &list_tmp);
2784 	kfree(data);
2785 
2786 	if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) {
2787 		struct cred *new;
2788 		struct task_smack *tsp;
2789 
2790 		new = prepare_creds();
2791 		if (!new) {
2792 			rc = -ENOMEM;
2793 			goto out;
2794 		}
2795 		tsp = smack_cred(new);
2796 		smk_destroy_label_list(&tsp->smk_relabel);
2797 		list_splice(&list_tmp, &tsp->smk_relabel);
2798 		commit_creds(new);
2799 		return count;
2800 	}
2801 out:
2802 	smk_destroy_label_list(&list_tmp);
2803 	return rc;
2804 }
2805 
2806 static const struct file_operations smk_relabel_self_ops = {
2807 	.open		= smk_open_relabel_self,
2808 	.read		= seq_read,
2809 	.llseek		= seq_lseek,
2810 	.write		= smk_write_relabel_self,
2811 	.release	= seq_release,
2812 };
2813 
2814 /**
2815  * smk_read_ptrace - read() for /smack/ptrace
2816  * @filp: file pointer, not actually used
2817  * @buf: where to put the result
2818  * @count: maximum to send along
2819  * @ppos: where to start
2820  *
2821  * Returns number of bytes read or error code, as appropriate
2822  */
smk_read_ptrace(struct file * filp,char __user * buf,size_t count,loff_t * ppos)2823 static ssize_t smk_read_ptrace(struct file *filp, char __user *buf,
2824 			       size_t count, loff_t *ppos)
2825 {
2826 	char temp[32];
2827 	ssize_t rc;
2828 
2829 	if (*ppos != 0)
2830 		return 0;
2831 
2832 	sprintf(temp, "%d\n", smack_ptrace_rule);
2833 	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
2834 	return rc;
2835 }
2836 
2837 /**
2838  * smk_write_ptrace - write() for /smack/ptrace
2839  * @file: file pointer
2840  * @buf: data from user space
2841  * @count: bytes sent
2842  * @ppos: where to start - must be 0
2843  */
smk_write_ptrace(struct file * file,const char __user * buf,size_t count,loff_t * ppos)2844 static ssize_t smk_write_ptrace(struct file *file, const char __user *buf,
2845 				size_t count, loff_t *ppos)
2846 {
2847 	char temp[32];
2848 	int i;
2849 
2850 	if (!smack_privileged(CAP_MAC_ADMIN))
2851 		return -EPERM;
2852 
2853 	if (*ppos != 0 || count >= sizeof(temp) || count == 0)
2854 		return -EINVAL;
2855 
2856 	if (copy_from_user(temp, buf, count) != 0)
2857 		return -EFAULT;
2858 
2859 	temp[count] = '\0';
2860 
2861 	if (sscanf(temp, "%d", &i) != 1)
2862 		return -EINVAL;
2863 	if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX)
2864 		return -EINVAL;
2865 	smack_ptrace_rule = i;
2866 
2867 	return count;
2868 }
2869 
2870 static const struct file_operations smk_ptrace_ops = {
2871 	.write		= smk_write_ptrace,
2872 	.read		= smk_read_ptrace,
2873 	.llseek		= default_llseek,
2874 };
2875 
2876 /**
2877  * smk_fill_super - fill the smackfs superblock
2878  * @sb: the empty superblock
2879  * @fc: unused
2880  *
2881  * Fill in the well known entries for the smack filesystem
2882  *
2883  * Returns 0 on success, an error code on failure
2884  */
smk_fill_super(struct super_block * sb,struct fs_context * fc)2885 static int smk_fill_super(struct super_block *sb, struct fs_context *fc)
2886 {
2887 	int rc;
2888 
2889 	static const struct tree_descr smack_files[] = {
2890 		[SMK_LOAD] = {
2891 			"load", &smk_load_ops, S_IRUGO|S_IWUSR},
2892 		[SMK_CIPSO] = {
2893 			"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR},
2894 		[SMK_DOI] = {
2895 			"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
2896 		[SMK_DIRECT] = {
2897 			"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
2898 		[SMK_AMBIENT] = {
2899 			"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
2900 		[SMK_NET4ADDR] = {
2901 			"netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR},
2902 		[SMK_ONLYCAP] = {
2903 			"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
2904 		[SMK_LOGGING] = {
2905 			"logging", &smk_logging_ops, S_IRUGO|S_IWUSR},
2906 		[SMK_LOAD_SELF] = {
2907 			"load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO},
2908 		[SMK_ACCESSES] = {
2909 			"access", &smk_access_ops, S_IRUGO|S_IWUGO},
2910 		[SMK_MAPPED] = {
2911 			"mapped", &smk_mapped_ops, S_IRUGO|S_IWUSR},
2912 		[SMK_LOAD2] = {
2913 			"load2", &smk_load2_ops, S_IRUGO|S_IWUSR},
2914 		[SMK_LOAD_SELF2] = {
2915 			"load-self2", &smk_load_self2_ops, S_IRUGO|S_IWUGO},
2916 		[SMK_ACCESS2] = {
2917 			"access2", &smk_access2_ops, S_IRUGO|S_IWUGO},
2918 		[SMK_CIPSO2] = {
2919 			"cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR},
2920 		[SMK_REVOKE_SUBJ] = {
2921 			"revoke-subject", &smk_revoke_subj_ops,
2922 			S_IRUGO|S_IWUSR},
2923 		[SMK_CHANGE_RULE] = {
2924 			"change-rule", &smk_change_rule_ops, S_IRUGO|S_IWUSR},
2925 		[SMK_SYSLOG] = {
2926 			"syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR},
2927 		[SMK_PTRACE] = {
2928 			"ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR},
2929 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
2930 		[SMK_UNCONFINED] = {
2931 			"unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR},
2932 #endif
2933 #if IS_ENABLED(CONFIG_IPV6)
2934 		[SMK_NET6ADDR] = {
2935 			"ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR},
2936 #endif /* CONFIG_IPV6 */
2937 		[SMK_RELABEL_SELF] = {
2938 			"relabel-self", &smk_relabel_self_ops,
2939 				S_IRUGO|S_IWUGO},
2940 		/* last one */
2941 			{""}
2942 	};
2943 
2944 	rc = simple_fill_super(sb, SMACK_MAGIC, smack_files);
2945 	if (rc != 0) {
2946 		printk(KERN_ERR "%s failed %d while creating inodes\n",
2947 			__func__, rc);
2948 		return rc;
2949 	}
2950 
2951 	return 0;
2952 }
2953 
2954 /**
2955  * smk_get_tree - get the smackfs superblock
2956  * @fc: The mount context, including any options
2957  *
2958  * Just passes everything along.
2959  *
2960  * Returns what the lower level code does.
2961  */
smk_get_tree(struct fs_context * fc)2962 static int smk_get_tree(struct fs_context *fc)
2963 {
2964 	return get_tree_single(fc, smk_fill_super);
2965 }
2966 
2967 static const struct fs_context_operations smk_context_ops = {
2968 	.get_tree	= smk_get_tree,
2969 };
2970 
2971 /**
2972  * smk_init_fs_context - Initialise a filesystem context for smackfs
2973  * @fc: The blank mount context
2974  */
smk_init_fs_context(struct fs_context * fc)2975 static int smk_init_fs_context(struct fs_context *fc)
2976 {
2977 	fc->ops = &smk_context_ops;
2978 	return 0;
2979 }
2980 
2981 static struct file_system_type smk_fs_type = {
2982 	.name		= "smackfs",
2983 	.init_fs_context = smk_init_fs_context,
2984 	.kill_sb	= kill_litter_super,
2985 };
2986 
2987 static struct vfsmount *smackfs_mount;
2988 
2989 /**
2990  * init_smk_fs - get the smackfs superblock
2991  *
2992  * register the smackfs
2993  *
2994  * Do not register smackfs if Smack wasn't enabled
2995  * on boot. We can not put this method normally under the
2996  * smack_init() code path since the security subsystem get
2997  * initialized before the vfs caches.
2998  *
2999  * Returns true if we were not chosen on boot or if
3000  * we were chosen and filesystem registration succeeded.
3001  */
init_smk_fs(void)3002 static int __init init_smk_fs(void)
3003 {
3004 	int err;
3005 	int rc;
3006 
3007 	if (smack_enabled == 0)
3008 		return 0;
3009 
3010 	err = smk_init_sysfs();
3011 	if (err)
3012 		printk(KERN_ERR "smackfs: sysfs mountpoint problem.\n");
3013 
3014 	err = register_filesystem(&smk_fs_type);
3015 	if (!err) {
3016 		smackfs_mount = kern_mount(&smk_fs_type);
3017 		if (IS_ERR(smackfs_mount)) {
3018 			printk(KERN_ERR "smackfs:  could not mount!\n");
3019 			err = PTR_ERR(smackfs_mount);
3020 			smackfs_mount = NULL;
3021 		}
3022 	}
3023 
3024 	smk_cipso_doi();
3025 	smk_unlbl_ambient(NULL);
3026 
3027 	rc = smack_populate_secattr(&smack_known_floor);
3028 	if (err == 0 && rc < 0)
3029 		err = rc;
3030 	rc = smack_populate_secattr(&smack_known_hat);
3031 	if (err == 0 && rc < 0)
3032 		err = rc;
3033 	rc = smack_populate_secattr(&smack_known_huh);
3034 	if (err == 0 && rc < 0)
3035 		err = rc;
3036 	rc = smack_populate_secattr(&smack_known_star);
3037 	if (err == 0 && rc < 0)
3038 		err = rc;
3039 	rc = smack_populate_secattr(&smack_known_web);
3040 	if (err == 0 && rc < 0)
3041 		err = rc;
3042 
3043 	return err;
3044 }
3045 
3046 __initcall(init_smk_fs);
3047