services.c revision 7ae9f23cbd3ef9daff7f768da4bfd4c56b19300d
1/*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 *	     James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 *	Support for enhanced MLS infrastructure.
10 *	Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 *	Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul.moore@hp.com>
17 *
18 *      Added support for NetLabel
19 *      Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 *  Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 *  Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 *  Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 *	This program is free software; you can redistribute it and/or modify
39 *	it under the terms of the GNU General Public License as published by
40 *	the Free Software Foundation, version 2.
41 */
42#include <linux/kernel.h>
43#include <linux/slab.h>
44#include <linux/string.h>
45#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/errno.h>
48#include <linux/in.h>
49#include <linux/sched.h>
50#include <linux/audit.h>
51#include <linux/mutex.h>
52#include <linux/selinux.h>
53#include <linux/flex_array.h>
54#include <linux/vmalloc.h>
55#include <net/netlabel.h>
56
57#include "flask.h"
58#include "avc.h"
59#include "avc_ss.h"
60#include "security.h"
61#include "context.h"
62#include "policydb.h"
63#include "sidtab.h"
64#include "services.h"
65#include "conditional.h"
66#include "mls.h"
67#include "objsec.h"
68#include "netlabel.h"
69#include "xfrm.h"
70#include "ebitmap.h"
71#include "audit.h"
72
73extern void selnl_notify_policyload(u32 seqno);
74
75int selinux_policycap_netpeer;
76int selinux_policycap_openperm;
77
78static DEFINE_RWLOCK(policy_rwlock);
79
80static struct sidtab sidtab;
81struct policydb policydb;
82int ss_initialized;
83
84/*
85 * The largest sequence number that has been used when
86 * providing an access decision to the access vector cache.
87 * The sequence number only changes when a policy change
88 * occurs.
89 */
90static u32 latest_granting;
91
92/* Forward declaration. */
93static int context_struct_to_string(struct context *context, char **scontext,
94				    u32 *scontext_len);
95
96static void context_struct_compute_av(struct context *scontext,
97				      struct context *tcontext,
98				      u16 tclass,
99				      struct av_decision *avd);
100
101struct selinux_mapping {
102	u16 value; /* policy value */
103	unsigned num_perms;
104	u32 perms[sizeof(u32) * 8];
105};
106
107static struct selinux_mapping *current_mapping;
108static u16 current_mapping_size;
109
110static int selinux_set_mapping(struct policydb *pol,
111			       struct security_class_mapping *map,
112			       struct selinux_mapping **out_map_p,
113			       u16 *out_map_size)
114{
115	struct selinux_mapping *out_map = NULL;
116	size_t size = sizeof(struct selinux_mapping);
117	u16 i, j;
118	unsigned k;
119	bool print_unknown_handle = false;
120
121	/* Find number of classes in the input mapping */
122	if (!map)
123		return -EINVAL;
124	i = 0;
125	while (map[i].name)
126		i++;
127
128	/* Allocate space for the class records, plus one for class zero */
129	out_map = kcalloc(++i, size, GFP_ATOMIC);
130	if (!out_map)
131		return -ENOMEM;
132
133	/* Store the raw class and permission values */
134	j = 0;
135	while (map[j].name) {
136		struct security_class_mapping *p_in = map + (j++);
137		struct selinux_mapping *p_out = out_map + j;
138
139		/* An empty class string skips ahead */
140		if (!strcmp(p_in->name, "")) {
141			p_out->num_perms = 0;
142			continue;
143		}
144
145		p_out->value = string_to_security_class(pol, p_in->name);
146		if (!p_out->value) {
147			printk(KERN_INFO
148			       "SELinux:  Class %s not defined in policy.\n",
149			       p_in->name);
150			if (pol->reject_unknown)
151				goto err;
152			p_out->num_perms = 0;
153			print_unknown_handle = true;
154			continue;
155		}
156
157		k = 0;
158		while (p_in->perms && p_in->perms[k]) {
159			/* An empty permission string skips ahead */
160			if (!*p_in->perms[k]) {
161				k++;
162				continue;
163			}
164			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165							    p_in->perms[k]);
166			if (!p_out->perms[k]) {
167				printk(KERN_INFO
168				       "SELinux:  Permission %s in class %s not defined in policy.\n",
169				       p_in->perms[k], p_in->name);
170				if (pol->reject_unknown)
171					goto err;
172				print_unknown_handle = true;
173			}
174
175			k++;
176		}
177		p_out->num_perms = k;
178	}
179
180	if (print_unknown_handle)
181		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182		       pol->allow_unknown ? "allowed" : "denied");
183
184	*out_map_p = out_map;
185	*out_map_size = i;
186	return 0;
187err:
188	kfree(out_map);
189	return -EINVAL;
190}
191
192/*
193 * Get real, policy values from mapped values
194 */
195
196static u16 unmap_class(u16 tclass)
197{
198	if (tclass < current_mapping_size)
199		return current_mapping[tclass].value;
200
201	return tclass;
202}
203
204static void map_decision(u16 tclass, struct av_decision *avd,
205			 int allow_unknown)
206{
207	if (tclass < current_mapping_size) {
208		unsigned i, n = current_mapping[tclass].num_perms;
209		u32 result;
210
211		for (i = 0, result = 0; i < n; i++) {
212			if (avd->allowed & current_mapping[tclass].perms[i])
213				result |= 1<<i;
214			if (allow_unknown && !current_mapping[tclass].perms[i])
215				result |= 1<<i;
216		}
217		avd->allowed = result;
218
219		for (i = 0, result = 0; i < n; i++)
220			if (avd->auditallow & current_mapping[tclass].perms[i])
221				result |= 1<<i;
222		avd->auditallow = result;
223
224		for (i = 0, result = 0; i < n; i++) {
225			if (avd->auditdeny & current_mapping[tclass].perms[i])
226				result |= 1<<i;
227			if (!allow_unknown && !current_mapping[tclass].perms[i])
228				result |= 1<<i;
229		}
230		/*
231		 * In case the kernel has a bug and requests a permission
232		 * between num_perms and the maximum permission number, we
233		 * should audit that denial
234		 */
235		for (; i < (sizeof(u32)*8); i++)
236			result |= 1<<i;
237		avd->auditdeny = result;
238	}
239}
240
241int security_mls_enabled(void)
242{
243	return policydb.mls_enabled;
244}
245
246/*
247 * Return the boolean value of a constraint expression
248 * when it is applied to the specified source and target
249 * security contexts.
250 *
251 * xcontext is a special beast...  It is used by the validatetrans rules
252 * only.  For these rules, scontext is the context before the transition,
253 * tcontext is the context after the transition, and xcontext is the context
254 * of the process performing the transition.  All other callers of
255 * constraint_expr_eval should pass in NULL for xcontext.
256 */
257static int constraint_expr_eval(struct context *scontext,
258				struct context *tcontext,
259				struct context *xcontext,
260				struct constraint_expr *cexpr)
261{
262	u32 val1, val2;
263	struct context *c;
264	struct role_datum *r1, *r2;
265	struct mls_level *l1, *l2;
266	struct constraint_expr *e;
267	int s[CEXPR_MAXDEPTH];
268	int sp = -1;
269
270	for (e = cexpr; e; e = e->next) {
271		switch (e->expr_type) {
272		case CEXPR_NOT:
273			BUG_ON(sp < 0);
274			s[sp] = !s[sp];
275			break;
276		case CEXPR_AND:
277			BUG_ON(sp < 1);
278			sp--;
279			s[sp] &= s[sp + 1];
280			break;
281		case CEXPR_OR:
282			BUG_ON(sp < 1);
283			sp--;
284			s[sp] |= s[sp + 1];
285			break;
286		case CEXPR_ATTR:
287			if (sp == (CEXPR_MAXDEPTH - 1))
288				return 0;
289			switch (e->attr) {
290			case CEXPR_USER:
291				val1 = scontext->user;
292				val2 = tcontext->user;
293				break;
294			case CEXPR_TYPE:
295				val1 = scontext->type;
296				val2 = tcontext->type;
297				break;
298			case CEXPR_ROLE:
299				val1 = scontext->role;
300				val2 = tcontext->role;
301				r1 = policydb.role_val_to_struct[val1 - 1];
302				r2 = policydb.role_val_to_struct[val2 - 1];
303				switch (e->op) {
304				case CEXPR_DOM:
305					s[++sp] = ebitmap_get_bit(&r1->dominates,
306								  val2 - 1);
307					continue;
308				case CEXPR_DOMBY:
309					s[++sp] = ebitmap_get_bit(&r2->dominates,
310								  val1 - 1);
311					continue;
312				case CEXPR_INCOMP:
313					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
314								    val2 - 1) &&
315						   !ebitmap_get_bit(&r2->dominates,
316								    val1 - 1));
317					continue;
318				default:
319					break;
320				}
321				break;
322			case CEXPR_L1L2:
323				l1 = &(scontext->range.level[0]);
324				l2 = &(tcontext->range.level[0]);
325				goto mls_ops;
326			case CEXPR_L1H2:
327				l1 = &(scontext->range.level[0]);
328				l2 = &(tcontext->range.level[1]);
329				goto mls_ops;
330			case CEXPR_H1L2:
331				l1 = &(scontext->range.level[1]);
332				l2 = &(tcontext->range.level[0]);
333				goto mls_ops;
334			case CEXPR_H1H2:
335				l1 = &(scontext->range.level[1]);
336				l2 = &(tcontext->range.level[1]);
337				goto mls_ops;
338			case CEXPR_L1H1:
339				l1 = &(scontext->range.level[0]);
340				l2 = &(scontext->range.level[1]);
341				goto mls_ops;
342			case CEXPR_L2H2:
343				l1 = &(tcontext->range.level[0]);
344				l2 = &(tcontext->range.level[1]);
345				goto mls_ops;
346mls_ops:
347			switch (e->op) {
348			case CEXPR_EQ:
349				s[++sp] = mls_level_eq(l1, l2);
350				continue;
351			case CEXPR_NEQ:
352				s[++sp] = !mls_level_eq(l1, l2);
353				continue;
354			case CEXPR_DOM:
355				s[++sp] = mls_level_dom(l1, l2);
356				continue;
357			case CEXPR_DOMBY:
358				s[++sp] = mls_level_dom(l2, l1);
359				continue;
360			case CEXPR_INCOMP:
361				s[++sp] = mls_level_incomp(l2, l1);
362				continue;
363			default:
364				BUG();
365				return 0;
366			}
367			break;
368			default:
369				BUG();
370				return 0;
371			}
372
373			switch (e->op) {
374			case CEXPR_EQ:
375				s[++sp] = (val1 == val2);
376				break;
377			case CEXPR_NEQ:
378				s[++sp] = (val1 != val2);
379				break;
380			default:
381				BUG();
382				return 0;
383			}
384			break;
385		case CEXPR_NAMES:
386			if (sp == (CEXPR_MAXDEPTH-1))
387				return 0;
388			c = scontext;
389			if (e->attr & CEXPR_TARGET)
390				c = tcontext;
391			else if (e->attr & CEXPR_XTARGET) {
392				c = xcontext;
393				if (!c) {
394					BUG();
395					return 0;
396				}
397			}
398			if (e->attr & CEXPR_USER)
399				val1 = c->user;
400			else if (e->attr & CEXPR_ROLE)
401				val1 = c->role;
402			else if (e->attr & CEXPR_TYPE)
403				val1 = c->type;
404			else {
405				BUG();
406				return 0;
407			}
408
409			switch (e->op) {
410			case CEXPR_EQ:
411				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
412				break;
413			case CEXPR_NEQ:
414				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
415				break;
416			default:
417				BUG();
418				return 0;
419			}
420			break;
421		default:
422			BUG();
423			return 0;
424		}
425	}
426
427	BUG_ON(sp != 0);
428	return s[0];
429}
430
431/*
432 * security_dump_masked_av - dumps masked permissions during
433 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
434 */
435static int dump_masked_av_helper(void *k, void *d, void *args)
436{
437	struct perm_datum *pdatum = d;
438	char **permission_names = args;
439
440	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
441
442	permission_names[pdatum->value - 1] = (char *)k;
443
444	return 0;
445}
446
447static void security_dump_masked_av(struct context *scontext,
448				    struct context *tcontext,
449				    u16 tclass,
450				    u32 permissions,
451				    const char *reason)
452{
453	struct common_datum *common_dat;
454	struct class_datum *tclass_dat;
455	struct audit_buffer *ab;
456	char *tclass_name;
457	char *scontext_name = NULL;
458	char *tcontext_name = NULL;
459	char *permission_names[32];
460	int index;
461	u32 length;
462	bool need_comma = false;
463
464	if (!permissions)
465		return;
466
467	tclass_name = policydb.p_class_val_to_name[tclass - 1];
468	tclass_dat = policydb.class_val_to_struct[tclass - 1];
469	common_dat = tclass_dat->comdatum;
470
471	/* init permission_names */
472	if (common_dat &&
473	    hashtab_map(common_dat->permissions.table,
474			dump_masked_av_helper, permission_names) < 0)
475		goto out;
476
477	if (hashtab_map(tclass_dat->permissions.table,
478			dump_masked_av_helper, permission_names) < 0)
479		goto out;
480
481	/* get scontext/tcontext in text form */
482	if (context_struct_to_string(scontext,
483				     &scontext_name, &length) < 0)
484		goto out;
485
486	if (context_struct_to_string(tcontext,
487				     &tcontext_name, &length) < 0)
488		goto out;
489
490	/* audit a message */
491	ab = audit_log_start(current->audit_context,
492			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
493	if (!ab)
494		goto out;
495
496	audit_log_format(ab, "op=security_compute_av reason=%s "
497			 "scontext=%s tcontext=%s tclass=%s perms=",
498			 reason, scontext_name, tcontext_name, tclass_name);
499
500	for (index = 0; index < 32; index++) {
501		u32 mask = (1 << index);
502
503		if ((mask & permissions) == 0)
504			continue;
505
506		audit_log_format(ab, "%s%s",
507				 need_comma ? "," : "",
508				 permission_names[index]
509				 ? permission_names[index] : "????");
510		need_comma = true;
511	}
512	audit_log_end(ab);
513out:
514	/* release scontext/tcontext */
515	kfree(tcontext_name);
516	kfree(scontext_name);
517
518	return;
519}
520
521/*
522 * security_boundary_permission - drops violated permissions
523 * on boundary constraint.
524 */
525static void type_attribute_bounds_av(struct context *scontext,
526				     struct context *tcontext,
527				     u16 tclass,
528				     struct av_decision *avd)
529{
530	struct context lo_scontext;
531	struct context lo_tcontext;
532	struct av_decision lo_avd;
533	struct type_datum *source
534		= policydb.type_val_to_struct[scontext->type - 1];
535	struct type_datum *target
536		= policydb.type_val_to_struct[tcontext->type - 1];
537	u32 masked = 0;
538
539	if (source->bounds) {
540		memset(&lo_avd, 0, sizeof(lo_avd));
541
542		memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
543		lo_scontext.type = source->bounds;
544
545		context_struct_compute_av(&lo_scontext,
546					  tcontext,
547					  tclass,
548					  &lo_avd);
549		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
550			return;		/* no masked permission */
551		masked = ~lo_avd.allowed & avd->allowed;
552	}
553
554	if (target->bounds) {
555		memset(&lo_avd, 0, sizeof(lo_avd));
556
557		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
558		lo_tcontext.type = target->bounds;
559
560		context_struct_compute_av(scontext,
561					  &lo_tcontext,
562					  tclass,
563					  &lo_avd);
564		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
565			return;		/* no masked permission */
566		masked = ~lo_avd.allowed & avd->allowed;
567	}
568
569	if (source->bounds && target->bounds) {
570		memset(&lo_avd, 0, sizeof(lo_avd));
571		/*
572		 * lo_scontext and lo_tcontext are already
573		 * set up.
574		 */
575
576		context_struct_compute_av(&lo_scontext,
577					  &lo_tcontext,
578					  tclass,
579					  &lo_avd);
580		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
581			return;		/* no masked permission */
582		masked = ~lo_avd.allowed & avd->allowed;
583	}
584
585	if (masked) {
586		/* mask violated permissions */
587		avd->allowed &= ~masked;
588
589		/* audit masked permissions */
590		security_dump_masked_av(scontext, tcontext,
591					tclass, masked, "bounds");
592	}
593}
594
595/*
596 * Compute access vectors based on a context structure pair for
597 * the permissions in a particular class.
598 */
599static void context_struct_compute_av(struct context *scontext,
600				      struct context *tcontext,
601				      u16 tclass,
602				      struct av_decision *avd)
603{
604	struct constraint_node *constraint;
605	struct role_allow *ra;
606	struct avtab_key avkey;
607	struct avtab_node *node;
608	struct class_datum *tclass_datum;
609	struct ebitmap *sattr, *tattr;
610	struct ebitmap_node *snode, *tnode;
611	unsigned int i, j;
612
613	avd->allowed = 0;
614	avd->auditallow = 0;
615	avd->auditdeny = 0xffffffff;
616
617	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
618		if (printk_ratelimit())
619			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
620		return;
621	}
622
623	tclass_datum = policydb.class_val_to_struct[tclass - 1];
624
625	/*
626	 * If a specific type enforcement rule was defined for
627	 * this permission check, then use it.
628	 */
629	avkey.target_class = tclass;
630	avkey.specified = AVTAB_AV;
631	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
632	BUG_ON(!sattr);
633	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
634	BUG_ON(!tattr);
635	ebitmap_for_each_positive_bit(sattr, snode, i) {
636		ebitmap_for_each_positive_bit(tattr, tnode, j) {
637			avkey.source_type = i + 1;
638			avkey.target_type = j + 1;
639			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
640			     node;
641			     node = avtab_search_node_next(node, avkey.specified)) {
642				if (node->key.specified == AVTAB_ALLOWED)
643					avd->allowed |= node->datum.data;
644				else if (node->key.specified == AVTAB_AUDITALLOW)
645					avd->auditallow |= node->datum.data;
646				else if (node->key.specified == AVTAB_AUDITDENY)
647					avd->auditdeny &= node->datum.data;
648			}
649
650			/* Check conditional av table for additional permissions */
651			cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
652
653		}
654	}
655
656	/*
657	 * Remove any permissions prohibited by a constraint (this includes
658	 * the MLS policy).
659	 */
660	constraint = tclass_datum->constraints;
661	while (constraint) {
662		if ((constraint->permissions & (avd->allowed)) &&
663		    !constraint_expr_eval(scontext, tcontext, NULL,
664					  constraint->expr)) {
665			avd->allowed &= ~(constraint->permissions);
666		}
667		constraint = constraint->next;
668	}
669
670	/*
671	 * If checking process transition permission and the
672	 * role is changing, then check the (current_role, new_role)
673	 * pair.
674	 */
675	if (tclass == policydb.process_class &&
676	    (avd->allowed & policydb.process_trans_perms) &&
677	    scontext->role != tcontext->role) {
678		for (ra = policydb.role_allow; ra; ra = ra->next) {
679			if (scontext->role == ra->role &&
680			    tcontext->role == ra->new_role)
681				break;
682		}
683		if (!ra)
684			avd->allowed &= ~policydb.process_trans_perms;
685	}
686
687	/*
688	 * If the given source and target types have boundary
689	 * constraint, lazy checks have to mask any violated
690	 * permission and notice it to userspace via audit.
691	 */
692	type_attribute_bounds_av(scontext, tcontext,
693				 tclass, avd);
694}
695
696static int security_validtrans_handle_fail(struct context *ocontext,
697					   struct context *ncontext,
698					   struct context *tcontext,
699					   u16 tclass)
700{
701	char *o = NULL, *n = NULL, *t = NULL;
702	u32 olen, nlen, tlen;
703
704	if (context_struct_to_string(ocontext, &o, &olen))
705		goto out;
706	if (context_struct_to_string(ncontext, &n, &nlen))
707		goto out;
708	if (context_struct_to_string(tcontext, &t, &tlen))
709		goto out;
710	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
711		  "security_validate_transition:  denied for"
712		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
713		  o, n, t, policydb.p_class_val_to_name[tclass-1]);
714out:
715	kfree(o);
716	kfree(n);
717	kfree(t);
718
719	if (!selinux_enforcing)
720		return 0;
721	return -EPERM;
722}
723
724int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
725				 u16 orig_tclass)
726{
727	struct context *ocontext;
728	struct context *ncontext;
729	struct context *tcontext;
730	struct class_datum *tclass_datum;
731	struct constraint_node *constraint;
732	u16 tclass;
733	int rc = 0;
734
735	if (!ss_initialized)
736		return 0;
737
738	read_lock(&policy_rwlock);
739
740	tclass = unmap_class(orig_tclass);
741
742	if (!tclass || tclass > policydb.p_classes.nprim) {
743		printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
744			__func__, tclass);
745		rc = -EINVAL;
746		goto out;
747	}
748	tclass_datum = policydb.class_val_to_struct[tclass - 1];
749
750	ocontext = sidtab_search(&sidtab, oldsid);
751	if (!ocontext) {
752		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
753			__func__, oldsid);
754		rc = -EINVAL;
755		goto out;
756	}
757
758	ncontext = sidtab_search(&sidtab, newsid);
759	if (!ncontext) {
760		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
761			__func__, newsid);
762		rc = -EINVAL;
763		goto out;
764	}
765
766	tcontext = sidtab_search(&sidtab, tasksid);
767	if (!tcontext) {
768		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
769			__func__, tasksid);
770		rc = -EINVAL;
771		goto out;
772	}
773
774	constraint = tclass_datum->validatetrans;
775	while (constraint) {
776		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
777					  constraint->expr)) {
778			rc = security_validtrans_handle_fail(ocontext, ncontext,
779							     tcontext, tclass);
780			goto out;
781		}
782		constraint = constraint->next;
783	}
784
785out:
786	read_unlock(&policy_rwlock);
787	return rc;
788}
789
790/*
791 * security_bounded_transition - check whether the given
792 * transition is directed to bounded, or not.
793 * It returns 0, if @newsid is bounded by @oldsid.
794 * Otherwise, it returns error code.
795 *
796 * @oldsid : current security identifier
797 * @newsid : destinated security identifier
798 */
799int security_bounded_transition(u32 old_sid, u32 new_sid)
800{
801	struct context *old_context, *new_context;
802	struct type_datum *type;
803	int index;
804	int rc;
805
806	read_lock(&policy_rwlock);
807
808	rc = -EINVAL;
809	old_context = sidtab_search(&sidtab, old_sid);
810	if (!old_context) {
811		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
812		       __func__, old_sid);
813		goto out;
814	}
815
816	rc = -EINVAL;
817	new_context = sidtab_search(&sidtab, new_sid);
818	if (!new_context) {
819		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
820		       __func__, new_sid);
821		goto out;
822	}
823
824	rc = 0;
825	/* type/domain unchanged */
826	if (old_context->type == new_context->type)
827		goto out;
828
829	index = new_context->type;
830	while (true) {
831		type = policydb.type_val_to_struct[index - 1];
832		BUG_ON(!type);
833
834		/* not bounded anymore */
835		rc = -EPERM;
836		if (!type->bounds)
837			break;
838
839		/* @newsid is bounded by @oldsid */
840		rc = 0;
841		if (type->bounds == old_context->type)
842			break;
843
844		index = type->bounds;
845	}
846
847	if (rc) {
848		char *old_name = NULL;
849		char *new_name = NULL;
850		u32 length;
851
852		if (!context_struct_to_string(old_context,
853					      &old_name, &length) &&
854		    !context_struct_to_string(new_context,
855					      &new_name, &length)) {
856			audit_log(current->audit_context,
857				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
858				  "op=security_bounded_transition "
859				  "result=denied "
860				  "oldcontext=%s newcontext=%s",
861				  old_name, new_name);
862		}
863		kfree(new_name);
864		kfree(old_name);
865	}
866out:
867	read_unlock(&policy_rwlock);
868
869	return rc;
870}
871
872static void avd_init(struct av_decision *avd)
873{
874	avd->allowed = 0;
875	avd->auditallow = 0;
876	avd->auditdeny = 0xffffffff;
877	avd->seqno = latest_granting;
878	avd->flags = 0;
879}
880
881
882/**
883 * security_compute_av - Compute access vector decisions.
884 * @ssid: source security identifier
885 * @tsid: target security identifier
886 * @tclass: target security class
887 * @avd: access vector decisions
888 *
889 * Compute a set of access vector decisions based on the
890 * SID pair (@ssid, @tsid) for the permissions in @tclass.
891 */
892void security_compute_av(u32 ssid,
893			 u32 tsid,
894			 u16 orig_tclass,
895			 struct av_decision *avd)
896{
897	u16 tclass;
898	struct context *scontext = NULL, *tcontext = NULL;
899
900	read_lock(&policy_rwlock);
901	avd_init(avd);
902	if (!ss_initialized)
903		goto allow;
904
905	scontext = sidtab_search(&sidtab, ssid);
906	if (!scontext) {
907		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
908		       __func__, ssid);
909		goto out;
910	}
911
912	/* permissive domain? */
913	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
914		avd->flags |= AVD_FLAGS_PERMISSIVE;
915
916	tcontext = sidtab_search(&sidtab, tsid);
917	if (!tcontext) {
918		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
919		       __func__, tsid);
920		goto out;
921	}
922
923	tclass = unmap_class(orig_tclass);
924	if (unlikely(orig_tclass && !tclass)) {
925		if (policydb.allow_unknown)
926			goto allow;
927		goto out;
928	}
929	context_struct_compute_av(scontext, tcontext, tclass, avd);
930	map_decision(orig_tclass, avd, policydb.allow_unknown);
931out:
932	read_unlock(&policy_rwlock);
933	return;
934allow:
935	avd->allowed = 0xffffffff;
936	goto out;
937}
938
939void security_compute_av_user(u32 ssid,
940			      u32 tsid,
941			      u16 tclass,
942			      struct av_decision *avd)
943{
944	struct context *scontext = NULL, *tcontext = NULL;
945
946	read_lock(&policy_rwlock);
947	avd_init(avd);
948	if (!ss_initialized)
949		goto allow;
950
951	scontext = sidtab_search(&sidtab, ssid);
952	if (!scontext) {
953		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
954		       __func__, ssid);
955		goto out;
956	}
957
958	/* permissive domain? */
959	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
960		avd->flags |= AVD_FLAGS_PERMISSIVE;
961
962	tcontext = sidtab_search(&sidtab, tsid);
963	if (!tcontext) {
964		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
965		       __func__, tsid);
966		goto out;
967	}
968
969	if (unlikely(!tclass)) {
970		if (policydb.allow_unknown)
971			goto allow;
972		goto out;
973	}
974
975	context_struct_compute_av(scontext, tcontext, tclass, avd);
976 out:
977	read_unlock(&policy_rwlock);
978	return;
979allow:
980	avd->allowed = 0xffffffff;
981	goto out;
982}
983
984/*
985 * Write the security context string representation of
986 * the context structure `context' into a dynamically
987 * allocated string of the correct size.  Set `*scontext'
988 * to point to this string and set `*scontext_len' to
989 * the length of the string.
990 */
991static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
992{
993	char *scontextp;
994
995	if (scontext)
996		*scontext = NULL;
997	*scontext_len = 0;
998
999	if (context->len) {
1000		*scontext_len = context->len;
1001		*scontext = kstrdup(context->str, GFP_ATOMIC);
1002		if (!(*scontext))
1003			return -ENOMEM;
1004		return 0;
1005	}
1006
1007	/* Compute the size of the context. */
1008	*scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
1009	*scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
1010	*scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
1011	*scontext_len += mls_compute_context_len(context);
1012
1013	if (!scontext)
1014		return 0;
1015
1016	/* Allocate space for the context; caller must free this space. */
1017	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1018	if (!scontextp)
1019		return -ENOMEM;
1020	*scontext = scontextp;
1021
1022	/*
1023	 * Copy the user name, role name and type name into the context.
1024	 */
1025	sprintf(scontextp, "%s:%s:%s",
1026		policydb.p_user_val_to_name[context->user - 1],
1027		policydb.p_role_val_to_name[context->role - 1],
1028		policydb.p_type_val_to_name[context->type - 1]);
1029	scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
1030		     1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
1031		     1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
1032
1033	mls_sid_to_context(context, &scontextp);
1034
1035	*scontextp = 0;
1036
1037	return 0;
1038}
1039
1040#include "initial_sid_to_string.h"
1041
1042const char *security_get_initial_sid_context(u32 sid)
1043{
1044	if (unlikely(sid > SECINITSID_NUM))
1045		return NULL;
1046	return initial_sid_to_string[sid];
1047}
1048
1049static int security_sid_to_context_core(u32 sid, char **scontext,
1050					u32 *scontext_len, int force)
1051{
1052	struct context *context;
1053	int rc = 0;
1054
1055	if (scontext)
1056		*scontext = NULL;
1057	*scontext_len  = 0;
1058
1059	if (!ss_initialized) {
1060		if (sid <= SECINITSID_NUM) {
1061			char *scontextp;
1062
1063			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1064			if (!scontext)
1065				goto out;
1066			scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1067			if (!scontextp) {
1068				rc = -ENOMEM;
1069				goto out;
1070			}
1071			strcpy(scontextp, initial_sid_to_string[sid]);
1072			*scontext = scontextp;
1073			goto out;
1074		}
1075		printk(KERN_ERR "SELinux: %s:  called before initial "
1076		       "load_policy on unknown SID %d\n", __func__, sid);
1077		rc = -EINVAL;
1078		goto out;
1079	}
1080	read_lock(&policy_rwlock);
1081	if (force)
1082		context = sidtab_search_force(&sidtab, sid);
1083	else
1084		context = sidtab_search(&sidtab, sid);
1085	if (!context) {
1086		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1087			__func__, sid);
1088		rc = -EINVAL;
1089		goto out_unlock;
1090	}
1091	rc = context_struct_to_string(context, scontext, scontext_len);
1092out_unlock:
1093	read_unlock(&policy_rwlock);
1094out:
1095	return rc;
1096
1097}
1098
1099/**
1100 * security_sid_to_context - Obtain a context for a given SID.
1101 * @sid: security identifier, SID
1102 * @scontext: security context
1103 * @scontext_len: length in bytes
1104 *
1105 * Write the string representation of the context associated with @sid
1106 * into a dynamically allocated string of the correct size.  Set @scontext
1107 * to point to this string and set @scontext_len to the length of the string.
1108 */
1109int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1110{
1111	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1112}
1113
1114int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1115{
1116	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1117}
1118
1119/*
1120 * Caveat:  Mutates scontext.
1121 */
1122static int string_to_context_struct(struct policydb *pol,
1123				    struct sidtab *sidtabp,
1124				    char *scontext,
1125				    u32 scontext_len,
1126				    struct context *ctx,
1127				    u32 def_sid)
1128{
1129	struct role_datum *role;
1130	struct type_datum *typdatum;
1131	struct user_datum *usrdatum;
1132	char *scontextp, *p, oldc;
1133	int rc = 0;
1134
1135	context_init(ctx);
1136
1137	/* Parse the security context. */
1138
1139	rc = -EINVAL;
1140	scontextp = (char *) scontext;
1141
1142	/* Extract the user. */
1143	p = scontextp;
1144	while (*p && *p != ':')
1145		p++;
1146
1147	if (*p == 0)
1148		goto out;
1149
1150	*p++ = 0;
1151
1152	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1153	if (!usrdatum)
1154		goto out;
1155
1156	ctx->user = usrdatum->value;
1157
1158	/* Extract role. */
1159	scontextp = p;
1160	while (*p && *p != ':')
1161		p++;
1162
1163	if (*p == 0)
1164		goto out;
1165
1166	*p++ = 0;
1167
1168	role = hashtab_search(pol->p_roles.table, scontextp);
1169	if (!role)
1170		goto out;
1171	ctx->role = role->value;
1172
1173	/* Extract type. */
1174	scontextp = p;
1175	while (*p && *p != ':')
1176		p++;
1177	oldc = *p;
1178	*p++ = 0;
1179
1180	typdatum = hashtab_search(pol->p_types.table, scontextp);
1181	if (!typdatum || typdatum->attribute)
1182		goto out;
1183
1184	ctx->type = typdatum->value;
1185
1186	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1187	if (rc)
1188		goto out;
1189
1190	rc = -EINVAL;
1191	if ((p - scontext) < scontext_len)
1192		goto out;
1193
1194	/* Check the validity of the new context. */
1195	if (!policydb_context_isvalid(pol, ctx))
1196		goto out;
1197	rc = 0;
1198out:
1199	if (rc)
1200		context_destroy(ctx);
1201	return rc;
1202}
1203
1204static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1205					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1206					int force)
1207{
1208	char *scontext2, *str = NULL;
1209	struct context context;
1210	int rc = 0;
1211
1212	if (!ss_initialized) {
1213		int i;
1214
1215		for (i = 1; i < SECINITSID_NUM; i++) {
1216			if (!strcmp(initial_sid_to_string[i], scontext)) {
1217				*sid = i;
1218				return 0;
1219			}
1220		}
1221		*sid = SECINITSID_KERNEL;
1222		return 0;
1223	}
1224	*sid = SECSID_NULL;
1225
1226	/* Copy the string so that we can modify the copy as we parse it. */
1227	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1228	if (!scontext2)
1229		return -ENOMEM;
1230	memcpy(scontext2, scontext, scontext_len);
1231	scontext2[scontext_len] = 0;
1232
1233	if (force) {
1234		/* Save another copy for storing in uninterpreted form */
1235		rc = -ENOMEM;
1236		str = kstrdup(scontext2, gfp_flags);
1237		if (!str)
1238			goto out;
1239	}
1240
1241	read_lock(&policy_rwlock);
1242	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1243				      scontext_len, &context, def_sid);
1244	if (rc == -EINVAL && force) {
1245		context.str = str;
1246		context.len = scontext_len;
1247		str = NULL;
1248	} else if (rc)
1249		goto out_unlock;
1250	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1251	context_destroy(&context);
1252out_unlock:
1253	read_unlock(&policy_rwlock);
1254out:
1255	kfree(scontext2);
1256	kfree(str);
1257	return rc;
1258}
1259
1260/**
1261 * security_context_to_sid - Obtain a SID for a given security context.
1262 * @scontext: security context
1263 * @scontext_len: length in bytes
1264 * @sid: security identifier, SID
1265 *
1266 * Obtains a SID associated with the security context that
1267 * has the string representation specified by @scontext.
1268 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1269 * memory is available, or 0 on success.
1270 */
1271int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1272{
1273	return security_context_to_sid_core(scontext, scontext_len,
1274					    sid, SECSID_NULL, GFP_KERNEL, 0);
1275}
1276
1277/**
1278 * security_context_to_sid_default - Obtain a SID for a given security context,
1279 * falling back to specified default if needed.
1280 *
1281 * @scontext: security context
1282 * @scontext_len: length in bytes
1283 * @sid: security identifier, SID
1284 * @def_sid: default SID to assign on error
1285 *
1286 * Obtains a SID associated with the security context that
1287 * has the string representation specified by @scontext.
1288 * The default SID is passed to the MLS layer to be used to allow
1289 * kernel labeling of the MLS field if the MLS field is not present
1290 * (for upgrading to MLS without full relabel).
1291 * Implicitly forces adding of the context even if it cannot be mapped yet.
1292 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1293 * memory is available, or 0 on success.
1294 */
1295int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1296				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1297{
1298	return security_context_to_sid_core(scontext, scontext_len,
1299					    sid, def_sid, gfp_flags, 1);
1300}
1301
1302int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1303				  u32 *sid)
1304{
1305	return security_context_to_sid_core(scontext, scontext_len,
1306					    sid, SECSID_NULL, GFP_KERNEL, 1);
1307}
1308
1309static int compute_sid_handle_invalid_context(
1310	struct context *scontext,
1311	struct context *tcontext,
1312	u16 tclass,
1313	struct context *newcontext)
1314{
1315	char *s = NULL, *t = NULL, *n = NULL;
1316	u32 slen, tlen, nlen;
1317
1318	if (context_struct_to_string(scontext, &s, &slen))
1319		goto out;
1320	if (context_struct_to_string(tcontext, &t, &tlen))
1321		goto out;
1322	if (context_struct_to_string(newcontext, &n, &nlen))
1323		goto out;
1324	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1325		  "security_compute_sid:  invalid context %s"
1326		  " for scontext=%s"
1327		  " tcontext=%s"
1328		  " tclass=%s",
1329		  n, s, t, policydb.p_class_val_to_name[tclass-1]);
1330out:
1331	kfree(s);
1332	kfree(t);
1333	kfree(n);
1334	if (!selinux_enforcing)
1335		return 0;
1336	return -EACCES;
1337}
1338
1339static int security_compute_sid(u32 ssid,
1340				u32 tsid,
1341				u16 orig_tclass,
1342				u32 specified,
1343				u32 *out_sid,
1344				bool kern)
1345{
1346	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1347	struct role_trans *roletr = NULL;
1348	struct avtab_key avkey;
1349	struct avtab_datum *avdatum;
1350	struct avtab_node *node;
1351	u16 tclass;
1352	int rc = 0;
1353
1354	if (!ss_initialized) {
1355		switch (orig_tclass) {
1356		case SECCLASS_PROCESS: /* kernel value */
1357			*out_sid = ssid;
1358			break;
1359		default:
1360			*out_sid = tsid;
1361			break;
1362		}
1363		goto out;
1364	}
1365
1366	context_init(&newcontext);
1367
1368	read_lock(&policy_rwlock);
1369
1370	if (kern)
1371		tclass = unmap_class(orig_tclass);
1372	else
1373		tclass = orig_tclass;
1374
1375	scontext = sidtab_search(&sidtab, ssid);
1376	if (!scontext) {
1377		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1378		       __func__, ssid);
1379		rc = -EINVAL;
1380		goto out_unlock;
1381	}
1382	tcontext = sidtab_search(&sidtab, tsid);
1383	if (!tcontext) {
1384		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1385		       __func__, tsid);
1386		rc = -EINVAL;
1387		goto out_unlock;
1388	}
1389
1390	/* Set the user identity. */
1391	switch (specified) {
1392	case AVTAB_TRANSITION:
1393	case AVTAB_CHANGE:
1394		/* Use the process user identity. */
1395		newcontext.user = scontext->user;
1396		break;
1397	case AVTAB_MEMBER:
1398		/* Use the related object owner. */
1399		newcontext.user = tcontext->user;
1400		break;
1401	}
1402
1403	/* Set the role and type to default values. */
1404	if (tclass == policydb.process_class) {
1405		/* Use the current role and type of process. */
1406		newcontext.role = scontext->role;
1407		newcontext.type = scontext->type;
1408	} else {
1409		/* Use the well-defined object role. */
1410		newcontext.role = OBJECT_R_VAL;
1411		/* Use the type of the related object. */
1412		newcontext.type = tcontext->type;
1413	}
1414
1415	/* Look for a type transition/member/change rule. */
1416	avkey.source_type = scontext->type;
1417	avkey.target_type = tcontext->type;
1418	avkey.target_class = tclass;
1419	avkey.specified = specified;
1420	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1421
1422	/* If no permanent rule, also check for enabled conditional rules */
1423	if (!avdatum) {
1424		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1425		for (; node; node = avtab_search_node_next(node, specified)) {
1426			if (node->key.specified & AVTAB_ENABLED) {
1427				avdatum = &node->datum;
1428				break;
1429			}
1430		}
1431	}
1432
1433	if (avdatum) {
1434		/* Use the type from the type transition/member/change rule. */
1435		newcontext.type = avdatum->data;
1436	}
1437
1438	/* Check for class-specific changes. */
1439	if  (tclass == policydb.process_class) {
1440		if (specified & AVTAB_TRANSITION) {
1441			/* Look for a role transition rule. */
1442			for (roletr = policydb.role_tr; roletr;
1443			     roletr = roletr->next) {
1444				if (roletr->role == scontext->role &&
1445				    roletr->type == tcontext->type) {
1446					/* Use the role transition rule. */
1447					newcontext.role = roletr->new_role;
1448					break;
1449				}
1450			}
1451		}
1452	}
1453
1454	/* Set the MLS attributes.
1455	   This is done last because it may allocate memory. */
1456	rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1457	if (rc)
1458		goto out_unlock;
1459
1460	/* Check the validity of the context. */
1461	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1462		rc = compute_sid_handle_invalid_context(scontext,
1463							tcontext,
1464							tclass,
1465							&newcontext);
1466		if (rc)
1467			goto out_unlock;
1468	}
1469	/* Obtain the sid for the context. */
1470	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1471out_unlock:
1472	read_unlock(&policy_rwlock);
1473	context_destroy(&newcontext);
1474out:
1475	return rc;
1476}
1477
1478/**
1479 * security_transition_sid - Compute the SID for a new subject/object.
1480 * @ssid: source security identifier
1481 * @tsid: target security identifier
1482 * @tclass: target security class
1483 * @out_sid: security identifier for new subject/object
1484 *
1485 * Compute a SID to use for labeling a new subject or object in the
1486 * class @tclass based on a SID pair (@ssid, @tsid).
1487 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1488 * if insufficient memory is available, or %0 if the new SID was
1489 * computed successfully.
1490 */
1491int security_transition_sid(u32 ssid,
1492			    u32 tsid,
1493			    u16 tclass,
1494			    u32 *out_sid)
1495{
1496	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1497				    out_sid, true);
1498}
1499
1500int security_transition_sid_user(u32 ssid,
1501				 u32 tsid,
1502				 u16 tclass,
1503				 u32 *out_sid)
1504{
1505	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1506				    out_sid, false);
1507}
1508
1509/**
1510 * security_member_sid - Compute the SID for member selection.
1511 * @ssid: source security identifier
1512 * @tsid: target security identifier
1513 * @tclass: target security class
1514 * @out_sid: security identifier for selected member
1515 *
1516 * Compute a SID to use when selecting a member of a polyinstantiated
1517 * object of class @tclass based on a SID pair (@ssid, @tsid).
1518 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1519 * if insufficient memory is available, or %0 if the SID was
1520 * computed successfully.
1521 */
1522int security_member_sid(u32 ssid,
1523			u32 tsid,
1524			u16 tclass,
1525			u32 *out_sid)
1526{
1527	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid,
1528				    false);
1529}
1530
1531/**
1532 * security_change_sid - Compute the SID for object relabeling.
1533 * @ssid: source security identifier
1534 * @tsid: target security identifier
1535 * @tclass: target security class
1536 * @out_sid: security identifier for selected member
1537 *
1538 * Compute a SID to use for relabeling an object of class @tclass
1539 * based on a SID pair (@ssid, @tsid).
1540 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1541 * if insufficient memory is available, or %0 if the SID was
1542 * computed successfully.
1543 */
1544int security_change_sid(u32 ssid,
1545			u32 tsid,
1546			u16 tclass,
1547			u32 *out_sid)
1548{
1549	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid,
1550				    false);
1551}
1552
1553/* Clone the SID into the new SID table. */
1554static int clone_sid(u32 sid,
1555		     struct context *context,
1556		     void *arg)
1557{
1558	struct sidtab *s = arg;
1559
1560	if (sid > SECINITSID_NUM)
1561		return sidtab_insert(s, sid, context);
1562	else
1563		return 0;
1564}
1565
1566static inline int convert_context_handle_invalid_context(struct context *context)
1567{
1568	char *s;
1569	u32 len;
1570
1571	if (selinux_enforcing)
1572		return -EINVAL;
1573
1574	if (!context_struct_to_string(context, &s, &len)) {
1575		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1576		kfree(s);
1577	}
1578	return 0;
1579}
1580
1581struct convert_context_args {
1582	struct policydb *oldp;
1583	struct policydb *newp;
1584};
1585
1586/*
1587 * Convert the values in the security context
1588 * structure `c' from the values specified
1589 * in the policy `p->oldp' to the values specified
1590 * in the policy `p->newp'.  Verify that the
1591 * context is valid under the new policy.
1592 */
1593static int convert_context(u32 key,
1594			   struct context *c,
1595			   void *p)
1596{
1597	struct convert_context_args *args;
1598	struct context oldc;
1599	struct ocontext *oc;
1600	struct mls_range *range;
1601	struct role_datum *role;
1602	struct type_datum *typdatum;
1603	struct user_datum *usrdatum;
1604	char *s;
1605	u32 len;
1606	int rc = 0;
1607
1608	if (key <= SECINITSID_NUM)
1609		goto out;
1610
1611	args = p;
1612
1613	if (c->str) {
1614		struct context ctx;
1615
1616		rc = -ENOMEM;
1617		s = kstrdup(c->str, GFP_KERNEL);
1618		if (!s)
1619			goto out;
1620
1621		rc = string_to_context_struct(args->newp, NULL, s,
1622					      c->len, &ctx, SECSID_NULL);
1623		kfree(s);
1624		if (!rc) {
1625			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1626			       c->str);
1627			/* Replace string with mapped representation. */
1628			kfree(c->str);
1629			memcpy(c, &ctx, sizeof(*c));
1630			goto out;
1631		} else if (rc == -EINVAL) {
1632			/* Retain string representation for later mapping. */
1633			rc = 0;
1634			goto out;
1635		} else {
1636			/* Other error condition, e.g. ENOMEM. */
1637			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1638			       c->str, -rc);
1639			goto out;
1640		}
1641	}
1642
1643	rc = context_cpy(&oldc, c);
1644	if (rc)
1645		goto out;
1646
1647	/* Convert the user. */
1648	rc = -EINVAL;
1649	usrdatum = hashtab_search(args->newp->p_users.table,
1650				  args->oldp->p_user_val_to_name[c->user - 1]);
1651	if (!usrdatum)
1652		goto bad;
1653	c->user = usrdatum->value;
1654
1655	/* Convert the role. */
1656	rc = -EINVAL;
1657	role = hashtab_search(args->newp->p_roles.table,
1658			      args->oldp->p_role_val_to_name[c->role - 1]);
1659	if (!role)
1660		goto bad;
1661	c->role = role->value;
1662
1663	/* Convert the type. */
1664	rc = -EINVAL;
1665	typdatum = hashtab_search(args->newp->p_types.table,
1666				  args->oldp->p_type_val_to_name[c->type - 1]);
1667	if (!typdatum)
1668		goto bad;
1669	c->type = typdatum->value;
1670
1671	/* Convert the MLS fields if dealing with MLS policies */
1672	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1673		rc = mls_convert_context(args->oldp, args->newp, c);
1674		if (rc)
1675			goto bad;
1676	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1677		/*
1678		 * Switching between MLS and non-MLS policy:
1679		 * free any storage used by the MLS fields in the
1680		 * context for all existing entries in the sidtab.
1681		 */
1682		mls_context_destroy(c);
1683	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1684		/*
1685		 * Switching between non-MLS and MLS policy:
1686		 * ensure that the MLS fields of the context for all
1687		 * existing entries in the sidtab are filled in with a
1688		 * suitable default value, likely taken from one of the
1689		 * initial SIDs.
1690		 */
1691		oc = args->newp->ocontexts[OCON_ISID];
1692		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1693			oc = oc->next;
1694		rc = -EINVAL;
1695		if (!oc) {
1696			printk(KERN_ERR "SELinux:  unable to look up"
1697				" the initial SIDs list\n");
1698			goto bad;
1699		}
1700		range = &oc->context[0].range;
1701		rc = mls_range_set(c, range);
1702		if (rc)
1703			goto bad;
1704	}
1705
1706	/* Check the validity of the new context. */
1707	if (!policydb_context_isvalid(args->newp, c)) {
1708		rc = convert_context_handle_invalid_context(&oldc);
1709		if (rc)
1710			goto bad;
1711	}
1712
1713	context_destroy(&oldc);
1714
1715	rc = 0;
1716out:
1717	return rc;
1718bad:
1719	/* Map old representation to string and save it. */
1720	rc = context_struct_to_string(&oldc, &s, &len);
1721	if (rc)
1722		return rc;
1723	context_destroy(&oldc);
1724	context_destroy(c);
1725	c->str = s;
1726	c->len = len;
1727	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1728	       c->str);
1729	rc = 0;
1730	goto out;
1731}
1732
1733static void security_load_policycaps(void)
1734{
1735	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1736						  POLICYDB_CAPABILITY_NETPEER);
1737	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1738						  POLICYDB_CAPABILITY_OPENPERM);
1739}
1740
1741extern void selinux_complete_init(void);
1742static int security_preserve_bools(struct policydb *p);
1743
1744/**
1745 * security_load_policy - Load a security policy configuration.
1746 * @data: binary policy data
1747 * @len: length of data in bytes
1748 *
1749 * Load a new set of security policy configuration data,
1750 * validate it and convert the SID table as necessary.
1751 * This function will flush the access vector cache after
1752 * loading the new policy.
1753 */
1754int security_load_policy(void *data, size_t len)
1755{
1756	struct policydb oldpolicydb, newpolicydb;
1757	struct sidtab oldsidtab, newsidtab;
1758	struct selinux_mapping *oldmap, *map = NULL;
1759	struct convert_context_args args;
1760	u32 seqno;
1761	u16 map_size;
1762	int rc = 0;
1763	struct policy_file file = { data, len }, *fp = &file;
1764
1765	if (!ss_initialized) {
1766		avtab_cache_init();
1767		rc = policydb_read(&policydb, fp);
1768		if (rc) {
1769			avtab_cache_destroy();
1770			return rc;
1771		}
1772
1773		policydb.len = len;
1774		rc = selinux_set_mapping(&policydb, secclass_map,
1775					 &current_mapping,
1776					 &current_mapping_size);
1777		if (rc) {
1778			policydb_destroy(&policydb);
1779			avtab_cache_destroy();
1780			return rc;
1781		}
1782
1783		rc = policydb_load_isids(&policydb, &sidtab);
1784		if (rc) {
1785			policydb_destroy(&policydb);
1786			avtab_cache_destroy();
1787			return rc;
1788		}
1789
1790		security_load_policycaps();
1791		ss_initialized = 1;
1792		seqno = ++latest_granting;
1793		selinux_complete_init();
1794		avc_ss_reset(seqno);
1795		selnl_notify_policyload(seqno);
1796		selinux_status_update_policyload(seqno);
1797		selinux_netlbl_cache_invalidate();
1798		selinux_xfrm_notify_policyload();
1799		return 0;
1800	}
1801
1802#if 0
1803	sidtab_hash_eval(&sidtab, "sids");
1804#endif
1805
1806	rc = policydb_read(&newpolicydb, fp);
1807	if (rc)
1808		return rc;
1809
1810	newpolicydb.len = len;
1811	/* If switching between different policy types, log MLS status */
1812	if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1813		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1814	else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1815		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1816
1817	rc = policydb_load_isids(&newpolicydb, &newsidtab);
1818	if (rc) {
1819		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1820		policydb_destroy(&newpolicydb);
1821		return rc;
1822	}
1823
1824	rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1825	if (rc)
1826		goto err;
1827
1828	rc = security_preserve_bools(&newpolicydb);
1829	if (rc) {
1830		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1831		goto err;
1832	}
1833
1834	/* Clone the SID table. */
1835	sidtab_shutdown(&sidtab);
1836
1837	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1838	if (rc)
1839		goto err;
1840
1841	/*
1842	 * Convert the internal representations of contexts
1843	 * in the new SID table.
1844	 */
1845	args.oldp = &policydb;
1846	args.newp = &newpolicydb;
1847	rc = sidtab_map(&newsidtab, convert_context, &args);
1848	if (rc) {
1849		printk(KERN_ERR "SELinux:  unable to convert the internal"
1850			" representation of contexts in the new SID"
1851			" table\n");
1852		goto err;
1853	}
1854
1855	/* Save the old policydb and SID table to free later. */
1856	memcpy(&oldpolicydb, &policydb, sizeof policydb);
1857	sidtab_set(&oldsidtab, &sidtab);
1858
1859	/* Install the new policydb and SID table. */
1860	write_lock_irq(&policy_rwlock);
1861	memcpy(&policydb, &newpolicydb, sizeof policydb);
1862	sidtab_set(&sidtab, &newsidtab);
1863	security_load_policycaps();
1864	oldmap = current_mapping;
1865	current_mapping = map;
1866	current_mapping_size = map_size;
1867	seqno = ++latest_granting;
1868	write_unlock_irq(&policy_rwlock);
1869
1870	/* Free the old policydb and SID table. */
1871	policydb_destroy(&oldpolicydb);
1872	sidtab_destroy(&oldsidtab);
1873	kfree(oldmap);
1874
1875	avc_ss_reset(seqno);
1876	selnl_notify_policyload(seqno);
1877	selinux_status_update_policyload(seqno);
1878	selinux_netlbl_cache_invalidate();
1879	selinux_xfrm_notify_policyload();
1880
1881	return 0;
1882
1883err:
1884	kfree(map);
1885	sidtab_destroy(&newsidtab);
1886	policydb_destroy(&newpolicydb);
1887	return rc;
1888
1889}
1890
1891size_t security_policydb_len(void)
1892{
1893	size_t len;
1894
1895	read_lock(&policy_rwlock);
1896	len = policydb.len;
1897	read_unlock(&policy_rwlock);
1898
1899	return len;
1900}
1901
1902/**
1903 * security_port_sid - Obtain the SID for a port.
1904 * @protocol: protocol number
1905 * @port: port number
1906 * @out_sid: security identifier
1907 */
1908int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1909{
1910	struct ocontext *c;
1911	int rc = 0;
1912
1913	read_lock(&policy_rwlock);
1914
1915	c = policydb.ocontexts[OCON_PORT];
1916	while (c) {
1917		if (c->u.port.protocol == protocol &&
1918		    c->u.port.low_port <= port &&
1919		    c->u.port.high_port >= port)
1920			break;
1921		c = c->next;
1922	}
1923
1924	if (c) {
1925		if (!c->sid[0]) {
1926			rc = sidtab_context_to_sid(&sidtab,
1927						   &c->context[0],
1928						   &c->sid[0]);
1929			if (rc)
1930				goto out;
1931		}
1932		*out_sid = c->sid[0];
1933	} else {
1934		*out_sid = SECINITSID_PORT;
1935	}
1936
1937out:
1938	read_unlock(&policy_rwlock);
1939	return rc;
1940}
1941
1942/**
1943 * security_netif_sid - Obtain the SID for a network interface.
1944 * @name: interface name
1945 * @if_sid: interface SID
1946 */
1947int security_netif_sid(char *name, u32 *if_sid)
1948{
1949	int rc = 0;
1950	struct ocontext *c;
1951
1952	read_lock(&policy_rwlock);
1953
1954	c = policydb.ocontexts[OCON_NETIF];
1955	while (c) {
1956		if (strcmp(name, c->u.name) == 0)
1957			break;
1958		c = c->next;
1959	}
1960
1961	if (c) {
1962		if (!c->sid[0] || !c->sid[1]) {
1963			rc = sidtab_context_to_sid(&sidtab,
1964						  &c->context[0],
1965						  &c->sid[0]);
1966			if (rc)
1967				goto out;
1968			rc = sidtab_context_to_sid(&sidtab,
1969						   &c->context[1],
1970						   &c->sid[1]);
1971			if (rc)
1972				goto out;
1973		}
1974		*if_sid = c->sid[0];
1975	} else
1976		*if_sid = SECINITSID_NETIF;
1977
1978out:
1979	read_unlock(&policy_rwlock);
1980	return rc;
1981}
1982
1983static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1984{
1985	int i, fail = 0;
1986
1987	for (i = 0; i < 4; i++)
1988		if (addr[i] != (input[i] & mask[i])) {
1989			fail = 1;
1990			break;
1991		}
1992
1993	return !fail;
1994}
1995
1996/**
1997 * security_node_sid - Obtain the SID for a node (host).
1998 * @domain: communication domain aka address family
1999 * @addrp: address
2000 * @addrlen: address length in bytes
2001 * @out_sid: security identifier
2002 */
2003int security_node_sid(u16 domain,
2004		      void *addrp,
2005		      u32 addrlen,
2006		      u32 *out_sid)
2007{
2008	int rc;
2009	struct ocontext *c;
2010
2011	read_lock(&policy_rwlock);
2012
2013	switch (domain) {
2014	case AF_INET: {
2015		u32 addr;
2016
2017		rc = -EINVAL;
2018		if (addrlen != sizeof(u32))
2019			goto out;
2020
2021		addr = *((u32 *)addrp);
2022
2023		c = policydb.ocontexts[OCON_NODE];
2024		while (c) {
2025			if (c->u.node.addr == (addr & c->u.node.mask))
2026				break;
2027			c = c->next;
2028		}
2029		break;
2030	}
2031
2032	case AF_INET6:
2033		rc = -EINVAL;
2034		if (addrlen != sizeof(u64) * 2)
2035			goto out;
2036		c = policydb.ocontexts[OCON_NODE6];
2037		while (c) {
2038			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2039						c->u.node6.mask))
2040				break;
2041			c = c->next;
2042		}
2043		break;
2044
2045	default:
2046		rc = 0;
2047		*out_sid = SECINITSID_NODE;
2048		goto out;
2049	}
2050
2051	if (c) {
2052		if (!c->sid[0]) {
2053			rc = sidtab_context_to_sid(&sidtab,
2054						   &c->context[0],
2055						   &c->sid[0]);
2056			if (rc)
2057				goto out;
2058		}
2059		*out_sid = c->sid[0];
2060	} else {
2061		*out_sid = SECINITSID_NODE;
2062	}
2063
2064	rc = 0;
2065out:
2066	read_unlock(&policy_rwlock);
2067	return rc;
2068}
2069
2070#define SIDS_NEL 25
2071
2072/**
2073 * security_get_user_sids - Obtain reachable SIDs for a user.
2074 * @fromsid: starting SID
2075 * @username: username
2076 * @sids: array of reachable SIDs for user
2077 * @nel: number of elements in @sids
2078 *
2079 * Generate the set of SIDs for legal security contexts
2080 * for a given user that can be reached by @fromsid.
2081 * Set *@sids to point to a dynamically allocated
2082 * array containing the set of SIDs.  Set *@nel to the
2083 * number of elements in the array.
2084 */
2085
2086int security_get_user_sids(u32 fromsid,
2087			   char *username,
2088			   u32 **sids,
2089			   u32 *nel)
2090{
2091	struct context *fromcon, usercon;
2092	u32 *mysids = NULL, *mysids2, sid;
2093	u32 mynel = 0, maxnel = SIDS_NEL;
2094	struct user_datum *user;
2095	struct role_datum *role;
2096	struct ebitmap_node *rnode, *tnode;
2097	int rc = 0, i, j;
2098
2099	*sids = NULL;
2100	*nel = 0;
2101
2102	if (!ss_initialized)
2103		goto out;
2104
2105	read_lock(&policy_rwlock);
2106
2107	context_init(&usercon);
2108
2109	rc = -EINVAL;
2110	fromcon = sidtab_search(&sidtab, fromsid);
2111	if (!fromcon)
2112		goto out_unlock;
2113
2114	rc = -EINVAL;
2115	user = hashtab_search(policydb.p_users.table, username);
2116	if (!user)
2117		goto out_unlock;
2118
2119	usercon.user = user->value;
2120
2121	rc = -ENOMEM;
2122	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2123	if (!mysids)
2124		goto out_unlock;
2125
2126	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2127		role = policydb.role_val_to_struct[i];
2128		usercon.role = i + 1;
2129		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2130			usercon.type = j + 1;
2131
2132			if (mls_setup_user_range(fromcon, user, &usercon))
2133				continue;
2134
2135			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2136			if (rc)
2137				goto out_unlock;
2138			if (mynel < maxnel) {
2139				mysids[mynel++] = sid;
2140			} else {
2141				rc = -ENOMEM;
2142				maxnel += SIDS_NEL;
2143				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2144				if (!mysids2)
2145					goto out_unlock;
2146				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2147				kfree(mysids);
2148				mysids = mysids2;
2149				mysids[mynel++] = sid;
2150			}
2151		}
2152	}
2153	rc = 0;
2154out_unlock:
2155	read_unlock(&policy_rwlock);
2156	if (rc || !mynel) {
2157		kfree(mysids);
2158		goto out;
2159	}
2160
2161	rc = -ENOMEM;
2162	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2163	if (!mysids2) {
2164		kfree(mysids);
2165		goto out;
2166	}
2167	for (i = 0, j = 0; i < mynel; i++) {
2168		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2169					  SECCLASS_PROCESS, /* kernel value */
2170					  PROCESS__TRANSITION, AVC_STRICT,
2171					  NULL);
2172		if (!rc)
2173			mysids2[j++] = mysids[i];
2174		cond_resched();
2175	}
2176	rc = 0;
2177	kfree(mysids);
2178	*sids = mysids2;
2179	*nel = j;
2180out:
2181	return rc;
2182}
2183
2184/**
2185 * security_genfs_sid - Obtain a SID for a file in a filesystem
2186 * @fstype: filesystem type
2187 * @path: path from root of mount
2188 * @sclass: file security class
2189 * @sid: SID for path
2190 *
2191 * Obtain a SID to use for a file in a filesystem that
2192 * cannot support xattr or use a fixed labeling behavior like
2193 * transition SIDs or task SIDs.
2194 */
2195int security_genfs_sid(const char *fstype,
2196		       char *path,
2197		       u16 orig_sclass,
2198		       u32 *sid)
2199{
2200	int len;
2201	u16 sclass;
2202	struct genfs *genfs;
2203	struct ocontext *c;
2204	int rc, cmp = 0;
2205
2206	while (path[0] == '/' && path[1] == '/')
2207		path++;
2208
2209	read_lock(&policy_rwlock);
2210
2211	sclass = unmap_class(orig_sclass);
2212	*sid = SECINITSID_UNLABELED;
2213
2214	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2215		cmp = strcmp(fstype, genfs->fstype);
2216		if (cmp <= 0)
2217			break;
2218	}
2219
2220	rc = -ENOENT;
2221	if (!genfs || cmp)
2222		goto out;
2223
2224	for (c = genfs->head; c; c = c->next) {
2225		len = strlen(c->u.name);
2226		if ((!c->v.sclass || sclass == c->v.sclass) &&
2227		    (strncmp(c->u.name, path, len) == 0))
2228			break;
2229	}
2230
2231	rc = -ENOENT;
2232	if (!c)
2233		goto out;
2234
2235	if (!c->sid[0]) {
2236		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2237		if (rc)
2238			goto out;
2239	}
2240
2241	*sid = c->sid[0];
2242	rc = 0;
2243out:
2244	read_unlock(&policy_rwlock);
2245	return rc;
2246}
2247
2248/**
2249 * security_fs_use - Determine how to handle labeling for a filesystem.
2250 * @fstype: filesystem type
2251 * @behavior: labeling behavior
2252 * @sid: SID for filesystem (superblock)
2253 */
2254int security_fs_use(
2255	const char *fstype,
2256	unsigned int *behavior,
2257	u32 *sid)
2258{
2259	int rc = 0;
2260	struct ocontext *c;
2261
2262	read_lock(&policy_rwlock);
2263
2264	c = policydb.ocontexts[OCON_FSUSE];
2265	while (c) {
2266		if (strcmp(fstype, c->u.name) == 0)
2267			break;
2268		c = c->next;
2269	}
2270
2271	if (c) {
2272		*behavior = c->v.behavior;
2273		if (!c->sid[0]) {
2274			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2275						   &c->sid[0]);
2276			if (rc)
2277				goto out;
2278		}
2279		*sid = c->sid[0];
2280	} else {
2281		rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2282		if (rc) {
2283			*behavior = SECURITY_FS_USE_NONE;
2284			rc = 0;
2285		} else {
2286			*behavior = SECURITY_FS_USE_GENFS;
2287		}
2288	}
2289
2290out:
2291	read_unlock(&policy_rwlock);
2292	return rc;
2293}
2294
2295int security_get_bools(int *len, char ***names, int **values)
2296{
2297	int i, rc;
2298
2299	read_lock(&policy_rwlock);
2300	*names = NULL;
2301	*values = NULL;
2302
2303	rc = 0;
2304	*len = policydb.p_bools.nprim;
2305	if (!*len)
2306		goto out;
2307
2308	rc = -ENOMEM;
2309	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2310	if (!*names)
2311		goto err;
2312
2313	rc = -ENOMEM;
2314	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2315	if (!*values)
2316		goto err;
2317
2318	for (i = 0; i < *len; i++) {
2319		size_t name_len;
2320
2321		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2322		name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2323
2324		rc = -ENOMEM;
2325		(*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2326		if (!(*names)[i])
2327			goto err;
2328
2329		strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2330		(*names)[i][name_len - 1] = 0;
2331	}
2332	rc = 0;
2333out:
2334	read_unlock(&policy_rwlock);
2335	return rc;
2336err:
2337	if (*names) {
2338		for (i = 0; i < *len; i++)
2339			kfree((*names)[i]);
2340	}
2341	kfree(*values);
2342	goto out;
2343}
2344
2345
2346int security_set_bools(int len, int *values)
2347{
2348	int i, rc;
2349	int lenp, seqno = 0;
2350	struct cond_node *cur;
2351
2352	write_lock_irq(&policy_rwlock);
2353
2354	rc = -EFAULT;
2355	lenp = policydb.p_bools.nprim;
2356	if (len != lenp)
2357		goto out;
2358
2359	for (i = 0; i < len; i++) {
2360		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2361			audit_log(current->audit_context, GFP_ATOMIC,
2362				AUDIT_MAC_CONFIG_CHANGE,
2363				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2364				policydb.p_bool_val_to_name[i],
2365				!!values[i],
2366				policydb.bool_val_to_struct[i]->state,
2367				audit_get_loginuid(current),
2368				audit_get_sessionid(current));
2369		}
2370		if (values[i])
2371			policydb.bool_val_to_struct[i]->state = 1;
2372		else
2373			policydb.bool_val_to_struct[i]->state = 0;
2374	}
2375
2376	for (cur = policydb.cond_list; cur; cur = cur->next) {
2377		rc = evaluate_cond_node(&policydb, cur);
2378		if (rc)
2379			goto out;
2380	}
2381
2382	seqno = ++latest_granting;
2383	rc = 0;
2384out:
2385	write_unlock_irq(&policy_rwlock);
2386	if (!rc) {
2387		avc_ss_reset(seqno);
2388		selnl_notify_policyload(seqno);
2389		selinux_status_update_policyload(seqno);
2390		selinux_xfrm_notify_policyload();
2391	}
2392	return rc;
2393}
2394
2395int security_get_bool_value(int bool)
2396{
2397	int rc;
2398	int len;
2399
2400	read_lock(&policy_rwlock);
2401
2402	rc = -EFAULT;
2403	len = policydb.p_bools.nprim;
2404	if (bool >= len)
2405		goto out;
2406
2407	rc = policydb.bool_val_to_struct[bool]->state;
2408out:
2409	read_unlock(&policy_rwlock);
2410	return rc;
2411}
2412
2413static int security_preserve_bools(struct policydb *p)
2414{
2415	int rc, nbools = 0, *bvalues = NULL, i;
2416	char **bnames = NULL;
2417	struct cond_bool_datum *booldatum;
2418	struct cond_node *cur;
2419
2420	rc = security_get_bools(&nbools, &bnames, &bvalues);
2421	if (rc)
2422		goto out;
2423	for (i = 0; i < nbools; i++) {
2424		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2425		if (booldatum)
2426			booldatum->state = bvalues[i];
2427	}
2428	for (cur = p->cond_list; cur; cur = cur->next) {
2429		rc = evaluate_cond_node(p, cur);
2430		if (rc)
2431			goto out;
2432	}
2433
2434out:
2435	if (bnames) {
2436		for (i = 0; i < nbools; i++)
2437			kfree(bnames[i]);
2438	}
2439	kfree(bnames);
2440	kfree(bvalues);
2441	return rc;
2442}
2443
2444/*
2445 * security_sid_mls_copy() - computes a new sid based on the given
2446 * sid and the mls portion of mls_sid.
2447 */
2448int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2449{
2450	struct context *context1;
2451	struct context *context2;
2452	struct context newcon;
2453	char *s;
2454	u32 len;
2455	int rc;
2456
2457	rc = 0;
2458	if (!ss_initialized || !policydb.mls_enabled) {
2459		*new_sid = sid;
2460		goto out;
2461	}
2462
2463	context_init(&newcon);
2464
2465	read_lock(&policy_rwlock);
2466
2467	rc = -EINVAL;
2468	context1 = sidtab_search(&sidtab, sid);
2469	if (!context1) {
2470		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2471			__func__, sid);
2472		goto out_unlock;
2473	}
2474
2475	rc = -EINVAL;
2476	context2 = sidtab_search(&sidtab, mls_sid);
2477	if (!context2) {
2478		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2479			__func__, mls_sid);
2480		goto out_unlock;
2481	}
2482
2483	newcon.user = context1->user;
2484	newcon.role = context1->role;
2485	newcon.type = context1->type;
2486	rc = mls_context_cpy(&newcon, context2);
2487	if (rc)
2488		goto out_unlock;
2489
2490	/* Check the validity of the new context. */
2491	if (!policydb_context_isvalid(&policydb, &newcon)) {
2492		rc = convert_context_handle_invalid_context(&newcon);
2493		if (rc) {
2494			if (!context_struct_to_string(&newcon, &s, &len)) {
2495				audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2496					  "security_sid_mls_copy: invalid context %s", s);
2497				kfree(s);
2498			}
2499			goto out_unlock;
2500		}
2501	}
2502
2503	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2504out_unlock:
2505	read_unlock(&policy_rwlock);
2506	context_destroy(&newcon);
2507out:
2508	return rc;
2509}
2510
2511/**
2512 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2513 * @nlbl_sid: NetLabel SID
2514 * @nlbl_type: NetLabel labeling protocol type
2515 * @xfrm_sid: XFRM SID
2516 *
2517 * Description:
2518 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2519 * resolved into a single SID it is returned via @peer_sid and the function
2520 * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2521 * returns a negative value.  A table summarizing the behavior is below:
2522 *
2523 *                                 | function return |      @sid
2524 *   ------------------------------+-----------------+-----------------
2525 *   no peer labels                |        0        |    SECSID_NULL
2526 *   single peer label             |        0        |    <peer_label>
2527 *   multiple, consistent labels   |        0        |    <peer_label>
2528 *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2529 *
2530 */
2531int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2532				 u32 xfrm_sid,
2533				 u32 *peer_sid)
2534{
2535	int rc;
2536	struct context *nlbl_ctx;
2537	struct context *xfrm_ctx;
2538
2539	*peer_sid = SECSID_NULL;
2540
2541	/* handle the common (which also happens to be the set of easy) cases
2542	 * right away, these two if statements catch everything involving a
2543	 * single or absent peer SID/label */
2544	if (xfrm_sid == SECSID_NULL) {
2545		*peer_sid = nlbl_sid;
2546		return 0;
2547	}
2548	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2549	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2550	 * is present */
2551	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2552		*peer_sid = xfrm_sid;
2553		return 0;
2554	}
2555
2556	/* we don't need to check ss_initialized here since the only way both
2557	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2558	 * security server was initialized and ss_initialized was true */
2559	if (!policydb.mls_enabled)
2560		return 0;
2561
2562	read_lock(&policy_rwlock);
2563
2564	rc = -EINVAL;
2565	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2566	if (!nlbl_ctx) {
2567		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2568		       __func__, nlbl_sid);
2569		goto out;
2570	}
2571	rc = -EINVAL;
2572	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2573	if (!xfrm_ctx) {
2574		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2575		       __func__, xfrm_sid);
2576		goto out;
2577	}
2578	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2579	if (rc)
2580		goto out;
2581
2582	/* at present NetLabel SIDs/labels really only carry MLS
2583	 * information so if the MLS portion of the NetLabel SID
2584	 * matches the MLS portion of the labeled XFRM SID/label
2585	 * then pass along the XFRM SID as it is the most
2586	 * expressive */
2587	*peer_sid = xfrm_sid;
2588out:
2589	read_unlock(&policy_rwlock);
2590	return rc;
2591}
2592
2593static int get_classes_callback(void *k, void *d, void *args)
2594{
2595	struct class_datum *datum = d;
2596	char *name = k, **classes = args;
2597	int value = datum->value - 1;
2598
2599	classes[value] = kstrdup(name, GFP_ATOMIC);
2600	if (!classes[value])
2601		return -ENOMEM;
2602
2603	return 0;
2604}
2605
2606int security_get_classes(char ***classes, int *nclasses)
2607{
2608	int rc;
2609
2610	read_lock(&policy_rwlock);
2611
2612	rc = -ENOMEM;
2613	*nclasses = policydb.p_classes.nprim;
2614	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2615	if (!*classes)
2616		goto out;
2617
2618	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2619			*classes);
2620	if (rc) {
2621		int i;
2622		for (i = 0; i < *nclasses; i++)
2623			kfree((*classes)[i]);
2624		kfree(*classes);
2625	}
2626
2627out:
2628	read_unlock(&policy_rwlock);
2629	return rc;
2630}
2631
2632static int get_permissions_callback(void *k, void *d, void *args)
2633{
2634	struct perm_datum *datum = d;
2635	char *name = k, **perms = args;
2636	int value = datum->value - 1;
2637
2638	perms[value] = kstrdup(name, GFP_ATOMIC);
2639	if (!perms[value])
2640		return -ENOMEM;
2641
2642	return 0;
2643}
2644
2645int security_get_permissions(char *class, char ***perms, int *nperms)
2646{
2647	int rc, i;
2648	struct class_datum *match;
2649
2650	read_lock(&policy_rwlock);
2651
2652	rc = -EINVAL;
2653	match = hashtab_search(policydb.p_classes.table, class);
2654	if (!match) {
2655		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2656			__func__, class);
2657		goto out;
2658	}
2659
2660	rc = -ENOMEM;
2661	*nperms = match->permissions.nprim;
2662	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2663	if (!*perms)
2664		goto out;
2665
2666	if (match->comdatum) {
2667		rc = hashtab_map(match->comdatum->permissions.table,
2668				get_permissions_callback, *perms);
2669		if (rc)
2670			goto err;
2671	}
2672
2673	rc = hashtab_map(match->permissions.table, get_permissions_callback,
2674			*perms);
2675	if (rc)
2676		goto err;
2677
2678out:
2679	read_unlock(&policy_rwlock);
2680	return rc;
2681
2682err:
2683	read_unlock(&policy_rwlock);
2684	for (i = 0; i < *nperms; i++)
2685		kfree((*perms)[i]);
2686	kfree(*perms);
2687	return rc;
2688}
2689
2690int security_get_reject_unknown(void)
2691{
2692	return policydb.reject_unknown;
2693}
2694
2695int security_get_allow_unknown(void)
2696{
2697	return policydb.allow_unknown;
2698}
2699
2700/**
2701 * security_policycap_supported - Check for a specific policy capability
2702 * @req_cap: capability
2703 *
2704 * Description:
2705 * This function queries the currently loaded policy to see if it supports the
2706 * capability specified by @req_cap.  Returns true (1) if the capability is
2707 * supported, false (0) if it isn't supported.
2708 *
2709 */
2710int security_policycap_supported(unsigned int req_cap)
2711{
2712	int rc;
2713
2714	read_lock(&policy_rwlock);
2715	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2716	read_unlock(&policy_rwlock);
2717
2718	return rc;
2719}
2720
2721struct selinux_audit_rule {
2722	u32 au_seqno;
2723	struct context au_ctxt;
2724};
2725
2726void selinux_audit_rule_free(void *vrule)
2727{
2728	struct selinux_audit_rule *rule = vrule;
2729
2730	if (rule) {
2731		context_destroy(&rule->au_ctxt);
2732		kfree(rule);
2733	}
2734}
2735
2736int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2737{
2738	struct selinux_audit_rule *tmprule;
2739	struct role_datum *roledatum;
2740	struct type_datum *typedatum;
2741	struct user_datum *userdatum;
2742	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2743	int rc = 0;
2744
2745	*rule = NULL;
2746
2747	if (!ss_initialized)
2748		return -EOPNOTSUPP;
2749
2750	switch (field) {
2751	case AUDIT_SUBJ_USER:
2752	case AUDIT_SUBJ_ROLE:
2753	case AUDIT_SUBJ_TYPE:
2754	case AUDIT_OBJ_USER:
2755	case AUDIT_OBJ_ROLE:
2756	case AUDIT_OBJ_TYPE:
2757		/* only 'equals' and 'not equals' fit user, role, and type */
2758		if (op != Audit_equal && op != Audit_not_equal)
2759			return -EINVAL;
2760		break;
2761	case AUDIT_SUBJ_SEN:
2762	case AUDIT_SUBJ_CLR:
2763	case AUDIT_OBJ_LEV_LOW:
2764	case AUDIT_OBJ_LEV_HIGH:
2765		/* we do not allow a range, indicated by the presense of '-' */
2766		if (strchr(rulestr, '-'))
2767			return -EINVAL;
2768		break;
2769	default:
2770		/* only the above fields are valid */
2771		return -EINVAL;
2772	}
2773
2774	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2775	if (!tmprule)
2776		return -ENOMEM;
2777
2778	context_init(&tmprule->au_ctxt);
2779
2780	read_lock(&policy_rwlock);
2781
2782	tmprule->au_seqno = latest_granting;
2783
2784	switch (field) {
2785	case AUDIT_SUBJ_USER:
2786	case AUDIT_OBJ_USER:
2787		rc = -EINVAL;
2788		userdatum = hashtab_search(policydb.p_users.table, rulestr);
2789		if (!userdatum)
2790			goto out;
2791		tmprule->au_ctxt.user = userdatum->value;
2792		break;
2793	case AUDIT_SUBJ_ROLE:
2794	case AUDIT_OBJ_ROLE:
2795		rc = -EINVAL;
2796		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2797		if (!roledatum)
2798			goto out;
2799		tmprule->au_ctxt.role = roledatum->value;
2800		break;
2801	case AUDIT_SUBJ_TYPE:
2802	case AUDIT_OBJ_TYPE:
2803		rc = -EINVAL;
2804		typedatum = hashtab_search(policydb.p_types.table, rulestr);
2805		if (!typedatum)
2806			goto out;
2807		tmprule->au_ctxt.type = typedatum->value;
2808		break;
2809	case AUDIT_SUBJ_SEN:
2810	case AUDIT_SUBJ_CLR:
2811	case AUDIT_OBJ_LEV_LOW:
2812	case AUDIT_OBJ_LEV_HIGH:
2813		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2814		if (rc)
2815			goto out;
2816		break;
2817	}
2818	rc = 0;
2819out:
2820	read_unlock(&policy_rwlock);
2821
2822	if (rc) {
2823		selinux_audit_rule_free(tmprule);
2824		tmprule = NULL;
2825	}
2826
2827	*rule = tmprule;
2828
2829	return rc;
2830}
2831
2832/* Check to see if the rule contains any selinux fields */
2833int selinux_audit_rule_known(struct audit_krule *rule)
2834{
2835	int i;
2836
2837	for (i = 0; i < rule->field_count; i++) {
2838		struct audit_field *f = &rule->fields[i];
2839		switch (f->type) {
2840		case AUDIT_SUBJ_USER:
2841		case AUDIT_SUBJ_ROLE:
2842		case AUDIT_SUBJ_TYPE:
2843		case AUDIT_SUBJ_SEN:
2844		case AUDIT_SUBJ_CLR:
2845		case AUDIT_OBJ_USER:
2846		case AUDIT_OBJ_ROLE:
2847		case AUDIT_OBJ_TYPE:
2848		case AUDIT_OBJ_LEV_LOW:
2849		case AUDIT_OBJ_LEV_HIGH:
2850			return 1;
2851		}
2852	}
2853
2854	return 0;
2855}
2856
2857int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2858			     struct audit_context *actx)
2859{
2860	struct context *ctxt;
2861	struct mls_level *level;
2862	struct selinux_audit_rule *rule = vrule;
2863	int match = 0;
2864
2865	if (!rule) {
2866		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2867			  "selinux_audit_rule_match: missing rule\n");
2868		return -ENOENT;
2869	}
2870
2871	read_lock(&policy_rwlock);
2872
2873	if (rule->au_seqno < latest_granting) {
2874		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2875			  "selinux_audit_rule_match: stale rule\n");
2876		match = -ESTALE;
2877		goto out;
2878	}
2879
2880	ctxt = sidtab_search(&sidtab, sid);
2881	if (!ctxt) {
2882		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2883			  "selinux_audit_rule_match: unrecognized SID %d\n",
2884			  sid);
2885		match = -ENOENT;
2886		goto out;
2887	}
2888
2889	/* a field/op pair that is not caught here will simply fall through
2890	   without a match */
2891	switch (field) {
2892	case AUDIT_SUBJ_USER:
2893	case AUDIT_OBJ_USER:
2894		switch (op) {
2895		case Audit_equal:
2896			match = (ctxt->user == rule->au_ctxt.user);
2897			break;
2898		case Audit_not_equal:
2899			match = (ctxt->user != rule->au_ctxt.user);
2900			break;
2901		}
2902		break;
2903	case AUDIT_SUBJ_ROLE:
2904	case AUDIT_OBJ_ROLE:
2905		switch (op) {
2906		case Audit_equal:
2907			match = (ctxt->role == rule->au_ctxt.role);
2908			break;
2909		case Audit_not_equal:
2910			match = (ctxt->role != rule->au_ctxt.role);
2911			break;
2912		}
2913		break;
2914	case AUDIT_SUBJ_TYPE:
2915	case AUDIT_OBJ_TYPE:
2916		switch (op) {
2917		case Audit_equal:
2918			match = (ctxt->type == rule->au_ctxt.type);
2919			break;
2920		case Audit_not_equal:
2921			match = (ctxt->type != rule->au_ctxt.type);
2922			break;
2923		}
2924		break;
2925	case AUDIT_SUBJ_SEN:
2926	case AUDIT_SUBJ_CLR:
2927	case AUDIT_OBJ_LEV_LOW:
2928	case AUDIT_OBJ_LEV_HIGH:
2929		level = ((field == AUDIT_SUBJ_SEN ||
2930			  field == AUDIT_OBJ_LEV_LOW) ?
2931			 &ctxt->range.level[0] : &ctxt->range.level[1]);
2932		switch (op) {
2933		case Audit_equal:
2934			match = mls_level_eq(&rule->au_ctxt.range.level[0],
2935					     level);
2936			break;
2937		case Audit_not_equal:
2938			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2939					      level);
2940			break;
2941		case Audit_lt:
2942			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2943					       level) &&
2944				 !mls_level_eq(&rule->au_ctxt.range.level[0],
2945					       level));
2946			break;
2947		case Audit_le:
2948			match = mls_level_dom(&rule->au_ctxt.range.level[0],
2949					      level);
2950			break;
2951		case Audit_gt:
2952			match = (mls_level_dom(level,
2953					      &rule->au_ctxt.range.level[0]) &&
2954				 !mls_level_eq(level,
2955					       &rule->au_ctxt.range.level[0]));
2956			break;
2957		case Audit_ge:
2958			match = mls_level_dom(level,
2959					      &rule->au_ctxt.range.level[0]);
2960			break;
2961		}
2962	}
2963
2964out:
2965	read_unlock(&policy_rwlock);
2966	return match;
2967}
2968
2969static int (*aurule_callback)(void) = audit_update_lsm_rules;
2970
2971static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2972			       u16 class, u32 perms, u32 *retained)
2973{
2974	int err = 0;
2975
2976	if (event == AVC_CALLBACK_RESET && aurule_callback)
2977		err = aurule_callback();
2978	return err;
2979}
2980
2981static int __init aurule_init(void)
2982{
2983	int err;
2984
2985	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2986			       SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2987	if (err)
2988		panic("avc_add_callback() failed, error %d\n", err);
2989
2990	return err;
2991}
2992__initcall(aurule_init);
2993
2994#ifdef CONFIG_NETLABEL
2995/**
2996 * security_netlbl_cache_add - Add an entry to the NetLabel cache
2997 * @secattr: the NetLabel packet security attributes
2998 * @sid: the SELinux SID
2999 *
3000 * Description:
3001 * Attempt to cache the context in @ctx, which was derived from the packet in
3002 * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3003 * already been initialized.
3004 *
3005 */
3006static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3007				      u32 sid)
3008{
3009	u32 *sid_cache;
3010
3011	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3012	if (sid_cache == NULL)
3013		return;
3014	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3015	if (secattr->cache == NULL) {
3016		kfree(sid_cache);
3017		return;
3018	}
3019
3020	*sid_cache = sid;
3021	secattr->cache->free = kfree;
3022	secattr->cache->data = sid_cache;
3023	secattr->flags |= NETLBL_SECATTR_CACHE;
3024}
3025
3026/**
3027 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3028 * @secattr: the NetLabel packet security attributes
3029 * @sid: the SELinux SID
3030 *
3031 * Description:
3032 * Convert the given NetLabel security attributes in @secattr into a
3033 * SELinux SID.  If the @secattr field does not contain a full SELinux
3034 * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
3035 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3036 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3037 * conversion for future lookups.  Returns zero on success, negative values on
3038 * failure.
3039 *
3040 */
3041int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3042				   u32 *sid)
3043{
3044	int rc;
3045	struct context *ctx;
3046	struct context ctx_new;
3047
3048	if (!ss_initialized) {
3049		*sid = SECSID_NULL;
3050		return 0;
3051	}
3052
3053	read_lock(&policy_rwlock);
3054
3055	if (secattr->flags & NETLBL_SECATTR_CACHE)
3056		*sid = *(u32 *)secattr->cache->data;
3057	else if (secattr->flags & NETLBL_SECATTR_SECID)
3058		*sid = secattr->attr.secid;
3059	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3060		rc = -EIDRM;
3061		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3062		if (ctx == NULL)
3063			goto out;
3064
3065		context_init(&ctx_new);
3066		ctx_new.user = ctx->user;
3067		ctx_new.role = ctx->role;
3068		ctx_new.type = ctx->type;
3069		mls_import_netlbl_lvl(&ctx_new, secattr);
3070		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3071			rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3072						   secattr->attr.mls.cat);
3073			if (rc)
3074				goto out;
3075			memcpy(&ctx_new.range.level[1].cat,
3076			       &ctx_new.range.level[0].cat,
3077			       sizeof(ctx_new.range.level[0].cat));
3078		}
3079		rc = -EIDRM;
3080		if (!mls_context_isvalid(&policydb, &ctx_new))
3081			goto out_free;
3082
3083		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3084		if (rc)
3085			goto out_free;
3086
3087		security_netlbl_cache_add(secattr, *sid);
3088
3089		ebitmap_destroy(&ctx_new.range.level[0].cat);
3090	} else
3091		*sid = SECSID_NULL;
3092
3093	read_unlock(&policy_rwlock);
3094	return 0;
3095out_free:
3096	ebitmap_destroy(&ctx_new.range.level[0].cat);
3097out:
3098	read_unlock(&policy_rwlock);
3099	return rc;
3100}
3101
3102/**
3103 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3104 * @sid: the SELinux SID
3105 * @secattr: the NetLabel packet security attributes
3106 *
3107 * Description:
3108 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3109 * Returns zero on success, negative values on failure.
3110 *
3111 */
3112int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3113{
3114	int rc;
3115	struct context *ctx;
3116
3117	if (!ss_initialized)
3118		return 0;
3119
3120	read_lock(&policy_rwlock);
3121
3122	rc = -ENOENT;
3123	ctx = sidtab_search(&sidtab, sid);
3124	if (ctx == NULL)
3125		goto out;
3126
3127	rc = -ENOMEM;
3128	secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
3129				  GFP_ATOMIC);
3130	if (secattr->domain == NULL)
3131		goto out;
3132
3133	secattr->attr.secid = sid;
3134	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3135	mls_export_netlbl_lvl(ctx, secattr);
3136	rc = mls_export_netlbl_cat(ctx, secattr);
3137out:
3138	read_unlock(&policy_rwlock);
3139	return rc;
3140}
3141#endif /* CONFIG_NETLABEL */
3142
3143/**
3144 * security_read_policy - read the policy.
3145 * @data: binary policy data
3146 * @len: length of data in bytes
3147 *
3148 */
3149int security_read_policy(void **data, ssize_t *len)
3150{
3151	int rc;
3152	struct policy_file fp;
3153
3154	if (!ss_initialized)
3155		return -EINVAL;
3156
3157	*len = security_policydb_len();
3158
3159	*data = vmalloc_user(*len);
3160	if (!*data)
3161		return -ENOMEM;
3162
3163	fp.data = *data;
3164	fp.len = *len;
3165
3166	read_lock(&policy_rwlock);
3167	rc = policydb_write(&policydb, &fp);
3168	read_unlock(&policy_rwlock);
3169
3170	if (rc)
3171		return rc;
3172
3173	*len = (unsigned long)fp.data - (unsigned long)*data;
3174	return 0;
3175
3176}
3177