text: /*
   * Implementation of the security services.
   *
   * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   *	     James Morris <jmorris@redhat.com>
   *
   * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   *
   *	Support for enhanced MLS infrastructure.
   *	Support for context based audit filters.
   *
   * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
   *
   *	Added conditional policy language extensions
   *
   * Updated: Hewlett-Packard <paul@paul-moore.com>
   *
   *      Added support for NetLabel
   *      Added support for the policy capability bitmap
   *
   * Updated: Chad Sellers <csellers@tresys.com>
   *
   *  Added validation of kernel classes and permissions
   *
   * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
   *
   *  Added support for bounds domain and audit messaged on masked permissions
   *
   * Updated: Guido Trentalancia <guido@trentalancia.com>
   *
   *  Added support for runtime switching of the policy type
   *
   * Copyright (C) 2008, 2009 NEC Corporation
   * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
   * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
   * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
   * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
   *	This program is free software; you can redistribute it and/or modify
   *	it under the terms of the GNU General Public License as published by
   *	the Free Software Foundation, version 2.
   */
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/spinlock.h>
  #include <linux/rcupdate.h>
  #include <linux/errno.h>
  #include <linux/in.h>
  #include <linux/sched.h>
  #include <linux/audit.h>
  #include <linux/mutex.h>
  #include <linux/selinux.h>
  #include <linux/flex_array.h>
  #include <linux/vmalloc.h>
  #include <net/netlabel.h>
  
  #include "flask.h"
  #include "avc.h"
  #include "avc_ss.h"
  #include "security.h"
  #include "context.h"
  #include "policydb.h"
  #include "sidtab.h"
  #include "services.h"
  #include "conditional.h"
  #include "mls.h"
  #include "objsec.h"
  #include "netlabel.h"
  #include "xfrm.h"
  #include "ebitmap.h"
  #include "audit.h"
  
  int selinux_policycap_netpeer;
  int selinux_policycap_openperm;
  int selinux_policycap_alwaysnetwork;
  
  static DEFINE_RWLOCK(policy_rwlock);
  
  static struct sidtab sidtab;
  struct policydb policydb;
  int ss_initialized;
  
  /*
   * The largest sequence number that has been used when
   * providing an access decision to the access vector cache.
   * The sequence number only changes when a policy change
   * occurs.
   */
  static u32 latest_granting;
  
  /* Forward declaration. */
  static int context_struct_to_string(struct context *context, char **scontext,
  				    u32 *scontext_len);
  
  static void context_struct_compute_av(struct context *scontext,
  					struct context *tcontext,
  					u16 tclass,
  					struct av_decision *avd,
  					struct extended_perms *xperms);
  
  struct selinux_mapping {
  	u16 value; /* policy value */
  	unsigned num_perms;
  	u32 perms[sizeof(u32) * 8];
  };
  
  static struct selinux_mapping *current_mapping;
  static u16 current_mapping_size;
  
  static int selinux_set_mapping(struct policydb *pol,
  			       struct security_class_mapping *map,
  			       struct selinux_mapping **out_map_p,
  			       u16 *out_map_size)
  {
  	struct selinux_mapping *out_map = NULL;
  	size_t size = sizeof(struct selinux_mapping);
  	u16 i, j;
  	unsigned k;
  	bool print_unknown_handle = false;
  
  	/* Find number of classes in the input mapping */
  	if (!map)
  		return -EINVAL;
  	i = 0;
  	while (map[i].name)
  		i++;
  
  	/* Allocate space for the class records, plus one for class zero */
  	out_map = kcalloc(++i, size, GFP_ATOMIC);
  	if (!out_map)
  		return -ENOMEM;
  
  	/* Store the raw class and permission values */
  	j = 0;
  	while (map[j].name) {
  		struct security_class_mapping *p_in = map + (j++);
  		struct selinux_mapping *p_out = out_map + j;
  
  		/* An empty class string skips ahead */
  		if (!strcmp(p_in->name, "")) {
  			p_out->num_perms = 0;
  			continue;
  		}
  
  		p_out->value = string_to_security_class(pol, p_in->name);
  		if (!p_out->value) {
  			printk(KERN_INFO
  			       "SELinux:  Class %s not defined in policy.\n",
  			       p_in->name);
  			if (pol->reject_unknown)
  				goto err;
  			p_out->num_perms = 0;
  			print_unknown_handle = true;
  			continue;
  		}
  
  		k = 0;
  		while (p_in->perms && p_in->perms[k]) {
  			/* An empty permission string skips ahead */
  			if (!*p_in->perms[k]) {
  				k++;
  				continue;
  			}
  			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
  							    p_in->perms[k]);
  			if (!p_out->perms[k]) {
  				printk(KERN_INFO
  				       "SELinux:  Permission %s in class %s not defined in policy.\n",
  				       p_in->perms[k], p_in->name);
  				if (pol->reject_unknown)
  					goto err;
  				print_unknown_handle = true;
  			}
  
  			k++;
  		}
  		p_out->num_perms = k;
  	}
  
  	if (print_unknown_handle)
  		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
  		       pol->allow_unknown ? "allowed" : "denied");
  
  	*out_map_p = out_map;
  	*out_map_size = i;
  	return 0;
  err:
  	kfree(out_map);
  	return -EINVAL;
  }
  
  /*
   * Get real, policy values from mapped values
   */
  
  static u16 unmap_class(u16 tclass)
  {
  	if (tclass < current_mapping_size)
  		return current_mapping[tclass].value;
  
  	return tclass;
  }
  
  /*
   * Get kernel value for class from its policy value
   */
  static u16 map_class(u16 pol_value)
  {
  	u16 i;
  
  	for (i = 1; i < current_mapping_size; i++) {
  		if (current_mapping[i].value == pol_value)
  			return i;
  	}
  
  	return SECCLASS_NULL;
  }
  
  static void map_decision(u16 tclass, struct av_decision *avd,
  			 int allow_unknown)
  {
  	if (tclass < current_mapping_size) {
  		unsigned i, n = current_mapping[tclass].num_perms;
  		u32 result;
  
  		for (i = 0, result = 0; i < n; i++) {
  			if (avd->allowed & current_mapping[tclass].perms[i])
  				result |= 1<<i;
  			if (allow_unknown && !current_mapping[tclass].perms[i])
  				result |= 1<<i;
  		}
  		avd->allowed = result;
  
  		for (i = 0, result = 0; i < n; i++)
  			if (avd->auditallow & current_mapping[tclass].perms[i])
  				result |= 1<<i;
  		avd->auditallow = result;
  
  		for (i = 0, result = 0; i < n; i++) {
  			if (avd->auditdeny & current_mapping[tclass].perms[i])
  				result |= 1<<i;
  			if (!allow_unknown && !current_mapping[tclass].perms[i])
  				result |= 1<<i;
  		}
  		/*
  		 * In case the kernel has a bug and requests a permission
  		 * between num_perms and the maximum permission number, we
  		 * should audit that denial
  		 */
  		for (; i < (sizeof(u32)*8); i++)
  			result |= 1<<i;
  		avd->auditdeny = result;
  	}
  }
  
  int security_mls_enabled(void)
  {
  	return policydb.mls_enabled;
  }
  
  /*
   * Return the boolean value of a constraint expression
   * when it is applied to the specified source and target
   * security contexts.
   *
   * xcontext is a special beast...  It is used by the validatetrans rules
   * only.  For these rules, scontext is the context before the transition,
   * tcontext is the context after the transition, and xcontext is the context
   * of the process performing the transition.  All other callers of
   * constraint_expr_eval should pass in NULL for xcontext.
   */
  static int constraint_expr_eval(struct context *scontext,
  				struct context *tcontext,
  				struct context *xcontext,
  				struct constraint_expr *cexpr)
  {
  	u32 val1, val2;
  	struct context *c;
  	struct role_datum *r1, *r2;
  	struct mls_level *l1, *l2;
  	struct constraint_expr *e;
  	int s[CEXPR_MAXDEPTH];
  	int sp = -1;
  
  	for (e = cexpr; e; e = e->next) {
  		switch (e->expr_type) {
  		case CEXPR_NOT:
  			BUG_ON(sp < 0);
  			s[sp] = !s[sp];
  			break;
  		case CEXPR_AND:
  			BUG_ON(sp < 1);
  			sp--;
  			s[sp] &= s[sp + 1];
  			break;
  		case CEXPR_OR:
  			BUG_ON(sp < 1);
  			sp--;
  			s[sp] |= s[sp + 1];
  			break;
  		case CEXPR_ATTR:
  			if (sp == (CEXPR_MAXDEPTH - 1))
  				return 0;
  			switch (e->attr) {
  			case CEXPR_USER:
  				val1 = scontext->user;
  				val2 = tcontext->user;
  				break;
  			case CEXPR_TYPE:
  				val1 = scontext->type;
  				val2 = tcontext->type;
  				break;
  			case CEXPR_ROLE:
  				val1 = scontext->role;
  				val2 = tcontext->role;
  				r1 = policydb.role_val_to_struct[val1 - 1];
  				r2 = policydb.role_val_to_struct[val2 - 1];
  				switch (e->op) {
  				case CEXPR_DOM:
  					s[++sp] = ebitmap_get_bit(&r1->dominates,
  								  val2 - 1);
  					continue;
  				case CEXPR_DOMBY:
  					s[++sp] = ebitmap_get_bit(&r2->dominates,
  								  val1 - 1);
  					continue;
  				case CEXPR_INCOMP:
  					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
  								    val2 - 1) &&
  						   !ebitmap_get_bit(&r2->dominates,
  								    val1 - 1));
  					continue;
  				default:
  					break;
  				}
  				break;
  			case CEXPR_L1L2:
  				l1 = &(scontext->range.level[0]);
  				l2 = &(tcontext->range.level[0]);
  				goto mls_ops;
  			case CEXPR_L1H2:
  				l1 = &(scontext->range.level[0]);
  				l2 = &(tcontext->range.level[1]);
  				goto mls_ops;
  			case CEXPR_H1L2:
  				l1 = &(scontext->range.level[1]);
  				l2 = &(tcontext->range.level[0]);
  				goto mls_ops;
  			case CEXPR_H1H2:
  				l1 = &(scontext->range.level[1]);
  				l2 = &(tcontext->range.level[1]);
  				goto mls_ops;
  			case CEXPR_L1H1:
  				l1 = &(scontext->range.level[0]);
  				l2 = &(scontext->range.level[1]);
  				goto mls_ops;
  			case CEXPR_L2H2:
  				l1 = &(tcontext->range.level[0]);
  				l2 = &(tcontext->range.level[1]);
  				goto mls_ops;
  mls_ops:
  			switch (e->op) {
  			case CEXPR_EQ:
  				s[++sp] = mls_level_eq(l1, l2);
  				continue;
  			case CEXPR_NEQ:
  				s[++sp] = !mls_level_eq(l1, l2);
  				continue;
  			case CEXPR_DOM:
  				s[++sp] = mls_level_dom(l1, l2);
  				continue;
  			case CEXPR_DOMBY:
  				s[++sp] = mls_level_dom(l2, l1);
  				continue;
  			case CEXPR_INCOMP:
  				s[++sp] = mls_level_incomp(l2, l1);
  				continue;
  			default:
  				BUG();
  				return 0;
  			}
  			break;
  			default:
  				BUG();
  				return 0;
  			}
  
  			switch (e->op) {
  			case CEXPR_EQ:
  				s[++sp] = (val1 == val2);
  				break;
  			case CEXPR_NEQ:
  				s[++sp] = (val1 != val2);
  				break;
  			default:
  				BUG();
  				return 0;
  			}
  			break;
  		case CEXPR_NAMES:
  			if (sp == (CEXPR_MAXDEPTH-1))
  				return 0;
  			c = scontext;
  			if (e->attr & CEXPR_TARGET)
  				c = tcontext;
  			else if (e->attr & CEXPR_XTARGET) {
  				c = xcontext;
  				if (!c) {
  					BUG();
  					return 0;
  				}
  			}
  			if (e->attr & CEXPR_USER)
  				val1 = c->user;
  			else if (e->attr & CEXPR_ROLE)
  				val1 = c->role;
  			else if (e->attr & CEXPR_TYPE)
  				val1 = c->type;
  			else {
  				BUG();
  				return 0;
  			}
  
  			switch (e->op) {
  			case CEXPR_EQ:
  				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
  				break;
  			case CEXPR_NEQ:
  				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
  				break;
  			default:
  				BUG();
  				return 0;
  			}
  			break;
  		default:
  			BUG();
  			return 0;
  		}
  	}
  
  	BUG_ON(sp != 0);
  	return s[0];
  }
  
  /*
   * security_dump_masked_av - dumps masked permissions during
   * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
   */
  static int dump_masked_av_helper(void *k, void *d, void *args)
  {
  	struct perm_datum *pdatum = d;
  	char **permission_names = args;
  
  	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
  
  	permission_names[pdatum->value - 1] = (char *)k;
  
  	return 0;
  }
  
  static void security_dump_masked_av(struct context *scontext,
  				    struct context *tcontext,
  				    u16 tclass,
  				    u32 permissions,
  				    const char *reason)
  {
  	struct common_datum *common_dat;
  	struct class_datum *tclass_dat;
  	struct audit_buffer *ab;
  	char *tclass_name;
  	char *scontext_name = NULL;
  	char *tcontext_name = NULL;
  	char *permission_names[32];
  	int index;
  	u32 length;
  	bool need_comma = false;
  
  	if (!permissions)
  		return;
  
  	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
  	tclass_dat = policydb.class_val_to_struct[tclass - 1];
  	common_dat = tclass_dat->comdatum;
  
  	/* init permission_names */
  	if (common_dat &&
  	    hashtab_map(common_dat->permissions.table,
  			dump_masked_av_helper, permission_names) < 0)
  		goto out;
  
  	if (hashtab_map(tclass_dat->permissions.table,
  			dump_masked_av_helper, permission_names) < 0)
  		goto out;
  
  	/* get scontext/tcontext in text form */
  	if (context_struct_to_string(scontext,
  				     &scontext_name, &length) < 0)
  		goto out;
  
  	if (context_struct_to_string(tcontext,
  				     &tcontext_name, &length) < 0)
  		goto out;
  
  	/* audit a message */
  	ab = audit_log_start(current->audit_context,
  			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
  	if (!ab)
  		goto out;
  
  	audit_log_format(ab, "op=security_compute_av reason=%s "
  			 "scontext=%s tcontext=%s tclass=%s perms=",
  			 reason, scontext_name, tcontext_name, tclass_name);
  
  	for (index = 0; index < 32; index++) {
  		u32 mask = (1 << index);
  
  		if ((mask & permissions) == 0)
  			continue;
  
  		audit_log_format(ab, "%s%s",
  				 need_comma ? "," : "",
  				 permission_names[index]
  				 ? permission_names[index] : "????");
  		need_comma = true;
  	}
  	audit_log_end(ab);
  out:
  	/* release scontext/tcontext */
  	kfree(tcontext_name);
  	kfree(scontext_name);
  
  	return;
  }
  
  /*
   * security_boundary_permission - drops violated permissions
   * on boundary constraint.
   */
  static void type_attribute_bounds_av(struct context *scontext,
  				     struct context *tcontext,
  				     u16 tclass,
  				     struct av_decision *avd)
  {
  	struct context lo_scontext;
  	struct context lo_tcontext;
  	struct av_decision lo_avd;
  	struct type_datum *source;
  	struct type_datum *target;
  	u32 masked = 0;
  
  	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
  				    scontext->type - 1);
  	BUG_ON(!source);
  
  	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
  				    tcontext->type - 1);
  	BUG_ON(!target);
  
  	if (source->bounds) {
  		memset(&lo_avd, 0, sizeof(lo_avd));
  
  		memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
  		lo_scontext.type = source->bounds;
  
  		context_struct_compute_av(&lo_scontext,
  					  tcontext,
  					  tclass,
  					  &lo_avd,
  					  NULL);
  		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
  			return;		/* no masked permission */
  		masked = ~lo_avd.allowed & avd->allowed;
  	}
  
  	if (target->bounds) {
  		memset(&lo_avd, 0, sizeof(lo_avd));
  
  		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
  		lo_tcontext.type = target->bounds;
  
  		context_struct_compute_av(scontext,
  					  &lo_tcontext,
  					  tclass,
  					  &lo_avd,
  					  NULL);
  		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
  			return;		/* no masked permission */
  		masked = ~lo_avd.allowed & avd->allowed;
  	}
  
  	if (source->bounds && target->bounds) {
  		memset(&lo_avd, 0, sizeof(lo_avd));
  		/*
  		 * lo_scontext and lo_tcontext are already
  		 * set up.
  		 */
  
  		context_struct_compute_av(&lo_scontext,
  					  &lo_tcontext,
  					  tclass,
  					  &lo_avd,
  					  NULL);
  		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
  			return;		/* no masked permission */
  		masked = ~lo_avd.allowed & avd->allowed;
  	}
  
  	if (masked) {
  		/* mask violated permissions */
  		avd->allowed &= ~masked;
  
  		/* audit masked permissions */
  		security_dump_masked_av(scontext, tcontext,
  					tclass, masked, "bounds");
  	}
  }
  
  /*
   * flag which drivers have permissions
   * only looking for ioctl based extended permssions
   */
  void services_compute_xperms_drivers(
  		struct extended_perms *xperms,
  		struct avtab_node *node)
  {
  	unsigned int i;
  
  	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
  		/* if one or more driver has all permissions allowed */
  		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
  			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
  	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
  		/* if allowing permissions within a driver */
  		security_xperm_set(xperms->drivers.p,
  					node->datum.u.xperms->driver);
  	}
  
  	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
  	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
  		xperms->len = 1;
  }
  
  /*
   * Compute access vectors and extended permissions based on a context
   * structure pair for the permissions in a particular class.
   */
  static void context_struct_compute_av(struct context *scontext,
  					struct context *tcontext,
  					u16 tclass,
  					struct av_decision *avd,
  					struct extended_perms *xperms)
  {
  	struct constraint_node *constraint;
  	struct role_allow *ra;
  	struct avtab_key avkey;
  	struct avtab_node *node;
  	struct class_datum *tclass_datum;
  	struct ebitmap *sattr, *tattr;
  	struct ebitmap_node *snode, *tnode;
  	unsigned int i, j;
  
  	avd->allowed = 0;
  	avd->auditallow = 0;
  	avd->auditdeny = 0xffffffff;
  	if (xperms) {
  		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
  		xperms->len = 0;
  	}
  
  	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
  		if (printk_ratelimit())
  			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
  		return;
  	}
  
  	tclass_datum = policydb.class_val_to_struct[tclass - 1];
  
  	/*
  	 * If a specific type enforcement rule was defined for
  	 * this permission check, then use it.
  	 */
  	avkey.target_class = tclass;
  	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
  	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
  	BUG_ON(!sattr);
  	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
  	BUG_ON(!tattr);
  	ebitmap_for_each_positive_bit(sattr, snode, i) {
  		ebitmap_for_each_positive_bit(tattr, tnode, j) {
  			avkey.source_type = i + 1;
  			avkey.target_type = j + 1;
  			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
  			     node;
  			     node = avtab_search_node_next(node, avkey.specified)) {
  				if (node->key.specified == AVTAB_ALLOWED)
  					avd->allowed |= node->datum.u.data;
  				else if (node->key.specified == AVTAB_AUDITALLOW)
  					avd->auditallow |= node->datum.u.data;
  				else if (node->key.specified == AVTAB_AUDITDENY)
  					avd->auditdeny &= node->datum.u.data;
  				else if (xperms && (node->key.specified & AVTAB_XPERMS))
  					services_compute_xperms_drivers(xperms, node);
  			}
  
  			/* Check conditional av table for additional permissions */
  			cond_compute_av(&policydb.te_cond_avtab, &avkey,
  					avd, xperms);
  
  		}
  	}
  
  	/*
  	 * Remove any permissions prohibited by a constraint (this includes
  	 * the MLS policy).
  	 */
  	constraint = tclass_datum->constraints;
  	while (constraint) {
  		if ((constraint->permissions & (avd->allowed)) &&
  		    !constraint_expr_eval(scontext, tcontext, NULL,
  					  constraint->expr)) {
  			avd->allowed &= ~(constraint->permissions);
  		}
  		constraint = constraint->next;
  	}
  
  	/*
  	 * If checking process transition permission and the
  	 * role is changing, then check the (current_role, new_role)
  	 * pair.
  	 */
  	if (tclass == policydb.process_class &&
  	    (avd->allowed & policydb.process_trans_perms) &&
  	    scontext->role != tcontext->role) {
  		for (ra = policydb.role_allow; ra; ra = ra->next) {
  			if (scontext->role == ra->role &&
  			    tcontext->role == ra->new_role)
  				break;
  		}
  		if (!ra)
  			avd->allowed &= ~policydb.process_trans_perms;
  	}
  
  	/*
  	 * If the given source and target types have boundary
  	 * constraint, lazy checks have to mask any violated
  	 * permission and notice it to userspace via audit.
  	 */
  	type_attribute_bounds_av(scontext, tcontext,
  				 tclass, avd);
  }
  
  static int security_validtrans_handle_fail(struct context *ocontext,
  					   struct context *ncontext,
  					   struct context *tcontext,
  					   u16 tclass)
  {
  	char *o = NULL, *n = NULL, *t = NULL;
  	u32 olen, nlen, tlen;
  
  	if (context_struct_to_string(ocontext, &o, &olen))
  		goto out;
  	if (context_struct_to_string(ncontext, &n, &nlen))
  		goto out;
  	if (context_struct_to_string(tcontext, &t, &tlen))
  		goto out;
  	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
  		  "op=security_validate_transition seresult=denied"
  		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
  		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
  out:
  	kfree(o);
  	kfree(n);
  	kfree(t);
  
  	if (!selinux_enforcing)
  		return 0;
  	return -EPERM;
  }
  
  int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
  				 u16 orig_tclass)
  {
  	struct context *ocontext;
  	struct context *ncontext;
  	struct context *tcontext;
  	struct class_datum *tclass_datum;
  	struct constraint_node *constraint;
  	u16 tclass;
  	int rc = 0;
  
  	if (!ss_initialized)
  		return 0;
  
  	read_lock(&policy_rwlock);
  
  	tclass = unmap_class(orig_tclass);
  
  	if (!tclass || tclass > policydb.p_classes.nprim) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
  			__func__, tclass);
  		rc = -EINVAL;
  		goto out;
  	}
  	tclass_datum = policydb.class_val_to_struct[tclass - 1];
  
  	ocontext = sidtab_search(&sidtab, oldsid);
  	if (!ocontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, oldsid);
  		rc = -EINVAL;
  		goto out;
  	}
  
  	ncontext = sidtab_search(&sidtab, newsid);
  	if (!ncontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, newsid);
  		rc = -EINVAL;
  		goto out;
  	}
  
  	tcontext = sidtab_search(&sidtab, tasksid);
  	if (!tcontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, tasksid);
  		rc = -EINVAL;
  		goto out;
  	}
  
  	constraint = tclass_datum->validatetrans;
  	while (constraint) {
  		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
  					  constraint->expr)) {
  			rc = security_validtrans_handle_fail(ocontext, ncontext,
  							     tcontext, tclass);
  			goto out;
  		}
  		constraint = constraint->next;
  	}
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  /*
   * security_bounded_transition - check whether the given
   * transition is directed to bounded, or not.
   * It returns 0, if @newsid is bounded by @oldsid.
   * Otherwise, it returns error code.
   *
   * @oldsid : current security identifier
   * @newsid : destinated security identifier
   */
  int security_bounded_transition(u32 old_sid, u32 new_sid)
  {
  	struct context *old_context, *new_context;
  	struct type_datum *type;
  	int index;
  	int rc;
  
  	read_lock(&policy_rwlock);
  
  	rc = -EINVAL;
  	old_context = sidtab_search(&sidtab, old_sid);
  	if (!old_context) {
  		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
  		       __func__, old_sid);
  		goto out;
  	}
  
  	rc = -EINVAL;
  	new_context = sidtab_search(&sidtab, new_sid);
  	if (!new_context) {
  		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
  		       __func__, new_sid);
  		goto out;
  	}
  
  	rc = 0;
  	/* type/domain unchanged */
  	if (old_context->type == new_context->type)
  		goto out;
  
  	index = new_context->type;
  	while (true) {
  		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
  					  index - 1);
  		BUG_ON(!type);
  
  		/* not bounded anymore */
  		rc = -EPERM;
  		if (!type->bounds)
  			break;
  
  		/* @newsid is bounded by @oldsid */
  		rc = 0;
  		if (type->bounds == old_context->type)
  			break;
  
  		index = type->bounds;
  	}
  
  	if (rc) {
  		char *old_name = NULL;
  		char *new_name = NULL;
  		u32 length;
  
  		if (!context_struct_to_string(old_context,
  					      &old_name, &length) &&
  		    !context_struct_to_string(new_context,
  					      &new_name, &length)) {
  			audit_log(current->audit_context,
  				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
  				  "op=security_bounded_transition "
  				  "seresult=denied "
  				  "oldcontext=%s newcontext=%s",
  				  old_name, new_name);
  		}
  		kfree(new_name);
  		kfree(old_name);
  	}
  out:
  	read_unlock(&policy_rwlock);
  
  	return rc;
  }
  
  static void avd_init(struct av_decision *avd)
  {
  	avd->allowed = 0;
  	avd->auditallow = 0;
  	avd->auditdeny = 0xffffffff;
  	avd->seqno = latest_granting;
  	avd->flags = 0;
  }
  
  void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
  					struct avtab_node *node)
  {
  	unsigned int i;
  
  	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
  		if (xpermd->driver != node->datum.u.xperms->driver)
  			return;
  	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
  		if (!security_xperm_test(node->datum.u.xperms->perms.p,
  					xpermd->driver))
  			return;
  	} else {
  		BUG();
  	}
  
  	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
  		xpermd->used |= XPERMS_ALLOWED;
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
  			memset(xpermd->allowed->p, 0xff,
  					sizeof(xpermd->allowed->p));
  		}
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
  			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
  				xpermd->allowed->p[i] |=
  					node->datum.u.xperms->perms.p[i];
  		}
  	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
  		xpermd->used |= XPERMS_AUDITALLOW;
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
  			memset(xpermd->auditallow->p, 0xff,
  					sizeof(xpermd->auditallow->p));
  		}
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
  			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
  				xpermd->auditallow->p[i] |=
  					node->datum.u.xperms->perms.p[i];
  		}
  	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
  		xpermd->used |= XPERMS_DONTAUDIT;
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
  			memset(xpermd->dontaudit->p, 0xff,
  					sizeof(xpermd->dontaudit->p));
  		}
  		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
  			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
  				xpermd->dontaudit->p[i] |=
  					node->datum.u.xperms->perms.p[i];
  		}
  	} else {
  		BUG();
  	}
  }
  
  void security_compute_xperms_decision(u32 ssid,
  				u32 tsid,
  				u16 orig_tclass,
  				u8 driver,
  				struct extended_perms_decision *xpermd)
  {
  	u16 tclass;
  	struct context *scontext, *tcontext;
  	struct avtab_key avkey;
  	struct avtab_node *node;
  	struct ebitmap *sattr, *tattr;
  	struct ebitmap_node *snode, *tnode;
  	unsigned int i, j;
  
  	xpermd->driver = driver;
  	xpermd->used = 0;
  	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
  	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
  	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
  
  	read_lock(&policy_rwlock);
  	if (!ss_initialized)
  		goto allow;
  
  	scontext = sidtab_search(&sidtab, ssid);
  	if (!scontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, ssid);
  		goto out;
  	}
  
  	tcontext = sidtab_search(&sidtab, tsid);
  	if (!tcontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, tsid);
  		goto out;
  	}
  
  	tclass = unmap_class(orig_tclass);
  	if (unlikely(orig_tclass && !tclass)) {
  		if (policydb.allow_unknown)
  			goto allow;
  		goto out;
  	}
  
  
  	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
  		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
  		goto out;
  	}
  
  	avkey.target_class = tclass;
  	avkey.specified = AVTAB_XPERMS;
  	sattr = flex_array_get(policydb.type_attr_map_array,
  				scontext->type - 1);
  	BUG_ON(!sattr);
  	tattr = flex_array_get(policydb.type_attr_map_array,
  				tcontext->type - 1);
  	BUG_ON(!tattr);
  	ebitmap_for_each_positive_bit(sattr, snode, i) {
  		ebitmap_for_each_positive_bit(tattr, tnode, j) {
  			avkey.source_type = i + 1;
  			avkey.target_type = j + 1;
  			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
  			     node;
  			     node = avtab_search_node_next(node, avkey.specified))
  				services_compute_xperms_decision(xpermd, node);
  
  			cond_compute_xperms(&policydb.te_cond_avtab,
  						&avkey, xpermd);
  		}
  	}
  out:
  	read_unlock(&policy_rwlock);
  	return;
  allow:
  	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
  	goto out;
  }
  
  /**
   * security_compute_av - Compute access vector decisions.
   * @ssid: source security identifier
   * @tsid: target security identifier
   * @tclass: target security class
   * @avd: access vector decisions
   * @xperms: extended permissions
   *
   * Compute a set of access vector decisions based on the
   * SID pair (@ssid, @tsid) for the permissions in @tclass.
   */
  void security_compute_av(u32 ssid,
  			 u32 tsid,
  			 u16 orig_tclass,
  			 struct av_decision *avd,
  			 struct extended_perms *xperms)
  {
  	u16 tclass;
  	struct context *scontext = NULL, *tcontext = NULL;
  
  	read_lock(&policy_rwlock);
  	avd_init(avd);
  	xperms->len = 0;
  	if (!ss_initialized)
  		goto allow;
  
  	scontext = sidtab_search(&sidtab, ssid);
  	if (!scontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, ssid);
  		goto out;
  	}
  
  	/* permissive domain? */
  	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
  		avd->flags |= AVD_FLAGS_PERMISSIVE;
  
  	tcontext = sidtab_search(&sidtab, tsid);
  	if (!tcontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, tsid);
  		goto out;
  	}
  
  	tclass = unmap_class(orig_tclass);
  	if (unlikely(orig_tclass && !tclass)) {
  		if (policydb.allow_unknown)
  			goto allow;
  		goto out;
  	}
  	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
  	map_decision(orig_tclass, avd, policydb.allow_unknown);
  out:
  	read_unlock(&policy_rwlock);
  	return;
  allow:
  	avd->allowed = 0xffffffff;
  	goto out;
  }
  
  void security_compute_av_user(u32 ssid,
  			      u32 tsid,
  			      u16 tclass,
  			      struct av_decision *avd)
  {
  	struct context *scontext = NULL, *tcontext = NULL;
  
  	read_lock(&policy_rwlock);
  	avd_init(avd);
  	if (!ss_initialized)
  		goto allow;
  
  	scontext = sidtab_search(&sidtab, ssid);
  	if (!scontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, ssid);
  		goto out;
  	}
  
  	/* permissive domain? */
  	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
  		avd->flags |= AVD_FLAGS_PERMISSIVE;
  
  	tcontext = sidtab_search(&sidtab, tsid);
  	if (!tcontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, tsid);
  		goto out;
  	}
  
  	if (unlikely(!tclass)) {
  		if (policydb.allow_unknown)
  			goto allow;
  		goto out;
  	}
  
  	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
   out:
  	read_unlock(&policy_rwlock);
  	return;
  allow:
  	avd->allowed = 0xffffffff;
  	goto out;
  }
  
  /*
   * Write the security context string representation of
   * the context structure `context' into a dynamically
   * allocated string of the correct size.  Set `*scontext'
   * to point to this string and set `*scontext_len' to
   * the length of the string.
   */
  static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
  {
  	char *scontextp;
  
  	if (scontext)
  		*scontext = NULL;
  	*scontext_len = 0;
  
  	if (context->len) {
  		*scontext_len = context->len;
  		if (scontext) {
  			*scontext = kstrdup(context->str, GFP_ATOMIC);
  			if (!(*scontext))
  				return -ENOMEM;
  		}
  		return 0;
  	}
  
  	/* Compute the size of the context. */
  	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
  	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
  	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
  	*scontext_len += mls_compute_context_len(context);
  
  	if (!scontext)
  		return 0;
  
  	/* Allocate space for the context; caller must free this space. */
  	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
  	if (!scontextp)
  		return -ENOMEM;
  	*scontext = scontextp;
  
  	/*
  	 * Copy the user name, role name and type name into the context.
  	 */
  	sprintf(scontextp, "%s:%s:%s",
  		sym_name(&policydb, SYM_USERS, context->user - 1),
  		sym_name(&policydb, SYM_ROLES, context->role - 1),
  		sym_name(&policydb, SYM_TYPES, context->type - 1));
  	scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
  		     1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
  		     1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
  
  	mls_sid_to_context(context, &scontextp);
  
  	*scontextp = 0;
  
  	return 0;
  }
  
  #include "initial_sid_to_string.h"
  
  const char *security_get_initial_sid_context(u32 sid)
  {
  	if (unlikely(sid > SECINITSID_NUM))
  		return NULL;
  	return initial_sid_to_string[sid];
  }
  
  static int security_sid_to_context_core(u32 sid, char **scontext,
  					u32 *scontext_len, int force)
  {
  	struct context *context;
  	int rc = 0;
  
  	if (scontext)
  		*scontext = NULL;
  	*scontext_len  = 0;
  
  	if (!ss_initialized) {
  		if (sid <= SECINITSID_NUM) {
  			char *scontextp;
  
  			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
  			if (!scontext)
  				goto out;
  			scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
  			if (!scontextp) {
  				rc = -ENOMEM;
  				goto out;
  			}
  			strcpy(scontextp, initial_sid_to_string[sid]);
  			*scontext = scontextp;
  			goto out;
  		}
  		printk(KERN_ERR "SELinux: %s:  called before initial "
  		       "load_policy on unknown SID %d\n", __func__, sid);
  		rc = -EINVAL;
  		goto out;
  	}
  	read_lock(&policy_rwlock);
  	if (force)
  		context = sidtab_search_force(&sidtab, sid);
  	else
  		context = sidtab_search(&sidtab, sid);
  	if (!context) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, sid);
  		rc = -EINVAL;
  		goto out_unlock;
  	}
  	rc = context_struct_to_string(context, scontext, scontext_len);
  out_unlock:
  	read_unlock(&policy_rwlock);
  out:
  	return rc;
  
  }
  
  /**
   * security_sid_to_context - Obtain a context for a given SID.
   * @sid: security identifier, SID
   * @scontext: security context
   * @scontext_len: length in bytes
   *
   * Write the string representation of the context associated with @sid
   * into a dynamically allocated string of the correct size.  Set @scontext
   * to point to this string and set @scontext_len to the length of the string.
   */
  int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
  {
  	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
  }
  
  int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
  {
  	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
  }
  
  /*
   * Caveat:  Mutates scontext.
   */
  static int string_to_context_struct(struct policydb *pol,
  				    struct sidtab *sidtabp,
  				    char *scontext,
  				    u32 scontext_len,
  				    struct context *ctx,
  				    u32 def_sid)
  {
  	struct role_datum *role;
  	struct type_datum *typdatum;
  	struct user_datum *usrdatum;
  	char *scontextp, *p, oldc;
  	int rc = 0;
  
  	context_init(ctx);
  
  	/* Parse the security context. */
  
  	rc = -EINVAL;
  	scontextp = (char *) scontext;
  
  	/* Extract the user. */
  	p = scontextp;
  	while (*p && *p != ':')
  		p++;
  
  	if (*p == 0)
  		goto out;
  
  	*p++ = 0;
  
  	usrdatum = hashtab_search(pol->p_users.table, scontextp);
  	if (!usrdatum)
  		goto out;
  
  	ctx->user = usrdatum->value;
  
  	/* Extract role. */
  	scontextp = p;
  	while (*p && *p != ':')
  		p++;
  
  	if (*p == 0)
  		goto out;
  
  	*p++ = 0;
  
  	role = hashtab_search(pol->p_roles.table, scontextp);
  	if (!role)
  		goto out;
  	ctx->role = role->value;
  
  	/* Extract type. */
  	scontextp = p;
  	while (*p && *p != ':')
  		p++;
  	oldc = *p;
  	*p++ = 0;
  
  	typdatum = hashtab_search(pol->p_types.table, scontextp);
  	if (!typdatum || typdatum->attribute)
  		goto out;
  
  	ctx->type = typdatum->value;
  
  	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
  	if (rc)
  		goto out;
  
  	rc = -EINVAL;
  	if ((p - scontext) < scontext_len)
  		goto out;
  
  	/* Check the validity of the new context. */
  	if (!policydb_context_isvalid(pol, ctx))
  		goto out;
  	rc = 0;
  out:
  	if (rc)
  		context_destroy(ctx);
  	return rc;
  }
  
  static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
  					u32 *sid, u32 def_sid, gfp_t gfp_flags,
  					int force)
  {
  	char *scontext2, *str = NULL;
  	struct context context;
  	int rc = 0;
  
  	/* An empty security context is never valid. */
  	if (!scontext_len)
  		return -EINVAL;
  
  	if (!ss_initialized) {
  		int i;
  
  		for (i = 1; i < SECINITSID_NUM; i++) {
  			if (!strcmp(initial_sid_to_string[i], scontext)) {
  				*sid = i;
  				return 0;
  			}
  		}
  		*sid = SECINITSID_KERNEL;
  		return 0;
  	}
  	*sid = SECSID_NULL;
  
  	/* Copy the string so that we can modify the copy as we parse it. */
  	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
  	if (!scontext2)
  		return -ENOMEM;
  	memcpy(scontext2, scontext, scontext_len);
  	scontext2[scontext_len] = 0;
  
  	if (force) {
  		/* Save another copy for storing in uninterpreted form */
  		rc = -ENOMEM;
  		str = kstrdup(scontext2, gfp_flags);
  		if (!str)
  			goto out;
  	}
  
  	read_lock(&policy_rwlock);
  	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
  				      scontext_len, &context, def_sid);
  	if (rc == -EINVAL && force) {
  		context.str = str;
  		context.len = scontext_len;
  		str = NULL;
  	} else if (rc)
  		goto out_unlock;
  	rc = sidtab_context_to_sid(&sidtab, &context, sid);
  	context_destroy(&context);
  out_unlock:
  	read_unlock(&policy_rwlock);
  out:
  	kfree(scontext2);
  	kfree(str);
  	return rc;
  }
  
  /**
   * security_context_to_sid - Obtain a SID for a given security context.
   * @scontext: security context
   * @scontext_len: length in bytes
   * @sid: security identifier, SID
   * @gfp: context for the allocation
   *
   * Obtains a SID associated with the security context that
   * has the string representation specified by @scontext.
   * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
   * memory is available, or 0 on success.
   */
  int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
  			    gfp_t gfp)
  {
  	return security_context_to_sid_core(scontext, scontext_len,
  					    sid, SECSID_NULL, gfp, 0);
  }
  
  /**
   * security_context_to_sid_default - Obtain a SID for a given security context,
   * falling back to specified default if needed.
   *
   * @scontext: security context
   * @scontext_len: length in bytes
   * @sid: security identifier, SID
   * @def_sid: default SID to assign on error
   *
   * Obtains a SID associated with the security context that
   * has the string representation specified by @scontext.
   * The default SID is passed to the MLS layer to be used to allow
   * kernel labeling of the MLS field if the MLS field is not present
   * (for upgrading to MLS without full relabel).
   * Implicitly forces adding of the context even if it cannot be mapped yet.
   * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
   * memory is available, or 0 on success.
   */
  int security_context_to_sid_default(const char *scontext, u32 scontext_len,
  				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
  {
  	return security_context_to_sid_core(scontext, scontext_len,
  					    sid, def_sid, gfp_flags, 1);
  }
  
  int security_context_to_sid_force(const char *scontext, u32 scontext_len,
  				  u32 *sid)
  {
  	return security_context_to_sid_core(scontext, scontext_len,
  					    sid, SECSID_NULL, GFP_KERNEL, 1);
  }
  
  static int compute_sid_handle_invalid_context(
  	struct context *scontext,
  	struct context *tcontext,
  	u16 tclass,
  	struct context *newcontext)
  {
  	char *s = NULL, *t = NULL, *n = NULL;
  	u32 slen, tlen, nlen;
  
  	if (context_struct_to_string(scontext, &s, &slen))
  		goto out;
  	if (context_struct_to_string(tcontext, &t, &tlen))
  		goto out;
  	if (context_struct_to_string(newcontext, &n, &nlen))
  		goto out;
  	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
  		  "op=security_compute_sid invalid_context=%s"
  		  " scontext=%s"
  		  " tcontext=%s"
  		  " tclass=%s",
  		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
  out:
  	kfree(s);
  	kfree(t);
  	kfree(n);
  	if (!selinux_enforcing)
  		return 0;
  	return -EACCES;
  }
  
  static void filename_compute_type(struct policydb *p, struct context *newcontext,
  				  u32 stype, u32 ttype, u16 tclass,
  				  const char *objname)
  {
  	struct filename_trans ft;
  	struct filename_trans_datum *otype;
  
  	/*
  	 * Most filename trans rules are going to live in specific directories
  	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
  	 * if the ttype does not contain any rules.
  	 */
  	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
  		return;
  
  	ft.stype = stype;
  	ft.ttype = ttype;
  	ft.tclass = tclass;
  	ft.name = objname;
  
  	otype = hashtab_search(p->filename_trans, &ft);
  	if (otype)
  		newcontext->type = otype->otype;
  }
  
  static int security_compute_sid(u32 ssid,
  				u32 tsid,
  				u16 orig_tclass,
  				u32 specified,
  				const char *objname,
  				u32 *out_sid,
  				bool kern)
  {
  	struct class_datum *cladatum = NULL;
  	struct context *scontext = NULL, *tcontext = NULL, newcontext;
  	struct role_trans *roletr = NULL;
  	struct avtab_key avkey;
  	struct avtab_datum *avdatum;
  	struct avtab_node *node;
  	u16 tclass;
  	int rc = 0;
  	bool sock;
  
  	if (!ss_initialized) {
  		switch (orig_tclass) {
  		case SECCLASS_PROCESS: /* kernel value */
  			*out_sid = ssid;
  			break;
  		default:
  			*out_sid = tsid;
  			break;
  		}
  		goto out;
  	}
  
  	context_init(&newcontext);
  
  	read_lock(&policy_rwlock);
  
  	if (kern) {
  		tclass = unmap_class(orig_tclass);
  		sock = security_is_socket_class(orig_tclass);
  	} else {
  		tclass = orig_tclass;
  		sock = security_is_socket_class(map_class(tclass));
  	}
  
  	scontext = sidtab_search(&sidtab, ssid);
  	if (!scontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, ssid);
  		rc = -EINVAL;
  		goto out_unlock;
  	}
  	tcontext = sidtab_search(&sidtab, tsid);
  	if (!tcontext) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, tsid);
  		rc = -EINVAL;
  		goto out_unlock;
  	}
  
  	if (tclass && tclass <= policydb.p_classes.nprim)
  		cladatum = policydb.class_val_to_struct[tclass - 1];
  
  	/* Set the user identity. */
  	switch (specified) {
  	case AVTAB_TRANSITION:
  	case AVTAB_CHANGE:
  		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
  			newcontext.user = tcontext->user;
  		} else {
  			/* notice this gets both DEFAULT_SOURCE and unset */
  			/* Use the process user identity. */
  			newcontext.user = scontext->user;
  		}
  		break;
  	case AVTAB_MEMBER:
  		/* Use the related object owner. */
  		newcontext.user = tcontext->user;
  		break;
  	}
  
  	/* Set the role to default values. */
  	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
  		newcontext.role = scontext->role;
  	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
  		newcontext.role = tcontext->role;
  	} else {
  		if ((tclass == policydb.process_class) || (sock == true))
  			newcontext.role = scontext->role;
  		else
  			newcontext.role = OBJECT_R_VAL;
  	}
  
  	/* Set the type to default values. */
  	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
  		newcontext.type = scontext->type;
  	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
  		newcontext.type = tcontext->type;
  	} else {
  		if ((tclass == policydb.process_class) || (sock == true)) {
  			/* Use the type of process. */
  			newcontext.type = scontext->type;
  		} else {
  			/* Use the type of the related object. */
  			newcontext.type = tcontext->type;
  		}
  	}
  
  	/* Look for a type transition/member/change rule. */
  	avkey.source_type = scontext->type;
  	avkey.target_type = tcontext->type;
  	avkey.target_class = tclass;
  	avkey.specified = specified;
  	avdatum = avtab_search(&policydb.te_avtab, &avkey);
  
  	/* If no permanent rule, also check for enabled conditional rules */
  	if (!avdatum) {
  		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
  		for (; node; node = avtab_search_node_next(node, specified)) {
  			if (node->key.specified & AVTAB_ENABLED) {
  				avdatum = &node->datum;
  				break;
  			}
  		}
  	}
  
  	if (avdatum) {
  		/* Use the type from the type transition/member/change rule. */
  		newcontext.type = avdatum->u.data;
  	}
  
  	/* if we have a objname this is a file trans check so check those rules */
  	if (objname)
  		filename_compute_type(&policydb, &newcontext, scontext->type,
  				      tcontext->type, tclass, objname);
  
  	/* Check for class-specific changes. */
  	if (specified & AVTAB_TRANSITION) {
  		/* Look for a role transition rule. */
  		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
  			if ((roletr->role == scontext->role) &&
  			    (roletr->type == tcontext->type) &&
  			    (roletr->tclass == tclass)) {
  				/* Use the role transition rule. */
  				newcontext.role = roletr->new_role;
  				break;
  			}
  		}
  	}
  
  	/* Set the MLS attributes.
  	   This is done last because it may allocate memory. */
  	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
  			     &newcontext, sock);
  	if (rc)
  		goto out_unlock;
  
  	/* Check the validity of the context. */
  	if (!policydb_context_isvalid(&policydb, &newcontext)) {
  		rc = compute_sid_handle_invalid_context(scontext,
  							tcontext,
  							tclass,
  							&newcontext);
  		if (rc)
  			goto out_unlock;
  	}
  	/* Obtain the sid for the context. */
  	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
  out_unlock:
  	read_unlock(&policy_rwlock);
  	context_destroy(&newcontext);
  out:
  	return rc;
  }
  
  /**
   * security_transition_sid - Compute the SID for a new subject/object.
   * @ssid: source security identifier
   * @tsid: target security identifier
   * @tclass: target security class
   * @out_sid: security identifier for new subject/object
   *
   * Compute a SID to use for labeling a new subject or object in the
   * class @tclass based on a SID pair (@ssid, @tsid).
   * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
   * if insufficient memory is available, or %0 if the new SID was
   * computed successfully.
   */
  int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
  			    const struct qstr *qstr, u32 *out_sid)
  {
  	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
  				    qstr ? qstr->name : NULL, out_sid, true);
  }
  
  int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
  				 const char *objname, u32 *out_sid)
  {
  	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
  				    objname, out_sid, false);
  }
  
  /**
   * security_member_sid - Compute the SID for member selection.
   * @ssid: source security identifier
   * @tsid: target security identifier
   * @tclass: target security class
   * @out_sid: security identifier for selected member
   *
   * Compute a SID to use when selecting a member of a polyinstantiated
   * object of class @tclass based on a SID pair (@ssid, @tsid).
   * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
   * if insufficient memory is available, or %0 if the SID was
   * computed successfully.
   */
  int security_member_sid(u32 ssid,
  			u32 tsid,
  			u16 tclass,
  			u32 *out_sid)
  {
  	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
  				    out_sid, false);
  }
  
  /**
   * security_change_sid - Compute the SID for object relabeling.
   * @ssid: source security identifier
   * @tsid: target security identifier
   * @tclass: target security class
   * @out_sid: security identifier for selected member
   *
   * Compute a SID to use for relabeling an object of class @tclass
   * based on a SID pair (@ssid, @tsid).
   * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
   * if insufficient memory is available, or %0 if the SID was
   * computed successfully.
   */
  int security_change_sid(u32 ssid,
  			u32 tsid,
  			u16 tclass,
  			u32 *out_sid)
  {
  	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
  				    out_sid, false);
  }
  
  /* Clone the SID into the new SID table. */
  static int clone_sid(u32 sid,
  		     struct context *context,
  		     void *arg)
  {
  	struct sidtab *s = arg;
  
  	if (sid > SECINITSID_NUM)
  		return sidtab_insert(s, sid, context);
  	else
  		return 0;
  }
  
  static inline int convert_context_handle_invalid_context(struct context *context)
  {
  	char *s;
  	u32 len;
  
  	if (selinux_enforcing)
  		return -EINVAL;
  
  	if (!context_struct_to_string(context, &s, &len)) {
  		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
  		kfree(s);
  	}
  	return 0;
  }
  
  struct convert_context_args {
  	struct policydb *oldp;
  	struct policydb *newp;
  };
  
  /*
   * Convert the values in the security context
   * structure `c' from the values specified
   * in the policy `p->oldp' to the values specified
   * in the policy `p->newp'.  Verify that the
   * context is valid under the new policy.
   */
  static int convert_context(u32 key,
  			   struct context *c,
  			   void *p)
  {
  	struct convert_context_args *args;
  	struct context oldc;
  	struct ocontext *oc;
  	struct mls_range *range;
  	struct role_datum *role;
  	struct type_datum *typdatum;
  	struct user_datum *usrdatum;
  	char *s;
  	u32 len;
  	int rc = 0;
  
  	if (key <= SECINITSID_NUM)
  		goto out;
  
  	args = p;
  
  	if (c->str) {
  		struct context ctx;
  
  		rc = -ENOMEM;
  		s = kstrdup(c->str, GFP_KERNEL);
  		if (!s)
  			goto out;
  
  		rc = string_to_context_struct(args->newp, NULL, s,
  					      c->len, &ctx, SECSID_NULL);
  		kfree(s);
  		if (!rc) {
  			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
  			       c->str);
  			/* Replace string with mapped representation. */
  			kfree(c->str);
  			memcpy(c, &ctx, sizeof(*c));
  			goto out;
  		} else if (rc == -EINVAL) {
  			/* Retain string representation for later mapping. */
  			rc = 0;
  			goto out;
  		} else {
  			/* Other error condition, e.g. ENOMEM. */
  			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
  			       c->str, -rc);
  			goto out;
  		}
  	}
  
  	rc = context_cpy(&oldc, c);
  	if (rc)
  		goto out;
  
  	/* Convert the user. */
  	rc = -EINVAL;
  	usrdatum = hashtab_search(args->newp->p_users.table,
  				  sym_name(args->oldp, SYM_USERS, c->user - 1));
  	if (!usrdatum)
  		goto bad;
  	c->user = usrdatum->value;
  
  	/* Convert the role. */
  	rc = -EINVAL;
  	role = hashtab_search(args->newp->p_roles.table,
  			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
  	if (!role)
  		goto bad;
  	c->role = role->value;
  
  	/* Convert the type. */
  	rc = -EINVAL;
  	typdatum = hashtab_search(args->newp->p_types.table,
  				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
  	if (!typdatum)
  		goto bad;
  	c->type = typdatum->value;
  
  	/* Convert the MLS fields if dealing with MLS policies */
  	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
  		rc = mls_convert_context(args->oldp, args->newp, c);
  		if (rc)
  			goto bad;
  	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
  		/*
  		 * Switching between MLS and non-MLS policy:
  		 * free any storage used by the MLS fields in the
  		 * context for all existing entries in the sidtab.
  		 */
  		mls_context_destroy(c);
  	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
  		/*
  		 * Switching between non-MLS and MLS policy:
  		 * ensure that the MLS fields of the context for all
  		 * existing entries in the sidtab are filled in with a
  		 * suitable default value, likely taken from one of the
  		 * initial SIDs.
  		 */
  		oc = args->newp->ocontexts[OCON_ISID];
  		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
  			oc = oc->next;
  		rc = -EINVAL;
  		if (!oc) {
  			printk(KERN_ERR "SELinux:  unable to look up"
  				" the initial SIDs list\n");
  			goto bad;
  		}
  		range = &oc->context[0].range;
  		rc = mls_range_set(c, range);
  		if (rc)
  			goto bad;
  	}
  
  	/* Check the validity of the new context. */
  	if (!policydb_context_isvalid(args->newp, c)) {
  		rc = convert_context_handle_invalid_context(&oldc);
  		if (rc)
  			goto bad;
  	}
  
  	context_destroy(&oldc);
  
  	rc = 0;
  out:
  	return rc;
  bad:
  	/* Map old representation to string and save it. */
  	rc = context_struct_to_string(&oldc, &s, &len);
  	if (rc)
  		return rc;
  	context_destroy(&oldc);
  	context_destroy(c);
  	c->str = s;
  	c->len = len;
  	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
  	       c->str);
  	rc = 0;
  	goto out;
  }
  
  static void security_load_policycaps(void)
  {
  	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
  						  POLICYDB_CAPABILITY_NETPEER);
  	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
  						  POLICYDB_CAPABILITY_OPENPERM);
  	selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
  						  POLICYDB_CAPABILITY_ALWAYSNETWORK);
  }
  
  static int security_preserve_bools(struct policydb *p);
  
  /**
   * security_load_policy - Load a security policy configuration.
   * @data: binary policy data
   * @len: length of data in bytes
   *
   * Load a new set of security policy configuration data,
   * validate it and convert the SID table as necessary.
   * This function will flush the access vector cache after
   * loading the new policy.
   */
  int security_load_policy(void *data, size_t len)
  {
  	struct policydb *oldpolicydb, *newpolicydb;
  	struct sidtab oldsidtab, newsidtab;
  	struct selinux_mapping *oldmap, *map = NULL;
  	struct convert_context_args args;
  	u32 seqno;
  	u16 map_size;
  	int rc = 0;
  	struct policy_file file = { data, len }, *fp = &file;
  
  	oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
  	if (!oldpolicydb) {
  		rc = -ENOMEM;
  		goto out;
  	}
  	newpolicydb = oldpolicydb + 1;
  
  	if (!ss_initialized) {
  		avtab_cache_init();
  		rc = policydb_read(&policydb, fp);
  		if (rc) {
  			avtab_cache_destroy();
  			goto out;
  		}
  
  		policydb.len = len;
  		rc = selinux_set_mapping(&policydb, secclass_map,
  					 &current_mapping,
  					 &current_mapping_size);
  		if (rc) {
  			policydb_destroy(&policydb);
  			avtab_cache_destroy();
  			goto out;
  		}
  
  		rc = policydb_load_isids(&policydb, &sidtab);
  		if (rc) {
  			policydb_destroy(&policydb);
  			avtab_cache_destroy();
  			goto out;
  		}
  
  		security_load_policycaps();
  		ss_initialized = 1;
  		seqno = ++latest_granting;
  		selinux_complete_init();
  		avc_ss_reset(seqno);
  		selnl_notify_policyload(seqno);
  		selinux_status_update_policyload(seqno);
  		selinux_netlbl_cache_invalidate();
  		selinux_xfrm_notify_policyload();
  		goto out;
  	}
  
  #if 0
  	sidtab_hash_eval(&sidtab, "sids");
  #endif
  
  	rc = policydb_read(newpolicydb, fp);
  	if (rc)
  		goto out;
  
  	newpolicydb->len = len;
  	/* If switching between different policy types, log MLS status */
  	if (policydb.mls_enabled && !newpolicydb->mls_enabled)
  		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
  	else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
  		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
  
  	rc = policydb_load_isids(newpolicydb, &newsidtab);
  	if (rc) {
  		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
  		policydb_destroy(newpolicydb);
  		goto out;
  	}
  
  	rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
  	if (rc)
  		goto err;
  
  	rc = security_preserve_bools(newpolicydb);
  	if (rc) {
  		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
  		goto err;
  	}
  
  	/* Clone the SID table. */
  	sidtab_shutdown(&sidtab);
  
  	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
  	if (rc)
  		goto err;
  
  	/*
  	 * Convert the internal representations of contexts
  	 * in the new SID table.
  	 */
  	args.oldp = &policydb;
  	args.newp = newpolicydb;
  	rc = sidtab_map(&newsidtab, convert_context, &args);
  	if (rc) {
  		printk(KERN_ERR "SELinux:  unable to convert the internal"
  			" representation of contexts in the new SID"
  			" table\n");
  		goto err;
  	}
  
  	/* Save the old policydb and SID table to free later. */
  	memcpy(oldpolicydb, &policydb, sizeof(policydb));
  	sidtab_set(&oldsidtab, &sidtab);
  
  	/* Install the new policydb and SID table. */
  	write_lock_irq(&policy_rwlock);
  	memcpy(&policydb, newpolicydb, sizeof(policydb));
  	sidtab_set(&sidtab, &newsidtab);
  	security_load_policycaps();
  	oldmap = current_mapping;
  	current_mapping = map;
  	current_mapping_size = map_size;
  	seqno = ++latest_granting;
  	write_unlock_irq(&policy_rwlock);
  
  	/* Free the old policydb and SID table. */
  	policydb_destroy(oldpolicydb);
  	sidtab_destroy(&oldsidtab);
  	kfree(oldmap);
  
  	avc_ss_reset(seqno);
  	selnl_notify_policyload(seqno);
  	selinux_status_update_policyload(seqno);
  	selinux_netlbl_cache_invalidate();
  	selinux_xfrm_notify_policyload();
  
  	rc = 0;
  	goto out;
  
  err:
  	kfree(map);
  	sidtab_destroy(&newsidtab);
  	policydb_destroy(newpolicydb);
  
  out:
  	kfree(oldpolicydb);
  	return rc;
  }
  
  size_t security_policydb_len(void)
  {
  	size_t len;
  
  	read_lock(&policy_rwlock);
  	len = policydb.len;
  	read_unlock(&policy_rwlock);
  
  	return len;
  }
  
  /**
   * security_port_sid - Obtain the SID for a port.
   * @protocol: protocol number
   * @port: port number
   * @out_sid: security identifier
   */
  int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
  {
  	struct ocontext *c;
  	int rc = 0;
  
  	read_lock(&policy_rwlock);
  
  	c = policydb.ocontexts[OCON_PORT];
  	while (c) {
  		if (c->u.port.protocol == protocol &&
  		    c->u.port.low_port <= port &&
  		    c->u.port.high_port >= port)
  			break;
  		c = c->next;
  	}
  
  	if (c) {
  		if (!c->sid[0]) {
  			rc = sidtab_context_to_sid(&sidtab,
  						   &c->context[0],
  						   &c->sid[0]);
  			if (rc)
  				goto out;
  		}
  		*out_sid = c->sid[0];
  	} else {
  		*out_sid = SECINITSID_PORT;
  	}
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  /**
   * security_netif_sid - Obtain the SID for a network interface.
   * @name: interface name
   * @if_sid: interface SID
   */
  int security_netif_sid(char *name, u32 *if_sid)
  {
  	int rc = 0;
  	struct ocontext *c;
  
  	read_lock(&policy_rwlock);
  
  	c = policydb.ocontexts[OCON_NETIF];
  	while (c) {
  		if (strcmp(name, c->u.name) == 0)
  			break;
  		c = c->next;
  	}
  
  	if (c) {
  		if (!c->sid[0] || !c->sid[1]) {
  			rc = sidtab_context_to_sid(&sidtab,
  						  &c->context[0],
  						  &c->sid[0]);
  			if (rc)
  				goto out;
  			rc = sidtab_context_to_sid(&sidtab,
  						   &c->context[1],
  						   &c->sid[1]);
  			if (rc)
  				goto out;
  		}
  		*if_sid = c->sid[0];
  	} else
  		*if_sid = SECINITSID_NETIF;
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
  {
  	int i, fail = 0;
  
  	for (i = 0; i < 4; i++)
  		if (addr[i] != (input[i] & mask[i])) {
  			fail = 1;
  			break;
  		}
  
  	return !fail;
  }
  
  /**
   * security_node_sid - Obtain the SID for a node (host).
   * @domain: communication domain aka address family
   * @addrp: address
   * @addrlen: address length in bytes
   * @out_sid: security identifier
   */
  int security_node_sid(u16 domain,
  		      void *addrp,
  		      u32 addrlen,
  		      u32 *out_sid)
  {
  	int rc;
  	struct ocontext *c;
  
  	read_lock(&policy_rwlock);
  
  	switch (domain) {
  	case AF_INET: {
  		u32 addr;
  
  		rc = -EINVAL;
  		if (addrlen != sizeof(u32))
  			goto out;
  
  		addr = *((u32 *)addrp);
  
  		c = policydb.ocontexts[OCON_NODE];
  		while (c) {
  			if (c->u.node.addr == (addr & c->u.node.mask))
  				break;
  			c = c->next;
  		}
  		break;
  	}
  
  	case AF_INET6:
  		rc = -EINVAL;
  		if (addrlen != sizeof(u64) * 2)
  			goto out;
  		c = policydb.ocontexts[OCON_NODE6];
  		while (c) {
  			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
  						c->u.node6.mask))
  				break;
  			c = c->next;
  		}
  		break;
  
  	default:
  		rc = 0;
  		*out_sid = SECINITSID_NODE;
  		goto out;
  	}
  
  	if (c) {
  		if (!c->sid[0]) {
  			rc = sidtab_context_to_sid(&sidtab,
  						   &c->context[0],
  						   &c->sid[0]);
  			if (rc)
  				goto out;
  		}
  		*out_sid = c->sid[0];
  	} else {
  		*out_sid = SECINITSID_NODE;
  	}
  
  	rc = 0;
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  #define SIDS_NEL 25
  
  /**
   * security_get_user_sids - Obtain reachable SIDs for a user.
   * @fromsid: starting SID
   * @username: username
   * @sids: array of reachable SIDs for user
   * @nel: number of elements in @sids
   *
   * Generate the set of SIDs for legal security contexts
   * for a given user that can be reached by @fromsid.
   * Set *@sids to point to a dynamically allocated
   * array containing the set of SIDs.  Set *@nel to the
   * number of elements in the array.
   */
  
  int security_get_user_sids(u32 fromsid,
  			   char *username,
  			   u32 **sids,
  			   u32 *nel)
  {
  	struct context *fromcon, usercon;
  	u32 *mysids = NULL, *mysids2, sid;
  	u32 mynel = 0, maxnel = SIDS_NEL;
  	struct user_datum *user;
  	struct role_datum *role;
  	struct ebitmap_node *rnode, *tnode;
  	int rc = 0, i, j;
  
  	*sids = NULL;
  	*nel = 0;
  
  	if (!ss_initialized)
  		goto out;
  
  	read_lock(&policy_rwlock);
  
  	context_init(&usercon);
  
  	rc = -EINVAL;
  	fromcon = sidtab_search(&sidtab, fromsid);
  	if (!fromcon)
  		goto out_unlock;
  
  	rc = -EINVAL;
  	user = hashtab_search(policydb.p_users.table, username);
  	if (!user)
  		goto out_unlock;
  
  	usercon.user = user->value;
  
  	rc = -ENOMEM;
  	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
  	if (!mysids)
  		goto out_unlock;
  
  	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
  		role = policydb.role_val_to_struct[i];
  		usercon.role = i + 1;
  		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
  			usercon.type = j + 1;
  
  			if (mls_setup_user_range(fromcon, user, &usercon))
  				continue;
  
  			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
  			if (rc)
  				goto out_unlock;
  			if (mynel < maxnel) {
  				mysids[mynel++] = sid;
  			} else {
  				rc = -ENOMEM;
  				maxnel += SIDS_NEL;
  				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
  				if (!mysids2)
  					goto out_unlock;
  				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
  				kfree(mysids);
  				mysids = mysids2;
  				mysids[mynel++] = sid;
  			}
  		}
  	}
  	rc = 0;
  out_unlock:
  	read_unlock(&policy_rwlock);
  	if (rc || !mynel) {
  		kfree(mysids);
  		goto out;
  	}
  
  	rc = -ENOMEM;
  	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
  	if (!mysids2) {
  		kfree(mysids);
  		goto out;
  	}
  	for (i = 0, j = 0; i < mynel; i++) {
  		struct av_decision dummy_avd;
  		rc = avc_has_perm_noaudit(fromsid, mysids[i],
  					  SECCLASS_PROCESS, /* kernel value */
  					  PROCESS__TRANSITION, AVC_STRICT,
  					  &dummy_avd);
  		if (!rc)
  			mysids2[j++] = mysids[i];
  		cond_resched();
  	}
  	rc = 0;
  	kfree(mysids);
  	*sids = mysids2;
  	*nel = j;
  out:
  	return rc;
  }
  
  /**
   * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
   * @fstype: filesystem type
   * @path: path from root of mount
   * @sclass: file security class
   * @sid: SID for path
   *
   * Obtain a SID to use for a file in a filesystem that
   * cannot support xattr or use a fixed labeling behavior like
   * transition SIDs or task SIDs.
   *
   * The caller must acquire the policy_rwlock before calling this function.
   */
  static inline int __security_genfs_sid(const char *fstype,
  				       char *path,
  				       u16 orig_sclass,
  				       u32 *sid)
  {
  	int len;
  	u16 sclass;
  	struct genfs *genfs;
  	struct ocontext *c;
  	int rc, cmp = 0;
  
  	while (path[0] == '/' && path[1] == '/')
  		path++;
  
  	sclass = unmap_class(orig_sclass);
  	*sid = SECINITSID_UNLABELED;
  
  	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
  		cmp = strcmp(fstype, genfs->fstype);
  		if (cmp <= 0)
  			break;
  	}
  
  	rc = -ENOENT;
  	if (!genfs || cmp)
  		goto out;
  
  	for (c = genfs->head; c; c = c->next) {
  		len = strlen(c->u.name);
  		if ((!c->v.sclass || sclass == c->v.sclass) &&
  		    (strncmp(c->u.name, path, len) == 0))
  			break;
  	}
  
  	rc = -ENOENT;
  	if (!c)
  		goto out;
  
  	if (!c->sid[0]) {
  		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
  		if (rc)
  			goto out;
  	}
  
  	*sid = c->sid[0];
  	rc = 0;
  out:
  	return rc;
  }
  
  /**
   * security_genfs_sid - Obtain a SID for a file in a filesystem
   * @fstype: filesystem type
   * @path: path from root of mount
   * @sclass: file security class
   * @sid: SID for path
   *
   * Acquire policy_rwlock before calling __security_genfs_sid() and release
   * it afterward.
   */
  int security_genfs_sid(const char *fstype,
  		       char *path,
  		       u16 orig_sclass,
  		       u32 *sid)
  {
  	int retval;
  
  	read_lock(&policy_rwlock);
  	retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
  	read_unlock(&policy_rwlock);
  	return retval;
  }
  
  /**
   * security_fs_use - Determine how to handle labeling for a filesystem.
   * @sb: superblock in question
   */
  int security_fs_use(struct super_block *sb)
  {
  	int rc = 0;
  	struct ocontext *c;
  	struct superblock_security_struct *sbsec = sb->s_security;
  	const char *fstype = sb->s_type->name;
  
  	read_lock(&policy_rwlock);
  
  	c = policydb.ocontexts[OCON_FSUSE];
  	while (c) {
  		if (strcmp(fstype, c->u.name) == 0)
  			break;
  		c = c->next;
  	}
  
  	if (c) {
  		sbsec->behavior = c->v.behavior;
  		if (!c->sid[0]) {
  			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
  						   &c->sid[0]);
  			if (rc)
  				goto out;
  		}
  		sbsec->sid = c->sid[0];
  	} else {
  		rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
  					  &sbsec->sid);
  		if (rc) {
  			sbsec->behavior = SECURITY_FS_USE_NONE;
  			rc = 0;
  		} else {
  			sbsec->behavior = SECURITY_FS_USE_GENFS;
  		}
  	}
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  int security_get_bools(int *len, char ***names, int **values)
  {
  	int i, rc;
  
  	read_lock(&policy_rwlock);
  	*names = NULL;
  	*values = NULL;
  
  	rc = 0;
  	*len = policydb.p_bools.nprim;
  	if (!*len)
  		goto out;
  
  	rc = -ENOMEM;
  	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
  	if (!*names)
  		goto err;
  
  	rc = -ENOMEM;
  	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
  	if (!*values)
  		goto err;
  
  	for (i = 0; i < *len; i++) {
  		size_t name_len;
  
  		(*values)[i] = policydb.bool_val_to_struct[i]->state;
  		name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
  
  		rc = -ENOMEM;
  		(*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
  		if (!(*names)[i])
  			goto err;
  
  		strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
  		(*names)[i][name_len - 1] = 0;
  	}
  	rc = 0;
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  err:
  	if (*names) {
  		for (i = 0; i < *len; i++)
  			kfree((*names)[i]);
  	}
  	kfree(*values);
  	goto out;
  }
  
  
  int security_set_bools(int len, int *values)
  {
  	int i, rc;
  	int lenp, seqno = 0;
  	struct cond_node *cur;
  
  	write_lock_irq(&policy_rwlock);
  
  	rc = -EFAULT;
  	lenp = policydb.p_bools.nprim;
  	if (len != lenp)
  		goto out;
  
  	for (i = 0; i < len; i++) {
  		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
  			audit_log(current->audit_context, GFP_ATOMIC,
  				AUDIT_MAC_CONFIG_CHANGE,
  				"bool=%s val=%d old_val=%d auid=%u ses=%u",
  				sym_name(&policydb, SYM_BOOLS, i),
  				!!values[i],
  				policydb.bool_val_to_struct[i]->state,
  				from_kuid(&init_user_ns, audit_get_loginuid(current)),
  				audit_get_sessionid(current));
  		}
  		if (values[i])
  			policydb.bool_val_to_struct[i]->state = 1;
  		else
  			policydb.bool_val_to_struct[i]->state = 0;
  	}
  
  	for (cur = policydb.cond_list; cur; cur = cur->next) {
  		rc = evaluate_cond_node(&policydb, cur);
  		if (rc)
  			goto out;
  	}
  
  	seqno = ++latest_granting;
  	rc = 0;
  out:
  	write_unlock_irq(&policy_rwlock);
  	if (!rc) {
  		avc_ss_reset(seqno);
  		selnl_notify_policyload(seqno);
  		selinux_status_update_policyload(seqno);
  		selinux_xfrm_notify_policyload();
  	}
  	return rc;
  }
  
  int security_get_bool_value(int bool)
  {
  	int rc;
  	int len;
  
  	read_lock(&policy_rwlock);
  
  	rc = -EFAULT;
  	len = policydb.p_bools.nprim;
  	if (bool >= len)
  		goto out;
  
  	rc = policydb.bool_val_to_struct[bool]->state;
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  static int security_preserve_bools(struct policydb *p)
  {
  	int rc, nbools = 0, *bvalues = NULL, i;
  	char **bnames = NULL;
  	struct cond_bool_datum *booldatum;
  	struct cond_node *cur;
  
  	rc = security_get_bools(&nbools, &bnames, &bvalues);
  	if (rc)
  		goto out;
  	for (i = 0; i < nbools; i++) {
  		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
  		if (booldatum)
  			booldatum->state = bvalues[i];
  	}
  	for (cur = p->cond_list; cur; cur = cur->next) {
  		rc = evaluate_cond_node(p, cur);
  		if (rc)
  			goto out;
  	}
  
  out:
  	if (bnames) {
  		for (i = 0; i < nbools; i++)
  			kfree(bnames[i]);
  	}
  	kfree(bnames);
  	kfree(bvalues);
  	return rc;
  }
  
  /*
   * security_sid_mls_copy() - computes a new sid based on the given
   * sid and the mls portion of mls_sid.
   */
  int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
  {
  	struct context *context1;
  	struct context *context2;
  	struct context newcon;
  	char *s;
  	u32 len;
  	int rc;
  
  	rc = 0;
  	if (!ss_initialized || !policydb.mls_enabled) {
  		*new_sid = sid;
  		goto out;
  	}
  
  	context_init(&newcon);
  
  	read_lock(&policy_rwlock);
  
  	rc = -EINVAL;
  	context1 = sidtab_search(&sidtab, sid);
  	if (!context1) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, sid);
  		goto out_unlock;
  	}
  
  	rc = -EINVAL;
  	context2 = sidtab_search(&sidtab, mls_sid);
  	if (!context2) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  			__func__, mls_sid);
  		goto out_unlock;
  	}
  
  	newcon.user = context1->user;
  	newcon.role = context1->role;
  	newcon.type = context1->type;
  	rc = mls_context_cpy(&newcon, context2);
  	if (rc)
  		goto out_unlock;
  
  	/* Check the validity of the new context. */
  	if (!policydb_context_isvalid(&policydb, &newcon)) {
  		rc = convert_context_handle_invalid_context(&newcon);
  		if (rc) {
  			if (!context_struct_to_string(&newcon, &s, &len)) {
  				audit_log(current->audit_context,
  					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
  					  "op=security_sid_mls_copy "
  					  "invalid_context=%s", s);
  				kfree(s);
  			}
  			goto out_unlock;
  		}
  	}
  
  	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
  out_unlock:
  	read_unlock(&policy_rwlock);
  	context_destroy(&newcon);
  out:
  	return rc;
  }
  
  /**
   * security_net_peersid_resolve - Compare and resolve two network peer SIDs
   * @nlbl_sid: NetLabel SID
   * @nlbl_type: NetLabel labeling protocol type
   * @xfrm_sid: XFRM SID
   *
   * Description:
   * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
   * resolved into a single SID it is returned via @peer_sid and the function
   * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
   * returns a negative value.  A table summarizing the behavior is below:
   *
   *                                 | function return |      @sid
   *   ------------------------------+-----------------+-----------------
   *   no peer labels                |        0        |    SECSID_NULL
   *   single peer label             |        0        |    <peer_label>
   *   multiple, consistent labels   |        0        |    <peer_label>
   *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
   *
   */
  int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
  				 u32 xfrm_sid,
  				 u32 *peer_sid)
  {
  	int rc;
  	struct context *nlbl_ctx;
  	struct context *xfrm_ctx;
  
  	*peer_sid = SECSID_NULL;
  
  	/* handle the common (which also happens to be the set of easy) cases
  	 * right away, these two if statements catch everything involving a
  	 * single or absent peer SID/label */
  	if (xfrm_sid == SECSID_NULL) {
  		*peer_sid = nlbl_sid;
  		return 0;
  	}
  	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
  	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
  	 * is present */
  	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
  		*peer_sid = xfrm_sid;
  		return 0;
  	}
  
  	/* we don't need to check ss_initialized here since the only way both
  	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
  	 * security server was initialized and ss_initialized was true */
  	if (!policydb.mls_enabled)
  		return 0;
  
  	read_lock(&policy_rwlock);
  
  	rc = -EINVAL;
  	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
  	if (!nlbl_ctx) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, nlbl_sid);
  		goto out;
  	}
  	rc = -EINVAL;
  	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
  	if (!xfrm_ctx) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
  		       __func__, xfrm_sid);
  		goto out;
  	}
  	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
  	if (rc)
  		goto out;
  
  	/* at present NetLabel SIDs/labels really only carry MLS
  	 * information so if the MLS portion of the NetLabel SID
  	 * matches the MLS portion of the labeled XFRM SID/label
  	 * then pass along the XFRM SID as it is the most
  	 * expressive */
  	*peer_sid = xfrm_sid;
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  static int get_classes_callback(void *k, void *d, void *args)
  {
  	struct class_datum *datum = d;
  	char *name = k, **classes = args;
  	int value = datum->value - 1;
  
  	classes[value] = kstrdup(name, GFP_ATOMIC);
  	if (!classes[value])
  		return -ENOMEM;
  
  	return 0;
  }
  
  int security_get_classes(char ***classes, int *nclasses)
  {
  	int rc;
  
  	read_lock(&policy_rwlock);
  
  	rc = -ENOMEM;
  	*nclasses = policydb.p_classes.nprim;
  	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
  	if (!*classes)
  		goto out;
  
  	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
  			*classes);
  	if (rc) {
  		int i;
  		for (i = 0; i < *nclasses; i++)
  			kfree((*classes)[i]);
  		kfree(*classes);
  	}
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  static int get_permissions_callback(void *k, void *d, void *args)
  {
  	struct perm_datum *datum = d;
  	char *name = k, **perms = args;
  	int value = datum->value - 1;
  
  	perms[value] = kstrdup(name, GFP_ATOMIC);
  	if (!perms[value])
  		return -ENOMEM;
  
  	return 0;
  }
  
  int security_get_permissions(char *class, char ***perms, int *nperms)
  {
  	int rc, i;
  	struct class_datum *match;
  
  	read_lock(&policy_rwlock);
  
  	rc = -EINVAL;
  	match = hashtab_search(policydb.p_classes.table, class);
  	if (!match) {
  		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
  			__func__, class);
  		goto out;
  	}
  
  	rc = -ENOMEM;
  	*nperms = match->permissions.nprim;
  	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
  	if (!*perms)
  		goto out;
  
  	if (match->comdatum) {
  		rc = hashtab_map(match->comdatum->permissions.table,
  				get_permissions_callback, *perms);
  		if (rc)
  			goto err;
  	}
  
  	rc = hashtab_map(match->permissions.table, get_permissions_callback,
  			*perms);
  	if (rc)
  		goto err;
  
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  
  err:
  	read_unlock(&policy_rwlock);
  	for (i = 0; i < *nperms; i++)
  		kfree((*perms)[i]);
  	kfree(*perms);
  	return rc;
  }
  
  int security_get_reject_unknown(void)
  {
  	return policydb.reject_unknown;
  }
  
  int security_get_allow_unknown(void)
  {
  	return policydb.allow_unknown;
  }
  
  /**
   * security_policycap_supported - Check for a specific policy capability
   * @req_cap: capability
   *
   * Description:
   * This function queries the currently loaded policy to see if it supports the
   * capability specified by @req_cap.  Returns true (1) if the capability is
   * supported, false (0) if it isn't supported.
   *
   */
  int security_policycap_supported(unsigned int req_cap)
  {
  	int rc;
  
  	read_lock(&policy_rwlock);
  	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
  	read_unlock(&policy_rwlock);
  
  	return rc;
  }
  
  struct selinux_audit_rule {
  	u32 au_seqno;
  	struct context au_ctxt;
  };
  
  void selinux_audit_rule_free(void *vrule)
  {
  	struct selinux_audit_rule *rule = vrule;
  
  	if (rule) {
  		context_destroy(&rule->au_ctxt);
  		kfree(rule);
  	}
  }
  
  int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
  {
  	struct selinux_audit_rule *tmprule;
  	struct role_datum *roledatum;
  	struct type_datum *typedatum;
  	struct user_datum *userdatum;
  	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
  	int rc = 0;
  
  	*rule = NULL;
  
  	if (!ss_initialized)
  		return -EOPNOTSUPP;
  
  	switch (field) {
  	case AUDIT_SUBJ_USER:
  	case AUDIT_SUBJ_ROLE:
  	case AUDIT_SUBJ_TYPE:
  	case AUDIT_OBJ_USER:
  	case AUDIT_OBJ_ROLE:
  	case AUDIT_OBJ_TYPE:
  		/* only 'equals' and 'not equals' fit user, role, and type */
  		if (op != Audit_equal && op != Audit_not_equal)
  			return -EINVAL;
  		break;
  	case AUDIT_SUBJ_SEN:
  	case AUDIT_SUBJ_CLR:
  	case AUDIT_OBJ_LEV_LOW:
  	case AUDIT_OBJ_LEV_HIGH:
  		/* we do not allow a range, indicated by the presence of '-' */
  		if (strchr(rulestr, '-'))
  			return -EINVAL;
  		break;
  	default:
  		/* only the above fields are valid */
  		return -EINVAL;
  	}
  
  	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
  	if (!tmprule)
  		return -ENOMEM;
  
  	context_init(&tmprule->au_ctxt);
  
  	read_lock(&policy_rwlock);
  
  	tmprule->au_seqno = latest_granting;
  
  	switch (field) {
  	case AUDIT_SUBJ_USER:
  	case AUDIT_OBJ_USER:
  		rc = -EINVAL;
  		userdatum = hashtab_search(policydb.p_users.table, rulestr);
  		if (!userdatum)
  			goto out;
  		tmprule->au_ctxt.user = userdatum->value;
  		break;
  	case AUDIT_SUBJ_ROLE:
  	case AUDIT_OBJ_ROLE:
  		rc = -EINVAL;
  		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
  		if (!roledatum)
  			goto out;
  		tmprule->au_ctxt.role = roledatum->value;
  		break;
  	case AUDIT_SUBJ_TYPE:
  	case AUDIT_OBJ_TYPE:
  		rc = -EINVAL;
  		typedatum = hashtab_search(policydb.p_types.table, rulestr);
  		if (!typedatum)
  			goto out;
  		tmprule->au_ctxt.type = typedatum->value;
  		break;
  	case AUDIT_SUBJ_SEN:
  	case AUDIT_SUBJ_CLR:
  	case AUDIT_OBJ_LEV_LOW:
  	case AUDIT_OBJ_LEV_HIGH:
  		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
  		if (rc)
  			goto out;
  		break;
  	}
  	rc = 0;
  out:
  	read_unlock(&policy_rwlock);
  
  	if (rc) {
  		selinux_audit_rule_free(tmprule);
  		tmprule = NULL;
  	}
  
  	*rule = tmprule;
  
  	return rc;
  }
  
  /* Check to see if the rule contains any selinux fields */
  int selinux_audit_rule_known(struct audit_krule *rule)
  {
  	int i;
  
  	for (i = 0; i < rule->field_count; i++) {
  		struct audit_field *f = &rule->fields[i];
  		switch (f->type) {
  		case AUDIT_SUBJ_USER:
  		case AUDIT_SUBJ_ROLE:
  		case AUDIT_SUBJ_TYPE:
  		case AUDIT_SUBJ_SEN:
  		case AUDIT_SUBJ_CLR:
  		case AUDIT_OBJ_USER:
  		case AUDIT_OBJ_ROLE:
  		case AUDIT_OBJ_TYPE:
  		case AUDIT_OBJ_LEV_LOW:
  		case AUDIT_OBJ_LEV_HIGH:
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
  			     struct audit_context *actx)
  {
  	struct context *ctxt;
  	struct mls_level *level;
  	struct selinux_audit_rule *rule = vrule;
  	int match = 0;
  
  	if (unlikely(!rule)) {
  		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
  		return -ENOENT;
  	}
  
  	read_lock(&policy_rwlock);
  
  	if (rule->au_seqno < latest_granting) {
  		match = -ESTALE;
  		goto out;
  	}
  
  	ctxt = sidtab_search(&sidtab, sid);
  	if (unlikely(!ctxt)) {
  		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
  			  sid);
  		match = -ENOENT;
  		goto out;
  	}
  
  	/* a field/op pair that is not caught here will simply fall through
  	   without a match */
  	switch (field) {
  	case AUDIT_SUBJ_USER:
  	case AUDIT_OBJ_USER:
  		switch (op) {
  		case Audit_equal:
  			match = (ctxt->user == rule->au_ctxt.user);
  			break;
  		case Audit_not_equal:
  			match = (ctxt->user != rule->au_ctxt.user);
  			break;
  		}
  		break;
  	case AUDIT_SUBJ_ROLE:
  	case AUDIT_OBJ_ROLE:
  		switch (op) {
  		case Audit_equal:
  			match = (ctxt->role == rule->au_ctxt.role);
  			break;
  		case Audit_not_equal:
  			match = (ctxt->role != rule->au_ctxt.role);
  			break;
  		}
  		break;
  	case AUDIT_SUBJ_TYPE:
  	case AUDIT_OBJ_TYPE:
  		switch (op) {
  		case Audit_equal:
  			match = (ctxt->type == rule->au_ctxt.type);
  			break;
  		case Audit_not_equal:
  			match = (ctxt->type != rule->au_ctxt.type);
  			break;
  		}
  		break;
  	case AUDIT_SUBJ_SEN:
  	case AUDIT_SUBJ_CLR:
  	case AUDIT_OBJ_LEV_LOW:
  	case AUDIT_OBJ_LEV_HIGH:
  		level = ((field == AUDIT_SUBJ_SEN ||
  			  field == AUDIT_OBJ_LEV_LOW) ?
  			 &ctxt->range.level[0] : &ctxt->range.level[1]);
  		switch (op) {
  		case Audit_equal:
  			match = mls_level_eq(&rule->au_ctxt.range.level[0],
  					     level);
  			break;
  		case Audit_not_equal:
  			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
  					      level);
  			break;
  		case Audit_lt:
  			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
  					       level) &&
  				 !mls_level_eq(&rule->au_ctxt.range.level[0],
  					       level));
  			break;
  		case Audit_le:
  			match = mls_level_dom(&rule->au_ctxt.range.level[0],
  					      level);
  			break;
  		case Audit_gt:
  			match = (mls_level_dom(level,
  					      &rule->au_ctxt.range.level[0]) &&
  				 !mls_level_eq(level,
  					       &rule->au_ctxt.range.level[0]));
  			break;
  		case Audit_ge:
  			match = mls_level_dom(level,
  					      &rule->au_ctxt.range.level[0]);
  			break;
  		}
  	}
  
  out:
  	read_unlock(&policy_rwlock);
  	return match;
  }
  
  static int (*aurule_callback)(void) = audit_update_lsm_rules;
  
  static int aurule_avc_callback(u32 event)
  {
  	int err = 0;
  
  	if (event == AVC_CALLBACK_RESET && aurule_callback)
  		err = aurule_callback();
  	return err;
  }
  
  static int __init aurule_init(void)
  {
  	int err;
  
  	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
  	if (err)
  		panic("avc_add_callback() failed, error %d\n", err);
  
  	return err;
  }
  __initcall(aurule_init);
  
  #ifdef CONFIG_NETLABEL
  /**
   * security_netlbl_cache_add - Add an entry to the NetLabel cache
   * @secattr: the NetLabel packet security attributes
   * @sid: the SELinux SID
   *
   * Description:
   * Attempt to cache the context in @ctx, which was derived from the packet in
   * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
   * already been initialized.
   *
   */
  static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
  				      u32 sid)
  {
  	u32 *sid_cache;
  
  	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
  	if (sid_cache == NULL)
  		return;
  	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
  	if (secattr->cache == NULL) {
  		kfree(sid_cache);
  		return;
  	}
  
  	*sid_cache = sid;
  	secattr->cache->free = kfree;
  	secattr->cache->data = sid_cache;
  	secattr->flags |= NETLBL_SECATTR_CACHE;
  }
  
  /**
   * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
   * @secattr: the NetLabel packet security attributes
   * @sid: the SELinux SID
   *
   * Description:
   * Convert the given NetLabel security attributes in @secattr into a
   * SELinux SID.  If the @secattr field does not contain a full SELinux
   * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
   * 'cache' field of @secattr is set and the CACHE flag is set; this is to
   * allow the @secattr to be used by NetLabel to cache the secattr to SID
   * conversion for future lookups.  Returns zero on success, negative values on
   * failure.
   *
   */
  int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
  				   u32 *sid)
  {
  	int rc;
  	struct context *ctx;
  	struct context ctx_new;
  
  	if (!ss_initialized) {
  		*sid = SECSID_NULL;
  		return 0;
  	}
  
  	read_lock(&policy_rwlock);
  
  	if (secattr->flags & NETLBL_SECATTR_CACHE)
  		*sid = *(u32 *)secattr->cache->data;
  	else if (secattr->flags & NETLBL_SECATTR_SECID)
  		*sid = secattr->attr.secid;
  	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
  		rc = -EIDRM;
  		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
  		if (ctx == NULL)
  			goto out;
  
  		context_init(&ctx_new);
  		ctx_new.user = ctx->user;
  		ctx_new.role = ctx->role;
  		ctx_new.type = ctx->type;
  		mls_import_netlbl_lvl(&ctx_new, secattr);
  		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
  			rc = mls_import_netlbl_cat(&ctx_new, secattr);
  			if (rc)
  				goto out;
  		}
  		rc = -EIDRM;
  		if (!mls_context_isvalid(&policydb, &ctx_new))
  			goto out_free;
  
  		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
  		if (rc)
  			goto out_free;
  
  		security_netlbl_cache_add(secattr, *sid);
  
  		ebitmap_destroy(&ctx_new.range.level[0].cat);
  	} else
  		*sid = SECSID_NULL;
  
  	read_unlock(&policy_rwlock);
  	return 0;
  out_free:
  	ebitmap_destroy(&ctx_new.range.level[0].cat);
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  
  /**
   * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
   * @sid: the SELinux SID
   * @secattr: the NetLabel packet security attributes
   *
   * Description:
   * Convert the given SELinux SID in @sid into a NetLabel security attribute.
   * Returns zero on success, negative values on failure.
   *
   */
  int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
  {
  	int rc;
  	struct context *ctx;
  
  	if (!ss_initialized)
  		return 0;
  
  	read_lock(&policy_rwlock);
  
  	rc = -ENOENT;
  	ctx = sidtab_search(&sidtab, sid);
  	if (ctx == NULL)
  		goto out;
  
  	rc = -ENOMEM;
  	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
  				  GFP_ATOMIC);
  	if (secattr->domain == NULL)
  		goto out;
  
  	secattr->attr.secid = sid;
  	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
  	mls_export_netlbl_lvl(ctx, secattr);
  	rc = mls_export_netlbl_cat(ctx, secattr);
  out:
  	read_unlock(&policy_rwlock);
  	return rc;
  }
  #endif /* CONFIG_NETLABEL */
  
  /**
   * security_read_policy - read the policy.
   * @data: binary policy data
   * @len: length of data in bytes
   *
   */
  int security_read_policy(void **data, size_t *len)
  {
  	int rc;
  	struct policy_file fp;
  
  	if (!ss_initialized)
  		return -EINVAL;
  
  	*len = security_policydb_len();
  
  	*data = vmalloc_user(*len);
  	if (!*data)
  		return -ENOMEM;
  
  	fp.data = *data;
  	fp.len = *len;
  
  	read_lock(&policy_rwlock);
  	rc = policydb_write(&policydb, &fp);
  	read_unlock(&policy_rwlock);
  
  	if (rc)
  		return rc;
  
  	*len = (unsigned long)fp.data - (unsigned long)*data;
  	return 0;
  
  }
  