services.c 60.5 KB
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/*
 * 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.
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 *	Support for context based audit filters.
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 *
 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 * 	Added conditional policy language extensions
 *
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 * Updated: Hewlett-Packard <paul.moore@hp.com>
 *
 *      Added support for NetLabel
 *
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 * Updated: Chad Sellers <csellers@tresys.com>
 *
 *  Added validation of kernel classes and permissions
 *
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 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
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 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
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 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
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 * 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>
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#include <linux/rcupdate.h>
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#include <linux/errno.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/audit.h>
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#include <linux/mutex.h>
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#include <net/netlabel.h>
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#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"
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#include "objsec.h"
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#include "netlabel.h"
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#include "xfrm.h"
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#include "ebitmap.h"
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extern void selnl_notify_policyload(u32 seqno);
unsigned int policydb_loaded_version;

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/*
 * This is declared in avc.c
 */
extern const struct selinux_class_perm selinux_class_perm;

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static DEFINE_RWLOCK(policy_rwlock);
#define POLICY_RDLOCK read_lock(&policy_rwlock)
#define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
#define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)

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static DEFINE_MUTEX(load_mutex);
#define LOAD_LOCK mutex_lock(&load_mutex)
#define LOAD_UNLOCK mutex_unlock(&load_mutex)
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static struct sidtab sidtab;
struct policydb policydb;
int ss_initialized = 0;

/*
 * 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 = 0;

/* Forward declaration. */
static int context_struct_to_string(struct context *context, char **scontext,
				    u32 *scontext_len);

/*
 * 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];
}

/*
 * Compute access vectors based on a context structure pair for
 * the permissions in a particular class.
 */
static int context_struct_compute_av(struct context *scontext,
				     struct context *tcontext,
				     u16 tclass,
				     u32 requested,
				     struct av_decision *avd)
{
	struct constraint_node *constraint;
	struct role_allow *ra;
	struct avtab_key avkey;
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	struct avtab_node *node;
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	struct class_datum *tclass_datum;
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	struct ebitmap *sattr, *tattr;
	struct ebitmap_node *snode, *tnode;
	unsigned int i, j;
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	/*
	 * Remap extended Netlink classes for old policy versions.
	 * Do this here rather than socket_type_to_security_class()
	 * in case a newer policy version is loaded, allowing sockets
	 * to remain in the correct class.
	 */
	if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
		if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
		    tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
			tclass = SECCLASS_NETLINK_SOCKET;

	if (!tclass || tclass > policydb.p_classes.nprim) {
		printk(KERN_ERR "security_compute_av:  unrecognized class %d\n",
		       tclass);
		return -EINVAL;
	}
	tclass_datum = policydb.class_val_to_struct[tclass - 1];

	/*
	 * Initialize the access vectors to the default values.
	 */
	avd->allowed = 0;
	avd->decided = 0xffffffff;
	avd->auditallow = 0;
	avd->auditdeny = 0xffffffff;
	avd->seqno = latest_granting;

	/*
	 * If a specific type enforcement rule was defined for
	 * this permission check, then use it.
	 */
	avkey.target_class = tclass;
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	avkey.specified = AVTAB_AV;
	sattr = &policydb.type_attr_map[scontext->type - 1];
	tattr = &policydb.type_attr_map[tcontext->type - 1];
	ebitmap_for_each_bit(sattr, snode, i) {
		if (!ebitmap_node_get_bit(snode, i))
			continue;
		ebitmap_for_each_bit(tattr, tnode, j) {
			if (!ebitmap_node_get_bit(tnode, j))
				continue;
			avkey.source_type = i + 1;
			avkey.target_type = j + 1;
			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
			     node != NULL;
			     node = avtab_search_node_next(node, avkey.specified)) {
				if (node->key.specified == AVTAB_ALLOWED)
					avd->allowed |= node->datum.data;
				else if (node->key.specified == AVTAB_AUDITALLOW)
					avd->auditallow |= node->datum.data;
				else if (node->key.specified == AVTAB_AUDITDENY)
					avd->auditdeny &= node->datum.data;
			}
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			/* Check conditional av table for additional permissions */
			cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);

		}
	}
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	/*
	 * 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 = (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 == SECCLASS_PROCESS &&
	    (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
	    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 = (avd->allowed) & ~(PROCESS__TRANSITION |
			                                PROCESS__DYNTRANSITION);
	}

	return 0;
}

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) < 0)
		goto out;
	if (context_struct_to_string(ncontext, &n, &nlen) < 0)
		goto out;
	if (context_struct_to_string(tcontext, &t, &tlen) < 0)
		goto out;
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	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
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	          "security_validate_transition:  denied for"
	          " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
	          o, n, t, policydb.p_class_val_to_name[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 tclass)
{
	struct context *ocontext;
	struct context *ncontext;
	struct context *tcontext;
	struct class_datum *tclass_datum;
	struct constraint_node *constraint;
	int rc = 0;

	if (!ss_initialized)
		return 0;

	POLICY_RDLOCK;

	/*
	 * Remap extended Netlink classes for old policy versions.
	 * Do this here rather than socket_type_to_security_class()
	 * in case a newer policy version is loaded, allowing sockets
	 * to remain in the correct class.
	 */
	if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
		if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
		    tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
			tclass = SECCLASS_NETLINK_SOCKET;

	if (!tclass || tclass > policydb.p_classes.nprim) {
		printk(KERN_ERR "security_validate_transition:  "
		       "unrecognized class %d\n", tclass);
		rc = -EINVAL;
		goto out;
	}
	tclass_datum = policydb.class_val_to_struct[tclass - 1];

	ocontext = sidtab_search(&sidtab, oldsid);
	if (!ocontext) {
		printk(KERN_ERR "security_validate_transition: "
		       " unrecognized SID %d\n", oldsid);
		rc = -EINVAL;
		goto out;
	}

	ncontext = sidtab_search(&sidtab, newsid);
	if (!ncontext) {
		printk(KERN_ERR "security_validate_transition: "
		       " unrecognized SID %d\n", newsid);
		rc = -EINVAL;
		goto out;
	}

	tcontext = sidtab_search(&sidtab, tasksid);
	if (!tcontext) {
		printk(KERN_ERR "security_validate_transition: "
		       " unrecognized SID %d\n", 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:
	POLICY_RDUNLOCK;
	return rc;
}

/**
 * security_compute_av - Compute access vector decisions.
 * @ssid: source security identifier
 * @tsid: target security identifier
 * @tclass: target security class
 * @requested: requested permissions
 * @avd: access vector decisions
 *
 * Compute a set of access vector decisions based on the
 * SID pair (@ssid, @tsid) for the permissions in @tclass.
 * Return -%EINVAL if any of the parameters are invalid or %0
 * if the access vector decisions were computed successfully.
 */
int security_compute_av(u32 ssid,
			u32 tsid,
			u16 tclass,
			u32 requested,
			struct av_decision *avd)
{
	struct context *scontext = NULL, *tcontext = NULL;
	int rc = 0;

	if (!ss_initialized) {
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		avd->allowed = 0xffffffff;
		avd->decided = 0xffffffff;
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		avd->auditallow = 0;
		avd->auditdeny = 0xffffffff;
		avd->seqno = latest_granting;
		return 0;
	}

	POLICY_RDLOCK;

	scontext = sidtab_search(&sidtab, ssid);
	if (!scontext) {
		printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
		       ssid);
		rc = -EINVAL;
		goto out;
	}
	tcontext = sidtab_search(&sidtab, tsid);
	if (!tcontext) {
		printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
		       tsid);
		rc = -EINVAL;
		goto out;
	}

	rc = context_struct_compute_av(scontext, tcontext, tclass,
				       requested, avd);
out:
	POLICY_RDUNLOCK;
	return rc;
}

/*
 * 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;

	*scontext = NULL;
	*scontext_len = 0;

	/* Compute the size of the context. */
	*scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
	*scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
	*scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
	*scontext_len += mls_compute_context_len(context);

	/* 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",
		policydb.p_user_val_to_name[context->user - 1],
		policydb.p_role_val_to_name[context->role - 1],
		policydb.p_type_val_to_name[context->type - 1]);
	scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
	             1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
	             1 + strlen(policydb.p_type_val_to_name[context->type - 1]);

	mls_sid_to_context(context, &scontextp);

	*scontextp = 0;

	return 0;
}

#include "initial_sid_to_string.h"

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const char *security_get_initial_sid_context(u32 sid)
{
	if (unlikely(sid > SECINITSID_NUM))
		return NULL;
	return initial_sid_to_string[sid];
}

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/**
 * 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)
{
	struct context *context;
	int rc = 0;

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	*scontext = NULL;
	*scontext_len  = 0;

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	if (!ss_initialized) {
		if (sid <= SECINITSID_NUM) {
			char *scontextp;

			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
			scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
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			if (!scontextp) {
				rc = -ENOMEM;
				goto out;
			}
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			strcpy(scontextp, initial_sid_to_string[sid]);
			*scontext = scontextp;
			goto out;
		}
		printk(KERN_ERR "security_sid_to_context:  called before initial "
		       "load_policy on unknown SID %d\n", sid);
		rc = -EINVAL;
		goto out;
	}
	POLICY_RDLOCK;
	context = sidtab_search(&sidtab, sid);
	if (!context) {
		printk(KERN_ERR "security_sid_to_context:  unrecognized SID "
		       "%d\n", sid);
		rc = -EINVAL;
		goto out_unlock;
	}
	rc = context_struct_to_string(context, scontext, scontext_len);
out_unlock:
	POLICY_RDUNLOCK;
out:
	return rc;

}

656
static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
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{
	char *scontext2;
	struct context context;
	struct role_datum *role;
	struct type_datum *typdatum;
	struct user_datum *usrdatum;
	char *scontextp, *p, oldc;
	int rc = 0;

	if (!ss_initialized) {
		int i;

		for (i = 1; i < SECINITSID_NUM; i++) {
			if (!strcmp(initial_sid_to_string[i], scontext)) {
				*sid = i;
				goto out;
			}
		}
		*sid = SECINITSID_KERNEL;
		goto out;
	}
	*sid = SECSID_NULL;

	/* Copy the string so that we can modify the copy as we parse it.
	   The string should already by null terminated, but we append a
	   null suffix to the copy to avoid problems with the existing
	   attr package, which doesn't view the null terminator as part
	   of the attribute value. */
	scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
	if (!scontext2) {
		rc = -ENOMEM;
		goto out;
	}
	memcpy(scontext2, scontext, scontext_len);
	scontext2[scontext_len] = 0;

	context_init(&context);
	*sid = SECSID_NULL;

	POLICY_RDLOCK;

	/* Parse the security context. */

	rc = -EINVAL;
	scontextp = (char *) scontext2;

	/* Extract the user. */
	p = scontextp;
	while (*p && *p != ':')
		p++;

	if (*p == 0)
		goto out_unlock;

	*p++ = 0;

	usrdatum = hashtab_search(policydb.p_users.table, scontextp);
	if (!usrdatum)
		goto out_unlock;

	context.user = usrdatum->value;

	/* Extract role. */
	scontextp = p;
	while (*p && *p != ':')
		p++;

	if (*p == 0)
		goto out_unlock;

	*p++ = 0;

	role = hashtab_search(policydb.p_roles.table, scontextp);
	if (!role)
		goto out_unlock;
	context.role = role->value;

	/* Extract type. */
	scontextp = p;
	while (*p && *p != ':')
		p++;
	oldc = *p;
	*p++ = 0;

	typdatum = hashtab_search(policydb.p_types.table, scontextp);
	if (!typdatum)
		goto out_unlock;

	context.type = typdatum->value;

747
	rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
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	if (rc)
		goto out_unlock;

	if ((p - scontext2) < scontext_len) {
		rc = -EINVAL;
		goto out_unlock;
	}

	/* Check the validity of the new context. */
	if (!policydb_context_isvalid(&policydb, &context)) {
		rc = -EINVAL;
		goto out_unlock;
	}
	/* Obtain the new sid. */
	rc = sidtab_context_to_sid(&sidtab, &context, sid);
out_unlock:
	POLICY_RDUNLOCK;
	context_destroy(&context);
	kfree(scontext2);
out:
	return rc;
}

771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
/**
 * security_context_to_sid - Obtain a SID for a given security context.
 * @scontext: security context
 * @scontext_len: length in bytes
 * @sid: security identifier, SID
 *
 * 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(char *scontext, u32 scontext_len, u32 *sid)
{
	return security_context_to_sid_core(scontext, scontext_len,
	                                    sid, SECSID_NULL);
}

/**
 * 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 errror
 *
 * 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).
 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 * memory is available, or 0 on success.
 */
int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
{
	return security_context_to_sid_core(scontext, scontext_len,
	                                    sid, def_sid);
}

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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) < 0)
		goto out;
	if (context_struct_to_string(tcontext, &t, &tlen) < 0)
		goto out;
	if (context_struct_to_string(newcontext, &n, &nlen) < 0)
		goto out;
826
	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
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		  "security_compute_sid:  invalid context %s"
		  " for scontext=%s"
		  " tcontext=%s"
		  " tclass=%s",
		  n, s, t, policydb.p_class_val_to_name[tclass-1]);
out:
	kfree(s);
	kfree(t);
	kfree(n);
	if (!selinux_enforcing)
		return 0;
	return -EACCES;
}

static int security_compute_sid(u32 ssid,
				u32 tsid,
				u16 tclass,
				u32 specified,
				u32 *out_sid)
{
	struct context *scontext = NULL, *tcontext = NULL, newcontext;
	struct role_trans *roletr = NULL;
	struct avtab_key avkey;
	struct avtab_datum *avdatum;
	struct avtab_node *node;
	int rc = 0;

	if (!ss_initialized) {
		switch (tclass) {
		case SECCLASS_PROCESS:
			*out_sid = ssid;
			break;
		default:
			*out_sid = tsid;
			break;
		}
		goto out;
	}

866 867
	context_init(&newcontext);

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	POLICY_RDLOCK;

	scontext = sidtab_search(&sidtab, ssid);
	if (!scontext) {
		printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
		       ssid);
		rc = -EINVAL;
		goto out_unlock;
	}
	tcontext = sidtab_search(&sidtab, tsid);
	if (!tcontext) {
		printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
		       tsid);
		rc = -EINVAL;
		goto out_unlock;
	}

	/* Set the user identity. */
	switch (specified) {
	case AVTAB_TRANSITION:
	case AVTAB_CHANGE:
		/* 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 and type to default values. */
	switch (tclass) {
	case SECCLASS_PROCESS:
		/* Use the current role and type of process. */
		newcontext.role = scontext->role;
		newcontext.type = scontext->type;
		break;
	default:
		/* Use the well-defined object role. */
		newcontext.role = OBJECT_R_VAL;
		/* 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;
916 917
	avkey.specified = specified;
	avdatum = avtab_search(&policydb.te_avtab, &avkey);
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	/* If no permanent rule, also check for enabled conditional rules */
	if(!avdatum) {
921
		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
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		for (; node != NULL; node = avtab_search_node_next(node, specified)) {
923
			if (node->key.specified & AVTAB_ENABLED) {
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				avdatum = &node->datum;
				break;
			}
		}
	}

930
	if (avdatum) {
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		/* Use the type from the type transition/member/change rule. */
932
		newcontext.type = avdatum->data;
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	}

	/* Check for class-specific changes. */
	switch (tclass) {
	case SECCLASS_PROCESS:
		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) {
					/* Use the role transition rule. */
					newcontext.role = roletr->new_role;
					break;
				}
			}
		}
		break;
	default:
		break;
	}

	/* Set the MLS attributes.
	   This is done last because it may allocate memory. */
	rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
	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:
	POLICY_RDUNLOCK;
	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,
			    u32 *out_sid)
{
	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
}

/**
 * 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, out_sid);
}

/**
 * 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, out_sid);
}

1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
/*
 * Verify that each kernel class that is defined in the
 * policy is correct
 */
static int validate_classes(struct policydb *p)
{
	int i, j;
	struct class_datum *cladatum;
	struct perm_datum *perdatum;
	u32 nprim, tmp, common_pts_len, perm_val, pol_val;
	u16 class_val;
	const struct selinux_class_perm *kdefs = &selinux_class_perm;
	const char *def_class, *def_perm, *pol_class;
	struct symtab *perms;

	for (i = 1; i < kdefs->cts_len; i++) {
		def_class = kdefs->class_to_string[i];
1059 1060
		if (!def_class)
			continue;
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
		if (i > p->p_classes.nprim) {
			printk(KERN_INFO
			       "security:  class %s not defined in policy\n",
			       def_class);
			continue;
		}
		pol_class = p->p_class_val_to_name[i-1];
		if (strcmp(pol_class, def_class)) {
			printk(KERN_ERR
			       "security:  class %d is incorrect, found %s but should be %s\n",
			       i, pol_class, def_class);
			return -EINVAL;
		}
	}
	for (i = 0; i < kdefs->av_pts_len; i++) {
		class_val = kdefs->av_perm_to_string[i].tclass;
		perm_val = kdefs->av_perm_to_string[i].value;
		def_perm = kdefs->av_perm_to_string[i].name;
		if (class_val > p->p_classes.nprim)
			continue;
		pol_class = p->p_class_val_to_name[class_val-1];
		cladatum = hashtab_search(p->p_classes.table, pol_class);
		BUG_ON(!cladatum);
		perms = &cladatum->permissions;
		nprim = 1 << (perms->nprim - 1);
		if (perm_val > nprim) {
			printk(KERN_INFO
			       "security:  permission %s in class %s not defined in policy\n",
			       def_perm, pol_class);
			continue;
		}
		perdatum = hashtab_search(perms->table, def_perm);
		if (perdatum == NULL) {
			printk(KERN_ERR
			       "security:  permission %s in class %s not found in policy\n",
			       def_perm, pol_class);
			return -EINVAL;
		}
		pol_val = 1 << (perdatum->value - 1);
		if (pol_val != perm_val) {
			printk(KERN_ERR
			       "security:  permission %s in class %s has incorrect value\n",
			       def_perm, pol_class);
			return -EINVAL;
		}
	}
	for (i = 0; i < kdefs->av_inherit_len; i++) {
		class_val = kdefs->av_inherit[i].tclass;
		if (class_val > p->p_classes.nprim)
			continue;
		pol_class = p->p_class_val_to_name[class_val-1];
		cladatum = hashtab_search(p->p_classes.table, pol_class);
		BUG_ON(!cladatum);
		if (!cladatum->comdatum) {
			printk(KERN_ERR
			       "security:  class %s should have an inherits clause but does not\n",
			       pol_class);
			return -EINVAL;
		}
		tmp = kdefs->av_inherit[i].common_base;
		common_pts_len = 0;
		while (!(tmp & 0x01)) {
			common_pts_len++;
			tmp >>= 1;
		}
		perms = &cladatum->comdatum->permissions;
		for (j = 0; j < common_pts_len; j++) {
			def_perm = kdefs->av_inherit[i].common_pts[j];
			if (j >= perms->nprim) {
				printk(KERN_INFO
				       "security:  permission %s in class %s not defined in policy\n",
				       def_perm, pol_class);
				continue;
			}
			perdatum = hashtab_search(perms->table, def_perm);
			if (perdatum == NULL) {
				printk(KERN_ERR
				       "security:  permission %s in class %s not found in policy\n",
				       def_perm, pol_class);
				return -EINVAL;
			}
			if (perdatum->value != j + 1) {
				printk(KERN_ERR
				       "security:  permission %s in class %s has incorrect value\n",
				       def_perm, pol_class);
				return -EINVAL;
			}
		}
	}
	return 0;
}

L
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1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
/* Clone the SID into the new SID table. */
static int clone_sid(u32 sid,
		     struct context *context,
		     void *arg)
{
	struct sidtab *s = arg;

	return sidtab_insert(s, sid, context);
}

static inline int convert_context_handle_invalid_context(struct context *context)
{
	int rc = 0;

	if (selinux_enforcing) {
		rc = -EINVAL;
	} else {
		char *s;
		u32 len;

		context_struct_to_string(context, &s, &len);
		printk(KERN_ERR "security:  context %s is invalid\n", s);
		kfree(s);
	}
	return rc;
}

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 role_datum *role;
	struct type_datum *typdatum;
	struct user_datum *usrdatum;
	char *s;
	u32 len;
	int rc;

	args = p;

	rc = context_cpy(&oldc, c);
	if (rc)
		goto out;

	rc = -EINVAL;

	/* Convert the user. */
	usrdatum = hashtab_search(args->newp->p_users.table,
	                          args->oldp->p_user_val_to_name[c->user - 1]);
	if (!usrdatum) {
		goto bad;
	}
	c->user = usrdatum->value;

	/* Convert the role. */
	role = hashtab_search(args->newp->p_roles.table,
	                      args->oldp->p_role_val_to_name[c->role - 1]);
	if (!role) {
		goto bad;
	}
	c->role = role->value;

	/* Convert the type. */
	typdatum = hashtab_search(args->newp->p_types.table,
	                          args->oldp->p_type_val_to_name[c->type - 1]);
	if (!typdatum) {
		goto bad;
	}
	c->type = typdatum->value;

	rc = mls_convert_context(args->oldp, args->newp, c);
	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);
out:
	return rc;
bad:
	context_struct_to_string(&oldc, &s, &len);
	context_destroy(&oldc);
	printk(KERN_ERR "security:  invalidating context %s\n", s);
	kfree(s);
	goto out;
}

extern void selinux_complete_init(void);
1260
static int security_preserve_bools(struct policydb *p);
L
Linus Torvalds 已提交
1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295

/**
 * 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 convert_context_args args;
	u32 seqno;
	int rc = 0;
	struct policy_file file = { data, len }, *fp = &file;

	LOAD_LOCK;

	if (!ss_initialized) {
		avtab_cache_init();
		if (policydb_read(&policydb, fp)) {
			LOAD_UNLOCK;
			avtab_cache_destroy();
			return -EINVAL;
		}
		if (policydb_load_isids(&policydb, &sidtab)) {
			LOAD_UNLOCK;
			policydb_destroy(&policydb);
			avtab_cache_destroy();
			return -EINVAL;
		}
1296 1297 1298 1299 1300 1301 1302 1303 1304 1305
		/* Verify that the kernel defined classes are correct. */
		if (validate_classes(&policydb)) {
			printk(KERN_ERR
			       "security:  the definition of a class is incorrect\n");
			LOAD_UNLOCK;
			sidtab_destroy(&sidtab);
			policydb_destroy(&policydb);
			avtab_cache_destroy();
			return -EINVAL;
		}
L
Linus Torvalds 已提交
1306 1307
		policydb_loaded_version = policydb.policyvers;
		ss_initialized = 1;
1308
		seqno = ++latest_granting;
L
Linus Torvalds 已提交
1309 1310
		LOAD_UNLOCK;
		selinux_complete_init();
1311 1312
		avc_ss_reset(seqno);
		selnl_notify_policyload(seqno);
V
Venkat Yekkirala 已提交
1313
		selinux_netlbl_cache_invalidate();
1314
		selinux_xfrm_notify_policyload();
L
Linus Torvalds 已提交
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
		return 0;
	}

#if 0
	sidtab_hash_eval(&sidtab, "sids");
#endif

	if (policydb_read(&newpolicydb, fp)) {
		LOAD_UNLOCK;
		return -EINVAL;
	}

	sidtab_init(&newsidtab);

1329 1330 1331 1332 1333 1334 1335 1336
	/* Verify that the kernel defined classes are correct. */
	if (validate_classes(&newpolicydb)) {
		printk(KERN_ERR
		       "security:  the definition of a class is incorrect\n");
		rc = -EINVAL;
		goto err;
	}

1337 1338 1339 1340 1341 1342
	rc = security_preserve_bools(&newpolicydb);
	if (rc) {
		printk(KERN_ERR "security:  unable to preserve booleans\n");
		goto err;
	}

L
Linus Torvalds 已提交
1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374
	/* Clone the SID table. */
	sidtab_shutdown(&sidtab);
	if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
		rc = -ENOMEM;
		goto err;
	}

	/* Convert the internal representations of contexts
	   in the new SID table and remove invalid SIDs. */
	args.oldp = &policydb;
	args.newp = &newpolicydb;
	sidtab_map_remove_on_error(&newsidtab, convert_context, &args);

	/* 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. */
	POLICY_WRLOCK;
	memcpy(&policydb, &newpolicydb, sizeof policydb);
	sidtab_set(&sidtab, &newsidtab);
	seqno = ++latest_granting;
	policydb_loaded_version = policydb.policyvers;
	POLICY_WRUNLOCK;
	LOAD_UNLOCK;

	/* Free the old policydb and SID table. */
	policydb_destroy(&oldpolicydb);
	sidtab_destroy(&oldsidtab);

	avc_ss_reset(seqno);
	selnl_notify_policyload(seqno);
V
Venkat Yekkirala 已提交
1375
	selinux_netlbl_cache_invalidate();
1376
	selinux_xfrm_notify_policyload();
L
Linus Torvalds 已提交
1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589

	return 0;

err:
	LOAD_UNLOCK;
	sidtab_destroy(&newsidtab);
	policydb_destroy(&newpolicydb);
	return rc;

}

/**
 * security_port_sid - Obtain the SID for a port.
 * @domain: communication domain aka address family
 * @type: socket type
 * @protocol: protocol number
 * @port: port number
 * @out_sid: security identifier
 */
int security_port_sid(u16 domain,
		      u16 type,
		      u8 protocol,
		      u16 port,
		      u32 *out_sid)
{
	struct ocontext *c;
	int rc = 0;

	POLICY_RDLOCK;

	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:
	POLICY_RDUNLOCK;
	return rc;
}

/**
 * security_netif_sid - Obtain the SID for a network interface.
 * @name: interface name
 * @if_sid: interface SID
 * @msg_sid: default SID for received packets
 */
int security_netif_sid(char *name,
		       u32 *if_sid,
		       u32 *msg_sid)
{
	int rc = 0;
	struct ocontext *c;

	POLICY_RDLOCK;

	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];
		*msg_sid = c->sid[1];
	} else {
		*if_sid = SECINITSID_NETIF;
		*msg_sid = SECINITSID_NETMSG;
	}

out:
	POLICY_RDUNLOCK;
	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 = 0;
	struct ocontext *c;

	POLICY_RDLOCK;

	switch (domain) {
	case AF_INET: {
		u32 addr;

		if (addrlen != sizeof(u32)) {
			rc = -EINVAL;
			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:
		if (addrlen != sizeof(u64) * 2) {
			rc = -EINVAL;
			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:
		*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;
	}

out:
	POLICY_RDUNLOCK;
	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;
1590
	u32 *mysids = NULL, *mysids2, sid;
L
Linus Torvalds 已提交
1591 1592 1593
	u32 mynel = 0, maxnel = SIDS_NEL;
	struct user_datum *user;
	struct role_datum *role;
1594
	struct ebitmap_node *rnode, *tnode;
L
Linus Torvalds 已提交
1595 1596
	int rc = 0, i, j;

1597 1598 1599 1600
	*sids = NULL;
	*nel = 0;

	if (!ss_initialized)
L
Linus Torvalds 已提交
1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617
		goto out;

	POLICY_RDLOCK;

	fromcon = sidtab_search(&sidtab, fromsid);
	if (!fromcon) {
		rc = -EINVAL;
		goto out_unlock;
	}

	user = hashtab_search(policydb.p_users.table, username);
	if (!user) {
		rc = -EINVAL;
		goto out_unlock;
	}
	usercon.user = user->value;

J
James Morris 已提交
1618
	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
L
Linus Torvalds 已提交
1619 1620 1621 1622 1623
	if (!mysids) {
		rc = -ENOMEM;
		goto out_unlock;
	}

1624 1625
	ebitmap_for_each_bit(&user->roles, rnode, i) {
		if (!ebitmap_node_get_bit(rnode, i))
L
Linus Torvalds 已提交
1626 1627 1628
			continue;
		role = policydb.role_val_to_struct[i];
		usercon.role = i+1;
1629 1630
		ebitmap_for_each_bit(&role->types, tnode, j) {
			if (!ebitmap_node_get_bit(tnode, j))
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636 1637
				continue;
			usercon.type = j+1;

			if (mls_setup_user_range(fromcon, user, &usercon))
				continue;

			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1638
			if (rc)
L
Linus Torvalds 已提交
1639 1640 1641 1642 1643
				goto out_unlock;
			if (mynel < maxnel) {
				mysids[mynel++] = sid;
			} else {
				maxnel += SIDS_NEL;
J
James Morris 已提交
1644
				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
L
Linus Torvalds 已提交
1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658
				if (!mysids2) {
					rc = -ENOMEM;
					goto out_unlock;
				}
				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
				kfree(mysids);
				mysids = mysids2;
				mysids[mynel++] = sid;
			}
		}
	}

out_unlock:
	POLICY_RDUNLOCK;
1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682
	if (rc || !mynel) {
		kfree(mysids);
		goto out;
	}

	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
	if (!mysids2) {
		rc = -ENOMEM;
		kfree(mysids);
		goto out;
	}
	for (i = 0, j = 0; i < mynel; i++) {
		rc = avc_has_perm_noaudit(fromsid, mysids[i],
					  SECCLASS_PROCESS,
					  PROCESS__TRANSITION, AVC_STRICT,
					  NULL);
		if (!rc)
			mysids2[j++] = mysids[i];
		cond_resched();
	}
	rc = 0;
	kfree(mysids);
	*sids = mysids2;
	*nel = j;
L
Linus Torvalds 已提交
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
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
 *
 * 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.
 */
int security_genfs_sid(const char *fstype,
	               char *path,
		       u16 sclass,
		       u32 *sid)
{
	int len;
	struct genfs *genfs;
	struct ocontext *c;
	int rc = 0, cmp = 0;

	POLICY_RDLOCK;

	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
		cmp = strcmp(fstype, genfs->fstype);
		if (cmp <= 0)
			break;
	}

	if (!genfs || cmp) {
		*sid = SECINITSID_UNLABELED;
		rc = -ENOENT;
		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;
	}

	if (!c) {
		*sid = SECINITSID_UNLABELED;
		rc = -ENOENT;
		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];
out:
	POLICY_RDUNLOCK;
	return rc;
}

/**
 * security_fs_use - Determine how to handle labeling for a filesystem.
 * @fstype: filesystem type
 * @behavior: labeling behavior
 * @sid: SID for filesystem (superblock)
 */
int security_fs_use(
	const char *fstype,
	unsigned int *behavior,
	u32 *sid)
{
	int rc = 0;
	struct ocontext *c;

	POLICY_RDLOCK;

	c = policydb.ocontexts[OCON_FSUSE];
	while (c) {
		if (strcmp(fstype, c->u.name) == 0)
			break;
		c = c->next;
	}

	if (c) {
		*behavior = c->v.behavior;
		if (!c->sid[0]) {
			rc = sidtab_context_to_sid(&sidtab,
						   &c->context[0],
						   &c->sid[0]);
			if (rc)
				goto out;
		}
		*sid = c->sid[0];
	} else {
		rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
		if (rc) {
			*behavior = SECURITY_FS_USE_NONE;
			rc = 0;
		} else {
			*behavior = SECURITY_FS_USE_GENFS;
		}
	}

out:
	POLICY_RDUNLOCK;
	return rc;
}

int security_get_bools(int *len, char ***names, int **values)
{
	int i, rc = -ENOMEM;

	POLICY_RDLOCK;
	*names = NULL;
	*values = NULL;

	*len = policydb.p_bools.nprim;
	if (!*len) {
		rc = 0;
		goto out;
	}

1811
       *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
L
Linus Torvalds 已提交
1812 1813 1814
	if (!*names)
		goto err;

1815
       *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
L
Linus Torvalds 已提交
1816 1817 1818 1819 1820 1821 1822
	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(policydb.p_bool_val_to_name[i]) + 1;
1823
               (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
L
Linus Torvalds 已提交
1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835
		if (!(*names)[i])
			goto err;
		strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
		(*names)[i][name_len - 1] = 0;
	}
	rc = 0;
out:
	POLICY_RDUNLOCK;
	return rc;
err:
	if (*names) {
		for (i = 0; i < *len; i++)
J
Jesper Juhl 已提交
1836
			kfree((*names)[i]);
L
Linus Torvalds 已提交
1837
	}
J
Jesper Juhl 已提交
1838
	kfree(*values);
L
Linus Torvalds 已提交
1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857
	goto out;
}


int security_set_bools(int len, int *values)
{
	int i, rc = 0;
	int lenp, seqno = 0;
	struct cond_node *cur;

	POLICY_WRLOCK;

	lenp = policydb.p_bools.nprim;
	if (len != lenp) {
		rc = -EFAULT;
		goto out;
	}

	for (i = 0; i < len; i++) {
S
Steve Grubb 已提交
1858 1859 1860 1861 1862 1863 1864 1865 1866
		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",
				policydb.p_bool_val_to_name[i],
				!!values[i],
				policydb.bool_val_to_struct[i]->state,
				audit_get_loginuid(current->audit_context));
		}
L
Linus Torvalds 已提交
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886
		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 != NULL; cur = cur->next) {
		rc = evaluate_cond_node(&policydb, cur);
		if (rc)
			goto out;
	}

	seqno = ++latest_granting;

out:
	POLICY_WRUNLOCK;
	if (!rc) {
		avc_ss_reset(seqno);
		selnl_notify_policyload(seqno);
1887
		selinux_xfrm_notify_policyload();
L
Linus Torvalds 已提交
1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909
	}
	return rc;
}

int security_get_bool_value(int bool)
{
	int rc = 0;
	int len;

	POLICY_RDLOCK;

	len = policydb.p_bools.nprim;
	if (bool >= len) {
		rc = -EFAULT;
		goto out;
	}

	rc = policydb.bool_val_to_struct[bool]->state;
out:
	POLICY_RDUNLOCK;
	return rc;
}
1910

1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941
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 != NULL; 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;
}

1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954
/*
 * 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 = 0;

1955
	if (!ss_initialized || !selinux_mls_enabled) {
1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
		*new_sid = sid;
		goto out;
	}

	context_init(&newcon);

	POLICY_RDLOCK;
	context1 = sidtab_search(&sidtab, sid);
	if (!context1) {
		printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
		       "%d\n", sid);
		rc = -EINVAL;
		goto out_unlock;
	}

	context2 = sidtab_search(&sidtab, mls_sid);
	if (!context2) {
		printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
		       "%d\n", mls_sid);
		rc = -EINVAL;
		goto out_unlock;
	}

	newcon.user = context1->user;
	newcon.role = context1->role;
	newcon.type = context1->type;
1982
	rc = mls_context_cpy(&newcon, context2);
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
	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)
			goto bad;
	}

	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
	goto out_unlock;

bad:
	if (!context_struct_to_string(&newcon, &s, &len)) {
		audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
			  "security_sid_mls_copy: invalid context %s", s);
		kfree(s);
	}

out_unlock:
	POLICY_RDUNLOCK;
	context_destroy(&newcon);
out:
	return rc;
}

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104
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 = -ENOMEM;

	POLICY_RDLOCK;

	*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 < 0) {
		int i;
		for (i = 0; i < *nclasses; i++)
			kfree((*classes)[i]);
		kfree(*classes);
	}

out:
	POLICY_RDUNLOCK;
	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 = -ENOMEM, i;
	struct class_datum *match;

	POLICY_RDLOCK;

	match = hashtab_search(policydb.p_classes.table, class);
	if (!match) {
		printk(KERN_ERR "%s:  unrecognized class %s\n",
			__FUNCTION__, class);
		rc = -EINVAL;
		goto out;
	}

	*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 < 0)
			goto err;
	}

	rc = hashtab_map(match->permissions.table, get_permissions_callback,
			*perms);
	if (rc < 0)
		goto err;

out:
	POLICY_RDUNLOCK;
	return rc;

err:
	POLICY_RDUNLOCK;
	for (i = 0; i < *nperms; i++)
		kfree((*perms)[i]);
	kfree(*perms);
	return rc;
}

2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
struct selinux_audit_rule {
	u32 au_seqno;
	struct context au_ctxt;
};

void selinux_audit_rule_free(struct selinux_audit_rule *rule)
{
	if (rule) {
		context_destroy(&rule->au_ctxt);
		kfree(rule);
	}
}

int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
                            struct selinux_audit_rule **rule)
{
	struct selinux_audit_rule *tmprule;
	struct role_datum *roledatum;
	struct type_datum *typedatum;
	struct user_datum *userdatum;
	int rc = 0;

	*rule = NULL;

	if (!ss_initialized)
		return -ENOTSUPP;

	switch (field) {
2133 2134 2135
	case AUDIT_SUBJ_USER:
	case AUDIT_SUBJ_ROLE:
	case AUDIT_SUBJ_TYPE:
2136 2137 2138
	case AUDIT_OBJ_USER:
	case AUDIT_OBJ_ROLE:
	case AUDIT_OBJ_TYPE:
2139 2140 2141 2142
		/* only 'equals' and 'not equals' fit user, role, and type */
		if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
			return -EINVAL;
		break;
2143 2144
	case AUDIT_SUBJ_SEN:
	case AUDIT_SUBJ_CLR:
2145 2146
	case AUDIT_OBJ_LEV_LOW:
	case AUDIT_OBJ_LEV_HIGH:
2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166
		/* we do not allow a range, indicated by the presense 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);

	POLICY_RDLOCK;

	tmprule->au_seqno = latest_granting;

	switch (field) {
2167
	case AUDIT_SUBJ_USER:
2168
	case AUDIT_OBJ_USER:
2169 2170 2171 2172 2173 2174
		userdatum = hashtab_search(policydb.p_users.table, rulestr);
		if (!userdatum)
			rc = -EINVAL;
		else
			tmprule->au_ctxt.user = userdatum->value;
		break;
2175
	case AUDIT_SUBJ_ROLE:
2176
	case AUDIT_OBJ_ROLE:
2177 2178 2179 2180 2181 2182
		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
		if (!roledatum)
			rc = -EINVAL;
		else
			tmprule->au_ctxt.role = roledatum->value;
		break;
2183
	case AUDIT_SUBJ_TYPE:
2184
	case AUDIT_OBJ_TYPE:
2185 2186 2187 2188 2189 2190
		typedatum = hashtab_search(policydb.p_types.table, rulestr);
		if (!typedatum)
			rc = -EINVAL;
		else
			tmprule->au_ctxt.type = typedatum->value;
		break;
2191 2192
	case AUDIT_SUBJ_SEN:
	case AUDIT_SUBJ_CLR:
2193 2194
	case AUDIT_OBJ_LEV_LOW:
	case AUDIT_OBJ_LEV_HIGH:
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
		break;
	}

	POLICY_RDUNLOCK;

	if (rc) {
		selinux_audit_rule_free(tmprule);
		tmprule = NULL;
	}

	*rule = tmprule;

	return rc;
}

2211
int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
                             struct selinux_audit_rule *rule,
                             struct audit_context *actx)
{
	struct context *ctxt;
	struct mls_level *level;
	int match = 0;

	if (!rule) {
		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
		          "selinux_audit_rule_match: missing rule\n");
		return -ENOENT;
	}

	POLICY_RDLOCK;

	if (rule->au_seqno < latest_granting) {
		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
		          "selinux_audit_rule_match: stale rule\n");
		match = -ESTALE;
		goto out;
	}

2234
	ctxt = sidtab_search(&sidtab, sid);
2235 2236 2237
	if (!ctxt) {
		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
		          "selinux_audit_rule_match: unrecognized SID %d\n",
2238
		          sid);
2239 2240 2241 2242 2243 2244 2245
		match = -ENOENT;
		goto out;
	}

	/* a field/op pair that is not caught here will simply fall through
	   without a match */
	switch (field) {
2246
	case AUDIT_SUBJ_USER:
2247
	case AUDIT_OBJ_USER:
2248 2249 2250 2251 2252 2253 2254 2255 2256
		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;
2257
	case AUDIT_SUBJ_ROLE:
2258
	case AUDIT_OBJ_ROLE:
2259 2260 2261 2262 2263 2264 2265 2266 2267
		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;
2268
	case AUDIT_SUBJ_TYPE:
2269
	case AUDIT_OBJ_TYPE:
2270 2271 2272 2273 2274 2275 2276 2277 2278
		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;
2279 2280
	case AUDIT_SUBJ_SEN:
	case AUDIT_SUBJ_CLR:
2281 2282 2283 2284
	case AUDIT_OBJ_LEV_LOW:
	case AUDIT_OBJ_LEV_HIGH:
		level = ((field == AUDIT_SUBJ_SEN ||
		          field == AUDIT_OBJ_LEV_LOW) ?
2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351
		         &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_LESS_THAN:
			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
			                       level) &&
			         !mls_level_eq(&rule->au_ctxt.range.level[0],
			                       level));
			break;
		case AUDIT_LESS_THAN_OR_EQUAL:
			match = mls_level_dom(&rule->au_ctxt.range.level[0],
			                      level);
			break;
		case AUDIT_GREATER_THAN:
			match = (mls_level_dom(level,
			                      &rule->au_ctxt.range.level[0]) &&
			         !mls_level_eq(level,
			                       &rule->au_ctxt.range.level[0]));
			break;
		case AUDIT_GREATER_THAN_OR_EQUAL:
			match = mls_level_dom(level,
			                      &rule->au_ctxt.range.level[0]);
			break;
		}
	}

out:
	POLICY_RDUNLOCK;
	return match;
}

static int (*aurule_callback)(void) = NULL;

static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
                               u16 class, u32 perms, u32 *retained)
{
	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,
	                       SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
	if (err)
		panic("avc_add_callback() failed, error %d\n", err);

	return err;
}
__initcall(aurule_init);

void selinux_audit_set_callback(int (*callback)(void))
{
	aurule_callback = callback;
}
V
Venkat Yekkirala 已提交
2352 2353 2354

#ifdef CONFIG_NETLABEL
/*
2355
 * NetLabel cache structure
V
Venkat Yekkirala 已提交
2356
 */
2357
#define NETLBL_CACHE(x)           ((struct selinux_netlbl_cache *)(x))
V
Venkat Yekkirala 已提交
2358 2359 2360
#define NETLBL_CACHE_T_NONE       0
#define NETLBL_CACHE_T_SID        1
#define NETLBL_CACHE_T_MLS        2
2361
struct selinux_netlbl_cache {
V
Venkat Yekkirala 已提交
2362 2363 2364 2365 2366 2367 2368 2369
	u32 type;
	union {
		u32 sid;
		struct mls_range mls_label;
	} data;
};

/**
2370
 * security_netlbl_cache_free - Free the NetLabel cached data
V
Venkat Yekkirala 已提交
2371 2372 2373 2374 2375 2376 2377
 * @data: the data to free
 *
 * Description:
 * This function is intended to be used as the free() callback inside the
 * netlbl_lsm_cache structure.
 *
 */
2378
static void security_netlbl_cache_free(const void *data)
V
Venkat Yekkirala 已提交
2379
{
2380
	struct selinux_netlbl_cache *cache;
2381 2382 2383 2384 2385

	if (data == NULL)
		return;

	cache = NETLBL_CACHE(data);
V
Venkat Yekkirala 已提交
2386 2387 2388 2389 2390 2391 2392 2393 2394
	switch (cache->type) {
	case NETLBL_CACHE_T_MLS:
		ebitmap_destroy(&cache->data.mls_label.level[0].cat);
		break;
	}
	kfree(data);
}

/**
2395 2396
 * security_netlbl_cache_add - Add an entry to the NetLabel cache
 * @secattr: the NetLabel packet security attributes
V
Venkat Yekkirala 已提交
2397 2398 2399 2400
 * @ctx: the SELinux context
 *
 * Description:
 * Attempt to cache the context in @ctx, which was derived from the packet in
2401 2402
 * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
 * already been initialized.
V
Venkat Yekkirala 已提交
2403 2404
 *
 */
2405 2406
static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
				      struct context *ctx)
V
Venkat Yekkirala 已提交
2407
{
2408
	struct selinux_netlbl_cache *cache = NULL;
V
Venkat Yekkirala 已提交
2409

2410 2411 2412
	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
	if (secattr->cache == NULL)
		return;
V
Venkat Yekkirala 已提交
2413 2414 2415

	cache = kzalloc(sizeof(*cache),	GFP_ATOMIC);
	if (cache == NULL)
2416
		return;
V
Venkat Yekkirala 已提交
2417 2418 2419

	cache->type = NETLBL_CACHE_T_MLS;
	if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2420 2421
			&ctx->range.level[0].cat) != 0) {
		kfree(cache);
2422
		return;
2423
	}
V
Venkat Yekkirala 已提交
2424 2425 2426 2427 2428 2429 2430
	cache->data.mls_label.level[1].cat.highbit =
		cache->data.mls_label.level[0].cat.highbit;
	cache->data.mls_label.level[1].cat.node =
		cache->data.mls_label.level[0].cat.node;
	cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
	cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;

2431 2432 2433
	secattr->cache->free = security_netlbl_cache_free;
	secattr->cache->data = (void *)cache;
	secattr->flags |= NETLBL_SECATTR_CACHE;
V
Venkat Yekkirala 已提交
2434 2435 2436
}

/**
2437
 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
V
Venkat Yekkirala 已提交
2438 2439 2440 2441 2442
 * @secattr: the NetLabel packet security attributes
 * @base_sid: the SELinux SID to use as a context for MLS only attributes
 * @sid: the SELinux SID
 *
 * Description:
2443
 * Convert the given NetLabel security attributes in @secattr into a
V
Venkat Yekkirala 已提交
2444
 * SELinux SID.  If the @secattr field does not contain a full SELinux
2445 2446 2447 2448 2449
 * SID/context then use the context in @base_sid as the foundation.  If
 * possibile 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.
V
Venkat Yekkirala 已提交
2450 2451
 *
 */
2452 2453 2454
int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
				   u32 base_sid,
				   u32 *sid)
V
Venkat Yekkirala 已提交
2455 2456 2457 2458
{
	int rc = -EIDRM;
	struct context *ctx;
	struct context ctx_new;
2459 2460 2461 2462 2463 2464
	struct selinux_netlbl_cache *cache;

	if (!ss_initialized) {
		*sid = SECSID_NULL;
		return 0;
	}
V
Venkat Yekkirala 已提交
2465 2466 2467

	POLICY_RDLOCK;

2468
	if (secattr->flags & NETLBL_SECATTR_CACHE) {
2469
		cache = NETLBL_CACHE(secattr->cache->data);
V
Venkat Yekkirala 已提交
2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500
		switch (cache->type) {
		case NETLBL_CACHE_T_SID:
			*sid = cache->data.sid;
			rc = 0;
			break;
		case NETLBL_CACHE_T_MLS:
			ctx = sidtab_search(&sidtab, base_sid);
			if (ctx == NULL)
				goto netlbl_secattr_to_sid_return;

			ctx_new.user = ctx->user;
			ctx_new.role = ctx->role;
			ctx_new.type = ctx->type;
			ctx_new.range.level[0].sens =
				cache->data.mls_label.level[0].sens;
			ctx_new.range.level[0].cat.highbit =
				cache->data.mls_label.level[0].cat.highbit;
			ctx_new.range.level[0].cat.node =
				cache->data.mls_label.level[0].cat.node;
			ctx_new.range.level[1].sens =
				cache->data.mls_label.level[1].sens;
			ctx_new.range.level[1].cat.highbit =
				cache->data.mls_label.level[1].cat.highbit;
			ctx_new.range.level[1].cat.node =
				cache->data.mls_label.level[1].cat.node;

			rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
			break;
		default:
			goto netlbl_secattr_to_sid_return;
		}
2501
	} else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
V
Venkat Yekkirala 已提交
2502 2503 2504 2505 2506 2507 2508
		ctx = sidtab_search(&sidtab, base_sid);
		if (ctx == NULL)
			goto netlbl_secattr_to_sid_return;

		ctx_new.user = ctx->user;
		ctx_new.role = ctx->role;
		ctx_new.type = ctx->type;
2509
		mls_import_netlbl_lvl(&ctx_new, secattr);
2510
		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2511 2512
			if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
						  secattr->mls_cat) != 0)
V
Venkat Yekkirala 已提交
2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528
				goto netlbl_secattr_to_sid_return;
			ctx_new.range.level[1].cat.highbit =
				ctx_new.range.level[0].cat.highbit;
			ctx_new.range.level[1].cat.node =
				ctx_new.range.level[0].cat.node;
		} else {
			ebitmap_init(&ctx_new.range.level[0].cat);
			ebitmap_init(&ctx_new.range.level[1].cat);
		}
		if (mls_context_isvalid(&policydb, &ctx_new) != 1)
			goto netlbl_secattr_to_sid_return_cleanup;

		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
		if (rc != 0)
			goto netlbl_secattr_to_sid_return_cleanup;

2529 2530
		security_netlbl_cache_add(secattr, &ctx_new);

V
Venkat Yekkirala 已提交
2531 2532
		ebitmap_destroy(&ctx_new.range.level[0].cat);
	} else {
2533
		*sid = SECSID_NULL;
V
Venkat Yekkirala 已提交
2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545
		rc = 0;
	}

netlbl_secattr_to_sid_return:
	POLICY_RDUNLOCK;
	return rc;
netlbl_secattr_to_sid_return_cleanup:
	ebitmap_destroy(&ctx_new.range.level[0].cat);
	goto netlbl_secattr_to_sid_return;
}

/**
2546 2547 2548
 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
 * @sid: the SELinux SID
 * @secattr: the NetLabel packet security attributes
V
Venkat Yekkirala 已提交
2549 2550
 *
 * Description:
2551 2552
 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
 * Returns zero on success, negative values on failure.
V
Venkat Yekkirala 已提交
2553 2554
 *
 */
2555
int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
V
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{
	int rc = -ENOENT;
	struct context *ctx;

2560 2561
	netlbl_secattr_init(secattr);

V
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	if (!ss_initialized)
		return 0;

	POLICY_RDLOCK;
	ctx = sidtab_search(&sidtab, sid);
	if (ctx == NULL)
2568 2569 2570 2571 2572 2573
		goto netlbl_sid_to_secattr_failure;
	secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
				  GFP_ATOMIC);
	secattr->flags |= NETLBL_SECATTR_DOMAIN;
	mls_export_netlbl_lvl(ctx, secattr);
	rc = mls_export_netlbl_cat(ctx, secattr);
2574
	if (rc != 0)
2575
		goto netlbl_sid_to_secattr_failure;
V
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2576
	POLICY_RDUNLOCK;
2577

2578
	return 0;
2579

2580 2581 2582
netlbl_sid_to_secattr_failure:
	POLICY_RDUNLOCK;
	netlbl_secattr_destroy(secattr);
2583 2584
	return rc;
}
V
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2585
#endif /* CONFIG_NETLABEL */