[linux-2.6-block.git] / security / smack / smack_access.c

/*
 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.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.
 *
 * Author:
 *      Casey Schaufler <casey@schaufler-ca.com>
 *
 */

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include "smack.h"

struct smack_known smack_known_huh = {
	.smk_known	= "?",
	.smk_secid	= 2,
	.smk_cipso	= NULL,
};

struct smack_known smack_known_hat = {
	.smk_known	= "^",
	.smk_secid	= 3,
	.smk_cipso	= NULL,
};

struct smack_known smack_known_star = {
	.smk_known	= "*",
	.smk_secid	= 4,
	.smk_cipso	= NULL,
};

struct smack_known smack_known_floor = {
	.smk_known	= "_",
	.smk_secid	= 5,
	.smk_cipso	= NULL,
};

struct smack_known smack_known_invalid = {
	.smk_known	= "",
	.smk_secid	= 6,
	.smk_cipso	= NULL,
};

struct smack_known smack_known_web = {
	.smk_known	= "@",
	.smk_secid	= 7,
	.smk_cipso	= NULL,
};

LIST_HEAD(smack_known_list);

/*
 * The initial value needs to be bigger than any of the
 * known values above.
 */
static u32 smack_next_secid = 10;

/*
 * what events do we log
 * can be overwritten at run-time by /smack/logging
 */
int log_policy = SMACK_AUDIT_DENIED;

/**
 * smk_access - determine if a subject has a specific access to an object
 * @subject_label: a pointer to the subject's Smack label
 * @object_label: a pointer to the object's Smack label
 * @request: the access requested, in "MAY" format
 * @a : a pointer to the audit data
 *
 * This function looks up the subject/object pair in the
 * access rule list and returns 0 if the access is permitted,
 * non zero otherwise.
 *
 * Even though Smack labels are usually shared on smack_list
 * labels that come in off the network can't be imported
 * and added to the list for locking reasons.
 *
 * Therefore, it is necessary to check the contents of the labels,
 * not just the pointer values. Of course, in most cases the labels
 * will be on the list, so checking the pointers may be a worthwhile
 * optimization.
 */
int smk_access(char *subject_label, char *object_label, int request,
	       struct smk_audit_info *a)
{
	u32 may = MAY_NOT;
	struct smack_rule *srp;
	int rc = 0;

	/*
	 * Hardcoded comparisons.
	 *
	 * A star subject can't access any object.
	 */
	if (subject_label == smack_known_star.smk_known ||
	    strcmp(subject_label, smack_known_star.smk_known) == 0) {
		rc = -EACCES;
		goto out_audit;
	}
	/*
	 * An internet object can be accessed by any subject.
	 * Tasks cannot be assigned the internet label.
	 * An internet subject can access any object.
	 */
	if (object_label == smack_known_web.smk_known ||
	    subject_label == smack_known_web.smk_known ||
	    strcmp(object_label, smack_known_web.smk_known) == 0 ||
	    strcmp(subject_label, smack_known_web.smk_known) == 0)
		goto out_audit;
	/*
	 * A star object can be accessed by any subject.
	 */
	if (object_label == smack_known_star.smk_known ||
	    strcmp(object_label, smack_known_star.smk_known) == 0)
		goto out_audit;
	/*
	 * An object can be accessed in any way by a subject
	 * with the same label.
	 */
	if (subject_label == object_label ||
	    strcmp(subject_label, object_label) == 0)
		goto out_audit;
	/*
	 * A hat subject can read any object.
	 * A floor object can be read by any subject.
	 */
	if ((request & MAY_ANYREAD) == request) {
		if (object_label == smack_known_floor.smk_known ||
		    strcmp(object_label, smack_known_floor.smk_known) == 0)
			goto out_audit;
		if (subject_label == smack_known_hat.smk_known ||
		    strcmp(subject_label, smack_known_hat.smk_known) == 0)
			goto out_audit;
	}
	/*
	 * Beyond here an explicit relationship is required.
	 * If the requested access is contained in the available
	 * access (e.g. read is included in readwrite) it's
	 * good.
	 */
	rcu_read_lock();
	list_for_each_entry_rcu(srp, &smack_rule_list, list) {
		if (srp->smk_subject == subject_label ||
		    strcmp(srp->smk_subject, subject_label) == 0) {
			if (srp->smk_object == object_label ||
			    strcmp(srp->smk_object, object_label) == 0) {
				may = srp->smk_access;
				break;
			}
		}
	}
	rcu_read_unlock();
	/*
	 * This is a bit map operation.
	 */
	if ((request & may) == request)
		goto out_audit;

	rc = -EACCES;
out_audit:
#ifdef CONFIG_AUDIT
	if (a)
		smack_log(subject_label, object_label, request, rc, a);
#endif
	return rc;
}

/**
 * smk_curacc - determine if current has a specific access to an object
 * @obj_label: a pointer to the object's Smack label
 * @mode: the access requested, in "MAY" format
 * @a : common audit data
 *
 * This function checks the current subject label/object label pair
 * in the access rule list and returns 0 if the access is permitted,
 * non zero otherwise. It allows that current may have the capability
 * to override the rules.
 */
int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
{
	int rc;
	char *sp = current_security();

	rc = smk_access(sp, obj_label, mode, NULL);
	if (rc == 0)
		goto out_audit;

	/*
	 * Return if a specific label has been designated as the
	 * only one that gets privilege and current does not
	 * have that label.
	 */
	if (smack_onlycap != NULL && smack_onlycap != current->cred->security)
		goto out_audit;

	if (capable(CAP_MAC_OVERRIDE))
		return 0;

out_audit:
#ifdef CONFIG_AUDIT
	if (a)
		smack_log(sp, obj_label, mode, rc, a);
#endif
	return rc;
}

#ifdef CONFIG_AUDIT
/**
 * smack_str_from_perm : helper to transalate an int to a
 * readable string
 * @string : the string to fill
 * @access : the int
 *
 */
static inline void smack_str_from_perm(char *string, int access)
{
	int i = 0;
	if (access & MAY_READ)
		string[i++] = 'r';
	if (access & MAY_WRITE)
		string[i++] = 'w';
	if (access & MAY_EXEC)
		string[i++] = 'x';
	if (access & MAY_APPEND)
		string[i++] = 'a';
	string[i] = '\0';
}
/**
 * smack_log_callback - SMACK specific information
 * will be called by generic audit code
 * @ab : the audit_buffer
 * @a  : audit_data
 *
 */
static void smack_log_callback(struct audit_buffer *ab, void *a)
{
	struct common_audit_data *ad = a;
	struct smack_audit_data *sad = &ad->smack_audit_data;
	audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
			 ad->smack_audit_data.function,
			 sad->result ? "denied" : "granted");
	audit_log_format(ab, " subject=");
	audit_log_untrustedstring(ab, sad->subject);
	audit_log_format(ab, " object=");
	audit_log_untrustedstring(ab, sad->object);
	audit_log_format(ab, " requested=%s", sad->request);
}

/**
 *  smack_log - Audit the granting or denial of permissions.
 *  @subject_label : smack label of the requester
 *  @object_label  : smack label of the object being accessed
 *  @request: requested permissions
 *  @result: result from smk_access
 *  @a:  auxiliary audit data
 *
 * Audit the granting or denial of permissions in accordance
 * with the policy.
 */
void smack_log(char *subject_label, char *object_label, int request,
	       int result, struct smk_audit_info *ad)
{
	char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
	struct smack_audit_data *sad;
	struct common_audit_data *a = &ad->a;

	/* check if we have to log the current event */
	if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
		return;
	if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
		return;

	if (a->smack_audit_data.function == NULL)
		a->smack_audit_data.function = "unknown";

	/* end preparing the audit data */
	sad = &a->smack_audit_data;
	smack_str_from_perm(request_buffer, request);
	sad->subject = subject_label;
	sad->object  = object_label;
	sad->request = request_buffer;
	sad->result  = result;
	a->lsm_pre_audit = smack_log_callback;

	common_lsm_audit(a);
}
#else /* #ifdef CONFIG_AUDIT */
void smack_log(char *subject_label, char *object_label, int request,
               int result, struct smk_audit_info *ad)
{
}
#endif

static DEFINE_MUTEX(smack_known_lock);

/**
 * smk_import_entry - import a label, return the list entry
 * @string: a text string that might be a Smack label
 * @len: the maximum size, or zero if it is NULL terminated.
 *
 * Returns a pointer to the entry in the label list that
 * matches the passed string, adding it if necessary.
 */
struct smack_known *smk_import_entry(const char *string, int len)
{
	struct smack_known *skp;
	char smack[SMK_LABELLEN];
	int found;
	int i;

	if (len <= 0 || len > SMK_MAXLEN)
		len = SMK_MAXLEN;

	for (i = 0, found = 0; i < SMK_LABELLEN; i++) {
		if (found)
			smack[i] = '\0';
		else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
			 string[i] == '/' || string[i] == '"' ||
			 string[i] == '\\' || string[i] == '\'') {
			smack[i] = '\0';
			found = 1;
		} else
			smack[i] = string[i];
	}

	if (smack[0] == '\0')
		return NULL;

	mutex_lock(&smack_known_lock);

	found = 0;
	list_for_each_entry_rcu(skp, &smack_known_list, list) {
		if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
			found = 1;
			break;
		}
	}

	if (found == 0) {
		skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
		if (skp != NULL) {
			strncpy(skp->smk_known, smack, SMK_MAXLEN);
			skp->smk_secid = smack_next_secid++;
			skp->smk_cipso = NULL;
			spin_lock_init(&skp->smk_cipsolock);
			/*
			 * Make sure that the entry is actually
			 * filled before putting it on the list.
			 */
			list_add_rcu(&skp->list, &smack_known_list);
		}
	}

	mutex_unlock(&smack_known_lock);

	return skp;
}

/**
 * smk_import - import a smack label
 * @string: a text string that might be a Smack label
 * @len: the maximum size, or zero if it is NULL terminated.
 *
 * Returns a pointer to the label in the label list that
 * matches the passed string, adding it if necessary.
 */
char *smk_import(const char *string, int len)
{
	struct smack_known *skp;

	/* labels cannot begin with a '-' */
	if (string[0] == '-')
		return NULL;
	skp = smk_import_entry(string, len);
	if (skp == NULL)
		return NULL;
	return skp->smk_known;
}

/**
 * smack_from_secid - find the Smack label associated with a secid
 * @secid: an integer that might be associated with a Smack label
 *
 * Returns a pointer to the appropraite Smack label if there is one,
 * otherwise a pointer to the invalid Smack label.
 */
char *smack_from_secid(const u32 secid)
{
	struct smack_known *skp;

	rcu_read_lock();
	list_for_each_entry_rcu(skp, &smack_known_list, list) {
		if (skp->smk_secid == secid) {
			rcu_read_unlock();
			return skp->smk_known;
		}
	}

	/*
	 * If we got this far someone asked for the translation
	 * of a secid that is not on the list.
	 */
	rcu_read_unlock();
	return smack_known_invalid.smk_known;
}

/**
 * smack_to_secid - find the secid associated with a Smack label
 * @smack: the Smack label
 *
 * Returns the appropriate secid if there is one,
 * otherwise 0
 */
u32 smack_to_secid(const char *smack)
{
	struct smack_known *skp;

	rcu_read_lock();
	list_for_each_entry_rcu(skp, &smack_known_list, list) {
		if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
			rcu_read_unlock();
			return skp->smk_secid;
		}
	}
	rcu_read_unlock();
	return 0;
}

/**
 * smack_from_cipso - find the Smack label associated with a CIPSO option
 * @level: Bell & LaPadula level from the network
 * @cp: Bell & LaPadula categories from the network
 * @result: where to put the Smack value
 *
 * This is a simple lookup in the label table.
 *
 * This is an odd duck as far as smack handling goes in that
 * it sends back a copy of the smack label rather than a pointer
 * to the master list. This is done because it is possible for
 * a foreign host to send a smack label that is new to this
 * machine and hence not on the list. That would not be an
 * issue except that adding an entry to the master list can't
 * be done at that point.
 */
void smack_from_cipso(u32 level, char *cp, char *result)
{
	struct smack_known *kp;
	char *final = NULL;

	rcu_read_lock();
	list_for_each_entry(kp, &smack_known_list, list) {
		if (kp->smk_cipso == NULL)
			continue;

		spin_lock_bh(&kp->smk_cipsolock);

		if (kp->smk_cipso->smk_level == level &&
		    memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0)
			final = kp->smk_known;

		spin_unlock_bh(&kp->smk_cipsolock);
	}
	rcu_read_unlock();
	if (final == NULL)
		final = smack_known_huh.smk_known;
	strncpy(result, final, SMK_MAXLEN);
	return;
}

/**
 * smack_to_cipso - find the CIPSO option to go with a Smack label
 * @smack: a pointer to the smack label in question
 * @cp: where to put the result
 *
 * Returns zero if a value is available, non-zero otherwise.
 */
int smack_to_cipso(const char *smack, struct smack_cipso *cp)
{
	struct smack_known *kp;
	int found = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(kp, &smack_known_list, list) {
		if (kp->smk_known == smack ||
		    strcmp(kp->smk_known, smack) == 0) {
			found = 1;
			break;
		}
	}
	rcu_read_unlock();

	if (found == 0 || kp->smk_cipso == NULL)
		return -ENOENT;

	memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
	return 0;
}
Commit	Line	Data
e114e473 CS	1	/*
	2	* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation, version 2.
	7	*
	8	* Author:
	9	* Casey Schaufler <casey@schaufler-ca.com>
	10	*
	11	*/
	12
	13	#include <linux/types.h>
	14	#include <linux/fs.h>
	15	#include <linux/sched.h>
	16	#include "smack.h"
	17
e114e473	18	struct smack_known smack_known_huh = {
e114e473 CS	19	.smk_known = "?",
	20	.smk_secid = 2,
	21	.smk_cipso = NULL,
	22	};
	23
	24	struct smack_known smack_known_hat = {
e114e473 CS	25	.smk_known = "^",
	26	.smk_secid = 3,
	27	.smk_cipso = NULL,
	28	};
	29
	30	struct smack_known smack_known_star = {
e114e473 CS	31	.smk_known = "*",
	32	.smk_secid = 4,
	33	.smk_cipso = NULL,
	34	};
	35
	36	struct smack_known smack_known_floor = {
e114e473 CS	37	.smk_known = "_",
	38	.smk_secid = 5,
	39	.smk_cipso = NULL,
	40	};
	41
	42	struct smack_known smack_known_invalid = {
e114e473 CS	43	.smk_known = "",
	44	.smk_secid = 6,
	45	.smk_cipso = NULL,
	46	};
	47
6d3dc07c	48	struct smack_known smack_known_web = {
6d3dc07c CS	49	.smk_known = "@",
	50	.smk_secid = 7,
	51	.smk_cipso = NULL,
	52	};
	53
7198e2ee	54	LIST_HEAD(smack_known_list);
e114e473 CS	55
	56	/*
	57	* The initial value needs to be bigger than any of the
	58	* known values above.
	59	*/
	60	static u32 smack_next_secid = 10;
	61
ecfcc53f EB	62	/*
	63	* what events do we log
	64	* can be overwritten at run-time by /smack/logging
	65	*/
	66	int log_policy = SMACK_AUDIT_DENIED;
	67
e114e473 CS	68	/**
	69	* smk_access - determine if a subject has a specific access to an object
	70	* @subject_label: a pointer to the subject's Smack label
	71	* @object_label: a pointer to the object's Smack label
	72	* @request: the access requested, in "MAY" format
ecfcc53f	73	* @a : a pointer to the audit data
e114e473 CS	74	*
	75	* This function looks up the subject/object pair in the
	76	* access rule list and returns 0 if the access is permitted,
	77	* non zero otherwise.
	78	*
	79	* Even though Smack labels are usually shared on smack_list
	80	* labels that come in off the network can't be imported
	81	* and added to the list for locking reasons.
	82	*
	83	* Therefore, it is necessary to check the contents of the labels,
	84	* not just the pointer values. Of course, in most cases the labels
	85	* will be on the list, so checking the pointers may be a worthwhile
	86	* optimization.
	87	*/
ecfcc53f EB	88	int smk_access(char subject_label, char object_label, int request,
ecfcc53f EB	89	struct smk_audit_info *a)
e114e473 CS	90	{
e114e473 CS	91	u32 may = MAY_NOT;
e114e473	92	struct smack_rule *srp;
ecfcc53f	93	int rc = 0;
e114e473 CS	94
	95	/*
	96	* Hardcoded comparisons.
	97	*
	98	* A star subject can't access any object.
	99	*/
	100	if (subject_label == smack_known_star.smk_known \|\|
ecfcc53f EB	101	strcmp(subject_label, smack_known_star.smk_known) == 0) {
	102	rc = -EACCES;
	103	goto out_audit;
	104	}
6d3dc07c CS	105	/*
	106	* An internet object can be accessed by any subject.
	107	* Tasks cannot be assigned the internet label.
	108	* An internet subject can access any object.
	109	*/
	110	if (object_label == smack_known_web.smk_known \|\|
	111	subject_label == smack_known_web.smk_known \|\|
	112	strcmp(object_label, smack_known_web.smk_known) == 0 \|\|
	113	strcmp(subject_label, smack_known_web.smk_known) == 0)
ecfcc53f	114	goto out_audit;
e114e473 CS	115	/*
	116	* A star object can be accessed by any subject.
	117	*/
	118	if (object_label == smack_known_star.smk_known \|\|
	119	strcmp(object_label, smack_known_star.smk_known) == 0)
ecfcc53f	120	goto out_audit;
e114e473 CS	121	/*
	122	* An object can be accessed in any way by a subject
	123	* with the same label.
	124	*/
	125	if (subject_label == object_label \|\|
	126	strcmp(subject_label, object_label) == 0)
ecfcc53f	127	goto out_audit;
e114e473 CS	128	/*
	129	* A hat subject can read any object.
	130	* A floor object can be read by any subject.
	131	*/
	132	if ((request & MAY_ANYREAD) == request) {
	133	if (object_label == smack_known_floor.smk_known \|\|
	134	strcmp(object_label, smack_known_floor.smk_known) == 0)
ecfcc53f	135	goto out_audit;
e114e473 CS	136	if (subject_label == smack_known_hat.smk_known \|\|
e114e473 CS	137	strcmp(subject_label, smack_known_hat.smk_known) == 0)
ecfcc53f	138	goto out_audit;
e114e473 CS	139	}
	140	/*
	141	* Beyond here an explicit relationship is required.
	142	* If the requested access is contained in the available
	143	* access (e.g. read is included in readwrite) it's
	144	* good.
	145	*/
7198e2ee EB	146	rcu_read_lock();
7198e2ee EB	147	list_for_each_entry_rcu(srp, &smack_rule_list, list) {
e114e473 CS	148	if (srp->smk_subject == subject_label \|\|
	149	strcmp(srp->smk_subject, subject_label) == 0) {
	150	if (srp->smk_object == object_label \|\|
	151	strcmp(srp->smk_object, object_label) == 0) {
	152	may = srp->smk_access;
	153	break;
	154	}
	155	}
	156	}
7198e2ee	157	rcu_read_unlock();
e114e473 CS	158	/*
	159	* This is a bit map operation.
	160	*/
	161	if ((request & may) == request)
ecfcc53f	162	goto out_audit;
e114e473	163
ecfcc53f EB	164	rc = -EACCES;
	165	out_audit:
	166	#ifdef CONFIG_AUDIT
	167	if (a)
	168	smack_log(subject_label, object_label, request, rc, a);
	169	#endif
	170	return rc;
e114e473 CS	171	}
	172
	173	/**
	174	* smk_curacc - determine if current has a specific access to an object
251a2a95 RD	175	* @obj_label: a pointer to the object's Smack label
251a2a95 RD	176	* @mode: the access requested, in "MAY" format
ecfcc53f	177	* @a : common audit data
e114e473 CS	178	*
	179	* This function checks the current subject label/object label pair
	180	* in the access rule list and returns 0 if the access is permitted,
15446235	181	* non zero otherwise. It allows that current may have the capability
e114e473 CS	182	* to override the rules.
e114e473 CS	183	*/
ecfcc53f	184	int smk_curacc(char obj_label, u32 mode, struct smk_audit_info a)
e114e473 CS	185	{
e114e473 CS	186	int rc;
ecfcc53f	187	char *sp = current_security();
e114e473	188
ecfcc53f	189	rc = smk_access(sp, obj_label, mode, NULL);
e114e473	190	if (rc == 0)
ecfcc53f	191	goto out_audit;
e114e473	192
15446235 CS	193	/*
	194	* Return if a specific label has been designated as the
	195	* only one that gets privilege and current does not
	196	* have that label.
	197	*/
b6dff3ec	198	if (smack_onlycap != NULL && smack_onlycap != current->cred->security)
ecfcc53f	199	goto out_audit;
15446235	200
e114e473 CS	201	if (capable(CAP_MAC_OVERRIDE))
	202	return 0;
	203
ecfcc53f EB	204	out_audit:
	205	#ifdef CONFIG_AUDIT
	206	if (a)
	207	smack_log(sp, obj_label, mode, rc, a);
	208	#endif
e114e473 CS	209	return rc;
	210	}
	211
ecfcc53f EB	212	#ifdef CONFIG_AUDIT
	213	/**
	214	* smack_str_from_perm : helper to transalate an int to a
	215	* readable string
	216	* @string : the string to fill
	217	* @access : the int
	218	*
	219	*/
	220	static inline void smack_str_from_perm(char *string, int access)
	221	{
	222	int i = 0;
	223	if (access & MAY_READ)
	224	string[i++] = 'r';
	225	if (access & MAY_WRITE)
	226	string[i++] = 'w';
	227	if (access & MAY_EXEC)
	228	string[i++] = 'x';
	229	if (access & MAY_APPEND)
	230	string[i++] = 'a';
	231	string[i] = '\0';
	232	}
	233	/**
	234	* smack_log_callback - SMACK specific information
	235	* will be called by generic audit code
	236	* @ab : the audit_buffer
	237	* @a : audit_data
	238	*
	239	*/
	240	static void smack_log_callback(struct audit_buffer ab, void a)
	241	{
	242	struct common_audit_data *ad = a;
d4131ded	243	struct smack_audit_data *sad = &ad->smack_audit_data;
ed5215a2	244	audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
d4131ded	245	ad->smack_audit_data.function,
ecfcc53f EB	246	sad->result ? "denied" : "granted");
	247	audit_log_format(ab, " subject=");
	248	audit_log_untrustedstring(ab, sad->subject);
	249	audit_log_format(ab, " object=");
	250	audit_log_untrustedstring(ab, sad->object);
	251	audit_log_format(ab, " requested=%s", sad->request);
	252	}
	253
	254	/**
	255	* smack_log - Audit the granting or denial of permissions.
	256	* @subject_label : smack label of the requester
	257	* @object_label : smack label of the object being accessed
	258	* @request: requested permissions
	259	* @result: result from smk_access
	260	* @a: auxiliary audit data
	261	*
	262	* Audit the granting or denial of permissions in accordance
	263	* with the policy.
	264	*/
	265	void smack_log(char subject_label, char object_label, int request,
	266	int result, struct smk_audit_info *ad)
	267	{
	268	char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
	269	struct smack_audit_data *sad;
	270	struct common_audit_data *a = &ad->a;
	271
	272	/* check if we have to log the current event */
	273	if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
	274	return;
	275	if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
	276	return;
	277
d4131ded TL	278	if (a->smack_audit_data.function == NULL)
d4131ded TL	279	a->smack_audit_data.function = "unknown";
ecfcc53f EB	280
ecfcc53f EB	281	/* end preparing the audit data */
d4131ded	282	sad = &a->smack_audit_data;
ecfcc53f EB	283	smack_str_from_perm(request_buffer, request);
	284	sad->subject = subject_label;
	285	sad->object = object_label;
	286	sad->request = request_buffer;
	287	sad->result = result;
	288	a->lsm_pre_audit = smack_log_callback;
	289
	290	common_lsm_audit(a);
	291	}
	292	#else /* #ifdef CONFIG_AUDIT */
	293	void smack_log(char subject_label, char object_label, int request,
	294	int result, struct smk_audit_info *ad)
	295	{
	296	}
	297	#endif
	298
e114e473 CS	299	static DEFINE_MUTEX(smack_known_lock);
	300
	301	/**
	302	* smk_import_entry - import a label, return the list entry
	303	* @string: a text string that might be a Smack label
	304	* @len: the maximum size, or zero if it is NULL terminated.
	305	*
	306	* Returns a pointer to the entry in the label list that
	307	* matches the passed string, adding it if necessary.
	308	*/
	309	struct smack_known smk_import_entry(const char string, int len)
	310	{
	311	struct smack_known *skp;
	312	char smack[SMK_LABELLEN];
	313	int found;
	314	int i;
	315
	316	if (len <= 0 \|\| len > SMK_MAXLEN)
	317	len = SMK_MAXLEN;
	318
	319	for (i = 0, found = 0; i < SMK_LABELLEN; i++) {
	320	if (found)
	321	smack[i] = '\0';
	322	else if (i >= len \|\| string[i] > '~' \|\| string[i] <= ' ' \|\|
ecfcc53f EB	323	string[i] == '/' \|\| string[i] == '"' \|\|
ecfcc53f EB	324	string[i] == '\\' \|\| string[i] == '\'') {
e114e473 CS	325	smack[i] = '\0';
	326	found = 1;
	327	} else
	328	smack[i] = string[i];
	329	}
	330
	331	if (smack[0] == '\0')
	332	return NULL;
	333
	334	mutex_lock(&smack_known_lock);
	335
7198e2ee EB	336	found = 0;
	337	list_for_each_entry_rcu(skp, &smack_known_list, list) {
	338	if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
	339	found = 1;
e114e473	340	break;
7198e2ee EB	341	}
7198e2ee EB	342	}
e114e473	343
7198e2ee	344	if (found == 0) {
e114e473 CS	345	skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
e114e473 CS	346	if (skp != NULL) {
e114e473 CS	347	strncpy(skp->smk_known, smack, SMK_MAXLEN);
	348	skp->smk_secid = smack_next_secid++;
	349	skp->smk_cipso = NULL;
	350	spin_lock_init(&skp->smk_cipsolock);
	351	/*
	352	* Make sure that the entry is actually
	353	* filled before putting it on the list.
	354	*/
7198e2ee	355	list_add_rcu(&skp->list, &smack_known_list);
e114e473 CS	356	}
	357	}
	358
	359	mutex_unlock(&smack_known_lock);
	360
	361	return skp;
	362	}
	363
	364	/**
	365	* smk_import - import a smack label
	366	* @string: a text string that might be a Smack label
	367	* @len: the maximum size, or zero if it is NULL terminated.
	368	*
	369	* Returns a pointer to the label in the label list that
	370	* matches the passed string, adding it if necessary.
	371	*/
	372	char smk_import(const char string, int len)
	373	{
	374	struct smack_known *skp;
	375
4303154e EB	376	/* labels cannot begin with a '-' */
	377	if (string[0] == '-')
	378	return NULL;
e114e473 CS	379	skp = smk_import_entry(string, len);
	380	if (skp == NULL)
	381	return NULL;
	382	return skp->smk_known;
	383	}
	384
	385	/**
	386	* smack_from_secid - find the Smack label associated with a secid
	387	* @secid: an integer that might be associated with a Smack label
	388	*
	389	* Returns a pointer to the appropraite Smack label if there is one,
	390	* otherwise a pointer to the invalid Smack label.
	391	*/
	392	char *smack_from_secid(const u32 secid)
	393	{
	394	struct smack_known *skp;
	395
7198e2ee EB	396	rcu_read_lock();
	397	list_for_each_entry_rcu(skp, &smack_known_list, list) {
	398	if (skp->smk_secid == secid) {
	399	rcu_read_unlock();
e114e473	400	return skp->smk_known;
7198e2ee EB	401	}
7198e2ee EB	402	}
e114e473 CS	403
	404	/*
	405	* If we got this far someone asked for the translation
	406	* of a secid that is not on the list.
	407	*/
7198e2ee	408	rcu_read_unlock();
e114e473 CS	409	return smack_known_invalid.smk_known;
	410	}
	411
	412	/**
	413	* smack_to_secid - find the secid associated with a Smack label
	414	* @smack: the Smack label
	415	*
	416	* Returns the appropriate secid if there is one,
	417	* otherwise 0
	418	*/
	419	u32 smack_to_secid(const char *smack)
	420	{
	421	struct smack_known *skp;
	422
7198e2ee EB	423	rcu_read_lock();
	424	list_for_each_entry_rcu(skp, &smack_known_list, list) {
	425	if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
	426	rcu_read_unlock();
e114e473	427	return skp->smk_secid;
7198e2ee EB	428	}
	429	}
	430	rcu_read_unlock();
e114e473 CS	431	return 0;
	432	}
	433
	434	/**
	435	* smack_from_cipso - find the Smack label associated with a CIPSO option
	436	* @level: Bell & LaPadula level from the network
	437	* @cp: Bell & LaPadula categories from the network
	438	* @result: where to put the Smack value
	439	*
	440	* This is a simple lookup in the label table.
	441	*
	442	* This is an odd duck as far as smack handling goes in that
	443	* it sends back a copy of the smack label rather than a pointer
	444	* to the master list. This is done because it is possible for
	445	* a foreign host to send a smack label that is new to this
	446	* machine and hence not on the list. That would not be an
	447	* issue except that adding an entry to the master list can't
	448	* be done at that point.
	449	*/
	450	void smack_from_cipso(u32 level, char cp, char result)
	451	{
	452	struct smack_known *kp;
	453	char *final = NULL;
	454
7198e2ee EB	455	rcu_read_lock();
7198e2ee EB	456	list_for_each_entry(kp, &smack_known_list, list) {
e114e473 CS	457	if (kp->smk_cipso == NULL)
	458	continue;
	459
	460	spin_lock_bh(&kp->smk_cipsolock);
	461
	462	if (kp->smk_cipso->smk_level == level &&
	463	memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0)
	464	final = kp->smk_known;
	465
	466	spin_unlock_bh(&kp->smk_cipsolock);
	467	}
7198e2ee	468	rcu_read_unlock();
e114e473 CS	469	if (final == NULL)
	470	final = smack_known_huh.smk_known;
	471	strncpy(result, final, SMK_MAXLEN);
	472	return;
	473	}
	474
	475	/**
	476	* smack_to_cipso - find the CIPSO option to go with a Smack label
	477	* @smack: a pointer to the smack label in question
	478	* @cp: where to put the result
	479	*
	480	* Returns zero if a value is available, non-zero otherwise.
	481	*/
	482	int smack_to_cipso(const char smack, struct smack_cipso cp)
	483	{
	484	struct smack_known *kp;
7198e2ee	485	int found = 0;
e114e473	486
7198e2ee EB	487	rcu_read_lock();
7198e2ee EB	488	list_for_each_entry_rcu(kp, &smack_known_list, list) {
e114e473	489	if (kp->smk_known == smack \|\|
7198e2ee EB	490	strcmp(kp->smk_known, smack) == 0) {
7198e2ee EB	491	found = 1;
e114e473	492	break;
7198e2ee EB	493	}
	494	}
	495	rcu_read_unlock();
e114e473	496
7198e2ee	497	if (found == 0 \|\| kp->smk_cipso == NULL)
e114e473 CS	498	return -ENOENT;
	499
	500	memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
	501	return 0;
	502	}