* entry is found returns -ENOENT.
*
* NOTE:
- * 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.
+ * Earlier versions of this function allowed for labels that
+ * were not on the label list. This was done to allow for
+ * labels to come over the network that had never been seen
+ * before on this host. Unless the receiving socket has the
+ * star label this will always result in a failure check. The
+ * star labeled socket case is now handled in the networking
+ * hooks so there is no case where the label is not on the
+ * label list. Checking to see if the address of two labels
+ * is the same is now a reliable test.
+ *
+ * Do the object check first because that is more
+ * likely to differ.
*/
int smk_access_entry(char *subject_label, char *object_label,
struct list_head *rule_list)
struct smack_rule *srp;
list_for_each_entry_rcu(srp, 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;
- }
+ if (srp->smk_object == object_label &&
+ srp->smk_subject == subject_label) {
+ may = srp->smk_access;
+ break;
}
}
* 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.
+ * Smack labels are shared on smack_list
*/
int smk_access(char *subject_label, char *object_label, int request,
struct smk_audit_info *a)
{
+ struct smack_known *skp;
int may = MAY_NOT;
int rc = 0;
*
* 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) {
+ if (subject_label == smack_known_star.smk_known) {
rc = -EACCES;
goto out_audit;
}
* 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)
+ subject_label == smack_known_web.smk_known)
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)
+ if (object_label == smack_known_star.smk_known)
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)
+ if (subject_label == object_label)
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)
+ if (object_label == smack_known_floor.smk_known)
goto out_audit;
- if (subject_label == smack_known_hat.smk_known ||
- strcmp(subject_label, smack_known_hat.smk_known) == 0)
+ if (subject_label == smack_known_hat.smk_known)
goto out_audit;
}
/*
* good. A negative response from smk_access_entry()
* indicates there is no entry for this pair.
*/
+ skp = smk_find_entry(subject_label);
rcu_read_lock();
- may = smk_access_entry(subject_label, object_label, &smack_rule_list);
+ may = smk_access_entry(subject_label, object_label, &skp->smk_rules);
rcu_read_unlock();
if (may > 0 && (request & may) == request)
static DEFINE_MUTEX(smack_known_lock);
/**
- * smk_import_entry - import a label, return the list entry
+ * smk_find_entry - find a label on the list, 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.
+ * matches the passed string.
*/
-struct smack_known *smk_import_entry(const char *string, int len)
+struct smack_known *smk_find_entry(const char *string)
{
struct smack_known *skp;
- char smack[SMK_LABELLEN];
+
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, string, SMK_MAXLEN) == 0)
+ return skp;
+ }
+
+ return NULL;
+}
+
+/**
+ * smk_parse_smack - parse smack label from a text string
+ * @string: a text string that might contain a Smack label
+ * @len: the maximum size, or zero if it is NULL terminated.
+ * @smack: parsed smack label, or NULL if parse error
+ */
+void smk_parse_smack(const char *string, int len, char *smack)
+{
int found;
int i;
} else
smack[i] = string[i];
}
+}
+
+/**
+ * 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];
+ smk_parse_smack(string, len, smack);
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;
- }
- }
+ skp = smk_find_entry(smack);
- if (found == 0) {
+ if (skp == NULL) {
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;
+ INIT_LIST_HEAD(&skp->smk_rules);
spin_lock_init(&skp->smk_cipsolock);
+ mutex_init(&skp->smk_rules_lock);
/*
* Make sure that the entry is actually
* filled before putting it on the list.
* 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.
+ * Return the matching label from the label list or NULL.
*/
-void smack_from_cipso(u32 level, char *cp, char *result)
+char *smack_from_cipso(u32 level, char *cp)
{
struct smack_known *kp;
char *final = NULL;
final = kp->smk_known;
spin_unlock_bh(&kp->smk_cipsolock);
+
+ if (final != NULL)
+ break;
}
rcu_read_unlock();
- if (final == NULL)
- final = smack_known_huh.smk_known;
- strncpy(result, final, SMK_MAXLEN);
- return;
+
+ return final;
}
/**
projects / linux-2.6-block.git / blobdiff