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-rw-r--r--security/selinux/ss/services.c235
1 files changed, 234 insertions, 1 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 61492485de84..7177e98df7f3 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -7,12 +7,13 @@
* Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
*
* Support for enhanced MLS infrastructure.
+ * Support for context based audit filters.
*
* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
- * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
+ * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
* This program is free software; you can redistribute it and/or modify
@@ -1811,3 +1812,235 @@ out:
POLICY_RDUNLOCK;
return rc;
}
+
+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) {
+ case AUDIT_SE_USER:
+ case AUDIT_SE_ROLE:
+ case AUDIT_SE_TYPE:
+ /* only 'equals' and 'not equals' fit user, role, and type */
+ if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
+ return -EINVAL;
+ break;
+ case AUDIT_SE_SEN:
+ case AUDIT_SE_CLR:
+ /* 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) {
+ case AUDIT_SE_USER:
+ userdatum = hashtab_search(policydb.p_users.table, rulestr);
+ if (!userdatum)
+ rc = -EINVAL;
+ else
+ tmprule->au_ctxt.user = userdatum->value;
+ break;
+ case AUDIT_SE_ROLE:
+ roledatum = hashtab_search(policydb.p_roles.table, rulestr);
+ if (!roledatum)
+ rc = -EINVAL;
+ else
+ tmprule->au_ctxt.role = roledatum->value;
+ break;
+ case AUDIT_SE_TYPE:
+ typedatum = hashtab_search(policydb.p_types.table, rulestr);
+ if (!typedatum)
+ rc = -EINVAL;
+ else
+ tmprule->au_ctxt.type = typedatum->value;
+ break;
+ case AUDIT_SE_SEN:
+ case AUDIT_SE_CLR:
+ 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;
+}
+
+int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
+ 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;
+ }
+
+ ctxt = sidtab_search(&sidtab, ctxid);
+ if (!ctxt) {
+ audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
+ "selinux_audit_rule_match: unrecognized SID %d\n",
+ ctxid);
+ match = -ENOENT;
+ goto out;
+ }
+
+ /* a field/op pair that is not caught here will simply fall through
+ without a match */
+ switch (field) {
+ case AUDIT_SE_USER:
+ switch (op) {
+ case AUDIT_EQUAL:
+ match = (ctxt->user == rule->au_ctxt.user);
+ break;
+ case AUDIT_NOT_EQUAL:
+ match = (ctxt->user != rule->au_ctxt.user);
+ break;
+ }
+ break;
+ case AUDIT_SE_ROLE:
+ switch (op) {
+ case AUDIT_EQUAL:
+ match = (ctxt->role == rule->au_ctxt.role);
+ break;
+ case AUDIT_NOT_EQUAL:
+ match = (ctxt->role != rule->au_ctxt.role);
+ break;
+ }
+ break;
+ case AUDIT_SE_TYPE:
+ switch (op) {
+ case AUDIT_EQUAL:
+ match = (ctxt->type == rule->au_ctxt.type);
+ break;
+ case AUDIT_NOT_EQUAL:
+ match = (ctxt->type != rule->au_ctxt.type);
+ break;
+ }
+ break;
+ case AUDIT_SE_SEN:
+ case AUDIT_SE_CLR:
+ level = (op == AUDIT_SE_SEN ?
+ &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;
+}