[PATCH 8/9] SELinux: use new audit hooks, remove redundant exports

Ahmed S. Darwish
2008-03-01T20:06:39Z

Setup the new Audit LSM hooks for SELinux.
Remove the now redundant exported SELinux Audit interface.

Audit: Export 'audit_krule' and 'audit_field' to the public
since their internals are needed by the implementation of the
new LSM hook 'audit_rule_known'.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
---

include/linux/audit.h | 29 +++++++++++++++
include/linux/selinux.h | 72 ---------------------------------------
kernel/audit.h | 25 -------------
security/selinux/hooks.c | 8 ++++
security/selinux/include/audit.h | 65 +++++++++++++++++++++++++++++++++++
security/selinux/ss/services.c | 44 +++++++++++++++++------
6 files changed, 135 insertions(+), 108 deletions(-)

diff --git a/include/linux/selinux.h b/include/linux/selinux.h
index 24b0af1..20f965d 100644
--- a/include/linux/selinux.h
+++ b/include/linux/selinux.h
@@ -21,54 +21,6 @@ struct kern_ipc_perm;
#ifdef CONFIG_SECURITY_SELINUX

/**
- * selinux_audit_rule_init - alloc/init an selinux audit rule structure.
- * @field: the field this rule refers to
- * @op: the operater the rule uses
- * @rulestr: the text "target" of the rule
- * @rule: pointer to the new rule structure returned via this
- *
- * Returns 0 if successful, -errno if not. On success, the rule structure
- * will be allocated internally. The caller must free this structure with
- * selinux_audit_rule_free() after use.
- */
-int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
- struct selinux_audit_rule **rule);
-
-/**
- * selinux_audit_rule_free - free an selinux audit rule structure.
- * @rule: pointer to the audit rule to be freed
- *
- * This will free all memory associated with the given rule.
- * If @rule is NULL, no operation is performed.
- */
-void selinux_audit_rule_free(struct selinux_audit_rule *rule);
-
-/**
- * selinux_audit_rule_match - determine if a context ID matches a rule.
- * @sid: the context ID to check
- * @field: the field this rule refers to
- * @op: the operater the rule uses
- * @rule: pointer to the audit rule to check against
- * @actx: the audit context (can be NULL) associated with the check
- *
- * Returns 1 if the context id matches the rule, 0 if it does not, and
- * -errno on failure.
- */
-int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
- struct selinux_audit_rule *rule,
- struct audit_context *actx);
-
-/**
- * selinux_audit_set_callback - set the callback for policy reloads.
- * @callback: the function to call when the policy is reloaded
- *
- * This sets the function callback function that will update the rules
- * upon policy reloads. This callback should rebuild all existing rules
- * using selinux_audit_rule_init().
- */
-void selinux_audit_set_callback(int (*callback)(void));
-
-/**
* selinux_string_to_sid - map a security context string to a security ID
* @str: the security context string to be mapped
* @sid: ID value returned via this.
@@ -111,30 +63,6 @@ void selinux_secmark_refcount_inc(void);
void selinux_secmark_refcount_dec(void);
#else

-static inline int selinux_audit_rule_init(u32 field, u32 op,
- char *rulestr,
- struct selinux_audit_rule **rule)
-{
- return -EOPNOTSUPP;
-}
-
-static inline void selinux_audit_rule_free(struct selinux_audit_rule *rule)
-{
- return;
-}
-
-static inline int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
- struct selinux_audit_rule *rule,
- struct audit_context *actx)
-{
- return 0;
-}
-
-static inline void selinux_audit_set_callback(int (*callback)(void))
-{
- return;
-}
-
static inline int selinux_string_to_sid(const char *str, u32 *sid)
{
*sid = 0;
diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h
new file mode 100644
index 0000000..6c8b9ef
--- /dev/null
+++ b/security/selinux/include/audit.h
@@ -0,0 +1,65 @@
+/*
+ * SELinux support for the Audit LSM hooks
+ *
+ * Most of below header was moved from include/linux/selinux.h which
+ * is released under below copyrights:
+ *
+ * Author: James Morris <jmorris@redhat.com>
+ *
+ * Copyright (C) 2005 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ * Copyright (C) 2006 Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
+ * Copyright (C) 2006 IBM Corporation, Timothy R. Chavez <tinytim@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+
+#ifndef _SELINUX_AUDIT_H
+#define _SELINUX_AUDIT_H
+
+/**
+ * selinux_audit_rule_init - alloc/init an selinux audit rule structure.
+ * @field: the field this rule refers to
+ * @op: the operater the rule uses
+ * @rulestr: the text "target" of the rule
+ * @rule: pointer to the new rule structure returned via this
+ *
+ * Returns 0 if successful, -errno if not. On success, the rule structure
+ * will be allocated internally. The caller must free this structure with
+ * selinux_audit_rule_free() after use.
+ */
+int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **rule);
+
+/**
+ * selinux_audit_rule_free - free an selinux audit rule structure.
+ * @rule: pointer to the audit rule to be freed
+ *
+ * This will free all memory associated with the given rule.
+ * If @rule is NULL, no operation is performed.
+ */
+void selinux_audit_rule_free(void *rule);
+
+/**
+ * selinux_audit_rule_match - determine if a context ID matches a rule.
+ * @sid: the context ID to check
+ * @field: the field this rule refers to
+ * @op: the operater the rule uses
+ * @rule: pointer to the audit rule to check against
+ * @actx: the audit context (can be NULL) associated with the check
+ *
+ * Returns 1 if the context id matches the rule, 0 if it does not, and
+ * -errno on failure.
+ */
+int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *rule,
+ struct audit_context *actx);
+
+/**
+ * selinux_audit_rule_known - check to see if rule contains selinux fields.
+ * @rule: rule to be checked
+ * Returns 1 if there are selinux fields specified in the rule, 0 otherwise.
+ */
+int selinux_audit_rule_known(struct audit_krule *krule);
+
+#endif /* _SELINUX_AUDIT_H */
+
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 06597d7..bef1834 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -82,6 +82,7 @@
#include "netnode.h"
#include "xfrm.h"
#include "netlabel.h"
+#include "audit.h"

#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
@@ -5429,6 +5430,13 @@ static struct security_operations selinux_ops = {
.key_permission = selinux_key_permission,
.key_getsecurity = selinux_key_getsecurity,
#endif
+
+#ifdef CONFIG_AUDIT
+ .audit_rule_init = selinux_audit_rule_init,
+ .audit_rule_known = selinux_audit_rule_known,
+ .audit_rule_match = selinux_audit_rule_match,
+ .audit_rule_free = selinux_audit_rule_free,
+#endif
};

static __init int selinux_init(void)
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index f374186..7094623 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -56,6 +56,7 @@
#include "netlabel.h"
#include "xfrm.h"
#include "ebitmap.h"
+#include "audit.h"

extern void selnl_notify_policyload(u32 seqno);
unsigned int policydb_loaded_version;
@@ -2271,21 +2272,23 @@ struct selinux_audit_rule {
struct context au_ctxt;
};

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

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

*rule = NULL;
@@ -2372,12 +2375,37 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
return rc;
}

-int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
- struct selinux_audit_rule *rule,
+/* Check to see if the rule contains any selinux fields */
+int selinux_audit_rule_known(struct audit_krule *rule)
+{
+ int i;
+
+ for (i = 0; i < rule->field_count; i++) {
+ struct audit_field *f = &rule->fields[i];
+ switch (f->type) {
+ case AUDIT_SUBJ_USER:
+ case AUDIT_SUBJ_ROLE:
+ case AUDIT_SUBJ_TYPE:
+ case AUDIT_SUBJ_SEN:
+ case AUDIT_SUBJ_CLR:
+ case AUDIT_OBJ_USER:
+ case AUDIT_OBJ_ROLE:
+ case AUDIT_OBJ_TYPE:
+ case AUDIT_OBJ_LEV_LOW:
+ case AUDIT_OBJ_LEV_HIGH:
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
struct audit_context *actx)
{
struct context *ctxt;
struct mls_level *level;
+ struct selinux_audit_rule *rule = vrule;
int match = 0;

if (!rule) {
@@ -2484,7 +2512,7 @@ out:
return match;
}

-static int (*aurule_callback)(void) = NULL;
+static int (*aurule_callback)(void) = audit_update_lsm_rules;

static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
u16 class, u32 perms, u32 *retained)
@@ -2509,11 +2537,6 @@ static int __init aurule_init(void)
}
__initcall(aurule_init);

-void selinux_audit_set_callback(int (*callback)(void))
-{
- aurule_callback = callback;
-}
-
#ifdef CONFIG_NETLABEL
/**
* security_netlbl_cache_add - Add an entry to the NetLabel cache
diff --git a/kernel/audit.h b/kernel/audit.h
index 2554bd5..3cfc54e 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -65,34 +65,9 @@ struct audit_watch {
struct list_head rules; /* associated rules */
};

-struct audit_field {
- u32 type;
- u32 val;
- u32 op;
- char *se_str;
- struct selinux_audit_rule *se_rule;
-};
-
struct audit_tree;
struct audit_chunk;

-struct audit_krule {
- int vers_ops;
- u32 flags;
- u32 listnr;
- u32 action;
- u32 mask[AUDIT_BITMASK_SIZE];
- u32 buflen; /* for data alloc on list rules */
- u32 field_count;
- char *filterkey; /* ties events to rules */
- struct audit_field *fields;
- struct audit_field *arch_f; /* quick access to arch field */
- struct audit_field *inode_f; /* quick access to an inode field */
- struct audit_watch *watch; /* associated watch */
- struct audit_tree *tree; /* associated watched tree */
- struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
-};
-
struct audit_entry {
struct list_head list;
struct rcu_head rcu;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 2af9ec0..3367c80 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -353,6 +353,33 @@ struct netlink_skb_parms;
struct linux_binprm;
struct mq_attr;
struct mqstat;
+struct audit_watch;
+struct audit_tree;
+
+struct audit_krule {
+ int vers_ops;
+ u32 flags;
+ u32 listnr;
+ u32 action;
+ u32 mask[AUDIT_BITMASK_SIZE];
+ u32 buflen; /* for data alloc on list rules */
+ u32 field_count;
+ char *filterkey; /* ties events to rules */
+ struct audit_field *fields;
+ struct audit_field *arch_f; /* quick access to arch field */
+ struct audit_field *inode_f; /* quick access to an inode field */
+ struct audit_watch *watch; /* associated watch */
+ struct audit_tree *tree; /* associated watched tree */
+ struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
+};
+
+struct audit_field {
+ u32 type;
+ u32 val;
+ u32 op;
+ char *se_str;
+ void *se_rule;
+};

#define AUDITSC_INVALID 0
#define AUDITSC_SUCCESS 1
@@ -536,6 +563,8 @@ extern void audit_log_d_path(struct audit_buffer *ab,
const char *prefix,
struct path *path);
extern void audit_log_lost(const char *message);
+extern int audit_update_lsm_rules(void);
+
/* Private API (for audit.c only) */
extern int audit_filter_user(struct netlink_skb_parms *cb, int type);
extern int audit_filter_type(int type);

--

"Better to light a candle, than curse the darkness"

Ahmed S. Darwish
Homepage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com