smack: implement logging V3

This patch creates auditing functions usable by LSM to audit security
events. It provides standard dumping of FS, NET, task etc ... events
(code borrowed from SELinux)
and provides 2 callbacks to define LSM specific auditing, which should be
flexible enough to convert SELinux too.

Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
cked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 111 insertions, 0 deletions

diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
new file mode 100644
index 00000000000..e461b2c3d71
--- /dev/null
+++ b/include/linux/lsm_audit.h
@@ -0,0 +1,111 @@
+/*
+ * Common LSM logging functions
+ * Heavily borrowed from selinux/avc.h
+ *
+ * Author : Etienne BASSET  <etienne.basset@ensta.org>
+ *
+ * All credits to : Stephen Smalley, <sds@epoch.ncsc.mil>
+ * All BUGS to : Etienne BASSET  <etienne.basset@ensta.org>
+ */
+#ifndef _LSM_COMMON_LOGGING_
+#define _LSM_COMMON_LOGGING_
+
+#include <linux/stddef.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kdev_t.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/audit.h>
+#include <linux/in6.h>
+#include <linux/path.h>
+#include <linux/key.h>
+#include <linux/skbuff.h>
+#include <asm/system.h>
+
+
+/* Auxiliary data to use in generating the audit record. */
+struct common_audit_data {
+	char    type;
+#define LSM_AUDIT_DATA_FS      1
+#define LSM_AUDIT_DATA_NET     2
+#define LSM_AUDIT_DATA_CAP     3
+#define LSM_AUDIT_DATA_IPC     4
+#define LSM_AUDIT_DATA_TASK    5
+#define LSM_AUDIT_DATA_KEY     6
+	struct task_struct *tsk;
+	union 	{
+		struct {
+			struct path path;
+			struct inode *inode;
+		} fs;
+		struct {
+			int netif;
+			struct sock *sk;
+			u16 family;
+			__be16 dport;
+			__be16 sport;
+			union {
+				struct {
+					__be32 daddr;
+					__be32 saddr;
+				} v4;
+				struct {
+					struct in6_addr daddr;
+					struct in6_addr saddr;
+				} v6;
+			} fam;
+		} net;
+		int cap;
+		int ipc_id;
+		struct task_struct *tsk;
+#ifdef CONFIG_KEYS
+		struct {
+			key_serial_t key;
+			char *key_desc;
+		} key_struct;
+#endif
+	} u;
+	const char *function;
+	/* this union contains LSM specific data */
+	union {
+		/* SMACK data */
+		struct smack_audit_data {
+			char *subject;
+			char *object;
+			char *request;
+			int result;
+		} smack_audit_data;
+		/* SELinux data */
+		struct {
+			u32 ssid;
+			u32 tsid;
+			u16 tclass;
+			u32 requested;
+			u32 audited;
+			struct av_decision *avd;
+			int result;
+		} selinux_audit_data;
+	} lsm_priv;
+	/* these callback will be implemented by a specific LSM */
+	void (*lsm_pre_audit)(struct audit_buffer *, void *);
+	void (*lsm_post_audit)(struct audit_buffer *, void *);
+};
+
+#define v4info fam.v4
+#define v6info fam.v6
+
+int ipv4_skb_to_auditdata(struct sk_buff *skb,
+		struct common_audit_data *ad, u8 *proto);
+
+int ipv6_skb_to_auditdata(struct sk_buff *skb,
+		struct common_audit_data *ad, u8 *proto);
+
+/* Initialize an LSM audit data structure. */
+#define COMMON_AUDIT_DATA_INIT(_d, _t) \
+	{ memset((_d), 0, sizeof(struct common_audit_data)); \
+	 (_d)->type = LSM_AUDIT_DATA_##_t; (_d)->function = __func__; }
+
+void common_lsm_audit(struct common_audit_data *a);
+
+#endif