/* audit -- definition of audit_context structure and supporting types 
 *
 * Copyright 2003-2004 Red Hat, Inc.
 * Copyright 2005 Hewlett-Packard Development Company, L.P.
 * Copyright 2005 IBM Corporation
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/fs.h>
#include <linux/audit.h>
#include <linux/skbuff.h>

/* 0 = no checking
   1 = put_count checking
   2 = verbose put_count checking
*/
#define AUDIT_DEBUG 0

/* At task start time, the audit_state is set in the audit_context using
   a per-task filter.  At syscall entry, the audit_state is augmented by
   the syscall filter. */
enum audit_state {
	AUDIT_DISABLED,		/* Do not create per-task audit_context.
				 * No syscall-specific audit records can
				 * be generated. */
	AUDIT_SETUP_CONTEXT,	/* Create the per-task audit_context,
				 * but don't necessarily fill it in at
				 * syscall entry time (i.e., filter
				 * instead). */
	AUDIT_BUILD_CONTEXT,	/* Create the per-task audit_context,
				 * and always fill it in at syscall
				 * entry time.  This makes a full
				 * syscall record available if some
				 * other part of the kernel decides it
				 * should be recorded. */
	AUDIT_RECORD_CONTEXT	/* Create the per-task audit_context,
				 * always fill it in at syscall entry
				 * time, and always write out the audit
				 * record at syscall exit time.  */
};

/* Rule lists */
struct audit_parent;

struct audit_watch {
	atomic_t		count;	/* reference count */
	char			*path;	/* insertion path */
	dev_t			dev;	/* associated superblock device */
	unsigned long		ino;	/* associated inode number */
	struct audit_parent	*parent; /* associated parent */
	struct list_head	wlist;	/* entry in parent->watches list */
	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;
	struct audit_krule	rule;
};

extern int audit_pid;

#define AUDIT_INODE_BUCKETS	32
extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];

static inline int audit_hash_ino(u32 ino)
{
	return (ino & (AUDIT_INODE_BUCKETS-1));
}

extern int audit_match_class(int class, unsigned syscall);
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_compare_dname_path(const char *dname, const char *path,
				    int *dirlen);
extern struct sk_buff *	    audit_make_reply(int pid, int seq, int type,
					     int done, int multi,
					     void *payload, int size);
extern void		    audit_send_reply(int pid, int seq, int type,
					     int done, int multi,
					     void *payload, int size);
extern void		    audit_panic(const char *message);

struct audit_netlink_list {
	int pid;
	struct sk_buff_head q;
};

int audit_send_list(void *);

struct inotify_watch;
extern void audit_free_parent(struct inotify_watch *);
extern void audit_handle_ievent(struct inotify_watch *, u32, u32, u32,
				const char *, struct inode *);
extern int selinux_audit_rule_update(void);

extern struct mutex audit_filter_mutex;
extern void audit_free_rule_rcu(struct rcu_head *);

#ifdef CONFIG_AUDIT_TREE
extern struct audit_chunk *audit_tree_lookup(const struct inode *);
extern void audit_put_chunk(struct audit_chunk *);
extern int audit_tree_match(struct audit_chunk *, struct audit_tree *);
extern int audit_make_tree(struct audit_krule *, char *, u32);
extern int audit_add_tree_rule(struct audit_krule *);
extern int audit_remove_tree_rule(struct audit_krule *);
extern void audit_trim_trees(void);
extern int audit_tag_tree(char *old, char *new);
extern void audit_schedule_prune(void);
extern void audit_prune_trees(void);
extern const char *audit_tree_path(struct audit_tree *);
extern void audit_put_tree(struct audit_tree *);
#else
#define audit_remove_tree_rule(rule) BUG()
#define audit_add_tree_rule(rule) -EINVAL
#define audit_make_tree(rule, str, op) -EINVAL
#define audit_trim_trees() (void)0
#define audit_put_tree(tree) (void)0
#define audit_tag_tree(old, new) -EINVAL
#define audit_tree_path(rule) ""	/* never called */
#endif

extern char *audit_unpack_string(void **, size_t *, size_t);

#ifdef CONFIG_AUDITSYSCALL
extern int __audit_signal_info(int sig, struct task_struct *t);
static inline int audit_signal_info(int sig, struct task_struct *t)
{
	if (unlikely((audit_pid && t->tgid == audit_pid) ||
		     (audit_signals && !audit_dummy_context())))
		return __audit_signal_info(sig, t);
	return 0;
}
extern enum audit_state audit_filter_inodes(struct task_struct *,
					    struct audit_context *);
extern void audit_set_auditable(struct audit_context *);
#else
#define audit_signal_info(s,t) AUDIT_DISABLED
#define audit_filter_inodes(t,c) AUDIT_DISABLED
#define audit_set_auditable(c)
#endif