kernel-ark/kernel/audit.h
Amy Griffis f368c07d72 [PATCH] audit: path-based rules
In this implementation, audit registers inotify watches on the parent
directories of paths specified in audit rules.  When audit's inotify
event handler is called, it updates any affected rules based on the
filesystem event.  If the parent directory is renamed, removed, or its
filesystem is unmounted, audit removes all rules referencing that
inotify watch.

To keep things simple, this implementation limits location-based
auditing to the directory entries in an existing directory.  Given
a path-based rule for /foo/bar/passwd, the following table applies:

    passwd modified -- audit event logged
    passwd replaced -- audit event logged, rules list updated
    bar renamed     -- rule removed
    foo renamed     -- untracked, meaning that the rule now applies to
		       the new location

Audit users typically want to have many rules referencing filesystem
objects, which can significantly impact filtering performance.  This
patch also adds an inode-number-based rule hash to mitigate this
situation.

The patch is relative to the audit git tree:
http://kernel.org/git/?p=linux/kernel/git/viro/audit-current.git;a=summary
and uses the inotify kernel API:
http://lkml.org/lkml/2006/6/1/145

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-06-20 05:25:27 -04:00

145 lines
4.5 KiB
C

/* 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_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;
struct audit_field *fields;
struct audit_field *inode_f; /* quick access to an inode field */
struct audit_watch *watch; /* associated watch */
struct list_head rlist; /* entry in audit_watch.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_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_compare_dname_path(const char *dname, const char *path);
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_log_lost(const char *message);
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);
#ifdef CONFIG_AUDITSYSCALL
extern void __audit_signal_info(int sig, struct task_struct *t);
static inline void audit_signal_info(int sig, struct task_struct *t)
{
if (unlikely(audit_pid && t->tgid == audit_pid))
__audit_signal_info(sig, t);
}
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)
#define audit_filter_inodes(t,c) AUDIT_DISABLED
#define audit_set_auditable(c)
#endif