path: root/kernel/auditsc.c

/* auditsc.c -- System-call auditing support
 * Handles all system-call specific auditing features.
 *
 * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
 * Copyright 2005 Hewlett-Packard Development Company, L.P.
 * Copyright (C) 2005 IBM Corporation
 * All Rights Reserved.
 *
 * 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
 *
 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
 *
 * Many of the ideas implemented here are from Stephen C. Tweedie,
 * especially the idea of avoiding a copy by using getname.
 *
 * The method for actual interception of syscall entry and exit (not in
 * this file -- see entry.S) is based on a GPL'd patch written by
 * okir@suse.de and Copyright 2003 SuSE Linux AG.
 *
 * The support of additional filter rules compares (>, <, >=, <=) was
 * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
 *
 * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
 * filesystem information.
 *
 * Subject and object context labeling support added by <danjones@us.ibm.com>
 * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.
 */

#include <linux/init.h>
#include <asm/types.h>
#include <asm/atomic.h>
#include <asm/types.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/socket.h>
#include <linux/audit.h>
#include <linux/personality.h>
#include <linux/time.h>
#include <linux/netlink.h>
#include <linux/compiler.h>
#include <asm/unistd.h>
#include <linux/security.h>
#include <linux/list.h>
#include <linux/tty.h>

#include "audit.h"

extern struct list_head audit_filter_list[];

/* No syscall auditing will take place unless audit_enabled != 0. */
extern int audit_enabled;

/* AUDIT_NAMES is the number of slots we reserve in the audit_context
 * for saving names from getname(). */
#define AUDIT_NAMES    20

/* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
 * audit_context from being used for nameless inodes from
 * path_lookup. */
#define AUDIT_NAMES_RESERVED 7

/* When fs/namei.c:getname() is called, we store the pointer in name and
 * we don't let putname() free it (instead we free all of the saved
 * pointers at syscall exit time).
 *
 * Further, in fs/namei.c:path_lookup() we store the inode and device. */
struct audit_names {
	const char	*name;
	unsigned long	ino;
	unsigned long	pino;
	dev_t		dev;
	umode_t		mode;
	uid_t		uid;
	gid_t		gid;
	dev_t		rdev;
	char		*ctx;
};

struct audit_aux_data {
	struct audit_aux_data	*next;
	int			type;
};

#define AUDIT_AUX_IPCPERM	0

struct audit_aux_data_ipcctl {
	struct audit_aux_data	d;
	struct ipc_perm		p;
	unsigned long		qbytes;
	uid_t			uid;
	gid_t			gid;
	mode_t			mode;
	char 			*ctx;
};

struct audit_aux_data_socketcall {
	struct audit_aux_data	d;
	int			nargs;
	unsigned long		args[0];
};

struct audit_aux_data_sockaddr {
	struct audit_aux_data	d;
	int			len;
	char			a[0];
};

struct audit_aux_data_path {
	struct audit_aux_data	d;
	struct dentry		*dentry;
	struct vfsmount		*mnt;
};

/* The per-task audit context. */
struct audit_context {
	int		    in_syscall;	/* 1 if task is in a syscall */
	enum audit_state    state;
	unsigned int	    serial;     /* serial number for record */
	struct timespec	    ctime;      /* time of syscall entry */
	uid_t		    loginuid;   /* login uid (identity) */
	int		    major;      /* syscall number */
	unsigned long	    argv[4];    /* syscall arguments */
	int		    return_valid; /* return code is valid */
	long		    return_code;/* syscall return code */
	int		    auditable;  /* 1 if record should be written */
	int		    name_count;
	struct audit_names  names[AUDIT_NAMES];
	struct dentry *	    pwd;
	struct vfsmount *   pwdmnt;
	struct audit_context *previous; /* For nested syscalls */
	struct audit_aux_data *aux;

				/* Save things to print about task_struct */
	pid_t		    pid;
	uid_t		    uid, euid, suid, fsuid;
	gid_t		    gid, egid, sgid, fsgid;
	unsigned long	    personality;
	int		    arch;

#if AUDIT_DEBUG
	int		    put_count;
	int		    ino_count;
#endif
};


/* Compare a task_struct with an audit_rule.  Return 1 on match, 0
 * otherwise. */
static int audit_filter_rules(struct task_struct *tsk,
			      struct audit_krule *rule,
			      struct audit_context *ctx,
			      enum audit_state *state)
{
	int i, j;

	for (i = 0; i < rule->field_count; i++) {
		struct audit_field *f = &rule->fields[i];
		int result = 0;

		switch (f->type) {
		case AUDIT_PID:
			result = audit_comparator(tsk->pid, f->op, f->val);
			break;
		case AUDIT_UID:
			result = audit_comparator(tsk->uid, f->op, f->val);
			break;
		case AUDIT_EUID:
			result = audit_comparator(tsk->euid, f->op, f->val);
			break;
		case AUDIT_SUID:
			result = audit_comparator(tsk->suid, f->op, f->val);
			break;
		case AUDIT_FSUID:
			result = audit_comparator(tsk->fsuid, f->op, f->val);
			break;
		case AUDIT_GID:
			result = audit_comparator(tsk->gid, f->op, f->val);
			break;