freebsd-dev/sys/security/lomac/kernel_lkm.c

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/*-
* Copyright (c) 2001 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by NAI Labs, the
* Security Research Division of Network Associates, Inc. under
* DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA
* CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include "kernel_interface.h"
#include "kernel_mediate.h"
#include "kernel_plm.h"
#include "kernel_util.h"
#include "kernel_pipe.h"
#include "kernel_socket.h"
#include "lomacfs.h"
#include "lomacio.h"
static d_ioctl_t lomac_ioctl;
#define CDEV_MAJOR 207
#define LOMAC_MINOR 0
static struct cdevsw lomac_cdevsw = {
/* open */ (d_open_t *)nullop,
/* close */ (d_open_t *)nullop,
/* read */ noread,
/* write */ nowrite,
/* ioctl */ lomac_ioctl,
/* poll */ nopoll,
/* mmap */ nommap,
/* strategy */ nostrategy,
/* name */ "lomac",
/* maj */ CDEV_MAJOR,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ 0,
};
static dev_t lomac_dev = NULL;
int
lomac_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td) {
struct nameidata nd;
struct proc *p;
struct proc *targp;
struct lomac_fioctl *fio;
lomac_object_t lobj;
lattr_t lattr;
int error;
p = td->td_proc;
switch (cmd) {
case LIOGETPLEVEL:
targp = pfind(*(int *)data);
if (targp == NULL)
return (ESRCH);
if (p_cansee(p, targp) != 0) {
PROC_UNLOCK(targp);
return (ESRCH);
}
get_subject_lattr(targp, &lattr);
*(level_t *)data = lattr.level;
PROC_UNLOCK(targp);
return (0);
case LIOGETFLEVEL:
fio = (struct lomac_fioctl *)data;
NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | NOOBJ, UIO_SYSSPACE,
fio->path, td);
if ((error = namei(&nd)) != 0)
return (error);
if (VISLOMAC(nd.ni_vp))
lobj.lo_type = LO_TYPE_LVNODE;
else
lobj.lo_type = LO_TYPE_UVNODE;
lobj.lo_object.vnode = nd.ni_vp;
get_object_lattr(&lobj, &lattr);
*(level_t *)&fio->level = lattr.level;
NDFREE(&nd, NDF_ONLY_PNBUF);
vput(nd.ni_vp);
return (error);
case LIOGETFLATTR:
fio = (struct lomac_fioctl *)data;
NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | NOOBJ, UIO_SYSSPACE,
fio->path, td);
if ((error = namei(&nd)) != 0)
return (error);
if (VISLOMAC(nd.ni_vp))
lobj.lo_type = LO_TYPE_LVNODE;
else
lobj.lo_type = LO_TYPE_UVNODE;
lobj.lo_object.vnode = nd.ni_vp;
get_object_lattr(&lobj, (lattr_t *)&fio->level);
NDFREE(&nd, NDF_ONLY_PNBUF);
vput(nd.ni_vp);
return (error);
case LIOPMAKELOWLEVEL:
lattr.level = LOMAC_LOWEST_LEVEL;
lattr.flags = 0;
set_subject_lattr(p, lattr);
return (0);
default:
return (ENOTTY);
}
}
int (*old_execve)(struct proc *, void *);
#ifdef __i386__
int (*old_sysarch)(struct proc *, void *);
#endif
/*
* This is "borrowed" from kern_module.c and MUST be kept in synch!
*/
struct module {
TAILQ_ENTRY(module) link; /* chain together all modules */
TAILQ_ENTRY(module) flink; /* all modules in a file */
struct linker_file* file; /* file which contains this module */
int refs; /* reference count */
int id; /* unique id number */
char *name; /* module name */
modeventhand_t handler; /* event handler */
void *arg; /* argument for handler */
modspecific_t data; /* module specific data */
};
static int
lomac_modevent(module_t module, int event, void *unused) {
static int initialized_procs = 0;
static int initialized_syscalls = 0;
static int initialized_pipes = 0;
static int initialized_sockets = 0;
static int initialized_vm = 0;
static linker_file_t kernlf;
int error;
switch ((enum modeventtype)event) {
case MOD_LOAD:
if (!lomac_plm_initialized)
return (EINVAL);
kernlf = linker_kernel_file;
old_execve =
(int (*)(struct proc *, void *))linker_file_lookup_symbol(
kernlf, "execve", 1);
if (old_execve == NULL)
return (ENOENT);
#ifdef __i386__
old_sysarch =
(int (*)(struct proc *, void *))linker_file_lookup_symbol(
kernlf, "sysarch", 1);
if (old_sysarch == NULL)
return (ENOENT);
#endif
error = lomac_initialize_procs();
if (error)
break;
initialized_procs = 1;
error = lomac_initialize_syscalls();
if (error)
break;
initialized_syscalls = 1;
error = lomac_initialize_pipes();
if (error)
break;
initialized_pipes = 1;
error = lomac_initialize_sockets();
if (error)
break;
initialized_sockets = 1;
lomac_dev = make_dev(&lomac_cdevsw, LOMAC_MINOR, UID_ROOT,
GID_WHEEL, 0666, "lomac");
linker_kernel_file = module->file;
error = vfs_mount(curthread, "lomacfs", "/", 0, NULL);
if (error)
return (error);
error = lomac_initialize_cwds();
if (error)
return (error);
printf("LOMAC: Low-Watermark Mandatory Access Control v2.0.0\n");
return (error);
case MOD_UNLOAD:
/*
* It's always a bad idea to let a low-security process
* unload the module providing security.
*/
if (initialized_procs &&
!mediate_subject_at_level("kldunload", curthread->td_proc,
LOMAC_HIGHEST_LEVEL))
return (EPERM);
/*
* Unloading doesn't work well at the moment...
*/
return (EPERM);
if (initialized_sockets) {
error = lomac_uninitialize_sockets();
if (error)
break;
initialized_sockets = 0;
}
if (initialized_pipes) {
error = lomac_uninitialize_pipes();
if (error)
break;
initialized_pipes = 0;
}
if (initialized_syscalls) {
error = lomac_uninitialize_syscalls();
if (error)
break;
initialized_syscalls = 0;
}
if (initialized_procs) {
error = lomac_uninitialize_procs();
if (error)
break;
initialized_procs = 0;
}
if (initialized_vm) {
error = lomac_uninitialize_vm();
if (error)
break;
initialized_vm = 0;
}
if (lomac_dev) {
if (count_dev(lomac_dev) != 0)
return (EBUSY);
destroy_dev(lomac_dev);
}
printf("LOMAC: unloading\n");
linker_kernel_file = kernlf;
break;
case MOD_SHUTDOWN:
break;
}
return (0);
}
static moduledata_t lomac_moduledata = {
"lomac",
&lomac_modevent,
NULL
};
DECLARE_MODULE(lomac, lomac_moduledata, SI_SUB_VFS, SI_ORDER_ANY);
MODULE_VERSION(lomac, 1);
MODULE_DEPEND(lomac, syscall_gate, 1, 1, 1);
MODULE_DEPEND(lomac, lomacfs, 1, 1, 1);
MODULE_DEPEND(lomac, lomac_plm, 1, 1, 1);