NetBSD/sys/dev/verified_exec.c

426 lines
10 KiB
C

/* $NetBSD: verified_exec.c,v 1.47 2006/10/30 12:37:08 elad Exp $ */
/*-
* Copyright 2005 Elad Efrat <elad@NetBSD.org>
* Copyright 2005 Brett Lymn <blymn@netbsd.org>
*
* This code is derived from software contributed to The NetBSD Foundation
* by Brett Lymn and Elad Efrat
*
* 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. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
#if defined(__NetBSD__)
__KERNEL_RCSID(0, "$NetBSD: verified_exec.c,v 1.47 2006/10/30 12:37:08 elad Exp $");
#else
__RCSID("$Id: verified_exec.c,v 1.47 2006/10/30 12:37:08 elad Exp $\n$NetBSD: verified_exec.c,v 1.47 2006/10/30 12:37:08 elad Exp $");
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#ifdef __FreeBSD__
#include <sys/kernel.h>
#include <sys/device_port.h>
#include <sys/ioccom.h>
#else
#include <sys/ioctl.h>
#include <sys/device.h>
#define DEVPORT_DEVICE struct device
#endif
#include <sys/conf.h>
#include <sys/lock.h>
#include <sys/queue.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/namei.h>
#include <sys/sysctl.h>
#define VERIEXEC_NEED_NODE
#include <sys/verified_exec.h>
#include <sys/kauth.h>
#include <sys/fileassoc.h>
#include <sys/syslog.h>
/* count of number of times device is open (we really only allow one open) */
static unsigned int veriexec_dev_usage;
static unsigned int veriexec_tablecount = 0;
struct veriexec_softc {
DEVPORT_DEVICE veriexec_dev;
};
#if defined(__FreeBSD__)
# define CDEV_MAJOR 216
# define BDEV_MAJOR -1
#endif
const struct cdevsw veriexec_cdevsw = {
veriexecopen,
veriexecclose,
noread,
nowrite,
veriexecioctl,
#ifdef __NetBSD__
nostop,
notty,
#endif
nopoll,
nommap,
#if defined(__NetBSD__)
nokqfilter,
D_OTHER,
#elif defined(__FreeBSD__)
nostrategy,
"veriexec",
CDEV_MAJOR,
nodump,
nopsize,
0, /* flags */
BDEV_MAJOR
#endif
};
/* Autoconfiguration glue */
void veriexecattach(DEVPORT_DEVICE *parent, DEVPORT_DEVICE *self,
void *aux);
int veriexecopen(dev_t dev, int flags, int fmt, struct lwp *l);
int veriexecclose(dev_t dev, int flags, int fmt, struct lwp *l);
int veriexecioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
struct lwp *l);
void
veriexecattach(DEVPORT_DEVICE *parent __unused, DEVPORT_DEVICE *self __unused,
void *aux __unused)
{
veriexec_dev_usage = 0;
if (veriexec_verbose >= 2)
log(LOG_DEBUG, "Veriexec: Pseudo-device attached.\n");
}
int
veriexecopen(dev_t dev __unused, int flags __unused,
int fmt __unused, struct lwp *l __unused)
{
if (veriexec_verbose >= 2) {
log(LOG_DEBUG, "Veriexec: Pseudo-device open attempt by "
"uid=%u, pid=%u. (dev=%u)\n",
kauth_cred_geteuid(l->l_cred), l->l_proc->p_pid,
dev);
}
if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
&l->l_acflag) != 0)
return (EPERM);
if (veriexec_dev_usage > 0) {
if (veriexec_verbose >= 2)
log(LOG_ERR, "Veriexec: pseudo-device already in "
"use.\n");
return(EBUSY);
}
veriexec_dev_usage++;
return (0);
}
int
veriexecclose(dev_t dev __unused, int flags __unused, int fmt __unused,
struct lwp *l __unused)
{
if (veriexec_dev_usage > 0)
veriexec_dev_usage--;
return (0);
}
int
veriexecioctl(dev_t dev __unused, u_long cmd, caddr_t data, int flags __unused,
struct lwp *l)
{
int error = 0;
if (veriexec_strict > VERIEXEC_LEARNING) {
log(LOG_WARNING, "Veriexec: Strict mode, modifying tables not "
"permitted.\n");
return (EPERM);
}
switch (cmd) {
case VERIEXEC_TABLESIZE:
error = veriexec_newtable((struct veriexec_sizing_params *)
data, l);
break;
case VERIEXEC_LOAD:
error = veriexec_load((struct veriexec_params *)data, l);
break;
case VERIEXEC_DELETE:
error = veriexec_delete((struct veriexec_delete_params *)data,
l);
break;
case VERIEXEC_QUERY:
error = veriexec_query((struct veriexec_query_params *)data, l);
break;
default:
/* Invalid operation. */
error = ENODEV;
break;
}
return (error);
}
#if defined(__FreeBSD__)
static void
veriexec_drvinit(void *unused __unused)
{
make_dev(&verifiedexec_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
"veriexec");
verifiedexecattach(0, 0, 0);
}
SYSINIT(veriexec, SI_SUB_PSEUDO, SI_ORDER_ANY, veriexec_drvinit, NULL);
#endif
/*
* Create a new Veriexec table.
*/
int
veriexec_newtable(struct veriexec_sizing_params *params, struct lwp *l)
{
struct veriexec_table_entry *vte;
struct nameidata nid;
u_char buf[16];
int error;
NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, l);
error = namei(&nid);
if (error)
return (error);
error = fileassoc_table_add(nid.ni_vp->v_mount, params->hash_size);
if (error && (error != EEXIST))
goto out;
vte = malloc(sizeof(*vte), M_TEMP, M_WAITOK | M_ZERO);
error = fileassoc_tabledata_add(nid.ni_vp->v_mount, veriexec_hook, vte);
#ifdef DIAGNOSTIC
if (error)
panic("Fileassoc: Inconsistency after adding table");
#endif /* DIAGNOSTIC */
snprintf(buf, sizeof(buf), "table%u", veriexec_tablecount++);
sysctl_createv(NULL, 0, &veriexec_count_node, &vte->vte_node,
0, CTLTYPE_NODE, buf, NULL, NULL, 0, NULL,
0, CTL_CREATE, CTL_EOL);
sysctl_createv(NULL, 0, &vte->vte_node, NULL,
CTLFLAG_READONLY, CTLTYPE_STRING, "mntpt",
NULL, NULL, 0, nid.ni_vp->v_mount->mnt_stat.f_mntonname,
0, CTL_CREATE, CTL_EOL);
sysctl_createv(NULL, 0, &vte->vte_node, NULL,
CTLFLAG_READONLY, CTLTYPE_STRING, "fstype",
NULL, NULL, 0, nid.ni_vp->v_mount->mnt_stat.f_fstypename,
0, CTL_CREATE, CTL_EOL);
sysctl_createv(NULL, 0, &vte->vte_node, NULL,
CTLFLAG_READONLY, CTLTYPE_QUAD, "nentries",
NULL, NULL, 0, &vte->vte_count, 0, CTL_CREATE, CTL_EOL);
out:
vrele(nid.ni_vp);
return (error);
}
int
veriexec_load(struct veriexec_params *params, struct lwp *l)
{
struct veriexec_file_entry *hh, *e;
struct nameidata nid;
int error;
NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, l);
error = namei(&nid);
if (error)
return (error);
/* Add only regular files. */
if (nid.ni_vp->v_type != VREG) {
log(LOG_ERR, "Veriexec: Not adding `%s': Not a regular file.\n",
params->file);
error = EINVAL;
goto out;
}
e = malloc(sizeof(*e), M_TEMP, M_WAITOK);
if ((e->ops = veriexec_find_ops(params->fp_type)) == NULL) {
free(e, M_TEMP);
log(LOG_ERR, "Veriexec: Invalid or unknown fingerprint type "
"`%s' for file `%s'.\n", params->fp_type, params->file);
error = EINVAL;
goto out;
}
e->fp = malloc(e->ops->hash_len, M_TEMP, M_WAITOK|M_ZERO);
error = copyin(params->fingerprint, e->fp, e->ops->hash_len);
if (error) {
free(e->fp, M_TEMP);
free(e, M_TEMP);
goto out;
}
hh = veriexec_lookup(nid.ni_vp);
if (hh != NULL) {
boolean_t fp_mismatch;
if (strcmp(e->ops->type, params->fp_type) ||
memcmp(hh->fp, e->fp, hh->ops->hash_len))
fp_mismatch = TRUE;
else
fp_mismatch = FALSE;
if ((veriexec_verbose >= 1) || fp_mismatch)
log(LOG_NOTICE, "Veriexec: Duplicate entry for `%s' "
"ignored. (%s fingerprint)\n", params->file,
fp_mismatch ? "different" : "same");
free(e->fp, M_TEMP);
free(e, M_TEMP);
error = 0;
goto out;
}
e->type = params->type;
e->status = FINGERPRINT_NOTEVAL;
e->page_fp = NULL;
e->page_fp_status = PAGE_FP_NONE;
e->npages = 0;
e->last_page_size = 0;
error = veriexec_hashadd(nid.ni_vp, e);
if (error) {
free(e->fp, M_TEMP);
free(e, M_TEMP);
goto out;
}
veriexec_report("New entry.", params->file, NULL, REPORT_DEBUG);
out:
vrele(nid.ni_vp);
return (error);
}
int
veriexec_delete(struct veriexec_delete_params *params, struct lwp *l)
{
struct veriexec_table_entry *vte;
struct nameidata nid;
int error;
NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, l);
error = namei(&nid);
if (error)
return (error);
vte = veriexec_tblfind(nid.ni_vp);
if (vte == NULL) {
error = ENOENT;
goto out;
}
/* XXX this should either receive the filename to remove OR a mount point! */
/* Delete an entire table */
if (nid.ni_vp->v_type == VDIR) {
sysctl_free(__UNCONST(vte->vte_node));
veriexec_tablecount--;
error = fileassoc_table_clear(nid.ni_vp->v_mount, veriexec_hook);
if (error)
goto out;
} else if (nid.ni_vp->v_type == VREG) {
error = fileassoc_clear(nid.ni_vp, veriexec_hook);
if (error)
goto out;
vte->vte_count--;
}
out:
vrele(nid.ni_vp);
return (error);
}
int
veriexec_query(struct veriexec_query_params *params, struct lwp *l)
{
struct veriexec_file_entry *vfe;
struct nameidata nid;
int error;
NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, l);
error = namei(&nid);
if (error)
return (error);
vfe = veriexec_lookup(nid.ni_vp);
if (vfe == NULL) {
error = ENOENT;
goto out;
}
params->type = vfe->type;
params->status = vfe->status;
params->hash_len = vfe->ops->hash_len;
strlcpy(params->fp_type, vfe->ops->type, sizeof(params->fp_type));
memcpy(params->fp_type, vfe->ops->type, sizeof(params->fp_type));
error = copyout(params, params->uaddr, sizeof(*params));
if (error)
goto out;
if (params->fp_bufsize >= vfe->ops->hash_len) {
error = copyout(vfe->fp, params->fp, vfe->ops->hash_len);
if (error)
goto out;
} else
error = ENOMEM;
out:
vrele(nid.ni_vp);
return (error);
}