436 lines
11 KiB
C
436 lines
11 KiB
C
/* $NetBSD: verified_exec.c,v 1.33 2006/05/14 21:42:26 elad Exp $ */
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/*-
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* Copyright 2005 Elad Efrat <elad@bsd.org.il>
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* Copyright 2005 Brett Lymn <blymn@netbsd.org>
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Brett Lymn and Elad Efrat
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#if defined(__NetBSD__)
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__KERNEL_RCSID(0, "$NetBSD: verified_exec.c,v 1.33 2006/05/14 21:42:26 elad Exp $");
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#else
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__RCSID("$Id: verified_exec.c,v 1.33 2006/05/14 21:42:26 elad Exp $\n$NetBSD: verified_exec.c,v 1.33 2006/05/14 21:42:26 elad Exp $");
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#endif
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/errno.h>
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#include <sys/buf.h>
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#include <sys/malloc.h>
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#ifdef __FreeBSD__
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#include <sys/kernel.h>
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#include <sys/device_port.h>
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#include <sys/ioccom.h>
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#else
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#include <sys/ioctl.h>
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#include <sys/device.h>
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#define DEVPORT_DEVICE struct device
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#endif
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#include <sys/conf.h>
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#include <sys/lock.h>
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#include <sys/queue.h>
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#include <sys/vnode.h>
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#include <sys/fcntl.h>
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#include <sys/namei.h>
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#include <sys/sysctl.h>
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#define VERIEXEC_NEED_NODE
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#include <sys/verified_exec.h>
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/* count of number of times device is open (we really only allow one open) */
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static unsigned int veriexec_dev_usage;
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struct veriexec_softc {
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DEVPORT_DEVICE veriexec_dev;
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};
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#if defined(__FreeBSD__)
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# define CDEV_MAJOR 216
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# define BDEV_MAJOR -1
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#endif
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const struct cdevsw veriexec_cdevsw = {
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veriexecopen,
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veriexecclose,
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noread,
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nowrite,
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veriexecioctl,
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#ifdef __NetBSD__
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nostop,
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notty,
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#endif
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nopoll,
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nommap,
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#if defined(__NetBSD__)
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nokqfilter,
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#elif defined(__FreeBSD__)
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nostrategy,
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"veriexec",
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CDEV_MAJOR,
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nodump,
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nopsize,
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0, /* flags */
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BDEV_MAJOR
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#endif
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};
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/* Autoconfiguration glue */
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void veriexecattach(DEVPORT_DEVICE *parent, DEVPORT_DEVICE *self,
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void *aux);
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int veriexecopen(dev_t dev, int flags, int fmt, struct lwp *l);
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int veriexecclose(dev_t dev, int flags, int fmt, struct lwp *l);
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int veriexecioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
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struct lwp *l);
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void
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veriexecattach(DEVPORT_DEVICE *parent, DEVPORT_DEVICE *self,
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void *aux)
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{
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veriexec_dev_usage = 0;
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if (veriexec_verbose >= 2)
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printf("Veriexec: veriexecattach: Veriexec pseudo-device"
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"attached.\n");
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}
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int
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veriexecopen(dev_t dev __unused, int flags __unused,
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int fmt __unused, struct lwp *l __unused)
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{
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if (veriexec_verbose >= 2) {
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printf("Veriexec: veriexecopen: Veriexec load device "
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"open attempt by uid=%u, pid=%u. (dev=%u)\n",
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kauth_cred_geteuid(l->l_proc->p_cred),
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l->l_proc->p_pid, dev);
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}
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if (kauth_authorize_generic(l->l_proc->p_cred, KAUTH_GENERIC_ISSUSER,
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&l->l_proc->p_acflag) != 0)
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return (EPERM);
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if (veriexec_dev_usage > 0) {
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if (veriexec_verbose >= 2)
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printf("Veriexec: load device already in use.\n");
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return(EBUSY);
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}
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veriexec_dev_usage++;
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return (0);
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}
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int
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veriexecclose(dev_t dev __unused, int flags __unused,
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int fmt __unused, struct lwp *l __unused)
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{
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if (veriexec_dev_usage > 0)
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veriexec_dev_usage--;
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return (0);
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}
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int
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veriexecioctl(dev_t dev __unused, u_long cmd, caddr_t data,
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int flags __unused, struct lwp *l)
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{
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int error = 0;
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if (veriexec_strict > 0) {
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printf("Veriexec: veriexecioctl: Strict mode, modifying "
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"veriexec tables is not permitted.\n");
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return (EPERM);
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}
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switch (cmd) {
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case VERIEXEC_TABLESIZE:
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error = veriexec_newtable((struct veriexec_sizing_params *)
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data);
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break;
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case VERIEXEC_LOAD:
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error = veriexec_load((struct veriexec_params *)data, l);
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break;
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case VERIEXEC_DELETE:
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error = veriexec_delete((struct veriexec_delete_params *)data);
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break;
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case VERIEXEC_QUERY:
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error = veriexec_query((struct veriexec_query_params *)data);
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break;
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default:
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/* Invalid operation. */
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error = ENODEV;
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break;
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}
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return (error);
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}
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#if defined(__FreeBSD__)
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static void
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veriexec_drvinit(void *unused __unused)
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{
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make_dev(&verifiedexec_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
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"veriexec");
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verifiedexecattach(0, 0, 0);
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}
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SYSINIT(veriexec, SI_SUB_PSEUDO, SI_ORDER_ANY, veriexec_drvinit, NULL);
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#endif
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int
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veriexec_newtable(struct veriexec_sizing_params *params)
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{
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struct veriexec_hashtbl *tbl;
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u_char node_name[16];
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u_long hashmask;
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/* Check for existing table for device. */
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if (veriexec_tblfind(params->dev) != NULL)
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return (EEXIST);
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/* Allocate and initialize a Veriexec hash table. */
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tbl = malloc(sizeof(*tbl), M_TEMP, M_WAITOK);
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tbl->hash_size = params->hash_size;
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tbl->hash_dev = params->dev;
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tbl->hash_tbl = hashinit(params->hash_size, HASH_LIST, M_TEMP,
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M_WAITOK, &hashmask);
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tbl->hash_count = 0;
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LIST_INSERT_HEAD(&veriexec_tables, tbl, hash_list);
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snprintf(node_name, sizeof(node_name), "dev_%u",
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tbl->hash_dev);
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sysctl_createv(NULL, 0, &veriexec_count_node, NULL,
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CTLFLAG_READONLY, CTLTYPE_QUAD, node_name,
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NULL, NULL, 0, &tbl->hash_count, 0,
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tbl->hash_dev, CTL_EOL);
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return (0);
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}
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int
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veriexec_load(struct veriexec_params *params, struct lwp *l)
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{
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struct veriexec_hashtbl *tbl;
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struct veriexec_hash_entry *hh;
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struct veriexec_hash_entry *e;
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struct nameidata nid;
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struct vattr va;
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int error;
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NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE, params->file, l);
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error = namei(&nid);
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if (error)
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return (error);
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/* Add only regular files. */
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if (nid.ni_vp->v_type != VREG) {
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printf("Veriexec: veriexecioctl: Not adding \"%s\": "
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"Not a regular file.\n", params->file);
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vrele(nid.ni_vp);
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return (EINVAL);
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}
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/* Get attributes for device and inode. */
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error = VOP_GETATTR(nid.ni_vp, &va, l->l_proc->p_cred, l);
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if (error) {
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vrele(nid.ni_vp);
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return (error);
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}
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/* Release our reference to the vnode. (namei) */
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vrele(nid.ni_vp);
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/* Get table for the device. */
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tbl = veriexec_tblfind(va.va_fsid);
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if (tbl == NULL) {
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return (EINVAL);
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}
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hh = veriexec_lookup(va.va_fsid, va.va_fileid);
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if (hh != NULL) {
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/*
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* Duplicate entry means something is wrong in
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* the signature file. Just give collision info
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* and return.
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*/
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printf("veriexec: Duplicate entry. [%s, %ld:%llu] "
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"old[type=0x%02x, algorithm=%s], "
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"new[type=0x%02x, algorithm=%s] "
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"(%s fingerprint)\n",
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params->file, va.va_fsid,
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(unsigned long long)va.va_fileid,
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hh->type, hh->ops->type,
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params->type, params->fp_type,
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(((hh->ops->hash_len != params->size) ||
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(memcmp(hh->fp, params->fingerprint,
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min(hh->ops->hash_len, params->size))
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!= 0)) ? "different" : "same"));
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return (0);
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}
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e = malloc(sizeof(*e), M_TEMP, M_WAITOK);
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e->inode = va.va_fileid;
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e->type = params->type;
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e->status = FINGERPRINT_NOTEVAL;
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e->page_fp = NULL;
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e->page_fp_status = PAGE_FP_NONE;
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e->npages = 0;
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e->last_page_size = 0;
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if ((e->ops = veriexec_find_ops(params->fp_type)) == NULL) {
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free(e, M_TEMP);
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printf("Veriexec: veriexecioctl: Invalid or unknown "
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"fingerprint type \"%s\" for file \"%s\" "
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"(dev=%ld, inode=%llu)\n", params->fp_type,
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params->file, va.va_fsid,
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(unsigned long long)va.va_fileid);
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return(EINVAL);
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}
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/*
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* Just a bit of a sanity check - require the size of
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* the fp to be passed in, check this against the expected
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* size. Of course userland could lie deliberately, this
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* really only protects against the obvious fumble of
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* changing the fp type but not updating the fingerprint
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* string.
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*/
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if (e->ops->hash_len != params->size) {
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printf("Veriexec: veriexecioctl: Inconsistent "
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"fingerprint size for type \"%s\" for file "
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"\"%s\" (dev=%ld, inode=%llu), size was %u "
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"was expecting %zu\n", params->fp_type,
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params->file, va.va_fsid,
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(unsigned long long)va.va_fileid,
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params->size, e->ops->hash_len);
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free(e, M_TEMP);
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return(EINVAL);
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}
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e->fp = malloc(e->ops->hash_len, M_TEMP, M_WAITOK);
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memcpy(e->fp, params->fingerprint, e->ops->hash_len);
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veriexec_report("New entry.", params->file, &va, NULL,
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REPORT_VERBOSE_HIGH, REPORT_NOALARM,
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REPORT_NOPANIC);
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error = veriexec_hashadd(tbl, e);
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return (error);
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}
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int
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veriexec_delete(struct veriexec_delete_params *params)
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{
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struct veriexec_hashtbl *tbl;
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struct veriexec_hash_entry *vhe;
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/* Delete an entire table */
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if (params->ino == 0) {
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struct veriexec_hashhead *tbl_list;
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u_long i;
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tbl = veriexec_tblfind(params->dev);
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if (tbl == NULL)
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return (ENOENT);
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/* Remove all entries from the table and lists */
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tbl_list = tbl->hash_tbl;
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for (i = 0; i < tbl->hash_size; i++) {
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while (LIST_FIRST(&tbl_list[i]) != NULL) {
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vhe = LIST_FIRST(&tbl_list[i]);
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if (vhe->fp != NULL)
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free(vhe->fp, M_TEMP);
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if (vhe->page_fp != NULL)
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free(vhe->page_fp, M_TEMP);
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LIST_REMOVE(vhe, entries);
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free(vhe, M_TEMP);
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}
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}
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/* Remove hash table and sysctl node */
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hashdone(tbl->hash_tbl, M_TEMP);
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LIST_REMOVE(tbl, hash_list);
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sysctl_destroyv(__UNCONST(veriexec_count_node), params->dev,
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CTL_EOL);
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} else {
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tbl = veriexec_tblfind(params->dev);
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if (tbl == NULL)
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return (ENOENT);
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vhe = veriexec_lookup(params->dev, params->ino);
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if (vhe != NULL) {
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if (vhe->fp != NULL)
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free(vhe->fp, M_TEMP);
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if (vhe->page_fp != NULL)
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free(vhe->page_fp, M_TEMP);
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LIST_REMOVE(vhe, entries);
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free(vhe, M_TEMP);
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tbl->hash_count--;
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}
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}
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return (0);
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}
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int
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veriexec_query(struct veriexec_query_params *params)
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{
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struct veriexec_hash_entry *vhe;
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int error;
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vhe = veriexec_lookup(params->dev, params->ino);
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if (vhe == NULL)
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return (ENOENT);
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params->type = vhe->type;
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params->status = vhe->status;
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params->hash_len = vhe->ops->hash_len;
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strlcpy(params->fp_type, vhe->ops->type, sizeof(params->fp_type));
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memcpy(params->fp_type, vhe->ops->type, sizeof(params->fp_type));
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error = copyout(params, params->uaddr, sizeof(*params));
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if (error)
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return (error);
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if (params->fp_bufsize >= vhe->ops->hash_len) {
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error = copyout(vhe->fp, params->fp, vhe->ops->hash_len);
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if (error)
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return (error);
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} else
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error = ENOMEM;
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return (error);
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}
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