libvirt/src/util/virtpm.c

/*
 * virtpm.c: TPM support
 *
 * Copyright (C) 2013 IBM Corporation
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Author: Stefan Berger <stefanb@linux.vnet.ibm.com>
 */

#include <config.h>

#include <sys/stat.h>

#include "virstring.h"
#include "virerror.h"
#include "viralloc.h"
#include "virfile.h"
#include "virtpm.h"

#define VIR_FROM_THIS VIR_FROM_NONE

/**
 * virTPMCreateCancelPath:
 * @devpath: Path to the TPM device
 *
 * Create the cancel path given the path to the TPM device
 */
char *
virTPMCreateCancelPath(const char *devpath)
{
    char *path = NULL;
    const char *dev;
    const char *prefix[] = {"misc/", "tpm/"};
    size_t i;

    if (devpath) {
        dev = strrchr(devpath, '/');
        if (dev) {
            dev++;
            for (i = 0; i < ARRAY_CARDINALITY(prefix); i++) {
                if (virAsprintf(&path, "/sys/class/%s%s/device/cancel",
                                prefix[i], dev) < 0)
                     goto cleanup;

                if (virFileExists(path))
                    break;

                VIR_FREE(path);
            }
            if (!path)
                virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                               _("No usable sysfs TPM cancel file could be "
                                 "found"));
        } else {
            virReportError(VIR_ERR_INTERNAL_ERROR,
                           _("TPM device path %s is invalid"), devpath);
        }
    } else {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Missing TPM device path"));
    }

 cleanup:
    return path;
}