Re: [libvirt] [PATCH v3 04/11] Helper functions for host TPM support

Signed-off-by: Stefan Berger&lt;stefanb(a)linux.vnet.ibm.com&gt; --- po/POTFILES.in | 1 src/Makefile.am | 1 src/libvirt_private.syms | 4 + src/util/virtpm.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++ src/util/virtpm.h | 27 ++++++++++ 5 files changed, 157 insertions(+) Index: libvirt/src/Makefile.am =================================================================== --- libvirt.orig/src/Makefile.am +++ libvirt/src/Makefile.am @@ -122,6 +122,7 @@ UTIL_SOURCES = \ util/virthreadwin32.h \ util/virthreadpool.c util/virthreadpool.h \ util/virtime.h util/virtime.c \ + util/virtpm.h util/virtpm.c \ util/virtypedparam.c util/virtypedparam.h \ util/virusb.c util/virusb.h \ util/viruri.h util/viruri.c \ Index: libvirt/src/util/virtpm.c =================================================================== --- /dev/null +++ libvirt/src/util/virtpm.c @@ -0,0 +1,124 @@ +/* + * 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&lt;stefanb(a)linux.vnet.ibm.com&gt; + */ + +#include <config.h> + +#include <stdio.h> +#include <dirent.h> +#include <unistd.h> +#include <sys/stat.h> + +#include "virobject.h" +#include "viralloc.h" +#include "virutil.h" +#include "virerror.h" +#include "virbuffer.h" +#include "virtpm.h" + +#define VIR_FROM_THIS VIR_FROM_NONE + +/* + * Check whether the given base path, e.g., /sys/class/misc/tpm0/device, + * is the sysfs entry of a TPM. A TPM sysfs entry should be uniquely + * recognizable by the file entries 'pcrs' and 'cancel'. + * Upon success 'true' is returned and the basebath buffer has '/cancel'

+ * appended. + */ +static bool +virTPMCheckSysfsCancel(char *basepath, size_t bufsz) +{ + char *path = NULL; + struct stat statbuf; + + if (virAsprintf(&path, "%s/pcrs", basepath) < 0) { + virReportOOMError(); + goto error; + } + if (stat(path, &statbuf) == -1 || !S_ISREG(statbuf.st_mode)) + goto error; + + VIR_FREE(path); + + if (virAsprintf(&path, "%s/cancel", basepath) < 0) { + virReportOOMError(); + goto error; + } + + if (stat(path, &statbuf) == -1 || !S_ISREG(statbuf.st_mode)) + goto error; + + if (!virStrncpy(basepath, path, strlen(path) + 1, bufsz)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Basepath buffer is too small")); + goto error; + } + + VIR_FREE(path); + + return true; + +error: + VIR_FREE(path); + return false; +} + + +char * +virTPMFindCancelPath(void) +{ + unsigned int idx; + int len; + DIR *pnp_dir; + char path[100], *p;

+ struct dirent entry, *result; + bool found = false; + + snprintf(path, sizeof(path), "/sys/class/misc"); + pnp_dir = opendir(path); + if (pnp_dir != NULL) { + while (readdir_r(pnp_dir, &entry, &result) == 0 && + result != NULL) { + if (sscanf(entry.d_name, "tpm%u%n", &idx, &len) < 1 || + len <= strlen("tpm") || + len != strlen(entry.d_name)) { + continue; + } + snprintf(path, sizeof(path), "/sys/class/misc/%s/device", + entry.d_name); + if (!virTPMCheckSysfsCancel(path, sizeof(path))) { + continue; + } + + found = true; + break; + } + closedir(pnp_dir); + } + + if (found) { + if (!(p = strdup(path))) + virReportOOMError(); + return p; + } + + return NULL; +} Index: libvirt/src/libvirt_private.syms =================================================================== --- libvirt.orig/src/libvirt_private.syms +++ libvirt/src/libvirt_private.syms @@ -1772,6 +1772,10 @@ virTimeStringThen; virTimeStringThenRaw; +# util/virtpm.h +virTPMFindCancelPath; + + # util/virtypedparam.h virTypedParameterArrayValidate; virTypedParameterAssign; Index: libvirt/src/util/virtpm.h =================================================================== --- /dev/null +++ libvirt/src/util/virtpm.h @@ -0,0 +1,27 @@ +/* + * virtpm.h: 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&lt;stefanb(a)linux.vnet.ibm.com&gt; + */ +#ifndef __VIR_TPM_H__ +# define __VIR_TPM_H__ + +char *virTPMFindCancelPath(void); + +#endif /* __VIR_TPM_H__ */ Index: libvirt/po/POTFILES.in =================================================================== --- libvirt.orig/po/POTFILES.in +++ libvirt/po/POTFILES.in @@ -181,6 +181,7 @@ src/util/virsysinfo.c src/util/virerror.c src/util/virerror.h src/util/virtime.c +src/util/virtpm.c src/util/virtypedparam.c src/util/viruri.c src/util/virusb.c