[libvirt] [PATCH 13/18] tpm: Parse the capabilities supported by swtpm and swtpm_setup
Stefan Berger
stefanb at linux.ibm.com
Wed Jul 10 11:48:14 UTC 2019
On 7/9/19 4:24 PM, Marc-André Lureau wrote:
> On Tue, Jul 9, 2019 at 9:24 PM Stefan Berger <stefanb at linux.vnet.ibm.com> wrote:
>> Run 'swtpm socket --print-capabilities' and
>> 'swtpm_setup --print-capabilities' to get the JSON object of the
>> features the programs are supporting and parse them into a bitmap.
>>
>> Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
>> ---
>> src/conf/Makefile.inc.am | 6 ++
>> src/conf/virtpm_conf.c | 36 ++++++++++++
>> src/conf/virtpm_conf.h | 36 ++++++++++++
>> src/libvirt_private.syms | 5 ++
>> src/tpm/Makefile.inc.am | 5 +-
>> src/tpm/virtpm.c | 123 ++++++++++++++++++++++++++++++++++++++-
>> 6 files changed, 209 insertions(+), 2 deletions(-)
>> create mode 100644 src/conf/virtpm_conf.c
>> create mode 100644 src/conf/virtpm_conf.h
>>
>> diff --git a/src/conf/Makefile.inc.am b/src/conf/Makefile.inc.am
>> index 08c7c9da7f..e42425fcc5 100644
>> --- a/src/conf/Makefile.inc.am
>> +++ b/src/conf/Makefile.inc.am
>> @@ -153,6 +153,11 @@ DEVICE_CONF_SOURCES = \
>> conf/device_conf.h \
>> $(NULL)
>>
>> +TPM_CONF_SOURCES = \
>> + conf/virtpm_conf.c \
>> + conf/virtpm_conf.h \
>> + $(NULL)
>> +
>> CONF_SOURCES = \
>> $(NETDEV_CONF_SOURCES) \
>> $(DOMAIN_CONF_SOURCES) \
>> @@ -171,6 +176,7 @@ CONF_SOURCES = \
>> $(CPU_CONF_SOURCES) \
>> $(CHRDEV_CONF_SOURCES) \
>> $(DEVICE_CONF_SOURCES) \
>> + $(TPM_CONF_SOURCES) \
>> $(NULL)
>>
>> noinst_LTLIBRARIES += libvirt_conf.la
>> diff --git a/src/conf/virtpm_conf.c b/src/conf/virtpm_conf.c
>> new file mode 100644
>> index 0000000000..12e69e67b3
>> --- /dev/null
>> +++ b/src/conf/virtpm_conf.c
>> @@ -0,0 +1,36 @@
>> +/*
>> + * virtpm_conf.c: vTPM XML processing
>> + *
>> + * Copyright (C) 2019 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/>.
>> + */
>> +
>> +#include <config.h>
>> +
>> +#include "virenum.h"
>> +#include "virtpm_conf.h"
>> +
>> +#define VIR_FROM_THIS VIR_FROM_NONE
>> +
>> +VIR_ENUM_IMPL(virTPMSwtpmFeature,
>> + VIR_TPM_SWTPM_FEATURE_LAST,
>> + "cmdarg-pwd-fd",
>> +);
>> +
>> +VIR_ENUM_IMPL(virTPMSwtpmSetupFeature,
>> + VIR_TPM_SWTPM_SETUP_FEATURE_LAST,
>> + "cmdarg-pwdfile-fd",
>> +);
>> diff --git a/src/conf/virtpm_conf.h b/src/conf/virtpm_conf.h
>> new file mode 100644
>> index 0000000000..73c6c67271
>> --- /dev/null
>> +++ b/src/conf/virtpm_conf.h
>> @@ -0,0 +1,36 @@
>> +/*
>> + * virtpm_conf.h: vTPM XML processing
>> + *
>> + * Copyright (C) 2019 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/>.
>> + */
>> +
>> +#pragma once
>> +
>> +typedef enum {
>> + VIR_TPM_SWTPM_FEATURE_CMDARG_PWD_FD,
>> +
>> + VIR_TPM_SWTPM_FEATURE_LAST
>> +} virTPMSwtpmFeature;
>> +
>> +typedef enum {
>> + VIR_TPM_SWTPM_SETUP_FEATURE_CMDARG_PWDFILE_FD,
>> +
>> + VIR_TPM_SWTPM_SETUP_FEATURE_LAST
>> +} virTPMSwtpmSetupFeature;
>> +
>> +VIR_ENUM_DECL(virTPMSwtpmFeature);
>> +VIR_ENUM_DECL(virTPMSwtpmSetupFeature);
>> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
>> index e33d7d9f14..d2045895a1 100644
>> --- a/src/libvirt_private.syms
>> +++ b/src/libvirt_private.syms
>> @@ -1236,6 +1236,11 @@ virStoragePoolObjVolumeGetNames;
>> virStoragePoolObjVolumeListExport;
>>
>>
>> +# conf/virtpm_conf.h
>> +virTPMSwtpmFeatureTypeFromString;
>> +virTPMSwtpmSetupFeatureTypeFromString;
>> +
>> +
>> # cpu/cpu.h
>> cpuDecode;
>> cpuEncode;
>> diff --git a/src/tpm/Makefile.inc.am b/src/tpm/Makefile.inc.am
>> index 1f5131bf34..d8a15c406c 100644
>> --- a/src/tpm/Makefile.inc.am
>> +++ b/src/tpm/Makefile.inc.am
>> @@ -12,6 +12,9 @@ EXTRA_DIST += \
>>
>> noinst_LTLIBRARIES += libvirt_tpm.la
>> libvirt_la_BUILT_LIBADD += libvirt_tpm.la
>> -libvirt_tpm_la_CFLAGS = $(AM_CFLAGS)
>> +libvirt_tpm_la_CFLAGS = \
>> + -I$(srcdir)/conf \
>> + $(AM_CFLAGS) \
>> + $(NULL)
>> libvirt_tpm_la_LDFLAGS = $(AM_LDFLAGS)
>> libvirt_tpm_la_SOURCES = $(TPM_UTIL_SOURCES)
>> diff --git a/src/tpm/virtpm.c b/src/tpm/virtpm.c
>> index e4735f9c4d..42dd2b1bb2 100644
>> --- a/src/tpm/virtpm.c
>> +++ b/src/tpm/virtpm.c
>> @@ -27,6 +27,10 @@
>> #include "viralloc.h"
>> #include "virfile.h"
>> #include "virtpm.h"
>> +#include "vircommand.h"
>> +#include "virbitmap.h"
>> +#include "virjson.h"
>> +#include "virtpm_conf.h"
>>
>> #define VIR_FROM_THIS VIR_FROM_NONE
>>
>> @@ -74,17 +78,22 @@ virTPMCreateCancelPath(const char *devpath)
>> }
>>
>> /*
>> - * executables for the swtpm; to be found on the host
>> + * executables for the swtpm; to be found on the host along with
>> + * capabilties bitmap
>> */
>> static char *swtpm_path;
>> static struct stat swtpm_stat;
>> +static virBitmapPtr swtpm_caps;
>>
>> static char *swtpm_setup;
>> static struct stat swtpm_setup_stat;
>> +static virBitmapPtr swtpm_setup_caps;
>>
>> static char *swtpm_ioctl;
>> static struct stat swtpm_ioctl_stat;
>>
>> +typedef int (*TypeFromStringFn)(const char *);
>> +
>> const char *
>> virTPMGetSwtpm(void)
>> {
>> @@ -109,6 +118,106 @@ virTPMGetSwtpmIoctl(void)
>> return swtpm_ioctl;
>> }
>>
>> +/* virTPMExecGetCaps
>> + *
>> + * Execute the prepared command and parse the returned JSON object
>> + * to get the capabilities supported by the executable.
>> + * A JSON object like this is expected:
>> + *
>> + * {
>> + * "type": "swtpm",
>> + * "features": [
>> + * "cmdarg-seccomp",
>> + * "cmdarg-key-fd",
>> + * "cmdarg-pwd-fd"
>> + * ]
>> + * }
>> + */
>> +static virBitmapPtr
>> +virTPMExecGetCaps(virCommandPtr cmd,
>> + TypeFromStringFn typeFromStringFn)
>> +{
>> + int exitstatus;
>> + virBitmapPtr bitmap;
>> + char *outbuf = NULL;
>> + virJSONValuePtr json = NULL;
>> + virJSONValuePtr featureList;
>> + virJSONValuePtr item;
>> + size_t idx;
>> + const char *str;
>> + int typ;
>> +
>> + if (!(bitmap = virBitmapNewEmpty()))
>> + return NULL;
>> +
>> + virCommandSetOutputBuffer(cmd, &outbuf);
>> + /* We allow the command to fail since older versions of it may
>> + * not support --print-capabilities
>> + */
>> + if (virCommandRun(cmd, &exitstatus) < 0 || exitstatus != 0)
>> + goto cleanup;
> We should probably fail if the command failed to run, and skip if
> exitstatus != 0.
>
>> +
>> + json = virJSONValueFromString(outbuf);
>> + if (!json)
>> + goto error_bad_json;
>> +
>> + featureList = virJSONValueObjectGetArray(json, "features");
>> + if (!featureList)
>> + goto error_bad_json;
>> +
>> + if (!virJSONValueIsArray(featureList))
>> + goto error_bad_json;
>> +
>> + for (idx = 0; idx < virJSONValueArraySize(featureList); idx++) {
>> + item = virJSONValueArrayGet(featureList, idx);
>> + if (!item)
>> + continue;
>> +
>> + str = virJSONValueGetString(item);
>> + if (!str)
>> + goto error_bad_json;
>> + typ = typeFromStringFn(str);
>> + if (typ < 0)
>> + continue;
>> +
>> + if (virBitmapSetBitExpand(bitmap, typ) < 0)
>> + goto cleanup;
>> + }
>> +
>> + cleanup:
>> + VIR_FREE(outbuf);
>> + virJSONValueFree(json);
> Please use VIR_AUTOFREE and VIR_AUTOPTR
The new stuff. Forgot about it... Will fix.
>
>> +
>> + return bitmap;
>> +
>> + error_bad_json:
>> + virReportError(VIR_ERR_INTERNAL_ERROR,
>> + _("Unexpected JSON format: %s"), outbuf);
>> + goto cleanup;
>> +}
>> +
>> +static virBitmapPtr
>> +virTPMGetCaps(TypeFromStringFn typeFromStringFn,
>> + const char *exec, const char *param1)
>> +{
>> + virCommandPtr cmd;
>> + virBitmapPtr bitmap;
>> +
>> + cmd = virCommandNew(exec);
>> + if (!cmd)
>> + return NULL;
>> + if (param1)
>> + virCommandAddArg(cmd, param1);
> Hmm, I would expect --print-capabilites to be top-level argument, not
> a sub-command argument.
'swtpm' has 'swtpm socket' and 'swtpm cuse' and advertises different
capabilities for 'swtpm socket --print-capabilities' than for 'swtpm
cuse --print-capabilities'. It doesn't support 'swtpm --print-capabilities'.
Thanks,
Stefan
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