12:47 p.m.
On 05/08/2018 04:30 PM, John Ferlan wrote:
On 05/04/2018 04:21 PM, Stefan Berger wrote:
> Add functions for managing the storage of the external swtpm as well
> as starting and stopping it. Also implement functions to use swtpm_setup,
> which simulates the manufacturing of a TPM which includes creation of
> certificates for the device.
>
> Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com>
> ---
> src/libvirt_private.syms | 5 +
> src/util/virtpm.c | 536 ++++++++++++++++++++++++++++++++++++++++++++++-
> src/util/virtpm.h | 33 ++-
> 3 files changed, 572 insertions(+), 2 deletions(-)
>> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 33fe75b..eebfc72 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2984,6 +2984,11 @@ virTimeStringThenRaw;
>
> # util/virtpm.h
> virTPMCreateCancelPath;
> +virTPMDeleteEmulatorStorage;
> +virTPMEmulatorBuildCommand;
> +virTPMEmulatorInitPaths;
> +virTPMEmulatorPrepareHost;
> +virTPMEmulatorStop;
>
>
> # util/virtypedparam.h
> diff --git a/src/util/virtpm.c b/src/util/virtpm.c
> index d5c10da..76bbb21 100644
> --- a/src/util/virtpm.c
> +++ b/src/util/virtpm.c
> @@ -1,7 +1,7 @@
> /*
> * virtpm.c: TPM support
> *
> - * Copyright (C) 2013 IBM Corporation
> + * Copyright (C) 2013,2018 IBM Corporation
> *
> * This library is free software; you can redistribute it and/or
> * modify it under the terms of the GNU Lesser General Public
> @@ -22,16 +22,36 @@
>
> #include <config.h>
>
> +#include <sys/types.h>
> #include <sys/stat.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <cap-ng.h>
>
> +#include "conf/domain_conf.h"
syntax-check would have told you unsafe cross-directory include - IOW
including conf/* files into util/* files is not allowed.
So I think you need to rethink where some of these functions will go. I
think they are mostly all used by the qemu_extdevice.c changes in patch
9, so perhaps they need to get folded into them. There at least you can
grab the conf/domain_conf.h file.
Probably best to do that... rather than passing the fields of
virDomainTPMDef into the functions instead.
Currently the functions have the prefix virTPM. That will have to change
- to qemuTPM? So I'll merge these functions into qemu_extdevice.c? or
another new file qemu_tpm.c ?
> +#include "viralloc.h"
syntax-check would have told you not to include "viralloc.h" twice...
obviously 'forgot' to run it.
> +#include "vircommand.h"
> #include "virstring.h"
> #include "virerror.h"
> #include "viralloc.h"
> #include "virfile.h"
> +#include "virkmod.h"
> +#include "virlog.h"
> #include "virtpm.h"
> +#include "virutil.h"
#include "viruuid.h" to get virUUIDGenerate
> +#include "configmake.h"
>
> #define VIR_FROM_THIS VIR_FROM_NONE
>
> +VIR_LOG_INIT("util.tpm")
> +
> +/*
> + * executables for the swtpm; to be found on the host
> + */
> +static char *swtpm_path;
> +static char *swtpm_setup;
> +static char *swtpm_ioctl;
> +
There's a love/hate relationship with static/globals...
> /**
> * virTPMCreateCancelPath:
> * @devpath: Path to the TPM device
> @@ -74,3 +94,517 @@ virTPMCreateCancelPath(const char *devpath)
> cleanup:
> return path;
> }
Two empty lines - pervasive comment here...
> +
> +/*
> + * virTPMEmulatorInit
> + *
> + * Initialize the Emulator functions by searching for necessary
> + * executables that we will use to start and setup the swtpm
> + */
> +static int
> +virTPMEmulatorInit(void)
> +{
> + if (!swtpm_path) {
> + swtpm_path = virFindFileInPath("swtpm");
> + if (!swtpm_path) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("Could not find swtpm 'swtpm' in
PATH"));
The message feels redundant.
You mean the repetition of 'swtpm' is redundant?
Should I adapt the reporting to use this type of command ?
if (!(qemunbd = virFindFileInPath("qemu-nbd"))) {
virReportSystemError(ENOENT, "%s",
_("Unable to find 'qemu-nbd' binary in
$PATH"));
goto cleanup;
}
+
> +/*
> + * virTPMEmulatorPrepareHost:
> + *
> + * @tpm: tpm definition
> + * @logDir: directory where swtpm writes its logs into
> + * @vmname: name of the VM
> + * @swtpm_user: uid to run the swtpm with
> + * @swtpm_group: gid to run the swtpm with
> + * @swtpmStateDir: directory for swtpm's persistent state
> + * @qemu_user: uid that qemu will run with; we share the socket file with it
> + * @shortName: short and unique name of the domain
> + *
> + * Prepare the log directory for the swtpm and adjust ownership of it and the
> + * log file we will be using. Prepare the state directory where we will share
> + * the socket between tss and qemu users.
> + */
> +int virTPMEmulatorPrepareHost(virDomainTPMDefPtr tpm,
> + const char *logDir, const char *vmname,
> + uid_t swtpm_user, gid_t swtpm_group,
> + const char *swtpmStateDir,
> + uid_t qemu_user, const char *shortName)
one line each argument
> +{
> + int ret = -1;
> +
> + if (virTPMEmulatorInit() < 0)
> + return -1;
> +
> + /* create log dir ... */
> + if (virFileMakePathWithMode(logDir, 0730) < 0)
> + goto cleanup;
I think we could just return -1; here.
> +
> + /* ... and adjust ownership */
> + if (virDirCreate(logDir, 0730, swtpm_user, swtpm_group,
> + VIR_DIR_CREATE_ALLOW_EXIST) < 0)
> + goto cleanup;
> +
> + /* create logfile name ... */
> + if (virAsprintf(&tpm->data.emulator.logfile,
"%s/%s-swtpm.log",
> + logDir, vmname) < 0)
> + goto cleanup;
> +
> + /* ... and make sure it can be accessed by swtpm_user */
> + if (virFileExists(tpm->data.emulator.logfile) &&
> + chown(tpm->data.emulator.logfile, swtpm_user, swtpm_group) < 0) {
> + virReportSystemError(errno,
> + _("Could not chown on swtpm logfile %s"),
> + tpm->data.emulator.logfile);
> + goto cleanup;
> + }
> +
> + /*
> + create our swtpm state dir ...
> + - QEMU user needs to be able to access the socket there
> + - swtpm group needs to be able to create files there
> + - in privileged mode 0570 would be enough, for non-privileged mode
> + we need 0770
> + */
> + if (virDirCreate(swtpmStateDir, 0770, qemu_user, swtpm_group,
> + VIR_DIR_CREATE_ALLOW_EXIST) < 0)
> + goto cleanup;
> +
> + /* create the socket filename */
> + if (!(tpm->data.emulator.source.data.nix.path =
> + virTPMCreateEmulatorSocket(swtpmStateDir, shortName)))
> + goto cleanup;
> + tpm->data.emulator.source.type = VIR_DOMAIN_CHR_TYPE_UNIX;
> +
> + ret = 0;
> +
> + cleanup:
> + if (ret)
> + VIR_FREE(tpm->data.emulator.logfile);
Does this matter? Wouldn't the logfile be free'd in a failure path by
virDomainTPMDefFree? If it does matter, use "if (ret < 0)".
I'll remove that but add a check for tpm->data.emulator.logfile before
'virAsprintf(&tpm->data.emulator.logfile,', so we don't have a memory
leak here.
> +
> + return ret;
> +}
> +
> +/*
> + * virTPMEmulatorRunSetup
> + *
> + * @storagepath: path to the directory for TPM state
> + * @vmname: the name of the VM
> + * @vmuuid: the UUID of the VM
> + * @privileged: whether we are running in privileged mode
> + * @swtpm_user: The userid to switch to when setting up the TPM;
> + * typically this should be the uid of 'tss' or 'root'
> + * @swtpm_group: The group id to switch to
> + * @logfile: The file to write the log into; it must be writable
> + * for the user given by userid or 'tss'
> + *
> + * Setup the external swtpm by creating endorsement key and
> + * certificates for it.
> + */
> +static int
> +virTPMEmulatorRunSetup(const char *storagepath, const char *vmname,
> + const unsigned char *vmuuid, bool privileged,
> + uid_t swtpm_user, gid_t swtpm_group,
> + const char *logfile)
One arg per line
> +{
> + virCommandPtr cmd = NULL;
> + int exitstatus;
> + int rc = 0;
Use ret = -1;
> + char uuid[VIR_UUID_STRING_BUFLEN];
> + char *vmid = NULL;
> + off_t logstart;
> +
> + if (!privileged) {
> + return virFileWriteStr(logfile,
> + _("Did not create EK and certificates since
"
> + "this requires privileged mode\n"),
> + 0600);
> + }
> +
> + cmd = virCommandNew(swtpm_setup);
> + if (!cmd) {
> + rc = -1;
> + goto cleanup;
> + }
Just goto cleanup; w/ @ret initialized to -1
> +
> + virUUIDFormat(vmuuid, uuid);
> + if (virAsprintf(&vmid, "%s:%s", vmname, uuid) < 0)
> + goto cleanup;
Because here you would have returned 0 and I don't think that's what
you'd expect at this point...
> +
> + virCommandSetUID(cmd, swtpm_user);
> + virCommandSetGID(cmd, swtpm_group);
> +
> + virCommandAddArgList(cmd,
> + "--tpm-state", storagepath,
> + "--vmid", vmid,
> + "--logfile", logfile,
> + "--createek",
> + "--create-ek-cert",
> + "--create-platform-cert",
> + "--lock-nvram",
> + "--not-overwrite",
> + NULL);
> +
> + virCommandClearCaps(cmd);
> +
> + /* get size of logfile */
> + logstart = virFileLength(logfile, -1);
> + if (logstart < 0)
> + logstart = 0;
> +
> + if (virCommandRun(cmd, &exitstatus) < 0 || exitstatus != 0) {
> + char *buffer = NULL, *errors;
> + off_t loglength = virFileLength(logfile, -1);
> +
> + if (loglength > logstart) {
> + ignore_value(virFileReadOffsetQuiet(logfile, logstart,
> + loglength - logstart,
> + &buffer));
On error @buffer could be NULL
> + errors = virStringFilterLines(buffer, "Error:", 160);
If @buffer == NULL, then the above is not going to work.
Also should it be _("Error:") or are we sure that the program is run
with a specific language (e.g. i18n concerns)? Since we don't control
the language of that output - it's a bit dicey to assume/use it.
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Could not run '%s'. exitstatus:
%d;\n"
> + "%s"),
> + swtpm_setup, exitstatus, errors);
Given the "concerns" raised, why not just direct the consumer to the
@logfile rather than trying to report the error into the output.
I had that before and thought it was more convenient to show to the user
what the problem was.
IOW:
if (virCommandRun(cmd, &exitstatus) < 0 || exitstatus != 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Could not run '%s'. exitstatus: %d;\n"
"Check error log '%s' for details."),
swtpm_setup, exitstatus, logfile);
goto cleanup;
}
If you really want to keep this logic, then handling buffer == NULL
before calling virStringFilterLines will need to be done and of course
handling that @errors wouldn't be filled in.
I am not insisting ... let me drop this along with patches 1 & 2.
> + VIR_FREE(buffer);
> + VIR_FREE(errors);
> + }
> + rc = -1;
goto cleanup;
> + }
> +
ret = 0;
> + cleanup:
> + VIR_FREE(vmid);
> + virCommandFree(cmd);
> +
> + return rc;
return ret;
> +}
> +
> +/*
> + * virTPMEmulatorBuildCommand:
> + *
> + * @tpm: TPM definition
> + * @vmname: The name of the VM
> + * @vmuuid: The UUID of the VM
> + * @privileged: whether we are running in privileged mode
> + * @swtpm_user: The uid for the swtpm to run as (drop privileges to from root)
> + * @swtpm_group: The gid for the swtpm to run as
> + *
> + * Create the virCommand use for starting the emulator
> + * Do some initializations on the way, such as creation of storage
> + * and emulator setup.
> + */
> +virCommandPtr
> +virTPMEmulatorBuildCommand(virDomainTPMDefPtr tpm, const char *vmname,
> + const unsigned char *vmuuid, bool privileged,
> + uid_t swtpm_user, gid_t swtpm_group)
One arg per line
> +{
> + virCommandPtr cmd = NULL;
> + bool created = false;
> +
> + if (virTPMCreateEmulatorStorage(tpm->data.emulator.storagepath,
> + &created, swtpm_user, swtpm_group) < 0)
> + return NULL;
> +
> + if (created &&
> + virTPMEmulatorRunSetup(tpm->data.emulator.storagepath, vmname, vmuuid,
> + privileged, swtpm_user, swtpm_group,
> + tpm->data.emulator.logfile) < 0)
> + goto error;
> +
> + unlink(tpm->data.emulator.source.data.nix.path);
> +
> + cmd = virCommandNew(swtpm_path);
> + if (!cmd)
> + goto error;
> +
> + virCommandClearCaps(cmd);
> +
> + virCommandAddArgList(cmd, "socket", "--daemon",
"--ctrl", NULL);
> + virCommandAddArgFormat(cmd, "type=unixio,path=%s,mode=0600",
> + tpm->data.emulator.source.data.nix.path);
> +
> + virCommandAddArg(cmd, "--tpmstate");
> + virCommandAddArgFormat(cmd, "dir=%s,mode=0600",
> + tpm->data.emulator.storagepath);
> +
> + virCommandAddArg(cmd, "--log");
> + virCommandAddArgFormat(cmd, "file=%s",
tpm->data.emulator.logfile);
> +
> + virCommandSetUID(cmd, swtpm_user);
> + virCommandSetGID(cmd, swtpm_group);
> +
> + return cmd;
> +
> + error:
> + if (created)
> + virTPMDeleteEmulatorStorage(tpm);
> +
> + VIR_FREE(tpm->data.emulator.source.data.nix.path);
> + VIR_FREE(tpm->data.emulator.storagepath);
Similar question here about the VIR_FREE's - why not wait for
virDomainTPMDefFree?
Dropped these as well.
> +
> + virCommandFree(cmd);
> +
> + return NULL;
> +}
> +
> +/*
> + * virTPMEmulatorStop
> + * @swtpmStateDir: A directory where the socket is located
> + * @shortName: short and unique name of the domain
> + *
> + * Gracefully stop the swptm
> + */
> +void
> +virTPMEmulatorStop(const char *swtpmStateDir, const char *shortName)
> +{
> + virCommandPtr cmd;
> + char *pathname;
> + char *errbuf = NULL;
> +
> + if (virTPMEmulatorInit() < 0)
> + return;
> +
> + if (!(pathname = virTPMCreateEmulatorSocket(swtpmStateDir, shortName)))
> + return;
> +
> + if (!virFileExists(pathname))
> + goto cleanup;
> +
> + cmd = virCommandNew(swtpm_ioctl);
> + if (!cmd) {
> + VIR_FREE(pathname);
^^^^
Done in cleanup anyway.
> + goto cleanup;
> + }
> +
> + virCommandAddArgList(cmd, "--unix", pathname, "-s", NULL);
> +
> + virCommandSetErrorBuffer(cmd, &errbuf);
> +
> + ignore_value(virCommandRun(cmd, NULL));
> +
> + virCommandFree(cmd);
> +
> + /* clean up the socket */
> + unlink(pathname);
> +
> + cleanup:
> + VIR_FREE(pathname);
> + VIR_FREE(errbuf);
> +}
> diff --git a/src/util/virtpm.h b/src/util/virtpm.h
> index b21fc05..63f75b8 100644
> --- a/src/util/virtpm.h
> +++ b/src/util/virtpm.h
> @@ -1,7 +1,7 @@
> /*
> * virtpm.h: TPM support
> *
> - * Copyright (C) 2013 IBM Corporation
> + * Copyright (C) 2013,2018 IBM Corporation
> *
> * This library is free software; you can redistribute it and/or
> * modify it under the terms of the GNU Lesser General Public
> @@ -22,6 +22,37 @@
> #ifndef __VIR_TPM_H__
> # define __VIR_TPM_H__
>
> +# include "vircommand.h"
> +
> +typedef struct _virDomainTPMDef virDomainTPMDef;
> +typedef virDomainTPMDef *virDomainTPMDefPtr;
> +
Duplicated from domain_conf.h to avoid errors, crafty...
I have a feeling most of this is going to be merged into patch 9...
Thanks for reviewing.
Stefan