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@xxxxxxxxxxxxxxxxxx>
---
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
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