Allow creation of user creatable object types with qemu-nbd
via a new --object command line arg. This will be used to supply
passwords and/or encryption keys to the various block driver
backends via the recently added 'secret' object type.
# printf letmein > mypasswd.txt
# qemu-nbd --object secret,id=sec0,file=mypasswd.txt \
...other nbd args...
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
qemu-nbd.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
qemu-nbd.texi | 6 ++++++
2 files changed, 59 insertions(+)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index ede4a54..941c4c8 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -23,9 +23,12 @@
#include "qemu/main-loop.h"
#include "qemu/sockets.h"
#include "qemu/error-report.h"
+#include "qemu/config-file.h"
#include "block/snapshot.h"
#include "qapi/util.h"
#include "qapi/qmp/qstring.h"
+#include "qapi/opts-visitor.h"
+#include "qom/object_interfaces.h"
#include <stdarg.h>
#include <stdio.h>
@@ -44,6 +47,7 @@
#define QEMU_NBD_OPT_AIO 2
#define QEMU_NBD_OPT_DISCARD 3
#define QEMU_NBD_OPT_DETECT_ZEROES 4
+#define QEMU_NBD_OPT_OBJECT 5
static NBDExport *exp;
static int verbose;
@@ -77,6 +81,9 @@ static void usage(const char *name)
" -o, --offset=OFFSET offset into the image\n"
" -P, --partition=NUM only expose partition NUM\n"
"\n"
+"General purpose options:\n"
+" --object type,id=ID,... define an object such as 'secret' for providing\n"
+" passwords and/or encryption keys\n"
#ifdef __linux__
"Kernel NBD client support:\n"
" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
@@ -374,6 +381,35 @@ static SocketAddress *nbd_build_socket_address(const char
*sockpath,
}
+static QemuOptsList qemu_object_opts = {
+ .name = "object",
+ .implied_opt_name = "qom-type",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
+ .desc = {
+ { }
+ },
+};
+
+static int object_create(void *opaque, QemuOpts *opts, Error **errp)
+{
+ Error *err = NULL;
+ OptsVisitor *ov;
+ QDict *pdict;
+
+ ov = opts_visitor_new(opts);
+ pdict = qemu_opts_to_qdict(opts, NULL);
+
+ user_creatable_add(pdict, opts_get_visitor(ov), &err);
+ opts_visitor_cleanup(ov);
+ QDECREF(pdict);
+
+ if (err) {
+ error_propagate(errp, err);
+ return -1;
+ }
+ return 0;
+}
+
int main(int argc, char **argv)
{
BlockBackend *blk;
@@ -411,6 +447,7 @@ int main(int argc, char **argv)
{ "format", 1, NULL, 'f' },
{ "persistent", 0, NULL, 't' },
{ "verbose", 0, NULL, 'v' },
+ { "object", 1, NULL, QEMU_NBD_OPT_OBJECT },
{ NULL, 0, NULL, 0 }
};
int ch;
@@ -428,6 +465,7 @@ int main(int argc, char **argv)
Error *local_err = NULL;
BlockdevDetectZeroesOptions detect_zeroes =
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
QDict *options = NULL;
+ QemuOpts *opts;
/* The client thread uses SIGTERM to interrupt the server. A signal
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
@@ -436,6 +474,8 @@ int main(int argc, char **argv)
memset(&sa_sigterm, 0, sizeof(sa_sigterm));
sa_sigterm.sa_handler = termsig_handler;
sigaction(SIGTERM, &sa_sigterm, NULL);
+ module_call_init(MODULE_INIT_QOM);
+ qemu_add_opts(&qemu_object_opts);
qemu_init_exec_dir(argv[0]);
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
@@ -588,6 +628,13 @@ int main(int argc, char **argv)
usage(argv[0]);
exit(0);
break;
+ case QEMU_NBD_OPT_OBJECT:
+ opts = qemu_opts_parse_noisily(qemu_find_opts("object"),
+ optarg, true);
+ if (!opts) {
+ exit(1);
+ }
+ break;
case '?':
error_report("Try `%s --help' for more information.", argv[0]);
exit(EXIT_FAILURE);
@@ -600,6 +647,12 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
+ if (qemu_opts_foreach(qemu_find_opts("object"),
+ object_create,
+ NULL, NULL)) {
+ exit(1);
+ }
+
if (disconnect) {
fd = open(argv[optind], O_RDWR);
if (fd < 0) {
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 46fd483..9f9daca 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -14,6 +14,12 @@ Export QEMU disk image using NBD protocol.
@table @option
@item @var{filename}
is a disk image filename
+@item --object type,id=@var{id},...props...
+ define a new instance of the @var{type} object class identified by @var{id}.
+ See the @code{qemu(1)} manual page for full details of the properties
+ supported. The common object type that it makes sense to define is the
+ @code{secret} object, which is used to supply passwords and/or encryption
+ keys.
@item -p, --port=@var{port}
port to listen on (default @samp{10809})
@item -o, --offset=@var{offset}
--
2.5.0
