diff options
| author | Fam Zheng <famz@redhat.com> | 2014-12-04 07:28:29 +0800 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2014-12-10 10:31:21 +0100 |
| commit | e5dc64b8ff09cc4c186273e4461c7479739db2ae (patch) | |
| tree | 058e90cb948f0d65a1af2959a815c2d95620c6b3 /block | |
| parent | 3ba235a02284c39b34a68a2a588508ffb52a7b55 (diff) | |
vmdk: Use g_random_int to generate CID
This replaces two "time(NULL)" invocations with "g_random_int()".
According to VMDK spec, CID "is a random 32‐bit value updated the first
time the content of the virtual disk is modified after the virtual disk
is opened". Using "seconds since epoch" is just a "lame way" to generate
it, and not completely safe because of the low precision.
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Don Koch <dkoch@verizon.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1417649314-13704-2-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/vmdk.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/block/vmdk.c b/block/vmdk.c index 2cbfd3e72e..ebb4b705f5 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -28,6 +28,7 @@ #include "qemu/module.h" #include "migration/migration.h" #include <zlib.h> +#include <glib.h> #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D') #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V') @@ -1538,7 +1539,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num, /* update CID on the first write every time the virtual disk is * opened */ if (!s->cid_updated) { - ret = vmdk_write_cid(bs, time(NULL)); + ret = vmdk_write_cid(bs, g_random_int()); if (ret < 0) { return ret; } @@ -1922,7 +1923,7 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp) } /* generate descriptor file */ desc = g_strdup_printf(desc_template, - (uint32_t)time(NULL), + g_random_int(), parent_cid, fmt, parent_desc_line, |