[Qemu-devel] [BUG, RFC] block/vmdk.c: File name with space fails to open

[Philipp Hahn]

Hello,

I tried to open a "twoGbMaxExtentSparse" VMDK file, which uses spaces in its 
own and for the referenced file names. This breaks in line 646 of 
block/vmdk.c because "%511s" stops at the first space and thus fname is 
incomplete:
        ret = sscanf(p, "%10s %" SCNd64 " %10s %511s %" SCNd64,
                access, &sectors, type, fname, &flat_offset);

I've only checked with our very old VMware workstation version, which refuses 
to create new images with unsupported characters with the following message:
> The characters !#%^&*><:;'"<>/? cannot be used.
So it looks like spaces are valid, at least we have several VMs with spaces in 
their name.

If the quotes around the file name are required, the simpliest solution would 
be to change %511s to "%511[^"]":

diff --git a/block/vmdk.c b/block/vmdk.c
index 19298c2..045f6a1 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -641,7 +641,7 @@ static int vmdk_parse_extents(const char *desc, 
BlockDriverState *bs,
          * RW [size in sectors] SPARSE "file-name.vmdk"
          */
         flat_offset = -1;
-        ret = sscanf(p, "%10s %" SCNd64 " %10s %511s %" SCNd64,
+        ret = sscanf(p, "%10s %" SCNd64 " %10s \"%511[^\"]\" %" SCNd64,
                 access, &sectors, type, fname, &flat_offset);
         if (ret < 4 || strcmp(access, "RW")) {
             goto next_line;

I don't know how portable %[ together with a maximum width is, because the 
manual page for sscanf() doesn't mention "max width" for "%[", but it works 
with Debian/GNU Linux Squeeze.

Sincerely
Philipp
-- 
Philipp Hahn           Open Source Software Engineer      h...@univention.de
Univention GmbH        be open.                       fon: +49 421 22 232- 0
Mary-Somerville-Str.1  D-28359 Bremen                 fax: +49 421 22 232-99
                                                   http://www.univention.de/

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