2:35 p.m.
Is there any sample code available to demonstrate the use of the
guestfs_hivex_node_set_value API?
I have no problem traversing and reading keys using libguestfs hivex
wrappers - but continue to fail on any write attempts.
The return is always -1 and errno is unchanged.
I've set the environment variable HIVEX_DEBUG to 1 on a chance that
this may help - but it doesn't.
The only sample I can find in the sources that use hivex is the
"virt-dhcp-address.c" sample.
But it does not write to the registry.
4:29 p.m.
On Mon, Dec 03, 2012 at 03:35:49PM -0500, Skippy VonDrake wrote:
Is there any sample code available to demonstrate the use of the
guestfs_hivex_node_set_value API?
I don't think any real code uses this API. They all use the more
useful hivex_node_set_values instead (which is not bound yet via the
libguestfs API -- a missing feature).
However there is some test code:
https://github.com/libguestfs/hivex/blob/master/perl/t/210-setvalue.t
I have no problem traversing and reading keys using libguestfs hivex
wrappers - but continue to fail on any write attempts.
The return is always -1 and errno is unchanged.
It's entirely possible that the libguestfs bindings are buggy. See:
https://github.com/libguestfs/libguestfs/blob/master/daemon/hivex.c#L383
I've set the environment variable HIVEX_DEBUG to 1 on a chance
that
this may help - but it doesn't.
No, unfortunately this environment variable is not passed through to
the daemon. You could try doing:
guestfs_h *g = guestfs_create ();
guestfs_set_verbose (g, 1);
// ...
guestfs_launch (g);
// ...
char *env[] = { "HIVEX_DEBUG", 1 };
guestfs_debug (g, "setenv", env);
all before calling guestfs_hivex_open.
The only sample I can find in the sources that use hivex is the
"virt-dhcp-address.c" sample.
But it does not write to the registry.
Probably best to look at perl code in hivex for some ideas, eg:
https://github.com/libguestfs/hivex/blob/master/perl/lib/Win/Hivex/Regedi...
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
4:33 p.m.
On Mon, Dec 03, 2012 at 10:29:52PM +0000, Richard W.M. Jones wrote:
On Mon, Dec 03, 2012 at 03:35:49PM -0500, Skippy VonDrake wrote:
> I've set the environment variable HIVEX_DEBUG to 1 on a chance that
> this may help - but it doesn't.
No, unfortunately this environment variable is not passed through to
the daemon. You could try doing:
Or even easier:
guestfs_hivex_open (g, filename,
GUESTFS_HIVEX_OPEN_VERBOSE, 1,
GUESTFS_HIVEX_OPEN_DEBUG, 1,
-1);
However you will still need to enable libguestfs debugging
(guestfs_set_verbose (g, 1)) in order to see any output from hivex,
since it's all running inside the appliance.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
11:01 a.m.
On Mon, Dec 03, 2012 at 03:35:49PM -0500, Skippy VonDrake wrote:
Is there any sample code available to demonstrate the use of the
guestfs_hivex_node_set_value API?
I have no problem traversing and reading keys using libguestfs hivex
wrappers - but continue to fail on any write attempts.
The return is always -1 and errno is unchanged.
I've set the environment variable HIVEX_DEBUG to 1 on a chance that
this may help - but it doesn't.
The only sample I can find in the sources that use hivex is the
"virt-dhcp-address.c" sample.
But it does not write to the registry.
Just to close this issue for other readers, the problem was not
supplying the 'write' flag when calling guestfs_hivex_open. If you
don't supply this flag, then writes will fail with
guestfs_last_errno(g) => EROFS.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
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Skippy VonDrake