While QMP in general is designed so that it is possible to ignore
unknown arguments, in the case of the QMP server it is better to
reject them to detect bad clients. In fact, we're already doing
this at the top level in the argument checker. To extend this to
complex structures, add a mode to the input visitor where it checks
for unvisited keys and raises an error if it finds one.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This is a slight change in the implementation of QMPInputVisitor
that helps when adding strict mode.
Const QObjects cannot be inc/decref-ed, and that's why QMPInputVisitor
relies heavily on weak references to inner objects. I'm not removing
the weak references now, but since refcount+const is a lost battle in C
(C++ has "mutable") I think removing const is fine in this case.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Right now, the semantics of next_list are complicated. The caller must:
* call start_list
* call next_list for each element *including the first*
* on the first call to next_list, the second argument should point to
NULL and the result is the head of the list. On subsequent calls,
the second argument should point to the last node (last result of
next_list) and next_list itself tacks the element at the tail of the
list.
This works for both input and output visitor, but having the visitor
write memory when it is only reading the list is ugly. Plus, relying
on *list to detect the first call is tricky and undocumented.
We can initialize so->entry in next_list instead of start_list, leaving
it NULL in start_list. This way next_list sees clearly whether it is
on the first call---as a bonus, it discriminates the cases based on
internal state of the visitor rather than external state. We can
also pull the assignment of the list head from generated code up to
next_list.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
QmpInputVisitor would leak the malloced struct if the stack was
overflowed. This can be easily fixed using error_propagate.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
QmpOutputVisitor will segfault if an imbalanced end function is
called. So we can abort in QmpInputVisitor too.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
A NULL qobj can occur when a parameter is fetched via qdict_get, but
the parameter is not in the command. By returning NULL, the caller can
choose whether to raise a missing parameter error, an invalid parameter
type error, or use a default value. For example, qom-set could can
use this to reset a property to its default value, though at this time
it will fail with "Invalid parameter type". In any case, anything is
better than crashing!
Reviewed-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Modify logic such that we never assign values to the list head argument
to progress through the list on subsequent iterations, instead rely only
on having our return value passed back in as an argument on the next
call. Also update QMP I/O visitors and test cases accordingly, and add a
missing test case for QmpOutputVisitor.
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
A type of Visiter class that is used to walk a qobject's
structure and assign each entry to the corresponding native C type.
Command marshaling function will use this to pull out QMP command
parameters recieved over the wire and pass them as native arguments
to the corresponding C functions.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
