This allows strings to be transported between client and server
in the context of name-type-value virTypedParameter functions.
For compatibility,
o new clients will not send strings to old servers, based on
a feature check
o new servers will not send strings to old clients without the
flag VIR_TYPED_PARAM_STRING_OKAY; this will be enforced at
the RPC layer in the next patch, so that drivers need not
worry about it in general. The one exception is that
virDomainGetSchedulerParameters lacks a flags argument, so
it must not return a string; drivers that forward that
function on to virDomainGetSchedulerParametersFlags will
have to pay attention to the flag.
o the flag VIR_TYPED_PARAM_STRING_OKAY is set automatically,
based on a feature check (so far, no driver implements it),
so clients do not have to worry about it
Future patches can then enable the feature on a per-driver basis.
This patch also ensures that drivers can blindly strdup() field
names (previously, a malicious client could stuff 80 non-NUL bytes
into field and cause a read overrun).
* src/libvirt_internal.h (VIR_DRV_FEATURE_TYPED_PARAM_STRING): New
driver feature.
* src/libvirt.c (virTypedParameterValidateSet)
(virTypedParameterSanitizeGet): New helper functions.
(virDomainSetMemoryParameters, virDomainSetBlkioParameters)
(virDomainSetSchedulerParameters)
(virDomainSetSchedulerParametersFlags)
(virDomainGetMemoryParameters, virDomainGetBlkioParameters)
(virDomainGetSchedulerParameters)
(virDomainGetSchedulerParametersFlags, virDomainBlockStatsFlags):
Use them.
* src/util/util.h (virTypedParameterArrayClear): New helper
function.
* src/util/util.c (virTypedParameterArrayClear): Implement it.
* src/libvirt_private.syms (util.h): Export it.
Based on an initial patch by Hu Tao, with feedback from
Daniel P. Berrange.
Signed-off-by: Eric Blake <eblake@redhat.com>