The virDBusMethodCall method has a DBusError as one of its
parameters. If the caller wants to pass a non-NULL value
for this, it immediately makes the calling code require
DBus at build time. This has led to breakage of non-DBus
builds several times. It is desirable that only the virdbus.c
file should need WITH_DBUS conditionals, so we must ideally
remove the DBusError parameter from the method.
We can't simply raise a libvirt error, since the whole point
of this parameter is to give the callers a way to check if
the error is one they want to ignore, without having the logs
polluted with an error message. So, we add a virErrorPtr
parameter which the caller can then either ignore or raise
using the new virReportErrorObject method.
This new method is distinct from virSetError in that it
ensures the logging hooks are run.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This is the only callsite.
We drop use of localerror.name here, because it's not actually useful
to us: rather than the parameter name which received an invalid value
(which was assumed), it's actually the the dbus errno equivalent.
Just use the error string.
Acked-by: Eric Blake <eblake@redhat.com>
Some of our operation denied messages are outright stupid; for
example, if virIdentitySetAttr fails:
error: operation Identity attribute is already set forbidden for read only access
This patch fixes things to a saner:
error: operation forbidden: Identity attribute is already set
It also consolidates the most common usage pattern for operation
denied errors: read-only connections preventing a public API. In
this case, 'virsh -r -c test:///default destroy test' changes from:
error: operation virDomainDestroy forbidden for read only access
to:
error: operation forbidden: read only access prevents virDomainDestroy
Note that we were previously inconsistent on which APIs used
VIR_FROM_DOM (such as virDomainDestroy) vs. VIR_FROM_NONE (such as
virDomainPMSuspendForDuration). After this patch, all uses
consistently use VIR_FROM_NONE, on the grounds that it is unlikely
that a caller learning that a call is denied can do anything in
particular with extra knowledge which error domain the call belongs
to (similar to what we did in commit baa7244).
* src/util/virerror.c (virErrorMsg): Rework OPERATION_DENIED error
message.
* src/internal.h (virCheckReadOnlyGoto): New macro.
* src/util/virerror.h (virReportRestrictedError): New macro.
* src/libvirt-lxc.c: Use new macros.
* src/libvirt-qemu.c: Likewise.
* src/libvirt.c: Likewise.
* src/locking/lock_daemon.c (virLockDaemonClientNew): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
We weren't very consistent in our use of VIR_ERR_NO_SUPPORT; many
users just passed __FUNCTION__ on, while others passed "%s" to
silence over-eager compilers that warn about __FUNCTION__ not
containing any %. It's nicer to route all these uses through
a single macro, so that if we ever need to change the reporting,
we can do it in one place.
I verified that 'virsh -c test:///default qemu-monitor-command test foo'
gives the same error message before and after this patch:
error: this function is not supported by the connection driver: virDomainQemuMonitorCommand
Note that in libvirt.c, we were inconsistent on whether virDomain*
API used virLibConnError() (with VIR_FROM_NONE) or virLibDomainError()
(with VIR_FROM_DOMAIN); this patch unifies these errors to all use
VIR_FROM_NONE, on the grounds that it is unlikely that a caller
learning that a call is unimplemented can do anything in particular
with extra knowledge of which error domain it belongs to.
One particular change to note is virDomainOpenGraphics which was
trying to fail with VIR_ERR_NO_SUPPORT after a failed
VIR_DRV_SUPPORTS_FEATURE check; all other places that fail a
feature check report VIR_ERR_ARGUMENT_UNSUPPORTED.
* src/util/virerror.h (virReportUnsupportedError): New macro.
* src/libvirt-qemu.c: Use new macro.
* src/libvirt-lxc.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
* src/security/security_manager.c: Likewise.
* src/util/virinitctl.c: Likewise.
* src/libvirt.c: Likewise.
(virDomainOpenGraphics): Use correct error for unsupported feature.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add virErrorSetErrnoFromLastError and virLastErrorIsSystemErrno
to simplify code which wants to handle system errors in a more
graceful fashion.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Doing DBus method calls using libdbus.so is tedious in the
extreme. systemd developers came up with a nice high level
API for DBus method calls (sd_bus_call_method). While
systemd doesn't use libdbus.so, their API design can easily
be ported to libdbus.so.
This patch thus introduces methods virDBusCallMethod &
virDBusMessageRead, which are based on the code used for
sd_bus_call_method and sd_bus_message_read. This code in
systemd is under the LGPLv2+, so we're license compatible.
This code is probably pretty unintelligible unless you are
familiar with the DBus type system. So I added some API
docs trying to explain how to use them, as well as test
cases to validate that I didn't screw up the adaptation
from the original systemd code.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
