We commonly use the error API like this:
err = NULL;
foo(..., &err);
if (err) {
goto out;
}
bar(..., &err);
Every error source is checked separately. The second function is only
called when the first one succeeds. Both functions are free to pass
their argument to error_set(). Because error_set() asserts no error
has been set, this effectively means they must not be called with an
error set.
The qapi-generated code uses the error API differently:
// *errp was initialized to NULL somewhere up the call chain
frob(..., errp);
gnat(..., errp);
Errors accumulate in *errp: first error wins, subsequent errors get
dropped. To make this work, the second function does nothing when
called with an error set. Requires non-null errp, or else the second
function can't see the first one fail.
This usage has also bled into visitor tests, and two device model
object property getters rtc_get_date() and balloon_stats_get_all().
With the "accumulate" technique, you need fewer error checks in
callers, and buy that with an error check in every callee. Can be
nice.
However, mixing the two techniques is confusing. You can't use the
"accumulate" technique with functions designed for the "check
separately" technique. You can use the "check separately" technique
with functions designed for the "accumulate" technique, but then
error_set() can't catch you setting an error more than once.
Standardize on the "check separately" technique for now, because it's
overwhelmingly prevalent.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Semantics of end_optional() differ subtly from the other end_FOO()
callbacks: when start_FOO() succeeds, the matching end_FOO() gets
called regardless of what happens in between. end_optional() gets
called only when everything in between succeeds as well. Entirely
undocumented, like all of the visitor API.
The only user of Visitor Callback end_optional() never did anything,
and was removed in commit 9f9ab46.
I'm about to clean up error handling in the generated visitor code,
and end_optional() is in my way. No users mean no test cases, and
making non-trivial cleanup transformations without test cases doesn't
strike me as a good idea.
Drop end_optional(), and rename start_optional() to optional(). We
can always go back to a pair of callbacks when we have an actual need.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
These have never been called or implemented by anything, and their
intended use is undocumented, like all of the visitor API.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This reverts commit 25a7017555.
Turns out the argument *can* be null: QEMU now segfaults if it
receives an invalid parameter via a qmp command instead of throwing an
error.
For example:
{ "execute": "blockdev-add",
"arguments": { "options" : { "driver": "invalid-driver" } } }
CC: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Using error_is_set(ERRP) to find out whether a function failed is
either wrong, fragile, or unnecessarily opaque. It's wrong when ERRP
may be null, because errors go undetected when it is. It's fragile
when proving ERRP non-null involves a non-local argument. Else, it's
unnecessarily opaque (see commit 84d18f0).
The error_is_set(errp) in do_qmp_dispatch() is merely fragile, because
the caller never passes a null errp argument.
Make the code more robust and more obviously correct: receive the
error in a local variable, then propagate it through the parameter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
do_qmp_dispatch()'s test for qmp_dispatch_check_obj() failure examines
both the return value and the error object. The latter part is
unclean; it works only when do_qmp_dispatch()'s caller passes a
non-null errp argument. That's the case, but it's not locally
obvious. Unclean.
Cleanup would be easy enough, but since the unclean code is also
redundant, let's just drop it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
strtosz_suffix() might return negative error, this patch fixes
the error handling.
This patch also changes to handle error in the if statement
rather than handle success specially, this will make this use
of strtosz_suffix consistent with all other uses.
Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Just hardcode them in the callers
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Argument is null when visiting an unboxed struct. I can't see such a
visit in the current code. Fix it anyway.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Argument can't be null. No other Visitor method type_str() checks for
null.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This fixes several bugs or shortcomings of the previous pretty-printer.
In particular:
* use PRIu64 instead of casting to long long
* the exact value is included too
* the correct unit of measure (MiB, GiB, etc.) is used. PiB and EiB
are added too.
* due to an off-by-one error, 512*2^30 was printed as 0.500MiB rather than
512MiB. floor(log2(val)) is equal to 63 - clz(val), while the code used 64.
* The desired specification is %g rather than %f, which always uses three
decimals in the current code. However %g would switch to scientific
notation when the integer part is >= 1000 (e.g. 1000*2^30). To keep the
code simple, switch to the higher power when the integer part is >= 1000;
overflow is avoided by using frexp instead of clz.
Suggested-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This will be used by "info qtree". For numbers it prints both the
decimal and hex values. For sizes it rounds to the nearest power
of 2^10. For strings, it puts quotes around the string and separates
NULL and empty string.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Now we have several qemu-ga commands not returning response on success.
It has been documented in qga/qapi-schema.json already. This patch exposes
the 'success-response' flag by extending 'guest-info' command. With this
change, the clients can handle the command response more flexibly.
Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
*fixed up commit subject
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
In the original code, qmp_get_command_list is used to construct
a list of all commands' name. To get the information of all qga
commands, it traverses the name list and search the command info
with its name. So it can cause O(n^2) in the number of commands.
This patch adds an interface to traverse the qmp command list by
QmpCommand to replace qmp_get_command_list. It can decrease the
complexity from O(n^2) to O(n).
Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
*fix up commit subject
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Prevent mistyped command line options from incurring high memory and CPU
usage at startup. 64K elements in a range should be enough for everyone
(TM).
The OPTS_VISITOR_RANGE_MAX macro is public so that unit tests can
construct corner cases with it.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
When a well-formed range value, bounded by unsigned integers, is
encountered while processing a repeated option, enter LM_UNSIGNED_INTERVAL
and return the low bound.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Simplify the code in preparation for the next patch.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
When a well-formed range value, bounded by signed integers, is encountered
while processing a repeated option, enter LM_SIGNED_INTERVAL and return
the low bound.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The new modes are equal-rank, exclusive alternatives of LM_IN_PROGRESS.
Teach opts_next_list(), opts_type_int() and opts_type_uint64() to handle
them.
Also enumerate explicitly what functions are valid to call in what modes:
- opts_next_list() is valid to call while flattening a range,
- opts_end_list(): ditto,
- lookup_scalar() is invalid to call during flattening; generated qapi
traversal code must continue asking for the same kind of signed/unsigned
list element until the interval is fully flattened,
- processed(): ditto.
List mode restrictions are always formulated in positive / inclusive
sense. The restrictions for lookup_scalar() and processed() are
automatically satisfied by current qapi traversals if the schema to build
is compatible with OptsVisitor.
The new list modes are not entered yet.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
We're going to need more state while processing a list of repeated
options. This change eliminates "repeated_opts_first" and adds a new state
variable:
list_mode repeated_opts repeated_opts_first
-------------- ------------- -------------------
LM_NONE NULL false
LM_STARTED non-NULL true
LM_IN_PROGRESS non-NULL false
Additionally, it is documented that lookup_scalar() and processed(), both
called by opts_type_XXX(), are invalid in LM_STARTED -- generated qapi
code calls opts_next_list() to allocate the very first link before trying
to parse a scalar into it. List mode restrictions are expressed in
positive / inclusive form.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Currently visit_type_size checks if the visitor's type_size function pointer is
NULL. If not, it calls it, otherwise it calls v->type_uint64(). But neither of
these pointers are ever set. Fallback to calling v->type_int() in this third
(default) case.
Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Message-id: 1375109277-25561-6-git-send-email-imammedo@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The discriminator for anonymous unions is the data type. This allows to
have a union type that allows both of these:
{ 'file': 'my_existing_block_device_id' }
{ 'file': { 'filename': '/tmp/mydisk.qcow2', 'read-only': true } }
Unions like this are specified in the schema with an empty dict as
discriminator. For this example you could take:
{ 'union': 'BlockRef',
'discriminator': {},
'data': { 'definition': 'BlockOptions',
'reference': 'str' } }
{ 'type': 'ExampleObject',
'data: { 'file': 'BlockRef' } }
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This allows to just look at the next element without actually consuming
it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
These can be used when an embedded struct is parsed and members not
belonging to the struct may be present in the input (e.g. parsing a
flat namespace QMP union, where fields from both the base and one
of the alternative types are mixed in the JSON object)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Note that we already free with g_free().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The file is only including error.h and qerror.h. Prefer explicit
inclusion of whatever files are needed.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Include:
- <glib.h> for g_malloc0()
- <string.h> for strcmp()
Some of those headers were probably being included by accident because
some other headers were including qemu-common.h, but those headers
should eventually stop including qemu-common.h.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The second parameter to qapi_dealloc_type_size should be a uint64_t *,
not a size_t *. This was causing our 32 bit x86 build to fail, since
warnings are treated as errors.
Signed-off-by: Bruce Rogers <brogers@suse.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
visit_type_size() requires either visitor->type_size() or
visitor_uint64() to be implemented, otherwise a NULL function pointer is
invoked.
It is possible to trigger this crash as follows:
$ qemu-system-x86_64 -netdev tap,sndbuf=0,id=netdev0 \
-device virtio-blk-pci,netdev=netdev0
The 'sndbuf' option has type "size".
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
valgrind report:
==24534== 232 bytes in 2 blocks are definitely lost in loss record 1,245 of 1,601
==24534== at 0x4824F20: malloc (vg_replace_malloc.c:236)
==24534== by 0x293C88: malloc_and_trace (vl.c:2281)
==24534== by 0x489AD99: ??? (in /lib/libglib-2.0.so.0.2400.1)
==24534== by 0x489B23B: g_malloc0 (in /lib/libglib-2.0.so.0.2400.1)
==24534== by 0x2B4EFC: opts_visitor_new (opts-visitor.c:376)
==24534== by 0x29DEA5: net_client_init (net.c:708)
==24534== by 0x29E6C7: net_init_client (net.c:966)
==24534== by 0x2C2179: qemu_opts_foreach (qemu-option.c:1114)
==24534== by 0x29E85B: net_init_clients (net.c:1008)
==24534== by 0x296F40: main (vl.c:3463)
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
error_get_qobject() is unused since last commit, error_set_qobject()
has never been used. Also drops error_int.h.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
IMPORTANT: this BREAKS qemu-ga compatibility for the error response.
Instead of returning something like:
{ "error": { "class": "InvalidParameterValue",
"data": {"name": "mode", "expected": "halt|powerdown|reboot" } } }
qemu-ga now returns:
{ "error": { "class": "GenericError",
"desc": "Parameter 'mode' expects halt|powerdown|reboot" } }
Notice that this is also a bug fix, as qemu-ga wasn't returning the
human message.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
This visitor supports parsing
-option [type=]discriminator[,optarg1=val1][,optarg2=val2][,...]
style QemuOpts objects into "native" C structures. After defining the type
tree in the qapi schema (see below), a root type traversal with this
visitor linked to the underlying QemuOpts object will build the "native" C
representation of the option.
The type tree in the schema, corresponding to an option with a
discriminator, must have the following structure:
struct
scalar member for non-discriminated optarg 1 [*]
list for repeating non-discriminated optarg 2 [*]
wrapper struct
single scalar member
union
struct for discriminator case 1
scalar member for optarg 3 [*]
list for repeating optarg 4 [*]
wrapper struct
single scalar member
scalar member for optarg 5 [*]
struct for discriminator case 2
...
The "type" optarg name is fixed for the discriminator role. Its schema
representation is "union of structures", and each discriminator value must
correspond to a member name in the union.
If the option takes no "type" descriminator, then the type subtree rooted
at the union must be absent from the schema (including the union itself).
Optarg values can be of scalar types str / bool / integers / size.
Members marked with [*] may be defined as optional in the schema,
describing an optional optarg.
Repeating an optarg is supported; its schema representation must be "list
of structure with single mandatory scalar member". If an optarg is not
described as repeating in the schema (ie. it is defined as a scalar field
instead of a list), its last occurrence will take effect. Ordering between
differently named optargs is not preserved.
A mandatory list (or an optional one which is reported to be available),
corresponding to a repeating optarg, has at least one element after
successful parsing.
v1->v2:
- Update opts_type_size() prototype to uint64_t.
- Add opts_type_uint64() for options needing the full uint64_t range.
(Internals could be extracted to "cutils.c".)
- Allow negative values in opts_type_int().
- Rebase to nested Makefiles.
v2->v3:
- Factor opts_visitor_insert() out of opts_start_struct() and call it
separately for opts_root->id if there's any.
- Don't require non-negative values in opts_type_int()'s error message.
- g_malloc0() may return NULL for zero-sized requests. Support empty
structures by requesting 1 byte for them instead.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
v1->v2:
- fall back to uint64 rather than int
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Don't overwrite / leak previously set errors.
Make traversal cope with missing mandatory sub-structs.
Don't try to end a container that could not be started.
v1->v2:
- unchanged
v2->v3:
- instead of examining, assert that we never overwrite errors with
error_set()
- allow visitors to set a NULL struct pointer successfully, so traversal
of incomplete objects can continue
- check for a NULL "obj" before accessing "(*obj)->has_XXX" (this is not a
typo, "obj != NULL" implies "*obj != NULL" here)
- fix start_struct / end_struct balance for unions as well
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The enum string is pointed to by 'enum_str' not 'name'. This bug
causes the error message to be:
{ "error": { "class": "InvalidParameter",
"desc": "Invalid parameter 'null'",
"data": { "name": "null" } } }
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
The comment is stale, monitor.h is not needed anymore (only qerror.h
is, because it contains the schema for errors).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Currently string-output-visitor formats floats as %g, which is nice in
that trailing 0's are automatically truncated, but otherwise this causes
some issues:
- it uses 6 significant figures instead of 6 decimal places, which
means something like 155777.5 (which even has an exact floating point
representation) will be rounded to 155778 when converted to a string.
- output will be presented in scientific notation when the normalized
form requires a 10^x multiplier. Not a huge deal, but arguably less
readable for command-line arguments.
- due to using scientific notation for numbers requiring more than 6
significant figures, instead of hard-defined decimal places, it
fails a lot of the test-visitor-serialization unit tests for floats.
Instead, let's just use %f, which is what the QJSON and the QMP visitors
use.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
This adds visitor interfaces for fixed-width integers types.
Implementing these in visitors is optional, otherwise we fall back to
visit_type_int() (int64_t) with some additional bounds checking to avoid
integer overflows for cases where the value fetched exceeds the bounds
of our target C type.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[LE: exclude negative values in uint*_t Visitor interfaces]
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
[AF: Merged fix by Laszlo]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Options allow for changes in commands behavior. This commit introduces
the QCO_NO_SUCCESS_RESP option, which causes a command to not emit a
success response.
This is needed by commands such as qemu-ga's guest-shutdown, which
may not be able to complete before the VM vanishes. In this case, it's
useful and simpler not to bother sending a success response.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
JSON numbers can be interpreted as either integers or floating point
values depending on their representation. As a result, QMP input visitor
might visit a QInt when it was expecting a QFloat, so add handling to
account for this.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Andreas Färber <afaerber@suse.de>
Currently we rely on fsfreeze/thaw commands disabling/enabling logging
then having other commands check whether logging is disabled to avoid
executing if they aren't safe for running while a filesystem is frozen.
Instead, have an explicit whitelist of fsfreeze-safe commands, and
consolidate logging and command enablement/disablement into a pair
of helper functions: ga_set_frozen()/ga_unset_frozen()
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
GHashTableIter was first introduced in glib 2.16.
This patch removes it in favor of older g_hash_table_find()
for better compatibility with RHEL5.
Signed-off-by: NODA, Kai <nodakai@gmail.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
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>
Stack entries in QmpOutputVisitor are navigation links (weak references),
except the bottom (ie. least recently added) entry, which owns the root
QObject [1]. Make qmp_output_visitor_cleanup() drop the stack entries,
then release the QObject tree by the root.
Attempting to serialize an invalid enum inside a dictionary is an example
for triggering the double free.
[1] http://lists.nongnu.org/archive/html/qemu-devel/2012-03/msg03276.html
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
String based visitors provide a consistent interface for parsing
strings to C values, as well as consuming C values as strings.
They will be used to parse command-line options.
Signed-off-by: Paolo Bonzini <pbonzini@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>
Not that there is blacklisting functionality we can no longer infer
the agent's capabilities via version. This patch extends the current
guest-info RPC to also return a list of dictionaries containing the name
of each supported RPC, along with a boolean indicating whether or not
the command has been disabled by a guest administrator/distro.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This adds a command-line option, -b/--blacklist, that accepts a
comma-seperated list of RPCs to disable, or prints a list of
available RPCs if passed "?".
In consequence this also adds general blacklisting and RPC listing
facilities to the new QMP dispatch/registry facilities, should the
QMP monitor ever have a need for such a thing.
Ideally, to avoid support/compatability issues in the future,
blacklisting guest agent functionality will be the exceptional
case, but we add the functionality here to handle guest administrators
with specific requirements.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We don't currently check for negative enum values in qmp_output_type_enum(),
this will very likely generate a segfault when triggered.
However, it _seems_ that no code in tree can trigger this today.
Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.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>
Previously our logic for keeping track of when we're visiting the head
of a list was done via a global bool. This can be overwritten if dealing
with nested lists, so use stack entries to track this instead.
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>
Currently we do 3 things wrong:
1) The list iterator, in practice, is used in a manner where the pointer
we pass in is the same as the pointer we assign the output to from
visit_next_list(). This causes an infinite loop where we keep freeing
the same structures.
2) We attempt to free list->value rather than list. visit_type_<type>
handles this. We should only be concerned with the containing list.
3) We free prematurely: iterator function will continue accessing values
we've already freed.
This patch should fix all of these issues. QmpOutputVisitor also suffers
from 1).
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>
To get the ball rolling merging QAPI, this patch introduces a "middle mode" to
the code generator. In middle mode, the code generator generates marshalling
functions that are compatible with the current QMP server. We absolutely need
to replace the current QMP server in order to support proper asynchronous
commands but using a middle mode provides a middle-ground that lets us start
converting commands in tree.
Note that all of the commands have been converted already in my glib branch.
Middle mode only exists until we finish merging them from my branch into the
main tree.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Given an object recieved via QMP, this code uses the dispatch table
provided by qmp_registry.c to call the corresponding marshalling/dispatch
function and format return values/errors for delivery to the QMP.
Currently only synchronous QMP functions are supported, but this will
also be used for async QMP functions and QMP guest proxy dispatch as
well.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
Registration/lookup functions for that provide a lookup table for
dispatching QMP commands.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
Type of Visitor class that can be passed into a qapi-generated C
type's visitor function to free() any heap-allocated data types.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
Type of Visiter class that serves as the inverse of the input visitor:
it takes a series of native C types and uses their values to construct a
corresponding QObject. The command marshaling/dispatcher functions will
use this to convert the output of QMP functions into a QObject that can
be sent over the wire.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.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>
Base definitions/includes for Visiter interface used by generated
visiter/marshalling code.
Includes a GenericList type. Our lists require an embedded element.
Since these types are generated, if you want to use them in a different
type of data structure, there's no easy way to add another embedded
element. The solution is to have non-embedded lists and that what this is.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
