Commit 871e51d2d4 changed the sign on the xenlight error types (making
the values negative, same as the C-generated constants), but failed to
remove the code changing the sign before casting to Error(). This
results in error strings like "libxl error: <x>", rather than the
correct message. Fix all occurrances of this by running:
gofmt -w -r 'Error(-ret) -> Error(ret)' xenlight.go
from tools/golang/xenlight.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
As a matter of style, it is strange to see capitalized receiver names,
due to the significance of capitalized symbols in Go (although there is
in fact nothing special about a capitalized receiver name). Fix this in
xenlight.go by running:
gofmt -w -r 'Ctx -> ctx' xenlight.go
from tools/golang/xenlight. There is no functional change.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Currently, when marshalig Go types with keyed union fields, we assign the
value of the struct (e.g. DomainBuildInfoTypeUnionHvm) which implements the
interface of the keyed union field (e.g. DomainBuildInfoTypeUnion).
As-is, this means that if a populated DomainBuildInfo is marshaled to
e.g. JSON, unmarshaling back to DomainBuildInfo will fail.
When the encoding/json is unmarshaling data into a Go type, and
encounters a JSON object, it basically can either marshal the data into
an empty interface, a map, or a struct. It cannot, however, marshal data
into an interface with at least one method defined on it (e.g.
DomainBuildInfoTypeUnion). Before this check is done, however, the
decoder will check if the Go type is a pointer, and dereference it if
so. It will then use the type of this value as the "target" type.
This means that if the TypeUnion field is populated with a
DomainBuildInfoTypeUnion, the decoder will see a non-empty interface and
fail. If the TypeUnion field is populated with a
*DomainBuildInfoTypeUnionHvm, it dereferences the pointer and sees a
struct instead, allowing decoding to continue normally.
Since there does not appear to be a strict need for NOT using pointers
in these fields, update code generation to set keyed union fields to
pointers of their implementing structs.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
For structs that have a keyed union, e.g. DomainBuildInfo, the TypeUnion
field must be exported so that package users can get/set the fields
within. This means that users are aware of the existence of the
interface type used in those fields (see [1]), so it is awkward that the
interface itself is not exported. However, the single method within the
interface must remain unexported so that users cannot mistakenly "implement"
those interfaces.
Since there seems to be no reason to do otherwise, export the keyed
union interface types.
[1] https://pkg.go.dev/xenbits.xenproject.org/git-http/xen.git/tools/golang/xenlight?tab=doc#DeviceUsbdev
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
The current implementation of StringList.toC does not correctly account
for how libxl_string_list is expected to be laid out in C, which is clear
when one looks at libxl_string_list_length in libxl.c. In particular,
StringList.toC does not account for the extra memory that should be
allocated for the "sentinel" entry. And, when using the "slice trick" to
create a slice that can address C memory, the unsafe.Pointer conversion
should be on a C.libxl_string_list, not *C.libxl_string_list.
Fix these problems by (1) allocating an extra slot in the slice used to
address the C memory, and explicity set the last entry to nil so the C
memory will be zeroed out, and (2) dereferencing csl in the
unsafe.Pointer conversion.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Re-generate code to reflect changes to libxl_types.idl from the
following commits:
0570d7f276 x86/msr: introduce an option for compatible MSR behavior selection
7e5cffcd1e viridian: allow vCPU hotplug for Windows VMs
9835246710 viridian: remove implicit limit of 64 VPs per partition
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
There is a standard format for generated Go code header comments, as set
by [1]. Modify gengotypes.py to follow this standard, and use the
additional
// source: <IDL file basename>
convention used by protoc-gen-go.
This change is motivated by the fact that since 41aea82de2, the comment
would include the absolute path to libxl_types.idl, therefore creating
unintended diffs when generating code across different machines. This
approach fixes that problem.
[1] https://github.com/golang/go/issues/13560
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Currently, in order to 'import idl' in gengotypes.py, we derive the path
of the libxl source directory from the XEN_ROOT environment variable, and
append that to sys.path so python can see idl.py. Since the the recent move of
libxl to tools/libs/light, this hard coding breaks the build.
Instead, check for the environment variable LIBXL_SRC_DIR, but move this
check to a try-except block (with empty except). This simply makes the
real error more visible, and does not strictly require that
LIBXL_SRC_DIR is used. Finally, update the Makefile to set LIBXL_SRC_DIR
rather than XEN_ROOT when calling gengotypes.py.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Before python 2.7, str.format() calls required that the format fields
were explicitly enumerated, e.g.:
'{0} {1}'.format(foo, bar)
vs.
'{} {}'.format(foo, bar)
Currently, gengotypes.py uses the latter pattern everywhere, which means
the Go bindings do not build on python 2.6. Use the 2.6 syntax for
format() in order to support python 2.6 for now.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Wei Liu <wl@xen.org>
The xenlight_golang_union_from_C function iterates over a dict to
construct a switch statement that marshals a C keyed union into a Go
type. Because python does not guarantee dict ordering across all
versions, this can result in the switch statement being generated in a
different order depending on the version of python used. For example,
running gengotypes.py with python2.7 and python3.6 will yield different
orderings.
Iterate over sorted(cases.items()) rather than cases.items() to fix
this.
This patch changes the ordering from what was previously checked-in, but
running gengotypes.py with different versions of python will now yield
the same result.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
Currently, no minimum go compiler version is required by the configure
scripts. However, the go bindings actually will not build with some
older versions of go. Add a check for a minimum go version of 1.11.1 in
accordance with tools/golang/xenlight/go.mod.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Tested-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>
When generating documentation, pkg.go.dev and godoc.org assume a comment
that immediately precedes the package declaration is a "package
comment", and should be shown in the documentation. Add an empty line
after the DO NOT EDIT comment in generated files to prevent these
comments from appearing as "package comments."
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Add a README and package comment giving a brief overview of the package.
These also help pkg.go.dev generate better documentation.
Also, add a copy of the LGPL (the same license used by libxl) to
tools/golang/xenlight. This is required for the package to be shown
on pkg.go.dev and added to the default module proxy, proxy.golang.org.
Finally, add an entry for the xenlight package to SUPPORT.md.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Initialize the xenlight Go module using the xenbits git-http URL,
xenbits.xenproject.org/git-http/xen.git/tools/golang/xenlight.
Also simplify the build Make target by using `go build` instead of `go
install`, and do not set GOPATH here because it is now unnecessary.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Commit df669de074 un-tracked the generated
Go code, but it was decided that we actually keep the generated code
in-tree.
Undo the changes to ignore the generated code, and re-generate it.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Many exported functions in xenlight require a domid as an argument. Make
it easier for package users to use these functions by adding wrappers
for the libxl utility functions libxl_name_to_domid and
libxl_domid_to_name.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
The generated go files were tracked temporarily while the initial
implementation of gengotypes.py was in progress. They can now be removed
and ignored by git and hg.
While here, make sure generated files are removed by make clean.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Wei Liu <wl@xen.org>
By default, if the go compiler is found by the configure script, build
the golang tools. If the compiler is not found, and --enable-golang was
not explicitly set, do not build to the golang tools.
The corresponding make variable is CONFIG_GOLANG. Remove CONFIG_GOLANG
from tools/Rules.mk since the variable is now set by configure in
config/Tools.mk.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Add DeviceUsbdevAdd and DeviceUsbdevRemove as wrappers for
libxl_device_usbdev_add and libxl_device_usbdev_remove.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Add DevicePciAdd and DevicePciRemove as wrappers for
libxl_device_pci_add and libxl_device_pci remove.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Add DeviceNicAdd and DeviceNicRemove as wrappers for
libxl_device_nic_add and libxl_device_nic_remove.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Generate constructors for generated Go types. Call libxl_<type>_init so
the Go type can be properly initialized.
If a type has a keyed union field, add a parameter to the function
signature to set the key variable, and call the init function for the
keyed union.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Since the C union cannot be directly populated, populate the fields of the
corresponding C struct defined in the cgo preamble, and then copy that
struct as bytes into the byte slice that Go uses as the union.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Implement conversions for basic types such as strings and integer
types in toC functions.
Modify function signatures of toC implementations for builtin
types to be consistent with the signature of the generated toC
functions.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
A previous commit that removed Context.CheckOpen revealed
an ineffectual assignent to err in Context.Cpupoolinfo, as
there is no error return type.
Since it appears that the intent is to return an error here,
add an error return value to the function signature.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Remove the exported global context variable, 'Ctx.' Generally, it is
better to not export global variables for use through a Go package.
However, there are some exceptions that can be found in the standard
library.
Add a NewContext function instead, and remove the Open, IsOpen, and
CheckOpen functions as a result.
Also, comment-out an ineffectual assignment to 'err' inside the function
Context.CpupoolInfo so that compilation does not fail.
Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
Nick Rosbrook