These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Version 2.0.0 or yajl changed API. It is fairly trivial for us to
cope with both APIs in libvirt, so adapt.
* configure.ac: Probe for yajl2 API
* src/util/json.c: Conditional support for yajl2 API
Problem:
"parser.head" is not NULL even if it's free'ed by "virJSONValueFree",
returning "parser.head" when "virJSONValueFromString" fails will cause
unexpected errors (libvirtd will crash sometimes), e.g.
In function "qemuMonitorJSONArbitraryCommand":
if (!(cmd = virJSONValueFromString(cmd_str)))
goto cleanup;
if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
goto cleanup;
......
cleanup:
virJSONValueFree(cmd);
It will continues to send command to monitor even if "virJSONValueFromString"
is failed, and more worse, it trys to free "cmd" again.
Crash example:
{"error":{"class":"QMPBadInputObject","desc":"Expected 'execute' in QMP input","data":{"expected":"execute"}}}
{"error":{"class":"QMPBadInputObject","desc":"Expected 'execute' in QMP input","data":{"expected":"execute"}}}
error: server closed connection:
error: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Connection refused
error: failed to connect to the hypervisor
This fix is to:
1) return NULL for failure of "virJSONValueFromString",
2) and it seems "virJSONValueFree" uses incorrect loop index for type
of "VIR_JSON_TYPE_OBJECT", fix it together.
* src/util/json.c
* src/util/json.c, src/util/json.h: Declare returned strings
to be const
* src/qemu/qemu_monitor.c: Wire up JSON mode for qemuMonitorGetPtyPaths
* src/qemu/qemu_monitor_json.c, src/qemu/qemu_monitor_json.h: Fix
const correctness. Add missing error message in the function
qemuMonitorJSONGetAllPCIAddresses. Add implementation of the
qemuMonitorGetPtyPaths function calling 'query-chardev'.
configure: yajl: no
CC libvirt_util_la-json.lo
util/json.c:32:27: error: yajl/yajl_gen.h: No such file or directory
util/json.c:33:29: error: yajl/yajl_parse.h: No such file or directory
* src/util/json.c: remove the includes if yajl not configured in
This introduces simple API for handling JSON data. There is
an internal data structure 'virJSONValuePtr' which stores a
arbitrary nested JSON value (number, string, array, object,
nul, etc). There are APIs for constructing/querying objects
and APIs for parsing/formatting string formatted JSON data.
This uses the YAJL library for parsing/formatting from
http://lloyd.github.com/yajl/
* src/util/json.h, src/util/json.c: Data structures and APIs
for representing JSON data, and parsing/formatting it
* configure.in: Add check for yajl library
* libvirt.spec.in: Add build requires for yajl
* src/Makefile.am: Add json.c/h
* src/libvirt_private.syms: Export JSON symbols to drivers
