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QMP: Input support

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The JSON stream parser is used to do QMP input. When there
are enough characters to be parsed it calls Monitor's
handle_qmp_command() function to handle the input.

This function's job is to check if the input is correct and
call the appropriate handler. In other words, it does for QMP
what handle_user_command() does for the user protocol.

This means that handle_qmp_command() also has to parse the
(ugly) "args_type" format to able to get the arguments names
and types expected by the handler.

The format to input commands in QMP is as follows:

{ "execute": json-string,
  "id": json-value, "arguments": json-object }

Please, note that this commit also adds "id" support.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Luiz Capitulino 2009-11-26 22:59:01 -02:00 committed by Anthony Liguori
parent 956f1a0d83
commit 5fa737a479
1 changed files with 240 additions and 1 deletions
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241
monitor.c
View File

@ -48,9 +48,12 @@
#include "qint.h"
#include "qlist.h"
#include "qdict.h"
#include "qbool.h"
#include "qstring.h"
#include "qerror.h"
#include "qjson.h"
#include "json-streamer.h"
#include "json-parser.h"
//#define DEBUG
//#define DEBUG_COMPLETION
@ -93,6 +96,11 @@ struct mon_fd_t {
QLIST_ENTRY(mon_fd_t) next;
};
typedef struct MonitorControl {
QObject *id;
JSONMessageParser parser;
} MonitorControl;
struct Monitor {
CharDriverState *chr;
int mux_out;
@ -102,6 +110,7 @@ struct Monitor {
uint8_t outbuf[1024];
int outbuf_index;
ReadLineState *rs;
MonitorControl *mc;
CPUState *mon_cpu;
BlockDriverCompletionFunc *password_completion_cb;
void *password_opaque;
@ -289,6 +298,11 @@ static void monitor_protocol_emitter(Monitor *mon, QObject *data)
mon->error = NULL;
}
if (mon->mc->id) {
qdict_put_obj(qmp, "id", mon->mc->id);
mon->mc->id = NULL;
}
monitor_json_emitter(mon, QOBJECT(qmp));
QDECREF(qmp);
}
@ -3558,6 +3572,228 @@ static int monitor_can_read(void *opaque)
return (mon->suspend_cnt == 0) ? 128 : 0;
}
typedef struct CmdArgs {
QString *name;
int type;
int flag;
int optional;
} CmdArgs;
static int check_opt(const CmdArgs *cmd_args, const char *name, QDict *args)
{
if (!cmd_args->optional) {
qemu_error_new(QERR_MISSING_PARAMETER, name);
return -1;
}
if (cmd_args->type == '-') {
/* handlers expect a value, they need to be changed */
qdict_put(args, name, qint_from_int(0));
}
return 0;
}
static int check_arg(const CmdArgs *cmd_args, QDict *args)
{
QObject *value;
const char *name;
name = qstring_get_str(cmd_args->name);
if (!args) {
return check_opt(cmd_args, name, args);
}
value = qdict_get(args, name);
if (!value) {
return check_opt(cmd_args, name, args);
}
switch (cmd_args->type) {
case 'F':
case 'B':
case 's':
if (qobject_type(value) != QTYPE_QSTRING) {
qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "string");
return -1;
}
break;
case '/': {
int i;
const char *keys[] = { "count", "format", "size", NULL };
for (i = 0; keys[i]; i++) {
QObject *obj = qdict_get(args, keys[i]);
if (!obj) {
qemu_error_new(QERR_MISSING_PARAMETER, name);
return -1;
}
if (qobject_type(obj) != QTYPE_QINT) {
qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "int");
return -1;
}
}
break;
}
case 'i':
case 'l':
if (qobject_type(value) != QTYPE_QINT) {
qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "int");
return -1;
}
break;
case '-':
if (qobject_type(value) != QTYPE_QINT &&
qobject_type(value) != QTYPE_QBOOL) {
qemu_error_new(QERR_INVALID_PARAMETER_TYPE, name, "bool");
return -1;
}
if (qobject_type(value) == QTYPE_QBOOL) {
/* handlers expect a QInt, they need to be changed */
qdict_put(args, name,
qint_from_int(qbool_get_int(qobject_to_qbool(value))));
}
break;
default:
/* impossible */
abort();
}
return 0;
}
static void cmd_args_init(CmdArgs *cmd_args)
{
cmd_args->name = qstring_new();
cmd_args->type = cmd_args->flag = cmd_args->optional = 0;
}
/*
* This is not trivial, we have to parse Monitor command's argument
* type syntax to be able to check the arguments provided by clients.
*
* In the near future we will be using an array for that and will be
* able to drop all this parsing...
*/
static int monitor_check_qmp_args(const mon_cmd_t *cmd, QDict *args)
{
int err;
const char *p;
CmdArgs cmd_args;
if (cmd->args_type == '\0') {
return (qdict_size(args) == 0 ? 0 : -1);
}
err = 0;
cmd_args_init(&cmd_args);
for (p = cmd->args_type;; p++) {
if (*p == ':') {
cmd_args.type = *++p;
p++;
if (cmd_args.type == '-') {
cmd_args.flag = *p++;
cmd_args.optional = 1;
} else if (*p == '?') {
cmd_args.optional = 1;
p++;
}
assert(*p == ',' || *p == '\0');
err = check_arg(&cmd_args, args);
QDECREF(cmd_args.name);
cmd_args_init(&cmd_args);
if (err < 0) {
break;
}
} else {
qstring_append_chr(cmd_args.name, *p);
}
if (*p == '\0') {
break;
}
}
QDECREF(cmd_args.name);
return err;
}
static void handle_qmp_command(JSONMessageParser *parser, QList *tokens)
{
int err;
QObject *obj;
QDict *input, *args;
const char *cmd_name;
const mon_cmd_t *cmd;
Monitor *mon = cur_mon;
args = NULL;
qemu_errors_to_mon(mon);
obj = json_parser_parse(tokens, NULL);
if (!obj) {
// FIXME: should be triggered in json_parser_parse()
qemu_error_new(QERR_JSON_PARSING);
goto err_out;
} else if (qobject_type(obj) != QTYPE_QDICT) {
qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "object");
qobject_decref(obj);
goto err_out;
}
input = qobject_to_qdict(obj);
mon->mc->id = qdict_get(input, "id");
qobject_incref(mon->mc->id);
obj = qdict_get(input, "execute");
if (!obj) {
qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "execute");
goto err_input;
} else if (qobject_type(obj) != QTYPE_QSTRING) {
qemu_error_new(QERR_QMP_BAD_INPUT_OBJECT, "string");
goto err_input;
}
cmd_name = qstring_get_str(qobject_to_qstring(obj));
cmd = monitor_find_command(cmd_name);
if (!cmd) {
qemu_error_new(QERR_COMMAND_NOT_FOUND, cmd_name);
goto err_input;
}
obj = qdict_get(input, "arguments");
if (!obj) {
args = qdict_new();
} else {
args = qobject_to_qdict(obj);
QINCREF(args);
}
QDECREF(input);
err = monitor_check_qmp_args(cmd, args);
if (err < 0) {
goto err_out;
}
monitor_call_handler(mon, cmd, args);
goto out;
err_input:
QDECREF(input);
err_out:
monitor_protocol_emitter(mon, NULL);
out:
QDECREF(args);
qemu_errors_to_previous();
}
/**
* monitor_control_read(): Read and handle QMP input
*/
@ -3567,7 +3803,7 @@ static void monitor_control_read(void *opaque, const uint8_t *buf, int size)
cur_mon = opaque;
// TODO: read QMP input
json_message_parser_feed(&cur_mon->mc->parser, (const char *) buf, size);
cur_mon = old_mon;
}
@ -3624,6 +3860,8 @@ static void monitor_control_event(void *opaque, int event)
QObject *data;
Monitor *mon = opaque;
json_message_parser_init(&mon->mc->parser, handle_qmp_command);
data = qobject_from_jsonf("{ 'QMP': { 'capabilities': [] } }");
assert(data != NULL);
@ -3719,6 +3957,7 @@ void monitor_init(CharDriverState *chr, int flags)
}
if (monitor_ctrl_mode(mon)) {
mon->mc = qemu_mallocz(sizeof(MonitorControl));
/* Control mode requires special handlers */
qemu_chr_add_handlers(chr, monitor_can_read, monitor_control_read,
monitor_control_event, mon);