Commit cc9821fa authored by Peter Maydell's avatar Peter Maydell
Browse files

Merge remote-tracking branch 'remotes/armbru/tags/pull-qobject-2018-08-24' into staging 



QObject patches for 2018-08-24

# gpg: Signature made Fri 24 Aug 2018 20:28:53 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qobject-2018-08-24: (58 commits)
  json: Update references to RFC 7159 to RFC 8259
  json: Support %% in JSON strings when interpolating
  json: Improve safety of qobject_from_jsonf_nofail() & friends
  json: Keep interpolation state in JSONParserContext
  tests/drive_del-test: Fix harmless JSON interpolation bug
  json: Clean up headers
  qobject: Drop superfluous includes of qemu-common.h
  json: Make JSONToken opaque outside json-parser.c
  json: Unbox tokens queue in JSONMessageParser
  json: Streamline json_message_process_token()
  json: Enforce token count and size limits more tightly
  qjson: Have qobject_from_json() & friends reject empty and blank
  json: Assert json_parser_parse() consumes all tokens on success
  json: Fix streamer not to ignore trailing unterminated structures
  json: Fix latent parser aborts at end of input
  qjson: Fix qobject_from_json() & friends for multiple values
  json: Improve names of lexer states related to numbers
  json: Replace %I64d, %I64u by %PRId64, %PRIu64
  json: Leave rejecting invalid interpolation to parser
  json: Pass lexical errors and limit violations to callback
  ...

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents e2e6fa67 37aded92

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -1715,6 +1715,7 @@ F: monitor.c 
F: docs/devel/*qmp-*

F: scripts/qmp/

F: tests/qmp-test.c

F: tests/qmp-cmd-test.c

T: git git://repo.or.cz/qemu/armbru.git qapi-next



qtest

block.c

+0 −5
Original line number Diff line number Diff line
@@ -1478,11 +1478,6 @@ static QDict *parse_json_filename(const char *filename, Error **errp) 


    options_obj = qobject_from_json(filename, errp);

    if (!options_obj) {

        /* Work around qobject_from_json() lossage TODO fix that */

        if (errp && !*errp) {

            error_setg(errp, "Could not parse the JSON options");

            return NULL;

        }

        error_prepend(errp, "Could not parse the JSON options: ");

        return NULL;

    }

docs/interop/qmp-spec.txt

+28 −14
Original line number Diff line number Diff line
@@ -20,9 +20,9 @@ operating system. 
2. Protocol Specification

=========================



This section details the protocol format. For the purpose of this document

"Client" is any application which is using QMP to communicate with QEMU and

"Server" is QEMU itself.

This section details the protocol format. For the purpose of this

document, "Server" is either QEMU or the QEMU Guest Agent, and

"Client" is any application communicating with it via QMP.



JSON data structures, when mentioned in this document, are always in the

following format:
@@ -34,9 +34,8 @@ by the JSON standard: 


http://www.ietf.org/rfc/rfc7159.txt



The protocol is always encoded in UTF-8 except for synchronization

bytes (documented below); although thanks to json-string escape

sequences, the server will reply using only the strict ASCII subset.

The server expects its input to be encoded in UTF-8, and sends its

output encoded in ASCII.



For convenience, json-object members mentioned in this document will

be in a certain order. However, in real protocol usage they can be in
@@ -215,16 +214,31 @@ Some events are rate-limited to at most one per second. If additional 
dropped, and the last one is delayed.  "Similar" normally means same

event type.  See qmp-events.txt for details.



2.6 QGA Synchronization

2.6 Forcing the JSON parser into known-good state

-------------------------------------------------



Incomplete or invalid input can leave the server's JSON parser in a

state where it can't parse additional commands.  To get it back into

known-good state, the client should provoke a lexical error.



The cleanest way to do that is sending an ASCII control character

other than '\t' (horizontal tab), '\r' (carriage return), or '\n' (new

line).



Sadly, older versions of QEMU can fail to flag this as an error.  If a

client needs to deal with them, it should send a 0xFF byte.



2.7 QGA Synchronization

-----------------------



When using QGA, an additional synchronization feature is built into

the protocol.  If the Client sends a raw 0xFF sentinel byte (not valid

JSON), then the Server will reset its state and discard all pending

data prior to the sentinel.  Conversely, if the Client makes use of

the 'guest-sync-delimited' command, the Server will send a raw 0xFF

sentinel byte prior to its response, to aid the Client in discarding

any data prior to the sentinel.

When a client connects to QGA over a transport lacking proper

connection semantics such as virtio-serial, QGA may have read partial

input from a previous client.  The client needs to force QGA's parser

into known-good state using the previous section's technique.

Moreover, the client may receive output a previous client didn't read.

To help with skipping that output, QGA provides the

'guest-sync-delimited' command.  Refer to its documentation for

details.





3. QMP Examples

include/qapi/qmp/json-parser.h

+30 −6
Original line number Diff line number Diff line
@@ -11,12 +11,36 @@ 
 *

 */



#ifndef QEMU_JSON_PARSER_H

#define QEMU_JSON_PARSER_H

#ifndef QAPI_QMP_JSON_PARSER_H

#define QAPI_QMP_JSON_PARSER_H



#include "qemu-common.h"

typedef struct JSONLexer {

    int start_state, state;

    GString *token;

    int x, y;

} JSONLexer;



QObject *json_parser_parse(GQueue *tokens, va_list *ap);

QObject *json_parser_parse_err(GQueue *tokens, va_list *ap, Error **errp);

typedef struct JSONMessageParser {

    void (*emit)(void *opaque, QObject *json, Error *err);

    void *opaque;

    va_list *ap;

    JSONLexer lexer;

    int brace_count;

    int bracket_count;

    GQueue tokens;

    uint64_t token_size;

} JSONMessageParser;



void json_message_parser_init(JSONMessageParser *parser,

                              void (*emit)(void *opaque, QObject *json,

                                           Error *err),

                              void *opaque, va_list *ap);



void json_message_parser_feed(JSONMessageParser *parser,

                             const char *buffer, size_t size);



void json_message_parser_flush(JSONMessageParser *parser);



void json_message_parser_destroy(JSONMessageParser *parser);



#endif

include/qapi/qmp/json-streamer.h

deleted100644 → 0
+0 −46
Original line number Diff line number Diff line 
/*

 * JSON streaming support

 *

 * Copyright IBM, Corp. 2009

 *

 * Authors:

 *  Anthony Liguori   <aliguori@us.ibm.com>

 *

 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.

 * See the COPYING.LIB file in the top-level directory.

 *

 */



#ifndef QEMU_JSON_STREAMER_H

#define QEMU_JSON_STREAMER_H



#include "qapi/qmp/json-lexer.h"



typedef struct JSONToken {

    int type;

    int x;

    int y;

    char str[];

} JSONToken;



typedef struct JSONMessageParser

{

    void (*emit)(struct JSONMessageParser *parser, GQueue *tokens);

    JSONLexer lexer;

    int brace_count;

    int bracket_count;

    GQueue *tokens;

    uint64_t token_size;

} JSONMessageParser;



void json_message_parser_init(JSONMessageParser *parser,

                              void (*func)(JSONMessageParser *, GQueue *));



int json_message_parser_feed(JSONMessageParser *parser,

                             const char *buffer, size_t size);



int json_message_parser_flush(JSONMessageParser *parser);



void json_message_parser_destroy(JSONMessageParser *parser);



#endif