contrib/qemu: Import qemu block source code

This qemu block format source code and its minimal
dependency files will be used in the next patch to implement
a qemu-block format translator.

Change-Id: Ic87638972f7ea9b3df84d7a0539512a250c11c1c
BUG: 986775
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5366
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/contrib/qemu/qobject/json-streamer.c b/contrib/qemu/qobject/json-streamer.c
new file mode 100644
index 00000000000..1b2f9b1d107
--- /dev/null
+++ b/contrib/qemu/qobject/json-streamer.c
@@ -0,0 +1,122 @@
+/*
+ * 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.
+ *
+ */
+
+#include "qapi/qmp/qlist.h"
+#include "qapi/qmp/qint.h"
+#include "qapi/qmp/qdict.h"
+#include "qemu-common.h"
+#include "qapi/qmp/json-lexer.h"
+#include "qapi/qmp/json-streamer.h"
+
+#define MAX_TOKEN_SIZE (64ULL << 20)
+#define MAX_NESTING (1ULL << 10)
+
+static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y)
+{
+    JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
+    QDict *dict;
+
+    if (type == JSON_OPERATOR) {
+        switch (qstring_get_str(token)[0]) {
+        case '{':
+            parser->brace_count++;
+            break;
+        case '}':
+            parser->brace_count--;
+            break;
+        case '[':
+            parser->bracket_count++;
+            break;
+        case ']':
+            parser->bracket_count--;
+            break;
+        default:
+            break;
+        }
+    }
+
+    dict = qdict_new();
+    qdict_put(dict, "type", qint_from_int(type));
+    QINCREF(token);
+    qdict_put(dict, "token", token);
+    qdict_put(dict, "x", qint_from_int(x));
+    qdict_put(dict, "y", qint_from_int(y));
+
+    parser->token_size += token->length;
+
+    qlist_append(parser->tokens, dict);
+
+    if (type == JSON_ERROR) {
+        goto out_emit_bad;
+    } else if (parser->brace_count < 0 ||
+        parser->bracket_count < 0 ||
+        (parser->brace_count == 0 &&
+         parser->bracket_count == 0)) {
+        goto out_emit;
+    } else if (parser->token_size > MAX_TOKEN_SIZE ||
+               parser->bracket_count > MAX_NESTING ||
+               parser->brace_count > MAX_NESTING) {
+        /* Security consideration, we limit total memory allocated per object
+         * and the maximum recursion depth that a message can force.
+         */
+        goto out_emit;
+    }
+
+    return;
+
+out_emit_bad:
+    /* clear out token list and tell the parser to emit and error
+     * indication by passing it a NULL list
+     */
+    QDECREF(parser->tokens);
+    parser->tokens = NULL;
+out_emit:
+    /* send current list of tokens to parser and reset tokenizer */
+    parser->brace_count = 0;
+    parser->bracket_count = 0;
+    parser->emit(parser, parser->tokens);
+    if (parser->tokens) {
+        QDECREF(parser->tokens);
+    }
+    parser->tokens = qlist_new();
+    parser->token_size = 0;
+}
+
+void json_message_parser_init(JSONMessageParser *parser,
+                              void (*func)(JSONMessageParser *, QList *))
+{
+    parser->emit = func;
+    parser->brace_count = 0;
+    parser->bracket_count = 0;
+    parser->tokens = qlist_new();
+    parser->token_size = 0;
+
+    json_lexer_init(&parser->lexer, json_message_process_token);
+}
+
+int json_message_parser_feed(JSONMessageParser *parser,
+                             const char *buffer, size_t size)
+{
+    return json_lexer_feed(&parser->lexer, buffer, size);
+}
+
+int json_message_parser_flush(JSONMessageParser *parser)
+{
+    return json_lexer_flush(&parser->lexer);
+}
+
+void json_message_parser_destroy(JSONMessageParser *parser)
+{
+    json_lexer_destroy(&parser->lexer);
+    QDECREF(parser->tokens);
+}