1 files changed, 125 insertions, 0 deletions
diff --git a/src/qobject/json-streamer.c b/src/qobject/json-streamer.c
new file mode 100644
index 0000000..a4db4b8
--- /dev/null
+++ b/src/qobject/json-streamer.c
@@ -0,0 +1,125 @@
+/*
+ * 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 "qemu-common.h"
+#include "qapi/qmp/json-lexer.h"
+#include "qapi/qmp/json-streamer.h"
+
+#define MAX_TOKEN_SIZE (64ULL << 20)
+#define MAX_TOKEN_COUNT (2ULL << 20)
+#define MAX_NESTING (1ULL << 10)
+
+static void json_message_free_tokens(JSONMessageParser *parser)
+{
+    if (parser->tokens) {
+        g_queue_free(parser->tokens);
+        parser->tokens = NULL;
+    }
+}
+
+static void json_message_process_token(JSONLexer *lexer, GString *input,
+                                       JSONTokenType type, int x, int y)
+{
+    JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
+    JSONToken *token;
+
+    switch (type) {
+    case JSON_LCURLY:
+        parser->brace_count++;
+        break;
+    case JSON_RCURLY:
+        parser->brace_count--;
+        break;
+    case JSON_LSQUARE:
+        parser->bracket_count++;
+        break;
+    case JSON_RSQUARE:
+        parser->bracket_count--;
+        break;
+    default:
+        break;
+    }
+
+    token = g_malloc(sizeof(JSONToken) + input->len + 1);
+    token->type = type;
+    memcpy(token->str, input->str, input->len);
+    token->str[input->len] = 0;
+    token->x = x;
+    token->y = y;
+
+    parser->token_size += input->len;
+
+    g_queue_push_tail(parser->tokens, token);
+
+    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 ||
+               g_queue_get_length(parser->tokens) > MAX_TOKEN_COUNT ||
+               parser->bracket_count + 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_bad;
+    }
+
+    return;
+
+out_emit_bad:
+    /*
+     * Clear out token list and tell the parser to emit an error
+     * indication by passing it a NULL list
+     */
+    json_message_free_tokens(parser);
+out_emit:
+    /* send current list of tokens to parser and reset tokenizer */
+    parser->brace_count = 0;
+    parser->bracket_count = 0;
+    /* parser->emit takes ownership of parser->tokens.  */
+    parser->emit(parser, parser->tokens);
+    parser->tokens = g_queue_new();
+    parser->token_size = 0;
+}
+
+void json_message_parser_init(JSONMessageParser *parser,
+                              void (*func)(JSONMessageParser *, GQueue *))
+{
+    parser->emit = func;
+    parser->brace_count = 0;
+    parser->bracket_count = 0;
+    parser->tokens = g_queue_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);
+    json_message_free_tokens(parser);
+}