X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=json-lexer.c;h=c21338f66db75814e504ca86bf29c7b7487c3903;hb=49e40b6627ea92c246b3903d171c88480b782512;hp=fe5a060d4dd1c5cad3fa30ec4cc349f7af5c2a46;hpb=325601b47b64b33cbe237508df2037e195795497;p=qemu.git

diff --git a/json-lexer.c b/json-lexer.c
index fe5a060d4..c21338f66 100644
--- a/json-lexer.c
+++ b/json-lexer.c
@@ -105,7 +105,8 @@ static const uint8_t json_lexer[][256] =  {
         ['u'] = IN_DQ_UCODE0,
     },
     [IN_DQ_STRING] = {
-        [1 ... 0xFF] = IN_DQ_STRING,
+        [1 ... 0xBF] = IN_DQ_STRING,
+        [0xC2 ... 0xF4] = IN_DQ_STRING,
         ['\\'] = IN_DQ_STRING_ESCAPE,
         ['"'] = JSON_STRING,
     },
@@ -144,7 +145,8 @@ static const uint8_t json_lexer[][256] =  {
         ['u'] = IN_SQ_UCODE0,
     },
     [IN_SQ_STRING] = {
-        [1 ... 0xFF] = IN_SQ_STRING,
+        [1 ... 0xBF] = IN_SQ_STRING,
+        [0xC2 ... 0xF4] = IN_SQ_STRING,
         ['\\'] = IN_SQ_STRING_ESCAPE,
         ['\''] = JSON_STRING,
     },
@@ -274,7 +276,7 @@ void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func)
     lexer->x = lexer->y = 0;
 }
 
-static int json_lexer_feed_char(JSONLexer *lexer, char ch)
+static int json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
 {
     int char_consumed, new_state;
 
@@ -305,12 +307,30 @@ static int json_lexer_feed_char(JSONLexer *lexer, char ch)
             new_state = IN_START;
             break;
         case IN_ERROR:
-            return -EINVAL;
+            /* XXX: To avoid having previous bad input leaving the parser in an
+             * unresponsive state where we consume unpredictable amounts of
+             * subsequent "good" input, percolate this error state up to the
+             * tokenizer/parser by forcing a NULL object to be emitted, then
+             * reset state.
+             *
+             * Also note that this handling is required for reliable channel
+             * negotiation between QMP and the guest agent, since chr(0xFF)
+             * is placed at the beginning of certain events to ensure proper
+             * delivery when the channel is in an unknown state. chr(0xFF) is
+             * never a valid ASCII/UTF-8 sequence, so this should reliably
+             * induce an error/flush state.
+             */
+            lexer->emit(lexer, lexer->token, JSON_ERROR, lexer->x, lexer->y);
+            QDECREF(lexer->token);
+            lexer->token = qstring_new();
+            new_state = IN_START;
+            lexer->state = new_state;
+            return 0;
         default:
             break;
         }
         lexer->state = new_state;
-    } while (!char_consumed);
+    } while (!char_consumed && !flush);
 
     /* Do not let a single token grow to an arbitrarily large size,
      * this is a security consideration.
@@ -332,7 +352,7 @@ int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size)
     for (i = 0; i < size; i++) {
         int err;
 
-        err = json_lexer_feed_char(lexer, buffer[i]);
+        err = json_lexer_feed_char(lexer, buffer[i], false);
         if (err < 0) {
             return err;
         }
@@ -343,7 +363,7 @@ int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size)
 
 int json_lexer_flush(JSONLexer *lexer)
 {
-    return lexer->state == IN_START ? 0 : json_lexer_feed_char(lexer, 0);
+    return lexer->state == IN_START ? 0 : json_lexer_feed_char(lexer, 0, true);
 }
 
 void json_lexer_destroy(JSONLexer *lexer)