fix(libacron): memory leak when received more than one frames

API:CHANGE

1 files changed, 21 insertions, 2 deletions

diff --git a/client/libacron/net.c b/client/libacron/net.c
index b393475..55b10ce 100644
--- a/client/libacron/net.c
+++ b/client/libacron/net.c
@@ -62,6 +62,17 @@ static bool on_message_handler(struct wic_inst *inst,
     }
     /* TODO: Only parse when fin = true? */
     struct ac_result *res = &conn->result;
+    if (res->has_result) {
+	/* This flag will be cleared upon ac_receive using memset().
+	 * A positive flag indicates that on_message_handler was called
+	 * more than once before wic_parse returns. This could happen due
+	 * to more than one WebSocket frames were returned by a single read.
+	 * To prevent the new message from being overwritten (and thus causing
+	 * memory leaks), we return false here, making wic backlog the new message
+	 * until the next wic_parse. */
+	LOGD("Two or more frames arrived before wic_parse returns. Keeping the message.");
+	return false;
+    }
     int r;
     if ((r = deserialize(data, size, &res->obj))) {
         if (r == AC_E_SERIALIZER_CONTINUE) {
@@ -202,12 +213,20 @@ int ac_receive(void *connection,
 
     /* In case the deserializer does not run at all. */
     memset(&conn->result, 0, sizeof(struct ac_result));
-    for (pos = 0U; pos < len; pos += retval) {
-        retval = wic_parse(inst, &ptr[pos], len - pos);
+    if (!len) {
+	retval = wic_parse(inst, NULL, 0);
         if (wic_get_state(inst) == WIC_STATE_CLOSED) {
             LOGE("Connection closed.");
             return AC_E_NET;
         }
+    } else {
+        for (pos = 0U; pos < len; pos += retval) {
+            retval = wic_parse(inst, &ptr[pos], len - pos);
+            if (wic_get_state(inst) == WIC_STATE_CLOSED) {
+                LOGE("Connection closed.");
+                return AC_E_NET;
+            }
+        }
     }
 
     struct ac_result *res = &conn->result;