adding logic to free buffers allocated for POST processing when connection dies without completion

src/mint/taler-mint-httpd.c

@@ -73,35 +73,29 @@ static uint16_t serve_port;
 
 
 /**
- * Convert a string representing an EdDSA signature to an EdDSA
- * signature.
+ * Function called whenever MHD is done with a request.  If the
+ * request was a POST, we may have stored a `struct Buffer *` in the
+ * @a con_cls that might still need to be cleaned up.  Call the
+ * respective function to free the memory.
  *
- * FIXME: this should be in GNUnet.
- * FIXME: why? this code is dead, even here!
- *
- * @param enc encoded EdDSA signature
- * @param enclen number of bytes in @a enc (without 0-terminator)
- * @param pub where to store the EdDSA signature
- * @return #GNUNET_OK on success
+ * @param cls client-defined closure
+ * @param connection connection handle
+ * @param con_cls value as set by the last call to
+ *        the #MHD_AccessHandlerCallback
+ * @param toe reason for request termination
+ * @see #MHD_OPTION_NOTIFY_COMPLETED
+ * @ingroup request
  */
-int
-TALER_eddsa_signature_from_string (const char *enc,
-                                   size_t enclen,
-                                   struct GNUNET_CRYPTO_EddsaSignature *sig)
+static void
+handle_mhd_completion_callback (void *cls,
+                                struct MHD_Connection *connection,
+                                void **con_cls,
+                                enum MHD_RequestTerminationCode toe)
 {
-  size_t keylen = (sizeof (struct GNUNET_CRYPTO_EddsaSignature)) * 8;
-
-  if (keylen % 5 > 0)
-    keylen += 5 - keylen % 5;
-  keylen /= 5;
-  if (enclen != keylen)
-    return GNUNET_SYSERR;
-
-  if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen,
-						  sig,
-						  sizeof (struct GNUNET_CRYPTO_EddsaSignature)))
-    return GNUNET_SYSERR;
-  return GNUNET_OK;
+  if (NULL == *con_cls)
+    return;
+  TALER_MINT_parse_post_cleanup_callback (*con_cls);
+  *con_cls = NULL;
 }
 
 
@@ -225,7 +219,6 @@ handle_mhd_request (void *cls,
 }
 
 
-
 /**
  * Load configuration parameters for the mint
  * server into the corresponding global variables.
@@ -359,6 +352,7 @@ main (int argc, char *const *argv)
                                serve_port,
                                NULL, NULL,
                                &handle_mhd_request, NULL,
+                               MHD_OPTION_NOTIFY_COMPLETED, &handle_mhd_completion_callback,
                                MHD_OPTION_END);
 
   if (NULL == mydaemon)

src/mint/taler-mint-httpd_deposit.c

@@ -88,7 +88,7 @@ TALER_MINT_handler_deposit (struct RequestHandler *rh,
   PGconn *db_conn;
   int res;
 
-  res = process_post_json (connection,
+  res = TALER_MINT_parse_post_json (connection,
                            connection_cls,
                            upload_data, upload_data_size,
                            &json);

src/mint/taler-mint-httpd_parsing.c

@@ -156,11 +156,11 @@ buffer_append (struct Buffer *buf,
  *    GNUNET_SYSERR on internal error
  */
 int
-process_post_json (struct MHD_Connection *connection,
-                   void **con_cls,
-                   const char *upload_data,
-                   size_t *upload_data_size,
-                   json_t **json)
+TALER_MINT_parse_post_json (struct MHD_Connection *connection,
+                            void **con_cls,
+                            const char *upload_data,
+                            size_t *upload_data_size,
+                            json_t **json)
 {
   struct Buffer *r = *con_cls;
 
@@ -228,6 +228,23 @@ process_post_json (struct MHD_Connection *connection,
 }
 
 
+/**
+ * Function called whenever we are done with a request
+ * to clean up our state.
+ *
+ * @param con_cls value as it was left by
+ *        #TALER_MINT_parse_post_json(), to be cleaned up
+ */
+void
+TALER_MINT_parse_post_cleanup_callback (void *con_cls)
+{
+  struct Buffer *r = con_cls;
+
+  if (NULL != r)
+    buffer_deinit (r);
+}
+
+
 /**
  * Navigate through a JSON tree.
  *
@@ -451,3 +468,5 @@ TALER_MINT_mhd_request_arg_data (struct MHD_Connection *connection,
       ? GNUNET_SYSERR : GNUNET_NO;
   return GNUNET_OK;
 }
+
+/* end of taler-mint-httpd_parsing.c */

src/mint/taler-mint-httpd_parsing.h

@@ -68,25 +68,45 @@ enum
 
 
 /**
- * Process a POST request containing a JSON object.
+ * Process a POST request containing a JSON object.  This
+ * function realizes an MHD POST processor that will
+ * (incrementally) process JSON data uploaded to the HTTP
+ * server.  It will store the required state in the
+ * "connection_cls", which must be cleaned up using
+ * #TALER_MINT_parse_post_cleanup_callback().
  *
  * @param connection the MHD connection
- * @param con_cs the closure (contains a 'struct Buffer *')
+ * @param con_cs the closure (points to a `struct Buffer *`)
  * @param upload_data the POST data
- * @param upload_data_size the POST data size
+ * @param upload_data_size number of bytes in @a upload_data
  * @param json the JSON object for a completed request
  *
  * @returns
- *    GNUNET_YES if json object was parsed
+ *    GNUNET_YES if json object was parsed or at least
+ *               may be parsed in the future (call again)
  *    GNUNET_NO is request incomplete or invalid
+ *               (error message was generated)
  *    GNUNET_SYSERR on internal error
+ *               (we could not even queue an error message,
+ *                close HTTP session with MHD_NO)
  */
 int
-process_post_json (struct MHD_Connection *connection,
-                   void **con_cls,
-                   const char *upload_data,
-                   size_t *upload_data_size,
-                   json_t **json);
+TALER_MINT_parse_post_json (struct MHD_Connection *connection,
+                            void **con_cls,
+                            const char *upload_data,
+                            size_t *upload_data_size,
+                            json_t **json);
+
+
+/**
+ * Function called whenever we are done with a request
+ * to clean up our state.
+ *
+ * @param con_cls value as it was left by
+ *        #TALER_MINT_parse_post_json(), to be cleaned up
+ */
+void
+TALER_MINT_parse_post_cleanup_callback (void *con_cls);
 
 
 /**

src/mint/taler-mint-httpd_refresh.c

@@ -606,7 +606,7 @@ TALER_MINT_handler_refresh_melt (struct RequestHandler *rh,
   struct GNUNET_HashContext *hash_context;
   struct GNUNET_HashCode melt_hash;
 
-  res = process_post_json (connection,
+  res = TALER_MINT_parse_post_json (connection,
                            connection_cls,
                            upload_data,
                            upload_data_size, &root);
@@ -823,7 +823,7 @@ TALER_MINT_handler_refresh_commit (struct RequestHandler *rh,
   struct GNUNET_HashContext *hash_context;
   json_t *root;
 
-  res = process_post_json (connection,
+  res = TALER_MINT_parse_post_json (connection,
                            connection_cls,
                            upload_data,
                            upload_data_size, &root);
@@ -1159,7 +1159,7 @@ TALER_MINT_handler_refresh_reveal (struct RequestHandler *rh,
   int j;
   json_t *root;
 
-  res = process_post_json (connection,
+  res = TALER_MINT_parse_post_json (connection,
                            connection_cls,
                            upload_data, upload_data_size,
                            &root);

src/mint/taler-mint-httpd_responses.h

@@ -90,4 +90,6 @@ TALER_MINT_reply_arg_missing (struct MHD_Connection *connection,
                               const char *param_name);
 
 
+
+
 #endif