adding new GNUNET_HELPER_ API for communication with (SUID) helper binaries via stdin/stdout using standard GNUNET messages

1 files changed, 96 insertions, 0 deletions

diff --git a/src/include/gnunet_helper_lib.h b/src/include/gnunet_helper_lib.h
new file mode 100644
index 000000000..7115748fc
--- /dev/null
+++ b/src/include/gnunet_helper_lib.h
@@ -0,0 +1,96 @@
+/*
+     This file is part of GNUnet.
+     (C) 2011, 2012 Christian Grothoff
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file include/gnunet_helper_lib.h
+ * @brief API for dealing with (SUID) helper processes that communicate via GNUNET_MessageHeaders on stdin/stdout
+ * @author Philipp Toelke
+ * @author Christian Grothoff
+ */
+#ifndef GNUNET_HELPER_LIB_H
+#define GNUNET_HELPER_LIB_H
+
+#include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
+
+/**
+ * The handle to a helper process.
+ */
+struct GNUNET_HELPER_Handle;
+
+
+/**
+ * @brief Starts a helper and begins reading from it
+ *
+ * @param binary_name name of the binary to run
+ * @param binary_argv NULL-terminated list of arguments to give when starting the binary (this
+ *                    argument must not be modified by the client for
+ *                     the lifetime of the helper handle)
+ * @param cb function to call if we get messages from the helper
+ * @param cb_cls Closure for the callback
+ * @return the new Handle, NULL on error
+ */
+struct GNUNET_HELPER_Handle *
+GNUNET_HELPER_start (const char *binary_name,
+                     char *const binary_argv[],
+                     GNUNET_SERVER_MessageTokenizerCallback cb, void *cb_cls);
+
+
+/**
+ * @brief Kills the helper, closes the pipe and frees the handle
+ *
+ * @param h handle to helper to stop
+ */
+void
+GNUNET_HELPER_stop (struct GNUNET_HELPER_Handle *h);
+
+
+/**
+ * Continuation function.
+ * 
+ * @param cls closure
+ * @param result GNUNET_OK on success,
+ *               GNUNET_NO if helper process died
+ *               GNUNET_SYSERR during GNUNET_HELPER_stop
+ */
+typedef void (*GNUNET_HELPER_Continuation)(void *cls,
+                                           int result);
+
+
+/**
+ * Send an message to the helper.
+ *
+ * @param h helper to send message to
+ * @param msg message to send
+ * @param can_drop can the message be dropped if there is already one in the queue?
+ * @param cont continuation to run once the message is out
+ * @param cont_cls closure for 'cont'
+ * @return GNUNET_YES if the message will be sent
+ *         GNUNET_NO if the message was dropped
+ */
+int
+GNUNET_HELPER_send (struct GNUNET_HELPER_Handle *h, 
+                    const struct GNUNET_MessageHeader *msg,
+                    int can_drop,
+                    GNUNET_HELPER_Continuation cont,
+                    void *cont_cls);
+
+
+#endif /* end of include guard: GNUNET_HELPER_LIB_H */