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authorChristian Grothoff <christian@grothoff.org>2016-07-30 16:51:51 +0000
committerChristian Grothoff <christian@grothoff.org>2016-07-30 16:51:51 +0000
commitb54a66f94d833dbe98eb0dd9e236a3d7bba3ce20 (patch)
tree7e9231517434bfd97a616a07eecdb932fdc691f8 /src/transport/transport_api_hello_get.c
parent811dc4cbbbcd87f4856ebd88fa3b777bb5fe1f89 (diff)
implementing new TRANSPORT_hello_get API
Diffstat (limited to 'src/transport/transport_api_hello_get.c')
-rw-r--r--src/transport/transport_api_hello_get.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/src/transport/transport_api_hello_get.c b/src/transport/transport_api_hello_get.c
new file mode 100644
index 000000000..9d4209e04
--- /dev/null
+++ b/src/transport/transport_api_hello_get.c
@@ -0,0 +1,275 @@
+/*
+ This file is part of GNUnet.
+ Copyright (C) 2009-2013, 2016 GNUnet e.V.
+
+ 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., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
+*/
+
+/**
+ * @file transport/transport_api_hello_get.c
+ * @brief library to obtain our HELLO from our transport service
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_transport_hello_service.h"
+#include "transport.h"
+
+
+/**
+ * Functions to call with this peer's HELLO.
+ */
+struct GNUNET_TRANSPORT_HelloGetHandle
+{
+
+ /**
+ * Our configuration.
+ */
+ const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+ /**
+ * Transport handle.
+ */
+ struct GNUNET_MQ_Handle *mq;
+
+ /**
+ * Callback to call once we got our HELLO.
+ */
+ GNUNET_TRANSPORT_HelloUpdateCallback rec;
+
+ /**
+ * Closure for @e rec.
+ */
+ void *rec_cls;
+
+ /**
+ * Task for calling the HelloUpdateCallback when we already have a HELLO
+ */
+ struct GNUNET_SCHEDULER_Task *notify_task;
+
+ /**
+ * ID of the task trying to reconnect to the service.
+ */
+ struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+ /**
+ * Delay until we try to reconnect.
+ */
+ struct GNUNET_TIME_Relative reconnect_delay;
+
+ /**
+ * Type of HELLOs client cares about.
+ */
+ enum GNUNET_ATS_Network_Type nt;
+};
+
+
+/**
+ * Function we use for checking incoming HELLO messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_Handle *`
+ * @param msg message received
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_hello (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_PeerIdentity me;
+
+ if (GNUNET_OK !=
+ GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
+ &me))
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Receiving (my own) HELLO message (%u bytes), I am `%s'.\n",
+ (unsigned int) ntohs (msg->size),
+ GNUNET_i2s (&me));
+ return GNUNET_OK;
+}
+
+
+/**
+ * Function we use for handling incoming HELLO messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_HelloGetHandle *`
+ * @param msg message received
+ */
+static void
+handle_hello (void *cls,
+ const struct GNUNET_MessageHeader *msg)
+{
+ struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+
+ ghh->rec (ghh->rec_cls,
+ msg);
+}
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param ghh transport service to reconnect
+ */
+static void
+schedule_reconnect (struct GNUNET_TRANSPORT_HelloGetHandle *ghh);
+
+
+/**
+ * Generic error handler, called with the appropriate
+ * error code and the same closure specified at the creation of
+ * the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure with the `struct GNUNET_TRANSPORT_Handle *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+ enum GNUNET_MQ_Error error)
+{
+ struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Error receiving from transport service, disconnecting temporarily.\n");
+ GNUNET_MQ_destroy (ghh->mq);
+ ghh->mq = NULL;
+ schedule_reconnect (ghh);
+}
+
+
+/**
+ * Try again to connect to transport service.
+ *
+ * @param cls the handle to the transport service
+ */
+static void
+reconnect (void *cls)
+{
+ GNUNET_MQ_hd_var_size (hello,
+ GNUNET_MESSAGE_TYPE_HELLO,
+ struct GNUNET_MessageHeader);
+ struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+ struct GNUNET_MQ_MessageHandler handlers[] = {
+ make_hello_handler (ghh),
+ GNUNET_MQ_handler_end ()
+ };
+ struct GNUNET_MQ_Envelope *env;
+ struct StartMessage *s;
+
+ ghh->reconnect_task = NULL;
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Connecting to transport service.\n");
+ GNUNET_assert (NULL == ghh->mq);
+ ghh->mq = GNUNET_CLIENT_connecT (ghh->cfg,
+ "transport",
+ handlers,
+ &mq_error_handler,
+ ghh);
+ if (NULL == ghh->mq)
+ return;
+ env = GNUNET_MQ_msg (s,
+ GNUNET_MESSAGE_TYPE_TRANSPORT_START);
+ s->options = htonl (0);
+ GNUNET_MQ_send (ghh->mq,
+ env);
+}
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param ghh transport service to reconnect
+ */
+static void
+schedule_reconnect (struct GNUNET_TRANSPORT_HelloGetHandle *ghh)
+{
+ ghh->reconnect_task =
+ GNUNET_SCHEDULER_add_delayed (ghh->reconnect_delay,
+ &reconnect,
+ ghh);
+ ghh->reconnect_delay = GNUNET_TIME_STD_BACKOFF (ghh->reconnect_delay);
+}
+
+
+/**
+ * Obtain the HELLO message for this peer. The callback given in this function
+ * is never called synchronously.
+ *
+ * @param cfg configuration
+ * @param nt which network type should the addresses from the HELLO belong to?
+ * @param rec function to call with the HELLO, sender will be our peer
+ * identity; message and sender will be NULL on timeout
+ * (handshake with transport service pending/failed).
+ * cost estimate will be 0.
+ * @param rec_cls closure for @a rec
+ * @return handle to cancel the operation
+ */
+struct GNUNET_TRANSPORT_HelloGetHandle *
+GNUNET_TRANSPORT_hello_get (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ enum GNUNET_ATS_Network_Type nt,
+ GNUNET_TRANSPORT_HelloUpdateCallback rec,
+ void *rec_cls)
+{
+ struct GNUNET_TRANSPORT_HelloGetHandle *ghh;
+
+ ghh = GNUNET_new (struct GNUNET_TRANSPORT_HelloGetHandle);
+ ghh->rec = rec;
+ ghh->rec_cls = rec_cls;
+ ghh->cfg = cfg;
+ ghh->nt = nt;
+ reconnect (ghh);
+ if (NULL == ghh->mq)
+ {
+ GNUNET_free (ghh);
+ return NULL;
+ }
+ return ghh;
+}
+
+
+/**
+ * Stop receiving updates about changes to our HELLO message.
+ *
+ * @param ghh handle to cancel
+ */
+void
+GNUNET_TRANSPORT_hello_get_cancel (struct GNUNET_TRANSPORT_HelloGetHandle *ghh)
+{
+ if (NULL != ghh->reconnect_task)
+ {
+ GNUNET_SCHEDULER_cancel (ghh->reconnect_task);
+ ghh->reconnect_task = NULL;
+ }
+ if (NULL != ghh->mq)
+ {
+ GNUNET_MQ_destroy (ghh->mq);
+ ghh->mq = NULL;
+ }
+ GNUNET_free (ghh);
+}
+
+
+/* end of transport_api_hello_get.c */