Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 296 insertions, 0 deletions

diff --git a/src/transport/transport_api_blacklist.c b/src/transport/transport_api_blacklist.c
new file mode 100644
index 0000000..be52623
--- /dev/null
+++ b/src/transport/transport_api_blacklist.c
@@ -0,0 +1,296 @@
+/*
+     This file is part of GNUnet.
+     (C) 2010 Christian Grothoff (and other contributing authors)
+
+     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 transport/transport_api_blacklist.c
+ * @brief library to access the blacklisting functions of the transport service
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_client_lib.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_time_lib.h"
+#include "gnunet_transport_service.h"
+#include "transport.h"
+
+/**
+ * Handle for blacklisting requests.
+ */
+struct GNUNET_TRANSPORT_Blacklist
+{
+
+  /**
+   * Connection to transport service.
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Pending handle for the current request.
+   */
+  struct GNUNET_CLIENT_TransmitHandle *th;
+
+  /**
+   * Function to call for determining if a peer is allowed
+   * to communicate with us.
+   */
+  GNUNET_TRANSPORT_BlacklistCallback cb;
+
+  /**
+   * Closure for 'cb'.
+   */
+  void *cb_cls;
+
+  /**
+   * Peer currently under consideration.
+   */
+  struct GNUNET_PeerIdentity peer;
+
+};
+
+
+/**
+ * Establish blacklist connection to transport service.
+ *
+ * @param br overall handle
+ */
+static void
+reconnect (struct GNUNET_TRANSPORT_Blacklist *br);
+
+
+/**
+ * Send our reply to a blacklisting request.
+ *
+ * @param br our overall context
+ */
+static void
+reply (struct GNUNET_TRANSPORT_Blacklist *br);
+
+
+/**
+ * Handle blacklist queries.
+ *
+ * @param cls our overall handle
+ * @param msg query
+ */
+static void
+query_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_TRANSPORT_Blacklist *br = cls;
+  const struct BlacklistMessage *bm;
+
+  GNUNET_assert (br != NULL);
+  if ((NULL == msg) ||
+      (ntohs (msg->size) != sizeof (struct BlacklistMessage)) ||
+      (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_QUERY))
+  {
+    reconnect (br);
+    return;
+  }
+  bm = (const struct BlacklistMessage *) msg;
+  GNUNET_break (0 == ntohl (bm->is_allowed));
+  br->peer = bm->peer;
+  reply (br);
+}
+
+
+/**
+ * Receive blacklist queries from transport service.
+ *
+ * @param br overall handle
+ */
+static void
+receive (struct GNUNET_TRANSPORT_Blacklist *br)
+{
+  GNUNET_CLIENT_receive (br->client, &query_handler, br,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+}
+
+
+/**
+ * Transmit the blacklist initialization request to the service.
+ *
+ * @param cls closure (struct GNUNET_TRANSPORT_Blacklist*)
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_blacklist_init (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_TRANSPORT_Blacklist *br = cls;
+  struct GNUNET_MessageHeader req;
+
+  br->th = NULL;
+  if (buf == NULL)
+  {
+    reconnect (br);
+    return 0;
+  }
+  req.size = htons (sizeof (struct GNUNET_MessageHeader));
+  req.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_INIT);
+  memcpy (buf, &req, sizeof (req));
+  receive (br);
+  return sizeof (req);
+}
+
+
+/**
+ * Establish blacklist connection to transport service.
+ *
+ * @param br overall handle
+ */
+static void
+reconnect (struct GNUNET_TRANSPORT_Blacklist *br)
+{
+  if (br->client != NULL)
+    GNUNET_CLIENT_disconnect (br->client, GNUNET_NO);
+  br->client = GNUNET_CLIENT_connect ("transport", br->cfg);
+  GNUNET_assert (br->client != NULL);
+  br->th =
+      GNUNET_CLIENT_notify_transmit_ready (br->client,
+                                           sizeof (struct GNUNET_MessageHeader),
+                                           GNUNET_TIME_UNIT_FOREVER_REL,
+                                           GNUNET_YES, &transmit_blacklist_init,
+                                           br);
+}
+
+
+/**
+ * Transmit the blacklist response to the service.
+ *
+ * @param cls closure (struct GNUNET_TRANSPORT_Blacklist*)
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_blacklist_reply (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_TRANSPORT_Blacklist *br = cls;
+  struct BlacklistMessage req;
+
+  br->th = NULL;
+  if (buf == NULL)
+  {
+    reconnect (br);
+    return 0;
+  }
+  req.header.size = htons (sizeof (req));
+  req.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_REPLY);
+  req.is_allowed = htonl (br->cb (br->cb_cls, &br->peer));
+  req.peer = br->peer;
+  memcpy (buf, &req, sizeof (req));
+  br->th = NULL;
+  receive (br);
+  return sizeof (req);
+}
+
+
+/**
+ * Send our reply to a blacklisting request.
+ *
+ * @param br our overall context
+ */
+static void
+reply (struct GNUNET_TRANSPORT_Blacklist *br)
+{
+  GNUNET_assert (br->th == NULL);
+  br->th =
+      GNUNET_CLIENT_notify_transmit_ready (br->client,
+                                           sizeof (struct BlacklistMessage),
+                                           GNUNET_TIME_UNIT_FOREVER_REL,
+                                           GNUNET_NO, &transmit_blacklist_reply,
+                                           br);
+  if (br->th == NULL)
+  {
+    reconnect (br);
+    return;
+  }
+}
+
+
+/**
+ * Install a blacklist callback.  The service will be queried for all
+ * existing connections as well as any fresh connections to check if
+ * they are permitted.  If the blacklisting callback is unregistered,
+ * all hosts that were denied in the past will automatically be
+ * whitelisted again.  Cancelling the blacklist handle is also the
+ * only way to re-enable connections from peers that were previously
+ * blacklisted.
+ *
+ * @param cfg configuration to use
+ * @param cb callback to invoke to check if connections are allowed
+ * @param cb_cls closure for cb
+ * @return NULL on error, otherwise handle for cancellation
+ */
+struct GNUNET_TRANSPORT_Blacklist *
+GNUNET_TRANSPORT_blacklist (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                            GNUNET_TRANSPORT_BlacklistCallback cb, void *cb_cls)
+{
+  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_TRANSPORT_Blacklist *ret;
+
+  client = GNUNET_CLIENT_connect ("transport", cfg);
+  if (NULL == client)
+    return NULL;
+  ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Blacklist));
+  ret->client = client;
+  ret->cfg = cfg;
+  ret->cb = cb;
+  ret->cb_cls = cb_cls;
+  GNUNET_assert (ret->th == NULL);
+  ret->th =
+      GNUNET_CLIENT_notify_transmit_ready (client,
+                                           sizeof (struct GNUNET_MessageHeader),
+                                           GNUNET_TIME_UNIT_FOREVER_REL,
+                                           GNUNET_YES, &transmit_blacklist_init,
+                                           ret);
+  return ret;
+}
+
+
+/**
+ * Abort the blacklist.  Note that this function is the only way for
+ * removing a peer from the blacklist.
+ *
+ * @param br handle of the request that is to be cancelled
+ */
+void
+GNUNET_TRANSPORT_blacklist_cancel (struct GNUNET_TRANSPORT_Blacklist *br)
+{
+  if (br->th != NULL)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (br->th);
+    br->th = NULL;
+  }
+  GNUNET_CLIENT_disconnect (br->client, GNUNET_NO);
+  GNUNET_free (br);
+}
+
+
+/* end of transport_api_blacklist.c */