blacklisting API implementation

1 files changed, 386 insertions, 0 deletions

diff --git a/src/transport/transport_api_blacklist.c b/src/transport/transport_api_blacklist.c
new file mode 100644
index 000000000..d33c4123c
--- /dev/null
+++ b/src/transport/transport_api_blacklist.c
@@ -0,0 +1,386 @@
+/*
+     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 2, 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_BlacklistRequest
+{
+
+  /**
+   * Connection to transport service.
+   */
+  struct GNUNET_CLIENT_Connection * client;
+
+  /**
+   * Function to call when done.
+   */
+  GNUNET_SCHEDULER_Task cont;
+
+  /**
+   * Clsoure for 'cont'.
+   */
+  void *cont_cls;
+
+  /**
+   * Scheduler to use.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+  /**
+   * Pending handle for the blacklisting request.
+   */ 
+  struct GNUNET_CLIENT_TransmitHandle *th;
+  
+  /**
+   * How long should 'peer' be blacklisted?
+   */
+  struct GNUNET_TIME_Absolute duration;
+  
+  /**
+   * Which peer is being blacklisted?
+   */
+  struct GNUNET_PeerIdentity peer;
+  
+};
+
+
+/**
+ * Function called to notify a client about the socket
+ * begin ready to queue more data.  "buf" will be
+ * NULL and "size" zero if the socket was closed for
+ * writing in the meantime.
+ *
+ * @param cls closure
+ * @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_request (void *cls,
+                            size_t size, void *buf)
+{
+  struct GNUNET_TRANSPORT_BlacklistRequest *br = cls;
+  struct BlacklistMessage req;
+
+  if (buf == NULL)
+    {
+      GNUNET_SCHEDULER_add_continuation (br->sched,
+                                         br->cont,
+                                         br->cont_cls,
+                                         GNUNET_SCHEDULER_REASON_TIMEOUT);
+      GNUNET_free (br);
+      return 0;
+    }
+  req.header.size = htons (sizeof (req));
+  req.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST);
+  req.reserved = htonl (0);
+  req.peer = br->peer;
+  req.until = GNUNET_TIME_absolute_hton (br->duration);
+  memcpy (buf, &req, sizeof (req));
+  GNUNET_SCHEDULER_add_continuation (br->sched,
+                                     br->cont,
+                                     br->cont_cls,
+                                     GNUNET_SCHEDULER_REASON_PREREQ_DONE);
+  GNUNET_free (br);
+  return sizeof (req);
+}
+
+
+/**
+ * Blacklist a peer for a given period of time.  All connections
+ * (inbound and outbound) to a peer that is blacklisted will be
+ * dropped (as soon as we learn who the connection is for).  A second
+ * call to this function for the same peer overrides previous
+ * blacklisting requests.
+ *
+ * @param sched scheduler to use
+ * @param cfg configuration to use
+ * @param peer identity of peer to blacklist
+ * @param duration how long to blacklist, use GNUNET_TIME_UNIT_ZERO to
+ *        re-enable connections
+ * @param timeout when should this operation (trying to establish the
+ *        blacklisting time out)
+ * @param cont continuation to call once the request has been processed
+ * @param cont_cls closure for cont
+ * @return NULL on error, otherwise handle for cancellation
+ */
+struct GNUNET_TRANSPORT_BlacklistRequest *
+GNUNET_TRANSPORT_blacklist (struct GNUNET_SCHEDULER_Handle *sched,
+                            const struct GNUNET_CONFIGURATION_Handle *cfg,
+                            const struct GNUNET_PeerIdentity *peer,
+                            struct GNUNET_TIME_Relative duration,
+                            struct GNUNET_TIME_Relative timeout,
+                            GNUNET_SCHEDULER_Task cont,
+                            void *cont_cls)
+{
+  struct GNUNET_CLIENT_Connection * client;
+  struct GNUNET_TRANSPORT_BlacklistRequest *ret;
+
+  client = GNUNET_CLIENT_connect (sched, "transport", cfg);
+  if (NULL == client)
+    return NULL;
+  ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_BlacklistRequest));
+  ret->client = client;
+  ret->peer = *peer;
+  ret->duration = GNUNET_TIME_relative_to_absolute (duration);
+  ret->sched = sched;
+  ret->cont = cont;
+  ret->cont_cls = cont_cls;
+  ret->th = GNUNET_CLIENT_notify_transmit_ready (client,
+                                                 sizeof (struct BlacklistMessage),
+                                                 timeout,
+                                                 GNUNET_YES,
+                                                 &transmit_blacklist_request,
+                                                 ret);
+  GNUNET_assert (NULL != ret->th);
+  return ret;
+}
+
+
+/**
+ * Abort transmitting the blacklist request.  Note that this function
+ * is NOT for removing a peer from the blacklist (for that, call 
+ * GNUNET_TRANSPORT_blacklist with a duration of zero).  This function
+ * is only for aborting the transmission of a blacklist request
+ * (i.e. because of shutdown).
+ *
+ * @param br handle of the request that is to be cancelled
+ */
+void
+GNUNET_TRANSPORT_blacklist_cancel (struct GNUNET_TRANSPORT_BlacklistRequest * br)
+{
+  GNUNET_CLIENT_notify_transmit_ready_cancel (br->th);
+  GNUNET_free (br);
+}
+
+
+/**
+ * Handle for blacklist notifications.
+ */
+struct GNUNET_TRANSPORT_BlacklistNotification
+{
+
+  /**
+   * Function to call whenever there is a change.
+   */
+  GNUNET_TRANSPORT_BlacklistCallback notify;
+
+  /**
+   * Closure for notify.
+   */
+  void *notify_cls;
+
+  /**
+   * Scheduler to use.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+  
+  /**
+   * Connection to transport service.
+   */
+  struct GNUNET_CLIENT_Connection * client;
+
+  /**
+   * Pending handle for the notification request.
+   */ 
+  struct GNUNET_CLIENT_TransmitHandle *th;
+};
+
+
+/**
+ * Send a request to receive blacklisting notifications
+ *
+ * @param bn context to initialize
+ */
+static void
+request_notifications (struct GNUNET_TRANSPORT_BlacklistNotification *bn);
+
+
+/**
+ * Destroy the existing connection to the transport service and
+ * setup a new one (the existing one had serious problems).
+ * 
+ * @param bn context to re-initialize
+ */
+static void
+retry_get_notifications (struct GNUNET_TRANSPORT_BlacklistNotification *bn)
+{
+  GNUNET_CLIENT_disconnect (bn->client);
+  bn->client = GNUNET_CLIENT_connect (bn->sched, "transport", bn->cfg);
+  request_notifications (bn);
+}
+
+
+/**
+ * Function called whenever we get a blacklisting notification.
+ * Pass it on to the callback and wait for more.
+ *
+ * @param cls our 'struct GNUNET_TRANSPORT_BlacklistNotification *'
+ * @param msg the blacklisting notification, NULL on error
+ */
+static void
+recv_blacklist_info (void *cls,
+                     const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_TRANSPORT_BlacklistNotification *bn = cls;
+  const struct BlacklistMessage *req;
+
+  if ( (msg == NULL) ||
+       (sizeof(struct BlacklistMessage) != ntohs(msg->size)) ||
+       (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST != ntohs(msg->type)) )
+    {
+      retry_get_notifications (bn);
+      return;
+    }
+  req = (const struct BlacklistMessage*) msg;
+  bn->notify (bn->notify_cls,
+              &req->peer,
+              GNUNET_TIME_absolute_ntoh (req->until));
+  GNUNET_CLIENT_receive (bn->client,
+                         &recv_blacklist_info,
+                         bn,
+                         GNUNET_TIME_UNIT_FOREVER_REL);  
+}
+
+
+/**
+ * Function called to notify a client about the socket
+ * begin ready to queue more data.  "buf" will be
+ * NULL and "size" zero if the socket was closed for
+ * writing in the meantime.
+ *
+ * @param cls closure
+ * @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_notify_request (void *cls,
+                         size_t size, void *buf)
+{
+  struct GNUNET_TRANSPORT_BlacklistNotification *bn = cls;
+  struct GNUNET_MessageHeader hdr;
+
+  bn->th = NULL;
+  if (buf == NULL)
+    {
+      retry_get_notifications (bn);
+      return 0;
+    }
+  GNUNET_assert (size >= sizeof(hdr));
+  hdr.size = htons (sizeof (hdr));
+  hdr.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BLACKLIST_NOTIFY);
+  memcpy (buf, &hdr, sizeof(hdr));
+  return sizeof(hdr);  
+}
+
+
+/**
+ * Send a request to receive blacklisting notifications
+ *
+ * @param bn context to initialize
+ */
+static void
+request_notifications (struct GNUNET_TRANSPORT_BlacklistNotification *bn)
+{
+  GNUNET_assert (bn->client != NULL);
+  bn->th = GNUNET_CLIENT_notify_transmit_ready (bn->client,
+                                                sizeof (struct GNUNET_MessageHeader),
+                                                GNUNET_TIME_UNIT_FOREVER_REL,
+                                                GNUNET_YES,
+                                                &transmit_notify_request,
+                                                bn);
+  GNUNET_assert (bn->th != NULL);
+  GNUNET_CLIENT_receive (bn->client,
+                         &recv_blacklist_info,
+                         bn,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+}
+
+
+/**
+ * Call a function whenever a peer's blacklisting status changes.
+ *
+ * @param sched scheduler to use
+ * @param cfg configuration to use
+ * @param bc function to call on status changes
+ * @param bc_cls closure for bc
+ * @return NULL on error, otherwise handle for cancellation
+ */
+struct GNUNET_TRANSPORT_BlacklistNotification *
+GNUNET_TRANSPORT_blacklist_notify (struct GNUNET_SCHEDULER_Handle *sched,
+                                   const struct GNUNET_CONFIGURATION_Handle *cfg,
+                                   GNUNET_TRANSPORT_BlacklistCallback bc,
+                                   void *bc_cls)
+{
+  struct GNUNET_TRANSPORT_BlacklistNotification *ret;
+  struct GNUNET_CLIENT_Connection * client;
+
+  client = GNUNET_CLIENT_connect (sched, "transport", cfg);
+  if (NULL == client)
+    return NULL;
+  ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_BlacklistNotification));
+  ret->client = client;
+  ret->sched = sched;
+  ret->cfg = cfg;
+  ret->notify = bc;
+  ret->notify_cls = bc_cls;
+  request_notifications (ret);
+  return ret;
+}
+
+
+/**
+ * Stop calling the notification callback associated with
+ * the given blacklist notification.
+ *
+ * @param bn handle of the request that is to be cancelled
+ */
+void
+GNUNET_TRANSPORT_blacklist_notify_cancel (struct GNUNET_TRANSPORT_BlacklistNotification * bn)
+{
+  if (bn->th != NULL)
+    GNUNET_CLIENT_notify_transmit_ready_cancel (bn->th);
+  GNUNET_CLIENT_disconnect (bn->client);
+  GNUNET_free (bn);
+}
+
+/* end of transport_api_blacklist.c */