1 files changed, 429 insertions, 0 deletions

diff --git a/src/namecache/gnunet-service-namecache.c b/src/namecache/gnunet-service-namecache.c
new file mode 100644
index 000000000..832f02b45
--- /dev/null
+++ b/src/namecache/gnunet-service-namecache.c
@@ -0,0 +1,429 @@
+/*
+     This file is part of GNUnet.
+     (C) 2012, 2013 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 namecache/gnunet-service-namecache.c
+ * @brief namecache for the GNUnet naming system
+ * @author Matthias Wachs
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_dnsparser_lib.h"
+#include "gnunet_namecache_service.h"
+#include "gnunet_namecache_plugin.h"
+#include "gnunet_signatures.h"
+#include "namecache.h"
+
+#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
+
+
+/**
+ * A namecache client
+ */
+struct NamecacheClient;
+
+
+/**
+ * A namecache client
+ */
+struct NamecacheClient
+{
+  /**
+   * Next element in the DLL
+   */
+  struct NamecacheClient *next;
+
+  /**
+   * Previous element in the DLL
+   */
+  struct NamecacheClient *prev;
+
+  /**
+   * The client
+   */
+  struct GNUNET_SERVER_Client *client;
+
+};
+
+
+/**
+ * Configuration handle.
+ */
+static const struct GNUNET_CONFIGURATION_Handle *GSN_cfg;
+
+/**
+ * Database handle
+ */
+static struct GNUNET_NAMECACHE_PluginFunctions *GSN_database;
+
+/**
+ * Name of the database plugin
+ */
+static char *db_lib_name;
+
+/**
+ * Our notification context.
+ */
+static struct GNUNET_SERVER_NotificationContext *snc;
+
+/**
+ * Head of the Client DLL
+ */
+static struct NamecacheClient *client_head;
+
+/**
+ * Tail of the Client DLL
+ */
+static struct NamecacheClient *client_tail;
+
+/**
+ * Notification context shared by all monitors.
+ */
+static struct GNUNET_SERVER_NotificationContext *monitor_nc;
+
+
+
+/**
+ * Task run during shutdown.
+ *
+ * @param cls unused
+ * @param tc unused
+ */
+static void
+cleanup_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct NamecacheClient *nc;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Stopping namecache service\n");
+  if (NULL != snc)
+  {
+    GNUNET_SERVER_notification_context_destroy (snc);
+    snc = NULL;
+  }
+  while (NULL != (nc = client_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (client_head, client_tail, nc);
+    GNUNET_SERVER_client_set_user_context (nc->client, NULL);
+    GNUNET_free (nc);
+  }
+  GNUNET_break (NULL == GNUNET_PLUGIN_unload (db_lib_name, GSN_database));
+  GNUNET_free (db_lib_name);
+  db_lib_name = NULL;
+  if (NULL != monitor_nc)
+  {
+    GNUNET_SERVER_notification_context_destroy (monitor_nc);
+    monitor_nc = NULL;
+  }
+}
+
+
+/**
+ * Called whenever a client is disconnected.
+ * Frees our resources associated with that client.
+ *
+ * @param cls closure
+ * @param client identification of the client
+ */
+static void
+client_disconnect_notification (void *cls,
+                                struct GNUNET_SERVER_Client *client)
+{
+  struct NamecacheClient *nc;
+
+  if (NULL == client)
+    return;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Client %p disconnected\n",
+              client);
+  if (NULL == (nc = GNUNET_SERVER_client_get_user_context (client, struct NamecacheClient)))
+    return;
+  GNUNET_CONTAINER_DLL_remove (client_head, client_tail, nc);
+  GNUNET_free (nc);
+}
+
+
+/**
+ * Add a client to our list of active clients, if it is not yet
+ * in there.
+ *
+ * @param client client to add
+ * @return internal namecache client structure for this client
+ */
+static struct NamecacheClient *
+client_lookup (struct GNUNET_SERVER_Client *client)
+{
+  struct NamecacheClient *nc;
+
+  nc = GNUNET_SERVER_client_get_user_context (client, struct NamecacheClient);
+  if (NULL != nc)
+    return nc;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Client %p connected\n",
+              client);
+  nc = GNUNET_new (struct NamecacheClient);
+  nc->client = client;
+  GNUNET_SERVER_notification_context_add (snc, client);
+  GNUNET_CONTAINER_DLL_insert (client_head, client_tail, nc);
+  GNUNET_SERVER_client_set_user_context (client, nc);
+  return nc;
+}
+
+
+/**
+ * Context for name lookups passed from #handle_lookup_block to
+ * #handle_lookup_block_it as closure
+ */
+struct LookupBlockContext
+{
+  /**
+   * The client to send the response to
+   */
+  struct NamecacheClient *nc;
+
+  /**
+   * Operation id for the name lookup
+   */
+  uint32_t request_id;
+
+};
+
+
+/**
+ * A #GNUNET_NAMECACHE_BlockCallback for name lookups in #handle_lookup_block
+ *
+ * @param cls a `struct LookupNameContext *` with information about the request
+ * @param block the block
+ */
+static void
+handle_lookup_block_it (void *cls,
+                        const struct GNUNET_NAMESTORE_Block *block)
+{
+  struct LookupBlockContext *lnc = cls;
+  struct LookupBlockResponseMessage *r;
+  size_t esize;
+
+  esize = ntohl (block->purpose.size)
+    - sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose)
+    - sizeof (struct GNUNET_TIME_AbsoluteNBO);
+  r = GNUNET_malloc (sizeof (struct LookupBlockResponseMessage) + esize);
+  r->gns_header.header.type = htons (GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE);
+  r->gns_header.header.size = htons (sizeof (struct LookupBlockResponseMessage) + esize);
+  r->gns_header.r_id = htonl (lnc->request_id);
+  r->expire = block->expiration_time;
+  r->signature = block->signature;
+  r->derived_key = block->derived_key;
+  memcpy (&r[1], &block[1], esize);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Sending `%s' message with expiration time %s\n",
+              "NAMECACHE_LOOKUP_BLOCK_RESPONSE",
+              GNUNET_STRINGS_absolute_time_to_string (GNUNET_TIME_absolute_ntoh (r->expire)));
+  GNUNET_SERVER_notification_context_unicast (snc,
+                                              lnc->nc->client,
+                                              &r->gns_header.header,
+                                              GNUNET_NO);
+  GNUNET_free (r);
+}
+
+
+/**
+ * Handles a #GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK message
+ *
+ * @param cls unused
+ * @param client client sending the message
+ * @param message message of type 'struct LookupNameMessage'
+ */
+static void
+handle_lookup_block (void *cls,
+                    struct GNUNET_SERVER_Client *client,
+                    const struct GNUNET_MessageHeader *message)
+{
+  const struct LookupBlockMessage *ln_msg;
+  struct LookupBlockContext lnc;
+  struct NamecacheClient *nc;
+  struct LookupBlockResponseMessage zir_end;
+  int ret;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received `%s' message\n",
+              "NAMECACHE_LOOKUP_BLOCK");
+  nc = client_lookup(client);
+  ln_msg = (const struct LookupBlockMessage *) message;
+  lnc.request_id = ntohl (ln_msg->gns_header.r_id);
+  lnc.nc = nc;
+  if (GNUNET_SYSERR ==
+      (ret = GSN_database->lookup_block (GSN_database->cls,
+                                         &ln_msg->query,
+                                         &handle_lookup_block_it, &lnc)))
+  {
+    /* internal error (in database plugin); might be best to just hang up on
+       plugin rather than to signal that there are 'no' results, which
+       might also be false... */
+    GNUNET_break (0);
+    GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+    return;
+  }
+  if (0 == ret)
+  {
+    /* no records match at all, generate empty response */
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Sending empty `%s' message\n",
+                "NAMECACHE_LOOKUP_BLOCK_RESPONSE");
+    memset (&zir_end, 0, sizeof (zir_end));
+    zir_end.gns_header.header.type = htons (GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE);
+    zir_end.gns_header.header.size = htons (sizeof (struct LookupBlockResponseMessage));
+    zir_end.gns_header.r_id = ln_msg->gns_header.r_id;
+    GNUNET_SERVER_notification_context_unicast (snc,
+                                                client,
+                                                &zir_end.gns_header.header,
+                                                GNUNET_NO);
+
+  }
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+/**
+ * Handles a #GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE message
+ *
+ * @param cls unused
+ * @param client client sending the message
+ * @param message message of type 'struct BlockCacheMessage'
+ */
+static void
+handle_block_cache (void *cls,
+                     struct GNUNET_SERVER_Client *client,
+                     const struct GNUNET_MessageHeader *message)
+{
+  struct NamecacheClient *nc;
+  const struct BlockCacheMessage *rp_msg;
+  struct BlockCacheResponseMessage rpr_msg;
+  struct GNUNET_NAMESTORE_Block *block;
+  size_t esize;
+  int res;
+
+  nc = client_lookup (client);
+  if (ntohs (message->size) < sizeof (struct BlockCacheMessage))
+  {
+    GNUNET_break (0);
+    GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+    return;
+  }
+  rp_msg = (const struct BlockCacheMessage *) message;
+  esize = ntohs (rp_msg->gns_header.header.size) - sizeof (struct BlockCacheMessage);
+  block = GNUNET_malloc (sizeof (struct GNUNET_NAMESTORE_Block) + esize);
+  block->signature = rp_msg->signature;
+  block->derived_key = rp_msg->derived_key;
+  block->purpose.size = htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
+                               sizeof (struct GNUNET_TIME_AbsoluteNBO) +
+                               esize);
+  block->expiration_time = rp_msg->expire;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received `%s' message with expiration time %s\n",
+              "NAMECACHE_BLOCK_CACHE",
+              GNUNET_STRINGS_absolute_time_to_string (GNUNET_TIME_absolute_ntoh (block->expiration_time)));
+  memcpy (&block[1], &rp_msg[1], esize);
+  res = GSN_database->cache_block (GSN_database->cls,
+                                   block);
+  GNUNET_free (block);
+
+  rpr_msg.gns_header.header.type = htons (GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE);
+  rpr_msg.gns_header.header.size = htons (sizeof (struct BlockCacheResponseMessage));
+  rpr_msg.gns_header.r_id = rp_msg->gns_header.r_id;
+  rpr_msg.op_result = htonl (res);
+  GNUNET_SERVER_notification_context_unicast (snc,
+                                              nc->client,
+                                              &rpr_msg.gns_header.header,
+                                              GNUNET_NO);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+/**
+ * Process namecache requests.
+ *
+ * @param cls closure
+ * @param server the initialized server
+ * @param cfg configuration to use
+ */
+static void
+run (void *cls, struct GNUNET_SERVER_Handle *server,
+     const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  static const struct GNUNET_SERVER_MessageHandler handlers[] = {
+    {&handle_lookup_block, NULL,
+     GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK, sizeof (struct LookupBlockMessage)},
+    {&handle_block_cache, NULL,
+    GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE, 0},
+    {NULL, NULL, 0, 0}
+  };
+  char *database;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting namecache service\n");
+  GSN_cfg = cfg;
+  monitor_nc = GNUNET_SERVER_notification_context_create (server, 1);
+
+  /* Loading database plugin */
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (cfg, "namecache", "database",
+                                             &database))
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No database backend configured\n");
+
+  GNUNET_asprintf (&db_lib_name, "libgnunet_plugin_namecache_%s", database);
+  GSN_database = GNUNET_PLUGIN_load (db_lib_name, (void *) GSN_cfg);
+  GNUNET_free (database);
+  if (NULL == GSN_database)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Could not load database backend `%s'\n",
+                db_lib_name);
+    GNUNET_SCHEDULER_add_now (&cleanup_task, NULL);
+    return;
+  }
+
+  /* Configuring server handles */
+  GNUNET_SERVER_add_handlers (server, handlers);
+  snc = GNUNET_SERVER_notification_context_create (server, 16);
+  GNUNET_SERVER_disconnect_notify (server,
+                                   &client_disconnect_notification,
+                                   NULL);
+  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup_task,
+                                NULL);
+}
+
+
+/**
+ * The main function for the template service.
+ *
+ * @param argc number of arguments from the command line
+ * @param argv command line arguments
+ * @return 0 ok, 1 on error
+ */
+int
+main (int argc, char *const *argv)
+{
+  return (GNUNET_OK ==
+          GNUNET_SERVICE_run (argc, argv, "namecache",
+                              GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1;
+}
+
+/* end of gnunet-service-namecache.c */
+