extra semi
[oweals/gnunet.git] / src / hostlist / hostlist-server.c
index 4ffcc27f41086ba230d2034cfbc233c5f937835c..055c90bab439c9f82ee8e16520d9efa72510fc9b 100644 (file)
@@ -20,7 +20,7 @@
 
 /**
  * @file hostlist/hostlist-server.c
- * @author Christian Grothoff
+ * @author Christian Grothoff, Matthias Wachs
  * @brief application to provide an integrated hostlist HTTP server
  */
 
 
 #define DEBUG_HOSTLIST_SERVER GNUNET_NO
 
-/**
- * How often should we recalculate our response to hostlist requests?
- */
-#define RESPONSE_UPDATE_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
-
 /**
  * Handle to the HTTP server as provided by libmicrohttpd for IPv6.
  */
@@ -64,6 +59,16 @@ static struct GNUNET_SCHEDULER_Handle *sched;
  */ 
 static struct GNUNET_STATISTICS_Handle *stats;
 
+/**
+ * Handle to the core service (NULL until we've connected to it).
+ */
+struct GNUNET_CORE_Handle *core;
+
+/**
+ * Handle to the peerinfo notify service (NULL until we've connected to it).
+ */
+struct GNUNET_PEERINFO_NotifyContext *notify;
+
 /**
  * Our primary task for IPv4.
  */
@@ -74,11 +79,6 @@ static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v4;
  */
 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v6;
 
-/**
- * Task that updates our HTTP response.
- */
-static GNUNET_SCHEDULER_TaskIdentifier response_task;
-
 /**
  * Our canonical response.
  */
@@ -89,6 +89,11 @@ static struct MHD_Response *response;
  */
 static struct GNUNET_PEERINFO_IteratorContext *pitr;
 
+/**
+ * Handle for accessing peerinfo service.
+ */
+static struct GNUNET_PEERINFO_Handle *peerinfo;
+
 /**
  * Context for host processor.
  */
@@ -100,77 +105,20 @@ struct HostSet
 };
 
 /**
- * Task that will produce a new response object.
+ * Set if we are allowed to advertise our hostlist to others.
  */
-static void
-update_response (void *cls,
-                const struct GNUNET_SCHEDULER_TaskContext *tc);
+static int advertising;
 
 /**
- * Function that assembles our hostlist adv message.
+ * How many times was the hostlist advertised?
  */
-static int
-create_hostlist_adv_message (struct GNUNET_HOSTLIST_ADV_Message *adv_msg)
-{
-  int length  = 0;
-  int size    = 0;
-  unsigned long long port;
-
-  char *uri;
-  char hostname[HOST_NAME_MAX];
-  char *protocol = "http://";
-  char *port_s = GNUNET_malloc(6 * sizeof(char));
-
-  if (0 != gethostname (hostname, sizeof (hostname) - 1))
-  {
-    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
-        "Could not get system's hostname, unable to create advertisement message");
-    return GNUNET_NO;
-  }
-  if (-1 == GNUNET_CONFIGURATION_get_value_number (cfg,
-                                                   "HOSTLIST",
-                                                   "HTTPPORT",
-                                                   &port))
-    return GNUNET_SYSERR;
-
-  sprintf(port_s, "%llu", port);
-  length = strlen(hostname)+strlen(protocol)+strlen(port_s)+2;
-  size = (length+1) * sizeof (char);
-  uri = GNUNET_malloc(size);
-  uri = strcpy(uri, protocol);
-  uri = strcat(uri, hostname);
-  uri = strcat(uri, ":");
-  uri = strcat(uri, port_s);
-  uri = strcat(uri, "/");
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,"Address to obtain hostlist: %s\n", uri);
-
-
-  adv_msg = GNUNET_malloc ( sizeof(struct GNUNET_HOSTLIST_ADV_Message) + size);
-  if ( NULL == adv_msg)
-    {
-    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
-        "Could not allocate memory for the message");
-    return GNUNET_NO;
-    }
-  GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
-      "size ADV_Message: %u\n",sizeof(struct GNUNET_HOSTLIST_ADV_Message));
-  GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
-      "size uri: %u\n", (length + 1) * sizeof (char));
+static uint64_t hostlist_adv_count;
 
+/**
+ * Buffer for the hostlist address
+ */
+static char * hostlist_uri;
 
-  if ( ( size + sizeof( struct GNUNET_HOSTLIST_ADV_Message )) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
-    {
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
-          "Advertisement message is bigger than GNUNET allows");
-      return GNUNET_NO;
-    }
-
-  adv_msg->header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
-  adv_msg->header.size = htons (sizeof (struct GNUNET_HOSTLIST_ADV_Message) + size);
-  memcpy(&adv_msg[1],uri,size);
-
-  return GNUNET_OK;
-}
 
 /**
  * Function that assembles our response.
@@ -178,8 +126,6 @@ create_hostlist_adv_message (struct GNUNET_HOSTLIST_ADV_Message *adv_msg)
 static void
 finish_response (struct HostSet *results)
 {
-  struct GNUNET_TIME_Relative freq;
-
   if (response != NULL)
     MHD_destroy_response (response);
 #if DEBUG_HOSTLIST_SERVER
@@ -189,24 +135,12 @@ finish_response (struct HostSet *results)
 #endif
   response = MHD_create_response_from_data (results->size,
                                             results->data, MHD_YES, MHD_NO);
-  if ( (daemon_handle_v4 != NULL) ||
-       (daemon_handle_v6 != NULL) )
-    {
-      freq = RESPONSE_UPDATE_FREQUENCY;
-      if (results->size == 0)
-        freq = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 250);
-      /* schedule next update of the response */
-      response_task = GNUNET_SCHEDULER_add_delayed (sched,
-                                                    freq,
-                                                    &update_response,
-                                                    NULL);
-    }
-  else
-    {
-      /* already past shutdown */
-      MHD_destroy_response (response);
-      response = NULL;
-    }
+  if ( (daemon_handle_v4 == NULL) &&
+       (daemon_handle_v6 == NULL) )
+  {
+    MHD_destroy_response (response);
+    response = NULL;
+  }
   GNUNET_STATISTICS_set (stats,
                          gettext_noop("bytes in hostlist"),
                          results->size,
@@ -229,7 +163,8 @@ static int
 check_has_addr (void *cls,
                const char *tname,
                struct GNUNET_TIME_Absolute expiration,
-               const void *addr, size_t addrlen)
+               const void *addr,
+               uint16_t addrlen)
 {
   int *arg = cls;
 
@@ -267,6 +202,8 @@ host_processor (void *cls,
       finish_response (results);
       return;
     }
+  if (hello == NULL)
+    return;
   has_addr = GNUNET_NO;
   GNUNET_HELLO_iterate_addresses (hello,
                                  GNUNET_NO,
@@ -292,7 +229,7 @@ host_processor (void *cls,
              "HELLO",
              GNUNET_i2s (peer));
 #endif
-  if (old + s >= GNUNET_MAX_MALLOC_CHECKED)
+  if ( (old + s >= GNUNET_MAX_MALLOC_CHECKED) || (old + s >= MAX_BYTES_PER_HOSTLISTS) )
     {
       GNUNET_STATISTICS_update (stats,
                                gettext_noop("bytes not included in hostlist (size limit)"),
@@ -300,10 +237,12 @@ host_processor (void *cls,
                                GNUNET_NO);
       return; /* too large, skip! */
     }
+#if DEBUG_HOSTLIST_SERVER
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "Adding peer `%s' to hostlist (%u bytes)\n",
              GNUNET_i2s (peer),
              (unsigned int) s);
+#endif
   GNUNET_array_grow (results->data,
                      results->size,
                      old + s);
@@ -311,25 +250,6 @@ host_processor (void *cls,
 }
 
 
-/**
- * Task that will produce a new response object.
- */
-static void
-update_response (void *cls,
-                const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  struct HostSet *results;
-
-  response_task = GNUNET_SCHEDULER_NO_TASK;
-  results = GNUNET_malloc(sizeof(struct HostSet));
-  pitr = GNUNET_PEERINFO_iterate (cfg, sched, 
-                                 NULL,
-                                 0, 
-                                 GNUNET_TIME_UNIT_MINUTES,
-                                 &host_processor,
-                                 results);
-}
-
 
 /**
  * Hostlist access policy (very permissive, allows everything).
@@ -415,6 +335,51 @@ access_handler_callback (void *cls,
   return MHD_queue_response (connection, MHD_HTTP_OK, response);
 }
 
+
+/**
+ * Handler called by core when core is ready to transmit message
+ * @param cls   closure
+ * @param size  size of buffer to copy message to
+ * @param buf   buffer to copy message to
+ */
+static size_t
+adv_transmit_ready ( void *cls, size_t size, void *buf)
+{
+  size_t transmission_size;
+  size_t uri_size; /* Including \0 termination! */
+  struct GNUNET_MessageHeader header;
+  char *cbuf;
+
+  if (buf == NULL)
+    {
+      GNUNET_log ( GNUNET_ERROR_TYPE_DEBUG, 
+                  "Transmission failed, buffer invalid!\n" );
+      return 0;
+    }
+  uri_size = strlen ( hostlist_uri ) + 1;
+  transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
+  header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
+  header.size = htons (transmission_size);
+  GNUNET_assert (size >= transmission_size);
+  memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
+  cbuf = buf;  
+  memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)],
+         hostlist_uri, uri_size);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
+             "Sent advertisement message: Copied %u bytes into buffer!\n", 
+             (unsigned int) transmission_size);
+  hostlist_adv_count++;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              " # Sent advertisement message: %u\n",
+              hostlist_adv_count);
+  GNUNET_STATISTICS_set (stats,
+                         gettext_noop("# hostlist advertisements send"),
+                         hostlist_adv_count,
+                         GNUNET_NO);
+  return transmission_size;
+}
+
+
 /**
  * Method called whenever a given peer connects.
  *
@@ -430,12 +395,37 @@ connect_handler (void *cls,
                  struct GNUNET_TIME_Relative latency,
                  uint32_t distance)
 {
+  size_t size;
+
+  if ( !advertising )
+    return;
+  if (hostlist_uri == NULL)
+    return;
+  size = strlen (hostlist_uri) + 1;
+  if (size + sizeof (struct GNUNET_MessageHeader) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  size += sizeof (struct GNUNET_MessageHeader);
+  if (NULL == core)
+    {
+      GNUNET_break (0);
+      return;
+    }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "A new peer connected to the server, preparing to send hostlist advertisement\n");
-  /* create a new advertisement message */
-  struct GNUNET_HOSTLIST_ADV_Message *adv_msg;
-  create_hostlist_adv_message(adv_msg);
-
+              "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
+             size,GNUNET_i2s(peer));
+  if (NULL == GNUNET_CORE_notify_transmit_ready (core,
+                                                0,
+                                                GNUNET_ADV_TIMEOUT,
+                                                peer,
+                                                size,
+                                                &adv_transmit_ready, NULL))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 _("Advertisement message could not be queued by core\n"));
+    }
 }
 
 
@@ -450,9 +440,38 @@ disconnect_handler (void *cls,
                     const struct
                     GNUNET_PeerIdentity * peer)
 {
-
+  /* nothing to do */
 }
 
+/**
+ * PEERINFO calls this function to let us know about a possible peer
+ * that we might want to connect to.
+ *
+ * @param cls closure (not used)
+ * @param peer potential peer to connect to
+ * @param hello HELLO for this peer (or NULL)
+ * @param trust how much we trust the peer (not used)
+ */
+static void
+process_notify (void *cls,
+                const struct GNUNET_PeerIdentity *peer,
+                const struct GNUNET_HELLO_Message *hello,
+                uint32_t trust)
+{
+  struct HostSet *results;
+#if DEBUG_HOSTLIST_SERVER
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+            "Peerinfo is notifying us to rebuild our hostlist\n");
+#endif
+  results = GNUNET_malloc(sizeof(struct HostSet));
+  GNUNET_assert (peerinfo != NULL);
+  pitr = GNUNET_PEERINFO_iterate (peerinfo,
+                                  NULL,
+                                  0,
+                                  GNUNET_TIME_UNIT_MINUTES,
+                                  &host_processor,
+                                  results);
+}
 
 /**
  * Function that queries MHD's select sets and
@@ -461,6 +480,7 @@ disconnect_handler (void *cls,
 static GNUNET_SCHEDULER_TaskIdentifier
 prepare_daemon (struct MHD_Daemon *daemon_handle);
 
+
 /**
  * Call MHD to process pending requests and then go back
  * and schedule the next run.
@@ -551,22 +571,66 @@ int
 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
                              struct GNUNET_SCHEDULER_Handle *s,
                              struct GNUNET_STATISTICS_Handle *st,
+                             struct GNUNET_CORE_Handle *co,
                              GNUNET_CORE_ConnectEventHandler *server_ch,
-                              GNUNET_CORE_DisconnectEventHandler *server_dh)
+                              GNUNET_CORE_DisconnectEventHandler *server_dh,
+                              int advertise)
 {
   unsigned long long port;
+  char *hostname;
+  size_t size;
 
+  advertising = advertise;
+  if  ( !advertising )
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Advertising not enabled on this hostlist server\n");
+  else
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Advertising enabled on this hostlist server\n");
   sched = s;
   cfg = c;
   stats = st;
+  peerinfo = GNUNET_PEERINFO_connect (sched, cfg);
+  if (peerinfo == NULL)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Could not access PEERINFO service.  Exiting.\n"));     
+      return GNUNET_SYSERR;
+    }
   if (-1 == GNUNET_CONFIGURATION_get_value_number (cfg,
                                                   "HOSTLIST",
                                                   "HTTPPORT", 
                                                   &port))
     return GNUNET_SYSERR;
+
+  if ( GNUNET_SYSERR  == GNUNET_CONFIGURATION_get_value_string (cfg,
+                                                   "HOSTLIST",
+                                                   "EXTERNAL_DNS_NAME",
+                                                   &hostname))
+    hostname = GNUNET_RESOLVER_local_fqdn_get ();
+
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-             _("Hostlist service starts on port %llu\n"),
-             port);
+              _("Hostlist service starts on %s:%llu\n"),
+              hostname, port);
+  if (NULL != hostname)
+    {
+      size = strlen (hostname);
+      if (size + 15 > MAX_URL_LEN)
+       {
+         GNUNET_break (0);
+       }
+      else
+       {
+         GNUNET_asprintf (&hostlist_uri,
+                          "http://%s:%u/",
+                          hostname,
+                          (unsigned int) port);
+         GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                     _("Address to obtain hostlist: `%s'\n"), 
+                     hostlist_uri);
+       }
+      GNUNET_free ( hostname );
+    }
   daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6 
 #if DEBUG_HOSTLIST_SERVER
                                       | MHD_USE_DEBUG
@@ -607,6 +671,8 @@ GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
       return GNUNET_SYSERR;    
     }
 
+  core = co;
+
   *server_ch = &connect_handler;
   *server_dh = &disconnect_handler;
 
@@ -614,9 +680,9 @@ GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
     hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
   if (daemon_handle_v6 != NULL)
     hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
-  response_task = GNUNET_SCHEDULER_add_now (sched,
-                                           &update_response,
-                                           NULL);
+
+  notify = GNUNET_PEERINFO_notify ( cfg, sched, process_notify, NULL);
+
   return GNUNET_OK;
 }
 
@@ -630,6 +696,11 @@ GNUNET_HOSTLIST_server_stop ()
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Hostlist server shutdown\n");
 #endif
+  if (NULL != notify)
+    {
+      GNUNET_PEERINFO_notify_cancel (notify);
+      notify = NULL;
+    }
   if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
     {
       GNUNET_SCHEDULER_cancel (sched, hostlist_task_v6);
@@ -645,11 +716,6 @@ GNUNET_HOSTLIST_server_stop ()
       GNUNET_PEERINFO_iterate_cancel (pitr);
       pitr = NULL;
     }
-  if (GNUNET_SCHEDULER_NO_TASK != response_task)
-    {
-      GNUNET_SCHEDULER_cancel (sched, response_task);
-      response_task = GNUNET_SCHEDULER_NO_TASK;
-    }
   if (NULL != daemon_handle_v4)
     {
       MHD_stop_daemon (daemon_handle_v4);
@@ -665,6 +731,15 @@ GNUNET_HOSTLIST_server_stop ()
       MHD_destroy_response (response);
       response = NULL;
     }
+  if (peerinfo != NULL)
+    {
+      GNUNET_PEERINFO_disconnect (peerinfo);
+      peerinfo = NULL;
+    }
+  cfg = NULL;
+  sched = NULL;
+  stats = NULL;
+  core = NULL;
 }
 
 /* end of hostlist-server.c */